dev.c 165.8 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 "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.
 */
void __dev_remove_offload(struct packet_offload *po)
{
	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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}
EXPORT_SYMBOL(__dev_remove_offload);

/**
 *	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;
}
E
Eric Dumazet 已提交
584
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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{
E
Eric Dumazet 已提交
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	struct net_device *dev;
	struct hlist_head *head = dev_name_hash(net, name);
L
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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
676
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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Linus Torvalds 已提交
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{
E
Eric Dumazet 已提交
742 743
	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

L
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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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777 778 779

/**
 *	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
800
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;
L
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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
894
 *	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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 */

E
Eric Dumazet 已提交
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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;
L
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917
}
E
Eric Dumazet 已提交
918
EXPORT_SYMBOL(dev_get_by_flags_rcu);
L
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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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951 952
 *
 *	Passed a format string - eg "lt%d" it will try and find a suitable
S
Stephen Hemminger 已提交
953 954 955 956 957 958
 *	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) {
L
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			if (!sscanf(d->name, name, &i))
				continue;
			if (i < 0 || i >= max_netdevices)
				continue;

			/*  avoid cases where sscanf is not exact inverse of printf */
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);
L
Linus Torvalds 已提交
1206 1207 1208
		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
	}
}
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 1296 1297 1298 1299 1300 1301 1302
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;

	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
	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 1311
	list_for_each_entry(dev, head, unreg_list) {
		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 1327
	list_for_each_entry(dev, head, unreg_list) {
		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->unreg_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 1365
{
	struct net_device *dev, *tmp;
	LIST_HEAD(tmp_list);
L
Linus Torvalds 已提交
1366

1367 1368 1369 1370 1371
	list_for_each_entry_safe(dev, tmp, head, unreg_list)
		if (!(dev->flags & IFF_UP))
			list_move(&dev->unreg_list, &tmp_list);

	__dev_close_many(head);
L
Linus Torvalds 已提交
1372

1373 1374 1375 1376
	list_for_each_entry(dev, head, unreg_list) {
		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
		call_netdevice_notifiers(NETDEV_DOWN, dev);
	}
1377

1378 1379
	/* rollback_registered_many needs the complete original list */
	list_splice(&tmp_list, head);
1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393
	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)
{
1394 1395
	if (dev->flags & IFF_UP) {
		LIST_HEAD(single);
L
Linus Torvalds 已提交
1396

1397
		/* Block netpoll rx while the interface is going down */
1398
		netpoll_rx_disable(dev);
1399

1400 1401 1402
		list_add(&dev->unreg_list, &single);
		dev_close_many(&single);
		list_del(&single);
1403 1404

		netpoll_rx_enable(dev);
1405
	}
1406
	return 0;
L
Linus Torvalds 已提交
1407
}
E
Eric Dumazet 已提交
1408
EXPORT_SYMBOL(dev_close);
L
Linus Torvalds 已提交
1409 1410


1411 1412 1413 1414 1415 1416 1417 1418 1419 1420
/**
 *	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)
{
1421 1422 1423 1424 1425 1426 1427
	/*
	 * 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);

M
Michał Mirosław 已提交
1428 1429
	dev->wanted_features &= ~NETIF_F_LRO;
	netdev_update_features(dev);
1430

1431 1432
	if (unlikely(dev->features & NETIF_F_LRO))
		netdev_WARN(dev, "failed to disable LRO!\n");
1433 1434 1435
}
EXPORT_SYMBOL(dev_disable_lro);

1436 1437 1438 1439 1440 1441 1442 1443
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);
}
1444

1445 1446
static int dev_boot_phase = 1;

L
Linus Torvalds 已提交
1447 1448 1449 1450 1451 1452 1453 1454 1455 1456
/**
 *	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
1457
 *	to the new notifier to allow device to have a race free
L
Linus Torvalds 已提交
1458 1459 1460 1461 1462 1463
 *	view of the network device list.
 */

int register_netdevice_notifier(struct notifier_block *nb)
{
	struct net_device *dev;
1464
	struct net_device *last;
1465
	struct net *net;
L
Linus Torvalds 已提交
1466 1467 1468
	int err;

	rtnl_lock();
1469
	err = raw_notifier_chain_register(&netdev_chain, nb);
1470 1471
	if (err)
		goto unlock;
1472 1473 1474 1475
	if (dev_boot_phase)
		goto unlock;
	for_each_net(net) {
		for_each_netdev(net, dev) {
1476
			err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1477 1478 1479 1480 1481 1482
			err = notifier_to_errno(err);
			if (err)
				goto rollback;

			if (!(dev->flags & IFF_UP))
				continue;
L
Linus Torvalds 已提交
1483

1484
			call_netdevice_notifier(nb, NETDEV_UP, dev);
1485
		}
L
Linus Torvalds 已提交
1486
	}
1487 1488

unlock:
L
Linus Torvalds 已提交
1489 1490
	rtnl_unlock();
	return err;
1491 1492 1493

rollback:
	last = dev;
1494 1495 1496
	for_each_net(net) {
		for_each_netdev(net, dev) {
			if (dev == last)
1497
				goto outroll;
1498

1499
			if (dev->flags & IFF_UP) {
1500 1501 1502
				call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
							dev);
				call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1503
			}
1504
			call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1505 1506
		}
	}
1507

1508
outroll:
1509
	raw_notifier_chain_unregister(&netdev_chain, nb);
1510
	goto unlock;
L
Linus Torvalds 已提交
1511
}
E
Eric Dumazet 已提交
1512
EXPORT_SYMBOL(register_netdevice_notifier);
L
Linus Torvalds 已提交
1513 1514 1515 1516 1517 1518 1519 1520 1521

/**
 *	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.
1522 1523 1524 1525
 *
 * 	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
1526 1527 1528 1529
 */

int unregister_netdevice_notifier(struct notifier_block *nb)
{
1530 1531
	struct net_device *dev;
	struct net *net;
1532 1533 1534
	int err;

	rtnl_lock();
1535
	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1536 1537 1538 1539 1540 1541
	if (err)
		goto unlock;

	for_each_net(net) {
		for_each_netdev(net, dev) {
			if (dev->flags & IFF_UP) {
1542 1543 1544
				call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
							dev);
				call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1545
			}
1546
			call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1547 1548 1549
		}
	}
unlock:
1550 1551
	rtnl_unlock();
	return err;
L
Linus Torvalds 已提交
1552
}
E
Eric Dumazet 已提交
1553
EXPORT_SYMBOL(unregister_netdevice_notifier);
L
Linus Torvalds 已提交
1554

1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573
/**
 *	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().
 */

int call_netdevice_notifiers_info(unsigned long val, struct net_device *dev,
				  struct netdev_notifier_info *info)
{
	ASSERT_RTNL();
	netdev_notifier_info_init(info, dev);
	return raw_notifier_call_chain(&netdev_chain, val, info);
}
EXPORT_SYMBOL(call_netdevice_notifiers_info);

L
Linus Torvalds 已提交
1574 1575 1576
/**
 *	call_netdevice_notifiers - call all network notifier blocks
 *      @val: value passed unmodified to notifier function
1577
 *      @dev: net_device pointer passed unmodified to notifier function
L
Linus Torvalds 已提交
1578 1579
 *
 *	Call all network notifier blocks.  Parameters and return value
1580
 *	are as for raw_notifier_call_chain().
L
Linus Torvalds 已提交
1581 1582
 */

1583
int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
L
Linus Torvalds 已提交
1584
{
1585 1586 1587
	struct netdev_notifier_info info;

	return call_netdevice_notifiers_info(val, dev, &info);
L
Linus Torvalds 已提交
1588
}
1589
EXPORT_SYMBOL(call_netdevice_notifiers);
L
Linus Torvalds 已提交
1590

1591
static struct static_key netstamp_needed __read_mostly;
1592
#ifdef HAVE_JUMP_LABEL
1593
/* We are not allowed to call static_key_slow_dec() from irq context
1594
 * If net_disable_timestamp() is called from irq context, defer the
1595
 * static_key_slow_dec() calls.
1596 1597 1598
 */
static atomic_t netstamp_needed_deferred;
#endif
L
Linus Torvalds 已提交
1599 1600 1601

void net_enable_timestamp(void)
{
1602 1603 1604 1605 1606
#ifdef HAVE_JUMP_LABEL
	int deferred = atomic_xchg(&netstamp_needed_deferred, 0);

	if (deferred) {
		while (--deferred)
1607
			static_key_slow_dec(&netstamp_needed);
1608 1609 1610
		return;
	}
#endif
1611
	static_key_slow_inc(&netstamp_needed);
L
Linus Torvalds 已提交
1612
}
E
Eric Dumazet 已提交
1613
EXPORT_SYMBOL(net_enable_timestamp);
L
Linus Torvalds 已提交
1614 1615 1616

void net_disable_timestamp(void)
{
1617 1618 1619 1620 1621 1622
#ifdef HAVE_JUMP_LABEL
	if (in_interrupt()) {
		atomic_inc(&netstamp_needed_deferred);
		return;
	}
#endif
1623
	static_key_slow_dec(&netstamp_needed);
L
Linus Torvalds 已提交
1624
}
E
Eric Dumazet 已提交
1625
EXPORT_SYMBOL(net_disable_timestamp);
L
Linus Torvalds 已提交
1626

E
Eric Dumazet 已提交
1627
static inline void net_timestamp_set(struct sk_buff *skb)
L
Linus Torvalds 已提交
1628
{
1629
	skb->tstamp.tv64 = 0;
1630
	if (static_key_false(&netstamp_needed))
1631
		__net_timestamp(skb);
L
Linus Torvalds 已提交
1632 1633
}

1634
#define net_timestamp_check(COND, SKB)			\
1635
	if (static_key_false(&netstamp_needed)) {		\
1636 1637 1638
		if ((COND) && !(SKB)->tstamp.tv64)	\
			__net_timestamp(SKB);		\
	}						\
E
Eric Dumazet 已提交
1639

1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660
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;
}

1661 1662 1663 1664 1665 1666 1667 1668
/**
 * dev_forward_skb - loopback an skb to another netif
 *
 * @dev: destination network device
 * @skb: buffer to forward
 *
 * return values:
 *	NET_RX_SUCCESS	(no congestion)
1669
 *	NET_RX_DROP     (packet was dropped, but freed)
1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680
 *
 * 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)
{
1681 1682 1683 1684 1685 1686 1687 1688
	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;
		}
	}

1689
	if (unlikely(!is_skb_forwardable(dev, skb))) {
1690
		atomic_long_inc(&dev->rx_dropped);
1691
		kfree_skb(skb);
1692
		return NET_RX_DROP;
1693
	}
1694
	skb->protocol = eth_type_trans(skb, dev);
1695 1696

	/* eth_type_trans() can set pkt_type.
1697 1698
	 * call skb_scrub_packet() after it to clear pkt_type _after_ calling
	 * eth_type_trans().
1699
	 */
1700
	skb_scrub_packet(skb);
1701

1702 1703 1704 1705
	return netif_rx(skb);
}
EXPORT_SYMBOL_GPL(dev_forward_skb);

1706 1707 1708 1709
static inline int deliver_skb(struct sk_buff *skb,
			      struct packet_type *pt_prev,
			      struct net_device *orig_dev)
{
1710 1711
	if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
		return -ENOMEM;
1712 1713 1714 1715
	atomic_inc(&skb->users);
	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
}

1716 1717
static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
{
1718
	if (!ptype->af_packet_priv || !skb->sk)
1719 1720 1721 1722 1723 1724 1725 1726 1727 1728
		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
1729 1730 1731 1732 1733
/*
 *	Support routine. Sends outgoing frames to any network
 *	taps currently in use.
 */

1734
static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
L
Linus Torvalds 已提交
1735 1736
{
	struct packet_type *ptype;
1737 1738
	struct sk_buff *skb2 = NULL;
	struct packet_type *pt_prev = NULL;
1739

L
Linus Torvalds 已提交
1740 1741 1742 1743 1744 1745
	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) &&
1746
		    (!skb_loop_sk(ptype, skb))) {
1747 1748 1749 1750 1751 1752 1753
			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
1754 1755 1756
			if (!skb2)
				break;

1757 1758
			net_timestamp_set(skb2);

L
Linus Torvalds 已提交
1759 1760 1761 1762
			/* skb->nh should be correctly
			   set by sender, so that the second statement is
			   just protection against buggy protocols.
			 */
1763
			skb_reset_mac_header(skb2);
L
Linus Torvalds 已提交
1764

1765
			if (skb_network_header(skb2) < skb2->data ||
1766
			    skb_network_header(skb2) > skb_tail_pointer(skb2)) {
1767 1768 1769
				net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
						     ntohs(skb2->protocol),
						     dev->name);
1770
				skb_reset_network_header(skb2);
L
Linus Torvalds 已提交
1771 1772
			}

1773
			skb2->transport_header = skb2->network_header;
L
Linus Torvalds 已提交
1774
			skb2->pkt_type = PACKET_OUTGOING;
1775
			pt_prev = ptype;
L
Linus Torvalds 已提交
1776 1777
		}
	}
1778 1779
	if (pt_prev)
		pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
L
Linus Torvalds 已提交
1780 1781 1782
	rcu_read_unlock();
}

1783 1784
/**
 * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795
 * @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
1796
static void netif_setup_tc(struct net_device *dev, unsigned int txq)
1797 1798 1799 1800 1801 1802
{
	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) {
1803
		pr_warn("Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
1804 1805 1806 1807 1808 1809 1810 1811 1812 1813
		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) {
1814 1815
			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);
1816 1817 1818 1819 1820
			netdev_set_prio_tc_map(dev, i, 0);
		}
	}
}

1821 1822 1823 1824 1825
#ifdef CONFIG_XPS
static DEFINE_MUTEX(xps_map_mutex);
#define xmap_dereference(P)		\
	rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))

1826 1827
static struct xps_map *remove_xps_queue(struct xps_dev_maps *dev_maps,
					int cpu, u16 index)
1828
{
1829 1830
	struct xps_map *map = NULL;
	int pos;
1831

1832 1833
	if (dev_maps)
		map = xmap_dereference(dev_maps->cpu_map[cpu]);
1834

1835 1836
	for (pos = 0; map && pos < map->len; pos++) {
		if (map->queues[pos] == index) {
1837 1838 1839
			if (map->len > 1) {
				map->queues[pos] = map->queues[--map->len];
			} else {
1840
				RCU_INIT_POINTER(dev_maps->cpu_map[cpu], NULL);
1841 1842 1843
				kfree_rcu(map, rcu);
				map = NULL;
			}
1844
			break;
1845 1846 1847
		}
	}

1848 1849 1850
	return map;
}

1851
static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
1852 1853
{
	struct xps_dev_maps *dev_maps;
1854
	int cpu, i;
1855 1856 1857 1858 1859 1860 1861 1862 1863
	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) {
1864 1865 1866 1867 1868
		for (i = index; i < dev->num_tx_queues; i++) {
			if (!remove_xps_queue(dev_maps, cpu, i))
				break;
		}
		if (i == dev->num_tx_queues)
1869 1870 1871 1872
			active = true;
	}

	if (!active) {
1873 1874 1875 1876
		RCU_INIT_POINTER(dev->xps_maps, NULL);
		kfree_rcu(dev_maps, rcu);
	}

1877 1878 1879 1880
	for (i = index; i < dev->num_tx_queues; i++)
		netdev_queue_numa_node_write(netdev_get_tx_queue(dev, i),
					     NUMA_NO_NODE);

1881 1882 1883 1884
out_no_maps:
	mutex_unlock(&xps_map_mutex);
}

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 1919
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;
}

1920 1921
int netif_set_xps_queue(struct net_device *dev, struct cpumask *mask, u16 index)
{
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
void dev_kfree_skb_irq(struct sk_buff *skb)
2148
{
2149
	if (atomic_dec_and_test(&skb->users)) {
2150 2151
		struct softnet_data *sd;
		unsigned long flags;
2152

2153 2154 2155 2156 2157 2158 2159
		local_irq_save(flags);
		sd = &__get_cpu_var(softnet_data);
		skb->next = sd->completion_queue;
		sd->completion_queue = skb;
		raise_softirq_irqoff(NET_TX_SOFTIRQ);
		local_irq_restore(flags);
	}
2160
}
2161
EXPORT_SYMBOL(dev_kfree_skb_irq);
2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172

void dev_kfree_skb_any(struct sk_buff *skb)
{
	if (in_irq() || irqs_disabled())
		dev_kfree_skb_irq(skb);
	else
		dev_kfree_skb(skb);
}
EXPORT_SYMBOL(dev_kfree_skb_any);


2173 2174 2175 2176 2177 2178
/**
 * netif_device_detach - mark device as removed
 * @dev: network device
 *
 * Mark device as removed from system and therefore no longer available.
 */
2179 2180 2181 2182
void netif_device_detach(struct net_device *dev)
{
	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
	    netif_running(dev)) {
2183
		netif_tx_stop_all_queues(dev);
2184 2185 2186 2187
	}
}
EXPORT_SYMBOL(netif_device_detach);

2188 2189 2190 2191 2192 2193
/**
 * netif_device_attach - mark device as attached
 * @dev: network device
 *
 * Mark device as attached from system and restart if needed.
 */
2194 2195 2196 2197
void netif_device_attach(struct net_device *dev)
{
	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
	    netif_running(dev)) {
2198
		netif_tx_wake_all_queues(dev);
2199
		__netdev_watchdog_up(dev);
2200 2201 2202 2203
	}
}
EXPORT_SYMBOL(netif_device_attach);

2204 2205
static void skb_warn_bad_offload(const struct sk_buff *skb)
{
2206
	static const netdev_features_t null_features = 0;
2207 2208 2209
	struct net_device *dev = skb->dev;
	const char *driver = "";

2210 2211 2212
	if (!net_ratelimit())
		return;

2213 2214 2215 2216 2217
	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",
2218 2219
	     driver, dev ? &dev->features : &null_features,
	     skb->sk ? &skb->sk->sk_route_caps : &null_features,
2220 2221 2222 2223
	     skb->len, skb->data_len, skb_shinfo(skb)->gso_size,
	     skb_shinfo(skb)->gso_type, skb->ip_summed);
}

L
Linus Torvalds 已提交
2224 2225 2226 2227
/*
 * Invalidate hardware checksum when packet is to be mangled, and
 * complete checksum manually on outgoing path.
 */
2228
int skb_checksum_help(struct sk_buff *skb)
L
Linus Torvalds 已提交
2229
{
2230
	__wsum csum;
2231
	int ret = 0, offset;
L
Linus Torvalds 已提交
2232

2233
	if (skb->ip_summed == CHECKSUM_COMPLETE)
2234 2235 2236
		goto out_set_summed;

	if (unlikely(skb_shinfo(skb)->gso_size)) {
2237 2238
		skb_warn_bad_offload(skb);
		return -EINVAL;
L
Linus Torvalds 已提交
2239 2240
	}

2241 2242 2243 2244 2245 2246 2247 2248 2249
	/* 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;
	}

2250
	offset = skb_checksum_start_offset(skb);
2251 2252 2253 2254 2255 2256 2257 2258
	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
2259 2260 2261 2262 2263
		ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
		if (ret)
			goto out;
	}

2264
	*(__sum16 *)(skb->data + offset) = csum_fold(csum);
2265
out_set_summed:
L
Linus Torvalds 已提交
2266
	skb->ip_summed = CHECKSUM_NONE;
2267
out:
L
Linus Torvalds 已提交
2268 2269
	return ret;
}
E
Eric Dumazet 已提交
2270
EXPORT_SYMBOL(skb_checksum_help);
L
Linus Torvalds 已提交
2271

2272
__be16 skb_network_protocol(struct sk_buff *skb)
2273
{
A
Al Viro 已提交
2274
	__be16 type = skb->protocol;
2275
	int vlan_depth = ETH_HLEN;
2276

2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287
	/* 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
2288
	while (type == htons(ETH_P_8021Q) || type == htons(ETH_P_8021AD)) {
2289
		struct vlan_hdr *vh;
2290

2291
		if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
2292
			return 0;
2293

2294 2295 2296
		vh = (struct vlan_hdr *)(skb->data + vlan_depth);
		type = vh->h_vlan_encapsulated_proto;
		vlan_depth += VLAN_HLEN;
2297 2298
	}

2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316
	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);

2317 2318 2319
	__skb_pull(skb, skb->mac_len);

	rcu_read_lock();
2320
	list_for_each_entry_rcu(ptype, &offload_base, list) {
2321
		if (ptype->type == type && ptype->callbacks.gso_segment) {
2322
			if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
2323 2324
				int err;

2325
				err = ptype->callbacks.gso_send_check(skb);
2326 2327 2328
				segs = ERR_PTR(err);
				if (err || skb_gso_ok(skb, features))
					break;
2329 2330
				__skb_push(skb, (skb->data -
						 skb_network_header(skb)));
2331
			}
2332
			segs = ptype->callbacks.gso_segment(skb, features);
2333 2334 2335 2336 2337
			break;
		}
	}
	rcu_read_unlock();

2338
	__skb_push(skb, skb->data - skb_mac_header(skb));
2339

2340 2341
	return segs;
}
2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 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
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);
	}

2379
	SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
2380 2381 2382 2383 2384
	skb_reset_mac_header(skb);
	skb_reset_mac_len(skb);

	return skb_mac_gso_segment(skb, features);
}
2385
EXPORT_SYMBOL(__skb_gso_segment);
2386

2387 2388 2389 2390 2391
/* Take action when hardware reception checksum errors are detected. */
#ifdef CONFIG_BUG
void netdev_rx_csum_fault(struct net_device *dev)
{
	if (net_ratelimit()) {
2392
		pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
2393 2394 2395 2396 2397 2398
		dump_stack();
	}
}
EXPORT_SYMBOL(netdev_rx_csum_fault);
#endif

L
Linus Torvalds 已提交
2399 2400 2401 2402 2403
/* 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
2404
static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
L
Linus Torvalds 已提交
2405
{
2406
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2407
	int i;
2408
	if (!(dev->features & NETIF_F_HIGHDMA)) {
2409 2410 2411
		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)))
2412
				return 1;
2413
		}
2414
	}
L
Linus Torvalds 已提交
2415

2416 2417
	if (PCI_DMA_BUS_IS_PHYS) {
		struct device *pdev = dev->dev.parent;
L
Linus Torvalds 已提交
2418

E
Eric Dumazet 已提交
2419 2420
		if (!pdev)
			return 0;
2421
		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
2422 2423
			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
			dma_addr_t addr = page_to_phys(skb_frag_page(frag));
2424 2425 2426 2427
			if (!pdev->dma_mask || addr + PAGE_SIZE - 1 > *pdev->dma_mask)
				return 1;
		}
	}
2428
#endif
L
Linus Torvalds 已提交
2429 2430 2431
	return 0;
}

2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457
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;

	do {
		struct sk_buff *nskb = skb->next;

		skb->next = nskb->next;
		nskb->next = NULL;
		kfree_skb(nskb);
	} while (skb->next);

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

/**
 *	dev_gso_segment - Perform emulated hardware segmentation on skb.
 *	@skb: buffer to segment
2458
 *	@features: device features as applicable to this skb
2459 2460 2461 2462
 *
 *	This function segments the given skb and stores the list of segments
 *	in skb->next.
 */
2463
static int dev_gso_segment(struct sk_buff *skb, netdev_features_t features)
2464 2465
{
	struct sk_buff *segs;
2466 2467 2468 2469 2470 2471

	segs = skb_gso_segment(skb, features);

	/* Verifying header integrity only. */
	if (!segs)
		return 0;
2472

2473
	if (IS_ERR(segs))
2474 2475 2476 2477 2478 2479 2480 2481 2482
		return PTR_ERR(segs);

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

	return 0;
}

2483
static netdev_features_t harmonize_features(struct sk_buff *skb,
2484
	netdev_features_t features)
2485
{
2486
	if (skb->ip_summed != CHECKSUM_NONE &&
2487
	    !can_checksum_protocol(features, skb_network_protocol(skb))) {
2488 2489 2490 2491 2492 2493 2494 2495
		features &= ~NETIF_F_ALL_CSUM;
	} else if (illegal_highdma(skb->dev, skb)) {
		features &= ~NETIF_F_SG;
	}

	return features;
}

2496
netdev_features_t netif_skb_features(struct sk_buff *skb)
2497 2498
{
	__be16 protocol = skb->protocol;
2499
	netdev_features_t features = skb->dev->features;
2500

2501 2502 2503
	if (skb_shinfo(skb)->gso_segs > skb->dev->gso_max_segs)
		features &= ~NETIF_F_GSO_MASK;

P
Patrick McHardy 已提交
2504
	if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD)) {
2505 2506
		struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
		protocol = veh->h_vlan_encapsulated_proto;
2507
	} else if (!vlan_tx_tag_present(skb)) {
2508
		return harmonize_features(skb, features);
2509
	}
2510

P
Patrick McHardy 已提交
2511 2512
	features &= (skb->dev->vlan_features | NETIF_F_HW_VLAN_CTAG_TX |
					       NETIF_F_HW_VLAN_STAG_TX);
2513

2514
	if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD))
2515
		features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
P
Patrick McHardy 已提交
2516 2517
				NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_CTAG_TX |
				NETIF_F_HW_VLAN_STAG_TX;
2518 2519

	return harmonize_features(skb, features);
2520
}
2521
EXPORT_SYMBOL(netif_skb_features);
2522

2523 2524 2525
/*
 * Returns true if either:
 *	1. skb has frag_list and the device doesn't support FRAGLIST, or
2526
 *	2. skb is fragmented and the device does not support SG.
2527 2528
 */
static inline int skb_needs_linearize(struct sk_buff *skb,
2529
				      netdev_features_t features)
2530
{
2531 2532 2533
	return skb_is_nonlinear(skb) &&
			((skb_has_frag_list(skb) &&
				!(features & NETIF_F_FRAGLIST)) ||
2534
			(skb_shinfo(skb)->nr_frags &&
2535
				!(features & NETIF_F_SG)));
2536 2537
}

2538 2539
int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
			struct netdev_queue *txq)
2540
{
2541
	const struct net_device_ops *ops = dev->netdev_ops;
2542
	int rc = NETDEV_TX_OK;
2543
	unsigned int skb_len;
2544

2545
	if (likely(!skb->next)) {
2546
		netdev_features_t features;
2547

2548
		/*
L
Lucas De Marchi 已提交
2549
		 * If device doesn't need skb->dst, release it right now while
2550 2551
		 * its hot in this cpu cache
		 */
E
Eric Dumazet 已提交
2552 2553 2554
		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
			skb_dst_drop(skb);

2555 2556
		features = netif_skb_features(skb);

2557
		if (vlan_tx_tag_present(skb) &&
2558 2559 2560
		    !vlan_hw_offload_capable(features, skb->vlan_proto)) {
			skb = __vlan_put_tag(skb, skb->vlan_proto,
					     vlan_tx_tag_get(skb));
2561 2562 2563 2564 2565 2566
			if (unlikely(!skb))
				goto out;

			skb->vlan_tci = 0;
		}

2567 2568 2569 2570 2571 2572 2573
		/* 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;

2574
		if (netif_needs_gso(skb, features)) {
2575
			if (unlikely(dev_gso_segment(skb, features)))
2576 2577 2578
				goto out_kfree_skb;
			if (skb->next)
				goto gso;
2579
		} else {
2580
			if (skb_needs_linearize(skb, features) &&
2581 2582 2583 2584 2585 2586 2587 2588
			    __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) {
2589 2590 2591 2592 2593 2594
				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));
2595
				if (!(features & NETIF_F_ALL_CSUM) &&
2596 2597 2598
				     skb_checksum_help(skb))
					goto out_kfree_skb;
			}
2599 2600
		}

2601 2602 2603
		if (!list_empty(&ptype_all))
			dev_queue_xmit_nit(skb, dev);

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

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

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

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

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

2637
out_kfree_gso_skb:
2638
	if (likely(skb->next == NULL)) {
2639
		skb->destructor = DEV_GSO_CB(skb)->destructor;
2640 2641 2642
		consume_skb(skb);
		return rc;
	}
2643 2644
out_kfree_skb:
	kfree_skb(skb);
2645
out:
2646
	return rc;
2647 2648
}

2649 2650 2651 2652 2653 2654 2655 2656 2657 2658
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)  {
2659
		unsigned int hdr_len;
2660
		u16 gso_segs = shinfo->gso_segs;
2661

2662 2663 2664 2665
		/* mac layer + network layer */
		hdr_len = skb_transport_header(skb) - skb_mac_header(skb);

		/* + transport layer */
2666 2667 2668 2669
		if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
			hdr_len += tcp_hdrlen(skb);
		else
			hdr_len += sizeof(struct udphdr);
2670 2671 2672 2673 2674 2675

		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;
2676 2677 2678
	}
}

2679 2680 2681 2682 2683
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
2684
	bool contended;
2685 2686
	int rc;

2687
	qdisc_pkt_len_init(skb);
E
Eric Dumazet 已提交
2688
	qdisc_calculate_pkt_len(skb, q);
2689 2690 2691 2692 2693 2694
	/*
	 * 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
2695
	contended = qdisc_is_running(q);
2696 2697 2698
	if (unlikely(contended))
		spin_lock(&q->busylock);

2699 2700 2701 2702 2703
	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) &&
2704
		   qdisc_run_begin(q)) {
2705 2706 2707 2708 2709
		/*
		 * 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
2710 2711
		if (!(dev->priv_flags & IFF_XMIT_DST_RELEASE))
			skb_dst_force(skb);
2712 2713 2714

		qdisc_bstats_update(q, skb);

2715 2716 2717 2718 2719
		if (sch_direct_xmit(skb, q, dev, txq, root_lock)) {
			if (unlikely(contended)) {
				spin_unlock(&q->busylock);
				contended = false;
			}
2720
			__qdisc_run(q);
2721
		} else
2722
			qdisc_run_end(q);
2723 2724 2725

		rc = NET_XMIT_SUCCESS;
	} else {
E
Eric Dumazet 已提交
2726
		skb_dst_force(skb);
E
Eric Dumazet 已提交
2727
		rc = q->enqueue(skb, q) & NET_XMIT_MASK;
2728 2729 2730 2731 2732 2733 2734
		if (qdisc_run_begin(q)) {
			if (unlikely(contended)) {
				spin_unlock(&q->busylock);
				contended = false;
			}
			__qdisc_run(q);
		}
2735 2736
	}
	spin_unlock(root_lock);
2737 2738
	if (unlikely(contended))
		spin_unlock(&q->busylock);
2739 2740 2741
	return rc;
}

2742 2743 2744
#if IS_ENABLED(CONFIG_NETPRIO_CGROUP)
static void skb_update_prio(struct sk_buff *skb)
{
I
Igor Maravic 已提交
2745
	struct netprio_map *map = rcu_dereference_bh(skb->dev->priomap);
2746

2747 2748 2749 2750 2751 2752
	if (!skb->priority && skb->sk && map) {
		unsigned int prioidx = skb->sk->sk_cgrp_prioidx;

		if (prioidx < map->priomap_len)
			skb->priority = map->priomap[prioidx];
	}
2753 2754 2755 2756 2757
}
#else
#define skb_update_prio(skb)
#endif

2758
static DEFINE_PER_CPU(int, xmit_recursion);
2759
#define RECURSION_LIMIT 10
2760

2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777
/**
 *	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);

2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802
/**
 *	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
2803 2804 2805
int dev_queue_xmit(struct sk_buff *skb)
{
	struct net_device *dev = skb->dev;
2806
	struct netdev_queue *txq;
L
Linus Torvalds 已提交
2807 2808 2809
	struct Qdisc *q;
	int rc = -ENOMEM;

2810 2811
	skb_reset_mac_header(skb);

2812 2813
	/* Disable soft irqs for various locks below. Also
	 * stops preemption for RCU.
L
Linus Torvalds 已提交
2814
	 */
2815
	rcu_read_lock_bh();
L
Linus Torvalds 已提交
2816

2817 2818
	skb_update_prio(skb);

2819
	txq = netdev_pick_tx(dev, skb);
2820
	q = rcu_dereference_bh(txq->qdisc);
2821

L
Linus Torvalds 已提交
2822
#ifdef CONFIG_NET_CLS_ACT
E
Eric Dumazet 已提交
2823
	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_EGRESS);
L
Linus Torvalds 已提交
2824
#endif
2825
	trace_net_dev_queue(skb);
L
Linus Torvalds 已提交
2826
	if (q->enqueue) {
2827
		rc = __dev_xmit_skb(skb, q, dev, txq);
2828
		goto out;
L
Linus Torvalds 已提交
2829 2830 2831 2832 2833
	}

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

H
Herbert Xu 已提交
2834 2835
	   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
2836 2837 2838 2839 2840 2841 2842 2843 2844 2845
	   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 */

2846
		if (txq->xmit_lock_owner != cpu) {
L
Linus Torvalds 已提交
2847

2848 2849 2850
			if (__this_cpu_read(xmit_recursion) > RECURSION_LIMIT)
				goto recursion_alert;

2851
			HARD_TX_LOCK(dev, txq, cpu);
L
Linus Torvalds 已提交
2852

2853
			if (!netif_xmit_stopped(txq)) {
2854
				__this_cpu_inc(xmit_recursion);
2855
				rc = dev_hard_start_xmit(skb, dev, txq);
2856
				__this_cpu_dec(xmit_recursion);
2857
				if (dev_xmit_complete(rc)) {
2858
					HARD_TX_UNLOCK(dev, txq);
L
Linus Torvalds 已提交
2859 2860 2861
					goto out;
				}
			}
2862
			HARD_TX_UNLOCK(dev, txq);
2863 2864
			net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
					     dev->name);
L
Linus Torvalds 已提交
2865 2866
		} else {
			/* Recursion is detected! It is possible,
2867 2868 2869
			 * unfortunately
			 */
recursion_alert:
2870 2871
			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
					     dev->name);
L
Linus Torvalds 已提交
2872 2873 2874 2875
		}
	}

	rc = -ENETDOWN;
2876
	rcu_read_unlock_bh();
L
Linus Torvalds 已提交
2877 2878 2879 2880

	kfree_skb(skb);
	return rc;
out:
2881
	rcu_read_unlock_bh();
L
Linus Torvalds 已提交
2882 2883
	return rc;
}
E
Eric Dumazet 已提交
2884
EXPORT_SYMBOL(dev_queue_xmit);
L
Linus Torvalds 已提交
2885 2886 2887 2888 2889 2890


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

2891
int netdev_max_backlog __read_mostly = 1000;
E
Eric Dumazet 已提交
2892 2893
EXPORT_SYMBOL(netdev_max_backlog);

E
Eric Dumazet 已提交
2894
int netdev_tstamp_prequeue __read_mostly = 1;
2895 2896
int netdev_budget __read_mostly = 300;
int weight_p __read_mostly = 64;            /* old backlog weight */
L
Linus Torvalds 已提交
2897

E
Eric Dumazet 已提交
2898 2899 2900 2901 2902 2903 2904 2905
/* 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);
}

2906 2907 2908
#ifdef CONFIG_RPS

/* One global table that all flow-based protocols share. */
E
Eric Dumazet 已提交
2909
struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
2910 2911
EXPORT_SYMBOL(rps_sock_flow_table);

2912
struct static_key rps_needed __read_mostly;
2913

2914 2915 2916 2917
static struct rps_dev_flow *
set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
	    struct rps_dev_flow *rflow, u16 next_cpu)
{
2918
	if (next_cpu != RPS_NO_CPU) {
2919 2920 2921 2922 2923 2924 2925 2926 2927
#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? */
2928 2929
		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
		    !(dev->features & NETIF_F_NTUPLE))
2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951
			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 =
2952
			per_cpu(softnet_data, next_cpu).input_queue_head;
2953 2954
	}

2955
	rflow->cpu = next_cpu;
2956 2957 2958
	return rflow;
}

2959 2960 2961 2962 2963 2964 2965 2966 2967
/*
 * 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
2968
	struct rps_map *map;
2969 2970 2971 2972 2973 2974 2975
	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);
2976 2977 2978 2979 2980
		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);
2981 2982 2983 2984 2985 2986
			goto done;
		}
		rxqueue = dev->_rx + index;
	} else
		rxqueue = dev->_rx;

E
Eric Dumazet 已提交
2987 2988
	map = rcu_dereference(rxqueue->rps_map);
	if (map) {
2989
		if (map->len == 1 &&
2990
		    !rcu_access_pointer(rxqueue->rps_flow_table)) {
2991 2992 2993 2994 2995
			tcpu = map->cpus[0];
			if (cpu_online(tcpu))
				cpu = tcpu;
			goto done;
		}
2996
	} else if (!rcu_access_pointer(rxqueue->rps_flow_table)) {
2997
		goto done;
2998
	}
2999

3000
	skb_reset_network_header(skb);
3001 3002 3003
	if (!skb_get_rxhash(skb))
		goto done;

T
Tom Herbert 已提交
3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029
	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 -
3030 3031
		      rflow->last_qtail)) >= 0)) {
			tcpu = next_cpu;
3032
			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
3033
		}
3034

T
Tom Herbert 已提交
3035 3036 3037 3038 3039 3040 3041
		if (tcpu != RPS_NO_CPU && cpu_online(tcpu)) {
			*rflowp = rflow;
			cpu = tcpu;
			goto done;
		}
	}

T
Tom Herbert 已提交
3042
	if (map) {
T
Tom Herbert 已提交
3043
		tcpu = map->cpus[((u64) skb->rxhash * map->len) >> 32];
T
Tom Herbert 已提交
3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054

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

done:
	return cpu;
}

3055 3056 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
#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
3095
/* Called from hardirq (IPI) context */
E
Eric Dumazet 已提交
3096
static void rps_trigger_softirq(void *data)
T
Tom Herbert 已提交
3097
{
E
Eric Dumazet 已提交
3098 3099
	struct softnet_data *sd = data;

E
Eric Dumazet 已提交
3100
	____napi_schedule(sd, &sd->backlog);
C
Changli Gao 已提交
3101
	sd->received_rps++;
T
Tom Herbert 已提交
3102
}
E
Eric Dumazet 已提交
3103

T
Tom Herbert 已提交
3104
#endif /* CONFIG_RPS */
T
Tom Herbert 已提交
3105

E
Eric Dumazet 已提交
3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126
/*
 * 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;
}

3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166
#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) {
		new_flow = skb_get_rxhash(skb) & (fl->num_buckets - 1);
		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
3167 3168 3169 3170
/*
 * 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
3171 3172
static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
			      unsigned int *qtail)
T
Tom Herbert 已提交
3173
{
E
Eric Dumazet 已提交
3174
	struct softnet_data *sd;
T
Tom Herbert 已提交
3175
	unsigned long flags;
3176
	unsigned int qlen;
T
Tom Herbert 已提交
3177

E
Eric Dumazet 已提交
3178
	sd = &per_cpu(softnet_data, cpu);
T
Tom Herbert 已提交
3179 3180 3181

	local_irq_save(flags);

E
Eric Dumazet 已提交
3182
	rps_lock(sd);
3183 3184
	qlen = skb_queue_len(&sd->input_pkt_queue);
	if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) {
3185
		if (skb_queue_len(&sd->input_pkt_queue)) {
T
Tom Herbert 已提交
3186
enqueue:
E
Eric Dumazet 已提交
3187
			__skb_queue_tail(&sd->input_pkt_queue, skb);
3188
			input_queue_tail_incr_save(sd, qtail);
E
Eric Dumazet 已提交
3189
			rps_unlock(sd);
3190
			local_irq_restore(flags);
T
Tom Herbert 已提交
3191 3192 3193
			return NET_RX_SUCCESS;
		}

3194 3195 3196 3197
		/* 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
3198
			if (!rps_ipi_queued(sd))
E
Eric Dumazet 已提交
3199
				____napi_schedule(sd, &sd->backlog);
T
Tom Herbert 已提交
3200 3201 3202 3203
		}
		goto enqueue;
	}

C
Changli Gao 已提交
3204
	sd->dropped++;
E
Eric Dumazet 已提交
3205
	rps_unlock(sd);
T
Tom Herbert 已提交
3206 3207 3208

	local_irq_restore(flags);

3209
	atomic_long_inc(&skb->dev->rx_dropped);
T
Tom Herbert 已提交
3210 3211 3212
	kfree_skb(skb);
	return NET_RX_DROP;
}
L
Linus Torvalds 已提交
3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230

/**
 *	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)
{
3231
	int ret;
L
Linus Torvalds 已提交
3232 3233 3234 3235 3236

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

3237
	net_timestamp_check(netdev_tstamp_prequeue, skb);
L
Linus Torvalds 已提交
3238

3239
	trace_netif_rx(skb);
E
Eric Dumazet 已提交
3240
#ifdef CONFIG_RPS
3241
	if (static_key_false(&rps_needed)) {
T
Tom Herbert 已提交
3242
		struct rps_dev_flow voidflow, *rflow = &voidflow;
3243 3244
		int cpu;

3245
		preempt_disable();
3246
		rcu_read_lock();
T
Tom Herbert 已提交
3247 3248

		cpu = get_rps_cpu(skb->dev, skb, &rflow);
3249 3250
		if (cpu < 0)
			cpu = smp_processor_id();
T
Tom Herbert 已提交
3251 3252 3253

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

3254
		rcu_read_unlock();
3255
		preempt_enable();
3256 3257
	} else
#endif
T
Tom Herbert 已提交
3258 3259 3260 3261 3262
	{
		unsigned int qtail;
		ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
		put_cpu();
	}
3263
	return ret;
L
Linus Torvalds 已提交
3264
}
E
Eric Dumazet 已提交
3265
EXPORT_SYMBOL(netif_rx);
L
Linus Torvalds 已提交
3266 3267 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

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;

3297
			WARN_ON(atomic_read(&skb->users));
3298
			trace_kfree_skb(skb, net_tx_action);
L
Linus Torvalds 已提交
3299 3300 3301 3302 3303
			__kfree_skb(skb);
		}
	}

	if (sd->output_queue) {
3304
		struct Qdisc *head;
L
Linus Torvalds 已提交
3305 3306 3307 3308

		local_irq_disable();
		head = sd->output_queue;
		sd->output_queue = NULL;
3309
		sd->output_queue_tailp = &sd->output_queue;
L
Linus Torvalds 已提交
3310 3311 3312
		local_irq_enable();

		while (head) {
3313 3314 3315
			struct Qdisc *q = head;
			spinlock_t *root_lock;

L
Linus Torvalds 已提交
3316 3317
			head = head->next_sched;

3318
			root_lock = qdisc_lock(q);
3319
			if (spin_trylock(root_lock)) {
3320 3321 3322
				smp_mb__before_clear_bit();
				clear_bit(__QDISC_STATE_SCHED,
					  &q->state);
3323 3324
				qdisc_run(q);
				spin_unlock(root_lock);
L
Linus Torvalds 已提交
3325
			} else {
3326
				if (!test_bit(__QDISC_STATE_DEACTIVATED,
3327
					      &q->state)) {
3328
					__netif_reschedule(q);
3329 3330 3331 3332 3333
				} else {
					smp_mb__before_clear_bit();
					clear_bit(__QDISC_STATE_SCHED,
						  &q->state);
				}
L
Linus Torvalds 已提交
3334 3335 3336 3337 3338
			}
		}
	}
}

3339 3340
#if (defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)) && \
    (defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE))
3341 3342 3343
/* This hook is defined here for ATM LANE */
int (*br_fdb_test_addr_hook)(struct net_device *dev,
			     unsigned char *addr) __read_mostly;
3344
EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
3345
#endif
L
Linus Torvalds 已提交
3346 3347 3348 3349 3350 3351

#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
3352 3353
 * 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
3354 3355
 *
 */
3356
static int ing_filter(struct sk_buff *skb, struct netdev_queue *rxq)
L
Linus Torvalds 已提交
3357 3358
{
	struct net_device *dev = skb->dev;
3359
	u32 ttl = G_TC_RTTL(skb->tc_verd);
3360 3361
	int result = TC_ACT_OK;
	struct Qdisc *q;
3362

3363
	if (unlikely(MAX_RED_LOOP < ttl++)) {
3364 3365
		net_warn_ratelimited("Redir loop detected Dropping packet (%d->%d)\n",
				     skb->skb_iif, dev->ifindex);
3366 3367
		return TC_ACT_SHOT;
	}
L
Linus Torvalds 已提交
3368

3369 3370
	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
3371

3372
	q = rxq->qdisc;
3373
	if (q != &noop_qdisc) {
3374
		spin_lock(qdisc_lock(q));
3375 3376
		if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))
			result = qdisc_enqueue_root(skb, q);
3377 3378
		spin_unlock(qdisc_lock(q));
	}
3379 3380 3381

	return result;
}
3382

3383 3384 3385 3386
static inline struct sk_buff *handle_ing(struct sk_buff *skb,
					 struct packet_type **pt_prev,
					 int *ret, struct net_device *orig_dev)
{
3387 3388 3389
	struct netdev_queue *rxq = rcu_dereference(skb->dev->ingress_queue);

	if (!rxq || rxq->qdisc == &noop_qdisc)
3390
		goto out;
L
Linus Torvalds 已提交
3391

3392 3393 3394
	if (*pt_prev) {
		*ret = deliver_skb(skb, *pt_prev, orig_dev);
		*pt_prev = NULL;
L
Linus Torvalds 已提交
3395 3396
	}

3397
	switch (ing_filter(skb, rxq)) {
3398 3399 3400 3401 3402 3403 3404 3405 3406
	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
3407 3408 3409
}
#endif

3410 3411 3412 3413
/**
 *	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
3414
 *	@rx_handler_data: data pointer that is used by rx handler
3415 3416 3417 3418 3419 3420
 *
 *	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.
3421 3422
 *
 *	For a general description of rx_handler, see enum rx_handler_result.
3423 3424
 */
int netdev_rx_handler_register(struct net_device *dev,
J
Jiri Pirko 已提交
3425 3426
			       rx_handler_func_t *rx_handler,
			       void *rx_handler_data)
3427 3428 3429 3430 3431 3432
{
	ASSERT_RTNL();

	if (dev->rx_handler)
		return -EBUSY;

3433
	/* Note: rx_handler_data must be set before rx_handler */
J
Jiri Pirko 已提交
3434
	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
3435 3436 3437 3438 3439 3440 3441 3442 3443 3444
	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
3445
 *	Unregister a receive handler from a device.
3446 3447 3448 3449 3450 3451 3452
 *
 *	The caller must hold the rtnl_mutex.
 */
void netdev_rx_handler_unregister(struct net_device *dev)
{

	ASSERT_RTNL();
3453
	RCU_INIT_POINTER(dev->rx_handler, NULL);
3454 3455 3456 3457 3458
	/* 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();
3459
	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
3460 3461 3462
}
EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);

3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473
/*
 * 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
3474
	case __constant_htons(ETH_P_8021AD):
3475 3476 3477 3478 3479 3480
		return true;
	default:
		return false;
	}
}

3481
static int __netif_receive_skb_core(struct sk_buff *skb, bool pfmemalloc)
L
Linus Torvalds 已提交
3482 3483
{
	struct packet_type *ptype, *pt_prev;
3484
	rx_handler_func_t *rx_handler;
D
David S. Miller 已提交
3485
	struct net_device *orig_dev;
3486
	struct net_device *null_or_dev;
3487
	bool deliver_exact = false;
L
Linus Torvalds 已提交
3488
	int ret = NET_RX_DROP;
A
Al Viro 已提交
3489
	__be16 type;
L
Linus Torvalds 已提交
3490

3491
	net_timestamp_check(!netdev_tstamp_prequeue, skb);
3492

3493
	trace_netif_receive_skb(skb);
3494

L
Linus Torvalds 已提交
3495
	/* if we've gotten here through NAPI, check netpoll */
3496
	if (netpoll_receive_skb(skb))
3497
		goto out;
L
Linus Torvalds 已提交
3498

J
Joe Eykholt 已提交
3499
	orig_dev = skb->dev;
3500

3501
	skb_reset_network_header(skb);
3502 3503
	if (!skb_transport_header_was_set(skb))
		skb_reset_transport_header(skb);
3504
	skb_reset_mac_len(skb);
L
Linus Torvalds 已提交
3505 3506 3507 3508 3509

	pt_prev = NULL;

	rcu_read_lock();

3510
another_round:
3511
	skb->skb_iif = skb->dev->ifindex;
3512 3513 3514

	__this_cpu_inc(softnet_data.processed);

P
Patrick McHardy 已提交
3515 3516
	if (skb->protocol == cpu_to_be16(ETH_P_8021Q) ||
	    skb->protocol == cpu_to_be16(ETH_P_8021AD)) {
3517 3518
		skb = vlan_untag(skb);
		if (unlikely(!skb))
3519
			goto unlock;
3520 3521
	}

L
Linus Torvalds 已提交
3522 3523 3524 3525 3526 3527 3528
#ifdef CONFIG_NET_CLS_ACT
	if (skb->tc_verd & TC_NCLS) {
		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
		goto ncls;
	}
#endif

3529
	if (pfmemalloc)
3530 3531
		goto skip_taps;

L
Linus Torvalds 已提交
3532
	list_for_each_entry_rcu(ptype, &ptype_all, list) {
3533
		if (!ptype->dev || ptype->dev == skb->dev) {
3534
			if (pt_prev)
D
David S. Miller 已提交
3535
				ret = deliver_skb(skb, pt_prev, orig_dev);
L
Linus Torvalds 已提交
3536 3537 3538 3539
			pt_prev = ptype;
		}
	}

3540
skip_taps:
L
Linus Torvalds 已提交
3541
#ifdef CONFIG_NET_CLS_ACT
3542 3543
	skb = handle_ing(skb, &pt_prev, &ret, orig_dev);
	if (!skb)
3544
		goto unlock;
L
Linus Torvalds 已提交
3545 3546 3547
ncls:
#endif

3548
	if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
3549 3550
		goto drop;

3551 3552 3553 3554 3555
	if (vlan_tx_tag_present(skb)) {
		if (pt_prev) {
			ret = deliver_skb(skb, pt_prev, orig_dev);
			pt_prev = NULL;
		}
3556
		if (vlan_do_receive(&skb))
3557 3558
			goto another_round;
		else if (unlikely(!skb))
3559
			goto unlock;
3560 3561
	}

3562
	rx_handler = rcu_dereference(skb->dev->rx_handler);
3563 3564 3565 3566 3567
	if (rx_handler) {
		if (pt_prev) {
			ret = deliver_skb(skb, pt_prev, orig_dev);
			pt_prev = NULL;
		}
3568 3569
		switch (rx_handler(&skb)) {
		case RX_HANDLER_CONSUMED:
3570
			ret = NET_RX_SUCCESS;
3571
			goto unlock;
3572
		case RX_HANDLER_ANOTHER:
3573
			goto another_round;
3574 3575 3576 3577 3578 3579 3580
		case RX_HANDLER_EXACT:
			deliver_exact = true;
		case RX_HANDLER_PASS:
			break;
		default:
			BUG();
		}
3581
	}
L
Linus Torvalds 已提交
3582

E
Eric Dumazet 已提交
3583 3584 3585 3586 3587 3588 3589 3590 3591
	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;
	}
3592

3593
	/* deliver only exact match when indicated */
3594
	null_or_dev = deliver_exact ? skb->dev : NULL;
3595

L
Linus Torvalds 已提交
3596
	type = skb->protocol;
3597 3598
	list_for_each_entry_rcu(ptype,
			&ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
3599
		if (ptype->type == type &&
3600 3601
		    (ptype->dev == null_or_dev || ptype->dev == skb->dev ||
		     ptype->dev == orig_dev)) {
3602
			if (pt_prev)
D
David S. Miller 已提交
3603
				ret = deliver_skb(skb, pt_prev, orig_dev);
L
Linus Torvalds 已提交
3604 3605 3606 3607 3608
			pt_prev = ptype;
		}
	}

	if (pt_prev) {
3609
		if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
3610
			goto drop;
3611 3612
		else
			ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
L
Linus Torvalds 已提交
3613
	} else {
3614
drop:
3615
		atomic_long_inc(&skb->dev->rx_dropped);
L
Linus Torvalds 已提交
3616 3617 3618 3619 3620 3621 3622
		kfree_skb(skb);
		/* Jamal, now you will not able to escape explaining
		 * me how you were going to use this. :-)
		 */
		ret = NET_RX_DROP;
	}

3623
unlock:
L
Linus Torvalds 已提交
3624
	rcu_read_unlock();
3625
out:
3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650
	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
3651 3652
	return ret;
}
T
Tom Herbert 已提交
3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670

/**
 *	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)
{
3671
	net_timestamp_check(netdev_tstamp_prequeue, skb);
E
Eric Dumazet 已提交
3672

3673 3674 3675
	if (skb_defer_rx_timestamp(skb))
		return NET_RX_SUCCESS;

E
Eric Dumazet 已提交
3676
#ifdef CONFIG_RPS
3677
	if (static_key_false(&rps_needed)) {
E
Eric Dumazet 已提交
3678 3679
		struct rps_dev_flow voidflow, *rflow = &voidflow;
		int cpu, ret;
T
Tom Herbert 已提交
3680

E
Eric Dumazet 已提交
3681 3682 3683
		rcu_read_lock();

		cpu = get_rps_cpu(skb->dev, skb, &rflow);
T
Tom Herbert 已提交
3684

E
Eric Dumazet 已提交
3685 3686 3687
		if (cpu >= 0) {
			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
			rcu_read_unlock();
3688
			return ret;
E
Eric Dumazet 已提交
3689
		}
3690
		rcu_read_unlock();
T
Tom Herbert 已提交
3691
	}
3692
#endif
3693
	return __netif_receive_skb(skb);
T
Tom Herbert 已提交
3694
}
E
Eric Dumazet 已提交
3695
EXPORT_SYMBOL(netif_receive_skb);
L
Linus Torvalds 已提交
3696

E
Eric Dumazet 已提交
3697 3698 3699
/* Network device is going away, flush any packets still pending
 * Called with irqs disabled.
 */
3700
static void flush_backlog(void *arg)
3701
{
3702
	struct net_device *dev = arg;
E
Eric Dumazet 已提交
3703
	struct softnet_data *sd = &__get_cpu_var(softnet_data);
3704 3705
	struct sk_buff *skb, *tmp;

E
Eric Dumazet 已提交
3706
	rps_lock(sd);
3707
	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
3708
		if (skb->dev == dev) {
E
Eric Dumazet 已提交
3709
			__skb_unlink(skb, &sd->input_pkt_queue);
3710
			kfree_skb(skb);
3711
			input_queue_head_incr(sd);
3712
		}
3713
	}
E
Eric Dumazet 已提交
3714
	rps_unlock(sd);
3715 3716 3717 3718 3719

	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
		if (skb->dev == dev) {
			__skb_unlink(skb, &sd->process_queue);
			kfree_skb(skb);
3720
			input_queue_head_incr(sd);
3721 3722
		}
	}
3723 3724
}

3725 3726
static int napi_gro_complete(struct sk_buff *skb)
{
3727
	struct packet_offload *ptype;
3728
	__be16 type = skb->protocol;
3729
	struct list_head *head = &offload_base;
3730 3731
	int err = -ENOENT;

3732 3733
	BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));

3734 3735
	if (NAPI_GRO_CB(skb)->count == 1) {
		skb_shinfo(skb)->gso_size = 0;
3736
		goto out;
3737
	}
3738 3739 3740

	rcu_read_lock();
	list_for_each_entry_rcu(ptype, head, list) {
3741
		if (ptype->type != type || !ptype->callbacks.gro_complete)
3742 3743
			continue;

3744
		err = ptype->callbacks.gro_complete(skb);
3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758
		break;
	}
	rcu_read_unlock();

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

out:
	return netif_receive_skb(skb);
}

3759 3760 3761 3762 3763
/* 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)
3764
{
3765
	struct sk_buff *skb, *prev = NULL;
3766

3767 3768 3769 3770 3771 3772 3773
	/* 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) {
3774
		skb->next = NULL;
3775 3776 3777 3778 3779

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

		prev = skb->prev;
3780
		napi_gro_complete(skb);
3781
		napi->gro_count--;
3782 3783 3784 3785
	}

	napi->gro_list = NULL;
}
E
Eric Dumazet 已提交
3786
EXPORT_SYMBOL(napi_gro_flush);
3787

E
Eric Dumazet 已提交
3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809
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;
	}
}

R
Rami Rosen 已提交
3810
static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3811 3812
{
	struct sk_buff **pp = NULL;
3813
	struct packet_offload *ptype;
3814
	__be16 type = skb->protocol;
3815
	struct list_head *head = &offload_base;
H
Herbert Xu 已提交
3816
	int same_flow;
3817
	enum gro_result ret;
3818

3819
	if (!(skb->dev->features & NETIF_F_GRO) || netpoll_rx_on(skb))
3820 3821
		goto normal;

3822
	if (skb_is_gso(skb) || skb_has_frag_list(skb))
3823 3824
		goto normal;

E
Eric Dumazet 已提交
3825 3826
	gro_list_prepare(napi, skb);

3827 3828
	rcu_read_lock();
	list_for_each_entry_rcu(ptype, head, list) {
3829
		if (ptype->type != type || !ptype->callbacks.gro_receive)
3830 3831
			continue;

3832
		skb_set_network_header(skb, skb_gro_offset(skb));
3833
		skb_reset_mac_len(skb);
3834 3835
		NAPI_GRO_CB(skb)->same_flow = 0;
		NAPI_GRO_CB(skb)->flush = 0;
H
Herbert Xu 已提交
3836
		NAPI_GRO_CB(skb)->free = 0;
3837

3838
		pp = ptype->callbacks.gro_receive(&napi->gro_list, skb);
3839 3840 3841 3842 3843 3844 3845
		break;
	}
	rcu_read_unlock();

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

H
Herbert Xu 已提交
3846
	same_flow = NAPI_GRO_CB(skb)->same_flow;
3847
	ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
H
Herbert Xu 已提交
3848

3849 3850 3851 3852 3853 3854
	if (pp) {
		struct sk_buff *nskb = *pp;

		*pp = nskb->next;
		nskb->next = NULL;
		napi_gro_complete(nskb);
3855
		napi->gro_count--;
3856 3857
	}

H
Herbert Xu 已提交
3858
	if (same_flow)
3859 3860
		goto ok;

3861
	if (NAPI_GRO_CB(skb)->flush || napi->gro_count >= MAX_GRO_SKBS)
3862 3863
		goto normal;

3864
	napi->gro_count++;
3865
	NAPI_GRO_CB(skb)->count = 1;
3866
	NAPI_GRO_CB(skb)->age = jiffies;
3867
	skb_shinfo(skb)->gso_size = skb_gro_len(skb);
3868 3869
	skb->next = napi->gro_list;
	napi->gro_list = skb;
3870
	ret = GRO_HELD;
3871

3872
pull:
H
Herbert Xu 已提交
3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883
	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
3884
		skb_frag_size_sub(&skb_shinfo(skb)->frags[0], grow);
H
Herbert Xu 已提交
3885

E
Eric Dumazet 已提交
3886
		if (unlikely(!skb_frag_size(&skb_shinfo(skb)->frags[0]))) {
3887
			skb_frag_unref(skb, 0);
H
Herbert Xu 已提交
3888 3889
			memmove(skb_shinfo(skb)->frags,
				skb_shinfo(skb)->frags + 1,
3890
				--skb_shinfo(skb)->nr_frags * sizeof(skb_frag_t));
H
Herbert Xu 已提交
3891
		}
3892 3893
	}

3894
ok:
3895
	return ret;
3896 3897

normal:
3898 3899
	ret = GRO_NORMAL;
	goto pull;
H
Herbert Xu 已提交
3900
}
3901

H
Herbert Xu 已提交
3902

R
Rami Rosen 已提交
3903
static gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
H
Herbert Xu 已提交
3904
{
3905 3906
	switch (ret) {
	case GRO_NORMAL:
3907 3908 3909
		if (netif_receive_skb(skb))
			ret = GRO_DROP;
		break;
H
Herbert Xu 已提交
3910

3911
	case GRO_DROP:
H
Herbert Xu 已提交
3912 3913
		kfree_skb(skb);
		break;
3914

3915
	case GRO_MERGED_FREE:
3916 3917 3918 3919
		if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
			kmem_cache_free(skbuff_head_cache, skb);
		else
			__kfree_skb(skb);
3920 3921
		break;

3922 3923 3924
	case GRO_HELD:
	case GRO_MERGED:
		break;
H
Herbert Xu 已提交
3925 3926
	}

3927
	return ret;
3928 3929
}

3930
static void skb_gro_reset_offset(struct sk_buff *skb)
3931
{
3932 3933 3934
	const struct skb_shared_info *pinfo = skb_shinfo(skb);
	const skb_frag_t *frag0 = &pinfo->frags[0];

3935 3936
	NAPI_GRO_CB(skb)->data_offset = 0;
	NAPI_GRO_CB(skb)->frag0 = NULL;
3937
	NAPI_GRO_CB(skb)->frag0_len = 0;
3938

3939
	if (skb_mac_header(skb) == skb_tail_pointer(skb) &&
3940 3941 3942 3943
	    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);
3944
	}
3945 3946
}

3947
gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3948
{
3949 3950
	skb_gro_reset_offset(skb);

E
Eric Dumazet 已提交
3951
	return napi_skb_finish(dev_gro_receive(napi, skb), skb);
3952 3953 3954
}
EXPORT_SYMBOL(napi_gro_receive);

S
stephen hemminger 已提交
3955
static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
3956 3957
{
	__skb_pull(skb, skb_headlen(skb));
3958 3959
	/* restore the reserve we had after netdev_alloc_skb_ip_align() */
	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
3960
	skb->vlan_tci = 0;
H
Herbert Xu 已提交
3961
	skb->dev = napi->dev;
A
Andy Gospodarek 已提交
3962
	skb->skb_iif = 0;
3963 3964 3965 3966

	napi->skb = skb;
}

3967
struct sk_buff *napi_get_frags(struct napi_struct *napi)
H
Herbert Xu 已提交
3968 3969 3970 3971
{
	struct sk_buff *skb = napi->skb;

	if (!skb) {
3972 3973 3974
		skb = netdev_alloc_skb_ip_align(napi->dev, GRO_MAX_HEAD);
		if (skb)
			napi->skb = skb;
3975
	}
3976 3977
	return skb;
}
3978
EXPORT_SYMBOL(napi_get_frags);
3979

R
Rami Rosen 已提交
3980
static gro_result_t napi_frags_finish(struct napi_struct *napi, struct sk_buff *skb,
3981
			       gro_result_t ret)
3982
{
3983 3984
	switch (ret) {
	case GRO_NORMAL:
3985
	case GRO_HELD:
3986
		skb->protocol = eth_type_trans(skb, skb->dev);
3987

3988 3989 3990 3991
		if (ret == GRO_HELD)
			skb_gro_pull(skb, -ETH_HLEN);
		else if (netif_receive_skb(skb))
			ret = GRO_DROP;
3992
		break;
H
Herbert Xu 已提交
3993

3994 3995 3996 3997
	case GRO_DROP:
	case GRO_MERGED_FREE:
		napi_reuse_skb(napi, skb);
		break;
3998 3999 4000

	case GRO_MERGED:
		break;
4001
	}
H
Herbert Xu 已提交
4002

4003
	return ret;
H
Herbert Xu 已提交
4004
}
4005

E
Eric Dumazet 已提交
4006
static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
4007 4008 4009
{
	struct sk_buff *skb = napi->skb;
	struct ethhdr *eth;
4010 4011
	unsigned int hlen;
	unsigned int off;
4012 4013 4014 4015 4016 4017

	napi->skb = NULL;

	skb_reset_mac_header(skb);
	skb_gro_reset_offset(skb);

4018 4019 4020 4021 4022 4023 4024 4025 4026 4027
	off = skb_gro_offset(skb);
	hlen = off + sizeof(*eth);
	eth = skb_gro_header_fast(skb, off);
	if (skb_gro_header_hard(skb, hlen)) {
		eth = skb_gro_header_slow(skb, hlen, off);
		if (unlikely(!eth)) {
			napi_reuse_skb(napi, skb);
			skb = NULL;
			goto out;
		}
4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041
	}

	skb_gro_pull(skb, sizeof(*eth));

	/*
	 * This works because the only protocols we care about don't require
	 * special handling.  We'll fix it up properly at the end.
	 */
	skb->protocol = eth->h_proto;

out:
	return skb;
}

4042
gro_result_t napi_gro_frags(struct napi_struct *napi)
4043
{
4044
	struct sk_buff *skb = napi_frags_skb(napi);
4045 4046

	if (!skb)
4047
		return GRO_DROP;
4048

E
Eric Dumazet 已提交
4049
	return napi_frags_finish(napi, skb, dev_gro_receive(napi, skb));
4050
}
H
Herbert Xu 已提交
4051 4052
EXPORT_SYMBOL(napi_gro_frags);

4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080
/*
 * net_rps_action sends any pending IPI's for rps.
 * 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();
}

4081
static int process_backlog(struct napi_struct *napi, int quota)
L
Linus Torvalds 已提交
4082 4083
{
	int work = 0;
E
Eric Dumazet 已提交
4084
	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
L
Linus Torvalds 已提交
4085

4086 4087 4088 4089 4090 4091 4092 4093 4094
#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
4095
	napi->weight = weight_p;
4096 4097
	local_irq_disable();
	while (work < quota) {
L
Linus Torvalds 已提交
4098
		struct sk_buff *skb;
4099 4100 4101 4102 4103 4104
		unsigned int qlen;

		while ((skb = __skb_dequeue(&sd->process_queue))) {
			local_irq_enable();
			__netif_receive_skb(skb);
			local_irq_disable();
4105 4106 4107 4108 4109
			input_queue_head_incr(sd);
			if (++work >= quota) {
				local_irq_enable();
				return work;
			}
4110
		}
L
Linus Torvalds 已提交
4111

E
Eric Dumazet 已提交
4112
		rps_lock(sd);
4113
		qlen = skb_queue_len(&sd->input_pkt_queue);
4114
		if (qlen)
4115 4116
			skb_queue_splice_tail_init(&sd->input_pkt_queue,
						   &sd->process_queue);
4117

4118
		if (qlen < quota - work) {
E
Eric Dumazet 已提交
4119 4120 4121 4122 4123 4124 4125 4126 4127 4128
			/*
			 * 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;

4129
			quota = work + qlen;
4130
		}
E
Eric Dumazet 已提交
4131
		rps_unlock(sd);
4132 4133
	}
	local_irq_enable();
L
Linus Torvalds 已提交
4134

4135 4136
	return work;
}
L
Linus Torvalds 已提交
4137

4138 4139
/**
 * __napi_schedule - schedule for receive
4140
 * @n: entry to schedule
4141 4142 4143
 *
 * The entry's receive function will be scheduled to run
 */
H
Harvey Harrison 已提交
4144
void __napi_schedule(struct napi_struct *n)
4145 4146
{
	unsigned long flags;
L
Linus Torvalds 已提交
4147

4148
	local_irq_save(flags);
E
Eric Dumazet 已提交
4149
	____napi_schedule(&__get_cpu_var(softnet_data), n);
4150
	local_irq_restore(flags);
L
Linus Torvalds 已提交
4151
}
4152 4153
EXPORT_SYMBOL(__napi_schedule);

4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170 4171 4172 4173 4174 4175
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;

4176
	napi_gro_flush(n, false);
4177 4178 4179 4180 4181 4182
	local_irq_save(flags);
	__napi_complete(n);
	local_irq_restore(flags);
}
EXPORT_SYMBOL(napi_complete);

E
Eliezer Tamir 已提交
4183 4184 4185 4186 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
/* 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);

4235 4236 4237 4238
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);
4239
	napi->gro_count = 0;
4240
	napi->gro_list = NULL;
H
Herbert Xu 已提交
4241
	napi->skb = NULL;
4242
	napi->poll = poll;
E
Eric Dumazet 已提交
4243 4244 4245
	if (weight > NAPI_POLL_WEIGHT)
		pr_err_once("netif_napi_add() called with weight %d on device %s\n",
			    weight, dev->name);
4246 4247 4248
	napi->weight = weight;
	list_add(&napi->dev_list, &dev->napi_list);
	napi->dev = dev;
H
Herbert Xu 已提交
4249
#ifdef CONFIG_NETPOLL
4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260
	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)
{
	struct sk_buff *skb, *next;

4261
	list_del_init(&napi->dev_list);
4262
	napi_free_frags(napi);
4263 4264 4265 4266 4267 4268 4269 4270

	for (skb = napi->gro_list; skb; skb = next) {
		next = skb->next;
		skb->next = NULL;
		kfree_skb(skb);
	}

	napi->gro_list = NULL;
4271
	napi->gro_count = 0;
4272 4273 4274
}
EXPORT_SYMBOL(netif_napi_del);

L
Linus Torvalds 已提交
4275 4276
static void net_rx_action(struct softirq_action *h)
{
4277
	struct softnet_data *sd = &__get_cpu_var(softnet_data);
4278
	unsigned long time_limit = jiffies + 2;
4279
	int budget = netdev_budget;
4280 4281
	void *have;

L
Linus Torvalds 已提交
4282 4283
	local_irq_disable();

4284
	while (!list_empty(&sd->poll_list)) {
4285 4286
		struct napi_struct *n;
		int work, weight;
L
Linus Torvalds 已提交
4287

4288
		/* If softirq window is exhuasted then punt.
4289 4290
		 * Allow this to run for 2 jiffies since which will allow
		 * an average latency of 1.5/HZ.
4291
		 */
4292
		if (unlikely(budget <= 0 || time_after_eq(jiffies, time_limit)))
L
Linus Torvalds 已提交
4293 4294 4295 4296
			goto softnet_break;

		local_irq_enable();

4297 4298 4299 4300 4301
		/* 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.
		 */
4302
		n = list_first_entry(&sd->poll_list, struct napi_struct, poll_list);
L
Linus Torvalds 已提交
4303

4304 4305 4306 4307
		have = netpoll_poll_lock(n);

		weight = n->weight;

4308 4309 4310 4311
		/* 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
4312
		 * accidentally calling ->poll() when NAPI is not scheduled.
4313 4314
		 */
		work = 0;
4315
		if (test_bit(NAPI_STATE_SCHED, &n->state)) {
4316
			work = n->poll(n, weight);
4317 4318
			trace_napi_poll(n);
		}
4319 4320 4321 4322 4323 4324 4325 4326 4327 4328 4329 4330

		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.
		 */
4331
		if (unlikely(work == weight)) {
4332 4333 4334 4335
			if (unlikely(napi_disable_pending(n))) {
				local_irq_enable();
				napi_complete(n);
				local_irq_disable();
4336 4337 4338 4339 4340 4341 4342 4343 4344
			} 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();
				}
4345
				list_move_tail(&n->poll_list, &sd->poll_list);
4346
			}
4347
		}
4348 4349

		netpoll_poll_unlock(have);
L
Linus Torvalds 已提交
4350 4351
	}
out:
4352
	net_rps_action_and_irq_enable(sd);
T
Tom Herbert 已提交
4353

4354 4355 4356 4357 4358
#ifdef CONFIG_NET_DMA
	/*
	 * There may not be any more sk_buffs coming right now, so push
	 * any pending DMA copies to hardware
	 */
4359
	dma_issue_pending_all();
4360
#endif
4361

L
Linus Torvalds 已提交
4362 4363 4364
	return;

softnet_break:
C
Changli Gao 已提交
4365
	sd->time_squeeze++;
L
Linus Torvalds 已提交
4366 4367 4368 4369
	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
	goto out;
}

4370
struct netdev_adjacent {
J
Jiri Pirko 已提交
4371
	struct net_device *dev;
4372 4373

	/* upper master flag, there can only be one master device per list */
J
Jiri Pirko 已提交
4374
	bool master;
4375 4376 4377 4378 4379 4380 4381

	/* indicates that this dev is our first-level lower/upper device */
	bool neighbour;

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

J
Jiri Pirko 已提交
4382 4383 4384 4385 4386 4387 4388 4389
	struct list_head list;
	struct rcu_head rcu;
	struct list_head search_list;
};

static void __append_search_uppers(struct list_head *search_list,
				   struct net_device *dev)
{
4390
	struct netdev_adjacent *upper;
J
Jiri Pirko 已提交
4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402

	list_for_each_entry(upper, &dev->upper_dev_list, list) {
		/* check if this upper is not already in search list */
		if (list_empty(&upper->search_list))
			list_add_tail(&upper->search_list, search_list);
	}
}

static bool __netdev_search_upper_dev(struct net_device *dev,
				      struct net_device *upper_dev)
{
	LIST_HEAD(search_list);
4403 4404
	struct netdev_adjacent *upper;
	struct netdev_adjacent *tmp;
J
Jiri Pirko 已提交
4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 4418 4419
	bool ret = false;

	__append_search_uppers(&search_list, dev);
	list_for_each_entry(upper, &search_list, search_list) {
		if (upper->dev == upper_dev) {
			ret = true;
			break;
		}
		__append_search_uppers(&search_list, upper->dev);
	}
	list_for_each_entry_safe(upper, tmp, &search_list, search_list)
		INIT_LIST_HEAD(&upper->search_list);
	return ret;
}

4420 4421 4422
static struct netdev_adjacent *__netdev_find_adj(struct net_device *dev,
						 struct net_device *adj_dev,
						 bool upper)
J
Jiri Pirko 已提交
4423
{
4424 4425
	struct netdev_adjacent *adj;
	struct list_head *dev_list;
J
Jiri Pirko 已提交
4426

4427 4428 4429 4430 4431
	dev_list = upper ? &dev->upper_dev_list : &dev->lower_dev_list;

	list_for_each_entry(adj, dev_list, list) {
		if (adj->dev == adj_dev)
			return adj;
J
Jiri Pirko 已提交
4432 4433 4434 4435
	}
	return NULL;
}

4436 4437 4438 4439 4440 4441 4442 4443 4444 4445 4446 4447
static inline struct netdev_adjacent *__netdev_find_upper(struct net_device *dev,
							  struct net_device *udev)
{
	return __netdev_find_adj(dev, udev, true);
}

static inline struct netdev_adjacent *__netdev_find_lower(struct net_device *dev,
							  struct net_device *ldev)
{
	return __netdev_find_adj(dev, ldev, false);
}

J
Jiri Pirko 已提交
4448 4449 4450 4451 4452 4453 4454 4455 4456 4457 4458 4459 4460 4461 4462 4463 4464 4465 4466 4467 4468 4469 4470 4471 4472 4473 4474 4475 4476 4477 4478 4479 4480 4481 4482 4483 4484 4485 4486 4487 4488 4489
/**
 * 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();

	return __netdev_find_upper(dev, upper_dev);
}
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.
 */
bool netdev_has_any_upper_dev(struct net_device *dev)
{
	ASSERT_RTNL();

	return !list_empty(&dev->upper_dev_list);
}
EXPORT_SYMBOL(netdev_has_any_upper_dev);

/**
 * netdev_master_upper_dev_get - Get master upper device
 * @dev: device
 *
 * Find a master upper device and return pointer to it or NULL in case
 * it's not there. The caller must hold the RTNL lock.
 */
struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
{
4490
	struct netdev_adjacent *upper;
J
Jiri Pirko 已提交
4491 4492 4493 4494 4495 4496 4497

	ASSERT_RTNL();

	if (list_empty(&dev->upper_dev_list))
		return NULL;

	upper = list_first_entry(&dev->upper_dev_list,
4498
				 struct netdev_adjacent, list);
J
Jiri Pirko 已提交
4499 4500 4501 4502 4503 4504 4505 4506 4507 4508 4509 4510 4511 4512 4513
	if (likely(upper->master))
		return upper->dev;
	return NULL;
}
EXPORT_SYMBOL(netdev_master_upper_dev_get);

/**
 * 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)
{
4514
	struct netdev_adjacent *upper;
J
Jiri Pirko 已提交
4515 4516

	upper = list_first_or_null_rcu(&dev->upper_dev_list,
4517
				       struct netdev_adjacent, list);
J
Jiri Pirko 已提交
4518 4519 4520 4521 4522 4523
	if (upper && likely(upper->master))
		return upper->dev;
	return NULL;
}
EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);

4524 4525 4526 4527 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537 4538 4539 4540 4541 4542 4543 4544 4545 4546 4547 4548 4549 4550 4551 4552 4553 4554 4555 4556 4557 4558 4559 4560 4561 4562 4563 4564 4565 4566 4567 4568 4569 4570 4571 4572 4573 4574 4575 4576 4577 4578 4579 4580 4581 4582 4583 4584 4585 4586 4587 4588 4589 4590 4591 4592 4593 4594 4595 4596 4597 4598 4599 4600 4601 4602 4603 4604 4605 4606 4607 4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627 4628 4629 4630 4631 4632 4633 4634 4635 4636 4637 4638 4639 4640 4641 4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652 4653 4654 4655 4656 4657 4658 4659 4660 4661
static int __netdev_adjacent_dev_insert(struct net_device *dev,
					struct net_device *adj_dev,
					bool neighbour, bool master,
					bool upper)
{
	struct netdev_adjacent *adj;

	adj = __netdev_find_adj(dev, adj_dev, upper);

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

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

	adj->dev = adj_dev;
	adj->master = master;
	adj->neighbour = neighbour;
	adj->ref_nr = 1;
	INIT_LIST_HEAD(&adj->search_list);

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

	if (!upper) {
		list_add_tail_rcu(&adj->list, &dev->lower_dev_list);
		return 0;
	}

	/* Ensure that master upper link is always the first item in list. */
	if (master)
		list_add_rcu(&adj->list, &dev->upper_dev_list);
	else
		list_add_tail_rcu(&adj->list, &dev->upper_dev_list);

	return 0;
}

static inline int __netdev_upper_dev_insert(struct net_device *dev,
					    struct net_device *udev,
					    bool master, bool neighbour)
{
	return __netdev_adjacent_dev_insert(dev, udev, neighbour, master,
					    true);
}

static inline int __netdev_lower_dev_insert(struct net_device *dev,
					    struct net_device *ldev,
					    bool neighbour)
{
	return __netdev_adjacent_dev_insert(dev, ldev, neighbour, false,
					    false);
}

void __netdev_adjacent_dev_remove(struct net_device *dev,
				  struct net_device *adj_dev, bool upper)
{
	struct netdev_adjacent *adj;

	if (upper)
		adj = __netdev_find_upper(dev, adj_dev);
	else
		adj = __netdev_find_lower(dev, adj_dev);

	if (!adj)
		BUG();

	if (adj->ref_nr > 1) {
		adj->ref_nr--;
		return;
	}

	list_del_rcu(&adj->list);
	pr_debug("dev_put for %s, because of %s link removed from %s to %s\n",
		 adj_dev->name, upper ? "upper" : "lower", dev->name,
		 adj_dev->name);
	dev_put(adj_dev);
	kfree_rcu(adj, rcu);
}

static inline void __netdev_upper_dev_remove(struct net_device *dev,
					     struct net_device *udev)
{
	return __netdev_adjacent_dev_remove(dev, udev, true);
}

static inline void __netdev_lower_dev_remove(struct net_device *dev,
					     struct net_device *ldev)
{
	return __netdev_adjacent_dev_remove(dev, ldev, false);
}

int __netdev_adjacent_dev_insert_link(struct net_device *dev,
				      struct net_device *upper_dev,
				      bool master, bool neighbour)
{
	int ret;

	ret = __netdev_upper_dev_insert(dev, upper_dev, master, neighbour);
	if (ret)
		return ret;

	ret = __netdev_lower_dev_insert(upper_dev, dev, neighbour);
	if (ret) {
		__netdev_upper_dev_remove(dev, upper_dev);
		return ret;
	}

	return 0;
}

static inline int __netdev_adjacent_dev_link(struct net_device *dev,
					     struct net_device *udev)
{
	return __netdev_adjacent_dev_insert_link(dev, udev, false, false);
}

static inline int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
						       struct net_device *udev,
						       bool master)
{
	return __netdev_adjacent_dev_insert_link(dev, udev, master, true);
}

void __netdev_adjacent_dev_unlink(struct net_device *dev,
				  struct net_device *upper_dev)
{
	__netdev_upper_dev_remove(dev, upper_dev);
	__netdev_lower_dev_remove(upper_dev, dev);
}


J
Jiri Pirko 已提交
4662 4663 4664
static int __netdev_upper_dev_link(struct net_device *dev,
				   struct net_device *upper_dev, bool master)
{
4665 4666
	struct netdev_adjacent *i, *j, *to_i, *to_j;
	int ret = 0;
J
Jiri Pirko 已提交
4667 4668 4669 4670 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682

	ASSERT_RTNL();

	if (dev == upper_dev)
		return -EBUSY;

	/* To prevent loops, check if dev is not upper device to upper_dev. */
	if (__netdev_search_upper_dev(upper_dev, dev))
		return -EBUSY;

	if (__netdev_find_upper(dev, upper_dev))
		return -EEXIST;

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

4683 4684 4685
	ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, master);
	if (ret)
		return ret;
J
Jiri Pirko 已提交
4686

4687 4688 4689 4690 4691 4692 4693 4694 4695 4696 4697 4698 4699 4700 4701 4702 4703 4704 4705 4706 4707 4708 4709 4710 4711 4712
	/* Now that we linked these devs, make all the upper_dev's
	 * upper_dev_list visible to every dev's lower_dev_list and vice
	 * versa, and don't forget the devices itself. All of these
	 * links are non-neighbours.
	 */
	list_for_each_entry(i, &upper_dev->upper_dev_list, list) {
		list_for_each_entry(j, &dev->lower_dev_list, list) {
			ret = __netdev_adjacent_dev_link(i->dev, j->dev);
			if (ret)
				goto rollback_mesh;
		}
	}

	/* add dev to every upper_dev's upper device */
	list_for_each_entry(i, &upper_dev->upper_dev_list, list) {
		ret = __netdev_adjacent_dev_link(dev, i->dev);
		if (ret)
			goto rollback_upper_mesh;
	}

	/* add upper_dev to every dev's lower device */
	list_for_each_entry(i, &dev->lower_dev_list, list) {
		ret = __netdev_adjacent_dev_link(i->dev, upper_dev);
		if (ret)
			goto rollback_lower_mesh;
	}
J
Jiri Pirko 已提交
4713

4714
	call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev);
J
Jiri Pirko 已提交
4715
	return 0;
4716 4717 4718 4719 4720 4721 4722 4723 4724 4725 4726 4727 4728 4729 4730 4731 4732 4733 4734 4735 4736 4737 4738 4739 4740 4741 4742 4743 4744 4745 4746 4747 4748 4749 4750 4751 4752

rollback_lower_mesh:
	to_i = i;
	list_for_each_entry(i, &dev->lower_dev_list, list) {
		if (i == to_i)
			break;
		__netdev_adjacent_dev_unlink(i->dev, upper_dev);
	}

	i = NULL;

rollback_upper_mesh:
	to_i = i;
	list_for_each_entry(i, &upper_dev->upper_dev_list, list) {
		if (i == to_i)
			break;
		__netdev_adjacent_dev_unlink(dev, i->dev);
	}

	i = j = NULL;

rollback_mesh:
	to_i = i;
	to_j = j;
	list_for_each_entry(i, &dev->lower_dev_list, list) {
		list_for_each_entry(j, &upper_dev->upper_dev_list, list) {
			if (i == to_i && j == to_j)
				break;
			__netdev_adjacent_dev_unlink(i->dev, j->dev);
		}
		if (i == to_i)
			break;
	}

	__netdev_adjacent_dev_unlink(dev, upper_dev);

	return ret;
J
Jiri Pirko 已提交
4753 4754 4755 4756 4757 4758 4759 4760 4761 4762 4763 4764 4765 4766 4767 4768 4769 4770 4771 4772 4773 4774 4775 4776 4777 4778 4779 4780 4781 4782 4783 4784 4785 4786 4787 4788 4789 4790 4791 4792 4793 4794 4795 4796 4797 4798 4799 4800
}

/**
 * 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)
{
	return __netdev_upper_dev_link(dev, upper_dev, false);
}
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)
{
	return __netdev_upper_dev_link(dev, upper_dev, true);
}
EXPORT_SYMBOL(netdev_master_upper_dev_link);

/**
 * netdev_upper_dev_unlink - Removes a link to upper device
 * @dev: device
 * @upper_dev: new upper device
 *
 * Removes a link to device which is upper to this one. The caller must hold
 * the RTNL lock.
 */
void netdev_upper_dev_unlink(struct net_device *dev,
			     struct net_device *upper_dev)
{
4801
	struct netdev_adjacent *i, *j;
J
Jiri Pirko 已提交
4802 4803
	ASSERT_RTNL();

4804 4805 4806 4807 4808 4809 4810 4811 4812 4813 4814 4815 4816 4817 4818 4819 4820 4821 4822
	__netdev_adjacent_dev_unlink(dev, upper_dev);

	/* 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.
	 */
	list_for_each_entry(i, &dev->lower_dev_list, list)
		list_for_each_entry(j, &upper_dev->upper_dev_list, list)
			__netdev_adjacent_dev_unlink(i->dev, j->dev);

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

	list_for_each_entry(i, &upper_dev->upper_dev_list, list)
		__netdev_adjacent_dev_unlink(dev, i->dev);

4823
	call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev);
J
Jiri Pirko 已提交
4824 4825 4826
}
EXPORT_SYMBOL(netdev_upper_dev_unlink);

4827 4828
static void dev_change_rx_flags(struct net_device *dev, int flags)
{
4829 4830 4831 4832
	const struct net_device_ops *ops = dev->netdev_ops;

	if ((dev->flags & IFF_UP) && ops->ndo_change_rx_flags)
		ops->ndo_change_rx_flags(dev, flags);
4833 4834
}

4835
static int __dev_set_promiscuity(struct net_device *dev, int inc)
L
Linus Torvalds 已提交
4836
{
4837
	unsigned int old_flags = dev->flags;
4838 4839
	kuid_t uid;
	kgid_t gid;
L
Linus Torvalds 已提交
4840

4841 4842
	ASSERT_RTNL();

4843 4844 4845 4846 4847 4848 4849 4850 4851 4852 4853
	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;
4854 4855
			pr_warn("%s: promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n",
				dev->name);
4856 4857 4858
			return -EOVERFLOW;
		}
	}
4859
	if (dev->flags != old_flags) {
4860 4861 4862
		pr_info("device %s %s promiscuous mode\n",
			dev->name,
			dev->flags & IFF_PROMISC ? "entered" : "left");
4863 4864
		if (audit_enabled) {
			current_uid_gid(&uid, &gid);
4865 4866 4867 4868 4869
			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),
4870
				from_kuid(&init_user_ns, audit_get_loginuid(current)),
4871 4872
				from_kuid(&init_user_ns, uid),
				from_kgid(&init_user_ns, gid),
4873
				audit_get_sessionid(current));
4874
		}
4875

4876
		dev_change_rx_flags(dev, IFF_PROMISC);
L
Linus Torvalds 已提交
4877
	}
4878
	return 0;
L
Linus Torvalds 已提交
4879 4880
}

4881 4882 4883 4884 4885 4886 4887 4888 4889
/**
 *	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.
4890
 *	Return 0 if successful or a negative errno code on error.
4891
 */
4892
int dev_set_promiscuity(struct net_device *dev, int inc)
4893
{
4894
	unsigned int old_flags = dev->flags;
4895
	int err;
4896

4897
	err = __dev_set_promiscuity(dev, inc);
4898
	if (err < 0)
4899
		return err;
4900 4901
	if (dev->flags != old_flags)
		dev_set_rx_mode(dev);
4902
	return err;
4903
}
E
Eric Dumazet 已提交
4904
EXPORT_SYMBOL(dev_set_promiscuity);
4905

L
Linus Torvalds 已提交
4906 4907 4908 4909 4910 4911 4912 4913 4914 4915
/**
 *	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.
4916
 *	Return 0 if successful or a negative errno code on error.
L
Linus Torvalds 已提交
4917 4918
 */

4919
int dev_set_allmulti(struct net_device *dev, int inc)
L
Linus Torvalds 已提交
4920
{
4921
	unsigned int old_flags = dev->flags;
L
Linus Torvalds 已提交
4922

4923 4924
	ASSERT_RTNL();

L
Linus Torvalds 已提交
4925
	dev->flags |= IFF_ALLMULTI;
4926 4927 4928 4929 4930 4931 4932 4933 4934 4935
	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;
4936 4937
			pr_warn("%s: allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n",
				dev->name);
4938 4939 4940
			return -EOVERFLOW;
		}
	}
4941
	if (dev->flags ^ old_flags) {
4942
		dev_change_rx_flags(dev, IFF_ALLMULTI);
4943
		dev_set_rx_mode(dev);
4944
	}
4945
	return 0;
4946
}
E
Eric Dumazet 已提交
4947
EXPORT_SYMBOL(dev_set_allmulti);
4948 4949 4950 4951

/*
 *	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
4952
 *	filtering it is put in promiscuous mode while unicast addresses
4953 4954 4955 4956
 *	are present.
 */
void __dev_set_rx_mode(struct net_device *dev)
{
4957 4958
	const struct net_device_ops *ops = dev->netdev_ops;

4959 4960 4961 4962 4963
	/* dev_open will call this function so the list will stay sane. */
	if (!(dev->flags&IFF_UP))
		return;

	if (!netif_device_present(dev))
4964
		return;
4965

4966
	if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
4967 4968 4969
		/* Unicast addresses changes may only happen under the rtnl,
		 * therefore calling __dev_set_promiscuity here is safe.
		 */
4970
		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
4971
			__dev_set_promiscuity(dev, 1);
4972
			dev->uc_promisc = true;
4973
		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
4974
			__dev_set_promiscuity(dev, -1);
4975
			dev->uc_promisc = false;
4976 4977
		}
	}
4978 4979 4980

	if (ops->ndo_set_rx_mode)
		ops->ndo_set_rx_mode(dev);
4981 4982 4983 4984
}

void dev_set_rx_mode(struct net_device *dev)
{
4985
	netif_addr_lock_bh(dev);
4986
	__dev_set_rx_mode(dev);
4987
	netif_addr_unlock_bh(dev);
L
Linus Torvalds 已提交
4988 4989
}

4990 4991 4992 4993 4994 4995
/**
 *	dev_get_flags - get flags reported to userspace
 *	@dev: device
 *
 *	Get the combination of flag bits exported through APIs to userspace.
 */
4996
unsigned int dev_get_flags(const struct net_device *dev)
L
Linus Torvalds 已提交
4997
{
4998
	unsigned int flags;
L
Linus Torvalds 已提交
4999 5000 5001

	flags = (dev->flags & ~(IFF_PROMISC |
				IFF_ALLMULTI |
S
Stefan Rompf 已提交
5002 5003 5004
				IFF_RUNNING |
				IFF_LOWER_UP |
				IFF_DORMANT)) |
L
Linus Torvalds 已提交
5005 5006 5007
		(dev->gflags & (IFF_PROMISC |
				IFF_ALLMULTI));

S
Stefan Rompf 已提交
5008 5009 5010 5011 5012 5013 5014 5015
	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
5016 5017 5018

	return flags;
}
E
Eric Dumazet 已提交
5019
EXPORT_SYMBOL(dev_get_flags);
L
Linus Torvalds 已提交
5020

5021
int __dev_change_flags(struct net_device *dev, unsigned int flags)
L
Linus Torvalds 已提交
5022
{
5023
	unsigned int old_flags = dev->flags;
5024
	int ret;
L
Linus Torvalds 已提交
5025

5026 5027
	ASSERT_RTNL();

L
Linus Torvalds 已提交
5028 5029 5030 5031 5032 5033 5034 5035 5036 5037 5038 5039 5040 5041
	/*
	 *	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.
	 */

5042 5043
	if ((old_flags ^ flags) & IFF_MULTICAST)
		dev_change_rx_flags(dev, IFF_MULTICAST);
5044

5045
	dev_set_rx_mode(dev);
L
Linus Torvalds 已提交
5046 5047 5048 5049 5050 5051 5052 5053 5054

	/*
	 *	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  ? */
5055
		ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev);
L
Linus Torvalds 已提交
5056 5057

		if (!ret)
5058
			dev_set_rx_mode(dev);
L
Linus Torvalds 已提交
5059 5060 5061
	}

	if ((flags ^ dev->gflags) & IFF_PROMISC) {
E
Eric Dumazet 已提交
5062 5063
		int inc = (flags & IFF_PROMISC) ? 1 : -1;

L
Linus Torvalds 已提交
5064 5065 5066 5067 5068 5069 5070 5071 5072
		dev->gflags ^= IFF_PROMISC;
		dev_set_promiscuity(dev, inc);
	}

	/* 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
5073 5074
		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;

L
Linus Torvalds 已提交
5075 5076 5077 5078
		dev->gflags ^= IFF_ALLMULTI;
		dev_set_allmulti(dev, inc);
	}

5079 5080 5081 5082 5083 5084 5085 5086 5087 5088 5089 5090 5091 5092 5093
	return ret;
}

void __dev_notify_flags(struct net_device *dev, unsigned int old_flags)
{
	unsigned int changes = dev->flags ^ old_flags;

	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 &&
5094 5095 5096 5097 5098 5099 5100
	    (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);
	}
5101 5102 5103 5104 5105 5106 5107 5108 5109 5110
}

/**
 *	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.
 */
5111
int dev_change_flags(struct net_device *dev, unsigned int flags)
5112
{
5113 5114
	int ret;
	unsigned int changes, old_flags = dev->flags;
5115 5116 5117 5118 5119 5120

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

	changes = old_flags ^ dev->flags;
5121 5122
	if (changes)
		rtmsg_ifinfo(RTM_NEWLINK, dev, changes);
L
Linus Torvalds 已提交
5123

5124
	__dev_notify_flags(dev, old_flags);
L
Linus Torvalds 已提交
5125 5126
	return ret;
}
E
Eric Dumazet 已提交
5127
EXPORT_SYMBOL(dev_change_flags);
L
Linus Torvalds 已提交
5128

5129 5130 5131 5132 5133 5134 5135
/**
 *	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
5136 5137
int dev_set_mtu(struct net_device *dev, int new_mtu)
{
5138
	const struct net_device_ops *ops = dev->netdev_ops;
L
Linus Torvalds 已提交
5139 5140 5141 5142 5143 5144 5145 5146 5147 5148 5149 5150 5151
	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;
5152 5153
	if (ops->ndo_change_mtu)
		err = ops->ndo_change_mtu(dev, new_mtu);
L
Linus Torvalds 已提交
5154 5155
	else
		dev->mtu = new_mtu;
5156

5157
	if (!err)
5158
		call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
L
Linus Torvalds 已提交
5159 5160
	return err;
}
E
Eric Dumazet 已提交
5161
EXPORT_SYMBOL(dev_set_mtu);
L
Linus Torvalds 已提交
5162

5163 5164 5165 5166 5167 5168 5169 5170 5171 5172 5173
/**
 *	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);

5174 5175 5176 5177 5178 5179 5180
/**
 *	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
5181 5182
int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
{
5183
	const struct net_device_ops *ops = dev->netdev_ops;
L
Linus Torvalds 已提交
5184 5185
	int err;

5186
	if (!ops->ndo_set_mac_address)
L
Linus Torvalds 已提交
5187 5188 5189 5190 5191
		return -EOPNOTSUPP;
	if (sa->sa_family != dev->type)
		return -EINVAL;
	if (!netif_device_present(dev))
		return -ENODEV;
5192
	err = ops->ndo_set_mac_address(dev, sa);
5193 5194
	if (err)
		return err;
J
Jiri Pirko 已提交
5195
	dev->addr_assign_type = NET_ADDR_SET;
5196
	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
5197
	add_device_randomness(dev->dev_addr, dev->addr_len);
5198
	return 0;
L
Linus Torvalds 已提交
5199
}
E
Eric Dumazet 已提交
5200
EXPORT_SYMBOL(dev_set_mac_address);
L
Linus Torvalds 已提交
5201

J
Jiri Pirko 已提交
5202 5203 5204
/**
 *	dev_change_carrier - Change device carrier
 *	@dev: device
5205
 *	@new_carrier: new value
J
Jiri Pirko 已提交
5206 5207 5208 5209 5210 5211 5212 5213 5214 5215 5216 5217 5218 5219 5220
 *
 *	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);

5221 5222 5223 5224 5225 5226 5227 5228 5229 5230 5231 5232 5233 5234 5235 5236 5237 5238
/**
 *	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
5239 5240
/**
 *	dev_new_index	-	allocate an ifindex
5241
 *	@net: the applicable net namespace
L
Linus Torvalds 已提交
5242 5243 5244 5245 5246
 *
 *	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.
 */
5247
static int dev_new_index(struct net *net)
L
Linus Torvalds 已提交
5248
{
5249
	int ifindex = net->ifindex;
L
Linus Torvalds 已提交
5250 5251 5252
	for (;;) {
		if (++ifindex <= 0)
			ifindex = 1;
5253
		if (!__dev_get_by_index(net, ifindex))
5254
			return net->ifindex = ifindex;
L
Linus Torvalds 已提交
5255 5256 5257 5258
	}
}

/* Delayed registration/unregisteration */
5259
static LIST_HEAD(net_todo_list);
L
Linus Torvalds 已提交
5260

5261
static void net_set_todo(struct net_device *dev)
L
Linus Torvalds 已提交
5262 5263 5264 5265
{
	list_add_tail(&dev->todo_list, &net_todo_list);
}

5266
static void rollback_registered_many(struct list_head *head)
5267
{
5268
	struct net_device *dev, *tmp;
5269

5270 5271 5272
	BUG_ON(dev_boot_phase);
	ASSERT_RTNL();

5273
	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
5274
		/* Some devices call without registering
5275 5276
		 * for initialization unwind. Remove those
		 * devices and proceed with the remaining.
5277 5278
		 */
		if (dev->reg_state == NETREG_UNINITIALIZED) {
5279 5280
			pr_debug("unregister_netdevice: device %s/%p never was registered\n",
				 dev->name, dev);
5281

5282
			WARN_ON(1);
5283 5284
			list_del(&dev->unreg_list);
			continue;
5285
		}
5286
		dev->dismantle = true;
5287
		BUG_ON(dev->reg_state != NETREG_REGISTERED);
5288
	}
5289

5290 5291
	/* If device is running, close it first. */
	dev_close_many(head);
5292

5293
	list_for_each_entry(dev, head, unreg_list) {
5294 5295
		/* And unlink it from device chain. */
		unlist_netdevice(dev);
5296

5297 5298
		dev->reg_state = NETREG_UNREGISTERING;
	}
5299 5300 5301

	synchronize_net();

5302 5303 5304
	list_for_each_entry(dev, head, unreg_list) {
		/* Shutdown queueing discipline. */
		dev_shutdown(dev);
5305 5306


5307 5308 5309 5310
		/* Notify protocols, that we are about to destroy
		   this device. They should clean all the things.
		*/
		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5311

5312 5313 5314 5315
		if (!dev->rtnl_link_ops ||
		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
			rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);

5316 5317 5318
		/*
		 *	Flush the unicast and multicast chains
		 */
5319
		dev_uc_flush(dev);
5320
		dev_mc_flush(dev);
5321

5322 5323
		if (dev->netdev_ops->ndo_uninit)
			dev->netdev_ops->ndo_uninit(dev);
5324

J
Jiri Pirko 已提交
5325 5326
		/* Notifier chain MUST detach us all upper devices. */
		WARN_ON(netdev_has_any_upper_dev(dev));
5327

5328 5329
		/* Remove entries from kobject tree */
		netdev_unregister_kobject(dev);
5330 5331 5332 5333
#ifdef CONFIG_XPS
		/* Remove XPS queueing entries */
		netif_reset_xps_queues_gt(dev, 0);
#endif
5334
	}
5335

5336
	synchronize_net();
5337

5338
	list_for_each_entry(dev, head, unreg_list)
5339 5340 5341 5342 5343 5344 5345 5346 5347
		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
5348
	list_del(&single);
5349 5350
}

5351 5352
static netdev_features_t netdev_fix_features(struct net_device *dev,
	netdev_features_t features)
5353
{
5354 5355 5356
	/* Fix illegal checksum combinations */
	if ((features & NETIF_F_HW_CSUM) &&
	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5357
		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
5358 5359 5360
		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
	}

5361
	/* TSO requires that SG is present as well. */
5362
	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
5363
		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
5364
		features &= ~NETIF_F_ALL_TSO;
5365 5366
	}

5367 5368 5369 5370 5371 5372 5373 5374 5375 5376 5377 5378 5379
	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;
	}

5380 5381 5382 5383
	/* TSO ECN requires that TSO is present as well. */
	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
		features &= ~NETIF_F_TSO_ECN;

5384 5385
	/* Software GSO depends on SG. */
	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
5386
		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
5387 5388 5389
		features &= ~NETIF_F_GSO;
	}

5390
	/* UFO needs SG and checksumming */
5391
	if (features & NETIF_F_UFO) {
5392 5393 5394 5395
		/* 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))) {
5396
			netdev_dbg(dev,
5397
				"Dropping NETIF_F_UFO since no checksum offload features.\n");
5398 5399 5400 5401
			features &= ~NETIF_F_UFO;
		}

		if (!(features & NETIF_F_SG)) {
5402
			netdev_dbg(dev,
5403
				"Dropping NETIF_F_UFO since no NETIF_F_SG feature.\n");
5404 5405 5406 5407 5408 5409 5410
			features &= ~NETIF_F_UFO;
		}
	}

	return features;
}

5411
int __netdev_update_features(struct net_device *dev)
5412
{
5413
	netdev_features_t features;
5414 5415
	int err = 0;

5416 5417
	ASSERT_RTNL();

5418 5419 5420 5421 5422 5423 5424 5425 5426
	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)
5427
		return 0;
5428

5429 5430
	netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
		&dev->features, &features);
5431 5432 5433 5434

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

5435
	if (unlikely(err < 0)) {
5436
		netdev_err(dev,
5437 5438
			"set_features() failed (%d); wanted %pNF, left %pNF\n",
			err, &features, &dev->features);
5439 5440 5441 5442 5443 5444 5445 5446 5447
		return -1;
	}

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

	return 1;
}

5448 5449 5450 5451 5452 5453 5454 5455
/**
 *	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.
 */
5456 5457 5458 5459
void netdev_update_features(struct net_device *dev)
{
	if (__netdev_update_features(dev))
		netdev_features_change(dev);
5460 5461 5462
}
EXPORT_SYMBOL(netdev_update_features);

5463 5464 5465 5466 5467 5468 5469 5470 5471 5472 5473 5474 5475 5476 5477 5478 5479
/**
 *	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);

5480 5481 5482 5483 5484 5485 5486 5487 5488 5489 5490 5491 5492 5493 5494 5495 5496 5497 5498 5499 5500 5501 5502 5503 5504 5505 5506
/**
 *	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
5507
#ifdef CONFIG_RPS
5508 5509 5510
static int netif_alloc_rx_queues(struct net_device *dev)
{
	unsigned int i, count = dev->num_rx_queues;
T
Tom Herbert 已提交
5511
	struct netdev_rx_queue *rx;
5512

T
Tom Herbert 已提交
5513
	BUG_ON(count < 1);
5514

T
Tom Herbert 已提交
5515
	rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL);
5516
	if (!rx)
T
Tom Herbert 已提交
5517
		return -ENOMEM;
5518

T
Tom Herbert 已提交
5519 5520 5521
	dev->_rx = rx;

	for (i = 0; i < count; i++)
T
Tom Herbert 已提交
5522
		rx[i].dev = dev;
5523 5524
	return 0;
}
T
Tom Herbert 已提交
5525
#endif
5526

C
Changli Gao 已提交
5527 5528 5529 5530 5531 5532 5533
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;
5534
	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
C
Changli Gao 已提交
5535
	queue->dev = dev;
T
Tom Herbert 已提交
5536 5537 5538
#ifdef CONFIG_BQL
	dql_init(&queue->dql, HZ);
#endif
C
Changli Gao 已提交
5539 5540
}

5541 5542 5543 5544 5545 5546 5547 5548
static void netif_free_tx_queues(struct net_device *dev)
{
	if (is_vmalloc_addr(dev->_tx))
		vfree(dev->_tx);
	else
		kfree(dev->_tx);
}

5549 5550 5551 5552
static int netif_alloc_netdev_queues(struct net_device *dev)
{
	unsigned int count = dev->num_tx_queues;
	struct netdev_queue *tx;
5553
	size_t sz = count * sizeof(*tx);
5554

5555
	BUG_ON(count < 1 || count > 0xffff);
5556

5557 5558 5559 5560 5561 5562
	tx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
	if (!tx) {
		tx = vzalloc(sz);
		if (!tx)
			return -ENOMEM;
	}
5563
	dev->_tx = tx;
T
Tom Herbert 已提交
5564

5565 5566
	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
	spin_lock_init(&dev->tx_global_lock);
C
Changli Gao 已提交
5567 5568

	return 0;
5569 5570
}

L
Linus Torvalds 已提交
5571 5572 5573 5574 5575 5576 5577 5578 5579 5580 5581 5582 5583 5584 5585 5586 5587 5588 5589 5590
/**
 *	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;
5591
	struct net *net = dev_net(dev);
L
Linus Torvalds 已提交
5592 5593 5594 5595

	BUG_ON(dev_boot_phase);
	ASSERT_RTNL();

5596 5597
	might_sleep();

L
Linus Torvalds 已提交
5598 5599
	/* When net_device's are persistent, this will be fatal. */
	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
5600
	BUG_ON(!net);
L
Linus Torvalds 已提交
5601

5602
	spin_lock_init(&dev->addr_list_lock);
5603
	netdev_set_addr_lockdep_class(dev);
L
Linus Torvalds 已提交
5604 5605 5606

	dev->iflink = -1;

5607
	ret = dev_get_valid_name(net, dev, dev->name);
5608 5609 5610
	if (ret < 0)
		goto out;

L
Linus Torvalds 已提交
5611
	/* Init, if this function is available */
5612 5613
	if (dev->netdev_ops->ndo_init) {
		ret = dev->netdev_ops->ndo_init(dev);
L
Linus Torvalds 已提交
5614 5615 5616
		if (ret) {
			if (ret > 0)
				ret = -EIO;
5617
			goto out;
L
Linus Torvalds 已提交
5618 5619
		}
	}
5620

5621 5622
	if (((dev->hw_features | dev->features) &
	     NETIF_F_HW_VLAN_CTAG_FILTER) &&
5623 5624 5625 5626 5627 5628 5629
	    (!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;
	}

5630 5631 5632 5633 5634 5635
	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
5636 5637 5638
	if (dev->iflink == -1)
		dev->iflink = dev->ifindex;

5639 5640 5641 5642
	/* Transfer changeable features to wanted_features and enable
	 * software offloads (GSO and GRO).
	 */
	dev->hw_features |= NETIF_F_SOFT_FEATURES;
5643 5644
	dev->features |= NETIF_F_SOFT_FEATURES;
	dev->wanted_features = dev->features & dev->hw_features;
L
Linus Torvalds 已提交
5645

5646
	/* Turn on no cache copy if HW is doing checksum */
5647 5648 5649 5650 5651 5652
	if (!(dev->flags & IFF_LOOPBACK)) {
		dev->hw_features |= NETIF_F_NOCACHE_COPY;
		if (dev->features & NETIF_F_ALL_CSUM) {
			dev->wanted_features |= NETIF_F_NOCACHE_COPY;
			dev->features |= NETIF_F_NOCACHE_COPY;
		}
5653 5654
	}

5655
	/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
5656
	 */
5657
	dev->vlan_features |= NETIF_F_HIGHDMA;
5658

5659 5660 5661 5662
	/* Make NETIF_F_SG inheritable to tunnel devices.
	 */
	dev->hw_enc_features |= NETIF_F_SG;

S
Simon Horman 已提交
5663 5664 5665 5666
	/* Make NETIF_F_SG inheritable to MPLS.
	 */
	dev->mpls_features |= NETIF_F_SG;

5667 5668 5669 5670 5671
	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
	ret = notifier_to_errno(ret);
	if (ret)
		goto err_uninit;

5672
	ret = netdev_register_kobject(dev);
5673
	if (ret)
5674
		goto err_uninit;
5675 5676
	dev->reg_state = NETREG_REGISTERED;

5677
	__netdev_update_features(dev);
5678

L
Linus Torvalds 已提交
5679 5680 5681 5682 5683 5684 5685
	/*
	 *	Default initial state at registry is that the
	 *	device is present.
	 */

	set_bit(__LINK_STATE_PRESENT, &dev->state);

5686 5687
	linkwatch_init_dev(dev);

L
Linus Torvalds 已提交
5688 5689
	dev_init_scheduler(dev);
	dev_hold(dev);
5690
	list_netdevice(dev);
5691
	add_device_randomness(dev->dev_addr, dev->addr_len);
L
Linus Torvalds 已提交
5692

5693 5694 5695 5696 5697 5698 5699
	/* 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
5700
	/* Notify protocols, that a new device appeared. */
5701
	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
5702
	ret = notifier_to_errno(ret);
5703 5704 5705 5706
	if (ret) {
		rollback_registered(dev);
		dev->reg_state = NETREG_UNREGISTERED;
	}
5707 5708 5709 5710
	/*
	 *	Prevent userspace races by waiting until the network
	 *	device is fully setup before sending notifications.
	 */
5711 5712 5713
	if (!dev->rtnl_link_ops ||
	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
L
Linus Torvalds 已提交
5714 5715 5716

out:
	return ret;
5717 5718

err_uninit:
5719 5720
	if (dev->netdev_ops->ndo_uninit)
		dev->netdev_ops->ndo_uninit(dev);
5721
	goto out;
L
Linus Torvalds 已提交
5722
}
E
Eric Dumazet 已提交
5723
EXPORT_SYMBOL(register_netdevice);
L
Linus Torvalds 已提交
5724

5725 5726 5727 5728 5729 5730 5731 5732 5733 5734 5735 5736 5737 5738 5739 5740 5741 5742 5743 5744 5745 5746 5747 5748 5749 5750 5751 5752 5753 5754 5755
/**
 *	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
5756 5757 5758 5759 5760
	/* Note : We dont allocate pcpu_refcnt for dummy devices,
	 * because users of this 'device' dont need to change
	 * its refcount.
	 */

5761 5762 5763 5764 5765
	return 0;
}
EXPORT_SYMBOL_GPL(init_dummy_netdev);


L
Linus Torvalds 已提交
5766 5767 5768 5769 5770 5771 5772 5773 5774
/**
 *	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.
 *
5775
 *	This is a wrapper around register_netdevice that takes the rtnl semaphore
L
Linus Torvalds 已提交
5776 5777 5778 5779 5780 5781 5782 5783 5784 5785 5786 5787 5788 5789
 *	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
5790 5791 5792 5793 5794 5795 5796 5797 5798 5799
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);

5800
/**
L
Linus Torvalds 已提交
5801
 * netdev_wait_allrefs - wait until all references are gone.
5802
 * @dev: target net_device
L
Linus Torvalds 已提交
5803 5804 5805 5806 5807 5808 5809
 *
 * 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
5810
 * call dev_put.
L
Linus Torvalds 已提交
5811 5812 5813 5814
 */
static void netdev_wait_allrefs(struct net_device *dev)
{
	unsigned long rebroadcast_time, warning_time;
E
Eric Dumazet 已提交
5815
	int refcnt;
L
Linus Torvalds 已提交
5816

5817 5818
	linkwatch_forget_dev(dev);

L
Linus Torvalds 已提交
5819
	rebroadcast_time = warning_time = jiffies;
E
Eric Dumazet 已提交
5820 5821 5822
	refcnt = netdev_refcnt_read(dev);

	while (refcnt != 0) {
L
Linus Torvalds 已提交
5823
		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
5824
			rtnl_lock();
L
Linus Torvalds 已提交
5825 5826

			/* Rebroadcast unregister notification */
5827
			call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
L
Linus Torvalds 已提交
5828

5829
			__rtnl_unlock();
5830
			rcu_barrier();
5831 5832
			rtnl_lock();

5833
			call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
L
Linus Torvalds 已提交
5834 5835 5836 5837 5838 5839 5840 5841 5842 5843 5844
			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();
			}

5845
			__rtnl_unlock();
L
Linus Torvalds 已提交
5846 5847 5848 5849 5850 5851

			rebroadcast_time = jiffies;
		}

		msleep(250);

E
Eric Dumazet 已提交
5852 5853
		refcnt = netdev_refcnt_read(dev);

L
Linus Torvalds 已提交
5854
		if (time_after(jiffies, warning_time + 10 * HZ)) {
5855 5856
			pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
				 dev->name, refcnt);
L
Linus Torvalds 已提交
5857 5858 5859 5860 5861 5862 5863 5864 5865 5866 5867 5868 5869 5870 5871 5872 5873 5874 5875
			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
5876
 * We are invoked by rtnl_unlock().
L
Linus Torvalds 已提交
5877
 * This allows us to deal with problems:
5878
 * 1) We can delete sysfs objects which invoke hotplug
L
Linus Torvalds 已提交
5879 5880 5881
 *    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
5882 5883 5884
 *
 * 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
5885 5886 5887
 */
void netdev_run_todo(void)
{
5888
	struct list_head list;
L
Linus Torvalds 已提交
5889 5890

	/* Snapshot list, allow later requests */
5891
	list_replace_init(&net_todo_list, &list);
H
Herbert Xu 已提交
5892 5893

	__rtnl_unlock();
5894

5895 5896

	/* Wait for rcu callbacks to finish before next phase */
5897 5898 5899
	if (!list_empty(&list))
		rcu_barrier();

L
Linus Torvalds 已提交
5900 5901
	while (!list_empty(&list)) {
		struct net_device *dev
5902
			= list_first_entry(&list, struct net_device, todo_list);
L
Linus Torvalds 已提交
5903 5904
		list_del(&dev->todo_list);

5905
		rtnl_lock();
5906
		call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
5907
		__rtnl_unlock();
5908

5909
		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
5910
			pr_err("network todo '%s' but state %d\n",
5911 5912 5913 5914
			       dev->name, dev->reg_state);
			dump_stack();
			continue;
		}
L
Linus Torvalds 已提交
5915

5916
		dev->reg_state = NETREG_UNREGISTERED;
L
Linus Torvalds 已提交
5917

5918
		on_each_cpu(flush_backlog, dev, 1);
5919

5920
		netdev_wait_allrefs(dev);
L
Linus Torvalds 已提交
5921

5922
		/* paranoia */
E
Eric Dumazet 已提交
5923
		BUG_ON(netdev_refcnt_read(dev));
5924 5925
		WARN_ON(rcu_access_pointer(dev->ip_ptr));
		WARN_ON(rcu_access_pointer(dev->ip6_ptr));
5926
		WARN_ON(dev->dn_ptr);
L
Linus Torvalds 已提交
5927

5928 5929
		if (dev->destructor)
			dev->destructor(dev);
5930 5931 5932

		/* Free network device */
		kobject_put(&dev->dev.kobj);
L
Linus Torvalds 已提交
5933 5934 5935
	}
}

5936 5937 5938
/* Convert net_device_stats to rtnl_link_stats64.  They have the same
 * fields in the same order, with only the type differing.
 */
5939 5940
void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
			     const struct net_device_stats *netdev_stats)
5941 5942
{
#if BITS_PER_LONG == 64
5943 5944
	BUILD_BUG_ON(sizeof(*stats64) != sizeof(*netdev_stats));
	memcpy(stats64, netdev_stats, sizeof(*stats64));
5945 5946 5947 5948 5949 5950 5951 5952 5953 5954 5955
#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
}
5956
EXPORT_SYMBOL(netdev_stats_to_stats64);
5957

5958 5959 5960
/**
 *	dev_get_stats	- get network device statistics
 *	@dev: device to get statistics from
5961
 *	@storage: place to store stats
5962
 *
5963 5964 5965 5966
 *	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.
5967
 */
5968 5969
struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
					struct rtnl_link_stats64 *storage)
5970
{
5971 5972
	const struct net_device_ops *ops = dev->netdev_ops;

5973 5974
	if (ops->ndo_get_stats64) {
		memset(storage, 0, sizeof(*storage));
5975 5976
		ops->ndo_get_stats64(dev, storage);
	} else if (ops->ndo_get_stats) {
5977
		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
5978 5979
	} else {
		netdev_stats_to_stats64(storage, &dev->stats);
5980
	}
5981
	storage->rx_dropped += atomic_long_read(&dev->rx_dropped);
5982
	return storage;
R
Rusty Russell 已提交
5983
}
5984
EXPORT_SYMBOL(dev_get_stats);
R
Rusty Russell 已提交
5985

5986
struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
5987
{
5988
	struct netdev_queue *queue = dev_ingress_queue(dev);
5989

5990 5991 5992 5993 5994 5995 5996 5997 5998 5999 6000 6001
#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;
6002 6003
}

6004 6005
static const struct ethtool_ops default_ethtool_ops;

6006 6007 6008 6009 6010 6011 6012 6013
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);

L
Linus Torvalds 已提交
6014
/**
T
Tom Herbert 已提交
6015
 *	alloc_netdev_mqs - allocate network device
L
Linus Torvalds 已提交
6016 6017 6018
 *	@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
6019 6020
 *	@txqs:		the number of TX subqueues to allocate
 *	@rxqs:		the number of RX subqueues to allocate
L
Linus Torvalds 已提交
6021 6022
 *
 *	Allocates a struct net_device with private data area for driver use
6023
 *	and performs basic initialization.  Also allocates subquue structs
T
Tom Herbert 已提交
6024
 *	for each queue on the device.
L
Linus Torvalds 已提交
6025
 */
T
Tom Herbert 已提交
6026 6027 6028
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
6029 6030
{
	struct net_device *dev;
6031
	size_t alloc_size;
6032
	struct net_device *p;
L
Linus Torvalds 已提交
6033

6034 6035
	BUG_ON(strlen(name) >= sizeof(dev->name));

T
Tom Herbert 已提交
6036
	if (txqs < 1) {
6037
		pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
6038 6039 6040
		return NULL;
	}

T
Tom Herbert 已提交
6041 6042
#ifdef CONFIG_RPS
	if (rxqs < 1) {
6043
		pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
T
Tom Herbert 已提交
6044 6045 6046 6047
		return NULL;
	}
#endif

6048
	alloc_size = sizeof(struct net_device);
6049 6050
	if (sizeof_priv) {
		/* ensure 32-byte alignment of private area */
6051
		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
6052 6053 6054
		alloc_size += sizeof_priv;
	}
	/* ensure 32-byte alignment of whole construct */
6055
	alloc_size += NETDEV_ALIGN - 1;
L
Linus Torvalds 已提交
6056

6057
	p = kzalloc(alloc_size, GFP_KERNEL);
6058
	if (!p)
L
Linus Torvalds 已提交
6059 6060
		return NULL;

6061
	dev = PTR_ALIGN(p, NETDEV_ALIGN);
L
Linus Torvalds 已提交
6062
	dev->padded = (char *)dev - (char *)p;
6063

E
Eric Dumazet 已提交
6064 6065
	dev->pcpu_refcnt = alloc_percpu(int);
	if (!dev->pcpu_refcnt)
6066
		goto free_p;
6067 6068

	if (dev_addr_init(dev))
E
Eric Dumazet 已提交
6069
		goto free_pcpu;
6070

6071
	dev_mc_init(dev);
6072
	dev_uc_init(dev);
J
Jiri Pirko 已提交
6073

6074
	dev_net_set(dev, &init_net);
L
Linus Torvalds 已提交
6075

6076
	dev->gso_max_size = GSO_MAX_SIZE;
6077
	dev->gso_max_segs = GSO_MAX_SEGS;
6078 6079 6080 6081

	INIT_LIST_HEAD(&dev->napi_list);
	INIT_LIST_HEAD(&dev->unreg_list);
	INIT_LIST_HEAD(&dev->link_watch_list);
J
Jiri Pirko 已提交
6082
	INIT_LIST_HEAD(&dev->upper_dev_list);
6083
	INIT_LIST_HEAD(&dev->lower_dev_list);
6084 6085 6086
	dev->priv_flags = IFF_XMIT_DST_RELEASE;
	setup(dev);

T
Tom Herbert 已提交
6087 6088
	dev->num_tx_queues = txqs;
	dev->real_num_tx_queues = txqs;
6089
	if (netif_alloc_netdev_queues(dev))
6090
		goto free_all;
6091

E
Eric Dumazet 已提交
6092
#ifdef CONFIG_RPS
T
Tom Herbert 已提交
6093 6094
	dev->num_rx_queues = rxqs;
	dev->real_num_rx_queues = rxqs;
T
Tom Herbert 已提交
6095
	if (netif_alloc_rx_queues(dev))
6096
		goto free_all;
E
Eric Dumazet 已提交
6097
#endif
T
Tom Herbert 已提交
6098

L
Linus Torvalds 已提交
6099
	strcpy(dev->name, name);
6100
	dev->group = INIT_NETDEV_GROUP;
6101 6102
	if (!dev->ethtool_ops)
		dev->ethtool_ops = &default_ethtool_ops;
L
Linus Torvalds 已提交
6103
	return dev;
6104

6105 6106 6107 6108
free_all:
	free_netdev(dev);
	return NULL;

E
Eric Dumazet 已提交
6109 6110
free_pcpu:
	free_percpu(dev->pcpu_refcnt);
6111
	netif_free_tx_queues(dev);
T
Tom Herbert 已提交
6112 6113 6114 6115
#ifdef CONFIG_RPS
	kfree(dev->_rx);
#endif

6116 6117 6118
free_p:
	kfree(p);
	return NULL;
L
Linus Torvalds 已提交
6119
}
T
Tom Herbert 已提交
6120
EXPORT_SYMBOL(alloc_netdev_mqs);
L
Linus Torvalds 已提交
6121 6122 6123 6124 6125

/**
 *	free_netdev - free network device
 *	@dev: device
 *
6126 6127
 *	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
6128 6129 6130 6131
 *	If this is the last reference then it will be freed.
 */
void free_netdev(struct net_device *dev)
{
6132 6133
	struct napi_struct *p, *n;

6134 6135
	release_net(dev_net(dev));

6136
	netif_free_tx_queues(dev);
T
Tom Herbert 已提交
6137 6138 6139
#ifdef CONFIG_RPS
	kfree(dev->_rx);
#endif
6140

6141
	kfree(rcu_dereference_protected(dev->ingress_queue, 1));
6142

6143 6144 6145
	/* Flush device addresses */
	dev_addr_flush(dev);

6146 6147 6148
	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
		netif_napi_del(p);

E
Eric Dumazet 已提交
6149 6150 6151
	free_percpu(dev->pcpu_refcnt);
	dev->pcpu_refcnt = NULL;

S
Stephen Hemminger 已提交
6152
	/*  Compatibility with error handling in drivers */
L
Linus Torvalds 已提交
6153 6154 6155 6156 6157 6158 6159 6160
	if (dev->reg_state == NETREG_UNINITIALIZED) {
		kfree((char *)dev - dev->padded);
		return;
	}

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

6161 6162
	/* will free via device release */
	put_device(&dev->dev);
L
Linus Torvalds 已提交
6163
}
E
Eric Dumazet 已提交
6164
EXPORT_SYMBOL(free_netdev);
6165

6166 6167 6168 6169 6170 6171
/**
 *	synchronize_net -  Synchronize with packet receive processing
 *
 *	Wait for packets currently being received to be done.
 *	Does not block later packets from starting.
 */
6172
void synchronize_net(void)
L
Linus Torvalds 已提交
6173 6174
{
	might_sleep();
6175 6176 6177 6178
	if (rtnl_is_locked())
		synchronize_rcu_expedited();
	else
		synchronize_rcu();
L
Linus Torvalds 已提交
6179
}
E
Eric Dumazet 已提交
6180
EXPORT_SYMBOL(synchronize_net);
L
Linus Torvalds 已提交
6181 6182

/**
6183
 *	unregister_netdevice_queue - remove device from the kernel
L
Linus Torvalds 已提交
6184
 *	@dev: device
6185
 *	@head: list
6186
 *
L
Linus Torvalds 已提交
6187
 *	This function shuts down a device interface and removes it
6188
 *	from the kernel tables.
6189
 *	If head not NULL, device is queued to be unregistered later.
L
Linus Torvalds 已提交
6190 6191 6192 6193 6194
 *
 *	Callers must hold the rtnl semaphore.  You may want
 *	unregister_netdev() instead of this.
 */

6195
void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
L
Linus Torvalds 已提交
6196
{
6197 6198
	ASSERT_RTNL();

6199
	if (head) {
6200
		list_move_tail(&dev->unreg_list, head);
6201 6202 6203 6204 6205
	} else {
		rollback_registered(dev);
		/* Finish processing unregister after unlock */
		net_set_todo(dev);
	}
L
Linus Torvalds 已提交
6206
}
6207
EXPORT_SYMBOL(unregister_netdevice_queue);
L
Linus Torvalds 已提交
6208

6209 6210 6211 6212 6213 6214 6215 6216 6217 6218 6219 6220 6221 6222
/**
 *	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);
	}
}
6223
EXPORT_SYMBOL(unregister_netdevice_many);
6224

L
Linus Torvalds 已提交
6225 6226 6227 6228 6229
/**
 *	unregister_netdev - remove device from the kernel
 *	@dev: device
 *
 *	This function shuts down a device interface and removes it
6230
 *	from the kernel tables.
L
Linus Torvalds 已提交
6231 6232 6233 6234 6235 6236 6237 6238 6239 6240 6241 6242 6243
 *
 *	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);

6244 6245 6246 6247 6248 6249 6250 6251 6252 6253 6254 6255 6256 6257 6258 6259 6260 6261 6262 6263 6264 6265 6266 6267 6268 6269 6270 6271 6272 6273 6274
/**
 *	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;
6275
	if (net_eq(dev_net(dev), net))
6276 6277 6278 6279 6280 6281
		goto out;

	/* Pick the destination device name, and ensure
	 * we can use it in the destination network namespace.
	 */
	err = -EEXIST;
6282
	if (__dev_get_by_name(net, dev->name)) {
6283 6284 6285
		/* We get here if we can't use the current device name */
		if (!pat)
			goto out;
6286
		if (dev_get_valid_name(net, dev, pat) < 0)
6287 6288 6289 6290 6291 6292 6293 6294
			goto out;
	}

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

	/* If device is running close it first. */
6295
	dev_close(dev);
6296 6297 6298 6299 6300 6301 6302 6303 6304 6305 6306 6307

	/* 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.
6308 6309 6310 6311

	   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.
6312 6313
	*/
	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
6314 6315
	rcu_barrier();
	call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
6316
	rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
6317 6318 6319 6320

	/*
	 *	Flush the unicast and multicast chains
	 */
6321
	dev_uc_flush(dev);
6322
	dev_mc_flush(dev);
6323

6324 6325 6326
	/* Send a netdev-removed uevent to the old namespace */
	kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);

6327
	/* Actually switch the network namespace */
6328
	dev_net_set(dev, net);
6329 6330 6331 6332 6333 6334 6335 6336 6337

	/* 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;
	}

6338 6339 6340
	/* Send a netdev-add uevent to the new namespace */
	kobject_uevent(&dev->dev.kobj, KOBJ_ADD);

6341
	/* Fixup kobjects */
6342
	err = device_rename(&dev->dev, dev->name);
6343
	WARN_ON(err);
6344 6345 6346 6347 6348 6349 6350

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

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

6351 6352 6353 6354 6355 6356
	/*
	 *	Prevent userspace races by waiting until the network
	 *	device is fully setup before sending notifications.
	 */
	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);

6357 6358 6359 6360 6361
	synchronize_net();
	err = 0;
out:
	return err;
}
6362
EXPORT_SYMBOL_GPL(dev_change_net_namespace);
6363

L
Linus Torvalds 已提交
6364 6365 6366 6367 6368 6369 6370 6371 6372
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;

6373
	if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
L
Linus Torvalds 已提交
6374 6375 6376 6377 6378 6379 6380 6381 6382 6383 6384 6385 6386 6387 6388 6389
		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. */
6390 6391 6392 6393 6394 6395
	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;
	}
6396 6397 6398 6399 6400
	/* 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
6401 6402 6403 6404 6405

	raise_softirq_irqoff(NET_TX_SOFTIRQ);
	local_irq_enable();

	/* Process offline CPU's input_pkt_queue */
6406
	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
L
Linus Torvalds 已提交
6407
		netif_rx(skb);
6408
		input_queue_head_incr(oldsd);
T
Tom Herbert 已提交
6409
	}
6410
	while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
6411
		netif_rx(skb);
6412 6413
		input_queue_head_incr(oldsd);
	}
L
Linus Torvalds 已提交
6414 6415 6416 6417 6418

	return NOTIFY_OK;
}


6419
/**
6420 6421 6422 6423
 *	netdev_increment_features - increment feature set by one
 *	@all: current feature set
 *	@one: new feature set
 *	@mask: mask feature set
6424 6425
 *
 *	Computes a new feature set after adding a device with feature set
6426 6427
 *	@one to the master device with current feature set @all.  Will not
 *	enable anything that is off in @mask. Returns the new feature set.
6428
 */
6429 6430
netdev_features_t netdev_increment_features(netdev_features_t all,
	netdev_features_t one, netdev_features_t mask)
6431
{
6432 6433 6434
	if (mask & NETIF_F_GEN_CSUM)
		mask |= NETIF_F_ALL_CSUM;
	mask |= NETIF_F_VLAN_CHALLENGED;
6435

6436 6437
	all |= one & (NETIF_F_ONE_FOR_ALL|NETIF_F_ALL_CSUM) & mask;
	all &= one | ~NETIF_F_ALL_FOR_ALL;
6438

6439 6440 6441
	/* If one device supports hw checksumming, set for all. */
	if (all & NETIF_F_GEN_CSUM)
		all &= ~(NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM);
6442 6443 6444

	return all;
}
6445
EXPORT_SYMBOL(netdev_increment_features);
6446

6447
static struct hlist_head * __net_init netdev_create_hash(void)
6448 6449 6450 6451 6452 6453 6454 6455 6456 6457 6458 6459
{
	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;
}

6460
/* Initialize per network namespace state */
6461
static int __net_init netdev_init(struct net *net)
6462
{
6463 6464
	if (net != &init_net)
		INIT_LIST_HEAD(&net->dev_base_head);
6465

6466 6467 6468
	net->dev_name_head = netdev_create_hash();
	if (net->dev_name_head == NULL)
		goto err_name;
6469

6470 6471 6472
	net->dev_index_head = netdev_create_hash();
	if (net->dev_index_head == NULL)
		goto err_idx;
6473 6474

	return 0;
6475 6476 6477 6478 6479

err_idx:
	kfree(net->dev_name_head);
err_name:
	return -ENOMEM;
6480 6481
}

6482 6483 6484 6485 6486 6487
/**
 *	netdev_drivername - network driver for the device
 *	@dev: network device
 *
 *	Determine network driver for device.
 */
6488
const char *netdev_drivername(const struct net_device *dev)
6489
{
6490 6491
	const struct device_driver *driver;
	const struct device *parent;
6492
	const char *empty = "";
6493 6494 6495

	parent = dev->dev.parent;
	if (!parent)
6496
		return empty;
6497 6498 6499

	driver = parent->driver;
	if (driver && driver->name)
6500 6501
		return driver->name;
	return empty;
6502 6503
}

6504
static int __netdev_printk(const char *level, const struct net_device *dev,
6505 6506 6507 6508
			   struct va_format *vaf)
{
	int r;

6509
	if (dev && dev->dev.parent) {
6510 6511 6512 6513 6514 6515
		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);
6516
	} else if (dev) {
6517
		r = printk("%s%s: %pV", level, netdev_name(dev), vaf);
6518
	} else {
6519
		r = printk("%s(NULL net_device): %pV", level, vaf);
6520
	}
6521 6522 6523 6524 6525 6526 6527 6528 6529 6530 6531 6532 6533 6534 6535 6536 6537

	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);
6538

6539 6540 6541 6542 6543 6544 6545 6546 6547 6548 6549 6550 6551 6552 6553 6554 6555 6556 6557
	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);			\
6558
								\
6559 6560 6561 6562 6563 6564 6565 6566 6567 6568 6569 6570 6571 6572
	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);

6573
static void __net_exit netdev_exit(struct net *net)
6574 6575 6576 6577 6578
{
	kfree(net->dev_name_head);
	kfree(net->dev_index_head);
}

6579
static struct pernet_operations __net_initdata netdev_net_ops = {
6580 6581 6582 6583
	.init = netdev_init,
	.exit = netdev_exit,
};

6584
static void __net_exit default_device_exit(struct net *net)
6585
{
6586
	struct net_device *dev, *aux;
6587
	/*
6588
	 * Push all migratable network devices back to the
6589 6590 6591
	 * initial network namespace
	 */
	rtnl_lock();
6592
	for_each_netdev_safe(net, dev, aux) {
6593
		int err;
6594
		char fb_name[IFNAMSIZ];
6595 6596 6597 6598 6599

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

6600 6601 6602
		/* Leave virtual devices for the generic cleanup */
		if (dev->rtnl_link_ops)
			continue;
6603

L
Lucas De Marchi 已提交
6604
		/* Push remaining network devices to init_net */
6605 6606
		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
		err = dev_change_net_namespace(dev, &init_net, fb_name);
6607
		if (err) {
6608 6609
			pr_emerg("%s: failed to move %s to init_net: %d\n",
				 __func__, dev->name, err);
6610
			BUG();
6611 6612 6613 6614 6615
		}
	}
	rtnl_unlock();
}

6616 6617 6618
static void __net_exit default_device_exit_batch(struct list_head *net_list)
{
	/* At exit all network devices most be removed from a network
6619
	 * namespace.  Do this in the reverse order of registration.
6620 6621 6622 6623 6624 6625 6626 6627 6628 6629 6630 6631 6632 6633 6634 6635 6636
	 * 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);

	rtnl_lock();
	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
6637
	list_del(&dev_kill_list);
6638 6639 6640
	rtnl_unlock();
}

6641
static struct pernet_operations __net_initdata default_device_ops = {
6642
	.exit = default_device_exit,
6643
	.exit_batch = default_device_exit_batch,
6644 6645
};

L
Linus Torvalds 已提交
6646 6647 6648 6649 6650 6651 6652 6653 6654 6655 6656 6657 6658 6659 6660 6661 6662 6663 6664 6665
/*
 *	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;

6666
	if (netdev_kobject_init())
L
Linus Torvalds 已提交
6667 6668 6669
		goto out;

	INIT_LIST_HEAD(&ptype_all);
6670
	for (i = 0; i < PTYPE_HASH_SIZE; i++)
L
Linus Torvalds 已提交
6671 6672
		INIT_LIST_HEAD(&ptype_base[i]);

6673 6674
	INIT_LIST_HEAD(&offload_base);

6675 6676
	if (register_pernet_subsys(&netdev_net_ops))
		goto out;
L
Linus Torvalds 已提交
6677 6678 6679 6680 6681

	/*
	 *	Initialise the packet receive queues.
	 */

6682
	for_each_possible_cpu(i) {
E
Eric Dumazet 已提交
6683
		struct softnet_data *sd = &per_cpu(softnet_data, i);
L
Linus Torvalds 已提交
6684

C
Changli Gao 已提交
6685
		memset(sd, 0, sizeof(*sd));
E
Eric Dumazet 已提交
6686
		skb_queue_head_init(&sd->input_pkt_queue);
6687
		skb_queue_head_init(&sd->process_queue);
E
Eric Dumazet 已提交
6688 6689
		sd->completion_queue = NULL;
		INIT_LIST_HEAD(&sd->poll_list);
6690 6691
		sd->output_queue = NULL;
		sd->output_queue_tailp = &sd->output_queue;
E
Eric Dumazet 已提交
6692
#ifdef CONFIG_RPS
E
Eric Dumazet 已提交
6693 6694 6695 6696
		sd->csd.func = rps_trigger_softirq;
		sd->csd.info = sd;
		sd->csd.flags = 0;
		sd->cpu = i;
6697
#endif
T
Tom Herbert 已提交
6698

E
Eric Dumazet 已提交
6699 6700 6701 6702
		sd->backlog.poll = process_backlog;
		sd->backlog.weight = weight_p;
		sd->backlog.gro_list = NULL;
		sd->backlog.gro_count = 0;
6703 6704 6705 6706

#ifdef CONFIG_NET_FLOW_LIMIT
		sd->flow_limit = NULL;
#endif
L
Linus Torvalds 已提交
6707 6708 6709 6710
	}

	dev_boot_phase = 0;

6711 6712 6713 6714 6715 6716 6717 6718 6719 6720 6721 6722 6723 6724 6725
	/* 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;

6726 6727
	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
L
Linus Torvalds 已提交
6728 6729 6730 6731 6732 6733 6734 6735 6736

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

subsys_initcall(net_dev_init);