xref: /linux/net/core/dev.c (revision d8327c784b51b57dac2c26cfad87dce0d68dfd98)
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/config.h>
80 #include <linux/cpu.h>
81 #include <linux/types.h>
82 #include <linux/kernel.h>
83 #include <linux/sched.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/divert.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 <linux/wireless.h>
114 #include <net/iw_handler.h>
115 #include <asm/current.h>
116 
117 /*
118  *	The list of packet types we will receive (as opposed to discard)
119  *	and the routines to invoke.
120  *
121  *	Why 16. Because with 16 the only overlap we get on a hash of the
122  *	low nibble of the protocol value is RARP/SNAP/X.25.
123  *
124  *      NOTE:  That is no longer true with the addition of VLAN tags.  Not
125  *             sure which should go first, but I bet it won't make much
126  *             difference if we are running VLANs.  The good news is that
127  *             this protocol won't be in the list unless compiled in, so
128  *             the average user (w/out VLANs) will not be adversly affected.
129  *             --BLG
130  *
131  *		0800	IP
132  *		8100    802.1Q VLAN
133  *		0001	802.3
134  *		0002	AX.25
135  *		0004	802.2
136  *		8035	RARP
137  *		0005	SNAP
138  *		0805	X.25
139  *		0806	ARP
140  *		8137	IPX
141  *		0009	Localtalk
142  *		86DD	IPv6
143  */
144 
145 static DEFINE_SPINLOCK(ptype_lock);
146 static struct list_head ptype_base[16];	/* 16 way hashed list */
147 static struct list_head ptype_all;		/* Taps */
148 
149 /*
150  * The @dev_base list is protected by @dev_base_lock and the rtln
151  * semaphore.
152  *
153  * Pure readers hold dev_base_lock for reading.
154  *
155  * Writers must hold the rtnl semaphore while they loop through the
156  * dev_base list, and hold dev_base_lock for writing when they do the
157  * actual updates.  This allows pure readers to access the list even
158  * while a writer is preparing to update it.
159  *
160  * To put it another way, dev_base_lock is held for writing only to
161  * protect against pure readers; the rtnl semaphore provides the
162  * protection against other writers.
163  *
164  * See, for example usages, register_netdevice() and
165  * unregister_netdevice(), which must be called with the rtnl
166  * semaphore held.
167  */
168 struct net_device *dev_base;
169 static struct net_device **dev_tail = &dev_base;
170 DEFINE_RWLOCK(dev_base_lock);
171 
172 EXPORT_SYMBOL(dev_base);
173 EXPORT_SYMBOL(dev_base_lock);
174 
175 #define NETDEV_HASHBITS	8
176 static struct hlist_head dev_name_head[1<<NETDEV_HASHBITS];
177 static struct hlist_head dev_index_head[1<<NETDEV_HASHBITS];
178 
179 static inline struct hlist_head *dev_name_hash(const char *name)
180 {
181 	unsigned hash = full_name_hash(name, strnlen(name, IFNAMSIZ));
182 	return &dev_name_head[hash & ((1<<NETDEV_HASHBITS)-1)];
183 }
184 
185 static inline struct hlist_head *dev_index_hash(int ifindex)
186 {
187 	return &dev_index_head[ifindex & ((1<<NETDEV_HASHBITS)-1)];
188 }
189 
190 /*
191  *	Our notifier list
192  */
193 
194 static struct notifier_block *netdev_chain;
195 
196 /*
197  *	Device drivers call our routines to queue packets here. We empty the
198  *	queue in the local softnet handler.
199  */
200 DEFINE_PER_CPU(struct softnet_data, softnet_data) = { NULL };
201 
202 #ifdef CONFIG_SYSFS
203 extern int netdev_sysfs_init(void);
204 extern int netdev_register_sysfs(struct net_device *);
205 extern void netdev_unregister_sysfs(struct net_device *);
206 #else
207 #define netdev_sysfs_init()	 	(0)
208 #define netdev_register_sysfs(dev)	(0)
209 #define	netdev_unregister_sysfs(dev)	do { } while(0)
210 #endif
211 
212 
213 /*******************************************************************************
214 
215 		Protocol management and registration routines
216 
217 *******************************************************************************/
218 
219 /*
220  *	For efficiency
221  */
222 
223 int netdev_nit;
224 
225 /*
226  *	Add a protocol ID to the list. Now that the input handler is
227  *	smarter we can dispense with all the messy stuff that used to be
228  *	here.
229  *
230  *	BEWARE!!! Protocol handlers, mangling input packets,
231  *	MUST BE last in hash buckets and checking protocol handlers
232  *	MUST start from promiscuous ptype_all chain in net_bh.
233  *	It is true now, do not change it.
234  *	Explanation follows: if protocol handler, mangling packet, will
235  *	be the first on list, it is not able to sense, that packet
236  *	is cloned and should be copied-on-write, so that it will
237  *	change it and subsequent readers will get broken packet.
238  *							--ANK (980803)
239  */
240 
241 /**
242  *	dev_add_pack - add packet handler
243  *	@pt: packet type declaration
244  *
245  *	Add a protocol handler to the networking stack. The passed &packet_type
246  *	is linked into kernel lists and may not be freed until it has been
247  *	removed from the kernel lists.
248  *
249  *	This call does not sleep therefore it can not
250  *	guarantee all CPU's that are in middle of receiving packets
251  *	will see the new packet type (until the next received packet).
252  */
253 
254 void dev_add_pack(struct packet_type *pt)
255 {
256 	int hash;
257 
258 	spin_lock_bh(&ptype_lock);
259 	if (pt->type == htons(ETH_P_ALL)) {
260 		netdev_nit++;
261 		list_add_rcu(&pt->list, &ptype_all);
262 	} else {
263 		hash = ntohs(pt->type) & 15;
264 		list_add_rcu(&pt->list, &ptype_base[hash]);
265 	}
266 	spin_unlock_bh(&ptype_lock);
267 }
268 
269 /**
270  *	__dev_remove_pack	 - remove packet handler
271  *	@pt: packet type declaration
272  *
273  *	Remove a protocol handler that was previously added to the kernel
274  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
275  *	from the kernel lists and can be freed or reused once this function
276  *	returns.
277  *
278  *      The packet type might still be in use by receivers
279  *	and must not be freed until after all the CPU's have gone
280  *	through a quiescent state.
281  */
282 void __dev_remove_pack(struct packet_type *pt)
283 {
284 	struct list_head *head;
285 	struct packet_type *pt1;
286 
287 	spin_lock_bh(&ptype_lock);
288 
289 	if (pt->type == htons(ETH_P_ALL)) {
290 		netdev_nit--;
291 		head = &ptype_all;
292 	} else
293 		head = &ptype_base[ntohs(pt->type) & 15];
294 
295 	list_for_each_entry(pt1, head, list) {
296 		if (pt == pt1) {
297 			list_del_rcu(&pt->list);
298 			goto out;
299 		}
300 	}
301 
302 	printk(KERN_WARNING "dev_remove_pack: %p not found.\n", pt);
303 out:
304 	spin_unlock_bh(&ptype_lock);
305 }
306 /**
307  *	dev_remove_pack	 - remove packet handler
308  *	@pt: packet type declaration
309  *
310  *	Remove a protocol handler that was previously added to the kernel
311  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
312  *	from the kernel lists and can be freed or reused once this function
313  *	returns.
314  *
315  *	This call sleeps to guarantee that no CPU is looking at the packet
316  *	type after return.
317  */
318 void dev_remove_pack(struct packet_type *pt)
319 {
320 	__dev_remove_pack(pt);
321 
322 	synchronize_net();
323 }
324 
325 /******************************************************************************
326 
327 		      Device Boot-time Settings Routines
328 
329 *******************************************************************************/
330 
331 /* Boot time configuration table */
332 static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX];
333 
334 /**
335  *	netdev_boot_setup_add	- add new setup entry
336  *	@name: name of the device
337  *	@map: configured settings for the device
338  *
339  *	Adds new setup entry to the dev_boot_setup list.  The function
340  *	returns 0 on error and 1 on success.  This is a generic routine to
341  *	all netdevices.
342  */
343 static int netdev_boot_setup_add(char *name, struct ifmap *map)
344 {
345 	struct netdev_boot_setup *s;
346 	int i;
347 
348 	s = dev_boot_setup;
349 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
350 		if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
351 			memset(s[i].name, 0, sizeof(s[i].name));
352 			strcpy(s[i].name, name);
353 			memcpy(&s[i].map, map, sizeof(s[i].map));
354 			break;
355 		}
356 	}
357 
358 	return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1;
359 }
360 
361 /**
362  *	netdev_boot_setup_check	- check boot time settings
363  *	@dev: the netdevice
364  *
365  * 	Check boot time settings for the device.
366  *	The found settings are set for the device to be used
367  *	later in the device probing.
368  *	Returns 0 if no settings found, 1 if they are.
369  */
370 int netdev_boot_setup_check(struct net_device *dev)
371 {
372 	struct netdev_boot_setup *s = dev_boot_setup;
373 	int i;
374 
375 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
376 		if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
377 		    !strncmp(dev->name, s[i].name, strlen(s[i].name))) {
378 			dev->irq 	= s[i].map.irq;
379 			dev->base_addr 	= s[i].map.base_addr;
380 			dev->mem_start 	= s[i].map.mem_start;
381 			dev->mem_end 	= s[i].map.mem_end;
382 			return 1;
383 		}
384 	}
385 	return 0;
386 }
387 
388 
389 /**
390  *	netdev_boot_base	- get address from boot time settings
391  *	@prefix: prefix for network device
392  *	@unit: id for network device
393  *
394  * 	Check boot time settings for the base address of device.
395  *	The found settings are set for the device to be used
396  *	later in the device probing.
397  *	Returns 0 if no settings found.
398  */
399 unsigned long netdev_boot_base(const char *prefix, int unit)
400 {
401 	const struct netdev_boot_setup *s = dev_boot_setup;
402 	char name[IFNAMSIZ];
403 	int i;
404 
405 	sprintf(name, "%s%d", prefix, unit);
406 
407 	/*
408 	 * If device already registered then return base of 1
409 	 * to indicate not to probe for this interface
410 	 */
411 	if (__dev_get_by_name(name))
412 		return 1;
413 
414 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++)
415 		if (!strcmp(name, s[i].name))
416 			return s[i].map.base_addr;
417 	return 0;
418 }
419 
420 /*
421  * Saves at boot time configured settings for any netdevice.
422  */
423 int __init netdev_boot_setup(char *str)
424 {
425 	int ints[5];
426 	struct ifmap map;
427 
428 	str = get_options(str, ARRAY_SIZE(ints), ints);
429 	if (!str || !*str)
430 		return 0;
431 
432 	/* Save settings */
433 	memset(&map, 0, sizeof(map));
434 	if (ints[0] > 0)
435 		map.irq = ints[1];
436 	if (ints[0] > 1)
437 		map.base_addr = ints[2];
438 	if (ints[0] > 2)
439 		map.mem_start = ints[3];
440 	if (ints[0] > 3)
441 		map.mem_end = ints[4];
442 
443 	/* Add new entry to the list */
444 	return netdev_boot_setup_add(str, &map);
445 }
446 
447 __setup("netdev=", netdev_boot_setup);
448 
449 /*******************************************************************************
450 
451 			    Device Interface Subroutines
452 
453 *******************************************************************************/
454 
455 /**
456  *	__dev_get_by_name	- find a device by its name
457  *	@name: name to find
458  *
459  *	Find an interface by name. Must be called under RTNL semaphore
460  *	or @dev_base_lock. If the name is found a pointer to the device
461  *	is returned. If the name is not found then %NULL is returned. The
462  *	reference counters are not incremented so the caller must be
463  *	careful with locks.
464  */
465 
466 struct net_device *__dev_get_by_name(const char *name)
467 {
468 	struct hlist_node *p;
469 
470 	hlist_for_each(p, dev_name_hash(name)) {
471 		struct net_device *dev
472 			= hlist_entry(p, struct net_device, name_hlist);
473 		if (!strncmp(dev->name, name, IFNAMSIZ))
474 			return dev;
475 	}
476 	return NULL;
477 }
478 
479 /**
480  *	dev_get_by_name		- find a device by its name
481  *	@name: name to find
482  *
483  *	Find an interface by name. This can be called from any
484  *	context and does its own locking. The returned handle has
485  *	the usage count incremented and the caller must use dev_put() to
486  *	release it when it is no longer needed. %NULL is returned if no
487  *	matching device is found.
488  */
489 
490 struct net_device *dev_get_by_name(const char *name)
491 {
492 	struct net_device *dev;
493 
494 	read_lock(&dev_base_lock);
495 	dev = __dev_get_by_name(name);
496 	if (dev)
497 		dev_hold(dev);
498 	read_unlock(&dev_base_lock);
499 	return dev;
500 }
501 
502 /**
503  *	__dev_get_by_index - find a device by its ifindex
504  *	@ifindex: index of device
505  *
506  *	Search for an interface by index. Returns %NULL if the device
507  *	is not found or a pointer to the device. The device has not
508  *	had its reference counter increased so the caller must be careful
509  *	about locking. The caller must hold either the RTNL semaphore
510  *	or @dev_base_lock.
511  */
512 
513 struct net_device *__dev_get_by_index(int ifindex)
514 {
515 	struct hlist_node *p;
516 
517 	hlist_for_each(p, dev_index_hash(ifindex)) {
518 		struct net_device *dev
519 			= hlist_entry(p, struct net_device, index_hlist);
520 		if (dev->ifindex == ifindex)
521 			return dev;
522 	}
523 	return NULL;
524 }
525 
526 
527 /**
528  *	dev_get_by_index - find a device by its ifindex
529  *	@ifindex: index of device
530  *
531  *	Search for an interface by index. Returns NULL if the device
532  *	is not found or a pointer to the device. The device returned has
533  *	had a reference added and the pointer is safe until the user calls
534  *	dev_put to indicate they have finished with it.
535  */
536 
537 struct net_device *dev_get_by_index(int ifindex)
538 {
539 	struct net_device *dev;
540 
541 	read_lock(&dev_base_lock);
542 	dev = __dev_get_by_index(ifindex);
543 	if (dev)
544 		dev_hold(dev);
545 	read_unlock(&dev_base_lock);
546 	return dev;
547 }
548 
549 /**
550  *	dev_getbyhwaddr - find a device by its hardware address
551  *	@type: media type of device
552  *	@ha: hardware address
553  *
554  *	Search for an interface by MAC address. Returns NULL if the device
555  *	is not found or a pointer to the device. The caller must hold the
556  *	rtnl semaphore. The returned device has not had its ref count increased
557  *	and the caller must therefore be careful about locking
558  *
559  *	BUGS:
560  *	If the API was consistent this would be __dev_get_by_hwaddr
561  */
562 
563 struct net_device *dev_getbyhwaddr(unsigned short type, char *ha)
564 {
565 	struct net_device *dev;
566 
567 	ASSERT_RTNL();
568 
569 	for (dev = dev_base; dev; dev = dev->next)
570 		if (dev->type == type &&
571 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
572 			break;
573 	return dev;
574 }
575 
576 EXPORT_SYMBOL(dev_getbyhwaddr);
577 
578 struct net_device *dev_getfirstbyhwtype(unsigned short type)
579 {
580 	struct net_device *dev;
581 
582 	rtnl_lock();
583 	for (dev = dev_base; dev; dev = dev->next) {
584 		if (dev->type == type) {
585 			dev_hold(dev);
586 			break;
587 		}
588 	}
589 	rtnl_unlock();
590 	return dev;
591 }
592 
593 EXPORT_SYMBOL(dev_getfirstbyhwtype);
594 
595 /**
596  *	dev_get_by_flags - find any device with given flags
597  *	@if_flags: IFF_* values
598  *	@mask: bitmask of bits in if_flags to check
599  *
600  *	Search for any interface with the given flags. Returns NULL if a device
601  *	is not found or a pointer to the device. The device returned has
602  *	had a reference added and the pointer is safe until the user calls
603  *	dev_put to indicate they have finished with it.
604  */
605 
606 struct net_device * dev_get_by_flags(unsigned short if_flags, unsigned short mask)
607 {
608 	struct net_device *dev;
609 
610 	read_lock(&dev_base_lock);
611 	for (dev = dev_base; dev != NULL; dev = dev->next) {
612 		if (((dev->flags ^ if_flags) & mask) == 0) {
613 			dev_hold(dev);
614 			break;
615 		}
616 	}
617 	read_unlock(&dev_base_lock);
618 	return dev;
619 }
620 
621 /**
622  *	dev_valid_name - check if name is okay for network device
623  *	@name: name string
624  *
625  *	Network device names need to be valid file names to
626  *	to allow sysfs to work
627  */
628 int dev_valid_name(const char *name)
629 {
630 	return !(*name == '\0'
631 		 || !strcmp(name, ".")
632 		 || !strcmp(name, "..")
633 		 || strchr(name, '/'));
634 }
635 
636 /**
637  *	dev_alloc_name - allocate a name for a device
638  *	@dev: device
639  *	@name: name format string
640  *
641  *	Passed a format string - eg "lt%d" it will try and find a suitable
642  *	id. Not efficient for many devices, not called a lot. The caller
643  *	must hold the dev_base or rtnl lock while allocating the name and
644  *	adding the device in order to avoid duplicates. Returns the number
645  *	of the unit assigned or a negative errno code.
646  */
647 
648 int dev_alloc_name(struct net_device *dev, const char *name)
649 {
650 	int i = 0;
651 	char buf[IFNAMSIZ];
652 	const char *p;
653 	const int max_netdevices = 8*PAGE_SIZE;
654 	long *inuse;
655 	struct net_device *d;
656 
657 	p = strnchr(name, IFNAMSIZ-1, '%');
658 	if (p) {
659 		/*
660 		 * Verify the string as this thing may have come from
661 		 * the user.  There must be either one "%d" and no other "%"
662 		 * characters.
663 		 */
664 		if (p[1] != 'd' || strchr(p + 2, '%'))
665 			return -EINVAL;
666 
667 		/* Use one page as a bit array of possible slots */
668 		inuse = (long *) get_zeroed_page(GFP_ATOMIC);
669 		if (!inuse)
670 			return -ENOMEM;
671 
672 		for (d = dev_base; d; d = d->next) {
673 			if (!sscanf(d->name, name, &i))
674 				continue;
675 			if (i < 0 || i >= max_netdevices)
676 				continue;
677 
678 			/*  avoid cases where sscanf is not exact inverse of printf */
679 			snprintf(buf, sizeof(buf), name, i);
680 			if (!strncmp(buf, d->name, IFNAMSIZ))
681 				set_bit(i, inuse);
682 		}
683 
684 		i = find_first_zero_bit(inuse, max_netdevices);
685 		free_page((unsigned long) inuse);
686 	}
687 
688 	snprintf(buf, sizeof(buf), name, i);
689 	if (!__dev_get_by_name(buf)) {
690 		strlcpy(dev->name, buf, IFNAMSIZ);
691 		return i;
692 	}
693 
694 	/* It is possible to run out of possible slots
695 	 * when the name is long and there isn't enough space left
696 	 * for the digits, or if all bits are used.
697 	 */
698 	return -ENFILE;
699 }
700 
701 
702 /**
703  *	dev_change_name - change name of a device
704  *	@dev: device
705  *	@newname: name (or format string) must be at least IFNAMSIZ
706  *
707  *	Change name of a device, can pass format strings "eth%d".
708  *	for wildcarding.
709  */
710 int dev_change_name(struct net_device *dev, char *newname)
711 {
712 	int err = 0;
713 
714 	ASSERT_RTNL();
715 
716 	if (dev->flags & IFF_UP)
717 		return -EBUSY;
718 
719 	if (!dev_valid_name(newname))
720 		return -EINVAL;
721 
722 	if (strchr(newname, '%')) {
723 		err = dev_alloc_name(dev, newname);
724 		if (err < 0)
725 			return err;
726 		strcpy(newname, dev->name);
727 	}
728 	else if (__dev_get_by_name(newname))
729 		return -EEXIST;
730 	else
731 		strlcpy(dev->name, newname, IFNAMSIZ);
732 
733 	err = class_device_rename(&dev->class_dev, dev->name);
734 	if (!err) {
735 		hlist_del(&dev->name_hlist);
736 		hlist_add_head(&dev->name_hlist, dev_name_hash(dev->name));
737 		notifier_call_chain(&netdev_chain, NETDEV_CHANGENAME, dev);
738 	}
739 
740 	return err;
741 }
742 
743 /**
744  *	netdev_features_change - device changes fatures
745  *	@dev: device to cause notification
746  *
747  *	Called to indicate a device has changed features.
748  */
749 void netdev_features_change(struct net_device *dev)
750 {
751 	notifier_call_chain(&netdev_chain, NETDEV_FEAT_CHANGE, dev);
752 }
753 EXPORT_SYMBOL(netdev_features_change);
754 
755 /**
756  *	netdev_state_change - device changes state
757  *	@dev: device to cause notification
758  *
759  *	Called to indicate a device has changed state. This function calls
760  *	the notifier chains for netdev_chain and sends a NEWLINK message
761  *	to the routing socket.
762  */
763 void netdev_state_change(struct net_device *dev)
764 {
765 	if (dev->flags & IFF_UP) {
766 		notifier_call_chain(&netdev_chain, NETDEV_CHANGE, dev);
767 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
768 	}
769 }
770 
771 /**
772  *	dev_load 	- load a network module
773  *	@name: name of interface
774  *
775  *	If a network interface is not present and the process has suitable
776  *	privileges this function loads the module. If module loading is not
777  *	available in this kernel then it becomes a nop.
778  */
779 
780 void dev_load(const char *name)
781 {
782 	struct net_device *dev;
783 
784 	read_lock(&dev_base_lock);
785 	dev = __dev_get_by_name(name);
786 	read_unlock(&dev_base_lock);
787 
788 	if (!dev && capable(CAP_SYS_MODULE))
789 		request_module("%s", name);
790 }
791 
792 static int default_rebuild_header(struct sk_buff *skb)
793 {
794 	printk(KERN_DEBUG "%s: default_rebuild_header called -- BUG!\n",
795 	       skb->dev ? skb->dev->name : "NULL!!!");
796 	kfree_skb(skb);
797 	return 1;
798 }
799 
800 
801 /**
802  *	dev_open	- prepare an interface for use.
803  *	@dev:	device to open
804  *
805  *	Takes a device from down to up state. The device's private open
806  *	function is invoked and then the multicast lists are loaded. Finally
807  *	the device is moved into the up state and a %NETDEV_UP message is
808  *	sent to the netdev notifier chain.
809  *
810  *	Calling this function on an active interface is a nop. On a failure
811  *	a negative errno code is returned.
812  */
813 int dev_open(struct net_device *dev)
814 {
815 	int ret = 0;
816 
817 	/*
818 	 *	Is it already up?
819 	 */
820 
821 	if (dev->flags & IFF_UP)
822 		return 0;
823 
824 	/*
825 	 *	Is it even present?
826 	 */
827 	if (!netif_device_present(dev))
828 		return -ENODEV;
829 
830 	/*
831 	 *	Call device private open method
832 	 */
833 	set_bit(__LINK_STATE_START, &dev->state);
834 	if (dev->open) {
835 		ret = dev->open(dev);
836 		if (ret)
837 			clear_bit(__LINK_STATE_START, &dev->state);
838 	}
839 
840  	/*
841 	 *	If it went open OK then:
842 	 */
843 
844 	if (!ret) {
845 		/*
846 		 *	Set the flags.
847 		 */
848 		dev->flags |= IFF_UP;
849 
850 		/*
851 		 *	Initialize multicasting status
852 		 */
853 		dev_mc_upload(dev);
854 
855 		/*
856 		 *	Wakeup transmit queue engine
857 		 */
858 		dev_activate(dev);
859 
860 		/*
861 		 *	... and announce new interface.
862 		 */
863 		notifier_call_chain(&netdev_chain, NETDEV_UP, dev);
864 	}
865 	return ret;
866 }
867 
868 /**
869  *	dev_close - shutdown an interface.
870  *	@dev: device to shutdown
871  *
872  *	This function moves an active device into down state. A
873  *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
874  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
875  *	chain.
876  */
877 int dev_close(struct net_device *dev)
878 {
879 	if (!(dev->flags & IFF_UP))
880 		return 0;
881 
882 	/*
883 	 *	Tell people we are going down, so that they can
884 	 *	prepare to death, when device is still operating.
885 	 */
886 	notifier_call_chain(&netdev_chain, NETDEV_GOING_DOWN, dev);
887 
888 	dev_deactivate(dev);
889 
890 	clear_bit(__LINK_STATE_START, &dev->state);
891 
892 	/* Synchronize to scheduled poll. We cannot touch poll list,
893 	 * it can be even on different cpu. So just clear netif_running(),
894 	 * and wait when poll really will happen. Actually, the best place
895 	 * for this is inside dev->stop() after device stopped its irq
896 	 * engine, but this requires more changes in devices. */
897 
898 	smp_mb__after_clear_bit(); /* Commit netif_running(). */
899 	while (test_bit(__LINK_STATE_RX_SCHED, &dev->state)) {
900 		/* No hurry. */
901 		msleep(1);
902 	}
903 
904 	/*
905 	 *	Call the device specific close. This cannot fail.
906 	 *	Only if device is UP
907 	 *
908 	 *	We allow it to be called even after a DETACH hot-plug
909 	 *	event.
910 	 */
911 	if (dev->stop)
912 		dev->stop(dev);
913 
914 	/*
915 	 *	Device is now down.
916 	 */
917 
918 	dev->flags &= ~IFF_UP;
919 
920 	/*
921 	 * Tell people we are down
922 	 */
923 	notifier_call_chain(&netdev_chain, NETDEV_DOWN, dev);
924 
925 	return 0;
926 }
927 
928 
929 /*
930  *	Device change register/unregister. These are not inline or static
931  *	as we export them to the world.
932  */
933 
934 /**
935  *	register_netdevice_notifier - register a network notifier block
936  *	@nb: notifier
937  *
938  *	Register a notifier to be called when network device events occur.
939  *	The notifier passed is linked into the kernel structures and must
940  *	not be reused until it has been unregistered. A negative errno code
941  *	is returned on a failure.
942  *
943  * 	When registered all registration and up events are replayed
944  *	to the new notifier to allow device to have a race free
945  *	view of the network device list.
946  */
947 
948 int register_netdevice_notifier(struct notifier_block *nb)
949 {
950 	struct net_device *dev;
951 	int err;
952 
953 	rtnl_lock();
954 	err = notifier_chain_register(&netdev_chain, nb);
955 	if (!err) {
956 		for (dev = dev_base; dev; dev = dev->next) {
957 			nb->notifier_call(nb, NETDEV_REGISTER, dev);
958 
959 			if (dev->flags & IFF_UP)
960 				nb->notifier_call(nb, NETDEV_UP, dev);
961 		}
962 	}
963 	rtnl_unlock();
964 	return err;
965 }
966 
967 /**
968  *	unregister_netdevice_notifier - unregister a network notifier block
969  *	@nb: notifier
970  *
971  *	Unregister a notifier previously registered by
972  *	register_netdevice_notifier(). The notifier is unlinked into the
973  *	kernel structures and may then be reused. A negative errno code
974  *	is returned on a failure.
975  */
976 
977 int unregister_netdevice_notifier(struct notifier_block *nb)
978 {
979 	return notifier_chain_unregister(&netdev_chain, nb);
980 }
981 
982 /**
983  *	call_netdevice_notifiers - call all network notifier blocks
984  *      @val: value passed unmodified to notifier function
985  *      @v:   pointer passed unmodified to notifier function
986  *
987  *	Call all network notifier blocks.  Parameters and return value
988  *	are as for notifier_call_chain().
989  */
990 
991 int call_netdevice_notifiers(unsigned long val, void *v)
992 {
993 	return notifier_call_chain(&netdev_chain, val, v);
994 }
995 
996 /* When > 0 there are consumers of rx skb time stamps */
997 static atomic_t netstamp_needed = ATOMIC_INIT(0);
998 
999 void net_enable_timestamp(void)
1000 {
1001 	atomic_inc(&netstamp_needed);
1002 }
1003 
1004 void net_disable_timestamp(void)
1005 {
1006 	atomic_dec(&netstamp_needed);
1007 }
1008 
1009 void __net_timestamp(struct sk_buff *skb)
1010 {
1011 	struct timeval tv;
1012 
1013 	do_gettimeofday(&tv);
1014 	skb_set_timestamp(skb, &tv);
1015 }
1016 EXPORT_SYMBOL(__net_timestamp);
1017 
1018 static inline void net_timestamp(struct sk_buff *skb)
1019 {
1020 	if (atomic_read(&netstamp_needed))
1021 		__net_timestamp(skb);
1022 	else {
1023 		skb->tstamp.off_sec = 0;
1024 		skb->tstamp.off_usec = 0;
1025 	}
1026 }
1027 
1028 /*
1029  *	Support routine. Sends outgoing frames to any network
1030  *	taps currently in use.
1031  */
1032 
1033 void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
1034 {
1035 	struct packet_type *ptype;
1036 
1037 	net_timestamp(skb);
1038 
1039 	rcu_read_lock();
1040 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
1041 		/* Never send packets back to the socket
1042 		 * they originated from - MvS (miquels@drinkel.ow.org)
1043 		 */
1044 		if ((ptype->dev == dev || !ptype->dev) &&
1045 		    (ptype->af_packet_priv == NULL ||
1046 		     (struct sock *)ptype->af_packet_priv != skb->sk)) {
1047 			struct sk_buff *skb2= skb_clone(skb, GFP_ATOMIC);
1048 			if (!skb2)
1049 				break;
1050 
1051 			/* skb->nh should be correctly
1052 			   set by sender, so that the second statement is
1053 			   just protection against buggy protocols.
1054 			 */
1055 			skb2->mac.raw = skb2->data;
1056 
1057 			if (skb2->nh.raw < skb2->data ||
1058 			    skb2->nh.raw > skb2->tail) {
1059 				if (net_ratelimit())
1060 					printk(KERN_CRIT "protocol %04x is "
1061 					       "buggy, dev %s\n",
1062 					       skb2->protocol, dev->name);
1063 				skb2->nh.raw = skb2->data;
1064 			}
1065 
1066 			skb2->h.raw = skb2->nh.raw;
1067 			skb2->pkt_type = PACKET_OUTGOING;
1068 			ptype->func(skb2, skb->dev, ptype, skb->dev);
1069 		}
1070 	}
1071 	rcu_read_unlock();
1072 }
1073 
1074 /*
1075  * Invalidate hardware checksum when packet is to be mangled, and
1076  * complete checksum manually on outgoing path.
1077  */
1078 int skb_checksum_help(struct sk_buff *skb, int inward)
1079 {
1080 	unsigned int csum;
1081 	int ret = 0, offset = skb->h.raw - skb->data;
1082 
1083 	if (inward) {
1084 		skb->ip_summed = CHECKSUM_NONE;
1085 		goto out;
1086 	}
1087 
1088 	if (skb_cloned(skb)) {
1089 		ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
1090 		if (ret)
1091 			goto out;
1092 	}
1093 
1094 	BUG_ON(offset > (int)skb->len);
1095 	csum = skb_checksum(skb, offset, skb->len-offset, 0);
1096 
1097 	offset = skb->tail - skb->h.raw;
1098 	BUG_ON(offset <= 0);
1099 	BUG_ON(skb->csum + 2 > offset);
1100 
1101 	*(u16*)(skb->h.raw + skb->csum) = csum_fold(csum);
1102 	skb->ip_summed = CHECKSUM_NONE;
1103 out:
1104 	return ret;
1105 }
1106 
1107 /* Take action when hardware reception checksum errors are detected. */
1108 #ifdef CONFIG_BUG
1109 void netdev_rx_csum_fault(struct net_device *dev)
1110 {
1111 	if (net_ratelimit()) {
1112 		printk(KERN_ERR "%s: hw csum failure.\n",
1113 			dev ? dev->name : "<unknown>");
1114 		dump_stack();
1115 	}
1116 }
1117 EXPORT_SYMBOL(netdev_rx_csum_fault);
1118 #endif
1119 
1120 #ifdef CONFIG_HIGHMEM
1121 /* Actually, we should eliminate this check as soon as we know, that:
1122  * 1. IOMMU is present and allows to map all the memory.
1123  * 2. No high memory really exists on this machine.
1124  */
1125 
1126 static inline int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
1127 {
1128 	int i;
1129 
1130 	if (dev->features & NETIF_F_HIGHDMA)
1131 		return 0;
1132 
1133 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
1134 		if (PageHighMem(skb_shinfo(skb)->frags[i].page))
1135 			return 1;
1136 
1137 	return 0;
1138 }
1139 #else
1140 #define illegal_highdma(dev, skb)	(0)
1141 #endif
1142 
1143 /* Keep head the same: replace data */
1144 int __skb_linearize(struct sk_buff *skb, gfp_t gfp_mask)
1145 {
1146 	unsigned int size;
1147 	u8 *data;
1148 	long offset;
1149 	struct skb_shared_info *ninfo;
1150 	int headerlen = skb->data - skb->head;
1151 	int expand = (skb->tail + skb->data_len) - skb->end;
1152 
1153 	if (skb_shared(skb))
1154 		BUG();
1155 
1156 	if (expand <= 0)
1157 		expand = 0;
1158 
1159 	size = skb->end - skb->head + expand;
1160 	size = SKB_DATA_ALIGN(size);
1161 	data = kmalloc(size + sizeof(struct skb_shared_info), gfp_mask);
1162 	if (!data)
1163 		return -ENOMEM;
1164 
1165 	/* Copy entire thing */
1166 	if (skb_copy_bits(skb, -headerlen, data, headerlen + skb->len))
1167 		BUG();
1168 
1169 	/* Set up shinfo */
1170 	ninfo = (struct skb_shared_info*)(data + size);
1171 	atomic_set(&ninfo->dataref, 1);
1172 	ninfo->tso_size = skb_shinfo(skb)->tso_size;
1173 	ninfo->tso_segs = skb_shinfo(skb)->tso_segs;
1174 	ninfo->nr_frags = 0;
1175 	ninfo->frag_list = NULL;
1176 
1177 	/* Offset between the two in bytes */
1178 	offset = data - skb->head;
1179 
1180 	/* Free old data. */
1181 	skb_release_data(skb);
1182 
1183 	skb->head = data;
1184 	skb->end  = data + size;
1185 
1186 	/* Set up new pointers */
1187 	skb->h.raw   += offset;
1188 	skb->nh.raw  += offset;
1189 	skb->mac.raw += offset;
1190 	skb->tail    += offset;
1191 	skb->data    += offset;
1192 
1193 	/* We are no longer a clone, even if we were. */
1194 	skb->cloned    = 0;
1195 
1196 	skb->tail     += skb->data_len;
1197 	skb->data_len  = 0;
1198 	return 0;
1199 }
1200 
1201 #define HARD_TX_LOCK(dev, cpu) {			\
1202 	if ((dev->features & NETIF_F_LLTX) == 0) {	\
1203 		spin_lock(&dev->xmit_lock);		\
1204 		dev->xmit_lock_owner = cpu;		\
1205 	}						\
1206 }
1207 
1208 #define HARD_TX_UNLOCK(dev) {				\
1209 	if ((dev->features & NETIF_F_LLTX) == 0) {	\
1210 		dev->xmit_lock_owner = -1;		\
1211 		spin_unlock(&dev->xmit_lock);		\
1212 	}						\
1213 }
1214 
1215 /**
1216  *	dev_queue_xmit - transmit a buffer
1217  *	@skb: buffer to transmit
1218  *
1219  *	Queue a buffer for transmission to a network device. The caller must
1220  *	have set the device and priority and built the buffer before calling
1221  *	this function. The function can be called from an interrupt.
1222  *
1223  *	A negative errno code is returned on a failure. A success does not
1224  *	guarantee the frame will be transmitted as it may be dropped due
1225  *	to congestion or traffic shaping.
1226  *
1227  * -----------------------------------------------------------------------------------
1228  *      I notice this method can also return errors from the queue disciplines,
1229  *      including NET_XMIT_DROP, which is a positive value.  So, errors can also
1230  *      be positive.
1231  *
1232  *      Regardless of the return value, the skb is consumed, so it is currently
1233  *      difficult to retry a send to this method.  (You can bump the ref count
1234  *      before sending to hold a reference for retry if you are careful.)
1235  *
1236  *      When calling this method, interrupts MUST be enabled.  This is because
1237  *      the BH enable code must have IRQs enabled so that it will not deadlock.
1238  *          --BLG
1239  */
1240 
1241 int dev_queue_xmit(struct sk_buff *skb)
1242 {
1243 	struct net_device *dev = skb->dev;
1244 	struct Qdisc *q;
1245 	int rc = -ENOMEM;
1246 
1247 	if (skb_shinfo(skb)->frag_list &&
1248 	    !(dev->features & NETIF_F_FRAGLIST) &&
1249 	    __skb_linearize(skb, GFP_ATOMIC))
1250 		goto out_kfree_skb;
1251 
1252 	/* Fragmented skb is linearized if device does not support SG,
1253 	 * or if at least one of fragments is in highmem and device
1254 	 * does not support DMA from it.
1255 	 */
1256 	if (skb_shinfo(skb)->nr_frags &&
1257 	    (!(dev->features & NETIF_F_SG) || illegal_highdma(dev, skb)) &&
1258 	    __skb_linearize(skb, GFP_ATOMIC))
1259 		goto out_kfree_skb;
1260 
1261 	/* If packet is not checksummed and device does not support
1262 	 * checksumming for this protocol, complete checksumming here.
1263 	 */
1264 	if (skb->ip_summed == CHECKSUM_HW &&
1265 	    (!(dev->features & (NETIF_F_HW_CSUM | NETIF_F_NO_CSUM)) &&
1266 	     (!(dev->features & NETIF_F_IP_CSUM) ||
1267 	      skb->protocol != htons(ETH_P_IP))))
1268 	      	if (skb_checksum_help(skb, 0))
1269 	      		goto out_kfree_skb;
1270 
1271 	spin_lock_prefetch(&dev->queue_lock);
1272 
1273 	/* Disable soft irqs for various locks below. Also
1274 	 * stops preemption for RCU.
1275 	 */
1276 	local_bh_disable();
1277 
1278 	/* Updates of qdisc are serialized by queue_lock.
1279 	 * The struct Qdisc which is pointed to by qdisc is now a
1280 	 * rcu structure - it may be accessed without acquiring
1281 	 * a lock (but the structure may be stale.) The freeing of the
1282 	 * qdisc will be deferred until it's known that there are no
1283 	 * more references to it.
1284 	 *
1285 	 * If the qdisc has an enqueue function, we still need to
1286 	 * hold the queue_lock before calling it, since queue_lock
1287 	 * also serializes access to the device queue.
1288 	 */
1289 
1290 	q = rcu_dereference(dev->qdisc);
1291 #ifdef CONFIG_NET_CLS_ACT
1292 	skb->tc_verd = SET_TC_AT(skb->tc_verd,AT_EGRESS);
1293 #endif
1294 	if (q->enqueue) {
1295 		/* Grab device queue */
1296 		spin_lock(&dev->queue_lock);
1297 
1298 		rc = q->enqueue(skb, q);
1299 
1300 		qdisc_run(dev);
1301 
1302 		spin_unlock(&dev->queue_lock);
1303 		rc = rc == NET_XMIT_BYPASS ? NET_XMIT_SUCCESS : rc;
1304 		goto out;
1305 	}
1306 
1307 	/* The device has no queue. Common case for software devices:
1308 	   loopback, all the sorts of tunnels...
1309 
1310 	   Really, it is unlikely that xmit_lock protection is necessary here.
1311 	   (f.e. loopback and IP tunnels are clean ignoring statistics
1312 	   counters.)
1313 	   However, it is possible, that they rely on protection
1314 	   made by us here.
1315 
1316 	   Check this and shot the lock. It is not prone from deadlocks.
1317 	   Either shot noqueue qdisc, it is even simpler 8)
1318 	 */
1319 	if (dev->flags & IFF_UP) {
1320 		int cpu = smp_processor_id(); /* ok because BHs are off */
1321 
1322 		if (dev->xmit_lock_owner != cpu) {
1323 
1324 			HARD_TX_LOCK(dev, cpu);
1325 
1326 			if (!netif_queue_stopped(dev)) {
1327 				if (netdev_nit)
1328 					dev_queue_xmit_nit(skb, dev);
1329 
1330 				rc = 0;
1331 				if (!dev->hard_start_xmit(skb, dev)) {
1332 					HARD_TX_UNLOCK(dev);
1333 					goto out;
1334 				}
1335 			}
1336 			HARD_TX_UNLOCK(dev);
1337 			if (net_ratelimit())
1338 				printk(KERN_CRIT "Virtual device %s asks to "
1339 				       "queue packet!\n", dev->name);
1340 		} else {
1341 			/* Recursion is detected! It is possible,
1342 			 * unfortunately */
1343 			if (net_ratelimit())
1344 				printk(KERN_CRIT "Dead loop on virtual device "
1345 				       "%s, fix it urgently!\n", dev->name);
1346 		}
1347 	}
1348 
1349 	rc = -ENETDOWN;
1350 	local_bh_enable();
1351 
1352 out_kfree_skb:
1353 	kfree_skb(skb);
1354 	return rc;
1355 out:
1356 	local_bh_enable();
1357 	return rc;
1358 }
1359 
1360 
1361 /*=======================================================================
1362 			Receiver routines
1363   =======================================================================*/
1364 
1365 int netdev_max_backlog = 1000;
1366 int netdev_budget = 300;
1367 int weight_p = 64;            /* old backlog weight */
1368 
1369 DEFINE_PER_CPU(struct netif_rx_stats, netdev_rx_stat) = { 0, };
1370 
1371 
1372 /**
1373  *	netif_rx	-	post buffer to the network code
1374  *	@skb: buffer to post
1375  *
1376  *	This function receives a packet from a device driver and queues it for
1377  *	the upper (protocol) levels to process.  It always succeeds. The buffer
1378  *	may be dropped during processing for congestion control or by the
1379  *	protocol layers.
1380  *
1381  *	return values:
1382  *	NET_RX_SUCCESS	(no congestion)
1383  *	NET_RX_CN_LOW   (low congestion)
1384  *	NET_RX_CN_MOD   (moderate congestion)
1385  *	NET_RX_CN_HIGH  (high congestion)
1386  *	NET_RX_DROP     (packet was dropped)
1387  *
1388  */
1389 
1390 int netif_rx(struct sk_buff *skb)
1391 {
1392 	struct softnet_data *queue;
1393 	unsigned long flags;
1394 
1395 	/* if netpoll wants it, pretend we never saw it */
1396 	if (netpoll_rx(skb))
1397 		return NET_RX_DROP;
1398 
1399 	if (!skb->tstamp.off_sec)
1400 		net_timestamp(skb);
1401 
1402 	/*
1403 	 * The code is rearranged so that the path is the most
1404 	 * short when CPU is congested, but is still operating.
1405 	 */
1406 	local_irq_save(flags);
1407 	queue = &__get_cpu_var(softnet_data);
1408 
1409 	__get_cpu_var(netdev_rx_stat).total++;
1410 	if (queue->input_pkt_queue.qlen <= netdev_max_backlog) {
1411 		if (queue->input_pkt_queue.qlen) {
1412 enqueue:
1413 			dev_hold(skb->dev);
1414 			__skb_queue_tail(&queue->input_pkt_queue, skb);
1415 			local_irq_restore(flags);
1416 			return NET_RX_SUCCESS;
1417 		}
1418 
1419 		netif_rx_schedule(&queue->backlog_dev);
1420 		goto enqueue;
1421 	}
1422 
1423 	__get_cpu_var(netdev_rx_stat).dropped++;
1424 	local_irq_restore(flags);
1425 
1426 	kfree_skb(skb);
1427 	return NET_RX_DROP;
1428 }
1429 
1430 int netif_rx_ni(struct sk_buff *skb)
1431 {
1432 	int err;
1433 
1434 	preempt_disable();
1435 	err = netif_rx(skb);
1436 	if (local_softirq_pending())
1437 		do_softirq();
1438 	preempt_enable();
1439 
1440 	return err;
1441 }
1442 
1443 EXPORT_SYMBOL(netif_rx_ni);
1444 
1445 static inline struct net_device *skb_bond(struct sk_buff *skb)
1446 {
1447 	struct net_device *dev = skb->dev;
1448 
1449 	if (dev->master) {
1450 		/*
1451 		 * On bonding slaves other than the currently active
1452 		 * slave, suppress duplicates except for 802.3ad
1453 		 * ETH_P_SLOW and alb non-mcast/bcast.
1454 		 */
1455 		if (dev->priv_flags & IFF_SLAVE_INACTIVE) {
1456 			if (dev->master->priv_flags & IFF_MASTER_ALB) {
1457 				if (skb->pkt_type != PACKET_BROADCAST &&
1458 				    skb->pkt_type != PACKET_MULTICAST)
1459 					goto keep;
1460 			}
1461 
1462 			if (dev->master->priv_flags & IFF_MASTER_8023AD &&
1463 			    skb->protocol == __constant_htons(ETH_P_SLOW))
1464 				goto keep;
1465 
1466 			kfree_skb(skb);
1467 			return NULL;
1468 		}
1469 keep:
1470 		skb->dev = dev->master;
1471 	}
1472 
1473 	return dev;
1474 }
1475 
1476 static void net_tx_action(struct softirq_action *h)
1477 {
1478 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
1479 
1480 	if (sd->completion_queue) {
1481 		struct sk_buff *clist;
1482 
1483 		local_irq_disable();
1484 		clist = sd->completion_queue;
1485 		sd->completion_queue = NULL;
1486 		local_irq_enable();
1487 
1488 		while (clist) {
1489 			struct sk_buff *skb = clist;
1490 			clist = clist->next;
1491 
1492 			BUG_TRAP(!atomic_read(&skb->users));
1493 			__kfree_skb(skb);
1494 		}
1495 	}
1496 
1497 	if (sd->output_queue) {
1498 		struct net_device *head;
1499 
1500 		local_irq_disable();
1501 		head = sd->output_queue;
1502 		sd->output_queue = NULL;
1503 		local_irq_enable();
1504 
1505 		while (head) {
1506 			struct net_device *dev = head;
1507 			head = head->next_sched;
1508 
1509 			smp_mb__before_clear_bit();
1510 			clear_bit(__LINK_STATE_SCHED, &dev->state);
1511 
1512 			if (spin_trylock(&dev->queue_lock)) {
1513 				qdisc_run(dev);
1514 				spin_unlock(&dev->queue_lock);
1515 			} else {
1516 				netif_schedule(dev);
1517 			}
1518 		}
1519 	}
1520 }
1521 
1522 static __inline__ int deliver_skb(struct sk_buff *skb,
1523 				  struct packet_type *pt_prev,
1524 				  struct net_device *orig_dev)
1525 {
1526 	atomic_inc(&skb->users);
1527 	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
1528 }
1529 
1530 #if defined(CONFIG_BRIDGE) || defined (CONFIG_BRIDGE_MODULE)
1531 int (*br_handle_frame_hook)(struct net_bridge_port *p, struct sk_buff **pskb);
1532 struct net_bridge;
1533 struct net_bridge_fdb_entry *(*br_fdb_get_hook)(struct net_bridge *br,
1534 						unsigned char *addr);
1535 void (*br_fdb_put_hook)(struct net_bridge_fdb_entry *ent);
1536 
1537 static __inline__ int handle_bridge(struct sk_buff **pskb,
1538 				    struct packet_type **pt_prev, int *ret,
1539 				    struct net_device *orig_dev)
1540 {
1541 	struct net_bridge_port *port;
1542 
1543 	if ((*pskb)->pkt_type == PACKET_LOOPBACK ||
1544 	    (port = rcu_dereference((*pskb)->dev->br_port)) == NULL)
1545 		return 0;
1546 
1547 	if (*pt_prev) {
1548 		*ret = deliver_skb(*pskb, *pt_prev, orig_dev);
1549 		*pt_prev = NULL;
1550 	}
1551 
1552 	return br_handle_frame_hook(port, pskb);
1553 }
1554 #else
1555 #define handle_bridge(skb, pt_prev, ret, orig_dev)	(0)
1556 #endif
1557 
1558 #ifdef CONFIG_NET_CLS_ACT
1559 /* TODO: Maybe we should just force sch_ingress to be compiled in
1560  * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
1561  * a compare and 2 stores extra right now if we dont have it on
1562  * but have CONFIG_NET_CLS_ACT
1563  * NOTE: This doesnt stop any functionality; if you dont have
1564  * the ingress scheduler, you just cant add policies on ingress.
1565  *
1566  */
1567 static int ing_filter(struct sk_buff *skb)
1568 {
1569 	struct Qdisc *q;
1570 	struct net_device *dev = skb->dev;
1571 	int result = TC_ACT_OK;
1572 
1573 	if (dev->qdisc_ingress) {
1574 		__u32 ttl = (__u32) G_TC_RTTL(skb->tc_verd);
1575 		if (MAX_RED_LOOP < ttl++) {
1576 			printk("Redir loop detected Dropping packet (%s->%s)\n",
1577 				skb->input_dev->name, skb->dev->name);
1578 			return TC_ACT_SHOT;
1579 		}
1580 
1581 		skb->tc_verd = SET_TC_RTTL(skb->tc_verd,ttl);
1582 
1583 		skb->tc_verd = SET_TC_AT(skb->tc_verd,AT_INGRESS);
1584 
1585 		spin_lock(&dev->ingress_lock);
1586 		if ((q = dev->qdisc_ingress) != NULL)
1587 			result = q->enqueue(skb, q);
1588 		spin_unlock(&dev->ingress_lock);
1589 
1590 	}
1591 
1592 	return result;
1593 }
1594 #endif
1595 
1596 int netif_receive_skb(struct sk_buff *skb)
1597 {
1598 	struct packet_type *ptype, *pt_prev;
1599 	struct net_device *orig_dev;
1600 	int ret = NET_RX_DROP;
1601 	unsigned short type;
1602 
1603 	/* if we've gotten here through NAPI, check netpoll */
1604 	if (skb->dev->poll && netpoll_rx(skb))
1605 		return NET_RX_DROP;
1606 
1607 	if (!skb->tstamp.off_sec)
1608 		net_timestamp(skb);
1609 
1610 	if (!skb->input_dev)
1611 		skb->input_dev = skb->dev;
1612 
1613 	orig_dev = skb_bond(skb);
1614 
1615 	if (!orig_dev)
1616 		return NET_RX_DROP;
1617 
1618 	__get_cpu_var(netdev_rx_stat).total++;
1619 
1620 	skb->h.raw = skb->nh.raw = skb->data;
1621 	skb->mac_len = skb->nh.raw - skb->mac.raw;
1622 
1623 	pt_prev = NULL;
1624 
1625 	rcu_read_lock();
1626 
1627 #ifdef CONFIG_NET_CLS_ACT
1628 	if (skb->tc_verd & TC_NCLS) {
1629 		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
1630 		goto ncls;
1631 	}
1632 #endif
1633 
1634 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
1635 		if (!ptype->dev || ptype->dev == skb->dev) {
1636 			if (pt_prev)
1637 				ret = deliver_skb(skb, pt_prev, orig_dev);
1638 			pt_prev = ptype;
1639 		}
1640 	}
1641 
1642 #ifdef CONFIG_NET_CLS_ACT
1643 	if (pt_prev) {
1644 		ret = deliver_skb(skb, pt_prev, orig_dev);
1645 		pt_prev = NULL; /* noone else should process this after*/
1646 	} else {
1647 		skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
1648 	}
1649 
1650 	ret = ing_filter(skb);
1651 
1652 	if (ret == TC_ACT_SHOT || (ret == TC_ACT_STOLEN)) {
1653 		kfree_skb(skb);
1654 		goto out;
1655 	}
1656 
1657 	skb->tc_verd = 0;
1658 ncls:
1659 #endif
1660 
1661 	handle_diverter(skb);
1662 
1663 	if (handle_bridge(&skb, &pt_prev, &ret, orig_dev))
1664 		goto out;
1665 
1666 	type = skb->protocol;
1667 	list_for_each_entry_rcu(ptype, &ptype_base[ntohs(type)&15], list) {
1668 		if (ptype->type == type &&
1669 		    (!ptype->dev || ptype->dev == skb->dev)) {
1670 			if (pt_prev)
1671 				ret = deliver_skb(skb, pt_prev, orig_dev);
1672 			pt_prev = ptype;
1673 		}
1674 	}
1675 
1676 	if (pt_prev) {
1677 		ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
1678 	} else {
1679 		kfree_skb(skb);
1680 		/* Jamal, now you will not able to escape explaining
1681 		 * me how you were going to use this. :-)
1682 		 */
1683 		ret = NET_RX_DROP;
1684 	}
1685 
1686 out:
1687 	rcu_read_unlock();
1688 	return ret;
1689 }
1690 
1691 static int process_backlog(struct net_device *backlog_dev, int *budget)
1692 {
1693 	int work = 0;
1694 	int quota = min(backlog_dev->quota, *budget);
1695 	struct softnet_data *queue = &__get_cpu_var(softnet_data);
1696 	unsigned long start_time = jiffies;
1697 
1698 	backlog_dev->weight = weight_p;
1699 	for (;;) {
1700 		struct sk_buff *skb;
1701 		struct net_device *dev;
1702 
1703 		local_irq_disable();
1704 		skb = __skb_dequeue(&queue->input_pkt_queue);
1705 		if (!skb)
1706 			goto job_done;
1707 		local_irq_enable();
1708 
1709 		dev = skb->dev;
1710 
1711 		netif_receive_skb(skb);
1712 
1713 		dev_put(dev);
1714 
1715 		work++;
1716 
1717 		if (work >= quota || jiffies - start_time > 1)
1718 			break;
1719 
1720 	}
1721 
1722 	backlog_dev->quota -= work;
1723 	*budget -= work;
1724 	return -1;
1725 
1726 job_done:
1727 	backlog_dev->quota -= work;
1728 	*budget -= work;
1729 
1730 	list_del(&backlog_dev->poll_list);
1731 	smp_mb__before_clear_bit();
1732 	netif_poll_enable(backlog_dev);
1733 
1734 	local_irq_enable();
1735 	return 0;
1736 }
1737 
1738 static void net_rx_action(struct softirq_action *h)
1739 {
1740 	struct softnet_data *queue = &__get_cpu_var(softnet_data);
1741 	unsigned long start_time = jiffies;
1742 	int budget = netdev_budget;
1743 	void *have;
1744 
1745 	local_irq_disable();
1746 
1747 	while (!list_empty(&queue->poll_list)) {
1748 		struct net_device *dev;
1749 
1750 		if (budget <= 0 || jiffies - start_time > 1)
1751 			goto softnet_break;
1752 
1753 		local_irq_enable();
1754 
1755 		dev = list_entry(queue->poll_list.next,
1756 				 struct net_device, poll_list);
1757 		have = netpoll_poll_lock(dev);
1758 
1759 		if (dev->quota <= 0 || dev->poll(dev, &budget)) {
1760 			netpoll_poll_unlock(have);
1761 			local_irq_disable();
1762 			list_del(&dev->poll_list);
1763 			list_add_tail(&dev->poll_list, &queue->poll_list);
1764 			if (dev->quota < 0)
1765 				dev->quota += dev->weight;
1766 			else
1767 				dev->quota = dev->weight;
1768 		} else {
1769 			netpoll_poll_unlock(have);
1770 			dev_put(dev);
1771 			local_irq_disable();
1772 		}
1773 	}
1774 out:
1775 	local_irq_enable();
1776 	return;
1777 
1778 softnet_break:
1779 	__get_cpu_var(netdev_rx_stat).time_squeeze++;
1780 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
1781 	goto out;
1782 }
1783 
1784 static gifconf_func_t * gifconf_list [NPROTO];
1785 
1786 /**
1787  *	register_gifconf	-	register a SIOCGIF handler
1788  *	@family: Address family
1789  *	@gifconf: Function handler
1790  *
1791  *	Register protocol dependent address dumping routines. The handler
1792  *	that is passed must not be freed or reused until it has been replaced
1793  *	by another handler.
1794  */
1795 int register_gifconf(unsigned int family, gifconf_func_t * gifconf)
1796 {
1797 	if (family >= NPROTO)
1798 		return -EINVAL;
1799 	gifconf_list[family] = gifconf;
1800 	return 0;
1801 }
1802 
1803 
1804 /*
1805  *	Map an interface index to its name (SIOCGIFNAME)
1806  */
1807 
1808 /*
1809  *	We need this ioctl for efficient implementation of the
1810  *	if_indextoname() function required by the IPv6 API.  Without
1811  *	it, we would have to search all the interfaces to find a
1812  *	match.  --pb
1813  */
1814 
1815 static int dev_ifname(struct ifreq __user *arg)
1816 {
1817 	struct net_device *dev;
1818 	struct ifreq ifr;
1819 
1820 	/*
1821 	 *	Fetch the caller's info block.
1822 	 */
1823 
1824 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
1825 		return -EFAULT;
1826 
1827 	read_lock(&dev_base_lock);
1828 	dev = __dev_get_by_index(ifr.ifr_ifindex);
1829 	if (!dev) {
1830 		read_unlock(&dev_base_lock);
1831 		return -ENODEV;
1832 	}
1833 
1834 	strcpy(ifr.ifr_name, dev->name);
1835 	read_unlock(&dev_base_lock);
1836 
1837 	if (copy_to_user(arg, &ifr, sizeof(struct ifreq)))
1838 		return -EFAULT;
1839 	return 0;
1840 }
1841 
1842 /*
1843  *	Perform a SIOCGIFCONF call. This structure will change
1844  *	size eventually, and there is nothing I can do about it.
1845  *	Thus we will need a 'compatibility mode'.
1846  */
1847 
1848 static int dev_ifconf(char __user *arg)
1849 {
1850 	struct ifconf ifc;
1851 	struct net_device *dev;
1852 	char __user *pos;
1853 	int len;
1854 	int total;
1855 	int i;
1856 
1857 	/*
1858 	 *	Fetch the caller's info block.
1859 	 */
1860 
1861 	if (copy_from_user(&ifc, arg, sizeof(struct ifconf)))
1862 		return -EFAULT;
1863 
1864 	pos = ifc.ifc_buf;
1865 	len = ifc.ifc_len;
1866 
1867 	/*
1868 	 *	Loop over the interfaces, and write an info block for each.
1869 	 */
1870 
1871 	total = 0;
1872 	for (dev = dev_base; dev; dev = dev->next) {
1873 		for (i = 0; i < NPROTO; i++) {
1874 			if (gifconf_list[i]) {
1875 				int done;
1876 				if (!pos)
1877 					done = gifconf_list[i](dev, NULL, 0);
1878 				else
1879 					done = gifconf_list[i](dev, pos + total,
1880 							       len - total);
1881 				if (done < 0)
1882 					return -EFAULT;
1883 				total += done;
1884 			}
1885 		}
1886   	}
1887 
1888 	/*
1889 	 *	All done.  Write the updated control block back to the caller.
1890 	 */
1891 	ifc.ifc_len = total;
1892 
1893 	/*
1894 	 * 	Both BSD and Solaris return 0 here, so we do too.
1895 	 */
1896 	return copy_to_user(arg, &ifc, sizeof(struct ifconf)) ? -EFAULT : 0;
1897 }
1898 
1899 #ifdef CONFIG_PROC_FS
1900 /*
1901  *	This is invoked by the /proc filesystem handler to display a device
1902  *	in detail.
1903  */
1904 static __inline__ struct net_device *dev_get_idx(loff_t pos)
1905 {
1906 	struct net_device *dev;
1907 	loff_t i;
1908 
1909 	for (i = 0, dev = dev_base; dev && i < pos; ++i, dev = dev->next);
1910 
1911 	return i == pos ? dev : NULL;
1912 }
1913 
1914 void *dev_seq_start(struct seq_file *seq, loff_t *pos)
1915 {
1916 	read_lock(&dev_base_lock);
1917 	return *pos ? dev_get_idx(*pos - 1) : SEQ_START_TOKEN;
1918 }
1919 
1920 void *dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1921 {
1922 	++*pos;
1923 	return v == SEQ_START_TOKEN ? dev_base : ((struct net_device *)v)->next;
1924 }
1925 
1926 void dev_seq_stop(struct seq_file *seq, void *v)
1927 {
1928 	read_unlock(&dev_base_lock);
1929 }
1930 
1931 static void dev_seq_printf_stats(struct seq_file *seq, struct net_device *dev)
1932 {
1933 	if (dev->get_stats) {
1934 		struct net_device_stats *stats = dev->get_stats(dev);
1935 
1936 		seq_printf(seq, "%6s:%8lu %7lu %4lu %4lu %4lu %5lu %10lu %9lu "
1937 				"%8lu %7lu %4lu %4lu %4lu %5lu %7lu %10lu\n",
1938 			   dev->name, stats->rx_bytes, stats->rx_packets,
1939 			   stats->rx_errors,
1940 			   stats->rx_dropped + stats->rx_missed_errors,
1941 			   stats->rx_fifo_errors,
1942 			   stats->rx_length_errors + stats->rx_over_errors +
1943 			     stats->rx_crc_errors + stats->rx_frame_errors,
1944 			   stats->rx_compressed, stats->multicast,
1945 			   stats->tx_bytes, stats->tx_packets,
1946 			   stats->tx_errors, stats->tx_dropped,
1947 			   stats->tx_fifo_errors, stats->collisions,
1948 			   stats->tx_carrier_errors +
1949 			     stats->tx_aborted_errors +
1950 			     stats->tx_window_errors +
1951 			     stats->tx_heartbeat_errors,
1952 			   stats->tx_compressed);
1953 	} else
1954 		seq_printf(seq, "%6s: No statistics available.\n", dev->name);
1955 }
1956 
1957 /*
1958  *	Called from the PROCfs module. This now uses the new arbitrary sized
1959  *	/proc/net interface to create /proc/net/dev
1960  */
1961 static int dev_seq_show(struct seq_file *seq, void *v)
1962 {
1963 	if (v == SEQ_START_TOKEN)
1964 		seq_puts(seq, "Inter-|   Receive                            "
1965 			      "                    |  Transmit\n"
1966 			      " face |bytes    packets errs drop fifo frame "
1967 			      "compressed multicast|bytes    packets errs "
1968 			      "drop fifo colls carrier compressed\n");
1969 	else
1970 		dev_seq_printf_stats(seq, v);
1971 	return 0;
1972 }
1973 
1974 static struct netif_rx_stats *softnet_get_online(loff_t *pos)
1975 {
1976 	struct netif_rx_stats *rc = NULL;
1977 
1978 	while (*pos < NR_CPUS)
1979 	       	if (cpu_online(*pos)) {
1980 			rc = &per_cpu(netdev_rx_stat, *pos);
1981 			break;
1982 		} else
1983 			++*pos;
1984 	return rc;
1985 }
1986 
1987 static void *softnet_seq_start(struct seq_file *seq, loff_t *pos)
1988 {
1989 	return softnet_get_online(pos);
1990 }
1991 
1992 static void *softnet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1993 {
1994 	++*pos;
1995 	return softnet_get_online(pos);
1996 }
1997 
1998 static void softnet_seq_stop(struct seq_file *seq, void *v)
1999 {
2000 }
2001 
2002 static int softnet_seq_show(struct seq_file *seq, void *v)
2003 {
2004 	struct netif_rx_stats *s = v;
2005 
2006 	seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x %08x\n",
2007 		   s->total, s->dropped, s->time_squeeze, 0,
2008 		   0, 0, 0, 0, /* was fastroute */
2009 		   s->cpu_collision );
2010 	return 0;
2011 }
2012 
2013 static struct seq_operations dev_seq_ops = {
2014 	.start = dev_seq_start,
2015 	.next  = dev_seq_next,
2016 	.stop  = dev_seq_stop,
2017 	.show  = dev_seq_show,
2018 };
2019 
2020 static int dev_seq_open(struct inode *inode, struct file *file)
2021 {
2022 	return seq_open(file, &dev_seq_ops);
2023 }
2024 
2025 static struct file_operations dev_seq_fops = {
2026 	.owner	 = THIS_MODULE,
2027 	.open    = dev_seq_open,
2028 	.read    = seq_read,
2029 	.llseek  = seq_lseek,
2030 	.release = seq_release,
2031 };
2032 
2033 static struct seq_operations softnet_seq_ops = {
2034 	.start = softnet_seq_start,
2035 	.next  = softnet_seq_next,
2036 	.stop  = softnet_seq_stop,
2037 	.show  = softnet_seq_show,
2038 };
2039 
2040 static int softnet_seq_open(struct inode *inode, struct file *file)
2041 {
2042 	return seq_open(file, &softnet_seq_ops);
2043 }
2044 
2045 static struct file_operations softnet_seq_fops = {
2046 	.owner	 = THIS_MODULE,
2047 	.open    = softnet_seq_open,
2048 	.read    = seq_read,
2049 	.llseek  = seq_lseek,
2050 	.release = seq_release,
2051 };
2052 
2053 #ifdef CONFIG_WIRELESS_EXT
2054 extern int wireless_proc_init(void);
2055 #else
2056 #define wireless_proc_init() 0
2057 #endif
2058 
2059 static int __init dev_proc_init(void)
2060 {
2061 	int rc = -ENOMEM;
2062 
2063 	if (!proc_net_fops_create("dev", S_IRUGO, &dev_seq_fops))
2064 		goto out;
2065 	if (!proc_net_fops_create("softnet_stat", S_IRUGO, &softnet_seq_fops))
2066 		goto out_dev;
2067 	if (wireless_proc_init())
2068 		goto out_softnet;
2069 	rc = 0;
2070 out:
2071 	return rc;
2072 out_softnet:
2073 	proc_net_remove("softnet_stat");
2074 out_dev:
2075 	proc_net_remove("dev");
2076 	goto out;
2077 }
2078 #else
2079 #define dev_proc_init() 0
2080 #endif	/* CONFIG_PROC_FS */
2081 
2082 
2083 /**
2084  *	netdev_set_master	-	set up master/slave pair
2085  *	@slave: slave device
2086  *	@master: new master device
2087  *
2088  *	Changes the master device of the slave. Pass %NULL to break the
2089  *	bonding. The caller must hold the RTNL semaphore. On a failure
2090  *	a negative errno code is returned. On success the reference counts
2091  *	are adjusted, %RTM_NEWLINK is sent to the routing socket and the
2092  *	function returns zero.
2093  */
2094 int netdev_set_master(struct net_device *slave, struct net_device *master)
2095 {
2096 	struct net_device *old = slave->master;
2097 
2098 	ASSERT_RTNL();
2099 
2100 	if (master) {
2101 		if (old)
2102 			return -EBUSY;
2103 		dev_hold(master);
2104 	}
2105 
2106 	slave->master = master;
2107 
2108 	synchronize_net();
2109 
2110 	if (old)
2111 		dev_put(old);
2112 
2113 	if (master)
2114 		slave->flags |= IFF_SLAVE;
2115 	else
2116 		slave->flags &= ~IFF_SLAVE;
2117 
2118 	rtmsg_ifinfo(RTM_NEWLINK, slave, IFF_SLAVE);
2119 	return 0;
2120 }
2121 
2122 /**
2123  *	dev_set_promiscuity	- update promiscuity count on a device
2124  *	@dev: device
2125  *	@inc: modifier
2126  *
2127  *	Add or remove promsicuity from a device. While the count in the device
2128  *	remains above zero the interface remains promiscuous. Once it hits zero
2129  *	the device reverts back to normal filtering operation. A negative inc
2130  *	value is used to drop promiscuity on the device.
2131  */
2132 void dev_set_promiscuity(struct net_device *dev, int inc)
2133 {
2134 	unsigned short old_flags = dev->flags;
2135 
2136 	if ((dev->promiscuity += inc) == 0)
2137 		dev->flags &= ~IFF_PROMISC;
2138 	else
2139 		dev->flags |= IFF_PROMISC;
2140 	if (dev->flags != old_flags) {
2141 		dev_mc_upload(dev);
2142 		printk(KERN_INFO "device %s %s promiscuous mode\n",
2143 		       dev->name, (dev->flags & IFF_PROMISC) ? "entered" :
2144 		       					       "left");
2145 	}
2146 }
2147 
2148 /**
2149  *	dev_set_allmulti	- update allmulti count on a device
2150  *	@dev: device
2151  *	@inc: modifier
2152  *
2153  *	Add or remove reception of all multicast frames to a device. While the
2154  *	count in the device remains above zero the interface remains listening
2155  *	to all interfaces. Once it hits zero the device reverts back to normal
2156  *	filtering operation. A negative @inc value is used to drop the counter
2157  *	when releasing a resource needing all multicasts.
2158  */
2159 
2160 void dev_set_allmulti(struct net_device *dev, int inc)
2161 {
2162 	unsigned short old_flags = dev->flags;
2163 
2164 	dev->flags |= IFF_ALLMULTI;
2165 	if ((dev->allmulti += inc) == 0)
2166 		dev->flags &= ~IFF_ALLMULTI;
2167 	if (dev->flags ^ old_flags)
2168 		dev_mc_upload(dev);
2169 }
2170 
2171 unsigned dev_get_flags(const struct net_device *dev)
2172 {
2173 	unsigned flags;
2174 
2175 	flags = (dev->flags & ~(IFF_PROMISC |
2176 				IFF_ALLMULTI |
2177 				IFF_RUNNING)) |
2178 		(dev->gflags & (IFF_PROMISC |
2179 				IFF_ALLMULTI));
2180 
2181 	if (netif_running(dev) && netif_carrier_ok(dev))
2182 		flags |= IFF_RUNNING;
2183 
2184 	return flags;
2185 }
2186 
2187 int dev_change_flags(struct net_device *dev, unsigned flags)
2188 {
2189 	int ret;
2190 	int old_flags = dev->flags;
2191 
2192 	/*
2193 	 *	Set the flags on our device.
2194 	 */
2195 
2196 	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
2197 			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
2198 			       IFF_AUTOMEDIA)) |
2199 		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
2200 				    IFF_ALLMULTI));
2201 
2202 	/*
2203 	 *	Load in the correct multicast list now the flags have changed.
2204 	 */
2205 
2206 	dev_mc_upload(dev);
2207 
2208 	/*
2209 	 *	Have we downed the interface. We handle IFF_UP ourselves
2210 	 *	according to user attempts to set it, rather than blindly
2211 	 *	setting it.
2212 	 */
2213 
2214 	ret = 0;
2215 	if ((old_flags ^ flags) & IFF_UP) {	/* Bit is different  ? */
2216 		ret = ((old_flags & IFF_UP) ? dev_close : dev_open)(dev);
2217 
2218 		if (!ret)
2219 			dev_mc_upload(dev);
2220 	}
2221 
2222 	if (dev->flags & IFF_UP &&
2223 	    ((old_flags ^ dev->flags) &~ (IFF_UP | IFF_PROMISC | IFF_ALLMULTI |
2224 					  IFF_VOLATILE)))
2225 		notifier_call_chain(&netdev_chain, NETDEV_CHANGE, dev);
2226 
2227 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
2228 		int inc = (flags & IFF_PROMISC) ? +1 : -1;
2229 		dev->gflags ^= IFF_PROMISC;
2230 		dev_set_promiscuity(dev, inc);
2231 	}
2232 
2233 	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
2234 	   is important. Some (broken) drivers set IFF_PROMISC, when
2235 	   IFF_ALLMULTI is requested not asking us and not reporting.
2236 	 */
2237 	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
2238 		int inc = (flags & IFF_ALLMULTI) ? +1 : -1;
2239 		dev->gflags ^= IFF_ALLMULTI;
2240 		dev_set_allmulti(dev, inc);
2241 	}
2242 
2243 	if (old_flags ^ dev->flags)
2244 		rtmsg_ifinfo(RTM_NEWLINK, dev, old_flags ^ dev->flags);
2245 
2246 	return ret;
2247 }
2248 
2249 int dev_set_mtu(struct net_device *dev, int new_mtu)
2250 {
2251 	int err;
2252 
2253 	if (new_mtu == dev->mtu)
2254 		return 0;
2255 
2256 	/*	MTU must be positive.	 */
2257 	if (new_mtu < 0)
2258 		return -EINVAL;
2259 
2260 	if (!netif_device_present(dev))
2261 		return -ENODEV;
2262 
2263 	err = 0;
2264 	if (dev->change_mtu)
2265 		err = dev->change_mtu(dev, new_mtu);
2266 	else
2267 		dev->mtu = new_mtu;
2268 	if (!err && dev->flags & IFF_UP)
2269 		notifier_call_chain(&netdev_chain,
2270 				    NETDEV_CHANGEMTU, dev);
2271 	return err;
2272 }
2273 
2274 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
2275 {
2276 	int err;
2277 
2278 	if (!dev->set_mac_address)
2279 		return -EOPNOTSUPP;
2280 	if (sa->sa_family != dev->type)
2281 		return -EINVAL;
2282 	if (!netif_device_present(dev))
2283 		return -ENODEV;
2284 	err = dev->set_mac_address(dev, sa);
2285 	if (!err)
2286 		notifier_call_chain(&netdev_chain, NETDEV_CHANGEADDR, dev);
2287 	return err;
2288 }
2289 
2290 /*
2291  *	Perform the SIOCxIFxxx calls.
2292  */
2293 static int dev_ifsioc(struct ifreq *ifr, unsigned int cmd)
2294 {
2295 	int err;
2296 	struct net_device *dev = __dev_get_by_name(ifr->ifr_name);
2297 
2298 	if (!dev)
2299 		return -ENODEV;
2300 
2301 	switch (cmd) {
2302 		case SIOCGIFFLAGS:	/* Get interface flags */
2303 			ifr->ifr_flags = dev_get_flags(dev);
2304 			return 0;
2305 
2306 		case SIOCSIFFLAGS:	/* Set interface flags */
2307 			return dev_change_flags(dev, ifr->ifr_flags);
2308 
2309 		case SIOCGIFMETRIC:	/* Get the metric on the interface
2310 					   (currently unused) */
2311 			ifr->ifr_metric = 0;
2312 			return 0;
2313 
2314 		case SIOCSIFMETRIC:	/* Set the metric on the interface
2315 					   (currently unused) */
2316 			return -EOPNOTSUPP;
2317 
2318 		case SIOCGIFMTU:	/* Get the MTU of a device */
2319 			ifr->ifr_mtu = dev->mtu;
2320 			return 0;
2321 
2322 		case SIOCSIFMTU:	/* Set the MTU of a device */
2323 			return dev_set_mtu(dev, ifr->ifr_mtu);
2324 
2325 		case SIOCGIFHWADDR:
2326 			if (!dev->addr_len)
2327 				memset(ifr->ifr_hwaddr.sa_data, 0, sizeof ifr->ifr_hwaddr.sa_data);
2328 			else
2329 				memcpy(ifr->ifr_hwaddr.sa_data, dev->dev_addr,
2330 				       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
2331 			ifr->ifr_hwaddr.sa_family = dev->type;
2332 			return 0;
2333 
2334 		case SIOCSIFHWADDR:
2335 			return dev_set_mac_address(dev, &ifr->ifr_hwaddr);
2336 
2337 		case SIOCSIFHWBROADCAST:
2338 			if (ifr->ifr_hwaddr.sa_family != dev->type)
2339 				return -EINVAL;
2340 			memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
2341 			       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
2342 			notifier_call_chain(&netdev_chain,
2343 					    NETDEV_CHANGEADDR, dev);
2344 			return 0;
2345 
2346 		case SIOCGIFMAP:
2347 			ifr->ifr_map.mem_start = dev->mem_start;
2348 			ifr->ifr_map.mem_end   = dev->mem_end;
2349 			ifr->ifr_map.base_addr = dev->base_addr;
2350 			ifr->ifr_map.irq       = dev->irq;
2351 			ifr->ifr_map.dma       = dev->dma;
2352 			ifr->ifr_map.port      = dev->if_port;
2353 			return 0;
2354 
2355 		case SIOCSIFMAP:
2356 			if (dev->set_config) {
2357 				if (!netif_device_present(dev))
2358 					return -ENODEV;
2359 				return dev->set_config(dev, &ifr->ifr_map);
2360 			}
2361 			return -EOPNOTSUPP;
2362 
2363 		case SIOCADDMULTI:
2364 			if (!dev->set_multicast_list ||
2365 			    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
2366 				return -EINVAL;
2367 			if (!netif_device_present(dev))
2368 				return -ENODEV;
2369 			return dev_mc_add(dev, ifr->ifr_hwaddr.sa_data,
2370 					  dev->addr_len, 1);
2371 
2372 		case SIOCDELMULTI:
2373 			if (!dev->set_multicast_list ||
2374 			    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
2375 				return -EINVAL;
2376 			if (!netif_device_present(dev))
2377 				return -ENODEV;
2378 			return dev_mc_delete(dev, ifr->ifr_hwaddr.sa_data,
2379 					     dev->addr_len, 1);
2380 
2381 		case SIOCGIFINDEX:
2382 			ifr->ifr_ifindex = dev->ifindex;
2383 			return 0;
2384 
2385 		case SIOCGIFTXQLEN:
2386 			ifr->ifr_qlen = dev->tx_queue_len;
2387 			return 0;
2388 
2389 		case SIOCSIFTXQLEN:
2390 			if (ifr->ifr_qlen < 0)
2391 				return -EINVAL;
2392 			dev->tx_queue_len = ifr->ifr_qlen;
2393 			return 0;
2394 
2395 		case SIOCSIFNAME:
2396 			ifr->ifr_newname[IFNAMSIZ-1] = '\0';
2397 			return dev_change_name(dev, ifr->ifr_newname);
2398 
2399 		/*
2400 		 *	Unknown or private ioctl
2401 		 */
2402 
2403 		default:
2404 			if ((cmd >= SIOCDEVPRIVATE &&
2405 			    cmd <= SIOCDEVPRIVATE + 15) ||
2406 			    cmd == SIOCBONDENSLAVE ||
2407 			    cmd == SIOCBONDRELEASE ||
2408 			    cmd == SIOCBONDSETHWADDR ||
2409 			    cmd == SIOCBONDSLAVEINFOQUERY ||
2410 			    cmd == SIOCBONDINFOQUERY ||
2411 			    cmd == SIOCBONDCHANGEACTIVE ||
2412 			    cmd == SIOCGMIIPHY ||
2413 			    cmd == SIOCGMIIREG ||
2414 			    cmd == SIOCSMIIREG ||
2415 			    cmd == SIOCBRADDIF ||
2416 			    cmd == SIOCBRDELIF ||
2417 			    cmd == SIOCWANDEV) {
2418 				err = -EOPNOTSUPP;
2419 				if (dev->do_ioctl) {
2420 					if (netif_device_present(dev))
2421 						err = dev->do_ioctl(dev, ifr,
2422 								    cmd);
2423 					else
2424 						err = -ENODEV;
2425 				}
2426 			} else
2427 				err = -EINVAL;
2428 
2429 	}
2430 	return err;
2431 }
2432 
2433 /*
2434  *	This function handles all "interface"-type I/O control requests. The actual
2435  *	'doing' part of this is dev_ifsioc above.
2436  */
2437 
2438 /**
2439  *	dev_ioctl	-	network device ioctl
2440  *	@cmd: command to issue
2441  *	@arg: pointer to a struct ifreq in user space
2442  *
2443  *	Issue ioctl functions to devices. This is normally called by the
2444  *	user space syscall interfaces but can sometimes be useful for
2445  *	other purposes. The return value is the return from the syscall if
2446  *	positive or a negative errno code on error.
2447  */
2448 
2449 int dev_ioctl(unsigned int cmd, void __user *arg)
2450 {
2451 	struct ifreq ifr;
2452 	int ret;
2453 	char *colon;
2454 
2455 	/* One special case: SIOCGIFCONF takes ifconf argument
2456 	   and requires shared lock, because it sleeps writing
2457 	   to user space.
2458 	 */
2459 
2460 	if (cmd == SIOCGIFCONF) {
2461 		rtnl_shlock();
2462 		ret = dev_ifconf((char __user *) arg);
2463 		rtnl_shunlock();
2464 		return ret;
2465 	}
2466 	if (cmd == SIOCGIFNAME)
2467 		return dev_ifname((struct ifreq __user *)arg);
2468 
2469 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
2470 		return -EFAULT;
2471 
2472 	ifr.ifr_name[IFNAMSIZ-1] = 0;
2473 
2474 	colon = strchr(ifr.ifr_name, ':');
2475 	if (colon)
2476 		*colon = 0;
2477 
2478 	/*
2479 	 *	See which interface the caller is talking about.
2480 	 */
2481 
2482 	switch (cmd) {
2483 		/*
2484 		 *	These ioctl calls:
2485 		 *	- can be done by all.
2486 		 *	- atomic and do not require locking.
2487 		 *	- return a value
2488 		 */
2489 		case SIOCGIFFLAGS:
2490 		case SIOCGIFMETRIC:
2491 		case SIOCGIFMTU:
2492 		case SIOCGIFHWADDR:
2493 		case SIOCGIFSLAVE:
2494 		case SIOCGIFMAP:
2495 		case SIOCGIFINDEX:
2496 		case SIOCGIFTXQLEN:
2497 			dev_load(ifr.ifr_name);
2498 			read_lock(&dev_base_lock);
2499 			ret = dev_ifsioc(&ifr, cmd);
2500 			read_unlock(&dev_base_lock);
2501 			if (!ret) {
2502 				if (colon)
2503 					*colon = ':';
2504 				if (copy_to_user(arg, &ifr,
2505 						 sizeof(struct ifreq)))
2506 					ret = -EFAULT;
2507 			}
2508 			return ret;
2509 
2510 		case SIOCETHTOOL:
2511 			dev_load(ifr.ifr_name);
2512 			rtnl_lock();
2513 			ret = dev_ethtool(&ifr);
2514 			rtnl_unlock();
2515 			if (!ret) {
2516 				if (colon)
2517 					*colon = ':';
2518 				if (copy_to_user(arg, &ifr,
2519 						 sizeof(struct ifreq)))
2520 					ret = -EFAULT;
2521 			}
2522 			return ret;
2523 
2524 		/*
2525 		 *	These ioctl calls:
2526 		 *	- require superuser power.
2527 		 *	- require strict serialization.
2528 		 *	- return a value
2529 		 */
2530 		case SIOCGMIIPHY:
2531 		case SIOCGMIIREG:
2532 		case SIOCSIFNAME:
2533 			if (!capable(CAP_NET_ADMIN))
2534 				return -EPERM;
2535 			dev_load(ifr.ifr_name);
2536 			rtnl_lock();
2537 			ret = dev_ifsioc(&ifr, cmd);
2538 			rtnl_unlock();
2539 			if (!ret) {
2540 				if (colon)
2541 					*colon = ':';
2542 				if (copy_to_user(arg, &ifr,
2543 						 sizeof(struct ifreq)))
2544 					ret = -EFAULT;
2545 			}
2546 			return ret;
2547 
2548 		/*
2549 		 *	These ioctl calls:
2550 		 *	- require superuser power.
2551 		 *	- require strict serialization.
2552 		 *	- do not return a value
2553 		 */
2554 		case SIOCSIFFLAGS:
2555 		case SIOCSIFMETRIC:
2556 		case SIOCSIFMTU:
2557 		case SIOCSIFMAP:
2558 		case SIOCSIFHWADDR:
2559 		case SIOCSIFSLAVE:
2560 		case SIOCADDMULTI:
2561 		case SIOCDELMULTI:
2562 		case SIOCSIFHWBROADCAST:
2563 		case SIOCSIFTXQLEN:
2564 		case SIOCSMIIREG:
2565 		case SIOCBONDENSLAVE:
2566 		case SIOCBONDRELEASE:
2567 		case SIOCBONDSETHWADDR:
2568 		case SIOCBONDCHANGEACTIVE:
2569 		case SIOCBRADDIF:
2570 		case SIOCBRDELIF:
2571 			if (!capable(CAP_NET_ADMIN))
2572 				return -EPERM;
2573 			/* fall through */
2574 		case SIOCBONDSLAVEINFOQUERY:
2575 		case SIOCBONDINFOQUERY:
2576 			dev_load(ifr.ifr_name);
2577 			rtnl_lock();
2578 			ret = dev_ifsioc(&ifr, cmd);
2579 			rtnl_unlock();
2580 			return ret;
2581 
2582 		case SIOCGIFMEM:
2583 			/* Get the per device memory space. We can add this but
2584 			 * currently do not support it */
2585 		case SIOCSIFMEM:
2586 			/* Set the per device memory buffer space.
2587 			 * Not applicable in our case */
2588 		case SIOCSIFLINK:
2589 			return -EINVAL;
2590 
2591 		/*
2592 		 *	Unknown or private ioctl.
2593 		 */
2594 		default:
2595 			if (cmd == SIOCWANDEV ||
2596 			    (cmd >= SIOCDEVPRIVATE &&
2597 			     cmd <= SIOCDEVPRIVATE + 15)) {
2598 				dev_load(ifr.ifr_name);
2599 				rtnl_lock();
2600 				ret = dev_ifsioc(&ifr, cmd);
2601 				rtnl_unlock();
2602 				if (!ret && copy_to_user(arg, &ifr,
2603 							 sizeof(struct ifreq)))
2604 					ret = -EFAULT;
2605 				return ret;
2606 			}
2607 #ifdef CONFIG_WIRELESS_EXT
2608 			/* Take care of Wireless Extensions */
2609 			if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) {
2610 				/* If command is `set a parameter', or
2611 				 * `get the encoding parameters', check if
2612 				 * the user has the right to do it */
2613 				if (IW_IS_SET(cmd) || cmd == SIOCGIWENCODE) {
2614 					if (!capable(CAP_NET_ADMIN))
2615 						return -EPERM;
2616 				}
2617 				dev_load(ifr.ifr_name);
2618 				rtnl_lock();
2619 				/* Follow me in net/core/wireless.c */
2620 				ret = wireless_process_ioctl(&ifr, cmd);
2621 				rtnl_unlock();
2622 				if (IW_IS_GET(cmd) &&
2623 				    copy_to_user(arg, &ifr,
2624 					    	 sizeof(struct ifreq)))
2625 					ret = -EFAULT;
2626 				return ret;
2627 			}
2628 #endif	/* CONFIG_WIRELESS_EXT */
2629 			return -EINVAL;
2630 	}
2631 }
2632 
2633 
2634 /**
2635  *	dev_new_index	-	allocate an ifindex
2636  *
2637  *	Returns a suitable unique value for a new device interface
2638  *	number.  The caller must hold the rtnl semaphore or the
2639  *	dev_base_lock to be sure it remains unique.
2640  */
2641 static int dev_new_index(void)
2642 {
2643 	static int ifindex;
2644 	for (;;) {
2645 		if (++ifindex <= 0)
2646 			ifindex = 1;
2647 		if (!__dev_get_by_index(ifindex))
2648 			return ifindex;
2649 	}
2650 }
2651 
2652 static int dev_boot_phase = 1;
2653 
2654 /* Delayed registration/unregisteration */
2655 static DEFINE_SPINLOCK(net_todo_list_lock);
2656 static struct list_head net_todo_list = LIST_HEAD_INIT(net_todo_list);
2657 
2658 static inline void net_set_todo(struct net_device *dev)
2659 {
2660 	spin_lock(&net_todo_list_lock);
2661 	list_add_tail(&dev->todo_list, &net_todo_list);
2662 	spin_unlock(&net_todo_list_lock);
2663 }
2664 
2665 /**
2666  *	register_netdevice	- register a network device
2667  *	@dev: device to register
2668  *
2669  *	Take a completed network device structure and add it to the kernel
2670  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
2671  *	chain. 0 is returned on success. A negative errno code is returned
2672  *	on a failure to set up the device, or if the name is a duplicate.
2673  *
2674  *	Callers must hold the rtnl semaphore. You may want
2675  *	register_netdev() instead of this.
2676  *
2677  *	BUGS:
2678  *	The locking appears insufficient to guarantee two parallel registers
2679  *	will not get the same name.
2680  */
2681 
2682 int register_netdevice(struct net_device *dev)
2683 {
2684 	struct hlist_head *head;
2685 	struct hlist_node *p;
2686 	int ret;
2687 
2688 	BUG_ON(dev_boot_phase);
2689 	ASSERT_RTNL();
2690 
2691 	/* When net_device's are persistent, this will be fatal. */
2692 	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
2693 
2694 	spin_lock_init(&dev->queue_lock);
2695 	spin_lock_init(&dev->xmit_lock);
2696 	dev->xmit_lock_owner = -1;
2697 #ifdef CONFIG_NET_CLS_ACT
2698 	spin_lock_init(&dev->ingress_lock);
2699 #endif
2700 
2701 	ret = alloc_divert_blk(dev);
2702 	if (ret)
2703 		goto out;
2704 
2705 	dev->iflink = -1;
2706 
2707 	/* Init, if this function is available */
2708 	if (dev->init) {
2709 		ret = dev->init(dev);
2710 		if (ret) {
2711 			if (ret > 0)
2712 				ret = -EIO;
2713 			goto out_err;
2714 		}
2715 	}
2716 
2717 	if (!dev_valid_name(dev->name)) {
2718 		ret = -EINVAL;
2719 		goto out_err;
2720 	}
2721 
2722 	dev->ifindex = dev_new_index();
2723 	if (dev->iflink == -1)
2724 		dev->iflink = dev->ifindex;
2725 
2726 	/* Check for existence of name */
2727 	head = dev_name_hash(dev->name);
2728 	hlist_for_each(p, head) {
2729 		struct net_device *d
2730 			= hlist_entry(p, struct net_device, name_hlist);
2731 		if (!strncmp(d->name, dev->name, IFNAMSIZ)) {
2732 			ret = -EEXIST;
2733  			goto out_err;
2734 		}
2735  	}
2736 
2737 	/* Fix illegal SG+CSUM combinations. */
2738 	if ((dev->features & NETIF_F_SG) &&
2739 	    !(dev->features & (NETIF_F_IP_CSUM |
2740 			       NETIF_F_NO_CSUM |
2741 			       NETIF_F_HW_CSUM))) {
2742 		printk("%s: Dropping NETIF_F_SG since no checksum feature.\n",
2743 		       dev->name);
2744 		dev->features &= ~NETIF_F_SG;
2745 	}
2746 
2747 	/* TSO requires that SG is present as well. */
2748 	if ((dev->features & NETIF_F_TSO) &&
2749 	    !(dev->features & NETIF_F_SG)) {
2750 		printk("%s: Dropping NETIF_F_TSO since no SG feature.\n",
2751 		       dev->name);
2752 		dev->features &= ~NETIF_F_TSO;
2753 	}
2754 	if (dev->features & NETIF_F_UFO) {
2755 		if (!(dev->features & NETIF_F_HW_CSUM)) {
2756 			printk(KERN_ERR "%s: Dropping NETIF_F_UFO since no "
2757 					"NETIF_F_HW_CSUM feature.\n",
2758 							dev->name);
2759 			dev->features &= ~NETIF_F_UFO;
2760 		}
2761 		if (!(dev->features & NETIF_F_SG)) {
2762 			printk(KERN_ERR "%s: Dropping NETIF_F_UFO since no "
2763 					"NETIF_F_SG feature.\n",
2764 					dev->name);
2765 			dev->features &= ~NETIF_F_UFO;
2766 		}
2767 	}
2768 
2769 	/*
2770 	 *	nil rebuild_header routine,
2771 	 *	that should be never called and used as just bug trap.
2772 	 */
2773 
2774 	if (!dev->rebuild_header)
2775 		dev->rebuild_header = default_rebuild_header;
2776 
2777 	/*
2778 	 *	Default initial state at registry is that the
2779 	 *	device is present.
2780 	 */
2781 
2782 	set_bit(__LINK_STATE_PRESENT, &dev->state);
2783 
2784 	dev->next = NULL;
2785 	dev_init_scheduler(dev);
2786 	write_lock_bh(&dev_base_lock);
2787 	*dev_tail = dev;
2788 	dev_tail = &dev->next;
2789 	hlist_add_head(&dev->name_hlist, head);
2790 	hlist_add_head(&dev->index_hlist, dev_index_hash(dev->ifindex));
2791 	dev_hold(dev);
2792 	dev->reg_state = NETREG_REGISTERING;
2793 	write_unlock_bh(&dev_base_lock);
2794 
2795 	/* Notify protocols, that a new device appeared. */
2796 	notifier_call_chain(&netdev_chain, NETDEV_REGISTER, dev);
2797 
2798 	/* Finish registration after unlock */
2799 	net_set_todo(dev);
2800 	ret = 0;
2801 
2802 out:
2803 	return ret;
2804 out_err:
2805 	free_divert_blk(dev);
2806 	goto out;
2807 }
2808 
2809 /**
2810  *	register_netdev	- register a network device
2811  *	@dev: device to register
2812  *
2813  *	Take a completed network device structure and add it to the kernel
2814  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
2815  *	chain. 0 is returned on success. A negative errno code is returned
2816  *	on a failure to set up the device, or if the name is a duplicate.
2817  *
2818  *	This is a wrapper around register_netdev that takes the rtnl semaphore
2819  *	and expands the device name if you passed a format string to
2820  *	alloc_netdev.
2821  */
2822 int register_netdev(struct net_device *dev)
2823 {
2824 	int err;
2825 
2826 	rtnl_lock();
2827 
2828 	/*
2829 	 * If the name is a format string the caller wants us to do a
2830 	 * name allocation.
2831 	 */
2832 	if (strchr(dev->name, '%')) {
2833 		err = dev_alloc_name(dev, dev->name);
2834 		if (err < 0)
2835 			goto out;
2836 	}
2837 
2838 	/*
2839 	 * Back compatibility hook. Kill this one in 2.5
2840 	 */
2841 	if (dev->name[0] == 0 || dev->name[0] == ' ') {
2842 		err = dev_alloc_name(dev, "eth%d");
2843 		if (err < 0)
2844 			goto out;
2845 	}
2846 
2847 	err = register_netdevice(dev);
2848 out:
2849 	rtnl_unlock();
2850 	return err;
2851 }
2852 EXPORT_SYMBOL(register_netdev);
2853 
2854 /*
2855  * netdev_wait_allrefs - wait until all references are gone.
2856  *
2857  * This is called when unregistering network devices.
2858  *
2859  * Any protocol or device that holds a reference should register
2860  * for netdevice notification, and cleanup and put back the
2861  * reference if they receive an UNREGISTER event.
2862  * We can get stuck here if buggy protocols don't correctly
2863  * call dev_put.
2864  */
2865 static void netdev_wait_allrefs(struct net_device *dev)
2866 {
2867 	unsigned long rebroadcast_time, warning_time;
2868 
2869 	rebroadcast_time = warning_time = jiffies;
2870 	while (atomic_read(&dev->refcnt) != 0) {
2871 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
2872 			rtnl_shlock();
2873 
2874 			/* Rebroadcast unregister notification */
2875 			notifier_call_chain(&netdev_chain,
2876 					    NETDEV_UNREGISTER, dev);
2877 
2878 			if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
2879 				     &dev->state)) {
2880 				/* We must not have linkwatch events
2881 				 * pending on unregister. If this
2882 				 * happens, we simply run the queue
2883 				 * unscheduled, resulting in a noop
2884 				 * for this device.
2885 				 */
2886 				linkwatch_run_queue();
2887 			}
2888 
2889 			rtnl_shunlock();
2890 
2891 			rebroadcast_time = jiffies;
2892 		}
2893 
2894 		msleep(250);
2895 
2896 		if (time_after(jiffies, warning_time + 10 * HZ)) {
2897 			printk(KERN_EMERG "unregister_netdevice: "
2898 			       "waiting for %s to become free. Usage "
2899 			       "count = %d\n",
2900 			       dev->name, atomic_read(&dev->refcnt));
2901 			warning_time = jiffies;
2902 		}
2903 	}
2904 }
2905 
2906 /* The sequence is:
2907  *
2908  *	rtnl_lock();
2909  *	...
2910  *	register_netdevice(x1);
2911  *	register_netdevice(x2);
2912  *	...
2913  *	unregister_netdevice(y1);
2914  *	unregister_netdevice(y2);
2915  *      ...
2916  *	rtnl_unlock();
2917  *	free_netdev(y1);
2918  *	free_netdev(y2);
2919  *
2920  * We are invoked by rtnl_unlock() after it drops the semaphore.
2921  * This allows us to deal with problems:
2922  * 1) We can create/delete sysfs objects which invoke hotplug
2923  *    without deadlocking with linkwatch via keventd.
2924  * 2) Since we run with the RTNL semaphore not held, we can sleep
2925  *    safely in order to wait for the netdev refcnt to drop to zero.
2926  */
2927 static DECLARE_MUTEX(net_todo_run_mutex);
2928 void netdev_run_todo(void)
2929 {
2930 	struct list_head list = LIST_HEAD_INIT(list);
2931 	int err;
2932 
2933 
2934 	/* Need to guard against multiple cpu's getting out of order. */
2935 	down(&net_todo_run_mutex);
2936 
2937 	/* Not safe to do outside the semaphore.  We must not return
2938 	 * until all unregister events invoked by the local processor
2939 	 * have been completed (either by this todo run, or one on
2940 	 * another cpu).
2941 	 */
2942 	if (list_empty(&net_todo_list))
2943 		goto out;
2944 
2945 	/* Snapshot list, allow later requests */
2946 	spin_lock(&net_todo_list_lock);
2947 	list_splice_init(&net_todo_list, &list);
2948 	spin_unlock(&net_todo_list_lock);
2949 
2950 	while (!list_empty(&list)) {
2951 		struct net_device *dev
2952 			= list_entry(list.next, struct net_device, todo_list);
2953 		list_del(&dev->todo_list);
2954 
2955 		switch(dev->reg_state) {
2956 		case NETREG_REGISTERING:
2957 			err = netdev_register_sysfs(dev);
2958 			if (err)
2959 				printk(KERN_ERR "%s: failed sysfs registration (%d)\n",
2960 				       dev->name, err);
2961 			dev->reg_state = NETREG_REGISTERED;
2962 			break;
2963 
2964 		case NETREG_UNREGISTERING:
2965 			netdev_unregister_sysfs(dev);
2966 			dev->reg_state = NETREG_UNREGISTERED;
2967 
2968 			netdev_wait_allrefs(dev);
2969 
2970 			/* paranoia */
2971 			BUG_ON(atomic_read(&dev->refcnt));
2972 			BUG_TRAP(!dev->ip_ptr);
2973 			BUG_TRAP(!dev->ip6_ptr);
2974 			BUG_TRAP(!dev->dn_ptr);
2975 
2976 
2977 			/* It must be the very last action,
2978 			 * after this 'dev' may point to freed up memory.
2979 			 */
2980 			if (dev->destructor)
2981 				dev->destructor(dev);
2982 			break;
2983 
2984 		default:
2985 			printk(KERN_ERR "network todo '%s' but state %d\n",
2986 			       dev->name, dev->reg_state);
2987 			break;
2988 		}
2989 	}
2990 
2991 out:
2992 	up(&net_todo_run_mutex);
2993 }
2994 
2995 /**
2996  *	alloc_netdev - allocate network device
2997  *	@sizeof_priv:	size of private data to allocate space for
2998  *	@name:		device name format string
2999  *	@setup:		callback to initialize device
3000  *
3001  *	Allocates a struct net_device with private data area for driver use
3002  *	and performs basic initialization.
3003  */
3004 struct net_device *alloc_netdev(int sizeof_priv, const char *name,
3005 		void (*setup)(struct net_device *))
3006 {
3007 	void *p;
3008 	struct net_device *dev;
3009 	int alloc_size;
3010 
3011 	/* ensure 32-byte alignment of both the device and private area */
3012 	alloc_size = (sizeof(*dev) + NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST;
3013 	alloc_size += sizeof_priv + NETDEV_ALIGN_CONST;
3014 
3015 	p = kmalloc(alloc_size, GFP_KERNEL);
3016 	if (!p) {
3017 		printk(KERN_ERR "alloc_dev: Unable to allocate device.\n");
3018 		return NULL;
3019 	}
3020 	memset(p, 0, alloc_size);
3021 
3022 	dev = (struct net_device *)
3023 		(((long)p + NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST);
3024 	dev->padded = (char *)dev - (char *)p;
3025 
3026 	if (sizeof_priv)
3027 		dev->priv = netdev_priv(dev);
3028 
3029 	setup(dev);
3030 	strcpy(dev->name, name);
3031 	return dev;
3032 }
3033 EXPORT_SYMBOL(alloc_netdev);
3034 
3035 /**
3036  *	free_netdev - free network device
3037  *	@dev: device
3038  *
3039  *	This function does the last stage of destroying an allocated device
3040  * 	interface. The reference to the device object is released.
3041  *	If this is the last reference then it will be freed.
3042  */
3043 void free_netdev(struct net_device *dev)
3044 {
3045 #ifdef CONFIG_SYSFS
3046 	/*  Compatiablity with error handling in drivers */
3047 	if (dev->reg_state == NETREG_UNINITIALIZED) {
3048 		kfree((char *)dev - dev->padded);
3049 		return;
3050 	}
3051 
3052 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
3053 	dev->reg_state = NETREG_RELEASED;
3054 
3055 	/* will free via class release */
3056 	class_device_put(&dev->class_dev);
3057 #else
3058 	kfree((char *)dev - dev->padded);
3059 #endif
3060 }
3061 
3062 /* Synchronize with packet receive processing. */
3063 void synchronize_net(void)
3064 {
3065 	might_sleep();
3066 	synchronize_rcu();
3067 }
3068 
3069 /**
3070  *	unregister_netdevice - remove device from the kernel
3071  *	@dev: device
3072  *
3073  *	This function shuts down a device interface and removes it
3074  *	from the kernel tables. On success 0 is returned, on a failure
3075  *	a negative errno code is returned.
3076  *
3077  *	Callers must hold the rtnl semaphore.  You may want
3078  *	unregister_netdev() instead of this.
3079  */
3080 
3081 int unregister_netdevice(struct net_device *dev)
3082 {
3083 	struct net_device *d, **dp;
3084 
3085 	BUG_ON(dev_boot_phase);
3086 	ASSERT_RTNL();
3087 
3088 	/* Some devices call without registering for initialization unwind. */
3089 	if (dev->reg_state == NETREG_UNINITIALIZED) {
3090 		printk(KERN_DEBUG "unregister_netdevice: device %s/%p never "
3091 				  "was registered\n", dev->name, dev);
3092 		return -ENODEV;
3093 	}
3094 
3095 	BUG_ON(dev->reg_state != NETREG_REGISTERED);
3096 
3097 	/* If device is running, close it first. */
3098 	if (dev->flags & IFF_UP)
3099 		dev_close(dev);
3100 
3101 	/* And unlink it from device chain. */
3102 	for (dp = &dev_base; (d = *dp) != NULL; dp = &d->next) {
3103 		if (d == dev) {
3104 			write_lock_bh(&dev_base_lock);
3105 			hlist_del(&dev->name_hlist);
3106 			hlist_del(&dev->index_hlist);
3107 			if (dev_tail == &dev->next)
3108 				dev_tail = dp;
3109 			*dp = d->next;
3110 			write_unlock_bh(&dev_base_lock);
3111 			break;
3112 		}
3113 	}
3114 	if (!d) {
3115 		printk(KERN_ERR "unregister net_device: '%s' not found\n",
3116 		       dev->name);
3117 		return -ENODEV;
3118 	}
3119 
3120 	dev->reg_state = NETREG_UNREGISTERING;
3121 
3122 	synchronize_net();
3123 
3124 	/* Shutdown queueing discipline. */
3125 	dev_shutdown(dev);
3126 
3127 
3128 	/* Notify protocols, that we are about to destroy
3129 	   this device. They should clean all the things.
3130 	*/
3131 	notifier_call_chain(&netdev_chain, NETDEV_UNREGISTER, dev);
3132 
3133 	/*
3134 	 *	Flush the multicast chain
3135 	 */
3136 	dev_mc_discard(dev);
3137 
3138 	if (dev->uninit)
3139 		dev->uninit(dev);
3140 
3141 	/* Notifier chain MUST detach us from master device. */
3142 	BUG_TRAP(!dev->master);
3143 
3144 	free_divert_blk(dev);
3145 
3146 	/* Finish processing unregister after unlock */
3147 	net_set_todo(dev);
3148 
3149 	synchronize_net();
3150 
3151 	dev_put(dev);
3152 	return 0;
3153 }
3154 
3155 /**
3156  *	unregister_netdev - remove device from the kernel
3157  *	@dev: device
3158  *
3159  *	This function shuts down a device interface and removes it
3160  *	from the kernel tables. On success 0 is returned, on a failure
3161  *	a negative errno code is returned.
3162  *
3163  *	This is just a wrapper for unregister_netdevice that takes
3164  *	the rtnl semaphore.  In general you want to use this and not
3165  *	unregister_netdevice.
3166  */
3167 void unregister_netdev(struct net_device *dev)
3168 {
3169 	rtnl_lock();
3170 	unregister_netdevice(dev);
3171 	rtnl_unlock();
3172 }
3173 
3174 EXPORT_SYMBOL(unregister_netdev);
3175 
3176 #ifdef CONFIG_HOTPLUG_CPU
3177 static int dev_cpu_callback(struct notifier_block *nfb,
3178 			    unsigned long action,
3179 			    void *ocpu)
3180 {
3181 	struct sk_buff **list_skb;
3182 	struct net_device **list_net;
3183 	struct sk_buff *skb;
3184 	unsigned int cpu, oldcpu = (unsigned long)ocpu;
3185 	struct softnet_data *sd, *oldsd;
3186 
3187 	if (action != CPU_DEAD)
3188 		return NOTIFY_OK;
3189 
3190 	local_irq_disable();
3191 	cpu = smp_processor_id();
3192 	sd = &per_cpu(softnet_data, cpu);
3193 	oldsd = &per_cpu(softnet_data, oldcpu);
3194 
3195 	/* Find end of our completion_queue. */
3196 	list_skb = &sd->completion_queue;
3197 	while (*list_skb)
3198 		list_skb = &(*list_skb)->next;
3199 	/* Append completion queue from offline CPU. */
3200 	*list_skb = oldsd->completion_queue;
3201 	oldsd->completion_queue = NULL;
3202 
3203 	/* Find end of our output_queue. */
3204 	list_net = &sd->output_queue;
3205 	while (*list_net)
3206 		list_net = &(*list_net)->next_sched;
3207 	/* Append output queue from offline CPU. */
3208 	*list_net = oldsd->output_queue;
3209 	oldsd->output_queue = NULL;
3210 
3211 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3212 	local_irq_enable();
3213 
3214 	/* Process offline CPU's input_pkt_queue */
3215 	while ((skb = __skb_dequeue(&oldsd->input_pkt_queue)))
3216 		netif_rx(skb);
3217 
3218 	return NOTIFY_OK;
3219 }
3220 #endif /* CONFIG_HOTPLUG_CPU */
3221 
3222 
3223 /*
3224  *	Initialize the DEV module. At boot time this walks the device list and
3225  *	unhooks any devices that fail to initialise (normally hardware not
3226  *	present) and leaves us with a valid list of present and active devices.
3227  *
3228  */
3229 
3230 /*
3231  *       This is called single threaded during boot, so no need
3232  *       to take the rtnl semaphore.
3233  */
3234 static int __init net_dev_init(void)
3235 {
3236 	int i, rc = -ENOMEM;
3237 
3238 	BUG_ON(!dev_boot_phase);
3239 
3240 	net_random_init();
3241 
3242 	if (dev_proc_init())
3243 		goto out;
3244 
3245 	if (netdev_sysfs_init())
3246 		goto out;
3247 
3248 	INIT_LIST_HEAD(&ptype_all);
3249 	for (i = 0; i < 16; i++)
3250 		INIT_LIST_HEAD(&ptype_base[i]);
3251 
3252 	for (i = 0; i < ARRAY_SIZE(dev_name_head); i++)
3253 		INIT_HLIST_HEAD(&dev_name_head[i]);
3254 
3255 	for (i = 0; i < ARRAY_SIZE(dev_index_head); i++)
3256 		INIT_HLIST_HEAD(&dev_index_head[i]);
3257 
3258 	/*
3259 	 *	Initialise the packet receive queues.
3260 	 */
3261 
3262 	for_each_cpu(i) {
3263 		struct softnet_data *queue;
3264 
3265 		queue = &per_cpu(softnet_data, i);
3266 		skb_queue_head_init(&queue->input_pkt_queue);
3267 		queue->completion_queue = NULL;
3268 		INIT_LIST_HEAD(&queue->poll_list);
3269 		set_bit(__LINK_STATE_START, &queue->backlog_dev.state);
3270 		queue->backlog_dev.weight = weight_p;
3271 		queue->backlog_dev.poll = process_backlog;
3272 		atomic_set(&queue->backlog_dev.refcnt, 1);
3273 	}
3274 
3275 	dev_boot_phase = 0;
3276 
3277 	open_softirq(NET_TX_SOFTIRQ, net_tx_action, NULL);
3278 	open_softirq(NET_RX_SOFTIRQ, net_rx_action, NULL);
3279 
3280 	hotcpu_notifier(dev_cpu_callback, 0);
3281 	dst_init();
3282 	dev_mcast_init();
3283 	rc = 0;
3284 out:
3285 	return rc;
3286 }
3287 
3288 subsys_initcall(net_dev_init);
3289 
3290 EXPORT_SYMBOL(__dev_get_by_index);
3291 EXPORT_SYMBOL(__dev_get_by_name);
3292 EXPORT_SYMBOL(__dev_remove_pack);
3293 EXPORT_SYMBOL(__skb_linearize);
3294 EXPORT_SYMBOL(dev_valid_name);
3295 EXPORT_SYMBOL(dev_add_pack);
3296 EXPORT_SYMBOL(dev_alloc_name);
3297 EXPORT_SYMBOL(dev_close);
3298 EXPORT_SYMBOL(dev_get_by_flags);
3299 EXPORT_SYMBOL(dev_get_by_index);
3300 EXPORT_SYMBOL(dev_get_by_name);
3301 EXPORT_SYMBOL(dev_open);
3302 EXPORT_SYMBOL(dev_queue_xmit);
3303 EXPORT_SYMBOL(dev_remove_pack);
3304 EXPORT_SYMBOL(dev_set_allmulti);
3305 EXPORT_SYMBOL(dev_set_promiscuity);
3306 EXPORT_SYMBOL(dev_change_flags);
3307 EXPORT_SYMBOL(dev_set_mtu);
3308 EXPORT_SYMBOL(dev_set_mac_address);
3309 EXPORT_SYMBOL(free_netdev);
3310 EXPORT_SYMBOL(netdev_boot_setup_check);
3311 EXPORT_SYMBOL(netdev_set_master);
3312 EXPORT_SYMBOL(netdev_state_change);
3313 EXPORT_SYMBOL(netif_receive_skb);
3314 EXPORT_SYMBOL(netif_rx);
3315 EXPORT_SYMBOL(register_gifconf);
3316 EXPORT_SYMBOL(register_netdevice);
3317 EXPORT_SYMBOL(register_netdevice_notifier);
3318 EXPORT_SYMBOL(skb_checksum_help);
3319 EXPORT_SYMBOL(synchronize_net);
3320 EXPORT_SYMBOL(unregister_netdevice);
3321 EXPORT_SYMBOL(unregister_netdevice_notifier);
3322 EXPORT_SYMBOL(net_enable_timestamp);
3323 EXPORT_SYMBOL(net_disable_timestamp);
3324 EXPORT_SYMBOL(dev_get_flags);
3325 
3326 #if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
3327 EXPORT_SYMBOL(br_handle_frame_hook);
3328 EXPORT_SYMBOL(br_fdb_get_hook);
3329 EXPORT_SYMBOL(br_fdb_put_hook);
3330 #endif
3331 
3332 #ifdef CONFIG_KMOD
3333 EXPORT_SYMBOL(dev_load);
3334 #endif
3335 
3336 EXPORT_PER_CPU_SYMBOL(softnet_data);
3337