xref: /linux/net/core/dev.c (revision 2a67789618abb74f0f97d4836a2b937bff2f1b2d)
1 /*
2  * 	NET3	Protocol independent device support routines.
3  *
4  *		This program is free software; you can redistribute it and/or
5  *		modify it under the terms of the GNU General Public License
6  *		as published by the Free Software Foundation; either version
7  *		2 of the License, or (at your option) any later version.
8  *
9  *	Derived from the non IP parts of dev.c 1.0.19
10  * 		Authors:	Ross Biro
11  *				Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12  *				Mark Evans, <evansmp@uhura.aston.ac.uk>
13  *
14  *	Additional Authors:
15  *		Florian la Roche <rzsfl@rz.uni-sb.de>
16  *		Alan Cox <gw4pts@gw4pts.ampr.org>
17  *		David Hinds <dahinds@users.sourceforge.net>
18  *		Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
19  *		Adam Sulmicki <adam@cfar.umd.edu>
20  *              Pekka Riikonen <priikone@poesidon.pspt.fi>
21  *
22  *	Changes:
23  *              D.J. Barrow     :       Fixed bug where dev->refcnt gets set
24  *              			to 2 if register_netdev gets called
25  *              			before net_dev_init & also removed a
26  *              			few lines of code in the process.
27  *		Alan Cox	:	device private ioctl copies fields back.
28  *		Alan Cox	:	Transmit queue code does relevant
29  *					stunts to keep the queue safe.
30  *		Alan Cox	:	Fixed double lock.
31  *		Alan Cox	:	Fixed promisc NULL pointer trap
32  *		????????	:	Support the full private ioctl range
33  *		Alan Cox	:	Moved ioctl permission check into
34  *					drivers
35  *		Tim Kordas	:	SIOCADDMULTI/SIOCDELMULTI
36  *		Alan Cox	:	100 backlog just doesn't cut it when
37  *					you start doing multicast video 8)
38  *		Alan Cox	:	Rewrote net_bh and list manager.
39  *		Alan Cox	: 	Fix ETH_P_ALL echoback lengths.
40  *		Alan Cox	:	Took out transmit every packet pass
41  *					Saved a few bytes in the ioctl handler
42  *		Alan Cox	:	Network driver sets packet type before
43  *					calling netif_rx. Saves a function
44  *					call a packet.
45  *		Alan Cox	:	Hashed net_bh()
46  *		Richard Kooijman:	Timestamp fixes.
47  *		Alan Cox	:	Wrong field in SIOCGIFDSTADDR
48  *		Alan Cox	:	Device lock protection.
49  *		Alan Cox	: 	Fixed nasty side effect of device close
50  *					changes.
51  *		Rudi Cilibrasi	:	Pass the right thing to
52  *					set_mac_address()
53  *		Dave Miller	:	32bit quantity for the device lock to
54  *					make it work out on a Sparc.
55  *		Bjorn Ekwall	:	Added KERNELD hack.
56  *		Alan Cox	:	Cleaned up the backlog initialise.
57  *		Craig Metz	:	SIOCGIFCONF fix if space for under
58  *					1 device.
59  *	    Thomas Bogendoerfer :	Return ENODEV for dev_open, if there
60  *					is no device open function.
61  *		Andi Kleen	:	Fix error reporting for SIOCGIFCONF
62  *	    Michael Chastain	:	Fix signed/unsigned for SIOCGIFCONF
63  *		Cyrus Durgin	:	Cleaned for KMOD
64  *		Adam Sulmicki   :	Bug Fix : Network Device Unload
65  *					A network device unload needs to purge
66  *					the backlog queue.
67  *	Paul Rusty Russell	:	SIOCSIFNAME
68  *              Pekka Riikonen  :	Netdev boot-time settings code
69  *              Andrew Morton   :       Make unregister_netdevice wait
70  *              			indefinitely on dev->refcnt
71  * 		J Hadi Salim	:	- Backlog queue sampling
72  *				        - netif_rx() feedback
73  */
74 
75 #include <asm/uaccess.h>
76 #include <asm/system.h>
77 #include <linux/bitops.h>
78 #include <linux/capability.h>
79 #include <linux/cpu.h>
80 #include <linux/types.h>
81 #include <linux/kernel.h>
82 #include <linux/sched.h>
83 #include <linux/mutex.h>
84 #include <linux/string.h>
85 #include <linux/mm.h>
86 #include <linux/socket.h>
87 #include <linux/sockios.h>
88 #include <linux/errno.h>
89 #include <linux/interrupt.h>
90 #include <linux/if_ether.h>
91 #include <linux/netdevice.h>
92 #include <linux/etherdevice.h>
93 #include <linux/notifier.h>
94 #include <linux/skbuff.h>
95 #include <net/sock.h>
96 #include <linux/rtnetlink.h>
97 #include <linux/proc_fs.h>
98 #include <linux/seq_file.h>
99 #include <linux/stat.h>
100 #include <linux/if_bridge.h>
101 #include <linux/if_macvlan.h>
102 #include <net/dst.h>
103 #include <net/pkt_sched.h>
104 #include <net/checksum.h>
105 #include <linux/highmem.h>
106 #include <linux/init.h>
107 #include <linux/kmod.h>
108 #include <linux/module.h>
109 #include <linux/kallsyms.h>
110 #include <linux/netpoll.h>
111 #include <linux/rcupdate.h>
112 #include <linux/delay.h>
113 #include <net/wext.h>
114 #include <net/iw_handler.h>
115 #include <asm/current.h>
116 #include <linux/audit.h>
117 #include <linux/dmaengine.h>
118 #include <linux/err.h>
119 #include <linux/ctype.h>
120 #include <linux/if_arp.h>
121 
122 /*
123  *	The list of packet types we will receive (as opposed to discard)
124  *	and the routines to invoke.
125  *
126  *	Why 16. Because with 16 the only overlap we get on a hash of the
127  *	low nibble of the protocol value is RARP/SNAP/X.25.
128  *
129  *      NOTE:  That is no longer true with the addition of VLAN tags.  Not
130  *             sure which should go first, but I bet it won't make much
131  *             difference if we are running VLANs.  The good news is that
132  *             this protocol won't be in the list unless compiled in, so
133  *             the average user (w/out VLANs) will not be adversely affected.
134  *             --BLG
135  *
136  *		0800	IP
137  *		8100    802.1Q VLAN
138  *		0001	802.3
139  *		0002	AX.25
140  *		0004	802.2
141  *		8035	RARP
142  *		0005	SNAP
143  *		0805	X.25
144  *		0806	ARP
145  *		8137	IPX
146  *		0009	Localtalk
147  *		86DD	IPv6
148  */
149 
150 static DEFINE_SPINLOCK(ptype_lock);
151 static struct list_head ptype_base[16] __read_mostly;	/* 16 way hashed list */
152 static struct list_head ptype_all __read_mostly;	/* Taps */
153 
154 #ifdef CONFIG_NET_DMA
155 struct net_dma {
156 	struct dma_client client;
157 	spinlock_t lock;
158 	cpumask_t channel_mask;
159 	struct dma_chan *channels[NR_CPUS];
160 };
161 
162 static enum dma_state_client
163 netdev_dma_event(struct dma_client *client, struct dma_chan *chan,
164 	enum dma_state state);
165 
166 static struct net_dma net_dma = {
167 	.client = {
168 		.event_callback = netdev_dma_event,
169 	},
170 };
171 #endif
172 
173 /*
174  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
175  * semaphore.
176  *
177  * Pure readers hold dev_base_lock for reading.
178  *
179  * Writers must hold the rtnl semaphore while they loop through the
180  * dev_base_head list, and hold dev_base_lock for writing when they do the
181  * actual updates.  This allows pure readers to access the list even
182  * while a writer is preparing to update it.
183  *
184  * To put it another way, dev_base_lock is held for writing only to
185  * protect against pure readers; the rtnl semaphore provides the
186  * protection against other writers.
187  *
188  * See, for example usages, register_netdevice() and
189  * unregister_netdevice(), which must be called with the rtnl
190  * semaphore held.
191  */
192 LIST_HEAD(dev_base_head);
193 DEFINE_RWLOCK(dev_base_lock);
194 
195 EXPORT_SYMBOL(dev_base_head);
196 EXPORT_SYMBOL(dev_base_lock);
197 
198 #define NETDEV_HASHBITS	8
199 static struct hlist_head dev_name_head[1<<NETDEV_HASHBITS];
200 static struct hlist_head dev_index_head[1<<NETDEV_HASHBITS];
201 
202 static inline struct hlist_head *dev_name_hash(const char *name)
203 {
204 	unsigned hash = full_name_hash(name, strnlen(name, IFNAMSIZ));
205 	return &dev_name_head[hash & ((1<<NETDEV_HASHBITS)-1)];
206 }
207 
208 static inline struct hlist_head *dev_index_hash(int ifindex)
209 {
210 	return &dev_index_head[ifindex & ((1<<NETDEV_HASHBITS)-1)];
211 }
212 
213 /*
214  *	Our notifier list
215  */
216 
217 static RAW_NOTIFIER_HEAD(netdev_chain);
218 
219 /*
220  *	Device drivers call our routines to queue packets here. We empty the
221  *	queue in the local softnet handler.
222  */
223 DEFINE_PER_CPU(struct softnet_data, softnet_data) = { NULL };
224 
225 #ifdef CONFIG_SYSFS
226 extern int netdev_sysfs_init(void);
227 extern int netdev_register_sysfs(struct net_device *);
228 extern void netdev_unregister_sysfs(struct net_device *);
229 #else
230 #define netdev_sysfs_init()	 	(0)
231 #define netdev_register_sysfs(dev)	(0)
232 #define	netdev_unregister_sysfs(dev)	do { } while(0)
233 #endif
234 
235 #ifdef CONFIG_DEBUG_LOCK_ALLOC
236 /*
237  * register_netdevice() inits dev->_xmit_lock and sets lockdep class
238  * according to dev->type
239  */
240 static const unsigned short netdev_lock_type[] =
241 	{ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
242 	 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
243 	 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
244 	 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
245 	 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
246 	 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
247 	 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
248 	 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
249 	 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
250 	 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
251 	 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
252 	 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
253 	 ARPHRD_FCFABRIC, ARPHRD_IEEE802_TR, ARPHRD_IEEE80211,
254 	 ARPHRD_IEEE80211_PRISM, ARPHRD_IEEE80211_RADIOTAP, ARPHRD_VOID,
255 	 ARPHRD_NONE};
256 
257 static const char *netdev_lock_name[] =
258 	{"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
259 	 "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
260 	 "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
261 	 "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
262 	 "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
263 	 "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
264 	 "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
265 	 "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
266 	 "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
267 	 "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
268 	 "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
269 	 "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
270 	 "_xmit_FCFABRIC", "_xmit_IEEE802_TR", "_xmit_IEEE80211",
271 	 "_xmit_IEEE80211_PRISM", "_xmit_IEEE80211_RADIOTAP", "_xmit_VOID",
272 	 "_xmit_NONE"};
273 
274 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
275 
276 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
277 {
278 	int i;
279 
280 	for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
281 		if (netdev_lock_type[i] == dev_type)
282 			return i;
283 	/* the last key is used by default */
284 	return ARRAY_SIZE(netdev_lock_type) - 1;
285 }
286 
287 static inline void netdev_set_lockdep_class(spinlock_t *lock,
288 					    unsigned short dev_type)
289 {
290 	int i;
291 
292 	i = netdev_lock_pos(dev_type);
293 	lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
294 				   netdev_lock_name[i]);
295 }
296 #else
297 static inline void netdev_set_lockdep_class(spinlock_t *lock,
298 					    unsigned short dev_type)
299 {
300 }
301 #endif
302 
303 /*******************************************************************************
304 
305 		Protocol management and registration routines
306 
307 *******************************************************************************/
308 
309 /*
310  *	Add a protocol ID to the list. Now that the input handler is
311  *	smarter we can dispense with all the messy stuff that used to be
312  *	here.
313  *
314  *	BEWARE!!! Protocol handlers, mangling input packets,
315  *	MUST BE last in hash buckets and checking protocol handlers
316  *	MUST start from promiscuous ptype_all chain in net_bh.
317  *	It is true now, do not change it.
318  *	Explanation follows: if protocol handler, mangling packet, will
319  *	be the first on list, it is not able to sense, that packet
320  *	is cloned and should be copied-on-write, so that it will
321  *	change it and subsequent readers will get broken packet.
322  *							--ANK (980803)
323  */
324 
325 /**
326  *	dev_add_pack - add packet handler
327  *	@pt: packet type declaration
328  *
329  *	Add a protocol handler to the networking stack. The passed &packet_type
330  *	is linked into kernel lists and may not be freed until it has been
331  *	removed from the kernel lists.
332  *
333  *	This call does not sleep therefore it can not
334  *	guarantee all CPU's that are in middle of receiving packets
335  *	will see the new packet type (until the next received packet).
336  */
337 
338 void dev_add_pack(struct packet_type *pt)
339 {
340 	int hash;
341 
342 	spin_lock_bh(&ptype_lock);
343 	if (pt->type == htons(ETH_P_ALL))
344 		list_add_rcu(&pt->list, &ptype_all);
345 	else {
346 		hash = ntohs(pt->type) & 15;
347 		list_add_rcu(&pt->list, &ptype_base[hash]);
348 	}
349 	spin_unlock_bh(&ptype_lock);
350 }
351 
352 /**
353  *	__dev_remove_pack	 - remove packet handler
354  *	@pt: packet type declaration
355  *
356  *	Remove a protocol handler that was previously added to the kernel
357  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
358  *	from the kernel lists and can be freed or reused once this function
359  *	returns.
360  *
361  *      The packet type might still be in use by receivers
362  *	and must not be freed until after all the CPU's have gone
363  *	through a quiescent state.
364  */
365 void __dev_remove_pack(struct packet_type *pt)
366 {
367 	struct list_head *head;
368 	struct packet_type *pt1;
369 
370 	spin_lock_bh(&ptype_lock);
371 
372 	if (pt->type == htons(ETH_P_ALL))
373 		head = &ptype_all;
374 	else
375 		head = &ptype_base[ntohs(pt->type) & 15];
376 
377 	list_for_each_entry(pt1, head, list) {
378 		if (pt == pt1) {
379 			list_del_rcu(&pt->list);
380 			goto out;
381 		}
382 	}
383 
384 	printk(KERN_WARNING "dev_remove_pack: %p not found.\n", pt);
385 out:
386 	spin_unlock_bh(&ptype_lock);
387 }
388 /**
389  *	dev_remove_pack	 - remove packet handler
390  *	@pt: packet type declaration
391  *
392  *	Remove a protocol handler that was previously added to the kernel
393  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
394  *	from the kernel lists and can be freed or reused once this function
395  *	returns.
396  *
397  *	This call sleeps to guarantee that no CPU is looking at the packet
398  *	type after return.
399  */
400 void dev_remove_pack(struct packet_type *pt)
401 {
402 	__dev_remove_pack(pt);
403 
404 	synchronize_net();
405 }
406 
407 /******************************************************************************
408 
409 		      Device Boot-time Settings Routines
410 
411 *******************************************************************************/
412 
413 /* Boot time configuration table */
414 static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX];
415 
416 /**
417  *	netdev_boot_setup_add	- add new setup entry
418  *	@name: name of the device
419  *	@map: configured settings for the device
420  *
421  *	Adds new setup entry to the dev_boot_setup list.  The function
422  *	returns 0 on error and 1 on success.  This is a generic routine to
423  *	all netdevices.
424  */
425 static int netdev_boot_setup_add(char *name, struct ifmap *map)
426 {
427 	struct netdev_boot_setup *s;
428 	int i;
429 
430 	s = dev_boot_setup;
431 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
432 		if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
433 			memset(s[i].name, 0, sizeof(s[i].name));
434 			strcpy(s[i].name, name);
435 			memcpy(&s[i].map, map, sizeof(s[i].map));
436 			break;
437 		}
438 	}
439 
440 	return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1;
441 }
442 
443 /**
444  *	netdev_boot_setup_check	- check boot time settings
445  *	@dev: the netdevice
446  *
447  * 	Check boot time settings for the device.
448  *	The found settings are set for the device to be used
449  *	later in the device probing.
450  *	Returns 0 if no settings found, 1 if they are.
451  */
452 int netdev_boot_setup_check(struct net_device *dev)
453 {
454 	struct netdev_boot_setup *s = dev_boot_setup;
455 	int i;
456 
457 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
458 		if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
459 		    !strncmp(dev->name, s[i].name, strlen(s[i].name))) {
460 			dev->irq 	= s[i].map.irq;
461 			dev->base_addr 	= s[i].map.base_addr;
462 			dev->mem_start 	= s[i].map.mem_start;
463 			dev->mem_end 	= s[i].map.mem_end;
464 			return 1;
465 		}
466 	}
467 	return 0;
468 }
469 
470 
471 /**
472  *	netdev_boot_base	- get address from boot time settings
473  *	@prefix: prefix for network device
474  *	@unit: id for network device
475  *
476  * 	Check boot time settings for the base address of device.
477  *	The found settings are set for the device to be used
478  *	later in the device probing.
479  *	Returns 0 if no settings found.
480  */
481 unsigned long netdev_boot_base(const char *prefix, int unit)
482 {
483 	const struct netdev_boot_setup *s = dev_boot_setup;
484 	char name[IFNAMSIZ];
485 	int i;
486 
487 	sprintf(name, "%s%d", prefix, unit);
488 
489 	/*
490 	 * If device already registered then return base of 1
491 	 * to indicate not to probe for this interface
492 	 */
493 	if (__dev_get_by_name(name))
494 		return 1;
495 
496 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++)
497 		if (!strcmp(name, s[i].name))
498 			return s[i].map.base_addr;
499 	return 0;
500 }
501 
502 /*
503  * Saves at boot time configured settings for any netdevice.
504  */
505 int __init netdev_boot_setup(char *str)
506 {
507 	int ints[5];
508 	struct ifmap map;
509 
510 	str = get_options(str, ARRAY_SIZE(ints), ints);
511 	if (!str || !*str)
512 		return 0;
513 
514 	/* Save settings */
515 	memset(&map, 0, sizeof(map));
516 	if (ints[0] > 0)
517 		map.irq = ints[1];
518 	if (ints[0] > 1)
519 		map.base_addr = ints[2];
520 	if (ints[0] > 2)
521 		map.mem_start = ints[3];
522 	if (ints[0] > 3)
523 		map.mem_end = ints[4];
524 
525 	/* Add new entry to the list */
526 	return netdev_boot_setup_add(str, &map);
527 }
528 
529 __setup("netdev=", netdev_boot_setup);
530 
531 /*******************************************************************************
532 
533 			    Device Interface Subroutines
534 
535 *******************************************************************************/
536 
537 /**
538  *	__dev_get_by_name	- find a device by its name
539  *	@name: name to find
540  *
541  *	Find an interface by name. Must be called under RTNL semaphore
542  *	or @dev_base_lock. If the name is found a pointer to the device
543  *	is returned. If the name is not found then %NULL is returned. The
544  *	reference counters are not incremented so the caller must be
545  *	careful with locks.
546  */
547 
548 struct net_device *__dev_get_by_name(const char *name)
549 {
550 	struct hlist_node *p;
551 
552 	hlist_for_each(p, dev_name_hash(name)) {
553 		struct net_device *dev
554 			= hlist_entry(p, struct net_device, name_hlist);
555 		if (!strncmp(dev->name, name, IFNAMSIZ))
556 			return dev;
557 	}
558 	return NULL;
559 }
560 
561 /**
562  *	dev_get_by_name		- find a device by its name
563  *	@name: name to find
564  *
565  *	Find an interface by name. This can be called from any
566  *	context and does its own locking. The returned handle has
567  *	the usage count incremented and the caller must use dev_put() to
568  *	release it when it is no longer needed. %NULL is returned if no
569  *	matching device is found.
570  */
571 
572 struct net_device *dev_get_by_name(const char *name)
573 {
574 	struct net_device *dev;
575 
576 	read_lock(&dev_base_lock);
577 	dev = __dev_get_by_name(name);
578 	if (dev)
579 		dev_hold(dev);
580 	read_unlock(&dev_base_lock);
581 	return dev;
582 }
583 
584 /**
585  *	__dev_get_by_index - find a device by its ifindex
586  *	@ifindex: index of device
587  *
588  *	Search for an interface by index. Returns %NULL if the device
589  *	is not found or a pointer to the device. The device has not
590  *	had its reference counter increased so the caller must be careful
591  *	about locking. The caller must hold either the RTNL semaphore
592  *	or @dev_base_lock.
593  */
594 
595 struct net_device *__dev_get_by_index(int ifindex)
596 {
597 	struct hlist_node *p;
598 
599 	hlist_for_each(p, dev_index_hash(ifindex)) {
600 		struct net_device *dev
601 			= hlist_entry(p, struct net_device, index_hlist);
602 		if (dev->ifindex == ifindex)
603 			return dev;
604 	}
605 	return NULL;
606 }
607 
608 
609 /**
610  *	dev_get_by_index - find a device by its ifindex
611  *	@ifindex: index of device
612  *
613  *	Search for an interface by index. Returns NULL if the device
614  *	is not found or a pointer to the device. The device returned has
615  *	had a reference added and the pointer is safe until the user calls
616  *	dev_put to indicate they have finished with it.
617  */
618 
619 struct net_device *dev_get_by_index(int ifindex)
620 {
621 	struct net_device *dev;
622 
623 	read_lock(&dev_base_lock);
624 	dev = __dev_get_by_index(ifindex);
625 	if (dev)
626 		dev_hold(dev);
627 	read_unlock(&dev_base_lock);
628 	return dev;
629 }
630 
631 /**
632  *	dev_getbyhwaddr - find a device by its hardware address
633  *	@type: media type of device
634  *	@ha: hardware address
635  *
636  *	Search for an interface by MAC address. Returns NULL if the device
637  *	is not found or a pointer to the device. The caller must hold the
638  *	rtnl semaphore. The returned device has not had its ref count increased
639  *	and the caller must therefore be careful about locking
640  *
641  *	BUGS:
642  *	If the API was consistent this would be __dev_get_by_hwaddr
643  */
644 
645 struct net_device *dev_getbyhwaddr(unsigned short type, char *ha)
646 {
647 	struct net_device *dev;
648 
649 	ASSERT_RTNL();
650 
651 	for_each_netdev(dev)
652 		if (dev->type == type &&
653 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
654 			return dev;
655 
656 	return NULL;
657 }
658 
659 EXPORT_SYMBOL(dev_getbyhwaddr);
660 
661 struct net_device *__dev_getfirstbyhwtype(unsigned short type)
662 {
663 	struct net_device *dev;
664 
665 	ASSERT_RTNL();
666 	for_each_netdev(dev)
667 		if (dev->type == type)
668 			return dev;
669 
670 	return NULL;
671 }
672 
673 EXPORT_SYMBOL(__dev_getfirstbyhwtype);
674 
675 struct net_device *dev_getfirstbyhwtype(unsigned short type)
676 {
677 	struct net_device *dev;
678 
679 	rtnl_lock();
680 	dev = __dev_getfirstbyhwtype(type);
681 	if (dev)
682 		dev_hold(dev);
683 	rtnl_unlock();
684 	return dev;
685 }
686 
687 EXPORT_SYMBOL(dev_getfirstbyhwtype);
688 
689 /**
690  *	dev_get_by_flags - find any device with given flags
691  *	@if_flags: IFF_* values
692  *	@mask: bitmask of bits in if_flags to check
693  *
694  *	Search for any interface with the given flags. Returns NULL if a device
695  *	is not found or a pointer to the device. The device returned has
696  *	had a reference added and the pointer is safe until the user calls
697  *	dev_put to indicate they have finished with it.
698  */
699 
700 struct net_device * dev_get_by_flags(unsigned short if_flags, unsigned short mask)
701 {
702 	struct net_device *dev, *ret;
703 
704 	ret = NULL;
705 	read_lock(&dev_base_lock);
706 	for_each_netdev(dev) {
707 		if (((dev->flags ^ if_flags) & mask) == 0) {
708 			dev_hold(dev);
709 			ret = dev;
710 			break;
711 		}
712 	}
713 	read_unlock(&dev_base_lock);
714 	return ret;
715 }
716 
717 /**
718  *	dev_valid_name - check if name is okay for network device
719  *	@name: name string
720  *
721  *	Network device names need to be valid file names to
722  *	to allow sysfs to work.  We also disallow any kind of
723  *	whitespace.
724  */
725 int dev_valid_name(const char *name)
726 {
727 	if (*name == '\0')
728 		return 0;
729 	if (strlen(name) >= IFNAMSIZ)
730 		return 0;
731 	if (!strcmp(name, ".") || !strcmp(name, ".."))
732 		return 0;
733 
734 	while (*name) {
735 		if (*name == '/' || isspace(*name))
736 			return 0;
737 		name++;
738 	}
739 	return 1;
740 }
741 
742 /**
743  *	dev_alloc_name - allocate a name for a device
744  *	@dev: device
745  *	@name: name format string
746  *
747  *	Passed a format string - eg "lt%d" it will try and find a suitable
748  *	id. It scans list of devices to build up a free map, then chooses
749  *	the first empty slot. The caller must hold the dev_base or rtnl lock
750  *	while allocating the name and adding the device in order to avoid
751  *	duplicates.
752  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
753  *	Returns the number of the unit assigned or a negative errno code.
754  */
755 
756 int dev_alloc_name(struct net_device *dev, const char *name)
757 {
758 	int i = 0;
759 	char buf[IFNAMSIZ];
760 	const char *p;
761 	const int max_netdevices = 8*PAGE_SIZE;
762 	long *inuse;
763 	struct net_device *d;
764 
765 	p = strnchr(name, IFNAMSIZ-1, '%');
766 	if (p) {
767 		/*
768 		 * Verify the string as this thing may have come from
769 		 * the user.  There must be either one "%d" and no other "%"
770 		 * characters.
771 		 */
772 		if (p[1] != 'd' || strchr(p + 2, '%'))
773 			return -EINVAL;
774 
775 		/* Use one page as a bit array of possible slots */
776 		inuse = (long *) get_zeroed_page(GFP_ATOMIC);
777 		if (!inuse)
778 			return -ENOMEM;
779 
780 		for_each_netdev(d) {
781 			if (!sscanf(d->name, name, &i))
782 				continue;
783 			if (i < 0 || i >= max_netdevices)
784 				continue;
785 
786 			/*  avoid cases where sscanf is not exact inverse of printf */
787 			snprintf(buf, sizeof(buf), name, i);
788 			if (!strncmp(buf, d->name, IFNAMSIZ))
789 				set_bit(i, inuse);
790 		}
791 
792 		i = find_first_zero_bit(inuse, max_netdevices);
793 		free_page((unsigned long) inuse);
794 	}
795 
796 	snprintf(buf, sizeof(buf), name, i);
797 	if (!__dev_get_by_name(buf)) {
798 		strlcpy(dev->name, buf, IFNAMSIZ);
799 		return i;
800 	}
801 
802 	/* It is possible to run out of possible slots
803 	 * when the name is long and there isn't enough space left
804 	 * for the digits, or if all bits are used.
805 	 */
806 	return -ENFILE;
807 }
808 
809 
810 /**
811  *	dev_change_name - change name of a device
812  *	@dev: device
813  *	@newname: name (or format string) must be at least IFNAMSIZ
814  *
815  *	Change name of a device, can pass format strings "eth%d".
816  *	for wildcarding.
817  */
818 int dev_change_name(struct net_device *dev, char *newname)
819 {
820 	char oldname[IFNAMSIZ];
821 	int err = 0;
822 	int ret;
823 
824 	ASSERT_RTNL();
825 
826 	if (dev->flags & IFF_UP)
827 		return -EBUSY;
828 
829 	if (!dev_valid_name(newname))
830 		return -EINVAL;
831 
832 	memcpy(oldname, dev->name, IFNAMSIZ);
833 
834 	if (strchr(newname, '%')) {
835 		err = dev_alloc_name(dev, newname);
836 		if (err < 0)
837 			return err;
838 		strcpy(newname, dev->name);
839 	}
840 	else if (__dev_get_by_name(newname))
841 		return -EEXIST;
842 	else
843 		strlcpy(dev->name, newname, IFNAMSIZ);
844 
845 rollback:
846 	device_rename(&dev->dev, dev->name);
847 
848 	write_lock_bh(&dev_base_lock);
849 	hlist_del(&dev->name_hlist);
850 	hlist_add_head(&dev->name_hlist, dev_name_hash(dev->name));
851 	write_unlock_bh(&dev_base_lock);
852 
853 	ret = raw_notifier_call_chain(&netdev_chain, NETDEV_CHANGENAME, dev);
854 	ret = notifier_to_errno(ret);
855 
856 	if (ret) {
857 		if (err) {
858 			printk(KERN_ERR
859 			       "%s: name change rollback failed: %d.\n",
860 			       dev->name, ret);
861 		} else {
862 			err = ret;
863 			memcpy(dev->name, oldname, IFNAMSIZ);
864 			goto rollback;
865 		}
866 	}
867 
868 	return err;
869 }
870 
871 /**
872  *	netdev_features_change - device changes features
873  *	@dev: device to cause notification
874  *
875  *	Called to indicate a device has changed features.
876  */
877 void netdev_features_change(struct net_device *dev)
878 {
879 	raw_notifier_call_chain(&netdev_chain, NETDEV_FEAT_CHANGE, dev);
880 }
881 EXPORT_SYMBOL(netdev_features_change);
882 
883 /**
884  *	netdev_state_change - device changes state
885  *	@dev: device to cause notification
886  *
887  *	Called to indicate a device has changed state. This function calls
888  *	the notifier chains for netdev_chain and sends a NEWLINK message
889  *	to the routing socket.
890  */
891 void netdev_state_change(struct net_device *dev)
892 {
893 	if (dev->flags & IFF_UP) {
894 		raw_notifier_call_chain(&netdev_chain,
895 				NETDEV_CHANGE, dev);
896 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
897 	}
898 }
899 
900 /**
901  *	dev_load 	- load a network module
902  *	@name: name of interface
903  *
904  *	If a network interface is not present and the process has suitable
905  *	privileges this function loads the module. If module loading is not
906  *	available in this kernel then it becomes a nop.
907  */
908 
909 void dev_load(const char *name)
910 {
911 	struct net_device *dev;
912 
913 	read_lock(&dev_base_lock);
914 	dev = __dev_get_by_name(name);
915 	read_unlock(&dev_base_lock);
916 
917 	if (!dev && capable(CAP_SYS_MODULE))
918 		request_module("%s", name);
919 }
920 
921 static int default_rebuild_header(struct sk_buff *skb)
922 {
923 	printk(KERN_DEBUG "%s: default_rebuild_header called -- BUG!\n",
924 	       skb->dev ? skb->dev->name : "NULL!!!");
925 	kfree_skb(skb);
926 	return 1;
927 }
928 
929 /**
930  *	dev_open	- prepare an interface for use.
931  *	@dev:	device to open
932  *
933  *	Takes a device from down to up state. The device's private open
934  *	function is invoked and then the multicast lists are loaded. Finally
935  *	the device is moved into the up state and a %NETDEV_UP message is
936  *	sent to the netdev notifier chain.
937  *
938  *	Calling this function on an active interface is a nop. On a failure
939  *	a negative errno code is returned.
940  */
941 int dev_open(struct net_device *dev)
942 {
943 	int ret = 0;
944 
945 	/*
946 	 *	Is it already up?
947 	 */
948 
949 	if (dev->flags & IFF_UP)
950 		return 0;
951 
952 	/*
953 	 *	Is it even present?
954 	 */
955 	if (!netif_device_present(dev))
956 		return -ENODEV;
957 
958 	/*
959 	 *	Call device private open method
960 	 */
961 	set_bit(__LINK_STATE_START, &dev->state);
962 	if (dev->open) {
963 		ret = dev->open(dev);
964 		if (ret)
965 			clear_bit(__LINK_STATE_START, &dev->state);
966 	}
967 
968 	/*
969 	 *	If it went open OK then:
970 	 */
971 
972 	if (!ret) {
973 		/*
974 		 *	Set the flags.
975 		 */
976 		dev->flags |= IFF_UP;
977 
978 		/*
979 		 *	Initialize multicasting status
980 		 */
981 		dev_set_rx_mode(dev);
982 
983 		/*
984 		 *	Wakeup transmit queue engine
985 		 */
986 		dev_activate(dev);
987 
988 		/*
989 		 *	... and announce new interface.
990 		 */
991 		raw_notifier_call_chain(&netdev_chain, NETDEV_UP, dev);
992 	}
993 	return ret;
994 }
995 
996 /**
997  *	dev_close - shutdown an interface.
998  *	@dev: device to shutdown
999  *
1000  *	This function moves an active device into down state. A
1001  *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1002  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1003  *	chain.
1004  */
1005 int dev_close(struct net_device *dev)
1006 {
1007 	if (!(dev->flags & IFF_UP))
1008 		return 0;
1009 
1010 	/*
1011 	 *	Tell people we are going down, so that they can
1012 	 *	prepare to death, when device is still operating.
1013 	 */
1014 	raw_notifier_call_chain(&netdev_chain, NETDEV_GOING_DOWN, dev);
1015 
1016 	dev_deactivate(dev);
1017 
1018 	clear_bit(__LINK_STATE_START, &dev->state);
1019 
1020 	/* Synchronize to scheduled poll. We cannot touch poll list,
1021 	 * it can be even on different cpu. So just clear netif_running(),
1022 	 * and wait when poll really will happen. Actually, the best place
1023 	 * for this is inside dev->stop() after device stopped its irq
1024 	 * engine, but this requires more changes in devices. */
1025 
1026 	smp_mb__after_clear_bit(); /* Commit netif_running(). */
1027 	while (test_bit(__LINK_STATE_RX_SCHED, &dev->state)) {
1028 		/* No hurry. */
1029 		msleep(1);
1030 	}
1031 
1032 	/*
1033 	 *	Call the device specific close. This cannot fail.
1034 	 *	Only if device is UP
1035 	 *
1036 	 *	We allow it to be called even after a DETACH hot-plug
1037 	 *	event.
1038 	 */
1039 	if (dev->stop)
1040 		dev->stop(dev);
1041 
1042 	/*
1043 	 *	Device is now down.
1044 	 */
1045 
1046 	dev->flags &= ~IFF_UP;
1047 
1048 	/*
1049 	 * Tell people we are down
1050 	 */
1051 	raw_notifier_call_chain(&netdev_chain, NETDEV_DOWN, dev);
1052 
1053 	return 0;
1054 }
1055 
1056 
1057 /*
1058  *	Device change register/unregister. These are not inline or static
1059  *	as we export them to the world.
1060  */
1061 
1062 /**
1063  *	register_netdevice_notifier - register a network notifier block
1064  *	@nb: notifier
1065  *
1066  *	Register a notifier to be called when network device events occur.
1067  *	The notifier passed is linked into the kernel structures and must
1068  *	not be reused until it has been unregistered. A negative errno code
1069  *	is returned on a failure.
1070  *
1071  * 	When registered all registration and up events are replayed
1072  *	to the new notifier to allow device to have a race free
1073  *	view of the network device list.
1074  */
1075 
1076 int register_netdevice_notifier(struct notifier_block *nb)
1077 {
1078 	struct net_device *dev;
1079 	struct net_device *last;
1080 	int err;
1081 
1082 	rtnl_lock();
1083 	err = raw_notifier_chain_register(&netdev_chain, nb);
1084 	if (err)
1085 		goto unlock;
1086 
1087 	for_each_netdev(dev) {
1088 		err = nb->notifier_call(nb, NETDEV_REGISTER, dev);
1089 		err = notifier_to_errno(err);
1090 		if (err)
1091 			goto rollback;
1092 
1093 		if (!(dev->flags & IFF_UP))
1094 			continue;
1095 
1096 		nb->notifier_call(nb, NETDEV_UP, dev);
1097 	}
1098 
1099 unlock:
1100 	rtnl_unlock();
1101 	return err;
1102 
1103 rollback:
1104 	last = dev;
1105 	for_each_netdev(dev) {
1106 		if (dev == last)
1107 			break;
1108 
1109 		if (dev->flags & IFF_UP) {
1110 			nb->notifier_call(nb, NETDEV_GOING_DOWN, dev);
1111 			nb->notifier_call(nb, NETDEV_DOWN, dev);
1112 		}
1113 		nb->notifier_call(nb, NETDEV_UNREGISTER, dev);
1114 	}
1115 	goto unlock;
1116 }
1117 
1118 /**
1119  *	unregister_netdevice_notifier - unregister a network notifier block
1120  *	@nb: notifier
1121  *
1122  *	Unregister a notifier previously registered by
1123  *	register_netdevice_notifier(). The notifier is unlinked into the
1124  *	kernel structures and may then be reused. A negative errno code
1125  *	is returned on a failure.
1126  */
1127 
1128 int unregister_netdevice_notifier(struct notifier_block *nb)
1129 {
1130 	int err;
1131 
1132 	rtnl_lock();
1133 	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1134 	rtnl_unlock();
1135 	return err;
1136 }
1137 
1138 /**
1139  *	call_netdevice_notifiers - call all network notifier blocks
1140  *      @val: value passed unmodified to notifier function
1141  *      @v:   pointer passed unmodified to notifier function
1142  *
1143  *	Call all network notifier blocks.  Parameters and return value
1144  *	are as for raw_notifier_call_chain().
1145  */
1146 
1147 int call_netdevice_notifiers(unsigned long val, void *v)
1148 {
1149 	return raw_notifier_call_chain(&netdev_chain, val, v);
1150 }
1151 
1152 /* When > 0 there are consumers of rx skb time stamps */
1153 static atomic_t netstamp_needed = ATOMIC_INIT(0);
1154 
1155 void net_enable_timestamp(void)
1156 {
1157 	atomic_inc(&netstamp_needed);
1158 }
1159 
1160 void net_disable_timestamp(void)
1161 {
1162 	atomic_dec(&netstamp_needed);
1163 }
1164 
1165 static inline void net_timestamp(struct sk_buff *skb)
1166 {
1167 	if (atomic_read(&netstamp_needed))
1168 		__net_timestamp(skb);
1169 	else
1170 		skb->tstamp.tv64 = 0;
1171 }
1172 
1173 /*
1174  *	Support routine. Sends outgoing frames to any network
1175  *	taps currently in use.
1176  */
1177 
1178 static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
1179 {
1180 	struct packet_type *ptype;
1181 
1182 	net_timestamp(skb);
1183 
1184 	rcu_read_lock();
1185 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
1186 		/* Never send packets back to the socket
1187 		 * they originated from - MvS (miquels@drinkel.ow.org)
1188 		 */
1189 		if ((ptype->dev == dev || !ptype->dev) &&
1190 		    (ptype->af_packet_priv == NULL ||
1191 		     (struct sock *)ptype->af_packet_priv != skb->sk)) {
1192 			struct sk_buff *skb2= skb_clone(skb, GFP_ATOMIC);
1193 			if (!skb2)
1194 				break;
1195 
1196 			/* skb->nh should be correctly
1197 			   set by sender, so that the second statement is
1198 			   just protection against buggy protocols.
1199 			 */
1200 			skb_reset_mac_header(skb2);
1201 
1202 			if (skb_network_header(skb2) < skb2->data ||
1203 			    skb2->network_header > skb2->tail) {
1204 				if (net_ratelimit())
1205 					printk(KERN_CRIT "protocol %04x is "
1206 					       "buggy, dev %s\n",
1207 					       skb2->protocol, dev->name);
1208 				skb_reset_network_header(skb2);
1209 			}
1210 
1211 			skb2->transport_header = skb2->network_header;
1212 			skb2->pkt_type = PACKET_OUTGOING;
1213 			ptype->func(skb2, skb->dev, ptype, skb->dev);
1214 		}
1215 	}
1216 	rcu_read_unlock();
1217 }
1218 
1219 
1220 void __netif_schedule(struct net_device *dev)
1221 {
1222 	if (!test_and_set_bit(__LINK_STATE_SCHED, &dev->state)) {
1223 		unsigned long flags;
1224 		struct softnet_data *sd;
1225 
1226 		local_irq_save(flags);
1227 		sd = &__get_cpu_var(softnet_data);
1228 		dev->next_sched = sd->output_queue;
1229 		sd->output_queue = dev;
1230 		raise_softirq_irqoff(NET_TX_SOFTIRQ);
1231 		local_irq_restore(flags);
1232 	}
1233 }
1234 EXPORT_SYMBOL(__netif_schedule);
1235 
1236 void __netif_rx_schedule(struct net_device *dev)
1237 {
1238 	unsigned long flags;
1239 
1240 	local_irq_save(flags);
1241 	dev_hold(dev);
1242 	list_add_tail(&dev->poll_list, &__get_cpu_var(softnet_data).poll_list);
1243 	if (dev->quota < 0)
1244 		dev->quota += dev->weight;
1245 	else
1246 		dev->quota = dev->weight;
1247 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
1248 	local_irq_restore(flags);
1249 }
1250 EXPORT_SYMBOL(__netif_rx_schedule);
1251 
1252 void dev_kfree_skb_any(struct sk_buff *skb)
1253 {
1254 	if (in_irq() || irqs_disabled())
1255 		dev_kfree_skb_irq(skb);
1256 	else
1257 		dev_kfree_skb(skb);
1258 }
1259 EXPORT_SYMBOL(dev_kfree_skb_any);
1260 
1261 
1262 /* Hot-plugging. */
1263 void netif_device_detach(struct net_device *dev)
1264 {
1265 	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
1266 	    netif_running(dev)) {
1267 		netif_stop_queue(dev);
1268 	}
1269 }
1270 EXPORT_SYMBOL(netif_device_detach);
1271 
1272 void netif_device_attach(struct net_device *dev)
1273 {
1274 	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
1275 	    netif_running(dev)) {
1276 		netif_wake_queue(dev);
1277 		__netdev_watchdog_up(dev);
1278 	}
1279 }
1280 EXPORT_SYMBOL(netif_device_attach);
1281 
1282 
1283 /*
1284  * Invalidate hardware checksum when packet is to be mangled, and
1285  * complete checksum manually on outgoing path.
1286  */
1287 int skb_checksum_help(struct sk_buff *skb)
1288 {
1289 	__wsum csum;
1290 	int ret = 0, offset;
1291 
1292 	if (skb->ip_summed == CHECKSUM_COMPLETE)
1293 		goto out_set_summed;
1294 
1295 	if (unlikely(skb_shinfo(skb)->gso_size)) {
1296 		/* Let GSO fix up the checksum. */
1297 		goto out_set_summed;
1298 	}
1299 
1300 	if (skb_cloned(skb)) {
1301 		ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
1302 		if (ret)
1303 			goto out;
1304 	}
1305 
1306 	offset = skb->csum_start - skb_headroom(skb);
1307 	BUG_ON(offset > (int)skb->len);
1308 	csum = skb_checksum(skb, offset, skb->len-offset, 0);
1309 
1310 	offset = skb_headlen(skb) - offset;
1311 	BUG_ON(offset <= 0);
1312 	BUG_ON(skb->csum_offset + 2 > offset);
1313 
1314 	*(__sum16 *)(skb->head + skb->csum_start + skb->csum_offset) =
1315 		csum_fold(csum);
1316 out_set_summed:
1317 	skb->ip_summed = CHECKSUM_NONE;
1318 out:
1319 	return ret;
1320 }
1321 
1322 /**
1323  *	skb_gso_segment - Perform segmentation on skb.
1324  *	@skb: buffer to segment
1325  *	@features: features for the output path (see dev->features)
1326  *
1327  *	This function segments the given skb and returns a list of segments.
1328  *
1329  *	It may return NULL if the skb requires no segmentation.  This is
1330  *	only possible when GSO is used for verifying header integrity.
1331  */
1332 struct sk_buff *skb_gso_segment(struct sk_buff *skb, int features)
1333 {
1334 	struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
1335 	struct packet_type *ptype;
1336 	__be16 type = skb->protocol;
1337 	int err;
1338 
1339 	BUG_ON(skb_shinfo(skb)->frag_list);
1340 
1341 	skb_reset_mac_header(skb);
1342 	skb->mac_len = skb->network_header - skb->mac_header;
1343 	__skb_pull(skb, skb->mac_len);
1344 
1345 	if (WARN_ON(skb->ip_summed != CHECKSUM_PARTIAL)) {
1346 		if (skb_header_cloned(skb) &&
1347 		    (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
1348 			return ERR_PTR(err);
1349 	}
1350 
1351 	rcu_read_lock();
1352 	list_for_each_entry_rcu(ptype, &ptype_base[ntohs(type) & 15], list) {
1353 		if (ptype->type == type && !ptype->dev && ptype->gso_segment) {
1354 			if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
1355 				err = ptype->gso_send_check(skb);
1356 				segs = ERR_PTR(err);
1357 				if (err || skb_gso_ok(skb, features))
1358 					break;
1359 				__skb_push(skb, (skb->data -
1360 						 skb_network_header(skb)));
1361 			}
1362 			segs = ptype->gso_segment(skb, features);
1363 			break;
1364 		}
1365 	}
1366 	rcu_read_unlock();
1367 
1368 	__skb_push(skb, skb->data - skb_mac_header(skb));
1369 
1370 	return segs;
1371 }
1372 
1373 EXPORT_SYMBOL(skb_gso_segment);
1374 
1375 /* Take action when hardware reception checksum errors are detected. */
1376 #ifdef CONFIG_BUG
1377 void netdev_rx_csum_fault(struct net_device *dev)
1378 {
1379 	if (net_ratelimit()) {
1380 		printk(KERN_ERR "%s: hw csum failure.\n",
1381 			dev ? dev->name : "<unknown>");
1382 		dump_stack();
1383 	}
1384 }
1385 EXPORT_SYMBOL(netdev_rx_csum_fault);
1386 #endif
1387 
1388 /* Actually, we should eliminate this check as soon as we know, that:
1389  * 1. IOMMU is present and allows to map all the memory.
1390  * 2. No high memory really exists on this machine.
1391  */
1392 
1393 static inline int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
1394 {
1395 #ifdef CONFIG_HIGHMEM
1396 	int i;
1397 
1398 	if (dev->features & NETIF_F_HIGHDMA)
1399 		return 0;
1400 
1401 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
1402 		if (PageHighMem(skb_shinfo(skb)->frags[i].page))
1403 			return 1;
1404 
1405 #endif
1406 	return 0;
1407 }
1408 
1409 struct dev_gso_cb {
1410 	void (*destructor)(struct sk_buff *skb);
1411 };
1412 
1413 #define DEV_GSO_CB(skb) ((struct dev_gso_cb *)(skb)->cb)
1414 
1415 static void dev_gso_skb_destructor(struct sk_buff *skb)
1416 {
1417 	struct dev_gso_cb *cb;
1418 
1419 	do {
1420 		struct sk_buff *nskb = skb->next;
1421 
1422 		skb->next = nskb->next;
1423 		nskb->next = NULL;
1424 		kfree_skb(nskb);
1425 	} while (skb->next);
1426 
1427 	cb = DEV_GSO_CB(skb);
1428 	if (cb->destructor)
1429 		cb->destructor(skb);
1430 }
1431 
1432 /**
1433  *	dev_gso_segment - Perform emulated hardware segmentation on skb.
1434  *	@skb: buffer to segment
1435  *
1436  *	This function segments the given skb and stores the list of segments
1437  *	in skb->next.
1438  */
1439 static int dev_gso_segment(struct sk_buff *skb)
1440 {
1441 	struct net_device *dev = skb->dev;
1442 	struct sk_buff *segs;
1443 	int features = dev->features & ~(illegal_highdma(dev, skb) ?
1444 					 NETIF_F_SG : 0);
1445 
1446 	segs = skb_gso_segment(skb, features);
1447 
1448 	/* Verifying header integrity only. */
1449 	if (!segs)
1450 		return 0;
1451 
1452 	if (unlikely(IS_ERR(segs)))
1453 		return PTR_ERR(segs);
1454 
1455 	skb->next = segs;
1456 	DEV_GSO_CB(skb)->destructor = skb->destructor;
1457 	skb->destructor = dev_gso_skb_destructor;
1458 
1459 	return 0;
1460 }
1461 
1462 int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
1463 {
1464 	if (likely(!skb->next)) {
1465 		if (!list_empty(&ptype_all))
1466 			dev_queue_xmit_nit(skb, dev);
1467 
1468 		if (netif_needs_gso(dev, skb)) {
1469 			if (unlikely(dev_gso_segment(skb)))
1470 				goto out_kfree_skb;
1471 			if (skb->next)
1472 				goto gso;
1473 		}
1474 
1475 		return dev->hard_start_xmit(skb, dev);
1476 	}
1477 
1478 gso:
1479 	do {
1480 		struct sk_buff *nskb = skb->next;
1481 		int rc;
1482 
1483 		skb->next = nskb->next;
1484 		nskb->next = NULL;
1485 		rc = dev->hard_start_xmit(nskb, dev);
1486 		if (unlikely(rc)) {
1487 			nskb->next = skb->next;
1488 			skb->next = nskb;
1489 			return rc;
1490 		}
1491 		if (unlikely((netif_queue_stopped(dev) ||
1492 			     netif_subqueue_stopped(dev, skb->queue_mapping)) &&
1493 			     skb->next))
1494 			return NETDEV_TX_BUSY;
1495 	} while (skb->next);
1496 
1497 	skb->destructor = DEV_GSO_CB(skb)->destructor;
1498 
1499 out_kfree_skb:
1500 	kfree_skb(skb);
1501 	return 0;
1502 }
1503 
1504 #define HARD_TX_LOCK(dev, cpu) {			\
1505 	if ((dev->features & NETIF_F_LLTX) == 0) {	\
1506 		netif_tx_lock(dev);			\
1507 	}						\
1508 }
1509 
1510 #define HARD_TX_UNLOCK(dev) {				\
1511 	if ((dev->features & NETIF_F_LLTX) == 0) {	\
1512 		netif_tx_unlock(dev);			\
1513 	}						\
1514 }
1515 
1516 /**
1517  *	dev_queue_xmit - transmit a buffer
1518  *	@skb: buffer to transmit
1519  *
1520  *	Queue a buffer for transmission to a network device. The caller must
1521  *	have set the device and priority and built the buffer before calling
1522  *	this function. The function can be called from an interrupt.
1523  *
1524  *	A negative errno code is returned on a failure. A success does not
1525  *	guarantee the frame will be transmitted as it may be dropped due
1526  *	to congestion or traffic shaping.
1527  *
1528  * -----------------------------------------------------------------------------------
1529  *      I notice this method can also return errors from the queue disciplines,
1530  *      including NET_XMIT_DROP, which is a positive value.  So, errors can also
1531  *      be positive.
1532  *
1533  *      Regardless of the return value, the skb is consumed, so it is currently
1534  *      difficult to retry a send to this method.  (You can bump the ref count
1535  *      before sending to hold a reference for retry if you are careful.)
1536  *
1537  *      When calling this method, interrupts MUST be enabled.  This is because
1538  *      the BH enable code must have IRQs enabled so that it will not deadlock.
1539  *          --BLG
1540  */
1541 
1542 int dev_queue_xmit(struct sk_buff *skb)
1543 {
1544 	struct net_device *dev = skb->dev;
1545 	struct Qdisc *q;
1546 	int rc = -ENOMEM;
1547 
1548 	/* GSO will handle the following emulations directly. */
1549 	if (netif_needs_gso(dev, skb))
1550 		goto gso;
1551 
1552 	if (skb_shinfo(skb)->frag_list &&
1553 	    !(dev->features & NETIF_F_FRAGLIST) &&
1554 	    __skb_linearize(skb))
1555 		goto out_kfree_skb;
1556 
1557 	/* Fragmented skb is linearized if device does not support SG,
1558 	 * or if at least one of fragments is in highmem and device
1559 	 * does not support DMA from it.
1560 	 */
1561 	if (skb_shinfo(skb)->nr_frags &&
1562 	    (!(dev->features & NETIF_F_SG) || illegal_highdma(dev, skb)) &&
1563 	    __skb_linearize(skb))
1564 		goto out_kfree_skb;
1565 
1566 	/* If packet is not checksummed and device does not support
1567 	 * checksumming for this protocol, complete checksumming here.
1568 	 */
1569 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
1570 		skb_set_transport_header(skb, skb->csum_start -
1571 					      skb_headroom(skb));
1572 
1573 		if (!(dev->features & NETIF_F_GEN_CSUM) &&
1574 		    !((dev->features & NETIF_F_IP_CSUM) &&
1575 		      skb->protocol == htons(ETH_P_IP)) &&
1576 		    !((dev->features & NETIF_F_IPV6_CSUM) &&
1577 		      skb->protocol == htons(ETH_P_IPV6)))
1578 			if (skb_checksum_help(skb))
1579 				goto out_kfree_skb;
1580 	}
1581 
1582 gso:
1583 	spin_lock_prefetch(&dev->queue_lock);
1584 
1585 	/* Disable soft irqs for various locks below. Also
1586 	 * stops preemption for RCU.
1587 	 */
1588 	rcu_read_lock_bh();
1589 
1590 	/* Updates of qdisc are serialized by queue_lock.
1591 	 * The struct Qdisc which is pointed to by qdisc is now a
1592 	 * rcu structure - it may be accessed without acquiring
1593 	 * a lock (but the structure may be stale.) The freeing of the
1594 	 * qdisc will be deferred until it's known that there are no
1595 	 * more references to it.
1596 	 *
1597 	 * If the qdisc has an enqueue function, we still need to
1598 	 * hold the queue_lock before calling it, since queue_lock
1599 	 * also serializes access to the device queue.
1600 	 */
1601 
1602 	q = rcu_dereference(dev->qdisc);
1603 #ifdef CONFIG_NET_CLS_ACT
1604 	skb->tc_verd = SET_TC_AT(skb->tc_verd,AT_EGRESS);
1605 #endif
1606 	if (q->enqueue) {
1607 		/* Grab device queue */
1608 		spin_lock(&dev->queue_lock);
1609 		q = dev->qdisc;
1610 		if (q->enqueue) {
1611 			/* reset queue_mapping to zero */
1612 			skb->queue_mapping = 0;
1613 			rc = q->enqueue(skb, q);
1614 			qdisc_run(dev);
1615 			spin_unlock(&dev->queue_lock);
1616 
1617 			rc = rc == NET_XMIT_BYPASS ? NET_XMIT_SUCCESS : rc;
1618 			goto out;
1619 		}
1620 		spin_unlock(&dev->queue_lock);
1621 	}
1622 
1623 	/* The device has no queue. Common case for software devices:
1624 	   loopback, all the sorts of tunnels...
1625 
1626 	   Really, it is unlikely that netif_tx_lock protection is necessary
1627 	   here.  (f.e. loopback and IP tunnels are clean ignoring statistics
1628 	   counters.)
1629 	   However, it is possible, that they rely on protection
1630 	   made by us here.
1631 
1632 	   Check this and shot the lock. It is not prone from deadlocks.
1633 	   Either shot noqueue qdisc, it is even simpler 8)
1634 	 */
1635 	if (dev->flags & IFF_UP) {
1636 		int cpu = smp_processor_id(); /* ok because BHs are off */
1637 
1638 		if (dev->xmit_lock_owner != cpu) {
1639 
1640 			HARD_TX_LOCK(dev, cpu);
1641 
1642 			if (!netif_queue_stopped(dev) &&
1643 			    !netif_subqueue_stopped(dev, skb->queue_mapping)) {
1644 				rc = 0;
1645 				if (!dev_hard_start_xmit(skb, dev)) {
1646 					HARD_TX_UNLOCK(dev);
1647 					goto out;
1648 				}
1649 			}
1650 			HARD_TX_UNLOCK(dev);
1651 			if (net_ratelimit())
1652 				printk(KERN_CRIT "Virtual device %s asks to "
1653 				       "queue packet!\n", dev->name);
1654 		} else {
1655 			/* Recursion is detected! It is possible,
1656 			 * unfortunately */
1657 			if (net_ratelimit())
1658 				printk(KERN_CRIT "Dead loop on virtual device "
1659 				       "%s, fix it urgently!\n", dev->name);
1660 		}
1661 	}
1662 
1663 	rc = -ENETDOWN;
1664 	rcu_read_unlock_bh();
1665 
1666 out_kfree_skb:
1667 	kfree_skb(skb);
1668 	return rc;
1669 out:
1670 	rcu_read_unlock_bh();
1671 	return rc;
1672 }
1673 
1674 
1675 /*=======================================================================
1676 			Receiver routines
1677   =======================================================================*/
1678 
1679 int netdev_max_backlog __read_mostly = 1000;
1680 int netdev_budget __read_mostly = 300;
1681 int weight_p __read_mostly = 64;            /* old backlog weight */
1682 
1683 DEFINE_PER_CPU(struct netif_rx_stats, netdev_rx_stat) = { 0, };
1684 
1685 
1686 /**
1687  *	netif_rx	-	post buffer to the network code
1688  *	@skb: buffer to post
1689  *
1690  *	This function receives a packet from a device driver and queues it for
1691  *	the upper (protocol) levels to process.  It always succeeds. The buffer
1692  *	may be dropped during processing for congestion control or by the
1693  *	protocol layers.
1694  *
1695  *	return values:
1696  *	NET_RX_SUCCESS	(no congestion)
1697  *	NET_RX_CN_LOW   (low congestion)
1698  *	NET_RX_CN_MOD   (moderate congestion)
1699  *	NET_RX_CN_HIGH  (high congestion)
1700  *	NET_RX_DROP     (packet was dropped)
1701  *
1702  */
1703 
1704 int netif_rx(struct sk_buff *skb)
1705 {
1706 	struct softnet_data *queue;
1707 	unsigned long flags;
1708 
1709 	/* if netpoll wants it, pretend we never saw it */
1710 	if (netpoll_rx(skb))
1711 		return NET_RX_DROP;
1712 
1713 	if (!skb->tstamp.tv64)
1714 		net_timestamp(skb);
1715 
1716 	/*
1717 	 * The code is rearranged so that the path is the most
1718 	 * short when CPU is congested, but is still operating.
1719 	 */
1720 	local_irq_save(flags);
1721 	queue = &__get_cpu_var(softnet_data);
1722 
1723 	__get_cpu_var(netdev_rx_stat).total++;
1724 	if (queue->input_pkt_queue.qlen <= netdev_max_backlog) {
1725 		if (queue->input_pkt_queue.qlen) {
1726 enqueue:
1727 			dev_hold(skb->dev);
1728 			__skb_queue_tail(&queue->input_pkt_queue, skb);
1729 			local_irq_restore(flags);
1730 			return NET_RX_SUCCESS;
1731 		}
1732 
1733 		netif_rx_schedule(&queue->backlog_dev);
1734 		goto enqueue;
1735 	}
1736 
1737 	__get_cpu_var(netdev_rx_stat).dropped++;
1738 	local_irq_restore(flags);
1739 
1740 	kfree_skb(skb);
1741 	return NET_RX_DROP;
1742 }
1743 
1744 int netif_rx_ni(struct sk_buff *skb)
1745 {
1746 	int err;
1747 
1748 	preempt_disable();
1749 	err = netif_rx(skb);
1750 	if (local_softirq_pending())
1751 		do_softirq();
1752 	preempt_enable();
1753 
1754 	return err;
1755 }
1756 
1757 EXPORT_SYMBOL(netif_rx_ni);
1758 
1759 static inline struct net_device *skb_bond(struct sk_buff *skb)
1760 {
1761 	struct net_device *dev = skb->dev;
1762 
1763 	if (dev->master) {
1764 		if (skb_bond_should_drop(skb)) {
1765 			kfree_skb(skb);
1766 			return NULL;
1767 		}
1768 		skb->dev = dev->master;
1769 	}
1770 
1771 	return dev;
1772 }
1773 
1774 static void net_tx_action(struct softirq_action *h)
1775 {
1776 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
1777 
1778 	if (sd->completion_queue) {
1779 		struct sk_buff *clist;
1780 
1781 		local_irq_disable();
1782 		clist = sd->completion_queue;
1783 		sd->completion_queue = NULL;
1784 		local_irq_enable();
1785 
1786 		while (clist) {
1787 			struct sk_buff *skb = clist;
1788 			clist = clist->next;
1789 
1790 			BUG_TRAP(!atomic_read(&skb->users));
1791 			__kfree_skb(skb);
1792 		}
1793 	}
1794 
1795 	if (sd->output_queue) {
1796 		struct net_device *head;
1797 
1798 		local_irq_disable();
1799 		head = sd->output_queue;
1800 		sd->output_queue = NULL;
1801 		local_irq_enable();
1802 
1803 		while (head) {
1804 			struct net_device *dev = head;
1805 			head = head->next_sched;
1806 
1807 			smp_mb__before_clear_bit();
1808 			clear_bit(__LINK_STATE_SCHED, &dev->state);
1809 
1810 			if (spin_trylock(&dev->queue_lock)) {
1811 				qdisc_run(dev);
1812 				spin_unlock(&dev->queue_lock);
1813 			} else {
1814 				netif_schedule(dev);
1815 			}
1816 		}
1817 	}
1818 }
1819 
1820 static inline int deliver_skb(struct sk_buff *skb,
1821 			      struct packet_type *pt_prev,
1822 			      struct net_device *orig_dev)
1823 {
1824 	atomic_inc(&skb->users);
1825 	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
1826 }
1827 
1828 #if defined(CONFIG_BRIDGE) || defined (CONFIG_BRIDGE_MODULE)
1829 /* These hooks defined here for ATM */
1830 struct net_bridge;
1831 struct net_bridge_fdb_entry *(*br_fdb_get_hook)(struct net_bridge *br,
1832 						unsigned char *addr);
1833 void (*br_fdb_put_hook)(struct net_bridge_fdb_entry *ent) __read_mostly;
1834 
1835 /*
1836  * If bridge module is loaded call bridging hook.
1837  *  returns NULL if packet was consumed.
1838  */
1839 struct sk_buff *(*br_handle_frame_hook)(struct net_bridge_port *p,
1840 					struct sk_buff *skb) __read_mostly;
1841 static inline struct sk_buff *handle_bridge(struct sk_buff *skb,
1842 					    struct packet_type **pt_prev, int *ret,
1843 					    struct net_device *orig_dev)
1844 {
1845 	struct net_bridge_port *port;
1846 
1847 	if (skb->pkt_type == PACKET_LOOPBACK ||
1848 	    (port = rcu_dereference(skb->dev->br_port)) == NULL)
1849 		return skb;
1850 
1851 	if (*pt_prev) {
1852 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
1853 		*pt_prev = NULL;
1854 	}
1855 
1856 	return br_handle_frame_hook(port, skb);
1857 }
1858 #else
1859 #define handle_bridge(skb, pt_prev, ret, orig_dev)	(skb)
1860 #endif
1861 
1862 #if defined(CONFIG_MACVLAN) || defined(CONFIG_MACVLAN_MODULE)
1863 struct sk_buff *(*macvlan_handle_frame_hook)(struct sk_buff *skb) __read_mostly;
1864 EXPORT_SYMBOL_GPL(macvlan_handle_frame_hook);
1865 
1866 static inline struct sk_buff *handle_macvlan(struct sk_buff *skb,
1867 					     struct packet_type **pt_prev,
1868 					     int *ret,
1869 					     struct net_device *orig_dev)
1870 {
1871 	if (skb->dev->macvlan_port == NULL)
1872 		return skb;
1873 
1874 	if (*pt_prev) {
1875 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
1876 		*pt_prev = NULL;
1877 	}
1878 	return macvlan_handle_frame_hook(skb);
1879 }
1880 #else
1881 #define handle_macvlan(skb, pt_prev, ret, orig_dev)	(skb)
1882 #endif
1883 
1884 #ifdef CONFIG_NET_CLS_ACT
1885 /* TODO: Maybe we should just force sch_ingress to be compiled in
1886  * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
1887  * a compare and 2 stores extra right now if we dont have it on
1888  * but have CONFIG_NET_CLS_ACT
1889  * NOTE: This doesnt stop any functionality; if you dont have
1890  * the ingress scheduler, you just cant add policies on ingress.
1891  *
1892  */
1893 static int ing_filter(struct sk_buff *skb)
1894 {
1895 	struct Qdisc *q;
1896 	struct net_device *dev = skb->dev;
1897 	int result = TC_ACT_OK;
1898 
1899 	if (dev->qdisc_ingress) {
1900 		__u32 ttl = (__u32) G_TC_RTTL(skb->tc_verd);
1901 		if (MAX_RED_LOOP < ttl++) {
1902 			printk(KERN_WARNING "Redir loop detected Dropping packet (%d->%d)\n",
1903 				skb->iif, skb->dev->ifindex);
1904 			return TC_ACT_SHOT;
1905 		}
1906 
1907 		skb->tc_verd = SET_TC_RTTL(skb->tc_verd,ttl);
1908 
1909 		skb->tc_verd = SET_TC_AT(skb->tc_verd,AT_INGRESS);
1910 
1911 		spin_lock(&dev->ingress_lock);
1912 		if ((q = dev->qdisc_ingress) != NULL)
1913 			result = q->enqueue(skb, q);
1914 		spin_unlock(&dev->ingress_lock);
1915 
1916 	}
1917 
1918 	return result;
1919 }
1920 #endif
1921 
1922 int netif_receive_skb(struct sk_buff *skb)
1923 {
1924 	struct packet_type *ptype, *pt_prev;
1925 	struct net_device *orig_dev;
1926 	int ret = NET_RX_DROP;
1927 	__be16 type;
1928 
1929 	/* if we've gotten here through NAPI, check netpoll */
1930 	if (skb->dev->poll && netpoll_rx(skb))
1931 		return NET_RX_DROP;
1932 
1933 	if (!skb->tstamp.tv64)
1934 		net_timestamp(skb);
1935 
1936 	if (!skb->iif)
1937 		skb->iif = skb->dev->ifindex;
1938 
1939 	orig_dev = skb_bond(skb);
1940 
1941 	if (!orig_dev)
1942 		return NET_RX_DROP;
1943 
1944 	__get_cpu_var(netdev_rx_stat).total++;
1945 
1946 	skb_reset_network_header(skb);
1947 	skb_reset_transport_header(skb);
1948 	skb->mac_len = skb->network_header - skb->mac_header;
1949 
1950 	pt_prev = NULL;
1951 
1952 	rcu_read_lock();
1953 
1954 #ifdef CONFIG_NET_CLS_ACT
1955 	if (skb->tc_verd & TC_NCLS) {
1956 		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
1957 		goto ncls;
1958 	}
1959 #endif
1960 
1961 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
1962 		if (!ptype->dev || ptype->dev == skb->dev) {
1963 			if (pt_prev)
1964 				ret = deliver_skb(skb, pt_prev, orig_dev);
1965 			pt_prev = ptype;
1966 		}
1967 	}
1968 
1969 #ifdef CONFIG_NET_CLS_ACT
1970 	if (pt_prev) {
1971 		ret = deliver_skb(skb, pt_prev, orig_dev);
1972 		pt_prev = NULL; /* noone else should process this after*/
1973 	} else {
1974 		skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
1975 	}
1976 
1977 	ret = ing_filter(skb);
1978 
1979 	if (ret == TC_ACT_SHOT || (ret == TC_ACT_STOLEN)) {
1980 		kfree_skb(skb);
1981 		goto out;
1982 	}
1983 
1984 	skb->tc_verd = 0;
1985 ncls:
1986 #endif
1987 
1988 	skb = handle_bridge(skb, &pt_prev, &ret, orig_dev);
1989 	if (!skb)
1990 		goto out;
1991 	skb = handle_macvlan(skb, &pt_prev, &ret, orig_dev);
1992 	if (!skb)
1993 		goto out;
1994 
1995 	type = skb->protocol;
1996 	list_for_each_entry_rcu(ptype, &ptype_base[ntohs(type)&15], list) {
1997 		if (ptype->type == type &&
1998 		    (!ptype->dev || ptype->dev == skb->dev)) {
1999 			if (pt_prev)
2000 				ret = deliver_skb(skb, pt_prev, orig_dev);
2001 			pt_prev = ptype;
2002 		}
2003 	}
2004 
2005 	if (pt_prev) {
2006 		ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2007 	} else {
2008 		kfree_skb(skb);
2009 		/* Jamal, now you will not able to escape explaining
2010 		 * me how you were going to use this. :-)
2011 		 */
2012 		ret = NET_RX_DROP;
2013 	}
2014 
2015 out:
2016 	rcu_read_unlock();
2017 	return ret;
2018 }
2019 
2020 static int process_backlog(struct net_device *backlog_dev, int *budget)
2021 {
2022 	int work = 0;
2023 	int quota = min(backlog_dev->quota, *budget);
2024 	struct softnet_data *queue = &__get_cpu_var(softnet_data);
2025 	unsigned long start_time = jiffies;
2026 
2027 	backlog_dev->weight = weight_p;
2028 	for (;;) {
2029 		struct sk_buff *skb;
2030 		struct net_device *dev;
2031 
2032 		local_irq_disable();
2033 		skb = __skb_dequeue(&queue->input_pkt_queue);
2034 		if (!skb)
2035 			goto job_done;
2036 		local_irq_enable();
2037 
2038 		dev = skb->dev;
2039 
2040 		netif_receive_skb(skb);
2041 
2042 		dev_put(dev);
2043 
2044 		work++;
2045 
2046 		if (work >= quota || jiffies - start_time > 1)
2047 			break;
2048 
2049 	}
2050 
2051 	backlog_dev->quota -= work;
2052 	*budget -= work;
2053 	return -1;
2054 
2055 job_done:
2056 	backlog_dev->quota -= work;
2057 	*budget -= work;
2058 
2059 	list_del(&backlog_dev->poll_list);
2060 	smp_mb__before_clear_bit();
2061 	netif_poll_enable(backlog_dev);
2062 
2063 	local_irq_enable();
2064 	return 0;
2065 }
2066 
2067 static void net_rx_action(struct softirq_action *h)
2068 {
2069 	struct softnet_data *queue = &__get_cpu_var(softnet_data);
2070 	unsigned long start_time = jiffies;
2071 	int budget = netdev_budget;
2072 	void *have;
2073 
2074 	local_irq_disable();
2075 
2076 	while (!list_empty(&queue->poll_list)) {
2077 		struct net_device *dev;
2078 
2079 		if (budget <= 0 || jiffies - start_time > 1)
2080 			goto softnet_break;
2081 
2082 		local_irq_enable();
2083 
2084 		dev = list_entry(queue->poll_list.next,
2085 				 struct net_device, poll_list);
2086 		have = netpoll_poll_lock(dev);
2087 
2088 		if (dev->quota <= 0 || dev->poll(dev, &budget)) {
2089 			netpoll_poll_unlock(have);
2090 			local_irq_disable();
2091 			list_move_tail(&dev->poll_list, &queue->poll_list);
2092 			if (dev->quota < 0)
2093 				dev->quota += dev->weight;
2094 			else
2095 				dev->quota = dev->weight;
2096 		} else {
2097 			netpoll_poll_unlock(have);
2098 			dev_put(dev);
2099 			local_irq_disable();
2100 		}
2101 	}
2102 out:
2103 	local_irq_enable();
2104 #ifdef CONFIG_NET_DMA
2105 	/*
2106 	 * There may not be any more sk_buffs coming right now, so push
2107 	 * any pending DMA copies to hardware
2108 	 */
2109 	if (!cpus_empty(net_dma.channel_mask)) {
2110 		int chan_idx;
2111 		for_each_cpu_mask(chan_idx, net_dma.channel_mask) {
2112 			struct dma_chan *chan = net_dma.channels[chan_idx];
2113 			if (chan)
2114 				dma_async_memcpy_issue_pending(chan);
2115 		}
2116 	}
2117 #endif
2118 	return;
2119 
2120 softnet_break:
2121 	__get_cpu_var(netdev_rx_stat).time_squeeze++;
2122 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
2123 	goto out;
2124 }
2125 
2126 static gifconf_func_t * gifconf_list [NPROTO];
2127 
2128 /**
2129  *	register_gifconf	-	register a SIOCGIF handler
2130  *	@family: Address family
2131  *	@gifconf: Function handler
2132  *
2133  *	Register protocol dependent address dumping routines. The handler
2134  *	that is passed must not be freed or reused until it has been replaced
2135  *	by another handler.
2136  */
2137 int register_gifconf(unsigned int family, gifconf_func_t * gifconf)
2138 {
2139 	if (family >= NPROTO)
2140 		return -EINVAL;
2141 	gifconf_list[family] = gifconf;
2142 	return 0;
2143 }
2144 
2145 
2146 /*
2147  *	Map an interface index to its name (SIOCGIFNAME)
2148  */
2149 
2150 /*
2151  *	We need this ioctl for efficient implementation of the
2152  *	if_indextoname() function required by the IPv6 API.  Without
2153  *	it, we would have to search all the interfaces to find a
2154  *	match.  --pb
2155  */
2156 
2157 static int dev_ifname(struct ifreq __user *arg)
2158 {
2159 	struct net_device *dev;
2160 	struct ifreq ifr;
2161 
2162 	/*
2163 	 *	Fetch the caller's info block.
2164 	 */
2165 
2166 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
2167 		return -EFAULT;
2168 
2169 	read_lock(&dev_base_lock);
2170 	dev = __dev_get_by_index(ifr.ifr_ifindex);
2171 	if (!dev) {
2172 		read_unlock(&dev_base_lock);
2173 		return -ENODEV;
2174 	}
2175 
2176 	strcpy(ifr.ifr_name, dev->name);
2177 	read_unlock(&dev_base_lock);
2178 
2179 	if (copy_to_user(arg, &ifr, sizeof(struct ifreq)))
2180 		return -EFAULT;
2181 	return 0;
2182 }
2183 
2184 /*
2185  *	Perform a SIOCGIFCONF call. This structure will change
2186  *	size eventually, and there is nothing I can do about it.
2187  *	Thus we will need a 'compatibility mode'.
2188  */
2189 
2190 static int dev_ifconf(char __user *arg)
2191 {
2192 	struct ifconf ifc;
2193 	struct net_device *dev;
2194 	char __user *pos;
2195 	int len;
2196 	int total;
2197 	int i;
2198 
2199 	/*
2200 	 *	Fetch the caller's info block.
2201 	 */
2202 
2203 	if (copy_from_user(&ifc, arg, sizeof(struct ifconf)))
2204 		return -EFAULT;
2205 
2206 	pos = ifc.ifc_buf;
2207 	len = ifc.ifc_len;
2208 
2209 	/*
2210 	 *	Loop over the interfaces, and write an info block for each.
2211 	 */
2212 
2213 	total = 0;
2214 	for_each_netdev(dev) {
2215 		for (i = 0; i < NPROTO; i++) {
2216 			if (gifconf_list[i]) {
2217 				int done;
2218 				if (!pos)
2219 					done = gifconf_list[i](dev, NULL, 0);
2220 				else
2221 					done = gifconf_list[i](dev, pos + total,
2222 							       len - total);
2223 				if (done < 0)
2224 					return -EFAULT;
2225 				total += done;
2226 			}
2227 		}
2228 	}
2229 
2230 	/*
2231 	 *	All done.  Write the updated control block back to the caller.
2232 	 */
2233 	ifc.ifc_len = total;
2234 
2235 	/*
2236 	 * 	Both BSD and Solaris return 0 here, so we do too.
2237 	 */
2238 	return copy_to_user(arg, &ifc, sizeof(struct ifconf)) ? -EFAULT : 0;
2239 }
2240 
2241 #ifdef CONFIG_PROC_FS
2242 /*
2243  *	This is invoked by the /proc filesystem handler to display a device
2244  *	in detail.
2245  */
2246 void *dev_seq_start(struct seq_file *seq, loff_t *pos)
2247 {
2248 	loff_t off;
2249 	struct net_device *dev;
2250 
2251 	read_lock(&dev_base_lock);
2252 	if (!*pos)
2253 		return SEQ_START_TOKEN;
2254 
2255 	off = 1;
2256 	for_each_netdev(dev)
2257 		if (off++ == *pos)
2258 			return dev;
2259 
2260 	return NULL;
2261 }
2262 
2263 void *dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2264 {
2265 	++*pos;
2266 	return v == SEQ_START_TOKEN ?
2267 		first_net_device() : next_net_device((struct net_device *)v);
2268 }
2269 
2270 void dev_seq_stop(struct seq_file *seq, void *v)
2271 {
2272 	read_unlock(&dev_base_lock);
2273 }
2274 
2275 static void dev_seq_printf_stats(struct seq_file *seq, struct net_device *dev)
2276 {
2277 	struct net_device_stats *stats = dev->get_stats(dev);
2278 
2279 	seq_printf(seq, "%6s:%8lu %7lu %4lu %4lu %4lu %5lu %10lu %9lu "
2280 		   "%8lu %7lu %4lu %4lu %4lu %5lu %7lu %10lu\n",
2281 		   dev->name, stats->rx_bytes, stats->rx_packets,
2282 		   stats->rx_errors,
2283 		   stats->rx_dropped + stats->rx_missed_errors,
2284 		   stats->rx_fifo_errors,
2285 		   stats->rx_length_errors + stats->rx_over_errors +
2286 		    stats->rx_crc_errors + stats->rx_frame_errors,
2287 		   stats->rx_compressed, stats->multicast,
2288 		   stats->tx_bytes, stats->tx_packets,
2289 		   stats->tx_errors, stats->tx_dropped,
2290 		   stats->tx_fifo_errors, stats->collisions,
2291 		   stats->tx_carrier_errors +
2292 		    stats->tx_aborted_errors +
2293 		    stats->tx_window_errors +
2294 		    stats->tx_heartbeat_errors,
2295 		   stats->tx_compressed);
2296 }
2297 
2298 /*
2299  *	Called from the PROCfs module. This now uses the new arbitrary sized
2300  *	/proc/net interface to create /proc/net/dev
2301  */
2302 static int dev_seq_show(struct seq_file *seq, void *v)
2303 {
2304 	if (v == SEQ_START_TOKEN)
2305 		seq_puts(seq, "Inter-|   Receive                            "
2306 			      "                    |  Transmit\n"
2307 			      " face |bytes    packets errs drop fifo frame "
2308 			      "compressed multicast|bytes    packets errs "
2309 			      "drop fifo colls carrier compressed\n");
2310 	else
2311 		dev_seq_printf_stats(seq, v);
2312 	return 0;
2313 }
2314 
2315 static struct netif_rx_stats *softnet_get_online(loff_t *pos)
2316 {
2317 	struct netif_rx_stats *rc = NULL;
2318 
2319 	while (*pos < NR_CPUS)
2320 		if (cpu_online(*pos)) {
2321 			rc = &per_cpu(netdev_rx_stat, *pos);
2322 			break;
2323 		} else
2324 			++*pos;
2325 	return rc;
2326 }
2327 
2328 static void *softnet_seq_start(struct seq_file *seq, loff_t *pos)
2329 {
2330 	return softnet_get_online(pos);
2331 }
2332 
2333 static void *softnet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2334 {
2335 	++*pos;
2336 	return softnet_get_online(pos);
2337 }
2338 
2339 static void softnet_seq_stop(struct seq_file *seq, void *v)
2340 {
2341 }
2342 
2343 static int softnet_seq_show(struct seq_file *seq, void *v)
2344 {
2345 	struct netif_rx_stats *s = v;
2346 
2347 	seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x %08x\n",
2348 		   s->total, s->dropped, s->time_squeeze, 0,
2349 		   0, 0, 0, 0, /* was fastroute */
2350 		   s->cpu_collision );
2351 	return 0;
2352 }
2353 
2354 static const struct seq_operations dev_seq_ops = {
2355 	.start = dev_seq_start,
2356 	.next  = dev_seq_next,
2357 	.stop  = dev_seq_stop,
2358 	.show  = dev_seq_show,
2359 };
2360 
2361 static int dev_seq_open(struct inode *inode, struct file *file)
2362 {
2363 	return seq_open(file, &dev_seq_ops);
2364 }
2365 
2366 static const struct file_operations dev_seq_fops = {
2367 	.owner	 = THIS_MODULE,
2368 	.open    = dev_seq_open,
2369 	.read    = seq_read,
2370 	.llseek  = seq_lseek,
2371 	.release = seq_release,
2372 };
2373 
2374 static const struct seq_operations softnet_seq_ops = {
2375 	.start = softnet_seq_start,
2376 	.next  = softnet_seq_next,
2377 	.stop  = softnet_seq_stop,
2378 	.show  = softnet_seq_show,
2379 };
2380 
2381 static int softnet_seq_open(struct inode *inode, struct file *file)
2382 {
2383 	return seq_open(file, &softnet_seq_ops);
2384 }
2385 
2386 static const struct file_operations softnet_seq_fops = {
2387 	.owner	 = THIS_MODULE,
2388 	.open    = softnet_seq_open,
2389 	.read    = seq_read,
2390 	.llseek  = seq_lseek,
2391 	.release = seq_release,
2392 };
2393 
2394 static void *ptype_get_idx(loff_t pos)
2395 {
2396 	struct packet_type *pt = NULL;
2397 	loff_t i = 0;
2398 	int t;
2399 
2400 	list_for_each_entry_rcu(pt, &ptype_all, list) {
2401 		if (i == pos)
2402 			return pt;
2403 		++i;
2404 	}
2405 
2406 	for (t = 0; t < 16; t++) {
2407 		list_for_each_entry_rcu(pt, &ptype_base[t], list) {
2408 			if (i == pos)
2409 				return pt;
2410 			++i;
2411 		}
2412 	}
2413 	return NULL;
2414 }
2415 
2416 static void *ptype_seq_start(struct seq_file *seq, loff_t *pos)
2417 {
2418 	rcu_read_lock();
2419 	return *pos ? ptype_get_idx(*pos - 1) : SEQ_START_TOKEN;
2420 }
2421 
2422 static void *ptype_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2423 {
2424 	struct packet_type *pt;
2425 	struct list_head *nxt;
2426 	int hash;
2427 
2428 	++*pos;
2429 	if (v == SEQ_START_TOKEN)
2430 		return ptype_get_idx(0);
2431 
2432 	pt = v;
2433 	nxt = pt->list.next;
2434 	if (pt->type == htons(ETH_P_ALL)) {
2435 		if (nxt != &ptype_all)
2436 			goto found;
2437 		hash = 0;
2438 		nxt = ptype_base[0].next;
2439 	} else
2440 		hash = ntohs(pt->type) & 15;
2441 
2442 	while (nxt == &ptype_base[hash]) {
2443 		if (++hash >= 16)
2444 			return NULL;
2445 		nxt = ptype_base[hash].next;
2446 	}
2447 found:
2448 	return list_entry(nxt, struct packet_type, list);
2449 }
2450 
2451 static void ptype_seq_stop(struct seq_file *seq, void *v)
2452 {
2453 	rcu_read_unlock();
2454 }
2455 
2456 static void ptype_seq_decode(struct seq_file *seq, void *sym)
2457 {
2458 #ifdef CONFIG_KALLSYMS
2459 	unsigned long offset = 0, symsize;
2460 	const char *symname;
2461 	char *modname;
2462 	char namebuf[128];
2463 
2464 	symname = kallsyms_lookup((unsigned long)sym, &symsize, &offset,
2465 				  &modname, namebuf);
2466 
2467 	if (symname) {
2468 		char *delim = ":";
2469 
2470 		if (!modname)
2471 			modname = delim = "";
2472 		seq_printf(seq, "%s%s%s%s+0x%lx", delim, modname, delim,
2473 			   symname, offset);
2474 		return;
2475 	}
2476 #endif
2477 
2478 	seq_printf(seq, "[%p]", sym);
2479 }
2480 
2481 static int ptype_seq_show(struct seq_file *seq, void *v)
2482 {
2483 	struct packet_type *pt = v;
2484 
2485 	if (v == SEQ_START_TOKEN)
2486 		seq_puts(seq, "Type Device      Function\n");
2487 	else {
2488 		if (pt->type == htons(ETH_P_ALL))
2489 			seq_puts(seq, "ALL ");
2490 		else
2491 			seq_printf(seq, "%04x", ntohs(pt->type));
2492 
2493 		seq_printf(seq, " %-8s ",
2494 			   pt->dev ? pt->dev->name : "");
2495 		ptype_seq_decode(seq,  pt->func);
2496 		seq_putc(seq, '\n');
2497 	}
2498 
2499 	return 0;
2500 }
2501 
2502 static const struct seq_operations ptype_seq_ops = {
2503 	.start = ptype_seq_start,
2504 	.next  = ptype_seq_next,
2505 	.stop  = ptype_seq_stop,
2506 	.show  = ptype_seq_show,
2507 };
2508 
2509 static int ptype_seq_open(struct inode *inode, struct file *file)
2510 {
2511 	return seq_open(file, &ptype_seq_ops);
2512 }
2513 
2514 static const struct file_operations ptype_seq_fops = {
2515 	.owner	 = THIS_MODULE,
2516 	.open    = ptype_seq_open,
2517 	.read    = seq_read,
2518 	.llseek  = seq_lseek,
2519 	.release = seq_release,
2520 };
2521 
2522 
2523 static int __init dev_proc_init(void)
2524 {
2525 	int rc = -ENOMEM;
2526 
2527 	if (!proc_net_fops_create("dev", S_IRUGO, &dev_seq_fops))
2528 		goto out;
2529 	if (!proc_net_fops_create("softnet_stat", S_IRUGO, &softnet_seq_fops))
2530 		goto out_dev;
2531 	if (!proc_net_fops_create("ptype", S_IRUGO, &ptype_seq_fops))
2532 		goto out_dev2;
2533 
2534 	if (wext_proc_init())
2535 		goto out_softnet;
2536 	rc = 0;
2537 out:
2538 	return rc;
2539 out_softnet:
2540 	proc_net_remove("ptype");
2541 out_dev2:
2542 	proc_net_remove("softnet_stat");
2543 out_dev:
2544 	proc_net_remove("dev");
2545 	goto out;
2546 }
2547 #else
2548 #define dev_proc_init() 0
2549 #endif	/* CONFIG_PROC_FS */
2550 
2551 
2552 /**
2553  *	netdev_set_master	-	set up master/slave pair
2554  *	@slave: slave device
2555  *	@master: new master device
2556  *
2557  *	Changes the master device of the slave. Pass %NULL to break the
2558  *	bonding. The caller must hold the RTNL semaphore. On a failure
2559  *	a negative errno code is returned. On success the reference counts
2560  *	are adjusted, %RTM_NEWLINK is sent to the routing socket and the
2561  *	function returns zero.
2562  */
2563 int netdev_set_master(struct net_device *slave, struct net_device *master)
2564 {
2565 	struct net_device *old = slave->master;
2566 
2567 	ASSERT_RTNL();
2568 
2569 	if (master) {
2570 		if (old)
2571 			return -EBUSY;
2572 		dev_hold(master);
2573 	}
2574 
2575 	slave->master = master;
2576 
2577 	synchronize_net();
2578 
2579 	if (old)
2580 		dev_put(old);
2581 
2582 	if (master)
2583 		slave->flags |= IFF_SLAVE;
2584 	else
2585 		slave->flags &= ~IFF_SLAVE;
2586 
2587 	rtmsg_ifinfo(RTM_NEWLINK, slave, IFF_SLAVE);
2588 	return 0;
2589 }
2590 
2591 static void __dev_set_promiscuity(struct net_device *dev, int inc)
2592 {
2593 	unsigned short old_flags = dev->flags;
2594 
2595 	ASSERT_RTNL();
2596 
2597 	if ((dev->promiscuity += inc) == 0)
2598 		dev->flags &= ~IFF_PROMISC;
2599 	else
2600 		dev->flags |= IFF_PROMISC;
2601 	if (dev->flags != old_flags) {
2602 		printk(KERN_INFO "device %s %s promiscuous mode\n",
2603 		       dev->name, (dev->flags & IFF_PROMISC) ? "entered" :
2604 							       "left");
2605 		audit_log(current->audit_context, GFP_ATOMIC,
2606 			AUDIT_ANOM_PROMISCUOUS,
2607 			"dev=%s prom=%d old_prom=%d auid=%u",
2608 			dev->name, (dev->flags & IFF_PROMISC),
2609 			(old_flags & IFF_PROMISC),
2610 			audit_get_loginuid(current->audit_context));
2611 
2612 		if (dev->change_rx_flags)
2613 			dev->change_rx_flags(dev, IFF_PROMISC);
2614 	}
2615 }
2616 
2617 /**
2618  *	dev_set_promiscuity	- update promiscuity count on a device
2619  *	@dev: device
2620  *	@inc: modifier
2621  *
2622  *	Add or remove promiscuity from a device. While the count in the device
2623  *	remains above zero the interface remains promiscuous. Once it hits zero
2624  *	the device reverts back to normal filtering operation. A negative inc
2625  *	value is used to drop promiscuity on the device.
2626  */
2627 void dev_set_promiscuity(struct net_device *dev, int inc)
2628 {
2629 	unsigned short old_flags = dev->flags;
2630 
2631 	__dev_set_promiscuity(dev, inc);
2632 	if (dev->flags != old_flags)
2633 		dev_set_rx_mode(dev);
2634 }
2635 
2636 /**
2637  *	dev_set_allmulti	- update allmulti count on a device
2638  *	@dev: device
2639  *	@inc: modifier
2640  *
2641  *	Add or remove reception of all multicast frames to a device. While the
2642  *	count in the device remains above zero the interface remains listening
2643  *	to all interfaces. Once it hits zero the device reverts back to normal
2644  *	filtering operation. A negative @inc value is used to drop the counter
2645  *	when releasing a resource needing all multicasts.
2646  */
2647 
2648 void dev_set_allmulti(struct net_device *dev, int inc)
2649 {
2650 	unsigned short old_flags = dev->flags;
2651 
2652 	ASSERT_RTNL();
2653 
2654 	dev->flags |= IFF_ALLMULTI;
2655 	if ((dev->allmulti += inc) == 0)
2656 		dev->flags &= ~IFF_ALLMULTI;
2657 	if (dev->flags ^ old_flags) {
2658 		if (dev->change_rx_flags)
2659 			dev->change_rx_flags(dev, IFF_ALLMULTI);
2660 		dev_set_rx_mode(dev);
2661 	}
2662 }
2663 
2664 /*
2665  *	Upload unicast and multicast address lists to device and
2666  *	configure RX filtering. When the device doesn't support unicast
2667  *	filtering it is put in promiscous mode while unicast addresses
2668  *	are present.
2669  */
2670 void __dev_set_rx_mode(struct net_device *dev)
2671 {
2672 	/* dev_open will call this function so the list will stay sane. */
2673 	if (!(dev->flags&IFF_UP))
2674 		return;
2675 
2676 	if (!netif_device_present(dev))
2677 		return;
2678 
2679 	if (dev->set_rx_mode)
2680 		dev->set_rx_mode(dev);
2681 	else {
2682 		/* Unicast addresses changes may only happen under the rtnl,
2683 		 * therefore calling __dev_set_promiscuity here is safe.
2684 		 */
2685 		if (dev->uc_count > 0 && !dev->uc_promisc) {
2686 			__dev_set_promiscuity(dev, 1);
2687 			dev->uc_promisc = 1;
2688 		} else if (dev->uc_count == 0 && dev->uc_promisc) {
2689 			__dev_set_promiscuity(dev, -1);
2690 			dev->uc_promisc = 0;
2691 		}
2692 
2693 		if (dev->set_multicast_list)
2694 			dev->set_multicast_list(dev);
2695 	}
2696 }
2697 
2698 void dev_set_rx_mode(struct net_device *dev)
2699 {
2700 	netif_tx_lock_bh(dev);
2701 	__dev_set_rx_mode(dev);
2702 	netif_tx_unlock_bh(dev);
2703 }
2704 
2705 int __dev_addr_delete(struct dev_addr_list **list, int *count,
2706 		      void *addr, int alen, int glbl)
2707 {
2708 	struct dev_addr_list *da;
2709 
2710 	for (; (da = *list) != NULL; list = &da->next) {
2711 		if (memcmp(da->da_addr, addr, da->da_addrlen) == 0 &&
2712 		    alen == da->da_addrlen) {
2713 			if (glbl) {
2714 				int old_glbl = da->da_gusers;
2715 				da->da_gusers = 0;
2716 				if (old_glbl == 0)
2717 					break;
2718 			}
2719 			if (--da->da_users)
2720 				return 0;
2721 
2722 			*list = da->next;
2723 			kfree(da);
2724 			(*count)--;
2725 			return 0;
2726 		}
2727 	}
2728 	return -ENOENT;
2729 }
2730 
2731 int __dev_addr_add(struct dev_addr_list **list, int *count,
2732 		   void *addr, int alen, int glbl)
2733 {
2734 	struct dev_addr_list *da;
2735 
2736 	for (da = *list; da != NULL; da = da->next) {
2737 		if (memcmp(da->da_addr, addr, da->da_addrlen) == 0 &&
2738 		    da->da_addrlen == alen) {
2739 			if (glbl) {
2740 				int old_glbl = da->da_gusers;
2741 				da->da_gusers = 1;
2742 				if (old_glbl)
2743 					return 0;
2744 			}
2745 			da->da_users++;
2746 			return 0;
2747 		}
2748 	}
2749 
2750 	da = kmalloc(sizeof(*da), GFP_ATOMIC);
2751 	if (da == NULL)
2752 		return -ENOMEM;
2753 	memcpy(da->da_addr, addr, alen);
2754 	da->da_addrlen = alen;
2755 	da->da_users = 1;
2756 	da->da_gusers = glbl ? 1 : 0;
2757 	da->next = *list;
2758 	*list = da;
2759 	(*count)++;
2760 	return 0;
2761 }
2762 
2763 /**
2764  *	dev_unicast_delete	- Release secondary unicast address.
2765  *	@dev: device
2766  *	@addr: address to delete
2767  *	@alen: length of @addr
2768  *
2769  *	Release reference to a secondary unicast address and remove it
2770  *	from the device if the reference count drops to zero.
2771  *
2772  * 	The caller must hold the rtnl_mutex.
2773  */
2774 int dev_unicast_delete(struct net_device *dev, void *addr, int alen)
2775 {
2776 	int err;
2777 
2778 	ASSERT_RTNL();
2779 
2780 	netif_tx_lock_bh(dev);
2781 	err = __dev_addr_delete(&dev->uc_list, &dev->uc_count, addr, alen, 0);
2782 	if (!err)
2783 		__dev_set_rx_mode(dev);
2784 	netif_tx_unlock_bh(dev);
2785 	return err;
2786 }
2787 EXPORT_SYMBOL(dev_unicast_delete);
2788 
2789 /**
2790  *	dev_unicast_add		- add a secondary unicast address
2791  *	@dev: device
2792  *	@addr: address to delete
2793  *	@alen: length of @addr
2794  *
2795  *	Add a secondary unicast address to the device or increase
2796  *	the reference count if it already exists.
2797  *
2798  *	The caller must hold the rtnl_mutex.
2799  */
2800 int dev_unicast_add(struct net_device *dev, void *addr, int alen)
2801 {
2802 	int err;
2803 
2804 	ASSERT_RTNL();
2805 
2806 	netif_tx_lock_bh(dev);
2807 	err = __dev_addr_add(&dev->uc_list, &dev->uc_count, addr, alen, 0);
2808 	if (!err)
2809 		__dev_set_rx_mode(dev);
2810 	netif_tx_unlock_bh(dev);
2811 	return err;
2812 }
2813 EXPORT_SYMBOL(dev_unicast_add);
2814 
2815 static void __dev_addr_discard(struct dev_addr_list **list)
2816 {
2817 	struct dev_addr_list *tmp;
2818 
2819 	while (*list != NULL) {
2820 		tmp = *list;
2821 		*list = tmp->next;
2822 		if (tmp->da_users > tmp->da_gusers)
2823 			printk("__dev_addr_discard: address leakage! "
2824 			       "da_users=%d\n", tmp->da_users);
2825 		kfree(tmp);
2826 	}
2827 }
2828 
2829 static void dev_addr_discard(struct net_device *dev)
2830 {
2831 	netif_tx_lock_bh(dev);
2832 
2833 	__dev_addr_discard(&dev->uc_list);
2834 	dev->uc_count = 0;
2835 
2836 	__dev_addr_discard(&dev->mc_list);
2837 	dev->mc_count = 0;
2838 
2839 	netif_tx_unlock_bh(dev);
2840 }
2841 
2842 unsigned dev_get_flags(const struct net_device *dev)
2843 {
2844 	unsigned flags;
2845 
2846 	flags = (dev->flags & ~(IFF_PROMISC |
2847 				IFF_ALLMULTI |
2848 				IFF_RUNNING |
2849 				IFF_LOWER_UP |
2850 				IFF_DORMANT)) |
2851 		(dev->gflags & (IFF_PROMISC |
2852 				IFF_ALLMULTI));
2853 
2854 	if (netif_running(dev)) {
2855 		if (netif_oper_up(dev))
2856 			flags |= IFF_RUNNING;
2857 		if (netif_carrier_ok(dev))
2858 			flags |= IFF_LOWER_UP;
2859 		if (netif_dormant(dev))
2860 			flags |= IFF_DORMANT;
2861 	}
2862 
2863 	return flags;
2864 }
2865 
2866 int dev_change_flags(struct net_device *dev, unsigned flags)
2867 {
2868 	int ret, changes;
2869 	int old_flags = dev->flags;
2870 
2871 	ASSERT_RTNL();
2872 
2873 	/*
2874 	 *	Set the flags on our device.
2875 	 */
2876 
2877 	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
2878 			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
2879 			       IFF_AUTOMEDIA)) |
2880 		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
2881 				    IFF_ALLMULTI));
2882 
2883 	/*
2884 	 *	Load in the correct multicast list now the flags have changed.
2885 	 */
2886 
2887 	if (dev->change_rx_flags && (dev->flags ^ flags) & IFF_MULTICAST)
2888 		dev->change_rx_flags(dev, IFF_MULTICAST);
2889 
2890 	dev_set_rx_mode(dev);
2891 
2892 	/*
2893 	 *	Have we downed the interface. We handle IFF_UP ourselves
2894 	 *	according to user attempts to set it, rather than blindly
2895 	 *	setting it.
2896 	 */
2897 
2898 	ret = 0;
2899 	if ((old_flags ^ flags) & IFF_UP) {	/* Bit is different  ? */
2900 		ret = ((old_flags & IFF_UP) ? dev_close : dev_open)(dev);
2901 
2902 		if (!ret)
2903 			dev_set_rx_mode(dev);
2904 	}
2905 
2906 	if (dev->flags & IFF_UP &&
2907 	    ((old_flags ^ dev->flags) &~ (IFF_UP | IFF_PROMISC | IFF_ALLMULTI |
2908 					  IFF_VOLATILE)))
2909 		raw_notifier_call_chain(&netdev_chain,
2910 				NETDEV_CHANGE, dev);
2911 
2912 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
2913 		int inc = (flags & IFF_PROMISC) ? +1 : -1;
2914 		dev->gflags ^= IFF_PROMISC;
2915 		dev_set_promiscuity(dev, inc);
2916 	}
2917 
2918 	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
2919 	   is important. Some (broken) drivers set IFF_PROMISC, when
2920 	   IFF_ALLMULTI is requested not asking us and not reporting.
2921 	 */
2922 	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
2923 		int inc = (flags & IFF_ALLMULTI) ? +1 : -1;
2924 		dev->gflags ^= IFF_ALLMULTI;
2925 		dev_set_allmulti(dev, inc);
2926 	}
2927 
2928 	/* Exclude state transition flags, already notified */
2929 	changes = (old_flags ^ dev->flags) & ~(IFF_UP | IFF_RUNNING);
2930 	if (changes)
2931 		rtmsg_ifinfo(RTM_NEWLINK, dev, changes);
2932 
2933 	return ret;
2934 }
2935 
2936 int dev_set_mtu(struct net_device *dev, int new_mtu)
2937 {
2938 	int err;
2939 
2940 	if (new_mtu == dev->mtu)
2941 		return 0;
2942 
2943 	/*	MTU must be positive.	 */
2944 	if (new_mtu < 0)
2945 		return -EINVAL;
2946 
2947 	if (!netif_device_present(dev))
2948 		return -ENODEV;
2949 
2950 	err = 0;
2951 	if (dev->change_mtu)
2952 		err = dev->change_mtu(dev, new_mtu);
2953 	else
2954 		dev->mtu = new_mtu;
2955 	if (!err && dev->flags & IFF_UP)
2956 		raw_notifier_call_chain(&netdev_chain,
2957 				NETDEV_CHANGEMTU, dev);
2958 	return err;
2959 }
2960 
2961 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
2962 {
2963 	int err;
2964 
2965 	if (!dev->set_mac_address)
2966 		return -EOPNOTSUPP;
2967 	if (sa->sa_family != dev->type)
2968 		return -EINVAL;
2969 	if (!netif_device_present(dev))
2970 		return -ENODEV;
2971 	err = dev->set_mac_address(dev, sa);
2972 	if (!err)
2973 		raw_notifier_call_chain(&netdev_chain,
2974 				NETDEV_CHANGEADDR, dev);
2975 	return err;
2976 }
2977 
2978 /*
2979  *	Perform the SIOCxIFxxx calls.
2980  */
2981 static int dev_ifsioc(struct ifreq *ifr, unsigned int cmd)
2982 {
2983 	int err;
2984 	struct net_device *dev = __dev_get_by_name(ifr->ifr_name);
2985 
2986 	if (!dev)
2987 		return -ENODEV;
2988 
2989 	switch (cmd) {
2990 		case SIOCGIFFLAGS:	/* Get interface flags */
2991 			ifr->ifr_flags = dev_get_flags(dev);
2992 			return 0;
2993 
2994 		case SIOCSIFFLAGS:	/* Set interface flags */
2995 			return dev_change_flags(dev, ifr->ifr_flags);
2996 
2997 		case SIOCGIFMETRIC:	/* Get the metric on the interface
2998 					   (currently unused) */
2999 			ifr->ifr_metric = 0;
3000 			return 0;
3001 
3002 		case SIOCSIFMETRIC:	/* Set the metric on the interface
3003 					   (currently unused) */
3004 			return -EOPNOTSUPP;
3005 
3006 		case SIOCGIFMTU:	/* Get the MTU of a device */
3007 			ifr->ifr_mtu = dev->mtu;
3008 			return 0;
3009 
3010 		case SIOCSIFMTU:	/* Set the MTU of a device */
3011 			return dev_set_mtu(dev, ifr->ifr_mtu);
3012 
3013 		case SIOCGIFHWADDR:
3014 			if (!dev->addr_len)
3015 				memset(ifr->ifr_hwaddr.sa_data, 0, sizeof ifr->ifr_hwaddr.sa_data);
3016 			else
3017 				memcpy(ifr->ifr_hwaddr.sa_data, dev->dev_addr,
3018 				       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
3019 			ifr->ifr_hwaddr.sa_family = dev->type;
3020 			return 0;
3021 
3022 		case SIOCSIFHWADDR:
3023 			return dev_set_mac_address(dev, &ifr->ifr_hwaddr);
3024 
3025 		case SIOCSIFHWBROADCAST:
3026 			if (ifr->ifr_hwaddr.sa_family != dev->type)
3027 				return -EINVAL;
3028 			memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
3029 			       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
3030 			raw_notifier_call_chain(&netdev_chain,
3031 					    NETDEV_CHANGEADDR, dev);
3032 			return 0;
3033 
3034 		case SIOCGIFMAP:
3035 			ifr->ifr_map.mem_start = dev->mem_start;
3036 			ifr->ifr_map.mem_end   = dev->mem_end;
3037 			ifr->ifr_map.base_addr = dev->base_addr;
3038 			ifr->ifr_map.irq       = dev->irq;
3039 			ifr->ifr_map.dma       = dev->dma;
3040 			ifr->ifr_map.port      = dev->if_port;
3041 			return 0;
3042 
3043 		case SIOCSIFMAP:
3044 			if (dev->set_config) {
3045 				if (!netif_device_present(dev))
3046 					return -ENODEV;
3047 				return dev->set_config(dev, &ifr->ifr_map);
3048 			}
3049 			return -EOPNOTSUPP;
3050 
3051 		case SIOCADDMULTI:
3052 			if (!dev->set_multicast_list ||
3053 			    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
3054 				return -EINVAL;
3055 			if (!netif_device_present(dev))
3056 				return -ENODEV;
3057 			return dev_mc_add(dev, ifr->ifr_hwaddr.sa_data,
3058 					  dev->addr_len, 1);
3059 
3060 		case SIOCDELMULTI:
3061 			if (!dev->set_multicast_list ||
3062 			    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
3063 				return -EINVAL;
3064 			if (!netif_device_present(dev))
3065 				return -ENODEV;
3066 			return dev_mc_delete(dev, ifr->ifr_hwaddr.sa_data,
3067 					     dev->addr_len, 1);
3068 
3069 		case SIOCGIFINDEX:
3070 			ifr->ifr_ifindex = dev->ifindex;
3071 			return 0;
3072 
3073 		case SIOCGIFTXQLEN:
3074 			ifr->ifr_qlen = dev->tx_queue_len;
3075 			return 0;
3076 
3077 		case SIOCSIFTXQLEN:
3078 			if (ifr->ifr_qlen < 0)
3079 				return -EINVAL;
3080 			dev->tx_queue_len = ifr->ifr_qlen;
3081 			return 0;
3082 
3083 		case SIOCSIFNAME:
3084 			ifr->ifr_newname[IFNAMSIZ-1] = '\0';
3085 			return dev_change_name(dev, ifr->ifr_newname);
3086 
3087 		/*
3088 		 *	Unknown or private ioctl
3089 		 */
3090 
3091 		default:
3092 			if ((cmd >= SIOCDEVPRIVATE &&
3093 			    cmd <= SIOCDEVPRIVATE + 15) ||
3094 			    cmd == SIOCBONDENSLAVE ||
3095 			    cmd == SIOCBONDRELEASE ||
3096 			    cmd == SIOCBONDSETHWADDR ||
3097 			    cmd == SIOCBONDSLAVEINFOQUERY ||
3098 			    cmd == SIOCBONDINFOQUERY ||
3099 			    cmd == SIOCBONDCHANGEACTIVE ||
3100 			    cmd == SIOCGMIIPHY ||
3101 			    cmd == SIOCGMIIREG ||
3102 			    cmd == SIOCSMIIREG ||
3103 			    cmd == SIOCBRADDIF ||
3104 			    cmd == SIOCBRDELIF ||
3105 			    cmd == SIOCWANDEV) {
3106 				err = -EOPNOTSUPP;
3107 				if (dev->do_ioctl) {
3108 					if (netif_device_present(dev))
3109 						err = dev->do_ioctl(dev, ifr,
3110 								    cmd);
3111 					else
3112 						err = -ENODEV;
3113 				}
3114 			} else
3115 				err = -EINVAL;
3116 
3117 	}
3118 	return err;
3119 }
3120 
3121 /*
3122  *	This function handles all "interface"-type I/O control requests. The actual
3123  *	'doing' part of this is dev_ifsioc above.
3124  */
3125 
3126 /**
3127  *	dev_ioctl	-	network device ioctl
3128  *	@cmd: command to issue
3129  *	@arg: pointer to a struct ifreq in user space
3130  *
3131  *	Issue ioctl functions to devices. This is normally called by the
3132  *	user space syscall interfaces but can sometimes be useful for
3133  *	other purposes. The return value is the return from the syscall if
3134  *	positive or a negative errno code on error.
3135  */
3136 
3137 int dev_ioctl(unsigned int cmd, void __user *arg)
3138 {
3139 	struct ifreq ifr;
3140 	int ret;
3141 	char *colon;
3142 
3143 	/* One special case: SIOCGIFCONF takes ifconf argument
3144 	   and requires shared lock, because it sleeps writing
3145 	   to user space.
3146 	 */
3147 
3148 	if (cmd == SIOCGIFCONF) {
3149 		rtnl_lock();
3150 		ret = dev_ifconf((char __user *) arg);
3151 		rtnl_unlock();
3152 		return ret;
3153 	}
3154 	if (cmd == SIOCGIFNAME)
3155 		return dev_ifname((struct ifreq __user *)arg);
3156 
3157 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
3158 		return -EFAULT;
3159 
3160 	ifr.ifr_name[IFNAMSIZ-1] = 0;
3161 
3162 	colon = strchr(ifr.ifr_name, ':');
3163 	if (colon)
3164 		*colon = 0;
3165 
3166 	/*
3167 	 *	See which interface the caller is talking about.
3168 	 */
3169 
3170 	switch (cmd) {
3171 		/*
3172 		 *	These ioctl calls:
3173 		 *	- can be done by all.
3174 		 *	- atomic and do not require locking.
3175 		 *	- return a value
3176 		 */
3177 		case SIOCGIFFLAGS:
3178 		case SIOCGIFMETRIC:
3179 		case SIOCGIFMTU:
3180 		case SIOCGIFHWADDR:
3181 		case SIOCGIFSLAVE:
3182 		case SIOCGIFMAP:
3183 		case SIOCGIFINDEX:
3184 		case SIOCGIFTXQLEN:
3185 			dev_load(ifr.ifr_name);
3186 			read_lock(&dev_base_lock);
3187 			ret = dev_ifsioc(&ifr, cmd);
3188 			read_unlock(&dev_base_lock);
3189 			if (!ret) {
3190 				if (colon)
3191 					*colon = ':';
3192 				if (copy_to_user(arg, &ifr,
3193 						 sizeof(struct ifreq)))
3194 					ret = -EFAULT;
3195 			}
3196 			return ret;
3197 
3198 		case SIOCETHTOOL:
3199 			dev_load(ifr.ifr_name);
3200 			rtnl_lock();
3201 			ret = dev_ethtool(&ifr);
3202 			rtnl_unlock();
3203 			if (!ret) {
3204 				if (colon)
3205 					*colon = ':';
3206 				if (copy_to_user(arg, &ifr,
3207 						 sizeof(struct ifreq)))
3208 					ret = -EFAULT;
3209 			}
3210 			return ret;
3211 
3212 		/*
3213 		 *	These ioctl calls:
3214 		 *	- require superuser power.
3215 		 *	- require strict serialization.
3216 		 *	- return a value
3217 		 */
3218 		case SIOCGMIIPHY:
3219 		case SIOCGMIIREG:
3220 		case SIOCSIFNAME:
3221 			if (!capable(CAP_NET_ADMIN))
3222 				return -EPERM;
3223 			dev_load(ifr.ifr_name);
3224 			rtnl_lock();
3225 			ret = dev_ifsioc(&ifr, cmd);
3226 			rtnl_unlock();
3227 			if (!ret) {
3228 				if (colon)
3229 					*colon = ':';
3230 				if (copy_to_user(arg, &ifr,
3231 						 sizeof(struct ifreq)))
3232 					ret = -EFAULT;
3233 			}
3234 			return ret;
3235 
3236 		/*
3237 		 *	These ioctl calls:
3238 		 *	- require superuser power.
3239 		 *	- require strict serialization.
3240 		 *	- do not return a value
3241 		 */
3242 		case SIOCSIFFLAGS:
3243 		case SIOCSIFMETRIC:
3244 		case SIOCSIFMTU:
3245 		case SIOCSIFMAP:
3246 		case SIOCSIFHWADDR:
3247 		case SIOCSIFSLAVE:
3248 		case SIOCADDMULTI:
3249 		case SIOCDELMULTI:
3250 		case SIOCSIFHWBROADCAST:
3251 		case SIOCSIFTXQLEN:
3252 		case SIOCSMIIREG:
3253 		case SIOCBONDENSLAVE:
3254 		case SIOCBONDRELEASE:
3255 		case SIOCBONDSETHWADDR:
3256 		case SIOCBONDCHANGEACTIVE:
3257 		case SIOCBRADDIF:
3258 		case SIOCBRDELIF:
3259 			if (!capable(CAP_NET_ADMIN))
3260 				return -EPERM;
3261 			/* fall through */
3262 		case SIOCBONDSLAVEINFOQUERY:
3263 		case SIOCBONDINFOQUERY:
3264 			dev_load(ifr.ifr_name);
3265 			rtnl_lock();
3266 			ret = dev_ifsioc(&ifr, cmd);
3267 			rtnl_unlock();
3268 			return ret;
3269 
3270 		case SIOCGIFMEM:
3271 			/* Get the per device memory space. We can add this but
3272 			 * currently do not support it */
3273 		case SIOCSIFMEM:
3274 			/* Set the per device memory buffer space.
3275 			 * Not applicable in our case */
3276 		case SIOCSIFLINK:
3277 			return -EINVAL;
3278 
3279 		/*
3280 		 *	Unknown or private ioctl.
3281 		 */
3282 		default:
3283 			if (cmd == SIOCWANDEV ||
3284 			    (cmd >= SIOCDEVPRIVATE &&
3285 			     cmd <= SIOCDEVPRIVATE + 15)) {
3286 				dev_load(ifr.ifr_name);
3287 				rtnl_lock();
3288 				ret = dev_ifsioc(&ifr, cmd);
3289 				rtnl_unlock();
3290 				if (!ret && copy_to_user(arg, &ifr,
3291 							 sizeof(struct ifreq)))
3292 					ret = -EFAULT;
3293 				return ret;
3294 			}
3295 			/* Take care of Wireless Extensions */
3296 			if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST)
3297 				return wext_handle_ioctl(&ifr, cmd, arg);
3298 			return -EINVAL;
3299 	}
3300 }
3301 
3302 
3303 /**
3304  *	dev_new_index	-	allocate an ifindex
3305  *
3306  *	Returns a suitable unique value for a new device interface
3307  *	number.  The caller must hold the rtnl semaphore or the
3308  *	dev_base_lock to be sure it remains unique.
3309  */
3310 static int dev_new_index(void)
3311 {
3312 	static int ifindex;
3313 	for (;;) {
3314 		if (++ifindex <= 0)
3315 			ifindex = 1;
3316 		if (!__dev_get_by_index(ifindex))
3317 			return ifindex;
3318 	}
3319 }
3320 
3321 static int dev_boot_phase = 1;
3322 
3323 /* Delayed registration/unregisteration */
3324 static DEFINE_SPINLOCK(net_todo_list_lock);
3325 static struct list_head net_todo_list = LIST_HEAD_INIT(net_todo_list);
3326 
3327 static void net_set_todo(struct net_device *dev)
3328 {
3329 	spin_lock(&net_todo_list_lock);
3330 	list_add_tail(&dev->todo_list, &net_todo_list);
3331 	spin_unlock(&net_todo_list_lock);
3332 }
3333 
3334 /**
3335  *	register_netdevice	- register a network device
3336  *	@dev: device to register
3337  *
3338  *	Take a completed network device structure and add it to the kernel
3339  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
3340  *	chain. 0 is returned on success. A negative errno code is returned
3341  *	on a failure to set up the device, or if the name is a duplicate.
3342  *
3343  *	Callers must hold the rtnl semaphore. You may want
3344  *	register_netdev() instead of this.
3345  *
3346  *	BUGS:
3347  *	The locking appears insufficient to guarantee two parallel registers
3348  *	will not get the same name.
3349  */
3350 
3351 int register_netdevice(struct net_device *dev)
3352 {
3353 	struct hlist_head *head;
3354 	struct hlist_node *p;
3355 	int ret;
3356 
3357 	BUG_ON(dev_boot_phase);
3358 	ASSERT_RTNL();
3359 
3360 	might_sleep();
3361 
3362 	/* When net_device's are persistent, this will be fatal. */
3363 	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
3364 
3365 	spin_lock_init(&dev->queue_lock);
3366 	spin_lock_init(&dev->_xmit_lock);
3367 	netdev_set_lockdep_class(&dev->_xmit_lock, dev->type);
3368 	dev->xmit_lock_owner = -1;
3369 	spin_lock_init(&dev->ingress_lock);
3370 
3371 	dev->iflink = -1;
3372 
3373 	/* Init, if this function is available */
3374 	if (dev->init) {
3375 		ret = dev->init(dev);
3376 		if (ret) {
3377 			if (ret > 0)
3378 				ret = -EIO;
3379 			goto out;
3380 		}
3381 	}
3382 
3383 	if (!dev_valid_name(dev->name)) {
3384 		ret = -EINVAL;
3385 		goto err_uninit;
3386 	}
3387 
3388 	dev->ifindex = dev_new_index();
3389 	if (dev->iflink == -1)
3390 		dev->iflink = dev->ifindex;
3391 
3392 	/* Check for existence of name */
3393 	head = dev_name_hash(dev->name);
3394 	hlist_for_each(p, head) {
3395 		struct net_device *d
3396 			= hlist_entry(p, struct net_device, name_hlist);
3397 		if (!strncmp(d->name, dev->name, IFNAMSIZ)) {
3398 			ret = -EEXIST;
3399 			goto err_uninit;
3400 		}
3401 	}
3402 
3403 	/* Fix illegal checksum combinations */
3404 	if ((dev->features & NETIF_F_HW_CSUM) &&
3405 	    (dev->features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
3406 		printk(KERN_NOTICE "%s: mixed HW and IP checksum settings.\n",
3407 		       dev->name);
3408 		dev->features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
3409 	}
3410 
3411 	if ((dev->features & NETIF_F_NO_CSUM) &&
3412 	    (dev->features & (NETIF_F_HW_CSUM|NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
3413 		printk(KERN_NOTICE "%s: mixed no checksumming and other settings.\n",
3414 		       dev->name);
3415 		dev->features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM|NETIF_F_HW_CSUM);
3416 	}
3417 
3418 
3419 	/* Fix illegal SG+CSUM combinations. */
3420 	if ((dev->features & NETIF_F_SG) &&
3421 	    !(dev->features & NETIF_F_ALL_CSUM)) {
3422 		printk(KERN_NOTICE "%s: Dropping NETIF_F_SG since no checksum feature.\n",
3423 		       dev->name);
3424 		dev->features &= ~NETIF_F_SG;
3425 	}
3426 
3427 	/* TSO requires that SG is present as well. */
3428 	if ((dev->features & NETIF_F_TSO) &&
3429 	    !(dev->features & NETIF_F_SG)) {
3430 		printk(KERN_NOTICE "%s: Dropping NETIF_F_TSO since no SG feature.\n",
3431 		       dev->name);
3432 		dev->features &= ~NETIF_F_TSO;
3433 	}
3434 	if (dev->features & NETIF_F_UFO) {
3435 		if (!(dev->features & NETIF_F_HW_CSUM)) {
3436 			printk(KERN_ERR "%s: Dropping NETIF_F_UFO since no "
3437 					"NETIF_F_HW_CSUM feature.\n",
3438 							dev->name);
3439 			dev->features &= ~NETIF_F_UFO;
3440 		}
3441 		if (!(dev->features & NETIF_F_SG)) {
3442 			printk(KERN_ERR "%s: Dropping NETIF_F_UFO since no "
3443 					"NETIF_F_SG feature.\n",
3444 					dev->name);
3445 			dev->features &= ~NETIF_F_UFO;
3446 		}
3447 	}
3448 
3449 	/*
3450 	 *	nil rebuild_header routine,
3451 	 *	that should be never called and used as just bug trap.
3452 	 */
3453 
3454 	if (!dev->rebuild_header)
3455 		dev->rebuild_header = default_rebuild_header;
3456 
3457 	ret = netdev_register_sysfs(dev);
3458 	if (ret)
3459 		goto err_uninit;
3460 	dev->reg_state = NETREG_REGISTERED;
3461 
3462 	/*
3463 	 *	Default initial state at registry is that the
3464 	 *	device is present.
3465 	 */
3466 
3467 	set_bit(__LINK_STATE_PRESENT, &dev->state);
3468 
3469 	dev_init_scheduler(dev);
3470 	write_lock_bh(&dev_base_lock);
3471 	list_add_tail(&dev->dev_list, &dev_base_head);
3472 	hlist_add_head(&dev->name_hlist, head);
3473 	hlist_add_head(&dev->index_hlist, dev_index_hash(dev->ifindex));
3474 	dev_hold(dev);
3475 	write_unlock_bh(&dev_base_lock);
3476 
3477 	/* Notify protocols, that a new device appeared. */
3478 	ret = raw_notifier_call_chain(&netdev_chain, NETDEV_REGISTER, dev);
3479 	ret = notifier_to_errno(ret);
3480 	if (ret)
3481 		unregister_netdevice(dev);
3482 
3483 out:
3484 	return ret;
3485 
3486 err_uninit:
3487 	if (dev->uninit)
3488 		dev->uninit(dev);
3489 	goto out;
3490 }
3491 
3492 /**
3493  *	register_netdev	- register a network device
3494  *	@dev: device to register
3495  *
3496  *	Take a completed network device structure and add it to the kernel
3497  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
3498  *	chain. 0 is returned on success. A negative errno code is returned
3499  *	on a failure to set up the device, or if the name is a duplicate.
3500  *
3501  *	This is a wrapper around register_netdevice that takes the rtnl semaphore
3502  *	and expands the device name if you passed a format string to
3503  *	alloc_netdev.
3504  */
3505 int register_netdev(struct net_device *dev)
3506 {
3507 	int err;
3508 
3509 	rtnl_lock();
3510 
3511 	/*
3512 	 * If the name is a format string the caller wants us to do a
3513 	 * name allocation.
3514 	 */
3515 	if (strchr(dev->name, '%')) {
3516 		err = dev_alloc_name(dev, dev->name);
3517 		if (err < 0)
3518 			goto out;
3519 	}
3520 
3521 	err = register_netdevice(dev);
3522 out:
3523 	rtnl_unlock();
3524 	return err;
3525 }
3526 EXPORT_SYMBOL(register_netdev);
3527 
3528 /*
3529  * netdev_wait_allrefs - wait until all references are gone.
3530  *
3531  * This is called when unregistering network devices.
3532  *
3533  * Any protocol or device that holds a reference should register
3534  * for netdevice notification, and cleanup and put back the
3535  * reference if they receive an UNREGISTER event.
3536  * We can get stuck here if buggy protocols don't correctly
3537  * call dev_put.
3538  */
3539 static void netdev_wait_allrefs(struct net_device *dev)
3540 {
3541 	unsigned long rebroadcast_time, warning_time;
3542 
3543 	rebroadcast_time = warning_time = jiffies;
3544 	while (atomic_read(&dev->refcnt) != 0) {
3545 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
3546 			rtnl_lock();
3547 
3548 			/* Rebroadcast unregister notification */
3549 			raw_notifier_call_chain(&netdev_chain,
3550 					    NETDEV_UNREGISTER, dev);
3551 
3552 			if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
3553 				     &dev->state)) {
3554 				/* We must not have linkwatch events
3555 				 * pending on unregister. If this
3556 				 * happens, we simply run the queue
3557 				 * unscheduled, resulting in a noop
3558 				 * for this device.
3559 				 */
3560 				linkwatch_run_queue();
3561 			}
3562 
3563 			__rtnl_unlock();
3564 
3565 			rebroadcast_time = jiffies;
3566 		}
3567 
3568 		msleep(250);
3569 
3570 		if (time_after(jiffies, warning_time + 10 * HZ)) {
3571 			printk(KERN_EMERG "unregister_netdevice: "
3572 			       "waiting for %s to become free. Usage "
3573 			       "count = %d\n",
3574 			       dev->name, atomic_read(&dev->refcnt));
3575 			warning_time = jiffies;
3576 		}
3577 	}
3578 }
3579 
3580 /* The sequence is:
3581  *
3582  *	rtnl_lock();
3583  *	...
3584  *	register_netdevice(x1);
3585  *	register_netdevice(x2);
3586  *	...
3587  *	unregister_netdevice(y1);
3588  *	unregister_netdevice(y2);
3589  *      ...
3590  *	rtnl_unlock();
3591  *	free_netdev(y1);
3592  *	free_netdev(y2);
3593  *
3594  * We are invoked by rtnl_unlock() after it drops the semaphore.
3595  * This allows us to deal with problems:
3596  * 1) We can delete sysfs objects which invoke hotplug
3597  *    without deadlocking with linkwatch via keventd.
3598  * 2) Since we run with the RTNL semaphore not held, we can sleep
3599  *    safely in order to wait for the netdev refcnt to drop to zero.
3600  */
3601 static DEFINE_MUTEX(net_todo_run_mutex);
3602 void netdev_run_todo(void)
3603 {
3604 	struct list_head list;
3605 
3606 	/* Need to guard against multiple cpu's getting out of order. */
3607 	mutex_lock(&net_todo_run_mutex);
3608 
3609 	/* Not safe to do outside the semaphore.  We must not return
3610 	 * until all unregister events invoked by the local processor
3611 	 * have been completed (either by this todo run, or one on
3612 	 * another cpu).
3613 	 */
3614 	if (list_empty(&net_todo_list))
3615 		goto out;
3616 
3617 	/* Snapshot list, allow later requests */
3618 	spin_lock(&net_todo_list_lock);
3619 	list_replace_init(&net_todo_list, &list);
3620 	spin_unlock(&net_todo_list_lock);
3621 
3622 	while (!list_empty(&list)) {
3623 		struct net_device *dev
3624 			= list_entry(list.next, struct net_device, todo_list);
3625 		list_del(&dev->todo_list);
3626 
3627 		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
3628 			printk(KERN_ERR "network todo '%s' but state %d\n",
3629 			       dev->name, dev->reg_state);
3630 			dump_stack();
3631 			continue;
3632 		}
3633 
3634 		dev->reg_state = NETREG_UNREGISTERED;
3635 
3636 		netdev_wait_allrefs(dev);
3637 
3638 		/* paranoia */
3639 		BUG_ON(atomic_read(&dev->refcnt));
3640 		BUG_TRAP(!dev->ip_ptr);
3641 		BUG_TRAP(!dev->ip6_ptr);
3642 		BUG_TRAP(!dev->dn_ptr);
3643 
3644 		if (dev->destructor)
3645 			dev->destructor(dev);
3646 
3647 		/* Free network device */
3648 		kobject_put(&dev->dev.kobj);
3649 	}
3650 
3651 out:
3652 	mutex_unlock(&net_todo_run_mutex);
3653 }
3654 
3655 static struct net_device_stats *internal_stats(struct net_device *dev)
3656 {
3657 	return &dev->stats;
3658 }
3659 
3660 /**
3661  *	alloc_netdev_mq - allocate network device
3662  *	@sizeof_priv:	size of private data to allocate space for
3663  *	@name:		device name format string
3664  *	@setup:		callback to initialize device
3665  *	@queue_count:	the number of subqueues to allocate
3666  *
3667  *	Allocates a struct net_device with private data area for driver use
3668  *	and performs basic initialization.  Also allocates subquue structs
3669  *	for each queue on the device at the end of the netdevice.
3670  */
3671 struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name,
3672 		void (*setup)(struct net_device *), unsigned int queue_count)
3673 {
3674 	void *p;
3675 	struct net_device *dev;
3676 	int alloc_size;
3677 
3678 	BUG_ON(strlen(name) >= sizeof(dev->name));
3679 
3680 	/* ensure 32-byte alignment of both the device and private area */
3681 	alloc_size = (sizeof(*dev) + NETDEV_ALIGN_CONST +
3682 		     (sizeof(struct net_device_subqueue) * (queue_count - 1))) &
3683 		     ~NETDEV_ALIGN_CONST;
3684 	alloc_size += sizeof_priv + NETDEV_ALIGN_CONST;
3685 
3686 	p = kzalloc(alloc_size, GFP_KERNEL);
3687 	if (!p) {
3688 		printk(KERN_ERR "alloc_netdev: Unable to allocate device.\n");
3689 		return NULL;
3690 	}
3691 
3692 	dev = (struct net_device *)
3693 		(((long)p + NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST);
3694 	dev->padded = (char *)dev - (char *)p;
3695 
3696 	if (sizeof_priv) {
3697 		dev->priv = ((char *)dev +
3698 			     ((sizeof(struct net_device) +
3699 			       (sizeof(struct net_device_subqueue) *
3700 				(queue_count - 1)) + NETDEV_ALIGN_CONST)
3701 			      & ~NETDEV_ALIGN_CONST));
3702 	}
3703 
3704 	dev->egress_subqueue_count = queue_count;
3705 
3706 	dev->get_stats = internal_stats;
3707 	setup(dev);
3708 	strcpy(dev->name, name);
3709 	return dev;
3710 }
3711 EXPORT_SYMBOL(alloc_netdev_mq);
3712 
3713 /**
3714  *	free_netdev - free network device
3715  *	@dev: device
3716  *
3717  *	This function does the last stage of destroying an allocated device
3718  * 	interface. The reference to the device object is released.
3719  *	If this is the last reference then it will be freed.
3720  */
3721 void free_netdev(struct net_device *dev)
3722 {
3723 #ifdef CONFIG_SYSFS
3724 	/*  Compatibility with error handling in drivers */
3725 	if (dev->reg_state == NETREG_UNINITIALIZED) {
3726 		kfree((char *)dev - dev->padded);
3727 		return;
3728 	}
3729 
3730 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
3731 	dev->reg_state = NETREG_RELEASED;
3732 
3733 	/* will free via device release */
3734 	put_device(&dev->dev);
3735 #else
3736 	kfree((char *)dev - dev->padded);
3737 #endif
3738 }
3739 
3740 /* Synchronize with packet receive processing. */
3741 void synchronize_net(void)
3742 {
3743 	might_sleep();
3744 	synchronize_rcu();
3745 }
3746 
3747 /**
3748  *	unregister_netdevice - remove device from the kernel
3749  *	@dev: device
3750  *
3751  *	This function shuts down a device interface and removes it
3752  *	from the kernel tables. On success 0 is returned, on a failure
3753  *	a negative errno code is returned.
3754  *
3755  *	Callers must hold the rtnl semaphore.  You may want
3756  *	unregister_netdev() instead of this.
3757  */
3758 
3759 void unregister_netdevice(struct net_device *dev)
3760 {
3761 	BUG_ON(dev_boot_phase);
3762 	ASSERT_RTNL();
3763 
3764 	/* Some devices call without registering for initialization unwind. */
3765 	if (dev->reg_state == NETREG_UNINITIALIZED) {
3766 		printk(KERN_DEBUG "unregister_netdevice: device %s/%p never "
3767 				  "was registered\n", dev->name, dev);
3768 
3769 		WARN_ON(1);
3770 		return;
3771 	}
3772 
3773 	BUG_ON(dev->reg_state != NETREG_REGISTERED);
3774 
3775 	/* If device is running, close it first. */
3776 	if (dev->flags & IFF_UP)
3777 		dev_close(dev);
3778 
3779 	/* And unlink it from device chain. */
3780 	write_lock_bh(&dev_base_lock);
3781 	list_del(&dev->dev_list);
3782 	hlist_del(&dev->name_hlist);
3783 	hlist_del(&dev->index_hlist);
3784 	write_unlock_bh(&dev_base_lock);
3785 
3786 	dev->reg_state = NETREG_UNREGISTERING;
3787 
3788 	synchronize_net();
3789 
3790 	/* Shutdown queueing discipline. */
3791 	dev_shutdown(dev);
3792 
3793 
3794 	/* Notify protocols, that we are about to destroy
3795 	   this device. They should clean all the things.
3796 	*/
3797 	raw_notifier_call_chain(&netdev_chain, NETDEV_UNREGISTER, dev);
3798 
3799 	/*
3800 	 *	Flush the unicast and multicast chains
3801 	 */
3802 	dev_addr_discard(dev);
3803 
3804 	if (dev->uninit)
3805 		dev->uninit(dev);
3806 
3807 	/* Notifier chain MUST detach us from master device. */
3808 	BUG_TRAP(!dev->master);
3809 
3810 	/* Remove entries from sysfs */
3811 	netdev_unregister_sysfs(dev);
3812 
3813 	/* Finish processing unregister after unlock */
3814 	net_set_todo(dev);
3815 
3816 	synchronize_net();
3817 
3818 	dev_put(dev);
3819 }
3820 
3821 /**
3822  *	unregister_netdev - remove device from the kernel
3823  *	@dev: device
3824  *
3825  *	This function shuts down a device interface and removes it
3826  *	from the kernel tables. On success 0 is returned, on a failure
3827  *	a negative errno code is returned.
3828  *
3829  *	This is just a wrapper for unregister_netdevice that takes
3830  *	the rtnl semaphore.  In general you want to use this and not
3831  *	unregister_netdevice.
3832  */
3833 void unregister_netdev(struct net_device *dev)
3834 {
3835 	rtnl_lock();
3836 	unregister_netdevice(dev);
3837 	rtnl_unlock();
3838 }
3839 
3840 EXPORT_SYMBOL(unregister_netdev);
3841 
3842 static int dev_cpu_callback(struct notifier_block *nfb,
3843 			    unsigned long action,
3844 			    void *ocpu)
3845 {
3846 	struct sk_buff **list_skb;
3847 	struct net_device **list_net;
3848 	struct sk_buff *skb;
3849 	unsigned int cpu, oldcpu = (unsigned long)ocpu;
3850 	struct softnet_data *sd, *oldsd;
3851 
3852 	if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
3853 		return NOTIFY_OK;
3854 
3855 	local_irq_disable();
3856 	cpu = smp_processor_id();
3857 	sd = &per_cpu(softnet_data, cpu);
3858 	oldsd = &per_cpu(softnet_data, oldcpu);
3859 
3860 	/* Find end of our completion_queue. */
3861 	list_skb = &sd->completion_queue;
3862 	while (*list_skb)
3863 		list_skb = &(*list_skb)->next;
3864 	/* Append completion queue from offline CPU. */
3865 	*list_skb = oldsd->completion_queue;
3866 	oldsd->completion_queue = NULL;
3867 
3868 	/* Find end of our output_queue. */
3869 	list_net = &sd->output_queue;
3870 	while (*list_net)
3871 		list_net = &(*list_net)->next_sched;
3872 	/* Append output queue from offline CPU. */
3873 	*list_net = oldsd->output_queue;
3874 	oldsd->output_queue = NULL;
3875 
3876 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3877 	local_irq_enable();
3878 
3879 	/* Process offline CPU's input_pkt_queue */
3880 	while ((skb = __skb_dequeue(&oldsd->input_pkt_queue)))
3881 		netif_rx(skb);
3882 
3883 	return NOTIFY_OK;
3884 }
3885 
3886 #ifdef CONFIG_NET_DMA
3887 /**
3888  * net_dma_rebalance - try to maintain one DMA channel per CPU
3889  * @net_dma: DMA client and associated data (lock, channels, channel_mask)
3890  *
3891  * This is called when the number of channels allocated to the net_dma client
3892  * changes.  The net_dma client tries to have one DMA channel per CPU.
3893  */
3894 
3895 static void net_dma_rebalance(struct net_dma *net_dma)
3896 {
3897 	unsigned int cpu, i, n, chan_idx;
3898 	struct dma_chan *chan;
3899 
3900 	if (cpus_empty(net_dma->channel_mask)) {
3901 		for_each_online_cpu(cpu)
3902 			rcu_assign_pointer(per_cpu(softnet_data, cpu).net_dma, NULL);
3903 		return;
3904 	}
3905 
3906 	i = 0;
3907 	cpu = first_cpu(cpu_online_map);
3908 
3909 	for_each_cpu_mask(chan_idx, net_dma->channel_mask) {
3910 		chan = net_dma->channels[chan_idx];
3911 
3912 		n = ((num_online_cpus() / cpus_weight(net_dma->channel_mask))
3913 		   + (i < (num_online_cpus() %
3914 			cpus_weight(net_dma->channel_mask)) ? 1 : 0));
3915 
3916 		while(n) {
3917 			per_cpu(softnet_data, cpu).net_dma = chan;
3918 			cpu = next_cpu(cpu, cpu_online_map);
3919 			n--;
3920 		}
3921 		i++;
3922 	}
3923 }
3924 
3925 /**
3926  * netdev_dma_event - event callback for the net_dma_client
3927  * @client: should always be net_dma_client
3928  * @chan: DMA channel for the event
3929  * @state: DMA state to be handled
3930  */
3931 static enum dma_state_client
3932 netdev_dma_event(struct dma_client *client, struct dma_chan *chan,
3933 	enum dma_state state)
3934 {
3935 	int i, found = 0, pos = -1;
3936 	struct net_dma *net_dma =
3937 		container_of(client, struct net_dma, client);
3938 	enum dma_state_client ack = DMA_DUP; /* default: take no action */
3939 
3940 	spin_lock(&net_dma->lock);
3941 	switch (state) {
3942 	case DMA_RESOURCE_AVAILABLE:
3943 		for (i = 0; i < NR_CPUS; i++)
3944 			if (net_dma->channels[i] == chan) {
3945 				found = 1;
3946 				break;
3947 			} else if (net_dma->channels[i] == NULL && pos < 0)
3948 				pos = i;
3949 
3950 		if (!found && pos >= 0) {
3951 			ack = DMA_ACK;
3952 			net_dma->channels[pos] = chan;
3953 			cpu_set(pos, net_dma->channel_mask);
3954 			net_dma_rebalance(net_dma);
3955 		}
3956 		break;
3957 	case DMA_RESOURCE_REMOVED:
3958 		for (i = 0; i < NR_CPUS; i++)
3959 			if (net_dma->channels[i] == chan) {
3960 				found = 1;
3961 				pos = i;
3962 				break;
3963 			}
3964 
3965 		if (found) {
3966 			ack = DMA_ACK;
3967 			cpu_clear(pos, net_dma->channel_mask);
3968 			net_dma->channels[i] = NULL;
3969 			net_dma_rebalance(net_dma);
3970 		}
3971 		break;
3972 	default:
3973 		break;
3974 	}
3975 	spin_unlock(&net_dma->lock);
3976 
3977 	return ack;
3978 }
3979 
3980 /**
3981  * netdev_dma_regiser - register the networking subsystem as a DMA client
3982  */
3983 static int __init netdev_dma_register(void)
3984 {
3985 	spin_lock_init(&net_dma.lock);
3986 	dma_cap_set(DMA_MEMCPY, net_dma.client.cap_mask);
3987 	dma_async_client_register(&net_dma.client);
3988 	dma_async_client_chan_request(&net_dma.client);
3989 	return 0;
3990 }
3991 
3992 #else
3993 static int __init netdev_dma_register(void) { return -ENODEV; }
3994 #endif /* CONFIG_NET_DMA */
3995 
3996 /**
3997  *	netdev_compute_feature - compute conjunction of two feature sets
3998  *	@all: first feature set
3999  *	@one: second feature set
4000  *
4001  *	Computes a new feature set after adding a device with feature set
4002  *	@one to the master device with current feature set @all.  Returns
4003  *	the new feature set.
4004  */
4005 int netdev_compute_features(unsigned long all, unsigned long one)
4006 {
4007 	/* if device needs checksumming, downgrade to hw checksumming */
4008 	if (all & NETIF_F_NO_CSUM && !(one & NETIF_F_NO_CSUM))
4009 		all ^= NETIF_F_NO_CSUM | NETIF_F_HW_CSUM;
4010 
4011 	/* if device can't do all checksum, downgrade to ipv4/ipv6 */
4012 	if (all & NETIF_F_HW_CSUM && !(one & NETIF_F_HW_CSUM))
4013 		all ^= NETIF_F_HW_CSUM
4014 			| NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
4015 
4016 	if (one & NETIF_F_GSO)
4017 		one |= NETIF_F_GSO_SOFTWARE;
4018 	one |= NETIF_F_GSO;
4019 
4020 	/* If even one device supports robust GSO, enable it for all. */
4021 	if (one & NETIF_F_GSO_ROBUST)
4022 		all |= NETIF_F_GSO_ROBUST;
4023 
4024 	all &= one | NETIF_F_LLTX;
4025 
4026 	if (!(all & NETIF_F_ALL_CSUM))
4027 		all &= ~NETIF_F_SG;
4028 	if (!(all & NETIF_F_SG))
4029 		all &= ~NETIF_F_GSO_MASK;
4030 
4031 	return all;
4032 }
4033 EXPORT_SYMBOL(netdev_compute_features);
4034 
4035 /*
4036  *	Initialize the DEV module. At boot time this walks the device list and
4037  *	unhooks any devices that fail to initialise (normally hardware not
4038  *	present) and leaves us with a valid list of present and active devices.
4039  *
4040  */
4041 
4042 /*
4043  *       This is called single threaded during boot, so no need
4044  *       to take the rtnl semaphore.
4045  */
4046 static int __init net_dev_init(void)
4047 {
4048 	int i, rc = -ENOMEM;
4049 
4050 	BUG_ON(!dev_boot_phase);
4051 
4052 	if (dev_proc_init())
4053 		goto out;
4054 
4055 	if (netdev_sysfs_init())
4056 		goto out;
4057 
4058 	INIT_LIST_HEAD(&ptype_all);
4059 	for (i = 0; i < 16; i++)
4060 		INIT_LIST_HEAD(&ptype_base[i]);
4061 
4062 	for (i = 0; i < ARRAY_SIZE(dev_name_head); i++)
4063 		INIT_HLIST_HEAD(&dev_name_head[i]);
4064 
4065 	for (i = 0; i < ARRAY_SIZE(dev_index_head); i++)
4066 		INIT_HLIST_HEAD(&dev_index_head[i]);
4067 
4068 	/*
4069 	 *	Initialise the packet receive queues.
4070 	 */
4071 
4072 	for_each_possible_cpu(i) {
4073 		struct softnet_data *queue;
4074 
4075 		queue = &per_cpu(softnet_data, i);
4076 		skb_queue_head_init(&queue->input_pkt_queue);
4077 		queue->completion_queue = NULL;
4078 		INIT_LIST_HEAD(&queue->poll_list);
4079 		set_bit(__LINK_STATE_START, &queue->backlog_dev.state);
4080 		queue->backlog_dev.weight = weight_p;
4081 		queue->backlog_dev.poll = process_backlog;
4082 		atomic_set(&queue->backlog_dev.refcnt, 1);
4083 	}
4084 
4085 	netdev_dma_register();
4086 
4087 	dev_boot_phase = 0;
4088 
4089 	open_softirq(NET_TX_SOFTIRQ, net_tx_action, NULL);
4090 	open_softirq(NET_RX_SOFTIRQ, net_rx_action, NULL);
4091 
4092 	hotcpu_notifier(dev_cpu_callback, 0);
4093 	dst_init();
4094 	dev_mcast_init();
4095 	rc = 0;
4096 out:
4097 	return rc;
4098 }
4099 
4100 subsys_initcall(net_dev_init);
4101 
4102 EXPORT_SYMBOL(__dev_get_by_index);
4103 EXPORT_SYMBOL(__dev_get_by_name);
4104 EXPORT_SYMBOL(__dev_remove_pack);
4105 EXPORT_SYMBOL(dev_valid_name);
4106 EXPORT_SYMBOL(dev_add_pack);
4107 EXPORT_SYMBOL(dev_alloc_name);
4108 EXPORT_SYMBOL(dev_close);
4109 EXPORT_SYMBOL(dev_get_by_flags);
4110 EXPORT_SYMBOL(dev_get_by_index);
4111 EXPORT_SYMBOL(dev_get_by_name);
4112 EXPORT_SYMBOL(dev_open);
4113 EXPORT_SYMBOL(dev_queue_xmit);
4114 EXPORT_SYMBOL(dev_remove_pack);
4115 EXPORT_SYMBOL(dev_set_allmulti);
4116 EXPORT_SYMBOL(dev_set_promiscuity);
4117 EXPORT_SYMBOL(dev_change_flags);
4118 EXPORT_SYMBOL(dev_set_mtu);
4119 EXPORT_SYMBOL(dev_set_mac_address);
4120 EXPORT_SYMBOL(free_netdev);
4121 EXPORT_SYMBOL(netdev_boot_setup_check);
4122 EXPORT_SYMBOL(netdev_set_master);
4123 EXPORT_SYMBOL(netdev_state_change);
4124 EXPORT_SYMBOL(netif_receive_skb);
4125 EXPORT_SYMBOL(netif_rx);
4126 EXPORT_SYMBOL(register_gifconf);
4127 EXPORT_SYMBOL(register_netdevice);
4128 EXPORT_SYMBOL(register_netdevice_notifier);
4129 EXPORT_SYMBOL(skb_checksum_help);
4130 EXPORT_SYMBOL(synchronize_net);
4131 EXPORT_SYMBOL(unregister_netdevice);
4132 EXPORT_SYMBOL(unregister_netdevice_notifier);
4133 EXPORT_SYMBOL(net_enable_timestamp);
4134 EXPORT_SYMBOL(net_disable_timestamp);
4135 EXPORT_SYMBOL(dev_get_flags);
4136 
4137 #if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
4138 EXPORT_SYMBOL(br_handle_frame_hook);
4139 EXPORT_SYMBOL(br_fdb_get_hook);
4140 EXPORT_SYMBOL(br_fdb_put_hook);
4141 #endif
4142 
4143 #ifdef CONFIG_KMOD
4144 EXPORT_SYMBOL(dev_load);
4145 #endif
4146 
4147 EXPORT_PER_CPU_SYMBOL(softnet_data);
4148