xref: /linux/net/core/dev.c (revision 776cfebb430c7b22c208b1b17add97f354d97cab)
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, <bir7@leland.Stanford.Edu>
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/config.h>
79 #include <linux/cpu.h>
80 #include <linux/types.h>
81 #include <linux/kernel.h>
82 #include <linux/sched.h>
83 #include <linux/string.h>
84 #include <linux/mm.h>
85 #include <linux/socket.h>
86 #include <linux/sockios.h>
87 #include <linux/errno.h>
88 #include <linux/interrupt.h>
89 #include <linux/if_ether.h>
90 #include <linux/netdevice.h>
91 #include <linux/etherdevice.h>
92 #include <linux/notifier.h>
93 #include <linux/skbuff.h>
94 #include <net/sock.h>
95 #include <linux/rtnetlink.h>
96 #include <linux/proc_fs.h>
97 #include <linux/seq_file.h>
98 #include <linux/stat.h>
99 #include <linux/if_bridge.h>
100 #include <linux/divert.h>
101 #include <net/dst.h>
102 #include <net/pkt_sched.h>
103 #include <net/checksum.h>
104 #include <linux/highmem.h>
105 #include <linux/init.h>
106 #include <linux/kmod.h>
107 #include <linux/module.h>
108 #include <linux/kallsyms.h>
109 #include <linux/netpoll.h>
110 #include <linux/rcupdate.h>
111 #include <linux/delay.h>
112 #ifdef CONFIG_NET_RADIO
113 #include <linux/wireless.h>		/* Note : will define WIRELESS_EXT */
114 #include <net/iw_handler.h>
115 #endif	/* CONFIG_NET_RADIO */
116 #include <asm/current.h>
117 
118 /* This define, if set, will randomly drop a packet when congestion
119  * is more than moderate.  It helps fairness in the multi-interface
120  * case when one of them is a hog, but it kills performance for the
121  * single interface case so it is off now by default.
122  */
123 #undef RAND_LIE
124 
125 /* Setting this will sample the queue lengths and thus congestion
126  * via a timer instead of as each packet is received.
127  */
128 #undef OFFLINE_SAMPLE
129 
130 /*
131  *	The list of packet types we will receive (as opposed to discard)
132  *	and the routines to invoke.
133  *
134  *	Why 16. Because with 16 the only overlap we get on a hash of the
135  *	low nibble of the protocol value is RARP/SNAP/X.25.
136  *
137  *      NOTE:  That is no longer true with the addition of VLAN tags.  Not
138  *             sure which should go first, but I bet it won't make much
139  *             difference if we are running VLANs.  The good news is that
140  *             this protocol won't be in the list unless compiled in, so
141  *             the average user (w/out VLANs) will not be adversly affected.
142  *             --BLG
143  *
144  *		0800	IP
145  *		8100    802.1Q VLAN
146  *		0001	802.3
147  *		0002	AX.25
148  *		0004	802.2
149  *		8035	RARP
150  *		0005	SNAP
151  *		0805	X.25
152  *		0806	ARP
153  *		8137	IPX
154  *		0009	Localtalk
155  *		86DD	IPv6
156  */
157 
158 static DEFINE_SPINLOCK(ptype_lock);
159 static struct list_head ptype_base[16];	/* 16 way hashed list */
160 static struct list_head ptype_all;		/* Taps */
161 
162 #ifdef OFFLINE_SAMPLE
163 static void sample_queue(unsigned long dummy);
164 static struct timer_list samp_timer = TIMER_INITIALIZER(sample_queue, 0, 0);
165 #endif
166 
167 /*
168  * The @dev_base list is protected by @dev_base_lock and the rtln
169  * semaphore.
170  *
171  * Pure readers hold dev_base_lock for reading.
172  *
173  * Writers must hold the rtnl semaphore while they loop through the
174  * dev_base list, and hold dev_base_lock for writing when they do the
175  * actual updates.  This allows pure readers to access the list even
176  * while a writer is preparing to update it.
177  *
178  * To put it another way, dev_base_lock is held for writing only to
179  * protect against pure readers; the rtnl semaphore provides the
180  * protection against other writers.
181  *
182  * See, for example usages, register_netdevice() and
183  * unregister_netdevice(), which must be called with the rtnl
184  * semaphore held.
185  */
186 struct net_device *dev_base;
187 static struct net_device **dev_tail = &dev_base;
188 DEFINE_RWLOCK(dev_base_lock);
189 
190 EXPORT_SYMBOL(dev_base);
191 EXPORT_SYMBOL(dev_base_lock);
192 
193 #define NETDEV_HASHBITS	8
194 static struct hlist_head dev_name_head[1<<NETDEV_HASHBITS];
195 static struct hlist_head dev_index_head[1<<NETDEV_HASHBITS];
196 
197 static inline struct hlist_head *dev_name_hash(const char *name)
198 {
199 	unsigned hash = full_name_hash(name, strnlen(name, IFNAMSIZ));
200 	return &dev_name_head[hash & ((1<<NETDEV_HASHBITS)-1)];
201 }
202 
203 static inline struct hlist_head *dev_index_hash(int ifindex)
204 {
205 	return &dev_index_head[ifindex & ((1<<NETDEV_HASHBITS)-1)];
206 }
207 
208 /*
209  *	Our notifier list
210  */
211 
212 static struct notifier_block *netdev_chain;
213 
214 /*
215  *	Device drivers call our routines to queue packets here. We empty the
216  *	queue in the local softnet handler.
217  */
218 DEFINE_PER_CPU(struct softnet_data, softnet_data) = { 0, };
219 
220 #ifdef CONFIG_SYSFS
221 extern int netdev_sysfs_init(void);
222 extern int netdev_register_sysfs(struct net_device *);
223 extern void netdev_unregister_sysfs(struct net_device *);
224 #else
225 #define netdev_sysfs_init()	 	(0)
226 #define netdev_register_sysfs(dev)	(0)
227 #define	netdev_unregister_sysfs(dev)	do { } while(0)
228 #endif
229 
230 
231 /*******************************************************************************
232 
233 		Protocol management and registration routines
234 
235 *******************************************************************************/
236 
237 /*
238  *	For efficiency
239  */
240 
241 int netdev_nit;
242 
243 /*
244  *	Add a protocol ID to the list. Now that the input handler is
245  *	smarter we can dispense with all the messy stuff that used to be
246  *	here.
247  *
248  *	BEWARE!!! Protocol handlers, mangling input packets,
249  *	MUST BE last in hash buckets and checking protocol handlers
250  *	MUST start from promiscuous ptype_all chain in net_bh.
251  *	It is true now, do not change it.
252  *	Explanation follows: if protocol handler, mangling packet, will
253  *	be the first on list, it is not able to sense, that packet
254  *	is cloned and should be copied-on-write, so that it will
255  *	change it and subsequent readers will get broken packet.
256  *							--ANK (980803)
257  */
258 
259 /**
260  *	dev_add_pack - add packet handler
261  *	@pt: packet type declaration
262  *
263  *	Add a protocol handler to the networking stack. The passed &packet_type
264  *	is linked into kernel lists and may not be freed until it has been
265  *	removed from the kernel lists.
266  *
267  *	This call does not sleep therefore it can not
268  *	guarantee all CPU's that are in middle of receiving packets
269  *	will see the new packet type (until the next received packet).
270  */
271 
272 void dev_add_pack(struct packet_type *pt)
273 {
274 	int hash;
275 
276 	spin_lock_bh(&ptype_lock);
277 	if (pt->type == htons(ETH_P_ALL)) {
278 		netdev_nit++;
279 		list_add_rcu(&pt->list, &ptype_all);
280 	} else {
281 		hash = ntohs(pt->type) & 15;
282 		list_add_rcu(&pt->list, &ptype_base[hash]);
283 	}
284 	spin_unlock_bh(&ptype_lock);
285 }
286 
287 extern void linkwatch_run_queue(void);
288 
289 
290 
291 /**
292  *	__dev_remove_pack	 - remove packet handler
293  *	@pt: packet type declaration
294  *
295  *	Remove a protocol handler that was previously added to the kernel
296  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
297  *	from the kernel lists and can be freed or reused once this function
298  *	returns.
299  *
300  *      The packet type might still be in use by receivers
301  *	and must not be freed until after all the CPU's have gone
302  *	through a quiescent state.
303  */
304 void __dev_remove_pack(struct packet_type *pt)
305 {
306 	struct list_head *head;
307 	struct packet_type *pt1;
308 
309 	spin_lock_bh(&ptype_lock);
310 
311 	if (pt->type == htons(ETH_P_ALL)) {
312 		netdev_nit--;
313 		head = &ptype_all;
314 	} else
315 		head = &ptype_base[ntohs(pt->type) & 15];
316 
317 	list_for_each_entry(pt1, head, list) {
318 		if (pt == pt1) {
319 			list_del_rcu(&pt->list);
320 			goto out;
321 		}
322 	}
323 
324 	printk(KERN_WARNING "dev_remove_pack: %p not found.\n", pt);
325 out:
326 	spin_unlock_bh(&ptype_lock);
327 }
328 /**
329  *	dev_remove_pack	 - remove packet handler
330  *	@pt: packet type declaration
331  *
332  *	Remove a protocol handler that was previously added to the kernel
333  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
334  *	from the kernel lists and can be freed or reused once this function
335  *	returns.
336  *
337  *	This call sleeps to guarantee that no CPU is looking at the packet
338  *	type after return.
339  */
340 void dev_remove_pack(struct packet_type *pt)
341 {
342 	__dev_remove_pack(pt);
343 
344 	synchronize_net();
345 }
346 
347 /******************************************************************************
348 
349 		      Device Boot-time Settings Routines
350 
351 *******************************************************************************/
352 
353 /* Boot time configuration table */
354 static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX];
355 
356 /**
357  *	netdev_boot_setup_add	- add new setup entry
358  *	@name: name of the device
359  *	@map: configured settings for the device
360  *
361  *	Adds new setup entry to the dev_boot_setup list.  The function
362  *	returns 0 on error and 1 on success.  This is a generic routine to
363  *	all netdevices.
364  */
365 static int netdev_boot_setup_add(char *name, struct ifmap *map)
366 {
367 	struct netdev_boot_setup *s;
368 	int i;
369 
370 	s = dev_boot_setup;
371 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
372 		if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
373 			memset(s[i].name, 0, sizeof(s[i].name));
374 			strcpy(s[i].name, name);
375 			memcpy(&s[i].map, map, sizeof(s[i].map));
376 			break;
377 		}
378 	}
379 
380 	return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1;
381 }
382 
383 /**
384  *	netdev_boot_setup_check	- check boot time settings
385  *	@dev: the netdevice
386  *
387  * 	Check boot time settings for the device.
388  *	The found settings are set for the device to be used
389  *	later in the device probing.
390  *	Returns 0 if no settings found, 1 if they are.
391  */
392 int netdev_boot_setup_check(struct net_device *dev)
393 {
394 	struct netdev_boot_setup *s = dev_boot_setup;
395 	int i;
396 
397 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
398 		if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
399 		    !strncmp(dev->name, s[i].name, strlen(s[i].name))) {
400 			dev->irq 	= s[i].map.irq;
401 			dev->base_addr 	= s[i].map.base_addr;
402 			dev->mem_start 	= s[i].map.mem_start;
403 			dev->mem_end 	= s[i].map.mem_end;
404 			return 1;
405 		}
406 	}
407 	return 0;
408 }
409 
410 
411 /**
412  *	netdev_boot_base	- get address from boot time settings
413  *	@prefix: prefix for network device
414  *	@unit: id for network device
415  *
416  * 	Check boot time settings for the base address of device.
417  *	The found settings are set for the device to be used
418  *	later in the device probing.
419  *	Returns 0 if no settings found.
420  */
421 unsigned long netdev_boot_base(const char *prefix, int unit)
422 {
423 	const struct netdev_boot_setup *s = dev_boot_setup;
424 	char name[IFNAMSIZ];
425 	int i;
426 
427 	sprintf(name, "%s%d", prefix, unit);
428 
429 	/*
430 	 * If device already registered then return base of 1
431 	 * to indicate not to probe for this interface
432 	 */
433 	if (__dev_get_by_name(name))
434 		return 1;
435 
436 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++)
437 		if (!strcmp(name, s[i].name))
438 			return s[i].map.base_addr;
439 	return 0;
440 }
441 
442 /*
443  * Saves at boot time configured settings for any netdevice.
444  */
445 int __init netdev_boot_setup(char *str)
446 {
447 	int ints[5];
448 	struct ifmap map;
449 
450 	str = get_options(str, ARRAY_SIZE(ints), ints);
451 	if (!str || !*str)
452 		return 0;
453 
454 	/* Save settings */
455 	memset(&map, 0, sizeof(map));
456 	if (ints[0] > 0)
457 		map.irq = ints[1];
458 	if (ints[0] > 1)
459 		map.base_addr = ints[2];
460 	if (ints[0] > 2)
461 		map.mem_start = ints[3];
462 	if (ints[0] > 3)
463 		map.mem_end = ints[4];
464 
465 	/* Add new entry to the list */
466 	return netdev_boot_setup_add(str, &map);
467 }
468 
469 __setup("netdev=", netdev_boot_setup);
470 
471 /*******************************************************************************
472 
473 			    Device Interface Subroutines
474 
475 *******************************************************************************/
476 
477 /**
478  *	__dev_get_by_name	- find a device by its name
479  *	@name: name to find
480  *
481  *	Find an interface by name. Must be called under RTNL semaphore
482  *	or @dev_base_lock. If the name is found a pointer to the device
483  *	is returned. If the name is not found then %NULL is returned. The
484  *	reference counters are not incremented so the caller must be
485  *	careful with locks.
486  */
487 
488 struct net_device *__dev_get_by_name(const char *name)
489 {
490 	struct hlist_node *p;
491 
492 	hlist_for_each(p, dev_name_hash(name)) {
493 		struct net_device *dev
494 			= hlist_entry(p, struct net_device, name_hlist);
495 		if (!strncmp(dev->name, name, IFNAMSIZ))
496 			return dev;
497 	}
498 	return NULL;
499 }
500 
501 /**
502  *	dev_get_by_name		- find a device by its name
503  *	@name: name to find
504  *
505  *	Find an interface by name. This can be called from any
506  *	context and does its own locking. The returned handle has
507  *	the usage count incremented and the caller must use dev_put() to
508  *	release it when it is no longer needed. %NULL is returned if no
509  *	matching device is found.
510  */
511 
512 struct net_device *dev_get_by_name(const char *name)
513 {
514 	struct net_device *dev;
515 
516 	read_lock(&dev_base_lock);
517 	dev = __dev_get_by_name(name);
518 	if (dev)
519 		dev_hold(dev);
520 	read_unlock(&dev_base_lock);
521 	return dev;
522 }
523 
524 /**
525  *	__dev_get_by_index - find a device by its ifindex
526  *	@ifindex: index of device
527  *
528  *	Search for an interface by index. Returns %NULL if the device
529  *	is not found or a pointer to the device. The device has not
530  *	had its reference counter increased so the caller must be careful
531  *	about locking. The caller must hold either the RTNL semaphore
532  *	or @dev_base_lock.
533  */
534 
535 struct net_device *__dev_get_by_index(int ifindex)
536 {
537 	struct hlist_node *p;
538 
539 	hlist_for_each(p, dev_index_hash(ifindex)) {
540 		struct net_device *dev
541 			= hlist_entry(p, struct net_device, index_hlist);
542 		if (dev->ifindex == ifindex)
543 			return dev;
544 	}
545 	return NULL;
546 }
547 
548 
549 /**
550  *	dev_get_by_index - find a device by its ifindex
551  *	@ifindex: index of device
552  *
553  *	Search for an interface by index. Returns NULL if the device
554  *	is not found or a pointer to the device. The device returned has
555  *	had a reference added and the pointer is safe until the user calls
556  *	dev_put to indicate they have finished with it.
557  */
558 
559 struct net_device *dev_get_by_index(int ifindex)
560 {
561 	struct net_device *dev;
562 
563 	read_lock(&dev_base_lock);
564 	dev = __dev_get_by_index(ifindex);
565 	if (dev)
566 		dev_hold(dev);
567 	read_unlock(&dev_base_lock);
568 	return dev;
569 }
570 
571 /**
572  *	dev_getbyhwaddr - find a device by its hardware address
573  *	@type: media type of device
574  *	@ha: hardware address
575  *
576  *	Search for an interface by MAC address. Returns NULL if the device
577  *	is not found or a pointer to the device. The caller must hold the
578  *	rtnl semaphore. The returned device has not had its ref count increased
579  *	and the caller must therefore be careful about locking
580  *
581  *	BUGS:
582  *	If the API was consistent this would be __dev_get_by_hwaddr
583  */
584 
585 struct net_device *dev_getbyhwaddr(unsigned short type, char *ha)
586 {
587 	struct net_device *dev;
588 
589 	ASSERT_RTNL();
590 
591 	for (dev = dev_base; dev; dev = dev->next)
592 		if (dev->type == type &&
593 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
594 			break;
595 	return dev;
596 }
597 
598 struct net_device *dev_getfirstbyhwtype(unsigned short type)
599 {
600 	struct net_device *dev;
601 
602 	rtnl_lock();
603 	for (dev = dev_base; dev; dev = dev->next) {
604 		if (dev->type == type) {
605 			dev_hold(dev);
606 			break;
607 		}
608 	}
609 	rtnl_unlock();
610 	return dev;
611 }
612 
613 EXPORT_SYMBOL(dev_getfirstbyhwtype);
614 
615 /**
616  *	dev_get_by_flags - find any device with given flags
617  *	@if_flags: IFF_* values
618  *	@mask: bitmask of bits in if_flags to check
619  *
620  *	Search for any interface with the given flags. Returns NULL if a device
621  *	is not found or a pointer to the device. The device returned has
622  *	had a reference added and the pointer is safe until the user calls
623  *	dev_put to indicate they have finished with it.
624  */
625 
626 struct net_device * dev_get_by_flags(unsigned short if_flags, unsigned short mask)
627 {
628 	struct net_device *dev;
629 
630 	read_lock(&dev_base_lock);
631 	for (dev = dev_base; dev != NULL; dev = dev->next) {
632 		if (((dev->flags ^ if_flags) & mask) == 0) {
633 			dev_hold(dev);
634 			break;
635 		}
636 	}
637 	read_unlock(&dev_base_lock);
638 	return dev;
639 }
640 
641 /**
642  *	dev_valid_name - check if name is okay for network device
643  *	@name: name string
644  *
645  *	Network device names need to be valid file names to
646  *	to allow sysfs to work
647  */
648 static int dev_valid_name(const char *name)
649 {
650 	return !(*name == '\0'
651 		 || !strcmp(name, ".")
652 		 || !strcmp(name, "..")
653 		 || strchr(name, '/'));
654 }
655 
656 /**
657  *	dev_alloc_name - allocate a name for a device
658  *	@dev: device
659  *	@name: name format string
660  *
661  *	Passed a format string - eg "lt%d" it will try and find a suitable
662  *	id. Not efficient for many devices, not called a lot. The caller
663  *	must hold the dev_base or rtnl lock while allocating the name and
664  *	adding the device in order to avoid duplicates. Returns the number
665  *	of the unit assigned or a negative errno code.
666  */
667 
668 int dev_alloc_name(struct net_device *dev, const char *name)
669 {
670 	int i = 0;
671 	char buf[IFNAMSIZ];
672 	const char *p;
673 	const int max_netdevices = 8*PAGE_SIZE;
674 	long *inuse;
675 	struct net_device *d;
676 
677 	p = strnchr(name, IFNAMSIZ-1, '%');
678 	if (p) {
679 		/*
680 		 * Verify the string as this thing may have come from
681 		 * the user.  There must be either one "%d" and no other "%"
682 		 * characters.
683 		 */
684 		if (p[1] != 'd' || strchr(p + 2, '%'))
685 			return -EINVAL;
686 
687 		/* Use one page as a bit array of possible slots */
688 		inuse = (long *) get_zeroed_page(GFP_ATOMIC);
689 		if (!inuse)
690 			return -ENOMEM;
691 
692 		for (d = dev_base; d; d = d->next) {
693 			if (!sscanf(d->name, name, &i))
694 				continue;
695 			if (i < 0 || i >= max_netdevices)
696 				continue;
697 
698 			/*  avoid cases where sscanf is not exact inverse of printf */
699 			snprintf(buf, sizeof(buf), name, i);
700 			if (!strncmp(buf, d->name, IFNAMSIZ))
701 				set_bit(i, inuse);
702 		}
703 
704 		i = find_first_zero_bit(inuse, max_netdevices);
705 		free_page((unsigned long) inuse);
706 	}
707 
708 	snprintf(buf, sizeof(buf), name, i);
709 	if (!__dev_get_by_name(buf)) {
710 		strlcpy(dev->name, buf, IFNAMSIZ);
711 		return i;
712 	}
713 
714 	/* It is possible to run out of possible slots
715 	 * when the name is long and there isn't enough space left
716 	 * for the digits, or if all bits are used.
717 	 */
718 	return -ENFILE;
719 }
720 
721 
722 /**
723  *	dev_change_name - change name of a device
724  *	@dev: device
725  *	@newname: name (or format string) must be at least IFNAMSIZ
726  *
727  *	Change name of a device, can pass format strings "eth%d".
728  *	for wildcarding.
729  */
730 int dev_change_name(struct net_device *dev, char *newname)
731 {
732 	int err = 0;
733 
734 	ASSERT_RTNL();
735 
736 	if (dev->flags & IFF_UP)
737 		return -EBUSY;
738 
739 	if (!dev_valid_name(newname))
740 		return -EINVAL;
741 
742 	if (strchr(newname, '%')) {
743 		err = dev_alloc_name(dev, newname);
744 		if (err < 0)
745 			return err;
746 		strcpy(newname, dev->name);
747 	}
748 	else if (__dev_get_by_name(newname))
749 		return -EEXIST;
750 	else
751 		strlcpy(dev->name, newname, IFNAMSIZ);
752 
753 	err = class_device_rename(&dev->class_dev, dev->name);
754 	if (!err) {
755 		hlist_del(&dev->name_hlist);
756 		hlist_add_head(&dev->name_hlist, dev_name_hash(dev->name));
757 		notifier_call_chain(&netdev_chain, NETDEV_CHANGENAME, dev);
758 	}
759 
760 	return err;
761 }
762 
763 /**
764  *	netdev_state_change - device changes state
765  *	@dev: device to cause notification
766  *
767  *	Called to indicate a device has changed state. This function calls
768  *	the notifier chains for netdev_chain and sends a NEWLINK message
769  *	to the routing socket.
770  */
771 void netdev_state_change(struct net_device *dev)
772 {
773 	if (dev->flags & IFF_UP) {
774 		notifier_call_chain(&netdev_chain, NETDEV_CHANGE, dev);
775 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
776 	}
777 }
778 
779 /**
780  *	dev_load 	- load a network module
781  *	@name: name of interface
782  *
783  *	If a network interface is not present and the process has suitable
784  *	privileges this function loads the module. If module loading is not
785  *	available in this kernel then it becomes a nop.
786  */
787 
788 void dev_load(const char *name)
789 {
790 	struct net_device *dev;
791 
792 	read_lock(&dev_base_lock);
793 	dev = __dev_get_by_name(name);
794 	read_unlock(&dev_base_lock);
795 
796 	if (!dev && capable(CAP_SYS_MODULE))
797 		request_module("%s", name);
798 }
799 
800 static int default_rebuild_header(struct sk_buff *skb)
801 {
802 	printk(KERN_DEBUG "%s: default_rebuild_header called -- BUG!\n",
803 	       skb->dev ? skb->dev->name : "NULL!!!");
804 	kfree_skb(skb);
805 	return 1;
806 }
807 
808 
809 /**
810  *	dev_open	- prepare an interface for use.
811  *	@dev:	device to open
812  *
813  *	Takes a device from down to up state. The device's private open
814  *	function is invoked and then the multicast lists are loaded. Finally
815  *	the device is moved into the up state and a %NETDEV_UP message is
816  *	sent to the netdev notifier chain.
817  *
818  *	Calling this function on an active interface is a nop. On a failure
819  *	a negative errno code is returned.
820  */
821 int dev_open(struct net_device *dev)
822 {
823 	int ret = 0;
824 
825 	/*
826 	 *	Is it already up?
827 	 */
828 
829 	if (dev->flags & IFF_UP)
830 		return 0;
831 
832 	/*
833 	 *	Is it even present?
834 	 */
835 	if (!netif_device_present(dev))
836 		return -ENODEV;
837 
838 	/*
839 	 *	Call device private open method
840 	 */
841 	set_bit(__LINK_STATE_START, &dev->state);
842 	if (dev->open) {
843 		ret = dev->open(dev);
844 		if (ret)
845 			clear_bit(__LINK_STATE_START, &dev->state);
846 	}
847 
848  	/*
849 	 *	If it went open OK then:
850 	 */
851 
852 	if (!ret) {
853 		/*
854 		 *	Set the flags.
855 		 */
856 		dev->flags |= IFF_UP;
857 
858 		/*
859 		 *	Initialize multicasting status
860 		 */
861 		dev_mc_upload(dev);
862 
863 		/*
864 		 *	Wakeup transmit queue engine
865 		 */
866 		dev_activate(dev);
867 
868 		/*
869 		 *	... and announce new interface.
870 		 */
871 		notifier_call_chain(&netdev_chain, NETDEV_UP, dev);
872 	}
873 	return ret;
874 }
875 
876 /**
877  *	dev_close - shutdown an interface.
878  *	@dev: device to shutdown
879  *
880  *	This function moves an active device into down state. A
881  *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
882  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
883  *	chain.
884  */
885 int dev_close(struct net_device *dev)
886 {
887 	if (!(dev->flags & IFF_UP))
888 		return 0;
889 
890 	/*
891 	 *	Tell people we are going down, so that they can
892 	 *	prepare to death, when device is still operating.
893 	 */
894 	notifier_call_chain(&netdev_chain, NETDEV_GOING_DOWN, dev);
895 
896 	dev_deactivate(dev);
897 
898 	clear_bit(__LINK_STATE_START, &dev->state);
899 
900 	/* Synchronize to scheduled poll. We cannot touch poll list,
901 	 * it can be even on different cpu. So just clear netif_running(),
902 	 * and wait when poll really will happen. Actually, the best place
903 	 * for this is inside dev->stop() after device stopped its irq
904 	 * engine, but this requires more changes in devices. */
905 
906 	smp_mb__after_clear_bit(); /* Commit netif_running(). */
907 	while (test_bit(__LINK_STATE_RX_SCHED, &dev->state)) {
908 		/* No hurry. */
909 		current->state = TASK_INTERRUPTIBLE;
910 		schedule_timeout(1);
911 	}
912 
913 	/*
914 	 *	Call the device specific close. This cannot fail.
915 	 *	Only if device is UP
916 	 *
917 	 *	We allow it to be called even after a DETACH hot-plug
918 	 *	event.
919 	 */
920 	if (dev->stop)
921 		dev->stop(dev);
922 
923 	/*
924 	 *	Device is now down.
925 	 */
926 
927 	dev->flags &= ~IFF_UP;
928 
929 	/*
930 	 * Tell people we are down
931 	 */
932 	notifier_call_chain(&netdev_chain, NETDEV_DOWN, dev);
933 
934 	return 0;
935 }
936 
937 
938 /*
939  *	Device change register/unregister. These are not inline or static
940  *	as we export them to the world.
941  */
942 
943 /**
944  *	register_netdevice_notifier - register a network notifier block
945  *	@nb: notifier
946  *
947  *	Register a notifier to be called when network device events occur.
948  *	The notifier passed is linked into the kernel structures and must
949  *	not be reused until it has been unregistered. A negative errno code
950  *	is returned on a failure.
951  *
952  * 	When registered all registration and up events are replayed
953  *	to the new notifier to allow device to have a race free
954  *	view of the network device list.
955  */
956 
957 int register_netdevice_notifier(struct notifier_block *nb)
958 {
959 	struct net_device *dev;
960 	int err;
961 
962 	rtnl_lock();
963 	err = notifier_chain_register(&netdev_chain, nb);
964 	if (!err) {
965 		for (dev = dev_base; dev; dev = dev->next) {
966 			nb->notifier_call(nb, NETDEV_REGISTER, dev);
967 
968 			if (dev->flags & IFF_UP)
969 				nb->notifier_call(nb, NETDEV_UP, dev);
970 		}
971 	}
972 	rtnl_unlock();
973 	return err;
974 }
975 
976 /**
977  *	unregister_netdevice_notifier - unregister a network notifier block
978  *	@nb: notifier
979  *
980  *	Unregister a notifier previously registered by
981  *	register_netdevice_notifier(). The notifier is unlinked into the
982  *	kernel structures and may then be reused. A negative errno code
983  *	is returned on a failure.
984  */
985 
986 int unregister_netdevice_notifier(struct notifier_block *nb)
987 {
988 	return notifier_chain_unregister(&netdev_chain, nb);
989 }
990 
991 /**
992  *	call_netdevice_notifiers - call all network notifier blocks
993  *      @val: value passed unmodified to notifier function
994  *      @v:   pointer passed unmodified to notifier function
995  *
996  *	Call all network notifier blocks.  Parameters and return value
997  *	are as for notifier_call_chain().
998  */
999 
1000 int call_netdevice_notifiers(unsigned long val, void *v)
1001 {
1002 	return notifier_call_chain(&netdev_chain, val, v);
1003 }
1004 
1005 /* When > 0 there are consumers of rx skb time stamps */
1006 static atomic_t netstamp_needed = ATOMIC_INIT(0);
1007 
1008 void net_enable_timestamp(void)
1009 {
1010 	atomic_inc(&netstamp_needed);
1011 }
1012 
1013 void net_disable_timestamp(void)
1014 {
1015 	atomic_dec(&netstamp_needed);
1016 }
1017 
1018 static inline void net_timestamp(struct timeval *stamp)
1019 {
1020 	if (atomic_read(&netstamp_needed))
1021 		do_gettimeofday(stamp);
1022 	else {
1023 		stamp->tv_sec = 0;
1024 		stamp->tv_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 	net_timestamp(&skb->stamp);
1037 
1038 	rcu_read_lock();
1039 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
1040 		/* Never send packets back to the socket
1041 		 * they originated from - MvS (miquels@drinkel.ow.org)
1042 		 */
1043 		if ((ptype->dev == dev || !ptype->dev) &&
1044 		    (ptype->af_packet_priv == NULL ||
1045 		     (struct sock *)ptype->af_packet_priv != skb->sk)) {
1046 			struct sk_buff *skb2= skb_clone(skb, GFP_ATOMIC);
1047 			if (!skb2)
1048 				break;
1049 
1050 			/* skb->nh should be correctly
1051 			   set by sender, so that the second statement is
1052 			   just protection against buggy protocols.
1053 			 */
1054 			skb2->mac.raw = skb2->data;
1055 
1056 			if (skb2->nh.raw < skb2->data ||
1057 			    skb2->nh.raw > skb2->tail) {
1058 				if (net_ratelimit())
1059 					printk(KERN_CRIT "protocol %04x is "
1060 					       "buggy, dev %s\n",
1061 					       skb2->protocol, dev->name);
1062 				skb2->nh.raw = skb2->data;
1063 			}
1064 
1065 			skb2->h.raw = skb2->nh.raw;
1066 			skb2->pkt_type = PACKET_OUTGOING;
1067 			ptype->func(skb2, skb->dev, ptype);
1068 		}
1069 	}
1070 	rcu_read_unlock();
1071 }
1072 
1073 /*
1074  * Invalidate hardware checksum when packet is to be mangled, and
1075  * complete checksum manually on outgoing path.
1076  */
1077 int skb_checksum_help(struct sk_buff *skb, int inward)
1078 {
1079 	unsigned int csum;
1080 	int ret = 0, offset = skb->h.raw - skb->data;
1081 
1082 	if (inward) {
1083 		skb->ip_summed = CHECKSUM_NONE;
1084 		goto out;
1085 	}
1086 
1087 	if (skb_cloned(skb)) {
1088 		ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
1089 		if (ret)
1090 			goto out;
1091 	}
1092 
1093 	if (offset > (int)skb->len)
1094 		BUG();
1095 	csum = skb_checksum(skb, offset, skb->len-offset, 0);
1096 
1097 	offset = skb->tail - skb->h.raw;
1098 	if (offset <= 0)
1099 		BUG();
1100 	if (skb->csum + 2 > offset)
1101 		BUG();
1102 
1103 	*(u16*)(skb->h.raw + skb->csum) = csum_fold(csum);
1104 	skb->ip_summed = CHECKSUM_NONE;
1105 out:
1106 	return ret;
1107 }
1108 
1109 #ifdef CONFIG_HIGHMEM
1110 /* Actually, we should eliminate this check as soon as we know, that:
1111  * 1. IOMMU is present and allows to map all the memory.
1112  * 2. No high memory really exists on this machine.
1113  */
1114 
1115 static inline int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
1116 {
1117 	int i;
1118 
1119 	if (dev->features & NETIF_F_HIGHDMA)
1120 		return 0;
1121 
1122 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
1123 		if (PageHighMem(skb_shinfo(skb)->frags[i].page))
1124 			return 1;
1125 
1126 	return 0;
1127 }
1128 #else
1129 #define illegal_highdma(dev, skb)	(0)
1130 #endif
1131 
1132 extern void skb_release_data(struct sk_buff *);
1133 
1134 /* Keep head the same: replace data */
1135 int __skb_linearize(struct sk_buff *skb, int gfp_mask)
1136 {
1137 	unsigned int size;
1138 	u8 *data;
1139 	long offset;
1140 	struct skb_shared_info *ninfo;
1141 	int headerlen = skb->data - skb->head;
1142 	int expand = (skb->tail + skb->data_len) - skb->end;
1143 
1144 	if (skb_shared(skb))
1145 		BUG();
1146 
1147 	if (expand <= 0)
1148 		expand = 0;
1149 
1150 	size = skb->end - skb->head + expand;
1151 	size = SKB_DATA_ALIGN(size);
1152 	data = kmalloc(size + sizeof(struct skb_shared_info), gfp_mask);
1153 	if (!data)
1154 		return -ENOMEM;
1155 
1156 	/* Copy entire thing */
1157 	if (skb_copy_bits(skb, -headerlen, data, headerlen + skb->len))
1158 		BUG();
1159 
1160 	/* Set up shinfo */
1161 	ninfo = (struct skb_shared_info*)(data + size);
1162 	atomic_set(&ninfo->dataref, 1);
1163 	ninfo->tso_size = skb_shinfo(skb)->tso_size;
1164 	ninfo->tso_segs = skb_shinfo(skb)->tso_segs;
1165 	ninfo->nr_frags = 0;
1166 	ninfo->frag_list = NULL;
1167 
1168 	/* Offset between the two in bytes */
1169 	offset = data - skb->head;
1170 
1171 	/* Free old data. */
1172 	skb_release_data(skb);
1173 
1174 	skb->head = data;
1175 	skb->end  = data + size;
1176 
1177 	/* Set up new pointers */
1178 	skb->h.raw   += offset;
1179 	skb->nh.raw  += offset;
1180 	skb->mac.raw += offset;
1181 	skb->tail    += offset;
1182 	skb->data    += offset;
1183 
1184 	/* We are no longer a clone, even if we were. */
1185 	skb->cloned    = 0;
1186 
1187 	skb->tail     += skb->data_len;
1188 	skb->data_len  = 0;
1189 	return 0;
1190 }
1191 
1192 #define HARD_TX_LOCK(dev, cpu) {			\
1193 	if ((dev->features & NETIF_F_LLTX) == 0) {	\
1194 		spin_lock(&dev->xmit_lock);		\
1195 		dev->xmit_lock_owner = cpu;		\
1196 	}						\
1197 }
1198 
1199 #define HARD_TX_UNLOCK(dev) {				\
1200 	if ((dev->features & NETIF_F_LLTX) == 0) {	\
1201 		dev->xmit_lock_owner = -1;		\
1202 		spin_unlock(&dev->xmit_lock);		\
1203 	}						\
1204 }
1205 
1206 /**
1207  *	dev_queue_xmit - transmit a buffer
1208  *	@skb: buffer to transmit
1209  *
1210  *	Queue a buffer for transmission to a network device. The caller must
1211  *	have set the device and priority and built the buffer before calling
1212  *	this function. The function can be called from an interrupt.
1213  *
1214  *	A negative errno code is returned on a failure. A success does not
1215  *	guarantee the frame will be transmitted as it may be dropped due
1216  *	to congestion or traffic shaping.
1217  *
1218  * -----------------------------------------------------------------------------------
1219  *      I notice this method can also return errors from the queue disciplines,
1220  *      including NET_XMIT_DROP, which is a positive value.  So, errors can also
1221  *      be positive.
1222  *
1223  *      Regardless of the return value, the skb is consumed, so it is currently
1224  *      difficult to retry a send to this method.  (You can bump the ref count
1225  *      before sending to hold a reference for retry if you are careful.)
1226  *
1227  *      When calling this method, interrupts MUST be enabled.  This is because
1228  *      the BH enable code must have IRQs enabled so that it will not deadlock.
1229  *          --BLG
1230  */
1231 
1232 int dev_queue_xmit(struct sk_buff *skb)
1233 {
1234 	struct net_device *dev = skb->dev;
1235 	struct Qdisc *q;
1236 	int rc = -ENOMEM;
1237 
1238 	if (skb_shinfo(skb)->frag_list &&
1239 	    !(dev->features & NETIF_F_FRAGLIST) &&
1240 	    __skb_linearize(skb, GFP_ATOMIC))
1241 		goto out_kfree_skb;
1242 
1243 	/* Fragmented skb is linearized if device does not support SG,
1244 	 * or if at least one of fragments is in highmem and device
1245 	 * does not support DMA from it.
1246 	 */
1247 	if (skb_shinfo(skb)->nr_frags &&
1248 	    (!(dev->features & NETIF_F_SG) || illegal_highdma(dev, skb)) &&
1249 	    __skb_linearize(skb, GFP_ATOMIC))
1250 		goto out_kfree_skb;
1251 
1252 	/* If packet is not checksummed and device does not support
1253 	 * checksumming for this protocol, complete checksumming here.
1254 	 */
1255 	if (skb->ip_summed == CHECKSUM_HW &&
1256 	    (!(dev->features & (NETIF_F_HW_CSUM | NETIF_F_NO_CSUM)) &&
1257 	     (!(dev->features & NETIF_F_IP_CSUM) ||
1258 	      skb->protocol != htons(ETH_P_IP))))
1259 	      	if (skb_checksum_help(skb, 0))
1260 	      		goto out_kfree_skb;
1261 
1262 	/* Disable soft irqs for various locks below. Also
1263 	 * stops preemption for RCU.
1264 	 */
1265 	local_bh_disable();
1266 
1267 	/* Updates of qdisc are serialized by queue_lock.
1268 	 * The struct Qdisc which is pointed to by qdisc is now a
1269 	 * rcu structure - it may be accessed without acquiring
1270 	 * a lock (but the structure may be stale.) The freeing of the
1271 	 * qdisc will be deferred until it's known that there are no
1272 	 * more references to it.
1273 	 *
1274 	 * If the qdisc has an enqueue function, we still need to
1275 	 * hold the queue_lock before calling it, since queue_lock
1276 	 * also serializes access to the device queue.
1277 	 */
1278 
1279 	q = rcu_dereference(dev->qdisc);
1280 #ifdef CONFIG_NET_CLS_ACT
1281 	skb->tc_verd = SET_TC_AT(skb->tc_verd,AT_EGRESS);
1282 #endif
1283 	if (q->enqueue) {
1284 		/* Grab device queue */
1285 		spin_lock(&dev->queue_lock);
1286 
1287 		rc = q->enqueue(skb, q);
1288 
1289 		qdisc_run(dev);
1290 
1291 		spin_unlock(&dev->queue_lock);
1292 		rc = rc == NET_XMIT_BYPASS ? NET_XMIT_SUCCESS : rc;
1293 		goto out;
1294 	}
1295 
1296 	/* The device has no queue. Common case for software devices:
1297 	   loopback, all the sorts of tunnels...
1298 
1299 	   Really, it is unlikely that xmit_lock protection is necessary here.
1300 	   (f.e. loopback and IP tunnels are clean ignoring statistics
1301 	   counters.)
1302 	   However, it is possible, that they rely on protection
1303 	   made by us here.
1304 
1305 	   Check this and shot the lock. It is not prone from deadlocks.
1306 	   Either shot noqueue qdisc, it is even simpler 8)
1307 	 */
1308 	if (dev->flags & IFF_UP) {
1309 		int cpu = smp_processor_id(); /* ok because BHs are off */
1310 
1311 		if (dev->xmit_lock_owner != cpu) {
1312 
1313 			HARD_TX_LOCK(dev, cpu);
1314 
1315 			if (!netif_queue_stopped(dev)) {
1316 				if (netdev_nit)
1317 					dev_queue_xmit_nit(skb, dev);
1318 
1319 				rc = 0;
1320 				if (!dev->hard_start_xmit(skb, dev)) {
1321 					HARD_TX_UNLOCK(dev);
1322 					goto out;
1323 				}
1324 			}
1325 			HARD_TX_UNLOCK(dev);
1326 			if (net_ratelimit())
1327 				printk(KERN_CRIT "Virtual device %s asks to "
1328 				       "queue packet!\n", dev->name);
1329 		} else {
1330 			/* Recursion is detected! It is possible,
1331 			 * unfortunately */
1332 			if (net_ratelimit())
1333 				printk(KERN_CRIT "Dead loop on virtual device "
1334 				       "%s, fix it urgently!\n", dev->name);
1335 		}
1336 	}
1337 
1338 	rc = -ENETDOWN;
1339 	local_bh_enable();
1340 
1341 out_kfree_skb:
1342 	kfree_skb(skb);
1343 	return rc;
1344 out:
1345 	local_bh_enable();
1346 	return rc;
1347 }
1348 
1349 
1350 /*=======================================================================
1351 			Receiver routines
1352   =======================================================================*/
1353 
1354 int netdev_max_backlog = 300;
1355 int weight_p = 64;            /* old backlog weight */
1356 /* These numbers are selected based on intuition and some
1357  * experimentatiom, if you have more scientific way of doing this
1358  * please go ahead and fix things.
1359  */
1360 int no_cong_thresh = 10;
1361 int no_cong = 20;
1362 int lo_cong = 100;
1363 int mod_cong = 290;
1364 
1365 DEFINE_PER_CPU(struct netif_rx_stats, netdev_rx_stat) = { 0, };
1366 
1367 
1368 static void get_sample_stats(int cpu)
1369 {
1370 #ifdef RAND_LIE
1371 	unsigned long rd;
1372 	int rq;
1373 #endif
1374 	struct softnet_data *sd = &per_cpu(softnet_data, cpu);
1375 	int blog = sd->input_pkt_queue.qlen;
1376 	int avg_blog = sd->avg_blog;
1377 
1378 	avg_blog = (avg_blog >> 1) + (blog >> 1);
1379 
1380 	if (avg_blog > mod_cong) {
1381 		/* Above moderate congestion levels. */
1382 		sd->cng_level = NET_RX_CN_HIGH;
1383 #ifdef RAND_LIE
1384 		rd = net_random();
1385 		rq = rd % netdev_max_backlog;
1386 		if (rq < avg_blog) /* unlucky bastard */
1387 			sd->cng_level = NET_RX_DROP;
1388 #endif
1389 	} else if (avg_blog > lo_cong) {
1390 		sd->cng_level = NET_RX_CN_MOD;
1391 #ifdef RAND_LIE
1392 		rd = net_random();
1393 		rq = rd % netdev_max_backlog;
1394 			if (rq < avg_blog) /* unlucky bastard */
1395 				sd->cng_level = NET_RX_CN_HIGH;
1396 #endif
1397 	} else if (avg_blog > no_cong)
1398 		sd->cng_level = NET_RX_CN_LOW;
1399 	else  /* no congestion */
1400 		sd->cng_level = NET_RX_SUCCESS;
1401 
1402 	sd->avg_blog = avg_blog;
1403 }
1404 
1405 #ifdef OFFLINE_SAMPLE
1406 static void sample_queue(unsigned long dummy)
1407 {
1408 /* 10 ms 0r 1ms -- i don't care -- JHS */
1409 	int next_tick = 1;
1410 	int cpu = smp_processor_id();
1411 
1412 	get_sample_stats(cpu);
1413 	next_tick += jiffies;
1414 	mod_timer(&samp_timer, next_tick);
1415 }
1416 #endif
1417 
1418 
1419 /**
1420  *	netif_rx	-	post buffer to the network code
1421  *	@skb: buffer to post
1422  *
1423  *	This function receives a packet from a device driver and queues it for
1424  *	the upper (protocol) levels to process.  It always succeeds. The buffer
1425  *	may be dropped during processing for congestion control or by the
1426  *	protocol layers.
1427  *
1428  *	return values:
1429  *	NET_RX_SUCCESS	(no congestion)
1430  *	NET_RX_CN_LOW   (low congestion)
1431  *	NET_RX_CN_MOD   (moderate congestion)
1432  *	NET_RX_CN_HIGH  (high congestion)
1433  *	NET_RX_DROP     (packet was dropped)
1434  *
1435  */
1436 
1437 int netif_rx(struct sk_buff *skb)
1438 {
1439 	int this_cpu;
1440 	struct softnet_data *queue;
1441 	unsigned long flags;
1442 
1443 	/* if netpoll wants it, pretend we never saw it */
1444 	if (netpoll_rx(skb))
1445 		return NET_RX_DROP;
1446 
1447 	if (!skb->stamp.tv_sec)
1448 		net_timestamp(&skb->stamp);
1449 
1450 	/*
1451 	 * The code is rearranged so that the path is the most
1452 	 * short when CPU is congested, but is still operating.
1453 	 */
1454 	local_irq_save(flags);
1455 	this_cpu = smp_processor_id();
1456 	queue = &__get_cpu_var(softnet_data);
1457 
1458 	__get_cpu_var(netdev_rx_stat).total++;
1459 	if (queue->input_pkt_queue.qlen <= netdev_max_backlog) {
1460 		if (queue->input_pkt_queue.qlen) {
1461 			if (queue->throttle)
1462 				goto drop;
1463 
1464 enqueue:
1465 			dev_hold(skb->dev);
1466 			__skb_queue_tail(&queue->input_pkt_queue, skb);
1467 #ifndef OFFLINE_SAMPLE
1468 			get_sample_stats(this_cpu);
1469 #endif
1470 			local_irq_restore(flags);
1471 			return queue->cng_level;
1472 		}
1473 
1474 		if (queue->throttle)
1475 			queue->throttle = 0;
1476 
1477 		netif_rx_schedule(&queue->backlog_dev);
1478 		goto enqueue;
1479 	}
1480 
1481 	if (!queue->throttle) {
1482 		queue->throttle = 1;
1483 		__get_cpu_var(netdev_rx_stat).throttled++;
1484 	}
1485 
1486 drop:
1487 	__get_cpu_var(netdev_rx_stat).dropped++;
1488 	local_irq_restore(flags);
1489 
1490 	kfree_skb(skb);
1491 	return NET_RX_DROP;
1492 }
1493 
1494 int netif_rx_ni(struct sk_buff *skb)
1495 {
1496 	int err;
1497 
1498 	preempt_disable();
1499 	err = netif_rx(skb);
1500 	if (local_softirq_pending())
1501 		do_softirq();
1502 	preempt_enable();
1503 
1504 	return err;
1505 }
1506 
1507 EXPORT_SYMBOL(netif_rx_ni);
1508 
1509 static __inline__ void skb_bond(struct sk_buff *skb)
1510 {
1511 	struct net_device *dev = skb->dev;
1512 
1513 	if (dev->master) {
1514 		skb->real_dev = skb->dev;
1515 		skb->dev = dev->master;
1516 	}
1517 }
1518 
1519 static void net_tx_action(struct softirq_action *h)
1520 {
1521 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
1522 
1523 	if (sd->completion_queue) {
1524 		struct sk_buff *clist;
1525 
1526 		local_irq_disable();
1527 		clist = sd->completion_queue;
1528 		sd->completion_queue = NULL;
1529 		local_irq_enable();
1530 
1531 		while (clist) {
1532 			struct sk_buff *skb = clist;
1533 			clist = clist->next;
1534 
1535 			BUG_TRAP(!atomic_read(&skb->users));
1536 			__kfree_skb(skb);
1537 		}
1538 	}
1539 
1540 	if (sd->output_queue) {
1541 		struct net_device *head;
1542 
1543 		local_irq_disable();
1544 		head = sd->output_queue;
1545 		sd->output_queue = NULL;
1546 		local_irq_enable();
1547 
1548 		while (head) {
1549 			struct net_device *dev = head;
1550 			head = head->next_sched;
1551 
1552 			smp_mb__before_clear_bit();
1553 			clear_bit(__LINK_STATE_SCHED, &dev->state);
1554 
1555 			if (spin_trylock(&dev->queue_lock)) {
1556 				qdisc_run(dev);
1557 				spin_unlock(&dev->queue_lock);
1558 			} else {
1559 				netif_schedule(dev);
1560 			}
1561 		}
1562 	}
1563 }
1564 
1565 static __inline__ int deliver_skb(struct sk_buff *skb,
1566 				  struct packet_type *pt_prev)
1567 {
1568 	atomic_inc(&skb->users);
1569 	return pt_prev->func(skb, skb->dev, pt_prev);
1570 }
1571 
1572 #if defined(CONFIG_BRIDGE) || defined (CONFIG_BRIDGE_MODULE)
1573 int (*br_handle_frame_hook)(struct net_bridge_port *p, struct sk_buff **pskb);
1574 struct net_bridge;
1575 struct net_bridge_fdb_entry *(*br_fdb_get_hook)(struct net_bridge *br,
1576 						unsigned char *addr);
1577 void (*br_fdb_put_hook)(struct net_bridge_fdb_entry *ent);
1578 
1579 static __inline__ int handle_bridge(struct sk_buff **pskb,
1580 				    struct packet_type **pt_prev, int *ret)
1581 {
1582 	struct net_bridge_port *port;
1583 
1584 	if ((*pskb)->pkt_type == PACKET_LOOPBACK ||
1585 	    (port = rcu_dereference((*pskb)->dev->br_port)) == NULL)
1586 		return 0;
1587 
1588 	if (*pt_prev) {
1589 		*ret = deliver_skb(*pskb, *pt_prev);
1590 		*pt_prev = NULL;
1591 	}
1592 
1593 	return br_handle_frame_hook(port, pskb);
1594 }
1595 #else
1596 #define handle_bridge(skb, pt_prev, ret)	(0)
1597 #endif
1598 
1599 #ifdef CONFIG_NET_CLS_ACT
1600 /* TODO: Maybe we should just force sch_ingress to be compiled in
1601  * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
1602  * a compare and 2 stores extra right now if we dont have it on
1603  * but have CONFIG_NET_CLS_ACT
1604  * NOTE: This doesnt stop any functionality; if you dont have
1605  * the ingress scheduler, you just cant add policies on ingress.
1606  *
1607  */
1608 static int ing_filter(struct sk_buff *skb)
1609 {
1610 	struct Qdisc *q;
1611 	struct net_device *dev = skb->dev;
1612 	int result = TC_ACT_OK;
1613 
1614 	if (dev->qdisc_ingress) {
1615 		__u32 ttl = (__u32) G_TC_RTTL(skb->tc_verd);
1616 		if (MAX_RED_LOOP < ttl++) {
1617 			printk("Redir loop detected Dropping packet (%s->%s)\n",
1618 				skb->input_dev?skb->input_dev->name:"??",skb->dev->name);
1619 			return TC_ACT_SHOT;
1620 		}
1621 
1622 		skb->tc_verd = SET_TC_RTTL(skb->tc_verd,ttl);
1623 
1624 		skb->tc_verd = SET_TC_AT(skb->tc_verd,AT_INGRESS);
1625 		if (NULL == skb->input_dev) {
1626 			skb->input_dev = skb->dev;
1627 			printk("ing_filter:  fixed  %s out %s\n",skb->input_dev->name,skb->dev->name);
1628 		}
1629 		spin_lock(&dev->ingress_lock);
1630 		if ((q = dev->qdisc_ingress) != NULL)
1631 			result = q->enqueue(skb, q);
1632 		spin_unlock(&dev->ingress_lock);
1633 
1634 	}
1635 
1636 	return result;
1637 }
1638 #endif
1639 
1640 int netif_receive_skb(struct sk_buff *skb)
1641 {
1642 	struct packet_type *ptype, *pt_prev;
1643 	int ret = NET_RX_DROP;
1644 	unsigned short type;
1645 
1646 	/* if we've gotten here through NAPI, check netpoll */
1647 	if (skb->dev->poll && netpoll_rx(skb))
1648 		return NET_RX_DROP;
1649 
1650 	if (!skb->stamp.tv_sec)
1651 		net_timestamp(&skb->stamp);
1652 
1653 	skb_bond(skb);
1654 
1655 	__get_cpu_var(netdev_rx_stat).total++;
1656 
1657 	skb->h.raw = skb->nh.raw = skb->data;
1658 	skb->mac_len = skb->nh.raw - skb->mac.raw;
1659 
1660 	pt_prev = NULL;
1661 
1662 	rcu_read_lock();
1663 
1664 #ifdef CONFIG_NET_CLS_ACT
1665 	if (skb->tc_verd & TC_NCLS) {
1666 		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
1667 		goto ncls;
1668 	}
1669 #endif
1670 
1671 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
1672 		if (!ptype->dev || ptype->dev == skb->dev) {
1673 			if (pt_prev)
1674 				ret = deliver_skb(skb, pt_prev);
1675 			pt_prev = ptype;
1676 		}
1677 	}
1678 
1679 #ifdef CONFIG_NET_CLS_ACT
1680 	if (pt_prev) {
1681 		ret = deliver_skb(skb, pt_prev);
1682 		pt_prev = NULL; /* noone else should process this after*/
1683 	} else {
1684 		skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
1685 	}
1686 
1687 	ret = ing_filter(skb);
1688 
1689 	if (ret == TC_ACT_SHOT || (ret == TC_ACT_STOLEN)) {
1690 		kfree_skb(skb);
1691 		goto out;
1692 	}
1693 
1694 	skb->tc_verd = 0;
1695 ncls:
1696 #endif
1697 
1698 	handle_diverter(skb);
1699 
1700 	if (handle_bridge(&skb, &pt_prev, &ret))
1701 		goto out;
1702 
1703 	type = skb->protocol;
1704 	list_for_each_entry_rcu(ptype, &ptype_base[ntohs(type)&15], list) {
1705 		if (ptype->type == type &&
1706 		    (!ptype->dev || ptype->dev == skb->dev)) {
1707 			if (pt_prev)
1708 				ret = deliver_skb(skb, pt_prev);
1709 			pt_prev = ptype;
1710 		}
1711 	}
1712 
1713 	if (pt_prev) {
1714 		ret = pt_prev->func(skb, skb->dev, pt_prev);
1715 	} else {
1716 		kfree_skb(skb);
1717 		/* Jamal, now you will not able to escape explaining
1718 		 * me how you were going to use this. :-)
1719 		 */
1720 		ret = NET_RX_DROP;
1721 	}
1722 
1723 out:
1724 	rcu_read_unlock();
1725 	return ret;
1726 }
1727 
1728 static int process_backlog(struct net_device *backlog_dev, int *budget)
1729 {
1730 	int work = 0;
1731 	int quota = min(backlog_dev->quota, *budget);
1732 	struct softnet_data *queue = &__get_cpu_var(softnet_data);
1733 	unsigned long start_time = jiffies;
1734 
1735 	for (;;) {
1736 		struct sk_buff *skb;
1737 		struct net_device *dev;
1738 
1739 		local_irq_disable();
1740 		skb = __skb_dequeue(&queue->input_pkt_queue);
1741 		if (!skb)
1742 			goto job_done;
1743 		local_irq_enable();
1744 
1745 		dev = skb->dev;
1746 
1747 		netif_receive_skb(skb);
1748 
1749 		dev_put(dev);
1750 
1751 		work++;
1752 
1753 		if (work >= quota || jiffies - start_time > 1)
1754 			break;
1755 
1756 	}
1757 
1758 	backlog_dev->quota -= work;
1759 	*budget -= work;
1760 	return -1;
1761 
1762 job_done:
1763 	backlog_dev->quota -= work;
1764 	*budget -= work;
1765 
1766 	list_del(&backlog_dev->poll_list);
1767 	smp_mb__before_clear_bit();
1768 	netif_poll_enable(backlog_dev);
1769 
1770 	if (queue->throttle)
1771 		queue->throttle = 0;
1772 	local_irq_enable();
1773 	return 0;
1774 }
1775 
1776 static void net_rx_action(struct softirq_action *h)
1777 {
1778 	struct softnet_data *queue = &__get_cpu_var(softnet_data);
1779 	unsigned long start_time = jiffies;
1780 	int budget = netdev_max_backlog;
1781 
1782 
1783 	local_irq_disable();
1784 
1785 	while (!list_empty(&queue->poll_list)) {
1786 		struct net_device *dev;
1787 
1788 		if (budget <= 0 || jiffies - start_time > 1)
1789 			goto softnet_break;
1790 
1791 		local_irq_enable();
1792 
1793 		dev = list_entry(queue->poll_list.next,
1794 				 struct net_device, poll_list);
1795 		netpoll_poll_lock(dev);
1796 
1797 		if (dev->quota <= 0 || dev->poll(dev, &budget)) {
1798 			netpoll_poll_unlock(dev);
1799 			local_irq_disable();
1800 			list_del(&dev->poll_list);
1801 			list_add_tail(&dev->poll_list, &queue->poll_list);
1802 			if (dev->quota < 0)
1803 				dev->quota += dev->weight;
1804 			else
1805 				dev->quota = dev->weight;
1806 		} else {
1807 			netpoll_poll_unlock(dev);
1808 			dev_put(dev);
1809 			local_irq_disable();
1810 		}
1811 	}
1812 out:
1813 	local_irq_enable();
1814 	return;
1815 
1816 softnet_break:
1817 	__get_cpu_var(netdev_rx_stat).time_squeeze++;
1818 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
1819 	goto out;
1820 }
1821 
1822 static gifconf_func_t * gifconf_list [NPROTO];
1823 
1824 /**
1825  *	register_gifconf	-	register a SIOCGIF handler
1826  *	@family: Address family
1827  *	@gifconf: Function handler
1828  *
1829  *	Register protocol dependent address dumping routines. The handler
1830  *	that is passed must not be freed or reused until it has been replaced
1831  *	by another handler.
1832  */
1833 int register_gifconf(unsigned int family, gifconf_func_t * gifconf)
1834 {
1835 	if (family >= NPROTO)
1836 		return -EINVAL;
1837 	gifconf_list[family] = gifconf;
1838 	return 0;
1839 }
1840 
1841 
1842 /*
1843  *	Map an interface index to its name (SIOCGIFNAME)
1844  */
1845 
1846 /*
1847  *	We need this ioctl for efficient implementation of the
1848  *	if_indextoname() function required by the IPv6 API.  Without
1849  *	it, we would have to search all the interfaces to find a
1850  *	match.  --pb
1851  */
1852 
1853 static int dev_ifname(struct ifreq __user *arg)
1854 {
1855 	struct net_device *dev;
1856 	struct ifreq ifr;
1857 
1858 	/*
1859 	 *	Fetch the caller's info block.
1860 	 */
1861 
1862 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
1863 		return -EFAULT;
1864 
1865 	read_lock(&dev_base_lock);
1866 	dev = __dev_get_by_index(ifr.ifr_ifindex);
1867 	if (!dev) {
1868 		read_unlock(&dev_base_lock);
1869 		return -ENODEV;
1870 	}
1871 
1872 	strcpy(ifr.ifr_name, dev->name);
1873 	read_unlock(&dev_base_lock);
1874 
1875 	if (copy_to_user(arg, &ifr, sizeof(struct ifreq)))
1876 		return -EFAULT;
1877 	return 0;
1878 }
1879 
1880 /*
1881  *	Perform a SIOCGIFCONF call. This structure will change
1882  *	size eventually, and there is nothing I can do about it.
1883  *	Thus we will need a 'compatibility mode'.
1884  */
1885 
1886 static int dev_ifconf(char __user *arg)
1887 {
1888 	struct ifconf ifc;
1889 	struct net_device *dev;
1890 	char __user *pos;
1891 	int len;
1892 	int total;
1893 	int i;
1894 
1895 	/*
1896 	 *	Fetch the caller's info block.
1897 	 */
1898 
1899 	if (copy_from_user(&ifc, arg, sizeof(struct ifconf)))
1900 		return -EFAULT;
1901 
1902 	pos = ifc.ifc_buf;
1903 	len = ifc.ifc_len;
1904 
1905 	/*
1906 	 *	Loop over the interfaces, and write an info block for each.
1907 	 */
1908 
1909 	total = 0;
1910 	for (dev = dev_base; dev; dev = dev->next) {
1911 		for (i = 0; i < NPROTO; i++) {
1912 			if (gifconf_list[i]) {
1913 				int done;
1914 				if (!pos)
1915 					done = gifconf_list[i](dev, NULL, 0);
1916 				else
1917 					done = gifconf_list[i](dev, pos + total,
1918 							       len - total);
1919 				if (done < 0)
1920 					return -EFAULT;
1921 				total += done;
1922 			}
1923 		}
1924   	}
1925 
1926 	/*
1927 	 *	All done.  Write the updated control block back to the caller.
1928 	 */
1929 	ifc.ifc_len = total;
1930 
1931 	/*
1932 	 * 	Both BSD and Solaris return 0 here, so we do too.
1933 	 */
1934 	return copy_to_user(arg, &ifc, sizeof(struct ifconf)) ? -EFAULT : 0;
1935 }
1936 
1937 #ifdef CONFIG_PROC_FS
1938 /*
1939  *	This is invoked by the /proc filesystem handler to display a device
1940  *	in detail.
1941  */
1942 static __inline__ struct net_device *dev_get_idx(loff_t pos)
1943 {
1944 	struct net_device *dev;
1945 	loff_t i;
1946 
1947 	for (i = 0, dev = dev_base; dev && i < pos; ++i, dev = dev->next);
1948 
1949 	return i == pos ? dev : NULL;
1950 }
1951 
1952 void *dev_seq_start(struct seq_file *seq, loff_t *pos)
1953 {
1954 	read_lock(&dev_base_lock);
1955 	return *pos ? dev_get_idx(*pos - 1) : SEQ_START_TOKEN;
1956 }
1957 
1958 void *dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1959 {
1960 	++*pos;
1961 	return v == SEQ_START_TOKEN ? dev_base : ((struct net_device *)v)->next;
1962 }
1963 
1964 void dev_seq_stop(struct seq_file *seq, void *v)
1965 {
1966 	read_unlock(&dev_base_lock);
1967 }
1968 
1969 static void dev_seq_printf_stats(struct seq_file *seq, struct net_device *dev)
1970 {
1971 	if (dev->get_stats) {
1972 		struct net_device_stats *stats = dev->get_stats(dev);
1973 
1974 		seq_printf(seq, "%6s:%8lu %7lu %4lu %4lu %4lu %5lu %10lu %9lu "
1975 				"%8lu %7lu %4lu %4lu %4lu %5lu %7lu %10lu\n",
1976 			   dev->name, stats->rx_bytes, stats->rx_packets,
1977 			   stats->rx_errors,
1978 			   stats->rx_dropped + stats->rx_missed_errors,
1979 			   stats->rx_fifo_errors,
1980 			   stats->rx_length_errors + stats->rx_over_errors +
1981 			     stats->rx_crc_errors + stats->rx_frame_errors,
1982 			   stats->rx_compressed, stats->multicast,
1983 			   stats->tx_bytes, stats->tx_packets,
1984 			   stats->tx_errors, stats->tx_dropped,
1985 			   stats->tx_fifo_errors, stats->collisions,
1986 			   stats->tx_carrier_errors +
1987 			     stats->tx_aborted_errors +
1988 			     stats->tx_window_errors +
1989 			     stats->tx_heartbeat_errors,
1990 			   stats->tx_compressed);
1991 	} else
1992 		seq_printf(seq, "%6s: No statistics available.\n", dev->name);
1993 }
1994 
1995 /*
1996  *	Called from the PROCfs module. This now uses the new arbitrary sized
1997  *	/proc/net interface to create /proc/net/dev
1998  */
1999 static int dev_seq_show(struct seq_file *seq, void *v)
2000 {
2001 	if (v == SEQ_START_TOKEN)
2002 		seq_puts(seq, "Inter-|   Receive                            "
2003 			      "                    |  Transmit\n"
2004 			      " face |bytes    packets errs drop fifo frame "
2005 			      "compressed multicast|bytes    packets errs "
2006 			      "drop fifo colls carrier compressed\n");
2007 	else
2008 		dev_seq_printf_stats(seq, v);
2009 	return 0;
2010 }
2011 
2012 static struct netif_rx_stats *softnet_get_online(loff_t *pos)
2013 {
2014 	struct netif_rx_stats *rc = NULL;
2015 
2016 	while (*pos < NR_CPUS)
2017 	       	if (cpu_online(*pos)) {
2018 			rc = &per_cpu(netdev_rx_stat, *pos);
2019 			break;
2020 		} else
2021 			++*pos;
2022 	return rc;
2023 }
2024 
2025 static void *softnet_seq_start(struct seq_file *seq, loff_t *pos)
2026 {
2027 	return softnet_get_online(pos);
2028 }
2029 
2030 static void *softnet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2031 {
2032 	++*pos;
2033 	return softnet_get_online(pos);
2034 }
2035 
2036 static void softnet_seq_stop(struct seq_file *seq, void *v)
2037 {
2038 }
2039 
2040 static int softnet_seq_show(struct seq_file *seq, void *v)
2041 {
2042 	struct netif_rx_stats *s = v;
2043 
2044 	seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x %08x\n",
2045 		   s->total, s->dropped, s->time_squeeze, s->throttled,
2046 		   s->fastroute_hit, s->fastroute_success, s->fastroute_defer,
2047 		   s->fastroute_deferred_out,
2048 #if 0
2049 		   s->fastroute_latency_reduction
2050 #else
2051 		   s->cpu_collision
2052 #endif
2053 		  );
2054 	return 0;
2055 }
2056 
2057 static struct seq_operations dev_seq_ops = {
2058 	.start = dev_seq_start,
2059 	.next  = dev_seq_next,
2060 	.stop  = dev_seq_stop,
2061 	.show  = dev_seq_show,
2062 };
2063 
2064 static int dev_seq_open(struct inode *inode, struct file *file)
2065 {
2066 	return seq_open(file, &dev_seq_ops);
2067 }
2068 
2069 static struct file_operations dev_seq_fops = {
2070 	.owner	 = THIS_MODULE,
2071 	.open    = dev_seq_open,
2072 	.read    = seq_read,
2073 	.llseek  = seq_lseek,
2074 	.release = seq_release,
2075 };
2076 
2077 static struct seq_operations softnet_seq_ops = {
2078 	.start = softnet_seq_start,
2079 	.next  = softnet_seq_next,
2080 	.stop  = softnet_seq_stop,
2081 	.show  = softnet_seq_show,
2082 };
2083 
2084 static int softnet_seq_open(struct inode *inode, struct file *file)
2085 {
2086 	return seq_open(file, &softnet_seq_ops);
2087 }
2088 
2089 static struct file_operations softnet_seq_fops = {
2090 	.owner	 = THIS_MODULE,
2091 	.open    = softnet_seq_open,
2092 	.read    = seq_read,
2093 	.llseek  = seq_lseek,
2094 	.release = seq_release,
2095 };
2096 
2097 #ifdef WIRELESS_EXT
2098 extern int wireless_proc_init(void);
2099 #else
2100 #define wireless_proc_init() 0
2101 #endif
2102 
2103 static int __init dev_proc_init(void)
2104 {
2105 	int rc = -ENOMEM;
2106 
2107 	if (!proc_net_fops_create("dev", S_IRUGO, &dev_seq_fops))
2108 		goto out;
2109 	if (!proc_net_fops_create("softnet_stat", S_IRUGO, &softnet_seq_fops))
2110 		goto out_dev;
2111 	if (wireless_proc_init())
2112 		goto out_softnet;
2113 	rc = 0;
2114 out:
2115 	return rc;
2116 out_softnet:
2117 	proc_net_remove("softnet_stat");
2118 out_dev:
2119 	proc_net_remove("dev");
2120 	goto out;
2121 }
2122 #else
2123 #define dev_proc_init() 0
2124 #endif	/* CONFIG_PROC_FS */
2125 
2126 
2127 /**
2128  *	netdev_set_master	-	set up master/slave pair
2129  *	@slave: slave device
2130  *	@master: new master device
2131  *
2132  *	Changes the master device of the slave. Pass %NULL to break the
2133  *	bonding. The caller must hold the RTNL semaphore. On a failure
2134  *	a negative errno code is returned. On success the reference counts
2135  *	are adjusted, %RTM_NEWLINK is sent to the routing socket and the
2136  *	function returns zero.
2137  */
2138 int netdev_set_master(struct net_device *slave, struct net_device *master)
2139 {
2140 	struct net_device *old = slave->master;
2141 
2142 	ASSERT_RTNL();
2143 
2144 	if (master) {
2145 		if (old)
2146 			return -EBUSY;
2147 		dev_hold(master);
2148 	}
2149 
2150 	slave->master = master;
2151 
2152 	synchronize_net();
2153 
2154 	if (old)
2155 		dev_put(old);
2156 
2157 	if (master)
2158 		slave->flags |= IFF_SLAVE;
2159 	else
2160 		slave->flags &= ~IFF_SLAVE;
2161 
2162 	rtmsg_ifinfo(RTM_NEWLINK, slave, IFF_SLAVE);
2163 	return 0;
2164 }
2165 
2166 /**
2167  *	dev_set_promiscuity	- update promiscuity count on a device
2168  *	@dev: device
2169  *	@inc: modifier
2170  *
2171  *	Add or remove promsicuity from a device. While the count in the device
2172  *	remains above zero the interface remains promiscuous. Once it hits zero
2173  *	the device reverts back to normal filtering operation. A negative inc
2174  *	value is used to drop promiscuity on the device.
2175  */
2176 void dev_set_promiscuity(struct net_device *dev, int inc)
2177 {
2178 	unsigned short old_flags = dev->flags;
2179 
2180 	dev->flags |= IFF_PROMISC;
2181 	if ((dev->promiscuity += inc) == 0)
2182 		dev->flags &= ~IFF_PROMISC;
2183 	if (dev->flags ^ old_flags) {
2184 		dev_mc_upload(dev);
2185 		printk(KERN_INFO "device %s %s promiscuous mode\n",
2186 		       dev->name, (dev->flags & IFF_PROMISC) ? "entered" :
2187 		       					       "left");
2188 	}
2189 }
2190 
2191 /**
2192  *	dev_set_allmulti	- update allmulti count on a device
2193  *	@dev: device
2194  *	@inc: modifier
2195  *
2196  *	Add or remove reception of all multicast frames to a device. While the
2197  *	count in the device remains above zero the interface remains listening
2198  *	to all interfaces. Once it hits zero the device reverts back to normal
2199  *	filtering operation. A negative @inc value is used to drop the counter
2200  *	when releasing a resource needing all multicasts.
2201  */
2202 
2203 void dev_set_allmulti(struct net_device *dev, int inc)
2204 {
2205 	unsigned short old_flags = dev->flags;
2206 
2207 	dev->flags |= IFF_ALLMULTI;
2208 	if ((dev->allmulti += inc) == 0)
2209 		dev->flags &= ~IFF_ALLMULTI;
2210 	if (dev->flags ^ old_flags)
2211 		dev_mc_upload(dev);
2212 }
2213 
2214 unsigned dev_get_flags(const struct net_device *dev)
2215 {
2216 	unsigned flags;
2217 
2218 	flags = (dev->flags & ~(IFF_PROMISC |
2219 				IFF_ALLMULTI |
2220 				IFF_RUNNING)) |
2221 		(dev->gflags & (IFF_PROMISC |
2222 				IFF_ALLMULTI));
2223 
2224 	if (netif_running(dev) && netif_carrier_ok(dev))
2225 		flags |= IFF_RUNNING;
2226 
2227 	return flags;
2228 }
2229 
2230 int dev_change_flags(struct net_device *dev, unsigned flags)
2231 {
2232 	int ret;
2233 	int old_flags = dev->flags;
2234 
2235 	/*
2236 	 *	Set the flags on our device.
2237 	 */
2238 
2239 	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
2240 			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
2241 			       IFF_AUTOMEDIA)) |
2242 		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
2243 				    IFF_ALLMULTI));
2244 
2245 	/*
2246 	 *	Load in the correct multicast list now the flags have changed.
2247 	 */
2248 
2249 	dev_mc_upload(dev);
2250 
2251 	/*
2252 	 *	Have we downed the interface. We handle IFF_UP ourselves
2253 	 *	according to user attempts to set it, rather than blindly
2254 	 *	setting it.
2255 	 */
2256 
2257 	ret = 0;
2258 	if ((old_flags ^ flags) & IFF_UP) {	/* Bit is different  ? */
2259 		ret = ((old_flags & IFF_UP) ? dev_close : dev_open)(dev);
2260 
2261 		if (!ret)
2262 			dev_mc_upload(dev);
2263 	}
2264 
2265 	if (dev->flags & IFF_UP &&
2266 	    ((old_flags ^ dev->flags) &~ (IFF_UP | IFF_PROMISC | IFF_ALLMULTI |
2267 					  IFF_VOLATILE)))
2268 		notifier_call_chain(&netdev_chain, NETDEV_CHANGE, dev);
2269 
2270 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
2271 		int inc = (flags & IFF_PROMISC) ? +1 : -1;
2272 		dev->gflags ^= IFF_PROMISC;
2273 		dev_set_promiscuity(dev, inc);
2274 	}
2275 
2276 	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
2277 	   is important. Some (broken) drivers set IFF_PROMISC, when
2278 	   IFF_ALLMULTI is requested not asking us and not reporting.
2279 	 */
2280 	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
2281 		int inc = (flags & IFF_ALLMULTI) ? +1 : -1;
2282 		dev->gflags ^= IFF_ALLMULTI;
2283 		dev_set_allmulti(dev, inc);
2284 	}
2285 
2286 	if (old_flags ^ dev->flags)
2287 		rtmsg_ifinfo(RTM_NEWLINK, dev, old_flags ^ dev->flags);
2288 
2289 	return ret;
2290 }
2291 
2292 int dev_set_mtu(struct net_device *dev, int new_mtu)
2293 {
2294 	int err;
2295 
2296 	if (new_mtu == dev->mtu)
2297 		return 0;
2298 
2299 	/*	MTU must be positive.	 */
2300 	if (new_mtu < 0)
2301 		return -EINVAL;
2302 
2303 	if (!netif_device_present(dev))
2304 		return -ENODEV;
2305 
2306 	err = 0;
2307 	if (dev->change_mtu)
2308 		err = dev->change_mtu(dev, new_mtu);
2309 	else
2310 		dev->mtu = new_mtu;
2311 	if (!err && dev->flags & IFF_UP)
2312 		notifier_call_chain(&netdev_chain,
2313 				    NETDEV_CHANGEMTU, dev);
2314 	return err;
2315 }
2316 
2317 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
2318 {
2319 	int err;
2320 
2321 	if (!dev->set_mac_address)
2322 		return -EOPNOTSUPP;
2323 	if (sa->sa_family != dev->type)
2324 		return -EINVAL;
2325 	if (!netif_device_present(dev))
2326 		return -ENODEV;
2327 	err = dev->set_mac_address(dev, sa);
2328 	if (!err)
2329 		notifier_call_chain(&netdev_chain, NETDEV_CHANGEADDR, dev);
2330 	return err;
2331 }
2332 
2333 /*
2334  *	Perform the SIOCxIFxxx calls.
2335  */
2336 static int dev_ifsioc(struct ifreq *ifr, unsigned int cmd)
2337 {
2338 	int err;
2339 	struct net_device *dev = __dev_get_by_name(ifr->ifr_name);
2340 
2341 	if (!dev)
2342 		return -ENODEV;
2343 
2344 	switch (cmd) {
2345 		case SIOCGIFFLAGS:	/* Get interface flags */
2346 			ifr->ifr_flags = dev_get_flags(dev);
2347 			return 0;
2348 
2349 		case SIOCSIFFLAGS:	/* Set interface flags */
2350 			return dev_change_flags(dev, ifr->ifr_flags);
2351 
2352 		case SIOCGIFMETRIC:	/* Get the metric on the interface
2353 					   (currently unused) */
2354 			ifr->ifr_metric = 0;
2355 			return 0;
2356 
2357 		case SIOCSIFMETRIC:	/* Set the metric on the interface
2358 					   (currently unused) */
2359 			return -EOPNOTSUPP;
2360 
2361 		case SIOCGIFMTU:	/* Get the MTU of a device */
2362 			ifr->ifr_mtu = dev->mtu;
2363 			return 0;
2364 
2365 		case SIOCSIFMTU:	/* Set the MTU of a device */
2366 			return dev_set_mtu(dev, ifr->ifr_mtu);
2367 
2368 		case SIOCGIFHWADDR:
2369 			if (!dev->addr_len)
2370 				memset(ifr->ifr_hwaddr.sa_data, 0, sizeof ifr->ifr_hwaddr.sa_data);
2371 			else
2372 				memcpy(ifr->ifr_hwaddr.sa_data, dev->dev_addr,
2373 				       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
2374 			ifr->ifr_hwaddr.sa_family = dev->type;
2375 			return 0;
2376 
2377 		case SIOCSIFHWADDR:
2378 			return dev_set_mac_address(dev, &ifr->ifr_hwaddr);
2379 
2380 		case SIOCSIFHWBROADCAST:
2381 			if (ifr->ifr_hwaddr.sa_family != dev->type)
2382 				return -EINVAL;
2383 			memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
2384 			       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
2385 			notifier_call_chain(&netdev_chain,
2386 					    NETDEV_CHANGEADDR, dev);
2387 			return 0;
2388 
2389 		case SIOCGIFMAP:
2390 			ifr->ifr_map.mem_start = dev->mem_start;
2391 			ifr->ifr_map.mem_end   = dev->mem_end;
2392 			ifr->ifr_map.base_addr = dev->base_addr;
2393 			ifr->ifr_map.irq       = dev->irq;
2394 			ifr->ifr_map.dma       = dev->dma;
2395 			ifr->ifr_map.port      = dev->if_port;
2396 			return 0;
2397 
2398 		case SIOCSIFMAP:
2399 			if (dev->set_config) {
2400 				if (!netif_device_present(dev))
2401 					return -ENODEV;
2402 				return dev->set_config(dev, &ifr->ifr_map);
2403 			}
2404 			return -EOPNOTSUPP;
2405 
2406 		case SIOCADDMULTI:
2407 			if (!dev->set_multicast_list ||
2408 			    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
2409 				return -EINVAL;
2410 			if (!netif_device_present(dev))
2411 				return -ENODEV;
2412 			return dev_mc_add(dev, ifr->ifr_hwaddr.sa_data,
2413 					  dev->addr_len, 1);
2414 
2415 		case SIOCDELMULTI:
2416 			if (!dev->set_multicast_list ||
2417 			    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
2418 				return -EINVAL;
2419 			if (!netif_device_present(dev))
2420 				return -ENODEV;
2421 			return dev_mc_delete(dev, ifr->ifr_hwaddr.sa_data,
2422 					     dev->addr_len, 1);
2423 
2424 		case SIOCGIFINDEX:
2425 			ifr->ifr_ifindex = dev->ifindex;
2426 			return 0;
2427 
2428 		case SIOCGIFTXQLEN:
2429 			ifr->ifr_qlen = dev->tx_queue_len;
2430 			return 0;
2431 
2432 		case SIOCSIFTXQLEN:
2433 			if (ifr->ifr_qlen < 0)
2434 				return -EINVAL;
2435 			dev->tx_queue_len = ifr->ifr_qlen;
2436 			return 0;
2437 
2438 		case SIOCSIFNAME:
2439 			ifr->ifr_newname[IFNAMSIZ-1] = '\0';
2440 			return dev_change_name(dev, ifr->ifr_newname);
2441 
2442 		/*
2443 		 *	Unknown or private ioctl
2444 		 */
2445 
2446 		default:
2447 			if ((cmd >= SIOCDEVPRIVATE &&
2448 			    cmd <= SIOCDEVPRIVATE + 15) ||
2449 			    cmd == SIOCBONDENSLAVE ||
2450 			    cmd == SIOCBONDRELEASE ||
2451 			    cmd == SIOCBONDSETHWADDR ||
2452 			    cmd == SIOCBONDSLAVEINFOQUERY ||
2453 			    cmd == SIOCBONDINFOQUERY ||
2454 			    cmd == SIOCBONDCHANGEACTIVE ||
2455 			    cmd == SIOCGMIIPHY ||
2456 			    cmd == SIOCGMIIREG ||
2457 			    cmd == SIOCSMIIREG ||
2458 			    cmd == SIOCBRADDIF ||
2459 			    cmd == SIOCBRDELIF ||
2460 			    cmd == SIOCWANDEV) {
2461 				err = -EOPNOTSUPP;
2462 				if (dev->do_ioctl) {
2463 					if (netif_device_present(dev))
2464 						err = dev->do_ioctl(dev, ifr,
2465 								    cmd);
2466 					else
2467 						err = -ENODEV;
2468 				}
2469 			} else
2470 				err = -EINVAL;
2471 
2472 	}
2473 	return err;
2474 }
2475 
2476 /*
2477  *	This function handles all "interface"-type I/O control requests. The actual
2478  *	'doing' part of this is dev_ifsioc above.
2479  */
2480 
2481 /**
2482  *	dev_ioctl	-	network device ioctl
2483  *	@cmd: command to issue
2484  *	@arg: pointer to a struct ifreq in user space
2485  *
2486  *	Issue ioctl functions to devices. This is normally called by the
2487  *	user space syscall interfaces but can sometimes be useful for
2488  *	other purposes. The return value is the return from the syscall if
2489  *	positive or a negative errno code on error.
2490  */
2491 
2492 int dev_ioctl(unsigned int cmd, void __user *arg)
2493 {
2494 	struct ifreq ifr;
2495 	int ret;
2496 	char *colon;
2497 
2498 	/* One special case: SIOCGIFCONF takes ifconf argument
2499 	   and requires shared lock, because it sleeps writing
2500 	   to user space.
2501 	 */
2502 
2503 	if (cmd == SIOCGIFCONF) {
2504 		rtnl_shlock();
2505 		ret = dev_ifconf((char __user *) arg);
2506 		rtnl_shunlock();
2507 		return ret;
2508 	}
2509 	if (cmd == SIOCGIFNAME)
2510 		return dev_ifname((struct ifreq __user *)arg);
2511 
2512 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
2513 		return -EFAULT;
2514 
2515 	ifr.ifr_name[IFNAMSIZ-1] = 0;
2516 
2517 	colon = strchr(ifr.ifr_name, ':');
2518 	if (colon)
2519 		*colon = 0;
2520 
2521 	/*
2522 	 *	See which interface the caller is talking about.
2523 	 */
2524 
2525 	switch (cmd) {
2526 		/*
2527 		 *	These ioctl calls:
2528 		 *	- can be done by all.
2529 		 *	- atomic and do not require locking.
2530 		 *	- return a value
2531 		 */
2532 		case SIOCGIFFLAGS:
2533 		case SIOCGIFMETRIC:
2534 		case SIOCGIFMTU:
2535 		case SIOCGIFHWADDR:
2536 		case SIOCGIFSLAVE:
2537 		case SIOCGIFMAP:
2538 		case SIOCGIFINDEX:
2539 		case SIOCGIFTXQLEN:
2540 			dev_load(ifr.ifr_name);
2541 			read_lock(&dev_base_lock);
2542 			ret = dev_ifsioc(&ifr, cmd);
2543 			read_unlock(&dev_base_lock);
2544 			if (!ret) {
2545 				if (colon)
2546 					*colon = ':';
2547 				if (copy_to_user(arg, &ifr,
2548 						 sizeof(struct ifreq)))
2549 					ret = -EFAULT;
2550 			}
2551 			return ret;
2552 
2553 		case SIOCETHTOOL:
2554 			dev_load(ifr.ifr_name);
2555 			rtnl_lock();
2556 			ret = dev_ethtool(&ifr);
2557 			rtnl_unlock();
2558 			if (!ret) {
2559 				if (colon)
2560 					*colon = ':';
2561 				if (copy_to_user(arg, &ifr,
2562 						 sizeof(struct ifreq)))
2563 					ret = -EFAULT;
2564 			}
2565 			return ret;
2566 
2567 		/*
2568 		 *	These ioctl calls:
2569 		 *	- require superuser power.
2570 		 *	- require strict serialization.
2571 		 *	- return a value
2572 		 */
2573 		case SIOCGMIIPHY:
2574 		case SIOCGMIIREG:
2575 		case SIOCSIFNAME:
2576 			if (!capable(CAP_NET_ADMIN))
2577 				return -EPERM;
2578 			dev_load(ifr.ifr_name);
2579 			rtnl_lock();
2580 			ret = dev_ifsioc(&ifr, cmd);
2581 			rtnl_unlock();
2582 			if (!ret) {
2583 				if (colon)
2584 					*colon = ':';
2585 				if (copy_to_user(arg, &ifr,
2586 						 sizeof(struct ifreq)))
2587 					ret = -EFAULT;
2588 			}
2589 			return ret;
2590 
2591 		/*
2592 		 *	These ioctl calls:
2593 		 *	- require superuser power.
2594 		 *	- require strict serialization.
2595 		 *	- do not return a value
2596 		 */
2597 		case SIOCSIFFLAGS:
2598 		case SIOCSIFMETRIC:
2599 		case SIOCSIFMTU:
2600 		case SIOCSIFMAP:
2601 		case SIOCSIFHWADDR:
2602 		case SIOCSIFSLAVE:
2603 		case SIOCADDMULTI:
2604 		case SIOCDELMULTI:
2605 		case SIOCSIFHWBROADCAST:
2606 		case SIOCSIFTXQLEN:
2607 		case SIOCSMIIREG:
2608 		case SIOCBONDENSLAVE:
2609 		case SIOCBONDRELEASE:
2610 		case SIOCBONDSETHWADDR:
2611 		case SIOCBONDSLAVEINFOQUERY:
2612 		case SIOCBONDINFOQUERY:
2613 		case SIOCBONDCHANGEACTIVE:
2614 		case SIOCBRADDIF:
2615 		case SIOCBRDELIF:
2616 			if (!capable(CAP_NET_ADMIN))
2617 				return -EPERM;
2618 			dev_load(ifr.ifr_name);
2619 			rtnl_lock();
2620 			ret = dev_ifsioc(&ifr, cmd);
2621 			rtnl_unlock();
2622 			return ret;
2623 
2624 		case SIOCGIFMEM:
2625 			/* Get the per device memory space. We can add this but
2626 			 * currently do not support it */
2627 		case SIOCSIFMEM:
2628 			/* Set the per device memory buffer space.
2629 			 * Not applicable in our case */
2630 		case SIOCSIFLINK:
2631 			return -EINVAL;
2632 
2633 		/*
2634 		 *	Unknown or private ioctl.
2635 		 */
2636 		default:
2637 			if (cmd == SIOCWANDEV ||
2638 			    (cmd >= SIOCDEVPRIVATE &&
2639 			     cmd <= SIOCDEVPRIVATE + 15)) {
2640 				dev_load(ifr.ifr_name);
2641 				rtnl_lock();
2642 				ret = dev_ifsioc(&ifr, cmd);
2643 				rtnl_unlock();
2644 				if (!ret && copy_to_user(arg, &ifr,
2645 							 sizeof(struct ifreq)))
2646 					ret = -EFAULT;
2647 				return ret;
2648 			}
2649 #ifdef WIRELESS_EXT
2650 			/* Take care of Wireless Extensions */
2651 			if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) {
2652 				/* If command is `set a parameter', or
2653 				 * `get the encoding parameters', check if
2654 				 * the user has the right to do it */
2655 				if (IW_IS_SET(cmd) || cmd == SIOCGIWENCODE) {
2656 					if (!capable(CAP_NET_ADMIN))
2657 						return -EPERM;
2658 				}
2659 				dev_load(ifr.ifr_name);
2660 				rtnl_lock();
2661 				/* Follow me in net/core/wireless.c */
2662 				ret = wireless_process_ioctl(&ifr, cmd);
2663 				rtnl_unlock();
2664 				if (IW_IS_GET(cmd) &&
2665 				    copy_to_user(arg, &ifr,
2666 					    	 sizeof(struct ifreq)))
2667 					ret = -EFAULT;
2668 				return ret;
2669 			}
2670 #endif	/* WIRELESS_EXT */
2671 			return -EINVAL;
2672 	}
2673 }
2674 
2675 
2676 /**
2677  *	dev_new_index	-	allocate an ifindex
2678  *
2679  *	Returns a suitable unique value for a new device interface
2680  *	number.  The caller must hold the rtnl semaphore or the
2681  *	dev_base_lock to be sure it remains unique.
2682  */
2683 static int dev_new_index(void)
2684 {
2685 	static int ifindex;
2686 	for (;;) {
2687 		if (++ifindex <= 0)
2688 			ifindex = 1;
2689 		if (!__dev_get_by_index(ifindex))
2690 			return ifindex;
2691 	}
2692 }
2693 
2694 static int dev_boot_phase = 1;
2695 
2696 /* Delayed registration/unregisteration */
2697 static DEFINE_SPINLOCK(net_todo_list_lock);
2698 static struct list_head net_todo_list = LIST_HEAD_INIT(net_todo_list);
2699 
2700 static inline void net_set_todo(struct net_device *dev)
2701 {
2702 	spin_lock(&net_todo_list_lock);
2703 	list_add_tail(&dev->todo_list, &net_todo_list);
2704 	spin_unlock(&net_todo_list_lock);
2705 }
2706 
2707 /**
2708  *	register_netdevice	- register a network device
2709  *	@dev: device to register
2710  *
2711  *	Take a completed network device structure and add it to the kernel
2712  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
2713  *	chain. 0 is returned on success. A negative errno code is returned
2714  *	on a failure to set up the device, or if the name is a duplicate.
2715  *
2716  *	Callers must hold the rtnl semaphore. You may want
2717  *	register_netdev() instead of this.
2718  *
2719  *	BUGS:
2720  *	The locking appears insufficient to guarantee two parallel registers
2721  *	will not get the same name.
2722  */
2723 
2724 int register_netdevice(struct net_device *dev)
2725 {
2726 	struct hlist_head *head;
2727 	struct hlist_node *p;
2728 	int ret;
2729 
2730 	BUG_ON(dev_boot_phase);
2731 	ASSERT_RTNL();
2732 
2733 	/* When net_device's are persistent, this will be fatal. */
2734 	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
2735 
2736 	spin_lock_init(&dev->queue_lock);
2737 	spin_lock_init(&dev->xmit_lock);
2738 	dev->xmit_lock_owner = -1;
2739 #ifdef CONFIG_NET_CLS_ACT
2740 	spin_lock_init(&dev->ingress_lock);
2741 #endif
2742 
2743 	ret = alloc_divert_blk(dev);
2744 	if (ret)
2745 		goto out;
2746 
2747 	dev->iflink = -1;
2748 
2749 	/* Init, if this function is available */
2750 	if (dev->init) {
2751 		ret = dev->init(dev);
2752 		if (ret) {
2753 			if (ret > 0)
2754 				ret = -EIO;
2755 			goto out_err;
2756 		}
2757 	}
2758 
2759 	if (!dev_valid_name(dev->name)) {
2760 		ret = -EINVAL;
2761 		goto out_err;
2762 	}
2763 
2764 	dev->ifindex = dev_new_index();
2765 	if (dev->iflink == -1)
2766 		dev->iflink = dev->ifindex;
2767 
2768 	/* Check for existence of name */
2769 	head = dev_name_hash(dev->name);
2770 	hlist_for_each(p, head) {
2771 		struct net_device *d
2772 			= hlist_entry(p, struct net_device, name_hlist);
2773 		if (!strncmp(d->name, dev->name, IFNAMSIZ)) {
2774 			ret = -EEXIST;
2775  			goto out_err;
2776 		}
2777  	}
2778 
2779 	/* Fix illegal SG+CSUM combinations. */
2780 	if ((dev->features & NETIF_F_SG) &&
2781 	    !(dev->features & (NETIF_F_IP_CSUM |
2782 			       NETIF_F_NO_CSUM |
2783 			       NETIF_F_HW_CSUM))) {
2784 		printk("%s: Dropping NETIF_F_SG since no checksum feature.\n",
2785 		       dev->name);
2786 		dev->features &= ~NETIF_F_SG;
2787 	}
2788 
2789 	/* TSO requires that SG is present as well. */
2790 	if ((dev->features & NETIF_F_TSO) &&
2791 	    !(dev->features & NETIF_F_SG)) {
2792 		printk("%s: Dropping NETIF_F_TSO since no SG feature.\n",
2793 		       dev->name);
2794 		dev->features &= ~NETIF_F_TSO;
2795 	}
2796 
2797 	/*
2798 	 *	nil rebuild_header routine,
2799 	 *	that should be never called and used as just bug trap.
2800 	 */
2801 
2802 	if (!dev->rebuild_header)
2803 		dev->rebuild_header = default_rebuild_header;
2804 
2805 	/*
2806 	 *	Default initial state at registry is that the
2807 	 *	device is present.
2808 	 */
2809 
2810 	set_bit(__LINK_STATE_PRESENT, &dev->state);
2811 
2812 	dev->next = NULL;
2813 	dev_init_scheduler(dev);
2814 	write_lock_bh(&dev_base_lock);
2815 	*dev_tail = dev;
2816 	dev_tail = &dev->next;
2817 	hlist_add_head(&dev->name_hlist, head);
2818 	hlist_add_head(&dev->index_hlist, dev_index_hash(dev->ifindex));
2819 	dev_hold(dev);
2820 	dev->reg_state = NETREG_REGISTERING;
2821 	write_unlock_bh(&dev_base_lock);
2822 
2823 	/* Notify protocols, that a new device appeared. */
2824 	notifier_call_chain(&netdev_chain, NETDEV_REGISTER, dev);
2825 
2826 	/* Finish registration after unlock */
2827 	net_set_todo(dev);
2828 	ret = 0;
2829 
2830 out:
2831 	return ret;
2832 out_err:
2833 	free_divert_blk(dev);
2834 	goto out;
2835 }
2836 
2837 /**
2838  *	register_netdev	- register a network device
2839  *	@dev: device to register
2840  *
2841  *	Take a completed network device structure and add it to the kernel
2842  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
2843  *	chain. 0 is returned on success. A negative errno code is returned
2844  *	on a failure to set up the device, or if the name is a duplicate.
2845  *
2846  *	This is a wrapper around register_netdev that takes the rtnl semaphore
2847  *	and expands the device name if you passed a format string to
2848  *	alloc_netdev.
2849  */
2850 int register_netdev(struct net_device *dev)
2851 {
2852 	int err;
2853 
2854 	rtnl_lock();
2855 
2856 	/*
2857 	 * If the name is a format string the caller wants us to do a
2858 	 * name allocation.
2859 	 */
2860 	if (strchr(dev->name, '%')) {
2861 		err = dev_alloc_name(dev, dev->name);
2862 		if (err < 0)
2863 			goto out;
2864 	}
2865 
2866 	/*
2867 	 * Back compatibility hook. Kill this one in 2.5
2868 	 */
2869 	if (dev->name[0] == 0 || dev->name[0] == ' ') {
2870 		err = dev_alloc_name(dev, "eth%d");
2871 		if (err < 0)
2872 			goto out;
2873 	}
2874 
2875 	err = register_netdevice(dev);
2876 out:
2877 	rtnl_unlock();
2878 	return err;
2879 }
2880 EXPORT_SYMBOL(register_netdev);
2881 
2882 /*
2883  * netdev_wait_allrefs - wait until all references are gone.
2884  *
2885  * This is called when unregistering network devices.
2886  *
2887  * Any protocol or device that holds a reference should register
2888  * for netdevice notification, and cleanup and put back the
2889  * reference if they receive an UNREGISTER event.
2890  * We can get stuck here if buggy protocols don't correctly
2891  * call dev_put.
2892  */
2893 static void netdev_wait_allrefs(struct net_device *dev)
2894 {
2895 	unsigned long rebroadcast_time, warning_time;
2896 
2897 	rebroadcast_time = warning_time = jiffies;
2898 	while (atomic_read(&dev->refcnt) != 0) {
2899 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
2900 			rtnl_shlock();
2901 
2902 			/* Rebroadcast unregister notification */
2903 			notifier_call_chain(&netdev_chain,
2904 					    NETDEV_UNREGISTER, dev);
2905 
2906 			if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
2907 				     &dev->state)) {
2908 				/* We must not have linkwatch events
2909 				 * pending on unregister. If this
2910 				 * happens, we simply run the queue
2911 				 * unscheduled, resulting in a noop
2912 				 * for this device.
2913 				 */
2914 				linkwatch_run_queue();
2915 			}
2916 
2917 			rtnl_shunlock();
2918 
2919 			rebroadcast_time = jiffies;
2920 		}
2921 
2922 		msleep(250);
2923 
2924 		if (time_after(jiffies, warning_time + 10 * HZ)) {
2925 			printk(KERN_EMERG "unregister_netdevice: "
2926 			       "waiting for %s to become free. Usage "
2927 			       "count = %d\n",
2928 			       dev->name, atomic_read(&dev->refcnt));
2929 			warning_time = jiffies;
2930 		}
2931 	}
2932 }
2933 
2934 /* The sequence is:
2935  *
2936  *	rtnl_lock();
2937  *	...
2938  *	register_netdevice(x1);
2939  *	register_netdevice(x2);
2940  *	...
2941  *	unregister_netdevice(y1);
2942  *	unregister_netdevice(y2);
2943  *      ...
2944  *	rtnl_unlock();
2945  *	free_netdev(y1);
2946  *	free_netdev(y2);
2947  *
2948  * We are invoked by rtnl_unlock() after it drops the semaphore.
2949  * This allows us to deal with problems:
2950  * 1) We can create/delete sysfs objects which invoke hotplug
2951  *    without deadlocking with linkwatch via keventd.
2952  * 2) Since we run with the RTNL semaphore not held, we can sleep
2953  *    safely in order to wait for the netdev refcnt to drop to zero.
2954  */
2955 static DECLARE_MUTEX(net_todo_run_mutex);
2956 void netdev_run_todo(void)
2957 {
2958 	struct list_head list = LIST_HEAD_INIT(list);
2959 	int err;
2960 
2961 
2962 	/* Need to guard against multiple cpu's getting out of order. */
2963 	down(&net_todo_run_mutex);
2964 
2965 	/* Not safe to do outside the semaphore.  We must not return
2966 	 * until all unregister events invoked by the local processor
2967 	 * have been completed (either by this todo run, or one on
2968 	 * another cpu).
2969 	 */
2970 	if (list_empty(&net_todo_list))
2971 		goto out;
2972 
2973 	/* Snapshot list, allow later requests */
2974 	spin_lock(&net_todo_list_lock);
2975 	list_splice_init(&net_todo_list, &list);
2976 	spin_unlock(&net_todo_list_lock);
2977 
2978 	while (!list_empty(&list)) {
2979 		struct net_device *dev
2980 			= list_entry(list.next, struct net_device, todo_list);
2981 		list_del(&dev->todo_list);
2982 
2983 		switch(dev->reg_state) {
2984 		case NETREG_REGISTERING:
2985 			err = netdev_register_sysfs(dev);
2986 			if (err)
2987 				printk(KERN_ERR "%s: failed sysfs registration (%d)\n",
2988 				       dev->name, err);
2989 			dev->reg_state = NETREG_REGISTERED;
2990 			break;
2991 
2992 		case NETREG_UNREGISTERING:
2993 			netdev_unregister_sysfs(dev);
2994 			dev->reg_state = NETREG_UNREGISTERED;
2995 
2996 			netdev_wait_allrefs(dev);
2997 
2998 			/* paranoia */
2999 			BUG_ON(atomic_read(&dev->refcnt));
3000 			BUG_TRAP(!dev->ip_ptr);
3001 			BUG_TRAP(!dev->ip6_ptr);
3002 			BUG_TRAP(!dev->dn_ptr);
3003 
3004 
3005 			/* It must be the very last action,
3006 			 * after this 'dev' may point to freed up memory.
3007 			 */
3008 			if (dev->destructor)
3009 				dev->destructor(dev);
3010 			break;
3011 
3012 		default:
3013 			printk(KERN_ERR "network todo '%s' but state %d\n",
3014 			       dev->name, dev->reg_state);
3015 			break;
3016 		}
3017 	}
3018 
3019 out:
3020 	up(&net_todo_run_mutex);
3021 }
3022 
3023 /**
3024  *	alloc_netdev - allocate network device
3025  *	@sizeof_priv:	size of private data to allocate space for
3026  *	@name:		device name format string
3027  *	@setup:		callback to initialize device
3028  *
3029  *	Allocates a struct net_device with private data area for driver use
3030  *	and performs basic initialization.
3031  */
3032 struct net_device *alloc_netdev(int sizeof_priv, const char *name,
3033 		void (*setup)(struct net_device *))
3034 {
3035 	void *p;
3036 	struct net_device *dev;
3037 	int alloc_size;
3038 
3039 	/* ensure 32-byte alignment of both the device and private area */
3040 	alloc_size = (sizeof(*dev) + NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST;
3041 	alloc_size += sizeof_priv + NETDEV_ALIGN_CONST;
3042 
3043 	p = kmalloc(alloc_size, GFP_KERNEL);
3044 	if (!p) {
3045 		printk(KERN_ERR "alloc_dev: Unable to allocate device.\n");
3046 		return NULL;
3047 	}
3048 	memset(p, 0, alloc_size);
3049 
3050 	dev = (struct net_device *)
3051 		(((long)p + NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST);
3052 	dev->padded = (char *)dev - (char *)p;
3053 
3054 	if (sizeof_priv)
3055 		dev->priv = netdev_priv(dev);
3056 
3057 	setup(dev);
3058 	strcpy(dev->name, name);
3059 	return dev;
3060 }
3061 EXPORT_SYMBOL(alloc_netdev);
3062 
3063 /**
3064  *	free_netdev - free network device
3065  *	@dev: device
3066  *
3067  *	This function does the last stage of destroying an allocated device
3068  * 	interface. The reference to the device object is released.
3069  *	If this is the last reference then it will be freed.
3070  */
3071 void free_netdev(struct net_device *dev)
3072 {
3073 #ifdef CONFIG_SYSFS
3074 	/*  Compatiablity with error handling in drivers */
3075 	if (dev->reg_state == NETREG_UNINITIALIZED) {
3076 		kfree((char *)dev - dev->padded);
3077 		return;
3078 	}
3079 
3080 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
3081 	dev->reg_state = NETREG_RELEASED;
3082 
3083 	/* will free via class release */
3084 	class_device_put(&dev->class_dev);
3085 #else
3086 	kfree((char *)dev - dev->padded);
3087 #endif
3088 }
3089 
3090 /* Synchronize with packet receive processing. */
3091 void synchronize_net(void)
3092 {
3093 	might_sleep();
3094 	synchronize_rcu();
3095 }
3096 
3097 /**
3098  *	unregister_netdevice - remove device from the kernel
3099  *	@dev: device
3100  *
3101  *	This function shuts down a device interface and removes it
3102  *	from the kernel tables. On success 0 is returned, on a failure
3103  *	a negative errno code is returned.
3104  *
3105  *	Callers must hold the rtnl semaphore.  You may want
3106  *	unregister_netdev() instead of this.
3107  */
3108 
3109 int unregister_netdevice(struct net_device *dev)
3110 {
3111 	struct net_device *d, **dp;
3112 
3113 	BUG_ON(dev_boot_phase);
3114 	ASSERT_RTNL();
3115 
3116 	/* Some devices call without registering for initialization unwind. */
3117 	if (dev->reg_state == NETREG_UNINITIALIZED) {
3118 		printk(KERN_DEBUG "unregister_netdevice: device %s/%p never "
3119 				  "was registered\n", dev->name, dev);
3120 		return -ENODEV;
3121 	}
3122 
3123 	BUG_ON(dev->reg_state != NETREG_REGISTERED);
3124 
3125 	/* If device is running, close it first. */
3126 	if (dev->flags & IFF_UP)
3127 		dev_close(dev);
3128 
3129 	/* And unlink it from device chain. */
3130 	for (dp = &dev_base; (d = *dp) != NULL; dp = &d->next) {
3131 		if (d == dev) {
3132 			write_lock_bh(&dev_base_lock);
3133 			hlist_del(&dev->name_hlist);
3134 			hlist_del(&dev->index_hlist);
3135 			if (dev_tail == &dev->next)
3136 				dev_tail = dp;
3137 			*dp = d->next;
3138 			write_unlock_bh(&dev_base_lock);
3139 			break;
3140 		}
3141 	}
3142 	if (!d) {
3143 		printk(KERN_ERR "unregister net_device: '%s' not found\n",
3144 		       dev->name);
3145 		return -ENODEV;
3146 	}
3147 
3148 	dev->reg_state = NETREG_UNREGISTERING;
3149 
3150 	synchronize_net();
3151 
3152 	/* Shutdown queueing discipline. */
3153 	dev_shutdown(dev);
3154 
3155 
3156 	/* Notify protocols, that we are about to destroy
3157 	   this device. They should clean all the things.
3158 	*/
3159 	notifier_call_chain(&netdev_chain, NETDEV_UNREGISTER, dev);
3160 
3161 	/*
3162 	 *	Flush the multicast chain
3163 	 */
3164 	dev_mc_discard(dev);
3165 
3166 	if (dev->uninit)
3167 		dev->uninit(dev);
3168 
3169 	/* Notifier chain MUST detach us from master device. */
3170 	BUG_TRAP(!dev->master);
3171 
3172 	free_divert_blk(dev);
3173 
3174 	/* Finish processing unregister after unlock */
3175 	net_set_todo(dev);
3176 
3177 	synchronize_net();
3178 
3179 	dev_put(dev);
3180 	return 0;
3181 }
3182 
3183 /**
3184  *	unregister_netdev - remove device from the kernel
3185  *	@dev: device
3186  *
3187  *	This function shuts down a device interface and removes it
3188  *	from the kernel tables. On success 0 is returned, on a failure
3189  *	a negative errno code is returned.
3190  *
3191  *	This is just a wrapper for unregister_netdevice that takes
3192  *	the rtnl semaphore.  In general you want to use this and not
3193  *	unregister_netdevice.
3194  */
3195 void unregister_netdev(struct net_device *dev)
3196 {
3197 	rtnl_lock();
3198 	unregister_netdevice(dev);
3199 	rtnl_unlock();
3200 }
3201 
3202 EXPORT_SYMBOL(unregister_netdev);
3203 
3204 #ifdef CONFIG_HOTPLUG_CPU
3205 static int dev_cpu_callback(struct notifier_block *nfb,
3206 			    unsigned long action,
3207 			    void *ocpu)
3208 {
3209 	struct sk_buff **list_skb;
3210 	struct net_device **list_net;
3211 	struct sk_buff *skb;
3212 	unsigned int cpu, oldcpu = (unsigned long)ocpu;
3213 	struct softnet_data *sd, *oldsd;
3214 
3215 	if (action != CPU_DEAD)
3216 		return NOTIFY_OK;
3217 
3218 	local_irq_disable();
3219 	cpu = smp_processor_id();
3220 	sd = &per_cpu(softnet_data, cpu);
3221 	oldsd = &per_cpu(softnet_data, oldcpu);
3222 
3223 	/* Find end of our completion_queue. */
3224 	list_skb = &sd->completion_queue;
3225 	while (*list_skb)
3226 		list_skb = &(*list_skb)->next;
3227 	/* Append completion queue from offline CPU. */
3228 	*list_skb = oldsd->completion_queue;
3229 	oldsd->completion_queue = NULL;
3230 
3231 	/* Find end of our output_queue. */
3232 	list_net = &sd->output_queue;
3233 	while (*list_net)
3234 		list_net = &(*list_net)->next_sched;
3235 	/* Append output queue from offline CPU. */
3236 	*list_net = oldsd->output_queue;
3237 	oldsd->output_queue = NULL;
3238 
3239 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3240 	local_irq_enable();
3241 
3242 	/* Process offline CPU's input_pkt_queue */
3243 	while ((skb = __skb_dequeue(&oldsd->input_pkt_queue)))
3244 		netif_rx(skb);
3245 
3246 	return NOTIFY_OK;
3247 }
3248 #endif /* CONFIG_HOTPLUG_CPU */
3249 
3250 
3251 /*
3252  *	Initialize the DEV module. At boot time this walks the device list and
3253  *	unhooks any devices that fail to initialise (normally hardware not
3254  *	present) and leaves us with a valid list of present and active devices.
3255  *
3256  */
3257 
3258 /*
3259  *       This is called single threaded during boot, so no need
3260  *       to take the rtnl semaphore.
3261  */
3262 static int __init net_dev_init(void)
3263 {
3264 	int i, rc = -ENOMEM;
3265 
3266 	BUG_ON(!dev_boot_phase);
3267 
3268 	net_random_init();
3269 
3270 	if (dev_proc_init())
3271 		goto out;
3272 
3273 	if (netdev_sysfs_init())
3274 		goto out;
3275 
3276 	INIT_LIST_HEAD(&ptype_all);
3277 	for (i = 0; i < 16; i++)
3278 		INIT_LIST_HEAD(&ptype_base[i]);
3279 
3280 	for (i = 0; i < ARRAY_SIZE(dev_name_head); i++)
3281 		INIT_HLIST_HEAD(&dev_name_head[i]);
3282 
3283 	for (i = 0; i < ARRAY_SIZE(dev_index_head); i++)
3284 		INIT_HLIST_HEAD(&dev_index_head[i]);
3285 
3286 	/*
3287 	 *	Initialise the packet receive queues.
3288 	 */
3289 
3290 	for (i = 0; i < NR_CPUS; i++) {
3291 		struct softnet_data *queue;
3292 
3293 		queue = &per_cpu(softnet_data, i);
3294 		skb_queue_head_init(&queue->input_pkt_queue);
3295 		queue->throttle = 0;
3296 		queue->cng_level = 0;
3297 		queue->avg_blog = 10; /* arbitrary non-zero */
3298 		queue->completion_queue = NULL;
3299 		INIT_LIST_HEAD(&queue->poll_list);
3300 		set_bit(__LINK_STATE_START, &queue->backlog_dev.state);
3301 		queue->backlog_dev.weight = weight_p;
3302 		queue->backlog_dev.poll = process_backlog;
3303 		atomic_set(&queue->backlog_dev.refcnt, 1);
3304 	}
3305 
3306 #ifdef OFFLINE_SAMPLE
3307 	samp_timer.expires = jiffies + (10 * HZ);
3308 	add_timer(&samp_timer);
3309 #endif
3310 
3311 	dev_boot_phase = 0;
3312 
3313 	open_softirq(NET_TX_SOFTIRQ, net_tx_action, NULL);
3314 	open_softirq(NET_RX_SOFTIRQ, net_rx_action, NULL);
3315 
3316 	hotcpu_notifier(dev_cpu_callback, 0);
3317 	dst_init();
3318 	dev_mcast_init();
3319 	rc = 0;
3320 out:
3321 	return rc;
3322 }
3323 
3324 subsys_initcall(net_dev_init);
3325 
3326 EXPORT_SYMBOL(__dev_get_by_index);
3327 EXPORT_SYMBOL(__dev_get_by_name);
3328 EXPORT_SYMBOL(__dev_remove_pack);
3329 EXPORT_SYMBOL(__skb_linearize);
3330 EXPORT_SYMBOL(dev_add_pack);
3331 EXPORT_SYMBOL(dev_alloc_name);
3332 EXPORT_SYMBOL(dev_close);
3333 EXPORT_SYMBOL(dev_get_by_flags);
3334 EXPORT_SYMBOL(dev_get_by_index);
3335 EXPORT_SYMBOL(dev_get_by_name);
3336 EXPORT_SYMBOL(dev_ioctl);
3337 EXPORT_SYMBOL(dev_open);
3338 EXPORT_SYMBOL(dev_queue_xmit);
3339 EXPORT_SYMBOL(dev_remove_pack);
3340 EXPORT_SYMBOL(dev_set_allmulti);
3341 EXPORT_SYMBOL(dev_set_promiscuity);
3342 EXPORT_SYMBOL(dev_change_flags);
3343 EXPORT_SYMBOL(dev_set_mtu);
3344 EXPORT_SYMBOL(dev_set_mac_address);
3345 EXPORT_SYMBOL(free_netdev);
3346 EXPORT_SYMBOL(netdev_boot_setup_check);
3347 EXPORT_SYMBOL(netdev_set_master);
3348 EXPORT_SYMBOL(netdev_state_change);
3349 EXPORT_SYMBOL(netif_receive_skb);
3350 EXPORT_SYMBOL(netif_rx);
3351 EXPORT_SYMBOL(register_gifconf);
3352 EXPORT_SYMBOL(register_netdevice);
3353 EXPORT_SYMBOL(register_netdevice_notifier);
3354 EXPORT_SYMBOL(skb_checksum_help);
3355 EXPORT_SYMBOL(synchronize_net);
3356 EXPORT_SYMBOL(unregister_netdevice);
3357 EXPORT_SYMBOL(unregister_netdevice_notifier);
3358 EXPORT_SYMBOL(net_enable_timestamp);
3359 EXPORT_SYMBOL(net_disable_timestamp);
3360 EXPORT_SYMBOL(dev_get_flags);
3361 
3362 #if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
3363 EXPORT_SYMBOL(br_handle_frame_hook);
3364 EXPORT_SYMBOL(br_fdb_get_hook);
3365 EXPORT_SYMBOL(br_fdb_put_hook);
3366 #endif
3367 
3368 #ifdef CONFIG_KMOD
3369 EXPORT_SYMBOL(dev_load);
3370 #endif
3371 
3372 EXPORT_PER_CPU_SYMBOL(softnet_data);
3373