dev.c 172.5 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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/*
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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));
549
			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] != ' ' &&
574
		    !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
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EXPORT_SYMBOL(netdev_boot_setup_check);
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/**
 *	netdev_boot_base	- get address from boot time settings
 *	@prefix: prefix for network device
 *	@unit: id for network device
 *
 * 	Check boot time settings for the base address of device.
 *	The found settings are set for the device to be used
 *	later in the device probing.
 *	Returns 0 if no settings found.
 */
unsigned long netdev_boot_base(const char *prefix, int unit)
{
	const struct netdev_boot_setup *s = dev_boot_setup;
	char name[IFNAMSIZ];
	int i;

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

	/*
	 * If device already registered then return base of 1
	 * to indicate not to probe for this interface
	 */
609
	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
655
 *	@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.
 */

665
struct net_device *__dev_get_by_name(struct net *net, const char *name)
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{
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	struct net_device *dev;
	struct hlist_head *head = dev_name_hash(net, name);
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669

670
	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
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EXPORT_SYMBOL(__dev_get_by_name);
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678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694
/**
 *	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);

695
	hlist_for_each_entry_rcu(dev, head, name_hlist)
696 697 698 699 700 701 702
		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
705
 *	@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.
 */

715
struct net_device *dev_get_by_name(struct net *net, const char *name)
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{
	struct net_device *dev;

719 720
	rcu_read_lock();
	dev = dev_get_by_name_rcu(net, name);
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	if (dev)
		dev_hold(dev);
723
	rcu_read_unlock();
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	return dev;
}
E
Eric Dumazet 已提交
726
EXPORT_SYMBOL(dev_get_by_name);
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/**
 *	__dev_get_by_index - find a device by its ifindex
730
 *	@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.
 */

740
struct net_device *__dev_get_by_index(struct net *net, int ifindex)
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{
E
Eric Dumazet 已提交
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	struct net_device *dev;
	struct hlist_head *head = dev_index_hash(net, ifindex);
L
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744

745
	hlist_for_each_entry(dev, head, index_hlist)
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746 747
		if (dev->ifindex == ifindex)
			return dev;
E
Eric Dumazet 已提交
748

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749 750
	return NULL;
}
E
Eric Dumazet 已提交
751
EXPORT_SYMBOL(__dev_get_by_index);
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753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768
/**
 *	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);

769
	hlist_for_each_entry_rcu(dev, head, index_hlist)
770 771 772 773 774 775 776
		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
780
 *	@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.
 */

789
struct net_device *dev_get_by_index(struct net *net, int ifindex)
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{
	struct net_device *dev;

793 794
	rcu_read_lock();
	dev = dev_get_by_index_rcu(net, ifindex);
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	if (dev)
		dev_hold(dev);
797
	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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802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835
/**
 *	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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/**
837
 *	dev_getbyhwaddr_rcu - find a device by its hardware address
838
 *	@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.
845
 *	The returned device has not had its ref count increased
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 *	and the caller must therefore be careful about locking
 *
 */

850 851
struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
				       const char *ha)
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{
	struct net_device *dev;

855
	for_each_netdev_rcu(net, dev)
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		if (dev->type == type &&
		    !memcmp(dev->dev_addr, ha, dev->addr_len))
858 859 860
			return dev;

	return NULL;
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}
862
EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
863

864
struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type)
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{
	struct net_device *dev;

868
	ASSERT_RTNL();
869
	for_each_netdev(net, dev)
870
		if (dev->type == type)
871 872 873
			return dev;

	return NULL;
874 875 876
}
EXPORT_SYMBOL(__dev_getfirstbyhwtype);

877
struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
878
{
879
	struct net_device *dev, *ret = NULL;
880

881 882 883 884 885 886 887 888 889
	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
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 *	dev_get_by_flags_rcu - find any device with given flags
895
 *	@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.
L
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 */

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struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags,
E
Eric Dumazet 已提交
905
				    unsigned short mask)
L
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906
{
907
	struct net_device *dev, *ret;
L
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908

909
	ret = NULL;
910
	for_each_netdev_rcu(net, dev) {
L
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911
		if (((dev->flags ^ if_flags) & mask) == 0) {
912
			ret = dev;
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913 914 915
			break;
		}
	}
916
	return ret;
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917
}
E
Eric Dumazet 已提交
918
EXPORT_SYMBOL(dev_get_by_flags_rcu);
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919 920 921 922 923 924

/**
 *	dev_valid_name - check if name is okay for network device
 *	@name: name string
 *
 *	Network device names need to be valid file names to
925 926
 *	to allow sysfs to work.  We also disallow any kind of
 *	whitespace.
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 */
928
bool dev_valid_name(const char *name)
L
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{
930
	if (*name == '\0')
931
		return false;
932
	if (strlen(name) >= IFNAMSIZ)
933
		return false;
934
	if (!strcmp(name, ".") || !strcmp(name, ".."))
935
		return false;
936 937 938

	while (*name) {
		if (*name == '/' || isspace(*name))
939
			return false;
940 941
		name++;
	}
942
	return true;
L
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943
}
E
Eric Dumazet 已提交
944
EXPORT_SYMBOL(dev_valid_name);
L
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945 946

/**
947 948
 *	__dev_alloc_name - allocate a name for a device
 *	@net: network namespace to allocate the device name in
L
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949
 *	@name: name format string
950
 *	@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
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 *	id. It scans list of devices to build up a free map, then chooses
 *	the first empty slot. The caller must hold the dev_base or rtnl lock
 *	while allocating the name and adding the device in order to avoid
 *	duplicates.
 *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
 *	Returns the number of the unit assigned or a negative errno code.
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 */

961
static int __dev_alloc_name(struct net *net, const char *name, char *buf)
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962 963 964 965
{
	int i = 0;
	const char *p;
	const int max_netdevices = 8*PAGE_SIZE;
S
Stephen Hemminger 已提交
966
	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
980
		inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
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		if (!inuse)
			return -ENOMEM;

984
		for_each_netdev(net, d) {
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			if (!sscanf(d->name, name, &i))
				continue;
			if (i < 0 || i >= max_netdevices)
				continue;

			/*  avoid cases where sscanf is not exact inverse of printf */
991
			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);
	}

1000 1001
	if (buf != name)
		snprintf(buf, IFNAMSIZ, name, i);
1002
	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;
}

1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031
/**
 *	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;

1032 1033
	BUG_ON(!dev_net(dev));
	net = dev_net(dev);
1034 1035 1036 1037 1038
	ret = __dev_alloc_name(net, name, buf);
	if (ret >= 0)
		strlcpy(dev->name, buf, IFNAMSIZ);
	return ret;
}
E
Eric Dumazet 已提交
1039
EXPORT_SYMBOL(dev_alloc_name);
1040

1041 1042 1043
static int dev_alloc_name_ns(struct net *net,
			     struct net_device *dev,
			     const char *name)
1044
{
1045 1046
	char buf[IFNAMSIZ];
	int ret;
1047

1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058
	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);
1059

1060 1061 1062
	if (!dev_valid_name(name))
		return -EINVAL;

1063
	if (strchr(name, '%'))
1064
		return dev_alloc_name_ns(net, dev, name);
1065 1066
	else if (__dev_get_by_name(net, name))
		return -EEXIST;
1067 1068
	else if (dev->name != name)
		strlcpy(dev->name, name, IFNAMSIZ);
1069 1070 1071

	return 0;
}
L
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1072 1073 1074 1075 1076 1077 1078 1079 1080

/**
 *	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.
 */
1081
int dev_change_name(struct net_device *dev, const char *newname)
L
Linus Torvalds 已提交
1082
{
1083
	char oldname[IFNAMSIZ];
L
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1084
	int err = 0;
1085
	int ret;
1086
	struct net *net;
L
Linus Torvalds 已提交
1087 1088

	ASSERT_RTNL();
1089
	BUG_ON(!dev_net(dev));
L
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1090

1091
	net = dev_net(dev);
L
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1092 1093 1094
	if (dev->flags & IFF_UP)
		return -EBUSY;

1095
	write_seqcount_begin(&devnet_rename_seq);
1096 1097

	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1098
		write_seqcount_end(&devnet_rename_seq);
1099
		return 0;
1100
	}
1101

1102 1103
	memcpy(oldname, dev->name, IFNAMSIZ);

1104
	err = dev_get_valid_name(net, dev, newname);
1105
	if (err < 0) {
1106
		write_seqcount_end(&devnet_rename_seq);
1107
		return err;
1108
	}
L
Linus Torvalds 已提交
1109

1110
rollback:
1111 1112 1113
	ret = device_rename(&dev->dev, dev->name);
	if (ret) {
		memcpy(dev->name, oldname, IFNAMSIZ);
1114
		write_seqcount_end(&devnet_rename_seq);
1115
		return ret;
1116
	}
1117

1118
	write_seqcount_end(&devnet_rename_seq);
1119

1120
	write_lock_bh(&dev_base_lock);
1121
	hlist_del_rcu(&dev->name_hlist);
1122 1123 1124 1125 1126 1127
	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));
1128 1129
	write_unlock_bh(&dev_base_lock);

1130
	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1131 1132 1133
	ret = notifier_to_errno(ret);

	if (ret) {
1134 1135
		/* err >= 0 after dev_alloc_name() or stores the first errno */
		if (err >= 0) {
1136
			err = ret;
1137
			write_seqcount_begin(&devnet_rename_seq);
1138 1139
			memcpy(dev->name, oldname, IFNAMSIZ);
			goto rollback;
1140
		} else {
1141
			pr_err("%s: name change rollback failed: %d\n",
1142
			       dev->name, ret);
1143 1144
		}
	}
L
Linus Torvalds 已提交
1145 1146 1147 1148

	return err;
}

1149 1150 1151 1152
/**
 *	dev_set_alias - change ifalias of a device
 *	@dev: device
 *	@alias: name up to IFALIASZ
1153
 *	@len: limit of bytes to copy from info
1154 1155 1156 1157 1158
 *
 *	Set ifalias for a device,
 */
int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
{
1159 1160
	char *new_ifalias;

1161 1162 1163 1164 1165
	ASSERT_RTNL();

	if (len >= IFALIASZ)
		return -EINVAL;

1166
	if (!len) {
1167 1168
		kfree(dev->ifalias);
		dev->ifalias = NULL;
1169 1170 1171
		return 0;
	}

1172 1173
	new_ifalias = krealloc(dev->ifalias, len + 1, GFP_KERNEL);
	if (!new_ifalias)
1174
		return -ENOMEM;
1175
	dev->ifalias = new_ifalias;
1176 1177 1178 1179 1180 1181

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


1182
/**
S
Stephen Hemminger 已提交
1183
 *	netdev_features_change - device changes features
1184 1185 1186 1187 1188 1189
 *	@dev: device to cause notification
 *
 *	Called to indicate a device has changed features.
 */
void netdev_features_change(struct net_device *dev)
{
1190
	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1191 1192 1193
}
EXPORT_SYMBOL(netdev_features_change);

L
Linus Torvalds 已提交
1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204
/**
 *	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) {
1205
		call_netdevice_notifiers(NETDEV_CHANGE, dev);
1206
		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);
L
Linus Torvalds 已提交
1207 1208
	}
}
E
Eric Dumazet 已提交
1209
EXPORT_SYMBOL(netdev_state_change);
L
Linus Torvalds 已提交
1210

1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221
/**
 * 	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)
1222
{
1223 1224 1225
	rtnl_lock();
	call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
	rtnl_unlock();
1226
}
1227
EXPORT_SYMBOL(netdev_notify_peers);
1228

1229
static int __dev_open(struct net_device *dev)
L
Linus Torvalds 已提交
1230
{
1231
	const struct net_device_ops *ops = dev->netdev_ops;
1232
	int ret;
L
Linus Torvalds 已提交
1233

1234 1235
	ASSERT_RTNL();

L
Linus Torvalds 已提交
1236 1237 1238
	if (!netif_device_present(dev))
		return -ENODEV;

1239 1240 1241 1242
	/* 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
	 */
1243
	netpoll_rx_disable(dev);
1244

1245 1246 1247 1248 1249
	ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
	ret = notifier_to_errno(ret);
	if (ret)
		return ret;

L
Linus Torvalds 已提交
1250
	set_bit(__LINK_STATE_START, &dev->state);
1251

1252 1253
	if (ops->ndo_validate_addr)
		ret = ops->ndo_validate_addr(dev);
1254

1255 1256
	if (!ret && ops->ndo_open)
		ret = ops->ndo_open(dev);
L
Linus Torvalds 已提交
1257

1258 1259
	netpoll_rx_enable(dev);

1260 1261 1262
	if (ret)
		clear_bit(__LINK_STATE_START, &dev->state);
	else {
L
Linus Torvalds 已提交
1263
		dev->flags |= IFF_UP;
1264
		net_dmaengine_get();
1265
		dev_set_rx_mode(dev);
L
Linus Torvalds 已提交
1266
		dev_activate(dev);
1267
		add_device_randomness(dev->dev_addr, dev->addr_len);
L
Linus Torvalds 已提交
1268
	}
1269

L
Linus Torvalds 已提交
1270 1271 1272 1273
	return ret;
}

/**
1274 1275
 *	dev_open	- prepare an interface for use.
 *	@dev:	device to open
L
Linus Torvalds 已提交
1276
 *
1277 1278 1279 1280 1281 1282 1283
 *	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
1284
 */
1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295
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;

1296
	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1297 1298 1299 1300 1301 1302
	call_netdevice_notifiers(NETDEV_UP, dev);

	return ret;
}
EXPORT_SYMBOL(dev_open);

1303
static int __dev_close_many(struct list_head *head)
L
Linus Torvalds 已提交
1304
{
1305
	struct net_device *dev;
1306

1307
	ASSERT_RTNL();
1308 1309
	might_sleep();

1310
	list_for_each_entry(dev, head, close_list) {
1311
		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
L
Linus Torvalds 已提交
1312

1313
		clear_bit(__LINK_STATE_START, &dev->state);
L
Linus Torvalds 已提交
1314

1315 1316 1317 1318 1319 1320 1321 1322
		/* 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
1323

1324
	dev_deactivate_many(head);
1325

1326
	list_for_each_entry(dev, head, close_list) {
1327
		const struct net_device_ops *ops = dev->netdev_ops;
L
Linus Torvalds 已提交
1328

1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347
		/*
		 *	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)
{
1348
	int retval;
1349 1350
	LIST_HEAD(single);

1351
	/* Temporarily disable netpoll until the interface is down */
1352
	netpoll_rx_disable(dev);
1353

1354
	list_add(&dev->close_list, &single);
1355 1356
	retval = __dev_close_many(&single);
	list_del(&single);
1357 1358

	netpoll_rx_enable(dev);
1359
	return retval;
1360 1361
}

E
Eric Dumazet 已提交
1362
static int dev_close_many(struct list_head *head)
1363 1364
{
	struct net_device *dev, *tmp;
L
Linus Torvalds 已提交
1365

1366 1367
	/* Remove the devices that don't need to be closed */
	list_for_each_entry_safe(dev, tmp, head, close_list)
1368
		if (!(dev->flags & IFF_UP))
1369
			list_del_init(&dev->close_list);
1370 1371

	__dev_close_many(head);
L
Linus Torvalds 已提交
1372

1373
	list_for_each_entry_safe(dev, tmp, head, close_list) {
1374
		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1375
		call_netdevice_notifiers(NETDEV_DOWN, dev);
1376
		list_del_init(&dev->close_list);
1377
	}
1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392

	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)
{
1393 1394
	if (dev->flags & IFF_UP) {
		LIST_HEAD(single);
L
Linus Torvalds 已提交
1395

1396
		/* Block netpoll rx while the interface is going down */
1397
		netpoll_rx_disable(dev);
1398

1399
		list_add(&dev->close_list, &single);
1400 1401
		dev_close_many(&single);
		list_del(&single);
1402 1403

		netpoll_rx_enable(dev);
1404
	}
1405
	return 0;
L
Linus Torvalds 已提交
1406
}
E
Eric Dumazet 已提交
1407
EXPORT_SYMBOL(dev_close);
L
Linus Torvalds 已提交
1408 1409


1410 1411 1412 1413 1414 1415 1416 1417 1418 1419
/**
 *	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)
{
1420 1421 1422 1423 1424 1425 1426
	/*
	 * 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);

1427 1428 1429 1430
	/* the same for macvlan devices */
	if (netif_is_macvlan(dev))
		dev = macvlan_dev_real_dev(dev);

M
Michał Mirosław 已提交
1431 1432
	dev->wanted_features &= ~NETIF_F_LRO;
	netdev_update_features(dev);
1433

1434 1435
	if (unlikely(dev->features & NETIF_F_LRO))
		netdev_WARN(dev, "failed to disable LRO!\n");
1436 1437 1438
}
EXPORT_SYMBOL(dev_disable_lro);

1439 1440 1441 1442 1443 1444 1445 1446
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);
}
1447

1448 1449
static int dev_boot_phase = 1;

L
Linus Torvalds 已提交
1450 1451 1452 1453 1454 1455 1456 1457 1458 1459
/**
 *	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
1460
 *	to the new notifier to allow device to have a race free
L
Linus Torvalds 已提交
1461 1462 1463 1464 1465 1466
 *	view of the network device list.
 */

int register_netdevice_notifier(struct notifier_block *nb)
{
	struct net_device *dev;
1467
	struct net_device *last;
1468
	struct net *net;
L
Linus Torvalds 已提交
1469 1470 1471
	int err;

	rtnl_lock();
1472
	err = raw_notifier_chain_register(&netdev_chain, nb);
1473 1474
	if (err)
		goto unlock;
1475 1476 1477 1478
	if (dev_boot_phase)
		goto unlock;
	for_each_net(net) {
		for_each_netdev(net, dev) {
1479
			err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1480 1481 1482 1483 1484 1485
			err = notifier_to_errno(err);
			if (err)
				goto rollback;

			if (!(dev->flags & IFF_UP))
				continue;
L
Linus Torvalds 已提交
1486

1487
			call_netdevice_notifier(nb, NETDEV_UP, dev);
1488
		}
L
Linus Torvalds 已提交
1489
	}
1490 1491

unlock:
L
Linus Torvalds 已提交
1492 1493
	rtnl_unlock();
	return err;
1494 1495 1496

rollback:
	last = dev;
1497 1498 1499
	for_each_net(net) {
		for_each_netdev(net, dev) {
			if (dev == last)
1500
				goto outroll;
1501

1502
			if (dev->flags & IFF_UP) {
1503 1504 1505
				call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
							dev);
				call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1506
			}
1507
			call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1508 1509
		}
	}
1510

1511
outroll:
1512
	raw_notifier_chain_unregister(&netdev_chain, nb);
1513
	goto unlock;
L
Linus Torvalds 已提交
1514
}
E
Eric Dumazet 已提交
1515
EXPORT_SYMBOL(register_netdevice_notifier);
L
Linus Torvalds 已提交
1516 1517 1518 1519 1520 1521 1522 1523 1524

/**
 *	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.
1525 1526 1527 1528
 *
 * 	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
1529 1530 1531 1532
 */

int unregister_netdevice_notifier(struct notifier_block *nb)
{
1533 1534
	struct net_device *dev;
	struct net *net;
1535 1536 1537
	int err;

	rtnl_lock();
1538
	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1539 1540 1541 1542 1543 1544
	if (err)
		goto unlock;

	for_each_net(net) {
		for_each_netdev(net, dev) {
			if (dev->flags & IFF_UP) {
1545 1546 1547
				call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
							dev);
				call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1548
			}
1549
			call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1550 1551 1552
		}
	}
unlock:
1553 1554
	rtnl_unlock();
	return err;
L
Linus Torvalds 已提交
1555
}
E
Eric Dumazet 已提交
1556
EXPORT_SYMBOL(unregister_netdevice_notifier);
L
Linus Torvalds 已提交
1557

1558 1559 1560 1561 1562 1563 1564 1565 1566 1567
/**
 *	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
1568 1569 1570
static int call_netdevice_notifiers_info(unsigned long val,
					 struct net_device *dev,
					 struct netdev_notifier_info *info)
1571 1572 1573 1574 1575 1576
{
	ASSERT_RTNL();
	netdev_notifier_info_init(info, dev);
	return raw_notifier_call_chain(&netdev_chain, val, info);
}

L
Linus Torvalds 已提交
1577 1578 1579
/**
 *	call_netdevice_notifiers - call all network notifier blocks
 *      @val: value passed unmodified to notifier function
1580
 *      @dev: net_device pointer passed unmodified to notifier function
L
Linus Torvalds 已提交
1581 1582
 *
 *	Call all network notifier blocks.  Parameters and return value
1583
 *	are as for raw_notifier_call_chain().
L
Linus Torvalds 已提交
1584 1585
 */

1586
int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
L
Linus Torvalds 已提交
1587
{
1588 1589 1590
	struct netdev_notifier_info info;

	return call_netdevice_notifiers_info(val, dev, &info);
L
Linus Torvalds 已提交
1591
}
1592
EXPORT_SYMBOL(call_netdevice_notifiers);
L
Linus Torvalds 已提交
1593

1594
static struct static_key netstamp_needed __read_mostly;
1595
#ifdef HAVE_JUMP_LABEL
1596
/* We are not allowed to call static_key_slow_dec() from irq context
1597
 * If net_disable_timestamp() is called from irq context, defer the
1598
 * static_key_slow_dec() calls.
1599 1600 1601
 */
static atomic_t netstamp_needed_deferred;
#endif
L
Linus Torvalds 已提交
1602 1603 1604

void net_enable_timestamp(void)
{
1605 1606 1607 1608 1609
#ifdef HAVE_JUMP_LABEL
	int deferred = atomic_xchg(&netstamp_needed_deferred, 0);

	if (deferred) {
		while (--deferred)
1610
			static_key_slow_dec(&netstamp_needed);
1611 1612 1613
		return;
	}
#endif
1614
	static_key_slow_inc(&netstamp_needed);
L
Linus Torvalds 已提交
1615
}
E
Eric Dumazet 已提交
1616
EXPORT_SYMBOL(net_enable_timestamp);
L
Linus Torvalds 已提交
1617 1618 1619

void net_disable_timestamp(void)
{
1620 1621 1622 1623 1624 1625
#ifdef HAVE_JUMP_LABEL
	if (in_interrupt()) {
		atomic_inc(&netstamp_needed_deferred);
		return;
	}
#endif
1626
	static_key_slow_dec(&netstamp_needed);
L
Linus Torvalds 已提交
1627
}
E
Eric Dumazet 已提交
1628
EXPORT_SYMBOL(net_disable_timestamp);
L
Linus Torvalds 已提交
1629

E
Eric Dumazet 已提交
1630
static inline void net_timestamp_set(struct sk_buff *skb)
L
Linus Torvalds 已提交
1631
{
1632
	skb->tstamp.tv64 = 0;
1633
	if (static_key_false(&netstamp_needed))
1634
		__net_timestamp(skb);
L
Linus Torvalds 已提交
1635 1636
}

1637
#define net_timestamp_check(COND, SKB)			\
1638
	if (static_key_false(&netstamp_needed)) {		\
1639 1640 1641
		if ((COND) && !(SKB)->tstamp.tv64)	\
			__net_timestamp(SKB);		\
	}						\
E
Eric Dumazet 已提交
1642

1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663
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;
}

1664 1665 1666 1667 1668 1669 1670 1671
/**
 * dev_forward_skb - loopback an skb to another netif
 *
 * @dev: destination network device
 * @skb: buffer to forward
 *
 * return values:
 *	NET_RX_SUCCESS	(no congestion)
1672
 *	NET_RX_DROP     (packet was dropped, but freed)
1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683
 *
 * 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)
{
1684 1685 1686 1687 1688 1689 1690 1691
	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;
		}
	}

1692
	if (unlikely(!is_skb_forwardable(dev, skb))) {
1693
		atomic_long_inc(&dev->rx_dropped);
1694
		kfree_skb(skb);
1695
		return NET_RX_DROP;
1696
	}
1697

1698
	skb_scrub_packet(skb, true);
1699
	skb->protocol = eth_type_trans(skb, dev);
1700

1701 1702 1703 1704
	return netif_rx(skb);
}
EXPORT_SYMBOL_GPL(dev_forward_skb);

1705 1706 1707 1708
static inline int deliver_skb(struct sk_buff *skb,
			      struct packet_type *pt_prev,
			      struct net_device *orig_dev)
{
1709 1710
	if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
		return -ENOMEM;
1711 1712 1713 1714
	atomic_inc(&skb->users);
	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
}

1715 1716
static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
{
1717
	if (!ptype->af_packet_priv || !skb->sk)
1718 1719 1720 1721 1722 1723 1724 1725 1726 1727
		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
1728 1729 1730 1731 1732
/*
 *	Support routine. Sends outgoing frames to any network
 *	taps currently in use.
 */

1733
static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
L
Linus Torvalds 已提交
1734 1735
{
	struct packet_type *ptype;
1736 1737
	struct sk_buff *skb2 = NULL;
	struct packet_type *pt_prev = NULL;
1738

L
Linus Torvalds 已提交
1739 1740 1741 1742 1743 1744
	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) &&
1745
		    (!skb_loop_sk(ptype, skb))) {
1746 1747 1748 1749 1750 1751 1752
			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
1753 1754 1755
			if (!skb2)
				break;

1756 1757
			net_timestamp_set(skb2);

L
Linus Torvalds 已提交
1758 1759 1760 1761
			/* skb->nh should be correctly
			   set by sender, so that the second statement is
			   just protection against buggy protocols.
			 */
1762
			skb_reset_mac_header(skb2);
L
Linus Torvalds 已提交
1763

1764
			if (skb_network_header(skb2) < skb2->data ||
1765
			    skb_network_header(skb2) > skb_tail_pointer(skb2)) {
1766 1767 1768
				net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
						     ntohs(skb2->protocol),
						     dev->name);
1769
				skb_reset_network_header(skb2);
L
Linus Torvalds 已提交
1770 1771
			}

1772
			skb2->transport_header = skb2->network_header;
L
Linus Torvalds 已提交
1773
			skb2->pkt_type = PACKET_OUTGOING;
1774
			pt_prev = ptype;
L
Linus Torvalds 已提交
1775 1776
		}
	}
1777 1778
	if (pt_prev)
		pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
L
Linus Torvalds 已提交
1779 1780 1781
	rcu_read_unlock();
}

1782 1783
/**
 * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794
 * @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
1795
static void netif_setup_tc(struct net_device *dev, unsigned int txq)
1796 1797 1798 1799 1800 1801
{
	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) {
1802
		pr_warn("Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
1803 1804 1805 1806 1807 1808 1809 1810 1811 1812
		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) {
1813 1814
			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);
1815 1816 1817 1818 1819
			netdev_set_prio_tc_map(dev, i, 0);
		}
	}
}

1820 1821 1822 1823 1824
#ifdef CONFIG_XPS
static DEFINE_MUTEX(xps_map_mutex);
#define xmap_dereference(P)		\
	rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))

1825 1826
static struct xps_map *remove_xps_queue(struct xps_dev_maps *dev_maps,
					int cpu, u16 index)
1827
{
1828 1829
	struct xps_map *map = NULL;
	int pos;
1830

1831 1832
	if (dev_maps)
		map = xmap_dereference(dev_maps->cpu_map[cpu]);
1833

1834 1835
	for (pos = 0; map && pos < map->len; pos++) {
		if (map->queues[pos] == index) {
1836 1837 1838
			if (map->len > 1) {
				map->queues[pos] = map->queues[--map->len];
			} else {
1839
				RCU_INIT_POINTER(dev_maps->cpu_map[cpu], NULL);
1840 1841 1842
				kfree_rcu(map, rcu);
				map = NULL;
			}
1843
			break;
1844 1845 1846
		}
	}

1847 1848 1849
	return map;
}

1850
static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
1851 1852
{
	struct xps_dev_maps *dev_maps;
1853
	int cpu, i;
1854 1855 1856 1857 1858 1859 1860 1861 1862
	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) {
1863 1864 1865 1866 1867
		for (i = index; i < dev->num_tx_queues; i++) {
			if (!remove_xps_queue(dev_maps, cpu, i))
				break;
		}
		if (i == dev->num_tx_queues)
1868 1869 1870 1871
			active = true;
	}

	if (!active) {
1872 1873 1874 1875
		RCU_INIT_POINTER(dev->xps_maps, NULL);
		kfree_rcu(dev_maps, rcu);
	}

1876 1877 1878 1879
	for (i = index; i < dev->num_tx_queues; i++)
		netdev_queue_numa_node_write(netdev_get_tx_queue(dev, i),
					     NUMA_NO_NODE);

1880 1881 1882 1883
out_no_maps:
	mutex_unlock(&xps_map_mutex);
}

1884 1885 1886 1887 1888 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
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;
}

1919 1920
int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
			u16 index)
1921
{
1922
	struct xps_dev_maps *dev_maps, *new_dev_maps = NULL;
1923 1924
	struct xps_map *map, *new_map;
	int maps_sz = max_t(unsigned int, XPS_DEV_MAPS_SIZE, L1_CACHE_BYTES);
1925 1926
	int cpu, numa_node_id = -2;
	bool active = false;
1927 1928 1929 1930 1931

	mutex_lock(&xps_map_mutex);

	dev_maps = xmap_dereference(dev->xps_maps);

1932 1933 1934 1935 1936 1937 1938
	/* 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);
1939 1940
		if (!new_dev_maps) {
			mutex_unlock(&xps_map_mutex);
1941
			return -ENOMEM;
1942
		}
1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956

		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;

1957
	for_each_possible_cpu(cpu) {
1958 1959 1960 1961 1962 1963 1964 1965 1966 1967
		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;
1968 1969 1970 1971 1972 1973
#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
1974 1975 1976 1977
		} 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);
1978
		}
1979

1980 1981
	}

1982 1983
	rcu_assign_pointer(dev->xps_maps, new_dev_maps);

1984
	/* Cleanup old maps */
1985 1986 1987 1988 1989 1990 1991
	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);
		}
1992

1993
		kfree_rcu(dev_maps, rcu);
1994 1995
	}

1996 1997
	dev_maps = new_dev_maps;
	active = true;
1998

1999 2000
out_no_new_maps:
	/* update Tx queue numa node */
2001 2002 2003 2004
	netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
				     (numa_node_id >= 0) ? numa_node_id :
				     NUMA_NO_NODE);

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
	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:
2024 2025 2026 2027
	mutex_unlock(&xps_map_mutex);

	return 0;
error:
2028 2029 2030 2031 2032 2033 2034 2035 2036
	/* 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);
	}

2037 2038 2039 2040 2041 2042 2043 2044
	mutex_unlock(&xps_map_mutex);

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

#endif
2045 2046 2047 2048
/*
 * 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.
 */
2049
int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2050
{
T
Tom Herbert 已提交
2051 2052
	int rc;

2053 2054
	if (txq < 1 || txq > dev->num_tx_queues)
		return -EINVAL;
2055

2056 2057
	if (dev->reg_state == NETREG_REGISTERED ||
	    dev->reg_state == NETREG_UNREGISTERING) {
2058 2059
		ASSERT_RTNL();

T
Tom Herbert 已提交
2060 2061
		rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
						  txq);
T
Tom Herbert 已提交
2062 2063 2064
		if (rc)
			return rc;

2065 2066 2067
		if (dev->num_tc)
			netif_setup_tc(dev, txq);

2068
		if (txq < dev->real_num_tx_queues) {
2069
			qdisc_reset_all_tx_gt(dev, txq);
2070 2071 2072 2073
#ifdef CONFIG_XPS
			netif_reset_xps_queues_gt(dev, txq);
#endif
		}
2074
	}
2075 2076 2077

	dev->real_num_tx_queues = txq;
	return 0;
2078 2079
}
EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2080

2081 2082 2083 2084 2085 2086 2087 2088
#ifdef CONFIG_RPS
/**
 *	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
2089 2090
 *	negative error code.  If called before registration, it always
 *	succeeds.
2091 2092 2093 2094 2095
 */
int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
{
	int rc;

T
Tom Herbert 已提交
2096 2097 2098
	if (rxq < 1 || rxq > dev->num_rx_queues)
		return -EINVAL;

2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113
	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

2114 2115
/**
 * netif_get_num_default_rss_queues - default number of RSS queues
2116 2117 2118 2119
 *
 * This routine should set an upper limit on the number of RSS queues
 * used by default by multiqueue devices.
 */
2120
int netif_get_num_default_rss_queues(void)
2121 2122 2123 2124 2125
{
	return min_t(int, DEFAULT_MAX_NUM_RSS_QUEUES, num_online_cpus());
}
EXPORT_SYMBOL(netif_get_num_default_rss_queues);

2126
static inline void __netif_reschedule(struct Qdisc *q)
2127
{
2128 2129
	struct softnet_data *sd;
	unsigned long flags;
2130

2131 2132
	local_irq_save(flags);
	sd = &__get_cpu_var(softnet_data);
2133 2134 2135
	q->next_sched = NULL;
	*sd->output_queue_tailp = q;
	sd->output_queue_tailp = &q->next_sched;
2136 2137 2138 2139 2140 2141 2142 2143
	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);
2144 2145 2146
}
EXPORT_SYMBOL(__netif_schedule);

2147 2148 2149 2150 2151 2152 2153 2154 2155 2156
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)
2157
{
2158
	unsigned long flags;
2159

2160 2161 2162 2163 2164
	if (likely(atomic_read(&skb->users) == 1)) {
		smp_rmb();
		atomic_set(&skb->users, 0);
	} else if (likely(!atomic_dec_and_test(&skb->users))) {
		return;
2165
	}
2166 2167 2168 2169 2170 2171
	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);
2172
}
2173
EXPORT_SYMBOL(__dev_kfree_skb_irq);
2174

2175
void __dev_kfree_skb_any(struct sk_buff *skb, enum skb_free_reason reason)
2176 2177
{
	if (in_irq() || irqs_disabled())
2178
		__dev_kfree_skb_irq(skb, reason);
2179 2180 2181
	else
		dev_kfree_skb(skb);
}
2182
EXPORT_SYMBOL(__dev_kfree_skb_any);
2183 2184


2185 2186 2187 2188 2189 2190
/**
 * netif_device_detach - mark device as removed
 * @dev: network device
 *
 * Mark device as removed from system and therefore no longer available.
 */
2191 2192 2193 2194
void netif_device_detach(struct net_device *dev)
{
	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
	    netif_running(dev)) {
2195
		netif_tx_stop_all_queues(dev);
2196 2197 2198 2199
	}
}
EXPORT_SYMBOL(netif_device_detach);

2200 2201 2202 2203 2204 2205
/**
 * netif_device_attach - mark device as attached
 * @dev: network device
 *
 * Mark device as attached from system and restart if needed.
 */
2206 2207 2208 2209
void netif_device_attach(struct net_device *dev)
{
	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
	    netif_running(dev)) {
2210
		netif_tx_wake_all_queues(dev);
2211
		__netdev_watchdog_up(dev);
2212 2213 2214 2215
	}
}
EXPORT_SYMBOL(netif_device_attach);

2216 2217
static void skb_warn_bad_offload(const struct sk_buff *skb)
{
2218
	static const netdev_features_t null_features = 0;
2219 2220 2221
	struct net_device *dev = skb->dev;
	const char *driver = "";

2222 2223 2224
	if (!net_ratelimit())
		return;

2225 2226 2227 2228 2229
	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",
2230 2231
	     driver, dev ? &dev->features : &null_features,
	     skb->sk ? &skb->sk->sk_route_caps : &null_features,
2232 2233 2234 2235
	     skb->len, skb->data_len, skb_shinfo(skb)->gso_size,
	     skb_shinfo(skb)->gso_type, skb->ip_summed);
}

L
Linus Torvalds 已提交
2236 2237 2238 2239
/*
 * Invalidate hardware checksum when packet is to be mangled, and
 * complete checksum manually on outgoing path.
 */
2240
int skb_checksum_help(struct sk_buff *skb)
L
Linus Torvalds 已提交
2241
{
2242
	__wsum csum;
2243
	int ret = 0, offset;
L
Linus Torvalds 已提交
2244

2245
	if (skb->ip_summed == CHECKSUM_COMPLETE)
2246 2247 2248
		goto out_set_summed;

	if (unlikely(skb_shinfo(skb)->gso_size)) {
2249 2250
		skb_warn_bad_offload(skb);
		return -EINVAL;
L
Linus Torvalds 已提交
2251 2252
	}

2253 2254 2255 2256 2257 2258 2259 2260 2261
	/* 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;
	}

2262
	offset = skb_checksum_start_offset(skb);
2263 2264 2265 2266 2267 2268 2269 2270
	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
2271 2272 2273 2274 2275
		ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
		if (ret)
			goto out;
	}

2276
	*(__sum16 *)(skb->data + offset) = csum_fold(csum);
2277
out_set_summed:
L
Linus Torvalds 已提交
2278
	skb->ip_summed = CHECKSUM_NONE;
2279
out:
L
Linus Torvalds 已提交
2280 2281
	return ret;
}
E
Eric Dumazet 已提交
2282
EXPORT_SYMBOL(skb_checksum_help);
L
Linus Torvalds 已提交
2283

2284
__be16 skb_network_protocol(struct sk_buff *skb)
2285
{
A
Al Viro 已提交
2286
	__be16 type = skb->protocol;
2287
	int vlan_depth = ETH_HLEN;
2288

2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299
	/* 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
2300
	while (type == htons(ETH_P_8021Q) || type == htons(ETH_P_8021AD)) {
2301
		struct vlan_hdr *vh;
2302

2303
		if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
2304
			return 0;
2305

2306 2307 2308
		vh = (struct vlan_hdr *)(skb->data + vlan_depth);
		type = vh->h_vlan_encapsulated_proto;
		vlan_depth += VLAN_HLEN;
2309 2310
	}

2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328
	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);

2329 2330 2331
	__skb_pull(skb, skb->mac_len);

	rcu_read_lock();
2332
	list_for_each_entry_rcu(ptype, &offload_base, list) {
2333
		if (ptype->type == type && ptype->callbacks.gso_segment) {
2334
			if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
2335 2336
				int err;

2337
				err = ptype->callbacks.gso_send_check(skb);
2338 2339 2340
				segs = ERR_PTR(err);
				if (err || skb_gso_ok(skb, features))
					break;
2341 2342
				__skb_push(skb, (skb->data -
						 skb_network_header(skb)));
2343
			}
2344
			segs = ptype->callbacks.gso_segment(skb, features);
2345 2346 2347 2348 2349
			break;
		}
	}
	rcu_read_unlock();

2350
	__skb_push(skb, skb->data - skb_mac_header(skb));
2351

2352 2353
	return segs;
}
2354 2355 2356 2357 2358 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
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);
	}

2391
	SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
2392 2393
	SKB_GSO_CB(skb)->encap_level = 0;

2394 2395 2396 2397 2398
	skb_reset_mac_header(skb);
	skb_reset_mac_len(skb);

	return skb_mac_gso_segment(skb, features);
}
2399
EXPORT_SYMBOL(__skb_gso_segment);
2400

2401 2402 2403 2404 2405
/* Take action when hardware reception checksum errors are detected. */
#ifdef CONFIG_BUG
void netdev_rx_csum_fault(struct net_device *dev)
{
	if (net_ratelimit()) {
2406
		pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
2407 2408 2409 2410 2411 2412
		dump_stack();
	}
}
EXPORT_SYMBOL(netdev_rx_csum_fault);
#endif

L
Linus Torvalds 已提交
2413 2414 2415 2416 2417
/* 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
2418
static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
L
Linus Torvalds 已提交
2419
{
2420
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2421
	int i;
2422
	if (!(dev->features & NETIF_F_HIGHDMA)) {
2423 2424 2425
		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)))
2426
				return 1;
2427
		}
2428
	}
L
Linus Torvalds 已提交
2429

2430 2431
	if (PCI_DMA_BUS_IS_PHYS) {
		struct device *pdev = dev->dev.parent;
L
Linus Torvalds 已提交
2432

E
Eric Dumazet 已提交
2433 2434
		if (!pdev)
			return 0;
2435
		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
2436 2437
			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
			dma_addr_t addr = page_to_phys(skb_frag_page(frag));
2438 2439 2440 2441
			if (!pdev->dma_mask || addr + PAGE_SIZE - 1 > *pdev->dma_mask)
				return 1;
		}
	}
2442
#endif
L
Linus Torvalds 已提交
2443 2444 2445
	return 0;
}

2446 2447 2448 2449 2450 2451 2452 2453 2454 2455
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
2456 2457
	kfree_skb_list(skb->next);
	skb->next = NULL;
2458 2459 2460 2461 2462 2463 2464 2465 2466

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

/**
 *	dev_gso_segment - Perform emulated hardware segmentation on skb.
 *	@skb: buffer to segment
2467
 *	@features: device features as applicable to this skb
2468 2469 2470 2471
 *
 *	This function segments the given skb and stores the list of segments
 *	in skb->next.
 */
2472
static int dev_gso_segment(struct sk_buff *skb, netdev_features_t features)
2473 2474
{
	struct sk_buff *segs;
2475 2476 2477 2478 2479 2480

	segs = skb_gso_segment(skb, features);

	/* Verifying header integrity only. */
	if (!segs)
		return 0;
2481

2482
	if (IS_ERR(segs))
2483 2484 2485 2486 2487 2488 2489 2490 2491
		return PTR_ERR(segs);

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

	return 0;
}

2492
static netdev_features_t harmonize_features(struct sk_buff *skb,
2493
	netdev_features_t features)
2494
{
2495
	if (skb->ip_summed != CHECKSUM_NONE &&
2496
	    !can_checksum_protocol(features, skb_network_protocol(skb))) {
2497 2498 2499 2500 2501 2502 2503 2504
		features &= ~NETIF_F_ALL_CSUM;
	} else if (illegal_highdma(skb->dev, skb)) {
		features &= ~NETIF_F_SG;
	}

	return features;
}

2505
netdev_features_t netif_skb_features(struct sk_buff *skb)
2506 2507
{
	__be16 protocol = skb->protocol;
2508
	netdev_features_t features = skb->dev->features;
2509

2510 2511 2512
	if (skb_shinfo(skb)->gso_segs > skb->dev->gso_max_segs)
		features &= ~NETIF_F_GSO_MASK;

P
Patrick McHardy 已提交
2513
	if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD)) {
2514 2515
		struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
		protocol = veh->h_vlan_encapsulated_proto;
2516
	} else if (!vlan_tx_tag_present(skb)) {
2517
		return harmonize_features(skb, features);
2518
	}
2519

P
Patrick McHardy 已提交
2520 2521
	features &= (skb->dev->vlan_features | NETIF_F_HW_VLAN_CTAG_TX |
					       NETIF_F_HW_VLAN_STAG_TX);
2522

2523
	if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD))
2524
		features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
P
Patrick McHardy 已提交
2525 2526
				NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_CTAG_TX |
				NETIF_F_HW_VLAN_STAG_TX;
2527 2528

	return harmonize_features(skb, features);
2529
}
2530
EXPORT_SYMBOL(netif_skb_features);
2531

2532
int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
2533
			struct netdev_queue *txq, void *accel_priv)
2534
{
2535
	const struct net_device_ops *ops = dev->netdev_ops;
2536
	int rc = NETDEV_TX_OK;
2537
	unsigned int skb_len;
2538

2539
	if (likely(!skb->next)) {
2540
		netdev_features_t features;
2541

2542
		/*
L
Lucas De Marchi 已提交
2543
		 * If device doesn't need skb->dst, release it right now while
2544 2545
		 * its hot in this cpu cache
		 */
E
Eric Dumazet 已提交
2546 2547 2548
		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
			skb_dst_drop(skb);

2549 2550
		features = netif_skb_features(skb);

2551
		if (vlan_tx_tag_present(skb) &&
2552 2553 2554
		    !vlan_hw_offload_capable(features, skb->vlan_proto)) {
			skb = __vlan_put_tag(skb, skb->vlan_proto,
					     vlan_tx_tag_get(skb));
2555 2556 2557 2558 2559 2560
			if (unlikely(!skb))
				goto out;

			skb->vlan_tci = 0;
		}

2561 2562 2563 2564 2565 2566 2567
		/* 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;

2568
		if (netif_needs_gso(skb, features)) {
2569
			if (unlikely(dev_gso_segment(skb, features)))
2570 2571 2572
				goto out_kfree_skb;
			if (skb->next)
				goto gso;
2573
		} else {
2574
			if (skb_needs_linearize(skb, features) &&
2575 2576 2577 2578 2579 2580 2581 2582
			    __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) {
2583 2584 2585 2586 2587 2588
				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));
2589
				if (!(features & NETIF_F_ALL_CSUM) &&
2590 2591 2592
				     skb_checksum_help(skb))
					goto out_kfree_skb;
			}
2593 2594
		}

2595 2596 2597
		if (!list_empty(&ptype_all))
			dev_queue_xmit_nit(skb, dev);

2598
		skb_len = skb->len;
2599 2600 2601 2602 2603
		if (accel_priv)
			rc = ops->ndo_dfwd_start_xmit(skb, dev, accel_priv);
		else
			rc = ops->ndo_start_xmit(skb, dev);

2604
		trace_net_dev_xmit(skb, rc, dev, skb_len);
2605
		if (rc == NETDEV_TX_OK && txq)
E
Eric Dumazet 已提交
2606
			txq_trans_update(txq);
2607
		return rc;
2608 2609
	}

2610
gso:
2611 2612 2613 2614 2615
	do {
		struct sk_buff *nskb = skb->next;

		skb->next = nskb->next;
		nskb->next = NULL;
2616

2617 2618 2619
		if (!list_empty(&ptype_all))
			dev_queue_xmit_nit(nskb, dev);

2620
		skb_len = nskb->len;
2621 2622 2623 2624
		if (accel_priv)
			rc = ops->ndo_dfwd_start_xmit(nskb, dev, accel_priv);
		else
			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 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804
/**
 *	dev_queue_xmit - transmit a buffer
 *	@skb: buffer to transmit
 *
 *	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
 */
L
Linus Torvalds 已提交
2805 2806 2807
int dev_queue_xmit(struct sk_buff *skb)
{
	struct net_device *dev = skb->dev;
2808
	struct netdev_queue *txq;
L
Linus Torvalds 已提交
2809 2810 2811
	struct Qdisc *q;
	int rc = -ENOMEM;

2812 2813
	skb_reset_mac_header(skb);

2814 2815
	/* Disable soft irqs for various locks below. Also
	 * stops preemption for RCU.
L
Linus Torvalds 已提交
2816
	 */
2817
	rcu_read_lock_bh();
L
Linus Torvalds 已提交
2818

2819 2820
	skb_update_prio(skb);

2821
	txq = netdev_pick_tx(dev, skb);
2822
	q = rcu_dereference_bh(txq->qdisc);
2823

L
Linus Torvalds 已提交
2824
#ifdef CONFIG_NET_CLS_ACT
E
Eric Dumazet 已提交
2825
	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_EGRESS);
L
Linus Torvalds 已提交
2826
#endif
2827
	trace_net_dev_queue(skb);
L
Linus Torvalds 已提交
2828
	if (q->enqueue) {
2829
		rc = __dev_xmit_skb(skb, q, dev, txq);
2830
		goto out;
L
Linus Torvalds 已提交
2831 2832 2833 2834 2835
	}

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

H
Herbert Xu 已提交
2836 2837
	   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
2838 2839 2840 2841 2842 2843 2844 2845 2846 2847
	   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 */

2848
		if (txq->xmit_lock_owner != cpu) {
L
Linus Torvalds 已提交
2849

2850 2851 2852
			if (__this_cpu_read(xmit_recursion) > RECURSION_LIMIT)
				goto recursion_alert;

2853
			HARD_TX_LOCK(dev, txq, cpu);
L
Linus Torvalds 已提交
2854

2855
			if (!netif_xmit_stopped(txq)) {
2856
				__this_cpu_inc(xmit_recursion);
2857
				rc = dev_hard_start_xmit(skb, dev, txq, NULL);
2858
				__this_cpu_dec(xmit_recursion);
2859
				if (dev_xmit_complete(rc)) {
2860
					HARD_TX_UNLOCK(dev, txq);
L
Linus Torvalds 已提交
2861 2862 2863
					goto out;
				}
			}
2864
			HARD_TX_UNLOCK(dev, txq);
2865 2866
			net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
					     dev->name);
L
Linus Torvalds 已提交
2867 2868
		} else {
			/* Recursion is detected! It is possible,
2869 2870 2871
			 * unfortunately
			 */
recursion_alert:
2872 2873
			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
					     dev->name);
L
Linus Torvalds 已提交
2874 2875 2876 2877
		}
	}

	rc = -ENETDOWN;
2878
	rcu_read_unlock_bh();
L
Linus Torvalds 已提交
2879 2880 2881 2882

	kfree_skb(skb);
	return rc;
out:
2883
	rcu_read_unlock_bh();
L
Linus Torvalds 已提交
2884 2885
	return rc;
}
E
Eric Dumazet 已提交
2886
EXPORT_SYMBOL(dev_queue_xmit);
L
Linus Torvalds 已提交
2887 2888 2889 2890 2891 2892


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

2893
int netdev_max_backlog __read_mostly = 1000;
E
Eric Dumazet 已提交
2894 2895
EXPORT_SYMBOL(netdev_max_backlog);

E
Eric Dumazet 已提交
2896
int netdev_tstamp_prequeue __read_mostly = 1;
2897 2898
int netdev_budget __read_mostly = 300;
int weight_p __read_mostly = 64;            /* old backlog weight */
L
Linus Torvalds 已提交
2899

E
Eric Dumazet 已提交
2900 2901 2902 2903 2904 2905 2906 2907
/* 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);
}

2908 2909 2910
#ifdef CONFIG_RPS

/* One global table that all flow-based protocols share. */
E
Eric Dumazet 已提交
2911
struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
2912 2913
EXPORT_SYMBOL(rps_sock_flow_table);

2914
struct static_key rps_needed __read_mostly;
2915

2916 2917 2918 2919
static struct rps_dev_flow *
set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
	    struct rps_dev_flow *rflow, u16 next_cpu)
{
2920
	if (next_cpu != RPS_NO_CPU) {
2921 2922 2923 2924 2925 2926 2927 2928 2929
#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? */
2930 2931
		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
		    !(dev->features & NETIF_F_NTUPLE))
2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953
			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 =
2954
			per_cpu(softnet_data, next_cpu).input_queue_head;
2955 2956
	}

2957
	rflow->cpu = next_cpu;
2958 2959 2960
	return rflow;
}

2961 2962 2963 2964 2965 2966 2967 2968 2969
/*
 * 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
2970
	struct rps_map *map;
2971 2972 2973 2974 2975 2976 2977
	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);
2978 2979 2980 2981 2982
		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);
2983 2984 2985 2986 2987 2988
			goto done;
		}
		rxqueue = dev->_rx + index;
	} else
		rxqueue = dev->_rx;

E
Eric Dumazet 已提交
2989 2990
	map = rcu_dereference(rxqueue->rps_map);
	if (map) {
2991
		if (map->len == 1 &&
2992
		    !rcu_access_pointer(rxqueue->rps_flow_table)) {
2993 2994 2995 2996 2997
			tcpu = map->cpus[0];
			if (cpu_online(tcpu))
				cpu = tcpu;
			goto done;
		}
2998
	} else if (!rcu_access_pointer(rxqueue->rps_flow_table)) {
2999
		goto done;
3000
	}
3001

3002
	skb_reset_network_header(skb);
3003
	if (!skb_get_hash(skb))
3004 3005
		goto done;

T
Tom Herbert 已提交
3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031
	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 -
3032 3033
		      rflow->last_qtail)) >= 0)) {
			tcpu = next_cpu;
3034
			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
3035
		}
3036

T
Tom Herbert 已提交
3037 3038 3039 3040 3041 3042 3043
		if (tcpu != RPS_NO_CPU && cpu_online(tcpu)) {
			*rflowp = rflow;
			cpu = tcpu;
			goto done;
		}
	}

T
Tom Herbert 已提交
3044
	if (map) {
T
Tom Herbert 已提交
3045
		tcpu = map->cpus[((u64) skb->rxhash * map->len) >> 32];
T
Tom Herbert 已提交
3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056

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

done:
	return cpu;
}

3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 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
#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
3097
/* Called from hardirq (IPI) context */
E
Eric Dumazet 已提交
3098
static void rps_trigger_softirq(void *data)
T
Tom Herbert 已提交
3099
{
E
Eric Dumazet 已提交
3100 3101
	struct softnet_data *sd = data;

E
Eric Dumazet 已提交
3102
	____napi_schedule(sd, &sd->backlog);
C
Changli Gao 已提交
3103
	sd->received_rps++;
T
Tom Herbert 已提交
3104
}
E
Eric Dumazet 已提交
3105

T
Tom Herbert 已提交
3106
#endif /* CONFIG_RPS */
T
Tom Herbert 已提交
3107

E
Eric Dumazet 已提交
3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128
/*
 * 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;
}

3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147
#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) {
3148
		new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168
		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
3169 3170 3171 3172
/*
 * 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
3173 3174
static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
			      unsigned int *qtail)
T
Tom Herbert 已提交
3175
{
E
Eric Dumazet 已提交
3176
	struct softnet_data *sd;
T
Tom Herbert 已提交
3177
	unsigned long flags;
3178
	unsigned int qlen;
T
Tom Herbert 已提交
3179

E
Eric Dumazet 已提交
3180
	sd = &per_cpu(softnet_data, cpu);
T
Tom Herbert 已提交
3181 3182 3183

	local_irq_save(flags);

E
Eric Dumazet 已提交
3184
	rps_lock(sd);
3185 3186
	qlen = skb_queue_len(&sd->input_pkt_queue);
	if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) {
3187
		if (skb_queue_len(&sd->input_pkt_queue)) {
T
Tom Herbert 已提交
3188
enqueue:
E
Eric Dumazet 已提交
3189
			__skb_queue_tail(&sd->input_pkt_queue, skb);
3190
			input_queue_tail_incr_save(sd, qtail);
E
Eric Dumazet 已提交
3191
			rps_unlock(sd);
3192
			local_irq_restore(flags);
T
Tom Herbert 已提交
3193 3194 3195
			return NET_RX_SUCCESS;
		}

3196 3197 3198 3199
		/* 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
3200
			if (!rps_ipi_queued(sd))
E
Eric Dumazet 已提交
3201
				____napi_schedule(sd, &sd->backlog);
T
Tom Herbert 已提交
3202 3203 3204 3205
		}
		goto enqueue;
	}

C
Changli Gao 已提交
3206
	sd->dropped++;
E
Eric Dumazet 已提交
3207
	rps_unlock(sd);
T
Tom Herbert 已提交
3208 3209 3210

	local_irq_restore(flags);

3211
	atomic_long_inc(&skb->dev->rx_dropped);
T
Tom Herbert 已提交
3212 3213 3214
	kfree_skb(skb);
	return NET_RX_DROP;
}
L
Linus Torvalds 已提交
3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232

/**
 *	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)
{
3233
	int ret;
L
Linus Torvalds 已提交
3234 3235 3236 3237 3238

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

3239
	net_timestamp_check(netdev_tstamp_prequeue, skb);
L
Linus Torvalds 已提交
3240

3241
	trace_netif_rx(skb);
E
Eric Dumazet 已提交
3242
#ifdef CONFIG_RPS
3243
	if (static_key_false(&rps_needed)) {
T
Tom Herbert 已提交
3244
		struct rps_dev_flow voidflow, *rflow = &voidflow;
3245 3246
		int cpu;

3247
		preempt_disable();
3248
		rcu_read_lock();
T
Tom Herbert 已提交
3249 3250

		cpu = get_rps_cpu(skb->dev, skb, &rflow);
3251 3252
		if (cpu < 0)
			cpu = smp_processor_id();
T
Tom Herbert 已提交
3253 3254 3255

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

3256
		rcu_read_unlock();
3257
		preempt_enable();
3258 3259
	} else
#endif
T
Tom Herbert 已提交
3260 3261 3262 3263 3264
	{
		unsigned int qtail;
		ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
		put_cpu();
	}
3265
	return ret;
L
Linus Torvalds 已提交
3266
}
E
Eric Dumazet 已提交
3267
EXPORT_SYMBOL(netif_rx);
L
Linus Torvalds 已提交
3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298

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

	preempt_disable();
	err = netif_rx(skb);
	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;

3299
			WARN_ON(atomic_read(&skb->users));
3300 3301 3302 3303
			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
3304 3305 3306 3307 3308
			__kfree_skb(skb);
		}
	}

	if (sd->output_queue) {
3309
		struct Qdisc *head;
L
Linus Torvalds 已提交
3310 3311 3312 3313

		local_irq_disable();
		head = sd->output_queue;
		sd->output_queue = NULL;
3314
		sd->output_queue_tailp = &sd->output_queue;
L
Linus Torvalds 已提交
3315 3316 3317
		local_irq_enable();

		while (head) {
3318 3319 3320
			struct Qdisc *q = head;
			spinlock_t *root_lock;

L
Linus Torvalds 已提交
3321 3322
			head = head->next_sched;

3323
			root_lock = qdisc_lock(q);
3324
			if (spin_trylock(root_lock)) {
3325 3326 3327
				smp_mb__before_clear_bit();
				clear_bit(__QDISC_STATE_SCHED,
					  &q->state);
3328 3329
				qdisc_run(q);
				spin_unlock(root_lock);
L
Linus Torvalds 已提交
3330
			} else {
3331
				if (!test_bit(__QDISC_STATE_DEACTIVATED,
3332
					      &q->state)) {
3333
					__netif_reschedule(q);
3334 3335 3336 3337 3338
				} else {
					smp_mb__before_clear_bit();
					clear_bit(__QDISC_STATE_SCHED,
						  &q->state);
				}
L
Linus Torvalds 已提交
3339 3340 3341 3342 3343
			}
		}
	}
}

3344 3345
#if (defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)) && \
    (defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE))
3346 3347 3348
/* This hook is defined here for ATM LANE */
int (*br_fdb_test_addr_hook)(struct net_device *dev,
			     unsigned char *addr) __read_mostly;
3349
EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
3350
#endif
L
Linus Torvalds 已提交
3351 3352 3353 3354 3355 3356

#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
3357 3358
 * 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
3359 3360
 *
 */
3361
static int ing_filter(struct sk_buff *skb, struct netdev_queue *rxq)
L
Linus Torvalds 已提交
3362 3363
{
	struct net_device *dev = skb->dev;
3364
	u32 ttl = G_TC_RTTL(skb->tc_verd);
3365 3366
	int result = TC_ACT_OK;
	struct Qdisc *q;
3367

3368
	if (unlikely(MAX_RED_LOOP < ttl++)) {
3369 3370
		net_warn_ratelimited("Redir loop detected Dropping packet (%d->%d)\n",
				     skb->skb_iif, dev->ifindex);
3371 3372
		return TC_ACT_SHOT;
	}
L
Linus Torvalds 已提交
3373

3374 3375
	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
3376

3377
	q = rxq->qdisc;
3378
	if (q != &noop_qdisc) {
3379
		spin_lock(qdisc_lock(q));
3380 3381
		if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))
			result = qdisc_enqueue_root(skb, q);
3382 3383
		spin_unlock(qdisc_lock(q));
	}
3384 3385 3386

	return result;
}
3387

3388 3389 3390 3391
static inline struct sk_buff *handle_ing(struct sk_buff *skb,
					 struct packet_type **pt_prev,
					 int *ret, struct net_device *orig_dev)
{
3392 3393 3394
	struct netdev_queue *rxq = rcu_dereference(skb->dev->ingress_queue);

	if (!rxq || rxq->qdisc == &noop_qdisc)
3395
		goto out;
L
Linus Torvalds 已提交
3396

3397 3398 3399
	if (*pt_prev) {
		*ret = deliver_skb(skb, *pt_prev, orig_dev);
		*pt_prev = NULL;
L
Linus Torvalds 已提交
3400 3401
	}

3402
	switch (ing_filter(skb, rxq)) {
3403 3404 3405 3406 3407 3408 3409 3410 3411
	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
3412 3413 3414
}
#endif

3415 3416 3417 3418
/**
 *	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
3419
 *	@rx_handler_data: data pointer that is used by rx handler
3420 3421 3422 3423 3424 3425
 *
 *	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.
3426 3427
 *
 *	For a general description of rx_handler, see enum rx_handler_result.
3428 3429
 */
int netdev_rx_handler_register(struct net_device *dev,
J
Jiri Pirko 已提交
3430 3431
			       rx_handler_func_t *rx_handler,
			       void *rx_handler_data)
3432 3433 3434 3435 3436 3437
{
	ASSERT_RTNL();

	if (dev->rx_handler)
		return -EBUSY;

3438
	/* Note: rx_handler_data must be set before rx_handler */
J
Jiri Pirko 已提交
3439
	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
3440 3441 3442 3443 3444 3445 3446 3447 3448 3449
	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
3450
 *	Unregister a receive handler from a device.
3451 3452 3453 3454 3455 3456 3457
 *
 *	The caller must hold the rtnl_mutex.
 */
void netdev_rx_handler_unregister(struct net_device *dev)
{

	ASSERT_RTNL();
3458
	RCU_INIT_POINTER(dev->rx_handler, NULL);
3459 3460 3461 3462 3463
	/* 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();
3464
	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
3465 3466 3467
}
EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);

3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478
/*
 * 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
3479
	case __constant_htons(ETH_P_8021AD):
3480 3481 3482 3483 3484 3485
		return true;
	default:
		return false;
	}
}

3486
static int __netif_receive_skb_core(struct sk_buff *skb, bool pfmemalloc)
L
Linus Torvalds 已提交
3487 3488
{
	struct packet_type *ptype, *pt_prev;
3489
	rx_handler_func_t *rx_handler;
D
David S. Miller 已提交
3490
	struct net_device *orig_dev;
3491
	struct net_device *null_or_dev;
3492
	bool deliver_exact = false;
L
Linus Torvalds 已提交
3493
	int ret = NET_RX_DROP;
A
Al Viro 已提交
3494
	__be16 type;
L
Linus Torvalds 已提交
3495

3496
	net_timestamp_check(!netdev_tstamp_prequeue, skb);
3497

3498
	trace_netif_receive_skb(skb);
3499

L
Linus Torvalds 已提交
3500
	/* if we've gotten here through NAPI, check netpoll */
3501
	if (netpoll_receive_skb(skb))
3502
		goto out;
L
Linus Torvalds 已提交
3503

J
Joe Eykholt 已提交
3504
	orig_dev = skb->dev;
3505

3506
	skb_reset_network_header(skb);
3507 3508
	if (!skb_transport_header_was_set(skb))
		skb_reset_transport_header(skb);
3509
	skb_reset_mac_len(skb);
L
Linus Torvalds 已提交
3510 3511 3512 3513 3514

	pt_prev = NULL;

	rcu_read_lock();

3515
another_round:
3516
	skb->skb_iif = skb->dev->ifindex;
3517 3518 3519

	__this_cpu_inc(softnet_data.processed);

P
Patrick McHardy 已提交
3520 3521
	if (skb->protocol == cpu_to_be16(ETH_P_8021Q) ||
	    skb->protocol == cpu_to_be16(ETH_P_8021AD)) {
3522 3523
		skb = vlan_untag(skb);
		if (unlikely(!skb))
3524
			goto unlock;
3525 3526
	}

L
Linus Torvalds 已提交
3527 3528 3529 3530 3531 3532 3533
#ifdef CONFIG_NET_CLS_ACT
	if (skb->tc_verd & TC_NCLS) {
		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
		goto ncls;
	}
#endif

3534
	if (pfmemalloc)
3535 3536
		goto skip_taps;

L
Linus Torvalds 已提交
3537
	list_for_each_entry_rcu(ptype, &ptype_all, list) {
3538
		if (!ptype->dev || ptype->dev == skb->dev) {
3539
			if (pt_prev)
D
David S. Miller 已提交
3540
				ret = deliver_skb(skb, pt_prev, orig_dev);
L
Linus Torvalds 已提交
3541 3542 3543 3544
			pt_prev = ptype;
		}
	}

3545
skip_taps:
L
Linus Torvalds 已提交
3546
#ifdef CONFIG_NET_CLS_ACT
3547 3548
	skb = handle_ing(skb, &pt_prev, &ret, orig_dev);
	if (!skb)
3549
		goto unlock;
L
Linus Torvalds 已提交
3550 3551 3552
ncls:
#endif

3553
	if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
3554 3555
		goto drop;

3556 3557 3558 3559 3560
	if (vlan_tx_tag_present(skb)) {
		if (pt_prev) {
			ret = deliver_skb(skb, pt_prev, orig_dev);
			pt_prev = NULL;
		}
3561
		if (vlan_do_receive(&skb))
3562 3563
			goto another_round;
		else if (unlikely(!skb))
3564
			goto unlock;
3565 3566
	}

3567
	rx_handler = rcu_dereference(skb->dev->rx_handler);
3568 3569 3570 3571 3572
	if (rx_handler) {
		if (pt_prev) {
			ret = deliver_skb(skb, pt_prev, orig_dev);
			pt_prev = NULL;
		}
3573 3574
		switch (rx_handler(&skb)) {
		case RX_HANDLER_CONSUMED:
3575
			ret = NET_RX_SUCCESS;
3576
			goto unlock;
3577
		case RX_HANDLER_ANOTHER:
3578
			goto another_round;
3579 3580 3581 3582 3583 3584 3585
		case RX_HANDLER_EXACT:
			deliver_exact = true;
		case RX_HANDLER_PASS:
			break;
		default:
			BUG();
		}
3586
	}
L
Linus Torvalds 已提交
3587

E
Eric Dumazet 已提交
3588 3589 3590 3591 3592 3593 3594 3595 3596
	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;
	}
3597

3598
	/* deliver only exact match when indicated */
3599
	null_or_dev = deliver_exact ? skb->dev : NULL;
3600

L
Linus Torvalds 已提交
3601
	type = skb->protocol;
3602 3603
	list_for_each_entry_rcu(ptype,
			&ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
3604
		if (ptype->type == type &&
3605 3606
		    (ptype->dev == null_or_dev || ptype->dev == skb->dev ||
		     ptype->dev == orig_dev)) {
3607
			if (pt_prev)
D
David S. Miller 已提交
3608
				ret = deliver_skb(skb, pt_prev, orig_dev);
L
Linus Torvalds 已提交
3609 3610 3611 3612 3613
			pt_prev = ptype;
		}
	}

	if (pt_prev) {
3614
		if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
3615
			goto drop;
3616 3617
		else
			ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
L
Linus Torvalds 已提交
3618
	} else {
3619
drop:
3620
		atomic_long_inc(&skb->dev->rx_dropped);
L
Linus Torvalds 已提交
3621 3622 3623 3624 3625 3626 3627
		kfree_skb(skb);
		/* Jamal, now you will not able to escape explaining
		 * me how you were going to use this. :-)
		 */
		ret = NET_RX_DROP;
	}

3628
unlock:
L
Linus Torvalds 已提交
3629
	rcu_read_unlock();
3630
out:
3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655
	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
3656 3657
	return ret;
}
T
Tom Herbert 已提交
3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675

/**
 *	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)
{
3676
	net_timestamp_check(netdev_tstamp_prequeue, skb);
E
Eric Dumazet 已提交
3677

3678 3679 3680
	if (skb_defer_rx_timestamp(skb))
		return NET_RX_SUCCESS;

E
Eric Dumazet 已提交
3681
#ifdef CONFIG_RPS
3682
	if (static_key_false(&rps_needed)) {
E
Eric Dumazet 已提交
3683 3684
		struct rps_dev_flow voidflow, *rflow = &voidflow;
		int cpu, ret;
T
Tom Herbert 已提交
3685

E
Eric Dumazet 已提交
3686 3687 3688
		rcu_read_lock();

		cpu = get_rps_cpu(skb->dev, skb, &rflow);
T
Tom Herbert 已提交
3689

E
Eric Dumazet 已提交
3690 3691 3692
		if (cpu >= 0) {
			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
			rcu_read_unlock();
3693
			return ret;
E
Eric Dumazet 已提交
3694
		}
3695
		rcu_read_unlock();
T
Tom Herbert 已提交
3696
	}
3697
#endif
3698
	return __netif_receive_skb(skb);
T
Tom Herbert 已提交
3699
}
E
Eric Dumazet 已提交
3700
EXPORT_SYMBOL(netif_receive_skb);
L
Linus Torvalds 已提交
3701

E
Eric Dumazet 已提交
3702 3703 3704
/* Network device is going away, flush any packets still pending
 * Called with irqs disabled.
 */
3705
static void flush_backlog(void *arg)
3706
{
3707
	struct net_device *dev = arg;
E
Eric Dumazet 已提交
3708
	struct softnet_data *sd = &__get_cpu_var(softnet_data);
3709 3710
	struct sk_buff *skb, *tmp;

E
Eric Dumazet 已提交
3711
	rps_lock(sd);
3712
	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
3713
		if (skb->dev == dev) {
E
Eric Dumazet 已提交
3714
			__skb_unlink(skb, &sd->input_pkt_queue);
3715
			kfree_skb(skb);
3716
			input_queue_head_incr(sd);
3717
		}
3718
	}
E
Eric Dumazet 已提交
3719
	rps_unlock(sd);
3720 3721 3722 3723 3724

	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
		if (skb->dev == dev) {
			__skb_unlink(skb, &sd->process_queue);
			kfree_skb(skb);
3725
			input_queue_head_incr(sd);
3726 3727
		}
	}
3728 3729
}

3730 3731
static int napi_gro_complete(struct sk_buff *skb)
{
3732
	struct packet_offload *ptype;
3733
	__be16 type = skb->protocol;
3734
	struct list_head *head = &offload_base;
3735 3736
	int err = -ENOENT;

3737 3738
	BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));

3739 3740
	if (NAPI_GRO_CB(skb)->count == 1) {
		skb_shinfo(skb)->gso_size = 0;
3741
		goto out;
3742
	}
3743 3744 3745

	rcu_read_lock();
	list_for_each_entry_rcu(ptype, head, list) {
3746
		if (ptype->type != type || !ptype->callbacks.gro_complete)
3747 3748
			continue;

3749
		err = ptype->callbacks.gro_complete(skb, 0);
3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763
		break;
	}
	rcu_read_unlock();

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

out:
	return netif_receive_skb(skb);
}

3764 3765 3766 3767 3768
/* 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)
3769
{
3770
	struct sk_buff *skb, *prev = NULL;
3771

3772 3773 3774 3775 3776 3777 3778
	/* 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) {
3779
		skb->next = NULL;
3780 3781 3782 3783 3784

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

		prev = skb->prev;
3785
		napi_gro_complete(skb);
3786
		napi->gro_count--;
3787 3788 3789 3790
	}

	napi->gro_list = NULL;
}
E
Eric Dumazet 已提交
3791
EXPORT_SYMBOL(napi_gro_flush);
3792

E
Eric Dumazet 已提交
3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814
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;

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

		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;
		NAPI_GRO_CB(p)->flush = 0;
	}
}

3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831
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
3832
static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3833 3834
{
	struct sk_buff **pp = NULL;
3835
	struct packet_offload *ptype;
3836
	__be16 type = skb->protocol;
3837
	struct list_head *head = &offload_base;
H
Herbert Xu 已提交
3838
	int same_flow;
3839
	enum gro_result ret;
3840

3841
	if (!(skb->dev->features & NETIF_F_GRO) || netpoll_rx_on(skb))
3842 3843
		goto normal;

3844
	if (skb_is_gso(skb) || skb_has_frag_list(skb))
3845 3846
		goto normal;

3847
	skb_gro_reset_offset(skb);
E
Eric Dumazet 已提交
3848
	gro_list_prepare(napi, skb);
3849
	NAPI_GRO_CB(skb)->csum = skb->csum; /* Needed for CHECKSUM_COMPLETE */
E
Eric Dumazet 已提交
3850

3851 3852
	rcu_read_lock();
	list_for_each_entry_rcu(ptype, head, list) {
3853
		if (ptype->type != type || !ptype->callbacks.gro_receive)
3854 3855
			continue;

3856
		skb_set_network_header(skb, skb_gro_offset(skb));
3857
		skb_reset_mac_len(skb);
3858 3859
		NAPI_GRO_CB(skb)->same_flow = 0;
		NAPI_GRO_CB(skb)->flush = 0;
H
Herbert Xu 已提交
3860
		NAPI_GRO_CB(skb)->free = 0;
3861

3862
		pp = ptype->callbacks.gro_receive(&napi->gro_list, skb);
3863 3864 3865 3866 3867 3868 3869
		break;
	}
	rcu_read_unlock();

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

H
Herbert Xu 已提交
3870
	same_flow = NAPI_GRO_CB(skb)->same_flow;
3871
	ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
H
Herbert Xu 已提交
3872

3873 3874 3875 3876 3877 3878
	if (pp) {
		struct sk_buff *nskb = *pp;

		*pp = nskb->next;
		nskb->next = NULL;
		napi_gro_complete(nskb);
3879
		napi->gro_count--;
3880 3881
	}

H
Herbert Xu 已提交
3882
	if (same_flow)
3883 3884
		goto ok;

3885
	if (NAPI_GRO_CB(skb)->flush || napi->gro_count >= MAX_GRO_SKBS)
3886 3887
		goto normal;

3888
	napi->gro_count++;
3889
	NAPI_GRO_CB(skb)->count = 1;
3890
	NAPI_GRO_CB(skb)->age = jiffies;
3891
	skb_shinfo(skb)->gso_size = skb_gro_len(skb);
3892 3893
	skb->next = napi->gro_list;
	napi->gro_list = skb;
3894
	ret = GRO_HELD;
3895

3896
pull:
H
Herbert Xu 已提交
3897 3898 3899 3900 3901 3902 3903 3904 3905 3906 3907
	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
3908
		skb_frag_size_sub(&skb_shinfo(skb)->frags[0], grow);
H
Herbert Xu 已提交
3909

E
Eric Dumazet 已提交
3910
		if (unlikely(!skb_frag_size(&skb_shinfo(skb)->frags[0]))) {
3911
			skb_frag_unref(skb, 0);
H
Herbert Xu 已提交
3912 3913
			memmove(skb_shinfo(skb)->frags,
				skb_shinfo(skb)->frags + 1,
3914
				--skb_shinfo(skb)->nr_frags * sizeof(skb_frag_t));
H
Herbert Xu 已提交
3915
		}
3916 3917
	}

3918
ok:
3919
	return ret;
3920 3921

normal:
3922 3923
	ret = GRO_NORMAL;
	goto pull;
H
Herbert Xu 已提交
3924
}
3925

3926 3927 3928 3929 3930 3931 3932 3933 3934 3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950
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
3951

R
Rami Rosen 已提交
3952
static gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
H
Herbert Xu 已提交
3953
{
3954 3955
	switch (ret) {
	case GRO_NORMAL:
3956 3957 3958
		if (netif_receive_skb(skb))
			ret = GRO_DROP;
		break;
H
Herbert Xu 已提交
3959

3960
	case GRO_DROP:
H
Herbert Xu 已提交
3961 3962
		kfree_skb(skb);
		break;
3963

3964
	case GRO_MERGED_FREE:
3965 3966 3967 3968
		if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
			kmem_cache_free(skbuff_head_cache, skb);
		else
			__kfree_skb(skb);
3969 3970
		break;

3971 3972 3973
	case GRO_HELD:
	case GRO_MERGED:
		break;
H
Herbert Xu 已提交
3974 3975
	}

3976
	return ret;
3977 3978
}

3979
gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3980
{
E
Eric Dumazet 已提交
3981
	return napi_skb_finish(dev_gro_receive(napi, skb), skb);
3982 3983 3984
}
EXPORT_SYMBOL(napi_gro_receive);

S
stephen hemminger 已提交
3985
static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
3986 3987
{
	__skb_pull(skb, skb_headlen(skb));
3988 3989
	/* restore the reserve we had after netdev_alloc_skb_ip_align() */
	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
3990
	skb->vlan_tci = 0;
H
Herbert Xu 已提交
3991
	skb->dev = napi->dev;
A
Andy Gospodarek 已提交
3992
	skb->skb_iif = 0;
3993 3994 3995 3996

	napi->skb = skb;
}

3997
struct sk_buff *napi_get_frags(struct napi_struct *napi)
H
Herbert Xu 已提交
3998 3999 4000 4001
{
	struct sk_buff *skb = napi->skb;

	if (!skb) {
4002
		skb = netdev_alloc_skb_ip_align(napi->dev, GRO_MAX_HEAD);
E
Eric Dumazet 已提交
4003
		napi->skb = skb;
4004
	}
4005 4006
	return skb;
}
4007
EXPORT_SYMBOL(napi_get_frags);
4008

R
Rami Rosen 已提交
4009
static gro_result_t napi_frags_finish(struct napi_struct *napi, struct sk_buff *skb,
4010
			       gro_result_t ret)
4011
{
4012 4013
	switch (ret) {
	case GRO_NORMAL:
4014
		if (netif_receive_skb(skb))
4015
			ret = GRO_DROP;
4016
		break;
H
Herbert Xu 已提交
4017

4018 4019 4020 4021
	case GRO_DROP:
	case GRO_MERGED_FREE:
		napi_reuse_skb(napi, skb);
		break;
4022

4023
	case GRO_HELD:
4024 4025
	case GRO_MERGED:
		break;
4026
	}
H
Herbert Xu 已提交
4027

4028
	return ret;
H
Herbert Xu 已提交
4029
}
4030

E
Eric Dumazet 已提交
4031
static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
4032 4033 4034 4035 4036
{
	struct sk_buff *skb = napi->skb;

	napi->skb = NULL;

4037 4038 4039
	if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr)))) {
		napi_reuse_skb(napi, skb);
		return NULL;
4040
	}
4041
	skb->protocol = eth_type_trans(skb, skb->dev);
4042 4043 4044 4045

	return skb;
}

4046
gro_result_t napi_gro_frags(struct napi_struct *napi)
4047
{
4048
	struct sk_buff *skb = napi_frags_skb(napi);
4049 4050

	if (!skb)
4051
		return GRO_DROP;
4052

E
Eric Dumazet 已提交
4053
	return napi_frags_finish(napi, skb, dev_gro_receive(napi, skb));
4054
}
H
Herbert Xu 已提交
4055 4056
EXPORT_SYMBOL(napi_gro_frags);

4057
/*
4058
 * net_rps_action_and_irq_enable sends any pending IPI's for rps.
4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080 4081 4082 4083 4084
 * 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();
}

4085
static int process_backlog(struct napi_struct *napi, int quota)
L
Linus Torvalds 已提交
4086 4087
{
	int work = 0;
E
Eric Dumazet 已提交
4088
	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
L
Linus Torvalds 已提交
4089

4090 4091 4092 4093 4094 4095 4096 4097 4098
#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
4099
	napi->weight = weight_p;
4100 4101
	local_irq_disable();
	while (work < quota) {
L
Linus Torvalds 已提交
4102
		struct sk_buff *skb;
4103 4104 4105 4106 4107 4108
		unsigned int qlen;

		while ((skb = __skb_dequeue(&sd->process_queue))) {
			local_irq_enable();
			__netif_receive_skb(skb);
			local_irq_disable();
4109 4110 4111 4112 4113
			input_queue_head_incr(sd);
			if (++work >= quota) {
				local_irq_enable();
				return work;
			}
4114
		}
L
Linus Torvalds 已提交
4115

E
Eric Dumazet 已提交
4116
		rps_lock(sd);
4117
		qlen = skb_queue_len(&sd->input_pkt_queue);
4118
		if (qlen)
4119 4120
			skb_queue_splice_tail_init(&sd->input_pkt_queue,
						   &sd->process_queue);
4121

4122
		if (qlen < quota - work) {
E
Eric Dumazet 已提交
4123 4124 4125 4126 4127 4128 4129 4130 4131 4132
			/*
			 * 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;

4133
			quota = work + qlen;
4134
		}
E
Eric Dumazet 已提交
4135
		rps_unlock(sd);
4136 4137
	}
	local_irq_enable();
L
Linus Torvalds 已提交
4138

4139 4140
	return work;
}
L
Linus Torvalds 已提交
4141

4142 4143
/**
 * __napi_schedule - schedule for receive
4144
 * @n: entry to schedule
4145 4146 4147
 *
 * The entry's receive function will be scheduled to run
 */
H
Harvey Harrison 已提交
4148
void __napi_schedule(struct napi_struct *n)
4149 4150
{
	unsigned long flags;
L
Linus Torvalds 已提交
4151

4152
	local_irq_save(flags);
E
Eric Dumazet 已提交
4153
	____napi_schedule(&__get_cpu_var(softnet_data), n);
4154
	local_irq_restore(flags);
L
Linus Torvalds 已提交
4155
}
4156 4157
EXPORT_SYMBOL(__napi_schedule);

4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176 4177 4178 4179
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;

4180
	napi_gro_flush(n, false);
4181 4182 4183 4184 4185 4186
	local_irq_save(flags);
	__napi_complete(n);
	local_irq_restore(flags);
}
EXPORT_SYMBOL(napi_complete);

E
Eliezer Tamir 已提交
4187 4188 4189 4190 4191 4192 4193 4194 4195 4196 4197 4198 4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238
/* 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);

4239 4240 4241 4242
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);
4243
	napi->gro_count = 0;
4244
	napi->gro_list = NULL;
H
Herbert Xu 已提交
4245
	napi->skb = NULL;
4246
	napi->poll = poll;
E
Eric Dumazet 已提交
4247 4248 4249
	if (weight > NAPI_POLL_WEIGHT)
		pr_err_once("netif_napi_add() called with weight %d on device %s\n",
			    weight, dev->name);
4250 4251 4252
	napi->weight = weight;
	list_add(&napi->dev_list, &dev->napi_list);
	napi->dev = dev;
H
Herbert Xu 已提交
4253
#ifdef CONFIG_NETPOLL
4254 4255 4256 4257 4258 4259 4260 4261 4262
	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)
{
4263
	list_del_init(&napi->dev_list);
4264
	napi_free_frags(napi);
4265

E
Eric Dumazet 已提交
4266
	kfree_skb_list(napi->gro_list);
4267
	napi->gro_list = NULL;
4268
	napi->gro_count = 0;
4269 4270 4271
}
EXPORT_SYMBOL(netif_napi_del);

L
Linus Torvalds 已提交
4272 4273
static void net_rx_action(struct softirq_action *h)
{
4274
	struct softnet_data *sd = &__get_cpu_var(softnet_data);
4275
	unsigned long time_limit = jiffies + 2;
4276
	int budget = netdev_budget;
4277 4278
	void *have;

L
Linus Torvalds 已提交
4279 4280
	local_irq_disable();

4281
	while (!list_empty(&sd->poll_list)) {
4282 4283
		struct napi_struct *n;
		int work, weight;
L
Linus Torvalds 已提交
4284

4285
		/* If softirq window is exhuasted then punt.
4286 4287
		 * Allow this to run for 2 jiffies since which will allow
		 * an average latency of 1.5/HZ.
4288
		 */
4289
		if (unlikely(budget <= 0 || time_after_eq(jiffies, time_limit)))
L
Linus Torvalds 已提交
4290 4291 4292 4293
			goto softnet_break;

		local_irq_enable();

4294 4295 4296 4297 4298
		/* 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.
		 */
4299
		n = list_first_entry(&sd->poll_list, struct napi_struct, poll_list);
L
Linus Torvalds 已提交
4300

4301 4302 4303 4304
		have = netpoll_poll_lock(n);

		weight = n->weight;

4305 4306 4307 4308
		/* 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
4309
		 * accidentally calling ->poll() when NAPI is not scheduled.
4310 4311
		 */
		work = 0;
4312
		if (test_bit(NAPI_STATE_SCHED, &n->state)) {
4313
			work = n->poll(n, weight);
4314 4315
			trace_napi_poll(n);
		}
4316 4317 4318 4319 4320 4321 4322 4323 4324 4325 4326 4327

		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.
		 */
4328
		if (unlikely(work == weight)) {
4329 4330 4331 4332
			if (unlikely(napi_disable_pending(n))) {
				local_irq_enable();
				napi_complete(n);
				local_irq_disable();
4333 4334 4335 4336 4337 4338 4339 4340 4341
			} 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();
				}
4342
				list_move_tail(&n->poll_list, &sd->poll_list);
4343
			}
4344
		}
4345 4346

		netpoll_poll_unlock(have);
L
Linus Torvalds 已提交
4347 4348
	}
out:
4349
	net_rps_action_and_irq_enable(sd);
T
Tom Herbert 已提交
4350

4351 4352 4353 4354 4355
#ifdef CONFIG_NET_DMA
	/*
	 * There may not be any more sk_buffs coming right now, so push
	 * any pending DMA copies to hardware
	 */
4356
	dma_issue_pending_all();
4357
#endif
4358

L
Linus Torvalds 已提交
4359 4360 4361
	return;

softnet_break:
C
Changli Gao 已提交
4362
	sd->time_squeeze++;
L
Linus Torvalds 已提交
4363 4364 4365 4366
	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
	goto out;
}

4367
struct netdev_adjacent {
J
Jiri Pirko 已提交
4368
	struct net_device *dev;
4369 4370

	/* upper master flag, there can only be one master device per list */
J
Jiri Pirko 已提交
4371
	bool master;
4372 4373 4374 4375

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

4376 4377 4378
	/* private field for the users */
	void *private;

J
Jiri Pirko 已提交
4379 4380 4381 4382
	struct list_head list;
	struct rcu_head rcu;
};

4383 4384
static struct netdev_adjacent *__netdev_find_adj(struct net_device *dev,
						 struct net_device *adj_dev,
4385
						 struct list_head *adj_list)
J
Jiri Pirko 已提交
4386
{
4387 4388
	struct netdev_adjacent *adj;

4389
	list_for_each_entry(adj, adj_list, list) {
4390 4391
		if (adj->dev == adj_dev)
			return adj;
J
Jiri Pirko 已提交
4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404 4405 4406 4407 4408 4409
	}
	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();

4410
	return __netdev_find_adj(dev, upper_dev, &dev->all_adj_list.upper);
J
Jiri Pirko 已提交
4411 4412 4413 4414 4415 4416 4417 4418 4419 4420
}
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
4421
static bool netdev_has_any_upper_dev(struct net_device *dev)
J
Jiri Pirko 已提交
4422 4423 4424
{
	ASSERT_RTNL();

4425
	return !list_empty(&dev->all_adj_list.upper);
J
Jiri Pirko 已提交
4426 4427 4428 4429 4430 4431 4432 4433 4434 4435 4436
}

/**
 * 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)
{
4437
	struct netdev_adjacent *upper;
J
Jiri Pirko 已提交
4438 4439 4440

	ASSERT_RTNL();

4441
	if (list_empty(&dev->adj_list.upper))
J
Jiri Pirko 已提交
4442 4443
		return NULL;

4444
	upper = list_first_entry(&dev->adj_list.upper,
4445
				 struct netdev_adjacent, list);
J
Jiri Pirko 已提交
4446 4447 4448 4449 4450 4451
	if (likely(upper->master))
		return upper->dev;
	return NULL;
}
EXPORT_SYMBOL(netdev_master_upper_dev_get);

4452 4453 4454 4455 4456 4457 4458 4459 4460 4461
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);

4462 4463
/**
 * netdev_all_upper_get_next_dev_rcu - Get the next dev from upper list
4464 4465 4466 4467 4468 4469
 * @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.
 */
4470 4471
struct net_device *netdev_all_upper_get_next_dev_rcu(struct net_device *dev,
						     struct list_head **iter)
4472 4473 4474
{
	struct netdev_adjacent *upper;

4475
	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
4476 4477 4478

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

4479
	if (&upper->list == &dev->all_adj_list.upper)
4480 4481 4482 4483 4484 4485
		return NULL;

	*iter = &upper->list;

	return upper->dev;
}
4486
EXPORT_SYMBOL(netdev_all_upper_get_next_dev_rcu);
4487

4488 4489 4490 4491 4492 4493 4494 4495 4496 4497 4498 4499 4500 4501 4502 4503 4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515 4516 4517 4518 4519 4520 4521 4522 4523 4524 4525 4526 4527 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537 4538 4539 4540 4541 4542 4543 4544
/**
 * 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);

4545 4546 4547 4548 4549 4550 4551 4552 4553 4554 4555 4556 4557 4558 4559 4560 4561 4562 4563 4564 4565
/**
 * 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
4566 4567 4568 4569 4570 4571 4572 4573 4574
/**
 * 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)
{
4575
	struct netdev_adjacent *upper;
J
Jiri Pirko 已提交
4576

4577
	upper = list_first_or_null_rcu(&dev->adj_list.upper,
4578
				       struct netdev_adjacent, list);
J
Jiri Pirko 已提交
4579 4580 4581 4582 4583 4584
	if (upper && likely(upper->master))
		return upper->dev;
	return NULL;
}
EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);

4585 4586
static int __netdev_adjacent_dev_insert(struct net_device *dev,
					struct net_device *adj_dev,
4587
					struct list_head *dev_list,
4588
					void *private, bool master)
4589 4590
{
	struct netdev_adjacent *adj;
4591
	char linkname[IFNAMSIZ+7];
4592
	int ret;
4593

4594
	adj = __netdev_find_adj(dev, adj_dev, dev_list);
4595 4596 4597 4598 4599 4600 4601 4602 4603 4604 4605 4606 4607

	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;
4608
	adj->private = private;
4609
	dev_hold(adj_dev);
4610 4611 4612

	pr_debug("dev_hold for %s, because of link added from %s to %s\n",
		 adj_dev->name, dev->name, adj_dev->name);
4613

4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627
	if (dev_list == &dev->adj_list.lower) {
		sprintf(linkname, "lower_%s", adj_dev->name);
		ret = sysfs_create_link(&(dev->dev.kobj),
					&(adj_dev->dev.kobj), linkname);
		if (ret)
			goto free_adj;
	} else if (dev_list == &dev->adj_list.upper) {
		sprintf(linkname, "upper_%s", adj_dev->name);
		ret = sysfs_create_link(&(dev->dev.kobj),
					&(adj_dev->dev.kobj), linkname);
		if (ret)
			goto free_adj;
	}

4628
	/* Ensure that master link is always the first item in list. */
4629 4630 4631 4632
	if (master) {
		ret = sysfs_create_link(&(dev->dev.kobj),
					&(adj_dev->dev.kobj), "master");
		if (ret)
4633
			goto remove_symlinks;
4634

4635
		list_add_rcu(&adj->list, dev_list);
4636
	} else {
4637
		list_add_tail_rcu(&adj->list, dev_list);
4638
	}
4639 4640

	return 0;
4641

4642 4643 4644 4645 4646 4647 4648 4649 4650
remove_symlinks:
	if (dev_list == &dev->adj_list.lower) {
		sprintf(linkname, "lower_%s", adj_dev->name);
		sysfs_remove_link(&(dev->dev.kobj), linkname);
	} else if (dev_list == &dev->adj_list.upper) {
		sprintf(linkname, "upper_%s", adj_dev->name);
		sysfs_remove_link(&(dev->dev.kobj), linkname);
	}

4651 4652
free_adj:
	kfree(adj);
4653
	dev_put(adj_dev);
4654 4655

	return ret;
4656 4657
}

S
stephen hemminger 已提交
4658 4659 4660
static void __netdev_adjacent_dev_remove(struct net_device *dev,
					 struct net_device *adj_dev,
					 struct list_head *dev_list)
4661 4662
{
	struct netdev_adjacent *adj;
4663
	char linkname[IFNAMSIZ+7];
4664

4665
	adj = __netdev_find_adj(dev, adj_dev, dev_list);
4666

4667 4668 4669
	if (!adj) {
		pr_err("tried to remove device %s from %s\n",
		       dev->name, adj_dev->name);
4670
		BUG();
4671
	}
4672 4673

	if (adj->ref_nr > 1) {
4674 4675
		pr_debug("%s to %s ref_nr-- = %d\n", dev->name, adj_dev->name,
			 adj->ref_nr-1);
4676 4677 4678 4679
		adj->ref_nr--;
		return;
	}

4680 4681 4682
	if (adj->master)
		sysfs_remove_link(&(dev->dev.kobj), "master");

4683 4684 4685 4686 4687 4688 4689 4690
	if (dev_list == &dev->adj_list.lower) {
		sprintf(linkname, "lower_%s", adj_dev->name);
		sysfs_remove_link(&(dev->dev.kobj), linkname);
	} else if (dev_list == &dev->adj_list.upper) {
		sprintf(linkname, "upper_%s", adj_dev->name);
		sysfs_remove_link(&(dev->dev.kobj), linkname);
	}

4691
	list_del_rcu(&adj->list);
4692 4693
	pr_debug("dev_put for %s, because link removed from %s to %s\n",
		 adj_dev->name, dev->name, adj_dev->name);
4694 4695 4696 4697
	dev_put(adj_dev);
	kfree_rcu(adj, rcu);
}

S
stephen hemminger 已提交
4698 4699 4700 4701 4702
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)
4703 4704 4705
{
	int ret;

4706 4707
	ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list, private,
					   master);
4708 4709 4710
	if (ret)
		return ret;

4711 4712
	ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list, private,
					   false);
4713
	if (ret) {
4714
		__netdev_adjacent_dev_remove(dev, upper_dev, up_list);
4715 4716 4717 4718 4719 4720
		return ret;
	}

	return 0;
}

S
stephen hemminger 已提交
4721 4722
static int __netdev_adjacent_dev_link(struct net_device *dev,
				      struct net_device *upper_dev)
4723
{
4724 4725 4726
	return __netdev_adjacent_dev_link_lists(dev, upper_dev,
						&dev->all_adj_list.upper,
						&upper_dev->all_adj_list.lower,
4727
						NULL, false);
4728 4729
}

S
stephen hemminger 已提交
4730 4731 4732 4733
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)
4734
{
4735 4736
	__netdev_adjacent_dev_remove(dev, upper_dev, up_list);
	__netdev_adjacent_dev_remove(upper_dev, dev, down_list);
4737 4738
}

S
stephen hemminger 已提交
4739 4740
static void __netdev_adjacent_dev_unlink(struct net_device *dev,
					 struct net_device *upper_dev)
4741
{
4742 4743 4744 4745 4746
	__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
4747 4748 4749
static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
						struct net_device *upper_dev,
						void *private, bool master)
4750 4751 4752 4753 4754 4755 4756 4757 4758
{
	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,
4759
					       private, master);
4760 4761 4762 4763 4764 4765
	if (ret) {
		__netdev_adjacent_dev_unlink(dev, upper_dev);
		return ret;
	}

	return 0;
4766 4767
}

S
stephen hemminger 已提交
4768 4769
static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
						   struct net_device *upper_dev)
4770 4771 4772 4773 4774 4775
{
	__netdev_adjacent_dev_unlink(dev, upper_dev);
	__netdev_adjacent_dev_unlink_lists(dev, upper_dev,
					   &dev->adj_list.upper,
					   &upper_dev->adj_list.lower);
}
4776

J
Jiri Pirko 已提交
4777
static int __netdev_upper_dev_link(struct net_device *dev,
4778 4779
				   struct net_device *upper_dev, bool master,
				   void *private)
J
Jiri Pirko 已提交
4780
{
4781 4782
	struct netdev_adjacent *i, *j, *to_i, *to_j;
	int ret = 0;
J
Jiri Pirko 已提交
4783 4784 4785 4786 4787 4788 4789

	ASSERT_RTNL();

	if (dev == upper_dev)
		return -EBUSY;

	/* To prevent loops, check if dev is not upper device to upper_dev. */
4790
	if (__netdev_find_adj(upper_dev, dev, &upper_dev->all_adj_list.upper))
J
Jiri Pirko 已提交
4791 4792
		return -EBUSY;

4793
	if (__netdev_find_adj(dev, upper_dev, &dev->all_adj_list.upper))
J
Jiri Pirko 已提交
4794 4795 4796 4797 4798
		return -EEXIST;

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

4799 4800
	ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, private,
						   master);
4801 4802
	if (ret)
		return ret;
J
Jiri Pirko 已提交
4803

4804
	/* Now that we linked these devs, make all the upper_dev's
4805
	 * all_adj_list.upper visible to every dev's all_adj_list.lower an
4806 4807 4808
	 * versa, and don't forget the devices itself. All of these
	 * links are non-neighbours.
	 */
4809 4810 4811 4812
	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);
4813 4814 4815 4816 4817 4818 4819
			ret = __netdev_adjacent_dev_link(i->dev, j->dev);
			if (ret)
				goto rollback_mesh;
		}
	}

	/* add dev to every upper_dev's upper device */
4820 4821 4822
	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);
4823 4824 4825 4826 4827 4828
		ret = __netdev_adjacent_dev_link(dev, i->dev);
		if (ret)
			goto rollback_upper_mesh;
	}

	/* add upper_dev to every dev's lower device */
4829 4830 4831
	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);
4832 4833 4834 4835
		ret = __netdev_adjacent_dev_link(i->dev, upper_dev);
		if (ret)
			goto rollback_lower_mesh;
	}
J
Jiri Pirko 已提交
4836

4837
	call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev);
J
Jiri Pirko 已提交
4838
	return 0;
4839 4840 4841

rollback_lower_mesh:
	to_i = i;
4842
	list_for_each_entry(i, &dev->all_adj_list.lower, list) {
4843 4844 4845 4846 4847 4848 4849 4850 4851
		if (i == to_i)
			break;
		__netdev_adjacent_dev_unlink(i->dev, upper_dev);
	}

	i = NULL;

rollback_upper_mesh:
	to_i = i;
4852
	list_for_each_entry(i, &upper_dev->all_adj_list.upper, list) {
4853 4854 4855 4856 4857 4858 4859 4860 4861 4862
		if (i == to_i)
			break;
		__netdev_adjacent_dev_unlink(dev, i->dev);
	}

	i = j = NULL;

rollback_mesh:
	to_i = i;
	to_j = j;
4863 4864
	list_for_each_entry(i, &dev->all_adj_list.lower, list) {
		list_for_each_entry(j, &upper_dev->all_adj_list.upper, list) {
4865 4866 4867 4868 4869 4870 4871 4872
			if (i == to_i && j == to_j)
				break;
			__netdev_adjacent_dev_unlink(i->dev, j->dev);
		}
		if (i == to_i)
			break;
	}

4873
	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
4874 4875

	return ret;
J
Jiri Pirko 已提交
4876 4877 4878 4879 4880 4881 4882 4883 4884 4885 4886 4887 4888 4889 4890
}

/**
 * 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)
{
4891
	return __netdev_upper_dev_link(dev, upper_dev, false, NULL);
J
Jiri Pirko 已提交
4892 4893 4894 4895 4896 4897 4898 4899 4900 4901 4902 4903 4904 4905 4906 4907 4908
}
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)
{
4909
	return __netdev_upper_dev_link(dev, upper_dev, true, NULL);
J
Jiri Pirko 已提交
4910 4911 4912
}
EXPORT_SYMBOL(netdev_master_upper_dev_link);

4913 4914 4915 4916 4917 4918 4919 4920
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
4921 4922 4923 4924 4925 4926 4927 4928 4929 4930 4931
/**
 * 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)
{
4932
	struct netdev_adjacent *i, *j;
J
Jiri Pirko 已提交
4933 4934
	ASSERT_RTNL();

4935
	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
4936 4937 4938 4939 4940

	/* 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.
	 */
4941 4942
	list_for_each_entry(i, &dev->all_adj_list.lower, list)
		list_for_each_entry(j, &upper_dev->all_adj_list.upper, list)
4943 4944 4945 4946 4947
			__netdev_adjacent_dev_unlink(i->dev, j->dev);

	/* remove also the devices itself from lower/upper device
	 * list
	 */
4948
	list_for_each_entry(i, &dev->all_adj_list.lower, list)
4949 4950
		__netdev_adjacent_dev_unlink(i->dev, upper_dev);

4951
	list_for_each_entry(i, &upper_dev->all_adj_list.upper, list)
4952 4953
		__netdev_adjacent_dev_unlink(dev, i->dev);

4954
	call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev);
J
Jiri Pirko 已提交
4955 4956 4957
}
EXPORT_SYMBOL(netdev_upper_dev_unlink);

4958 4959 4960 4961 4962 4963 4964 4965 4966 4967 4968 4969 4970 4971 4972
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);

4973 4974
static void dev_change_rx_flags(struct net_device *dev, int flags)
{
4975 4976
	const struct net_device_ops *ops = dev->netdev_ops;

4977
	if (ops->ndo_change_rx_flags)
4978
		ops->ndo_change_rx_flags(dev, flags);
4979 4980
}

4981
static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
L
Linus Torvalds 已提交
4982
{
4983
	unsigned int old_flags = dev->flags;
4984 4985
	kuid_t uid;
	kgid_t gid;
L
Linus Torvalds 已提交
4986

4987 4988
	ASSERT_RTNL();

4989 4990 4991 4992 4993 4994 4995 4996 4997 4998 4999
	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;
5000 5001
			pr_warn("%s: promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n",
				dev->name);
5002 5003 5004
			return -EOVERFLOW;
		}
	}
5005
	if (dev->flags != old_flags) {
5006 5007 5008
		pr_info("device %s %s promiscuous mode\n",
			dev->name,
			dev->flags & IFF_PROMISC ? "entered" : "left");
5009 5010
		if (audit_enabled) {
			current_uid_gid(&uid, &gid);
5011 5012 5013 5014 5015
			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),
5016
				from_kuid(&init_user_ns, audit_get_loginuid(current)),
5017 5018
				from_kuid(&init_user_ns, uid),
				from_kgid(&init_user_ns, gid),
5019
				audit_get_sessionid(current));
5020
		}
5021

5022
		dev_change_rx_flags(dev, IFF_PROMISC);
L
Linus Torvalds 已提交
5023
	}
5024 5025
	if (notify)
		__dev_notify_flags(dev, old_flags, IFF_PROMISC);
5026
	return 0;
L
Linus Torvalds 已提交
5027 5028
}

5029 5030 5031 5032 5033 5034 5035 5036 5037
/**
 *	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.
5038
 *	Return 0 if successful or a negative errno code on error.
5039
 */
5040
int dev_set_promiscuity(struct net_device *dev, int inc)
5041
{
5042
	unsigned int old_flags = dev->flags;
5043
	int err;
5044

5045
	err = __dev_set_promiscuity(dev, inc, true);
5046
	if (err < 0)
5047
		return err;
5048 5049
	if (dev->flags != old_flags)
		dev_set_rx_mode(dev);
5050
	return err;
5051
}
E
Eric Dumazet 已提交
5052
EXPORT_SYMBOL(dev_set_promiscuity);
5053

5054
static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
L
Linus Torvalds 已提交
5055
{
5056
	unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
L
Linus Torvalds 已提交
5057

5058 5059
	ASSERT_RTNL();

L
Linus Torvalds 已提交
5060
	dev->flags |= IFF_ALLMULTI;
5061 5062 5063 5064 5065 5066 5067 5068 5069 5070
	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;
5071 5072
			pr_warn("%s: allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n",
				dev->name);
5073 5074 5075
			return -EOVERFLOW;
		}
	}
5076
	if (dev->flags ^ old_flags) {
5077
		dev_change_rx_flags(dev, IFF_ALLMULTI);
5078
		dev_set_rx_mode(dev);
5079 5080 5081
		if (notify)
			__dev_notify_flags(dev, old_flags,
					   dev->gflags ^ old_gflags);
5082
	}
5083
	return 0;
5084
}
5085 5086 5087 5088 5089 5090 5091 5092 5093 5094 5095 5096 5097 5098 5099 5100 5101 5102

/**
 *	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
5103
EXPORT_SYMBOL(dev_set_allmulti);
5104 5105 5106 5107

/*
 *	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
5108
 *	filtering it is put in promiscuous mode while unicast addresses
5109 5110 5111 5112
 *	are present.
 */
void __dev_set_rx_mode(struct net_device *dev)
{
5113 5114
	const struct net_device_ops *ops = dev->netdev_ops;

5115 5116 5117 5118 5119
	/* dev_open will call this function so the list will stay sane. */
	if (!(dev->flags&IFF_UP))
		return;

	if (!netif_device_present(dev))
5120
		return;
5121

5122
	if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
5123 5124 5125
		/* Unicast addresses changes may only happen under the rtnl,
		 * therefore calling __dev_set_promiscuity here is safe.
		 */
5126
		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
5127
			__dev_set_promiscuity(dev, 1, false);
5128
			dev->uc_promisc = true;
5129
		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
5130
			__dev_set_promiscuity(dev, -1, false);
5131
			dev->uc_promisc = false;
5132 5133
		}
	}
5134 5135 5136

	if (ops->ndo_set_rx_mode)
		ops->ndo_set_rx_mode(dev);
5137 5138 5139 5140
}

void dev_set_rx_mode(struct net_device *dev)
{
5141
	netif_addr_lock_bh(dev);
5142
	__dev_set_rx_mode(dev);
5143
	netif_addr_unlock_bh(dev);
L
Linus Torvalds 已提交
5144 5145
}

5146 5147 5148 5149 5150 5151
/**
 *	dev_get_flags - get flags reported to userspace
 *	@dev: device
 *
 *	Get the combination of flag bits exported through APIs to userspace.
 */
5152
unsigned int dev_get_flags(const struct net_device *dev)
L
Linus Torvalds 已提交
5153
{
5154
	unsigned int flags;
L
Linus Torvalds 已提交
5155 5156 5157

	flags = (dev->flags & ~(IFF_PROMISC |
				IFF_ALLMULTI |
S
Stefan Rompf 已提交
5158 5159 5160
				IFF_RUNNING |
				IFF_LOWER_UP |
				IFF_DORMANT)) |
L
Linus Torvalds 已提交
5161 5162 5163
		(dev->gflags & (IFF_PROMISC |
				IFF_ALLMULTI));

S
Stefan Rompf 已提交
5164 5165 5166 5167 5168 5169 5170 5171
	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
5172 5173 5174

	return flags;
}
E
Eric Dumazet 已提交
5175
EXPORT_SYMBOL(dev_get_flags);
L
Linus Torvalds 已提交
5176

5177
int __dev_change_flags(struct net_device *dev, unsigned int flags)
L
Linus Torvalds 已提交
5178
{
5179
	unsigned int old_flags = dev->flags;
5180
	int ret;
L
Linus Torvalds 已提交
5181

5182 5183
	ASSERT_RTNL();

L
Linus Torvalds 已提交
5184 5185 5186 5187 5188 5189 5190 5191 5192 5193 5194 5195 5196 5197
	/*
	 *	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.
	 */

5198 5199
	if ((old_flags ^ flags) & IFF_MULTICAST)
		dev_change_rx_flags(dev, IFF_MULTICAST);
5200

5201
	dev_set_rx_mode(dev);
L
Linus Torvalds 已提交
5202 5203 5204 5205 5206 5207 5208 5209 5210

	/*
	 *	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  ? */
5211
		ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev);
L
Linus Torvalds 已提交
5212 5213

		if (!ret)
5214
			dev_set_rx_mode(dev);
L
Linus Torvalds 已提交
5215 5216 5217
	}

	if ((flags ^ dev->gflags) & IFF_PROMISC) {
E
Eric Dumazet 已提交
5218
		int inc = (flags & IFF_PROMISC) ? 1 : -1;
5219
		unsigned int old_flags = dev->flags;
E
Eric Dumazet 已提交
5220

L
Linus Torvalds 已提交
5221
		dev->gflags ^= IFF_PROMISC;
5222 5223 5224 5225

		if (__dev_set_promiscuity(dev, inc, false) >= 0)
			if (dev->flags != old_flags)
				dev_set_rx_mode(dev);
L
Linus Torvalds 已提交
5226 5227 5228 5229 5230 5231 5232
	}

	/* 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
5233 5234
		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;

L
Linus Torvalds 已提交
5235
		dev->gflags ^= IFF_ALLMULTI;
5236
		__dev_set_allmulti(dev, inc, false);
L
Linus Torvalds 已提交
5237 5238
	}

5239 5240 5241
	return ret;
}

5242 5243
void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
			unsigned int gchanges)
5244 5245 5246
{
	unsigned int changes = dev->flags ^ old_flags;

5247
	if (gchanges)
5248
		rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC);
5249

5250 5251 5252 5253 5254 5255 5256 5257
	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 &&
5258 5259 5260 5261 5262 5263 5264
	    (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);
	}
5265 5266 5267 5268 5269 5270 5271 5272 5273 5274
}

/**
 *	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.
 */
5275
int dev_change_flags(struct net_device *dev, unsigned int flags)
5276
{
5277
	int ret;
5278
	unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
5279 5280 5281 5282 5283

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

5284
	changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
5285
	__dev_notify_flags(dev, old_flags, changes);
L
Linus Torvalds 已提交
5286 5287
	return ret;
}
E
Eric Dumazet 已提交
5288
EXPORT_SYMBOL(dev_change_flags);
L
Linus Torvalds 已提交
5289

5290 5291 5292 5293 5294 5295 5296
/**
 *	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
5297 5298
int dev_set_mtu(struct net_device *dev, int new_mtu)
{
5299
	const struct net_device_ops *ops = dev->netdev_ops;
L
Linus Torvalds 已提交
5300 5301 5302 5303 5304 5305 5306 5307 5308 5309 5310 5311 5312
	int err;

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

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

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

	err = 0;
5313 5314
	if (ops->ndo_change_mtu)
		err = ops->ndo_change_mtu(dev, new_mtu);
L
Linus Torvalds 已提交
5315 5316
	else
		dev->mtu = new_mtu;
5317

5318
	if (!err)
5319
		call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
L
Linus Torvalds 已提交
5320 5321
	return err;
}
E
Eric Dumazet 已提交
5322
EXPORT_SYMBOL(dev_set_mtu);
L
Linus Torvalds 已提交
5323

5324 5325 5326 5327 5328 5329 5330 5331 5332 5333 5334
/**
 *	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);

5335 5336 5337 5338 5339 5340 5341
/**
 *	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
5342 5343
int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
{
5344
	const struct net_device_ops *ops = dev->netdev_ops;
L
Linus Torvalds 已提交
5345 5346
	int err;

5347
	if (!ops->ndo_set_mac_address)
L
Linus Torvalds 已提交
5348 5349 5350 5351 5352
		return -EOPNOTSUPP;
	if (sa->sa_family != dev->type)
		return -EINVAL;
	if (!netif_device_present(dev))
		return -ENODEV;
5353
	err = ops->ndo_set_mac_address(dev, sa);
5354 5355
	if (err)
		return err;
J
Jiri Pirko 已提交
5356
	dev->addr_assign_type = NET_ADDR_SET;
5357
	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
5358
	add_device_randomness(dev->dev_addr, dev->addr_len);
5359
	return 0;
L
Linus Torvalds 已提交
5360
}
E
Eric Dumazet 已提交
5361
EXPORT_SYMBOL(dev_set_mac_address);
L
Linus Torvalds 已提交
5362

J
Jiri Pirko 已提交
5363 5364 5365
/**
 *	dev_change_carrier - Change device carrier
 *	@dev: device
5366
 *	@new_carrier: new value
J
Jiri Pirko 已提交
5367 5368 5369 5370 5371 5372 5373 5374 5375 5376 5377 5378 5379 5380 5381
 *
 *	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);

5382 5383 5384 5385 5386 5387 5388 5389 5390 5391 5392 5393 5394 5395 5396 5397 5398 5399
/**
 *	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
5400 5401
/**
 *	dev_new_index	-	allocate an ifindex
5402
 *	@net: the applicable net namespace
L
Linus Torvalds 已提交
5403 5404 5405 5406 5407
 *
 *	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.
 */
5408
static int dev_new_index(struct net *net)
L
Linus Torvalds 已提交
5409
{
5410
	int ifindex = net->ifindex;
L
Linus Torvalds 已提交
5411 5412 5413
	for (;;) {
		if (++ifindex <= 0)
			ifindex = 1;
5414
		if (!__dev_get_by_index(net, ifindex))
5415
			return net->ifindex = ifindex;
L
Linus Torvalds 已提交
5416 5417 5418 5419
	}
}

/* Delayed registration/unregisteration */
5420
static LIST_HEAD(net_todo_list);
5421
static DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
L
Linus Torvalds 已提交
5422

5423
static void net_set_todo(struct net_device *dev)
L
Linus Torvalds 已提交
5424 5425
{
	list_add_tail(&dev->todo_list, &net_todo_list);
5426
	dev_net(dev)->dev_unreg_count++;
L
Linus Torvalds 已提交
5427 5428
}

5429
static void rollback_registered_many(struct list_head *head)
5430
{
5431
	struct net_device *dev, *tmp;
5432
	LIST_HEAD(close_head);
5433

5434 5435 5436
	BUG_ON(dev_boot_phase);
	ASSERT_RTNL();

5437
	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
5438
		/* Some devices call without registering
5439 5440
		 * for initialization unwind. Remove those
		 * devices and proceed with the remaining.
5441 5442
		 */
		if (dev->reg_state == NETREG_UNINITIALIZED) {
5443 5444
			pr_debug("unregister_netdevice: device %s/%p never was registered\n",
				 dev->name, dev);
5445

5446
			WARN_ON(1);
5447 5448
			list_del(&dev->unreg_list);
			continue;
5449
		}
5450
		dev->dismantle = true;
5451
		BUG_ON(dev->reg_state != NETREG_REGISTERED);
5452
	}
5453

5454
	/* If device is running, close it first. */
5455 5456 5457
	list_for_each_entry(dev, head, unreg_list)
		list_add_tail(&dev->close_list, &close_head);
	dev_close_many(&close_head);
5458

5459
	list_for_each_entry(dev, head, unreg_list) {
5460 5461
		/* And unlink it from device chain. */
		unlist_netdevice(dev);
5462

5463 5464
		dev->reg_state = NETREG_UNREGISTERING;
	}
5465 5466 5467

	synchronize_net();

5468 5469 5470
	list_for_each_entry(dev, head, unreg_list) {
		/* Shutdown queueing discipline. */
		dev_shutdown(dev);
5471 5472


5473 5474 5475 5476
		/* Notify protocols, that we are about to destroy
		   this device. They should clean all the things.
		*/
		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5477

5478 5479
		if (!dev->rtnl_link_ops ||
		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
5480
			rtmsg_ifinfo(RTM_DELLINK, dev, ~0U, GFP_KERNEL);
5481

5482 5483 5484
		/*
		 *	Flush the unicast and multicast chains
		 */
5485
		dev_uc_flush(dev);
5486
		dev_mc_flush(dev);
5487

5488 5489
		if (dev->netdev_ops->ndo_uninit)
			dev->netdev_ops->ndo_uninit(dev);
5490

J
Jiri Pirko 已提交
5491 5492
		/* Notifier chain MUST detach us all upper devices. */
		WARN_ON(netdev_has_any_upper_dev(dev));
5493

5494 5495
		/* Remove entries from kobject tree */
		netdev_unregister_kobject(dev);
5496 5497 5498 5499
#ifdef CONFIG_XPS
		/* Remove XPS queueing entries */
		netif_reset_xps_queues_gt(dev, 0);
#endif
5500
	}
5501

5502
	synchronize_net();
5503

5504
	list_for_each_entry(dev, head, unreg_list)
5505 5506 5507 5508 5509 5510 5511 5512 5513
		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
5514
	list_del(&single);
5515 5516
}

5517 5518
static netdev_features_t netdev_fix_features(struct net_device *dev,
	netdev_features_t features)
5519
{
5520 5521 5522
	/* Fix illegal checksum combinations */
	if ((features & NETIF_F_HW_CSUM) &&
	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5523
		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
5524 5525 5526
		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
	}

5527
	/* TSO requires that SG is present as well. */
5528
	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
5529
		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
5530
		features &= ~NETIF_F_ALL_TSO;
5531 5532
	}

5533 5534 5535 5536 5537 5538 5539 5540 5541 5542 5543 5544 5545
	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;
	}

5546 5547 5548 5549
	/* TSO ECN requires that TSO is present as well. */
	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
		features &= ~NETIF_F_TSO_ECN;

5550 5551
	/* Software GSO depends on SG. */
	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
5552
		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
5553 5554 5555
		features &= ~NETIF_F_GSO;
	}

5556
	/* UFO needs SG and checksumming */
5557
	if (features & NETIF_F_UFO) {
5558 5559 5560 5561
		/* 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))) {
5562
			netdev_dbg(dev,
5563
				"Dropping NETIF_F_UFO since no checksum offload features.\n");
5564 5565 5566 5567
			features &= ~NETIF_F_UFO;
		}

		if (!(features & NETIF_F_SG)) {
5568
			netdev_dbg(dev,
5569
				"Dropping NETIF_F_UFO since no NETIF_F_SG feature.\n");
5570 5571 5572 5573 5574 5575 5576
			features &= ~NETIF_F_UFO;
		}
	}

	return features;
}

5577
int __netdev_update_features(struct net_device *dev)
5578
{
5579
	netdev_features_t features;
5580 5581
	int err = 0;

5582 5583
	ASSERT_RTNL();

5584 5585 5586 5587 5588 5589 5590 5591 5592
	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)
5593
		return 0;
5594

5595 5596
	netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
		&dev->features, &features);
5597 5598 5599 5600

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

5601
	if (unlikely(err < 0)) {
5602
		netdev_err(dev,
5603 5604
			"set_features() failed (%d); wanted %pNF, left %pNF\n",
			err, &features, &dev->features);
5605 5606 5607 5608 5609 5610 5611 5612 5613
		return -1;
	}

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

	return 1;
}

5614 5615 5616 5617 5618 5619 5620 5621
/**
 *	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.
 */
5622 5623 5624 5625
void netdev_update_features(struct net_device *dev)
{
	if (__netdev_update_features(dev))
		netdev_features_change(dev);
5626 5627 5628
}
EXPORT_SYMBOL(netdev_update_features);

5629 5630 5631 5632 5633 5634 5635 5636 5637 5638 5639 5640 5641 5642 5643 5644 5645
/**
 *	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);

5646 5647 5648 5649 5650 5651 5652 5653 5654 5655 5656 5657 5658 5659 5660 5661 5662 5663 5664 5665 5666 5667 5668 5669 5670 5671 5672
/**
 *	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);

T
Tom Herbert 已提交
5673
#ifdef CONFIG_RPS
5674 5675 5676
static int netif_alloc_rx_queues(struct net_device *dev)
{
	unsigned int i, count = dev->num_rx_queues;
T
Tom Herbert 已提交
5677
	struct netdev_rx_queue *rx;
5678

T
Tom Herbert 已提交
5679
	BUG_ON(count < 1);
5680

T
Tom Herbert 已提交
5681
	rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL);
5682
	if (!rx)
T
Tom Herbert 已提交
5683
		return -ENOMEM;
5684

T
Tom Herbert 已提交
5685 5686 5687
	dev->_rx = rx;

	for (i = 0; i < count; i++)
T
Tom Herbert 已提交
5688
		rx[i].dev = dev;
5689 5690
	return 0;
}
T
Tom Herbert 已提交
5691
#endif
5692

C
Changli Gao 已提交
5693 5694 5695 5696 5697 5698 5699
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;
5700
	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
C
Changli Gao 已提交
5701
	queue->dev = dev;
T
Tom Herbert 已提交
5702 5703 5704
#ifdef CONFIG_BQL
	dql_init(&queue->dql, HZ);
#endif
C
Changli Gao 已提交
5705 5706
}

5707 5708 5709 5710 5711 5712 5713 5714
static void netif_free_tx_queues(struct net_device *dev)
{
	if (is_vmalloc_addr(dev->_tx))
		vfree(dev->_tx);
	else
		kfree(dev->_tx);
}

5715 5716 5717 5718
static int netif_alloc_netdev_queues(struct net_device *dev)
{
	unsigned int count = dev->num_tx_queues;
	struct netdev_queue *tx;
5719
	size_t sz = count * sizeof(*tx);
5720

5721
	BUG_ON(count < 1 || count > 0xffff);
5722

5723 5724 5725 5726 5727 5728
	tx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
	if (!tx) {
		tx = vzalloc(sz);
		if (!tx)
			return -ENOMEM;
	}
5729
	dev->_tx = tx;
T
Tom Herbert 已提交
5730

5731 5732
	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
	spin_lock_init(&dev->tx_global_lock);
C
Changli Gao 已提交
5733 5734

	return 0;
5735 5736
}

L
Linus Torvalds 已提交
5737 5738 5739 5740 5741 5742 5743 5744 5745 5746 5747 5748 5749 5750 5751 5752 5753 5754 5755 5756
/**
 *	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;
5757
	struct net *net = dev_net(dev);
L
Linus Torvalds 已提交
5758 5759 5760 5761

	BUG_ON(dev_boot_phase);
	ASSERT_RTNL();

5762 5763
	might_sleep();

L
Linus Torvalds 已提交
5764 5765
	/* When net_device's are persistent, this will be fatal. */
	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
5766
	BUG_ON(!net);
L
Linus Torvalds 已提交
5767

5768
	spin_lock_init(&dev->addr_list_lock);
5769
	netdev_set_addr_lockdep_class(dev);
L
Linus Torvalds 已提交
5770 5771 5772

	dev->iflink = -1;

5773
	ret = dev_get_valid_name(net, dev, dev->name);
5774 5775 5776
	if (ret < 0)
		goto out;

L
Linus Torvalds 已提交
5777
	/* Init, if this function is available */
5778 5779
	if (dev->netdev_ops->ndo_init) {
		ret = dev->netdev_ops->ndo_init(dev);
L
Linus Torvalds 已提交
5780 5781 5782
		if (ret) {
			if (ret > 0)
				ret = -EIO;
5783
			goto out;
L
Linus Torvalds 已提交
5784 5785
		}
	}
5786

5787 5788
	if (((dev->hw_features | dev->features) &
	     NETIF_F_HW_VLAN_CTAG_FILTER) &&
5789 5790 5791 5792 5793 5794 5795
	    (!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;
	}

5796 5797 5798 5799 5800 5801
	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
5802 5803 5804
	if (dev->iflink == -1)
		dev->iflink = dev->ifindex;

5805 5806 5807 5808
	/* Transfer changeable features to wanted_features and enable
	 * software offloads (GSO and GRO).
	 */
	dev->hw_features |= NETIF_F_SOFT_FEATURES;
5809 5810
	dev->features |= NETIF_F_SOFT_FEATURES;
	dev->wanted_features = dev->features & dev->hw_features;
L
Linus Torvalds 已提交
5811

5812 5813
	if (!(dev->flags & IFF_LOOPBACK)) {
		dev->hw_features |= NETIF_F_NOCACHE_COPY;
5814 5815
	}

5816
	/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
5817
	 */
5818
	dev->vlan_features |= NETIF_F_HIGHDMA;
5819

5820 5821 5822 5823
	/* Make NETIF_F_SG inheritable to tunnel devices.
	 */
	dev->hw_enc_features |= NETIF_F_SG;

S
Simon Horman 已提交
5824 5825 5826 5827
	/* Make NETIF_F_SG inheritable to MPLS.
	 */
	dev->mpls_features |= NETIF_F_SG;

5828 5829 5830 5831 5832
	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
	ret = notifier_to_errno(ret);
	if (ret)
		goto err_uninit;

5833
	ret = netdev_register_kobject(dev);
5834
	if (ret)
5835
		goto err_uninit;
5836 5837
	dev->reg_state = NETREG_REGISTERED;

5838
	__netdev_update_features(dev);
5839

L
Linus Torvalds 已提交
5840 5841 5842 5843 5844 5845 5846
	/*
	 *	Default initial state at registry is that the
	 *	device is present.
	 */

	set_bit(__LINK_STATE_PRESENT, &dev->state);

5847 5848
	linkwatch_init_dev(dev);

L
Linus Torvalds 已提交
5849 5850
	dev_init_scheduler(dev);
	dev_hold(dev);
5851
	list_netdevice(dev);
5852
	add_device_randomness(dev->dev_addr, dev->addr_len);
L
Linus Torvalds 已提交
5853

5854 5855 5856 5857 5858 5859 5860
	/* 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
5861
	/* Notify protocols, that a new device appeared. */
5862
	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
5863
	ret = notifier_to_errno(ret);
5864 5865 5866 5867
	if (ret) {
		rollback_registered(dev);
		dev->reg_state = NETREG_UNREGISTERED;
	}
5868 5869 5870 5871
	/*
	 *	Prevent userspace races by waiting until the network
	 *	device is fully setup before sending notifications.
	 */
5872 5873
	if (!dev->rtnl_link_ops ||
	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
5874
		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
L
Linus Torvalds 已提交
5875 5876 5877

out:
	return ret;
5878 5879

err_uninit:
5880 5881
	if (dev->netdev_ops->ndo_uninit)
		dev->netdev_ops->ndo_uninit(dev);
5882
	goto out;
L
Linus Torvalds 已提交
5883
}
E
Eric Dumazet 已提交
5884
EXPORT_SYMBOL(register_netdevice);
L
Linus Torvalds 已提交
5885

5886 5887 5888 5889 5890 5891 5892 5893 5894 5895 5896 5897 5898 5899 5900 5901 5902 5903 5904 5905 5906 5907 5908 5909 5910 5911 5912 5913 5914 5915 5916
/**
 *	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
5917 5918 5919 5920 5921
	/* Note : We dont allocate pcpu_refcnt for dummy devices,
	 * because users of this 'device' dont need to change
	 * its refcount.
	 */

5922 5923 5924 5925 5926
	return 0;
}
EXPORT_SYMBOL_GPL(init_dummy_netdev);


L
Linus Torvalds 已提交
5927 5928 5929 5930 5931 5932 5933 5934 5935
/**
 *	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.
 *
5936
 *	This is a wrapper around register_netdevice that takes the rtnl semaphore
L
Linus Torvalds 已提交
5937 5938 5939 5940 5941 5942 5943 5944 5945 5946 5947 5948 5949 5950
 *	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
5951 5952 5953 5954 5955 5956 5957 5958 5959 5960
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);

5961
/**
L
Linus Torvalds 已提交
5962
 * netdev_wait_allrefs - wait until all references are gone.
5963
 * @dev: target net_device
L
Linus Torvalds 已提交
5964 5965 5966 5967 5968 5969 5970
 *
 * 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
5971
 * call dev_put.
L
Linus Torvalds 已提交
5972 5973 5974 5975
 */
static void netdev_wait_allrefs(struct net_device *dev)
{
	unsigned long rebroadcast_time, warning_time;
E
Eric Dumazet 已提交
5976
	int refcnt;
L
Linus Torvalds 已提交
5977

5978 5979
	linkwatch_forget_dev(dev);

L
Linus Torvalds 已提交
5980
	rebroadcast_time = warning_time = jiffies;
E
Eric Dumazet 已提交
5981 5982 5983
	refcnt = netdev_refcnt_read(dev);

	while (refcnt != 0) {
L
Linus Torvalds 已提交
5984
		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
5985
			rtnl_lock();
L
Linus Torvalds 已提交
5986 5987

			/* Rebroadcast unregister notification */
5988
			call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
L
Linus Torvalds 已提交
5989

5990
			__rtnl_unlock();
5991
			rcu_barrier();
5992 5993
			rtnl_lock();

5994
			call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
L
Linus Torvalds 已提交
5995 5996 5997 5998 5999 6000 6001 6002 6003 6004 6005
			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();
			}

6006
			__rtnl_unlock();
L
Linus Torvalds 已提交
6007 6008 6009 6010 6011 6012

			rebroadcast_time = jiffies;
		}

		msleep(250);

E
Eric Dumazet 已提交
6013 6014
		refcnt = netdev_refcnt_read(dev);

L
Linus Torvalds 已提交
6015
		if (time_after(jiffies, warning_time + 10 * HZ)) {
6016 6017
			pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
				 dev->name, refcnt);
L
Linus Torvalds 已提交
6018 6019 6020 6021 6022 6023 6024 6025 6026 6027 6028 6029 6030 6031 6032 6033 6034 6035 6036
			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
6037
 * We are invoked by rtnl_unlock().
L
Linus Torvalds 已提交
6038
 * This allows us to deal with problems:
6039
 * 1) We can delete sysfs objects which invoke hotplug
L
Linus Torvalds 已提交
6040 6041 6042
 *    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
6043 6044 6045
 *
 * 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
6046 6047 6048
 */
void netdev_run_todo(void)
{
6049
	struct list_head list;
L
Linus Torvalds 已提交
6050 6051

	/* Snapshot list, allow later requests */
6052
	list_replace_init(&net_todo_list, &list);
H
Herbert Xu 已提交
6053 6054

	__rtnl_unlock();
6055

6056 6057

	/* Wait for rcu callbacks to finish before next phase */
6058 6059 6060
	if (!list_empty(&list))
		rcu_barrier();

L
Linus Torvalds 已提交
6061 6062
	while (!list_empty(&list)) {
		struct net_device *dev
6063
			= list_first_entry(&list, struct net_device, todo_list);
L
Linus Torvalds 已提交
6064 6065
		list_del(&dev->todo_list);

6066
		rtnl_lock();
6067
		call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
6068
		__rtnl_unlock();
6069

6070
		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
6071
			pr_err("network todo '%s' but state %d\n",
6072 6073 6074 6075
			       dev->name, dev->reg_state);
			dump_stack();
			continue;
		}
L
Linus Torvalds 已提交
6076

6077
		dev->reg_state = NETREG_UNREGISTERED;
L
Linus Torvalds 已提交
6078

6079
		on_each_cpu(flush_backlog, dev, 1);
6080

6081
		netdev_wait_allrefs(dev);
L
Linus Torvalds 已提交
6082

6083
		/* paranoia */
E
Eric Dumazet 已提交
6084
		BUG_ON(netdev_refcnt_read(dev));
6085 6086
		WARN_ON(rcu_access_pointer(dev->ip_ptr));
		WARN_ON(rcu_access_pointer(dev->ip6_ptr));
6087
		WARN_ON(dev->dn_ptr);
L
Linus Torvalds 已提交
6088

6089 6090
		if (dev->destructor)
			dev->destructor(dev);
6091

6092 6093 6094 6095 6096 6097
		/* Report a network device has been unregistered */
		rtnl_lock();
		dev_net(dev)->dev_unreg_count--;
		__rtnl_unlock();
		wake_up(&netdev_unregistering_wq);

6098 6099
		/* Free network device */
		kobject_put(&dev->dev.kobj);
L
Linus Torvalds 已提交
6100 6101 6102
	}
}

6103 6104 6105
/* Convert net_device_stats to rtnl_link_stats64.  They have the same
 * fields in the same order, with only the type differing.
 */
6106 6107
void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
			     const struct net_device_stats *netdev_stats)
6108 6109
{
#if BITS_PER_LONG == 64
6110 6111
	BUILD_BUG_ON(sizeof(*stats64) != sizeof(*netdev_stats));
	memcpy(stats64, netdev_stats, sizeof(*stats64));
6112 6113 6114 6115 6116 6117 6118 6119 6120 6121 6122
#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
}
6123
EXPORT_SYMBOL(netdev_stats_to_stats64);
6124

6125 6126 6127
/**
 *	dev_get_stats	- get network device statistics
 *	@dev: device to get statistics from
6128
 *	@storage: place to store stats
6129
 *
6130 6131 6132 6133
 *	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.
6134
 */
6135 6136
struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
					struct rtnl_link_stats64 *storage)
6137
{
6138 6139
	const struct net_device_ops *ops = dev->netdev_ops;

6140 6141
	if (ops->ndo_get_stats64) {
		memset(storage, 0, sizeof(*storage));
6142 6143
		ops->ndo_get_stats64(dev, storage);
	} else if (ops->ndo_get_stats) {
6144
		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
6145 6146
	} else {
		netdev_stats_to_stats64(storage, &dev->stats);
6147
	}
6148
	storage->rx_dropped += atomic_long_read(&dev->rx_dropped);
6149
	return storage;
R
Rusty Russell 已提交
6150
}
6151
EXPORT_SYMBOL(dev_get_stats);
R
Rusty Russell 已提交
6152

6153
struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
6154
{
6155
	struct netdev_queue *queue = dev_ingress_queue(dev);
6156

6157 6158 6159 6160 6161 6162 6163 6164 6165 6166 6167 6168
#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;
6169 6170
}

6171 6172
static const struct ethtool_ops default_ethtool_ops;

6173 6174 6175 6176 6177 6178 6179 6180
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);

6181 6182 6183 6184 6185 6186 6187 6188 6189 6190
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
6191
/**
T
Tom Herbert 已提交
6192
 *	alloc_netdev_mqs - allocate network device
L
Linus Torvalds 已提交
6193 6194 6195
 *	@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
6196 6197
 *	@txqs:		the number of TX subqueues to allocate
 *	@rxqs:		the number of RX subqueues to allocate
L
Linus Torvalds 已提交
6198 6199
 *
 *	Allocates a struct net_device with private data area for driver use
6200
 *	and performs basic initialization.  Also allocates subquue structs
T
Tom Herbert 已提交
6201
 *	for each queue on the device.
L
Linus Torvalds 已提交
6202
 */
T
Tom Herbert 已提交
6203 6204 6205
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
6206 6207
{
	struct net_device *dev;
6208
	size_t alloc_size;
6209
	struct net_device *p;
L
Linus Torvalds 已提交
6210

6211 6212
	BUG_ON(strlen(name) >= sizeof(dev->name));

T
Tom Herbert 已提交
6213
	if (txqs < 1) {
6214
		pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
6215 6216 6217
		return NULL;
	}

T
Tom Herbert 已提交
6218 6219
#ifdef CONFIG_RPS
	if (rxqs < 1) {
6220
		pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
T
Tom Herbert 已提交
6221 6222 6223 6224
		return NULL;
	}
#endif

6225
	alloc_size = sizeof(struct net_device);
6226 6227
	if (sizeof_priv) {
		/* ensure 32-byte alignment of private area */
6228
		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
6229 6230 6231
		alloc_size += sizeof_priv;
	}
	/* ensure 32-byte alignment of whole construct */
6232
	alloc_size += NETDEV_ALIGN - 1;
L
Linus Torvalds 已提交
6233

6234 6235 6236
	p = kzalloc(alloc_size, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
	if (!p)
		p = vzalloc(alloc_size);
6237
	if (!p)
L
Linus Torvalds 已提交
6238 6239
		return NULL;

6240
	dev = PTR_ALIGN(p, NETDEV_ALIGN);
L
Linus Torvalds 已提交
6241
	dev->padded = (char *)dev - (char *)p;
6242

E
Eric Dumazet 已提交
6243 6244
	dev->pcpu_refcnt = alloc_percpu(int);
	if (!dev->pcpu_refcnt)
6245
		goto free_dev;
6246 6247

	if (dev_addr_init(dev))
E
Eric Dumazet 已提交
6248
		goto free_pcpu;
6249

6250
	dev_mc_init(dev);
6251
	dev_uc_init(dev);
J
Jiri Pirko 已提交
6252

6253
	dev_net_set(dev, &init_net);
L
Linus Torvalds 已提交
6254

6255
	dev->gso_max_size = GSO_MAX_SIZE;
6256
	dev->gso_max_segs = GSO_MAX_SEGS;
6257 6258 6259

	INIT_LIST_HEAD(&dev->napi_list);
	INIT_LIST_HEAD(&dev->unreg_list);
6260
	INIT_LIST_HEAD(&dev->close_list);
6261
	INIT_LIST_HEAD(&dev->link_watch_list);
6262 6263 6264 6265
	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);
6266 6267 6268
	dev->priv_flags = IFF_XMIT_DST_RELEASE;
	setup(dev);

T
Tom Herbert 已提交
6269 6270
	dev->num_tx_queues = txqs;
	dev->real_num_tx_queues = txqs;
6271
	if (netif_alloc_netdev_queues(dev))
6272
		goto free_all;
6273

E
Eric Dumazet 已提交
6274
#ifdef CONFIG_RPS
T
Tom Herbert 已提交
6275 6276
	dev->num_rx_queues = rxqs;
	dev->real_num_rx_queues = rxqs;
T
Tom Herbert 已提交
6277
	if (netif_alloc_rx_queues(dev))
6278
		goto free_all;
E
Eric Dumazet 已提交
6279
#endif
T
Tom Herbert 已提交
6280

L
Linus Torvalds 已提交
6281
	strcpy(dev->name, name);
6282
	dev->group = INIT_NETDEV_GROUP;
6283 6284
	if (!dev->ethtool_ops)
		dev->ethtool_ops = &default_ethtool_ops;
L
Linus Torvalds 已提交
6285
	return dev;
6286

6287 6288 6289 6290
free_all:
	free_netdev(dev);
	return NULL;

E
Eric Dumazet 已提交
6291 6292
free_pcpu:
	free_percpu(dev->pcpu_refcnt);
6293
	netif_free_tx_queues(dev);
T
Tom Herbert 已提交
6294 6295 6296 6297
#ifdef CONFIG_RPS
	kfree(dev->_rx);
#endif

6298 6299
free_dev:
	netdev_freemem(dev);
6300
	return NULL;
L
Linus Torvalds 已提交
6301
}
T
Tom Herbert 已提交
6302
EXPORT_SYMBOL(alloc_netdev_mqs);
L
Linus Torvalds 已提交
6303 6304 6305 6306 6307

/**
 *	free_netdev - free network device
 *	@dev: device
 *
6308 6309
 *	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
6310 6311 6312 6313
 *	If this is the last reference then it will be freed.
 */
void free_netdev(struct net_device *dev)
{
6314 6315
	struct napi_struct *p, *n;

6316 6317
	release_net(dev_net(dev));

6318
	netif_free_tx_queues(dev);
T
Tom Herbert 已提交
6319 6320 6321
#ifdef CONFIG_RPS
	kfree(dev->_rx);
#endif
6322

6323
	kfree(rcu_dereference_protected(dev->ingress_queue, 1));
6324

6325 6326 6327
	/* Flush device addresses */
	dev_addr_flush(dev);

6328 6329 6330
	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
		netif_napi_del(p);

E
Eric Dumazet 已提交
6331 6332 6333
	free_percpu(dev->pcpu_refcnt);
	dev->pcpu_refcnt = NULL;

S
Stephen Hemminger 已提交
6334
	/*  Compatibility with error handling in drivers */
L
Linus Torvalds 已提交
6335
	if (dev->reg_state == NETREG_UNINITIALIZED) {
6336
		netdev_freemem(dev);
L
Linus Torvalds 已提交
6337 6338 6339 6340 6341 6342
		return;
	}

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

6343 6344
	/* will free via device release */
	put_device(&dev->dev);
L
Linus Torvalds 已提交
6345
}
E
Eric Dumazet 已提交
6346
EXPORT_SYMBOL(free_netdev);
6347

6348 6349 6350 6351 6352 6353
/**
 *	synchronize_net -  Synchronize with packet receive processing
 *
 *	Wait for packets currently being received to be done.
 *	Does not block later packets from starting.
 */
6354
void synchronize_net(void)
L
Linus Torvalds 已提交
6355 6356
{
	might_sleep();
6357 6358 6359 6360
	if (rtnl_is_locked())
		synchronize_rcu_expedited();
	else
		synchronize_rcu();
L
Linus Torvalds 已提交
6361
}
E
Eric Dumazet 已提交
6362
EXPORT_SYMBOL(synchronize_net);
L
Linus Torvalds 已提交
6363 6364

/**
6365
 *	unregister_netdevice_queue - remove device from the kernel
L
Linus Torvalds 已提交
6366
 *	@dev: device
6367
 *	@head: list
6368
 *
L
Linus Torvalds 已提交
6369
 *	This function shuts down a device interface and removes it
6370
 *	from the kernel tables.
6371
 *	If head not NULL, device is queued to be unregistered later.
L
Linus Torvalds 已提交
6372 6373 6374 6375 6376
 *
 *	Callers must hold the rtnl semaphore.  You may want
 *	unregister_netdev() instead of this.
 */

6377
void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
L
Linus Torvalds 已提交
6378
{
6379 6380
	ASSERT_RTNL();

6381
	if (head) {
6382
		list_move_tail(&dev->unreg_list, head);
6383 6384 6385 6386 6387
	} else {
		rollback_registered(dev);
		/* Finish processing unregister after unlock */
		net_set_todo(dev);
	}
L
Linus Torvalds 已提交
6388
}
6389
EXPORT_SYMBOL(unregister_netdevice_queue);
L
Linus Torvalds 已提交
6390

6391 6392 6393 6394 6395 6396 6397 6398 6399 6400 6401 6402 6403 6404
/**
 *	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);
	}
}
6405
EXPORT_SYMBOL(unregister_netdevice_many);
6406

L
Linus Torvalds 已提交
6407 6408 6409 6410 6411
/**
 *	unregister_netdev - remove device from the kernel
 *	@dev: device
 *
 *	This function shuts down a device interface and removes it
6412
 *	from the kernel tables.
L
Linus Torvalds 已提交
6413 6414 6415 6416 6417 6418 6419 6420 6421 6422 6423 6424 6425
 *
 *	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);

6426 6427 6428 6429 6430 6431 6432 6433 6434 6435 6436 6437 6438 6439 6440 6441 6442 6443 6444 6445 6446 6447 6448 6449 6450 6451 6452 6453 6454 6455 6456
/**
 *	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;
6457
	if (net_eq(dev_net(dev), net))
6458 6459 6460 6461 6462 6463
		goto out;

	/* Pick the destination device name, and ensure
	 * we can use it in the destination network namespace.
	 */
	err = -EEXIST;
6464
	if (__dev_get_by_name(net, dev->name)) {
6465 6466 6467
		/* We get here if we can't use the current device name */
		if (!pat)
			goto out;
6468
		if (dev_get_valid_name(net, dev, pat) < 0)
6469 6470 6471 6472 6473 6474 6475 6476
			goto out;
	}

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

	/* If device is running close it first. */
6477
	dev_close(dev);
6478 6479 6480 6481 6482 6483 6484 6485 6486 6487 6488 6489

	/* 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.
6490 6491 6492 6493

	   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.
6494 6495
	*/
	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
6496 6497
	rcu_barrier();
	call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
6498
	rtmsg_ifinfo(RTM_DELLINK, dev, ~0U, GFP_KERNEL);
6499 6500 6501 6502

	/*
	 *	Flush the unicast and multicast chains
	 */
6503
	dev_uc_flush(dev);
6504
	dev_mc_flush(dev);
6505

6506 6507 6508
	/* Send a netdev-removed uevent to the old namespace */
	kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);

6509
	/* Actually switch the network namespace */
6510
	dev_net_set(dev, net);
6511 6512 6513 6514 6515 6516 6517 6518 6519

	/* 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;
	}

6520 6521 6522
	/* Send a netdev-add uevent to the new namespace */
	kobject_uevent(&dev->dev.kobj, KOBJ_ADD);

6523
	/* Fixup kobjects */
6524
	err = device_rename(&dev->dev, dev->name);
6525
	WARN_ON(err);
6526 6527 6528 6529 6530 6531 6532

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

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

6533 6534 6535 6536
	/*
	 *	Prevent userspace races by waiting until the network
	 *	device is fully setup before sending notifications.
	 */
6537
	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
6538

6539 6540 6541 6542 6543
	synchronize_net();
	err = 0;
out:
	return err;
}
6544
EXPORT_SYMBOL_GPL(dev_change_net_namespace);
6545

L
Linus Torvalds 已提交
6546 6547 6548 6549 6550 6551 6552 6553 6554
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;

6555
	if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
L
Linus Torvalds 已提交
6556 6557 6558 6559 6560 6561 6562 6563 6564 6565 6566 6567 6568 6569 6570 6571
		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. */
6572 6573 6574 6575 6576 6577
	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;
	}
6578 6579 6580 6581 6582
	/* 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
6583 6584 6585 6586 6587

	raise_softirq_irqoff(NET_TX_SOFTIRQ);
	local_irq_enable();

	/* Process offline CPU's input_pkt_queue */
6588
	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
L
Linus Torvalds 已提交
6589
		netif_rx(skb);
6590
		input_queue_head_incr(oldsd);
T
Tom Herbert 已提交
6591
	}
6592
	while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
6593
		netif_rx(skb);
6594 6595
		input_queue_head_incr(oldsd);
	}
L
Linus Torvalds 已提交
6596 6597 6598 6599 6600

	return NOTIFY_OK;
}


6601
/**
6602 6603 6604 6605
 *	netdev_increment_features - increment feature set by one
 *	@all: current feature set
 *	@one: new feature set
 *	@mask: mask feature set
6606 6607
 *
 *	Computes a new feature set after adding a device with feature set
6608 6609
 *	@one to the master device with current feature set @all.  Will not
 *	enable anything that is off in @mask. Returns the new feature set.
6610
 */
6611 6612
netdev_features_t netdev_increment_features(netdev_features_t all,
	netdev_features_t one, netdev_features_t mask)
6613
{
6614 6615 6616
	if (mask & NETIF_F_GEN_CSUM)
		mask |= NETIF_F_ALL_CSUM;
	mask |= NETIF_F_VLAN_CHALLENGED;
6617

6618 6619
	all |= one & (NETIF_F_ONE_FOR_ALL|NETIF_F_ALL_CSUM) & mask;
	all &= one | ~NETIF_F_ALL_FOR_ALL;
6620

6621 6622 6623
	/* If one device supports hw checksumming, set for all. */
	if (all & NETIF_F_GEN_CSUM)
		all &= ~(NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM);
6624 6625 6626

	return all;
}
6627
EXPORT_SYMBOL(netdev_increment_features);
6628

6629
static struct hlist_head * __net_init netdev_create_hash(void)
6630 6631 6632 6633 6634 6635 6636 6637 6638 6639 6640 6641
{
	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;
}

6642
/* Initialize per network namespace state */
6643
static int __net_init netdev_init(struct net *net)
6644
{
6645 6646
	if (net != &init_net)
		INIT_LIST_HEAD(&net->dev_base_head);
6647

6648 6649 6650
	net->dev_name_head = netdev_create_hash();
	if (net->dev_name_head == NULL)
		goto err_name;
6651

6652 6653 6654
	net->dev_index_head = netdev_create_hash();
	if (net->dev_index_head == NULL)
		goto err_idx;
6655 6656

	return 0;
6657 6658 6659 6660 6661

err_idx:
	kfree(net->dev_name_head);
err_name:
	return -ENOMEM;
6662 6663
}

6664 6665 6666 6667 6668 6669
/**
 *	netdev_drivername - network driver for the device
 *	@dev: network device
 *
 *	Determine network driver for device.
 */
6670
const char *netdev_drivername(const struct net_device *dev)
6671
{
6672 6673
	const struct device_driver *driver;
	const struct device *parent;
6674
	const char *empty = "";
6675 6676 6677

	parent = dev->dev.parent;
	if (!parent)
6678
		return empty;
6679 6680 6681

	driver = parent->driver;
	if (driver && driver->name)
6682 6683
		return driver->name;
	return empty;
6684 6685
}

6686
static int __netdev_printk(const char *level, const struct net_device *dev,
6687 6688 6689 6690
			   struct va_format *vaf)
{
	int r;

6691
	if (dev && dev->dev.parent) {
6692 6693 6694 6695 6696 6697
		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);
6698
	} else if (dev) {
6699
		r = printk("%s%s: %pV", level, netdev_name(dev), vaf);
6700
	} else {
6701
		r = printk("%s(NULL net_device): %pV", level, vaf);
6702
	}
6703 6704 6705 6706 6707 6708 6709 6710 6711 6712 6713 6714 6715 6716 6717 6718 6719

	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);
6720

6721 6722 6723 6724 6725 6726 6727 6728 6729 6730 6731 6732 6733 6734 6735 6736 6737 6738 6739
	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);			\
6740
								\
6741 6742 6743 6744 6745 6746 6747 6748 6749 6750 6751 6752 6753 6754
	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);

6755
static void __net_exit netdev_exit(struct net *net)
6756 6757 6758 6759 6760
{
	kfree(net->dev_name_head);
	kfree(net->dev_index_head);
}

6761
static struct pernet_operations __net_initdata netdev_net_ops = {
6762 6763 6764 6765
	.init = netdev_init,
	.exit = netdev_exit,
};

6766
static void __net_exit default_device_exit(struct net *net)
6767
{
6768
	struct net_device *dev, *aux;
6769
	/*
6770
	 * Push all migratable network devices back to the
6771 6772 6773
	 * initial network namespace
	 */
	rtnl_lock();
6774
	for_each_netdev_safe(net, dev, aux) {
6775
		int err;
6776
		char fb_name[IFNAMSIZ];
6777 6778 6779 6780 6781

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

6782 6783 6784
		/* Leave virtual devices for the generic cleanup */
		if (dev->rtnl_link_ops)
			continue;
6785

L
Lucas De Marchi 已提交
6786
		/* Push remaining network devices to init_net */
6787 6788
		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
		err = dev_change_net_namespace(dev, &init_net, fb_name);
6789
		if (err) {
6790 6791
			pr_emerg("%s: failed to move %s to init_net: %d\n",
				 __func__, dev->name, err);
6792
			BUG();
6793 6794 6795 6796 6797
		}
	}
	rtnl_unlock();
}

6798 6799 6800 6801 6802 6803 6804 6805 6806 6807 6808 6809 6810 6811 6812 6813 6814 6815 6816 6817 6818 6819 6820 6821 6822 6823 6824 6825
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);
}

6826 6827 6828
static void __net_exit default_device_exit_batch(struct list_head *net_list)
{
	/* At exit all network devices most be removed from a network
6829
	 * namespace.  Do this in the reverse order of registration.
6830 6831 6832 6833 6834 6835 6836
	 * 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);

6837 6838 6839 6840 6841 6842 6843 6844 6845 6846 6847 6848
	/* 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);
6849 6850 6851 6852 6853 6854 6855 6856 6857
	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
6858
	list_del(&dev_kill_list);
6859 6860 6861
	rtnl_unlock();
}

6862
static struct pernet_operations __net_initdata default_device_ops = {
6863
	.exit = default_device_exit,
6864
	.exit_batch = default_device_exit_batch,
6865 6866
};

L
Linus Torvalds 已提交
6867 6868 6869 6870 6871 6872 6873 6874 6875 6876 6877 6878 6879 6880 6881 6882 6883 6884 6885 6886
/*
 *	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;

6887
	if (netdev_kobject_init())
L
Linus Torvalds 已提交
6888 6889 6890
		goto out;

	INIT_LIST_HEAD(&ptype_all);
6891
	for (i = 0; i < PTYPE_HASH_SIZE; i++)
L
Linus Torvalds 已提交
6892 6893
		INIT_LIST_HEAD(&ptype_base[i]);

6894 6895
	INIT_LIST_HEAD(&offload_base);

6896 6897
	if (register_pernet_subsys(&netdev_net_ops))
		goto out;
L
Linus Torvalds 已提交
6898 6899 6900 6901 6902

	/*
	 *	Initialise the packet receive queues.
	 */

6903
	for_each_possible_cpu(i) {
E
Eric Dumazet 已提交
6904
		struct softnet_data *sd = &per_cpu(softnet_data, i);
L
Linus Torvalds 已提交
6905

C
Changli Gao 已提交
6906
		memset(sd, 0, sizeof(*sd));
E
Eric Dumazet 已提交
6907
		skb_queue_head_init(&sd->input_pkt_queue);
6908
		skb_queue_head_init(&sd->process_queue);
E
Eric Dumazet 已提交
6909 6910
		sd->completion_queue = NULL;
		INIT_LIST_HEAD(&sd->poll_list);
6911 6912
		sd->output_queue = NULL;
		sd->output_queue_tailp = &sd->output_queue;
E
Eric Dumazet 已提交
6913
#ifdef CONFIG_RPS
E
Eric Dumazet 已提交
6914 6915 6916 6917
		sd->csd.func = rps_trigger_softirq;
		sd->csd.info = sd;
		sd->csd.flags = 0;
		sd->cpu = i;
6918
#endif
T
Tom Herbert 已提交
6919

E
Eric Dumazet 已提交
6920 6921 6922 6923
		sd->backlog.poll = process_backlog;
		sd->backlog.weight = weight_p;
		sd->backlog.gro_list = NULL;
		sd->backlog.gro_count = 0;
6924 6925 6926 6927

#ifdef CONFIG_NET_FLOW_LIMIT
		sd->flow_limit = NULL;
#endif
L
Linus Torvalds 已提交
6928 6929 6930 6931
	}

	dev_boot_phase = 0;

6932 6933 6934 6935 6936 6937 6938 6939 6940 6941 6942 6943 6944 6945 6946
	/* 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;

6947 6948
	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
L
Linus Torvalds 已提交
6949 6950 6951 6952 6953 6954 6955 6956 6957

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

subsys_initcall(net_dev_init);