dev.c 174.6 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
 */

#include <asm/uaccess.h>
#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 <net/net_namespace.h>
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#include <net/sock.h>
#include <linux/rtnetlink.h>
#include <linux/stat.h>
#include <net/dst.h>
#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 <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 "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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/*
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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);

static unsigned int napi_gen_id;
static DEFINE_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(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))
		return &ptype_all;
	else
		return &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
}

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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)
{
	struct list_head *head = &offload_base;

	spin_lock(&offload_lock);
	list_add_rcu(&po->list, head);
	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));
551
			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] != ' ' &&
576
		    !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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Eric Dumazet 已提交
586
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
	 */
611
	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

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

/**
 *	__dev_get_by_name	- find a device by its name
657
 *	@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.
 */

667
struct net_device *__dev_get_by_name(struct net *net, const char *name)
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{
E
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	struct net_device *dev;
	struct hlist_head *head = dev_name_hash(net, name);
L
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672
	hlist_for_each_entry(dev, head, name_hlist)
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		if (!strncmp(dev->name, name, IFNAMSIZ))
			return dev;
E
Eric Dumazet 已提交
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L
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	return NULL;
}
E
Eric Dumazet 已提交
678
EXPORT_SYMBOL(__dev_get_by_name);
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680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696
/**
 *	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);

697
	hlist_for_each_entry_rcu(dev, head, name_hlist)
698 699 700 701 702 703 704
		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
707
 *	@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.
 */

717
struct net_device *dev_get_by_name(struct net *net, const char *name)
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{
	struct net_device *dev;

721 722
	rcu_read_lock();
	dev = dev_get_by_name_rcu(net, name);
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	if (dev)
		dev_hold(dev);
725
	rcu_read_unlock();
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	return dev;
}
E
Eric Dumazet 已提交
728
EXPORT_SYMBOL(dev_get_by_name);
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/**
 *	__dev_get_by_index - find a device by its ifindex
732
 *	@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.
 */

742
struct net_device *__dev_get_by_index(struct net *net, int ifindex)
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{
E
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	struct net_device *dev;
	struct hlist_head *head = dev_index_hash(net, ifindex);
L
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746

747
	hlist_for_each_entry(dev, head, index_hlist)
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748 749
		if (dev->ifindex == ifindex)
			return dev;
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Eric Dumazet 已提交
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	return NULL;
}
E
Eric Dumazet 已提交
753
EXPORT_SYMBOL(__dev_get_by_index);
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755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770
/**
 *	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);

771
	hlist_for_each_entry_rcu(dev, head, index_hlist)
772 773 774 775 776 777 778
		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
782
 *	@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.
 */

791
struct net_device *dev_get_by_index(struct net *net, int ifindex)
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{
	struct net_device *dev;

795 796
	rcu_read_lock();
	dev = dev_get_by_index_rcu(net, ifindex);
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	if (dev)
		dev_hold(dev);
799
	rcu_read_unlock();
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	return dev;
}
E
Eric Dumazet 已提交
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EXPORT_SYMBOL(dev_get_by_index);
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804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837
/**
 *	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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838
/**
839
 *	dev_getbyhwaddr_rcu - find a device by its hardware address
840
 *	@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
E
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 *	is not found or a pointer to the device.
 *	The caller must hold RCU or RTNL.
847
 *	The returned device has not had its ref count increased
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 *	and the caller must therefore be careful about locking
 *
 */

852 853
struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
				       const char *ha)
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{
	struct net_device *dev;

857
	for_each_netdev_rcu(net, dev)
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		if (dev->type == type &&
		    !memcmp(dev->dev_addr, ha, dev->addr_len))
860 861 862
			return dev;

	return NULL;
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}
864
EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
865

866
struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type)
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{
	struct net_device *dev;

870
	ASSERT_RTNL();
871
	for_each_netdev(net, dev)
872
		if (dev->type == type)
873 874 875
			return dev;

	return NULL;
876 877 878
}
EXPORT_SYMBOL(__dev_getfirstbyhwtype);

879
struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
880
{
881
	struct net_device *dev, *ret = NULL;
882

883 884 885 886 887 888 889 890 891
	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);

/**
E
Eric Dumazet 已提交
896
 *	dev_get_by_flags_rcu - find any device with given flags
897
 *	@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
E
Eric Dumazet 已提交
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 *	is not found or a pointer to the device. Must be called inside
 *	rcu_read_lock(), and result refcount is unchanged.
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 */

E
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906
struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags,
E
Eric Dumazet 已提交
907
				    unsigned short mask)
L
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{
909
	struct net_device *dev, *ret;
L
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910

911
	ret = NULL;
912
	for_each_netdev_rcu(net, dev) {
L
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913
		if (((dev->flags ^ if_flags) & mask) == 0) {
914
			ret = dev;
L
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			break;
		}
	}
918
	return ret;
L
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}
E
Eric Dumazet 已提交
920
EXPORT_SYMBOL(dev_get_by_flags_rcu);
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921 922 923 924 925 926

/**
 *	dev_valid_name - check if name is okay for network device
 *	@name: name string
 *
 *	Network device names need to be valid file names to
927 928
 *	to allow sysfs to work.  We also disallow any kind of
 *	whitespace.
L
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929
 */
930
bool dev_valid_name(const char *name)
L
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{
932
	if (*name == '\0')
933
		return false;
934
	if (strlen(name) >= IFNAMSIZ)
935
		return false;
936
	if (!strcmp(name, ".") || !strcmp(name, ".."))
937
		return false;
938 939 940

	while (*name) {
		if (*name == '/' || isspace(*name))
941
			return false;
942 943
		name++;
	}
944
	return true;
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}
E
Eric Dumazet 已提交
946
EXPORT_SYMBOL(dev_valid_name);
L
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947 948

/**
949 950
 *	__dev_alloc_name - allocate a name for a device
 *	@net: network namespace to allocate the device name in
L
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951
 *	@name: name format string
952
 *	@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
Stephen Hemminger 已提交
955 956 957 958 959 960
 *	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.
L
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 */

963
static int __dev_alloc_name(struct net *net, const char *name, char *buf)
L
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{
	int i = 0;
	const char *p;
	const int max_netdevices = 8*PAGE_SIZE;
S
Stephen Hemminger 已提交
968
	unsigned long *inuse;
L
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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 */
S
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;

986
		for_each_netdev(net, d) {
L
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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 */
993
			snprintf(buf, IFNAMSIZ, name, i);
L
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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);
	}

1002 1003
	if (buf != name)
		snprintf(buf, IFNAMSIZ, name, i);
1004
	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;
}

1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033
/**
 *	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;

1034 1035
	BUG_ON(!dev_net(dev));
	net = dev_net(dev);
1036 1037 1038 1039 1040
	ret = __dev_alloc_name(net, name, buf);
	if (ret >= 0)
		strlcpy(dev->name, buf, IFNAMSIZ);
	return ret;
}
E
Eric Dumazet 已提交
1041
EXPORT_SYMBOL(dev_alloc_name);
1042

1043 1044 1045
static int dev_alloc_name_ns(struct net *net,
			     struct net_device *dev,
			     const char *name)
1046
{
1047 1048
	char buf[IFNAMSIZ];
	int ret;
1049

1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060
	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);
1061

1062 1063 1064
	if (!dev_valid_name(name))
		return -EINVAL;

1065
	if (strchr(name, '%'))
1066
		return dev_alloc_name_ns(net, dev, name);
1067 1068
	else if (__dev_get_by_name(net, name))
		return -EEXIST;
1069 1070
	else if (dev->name != name)
		strlcpy(dev->name, name, IFNAMSIZ);
1071 1072 1073

	return 0;
}
L
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1074 1075 1076 1077 1078 1079 1080 1081 1082

/**
 *	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.
 */
1083
int dev_change_name(struct net_device *dev, const char *newname)
L
Linus Torvalds 已提交
1084
{
1085
	char oldname[IFNAMSIZ];
L
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1086
	int err = 0;
1087
	int ret;
1088
	struct net *net;
L
Linus Torvalds 已提交
1089 1090

	ASSERT_RTNL();
1091
	BUG_ON(!dev_net(dev));
L
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1092

1093
	net = dev_net(dev);
L
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	if (dev->flags & IFF_UP)
		return -EBUSY;

1097
	write_seqcount_begin(&devnet_rename_seq);
1098 1099

	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1100
		write_seqcount_end(&devnet_rename_seq);
1101
		return 0;
1102
	}
1103

1104 1105
	memcpy(oldname, dev->name, IFNAMSIZ);

1106
	err = dev_get_valid_name(net, dev, newname);
1107
	if (err < 0) {
1108
		write_seqcount_end(&devnet_rename_seq);
1109
		return err;
1110
	}
L
Linus Torvalds 已提交
1111

1112
rollback:
1113 1114 1115
	ret = device_rename(&dev->dev, dev->name);
	if (ret) {
		memcpy(dev->name, oldname, IFNAMSIZ);
1116
		write_seqcount_end(&devnet_rename_seq);
1117
		return ret;
1118
	}
1119

1120
	write_seqcount_end(&devnet_rename_seq);
1121

1122 1123
	netdev_adjacent_rename_links(dev, oldname);

1124
	write_lock_bh(&dev_base_lock);
1125
	hlist_del_rcu(&dev->name_hlist);
1126 1127 1128 1129 1130 1131
	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));
1132 1133
	write_unlock_bh(&dev_base_lock);

1134
	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1135 1136 1137
	ret = notifier_to_errno(ret);

	if (ret) {
1138 1139
		/* err >= 0 after dev_alloc_name() or stores the first errno */
		if (err >= 0) {
1140
			err = ret;
1141
			write_seqcount_begin(&devnet_rename_seq);
1142
			memcpy(dev->name, oldname, IFNAMSIZ);
1143
			memcpy(oldname, newname, IFNAMSIZ);
1144
			goto rollback;
1145
		} else {
1146
			pr_err("%s: name change rollback failed: %d\n",
1147
			       dev->name, ret);
1148 1149
		}
	}
L
Linus Torvalds 已提交
1150 1151 1152 1153

	return err;
}

1154 1155 1156 1157
/**
 *	dev_set_alias - change ifalias of a device
 *	@dev: device
 *	@alias: name up to IFALIASZ
1158
 *	@len: limit of bytes to copy from info
1159 1160 1161 1162 1163
 *
 *	Set ifalias for a device,
 */
int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
{
1164 1165
	char *new_ifalias;

1166 1167 1168 1169 1170
	ASSERT_RTNL();

	if (len >= IFALIASZ)
		return -EINVAL;

1171
	if (!len) {
1172 1173
		kfree(dev->ifalias);
		dev->ifalias = NULL;
1174 1175 1176
		return 0;
	}

1177 1178
	new_ifalias = krealloc(dev->ifalias, len + 1, GFP_KERNEL);
	if (!new_ifalias)
1179
		return -ENOMEM;
1180
	dev->ifalias = new_ifalias;
1181 1182 1183 1184 1185 1186

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


1187
/**
S
Stephen Hemminger 已提交
1188
 *	netdev_features_change - device changes features
1189 1190 1191 1192 1193 1194
 *	@dev: device to cause notification
 *
 *	Called to indicate a device has changed features.
 */
void netdev_features_change(struct net_device *dev)
{
1195
	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1196 1197 1198
}
EXPORT_SYMBOL(netdev_features_change);

L
Linus Torvalds 已提交
1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209
/**
 *	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) {
1210
		call_netdevice_notifiers(NETDEV_CHANGE, dev);
1211
		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);
L
Linus Torvalds 已提交
1212 1213
	}
}
E
Eric Dumazet 已提交
1214
EXPORT_SYMBOL(netdev_state_change);
L
Linus Torvalds 已提交
1215

1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226
/**
 * 	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)
1227
{
1228 1229 1230
	rtnl_lock();
	call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
	rtnl_unlock();
1231
}
1232
EXPORT_SYMBOL(netdev_notify_peers);
1233

1234
static int __dev_open(struct net_device *dev)
L
Linus Torvalds 已提交
1235
{
1236
	const struct net_device_ops *ops = dev->netdev_ops;
1237
	int ret;
L
Linus Torvalds 已提交
1238

1239 1240
	ASSERT_RTNL();

L
Linus Torvalds 已提交
1241 1242 1243
	if (!netif_device_present(dev))
		return -ENODEV;

1244 1245 1246 1247
	/* 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
	 */
1248
	netpoll_rx_disable(dev);
1249

1250 1251 1252 1253 1254
	ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
	ret = notifier_to_errno(ret);
	if (ret)
		return ret;

L
Linus Torvalds 已提交
1255
	set_bit(__LINK_STATE_START, &dev->state);
1256

1257 1258
	if (ops->ndo_validate_addr)
		ret = ops->ndo_validate_addr(dev);
1259

1260 1261
	if (!ret && ops->ndo_open)
		ret = ops->ndo_open(dev);
L
Linus Torvalds 已提交
1262

1263 1264
	netpoll_rx_enable(dev);

1265 1266 1267
	if (ret)
		clear_bit(__LINK_STATE_START, &dev->state);
	else {
L
Linus Torvalds 已提交
1268
		dev->flags |= IFF_UP;
1269
		net_dmaengine_get();
1270
		dev_set_rx_mode(dev);
L
Linus Torvalds 已提交
1271
		dev_activate(dev);
1272
		add_device_randomness(dev->dev_addr, dev->addr_len);
L
Linus Torvalds 已提交
1273
	}
1274

L
Linus Torvalds 已提交
1275 1276 1277 1278
	return ret;
}

/**
1279 1280
 *	dev_open	- prepare an interface for use.
 *	@dev:	device to open
L
Linus Torvalds 已提交
1281
 *
1282 1283 1284 1285 1286 1287 1288
 *	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
1289
 */
1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300
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;

1301
	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1302 1303 1304 1305 1306 1307
	call_netdevice_notifiers(NETDEV_UP, dev);

	return ret;
}
EXPORT_SYMBOL(dev_open);

1308
static int __dev_close_many(struct list_head *head)
L
Linus Torvalds 已提交
1309
{
1310
	struct net_device *dev;
1311

1312
	ASSERT_RTNL();
1313 1314
	might_sleep();

1315
	list_for_each_entry(dev, head, close_list) {
1316
		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
L
Linus Torvalds 已提交
1317

1318
		clear_bit(__LINK_STATE_START, &dev->state);
L
Linus Torvalds 已提交
1319

1320 1321 1322 1323 1324 1325 1326 1327
		/* 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.
		 */
		smp_mb__after_clear_bit(); /* Commit netif_running(). */
	}
L
Linus Torvalds 已提交
1328

1329
	dev_deactivate_many(head);
1330

1331
	list_for_each_entry(dev, head, close_list) {
1332
		const struct net_device_ops *ops = dev->netdev_ops;
L
Linus Torvalds 已提交
1333

1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352
		/*
		 *	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;
		net_dmaengine_put();
	}

	return 0;
}

static int __dev_close(struct net_device *dev)
{
1353
	int retval;
1354 1355
	LIST_HEAD(single);

1356
	/* Temporarily disable netpoll until the interface is down */
1357
	netpoll_rx_disable(dev);
1358

1359
	list_add(&dev->close_list, &single);
1360 1361
	retval = __dev_close_many(&single);
	list_del(&single);
1362 1363

	netpoll_rx_enable(dev);
1364
	return retval;
1365 1366
}

E
Eric Dumazet 已提交
1367
static int dev_close_many(struct list_head *head)
1368 1369
{
	struct net_device *dev, *tmp;
L
Linus Torvalds 已提交
1370

1371 1372
	/* Remove the devices that don't need to be closed */
	list_for_each_entry_safe(dev, tmp, head, close_list)
1373
		if (!(dev->flags & IFF_UP))
1374
			list_del_init(&dev->close_list);
1375 1376

	__dev_close_many(head);
L
Linus Torvalds 已提交
1377

1378
	list_for_each_entry_safe(dev, tmp, head, close_list) {
1379
		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1380
		call_netdevice_notifiers(NETDEV_DOWN, dev);
1381
		list_del_init(&dev->close_list);
1382
	}
1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397

	return 0;
}

/**
 *	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)
{
1398 1399
	if (dev->flags & IFF_UP) {
		LIST_HEAD(single);
L
Linus Torvalds 已提交
1400

1401
		/* Block netpoll rx while the interface is going down */
1402
		netpoll_rx_disable(dev);
1403

1404
		list_add(&dev->close_list, &single);
1405 1406
		dev_close_many(&single);
		list_del(&single);
1407 1408

		netpoll_rx_enable(dev);
1409
	}
1410
	return 0;
L
Linus Torvalds 已提交
1411
}
E
Eric Dumazet 已提交
1412
EXPORT_SYMBOL(dev_close);
L
Linus Torvalds 已提交
1413 1414


1415 1416 1417 1418 1419 1420 1421 1422 1423 1424
/**
 *	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)
{
1425 1426 1427 1428 1429 1430 1431
	/*
	 * If we're trying to disable lro on a vlan device
	 * use the underlying physical device instead
	 */
	if (is_vlan_dev(dev))
		dev = vlan_dev_real_dev(dev);

1432 1433 1434 1435
	/* the same for macvlan devices */
	if (netif_is_macvlan(dev))
		dev = macvlan_dev_real_dev(dev);

M
Michał Mirosław 已提交
1436 1437
	dev->wanted_features &= ~NETIF_F_LRO;
	netdev_update_features(dev);
1438

1439 1440
	if (unlikely(dev->features & NETIF_F_LRO))
		netdev_WARN(dev, "failed to disable LRO!\n");
1441 1442 1443
}
EXPORT_SYMBOL(dev_disable_lro);

1444 1445 1446 1447 1448 1449 1450 1451
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);
}
1452

1453 1454
static int dev_boot_phase = 1;

L
Linus Torvalds 已提交
1455 1456 1457 1458 1459 1460 1461 1462 1463 1464
/**
 *	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
1465
 *	to the new notifier to allow device to have a race free
L
Linus Torvalds 已提交
1466 1467 1468 1469 1470 1471
 *	view of the network device list.
 */

int register_netdevice_notifier(struct notifier_block *nb)
{
	struct net_device *dev;
1472
	struct net_device *last;
1473
	struct net *net;
L
Linus Torvalds 已提交
1474 1475 1476
	int err;

	rtnl_lock();
1477
	err = raw_notifier_chain_register(&netdev_chain, nb);
1478 1479
	if (err)
		goto unlock;
1480 1481 1482 1483
	if (dev_boot_phase)
		goto unlock;
	for_each_net(net) {
		for_each_netdev(net, dev) {
1484
			err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1485 1486 1487 1488 1489 1490
			err = notifier_to_errno(err);
			if (err)
				goto rollback;

			if (!(dev->flags & IFF_UP))
				continue;
L
Linus Torvalds 已提交
1491

1492
			call_netdevice_notifier(nb, NETDEV_UP, dev);
1493
		}
L
Linus Torvalds 已提交
1494
	}
1495 1496

unlock:
L
Linus Torvalds 已提交
1497 1498
	rtnl_unlock();
	return err;
1499 1500 1501

rollback:
	last = dev;
1502 1503 1504
	for_each_net(net) {
		for_each_netdev(net, dev) {
			if (dev == last)
1505
				goto outroll;
1506

1507
			if (dev->flags & IFF_UP) {
1508 1509 1510
				call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
							dev);
				call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1511
			}
1512
			call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1513 1514
		}
	}
1515

1516
outroll:
1517
	raw_notifier_chain_unregister(&netdev_chain, nb);
1518
	goto unlock;
L
Linus Torvalds 已提交
1519
}
E
Eric Dumazet 已提交
1520
EXPORT_SYMBOL(register_netdevice_notifier);
L
Linus Torvalds 已提交
1521 1522 1523 1524 1525 1526 1527 1528 1529

/**
 *	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.
1530 1531 1532 1533
 *
 * 	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
1534 1535 1536 1537
 */

int unregister_netdevice_notifier(struct notifier_block *nb)
{
1538 1539
	struct net_device *dev;
	struct net *net;
1540 1541 1542
	int err;

	rtnl_lock();
1543
	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1544 1545 1546 1547 1548 1549
	if (err)
		goto unlock;

	for_each_net(net) {
		for_each_netdev(net, dev) {
			if (dev->flags & IFF_UP) {
1550 1551 1552
				call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
							dev);
				call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1553
			}
1554
			call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1555 1556 1557
		}
	}
unlock:
1558 1559
	rtnl_unlock();
	return err;
L
Linus Torvalds 已提交
1560
}
E
Eric Dumazet 已提交
1561
EXPORT_SYMBOL(unregister_netdevice_notifier);
L
Linus Torvalds 已提交
1562

1563 1564 1565 1566 1567 1568 1569 1570 1571 1572
/**
 *	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
1573 1574 1575
static int call_netdevice_notifiers_info(unsigned long val,
					 struct net_device *dev,
					 struct netdev_notifier_info *info)
1576 1577 1578 1579 1580 1581
{
	ASSERT_RTNL();
	netdev_notifier_info_init(info, dev);
	return raw_notifier_call_chain(&netdev_chain, val, info);
}

L
Linus Torvalds 已提交
1582 1583 1584
/**
 *	call_netdevice_notifiers - call all network notifier blocks
 *      @val: value passed unmodified to notifier function
1585
 *      @dev: net_device pointer passed unmodified to notifier function
L
Linus Torvalds 已提交
1586 1587
 *
 *	Call all network notifier blocks.  Parameters and return value
1588
 *	are as for raw_notifier_call_chain().
L
Linus Torvalds 已提交
1589 1590
 */

1591
int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
L
Linus Torvalds 已提交
1592
{
1593 1594 1595
	struct netdev_notifier_info info;

	return call_netdevice_notifiers_info(val, dev, &info);
L
Linus Torvalds 已提交
1596
}
1597
EXPORT_SYMBOL(call_netdevice_notifiers);
L
Linus Torvalds 已提交
1598

1599
static struct static_key netstamp_needed __read_mostly;
1600
#ifdef HAVE_JUMP_LABEL
1601
/* We are not allowed to call static_key_slow_dec() from irq context
1602
 * If net_disable_timestamp() is called from irq context, defer the
1603
 * static_key_slow_dec() calls.
1604 1605 1606
 */
static atomic_t netstamp_needed_deferred;
#endif
L
Linus Torvalds 已提交
1607 1608 1609

void net_enable_timestamp(void)
{
1610 1611 1612 1613 1614
#ifdef HAVE_JUMP_LABEL
	int deferred = atomic_xchg(&netstamp_needed_deferred, 0);

	if (deferred) {
		while (--deferred)
1615
			static_key_slow_dec(&netstamp_needed);
1616 1617 1618
		return;
	}
#endif
1619
	static_key_slow_inc(&netstamp_needed);
L
Linus Torvalds 已提交
1620
}
E
Eric Dumazet 已提交
1621
EXPORT_SYMBOL(net_enable_timestamp);
L
Linus Torvalds 已提交
1622 1623 1624

void net_disable_timestamp(void)
{
1625 1626 1627 1628 1629 1630
#ifdef HAVE_JUMP_LABEL
	if (in_interrupt()) {
		atomic_inc(&netstamp_needed_deferred);
		return;
	}
#endif
1631
	static_key_slow_dec(&netstamp_needed);
L
Linus Torvalds 已提交
1632
}
E
Eric Dumazet 已提交
1633
EXPORT_SYMBOL(net_disable_timestamp);
L
Linus Torvalds 已提交
1634

E
Eric Dumazet 已提交
1635
static inline void net_timestamp_set(struct sk_buff *skb)
L
Linus Torvalds 已提交
1636
{
1637
	skb->tstamp.tv64 = 0;
1638
	if (static_key_false(&netstamp_needed))
1639
		__net_timestamp(skb);
L
Linus Torvalds 已提交
1640 1641
}

1642
#define net_timestamp_check(COND, SKB)			\
1643
	if (static_key_false(&netstamp_needed)) {		\
1644 1645 1646
		if ((COND) && !(SKB)->tstamp.tv64)	\
			__net_timestamp(SKB);		\
	}						\
E
Eric Dumazet 已提交
1647

1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668
static inline bool is_skb_forwardable(struct net_device *dev,
				      struct sk_buff *skb)
{
	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;
}

1669 1670 1671 1672 1673 1674 1675 1676
/**
 * dev_forward_skb - loopback an skb to another netif
 *
 * @dev: destination network device
 * @skb: buffer to forward
 *
 * return values:
 *	NET_RX_SUCCESS	(no congestion)
1677
 *	NET_RX_DROP     (packet was dropped, but freed)
1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688
 *
 * 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)
{
1689 1690 1691 1692 1693 1694 1695 1696
	if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {
		if (skb_copy_ubufs(skb, GFP_ATOMIC)) {
			atomic_long_inc(&dev->rx_dropped);
			kfree_skb(skb);
			return NET_RX_DROP;
		}
	}

1697
	if (unlikely(!is_skb_forwardable(dev, skb))) {
1698
		atomic_long_inc(&dev->rx_dropped);
1699
		kfree_skb(skb);
1700
		return NET_RX_DROP;
1701
	}
1702

1703
	skb_scrub_packet(skb, true);
1704
	skb->protocol = eth_type_trans(skb, dev);
1705

1706
	return netif_rx_internal(skb);
1707 1708 1709
}
EXPORT_SYMBOL_GPL(dev_forward_skb);

1710 1711 1712 1713
static inline int deliver_skb(struct sk_buff *skb,
			      struct packet_type *pt_prev,
			      struct net_device *orig_dev)
{
1714 1715
	if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
		return -ENOMEM;
1716 1717 1718 1719
	atomic_inc(&skb->users);
	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
}

1720 1721
static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
{
1722
	if (!ptype->af_packet_priv || !skb->sk)
1723 1724 1725 1726 1727 1728 1729 1730 1731 1732
		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
1733 1734 1735 1736 1737
/*
 *	Support routine. Sends outgoing frames to any network
 *	taps currently in use.
 */

1738
static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
L
Linus Torvalds 已提交
1739 1740
{
	struct packet_type *ptype;
1741 1742
	struct sk_buff *skb2 = NULL;
	struct packet_type *pt_prev = NULL;
1743

L
Linus Torvalds 已提交
1744 1745 1746 1747 1748 1749
	rcu_read_lock();
	list_for_each_entry_rcu(ptype, &ptype_all, list) {
		/* Never send packets back to the socket
		 * they originated from - MvS (miquels@drinkel.ow.org)
		 */
		if ((ptype->dev == dev || !ptype->dev) &&
1750
		    (!skb_loop_sk(ptype, skb))) {
1751 1752 1753 1754 1755 1756 1757
			if (pt_prev) {
				deliver_skb(skb2, pt_prev, skb->dev);
				pt_prev = ptype;
				continue;
			}

			skb2 = skb_clone(skb, GFP_ATOMIC);
L
Linus Torvalds 已提交
1758 1759 1760
			if (!skb2)
				break;

1761 1762
			net_timestamp_set(skb2);

L
Linus Torvalds 已提交
1763 1764 1765 1766
			/* skb->nh should be correctly
			   set by sender, so that the second statement is
			   just protection against buggy protocols.
			 */
1767
			skb_reset_mac_header(skb2);
L
Linus Torvalds 已提交
1768

1769
			if (skb_network_header(skb2) < skb2->data ||
1770
			    skb_network_header(skb2) > skb_tail_pointer(skb2)) {
1771 1772 1773
				net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
						     ntohs(skb2->protocol),
						     dev->name);
1774
				skb_reset_network_header(skb2);
L
Linus Torvalds 已提交
1775 1776
			}

1777
			skb2->transport_header = skb2->network_header;
L
Linus Torvalds 已提交
1778
			skb2->pkt_type = PACKET_OUTGOING;
1779
			pt_prev = ptype;
L
Linus Torvalds 已提交
1780 1781
		}
	}
1782 1783
	if (pt_prev)
		pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
L
Linus Torvalds 已提交
1784 1785 1786
	rcu_read_unlock();
}

1787 1788
/**
 * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799
 * @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
1800
static void netif_setup_tc(struct net_device *dev, unsigned int txq)
1801 1802 1803 1804 1805 1806
{
	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) {
1807
		pr_warn("Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
1808 1809 1810 1811 1812 1813 1814 1815 1816 1817
		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) {
1818 1819
			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);
1820 1821 1822 1823 1824
			netdev_set_prio_tc_map(dev, i, 0);
		}
	}
}

1825 1826 1827 1828 1829
#ifdef CONFIG_XPS
static DEFINE_MUTEX(xps_map_mutex);
#define xmap_dereference(P)		\
	rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))

1830 1831
static struct xps_map *remove_xps_queue(struct xps_dev_maps *dev_maps,
					int cpu, u16 index)
1832
{
1833 1834
	struct xps_map *map = NULL;
	int pos;
1835

1836 1837
	if (dev_maps)
		map = xmap_dereference(dev_maps->cpu_map[cpu]);
1838

1839 1840
	for (pos = 0; map && pos < map->len; pos++) {
		if (map->queues[pos] == index) {
1841 1842 1843
			if (map->len > 1) {
				map->queues[pos] = map->queues[--map->len];
			} else {
1844
				RCU_INIT_POINTER(dev_maps->cpu_map[cpu], NULL);
1845 1846 1847
				kfree_rcu(map, rcu);
				map = NULL;
			}
1848
			break;
1849 1850 1851
		}
	}

1852 1853 1854
	return map;
}

1855
static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
1856 1857
{
	struct xps_dev_maps *dev_maps;
1858
	int cpu, i;
1859 1860 1861 1862 1863 1864 1865 1866 1867
	bool active = false;

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

	if (!dev_maps)
		goto out_no_maps;

	for_each_possible_cpu(cpu) {
1868 1869 1870 1871 1872
		for (i = index; i < dev->num_tx_queues; i++) {
			if (!remove_xps_queue(dev_maps, cpu, i))
				break;
		}
		if (i == dev->num_tx_queues)
1873 1874 1875 1876
			active = true;
	}

	if (!active) {
1877 1878 1879 1880
		RCU_INIT_POINTER(dev->xps_maps, NULL);
		kfree_rcu(dev_maps, rcu);
	}

1881 1882 1883 1884
	for (i = index; i < dev->num_tx_queues; i++)
		netdev_queue_numa_node_write(netdev_get_tx_queue(dev, i),
					     NUMA_NO_NODE);

1885 1886 1887 1888
out_no_maps:
	mutex_unlock(&xps_map_mutex);
}

1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923
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;
}

1924 1925
int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
			u16 index)
1926
{
1927
	struct xps_dev_maps *dev_maps, *new_dev_maps = NULL;
1928 1929
	struct xps_map *map, *new_map;
	int maps_sz = max_t(unsigned int, XPS_DEV_MAPS_SIZE, L1_CACHE_BYTES);
1930 1931
	int cpu, numa_node_id = -2;
	bool active = false;
1932 1933 1934 1935 1936

	mutex_lock(&xps_map_mutex);

	dev_maps = xmap_dereference(dev->xps_maps);

1937 1938 1939 1940 1941 1942 1943
	/* allocate memory for queue storage */
	for_each_online_cpu(cpu) {
		if (!cpumask_test_cpu(cpu, mask))
			continue;

		if (!new_dev_maps)
			new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
1944 1945
		if (!new_dev_maps) {
			mutex_unlock(&xps_map_mutex);
1946
			return -ENOMEM;
1947
		}
1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961

		map = dev_maps ? xmap_dereference(dev_maps->cpu_map[cpu]) :
				 NULL;

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

		RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], map);
	}

	if (!new_dev_maps)
		goto out_no_new_maps;

1962
	for_each_possible_cpu(cpu) {
1963 1964 1965 1966 1967 1968 1969 1970 1971 1972
		if (cpumask_test_cpu(cpu, mask) && cpu_online(cpu)) {
			/* add queue to CPU maps */
			int pos = 0;

			map = xmap_dereference(new_dev_maps->cpu_map[cpu]);
			while ((pos < map->len) && (map->queues[pos] != index))
				pos++;

			if (pos == map->len)
				map->queues[map->len++] = index;
1973 1974 1975 1976 1977 1978
#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
1979 1980 1981 1982
		} else if (dev_maps) {
			/* fill in the new device map from the old device map */
			map = xmap_dereference(dev_maps->cpu_map[cpu]);
			RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], map);
1983
		}
1984

1985 1986
	}

1987 1988
	rcu_assign_pointer(dev->xps_maps, new_dev_maps);

1989
	/* Cleanup old maps */
1990 1991 1992 1993 1994 1995 1996
	if (dev_maps) {
		for_each_possible_cpu(cpu) {
			new_map = xmap_dereference(new_dev_maps->cpu_map[cpu]);
			map = xmap_dereference(dev_maps->cpu_map[cpu]);
			if (map && map != new_map)
				kfree_rcu(map, rcu);
		}
1997

1998
		kfree_rcu(dev_maps, rcu);
1999 2000
	}

2001 2002
	dev_maps = new_dev_maps;
	active = true;
2003

2004 2005
out_no_new_maps:
	/* update Tx queue numa node */
2006 2007 2008 2009
	netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
				     (numa_node_id >= 0) ? numa_node_id :
				     NUMA_NO_NODE);

2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028
	if (!dev_maps)
		goto out_no_maps;

	/* removes queue from unused CPUs */
	for_each_possible_cpu(cpu) {
		if (cpumask_test_cpu(cpu, mask) && cpu_online(cpu))
			continue;

		if (remove_xps_queue(dev_maps, cpu, index))
			active = true;
	}

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

out_no_maps:
2029 2030 2031 2032
	mutex_unlock(&xps_map_mutex);

	return 0;
error:
2033 2034 2035 2036 2037 2038 2039 2040 2041
	/* remove any maps that we added */
	for_each_possible_cpu(cpu) {
		new_map = xmap_dereference(new_dev_maps->cpu_map[cpu]);
		map = dev_maps ? xmap_dereference(dev_maps->cpu_map[cpu]) :
				 NULL;
		if (new_map && new_map != map)
			kfree(new_map);
	}

2042 2043 2044 2045 2046 2047 2048 2049
	mutex_unlock(&xps_map_mutex);

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

#endif
2050 2051 2052 2053
/*
 * 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.
 */
2054
int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2055
{
T
Tom Herbert 已提交
2056 2057
	int rc;

2058 2059
	if (txq < 1 || txq > dev->num_tx_queues)
		return -EINVAL;
2060

2061 2062
	if (dev->reg_state == NETREG_REGISTERED ||
	    dev->reg_state == NETREG_UNREGISTERING) {
2063 2064
		ASSERT_RTNL();

T
Tom Herbert 已提交
2065 2066
		rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
						  txq);
T
Tom Herbert 已提交
2067 2068 2069
		if (rc)
			return rc;

2070 2071 2072
		if (dev->num_tc)
			netif_setup_tc(dev, txq);

2073
		if (txq < dev->real_num_tx_queues) {
2074
			qdisc_reset_all_tx_gt(dev, txq);
2075 2076 2077 2078
#ifdef CONFIG_XPS
			netif_reset_xps_queues_gt(dev, txq);
#endif
		}
2079
	}
2080 2081 2082

	dev->real_num_tx_queues = txq;
	return 0;
2083 2084
}
EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2085

2086
#ifdef CONFIG_SYSFS
2087 2088 2089 2090 2091 2092 2093
/**
 *	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
2094 2095
 *	negative error code.  If called before registration, it always
 *	succeeds.
2096 2097 2098 2099 2100
 */
int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
{
	int rc;

T
Tom Herbert 已提交
2101 2102 2103
	if (rxq < 1 || rxq > dev->num_rx_queues)
		return -EINVAL;

2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118
	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

2119 2120
/**
 * netif_get_num_default_rss_queues - default number of RSS queues
2121 2122 2123 2124
 *
 * This routine should set an upper limit on the number of RSS queues
 * used by default by multiqueue devices.
 */
2125
int netif_get_num_default_rss_queues(void)
2126 2127 2128 2129 2130
{
	return min_t(int, DEFAULT_MAX_NUM_RSS_QUEUES, num_online_cpus());
}
EXPORT_SYMBOL(netif_get_num_default_rss_queues);

2131
static inline void __netif_reschedule(struct Qdisc *q)
2132
{
2133 2134
	struct softnet_data *sd;
	unsigned long flags;
2135

2136 2137
	local_irq_save(flags);
	sd = &__get_cpu_var(softnet_data);
2138 2139 2140
	q->next_sched = NULL;
	*sd->output_queue_tailp = q;
	sd->output_queue_tailp = &q->next_sched;
2141 2142 2143 2144 2145 2146 2147 2148
	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);
2149 2150 2151
}
EXPORT_SYMBOL(__netif_schedule);

2152 2153 2154 2155 2156 2157 2158 2159 2160 2161
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)
{
	return (struct dev_kfree_skb_cb *)skb->cb;
}

void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason)
2162
{
2163
	unsigned long flags;
2164

2165 2166 2167 2168 2169
	if (likely(atomic_read(&skb->users) == 1)) {
		smp_rmb();
		atomic_set(&skb->users, 0);
	} else if (likely(!atomic_dec_and_test(&skb->users))) {
		return;
2170
	}
2171 2172 2173 2174 2175 2176
	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);
2177
}
2178
EXPORT_SYMBOL(__dev_kfree_skb_irq);
2179

2180
void __dev_kfree_skb_any(struct sk_buff *skb, enum skb_free_reason reason)
2181 2182
{
	if (in_irq() || irqs_disabled())
2183
		__dev_kfree_skb_irq(skb, reason);
2184 2185 2186
	else
		dev_kfree_skb(skb);
}
2187
EXPORT_SYMBOL(__dev_kfree_skb_any);
2188 2189


2190 2191 2192 2193 2194 2195
/**
 * netif_device_detach - mark device as removed
 * @dev: network device
 *
 * Mark device as removed from system and therefore no longer available.
 */
2196 2197 2198 2199
void netif_device_detach(struct net_device *dev)
{
	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
	    netif_running(dev)) {
2200
		netif_tx_stop_all_queues(dev);
2201 2202 2203 2204
	}
}
EXPORT_SYMBOL(netif_device_detach);

2205 2206 2207 2208 2209 2210
/**
 * netif_device_attach - mark device as attached
 * @dev: network device
 *
 * Mark device as attached from system and restart if needed.
 */
2211 2212 2213 2214
void netif_device_attach(struct net_device *dev)
{
	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
	    netif_running(dev)) {
2215
		netif_tx_wake_all_queues(dev);
2216
		__netdev_watchdog_up(dev);
2217 2218 2219 2220
	}
}
EXPORT_SYMBOL(netif_device_attach);

2221 2222
static void skb_warn_bad_offload(const struct sk_buff *skb)
{
2223
	static const netdev_features_t null_features = 0;
2224 2225 2226
	struct net_device *dev = skb->dev;
	const char *driver = "";

2227 2228 2229
	if (!net_ratelimit())
		return;

2230 2231 2232 2233 2234
	if (dev && dev->dev.parent)
		driver = dev_driver_string(dev->dev.parent);

	WARN(1, "%s: caps=(%pNF, %pNF) len=%d data_len=%d gso_size=%d "
	     "gso_type=%d ip_summed=%d\n",
2235 2236
	     driver, dev ? &dev->features : &null_features,
	     skb->sk ? &skb->sk->sk_route_caps : &null_features,
2237 2238 2239 2240
	     skb->len, skb->data_len, skb_shinfo(skb)->gso_size,
	     skb_shinfo(skb)->gso_type, skb->ip_summed);
}

L
Linus Torvalds 已提交
2241 2242 2243 2244
/*
 * Invalidate hardware checksum when packet is to be mangled, and
 * complete checksum manually on outgoing path.
 */
2245
int skb_checksum_help(struct sk_buff *skb)
L
Linus Torvalds 已提交
2246
{
2247
	__wsum csum;
2248
	int ret = 0, offset;
L
Linus Torvalds 已提交
2249

2250
	if (skb->ip_summed == CHECKSUM_COMPLETE)
2251 2252 2253
		goto out_set_summed;

	if (unlikely(skb_shinfo(skb)->gso_size)) {
2254 2255
		skb_warn_bad_offload(skb);
		return -EINVAL;
L
Linus Torvalds 已提交
2256 2257
	}

2258 2259 2260 2261 2262 2263 2264 2265 2266
	/* 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;
	}

2267
	offset = skb_checksum_start_offset(skb);
2268 2269 2270 2271 2272 2273 2274 2275
	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
2276 2277 2278 2279 2280
		ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
		if (ret)
			goto out;
	}

2281
	*(__sum16 *)(skb->data + offset) = csum_fold(csum);
2282
out_set_summed:
L
Linus Torvalds 已提交
2283
	skb->ip_summed = CHECKSUM_NONE;
2284
out:
L
Linus Torvalds 已提交
2285 2286
	return ret;
}
E
Eric Dumazet 已提交
2287
EXPORT_SYMBOL(skb_checksum_help);
L
Linus Torvalds 已提交
2288

2289
__be16 skb_network_protocol(struct sk_buff *skb)
2290
{
A
Al Viro 已提交
2291
	__be16 type = skb->protocol;
2292
	int vlan_depth = ETH_HLEN;
2293

2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304
	/* 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;
	}

P
Patrick McHardy 已提交
2305
	while (type == htons(ETH_P_8021Q) || type == htons(ETH_P_8021AD)) {
2306
		struct vlan_hdr *vh;
2307

2308
		if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
2309
			return 0;
2310

2311 2312 2313
		vh = (struct vlan_hdr *)(skb->data + vlan_depth);
		type = vh->h_vlan_encapsulated_proto;
		vlan_depth += VLAN_HLEN;
2314 2315
	}

2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333
	return type;
}

/**
 *	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;
	__be16 type = skb_network_protocol(skb);

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

2334 2335 2336
	__skb_pull(skb, skb->mac_len);

	rcu_read_lock();
2337
	list_for_each_entry_rcu(ptype, &offload_base, list) {
2338
		if (ptype->type == type && ptype->callbacks.gso_segment) {
2339
			if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
2340 2341
				int err;

2342
				err = ptype->callbacks.gso_send_check(skb);
2343 2344 2345
				segs = ERR_PTR(err);
				if (err || skb_gso_ok(skb, features))
					break;
2346 2347
				__skb_push(skb, (skb->data -
						 skb_network_header(skb)));
2348
			}
2349
			segs = ptype->callbacks.gso_segment(skb, features);
2350 2351 2352 2353 2354
			break;
		}
	}
	rcu_read_unlock();

2355
	__skb_push(skb, skb->data - skb_mac_header(skb));
2356

2357 2358
	return segs;
}
2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395
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.
 */
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);

		if (skb_header_cloned(skb) &&
		    (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
			return ERR_PTR(err);
	}

2396
	SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
2397 2398
	SKB_GSO_CB(skb)->encap_level = 0;

2399 2400 2401 2402 2403
	skb_reset_mac_header(skb);
	skb_reset_mac_len(skb);

	return skb_mac_gso_segment(skb, features);
}
2404
EXPORT_SYMBOL(__skb_gso_segment);
2405

2406 2407 2408 2409 2410
/* Take action when hardware reception checksum errors are detected. */
#ifdef CONFIG_BUG
void netdev_rx_csum_fault(struct net_device *dev)
{
	if (net_ratelimit()) {
2411
		pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
2412 2413 2414 2415 2416 2417
		dump_stack();
	}
}
EXPORT_SYMBOL(netdev_rx_csum_fault);
#endif

L
Linus Torvalds 已提交
2418 2419 2420 2421 2422
/* 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.
 */

E
Eric Dumazet 已提交
2423
static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
L
Linus Torvalds 已提交
2424
{
2425
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2426
	int i;
2427
	if (!(dev->features & NETIF_F_HIGHDMA)) {
2428 2429 2430
		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)))
2431
				return 1;
2432
		}
2433
	}
L
Linus Torvalds 已提交
2434

2435 2436
	if (PCI_DMA_BUS_IS_PHYS) {
		struct device *pdev = dev->dev.parent;
L
Linus Torvalds 已提交
2437

E
Eric Dumazet 已提交
2438 2439
		if (!pdev)
			return 0;
2440
		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
2441 2442
			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
			dma_addr_t addr = page_to_phys(skb_frag_page(frag));
2443 2444 2445 2446
			if (!pdev->dma_mask || addr + PAGE_SIZE - 1 > *pdev->dma_mask)
				return 1;
		}
	}
2447
#endif
L
Linus Torvalds 已提交
2448 2449 2450
	return 0;
}

2451 2452 2453 2454 2455 2456 2457 2458 2459 2460
struct dev_gso_cb {
	void (*destructor)(struct sk_buff *skb);
};

#define DEV_GSO_CB(skb) ((struct dev_gso_cb *)(skb)->cb)

static void dev_gso_skb_destructor(struct sk_buff *skb)
{
	struct dev_gso_cb *cb;

E
Eric Dumazet 已提交
2461 2462
	kfree_skb_list(skb->next);
	skb->next = NULL;
2463 2464 2465 2466 2467 2468 2469 2470 2471

	cb = DEV_GSO_CB(skb);
	if (cb->destructor)
		cb->destructor(skb);
}

/**
 *	dev_gso_segment - Perform emulated hardware segmentation on skb.
 *	@skb: buffer to segment
2472
 *	@features: device features as applicable to this skb
2473 2474 2475 2476
 *
 *	This function segments the given skb and stores the list of segments
 *	in skb->next.
 */
2477
static int dev_gso_segment(struct sk_buff *skb, netdev_features_t features)
2478 2479
{
	struct sk_buff *segs;
2480 2481 2482 2483 2484 2485

	segs = skb_gso_segment(skb, features);

	/* Verifying header integrity only. */
	if (!segs)
		return 0;
2486

2487
	if (IS_ERR(segs))
2488 2489 2490 2491 2492 2493 2494 2495 2496
		return PTR_ERR(segs);

	skb->next = segs;
	DEV_GSO_CB(skb)->destructor = skb->destructor;
	skb->destructor = dev_gso_skb_destructor;

	return 0;
}

2497
static netdev_features_t harmonize_features(struct sk_buff *skb,
2498
	netdev_features_t features)
2499
{
2500
	if (skb->ip_summed != CHECKSUM_NONE &&
2501
	    !can_checksum_protocol(features, skb_network_protocol(skb))) {
2502 2503 2504 2505 2506 2507 2508 2509
		features &= ~NETIF_F_ALL_CSUM;
	} else if (illegal_highdma(skb->dev, skb)) {
		features &= ~NETIF_F_SG;
	}

	return features;
}

2510
netdev_features_t netif_skb_features(struct sk_buff *skb)
2511 2512
{
	__be16 protocol = skb->protocol;
2513
	netdev_features_t features = skb->dev->features;
2514

2515 2516 2517
	if (skb_shinfo(skb)->gso_segs > skb->dev->gso_max_segs)
		features &= ~NETIF_F_GSO_MASK;

P
Patrick McHardy 已提交
2518
	if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD)) {
2519 2520
		struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
		protocol = veh->h_vlan_encapsulated_proto;
2521
	} else if (!vlan_tx_tag_present(skb)) {
2522
		return harmonize_features(skb, features);
2523
	}
2524

P
Patrick McHardy 已提交
2525 2526
	features &= (skb->dev->vlan_features | NETIF_F_HW_VLAN_CTAG_TX |
					       NETIF_F_HW_VLAN_STAG_TX);
2527

2528
	if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD))
2529
		features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
P
Patrick McHardy 已提交
2530 2531
				NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_CTAG_TX |
				NETIF_F_HW_VLAN_STAG_TX;
2532 2533

	return harmonize_features(skb, features);
2534
}
2535
EXPORT_SYMBOL(netif_skb_features);
2536

2537
int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
2538
			struct netdev_queue *txq)
2539
{
2540
	const struct net_device_ops *ops = dev->netdev_ops;
2541
	int rc = NETDEV_TX_OK;
2542
	unsigned int skb_len;
2543

2544
	if (likely(!skb->next)) {
2545
		netdev_features_t features;
2546

2547
		/*
L
Lucas De Marchi 已提交
2548
		 * If device doesn't need skb->dst, release it right now while
2549 2550
		 * its hot in this cpu cache
		 */
E
Eric Dumazet 已提交
2551 2552 2553
		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
			skb_dst_drop(skb);

2554 2555
		features = netif_skb_features(skb);

2556
		if (vlan_tx_tag_present(skb) &&
2557 2558 2559
		    !vlan_hw_offload_capable(features, skb->vlan_proto)) {
			skb = __vlan_put_tag(skb, skb->vlan_proto,
					     vlan_tx_tag_get(skb));
2560 2561 2562 2563 2564 2565
			if (unlikely(!skb))
				goto out;

			skb->vlan_tci = 0;
		}

2566 2567 2568 2569 2570 2571 2572
		/* 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;

2573
		if (netif_needs_gso(skb, features)) {
2574
			if (unlikely(dev_gso_segment(skb, features)))
2575 2576 2577
				goto out_kfree_skb;
			if (skb->next)
				goto gso;
2578
		} else {
2579
			if (skb_needs_linearize(skb, features) &&
2580 2581 2582 2583 2584 2585 2586 2587
			    __skb_linearize(skb))
				goto out_kfree_skb;

			/* If packet is not checksummed and device does not
			 * support checksumming for this protocol, complete
			 * checksumming here.
			 */
			if (skb->ip_summed == CHECKSUM_PARTIAL) {
2588 2589 2590 2591 2592 2593
				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));
2594
				if (!(features & NETIF_F_ALL_CSUM) &&
2595 2596 2597
				     skb_checksum_help(skb))
					goto out_kfree_skb;
			}
2598 2599
		}

2600 2601 2602
		if (!list_empty(&ptype_all))
			dev_queue_xmit_nit(skb, dev);

2603
		skb_len = skb->len;
2604
		trace_net_dev_start_xmit(skb, dev);
2605
		rc = ops->ndo_start_xmit(skb, dev);
2606
		trace_net_dev_xmit(skb, rc, dev, skb_len);
2607
		if (rc == NETDEV_TX_OK)
E
Eric Dumazet 已提交
2608
			txq_trans_update(txq);
2609
		return rc;
2610 2611
	}

2612
gso:
2613 2614 2615 2616 2617
	do {
		struct sk_buff *nskb = skb->next;

		skb->next = nskb->next;
		nskb->next = NULL;
2618

2619 2620 2621
		if (!list_empty(&ptype_all))
			dev_queue_xmit_nit(nskb, dev);

2622
		skb_len = nskb->len;
2623
		trace_net_dev_start_xmit(nskb, dev);
2624
		rc = ops->ndo_start_xmit(nskb, dev);
2625
		trace_net_dev_xmit(nskb, rc, dev, skb_len);
2626
		if (unlikely(rc != NETDEV_TX_OK)) {
2627 2628
			if (rc & ~NETDEV_TX_MASK)
				goto out_kfree_gso_skb;
2629
			nskb->next = skb->next;
2630 2631 2632
			skb->next = nskb;
			return rc;
		}
E
Eric Dumazet 已提交
2633
		txq_trans_update(txq);
2634
		if (unlikely(netif_xmit_stopped(txq) && skb->next))
2635
			return NETDEV_TX_BUSY;
2636
	} while (skb->next);
2637

2638
out_kfree_gso_skb:
2639
	if (likely(skb->next == NULL)) {
2640
		skb->destructor = DEV_GSO_CB(skb)->destructor;
2641 2642 2643
		consume_skb(skb);
		return rc;
	}
2644 2645
out_kfree_skb:
	kfree_skb(skb);
2646
out:
2647
	return rc;
2648
}
2649
EXPORT_SYMBOL_GPL(dev_hard_start_xmit);
2650

2651 2652 2653 2654 2655 2656 2657 2658 2659 2660
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)  {
2661
		unsigned int hdr_len;
2662
		u16 gso_segs = shinfo->gso_segs;
2663

2664 2665 2666 2667
		/* mac layer + network layer */
		hdr_len = skb_transport_header(skb) - skb_mac_header(skb);

		/* + transport layer */
2668 2669 2670 2671
		if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
			hdr_len += tcp_hdrlen(skb);
		else
			hdr_len += sizeof(struct udphdr);
2672 2673 2674 2675 2676 2677

		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;
2678 2679 2680
	}
}

2681 2682 2683 2684 2685
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);
E
Eric Dumazet 已提交
2686
	bool contended;
2687 2688
	int rc;

2689
	qdisc_pkt_len_init(skb);
E
Eric Dumazet 已提交
2690
	qdisc_calculate_pkt_len(skb, q);
2691 2692 2693 2694 2695 2696
	/*
	 * Heuristic to force contended enqueues to serialize on a
	 * separate lock before trying to get qdisc main lock.
	 * This permits __QDISC_STATE_RUNNING owner to get the lock more often
	 * and dequeue packets faster.
	 */
E
Eric Dumazet 已提交
2697
	contended = qdisc_is_running(q);
2698 2699 2700
	if (unlikely(contended))
		spin_lock(&q->busylock);

2701 2702 2703 2704 2705
	spin_lock(root_lock);
	if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
		kfree_skb(skb);
		rc = NET_XMIT_DROP;
	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
2706
		   qdisc_run_begin(q)) {
2707 2708 2709 2710 2711
		/*
		 * 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.
		 */
E
Eric Dumazet 已提交
2712 2713
		if (!(dev->priv_flags & IFF_XMIT_DST_RELEASE))
			skb_dst_force(skb);
2714 2715 2716

		qdisc_bstats_update(q, skb);

2717 2718 2719 2720 2721
		if (sch_direct_xmit(skb, q, dev, txq, root_lock)) {
			if (unlikely(contended)) {
				spin_unlock(&q->busylock);
				contended = false;
			}
2722
			__qdisc_run(q);
2723
		} else
2724
			qdisc_run_end(q);
2725 2726 2727

		rc = NET_XMIT_SUCCESS;
	} else {
E
Eric Dumazet 已提交
2728
		skb_dst_force(skb);
E
Eric Dumazet 已提交
2729
		rc = q->enqueue(skb, q) & NET_XMIT_MASK;
2730 2731 2732 2733 2734 2735 2736
		if (qdisc_run_begin(q)) {
			if (unlikely(contended)) {
				spin_unlock(&q->busylock);
				contended = false;
			}
			__qdisc_run(q);
		}
2737 2738
	}
	spin_unlock(root_lock);
2739 2740
	if (unlikely(contended))
		spin_unlock(&q->busylock);
2741 2742 2743
	return rc;
}

2744
#if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
2745 2746
static void skb_update_prio(struct sk_buff *skb)
{
I
Igor Maravic 已提交
2747
	struct netprio_map *map = rcu_dereference_bh(skb->dev->priomap);
2748

2749 2750 2751 2752 2753 2754
	if (!skb->priority && skb->sk && map) {
		unsigned int prioidx = skb->sk->sk_cgrp_prioidx;

		if (prioidx < map->priomap_len)
			skb->priority = map->priomap[prioidx];
	}
2755 2756 2757 2758 2759
}
#else
#define skb_update_prio(skb)
#endif

2760
static DEFINE_PER_CPU(int, xmit_recursion);
2761
#define RECURSION_LIMIT 10
2762

2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779
/**
 *	dev_loopback_xmit - loop back @skb
 *	@skb: buffer to transmit
 */
int dev_loopback_xmit(struct sk_buff *skb)
{
	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);

2780
/**
2781
 *	__dev_queue_xmit - transmit a buffer
2782
 *	@skb: buffer to transmit
2783
 *	@accel_priv: private data used for L2 forwarding offload
2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805
 *
 *	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
 */
2806
int __dev_queue_xmit(struct sk_buff *skb, void *accel_priv)
L
Linus Torvalds 已提交
2807 2808
{
	struct net_device *dev = skb->dev;
2809
	struct netdev_queue *txq;
L
Linus Torvalds 已提交
2810 2811 2812
	struct Qdisc *q;
	int rc = -ENOMEM;

2813 2814
	skb_reset_mac_header(skb);

2815 2816
	/* Disable soft irqs for various locks below. Also
	 * stops preemption for RCU.
L
Linus Torvalds 已提交
2817
	 */
2818
	rcu_read_lock_bh();
L
Linus Torvalds 已提交
2819

2820 2821
	skb_update_prio(skb);

2822
	txq = netdev_pick_tx(dev, skb, accel_priv);
2823
	q = rcu_dereference_bh(txq->qdisc);
2824

L
Linus Torvalds 已提交
2825
#ifdef CONFIG_NET_CLS_ACT
E
Eric Dumazet 已提交
2826
	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_EGRESS);
L
Linus Torvalds 已提交
2827
#endif
2828
	trace_net_dev_queue(skb);
L
Linus Torvalds 已提交
2829
	if (q->enqueue) {
2830
		rc = __dev_xmit_skb(skb, q, dev, txq);
2831
		goto out;
L
Linus Torvalds 已提交
2832 2833 2834 2835 2836
	}

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

H
Herbert Xu 已提交
2837 2838
	   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
2839 2840 2841 2842 2843 2844 2845 2846 2847 2848
	   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 */

2849
		if (txq->xmit_lock_owner != cpu) {
L
Linus Torvalds 已提交
2850

2851 2852 2853
			if (__this_cpu_read(xmit_recursion) > RECURSION_LIMIT)
				goto recursion_alert;

2854
			HARD_TX_LOCK(dev, txq, cpu);
L
Linus Torvalds 已提交
2855

2856
			if (!netif_xmit_stopped(txq)) {
2857
				__this_cpu_inc(xmit_recursion);
2858
				rc = dev_hard_start_xmit(skb, dev, txq);
2859
				__this_cpu_dec(xmit_recursion);
2860
				if (dev_xmit_complete(rc)) {
2861
					HARD_TX_UNLOCK(dev, txq);
L
Linus Torvalds 已提交
2862 2863 2864
					goto out;
				}
			}
2865
			HARD_TX_UNLOCK(dev, txq);
2866 2867
			net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
					     dev->name);
L
Linus Torvalds 已提交
2868 2869
		} else {
			/* Recursion is detected! It is possible,
2870 2871 2872
			 * unfortunately
			 */
recursion_alert:
2873 2874
			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
					     dev->name);
L
Linus Torvalds 已提交
2875 2876 2877 2878
		}
	}

	rc = -ENETDOWN;
2879
	rcu_read_unlock_bh();
L
Linus Torvalds 已提交
2880 2881 2882 2883

	kfree_skb(skb);
	return rc;
out:
2884
	rcu_read_unlock_bh();
L
Linus Torvalds 已提交
2885 2886
	return rc;
}
2887 2888 2889 2890 2891

int dev_queue_xmit(struct sk_buff *skb)
{
	return __dev_queue_xmit(skb, NULL);
}
E
Eric Dumazet 已提交
2892
EXPORT_SYMBOL(dev_queue_xmit);
L
Linus Torvalds 已提交
2893

2894 2895 2896 2897 2898 2899
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
2900 2901 2902 2903 2904

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

2905
int netdev_max_backlog __read_mostly = 1000;
E
Eric Dumazet 已提交
2906 2907
EXPORT_SYMBOL(netdev_max_backlog);

E
Eric Dumazet 已提交
2908
int netdev_tstamp_prequeue __read_mostly = 1;
2909 2910
int netdev_budget __read_mostly = 300;
int weight_p __read_mostly = 64;            /* old backlog weight */
L
Linus Torvalds 已提交
2911

E
Eric Dumazet 已提交
2912 2913 2914 2915 2916 2917 2918 2919
/* 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);
}

2920 2921 2922
#ifdef CONFIG_RPS

/* One global table that all flow-based protocols share. */
E
Eric Dumazet 已提交
2923
struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
2924 2925
EXPORT_SYMBOL(rps_sock_flow_table);

2926
struct static_key rps_needed __read_mostly;
2927

2928 2929 2930 2931
static struct rps_dev_flow *
set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
	    struct rps_dev_flow *rflow, u16 next_cpu)
{
2932
	if (next_cpu != RPS_NO_CPU) {
2933 2934 2935 2936 2937 2938 2939 2940 2941
#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? */
2942 2943
		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
		    !(dev->features & NETIF_F_NTUPLE))
2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965
			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;
		flow_id = skb->rxhash & flow_table->mask;
		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 =
2966
			per_cpu(softnet_data, next_cpu).input_queue_head;
2967 2968
	}

2969
	rflow->cpu = next_cpu;
2970 2971 2972
	return rflow;
}

2973 2974 2975 2976 2977 2978 2979 2980 2981
/*
 * 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)
{
	struct netdev_rx_queue *rxqueue;
E
Eric Dumazet 已提交
2982
	struct rps_map *map;
2983 2984 2985 2986 2987 2988 2989
	struct rps_dev_flow_table *flow_table;
	struct rps_sock_flow_table *sock_flow_table;
	int cpu = -1;
	u16 tcpu;

	if (skb_rx_queue_recorded(skb)) {
		u16 index = skb_get_rx_queue(skb);
2990 2991 2992 2993 2994
		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);
2995 2996 2997 2998 2999 3000
			goto done;
		}
		rxqueue = dev->_rx + index;
	} else
		rxqueue = dev->_rx;

E
Eric Dumazet 已提交
3001 3002
	map = rcu_dereference(rxqueue->rps_map);
	if (map) {
3003
		if (map->len == 1 &&
3004
		    !rcu_access_pointer(rxqueue->rps_flow_table)) {
3005 3006 3007 3008 3009
			tcpu = map->cpus[0];
			if (cpu_online(tcpu))
				cpu = tcpu;
			goto done;
		}
3010
	} else if (!rcu_access_pointer(rxqueue->rps_flow_table)) {
3011
		goto done;
3012
	}
3013

3014
	skb_reset_network_header(skb);
3015
	if (!skb_get_hash(skb))
3016 3017
		goto done;

T
Tom Herbert 已提交
3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043
	flow_table = rcu_dereference(rxqueue->rps_flow_table);
	sock_flow_table = rcu_dereference(rps_sock_flow_table);
	if (flow_table && sock_flow_table) {
		u16 next_cpu;
		struct rps_dev_flow *rflow;

		rflow = &flow_table->flows[skb->rxhash & flow_table->mask];
		tcpu = rflow->cpu;

		next_cpu = sock_flow_table->ents[skb->rxhash &
		    sock_flow_table->mask];

		/*
		 * 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:
		 *   - Current CPU is unset (equal to RPS_NO_CPU).
		 *   - 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) &&
		    (tcpu == RPS_NO_CPU || !cpu_online(tcpu) ||
		     ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
3044 3045
		      rflow->last_qtail)) >= 0)) {
			tcpu = next_cpu;
3046
			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
3047
		}
3048

T
Tom Herbert 已提交
3049 3050 3051 3052 3053 3054 3055
		if (tcpu != RPS_NO_CPU && cpu_online(tcpu)) {
			*rflowp = rflow;
			cpu = tcpu;
			goto done;
		}
	}

T
Tom Herbert 已提交
3056
	if (map) {
T
Tom Herbert 已提交
3057
		tcpu = map->cpus[((u64) skb->rxhash * map->len) >> 32];
T
Tom Herbert 已提交
3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068

		if (cpu_online(tcpu)) {
			cpu = tcpu;
			goto done;
		}
	}

done:
	return cpu;
}

3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108
#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;
	int cpu;

	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);
		if (rflow->filter == filter_id && cpu != RPS_NO_CPU &&
		    ((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
3109
/* Called from hardirq (IPI) context */
E
Eric Dumazet 已提交
3110
static void rps_trigger_softirq(void *data)
T
Tom Herbert 已提交
3111
{
E
Eric Dumazet 已提交
3112 3113
	struct softnet_data *sd = data;

E
Eric Dumazet 已提交
3114
	____napi_schedule(sd, &sd->backlog);
C
Changli Gao 已提交
3115
	sd->received_rps++;
T
Tom Herbert 已提交
3116
}
E
Eric Dumazet 已提交
3117

T
Tom Herbert 已提交
3118
#endif /* CONFIG_RPS */
T
Tom Herbert 已提交
3119

E
Eric Dumazet 已提交
3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140
/*
 * 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
	struct softnet_data *mysd = &__get_cpu_var(softnet_data);

	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;
}

3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159
#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;

	sd = &__get_cpu_var(softnet_data);

	rcu_read_lock();
	fl = rcu_dereference(sd->flow_limit);
	if (fl) {
3160
		new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180
		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
3181 3182 3183 3184
/*
 * 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
3185 3186
static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
			      unsigned int *qtail)
T
Tom Herbert 已提交
3187
{
E
Eric Dumazet 已提交
3188
	struct softnet_data *sd;
T
Tom Herbert 已提交
3189
	unsigned long flags;
3190
	unsigned int qlen;
T
Tom Herbert 已提交
3191

E
Eric Dumazet 已提交
3192
	sd = &per_cpu(softnet_data, cpu);
T
Tom Herbert 已提交
3193 3194 3195

	local_irq_save(flags);

E
Eric Dumazet 已提交
3196
	rps_lock(sd);
3197 3198
	qlen = skb_queue_len(&sd->input_pkt_queue);
	if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) {
3199
		if (skb_queue_len(&sd->input_pkt_queue)) {
T
Tom Herbert 已提交
3200
enqueue:
E
Eric Dumazet 已提交
3201
			__skb_queue_tail(&sd->input_pkt_queue, skb);
3202
			input_queue_tail_incr_save(sd, qtail);
E
Eric Dumazet 已提交
3203
			rps_unlock(sd);
3204
			local_irq_restore(flags);
T
Tom Herbert 已提交
3205 3206 3207
			return NET_RX_SUCCESS;
		}

3208 3209 3210 3211
		/* 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
3212
			if (!rps_ipi_queued(sd))
E
Eric Dumazet 已提交
3213
				____napi_schedule(sd, &sd->backlog);
T
Tom Herbert 已提交
3214 3215 3216 3217
		}
		goto enqueue;
	}

C
Changli Gao 已提交
3218
	sd->dropped++;
E
Eric Dumazet 已提交
3219
	rps_unlock(sd);
T
Tom Herbert 已提交
3220 3221 3222

	local_irq_restore(flags);

3223
	atomic_long_inc(&skb->dev->rx_dropped);
T
Tom Herbert 已提交
3224 3225 3226
	kfree_skb(skb);
	return NET_RX_DROP;
}
L
Linus Torvalds 已提交
3227

3228
static int netif_rx_internal(struct sk_buff *skb)
L
Linus Torvalds 已提交
3229
{
3230
	int ret;
L
Linus Torvalds 已提交
3231 3232 3233 3234 3235

	/* if netpoll wants it, pretend we never saw it */
	if (netpoll_rx(skb))
		return NET_RX_DROP;

3236
	net_timestamp_check(netdev_tstamp_prequeue, skb);
L
Linus Torvalds 已提交
3237

3238
	trace_netif_rx(skb);
E
Eric Dumazet 已提交
3239
#ifdef CONFIG_RPS
3240
	if (static_key_false(&rps_needed)) {
T
Tom Herbert 已提交
3241
		struct rps_dev_flow voidflow, *rflow = &voidflow;
3242 3243
		int cpu;

3244
		preempt_disable();
3245
		rcu_read_lock();
T
Tom Herbert 已提交
3246 3247

		cpu = get_rps_cpu(skb->dev, skb, &rflow);
3248 3249
		if (cpu < 0)
			cpu = smp_processor_id();
T
Tom Herbert 已提交
3250 3251 3252

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

3253
		rcu_read_unlock();
3254
		preempt_enable();
3255 3256
	} else
#endif
T
Tom Herbert 已提交
3257 3258 3259 3260 3261
	{
		unsigned int qtail;
		ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
		put_cpu();
	}
3262
	return ret;
L
Linus Torvalds 已提交
3263
}
3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285

/**
 *	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
3286
EXPORT_SYMBOL(netif_rx);
L
Linus Torvalds 已提交
3287 3288 3289 3290 3291

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

3292 3293
	trace_netif_rx_ni_entry(skb);

L
Linus Torvalds 已提交
3294
	preempt_disable();
3295
	err = netif_rx_internal(skb);
L
Linus Torvalds 已提交
3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319
	if (local_softirq_pending())
		do_softirq();
	preempt_enable();

	return err;
}
EXPORT_SYMBOL(netif_rx_ni);

static void net_tx_action(struct softirq_action *h)
{
	struct softnet_data *sd = &__get_cpu_var(softnet_data);

	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;

3320
			WARN_ON(atomic_read(&skb->users));
3321 3322 3323 3324
			if (likely(get_kfree_skb_cb(skb)->reason == SKB_REASON_CONSUMED))
				trace_consume_skb(skb);
			else
				trace_kfree_skb(skb, net_tx_action);
L
Linus Torvalds 已提交
3325 3326 3327 3328 3329
			__kfree_skb(skb);
		}
	}

	if (sd->output_queue) {
3330
		struct Qdisc *head;
L
Linus Torvalds 已提交
3331 3332 3333 3334

		local_irq_disable();
		head = sd->output_queue;
		sd->output_queue = NULL;
3335
		sd->output_queue_tailp = &sd->output_queue;
L
Linus Torvalds 已提交
3336 3337 3338
		local_irq_enable();

		while (head) {
3339 3340 3341
			struct Qdisc *q = head;
			spinlock_t *root_lock;

L
Linus Torvalds 已提交
3342 3343
			head = head->next_sched;

3344
			root_lock = qdisc_lock(q);
3345
			if (spin_trylock(root_lock)) {
3346 3347 3348
				smp_mb__before_clear_bit();
				clear_bit(__QDISC_STATE_SCHED,
					  &q->state);
3349 3350
				qdisc_run(q);
				spin_unlock(root_lock);
L
Linus Torvalds 已提交
3351
			} else {
3352
				if (!test_bit(__QDISC_STATE_DEACTIVATED,
3353
					      &q->state)) {
3354
					__netif_reschedule(q);
3355 3356 3357 3358 3359
				} else {
					smp_mb__before_clear_bit();
					clear_bit(__QDISC_STATE_SCHED,
						  &q->state);
				}
L
Linus Torvalds 已提交
3360 3361 3362 3363 3364
			}
		}
	}
}

3365 3366
#if (defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)) && \
    (defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE))
3367 3368 3369
/* This hook is defined here for ATM LANE */
int (*br_fdb_test_addr_hook)(struct net_device *dev,
			     unsigned char *addr) __read_mostly;
3370
EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
3371
#endif
L
Linus Torvalds 已提交
3372 3373 3374 3375 3376 3377

#ifdef CONFIG_NET_CLS_ACT
/* TODO: Maybe we should just force sch_ingress to be compiled in
 * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
 * a compare and 2 stores extra right now if we dont have it on
 * but have CONFIG_NET_CLS_ACT
L
Lucas De Marchi 已提交
3378 3379
 * NOTE: This doesn't stop any functionality; if you dont have
 * the ingress scheduler, you just can't add policies on ingress.
L
Linus Torvalds 已提交
3380 3381
 *
 */
3382
static int ing_filter(struct sk_buff *skb, struct netdev_queue *rxq)
L
Linus Torvalds 已提交
3383 3384
{
	struct net_device *dev = skb->dev;
3385
	u32 ttl = G_TC_RTTL(skb->tc_verd);
3386 3387
	int result = TC_ACT_OK;
	struct Qdisc *q;
3388

3389
	if (unlikely(MAX_RED_LOOP < ttl++)) {
3390 3391
		net_warn_ratelimited("Redir loop detected Dropping packet (%d->%d)\n",
				     skb->skb_iif, dev->ifindex);
3392 3393
		return TC_ACT_SHOT;
	}
L
Linus Torvalds 已提交
3394

3395 3396
	skb->tc_verd = SET_TC_RTTL(skb->tc_verd, ttl);
	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS);
L
Linus Torvalds 已提交
3397

3398
	q = rxq->qdisc;
3399
	if (q != &noop_qdisc) {
3400
		spin_lock(qdisc_lock(q));
3401 3402
		if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))
			result = qdisc_enqueue_root(skb, q);
3403 3404
		spin_unlock(qdisc_lock(q));
	}
3405 3406 3407

	return result;
}
3408

3409 3410 3411 3412
static inline struct sk_buff *handle_ing(struct sk_buff *skb,
					 struct packet_type **pt_prev,
					 int *ret, struct net_device *orig_dev)
{
3413 3414 3415
	struct netdev_queue *rxq = rcu_dereference(skb->dev->ingress_queue);

	if (!rxq || rxq->qdisc == &noop_qdisc)
3416
		goto out;
L
Linus Torvalds 已提交
3417

3418 3419 3420
	if (*pt_prev) {
		*ret = deliver_skb(skb, *pt_prev, orig_dev);
		*pt_prev = NULL;
L
Linus Torvalds 已提交
3421 3422
	}

3423
	switch (ing_filter(skb, rxq)) {
3424 3425 3426 3427 3428 3429 3430 3431 3432
	case TC_ACT_SHOT:
	case TC_ACT_STOLEN:
		kfree_skb(skb);
		return NULL;
	}

out:
	skb->tc_verd = 0;
	return skb;
L
Linus Torvalds 已提交
3433 3434 3435
}
#endif

3436 3437 3438 3439
/**
 *	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
3440
 *	@rx_handler_data: data pointer that is used by rx handler
3441 3442 3443 3444 3445 3446
 *
 *	Register a receive hander for a device. This handler will then be
 *	called from __netif_receive_skb. A negative errno code is returned
 *	on a failure.
 *
 *	The caller must hold the rtnl_mutex.
3447 3448
 *
 *	For a general description of rx_handler, see enum rx_handler_result.
3449 3450
 */
int netdev_rx_handler_register(struct net_device *dev,
J
Jiri Pirko 已提交
3451 3452
			       rx_handler_func_t *rx_handler,
			       void *rx_handler_data)
3453 3454 3455 3456 3457 3458
{
	ASSERT_RTNL();

	if (dev->rx_handler)
		return -EBUSY;

3459
	/* Note: rx_handler_data must be set before rx_handler */
J
Jiri Pirko 已提交
3460
	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
3461 3462 3463 3464 3465 3466 3467 3468 3469 3470
	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
3471
 *	Unregister a receive handler from a device.
3472 3473 3474 3475 3476 3477 3478
 *
 *	The caller must hold the rtnl_mutex.
 */
void netdev_rx_handler_unregister(struct net_device *dev)
{

	ASSERT_RTNL();
3479
	RCU_INIT_POINTER(dev->rx_handler, NULL);
3480 3481 3482 3483 3484
	/* 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();
3485
	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
3486 3487 3488
}
EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);

3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499
/*
 * 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) {
	case __constant_htons(ETH_P_ARP):
	case __constant_htons(ETH_P_IP):
	case __constant_htons(ETH_P_IPV6):
	case __constant_htons(ETH_P_8021Q):
P
Patrick McHardy 已提交
3500
	case __constant_htons(ETH_P_8021AD):
3501 3502 3503 3504 3505 3506
		return true;
	default:
		return false;
	}
}

3507
static int __netif_receive_skb_core(struct sk_buff *skb, bool pfmemalloc)
L
Linus Torvalds 已提交
3508 3509
{
	struct packet_type *ptype, *pt_prev;
3510
	rx_handler_func_t *rx_handler;
D
David S. Miller 已提交
3511
	struct net_device *orig_dev;
3512
	struct net_device *null_or_dev;
3513
	bool deliver_exact = false;
L
Linus Torvalds 已提交
3514
	int ret = NET_RX_DROP;
A
Al Viro 已提交
3515
	__be16 type;
L
Linus Torvalds 已提交
3516

3517
	net_timestamp_check(!netdev_tstamp_prequeue, skb);
3518

3519
	trace_netif_receive_skb(skb);
3520

L
Linus Torvalds 已提交
3521
	/* if we've gotten here through NAPI, check netpoll */
3522
	if (netpoll_receive_skb(skb))
3523
		goto out;
L
Linus Torvalds 已提交
3524

J
Joe Eykholt 已提交
3525
	orig_dev = skb->dev;
3526

3527
	skb_reset_network_header(skb);
3528 3529
	if (!skb_transport_header_was_set(skb))
		skb_reset_transport_header(skb);
3530
	skb_reset_mac_len(skb);
L
Linus Torvalds 已提交
3531 3532 3533 3534 3535

	pt_prev = NULL;

	rcu_read_lock();

3536
another_round:
3537
	skb->skb_iif = skb->dev->ifindex;
3538 3539 3540

	__this_cpu_inc(softnet_data.processed);

P
Patrick McHardy 已提交
3541 3542
	if (skb->protocol == cpu_to_be16(ETH_P_8021Q) ||
	    skb->protocol == cpu_to_be16(ETH_P_8021AD)) {
3543 3544
		skb = vlan_untag(skb);
		if (unlikely(!skb))
3545
			goto unlock;
3546 3547
	}

L
Linus Torvalds 已提交
3548 3549 3550 3551 3552 3553 3554
#ifdef CONFIG_NET_CLS_ACT
	if (skb->tc_verd & TC_NCLS) {
		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
		goto ncls;
	}
#endif

3555
	if (pfmemalloc)
3556 3557
		goto skip_taps;

L
Linus Torvalds 已提交
3558
	list_for_each_entry_rcu(ptype, &ptype_all, list) {
3559
		if (!ptype->dev || ptype->dev == skb->dev) {
3560
			if (pt_prev)
D
David S. Miller 已提交
3561
				ret = deliver_skb(skb, pt_prev, orig_dev);
L
Linus Torvalds 已提交
3562 3563 3564 3565
			pt_prev = ptype;
		}
	}

3566
skip_taps:
L
Linus Torvalds 已提交
3567
#ifdef CONFIG_NET_CLS_ACT
3568 3569
	skb = handle_ing(skb, &pt_prev, &ret, orig_dev);
	if (!skb)
3570
		goto unlock;
L
Linus Torvalds 已提交
3571 3572 3573
ncls:
#endif

3574
	if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
3575 3576
		goto drop;

3577 3578 3579 3580 3581
	if (vlan_tx_tag_present(skb)) {
		if (pt_prev) {
			ret = deliver_skb(skb, pt_prev, orig_dev);
			pt_prev = NULL;
		}
3582
		if (vlan_do_receive(&skb))
3583 3584
			goto another_round;
		else if (unlikely(!skb))
3585
			goto unlock;
3586 3587
	}

3588
	rx_handler = rcu_dereference(skb->dev->rx_handler);
3589 3590 3591 3592 3593
	if (rx_handler) {
		if (pt_prev) {
			ret = deliver_skb(skb, pt_prev, orig_dev);
			pt_prev = NULL;
		}
3594 3595
		switch (rx_handler(&skb)) {
		case RX_HANDLER_CONSUMED:
3596
			ret = NET_RX_SUCCESS;
3597
			goto unlock;
3598
		case RX_HANDLER_ANOTHER:
3599
			goto another_round;
3600 3601 3602 3603 3604 3605 3606
		case RX_HANDLER_EXACT:
			deliver_exact = true;
		case RX_HANDLER_PASS:
			break;
		default:
			BUG();
		}
3607
	}
L
Linus Torvalds 已提交
3608

E
Eric Dumazet 已提交
3609 3610 3611 3612 3613 3614 3615 3616 3617
	if (unlikely(vlan_tx_tag_present(skb))) {
		if (vlan_tx_tag_get_id(skb))
			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;
	}
3618

3619
	/* deliver only exact match when indicated */
3620
	null_or_dev = deliver_exact ? skb->dev : NULL;
3621

L
Linus Torvalds 已提交
3622
	type = skb->protocol;
3623 3624
	list_for_each_entry_rcu(ptype,
			&ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
3625
		if (ptype->type == type &&
3626 3627
		    (ptype->dev == null_or_dev || ptype->dev == skb->dev ||
		     ptype->dev == orig_dev)) {
3628
			if (pt_prev)
D
David S. Miller 已提交
3629
				ret = deliver_skb(skb, pt_prev, orig_dev);
L
Linus Torvalds 已提交
3630 3631 3632 3633 3634
			pt_prev = ptype;
		}
	}

	if (pt_prev) {
3635
		if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
3636
			goto drop;
3637 3638
		else
			ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
L
Linus Torvalds 已提交
3639
	} else {
3640
drop:
3641
		atomic_long_inc(&skb->dev->rx_dropped);
L
Linus Torvalds 已提交
3642 3643 3644 3645 3646 3647 3648
		kfree_skb(skb);
		/* Jamal, now you will not able to escape explaining
		 * me how you were going to use this. :-)
		 */
		ret = NET_RX_DROP;
	}

3649
unlock:
L
Linus Torvalds 已提交
3650
	rcu_read_unlock();
3651
out:
3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676
	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
3677 3678
	return ret;
}
T
Tom Herbert 已提交
3679

3680
static int netif_receive_skb_internal(struct sk_buff *skb)
T
Tom Herbert 已提交
3681
{
3682
	net_timestamp_check(netdev_tstamp_prequeue, skb);
E
Eric Dumazet 已提交
3683

3684 3685 3686
	if (skb_defer_rx_timestamp(skb))
		return NET_RX_SUCCESS;

E
Eric Dumazet 已提交
3687
#ifdef CONFIG_RPS
3688
	if (static_key_false(&rps_needed)) {
E
Eric Dumazet 已提交
3689 3690
		struct rps_dev_flow voidflow, *rflow = &voidflow;
		int cpu, ret;
T
Tom Herbert 已提交
3691

E
Eric Dumazet 已提交
3692 3693 3694
		rcu_read_lock();

		cpu = get_rps_cpu(skb->dev, skb, &rflow);
T
Tom Herbert 已提交
3695

E
Eric Dumazet 已提交
3696 3697 3698
		if (cpu >= 0) {
			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
			rcu_read_unlock();
3699
			return ret;
E
Eric Dumazet 已提交
3700
		}
3701
		rcu_read_unlock();
T
Tom Herbert 已提交
3702
	}
3703
#endif
3704
	return __netif_receive_skb(skb);
T
Tom Herbert 已提交
3705
}
3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725 3726 3727

/**
 *	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
 */
int netif_receive_skb(struct sk_buff *skb)
{
	trace_netif_receive_skb_entry(skb);

	return netif_receive_skb_internal(skb);
}
E
Eric Dumazet 已提交
3728
EXPORT_SYMBOL(netif_receive_skb);
L
Linus Torvalds 已提交
3729

E
Eric Dumazet 已提交
3730 3731 3732
/* Network device is going away, flush any packets still pending
 * Called with irqs disabled.
 */
3733
static void flush_backlog(void *arg)
3734
{
3735
	struct net_device *dev = arg;
E
Eric Dumazet 已提交
3736
	struct softnet_data *sd = &__get_cpu_var(softnet_data);
3737 3738
	struct sk_buff *skb, *tmp;

E
Eric Dumazet 已提交
3739
	rps_lock(sd);
3740
	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
3741
		if (skb->dev == dev) {
E
Eric Dumazet 已提交
3742
			__skb_unlink(skb, &sd->input_pkt_queue);
3743
			kfree_skb(skb);
3744
			input_queue_head_incr(sd);
3745
		}
3746
	}
E
Eric Dumazet 已提交
3747
	rps_unlock(sd);
3748 3749 3750 3751 3752

	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
		if (skb->dev == dev) {
			__skb_unlink(skb, &sd->process_queue);
			kfree_skb(skb);
3753
			input_queue_head_incr(sd);
3754 3755
		}
	}
3756 3757
}

3758 3759
static int napi_gro_complete(struct sk_buff *skb)
{
3760
	struct packet_offload *ptype;
3761
	__be16 type = skb->protocol;
3762
	struct list_head *head = &offload_base;
3763 3764
	int err = -ENOENT;

3765 3766
	BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));

3767 3768
	if (NAPI_GRO_CB(skb)->count == 1) {
		skb_shinfo(skb)->gso_size = 0;
3769
		goto out;
3770
	}
3771 3772 3773

	rcu_read_lock();
	list_for_each_entry_rcu(ptype, head, list) {
3774
		if (ptype->type != type || !ptype->callbacks.gro_complete)
3775 3776
			continue;

3777
		err = ptype->callbacks.gro_complete(skb, 0);
3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788
		break;
	}
	rcu_read_unlock();

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

out:
3789
	return netif_receive_skb_internal(skb);
3790 3791
}

3792 3793 3794 3795 3796
/* 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)
3797
{
3798
	struct sk_buff *skb, *prev = NULL;
3799

3800 3801 3802 3803 3804 3805 3806
	/* 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) {
3807
		skb->next = NULL;
3808 3809 3810 3811 3812

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

		prev = skb->prev;
3813
		napi_gro_complete(skb);
3814
		napi->gro_count--;
3815 3816 3817 3818
	}

	napi->gro_list = NULL;
}
E
Eric Dumazet 已提交
3819
EXPORT_SYMBOL(napi_gro_flush);
3820

E
Eric Dumazet 已提交
3821 3822 3823 3824
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;
3825
	u32 hash = skb_get_hash_raw(skb);
E
Eric Dumazet 已提交
3826 3827 3828 3829

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

3830 3831 3832 3833 3834 3835 3836
		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
3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849
		diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
		diffs |= p->vlan_tci ^ skb->vlan_tci;
		if (maclen == ETH_HLEN)
			diffs |= compare_ether_header(skb_mac_header(p),
						      skb_gro_mac_header(skb));
		else if (!diffs)
			diffs = memcmp(skb_mac_header(p),
				       skb_gro_mac_header(skb),
				       maclen);
		NAPI_GRO_CB(p)->same_flow = !diffs;
	}
}

3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866
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);
		NAPI_GRO_CB(skb)->frag0_len = skb_frag_size(frag0);
	}
}

R
Rami Rosen 已提交
3867
static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3868 3869
{
	struct sk_buff **pp = NULL;
3870
	struct packet_offload *ptype;
3871
	__be16 type = skb->protocol;
3872
	struct list_head *head = &offload_base;
H
Herbert Xu 已提交
3873
	int same_flow;
3874
	enum gro_result ret;
3875

3876
	if (!(skb->dev->features & NETIF_F_GRO) || netpoll_rx_on(skb))
3877 3878
		goto normal;

3879
	if (skb_is_gso(skb) || skb_has_frag_list(skb))
3880 3881
		goto normal;

3882
	skb_gro_reset_offset(skb);
E
Eric Dumazet 已提交
3883
	gro_list_prepare(napi, skb);
3884
	NAPI_GRO_CB(skb)->csum = skb->csum; /* Needed for CHECKSUM_COMPLETE */
E
Eric Dumazet 已提交
3885

3886 3887
	rcu_read_lock();
	list_for_each_entry_rcu(ptype, head, list) {
3888
		if (ptype->type != type || !ptype->callbacks.gro_receive)
3889 3890
			continue;

3891
		skb_set_network_header(skb, skb_gro_offset(skb));
3892
		skb_reset_mac_len(skb);
3893 3894
		NAPI_GRO_CB(skb)->same_flow = 0;
		NAPI_GRO_CB(skb)->flush = 0;
H
Herbert Xu 已提交
3895
		NAPI_GRO_CB(skb)->free = 0;
3896
		NAPI_GRO_CB(skb)->udp_mark = 0;
3897

3898
		pp = ptype->callbacks.gro_receive(&napi->gro_list, skb);
3899 3900 3901 3902 3903 3904 3905
		break;
	}
	rcu_read_unlock();

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

H
Herbert Xu 已提交
3906
	same_flow = NAPI_GRO_CB(skb)->same_flow;
3907
	ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
H
Herbert Xu 已提交
3908

3909 3910 3911 3912 3913 3914
	if (pp) {
		struct sk_buff *nskb = *pp;

		*pp = nskb->next;
		nskb->next = NULL;
		napi_gro_complete(nskb);
3915
		napi->gro_count--;
3916 3917
	}

H
Herbert Xu 已提交
3918
	if (same_flow)
3919 3920
		goto ok;

3921
	if (NAPI_GRO_CB(skb)->flush)
3922 3923
		goto normal;

3924 3925 3926 3927 3928 3929 3930 3931 3932 3933 3934 3935 3936 3937
	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++;
	}
3938
	NAPI_GRO_CB(skb)->count = 1;
3939
	NAPI_GRO_CB(skb)->age = jiffies;
3940
	skb_shinfo(skb)->gso_size = skb_gro_len(skb);
3941 3942
	skb->next = napi->gro_list;
	napi->gro_list = skb;
3943
	ret = GRO_HELD;
3944

3945
pull:
H
Herbert Xu 已提交
3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956
	if (skb_headlen(skb) < skb_gro_offset(skb)) {
		int grow = skb_gro_offset(skb) - skb_headlen(skb);

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

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

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

		skb_shinfo(skb)->frags[0].page_offset += grow;
E
Eric Dumazet 已提交
3957
		skb_frag_size_sub(&skb_shinfo(skb)->frags[0], grow);
H
Herbert Xu 已提交
3958

E
Eric Dumazet 已提交
3959
		if (unlikely(!skb_frag_size(&skb_shinfo(skb)->frags[0]))) {
3960
			skb_frag_unref(skb, 0);
H
Herbert Xu 已提交
3961 3962
			memmove(skb_shinfo(skb)->frags,
				skb_shinfo(skb)->frags + 1,
3963
				--skb_shinfo(skb)->nr_frags * sizeof(skb_frag_t));
H
Herbert Xu 已提交
3964
		}
3965 3966
	}

3967
ok:
3968
	return ret;
3969 3970

normal:
3971 3972
	ret = GRO_NORMAL;
	goto pull;
H
Herbert Xu 已提交
3973
}
3974

3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999
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;
}

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;
}
H
Herbert Xu 已提交
4000

R
Rami Rosen 已提交
4001
static gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
H
Herbert Xu 已提交
4002
{
4003 4004
	switch (ret) {
	case GRO_NORMAL:
4005
		if (netif_receive_skb_internal(skb))
4006 4007
			ret = GRO_DROP;
		break;
H
Herbert Xu 已提交
4008

4009
	case GRO_DROP:
H
Herbert Xu 已提交
4010 4011
		kfree_skb(skb);
		break;
4012

4013
	case GRO_MERGED_FREE:
4014 4015 4016 4017
		if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
			kmem_cache_free(skbuff_head_cache, skb);
		else
			__kfree_skb(skb);
4018 4019
		break;

4020 4021 4022
	case GRO_HELD:
	case GRO_MERGED:
		break;
H
Herbert Xu 已提交
4023 4024
	}

4025
	return ret;
4026 4027
}

4028
gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
4029
{
4030 4031
	trace_napi_gro_receive_entry(skb);

E
Eric Dumazet 已提交
4032
	return napi_skb_finish(dev_gro_receive(napi, skb), skb);
4033 4034 4035
}
EXPORT_SYMBOL(napi_gro_receive);

S
stephen hemminger 已提交
4036
static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
4037 4038
{
	__skb_pull(skb, skb_headlen(skb));
4039 4040
	/* restore the reserve we had after netdev_alloc_skb_ip_align() */
	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
4041
	skb->vlan_tci = 0;
H
Herbert Xu 已提交
4042
	skb->dev = napi->dev;
A
Andy Gospodarek 已提交
4043
	skb->skb_iif = 0;
4044 4045 4046 4047

	napi->skb = skb;
}

4048
struct sk_buff *napi_get_frags(struct napi_struct *napi)
H
Herbert Xu 已提交
4049 4050 4051 4052
{
	struct sk_buff *skb = napi->skb;

	if (!skb) {
4053
		skb = netdev_alloc_skb_ip_align(napi->dev, GRO_MAX_HEAD);
E
Eric Dumazet 已提交
4054
		napi->skb = skb;
4055
	}
4056 4057
	return skb;
}
4058
EXPORT_SYMBOL(napi_get_frags);
4059

R
Rami Rosen 已提交
4060
static gro_result_t napi_frags_finish(struct napi_struct *napi, struct sk_buff *skb,
4061
			       gro_result_t ret)
4062
{
4063 4064
	switch (ret) {
	case GRO_NORMAL:
4065
		if (netif_receive_skb_internal(skb))
4066
			ret = GRO_DROP;
4067
		break;
H
Herbert Xu 已提交
4068

4069 4070 4071 4072
	case GRO_DROP:
	case GRO_MERGED_FREE:
		napi_reuse_skb(napi, skb);
		break;
4073

4074
	case GRO_HELD:
4075 4076
	case GRO_MERGED:
		break;
4077
	}
H
Herbert Xu 已提交
4078

4079
	return ret;
H
Herbert Xu 已提交
4080
}
4081

E
Eric Dumazet 已提交
4082
static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
4083 4084 4085 4086 4087
{
	struct sk_buff *skb = napi->skb;

	napi->skb = NULL;

4088 4089 4090
	if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr)))) {
		napi_reuse_skb(napi, skb);
		return NULL;
4091
	}
4092
	skb->protocol = eth_type_trans(skb, skb->dev);
4093 4094 4095 4096

	return skb;
}

4097
gro_result_t napi_gro_frags(struct napi_struct *napi)
4098
{
4099
	struct sk_buff *skb = napi_frags_skb(napi);
4100 4101

	if (!skb)
4102
		return GRO_DROP;
4103

4104 4105
	trace_napi_gro_frags_entry(skb);

E
Eric Dumazet 已提交
4106
	return napi_frags_finish(napi, skb, dev_gro_receive(napi, skb));
4107
}
H
Herbert Xu 已提交
4108 4109
EXPORT_SYMBOL(napi_gro_frags);

4110
/*
4111
 * net_rps_action_and_irq_enable sends any pending IPI's for rps.
4112 4113 4114 4115 4116 4117 4118 4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136 4137
 * 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))
				__smp_call_function_single(remsd->cpu,
							   &remsd->csd, 0);
			remsd = next;
		}
	} else
#endif
		local_irq_enable();
}

4138
static int process_backlog(struct napi_struct *napi, int quota)
L
Linus Torvalds 已提交
4139 4140
{
	int work = 0;
E
Eric Dumazet 已提交
4141
	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
L
Linus Torvalds 已提交
4142

4143 4144 4145 4146 4147 4148 4149 4150 4151
#ifdef CONFIG_RPS
	/* Check if we have pending ipi, its better to send them now,
	 * not waiting net_rx_action() end.
	 */
	if (sd->rps_ipi_list) {
		local_irq_disable();
		net_rps_action_and_irq_enable(sd);
	}
#endif
4152
	napi->weight = weight_p;
4153 4154
	local_irq_disable();
	while (work < quota) {
L
Linus Torvalds 已提交
4155
		struct sk_buff *skb;
4156 4157 4158 4159 4160 4161
		unsigned int qlen;

		while ((skb = __skb_dequeue(&sd->process_queue))) {
			local_irq_enable();
			__netif_receive_skb(skb);
			local_irq_disable();
4162 4163 4164 4165 4166
			input_queue_head_incr(sd);
			if (++work >= quota) {
				local_irq_enable();
				return work;
			}
4167
		}
L
Linus Torvalds 已提交
4168

E
Eric Dumazet 已提交
4169
		rps_lock(sd);
4170
		qlen = skb_queue_len(&sd->input_pkt_queue);
4171
		if (qlen)
4172 4173
			skb_queue_splice_tail_init(&sd->input_pkt_queue,
						   &sd->process_queue);
4174

4175
		if (qlen < quota - work) {
E
Eric Dumazet 已提交
4176 4177 4178 4179 4180 4181 4182 4183 4184 4185
			/*
			 * Inline a custom version of __napi_complete().
			 * only current cpu owns and manipulates this napi,
			 * and NAPI_STATE_SCHED is the only possible flag set on backlog.
			 * we can use a plain write instead of clear_bit(),
			 * and we dont need an smp_mb() memory barrier.
			 */
			list_del(&napi->poll_list);
			napi->state = 0;

4186
			quota = work + qlen;
4187
		}
E
Eric Dumazet 已提交
4188
		rps_unlock(sd);
4189 4190
	}
	local_irq_enable();
L
Linus Torvalds 已提交
4191

4192 4193
	return work;
}
L
Linus Torvalds 已提交
4194

4195 4196
/**
 * __napi_schedule - schedule for receive
4197
 * @n: entry to schedule
4198 4199 4200
 *
 * The entry's receive function will be scheduled to run
 */
H
Harvey Harrison 已提交
4201
void __napi_schedule(struct napi_struct *n)
4202 4203
{
	unsigned long flags;
L
Linus Torvalds 已提交
4204

4205
	local_irq_save(flags);
E
Eric Dumazet 已提交
4206
	____napi_schedule(&__get_cpu_var(softnet_data), n);
4207
	local_irq_restore(flags);
L
Linus Torvalds 已提交
4208
}
4209 4210
EXPORT_SYMBOL(__napi_schedule);

4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232
void __napi_complete(struct napi_struct *n)
{
	BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
	BUG_ON(n->gro_list);

	list_del(&n->poll_list);
	smp_mb__before_clear_bit();
	clear_bit(NAPI_STATE_SCHED, &n->state);
}
EXPORT_SYMBOL(__napi_complete);

void napi_complete(struct napi_struct *n)
{
	unsigned long flags;

	/*
	 * don't let napi dequeue from the cpu poll list
	 * just in case its running on a different cpu
	 */
	if (unlikely(test_bit(NAPI_STATE_NPSVC, &n->state)))
		return;

4233
	napi_gro_flush(n, false);
4234 4235 4236 4237 4238 4239
	local_irq_save(flags);
	__napi_complete(n);
	local_irq_restore(flags);
}
EXPORT_SYMBOL(napi_complete);

E
Eliezer Tamir 已提交
4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277 4278 4279 4280 4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291
/* must be called under rcu_read_lock(), as we dont take a reference */
struct napi_struct *napi_by_id(unsigned int napi_id)
{
	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;
}
EXPORT_SYMBOL_GPL(napi_by_id);

void napi_hash_add(struct napi_struct *napi)
{
	if (!test_and_set_bit(NAPI_STATE_HASHED, &napi->state)) {

		spin_lock(&napi_hash_lock);

		/* 0 is not a valid id, we also skip an id that is taken
		 * we expect both events to be extremely rare
		 */
		napi->napi_id = 0;
		while (!napi->napi_id) {
			napi->napi_id = ++napi_gen_id;
			if (napi_by_id(napi->napi_id))
				napi->napi_id = 0;
		}

		hlist_add_head_rcu(&napi->napi_hash_node,
			&napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);

		spin_unlock(&napi_hash_lock);
	}
}
EXPORT_SYMBOL_GPL(napi_hash_add);

/* Warning : caller is responsible to make sure rcu grace period
 * is respected before freeing memory containing @napi
 */
void napi_hash_del(struct napi_struct *napi)
{
	spin_lock(&napi_hash_lock);

	if (test_and_clear_bit(NAPI_STATE_HASHED, &napi->state))
		hlist_del_rcu(&napi->napi_hash_node);

	spin_unlock(&napi_hash_lock);
}
EXPORT_SYMBOL_GPL(napi_hash_del);

4292 4293 4294 4295
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);
4296
	napi->gro_count = 0;
4297
	napi->gro_list = NULL;
H
Herbert Xu 已提交
4298
	napi->skb = NULL;
4299
	napi->poll = poll;
E
Eric Dumazet 已提交
4300 4301 4302
	if (weight > NAPI_POLL_WEIGHT)
		pr_err_once("netif_napi_add() called with weight %d on device %s\n",
			    weight, dev->name);
4303 4304 4305
	napi->weight = weight;
	list_add(&napi->dev_list, &dev->napi_list);
	napi->dev = dev;
H
Herbert Xu 已提交
4306
#ifdef CONFIG_NETPOLL
4307 4308 4309 4310 4311 4312 4313 4314 4315
	spin_lock_init(&napi->poll_lock);
	napi->poll_owner = -1;
#endif
	set_bit(NAPI_STATE_SCHED, &napi->state);
}
EXPORT_SYMBOL(netif_napi_add);

void netif_napi_del(struct napi_struct *napi)
{
4316
	list_del_init(&napi->dev_list);
4317
	napi_free_frags(napi);
4318

E
Eric Dumazet 已提交
4319
	kfree_skb_list(napi->gro_list);
4320
	napi->gro_list = NULL;
4321
	napi->gro_count = 0;
4322 4323 4324
}
EXPORT_SYMBOL(netif_napi_del);

L
Linus Torvalds 已提交
4325 4326
static void net_rx_action(struct softirq_action *h)
{
4327
	struct softnet_data *sd = &__get_cpu_var(softnet_data);
4328
	unsigned long time_limit = jiffies + 2;
4329
	int budget = netdev_budget;
4330 4331
	void *have;

L
Linus Torvalds 已提交
4332 4333
	local_irq_disable();

4334
	while (!list_empty(&sd->poll_list)) {
4335 4336
		struct napi_struct *n;
		int work, weight;
L
Linus Torvalds 已提交
4337

4338
		/* If softirq window is exhuasted then punt.
4339 4340
		 * Allow this to run for 2 jiffies since which will allow
		 * an average latency of 1.5/HZ.
4341
		 */
4342
		if (unlikely(budget <= 0 || time_after_eq(jiffies, time_limit)))
L
Linus Torvalds 已提交
4343 4344 4345 4346
			goto softnet_break;

		local_irq_enable();

4347 4348 4349 4350 4351
		/* Even though interrupts have been re-enabled, this
		 * access is safe because interrupts can only add new
		 * entries to the tail of this list, and only ->poll()
		 * calls can remove this head entry from the list.
		 */
4352
		n = list_first_entry(&sd->poll_list, struct napi_struct, poll_list);
L
Linus Torvalds 已提交
4353

4354 4355 4356 4357
		have = netpoll_poll_lock(n);

		weight = n->weight;

4358 4359 4360 4361
		/* 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
L
Lucas De Marchi 已提交
4362
		 * accidentally calling ->poll() when NAPI is not scheduled.
4363 4364
		 */
		work = 0;
4365
		if (test_bit(NAPI_STATE_SCHED, &n->state)) {
4366
			work = n->poll(n, weight);
4367 4368
			trace_napi_poll(n);
		}
4369 4370 4371 4372 4373 4374 4375 4376 4377 4378 4379 4380

		WARN_ON_ONCE(work > weight);

		budget -= work;

		local_irq_disable();

		/* 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.
		 */
4381
		if (unlikely(work == weight)) {
4382 4383 4384 4385
			if (unlikely(napi_disable_pending(n))) {
				local_irq_enable();
				napi_complete(n);
				local_irq_disable();
4386 4387 4388 4389 4390 4391 4392 4393 4394
			} else {
				if (n->gro_list) {
					/* flush too old packets
					 * If HZ < 1000, flush all packets.
					 */
					local_irq_enable();
					napi_gro_flush(n, HZ >= 1000);
					local_irq_disable();
				}
4395
				list_move_tail(&n->poll_list, &sd->poll_list);
4396
			}
4397
		}
4398 4399

		netpoll_poll_unlock(have);
L
Linus Torvalds 已提交
4400 4401
	}
out:
4402
	net_rps_action_and_irq_enable(sd);
T
Tom Herbert 已提交
4403

4404 4405 4406 4407 4408
#ifdef CONFIG_NET_DMA
	/*
	 * There may not be any more sk_buffs coming right now, so push
	 * any pending DMA copies to hardware
	 */
4409
	dma_issue_pending_all();
4410
#endif
4411

L
Linus Torvalds 已提交
4412 4413 4414
	return;

softnet_break:
C
Changli Gao 已提交
4415
	sd->time_squeeze++;
L
Linus Torvalds 已提交
4416 4417 4418 4419
	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
	goto out;
}

4420
struct netdev_adjacent {
J
Jiri Pirko 已提交
4421
	struct net_device *dev;
4422 4423

	/* upper master flag, there can only be one master device per list */
J
Jiri Pirko 已提交
4424
	bool master;
4425 4426 4427 4428

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

4429 4430 4431
	/* private field for the users */
	void *private;

J
Jiri Pirko 已提交
4432 4433 4434 4435
	struct list_head list;
	struct rcu_head rcu;
};

4436 4437
static struct netdev_adjacent *__netdev_find_adj(struct net_device *dev,
						 struct net_device *adj_dev,
4438
						 struct list_head *adj_list)
J
Jiri Pirko 已提交
4439
{
4440 4441
	struct netdev_adjacent *adj;

4442
	list_for_each_entry(adj, adj_list, list) {
4443 4444
		if (adj->dev == adj_dev)
			return adj;
J
Jiri Pirko 已提交
4445 4446 4447 4448 4449 4450 4451 4452 4453 4454 4455 4456 4457 4458 4459 4460 4461 4462
	}
	return NULL;
}

/**
 * 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();

4463
	return __netdev_find_adj(dev, upper_dev, &dev->all_adj_list.upper);
J
Jiri Pirko 已提交
4464 4465 4466 4467 4468 4469 4470 4471 4472 4473
}
EXPORT_SYMBOL(netdev_has_upper_dev);

/**
 * 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
4474
static bool netdev_has_any_upper_dev(struct net_device *dev)
J
Jiri Pirko 已提交
4475 4476 4477
{
	ASSERT_RTNL();

4478
	return !list_empty(&dev->all_adj_list.upper);
J
Jiri Pirko 已提交
4479 4480 4481 4482 4483 4484 4485 4486 4487 4488 4489
}

/**
 * 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)
{
4490
	struct netdev_adjacent *upper;
J
Jiri Pirko 已提交
4491 4492 4493

	ASSERT_RTNL();

4494
	if (list_empty(&dev->adj_list.upper))
J
Jiri Pirko 已提交
4495 4496
		return NULL;

4497
	upper = list_first_entry(&dev->adj_list.upper,
4498
				 struct netdev_adjacent, list);
J
Jiri Pirko 已提交
4499 4500 4501 4502 4503 4504
	if (likely(upper->master))
		return upper->dev;
	return NULL;
}
EXPORT_SYMBOL(netdev_master_upper_dev_get);

4505 4506 4507 4508 4509 4510 4511 4512 4513 4514
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);

4515 4516
/**
 * netdev_all_upper_get_next_dev_rcu - Get the next dev from upper list
4517 4518 4519 4520 4521 4522
 * @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.
 */
4523 4524
struct net_device *netdev_all_upper_get_next_dev_rcu(struct net_device *dev,
						     struct list_head **iter)
4525 4526 4527
{
	struct netdev_adjacent *upper;

4528
	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
4529 4530 4531

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

4532
	if (&upper->list == &dev->all_adj_list.upper)
4533 4534 4535 4536 4537 4538
		return NULL;

	*iter = &upper->list;

	return upper->dev;
}
4539
EXPORT_SYMBOL(netdev_all_upper_get_next_dev_rcu);
4540

4541 4542 4543 4544 4545 4546 4547 4548 4549 4550 4551 4552 4553 4554 4555 4556 4557 4558 4559 4560 4561 4562 4563 4564 4565 4566 4567 4568 4569 4570 4571 4572 4573 4574 4575 4576 4577 4578 4579 4580 4581 4582 4583 4584 4585 4586 4587 4588 4589 4590 4591 4592 4593 4594 4595 4596 4597
/**
 * 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
 * list will remain unchainged.
 */
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;

	if (iter)
		*iter = lower->list.next;

	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;

	if (iter)
		*iter = &lower->list;

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

4598 4599 4600 4601 4602 4603 4604 4605 4606 4607 4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 4618
/**
 * 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
4619 4620 4621 4622 4623 4624 4625 4626 4627
/**
 * 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)
{
4628
	struct netdev_adjacent *upper;
J
Jiri Pirko 已提交
4629

4630
	upper = list_first_or_null_rcu(&dev->adj_list.upper,
4631
				       struct netdev_adjacent, list);
J
Jiri Pirko 已提交
4632 4633 4634 4635 4636 4637
	if (upper && likely(upper->master))
		return upper->dev;
	return NULL;
}
EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);

4638 4639 4640 4641 4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652 4653 4654 4655 4656 4657 4658 4659 4660 4661
int netdev_adjacent_sysfs_add(struct net_device *dev,
			      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);
}
void netdev_adjacent_sysfs_del(struct net_device *dev,
			       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);
}

#define netdev_adjacent_is_neigh_list(dev, dev_list) \
		(dev_list == &dev->adj_list.upper || \
		 dev_list == &dev->adj_list.lower)

4662 4663
static int __netdev_adjacent_dev_insert(struct net_device *dev,
					struct net_device *adj_dev,
4664
					struct list_head *dev_list,
4665
					void *private, bool master)
4666 4667
{
	struct netdev_adjacent *adj;
4668
	int ret;
4669

4670
	adj = __netdev_find_adj(dev, adj_dev, dev_list);
4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683

	if (adj) {
		adj->ref_nr++;
		return 0;
	}

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

	adj->dev = adj_dev;
	adj->master = master;
	adj->ref_nr = 1;
4684
	adj->private = private;
4685
	dev_hold(adj_dev);
4686 4687 4688

	pr_debug("dev_hold for %s, because of link added from %s to %s\n",
		 adj_dev->name, dev->name, adj_dev->name);
4689

4690 4691
	if (netdev_adjacent_is_neigh_list(dev, dev_list)) {
		ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
4692 4693 4694 4695
		if (ret)
			goto free_adj;
	}

4696
	/* Ensure that master link is always the first item in list. */
4697 4698 4699 4700
	if (master) {
		ret = sysfs_create_link(&(dev->dev.kobj),
					&(adj_dev->dev.kobj), "master");
		if (ret)
4701
			goto remove_symlinks;
4702

4703
		list_add_rcu(&adj->list, dev_list);
4704
	} else {
4705
		list_add_tail_rcu(&adj->list, dev_list);
4706
	}
4707 4708

	return 0;
4709

4710
remove_symlinks:
4711 4712
	if (netdev_adjacent_is_neigh_list(dev, dev_list))
		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
4713 4714
free_adj:
	kfree(adj);
4715
	dev_put(adj_dev);
4716 4717

	return ret;
4718 4719
}

S
stephen hemminger 已提交
4720 4721 4722
static void __netdev_adjacent_dev_remove(struct net_device *dev,
					 struct net_device *adj_dev,
					 struct list_head *dev_list)
4723 4724 4725
{
	struct netdev_adjacent *adj;

4726
	adj = __netdev_find_adj(dev, adj_dev, dev_list);
4727

4728 4729 4730
	if (!adj) {
		pr_err("tried to remove device %s from %s\n",
		       dev->name, adj_dev->name);
4731
		BUG();
4732
	}
4733 4734

	if (adj->ref_nr > 1) {
4735 4736
		pr_debug("%s to %s ref_nr-- = %d\n", dev->name, adj_dev->name,
			 adj->ref_nr-1);
4737 4738 4739 4740
		adj->ref_nr--;
		return;
	}

4741 4742 4743
	if (adj->master)
		sysfs_remove_link(&(dev->dev.kobj), "master");

4744 4745
	if (netdev_adjacent_is_neigh_list(dev, dev_list))
		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
4746

4747
	list_del_rcu(&adj->list);
4748 4749
	pr_debug("dev_put for %s, because link removed from %s to %s\n",
		 adj_dev->name, dev->name, adj_dev->name);
4750 4751 4752 4753
	dev_put(adj_dev);
	kfree_rcu(adj, rcu);
}

S
stephen hemminger 已提交
4754 4755 4756 4757 4758
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)
4759 4760 4761
{
	int ret;

4762 4763
	ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list, private,
					   master);
4764 4765 4766
	if (ret)
		return ret;

4767 4768
	ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list, private,
					   false);
4769
	if (ret) {
4770
		__netdev_adjacent_dev_remove(dev, upper_dev, up_list);
4771 4772 4773 4774 4775 4776
		return ret;
	}

	return 0;
}

S
stephen hemminger 已提交
4777 4778
static int __netdev_adjacent_dev_link(struct net_device *dev,
				      struct net_device *upper_dev)
4779
{
4780 4781 4782
	return __netdev_adjacent_dev_link_lists(dev, upper_dev,
						&dev->all_adj_list.upper,
						&upper_dev->all_adj_list.lower,
4783
						NULL, false);
4784 4785
}

S
stephen hemminger 已提交
4786 4787 4788 4789
static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
					       struct net_device *upper_dev,
					       struct list_head *up_list,
					       struct list_head *down_list)
4790
{
4791 4792
	__netdev_adjacent_dev_remove(dev, upper_dev, up_list);
	__netdev_adjacent_dev_remove(upper_dev, dev, down_list);
4793 4794
}

S
stephen hemminger 已提交
4795 4796
static void __netdev_adjacent_dev_unlink(struct net_device *dev,
					 struct net_device *upper_dev)
4797
{
4798 4799 4800 4801 4802
	__netdev_adjacent_dev_unlink_lists(dev, upper_dev,
					   &dev->all_adj_list.upper,
					   &upper_dev->all_adj_list.lower);
}

S
stephen hemminger 已提交
4803 4804 4805
static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
						struct net_device *upper_dev,
						void *private, bool master)
4806 4807 4808 4809 4810 4811 4812 4813 4814
{
	int ret = __netdev_adjacent_dev_link(dev, upper_dev);

	if (ret)
		return ret;

	ret = __netdev_adjacent_dev_link_lists(dev, upper_dev,
					       &dev->adj_list.upper,
					       &upper_dev->adj_list.lower,
4815
					       private, master);
4816 4817 4818 4819 4820 4821
	if (ret) {
		__netdev_adjacent_dev_unlink(dev, upper_dev);
		return ret;
	}

	return 0;
4822 4823
}

S
stephen hemminger 已提交
4824 4825
static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
						   struct net_device *upper_dev)
4826 4827 4828 4829 4830 4831
{
	__netdev_adjacent_dev_unlink(dev, upper_dev);
	__netdev_adjacent_dev_unlink_lists(dev, upper_dev,
					   &dev->adj_list.upper,
					   &upper_dev->adj_list.lower);
}
4832

J
Jiri Pirko 已提交
4833
static int __netdev_upper_dev_link(struct net_device *dev,
4834 4835
				   struct net_device *upper_dev, bool master,
				   void *private)
J
Jiri Pirko 已提交
4836
{
4837 4838
	struct netdev_adjacent *i, *j, *to_i, *to_j;
	int ret = 0;
J
Jiri Pirko 已提交
4839 4840 4841 4842 4843 4844 4845

	ASSERT_RTNL();

	if (dev == upper_dev)
		return -EBUSY;

	/* To prevent loops, check if dev is not upper device to upper_dev. */
4846
	if (__netdev_find_adj(upper_dev, dev, &upper_dev->all_adj_list.upper))
J
Jiri Pirko 已提交
4847 4848
		return -EBUSY;

4849
	if (__netdev_find_adj(dev, upper_dev, &dev->all_adj_list.upper))
J
Jiri Pirko 已提交
4850 4851 4852 4853 4854
		return -EEXIST;

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

4855 4856
	ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, private,
						   master);
4857 4858
	if (ret)
		return ret;
J
Jiri Pirko 已提交
4859

4860
	/* Now that we linked these devs, make all the upper_dev's
4861
	 * all_adj_list.upper visible to every dev's all_adj_list.lower an
4862 4863 4864
	 * versa, and don't forget the devices itself. All of these
	 * links are non-neighbours.
	 */
4865 4866 4867 4868
	list_for_each_entry(i, &dev->all_adj_list.lower, list) {
		list_for_each_entry(j, &upper_dev->all_adj_list.upper, list) {
			pr_debug("Interlinking %s with %s, non-neighbour\n",
				 i->dev->name, j->dev->name);
4869 4870 4871 4872 4873 4874 4875
			ret = __netdev_adjacent_dev_link(i->dev, j->dev);
			if (ret)
				goto rollback_mesh;
		}
	}

	/* add dev to every upper_dev's upper device */
4876 4877 4878
	list_for_each_entry(i, &upper_dev->all_adj_list.upper, list) {
		pr_debug("linking %s's upper device %s with %s\n",
			 upper_dev->name, i->dev->name, dev->name);
4879 4880 4881 4882 4883 4884
		ret = __netdev_adjacent_dev_link(dev, i->dev);
		if (ret)
			goto rollback_upper_mesh;
	}

	/* add upper_dev to every dev's lower device */
4885 4886 4887
	list_for_each_entry(i, &dev->all_adj_list.lower, list) {
		pr_debug("linking %s's lower device %s with %s\n", dev->name,
			 i->dev->name, upper_dev->name);
4888 4889 4890 4891
		ret = __netdev_adjacent_dev_link(i->dev, upper_dev);
		if (ret)
			goto rollback_lower_mesh;
	}
J
Jiri Pirko 已提交
4892

4893
	call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev);
J
Jiri Pirko 已提交
4894
	return 0;
4895 4896 4897

rollback_lower_mesh:
	to_i = i;
4898
	list_for_each_entry(i, &dev->all_adj_list.lower, list) {
4899 4900 4901 4902 4903 4904 4905 4906 4907
		if (i == to_i)
			break;
		__netdev_adjacent_dev_unlink(i->dev, upper_dev);
	}

	i = NULL;

rollback_upper_mesh:
	to_i = i;
4908
	list_for_each_entry(i, &upper_dev->all_adj_list.upper, list) {
4909 4910 4911 4912 4913 4914 4915 4916 4917 4918
		if (i == to_i)
			break;
		__netdev_adjacent_dev_unlink(dev, i->dev);
	}

	i = j = NULL;

rollback_mesh:
	to_i = i;
	to_j = j;
4919 4920
	list_for_each_entry(i, &dev->all_adj_list.lower, list) {
		list_for_each_entry(j, &upper_dev->all_adj_list.upper, list) {
4921 4922 4923 4924 4925 4926 4927 4928
			if (i == to_i && j == to_j)
				break;
			__netdev_adjacent_dev_unlink(i->dev, j->dev);
		}
		if (i == to_i)
			break;
	}

4929
	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
4930 4931

	return ret;
J
Jiri Pirko 已提交
4932 4933 4934 4935 4936 4937 4938 4939 4940 4941 4942 4943 4944 4945 4946
}

/**
 * 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)
{
4947
	return __netdev_upper_dev_link(dev, upper_dev, false, NULL);
J
Jiri Pirko 已提交
4948 4949 4950 4951 4952 4953 4954 4955 4956 4957 4958 4959 4960 4961 4962 4963 4964
}
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
 *
 * 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,
				 struct net_device *upper_dev)
{
4965
	return __netdev_upper_dev_link(dev, upper_dev, true, NULL);
J
Jiri Pirko 已提交
4966 4967 4968
}
EXPORT_SYMBOL(netdev_master_upper_dev_link);

4969 4970 4971 4972 4973 4974 4975 4976
int netdev_master_upper_dev_link_private(struct net_device *dev,
					 struct net_device *upper_dev,
					 void *private)
{
	return __netdev_upper_dev_link(dev, upper_dev, true, private);
}
EXPORT_SYMBOL(netdev_master_upper_dev_link_private);

J
Jiri Pirko 已提交
4977 4978 4979 4980 4981 4982 4983 4984 4985 4986 4987
/**
 * 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)
{
4988
	struct netdev_adjacent *i, *j;
J
Jiri Pirko 已提交
4989 4990
	ASSERT_RTNL();

4991
	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
4992 4993 4994 4995 4996

	/* Here is the tricky part. We must remove all dev's lower
	 * devices from all upper_dev's upper devices and vice
	 * versa, to maintain the graph relationship.
	 */
4997 4998
	list_for_each_entry(i, &dev->all_adj_list.lower, list)
		list_for_each_entry(j, &upper_dev->all_adj_list.upper, list)
4999 5000 5001 5002 5003
			__netdev_adjacent_dev_unlink(i->dev, j->dev);

	/* remove also the devices itself from lower/upper device
	 * list
	 */
5004
	list_for_each_entry(i, &dev->all_adj_list.lower, list)
5005 5006
		__netdev_adjacent_dev_unlink(i->dev, upper_dev);

5007
	list_for_each_entry(i, &upper_dev->all_adj_list.upper, list)
5008 5009
		__netdev_adjacent_dev_unlink(dev, i->dev);

5010
	call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev);
J
Jiri Pirko 已提交
5011 5012 5013
}
EXPORT_SYMBOL(netdev_upper_dev_unlink);

5014 5015 5016 5017 5018 5019 5020 5021 5022 5023 5024 5025 5026 5027 5028 5029 5030 5031 5032
void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
{
	struct netdev_adjacent *iter;

	list_for_each_entry(iter, &dev->adj_list.upper, list) {
		netdev_adjacent_sysfs_del(iter->dev, oldname,
					  &iter->dev->adj_list.lower);
		netdev_adjacent_sysfs_add(iter->dev, dev,
					  &iter->dev->adj_list.lower);
	}

	list_for_each_entry(iter, &dev->adj_list.lower, list) {
		netdev_adjacent_sysfs_del(iter->dev, oldname,
					  &iter->dev->adj_list.upper);
		netdev_adjacent_sysfs_add(iter->dev, dev,
					  &iter->dev->adj_list.upper);
	}
}

5033 5034 5035 5036 5037 5038 5039 5040 5041 5042 5043 5044 5045 5046 5047
void *netdev_lower_dev_get_private(struct net_device *dev,
				   struct net_device *lower_dev)
{
	struct netdev_adjacent *lower;

	if (!lower_dev)
		return NULL;
	lower = __netdev_find_adj(dev, lower_dev, &dev->adj_list.lower);
	if (!lower)
		return NULL;

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

5048 5049
static void dev_change_rx_flags(struct net_device *dev, int flags)
{
5050 5051
	const struct net_device_ops *ops = dev->netdev_ops;

5052
	if (ops->ndo_change_rx_flags)
5053
		ops->ndo_change_rx_flags(dev, flags);
5054 5055
}

5056
static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
L
Linus Torvalds 已提交
5057
{
5058
	unsigned int old_flags = dev->flags;
5059 5060
	kuid_t uid;
	kgid_t gid;
L
Linus Torvalds 已提交
5061

5062 5063
	ASSERT_RTNL();

5064 5065 5066 5067 5068 5069 5070 5071 5072 5073 5074
	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;
5075 5076
			pr_warn("%s: promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n",
				dev->name);
5077 5078 5079
			return -EOVERFLOW;
		}
	}
5080
	if (dev->flags != old_flags) {
5081 5082 5083
		pr_info("device %s %s promiscuous mode\n",
			dev->name,
			dev->flags & IFF_PROMISC ? "entered" : "left");
5084 5085
		if (audit_enabled) {
			current_uid_gid(&uid, &gid);
5086 5087 5088 5089 5090
			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),
5091
				from_kuid(&init_user_ns, audit_get_loginuid(current)),
5092 5093
				from_kuid(&init_user_ns, uid),
				from_kgid(&init_user_ns, gid),
5094
				audit_get_sessionid(current));
5095
		}
5096

5097
		dev_change_rx_flags(dev, IFF_PROMISC);
L
Linus Torvalds 已提交
5098
	}
5099 5100
	if (notify)
		__dev_notify_flags(dev, old_flags, IFF_PROMISC);
5101
	return 0;
L
Linus Torvalds 已提交
5102 5103
}

5104 5105 5106 5107 5108 5109 5110 5111 5112
/**
 *	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.
5113
 *	Return 0 if successful or a negative errno code on error.
5114
 */
5115
int dev_set_promiscuity(struct net_device *dev, int inc)
5116
{
5117
	unsigned int old_flags = dev->flags;
5118
	int err;
5119

5120
	err = __dev_set_promiscuity(dev, inc, true);
5121
	if (err < 0)
5122
		return err;
5123 5124
	if (dev->flags != old_flags)
		dev_set_rx_mode(dev);
5125
	return err;
5126
}
E
Eric Dumazet 已提交
5127
EXPORT_SYMBOL(dev_set_promiscuity);
5128

5129
static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
L
Linus Torvalds 已提交
5130
{
5131
	unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
L
Linus Torvalds 已提交
5132

5133 5134
	ASSERT_RTNL();

L
Linus Torvalds 已提交
5135
	dev->flags |= IFF_ALLMULTI;
5136 5137 5138 5139 5140 5141 5142 5143 5144 5145
	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;
5146 5147
			pr_warn("%s: allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n",
				dev->name);
5148 5149 5150
			return -EOVERFLOW;
		}
	}
5151
	if (dev->flags ^ old_flags) {
5152
		dev_change_rx_flags(dev, IFF_ALLMULTI);
5153
		dev_set_rx_mode(dev);
5154 5155 5156
		if (notify)
			__dev_notify_flags(dev, old_flags,
					   dev->gflags ^ old_gflags);
5157
	}
5158
	return 0;
5159
}
5160 5161 5162 5163 5164 5165 5166 5167 5168 5169 5170 5171 5172 5173 5174 5175 5176 5177

/**
 *	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
5178
EXPORT_SYMBOL(dev_set_allmulti);
5179 5180 5181 5182

/*
 *	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
5183
 *	filtering it is put in promiscuous mode while unicast addresses
5184 5185 5186 5187
 *	are present.
 */
void __dev_set_rx_mode(struct net_device *dev)
{
5188 5189
	const struct net_device_ops *ops = dev->netdev_ops;

5190 5191 5192 5193 5194
	/* dev_open will call this function so the list will stay sane. */
	if (!(dev->flags&IFF_UP))
		return;

	if (!netif_device_present(dev))
5195
		return;
5196

5197
	if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
5198 5199 5200
		/* Unicast addresses changes may only happen under the rtnl,
		 * therefore calling __dev_set_promiscuity here is safe.
		 */
5201
		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
5202
			__dev_set_promiscuity(dev, 1, false);
5203
			dev->uc_promisc = true;
5204
		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
5205
			__dev_set_promiscuity(dev, -1, false);
5206
			dev->uc_promisc = false;
5207 5208
		}
	}
5209 5210 5211

	if (ops->ndo_set_rx_mode)
		ops->ndo_set_rx_mode(dev);
5212 5213 5214 5215
}

void dev_set_rx_mode(struct net_device *dev)
{
5216
	netif_addr_lock_bh(dev);
5217
	__dev_set_rx_mode(dev);
5218
	netif_addr_unlock_bh(dev);
L
Linus Torvalds 已提交
5219 5220
}

5221 5222 5223 5224 5225 5226
/**
 *	dev_get_flags - get flags reported to userspace
 *	@dev: device
 *
 *	Get the combination of flag bits exported through APIs to userspace.
 */
5227
unsigned int dev_get_flags(const struct net_device *dev)
L
Linus Torvalds 已提交
5228
{
5229
	unsigned int flags;
L
Linus Torvalds 已提交
5230 5231 5232

	flags = (dev->flags & ~(IFF_PROMISC |
				IFF_ALLMULTI |
S
Stefan Rompf 已提交
5233 5234 5235
				IFF_RUNNING |
				IFF_LOWER_UP |
				IFF_DORMANT)) |
L
Linus Torvalds 已提交
5236 5237 5238
		(dev->gflags & (IFF_PROMISC |
				IFF_ALLMULTI));

S
Stefan Rompf 已提交
5239 5240 5241 5242 5243 5244 5245 5246
	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
5247 5248 5249

	return flags;
}
E
Eric Dumazet 已提交
5250
EXPORT_SYMBOL(dev_get_flags);
L
Linus Torvalds 已提交
5251

5252
int __dev_change_flags(struct net_device *dev, unsigned int flags)
L
Linus Torvalds 已提交
5253
{
5254
	unsigned int old_flags = dev->flags;
5255
	int ret;
L
Linus Torvalds 已提交
5256

5257 5258
	ASSERT_RTNL();

L
Linus Torvalds 已提交
5259 5260 5261 5262 5263 5264 5265 5266 5267 5268 5269 5270 5271 5272
	/*
	 *	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.
	 */

5273 5274
	if ((old_flags ^ flags) & IFF_MULTICAST)
		dev_change_rx_flags(dev, IFF_MULTICAST);
5275

5276
	dev_set_rx_mode(dev);
L
Linus Torvalds 已提交
5277 5278 5279 5280 5281 5282 5283 5284 5285

	/*
	 *	Have we downed the interface. We handle IFF_UP ourselves
	 *	according to user attempts to set it, rather than blindly
	 *	setting it.
	 */

	ret = 0;
	if ((old_flags ^ flags) & IFF_UP) {	/* Bit is different  ? */
5286
		ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev);
L
Linus Torvalds 已提交
5287 5288

		if (!ret)
5289
			dev_set_rx_mode(dev);
L
Linus Torvalds 已提交
5290 5291 5292
	}

	if ((flags ^ dev->gflags) & IFF_PROMISC) {
E
Eric Dumazet 已提交
5293
		int inc = (flags & IFF_PROMISC) ? 1 : -1;
5294
		unsigned int old_flags = dev->flags;
E
Eric Dumazet 已提交
5295

L
Linus Torvalds 已提交
5296
		dev->gflags ^= IFF_PROMISC;
5297 5298 5299 5300

		if (__dev_set_promiscuity(dev, inc, false) >= 0)
			if (dev->flags != old_flags)
				dev_set_rx_mode(dev);
L
Linus Torvalds 已提交
5301 5302 5303 5304 5305 5306 5307
	}

	/* 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
5308 5309
		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;

L
Linus Torvalds 已提交
5310
		dev->gflags ^= IFF_ALLMULTI;
5311
		__dev_set_allmulti(dev, inc, false);
L
Linus Torvalds 已提交
5312 5313
	}

5314 5315 5316
	return ret;
}

5317 5318
void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
			unsigned int gchanges)
5319 5320 5321
{
	unsigned int changes = dev->flags ^ old_flags;

5322
	if (gchanges)
5323
		rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC);
5324

5325 5326 5327 5328 5329 5330 5331 5332
	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 &&
5333 5334 5335 5336 5337 5338 5339
	    (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);
	}
5340 5341 5342 5343 5344 5345 5346 5347 5348 5349
}

/**
 *	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.
 */
5350
int dev_change_flags(struct net_device *dev, unsigned int flags)
5351
{
5352
	int ret;
5353
	unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
5354 5355 5356 5357 5358

	ret = __dev_change_flags(dev, flags);
	if (ret < 0)
		return ret;

5359
	changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
5360
	__dev_notify_flags(dev, old_flags, changes);
L
Linus Torvalds 已提交
5361 5362
	return ret;
}
E
Eric Dumazet 已提交
5363
EXPORT_SYMBOL(dev_change_flags);
L
Linus Torvalds 已提交
5364

5365 5366 5367 5368 5369 5370 5371 5372 5373 5374 5375
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;
}

5376 5377 5378 5379 5380 5381 5382
/**
 *	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
5383 5384
int dev_set_mtu(struct net_device *dev, int new_mtu)
{
5385
	int err, orig_mtu;
L
Linus Torvalds 已提交
5386 5387 5388 5389 5390 5391 5392 5393 5394 5395 5396

	if (new_mtu == dev->mtu)
		return 0;

	/*	MTU must be positive.	 */
	if (new_mtu < 0)
		return -EINVAL;

	if (!netif_device_present(dev))
		return -ENODEV;

5397 5398 5399 5400 5401
	err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
	err = notifier_to_errno(err);
	if (err)
		return err;

5402 5403
	orig_mtu = dev->mtu;
	err = __dev_set_mtu(dev, new_mtu);
5404

5405 5406 5407 5408 5409 5410 5411 5412 5413 5414 5415
	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
5416 5417
	return err;
}
E
Eric Dumazet 已提交
5418
EXPORT_SYMBOL(dev_set_mtu);
L
Linus Torvalds 已提交
5419

5420 5421 5422 5423 5424 5425 5426 5427 5428 5429 5430
/**
 *	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);

5431 5432 5433 5434 5435 5436 5437
/**
 *	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
5438 5439
int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
{
5440
	const struct net_device_ops *ops = dev->netdev_ops;
L
Linus Torvalds 已提交
5441 5442
	int err;

5443
	if (!ops->ndo_set_mac_address)
L
Linus Torvalds 已提交
5444 5445 5446 5447 5448
		return -EOPNOTSUPP;
	if (sa->sa_family != dev->type)
		return -EINVAL;
	if (!netif_device_present(dev))
		return -ENODEV;
5449
	err = ops->ndo_set_mac_address(dev, sa);
5450 5451
	if (err)
		return err;
J
Jiri Pirko 已提交
5452
	dev->addr_assign_type = NET_ADDR_SET;
5453
	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
5454
	add_device_randomness(dev->dev_addr, dev->addr_len);
5455
	return 0;
L
Linus Torvalds 已提交
5456
}
E
Eric Dumazet 已提交
5457
EXPORT_SYMBOL(dev_set_mac_address);
L
Linus Torvalds 已提交
5458

J
Jiri Pirko 已提交
5459 5460 5461
/**
 *	dev_change_carrier - Change device carrier
 *	@dev: device
5462
 *	@new_carrier: new value
J
Jiri Pirko 已提交
5463 5464 5465 5466 5467 5468 5469 5470 5471 5472 5473 5474 5475 5476 5477
 *
 *	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);

5478 5479 5480 5481 5482 5483 5484 5485 5486 5487 5488 5489 5490 5491 5492 5493 5494 5495
/**
 *	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,
			 struct netdev_phys_port_id *ppid)
{
	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);

L
Linus Torvalds 已提交
5496 5497
/**
 *	dev_new_index	-	allocate an ifindex
5498
 *	@net: the applicable net namespace
L
Linus Torvalds 已提交
5499 5500 5501 5502 5503
 *
 *	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.
 */
5504
static int dev_new_index(struct net *net)
L
Linus Torvalds 已提交
5505
{
5506
	int ifindex = net->ifindex;
L
Linus Torvalds 已提交
5507 5508 5509
	for (;;) {
		if (++ifindex <= 0)
			ifindex = 1;
5510
		if (!__dev_get_by_index(net, ifindex))
5511
			return net->ifindex = ifindex;
L
Linus Torvalds 已提交
5512 5513 5514 5515
	}
}

/* Delayed registration/unregisteration */
5516
static LIST_HEAD(net_todo_list);
5517
static DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
L
Linus Torvalds 已提交
5518

5519
static void net_set_todo(struct net_device *dev)
L
Linus Torvalds 已提交
5520 5521
{
	list_add_tail(&dev->todo_list, &net_todo_list);
5522
	dev_net(dev)->dev_unreg_count++;
L
Linus Torvalds 已提交
5523 5524
}

5525
static void rollback_registered_many(struct list_head *head)
5526
{
5527
	struct net_device *dev, *tmp;
5528
	LIST_HEAD(close_head);
5529

5530 5531 5532
	BUG_ON(dev_boot_phase);
	ASSERT_RTNL();

5533
	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
5534
		/* Some devices call without registering
5535 5536
		 * for initialization unwind. Remove those
		 * devices and proceed with the remaining.
5537 5538
		 */
		if (dev->reg_state == NETREG_UNINITIALIZED) {
5539 5540
			pr_debug("unregister_netdevice: device %s/%p never was registered\n",
				 dev->name, dev);
5541

5542
			WARN_ON(1);
5543 5544
			list_del(&dev->unreg_list);
			continue;
5545
		}
5546
		dev->dismantle = true;
5547
		BUG_ON(dev->reg_state != NETREG_REGISTERED);
5548
	}
5549

5550
	/* If device is running, close it first. */
5551 5552 5553
	list_for_each_entry(dev, head, unreg_list)
		list_add_tail(&dev->close_list, &close_head);
	dev_close_many(&close_head);
5554

5555
	list_for_each_entry(dev, head, unreg_list) {
5556 5557
		/* And unlink it from device chain. */
		unlist_netdevice(dev);
5558

5559 5560
		dev->reg_state = NETREG_UNREGISTERING;
	}
5561 5562 5563

	synchronize_net();

5564 5565 5566
	list_for_each_entry(dev, head, unreg_list) {
		/* Shutdown queueing discipline. */
		dev_shutdown(dev);
5567 5568


5569 5570 5571 5572
		/* Notify protocols, that we are about to destroy
		   this device. They should clean all the things.
		*/
		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5573

5574 5575
		if (!dev->rtnl_link_ops ||
		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
5576
			rtmsg_ifinfo(RTM_DELLINK, dev, ~0U, GFP_KERNEL);
5577

5578 5579 5580
		/*
		 *	Flush the unicast and multicast chains
		 */
5581
		dev_uc_flush(dev);
5582
		dev_mc_flush(dev);
5583

5584 5585
		if (dev->netdev_ops->ndo_uninit)
			dev->netdev_ops->ndo_uninit(dev);
5586

J
Jiri Pirko 已提交
5587 5588
		/* Notifier chain MUST detach us all upper devices. */
		WARN_ON(netdev_has_any_upper_dev(dev));
5589

5590 5591
		/* Remove entries from kobject tree */
		netdev_unregister_kobject(dev);
5592 5593 5594 5595
#ifdef CONFIG_XPS
		/* Remove XPS queueing entries */
		netif_reset_xps_queues_gt(dev, 0);
#endif
5596
	}
5597

5598
	synchronize_net();
5599

5600
	list_for_each_entry(dev, head, unreg_list)
5601 5602 5603 5604 5605 5606 5607 5608 5609
		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
5610
	list_del(&single);
5611 5612
}

5613 5614
static netdev_features_t netdev_fix_features(struct net_device *dev,
	netdev_features_t features)
5615
{
5616 5617 5618
	/* Fix illegal checksum combinations */
	if ((features & NETIF_F_HW_CSUM) &&
	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5619
		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
5620 5621 5622
		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
	}

5623
	/* TSO requires that SG is present as well. */
5624
	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
5625
		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
5626
		features &= ~NETIF_F_ALL_TSO;
5627 5628
	}

5629 5630 5631 5632 5633 5634 5635 5636 5637 5638 5639 5640 5641
	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;
	}

5642 5643 5644 5645
	/* TSO ECN requires that TSO is present as well. */
	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
		features &= ~NETIF_F_TSO_ECN;

5646 5647
	/* Software GSO depends on SG. */
	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
5648
		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
5649 5650 5651
		features &= ~NETIF_F_GSO;
	}

5652
	/* UFO needs SG and checksumming */
5653
	if (features & NETIF_F_UFO) {
5654 5655 5656 5657
		/* maybe split UFO into V4 and V6? */
		if (!((features & NETIF_F_GEN_CSUM) ||
		    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))
			    == (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5658
			netdev_dbg(dev,
5659
				"Dropping NETIF_F_UFO since no checksum offload features.\n");
5660 5661 5662 5663
			features &= ~NETIF_F_UFO;
		}

		if (!(features & NETIF_F_SG)) {
5664
			netdev_dbg(dev,
5665
				"Dropping NETIF_F_UFO since no NETIF_F_SG feature.\n");
5666 5667 5668 5669 5670 5671 5672
			features &= ~NETIF_F_UFO;
		}
	}

	return features;
}

5673
int __netdev_update_features(struct net_device *dev)
5674
{
5675
	netdev_features_t features;
5676 5677
	int err = 0;

5678 5679
	ASSERT_RTNL();

5680 5681 5682 5683 5684 5685 5686 5687 5688
	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);

	if (dev->features == features)
5689
		return 0;
5690

5691 5692
	netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
		&dev->features, &features);
5693 5694 5695 5696

	if (dev->netdev_ops->ndo_set_features)
		err = dev->netdev_ops->ndo_set_features(dev, features);

5697
	if (unlikely(err < 0)) {
5698
		netdev_err(dev,
5699 5700
			"set_features() failed (%d); wanted %pNF, left %pNF\n",
			err, &features, &dev->features);
5701 5702 5703 5704 5705 5706 5707 5708 5709
		return -1;
	}

	if (!err)
		dev->features = features;

	return 1;
}

5710 5711 5712 5713 5714 5715 5716 5717
/**
 *	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.
 */
5718 5719 5720 5721
void netdev_update_features(struct net_device *dev)
{
	if (__netdev_update_features(dev))
		netdev_features_change(dev);
5722 5723 5724
}
EXPORT_SYMBOL(netdev_update_features);

5725 5726 5727 5728 5729 5730 5731 5732 5733 5734 5735 5736 5737 5738 5739 5740 5741
/**
 *	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);

5742 5743 5744 5745 5746 5747 5748 5749 5750 5751 5752 5753 5754 5755 5756 5757 5758 5759 5760 5761 5762 5763 5764 5765 5766 5767 5768
/**
 *	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);

5769
#ifdef CONFIG_SYSFS
5770 5771 5772
static int netif_alloc_rx_queues(struct net_device *dev)
{
	unsigned int i, count = dev->num_rx_queues;
T
Tom Herbert 已提交
5773
	struct netdev_rx_queue *rx;
5774

T
Tom Herbert 已提交
5775
	BUG_ON(count < 1);
5776

T
Tom Herbert 已提交
5777
	rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL);
5778
	if (!rx)
T
Tom Herbert 已提交
5779
		return -ENOMEM;
5780

T
Tom Herbert 已提交
5781 5782 5783
	dev->_rx = rx;

	for (i = 0; i < count; i++)
T
Tom Herbert 已提交
5784
		rx[i].dev = dev;
5785 5786
	return 0;
}
T
Tom Herbert 已提交
5787
#endif
5788

C
Changli Gao 已提交
5789 5790 5791 5792 5793 5794 5795
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;
5796
	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
C
Changli Gao 已提交
5797
	queue->dev = dev;
T
Tom Herbert 已提交
5798 5799 5800
#ifdef CONFIG_BQL
	dql_init(&queue->dql, HZ);
#endif
C
Changli Gao 已提交
5801 5802
}

5803 5804 5805 5806 5807 5808 5809 5810
static void netif_free_tx_queues(struct net_device *dev)
{
	if (is_vmalloc_addr(dev->_tx))
		vfree(dev->_tx);
	else
		kfree(dev->_tx);
}

5811 5812 5813 5814
static int netif_alloc_netdev_queues(struct net_device *dev)
{
	unsigned int count = dev->num_tx_queues;
	struct netdev_queue *tx;
5815
	size_t sz = count * sizeof(*tx);
5816

5817
	BUG_ON(count < 1 || count > 0xffff);
5818

5819 5820 5821 5822 5823 5824
	tx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
	if (!tx) {
		tx = vzalloc(sz);
		if (!tx)
			return -ENOMEM;
	}
5825
	dev->_tx = tx;
T
Tom Herbert 已提交
5826

5827 5828
	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
	spin_lock_init(&dev->tx_global_lock);
C
Changli Gao 已提交
5829 5830

	return 0;
5831 5832
}

L
Linus Torvalds 已提交
5833 5834 5835 5836 5837 5838 5839 5840 5841 5842 5843 5844 5845 5846 5847 5848 5849 5850 5851 5852
/**
 *	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;
5853
	struct net *net = dev_net(dev);
L
Linus Torvalds 已提交
5854 5855 5856 5857

	BUG_ON(dev_boot_phase);
	ASSERT_RTNL();

5858 5859
	might_sleep();

L
Linus Torvalds 已提交
5860 5861
	/* When net_device's are persistent, this will be fatal. */
	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
5862
	BUG_ON(!net);
L
Linus Torvalds 已提交
5863

5864
	spin_lock_init(&dev->addr_list_lock);
5865
	netdev_set_addr_lockdep_class(dev);
L
Linus Torvalds 已提交
5866 5867 5868

	dev->iflink = -1;

5869
	ret = dev_get_valid_name(net, dev, dev->name);
5870 5871 5872
	if (ret < 0)
		goto out;

L
Linus Torvalds 已提交
5873
	/* Init, if this function is available */
5874 5875
	if (dev->netdev_ops->ndo_init) {
		ret = dev->netdev_ops->ndo_init(dev);
L
Linus Torvalds 已提交
5876 5877 5878
		if (ret) {
			if (ret > 0)
				ret = -EIO;
5879
			goto out;
L
Linus Torvalds 已提交
5880 5881
		}
	}
5882

5883 5884
	if (((dev->hw_features | dev->features) &
	     NETIF_F_HW_VLAN_CTAG_FILTER) &&
5885 5886 5887 5888 5889 5890 5891
	    (!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;
	}

5892 5893 5894 5895 5896 5897
	ret = -EBUSY;
	if (!dev->ifindex)
		dev->ifindex = dev_new_index(net);
	else if (__dev_get_by_index(net, dev->ifindex))
		goto err_uninit;

L
Linus Torvalds 已提交
5898 5899 5900
	if (dev->iflink == -1)
		dev->iflink = dev->ifindex;

5901 5902 5903 5904
	/* Transfer changeable features to wanted_features and enable
	 * software offloads (GSO and GRO).
	 */
	dev->hw_features |= NETIF_F_SOFT_FEATURES;
5905 5906
	dev->features |= NETIF_F_SOFT_FEATURES;
	dev->wanted_features = dev->features & dev->hw_features;
L
Linus Torvalds 已提交
5907

5908 5909
	if (!(dev->flags & IFF_LOOPBACK)) {
		dev->hw_features |= NETIF_F_NOCACHE_COPY;
5910 5911
	}

5912
	/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
5913
	 */
5914
	dev->vlan_features |= NETIF_F_HIGHDMA;
5915

5916 5917 5918 5919
	/* Make NETIF_F_SG inheritable to tunnel devices.
	 */
	dev->hw_enc_features |= NETIF_F_SG;

S
Simon Horman 已提交
5920 5921 5922 5923
	/* Make NETIF_F_SG inheritable to MPLS.
	 */
	dev->mpls_features |= NETIF_F_SG;

5924 5925 5926 5927 5928
	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
	ret = notifier_to_errno(ret);
	if (ret)
		goto err_uninit;

5929
	ret = netdev_register_kobject(dev);
5930
	if (ret)
5931
		goto err_uninit;
5932 5933
	dev->reg_state = NETREG_REGISTERED;

5934
	__netdev_update_features(dev);
5935

L
Linus Torvalds 已提交
5936 5937 5938 5939 5940 5941 5942
	/*
	 *	Default initial state at registry is that the
	 *	device is present.
	 */

	set_bit(__LINK_STATE_PRESENT, &dev->state);

5943 5944
	linkwatch_init_dev(dev);

L
Linus Torvalds 已提交
5945 5946
	dev_init_scheduler(dev);
	dev_hold(dev);
5947
	list_netdevice(dev);
5948
	add_device_randomness(dev->dev_addr, dev->addr_len);
L
Linus Torvalds 已提交
5949

5950 5951 5952 5953 5954 5955 5956
	/* 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
5957
	/* Notify protocols, that a new device appeared. */
5958
	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
5959
	ret = notifier_to_errno(ret);
5960 5961 5962 5963
	if (ret) {
		rollback_registered(dev);
		dev->reg_state = NETREG_UNREGISTERED;
	}
5964 5965 5966 5967
	/*
	 *	Prevent userspace races by waiting until the network
	 *	device is fully setup before sending notifications.
	 */
5968 5969
	if (!dev->rtnl_link_ops ||
	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
5970
		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
L
Linus Torvalds 已提交
5971 5972 5973

out:
	return ret;
5974 5975

err_uninit:
5976 5977
	if (dev->netdev_ops->ndo_uninit)
		dev->netdev_ops->ndo_uninit(dev);
5978
	goto out;
L
Linus Torvalds 已提交
5979
}
E
Eric Dumazet 已提交
5980
EXPORT_SYMBOL(register_netdevice);
L
Linus Torvalds 已提交
5981

5982 5983 5984 5985 5986 5987 5988 5989 5990 5991 5992 5993 5994 5995 5996 5997 5998 5999 6000 6001 6002 6003 6004 6005 6006 6007 6008 6009 6010 6011 6012
/**
 *	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
6013 6014 6015 6016 6017
	/* Note : We dont allocate pcpu_refcnt for dummy devices,
	 * because users of this 'device' dont need to change
	 * its refcount.
	 */

6018 6019 6020 6021 6022
	return 0;
}
EXPORT_SYMBOL_GPL(init_dummy_netdev);


L
Linus Torvalds 已提交
6023 6024 6025 6026 6027 6028 6029 6030 6031
/**
 *	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.
 *
6032
 *	This is a wrapper around register_netdevice that takes the rtnl semaphore
L
Linus Torvalds 已提交
6033 6034 6035 6036 6037 6038 6039 6040 6041 6042 6043 6044 6045 6046
 *	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
6047 6048 6049 6050 6051 6052 6053 6054 6055 6056
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);

6057
/**
L
Linus Torvalds 已提交
6058
 * netdev_wait_allrefs - wait until all references are gone.
6059
 * @dev: target net_device
L
Linus Torvalds 已提交
6060 6061 6062 6063 6064 6065 6066
 *
 * 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
6067
 * call dev_put.
L
Linus Torvalds 已提交
6068 6069 6070 6071
 */
static void netdev_wait_allrefs(struct net_device *dev)
{
	unsigned long rebroadcast_time, warning_time;
E
Eric Dumazet 已提交
6072
	int refcnt;
L
Linus Torvalds 已提交
6073

6074 6075
	linkwatch_forget_dev(dev);

L
Linus Torvalds 已提交
6076
	rebroadcast_time = warning_time = jiffies;
E
Eric Dumazet 已提交
6077 6078 6079
	refcnt = netdev_refcnt_read(dev);

	while (refcnt != 0) {
L
Linus Torvalds 已提交
6080
		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
6081
			rtnl_lock();
L
Linus Torvalds 已提交
6082 6083

			/* Rebroadcast unregister notification */
6084
			call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
L
Linus Torvalds 已提交
6085

6086
			__rtnl_unlock();
6087
			rcu_barrier();
6088 6089
			rtnl_lock();

6090
			call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
L
Linus Torvalds 已提交
6091 6092 6093 6094 6095 6096 6097 6098 6099 6100 6101
			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();
			}

6102
			__rtnl_unlock();
L
Linus Torvalds 已提交
6103 6104 6105 6106 6107 6108

			rebroadcast_time = jiffies;
		}

		msleep(250);

E
Eric Dumazet 已提交
6109 6110
		refcnt = netdev_refcnt_read(dev);

L
Linus Torvalds 已提交
6111
		if (time_after(jiffies, warning_time + 10 * HZ)) {
6112 6113
			pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
				 dev->name, refcnt);
L
Linus Torvalds 已提交
6114 6115 6116 6117 6118 6119 6120 6121 6122 6123 6124 6125 6126 6127 6128 6129 6130 6131 6132
			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
6133
 * We are invoked by rtnl_unlock().
L
Linus Torvalds 已提交
6134
 * This allows us to deal with problems:
6135
 * 1) We can delete sysfs objects which invoke hotplug
L
Linus Torvalds 已提交
6136 6137 6138
 *    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
6139 6140 6141
 *
 * 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
6142 6143 6144
 */
void netdev_run_todo(void)
{
6145
	struct list_head list;
L
Linus Torvalds 已提交
6146 6147

	/* Snapshot list, allow later requests */
6148
	list_replace_init(&net_todo_list, &list);
H
Herbert Xu 已提交
6149 6150

	__rtnl_unlock();
6151

6152 6153

	/* Wait for rcu callbacks to finish before next phase */
6154 6155 6156
	if (!list_empty(&list))
		rcu_barrier();

L
Linus Torvalds 已提交
6157 6158
	while (!list_empty(&list)) {
		struct net_device *dev
6159
			= list_first_entry(&list, struct net_device, todo_list);
L
Linus Torvalds 已提交
6160 6161
		list_del(&dev->todo_list);

6162
		rtnl_lock();
6163
		call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
6164
		__rtnl_unlock();
6165

6166
		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
6167
			pr_err("network todo '%s' but state %d\n",
6168 6169 6170 6171
			       dev->name, dev->reg_state);
			dump_stack();
			continue;
		}
L
Linus Torvalds 已提交
6172

6173
		dev->reg_state = NETREG_UNREGISTERED;
L
Linus Torvalds 已提交
6174

6175
		on_each_cpu(flush_backlog, dev, 1);
6176

6177
		netdev_wait_allrefs(dev);
L
Linus Torvalds 已提交
6178

6179
		/* paranoia */
E
Eric Dumazet 已提交
6180
		BUG_ON(netdev_refcnt_read(dev));
6181 6182
		WARN_ON(rcu_access_pointer(dev->ip_ptr));
		WARN_ON(rcu_access_pointer(dev->ip6_ptr));
6183
		WARN_ON(dev->dn_ptr);
L
Linus Torvalds 已提交
6184

6185 6186
		if (dev->destructor)
			dev->destructor(dev);
6187

6188 6189 6190 6191 6192 6193
		/* Report a network device has been unregistered */
		rtnl_lock();
		dev_net(dev)->dev_unreg_count--;
		__rtnl_unlock();
		wake_up(&netdev_unregistering_wq);

6194 6195
		/* Free network device */
		kobject_put(&dev->dev.kobj);
L
Linus Torvalds 已提交
6196 6197 6198
	}
}

6199 6200 6201
/* Convert net_device_stats to rtnl_link_stats64.  They have the same
 * fields in the same order, with only the type differing.
 */
6202 6203
void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
			     const struct net_device_stats *netdev_stats)
6204 6205
{
#if BITS_PER_LONG == 64
6206 6207
	BUILD_BUG_ON(sizeof(*stats64) != sizeof(*netdev_stats));
	memcpy(stats64, netdev_stats, sizeof(*stats64));
6208 6209 6210 6211 6212 6213 6214 6215 6216 6217 6218
#else
	size_t i, n = sizeof(*stats64) / sizeof(u64);
	const unsigned long *src = (const unsigned long *)netdev_stats;
	u64 *dst = (u64 *)stats64;

	BUILD_BUG_ON(sizeof(*netdev_stats) / sizeof(unsigned long) !=
		     sizeof(*stats64) / sizeof(u64));
	for (i = 0; i < n; i++)
		dst[i] = src[i];
#endif
}
6219
EXPORT_SYMBOL(netdev_stats_to_stats64);
6220

6221 6222 6223
/**
 *	dev_get_stats	- get network device statistics
 *	@dev: device to get statistics from
6224
 *	@storage: place to store stats
6225
 *
6226 6227 6228 6229
 *	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.
6230
 */
6231 6232
struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
					struct rtnl_link_stats64 *storage)
6233
{
6234 6235
	const struct net_device_ops *ops = dev->netdev_ops;

6236 6237
	if (ops->ndo_get_stats64) {
		memset(storage, 0, sizeof(*storage));
6238 6239
		ops->ndo_get_stats64(dev, storage);
	} else if (ops->ndo_get_stats) {
6240
		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
6241 6242
	} else {
		netdev_stats_to_stats64(storage, &dev->stats);
6243
	}
6244
	storage->rx_dropped += atomic_long_read(&dev->rx_dropped);
6245
	return storage;
R
Rusty Russell 已提交
6246
}
6247
EXPORT_SYMBOL(dev_get_stats);
R
Rusty Russell 已提交
6248

6249
struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
6250
{
6251
	struct netdev_queue *queue = dev_ingress_queue(dev);
6252

6253 6254 6255 6256 6257 6258 6259 6260 6261 6262 6263 6264
#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);
	queue->qdisc = &noop_qdisc;
	queue->qdisc_sleeping = &noop_qdisc;
	rcu_assign_pointer(dev->ingress_queue, queue);
#endif
	return queue;
6265 6266
}

6267 6268
static const struct ethtool_ops default_ethtool_ops;

6269 6270 6271 6272 6273 6274 6275 6276
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);

6277 6278 6279 6280 6281 6282 6283 6284 6285 6286
void netdev_freemem(struct net_device *dev)
{
	char *addr = (char *)dev - dev->padded;

	if (is_vmalloc_addr(addr))
		vfree(addr);
	else
		kfree(addr);
}

L
Linus Torvalds 已提交
6287
/**
T
Tom Herbert 已提交
6288
 *	alloc_netdev_mqs - allocate network device
L
Linus Torvalds 已提交
6289 6290 6291
 *	@sizeof_priv:	size of private data to allocate space for
 *	@name:		device name format string
 *	@setup:		callback to initialize device
T
Tom Herbert 已提交
6292 6293
 *	@txqs:		the number of TX subqueues to allocate
 *	@rxqs:		the number of RX subqueues to allocate
L
Linus Torvalds 已提交
6294 6295
 *
 *	Allocates a struct net_device with private data area for driver use
6296
 *	and performs basic initialization.  Also allocates subquue structs
T
Tom Herbert 已提交
6297
 *	for each queue on the device.
L
Linus Torvalds 已提交
6298
 */
T
Tom Herbert 已提交
6299 6300 6301
struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
		void (*setup)(struct net_device *),
		unsigned int txqs, unsigned int rxqs)
L
Linus Torvalds 已提交
6302 6303
{
	struct net_device *dev;
6304
	size_t alloc_size;
6305
	struct net_device *p;
L
Linus Torvalds 已提交
6306

6307 6308
	BUG_ON(strlen(name) >= sizeof(dev->name));

T
Tom Herbert 已提交
6309
	if (txqs < 1) {
6310
		pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
6311 6312 6313
		return NULL;
	}

6314
#ifdef CONFIG_SYSFS
T
Tom Herbert 已提交
6315
	if (rxqs < 1) {
6316
		pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
T
Tom Herbert 已提交
6317 6318 6319 6320
		return NULL;
	}
#endif

6321
	alloc_size = sizeof(struct net_device);
6322 6323
	if (sizeof_priv) {
		/* ensure 32-byte alignment of private area */
6324
		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
6325 6326 6327
		alloc_size += sizeof_priv;
	}
	/* ensure 32-byte alignment of whole construct */
6328
	alloc_size += NETDEV_ALIGN - 1;
L
Linus Torvalds 已提交
6329

6330 6331 6332
	p = kzalloc(alloc_size, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
	if (!p)
		p = vzalloc(alloc_size);
6333
	if (!p)
L
Linus Torvalds 已提交
6334 6335
		return NULL;

6336
	dev = PTR_ALIGN(p, NETDEV_ALIGN);
L
Linus Torvalds 已提交
6337
	dev->padded = (char *)dev - (char *)p;
6338

E
Eric Dumazet 已提交
6339 6340
	dev->pcpu_refcnt = alloc_percpu(int);
	if (!dev->pcpu_refcnt)
6341
		goto free_dev;
6342 6343

	if (dev_addr_init(dev))
E
Eric Dumazet 已提交
6344
		goto free_pcpu;
6345

6346
	dev_mc_init(dev);
6347
	dev_uc_init(dev);
J
Jiri Pirko 已提交
6348

6349
	dev_net_set(dev, &init_net);
L
Linus Torvalds 已提交
6350

6351
	dev->gso_max_size = GSO_MAX_SIZE;
6352
	dev->gso_max_segs = GSO_MAX_SEGS;
6353 6354 6355

	INIT_LIST_HEAD(&dev->napi_list);
	INIT_LIST_HEAD(&dev->unreg_list);
6356
	INIT_LIST_HEAD(&dev->close_list);
6357
	INIT_LIST_HEAD(&dev->link_watch_list);
6358 6359 6360 6361
	INIT_LIST_HEAD(&dev->adj_list.upper);
	INIT_LIST_HEAD(&dev->adj_list.lower);
	INIT_LIST_HEAD(&dev->all_adj_list.upper);
	INIT_LIST_HEAD(&dev->all_adj_list.lower);
6362 6363 6364
	dev->priv_flags = IFF_XMIT_DST_RELEASE;
	setup(dev);

T
Tom Herbert 已提交
6365 6366
	dev->num_tx_queues = txqs;
	dev->real_num_tx_queues = txqs;
6367
	if (netif_alloc_netdev_queues(dev))
6368
		goto free_all;
6369

6370
#ifdef CONFIG_SYSFS
T
Tom Herbert 已提交
6371 6372
	dev->num_rx_queues = rxqs;
	dev->real_num_rx_queues = rxqs;
T
Tom Herbert 已提交
6373
	if (netif_alloc_rx_queues(dev))
6374
		goto free_all;
E
Eric Dumazet 已提交
6375
#endif
T
Tom Herbert 已提交
6376

L
Linus Torvalds 已提交
6377
	strcpy(dev->name, name);
6378
	dev->group = INIT_NETDEV_GROUP;
6379 6380
	if (!dev->ethtool_ops)
		dev->ethtool_ops = &default_ethtool_ops;
L
Linus Torvalds 已提交
6381
	return dev;
6382

6383 6384 6385 6386
free_all:
	free_netdev(dev);
	return NULL;

E
Eric Dumazet 已提交
6387 6388
free_pcpu:
	free_percpu(dev->pcpu_refcnt);
6389
	netif_free_tx_queues(dev);
6390
#ifdef CONFIG_SYSFS
T
Tom Herbert 已提交
6391 6392 6393
	kfree(dev->_rx);
#endif

6394 6395
free_dev:
	netdev_freemem(dev);
6396
	return NULL;
L
Linus Torvalds 已提交
6397
}
T
Tom Herbert 已提交
6398
EXPORT_SYMBOL(alloc_netdev_mqs);
L
Linus Torvalds 已提交
6399 6400 6401 6402 6403

/**
 *	free_netdev - free network device
 *	@dev: device
 *
6404 6405
 *	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
6406 6407 6408 6409
 *	If this is the last reference then it will be freed.
 */
void free_netdev(struct net_device *dev)
{
6410 6411
	struct napi_struct *p, *n;

6412 6413
	release_net(dev_net(dev));

6414
	netif_free_tx_queues(dev);
6415
#ifdef CONFIG_SYSFS
T
Tom Herbert 已提交
6416 6417
	kfree(dev->_rx);
#endif
6418

6419
	kfree(rcu_dereference_protected(dev->ingress_queue, 1));
6420

6421 6422 6423
	/* Flush device addresses */
	dev_addr_flush(dev);

6424 6425 6426
	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
		netif_napi_del(p);

E
Eric Dumazet 已提交
6427 6428 6429
	free_percpu(dev->pcpu_refcnt);
	dev->pcpu_refcnt = NULL;

S
Stephen Hemminger 已提交
6430
	/*  Compatibility with error handling in drivers */
L
Linus Torvalds 已提交
6431
	if (dev->reg_state == NETREG_UNINITIALIZED) {
6432
		netdev_freemem(dev);
L
Linus Torvalds 已提交
6433 6434 6435 6436 6437 6438
		return;
	}

	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
	dev->reg_state = NETREG_RELEASED;

6439 6440
	/* will free via device release */
	put_device(&dev->dev);
L
Linus Torvalds 已提交
6441
}
E
Eric Dumazet 已提交
6442
EXPORT_SYMBOL(free_netdev);
6443

6444 6445 6446 6447 6448 6449
/**
 *	synchronize_net -  Synchronize with packet receive processing
 *
 *	Wait for packets currently being received to be done.
 *	Does not block later packets from starting.
 */
6450
void synchronize_net(void)
L
Linus Torvalds 已提交
6451 6452
{
	might_sleep();
6453 6454 6455 6456
	if (rtnl_is_locked())
		synchronize_rcu_expedited();
	else
		synchronize_rcu();
L
Linus Torvalds 已提交
6457
}
E
Eric Dumazet 已提交
6458
EXPORT_SYMBOL(synchronize_net);
L
Linus Torvalds 已提交
6459 6460

/**
6461
 *	unregister_netdevice_queue - remove device from the kernel
L
Linus Torvalds 已提交
6462
 *	@dev: device
6463
 *	@head: list
6464
 *
L
Linus Torvalds 已提交
6465
 *	This function shuts down a device interface and removes it
6466
 *	from the kernel tables.
6467
 *	If head not NULL, device is queued to be unregistered later.
L
Linus Torvalds 已提交
6468 6469 6470 6471 6472
 *
 *	Callers must hold the rtnl semaphore.  You may want
 *	unregister_netdev() instead of this.
 */

6473
void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
L
Linus Torvalds 已提交
6474
{
6475 6476
	ASSERT_RTNL();

6477
	if (head) {
6478
		list_move_tail(&dev->unreg_list, head);
6479 6480 6481 6482 6483
	} else {
		rollback_registered(dev);
		/* Finish processing unregister after unlock */
		net_set_todo(dev);
	}
L
Linus Torvalds 已提交
6484
}
6485
EXPORT_SYMBOL(unregister_netdevice_queue);
L
Linus Torvalds 已提交
6486

6487 6488 6489 6490 6491 6492 6493 6494 6495 6496 6497 6498 6499 6500
/**
 *	unregister_netdevice_many - unregister many devices
 *	@head: list of devices
 */
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);
	}
}
6501
EXPORT_SYMBOL(unregister_netdevice_many);
6502

L
Linus Torvalds 已提交
6503 6504 6505 6506 6507
/**
 *	unregister_netdev - remove device from the kernel
 *	@dev: device
 *
 *	This function shuts down a device interface and removes it
6508
 *	from the kernel tables.
L
Linus Torvalds 已提交
6509 6510 6511 6512 6513 6514 6515 6516 6517 6518 6519 6520 6521
 *
 *	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);

6522 6523 6524 6525 6526 6527 6528 6529 6530 6531 6532 6533 6534 6535 6536 6537 6538 6539 6540 6541 6542 6543 6544 6545 6546 6547 6548 6549 6550 6551 6552
/**
 *	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;
6553
	if (net_eq(dev_net(dev), net))
6554 6555 6556 6557 6558 6559
		goto out;

	/* Pick the destination device name, and ensure
	 * we can use it in the destination network namespace.
	 */
	err = -EEXIST;
6560
	if (__dev_get_by_name(net, dev->name)) {
6561 6562 6563
		/* We get here if we can't use the current device name */
		if (!pat)
			goto out;
6564
		if (dev_get_valid_name(net, dev, pat) < 0)
6565 6566 6567 6568 6569 6570 6571 6572
			goto out;
	}

	/*
	 * And now a mini version of register_netdevice unregister_netdevice.
	 */

	/* If device is running close it first. */
6573
	dev_close(dev);
6574 6575 6576 6577 6578 6579 6580 6581 6582 6583 6584 6585

	/* 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.
6586 6587 6588 6589

	   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.
6590 6591
	*/
	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
6592 6593
	rcu_barrier();
	call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
6594
	rtmsg_ifinfo(RTM_DELLINK, dev, ~0U, GFP_KERNEL);
6595 6596 6597 6598

	/*
	 *	Flush the unicast and multicast chains
	 */
6599
	dev_uc_flush(dev);
6600
	dev_mc_flush(dev);
6601

6602 6603 6604
	/* Send a netdev-removed uevent to the old namespace */
	kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);

6605
	/* Actually switch the network namespace */
6606
	dev_net_set(dev, net);
6607 6608 6609 6610 6611 6612 6613 6614 6615

	/* If there is an ifindex conflict assign a new one */
	if (__dev_get_by_index(net, dev->ifindex)) {
		int iflink = (dev->iflink == dev->ifindex);
		dev->ifindex = dev_new_index(net);
		if (iflink)
			dev->iflink = dev->ifindex;
	}

6616 6617 6618
	/* Send a netdev-add uevent to the new namespace */
	kobject_uevent(&dev->dev.kobj, KOBJ_ADD);

6619
	/* Fixup kobjects */
6620
	err = device_rename(&dev->dev, dev->name);
6621
	WARN_ON(err);
6622 6623 6624 6625 6626 6627 6628

	/* Add the device back in the hashes */
	list_netdevice(dev);

	/* Notify protocols, that a new device appeared. */
	call_netdevice_notifiers(NETDEV_REGISTER, dev);

6629 6630 6631 6632
	/*
	 *	Prevent userspace races by waiting until the network
	 *	device is fully setup before sending notifications.
	 */
6633
	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
6634

6635 6636 6637 6638 6639
	synchronize_net();
	err = 0;
out:
	return err;
}
6640
EXPORT_SYMBOL_GPL(dev_change_net_namespace);
6641

L
Linus Torvalds 已提交
6642 6643 6644 6645 6646 6647 6648 6649 6650
static int dev_cpu_callback(struct notifier_block *nfb,
			    unsigned long action,
			    void *ocpu)
{
	struct sk_buff **list_skb;
	struct sk_buff *skb;
	unsigned int cpu, oldcpu = (unsigned long)ocpu;
	struct softnet_data *sd, *oldsd;

6651
	if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
L
Linus Torvalds 已提交
6652 6653 6654 6655 6656 6657 6658 6659 6660 6661 6662 6663 6664 6665 6666 6667
		return NOTIFY_OK;

	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. */
6668 6669 6670 6671 6672 6673
	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;
	}
6674 6675 6676 6677 6678
	/* Append NAPI poll list from offline CPU. */
	if (!list_empty(&oldsd->poll_list)) {
		list_splice_init(&oldsd->poll_list, &sd->poll_list);
		raise_softirq_irqoff(NET_RX_SOFTIRQ);
	}
L
Linus Torvalds 已提交
6679 6680 6681 6682 6683

	raise_softirq_irqoff(NET_TX_SOFTIRQ);
	local_irq_enable();

	/* Process offline CPU's input_pkt_queue */
6684
	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
6685
		netif_rx_internal(skb);
6686
		input_queue_head_incr(oldsd);
T
Tom Herbert 已提交
6687
	}
6688
	while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
6689
		netif_rx_internal(skb);
6690 6691
		input_queue_head_incr(oldsd);
	}
L
Linus Torvalds 已提交
6692 6693 6694 6695 6696

	return NOTIFY_OK;
}


6697
/**
6698 6699 6700 6701
 *	netdev_increment_features - increment feature set by one
 *	@all: current feature set
 *	@one: new feature set
 *	@mask: mask feature set
6702 6703
 *
 *	Computes a new feature set after adding a device with feature set
6704 6705
 *	@one to the master device with current feature set @all.  Will not
 *	enable anything that is off in @mask. Returns the new feature set.
6706
 */
6707 6708
netdev_features_t netdev_increment_features(netdev_features_t all,
	netdev_features_t one, netdev_features_t mask)
6709
{
6710 6711 6712
	if (mask & NETIF_F_GEN_CSUM)
		mask |= NETIF_F_ALL_CSUM;
	mask |= NETIF_F_VLAN_CHALLENGED;
6713

6714 6715
	all |= one & (NETIF_F_ONE_FOR_ALL|NETIF_F_ALL_CSUM) & mask;
	all &= one | ~NETIF_F_ALL_FOR_ALL;
6716

6717 6718 6719
	/* If one device supports hw checksumming, set for all. */
	if (all & NETIF_F_GEN_CSUM)
		all &= ~(NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM);
6720 6721 6722

	return all;
}
6723
EXPORT_SYMBOL(netdev_increment_features);
6724

6725
static struct hlist_head * __net_init netdev_create_hash(void)
6726 6727 6728 6729 6730 6731 6732 6733 6734 6735 6736 6737
{
	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;
}

6738
/* Initialize per network namespace state */
6739
static int __net_init netdev_init(struct net *net)
6740
{
6741 6742
	if (net != &init_net)
		INIT_LIST_HEAD(&net->dev_base_head);
6743

6744 6745 6746
	net->dev_name_head = netdev_create_hash();
	if (net->dev_name_head == NULL)
		goto err_name;
6747

6748 6749 6750
	net->dev_index_head = netdev_create_hash();
	if (net->dev_index_head == NULL)
		goto err_idx;
6751 6752

	return 0;
6753 6754 6755 6756 6757

err_idx:
	kfree(net->dev_name_head);
err_name:
	return -ENOMEM;
6758 6759
}

6760 6761 6762 6763 6764 6765
/**
 *	netdev_drivername - network driver for the device
 *	@dev: network device
 *
 *	Determine network driver for device.
 */
6766
const char *netdev_drivername(const struct net_device *dev)
6767
{
6768 6769
	const struct device_driver *driver;
	const struct device *parent;
6770
	const char *empty = "";
6771 6772 6773

	parent = dev->dev.parent;
	if (!parent)
6774
		return empty;
6775 6776 6777

	driver = parent->driver;
	if (driver && driver->name)
6778 6779
		return driver->name;
	return empty;
6780 6781
}

6782
static int __netdev_printk(const char *level, const struct net_device *dev,
6783 6784 6785 6786
			   struct va_format *vaf)
{
	int r;

6787
	if (dev && dev->dev.parent) {
6788 6789 6790 6791 6792 6793
		r = dev_printk_emit(level[1] - '0',
				    dev->dev.parent,
				    "%s %s %s: %pV",
				    dev_driver_string(dev->dev.parent),
				    dev_name(dev->dev.parent),
				    netdev_name(dev), vaf);
6794
	} else if (dev) {
6795
		r = printk("%s%s: %pV", level, netdev_name(dev), vaf);
6796
	} else {
6797
		r = printk("%s(NULL net_device): %pV", level, vaf);
6798
	}
6799 6800 6801 6802 6803 6804 6805 6806 6807 6808 6809 6810 6811 6812 6813 6814 6815

	return r;
}

int netdev_printk(const char *level, const struct net_device *dev,
		  const char *format, ...)
{
	struct va_format vaf;
	va_list args;
	int r;

	va_start(args, format);

	vaf.fmt = format;
	vaf.va = &args;

	r = __netdev_printk(level, dev, &vaf);
6816

6817 6818 6819 6820 6821 6822 6823 6824 6825 6826 6827 6828 6829 6830 6831 6832 6833 6834 6835
	va_end(args);

	return r;
}
EXPORT_SYMBOL(netdev_printk);

#define define_netdev_printk_level(func, level)			\
int func(const struct net_device *dev, const char *fmt, ...)	\
{								\
	int r;							\
	struct va_format vaf;					\
	va_list args;						\
								\
	va_start(args, fmt);					\
								\
	vaf.fmt = fmt;						\
	vaf.va = &args;						\
								\
	r = __netdev_printk(level, dev, &vaf);			\
6836
								\
6837 6838 6839 6840 6841 6842 6843 6844 6845 6846 6847 6848 6849 6850
	va_end(args);						\
								\
	return r;						\
}								\
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);

6851
static void __net_exit netdev_exit(struct net *net)
6852 6853 6854 6855 6856
{
	kfree(net->dev_name_head);
	kfree(net->dev_index_head);
}

6857
static struct pernet_operations __net_initdata netdev_net_ops = {
6858 6859 6860 6861
	.init = netdev_init,
	.exit = netdev_exit,
};

6862
static void __net_exit default_device_exit(struct net *net)
6863
{
6864
	struct net_device *dev, *aux;
6865
	/*
6866
	 * Push all migratable network devices back to the
6867 6868 6869
	 * initial network namespace
	 */
	rtnl_lock();
6870
	for_each_netdev_safe(net, dev, aux) {
6871
		int err;
6872
		char fb_name[IFNAMSIZ];
6873 6874 6875 6876 6877

		/* Ignore unmoveable devices (i.e. loopback) */
		if (dev->features & NETIF_F_NETNS_LOCAL)
			continue;

6878 6879 6880
		/* Leave virtual devices for the generic cleanup */
		if (dev->rtnl_link_ops)
			continue;
6881

L
Lucas De Marchi 已提交
6882
		/* Push remaining network devices to init_net */
6883 6884
		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
		err = dev_change_net_namespace(dev, &init_net, fb_name);
6885
		if (err) {
6886 6887
			pr_emerg("%s: failed to move %s to init_net: %d\n",
				 __func__, dev->name, err);
6888
			BUG();
6889 6890 6891 6892 6893
		}
	}
	rtnl_unlock();
}

6894 6895 6896 6897 6898 6899 6900 6901 6902 6903 6904 6905 6906 6907 6908 6909 6910 6911 6912 6913 6914 6915 6916 6917 6918 6919 6920 6921
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;
	DEFINE_WAIT(wait);

	for (;;) {
		prepare_to_wait(&netdev_unregistering_wq, &wait,
				TASK_UNINTERRUPTIBLE);
		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();
		schedule();
	}
	finish_wait(&netdev_unregistering_wq, &wait);
}

6922 6923 6924
static void __net_exit default_device_exit_batch(struct list_head *net_list)
{
	/* At exit all network devices most be removed from a network
6925
	 * namespace.  Do this in the reverse order of registration.
6926 6927 6928 6929 6930 6931 6932
	 * 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);

6933 6934 6935 6936 6937 6938 6939 6940 6941 6942 6943 6944
	/* 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);
6945 6946 6947 6948 6949 6950 6951 6952 6953
	list_for_each_entry(net, net_list, exit_list) {
		for_each_netdev_reverse(net, dev) {
			if (dev->rtnl_link_ops)
				dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
			else
				unregister_netdevice_queue(dev, &dev_kill_list);
		}
	}
	unregister_netdevice_many(&dev_kill_list);
E
Eric Dumazet 已提交
6954
	list_del(&dev_kill_list);
6955 6956 6957
	rtnl_unlock();
}

6958
static struct pernet_operations __net_initdata default_device_ops = {
6959
	.exit = default_device_exit,
6960
	.exit_batch = default_device_exit_batch,
6961 6962
};

L
Linus Torvalds 已提交
6963 6964 6965 6966 6967 6968 6969 6970 6971 6972 6973 6974 6975 6976 6977 6978 6979 6980 6981 6982
/*
 *	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;

6983
	if (netdev_kobject_init())
L
Linus Torvalds 已提交
6984 6985 6986
		goto out;

	INIT_LIST_HEAD(&ptype_all);
6987
	for (i = 0; i < PTYPE_HASH_SIZE; i++)
L
Linus Torvalds 已提交
6988 6989
		INIT_LIST_HEAD(&ptype_base[i]);

6990 6991
	INIT_LIST_HEAD(&offload_base);

6992 6993
	if (register_pernet_subsys(&netdev_net_ops))
		goto out;
L
Linus Torvalds 已提交
6994 6995 6996 6997 6998

	/*
	 *	Initialise the packet receive queues.
	 */

6999
	for_each_possible_cpu(i) {
E
Eric Dumazet 已提交
7000
		struct softnet_data *sd = &per_cpu(softnet_data, i);
L
Linus Torvalds 已提交
7001

E
Eric Dumazet 已提交
7002
		skb_queue_head_init(&sd->input_pkt_queue);
7003
		skb_queue_head_init(&sd->process_queue);
E
Eric Dumazet 已提交
7004
		INIT_LIST_HEAD(&sd->poll_list);
7005
		sd->output_queue_tailp = &sd->output_queue;
E
Eric Dumazet 已提交
7006
#ifdef CONFIG_RPS
E
Eric Dumazet 已提交
7007 7008 7009
		sd->csd.func = rps_trigger_softirq;
		sd->csd.info = sd;
		sd->cpu = i;
7010
#endif
T
Tom Herbert 已提交
7011

E
Eric Dumazet 已提交
7012 7013
		sd->backlog.poll = process_backlog;
		sd->backlog.weight = weight_p;
L
Linus Torvalds 已提交
7014 7015 7016 7017
	}

	dev_boot_phase = 0;

7018 7019 7020 7021 7022 7023 7024 7025 7026 7027 7028 7029 7030 7031 7032
	/* 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;

7033 7034
	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
L
Linus Torvalds 已提交
7035 7036 7037 7038 7039 7040 7041 7042 7043

	hotcpu_notifier(dev_cpu_callback, 0);
	dst_init();
	rc = 0;
out:
	return rc;
}

subsys_initcall(net_dev_init);