dev.c 88.3 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 <asm/system.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>
#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>
#include <linux/notifier.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <linux/rtnetlink.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/stat.h>
#include <linux/if_bridge.h>
#include <net/dst.h>
#include <net/pkt_sched.h>
#include <net/checksum.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/netpoll.h>
#include <linux/rcupdate.h>
#include <linux/delay.h>
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#include <linux/wireless.h>
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#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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/*
 *	The list of packet types we will receive (as opposed to discard)
 *	and the routines to invoke.
 *
 *	Why 16. Because with 16 the only overlap we get on a hash of the
 *	low nibble of the protocol value is RARP/SNAP/X.25.
 *
 *      NOTE:  That is no longer true with the addition of VLAN tags.  Not
 *             sure which should go first, but I bet it won't make much
 *             difference if we are running VLANs.  The good news is that
 *             this protocol won't be in the list unless compiled in, so
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 *             the average user (w/out VLANs) will not be adversely affected.
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 *             --BLG
 *
 *		0800	IP
 *		8100    802.1Q VLAN
 *		0001	802.3
 *		0002	AX.25
 *		0004	802.2
 *		8035	RARP
 *		0005	SNAP
 *		0805	X.25
 *		0806	ARP
 *		8137	IPX
 *		0009	Localtalk
 *		86DD	IPv6
 */

static DEFINE_SPINLOCK(ptype_lock);
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static struct list_head ptype_base[16] __read_mostly;	/* 16 way hashed list */
static struct list_head ptype_all __read_mostly;	/* Taps */
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#ifdef CONFIG_NET_DMA
static struct dma_client *net_dma_client;
static unsigned int net_dma_count;
static spinlock_t net_dma_event_lock;
#endif

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/*
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 * The @dev_base list is protected by @dev_base_lock and the rtnl
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 * semaphore.
 *
 * Pure readers hold dev_base_lock for reading.
 *
 * Writers must hold the rtnl semaphore while they loop through the
 * dev_base list, and hold dev_base_lock for writing when they do the
 * 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.
 */
struct net_device *dev_base;
static struct net_device **dev_tail = &dev_base;
DEFINE_RWLOCK(dev_base_lock);

EXPORT_SYMBOL(dev_base);
EXPORT_SYMBOL(dev_base_lock);

#define NETDEV_HASHBITS	8
static struct hlist_head dev_name_head[1<<NETDEV_HASHBITS];
static struct hlist_head dev_index_head[1<<NETDEV_HASHBITS];

static inline struct hlist_head *dev_name_hash(const char *name)
{
	unsigned hash = full_name_hash(name, strnlen(name, IFNAMSIZ));
	return &dev_name_head[hash & ((1<<NETDEV_HASHBITS)-1)];
}

static inline struct hlist_head *dev_index_hash(int ifindex)
{
	return &dev_index_head[ifindex & ((1<<NETDEV_HASHBITS)-1)];
}

/*
 *	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(struct softnet_data, softnet_data) = { NULL };
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#ifdef CONFIG_SYSFS
extern int netdev_sysfs_init(void);
extern int netdev_register_sysfs(struct net_device *);
extern void netdev_unregister_sysfs(struct net_device *);
#else
#define netdev_sysfs_init()	 	(0)
#define netdev_register_sysfs(dev)	(0)
#define	netdev_unregister_sysfs(dev)	do { } while(0)
#endif


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

		Protocol management and registration routines

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

/*
 *	For efficiency
 */

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static int netdev_nit;
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/*
 *	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)
 */

/**
 *	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)
{
	int hash;

	spin_lock_bh(&ptype_lock);
	if (pt->type == htons(ETH_P_ALL)) {
		netdev_nit++;
		list_add_rcu(&pt->list, &ptype_all);
	} else {
		hash = ntohs(pt->type) & 15;
		list_add_rcu(&pt->list, &ptype_base[hash]);
	}
	spin_unlock_bh(&ptype_lock);
}

/**
 *	__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)
{
	struct list_head *head;
	struct packet_type *pt1;

	spin_lock_bh(&ptype_lock);

	if (pt->type == htons(ETH_P_ALL)) {
		netdev_nit--;
		head = &ptype_all;
	} else
		head = &ptype_base[ntohs(pt->type) & 15];

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

	printk(KERN_WARNING "dev_remove_pack: %p not found.\n", pt);
out:
	spin_unlock_bh(&ptype_lock);
}
/**
 *	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();
}

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

		      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));
			strcpy(s[i].name, name);
			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] != ' ' &&
		    !strncmp(dev->name, s[i].name, strlen(s[i].name))) {
			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;
}


/**
 *	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
	 */
	if (__dev_get_by_name(name))
		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
 *	@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.
 */

struct net_device *__dev_get_by_name(const char *name)
{
	struct hlist_node *p;

	hlist_for_each(p, dev_name_hash(name)) {
		struct net_device *dev
			= hlist_entry(p, struct net_device, name_hlist);
		if (!strncmp(dev->name, name, IFNAMSIZ))
			return dev;
	}
	return NULL;
}

/**
 *	dev_get_by_name		- find a device by its name
 *	@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.
 */

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

	read_lock(&dev_base_lock);
	dev = __dev_get_by_name(name);
	if (dev)
		dev_hold(dev);
	read_unlock(&dev_base_lock);
	return dev;
}

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

struct net_device *__dev_get_by_index(int ifindex)
{
	struct hlist_node *p;

	hlist_for_each(p, dev_index_hash(ifindex)) {
		struct net_device *dev
			= hlist_entry(p, struct net_device, index_hlist);
		if (dev->ifindex == ifindex)
			return dev;
	}
	return NULL;
}


/**
 *	dev_get_by_index - find a device by its ifindex
 *	@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.
 */

struct net_device *dev_get_by_index(int ifindex)
{
	struct net_device *dev;

	read_lock(&dev_base_lock);
	dev = __dev_get_by_index(ifindex);
	if (dev)
		dev_hold(dev);
	read_unlock(&dev_base_lock);
	return dev;
}

/**
 *	dev_getbyhwaddr - find a device by its hardware address
 *	@type: media type of device
 *	@ha: hardware address
 *
 *	Search for an interface by MAC address. Returns NULL if the device
 *	is not found or a pointer to the device. The caller must hold the
 *	rtnl semaphore. The returned device has not had its ref count increased
 *	and the caller must therefore be careful about locking
 *
 *	BUGS:
 *	If the API was consistent this would be __dev_get_by_hwaddr
 */

struct net_device *dev_getbyhwaddr(unsigned short type, char *ha)
{
	struct net_device *dev;

	ASSERT_RTNL();

	for (dev = dev_base; dev; dev = dev->next)
		if (dev->type == type &&
		    !memcmp(dev->dev_addr, ha, dev->addr_len))
			break;
	return dev;
}

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EXPORT_SYMBOL(dev_getbyhwaddr);

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struct net_device *dev_getfirstbyhwtype(unsigned short type)
{
	struct net_device *dev;

	rtnl_lock();
	for (dev = dev_base; dev; dev = dev->next) {
		if (dev->type == type) {
			dev_hold(dev);
			break;
		}
	}
	rtnl_unlock();
	return dev;
}

EXPORT_SYMBOL(dev_getfirstbyhwtype);

/**
 *	dev_get_by_flags - find any device with given flags
 *	@if_flags: IFF_* values
 *	@mask: bitmask of bits in if_flags to check
 *
 *	Search for any interface with the given flags. Returns NULL if a device
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 *	is not found or a pointer to the device. The device returned has
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 *	had a reference added and the pointer is safe until the user calls
 *	dev_put to indicate they have finished with it.
 */

struct net_device * dev_get_by_flags(unsigned short if_flags, unsigned short mask)
{
	struct net_device *dev;

	read_lock(&dev_base_lock);
	for (dev = dev_base; dev != NULL; dev = dev->next) {
		if (((dev->flags ^ if_flags) & mask) == 0) {
			dev_hold(dev);
			break;
		}
	}
	read_unlock(&dev_base_lock);
	return dev;
}

/**
 *	dev_valid_name - check if name is okay for network device
 *	@name: name string
 *
 *	Network device names need to be valid file names to
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 *	to allow sysfs to work.  We also disallow any kind of
 *	whitespace.
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 */
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int dev_valid_name(const char *name)
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{
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	if (*name == '\0')
		return 0;
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	if (strlen(name) >= IFNAMSIZ)
		return 0;
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	if (!strcmp(name, ".") || !strcmp(name, ".."))
		return 0;

	while (*name) {
		if (*name == '/' || isspace(*name))
			return 0;
		name++;
	}
	return 1;
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}

/**
 *	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
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 *	id. It scans list of devices to build up a free map, then chooses
 *	the first empty slot. The caller must hold the dev_base or rtnl lock
 *	while allocating the name and adding the device in order to avoid
 *	duplicates.
 *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
 *	Returns the number of the unit assigned or a negative errno code.
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 */

int dev_alloc_name(struct net_device *dev, const char *name)
{
	int i = 0;
	char buf[IFNAMSIZ];
	const char *p;
	const int max_netdevices = 8*PAGE_SIZE;
	long *inuse;
	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 */
		inuse = (long *) get_zeroed_page(GFP_ATOMIC);
		if (!inuse)
			return -ENOMEM;

		for (d = dev_base; d; d = d->next) {
			if (!sscanf(d->name, name, &i))
				continue;
			if (i < 0 || i >= max_netdevices)
				continue;

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

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

	snprintf(buf, sizeof(buf), name, i);
	if (!__dev_get_by_name(buf)) {
		strlcpy(dev->name, buf, IFNAMSIZ);
		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;
}


/**
 *	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.
 */
int dev_change_name(struct net_device *dev, char *newname)
{
	int err = 0;

	ASSERT_RTNL();

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

	if (!dev_valid_name(newname))
		return -EINVAL;

	if (strchr(newname, '%')) {
		err = dev_alloc_name(dev, newname);
		if (err < 0)
			return err;
		strcpy(newname, dev->name);
	}
	else if (__dev_get_by_name(newname))
		return -EEXIST;
	else
		strlcpy(dev->name, newname, IFNAMSIZ);

754 755 756 757
	device_rename(&dev->dev, dev->name);
	hlist_del(&dev->name_hlist);
	hlist_add_head(&dev->name_hlist, dev_name_hash(dev->name));
	raw_notifier_call_chain(&netdev_chain, NETDEV_CHANGENAME, dev);
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	return err;
}

762
/**
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 *	netdev_features_change - device changes features
764 765 766 767 768 769
 *	@dev: device to cause notification
 *
 *	Called to indicate a device has changed features.
 */
void netdev_features_change(struct net_device *dev)
{
770
	raw_notifier_call_chain(&netdev_chain, NETDEV_FEAT_CHANGE, dev);
771 772 773
}
EXPORT_SYMBOL(netdev_features_change);

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/**
 *	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) {
785
		raw_notifier_call_chain(&netdev_chain,
786
				NETDEV_CHANGE, dev);
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		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
	}
}

/**
 *	dev_load 	- load a network module
 *	@name: name of interface
 *
 *	If a network interface is not present and the process has suitable
 *	privileges this function loads the module. If module loading is not
 *	available in this kernel then it becomes a nop.
 */

void dev_load(const char *name)
{
802
	struct net_device *dev;
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	read_lock(&dev_base_lock);
	dev = __dev_get_by_name(name);
	read_unlock(&dev_base_lock);

	if (!dev && capable(CAP_SYS_MODULE))
		request_module("%s", name);
}

static int default_rebuild_header(struct sk_buff *skb)
{
	printk(KERN_DEBUG "%s: default_rebuild_header called -- BUG!\n",
	       skb->dev ? skb->dev->name : "NULL!!!");
	kfree_skb(skb);
	return 1;
}


/**
 *	dev_open	- prepare an interface for use.
 *	@dev:	device to open
 *
 *	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.
 */
int dev_open(struct net_device *dev)
{
	int ret = 0;

	/*
	 *	Is it already up?
	 */

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

	/*
	 *	Is it even present?
	 */
	if (!netif_device_present(dev))
		return -ENODEV;

	/*
	 *	Call device private open method
	 */
	set_bit(__LINK_STATE_START, &dev->state);
	if (dev->open) {
		ret = dev->open(dev);
		if (ret)
			clear_bit(__LINK_STATE_START, &dev->state);
	}

860
	/*
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	 *	If it went open OK then:
	 */

	if (!ret) {
		/*
		 *	Set the flags.
		 */
		dev->flags |= IFF_UP;

		/*
		 *	Initialize multicasting status
		 */
		dev_mc_upload(dev);

		/*
		 *	Wakeup transmit queue engine
		 */
		dev_activate(dev);

		/*
		 *	... and announce new interface.
		 */
883
		raw_notifier_call_chain(&netdev_chain, NETDEV_UP, dev);
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	}
	return ret;
}

/**
 *	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)
{
	if (!(dev->flags & IFF_UP))
		return 0;

	/*
	 *	Tell people we are going down, so that they can
	 *	prepare to death, when device is still operating.
	 */
906
	raw_notifier_call_chain(&netdev_chain, NETDEV_GOING_DOWN, dev);
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	dev_deactivate(dev);

	clear_bit(__LINK_STATE_START, &dev->state);

	/* Synchronize to scheduled poll. We cannot touch poll list,
	 * it can be even on different cpu. So just clear netif_running(),
	 * and wait when poll really will happen. Actually, the best place
	 * for this is inside dev->stop() after device stopped its irq
	 * engine, but this requires more changes in devices. */

	smp_mb__after_clear_bit(); /* Commit netif_running(). */
	while (test_bit(__LINK_STATE_RX_SCHED, &dev->state)) {
		/* No hurry. */
921
		msleep(1);
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	}

	/*
	 *	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 (dev->stop)
		dev->stop(dev);

	/*
	 *	Device is now down.
	 */

	dev->flags &= ~IFF_UP;

	/*
	 * Tell people we are down
	 */
943
	raw_notifier_call_chain(&netdev_chain, NETDEV_DOWN, dev);
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	return 0;
}


/*
 *	Device change register/unregister. These are not inline or static
 *	as we export them to the world.
 */

/**
 *	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
964
 *	to the new notifier to allow device to have a race free
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 *	view of the network device list.
 */

int register_netdevice_notifier(struct notifier_block *nb)
{
	struct net_device *dev;
	int err;

	rtnl_lock();
974
	err = raw_notifier_chain_register(&netdev_chain, nb);
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	if (!err) {
		for (dev = dev_base; dev; dev = dev->next) {
			nb->notifier_call(nb, NETDEV_REGISTER, dev);

979
			if (dev->flags & IFF_UP)
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				nb->notifier_call(nb, NETDEV_UP, dev);
		}
	}
	rtnl_unlock();
	return err;
}

/**
 *	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.
 */

int unregister_netdevice_notifier(struct notifier_block *nb)
{
999 1000 1001
	int err;

	rtnl_lock();
1002
	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1003 1004
	rtnl_unlock();
	return err;
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}

/**
 *	call_netdevice_notifiers - call all network notifier blocks
 *      @val: value passed unmodified to notifier function
 *      @v:   pointer passed unmodified to notifier function
 *
 *	Call all network notifier blocks.  Parameters and return value
1013
 *	are as for raw_notifier_call_chain().
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 */

int call_netdevice_notifiers(unsigned long val, void *v)
{
1018
	return raw_notifier_call_chain(&netdev_chain, val, v);
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}

/* When > 0 there are consumers of rx skb time stamps */
static atomic_t netstamp_needed = ATOMIC_INIT(0);

void net_enable_timestamp(void)
{
	atomic_inc(&netstamp_needed);
}

void net_disable_timestamp(void)
{
	atomic_dec(&netstamp_needed);
}

1034
static inline void net_timestamp(struct sk_buff *skb)
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{
	if (atomic_read(&netstamp_needed))
1037
		__net_timestamp(skb);
1038 1039
	else
		skb->tstamp.tv64 = 0;
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}

/*
 *	Support routine. Sends outgoing frames to any network
 *	taps currently in use.
 */

1047
static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
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{
	struct packet_type *ptype;
1050 1051

	net_timestamp(skb);
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	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) &&
		    (ptype->af_packet_priv == NULL ||
		     (struct sock *)ptype->af_packet_priv != skb->sk)) {
			struct sk_buff *skb2= skb_clone(skb, GFP_ATOMIC);
			if (!skb2)
				break;

			/* skb->nh should be correctly
			   set by sender, so that the second statement is
			   just protection against buggy protocols.
			 */
1069
			skb_reset_mac_header(skb2);
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1071 1072
			if (skb_network_header(skb2) < skb2->data ||
			    skb_network_header(skb2) > skb2->tail) {
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				if (net_ratelimit())
					printk(KERN_CRIT "protocol %04x is "
					       "buggy, dev %s\n",
					       skb2->protocol, dev->name);
1077
				skb_reset_network_header(skb2);
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			}

			skb2->h.raw = skb2->nh.raw;
			skb2->pkt_type = PACKET_OUTGOING;
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			ptype->func(skb2, skb->dev, ptype, skb->dev);
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		}
	}
	rcu_read_unlock();
}

1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145

void __netif_schedule(struct net_device *dev)
{
	if (!test_and_set_bit(__LINK_STATE_SCHED, &dev->state)) {
		unsigned long flags;
		struct softnet_data *sd;

		local_irq_save(flags);
		sd = &__get_cpu_var(softnet_data);
		dev->next_sched = sd->output_queue;
		sd->output_queue = dev;
		raise_softirq_irqoff(NET_TX_SOFTIRQ);
		local_irq_restore(flags);
	}
}
EXPORT_SYMBOL(__netif_schedule);

void __netif_rx_schedule(struct net_device *dev)
{
	unsigned long flags;

	local_irq_save(flags);
	dev_hold(dev);
	list_add_tail(&dev->poll_list, &__get_cpu_var(softnet_data).poll_list);
	if (dev->quota < 0)
		dev->quota += dev->weight;
	else
		dev->quota = dev->weight;
	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
	local_irq_restore(flags);
}
EXPORT_SYMBOL(__netif_rx_schedule);

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);


/* Hot-plugging. */
void netif_device_detach(struct net_device *dev)
{
	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
	    netif_running(dev)) {
		netif_stop_queue(dev);
	}
}
EXPORT_SYMBOL(netif_device_detach);

void netif_device_attach(struct net_device *dev)
{
	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
	    netif_running(dev)) {
		netif_wake_queue(dev);
1146
		__netdev_watchdog_up(dev);
1147 1148 1149 1150 1151
	}
}
EXPORT_SYMBOL(netif_device_attach);


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/*
 * Invalidate hardware checksum when packet is to be mangled, and
 * complete checksum manually on outgoing path.
 */
1156
int skb_checksum_help(struct sk_buff *skb)
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1157
{
1158
	__wsum csum;
1159
	int ret = 0, offset = skb_transport_offset(skb);
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1161
	if (skb->ip_summed == CHECKSUM_COMPLETE)
1162 1163 1164 1165 1166
		goto out_set_summed;

	if (unlikely(skb_shinfo(skb)->gso_size)) {
		/* Let GSO fix up the checksum. */
		goto out_set_summed;
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	}

	if (skb_cloned(skb)) {
		ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
		if (ret)
			goto out;
	}

1175
	BUG_ON(offset > (int)skb->len);
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	csum = skb_checksum(skb, offset, skb->len-offset, 0);

1178
	offset = skb->tail - skb_transport_header(skb);
1179
	BUG_ON(offset <= 0);
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1180
	BUG_ON(skb->csum_offset + 2 > offset);
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1182 1183
	*(__sum16 *)(skb_transport_header(skb) +
		     skb->csum_offset) = csum_fold(csum);
1184
out_set_summed:
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1185
	skb->ip_summed = CHECKSUM_NONE;
1186
out:
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	return ret;
}

1190 1191 1192
/**
 *	skb_gso_segment - Perform segmentation on skb.
 *	@skb: buffer to segment
1193
 *	@features: features for the output path (see dev->features)
1194 1195
 *
 *	This function segments the given skb and returns a list of segments.
1196 1197 1198
 *
 *	It may return NULL if the skb requires no segmentation.  This is
 *	only possible when GSO is used for verifying header integrity.
1199
 */
1200
struct sk_buff *skb_gso_segment(struct sk_buff *skb, int features)
1201 1202 1203
{
	struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
	struct packet_type *ptype;
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Al Viro 已提交
1204
	__be16 type = skb->protocol;
1205
	int err;
1206 1207 1208

	BUG_ON(skb_shinfo(skb)->frag_list);

1209
	skb_reset_mac_header(skb);
1210
	skb->mac_len = skb->nh.raw - skb->mac.raw;
1211 1212
	__skb_pull(skb, skb->mac_len);

1213
	if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
1214 1215 1216 1217 1218
		if (skb_header_cloned(skb) &&
		    (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
			return ERR_PTR(err);
	}

1219 1220 1221
	rcu_read_lock();
	list_for_each_entry_rcu(ptype, &ptype_base[ntohs(type) & 15], list) {
		if (ptype->type == type && !ptype->dev && ptype->gso_segment) {
1222
			if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
1223 1224 1225 1226
				err = ptype->gso_send_check(skb);
				segs = ERR_PTR(err);
				if (err || skb_gso_ok(skb, features))
					break;
1227 1228
				__skb_push(skb, (skb->data -
						 skb_network_header(skb)));
1229
			}
1230
			segs = ptype->gso_segment(skb, features);
1231 1232 1233 1234 1235
			break;
		}
	}
	rcu_read_unlock();

1236
	__skb_push(skb, skb->data - skb_mac_header(skb));
1237

1238 1239 1240 1241 1242
	return segs;
}

EXPORT_SYMBOL(skb_gso_segment);

1243 1244 1245 1246 1247
/* Take action when hardware reception checksum errors are detected. */
#ifdef CONFIG_BUG
void netdev_rx_csum_fault(struct net_device *dev)
{
	if (net_ratelimit()) {
1248
		printk(KERN_ERR "%s: hw csum failure.\n",
1249
			dev ? dev->name : "<unknown>");
1250 1251 1252 1253 1254 1255
		dump_stack();
	}
}
EXPORT_SYMBOL(netdev_rx_csum_fault);
#endif

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/* 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.
 */

static inline int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
{
1263
#ifdef CONFIG_HIGHMEM
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	int i;

	if (dev->features & NETIF_F_HIGHDMA)
		return 0;

	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
		if (PageHighMem(skb_shinfo(skb)->frags[i].page))
			return 1;

1273
#endif
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	return 0;
}

1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310
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
 *
 *	This function segments the given skb and stores the list of segments
 *	in skb->next.
 */
static int dev_gso_segment(struct sk_buff *skb)
{
	struct net_device *dev = skb->dev;
	struct sk_buff *segs;
1311 1312 1313 1314 1315 1316 1317 1318
	int features = dev->features & ~(illegal_highdma(dev, skb) ?
					 NETIF_F_SG : 0);

	segs = skb_gso_segment(skb, features);

	/* Verifying header integrity only. */
	if (!segs)
		return 0;
1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335

	if (unlikely(IS_ERR(segs)))
		return PTR_ERR(segs);

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

	return 0;
}

int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	if (likely(!skb->next)) {
		if (netdev_nit)
			dev_queue_xmit_nit(skb, dev);

1336 1337 1338 1339 1340 1341
		if (netif_needs_gso(dev, skb)) {
			if (unlikely(dev_gso_segment(skb)))
				goto out_kfree_skb;
			if (skb->next)
				goto gso;
		}
1342

1343
		return dev->hard_start_xmit(skb, dev);
1344 1345
	}

1346
gso:
1347 1348 1349 1350 1351 1352 1353 1354
	do {
		struct sk_buff *nskb = skb->next;
		int rc;

		skb->next = nskb->next;
		nskb->next = NULL;
		rc = dev->hard_start_xmit(nskb, dev);
		if (unlikely(rc)) {
1355
			nskb->next = skb->next;
1356 1357 1358
			skb->next = nskb;
			return rc;
		}
1359 1360
		if (unlikely(netif_queue_stopped(dev) && skb->next))
			return NETDEV_TX_BUSY;
1361
	} while (skb->next);
1362

1363 1364 1365 1366 1367 1368 1369
	skb->destructor = DEV_GSO_CB(skb)->destructor;

out_kfree_skb:
	kfree_skb(skb);
	return 0;
}

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#define HARD_TX_LOCK(dev, cpu) {			\
	if ((dev->features & NETIF_F_LLTX) == 0) {	\
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		netif_tx_lock(dev);			\
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	}						\
}

#define HARD_TX_UNLOCK(dev) {				\
	if ((dev->features & NETIF_F_LLTX) == 0) {	\
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		netif_tx_unlock(dev);			\
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	}						\
}

/**
 *	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.
1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405
 *
 * -----------------------------------------------------------------------------------
 *      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
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 */

int dev_queue_xmit(struct sk_buff *skb)
{
	struct net_device *dev = skb->dev;
	struct Qdisc *q;
	int rc = -ENOMEM;

1414 1415 1416 1417
	/* GSO will handle the following emulations directly. */
	if (netif_needs_gso(dev, skb))
		goto gso;

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	if (skb_shinfo(skb)->frag_list &&
	    !(dev->features & NETIF_F_FRAGLIST) &&
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	    __skb_linearize(skb))
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		goto out_kfree_skb;

	/* Fragmented skb is linearized if device does not support SG,
	 * or if at least one of fragments is in highmem and device
	 * does not support DMA from it.
	 */
	if (skb_shinfo(skb)->nr_frags &&
	    (!(dev->features & NETIF_F_SG) || illegal_highdma(dev, skb)) &&
H
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	    __skb_linearize(skb))
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1430 1431 1432 1433 1434
		goto out_kfree_skb;

	/* If packet is not checksummed and device does not support
	 * checksumming for this protocol, complete checksumming here.
	 */
1435
	if (skb->ip_summed == CHECKSUM_PARTIAL &&
1436
	    (!(dev->features & NETIF_F_GEN_CSUM) &&
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	     (!(dev->features & NETIF_F_IP_CSUM) ||
	      skb->protocol != htons(ETH_P_IP))))
1439 1440
		if (skb_checksum_help(skb))
			goto out_kfree_skb;
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1442
gso:
1443 1444
	spin_lock_prefetch(&dev->queue_lock);

1445 1446
	/* Disable soft irqs for various locks below. Also
	 * stops preemption for RCU.
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	 */
1448
	rcu_read_lock_bh();
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1450 1451 1452
	/* Updates of qdisc are serialized by queue_lock.
	 * The struct Qdisc which is pointed to by qdisc is now a
	 * rcu structure - it may be accessed without acquiring
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	 * a lock (but the structure may be stale.) The freeing of the
1454
	 * qdisc will be deferred until it's known that there are no
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	 * more references to it.
1456 1457
	 *
	 * If the qdisc has an enqueue function, we still need to
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	 * hold the queue_lock before calling it, since queue_lock
	 * also serializes access to the device queue.
	 */

	q = rcu_dereference(dev->qdisc);
#ifdef CONFIG_NET_CLS_ACT
	skb->tc_verd = SET_TC_AT(skb->tc_verd,AT_EGRESS);
#endif
	if (q->enqueue) {
		/* Grab device queue */
		spin_lock(&dev->queue_lock);
1469 1470 1471 1472 1473
		q = dev->qdisc;
		if (q->enqueue) {
			rc = q->enqueue(skb, q);
			qdisc_run(dev);
			spin_unlock(&dev->queue_lock);
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1475 1476 1477
			rc = rc == NET_XMIT_BYPASS ? NET_XMIT_SUCCESS : rc;
			goto out;
		}
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		spin_unlock(&dev->queue_lock);
	}

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

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	   Really, it is unlikely that netif_tx_lock protection is necessary
	   here.  (f.e. loopback and IP tunnels are clean ignoring statistics
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	   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 */

		if (dev->xmit_lock_owner != cpu) {

			HARD_TX_LOCK(dev, cpu);

			if (!netif_queue_stopped(dev)) {
				rc = 0;
1502
				if (!dev_hard_start_xmit(skb, dev)) {
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					HARD_TX_UNLOCK(dev);
					goto out;
				}
			}
			HARD_TX_UNLOCK(dev);
			if (net_ratelimit())
				printk(KERN_CRIT "Virtual device %s asks to "
				       "queue packet!\n", dev->name);
		} else {
			/* Recursion is detected! It is possible,
			 * unfortunately */
			if (net_ratelimit())
				printk(KERN_CRIT "Dead loop on virtual device "
				       "%s, fix it urgently!\n", dev->name);
		}
	}

	rc = -ENETDOWN;
1521
	rcu_read_unlock_bh();
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out_kfree_skb:
	kfree_skb(skb);
	return rc;
out:
1527
	rcu_read_unlock_bh();
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	return rc;
}


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

1536 1537 1538
int netdev_max_backlog __read_mostly = 1000;
int netdev_budget __read_mostly = 300;
int weight_p __read_mostly = 64;            /* old backlog weight */
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DEFINE_PER_CPU(struct netif_rx_stats, netdev_rx_stat) = { 0, };


/**
 *	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_CN_LOW   (low congestion)
 *	NET_RX_CN_MOD   (moderate congestion)
 *	NET_RX_CN_HIGH  (high congestion)
 *	NET_RX_DROP     (packet was dropped)
 *
 */

int netif_rx(struct sk_buff *skb)
{
	struct softnet_data *queue;
	unsigned long flags;

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

1570
	if (!skb->tstamp.tv64)
1571
		net_timestamp(skb);
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	/*
	 * The code is rearranged so that the path is the most
	 * short when CPU is congested, but is still operating.
	 */
	local_irq_save(flags);
	queue = &__get_cpu_var(softnet_data);

	__get_cpu_var(netdev_rx_stat).total++;
	if (queue->input_pkt_queue.qlen <= netdev_max_backlog) {
		if (queue->input_pkt_queue.qlen) {
enqueue:
			dev_hold(skb->dev);
			__skb_queue_tail(&queue->input_pkt_queue, skb);
			local_irq_restore(flags);
1587
			return NET_RX_SUCCESS;
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		}

		netif_rx_schedule(&queue->backlog_dev);
		goto enqueue;
	}

	__get_cpu_var(netdev_rx_stat).dropped++;
	local_irq_restore(flags);

	kfree_skb(skb);
	return NET_RX_DROP;
}

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);

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static inline struct net_device *skb_bond(struct sk_buff *skb)
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{
	struct net_device *dev = skb->dev;

1620
	if (dev->master) {
1621
		if (skb_bond_should_drop(skb)) {
1622 1623 1624
			kfree_skb(skb);
			return NULL;
		}
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		skb->dev = dev->master;
1626
	}
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	return dev;
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}

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;

			BUG_TRAP(!atomic_read(&skb->users));
			__kfree_skb(skb);
		}
	}

	if (sd->output_queue) {
		struct net_device *head;

		local_irq_disable();
		head = sd->output_queue;
		sd->output_queue = NULL;
		local_irq_enable();

		while (head) {
			struct net_device *dev = head;
			head = head->next_sched;

			smp_mb__before_clear_bit();
			clear_bit(__LINK_STATE_SCHED, &dev->state);

			if (spin_trylock(&dev->queue_lock)) {
				qdisc_run(dev);
				spin_unlock(&dev->queue_lock);
			} else {
				netif_schedule(dev);
			}
		}
	}
}

1677 1678 1679
static inline int deliver_skb(struct sk_buff *skb,
			      struct packet_type *pt_prev,
			      struct net_device *orig_dev)
L
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1680 1681
{
	atomic_inc(&skb->users);
D
David S. Miller 已提交
1682
	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
L
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}

#if defined(CONFIG_BRIDGE) || defined (CONFIG_BRIDGE_MODULE)
int (*br_handle_frame_hook)(struct net_bridge_port *p, struct sk_buff **pskb);
struct net_bridge;
struct net_bridge_fdb_entry *(*br_fdb_get_hook)(struct net_bridge *br,
						unsigned char *addr);
void (*br_fdb_put_hook)(struct net_bridge_fdb_entry *ent);

static __inline__ int handle_bridge(struct sk_buff **pskb,
D
David S. Miller 已提交
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				    struct packet_type **pt_prev, int *ret,
				    struct net_device *orig_dev)
L
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{
	struct net_bridge_port *port;

	if ((*pskb)->pkt_type == PACKET_LOOPBACK ||
	    (port = rcu_dereference((*pskb)->dev->br_port)) == NULL)
		return 0;

	if (*pt_prev) {
D
David S. Miller 已提交
1703
		*ret = deliver_skb(*pskb, *pt_prev, orig_dev);
L
Linus Torvalds 已提交
1704
		*pt_prev = NULL;
1705 1706
	}

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1707 1708 1709
	return br_handle_frame_hook(port, pskb);
}
#else
D
David S. Miller 已提交
1710
#define handle_bridge(skb, pt_prev, ret, orig_dev)	(0)
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1711 1712 1713 1714 1715 1716 1717
#endif

#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
1718
 * NOTE: This doesnt stop any functionality; if you dont have
L
Linus Torvalds 已提交
1719 1720 1721
 * the ingress scheduler, you just cant add policies on ingress.
 *
 */
1722
static int ing_filter(struct sk_buff *skb)
L
Linus Torvalds 已提交
1723 1724 1725 1726
{
	struct Qdisc *q;
	struct net_device *dev = skb->dev;
	int result = TC_ACT_OK;
1727

L
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1728 1729 1730
	if (dev->qdisc_ingress) {
		__u32 ttl = (__u32) G_TC_RTTL(skb->tc_verd);
		if (MAX_RED_LOOP < ttl++) {
1731 1732
			printk(KERN_WARNING "Redir loop detected Dropping packet (%d->%d)\n",
				skb->iif, skb->dev->ifindex);
L
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1733 1734 1735 1736 1737 1738
			return TC_ACT_SHOT;
		}

		skb->tc_verd = SET_TC_RTTL(skb->tc_verd,ttl);

		skb->tc_verd = SET_TC_AT(skb->tc_verd,AT_INGRESS);
1739

1740
		spin_lock(&dev->queue_lock);
L
Linus Torvalds 已提交
1741 1742
		if ((q = dev->qdisc_ingress) != NULL)
			result = q->enqueue(skb, q);
1743
		spin_unlock(&dev->queue_lock);
L
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1744 1745 1746 1747 1748 1749 1750 1751 1752 1753

	}

	return result;
}
#endif

int netif_receive_skb(struct sk_buff *skb)
{
	struct packet_type *ptype, *pt_prev;
D
David S. Miller 已提交
1754
	struct net_device *orig_dev;
L
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1755
	int ret = NET_RX_DROP;
A
Al Viro 已提交
1756
	__be16 type;
L
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1757 1758 1759 1760 1761

	/* if we've gotten here through NAPI, check netpoll */
	if (skb->dev->poll && netpoll_rx(skb))
		return NET_RX_DROP;

1762
	if (!skb->tstamp.tv64)
1763
		net_timestamp(skb);
L
Linus Torvalds 已提交
1764

1765 1766
	if (!skb->iif)
		skb->iif = skb->dev->ifindex;
1767

D
David S. Miller 已提交
1768
	orig_dev = skb_bond(skb);
L
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1769

1770 1771 1772
	if (!orig_dev)
		return NET_RX_DROP;

L
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	__get_cpu_var(netdev_rx_stat).total++;

1775
	skb_reset_network_header(skb);
1776
	skb_reset_transport_header(skb);
L
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1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791
	skb->mac_len = skb->nh.raw - skb->mac.raw;

	pt_prev = NULL;

	rcu_read_lock();

#ifdef CONFIG_NET_CLS_ACT
	if (skb->tc_verd & TC_NCLS) {
		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
		goto ncls;
	}
#endif

	list_for_each_entry_rcu(ptype, &ptype_all, list) {
		if (!ptype->dev || ptype->dev == skb->dev) {
1792
			if (pt_prev)
D
David S. Miller 已提交
1793
				ret = deliver_skb(skb, pt_prev, orig_dev);
L
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1794 1795 1796 1797 1798 1799
			pt_prev = ptype;
		}
	}

#ifdef CONFIG_NET_CLS_ACT
	if (pt_prev) {
D
David S. Miller 已提交
1800
		ret = deliver_skb(skb, pt_prev, orig_dev);
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1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816
		pt_prev = NULL; /* noone else should process this after*/
	} else {
		skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
	}

	ret = ing_filter(skb);

	if (ret == TC_ACT_SHOT || (ret == TC_ACT_STOLEN)) {
		kfree_skb(skb);
		goto out;
	}

	skb->tc_verd = 0;
ncls:
#endif

D
David S. Miller 已提交
1817
	if (handle_bridge(&skb, &pt_prev, &ret, orig_dev))
L
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1818 1819 1820 1821 1822 1823
		goto out;

	type = skb->protocol;
	list_for_each_entry_rcu(ptype, &ptype_base[ntohs(type)&15], list) {
		if (ptype->type == type &&
		    (!ptype->dev || ptype->dev == skb->dev)) {
1824
			if (pt_prev)
D
David S. Miller 已提交
1825
				ret = deliver_skb(skb, pt_prev, orig_dev);
L
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1826 1827 1828 1829 1830
			pt_prev = ptype;
		}
	}

	if (pt_prev) {
D
David S. Miller 已提交
1831
		ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
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	} else {
		kfree_skb(skb);
		/* Jamal, now you will not able to escape explaining
		 * me how you were going to use this. :-)
		 */
		ret = NET_RX_DROP;
	}

out:
	rcu_read_unlock();
	return ret;
}

static int process_backlog(struct net_device *backlog_dev, int *budget)
{
	int work = 0;
	int quota = min(backlog_dev->quota, *budget);
	struct softnet_data *queue = &__get_cpu_var(softnet_data);
	unsigned long start_time = jiffies;

1852
	backlog_dev->weight = weight_p;
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	for (;;) {
		struct sk_buff *skb;
		struct net_device *dev;

		local_irq_disable();
		skb = __skb_dequeue(&queue->input_pkt_queue);
		if (!skb)
			goto job_done;
		local_irq_enable();

		dev = skb->dev;

		netif_receive_skb(skb);

		dev_put(dev);

		work++;

		if (work >= quota || jiffies - start_time > 1)
			break;

	}

	backlog_dev->quota -= work;
	*budget -= work;
	return -1;

job_done:
	backlog_dev->quota -= work;
	*budget -= work;

	list_del(&backlog_dev->poll_list);
	smp_mb__before_clear_bit();
	netif_poll_enable(backlog_dev);

	local_irq_enable();
	return 0;
}

static void net_rx_action(struct softirq_action *h)
{
	struct softnet_data *queue = &__get_cpu_var(softnet_data);
	unsigned long start_time = jiffies;
1896
	int budget = netdev_budget;
1897 1898
	void *have;

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	local_irq_disable();

	while (!list_empty(&queue->poll_list)) {
		struct net_device *dev;

		if (budget <= 0 || jiffies - start_time > 1)
			goto softnet_break;

		local_irq_enable();

		dev = list_entry(queue->poll_list.next,
				 struct net_device, poll_list);
1911
		have = netpoll_poll_lock(dev);
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		if (dev->quota <= 0 || dev->poll(dev, &budget)) {
1914
			netpoll_poll_unlock(have);
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			local_irq_disable();
1916
			list_move_tail(&dev->poll_list, &queue->poll_list);
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			if (dev->quota < 0)
				dev->quota += dev->weight;
			else
				dev->quota = dev->weight;
		} else {
1922
			netpoll_poll_unlock(have);
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			dev_put(dev);
			local_irq_disable();
		}
	}
out:
1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940
#ifdef CONFIG_NET_DMA
	/*
	 * There may not be any more sk_buffs coming right now, so push
	 * any pending DMA copies to hardware
	 */
	if (net_dma_client) {
		struct dma_chan *chan;
		rcu_read_lock();
		list_for_each_entry_rcu(chan, &net_dma_client->channels, client_node)
			dma_async_memcpy_issue_pending(chan);
		rcu_read_unlock();
	}
#endif
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	local_irq_enable();
	return;

softnet_break:
	__get_cpu_var(netdev_rx_stat).time_squeeze++;
	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
	goto out;
}

static gifconf_func_t * gifconf_list [NPROTO];

/**
 *	register_gifconf	-	register a SIOCGIF handler
 *	@family: Address family
 *	@gifconf: Function handler
 *
 *	Register protocol dependent address dumping routines. The handler
 *	that is passed must not be freed or reused until it has been replaced
 *	by another handler.
 */
int register_gifconf(unsigned int family, gifconf_func_t * gifconf)
{
	if (family >= NPROTO)
		return -EINVAL;
	gifconf_list[family] = gifconf;
	return 0;
}


/*
 *	Map an interface index to its name (SIOCGIFNAME)
 */

/*
 *	We need this ioctl for efficient implementation of the
 *	if_indextoname() function required by the IPv6 API.  Without
 *	it, we would have to search all the interfaces to find a
 *	match.  --pb
 */

static int dev_ifname(struct ifreq __user *arg)
{
	struct net_device *dev;
	struct ifreq ifr;

	/*
	 *	Fetch the caller's info block.
	 */

	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
		return -EFAULT;

	read_lock(&dev_base_lock);
	dev = __dev_get_by_index(ifr.ifr_ifindex);
	if (!dev) {
		read_unlock(&dev_base_lock);
		return -ENODEV;
	}

	strcpy(ifr.ifr_name, dev->name);
	read_unlock(&dev_base_lock);

	if (copy_to_user(arg, &ifr, sizeof(struct ifreq)))
		return -EFAULT;
	return 0;
}

/*
 *	Perform a SIOCGIFCONF call. This structure will change
 *	size eventually, and there is nothing I can do about it.
 *	Thus we will need a 'compatibility mode'.
 */

static int dev_ifconf(char __user *arg)
{
	struct ifconf ifc;
	struct net_device *dev;
	char __user *pos;
	int len;
	int total;
	int i;

	/*
	 *	Fetch the caller's info block.
	 */

	if (copy_from_user(&ifc, arg, sizeof(struct ifconf)))
		return -EFAULT;

	pos = ifc.ifc_buf;
	len = ifc.ifc_len;

	/*
	 *	Loop over the interfaces, and write an info block for each.
	 */

	total = 0;
	for (dev = dev_base; dev; dev = dev->next) {
		for (i = 0; i < NPROTO; i++) {
			if (gifconf_list[i]) {
				int done;
				if (!pos)
					done = gifconf_list[i](dev, NULL, 0);
				else
					done = gifconf_list[i](dev, pos + total,
							       len - total);
				if (done < 0)
					return -EFAULT;
				total += done;
			}
		}
2052
	}
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	/*
	 *	All done.  Write the updated control block back to the caller.
	 */
	ifc.ifc_len = total;

	/*
	 * 	Both BSD and Solaris return 0 here, so we do too.
	 */
	return copy_to_user(arg, &ifc, sizeof(struct ifconf)) ? -EFAULT : 0;
}

#ifdef CONFIG_PROC_FS
/*
 *	This is invoked by the /proc filesystem handler to display a device
 *	in detail.
 */
2070
static struct net_device *dev_get_idx(loff_t pos)
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{
	struct net_device *dev;
	loff_t i;

	for (i = 0, dev = dev_base; dev && i < pos; ++i, dev = dev->next);

	return i == pos ? dev : NULL;
}

void *dev_seq_start(struct seq_file *seq, loff_t *pos)
{
	read_lock(&dev_base_lock);
	return *pos ? dev_get_idx(*pos - 1) : SEQ_START_TOKEN;
}

void *dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	++*pos;
	return v == SEQ_START_TOKEN ? dev_base : ((struct net_device *)v)->next;
}

void dev_seq_stop(struct seq_file *seq, void *v)
{
	read_unlock(&dev_base_lock);
}

static void dev_seq_printf_stats(struct seq_file *seq, struct net_device *dev)
{
	if (dev->get_stats) {
		struct net_device_stats *stats = dev->get_stats(dev);

		seq_printf(seq, "%6s:%8lu %7lu %4lu %4lu %4lu %5lu %10lu %9lu "
				"%8lu %7lu %4lu %4lu %4lu %5lu %7lu %10lu\n",
			   dev->name, stats->rx_bytes, stats->rx_packets,
			   stats->rx_errors,
			   stats->rx_dropped + stats->rx_missed_errors,
			   stats->rx_fifo_errors,
			   stats->rx_length_errors + stats->rx_over_errors +
			     stats->rx_crc_errors + stats->rx_frame_errors,
			   stats->rx_compressed, stats->multicast,
			   stats->tx_bytes, stats->tx_packets,
			   stats->tx_errors, stats->tx_dropped,
			   stats->tx_fifo_errors, stats->collisions,
			   stats->tx_carrier_errors +
			     stats->tx_aborted_errors +
			     stats->tx_window_errors +
			     stats->tx_heartbeat_errors,
			   stats->tx_compressed);
	} else
		seq_printf(seq, "%6s: No statistics available.\n", dev->name);
}

/*
 *	Called from the PROCfs module. This now uses the new arbitrary sized
 *	/proc/net interface to create /proc/net/dev
 */
static int dev_seq_show(struct seq_file *seq, void *v)
{
	if (v == SEQ_START_TOKEN)
		seq_puts(seq, "Inter-|   Receive                            "
			      "                    |  Transmit\n"
			      " face |bytes    packets errs drop fifo frame "
			      "compressed multicast|bytes    packets errs "
			      "drop fifo colls carrier compressed\n");
	else
		dev_seq_printf_stats(seq, v);
	return 0;
}

static struct netif_rx_stats *softnet_get_online(loff_t *pos)
{
	struct netif_rx_stats *rc = NULL;

	while (*pos < NR_CPUS)
2145
		if (cpu_online(*pos)) {
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			rc = &per_cpu(netdev_rx_stat, *pos);
			break;
		} else
			++*pos;
	return rc;
}

static void *softnet_seq_start(struct seq_file *seq, loff_t *pos)
{
	return softnet_get_online(pos);
}

static void *softnet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	++*pos;
	return softnet_get_online(pos);
}

static void softnet_seq_stop(struct seq_file *seq, void *v)
{
}

static int softnet_seq_show(struct seq_file *seq, void *v)
{
	struct netif_rx_stats *s = v;

	seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x %08x\n",
2173
		   s->total, s->dropped, s->time_squeeze, 0,
2174 2175
		   0, 0, 0, 0, /* was fastroute */
		   s->cpu_collision );
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	return 0;
}

2179
static const struct seq_operations dev_seq_ops = {
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	.start = dev_seq_start,
	.next  = dev_seq_next,
	.stop  = dev_seq_stop,
	.show  = dev_seq_show,
};

static int dev_seq_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &dev_seq_ops);
}

2191
static const struct file_operations dev_seq_fops = {
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	.owner	 = THIS_MODULE,
	.open    = dev_seq_open,
	.read    = seq_read,
	.llseek  = seq_lseek,
	.release = seq_release,
};

2199
static const struct seq_operations softnet_seq_ops = {
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	.start = softnet_seq_start,
	.next  = softnet_seq_next,
	.stop  = softnet_seq_stop,
	.show  = softnet_seq_show,
};

static int softnet_seq_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &softnet_seq_ops);
}

2211
static const struct file_operations softnet_seq_fops = {
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	.owner	 = THIS_MODULE,
	.open    = softnet_seq_open,
	.read    = seq_read,
	.llseek  = seq_lseek,
	.release = seq_release,
};

2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 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 2347
static void *ptype_get_idx(loff_t pos)
{
	struct packet_type *pt = NULL;
	loff_t i = 0;
	int t;

	list_for_each_entry_rcu(pt, &ptype_all, list) {
		if (i == pos)
			return pt;
		++i;
	}

	for (t = 0; t < 16; t++) {
		list_for_each_entry_rcu(pt, &ptype_base[t], list) {
			if (i == pos)
				return pt;
			++i;
		}
	}
	return NULL;
}

static void *ptype_seq_start(struct seq_file *seq, loff_t *pos)
{
	rcu_read_lock();
	return *pos ? ptype_get_idx(*pos - 1) : SEQ_START_TOKEN;
}

static void *ptype_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct packet_type *pt;
	struct list_head *nxt;
	int hash;

	++*pos;
	if (v == SEQ_START_TOKEN)
		return ptype_get_idx(0);

	pt = v;
	nxt = pt->list.next;
	if (pt->type == htons(ETH_P_ALL)) {
		if (nxt != &ptype_all)
			goto found;
		hash = 0;
		nxt = ptype_base[0].next;
	} else
		hash = ntohs(pt->type) & 15;

	while (nxt == &ptype_base[hash]) {
		if (++hash >= 16)
			return NULL;
		nxt = ptype_base[hash].next;
	}
found:
	return list_entry(nxt, struct packet_type, list);
}

static void ptype_seq_stop(struct seq_file *seq, void *v)
{
	rcu_read_unlock();
}

static void ptype_seq_decode(struct seq_file *seq, void *sym)
{
#ifdef CONFIG_KALLSYMS
	unsigned long offset = 0, symsize;
	const char *symname;
	char *modname;
	char namebuf[128];

	symname = kallsyms_lookup((unsigned long)sym, &symsize, &offset,
				  &modname, namebuf);

	if (symname) {
		char *delim = ":";

		if (!modname)
			modname = delim = "";
		seq_printf(seq, "%s%s%s%s+0x%lx", delim, modname, delim,
			   symname, offset);
		return;
	}
#endif

	seq_printf(seq, "[%p]", sym);
}

static int ptype_seq_show(struct seq_file *seq, void *v)
{
	struct packet_type *pt = v;

	if (v == SEQ_START_TOKEN)
		seq_puts(seq, "Type Device      Function\n");
	else {
		if (pt->type == htons(ETH_P_ALL))
			seq_puts(seq, "ALL ");
		else
			seq_printf(seq, "%04x", ntohs(pt->type));

		seq_printf(seq, " %-8s ",
			   pt->dev ? pt->dev->name : "");
		ptype_seq_decode(seq,  pt->func);
		seq_putc(seq, '\n');
	}

	return 0;
}

static const struct seq_operations ptype_seq_ops = {
	.start = ptype_seq_start,
	.next  = ptype_seq_next,
	.stop  = ptype_seq_stop,
	.show  = ptype_seq_show,
};

static int ptype_seq_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &ptype_seq_ops);
}

static const struct file_operations ptype_seq_fops = {
	.owner	 = THIS_MODULE,
	.open    = ptype_seq_open,
	.read    = seq_read,
	.llseek  = seq_lseek,
	.release = seq_release,
};


2348
#ifdef CONFIG_WIRELESS_EXT
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extern int wireless_proc_init(void);
#else
#define wireless_proc_init() 0
#endif

static int __init dev_proc_init(void)
{
	int rc = -ENOMEM;

	if (!proc_net_fops_create("dev", S_IRUGO, &dev_seq_fops))
		goto out;
	if (!proc_net_fops_create("softnet_stat", S_IRUGO, &softnet_seq_fops))
		goto out_dev;
2362 2363 2364
	if (!proc_net_fops_create("ptype", S_IRUGO, &ptype_seq_fops))
		goto out_dev2;

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	if (wireless_proc_init())
		goto out_softnet;
	rc = 0;
out:
	return rc;
out_softnet:
	proc_net_remove("softnet_stat");
2372 2373
out_dev2:
	proc_net_remove("ptype");
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out_dev:
	proc_net_remove("dev");
	goto out;
}
#else
#define dev_proc_init() 0
#endif	/* CONFIG_PROC_FS */


/**
 *	netdev_set_master	-	set up master/slave pair
 *	@slave: slave device
 *	@master: new master device
 *
 *	Changes the master device of the slave. Pass %NULL to break the
 *	bonding. The caller must hold the RTNL semaphore. On a failure
 *	a negative errno code is returned. On success the reference counts
 *	are adjusted, %RTM_NEWLINK is sent to the routing socket and the
 *	function returns zero.
 */
int netdev_set_master(struct net_device *slave, struct net_device *master)
{
	struct net_device *old = slave->master;

	ASSERT_RTNL();

	if (master) {
		if (old)
			return -EBUSY;
		dev_hold(master);
	}

	slave->master = master;
2407

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	synchronize_net();

	if (old)
		dev_put(old);

	if (master)
		slave->flags |= IFF_SLAVE;
	else
		slave->flags &= ~IFF_SLAVE;

	rtmsg_ifinfo(RTM_NEWLINK, slave, IFF_SLAVE);
	return 0;
}

/**
 *	dev_set_promiscuity	- update promiscuity count on a device
 *	@dev: device
 *	@inc: modifier
 *
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Stephen Hemminger 已提交
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 *	Add or remove promiscuity from a device. While the count in the device
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 *	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.
 */
void dev_set_promiscuity(struct net_device *dev, int inc)
{
	unsigned short old_flags = dev->flags;

	if ((dev->promiscuity += inc) == 0)
		dev->flags &= ~IFF_PROMISC;
2438 2439 2440
	else
		dev->flags |= IFF_PROMISC;
	if (dev->flags != old_flags) {
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		dev_mc_upload(dev);
		printk(KERN_INFO "device %s %s promiscuous mode\n",
		       dev->name, (dev->flags & IFF_PROMISC) ? "entered" :
2444
							       "left");
S
Steve Grubb 已提交
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		audit_log(current->audit_context, GFP_ATOMIC,
			AUDIT_ANOM_PROMISCUOUS,
			"dev=%s prom=%d old_prom=%d auid=%u",
			dev->name, (dev->flags & IFF_PROMISC),
			(old_flags & IFF_PROMISC),
2450
			audit_get_loginuid(current->audit_context));
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	}
}

/**
 *	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.
 */

void dev_set_allmulti(struct net_device *dev, int inc)
{
	unsigned short old_flags = dev->flags;

	dev->flags |= IFF_ALLMULTI;
	if ((dev->allmulti += inc) == 0)
		dev->flags &= ~IFF_ALLMULTI;
	if (dev->flags ^ old_flags)
		dev_mc_upload(dev);
}

unsigned dev_get_flags(const struct net_device *dev)
{
	unsigned flags;

	flags = (dev->flags & ~(IFF_PROMISC |
				IFF_ALLMULTI |
S
Stefan Rompf 已提交
2483 2484 2485
				IFF_RUNNING |
				IFF_LOWER_UP |
				IFF_DORMANT)) |
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2486 2487 2488
		(dev->gflags & (IFF_PROMISC |
				IFF_ALLMULTI));

S
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	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;
	}
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	return flags;
}

int dev_change_flags(struct net_device *dev, unsigned flags)
{
	int ret;
	int old_flags = dev->flags;

	/*
	 *	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.
	 */

	dev_mc_upload(dev);

	/*
	 *	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  ? */
		ret = ((old_flags & IFF_UP) ? dev_close : dev_open)(dev);

		if (!ret)
			dev_mc_upload(dev);
	}

	if (dev->flags & IFF_UP &&
	    ((old_flags ^ dev->flags) &~ (IFF_UP | IFF_PROMISC | IFF_ALLMULTI |
					  IFF_VOLATILE)))
2539
		raw_notifier_call_chain(&netdev_chain,
2540
				NETDEV_CHANGE, dev);
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	if ((flags ^ dev->gflags) & IFF_PROMISC) {
		int inc = (flags & IFF_PROMISC) ? +1 : -1;
		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) {
		int inc = (flags & IFF_ALLMULTI) ? +1 : -1;
		dev->gflags ^= IFF_ALLMULTI;
		dev_set_allmulti(dev, inc);
	}

	if (old_flags ^ dev->flags)
		rtmsg_ifinfo(RTM_NEWLINK, dev, old_flags ^ dev->flags);

	return ret;
}

int dev_set_mtu(struct net_device *dev, int new_mtu)
{
	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;
	if (dev->change_mtu)
		err = dev->change_mtu(dev, new_mtu);
	else
		dev->mtu = new_mtu;
	if (!err && dev->flags & IFF_UP)
2584
		raw_notifier_call_chain(&netdev_chain,
2585
				NETDEV_CHANGEMTU, dev);
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	return err;
}

int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
{
	int err;

	if (!dev->set_mac_address)
		return -EOPNOTSUPP;
	if (sa->sa_family != dev->type)
		return -EINVAL;
	if (!netif_device_present(dev))
		return -ENODEV;
	err = dev->set_mac_address(dev, sa);
	if (!err)
2601
		raw_notifier_call_chain(&netdev_chain,
2602
				NETDEV_CHANGEADDR, dev);
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	return err;
}

/*
 *	Perform the SIOCxIFxxx calls.
 */
static int dev_ifsioc(struct ifreq *ifr, unsigned int cmd)
{
	int err;
	struct net_device *dev = __dev_get_by_name(ifr->ifr_name);

	if (!dev)
		return -ENODEV;

	switch (cmd) {
		case SIOCGIFFLAGS:	/* Get interface flags */
			ifr->ifr_flags = dev_get_flags(dev);
			return 0;

		case SIOCSIFFLAGS:	/* Set interface flags */
			return dev_change_flags(dev, ifr->ifr_flags);

		case SIOCGIFMETRIC:	/* Get the metric on the interface
					   (currently unused) */
			ifr->ifr_metric = 0;
			return 0;

		case SIOCSIFMETRIC:	/* Set the metric on the interface
					   (currently unused) */
			return -EOPNOTSUPP;

		case SIOCGIFMTU:	/* Get the MTU of a device */
			ifr->ifr_mtu = dev->mtu;
			return 0;

		case SIOCSIFMTU:	/* Set the MTU of a device */
			return dev_set_mtu(dev, ifr->ifr_mtu);

		case SIOCGIFHWADDR:
			if (!dev->addr_len)
				memset(ifr->ifr_hwaddr.sa_data, 0, sizeof ifr->ifr_hwaddr.sa_data);
			else
				memcpy(ifr->ifr_hwaddr.sa_data, dev->dev_addr,
				       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
			ifr->ifr_hwaddr.sa_family = dev->type;
			return 0;

		case SIOCSIFHWADDR:
			return dev_set_mac_address(dev, &ifr->ifr_hwaddr);

		case SIOCSIFHWBROADCAST:
			if (ifr->ifr_hwaddr.sa_family != dev->type)
				return -EINVAL;
			memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
			       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
2658
			raw_notifier_call_chain(&netdev_chain,
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					    NETDEV_CHANGEADDR, dev);
			return 0;

		case SIOCGIFMAP:
			ifr->ifr_map.mem_start = dev->mem_start;
			ifr->ifr_map.mem_end   = dev->mem_end;
			ifr->ifr_map.base_addr = dev->base_addr;
			ifr->ifr_map.irq       = dev->irq;
			ifr->ifr_map.dma       = dev->dma;
			ifr->ifr_map.port      = dev->if_port;
			return 0;

		case SIOCSIFMAP:
			if (dev->set_config) {
				if (!netif_device_present(dev))
					return -ENODEV;
				return dev->set_config(dev, &ifr->ifr_map);
			}
			return -EOPNOTSUPP;

		case SIOCADDMULTI:
			if (!dev->set_multicast_list ||
			    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
				return -EINVAL;
			if (!netif_device_present(dev))
				return -ENODEV;
			return dev_mc_add(dev, ifr->ifr_hwaddr.sa_data,
					  dev->addr_len, 1);

		case SIOCDELMULTI:
			if (!dev->set_multicast_list ||
			    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
				return -EINVAL;
			if (!netif_device_present(dev))
				return -ENODEV;
			return dev_mc_delete(dev, ifr->ifr_hwaddr.sa_data,
					     dev->addr_len, 1);

		case SIOCGIFINDEX:
			ifr->ifr_ifindex = dev->ifindex;
			return 0;

		case SIOCGIFTXQLEN:
			ifr->ifr_qlen = dev->tx_queue_len;
			return 0;

		case SIOCSIFTXQLEN:
			if (ifr->ifr_qlen < 0)
				return -EINVAL;
			dev->tx_queue_len = ifr->ifr_qlen;
			return 0;

		case SIOCSIFNAME:
			ifr->ifr_newname[IFNAMSIZ-1] = '\0';
			return dev_change_name(dev, ifr->ifr_newname);

		/*
		 *	Unknown or private ioctl
		 */

		default:
			if ((cmd >= SIOCDEVPRIVATE &&
			    cmd <= SIOCDEVPRIVATE + 15) ||
			    cmd == SIOCBONDENSLAVE ||
			    cmd == SIOCBONDRELEASE ||
			    cmd == SIOCBONDSETHWADDR ||
			    cmd == SIOCBONDSLAVEINFOQUERY ||
			    cmd == SIOCBONDINFOQUERY ||
			    cmd == SIOCBONDCHANGEACTIVE ||
			    cmd == SIOCGMIIPHY ||
			    cmd == SIOCGMIIREG ||
			    cmd == SIOCSMIIREG ||
			    cmd == SIOCBRADDIF ||
			    cmd == SIOCBRDELIF ||
			    cmd == SIOCWANDEV) {
				err = -EOPNOTSUPP;
				if (dev->do_ioctl) {
					if (netif_device_present(dev))
						err = dev->do_ioctl(dev, ifr,
								    cmd);
					else
						err = -ENODEV;
				}
			} else
				err = -EINVAL;

	}
	return err;
}

/*
 *	This function handles all "interface"-type I/O control requests. The actual
 *	'doing' part of this is dev_ifsioc above.
 */

/**
 *	dev_ioctl	-	network device ioctl
 *	@cmd: command to issue
 *	@arg: pointer to a struct ifreq in user space
 *
 *	Issue ioctl functions to devices. This is normally called by the
 *	user space syscall interfaces but can sometimes be useful for
 *	other purposes. The return value is the return from the syscall if
 *	positive or a negative errno code on error.
 */

int dev_ioctl(unsigned int cmd, void __user *arg)
{
	struct ifreq ifr;
	int ret;
	char *colon;

	/* One special case: SIOCGIFCONF takes ifconf argument
	   and requires shared lock, because it sleeps writing
	   to user space.
	 */

	if (cmd == SIOCGIFCONF) {
2777
		rtnl_lock();
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		ret = dev_ifconf((char __user *) arg);
2779
		rtnl_unlock();
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		return ret;
	}
	if (cmd == SIOCGIFNAME)
		return dev_ifname((struct ifreq __user *)arg);

	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
		return -EFAULT;

	ifr.ifr_name[IFNAMSIZ-1] = 0;

	colon = strchr(ifr.ifr_name, ':');
	if (colon)
		*colon = 0;

	/*
	 *	See which interface the caller is talking about.
	 */

	switch (cmd) {
		/*
		 *	These ioctl calls:
		 *	- can be done by all.
		 *	- atomic and do not require locking.
		 *	- return a value
		 */
		case SIOCGIFFLAGS:
		case SIOCGIFMETRIC:
		case SIOCGIFMTU:
		case SIOCGIFHWADDR:
		case SIOCGIFSLAVE:
		case SIOCGIFMAP:
		case SIOCGIFINDEX:
		case SIOCGIFTXQLEN:
			dev_load(ifr.ifr_name);
			read_lock(&dev_base_lock);
			ret = dev_ifsioc(&ifr, cmd);
			read_unlock(&dev_base_lock);
			if (!ret) {
				if (colon)
					*colon = ':';
				if (copy_to_user(arg, &ifr,
						 sizeof(struct ifreq)))
					ret = -EFAULT;
			}
			return ret;

		case SIOCETHTOOL:
			dev_load(ifr.ifr_name);
			rtnl_lock();
			ret = dev_ethtool(&ifr);
			rtnl_unlock();
			if (!ret) {
				if (colon)
					*colon = ':';
				if (copy_to_user(arg, &ifr,
						 sizeof(struct ifreq)))
					ret = -EFAULT;
			}
			return ret;

		/*
		 *	These ioctl calls:
		 *	- require superuser power.
		 *	- require strict serialization.
		 *	- return a value
		 */
		case SIOCGMIIPHY:
		case SIOCGMIIREG:
		case SIOCSIFNAME:
			if (!capable(CAP_NET_ADMIN))
				return -EPERM;
			dev_load(ifr.ifr_name);
			rtnl_lock();
			ret = dev_ifsioc(&ifr, cmd);
			rtnl_unlock();
			if (!ret) {
				if (colon)
					*colon = ':';
				if (copy_to_user(arg, &ifr,
						 sizeof(struct ifreq)))
					ret = -EFAULT;
			}
			return ret;

		/*
		 *	These ioctl calls:
		 *	- require superuser power.
		 *	- require strict serialization.
		 *	- do not return a value
		 */
		case SIOCSIFFLAGS:
		case SIOCSIFMETRIC:
		case SIOCSIFMTU:
		case SIOCSIFMAP:
		case SIOCSIFHWADDR:
		case SIOCSIFSLAVE:
		case SIOCADDMULTI:
		case SIOCDELMULTI:
		case SIOCSIFHWBROADCAST:
		case SIOCSIFTXQLEN:
		case SIOCSMIIREG:
		case SIOCBONDENSLAVE:
		case SIOCBONDRELEASE:
		case SIOCBONDSETHWADDR:
		case SIOCBONDCHANGEACTIVE:
		case SIOCBRADDIF:
		case SIOCBRDELIF:
			if (!capable(CAP_NET_ADMIN))
				return -EPERM;
2889 2890 2891
			/* fall through */
		case SIOCBONDSLAVEINFOQUERY:
		case SIOCBONDINFOQUERY:
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			dev_load(ifr.ifr_name);
			rtnl_lock();
			ret = dev_ifsioc(&ifr, cmd);
			rtnl_unlock();
			return ret;

		case SIOCGIFMEM:
			/* Get the per device memory space. We can add this but
			 * currently do not support it */
		case SIOCSIFMEM:
			/* Set the per device memory buffer space.
			 * Not applicable in our case */
		case SIOCSIFLINK:
			return -EINVAL;

		/*
		 *	Unknown or private ioctl.
		 */
		default:
			if (cmd == SIOCWANDEV ||
			    (cmd >= SIOCDEVPRIVATE &&
			     cmd <= SIOCDEVPRIVATE + 15)) {
				dev_load(ifr.ifr_name);
				rtnl_lock();
				ret = dev_ifsioc(&ifr, cmd);
				rtnl_unlock();
				if (!ret && copy_to_user(arg, &ifr,
							 sizeof(struct ifreq)))
					ret = -EFAULT;
				return ret;
			}
2923
#ifdef CONFIG_WIRELESS_EXT
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2924 2925 2926 2927 2928
			/* Take care of Wireless Extensions */
			if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) {
				/* If command is `set a parameter', or
				 * `get the encoding parameters', check if
				 * the user has the right to do it */
2929 2930
				if (IW_IS_SET(cmd) || cmd == SIOCGIWENCODE
				    || cmd == SIOCGIWENCODEEXT) {
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2931 2932 2933 2934 2935 2936 2937 2938 2939 2940
					if (!capable(CAP_NET_ADMIN))
						return -EPERM;
				}
				dev_load(ifr.ifr_name);
				rtnl_lock();
				/* Follow me in net/core/wireless.c */
				ret = wireless_process_ioctl(&ifr, cmd);
				rtnl_unlock();
				if (IW_IS_GET(cmd) &&
				    copy_to_user(arg, &ifr,
2941
						 sizeof(struct ifreq)))
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					ret = -EFAULT;
				return ret;
			}
2945
#endif	/* CONFIG_WIRELESS_EXT */
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			return -EINVAL;
	}
}


/**
 *	dev_new_index	-	allocate an ifindex
 *
 *	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.
 */
static int dev_new_index(void)
{
	static int ifindex;
	for (;;) {
		if (++ifindex <= 0)
			ifindex = 1;
		if (!__dev_get_by_index(ifindex))
			return ifindex;
	}
}

static int dev_boot_phase = 1;

/* Delayed registration/unregisteration */
static DEFINE_SPINLOCK(net_todo_list_lock);
static struct list_head net_todo_list = LIST_HEAD_INIT(net_todo_list);

2975
static void net_set_todo(struct net_device *dev)
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2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007
{
	spin_lock(&net_todo_list_lock);
	list_add_tail(&dev->todo_list, &net_todo_list);
	spin_unlock(&net_todo_list_lock);
}

/**
 *	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)
{
	struct hlist_head *head;
	struct hlist_node *p;
	int ret;

	BUG_ON(dev_boot_phase);
	ASSERT_RTNL();

3008 3009
	might_sleep();

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3010 3011 3012 3013
	/* When net_device's are persistent, this will be fatal. */
	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);

	spin_lock_init(&dev->queue_lock);
H
Herbert Xu 已提交
3014
	spin_lock_init(&dev->_xmit_lock);
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3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027
	dev->xmit_lock_owner = -1;
#ifdef CONFIG_NET_CLS_ACT
	spin_lock_init(&dev->ingress_lock);
#endif

	dev->iflink = -1;

	/* Init, if this function is available */
	if (dev->init) {
		ret = dev->init(dev);
		if (ret) {
			if (ret > 0)
				ret = -EIO;
3028
			goto out;
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3029 3030
		}
	}
3031

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3032 3033
	if (!dev_valid_name(dev->name)) {
		ret = -EINVAL;
3034
		goto out;
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3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047
	}

	dev->ifindex = dev_new_index();
	if (dev->iflink == -1)
		dev->iflink = dev->ifindex;

	/* Check for existence of name */
	head = dev_name_hash(dev->name);
	hlist_for_each(p, head) {
		struct net_device *d
			= hlist_entry(p, struct net_device, name_hlist);
		if (!strncmp(d->name, dev->name, IFNAMSIZ)) {
			ret = -EEXIST;
3048
			goto out;
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3049
		}
3050
	}
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3051 3052 3053

	/* Fix illegal SG+CSUM combinations. */
	if ((dev->features & NETIF_F_SG) &&
3054
	    !(dev->features & NETIF_F_ALL_CSUM)) {
3055
		printk(KERN_NOTICE "%s: Dropping NETIF_F_SG since no checksum feature.\n",
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3056 3057 3058 3059 3060 3061 3062
		       dev->name);
		dev->features &= ~NETIF_F_SG;
	}

	/* TSO requires that SG is present as well. */
	if ((dev->features & NETIF_F_TSO) &&
	    !(dev->features & NETIF_F_SG)) {
3063
		printk(KERN_NOTICE "%s: Dropping NETIF_F_TSO since no SG feature.\n",
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3064 3065 3066
		       dev->name);
		dev->features &= ~NETIF_F_TSO;
	}
3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080
	if (dev->features & NETIF_F_UFO) {
		if (!(dev->features & NETIF_F_HW_CSUM)) {
			printk(KERN_ERR "%s: Dropping NETIF_F_UFO since no "
					"NETIF_F_HW_CSUM feature.\n",
							dev->name);
			dev->features &= ~NETIF_F_UFO;
		}
		if (!(dev->features & NETIF_F_SG)) {
			printk(KERN_ERR "%s: Dropping NETIF_F_UFO since no "
					"NETIF_F_SG feature.\n",
					dev->name);
			dev->features &= ~NETIF_F_UFO;
		}
	}
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	/*
	 *	nil rebuild_header routine,
	 *	that should be never called and used as just bug trap.
	 */

	if (!dev->rebuild_header)
		dev->rebuild_header = default_rebuild_header;

3090 3091
	ret = netdev_register_sysfs(dev);
	if (ret)
3092
		goto out;
3093 3094
	dev->reg_state = NETREG_REGISTERED;

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	/*
	 *	Default initial state at registry is that the
	 *	device is present.
	 */

	set_bit(__LINK_STATE_PRESENT, &dev->state);

	dev->next = NULL;
	dev_init_scheduler(dev);
	write_lock_bh(&dev_base_lock);
	*dev_tail = dev;
	dev_tail = &dev->next;
	hlist_add_head(&dev->name_hlist, head);
	hlist_add_head(&dev->index_hlist, dev_index_hash(dev->ifindex));
	dev_hold(dev);
	write_unlock_bh(&dev_base_lock);

	/* Notify protocols, that a new device appeared. */
3113
	raw_notifier_call_chain(&netdev_chain, NETDEV_REGISTER, dev);
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	ret = 0;

out:
	return ret;
}

/**
 *	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.
 *
 *	This is a wrapper around register_netdev that takes the rtnl semaphore
 *	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();

	/*
	 * If the name is a format string the caller wants us to do a
	 * name allocation.
	 */
	if (strchr(dev->name, '%')) {
		err = dev_alloc_name(dev, dev->name);
		if (err < 0)
			goto out;
	}
3149

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	err = register_netdevice(dev);
out:
	rtnl_unlock();
	return err;
}
EXPORT_SYMBOL(register_netdev);

/*
 * netdev_wait_allrefs - wait until all references are gone.
 *
 * 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
3166
 * call dev_put.
L
Linus Torvalds 已提交
3167 3168 3169 3170 3171 3172 3173 3174
 */
static void netdev_wait_allrefs(struct net_device *dev)
{
	unsigned long rebroadcast_time, warning_time;

	rebroadcast_time = warning_time = jiffies;
	while (atomic_read(&dev->refcnt) != 0) {
		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
3175
			rtnl_lock();
L
Linus Torvalds 已提交
3176 3177

			/* Rebroadcast unregister notification */
3178
			raw_notifier_call_chain(&netdev_chain,
L
Linus Torvalds 已提交
3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191
					    NETDEV_UNREGISTER, dev);

			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();
			}

3192
			__rtnl_unlock();
L
Linus Torvalds 已提交
3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224

			rebroadcast_time = jiffies;
		}

		msleep(250);

		if (time_after(jiffies, warning_time + 10 * HZ)) {
			printk(KERN_EMERG "unregister_netdevice: "
			       "waiting for %s to become free. Usage "
			       "count = %d\n",
			       dev->name, atomic_read(&dev->refcnt));
			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);
 *
 * We are invoked by rtnl_unlock() after it drops the semaphore.
 * This allows us to deal with problems:
3225
 * 1) We can delete sysfs objects which invoke hotplug
L
Linus Torvalds 已提交
3226 3227 3228 3229
 *    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.
 */
A
Arjan van de Ven 已提交
3230
static DEFINE_MUTEX(net_todo_run_mutex);
L
Linus Torvalds 已提交
3231 3232
void netdev_run_todo(void)
{
3233
	struct list_head list;
L
Linus Torvalds 已提交
3234 3235

	/* Need to guard against multiple cpu's getting out of order. */
A
Arjan van de Ven 已提交
3236
	mutex_lock(&net_todo_run_mutex);
L
Linus Torvalds 已提交
3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247

	/* Not safe to do outside the semaphore.  We must not return
	 * until all unregister events invoked by the local processor
	 * have been completed (either by this todo run, or one on
	 * another cpu).
	 */
	if (list_empty(&net_todo_list))
		goto out;

	/* Snapshot list, allow later requests */
	spin_lock(&net_todo_list_lock);
3248
	list_replace_init(&net_todo_list, &list);
L
Linus Torvalds 已提交
3249
	spin_unlock(&net_todo_list_lock);
3250

L
Linus Torvalds 已提交
3251 3252 3253 3254 3255
	while (!list_empty(&list)) {
		struct net_device *dev
			= list_entry(list.next, struct net_device, todo_list);
		list_del(&dev->todo_list);

3256 3257 3258 3259 3260 3261
		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
			printk(KERN_ERR "network todo '%s' but state %d\n",
			       dev->name, dev->reg_state);
			dump_stack();
			continue;
		}
L
Linus Torvalds 已提交
3262

3263 3264
		netdev_unregister_sysfs(dev);
		dev->reg_state = NETREG_UNREGISTERED;
L
Linus Torvalds 已提交
3265

3266
		netdev_wait_allrefs(dev);
L
Linus Torvalds 已提交
3267

3268 3269 3270 3271 3272
		/* paranoia */
		BUG_ON(atomic_read(&dev->refcnt));
		BUG_TRAP(!dev->ip_ptr);
		BUG_TRAP(!dev->ip6_ptr);
		BUG_TRAP(!dev->dn_ptr);
L
Linus Torvalds 已提交
3273

3274 3275 3276 3277 3278
		/* It must be the very last action,
		 * after this 'dev' may point to freed up memory.
		 */
		if (dev->destructor)
			dev->destructor(dev);
L
Linus Torvalds 已提交
3279 3280 3281
	}

out:
A
Arjan van de Ven 已提交
3282
	mutex_unlock(&net_todo_run_mutex);
L
Linus Torvalds 已提交
3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300
}

/**
 *	alloc_netdev - allocate network device
 *	@sizeof_priv:	size of private data to allocate space for
 *	@name:		device name format string
 *	@setup:		callback to initialize device
 *
 *	Allocates a struct net_device with private data area for driver use
 *	and performs basic initialization.
 */
struct net_device *alloc_netdev(int sizeof_priv, const char *name,
		void (*setup)(struct net_device *))
{
	void *p;
	struct net_device *dev;
	int alloc_size;

3301 3302
	BUG_ON(strlen(name) >= sizeof(dev->name));

L
Linus Torvalds 已提交
3303 3304 3305 3306
	/* ensure 32-byte alignment of both the device and private area */
	alloc_size = (sizeof(*dev) + NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST;
	alloc_size += sizeof_priv + NETDEV_ALIGN_CONST;

3307
	p = kzalloc(alloc_size, GFP_KERNEL);
L
Linus Torvalds 已提交
3308
	if (!p) {
3309
		printk(KERN_ERR "alloc_netdev: Unable to allocate device.\n");
L
Linus Torvalds 已提交
3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329
		return NULL;
	}

	dev = (struct net_device *)
		(((long)p + NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST);
	dev->padded = (char *)dev - (char *)p;

	if (sizeof_priv)
		dev->priv = netdev_priv(dev);

	setup(dev);
	strcpy(dev->name, name);
	return dev;
}
EXPORT_SYMBOL(alloc_netdev);

/**
 *	free_netdev - free network device
 *	@dev: device
 *
3330 3331
 *	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
3332 3333 3334 3335 3336
 *	If this is the last reference then it will be freed.
 */
void free_netdev(struct net_device *dev)
{
#ifdef CONFIG_SYSFS
S
Stephen Hemminger 已提交
3337
	/*  Compatibility with error handling in drivers */
L
Linus Torvalds 已提交
3338 3339 3340 3341 3342 3343 3344 3345
	if (dev->reg_state == NETREG_UNINITIALIZED) {
		kfree((char *)dev - dev->padded);
		return;
	}

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

3346 3347
	/* will free via device release */
	put_device(&dev->dev);
L
Linus Torvalds 已提交
3348 3349 3350 3351
#else
	kfree((char *)dev - dev->padded);
#endif
}
3352

L
Linus Torvalds 已提交
3353
/* Synchronize with packet receive processing. */
3354
void synchronize_net(void)
L
Linus Torvalds 已提交
3355 3356
{
	might_sleep();
3357
	synchronize_rcu();
L
Linus Torvalds 已提交
3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371
}

/**
 *	unregister_netdevice - remove device from the kernel
 *	@dev: device
 *
 *	This function shuts down a device interface and removes it
 *	from the kernel tables. On success 0 is returned, on a failure
 *	a negative errno code is returned.
 *
 *	Callers must hold the rtnl semaphore.  You may want
 *	unregister_netdev() instead of this.
 */

3372
void unregister_netdevice(struct net_device *dev)
L
Linus Torvalds 已提交
3373 3374 3375 3376 3377 3378 3379 3380 3381 3382
{
	struct net_device *d, **dp;

	BUG_ON(dev_boot_phase);
	ASSERT_RTNL();

	/* Some devices call without registering for initialization unwind. */
	if (dev->reg_state == NETREG_UNINITIALIZED) {
		printk(KERN_DEBUG "unregister_netdevice: device %s/%p never "
				  "was registered\n", dev->name, dev);
3383 3384 3385

		WARN_ON(1);
		return;
L
Linus Torvalds 已提交
3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406
	}

	BUG_ON(dev->reg_state != NETREG_REGISTERED);

	/* If device is running, close it first. */
	if (dev->flags & IFF_UP)
		dev_close(dev);

	/* And unlink it from device chain. */
	for (dp = &dev_base; (d = *dp) != NULL; dp = &d->next) {
		if (d == dev) {
			write_lock_bh(&dev_base_lock);
			hlist_del(&dev->name_hlist);
			hlist_del(&dev->index_hlist);
			if (dev_tail == &dev->next)
				dev_tail = dp;
			*dp = d->next;
			write_unlock_bh(&dev_base_lock);
			break;
		}
	}
3407
	BUG_ON(!d);
L
Linus Torvalds 已提交
3408 3409 3410 3411 3412 3413 3414 3415

	dev->reg_state = NETREG_UNREGISTERING;

	synchronize_net();

	/* Shutdown queueing discipline. */
	dev_shutdown(dev);

3416

L
Linus Torvalds 已提交
3417 3418 3419
	/* Notify protocols, that we are about to destroy
	   this device. They should clean all the things.
	*/
3420
	raw_notifier_call_chain(&netdev_chain, NETDEV_UNREGISTER, dev);
3421

L
Linus Torvalds 已提交
3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505
	/*
	 *	Flush the multicast chain
	 */
	dev_mc_discard(dev);

	if (dev->uninit)
		dev->uninit(dev);

	/* Notifier chain MUST detach us from master device. */
	BUG_TRAP(!dev->master);

	/* Finish processing unregister after unlock */
	net_set_todo(dev);

	synchronize_net();

	dev_put(dev);
}

/**
 *	unregister_netdev - remove device from the kernel
 *	@dev: device
 *
 *	This function shuts down a device interface and removes it
 *	from the kernel tables. On success 0 is returned, on a failure
 *	a negative errno code is returned.
 *
 *	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);

static int dev_cpu_callback(struct notifier_block *nfb,
			    unsigned long action,
			    void *ocpu)
{
	struct sk_buff **list_skb;
	struct net_device **list_net;
	struct sk_buff *skb;
	unsigned int cpu, oldcpu = (unsigned long)ocpu;
	struct softnet_data *sd, *oldsd;

	if (action != CPU_DEAD)
		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;

	/* Find end of our output_queue. */
	list_net = &sd->output_queue;
	while (*list_net)
		list_net = &(*list_net)->next_sched;
	/* Append output queue from offline CPU. */
	*list_net = oldsd->output_queue;
	oldsd->output_queue = NULL;

	raise_softirq_irqoff(NET_TX_SOFTIRQ);
	local_irq_enable();

	/* Process offline CPU's input_pkt_queue */
	while ((skb = __skb_dequeue(&oldsd->input_pkt_queue)))
		netif_rx(skb);

	return NOTIFY_OK;
}

3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518
#ifdef CONFIG_NET_DMA
/**
 * net_dma_rebalance -
 * This is called when the number of channels allocated to the net_dma_client
 * changes.  The net_dma_client tries to have one DMA channel per CPU.
 */
static void net_dma_rebalance(void)
{
	unsigned int cpu, i, n;
	struct dma_chan *chan;

	if (net_dma_count == 0) {
		for_each_online_cpu(cpu)
A
Alexey Dobriyan 已提交
3519
			rcu_assign_pointer(per_cpu(softnet_data, cpu).net_dma, NULL);
3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531
		return;
	}

	i = 0;
	cpu = first_cpu(cpu_online_map);

	rcu_read_lock();
	list_for_each_entry(chan, &net_dma_client->channels, client_node) {
		n = ((num_online_cpus() / net_dma_count)
		   + (i < (num_online_cpus() % net_dma_count) ? 1 : 0));

		while(n) {
A
Alexey Dobriyan 已提交
3532
			per_cpu(softnet_data, cpu).net_dma = chan;
3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543
			cpu = next_cpu(cpu, cpu_online_map);
			n--;
		}
		i++;
	}
	rcu_read_unlock();
}

/**
 * netdev_dma_event - event callback for the net_dma_client
 * @client: should always be net_dma_client
R
Randy Dunlap 已提交
3544 3545
 * @chan: DMA channel for the event
 * @event: event type
3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582
 */
static void netdev_dma_event(struct dma_client *client, struct dma_chan *chan,
	enum dma_event event)
{
	spin_lock(&net_dma_event_lock);
	switch (event) {
	case DMA_RESOURCE_ADDED:
		net_dma_count++;
		net_dma_rebalance();
		break;
	case DMA_RESOURCE_REMOVED:
		net_dma_count--;
		net_dma_rebalance();
		break;
	default:
		break;
	}
	spin_unlock(&net_dma_event_lock);
}

/**
 * netdev_dma_regiser - register the networking subsystem as a DMA client
 */
static int __init netdev_dma_register(void)
{
	spin_lock_init(&net_dma_event_lock);
	net_dma_client = dma_async_client_register(netdev_dma_event);
	if (net_dma_client == NULL)
		return -ENOMEM;

	dma_async_client_chan_request(net_dma_client, num_online_cpus());
	return 0;
}

#else
static int __init netdev_dma_register(void) { return -ENODEV; }
#endif /* CONFIG_NET_DMA */
L
Linus Torvalds 已提交
3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607

/*
 *	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;

	if (netdev_sysfs_init())
		goto out;

	INIT_LIST_HEAD(&ptype_all);
3608
	for (i = 0; i < 16; i++)
L
Linus Torvalds 已提交
3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620
		INIT_LIST_HEAD(&ptype_base[i]);

	for (i = 0; i < ARRAY_SIZE(dev_name_head); i++)
		INIT_HLIST_HEAD(&dev_name_head[i]);

	for (i = 0; i < ARRAY_SIZE(dev_index_head); i++)
		INIT_HLIST_HEAD(&dev_index_head[i]);

	/*
	 *	Initialise the packet receive queues.
	 */

3621
	for_each_possible_cpu(i) {
L
Linus Torvalds 已提交
3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633
		struct softnet_data *queue;

		queue = &per_cpu(softnet_data, i);
		skb_queue_head_init(&queue->input_pkt_queue);
		queue->completion_queue = NULL;
		INIT_LIST_HEAD(&queue->poll_list);
		set_bit(__LINK_STATE_START, &queue->backlog_dev.state);
		queue->backlog_dev.weight = weight_p;
		queue->backlog_dev.poll = process_backlog;
		atomic_set(&queue->backlog_dev.refcnt, 1);
	}

3634 3635
	netdev_dma_register();

L
Linus Torvalds 已提交
3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653
	dev_boot_phase = 0;

	open_softirq(NET_TX_SOFTIRQ, net_tx_action, NULL);
	open_softirq(NET_RX_SOFTIRQ, net_rx_action, NULL);

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

subsys_initcall(net_dev_init);

EXPORT_SYMBOL(__dev_get_by_index);
EXPORT_SYMBOL(__dev_get_by_name);
EXPORT_SYMBOL(__dev_remove_pack);
3654
EXPORT_SYMBOL(dev_valid_name);
L
Linus Torvalds 已提交
3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696
EXPORT_SYMBOL(dev_add_pack);
EXPORT_SYMBOL(dev_alloc_name);
EXPORT_SYMBOL(dev_close);
EXPORT_SYMBOL(dev_get_by_flags);
EXPORT_SYMBOL(dev_get_by_index);
EXPORT_SYMBOL(dev_get_by_name);
EXPORT_SYMBOL(dev_open);
EXPORT_SYMBOL(dev_queue_xmit);
EXPORT_SYMBOL(dev_remove_pack);
EXPORT_SYMBOL(dev_set_allmulti);
EXPORT_SYMBOL(dev_set_promiscuity);
EXPORT_SYMBOL(dev_change_flags);
EXPORT_SYMBOL(dev_set_mtu);
EXPORT_SYMBOL(dev_set_mac_address);
EXPORT_SYMBOL(free_netdev);
EXPORT_SYMBOL(netdev_boot_setup_check);
EXPORT_SYMBOL(netdev_set_master);
EXPORT_SYMBOL(netdev_state_change);
EXPORT_SYMBOL(netif_receive_skb);
EXPORT_SYMBOL(netif_rx);
EXPORT_SYMBOL(register_gifconf);
EXPORT_SYMBOL(register_netdevice);
EXPORT_SYMBOL(register_netdevice_notifier);
EXPORT_SYMBOL(skb_checksum_help);
EXPORT_SYMBOL(synchronize_net);
EXPORT_SYMBOL(unregister_netdevice);
EXPORT_SYMBOL(unregister_netdevice_notifier);
EXPORT_SYMBOL(net_enable_timestamp);
EXPORT_SYMBOL(net_disable_timestamp);
EXPORT_SYMBOL(dev_get_flags);

#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
EXPORT_SYMBOL(br_handle_frame_hook);
EXPORT_SYMBOL(br_fdb_get_hook);
EXPORT_SYMBOL(br_fdb_put_hook);
#endif

#ifdef CONFIG_KMOD
EXPORT_SYMBOL(dev_load);
#endif

EXPORT_PER_CPU_SYMBOL(softnet_data);