dev.c 209.1 KB
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/*
 * 	NET3	Protocol independent device support routines.
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 *	Derived from the non IP parts of dev.c 1.0.19
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 * 		Authors:	Ross Biro
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 *				Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *				Mark Evans, <evansmp@uhura.aston.ac.uk>
 *
 *	Additional Authors:
 *		Florian la Roche <rzsfl@rz.uni-sb.de>
 *		Alan Cox <gw4pts@gw4pts.ampr.org>
 *		David Hinds <dahinds@users.sourceforge.net>
 *		Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
 *		Adam Sulmicki <adam@cfar.umd.edu>
 *              Pekka Riikonen <priikone@poesidon.pspt.fi>
 *
 *	Changes:
 *              D.J. Barrow     :       Fixed bug where dev->refcnt gets set
 *              			to 2 if register_netdev gets called
 *              			before net_dev_init & also removed a
 *              			few lines of code in the process.
 *		Alan Cox	:	device private ioctl copies fields back.
 *		Alan Cox	:	Transmit queue code does relevant
 *					stunts to keep the queue safe.
 *		Alan Cox	:	Fixed double lock.
 *		Alan Cox	:	Fixed promisc NULL pointer trap
 *		????????	:	Support the full private ioctl range
 *		Alan Cox	:	Moved ioctl permission check into
 *					drivers
 *		Tim Kordas	:	SIOCADDMULTI/SIOCDELMULTI
 *		Alan Cox	:	100 backlog just doesn't cut it when
 *					you start doing multicast video 8)
 *		Alan Cox	:	Rewrote net_bh and list manager.
 *		Alan Cox	: 	Fix ETH_P_ALL echoback lengths.
 *		Alan Cox	:	Took out transmit every packet pass
 *					Saved a few bytes in the ioctl handler
 *		Alan Cox	:	Network driver sets packet type before
 *					calling netif_rx. Saves a function
 *					call a packet.
 *		Alan Cox	:	Hashed net_bh()
 *		Richard Kooijman:	Timestamp fixes.
 *		Alan Cox	:	Wrong field in SIOCGIFDSTADDR
 *		Alan Cox	:	Device lock protection.
 *		Alan Cox	: 	Fixed nasty side effect of device close
 *					changes.
 *		Rudi Cilibrasi	:	Pass the right thing to
 *					set_mac_address()
 *		Dave Miller	:	32bit quantity for the device lock to
 *					make it work out on a Sparc.
 *		Bjorn Ekwall	:	Added KERNELD hack.
 *		Alan Cox	:	Cleaned up the backlog initialise.
 *		Craig Metz	:	SIOCGIFCONF fix if space for under
 *					1 device.
 *	    Thomas Bogendoerfer :	Return ENODEV for dev_open, if there
 *					is no device open function.
 *		Andi Kleen	:	Fix error reporting for SIOCGIFCONF
 *	    Michael Chastain	:	Fix signed/unsigned for SIOCGIFCONF
 *		Cyrus Durgin	:	Cleaned for KMOD
 *		Adam Sulmicki   :	Bug Fix : Network Device Unload
 *					A network device unload needs to purge
 *					the backlog queue.
 *	Paul Rusty Russell	:	SIOCSIFNAME
 *              Pekka Riikonen  :	Netdev boot-time settings code
 *              Andrew Morton   :       Make unregister_netdevice wait
 *              			indefinitely on dev->refcnt
 * 		J Hadi Salim	:	- Backlog queue sampling
 *				        - netif_rx() feedback
 */

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#include <linux/uaccess.h>
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#include <linux/bitops.h>
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#include <linux/capability.h>
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#include <linux/cpu.h>
#include <linux/types.h>
#include <linux/kernel.h>
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#include <linux/hash.h>
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#include <linux/slab.h>
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#include <linux/sched.h>
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#include <linux/mutex.h>
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#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/if_ether.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
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#include <linux/ethtool.h>
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#include <linux/notifier.h>
#include <linux/skbuff.h>
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#include <linux/bpf.h>
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#include <net/net_namespace.h>
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#include <net/sock.h>
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#include <net/busy_poll.h>
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#include <linux/rtnetlink.h>
#include <linux/stat.h>
#include <net/dst.h>
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#include <net/dst_metadata.h>
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#include <net/pkt_sched.h>
#include <net/checksum.h>
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#include <net/xfrm.h>
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#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netpoll.h>
#include <linux/rcupdate.h>
#include <linux/delay.h>
#include <net/iw_handler.h>
#include <asm/current.h>
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#include <linux/audit.h>
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#include <linux/dmaengine.h>
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#include <linux/err.h>
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#include <linux/ctype.h>
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#include <linux/if_arp.h>
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#include <linux/if_vlan.h>
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#include <linux/ip.h>
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#include <net/ip.h>
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#include <net/mpls.h>
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#include <linux/ipv6.h>
#include <linux/in.h>
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#include <linux/jhash.h>
#include <linux/random.h>
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#include <trace/events/napi.h>
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#include <trace/events/net.h>
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#include <trace/events/skb.h>
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#include <linux/pci.h>
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#include <linux/inetdevice.h>
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#include <linux/cpu_rmap.h>
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#include <linux/static_key.h>
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#include <linux/hashtable.h>
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#include <linux/vmalloc.h>
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#include <linux/if_macvlan.h>
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#include <linux/errqueue.h>
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#include <linux/hrtimer.h>
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#include <linux/netfilter_ingress.h>
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#include <linux/crash_dump.h>
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#include "net-sysfs.h"

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/* Instead of increasing this, you should create a hash table. */
#define MAX_GRO_SKBS 8

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/* This should be increased if a protocol with a bigger head is added. */
#define GRO_MAX_HEAD (MAX_HEADER + 128)

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static DEFINE_SPINLOCK(ptype_lock);
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static DEFINE_SPINLOCK(offload_lock);
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struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
struct list_head ptype_all __read_mostly;	/* Taps */
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static struct list_head offload_base __read_mostly;
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static int netif_rx_internal(struct sk_buff *skb);
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static int call_netdevice_notifiers_info(unsigned long val,
					 struct net_device *dev,
					 struct netdev_notifier_info *info);
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/*
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 * The @dev_base_head list is protected by @dev_base_lock and the rtnl
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 * semaphore.
 *
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 * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
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 *
 * Writers must hold the rtnl semaphore while they loop through the
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 * dev_base_head list, and hold dev_base_lock for writing when they do the
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 * actual updates.  This allows pure readers to access the list even
 * while a writer is preparing to update it.
 *
 * To put it another way, dev_base_lock is held for writing only to
 * protect against pure readers; the rtnl semaphore provides the
 * protection against other writers.
 *
 * See, for example usages, register_netdevice() and
 * unregister_netdevice(), which must be called with the rtnl
 * semaphore held.
 */
DEFINE_RWLOCK(dev_base_lock);
EXPORT_SYMBOL(dev_base_lock);

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/* protects napi_hash addition/deletion and napi_gen_id */
static DEFINE_SPINLOCK(napi_hash_lock);

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static unsigned int napi_gen_id = NR_CPUS;
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static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);
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static seqcount_t devnet_rename_seq;
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static inline void dev_base_seq_inc(struct net *net)
{
	while (++net->dev_base_seq == 0);
}

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static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
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{
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	unsigned int hash = full_name_hash(net, name, strnlen(name, IFNAMSIZ));
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	return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
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}

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static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
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{
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	return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
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}

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static inline void rps_lock(struct softnet_data *sd)
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{
#ifdef CONFIG_RPS
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	spin_lock(&sd->input_pkt_queue.lock);
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#endif
}

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static inline void rps_unlock(struct softnet_data *sd)
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{
#ifdef CONFIG_RPS
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	spin_unlock(&sd->input_pkt_queue.lock);
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#endif
}

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/* Device list insertion */
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static void list_netdevice(struct net_device *dev)
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{
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	struct net *net = dev_net(dev);
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	ASSERT_RTNL();

	write_lock_bh(&dev_base_lock);
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	list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
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	hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
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	hlist_add_head_rcu(&dev->index_hlist,
			   dev_index_hash(net, dev->ifindex));
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	write_unlock_bh(&dev_base_lock);
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	dev_base_seq_inc(net);
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}

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/* Device list removal
 * caller must respect a RCU grace period before freeing/reusing dev
 */
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static void unlist_netdevice(struct net_device *dev)
{
	ASSERT_RTNL();

	/* Unlink dev from the device chain */
	write_lock_bh(&dev_base_lock);
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	list_del_rcu(&dev->dev_list);
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	hlist_del_rcu(&dev->name_hlist);
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	hlist_del_rcu(&dev->index_hlist);
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	write_unlock_bh(&dev_base_lock);
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	dev_base_seq_inc(dev_net(dev));
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}

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/*
 *	Our notifier list
 */

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static RAW_NOTIFIER_HEAD(netdev_chain);
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/*
 *	Device drivers call our routines to queue packets here. We empty the
 *	queue in the local softnet handler.
 */
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DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
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EXPORT_PER_CPU_SYMBOL(softnet_data);
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#ifdef CONFIG_LOCKDEP
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/*
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 * register_netdevice() inits txq->_xmit_lock and sets lockdep class
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 * according to dev->type
 */
static const unsigned short netdev_lock_type[] =
	{ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
	 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
	 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
	 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
	 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
	 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
	 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
	 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
	 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
	 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
	 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
	 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
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	 ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
	 ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
	 ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
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static const char *const netdev_lock_name[] =
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	{"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
	 "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
	 "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
	 "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
	 "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
	 "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
	 "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
	 "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
	 "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
	 "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
	 "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
	 "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
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	 "_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
	 "_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
	 "_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
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static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
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static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
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static inline unsigned short netdev_lock_pos(unsigned short dev_type)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
		if (netdev_lock_type[i] == dev_type)
			return i;
	/* the last key is used by default */
	return ARRAY_SIZE(netdev_lock_type) - 1;
}

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static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
						 unsigned short dev_type)
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{
	int i;

	i = netdev_lock_pos(dev_type);
	lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
				   netdev_lock_name[i]);
}
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static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
{
	int i;

	i = netdev_lock_pos(dev->type);
	lockdep_set_class_and_name(&dev->addr_list_lock,
				   &netdev_addr_lock_key[i],
				   netdev_lock_name[i]);
}
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#else
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static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
						 unsigned short dev_type)
{
}
static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
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{
}
#endif
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/*******************************************************************************

		Protocol management and registration routines

*******************************************************************************/

/*
 *	Add a protocol ID to the list. Now that the input handler is
 *	smarter we can dispense with all the messy stuff that used to be
 *	here.
 *
 *	BEWARE!!! Protocol handlers, mangling input packets,
 *	MUST BE last in hash buckets and checking protocol handlers
 *	MUST start from promiscuous ptype_all chain in net_bh.
 *	It is true now, do not change it.
 *	Explanation follows: if protocol handler, mangling packet, will
 *	be the first on list, it is not able to sense, that packet
 *	is cloned and should be copied-on-write, so that it will
 *	change it and subsequent readers will get broken packet.
 *							--ANK (980803)
 */

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static inline struct list_head *ptype_head(const struct packet_type *pt)
{
	if (pt->type == htons(ETH_P_ALL))
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		return pt->dev ? &pt->dev->ptype_all : &ptype_all;
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	else
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		return pt->dev ? &pt->dev->ptype_specific :
				 &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
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}

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/**
 *	dev_add_pack - add packet handler
 *	@pt: packet type declaration
 *
 *	Add a protocol handler to the networking stack. The passed &packet_type
 *	is linked into kernel lists and may not be freed until it has been
 *	removed from the kernel lists.
 *
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 *	This call does not sleep therefore it can not
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 *	guarantee all CPU's that are in middle of receiving packets
 *	will see the new packet type (until the next received packet).
 */

void dev_add_pack(struct packet_type *pt)
{
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	struct list_head *head = ptype_head(pt);
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	spin_lock(&ptype_lock);
	list_add_rcu(&pt->list, head);
	spin_unlock(&ptype_lock);
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}
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EXPORT_SYMBOL(dev_add_pack);
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/**
 *	__dev_remove_pack	 - remove packet handler
 *	@pt: packet type declaration
 *
 *	Remove a protocol handler that was previously added to the kernel
 *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
 *	from the kernel lists and can be freed or reused once this function
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 *	returns.
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 *
 *      The packet type might still be in use by receivers
 *	and must not be freed until after all the CPU's have gone
 *	through a quiescent state.
 */
void __dev_remove_pack(struct packet_type *pt)
{
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	struct list_head *head = ptype_head(pt);
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	struct packet_type *pt1;

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	spin_lock(&ptype_lock);
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	list_for_each_entry(pt1, head, list) {
		if (pt == pt1) {
			list_del_rcu(&pt->list);
			goto out;
		}
	}

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	pr_warn("dev_remove_pack: %p not found\n", pt);
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out:
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	spin_unlock(&ptype_lock);
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}
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EXPORT_SYMBOL(__dev_remove_pack);

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/**
 *	dev_remove_pack	 - remove packet handler
 *	@pt: packet type declaration
 *
 *	Remove a protocol handler that was previously added to the kernel
 *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
 *	from the kernel lists and can be freed or reused once this function
 *	returns.
 *
 *	This call sleeps to guarantee that no CPU is looking at the packet
 *	type after return.
 */
void dev_remove_pack(struct packet_type *pt)
{
	__dev_remove_pack(pt);
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	synchronize_net();
}
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EXPORT_SYMBOL(dev_remove_pack);
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/**
 *	dev_add_offload - register offload handlers
 *	@po: protocol offload declaration
 *
 *	Add protocol offload handlers to the networking stack. The passed
 *	&proto_offload is linked into kernel lists and may not be freed until
 *	it has been removed from the kernel lists.
 *
 *	This call does not sleep therefore it can not
 *	guarantee all CPU's that are in middle of receiving packets
 *	will see the new offload handlers (until the next received packet).
 */
void dev_add_offload(struct packet_offload *po)
{
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	struct packet_offload *elem;
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	spin_lock(&offload_lock);
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	list_for_each_entry(elem, &offload_base, list) {
		if (po->priority < elem->priority)
			break;
	}
	list_add_rcu(&po->list, elem->list.prev);
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	spin_unlock(&offload_lock);
}
EXPORT_SYMBOL(dev_add_offload);

/**
 *	__dev_remove_offload	 - remove offload handler
 *	@po: packet offload declaration
 *
 *	Remove a protocol offload handler that was previously added to the
 *	kernel offload handlers by dev_add_offload(). The passed &offload_type
 *	is removed from the kernel lists and can be freed or reused once this
 *	function returns.
 *
 *      The packet type might still be in use by receivers
 *	and must not be freed until after all the CPU's have gone
 *	through a quiescent state.
 */
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static void __dev_remove_offload(struct packet_offload *po)
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{
	struct list_head *head = &offload_base;
	struct packet_offload *po1;

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	spin_lock(&offload_lock);
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	list_for_each_entry(po1, head, list) {
		if (po == po1) {
			list_del_rcu(&po->list);
			goto out;
		}
	}

	pr_warn("dev_remove_offload: %p not found\n", po);
out:
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	spin_unlock(&offload_lock);
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}

/**
 *	dev_remove_offload	 - remove packet offload handler
 *	@po: packet offload declaration
 *
 *	Remove a packet offload handler that was previously added to the kernel
 *	offload handlers by dev_add_offload(). The passed &offload_type is
 *	removed from the kernel lists and can be freed or reused once this
 *	function returns.
 *
 *	This call sleeps to guarantee that no CPU is looking at the packet
 *	type after return.
 */
void dev_remove_offload(struct packet_offload *po)
{
	__dev_remove_offload(po);

	synchronize_net();
}
EXPORT_SYMBOL(dev_remove_offload);

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/******************************************************************************

		      Device Boot-time Settings Routines

*******************************************************************************/

/* Boot time configuration table */
static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX];

/**
 *	netdev_boot_setup_add	- add new setup entry
 *	@name: name of the device
 *	@map: configured settings for the device
 *
 *	Adds new setup entry to the dev_boot_setup list.  The function
 *	returns 0 on error and 1 on success.  This is a generic routine to
 *	all netdevices.
 */
static int netdev_boot_setup_add(char *name, struct ifmap *map)
{
	struct netdev_boot_setup *s;
	int i;

	s = dev_boot_setup;
	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
		if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
			memset(s[i].name, 0, sizeof(s[i].name));
567
			strlcpy(s[i].name, name, IFNAMSIZ);
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			memcpy(&s[i].map, map, sizeof(s[i].map));
			break;
		}
	}

	return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1;
}

/**
 *	netdev_boot_setup_check	- check boot time settings
 *	@dev: the netdevice
 *
 * 	Check boot time settings for the device.
 *	The found settings are set for the device to be used
 *	later in the device probing.
 *	Returns 0 if no settings found, 1 if they are.
 */
int netdev_boot_setup_check(struct net_device *dev)
{
	struct netdev_boot_setup *s = dev_boot_setup;
	int i;

	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
		if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
592
		    !strcmp(dev->name, s[i].name)) {
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			dev->irq 	= s[i].map.irq;
			dev->base_addr 	= s[i].map.base_addr;
			dev->mem_start 	= s[i].map.mem_start;
			dev->mem_end 	= s[i].map.mem_end;
			return 1;
		}
	}
	return 0;
}
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EXPORT_SYMBOL(netdev_boot_setup_check);
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/**
 *	netdev_boot_base	- get address from boot time settings
 *	@prefix: prefix for network device
 *	@unit: id for network device
 *
 * 	Check boot time settings for the base address of device.
 *	The found settings are set for the device to be used
 *	later in the device probing.
 *	Returns 0 if no settings found.
 */
unsigned long netdev_boot_base(const char *prefix, int unit)
{
	const struct netdev_boot_setup *s = dev_boot_setup;
	char name[IFNAMSIZ];
	int i;

	sprintf(name, "%s%d", prefix, unit);

	/*
	 * If device already registered then return base of 1
	 * to indicate not to probe for this interface
	 */
627
	if (__dev_get_by_name(&init_net, name))
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		return 1;

	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++)
		if (!strcmp(name, s[i].name))
			return s[i].map.base_addr;
	return 0;
}

/*
 * Saves at boot time configured settings for any netdevice.
 */
int __init netdev_boot_setup(char *str)
{
	int ints[5];
	struct ifmap map;

	str = get_options(str, ARRAY_SIZE(ints), ints);
	if (!str || !*str)
		return 0;

	/* Save settings */
	memset(&map, 0, sizeof(map));
	if (ints[0] > 0)
		map.irq = ints[1];
	if (ints[0] > 1)
		map.base_addr = ints[2];
	if (ints[0] > 2)
		map.mem_start = ints[3];
	if (ints[0] > 3)
		map.mem_end = ints[4];

	/* Add new entry to the list */
	return netdev_boot_setup_add(str, &map);
}

__setup("netdev=", netdev_boot_setup);

/*******************************************************************************

			    Device Interface Subroutines

*******************************************************************************/

671 672 673 674 675 676 677 678 679 680 681 682 683
/**
 *	dev_get_iflink	- get 'iflink' value of a interface
 *	@dev: targeted interface
 *
 *	Indicates the ifindex the interface is linked to.
 *	Physical interfaces have the same 'ifindex' and 'iflink' values.
 */

int dev_get_iflink(const struct net_device *dev)
{
	if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
		return dev->netdev_ops->ndo_get_iflink(dev);

684
	return dev->ifindex;
685 686 687
}
EXPORT_SYMBOL(dev_get_iflink);

688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713
/**
 *	dev_fill_metadata_dst - Retrieve tunnel egress information.
 *	@dev: targeted interface
 *	@skb: The packet.
 *
 *	For better visibility of tunnel traffic OVS needs to retrieve
 *	egress tunnel information for a packet. Following API allows
 *	user to get this info.
 */
int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
{
	struct ip_tunnel_info *info;

	if (!dev->netdev_ops  || !dev->netdev_ops->ndo_fill_metadata_dst)
		return -EINVAL;

	info = skb_tunnel_info_unclone(skb);
	if (!info)
		return -ENOMEM;
	if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
		return -EINVAL;

	return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
}
EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);

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/**
 *	__dev_get_by_name	- find a device by its name
716
 *	@net: the applicable net namespace
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 *	@name: name to find
 *
 *	Find an interface by name. Must be called under RTNL semaphore
 *	or @dev_base_lock. If the name is found a pointer to the device
 *	is returned. If the name is not found then %NULL is returned. The
 *	reference counters are not incremented so the caller must be
 *	careful with locks.
 */

726
struct net_device *__dev_get_by_name(struct net *net, const char *name)
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{
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	struct net_device *dev;
	struct hlist_head *head = dev_name_hash(net, name);
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731
	hlist_for_each_entry(dev, head, name_hlist)
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		if (!strncmp(dev->name, name, IFNAMSIZ))
			return dev;
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	return NULL;
}
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EXPORT_SYMBOL(__dev_get_by_name);
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739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755
/**
 *	dev_get_by_name_rcu	- find a device by its name
 *	@net: the applicable net namespace
 *	@name: name to find
 *
 *	Find an interface by name.
 *	If the name is found a pointer to the device is returned.
 * 	If the name is not found then %NULL is returned.
 *	The reference counters are not incremented so the caller must be
 *	careful with locks. The caller must hold RCU lock.
 */

struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
{
	struct net_device *dev;
	struct hlist_head *head = dev_name_hash(net, name);

756
	hlist_for_each_entry_rcu(dev, head, name_hlist)
757 758 759 760 761 762 763
		if (!strncmp(dev->name, name, IFNAMSIZ))
			return dev;

	return NULL;
}
EXPORT_SYMBOL(dev_get_by_name_rcu);

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/**
 *	dev_get_by_name		- find a device by its name
766
 *	@net: the applicable net namespace
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 *	@name: name to find
 *
 *	Find an interface by name. This can be called from any
 *	context and does its own locking. The returned handle has
 *	the usage count incremented and the caller must use dev_put() to
 *	release it when it is no longer needed. %NULL is returned if no
 *	matching device is found.
 */

776
struct net_device *dev_get_by_name(struct net *net, const char *name)
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{
	struct net_device *dev;

780 781
	rcu_read_lock();
	dev = dev_get_by_name_rcu(net, name);
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	if (dev)
		dev_hold(dev);
784
	rcu_read_unlock();
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	return dev;
}
E
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EXPORT_SYMBOL(dev_get_by_name);
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/**
 *	__dev_get_by_index - find a device by its ifindex
791
 *	@net: the applicable net namespace
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 *	@ifindex: index of device
 *
 *	Search for an interface by index. Returns %NULL if the device
 *	is not found or a pointer to the device. The device has not
 *	had its reference counter increased so the caller must be careful
 *	about locking. The caller must hold either the RTNL semaphore
 *	or @dev_base_lock.
 */

801
struct net_device *__dev_get_by_index(struct net *net, int ifindex)
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{
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	struct net_device *dev;
	struct hlist_head *head = dev_index_hash(net, ifindex);
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805

806
	hlist_for_each_entry(dev, head, index_hlist)
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		if (dev->ifindex == ifindex)
			return dev;
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	return NULL;
}
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EXPORT_SYMBOL(__dev_get_by_index);
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814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829
/**
 *	dev_get_by_index_rcu - find a device by its ifindex
 *	@net: the applicable net namespace
 *	@ifindex: index of device
 *
 *	Search for an interface by index. Returns %NULL if the device
 *	is not found or a pointer to the device. The device has not
 *	had its reference counter increased so the caller must be careful
 *	about locking. The caller must hold RCU lock.
 */

struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
{
	struct net_device *dev;
	struct hlist_head *head = dev_index_hash(net, ifindex);

830
	hlist_for_each_entry_rcu(dev, head, index_hlist)
831 832 833 834 835 836 837
		if (dev->ifindex == ifindex)
			return dev;

	return NULL;
}
EXPORT_SYMBOL(dev_get_by_index_rcu);

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/**
 *	dev_get_by_index - find a device by its ifindex
841
 *	@net: the applicable net namespace
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 *	@ifindex: index of device
 *
 *	Search for an interface by index. Returns NULL if the device
 *	is not found or a pointer to the device. The device returned has
 *	had a reference added and the pointer is safe until the user calls
 *	dev_put to indicate they have finished with it.
 */

850
struct net_device *dev_get_by_index(struct net *net, int ifindex)
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{
	struct net_device *dev;

854 855
	rcu_read_lock();
	dev = dev_get_by_index_rcu(net, ifindex);
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	if (dev)
		dev_hold(dev);
858
	rcu_read_unlock();
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	return dev;
}
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EXPORT_SYMBOL(dev_get_by_index);
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863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896
/**
 *	netdev_get_name - get a netdevice name, knowing its ifindex.
 *	@net: network namespace
 *	@name: a pointer to the buffer where the name will be stored.
 *	@ifindex: the ifindex of the interface to get the name from.
 *
 *	The use of raw_seqcount_begin() and cond_resched() before
 *	retrying is required as we want to give the writers a chance
 *	to complete when CONFIG_PREEMPT is not set.
 */
int netdev_get_name(struct net *net, char *name, int ifindex)
{
	struct net_device *dev;
	unsigned int seq;

retry:
	seq = raw_seqcount_begin(&devnet_rename_seq);
	rcu_read_lock();
	dev = dev_get_by_index_rcu(net, ifindex);
	if (!dev) {
		rcu_read_unlock();
		return -ENODEV;
	}

	strcpy(name, dev->name);
	rcu_read_unlock();
	if (read_seqcount_retry(&devnet_rename_seq, seq)) {
		cond_resched();
		goto retry;
	}

	return 0;
}

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/**
898
 *	dev_getbyhwaddr_rcu - find a device by its hardware address
899
 *	@net: the applicable net namespace
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 *	@type: media type of device
 *	@ha: hardware address
 *
 *	Search for an interface by MAC address. Returns NULL if the device
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 *	is not found or a pointer to the device.
 *	The caller must hold RCU or RTNL.
906
 *	The returned device has not had its ref count increased
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 *	and the caller must therefore be careful about locking
 *
 */

911 912
struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
				       const char *ha)
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{
	struct net_device *dev;

916
	for_each_netdev_rcu(net, dev)
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		if (dev->type == type &&
		    !memcmp(dev->dev_addr, ha, dev->addr_len))
919 920 921
			return dev;

	return NULL;
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}
923
EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
924

925
struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type)
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{
	struct net_device *dev;

929
	ASSERT_RTNL();
930
	for_each_netdev(net, dev)
931
		if (dev->type == type)
932 933 934
			return dev;

	return NULL;
935 936 937
}
EXPORT_SYMBOL(__dev_getfirstbyhwtype);

938
struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
939
{
940
	struct net_device *dev, *ret = NULL;
941

942 943 944 945 946 947 948 949 950
	rcu_read_lock();
	for_each_netdev_rcu(net, dev)
		if (dev->type == type) {
			dev_hold(dev);
			ret = dev;
			break;
		}
	rcu_read_unlock();
	return ret;
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}
EXPORT_SYMBOL(dev_getfirstbyhwtype);

/**
955
 *	__dev_get_by_flags - find any device with given flags
956
 *	@net: the applicable net namespace
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 *	@if_flags: IFF_* values
 *	@mask: bitmask of bits in if_flags to check
 *
 *	Search for any interface with the given flags. Returns NULL if a device
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Eric Dumazet 已提交
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 *	is not found or a pointer to the device. Must be called inside
962
 *	rtnl_lock(), and result refcount is unchanged.
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 */

965 966
struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
				      unsigned short mask)
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{
968
	struct net_device *dev, *ret;
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970 971
	ASSERT_RTNL();

972
	ret = NULL;
973
	for_each_netdev(net, dev) {
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		if (((dev->flags ^ if_flags) & mask) == 0) {
975
			ret = dev;
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			break;
		}
	}
979
	return ret;
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}
981
EXPORT_SYMBOL(__dev_get_by_flags);
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/**
 *	dev_valid_name - check if name is okay for network device
 *	@name: name string
 *
 *	Network device names need to be valid file names to
988 989
 *	to allow sysfs to work.  We also disallow any kind of
 *	whitespace.
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 */
991
bool dev_valid_name(const char *name)
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{
993
	if (*name == '\0')
994
		return false;
995
	if (strlen(name) >= IFNAMSIZ)
996
		return false;
997
	if (!strcmp(name, ".") || !strcmp(name, ".."))
998
		return false;
999 1000

	while (*name) {
1001
		if (*name == '/' || *name == ':' || isspace(*name))
1002
			return false;
1003 1004
		name++;
	}
1005
	return true;
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}
E
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1007
EXPORT_SYMBOL(dev_valid_name);
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/**
1010 1011
 *	__dev_alloc_name - allocate a name for a device
 *	@net: network namespace to allocate the device name in
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 *	@name: name format string
1013
 *	@buf:  scratch buffer and result name string
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 *
 *	Passed a format string - eg "lt%d" it will try and find a suitable
S
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 *	id. It scans list of devices to build up a free map, then chooses
 *	the first empty slot. The caller must hold the dev_base or rtnl lock
 *	while allocating the name and adding the device in order to avoid
 *	duplicates.
 *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
 *	Returns the number of the unit assigned or a negative errno code.
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 */

1024
static int __dev_alloc_name(struct net *net, const char *name, char *buf)
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{
	int i = 0;
	const char *p;
	const int max_netdevices = 8*PAGE_SIZE;
S
Stephen Hemminger 已提交
1029
	unsigned long *inuse;
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	struct net_device *d;

	p = strnchr(name, IFNAMSIZ-1, '%');
	if (p) {
		/*
		 * Verify the string as this thing may have come from
		 * the user.  There must be either one "%d" and no other "%"
		 * characters.
		 */
		if (p[1] != 'd' || strchr(p + 2, '%'))
			return -EINVAL;

		/* Use one page as a bit array of possible slots */
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Stephen Hemminger 已提交
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		inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
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		if (!inuse)
			return -ENOMEM;

1047
		for_each_netdev(net, d) {
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			if (!sscanf(d->name, name, &i))
				continue;
			if (i < 0 || i >= max_netdevices)
				continue;

			/*  avoid cases where sscanf is not exact inverse of printf */
1054
			snprintf(buf, IFNAMSIZ, name, i);
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			if (!strncmp(buf, d->name, IFNAMSIZ))
				set_bit(i, inuse);
		}

		i = find_first_zero_bit(inuse, max_netdevices);
		free_page((unsigned long) inuse);
	}

1063 1064
	if (buf != name)
		snprintf(buf, IFNAMSIZ, name, i);
1065
	if (!__dev_get_by_name(net, buf))
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		return i;

	/* It is possible to run out of possible slots
	 * when the name is long and there isn't enough space left
	 * for the digits, or if all bits are used.
	 */
	return -ENFILE;
}

1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094
/**
 *	dev_alloc_name - allocate a name for a device
 *	@dev: device
 *	@name: name format string
 *
 *	Passed a format string - eg "lt%d" it will try and find a suitable
 *	id. It scans list of devices to build up a free map, then chooses
 *	the first empty slot. The caller must hold the dev_base or rtnl lock
 *	while allocating the name and adding the device in order to avoid
 *	duplicates.
 *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
 *	Returns the number of the unit assigned or a negative errno code.
 */

int dev_alloc_name(struct net_device *dev, const char *name)
{
	char buf[IFNAMSIZ];
	struct net *net;
	int ret;

1095 1096
	BUG_ON(!dev_net(dev));
	net = dev_net(dev);
1097 1098 1099 1100 1101
	ret = __dev_alloc_name(net, name, buf);
	if (ret >= 0)
		strlcpy(dev->name, buf, IFNAMSIZ);
	return ret;
}
E
Eric Dumazet 已提交
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EXPORT_SYMBOL(dev_alloc_name);
1103

1104 1105 1106
static int dev_alloc_name_ns(struct net *net,
			     struct net_device *dev,
			     const char *name)
1107
{
1108 1109
	char buf[IFNAMSIZ];
	int ret;
1110

1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121
	ret = __dev_alloc_name(net, name, buf);
	if (ret >= 0)
		strlcpy(dev->name, buf, IFNAMSIZ);
	return ret;
}

static int dev_get_valid_name(struct net *net,
			      struct net_device *dev,
			      const char *name)
{
	BUG_ON(!net);
1122

1123 1124 1125
	if (!dev_valid_name(name))
		return -EINVAL;

1126
	if (strchr(name, '%'))
1127
		return dev_alloc_name_ns(net, dev, name);
1128 1129
	else if (__dev_get_by_name(net, name))
		return -EEXIST;
1130 1131
	else if (dev->name != name)
		strlcpy(dev->name, name, IFNAMSIZ);
1132 1133 1134

	return 0;
}
L
Linus Torvalds 已提交
1135 1136 1137 1138 1139 1140 1141 1142 1143

/**
 *	dev_change_name - change name of a device
 *	@dev: device
 *	@newname: name (or format string) must be at least IFNAMSIZ
 *
 *	Change name of a device, can pass format strings "eth%d".
 *	for wildcarding.
 */
1144
int dev_change_name(struct net_device *dev, const char *newname)
L
Linus Torvalds 已提交
1145
{
1146
	unsigned char old_assign_type;
1147
	char oldname[IFNAMSIZ];
L
Linus Torvalds 已提交
1148
	int err = 0;
1149
	int ret;
1150
	struct net *net;
L
Linus Torvalds 已提交
1151 1152

	ASSERT_RTNL();
1153
	BUG_ON(!dev_net(dev));
L
Linus Torvalds 已提交
1154

1155
	net = dev_net(dev);
L
Linus Torvalds 已提交
1156 1157 1158
	if (dev->flags & IFF_UP)
		return -EBUSY;

1159
	write_seqcount_begin(&devnet_rename_seq);
1160 1161

	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1162
		write_seqcount_end(&devnet_rename_seq);
1163
		return 0;
1164
	}
1165

1166 1167
	memcpy(oldname, dev->name, IFNAMSIZ);

1168
	err = dev_get_valid_name(net, dev, newname);
1169
	if (err < 0) {
1170
		write_seqcount_end(&devnet_rename_seq);
1171
		return err;
1172
	}
L
Linus Torvalds 已提交
1173

1174 1175 1176
	if (oldname[0] && !strchr(oldname, '%'))
		netdev_info(dev, "renamed from %s\n", oldname);

1177 1178 1179
	old_assign_type = dev->name_assign_type;
	dev->name_assign_type = NET_NAME_RENAMED;

1180
rollback:
1181 1182 1183
	ret = device_rename(&dev->dev, dev->name);
	if (ret) {
		memcpy(dev->name, oldname, IFNAMSIZ);
1184
		dev->name_assign_type = old_assign_type;
1185
		write_seqcount_end(&devnet_rename_seq);
1186
		return ret;
1187
	}
1188

1189
	write_seqcount_end(&devnet_rename_seq);
1190

1191 1192
	netdev_adjacent_rename_links(dev, oldname);

1193
	write_lock_bh(&dev_base_lock);
1194
	hlist_del_rcu(&dev->name_hlist);
1195 1196 1197 1198 1199 1200
	write_unlock_bh(&dev_base_lock);

	synchronize_rcu();

	write_lock_bh(&dev_base_lock);
	hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
1201 1202
	write_unlock_bh(&dev_base_lock);

1203
	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1204 1205 1206
	ret = notifier_to_errno(ret);

	if (ret) {
1207 1208
		/* err >= 0 after dev_alloc_name() or stores the first errno */
		if (err >= 0) {
1209
			err = ret;
1210
			write_seqcount_begin(&devnet_rename_seq);
1211
			memcpy(dev->name, oldname, IFNAMSIZ);
1212
			memcpy(oldname, newname, IFNAMSIZ);
1213 1214
			dev->name_assign_type = old_assign_type;
			old_assign_type = NET_NAME_RENAMED;
1215
			goto rollback;
1216
		} else {
1217
			pr_err("%s: name change rollback failed: %d\n",
1218
			       dev->name, ret);
1219 1220
		}
	}
L
Linus Torvalds 已提交
1221 1222 1223 1224

	return err;
}

1225 1226 1227 1228
/**
 *	dev_set_alias - change ifalias of a device
 *	@dev: device
 *	@alias: name up to IFALIASZ
1229
 *	@len: limit of bytes to copy from info
1230 1231 1232 1233 1234
 *
 *	Set ifalias for a device,
 */
int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
{
1235 1236
	char *new_ifalias;

1237 1238 1239 1240 1241
	ASSERT_RTNL();

	if (len >= IFALIASZ)
		return -EINVAL;

1242
	if (!len) {
1243 1244
		kfree(dev->ifalias);
		dev->ifalias = NULL;
1245 1246 1247
		return 0;
	}

1248 1249
	new_ifalias = krealloc(dev->ifalias, len + 1, GFP_KERNEL);
	if (!new_ifalias)
1250
		return -ENOMEM;
1251
	dev->ifalias = new_ifalias;
1252 1253 1254 1255 1256 1257

	strlcpy(dev->ifalias, alias, len+1);
	return len;
}


1258
/**
S
Stephen Hemminger 已提交
1259
 *	netdev_features_change - device changes features
1260 1261 1262 1263 1264 1265
 *	@dev: device to cause notification
 *
 *	Called to indicate a device has changed features.
 */
void netdev_features_change(struct net_device *dev)
{
1266
	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1267 1268 1269
}
EXPORT_SYMBOL(netdev_features_change);

L
Linus Torvalds 已提交
1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280
/**
 *	netdev_state_change - device changes state
 *	@dev: device to cause notification
 *
 *	Called to indicate a device has changed state. This function calls
 *	the notifier chains for netdev_chain and sends a NEWLINK message
 *	to the routing socket.
 */
void netdev_state_change(struct net_device *dev)
{
	if (dev->flags & IFF_UP) {
1281 1282 1283 1284 1285
		struct netdev_notifier_change_info change_info;

		change_info.flags_changed = 0;
		call_netdevice_notifiers_info(NETDEV_CHANGE, dev,
					      &change_info.info);
1286
		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);
L
Linus Torvalds 已提交
1287 1288
	}
}
E
Eric Dumazet 已提交
1289
EXPORT_SYMBOL(netdev_state_change);
L
Linus Torvalds 已提交
1290

1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301
/**
 * 	netdev_notify_peers - notify network peers about existence of @dev
 * 	@dev: network device
 *
 * Generate traffic such that interested network peers are aware of
 * @dev, such as by generating a gratuitous ARP. This may be used when
 * a device wants to inform the rest of the network about some sort of
 * reconfiguration such as a failover event or virtual machine
 * migration.
 */
void netdev_notify_peers(struct net_device *dev)
1302
{
1303 1304 1305
	rtnl_lock();
	call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
	rtnl_unlock();
1306
}
1307
EXPORT_SYMBOL(netdev_notify_peers);
1308

1309
static int __dev_open(struct net_device *dev)
L
Linus Torvalds 已提交
1310
{
1311
	const struct net_device_ops *ops = dev->netdev_ops;
1312
	int ret;
L
Linus Torvalds 已提交
1313

1314 1315
	ASSERT_RTNL();

L
Linus Torvalds 已提交
1316 1317 1318
	if (!netif_device_present(dev))
		return -ENODEV;

1319 1320 1321 1322
	/* Block netpoll from trying to do any rx path servicing.
	 * If we don't do this there is a chance ndo_poll_controller
	 * or ndo_poll may be running while we open the device
	 */
1323
	netpoll_poll_disable(dev);
1324

1325 1326 1327 1328 1329
	ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
	ret = notifier_to_errno(ret);
	if (ret)
		return ret;

L
Linus Torvalds 已提交
1330
	set_bit(__LINK_STATE_START, &dev->state);
1331

1332 1333
	if (ops->ndo_validate_addr)
		ret = ops->ndo_validate_addr(dev);
1334

1335 1336
	if (!ret && ops->ndo_open)
		ret = ops->ndo_open(dev);
L
Linus Torvalds 已提交
1337

1338
	netpoll_poll_enable(dev);
1339

1340 1341 1342
	if (ret)
		clear_bit(__LINK_STATE_START, &dev->state);
	else {
L
Linus Torvalds 已提交
1343
		dev->flags |= IFF_UP;
1344
		dev_set_rx_mode(dev);
L
Linus Torvalds 已提交
1345
		dev_activate(dev);
1346
		add_device_randomness(dev->dev_addr, dev->addr_len);
L
Linus Torvalds 已提交
1347
	}
1348

L
Linus Torvalds 已提交
1349 1350 1351 1352
	return ret;
}

/**
1353 1354
 *	dev_open	- prepare an interface for use.
 *	@dev:	device to open
L
Linus Torvalds 已提交
1355
 *
1356 1357 1358 1359 1360 1361 1362
 *	Takes a device from down to up state. The device's private open
 *	function is invoked and then the multicast lists are loaded. Finally
 *	the device is moved into the up state and a %NETDEV_UP message is
 *	sent to the netdev notifier chain.
 *
 *	Calling this function on an active interface is a nop. On a failure
 *	a negative errno code is returned.
L
Linus Torvalds 已提交
1363
 */
1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374
int dev_open(struct net_device *dev)
{
	int ret;

	if (dev->flags & IFF_UP)
		return 0;

	ret = __dev_open(dev);
	if (ret < 0)
		return ret;

1375
	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1376 1377 1378 1379 1380 1381
	call_netdevice_notifiers(NETDEV_UP, dev);

	return ret;
}
EXPORT_SYMBOL(dev_open);

1382
static int __dev_close_many(struct list_head *head)
L
Linus Torvalds 已提交
1383
{
1384
	struct net_device *dev;
1385

1386
	ASSERT_RTNL();
1387 1388
	might_sleep();

1389
	list_for_each_entry(dev, head, close_list) {
1390
		/* Temporarily disable netpoll until the interface is down */
1391
		netpoll_poll_disable(dev);
1392

1393
		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
L
Linus Torvalds 已提交
1394

1395
		clear_bit(__LINK_STATE_START, &dev->state);
L
Linus Torvalds 已提交
1396

1397 1398 1399 1400 1401 1402
		/* Synchronize to scheduled poll. We cannot touch poll list, it
		 * can be even on different cpu. So just clear netif_running().
		 *
		 * dev->stop() will invoke napi_disable() on all of it's
		 * napi_struct instances on this device.
		 */
1403
		smp_mb__after_atomic(); /* Commit netif_running(). */
1404
	}
L
Linus Torvalds 已提交
1405

1406
	dev_deactivate_many(head);
1407

1408
	list_for_each_entry(dev, head, close_list) {
1409
		const struct net_device_ops *ops = dev->netdev_ops;
L
Linus Torvalds 已提交
1410

1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421
		/*
		 *	Call the device specific close. This cannot fail.
		 *	Only if device is UP
		 *
		 *	We allow it to be called even after a DETACH hot-plug
		 *	event.
		 */
		if (ops->ndo_stop)
			ops->ndo_stop(dev);

		dev->flags &= ~IFF_UP;
1422
		netpoll_poll_enable(dev);
1423 1424 1425 1426 1427 1428 1429
	}

	return 0;
}

static int __dev_close(struct net_device *dev)
{
1430
	int retval;
1431 1432
	LIST_HEAD(single);

1433
	list_add(&dev->close_list, &single);
1434 1435
	retval = __dev_close_many(&single);
	list_del(&single);
1436

1437
	return retval;
1438 1439
}

1440
int dev_close_many(struct list_head *head, bool unlink)
1441 1442
{
	struct net_device *dev, *tmp;
L
Linus Torvalds 已提交
1443

1444 1445
	/* Remove the devices that don't need to be closed */
	list_for_each_entry_safe(dev, tmp, head, close_list)
1446
		if (!(dev->flags & IFF_UP))
1447
			list_del_init(&dev->close_list);
1448 1449

	__dev_close_many(head);
L
Linus Torvalds 已提交
1450

1451
	list_for_each_entry_safe(dev, tmp, head, close_list) {
1452
		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1453
		call_netdevice_notifiers(NETDEV_DOWN, dev);
1454 1455
		if (unlink)
			list_del_init(&dev->close_list);
1456
	}
1457 1458 1459

	return 0;
}
1460
EXPORT_SYMBOL(dev_close_many);
1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472

/**
 *	dev_close - shutdown an interface.
 *	@dev: device to shutdown
 *
 *	This function moves an active device into down state. A
 *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
 *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
 *	chain.
 */
int dev_close(struct net_device *dev)
{
1473 1474
	if (dev->flags & IFF_UP) {
		LIST_HEAD(single);
L
Linus Torvalds 已提交
1475

1476
		list_add(&dev->close_list, &single);
1477
		dev_close_many(&single, true);
1478 1479
		list_del(&single);
	}
1480
	return 0;
L
Linus Torvalds 已提交
1481
}
E
Eric Dumazet 已提交
1482
EXPORT_SYMBOL(dev_close);
L
Linus Torvalds 已提交
1483 1484


1485 1486 1487 1488 1489 1490 1491 1492 1493 1494
/**
 *	dev_disable_lro - disable Large Receive Offload on a device
 *	@dev: device
 *
 *	Disable Large Receive Offload (LRO) on a net device.  Must be
 *	called under RTNL.  This is needed if received packets may be
 *	forwarded to another interface.
 */
void dev_disable_lro(struct net_device *dev)
{
1495 1496
	struct net_device *lower_dev;
	struct list_head *iter;
1497

M
Michał Mirosław 已提交
1498 1499
	dev->wanted_features &= ~NETIF_F_LRO;
	netdev_update_features(dev);
1500

1501 1502
	if (unlikely(dev->features & NETIF_F_LRO))
		netdev_WARN(dev, "failed to disable LRO!\n");
1503 1504 1505

	netdev_for_each_lower_dev(dev, lower_dev, iter)
		dev_disable_lro(lower_dev);
1506 1507 1508
}
EXPORT_SYMBOL(dev_disable_lro);

1509 1510 1511 1512 1513 1514 1515 1516
static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
				   struct net_device *dev)
{
	struct netdev_notifier_info info;

	netdev_notifier_info_init(&info, dev);
	return nb->notifier_call(nb, val, &info);
}
1517

1518 1519
static int dev_boot_phase = 1;

L
Linus Torvalds 已提交
1520 1521 1522 1523 1524 1525 1526 1527 1528 1529
/**
 *	register_netdevice_notifier - register a network notifier block
 *	@nb: notifier
 *
 *	Register a notifier to be called when network device events occur.
 *	The notifier passed is linked into the kernel structures and must
 *	not be reused until it has been unregistered. A negative errno code
 *	is returned on a failure.
 *
 * 	When registered all registration and up events are replayed
1530
 *	to the new notifier to allow device to have a race free
L
Linus Torvalds 已提交
1531 1532 1533 1534 1535 1536
 *	view of the network device list.
 */

int register_netdevice_notifier(struct notifier_block *nb)
{
	struct net_device *dev;
1537
	struct net_device *last;
1538
	struct net *net;
L
Linus Torvalds 已提交
1539 1540 1541
	int err;

	rtnl_lock();
1542
	err = raw_notifier_chain_register(&netdev_chain, nb);
1543 1544
	if (err)
		goto unlock;
1545 1546 1547 1548
	if (dev_boot_phase)
		goto unlock;
	for_each_net(net) {
		for_each_netdev(net, dev) {
1549
			err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1550 1551 1552 1553 1554 1555
			err = notifier_to_errno(err);
			if (err)
				goto rollback;

			if (!(dev->flags & IFF_UP))
				continue;
L
Linus Torvalds 已提交
1556

1557
			call_netdevice_notifier(nb, NETDEV_UP, dev);
1558
		}
L
Linus Torvalds 已提交
1559
	}
1560 1561

unlock:
L
Linus Torvalds 已提交
1562 1563
	rtnl_unlock();
	return err;
1564 1565 1566

rollback:
	last = dev;
1567 1568 1569
	for_each_net(net) {
		for_each_netdev(net, dev) {
			if (dev == last)
1570
				goto outroll;
1571

1572
			if (dev->flags & IFF_UP) {
1573 1574 1575
				call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
							dev);
				call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1576
			}
1577
			call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1578 1579
		}
	}
1580

1581
outroll:
1582
	raw_notifier_chain_unregister(&netdev_chain, nb);
1583
	goto unlock;
L
Linus Torvalds 已提交
1584
}
E
Eric Dumazet 已提交
1585
EXPORT_SYMBOL(register_netdevice_notifier);
L
Linus Torvalds 已提交
1586 1587 1588 1589 1590 1591 1592 1593 1594

/**
 *	unregister_netdevice_notifier - unregister a network notifier block
 *	@nb: notifier
 *
 *	Unregister a notifier previously registered by
 *	register_netdevice_notifier(). The notifier is unlinked into the
 *	kernel structures and may then be reused. A negative errno code
 *	is returned on a failure.
1595 1596 1597 1598
 *
 * 	After unregistering unregister and down device events are synthesized
 *	for all devices on the device list to the removed notifier to remove
 *	the need for special case cleanup code.
L
Linus Torvalds 已提交
1599 1600 1601 1602
 */

int unregister_netdevice_notifier(struct notifier_block *nb)
{
1603 1604
	struct net_device *dev;
	struct net *net;
1605 1606 1607
	int err;

	rtnl_lock();
1608
	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1609 1610 1611 1612 1613 1614
	if (err)
		goto unlock;

	for_each_net(net) {
		for_each_netdev(net, dev) {
			if (dev->flags & IFF_UP) {
1615 1616 1617
				call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
							dev);
				call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1618
			}
1619
			call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1620 1621 1622
		}
	}
unlock:
1623 1624
	rtnl_unlock();
	return err;
L
Linus Torvalds 已提交
1625
}
E
Eric Dumazet 已提交
1626
EXPORT_SYMBOL(unregister_netdevice_notifier);
L
Linus Torvalds 已提交
1627

1628 1629 1630 1631 1632 1633 1634 1635 1636 1637
/**
 *	call_netdevice_notifiers_info - call all network notifier blocks
 *	@val: value passed unmodified to notifier function
 *	@dev: net_device pointer passed unmodified to notifier function
 *	@info: notifier information data
 *
 *	Call all network notifier blocks.  Parameters and return value
 *	are as for raw_notifier_call_chain().
 */

S
stephen hemminger 已提交
1638 1639 1640
static int call_netdevice_notifiers_info(unsigned long val,
					 struct net_device *dev,
					 struct netdev_notifier_info *info)
1641 1642 1643 1644 1645 1646
{
	ASSERT_RTNL();
	netdev_notifier_info_init(info, dev);
	return raw_notifier_call_chain(&netdev_chain, val, info);
}

L
Linus Torvalds 已提交
1647 1648 1649
/**
 *	call_netdevice_notifiers - call all network notifier blocks
 *      @val: value passed unmodified to notifier function
1650
 *      @dev: net_device pointer passed unmodified to notifier function
L
Linus Torvalds 已提交
1651 1652
 *
 *	Call all network notifier blocks.  Parameters and return value
1653
 *	are as for raw_notifier_call_chain().
L
Linus Torvalds 已提交
1654 1655
 */

1656
int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
L
Linus Torvalds 已提交
1657
{
1658 1659 1660
	struct netdev_notifier_info info;

	return call_netdevice_notifiers_info(val, dev, &info);
L
Linus Torvalds 已提交
1661
}
1662
EXPORT_SYMBOL(call_netdevice_notifiers);
L
Linus Torvalds 已提交
1663

1664
#ifdef CONFIG_NET_INGRESS
1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679
static struct static_key ingress_needed __read_mostly;

void net_inc_ingress_queue(void)
{
	static_key_slow_inc(&ingress_needed);
}
EXPORT_SYMBOL_GPL(net_inc_ingress_queue);

void net_dec_ingress_queue(void)
{
	static_key_slow_dec(&ingress_needed);
}
EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
#endif

D
Daniel Borkmann 已提交
1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695
#ifdef CONFIG_NET_EGRESS
static struct static_key egress_needed __read_mostly;

void net_inc_egress_queue(void)
{
	static_key_slow_inc(&egress_needed);
}
EXPORT_SYMBOL_GPL(net_inc_egress_queue);

void net_dec_egress_queue(void)
{
	static_key_slow_dec(&egress_needed);
}
EXPORT_SYMBOL_GPL(net_dec_egress_queue);
#endif

1696
static struct static_key netstamp_needed __read_mostly;
1697
#ifdef HAVE_JUMP_LABEL
1698
/* We are not allowed to call static_key_slow_dec() from irq context
1699
 * If net_disable_timestamp() is called from irq context, defer the
1700
 * static_key_slow_dec() calls.
1701 1702 1703
 */
static atomic_t netstamp_needed_deferred;
#endif
L
Linus Torvalds 已提交
1704 1705 1706

void net_enable_timestamp(void)
{
1707 1708 1709 1710 1711
#ifdef HAVE_JUMP_LABEL
	int deferred = atomic_xchg(&netstamp_needed_deferred, 0);

	if (deferred) {
		while (--deferred)
1712
			static_key_slow_dec(&netstamp_needed);
1713 1714 1715
		return;
	}
#endif
1716
	static_key_slow_inc(&netstamp_needed);
L
Linus Torvalds 已提交
1717
}
E
Eric Dumazet 已提交
1718
EXPORT_SYMBOL(net_enable_timestamp);
L
Linus Torvalds 已提交
1719 1720 1721

void net_disable_timestamp(void)
{
1722 1723 1724 1725 1726 1727
#ifdef HAVE_JUMP_LABEL
	if (in_interrupt()) {
		atomic_inc(&netstamp_needed_deferred);
		return;
	}
#endif
1728
	static_key_slow_dec(&netstamp_needed);
L
Linus Torvalds 已提交
1729
}
E
Eric Dumazet 已提交
1730
EXPORT_SYMBOL(net_disable_timestamp);
L
Linus Torvalds 已提交
1731

E
Eric Dumazet 已提交
1732
static inline void net_timestamp_set(struct sk_buff *skb)
L
Linus Torvalds 已提交
1733
{
T
Thomas Gleixner 已提交
1734
	skb->tstamp = 0;
1735
	if (static_key_false(&netstamp_needed))
1736
		__net_timestamp(skb);
L
Linus Torvalds 已提交
1737 1738
}

1739
#define net_timestamp_check(COND, SKB)			\
1740
	if (static_key_false(&netstamp_needed)) {		\
T
Thomas Gleixner 已提交
1741
		if ((COND) && !(SKB)->tstamp)	\
1742 1743
			__net_timestamp(SKB);		\
	}						\
E
Eric Dumazet 已提交
1744

1745
bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763
{
	unsigned int len;

	if (!(dev->flags & IFF_UP))
		return false;

	len = dev->mtu + dev->hard_header_len + VLAN_HLEN;
	if (skb->len <= len)
		return true;

	/* if TSO is enabled, we don't care about the length as the packet
	 * could be forwarded without being segmented before
	 */
	if (skb_is_gso(skb))
		return true;

	return false;
}
1764
EXPORT_SYMBOL_GPL(is_skb_forwardable);
1765

H
Herbert Xu 已提交
1766 1767
int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
{
1768
	int ret = ____dev_forward_skb(dev, skb);
H
Herbert Xu 已提交
1769

1770 1771 1772 1773
	if (likely(!ret)) {
		skb->protocol = eth_type_trans(skb, dev);
		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
	}
H
Herbert Xu 已提交
1774

1775
	return ret;
H
Herbert Xu 已提交
1776 1777 1778
}
EXPORT_SYMBOL_GPL(__dev_forward_skb);

1779 1780 1781 1782 1783 1784 1785 1786
/**
 * dev_forward_skb - loopback an skb to another netif
 *
 * @dev: destination network device
 * @skb: buffer to forward
 *
 * return values:
 *	NET_RX_SUCCESS	(no congestion)
1787
 *	NET_RX_DROP     (packet was dropped, but freed)
1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798
 *
 * dev_forward_skb can be used for injecting an skb from the
 * start_xmit function of one device into the receive queue
 * of another device.
 *
 * The receiving device may be in another namespace, so
 * we have to clear all information in the skb that could
 * impact namespace isolation.
 */
int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
{
H
Herbert Xu 已提交
1799
	return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
1800 1801 1802
}
EXPORT_SYMBOL_GPL(dev_forward_skb);

1803 1804 1805 1806
static inline int deliver_skb(struct sk_buff *skb,
			      struct packet_type *pt_prev,
			      struct net_device *orig_dev)
{
1807 1808
	if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
		return -ENOMEM;
1809 1810 1811 1812
	atomic_inc(&skb->users);
	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
}

1813 1814
static inline void deliver_ptype_list_skb(struct sk_buff *skb,
					  struct packet_type **pt,
1815 1816
					  struct net_device *orig_dev,
					  __be16 type,
1817 1818 1819 1820 1821 1822 1823 1824
					  struct list_head *ptype_list)
{
	struct packet_type *ptype, *pt_prev = *pt;

	list_for_each_entry_rcu(ptype, ptype_list, list) {
		if (ptype->type != type)
			continue;
		if (pt_prev)
1825
			deliver_skb(skb, pt_prev, orig_dev);
1826 1827 1828 1829 1830
		pt_prev = ptype;
	}
	*pt = pt_prev;
}

1831 1832
static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
{
1833
	if (!ptype->af_packet_priv || !skb->sk)
1834 1835 1836 1837 1838 1839 1840 1841 1842 1843
		return false;

	if (ptype->id_match)
		return ptype->id_match(ptype, skb->sk);
	else if ((struct sock *)ptype->af_packet_priv == skb->sk)
		return true;

	return false;
}

L
Linus Torvalds 已提交
1844 1845 1846 1847 1848
/*
 *	Support routine. Sends outgoing frames to any network
 *	taps currently in use.
 */

1849
void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
L
Linus Torvalds 已提交
1850 1851
{
	struct packet_type *ptype;
1852 1853
	struct sk_buff *skb2 = NULL;
	struct packet_type *pt_prev = NULL;
1854
	struct list_head *ptype_list = &ptype_all;
1855

L
Linus Torvalds 已提交
1856
	rcu_read_lock();
1857 1858
again:
	list_for_each_entry_rcu(ptype, ptype_list, list) {
L
Linus Torvalds 已提交
1859 1860 1861
		/* Never send packets back to the socket
		 * they originated from - MvS (miquels@drinkel.ow.org)
		 */
1862 1863
		if (skb_loop_sk(ptype, skb))
			continue;
1864

1865 1866 1867 1868 1869
		if (pt_prev) {
			deliver_skb(skb2, pt_prev, skb->dev);
			pt_prev = ptype;
			continue;
		}
L
Linus Torvalds 已提交
1870

1871 1872 1873 1874
		/* need to clone skb, done only once */
		skb2 = skb_clone(skb, GFP_ATOMIC);
		if (!skb2)
			goto out_unlock;
1875

1876
		net_timestamp_set(skb2);
L
Linus Torvalds 已提交
1877

1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889
		/* skb->nh should be correctly
		 * set by sender, so that the second statement is
		 * just protection against buggy protocols.
		 */
		skb_reset_mac_header(skb2);

		if (skb_network_header(skb2) < skb2->data ||
		    skb_network_header(skb2) > skb_tail_pointer(skb2)) {
			net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
					     ntohs(skb2->protocol),
					     dev->name);
			skb_reset_network_header(skb2);
L
Linus Torvalds 已提交
1890
		}
1891 1892 1893 1894 1895 1896 1897 1898 1899

		skb2->transport_header = skb2->network_header;
		skb2->pkt_type = PACKET_OUTGOING;
		pt_prev = ptype;
	}

	if (ptype_list == &ptype_all) {
		ptype_list = &dev->ptype_all;
		goto again;
L
Linus Torvalds 已提交
1900
	}
1901
out_unlock:
1902 1903
	if (pt_prev)
		pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
L
Linus Torvalds 已提交
1904 1905
	rcu_read_unlock();
}
1906
EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
L
Linus Torvalds 已提交
1907

1908 1909
/**
 * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920
 * @dev: Network device
 * @txq: number of queues available
 *
 * If real_num_tx_queues is changed the tc mappings may no longer be
 * valid. To resolve this verify the tc mapping remains valid and if
 * not NULL the mapping. With no priorities mapping to this
 * offset/count pair it will no longer be used. In the worst case TC0
 * is invalid nothing can be done so disable priority mappings. If is
 * expected that drivers will fix this mapping if they can before
 * calling netif_set_real_num_tx_queues.
 */
E
Eric Dumazet 已提交
1921
static void netif_setup_tc(struct net_device *dev, unsigned int txq)
1922 1923 1924 1925 1926 1927
{
	int i;
	struct netdev_tc_txq *tc = &dev->tc_to_txq[0];

	/* If TC0 is invalidated disable TC mapping */
	if (tc->offset + tc->count > txq) {
1928
		pr_warn("Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
1929 1930 1931 1932 1933 1934 1935 1936 1937 1938
		dev->num_tc = 0;
		return;
	}

	/* Invalidated prio to tc mappings set to TC0 */
	for (i = 1; i < TC_BITMASK + 1; i++) {
		int q = netdev_get_prio_tc_map(dev, i);

		tc = &dev->tc_to_txq[q];
		if (tc->offset + tc->count > txq) {
1939 1940
			pr_warn("Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n",
				i, q);
1941 1942 1943 1944 1945
			netdev_set_prio_tc_map(dev, i, 0);
		}
	}
}

1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962
int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
{
	if (dev->num_tc) {
		struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
		int i;

		for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
			if ((txq - tc->offset) < tc->count)
				return i;
		}

		return -1;
	}

	return 0;
}

1963 1964 1965 1966 1967
#ifdef CONFIG_XPS
static DEFINE_MUTEX(xps_map_mutex);
#define xmap_dereference(P)		\
	rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))

1968 1969
static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
			     int tci, u16 index)
1970
{
1971 1972
	struct xps_map *map = NULL;
	int pos;
1973

1974
	if (dev_maps)
1975 1976 1977
		map = xmap_dereference(dev_maps->cpu_map[tci]);
	if (!map)
		return false;
1978

1979 1980 1981 1982 1983 1984
	for (pos = map->len; pos--;) {
		if (map->queues[pos] != index)
			continue;

		if (map->len > 1) {
			map->queues[pos] = map->queues[--map->len];
1985
			break;
1986
		}
1987 1988 1989 1990

		RCU_INIT_POINTER(dev_maps->cpu_map[tci], NULL);
		kfree_rcu(map, rcu);
		return false;
1991 1992
	}

1993
	return true;
1994 1995
}

1996 1997 1998 1999
static bool remove_xps_queue_cpu(struct net_device *dev,
				 struct xps_dev_maps *dev_maps,
				 int cpu, u16 offset, u16 count)
{
2000 2001 2002
	int num_tc = dev->num_tc ? : 1;
	bool active = false;
	int tci;
2003

2004 2005 2006 2007 2008 2009 2010 2011 2012
	for (tci = cpu * num_tc; num_tc--; tci++) {
		int i, j;

		for (i = count, j = offset; i--; j++) {
			if (!remove_xps_queue(dev_maps, cpu, j))
				break;
		}

		active |= i < 0;
2013 2014
	}

2015
	return active;
2016 2017 2018 2019
}

static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
				   u16 count)
2020 2021
{
	struct xps_dev_maps *dev_maps;
2022
	int cpu, i;
2023 2024 2025 2026 2027 2028 2029 2030
	bool active = false;

	mutex_lock(&xps_map_mutex);
	dev_maps = xmap_dereference(dev->xps_maps);

	if (!dev_maps)
		goto out_no_maps;

2031 2032 2033
	for_each_possible_cpu(cpu)
		active |= remove_xps_queue_cpu(dev, dev_maps, cpu,
					       offset, count);
2034 2035

	if (!active) {
2036 2037 2038 2039
		RCU_INIT_POINTER(dev->xps_maps, NULL);
		kfree_rcu(dev_maps, rcu);
	}

2040
	for (i = offset + (count - 1); count--; i--)
2041 2042 2043
		netdev_queue_numa_node_write(netdev_get_tx_queue(dev, i),
					     NUMA_NO_NODE);

2044 2045 2046 2047
out_no_maps:
	mutex_unlock(&xps_map_mutex);
}

2048 2049 2050 2051 2052
static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
{
	netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
}

2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087
static struct xps_map *expand_xps_map(struct xps_map *map,
				      int cpu, u16 index)
{
	struct xps_map *new_map;
	int alloc_len = XPS_MIN_MAP_ALLOC;
	int i, pos;

	for (pos = 0; map && pos < map->len; pos++) {
		if (map->queues[pos] != index)
			continue;
		return map;
	}

	/* Need to add queue to this CPU's existing map */
	if (map) {
		if (pos < map->alloc_len)
			return map;

		alloc_len = map->alloc_len * 2;
	}

	/* Need to allocate new map to store queue on this CPU's map */
	new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
			       cpu_to_node(cpu));
	if (!new_map)
		return NULL;

	for (i = 0; i < pos; i++)
		new_map->queues[i] = map->queues[i];
	new_map->alloc_len = alloc_len;
	new_map->len = pos;

	return new_map;
}

2088 2089
int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
			u16 index)
2090
{
2091
	struct xps_dev_maps *dev_maps, *new_dev_maps = NULL;
2092 2093
	int i, cpu, tci, numa_node_id = -2;
	int maps_sz, num_tc = 1, tc = 0;
2094
	struct xps_map *map, *new_map;
2095
	bool active = false;
2096

2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107
	if (dev->num_tc) {
		num_tc = dev->num_tc;
		tc = netdev_txq_to_tc(dev, index);
		if (tc < 0)
			return -EINVAL;
	}

	maps_sz = XPS_DEV_MAPS_SIZE(num_tc);
	if (maps_sz < L1_CACHE_BYTES)
		maps_sz = L1_CACHE_BYTES;

2108 2109 2110 2111
	mutex_lock(&xps_map_mutex);

	dev_maps = xmap_dereference(dev->xps_maps);

2112
	/* allocate memory for queue storage */
2113
	for_each_cpu_and(cpu, cpu_online_mask, mask) {
2114 2115
		if (!new_dev_maps)
			new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
2116 2117
		if (!new_dev_maps) {
			mutex_unlock(&xps_map_mutex);
2118
			return -ENOMEM;
2119
		}
2120

2121 2122
		tci = cpu * num_tc + tc;
		map = dev_maps ? xmap_dereference(dev_maps->cpu_map[tci]) :
2123 2124 2125 2126 2127 2128
				 NULL;

		map = expand_xps_map(map, cpu, index);
		if (!map)
			goto error;

2129
		RCU_INIT_POINTER(new_dev_maps->cpu_map[tci], map);
2130 2131 2132 2133 2134
	}

	if (!new_dev_maps)
		goto out_no_new_maps;

2135
	for_each_possible_cpu(cpu) {
2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147
		/* copy maps belonging to foreign traffic classes */
		for (i = tc, tci = cpu * num_tc; dev_maps && i--; tci++) {
			/* fill in the new device map from the old device map */
			map = xmap_dereference(dev_maps->cpu_map[tci]);
			RCU_INIT_POINTER(new_dev_maps->cpu_map[tci], map);
		}

		/* We need to explicitly update tci as prevous loop
		 * could break out early if dev_maps is NULL.
		 */
		tci = cpu * num_tc + tc;

2148 2149 2150 2151
		if (cpumask_test_cpu(cpu, mask) && cpu_online(cpu)) {
			/* add queue to CPU maps */
			int pos = 0;

2152
			map = xmap_dereference(new_dev_maps->cpu_map[tci]);
2153 2154 2155 2156 2157
			while ((pos < map->len) && (map->queues[pos] != index))
				pos++;

			if (pos == map->len)
				map->queues[map->len++] = index;
2158 2159 2160 2161 2162 2163
#ifdef CONFIG_NUMA
			if (numa_node_id == -2)
				numa_node_id = cpu_to_node(cpu);
			else if (numa_node_id != cpu_to_node(cpu))
				numa_node_id = -1;
#endif
2164 2165
		} else if (dev_maps) {
			/* fill in the new device map from the old device map */
2166 2167
			map = xmap_dereference(dev_maps->cpu_map[tci]);
			RCU_INIT_POINTER(new_dev_maps->cpu_map[tci], map);
2168
		}
2169

2170 2171 2172 2173 2174 2175
		/* copy maps belonging to foreign traffic classes */
		for (i = num_tc - tc, tci++; dev_maps && --i; tci++) {
			/* fill in the new device map from the old device map */
			map = xmap_dereference(dev_maps->cpu_map[tci]);
			RCU_INIT_POINTER(new_dev_maps->cpu_map[tci], map);
		}
2176 2177
	}

2178 2179
	rcu_assign_pointer(dev->xps_maps, new_dev_maps);

2180
	/* Cleanup old maps */
2181 2182 2183 2184 2185 2186 2187
	if (!dev_maps)
		goto out_no_old_maps;

	for_each_possible_cpu(cpu) {
		for (i = num_tc, tci = cpu * num_tc; i--; tci++) {
			new_map = xmap_dereference(new_dev_maps->cpu_map[tci]);
			map = xmap_dereference(dev_maps->cpu_map[tci]);
2188 2189 2190
			if (map && map != new_map)
				kfree_rcu(map, rcu);
		}
2191 2192
	}

2193 2194 2195
	kfree_rcu(dev_maps, rcu);

out_no_old_maps:
2196 2197
	dev_maps = new_dev_maps;
	active = true;
2198

2199 2200
out_no_new_maps:
	/* update Tx queue numa node */
2201 2202 2203 2204
	netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
				     (numa_node_id >= 0) ? numa_node_id :
				     NUMA_NO_NODE);

2205 2206 2207 2208 2209
	if (!dev_maps)
		goto out_no_maps;

	/* removes queue from unused CPUs */
	for_each_possible_cpu(cpu) {
2210 2211 2212 2213 2214 2215
		for (i = tc, tci = cpu * num_tc; i--; tci++)
			active |= remove_xps_queue(dev_maps, tci, index);
		if (!cpumask_test_cpu(cpu, mask) || !cpu_online(cpu))
			active |= remove_xps_queue(dev_maps, tci, index);
		for (i = num_tc - tc, tci++; --i; tci++)
			active |= remove_xps_queue(dev_maps, tci, index);
2216 2217 2218 2219 2220 2221 2222 2223 2224
	}

	/* free map if not active */
	if (!active) {
		RCU_INIT_POINTER(dev->xps_maps, NULL);
		kfree_rcu(dev_maps, rcu);
	}

out_no_maps:
2225 2226 2227 2228
	mutex_unlock(&xps_map_mutex);

	return 0;
error:
2229 2230
	/* remove any maps that we added */
	for_each_possible_cpu(cpu) {
2231 2232 2233 2234 2235 2236 2237 2238
		for (i = num_tc, tci = cpu * num_tc; i--; tci++) {
			new_map = xmap_dereference(new_dev_maps->cpu_map[tci]);
			map = dev_maps ?
			      xmap_dereference(dev_maps->cpu_map[tci]) :
			      NULL;
			if (new_map && new_map != map)
				kfree(new_map);
		}
2239 2240
	}

2241 2242 2243 2244 2245 2246 2247 2248
	mutex_unlock(&xps_map_mutex);

	kfree(new_dev_maps);
	return -ENOMEM;
}
EXPORT_SYMBOL(netif_set_xps_queue);

#endif
2249 2250
void netdev_reset_tc(struct net_device *dev)
{
2251 2252 2253
#ifdef CONFIG_XPS
	netif_reset_xps_queues_gt(dev, 0);
#endif
2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264
	dev->num_tc = 0;
	memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
	memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
}
EXPORT_SYMBOL(netdev_reset_tc);

int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
{
	if (tc >= dev->num_tc)
		return -EINVAL;

2265 2266 2267
#ifdef CONFIG_XPS
	netif_reset_xps_queues(dev, offset, count);
#endif
2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278
	dev->tc_to_txq[tc].count = count;
	dev->tc_to_txq[tc].offset = offset;
	return 0;
}
EXPORT_SYMBOL(netdev_set_tc_queue);

int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
{
	if (num_tc > TC_MAX_QUEUE)
		return -EINVAL;

2279 2280 2281
#ifdef CONFIG_XPS
	netif_reset_xps_queues_gt(dev, 0);
#endif
2282 2283 2284 2285 2286
	dev->num_tc = num_tc;
	return 0;
}
EXPORT_SYMBOL(netdev_set_num_tc);

2287 2288 2289 2290
/*
 * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
 * greater then real_num_tx_queues stale skbs on the qdisc must be flushed.
 */
2291
int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2292
{
T
Tom Herbert 已提交
2293 2294
	int rc;

2295 2296
	if (txq < 1 || txq > dev->num_tx_queues)
		return -EINVAL;
2297

2298 2299
	if (dev->reg_state == NETREG_REGISTERED ||
	    dev->reg_state == NETREG_UNREGISTERING) {
2300 2301
		ASSERT_RTNL();

T
Tom Herbert 已提交
2302 2303
		rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
						  txq);
T
Tom Herbert 已提交
2304 2305 2306
		if (rc)
			return rc;

2307 2308 2309
		if (dev->num_tc)
			netif_setup_tc(dev, txq);

2310
		if (txq < dev->real_num_tx_queues) {
2311
			qdisc_reset_all_tx_gt(dev, txq);
2312 2313 2314 2315
#ifdef CONFIG_XPS
			netif_reset_xps_queues_gt(dev, txq);
#endif
		}
2316
	}
2317 2318 2319

	dev->real_num_tx_queues = txq;
	return 0;
2320 2321
}
EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2322

2323
#ifdef CONFIG_SYSFS
2324 2325 2326 2327 2328 2329 2330
/**
 *	netif_set_real_num_rx_queues - set actual number of RX queues used
 *	@dev: Network device
 *	@rxq: Actual number of RX queues
 *
 *	This must be called either with the rtnl_lock held or before
 *	registration of the net device.  Returns 0 on success, or a
2331 2332
 *	negative error code.  If called before registration, it always
 *	succeeds.
2333 2334 2335 2336 2337
 */
int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
{
	int rc;

T
Tom Herbert 已提交
2338 2339 2340
	if (rxq < 1 || rxq > dev->num_rx_queues)
		return -EINVAL;

2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355
	if (dev->reg_state == NETREG_REGISTERED) {
		ASSERT_RTNL();

		rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
						  rxq);
		if (rc)
			return rc;
	}

	dev->real_num_rx_queues = rxq;
	return 0;
}
EXPORT_SYMBOL(netif_set_real_num_rx_queues);
#endif

2356 2357
/**
 * netif_get_num_default_rss_queues - default number of RSS queues
2358 2359 2360 2361
 *
 * This routine should set an upper limit on the number of RSS queues
 * used by default by multiqueue devices.
 */
2362
int netif_get_num_default_rss_queues(void)
2363
{
2364 2365
	return is_kdump_kernel() ?
		1 : min_t(int, DEFAULT_MAX_NUM_RSS_QUEUES, num_online_cpus());
2366 2367 2368
}
EXPORT_SYMBOL(netif_get_num_default_rss_queues);

2369
static void __netif_reschedule(struct Qdisc *q)
2370
{
2371 2372
	struct softnet_data *sd;
	unsigned long flags;
2373

2374
	local_irq_save(flags);
2375
	sd = this_cpu_ptr(&softnet_data);
2376 2377 2378
	q->next_sched = NULL;
	*sd->output_queue_tailp = q;
	sd->output_queue_tailp = &q->next_sched;
2379 2380 2381 2382 2383 2384 2385 2386
	raise_softirq_irqoff(NET_TX_SOFTIRQ);
	local_irq_restore(flags);
}

void __netif_schedule(struct Qdisc *q)
{
	if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
		__netif_reschedule(q);
2387 2388 2389
}
EXPORT_SYMBOL(__netif_schedule);

2390 2391 2392 2393 2394
struct dev_kfree_skb_cb {
	enum skb_free_reason reason;
};

static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
2395
{
2396 2397 2398
	return (struct dev_kfree_skb_cb *)skb->cb;
}

2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445
void netif_schedule_queue(struct netdev_queue *txq)
{
	rcu_read_lock();
	if (!(txq->state & QUEUE_STATE_ANY_XOFF)) {
		struct Qdisc *q = rcu_dereference(txq->qdisc);

		__netif_schedule(q);
	}
	rcu_read_unlock();
}
EXPORT_SYMBOL(netif_schedule_queue);

/**
 *	netif_wake_subqueue - allow sending packets on subqueue
 *	@dev: network device
 *	@queue_index: sub queue index
 *
 * Resume individual transmit queue of a device with multiple transmit queues.
 */
void netif_wake_subqueue(struct net_device *dev, u16 queue_index)
{
	struct netdev_queue *txq = netdev_get_tx_queue(dev, queue_index);

	if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &txq->state)) {
		struct Qdisc *q;

		rcu_read_lock();
		q = rcu_dereference(txq->qdisc);
		__netif_schedule(q);
		rcu_read_unlock();
	}
}
EXPORT_SYMBOL(netif_wake_subqueue);

void netif_tx_wake_queue(struct netdev_queue *dev_queue)
{
	if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
		struct Qdisc *q;

		rcu_read_lock();
		q = rcu_dereference(dev_queue->qdisc);
		__netif_schedule(q);
		rcu_read_unlock();
	}
}
EXPORT_SYMBOL(netif_tx_wake_queue);

2446
void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason)
2447
{
2448
	unsigned long flags;
2449

2450 2451 2452 2453 2454
	if (likely(atomic_read(&skb->users) == 1)) {
		smp_rmb();
		atomic_set(&skb->users, 0);
	} else if (likely(!atomic_dec_and_test(&skb->users))) {
		return;
2455
	}
2456 2457 2458 2459 2460 2461
	get_kfree_skb_cb(skb)->reason = reason;
	local_irq_save(flags);
	skb->next = __this_cpu_read(softnet_data.completion_queue);
	__this_cpu_write(softnet_data.completion_queue, skb);
	raise_softirq_irqoff(NET_TX_SOFTIRQ);
	local_irq_restore(flags);
2462
}
2463
EXPORT_SYMBOL(__dev_kfree_skb_irq);
2464

2465
void __dev_kfree_skb_any(struct sk_buff *skb, enum skb_free_reason reason)
2466 2467
{
	if (in_irq() || irqs_disabled())
2468
		__dev_kfree_skb_irq(skb, reason);
2469 2470 2471
	else
		dev_kfree_skb(skb);
}
2472
EXPORT_SYMBOL(__dev_kfree_skb_any);
2473 2474


2475 2476 2477 2478 2479 2480
/**
 * netif_device_detach - mark device as removed
 * @dev: network device
 *
 * Mark device as removed from system and therefore no longer available.
 */
2481 2482 2483 2484
void netif_device_detach(struct net_device *dev)
{
	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
	    netif_running(dev)) {
2485
		netif_tx_stop_all_queues(dev);
2486 2487 2488 2489
	}
}
EXPORT_SYMBOL(netif_device_detach);

2490 2491 2492 2493 2494 2495
/**
 * netif_device_attach - mark device as attached
 * @dev: network device
 *
 * Mark device as attached from system and restart if needed.
 */
2496 2497 2498 2499
void netif_device_attach(struct net_device *dev)
{
	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
	    netif_running(dev)) {
2500
		netif_tx_wake_all_queues(dev);
2501
		__netdev_watchdog_up(dev);
2502 2503 2504 2505
	}
}
EXPORT_SYMBOL(netif_device_attach);

J
Jiri Pirko 已提交
2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533
/*
 * Returns a Tx hash based on the given packet descriptor a Tx queues' number
 * to be used as a distribution range.
 */
u16 __skb_tx_hash(const struct net_device *dev, struct sk_buff *skb,
		  unsigned int num_tx_queues)
{
	u32 hash;
	u16 qoffset = 0;
	u16 qcount = num_tx_queues;

	if (skb_rx_queue_recorded(skb)) {
		hash = skb_get_rx_queue(skb);
		while (unlikely(hash >= num_tx_queues))
			hash -= num_tx_queues;
		return hash;
	}

	if (dev->num_tc) {
		u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
		qoffset = dev->tc_to_txq[tc].offset;
		qcount = dev->tc_to_txq[tc].count;
	}

	return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
}
EXPORT_SYMBOL(__skb_tx_hash);

2534 2535
static void skb_warn_bad_offload(const struct sk_buff *skb)
{
W
Wei Tang 已提交
2536
	static const netdev_features_t null_features;
2537
	struct net_device *dev = skb->dev;
2538
	const char *name = "";
2539

2540 2541 2542
	if (!net_ratelimit())
		return;

2543 2544 2545 2546 2547 2548
	if (dev) {
		if (dev->dev.parent)
			name = dev_driver_string(dev->dev.parent);
		else
			name = netdev_name(dev);
	}
2549 2550
	WARN(1, "%s: caps=(%pNF, %pNF) len=%d data_len=%d gso_size=%d "
	     "gso_type=%d ip_summed=%d\n",
2551
	     name, dev ? &dev->features : &null_features,
2552
	     skb->sk ? &skb->sk->sk_route_caps : &null_features,
2553 2554 2555 2556
	     skb->len, skb->data_len, skb_shinfo(skb)->gso_size,
	     skb_shinfo(skb)->gso_type, skb->ip_summed);
}

L
Linus Torvalds 已提交
2557 2558 2559 2560
/*
 * Invalidate hardware checksum when packet is to be mangled, and
 * complete checksum manually on outgoing path.
 */
2561
int skb_checksum_help(struct sk_buff *skb)
L
Linus Torvalds 已提交
2562
{
2563
	__wsum csum;
2564
	int ret = 0, offset;
L
Linus Torvalds 已提交
2565

2566
	if (skb->ip_summed == CHECKSUM_COMPLETE)
2567 2568 2569
		goto out_set_summed;

	if (unlikely(skb_shinfo(skb)->gso_size)) {
2570 2571
		skb_warn_bad_offload(skb);
		return -EINVAL;
L
Linus Torvalds 已提交
2572 2573
	}

2574 2575 2576 2577 2578 2579 2580 2581 2582
	/* Before computing a checksum, we should make sure no frag could
	 * be modified by an external entity : checksum could be wrong.
	 */
	if (skb_has_shared_frag(skb)) {
		ret = __skb_linearize(skb);
		if (ret)
			goto out;
	}

2583
	offset = skb_checksum_start_offset(skb);
2584 2585 2586 2587 2588 2589 2590 2591
	BUG_ON(offset >= skb_headlen(skb));
	csum = skb_checksum(skb, offset, skb->len - offset, 0);

	offset += skb->csum_offset;
	BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));

	if (skb_cloned(skb) &&
	    !skb_clone_writable(skb, offset + sizeof(__sum16))) {
L
Linus Torvalds 已提交
2592 2593 2594 2595 2596
		ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
		if (ret)
			goto out;
	}

2597
	*(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
2598
out_set_summed:
L
Linus Torvalds 已提交
2599
	skb->ip_summed = CHECKSUM_NONE;
2600
out:
L
Linus Torvalds 已提交
2601 2602
	return ret;
}
E
Eric Dumazet 已提交
2603
EXPORT_SYMBOL(skb_checksum_help);
L
Linus Torvalds 已提交
2604

2605
__be16 skb_network_protocol(struct sk_buff *skb, int *depth)
2606
{
A
Al Viro 已提交
2607
	__be16 type = skb->protocol;
2608

2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619
	/* Tunnel gso handlers can set protocol to ethernet. */
	if (type == htons(ETH_P_TEB)) {
		struct ethhdr *eth;

		if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
			return 0;

		eth = (struct ethhdr *)skb_mac_header(skb);
		type = eth->h_proto;
	}

2620
	return __vlan_get_protocol(skb, type, depth);
2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632
}

/**
 *	skb_mac_gso_segment - mac layer segmentation handler.
 *	@skb: buffer to segment
 *	@features: features for the output path (see dev->features)
 */
struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb,
				    netdev_features_t features)
{
	struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
	struct packet_offload *ptype;
2633 2634
	int vlan_depth = skb->mac_len;
	__be16 type = skb_network_protocol(skb, &vlan_depth);
2635 2636 2637 2638

	if (unlikely(!type))
		return ERR_PTR(-EINVAL);

2639
	__skb_pull(skb, vlan_depth);
2640 2641

	rcu_read_lock();
2642
	list_for_each_entry_rcu(ptype, &offload_base, list) {
2643 2644
		if (ptype->type == type && ptype->callbacks.gso_segment) {
			segs = ptype->callbacks.gso_segment(skb, features);
2645 2646 2647 2648 2649
			break;
		}
	}
	rcu_read_unlock();

2650
	__skb_push(skb, skb->data - skb_mac_header(skb));
2651

2652 2653
	return segs;
}
2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676
EXPORT_SYMBOL(skb_mac_gso_segment);


/* openvswitch calls this on rx path, so we need a different check.
 */
static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
{
	if (tx_path)
		return skb->ip_summed != CHECKSUM_PARTIAL;
	else
		return skb->ip_summed == CHECKSUM_NONE;
}

/**
 *	__skb_gso_segment - Perform segmentation on skb.
 *	@skb: buffer to segment
 *	@features: features for the output path (see dev->features)
 *	@tx_path: whether it is called in TX path
 *
 *	This function segments the given skb and returns a list of segments.
 *
 *	It may return NULL if the skb requires no segmentation.  This is
 *	only possible when GSO is used for verifying header integrity.
2677 2678
 *
 *	Segmentation preserves SKB_SGO_CB_OFFSET bytes of previous skb cb.
2679 2680 2681 2682 2683 2684 2685 2686 2687
 */
struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
				  netdev_features_t features, bool tx_path)
{
	if (unlikely(skb_needs_check(skb, tx_path))) {
		int err;

		skb_warn_bad_offload(skb);

2688 2689
		err = skb_cow_head(skb, 0);
		if (err < 0)
2690 2691 2692
			return ERR_PTR(err);
	}

2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705
	/* Only report GSO partial support if it will enable us to
	 * support segmentation on this frame without needing additional
	 * work.
	 */
	if (features & NETIF_F_GSO_PARTIAL) {
		netdev_features_t partial_features = NETIF_F_GSO_ROBUST;
		struct net_device *dev = skb->dev;

		partial_features |= dev->features & dev->gso_partial_features;
		if (!skb_gso_ok(skb, features | partial_features))
			features &= ~NETIF_F_GSO_PARTIAL;
	}

2706 2707 2708
	BUILD_BUG_ON(SKB_SGO_CB_OFFSET +
		     sizeof(*SKB_GSO_CB(skb)) > sizeof(skb->cb));

2709
	SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
2710 2711
	SKB_GSO_CB(skb)->encap_level = 0;

2712 2713 2714 2715 2716
	skb_reset_mac_header(skb);
	skb_reset_mac_len(skb);

	return skb_mac_gso_segment(skb, features);
}
2717
EXPORT_SYMBOL(__skb_gso_segment);
2718

2719 2720 2721 2722 2723
/* Take action when hardware reception checksum errors are detected. */
#ifdef CONFIG_BUG
void netdev_rx_csum_fault(struct net_device *dev)
{
	if (net_ratelimit()) {
2724
		pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
2725 2726 2727 2728 2729 2730
		dump_stack();
	}
}
EXPORT_SYMBOL(netdev_rx_csum_fault);
#endif

L
Linus Torvalds 已提交
2731 2732 2733 2734 2735
/* Actually, we should eliminate this check as soon as we know, that:
 * 1. IOMMU is present and allows to map all the memory.
 * 2. No high memory really exists on this machine.
 */

2736
static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
L
Linus Torvalds 已提交
2737
{
2738
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2739
	int i;
2740
	if (!(dev->features & NETIF_F_HIGHDMA)) {
2741 2742 2743
		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
			if (PageHighMem(skb_frag_page(frag)))
2744
				return 1;
2745
		}
2746
	}
L
Linus Torvalds 已提交
2747

2748 2749
	if (PCI_DMA_BUS_IS_PHYS) {
		struct device *pdev = dev->dev.parent;
L
Linus Torvalds 已提交
2750

E
Eric Dumazet 已提交
2751 2752
		if (!pdev)
			return 0;
2753
		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
2754 2755
			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
			dma_addr_t addr = page_to_phys(skb_frag_page(frag));
2756 2757 2758 2759
			if (!pdev->dma_mask || addr + PAGE_SIZE - 1 > *pdev->dma_mask)
				return 1;
		}
	}
2760
#endif
L
Linus Torvalds 已提交
2761 2762 2763
	return 0;
}

2764 2765 2766
/* If MPLS offload request, verify we are testing hardware MPLS features
 * instead of standard features for the netdev.
 */
P
Pravin B Shelar 已提交
2767
#if IS_ENABLED(CONFIG_NET_MPLS_GSO)
2768 2769 2770 2771
static netdev_features_t net_mpls_features(struct sk_buff *skb,
					   netdev_features_t features,
					   __be16 type)
{
2772
	if (eth_p_mpls(type))
2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785
		features &= skb->dev->mpls_features;

	return features;
}
#else
static netdev_features_t net_mpls_features(struct sk_buff *skb,
					   netdev_features_t features,
					   __be16 type)
{
	return features;
}
#endif

2786
static netdev_features_t harmonize_features(struct sk_buff *skb,
2787
	netdev_features_t features)
2788
{
2789
	int tmp;
2790 2791 2792 2793
	__be16 type;

	type = skb_network_protocol(skb, &tmp);
	features = net_mpls_features(skb, features, type);
2794

2795
	if (skb->ip_summed != CHECKSUM_NONE &&
2796
	    !can_checksum_protocol(features, type)) {
2797
		features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
2798
	} else if (illegal_highdma(skb->dev, skb)) {
2799 2800 2801 2802 2803 2804
		features &= ~NETIF_F_SG;
	}

	return features;
}

2805 2806 2807 2808 2809 2810 2811 2812
netdev_features_t passthru_features_check(struct sk_buff *skb,
					  struct net_device *dev,
					  netdev_features_t features)
{
	return features;
}
EXPORT_SYMBOL(passthru_features_check);

2813 2814 2815 2816 2817 2818 2819
static netdev_features_t dflt_features_check(const struct sk_buff *skb,
					     struct net_device *dev,
					     netdev_features_t features)
{
	return vlan_features_check(skb, features);
}

2820 2821 2822 2823 2824 2825 2826 2827 2828
static netdev_features_t gso_features_check(const struct sk_buff *skb,
					    struct net_device *dev,
					    netdev_features_t features)
{
	u16 gso_segs = skb_shinfo(skb)->gso_segs;

	if (gso_segs > dev->gso_max_segs)
		return features & ~NETIF_F_GSO_MASK;

2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839
	/* Support for GSO partial features requires software
	 * intervention before we can actually process the packets
	 * so we need to strip support for any partial features now
	 * and we can pull them back in after we have partially
	 * segmented the frame.
	 */
	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
		features &= ~dev->gso_partial_features;

	/* Make sure to clear the IPv4 ID mangling feature if the
	 * IPv4 header has the potential to be fragmented.
2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851
	 */
	if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
		struct iphdr *iph = skb->encapsulation ?
				    inner_ip_hdr(skb) : ip_hdr(skb);

		if (!(iph->frag_off & htons(IP_DF)))
			features &= ~NETIF_F_TSO_MANGLEID;
	}

	return features;
}

2852
netdev_features_t netif_skb_features(struct sk_buff *skb)
2853
{
2854
	struct net_device *dev = skb->dev;
2855
	netdev_features_t features = dev->features;
2856

2857 2858
	if (skb_is_gso(skb))
		features = gso_features_check(skb, dev, features);
2859

2860 2861 2862 2863 2864 2865 2866
	/* If encapsulation offload request, verify we are testing
	 * hardware encapsulation features instead of standard
	 * features for the netdev
	 */
	if (skb->encapsulation)
		features &= dev->hw_enc_features;

2867 2868 2869 2870 2871
	if (skb_vlan_tagged(skb))
		features = netdev_intersect_features(features,
						     dev->vlan_features |
						     NETIF_F_HW_VLAN_CTAG_TX |
						     NETIF_F_HW_VLAN_STAG_TX);
2872

2873 2874 2875
	if (dev->netdev_ops->ndo_features_check)
		features &= dev->netdev_ops->ndo_features_check(skb, dev,
								features);
2876 2877
	else
		features &= dflt_features_check(skb, dev, features);
2878

2879
	return harmonize_features(skb, features);
2880
}
2881
EXPORT_SYMBOL(netif_skb_features);
2882

2883
static int xmit_one(struct sk_buff *skb, struct net_device *dev,
2884
		    struct netdev_queue *txq, bool more)
2885
{
2886 2887
	unsigned int len;
	int rc;
2888

2889
	if (!list_empty(&ptype_all) || !list_empty(&dev->ptype_all))
2890
		dev_queue_xmit_nit(skb, dev);
2891

2892 2893
	len = skb->len;
	trace_net_dev_start_xmit(skb, dev);
2894
	rc = netdev_start_xmit(skb, dev, txq, more);
2895
	trace_net_dev_xmit(skb, rc, dev, len);
E
Eric Dumazet 已提交
2896

2897 2898
	return rc;
}
2899

2900 2901
struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
				    struct netdev_queue *txq, int *ret)
2902 2903 2904
{
	struct sk_buff *skb = first;
	int rc = NETDEV_TX_OK;
2905

2906 2907
	while (skb) {
		struct sk_buff *next = skb->next;
2908

2909
		skb->next = NULL;
2910
		rc = xmit_one(skb, dev, txq, next != NULL);
2911 2912 2913 2914
		if (unlikely(!dev_xmit_complete(rc))) {
			skb->next = next;
			goto out;
		}
2915

2916 2917 2918 2919
		skb = next;
		if (netif_xmit_stopped(txq) && skb) {
			rc = NETDEV_TX_BUSY;
			break;
2920
		}
2921
	}
2922

2923 2924 2925 2926
out:
	*ret = rc;
	return skb;
}
2927

E
Eric Dumazet 已提交
2928 2929
static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
					  netdev_features_t features)
2930
{
2931
	if (skb_vlan_tag_present(skb) &&
2932 2933
	    !vlan_hw_offload_capable(features, skb->vlan_proto))
		skb = __vlan_hwaccel_push_inside(skb);
2934 2935
	return skb;
}
2936

2937
static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev)
2938 2939
{
	netdev_features_t features;
2940

2941 2942 2943 2944
	features = netif_skb_features(skb);
	skb = validate_xmit_vlan(skb, features);
	if (unlikely(!skb))
		goto out_null;
2945

2946
	if (netif_needs_gso(skb, features)) {
2947 2948 2949
		struct sk_buff *segs;

		segs = skb_gso_segment(skb, features);
2950
		if (IS_ERR(segs)) {
2951
			goto out_kfree_skb;
2952 2953 2954
		} else if (segs) {
			consume_skb(skb);
			skb = segs;
2955
		}
2956 2957 2958 2959
	} else {
		if (skb_needs_linearize(skb, features) &&
		    __skb_linearize(skb))
			goto out_kfree_skb;
2960

2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971
		/* If packet is not checksummed and device does not
		 * support checksumming for this protocol, complete
		 * checksumming here.
		 */
		if (skb->ip_summed == CHECKSUM_PARTIAL) {
			if (skb->encapsulation)
				skb_set_inner_transport_header(skb,
							       skb_checksum_start_offset(skb));
			else
				skb_set_transport_header(skb,
							 skb_checksum_start_offset(skb));
2972
			if (!(features & NETIF_F_CSUM_MASK) &&
2973 2974
			    skb_checksum_help(skb))
				goto out_kfree_skb;
2975
		}
2976
	}
2977

2978
	return skb;
2979

2980 2981
out_kfree_skb:
	kfree_skb(skb);
2982
out_null:
E
Eric Dumazet 已提交
2983
	atomic_long_inc(&dev->tx_dropped);
2984 2985
	return NULL;
}
2986

2987 2988 2989 2990
struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev)
{
	struct sk_buff *next, *head = NULL, *tail;

2991
	for (; skb != NULL; skb = next) {
2992 2993
		next = skb->next;
		skb->next = NULL;
2994 2995 2996 2997

		/* in case skb wont be segmented, point to itself */
		skb->prev = skb;

2998
		skb = validate_xmit_skb(skb, dev);
2999 3000
		if (!skb)
			continue;
3001

3002 3003 3004 3005 3006 3007 3008 3009
		if (!head)
			head = skb;
		else
			tail->next = skb;
		/* If skb was segmented, skb->prev points to
		 * the last segment. If not, it still contains skb.
		 */
		tail = skb->prev;
3010 3011
	}
	return head;
3012
}
3013
EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
3014

3015 3016 3017 3018 3019 3020 3021 3022 3023 3024
static void qdisc_pkt_len_init(struct sk_buff *skb)
{
	const struct skb_shared_info *shinfo = skb_shinfo(skb);

	qdisc_skb_cb(skb)->pkt_len = skb->len;

	/* To get more precise estimation of bytes sent on wire,
	 * we add to pkt_len the headers size of all segments
	 */
	if (shinfo->gso_size)  {
3025
		unsigned int hdr_len;
3026
		u16 gso_segs = shinfo->gso_segs;
3027

3028 3029 3030 3031
		/* mac layer + network layer */
		hdr_len = skb_transport_header(skb) - skb_mac_header(skb);

		/* + transport layer */
3032 3033 3034 3035
		if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
			hdr_len += tcp_hdrlen(skb);
		else
			hdr_len += sizeof(struct udphdr);
3036 3037 3038 3039 3040 3041

		if (shinfo->gso_type & SKB_GSO_DODGY)
			gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
						shinfo->gso_size);

		qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
3042 3043 3044
	}
}

3045 3046 3047 3048 3049
static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
				 struct net_device *dev,
				 struct netdev_queue *txq)
{
	spinlock_t *root_lock = qdisc_lock(q);
3050
	struct sk_buff *to_free = NULL;
E
Eric Dumazet 已提交
3051
	bool contended;
3052 3053
	int rc;

E
Eric Dumazet 已提交
3054
	qdisc_calculate_pkt_len(skb, q);
3055 3056 3057
	/*
	 * Heuristic to force contended enqueues to serialize on a
	 * separate lock before trying to get qdisc main lock.
3058
	 * This permits qdisc->running owner to get the lock more
Y
Ying Xue 已提交
3059
	 * often and dequeue packets faster.
3060
	 */
E
Eric Dumazet 已提交
3061
	contended = qdisc_is_running(q);
3062 3063 3064
	if (unlikely(contended))
		spin_lock(&q->busylock);

3065 3066
	spin_lock(root_lock);
	if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
3067
		__qdisc_drop(skb, &to_free);
3068 3069
		rc = NET_XMIT_DROP;
	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
3070
		   qdisc_run_begin(q)) {
3071 3072 3073 3074 3075
		/*
		 * This is a work-conserving queue; there are no old skbs
		 * waiting to be sent out; and the qdisc is not running -
		 * xmit the skb directly.
		 */
3076 3077 3078

		qdisc_bstats_update(q, skb);

3079
		if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
3080 3081 3082 3083
			if (unlikely(contended)) {
				spin_unlock(&q->busylock);
				contended = false;
			}
3084
			__qdisc_run(q);
3085
		} else
3086
			qdisc_run_end(q);
3087 3088 3089

		rc = NET_XMIT_SUCCESS;
	} else {
3090
		rc = q->enqueue(skb, q, &to_free) & NET_XMIT_MASK;
3091 3092 3093 3094 3095 3096 3097
		if (qdisc_run_begin(q)) {
			if (unlikely(contended)) {
				spin_unlock(&q->busylock);
				contended = false;
			}
			__qdisc_run(q);
		}
3098 3099
	}
	spin_unlock(root_lock);
3100 3101
	if (unlikely(to_free))
		kfree_skb_list(to_free);
3102 3103
	if (unlikely(contended))
		spin_unlock(&q->busylock);
3104 3105 3106
	return rc;
}

3107
#if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
3108 3109
static void skb_update_prio(struct sk_buff *skb)
{
I
Igor Maravic 已提交
3110
	struct netprio_map *map = rcu_dereference_bh(skb->dev->priomap);
3111

3112
	if (!skb->priority && skb->sk && map) {
3113 3114
		unsigned int prioidx =
			sock_cgroup_prioidx(&skb->sk->sk_cgrp_data);
3115 3116 3117 3118

		if (prioidx < map->priomap_len)
			skb->priority = map->priomap[prioidx];
	}
3119 3120 3121 3122 3123
}
#else
#define skb_update_prio(skb)
#endif

3124 3125 3126
DEFINE_PER_CPU(int, xmit_recursion);
EXPORT_SYMBOL(xmit_recursion);

3127 3128
/**
 *	dev_loopback_xmit - loop back @skb
3129 3130
 *	@net: network namespace this loopback is happening in
 *	@sk:  sk needed to be a netfilter okfn
3131 3132
 *	@skb: buffer to transmit
 */
3133
int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145
{
	skb_reset_mac_header(skb);
	__skb_pull(skb, skb_network_offset(skb));
	skb->pkt_type = PACKET_LOOPBACK;
	skb->ip_summed = CHECKSUM_UNNECESSARY;
	WARN_ON(!skb_dst(skb));
	skb_dst_force(skb);
	netif_rx_ni(skb);
	return 0;
}
EXPORT_SYMBOL(dev_loopback_xmit);

D
Daniel Borkmann 已提交
3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168
#ifdef CONFIG_NET_EGRESS
static struct sk_buff *
sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
{
	struct tcf_proto *cl = rcu_dereference_bh(dev->egress_cl_list);
	struct tcf_result cl_res;

	if (!cl)
		return skb;

	/* skb->tc_verd and qdisc_skb_cb(skb)->pkt_len were already set
	 * earlier by the caller.
	 */
	qdisc_bstats_cpu_update(cl->q, skb);

	switch (tc_classify(skb, cl, &cl_res, false)) {
	case TC_ACT_OK:
	case TC_ACT_RECLASSIFY:
		skb->tc_index = TC_H_MIN(cl_res.classid);
		break;
	case TC_ACT_SHOT:
		qdisc_qstats_cpu_drop(cl->q);
		*ret = NET_XMIT_DROP;
3169 3170
		kfree_skb(skb);
		return NULL;
D
Daniel Borkmann 已提交
3171 3172 3173
	case TC_ACT_STOLEN:
	case TC_ACT_QUEUED:
		*ret = NET_XMIT_SUCCESS;
3174
		consume_skb(skb);
D
Daniel Borkmann 已提交
3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188
		return NULL;
	case TC_ACT_REDIRECT:
		/* No need to push/pop skb's mac_header here on egress! */
		skb_do_redirect(skb);
		*ret = NET_XMIT_SUCCESS;
		return NULL;
	default:
		break;
	}

	return skb;
}
#endif /* CONFIG_NET_EGRESS */

3189 3190 3191 3192 3193 3194 3195 3196 3197 3198
static inline int get_xps_queue(struct net_device *dev, struct sk_buff *skb)
{
#ifdef CONFIG_XPS
	struct xps_dev_maps *dev_maps;
	struct xps_map *map;
	int queue_index = -1;

	rcu_read_lock();
	dev_maps = rcu_dereference(dev->xps_maps);
	if (dev_maps) {
3199 3200 3201 3202 3203 3204 3205 3206
		unsigned int tci = skb->sender_cpu - 1;

		if (dev->num_tc) {
			tci *= dev->num_tc;
			tci += netdev_get_prio_tc_map(dev, skb->priority);
		}

		map = rcu_dereference(dev_maps->cpu_map[tci]);
3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236
		if (map) {
			if (map->len == 1)
				queue_index = map->queues[0];
			else
				queue_index = map->queues[reciprocal_scale(skb_get_hash(skb),
									   map->len)];
			if (unlikely(queue_index >= dev->real_num_tx_queues))
				queue_index = -1;
		}
	}
	rcu_read_unlock();

	return queue_index;
#else
	return -1;
#endif
}

static u16 __netdev_pick_tx(struct net_device *dev, struct sk_buff *skb)
{
	struct sock *sk = skb->sk;
	int queue_index = sk_tx_queue_get(sk);

	if (queue_index < 0 || skb->ooo_okay ||
	    queue_index >= dev->real_num_tx_queues) {
		int new_index = get_xps_queue(dev, skb);
		if (new_index < 0)
			new_index = skb_tx_hash(dev, skb);

		if (queue_index != new_index && sk &&
3237
		    sk_fullsock(sk) &&
3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253
		    rcu_access_pointer(sk->sk_dst_cache))
			sk_tx_queue_set(sk, new_index);

		queue_index = new_index;
	}

	return queue_index;
}

struct netdev_queue *netdev_pick_tx(struct net_device *dev,
				    struct sk_buff *skb,
				    void *accel_priv)
{
	int queue_index = 0;

#ifdef CONFIG_XPS
3254 3255 3256
	u32 sender_cpu = skb->sender_cpu - 1;

	if (sender_cpu >= (u32)NR_CPUS)
3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275
		skb->sender_cpu = raw_smp_processor_id() + 1;
#endif

	if (dev->real_num_tx_queues != 1) {
		const struct net_device_ops *ops = dev->netdev_ops;
		if (ops->ndo_select_queue)
			queue_index = ops->ndo_select_queue(dev, skb, accel_priv,
							    __netdev_pick_tx);
		else
			queue_index = __netdev_pick_tx(dev, skb);

		if (!accel_priv)
			queue_index = netdev_cap_txqueue(dev, queue_index);
	}

	skb_set_queue_mapping(skb, queue_index);
	return netdev_get_tx_queue(dev, queue_index);
}

3276
/**
3277
 *	__dev_queue_xmit - transmit a buffer
3278
 *	@skb: buffer to transmit
3279
 *	@accel_priv: private data used for L2 forwarding offload
3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301
 *
 *	Queue a buffer for transmission to a network device. The caller must
 *	have set the device and priority and built the buffer before calling
 *	this function. The function can be called from an interrupt.
 *
 *	A negative errno code is returned on a failure. A success does not
 *	guarantee the frame will be transmitted as it may be dropped due
 *	to congestion or traffic shaping.
 *
 * -----------------------------------------------------------------------------------
 *      I notice this method can also return errors from the queue disciplines,
 *      including NET_XMIT_DROP, which is a positive value.  So, errors can also
 *      be positive.
 *
 *      Regardless of the return value, the skb is consumed, so it is currently
 *      difficult to retry a send to this method.  (You can bump the ref count
 *      before sending to hold a reference for retry if you are careful.)
 *
 *      When calling this method, interrupts MUST be enabled.  This is because
 *      the BH enable code must have IRQs enabled so that it will not deadlock.
 *          --BLG
 */
3302
static int __dev_queue_xmit(struct sk_buff *skb, void *accel_priv)
L
Linus Torvalds 已提交
3303 3304
{
	struct net_device *dev = skb->dev;
3305
	struct netdev_queue *txq;
L
Linus Torvalds 已提交
3306 3307 3308
	struct Qdisc *q;
	int rc = -ENOMEM;

3309 3310
	skb_reset_mac_header(skb);

3311 3312 3313
	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
		__skb_tstamp_tx(skb, NULL, skb->sk, SCM_TSTAMP_SCHED);

3314 3315
	/* Disable soft irqs for various locks below. Also
	 * stops preemption for RCU.
L
Linus Torvalds 已提交
3316
	 */
3317
	rcu_read_lock_bh();
L
Linus Torvalds 已提交
3318

3319 3320
	skb_update_prio(skb);

D
Daniel Borkmann 已提交
3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331
	qdisc_pkt_len_init(skb);
#ifdef CONFIG_NET_CLS_ACT
	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_EGRESS);
# ifdef CONFIG_NET_EGRESS
	if (static_key_false(&egress_needed)) {
		skb = sch_handle_egress(skb, &rc, dev);
		if (!skb)
			goto out;
	}
# endif
#endif
3332 3333 3334 3335 3336 3337 3338 3339
	/* If device/qdisc don't need skb->dst, release it right now while
	 * its hot in this cpu cache.
	 */
	if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
		skb_dst_drop(skb);
	else
		skb_dst_force(skb);

3340
	txq = netdev_pick_tx(dev, skb, accel_priv);
3341
	q = rcu_dereference_bh(txq->qdisc);
3342

3343
	trace_net_dev_queue(skb);
L
Linus Torvalds 已提交
3344
	if (q->enqueue) {
3345
		rc = __dev_xmit_skb(skb, q, dev, txq);
3346
		goto out;
L
Linus Torvalds 已提交
3347 3348 3349 3350 3351
	}

	/* The device has no queue. Common case for software devices:
	   loopback, all the sorts of tunnels...

H
Herbert Xu 已提交
3352 3353
	   Really, it is unlikely that netif_tx_lock protection is necessary
	   here.  (f.e. loopback and IP tunnels are clean ignoring statistics
L
Linus Torvalds 已提交
3354 3355 3356 3357 3358 3359 3360 3361 3362 3363
	   counters.)
	   However, it is possible, that they rely on protection
	   made by us here.

	   Check this and shot the lock. It is not prone from deadlocks.
	   Either shot noqueue qdisc, it is even simpler 8)
	 */
	if (dev->flags & IFF_UP) {
		int cpu = smp_processor_id(); /* ok because BHs are off */

3364
		if (txq->xmit_lock_owner != cpu) {
3365 3366
			if (unlikely(__this_cpu_read(xmit_recursion) >
				     XMIT_RECURSION_LIMIT))
3367 3368
				goto recursion_alert;

3369 3370
			skb = validate_xmit_skb(skb, dev);
			if (!skb)
E
Eric Dumazet 已提交
3371
				goto out;
3372

3373
			HARD_TX_LOCK(dev, txq, cpu);
L
Linus Torvalds 已提交
3374

3375
			if (!netif_xmit_stopped(txq)) {
3376
				__this_cpu_inc(xmit_recursion);
3377
				skb = dev_hard_start_xmit(skb, dev, txq, &rc);
3378
				__this_cpu_dec(xmit_recursion);
3379
				if (dev_xmit_complete(rc)) {
3380
					HARD_TX_UNLOCK(dev, txq);
L
Linus Torvalds 已提交
3381 3382 3383
					goto out;
				}
			}
3384
			HARD_TX_UNLOCK(dev, txq);
3385 3386
			net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
					     dev->name);
L
Linus Torvalds 已提交
3387 3388
		} else {
			/* Recursion is detected! It is possible,
3389 3390 3391
			 * unfortunately
			 */
recursion_alert:
3392 3393
			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
					     dev->name);
L
Linus Torvalds 已提交
3394 3395 3396 3397
		}
	}

	rc = -ENETDOWN;
3398
	rcu_read_unlock_bh();
L
Linus Torvalds 已提交
3399

3400
	atomic_long_inc(&dev->tx_dropped);
3401
	kfree_skb_list(skb);
L
Linus Torvalds 已提交
3402 3403
	return rc;
out:
3404
	rcu_read_unlock_bh();
L
Linus Torvalds 已提交
3405 3406
	return rc;
}
3407

3408
int dev_queue_xmit(struct sk_buff *skb)
3409 3410 3411
{
	return __dev_queue_xmit(skb, NULL);
}
3412
EXPORT_SYMBOL(dev_queue_xmit);
L
Linus Torvalds 已提交
3413

3414 3415 3416 3417 3418 3419
int dev_queue_xmit_accel(struct sk_buff *skb, void *accel_priv)
{
	return __dev_queue_xmit(skb, accel_priv);
}
EXPORT_SYMBOL(dev_queue_xmit_accel);

L
Linus Torvalds 已提交
3420 3421 3422 3423 3424

/*=======================================================================
			Receiver routines
  =======================================================================*/

3425
int netdev_max_backlog __read_mostly = 1000;
E
Eric Dumazet 已提交
3426 3427
EXPORT_SYMBOL(netdev_max_backlog);

E
Eric Dumazet 已提交
3428
int netdev_tstamp_prequeue __read_mostly = 1;
3429 3430
int netdev_budget __read_mostly = 300;
int weight_p __read_mostly = 64;            /* old backlog weight */
L
Linus Torvalds 已提交
3431

E
Eric Dumazet 已提交
3432 3433 3434 3435 3436 3437 3438 3439
/* Called with irq disabled */
static inline void ____napi_schedule(struct softnet_data *sd,
				     struct napi_struct *napi)
{
	list_add_tail(&napi->poll_list, &sd->poll_list);
	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
}

3440 3441 3442
#ifdef CONFIG_RPS

/* One global table that all flow-based protocols share. */
E
Eric Dumazet 已提交
3443
struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
3444
EXPORT_SYMBOL(rps_sock_flow_table);
3445 3446
u32 rps_cpu_mask __read_mostly;
EXPORT_SYMBOL(rps_cpu_mask);
3447

3448
struct static_key rps_needed __read_mostly;
3449
EXPORT_SYMBOL(rps_needed);
E
Eric Dumazet 已提交
3450 3451
struct static_key rfs_needed __read_mostly;
EXPORT_SYMBOL(rfs_needed);
3452

3453 3454 3455 3456
static struct rps_dev_flow *
set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
	    struct rps_dev_flow *rflow, u16 next_cpu)
{
3457
	if (next_cpu < nr_cpu_ids) {
3458 3459 3460 3461 3462 3463 3464 3465 3466
#ifdef CONFIG_RFS_ACCEL
		struct netdev_rx_queue *rxqueue;
		struct rps_dev_flow_table *flow_table;
		struct rps_dev_flow *old_rflow;
		u32 flow_id;
		u16 rxq_index;
		int rc;

		/* Should we steer this flow to a different hardware queue? */
3467 3468
		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
		    !(dev->features & NETIF_F_NTUPLE))
3469 3470 3471 3472 3473 3474 3475 3476 3477
			goto out;
		rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
		if (rxq_index == skb_get_rx_queue(skb))
			goto out;

		rxqueue = dev->_rx + rxq_index;
		flow_table = rcu_dereference(rxqueue->rps_flow_table);
		if (!flow_table)
			goto out;
3478
		flow_id = skb_get_hash(skb) & flow_table->mask;
3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490
		rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
							rxq_index, flow_id);
		if (rc < 0)
			goto out;
		old_rflow = rflow;
		rflow = &flow_table->flows[flow_id];
		rflow->filter = rc;
		if (old_rflow->filter == rflow->filter)
			old_rflow->filter = RPS_NO_FILTER;
	out:
#endif
		rflow->last_qtail =
3491
			per_cpu(softnet_data, next_cpu).input_queue_head;
3492 3493
	}

3494
	rflow->cpu = next_cpu;
3495 3496 3497
	return rflow;
}

3498 3499 3500 3501 3502 3503 3504 3505
/*
 * get_rps_cpu is called from netif_receive_skb and returns the target
 * CPU from the RPS map of the receiving queue for a given skb.
 * rcu_read_lock must be held on entry.
 */
static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
		       struct rps_dev_flow **rflowp)
{
3506 3507
	const struct rps_sock_flow_table *sock_flow_table;
	struct netdev_rx_queue *rxqueue = dev->_rx;
3508
	struct rps_dev_flow_table *flow_table;
3509
	struct rps_map *map;
3510
	int cpu = -1;
3511
	u32 tcpu;
3512
	u32 hash;
3513 3514 3515

	if (skb_rx_queue_recorded(skb)) {
		u16 index = skb_get_rx_queue(skb);
3516

3517 3518 3519 3520 3521
		if (unlikely(index >= dev->real_num_rx_queues)) {
			WARN_ONCE(dev->real_num_rx_queues > 1,
				  "%s received packet on queue %u, but number "
				  "of RX queues is %u\n",
				  dev->name, index, dev->real_num_rx_queues);
3522 3523
			goto done;
		}
3524 3525
		rxqueue += index;
	}
3526

3527 3528 3529
	/* Avoid computing hash if RFS/RPS is not active for this rxqueue */

	flow_table = rcu_dereference(rxqueue->rps_flow_table);
E
Eric Dumazet 已提交
3530
	map = rcu_dereference(rxqueue->rps_map);
3531
	if (!flow_table && !map)
3532 3533
		goto done;

3534
	skb_reset_network_header(skb);
3535 3536
	hash = skb_get_hash(skb);
	if (!hash)
3537 3538
		goto done;

T
Tom Herbert 已提交
3539 3540 3541
	sock_flow_table = rcu_dereference(rps_sock_flow_table);
	if (flow_table && sock_flow_table) {
		struct rps_dev_flow *rflow;
3542 3543 3544 3545 3546 3547 3548
		u32 next_cpu;
		u32 ident;

		/* First check into global flow table if there is a match */
		ident = sock_flow_table->ents[hash & sock_flow_table->mask];
		if ((ident ^ hash) & ~rps_cpu_mask)
			goto try_rps;
T
Tom Herbert 已提交
3549

3550 3551 3552 3553 3554
		next_cpu = ident & rps_cpu_mask;

		/* OK, now we know there is a match,
		 * we can look at the local (per receive queue) flow table
		 */
3555
		rflow = &flow_table->flows[hash & flow_table->mask];
T
Tom Herbert 已提交
3556 3557 3558 3559 3560 3561
		tcpu = rflow->cpu;

		/*
		 * If the desired CPU (where last recvmsg was done) is
		 * different from current CPU (one in the rx-queue flow
		 * table entry), switch if one of the following holds:
3562
		 *   - Current CPU is unset (>= nr_cpu_ids).
T
Tom Herbert 已提交
3563 3564 3565 3566 3567 3568 3569
		 *   - Current CPU is offline.
		 *   - The current CPU's queue tail has advanced beyond the
		 *     last packet that was enqueued using this table entry.
		 *     This guarantees that all previous packets for the flow
		 *     have been dequeued, thus preserving in order delivery.
		 */
		if (unlikely(tcpu != next_cpu) &&
3570
		    (tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
T
Tom Herbert 已提交
3571
		     ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
3572 3573
		      rflow->last_qtail)) >= 0)) {
			tcpu = next_cpu;
3574
			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
3575
		}
3576

3577
		if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
T
Tom Herbert 已提交
3578 3579 3580 3581 3582 3583
			*rflowp = rflow;
			cpu = tcpu;
			goto done;
		}
	}

3584 3585
try_rps:

T
Tom Herbert 已提交
3586
	if (map) {
3587
		tcpu = map->cpus[reciprocal_scale(hash, map->len)];
T
Tom Herbert 已提交
3588 3589 3590 3591 3592 3593 3594 3595 3596 3597
		if (cpu_online(tcpu)) {
			cpu = tcpu;
			goto done;
		}
	}

done:
	return cpu;
}

3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617
#ifdef CONFIG_RFS_ACCEL

/**
 * rps_may_expire_flow - check whether an RFS hardware filter may be removed
 * @dev: Device on which the filter was set
 * @rxq_index: RX queue index
 * @flow_id: Flow ID passed to ndo_rx_flow_steer()
 * @filter_id: Filter ID returned by ndo_rx_flow_steer()
 *
 * Drivers that implement ndo_rx_flow_steer() should periodically call
 * this function for each installed filter and remove the filters for
 * which it returns %true.
 */
bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
			 u32 flow_id, u16 filter_id)
{
	struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
	struct rps_dev_flow_table *flow_table;
	struct rps_dev_flow *rflow;
	bool expire = true;
3618
	unsigned int cpu;
3619 3620 3621 3622 3623 3624

	rcu_read_lock();
	flow_table = rcu_dereference(rxqueue->rps_flow_table);
	if (flow_table && flow_id <= flow_table->mask) {
		rflow = &flow_table->flows[flow_id];
		cpu = ACCESS_ONCE(rflow->cpu);
3625
		if (rflow->filter == filter_id && cpu < nr_cpu_ids &&
3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637
		    ((int)(per_cpu(softnet_data, cpu).input_queue_head -
			   rflow->last_qtail) <
		     (int)(10 * flow_table->mask)))
			expire = false;
	}
	rcu_read_unlock();
	return expire;
}
EXPORT_SYMBOL(rps_may_expire_flow);

#endif /* CONFIG_RFS_ACCEL */

T
Tom Herbert 已提交
3638
/* Called from hardirq (IPI) context */
E
Eric Dumazet 已提交
3639
static void rps_trigger_softirq(void *data)
T
Tom Herbert 已提交
3640
{
E
Eric Dumazet 已提交
3641 3642
	struct softnet_data *sd = data;

E
Eric Dumazet 已提交
3643
	____napi_schedule(sd, &sd->backlog);
C
Changli Gao 已提交
3644
	sd->received_rps++;
T
Tom Herbert 已提交
3645
}
E
Eric Dumazet 已提交
3646

T
Tom Herbert 已提交
3647
#endif /* CONFIG_RPS */
T
Tom Herbert 已提交
3648

E
Eric Dumazet 已提交
3649 3650 3651 3652 3653 3654 3655 3656
/*
 * Check if this softnet_data structure is another cpu one
 * If yes, queue it to our IPI list and return 1
 * If no, return 0
 */
static int rps_ipi_queued(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
3657
	struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
E
Eric Dumazet 已提交
3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669

	if (sd != mysd) {
		sd->rps_ipi_next = mysd->rps_ipi_list;
		mysd->rps_ipi_list = sd;

		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
		return 1;
	}
#endif /* CONFIG_RPS */
	return 0;
}

3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683
#ifdef CONFIG_NET_FLOW_LIMIT
int netdev_flow_limit_table_len __read_mostly = (1 << 12);
#endif

static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
{
#ifdef CONFIG_NET_FLOW_LIMIT
	struct sd_flow_limit *fl;
	struct softnet_data *sd;
	unsigned int old_flow, new_flow;

	if (qlen < (netdev_max_backlog >> 1))
		return false;

3684
	sd = this_cpu_ptr(&softnet_data);
3685 3686 3687 3688

	rcu_read_lock();
	fl = rcu_dereference(sd->flow_limit);
	if (fl) {
3689
		new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709
		old_flow = fl->history[fl->history_head];
		fl->history[fl->history_head] = new_flow;

		fl->history_head++;
		fl->history_head &= FLOW_LIMIT_HISTORY - 1;

		if (likely(fl->buckets[old_flow]))
			fl->buckets[old_flow]--;

		if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
			fl->count++;
			rcu_read_unlock();
			return true;
		}
	}
	rcu_read_unlock();
#endif
	return false;
}

T
Tom Herbert 已提交
3710 3711 3712 3713
/*
 * enqueue_to_backlog is called to queue an skb to a per CPU backlog
 * queue (may be a remote CPU queue).
 */
T
Tom Herbert 已提交
3714 3715
static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
			      unsigned int *qtail)
T
Tom Herbert 已提交
3716
{
E
Eric Dumazet 已提交
3717
	struct softnet_data *sd;
T
Tom Herbert 已提交
3718
	unsigned long flags;
3719
	unsigned int qlen;
T
Tom Herbert 已提交
3720

E
Eric Dumazet 已提交
3721
	sd = &per_cpu(softnet_data, cpu);
T
Tom Herbert 已提交
3722 3723 3724

	local_irq_save(flags);

E
Eric Dumazet 已提交
3725
	rps_lock(sd);
3726 3727
	if (!netif_running(skb->dev))
		goto drop;
3728 3729
	qlen = skb_queue_len(&sd->input_pkt_queue);
	if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) {
3730
		if (qlen) {
T
Tom Herbert 已提交
3731
enqueue:
E
Eric Dumazet 已提交
3732
			__skb_queue_tail(&sd->input_pkt_queue, skb);
3733
			input_queue_tail_incr_save(sd, qtail);
E
Eric Dumazet 已提交
3734
			rps_unlock(sd);
3735
			local_irq_restore(flags);
T
Tom Herbert 已提交
3736 3737 3738
			return NET_RX_SUCCESS;
		}

3739 3740 3741 3742
		/* Schedule NAPI for backlog device
		 * We can use non atomic operation since we own the queue lock
		 */
		if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state)) {
E
Eric Dumazet 已提交
3743
			if (!rps_ipi_queued(sd))
E
Eric Dumazet 已提交
3744
				____napi_schedule(sd, &sd->backlog);
T
Tom Herbert 已提交
3745 3746 3747 3748
		}
		goto enqueue;
	}

3749
drop:
C
Changli Gao 已提交
3750
	sd->dropped++;
E
Eric Dumazet 已提交
3751
	rps_unlock(sd);
T
Tom Herbert 已提交
3752 3753 3754

	local_irq_restore(flags);

3755
	atomic_long_inc(&skb->dev->rx_dropped);
T
Tom Herbert 已提交
3756 3757 3758
	kfree_skb(skb);
	return NET_RX_DROP;
}
L
Linus Torvalds 已提交
3759

3760
static int netif_rx_internal(struct sk_buff *skb)
L
Linus Torvalds 已提交
3761
{
3762
	int ret;
L
Linus Torvalds 已提交
3763

3764
	net_timestamp_check(netdev_tstamp_prequeue, skb);
L
Linus Torvalds 已提交
3765

3766
	trace_netif_rx(skb);
E
Eric Dumazet 已提交
3767
#ifdef CONFIG_RPS
3768
	if (static_key_false(&rps_needed)) {
T
Tom Herbert 已提交
3769
		struct rps_dev_flow voidflow, *rflow = &voidflow;
3770 3771
		int cpu;

3772
		preempt_disable();
3773
		rcu_read_lock();
T
Tom Herbert 已提交
3774 3775

		cpu = get_rps_cpu(skb->dev, skb, &rflow);
3776 3777
		if (cpu < 0)
			cpu = smp_processor_id();
T
Tom Herbert 已提交
3778 3779 3780

		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);

3781
		rcu_read_unlock();
3782
		preempt_enable();
3783 3784
	} else
#endif
T
Tom Herbert 已提交
3785 3786 3787 3788 3789
	{
		unsigned int qtail;
		ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
		put_cpu();
	}
3790
	return ret;
L
Linus Torvalds 已提交
3791
}
3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813

/**
 *	netif_rx	-	post buffer to the network code
 *	@skb: buffer to post
 *
 *	This function receives a packet from a device driver and queues it for
 *	the upper (protocol) levels to process.  It always succeeds. The buffer
 *	may be dropped during processing for congestion control or by the
 *	protocol layers.
 *
 *	return values:
 *	NET_RX_SUCCESS	(no congestion)
 *	NET_RX_DROP     (packet was dropped)
 *
 */

int netif_rx(struct sk_buff *skb)
{
	trace_netif_rx_entry(skb);

	return netif_rx_internal(skb);
}
E
Eric Dumazet 已提交
3814
EXPORT_SYMBOL(netif_rx);
L
Linus Torvalds 已提交
3815 3816 3817 3818 3819

int netif_rx_ni(struct sk_buff *skb)
{
	int err;

3820 3821
	trace_netif_rx_ni_entry(skb);

L
Linus Torvalds 已提交
3822
	preempt_disable();
3823
	err = netif_rx_internal(skb);
L
Linus Torvalds 已提交
3824 3825 3826 3827 3828 3829 3830 3831
	if (local_softirq_pending())
		do_softirq();
	preempt_enable();

	return err;
}
EXPORT_SYMBOL(netif_rx_ni);

3832
static __latent_entropy void net_tx_action(struct softirq_action *h)
L
Linus Torvalds 已提交
3833
{
3834
	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
L
Linus Torvalds 已提交
3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847

	if (sd->completion_queue) {
		struct sk_buff *clist;

		local_irq_disable();
		clist = sd->completion_queue;
		sd->completion_queue = NULL;
		local_irq_enable();

		while (clist) {
			struct sk_buff *skb = clist;
			clist = clist->next;

3848
			WARN_ON(atomic_read(&skb->users));
3849 3850 3851 3852
			if (likely(get_kfree_skb_cb(skb)->reason == SKB_REASON_CONSUMED))
				trace_consume_skb(skb);
			else
				trace_kfree_skb(skb, net_tx_action);
3853 3854 3855 3856 3857

			if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
				__kfree_skb(skb);
			else
				__kfree_skb_defer(skb);
L
Linus Torvalds 已提交
3858
		}
3859 3860

		__kfree_skb_flush();
L
Linus Torvalds 已提交
3861 3862 3863
	}

	if (sd->output_queue) {
3864
		struct Qdisc *head;
L
Linus Torvalds 已提交
3865 3866 3867 3868

		local_irq_disable();
		head = sd->output_queue;
		sd->output_queue = NULL;
3869
		sd->output_queue_tailp = &sd->output_queue;
L
Linus Torvalds 已提交
3870 3871 3872
		local_irq_enable();

		while (head) {
3873 3874 3875
			struct Qdisc *q = head;
			spinlock_t *root_lock;

L
Linus Torvalds 已提交
3876 3877
			head = head->next_sched;

3878
			root_lock = qdisc_lock(q);
3879 3880 3881 3882 3883 3884 3885 3886
			spin_lock(root_lock);
			/* We need to make sure head->next_sched is read
			 * before clearing __QDISC_STATE_SCHED
			 */
			smp_mb__before_atomic();
			clear_bit(__QDISC_STATE_SCHED, &q->state);
			qdisc_run(q);
			spin_unlock(root_lock);
L
Linus Torvalds 已提交
3887 3888 3889 3890
		}
	}
}

3891
#if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
3892 3893 3894
/* This hook is defined here for ATM LANE */
int (*br_fdb_test_addr_hook)(struct net_device *dev,
			     unsigned char *addr) __read_mostly;
3895
EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
3896
#endif
L
Linus Torvalds 已提交
3897

D
Daniel Borkmann 已提交
3898 3899 3900
static inline struct sk_buff *
sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
		   struct net_device *orig_dev)
3901
{
3902
#ifdef CONFIG_NET_CLS_ACT
3903 3904
	struct tcf_proto *cl = rcu_dereference_bh(skb->dev->ingress_cl_list);
	struct tcf_result cl_res;
3905

3906 3907 3908
	/* If there's at least one ingress present somewhere (so
	 * we get here via enabled static key), remaining devices
	 * that are not configured with an ingress qdisc will bail
3909
	 * out here.
3910
	 */
3911
	if (!cl)
3912
		return skb;
3913 3914 3915
	if (*pt_prev) {
		*ret = deliver_skb(skb, *pt_prev, orig_dev);
		*pt_prev = NULL;
L
Linus Torvalds 已提交
3916 3917
	}

3918
	qdisc_skb_cb(skb)->pkt_len = skb->len;
3919
	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS);
3920
	qdisc_bstats_cpu_update(cl->q, skb);
3921

3922
	switch (tc_classify(skb, cl, &cl_res, false)) {
3923 3924 3925 3926 3927
	case TC_ACT_OK:
	case TC_ACT_RECLASSIFY:
		skb->tc_index = TC_H_MIN(cl_res.classid);
		break;
	case TC_ACT_SHOT:
3928
		qdisc_qstats_cpu_drop(cl->q);
3929 3930
		kfree_skb(skb);
		return NULL;
3931 3932
	case TC_ACT_STOLEN:
	case TC_ACT_QUEUED:
3933
		consume_skb(skb);
3934
		return NULL;
3935 3936 3937 3938 3939 3940 3941 3942
	case TC_ACT_REDIRECT:
		/* skb_mac_header check was done by cls/act_bpf, so
		 * we can safely push the L2 header back before
		 * redirecting to another netdev
		 */
		__skb_push(skb, skb->mac_len);
		skb_do_redirect(skb);
		return NULL;
3943 3944
	default:
		break;
3945
	}
3946
#endif /* CONFIG_NET_CLS_ACT */
3947 3948
	return skb;
}
L
Linus Torvalds 已提交
3949

M
Mahesh Bandewar 已提交
3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965
/**
 *	netdev_is_rx_handler_busy - check if receive handler is registered
 *	@dev: device to check
 *
 *	Check if a receive handler is already registered for a given device.
 *	Return true if there one.
 *
 *	The caller must hold the rtnl_mutex.
 */
bool netdev_is_rx_handler_busy(struct net_device *dev)
{
	ASSERT_RTNL();
	return dev && rtnl_dereference(dev->rx_handler);
}
EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);

3966 3967 3968 3969
/**
 *	netdev_rx_handler_register - register receive handler
 *	@dev: device to register a handler for
 *	@rx_handler: receive handler to register
J
Jiri Pirko 已提交
3970
 *	@rx_handler_data: data pointer that is used by rx handler
3971
 *
3972
 *	Register a receive handler for a device. This handler will then be
3973 3974 3975 3976
 *	called from __netif_receive_skb. A negative errno code is returned
 *	on a failure.
 *
 *	The caller must hold the rtnl_mutex.
3977 3978
 *
 *	For a general description of rx_handler, see enum rx_handler_result.
3979 3980
 */
int netdev_rx_handler_register(struct net_device *dev,
J
Jiri Pirko 已提交
3981 3982
			       rx_handler_func_t *rx_handler,
			       void *rx_handler_data)
3983 3984 3985 3986 3987 3988
{
	ASSERT_RTNL();

	if (dev->rx_handler)
		return -EBUSY;

3989
	/* Note: rx_handler_data must be set before rx_handler */
J
Jiri Pirko 已提交
3990
	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
3991 3992 3993 3994 3995 3996 3997 3998 3999 4000
	rcu_assign_pointer(dev->rx_handler, rx_handler);

	return 0;
}
EXPORT_SYMBOL_GPL(netdev_rx_handler_register);

/**
 *	netdev_rx_handler_unregister - unregister receive handler
 *	@dev: device to unregister a handler from
 *
K
Kusanagi Kouichi 已提交
4001
 *	Unregister a receive handler from a device.
4002 4003 4004 4005 4006 4007 4008
 *
 *	The caller must hold the rtnl_mutex.
 */
void netdev_rx_handler_unregister(struct net_device *dev)
{

	ASSERT_RTNL();
4009
	RCU_INIT_POINTER(dev->rx_handler, NULL);
4010 4011 4012 4013 4014
	/* a reader seeing a non NULL rx_handler in a rcu_read_lock()
	 * section has a guarantee to see a non NULL rx_handler_data
	 * as well.
	 */
	synchronize_net();
4015
	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
4016 4017 4018
}
EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);

4019 4020 4021 4022 4023 4024 4025
/*
 * Limit the use of PFMEMALLOC reserves to those protocols that implement
 * the special handling of PFMEMALLOC skbs.
 */
static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
{
	switch (skb->protocol) {
4026 4027 4028 4029 4030
	case htons(ETH_P_ARP):
	case htons(ETH_P_IP):
	case htons(ETH_P_IPV6):
	case htons(ETH_P_8021Q):
	case htons(ETH_P_8021AD):
4031 4032 4033 4034 4035 4036
		return true;
	default:
		return false;
	}
}

4037 4038 4039
static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
			     int *ret, struct net_device *orig_dev)
{
4040
#ifdef CONFIG_NETFILTER_INGRESS
4041
	if (nf_hook_ingress_active(skb)) {
4042 4043
		int ingress_retval;

4044 4045 4046 4047 4048
		if (*pt_prev) {
			*ret = deliver_skb(skb, *pt_prev, orig_dev);
			*pt_prev = NULL;
		}

4049 4050 4051 4052
		rcu_read_lock();
		ingress_retval = nf_hook_ingress(skb);
		rcu_read_unlock();
		return ingress_retval;
4053
	}
4054
#endif /* CONFIG_NETFILTER_INGRESS */
4055 4056 4057
	return 0;
}

4058
static int __netif_receive_skb_core(struct sk_buff *skb, bool pfmemalloc)
L
Linus Torvalds 已提交
4059 4060
{
	struct packet_type *ptype, *pt_prev;
4061
	rx_handler_func_t *rx_handler;
D
David S. Miller 已提交
4062
	struct net_device *orig_dev;
4063
	bool deliver_exact = false;
L
Linus Torvalds 已提交
4064
	int ret = NET_RX_DROP;
A
Al Viro 已提交
4065
	__be16 type;
L
Linus Torvalds 已提交
4066

4067
	net_timestamp_check(!netdev_tstamp_prequeue, skb);
4068

4069
	trace_netif_receive_skb(skb);
4070

J
Joe Eykholt 已提交
4071
	orig_dev = skb->dev;
4072

4073
	skb_reset_network_header(skb);
4074 4075
	if (!skb_transport_header_was_set(skb))
		skb_reset_transport_header(skb);
4076
	skb_reset_mac_len(skb);
L
Linus Torvalds 已提交
4077 4078 4079

	pt_prev = NULL;

4080
another_round:
4081
	skb->skb_iif = skb->dev->ifindex;
4082 4083 4084

	__this_cpu_inc(softnet_data.processed);

P
Patrick McHardy 已提交
4085 4086
	if (skb->protocol == cpu_to_be16(ETH_P_8021Q) ||
	    skb->protocol == cpu_to_be16(ETH_P_8021AD)) {
4087
		skb = skb_vlan_untag(skb);
4088
		if (unlikely(!skb))
4089
			goto out;
4090 4091
	}

L
Linus Torvalds 已提交
4092 4093 4094 4095 4096 4097 4098
#ifdef CONFIG_NET_CLS_ACT
	if (skb->tc_verd & TC_NCLS) {
		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
		goto ncls;
	}
#endif

4099
	if (pfmemalloc)
4100 4101
		goto skip_taps;

L
Linus Torvalds 已提交
4102
	list_for_each_entry_rcu(ptype, &ptype_all, list) {
4103 4104 4105 4106 4107 4108 4109 4110 4111
		if (pt_prev)
			ret = deliver_skb(skb, pt_prev, orig_dev);
		pt_prev = ptype;
	}

	list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
		if (pt_prev)
			ret = deliver_skb(skb, pt_prev, orig_dev);
		pt_prev = ptype;
L
Linus Torvalds 已提交
4112 4113
	}

4114
skip_taps:
4115
#ifdef CONFIG_NET_INGRESS
4116
	if (static_key_false(&ingress_needed)) {
D
Daniel Borkmann 已提交
4117
		skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev);
4118
		if (!skb)
4119
			goto out;
4120 4121

		if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
4122
			goto out;
4123
	}
4124 4125
#endif
#ifdef CONFIG_NET_CLS_ACT
4126
	skb->tc_verd = 0;
L
Linus Torvalds 已提交
4127 4128
ncls:
#endif
4129
	if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
4130 4131
		goto drop;

4132
	if (skb_vlan_tag_present(skb)) {
4133 4134 4135 4136
		if (pt_prev) {
			ret = deliver_skb(skb, pt_prev, orig_dev);
			pt_prev = NULL;
		}
4137
		if (vlan_do_receive(&skb))
4138 4139
			goto another_round;
		else if (unlikely(!skb))
4140
			goto out;
4141 4142
	}

4143
	rx_handler = rcu_dereference(skb->dev->rx_handler);
4144 4145 4146 4147 4148
	if (rx_handler) {
		if (pt_prev) {
			ret = deliver_skb(skb, pt_prev, orig_dev);
			pt_prev = NULL;
		}
4149 4150
		switch (rx_handler(&skb)) {
		case RX_HANDLER_CONSUMED:
4151
			ret = NET_RX_SUCCESS;
4152
			goto out;
4153
		case RX_HANDLER_ANOTHER:
4154
			goto another_round;
4155 4156 4157 4158 4159 4160 4161
		case RX_HANDLER_EXACT:
			deliver_exact = true;
		case RX_HANDLER_PASS:
			break;
		default:
			BUG();
		}
4162
	}
L
Linus Torvalds 已提交
4163

4164 4165
	if (unlikely(skb_vlan_tag_present(skb))) {
		if (skb_vlan_tag_get_id(skb))
E
Eric Dumazet 已提交
4166 4167 4168 4169 4170 4171 4172
			skb->pkt_type = PACKET_OTHERHOST;
		/* Note: we might in the future use prio bits
		 * and set skb->priority like in vlan_do_receive()
		 * For the time being, just ignore Priority Code Point
		 */
		skb->vlan_tci = 0;
	}
4173

4174 4175
	type = skb->protocol;

4176
	/* deliver only exact match when indicated */
4177 4178 4179 4180 4181
	if (likely(!deliver_exact)) {
		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
				       &ptype_base[ntohs(type) &
						   PTYPE_HASH_MASK]);
	}
4182

4183 4184 4185 4186 4187 4188
	deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
			       &orig_dev->ptype_specific);

	if (unlikely(skb->dev != orig_dev)) {
		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
				       &skb->dev->ptype_specific);
L
Linus Torvalds 已提交
4189 4190 4191
	}

	if (pt_prev) {
4192
		if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
4193
			goto drop;
4194 4195
		else
			ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
L
Linus Torvalds 已提交
4196
	} else {
4197
drop:
4198 4199 4200 4201
		if (!deliver_exact)
			atomic_long_inc(&skb->dev->rx_dropped);
		else
			atomic_long_inc(&skb->dev->rx_nohandler);
L
Linus Torvalds 已提交
4202 4203 4204 4205 4206 4207 4208
		kfree_skb(skb);
		/* Jamal, now you will not able to escape explaining
		 * me how you were going to use this. :-)
		 */
		ret = NET_RX_DROP;
	}

4209
out:
4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234
	return ret;
}

static int __netif_receive_skb(struct sk_buff *skb)
{
	int ret;

	if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
		unsigned long pflags = current->flags;

		/*
		 * PFMEMALLOC skbs are special, they should
		 * - be delivered to SOCK_MEMALLOC sockets only
		 * - stay away from userspace
		 * - have bounded memory usage
		 *
		 * Use PF_MEMALLOC as this saves us from propagating the allocation
		 * context down to all allocation sites.
		 */
		current->flags |= PF_MEMALLOC;
		ret = __netif_receive_skb_core(skb, true);
		tsk_restore_flags(current, pflags, PF_MEMALLOC);
	} else
		ret = __netif_receive_skb_core(skb, false);

L
Linus Torvalds 已提交
4235 4236
	return ret;
}
T
Tom Herbert 已提交
4237

4238
static int netif_receive_skb_internal(struct sk_buff *skb)
T
Tom Herbert 已提交
4239
{
4240 4241
	int ret;

4242
	net_timestamp_check(netdev_tstamp_prequeue, skb);
E
Eric Dumazet 已提交
4243

4244 4245 4246
	if (skb_defer_rx_timestamp(skb))
		return NET_RX_SUCCESS;

4247 4248
	rcu_read_lock();

E
Eric Dumazet 已提交
4249
#ifdef CONFIG_RPS
4250
	if (static_key_false(&rps_needed)) {
E
Eric Dumazet 已提交
4251
		struct rps_dev_flow voidflow, *rflow = &voidflow;
4252
		int cpu = get_rps_cpu(skb->dev, skb, &rflow);
T
Tom Herbert 已提交
4253

E
Eric Dumazet 已提交
4254 4255 4256
		if (cpu >= 0) {
			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
			rcu_read_unlock();
4257
			return ret;
E
Eric Dumazet 已提交
4258
		}
T
Tom Herbert 已提交
4259
	}
4260
#endif
4261 4262 4263
	ret = __netif_receive_skb(skb);
	rcu_read_unlock();
	return ret;
T
Tom Herbert 已提交
4264
}
4265 4266 4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277 4278 4279 4280

/**
 *	netif_receive_skb - process receive buffer from network
 *	@skb: buffer to process
 *
 *	netif_receive_skb() is the main receive data processing function.
 *	It always succeeds. The buffer may be dropped during processing
 *	for congestion control or by the protocol layers.
 *
 *	This function may only be called from softirq context and interrupts
 *	should be enabled.
 *
 *	Return values (usually ignored):
 *	NET_RX_SUCCESS: no congestion
 *	NET_RX_DROP: packet was dropped
 */
4281
int netif_receive_skb(struct sk_buff *skb)
4282 4283 4284 4285 4286
{
	trace_netif_receive_skb_entry(skb);

	return netif_receive_skb_internal(skb);
}
4287
EXPORT_SYMBOL(netif_receive_skb);
L
Linus Torvalds 已提交
4288

4289
DEFINE_PER_CPU(struct work_struct, flush_works);
4290 4291 4292

/* Network device is going away, flush any packets still pending */
static void flush_backlog(struct work_struct *work)
4293 4294
{
	struct sk_buff *skb, *tmp;
4295 4296 4297 4298
	struct softnet_data *sd;

	local_bh_disable();
	sd = this_cpu_ptr(&softnet_data);
4299

4300
	local_irq_disable();
E
Eric Dumazet 已提交
4301
	rps_lock(sd);
4302
	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
4303
		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
E
Eric Dumazet 已提交
4304
			__skb_unlink(skb, &sd->input_pkt_queue);
4305
			kfree_skb(skb);
4306
			input_queue_head_incr(sd);
4307
		}
4308
	}
E
Eric Dumazet 已提交
4309
	rps_unlock(sd);
4310
	local_irq_enable();
4311 4312

	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
4313
		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
4314 4315
			__skb_unlink(skb, &sd->process_queue);
			kfree_skb(skb);
4316
			input_queue_head_incr(sd);
4317 4318
		}
	}
4319 4320 4321
	local_bh_enable();
}

4322
static void flush_all_backlogs(void)
4323 4324 4325 4326 4327
{
	unsigned int cpu;

	get_online_cpus();

4328 4329 4330
	for_each_online_cpu(cpu)
		queue_work_on(cpu, system_highpri_wq,
			      per_cpu_ptr(&flush_works, cpu));
4331 4332

	for_each_online_cpu(cpu)
4333
		flush_work(per_cpu_ptr(&flush_works, cpu));
4334 4335

	put_online_cpus();
4336 4337
}

4338 4339
static int napi_gro_complete(struct sk_buff *skb)
{
4340
	struct packet_offload *ptype;
4341
	__be16 type = skb->protocol;
4342
	struct list_head *head = &offload_base;
4343 4344
	int err = -ENOENT;

4345 4346
	BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));

4347 4348
	if (NAPI_GRO_CB(skb)->count == 1) {
		skb_shinfo(skb)->gso_size = 0;
4349
		goto out;
4350
	}
4351 4352 4353

	rcu_read_lock();
	list_for_each_entry_rcu(ptype, head, list) {
4354
		if (ptype->type != type || !ptype->callbacks.gro_complete)
4355 4356
			continue;

4357
		err = ptype->callbacks.gro_complete(skb, 0);
4358 4359 4360 4361 4362 4363 4364 4365 4366 4367 4368
		break;
	}
	rcu_read_unlock();

	if (err) {
		WARN_ON(&ptype->list == head);
		kfree_skb(skb);
		return NET_RX_SUCCESS;
	}

out:
4369
	return netif_receive_skb_internal(skb);
4370 4371
}

4372 4373 4374 4375 4376
/* napi->gro_list contains packets ordered by age.
 * youngest packets at the head of it.
 * Complete skbs in reverse order to reduce latencies.
 */
void napi_gro_flush(struct napi_struct *napi, bool flush_old)
4377
{
4378
	struct sk_buff *skb, *prev = NULL;
4379

4380 4381 4382 4383 4384 4385 4386
	/* scan list and build reverse chain */
	for (skb = napi->gro_list; skb != NULL; skb = skb->next) {
		skb->prev = prev;
		prev = skb;
	}

	for (skb = prev; skb; skb = prev) {
4387
		skb->next = NULL;
4388 4389 4390 4391 4392

		if (flush_old && NAPI_GRO_CB(skb)->age == jiffies)
			return;

		prev = skb->prev;
4393
		napi_gro_complete(skb);
4394
		napi->gro_count--;
4395 4396 4397 4398
	}

	napi->gro_list = NULL;
}
E
Eric Dumazet 已提交
4399
EXPORT_SYMBOL(napi_gro_flush);
4400

E
Eric Dumazet 已提交
4401 4402 4403 4404
static void gro_list_prepare(struct napi_struct *napi, struct sk_buff *skb)
{
	struct sk_buff *p;
	unsigned int maclen = skb->dev->hard_header_len;
4405
	u32 hash = skb_get_hash_raw(skb);
E
Eric Dumazet 已提交
4406 4407 4408 4409

	for (p = napi->gro_list; p; p = p->next) {
		unsigned long diffs;

4410 4411 4412 4413 4414 4415 4416
		NAPI_GRO_CB(p)->flush = 0;

		if (hash != skb_get_hash_raw(p)) {
			NAPI_GRO_CB(p)->same_flow = 0;
			continue;
		}

E
Eric Dumazet 已提交
4417 4418
		diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
		diffs |= p->vlan_tci ^ skb->vlan_tci;
4419
		diffs |= skb_metadata_dst_cmp(p, skb);
E
Eric Dumazet 已提交
4420 4421
		if (maclen == ETH_HLEN)
			diffs |= compare_ether_header(skb_mac_header(p),
4422
						      skb_mac_header(skb));
E
Eric Dumazet 已提交
4423 4424
		else if (!diffs)
			diffs = memcmp(skb_mac_header(p),
4425
				       skb_mac_header(skb),
E
Eric Dumazet 已提交
4426 4427 4428 4429 4430
				       maclen);
		NAPI_GRO_CB(p)->same_flow = !diffs;
	}
}

4431 4432 4433 4434 4435 4436 4437 4438 4439 4440 4441 4442 4443
static void skb_gro_reset_offset(struct sk_buff *skb)
{
	const struct skb_shared_info *pinfo = skb_shinfo(skb);
	const skb_frag_t *frag0 = &pinfo->frags[0];

	NAPI_GRO_CB(skb)->data_offset = 0;
	NAPI_GRO_CB(skb)->frag0 = NULL;
	NAPI_GRO_CB(skb)->frag0_len = 0;

	if (skb_mac_header(skb) == skb_tail_pointer(skb) &&
	    pinfo->nr_frags &&
	    !PageHighMem(skb_frag_page(frag0))) {
		NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0);
4444 4445
		NAPI_GRO_CB(skb)->frag0_len = min(skb_frag_size(frag0),
						  skb->end - skb->tail);
E
Eric Dumazet 已提交
4446 4447 4448
	}
}

4449 4450 4451 4452 4453 4454 4455 4456 4457 4458 4459 4460 4461 4462 4463 4464 4465 4466 4467 4468 4469
static void gro_pull_from_frag0(struct sk_buff *skb, int grow)
{
	struct skb_shared_info *pinfo = skb_shinfo(skb);

	BUG_ON(skb->end - skb->tail < grow);

	memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);

	skb->data_len -= grow;
	skb->tail += grow;

	pinfo->frags[0].page_offset += grow;
	skb_frag_size_sub(&pinfo->frags[0], grow);

	if (unlikely(!skb_frag_size(&pinfo->frags[0]))) {
		skb_frag_unref(skb, 0);
		memmove(pinfo->frags, pinfo->frags + 1,
			--pinfo->nr_frags * sizeof(pinfo->frags[0]));
	}
}

R
Rami Rosen 已提交
4470
static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
4471 4472
{
	struct sk_buff **pp = NULL;
4473
	struct packet_offload *ptype;
4474
	__be16 type = skb->protocol;
4475
	struct list_head *head = &offload_base;
H
Herbert Xu 已提交
4476
	int same_flow;
4477
	enum gro_result ret;
4478
	int grow;
4479

4480
	if (!(skb->dev->features & NETIF_F_GRO))
4481 4482
		goto normal;

E
Eric Dumazet 已提交
4483
	if (skb->csum_bad)
4484 4485
		goto normal;

E
Eric Dumazet 已提交
4486 4487
	gro_list_prepare(napi, skb);

4488 4489
	rcu_read_lock();
	list_for_each_entry_rcu(ptype, head, list) {
4490
		if (ptype->type != type || !ptype->callbacks.gro_receive)
4491 4492
			continue;

4493
		skb_set_network_header(skb, skb_gro_offset(skb));
4494
		skb_reset_mac_len(skb);
4495
		NAPI_GRO_CB(skb)->same_flow = 0;
E
Eric Dumazet 已提交
4496
		NAPI_GRO_CB(skb)->flush = skb_is_gso(skb) || skb_has_frag_list(skb);
H
Herbert Xu 已提交
4497
		NAPI_GRO_CB(skb)->free = 0;
4498
		NAPI_GRO_CB(skb)->encap_mark = 0;
S
Sabrina Dubroca 已提交
4499
		NAPI_GRO_CB(skb)->recursion_counter = 0;
4500
		NAPI_GRO_CB(skb)->is_fou = 0;
4501
		NAPI_GRO_CB(skb)->is_atomic = 1;
4502
		NAPI_GRO_CB(skb)->gro_remcsum_start = 0;
4503

4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515 4516 4517 4518
		/* Setup for GRO checksum validation */
		switch (skb->ip_summed) {
		case CHECKSUM_COMPLETE:
			NAPI_GRO_CB(skb)->csum = skb->csum;
			NAPI_GRO_CB(skb)->csum_valid = 1;
			NAPI_GRO_CB(skb)->csum_cnt = 0;
			break;
		case CHECKSUM_UNNECESSARY:
			NAPI_GRO_CB(skb)->csum_cnt = skb->csum_level + 1;
			NAPI_GRO_CB(skb)->csum_valid = 0;
			break;
		default:
			NAPI_GRO_CB(skb)->csum_cnt = 0;
			NAPI_GRO_CB(skb)->csum_valid = 0;
		}
4519

4520
		pp = ptype->callbacks.gro_receive(&napi->gro_list, skb);
4521 4522 4523 4524 4525 4526 4527
		break;
	}
	rcu_read_unlock();

	if (&ptype->list == head)
		goto normal;

H
Herbert Xu 已提交
4528
	same_flow = NAPI_GRO_CB(skb)->same_flow;
4529
	ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
H
Herbert Xu 已提交
4530

4531 4532 4533 4534 4535 4536
	if (pp) {
		struct sk_buff *nskb = *pp;

		*pp = nskb->next;
		nskb->next = NULL;
		napi_gro_complete(nskb);
4537
		napi->gro_count--;
4538 4539
	}

H
Herbert Xu 已提交
4540
	if (same_flow)
4541 4542
		goto ok;

4543
	if (NAPI_GRO_CB(skb)->flush)
4544 4545
		goto normal;

4546 4547 4548 4549 4550 4551 4552 4553 4554 4555 4556 4557 4558 4559
	if (unlikely(napi->gro_count >= MAX_GRO_SKBS)) {
		struct sk_buff *nskb = napi->gro_list;

		/* locate the end of the list to select the 'oldest' flow */
		while (nskb->next) {
			pp = &nskb->next;
			nskb = *pp;
		}
		*pp = NULL;
		nskb->next = NULL;
		napi_gro_complete(nskb);
	} else {
		napi->gro_count++;
	}
4560
	NAPI_GRO_CB(skb)->count = 1;
4561
	NAPI_GRO_CB(skb)->age = jiffies;
4562
	NAPI_GRO_CB(skb)->last = skb;
4563
	skb_shinfo(skb)->gso_size = skb_gro_len(skb);
4564 4565
	skb->next = napi->gro_list;
	napi->gro_list = skb;
4566
	ret = GRO_HELD;
4567

4568
pull:
4569 4570 4571
	grow = skb_gro_offset(skb) - skb_headlen(skb);
	if (grow > 0)
		gro_pull_from_frag0(skb, grow);
4572
ok:
4573
	return ret;
4574 4575

normal:
4576 4577
	ret = GRO_NORMAL;
	goto pull;
H
Herbert Xu 已提交
4578
}
4579

4580 4581 4582 4583 4584 4585 4586 4587 4588 4589 4590 4591
struct packet_offload *gro_find_receive_by_type(__be16 type)
{
	struct list_head *offload_head = &offload_base;
	struct packet_offload *ptype;

	list_for_each_entry_rcu(ptype, offload_head, list) {
		if (ptype->type != type || !ptype->callbacks.gro_receive)
			continue;
		return ptype;
	}
	return NULL;
}
4592
EXPORT_SYMBOL(gro_find_receive_by_type);
4593 4594 4595 4596 4597 4598 4599 4600 4601 4602 4603 4604 4605

struct packet_offload *gro_find_complete_by_type(__be16 type)
{
	struct list_head *offload_head = &offload_base;
	struct packet_offload *ptype;

	list_for_each_entry_rcu(ptype, offload_head, list) {
		if (ptype->type != type || !ptype->callbacks.gro_complete)
			continue;
		return ptype;
	}
	return NULL;
}
4606
EXPORT_SYMBOL(gro_find_complete_by_type);
H
Herbert Xu 已提交
4607

R
Rami Rosen 已提交
4608
static gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
H
Herbert Xu 已提交
4609
{
4610 4611
	switch (ret) {
	case GRO_NORMAL:
4612
		if (netif_receive_skb_internal(skb))
4613 4614
			ret = GRO_DROP;
		break;
H
Herbert Xu 已提交
4615

4616
	case GRO_DROP:
H
Herbert Xu 已提交
4617 4618
		kfree_skb(skb);
		break;
4619

4620
	case GRO_MERGED_FREE:
4621 4622
		if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD) {
			skb_dst_drop(skb);
4623
			kmem_cache_free(skbuff_head_cache, skb);
4624
		} else {
4625
			__kfree_skb(skb);
4626
		}
4627 4628
		break;

4629 4630 4631
	case GRO_HELD:
	case GRO_MERGED:
		break;
H
Herbert Xu 已提交
4632 4633
	}

4634
	return ret;
4635 4636
}

4637
gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
4638
{
4639
	skb_mark_napi_id(skb, napi);
4640
	trace_napi_gro_receive_entry(skb);
4641

4642 4643
	skb_gro_reset_offset(skb);

E
Eric Dumazet 已提交
4644
	return napi_skb_finish(dev_gro_receive(napi, skb), skb);
4645 4646 4647
}
EXPORT_SYMBOL(napi_gro_receive);

S
stephen hemminger 已提交
4648
static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
4649
{
4650 4651 4652 4653
	if (unlikely(skb->pfmemalloc)) {
		consume_skb(skb);
		return;
	}
4654
	__skb_pull(skb, skb_headlen(skb));
4655 4656
	/* restore the reserve we had after netdev_alloc_skb_ip_align() */
	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
4657
	skb->vlan_tci = 0;
H
Herbert Xu 已提交
4658
	skb->dev = napi->dev;
A
Andy Gospodarek 已提交
4659
	skb->skb_iif = 0;
4660 4661
	skb->encapsulation = 0;
	skb_shinfo(skb)->gso_type = 0;
4662
	skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
4663 4664 4665 4666

	napi->skb = skb;
}

4667
struct sk_buff *napi_get_frags(struct napi_struct *napi)
H
Herbert Xu 已提交
4668 4669 4670 4671
{
	struct sk_buff *skb = napi->skb;

	if (!skb) {
4672
		skb = napi_alloc_skb(napi, GRO_MAX_HEAD);
4673 4674 4675 4676
		if (skb) {
			napi->skb = skb;
			skb_mark_napi_id(skb, napi);
		}
4677
	}
4678 4679
	return skb;
}
4680
EXPORT_SYMBOL(napi_get_frags);
4681

4682 4683 4684
static gro_result_t napi_frags_finish(struct napi_struct *napi,
				      struct sk_buff *skb,
				      gro_result_t ret)
4685
{
4686 4687
	switch (ret) {
	case GRO_NORMAL:
4688 4689 4690 4691
	case GRO_HELD:
		__skb_push(skb, ETH_HLEN);
		skb->protocol = eth_type_trans(skb, skb->dev);
		if (ret == GRO_NORMAL && netif_receive_skb_internal(skb))
4692
			ret = GRO_DROP;
4693
		break;
H
Herbert Xu 已提交
4694

4695 4696 4697 4698
	case GRO_DROP:
	case GRO_MERGED_FREE:
		napi_reuse_skb(napi, skb);
		break;
4699 4700 4701

	case GRO_MERGED:
		break;
4702
	}
H
Herbert Xu 已提交
4703

4704
	return ret;
H
Herbert Xu 已提交
4705
}
4706

4707 4708 4709 4710
/* Upper GRO stack assumes network header starts at gro_offset=0
 * Drivers could call both napi_gro_frags() and napi_gro_receive()
 * We copy ethernet header into skb->data to have a common layout.
 */
E
Eric Dumazet 已提交
4711
static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
4712 4713
{
	struct sk_buff *skb = napi->skb;
4714 4715
	const struct ethhdr *eth;
	unsigned int hlen = sizeof(*eth);
4716 4717 4718

	napi->skb = NULL;

4719 4720 4721 4722 4723 4724 4725
	skb_reset_mac_header(skb);
	skb_gro_reset_offset(skb);

	eth = skb_gro_header_fast(skb, 0);
	if (unlikely(skb_gro_header_hard(skb, hlen))) {
		eth = skb_gro_header_slow(skb, hlen, 0);
		if (unlikely(!eth)) {
4726 4727
			net_warn_ratelimited("%s: dropping impossible skb from %s\n",
					     __func__, napi->dev->name);
4728 4729 4730 4731 4732 4733 4734
			napi_reuse_skb(napi, skb);
			return NULL;
		}
	} else {
		gro_pull_from_frag0(skb, hlen);
		NAPI_GRO_CB(skb)->frag0 += hlen;
		NAPI_GRO_CB(skb)->frag0_len -= hlen;
4735
	}
4736 4737 4738 4739 4740 4741 4742 4743
	__skb_pull(skb, hlen);

	/*
	 * This works because the only protocols we care about don't require
	 * special handling.
	 * We'll fix it up properly in napi_frags_finish()
	 */
	skb->protocol = eth->h_proto;
4744 4745 4746 4747

	return skb;
}

4748
gro_result_t napi_gro_frags(struct napi_struct *napi)
4749
{
4750
	struct sk_buff *skb = napi_frags_skb(napi);
4751 4752

	if (!skb)
4753
		return GRO_DROP;
4754

4755 4756
	trace_napi_gro_frags_entry(skb);

E
Eric Dumazet 已提交
4757
	return napi_frags_finish(napi, skb, dev_gro_receive(napi, skb));
4758
}
H
Herbert Xu 已提交
4759 4760
EXPORT_SYMBOL(napi_gro_frags);

T
Tom Herbert 已提交
4761 4762 4763 4764 4765 4766 4767 4768 4769 4770 4771 4772 4773 4774 4775 4776 4777 4778 4779 4780 4781 4782 4783 4784 4785
/* Compute the checksum from gro_offset and return the folded value
 * after adding in any pseudo checksum.
 */
__sum16 __skb_gro_checksum_complete(struct sk_buff *skb)
{
	__wsum wsum;
	__sum16 sum;

	wsum = skb_checksum(skb, skb_gro_offset(skb), skb_gro_len(skb), 0);

	/* NAPI_GRO_CB(skb)->csum holds pseudo checksum */
	sum = csum_fold(csum_add(NAPI_GRO_CB(skb)->csum, wsum));
	if (likely(!sum)) {
		if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
		    !skb->csum_complete_sw)
			netdev_rx_csum_fault(skb->dev);
	}

	NAPI_GRO_CB(skb)->csum = wsum;
	NAPI_GRO_CB(skb)->csum_valid = 1;

	return sum;
}
EXPORT_SYMBOL(__skb_gro_checksum_complete);

4786
/*
4787
 * net_rps_action_and_irq_enable sends any pending IPI's for rps.
4788 4789 4790 4791 4792 4793 4794 4795 4796 4797 4798 4799 4800 4801 4802 4803 4804
 * Note: called with local irq disabled, but exits with local irq enabled.
 */
static void net_rps_action_and_irq_enable(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
	struct softnet_data *remsd = sd->rps_ipi_list;

	if (remsd) {
		sd->rps_ipi_list = NULL;

		local_irq_enable();

		/* Send pending IPI's to kick RPS processing on remote cpus. */
		while (remsd) {
			struct softnet_data *next = remsd->rps_ipi_next;

			if (cpu_online(remsd->cpu))
4805
				smp_call_function_single_async(remsd->cpu,
4806
							   &remsd->csd);
4807 4808 4809 4810 4811 4812 4813
			remsd = next;
		}
	} else
#endif
		local_irq_enable();
}

E
Eric Dumazet 已提交
4814 4815 4816 4817 4818 4819 4820 4821 4822
static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
	return sd->rps_ipi_list != NULL;
#else
	return false;
#endif
}

4823
static int process_backlog(struct napi_struct *napi, int quota)
L
Linus Torvalds 已提交
4824
{
E
Eric Dumazet 已提交
4825
	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
4826 4827
	bool again = true;
	int work = 0;
L
Linus Torvalds 已提交
4828

4829 4830 4831
	/* Check if we have pending ipi, its better to send them now,
	 * not waiting net_rx_action() end.
	 */
E
Eric Dumazet 已提交
4832
	if (sd_has_rps_ipi_waiting(sd)) {
4833 4834 4835
		local_irq_disable();
		net_rps_action_and_irq_enable(sd);
	}
E
Eric Dumazet 已提交
4836

4837
	napi->weight = weight_p;
4838
	while (again) {
L
Linus Torvalds 已提交
4839
		struct sk_buff *skb;
4840 4841

		while ((skb = __skb_dequeue(&sd->process_queue))) {
4842
			rcu_read_lock();
4843
			__netif_receive_skb(skb);
4844
			rcu_read_unlock();
4845
			input_queue_head_incr(sd);
4846
			if (++work >= quota)
4847
				return work;
4848

4849
		}
L
Linus Torvalds 已提交
4850

4851
		local_irq_disable();
E
Eric Dumazet 已提交
4852
		rps_lock(sd);
4853
		if (skb_queue_empty(&sd->input_pkt_queue)) {
E
Eric Dumazet 已提交
4854 4855 4856
			/*
			 * Inline a custom version of __napi_complete().
			 * only current cpu owns and manipulates this napi,
4857 4858 4859
			 * and NAPI_STATE_SCHED is the only possible flag set
			 * on backlog.
			 * We can use a plain write instead of clear_bit(),
E
Eric Dumazet 已提交
4860 4861 4862
			 * and we dont need an smp_mb() memory barrier.
			 */
			napi->state = 0;
4863 4864 4865 4866
			again = false;
		} else {
			skb_queue_splice_tail_init(&sd->input_pkt_queue,
						   &sd->process_queue);
4867
		}
E
Eric Dumazet 已提交
4868
		rps_unlock(sd);
4869
		local_irq_enable();
4870
	}
L
Linus Torvalds 已提交
4871

4872 4873
	return work;
}
L
Linus Torvalds 已提交
4874

4875 4876
/**
 * __napi_schedule - schedule for receive
4877
 * @n: entry to schedule
4878
 *
4879 4880
 * The entry's receive function will be scheduled to run.
 * Consider using __napi_schedule_irqoff() if hard irqs are masked.
4881
 */
H
Harvey Harrison 已提交
4882
void __napi_schedule(struct napi_struct *n)
4883 4884
{
	unsigned long flags;
L
Linus Torvalds 已提交
4885

4886
	local_irq_save(flags);
4887
	____napi_schedule(this_cpu_ptr(&softnet_data), n);
4888
	local_irq_restore(flags);
L
Linus Torvalds 已提交
4889
}
4890 4891
EXPORT_SYMBOL(__napi_schedule);

4892 4893 4894 4895 4896 4897 4898 4899 4900 4901 4902 4903
/**
 * __napi_schedule_irqoff - schedule for receive
 * @n: entry to schedule
 *
 * Variant of __napi_schedule() assuming hard irqs are masked
 */
void __napi_schedule_irqoff(struct napi_struct *n)
{
	____napi_schedule(this_cpu_ptr(&softnet_data), n);
}
EXPORT_SYMBOL(__napi_schedule_irqoff);

4904
bool __napi_complete(struct napi_struct *n)
4905 4906 4907
{
	BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));

4908 4909 4910 4911
	/* Some drivers call us directly, instead of calling
	 * napi_complete_done().
	 */
	if (unlikely(test_bit(NAPI_STATE_IN_BUSY_POLL, &n->state)))
4912
		return false;
4913

E
Eric Dumazet 已提交
4914
	list_del_init(&n->poll_list);
4915
	smp_mb__before_atomic();
4916
	clear_bit(NAPI_STATE_SCHED, &n->state);
4917
	return true;
4918 4919 4920
}
EXPORT_SYMBOL(__napi_complete);

4921
bool napi_complete_done(struct napi_struct *n, int work_done)
4922 4923 4924 4925
{
	unsigned long flags;

	/*
4926 4927 4928 4929
	 * 1) Don't let napi dequeue from the cpu poll list
	 *    just in case its running on a different cpu.
	 * 2) If we are busy polling, do nothing here, we have
	 *    the guarantee we will be called later.
4930
	 */
4931 4932
	if (unlikely(n->state & (NAPIF_STATE_NPSVC |
				 NAPIF_STATE_IN_BUSY_POLL)))
4933
		return false;
4934

4935 4936
	if (n->gro_list) {
		unsigned long timeout = 0;
E
Eric Dumazet 已提交
4937

4938 4939 4940 4941 4942 4943 4944 4945 4946
		if (work_done)
			timeout = n->dev->gro_flush_timeout;

		if (timeout)
			hrtimer_start(&n->timer, ns_to_ktime(timeout),
				      HRTIMER_MODE_REL_PINNED);
		else
			napi_gro_flush(n, false);
	}
E
Eric Dumazet 已提交
4947 4948 4949 4950 4951 4952 4953 4954
	if (likely(list_empty(&n->poll_list))) {
		WARN_ON_ONCE(!test_and_clear_bit(NAPI_STATE_SCHED, &n->state));
	} else {
		/* If n->poll_list is not empty, we need to mask irqs */
		local_irq_save(flags);
		__napi_complete(n);
		local_irq_restore(flags);
	}
4955
	return true;
4956
}
4957
EXPORT_SYMBOL(napi_complete_done);
4958

E
Eliezer Tamir 已提交
4959
/* must be called under rcu_read_lock(), as we dont take a reference */
E
Eric Dumazet 已提交
4960
static struct napi_struct *napi_by_id(unsigned int napi_id)
E
Eliezer Tamir 已提交
4961 4962 4963 4964 4965 4966 4967 4968 4969 4970
{
	unsigned int hash = napi_id % HASH_SIZE(napi_hash);
	struct napi_struct *napi;

	hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
		if (napi->napi_id == napi_id)
			return napi;

	return NULL;
}
E
Eric Dumazet 已提交
4971 4972

#if defined(CONFIG_NET_RX_BUSY_POLL)
4973

4974
#define BUSY_POLL_BUDGET 8
4975 4976 4977 4978 4979 4980 4981 4982 4983 4984 4985 4986 4987 4988 4989 4990 4991 4992 4993 4994 4995

static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock)
{
	int rc;

	clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);

	local_bh_disable();

	/* All we really want here is to re-enable device interrupts.
	 * Ideally, a new ndo_busy_poll_stop() could avoid another round.
	 */
	rc = napi->poll(napi, BUSY_POLL_BUDGET);
	netpoll_poll_unlock(have_poll_lock);
	if (rc == BUSY_POLL_BUDGET)
		__napi_schedule(napi);
	local_bh_enable();
	if (local_softirq_pending())
		do_softirq();
}

E
Eric Dumazet 已提交
4996 4997 4998
bool sk_busy_loop(struct sock *sk, int nonblock)
{
	unsigned long end_time = !nonblock ? sk_busy_loop_end_time(sk) : 0;
4999
	int (*napi_poll)(struct napi_struct *napi, int budget);
5000
	int (*busy_poll)(struct napi_struct *dev);
5001
	void *have_poll_lock = NULL;
E
Eric Dumazet 已提交
5002
	struct napi_struct *napi;
5003 5004 5005 5006 5007
	int rc;

restart:
	rc = false;
	napi_poll = NULL;
E
Eric Dumazet 已提交
5008

5009
	rcu_read_lock();
E
Eric Dumazet 已提交
5010 5011 5012 5013 5014

	napi = napi_by_id(sk->sk_napi_id);
	if (!napi)
		goto out;

5015 5016
	/* Note: ndo_busy_poll method is optional in linux-4.5 */
	busy_poll = napi->dev->netdev_ops->ndo_busy_poll;
E
Eric Dumazet 已提交
5017

5018 5019
	preempt_disable();
	for (;;) {
5020
		rc = 0;
5021
		local_bh_disable();
5022 5023
		if (busy_poll) {
			rc = busy_poll(napi);
5024
			goto count;
5025
		}
5026 5027 5028 5029 5030 5031 5032 5033 5034 5035 5036 5037 5038 5039 5040 5041 5042 5043 5044
		if (!napi_poll) {
			unsigned long val = READ_ONCE(napi->state);

			/* If multiple threads are competing for this napi,
			 * we avoid dirtying napi->state as much as we can.
			 */
			if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
				   NAPIF_STATE_IN_BUSY_POLL))
				goto count;
			if (cmpxchg(&napi->state, val,
				    val | NAPIF_STATE_IN_BUSY_POLL |
					  NAPIF_STATE_SCHED) != val)
				goto count;
			have_poll_lock = netpoll_poll_lock(napi);
			napi_poll = napi->poll;
		}
		rc = napi_poll(napi, BUSY_POLL_BUDGET);
		trace_napi_poll(napi, rc, BUSY_POLL_BUDGET);
count:
5045
		if (rc > 0)
5046 5047
			__NET_ADD_STATS(sock_net(sk),
					LINUX_MIB_BUSYPOLLRXPACKETS, rc);
5048
		local_bh_enable();
E
Eric Dumazet 已提交
5049 5050 5051 5052

		if (rc == LL_FLUSH_FAILED)
			break; /* permanent failure */

5053 5054 5055
		if (nonblock || !skb_queue_empty(&sk->sk_receive_queue) ||
		    busy_loop_timeout(end_time))
			break;
E
Eric Dumazet 已提交
5056

5057 5058 5059 5060 5061 5062 5063 5064 5065 5066 5067
		if (unlikely(need_resched())) {
			if (napi_poll)
				busy_poll_stop(napi, have_poll_lock);
			preempt_enable();
			rcu_read_unlock();
			cond_resched();
			rc = !skb_queue_empty(&sk->sk_receive_queue);
			if (rc || busy_loop_timeout(end_time))
				return rc;
			goto restart;
		}
5068
		cpu_relax();
5069 5070 5071 5072
	}
	if (napi_poll)
		busy_poll_stop(napi, have_poll_lock);
	preempt_enable();
E
Eric Dumazet 已提交
5073 5074
	rc = !skb_queue_empty(&sk->sk_receive_queue);
out:
5075
	rcu_read_unlock();
E
Eric Dumazet 已提交
5076 5077 5078 5079 5080
	return rc;
}
EXPORT_SYMBOL(sk_busy_loop);

#endif /* CONFIG_NET_RX_BUSY_POLL */
E
Eliezer Tamir 已提交
5081

5082
static void napi_hash_add(struct napi_struct *napi)
E
Eliezer Tamir 已提交
5083
{
E
Eric Dumazet 已提交
5084 5085
	if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state) ||
	    test_and_set_bit(NAPI_STATE_HASHED, &napi->state))
5086
		return;
E
Eliezer Tamir 已提交
5087

5088
	spin_lock(&napi_hash_lock);
E
Eliezer Tamir 已提交
5089

5090 5091 5092 5093 5094 5095
	/* 0..NR_CPUS+1 range is reserved for sender_cpu use */
	do {
		if (unlikely(++napi_gen_id < NR_CPUS + 1))
			napi_gen_id = NR_CPUS + 1;
	} while (napi_by_id(napi_gen_id));
	napi->napi_id = napi_gen_id;
E
Eliezer Tamir 已提交
5096

5097 5098
	hlist_add_head_rcu(&napi->napi_hash_node,
			   &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
E
Eliezer Tamir 已提交
5099

5100
	spin_unlock(&napi_hash_lock);
E
Eliezer Tamir 已提交
5101 5102 5103 5104 5105
}

/* Warning : caller is responsible to make sure rcu grace period
 * is respected before freeing memory containing @napi
 */
5106
bool napi_hash_del(struct napi_struct *napi)
E
Eliezer Tamir 已提交
5107
{
5108 5109
	bool rcu_sync_needed = false;

E
Eliezer Tamir 已提交
5110 5111
	spin_lock(&napi_hash_lock);

5112 5113
	if (test_and_clear_bit(NAPI_STATE_HASHED, &napi->state)) {
		rcu_sync_needed = true;
E
Eliezer Tamir 已提交
5114
		hlist_del_rcu(&napi->napi_hash_node);
5115
	}
E
Eliezer Tamir 已提交
5116
	spin_unlock(&napi_hash_lock);
5117
	return rcu_sync_needed;
E
Eliezer Tamir 已提交
5118 5119 5120
}
EXPORT_SYMBOL_GPL(napi_hash_del);

5121 5122 5123 5124 5125 5126 5127 5128 5129 5130 5131
static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
{
	struct napi_struct *napi;

	napi = container_of(timer, struct napi_struct, timer);
	if (napi->gro_list)
		napi_schedule(napi);

	return HRTIMER_NORESTART;
}

5132 5133 5134 5135
void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
		    int (*poll)(struct napi_struct *, int), int weight)
{
	INIT_LIST_HEAD(&napi->poll_list);
5136 5137
	hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
	napi->timer.function = napi_watchdog;
5138
	napi->gro_count = 0;
5139
	napi->gro_list = NULL;
H
Herbert Xu 已提交
5140
	napi->skb = NULL;
5141
	napi->poll = poll;
E
Eric Dumazet 已提交
5142 5143 5144
	if (weight > NAPI_POLL_WEIGHT)
		pr_err_once("netif_napi_add() called with weight %d on device %s\n",
			    weight, dev->name);
5145 5146 5147
	napi->weight = weight;
	list_add(&napi->dev_list, &dev->napi_list);
	napi->dev = dev;
H
Herbert Xu 已提交
5148
#ifdef CONFIG_NETPOLL
5149 5150 5151
	napi->poll_owner = -1;
#endif
	set_bit(NAPI_STATE_SCHED, &napi->state);
5152
	napi_hash_add(napi);
5153 5154 5155
}
EXPORT_SYMBOL(netif_napi_add);

5156 5157 5158 5159 5160 5161 5162
void napi_disable(struct napi_struct *n)
{
	might_sleep();
	set_bit(NAPI_STATE_DISABLE, &n->state);

	while (test_and_set_bit(NAPI_STATE_SCHED, &n->state))
		msleep(1);
5163 5164
	while (test_and_set_bit(NAPI_STATE_NPSVC, &n->state))
		msleep(1);
5165 5166 5167 5168 5169 5170 5171

	hrtimer_cancel(&n->timer);

	clear_bit(NAPI_STATE_DISABLE, &n->state);
}
EXPORT_SYMBOL(napi_disable);

5172
/* Must be called in process context */
5173 5174
void netif_napi_del(struct napi_struct *napi)
{
5175 5176 5177
	might_sleep();
	if (napi_hash_del(napi))
		synchronize_net();
5178
	list_del_init(&napi->dev_list);
5179
	napi_free_frags(napi);
5180

E
Eric Dumazet 已提交
5181
	kfree_skb_list(napi->gro_list);
5182
	napi->gro_list = NULL;
5183
	napi->gro_count = 0;
5184 5185 5186
}
EXPORT_SYMBOL(netif_napi_del);

5187 5188 5189 5190 5191 5192 5193 5194 5195 5196 5197 5198 5199 5200 5201 5202 5203 5204 5205 5206
static int napi_poll(struct napi_struct *n, struct list_head *repoll)
{
	void *have;
	int work, weight;

	list_del_init(&n->poll_list);

	have = netpoll_poll_lock(n);

	weight = n->weight;

	/* This NAPI_STATE_SCHED test is for avoiding a race
	 * with netpoll's poll_napi().  Only the entity which
	 * obtains the lock and sees NAPI_STATE_SCHED set will
	 * actually make the ->poll() call.  Therefore we avoid
	 * accidentally calling ->poll() when NAPI is not scheduled.
	 */
	work = 0;
	if (test_bit(NAPI_STATE_SCHED, &n->state)) {
		work = n->poll(n, weight);
5207
		trace_napi_poll(n, work, weight);
5208 5209 5210 5211 5212 5213 5214 5215 5216 5217 5218 5219 5220 5221 5222 5223 5224 5225 5226 5227 5228 5229 5230 5231
	}

	WARN_ON_ONCE(work > weight);

	if (likely(work < weight))
		goto out_unlock;

	/* Drivers must not modify the NAPI state if they
	 * consume the entire weight.  In such cases this code
	 * still "owns" the NAPI instance and therefore can
	 * move the instance around on the list at-will.
	 */
	if (unlikely(napi_disable_pending(n))) {
		napi_complete(n);
		goto out_unlock;
	}

	if (n->gro_list) {
		/* flush too old packets
		 * If HZ < 1000, flush all packets.
		 */
		napi_gro_flush(n, HZ >= 1000);
	}

5232 5233 5234 5235 5236 5237 5238 5239 5240
	/* Some drivers may have called napi_schedule
	 * prior to exhausting their budget.
	 */
	if (unlikely(!list_empty(&n->poll_list))) {
		pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
			     n->dev ? n->dev->name : "backlog");
		goto out_unlock;
	}

5241 5242 5243 5244 5245 5246 5247 5248
	list_add_tail(&n->poll_list, repoll);

out_unlock:
	netpoll_poll_unlock(have);

	return work;
}

5249
static __latent_entropy void net_rx_action(struct softirq_action *h)
L
Linus Torvalds 已提交
5250
{
5251
	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
5252
	unsigned long time_limit = jiffies + 2;
5253
	int budget = netdev_budget;
E
Eric Dumazet 已提交
5254 5255
	LIST_HEAD(list);
	LIST_HEAD(repoll);
5256

L
Linus Torvalds 已提交
5257
	local_irq_disable();
E
Eric Dumazet 已提交
5258 5259
	list_splice_init(&sd->poll_list, &list);
	local_irq_enable();
L
Linus Torvalds 已提交
5260

H
Herbert Xu 已提交
5261
	for (;;) {
5262
		struct napi_struct *n;
L
Linus Torvalds 已提交
5263

H
Herbert Xu 已提交
5264 5265
		if (list_empty(&list)) {
			if (!sd_has_rps_ipi_waiting(sd) && list_empty(&repoll))
5266
				goto out;
H
Herbert Xu 已提交
5267 5268 5269
			break;
		}

5270 5271 5272
		n = list_first_entry(&list, struct napi_struct, poll_list);
		budget -= napi_poll(n, &repoll);

E
Eric Dumazet 已提交
5273
		/* If softirq window is exhausted then punt.
5274 5275
		 * Allow this to run for 2 jiffies since which will allow
		 * an average latency of 1.5/HZ.
5276
		 */
H
Herbert Xu 已提交
5277 5278 5279 5280 5281
		if (unlikely(budget <= 0 ||
			     time_after_eq(jiffies, time_limit))) {
			sd->time_squeeze++;
			break;
		}
L
Linus Torvalds 已提交
5282
	}
E
Eric Dumazet 已提交
5283 5284 5285 5286 5287 5288 5289 5290 5291

	local_irq_disable();

	list_splice_tail_init(&sd->poll_list, &list);
	list_splice_tail(&repoll, &list);
	list_splice(&list, &sd->poll_list);
	if (!list_empty(&sd->poll_list))
		__raise_softirq_irqoff(NET_RX_SOFTIRQ);

5292
	net_rps_action_and_irq_enable(sd);
5293 5294
out:
	__kfree_skb_flush();
L
Linus Torvalds 已提交
5295 5296
}

5297
struct netdev_adjacent {
J
Jiri Pirko 已提交
5298
	struct net_device *dev;
5299 5300

	/* upper master flag, there can only be one master device per list */
J
Jiri Pirko 已提交
5301
	bool master;
5302 5303 5304 5305

	/* counter for the number of times this device was added to us */
	u16 ref_nr;

5306 5307 5308
	/* private field for the users */
	void *private;

J
Jiri Pirko 已提交
5309 5310 5311 5312
	struct list_head list;
	struct rcu_head rcu;
};

5313
static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
5314
						 struct list_head *adj_list)
J
Jiri Pirko 已提交
5315
{
5316 5317
	struct netdev_adjacent *adj;

5318
	list_for_each_entry(adj, adj_list, list) {
5319 5320
		if (adj->dev == adj_dev)
			return adj;
J
Jiri Pirko 已提交
5321 5322 5323 5324
	}
	return NULL;
}

5325 5326 5327 5328 5329 5330 5331
static int __netdev_has_upper_dev(struct net_device *upper_dev, void *data)
{
	struct net_device *dev = data;

	return upper_dev == dev;
}

J
Jiri Pirko 已提交
5332 5333 5334 5335 5336 5337 5338 5339 5340 5341 5342 5343 5344 5345
/**
 * netdev_has_upper_dev - Check if device is linked to an upper device
 * @dev: device
 * @upper_dev: upper device to check
 *
 * Find out if a device is linked to specified upper device and return true
 * in case it is. Note that this checks only immediate upper device,
 * not through a complete stack of devices. The caller must hold the RTNL lock.
 */
bool netdev_has_upper_dev(struct net_device *dev,
			  struct net_device *upper_dev)
{
	ASSERT_RTNL();

5346 5347
	return netdev_walk_all_upper_dev_rcu(dev, __netdev_has_upper_dev,
					     upper_dev);
J
Jiri Pirko 已提交
5348 5349 5350
}
EXPORT_SYMBOL(netdev_has_upper_dev);

5351 5352 5353 5354 5355 5356 5357 5358 5359 5360 5361 5362 5363 5364 5365 5366 5367 5368
/**
 * netdev_has_upper_dev_all - Check if device is linked to an upper device
 * @dev: device
 * @upper_dev: upper device to check
 *
 * Find out if a device is linked to specified upper device and return true
 * in case it is. Note that this checks the entire upper device chain.
 * The caller must hold rcu lock.
 */

bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
				  struct net_device *upper_dev)
{
	return !!netdev_walk_all_upper_dev_rcu(dev, __netdev_has_upper_dev,
					       upper_dev);
}
EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);

J
Jiri Pirko 已提交
5369 5370 5371 5372 5373 5374 5375
/**
 * netdev_has_any_upper_dev - Check if device is linked to some device
 * @dev: device
 *
 * Find out if a device is linked to an upper device and return true in case
 * it is. The caller must hold the RTNL lock.
 */
S
stephen hemminger 已提交
5376
static bool netdev_has_any_upper_dev(struct net_device *dev)
J
Jiri Pirko 已提交
5377 5378 5379
{
	ASSERT_RTNL();

5380
	return !list_empty(&dev->adj_list.upper);
J
Jiri Pirko 已提交
5381 5382 5383 5384 5385 5386 5387 5388 5389 5390 5391
}

/**
 * netdev_master_upper_dev_get - Get master upper device
 * @dev: device
 *
 * Find a master upper device and return pointer to it or NULL in case
 * it's not there. The caller must hold the RTNL lock.
 */
struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
{
5392
	struct netdev_adjacent *upper;
J
Jiri Pirko 已提交
5393 5394 5395

	ASSERT_RTNL();

5396
	if (list_empty(&dev->adj_list.upper))
J
Jiri Pirko 已提交
5397 5398
		return NULL;

5399
	upper = list_first_entry(&dev->adj_list.upper,
5400
				 struct netdev_adjacent, list);
J
Jiri Pirko 已提交
5401 5402 5403 5404 5405 5406
	if (likely(upper->master))
		return upper->dev;
	return NULL;
}
EXPORT_SYMBOL(netdev_master_upper_dev_get);

5407 5408 5409 5410 5411 5412 5413 5414 5415 5416 5417 5418 5419 5420
/**
 * netdev_has_any_lower_dev - Check if device is linked to some device
 * @dev: device
 *
 * Find out if a device is linked to a lower device and return true in case
 * it is. The caller must hold the RTNL lock.
 */
static bool netdev_has_any_lower_dev(struct net_device *dev)
{
	ASSERT_RTNL();

	return !list_empty(&dev->adj_list.lower);
}

5421 5422 5423 5424 5425 5426 5427 5428 5429 5430
void *netdev_adjacent_get_private(struct list_head *adj_list)
{
	struct netdev_adjacent *adj;

	adj = list_entry(adj_list, struct netdev_adjacent, list);

	return adj->private;
}
EXPORT_SYMBOL(netdev_adjacent_get_private);

5431 5432 5433 5434 5435 5436 5437 5438 5439 5440 5441 5442 5443 5444 5445 5446 5447 5448 5449 5450 5451 5452 5453 5454 5455 5456
/**
 * netdev_upper_get_next_dev_rcu - Get the next dev from upper list
 * @dev: device
 * @iter: list_head ** of the current position
 *
 * Gets the next device from the dev's upper list, starting from iter
 * position. The caller must hold RCU read lock.
 */
struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
						 struct list_head **iter)
{
	struct netdev_adjacent *upper;

	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());

	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);

	if (&upper->list == &dev->adj_list.upper)
		return NULL;

	*iter = &upper->list;

	return upper->dev;
}
EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);

5457 5458 5459 5460 5461 5462 5463 5464 5465 5466 5467 5468 5469 5470 5471 5472 5473 5474 5475 5476 5477 5478 5479 5480 5481 5482 5483 5484 5485 5486 5487 5488 5489 5490 5491 5492 5493 5494 5495 5496 5497 5498 5499 5500 5501
static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
						    struct list_head **iter)
{
	struct netdev_adjacent *upper;

	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());

	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);

	if (&upper->list == &dev->adj_list.upper)
		return NULL;

	*iter = &upper->list;

	return upper->dev;
}

int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
				  int (*fn)(struct net_device *dev,
					    void *data),
				  void *data)
{
	struct net_device *udev;
	struct list_head *iter;
	int ret;

	for (iter = &dev->adj_list.upper,
	     udev = netdev_next_upper_dev_rcu(dev, &iter);
	     udev;
	     udev = netdev_next_upper_dev_rcu(dev, &iter)) {
		/* first is the upper device itself */
		ret = fn(udev, data);
		if (ret)
			return ret;

		/* then look at all of its upper devices */
		ret = netdev_walk_all_upper_dev_rcu(udev, fn, data);
		if (ret)
			return ret;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);

5502 5503 5504 5505 5506 5507 5508 5509 5510
/**
 * netdev_lower_get_next_private - Get the next ->private from the
 *				   lower neighbour list
 * @dev: device
 * @iter: list_head ** of the current position
 *
 * Gets the next netdev_adjacent->private from the dev's lower neighbour
 * list, starting from iter position. The caller must hold either hold the
 * RTNL lock or its own locking that guarantees that the neighbour lower
5511
 * list will remain unchanged.
5512 5513 5514 5515 5516 5517 5518 5519 5520 5521 5522
 */
void *netdev_lower_get_next_private(struct net_device *dev,
				    struct list_head **iter)
{
	struct netdev_adjacent *lower;

	lower = list_entry(*iter, struct netdev_adjacent, list);

	if (&lower->list == &dev->adj_list.lower)
		return NULL;

5523
	*iter = lower->list.next;
5524 5525 5526 5527 5528 5529 5530 5531 5532 5533 5534 5535 5536 5537 5538 5539 5540 5541 5542 5543 5544 5545 5546 5547 5548 5549 5550

	return lower->private;
}
EXPORT_SYMBOL(netdev_lower_get_next_private);

/**
 * netdev_lower_get_next_private_rcu - Get the next ->private from the
 *				       lower neighbour list, RCU
 *				       variant
 * @dev: device
 * @iter: list_head ** of the current position
 *
 * Gets the next netdev_adjacent->private from the dev's lower neighbour
 * list, starting from iter position. The caller must hold RCU read lock.
 */
void *netdev_lower_get_next_private_rcu(struct net_device *dev,
					struct list_head **iter)
{
	struct netdev_adjacent *lower;

	WARN_ON_ONCE(!rcu_read_lock_held());

	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);

	if (&lower->list == &dev->adj_list.lower)
		return NULL;

5551
	*iter = &lower->list;
5552 5553 5554 5555 5556

	return lower->private;
}
EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);

5557 5558 5559 5560 5561 5562 5563 5564 5565
/**
 * netdev_lower_get_next - Get the next device from the lower neighbour
 *                         list
 * @dev: device
 * @iter: list_head ** of the current position
 *
 * Gets the next netdev_adjacent from the dev's lower neighbour
 * list, starting from iter position. The caller must hold RTNL lock or
 * its own locking that guarantees that the neighbour lower
5566
 * list will remain unchanged.
5567 5568 5569 5570 5571
 */
void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
{
	struct netdev_adjacent *lower;

5572
	lower = list_entry(*iter, struct netdev_adjacent, list);
5573 5574 5575 5576

	if (&lower->list == &dev->adj_list.lower)
		return NULL;

5577
	*iter = lower->list.next;
5578 5579 5580 5581 5582

	return lower->dev;
}
EXPORT_SYMBOL(netdev_lower_get_next);

5583 5584 5585 5586 5587
static struct net_device *netdev_next_lower_dev(struct net_device *dev,
						struct list_head **iter)
{
	struct netdev_adjacent *lower;

5588
	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
5589 5590 5591 5592

	if (&lower->list == &dev->adj_list.lower)
		return NULL;

5593
	*iter = &lower->list;
5594 5595 5596 5597 5598 5599 5600 5601 5602 5603 5604 5605 5606 5607 5608 5609 5610 5611 5612 5613 5614 5615 5616 5617 5618 5619 5620 5621 5622 5623 5624 5625 5626 5627 5628 5629 5630 5631 5632 5633 5634 5635 5636 5637 5638 5639 5640 5641 5642 5643 5644 5645 5646 5647 5648 5649 5650 5651 5652 5653 5654 5655 5656 5657 5658 5659 5660 5661 5662 5663 5664 5665 5666 5667

	return lower->dev;
}

int netdev_walk_all_lower_dev(struct net_device *dev,
			      int (*fn)(struct net_device *dev,
					void *data),
			      void *data)
{
	struct net_device *ldev;
	struct list_head *iter;
	int ret;

	for (iter = &dev->adj_list.lower,
	     ldev = netdev_next_lower_dev(dev, &iter);
	     ldev;
	     ldev = netdev_next_lower_dev(dev, &iter)) {
		/* first is the lower device itself */
		ret = fn(ldev, data);
		if (ret)
			return ret;

		/* then look at all of its lower devices */
		ret = netdev_walk_all_lower_dev(ldev, fn, data);
		if (ret)
			return ret;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);

static struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
						    struct list_head **iter)
{
	struct netdev_adjacent *lower;

	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
	if (&lower->list == &dev->adj_list.lower)
		return NULL;

	*iter = &lower->list;

	return lower->dev;
}

int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
				  int (*fn)(struct net_device *dev,
					    void *data),
				  void *data)
{
	struct net_device *ldev;
	struct list_head *iter;
	int ret;

	for (iter = &dev->adj_list.lower,
	     ldev = netdev_next_lower_dev_rcu(dev, &iter);
	     ldev;
	     ldev = netdev_next_lower_dev_rcu(dev, &iter)) {
		/* first is the lower device itself */
		ret = fn(ldev, data);
		if (ret)
			return ret;

		/* then look at all of its lower devices */
		ret = netdev_walk_all_lower_dev_rcu(ldev, fn, data);
		if (ret)
			return ret;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);

5668 5669 5670 5671 5672 5673 5674 5675 5676 5677 5678 5679 5680 5681 5682 5683 5684 5685 5686 5687 5688
/**
 * netdev_lower_get_first_private_rcu - Get the first ->private from the
 *				       lower neighbour list, RCU
 *				       variant
 * @dev: device
 *
 * Gets the first netdev_adjacent->private from the dev's lower neighbour
 * list. The caller must hold RCU read lock.
 */
void *netdev_lower_get_first_private_rcu(struct net_device *dev)
{
	struct netdev_adjacent *lower;

	lower = list_first_or_null_rcu(&dev->adj_list.lower,
			struct netdev_adjacent, list);
	if (lower)
		return lower->private;
	return NULL;
}
EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);

J
Jiri Pirko 已提交
5689 5690 5691 5692 5693 5694 5695 5696 5697
/**
 * netdev_master_upper_dev_get_rcu - Get master upper device
 * @dev: device
 *
 * Find a master upper device and return pointer to it or NULL in case
 * it's not there. The caller must hold the RCU read lock.
 */
struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
{
5698
	struct netdev_adjacent *upper;
J
Jiri Pirko 已提交
5699

5700
	upper = list_first_or_null_rcu(&dev->adj_list.upper,
5701
				       struct netdev_adjacent, list);
J
Jiri Pirko 已提交
5702 5703 5704 5705 5706 5707
	if (upper && likely(upper->master))
		return upper->dev;
	return NULL;
}
EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);

5708
static int netdev_adjacent_sysfs_add(struct net_device *dev,
5709 5710 5711 5712 5713 5714 5715 5716 5717
			      struct net_device *adj_dev,
			      struct list_head *dev_list)
{
	char linkname[IFNAMSIZ+7];
	sprintf(linkname, dev_list == &dev->adj_list.upper ?
		"upper_%s" : "lower_%s", adj_dev->name);
	return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
				 linkname);
}
5718
static void netdev_adjacent_sysfs_del(struct net_device *dev,
5719 5720 5721 5722 5723 5724 5725 5726 5727
			       char *name,
			       struct list_head *dev_list)
{
	char linkname[IFNAMSIZ+7];
	sprintf(linkname, dev_list == &dev->adj_list.upper ?
		"upper_%s" : "lower_%s", name);
	sysfs_remove_link(&(dev->dev.kobj), linkname);
}

5728 5729 5730 5731 5732 5733 5734 5735
static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
						 struct net_device *adj_dev,
						 struct list_head *dev_list)
{
	return (dev_list == &dev->adj_list.upper ||
		dev_list == &dev->adj_list.lower) &&
		net_eq(dev_net(dev), dev_net(adj_dev));
}
5736

5737 5738
static int __netdev_adjacent_dev_insert(struct net_device *dev,
					struct net_device *adj_dev,
5739
					struct list_head *dev_list,
5740
					void *private, bool master)
5741 5742
{
	struct netdev_adjacent *adj;
5743
	int ret;
5744

5745
	adj = __netdev_find_adj(adj_dev, dev_list);
5746 5747

	if (adj) {
5748
		adj->ref_nr += 1;
5749 5750 5751
		pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
			 dev->name, adj_dev->name, adj->ref_nr);

5752 5753 5754 5755 5756 5757 5758 5759 5760
		return 0;
	}

	adj = kmalloc(sizeof(*adj), GFP_KERNEL);
	if (!adj)
		return -ENOMEM;

	adj->dev = adj_dev;
	adj->master = master;
5761
	adj->ref_nr = 1;
5762
	adj->private = private;
5763
	dev_hold(adj_dev);
5764

5765 5766
	pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
		 dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
5767

5768
	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
5769
		ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
5770 5771 5772 5773
		if (ret)
			goto free_adj;
	}

5774
	/* Ensure that master link is always the first item in list. */
5775 5776 5777 5778
	if (master) {
		ret = sysfs_create_link(&(dev->dev.kobj),
					&(adj_dev->dev.kobj), "master");
		if (ret)
5779
			goto remove_symlinks;
5780

5781
		list_add_rcu(&adj->list, dev_list);
5782
	} else {
5783
		list_add_tail_rcu(&adj->list, dev_list);
5784
	}
5785 5786

	return 0;
5787

5788
remove_symlinks:
5789
	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
5790
		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
5791 5792
free_adj:
	kfree(adj);
5793
	dev_put(adj_dev);
5794 5795

	return ret;
5796 5797
}

S
stephen hemminger 已提交
5798 5799
static void __netdev_adjacent_dev_remove(struct net_device *dev,
					 struct net_device *adj_dev,
5800
					 u16 ref_nr,
S
stephen hemminger 已提交
5801
					 struct list_head *dev_list)
5802 5803 5804
{
	struct netdev_adjacent *adj;

5805 5806 5807
	pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
		 dev->name, adj_dev->name, ref_nr);

5808
	adj = __netdev_find_adj(adj_dev, dev_list);
5809

5810
	if (!adj) {
5811
		pr_err("Adjacency does not exist for device %s from %s\n",
5812
		       dev->name, adj_dev->name);
5813 5814
		WARN_ON(1);
		return;
5815
	}
5816

5817
	if (adj->ref_nr > ref_nr) {
5818 5819 5820
		pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
			 dev->name, adj_dev->name, ref_nr,
			 adj->ref_nr - ref_nr);
5821
		adj->ref_nr -= ref_nr;
5822 5823 5824
		return;
	}

5825 5826 5827
	if (adj->master)
		sysfs_remove_link(&(dev->dev.kobj), "master");

5828
	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
5829
		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
5830

5831
	list_del_rcu(&adj->list);
5832
	pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
5833
		 adj_dev->name, dev->name, adj_dev->name);
5834 5835 5836 5837
	dev_put(adj_dev);
	kfree_rcu(adj, rcu);
}

S
stephen hemminger 已提交
5838 5839 5840 5841 5842
static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
					    struct net_device *upper_dev,
					    struct list_head *up_list,
					    struct list_head *down_list,
					    void *private, bool master)
5843 5844 5845
{
	int ret;

5846
	ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
5847
					   private, master);
5848 5849 5850
	if (ret)
		return ret;

5851
	ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
5852
					   private, false);
5853
	if (ret) {
5854
		__netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
5855 5856 5857 5858 5859 5860
		return ret;
	}

	return 0;
}

S
stephen hemminger 已提交
5861 5862
static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
					       struct net_device *upper_dev,
5863
					       u16 ref_nr,
S
stephen hemminger 已提交
5864 5865
					       struct list_head *up_list,
					       struct list_head *down_list)
5866
{
5867 5868
	__netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
	__netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
5869 5870
}

S
stephen hemminger 已提交
5871 5872 5873
static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
						struct net_device *upper_dev,
						void *private, bool master)
5874
{
5875 5876 5877 5878
	return __netdev_adjacent_dev_link_lists(dev, upper_dev,
						&dev->adj_list.upper,
						&upper_dev->adj_list.lower,
						private, master);
5879 5880
}

S
stephen hemminger 已提交
5881 5882
static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
						   struct net_device *upper_dev)
5883
{
5884
	__netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
5885 5886 5887
					   &dev->adj_list.upper,
					   &upper_dev->adj_list.lower);
}
5888

J
Jiri Pirko 已提交
5889
static int __netdev_upper_dev_link(struct net_device *dev,
5890
				   struct net_device *upper_dev, bool master,
5891
				   void *upper_priv, void *upper_info)
J
Jiri Pirko 已提交
5892
{
5893
	struct netdev_notifier_changeupper_info changeupper_info;
5894
	int ret = 0;
J
Jiri Pirko 已提交
5895 5896 5897 5898 5899 5900 5901

	ASSERT_RTNL();

	if (dev == upper_dev)
		return -EBUSY;

	/* To prevent loops, check if dev is not upper device to upper_dev. */
5902
	if (netdev_has_upper_dev(upper_dev, dev))
J
Jiri Pirko 已提交
5903 5904
		return -EBUSY;

5905
	if (netdev_has_upper_dev(dev, upper_dev))
J
Jiri Pirko 已提交
5906 5907 5908 5909 5910
		return -EEXIST;

	if (master && netdev_master_upper_dev_get(dev))
		return -EBUSY;

5911 5912 5913
	changeupper_info.upper_dev = upper_dev;
	changeupper_info.master = master;
	changeupper_info.linking = true;
5914
	changeupper_info.upper_info = upper_info;
5915

5916 5917 5918 5919 5920 5921
	ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER, dev,
					    &changeupper_info.info);
	ret = notifier_to_errno(ret);
	if (ret)
		return ret;

5922
	ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
5923
						   master);
5924 5925
	if (ret)
		return ret;
J
Jiri Pirko 已提交
5926

5927 5928 5929 5930
	ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER, dev,
					    &changeupper_info.info);
	ret = notifier_to_errno(ret);
	if (ret)
5931
		goto rollback;
5932

J
Jiri Pirko 已提交
5933
	return 0;
5934

5935
rollback:
5936
	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
5937 5938

	return ret;
J
Jiri Pirko 已提交
5939 5940 5941 5942 5943 5944 5945 5946 5947 5948 5949 5950 5951 5952 5953
}

/**
 * netdev_upper_dev_link - Add a link to the upper device
 * @dev: device
 * @upper_dev: new upper device
 *
 * Adds a link to device which is upper to this one. The caller must hold
 * the RTNL lock. On a failure a negative errno code is returned.
 * On success the reference counts are adjusted and the function
 * returns zero.
 */
int netdev_upper_dev_link(struct net_device *dev,
			  struct net_device *upper_dev)
{
5954
	return __netdev_upper_dev_link(dev, upper_dev, false, NULL, NULL);
J
Jiri Pirko 已提交
5955 5956 5957 5958 5959 5960 5961
}
EXPORT_SYMBOL(netdev_upper_dev_link);

/**
 * netdev_master_upper_dev_link - Add a master link to the upper device
 * @dev: device
 * @upper_dev: new upper device
5962
 * @upper_priv: upper device private
5963
 * @upper_info: upper info to be passed down via notifier
J
Jiri Pirko 已提交
5964 5965 5966 5967 5968 5969 5970 5971
 *
 * Adds a link to device which is upper to this one. In this case, only
 * one master upper device can be linked, although other non-master devices
 * might be linked as well. The caller must hold the RTNL lock.
 * On a failure a negative errno code is returned. On success the reference
 * counts are adjusted and the function returns zero.
 */
int netdev_master_upper_dev_link(struct net_device *dev,
5972
				 struct net_device *upper_dev,
5973
				 void *upper_priv, void *upper_info)
J
Jiri Pirko 已提交
5974
{
5975 5976
	return __netdev_upper_dev_link(dev, upper_dev, true,
				       upper_priv, upper_info);
J
Jiri Pirko 已提交
5977 5978 5979 5980 5981 5982 5983 5984 5985 5986 5987 5988 5989 5990
}
EXPORT_SYMBOL(netdev_master_upper_dev_link);

/**
 * netdev_upper_dev_unlink - Removes a link to upper device
 * @dev: device
 * @upper_dev: new upper device
 *
 * Removes a link to device which is upper to this one. The caller must hold
 * the RTNL lock.
 */
void netdev_upper_dev_unlink(struct net_device *dev,
			     struct net_device *upper_dev)
{
5991
	struct netdev_notifier_changeupper_info changeupper_info;
J
Jiri Pirko 已提交
5992 5993
	ASSERT_RTNL();

5994 5995 5996 5997
	changeupper_info.upper_dev = upper_dev;
	changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
	changeupper_info.linking = false;

5998 5999 6000
	call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER, dev,
				      &changeupper_info.info);

6001
	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
6002

6003 6004
	call_netdevice_notifiers_info(NETDEV_CHANGEUPPER, dev,
				      &changeupper_info.info);
J
Jiri Pirko 已提交
6005 6006 6007
}
EXPORT_SYMBOL(netdev_upper_dev_unlink);

6008 6009 6010
/**
 * netdev_bonding_info_change - Dispatch event about slave change
 * @dev: device
6011
 * @bonding_info: info to dispatch
6012 6013 6014 6015 6016 6017 6018 6019 6020 6021 6022 6023 6024 6025 6026 6027
 *
 * Send NETDEV_BONDING_INFO to netdev notifiers with info.
 * The caller must hold the RTNL lock.
 */
void netdev_bonding_info_change(struct net_device *dev,
				struct netdev_bonding_info *bonding_info)
{
	struct netdev_notifier_bonding_info	info;

	memcpy(&info.bonding_info, bonding_info,
	       sizeof(struct netdev_bonding_info));
	call_netdevice_notifiers_info(NETDEV_BONDING_INFO, dev,
				      &info.info);
}
EXPORT_SYMBOL(netdev_bonding_info_change);

E
Eric Dumazet 已提交
6028
static void netdev_adjacent_add_links(struct net_device *dev)
6029 6030 6031 6032 6033 6034
{
	struct netdev_adjacent *iter;

	struct net *net = dev_net(dev);

	list_for_each_entry(iter, &dev->adj_list.upper, list) {
W
Wei Tang 已提交
6035
		if (!net_eq(net, dev_net(iter->dev)))
6036 6037 6038 6039 6040 6041 6042 6043
			continue;
		netdev_adjacent_sysfs_add(iter->dev, dev,
					  &iter->dev->adj_list.lower);
		netdev_adjacent_sysfs_add(dev, iter->dev,
					  &dev->adj_list.upper);
	}

	list_for_each_entry(iter, &dev->adj_list.lower, list) {
W
Wei Tang 已提交
6044
		if (!net_eq(net, dev_net(iter->dev)))
6045 6046 6047 6048 6049 6050 6051 6052
			continue;
		netdev_adjacent_sysfs_add(iter->dev, dev,
					  &iter->dev->adj_list.upper);
		netdev_adjacent_sysfs_add(dev, iter->dev,
					  &dev->adj_list.lower);
	}
}

E
Eric Dumazet 已提交
6053
static void netdev_adjacent_del_links(struct net_device *dev)
6054 6055 6056 6057 6058 6059
{
	struct netdev_adjacent *iter;

	struct net *net = dev_net(dev);

	list_for_each_entry(iter, &dev->adj_list.upper, list) {
W
Wei Tang 已提交
6060
		if (!net_eq(net, dev_net(iter->dev)))
6061 6062 6063 6064 6065 6066 6067 6068
			continue;
		netdev_adjacent_sysfs_del(iter->dev, dev->name,
					  &iter->dev->adj_list.lower);
		netdev_adjacent_sysfs_del(dev, iter->dev->name,
					  &dev->adj_list.upper);
	}

	list_for_each_entry(iter, &dev->adj_list.lower, list) {
W
Wei Tang 已提交
6069
		if (!net_eq(net, dev_net(iter->dev)))
6070 6071 6072 6073 6074 6075 6076 6077
			continue;
		netdev_adjacent_sysfs_del(iter->dev, dev->name,
					  &iter->dev->adj_list.upper);
		netdev_adjacent_sysfs_del(dev, iter->dev->name,
					  &dev->adj_list.lower);
	}
}

6078
void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
6079
{
6080
	struct netdev_adjacent *iter;
6081

6082 6083
	struct net *net = dev_net(dev);

6084
	list_for_each_entry(iter, &dev->adj_list.upper, list) {
W
Wei Tang 已提交
6085
		if (!net_eq(net, dev_net(iter->dev)))
6086
			continue;
6087 6088 6089 6090 6091
		netdev_adjacent_sysfs_del(iter->dev, oldname,
					  &iter->dev->adj_list.lower);
		netdev_adjacent_sysfs_add(iter->dev, dev,
					  &iter->dev->adj_list.lower);
	}
6092

6093
	list_for_each_entry(iter, &dev->adj_list.lower, list) {
W
Wei Tang 已提交
6094
		if (!net_eq(net, dev_net(iter->dev)))
6095
			continue;
6096 6097 6098 6099 6100
		netdev_adjacent_sysfs_del(iter->dev, oldname,
					  &iter->dev->adj_list.upper);
		netdev_adjacent_sysfs_add(iter->dev, dev,
					  &iter->dev->adj_list.upper);
	}
6101 6102 6103 6104 6105 6106 6107 6108 6109
}

void *netdev_lower_dev_get_private(struct net_device *dev,
				   struct net_device *lower_dev)
{
	struct netdev_adjacent *lower;

	if (!lower_dev)
		return NULL;
6110
	lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
6111 6112 6113 6114 6115 6116 6117
	if (!lower)
		return NULL;

	return lower->private;
}
EXPORT_SYMBOL(netdev_lower_dev_get_private);

6118

6119
int dev_get_nest_level(struct net_device *dev)
6120 6121 6122 6123 6124 6125 6126 6127 6128
{
	struct net_device *lower = NULL;
	struct list_head *iter;
	int max_nest = -1;
	int nest;

	ASSERT_RTNL();

	netdev_for_each_lower_dev(dev, lower, iter) {
6129
		nest = dev_get_nest_level(lower);
6130 6131 6132 6133
		if (max_nest < nest)
			max_nest = nest;
	}

6134
	return max_nest + 1;
6135 6136 6137
}
EXPORT_SYMBOL(dev_get_nest_level);

6138 6139 6140 6141 6142 6143 6144 6145 6146 6147 6148 6149 6150 6151 6152 6153 6154 6155 6156 6157
/**
 * netdev_lower_change - Dispatch event about lower device state change
 * @lower_dev: device
 * @lower_state_info: state to dispatch
 *
 * Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
 * The caller must hold the RTNL lock.
 */
void netdev_lower_state_changed(struct net_device *lower_dev,
				void *lower_state_info)
{
	struct netdev_notifier_changelowerstate_info changelowerstate_info;

	ASSERT_RTNL();
	changelowerstate_info.lower_state_info = lower_state_info;
	call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE, lower_dev,
				      &changelowerstate_info.info);
}
EXPORT_SYMBOL(netdev_lower_state_changed);

6158 6159 6160 6161 6162 6163 6164 6165 6166 6167 6168 6169 6170 6171 6172 6173 6174 6175 6176 6177 6178 6179 6180 6181 6182 6183 6184 6185 6186 6187 6188 6189 6190 6191 6192 6193 6194 6195 6196 6197 6198 6199 6200 6201
int netdev_default_l2upper_neigh_construct(struct net_device *dev,
					   struct neighbour *n)
{
	struct net_device *lower_dev, *stop_dev;
	struct list_head *iter;
	int err;

	netdev_for_each_lower_dev(dev, lower_dev, iter) {
		if (!lower_dev->netdev_ops->ndo_neigh_construct)
			continue;
		err = lower_dev->netdev_ops->ndo_neigh_construct(lower_dev, n);
		if (err) {
			stop_dev = lower_dev;
			goto rollback;
		}
	}
	return 0;

rollback:
	netdev_for_each_lower_dev(dev, lower_dev, iter) {
		if (lower_dev == stop_dev)
			break;
		if (!lower_dev->netdev_ops->ndo_neigh_destroy)
			continue;
		lower_dev->netdev_ops->ndo_neigh_destroy(lower_dev, n);
	}
	return err;
}
EXPORT_SYMBOL_GPL(netdev_default_l2upper_neigh_construct);

void netdev_default_l2upper_neigh_destroy(struct net_device *dev,
					  struct neighbour *n)
{
	struct net_device *lower_dev;
	struct list_head *iter;

	netdev_for_each_lower_dev(dev, lower_dev, iter) {
		if (!lower_dev->netdev_ops->ndo_neigh_destroy)
			continue;
		lower_dev->netdev_ops->ndo_neigh_destroy(lower_dev, n);
	}
}
EXPORT_SYMBOL_GPL(netdev_default_l2upper_neigh_destroy);

6202 6203
static void dev_change_rx_flags(struct net_device *dev, int flags)
{
6204 6205
	const struct net_device_ops *ops = dev->netdev_ops;

6206
	if (ops->ndo_change_rx_flags)
6207
		ops->ndo_change_rx_flags(dev, flags);
6208 6209
}

6210
static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
L
Linus Torvalds 已提交
6211
{
6212
	unsigned int old_flags = dev->flags;
6213 6214
	kuid_t uid;
	kgid_t gid;
L
Linus Torvalds 已提交
6215

6216 6217
	ASSERT_RTNL();

6218 6219 6220 6221 6222 6223 6224 6225 6226 6227 6228
	dev->flags |= IFF_PROMISC;
	dev->promiscuity += inc;
	if (dev->promiscuity == 0) {
		/*
		 * Avoid overflow.
		 * If inc causes overflow, untouch promisc and return error.
		 */
		if (inc < 0)
			dev->flags &= ~IFF_PROMISC;
		else {
			dev->promiscuity -= inc;
6229 6230
			pr_warn("%s: promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n",
				dev->name);
6231 6232 6233
			return -EOVERFLOW;
		}
	}
6234
	if (dev->flags != old_flags) {
6235 6236 6237
		pr_info("device %s %s promiscuous mode\n",
			dev->name,
			dev->flags & IFF_PROMISC ? "entered" : "left");
6238 6239
		if (audit_enabled) {
			current_uid_gid(&uid, &gid);
6240 6241 6242 6243 6244
			audit_log(current->audit_context, GFP_ATOMIC,
				AUDIT_ANOM_PROMISCUOUS,
				"dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
				dev->name, (dev->flags & IFF_PROMISC),
				(old_flags & IFF_PROMISC),
6245
				from_kuid(&init_user_ns, audit_get_loginuid(current)),
6246 6247
				from_kuid(&init_user_ns, uid),
				from_kgid(&init_user_ns, gid),
6248
				audit_get_sessionid(current));
6249
		}
6250

6251
		dev_change_rx_flags(dev, IFF_PROMISC);
L
Linus Torvalds 已提交
6252
	}
6253 6254
	if (notify)
		__dev_notify_flags(dev, old_flags, IFF_PROMISC);
6255
	return 0;
L
Linus Torvalds 已提交
6256 6257
}

6258 6259 6260 6261 6262 6263 6264 6265 6266
/**
 *	dev_set_promiscuity	- update promiscuity count on a device
 *	@dev: device
 *	@inc: modifier
 *
 *	Add or remove promiscuity from a device. While the count in the device
 *	remains above zero the interface remains promiscuous. Once it hits zero
 *	the device reverts back to normal filtering operation. A negative inc
 *	value is used to drop promiscuity on the device.
6267
 *	Return 0 if successful or a negative errno code on error.
6268
 */
6269
int dev_set_promiscuity(struct net_device *dev, int inc)
6270
{
6271
	unsigned int old_flags = dev->flags;
6272
	int err;
6273

6274
	err = __dev_set_promiscuity(dev, inc, true);
6275
	if (err < 0)
6276
		return err;
6277 6278
	if (dev->flags != old_flags)
		dev_set_rx_mode(dev);
6279
	return err;
6280
}
E
Eric Dumazet 已提交
6281
EXPORT_SYMBOL(dev_set_promiscuity);
6282

6283
static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
L
Linus Torvalds 已提交
6284
{
6285
	unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
L
Linus Torvalds 已提交
6286

6287 6288
	ASSERT_RTNL();

L
Linus Torvalds 已提交
6289
	dev->flags |= IFF_ALLMULTI;
6290 6291 6292 6293 6294 6295 6296 6297 6298 6299
	dev->allmulti += inc;
	if (dev->allmulti == 0) {
		/*
		 * Avoid overflow.
		 * If inc causes overflow, untouch allmulti and return error.
		 */
		if (inc < 0)
			dev->flags &= ~IFF_ALLMULTI;
		else {
			dev->allmulti -= inc;
6300 6301
			pr_warn("%s: allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n",
				dev->name);
6302 6303 6304
			return -EOVERFLOW;
		}
	}
6305
	if (dev->flags ^ old_flags) {
6306
		dev_change_rx_flags(dev, IFF_ALLMULTI);
6307
		dev_set_rx_mode(dev);
6308 6309 6310
		if (notify)
			__dev_notify_flags(dev, old_flags,
					   dev->gflags ^ old_gflags);
6311
	}
6312
	return 0;
6313
}
6314 6315 6316 6317 6318 6319 6320 6321 6322 6323 6324 6325 6326 6327 6328 6329 6330 6331

/**
 *	dev_set_allmulti	- update allmulti count on a device
 *	@dev: device
 *	@inc: modifier
 *
 *	Add or remove reception of all multicast frames to a device. While the
 *	count in the device remains above zero the interface remains listening
 *	to all interfaces. Once it hits zero the device reverts back to normal
 *	filtering operation. A negative @inc value is used to drop the counter
 *	when releasing a resource needing all multicasts.
 *	Return 0 if successful or a negative errno code on error.
 */

int dev_set_allmulti(struct net_device *dev, int inc)
{
	return __dev_set_allmulti(dev, inc, true);
}
E
Eric Dumazet 已提交
6332
EXPORT_SYMBOL(dev_set_allmulti);
6333 6334 6335 6336

/*
 *	Upload unicast and multicast address lists to device and
 *	configure RX filtering. When the device doesn't support unicast
J
Joe Perches 已提交
6337
 *	filtering it is put in promiscuous mode while unicast addresses
6338 6339 6340 6341
 *	are present.
 */
void __dev_set_rx_mode(struct net_device *dev)
{
6342 6343
	const struct net_device_ops *ops = dev->netdev_ops;

6344 6345 6346 6347 6348
	/* dev_open will call this function so the list will stay sane. */
	if (!(dev->flags&IFF_UP))
		return;

	if (!netif_device_present(dev))
6349
		return;
6350

6351
	if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
6352 6353 6354
		/* Unicast addresses changes may only happen under the rtnl,
		 * therefore calling __dev_set_promiscuity here is safe.
		 */
6355
		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
6356
			__dev_set_promiscuity(dev, 1, false);
6357
			dev->uc_promisc = true;
6358
		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
6359
			__dev_set_promiscuity(dev, -1, false);
6360
			dev->uc_promisc = false;
6361 6362
		}
	}
6363 6364 6365

	if (ops->ndo_set_rx_mode)
		ops->ndo_set_rx_mode(dev);
6366 6367 6368 6369
}

void dev_set_rx_mode(struct net_device *dev)
{
6370
	netif_addr_lock_bh(dev);
6371
	__dev_set_rx_mode(dev);
6372
	netif_addr_unlock_bh(dev);
L
Linus Torvalds 已提交
6373 6374
}

6375 6376 6377 6378 6379 6380
/**
 *	dev_get_flags - get flags reported to userspace
 *	@dev: device
 *
 *	Get the combination of flag bits exported through APIs to userspace.
 */
6381
unsigned int dev_get_flags(const struct net_device *dev)
L
Linus Torvalds 已提交
6382
{
6383
	unsigned int flags;
L
Linus Torvalds 已提交
6384 6385 6386

	flags = (dev->flags & ~(IFF_PROMISC |
				IFF_ALLMULTI |
S
Stefan Rompf 已提交
6387 6388 6389
				IFF_RUNNING |
				IFF_LOWER_UP |
				IFF_DORMANT)) |
L
Linus Torvalds 已提交
6390 6391 6392
		(dev->gflags & (IFF_PROMISC |
				IFF_ALLMULTI));

S
Stefan Rompf 已提交
6393 6394 6395 6396 6397 6398 6399 6400
	if (netif_running(dev)) {
		if (netif_oper_up(dev))
			flags |= IFF_RUNNING;
		if (netif_carrier_ok(dev))
			flags |= IFF_LOWER_UP;
		if (netif_dormant(dev))
			flags |= IFF_DORMANT;
	}
L
Linus Torvalds 已提交
6401 6402 6403

	return flags;
}
E
Eric Dumazet 已提交
6404
EXPORT_SYMBOL(dev_get_flags);
L
Linus Torvalds 已提交
6405

6406
int __dev_change_flags(struct net_device *dev, unsigned int flags)
L
Linus Torvalds 已提交
6407
{
6408
	unsigned int old_flags = dev->flags;
6409
	int ret;
L
Linus Torvalds 已提交
6410

6411 6412
	ASSERT_RTNL();

L
Linus Torvalds 已提交
6413 6414 6415 6416 6417 6418 6419 6420 6421 6422 6423 6424 6425 6426
	/*
	 *	Set the flags on our device.
	 */

	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
			       IFF_AUTOMEDIA)) |
		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
				    IFF_ALLMULTI));

	/*
	 *	Load in the correct multicast list now the flags have changed.
	 */

6427 6428
	if ((old_flags ^ flags) & IFF_MULTICAST)
		dev_change_rx_flags(dev, IFF_MULTICAST);
6429

6430
	dev_set_rx_mode(dev);
L
Linus Torvalds 已提交
6431 6432 6433 6434 6435 6436 6437 6438

	/*
	 *	Have we downed the interface. We handle IFF_UP ourselves
	 *	according to user attempts to set it, rather than blindly
	 *	setting it.
	 */

	ret = 0;
6439
	if ((old_flags ^ flags) & IFF_UP)
6440
		ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev);
L
Linus Torvalds 已提交
6441 6442

	if ((flags ^ dev->gflags) & IFF_PROMISC) {
E
Eric Dumazet 已提交
6443
		int inc = (flags & IFF_PROMISC) ? 1 : -1;
6444
		unsigned int old_flags = dev->flags;
E
Eric Dumazet 已提交
6445

L
Linus Torvalds 已提交
6446
		dev->gflags ^= IFF_PROMISC;
6447 6448 6449 6450

		if (__dev_set_promiscuity(dev, inc, false) >= 0)
			if (dev->flags != old_flags)
				dev_set_rx_mode(dev);
L
Linus Torvalds 已提交
6451 6452 6453 6454 6455 6456 6457
	}

	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
	   is important. Some (broken) drivers set IFF_PROMISC, when
	   IFF_ALLMULTI is requested not asking us and not reporting.
	 */
	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
E
Eric Dumazet 已提交
6458 6459
		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;

L
Linus Torvalds 已提交
6460
		dev->gflags ^= IFF_ALLMULTI;
6461
		__dev_set_allmulti(dev, inc, false);
L
Linus Torvalds 已提交
6462 6463
	}

6464 6465 6466
	return ret;
}

6467 6468
void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
			unsigned int gchanges)
6469 6470 6471
{
	unsigned int changes = dev->flags ^ old_flags;

6472
	if (gchanges)
6473
		rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC);
6474

6475 6476 6477 6478 6479 6480 6481 6482
	if (changes & IFF_UP) {
		if (dev->flags & IFF_UP)
			call_netdevice_notifiers(NETDEV_UP, dev);
		else
			call_netdevice_notifiers(NETDEV_DOWN, dev);
	}

	if (dev->flags & IFF_UP &&
6483 6484 6485 6486 6487 6488 6489
	    (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
		struct netdev_notifier_change_info change_info;

		change_info.flags_changed = changes;
		call_netdevice_notifiers_info(NETDEV_CHANGE, dev,
					      &change_info.info);
	}
6490 6491 6492 6493 6494 6495 6496 6497 6498 6499
}

/**
 *	dev_change_flags - change device settings
 *	@dev: device
 *	@flags: device state flags
 *
 *	Change settings on device based state flags. The flags are
 *	in the userspace exported format.
 */
6500
int dev_change_flags(struct net_device *dev, unsigned int flags)
6501
{
6502
	int ret;
6503
	unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
6504 6505 6506 6507 6508

	ret = __dev_change_flags(dev, flags);
	if (ret < 0)
		return ret;

6509
	changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
6510
	__dev_notify_flags(dev, old_flags, changes);
L
Linus Torvalds 已提交
6511 6512
	return ret;
}
E
Eric Dumazet 已提交
6513
EXPORT_SYMBOL(dev_change_flags);
L
Linus Torvalds 已提交
6514

6515 6516 6517 6518 6519 6520 6521 6522 6523 6524 6525
static int __dev_set_mtu(struct net_device *dev, int new_mtu)
{
	const struct net_device_ops *ops = dev->netdev_ops;

	if (ops->ndo_change_mtu)
		return ops->ndo_change_mtu(dev, new_mtu);

	dev->mtu = new_mtu;
	return 0;
}

6526 6527 6528 6529 6530 6531 6532
/**
 *	dev_set_mtu - Change maximum transfer unit
 *	@dev: device
 *	@new_mtu: new transfer unit
 *
 *	Change the maximum transfer size of the network device.
 */
L
Linus Torvalds 已提交
6533 6534
int dev_set_mtu(struct net_device *dev, int new_mtu)
{
6535
	int err, orig_mtu;
L
Linus Torvalds 已提交
6536 6537 6538 6539

	if (new_mtu == dev->mtu)
		return 0;

6540 6541 6542 6543
	/* MTU must be positive, and in range */
	if (new_mtu < 0 || new_mtu < dev->min_mtu) {
		net_err_ratelimited("%s: Invalid MTU %d requested, hw min %d\n",
				    dev->name, new_mtu, dev->min_mtu);
L
Linus Torvalds 已提交
6544
		return -EINVAL;
6545 6546 6547 6548
	}

	if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
		net_err_ratelimited("%s: Invalid MTU %d requested, hw max %d\n",
6549
				    dev->name, new_mtu, dev->max_mtu);
6550 6551
		return -EINVAL;
	}
L
Linus Torvalds 已提交
6552 6553 6554 6555

	if (!netif_device_present(dev))
		return -ENODEV;

6556 6557 6558 6559
	err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
	err = notifier_to_errno(err);
	if (err)
		return err;
6560

6561 6562
	orig_mtu = dev->mtu;
	err = __dev_set_mtu(dev, new_mtu);
6563

6564 6565 6566 6567 6568 6569 6570 6571 6572 6573 6574
	if (!err) {
		err = call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
		err = notifier_to_errno(err);
		if (err) {
			/* setting mtu back and notifying everyone again,
			 * so that they have a chance to revert changes.
			 */
			__dev_set_mtu(dev, orig_mtu);
			call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
		}
	}
L
Linus Torvalds 已提交
6575 6576
	return err;
}
E
Eric Dumazet 已提交
6577
EXPORT_SYMBOL(dev_set_mtu);
L
Linus Torvalds 已提交
6578

6579 6580 6581 6582 6583 6584 6585 6586 6587 6588 6589
/**
 *	dev_set_group - Change group this device belongs to
 *	@dev: device
 *	@new_group: group this device should belong to
 */
void dev_set_group(struct net_device *dev, int new_group)
{
	dev->group = new_group;
}
EXPORT_SYMBOL(dev_set_group);

6590 6591 6592 6593 6594 6595 6596
/**
 *	dev_set_mac_address - Change Media Access Control Address
 *	@dev: device
 *	@sa: new address
 *
 *	Change the hardware (MAC) address of the device
 */
L
Linus Torvalds 已提交
6597 6598
int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
{
6599
	const struct net_device_ops *ops = dev->netdev_ops;
L
Linus Torvalds 已提交
6600 6601
	int err;

6602
	if (!ops->ndo_set_mac_address)
L
Linus Torvalds 已提交
6603 6604 6605 6606 6607
		return -EOPNOTSUPP;
	if (sa->sa_family != dev->type)
		return -EINVAL;
	if (!netif_device_present(dev))
		return -ENODEV;
6608
	err = ops->ndo_set_mac_address(dev, sa);
6609 6610
	if (err)
		return err;
J
Jiri Pirko 已提交
6611
	dev->addr_assign_type = NET_ADDR_SET;
6612
	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
6613
	add_device_randomness(dev->dev_addr, dev->addr_len);
6614
	return 0;
L
Linus Torvalds 已提交
6615
}
E
Eric Dumazet 已提交
6616
EXPORT_SYMBOL(dev_set_mac_address);
L
Linus Torvalds 已提交
6617

J
Jiri Pirko 已提交
6618 6619 6620
/**
 *	dev_change_carrier - Change device carrier
 *	@dev: device
6621
 *	@new_carrier: new value
J
Jiri Pirko 已提交
6622 6623 6624 6625 6626 6627 6628 6629 6630 6631 6632 6633 6634 6635 6636
 *
 *	Change device carrier
 */
int dev_change_carrier(struct net_device *dev, bool new_carrier)
{
	const struct net_device_ops *ops = dev->netdev_ops;

	if (!ops->ndo_change_carrier)
		return -EOPNOTSUPP;
	if (!netif_device_present(dev))
		return -ENODEV;
	return ops->ndo_change_carrier(dev, new_carrier);
}
EXPORT_SYMBOL(dev_change_carrier);

6637 6638 6639 6640 6641 6642 6643 6644
/**
 *	dev_get_phys_port_id - Get device physical port ID
 *	@dev: device
 *	@ppid: port ID
 *
 *	Get device physical port ID
 */
int dev_get_phys_port_id(struct net_device *dev,
6645
			 struct netdev_phys_item_id *ppid)
6646 6647 6648 6649 6650 6651 6652 6653 6654
{
	const struct net_device_ops *ops = dev->netdev_ops;

	if (!ops->ndo_get_phys_port_id)
		return -EOPNOTSUPP;
	return ops->ndo_get_phys_port_id(dev, ppid);
}
EXPORT_SYMBOL(dev_get_phys_port_id);

6655 6656 6657 6658
/**
 *	dev_get_phys_port_name - Get device physical port name
 *	@dev: device
 *	@name: port name
6659
 *	@len: limit of bytes to copy to name
6660 6661 6662 6663 6664 6665 6666 6667 6668 6669 6670 6671 6672 6673
 *
 *	Get device physical port name
 */
int dev_get_phys_port_name(struct net_device *dev,
			   char *name, size_t len)
{
	const struct net_device_ops *ops = dev->netdev_ops;

	if (!ops->ndo_get_phys_port_name)
		return -EOPNOTSUPP;
	return ops->ndo_get_phys_port_name(dev, name, len);
}
EXPORT_SYMBOL(dev_get_phys_port_name);

6674 6675 6676 6677 6678 6679 6680 6681 6682 6683 6684 6685 6686 6687 6688 6689 6690 6691 6692 6693
/**
 *	dev_change_proto_down - update protocol port state information
 *	@dev: device
 *	@proto_down: new value
 *
 *	This info can be used by switch drivers to set the phys state of the
 *	port.
 */
int dev_change_proto_down(struct net_device *dev, bool proto_down)
{
	const struct net_device_ops *ops = dev->netdev_ops;

	if (!ops->ndo_change_proto_down)
		return -EOPNOTSUPP;
	if (!netif_device_present(dev))
		return -ENODEV;
	return ops->ndo_change_proto_down(dev, proto_down);
}
EXPORT_SYMBOL(dev_change_proto_down);

6694 6695 6696 6697
/**
 *	dev_change_xdp_fd - set or clear a bpf program for a device rx path
 *	@dev: device
 *	@fd: new program fd or negative value to clear
6698
 *	@flags: xdp-related flags
6699 6700 6701
 *
 *	Set or clear a bpf program for a device
 */
6702
int dev_change_xdp_fd(struct net_device *dev, int fd, u32 flags)
6703 6704 6705
{
	const struct net_device_ops *ops = dev->netdev_ops;
	struct bpf_prog *prog = NULL;
6706
	struct netdev_xdp xdp;
6707 6708
	int err;

6709 6710
	ASSERT_RTNL();

6711 6712 6713
	if (!ops->ndo_xdp)
		return -EOPNOTSUPP;
	if (fd >= 0) {
6714 6715 6716 6717 6718 6719 6720 6721 6722 6723 6724
		if (flags & XDP_FLAGS_UPDATE_IF_NOEXIST) {
			memset(&xdp, 0, sizeof(xdp));
			xdp.command = XDP_QUERY_PROG;

			err = ops->ndo_xdp(dev, &xdp);
			if (err < 0)
				return err;
			if (xdp.prog_attached)
				return -EBUSY;
		}

6725 6726 6727 6728 6729
		prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_XDP);
		if (IS_ERR(prog))
			return PTR_ERR(prog);
	}

6730
	memset(&xdp, 0, sizeof(xdp));
6731 6732
	xdp.command = XDP_SETUP_PROG;
	xdp.prog = prog;
6733

6734 6735 6736 6737 6738 6739 6740 6741
	err = ops->ndo_xdp(dev, &xdp);
	if (err < 0 && prog)
		bpf_prog_put(prog);

	return err;
}
EXPORT_SYMBOL(dev_change_xdp_fd);

L
Linus Torvalds 已提交
6742 6743
/**
 *	dev_new_index	-	allocate an ifindex
6744
 *	@net: the applicable net namespace
L
Linus Torvalds 已提交
6745 6746 6747 6748 6749
 *
 *	Returns a suitable unique value for a new device interface
 *	number.  The caller must hold the rtnl semaphore or the
 *	dev_base_lock to be sure it remains unique.
 */
6750
static int dev_new_index(struct net *net)
L
Linus Torvalds 已提交
6751
{
6752
	int ifindex = net->ifindex;
L
Linus Torvalds 已提交
6753 6754 6755
	for (;;) {
		if (++ifindex <= 0)
			ifindex = 1;
6756
		if (!__dev_get_by_index(net, ifindex))
6757
			return net->ifindex = ifindex;
L
Linus Torvalds 已提交
6758 6759 6760 6761
	}
}

/* Delayed registration/unregisteration */
6762
static LIST_HEAD(net_todo_list);
6763
DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
L
Linus Torvalds 已提交
6764

6765
static void net_set_todo(struct net_device *dev)
L
Linus Torvalds 已提交
6766 6767
{
	list_add_tail(&dev->todo_list, &net_todo_list);
6768
	dev_net(dev)->dev_unreg_count++;
L
Linus Torvalds 已提交
6769 6770
}

6771
static void rollback_registered_many(struct list_head *head)
6772
{
6773
	struct net_device *dev, *tmp;
6774
	LIST_HEAD(close_head);
6775

6776 6777 6778
	BUG_ON(dev_boot_phase);
	ASSERT_RTNL();

6779
	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
6780
		/* Some devices call without registering
6781 6782
		 * for initialization unwind. Remove those
		 * devices and proceed with the remaining.
6783 6784
		 */
		if (dev->reg_state == NETREG_UNINITIALIZED) {
6785 6786
			pr_debug("unregister_netdevice: device %s/%p never was registered\n",
				 dev->name, dev);
6787

6788
			WARN_ON(1);
6789 6790
			list_del(&dev->unreg_list);
			continue;
6791
		}
6792
		dev->dismantle = true;
6793
		BUG_ON(dev->reg_state != NETREG_REGISTERED);
6794
	}
6795

6796
	/* If device is running, close it first. */
6797 6798
	list_for_each_entry(dev, head, unreg_list)
		list_add_tail(&dev->close_list, &close_head);
6799
	dev_close_many(&close_head, true);
6800

6801
	list_for_each_entry(dev, head, unreg_list) {
6802 6803
		/* And unlink it from device chain. */
		unlist_netdevice(dev);
6804

6805 6806
		dev->reg_state = NETREG_UNREGISTERING;
	}
6807
	flush_all_backlogs();
6808 6809 6810

	synchronize_net();

6811
	list_for_each_entry(dev, head, unreg_list) {
6812 6813
		struct sk_buff *skb = NULL;

6814 6815
		/* Shutdown queueing discipline. */
		dev_shutdown(dev);
6816 6817


6818 6819 6820 6821
		/* Notify protocols, that we are about to destroy
		   this device. They should clean all the things.
		*/
		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
6822

6823 6824 6825 6826 6827
		if (!dev->rtnl_link_ops ||
		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
			skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U,
						     GFP_KERNEL);

6828 6829 6830
		/*
		 *	Flush the unicast and multicast chains
		 */
6831
		dev_uc_flush(dev);
6832
		dev_mc_flush(dev);
6833

6834 6835
		if (dev->netdev_ops->ndo_uninit)
			dev->netdev_ops->ndo_uninit(dev);
6836

6837 6838
		if (skb)
			rtmsg_ifinfo_send(skb, dev, GFP_KERNEL);
6839

J
Jiri Pirko 已提交
6840 6841
		/* Notifier chain MUST detach us all upper devices. */
		WARN_ON(netdev_has_any_upper_dev(dev));
6842
		WARN_ON(netdev_has_any_lower_dev(dev));
6843

6844 6845
		/* Remove entries from kobject tree */
		netdev_unregister_kobject(dev);
6846 6847 6848 6849
#ifdef CONFIG_XPS
		/* Remove XPS queueing entries */
		netif_reset_xps_queues_gt(dev, 0);
#endif
6850
	}
6851

6852
	synchronize_net();
6853

6854
	list_for_each_entry(dev, head, unreg_list)
6855 6856 6857 6858 6859 6860 6861 6862 6863
		dev_put(dev);
}

static void rollback_registered(struct net_device *dev)
{
	LIST_HEAD(single);

	list_add(&dev->unreg_list, &single);
	rollback_registered_many(&single);
E
Eric Dumazet 已提交
6864
	list_del(&single);
6865 6866
}

6867 6868 6869 6870 6871
static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
	struct net_device *upper, netdev_features_t features)
{
	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
	netdev_features_t feature;
6872
	int feature_bit;
6873

6874 6875
	for_each_netdev_feature(&upper_disables, feature_bit) {
		feature = __NETIF_F_BIT(feature_bit);
6876 6877 6878 6879 6880 6881 6882 6883 6884 6885 6886 6887 6888 6889 6890 6891
		if (!(upper->wanted_features & feature)
		    && (features & feature)) {
			netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
				   &feature, upper->name);
			features &= ~feature;
		}
	}

	return features;
}

static void netdev_sync_lower_features(struct net_device *upper,
	struct net_device *lower, netdev_features_t features)
{
	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
	netdev_features_t feature;
6892
	int feature_bit;
6893

6894 6895
	for_each_netdev_feature(&upper_disables, feature_bit) {
		feature = __NETIF_F_BIT(feature_bit);
6896 6897 6898 6899 6900 6901 6902 6903 6904 6905 6906 6907 6908
		if (!(features & feature) && (lower->features & feature)) {
			netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
				   &feature, lower->name);
			lower->wanted_features &= ~feature;
			netdev_update_features(lower);

			if (unlikely(lower->features & feature))
				netdev_WARN(upper, "failed to disable %pNF on %s!\n",
					    &feature, lower->name);
		}
	}
}

6909 6910
static netdev_features_t netdev_fix_features(struct net_device *dev,
	netdev_features_t features)
6911
{
6912 6913 6914
	/* Fix illegal checksum combinations */
	if ((features & NETIF_F_HW_CSUM) &&
	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
6915
		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
6916 6917 6918
		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
	}

6919
	/* TSO requires that SG is present as well. */
6920
	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
6921
		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
6922
		features &= ~NETIF_F_ALL_TSO;
6923 6924
	}

6925 6926 6927 6928 6929 6930 6931 6932 6933 6934 6935 6936 6937
	if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
					!(features & NETIF_F_IP_CSUM)) {
		netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
		features &= ~NETIF_F_TSO;
		features &= ~NETIF_F_TSO_ECN;
	}

	if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
					 !(features & NETIF_F_IPV6_CSUM)) {
		netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
		features &= ~NETIF_F_TSO6;
	}

6938 6939 6940 6941
	/* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
	if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
		features &= ~NETIF_F_TSO_MANGLEID;

6942 6943 6944 6945
	/* TSO ECN requires that TSO is present as well. */
	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
		features &= ~NETIF_F_TSO_ECN;

6946 6947
	/* Software GSO depends on SG. */
	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
6948
		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
6949 6950 6951
		features &= ~NETIF_F_GSO;
	}

6952
	/* UFO needs SG and checksumming */
6953
	if (features & NETIF_F_UFO) {
6954
		/* maybe split UFO into V4 and V6? */
6955 6956 6957
		if (!(features & NETIF_F_HW_CSUM) &&
		    ((features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) !=
		     (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM))) {
6958
			netdev_dbg(dev,
6959
				"Dropping NETIF_F_UFO since no checksum offload features.\n");
6960 6961 6962 6963
			features &= ~NETIF_F_UFO;
		}

		if (!(features & NETIF_F_SG)) {
6964
			netdev_dbg(dev,
6965
				"Dropping NETIF_F_UFO since no NETIF_F_SG feature.\n");
6966 6967 6968 6969
			features &= ~NETIF_F_UFO;
		}
	}

6970 6971 6972 6973 6974 6975 6976 6977
	/* GSO partial features require GSO partial be set */
	if ((features & dev->gso_partial_features) &&
	    !(features & NETIF_F_GSO_PARTIAL)) {
		netdev_dbg(dev,
			   "Dropping partially supported GSO features since no GSO partial.\n");
		features &= ~dev->gso_partial_features;
	}

J
Jiri Pirko 已提交
6978 6979 6980 6981 6982 6983 6984
#ifdef CONFIG_NET_RX_BUSY_POLL
	if (dev->netdev_ops->ndo_busy_poll)
		features |= NETIF_F_BUSY_POLL;
	else
#endif
		features &= ~NETIF_F_BUSY_POLL;

6985 6986 6987
	return features;
}

6988
int __netdev_update_features(struct net_device *dev)
6989
{
6990
	struct net_device *upper, *lower;
6991
	netdev_features_t features;
6992
	struct list_head *iter;
6993
	int err = -1;
6994

6995 6996
	ASSERT_RTNL();

6997 6998 6999 7000 7001 7002 7003 7004
	features = netdev_get_wanted_features(dev);

	if (dev->netdev_ops->ndo_fix_features)
		features = dev->netdev_ops->ndo_fix_features(dev, features);

	/* driver might be less strict about feature dependencies */
	features = netdev_fix_features(dev, features);

7005 7006 7007 7008
	/* some features can't be enabled if they're off an an upper device */
	netdev_for_each_upper_dev_rcu(dev, upper, iter)
		features = netdev_sync_upper_features(dev, upper, features);

7009
	if (dev->features == features)
7010
		goto sync_lower;
7011

7012 7013
	netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
		&dev->features, &features);
7014 7015 7016

	if (dev->netdev_ops->ndo_set_features)
		err = dev->netdev_ops->ndo_set_features(dev, features);
7017 7018
	else
		err = 0;
7019

7020
	if (unlikely(err < 0)) {
7021
		netdev_err(dev,
7022 7023
			"set_features() failed (%d); wanted %pNF, left %pNF\n",
			err, &features, &dev->features);
7024 7025 7026 7027
		/* return non-0 since some features might have changed and
		 * it's better to fire a spurious notification than miss it
		 */
		return -1;
7028 7029
	}

7030
sync_lower:
7031 7032 7033 7034 7035 7036
	/* some features must be disabled on lower devices when disabled
	 * on an upper device (think: bonding master or bridge)
	 */
	netdev_for_each_lower_dev(dev, lower, iter)
		netdev_sync_lower_features(dev, lower, features);

7037 7038 7039
	if (!err)
		dev->features = features;

7040
	return err < 0 ? 0 : 1;
7041 7042
}

7043 7044 7045 7046 7047 7048 7049 7050
/**
 *	netdev_update_features - recalculate device features
 *	@dev: the device to check
 *
 *	Recalculate dev->features set and send notifications if it
 *	has changed. Should be called after driver or hardware dependent
 *	conditions might have changed that influence the features.
 */
7051 7052 7053 7054
void netdev_update_features(struct net_device *dev)
{
	if (__netdev_update_features(dev))
		netdev_features_change(dev);
7055 7056 7057
}
EXPORT_SYMBOL(netdev_update_features);

7058 7059 7060 7061 7062 7063 7064 7065 7066 7067 7068 7069 7070 7071 7072 7073 7074
/**
 *	netdev_change_features - recalculate device features
 *	@dev: the device to check
 *
 *	Recalculate dev->features set and send notifications even
 *	if they have not changed. Should be called instead of
 *	netdev_update_features() if also dev->vlan_features might
 *	have changed to allow the changes to be propagated to stacked
 *	VLAN devices.
 */
void netdev_change_features(struct net_device *dev)
{
	__netdev_update_features(dev);
	netdev_features_change(dev);
}
EXPORT_SYMBOL(netdev_change_features);

7075 7076 7077 7078 7079 7080 7081 7082 7083 7084 7085 7086 7087 7088 7089 7090 7091 7092 7093 7094 7095 7096 7097 7098 7099 7100 7101
/**
 *	netif_stacked_transfer_operstate -	transfer operstate
 *	@rootdev: the root or lower level device to transfer state from
 *	@dev: the device to transfer operstate to
 *
 *	Transfer operational state from root to device. This is normally
 *	called when a stacking relationship exists between the root
 *	device and the device(a leaf device).
 */
void netif_stacked_transfer_operstate(const struct net_device *rootdev,
					struct net_device *dev)
{
	if (rootdev->operstate == IF_OPER_DORMANT)
		netif_dormant_on(dev);
	else
		netif_dormant_off(dev);

	if (netif_carrier_ok(rootdev)) {
		if (!netif_carrier_ok(dev))
			netif_carrier_on(dev);
	} else {
		if (netif_carrier_ok(dev))
			netif_carrier_off(dev);
	}
}
EXPORT_SYMBOL(netif_stacked_transfer_operstate);

7102
#ifdef CONFIG_SYSFS
7103 7104 7105
static int netif_alloc_rx_queues(struct net_device *dev)
{
	unsigned int i, count = dev->num_rx_queues;
T
Tom Herbert 已提交
7106
	struct netdev_rx_queue *rx;
7107
	size_t sz = count * sizeof(*rx);
7108

T
Tom Herbert 已提交
7109
	BUG_ON(count < 1);
7110

7111 7112 7113 7114 7115 7116
	rx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
	if (!rx) {
		rx = vzalloc(sz);
		if (!rx)
			return -ENOMEM;
	}
T
Tom Herbert 已提交
7117 7118 7119
	dev->_rx = rx;

	for (i = 0; i < count; i++)
T
Tom Herbert 已提交
7120
		rx[i].dev = dev;
7121 7122
	return 0;
}
T
Tom Herbert 已提交
7123
#endif
7124

C
Changli Gao 已提交
7125 7126 7127 7128 7129 7130 7131
static void netdev_init_one_queue(struct net_device *dev,
				  struct netdev_queue *queue, void *_unused)
{
	/* Initialize queue lock */
	spin_lock_init(&queue->_xmit_lock);
	netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
	queue->xmit_lock_owner = -1;
7132
	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
C
Changli Gao 已提交
7133
	queue->dev = dev;
T
Tom Herbert 已提交
7134 7135 7136
#ifdef CONFIG_BQL
	dql_init(&queue->dql, HZ);
#endif
C
Changli Gao 已提交
7137 7138
}

7139 7140
static void netif_free_tx_queues(struct net_device *dev)
{
W
WANG Cong 已提交
7141
	kvfree(dev->_tx);
7142 7143
}

7144 7145 7146 7147
static int netif_alloc_netdev_queues(struct net_device *dev)
{
	unsigned int count = dev->num_tx_queues;
	struct netdev_queue *tx;
7148
	size_t sz = count * sizeof(*tx);
7149

7150 7151
	if (count < 1 || count > 0xffff)
		return -EINVAL;
7152

7153 7154 7155 7156 7157 7158
	tx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
	if (!tx) {
		tx = vzalloc(sz);
		if (!tx)
			return -ENOMEM;
	}
7159
	dev->_tx = tx;
T
Tom Herbert 已提交
7160

7161 7162
	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
	spin_lock_init(&dev->tx_global_lock);
C
Changli Gao 已提交
7163 7164

	return 0;
7165 7166
}

7167 7168 7169 7170 7171 7172 7173 7174 7175 7176 7177
void netif_tx_stop_all_queues(struct net_device *dev)
{
	unsigned int i;

	for (i = 0; i < dev->num_tx_queues; i++) {
		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
		netif_tx_stop_queue(txq);
	}
}
EXPORT_SYMBOL(netif_tx_stop_all_queues);

L
Linus Torvalds 已提交
7178 7179 7180 7181 7182 7183 7184 7185 7186 7187 7188 7189 7190 7191 7192 7193 7194 7195 7196 7197
/**
 *	register_netdevice	- register a network device
 *	@dev: device to register
 *
 *	Take a completed network device structure and add it to the kernel
 *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
 *	chain. 0 is returned on success. A negative errno code is returned
 *	on a failure to set up the device, or if the name is a duplicate.
 *
 *	Callers must hold the rtnl semaphore. You may want
 *	register_netdev() instead of this.
 *
 *	BUGS:
 *	The locking appears insufficient to guarantee two parallel registers
 *	will not get the same name.
 */

int register_netdevice(struct net_device *dev)
{
	int ret;
7198
	struct net *net = dev_net(dev);
L
Linus Torvalds 已提交
7199 7200 7201 7202

	BUG_ON(dev_boot_phase);
	ASSERT_RTNL();

7203 7204
	might_sleep();

L
Linus Torvalds 已提交
7205 7206
	/* When net_device's are persistent, this will be fatal. */
	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
7207
	BUG_ON(!net);
L
Linus Torvalds 已提交
7208

7209
	spin_lock_init(&dev->addr_list_lock);
7210
	netdev_set_addr_lockdep_class(dev);
L
Linus Torvalds 已提交
7211

7212
	ret = dev_get_valid_name(net, dev, dev->name);
7213 7214 7215
	if (ret < 0)
		goto out;

L
Linus Torvalds 已提交
7216
	/* Init, if this function is available */
7217 7218
	if (dev->netdev_ops->ndo_init) {
		ret = dev->netdev_ops->ndo_init(dev);
L
Linus Torvalds 已提交
7219 7220 7221
		if (ret) {
			if (ret > 0)
				ret = -EIO;
7222
			goto out;
L
Linus Torvalds 已提交
7223 7224
		}
	}
7225

7226 7227
	if (((dev->hw_features | dev->features) &
	     NETIF_F_HW_VLAN_CTAG_FILTER) &&
7228 7229 7230 7231 7232 7233 7234
	    (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
	     !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
		netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
		ret = -EINVAL;
		goto err_uninit;
	}

7235 7236 7237 7238 7239 7240
	ret = -EBUSY;
	if (!dev->ifindex)
		dev->ifindex = dev_new_index(net);
	else if (__dev_get_by_index(net, dev->ifindex))
		goto err_uninit;

7241 7242 7243 7244
	/* Transfer changeable features to wanted_features and enable
	 * software offloads (GSO and GRO).
	 */
	dev->hw_features |= NETIF_F_SOFT_FEATURES;
7245 7246
	dev->features |= NETIF_F_SOFT_FEATURES;
	dev->wanted_features = dev->features & dev->hw_features;
L
Linus Torvalds 已提交
7247

7248
	if (!(dev->flags & IFF_LOOPBACK))
7249
		dev->hw_features |= NETIF_F_NOCACHE_COPY;
7250

7251 7252 7253 7254 7255
	/* If IPv4 TCP segmentation offload is supported we should also
	 * allow the device to enable segmenting the frame with the option
	 * of ignoring a static IP ID value.  This doesn't enable the
	 * feature itself but allows the user to enable it later.
	 */
7256 7257
	if (dev->hw_features & NETIF_F_TSO)
		dev->hw_features |= NETIF_F_TSO_MANGLEID;
7258 7259 7260 7261 7262 7263
	if (dev->vlan_features & NETIF_F_TSO)
		dev->vlan_features |= NETIF_F_TSO_MANGLEID;
	if (dev->mpls_features & NETIF_F_TSO)
		dev->mpls_features |= NETIF_F_TSO_MANGLEID;
	if (dev->hw_enc_features & NETIF_F_TSO)
		dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
7264

7265
	/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
7266
	 */
7267
	dev->vlan_features |= NETIF_F_HIGHDMA;
7268

7269 7270
	/* Make NETIF_F_SG inheritable to tunnel devices.
	 */
7271
	dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
7272

S
Simon Horman 已提交
7273 7274 7275 7276
	/* Make NETIF_F_SG inheritable to MPLS.
	 */
	dev->mpls_features |= NETIF_F_SG;

7277 7278 7279 7280 7281
	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
	ret = notifier_to_errno(ret);
	if (ret)
		goto err_uninit;

7282
	ret = netdev_register_kobject(dev);
7283
	if (ret)
7284
		goto err_uninit;
7285 7286
	dev->reg_state = NETREG_REGISTERED;

7287
	__netdev_update_features(dev);
7288

L
Linus Torvalds 已提交
7289 7290 7291 7292 7293 7294 7295
	/*
	 *	Default initial state at registry is that the
	 *	device is present.
	 */

	set_bit(__LINK_STATE_PRESENT, &dev->state);

7296 7297
	linkwatch_init_dev(dev);

L
Linus Torvalds 已提交
7298 7299
	dev_init_scheduler(dev);
	dev_hold(dev);
7300
	list_netdevice(dev);
7301
	add_device_randomness(dev->dev_addr, dev->addr_len);
L
Linus Torvalds 已提交
7302

7303 7304 7305 7306 7307 7308 7309
	/* If the device has permanent device address, driver should
	 * set dev_addr and also addr_assign_type should be set to
	 * NET_ADDR_PERM (default value).
	 */
	if (dev->addr_assign_type == NET_ADDR_PERM)
		memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);

L
Linus Torvalds 已提交
7310
	/* Notify protocols, that a new device appeared. */
7311
	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
7312
	ret = notifier_to_errno(ret);
7313 7314 7315 7316
	if (ret) {
		rollback_registered(dev);
		dev->reg_state = NETREG_UNREGISTERED;
	}
7317 7318 7319 7320
	/*
	 *	Prevent userspace races by waiting until the network
	 *	device is fully setup before sending notifications.
	 */
7321 7322
	if (!dev->rtnl_link_ops ||
	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
7323
		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
L
Linus Torvalds 已提交
7324 7325 7326

out:
	return ret;
7327 7328

err_uninit:
7329 7330
	if (dev->netdev_ops->ndo_uninit)
		dev->netdev_ops->ndo_uninit(dev);
7331
	goto out;
L
Linus Torvalds 已提交
7332
}
E
Eric Dumazet 已提交
7333
EXPORT_SYMBOL(register_netdevice);
L
Linus Torvalds 已提交
7334

7335 7336 7337 7338 7339 7340 7341 7342 7343 7344 7345 7346 7347 7348 7349 7350 7351 7352 7353 7354 7355 7356 7357 7358 7359 7360 7361 7362 7363 7364 7365
/**
 *	init_dummy_netdev	- init a dummy network device for NAPI
 *	@dev: device to init
 *
 *	This takes a network device structure and initialize the minimum
 *	amount of fields so it can be used to schedule NAPI polls without
 *	registering a full blown interface. This is to be used by drivers
 *	that need to tie several hardware interfaces to a single NAPI
 *	poll scheduler due to HW limitations.
 */
int init_dummy_netdev(struct net_device *dev)
{
	/* Clear everything. Note we don't initialize spinlocks
	 * are they aren't supposed to be taken by any of the
	 * NAPI code and this dummy netdev is supposed to be
	 * only ever used for NAPI polls
	 */
	memset(dev, 0, sizeof(struct net_device));

	/* make sure we BUG if trying to hit standard
	 * register/unregister code path
	 */
	dev->reg_state = NETREG_DUMMY;

	/* NAPI wants this */
	INIT_LIST_HEAD(&dev->napi_list);

	/* a dummy interface is started by default */
	set_bit(__LINK_STATE_PRESENT, &dev->state);
	set_bit(__LINK_STATE_START, &dev->state);

E
Eric Dumazet 已提交
7366 7367 7368 7369 7370
	/* Note : We dont allocate pcpu_refcnt for dummy devices,
	 * because users of this 'device' dont need to change
	 * its refcount.
	 */

7371 7372 7373 7374 7375
	return 0;
}
EXPORT_SYMBOL_GPL(init_dummy_netdev);


L
Linus Torvalds 已提交
7376 7377 7378 7379 7380 7381 7382 7383 7384
/**
 *	register_netdev	- register a network device
 *	@dev: device to register
 *
 *	Take a completed network device structure and add it to the kernel
 *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
 *	chain. 0 is returned on success. A negative errno code is returned
 *	on a failure to set up the device, or if the name is a duplicate.
 *
7385
 *	This is a wrapper around register_netdevice that takes the rtnl semaphore
L
Linus Torvalds 已提交
7386 7387 7388 7389 7390 7391 7392 7393 7394 7395 7396 7397 7398 7399
 *	and expands the device name if you passed a format string to
 *	alloc_netdev.
 */
int register_netdev(struct net_device *dev)
{
	int err;

	rtnl_lock();
	err = register_netdevice(dev);
	rtnl_unlock();
	return err;
}
EXPORT_SYMBOL(register_netdev);

E
Eric Dumazet 已提交
7400 7401 7402 7403 7404 7405 7406 7407 7408 7409
int netdev_refcnt_read(const struct net_device *dev)
{
	int i, refcnt = 0;

	for_each_possible_cpu(i)
		refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
	return refcnt;
}
EXPORT_SYMBOL(netdev_refcnt_read);

7410
/**
L
Linus Torvalds 已提交
7411
 * netdev_wait_allrefs - wait until all references are gone.
7412
 * @dev: target net_device
L
Linus Torvalds 已提交
7413 7414 7415 7416 7417 7418 7419
 *
 * This is called when unregistering network devices.
 *
 * Any protocol or device that holds a reference should register
 * for netdevice notification, and cleanup and put back the
 * reference if they receive an UNREGISTER event.
 * We can get stuck here if buggy protocols don't correctly
7420
 * call dev_put.
L
Linus Torvalds 已提交
7421 7422 7423 7424
 */
static void netdev_wait_allrefs(struct net_device *dev)
{
	unsigned long rebroadcast_time, warning_time;
E
Eric Dumazet 已提交
7425
	int refcnt;
L
Linus Torvalds 已提交
7426

7427 7428
	linkwatch_forget_dev(dev);

L
Linus Torvalds 已提交
7429
	rebroadcast_time = warning_time = jiffies;
E
Eric Dumazet 已提交
7430 7431 7432
	refcnt = netdev_refcnt_read(dev);

	while (refcnt != 0) {
L
Linus Torvalds 已提交
7433
		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
7434
			rtnl_lock();
L
Linus Torvalds 已提交
7435 7436

			/* Rebroadcast unregister notification */
7437
			call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
L
Linus Torvalds 已提交
7438

7439
			__rtnl_unlock();
7440
			rcu_barrier();
7441 7442
			rtnl_lock();

7443
			call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
L
Linus Torvalds 已提交
7444 7445 7446 7447 7448 7449 7450 7451 7452 7453 7454
			if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
				     &dev->state)) {
				/* We must not have linkwatch events
				 * pending on unregister. If this
				 * happens, we simply run the queue
				 * unscheduled, resulting in a noop
				 * for this device.
				 */
				linkwatch_run_queue();
			}

7455
			__rtnl_unlock();
L
Linus Torvalds 已提交
7456 7457 7458 7459 7460 7461

			rebroadcast_time = jiffies;
		}

		msleep(250);

E
Eric Dumazet 已提交
7462 7463
		refcnt = netdev_refcnt_read(dev);

L
Linus Torvalds 已提交
7464
		if (time_after(jiffies, warning_time + 10 * HZ)) {
7465 7466
			pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
				 dev->name, refcnt);
L
Linus Torvalds 已提交
7467 7468 7469 7470 7471 7472 7473 7474 7475 7476 7477 7478 7479 7480 7481 7482 7483 7484 7485
			warning_time = jiffies;
		}
	}
}

/* The sequence is:
 *
 *	rtnl_lock();
 *	...
 *	register_netdevice(x1);
 *	register_netdevice(x2);
 *	...
 *	unregister_netdevice(y1);
 *	unregister_netdevice(y2);
 *      ...
 *	rtnl_unlock();
 *	free_netdev(y1);
 *	free_netdev(y2);
 *
H
Herbert Xu 已提交
7486
 * We are invoked by rtnl_unlock().
L
Linus Torvalds 已提交
7487
 * This allows us to deal with problems:
7488
 * 1) We can delete sysfs objects which invoke hotplug
L
Linus Torvalds 已提交
7489 7490 7491
 *    without deadlocking with linkwatch via keventd.
 * 2) Since we run with the RTNL semaphore not held, we can sleep
 *    safely in order to wait for the netdev refcnt to drop to zero.
H
Herbert Xu 已提交
7492 7493 7494
 *
 * We must not return until all unregister events added during
 * the interval the lock was held have been completed.
L
Linus Torvalds 已提交
7495 7496 7497
 */
void netdev_run_todo(void)
{
7498
	struct list_head list;
L
Linus Torvalds 已提交
7499 7500

	/* Snapshot list, allow later requests */
7501
	list_replace_init(&net_todo_list, &list);
H
Herbert Xu 已提交
7502 7503

	__rtnl_unlock();
7504

7505 7506

	/* Wait for rcu callbacks to finish before next phase */
7507 7508 7509
	if (!list_empty(&list))
		rcu_barrier();

L
Linus Torvalds 已提交
7510 7511
	while (!list_empty(&list)) {
		struct net_device *dev
7512
			= list_first_entry(&list, struct net_device, todo_list);
L
Linus Torvalds 已提交
7513 7514
		list_del(&dev->todo_list);

7515
		rtnl_lock();
7516
		call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
7517
		__rtnl_unlock();
7518

7519
		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
7520
			pr_err("network todo '%s' but state %d\n",
7521 7522 7523 7524
			       dev->name, dev->reg_state);
			dump_stack();
			continue;
		}
L
Linus Torvalds 已提交
7525

7526
		dev->reg_state = NETREG_UNREGISTERED;
L
Linus Torvalds 已提交
7527

7528
		netdev_wait_allrefs(dev);
L
Linus Torvalds 已提交
7529

7530
		/* paranoia */
E
Eric Dumazet 已提交
7531
		BUG_ON(netdev_refcnt_read(dev));
7532 7533
		BUG_ON(!list_empty(&dev->ptype_all));
		BUG_ON(!list_empty(&dev->ptype_specific));
7534 7535
		WARN_ON(rcu_access_pointer(dev->ip_ptr));
		WARN_ON(rcu_access_pointer(dev->ip6_ptr));
7536
		WARN_ON(dev->dn_ptr);
L
Linus Torvalds 已提交
7537

7538 7539
		if (dev->destructor)
			dev->destructor(dev);
7540

7541 7542 7543 7544 7545 7546
		/* Report a network device has been unregistered */
		rtnl_lock();
		dev_net(dev)->dev_unreg_count--;
		__rtnl_unlock();
		wake_up(&netdev_unregistering_wq);

7547 7548
		/* Free network device */
		kobject_put(&dev->dev.kobj);
L
Linus Torvalds 已提交
7549 7550 7551
	}
}

7552 7553 7554 7555
/* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
 * all the same fields in the same order as net_device_stats, with only
 * the type differing, but rtnl_link_stats64 may have additional fields
 * at the end for newer counters.
7556
 */
7557 7558
void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
			     const struct net_device_stats *netdev_stats)
7559 7560
{
#if BITS_PER_LONG == 64
7561
	BUILD_BUG_ON(sizeof(*stats64) < sizeof(*netdev_stats));
7562
	memcpy(stats64, netdev_stats, sizeof(*stats64));
7563 7564 7565
	/* zero out counters that only exist in rtnl_link_stats64 */
	memset((char *)stats64 + sizeof(*netdev_stats), 0,
	       sizeof(*stats64) - sizeof(*netdev_stats));
7566
#else
7567
	size_t i, n = sizeof(*netdev_stats) / sizeof(unsigned long);
7568 7569 7570
	const unsigned long *src = (const unsigned long *)netdev_stats;
	u64 *dst = (u64 *)stats64;

7571
	BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
7572 7573
	for (i = 0; i < n; i++)
		dst[i] = src[i];
7574 7575 7576
	/* zero out counters that only exist in rtnl_link_stats64 */
	memset((char *)stats64 + n * sizeof(u64), 0,
	       sizeof(*stats64) - n * sizeof(u64));
7577 7578
#endif
}
7579
EXPORT_SYMBOL(netdev_stats_to_stats64);
7580

7581 7582 7583
/**
 *	dev_get_stats	- get network device statistics
 *	@dev: device to get statistics from
7584
 *	@storage: place to store stats
7585
 *
7586 7587 7588 7589
 *	Get network statistics from device. Return @storage.
 *	The device driver may provide its own method by setting
 *	dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
 *	otherwise the internal statistics structure is used.
7590
 */
7591 7592
struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
					struct rtnl_link_stats64 *storage)
7593
{
7594 7595
	const struct net_device_ops *ops = dev->netdev_ops;

7596 7597
	if (ops->ndo_get_stats64) {
		memset(storage, 0, sizeof(*storage));
7598 7599
		ops->ndo_get_stats64(dev, storage);
	} else if (ops->ndo_get_stats) {
7600
		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
7601 7602
	} else {
		netdev_stats_to_stats64(storage, &dev->stats);
7603
	}
7604
	storage->rx_dropped += atomic_long_read(&dev->rx_dropped);
7605
	storage->tx_dropped += atomic_long_read(&dev->tx_dropped);
7606
	storage->rx_nohandler += atomic_long_read(&dev->rx_nohandler);
7607
	return storage;
R
Rusty Russell 已提交
7608
}
7609
EXPORT_SYMBOL(dev_get_stats);
R
Rusty Russell 已提交
7610

7611
struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
7612
{
7613
	struct netdev_queue *queue = dev_ingress_queue(dev);
7614

7615 7616 7617 7618 7619 7620 7621
#ifdef CONFIG_NET_CLS_ACT
	if (queue)
		return queue;
	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
	if (!queue)
		return NULL;
	netdev_init_one_queue(dev, queue, NULL);
E
Eric Dumazet 已提交
7622
	RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
7623 7624 7625 7626
	queue->qdisc_sleeping = &noop_qdisc;
	rcu_assign_pointer(dev->ingress_queue, queue);
#endif
	return queue;
7627 7628
}

7629 7630
static const struct ethtool_ops default_ethtool_ops;

7631 7632 7633 7634 7635 7636 7637 7638
void netdev_set_default_ethtool_ops(struct net_device *dev,
				    const struct ethtool_ops *ops)
{
	if (dev->ethtool_ops == &default_ethtool_ops)
		dev->ethtool_ops = ops;
}
EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);

7639 7640 7641 7642
void netdev_freemem(struct net_device *dev)
{
	char *addr = (char *)dev - dev->padded;

W
WANG Cong 已提交
7643
	kvfree(addr);
7644 7645
}

L
Linus Torvalds 已提交
7646
/**
T
Tom Herbert 已提交
7647
 *	alloc_netdev_mqs - allocate network device
7648 7649 7650 7651 7652 7653
 *	@sizeof_priv:		size of private data to allocate space for
 *	@name:			device name format string
 *	@name_assign_type: 	origin of device name
 *	@setup:			callback to initialize device
 *	@txqs:			the number of TX subqueues to allocate
 *	@rxqs:			the number of RX subqueues to allocate
L
Linus Torvalds 已提交
7654 7655
 *
 *	Allocates a struct net_device with private data area for driver use
L
Li Zhong 已提交
7656
 *	and performs basic initialization.  Also allocates subqueue structs
T
Tom Herbert 已提交
7657
 *	for each queue on the device.
L
Linus Torvalds 已提交
7658
 */
T
Tom Herbert 已提交
7659
struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
7660
		unsigned char name_assign_type,
T
Tom Herbert 已提交
7661 7662
		void (*setup)(struct net_device *),
		unsigned int txqs, unsigned int rxqs)
L
Linus Torvalds 已提交
7663 7664
{
	struct net_device *dev;
7665
	size_t alloc_size;
7666
	struct net_device *p;
L
Linus Torvalds 已提交
7667

7668 7669
	BUG_ON(strlen(name) >= sizeof(dev->name));

T
Tom Herbert 已提交
7670
	if (txqs < 1) {
7671
		pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
7672 7673 7674
		return NULL;
	}

7675
#ifdef CONFIG_SYSFS
T
Tom Herbert 已提交
7676
	if (rxqs < 1) {
7677
		pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
T
Tom Herbert 已提交
7678 7679 7680 7681
		return NULL;
	}
#endif

7682
	alloc_size = sizeof(struct net_device);
7683 7684
	if (sizeof_priv) {
		/* ensure 32-byte alignment of private area */
7685
		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
7686 7687 7688
		alloc_size += sizeof_priv;
	}
	/* ensure 32-byte alignment of whole construct */
7689
	alloc_size += NETDEV_ALIGN - 1;
L
Linus Torvalds 已提交
7690

7691 7692 7693
	p = kzalloc(alloc_size, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
	if (!p)
		p = vzalloc(alloc_size);
7694
	if (!p)
L
Linus Torvalds 已提交
7695 7696
		return NULL;

7697
	dev = PTR_ALIGN(p, NETDEV_ALIGN);
L
Linus Torvalds 已提交
7698
	dev->padded = (char *)dev - (char *)p;
7699

E
Eric Dumazet 已提交
7700 7701
	dev->pcpu_refcnt = alloc_percpu(int);
	if (!dev->pcpu_refcnt)
7702
		goto free_dev;
7703 7704

	if (dev_addr_init(dev))
E
Eric Dumazet 已提交
7705
		goto free_pcpu;
7706

7707
	dev_mc_init(dev);
7708
	dev_uc_init(dev);
J
Jiri Pirko 已提交
7709

7710
	dev_net_set(dev, &init_net);
L
Linus Torvalds 已提交
7711

7712
	dev->gso_max_size = GSO_MAX_SIZE;
7713
	dev->gso_max_segs = GSO_MAX_SEGS;
7714 7715 7716

	INIT_LIST_HEAD(&dev->napi_list);
	INIT_LIST_HEAD(&dev->unreg_list);
7717
	INIT_LIST_HEAD(&dev->close_list);
7718
	INIT_LIST_HEAD(&dev->link_watch_list);
7719 7720
	INIT_LIST_HEAD(&dev->adj_list.upper);
	INIT_LIST_HEAD(&dev->adj_list.lower);
7721 7722
	INIT_LIST_HEAD(&dev->ptype_all);
	INIT_LIST_HEAD(&dev->ptype_specific);
7723 7724 7725
#ifdef CONFIG_NET_SCHED
	hash_init(dev->qdisc_hash);
#endif
7726
	dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
7727 7728
	setup(dev);

7729
	if (!dev->tx_queue_len) {
7730
		dev->priv_flags |= IFF_NO_QUEUE;
7731
		dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
7732
	}
7733

T
Tom Herbert 已提交
7734 7735
	dev->num_tx_queues = txqs;
	dev->real_num_tx_queues = txqs;
7736
	if (netif_alloc_netdev_queues(dev))
7737
		goto free_all;
7738

7739
#ifdef CONFIG_SYSFS
T
Tom Herbert 已提交
7740 7741
	dev->num_rx_queues = rxqs;
	dev->real_num_rx_queues = rxqs;
T
Tom Herbert 已提交
7742
	if (netif_alloc_rx_queues(dev))
7743
		goto free_all;
E
Eric Dumazet 已提交
7744
#endif
T
Tom Herbert 已提交
7745

L
Linus Torvalds 已提交
7746
	strcpy(dev->name, name);
7747
	dev->name_assign_type = name_assign_type;
7748
	dev->group = INIT_NETDEV_GROUP;
7749 7750
	if (!dev->ethtool_ops)
		dev->ethtool_ops = &default_ethtool_ops;
7751 7752 7753

	nf_hook_ingress_init(dev);

L
Linus Torvalds 已提交
7754
	return dev;
7755

7756 7757 7758 7759
free_all:
	free_netdev(dev);
	return NULL;

E
Eric Dumazet 已提交
7760 7761
free_pcpu:
	free_percpu(dev->pcpu_refcnt);
7762 7763
free_dev:
	netdev_freemem(dev);
7764
	return NULL;
L
Linus Torvalds 已提交
7765
}
T
Tom Herbert 已提交
7766
EXPORT_SYMBOL(alloc_netdev_mqs);
L
Linus Torvalds 已提交
7767 7768 7769 7770 7771

/**
 *	free_netdev - free network device
 *	@dev: device
 *
7772 7773
 *	This function does the last stage of destroying an allocated device
 * 	interface. The reference to the device object is released.
L
Linus Torvalds 已提交
7774
 *	If this is the last reference then it will be freed.
7775
 *	Must be called in process context.
L
Linus Torvalds 已提交
7776 7777 7778
 */
void free_netdev(struct net_device *dev)
{
7779 7780
	struct napi_struct *p, *n;

7781
	might_sleep();
7782
	netif_free_tx_queues(dev);
7783
#ifdef CONFIG_SYSFS
7784
	kvfree(dev->_rx);
T
Tom Herbert 已提交
7785
#endif
7786

7787
	kfree(rcu_dereference_protected(dev->ingress_queue, 1));
7788

7789 7790 7791
	/* Flush device addresses */
	dev_addr_flush(dev);

7792 7793 7794
	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
		netif_napi_del(p);

E
Eric Dumazet 已提交
7795 7796 7797
	free_percpu(dev->pcpu_refcnt);
	dev->pcpu_refcnt = NULL;

S
Stephen Hemminger 已提交
7798
	/*  Compatibility with error handling in drivers */
L
Linus Torvalds 已提交
7799
	if (dev->reg_state == NETREG_UNINITIALIZED) {
7800
		netdev_freemem(dev);
L
Linus Torvalds 已提交
7801 7802 7803 7804 7805 7806
		return;
	}

	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
	dev->reg_state = NETREG_RELEASED;

7807 7808
	/* will free via device release */
	put_device(&dev->dev);
L
Linus Torvalds 已提交
7809
}
E
Eric Dumazet 已提交
7810
EXPORT_SYMBOL(free_netdev);
7811

7812 7813 7814 7815 7816 7817
/**
 *	synchronize_net -  Synchronize with packet receive processing
 *
 *	Wait for packets currently being received to be done.
 *	Does not block later packets from starting.
 */
7818
void synchronize_net(void)
L
Linus Torvalds 已提交
7819 7820
{
	might_sleep();
7821 7822 7823 7824
	if (rtnl_is_locked())
		synchronize_rcu_expedited();
	else
		synchronize_rcu();
L
Linus Torvalds 已提交
7825
}
E
Eric Dumazet 已提交
7826
EXPORT_SYMBOL(synchronize_net);
L
Linus Torvalds 已提交
7827 7828

/**
7829
 *	unregister_netdevice_queue - remove device from the kernel
L
Linus Torvalds 已提交
7830
 *	@dev: device
7831
 *	@head: list
7832
 *
L
Linus Torvalds 已提交
7833
 *	This function shuts down a device interface and removes it
7834
 *	from the kernel tables.
7835
 *	If head not NULL, device is queued to be unregistered later.
L
Linus Torvalds 已提交
7836 7837 7838 7839 7840
 *
 *	Callers must hold the rtnl semaphore.  You may want
 *	unregister_netdev() instead of this.
 */

7841
void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
L
Linus Torvalds 已提交
7842
{
7843 7844
	ASSERT_RTNL();

7845
	if (head) {
7846
		list_move_tail(&dev->unreg_list, head);
7847 7848 7849 7850 7851
	} else {
		rollback_registered(dev);
		/* Finish processing unregister after unlock */
		net_set_todo(dev);
	}
L
Linus Torvalds 已提交
7852
}
7853
EXPORT_SYMBOL(unregister_netdevice_queue);
L
Linus Torvalds 已提交
7854

7855 7856 7857
/**
 *	unregister_netdevice_many - unregister many devices
 *	@head: list of devices
7858 7859 7860
 *
 *  Note: As most callers use a stack allocated list_head,
 *  we force a list_del() to make sure stack wont be corrupted later.
7861 7862 7863 7864 7865 7866 7867 7868 7869
 */
void unregister_netdevice_many(struct list_head *head)
{
	struct net_device *dev;

	if (!list_empty(head)) {
		rollback_registered_many(head);
		list_for_each_entry(dev, head, unreg_list)
			net_set_todo(dev);
7870
		list_del(head);
7871 7872
	}
}
7873
EXPORT_SYMBOL(unregister_netdevice_many);
7874

L
Linus Torvalds 已提交
7875 7876 7877 7878 7879
/**
 *	unregister_netdev - remove device from the kernel
 *	@dev: device
 *
 *	This function shuts down a device interface and removes it
7880
 *	from the kernel tables.
L
Linus Torvalds 已提交
7881 7882 7883 7884 7885 7886 7887 7888 7889 7890 7891 7892 7893
 *
 *	This is just a wrapper for unregister_netdevice that takes
 *	the rtnl semaphore.  In general you want to use this and not
 *	unregister_netdevice.
 */
void unregister_netdev(struct net_device *dev)
{
	rtnl_lock();
	unregister_netdevice(dev);
	rtnl_unlock();
}
EXPORT_SYMBOL(unregister_netdev);

7894 7895 7896 7897 7898 7899 7900 7901 7902 7903 7904 7905 7906 7907 7908 7909 7910 7911 7912 7913 7914 7915 7916 7917 7918 7919 7920 7921 7922 7923 7924
/**
 *	dev_change_net_namespace - move device to different nethost namespace
 *	@dev: device
 *	@net: network namespace
 *	@pat: If not NULL name pattern to try if the current device name
 *	      is already taken in the destination network namespace.
 *
 *	This function shuts down a device interface and moves it
 *	to a new network namespace. On success 0 is returned, on
 *	a failure a netagive errno code is returned.
 *
 *	Callers must hold the rtnl semaphore.
 */

int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat)
{
	int err;

	ASSERT_RTNL();

	/* Don't allow namespace local devices to be moved. */
	err = -EINVAL;
	if (dev->features & NETIF_F_NETNS_LOCAL)
		goto out;

	/* Ensure the device has been registrered */
	if (dev->reg_state != NETREG_REGISTERED)
		goto out;

	/* Get out if there is nothing todo */
	err = 0;
7925
	if (net_eq(dev_net(dev), net))
7926 7927 7928 7929 7930 7931
		goto out;

	/* Pick the destination device name, and ensure
	 * we can use it in the destination network namespace.
	 */
	err = -EEXIST;
7932
	if (__dev_get_by_name(net, dev->name)) {
7933 7934 7935
		/* We get here if we can't use the current device name */
		if (!pat)
			goto out;
7936
		if (dev_get_valid_name(net, dev, pat) < 0)
7937 7938 7939 7940 7941 7942 7943 7944
			goto out;
	}

	/*
	 * And now a mini version of register_netdevice unregister_netdevice.
	 */

	/* If device is running close it first. */
7945
	dev_close(dev);
7946 7947 7948 7949 7950 7951 7952 7953 7954 7955 7956 7957

	/* And unlink it from device chain */
	err = -ENODEV;
	unlist_netdevice(dev);

	synchronize_net();

	/* Shutdown queueing discipline. */
	dev_shutdown(dev);

	/* Notify protocols, that we are about to destroy
	   this device. They should clean all the things.
7958 7959 7960 7961

	   Note that dev->reg_state stays at NETREG_REGISTERED.
	   This is wanted because this way 8021q and macvlan know
	   the device is just moving and can keep their slaves up.
7962 7963
	*/
	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
7964 7965
	rcu_barrier();
	call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
7966
	rtmsg_ifinfo(RTM_DELLINK, dev, ~0U, GFP_KERNEL);
7967 7968 7969 7970

	/*
	 *	Flush the unicast and multicast chains
	 */
7971
	dev_uc_flush(dev);
7972
	dev_mc_flush(dev);
7973

7974 7975
	/* Send a netdev-removed uevent to the old namespace */
	kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
7976
	netdev_adjacent_del_links(dev);
7977

7978
	/* Actually switch the network namespace */
7979
	dev_net_set(dev, net);
7980 7981

	/* If there is an ifindex conflict assign a new one */
7982
	if (__dev_get_by_index(net, dev->ifindex))
7983 7984
		dev->ifindex = dev_new_index(net);

7985 7986
	/* Send a netdev-add uevent to the new namespace */
	kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
7987
	netdev_adjacent_add_links(dev);
7988

7989
	/* Fixup kobjects */
7990
	err = device_rename(&dev->dev, dev->name);
7991
	WARN_ON(err);
7992 7993 7994 7995 7996 7997 7998

	/* Add the device back in the hashes */
	list_netdevice(dev);

	/* Notify protocols, that a new device appeared. */
	call_netdevice_notifiers(NETDEV_REGISTER, dev);

7999 8000 8001 8002
	/*
	 *	Prevent userspace races by waiting until the network
	 *	device is fully setup before sending notifications.
	 */
8003
	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
8004

8005 8006 8007 8008 8009
	synchronize_net();
	err = 0;
out:
	return err;
}
8010
EXPORT_SYMBOL_GPL(dev_change_net_namespace);
8011

8012
static int dev_cpu_dead(unsigned int oldcpu)
L
Linus Torvalds 已提交
8013 8014 8015
{
	struct sk_buff **list_skb;
	struct sk_buff *skb;
8016
	unsigned int cpu;
L
Linus Torvalds 已提交
8017 8018 8019 8020 8021 8022 8023 8024 8025 8026 8027 8028 8029 8030 8031 8032
	struct softnet_data *sd, *oldsd;

	local_irq_disable();
	cpu = smp_processor_id();
	sd = &per_cpu(softnet_data, cpu);
	oldsd = &per_cpu(softnet_data, oldcpu);

	/* Find end of our completion_queue. */
	list_skb = &sd->completion_queue;
	while (*list_skb)
		list_skb = &(*list_skb)->next;
	/* Append completion queue from offline CPU. */
	*list_skb = oldsd->completion_queue;
	oldsd->completion_queue = NULL;

	/* Append output queue from offline CPU. */
8033 8034 8035 8036 8037 8038
	if (oldsd->output_queue) {
		*sd->output_queue_tailp = oldsd->output_queue;
		sd->output_queue_tailp = oldsd->output_queue_tailp;
		oldsd->output_queue = NULL;
		oldsd->output_queue_tailp = &oldsd->output_queue;
	}
E
Eric Dumazet 已提交
8039 8040 8041 8042 8043 8044 8045 8046 8047 8048 8049 8050 8051 8052
	/* Append NAPI poll list from offline CPU, with one exception :
	 * process_backlog() must be called by cpu owning percpu backlog.
	 * We properly handle process_queue & input_pkt_queue later.
	 */
	while (!list_empty(&oldsd->poll_list)) {
		struct napi_struct *napi = list_first_entry(&oldsd->poll_list,
							    struct napi_struct,
							    poll_list);

		list_del_init(&napi->poll_list);
		if (napi->poll == process_backlog)
			napi->state = 0;
		else
			____napi_schedule(sd, napi);
8053
	}
L
Linus Torvalds 已提交
8054 8055 8056 8057 8058

	raise_softirq_irqoff(NET_TX_SOFTIRQ);
	local_irq_enable();

	/* Process offline CPU's input_pkt_queue */
8059
	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
8060
		netif_rx_ni(skb);
8061
		input_queue_head_incr(oldsd);
T
Tom Herbert 已提交
8062
	}
E
Eric Dumazet 已提交
8063
	while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
8064
		netif_rx_ni(skb);
8065 8066
		input_queue_head_incr(oldsd);
	}
L
Linus Torvalds 已提交
8067

8068
	return 0;
L
Linus Torvalds 已提交
8069 8070
}

8071
/**
8072 8073 8074 8075
 *	netdev_increment_features - increment feature set by one
 *	@all: current feature set
 *	@one: new feature set
 *	@mask: mask feature set
8076 8077
 *
 *	Computes a new feature set after adding a device with feature set
8078 8079
 *	@one to the master device with current feature set @all.  Will not
 *	enable anything that is off in @mask. Returns the new feature set.
8080
 */
8081 8082
netdev_features_t netdev_increment_features(netdev_features_t all,
	netdev_features_t one, netdev_features_t mask)
8083
{
8084
	if (mask & NETIF_F_HW_CSUM)
8085
		mask |= NETIF_F_CSUM_MASK;
8086
	mask |= NETIF_F_VLAN_CHALLENGED;
8087

8088
	all |= one & (NETIF_F_ONE_FOR_ALL | NETIF_F_CSUM_MASK) & mask;
8089
	all &= one | ~NETIF_F_ALL_FOR_ALL;
8090

8091
	/* If one device supports hw checksumming, set for all. */
8092 8093
	if (all & NETIF_F_HW_CSUM)
		all &= ~(NETIF_F_CSUM_MASK & ~NETIF_F_HW_CSUM);
8094 8095 8096

	return all;
}
8097
EXPORT_SYMBOL(netdev_increment_features);
8098

8099
static struct hlist_head * __net_init netdev_create_hash(void)
8100 8101 8102 8103 8104 8105 8106 8107 8108 8109 8110 8111
{
	int i;
	struct hlist_head *hash;

	hash = kmalloc(sizeof(*hash) * NETDEV_HASHENTRIES, GFP_KERNEL);
	if (hash != NULL)
		for (i = 0; i < NETDEV_HASHENTRIES; i++)
			INIT_HLIST_HEAD(&hash[i]);

	return hash;
}

8112
/* Initialize per network namespace state */
8113
static int __net_init netdev_init(struct net *net)
8114
{
8115 8116
	if (net != &init_net)
		INIT_LIST_HEAD(&net->dev_base_head);
8117

8118 8119 8120
	net->dev_name_head = netdev_create_hash();
	if (net->dev_name_head == NULL)
		goto err_name;
8121

8122 8123 8124
	net->dev_index_head = netdev_create_hash();
	if (net->dev_index_head == NULL)
		goto err_idx;
8125 8126

	return 0;
8127 8128 8129 8130 8131

err_idx:
	kfree(net->dev_name_head);
err_name:
	return -ENOMEM;
8132 8133
}

8134 8135 8136 8137 8138 8139
/**
 *	netdev_drivername - network driver for the device
 *	@dev: network device
 *
 *	Determine network driver for device.
 */
8140
const char *netdev_drivername(const struct net_device *dev)
8141
{
8142 8143
	const struct device_driver *driver;
	const struct device *parent;
8144
	const char *empty = "";
8145 8146 8147

	parent = dev->dev.parent;
	if (!parent)
8148
		return empty;
8149 8150 8151

	driver = parent->driver;
	if (driver && driver->name)
8152 8153
		return driver->name;
	return empty;
8154 8155
}

8156 8157
static void __netdev_printk(const char *level, const struct net_device *dev,
			    struct va_format *vaf)
8158
{
8159
	if (dev && dev->dev.parent) {
8160 8161 8162 8163 8164 8165 8166
		dev_printk_emit(level[1] - '0',
				dev->dev.parent,
				"%s %s %s%s: %pV",
				dev_driver_string(dev->dev.parent),
				dev_name(dev->dev.parent),
				netdev_name(dev), netdev_reg_state(dev),
				vaf);
8167
	} else if (dev) {
8168 8169
		printk("%s%s%s: %pV",
		       level, netdev_name(dev), netdev_reg_state(dev), vaf);
8170
	} else {
8171
		printk("%s(NULL net_device): %pV", level, vaf);
8172
	}
8173 8174
}

8175 8176
void netdev_printk(const char *level, const struct net_device *dev,
		   const char *format, ...)
8177 8178 8179 8180 8181 8182 8183 8184 8185
{
	struct va_format vaf;
	va_list args;

	va_start(args, format);

	vaf.fmt = format;
	vaf.va = &args;

8186
	__netdev_printk(level, dev, &vaf);
8187

8188 8189 8190 8191 8192
	va_end(args);
}
EXPORT_SYMBOL(netdev_printk);

#define define_netdev_printk_level(func, level)			\
8193
void func(const struct net_device *dev, const char *fmt, ...)	\
8194 8195 8196 8197 8198 8199 8200 8201 8202
{								\
	struct va_format vaf;					\
	va_list args;						\
								\
	va_start(args, fmt);					\
								\
	vaf.fmt = fmt;						\
	vaf.va = &args;						\
								\
8203
	__netdev_printk(level, dev, &vaf);			\
8204
								\
8205 8206 8207 8208 8209 8210 8211 8212 8213 8214 8215 8216
	va_end(args);						\
}								\
EXPORT_SYMBOL(func);

define_netdev_printk_level(netdev_emerg, KERN_EMERG);
define_netdev_printk_level(netdev_alert, KERN_ALERT);
define_netdev_printk_level(netdev_crit, KERN_CRIT);
define_netdev_printk_level(netdev_err, KERN_ERR);
define_netdev_printk_level(netdev_warn, KERN_WARNING);
define_netdev_printk_level(netdev_notice, KERN_NOTICE);
define_netdev_printk_level(netdev_info, KERN_INFO);

8217
static void __net_exit netdev_exit(struct net *net)
8218 8219 8220 8221 8222
{
	kfree(net->dev_name_head);
	kfree(net->dev_index_head);
}

8223
static struct pernet_operations __net_initdata netdev_net_ops = {
8224 8225 8226 8227
	.init = netdev_init,
	.exit = netdev_exit,
};

8228
static void __net_exit default_device_exit(struct net *net)
8229
{
8230
	struct net_device *dev, *aux;
8231
	/*
8232
	 * Push all migratable network devices back to the
8233 8234 8235
	 * initial network namespace
	 */
	rtnl_lock();
8236
	for_each_netdev_safe(net, dev, aux) {
8237
		int err;
8238
		char fb_name[IFNAMSIZ];
8239 8240 8241 8242 8243

		/* Ignore unmoveable devices (i.e. loopback) */
		if (dev->features & NETIF_F_NETNS_LOCAL)
			continue;

8244 8245 8246
		/* Leave virtual devices for the generic cleanup */
		if (dev->rtnl_link_ops)
			continue;
8247

L
Lucas De Marchi 已提交
8248
		/* Push remaining network devices to init_net */
8249 8250
		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
		err = dev_change_net_namespace(dev, &init_net, fb_name);
8251
		if (err) {
8252 8253
			pr_emerg("%s: failed to move %s to init_net: %d\n",
				 __func__, dev->name, err);
8254
			BUG();
8255 8256 8257 8258 8259
		}
	}
	rtnl_unlock();
}

8260 8261 8262 8263 8264 8265 8266
static void __net_exit rtnl_lock_unregistering(struct list_head *net_list)
{
	/* Return with the rtnl_lock held when there are no network
	 * devices unregistering in any network namespace in net_list.
	 */
	struct net *net;
	bool unregistering;
8267
	DEFINE_WAIT_FUNC(wait, woken_wake_function);
8268

8269
	add_wait_queue(&netdev_unregistering_wq, &wait);
8270 8271 8272 8273 8274 8275 8276 8277 8278 8279 8280 8281
	for (;;) {
		unregistering = false;
		rtnl_lock();
		list_for_each_entry(net, net_list, exit_list) {
			if (net->dev_unreg_count > 0) {
				unregistering = true;
				break;
			}
		}
		if (!unregistering)
			break;
		__rtnl_unlock();
8282 8283

		wait_woken(&wait, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
8284
	}
8285
	remove_wait_queue(&netdev_unregistering_wq, &wait);
8286 8287
}

8288 8289 8290
static void __net_exit default_device_exit_batch(struct list_head *net_list)
{
	/* At exit all network devices most be removed from a network
8291
	 * namespace.  Do this in the reverse order of registration.
8292 8293 8294 8295 8296 8297 8298
	 * Do this across as many network namespaces as possible to
	 * improve batching efficiency.
	 */
	struct net_device *dev;
	struct net *net;
	LIST_HEAD(dev_kill_list);

8299 8300 8301 8302 8303 8304 8305 8306 8307 8308 8309 8310
	/* To prevent network device cleanup code from dereferencing
	 * loopback devices or network devices that have been freed
	 * wait here for all pending unregistrations to complete,
	 * before unregistring the loopback device and allowing the
	 * network namespace be freed.
	 *
	 * The netdev todo list containing all network devices
	 * unregistrations that happen in default_device_exit_batch
	 * will run in the rtnl_unlock() at the end of
	 * default_device_exit_batch.
	 */
	rtnl_lock_unregistering(net_list);
8311 8312
	list_for_each_entry(net, net_list, exit_list) {
		for_each_netdev_reverse(net, dev) {
8313
			if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
8314 8315 8316 8317 8318 8319 8320 8321 8322
				dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
			else
				unregister_netdevice_queue(dev, &dev_kill_list);
		}
	}
	unregister_netdevice_many(&dev_kill_list);
	rtnl_unlock();
}

8323
static struct pernet_operations __net_initdata default_device_ops = {
8324
	.exit = default_device_exit,
8325
	.exit_batch = default_device_exit_batch,
8326 8327
};

L
Linus Torvalds 已提交
8328 8329 8330 8331 8332 8333 8334 8335 8336 8337 8338 8339 8340 8341 8342 8343 8344 8345 8346 8347
/*
 *	Initialize the DEV module. At boot time this walks the device list and
 *	unhooks any devices that fail to initialise (normally hardware not
 *	present) and leaves us with a valid list of present and active devices.
 *
 */

/*
 *       This is called single threaded during boot, so no need
 *       to take the rtnl semaphore.
 */
static int __init net_dev_init(void)
{
	int i, rc = -ENOMEM;

	BUG_ON(!dev_boot_phase);

	if (dev_proc_init())
		goto out;

8348
	if (netdev_kobject_init())
L
Linus Torvalds 已提交
8349 8350 8351
		goto out;

	INIT_LIST_HEAD(&ptype_all);
8352
	for (i = 0; i < PTYPE_HASH_SIZE; i++)
L
Linus Torvalds 已提交
8353 8354
		INIT_LIST_HEAD(&ptype_base[i]);

8355 8356
	INIT_LIST_HEAD(&offload_base);

8357 8358
	if (register_pernet_subsys(&netdev_net_ops))
		goto out;
L
Linus Torvalds 已提交
8359 8360 8361 8362 8363

	/*
	 *	Initialise the packet receive queues.
	 */

8364
	for_each_possible_cpu(i) {
8365
		struct work_struct *flush = per_cpu_ptr(&flush_works, i);
E
Eric Dumazet 已提交
8366
		struct softnet_data *sd = &per_cpu(softnet_data, i);
L
Linus Torvalds 已提交
8367

8368 8369
		INIT_WORK(flush, flush_backlog);

E
Eric Dumazet 已提交
8370
		skb_queue_head_init(&sd->input_pkt_queue);
8371
		skb_queue_head_init(&sd->process_queue);
E
Eric Dumazet 已提交
8372
		INIT_LIST_HEAD(&sd->poll_list);
8373
		sd->output_queue_tailp = &sd->output_queue;
E
Eric Dumazet 已提交
8374
#ifdef CONFIG_RPS
E
Eric Dumazet 已提交
8375 8376 8377
		sd->csd.func = rps_trigger_softirq;
		sd->csd.info = sd;
		sd->cpu = i;
8378
#endif
T
Tom Herbert 已提交
8379

E
Eric Dumazet 已提交
8380 8381
		sd->backlog.poll = process_backlog;
		sd->backlog.weight = weight_p;
L
Linus Torvalds 已提交
8382 8383 8384 8385
	}

	dev_boot_phase = 0;

8386 8387 8388 8389 8390 8391 8392 8393 8394 8395 8396 8397 8398 8399 8400
	/* The loopback device is special if any other network devices
	 * is present in a network namespace the loopback device must
	 * be present. Since we now dynamically allocate and free the
	 * loopback device ensure this invariant is maintained by
	 * keeping the loopback device as the first device on the
	 * list of network devices.  Ensuring the loopback devices
	 * is the first device that appears and the last network device
	 * that disappears.
	 */
	if (register_pernet_device(&loopback_net_ops))
		goto out;

	if (register_pernet_device(&default_device_ops))
		goto out;

8401 8402
	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
L
Linus Torvalds 已提交
8403

8404 8405 8406
	rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
				       NULL, dev_cpu_dead);
	WARN_ON(rc < 0);
T
Thomas Graf 已提交
8407
	dst_subsys_init();
L
Linus Torvalds 已提交
8408 8409 8410 8411 8412 8413
	rc = 0;
out:
	return rc;
}

subsys_initcall(net_dev_init);