dev.c 158.6 KB
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/*
 * 	NET3	Protocol independent device support routines.
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 *	Derived from the non IP parts of dev.c 1.0.19
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 * 		Authors:	Ross Biro
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 *				Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *				Mark Evans, <evansmp@uhura.aston.ac.uk>
 *
 *	Additional Authors:
 *		Florian la Roche <rzsfl@rz.uni-sb.de>
 *		Alan Cox <gw4pts@gw4pts.ampr.org>
 *		David Hinds <dahinds@users.sourceforge.net>
 *		Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
 *		Adam Sulmicki <adam@cfar.umd.edu>
 *              Pekka Riikonen <priikone@poesidon.pspt.fi>
 *
 *	Changes:
 *              D.J. Barrow     :       Fixed bug where dev->refcnt gets set
 *              			to 2 if register_netdev gets called
 *              			before net_dev_init & also removed a
 *              			few lines of code in the process.
 *		Alan Cox	:	device private ioctl copies fields back.
 *		Alan Cox	:	Transmit queue code does relevant
 *					stunts to keep the queue safe.
 *		Alan Cox	:	Fixed double lock.
 *		Alan Cox	:	Fixed promisc NULL pointer trap
 *		????????	:	Support the full private ioctl range
 *		Alan Cox	:	Moved ioctl permission check into
 *					drivers
 *		Tim Kordas	:	SIOCADDMULTI/SIOCDELMULTI
 *		Alan Cox	:	100 backlog just doesn't cut it when
 *					you start doing multicast video 8)
 *		Alan Cox	:	Rewrote net_bh and list manager.
 *		Alan Cox	: 	Fix ETH_P_ALL echoback lengths.
 *		Alan Cox	:	Took out transmit every packet pass
 *					Saved a few bytes in the ioctl handler
 *		Alan Cox	:	Network driver sets packet type before
 *					calling netif_rx. Saves a function
 *					call a packet.
 *		Alan Cox	:	Hashed net_bh()
 *		Richard Kooijman:	Timestamp fixes.
 *		Alan Cox	:	Wrong field in SIOCGIFDSTADDR
 *		Alan Cox	:	Device lock protection.
 *		Alan Cox	: 	Fixed nasty side effect of device close
 *					changes.
 *		Rudi Cilibrasi	:	Pass the right thing to
 *					set_mac_address()
 *		Dave Miller	:	32bit quantity for the device lock to
 *					make it work out on a Sparc.
 *		Bjorn Ekwall	:	Added KERNELD hack.
 *		Alan Cox	:	Cleaned up the backlog initialise.
 *		Craig Metz	:	SIOCGIFCONF fix if space for under
 *					1 device.
 *	    Thomas Bogendoerfer :	Return ENODEV for dev_open, if there
 *					is no device open function.
 *		Andi Kleen	:	Fix error reporting for SIOCGIFCONF
 *	    Michael Chastain	:	Fix signed/unsigned for SIOCGIFCONF
 *		Cyrus Durgin	:	Cleaned for KMOD
 *		Adam Sulmicki   :	Bug Fix : Network Device Unload
 *					A network device unload needs to purge
 *					the backlog queue.
 *	Paul Rusty Russell	:	SIOCSIFNAME
 *              Pekka Riikonen  :	Netdev boot-time settings code
 *              Andrew Morton   :       Make unregister_netdevice wait
 *              			indefinitely on dev->refcnt
 * 		J Hadi Salim	:	- Backlog queue sampling
 *				        - netif_rx() feedback
 */

#include <asm/uaccess.h>
#include <linux/bitops.h>
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#include <linux/capability.h>
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#include <linux/cpu.h>
#include <linux/types.h>
#include <linux/kernel.h>
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#include <linux/hash.h>
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#include <linux/slab.h>
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#include <linux/sched.h>
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#include <linux/mutex.h>
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#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/if_ether.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
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#include <linux/ethtool.h>
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#include <linux/notifier.h>
#include <linux/skbuff.h>
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#include <net/net_namespace.h>
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#include <net/sock.h>
#include <linux/rtnetlink.h>
#include <linux/stat.h>
#include <net/dst.h>
#include <net/pkt_sched.h>
#include <net/checksum.h>
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#include <net/xfrm.h>
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#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netpoll.h>
#include <linux/rcupdate.h>
#include <linux/delay.h>
#include <net/iw_handler.h>
#include <asm/current.h>
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#include <linux/audit.h>
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#include <linux/dmaengine.h>
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#include <linux/err.h>
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#include <linux/ctype.h>
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#include <linux/if_arp.h>
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#include <linux/if_vlan.h>
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#include <linux/ip.h>
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#include <net/ip.h>
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#include <linux/ipv6.h>
#include <linux/in.h>
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#include <linux/jhash.h>
#include <linux/random.h>
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#include <trace/events/napi.h>
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#include <trace/events/net.h>
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#include <trace/events/skb.h>
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#include <linux/pci.h>
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#include <linux/inetdevice.h>
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#include <linux/cpu_rmap.h>
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#include <linux/static_key.h>
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#include <linux/hashtable.h>
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#include "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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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));
548
			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] != ' ' &&
573
		    !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
583
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
	 */
608
	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
654
 *	@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.
 */

664
struct net_device *__dev_get_by_name(struct net *net, const char *name)
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{
E
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	struct net_device *dev;
	struct hlist_head *head = dev_name_hash(net, name);
L
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668

669
	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
675
EXPORT_SYMBOL(__dev_get_by_name);
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677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693
/**
 *	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);

694
	hlist_for_each_entry_rcu(dev, head, name_hlist)
695 696 697 698 699 700 701
		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
704
 *	@net: the applicable net namespace
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705 706 707 708 709 710 711 712 713
 *	@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.
 */

714
struct net_device *dev_get_by_name(struct net *net, const char *name)
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{
	struct net_device *dev;

718 719
	rcu_read_lock();
	dev = dev_get_by_name_rcu(net, name);
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	if (dev)
		dev_hold(dev);
722
	rcu_read_unlock();
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723 724
	return dev;
}
E
Eric Dumazet 已提交
725
EXPORT_SYMBOL(dev_get_by_name);
L
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726 727 728

/**
 *	__dev_get_by_index - find a device by its ifindex
729
 *	@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.
 */

739
struct net_device *__dev_get_by_index(struct net *net, int ifindex)
L
Linus Torvalds 已提交
740
{
E
Eric Dumazet 已提交
741 742
	struct net_device *dev;
	struct hlist_head *head = dev_index_hash(net, ifindex);
L
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743

744
	hlist_for_each_entry(dev, head, index_hlist)
L
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745 746
		if (dev->ifindex == ifindex)
			return dev;
E
Eric Dumazet 已提交
747

L
Linus Torvalds 已提交
748 749
	return NULL;
}
E
Eric Dumazet 已提交
750
EXPORT_SYMBOL(__dev_get_by_index);
L
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751

752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767
/**
 *	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);

768
	hlist_for_each_entry_rcu(dev, head, index_hlist)
769 770 771 772 773 774 775
		if (dev->ifindex == ifindex)
			return dev;

	return NULL;
}
EXPORT_SYMBOL(dev_get_by_index_rcu);

L
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776 777 778

/**
 *	dev_get_by_index - find a device by its ifindex
779
 *	@net: the applicable net namespace
L
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780 781 782 783 784 785 786 787
 *	@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.
 */

788
struct net_device *dev_get_by_index(struct net *net, int ifindex)
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789 790 791
{
	struct net_device *dev;

792 793
	rcu_read_lock();
	dev = dev_get_by_index_rcu(net, ifindex);
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794 795
	if (dev)
		dev_hold(dev);
796
	rcu_read_unlock();
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797 798
	return dev;
}
E
Eric Dumazet 已提交
799
EXPORT_SYMBOL(dev_get_by_index);
L
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800 801

/**
802
 *	dev_getbyhwaddr_rcu - find a device by its hardware address
803
 *	@net: the applicable net namespace
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804 805 806 807
 *	@type: media type of device
 *	@ha: hardware address
 *
 *	Search for an interface by MAC address. Returns NULL if the device
E
Eric Dumazet 已提交
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 *	is not found or a pointer to the device.
 *	The caller must hold RCU or RTNL.
810
 *	The returned device has not had its ref count increased
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811 812 813 814
 *	and the caller must therefore be careful about locking
 *
 */

815 816
struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
				       const char *ha)
L
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817 818 819
{
	struct net_device *dev;

820
	for_each_netdev_rcu(net, dev)
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821 822
		if (dev->type == type &&
		    !memcmp(dev->dev_addr, ha, dev->addr_len))
823 824 825
			return dev;

	return NULL;
L
Linus Torvalds 已提交
826
}
827
EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
828

829
struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type)
L
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830 831 832
{
	struct net_device *dev;

833
	ASSERT_RTNL();
834
	for_each_netdev(net, dev)
835
		if (dev->type == type)
836 837 838
			return dev;

	return NULL;
839 840 841
}
EXPORT_SYMBOL(__dev_getfirstbyhwtype);

842
struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
843
{
844
	struct net_device *dev, *ret = NULL;
845

846 847 848 849 850 851 852 853 854
	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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855 856 857 858
}
EXPORT_SYMBOL(dev_getfirstbyhwtype);

/**
E
Eric Dumazet 已提交
859
 *	dev_get_by_flags_rcu - find any device with given flags
860
 *	@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
865 866
 *	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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867 868
 */

E
Eric Dumazet 已提交
869
struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags,
E
Eric Dumazet 已提交
870
				    unsigned short mask)
L
Linus Torvalds 已提交
871
{
872
	struct net_device *dev, *ret;
L
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873

874
	ret = NULL;
875
	for_each_netdev_rcu(net, dev) {
L
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876
		if (((dev->flags ^ if_flags) & mask) == 0) {
877
			ret = dev;
L
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878 879 880
			break;
		}
	}
881
	return ret;
L
Linus Torvalds 已提交
882
}
E
Eric Dumazet 已提交
883
EXPORT_SYMBOL(dev_get_by_flags_rcu);
L
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884 885 886 887 888 889

/**
 *	dev_valid_name - check if name is okay for network device
 *	@name: name string
 *
 *	Network device names need to be valid file names to
890 891
 *	to allow sysfs to work.  We also disallow any kind of
 *	whitespace.
L
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892
 */
893
bool dev_valid_name(const char *name)
L
Linus Torvalds 已提交
894
{
895
	if (*name == '\0')
896
		return false;
897
	if (strlen(name) >= IFNAMSIZ)
898
		return false;
899
	if (!strcmp(name, ".") || !strcmp(name, ".."))
900
		return false;
901 902 903

	while (*name) {
		if (*name == '/' || isspace(*name))
904
			return false;
905 906
		name++;
	}
907
	return true;
L
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908
}
E
Eric Dumazet 已提交
909
EXPORT_SYMBOL(dev_valid_name);
L
Linus Torvalds 已提交
910 911

/**
912 913
 *	__dev_alloc_name - allocate a name for a device
 *	@net: network namespace to allocate the device name in
L
Linus Torvalds 已提交
914
 *	@name: name format string
915
 *	@buf:  scratch buffer and result name string
L
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916 917
 *
 *	Passed a format string - eg "lt%d" it will try and find a suitable
S
Stephen Hemminger 已提交
918 919 920 921 922 923
 *	id. It scans list of devices to build up a free map, then chooses
 *	the first empty slot. The caller must hold the dev_base or rtnl lock
 *	while allocating the name and adding the device in order to avoid
 *	duplicates.
 *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
 *	Returns the number of the unit assigned or a negative errno code.
L
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924 925
 */

926
static int __dev_alloc_name(struct net *net, const char *name, char *buf)
L
Linus Torvalds 已提交
927 928 929 930
{
	int i = 0;
	const char *p;
	const int max_netdevices = 8*PAGE_SIZE;
S
Stephen Hemminger 已提交
931
	unsigned long *inuse;
L
Linus Torvalds 已提交
932 933 934 935 936 937 938 939 940 941 942 943 944
	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
945
		inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
L
Linus Torvalds 已提交
946 947 948
		if (!inuse)
			return -ENOMEM;

949
		for_each_netdev(net, d) {
L
Linus Torvalds 已提交
950 951 952 953 954 955
			if (!sscanf(d->name, name, &i))
				continue;
			if (i < 0 || i >= max_netdevices)
				continue;

			/*  avoid cases where sscanf is not exact inverse of printf */
956
			snprintf(buf, IFNAMSIZ, name, i);
L
Linus Torvalds 已提交
957 958 959 960 961 962 963 964
			if (!strncmp(buf, d->name, IFNAMSIZ))
				set_bit(i, inuse);
		}

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

965 966
	if (buf != name)
		snprintf(buf, IFNAMSIZ, name, i);
967
	if (!__dev_get_by_name(net, buf))
L
Linus Torvalds 已提交
968 969 970 971 972 973 974 975 976
		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;
}

977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996
/**
 *	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;

997 998
	BUG_ON(!dev_net(dev));
	net = dev_net(dev);
999 1000 1001 1002 1003
	ret = __dev_alloc_name(net, name, buf);
	if (ret >= 0)
		strlcpy(dev->name, buf, IFNAMSIZ);
	return ret;
}
E
Eric Dumazet 已提交
1004
EXPORT_SYMBOL(dev_alloc_name);
1005

1006 1007 1008
static int dev_alloc_name_ns(struct net *net,
			     struct net_device *dev,
			     const char *name)
1009
{
1010 1011
	char buf[IFNAMSIZ];
	int ret;
1012

1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023
	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);
1024

1025 1026 1027
	if (!dev_valid_name(name))
		return -EINVAL;

1028
	if (strchr(name, '%'))
1029
		return dev_alloc_name_ns(net, dev, name);
1030 1031
	else if (__dev_get_by_name(net, name))
		return -EEXIST;
1032 1033
	else if (dev->name != name)
		strlcpy(dev->name, name, IFNAMSIZ);
1034 1035 1036

	return 0;
}
L
Linus Torvalds 已提交
1037 1038 1039 1040 1041 1042 1043 1044 1045

/**
 *	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.
 */
1046
int dev_change_name(struct net_device *dev, const char *newname)
L
Linus Torvalds 已提交
1047
{
1048
	char oldname[IFNAMSIZ];
L
Linus Torvalds 已提交
1049
	int err = 0;
1050
	int ret;
1051
	struct net *net;
L
Linus Torvalds 已提交
1052 1053

	ASSERT_RTNL();
1054
	BUG_ON(!dev_net(dev));
L
Linus Torvalds 已提交
1055

1056
	net = dev_net(dev);
L
Linus Torvalds 已提交
1057 1058 1059
	if (dev->flags & IFF_UP)
		return -EBUSY;

1060
	write_seqcount_begin(&devnet_rename_seq);
1061 1062

	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1063
		write_seqcount_end(&devnet_rename_seq);
1064
		return 0;
1065
	}
1066

1067 1068
	memcpy(oldname, dev->name, IFNAMSIZ);

1069
	err = dev_get_valid_name(net, dev, newname);
1070
	if (err < 0) {
1071
		write_seqcount_end(&devnet_rename_seq);
1072
		return err;
1073
	}
L
Linus Torvalds 已提交
1074

1075
rollback:
1076 1077 1078
	ret = device_rename(&dev->dev, dev->name);
	if (ret) {
		memcpy(dev->name, oldname, IFNAMSIZ);
1079
		write_seqcount_end(&devnet_rename_seq);
1080
		return ret;
1081
	}
1082

1083
	write_seqcount_end(&devnet_rename_seq);
1084

1085
	write_lock_bh(&dev_base_lock);
1086
	hlist_del_rcu(&dev->name_hlist);
1087 1088 1089 1090 1091 1092
	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));
1093 1094
	write_unlock_bh(&dev_base_lock);

1095
	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1096 1097 1098
	ret = notifier_to_errno(ret);

	if (ret) {
1099 1100
		/* err >= 0 after dev_alloc_name() or stores the first errno */
		if (err >= 0) {
1101
			err = ret;
1102
			write_seqcount_begin(&devnet_rename_seq);
1103 1104
			memcpy(dev->name, oldname, IFNAMSIZ);
			goto rollback;
1105
		} else {
1106
			pr_err("%s: name change rollback failed: %d\n",
1107
			       dev->name, ret);
1108 1109
		}
	}
L
Linus Torvalds 已提交
1110 1111 1112 1113

	return err;
}

1114 1115 1116 1117
/**
 *	dev_set_alias - change ifalias of a device
 *	@dev: device
 *	@alias: name up to IFALIASZ
1118
 *	@len: limit of bytes to copy from info
1119 1120 1121 1122 1123
 *
 *	Set ifalias for a device,
 */
int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
{
1124 1125
	char *new_ifalias;

1126 1127 1128 1129 1130
	ASSERT_RTNL();

	if (len >= IFALIASZ)
		return -EINVAL;

1131
	if (!len) {
1132 1133
		kfree(dev->ifalias);
		dev->ifalias = NULL;
1134 1135 1136
		return 0;
	}

1137 1138
	new_ifalias = krealloc(dev->ifalias, len + 1, GFP_KERNEL);
	if (!new_ifalias)
1139
		return -ENOMEM;
1140
	dev->ifalias = new_ifalias;
1141 1142 1143 1144 1145 1146

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


1147
/**
S
Stephen Hemminger 已提交
1148
 *	netdev_features_change - device changes features
1149 1150 1151 1152 1153 1154
 *	@dev: device to cause notification
 *
 *	Called to indicate a device has changed features.
 */
void netdev_features_change(struct net_device *dev)
{
1155
	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1156 1157 1158
}
EXPORT_SYMBOL(netdev_features_change);

L
Linus Torvalds 已提交
1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169
/**
 *	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) {
1170
		call_netdevice_notifiers(NETDEV_CHANGE, dev);
L
Linus Torvalds 已提交
1171 1172 1173
		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
	}
}
E
Eric Dumazet 已提交
1174
EXPORT_SYMBOL(netdev_state_change);
L
Linus Torvalds 已提交
1175

1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186
/**
 * 	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)
1187
{
1188 1189 1190
	rtnl_lock();
	call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
	rtnl_unlock();
1191
}
1192
EXPORT_SYMBOL(netdev_notify_peers);
1193

1194
static int __dev_open(struct net_device *dev)
L
Linus Torvalds 已提交
1195
{
1196
	const struct net_device_ops *ops = dev->netdev_ops;
1197
	int ret;
L
Linus Torvalds 已提交
1198

1199 1200
	ASSERT_RTNL();

L
Linus Torvalds 已提交
1201 1202 1203
	if (!netif_device_present(dev))
		return -ENODEV;

1204 1205 1206 1207
	/* 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
	 */
1208
	netpoll_rx_disable(dev);
1209

1210 1211 1212 1213 1214
	ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
	ret = notifier_to_errno(ret);
	if (ret)
		return ret;

L
Linus Torvalds 已提交
1215
	set_bit(__LINK_STATE_START, &dev->state);
1216

1217 1218
	if (ops->ndo_validate_addr)
		ret = ops->ndo_validate_addr(dev);
1219

1220 1221
	if (!ret && ops->ndo_open)
		ret = ops->ndo_open(dev);
L
Linus Torvalds 已提交
1222

1223 1224
	netpoll_rx_enable(dev);

1225 1226 1227
	if (ret)
		clear_bit(__LINK_STATE_START, &dev->state);
	else {
L
Linus Torvalds 已提交
1228
		dev->flags |= IFF_UP;
1229
		net_dmaengine_get();
1230
		dev_set_rx_mode(dev);
L
Linus Torvalds 已提交
1231
		dev_activate(dev);
1232
		add_device_randomness(dev->dev_addr, dev->addr_len);
L
Linus Torvalds 已提交
1233
	}
1234

L
Linus Torvalds 已提交
1235 1236 1237 1238
	return ret;
}

/**
1239 1240
 *	dev_open	- prepare an interface for use.
 *	@dev:	device to open
L
Linus Torvalds 已提交
1241
 *
1242 1243 1244 1245 1246 1247 1248
 *	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
1249
 */
1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267
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);

1268
static int __dev_close_many(struct list_head *head)
L
Linus Torvalds 已提交
1269
{
1270
	struct net_device *dev;
1271

1272
	ASSERT_RTNL();
1273 1274
	might_sleep();

1275 1276
	list_for_each_entry(dev, head, unreg_list) {
		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
L
Linus Torvalds 已提交
1277

1278
		clear_bit(__LINK_STATE_START, &dev->state);
L
Linus Torvalds 已提交
1279

1280 1281 1282 1283 1284 1285 1286 1287
		/* 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
1288

1289
	dev_deactivate_many(head);
1290

1291 1292
	list_for_each_entry(dev, head, unreg_list) {
		const struct net_device_ops *ops = dev->netdev_ops;
L
Linus Torvalds 已提交
1293

1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312
		/*
		 *	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)
{
1313
	int retval;
1314 1315
	LIST_HEAD(single);

1316
	/* Temporarily disable netpoll until the interface is down */
1317
	netpoll_rx_disable(dev);
1318

1319
	list_add(&dev->unreg_list, &single);
1320 1321
	retval = __dev_close_many(&single);
	list_del(&single);
1322 1323

	netpoll_rx_enable(dev);
1324
	return retval;
1325 1326
}

E
Eric Dumazet 已提交
1327
static int dev_close_many(struct list_head *head)
1328 1329 1330
{
	struct net_device *dev, *tmp;
	LIST_HEAD(tmp_list);
L
Linus Torvalds 已提交
1331

1332 1333 1334 1335 1336
	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
1337

1338 1339 1340 1341
	list_for_each_entry(dev, head, unreg_list) {
		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
		call_netdevice_notifiers(NETDEV_DOWN, dev);
	}
1342

1343 1344
	/* rollback_registered_many needs the complete original list */
	list_splice(&tmp_list, head);
1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358
	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)
{
1359 1360
	if (dev->flags & IFF_UP) {
		LIST_HEAD(single);
L
Linus Torvalds 已提交
1361

1362
		/* Block netpoll rx while the interface is going down */
1363
		netpoll_rx_disable(dev);
1364

1365 1366 1367
		list_add(&dev->unreg_list, &single);
		dev_close_many(&single);
		list_del(&single);
1368 1369

		netpoll_rx_enable(dev);
1370
	}
1371
	return 0;
L
Linus Torvalds 已提交
1372
}
E
Eric Dumazet 已提交
1373
EXPORT_SYMBOL(dev_close);
L
Linus Torvalds 已提交
1374 1375


1376 1377 1378 1379 1380 1381 1382 1383 1384 1385
/**
 *	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)
{
1386 1387 1388 1389 1390 1391 1392
	/*
	 * 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
1393 1394
	dev->wanted_features &= ~NETIF_F_LRO;
	netdev_update_features(dev);
1395

1396 1397
	if (unlikely(dev->features & NETIF_F_LRO))
		netdev_WARN(dev, "failed to disable LRO!\n");
1398 1399 1400
}
EXPORT_SYMBOL(dev_disable_lro);

1401 1402 1403 1404 1405 1406 1407 1408
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);
}
1409

1410 1411
static int dev_boot_phase = 1;

L
Linus Torvalds 已提交
1412 1413 1414 1415 1416 1417 1418 1419 1420 1421
/**
 *	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
1422
 *	to the new notifier to allow device to have a race free
L
Linus Torvalds 已提交
1423 1424 1425 1426 1427 1428
 *	view of the network device list.
 */

int register_netdevice_notifier(struct notifier_block *nb)
{
	struct net_device *dev;
1429
	struct net_device *last;
1430
	struct net *net;
L
Linus Torvalds 已提交
1431 1432 1433
	int err;

	rtnl_lock();
1434
	err = raw_notifier_chain_register(&netdev_chain, nb);
1435 1436
	if (err)
		goto unlock;
1437 1438 1439 1440
	if (dev_boot_phase)
		goto unlock;
	for_each_net(net) {
		for_each_netdev(net, dev) {
1441
			err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1442 1443 1444 1445 1446 1447
			err = notifier_to_errno(err);
			if (err)
				goto rollback;

			if (!(dev->flags & IFF_UP))
				continue;
L
Linus Torvalds 已提交
1448

1449
			call_netdevice_notifier(nb, NETDEV_UP, dev);
1450
		}
L
Linus Torvalds 已提交
1451
	}
1452 1453

unlock:
L
Linus Torvalds 已提交
1454 1455
	rtnl_unlock();
	return err;
1456 1457 1458

rollback:
	last = dev;
1459 1460 1461
	for_each_net(net) {
		for_each_netdev(net, dev) {
			if (dev == last)
1462
				goto outroll;
1463

1464
			if (dev->flags & IFF_UP) {
1465 1466 1467
				call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
							dev);
				call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1468
			}
1469
			call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1470 1471
		}
	}
1472

1473
outroll:
1474
	raw_notifier_chain_unregister(&netdev_chain, nb);
1475
	goto unlock;
L
Linus Torvalds 已提交
1476
}
E
Eric Dumazet 已提交
1477
EXPORT_SYMBOL(register_netdevice_notifier);
L
Linus Torvalds 已提交
1478 1479 1480 1481 1482 1483 1484 1485 1486

/**
 *	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.
1487 1488 1489 1490
 *
 * 	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
1491 1492 1493 1494
 */

int unregister_netdevice_notifier(struct notifier_block *nb)
{
1495 1496
	struct net_device *dev;
	struct net *net;
1497 1498 1499
	int err;

	rtnl_lock();
1500
	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1501 1502 1503 1504 1505 1506
	if (err)
		goto unlock;

	for_each_net(net) {
		for_each_netdev(net, dev) {
			if (dev->flags & IFF_UP) {
1507 1508 1509
				call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
							dev);
				call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1510
			}
1511
			call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1512 1513 1514
		}
	}
unlock:
1515 1516
	rtnl_unlock();
	return err;
L
Linus Torvalds 已提交
1517
}
E
Eric Dumazet 已提交
1518
EXPORT_SYMBOL(unregister_netdevice_notifier);
L
Linus Torvalds 已提交
1519

1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538
/**
 *	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
1539 1540 1541
/**
 *	call_netdevice_notifiers - call all network notifier blocks
 *      @val: value passed unmodified to notifier function
1542
 *      @dev: net_device pointer passed unmodified to notifier function
L
Linus Torvalds 已提交
1543 1544
 *
 *	Call all network notifier blocks.  Parameters and return value
1545
 *	are as for raw_notifier_call_chain().
L
Linus Torvalds 已提交
1546 1547
 */

1548
int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
L
Linus Torvalds 已提交
1549
{
1550 1551 1552
	struct netdev_notifier_info info;

	return call_netdevice_notifiers_info(val, dev, &info);
L
Linus Torvalds 已提交
1553
}
1554
EXPORT_SYMBOL(call_netdevice_notifiers);
L
Linus Torvalds 已提交
1555

1556
static struct static_key netstamp_needed __read_mostly;
1557
#ifdef HAVE_JUMP_LABEL
1558
/* We are not allowed to call static_key_slow_dec() from irq context
1559
 * If net_disable_timestamp() is called from irq context, defer the
1560
 * static_key_slow_dec() calls.
1561 1562 1563
 */
static atomic_t netstamp_needed_deferred;
#endif
L
Linus Torvalds 已提交
1564 1565 1566

void net_enable_timestamp(void)
{
1567 1568 1569 1570 1571
#ifdef HAVE_JUMP_LABEL
	int deferred = atomic_xchg(&netstamp_needed_deferred, 0);

	if (deferred) {
		while (--deferred)
1572
			static_key_slow_dec(&netstamp_needed);
1573 1574 1575
		return;
	}
#endif
1576
	static_key_slow_inc(&netstamp_needed);
L
Linus Torvalds 已提交
1577
}
E
Eric Dumazet 已提交
1578
EXPORT_SYMBOL(net_enable_timestamp);
L
Linus Torvalds 已提交
1579 1580 1581

void net_disable_timestamp(void)
{
1582 1583 1584 1585 1586 1587
#ifdef HAVE_JUMP_LABEL
	if (in_interrupt()) {
		atomic_inc(&netstamp_needed_deferred);
		return;
	}
#endif
1588
	static_key_slow_dec(&netstamp_needed);
L
Linus Torvalds 已提交
1589
}
E
Eric Dumazet 已提交
1590
EXPORT_SYMBOL(net_disable_timestamp);
L
Linus Torvalds 已提交
1591

E
Eric Dumazet 已提交
1592
static inline void net_timestamp_set(struct sk_buff *skb)
L
Linus Torvalds 已提交
1593
{
1594
	skb->tstamp.tv64 = 0;
1595
	if (static_key_false(&netstamp_needed))
1596
		__net_timestamp(skb);
L
Linus Torvalds 已提交
1597 1598
}

1599
#define net_timestamp_check(COND, SKB)			\
1600
	if (static_key_false(&netstamp_needed)) {		\
1601 1602 1603
		if ((COND) && !(SKB)->tstamp.tv64)	\
			__net_timestamp(SKB);		\
	}						\
E
Eric Dumazet 已提交
1604

1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625
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;
}

1626 1627 1628 1629 1630 1631 1632 1633
/**
 * dev_forward_skb - loopback an skb to another netif
 *
 * @dev: destination network device
 * @skb: buffer to forward
 *
 * return values:
 *	NET_RX_SUCCESS	(no congestion)
1634
 *	NET_RX_DROP     (packet was dropped, but freed)
1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645
 *
 * 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)
{
1646 1647 1648 1649 1650 1651 1652 1653
	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;
		}
	}

1654 1655
	skb_orphan(skb);

1656
	if (unlikely(!is_skb_forwardable(dev, skb))) {
1657
		atomic_long_inc(&dev->rx_dropped);
1658
		kfree_skb(skb);
1659
		return NET_RX_DROP;
1660
	}
1661
	skb->skb_iif = 0;
1662
	skb_dst_drop(skb);
1663 1664 1665
	skb->tstamp.tv64 = 0;
	skb->pkt_type = PACKET_HOST;
	skb->protocol = eth_type_trans(skb, dev);
1666 1667 1668
	skb->mark = 0;
	secpath_reset(skb);
	nf_reset(skb);
1669
	nf_reset_trace(skb);
1670 1671 1672 1673
	return netif_rx(skb);
}
EXPORT_SYMBOL_GPL(dev_forward_skb);

1674 1675 1676 1677
static inline int deliver_skb(struct sk_buff *skb,
			      struct packet_type *pt_prev,
			      struct net_device *orig_dev)
{
1678 1679
	if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
		return -ENOMEM;
1680 1681 1682 1683
	atomic_inc(&skb->users);
	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
}

1684 1685
static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
{
1686
	if (!ptype->af_packet_priv || !skb->sk)
1687 1688 1689 1690 1691 1692 1693 1694 1695 1696
		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
1697 1698 1699 1700 1701
/*
 *	Support routine. Sends outgoing frames to any network
 *	taps currently in use.
 */

1702
static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
L
Linus Torvalds 已提交
1703 1704
{
	struct packet_type *ptype;
1705 1706
	struct sk_buff *skb2 = NULL;
	struct packet_type *pt_prev = NULL;
1707

L
Linus Torvalds 已提交
1708 1709 1710 1711 1712 1713
	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) &&
1714
		    (!skb_loop_sk(ptype, skb))) {
1715 1716 1717 1718 1719 1720 1721
			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
1722 1723 1724
			if (!skb2)
				break;

1725 1726
			net_timestamp_set(skb2);

L
Linus Torvalds 已提交
1727 1728 1729 1730
			/* skb->nh should be correctly
			   set by sender, so that the second statement is
			   just protection against buggy protocols.
			 */
1731
			skb_reset_mac_header(skb2);
L
Linus Torvalds 已提交
1732

1733
			if (skb_network_header(skb2) < skb2->data ||
1734
			    skb_network_header(skb2) > skb_tail_pointer(skb2)) {
1735 1736 1737
				net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
						     ntohs(skb2->protocol),
						     dev->name);
1738
				skb_reset_network_header(skb2);
L
Linus Torvalds 已提交
1739 1740
			}

1741
			skb2->transport_header = skb2->network_header;
L
Linus Torvalds 已提交
1742
			skb2->pkt_type = PACKET_OUTGOING;
1743
			pt_prev = ptype;
L
Linus Torvalds 已提交
1744 1745
		}
	}
1746 1747
	if (pt_prev)
		pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
L
Linus Torvalds 已提交
1748 1749 1750
	rcu_read_unlock();
}

1751 1752
/**
 * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763
 * @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
1764
static void netif_setup_tc(struct net_device *dev, unsigned int txq)
1765 1766 1767 1768 1769 1770
{
	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) {
1771
		pr_warn("Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
1772 1773 1774 1775 1776 1777 1778 1779 1780 1781
		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) {
1782 1783
			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);
1784 1785 1786 1787 1788
			netdev_set_prio_tc_map(dev, i, 0);
		}
	}
}

1789 1790 1791 1792 1793
#ifdef CONFIG_XPS
static DEFINE_MUTEX(xps_map_mutex);
#define xmap_dereference(P)		\
	rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))

1794 1795
static struct xps_map *remove_xps_queue(struct xps_dev_maps *dev_maps,
					int cpu, u16 index)
1796
{
1797 1798
	struct xps_map *map = NULL;
	int pos;
1799

1800 1801
	if (dev_maps)
		map = xmap_dereference(dev_maps->cpu_map[cpu]);
1802

1803 1804
	for (pos = 0; map && pos < map->len; pos++) {
		if (map->queues[pos] == index) {
1805 1806 1807
			if (map->len > 1) {
				map->queues[pos] = map->queues[--map->len];
			} else {
1808
				RCU_INIT_POINTER(dev_maps->cpu_map[cpu], NULL);
1809 1810 1811
				kfree_rcu(map, rcu);
				map = NULL;
			}
1812
			break;
1813 1814 1815
		}
	}

1816 1817 1818
	return map;
}

1819
static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
1820 1821
{
	struct xps_dev_maps *dev_maps;
1822
	int cpu, i;
1823 1824 1825 1826 1827 1828 1829 1830 1831
	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) {
1832 1833 1834 1835 1836
		for (i = index; i < dev->num_tx_queues; i++) {
			if (!remove_xps_queue(dev_maps, cpu, i))
				break;
		}
		if (i == dev->num_tx_queues)
1837 1838 1839 1840
			active = true;
	}

	if (!active) {
1841 1842 1843 1844
		RCU_INIT_POINTER(dev->xps_maps, NULL);
		kfree_rcu(dev_maps, rcu);
	}

1845 1846 1847 1848
	for (i = index; i < dev->num_tx_queues; i++)
		netdev_queue_numa_node_write(netdev_get_tx_queue(dev, i),
					     NUMA_NO_NODE);

1849 1850 1851 1852
out_no_maps:
	mutex_unlock(&xps_map_mutex);
}

1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887
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;
}

1888 1889
int netif_set_xps_queue(struct net_device *dev, struct cpumask *mask, u16 index)
{
1890
	struct xps_dev_maps *dev_maps, *new_dev_maps = NULL;
1891 1892
	struct xps_map *map, *new_map;
	int maps_sz = max_t(unsigned int, XPS_DEV_MAPS_SIZE, L1_CACHE_BYTES);
1893 1894
	int cpu, numa_node_id = -2;
	bool active = false;
1895 1896 1897 1898 1899

	mutex_lock(&xps_map_mutex);

	dev_maps = xmap_dereference(dev->xps_maps);

1900 1901 1902 1903 1904 1905 1906
	/* 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);
1907 1908
		if (!new_dev_maps) {
			mutex_unlock(&xps_map_mutex);
1909
			return -ENOMEM;
1910
		}
1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924

		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;

1925
	for_each_possible_cpu(cpu) {
1926 1927 1928 1929 1930 1931 1932 1933 1934 1935
		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;
1936 1937 1938 1939 1940 1941
#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
1942 1943 1944 1945
		} 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);
1946
		}
1947

1948 1949
	}

1950 1951
	rcu_assign_pointer(dev->xps_maps, new_dev_maps);

1952
	/* Cleanup old maps */
1953 1954 1955 1956 1957 1958 1959
	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);
		}
1960

1961
		kfree_rcu(dev_maps, rcu);
1962 1963
	}

1964 1965
	dev_maps = new_dev_maps;
	active = true;
1966

1967 1968
out_no_new_maps:
	/* update Tx queue numa node */
1969 1970 1971 1972
	netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
				     (numa_node_id >= 0) ? numa_node_id :
				     NUMA_NO_NODE);

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991
	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:
1992 1993 1994 1995
	mutex_unlock(&xps_map_mutex);

	return 0;
error:
1996 1997 1998 1999 2000 2001 2002 2003 2004
	/* 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);
	}

2005 2006 2007 2008 2009 2010 2011 2012
	mutex_unlock(&xps_map_mutex);

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

#endif
2013 2014 2015 2016
/*
 * 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.
 */
2017
int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2018
{
T
Tom Herbert 已提交
2019 2020
	int rc;

2021 2022
	if (txq < 1 || txq > dev->num_tx_queues)
		return -EINVAL;
2023

2024 2025
	if (dev->reg_state == NETREG_REGISTERED ||
	    dev->reg_state == NETREG_UNREGISTERING) {
2026 2027
		ASSERT_RTNL();

T
Tom Herbert 已提交
2028 2029
		rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
						  txq);
T
Tom Herbert 已提交
2030 2031 2032
		if (rc)
			return rc;

2033 2034 2035
		if (dev->num_tc)
			netif_setup_tc(dev, txq);

2036
		if (txq < dev->real_num_tx_queues) {
2037
			qdisc_reset_all_tx_gt(dev, txq);
2038 2039 2040 2041
#ifdef CONFIG_XPS
			netif_reset_xps_queues_gt(dev, txq);
#endif
		}
2042
	}
2043 2044 2045

	dev->real_num_tx_queues = txq;
	return 0;
2046 2047
}
EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2048

2049 2050 2051 2052 2053 2054 2055 2056
#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
2057 2058
 *	negative error code.  If called before registration, it always
 *	succeeds.
2059 2060 2061 2062 2063
 */
int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
{
	int rc;

T
Tom Herbert 已提交
2064 2065 2066
	if (rxq < 1 || rxq > dev->num_rx_queues)
		return -EINVAL;

2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081
	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

2082 2083
/**
 * netif_get_num_default_rss_queues - default number of RSS queues
2084 2085 2086 2087
 *
 * This routine should set an upper limit on the number of RSS queues
 * used by default by multiqueue devices.
 */
2088
int netif_get_num_default_rss_queues(void)
2089 2090 2091 2092 2093
{
	return min_t(int, DEFAULT_MAX_NUM_RSS_QUEUES, num_online_cpus());
}
EXPORT_SYMBOL(netif_get_num_default_rss_queues);

2094
static inline void __netif_reschedule(struct Qdisc *q)
2095
{
2096 2097
	struct softnet_data *sd;
	unsigned long flags;
2098

2099 2100
	local_irq_save(flags);
	sd = &__get_cpu_var(softnet_data);
2101 2102 2103
	q->next_sched = NULL;
	*sd->output_queue_tailp = q;
	sd->output_queue_tailp = &q->next_sched;
2104 2105 2106 2107 2108 2109 2110 2111
	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);
2112 2113 2114
}
EXPORT_SYMBOL(__netif_schedule);

2115
void dev_kfree_skb_irq(struct sk_buff *skb)
2116
{
2117
	if (atomic_dec_and_test(&skb->users)) {
2118 2119
		struct softnet_data *sd;
		unsigned long flags;
2120

2121 2122 2123 2124 2125 2126 2127
		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);
	}
2128
}
2129
EXPORT_SYMBOL(dev_kfree_skb_irq);
2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140

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);


2141 2142 2143 2144 2145 2146
/**
 * netif_device_detach - mark device as removed
 * @dev: network device
 *
 * Mark device as removed from system and therefore no longer available.
 */
2147 2148 2149 2150
void netif_device_detach(struct net_device *dev)
{
	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
	    netif_running(dev)) {
2151
		netif_tx_stop_all_queues(dev);
2152 2153 2154 2155
	}
}
EXPORT_SYMBOL(netif_device_detach);

2156 2157 2158 2159 2160 2161
/**
 * netif_device_attach - mark device as attached
 * @dev: network device
 *
 * Mark device as attached from system and restart if needed.
 */
2162 2163 2164 2165
void netif_device_attach(struct net_device *dev)
{
	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
	    netif_running(dev)) {
2166
		netif_tx_wake_all_queues(dev);
2167
		__netdev_watchdog_up(dev);
2168 2169 2170 2171
	}
}
EXPORT_SYMBOL(netif_device_attach);

2172 2173
static void skb_warn_bad_offload(const struct sk_buff *skb)
{
2174
	static const netdev_features_t null_features = 0;
2175 2176 2177
	struct net_device *dev = skb->dev;
	const char *driver = "";

2178 2179 2180
	if (!net_ratelimit())
		return;

2181 2182 2183 2184 2185
	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",
2186 2187
	     driver, dev ? &dev->features : &null_features,
	     skb->sk ? &skb->sk->sk_route_caps : &null_features,
2188 2189 2190 2191
	     skb->len, skb->data_len, skb_shinfo(skb)->gso_size,
	     skb_shinfo(skb)->gso_type, skb->ip_summed);
}

L
Linus Torvalds 已提交
2192 2193 2194 2195
/*
 * Invalidate hardware checksum when packet is to be mangled, and
 * complete checksum manually on outgoing path.
 */
2196
int skb_checksum_help(struct sk_buff *skb)
L
Linus Torvalds 已提交
2197
{
2198
	__wsum csum;
2199
	int ret = 0, offset;
L
Linus Torvalds 已提交
2200

2201
	if (skb->ip_summed == CHECKSUM_COMPLETE)
2202 2203 2204
		goto out_set_summed;

	if (unlikely(skb_shinfo(skb)->gso_size)) {
2205 2206
		skb_warn_bad_offload(skb);
		return -EINVAL;
L
Linus Torvalds 已提交
2207 2208
	}

2209 2210 2211 2212 2213 2214 2215 2216 2217
	/* 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;
	}

2218
	offset = skb_checksum_start_offset(skb);
2219 2220 2221 2222 2223 2224 2225 2226
	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
2227 2228 2229 2230 2231
		ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
		if (ret)
			goto out;
	}

2232
	*(__sum16 *)(skb->data + offset) = csum_fold(csum);
2233
out_set_summed:
L
Linus Torvalds 已提交
2234
	skb->ip_summed = CHECKSUM_NONE;
2235
out:
L
Linus Torvalds 已提交
2236 2237
	return ret;
}
E
Eric Dumazet 已提交
2238
EXPORT_SYMBOL(skb_checksum_help);
L
Linus Torvalds 已提交
2239

2240
__be16 skb_network_protocol(struct sk_buff *skb)
2241
{
A
Al Viro 已提交
2242
	__be16 type = skb->protocol;
2243
	int vlan_depth = ETH_HLEN;
2244

2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255
	/* 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
2256
	while (type == htons(ETH_P_8021Q) || type == htons(ETH_P_8021AD)) {
2257
		struct vlan_hdr *vh;
2258

2259
		if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
2260
			return 0;
2261

2262 2263 2264
		vh = (struct vlan_hdr *)(skb->data + vlan_depth);
		type = vh->h_vlan_encapsulated_proto;
		vlan_depth += VLAN_HLEN;
2265 2266
	}

2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284
	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);

2285 2286 2287
	__skb_pull(skb, skb->mac_len);

	rcu_read_lock();
2288
	list_for_each_entry_rcu(ptype, &offload_base, list) {
2289
		if (ptype->type == type && ptype->callbacks.gso_segment) {
2290
			if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
2291 2292
				int err;

2293
				err = ptype->callbacks.gso_send_check(skb);
2294 2295 2296
				segs = ERR_PTR(err);
				if (err || skb_gso_ok(skb, features))
					break;
2297 2298
				__skb_push(skb, (skb->data -
						 skb_network_header(skb)));
2299
			}
2300
			segs = ptype->callbacks.gso_segment(skb, features);
2301 2302 2303 2304 2305
			break;
		}
	}
	rcu_read_unlock();

2306
	__skb_push(skb, skb->data - skb_mac_header(skb));
2307

2308 2309
	return segs;
}
2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346
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);
	}

2347
	SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
2348 2349 2350 2351 2352
	skb_reset_mac_header(skb);
	skb_reset_mac_len(skb);

	return skb_mac_gso_segment(skb, features);
}
2353
EXPORT_SYMBOL(__skb_gso_segment);
2354

2355 2356 2357 2358 2359
/* Take action when hardware reception checksum errors are detected. */
#ifdef CONFIG_BUG
void netdev_rx_csum_fault(struct net_device *dev)
{
	if (net_ratelimit()) {
2360
		pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
2361 2362 2363 2364 2365 2366
		dump_stack();
	}
}
EXPORT_SYMBOL(netdev_rx_csum_fault);
#endif

L
Linus Torvalds 已提交
2367 2368 2369 2370 2371
/* 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
2372
static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
L
Linus Torvalds 已提交
2373
{
2374
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2375
	int i;
2376
	if (!(dev->features & NETIF_F_HIGHDMA)) {
2377 2378 2379
		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)))
2380
				return 1;
2381
		}
2382
	}
L
Linus Torvalds 已提交
2383

2384 2385
	if (PCI_DMA_BUS_IS_PHYS) {
		struct device *pdev = dev->dev.parent;
L
Linus Torvalds 已提交
2386

E
Eric Dumazet 已提交
2387 2388
		if (!pdev)
			return 0;
2389
		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
2390 2391
			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
			dma_addr_t addr = page_to_phys(skb_frag_page(frag));
2392 2393 2394 2395
			if (!pdev->dma_mask || addr + PAGE_SIZE - 1 > *pdev->dma_mask)
				return 1;
		}
	}
2396
#endif
L
Linus Torvalds 已提交
2397 2398 2399
	return 0;
}

2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425
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
2426
 *	@features: device features as applicable to this skb
2427 2428 2429 2430
 *
 *	This function segments the given skb and stores the list of segments
 *	in skb->next.
 */
2431
static int dev_gso_segment(struct sk_buff *skb, netdev_features_t features)
2432 2433
{
	struct sk_buff *segs;
2434 2435 2436 2437 2438 2439

	segs = skb_gso_segment(skb, features);

	/* Verifying header integrity only. */
	if (!segs)
		return 0;
2440

2441
	if (IS_ERR(segs))
2442 2443 2444 2445 2446 2447 2448 2449 2450
		return PTR_ERR(segs);

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

	return 0;
}

2451 2452
static netdev_features_t harmonize_features(struct sk_buff *skb,
	__be16 protocol, netdev_features_t features)
2453
{
2454 2455
	if (skb->ip_summed != CHECKSUM_NONE &&
	    !can_checksum_protocol(features, protocol)) {
2456 2457 2458 2459 2460 2461 2462 2463
		features &= ~NETIF_F_ALL_CSUM;
	} else if (illegal_highdma(skb->dev, skb)) {
		features &= ~NETIF_F_SG;
	}

	return features;
}

2464
netdev_features_t netif_skb_features(struct sk_buff *skb)
2465 2466
{
	__be16 protocol = skb->protocol;
2467
	netdev_features_t features = skb->dev->features;
2468

2469 2470 2471
	if (skb_shinfo(skb)->gso_segs > skb->dev->gso_max_segs)
		features &= ~NETIF_F_GSO_MASK;

P
Patrick McHardy 已提交
2472
	if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD)) {
2473 2474
		struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
		protocol = veh->h_vlan_encapsulated_proto;
2475 2476 2477
	} else if (!vlan_tx_tag_present(skb)) {
		return harmonize_features(skb, protocol, features);
	}
2478

P
Patrick McHardy 已提交
2479 2480
	features &= (skb->dev->vlan_features | NETIF_F_HW_VLAN_CTAG_TX |
					       NETIF_F_HW_VLAN_STAG_TX);
2481

P
Patrick McHardy 已提交
2482
	if (protocol != htons(ETH_P_8021Q) && protocol != htons(ETH_P_8021AD)) {
2483 2484 2485
		return harmonize_features(skb, protocol, features);
	} else {
		features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
P
Patrick McHardy 已提交
2486 2487
				NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_CTAG_TX |
				NETIF_F_HW_VLAN_STAG_TX;
2488 2489
		return harmonize_features(skb, protocol, features);
	}
2490
}
2491
EXPORT_SYMBOL(netif_skb_features);
2492

2493 2494 2495
/*
 * Returns true if either:
 *	1. skb has frag_list and the device doesn't support FRAGLIST, or
2496
 *	2. skb is fragmented and the device does not support SG.
2497 2498
 */
static inline int skb_needs_linearize(struct sk_buff *skb,
2499
				      netdev_features_t features)
2500
{
2501 2502 2503
	return skb_is_nonlinear(skb) &&
			((skb_has_frag_list(skb) &&
				!(features & NETIF_F_FRAGLIST)) ||
2504
			(skb_shinfo(skb)->nr_frags &&
2505
				!(features & NETIF_F_SG)));
2506 2507
}

2508 2509
int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
			struct netdev_queue *txq)
2510
{
2511
	const struct net_device_ops *ops = dev->netdev_ops;
2512
	int rc = NETDEV_TX_OK;
2513
	unsigned int skb_len;
2514

2515
	if (likely(!skb->next)) {
2516
		netdev_features_t features;
2517

2518
		/*
L
Lucas De Marchi 已提交
2519
		 * If device doesn't need skb->dst, release it right now while
2520 2521
		 * its hot in this cpu cache
		 */
E
Eric Dumazet 已提交
2522 2523 2524
		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
			skb_dst_drop(skb);

2525 2526
		features = netif_skb_features(skb);

2527
		if (vlan_tx_tag_present(skb) &&
2528 2529 2530
		    !vlan_hw_offload_capable(features, skb->vlan_proto)) {
			skb = __vlan_put_tag(skb, skb->vlan_proto,
					     vlan_tx_tag_get(skb));
2531 2532 2533 2534 2535 2536
			if (unlikely(!skb))
				goto out;

			skb->vlan_tci = 0;
		}

2537 2538 2539 2540 2541 2542 2543
		/* 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;

2544
		if (netif_needs_gso(skb, features)) {
2545
			if (unlikely(dev_gso_segment(skb, features)))
2546 2547 2548
				goto out_kfree_skb;
			if (skb->next)
				goto gso;
2549
		} else {
2550
			if (skb_needs_linearize(skb, features) &&
2551 2552 2553 2554 2555 2556 2557 2558
			    __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) {
2559 2560 2561 2562 2563 2564
				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));
2565
				if (!(features & NETIF_F_ALL_CSUM) &&
2566 2567 2568
				     skb_checksum_help(skb))
					goto out_kfree_skb;
			}
2569 2570
		}

2571 2572 2573
		if (!list_empty(&ptype_all))
			dev_queue_xmit_nit(skb, dev);

2574
		skb_len = skb->len;
2575
		rc = ops->ndo_start_xmit(skb, dev);
2576
		trace_net_dev_xmit(skb, rc, dev, skb_len);
2577
		if (rc == NETDEV_TX_OK)
E
Eric Dumazet 已提交
2578
			txq_trans_update(txq);
2579
		return rc;
2580 2581
	}

2582
gso:
2583 2584 2585 2586 2587
	do {
		struct sk_buff *nskb = skb->next;

		skb->next = nskb->next;
		nskb->next = NULL;
2588

2589 2590 2591
		if (!list_empty(&ptype_all))
			dev_queue_xmit_nit(nskb, dev);

2592
		skb_len = nskb->len;
2593
		rc = ops->ndo_start_xmit(nskb, dev);
2594
		trace_net_dev_xmit(nskb, rc, dev, skb_len);
2595
		if (unlikely(rc != NETDEV_TX_OK)) {
2596 2597
			if (rc & ~NETDEV_TX_MASK)
				goto out_kfree_gso_skb;
2598
			nskb->next = skb->next;
2599 2600 2601
			skb->next = nskb;
			return rc;
		}
E
Eric Dumazet 已提交
2602
		txq_trans_update(txq);
2603
		if (unlikely(netif_xmit_stopped(txq) && skb->next))
2604
			return NETDEV_TX_BUSY;
2605
	} while (skb->next);
2606

2607
out_kfree_gso_skb:
2608
	if (likely(skb->next == NULL)) {
2609
		skb->destructor = DEV_GSO_CB(skb)->destructor;
2610 2611 2612
		consume_skb(skb);
		return rc;
	}
2613 2614
out_kfree_skb:
	kfree_skb(skb);
2615
out:
2616
	return rc;
2617 2618
}

2619 2620 2621 2622 2623 2624 2625 2626 2627 2628
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)  {
2629
		unsigned int hdr_len;
2630
		u16 gso_segs = shinfo->gso_segs;
2631

2632 2633 2634 2635
		/* mac layer + network layer */
		hdr_len = skb_transport_header(skb) - skb_mac_header(skb);

		/* + transport layer */
2636 2637 2638 2639
		if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
			hdr_len += tcp_hdrlen(skb);
		else
			hdr_len += sizeof(struct udphdr);
2640 2641 2642 2643 2644 2645

		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;
2646 2647 2648
	}
}

2649 2650 2651 2652 2653
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
2654
	bool contended;
2655 2656
	int rc;

2657
	qdisc_pkt_len_init(skb);
E
Eric Dumazet 已提交
2658
	qdisc_calculate_pkt_len(skb, q);
2659 2660 2661 2662 2663 2664
	/*
	 * 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
2665
	contended = qdisc_is_running(q);
2666 2667 2668
	if (unlikely(contended))
		spin_lock(&q->busylock);

2669 2670 2671 2672 2673
	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) &&
2674
		   qdisc_run_begin(q)) {
2675 2676 2677 2678 2679
		/*
		 * 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
2680 2681
		if (!(dev->priv_flags & IFF_XMIT_DST_RELEASE))
			skb_dst_force(skb);
2682 2683 2684

		qdisc_bstats_update(q, skb);

2685 2686 2687 2688 2689
		if (sch_direct_xmit(skb, q, dev, txq, root_lock)) {
			if (unlikely(contended)) {
				spin_unlock(&q->busylock);
				contended = false;
			}
2690
			__qdisc_run(q);
2691
		} else
2692
			qdisc_run_end(q);
2693 2694 2695

		rc = NET_XMIT_SUCCESS;
	} else {
E
Eric Dumazet 已提交
2696
		skb_dst_force(skb);
E
Eric Dumazet 已提交
2697
		rc = q->enqueue(skb, q) & NET_XMIT_MASK;
2698 2699 2700 2701 2702 2703 2704
		if (qdisc_run_begin(q)) {
			if (unlikely(contended)) {
				spin_unlock(&q->busylock);
				contended = false;
			}
			__qdisc_run(q);
		}
2705 2706
	}
	spin_unlock(root_lock);
2707 2708
	if (unlikely(contended))
		spin_unlock(&q->busylock);
2709 2710 2711
	return rc;
}

2712 2713 2714
#if IS_ENABLED(CONFIG_NETPRIO_CGROUP)
static void skb_update_prio(struct sk_buff *skb)
{
I
Igor Maravic 已提交
2715
	struct netprio_map *map = rcu_dereference_bh(skb->dev->priomap);
2716

2717 2718 2719 2720 2721 2722
	if (!skb->priority && skb->sk && map) {
		unsigned int prioidx = skb->sk->sk_cgrp_prioidx;

		if (prioidx < map->priomap_len)
			skb->priority = map->priomap[prioidx];
	}
2723 2724 2725 2726 2727
}
#else
#define skb_update_prio(skb)
#endif

2728
static DEFINE_PER_CPU(int, xmit_recursion);
2729
#define RECURSION_LIMIT 10
2730

2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747
/**
 *	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);

2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772
/**
 *	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
2773 2774 2775
int dev_queue_xmit(struct sk_buff *skb)
{
	struct net_device *dev = skb->dev;
2776
	struct netdev_queue *txq;
L
Linus Torvalds 已提交
2777 2778 2779
	struct Qdisc *q;
	int rc = -ENOMEM;

2780 2781
	skb_reset_mac_header(skb);

2782 2783
	/* Disable soft irqs for various locks below. Also
	 * stops preemption for RCU.
L
Linus Torvalds 已提交
2784
	 */
2785
	rcu_read_lock_bh();
L
Linus Torvalds 已提交
2786

2787 2788
	skb_update_prio(skb);

2789
	txq = netdev_pick_tx(dev, skb);
2790
	q = rcu_dereference_bh(txq->qdisc);
2791

L
Linus Torvalds 已提交
2792
#ifdef CONFIG_NET_CLS_ACT
E
Eric Dumazet 已提交
2793
	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_EGRESS);
L
Linus Torvalds 已提交
2794
#endif
2795
	trace_net_dev_queue(skb);
L
Linus Torvalds 已提交
2796
	if (q->enqueue) {
2797
		rc = __dev_xmit_skb(skb, q, dev, txq);
2798
		goto out;
L
Linus Torvalds 已提交
2799 2800 2801 2802 2803
	}

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

H
Herbert Xu 已提交
2804 2805
	   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
2806 2807 2808 2809 2810 2811 2812 2813 2814 2815
	   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 */

2816
		if (txq->xmit_lock_owner != cpu) {
L
Linus Torvalds 已提交
2817

2818 2819 2820
			if (__this_cpu_read(xmit_recursion) > RECURSION_LIMIT)
				goto recursion_alert;

2821
			HARD_TX_LOCK(dev, txq, cpu);
L
Linus Torvalds 已提交
2822

2823
			if (!netif_xmit_stopped(txq)) {
2824
				__this_cpu_inc(xmit_recursion);
2825
				rc = dev_hard_start_xmit(skb, dev, txq);
2826
				__this_cpu_dec(xmit_recursion);
2827
				if (dev_xmit_complete(rc)) {
2828
					HARD_TX_UNLOCK(dev, txq);
L
Linus Torvalds 已提交
2829 2830 2831
					goto out;
				}
			}
2832
			HARD_TX_UNLOCK(dev, txq);
2833 2834
			net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
					     dev->name);
L
Linus Torvalds 已提交
2835 2836
		} else {
			/* Recursion is detected! It is possible,
2837 2838 2839
			 * unfortunately
			 */
recursion_alert:
2840 2841
			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
					     dev->name);
L
Linus Torvalds 已提交
2842 2843 2844 2845
		}
	}

	rc = -ENETDOWN;
2846
	rcu_read_unlock_bh();
L
Linus Torvalds 已提交
2847 2848 2849 2850

	kfree_skb(skb);
	return rc;
out:
2851
	rcu_read_unlock_bh();
L
Linus Torvalds 已提交
2852 2853
	return rc;
}
E
Eric Dumazet 已提交
2854
EXPORT_SYMBOL(dev_queue_xmit);
L
Linus Torvalds 已提交
2855 2856 2857 2858 2859 2860


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

2861
int netdev_max_backlog __read_mostly = 1000;
E
Eric Dumazet 已提交
2862 2863
EXPORT_SYMBOL(netdev_max_backlog);

E
Eric Dumazet 已提交
2864
int netdev_tstamp_prequeue __read_mostly = 1;
2865 2866
int netdev_budget __read_mostly = 300;
int weight_p __read_mostly = 64;            /* old backlog weight */
L
Linus Torvalds 已提交
2867

E
Eric Dumazet 已提交
2868 2869 2870 2871 2872 2873 2874 2875
/* 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);
}

2876 2877 2878
#ifdef CONFIG_RPS

/* One global table that all flow-based protocols share. */
E
Eric Dumazet 已提交
2879
struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
2880 2881
EXPORT_SYMBOL(rps_sock_flow_table);

2882
struct static_key rps_needed __read_mostly;
2883

2884 2885 2886 2887
static struct rps_dev_flow *
set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
	    struct rps_dev_flow *rflow, u16 next_cpu)
{
2888
	if (next_cpu != RPS_NO_CPU) {
2889 2890 2891 2892 2893 2894 2895 2896 2897
#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? */
2898 2899
		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
		    !(dev->features & NETIF_F_NTUPLE))
2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921
			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 =
2922
			per_cpu(softnet_data, next_cpu).input_queue_head;
2923 2924
	}

2925
	rflow->cpu = next_cpu;
2926 2927 2928
	return rflow;
}

2929 2930 2931 2932 2933 2934 2935 2936 2937
/*
 * 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
2938
	struct rps_map *map;
2939 2940 2941 2942 2943 2944 2945
	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);
2946 2947 2948 2949 2950
		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);
2951 2952 2953 2954 2955 2956
			goto done;
		}
		rxqueue = dev->_rx + index;
	} else
		rxqueue = dev->_rx;

E
Eric Dumazet 已提交
2957 2958
	map = rcu_dereference(rxqueue->rps_map);
	if (map) {
2959
		if (map->len == 1 &&
2960
		    !rcu_access_pointer(rxqueue->rps_flow_table)) {
2961 2962 2963 2964 2965
			tcpu = map->cpus[0];
			if (cpu_online(tcpu))
				cpu = tcpu;
			goto done;
		}
2966
	} else if (!rcu_access_pointer(rxqueue->rps_flow_table)) {
2967
		goto done;
2968
	}
2969

2970
	skb_reset_network_header(skb);
2971 2972 2973
	if (!skb_get_rxhash(skb))
		goto done;

T
Tom Herbert 已提交
2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999
	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 -
3000 3001
		      rflow->last_qtail)) >= 0)) {
			tcpu = next_cpu;
3002
			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
3003
		}
3004

T
Tom Herbert 已提交
3005 3006 3007 3008 3009 3010 3011
		if (tcpu != RPS_NO_CPU && cpu_online(tcpu)) {
			*rflowp = rflow;
			cpu = tcpu;
			goto done;
		}
	}

T
Tom Herbert 已提交
3012
	if (map) {
T
Tom Herbert 已提交
3013
		tcpu = map->cpus[((u64) skb->rxhash * map->len) >> 32];
T
Tom Herbert 已提交
3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024

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

done:
	return cpu;
}

3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064
#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
3065
/* Called from hardirq (IPI) context */
E
Eric Dumazet 已提交
3066
static void rps_trigger_softirq(void *data)
T
Tom Herbert 已提交
3067
{
E
Eric Dumazet 已提交
3068 3069
	struct softnet_data *sd = data;

E
Eric Dumazet 已提交
3070
	____napi_schedule(sd, &sd->backlog);
C
Changli Gao 已提交
3071
	sd->received_rps++;
T
Tom Herbert 已提交
3072
}
E
Eric Dumazet 已提交
3073

T
Tom Herbert 已提交
3074
#endif /* CONFIG_RPS */
T
Tom Herbert 已提交
3075

E
Eric Dumazet 已提交
3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096
/*
 * 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;
}

3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136
#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
3137 3138 3139 3140
/*
 * 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
3141 3142
static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
			      unsigned int *qtail)
T
Tom Herbert 已提交
3143
{
E
Eric Dumazet 已提交
3144
	struct softnet_data *sd;
T
Tom Herbert 已提交
3145
	unsigned long flags;
3146
	unsigned int qlen;
T
Tom Herbert 已提交
3147

E
Eric Dumazet 已提交
3148
	sd = &per_cpu(softnet_data, cpu);
T
Tom Herbert 已提交
3149 3150 3151

	local_irq_save(flags);

E
Eric Dumazet 已提交
3152
	rps_lock(sd);
3153 3154
	qlen = skb_queue_len(&sd->input_pkt_queue);
	if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) {
3155
		if (skb_queue_len(&sd->input_pkt_queue)) {
T
Tom Herbert 已提交
3156
enqueue:
E
Eric Dumazet 已提交
3157
			__skb_queue_tail(&sd->input_pkt_queue, skb);
3158
			input_queue_tail_incr_save(sd, qtail);
E
Eric Dumazet 已提交
3159
			rps_unlock(sd);
3160
			local_irq_restore(flags);
T
Tom Herbert 已提交
3161 3162 3163
			return NET_RX_SUCCESS;
		}

3164 3165 3166 3167
		/* 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
3168
			if (!rps_ipi_queued(sd))
E
Eric Dumazet 已提交
3169
				____napi_schedule(sd, &sd->backlog);
T
Tom Herbert 已提交
3170 3171 3172 3173
		}
		goto enqueue;
	}

C
Changli Gao 已提交
3174
	sd->dropped++;
E
Eric Dumazet 已提交
3175
	rps_unlock(sd);
T
Tom Herbert 已提交
3176 3177 3178

	local_irq_restore(flags);

3179
	atomic_long_inc(&skb->dev->rx_dropped);
T
Tom Herbert 已提交
3180 3181 3182
	kfree_skb(skb);
	return NET_RX_DROP;
}
L
Linus Torvalds 已提交
3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200

/**
 *	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)
{
3201
	int ret;
L
Linus Torvalds 已提交
3202 3203 3204 3205 3206

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

3207
	net_timestamp_check(netdev_tstamp_prequeue, skb);
L
Linus Torvalds 已提交
3208

3209
	trace_netif_rx(skb);
E
Eric Dumazet 已提交
3210
#ifdef CONFIG_RPS
3211
	if (static_key_false(&rps_needed)) {
T
Tom Herbert 已提交
3212
		struct rps_dev_flow voidflow, *rflow = &voidflow;
3213 3214
		int cpu;

3215
		preempt_disable();
3216
		rcu_read_lock();
T
Tom Herbert 已提交
3217 3218

		cpu = get_rps_cpu(skb->dev, skb, &rflow);
3219 3220
		if (cpu < 0)
			cpu = smp_processor_id();
T
Tom Herbert 已提交
3221 3222 3223

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

3224
		rcu_read_unlock();
3225
		preempt_enable();
3226 3227
	} else
#endif
T
Tom Herbert 已提交
3228 3229 3230 3231 3232
	{
		unsigned int qtail;
		ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
		put_cpu();
	}
3233
	return ret;
L
Linus Torvalds 已提交
3234
}
E
Eric Dumazet 已提交
3235
EXPORT_SYMBOL(netif_rx);
L
Linus Torvalds 已提交
3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266

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;

3267
			WARN_ON(atomic_read(&skb->users));
3268
			trace_kfree_skb(skb, net_tx_action);
L
Linus Torvalds 已提交
3269 3270 3271 3272 3273
			__kfree_skb(skb);
		}
	}

	if (sd->output_queue) {
3274
		struct Qdisc *head;
L
Linus Torvalds 已提交
3275 3276 3277 3278

		local_irq_disable();
		head = sd->output_queue;
		sd->output_queue = NULL;
3279
		sd->output_queue_tailp = &sd->output_queue;
L
Linus Torvalds 已提交
3280 3281 3282
		local_irq_enable();

		while (head) {
3283 3284 3285
			struct Qdisc *q = head;
			spinlock_t *root_lock;

L
Linus Torvalds 已提交
3286 3287
			head = head->next_sched;

3288
			root_lock = qdisc_lock(q);
3289
			if (spin_trylock(root_lock)) {
3290 3291 3292
				smp_mb__before_clear_bit();
				clear_bit(__QDISC_STATE_SCHED,
					  &q->state);
3293 3294
				qdisc_run(q);
				spin_unlock(root_lock);
L
Linus Torvalds 已提交
3295
			} else {
3296
				if (!test_bit(__QDISC_STATE_DEACTIVATED,
3297
					      &q->state)) {
3298
					__netif_reschedule(q);
3299 3300 3301 3302 3303
				} else {
					smp_mb__before_clear_bit();
					clear_bit(__QDISC_STATE_SCHED,
						  &q->state);
				}
L
Linus Torvalds 已提交
3304 3305 3306 3307 3308
			}
		}
	}
}

3309 3310
#if (defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)) && \
    (defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE))
3311 3312 3313
/* This hook is defined here for ATM LANE */
int (*br_fdb_test_addr_hook)(struct net_device *dev,
			     unsigned char *addr) __read_mostly;
3314
EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
3315
#endif
L
Linus Torvalds 已提交
3316 3317 3318 3319 3320 3321

#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
3322 3323
 * 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
3324 3325
 *
 */
3326
static int ing_filter(struct sk_buff *skb, struct netdev_queue *rxq)
L
Linus Torvalds 已提交
3327 3328
{
	struct net_device *dev = skb->dev;
3329
	u32 ttl = G_TC_RTTL(skb->tc_verd);
3330 3331
	int result = TC_ACT_OK;
	struct Qdisc *q;
3332

3333
	if (unlikely(MAX_RED_LOOP < ttl++)) {
3334 3335
		net_warn_ratelimited("Redir loop detected Dropping packet (%d->%d)\n",
				     skb->skb_iif, dev->ifindex);
3336 3337
		return TC_ACT_SHOT;
	}
L
Linus Torvalds 已提交
3338

3339 3340
	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
3341

3342
	q = rxq->qdisc;
3343
	if (q != &noop_qdisc) {
3344
		spin_lock(qdisc_lock(q));
3345 3346
		if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))
			result = qdisc_enqueue_root(skb, q);
3347 3348
		spin_unlock(qdisc_lock(q));
	}
3349 3350 3351

	return result;
}
3352

3353 3354 3355 3356
static inline struct sk_buff *handle_ing(struct sk_buff *skb,
					 struct packet_type **pt_prev,
					 int *ret, struct net_device *orig_dev)
{
3357 3358 3359
	struct netdev_queue *rxq = rcu_dereference(skb->dev->ingress_queue);

	if (!rxq || rxq->qdisc == &noop_qdisc)
3360
		goto out;
L
Linus Torvalds 已提交
3361

3362 3363 3364
	if (*pt_prev) {
		*ret = deliver_skb(skb, *pt_prev, orig_dev);
		*pt_prev = NULL;
L
Linus Torvalds 已提交
3365 3366
	}

3367
	switch (ing_filter(skb, rxq)) {
3368 3369 3370 3371 3372 3373 3374 3375 3376
	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
3377 3378 3379
}
#endif

3380 3381 3382 3383
/**
 *	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
3384
 *	@rx_handler_data: data pointer that is used by rx handler
3385 3386 3387 3388 3389 3390
 *
 *	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.
3391 3392
 *
 *	For a general description of rx_handler, see enum rx_handler_result.
3393 3394
 */
int netdev_rx_handler_register(struct net_device *dev,
J
Jiri Pirko 已提交
3395 3396
			       rx_handler_func_t *rx_handler,
			       void *rx_handler_data)
3397 3398 3399 3400 3401 3402
{
	ASSERT_RTNL();

	if (dev->rx_handler)
		return -EBUSY;

3403
	/* Note: rx_handler_data must be set before rx_handler */
J
Jiri Pirko 已提交
3404
	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
3405 3406 3407 3408 3409 3410 3411 3412 3413 3414
	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
3415
 *	Unregister a receive handler from a device.
3416 3417 3418 3419 3420 3421 3422
 *
 *	The caller must hold the rtnl_mutex.
 */
void netdev_rx_handler_unregister(struct net_device *dev)
{

	ASSERT_RTNL();
3423
	RCU_INIT_POINTER(dev->rx_handler, NULL);
3424 3425 3426 3427 3428
	/* 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();
3429
	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
3430 3431 3432
}
EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);

3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443
/*
 * 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
3444
	case __constant_htons(ETH_P_8021AD):
3445 3446 3447 3448 3449 3450
		return true;
	default:
		return false;
	}
}

3451
static int __netif_receive_skb_core(struct sk_buff *skb, bool pfmemalloc)
L
Linus Torvalds 已提交
3452 3453
{
	struct packet_type *ptype, *pt_prev;
3454
	rx_handler_func_t *rx_handler;
D
David S. Miller 已提交
3455
	struct net_device *orig_dev;
3456
	struct net_device *null_or_dev;
3457
	bool deliver_exact = false;
L
Linus Torvalds 已提交
3458
	int ret = NET_RX_DROP;
A
Al Viro 已提交
3459
	__be16 type;
L
Linus Torvalds 已提交
3460

3461
	net_timestamp_check(!netdev_tstamp_prequeue, skb);
3462

3463
	trace_netif_receive_skb(skb);
3464

L
Linus Torvalds 已提交
3465
	/* if we've gotten here through NAPI, check netpoll */
3466
	if (netpoll_receive_skb(skb))
3467
		goto out;
L
Linus Torvalds 已提交
3468

J
Joe Eykholt 已提交
3469
	orig_dev = skb->dev;
3470

3471
	skb_reset_network_header(skb);
3472 3473
	if (!skb_transport_header_was_set(skb))
		skb_reset_transport_header(skb);
3474
	skb_reset_mac_len(skb);
L
Linus Torvalds 已提交
3475 3476 3477 3478 3479

	pt_prev = NULL;

	rcu_read_lock();

3480
another_round:
3481
	skb->skb_iif = skb->dev->ifindex;
3482 3483 3484

	__this_cpu_inc(softnet_data.processed);

P
Patrick McHardy 已提交
3485 3486
	if (skb->protocol == cpu_to_be16(ETH_P_8021Q) ||
	    skb->protocol == cpu_to_be16(ETH_P_8021AD)) {
3487 3488
		skb = vlan_untag(skb);
		if (unlikely(!skb))
3489
			goto unlock;
3490 3491
	}

L
Linus Torvalds 已提交
3492 3493 3494 3495 3496 3497 3498
#ifdef CONFIG_NET_CLS_ACT
	if (skb->tc_verd & TC_NCLS) {
		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
		goto ncls;
	}
#endif

3499
	if (pfmemalloc)
3500 3501
		goto skip_taps;

L
Linus Torvalds 已提交
3502
	list_for_each_entry_rcu(ptype, &ptype_all, list) {
3503
		if (!ptype->dev || ptype->dev == skb->dev) {
3504
			if (pt_prev)
D
David S. Miller 已提交
3505
				ret = deliver_skb(skb, pt_prev, orig_dev);
L
Linus Torvalds 已提交
3506 3507 3508 3509
			pt_prev = ptype;
		}
	}

3510
skip_taps:
L
Linus Torvalds 已提交
3511
#ifdef CONFIG_NET_CLS_ACT
3512 3513
	skb = handle_ing(skb, &pt_prev, &ret, orig_dev);
	if (!skb)
3514
		goto unlock;
L
Linus Torvalds 已提交
3515 3516 3517
ncls:
#endif

3518
	if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
3519 3520
		goto drop;

3521 3522 3523 3524 3525
	if (vlan_tx_tag_present(skb)) {
		if (pt_prev) {
			ret = deliver_skb(skb, pt_prev, orig_dev);
			pt_prev = NULL;
		}
3526
		if (vlan_do_receive(&skb))
3527 3528
			goto another_round;
		else if (unlikely(!skb))
3529
			goto unlock;
3530 3531
	}

3532
	rx_handler = rcu_dereference(skb->dev->rx_handler);
3533 3534 3535 3536 3537
	if (rx_handler) {
		if (pt_prev) {
			ret = deliver_skb(skb, pt_prev, orig_dev);
			pt_prev = NULL;
		}
3538 3539
		switch (rx_handler(&skb)) {
		case RX_HANDLER_CONSUMED:
3540
			ret = NET_RX_SUCCESS;
3541
			goto unlock;
3542
		case RX_HANDLER_ANOTHER:
3543
			goto another_round;
3544 3545 3546 3547 3548 3549 3550
		case RX_HANDLER_EXACT:
			deliver_exact = true;
		case RX_HANDLER_PASS:
			break;
		default:
			BUG();
		}
3551
	}
L
Linus Torvalds 已提交
3552

3553 3554 3555
	if (vlan_tx_nonzero_tag_present(skb))
		skb->pkt_type = PACKET_OTHERHOST;

3556
	/* deliver only exact match when indicated */
3557
	null_or_dev = deliver_exact ? skb->dev : NULL;
3558

L
Linus Torvalds 已提交
3559
	type = skb->protocol;
3560 3561
	list_for_each_entry_rcu(ptype,
			&ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
3562
		if (ptype->type == type &&
3563 3564
		    (ptype->dev == null_or_dev || ptype->dev == skb->dev ||
		     ptype->dev == orig_dev)) {
3565
			if (pt_prev)
D
David S. Miller 已提交
3566
				ret = deliver_skb(skb, pt_prev, orig_dev);
L
Linus Torvalds 已提交
3567 3568 3569 3570 3571
			pt_prev = ptype;
		}
	}

	if (pt_prev) {
3572
		if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
3573
			goto drop;
3574 3575
		else
			ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
L
Linus Torvalds 已提交
3576
	} else {
3577
drop:
3578
		atomic_long_inc(&skb->dev->rx_dropped);
L
Linus Torvalds 已提交
3579 3580 3581 3582 3583 3584 3585
		kfree_skb(skb);
		/* Jamal, now you will not able to escape explaining
		 * me how you were going to use this. :-)
		 */
		ret = NET_RX_DROP;
	}

3586
unlock:
L
Linus Torvalds 已提交
3587
	rcu_read_unlock();
3588
out:
3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613
	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
3614 3615
	return ret;
}
T
Tom Herbert 已提交
3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633

/**
 *	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)
{
3634
	net_timestamp_check(netdev_tstamp_prequeue, skb);
E
Eric Dumazet 已提交
3635

3636 3637 3638
	if (skb_defer_rx_timestamp(skb))
		return NET_RX_SUCCESS;

E
Eric Dumazet 已提交
3639
#ifdef CONFIG_RPS
3640
	if (static_key_false(&rps_needed)) {
E
Eric Dumazet 已提交
3641 3642
		struct rps_dev_flow voidflow, *rflow = &voidflow;
		int cpu, ret;
T
Tom Herbert 已提交
3643

E
Eric Dumazet 已提交
3644 3645 3646
		rcu_read_lock();

		cpu = get_rps_cpu(skb->dev, skb, &rflow);
T
Tom Herbert 已提交
3647

E
Eric Dumazet 已提交
3648 3649 3650
		if (cpu >= 0) {
			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
			rcu_read_unlock();
3651
			return ret;
E
Eric Dumazet 已提交
3652
		}
3653
		rcu_read_unlock();
T
Tom Herbert 已提交
3654
	}
3655
#endif
3656
	return __netif_receive_skb(skb);
T
Tom Herbert 已提交
3657
}
E
Eric Dumazet 已提交
3658
EXPORT_SYMBOL(netif_receive_skb);
L
Linus Torvalds 已提交
3659

E
Eric Dumazet 已提交
3660 3661 3662
/* Network device is going away, flush any packets still pending
 * Called with irqs disabled.
 */
3663
static void flush_backlog(void *arg)
3664
{
3665
	struct net_device *dev = arg;
E
Eric Dumazet 已提交
3666
	struct softnet_data *sd = &__get_cpu_var(softnet_data);
3667 3668
	struct sk_buff *skb, *tmp;

E
Eric Dumazet 已提交
3669
	rps_lock(sd);
3670
	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
3671
		if (skb->dev == dev) {
E
Eric Dumazet 已提交
3672
			__skb_unlink(skb, &sd->input_pkt_queue);
3673
			kfree_skb(skb);
3674
			input_queue_head_incr(sd);
3675
		}
3676
	}
E
Eric Dumazet 已提交
3677
	rps_unlock(sd);
3678 3679 3680 3681 3682

	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
		if (skb->dev == dev) {
			__skb_unlink(skb, &sd->process_queue);
			kfree_skb(skb);
3683
			input_queue_head_incr(sd);
3684 3685
		}
	}
3686 3687
}

3688 3689
static int napi_gro_complete(struct sk_buff *skb)
{
3690
	struct packet_offload *ptype;
3691
	__be16 type = skb->protocol;
3692
	struct list_head *head = &offload_base;
3693 3694
	int err = -ENOENT;

3695 3696
	BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));

3697 3698
	if (NAPI_GRO_CB(skb)->count == 1) {
		skb_shinfo(skb)->gso_size = 0;
3699
		goto out;
3700
	}
3701 3702 3703

	rcu_read_lock();
	list_for_each_entry_rcu(ptype, head, list) {
3704
		if (ptype->type != type || !ptype->callbacks.gro_complete)
3705 3706
			continue;

3707
		err = ptype->callbacks.gro_complete(skb);
3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721
		break;
	}
	rcu_read_unlock();

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

out:
	return netif_receive_skb(skb);
}

3722 3723 3724 3725 3726
/* 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)
3727
{
3728
	struct sk_buff *skb, *prev = NULL;
3729

3730 3731 3732 3733 3734 3735 3736
	/* 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) {
3737
		skb->next = NULL;
3738 3739 3740 3741 3742

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

		prev = skb->prev;
3743
		napi_gro_complete(skb);
3744
		napi->gro_count--;
3745 3746 3747 3748
	}

	napi->gro_list = NULL;
}
E
Eric Dumazet 已提交
3749
EXPORT_SYMBOL(napi_gro_flush);
3750

E
Eric Dumazet 已提交
3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772
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
3773
static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3774 3775
{
	struct sk_buff **pp = NULL;
3776
	struct packet_offload *ptype;
3777
	__be16 type = skb->protocol;
3778
	struct list_head *head = &offload_base;
H
Herbert Xu 已提交
3779
	int same_flow;
3780
	enum gro_result ret;
3781

3782
	if (!(skb->dev->features & NETIF_F_GRO) || netpoll_rx_on(skb))
3783 3784
		goto normal;

3785
	if (skb_is_gso(skb) || skb_has_frag_list(skb))
3786 3787
		goto normal;

E
Eric Dumazet 已提交
3788 3789
	gro_list_prepare(napi, skb);

3790 3791
	rcu_read_lock();
	list_for_each_entry_rcu(ptype, head, list) {
3792
		if (ptype->type != type || !ptype->callbacks.gro_receive)
3793 3794
			continue;

3795
		skb_set_network_header(skb, skb_gro_offset(skb));
3796
		skb_reset_mac_len(skb);
3797 3798
		NAPI_GRO_CB(skb)->same_flow = 0;
		NAPI_GRO_CB(skb)->flush = 0;
H
Herbert Xu 已提交
3799
		NAPI_GRO_CB(skb)->free = 0;
3800

3801
		pp = ptype->callbacks.gro_receive(&napi->gro_list, skb);
3802 3803 3804 3805 3806 3807 3808
		break;
	}
	rcu_read_unlock();

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

H
Herbert Xu 已提交
3809
	same_flow = NAPI_GRO_CB(skb)->same_flow;
3810
	ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
H
Herbert Xu 已提交
3811

3812 3813 3814 3815 3816 3817
	if (pp) {
		struct sk_buff *nskb = *pp;

		*pp = nskb->next;
		nskb->next = NULL;
		napi_gro_complete(nskb);
3818
		napi->gro_count--;
3819 3820
	}

H
Herbert Xu 已提交
3821
	if (same_flow)
3822 3823
		goto ok;

3824
	if (NAPI_GRO_CB(skb)->flush || napi->gro_count >= MAX_GRO_SKBS)
3825 3826
		goto normal;

3827
	napi->gro_count++;
3828
	NAPI_GRO_CB(skb)->count = 1;
3829
	NAPI_GRO_CB(skb)->age = jiffies;
3830
	skb_shinfo(skb)->gso_size = skb_gro_len(skb);
3831 3832
	skb->next = napi->gro_list;
	napi->gro_list = skb;
3833
	ret = GRO_HELD;
3834

3835
pull:
H
Herbert Xu 已提交
3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846
	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
3847
		skb_frag_size_sub(&skb_shinfo(skb)->frags[0], grow);
H
Herbert Xu 已提交
3848

E
Eric Dumazet 已提交
3849
		if (unlikely(!skb_frag_size(&skb_shinfo(skb)->frags[0]))) {
3850
			skb_frag_unref(skb, 0);
H
Herbert Xu 已提交
3851 3852
			memmove(skb_shinfo(skb)->frags,
				skb_shinfo(skb)->frags + 1,
3853
				--skb_shinfo(skb)->nr_frags * sizeof(skb_frag_t));
H
Herbert Xu 已提交
3854
		}
3855 3856
	}

3857
ok:
3858
	return ret;
3859 3860

normal:
3861 3862
	ret = GRO_NORMAL;
	goto pull;
H
Herbert Xu 已提交
3863
}
3864

H
Herbert Xu 已提交
3865

R
Rami Rosen 已提交
3866
static gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
H
Herbert Xu 已提交
3867
{
3868 3869
	switch (ret) {
	case GRO_NORMAL:
3870 3871 3872
		if (netif_receive_skb(skb))
			ret = GRO_DROP;
		break;
H
Herbert Xu 已提交
3873

3874
	case GRO_DROP:
H
Herbert Xu 已提交
3875 3876
		kfree_skb(skb);
		break;
3877

3878
	case GRO_MERGED_FREE:
3879 3880 3881 3882
		if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
			kmem_cache_free(skbuff_head_cache, skb);
		else
			__kfree_skb(skb);
3883 3884
		break;

3885 3886 3887
	case GRO_HELD:
	case GRO_MERGED:
		break;
H
Herbert Xu 已提交
3888 3889
	}

3890
	return ret;
3891 3892
}

3893
static void skb_gro_reset_offset(struct sk_buff *skb)
3894
{
3895 3896 3897
	const struct skb_shared_info *pinfo = skb_shinfo(skb);
	const skb_frag_t *frag0 = &pinfo->frags[0];

3898 3899
	NAPI_GRO_CB(skb)->data_offset = 0;
	NAPI_GRO_CB(skb)->frag0 = NULL;
3900
	NAPI_GRO_CB(skb)->frag0_len = 0;
3901

3902
	if (skb_mac_header(skb) == skb_tail_pointer(skb) &&
3903 3904 3905 3906
	    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);
3907
	}
3908 3909
}

3910
gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3911
{
3912 3913
	skb_gro_reset_offset(skb);

E
Eric Dumazet 已提交
3914
	return napi_skb_finish(dev_gro_receive(napi, skb), skb);
3915 3916 3917
}
EXPORT_SYMBOL(napi_gro_receive);

S
stephen hemminger 已提交
3918
static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
3919 3920
{
	__skb_pull(skb, skb_headlen(skb));
3921 3922
	/* restore the reserve we had after netdev_alloc_skb_ip_align() */
	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
3923
	skb->vlan_tci = 0;
H
Herbert Xu 已提交
3924
	skb->dev = napi->dev;
A
Andy Gospodarek 已提交
3925
	skb->skb_iif = 0;
3926 3927 3928 3929

	napi->skb = skb;
}

3930
struct sk_buff *napi_get_frags(struct napi_struct *napi)
H
Herbert Xu 已提交
3931 3932 3933 3934
{
	struct sk_buff *skb = napi->skb;

	if (!skb) {
3935 3936 3937
		skb = netdev_alloc_skb_ip_align(napi->dev, GRO_MAX_HEAD);
		if (skb)
			napi->skb = skb;
3938
	}
3939 3940
	return skb;
}
3941
EXPORT_SYMBOL(napi_get_frags);
3942

R
Rami Rosen 已提交
3943
static gro_result_t napi_frags_finish(struct napi_struct *napi, struct sk_buff *skb,
3944
			       gro_result_t ret)
3945
{
3946 3947
	switch (ret) {
	case GRO_NORMAL:
3948
	case GRO_HELD:
3949
		skb->protocol = eth_type_trans(skb, skb->dev);
3950

3951 3952 3953 3954
		if (ret == GRO_HELD)
			skb_gro_pull(skb, -ETH_HLEN);
		else if (netif_receive_skb(skb))
			ret = GRO_DROP;
3955
		break;
H
Herbert Xu 已提交
3956

3957 3958 3959 3960
	case GRO_DROP:
	case GRO_MERGED_FREE:
		napi_reuse_skb(napi, skb);
		break;
3961 3962 3963

	case GRO_MERGED:
		break;
3964
	}
H
Herbert Xu 已提交
3965

3966
	return ret;
H
Herbert Xu 已提交
3967
}
3968

E
Eric Dumazet 已提交
3969
static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
3970 3971 3972
{
	struct sk_buff *skb = napi->skb;
	struct ethhdr *eth;
3973 3974
	unsigned int hlen;
	unsigned int off;
3975 3976 3977 3978 3979 3980

	napi->skb = NULL;

	skb_reset_mac_header(skb);
	skb_gro_reset_offset(skb);

3981 3982 3983 3984 3985 3986 3987 3988 3989 3990
	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;
		}
3991 3992 3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004
	}

	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;
}

4005
gro_result_t napi_gro_frags(struct napi_struct *napi)
4006
{
4007
	struct sk_buff *skb = napi_frags_skb(napi);
4008 4009

	if (!skb)
4010
		return GRO_DROP;
4011

E
Eric Dumazet 已提交
4012
	return napi_frags_finish(napi, skb, dev_gro_receive(napi, skb));
4013
}
H
Herbert Xu 已提交
4014 4015
EXPORT_SYMBOL(napi_gro_frags);

4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043
/*
 * 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();
}

4044
static int process_backlog(struct napi_struct *napi, int quota)
L
Linus Torvalds 已提交
4045 4046
{
	int work = 0;
E
Eric Dumazet 已提交
4047
	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
L
Linus Torvalds 已提交
4048

4049 4050 4051 4052 4053 4054 4055 4056 4057
#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
4058
	napi->weight = weight_p;
4059 4060
	local_irq_disable();
	while (work < quota) {
L
Linus Torvalds 已提交
4061
		struct sk_buff *skb;
4062 4063 4064 4065 4066 4067
		unsigned int qlen;

		while ((skb = __skb_dequeue(&sd->process_queue))) {
			local_irq_enable();
			__netif_receive_skb(skb);
			local_irq_disable();
4068 4069 4070 4071 4072
			input_queue_head_incr(sd);
			if (++work >= quota) {
				local_irq_enable();
				return work;
			}
4073
		}
L
Linus Torvalds 已提交
4074

E
Eric Dumazet 已提交
4075
		rps_lock(sd);
4076
		qlen = skb_queue_len(&sd->input_pkt_queue);
4077
		if (qlen)
4078 4079
			skb_queue_splice_tail_init(&sd->input_pkt_queue,
						   &sd->process_queue);
4080

4081
		if (qlen < quota - work) {
E
Eric Dumazet 已提交
4082 4083 4084 4085 4086 4087 4088 4089 4090 4091
			/*
			 * 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;

4092
			quota = work + qlen;
4093
		}
E
Eric Dumazet 已提交
4094
		rps_unlock(sd);
4095 4096
	}
	local_irq_enable();
L
Linus Torvalds 已提交
4097

4098 4099
	return work;
}
L
Linus Torvalds 已提交
4100

4101 4102
/**
 * __napi_schedule - schedule for receive
4103
 * @n: entry to schedule
4104 4105 4106
 *
 * The entry's receive function will be scheduled to run
 */
H
Harvey Harrison 已提交
4107
void __napi_schedule(struct napi_struct *n)
4108 4109
{
	unsigned long flags;
L
Linus Torvalds 已提交
4110

4111
	local_irq_save(flags);
E
Eric Dumazet 已提交
4112
	____napi_schedule(&__get_cpu_var(softnet_data), n);
4113
	local_irq_restore(flags);
L
Linus Torvalds 已提交
4114
}
4115 4116
EXPORT_SYMBOL(__napi_schedule);

4117 4118 4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136 4137 4138
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;

4139
	napi_gro_flush(n, false);
4140 4141 4142 4143 4144 4145
	local_irq_save(flags);
	__napi_complete(n);
	local_irq_restore(flags);
}
EXPORT_SYMBOL(napi_complete);

E
Eliezer Tamir 已提交
4146 4147 4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176 4177 4178 4179 4180 4181 4182 4183 4184 4185 4186 4187 4188 4189 4190 4191 4192 4193 4194 4195 4196 4197
/* 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);

4198 4199 4200 4201
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);
4202
	napi->gro_count = 0;
4203
	napi->gro_list = NULL;
H
Herbert Xu 已提交
4204
	napi->skb = NULL;
4205
	napi->poll = poll;
E
Eric Dumazet 已提交
4206 4207 4208
	if (weight > NAPI_POLL_WEIGHT)
		pr_err_once("netif_napi_add() called with weight %d on device %s\n",
			    weight, dev->name);
4209 4210 4211
	napi->weight = weight;
	list_add(&napi->dev_list, &dev->napi_list);
	napi->dev = dev;
H
Herbert Xu 已提交
4212
#ifdef CONFIG_NETPOLL
4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223
	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;

4224
	list_del_init(&napi->dev_list);
4225
	napi_free_frags(napi);
4226 4227 4228 4229 4230 4231 4232 4233

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

	napi->gro_list = NULL;
4234
	napi->gro_count = 0;
4235 4236 4237
}
EXPORT_SYMBOL(netif_napi_del);

L
Linus Torvalds 已提交
4238 4239
static void net_rx_action(struct softirq_action *h)
{
4240
	struct softnet_data *sd = &__get_cpu_var(softnet_data);
4241
	unsigned long time_limit = jiffies + 2;
4242
	int budget = netdev_budget;
4243 4244
	void *have;

L
Linus Torvalds 已提交
4245 4246
	local_irq_disable();

4247
	while (!list_empty(&sd->poll_list)) {
4248 4249
		struct napi_struct *n;
		int work, weight;
L
Linus Torvalds 已提交
4250

4251
		/* If softirq window is exhuasted then punt.
4252 4253
		 * Allow this to run for 2 jiffies since which will allow
		 * an average latency of 1.5/HZ.
4254
		 */
4255
		if (unlikely(budget <= 0 || time_after_eq(jiffies, time_limit)))
L
Linus Torvalds 已提交
4256 4257 4258 4259
			goto softnet_break;

		local_irq_enable();

4260 4261 4262 4263 4264
		/* 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.
		 */
4265
		n = list_first_entry(&sd->poll_list, struct napi_struct, poll_list);
L
Linus Torvalds 已提交
4266

4267 4268 4269 4270
		have = netpoll_poll_lock(n);

		weight = n->weight;

4271 4272 4273 4274
		/* 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
4275
		 * accidentally calling ->poll() when NAPI is not scheduled.
4276 4277
		 */
		work = 0;
4278
		if (test_bit(NAPI_STATE_SCHED, &n->state)) {
4279
			work = n->poll(n, weight);
4280 4281
			trace_napi_poll(n);
		}
4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292 4293

		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.
		 */
4294
		if (unlikely(work == weight)) {
4295 4296 4297 4298
			if (unlikely(napi_disable_pending(n))) {
				local_irq_enable();
				napi_complete(n);
				local_irq_disable();
4299 4300 4301 4302 4303 4304 4305 4306 4307
			} 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();
				}
4308
				list_move_tail(&n->poll_list, &sd->poll_list);
4309
			}
4310
		}
4311 4312

		netpoll_poll_unlock(have);
L
Linus Torvalds 已提交
4313 4314
	}
out:
4315
	net_rps_action_and_irq_enable(sd);
T
Tom Herbert 已提交
4316

4317 4318 4319 4320 4321
#ifdef CONFIG_NET_DMA
	/*
	 * There may not be any more sk_buffs coming right now, so push
	 * any pending DMA copies to hardware
	 */
4322
	dma_issue_pending_all();
4323
#endif
4324

L
Linus Torvalds 已提交
4325 4326 4327
	return;

softnet_break:
C
Changli Gao 已提交
4328
	sd->time_squeeze++;
L
Linus Torvalds 已提交
4329 4330 4331 4332
	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
	goto out;
}

J
Jiri Pirko 已提交
4333 4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363 4364 4365 4366 4367 4368 4369 4370 4371 4372 4373 4374 4375 4376 4377 4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404 4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424 4425 4426 4427 4428 4429 4430 4431 4432 4433 4434 4435 4436 4437 4438 4439 4440 4441 4442 4443 4444 4445 4446 4447 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 4490 4491 4492 4493 4494 4495
struct netdev_upper {
	struct net_device *dev;
	bool master;
	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)
{
	struct netdev_upper *upper;

	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);
	struct netdev_upper *upper;
	struct netdev_upper *tmp;
	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;
}

static struct netdev_upper *__netdev_find_upper(struct net_device *dev,
						struct net_device *upper_dev)
{
	struct netdev_upper *upper;

	list_for_each_entry(upper, &dev->upper_dev_list, list) {
		if (upper->dev == upper_dev)
			return upper;
	}
	return NULL;
}

/**
 * netdev_has_upper_dev - Check if device is linked to an upper device
 * @dev: device
 * @upper_dev: upper device to check
 *
 * Find out if a device is linked to specified upper device and return true
 * in case it is. Note that this checks only immediate upper device,
 * not through a complete stack of devices. The caller must hold the RTNL lock.
 */
bool netdev_has_upper_dev(struct net_device *dev,
			  struct net_device *upper_dev)
{
	ASSERT_RTNL();

	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)
{
	struct netdev_upper *upper;

	ASSERT_RTNL();

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

	upper = list_first_entry(&dev->upper_dev_list,
				 struct netdev_upper, list);
	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)
{
	struct netdev_upper *upper;

	upper = list_first_or_null_rcu(&dev->upper_dev_list,
				       struct netdev_upper, list);
	if (upper && likely(upper->master))
		return upper->dev;
	return NULL;
}
EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);

static int __netdev_upper_dev_link(struct net_device *dev,
				   struct net_device *upper_dev, bool master)
{
	struct netdev_upper *upper;

	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;

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

	upper->dev = upper_dev;
	upper->master = master;
	INIT_LIST_HEAD(&upper->search_list);

	/* Ensure that master upper link is always the first item in list. */
	if (master)
		list_add_rcu(&upper->list, &dev->upper_dev_list);
	else
		list_add_tail_rcu(&upper->list, &dev->upper_dev_list);
	dev_hold(upper_dev);
4496
	call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev);
J
Jiri Pirko 已提交
4497 4498 4499 4500 4501 4502 4503 4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515 4516 4517 4518 4519 4520 4521 4522 4523 4524 4525 4526 4527 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537 4538 4539 4540 4541 4542 4543 4544 4545 4546 4547 4548 4549 4550 4551 4552 4553 4554 4555
	return 0;
}

/**
 * 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)
{
	struct netdev_upper *upper;

	ASSERT_RTNL();

	upper = __netdev_find_upper(dev, upper_dev);
	if (!upper)
		return;
	list_del_rcu(&upper->list);
	dev_put(upper_dev);
	kfree_rcu(upper, rcu);
4556
	call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev);
J
Jiri Pirko 已提交
4557 4558 4559
}
EXPORT_SYMBOL(netdev_upper_dev_unlink);

4560 4561
static void dev_change_rx_flags(struct net_device *dev, int flags)
{
4562 4563 4564 4565
	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);
4566 4567
}

4568
static int __dev_set_promiscuity(struct net_device *dev, int inc)
L
Linus Torvalds 已提交
4569
{
4570
	unsigned int old_flags = dev->flags;
4571 4572
	kuid_t uid;
	kgid_t gid;
L
Linus Torvalds 已提交
4573

4574 4575
	ASSERT_RTNL();

4576 4577 4578 4579 4580 4581 4582 4583 4584 4585 4586
	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;
4587 4588
			pr_warn("%s: promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n",
				dev->name);
4589 4590 4591
			return -EOVERFLOW;
		}
	}
4592
	if (dev->flags != old_flags) {
4593 4594 4595
		pr_info("device %s %s promiscuous mode\n",
			dev->name,
			dev->flags & IFF_PROMISC ? "entered" : "left");
4596 4597
		if (audit_enabled) {
			current_uid_gid(&uid, &gid);
4598 4599 4600 4601 4602
			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),
4603
				from_kuid(&init_user_ns, audit_get_loginuid(current)),
4604 4605
				from_kuid(&init_user_ns, uid),
				from_kgid(&init_user_ns, gid),
4606
				audit_get_sessionid(current));
4607
		}
4608

4609
		dev_change_rx_flags(dev, IFF_PROMISC);
L
Linus Torvalds 已提交
4610
	}
4611
	return 0;
L
Linus Torvalds 已提交
4612 4613
}

4614 4615 4616 4617 4618 4619 4620 4621 4622
/**
 *	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.
4623
 *	Return 0 if successful or a negative errno code on error.
4624
 */
4625
int dev_set_promiscuity(struct net_device *dev, int inc)
4626
{
4627
	unsigned int old_flags = dev->flags;
4628
	int err;
4629

4630
	err = __dev_set_promiscuity(dev, inc);
4631
	if (err < 0)
4632
		return err;
4633 4634
	if (dev->flags != old_flags)
		dev_set_rx_mode(dev);
4635
	return err;
4636
}
E
Eric Dumazet 已提交
4637
EXPORT_SYMBOL(dev_set_promiscuity);
4638

L
Linus Torvalds 已提交
4639 4640 4641 4642 4643 4644 4645 4646 4647 4648
/**
 *	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.
4649
 *	Return 0 if successful or a negative errno code on error.
L
Linus Torvalds 已提交
4650 4651
 */

4652
int dev_set_allmulti(struct net_device *dev, int inc)
L
Linus Torvalds 已提交
4653
{
4654
	unsigned int old_flags = dev->flags;
L
Linus Torvalds 已提交
4655

4656 4657
	ASSERT_RTNL();

L
Linus Torvalds 已提交
4658
	dev->flags |= IFF_ALLMULTI;
4659 4660 4661 4662 4663 4664 4665 4666 4667 4668
	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;
4669 4670
			pr_warn("%s: allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n",
				dev->name);
4671 4672 4673
			return -EOVERFLOW;
		}
	}
4674
	if (dev->flags ^ old_flags) {
4675
		dev_change_rx_flags(dev, IFF_ALLMULTI);
4676
		dev_set_rx_mode(dev);
4677
	}
4678
	return 0;
4679
}
E
Eric Dumazet 已提交
4680
EXPORT_SYMBOL(dev_set_allmulti);
4681 4682 4683 4684

/*
 *	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
4685
 *	filtering it is put in promiscuous mode while unicast addresses
4686 4687 4688 4689
 *	are present.
 */
void __dev_set_rx_mode(struct net_device *dev)
{
4690 4691
	const struct net_device_ops *ops = dev->netdev_ops;

4692 4693 4694 4695 4696
	/* dev_open will call this function so the list will stay sane. */
	if (!(dev->flags&IFF_UP))
		return;

	if (!netif_device_present(dev))
4697
		return;
4698

4699
	if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
4700 4701 4702
		/* Unicast addresses changes may only happen under the rtnl,
		 * therefore calling __dev_set_promiscuity here is safe.
		 */
4703
		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
4704
			__dev_set_promiscuity(dev, 1);
4705
			dev->uc_promisc = true;
4706
		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
4707
			__dev_set_promiscuity(dev, -1);
4708
			dev->uc_promisc = false;
4709 4710
		}
	}
4711 4712 4713

	if (ops->ndo_set_rx_mode)
		ops->ndo_set_rx_mode(dev);
4714 4715 4716 4717
}

void dev_set_rx_mode(struct net_device *dev)
{
4718
	netif_addr_lock_bh(dev);
4719
	__dev_set_rx_mode(dev);
4720
	netif_addr_unlock_bh(dev);
L
Linus Torvalds 已提交
4721 4722
}

4723 4724 4725 4726 4727 4728
/**
 *	dev_get_flags - get flags reported to userspace
 *	@dev: device
 *
 *	Get the combination of flag bits exported through APIs to userspace.
 */
4729
unsigned int dev_get_flags(const struct net_device *dev)
L
Linus Torvalds 已提交
4730
{
4731
	unsigned int flags;
L
Linus Torvalds 已提交
4732 4733 4734

	flags = (dev->flags & ~(IFF_PROMISC |
				IFF_ALLMULTI |
S
Stefan Rompf 已提交
4735 4736 4737
				IFF_RUNNING |
				IFF_LOWER_UP |
				IFF_DORMANT)) |
L
Linus Torvalds 已提交
4738 4739 4740
		(dev->gflags & (IFF_PROMISC |
				IFF_ALLMULTI));

S
Stefan Rompf 已提交
4741 4742 4743 4744 4745 4746 4747 4748
	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
4749 4750 4751

	return flags;
}
E
Eric Dumazet 已提交
4752
EXPORT_SYMBOL(dev_get_flags);
L
Linus Torvalds 已提交
4753

4754
int __dev_change_flags(struct net_device *dev, unsigned int flags)
L
Linus Torvalds 已提交
4755
{
4756
	unsigned int old_flags = dev->flags;
4757
	int ret;
L
Linus Torvalds 已提交
4758

4759 4760
	ASSERT_RTNL();

L
Linus Torvalds 已提交
4761 4762 4763 4764 4765 4766 4767 4768 4769 4770 4771 4772 4773 4774
	/*
	 *	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.
	 */

4775 4776
	if ((old_flags ^ flags) & IFF_MULTICAST)
		dev_change_rx_flags(dev, IFF_MULTICAST);
4777

4778
	dev_set_rx_mode(dev);
L
Linus Torvalds 已提交
4779 4780 4781 4782 4783 4784 4785 4786 4787

	/*
	 *	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  ? */
4788
		ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev);
L
Linus Torvalds 已提交
4789 4790

		if (!ret)
4791
			dev_set_rx_mode(dev);
L
Linus Torvalds 已提交
4792 4793 4794
	}

	if ((flags ^ dev->gflags) & IFF_PROMISC) {
E
Eric Dumazet 已提交
4795 4796
		int inc = (flags & IFF_PROMISC) ? 1 : -1;

L
Linus Torvalds 已提交
4797 4798 4799 4800 4801 4802 4803 4804 4805
		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
4806 4807
		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;

L
Linus Torvalds 已提交
4808 4809 4810 4811
		dev->gflags ^= IFF_ALLMULTI;
		dev_set_allmulti(dev, inc);
	}

4812 4813 4814 4815 4816 4817 4818 4819 4820 4821 4822 4823 4824 4825 4826
	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 &&
4827 4828 4829 4830 4831 4832 4833
	    (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);
	}
4834 4835 4836 4837 4838 4839 4840 4841 4842 4843
}

/**
 *	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.
 */
4844
int dev_change_flags(struct net_device *dev, unsigned int flags)
4845
{
4846 4847
	int ret;
	unsigned int changes, old_flags = dev->flags;
4848 4849 4850 4851 4852 4853

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

	changes = old_flags ^ dev->flags;
4854 4855
	if (changes)
		rtmsg_ifinfo(RTM_NEWLINK, dev, changes);
L
Linus Torvalds 已提交
4856

4857
	__dev_notify_flags(dev, old_flags);
L
Linus Torvalds 已提交
4858 4859
	return ret;
}
E
Eric Dumazet 已提交
4860
EXPORT_SYMBOL(dev_change_flags);
L
Linus Torvalds 已提交
4861

4862 4863 4864 4865 4866 4867 4868
/**
 *	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
4869 4870
int dev_set_mtu(struct net_device *dev, int new_mtu)
{
4871
	const struct net_device_ops *ops = dev->netdev_ops;
L
Linus Torvalds 已提交
4872 4873 4874 4875 4876 4877 4878 4879 4880 4881 4882 4883 4884
	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;
4885 4886
	if (ops->ndo_change_mtu)
		err = ops->ndo_change_mtu(dev, new_mtu);
L
Linus Torvalds 已提交
4887 4888
	else
		dev->mtu = new_mtu;
4889

4890
	if (!err)
4891
		call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
L
Linus Torvalds 已提交
4892 4893
	return err;
}
E
Eric Dumazet 已提交
4894
EXPORT_SYMBOL(dev_set_mtu);
L
Linus Torvalds 已提交
4895

4896 4897 4898 4899 4900 4901 4902 4903 4904 4905 4906
/**
 *	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);

4907 4908 4909 4910 4911 4912 4913
/**
 *	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
4914 4915
int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
{
4916
	const struct net_device_ops *ops = dev->netdev_ops;
L
Linus Torvalds 已提交
4917 4918
	int err;

4919
	if (!ops->ndo_set_mac_address)
L
Linus Torvalds 已提交
4920 4921 4922 4923 4924
		return -EOPNOTSUPP;
	if (sa->sa_family != dev->type)
		return -EINVAL;
	if (!netif_device_present(dev))
		return -ENODEV;
4925
	err = ops->ndo_set_mac_address(dev, sa);
4926 4927
	if (err)
		return err;
J
Jiri Pirko 已提交
4928
	dev->addr_assign_type = NET_ADDR_SET;
4929
	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
4930
	add_device_randomness(dev->dev_addr, dev->addr_len);
4931
	return 0;
L
Linus Torvalds 已提交
4932
}
E
Eric Dumazet 已提交
4933
EXPORT_SYMBOL(dev_set_mac_address);
L
Linus Torvalds 已提交
4934

J
Jiri Pirko 已提交
4935 4936 4937
/**
 *	dev_change_carrier - Change device carrier
 *	@dev: device
4938
 *	@new_carrier: new value
J
Jiri Pirko 已提交
4939 4940 4941 4942 4943 4944 4945 4946 4947 4948 4949 4950 4951 4952 4953
 *
 *	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);

L
Linus Torvalds 已提交
4954 4955
/**
 *	dev_new_index	-	allocate an ifindex
4956
 *	@net: the applicable net namespace
L
Linus Torvalds 已提交
4957 4958 4959 4960 4961
 *
 *	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.
 */
4962
static int dev_new_index(struct net *net)
L
Linus Torvalds 已提交
4963
{
4964
	int ifindex = net->ifindex;
L
Linus Torvalds 已提交
4965 4966 4967
	for (;;) {
		if (++ifindex <= 0)
			ifindex = 1;
4968
		if (!__dev_get_by_index(net, ifindex))
4969
			return net->ifindex = ifindex;
L
Linus Torvalds 已提交
4970 4971 4972 4973
	}
}

/* Delayed registration/unregisteration */
4974
static LIST_HEAD(net_todo_list);
L
Linus Torvalds 已提交
4975

4976
static void net_set_todo(struct net_device *dev)
L
Linus Torvalds 已提交
4977 4978 4979 4980
{
	list_add_tail(&dev->todo_list, &net_todo_list);
}

4981
static void rollback_registered_many(struct list_head *head)
4982
{
4983
	struct net_device *dev, *tmp;
4984

4985 4986 4987
	BUG_ON(dev_boot_phase);
	ASSERT_RTNL();

4988
	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
4989
		/* Some devices call without registering
4990 4991
		 * for initialization unwind. Remove those
		 * devices and proceed with the remaining.
4992 4993
		 */
		if (dev->reg_state == NETREG_UNINITIALIZED) {
4994 4995
			pr_debug("unregister_netdevice: device %s/%p never was registered\n",
				 dev->name, dev);
4996

4997
			WARN_ON(1);
4998 4999
			list_del(&dev->unreg_list);
			continue;
5000
		}
5001
		dev->dismantle = true;
5002
		BUG_ON(dev->reg_state != NETREG_REGISTERED);
5003
	}
5004

5005 5006
	/* If device is running, close it first. */
	dev_close_many(head);
5007

5008
	list_for_each_entry(dev, head, unreg_list) {
5009 5010
		/* And unlink it from device chain. */
		unlist_netdevice(dev);
5011

5012 5013
		dev->reg_state = NETREG_UNREGISTERING;
	}
5014 5015 5016

	synchronize_net();

5017 5018 5019
	list_for_each_entry(dev, head, unreg_list) {
		/* Shutdown queueing discipline. */
		dev_shutdown(dev);
5020 5021


5022 5023 5024 5025
		/* Notify protocols, that we are about to destroy
		   this device. They should clean all the things.
		*/
		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5026

5027 5028 5029 5030
		if (!dev->rtnl_link_ops ||
		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
			rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);

5031 5032 5033
		/*
		 *	Flush the unicast and multicast chains
		 */
5034
		dev_uc_flush(dev);
5035
		dev_mc_flush(dev);
5036

5037 5038
		if (dev->netdev_ops->ndo_uninit)
			dev->netdev_ops->ndo_uninit(dev);
5039

J
Jiri Pirko 已提交
5040 5041
		/* Notifier chain MUST detach us all upper devices. */
		WARN_ON(netdev_has_any_upper_dev(dev));
5042

5043 5044
		/* Remove entries from kobject tree */
		netdev_unregister_kobject(dev);
5045 5046 5047 5048
#ifdef CONFIG_XPS
		/* Remove XPS queueing entries */
		netif_reset_xps_queues_gt(dev, 0);
#endif
5049
	}
5050

5051
	synchronize_net();
5052

5053
	list_for_each_entry(dev, head, unreg_list)
5054 5055 5056 5057 5058 5059 5060 5061 5062
		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
5063
	list_del(&single);
5064 5065
}

5066 5067
static netdev_features_t netdev_fix_features(struct net_device *dev,
	netdev_features_t features)
5068
{
5069 5070 5071
	/* Fix illegal checksum combinations */
	if ((features & NETIF_F_HW_CSUM) &&
	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5072
		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
5073 5074 5075
		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
	}

5076
	/* TSO requires that SG is present as well. */
5077
	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
5078
		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
5079
		features &= ~NETIF_F_ALL_TSO;
5080 5081
	}

5082 5083 5084 5085 5086 5087 5088 5089 5090 5091 5092 5093 5094
	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;
	}

5095 5096 5097 5098
	/* TSO ECN requires that TSO is present as well. */
	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
		features &= ~NETIF_F_TSO_ECN;

5099 5100
	/* Software GSO depends on SG. */
	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
5101
		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
5102 5103 5104
		features &= ~NETIF_F_GSO;
	}

5105
	/* UFO needs SG and checksumming */
5106
	if (features & NETIF_F_UFO) {
5107 5108 5109 5110
		/* 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))) {
5111
			netdev_dbg(dev,
5112
				"Dropping NETIF_F_UFO since no checksum offload features.\n");
5113 5114 5115 5116
			features &= ~NETIF_F_UFO;
		}

		if (!(features & NETIF_F_SG)) {
5117
			netdev_dbg(dev,
5118
				"Dropping NETIF_F_UFO since no NETIF_F_SG feature.\n");
5119 5120 5121 5122 5123 5124 5125
			features &= ~NETIF_F_UFO;
		}
	}

	return features;
}

5126
int __netdev_update_features(struct net_device *dev)
5127
{
5128
	netdev_features_t features;
5129 5130
	int err = 0;

5131 5132
	ASSERT_RTNL();

5133 5134 5135 5136 5137 5138 5139 5140 5141
	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)
5142
		return 0;
5143

5144 5145
	netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
		&dev->features, &features);
5146 5147 5148 5149

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

5150
	if (unlikely(err < 0)) {
5151
		netdev_err(dev,
5152 5153
			"set_features() failed (%d); wanted %pNF, left %pNF\n",
			err, &features, &dev->features);
5154 5155 5156 5157 5158 5159 5160 5161 5162
		return -1;
	}

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

	return 1;
}

5163 5164 5165 5166 5167 5168 5169 5170
/**
 *	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.
 */
5171 5172 5173 5174
void netdev_update_features(struct net_device *dev)
{
	if (__netdev_update_features(dev))
		netdev_features_change(dev);
5175 5176 5177
}
EXPORT_SYMBOL(netdev_update_features);

5178 5179 5180 5181 5182 5183 5184 5185 5186 5187 5188 5189 5190 5191 5192 5193 5194
/**
 *	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);

5195 5196 5197 5198 5199 5200 5201 5202 5203 5204 5205 5206 5207 5208 5209 5210 5211 5212 5213 5214 5215 5216 5217 5218 5219 5220 5221
/**
 *	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
5222
#ifdef CONFIG_RPS
5223 5224 5225
static int netif_alloc_rx_queues(struct net_device *dev)
{
	unsigned int i, count = dev->num_rx_queues;
T
Tom Herbert 已提交
5226
	struct netdev_rx_queue *rx;
5227

T
Tom Herbert 已提交
5228
	BUG_ON(count < 1);
5229

T
Tom Herbert 已提交
5230
	rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL);
5231
	if (!rx)
T
Tom Herbert 已提交
5232
		return -ENOMEM;
5233

T
Tom Herbert 已提交
5234 5235 5236
	dev->_rx = rx;

	for (i = 0; i < count; i++)
T
Tom Herbert 已提交
5237
		rx[i].dev = dev;
5238 5239
	return 0;
}
T
Tom Herbert 已提交
5240
#endif
5241

C
Changli Gao 已提交
5242 5243 5244 5245 5246 5247 5248
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;
5249
	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
C
Changli Gao 已提交
5250
	queue->dev = dev;
T
Tom Herbert 已提交
5251 5252 5253
#ifdef CONFIG_BQL
	dql_init(&queue->dql, HZ);
#endif
C
Changli Gao 已提交
5254 5255
}

5256 5257 5258 5259 5260 5261 5262 5263
static int netif_alloc_netdev_queues(struct net_device *dev)
{
	unsigned int count = dev->num_tx_queues;
	struct netdev_queue *tx;

	BUG_ON(count < 1);

	tx = kcalloc(count, sizeof(struct netdev_queue), GFP_KERNEL);
5264
	if (!tx)
5265
		return -ENOMEM;
5266

5267
	dev->_tx = tx;
T
Tom Herbert 已提交
5268

5269 5270
	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
	spin_lock_init(&dev->tx_global_lock);
C
Changli Gao 已提交
5271 5272

	return 0;
5273 5274
}

L
Linus Torvalds 已提交
5275 5276 5277 5278 5279 5280 5281 5282 5283 5284 5285 5286 5287 5288 5289 5290 5291 5292 5293 5294
/**
 *	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;
5295
	struct net *net = dev_net(dev);
L
Linus Torvalds 已提交
5296 5297 5298 5299

	BUG_ON(dev_boot_phase);
	ASSERT_RTNL();

5300 5301
	might_sleep();

L
Linus Torvalds 已提交
5302 5303
	/* When net_device's are persistent, this will be fatal. */
	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
5304
	BUG_ON(!net);
L
Linus Torvalds 已提交
5305

5306
	spin_lock_init(&dev->addr_list_lock);
5307
	netdev_set_addr_lockdep_class(dev);
L
Linus Torvalds 已提交
5308 5309 5310

	dev->iflink = -1;

5311
	ret = dev_get_valid_name(net, dev, dev->name);
5312 5313 5314
	if (ret < 0)
		goto out;

L
Linus Torvalds 已提交
5315
	/* Init, if this function is available */
5316 5317
	if (dev->netdev_ops->ndo_init) {
		ret = dev->netdev_ops->ndo_init(dev);
L
Linus Torvalds 已提交
5318 5319 5320
		if (ret) {
			if (ret > 0)
				ret = -EIO;
5321
			goto out;
L
Linus Torvalds 已提交
5322 5323
		}
	}
5324

5325 5326
	if (((dev->hw_features | dev->features) &
	     NETIF_F_HW_VLAN_CTAG_FILTER) &&
5327 5328 5329 5330 5331 5332 5333
	    (!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;
	}

5334 5335 5336 5337 5338 5339
	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
5340 5341 5342
	if (dev->iflink == -1)
		dev->iflink = dev->ifindex;

5343 5344 5345 5346
	/* Transfer changeable features to wanted_features and enable
	 * software offloads (GSO and GRO).
	 */
	dev->hw_features |= NETIF_F_SOFT_FEATURES;
5347 5348
	dev->features |= NETIF_F_SOFT_FEATURES;
	dev->wanted_features = dev->features & dev->hw_features;
L
Linus Torvalds 已提交
5349

5350
	/* Turn on no cache copy if HW is doing checksum */
5351 5352 5353 5354 5355 5356
	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;
		}
5357 5358
	}

5359
	/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
5360
	 */
5361
	dev->vlan_features |= NETIF_F_HIGHDMA;
5362

5363 5364 5365 5366
	/* Make NETIF_F_SG inheritable to tunnel devices.
	 */
	dev->hw_enc_features |= NETIF_F_SG;

S
Simon Horman 已提交
5367 5368 5369 5370
	/* Make NETIF_F_SG inheritable to MPLS.
	 */
	dev->mpls_features |= NETIF_F_SG;

5371 5372 5373 5374 5375
	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
	ret = notifier_to_errno(ret);
	if (ret)
		goto err_uninit;

5376
	ret = netdev_register_kobject(dev);
5377
	if (ret)
5378
		goto err_uninit;
5379 5380
	dev->reg_state = NETREG_REGISTERED;

5381
	__netdev_update_features(dev);
5382

L
Linus Torvalds 已提交
5383 5384 5385 5386 5387 5388 5389
	/*
	 *	Default initial state at registry is that the
	 *	device is present.
	 */

	set_bit(__LINK_STATE_PRESENT, &dev->state);

5390 5391
	linkwatch_init_dev(dev);

L
Linus Torvalds 已提交
5392 5393
	dev_init_scheduler(dev);
	dev_hold(dev);
5394
	list_netdevice(dev);
5395
	add_device_randomness(dev->dev_addr, dev->addr_len);
L
Linus Torvalds 已提交
5396

5397 5398 5399 5400 5401 5402 5403
	/* 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
5404
	/* Notify protocols, that a new device appeared. */
5405
	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
5406
	ret = notifier_to_errno(ret);
5407 5408 5409 5410
	if (ret) {
		rollback_registered(dev);
		dev->reg_state = NETREG_UNREGISTERED;
	}
5411 5412 5413 5414
	/*
	 *	Prevent userspace races by waiting until the network
	 *	device is fully setup before sending notifications.
	 */
5415 5416 5417
	if (!dev->rtnl_link_ops ||
	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
L
Linus Torvalds 已提交
5418 5419 5420

out:
	return ret;
5421 5422

err_uninit:
5423 5424
	if (dev->netdev_ops->ndo_uninit)
		dev->netdev_ops->ndo_uninit(dev);
5425
	goto out;
L
Linus Torvalds 已提交
5426
}
E
Eric Dumazet 已提交
5427
EXPORT_SYMBOL(register_netdevice);
L
Linus Torvalds 已提交
5428

5429 5430 5431 5432 5433 5434 5435 5436 5437 5438 5439 5440 5441 5442 5443 5444 5445 5446 5447 5448 5449 5450 5451 5452 5453 5454 5455 5456 5457 5458 5459
/**
 *	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
5460 5461 5462 5463 5464
	/* Note : We dont allocate pcpu_refcnt for dummy devices,
	 * because users of this 'device' dont need to change
	 * its refcount.
	 */

5465 5466 5467 5468 5469
	return 0;
}
EXPORT_SYMBOL_GPL(init_dummy_netdev);


L
Linus Torvalds 已提交
5470 5471 5472 5473 5474 5475 5476 5477 5478
/**
 *	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.
 *
5479
 *	This is a wrapper around register_netdevice that takes the rtnl semaphore
L
Linus Torvalds 已提交
5480 5481 5482 5483 5484 5485 5486 5487 5488 5489 5490 5491 5492 5493
 *	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
5494 5495 5496 5497 5498 5499 5500 5501 5502 5503
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);

5504
/**
L
Linus Torvalds 已提交
5505
 * netdev_wait_allrefs - wait until all references are gone.
5506
 * @dev: target net_device
L
Linus Torvalds 已提交
5507 5508 5509 5510 5511 5512 5513
 *
 * 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
5514
 * call dev_put.
L
Linus Torvalds 已提交
5515 5516 5517 5518
 */
static void netdev_wait_allrefs(struct net_device *dev)
{
	unsigned long rebroadcast_time, warning_time;
E
Eric Dumazet 已提交
5519
	int refcnt;
L
Linus Torvalds 已提交
5520

5521 5522
	linkwatch_forget_dev(dev);

L
Linus Torvalds 已提交
5523
	rebroadcast_time = warning_time = jiffies;
E
Eric Dumazet 已提交
5524 5525 5526
	refcnt = netdev_refcnt_read(dev);

	while (refcnt != 0) {
L
Linus Torvalds 已提交
5527
		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
5528
			rtnl_lock();
L
Linus Torvalds 已提交
5529 5530

			/* Rebroadcast unregister notification */
5531
			call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
L
Linus Torvalds 已提交
5532

5533
			__rtnl_unlock();
5534
			rcu_barrier();
5535 5536
			rtnl_lock();

5537
			call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
L
Linus Torvalds 已提交
5538 5539 5540 5541 5542 5543 5544 5545 5546 5547 5548
			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();
			}

5549
			__rtnl_unlock();
L
Linus Torvalds 已提交
5550 5551 5552 5553 5554 5555

			rebroadcast_time = jiffies;
		}

		msleep(250);

E
Eric Dumazet 已提交
5556 5557
		refcnt = netdev_refcnt_read(dev);

L
Linus Torvalds 已提交
5558
		if (time_after(jiffies, warning_time + 10 * HZ)) {
5559 5560
			pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
				 dev->name, refcnt);
L
Linus Torvalds 已提交
5561 5562 5563 5564 5565 5566 5567 5568 5569 5570 5571 5572 5573 5574 5575 5576 5577 5578 5579
			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
5580
 * We are invoked by rtnl_unlock().
L
Linus Torvalds 已提交
5581
 * This allows us to deal with problems:
5582
 * 1) We can delete sysfs objects which invoke hotplug
L
Linus Torvalds 已提交
5583 5584 5585
 *    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
5586 5587 5588
 *
 * 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
5589 5590 5591
 */
void netdev_run_todo(void)
{
5592
	struct list_head list;
L
Linus Torvalds 已提交
5593 5594

	/* Snapshot list, allow later requests */
5595
	list_replace_init(&net_todo_list, &list);
H
Herbert Xu 已提交
5596 5597

	__rtnl_unlock();
5598

5599 5600

	/* Wait for rcu callbacks to finish before next phase */
5601 5602 5603
	if (!list_empty(&list))
		rcu_barrier();

L
Linus Torvalds 已提交
5604 5605
	while (!list_empty(&list)) {
		struct net_device *dev
5606
			= list_first_entry(&list, struct net_device, todo_list);
L
Linus Torvalds 已提交
5607 5608
		list_del(&dev->todo_list);

5609
		rtnl_lock();
5610
		call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
5611
		__rtnl_unlock();
5612

5613
		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
5614
			pr_err("network todo '%s' but state %d\n",
5615 5616 5617 5618
			       dev->name, dev->reg_state);
			dump_stack();
			continue;
		}
L
Linus Torvalds 已提交
5619

5620
		dev->reg_state = NETREG_UNREGISTERED;
L
Linus Torvalds 已提交
5621

5622
		on_each_cpu(flush_backlog, dev, 1);
5623

5624
		netdev_wait_allrefs(dev);
L
Linus Torvalds 已提交
5625

5626
		/* paranoia */
E
Eric Dumazet 已提交
5627
		BUG_ON(netdev_refcnt_read(dev));
5628 5629
		WARN_ON(rcu_access_pointer(dev->ip_ptr));
		WARN_ON(rcu_access_pointer(dev->ip6_ptr));
5630
		WARN_ON(dev->dn_ptr);
L
Linus Torvalds 已提交
5631

5632 5633
		if (dev->destructor)
			dev->destructor(dev);
5634 5635 5636

		/* Free network device */
		kobject_put(&dev->dev.kobj);
L
Linus Torvalds 已提交
5637 5638 5639
	}
}

5640 5641 5642
/* Convert net_device_stats to rtnl_link_stats64.  They have the same
 * fields in the same order, with only the type differing.
 */
5643 5644
void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
			     const struct net_device_stats *netdev_stats)
5645 5646
{
#if BITS_PER_LONG == 64
5647 5648
	BUILD_BUG_ON(sizeof(*stats64) != sizeof(*netdev_stats));
	memcpy(stats64, netdev_stats, sizeof(*stats64));
5649 5650 5651 5652 5653 5654 5655 5656 5657 5658 5659
#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
}
5660
EXPORT_SYMBOL(netdev_stats_to_stats64);
5661

5662 5663 5664
/**
 *	dev_get_stats	- get network device statistics
 *	@dev: device to get statistics from
5665
 *	@storage: place to store stats
5666
 *
5667 5668 5669 5670
 *	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.
5671
 */
5672 5673
struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
					struct rtnl_link_stats64 *storage)
5674
{
5675 5676
	const struct net_device_ops *ops = dev->netdev_ops;

5677 5678
	if (ops->ndo_get_stats64) {
		memset(storage, 0, sizeof(*storage));
5679 5680
		ops->ndo_get_stats64(dev, storage);
	} else if (ops->ndo_get_stats) {
5681
		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
5682 5683
	} else {
		netdev_stats_to_stats64(storage, &dev->stats);
5684
	}
5685
	storage->rx_dropped += atomic_long_read(&dev->rx_dropped);
5686
	return storage;
R
Rusty Russell 已提交
5687
}
5688
EXPORT_SYMBOL(dev_get_stats);
R
Rusty Russell 已提交
5689

5690
struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
5691
{
5692
	struct netdev_queue *queue = dev_ingress_queue(dev);
5693

5694 5695 5696 5697 5698 5699 5700 5701 5702 5703 5704 5705
#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;
5706 5707
}

5708 5709
static const struct ethtool_ops default_ethtool_ops;

5710 5711 5712 5713 5714 5715 5716 5717
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
5718
/**
T
Tom Herbert 已提交
5719
 *	alloc_netdev_mqs - allocate network device
L
Linus Torvalds 已提交
5720 5721 5722
 *	@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
5723 5724
 *	@txqs:		the number of TX subqueues to allocate
 *	@rxqs:		the number of RX subqueues to allocate
L
Linus Torvalds 已提交
5725 5726
 *
 *	Allocates a struct net_device with private data area for driver use
5727
 *	and performs basic initialization.  Also allocates subquue structs
T
Tom Herbert 已提交
5728
 *	for each queue on the device.
L
Linus Torvalds 已提交
5729
 */
T
Tom Herbert 已提交
5730 5731 5732
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
5733 5734
{
	struct net_device *dev;
5735
	size_t alloc_size;
5736
	struct net_device *p;
L
Linus Torvalds 已提交
5737

5738 5739
	BUG_ON(strlen(name) >= sizeof(dev->name));

T
Tom Herbert 已提交
5740
	if (txqs < 1) {
5741
		pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
5742 5743 5744
		return NULL;
	}

T
Tom Herbert 已提交
5745 5746
#ifdef CONFIG_RPS
	if (rxqs < 1) {
5747
		pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
T
Tom Herbert 已提交
5748 5749 5750 5751
		return NULL;
	}
#endif

5752
	alloc_size = sizeof(struct net_device);
5753 5754
	if (sizeof_priv) {
		/* ensure 32-byte alignment of private area */
5755
		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
5756 5757 5758
		alloc_size += sizeof_priv;
	}
	/* ensure 32-byte alignment of whole construct */
5759
	alloc_size += NETDEV_ALIGN - 1;
L
Linus Torvalds 已提交
5760

5761
	p = kzalloc(alloc_size, GFP_KERNEL);
5762
	if (!p)
L
Linus Torvalds 已提交
5763 5764
		return NULL;

5765
	dev = PTR_ALIGN(p, NETDEV_ALIGN);
L
Linus Torvalds 已提交
5766
	dev->padded = (char *)dev - (char *)p;
5767

E
Eric Dumazet 已提交
5768 5769
	dev->pcpu_refcnt = alloc_percpu(int);
	if (!dev->pcpu_refcnt)
5770
		goto free_p;
5771 5772

	if (dev_addr_init(dev))
E
Eric Dumazet 已提交
5773
		goto free_pcpu;
5774

5775
	dev_mc_init(dev);
5776
	dev_uc_init(dev);
J
Jiri Pirko 已提交
5777

5778
	dev_net_set(dev, &init_net);
L
Linus Torvalds 已提交
5779

5780
	dev->gso_max_size = GSO_MAX_SIZE;
5781
	dev->gso_max_segs = GSO_MAX_SEGS;
5782 5783 5784 5785

	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
5786
	INIT_LIST_HEAD(&dev->upper_dev_list);
5787 5788 5789
	dev->priv_flags = IFF_XMIT_DST_RELEASE;
	setup(dev);

T
Tom Herbert 已提交
5790 5791
	dev->num_tx_queues = txqs;
	dev->real_num_tx_queues = txqs;
5792
	if (netif_alloc_netdev_queues(dev))
5793
		goto free_all;
5794

E
Eric Dumazet 已提交
5795
#ifdef CONFIG_RPS
T
Tom Herbert 已提交
5796 5797
	dev->num_rx_queues = rxqs;
	dev->real_num_rx_queues = rxqs;
T
Tom Herbert 已提交
5798
	if (netif_alloc_rx_queues(dev))
5799
		goto free_all;
E
Eric Dumazet 已提交
5800
#endif
T
Tom Herbert 已提交
5801

L
Linus Torvalds 已提交
5802
	strcpy(dev->name, name);
5803
	dev->group = INIT_NETDEV_GROUP;
5804 5805
	if (!dev->ethtool_ops)
		dev->ethtool_ops = &default_ethtool_ops;
L
Linus Torvalds 已提交
5806
	return dev;
5807

5808 5809 5810 5811
free_all:
	free_netdev(dev);
	return NULL;

E
Eric Dumazet 已提交
5812 5813
free_pcpu:
	free_percpu(dev->pcpu_refcnt);
5814
	kfree(dev->_tx);
T
Tom Herbert 已提交
5815 5816 5817 5818
#ifdef CONFIG_RPS
	kfree(dev->_rx);
#endif

5819 5820 5821
free_p:
	kfree(p);
	return NULL;
L
Linus Torvalds 已提交
5822
}
T
Tom Herbert 已提交
5823
EXPORT_SYMBOL(alloc_netdev_mqs);
L
Linus Torvalds 已提交
5824 5825 5826 5827 5828

/**
 *	free_netdev - free network device
 *	@dev: device
 *
5829 5830
 *	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
5831 5832 5833 5834
 *	If this is the last reference then it will be freed.
 */
void free_netdev(struct net_device *dev)
{
5835 5836
	struct napi_struct *p, *n;

5837 5838
	release_net(dev_net(dev));

5839
	kfree(dev->_tx);
T
Tom Herbert 已提交
5840 5841 5842
#ifdef CONFIG_RPS
	kfree(dev->_rx);
#endif
5843

5844
	kfree(rcu_dereference_protected(dev->ingress_queue, 1));
5845

5846 5847 5848
	/* Flush device addresses */
	dev_addr_flush(dev);

5849 5850 5851
	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
		netif_napi_del(p);

E
Eric Dumazet 已提交
5852 5853 5854
	free_percpu(dev->pcpu_refcnt);
	dev->pcpu_refcnt = NULL;

S
Stephen Hemminger 已提交
5855
	/*  Compatibility with error handling in drivers */
L
Linus Torvalds 已提交
5856 5857 5858 5859 5860 5861 5862 5863
	if (dev->reg_state == NETREG_UNINITIALIZED) {
		kfree((char *)dev - dev->padded);
		return;
	}

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

5864 5865
	/* will free via device release */
	put_device(&dev->dev);
L
Linus Torvalds 已提交
5866
}
E
Eric Dumazet 已提交
5867
EXPORT_SYMBOL(free_netdev);
5868

5869 5870 5871 5872 5873 5874
/**
 *	synchronize_net -  Synchronize with packet receive processing
 *
 *	Wait for packets currently being received to be done.
 *	Does not block later packets from starting.
 */
5875
void synchronize_net(void)
L
Linus Torvalds 已提交
5876 5877
{
	might_sleep();
5878 5879 5880 5881
	if (rtnl_is_locked())
		synchronize_rcu_expedited();
	else
		synchronize_rcu();
L
Linus Torvalds 已提交
5882
}
E
Eric Dumazet 已提交
5883
EXPORT_SYMBOL(synchronize_net);
L
Linus Torvalds 已提交
5884 5885

/**
5886
 *	unregister_netdevice_queue - remove device from the kernel
L
Linus Torvalds 已提交
5887
 *	@dev: device
5888
 *	@head: list
5889
 *
L
Linus Torvalds 已提交
5890
 *	This function shuts down a device interface and removes it
5891
 *	from the kernel tables.
5892
 *	If head not NULL, device is queued to be unregistered later.
L
Linus Torvalds 已提交
5893 5894 5895 5896 5897
 *
 *	Callers must hold the rtnl semaphore.  You may want
 *	unregister_netdev() instead of this.
 */

5898
void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
L
Linus Torvalds 已提交
5899
{
5900 5901
	ASSERT_RTNL();

5902
	if (head) {
5903
		list_move_tail(&dev->unreg_list, head);
5904 5905 5906 5907 5908
	} else {
		rollback_registered(dev);
		/* Finish processing unregister after unlock */
		net_set_todo(dev);
	}
L
Linus Torvalds 已提交
5909
}
5910
EXPORT_SYMBOL(unregister_netdevice_queue);
L
Linus Torvalds 已提交
5911

5912 5913 5914 5915 5916 5917 5918 5919 5920 5921 5922 5923 5924 5925
/**
 *	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);
	}
}
5926
EXPORT_SYMBOL(unregister_netdevice_many);
5927

L
Linus Torvalds 已提交
5928 5929 5930 5931 5932
/**
 *	unregister_netdev - remove device from the kernel
 *	@dev: device
 *
 *	This function shuts down a device interface and removes it
5933
 *	from the kernel tables.
L
Linus Torvalds 已提交
5934 5935 5936 5937 5938 5939 5940 5941 5942 5943 5944 5945 5946
 *
 *	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);

5947 5948 5949 5950 5951 5952 5953 5954 5955 5956 5957 5958 5959 5960 5961 5962 5963 5964 5965 5966 5967 5968 5969 5970 5971 5972 5973 5974 5975 5976 5977
/**
 *	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;
5978
	if (net_eq(dev_net(dev), net))
5979 5980 5981 5982 5983 5984
		goto out;

	/* Pick the destination device name, and ensure
	 * we can use it in the destination network namespace.
	 */
	err = -EEXIST;
5985
	if (__dev_get_by_name(net, dev->name)) {
5986 5987 5988
		/* We get here if we can't use the current device name */
		if (!pat)
			goto out;
5989
		if (dev_get_valid_name(net, dev, pat) < 0)
5990 5991 5992 5993 5994 5995 5996 5997
			goto out;
	}

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

	/* If device is running close it first. */
5998
	dev_close(dev);
5999 6000 6001 6002 6003 6004 6005 6006 6007 6008 6009 6010

	/* 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.
6011 6012 6013 6014

	   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.
6015 6016
	*/
	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
6017 6018
	rcu_barrier();
	call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
6019
	rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
6020 6021 6022 6023

	/*
	 *	Flush the unicast and multicast chains
	 */
6024
	dev_uc_flush(dev);
6025
	dev_mc_flush(dev);
6026

6027 6028 6029
	/* Send a netdev-removed uevent to the old namespace */
	kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);

6030
	/* Actually switch the network namespace */
6031
	dev_net_set(dev, net);
6032 6033 6034 6035 6036 6037 6038 6039 6040

	/* 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;
	}

6041 6042 6043
	/* Send a netdev-add uevent to the new namespace */
	kobject_uevent(&dev->dev.kobj, KOBJ_ADD);

6044
	/* Fixup kobjects */
6045
	err = device_rename(&dev->dev, dev->name);
6046
	WARN_ON(err);
6047 6048 6049 6050 6051 6052 6053

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

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

6054 6055 6056 6057 6058 6059
	/*
	 *	Prevent userspace races by waiting until the network
	 *	device is fully setup before sending notifications.
	 */
	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);

6060 6061 6062 6063 6064
	synchronize_net();
	err = 0;
out:
	return err;
}
6065
EXPORT_SYMBOL_GPL(dev_change_net_namespace);
6066

L
Linus Torvalds 已提交
6067 6068 6069 6070 6071 6072 6073 6074 6075
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;

6076
	if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
L
Linus Torvalds 已提交
6077 6078 6079 6080 6081 6082 6083 6084 6085 6086 6087 6088 6089 6090 6091 6092
		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. */
6093 6094 6095 6096 6097 6098
	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;
	}
6099 6100 6101 6102 6103
	/* 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
6104 6105 6106 6107 6108

	raise_softirq_irqoff(NET_TX_SOFTIRQ);
	local_irq_enable();

	/* Process offline CPU's input_pkt_queue */
6109
	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
L
Linus Torvalds 已提交
6110
		netif_rx(skb);
6111
		input_queue_head_incr(oldsd);
T
Tom Herbert 已提交
6112
	}
6113
	while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
6114
		netif_rx(skb);
6115 6116
		input_queue_head_incr(oldsd);
	}
L
Linus Torvalds 已提交
6117 6118 6119 6120 6121

	return NOTIFY_OK;
}


6122
/**
6123 6124 6125 6126
 *	netdev_increment_features - increment feature set by one
 *	@all: current feature set
 *	@one: new feature set
 *	@mask: mask feature set
6127 6128
 *
 *	Computes a new feature set after adding a device with feature set
6129 6130
 *	@one to the master device with current feature set @all.  Will not
 *	enable anything that is off in @mask. Returns the new feature set.
6131
 */
6132 6133
netdev_features_t netdev_increment_features(netdev_features_t all,
	netdev_features_t one, netdev_features_t mask)
6134
{
6135 6136 6137
	if (mask & NETIF_F_GEN_CSUM)
		mask |= NETIF_F_ALL_CSUM;
	mask |= NETIF_F_VLAN_CHALLENGED;
6138

6139 6140
	all |= one & (NETIF_F_ONE_FOR_ALL|NETIF_F_ALL_CSUM) & mask;
	all &= one | ~NETIF_F_ALL_FOR_ALL;
6141

6142 6143 6144
	/* If one device supports hw checksumming, set for all. */
	if (all & NETIF_F_GEN_CSUM)
		all &= ~(NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM);
6145 6146 6147

	return all;
}
6148
EXPORT_SYMBOL(netdev_increment_features);
6149

6150
static struct hlist_head * __net_init netdev_create_hash(void)
6151 6152 6153 6154 6155 6156 6157 6158 6159 6160 6161 6162
{
	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;
}

6163
/* Initialize per network namespace state */
6164
static int __net_init netdev_init(struct net *net)
6165
{
6166 6167
	if (net != &init_net)
		INIT_LIST_HEAD(&net->dev_base_head);
6168

6169 6170 6171
	net->dev_name_head = netdev_create_hash();
	if (net->dev_name_head == NULL)
		goto err_name;
6172

6173 6174 6175
	net->dev_index_head = netdev_create_hash();
	if (net->dev_index_head == NULL)
		goto err_idx;
6176 6177

	return 0;
6178 6179 6180 6181 6182

err_idx:
	kfree(net->dev_name_head);
err_name:
	return -ENOMEM;
6183 6184
}

6185 6186 6187 6188 6189 6190
/**
 *	netdev_drivername - network driver for the device
 *	@dev: network device
 *
 *	Determine network driver for device.
 */
6191
const char *netdev_drivername(const struct net_device *dev)
6192
{
6193 6194
	const struct device_driver *driver;
	const struct device *parent;
6195
	const char *empty = "";
6196 6197 6198

	parent = dev->dev.parent;
	if (!parent)
6199
		return empty;
6200 6201 6202

	driver = parent->driver;
	if (driver && driver->name)
6203 6204
		return driver->name;
	return empty;
6205 6206
}

6207
static int __netdev_printk(const char *level, const struct net_device *dev,
6208 6209 6210 6211
			   struct va_format *vaf)
{
	int r;

6212
	if (dev && dev->dev.parent) {
6213 6214 6215 6216 6217 6218
		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);
6219
	} else if (dev) {
6220
		r = printk("%s%s: %pV", level, netdev_name(dev), vaf);
6221
	} else {
6222
		r = printk("%s(NULL net_device): %pV", level, vaf);
6223
	}
6224 6225 6226 6227 6228 6229 6230 6231 6232 6233 6234 6235 6236 6237 6238 6239 6240

	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);
6241

6242 6243 6244 6245 6246 6247 6248 6249 6250 6251 6252 6253 6254 6255 6256 6257 6258 6259 6260
	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);			\
6261
								\
6262 6263 6264 6265 6266 6267 6268 6269 6270 6271 6272 6273 6274 6275
	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);

6276
static void __net_exit netdev_exit(struct net *net)
6277 6278 6279 6280 6281
{
	kfree(net->dev_name_head);
	kfree(net->dev_index_head);
}

6282
static struct pernet_operations __net_initdata netdev_net_ops = {
6283 6284 6285 6286
	.init = netdev_init,
	.exit = netdev_exit,
};

6287
static void __net_exit default_device_exit(struct net *net)
6288
{
6289
	struct net_device *dev, *aux;
6290
	/*
6291
	 * Push all migratable network devices back to the
6292 6293 6294
	 * initial network namespace
	 */
	rtnl_lock();
6295
	for_each_netdev_safe(net, dev, aux) {
6296
		int err;
6297
		char fb_name[IFNAMSIZ];
6298 6299 6300 6301 6302

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

6303 6304 6305
		/* Leave virtual devices for the generic cleanup */
		if (dev->rtnl_link_ops)
			continue;
6306

L
Lucas De Marchi 已提交
6307
		/* Push remaining network devices to init_net */
6308 6309
		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
		err = dev_change_net_namespace(dev, &init_net, fb_name);
6310
		if (err) {
6311 6312
			pr_emerg("%s: failed to move %s to init_net: %d\n",
				 __func__, dev->name, err);
6313
			BUG();
6314 6315 6316 6317 6318
		}
	}
	rtnl_unlock();
}

6319 6320 6321
static void __net_exit default_device_exit_batch(struct list_head *net_list)
{
	/* At exit all network devices most be removed from a network
6322
	 * namespace.  Do this in the reverse order of registration.
6323 6324 6325 6326 6327 6328 6329 6330 6331 6332 6333 6334 6335 6336 6337 6338 6339
	 * 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
6340
	list_del(&dev_kill_list);
6341 6342 6343
	rtnl_unlock();
}

6344
static struct pernet_operations __net_initdata default_device_ops = {
6345
	.exit = default_device_exit,
6346
	.exit_batch = default_device_exit_batch,
6347 6348
};

L
Linus Torvalds 已提交
6349 6350 6351 6352 6353 6354 6355 6356 6357 6358 6359 6360 6361 6362 6363 6364 6365 6366 6367 6368
/*
 *	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;

6369
	if (netdev_kobject_init())
L
Linus Torvalds 已提交
6370 6371 6372
		goto out;

	INIT_LIST_HEAD(&ptype_all);
6373
	for (i = 0; i < PTYPE_HASH_SIZE; i++)
L
Linus Torvalds 已提交
6374 6375
		INIT_LIST_HEAD(&ptype_base[i]);

6376 6377
	INIT_LIST_HEAD(&offload_base);

6378 6379
	if (register_pernet_subsys(&netdev_net_ops))
		goto out;
L
Linus Torvalds 已提交
6380 6381 6382 6383 6384

	/*
	 *	Initialise the packet receive queues.
	 */

6385
	for_each_possible_cpu(i) {
E
Eric Dumazet 已提交
6386
		struct softnet_data *sd = &per_cpu(softnet_data, i);
L
Linus Torvalds 已提交
6387

C
Changli Gao 已提交
6388
		memset(sd, 0, sizeof(*sd));
E
Eric Dumazet 已提交
6389
		skb_queue_head_init(&sd->input_pkt_queue);
6390
		skb_queue_head_init(&sd->process_queue);
E
Eric Dumazet 已提交
6391 6392
		sd->completion_queue = NULL;
		INIT_LIST_HEAD(&sd->poll_list);
6393 6394
		sd->output_queue = NULL;
		sd->output_queue_tailp = &sd->output_queue;
E
Eric Dumazet 已提交
6395
#ifdef CONFIG_RPS
E
Eric Dumazet 已提交
6396 6397 6398 6399
		sd->csd.func = rps_trigger_softirq;
		sd->csd.info = sd;
		sd->csd.flags = 0;
		sd->cpu = i;
6400
#endif
T
Tom Herbert 已提交
6401

E
Eric Dumazet 已提交
6402 6403 6404 6405
		sd->backlog.poll = process_backlog;
		sd->backlog.weight = weight_p;
		sd->backlog.gro_list = NULL;
		sd->backlog.gro_count = 0;
6406 6407 6408 6409

#ifdef CONFIG_NET_FLOW_LIMIT
		sd->flow_limit = NULL;
#endif
L
Linus Torvalds 已提交
6410 6411 6412 6413
	}

	dev_boot_phase = 0;

6414 6415 6416 6417 6418 6419 6420 6421 6422 6423 6424 6425 6426 6427 6428
	/* 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;

6429 6430
	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
L
Linus Torvalds 已提交
6431 6432 6433 6434 6435 6436 6437 6438 6439

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

subsys_initcall(net_dev_init);