xref: /linux-6.15/net/core/dev.c (revision 3e4cd073)
1 /*
2  * 	NET3	Protocol independent device support routines.
3  *
4  *		This program is free software; you can redistribute it and/or
5  *		modify it under the terms of the GNU General Public License
6  *		as published by the Free Software Foundation; either version
7  *		2 of the License, or (at your option) any later version.
8  *
9  *	Derived from the non IP parts of dev.c 1.0.19
10  * 		Authors:	Ross Biro
11  *				Fred N. van Kempen, <[email protected]>
12  *				Mark Evans, <[email protected]>
13  *
14  *	Additional Authors:
15  *		Florian la Roche <[email protected]>
16  *		Alan Cox <[email protected]>
17  *		David Hinds <[email protected]>
18  *		Alexey Kuznetsov <[email protected]>
19  *		Adam Sulmicki <[email protected]>
20  *              Pekka Riikonen <[email protected]>
21  *
22  *	Changes:
23  *              D.J. Barrow     :       Fixed bug where dev->refcnt gets set
24  *              			to 2 if register_netdev gets called
25  *              			before net_dev_init & also removed a
26  *              			few lines of code in the process.
27  *		Alan Cox	:	device private ioctl copies fields back.
28  *		Alan Cox	:	Transmit queue code does relevant
29  *					stunts to keep the queue safe.
30  *		Alan Cox	:	Fixed double lock.
31  *		Alan Cox	:	Fixed promisc NULL pointer trap
32  *		????????	:	Support the full private ioctl range
33  *		Alan Cox	:	Moved ioctl permission check into
34  *					drivers
35  *		Tim Kordas	:	SIOCADDMULTI/SIOCDELMULTI
36  *		Alan Cox	:	100 backlog just doesn't cut it when
37  *					you start doing multicast video 8)
38  *		Alan Cox	:	Rewrote net_bh and list manager.
39  *		Alan Cox	: 	Fix ETH_P_ALL echoback lengths.
40  *		Alan Cox	:	Took out transmit every packet pass
41  *					Saved a few bytes in the ioctl handler
42  *		Alan Cox	:	Network driver sets packet type before
43  *					calling netif_rx. Saves a function
44  *					call a packet.
45  *		Alan Cox	:	Hashed net_bh()
46  *		Richard Kooijman:	Timestamp fixes.
47  *		Alan Cox	:	Wrong field in SIOCGIFDSTADDR
48  *		Alan Cox	:	Device lock protection.
49  *		Alan Cox	: 	Fixed nasty side effect of device close
50  *					changes.
51  *		Rudi Cilibrasi	:	Pass the right thing to
52  *					set_mac_address()
53  *		Dave Miller	:	32bit quantity for the device lock to
54  *					make it work out on a Sparc.
55  *		Bjorn Ekwall	:	Added KERNELD hack.
56  *		Alan Cox	:	Cleaned up the backlog initialise.
57  *		Craig Metz	:	SIOCGIFCONF fix if space for under
58  *					1 device.
59  *	    Thomas Bogendoerfer :	Return ENODEV for dev_open, if there
60  *					is no device open function.
61  *		Andi Kleen	:	Fix error reporting for SIOCGIFCONF
62  *	    Michael Chastain	:	Fix signed/unsigned for SIOCGIFCONF
63  *		Cyrus Durgin	:	Cleaned for KMOD
64  *		Adam Sulmicki   :	Bug Fix : Network Device Unload
65  *					A network device unload needs to purge
66  *					the backlog queue.
67  *	Paul Rusty Russell	:	SIOCSIFNAME
68  *              Pekka Riikonen  :	Netdev boot-time settings code
69  *              Andrew Morton   :       Make unregister_netdevice wait
70  *              			indefinitely on dev->refcnt
71  * 		J Hadi Salim	:	- Backlog queue sampling
72  *				        - netif_rx() feedback
73  */
74 
75 #include <asm/uaccess.h>
76 #include <asm/system.h>
77 #include <linux/bitops.h>
78 #include <linux/capability.h>
79 #include <linux/cpu.h>
80 #include <linux/types.h>
81 #include <linux/kernel.h>
82 #include <linux/hash.h>
83 #include <linux/slab.h>
84 #include <linux/sched.h>
85 #include <linux/mutex.h>
86 #include <linux/string.h>
87 #include <linux/mm.h>
88 #include <linux/socket.h>
89 #include <linux/sockios.h>
90 #include <linux/errno.h>
91 #include <linux/interrupt.h>
92 #include <linux/if_ether.h>
93 #include <linux/netdevice.h>
94 #include <linux/etherdevice.h>
95 #include <linux/ethtool.h>
96 #include <linux/notifier.h>
97 #include <linux/skbuff.h>
98 #include <net/net_namespace.h>
99 #include <net/sock.h>
100 #include <linux/rtnetlink.h>
101 #include <linux/proc_fs.h>
102 #include <linux/seq_file.h>
103 #include <linux/stat.h>
104 #include <net/dst.h>
105 #include <net/pkt_sched.h>
106 #include <net/checksum.h>
107 #include <net/xfrm.h>
108 #include <linux/highmem.h>
109 #include <linux/init.h>
110 #include <linux/kmod.h>
111 #include <linux/module.h>
112 #include <linux/netpoll.h>
113 #include <linux/rcupdate.h>
114 #include <linux/delay.h>
115 #include <net/wext.h>
116 #include <net/iw_handler.h>
117 #include <asm/current.h>
118 #include <linux/audit.h>
119 #include <linux/dmaengine.h>
120 #include <linux/err.h>
121 #include <linux/ctype.h>
122 #include <linux/if_arp.h>
123 #include <linux/if_vlan.h>
124 #include <linux/ip.h>
125 #include <net/ip.h>
126 #include <linux/ipv6.h>
127 #include <linux/in.h>
128 #include <linux/jhash.h>
129 #include <linux/random.h>
130 #include <trace/events/napi.h>
131 #include <trace/events/net.h>
132 #include <trace/events/skb.h>
133 #include <linux/pci.h>
134 #include <linux/inetdevice.h>
135 #include <linux/cpu_rmap.h>
136 
137 #include "net-sysfs.h"
138 
139 /* Instead of increasing this, you should create a hash table. */
140 #define MAX_GRO_SKBS 8
141 
142 /* This should be increased if a protocol with a bigger head is added. */
143 #define GRO_MAX_HEAD (MAX_HEADER + 128)
144 
145 /*
146  *	The list of packet types we will receive (as opposed to discard)
147  *	and the routines to invoke.
148  *
149  *	Why 16. Because with 16 the only overlap we get on a hash of the
150  *	low nibble of the protocol value is RARP/SNAP/X.25.
151  *
152  *      NOTE:  That is no longer true with the addition of VLAN tags.  Not
153  *             sure which should go first, but I bet it won't make much
154  *             difference if we are running VLANs.  The good news is that
155  *             this protocol won't be in the list unless compiled in, so
156  *             the average user (w/out VLANs) will not be adversely affected.
157  *             --BLG
158  *
159  *		0800	IP
160  *		8100    802.1Q VLAN
161  *		0001	802.3
162  *		0002	AX.25
163  *		0004	802.2
164  *		8035	RARP
165  *		0005	SNAP
166  *		0805	X.25
167  *		0806	ARP
168  *		8137	IPX
169  *		0009	Localtalk
170  *		86DD	IPv6
171  */
172 
173 #define PTYPE_HASH_SIZE	(16)
174 #define PTYPE_HASH_MASK	(PTYPE_HASH_SIZE - 1)
175 
176 static DEFINE_SPINLOCK(ptype_lock);
177 static struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
178 static struct list_head ptype_all __read_mostly;	/* Taps */
179 
180 /*
181  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
182  * semaphore.
183  *
184  * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
185  *
186  * Writers must hold the rtnl semaphore while they loop through the
187  * dev_base_head list, and hold dev_base_lock for writing when they do the
188  * actual updates.  This allows pure readers to access the list even
189  * while a writer is preparing to update it.
190  *
191  * To put it another way, dev_base_lock is held for writing only to
192  * protect against pure readers; the rtnl semaphore provides the
193  * protection against other writers.
194  *
195  * See, for example usages, register_netdevice() and
196  * unregister_netdevice(), which must be called with the rtnl
197  * semaphore held.
198  */
199 DEFINE_RWLOCK(dev_base_lock);
200 EXPORT_SYMBOL(dev_base_lock);
201 
202 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
203 {
204 	unsigned hash = full_name_hash(name, strnlen(name, IFNAMSIZ));
205 	return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
206 }
207 
208 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
209 {
210 	return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
211 }
212 
213 static inline void rps_lock(struct softnet_data *sd)
214 {
215 #ifdef CONFIG_RPS
216 	spin_lock(&sd->input_pkt_queue.lock);
217 #endif
218 }
219 
220 static inline void rps_unlock(struct softnet_data *sd)
221 {
222 #ifdef CONFIG_RPS
223 	spin_unlock(&sd->input_pkt_queue.lock);
224 #endif
225 }
226 
227 /* Device list insertion */
228 static int list_netdevice(struct net_device *dev)
229 {
230 	struct net *net = dev_net(dev);
231 
232 	ASSERT_RTNL();
233 
234 	write_lock_bh(&dev_base_lock);
235 	list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
236 	hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
237 	hlist_add_head_rcu(&dev->index_hlist,
238 			   dev_index_hash(net, dev->ifindex));
239 	write_unlock_bh(&dev_base_lock);
240 	return 0;
241 }
242 
243 /* Device list removal
244  * caller must respect a RCU grace period before freeing/reusing dev
245  */
246 static void unlist_netdevice(struct net_device *dev)
247 {
248 	ASSERT_RTNL();
249 
250 	/* Unlink dev from the device chain */
251 	write_lock_bh(&dev_base_lock);
252 	list_del_rcu(&dev->dev_list);
253 	hlist_del_rcu(&dev->name_hlist);
254 	hlist_del_rcu(&dev->index_hlist);
255 	write_unlock_bh(&dev_base_lock);
256 }
257 
258 /*
259  *	Our notifier list
260  */
261 
262 static RAW_NOTIFIER_HEAD(netdev_chain);
263 
264 /*
265  *	Device drivers call our routines to queue packets here. We empty the
266  *	queue in the local softnet handler.
267  */
268 
269 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
270 EXPORT_PER_CPU_SYMBOL(softnet_data);
271 
272 #ifdef CONFIG_LOCKDEP
273 /*
274  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
275  * according to dev->type
276  */
277 static const unsigned short netdev_lock_type[] =
278 	{ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
279 	 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
280 	 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
281 	 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
282 	 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
283 	 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
284 	 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
285 	 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
286 	 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
287 	 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
288 	 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
289 	 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
290 	 ARPHRD_FCFABRIC, ARPHRD_IEEE802_TR, ARPHRD_IEEE80211,
291 	 ARPHRD_IEEE80211_PRISM, ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET,
292 	 ARPHRD_PHONET_PIPE, ARPHRD_IEEE802154,
293 	 ARPHRD_VOID, ARPHRD_NONE};
294 
295 static const char *const netdev_lock_name[] =
296 	{"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
297 	 "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
298 	 "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
299 	 "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
300 	 "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
301 	 "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
302 	 "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
303 	 "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
304 	 "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
305 	 "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
306 	 "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
307 	 "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
308 	 "_xmit_FCFABRIC", "_xmit_IEEE802_TR", "_xmit_IEEE80211",
309 	 "_xmit_IEEE80211_PRISM", "_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET",
310 	 "_xmit_PHONET_PIPE", "_xmit_IEEE802154",
311 	 "_xmit_VOID", "_xmit_NONE"};
312 
313 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
314 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
315 
316 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
317 {
318 	int i;
319 
320 	for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
321 		if (netdev_lock_type[i] == dev_type)
322 			return i;
323 	/* the last key is used by default */
324 	return ARRAY_SIZE(netdev_lock_type) - 1;
325 }
326 
327 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
328 						 unsigned short dev_type)
329 {
330 	int i;
331 
332 	i = netdev_lock_pos(dev_type);
333 	lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
334 				   netdev_lock_name[i]);
335 }
336 
337 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
338 {
339 	int i;
340 
341 	i = netdev_lock_pos(dev->type);
342 	lockdep_set_class_and_name(&dev->addr_list_lock,
343 				   &netdev_addr_lock_key[i],
344 				   netdev_lock_name[i]);
345 }
346 #else
347 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
348 						 unsigned short dev_type)
349 {
350 }
351 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
352 {
353 }
354 #endif
355 
356 /*******************************************************************************
357 
358 		Protocol management and registration routines
359 
360 *******************************************************************************/
361 
362 /*
363  *	Add a protocol ID to the list. Now that the input handler is
364  *	smarter we can dispense with all the messy stuff that used to be
365  *	here.
366  *
367  *	BEWARE!!! Protocol handlers, mangling input packets,
368  *	MUST BE last in hash buckets and checking protocol handlers
369  *	MUST start from promiscuous ptype_all chain in net_bh.
370  *	It is true now, do not change it.
371  *	Explanation follows: if protocol handler, mangling packet, will
372  *	be the first on list, it is not able to sense, that packet
373  *	is cloned and should be copied-on-write, so that it will
374  *	change it and subsequent readers will get broken packet.
375  *							--ANK (980803)
376  */
377 
378 static inline struct list_head *ptype_head(const struct packet_type *pt)
379 {
380 	if (pt->type == htons(ETH_P_ALL))
381 		return &ptype_all;
382 	else
383 		return &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
384 }
385 
386 /**
387  *	dev_add_pack - add packet handler
388  *	@pt: packet type declaration
389  *
390  *	Add a protocol handler to the networking stack. The passed &packet_type
391  *	is linked into kernel lists and may not be freed until it has been
392  *	removed from the kernel lists.
393  *
394  *	This call does not sleep therefore it can not
395  *	guarantee all CPU's that are in middle of receiving packets
396  *	will see the new packet type (until the next received packet).
397  */
398 
399 void dev_add_pack(struct packet_type *pt)
400 {
401 	struct list_head *head = ptype_head(pt);
402 
403 	spin_lock(&ptype_lock);
404 	list_add_rcu(&pt->list, head);
405 	spin_unlock(&ptype_lock);
406 }
407 EXPORT_SYMBOL(dev_add_pack);
408 
409 /**
410  *	__dev_remove_pack	 - remove packet handler
411  *	@pt: packet type declaration
412  *
413  *	Remove a protocol handler that was previously added to the kernel
414  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
415  *	from the kernel lists and can be freed or reused once this function
416  *	returns.
417  *
418  *      The packet type might still be in use by receivers
419  *	and must not be freed until after all the CPU's have gone
420  *	through a quiescent state.
421  */
422 void __dev_remove_pack(struct packet_type *pt)
423 {
424 	struct list_head *head = ptype_head(pt);
425 	struct packet_type *pt1;
426 
427 	spin_lock(&ptype_lock);
428 
429 	list_for_each_entry(pt1, head, list) {
430 		if (pt == pt1) {
431 			list_del_rcu(&pt->list);
432 			goto out;
433 		}
434 	}
435 
436 	printk(KERN_WARNING "dev_remove_pack: %p not found.\n", pt);
437 out:
438 	spin_unlock(&ptype_lock);
439 }
440 EXPORT_SYMBOL(__dev_remove_pack);
441 
442 /**
443  *	dev_remove_pack	 - remove packet handler
444  *	@pt: packet type declaration
445  *
446  *	Remove a protocol handler that was previously added to the kernel
447  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
448  *	from the kernel lists and can be freed or reused once this function
449  *	returns.
450  *
451  *	This call sleeps to guarantee that no CPU is looking at the packet
452  *	type after return.
453  */
454 void dev_remove_pack(struct packet_type *pt)
455 {
456 	__dev_remove_pack(pt);
457 
458 	synchronize_net();
459 }
460 EXPORT_SYMBOL(dev_remove_pack);
461 
462 /******************************************************************************
463 
464 		      Device Boot-time Settings Routines
465 
466 *******************************************************************************/
467 
468 /* Boot time configuration table */
469 static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX];
470 
471 /**
472  *	netdev_boot_setup_add	- add new setup entry
473  *	@name: name of the device
474  *	@map: configured settings for the device
475  *
476  *	Adds new setup entry to the dev_boot_setup list.  The function
477  *	returns 0 on error and 1 on success.  This is a generic routine to
478  *	all netdevices.
479  */
480 static int netdev_boot_setup_add(char *name, struct ifmap *map)
481 {
482 	struct netdev_boot_setup *s;
483 	int i;
484 
485 	s = dev_boot_setup;
486 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
487 		if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
488 			memset(s[i].name, 0, sizeof(s[i].name));
489 			strlcpy(s[i].name, name, IFNAMSIZ);
490 			memcpy(&s[i].map, map, sizeof(s[i].map));
491 			break;
492 		}
493 	}
494 
495 	return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1;
496 }
497 
498 /**
499  *	netdev_boot_setup_check	- check boot time settings
500  *	@dev: the netdevice
501  *
502  * 	Check boot time settings for the device.
503  *	The found settings are set for the device to be used
504  *	later in the device probing.
505  *	Returns 0 if no settings found, 1 if they are.
506  */
507 int netdev_boot_setup_check(struct net_device *dev)
508 {
509 	struct netdev_boot_setup *s = dev_boot_setup;
510 	int i;
511 
512 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
513 		if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
514 		    !strcmp(dev->name, s[i].name)) {
515 			dev->irq 	= s[i].map.irq;
516 			dev->base_addr 	= s[i].map.base_addr;
517 			dev->mem_start 	= s[i].map.mem_start;
518 			dev->mem_end 	= s[i].map.mem_end;
519 			return 1;
520 		}
521 	}
522 	return 0;
523 }
524 EXPORT_SYMBOL(netdev_boot_setup_check);
525 
526 
527 /**
528  *	netdev_boot_base	- get address from boot time settings
529  *	@prefix: prefix for network device
530  *	@unit: id for network device
531  *
532  * 	Check boot time settings for the base address of device.
533  *	The found settings are set for the device to be used
534  *	later in the device probing.
535  *	Returns 0 if no settings found.
536  */
537 unsigned long netdev_boot_base(const char *prefix, int unit)
538 {
539 	const struct netdev_boot_setup *s = dev_boot_setup;
540 	char name[IFNAMSIZ];
541 	int i;
542 
543 	sprintf(name, "%s%d", prefix, unit);
544 
545 	/*
546 	 * If device already registered then return base of 1
547 	 * to indicate not to probe for this interface
548 	 */
549 	if (__dev_get_by_name(&init_net, name))
550 		return 1;
551 
552 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++)
553 		if (!strcmp(name, s[i].name))
554 			return s[i].map.base_addr;
555 	return 0;
556 }
557 
558 /*
559  * Saves at boot time configured settings for any netdevice.
560  */
561 int __init netdev_boot_setup(char *str)
562 {
563 	int ints[5];
564 	struct ifmap map;
565 
566 	str = get_options(str, ARRAY_SIZE(ints), ints);
567 	if (!str || !*str)
568 		return 0;
569 
570 	/* Save settings */
571 	memset(&map, 0, sizeof(map));
572 	if (ints[0] > 0)
573 		map.irq = ints[1];
574 	if (ints[0] > 1)
575 		map.base_addr = ints[2];
576 	if (ints[0] > 2)
577 		map.mem_start = ints[3];
578 	if (ints[0] > 3)
579 		map.mem_end = ints[4];
580 
581 	/* Add new entry to the list */
582 	return netdev_boot_setup_add(str, &map);
583 }
584 
585 __setup("netdev=", netdev_boot_setup);
586 
587 /*******************************************************************************
588 
589 			    Device Interface Subroutines
590 
591 *******************************************************************************/
592 
593 /**
594  *	__dev_get_by_name	- find a device by its name
595  *	@net: the applicable net namespace
596  *	@name: name to find
597  *
598  *	Find an interface by name. Must be called under RTNL semaphore
599  *	or @dev_base_lock. If the name is found a pointer to the device
600  *	is returned. If the name is not found then %NULL is returned. The
601  *	reference counters are not incremented so the caller must be
602  *	careful with locks.
603  */
604 
605 struct net_device *__dev_get_by_name(struct net *net, const char *name)
606 {
607 	struct hlist_node *p;
608 	struct net_device *dev;
609 	struct hlist_head *head = dev_name_hash(net, name);
610 
611 	hlist_for_each_entry(dev, p, head, name_hlist)
612 		if (!strncmp(dev->name, name, IFNAMSIZ))
613 			return dev;
614 
615 	return NULL;
616 }
617 EXPORT_SYMBOL(__dev_get_by_name);
618 
619 /**
620  *	dev_get_by_name_rcu	- find a device by its name
621  *	@net: the applicable net namespace
622  *	@name: name to find
623  *
624  *	Find an interface by name.
625  *	If the name is found a pointer to the device is returned.
626  * 	If the name is not found then %NULL is returned.
627  *	The reference counters are not incremented so the caller must be
628  *	careful with locks. The caller must hold RCU lock.
629  */
630 
631 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
632 {
633 	struct hlist_node *p;
634 	struct net_device *dev;
635 	struct hlist_head *head = dev_name_hash(net, name);
636 
637 	hlist_for_each_entry_rcu(dev, p, head, name_hlist)
638 		if (!strncmp(dev->name, name, IFNAMSIZ))
639 			return dev;
640 
641 	return NULL;
642 }
643 EXPORT_SYMBOL(dev_get_by_name_rcu);
644 
645 /**
646  *	dev_get_by_name		- find a device by its name
647  *	@net: the applicable net namespace
648  *	@name: name to find
649  *
650  *	Find an interface by name. This can be called from any
651  *	context and does its own locking. The returned handle has
652  *	the usage count incremented and the caller must use dev_put() to
653  *	release it when it is no longer needed. %NULL is returned if no
654  *	matching device is found.
655  */
656 
657 struct net_device *dev_get_by_name(struct net *net, const char *name)
658 {
659 	struct net_device *dev;
660 
661 	rcu_read_lock();
662 	dev = dev_get_by_name_rcu(net, name);
663 	if (dev)
664 		dev_hold(dev);
665 	rcu_read_unlock();
666 	return dev;
667 }
668 EXPORT_SYMBOL(dev_get_by_name);
669 
670 /**
671  *	__dev_get_by_index - find a device by its ifindex
672  *	@net: the applicable net namespace
673  *	@ifindex: index of device
674  *
675  *	Search for an interface by index. Returns %NULL if the device
676  *	is not found or a pointer to the device. The device has not
677  *	had its reference counter increased so the caller must be careful
678  *	about locking. The caller must hold either the RTNL semaphore
679  *	or @dev_base_lock.
680  */
681 
682 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
683 {
684 	struct hlist_node *p;
685 	struct net_device *dev;
686 	struct hlist_head *head = dev_index_hash(net, ifindex);
687 
688 	hlist_for_each_entry(dev, p, head, index_hlist)
689 		if (dev->ifindex == ifindex)
690 			return dev;
691 
692 	return NULL;
693 }
694 EXPORT_SYMBOL(__dev_get_by_index);
695 
696 /**
697  *	dev_get_by_index_rcu - find a device by its ifindex
698  *	@net: the applicable net namespace
699  *	@ifindex: index of device
700  *
701  *	Search for an interface by index. Returns %NULL if the device
702  *	is not found or a pointer to the device. The device has not
703  *	had its reference counter increased so the caller must be careful
704  *	about locking. The caller must hold RCU lock.
705  */
706 
707 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
708 {
709 	struct hlist_node *p;
710 	struct net_device *dev;
711 	struct hlist_head *head = dev_index_hash(net, ifindex);
712 
713 	hlist_for_each_entry_rcu(dev, p, head, index_hlist)
714 		if (dev->ifindex == ifindex)
715 			return dev;
716 
717 	return NULL;
718 }
719 EXPORT_SYMBOL(dev_get_by_index_rcu);
720 
721 
722 /**
723  *	dev_get_by_index - find a device by its ifindex
724  *	@net: the applicable net namespace
725  *	@ifindex: index of device
726  *
727  *	Search for an interface by index. Returns NULL if the device
728  *	is not found or a pointer to the device. The device returned has
729  *	had a reference added and the pointer is safe until the user calls
730  *	dev_put to indicate they have finished with it.
731  */
732 
733 struct net_device *dev_get_by_index(struct net *net, int ifindex)
734 {
735 	struct net_device *dev;
736 
737 	rcu_read_lock();
738 	dev = dev_get_by_index_rcu(net, ifindex);
739 	if (dev)
740 		dev_hold(dev);
741 	rcu_read_unlock();
742 	return dev;
743 }
744 EXPORT_SYMBOL(dev_get_by_index);
745 
746 /**
747  *	dev_getbyhwaddr_rcu - find a device by its hardware address
748  *	@net: the applicable net namespace
749  *	@type: media type of device
750  *	@ha: hardware address
751  *
752  *	Search for an interface by MAC address. Returns NULL if the device
753  *	is not found or a pointer to the device.
754  *	The caller must hold RCU or RTNL.
755  *	The returned device has not had its ref count increased
756  *	and the caller must therefore be careful about locking
757  *
758  */
759 
760 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
761 				       const char *ha)
762 {
763 	struct net_device *dev;
764 
765 	for_each_netdev_rcu(net, dev)
766 		if (dev->type == type &&
767 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
768 			return dev;
769 
770 	return NULL;
771 }
772 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
773 
774 struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type)
775 {
776 	struct net_device *dev;
777 
778 	ASSERT_RTNL();
779 	for_each_netdev(net, dev)
780 		if (dev->type == type)
781 			return dev;
782 
783 	return NULL;
784 }
785 EXPORT_SYMBOL(__dev_getfirstbyhwtype);
786 
787 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
788 {
789 	struct net_device *dev, *ret = NULL;
790 
791 	rcu_read_lock();
792 	for_each_netdev_rcu(net, dev)
793 		if (dev->type == type) {
794 			dev_hold(dev);
795 			ret = dev;
796 			break;
797 		}
798 	rcu_read_unlock();
799 	return ret;
800 }
801 EXPORT_SYMBOL(dev_getfirstbyhwtype);
802 
803 /**
804  *	dev_get_by_flags_rcu - find any device with given flags
805  *	@net: the applicable net namespace
806  *	@if_flags: IFF_* values
807  *	@mask: bitmask of bits in if_flags to check
808  *
809  *	Search for any interface with the given flags. Returns NULL if a device
810  *	is not found or a pointer to the device. Must be called inside
811  *	rcu_read_lock(), and result refcount is unchanged.
812  */
813 
814 struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags,
815 				    unsigned short mask)
816 {
817 	struct net_device *dev, *ret;
818 
819 	ret = NULL;
820 	for_each_netdev_rcu(net, dev) {
821 		if (((dev->flags ^ if_flags) & mask) == 0) {
822 			ret = dev;
823 			break;
824 		}
825 	}
826 	return ret;
827 }
828 EXPORT_SYMBOL(dev_get_by_flags_rcu);
829 
830 /**
831  *	dev_valid_name - check if name is okay for network device
832  *	@name: name string
833  *
834  *	Network device names need to be valid file names to
835  *	to allow sysfs to work.  We also disallow any kind of
836  *	whitespace.
837  */
838 int dev_valid_name(const char *name)
839 {
840 	if (*name == '\0')
841 		return 0;
842 	if (strlen(name) >= IFNAMSIZ)
843 		return 0;
844 	if (!strcmp(name, ".") || !strcmp(name, ".."))
845 		return 0;
846 
847 	while (*name) {
848 		if (*name == '/' || isspace(*name))
849 			return 0;
850 		name++;
851 	}
852 	return 1;
853 }
854 EXPORT_SYMBOL(dev_valid_name);
855 
856 /**
857  *	__dev_alloc_name - allocate a name for a device
858  *	@net: network namespace to allocate the device name in
859  *	@name: name format string
860  *	@buf:  scratch buffer and result name string
861  *
862  *	Passed a format string - eg "lt%d" it will try and find a suitable
863  *	id. It scans list of devices to build up a free map, then chooses
864  *	the first empty slot. The caller must hold the dev_base or rtnl lock
865  *	while allocating the name and adding the device in order to avoid
866  *	duplicates.
867  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
868  *	Returns the number of the unit assigned or a negative errno code.
869  */
870 
871 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
872 {
873 	int i = 0;
874 	const char *p;
875 	const int max_netdevices = 8*PAGE_SIZE;
876 	unsigned long *inuse;
877 	struct net_device *d;
878 
879 	p = strnchr(name, IFNAMSIZ-1, '%');
880 	if (p) {
881 		/*
882 		 * Verify the string as this thing may have come from
883 		 * the user.  There must be either one "%d" and no other "%"
884 		 * characters.
885 		 */
886 		if (p[1] != 'd' || strchr(p + 2, '%'))
887 			return -EINVAL;
888 
889 		/* Use one page as a bit array of possible slots */
890 		inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
891 		if (!inuse)
892 			return -ENOMEM;
893 
894 		for_each_netdev(net, d) {
895 			if (!sscanf(d->name, name, &i))
896 				continue;
897 			if (i < 0 || i >= max_netdevices)
898 				continue;
899 
900 			/*  avoid cases where sscanf is not exact inverse of printf */
901 			snprintf(buf, IFNAMSIZ, name, i);
902 			if (!strncmp(buf, d->name, IFNAMSIZ))
903 				set_bit(i, inuse);
904 		}
905 
906 		i = find_first_zero_bit(inuse, max_netdevices);
907 		free_page((unsigned long) inuse);
908 	}
909 
910 	if (buf != name)
911 		snprintf(buf, IFNAMSIZ, name, i);
912 	if (!__dev_get_by_name(net, buf))
913 		return i;
914 
915 	/* It is possible to run out of possible slots
916 	 * when the name is long and there isn't enough space left
917 	 * for the digits, or if all bits are used.
918 	 */
919 	return -ENFILE;
920 }
921 
922 /**
923  *	dev_alloc_name - allocate a name for a device
924  *	@dev: device
925  *	@name: name format string
926  *
927  *	Passed a format string - eg "lt%d" it will try and find a suitable
928  *	id. It scans list of devices to build up a free map, then chooses
929  *	the first empty slot. The caller must hold the dev_base or rtnl lock
930  *	while allocating the name and adding the device in order to avoid
931  *	duplicates.
932  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
933  *	Returns the number of the unit assigned or a negative errno code.
934  */
935 
936 int dev_alloc_name(struct net_device *dev, const char *name)
937 {
938 	char buf[IFNAMSIZ];
939 	struct net *net;
940 	int ret;
941 
942 	BUG_ON(!dev_net(dev));
943 	net = dev_net(dev);
944 	ret = __dev_alloc_name(net, name, buf);
945 	if (ret >= 0)
946 		strlcpy(dev->name, buf, IFNAMSIZ);
947 	return ret;
948 }
949 EXPORT_SYMBOL(dev_alloc_name);
950 
951 static int dev_get_valid_name(struct net_device *dev, const char *name)
952 {
953 	struct net *net;
954 
955 	BUG_ON(!dev_net(dev));
956 	net = dev_net(dev);
957 
958 	if (!dev_valid_name(name))
959 		return -EINVAL;
960 
961 	if (strchr(name, '%'))
962 		return dev_alloc_name(dev, name);
963 	else if (__dev_get_by_name(net, name))
964 		return -EEXIST;
965 	else if (dev->name != name)
966 		strlcpy(dev->name, name, IFNAMSIZ);
967 
968 	return 0;
969 }
970 
971 /**
972  *	dev_change_name - change name of a device
973  *	@dev: device
974  *	@newname: name (or format string) must be at least IFNAMSIZ
975  *
976  *	Change name of a device, can pass format strings "eth%d".
977  *	for wildcarding.
978  */
979 int dev_change_name(struct net_device *dev, const char *newname)
980 {
981 	char oldname[IFNAMSIZ];
982 	int err = 0;
983 	int ret;
984 	struct net *net;
985 
986 	ASSERT_RTNL();
987 	BUG_ON(!dev_net(dev));
988 
989 	net = dev_net(dev);
990 	if (dev->flags & IFF_UP)
991 		return -EBUSY;
992 
993 	if (strncmp(newname, dev->name, IFNAMSIZ) == 0)
994 		return 0;
995 
996 	memcpy(oldname, dev->name, IFNAMSIZ);
997 
998 	err = dev_get_valid_name(dev, newname);
999 	if (err < 0)
1000 		return err;
1001 
1002 rollback:
1003 	ret = device_rename(&dev->dev, dev->name);
1004 	if (ret) {
1005 		memcpy(dev->name, oldname, IFNAMSIZ);
1006 		return ret;
1007 	}
1008 
1009 	write_lock_bh(&dev_base_lock);
1010 	hlist_del_rcu(&dev->name_hlist);
1011 	write_unlock_bh(&dev_base_lock);
1012 
1013 	synchronize_rcu();
1014 
1015 	write_lock_bh(&dev_base_lock);
1016 	hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
1017 	write_unlock_bh(&dev_base_lock);
1018 
1019 	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1020 	ret = notifier_to_errno(ret);
1021 
1022 	if (ret) {
1023 		/* err >= 0 after dev_alloc_name() or stores the first errno */
1024 		if (err >= 0) {
1025 			err = ret;
1026 			memcpy(dev->name, oldname, IFNAMSIZ);
1027 			goto rollback;
1028 		} else {
1029 			printk(KERN_ERR
1030 			       "%s: name change rollback failed: %d.\n",
1031 			       dev->name, ret);
1032 		}
1033 	}
1034 
1035 	return err;
1036 }
1037 
1038 /**
1039  *	dev_set_alias - change ifalias of a device
1040  *	@dev: device
1041  *	@alias: name up to IFALIASZ
1042  *	@len: limit of bytes to copy from info
1043  *
1044  *	Set ifalias for a device,
1045  */
1046 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1047 {
1048 	ASSERT_RTNL();
1049 
1050 	if (len >= IFALIASZ)
1051 		return -EINVAL;
1052 
1053 	if (!len) {
1054 		if (dev->ifalias) {
1055 			kfree(dev->ifalias);
1056 			dev->ifalias = NULL;
1057 		}
1058 		return 0;
1059 	}
1060 
1061 	dev->ifalias = krealloc(dev->ifalias, len + 1, GFP_KERNEL);
1062 	if (!dev->ifalias)
1063 		return -ENOMEM;
1064 
1065 	strlcpy(dev->ifalias, alias, len+1);
1066 	return len;
1067 }
1068 
1069 
1070 /**
1071  *	netdev_features_change - device changes features
1072  *	@dev: device to cause notification
1073  *
1074  *	Called to indicate a device has changed features.
1075  */
1076 void netdev_features_change(struct net_device *dev)
1077 {
1078 	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1079 }
1080 EXPORT_SYMBOL(netdev_features_change);
1081 
1082 /**
1083  *	netdev_state_change - device changes state
1084  *	@dev: device to cause notification
1085  *
1086  *	Called to indicate a device has changed state. This function calls
1087  *	the notifier chains for netdev_chain and sends a NEWLINK message
1088  *	to the routing socket.
1089  */
1090 void netdev_state_change(struct net_device *dev)
1091 {
1092 	if (dev->flags & IFF_UP) {
1093 		call_netdevice_notifiers(NETDEV_CHANGE, dev);
1094 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
1095 	}
1096 }
1097 EXPORT_SYMBOL(netdev_state_change);
1098 
1099 int netdev_bonding_change(struct net_device *dev, unsigned long event)
1100 {
1101 	return call_netdevice_notifiers(event, dev);
1102 }
1103 EXPORT_SYMBOL(netdev_bonding_change);
1104 
1105 /**
1106  *	dev_load 	- load a network module
1107  *	@net: the applicable net namespace
1108  *	@name: name of interface
1109  *
1110  *	If a network interface is not present and the process has suitable
1111  *	privileges this function loads the module. If module loading is not
1112  *	available in this kernel then it becomes a nop.
1113  */
1114 
1115 void dev_load(struct net *net, const char *name)
1116 {
1117 	struct net_device *dev;
1118 	int no_module;
1119 
1120 	rcu_read_lock();
1121 	dev = dev_get_by_name_rcu(net, name);
1122 	rcu_read_unlock();
1123 
1124 	no_module = !dev;
1125 	if (no_module && capable(CAP_NET_ADMIN))
1126 		no_module = request_module("netdev-%s", name);
1127 	if (no_module && capable(CAP_SYS_MODULE)) {
1128 		if (!request_module("%s", name))
1129 			pr_err("Loading kernel module for a network device "
1130 "with CAP_SYS_MODULE (deprecated).  Use CAP_NET_ADMIN and alias netdev-%s "
1131 "instead\n", name);
1132 	}
1133 }
1134 EXPORT_SYMBOL(dev_load);
1135 
1136 static int __dev_open(struct net_device *dev)
1137 {
1138 	const struct net_device_ops *ops = dev->netdev_ops;
1139 	int ret;
1140 
1141 	ASSERT_RTNL();
1142 
1143 	if (!netif_device_present(dev))
1144 		return -ENODEV;
1145 
1146 	ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
1147 	ret = notifier_to_errno(ret);
1148 	if (ret)
1149 		return ret;
1150 
1151 	set_bit(__LINK_STATE_START, &dev->state);
1152 
1153 	if (ops->ndo_validate_addr)
1154 		ret = ops->ndo_validate_addr(dev);
1155 
1156 	if (!ret && ops->ndo_open)
1157 		ret = ops->ndo_open(dev);
1158 
1159 	if (ret)
1160 		clear_bit(__LINK_STATE_START, &dev->state);
1161 	else {
1162 		dev->flags |= IFF_UP;
1163 		net_dmaengine_get();
1164 		dev_set_rx_mode(dev);
1165 		dev_activate(dev);
1166 	}
1167 
1168 	return ret;
1169 }
1170 
1171 /**
1172  *	dev_open	- prepare an interface for use.
1173  *	@dev:	device to open
1174  *
1175  *	Takes a device from down to up state. The device's private open
1176  *	function is invoked and then the multicast lists are loaded. Finally
1177  *	the device is moved into the up state and a %NETDEV_UP message is
1178  *	sent to the netdev notifier chain.
1179  *
1180  *	Calling this function on an active interface is a nop. On a failure
1181  *	a negative errno code is returned.
1182  */
1183 int dev_open(struct net_device *dev)
1184 {
1185 	int ret;
1186 
1187 	if (dev->flags & IFF_UP)
1188 		return 0;
1189 
1190 	ret = __dev_open(dev);
1191 	if (ret < 0)
1192 		return ret;
1193 
1194 	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1195 	call_netdevice_notifiers(NETDEV_UP, dev);
1196 
1197 	return ret;
1198 }
1199 EXPORT_SYMBOL(dev_open);
1200 
1201 static int __dev_close_many(struct list_head *head)
1202 {
1203 	struct net_device *dev;
1204 
1205 	ASSERT_RTNL();
1206 	might_sleep();
1207 
1208 	list_for_each_entry(dev, head, unreg_list) {
1209 		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1210 
1211 		clear_bit(__LINK_STATE_START, &dev->state);
1212 
1213 		/* Synchronize to scheduled poll. We cannot touch poll list, it
1214 		 * can be even on different cpu. So just clear netif_running().
1215 		 *
1216 		 * dev->stop() will invoke napi_disable() on all of it's
1217 		 * napi_struct instances on this device.
1218 		 */
1219 		smp_mb__after_clear_bit(); /* Commit netif_running(). */
1220 	}
1221 
1222 	dev_deactivate_many(head);
1223 
1224 	list_for_each_entry(dev, head, unreg_list) {
1225 		const struct net_device_ops *ops = dev->netdev_ops;
1226 
1227 		/*
1228 		 *	Call the device specific close. This cannot fail.
1229 		 *	Only if device is UP
1230 		 *
1231 		 *	We allow it to be called even after a DETACH hot-plug
1232 		 *	event.
1233 		 */
1234 		if (ops->ndo_stop)
1235 			ops->ndo_stop(dev);
1236 
1237 		dev->flags &= ~IFF_UP;
1238 		net_dmaengine_put();
1239 	}
1240 
1241 	return 0;
1242 }
1243 
1244 static int __dev_close(struct net_device *dev)
1245 {
1246 	int retval;
1247 	LIST_HEAD(single);
1248 
1249 	list_add(&dev->unreg_list, &single);
1250 	retval = __dev_close_many(&single);
1251 	list_del(&single);
1252 	return retval;
1253 }
1254 
1255 static int dev_close_many(struct list_head *head)
1256 {
1257 	struct net_device *dev, *tmp;
1258 	LIST_HEAD(tmp_list);
1259 
1260 	list_for_each_entry_safe(dev, tmp, head, unreg_list)
1261 		if (!(dev->flags & IFF_UP))
1262 			list_move(&dev->unreg_list, &tmp_list);
1263 
1264 	__dev_close_many(head);
1265 
1266 	list_for_each_entry(dev, head, unreg_list) {
1267 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1268 		call_netdevice_notifiers(NETDEV_DOWN, dev);
1269 	}
1270 
1271 	/* rollback_registered_many needs the complete original list */
1272 	list_splice(&tmp_list, head);
1273 	return 0;
1274 }
1275 
1276 /**
1277  *	dev_close - shutdown an interface.
1278  *	@dev: device to shutdown
1279  *
1280  *	This function moves an active device into down state. A
1281  *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1282  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1283  *	chain.
1284  */
1285 int dev_close(struct net_device *dev)
1286 {
1287 	if (dev->flags & IFF_UP) {
1288 		LIST_HEAD(single);
1289 
1290 		list_add(&dev->unreg_list, &single);
1291 		dev_close_many(&single);
1292 		list_del(&single);
1293 	}
1294 	return 0;
1295 }
1296 EXPORT_SYMBOL(dev_close);
1297 
1298 
1299 /**
1300  *	dev_disable_lro - disable Large Receive Offload on a device
1301  *	@dev: device
1302  *
1303  *	Disable Large Receive Offload (LRO) on a net device.  Must be
1304  *	called under RTNL.  This is needed if received packets may be
1305  *	forwarded to another interface.
1306  */
1307 void dev_disable_lro(struct net_device *dev)
1308 {
1309 	u32 flags;
1310 
1311 	if (dev->ethtool_ops && dev->ethtool_ops->get_flags)
1312 		flags = dev->ethtool_ops->get_flags(dev);
1313 	else
1314 		flags = ethtool_op_get_flags(dev);
1315 
1316 	if (!(flags & ETH_FLAG_LRO))
1317 		return;
1318 
1319 	__ethtool_set_flags(dev, flags & ~ETH_FLAG_LRO);
1320 	if (unlikely(dev->features & NETIF_F_LRO))
1321 		netdev_WARN(dev, "failed to disable LRO!\n");
1322 }
1323 EXPORT_SYMBOL(dev_disable_lro);
1324 
1325 
1326 static int dev_boot_phase = 1;
1327 
1328 /**
1329  *	register_netdevice_notifier - register a network notifier block
1330  *	@nb: notifier
1331  *
1332  *	Register a notifier to be called when network device events occur.
1333  *	The notifier passed is linked into the kernel structures and must
1334  *	not be reused until it has been unregistered. A negative errno code
1335  *	is returned on a failure.
1336  *
1337  * 	When registered all registration and up events are replayed
1338  *	to the new notifier to allow device to have a race free
1339  *	view of the network device list.
1340  */
1341 
1342 int register_netdevice_notifier(struct notifier_block *nb)
1343 {
1344 	struct net_device *dev;
1345 	struct net_device *last;
1346 	struct net *net;
1347 	int err;
1348 
1349 	rtnl_lock();
1350 	err = raw_notifier_chain_register(&netdev_chain, nb);
1351 	if (err)
1352 		goto unlock;
1353 	if (dev_boot_phase)
1354 		goto unlock;
1355 	for_each_net(net) {
1356 		for_each_netdev(net, dev) {
1357 			err = nb->notifier_call(nb, NETDEV_REGISTER, dev);
1358 			err = notifier_to_errno(err);
1359 			if (err)
1360 				goto rollback;
1361 
1362 			if (!(dev->flags & IFF_UP))
1363 				continue;
1364 
1365 			nb->notifier_call(nb, NETDEV_UP, dev);
1366 		}
1367 	}
1368 
1369 unlock:
1370 	rtnl_unlock();
1371 	return err;
1372 
1373 rollback:
1374 	last = dev;
1375 	for_each_net(net) {
1376 		for_each_netdev(net, dev) {
1377 			if (dev == last)
1378 				break;
1379 
1380 			if (dev->flags & IFF_UP) {
1381 				nb->notifier_call(nb, NETDEV_GOING_DOWN, dev);
1382 				nb->notifier_call(nb, NETDEV_DOWN, dev);
1383 			}
1384 			nb->notifier_call(nb, NETDEV_UNREGISTER, dev);
1385 			nb->notifier_call(nb, NETDEV_UNREGISTER_BATCH, dev);
1386 		}
1387 	}
1388 
1389 	raw_notifier_chain_unregister(&netdev_chain, nb);
1390 	goto unlock;
1391 }
1392 EXPORT_SYMBOL(register_netdevice_notifier);
1393 
1394 /**
1395  *	unregister_netdevice_notifier - unregister a network notifier block
1396  *	@nb: notifier
1397  *
1398  *	Unregister a notifier previously registered by
1399  *	register_netdevice_notifier(). The notifier is unlinked into the
1400  *	kernel structures and may then be reused. A negative errno code
1401  *	is returned on a failure.
1402  */
1403 
1404 int unregister_netdevice_notifier(struct notifier_block *nb)
1405 {
1406 	int err;
1407 
1408 	rtnl_lock();
1409 	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1410 	rtnl_unlock();
1411 	return err;
1412 }
1413 EXPORT_SYMBOL(unregister_netdevice_notifier);
1414 
1415 /**
1416  *	call_netdevice_notifiers - call all network notifier blocks
1417  *      @val: value passed unmodified to notifier function
1418  *      @dev: net_device pointer passed unmodified to notifier function
1419  *
1420  *	Call all network notifier blocks.  Parameters and return value
1421  *	are as for raw_notifier_call_chain().
1422  */
1423 
1424 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1425 {
1426 	ASSERT_RTNL();
1427 	return raw_notifier_call_chain(&netdev_chain, val, dev);
1428 }
1429 EXPORT_SYMBOL(call_netdevice_notifiers);
1430 
1431 /* When > 0 there are consumers of rx skb time stamps */
1432 static atomic_t netstamp_needed = ATOMIC_INIT(0);
1433 
1434 void net_enable_timestamp(void)
1435 {
1436 	atomic_inc(&netstamp_needed);
1437 }
1438 EXPORT_SYMBOL(net_enable_timestamp);
1439 
1440 void net_disable_timestamp(void)
1441 {
1442 	atomic_dec(&netstamp_needed);
1443 }
1444 EXPORT_SYMBOL(net_disable_timestamp);
1445 
1446 static inline void net_timestamp_set(struct sk_buff *skb)
1447 {
1448 	if (atomic_read(&netstamp_needed))
1449 		__net_timestamp(skb);
1450 	else
1451 		skb->tstamp.tv64 = 0;
1452 }
1453 
1454 static inline void net_timestamp_check(struct sk_buff *skb)
1455 {
1456 	if (!skb->tstamp.tv64 && atomic_read(&netstamp_needed))
1457 		__net_timestamp(skb);
1458 }
1459 
1460 static inline bool is_skb_forwardable(struct net_device *dev,
1461 				      struct sk_buff *skb)
1462 {
1463 	unsigned int len;
1464 
1465 	if (!(dev->flags & IFF_UP))
1466 		return false;
1467 
1468 	len = dev->mtu + dev->hard_header_len + VLAN_HLEN;
1469 	if (skb->len <= len)
1470 		return true;
1471 
1472 	/* if TSO is enabled, we don't care about the length as the packet
1473 	 * could be forwarded without being segmented before
1474 	 */
1475 	if (skb_is_gso(skb))
1476 		return true;
1477 
1478 	return false;
1479 }
1480 
1481 /**
1482  * dev_forward_skb - loopback an skb to another netif
1483  *
1484  * @dev: destination network device
1485  * @skb: buffer to forward
1486  *
1487  * return values:
1488  *	NET_RX_SUCCESS	(no congestion)
1489  *	NET_RX_DROP     (packet was dropped, but freed)
1490  *
1491  * dev_forward_skb can be used for injecting an skb from the
1492  * start_xmit function of one device into the receive queue
1493  * of another device.
1494  *
1495  * The receiving device may be in another namespace, so
1496  * we have to clear all information in the skb that could
1497  * impact namespace isolation.
1498  */
1499 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
1500 {
1501 	skb_orphan(skb);
1502 	nf_reset(skb);
1503 
1504 	if (unlikely(!is_skb_forwardable(dev, skb))) {
1505 		atomic_long_inc(&dev->rx_dropped);
1506 		kfree_skb(skb);
1507 		return NET_RX_DROP;
1508 	}
1509 	skb_set_dev(skb, dev);
1510 	skb->tstamp.tv64 = 0;
1511 	skb->pkt_type = PACKET_HOST;
1512 	skb->protocol = eth_type_trans(skb, dev);
1513 	return netif_rx(skb);
1514 }
1515 EXPORT_SYMBOL_GPL(dev_forward_skb);
1516 
1517 static inline int deliver_skb(struct sk_buff *skb,
1518 			      struct packet_type *pt_prev,
1519 			      struct net_device *orig_dev)
1520 {
1521 	atomic_inc(&skb->users);
1522 	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
1523 }
1524 
1525 /*
1526  *	Support routine. Sends outgoing frames to any network
1527  *	taps currently in use.
1528  */
1529 
1530 static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
1531 {
1532 	struct packet_type *ptype;
1533 	struct sk_buff *skb2 = NULL;
1534 	struct packet_type *pt_prev = NULL;
1535 
1536 	rcu_read_lock();
1537 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
1538 		/* Never send packets back to the socket
1539 		 * they originated from - MvS ([email protected])
1540 		 */
1541 		if ((ptype->dev == dev || !ptype->dev) &&
1542 		    (ptype->af_packet_priv == NULL ||
1543 		     (struct sock *)ptype->af_packet_priv != skb->sk)) {
1544 			if (pt_prev) {
1545 				deliver_skb(skb2, pt_prev, skb->dev);
1546 				pt_prev = ptype;
1547 				continue;
1548 			}
1549 
1550 			skb2 = skb_clone(skb, GFP_ATOMIC);
1551 			if (!skb2)
1552 				break;
1553 
1554 			net_timestamp_set(skb2);
1555 
1556 			/* skb->nh should be correctly
1557 			   set by sender, so that the second statement is
1558 			   just protection against buggy protocols.
1559 			 */
1560 			skb_reset_mac_header(skb2);
1561 
1562 			if (skb_network_header(skb2) < skb2->data ||
1563 			    skb2->network_header > skb2->tail) {
1564 				if (net_ratelimit())
1565 					printk(KERN_CRIT "protocol %04x is "
1566 					       "buggy, dev %s\n",
1567 					       ntohs(skb2->protocol),
1568 					       dev->name);
1569 				skb_reset_network_header(skb2);
1570 			}
1571 
1572 			skb2->transport_header = skb2->network_header;
1573 			skb2->pkt_type = PACKET_OUTGOING;
1574 			pt_prev = ptype;
1575 		}
1576 	}
1577 	if (pt_prev)
1578 		pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
1579 	rcu_read_unlock();
1580 }
1581 
1582 /* netif_setup_tc - Handle tc mappings on real_num_tx_queues change
1583  * @dev: Network device
1584  * @txq: number of queues available
1585  *
1586  * If real_num_tx_queues is changed the tc mappings may no longer be
1587  * valid. To resolve this verify the tc mapping remains valid and if
1588  * not NULL the mapping. With no priorities mapping to this
1589  * offset/count pair it will no longer be used. In the worst case TC0
1590  * is invalid nothing can be done so disable priority mappings. If is
1591  * expected that drivers will fix this mapping if they can before
1592  * calling netif_set_real_num_tx_queues.
1593  */
1594 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
1595 {
1596 	int i;
1597 	struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
1598 
1599 	/* If TC0 is invalidated disable TC mapping */
1600 	if (tc->offset + tc->count > txq) {
1601 		pr_warning("Number of in use tx queues changed "
1602 			   "invalidating tc mappings. Priority "
1603 			   "traffic classification disabled!\n");
1604 		dev->num_tc = 0;
1605 		return;
1606 	}
1607 
1608 	/* Invalidated prio to tc mappings set to TC0 */
1609 	for (i = 1; i < TC_BITMASK + 1; i++) {
1610 		int q = netdev_get_prio_tc_map(dev, i);
1611 
1612 		tc = &dev->tc_to_txq[q];
1613 		if (tc->offset + tc->count > txq) {
1614 			pr_warning("Number of in use tx queues "
1615 				   "changed. Priority %i to tc "
1616 				   "mapping %i is no longer valid "
1617 				   "setting map to 0\n",
1618 				   i, q);
1619 			netdev_set_prio_tc_map(dev, i, 0);
1620 		}
1621 	}
1622 }
1623 
1624 /*
1625  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
1626  * greater then real_num_tx_queues stale skbs on the qdisc must be flushed.
1627  */
1628 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
1629 {
1630 	int rc;
1631 
1632 	if (txq < 1 || txq > dev->num_tx_queues)
1633 		return -EINVAL;
1634 
1635 	if (dev->reg_state == NETREG_REGISTERED ||
1636 	    dev->reg_state == NETREG_UNREGISTERING) {
1637 		ASSERT_RTNL();
1638 
1639 		rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
1640 						  txq);
1641 		if (rc)
1642 			return rc;
1643 
1644 		if (dev->num_tc)
1645 			netif_setup_tc(dev, txq);
1646 
1647 		if (txq < dev->real_num_tx_queues)
1648 			qdisc_reset_all_tx_gt(dev, txq);
1649 	}
1650 
1651 	dev->real_num_tx_queues = txq;
1652 	return 0;
1653 }
1654 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
1655 
1656 #ifdef CONFIG_RPS
1657 /**
1658  *	netif_set_real_num_rx_queues - set actual number of RX queues used
1659  *	@dev: Network device
1660  *	@rxq: Actual number of RX queues
1661  *
1662  *	This must be called either with the rtnl_lock held or before
1663  *	registration of the net device.  Returns 0 on success, or a
1664  *	negative error code.  If called before registration, it always
1665  *	succeeds.
1666  */
1667 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
1668 {
1669 	int rc;
1670 
1671 	if (rxq < 1 || rxq > dev->num_rx_queues)
1672 		return -EINVAL;
1673 
1674 	if (dev->reg_state == NETREG_REGISTERED) {
1675 		ASSERT_RTNL();
1676 
1677 		rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
1678 						  rxq);
1679 		if (rc)
1680 			return rc;
1681 	}
1682 
1683 	dev->real_num_rx_queues = rxq;
1684 	return 0;
1685 }
1686 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
1687 #endif
1688 
1689 static inline void __netif_reschedule(struct Qdisc *q)
1690 {
1691 	struct softnet_data *sd;
1692 	unsigned long flags;
1693 
1694 	local_irq_save(flags);
1695 	sd = &__get_cpu_var(softnet_data);
1696 	q->next_sched = NULL;
1697 	*sd->output_queue_tailp = q;
1698 	sd->output_queue_tailp = &q->next_sched;
1699 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
1700 	local_irq_restore(flags);
1701 }
1702 
1703 void __netif_schedule(struct Qdisc *q)
1704 {
1705 	if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
1706 		__netif_reschedule(q);
1707 }
1708 EXPORT_SYMBOL(__netif_schedule);
1709 
1710 void dev_kfree_skb_irq(struct sk_buff *skb)
1711 {
1712 	if (atomic_dec_and_test(&skb->users)) {
1713 		struct softnet_data *sd;
1714 		unsigned long flags;
1715 
1716 		local_irq_save(flags);
1717 		sd = &__get_cpu_var(softnet_data);
1718 		skb->next = sd->completion_queue;
1719 		sd->completion_queue = skb;
1720 		raise_softirq_irqoff(NET_TX_SOFTIRQ);
1721 		local_irq_restore(flags);
1722 	}
1723 }
1724 EXPORT_SYMBOL(dev_kfree_skb_irq);
1725 
1726 void dev_kfree_skb_any(struct sk_buff *skb)
1727 {
1728 	if (in_irq() || irqs_disabled())
1729 		dev_kfree_skb_irq(skb);
1730 	else
1731 		dev_kfree_skb(skb);
1732 }
1733 EXPORT_SYMBOL(dev_kfree_skb_any);
1734 
1735 
1736 /**
1737  * netif_device_detach - mark device as removed
1738  * @dev: network device
1739  *
1740  * Mark device as removed from system and therefore no longer available.
1741  */
1742 void netif_device_detach(struct net_device *dev)
1743 {
1744 	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
1745 	    netif_running(dev)) {
1746 		netif_tx_stop_all_queues(dev);
1747 	}
1748 }
1749 EXPORT_SYMBOL(netif_device_detach);
1750 
1751 /**
1752  * netif_device_attach - mark device as attached
1753  * @dev: network device
1754  *
1755  * Mark device as attached from system and restart if needed.
1756  */
1757 void netif_device_attach(struct net_device *dev)
1758 {
1759 	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
1760 	    netif_running(dev)) {
1761 		netif_tx_wake_all_queues(dev);
1762 		__netdev_watchdog_up(dev);
1763 	}
1764 }
1765 EXPORT_SYMBOL(netif_device_attach);
1766 
1767 /**
1768  * skb_dev_set -- assign a new device to a buffer
1769  * @skb: buffer for the new device
1770  * @dev: network device
1771  *
1772  * If an skb is owned by a device already, we have to reset
1773  * all data private to the namespace a device belongs to
1774  * before assigning it a new device.
1775  */
1776 #ifdef CONFIG_NET_NS
1777 void skb_set_dev(struct sk_buff *skb, struct net_device *dev)
1778 {
1779 	skb_dst_drop(skb);
1780 	if (skb->dev && !net_eq(dev_net(skb->dev), dev_net(dev))) {
1781 		secpath_reset(skb);
1782 		nf_reset(skb);
1783 		skb_init_secmark(skb);
1784 		skb->mark = 0;
1785 		skb->priority = 0;
1786 		skb->nf_trace = 0;
1787 		skb->ipvs_property = 0;
1788 #ifdef CONFIG_NET_SCHED
1789 		skb->tc_index = 0;
1790 #endif
1791 	}
1792 	skb->dev = dev;
1793 }
1794 EXPORT_SYMBOL(skb_set_dev);
1795 #endif /* CONFIG_NET_NS */
1796 
1797 /*
1798  * Invalidate hardware checksum when packet is to be mangled, and
1799  * complete checksum manually on outgoing path.
1800  */
1801 int skb_checksum_help(struct sk_buff *skb)
1802 {
1803 	__wsum csum;
1804 	int ret = 0, offset;
1805 
1806 	if (skb->ip_summed == CHECKSUM_COMPLETE)
1807 		goto out_set_summed;
1808 
1809 	if (unlikely(skb_shinfo(skb)->gso_size)) {
1810 		/* Let GSO fix up the checksum. */
1811 		goto out_set_summed;
1812 	}
1813 
1814 	offset = skb_checksum_start_offset(skb);
1815 	BUG_ON(offset >= skb_headlen(skb));
1816 	csum = skb_checksum(skb, offset, skb->len - offset, 0);
1817 
1818 	offset += skb->csum_offset;
1819 	BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
1820 
1821 	if (skb_cloned(skb) &&
1822 	    !skb_clone_writable(skb, offset + sizeof(__sum16))) {
1823 		ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
1824 		if (ret)
1825 			goto out;
1826 	}
1827 
1828 	*(__sum16 *)(skb->data + offset) = csum_fold(csum);
1829 out_set_summed:
1830 	skb->ip_summed = CHECKSUM_NONE;
1831 out:
1832 	return ret;
1833 }
1834 EXPORT_SYMBOL(skb_checksum_help);
1835 
1836 /**
1837  *	skb_gso_segment - Perform segmentation on skb.
1838  *	@skb: buffer to segment
1839  *	@features: features for the output path (see dev->features)
1840  *
1841  *	This function segments the given skb and returns a list of segments.
1842  *
1843  *	It may return NULL if the skb requires no segmentation.  This is
1844  *	only possible when GSO is used for verifying header integrity.
1845  */
1846 struct sk_buff *skb_gso_segment(struct sk_buff *skb, u32 features)
1847 {
1848 	struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
1849 	struct packet_type *ptype;
1850 	__be16 type = skb->protocol;
1851 	int vlan_depth = ETH_HLEN;
1852 	int err;
1853 
1854 	while (type == htons(ETH_P_8021Q)) {
1855 		struct vlan_hdr *vh;
1856 
1857 		if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
1858 			return ERR_PTR(-EINVAL);
1859 
1860 		vh = (struct vlan_hdr *)(skb->data + vlan_depth);
1861 		type = vh->h_vlan_encapsulated_proto;
1862 		vlan_depth += VLAN_HLEN;
1863 	}
1864 
1865 	skb_reset_mac_header(skb);
1866 	skb->mac_len = skb->network_header - skb->mac_header;
1867 	__skb_pull(skb, skb->mac_len);
1868 
1869 	if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
1870 		struct net_device *dev = skb->dev;
1871 		struct ethtool_drvinfo info = {};
1872 
1873 		if (dev && dev->ethtool_ops && dev->ethtool_ops->get_drvinfo)
1874 			dev->ethtool_ops->get_drvinfo(dev, &info);
1875 
1876 		WARN(1, "%s: caps=(0x%lx, 0x%lx) len=%d data_len=%d ip_summed=%d\n",
1877 		     info.driver, dev ? dev->features : 0L,
1878 		     skb->sk ? skb->sk->sk_route_caps : 0L,
1879 		     skb->len, skb->data_len, skb->ip_summed);
1880 
1881 		if (skb_header_cloned(skb) &&
1882 		    (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
1883 			return ERR_PTR(err);
1884 	}
1885 
1886 	rcu_read_lock();
1887 	list_for_each_entry_rcu(ptype,
1888 			&ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
1889 		if (ptype->type == type && !ptype->dev && ptype->gso_segment) {
1890 			if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
1891 				err = ptype->gso_send_check(skb);
1892 				segs = ERR_PTR(err);
1893 				if (err || skb_gso_ok(skb, features))
1894 					break;
1895 				__skb_push(skb, (skb->data -
1896 						 skb_network_header(skb)));
1897 			}
1898 			segs = ptype->gso_segment(skb, features);
1899 			break;
1900 		}
1901 	}
1902 	rcu_read_unlock();
1903 
1904 	__skb_push(skb, skb->data - skb_mac_header(skb));
1905 
1906 	return segs;
1907 }
1908 EXPORT_SYMBOL(skb_gso_segment);
1909 
1910 /* Take action when hardware reception checksum errors are detected. */
1911 #ifdef CONFIG_BUG
1912 void netdev_rx_csum_fault(struct net_device *dev)
1913 {
1914 	if (net_ratelimit()) {
1915 		printk(KERN_ERR "%s: hw csum failure.\n",
1916 			dev ? dev->name : "<unknown>");
1917 		dump_stack();
1918 	}
1919 }
1920 EXPORT_SYMBOL(netdev_rx_csum_fault);
1921 #endif
1922 
1923 /* Actually, we should eliminate this check as soon as we know, that:
1924  * 1. IOMMU is present and allows to map all the memory.
1925  * 2. No high memory really exists on this machine.
1926  */
1927 
1928 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
1929 {
1930 #ifdef CONFIG_HIGHMEM
1931 	int i;
1932 	if (!(dev->features & NETIF_F_HIGHDMA)) {
1933 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
1934 			if (PageHighMem(skb_shinfo(skb)->frags[i].page))
1935 				return 1;
1936 	}
1937 
1938 	if (PCI_DMA_BUS_IS_PHYS) {
1939 		struct device *pdev = dev->dev.parent;
1940 
1941 		if (!pdev)
1942 			return 0;
1943 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1944 			dma_addr_t addr = page_to_phys(skb_shinfo(skb)->frags[i].page);
1945 			if (!pdev->dma_mask || addr + PAGE_SIZE - 1 > *pdev->dma_mask)
1946 				return 1;
1947 		}
1948 	}
1949 #endif
1950 	return 0;
1951 }
1952 
1953 struct dev_gso_cb {
1954 	void (*destructor)(struct sk_buff *skb);
1955 };
1956 
1957 #define DEV_GSO_CB(skb) ((struct dev_gso_cb *)(skb)->cb)
1958 
1959 static void dev_gso_skb_destructor(struct sk_buff *skb)
1960 {
1961 	struct dev_gso_cb *cb;
1962 
1963 	do {
1964 		struct sk_buff *nskb = skb->next;
1965 
1966 		skb->next = nskb->next;
1967 		nskb->next = NULL;
1968 		kfree_skb(nskb);
1969 	} while (skb->next);
1970 
1971 	cb = DEV_GSO_CB(skb);
1972 	if (cb->destructor)
1973 		cb->destructor(skb);
1974 }
1975 
1976 /**
1977  *	dev_gso_segment - Perform emulated hardware segmentation on skb.
1978  *	@skb: buffer to segment
1979  *	@features: device features as applicable to this skb
1980  *
1981  *	This function segments the given skb and stores the list of segments
1982  *	in skb->next.
1983  */
1984 static int dev_gso_segment(struct sk_buff *skb, int features)
1985 {
1986 	struct sk_buff *segs;
1987 
1988 	segs = skb_gso_segment(skb, features);
1989 
1990 	/* Verifying header integrity only. */
1991 	if (!segs)
1992 		return 0;
1993 
1994 	if (IS_ERR(segs))
1995 		return PTR_ERR(segs);
1996 
1997 	skb->next = segs;
1998 	DEV_GSO_CB(skb)->destructor = skb->destructor;
1999 	skb->destructor = dev_gso_skb_destructor;
2000 
2001 	return 0;
2002 }
2003 
2004 /*
2005  * Try to orphan skb early, right before transmission by the device.
2006  * We cannot orphan skb if tx timestamp is requested or the sk-reference
2007  * is needed on driver level for other reasons, e.g. see net/can/raw.c
2008  */
2009 static inline void skb_orphan_try(struct sk_buff *skb)
2010 {
2011 	struct sock *sk = skb->sk;
2012 
2013 	if (sk && !skb_shinfo(skb)->tx_flags) {
2014 		/* skb_tx_hash() wont be able to get sk.
2015 		 * We copy sk_hash into skb->rxhash
2016 		 */
2017 		if (!skb->rxhash)
2018 			skb->rxhash = sk->sk_hash;
2019 		skb_orphan(skb);
2020 	}
2021 }
2022 
2023 static bool can_checksum_protocol(unsigned long features, __be16 protocol)
2024 {
2025 	return ((features & NETIF_F_GEN_CSUM) ||
2026 		((features & NETIF_F_V4_CSUM) &&
2027 		 protocol == htons(ETH_P_IP)) ||
2028 		((features & NETIF_F_V6_CSUM) &&
2029 		 protocol == htons(ETH_P_IPV6)) ||
2030 		((features & NETIF_F_FCOE_CRC) &&
2031 		 protocol == htons(ETH_P_FCOE)));
2032 }
2033 
2034 static u32 harmonize_features(struct sk_buff *skb, __be16 protocol, u32 features)
2035 {
2036 	if (!can_checksum_protocol(features, protocol)) {
2037 		features &= ~NETIF_F_ALL_CSUM;
2038 		features &= ~NETIF_F_SG;
2039 	} else if (illegal_highdma(skb->dev, skb)) {
2040 		features &= ~NETIF_F_SG;
2041 	}
2042 
2043 	return features;
2044 }
2045 
2046 u32 netif_skb_features(struct sk_buff *skb)
2047 {
2048 	__be16 protocol = skb->protocol;
2049 	u32 features = skb->dev->features;
2050 
2051 	if (protocol == htons(ETH_P_8021Q)) {
2052 		struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
2053 		protocol = veh->h_vlan_encapsulated_proto;
2054 	} else if (!vlan_tx_tag_present(skb)) {
2055 		return harmonize_features(skb, protocol, features);
2056 	}
2057 
2058 	features &= (skb->dev->vlan_features | NETIF_F_HW_VLAN_TX);
2059 
2060 	if (protocol != htons(ETH_P_8021Q)) {
2061 		return harmonize_features(skb, protocol, features);
2062 	} else {
2063 		features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
2064 				NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_TX;
2065 		return harmonize_features(skb, protocol, features);
2066 	}
2067 }
2068 EXPORT_SYMBOL(netif_skb_features);
2069 
2070 /*
2071  * Returns true if either:
2072  *	1. skb has frag_list and the device doesn't support FRAGLIST, or
2073  *	2. skb is fragmented and the device does not support SG, or if
2074  *	   at least one of fragments is in highmem and device does not
2075  *	   support DMA from it.
2076  */
2077 static inline int skb_needs_linearize(struct sk_buff *skb,
2078 				      int features)
2079 {
2080 	return skb_is_nonlinear(skb) &&
2081 			((skb_has_frag_list(skb) &&
2082 				!(features & NETIF_F_FRAGLIST)) ||
2083 			(skb_shinfo(skb)->nr_frags &&
2084 				!(features & NETIF_F_SG)));
2085 }
2086 
2087 int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
2088 			struct netdev_queue *txq)
2089 {
2090 	const struct net_device_ops *ops = dev->netdev_ops;
2091 	int rc = NETDEV_TX_OK;
2092 
2093 	if (likely(!skb->next)) {
2094 		u32 features;
2095 
2096 		/*
2097 		 * If device doesn't need skb->dst, release it right now while
2098 		 * its hot in this cpu cache
2099 		 */
2100 		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
2101 			skb_dst_drop(skb);
2102 
2103 		if (!list_empty(&ptype_all))
2104 			dev_queue_xmit_nit(skb, dev);
2105 
2106 		skb_orphan_try(skb);
2107 
2108 		features = netif_skb_features(skb);
2109 
2110 		if (vlan_tx_tag_present(skb) &&
2111 		    !(features & NETIF_F_HW_VLAN_TX)) {
2112 			skb = __vlan_put_tag(skb, vlan_tx_tag_get(skb));
2113 			if (unlikely(!skb))
2114 				goto out;
2115 
2116 			skb->vlan_tci = 0;
2117 		}
2118 
2119 		if (netif_needs_gso(skb, features)) {
2120 			if (unlikely(dev_gso_segment(skb, features)))
2121 				goto out_kfree_skb;
2122 			if (skb->next)
2123 				goto gso;
2124 		} else {
2125 			if (skb_needs_linearize(skb, features) &&
2126 			    __skb_linearize(skb))
2127 				goto out_kfree_skb;
2128 
2129 			/* If packet is not checksummed and device does not
2130 			 * support checksumming for this protocol, complete
2131 			 * checksumming here.
2132 			 */
2133 			if (skb->ip_summed == CHECKSUM_PARTIAL) {
2134 				skb_set_transport_header(skb,
2135 					skb_checksum_start_offset(skb));
2136 				if (!(features & NETIF_F_ALL_CSUM) &&
2137 				     skb_checksum_help(skb))
2138 					goto out_kfree_skb;
2139 			}
2140 		}
2141 
2142 		rc = ops->ndo_start_xmit(skb, dev);
2143 		trace_net_dev_xmit(skb, rc);
2144 		if (rc == NETDEV_TX_OK)
2145 			txq_trans_update(txq);
2146 		return rc;
2147 	}
2148 
2149 gso:
2150 	do {
2151 		struct sk_buff *nskb = skb->next;
2152 
2153 		skb->next = nskb->next;
2154 		nskb->next = NULL;
2155 
2156 		/*
2157 		 * If device doesn't need nskb->dst, release it right now while
2158 		 * its hot in this cpu cache
2159 		 */
2160 		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
2161 			skb_dst_drop(nskb);
2162 
2163 		rc = ops->ndo_start_xmit(nskb, dev);
2164 		trace_net_dev_xmit(nskb, rc);
2165 		if (unlikely(rc != NETDEV_TX_OK)) {
2166 			if (rc & ~NETDEV_TX_MASK)
2167 				goto out_kfree_gso_skb;
2168 			nskb->next = skb->next;
2169 			skb->next = nskb;
2170 			return rc;
2171 		}
2172 		txq_trans_update(txq);
2173 		if (unlikely(netif_tx_queue_stopped(txq) && skb->next))
2174 			return NETDEV_TX_BUSY;
2175 	} while (skb->next);
2176 
2177 out_kfree_gso_skb:
2178 	if (likely(skb->next == NULL))
2179 		skb->destructor = DEV_GSO_CB(skb)->destructor;
2180 out_kfree_skb:
2181 	kfree_skb(skb);
2182 out:
2183 	return rc;
2184 }
2185 
2186 static u32 hashrnd __read_mostly;
2187 
2188 /*
2189  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
2190  * to be used as a distribution range.
2191  */
2192 u16 __skb_tx_hash(const struct net_device *dev, const struct sk_buff *skb,
2193 		  unsigned int num_tx_queues)
2194 {
2195 	u32 hash;
2196 	u16 qoffset = 0;
2197 	u16 qcount = num_tx_queues;
2198 
2199 	if (skb_rx_queue_recorded(skb)) {
2200 		hash = skb_get_rx_queue(skb);
2201 		while (unlikely(hash >= num_tx_queues))
2202 			hash -= num_tx_queues;
2203 		return hash;
2204 	}
2205 
2206 	if (dev->num_tc) {
2207 		u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
2208 		qoffset = dev->tc_to_txq[tc].offset;
2209 		qcount = dev->tc_to_txq[tc].count;
2210 	}
2211 
2212 	if (skb->sk && skb->sk->sk_hash)
2213 		hash = skb->sk->sk_hash;
2214 	else
2215 		hash = (__force u16) skb->protocol ^ skb->rxhash;
2216 	hash = jhash_1word(hash, hashrnd);
2217 
2218 	return (u16) (((u64) hash * qcount) >> 32) + qoffset;
2219 }
2220 EXPORT_SYMBOL(__skb_tx_hash);
2221 
2222 static inline u16 dev_cap_txqueue(struct net_device *dev, u16 queue_index)
2223 {
2224 	if (unlikely(queue_index >= dev->real_num_tx_queues)) {
2225 		if (net_ratelimit()) {
2226 			pr_warning("%s selects TX queue %d, but "
2227 				"real number of TX queues is %d\n",
2228 				dev->name, queue_index, dev->real_num_tx_queues);
2229 		}
2230 		return 0;
2231 	}
2232 	return queue_index;
2233 }
2234 
2235 static inline int get_xps_queue(struct net_device *dev, struct sk_buff *skb)
2236 {
2237 #ifdef CONFIG_XPS
2238 	struct xps_dev_maps *dev_maps;
2239 	struct xps_map *map;
2240 	int queue_index = -1;
2241 
2242 	rcu_read_lock();
2243 	dev_maps = rcu_dereference(dev->xps_maps);
2244 	if (dev_maps) {
2245 		map = rcu_dereference(
2246 		    dev_maps->cpu_map[raw_smp_processor_id()]);
2247 		if (map) {
2248 			if (map->len == 1)
2249 				queue_index = map->queues[0];
2250 			else {
2251 				u32 hash;
2252 				if (skb->sk && skb->sk->sk_hash)
2253 					hash = skb->sk->sk_hash;
2254 				else
2255 					hash = (__force u16) skb->protocol ^
2256 					    skb->rxhash;
2257 				hash = jhash_1word(hash, hashrnd);
2258 				queue_index = map->queues[
2259 				    ((u64)hash * map->len) >> 32];
2260 			}
2261 			if (unlikely(queue_index >= dev->real_num_tx_queues))
2262 				queue_index = -1;
2263 		}
2264 	}
2265 	rcu_read_unlock();
2266 
2267 	return queue_index;
2268 #else
2269 	return -1;
2270 #endif
2271 }
2272 
2273 static struct netdev_queue *dev_pick_tx(struct net_device *dev,
2274 					struct sk_buff *skb)
2275 {
2276 	int queue_index;
2277 	const struct net_device_ops *ops = dev->netdev_ops;
2278 
2279 	if (dev->real_num_tx_queues == 1)
2280 		queue_index = 0;
2281 	else if (ops->ndo_select_queue) {
2282 		queue_index = ops->ndo_select_queue(dev, skb);
2283 		queue_index = dev_cap_txqueue(dev, queue_index);
2284 	} else {
2285 		struct sock *sk = skb->sk;
2286 		queue_index = sk_tx_queue_get(sk);
2287 
2288 		if (queue_index < 0 || skb->ooo_okay ||
2289 		    queue_index >= dev->real_num_tx_queues) {
2290 			int old_index = queue_index;
2291 
2292 			queue_index = get_xps_queue(dev, skb);
2293 			if (queue_index < 0)
2294 				queue_index = skb_tx_hash(dev, skb);
2295 
2296 			if (queue_index != old_index && sk) {
2297 				struct dst_entry *dst =
2298 				    rcu_dereference_check(sk->sk_dst_cache, 1);
2299 
2300 				if (dst && skb_dst(skb) == dst)
2301 					sk_tx_queue_set(sk, queue_index);
2302 			}
2303 		}
2304 	}
2305 
2306 	skb_set_queue_mapping(skb, queue_index);
2307 	return netdev_get_tx_queue(dev, queue_index);
2308 }
2309 
2310 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
2311 				 struct net_device *dev,
2312 				 struct netdev_queue *txq)
2313 {
2314 	spinlock_t *root_lock = qdisc_lock(q);
2315 	bool contended;
2316 	int rc;
2317 
2318 	qdisc_skb_cb(skb)->pkt_len = skb->len;
2319 	qdisc_calculate_pkt_len(skb, q);
2320 	/*
2321 	 * Heuristic to force contended enqueues to serialize on a
2322 	 * separate lock before trying to get qdisc main lock.
2323 	 * This permits __QDISC_STATE_RUNNING owner to get the lock more often
2324 	 * and dequeue packets faster.
2325 	 */
2326 	contended = qdisc_is_running(q);
2327 	if (unlikely(contended))
2328 		spin_lock(&q->busylock);
2329 
2330 	spin_lock(root_lock);
2331 	if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
2332 		kfree_skb(skb);
2333 		rc = NET_XMIT_DROP;
2334 	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
2335 		   qdisc_run_begin(q)) {
2336 		/*
2337 		 * This is a work-conserving queue; there are no old skbs
2338 		 * waiting to be sent out; and the qdisc is not running -
2339 		 * xmit the skb directly.
2340 		 */
2341 		if (!(dev->priv_flags & IFF_XMIT_DST_RELEASE))
2342 			skb_dst_force(skb);
2343 
2344 		qdisc_bstats_update(q, skb);
2345 
2346 		if (sch_direct_xmit(skb, q, dev, txq, root_lock)) {
2347 			if (unlikely(contended)) {
2348 				spin_unlock(&q->busylock);
2349 				contended = false;
2350 			}
2351 			__qdisc_run(q);
2352 		} else
2353 			qdisc_run_end(q);
2354 
2355 		rc = NET_XMIT_SUCCESS;
2356 	} else {
2357 		skb_dst_force(skb);
2358 		rc = q->enqueue(skb, q) & NET_XMIT_MASK;
2359 		if (qdisc_run_begin(q)) {
2360 			if (unlikely(contended)) {
2361 				spin_unlock(&q->busylock);
2362 				contended = false;
2363 			}
2364 			__qdisc_run(q);
2365 		}
2366 	}
2367 	spin_unlock(root_lock);
2368 	if (unlikely(contended))
2369 		spin_unlock(&q->busylock);
2370 	return rc;
2371 }
2372 
2373 static DEFINE_PER_CPU(int, xmit_recursion);
2374 #define RECURSION_LIMIT 10
2375 
2376 /**
2377  *	dev_queue_xmit - transmit a buffer
2378  *	@skb: buffer to transmit
2379  *
2380  *	Queue a buffer for transmission to a network device. The caller must
2381  *	have set the device and priority and built the buffer before calling
2382  *	this function. The function can be called from an interrupt.
2383  *
2384  *	A negative errno code is returned on a failure. A success does not
2385  *	guarantee the frame will be transmitted as it may be dropped due
2386  *	to congestion or traffic shaping.
2387  *
2388  * -----------------------------------------------------------------------------------
2389  *      I notice this method can also return errors from the queue disciplines,
2390  *      including NET_XMIT_DROP, which is a positive value.  So, errors can also
2391  *      be positive.
2392  *
2393  *      Regardless of the return value, the skb is consumed, so it is currently
2394  *      difficult to retry a send to this method.  (You can bump the ref count
2395  *      before sending to hold a reference for retry if you are careful.)
2396  *
2397  *      When calling this method, interrupts MUST be enabled.  This is because
2398  *      the BH enable code must have IRQs enabled so that it will not deadlock.
2399  *          --BLG
2400  */
2401 int dev_queue_xmit(struct sk_buff *skb)
2402 {
2403 	struct net_device *dev = skb->dev;
2404 	struct netdev_queue *txq;
2405 	struct Qdisc *q;
2406 	int rc = -ENOMEM;
2407 
2408 	/* Disable soft irqs for various locks below. Also
2409 	 * stops preemption for RCU.
2410 	 */
2411 	rcu_read_lock_bh();
2412 
2413 	txq = dev_pick_tx(dev, skb);
2414 	q = rcu_dereference_bh(txq->qdisc);
2415 
2416 #ifdef CONFIG_NET_CLS_ACT
2417 	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_EGRESS);
2418 #endif
2419 	trace_net_dev_queue(skb);
2420 	if (q->enqueue) {
2421 		rc = __dev_xmit_skb(skb, q, dev, txq);
2422 		goto out;
2423 	}
2424 
2425 	/* The device has no queue. Common case for software devices:
2426 	   loopback, all the sorts of tunnels...
2427 
2428 	   Really, it is unlikely that netif_tx_lock protection is necessary
2429 	   here.  (f.e. loopback and IP tunnels are clean ignoring statistics
2430 	   counters.)
2431 	   However, it is possible, that they rely on protection
2432 	   made by us here.
2433 
2434 	   Check this and shot the lock. It is not prone from deadlocks.
2435 	   Either shot noqueue qdisc, it is even simpler 8)
2436 	 */
2437 	if (dev->flags & IFF_UP) {
2438 		int cpu = smp_processor_id(); /* ok because BHs are off */
2439 
2440 		if (txq->xmit_lock_owner != cpu) {
2441 
2442 			if (__this_cpu_read(xmit_recursion) > RECURSION_LIMIT)
2443 				goto recursion_alert;
2444 
2445 			HARD_TX_LOCK(dev, txq, cpu);
2446 
2447 			if (!netif_tx_queue_stopped(txq)) {
2448 				__this_cpu_inc(xmit_recursion);
2449 				rc = dev_hard_start_xmit(skb, dev, txq);
2450 				__this_cpu_dec(xmit_recursion);
2451 				if (dev_xmit_complete(rc)) {
2452 					HARD_TX_UNLOCK(dev, txq);
2453 					goto out;
2454 				}
2455 			}
2456 			HARD_TX_UNLOCK(dev, txq);
2457 			if (net_ratelimit())
2458 				printk(KERN_CRIT "Virtual device %s asks to "
2459 				       "queue packet!\n", dev->name);
2460 		} else {
2461 			/* Recursion is detected! It is possible,
2462 			 * unfortunately
2463 			 */
2464 recursion_alert:
2465 			if (net_ratelimit())
2466 				printk(KERN_CRIT "Dead loop on virtual device "
2467 				       "%s, fix it urgently!\n", dev->name);
2468 		}
2469 	}
2470 
2471 	rc = -ENETDOWN;
2472 	rcu_read_unlock_bh();
2473 
2474 	kfree_skb(skb);
2475 	return rc;
2476 out:
2477 	rcu_read_unlock_bh();
2478 	return rc;
2479 }
2480 EXPORT_SYMBOL(dev_queue_xmit);
2481 
2482 
2483 /*=======================================================================
2484 			Receiver routines
2485   =======================================================================*/
2486 
2487 int netdev_max_backlog __read_mostly = 1000;
2488 int netdev_tstamp_prequeue __read_mostly = 1;
2489 int netdev_budget __read_mostly = 300;
2490 int weight_p __read_mostly = 64;            /* old backlog weight */
2491 
2492 /* Called with irq disabled */
2493 static inline void ____napi_schedule(struct softnet_data *sd,
2494 				     struct napi_struct *napi)
2495 {
2496 	list_add_tail(&napi->poll_list, &sd->poll_list);
2497 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
2498 }
2499 
2500 /*
2501  * __skb_get_rxhash: calculate a flow hash based on src/dst addresses
2502  * and src/dst port numbers. Returns a non-zero hash number on success
2503  * and 0 on failure.
2504  */
2505 __u32 __skb_get_rxhash(struct sk_buff *skb)
2506 {
2507 	int nhoff, hash = 0, poff;
2508 	const struct ipv6hdr *ip6;
2509 	const struct iphdr *ip;
2510 	u8 ip_proto;
2511 	u32 addr1, addr2, ihl;
2512 	union {
2513 		u32 v32;
2514 		u16 v16[2];
2515 	} ports;
2516 
2517 	nhoff = skb_network_offset(skb);
2518 
2519 	switch (skb->protocol) {
2520 	case __constant_htons(ETH_P_IP):
2521 		if (!pskb_may_pull(skb, sizeof(*ip) + nhoff))
2522 			goto done;
2523 
2524 		ip = (const struct iphdr *) (skb->data + nhoff);
2525 		if (ip->frag_off & htons(IP_MF | IP_OFFSET))
2526 			ip_proto = 0;
2527 		else
2528 			ip_proto = ip->protocol;
2529 		addr1 = (__force u32) ip->saddr;
2530 		addr2 = (__force u32) ip->daddr;
2531 		ihl = ip->ihl;
2532 		break;
2533 	case __constant_htons(ETH_P_IPV6):
2534 		if (!pskb_may_pull(skb, sizeof(*ip6) + nhoff))
2535 			goto done;
2536 
2537 		ip6 = (const struct ipv6hdr *) (skb->data + nhoff);
2538 		ip_proto = ip6->nexthdr;
2539 		addr1 = (__force u32) ip6->saddr.s6_addr32[3];
2540 		addr2 = (__force u32) ip6->daddr.s6_addr32[3];
2541 		ihl = (40 >> 2);
2542 		break;
2543 	default:
2544 		goto done;
2545 	}
2546 
2547 	ports.v32 = 0;
2548 	poff = proto_ports_offset(ip_proto);
2549 	if (poff >= 0) {
2550 		nhoff += ihl * 4 + poff;
2551 		if (pskb_may_pull(skb, nhoff + 4)) {
2552 			ports.v32 = * (__force u32 *) (skb->data + nhoff);
2553 			if (ports.v16[1] < ports.v16[0])
2554 				swap(ports.v16[0], ports.v16[1]);
2555 		}
2556 	}
2557 
2558 	/* get a consistent hash (same value on both flow directions) */
2559 	if (addr2 < addr1)
2560 		swap(addr1, addr2);
2561 
2562 	hash = jhash_3words(addr1, addr2, ports.v32, hashrnd);
2563 	if (!hash)
2564 		hash = 1;
2565 
2566 done:
2567 	return hash;
2568 }
2569 EXPORT_SYMBOL(__skb_get_rxhash);
2570 
2571 #ifdef CONFIG_RPS
2572 
2573 /* One global table that all flow-based protocols share. */
2574 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
2575 EXPORT_SYMBOL(rps_sock_flow_table);
2576 
2577 static struct rps_dev_flow *
2578 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
2579 	    struct rps_dev_flow *rflow, u16 next_cpu)
2580 {
2581 	u16 tcpu;
2582 
2583 	tcpu = rflow->cpu = next_cpu;
2584 	if (tcpu != RPS_NO_CPU) {
2585 #ifdef CONFIG_RFS_ACCEL
2586 		struct netdev_rx_queue *rxqueue;
2587 		struct rps_dev_flow_table *flow_table;
2588 		struct rps_dev_flow *old_rflow;
2589 		u32 flow_id;
2590 		u16 rxq_index;
2591 		int rc;
2592 
2593 		/* Should we steer this flow to a different hardware queue? */
2594 		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
2595 		    !(dev->features & NETIF_F_NTUPLE))
2596 			goto out;
2597 		rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
2598 		if (rxq_index == skb_get_rx_queue(skb))
2599 			goto out;
2600 
2601 		rxqueue = dev->_rx + rxq_index;
2602 		flow_table = rcu_dereference(rxqueue->rps_flow_table);
2603 		if (!flow_table)
2604 			goto out;
2605 		flow_id = skb->rxhash & flow_table->mask;
2606 		rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
2607 							rxq_index, flow_id);
2608 		if (rc < 0)
2609 			goto out;
2610 		old_rflow = rflow;
2611 		rflow = &flow_table->flows[flow_id];
2612 		rflow->cpu = next_cpu;
2613 		rflow->filter = rc;
2614 		if (old_rflow->filter == rflow->filter)
2615 			old_rflow->filter = RPS_NO_FILTER;
2616 	out:
2617 #endif
2618 		rflow->last_qtail =
2619 			per_cpu(softnet_data, tcpu).input_queue_head;
2620 	}
2621 
2622 	return rflow;
2623 }
2624 
2625 /*
2626  * get_rps_cpu is called from netif_receive_skb and returns the target
2627  * CPU from the RPS map of the receiving queue for a given skb.
2628  * rcu_read_lock must be held on entry.
2629  */
2630 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
2631 		       struct rps_dev_flow **rflowp)
2632 {
2633 	struct netdev_rx_queue *rxqueue;
2634 	struct rps_map *map;
2635 	struct rps_dev_flow_table *flow_table;
2636 	struct rps_sock_flow_table *sock_flow_table;
2637 	int cpu = -1;
2638 	u16 tcpu;
2639 
2640 	if (skb_rx_queue_recorded(skb)) {
2641 		u16 index = skb_get_rx_queue(skb);
2642 		if (unlikely(index >= dev->real_num_rx_queues)) {
2643 			WARN_ONCE(dev->real_num_rx_queues > 1,
2644 				  "%s received packet on queue %u, but number "
2645 				  "of RX queues is %u\n",
2646 				  dev->name, index, dev->real_num_rx_queues);
2647 			goto done;
2648 		}
2649 		rxqueue = dev->_rx + index;
2650 	} else
2651 		rxqueue = dev->_rx;
2652 
2653 	map = rcu_dereference(rxqueue->rps_map);
2654 	if (map) {
2655 		if (map->len == 1 &&
2656 		    !rcu_dereference_raw(rxqueue->rps_flow_table)) {
2657 			tcpu = map->cpus[0];
2658 			if (cpu_online(tcpu))
2659 				cpu = tcpu;
2660 			goto done;
2661 		}
2662 	} else if (!rcu_dereference_raw(rxqueue->rps_flow_table)) {
2663 		goto done;
2664 	}
2665 
2666 	skb_reset_network_header(skb);
2667 	if (!skb_get_rxhash(skb))
2668 		goto done;
2669 
2670 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
2671 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
2672 	if (flow_table && sock_flow_table) {
2673 		u16 next_cpu;
2674 		struct rps_dev_flow *rflow;
2675 
2676 		rflow = &flow_table->flows[skb->rxhash & flow_table->mask];
2677 		tcpu = rflow->cpu;
2678 
2679 		next_cpu = sock_flow_table->ents[skb->rxhash &
2680 		    sock_flow_table->mask];
2681 
2682 		/*
2683 		 * If the desired CPU (where last recvmsg was done) is
2684 		 * different from current CPU (one in the rx-queue flow
2685 		 * table entry), switch if one of the following holds:
2686 		 *   - Current CPU is unset (equal to RPS_NO_CPU).
2687 		 *   - Current CPU is offline.
2688 		 *   - The current CPU's queue tail has advanced beyond the
2689 		 *     last packet that was enqueued using this table entry.
2690 		 *     This guarantees that all previous packets for the flow
2691 		 *     have been dequeued, thus preserving in order delivery.
2692 		 */
2693 		if (unlikely(tcpu != next_cpu) &&
2694 		    (tcpu == RPS_NO_CPU || !cpu_online(tcpu) ||
2695 		     ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
2696 		      rflow->last_qtail)) >= 0))
2697 			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
2698 
2699 		if (tcpu != RPS_NO_CPU && cpu_online(tcpu)) {
2700 			*rflowp = rflow;
2701 			cpu = tcpu;
2702 			goto done;
2703 		}
2704 	}
2705 
2706 	if (map) {
2707 		tcpu = map->cpus[((u64) skb->rxhash * map->len) >> 32];
2708 
2709 		if (cpu_online(tcpu)) {
2710 			cpu = tcpu;
2711 			goto done;
2712 		}
2713 	}
2714 
2715 done:
2716 	return cpu;
2717 }
2718 
2719 #ifdef CONFIG_RFS_ACCEL
2720 
2721 /**
2722  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
2723  * @dev: Device on which the filter was set
2724  * @rxq_index: RX queue index
2725  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
2726  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
2727  *
2728  * Drivers that implement ndo_rx_flow_steer() should periodically call
2729  * this function for each installed filter and remove the filters for
2730  * which it returns %true.
2731  */
2732 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
2733 			 u32 flow_id, u16 filter_id)
2734 {
2735 	struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
2736 	struct rps_dev_flow_table *flow_table;
2737 	struct rps_dev_flow *rflow;
2738 	bool expire = true;
2739 	int cpu;
2740 
2741 	rcu_read_lock();
2742 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
2743 	if (flow_table && flow_id <= flow_table->mask) {
2744 		rflow = &flow_table->flows[flow_id];
2745 		cpu = ACCESS_ONCE(rflow->cpu);
2746 		if (rflow->filter == filter_id && cpu != RPS_NO_CPU &&
2747 		    ((int)(per_cpu(softnet_data, cpu).input_queue_head -
2748 			   rflow->last_qtail) <
2749 		     (int)(10 * flow_table->mask)))
2750 			expire = false;
2751 	}
2752 	rcu_read_unlock();
2753 	return expire;
2754 }
2755 EXPORT_SYMBOL(rps_may_expire_flow);
2756 
2757 #endif /* CONFIG_RFS_ACCEL */
2758 
2759 /* Called from hardirq (IPI) context */
2760 static void rps_trigger_softirq(void *data)
2761 {
2762 	struct softnet_data *sd = data;
2763 
2764 	____napi_schedule(sd, &sd->backlog);
2765 	sd->received_rps++;
2766 }
2767 
2768 #endif /* CONFIG_RPS */
2769 
2770 /*
2771  * Check if this softnet_data structure is another cpu one
2772  * If yes, queue it to our IPI list and return 1
2773  * If no, return 0
2774  */
2775 static int rps_ipi_queued(struct softnet_data *sd)
2776 {
2777 #ifdef CONFIG_RPS
2778 	struct softnet_data *mysd = &__get_cpu_var(softnet_data);
2779 
2780 	if (sd != mysd) {
2781 		sd->rps_ipi_next = mysd->rps_ipi_list;
2782 		mysd->rps_ipi_list = sd;
2783 
2784 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
2785 		return 1;
2786 	}
2787 #endif /* CONFIG_RPS */
2788 	return 0;
2789 }
2790 
2791 /*
2792  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
2793  * queue (may be a remote CPU queue).
2794  */
2795 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
2796 			      unsigned int *qtail)
2797 {
2798 	struct softnet_data *sd;
2799 	unsigned long flags;
2800 
2801 	sd = &per_cpu(softnet_data, cpu);
2802 
2803 	local_irq_save(flags);
2804 
2805 	rps_lock(sd);
2806 	if (skb_queue_len(&sd->input_pkt_queue) <= netdev_max_backlog) {
2807 		if (skb_queue_len(&sd->input_pkt_queue)) {
2808 enqueue:
2809 			__skb_queue_tail(&sd->input_pkt_queue, skb);
2810 			input_queue_tail_incr_save(sd, qtail);
2811 			rps_unlock(sd);
2812 			local_irq_restore(flags);
2813 			return NET_RX_SUCCESS;
2814 		}
2815 
2816 		/* Schedule NAPI for backlog device
2817 		 * We can use non atomic operation since we own the queue lock
2818 		 */
2819 		if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state)) {
2820 			if (!rps_ipi_queued(sd))
2821 				____napi_schedule(sd, &sd->backlog);
2822 		}
2823 		goto enqueue;
2824 	}
2825 
2826 	sd->dropped++;
2827 	rps_unlock(sd);
2828 
2829 	local_irq_restore(flags);
2830 
2831 	atomic_long_inc(&skb->dev->rx_dropped);
2832 	kfree_skb(skb);
2833 	return NET_RX_DROP;
2834 }
2835 
2836 /**
2837  *	netif_rx	-	post buffer to the network code
2838  *	@skb: buffer to post
2839  *
2840  *	This function receives a packet from a device driver and queues it for
2841  *	the upper (protocol) levels to process.  It always succeeds. The buffer
2842  *	may be dropped during processing for congestion control or by the
2843  *	protocol layers.
2844  *
2845  *	return values:
2846  *	NET_RX_SUCCESS	(no congestion)
2847  *	NET_RX_DROP     (packet was dropped)
2848  *
2849  */
2850 
2851 int netif_rx(struct sk_buff *skb)
2852 {
2853 	int ret;
2854 
2855 	/* if netpoll wants it, pretend we never saw it */
2856 	if (netpoll_rx(skb))
2857 		return NET_RX_DROP;
2858 
2859 	if (netdev_tstamp_prequeue)
2860 		net_timestamp_check(skb);
2861 
2862 	trace_netif_rx(skb);
2863 #ifdef CONFIG_RPS
2864 	{
2865 		struct rps_dev_flow voidflow, *rflow = &voidflow;
2866 		int cpu;
2867 
2868 		preempt_disable();
2869 		rcu_read_lock();
2870 
2871 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
2872 		if (cpu < 0)
2873 			cpu = smp_processor_id();
2874 
2875 		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
2876 
2877 		rcu_read_unlock();
2878 		preempt_enable();
2879 	}
2880 #else
2881 	{
2882 		unsigned int qtail;
2883 		ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
2884 		put_cpu();
2885 	}
2886 #endif
2887 	return ret;
2888 }
2889 EXPORT_SYMBOL(netif_rx);
2890 
2891 int netif_rx_ni(struct sk_buff *skb)
2892 {
2893 	int err;
2894 
2895 	preempt_disable();
2896 	err = netif_rx(skb);
2897 	if (local_softirq_pending())
2898 		do_softirq();
2899 	preempt_enable();
2900 
2901 	return err;
2902 }
2903 EXPORT_SYMBOL(netif_rx_ni);
2904 
2905 static void net_tx_action(struct softirq_action *h)
2906 {
2907 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
2908 
2909 	if (sd->completion_queue) {
2910 		struct sk_buff *clist;
2911 
2912 		local_irq_disable();
2913 		clist = sd->completion_queue;
2914 		sd->completion_queue = NULL;
2915 		local_irq_enable();
2916 
2917 		while (clist) {
2918 			struct sk_buff *skb = clist;
2919 			clist = clist->next;
2920 
2921 			WARN_ON(atomic_read(&skb->users));
2922 			trace_kfree_skb(skb, net_tx_action);
2923 			__kfree_skb(skb);
2924 		}
2925 	}
2926 
2927 	if (sd->output_queue) {
2928 		struct Qdisc *head;
2929 
2930 		local_irq_disable();
2931 		head = sd->output_queue;
2932 		sd->output_queue = NULL;
2933 		sd->output_queue_tailp = &sd->output_queue;
2934 		local_irq_enable();
2935 
2936 		while (head) {
2937 			struct Qdisc *q = head;
2938 			spinlock_t *root_lock;
2939 
2940 			head = head->next_sched;
2941 
2942 			root_lock = qdisc_lock(q);
2943 			if (spin_trylock(root_lock)) {
2944 				smp_mb__before_clear_bit();
2945 				clear_bit(__QDISC_STATE_SCHED,
2946 					  &q->state);
2947 				qdisc_run(q);
2948 				spin_unlock(root_lock);
2949 			} else {
2950 				if (!test_bit(__QDISC_STATE_DEACTIVATED,
2951 					      &q->state)) {
2952 					__netif_reschedule(q);
2953 				} else {
2954 					smp_mb__before_clear_bit();
2955 					clear_bit(__QDISC_STATE_SCHED,
2956 						  &q->state);
2957 				}
2958 			}
2959 		}
2960 	}
2961 }
2962 
2963 #if (defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)) && \
2964     (defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE))
2965 /* This hook is defined here for ATM LANE */
2966 int (*br_fdb_test_addr_hook)(struct net_device *dev,
2967 			     unsigned char *addr) __read_mostly;
2968 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
2969 #endif
2970 
2971 #ifdef CONFIG_NET_CLS_ACT
2972 /* TODO: Maybe we should just force sch_ingress to be compiled in
2973  * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
2974  * a compare and 2 stores extra right now if we dont have it on
2975  * but have CONFIG_NET_CLS_ACT
2976  * NOTE: This doesn't stop any functionality; if you dont have
2977  * the ingress scheduler, you just can't add policies on ingress.
2978  *
2979  */
2980 static int ing_filter(struct sk_buff *skb, struct netdev_queue *rxq)
2981 {
2982 	struct net_device *dev = skb->dev;
2983 	u32 ttl = G_TC_RTTL(skb->tc_verd);
2984 	int result = TC_ACT_OK;
2985 	struct Qdisc *q;
2986 
2987 	if (unlikely(MAX_RED_LOOP < ttl++)) {
2988 		if (net_ratelimit())
2989 			pr_warning( "Redir loop detected Dropping packet (%d->%d)\n",
2990 			       skb->skb_iif, dev->ifindex);
2991 		return TC_ACT_SHOT;
2992 	}
2993 
2994 	skb->tc_verd = SET_TC_RTTL(skb->tc_verd, ttl);
2995 	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS);
2996 
2997 	q = rxq->qdisc;
2998 	if (q != &noop_qdisc) {
2999 		spin_lock(qdisc_lock(q));
3000 		if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))
3001 			result = qdisc_enqueue_root(skb, q);
3002 		spin_unlock(qdisc_lock(q));
3003 	}
3004 
3005 	return result;
3006 }
3007 
3008 static inline struct sk_buff *handle_ing(struct sk_buff *skb,
3009 					 struct packet_type **pt_prev,
3010 					 int *ret, struct net_device *orig_dev)
3011 {
3012 	struct netdev_queue *rxq = rcu_dereference(skb->dev->ingress_queue);
3013 
3014 	if (!rxq || rxq->qdisc == &noop_qdisc)
3015 		goto out;
3016 
3017 	if (*pt_prev) {
3018 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
3019 		*pt_prev = NULL;
3020 	}
3021 
3022 	switch (ing_filter(skb, rxq)) {
3023 	case TC_ACT_SHOT:
3024 	case TC_ACT_STOLEN:
3025 		kfree_skb(skb);
3026 		return NULL;
3027 	}
3028 
3029 out:
3030 	skb->tc_verd = 0;
3031 	return skb;
3032 }
3033 #endif
3034 
3035 /**
3036  *	netdev_rx_handler_register - register receive handler
3037  *	@dev: device to register a handler for
3038  *	@rx_handler: receive handler to register
3039  *	@rx_handler_data: data pointer that is used by rx handler
3040  *
3041  *	Register a receive hander for a device. This handler will then be
3042  *	called from __netif_receive_skb. A negative errno code is returned
3043  *	on a failure.
3044  *
3045  *	The caller must hold the rtnl_mutex.
3046  *
3047  *	For a general description of rx_handler, see enum rx_handler_result.
3048  */
3049 int netdev_rx_handler_register(struct net_device *dev,
3050 			       rx_handler_func_t *rx_handler,
3051 			       void *rx_handler_data)
3052 {
3053 	ASSERT_RTNL();
3054 
3055 	if (dev->rx_handler)
3056 		return -EBUSY;
3057 
3058 	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
3059 	rcu_assign_pointer(dev->rx_handler, rx_handler);
3060 
3061 	return 0;
3062 }
3063 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
3064 
3065 /**
3066  *	netdev_rx_handler_unregister - unregister receive handler
3067  *	@dev: device to unregister a handler from
3068  *
3069  *	Unregister a receive hander from a device.
3070  *
3071  *	The caller must hold the rtnl_mutex.
3072  */
3073 void netdev_rx_handler_unregister(struct net_device *dev)
3074 {
3075 
3076 	ASSERT_RTNL();
3077 	rcu_assign_pointer(dev->rx_handler, NULL);
3078 	rcu_assign_pointer(dev->rx_handler_data, NULL);
3079 }
3080 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
3081 
3082 static int __netif_receive_skb(struct sk_buff *skb)
3083 {
3084 	struct packet_type *ptype, *pt_prev;
3085 	rx_handler_func_t *rx_handler;
3086 	struct net_device *orig_dev;
3087 	struct net_device *null_or_dev;
3088 	bool deliver_exact = false;
3089 	int ret = NET_RX_DROP;
3090 	__be16 type;
3091 
3092 	if (!netdev_tstamp_prequeue)
3093 		net_timestamp_check(skb);
3094 
3095 	trace_netif_receive_skb(skb);
3096 
3097 	/* if we've gotten here through NAPI, check netpoll */
3098 	if (netpoll_receive_skb(skb))
3099 		return NET_RX_DROP;
3100 
3101 	if (!skb->skb_iif)
3102 		skb->skb_iif = skb->dev->ifindex;
3103 	orig_dev = skb->dev;
3104 
3105 	skb_reset_network_header(skb);
3106 	skb_reset_transport_header(skb);
3107 	skb->mac_len = skb->network_header - skb->mac_header;
3108 
3109 	pt_prev = NULL;
3110 
3111 	rcu_read_lock();
3112 
3113 another_round:
3114 
3115 	__this_cpu_inc(softnet_data.processed);
3116 
3117 	if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) {
3118 		skb = vlan_untag(skb);
3119 		if (unlikely(!skb))
3120 			goto out;
3121 	}
3122 
3123 #ifdef CONFIG_NET_CLS_ACT
3124 	if (skb->tc_verd & TC_NCLS) {
3125 		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
3126 		goto ncls;
3127 	}
3128 #endif
3129 
3130 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
3131 		if (!ptype->dev || ptype->dev == skb->dev) {
3132 			if (pt_prev)
3133 				ret = deliver_skb(skb, pt_prev, orig_dev);
3134 			pt_prev = ptype;
3135 		}
3136 	}
3137 
3138 #ifdef CONFIG_NET_CLS_ACT
3139 	skb = handle_ing(skb, &pt_prev, &ret, orig_dev);
3140 	if (!skb)
3141 		goto out;
3142 ncls:
3143 #endif
3144 
3145 	rx_handler = rcu_dereference(skb->dev->rx_handler);
3146 	if (rx_handler) {
3147 		if (pt_prev) {
3148 			ret = deliver_skb(skb, pt_prev, orig_dev);
3149 			pt_prev = NULL;
3150 		}
3151 		switch (rx_handler(&skb)) {
3152 		case RX_HANDLER_CONSUMED:
3153 			goto out;
3154 		case RX_HANDLER_ANOTHER:
3155 			goto another_round;
3156 		case RX_HANDLER_EXACT:
3157 			deliver_exact = true;
3158 		case RX_HANDLER_PASS:
3159 			break;
3160 		default:
3161 			BUG();
3162 		}
3163 	}
3164 
3165 	if (vlan_tx_tag_present(skb)) {
3166 		if (pt_prev) {
3167 			ret = deliver_skb(skb, pt_prev, orig_dev);
3168 			pt_prev = NULL;
3169 		}
3170 		if (vlan_do_receive(&skb)) {
3171 			ret = __netif_receive_skb(skb);
3172 			goto out;
3173 		} else if (unlikely(!skb))
3174 			goto out;
3175 	}
3176 
3177 	/* deliver only exact match when indicated */
3178 	null_or_dev = deliver_exact ? skb->dev : NULL;
3179 
3180 	type = skb->protocol;
3181 	list_for_each_entry_rcu(ptype,
3182 			&ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
3183 		if (ptype->type == type &&
3184 		    (ptype->dev == null_or_dev || ptype->dev == skb->dev ||
3185 		     ptype->dev == orig_dev)) {
3186 			if (pt_prev)
3187 				ret = deliver_skb(skb, pt_prev, orig_dev);
3188 			pt_prev = ptype;
3189 		}
3190 	}
3191 
3192 	if (pt_prev) {
3193 		ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
3194 	} else {
3195 		atomic_long_inc(&skb->dev->rx_dropped);
3196 		kfree_skb(skb);
3197 		/* Jamal, now you will not able to escape explaining
3198 		 * me how you were going to use this. :-)
3199 		 */
3200 		ret = NET_RX_DROP;
3201 	}
3202 
3203 out:
3204 	rcu_read_unlock();
3205 	return ret;
3206 }
3207 
3208 /**
3209  *	netif_receive_skb - process receive buffer from network
3210  *	@skb: buffer to process
3211  *
3212  *	netif_receive_skb() is the main receive data processing function.
3213  *	It always succeeds. The buffer may be dropped during processing
3214  *	for congestion control or by the protocol layers.
3215  *
3216  *	This function may only be called from softirq context and interrupts
3217  *	should be enabled.
3218  *
3219  *	Return values (usually ignored):
3220  *	NET_RX_SUCCESS: no congestion
3221  *	NET_RX_DROP: packet was dropped
3222  */
3223 int netif_receive_skb(struct sk_buff *skb)
3224 {
3225 	if (netdev_tstamp_prequeue)
3226 		net_timestamp_check(skb);
3227 
3228 	if (skb_defer_rx_timestamp(skb))
3229 		return NET_RX_SUCCESS;
3230 
3231 #ifdef CONFIG_RPS
3232 	{
3233 		struct rps_dev_flow voidflow, *rflow = &voidflow;
3234 		int cpu, ret;
3235 
3236 		rcu_read_lock();
3237 
3238 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
3239 
3240 		if (cpu >= 0) {
3241 			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
3242 			rcu_read_unlock();
3243 		} else {
3244 			rcu_read_unlock();
3245 			ret = __netif_receive_skb(skb);
3246 		}
3247 
3248 		return ret;
3249 	}
3250 #else
3251 	return __netif_receive_skb(skb);
3252 #endif
3253 }
3254 EXPORT_SYMBOL(netif_receive_skb);
3255 
3256 /* Network device is going away, flush any packets still pending
3257  * Called with irqs disabled.
3258  */
3259 static void flush_backlog(void *arg)
3260 {
3261 	struct net_device *dev = arg;
3262 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
3263 	struct sk_buff *skb, *tmp;
3264 
3265 	rps_lock(sd);
3266 	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
3267 		if (skb->dev == dev) {
3268 			__skb_unlink(skb, &sd->input_pkt_queue);
3269 			kfree_skb(skb);
3270 			input_queue_head_incr(sd);
3271 		}
3272 	}
3273 	rps_unlock(sd);
3274 
3275 	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
3276 		if (skb->dev == dev) {
3277 			__skb_unlink(skb, &sd->process_queue);
3278 			kfree_skb(skb);
3279 			input_queue_head_incr(sd);
3280 		}
3281 	}
3282 }
3283 
3284 static int napi_gro_complete(struct sk_buff *skb)
3285 {
3286 	struct packet_type *ptype;
3287 	__be16 type = skb->protocol;
3288 	struct list_head *head = &ptype_base[ntohs(type) & PTYPE_HASH_MASK];
3289 	int err = -ENOENT;
3290 
3291 	if (NAPI_GRO_CB(skb)->count == 1) {
3292 		skb_shinfo(skb)->gso_size = 0;
3293 		goto out;
3294 	}
3295 
3296 	rcu_read_lock();
3297 	list_for_each_entry_rcu(ptype, head, list) {
3298 		if (ptype->type != type || ptype->dev || !ptype->gro_complete)
3299 			continue;
3300 
3301 		err = ptype->gro_complete(skb);
3302 		break;
3303 	}
3304 	rcu_read_unlock();
3305 
3306 	if (err) {
3307 		WARN_ON(&ptype->list == head);
3308 		kfree_skb(skb);
3309 		return NET_RX_SUCCESS;
3310 	}
3311 
3312 out:
3313 	return netif_receive_skb(skb);
3314 }
3315 
3316 inline void napi_gro_flush(struct napi_struct *napi)
3317 {
3318 	struct sk_buff *skb, *next;
3319 
3320 	for (skb = napi->gro_list; skb; skb = next) {
3321 		next = skb->next;
3322 		skb->next = NULL;
3323 		napi_gro_complete(skb);
3324 	}
3325 
3326 	napi->gro_count = 0;
3327 	napi->gro_list = NULL;
3328 }
3329 EXPORT_SYMBOL(napi_gro_flush);
3330 
3331 enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3332 {
3333 	struct sk_buff **pp = NULL;
3334 	struct packet_type *ptype;
3335 	__be16 type = skb->protocol;
3336 	struct list_head *head = &ptype_base[ntohs(type) & PTYPE_HASH_MASK];
3337 	int same_flow;
3338 	int mac_len;
3339 	enum gro_result ret;
3340 
3341 	if (!(skb->dev->features & NETIF_F_GRO) || netpoll_rx_on(skb))
3342 		goto normal;
3343 
3344 	if (skb_is_gso(skb) || skb_has_frag_list(skb))
3345 		goto normal;
3346 
3347 	rcu_read_lock();
3348 	list_for_each_entry_rcu(ptype, head, list) {
3349 		if (ptype->type != type || ptype->dev || !ptype->gro_receive)
3350 			continue;
3351 
3352 		skb_set_network_header(skb, skb_gro_offset(skb));
3353 		mac_len = skb->network_header - skb->mac_header;
3354 		skb->mac_len = mac_len;
3355 		NAPI_GRO_CB(skb)->same_flow = 0;
3356 		NAPI_GRO_CB(skb)->flush = 0;
3357 		NAPI_GRO_CB(skb)->free = 0;
3358 
3359 		pp = ptype->gro_receive(&napi->gro_list, skb);
3360 		break;
3361 	}
3362 	rcu_read_unlock();
3363 
3364 	if (&ptype->list == head)
3365 		goto normal;
3366 
3367 	same_flow = NAPI_GRO_CB(skb)->same_flow;
3368 	ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
3369 
3370 	if (pp) {
3371 		struct sk_buff *nskb = *pp;
3372 
3373 		*pp = nskb->next;
3374 		nskb->next = NULL;
3375 		napi_gro_complete(nskb);
3376 		napi->gro_count--;
3377 	}
3378 
3379 	if (same_flow)
3380 		goto ok;
3381 
3382 	if (NAPI_GRO_CB(skb)->flush || napi->gro_count >= MAX_GRO_SKBS)
3383 		goto normal;
3384 
3385 	napi->gro_count++;
3386 	NAPI_GRO_CB(skb)->count = 1;
3387 	skb_shinfo(skb)->gso_size = skb_gro_len(skb);
3388 	skb->next = napi->gro_list;
3389 	napi->gro_list = skb;
3390 	ret = GRO_HELD;
3391 
3392 pull:
3393 	if (skb_headlen(skb) < skb_gro_offset(skb)) {
3394 		int grow = skb_gro_offset(skb) - skb_headlen(skb);
3395 
3396 		BUG_ON(skb->end - skb->tail < grow);
3397 
3398 		memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
3399 
3400 		skb->tail += grow;
3401 		skb->data_len -= grow;
3402 
3403 		skb_shinfo(skb)->frags[0].page_offset += grow;
3404 		skb_shinfo(skb)->frags[0].size -= grow;
3405 
3406 		if (unlikely(!skb_shinfo(skb)->frags[0].size)) {
3407 			put_page(skb_shinfo(skb)->frags[0].page);
3408 			memmove(skb_shinfo(skb)->frags,
3409 				skb_shinfo(skb)->frags + 1,
3410 				--skb_shinfo(skb)->nr_frags * sizeof(skb_frag_t));
3411 		}
3412 	}
3413 
3414 ok:
3415 	return ret;
3416 
3417 normal:
3418 	ret = GRO_NORMAL;
3419 	goto pull;
3420 }
3421 EXPORT_SYMBOL(dev_gro_receive);
3422 
3423 static inline gro_result_t
3424 __napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3425 {
3426 	struct sk_buff *p;
3427 
3428 	for (p = napi->gro_list; p; p = p->next) {
3429 		unsigned long diffs;
3430 
3431 		diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
3432 		diffs |= p->vlan_tci ^ skb->vlan_tci;
3433 		diffs |= compare_ether_header(skb_mac_header(p),
3434 					      skb_gro_mac_header(skb));
3435 		NAPI_GRO_CB(p)->same_flow = !diffs;
3436 		NAPI_GRO_CB(p)->flush = 0;
3437 	}
3438 
3439 	return dev_gro_receive(napi, skb);
3440 }
3441 
3442 gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
3443 {
3444 	switch (ret) {
3445 	case GRO_NORMAL:
3446 		if (netif_receive_skb(skb))
3447 			ret = GRO_DROP;
3448 		break;
3449 
3450 	case GRO_DROP:
3451 	case GRO_MERGED_FREE:
3452 		kfree_skb(skb);
3453 		break;
3454 
3455 	case GRO_HELD:
3456 	case GRO_MERGED:
3457 		break;
3458 	}
3459 
3460 	return ret;
3461 }
3462 EXPORT_SYMBOL(napi_skb_finish);
3463 
3464 void skb_gro_reset_offset(struct sk_buff *skb)
3465 {
3466 	NAPI_GRO_CB(skb)->data_offset = 0;
3467 	NAPI_GRO_CB(skb)->frag0 = NULL;
3468 	NAPI_GRO_CB(skb)->frag0_len = 0;
3469 
3470 	if (skb->mac_header == skb->tail &&
3471 	    !PageHighMem(skb_shinfo(skb)->frags[0].page)) {
3472 		NAPI_GRO_CB(skb)->frag0 =
3473 			page_address(skb_shinfo(skb)->frags[0].page) +
3474 			skb_shinfo(skb)->frags[0].page_offset;
3475 		NAPI_GRO_CB(skb)->frag0_len = skb_shinfo(skb)->frags[0].size;
3476 	}
3477 }
3478 EXPORT_SYMBOL(skb_gro_reset_offset);
3479 
3480 gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3481 {
3482 	skb_gro_reset_offset(skb);
3483 
3484 	return napi_skb_finish(__napi_gro_receive(napi, skb), skb);
3485 }
3486 EXPORT_SYMBOL(napi_gro_receive);
3487 
3488 static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
3489 {
3490 	__skb_pull(skb, skb_headlen(skb));
3491 	skb_reserve(skb, NET_IP_ALIGN - skb_headroom(skb));
3492 	skb->vlan_tci = 0;
3493 	skb->dev = napi->dev;
3494 	skb->skb_iif = 0;
3495 
3496 	napi->skb = skb;
3497 }
3498 
3499 struct sk_buff *napi_get_frags(struct napi_struct *napi)
3500 {
3501 	struct sk_buff *skb = napi->skb;
3502 
3503 	if (!skb) {
3504 		skb = netdev_alloc_skb_ip_align(napi->dev, GRO_MAX_HEAD);
3505 		if (skb)
3506 			napi->skb = skb;
3507 	}
3508 	return skb;
3509 }
3510 EXPORT_SYMBOL(napi_get_frags);
3511 
3512 gro_result_t napi_frags_finish(struct napi_struct *napi, struct sk_buff *skb,
3513 			       gro_result_t ret)
3514 {
3515 	switch (ret) {
3516 	case GRO_NORMAL:
3517 	case GRO_HELD:
3518 		skb->protocol = eth_type_trans(skb, skb->dev);
3519 
3520 		if (ret == GRO_HELD)
3521 			skb_gro_pull(skb, -ETH_HLEN);
3522 		else if (netif_receive_skb(skb))
3523 			ret = GRO_DROP;
3524 		break;
3525 
3526 	case GRO_DROP:
3527 	case GRO_MERGED_FREE:
3528 		napi_reuse_skb(napi, skb);
3529 		break;
3530 
3531 	case GRO_MERGED:
3532 		break;
3533 	}
3534 
3535 	return ret;
3536 }
3537 EXPORT_SYMBOL(napi_frags_finish);
3538 
3539 struct sk_buff *napi_frags_skb(struct napi_struct *napi)
3540 {
3541 	struct sk_buff *skb = napi->skb;
3542 	struct ethhdr *eth;
3543 	unsigned int hlen;
3544 	unsigned int off;
3545 
3546 	napi->skb = NULL;
3547 
3548 	skb_reset_mac_header(skb);
3549 	skb_gro_reset_offset(skb);
3550 
3551 	off = skb_gro_offset(skb);
3552 	hlen = off + sizeof(*eth);
3553 	eth = skb_gro_header_fast(skb, off);
3554 	if (skb_gro_header_hard(skb, hlen)) {
3555 		eth = skb_gro_header_slow(skb, hlen, off);
3556 		if (unlikely(!eth)) {
3557 			napi_reuse_skb(napi, skb);
3558 			skb = NULL;
3559 			goto out;
3560 		}
3561 	}
3562 
3563 	skb_gro_pull(skb, sizeof(*eth));
3564 
3565 	/*
3566 	 * This works because the only protocols we care about don't require
3567 	 * special handling.  We'll fix it up properly at the end.
3568 	 */
3569 	skb->protocol = eth->h_proto;
3570 
3571 out:
3572 	return skb;
3573 }
3574 EXPORT_SYMBOL(napi_frags_skb);
3575 
3576 gro_result_t napi_gro_frags(struct napi_struct *napi)
3577 {
3578 	struct sk_buff *skb = napi_frags_skb(napi);
3579 
3580 	if (!skb)
3581 		return GRO_DROP;
3582 
3583 	return napi_frags_finish(napi, skb, __napi_gro_receive(napi, skb));
3584 }
3585 EXPORT_SYMBOL(napi_gro_frags);
3586 
3587 /*
3588  * net_rps_action sends any pending IPI's for rps.
3589  * Note: called with local irq disabled, but exits with local irq enabled.
3590  */
3591 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
3592 {
3593 #ifdef CONFIG_RPS
3594 	struct softnet_data *remsd = sd->rps_ipi_list;
3595 
3596 	if (remsd) {
3597 		sd->rps_ipi_list = NULL;
3598 
3599 		local_irq_enable();
3600 
3601 		/* Send pending IPI's to kick RPS processing on remote cpus. */
3602 		while (remsd) {
3603 			struct softnet_data *next = remsd->rps_ipi_next;
3604 
3605 			if (cpu_online(remsd->cpu))
3606 				__smp_call_function_single(remsd->cpu,
3607 							   &remsd->csd, 0);
3608 			remsd = next;
3609 		}
3610 	} else
3611 #endif
3612 		local_irq_enable();
3613 }
3614 
3615 static int process_backlog(struct napi_struct *napi, int quota)
3616 {
3617 	int work = 0;
3618 	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
3619 
3620 #ifdef CONFIG_RPS
3621 	/* Check if we have pending ipi, its better to send them now,
3622 	 * not waiting net_rx_action() end.
3623 	 */
3624 	if (sd->rps_ipi_list) {
3625 		local_irq_disable();
3626 		net_rps_action_and_irq_enable(sd);
3627 	}
3628 #endif
3629 	napi->weight = weight_p;
3630 	local_irq_disable();
3631 	while (work < quota) {
3632 		struct sk_buff *skb;
3633 		unsigned int qlen;
3634 
3635 		while ((skb = __skb_dequeue(&sd->process_queue))) {
3636 			local_irq_enable();
3637 			__netif_receive_skb(skb);
3638 			local_irq_disable();
3639 			input_queue_head_incr(sd);
3640 			if (++work >= quota) {
3641 				local_irq_enable();
3642 				return work;
3643 			}
3644 		}
3645 
3646 		rps_lock(sd);
3647 		qlen = skb_queue_len(&sd->input_pkt_queue);
3648 		if (qlen)
3649 			skb_queue_splice_tail_init(&sd->input_pkt_queue,
3650 						   &sd->process_queue);
3651 
3652 		if (qlen < quota - work) {
3653 			/*
3654 			 * Inline a custom version of __napi_complete().
3655 			 * only current cpu owns and manipulates this napi,
3656 			 * and NAPI_STATE_SCHED is the only possible flag set on backlog.
3657 			 * we can use a plain write instead of clear_bit(),
3658 			 * and we dont need an smp_mb() memory barrier.
3659 			 */
3660 			list_del(&napi->poll_list);
3661 			napi->state = 0;
3662 
3663 			quota = work + qlen;
3664 		}
3665 		rps_unlock(sd);
3666 	}
3667 	local_irq_enable();
3668 
3669 	return work;
3670 }
3671 
3672 /**
3673  * __napi_schedule - schedule for receive
3674  * @n: entry to schedule
3675  *
3676  * The entry's receive function will be scheduled to run
3677  */
3678 void __napi_schedule(struct napi_struct *n)
3679 {
3680 	unsigned long flags;
3681 
3682 	local_irq_save(flags);
3683 	____napi_schedule(&__get_cpu_var(softnet_data), n);
3684 	local_irq_restore(flags);
3685 }
3686 EXPORT_SYMBOL(__napi_schedule);
3687 
3688 void __napi_complete(struct napi_struct *n)
3689 {
3690 	BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
3691 	BUG_ON(n->gro_list);
3692 
3693 	list_del(&n->poll_list);
3694 	smp_mb__before_clear_bit();
3695 	clear_bit(NAPI_STATE_SCHED, &n->state);
3696 }
3697 EXPORT_SYMBOL(__napi_complete);
3698 
3699 void napi_complete(struct napi_struct *n)
3700 {
3701 	unsigned long flags;
3702 
3703 	/*
3704 	 * don't let napi dequeue from the cpu poll list
3705 	 * just in case its running on a different cpu
3706 	 */
3707 	if (unlikely(test_bit(NAPI_STATE_NPSVC, &n->state)))
3708 		return;
3709 
3710 	napi_gro_flush(n);
3711 	local_irq_save(flags);
3712 	__napi_complete(n);
3713 	local_irq_restore(flags);
3714 }
3715 EXPORT_SYMBOL(napi_complete);
3716 
3717 void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
3718 		    int (*poll)(struct napi_struct *, int), int weight)
3719 {
3720 	INIT_LIST_HEAD(&napi->poll_list);
3721 	napi->gro_count = 0;
3722 	napi->gro_list = NULL;
3723 	napi->skb = NULL;
3724 	napi->poll = poll;
3725 	napi->weight = weight;
3726 	list_add(&napi->dev_list, &dev->napi_list);
3727 	napi->dev = dev;
3728 #ifdef CONFIG_NETPOLL
3729 	spin_lock_init(&napi->poll_lock);
3730 	napi->poll_owner = -1;
3731 #endif
3732 	set_bit(NAPI_STATE_SCHED, &napi->state);
3733 }
3734 EXPORT_SYMBOL(netif_napi_add);
3735 
3736 void netif_napi_del(struct napi_struct *napi)
3737 {
3738 	struct sk_buff *skb, *next;
3739 
3740 	list_del_init(&napi->dev_list);
3741 	napi_free_frags(napi);
3742 
3743 	for (skb = napi->gro_list; skb; skb = next) {
3744 		next = skb->next;
3745 		skb->next = NULL;
3746 		kfree_skb(skb);
3747 	}
3748 
3749 	napi->gro_list = NULL;
3750 	napi->gro_count = 0;
3751 }
3752 EXPORT_SYMBOL(netif_napi_del);
3753 
3754 static void net_rx_action(struct softirq_action *h)
3755 {
3756 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
3757 	unsigned long time_limit = jiffies + 2;
3758 	int budget = netdev_budget;
3759 	void *have;
3760 
3761 	local_irq_disable();
3762 
3763 	while (!list_empty(&sd->poll_list)) {
3764 		struct napi_struct *n;
3765 		int work, weight;
3766 
3767 		/* If softirq window is exhuasted then punt.
3768 		 * Allow this to run for 2 jiffies since which will allow
3769 		 * an average latency of 1.5/HZ.
3770 		 */
3771 		if (unlikely(budget <= 0 || time_after(jiffies, time_limit)))
3772 			goto softnet_break;
3773 
3774 		local_irq_enable();
3775 
3776 		/* Even though interrupts have been re-enabled, this
3777 		 * access is safe because interrupts can only add new
3778 		 * entries to the tail of this list, and only ->poll()
3779 		 * calls can remove this head entry from the list.
3780 		 */
3781 		n = list_first_entry(&sd->poll_list, struct napi_struct, poll_list);
3782 
3783 		have = netpoll_poll_lock(n);
3784 
3785 		weight = n->weight;
3786 
3787 		/* This NAPI_STATE_SCHED test is for avoiding a race
3788 		 * with netpoll's poll_napi().  Only the entity which
3789 		 * obtains the lock and sees NAPI_STATE_SCHED set will
3790 		 * actually make the ->poll() call.  Therefore we avoid
3791 		 * accidentally calling ->poll() when NAPI is not scheduled.
3792 		 */
3793 		work = 0;
3794 		if (test_bit(NAPI_STATE_SCHED, &n->state)) {
3795 			work = n->poll(n, weight);
3796 			trace_napi_poll(n);
3797 		}
3798 
3799 		WARN_ON_ONCE(work > weight);
3800 
3801 		budget -= work;
3802 
3803 		local_irq_disable();
3804 
3805 		/* Drivers must not modify the NAPI state if they
3806 		 * consume the entire weight.  In such cases this code
3807 		 * still "owns" the NAPI instance and therefore can
3808 		 * move the instance around on the list at-will.
3809 		 */
3810 		if (unlikely(work == weight)) {
3811 			if (unlikely(napi_disable_pending(n))) {
3812 				local_irq_enable();
3813 				napi_complete(n);
3814 				local_irq_disable();
3815 			} else
3816 				list_move_tail(&n->poll_list, &sd->poll_list);
3817 		}
3818 
3819 		netpoll_poll_unlock(have);
3820 	}
3821 out:
3822 	net_rps_action_and_irq_enable(sd);
3823 
3824 #ifdef CONFIG_NET_DMA
3825 	/*
3826 	 * There may not be any more sk_buffs coming right now, so push
3827 	 * any pending DMA copies to hardware
3828 	 */
3829 	dma_issue_pending_all();
3830 #endif
3831 
3832 	return;
3833 
3834 softnet_break:
3835 	sd->time_squeeze++;
3836 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
3837 	goto out;
3838 }
3839 
3840 static gifconf_func_t *gifconf_list[NPROTO];
3841 
3842 /**
3843  *	register_gifconf	-	register a SIOCGIF handler
3844  *	@family: Address family
3845  *	@gifconf: Function handler
3846  *
3847  *	Register protocol dependent address dumping routines. The handler
3848  *	that is passed must not be freed or reused until it has been replaced
3849  *	by another handler.
3850  */
3851 int register_gifconf(unsigned int family, gifconf_func_t *gifconf)
3852 {
3853 	if (family >= NPROTO)
3854 		return -EINVAL;
3855 	gifconf_list[family] = gifconf;
3856 	return 0;
3857 }
3858 EXPORT_SYMBOL(register_gifconf);
3859 
3860 
3861 /*
3862  *	Map an interface index to its name (SIOCGIFNAME)
3863  */
3864 
3865 /*
3866  *	We need this ioctl for efficient implementation of the
3867  *	if_indextoname() function required by the IPv6 API.  Without
3868  *	it, we would have to search all the interfaces to find a
3869  *	match.  --pb
3870  */
3871 
3872 static int dev_ifname(struct net *net, struct ifreq __user *arg)
3873 {
3874 	struct net_device *dev;
3875 	struct ifreq ifr;
3876 
3877 	/*
3878 	 *	Fetch the caller's info block.
3879 	 */
3880 
3881 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
3882 		return -EFAULT;
3883 
3884 	rcu_read_lock();
3885 	dev = dev_get_by_index_rcu(net, ifr.ifr_ifindex);
3886 	if (!dev) {
3887 		rcu_read_unlock();
3888 		return -ENODEV;
3889 	}
3890 
3891 	strcpy(ifr.ifr_name, dev->name);
3892 	rcu_read_unlock();
3893 
3894 	if (copy_to_user(arg, &ifr, sizeof(struct ifreq)))
3895 		return -EFAULT;
3896 	return 0;
3897 }
3898 
3899 /*
3900  *	Perform a SIOCGIFCONF call. This structure will change
3901  *	size eventually, and there is nothing I can do about it.
3902  *	Thus we will need a 'compatibility mode'.
3903  */
3904 
3905 static int dev_ifconf(struct net *net, char __user *arg)
3906 {
3907 	struct ifconf ifc;
3908 	struct net_device *dev;
3909 	char __user *pos;
3910 	int len;
3911 	int total;
3912 	int i;
3913 
3914 	/*
3915 	 *	Fetch the caller's info block.
3916 	 */
3917 
3918 	if (copy_from_user(&ifc, arg, sizeof(struct ifconf)))
3919 		return -EFAULT;
3920 
3921 	pos = ifc.ifc_buf;
3922 	len = ifc.ifc_len;
3923 
3924 	/*
3925 	 *	Loop over the interfaces, and write an info block for each.
3926 	 */
3927 
3928 	total = 0;
3929 	for_each_netdev(net, dev) {
3930 		for (i = 0; i < NPROTO; i++) {
3931 			if (gifconf_list[i]) {
3932 				int done;
3933 				if (!pos)
3934 					done = gifconf_list[i](dev, NULL, 0);
3935 				else
3936 					done = gifconf_list[i](dev, pos + total,
3937 							       len - total);
3938 				if (done < 0)
3939 					return -EFAULT;
3940 				total += done;
3941 			}
3942 		}
3943 	}
3944 
3945 	/*
3946 	 *	All done.  Write the updated control block back to the caller.
3947 	 */
3948 	ifc.ifc_len = total;
3949 
3950 	/*
3951 	 * 	Both BSD and Solaris return 0 here, so we do too.
3952 	 */
3953 	return copy_to_user(arg, &ifc, sizeof(struct ifconf)) ? -EFAULT : 0;
3954 }
3955 
3956 #ifdef CONFIG_PROC_FS
3957 /*
3958  *	This is invoked by the /proc filesystem handler to display a device
3959  *	in detail.
3960  */
3961 void *dev_seq_start(struct seq_file *seq, loff_t *pos)
3962 	__acquires(RCU)
3963 {
3964 	struct net *net = seq_file_net(seq);
3965 	loff_t off;
3966 	struct net_device *dev;
3967 
3968 	rcu_read_lock();
3969 	if (!*pos)
3970 		return SEQ_START_TOKEN;
3971 
3972 	off = 1;
3973 	for_each_netdev_rcu(net, dev)
3974 		if (off++ == *pos)
3975 			return dev;
3976 
3977 	return NULL;
3978 }
3979 
3980 void *dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3981 {
3982 	struct net_device *dev = v;
3983 
3984 	if (v == SEQ_START_TOKEN)
3985 		dev = first_net_device_rcu(seq_file_net(seq));
3986 	else
3987 		dev = next_net_device_rcu(dev);
3988 
3989 	++*pos;
3990 	return dev;
3991 }
3992 
3993 void dev_seq_stop(struct seq_file *seq, void *v)
3994 	__releases(RCU)
3995 {
3996 	rcu_read_unlock();
3997 }
3998 
3999 static void dev_seq_printf_stats(struct seq_file *seq, struct net_device *dev)
4000 {
4001 	struct rtnl_link_stats64 temp;
4002 	const struct rtnl_link_stats64 *stats = dev_get_stats(dev, &temp);
4003 
4004 	seq_printf(seq, "%6s: %7llu %7llu %4llu %4llu %4llu %5llu %10llu %9llu "
4005 		   "%8llu %7llu %4llu %4llu %4llu %5llu %7llu %10llu\n",
4006 		   dev->name, stats->rx_bytes, stats->rx_packets,
4007 		   stats->rx_errors,
4008 		   stats->rx_dropped + stats->rx_missed_errors,
4009 		   stats->rx_fifo_errors,
4010 		   stats->rx_length_errors + stats->rx_over_errors +
4011 		    stats->rx_crc_errors + stats->rx_frame_errors,
4012 		   stats->rx_compressed, stats->multicast,
4013 		   stats->tx_bytes, stats->tx_packets,
4014 		   stats->tx_errors, stats->tx_dropped,
4015 		   stats->tx_fifo_errors, stats->collisions,
4016 		   stats->tx_carrier_errors +
4017 		    stats->tx_aborted_errors +
4018 		    stats->tx_window_errors +
4019 		    stats->tx_heartbeat_errors,
4020 		   stats->tx_compressed);
4021 }
4022 
4023 /*
4024  *	Called from the PROCfs module. This now uses the new arbitrary sized
4025  *	/proc/net interface to create /proc/net/dev
4026  */
4027 static int dev_seq_show(struct seq_file *seq, void *v)
4028 {
4029 	if (v == SEQ_START_TOKEN)
4030 		seq_puts(seq, "Inter-|   Receive                            "
4031 			      "                    |  Transmit\n"
4032 			      " face |bytes    packets errs drop fifo frame "
4033 			      "compressed multicast|bytes    packets errs "
4034 			      "drop fifo colls carrier compressed\n");
4035 	else
4036 		dev_seq_printf_stats(seq, v);
4037 	return 0;
4038 }
4039 
4040 static struct softnet_data *softnet_get_online(loff_t *pos)
4041 {
4042 	struct softnet_data *sd = NULL;
4043 
4044 	while (*pos < nr_cpu_ids)
4045 		if (cpu_online(*pos)) {
4046 			sd = &per_cpu(softnet_data, *pos);
4047 			break;
4048 		} else
4049 			++*pos;
4050 	return sd;
4051 }
4052 
4053 static void *softnet_seq_start(struct seq_file *seq, loff_t *pos)
4054 {
4055 	return softnet_get_online(pos);
4056 }
4057 
4058 static void *softnet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4059 {
4060 	++*pos;
4061 	return softnet_get_online(pos);
4062 }
4063 
4064 static void softnet_seq_stop(struct seq_file *seq, void *v)
4065 {
4066 }
4067 
4068 static int softnet_seq_show(struct seq_file *seq, void *v)
4069 {
4070 	struct softnet_data *sd = v;
4071 
4072 	seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x\n",
4073 		   sd->processed, sd->dropped, sd->time_squeeze, 0,
4074 		   0, 0, 0, 0, /* was fastroute */
4075 		   sd->cpu_collision, sd->received_rps);
4076 	return 0;
4077 }
4078 
4079 static const struct seq_operations dev_seq_ops = {
4080 	.start = dev_seq_start,
4081 	.next  = dev_seq_next,
4082 	.stop  = dev_seq_stop,
4083 	.show  = dev_seq_show,
4084 };
4085 
4086 static int dev_seq_open(struct inode *inode, struct file *file)
4087 {
4088 	return seq_open_net(inode, file, &dev_seq_ops,
4089 			    sizeof(struct seq_net_private));
4090 }
4091 
4092 static const struct file_operations dev_seq_fops = {
4093 	.owner	 = THIS_MODULE,
4094 	.open    = dev_seq_open,
4095 	.read    = seq_read,
4096 	.llseek  = seq_lseek,
4097 	.release = seq_release_net,
4098 };
4099 
4100 static const struct seq_operations softnet_seq_ops = {
4101 	.start = softnet_seq_start,
4102 	.next  = softnet_seq_next,
4103 	.stop  = softnet_seq_stop,
4104 	.show  = softnet_seq_show,
4105 };
4106 
4107 static int softnet_seq_open(struct inode *inode, struct file *file)
4108 {
4109 	return seq_open(file, &softnet_seq_ops);
4110 }
4111 
4112 static const struct file_operations softnet_seq_fops = {
4113 	.owner	 = THIS_MODULE,
4114 	.open    = softnet_seq_open,
4115 	.read    = seq_read,
4116 	.llseek  = seq_lseek,
4117 	.release = seq_release,
4118 };
4119 
4120 static void *ptype_get_idx(loff_t pos)
4121 {
4122 	struct packet_type *pt = NULL;
4123 	loff_t i = 0;
4124 	int t;
4125 
4126 	list_for_each_entry_rcu(pt, &ptype_all, list) {
4127 		if (i == pos)
4128 			return pt;
4129 		++i;
4130 	}
4131 
4132 	for (t = 0; t < PTYPE_HASH_SIZE; t++) {
4133 		list_for_each_entry_rcu(pt, &ptype_base[t], list) {
4134 			if (i == pos)
4135 				return pt;
4136 			++i;
4137 		}
4138 	}
4139 	return NULL;
4140 }
4141 
4142 static void *ptype_seq_start(struct seq_file *seq, loff_t *pos)
4143 	__acquires(RCU)
4144 {
4145 	rcu_read_lock();
4146 	return *pos ? ptype_get_idx(*pos - 1) : SEQ_START_TOKEN;
4147 }
4148 
4149 static void *ptype_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4150 {
4151 	struct packet_type *pt;
4152 	struct list_head *nxt;
4153 	int hash;
4154 
4155 	++*pos;
4156 	if (v == SEQ_START_TOKEN)
4157 		return ptype_get_idx(0);
4158 
4159 	pt = v;
4160 	nxt = pt->list.next;
4161 	if (pt->type == htons(ETH_P_ALL)) {
4162 		if (nxt != &ptype_all)
4163 			goto found;
4164 		hash = 0;
4165 		nxt = ptype_base[0].next;
4166 	} else
4167 		hash = ntohs(pt->type) & PTYPE_HASH_MASK;
4168 
4169 	while (nxt == &ptype_base[hash]) {
4170 		if (++hash >= PTYPE_HASH_SIZE)
4171 			return NULL;
4172 		nxt = ptype_base[hash].next;
4173 	}
4174 found:
4175 	return list_entry(nxt, struct packet_type, list);
4176 }
4177 
4178 static void ptype_seq_stop(struct seq_file *seq, void *v)
4179 	__releases(RCU)
4180 {
4181 	rcu_read_unlock();
4182 }
4183 
4184 static int ptype_seq_show(struct seq_file *seq, void *v)
4185 {
4186 	struct packet_type *pt = v;
4187 
4188 	if (v == SEQ_START_TOKEN)
4189 		seq_puts(seq, "Type Device      Function\n");
4190 	else if (pt->dev == NULL || dev_net(pt->dev) == seq_file_net(seq)) {
4191 		if (pt->type == htons(ETH_P_ALL))
4192 			seq_puts(seq, "ALL ");
4193 		else
4194 			seq_printf(seq, "%04x", ntohs(pt->type));
4195 
4196 		seq_printf(seq, " %-8s %pF\n",
4197 			   pt->dev ? pt->dev->name : "", pt->func);
4198 	}
4199 
4200 	return 0;
4201 }
4202 
4203 static const struct seq_operations ptype_seq_ops = {
4204 	.start = ptype_seq_start,
4205 	.next  = ptype_seq_next,
4206 	.stop  = ptype_seq_stop,
4207 	.show  = ptype_seq_show,
4208 };
4209 
4210 static int ptype_seq_open(struct inode *inode, struct file *file)
4211 {
4212 	return seq_open_net(inode, file, &ptype_seq_ops,
4213 			sizeof(struct seq_net_private));
4214 }
4215 
4216 static const struct file_operations ptype_seq_fops = {
4217 	.owner	 = THIS_MODULE,
4218 	.open    = ptype_seq_open,
4219 	.read    = seq_read,
4220 	.llseek  = seq_lseek,
4221 	.release = seq_release_net,
4222 };
4223 
4224 
4225 static int __net_init dev_proc_net_init(struct net *net)
4226 {
4227 	int rc = -ENOMEM;
4228 
4229 	if (!proc_net_fops_create(net, "dev", S_IRUGO, &dev_seq_fops))
4230 		goto out;
4231 	if (!proc_net_fops_create(net, "softnet_stat", S_IRUGO, &softnet_seq_fops))
4232 		goto out_dev;
4233 	if (!proc_net_fops_create(net, "ptype", S_IRUGO, &ptype_seq_fops))
4234 		goto out_softnet;
4235 
4236 	if (wext_proc_init(net))
4237 		goto out_ptype;
4238 	rc = 0;
4239 out:
4240 	return rc;
4241 out_ptype:
4242 	proc_net_remove(net, "ptype");
4243 out_softnet:
4244 	proc_net_remove(net, "softnet_stat");
4245 out_dev:
4246 	proc_net_remove(net, "dev");
4247 	goto out;
4248 }
4249 
4250 static void __net_exit dev_proc_net_exit(struct net *net)
4251 {
4252 	wext_proc_exit(net);
4253 
4254 	proc_net_remove(net, "ptype");
4255 	proc_net_remove(net, "softnet_stat");
4256 	proc_net_remove(net, "dev");
4257 }
4258 
4259 static struct pernet_operations __net_initdata dev_proc_ops = {
4260 	.init = dev_proc_net_init,
4261 	.exit = dev_proc_net_exit,
4262 };
4263 
4264 static int __init dev_proc_init(void)
4265 {
4266 	return register_pernet_subsys(&dev_proc_ops);
4267 }
4268 #else
4269 #define dev_proc_init() 0
4270 #endif	/* CONFIG_PROC_FS */
4271 
4272 
4273 /**
4274  *	netdev_set_master	-	set up master pointer
4275  *	@slave: slave device
4276  *	@master: new master device
4277  *
4278  *	Changes the master device of the slave. Pass %NULL to break the
4279  *	bonding. The caller must hold the RTNL semaphore. On a failure
4280  *	a negative errno code is returned. On success the reference counts
4281  *	are adjusted and the function returns zero.
4282  */
4283 int netdev_set_master(struct net_device *slave, struct net_device *master)
4284 {
4285 	struct net_device *old = slave->master;
4286 
4287 	ASSERT_RTNL();
4288 
4289 	if (master) {
4290 		if (old)
4291 			return -EBUSY;
4292 		dev_hold(master);
4293 	}
4294 
4295 	slave->master = master;
4296 
4297 	if (old) {
4298 		synchronize_net();
4299 		dev_put(old);
4300 	}
4301 	return 0;
4302 }
4303 EXPORT_SYMBOL(netdev_set_master);
4304 
4305 /**
4306  *	netdev_set_bond_master	-	set up bonding master/slave pair
4307  *	@slave: slave device
4308  *	@master: new master device
4309  *
4310  *	Changes the master device of the slave. Pass %NULL to break the
4311  *	bonding. The caller must hold the RTNL semaphore. On a failure
4312  *	a negative errno code is returned. On success %RTM_NEWLINK is sent
4313  *	to the routing socket and the function returns zero.
4314  */
4315 int netdev_set_bond_master(struct net_device *slave, struct net_device *master)
4316 {
4317 	int err;
4318 
4319 	ASSERT_RTNL();
4320 
4321 	err = netdev_set_master(slave, master);
4322 	if (err)
4323 		return err;
4324 	if (master)
4325 		slave->flags |= IFF_SLAVE;
4326 	else
4327 		slave->flags &= ~IFF_SLAVE;
4328 
4329 	rtmsg_ifinfo(RTM_NEWLINK, slave, IFF_SLAVE);
4330 	return 0;
4331 }
4332 EXPORT_SYMBOL(netdev_set_bond_master);
4333 
4334 static void dev_change_rx_flags(struct net_device *dev, int flags)
4335 {
4336 	const struct net_device_ops *ops = dev->netdev_ops;
4337 
4338 	if ((dev->flags & IFF_UP) && ops->ndo_change_rx_flags)
4339 		ops->ndo_change_rx_flags(dev, flags);
4340 }
4341 
4342 static int __dev_set_promiscuity(struct net_device *dev, int inc)
4343 {
4344 	unsigned short old_flags = dev->flags;
4345 	uid_t uid;
4346 	gid_t gid;
4347 
4348 	ASSERT_RTNL();
4349 
4350 	dev->flags |= IFF_PROMISC;
4351 	dev->promiscuity += inc;
4352 	if (dev->promiscuity == 0) {
4353 		/*
4354 		 * Avoid overflow.
4355 		 * If inc causes overflow, untouch promisc and return error.
4356 		 */
4357 		if (inc < 0)
4358 			dev->flags &= ~IFF_PROMISC;
4359 		else {
4360 			dev->promiscuity -= inc;
4361 			printk(KERN_WARNING "%s: promiscuity touches roof, "
4362 				"set promiscuity failed, promiscuity feature "
4363 				"of device might be broken.\n", dev->name);
4364 			return -EOVERFLOW;
4365 		}
4366 	}
4367 	if (dev->flags != old_flags) {
4368 		printk(KERN_INFO "device %s %s promiscuous mode\n",
4369 		       dev->name, (dev->flags & IFF_PROMISC) ? "entered" :
4370 							       "left");
4371 		if (audit_enabled) {
4372 			current_uid_gid(&uid, &gid);
4373 			audit_log(current->audit_context, GFP_ATOMIC,
4374 				AUDIT_ANOM_PROMISCUOUS,
4375 				"dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
4376 				dev->name, (dev->flags & IFF_PROMISC),
4377 				(old_flags & IFF_PROMISC),
4378 				audit_get_loginuid(current),
4379 				uid, gid,
4380 				audit_get_sessionid(current));
4381 		}
4382 
4383 		dev_change_rx_flags(dev, IFF_PROMISC);
4384 	}
4385 	return 0;
4386 }
4387 
4388 /**
4389  *	dev_set_promiscuity	- update promiscuity count on a device
4390  *	@dev: device
4391  *	@inc: modifier
4392  *
4393  *	Add or remove promiscuity from a device. While the count in the device
4394  *	remains above zero the interface remains promiscuous. Once it hits zero
4395  *	the device reverts back to normal filtering operation. A negative inc
4396  *	value is used to drop promiscuity on the device.
4397  *	Return 0 if successful or a negative errno code on error.
4398  */
4399 int dev_set_promiscuity(struct net_device *dev, int inc)
4400 {
4401 	unsigned short old_flags = dev->flags;
4402 	int err;
4403 
4404 	err = __dev_set_promiscuity(dev, inc);
4405 	if (err < 0)
4406 		return err;
4407 	if (dev->flags != old_flags)
4408 		dev_set_rx_mode(dev);
4409 	return err;
4410 }
4411 EXPORT_SYMBOL(dev_set_promiscuity);
4412 
4413 /**
4414  *	dev_set_allmulti	- update allmulti count on a device
4415  *	@dev: device
4416  *	@inc: modifier
4417  *
4418  *	Add or remove reception of all multicast frames to a device. While the
4419  *	count in the device remains above zero the interface remains listening
4420  *	to all interfaces. Once it hits zero the device reverts back to normal
4421  *	filtering operation. A negative @inc value is used to drop the counter
4422  *	when releasing a resource needing all multicasts.
4423  *	Return 0 if successful or a negative errno code on error.
4424  */
4425 
4426 int dev_set_allmulti(struct net_device *dev, int inc)
4427 {
4428 	unsigned short old_flags = dev->flags;
4429 
4430 	ASSERT_RTNL();
4431 
4432 	dev->flags |= IFF_ALLMULTI;
4433 	dev->allmulti += inc;
4434 	if (dev->allmulti == 0) {
4435 		/*
4436 		 * Avoid overflow.
4437 		 * If inc causes overflow, untouch allmulti and return error.
4438 		 */
4439 		if (inc < 0)
4440 			dev->flags &= ~IFF_ALLMULTI;
4441 		else {
4442 			dev->allmulti -= inc;
4443 			printk(KERN_WARNING "%s: allmulti touches roof, "
4444 				"set allmulti failed, allmulti feature of "
4445 				"device might be broken.\n", dev->name);
4446 			return -EOVERFLOW;
4447 		}
4448 	}
4449 	if (dev->flags ^ old_flags) {
4450 		dev_change_rx_flags(dev, IFF_ALLMULTI);
4451 		dev_set_rx_mode(dev);
4452 	}
4453 	return 0;
4454 }
4455 EXPORT_SYMBOL(dev_set_allmulti);
4456 
4457 /*
4458  *	Upload unicast and multicast address lists to device and
4459  *	configure RX filtering. When the device doesn't support unicast
4460  *	filtering it is put in promiscuous mode while unicast addresses
4461  *	are present.
4462  */
4463 void __dev_set_rx_mode(struct net_device *dev)
4464 {
4465 	const struct net_device_ops *ops = dev->netdev_ops;
4466 
4467 	/* dev_open will call this function so the list will stay sane. */
4468 	if (!(dev->flags&IFF_UP))
4469 		return;
4470 
4471 	if (!netif_device_present(dev))
4472 		return;
4473 
4474 	if (ops->ndo_set_rx_mode)
4475 		ops->ndo_set_rx_mode(dev);
4476 	else {
4477 		/* Unicast addresses changes may only happen under the rtnl,
4478 		 * therefore calling __dev_set_promiscuity here is safe.
4479 		 */
4480 		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
4481 			__dev_set_promiscuity(dev, 1);
4482 			dev->uc_promisc = 1;
4483 		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
4484 			__dev_set_promiscuity(dev, -1);
4485 			dev->uc_promisc = 0;
4486 		}
4487 
4488 		if (ops->ndo_set_multicast_list)
4489 			ops->ndo_set_multicast_list(dev);
4490 	}
4491 }
4492 
4493 void dev_set_rx_mode(struct net_device *dev)
4494 {
4495 	netif_addr_lock_bh(dev);
4496 	__dev_set_rx_mode(dev);
4497 	netif_addr_unlock_bh(dev);
4498 }
4499 
4500 /**
4501  *	dev_ethtool_get_settings - call device's ethtool_ops::get_settings()
4502  *	@dev: device
4503  *	@cmd: memory area for ethtool_ops::get_settings() result
4504  *
4505  *      The cmd arg is initialized properly (cleared and
4506  *      ethtool_cmd::cmd field set to ETHTOOL_GSET).
4507  *
4508  *	Return device's ethtool_ops::get_settings() result value or
4509  *	-EOPNOTSUPP when device doesn't expose
4510  *	ethtool_ops::get_settings() operation.
4511  */
4512 int dev_ethtool_get_settings(struct net_device *dev,
4513 			     struct ethtool_cmd *cmd)
4514 {
4515 	if (!dev->ethtool_ops || !dev->ethtool_ops->get_settings)
4516 		return -EOPNOTSUPP;
4517 
4518 	memset(cmd, 0, sizeof(struct ethtool_cmd));
4519 	cmd->cmd = ETHTOOL_GSET;
4520 	return dev->ethtool_ops->get_settings(dev, cmd);
4521 }
4522 EXPORT_SYMBOL(dev_ethtool_get_settings);
4523 
4524 /**
4525  *	dev_get_flags - get flags reported to userspace
4526  *	@dev: device
4527  *
4528  *	Get the combination of flag bits exported through APIs to userspace.
4529  */
4530 unsigned dev_get_flags(const struct net_device *dev)
4531 {
4532 	unsigned flags;
4533 
4534 	flags = (dev->flags & ~(IFF_PROMISC |
4535 				IFF_ALLMULTI |
4536 				IFF_RUNNING |
4537 				IFF_LOWER_UP |
4538 				IFF_DORMANT)) |
4539 		(dev->gflags & (IFF_PROMISC |
4540 				IFF_ALLMULTI));
4541 
4542 	if (netif_running(dev)) {
4543 		if (netif_oper_up(dev))
4544 			flags |= IFF_RUNNING;
4545 		if (netif_carrier_ok(dev))
4546 			flags |= IFF_LOWER_UP;
4547 		if (netif_dormant(dev))
4548 			flags |= IFF_DORMANT;
4549 	}
4550 
4551 	return flags;
4552 }
4553 EXPORT_SYMBOL(dev_get_flags);
4554 
4555 int __dev_change_flags(struct net_device *dev, unsigned int flags)
4556 {
4557 	int old_flags = dev->flags;
4558 	int ret;
4559 
4560 	ASSERT_RTNL();
4561 
4562 	/*
4563 	 *	Set the flags on our device.
4564 	 */
4565 
4566 	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
4567 			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
4568 			       IFF_AUTOMEDIA)) |
4569 		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
4570 				    IFF_ALLMULTI));
4571 
4572 	/*
4573 	 *	Load in the correct multicast list now the flags have changed.
4574 	 */
4575 
4576 	if ((old_flags ^ flags) & IFF_MULTICAST)
4577 		dev_change_rx_flags(dev, IFF_MULTICAST);
4578 
4579 	dev_set_rx_mode(dev);
4580 
4581 	/*
4582 	 *	Have we downed the interface. We handle IFF_UP ourselves
4583 	 *	according to user attempts to set it, rather than blindly
4584 	 *	setting it.
4585 	 */
4586 
4587 	ret = 0;
4588 	if ((old_flags ^ flags) & IFF_UP) {	/* Bit is different  ? */
4589 		ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev);
4590 
4591 		if (!ret)
4592 			dev_set_rx_mode(dev);
4593 	}
4594 
4595 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
4596 		int inc = (flags & IFF_PROMISC) ? 1 : -1;
4597 
4598 		dev->gflags ^= IFF_PROMISC;
4599 		dev_set_promiscuity(dev, inc);
4600 	}
4601 
4602 	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
4603 	   is important. Some (broken) drivers set IFF_PROMISC, when
4604 	   IFF_ALLMULTI is requested not asking us and not reporting.
4605 	 */
4606 	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
4607 		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
4608 
4609 		dev->gflags ^= IFF_ALLMULTI;
4610 		dev_set_allmulti(dev, inc);
4611 	}
4612 
4613 	return ret;
4614 }
4615 
4616 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags)
4617 {
4618 	unsigned int changes = dev->flags ^ old_flags;
4619 
4620 	if (changes & IFF_UP) {
4621 		if (dev->flags & IFF_UP)
4622 			call_netdevice_notifiers(NETDEV_UP, dev);
4623 		else
4624 			call_netdevice_notifiers(NETDEV_DOWN, dev);
4625 	}
4626 
4627 	if (dev->flags & IFF_UP &&
4628 	    (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE)))
4629 		call_netdevice_notifiers(NETDEV_CHANGE, dev);
4630 }
4631 
4632 /**
4633  *	dev_change_flags - change device settings
4634  *	@dev: device
4635  *	@flags: device state flags
4636  *
4637  *	Change settings on device based state flags. The flags are
4638  *	in the userspace exported format.
4639  */
4640 int dev_change_flags(struct net_device *dev, unsigned flags)
4641 {
4642 	int ret, changes;
4643 	int old_flags = dev->flags;
4644 
4645 	ret = __dev_change_flags(dev, flags);
4646 	if (ret < 0)
4647 		return ret;
4648 
4649 	changes = old_flags ^ dev->flags;
4650 	if (changes)
4651 		rtmsg_ifinfo(RTM_NEWLINK, dev, changes);
4652 
4653 	__dev_notify_flags(dev, old_flags);
4654 	return ret;
4655 }
4656 EXPORT_SYMBOL(dev_change_flags);
4657 
4658 /**
4659  *	dev_set_mtu - Change maximum transfer unit
4660  *	@dev: device
4661  *	@new_mtu: new transfer unit
4662  *
4663  *	Change the maximum transfer size of the network device.
4664  */
4665 int dev_set_mtu(struct net_device *dev, int new_mtu)
4666 {
4667 	const struct net_device_ops *ops = dev->netdev_ops;
4668 	int err;
4669 
4670 	if (new_mtu == dev->mtu)
4671 		return 0;
4672 
4673 	/*	MTU must be positive.	 */
4674 	if (new_mtu < 0)
4675 		return -EINVAL;
4676 
4677 	if (!netif_device_present(dev))
4678 		return -ENODEV;
4679 
4680 	err = 0;
4681 	if (ops->ndo_change_mtu)
4682 		err = ops->ndo_change_mtu(dev, new_mtu);
4683 	else
4684 		dev->mtu = new_mtu;
4685 
4686 	if (!err && dev->flags & IFF_UP)
4687 		call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
4688 	return err;
4689 }
4690 EXPORT_SYMBOL(dev_set_mtu);
4691 
4692 /**
4693  *	dev_set_group - Change group this device belongs to
4694  *	@dev: device
4695  *	@new_group: group this device should belong to
4696  */
4697 void dev_set_group(struct net_device *dev, int new_group)
4698 {
4699 	dev->group = new_group;
4700 }
4701 EXPORT_SYMBOL(dev_set_group);
4702 
4703 /**
4704  *	dev_set_mac_address - Change Media Access Control Address
4705  *	@dev: device
4706  *	@sa: new address
4707  *
4708  *	Change the hardware (MAC) address of the device
4709  */
4710 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
4711 {
4712 	const struct net_device_ops *ops = dev->netdev_ops;
4713 	int err;
4714 
4715 	if (!ops->ndo_set_mac_address)
4716 		return -EOPNOTSUPP;
4717 	if (sa->sa_family != dev->type)
4718 		return -EINVAL;
4719 	if (!netif_device_present(dev))
4720 		return -ENODEV;
4721 	err = ops->ndo_set_mac_address(dev, sa);
4722 	if (!err)
4723 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
4724 	return err;
4725 }
4726 EXPORT_SYMBOL(dev_set_mac_address);
4727 
4728 /*
4729  *	Perform the SIOCxIFxxx calls, inside rcu_read_lock()
4730  */
4731 static int dev_ifsioc_locked(struct net *net, struct ifreq *ifr, unsigned int cmd)
4732 {
4733 	int err;
4734 	struct net_device *dev = dev_get_by_name_rcu(net, ifr->ifr_name);
4735 
4736 	if (!dev)
4737 		return -ENODEV;
4738 
4739 	switch (cmd) {
4740 	case SIOCGIFFLAGS:	/* Get interface flags */
4741 		ifr->ifr_flags = (short) dev_get_flags(dev);
4742 		return 0;
4743 
4744 	case SIOCGIFMETRIC:	/* Get the metric on the interface
4745 				   (currently unused) */
4746 		ifr->ifr_metric = 0;
4747 		return 0;
4748 
4749 	case SIOCGIFMTU:	/* Get the MTU of a device */
4750 		ifr->ifr_mtu = dev->mtu;
4751 		return 0;
4752 
4753 	case SIOCGIFHWADDR:
4754 		if (!dev->addr_len)
4755 			memset(ifr->ifr_hwaddr.sa_data, 0, sizeof ifr->ifr_hwaddr.sa_data);
4756 		else
4757 			memcpy(ifr->ifr_hwaddr.sa_data, dev->dev_addr,
4758 			       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
4759 		ifr->ifr_hwaddr.sa_family = dev->type;
4760 		return 0;
4761 
4762 	case SIOCGIFSLAVE:
4763 		err = -EINVAL;
4764 		break;
4765 
4766 	case SIOCGIFMAP:
4767 		ifr->ifr_map.mem_start = dev->mem_start;
4768 		ifr->ifr_map.mem_end   = dev->mem_end;
4769 		ifr->ifr_map.base_addr = dev->base_addr;
4770 		ifr->ifr_map.irq       = dev->irq;
4771 		ifr->ifr_map.dma       = dev->dma;
4772 		ifr->ifr_map.port      = dev->if_port;
4773 		return 0;
4774 
4775 	case SIOCGIFINDEX:
4776 		ifr->ifr_ifindex = dev->ifindex;
4777 		return 0;
4778 
4779 	case SIOCGIFTXQLEN:
4780 		ifr->ifr_qlen = dev->tx_queue_len;
4781 		return 0;
4782 
4783 	default:
4784 		/* dev_ioctl() should ensure this case
4785 		 * is never reached
4786 		 */
4787 		WARN_ON(1);
4788 		err = -ENOTTY;
4789 		break;
4790 
4791 	}
4792 	return err;
4793 }
4794 
4795 /*
4796  *	Perform the SIOCxIFxxx calls, inside rtnl_lock()
4797  */
4798 static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd)
4799 {
4800 	int err;
4801 	struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name);
4802 	const struct net_device_ops *ops;
4803 
4804 	if (!dev)
4805 		return -ENODEV;
4806 
4807 	ops = dev->netdev_ops;
4808 
4809 	switch (cmd) {
4810 	case SIOCSIFFLAGS:	/* Set interface flags */
4811 		return dev_change_flags(dev, ifr->ifr_flags);
4812 
4813 	case SIOCSIFMETRIC:	/* Set the metric on the interface
4814 				   (currently unused) */
4815 		return -EOPNOTSUPP;
4816 
4817 	case SIOCSIFMTU:	/* Set the MTU of a device */
4818 		return dev_set_mtu(dev, ifr->ifr_mtu);
4819 
4820 	case SIOCSIFHWADDR:
4821 		return dev_set_mac_address(dev, &ifr->ifr_hwaddr);
4822 
4823 	case SIOCSIFHWBROADCAST:
4824 		if (ifr->ifr_hwaddr.sa_family != dev->type)
4825 			return -EINVAL;
4826 		memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
4827 		       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
4828 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
4829 		return 0;
4830 
4831 	case SIOCSIFMAP:
4832 		if (ops->ndo_set_config) {
4833 			if (!netif_device_present(dev))
4834 				return -ENODEV;
4835 			return ops->ndo_set_config(dev, &ifr->ifr_map);
4836 		}
4837 		return -EOPNOTSUPP;
4838 
4839 	case SIOCADDMULTI:
4840 		if ((!ops->ndo_set_multicast_list && !ops->ndo_set_rx_mode) ||
4841 		    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
4842 			return -EINVAL;
4843 		if (!netif_device_present(dev))
4844 			return -ENODEV;
4845 		return dev_mc_add_global(dev, ifr->ifr_hwaddr.sa_data);
4846 
4847 	case SIOCDELMULTI:
4848 		if ((!ops->ndo_set_multicast_list && !ops->ndo_set_rx_mode) ||
4849 		    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
4850 			return -EINVAL;
4851 		if (!netif_device_present(dev))
4852 			return -ENODEV;
4853 		return dev_mc_del_global(dev, ifr->ifr_hwaddr.sa_data);
4854 
4855 	case SIOCSIFTXQLEN:
4856 		if (ifr->ifr_qlen < 0)
4857 			return -EINVAL;
4858 		dev->tx_queue_len = ifr->ifr_qlen;
4859 		return 0;
4860 
4861 	case SIOCSIFNAME:
4862 		ifr->ifr_newname[IFNAMSIZ-1] = '\0';
4863 		return dev_change_name(dev, ifr->ifr_newname);
4864 
4865 	/*
4866 	 *	Unknown or private ioctl
4867 	 */
4868 	default:
4869 		if ((cmd >= SIOCDEVPRIVATE &&
4870 		    cmd <= SIOCDEVPRIVATE + 15) ||
4871 		    cmd == SIOCBONDENSLAVE ||
4872 		    cmd == SIOCBONDRELEASE ||
4873 		    cmd == SIOCBONDSETHWADDR ||
4874 		    cmd == SIOCBONDSLAVEINFOQUERY ||
4875 		    cmd == SIOCBONDINFOQUERY ||
4876 		    cmd == SIOCBONDCHANGEACTIVE ||
4877 		    cmd == SIOCGMIIPHY ||
4878 		    cmd == SIOCGMIIREG ||
4879 		    cmd == SIOCSMIIREG ||
4880 		    cmd == SIOCBRADDIF ||
4881 		    cmd == SIOCBRDELIF ||
4882 		    cmd == SIOCSHWTSTAMP ||
4883 		    cmd == SIOCWANDEV) {
4884 			err = -EOPNOTSUPP;
4885 			if (ops->ndo_do_ioctl) {
4886 				if (netif_device_present(dev))
4887 					err = ops->ndo_do_ioctl(dev, ifr, cmd);
4888 				else
4889 					err = -ENODEV;
4890 			}
4891 		} else
4892 			err = -EINVAL;
4893 
4894 	}
4895 	return err;
4896 }
4897 
4898 /*
4899  *	This function handles all "interface"-type I/O control requests. The actual
4900  *	'doing' part of this is dev_ifsioc above.
4901  */
4902 
4903 /**
4904  *	dev_ioctl	-	network device ioctl
4905  *	@net: the applicable net namespace
4906  *	@cmd: command to issue
4907  *	@arg: pointer to a struct ifreq in user space
4908  *
4909  *	Issue ioctl functions to devices. This is normally called by the
4910  *	user space syscall interfaces but can sometimes be useful for
4911  *	other purposes. The return value is the return from the syscall if
4912  *	positive or a negative errno code on error.
4913  */
4914 
4915 int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg)
4916 {
4917 	struct ifreq ifr;
4918 	int ret;
4919 	char *colon;
4920 
4921 	/* One special case: SIOCGIFCONF takes ifconf argument
4922 	   and requires shared lock, because it sleeps writing
4923 	   to user space.
4924 	 */
4925 
4926 	if (cmd == SIOCGIFCONF) {
4927 		rtnl_lock();
4928 		ret = dev_ifconf(net, (char __user *) arg);
4929 		rtnl_unlock();
4930 		return ret;
4931 	}
4932 	if (cmd == SIOCGIFNAME)
4933 		return dev_ifname(net, (struct ifreq __user *)arg);
4934 
4935 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
4936 		return -EFAULT;
4937 
4938 	ifr.ifr_name[IFNAMSIZ-1] = 0;
4939 
4940 	colon = strchr(ifr.ifr_name, ':');
4941 	if (colon)
4942 		*colon = 0;
4943 
4944 	/*
4945 	 *	See which interface the caller is talking about.
4946 	 */
4947 
4948 	switch (cmd) {
4949 	/*
4950 	 *	These ioctl calls:
4951 	 *	- can be done by all.
4952 	 *	- atomic and do not require locking.
4953 	 *	- return a value
4954 	 */
4955 	case SIOCGIFFLAGS:
4956 	case SIOCGIFMETRIC:
4957 	case SIOCGIFMTU:
4958 	case SIOCGIFHWADDR:
4959 	case SIOCGIFSLAVE:
4960 	case SIOCGIFMAP:
4961 	case SIOCGIFINDEX:
4962 	case SIOCGIFTXQLEN:
4963 		dev_load(net, ifr.ifr_name);
4964 		rcu_read_lock();
4965 		ret = dev_ifsioc_locked(net, &ifr, cmd);
4966 		rcu_read_unlock();
4967 		if (!ret) {
4968 			if (colon)
4969 				*colon = ':';
4970 			if (copy_to_user(arg, &ifr,
4971 					 sizeof(struct ifreq)))
4972 				ret = -EFAULT;
4973 		}
4974 		return ret;
4975 
4976 	case SIOCETHTOOL:
4977 		dev_load(net, ifr.ifr_name);
4978 		rtnl_lock();
4979 		ret = dev_ethtool(net, &ifr);
4980 		rtnl_unlock();
4981 		if (!ret) {
4982 			if (colon)
4983 				*colon = ':';
4984 			if (copy_to_user(arg, &ifr,
4985 					 sizeof(struct ifreq)))
4986 				ret = -EFAULT;
4987 		}
4988 		return ret;
4989 
4990 	/*
4991 	 *	These ioctl calls:
4992 	 *	- require superuser power.
4993 	 *	- require strict serialization.
4994 	 *	- return a value
4995 	 */
4996 	case SIOCGMIIPHY:
4997 	case SIOCGMIIREG:
4998 	case SIOCSIFNAME:
4999 		if (!capable(CAP_NET_ADMIN))
5000 			return -EPERM;
5001 		dev_load(net, ifr.ifr_name);
5002 		rtnl_lock();
5003 		ret = dev_ifsioc(net, &ifr, cmd);
5004 		rtnl_unlock();
5005 		if (!ret) {
5006 			if (colon)
5007 				*colon = ':';
5008 			if (copy_to_user(arg, &ifr,
5009 					 sizeof(struct ifreq)))
5010 				ret = -EFAULT;
5011 		}
5012 		return ret;
5013 
5014 	/*
5015 	 *	These ioctl calls:
5016 	 *	- require superuser power.
5017 	 *	- require strict serialization.
5018 	 *	- do not return a value
5019 	 */
5020 	case SIOCSIFFLAGS:
5021 	case SIOCSIFMETRIC:
5022 	case SIOCSIFMTU:
5023 	case SIOCSIFMAP:
5024 	case SIOCSIFHWADDR:
5025 	case SIOCSIFSLAVE:
5026 	case SIOCADDMULTI:
5027 	case SIOCDELMULTI:
5028 	case SIOCSIFHWBROADCAST:
5029 	case SIOCSIFTXQLEN:
5030 	case SIOCSMIIREG:
5031 	case SIOCBONDENSLAVE:
5032 	case SIOCBONDRELEASE:
5033 	case SIOCBONDSETHWADDR:
5034 	case SIOCBONDCHANGEACTIVE:
5035 	case SIOCBRADDIF:
5036 	case SIOCBRDELIF:
5037 	case SIOCSHWTSTAMP:
5038 		if (!capable(CAP_NET_ADMIN))
5039 			return -EPERM;
5040 		/* fall through */
5041 	case SIOCBONDSLAVEINFOQUERY:
5042 	case SIOCBONDINFOQUERY:
5043 		dev_load(net, ifr.ifr_name);
5044 		rtnl_lock();
5045 		ret = dev_ifsioc(net, &ifr, cmd);
5046 		rtnl_unlock();
5047 		return ret;
5048 
5049 	case SIOCGIFMEM:
5050 		/* Get the per device memory space. We can add this but
5051 		 * currently do not support it */
5052 	case SIOCSIFMEM:
5053 		/* Set the per device memory buffer space.
5054 		 * Not applicable in our case */
5055 	case SIOCSIFLINK:
5056 		return -ENOTTY;
5057 
5058 	/*
5059 	 *	Unknown or private ioctl.
5060 	 */
5061 	default:
5062 		if (cmd == SIOCWANDEV ||
5063 		    (cmd >= SIOCDEVPRIVATE &&
5064 		     cmd <= SIOCDEVPRIVATE + 15)) {
5065 			dev_load(net, ifr.ifr_name);
5066 			rtnl_lock();
5067 			ret = dev_ifsioc(net, &ifr, cmd);
5068 			rtnl_unlock();
5069 			if (!ret && copy_to_user(arg, &ifr,
5070 						 sizeof(struct ifreq)))
5071 				ret = -EFAULT;
5072 			return ret;
5073 		}
5074 		/* Take care of Wireless Extensions */
5075 		if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST)
5076 			return wext_handle_ioctl(net, &ifr, cmd, arg);
5077 		return -ENOTTY;
5078 	}
5079 }
5080 
5081 
5082 /**
5083  *	dev_new_index	-	allocate an ifindex
5084  *	@net: the applicable net namespace
5085  *
5086  *	Returns a suitable unique value for a new device interface
5087  *	number.  The caller must hold the rtnl semaphore or the
5088  *	dev_base_lock to be sure it remains unique.
5089  */
5090 static int dev_new_index(struct net *net)
5091 {
5092 	static int ifindex;
5093 	for (;;) {
5094 		if (++ifindex <= 0)
5095 			ifindex = 1;
5096 		if (!__dev_get_by_index(net, ifindex))
5097 			return ifindex;
5098 	}
5099 }
5100 
5101 /* Delayed registration/unregisteration */
5102 static LIST_HEAD(net_todo_list);
5103 
5104 static void net_set_todo(struct net_device *dev)
5105 {
5106 	list_add_tail(&dev->todo_list, &net_todo_list);
5107 }
5108 
5109 static void rollback_registered_many(struct list_head *head)
5110 {
5111 	struct net_device *dev, *tmp;
5112 
5113 	BUG_ON(dev_boot_phase);
5114 	ASSERT_RTNL();
5115 
5116 	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
5117 		/* Some devices call without registering
5118 		 * for initialization unwind. Remove those
5119 		 * devices and proceed with the remaining.
5120 		 */
5121 		if (dev->reg_state == NETREG_UNINITIALIZED) {
5122 			pr_debug("unregister_netdevice: device %s/%p never "
5123 				 "was registered\n", dev->name, dev);
5124 
5125 			WARN_ON(1);
5126 			list_del(&dev->unreg_list);
5127 			continue;
5128 		}
5129 		dev->dismantle = true;
5130 		BUG_ON(dev->reg_state != NETREG_REGISTERED);
5131 	}
5132 
5133 	/* If device is running, close it first. */
5134 	dev_close_many(head);
5135 
5136 	list_for_each_entry(dev, head, unreg_list) {
5137 		/* And unlink it from device chain. */
5138 		unlist_netdevice(dev);
5139 
5140 		dev->reg_state = NETREG_UNREGISTERING;
5141 	}
5142 
5143 	synchronize_net();
5144 
5145 	list_for_each_entry(dev, head, unreg_list) {
5146 		/* Shutdown queueing discipline. */
5147 		dev_shutdown(dev);
5148 
5149 
5150 		/* Notify protocols, that we are about to destroy
5151 		   this device. They should clean all the things.
5152 		*/
5153 		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5154 
5155 		if (!dev->rtnl_link_ops ||
5156 		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
5157 			rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
5158 
5159 		/*
5160 		 *	Flush the unicast and multicast chains
5161 		 */
5162 		dev_uc_flush(dev);
5163 		dev_mc_flush(dev);
5164 
5165 		if (dev->netdev_ops->ndo_uninit)
5166 			dev->netdev_ops->ndo_uninit(dev);
5167 
5168 		/* Notifier chain MUST detach us from master device. */
5169 		WARN_ON(dev->master);
5170 
5171 		/* Remove entries from kobject tree */
5172 		netdev_unregister_kobject(dev);
5173 	}
5174 
5175 	/* Process any work delayed until the end of the batch */
5176 	dev = list_first_entry(head, struct net_device, unreg_list);
5177 	call_netdevice_notifiers(NETDEV_UNREGISTER_BATCH, dev);
5178 
5179 	rcu_barrier();
5180 
5181 	list_for_each_entry(dev, head, unreg_list)
5182 		dev_put(dev);
5183 }
5184 
5185 static void rollback_registered(struct net_device *dev)
5186 {
5187 	LIST_HEAD(single);
5188 
5189 	list_add(&dev->unreg_list, &single);
5190 	rollback_registered_many(&single);
5191 	list_del(&single);
5192 }
5193 
5194 u32 netdev_fix_features(struct net_device *dev, u32 features)
5195 {
5196 	/* Fix illegal checksum combinations */
5197 	if ((features & NETIF_F_HW_CSUM) &&
5198 	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5199 		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
5200 		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
5201 	}
5202 
5203 	if ((features & NETIF_F_NO_CSUM) &&
5204 	    (features & (NETIF_F_HW_CSUM|NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5205 		netdev_warn(dev, "mixed no checksumming and other settings.\n");
5206 		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM|NETIF_F_HW_CSUM);
5207 	}
5208 
5209 	/* Fix illegal SG+CSUM combinations. */
5210 	if ((features & NETIF_F_SG) &&
5211 	    !(features & NETIF_F_ALL_CSUM)) {
5212 		netdev_dbg(dev,
5213 			"Dropping NETIF_F_SG since no checksum feature.\n");
5214 		features &= ~NETIF_F_SG;
5215 	}
5216 
5217 	/* TSO requires that SG is present as well. */
5218 	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
5219 		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
5220 		features &= ~NETIF_F_ALL_TSO;
5221 	}
5222 
5223 	/* TSO ECN requires that TSO is present as well. */
5224 	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
5225 		features &= ~NETIF_F_TSO_ECN;
5226 
5227 	/* Software GSO depends on SG. */
5228 	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
5229 		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
5230 		features &= ~NETIF_F_GSO;
5231 	}
5232 
5233 	/* UFO needs SG and checksumming */
5234 	if (features & NETIF_F_UFO) {
5235 		/* maybe split UFO into V4 and V6? */
5236 		if (!((features & NETIF_F_GEN_CSUM) ||
5237 		    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))
5238 			    == (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5239 			netdev_dbg(dev,
5240 				"Dropping NETIF_F_UFO since no checksum offload features.\n");
5241 			features &= ~NETIF_F_UFO;
5242 		}
5243 
5244 		if (!(features & NETIF_F_SG)) {
5245 			netdev_dbg(dev,
5246 				"Dropping NETIF_F_UFO since no NETIF_F_SG feature.\n");
5247 			features &= ~NETIF_F_UFO;
5248 		}
5249 	}
5250 
5251 	return features;
5252 }
5253 EXPORT_SYMBOL(netdev_fix_features);
5254 
5255 int __netdev_update_features(struct net_device *dev)
5256 {
5257 	u32 features;
5258 	int err = 0;
5259 
5260 	ASSERT_RTNL();
5261 
5262 	features = netdev_get_wanted_features(dev);
5263 
5264 	if (dev->netdev_ops->ndo_fix_features)
5265 		features = dev->netdev_ops->ndo_fix_features(dev, features);
5266 
5267 	/* driver might be less strict about feature dependencies */
5268 	features = netdev_fix_features(dev, features);
5269 
5270 	if (dev->features == features)
5271 		return 0;
5272 
5273 	netdev_dbg(dev, "Features changed: 0x%08x -> 0x%08x\n",
5274 		dev->features, features);
5275 
5276 	if (dev->netdev_ops->ndo_set_features)
5277 		err = dev->netdev_ops->ndo_set_features(dev, features);
5278 
5279 	if (unlikely(err < 0)) {
5280 		netdev_err(dev,
5281 			"set_features() failed (%d); wanted 0x%08x, left 0x%08x\n",
5282 			err, features, dev->features);
5283 		return -1;
5284 	}
5285 
5286 	if (!err)
5287 		dev->features = features;
5288 
5289 	return 1;
5290 }
5291 
5292 /**
5293  *	netdev_update_features - recalculate device features
5294  *	@dev: the device to check
5295  *
5296  *	Recalculate dev->features set and send notifications if it
5297  *	has changed. Should be called after driver or hardware dependent
5298  *	conditions might have changed that influence the features.
5299  */
5300 void netdev_update_features(struct net_device *dev)
5301 {
5302 	if (__netdev_update_features(dev))
5303 		netdev_features_change(dev);
5304 }
5305 EXPORT_SYMBOL(netdev_update_features);
5306 
5307 /**
5308  *	netdev_change_features - recalculate device features
5309  *	@dev: the device to check
5310  *
5311  *	Recalculate dev->features set and send notifications even
5312  *	if they have not changed. Should be called instead of
5313  *	netdev_update_features() if also dev->vlan_features might
5314  *	have changed to allow the changes to be propagated to stacked
5315  *	VLAN devices.
5316  */
5317 void netdev_change_features(struct net_device *dev)
5318 {
5319 	__netdev_update_features(dev);
5320 	netdev_features_change(dev);
5321 }
5322 EXPORT_SYMBOL(netdev_change_features);
5323 
5324 /**
5325  *	netif_stacked_transfer_operstate -	transfer operstate
5326  *	@rootdev: the root or lower level device to transfer state from
5327  *	@dev: the device to transfer operstate to
5328  *
5329  *	Transfer operational state from root to device. This is normally
5330  *	called when a stacking relationship exists between the root
5331  *	device and the device(a leaf device).
5332  */
5333 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
5334 					struct net_device *dev)
5335 {
5336 	if (rootdev->operstate == IF_OPER_DORMANT)
5337 		netif_dormant_on(dev);
5338 	else
5339 		netif_dormant_off(dev);
5340 
5341 	if (netif_carrier_ok(rootdev)) {
5342 		if (!netif_carrier_ok(dev))
5343 			netif_carrier_on(dev);
5344 	} else {
5345 		if (netif_carrier_ok(dev))
5346 			netif_carrier_off(dev);
5347 	}
5348 }
5349 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
5350 
5351 #ifdef CONFIG_RPS
5352 static int netif_alloc_rx_queues(struct net_device *dev)
5353 {
5354 	unsigned int i, count = dev->num_rx_queues;
5355 	struct netdev_rx_queue *rx;
5356 
5357 	BUG_ON(count < 1);
5358 
5359 	rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL);
5360 	if (!rx) {
5361 		pr_err("netdev: Unable to allocate %u rx queues.\n", count);
5362 		return -ENOMEM;
5363 	}
5364 	dev->_rx = rx;
5365 
5366 	for (i = 0; i < count; i++)
5367 		rx[i].dev = dev;
5368 	return 0;
5369 }
5370 #endif
5371 
5372 static void netdev_init_one_queue(struct net_device *dev,
5373 				  struct netdev_queue *queue, void *_unused)
5374 {
5375 	/* Initialize queue lock */
5376 	spin_lock_init(&queue->_xmit_lock);
5377 	netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
5378 	queue->xmit_lock_owner = -1;
5379 	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
5380 	queue->dev = dev;
5381 }
5382 
5383 static int netif_alloc_netdev_queues(struct net_device *dev)
5384 {
5385 	unsigned int count = dev->num_tx_queues;
5386 	struct netdev_queue *tx;
5387 
5388 	BUG_ON(count < 1);
5389 
5390 	tx = kcalloc(count, sizeof(struct netdev_queue), GFP_KERNEL);
5391 	if (!tx) {
5392 		pr_err("netdev: Unable to allocate %u tx queues.\n",
5393 		       count);
5394 		return -ENOMEM;
5395 	}
5396 	dev->_tx = tx;
5397 
5398 	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
5399 	spin_lock_init(&dev->tx_global_lock);
5400 
5401 	return 0;
5402 }
5403 
5404 /**
5405  *	register_netdevice	- register a network device
5406  *	@dev: device to register
5407  *
5408  *	Take a completed network device structure and add it to the kernel
5409  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
5410  *	chain. 0 is returned on success. A negative errno code is returned
5411  *	on a failure to set up the device, or if the name is a duplicate.
5412  *
5413  *	Callers must hold the rtnl semaphore. You may want
5414  *	register_netdev() instead of this.
5415  *
5416  *	BUGS:
5417  *	The locking appears insufficient to guarantee two parallel registers
5418  *	will not get the same name.
5419  */
5420 
5421 int register_netdevice(struct net_device *dev)
5422 {
5423 	int ret;
5424 	struct net *net = dev_net(dev);
5425 
5426 	BUG_ON(dev_boot_phase);
5427 	ASSERT_RTNL();
5428 
5429 	might_sleep();
5430 
5431 	/* When net_device's are persistent, this will be fatal. */
5432 	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
5433 	BUG_ON(!net);
5434 
5435 	spin_lock_init(&dev->addr_list_lock);
5436 	netdev_set_addr_lockdep_class(dev);
5437 
5438 	dev->iflink = -1;
5439 
5440 	ret = dev_get_valid_name(dev, dev->name);
5441 	if (ret < 0)
5442 		goto out;
5443 
5444 	/* Init, if this function is available */
5445 	if (dev->netdev_ops->ndo_init) {
5446 		ret = dev->netdev_ops->ndo_init(dev);
5447 		if (ret) {
5448 			if (ret > 0)
5449 				ret = -EIO;
5450 			goto out;
5451 		}
5452 	}
5453 
5454 	dev->ifindex = dev_new_index(net);
5455 	if (dev->iflink == -1)
5456 		dev->iflink = dev->ifindex;
5457 
5458 	/* Transfer changeable features to wanted_features and enable
5459 	 * software offloads (GSO and GRO).
5460 	 */
5461 	dev->hw_features |= NETIF_F_SOFT_FEATURES;
5462 	dev->features |= NETIF_F_SOFT_FEATURES;
5463 	dev->wanted_features = dev->features & dev->hw_features;
5464 
5465 	/* Turn on no cache copy if HW is doing checksum */
5466 	dev->hw_features |= NETIF_F_NOCACHE_COPY;
5467 	if ((dev->features & NETIF_F_ALL_CSUM) &&
5468 	    !(dev->features & NETIF_F_NO_CSUM)) {
5469 		dev->wanted_features |= NETIF_F_NOCACHE_COPY;
5470 		dev->features |= NETIF_F_NOCACHE_COPY;
5471 	}
5472 
5473 	/* Enable GRO and NETIF_F_HIGHDMA for vlans by default,
5474 	 * vlan_dev_init() will do the dev->features check, so these features
5475 	 * are enabled only if supported by underlying device.
5476 	 */
5477 	dev->vlan_features |= (NETIF_F_GRO | NETIF_F_HIGHDMA);
5478 
5479 	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
5480 	ret = notifier_to_errno(ret);
5481 	if (ret)
5482 		goto err_uninit;
5483 
5484 	ret = netdev_register_kobject(dev);
5485 	if (ret)
5486 		goto err_uninit;
5487 	dev->reg_state = NETREG_REGISTERED;
5488 
5489 	__netdev_update_features(dev);
5490 
5491 	/*
5492 	 *	Default initial state at registry is that the
5493 	 *	device is present.
5494 	 */
5495 
5496 	set_bit(__LINK_STATE_PRESENT, &dev->state);
5497 
5498 	dev_init_scheduler(dev);
5499 	dev_hold(dev);
5500 	list_netdevice(dev);
5501 
5502 	/* Notify protocols, that a new device appeared. */
5503 	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
5504 	ret = notifier_to_errno(ret);
5505 	if (ret) {
5506 		rollback_registered(dev);
5507 		dev->reg_state = NETREG_UNREGISTERED;
5508 	}
5509 	/*
5510 	 *	Prevent userspace races by waiting until the network
5511 	 *	device is fully setup before sending notifications.
5512 	 */
5513 	if (!dev->rtnl_link_ops ||
5514 	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
5515 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
5516 
5517 out:
5518 	return ret;
5519 
5520 err_uninit:
5521 	if (dev->netdev_ops->ndo_uninit)
5522 		dev->netdev_ops->ndo_uninit(dev);
5523 	goto out;
5524 }
5525 EXPORT_SYMBOL(register_netdevice);
5526 
5527 /**
5528  *	init_dummy_netdev	- init a dummy network device for NAPI
5529  *	@dev: device to init
5530  *
5531  *	This takes a network device structure and initialize the minimum
5532  *	amount of fields so it can be used to schedule NAPI polls without
5533  *	registering a full blown interface. This is to be used by drivers
5534  *	that need to tie several hardware interfaces to a single NAPI
5535  *	poll scheduler due to HW limitations.
5536  */
5537 int init_dummy_netdev(struct net_device *dev)
5538 {
5539 	/* Clear everything. Note we don't initialize spinlocks
5540 	 * are they aren't supposed to be taken by any of the
5541 	 * NAPI code and this dummy netdev is supposed to be
5542 	 * only ever used for NAPI polls
5543 	 */
5544 	memset(dev, 0, sizeof(struct net_device));
5545 
5546 	/* make sure we BUG if trying to hit standard
5547 	 * register/unregister code path
5548 	 */
5549 	dev->reg_state = NETREG_DUMMY;
5550 
5551 	/* NAPI wants this */
5552 	INIT_LIST_HEAD(&dev->napi_list);
5553 
5554 	/* a dummy interface is started by default */
5555 	set_bit(__LINK_STATE_PRESENT, &dev->state);
5556 	set_bit(__LINK_STATE_START, &dev->state);
5557 
5558 	/* Note : We dont allocate pcpu_refcnt for dummy devices,
5559 	 * because users of this 'device' dont need to change
5560 	 * its refcount.
5561 	 */
5562 
5563 	return 0;
5564 }
5565 EXPORT_SYMBOL_GPL(init_dummy_netdev);
5566 
5567 
5568 /**
5569  *	register_netdev	- register a network device
5570  *	@dev: device to register
5571  *
5572  *	Take a completed network device structure and add it to the kernel
5573  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
5574  *	chain. 0 is returned on success. A negative errno code is returned
5575  *	on a failure to set up the device, or if the name is a duplicate.
5576  *
5577  *	This is a wrapper around register_netdevice that takes the rtnl semaphore
5578  *	and expands the device name if you passed a format string to
5579  *	alloc_netdev.
5580  */
5581 int register_netdev(struct net_device *dev)
5582 {
5583 	int err;
5584 
5585 	rtnl_lock();
5586 	err = register_netdevice(dev);
5587 	rtnl_unlock();
5588 	return err;
5589 }
5590 EXPORT_SYMBOL(register_netdev);
5591 
5592 int netdev_refcnt_read(const struct net_device *dev)
5593 {
5594 	int i, refcnt = 0;
5595 
5596 	for_each_possible_cpu(i)
5597 		refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
5598 	return refcnt;
5599 }
5600 EXPORT_SYMBOL(netdev_refcnt_read);
5601 
5602 /*
5603  * netdev_wait_allrefs - wait until all references are gone.
5604  *
5605  * This is called when unregistering network devices.
5606  *
5607  * Any protocol or device that holds a reference should register
5608  * for netdevice notification, and cleanup and put back the
5609  * reference if they receive an UNREGISTER event.
5610  * We can get stuck here if buggy protocols don't correctly
5611  * call dev_put.
5612  */
5613 static void netdev_wait_allrefs(struct net_device *dev)
5614 {
5615 	unsigned long rebroadcast_time, warning_time;
5616 	int refcnt;
5617 
5618 	linkwatch_forget_dev(dev);
5619 
5620 	rebroadcast_time = warning_time = jiffies;
5621 	refcnt = netdev_refcnt_read(dev);
5622 
5623 	while (refcnt != 0) {
5624 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
5625 			rtnl_lock();
5626 
5627 			/* Rebroadcast unregister notification */
5628 			call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5629 			/* don't resend NETDEV_UNREGISTER_BATCH, _BATCH users
5630 			 * should have already handle it the first time */
5631 
5632 			if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
5633 				     &dev->state)) {
5634 				/* We must not have linkwatch events
5635 				 * pending on unregister. If this
5636 				 * happens, we simply run the queue
5637 				 * unscheduled, resulting in a noop
5638 				 * for this device.
5639 				 */
5640 				linkwatch_run_queue();
5641 			}
5642 
5643 			__rtnl_unlock();
5644 
5645 			rebroadcast_time = jiffies;
5646 		}
5647 
5648 		msleep(250);
5649 
5650 		refcnt = netdev_refcnt_read(dev);
5651 
5652 		if (time_after(jiffies, warning_time + 10 * HZ)) {
5653 			printk(KERN_EMERG "unregister_netdevice: "
5654 			       "waiting for %s to become free. Usage "
5655 			       "count = %d\n",
5656 			       dev->name, refcnt);
5657 			warning_time = jiffies;
5658 		}
5659 	}
5660 }
5661 
5662 /* The sequence is:
5663  *
5664  *	rtnl_lock();
5665  *	...
5666  *	register_netdevice(x1);
5667  *	register_netdevice(x2);
5668  *	...
5669  *	unregister_netdevice(y1);
5670  *	unregister_netdevice(y2);
5671  *      ...
5672  *	rtnl_unlock();
5673  *	free_netdev(y1);
5674  *	free_netdev(y2);
5675  *
5676  * We are invoked by rtnl_unlock().
5677  * This allows us to deal with problems:
5678  * 1) We can delete sysfs objects which invoke hotplug
5679  *    without deadlocking with linkwatch via keventd.
5680  * 2) Since we run with the RTNL semaphore not held, we can sleep
5681  *    safely in order to wait for the netdev refcnt to drop to zero.
5682  *
5683  * We must not return until all unregister events added during
5684  * the interval the lock was held have been completed.
5685  */
5686 void netdev_run_todo(void)
5687 {
5688 	struct list_head list;
5689 
5690 	/* Snapshot list, allow later requests */
5691 	list_replace_init(&net_todo_list, &list);
5692 
5693 	__rtnl_unlock();
5694 
5695 	while (!list_empty(&list)) {
5696 		struct net_device *dev
5697 			= list_first_entry(&list, struct net_device, todo_list);
5698 		list_del(&dev->todo_list);
5699 
5700 		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
5701 			printk(KERN_ERR "network todo '%s' but state %d\n",
5702 			       dev->name, dev->reg_state);
5703 			dump_stack();
5704 			continue;
5705 		}
5706 
5707 		dev->reg_state = NETREG_UNREGISTERED;
5708 
5709 		on_each_cpu(flush_backlog, dev, 1);
5710 
5711 		netdev_wait_allrefs(dev);
5712 
5713 		/* paranoia */
5714 		BUG_ON(netdev_refcnt_read(dev));
5715 		WARN_ON(rcu_dereference_raw(dev->ip_ptr));
5716 		WARN_ON(rcu_dereference_raw(dev->ip6_ptr));
5717 		WARN_ON(dev->dn_ptr);
5718 
5719 		if (dev->destructor)
5720 			dev->destructor(dev);
5721 
5722 		/* Free network device */
5723 		kobject_put(&dev->dev.kobj);
5724 	}
5725 }
5726 
5727 /* Convert net_device_stats to rtnl_link_stats64.  They have the same
5728  * fields in the same order, with only the type differing.
5729  */
5730 static void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
5731 				    const struct net_device_stats *netdev_stats)
5732 {
5733 #if BITS_PER_LONG == 64
5734         BUILD_BUG_ON(sizeof(*stats64) != sizeof(*netdev_stats));
5735         memcpy(stats64, netdev_stats, sizeof(*stats64));
5736 #else
5737 	size_t i, n = sizeof(*stats64) / sizeof(u64);
5738 	const unsigned long *src = (const unsigned long *)netdev_stats;
5739 	u64 *dst = (u64 *)stats64;
5740 
5741 	BUILD_BUG_ON(sizeof(*netdev_stats) / sizeof(unsigned long) !=
5742 		     sizeof(*stats64) / sizeof(u64));
5743 	for (i = 0; i < n; i++)
5744 		dst[i] = src[i];
5745 #endif
5746 }
5747 
5748 /**
5749  *	dev_get_stats	- get network device statistics
5750  *	@dev: device to get statistics from
5751  *	@storage: place to store stats
5752  *
5753  *	Get network statistics from device. Return @storage.
5754  *	The device driver may provide its own method by setting
5755  *	dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
5756  *	otherwise the internal statistics structure is used.
5757  */
5758 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
5759 					struct rtnl_link_stats64 *storage)
5760 {
5761 	const struct net_device_ops *ops = dev->netdev_ops;
5762 
5763 	if (ops->ndo_get_stats64) {
5764 		memset(storage, 0, sizeof(*storage));
5765 		ops->ndo_get_stats64(dev, storage);
5766 	} else if (ops->ndo_get_stats) {
5767 		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
5768 	} else {
5769 		netdev_stats_to_stats64(storage, &dev->stats);
5770 	}
5771 	storage->rx_dropped += atomic_long_read(&dev->rx_dropped);
5772 	return storage;
5773 }
5774 EXPORT_SYMBOL(dev_get_stats);
5775 
5776 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
5777 {
5778 	struct netdev_queue *queue = dev_ingress_queue(dev);
5779 
5780 #ifdef CONFIG_NET_CLS_ACT
5781 	if (queue)
5782 		return queue;
5783 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
5784 	if (!queue)
5785 		return NULL;
5786 	netdev_init_one_queue(dev, queue, NULL);
5787 	queue->qdisc = &noop_qdisc;
5788 	queue->qdisc_sleeping = &noop_qdisc;
5789 	rcu_assign_pointer(dev->ingress_queue, queue);
5790 #endif
5791 	return queue;
5792 }
5793 
5794 /**
5795  *	alloc_netdev_mqs - allocate network device
5796  *	@sizeof_priv:	size of private data to allocate space for
5797  *	@name:		device name format string
5798  *	@setup:		callback to initialize device
5799  *	@txqs:		the number of TX subqueues to allocate
5800  *	@rxqs:		the number of RX subqueues to allocate
5801  *
5802  *	Allocates a struct net_device with private data area for driver use
5803  *	and performs basic initialization.  Also allocates subquue structs
5804  *	for each queue on the device.
5805  */
5806 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
5807 		void (*setup)(struct net_device *),
5808 		unsigned int txqs, unsigned int rxqs)
5809 {
5810 	struct net_device *dev;
5811 	size_t alloc_size;
5812 	struct net_device *p;
5813 
5814 	BUG_ON(strlen(name) >= sizeof(dev->name));
5815 
5816 	if (txqs < 1) {
5817 		pr_err("alloc_netdev: Unable to allocate device "
5818 		       "with zero queues.\n");
5819 		return NULL;
5820 	}
5821 
5822 #ifdef CONFIG_RPS
5823 	if (rxqs < 1) {
5824 		pr_err("alloc_netdev: Unable to allocate device "
5825 		       "with zero RX queues.\n");
5826 		return NULL;
5827 	}
5828 #endif
5829 
5830 	alloc_size = sizeof(struct net_device);
5831 	if (sizeof_priv) {
5832 		/* ensure 32-byte alignment of private area */
5833 		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
5834 		alloc_size += sizeof_priv;
5835 	}
5836 	/* ensure 32-byte alignment of whole construct */
5837 	alloc_size += NETDEV_ALIGN - 1;
5838 
5839 	p = kzalloc(alloc_size, GFP_KERNEL);
5840 	if (!p) {
5841 		printk(KERN_ERR "alloc_netdev: Unable to allocate device.\n");
5842 		return NULL;
5843 	}
5844 
5845 	dev = PTR_ALIGN(p, NETDEV_ALIGN);
5846 	dev->padded = (char *)dev - (char *)p;
5847 
5848 	dev->pcpu_refcnt = alloc_percpu(int);
5849 	if (!dev->pcpu_refcnt)
5850 		goto free_p;
5851 
5852 	if (dev_addr_init(dev))
5853 		goto free_pcpu;
5854 
5855 	dev_mc_init(dev);
5856 	dev_uc_init(dev);
5857 
5858 	dev_net_set(dev, &init_net);
5859 
5860 	dev->gso_max_size = GSO_MAX_SIZE;
5861 
5862 	INIT_LIST_HEAD(&dev->ethtool_ntuple_list.list);
5863 	dev->ethtool_ntuple_list.count = 0;
5864 	INIT_LIST_HEAD(&dev->napi_list);
5865 	INIT_LIST_HEAD(&dev->unreg_list);
5866 	INIT_LIST_HEAD(&dev->link_watch_list);
5867 	dev->priv_flags = IFF_XMIT_DST_RELEASE;
5868 	setup(dev);
5869 
5870 	dev->num_tx_queues = txqs;
5871 	dev->real_num_tx_queues = txqs;
5872 	if (netif_alloc_netdev_queues(dev))
5873 		goto free_all;
5874 
5875 #ifdef CONFIG_RPS
5876 	dev->num_rx_queues = rxqs;
5877 	dev->real_num_rx_queues = rxqs;
5878 	if (netif_alloc_rx_queues(dev))
5879 		goto free_all;
5880 #endif
5881 
5882 	strcpy(dev->name, name);
5883 	dev->group = INIT_NETDEV_GROUP;
5884 	return dev;
5885 
5886 free_all:
5887 	free_netdev(dev);
5888 	return NULL;
5889 
5890 free_pcpu:
5891 	free_percpu(dev->pcpu_refcnt);
5892 	kfree(dev->_tx);
5893 #ifdef CONFIG_RPS
5894 	kfree(dev->_rx);
5895 #endif
5896 
5897 free_p:
5898 	kfree(p);
5899 	return NULL;
5900 }
5901 EXPORT_SYMBOL(alloc_netdev_mqs);
5902 
5903 /**
5904  *	free_netdev - free network device
5905  *	@dev: device
5906  *
5907  *	This function does the last stage of destroying an allocated device
5908  * 	interface. The reference to the device object is released.
5909  *	If this is the last reference then it will be freed.
5910  */
5911 void free_netdev(struct net_device *dev)
5912 {
5913 	struct napi_struct *p, *n;
5914 
5915 	release_net(dev_net(dev));
5916 
5917 	kfree(dev->_tx);
5918 #ifdef CONFIG_RPS
5919 	kfree(dev->_rx);
5920 #endif
5921 
5922 	kfree(rcu_dereference_raw(dev->ingress_queue));
5923 
5924 	/* Flush device addresses */
5925 	dev_addr_flush(dev);
5926 
5927 	/* Clear ethtool n-tuple list */
5928 	ethtool_ntuple_flush(dev);
5929 
5930 	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
5931 		netif_napi_del(p);
5932 
5933 	free_percpu(dev->pcpu_refcnt);
5934 	dev->pcpu_refcnt = NULL;
5935 
5936 	/*  Compatibility with error handling in drivers */
5937 	if (dev->reg_state == NETREG_UNINITIALIZED) {
5938 		kfree((char *)dev - dev->padded);
5939 		return;
5940 	}
5941 
5942 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
5943 	dev->reg_state = NETREG_RELEASED;
5944 
5945 	/* will free via device release */
5946 	put_device(&dev->dev);
5947 }
5948 EXPORT_SYMBOL(free_netdev);
5949 
5950 /**
5951  *	synchronize_net -  Synchronize with packet receive processing
5952  *
5953  *	Wait for packets currently being received to be done.
5954  *	Does not block later packets from starting.
5955  */
5956 void synchronize_net(void)
5957 {
5958 	might_sleep();
5959 	synchronize_rcu();
5960 }
5961 EXPORT_SYMBOL(synchronize_net);
5962 
5963 /**
5964  *	unregister_netdevice_queue - remove device from the kernel
5965  *	@dev: device
5966  *	@head: list
5967  *
5968  *	This function shuts down a device interface and removes it
5969  *	from the kernel tables.
5970  *	If head not NULL, device is queued to be unregistered later.
5971  *
5972  *	Callers must hold the rtnl semaphore.  You may want
5973  *	unregister_netdev() instead of this.
5974  */
5975 
5976 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
5977 {
5978 	ASSERT_RTNL();
5979 
5980 	if (head) {
5981 		list_move_tail(&dev->unreg_list, head);
5982 	} else {
5983 		rollback_registered(dev);
5984 		/* Finish processing unregister after unlock */
5985 		net_set_todo(dev);
5986 	}
5987 }
5988 EXPORT_SYMBOL(unregister_netdevice_queue);
5989 
5990 /**
5991  *	unregister_netdevice_many - unregister many devices
5992  *	@head: list of devices
5993  */
5994 void unregister_netdevice_many(struct list_head *head)
5995 {
5996 	struct net_device *dev;
5997 
5998 	if (!list_empty(head)) {
5999 		rollback_registered_many(head);
6000 		list_for_each_entry(dev, head, unreg_list)
6001 			net_set_todo(dev);
6002 	}
6003 }
6004 EXPORT_SYMBOL(unregister_netdevice_many);
6005 
6006 /**
6007  *	unregister_netdev - remove device from the kernel
6008  *	@dev: device
6009  *
6010  *	This function shuts down a device interface and removes it
6011  *	from the kernel tables.
6012  *
6013  *	This is just a wrapper for unregister_netdevice that takes
6014  *	the rtnl semaphore.  In general you want to use this and not
6015  *	unregister_netdevice.
6016  */
6017 void unregister_netdev(struct net_device *dev)
6018 {
6019 	rtnl_lock();
6020 	unregister_netdevice(dev);
6021 	rtnl_unlock();
6022 }
6023 EXPORT_SYMBOL(unregister_netdev);
6024 
6025 /**
6026  *	dev_change_net_namespace - move device to different nethost namespace
6027  *	@dev: device
6028  *	@net: network namespace
6029  *	@pat: If not NULL name pattern to try if the current device name
6030  *	      is already taken in the destination network namespace.
6031  *
6032  *	This function shuts down a device interface and moves it
6033  *	to a new network namespace. On success 0 is returned, on
6034  *	a failure a netagive errno code is returned.
6035  *
6036  *	Callers must hold the rtnl semaphore.
6037  */
6038 
6039 int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat)
6040 {
6041 	int err;
6042 
6043 	ASSERT_RTNL();
6044 
6045 	/* Don't allow namespace local devices to be moved. */
6046 	err = -EINVAL;
6047 	if (dev->features & NETIF_F_NETNS_LOCAL)
6048 		goto out;
6049 
6050 	/* Ensure the device has been registrered */
6051 	err = -EINVAL;
6052 	if (dev->reg_state != NETREG_REGISTERED)
6053 		goto out;
6054 
6055 	/* Get out if there is nothing todo */
6056 	err = 0;
6057 	if (net_eq(dev_net(dev), net))
6058 		goto out;
6059 
6060 	/* Pick the destination device name, and ensure
6061 	 * we can use it in the destination network namespace.
6062 	 */
6063 	err = -EEXIST;
6064 	if (__dev_get_by_name(net, dev->name)) {
6065 		/* We get here if we can't use the current device name */
6066 		if (!pat)
6067 			goto out;
6068 		if (dev_get_valid_name(dev, pat) < 0)
6069 			goto out;
6070 	}
6071 
6072 	/*
6073 	 * And now a mini version of register_netdevice unregister_netdevice.
6074 	 */
6075 
6076 	/* If device is running close it first. */
6077 	dev_close(dev);
6078 
6079 	/* And unlink it from device chain */
6080 	err = -ENODEV;
6081 	unlist_netdevice(dev);
6082 
6083 	synchronize_net();
6084 
6085 	/* Shutdown queueing discipline. */
6086 	dev_shutdown(dev);
6087 
6088 	/* Notify protocols, that we are about to destroy
6089 	   this device. They should clean all the things.
6090 
6091 	   Note that dev->reg_state stays at NETREG_REGISTERED.
6092 	   This is wanted because this way 8021q and macvlan know
6093 	   the device is just moving and can keep their slaves up.
6094 	*/
6095 	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
6096 	call_netdevice_notifiers(NETDEV_UNREGISTER_BATCH, dev);
6097 
6098 	/*
6099 	 *	Flush the unicast and multicast chains
6100 	 */
6101 	dev_uc_flush(dev);
6102 	dev_mc_flush(dev);
6103 
6104 	/* Actually switch the network namespace */
6105 	dev_net_set(dev, net);
6106 
6107 	/* If there is an ifindex conflict assign a new one */
6108 	if (__dev_get_by_index(net, dev->ifindex)) {
6109 		int iflink = (dev->iflink == dev->ifindex);
6110 		dev->ifindex = dev_new_index(net);
6111 		if (iflink)
6112 			dev->iflink = dev->ifindex;
6113 	}
6114 
6115 	/* Fixup kobjects */
6116 	err = device_rename(&dev->dev, dev->name);
6117 	WARN_ON(err);
6118 
6119 	/* Add the device back in the hashes */
6120 	list_netdevice(dev);
6121 
6122 	/* Notify protocols, that a new device appeared. */
6123 	call_netdevice_notifiers(NETDEV_REGISTER, dev);
6124 
6125 	/*
6126 	 *	Prevent userspace races by waiting until the network
6127 	 *	device is fully setup before sending notifications.
6128 	 */
6129 	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
6130 
6131 	synchronize_net();
6132 	err = 0;
6133 out:
6134 	return err;
6135 }
6136 EXPORT_SYMBOL_GPL(dev_change_net_namespace);
6137 
6138 static int dev_cpu_callback(struct notifier_block *nfb,
6139 			    unsigned long action,
6140 			    void *ocpu)
6141 {
6142 	struct sk_buff **list_skb;
6143 	struct sk_buff *skb;
6144 	unsigned int cpu, oldcpu = (unsigned long)ocpu;
6145 	struct softnet_data *sd, *oldsd;
6146 
6147 	if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
6148 		return NOTIFY_OK;
6149 
6150 	local_irq_disable();
6151 	cpu = smp_processor_id();
6152 	sd = &per_cpu(softnet_data, cpu);
6153 	oldsd = &per_cpu(softnet_data, oldcpu);
6154 
6155 	/* Find end of our completion_queue. */
6156 	list_skb = &sd->completion_queue;
6157 	while (*list_skb)
6158 		list_skb = &(*list_skb)->next;
6159 	/* Append completion queue from offline CPU. */
6160 	*list_skb = oldsd->completion_queue;
6161 	oldsd->completion_queue = NULL;
6162 
6163 	/* Append output queue from offline CPU. */
6164 	if (oldsd->output_queue) {
6165 		*sd->output_queue_tailp = oldsd->output_queue;
6166 		sd->output_queue_tailp = oldsd->output_queue_tailp;
6167 		oldsd->output_queue = NULL;
6168 		oldsd->output_queue_tailp = &oldsd->output_queue;
6169 	}
6170 
6171 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
6172 	local_irq_enable();
6173 
6174 	/* Process offline CPU's input_pkt_queue */
6175 	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
6176 		netif_rx(skb);
6177 		input_queue_head_incr(oldsd);
6178 	}
6179 	while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
6180 		netif_rx(skb);
6181 		input_queue_head_incr(oldsd);
6182 	}
6183 
6184 	return NOTIFY_OK;
6185 }
6186 
6187 
6188 /**
6189  *	netdev_increment_features - increment feature set by one
6190  *	@all: current feature set
6191  *	@one: new feature set
6192  *	@mask: mask feature set
6193  *
6194  *	Computes a new feature set after adding a device with feature set
6195  *	@one to the master device with current feature set @all.  Will not
6196  *	enable anything that is off in @mask. Returns the new feature set.
6197  */
6198 u32 netdev_increment_features(u32 all, u32 one, u32 mask)
6199 {
6200 	if (mask & NETIF_F_GEN_CSUM)
6201 		mask |= NETIF_F_ALL_CSUM;
6202 	mask |= NETIF_F_VLAN_CHALLENGED;
6203 
6204 	all |= one & (NETIF_F_ONE_FOR_ALL|NETIF_F_ALL_CSUM) & mask;
6205 	all &= one | ~NETIF_F_ALL_FOR_ALL;
6206 
6207 	/* If device needs checksumming, downgrade to it. */
6208 	if (all & (NETIF_F_ALL_CSUM & ~NETIF_F_NO_CSUM))
6209 		all &= ~NETIF_F_NO_CSUM;
6210 
6211 	/* If one device supports hw checksumming, set for all. */
6212 	if (all & NETIF_F_GEN_CSUM)
6213 		all &= ~(NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM);
6214 
6215 	return all;
6216 }
6217 EXPORT_SYMBOL(netdev_increment_features);
6218 
6219 static struct hlist_head *netdev_create_hash(void)
6220 {
6221 	int i;
6222 	struct hlist_head *hash;
6223 
6224 	hash = kmalloc(sizeof(*hash) * NETDEV_HASHENTRIES, GFP_KERNEL);
6225 	if (hash != NULL)
6226 		for (i = 0; i < NETDEV_HASHENTRIES; i++)
6227 			INIT_HLIST_HEAD(&hash[i]);
6228 
6229 	return hash;
6230 }
6231 
6232 /* Initialize per network namespace state */
6233 static int __net_init netdev_init(struct net *net)
6234 {
6235 	INIT_LIST_HEAD(&net->dev_base_head);
6236 
6237 	net->dev_name_head = netdev_create_hash();
6238 	if (net->dev_name_head == NULL)
6239 		goto err_name;
6240 
6241 	net->dev_index_head = netdev_create_hash();
6242 	if (net->dev_index_head == NULL)
6243 		goto err_idx;
6244 
6245 	return 0;
6246 
6247 err_idx:
6248 	kfree(net->dev_name_head);
6249 err_name:
6250 	return -ENOMEM;
6251 }
6252 
6253 /**
6254  *	netdev_drivername - network driver for the device
6255  *	@dev: network device
6256  *	@buffer: buffer for resulting name
6257  *	@len: size of buffer
6258  *
6259  *	Determine network driver for device.
6260  */
6261 char *netdev_drivername(const struct net_device *dev, char *buffer, int len)
6262 {
6263 	const struct device_driver *driver;
6264 	const struct device *parent;
6265 
6266 	if (len <= 0 || !buffer)
6267 		return buffer;
6268 	buffer[0] = 0;
6269 
6270 	parent = dev->dev.parent;
6271 
6272 	if (!parent)
6273 		return buffer;
6274 
6275 	driver = parent->driver;
6276 	if (driver && driver->name)
6277 		strlcpy(buffer, driver->name, len);
6278 	return buffer;
6279 }
6280 
6281 static int __netdev_printk(const char *level, const struct net_device *dev,
6282 			   struct va_format *vaf)
6283 {
6284 	int r;
6285 
6286 	if (dev && dev->dev.parent)
6287 		r = dev_printk(level, dev->dev.parent, "%s: %pV",
6288 			       netdev_name(dev), vaf);
6289 	else if (dev)
6290 		r = printk("%s%s: %pV", level, netdev_name(dev), vaf);
6291 	else
6292 		r = printk("%s(NULL net_device): %pV", level, vaf);
6293 
6294 	return r;
6295 }
6296 
6297 int netdev_printk(const char *level, const struct net_device *dev,
6298 		  const char *format, ...)
6299 {
6300 	struct va_format vaf;
6301 	va_list args;
6302 	int r;
6303 
6304 	va_start(args, format);
6305 
6306 	vaf.fmt = format;
6307 	vaf.va = &args;
6308 
6309 	r = __netdev_printk(level, dev, &vaf);
6310 	va_end(args);
6311 
6312 	return r;
6313 }
6314 EXPORT_SYMBOL(netdev_printk);
6315 
6316 #define define_netdev_printk_level(func, level)			\
6317 int func(const struct net_device *dev, const char *fmt, ...)	\
6318 {								\
6319 	int r;							\
6320 	struct va_format vaf;					\
6321 	va_list args;						\
6322 								\
6323 	va_start(args, fmt);					\
6324 								\
6325 	vaf.fmt = fmt;						\
6326 	vaf.va = &args;						\
6327 								\
6328 	r = __netdev_printk(level, dev, &vaf);			\
6329 	va_end(args);						\
6330 								\
6331 	return r;						\
6332 }								\
6333 EXPORT_SYMBOL(func);
6334 
6335 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
6336 define_netdev_printk_level(netdev_alert, KERN_ALERT);
6337 define_netdev_printk_level(netdev_crit, KERN_CRIT);
6338 define_netdev_printk_level(netdev_err, KERN_ERR);
6339 define_netdev_printk_level(netdev_warn, KERN_WARNING);
6340 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
6341 define_netdev_printk_level(netdev_info, KERN_INFO);
6342 
6343 static void __net_exit netdev_exit(struct net *net)
6344 {
6345 	kfree(net->dev_name_head);
6346 	kfree(net->dev_index_head);
6347 }
6348 
6349 static struct pernet_operations __net_initdata netdev_net_ops = {
6350 	.init = netdev_init,
6351 	.exit = netdev_exit,
6352 };
6353 
6354 static void __net_exit default_device_exit(struct net *net)
6355 {
6356 	struct net_device *dev, *aux;
6357 	/*
6358 	 * Push all migratable network devices back to the
6359 	 * initial network namespace
6360 	 */
6361 	rtnl_lock();
6362 	for_each_netdev_safe(net, dev, aux) {
6363 		int err;
6364 		char fb_name[IFNAMSIZ];
6365 
6366 		/* Ignore unmoveable devices (i.e. loopback) */
6367 		if (dev->features & NETIF_F_NETNS_LOCAL)
6368 			continue;
6369 
6370 		/* Leave virtual devices for the generic cleanup */
6371 		if (dev->rtnl_link_ops)
6372 			continue;
6373 
6374 		/* Push remaining network devices to init_net */
6375 		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
6376 		err = dev_change_net_namespace(dev, &init_net, fb_name);
6377 		if (err) {
6378 			printk(KERN_EMERG "%s: failed to move %s to init_net: %d\n",
6379 				__func__, dev->name, err);
6380 			BUG();
6381 		}
6382 	}
6383 	rtnl_unlock();
6384 }
6385 
6386 static void __net_exit default_device_exit_batch(struct list_head *net_list)
6387 {
6388 	/* At exit all network devices most be removed from a network
6389 	 * namespace.  Do this in the reverse order of registration.
6390 	 * Do this across as many network namespaces as possible to
6391 	 * improve batching efficiency.
6392 	 */
6393 	struct net_device *dev;
6394 	struct net *net;
6395 	LIST_HEAD(dev_kill_list);
6396 
6397 	rtnl_lock();
6398 	list_for_each_entry(net, net_list, exit_list) {
6399 		for_each_netdev_reverse(net, dev) {
6400 			if (dev->rtnl_link_ops)
6401 				dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
6402 			else
6403 				unregister_netdevice_queue(dev, &dev_kill_list);
6404 		}
6405 	}
6406 	unregister_netdevice_many(&dev_kill_list);
6407 	list_del(&dev_kill_list);
6408 	rtnl_unlock();
6409 }
6410 
6411 static struct pernet_operations __net_initdata default_device_ops = {
6412 	.exit = default_device_exit,
6413 	.exit_batch = default_device_exit_batch,
6414 };
6415 
6416 /*
6417  *	Initialize the DEV module. At boot time this walks the device list and
6418  *	unhooks any devices that fail to initialise (normally hardware not
6419  *	present) and leaves us with a valid list of present and active devices.
6420  *
6421  */
6422 
6423 /*
6424  *       This is called single threaded during boot, so no need
6425  *       to take the rtnl semaphore.
6426  */
6427 static int __init net_dev_init(void)
6428 {
6429 	int i, rc = -ENOMEM;
6430 
6431 	BUG_ON(!dev_boot_phase);
6432 
6433 	if (dev_proc_init())
6434 		goto out;
6435 
6436 	if (netdev_kobject_init())
6437 		goto out;
6438 
6439 	INIT_LIST_HEAD(&ptype_all);
6440 	for (i = 0; i < PTYPE_HASH_SIZE; i++)
6441 		INIT_LIST_HEAD(&ptype_base[i]);
6442 
6443 	if (register_pernet_subsys(&netdev_net_ops))
6444 		goto out;
6445 
6446 	/*
6447 	 *	Initialise the packet receive queues.
6448 	 */
6449 
6450 	for_each_possible_cpu(i) {
6451 		struct softnet_data *sd = &per_cpu(softnet_data, i);
6452 
6453 		memset(sd, 0, sizeof(*sd));
6454 		skb_queue_head_init(&sd->input_pkt_queue);
6455 		skb_queue_head_init(&sd->process_queue);
6456 		sd->completion_queue = NULL;
6457 		INIT_LIST_HEAD(&sd->poll_list);
6458 		sd->output_queue = NULL;
6459 		sd->output_queue_tailp = &sd->output_queue;
6460 #ifdef CONFIG_RPS
6461 		sd->csd.func = rps_trigger_softirq;
6462 		sd->csd.info = sd;
6463 		sd->csd.flags = 0;
6464 		sd->cpu = i;
6465 #endif
6466 
6467 		sd->backlog.poll = process_backlog;
6468 		sd->backlog.weight = weight_p;
6469 		sd->backlog.gro_list = NULL;
6470 		sd->backlog.gro_count = 0;
6471 	}
6472 
6473 	dev_boot_phase = 0;
6474 
6475 	/* The loopback device is special if any other network devices
6476 	 * is present in a network namespace the loopback device must
6477 	 * be present. Since we now dynamically allocate and free the
6478 	 * loopback device ensure this invariant is maintained by
6479 	 * keeping the loopback device as the first device on the
6480 	 * list of network devices.  Ensuring the loopback devices
6481 	 * is the first device that appears and the last network device
6482 	 * that disappears.
6483 	 */
6484 	if (register_pernet_device(&loopback_net_ops))
6485 		goto out;
6486 
6487 	if (register_pernet_device(&default_device_ops))
6488 		goto out;
6489 
6490 	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
6491 	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
6492 
6493 	hotcpu_notifier(dev_cpu_callback, 0);
6494 	dst_init();
6495 	dev_mcast_init();
6496 	rc = 0;
6497 out:
6498 	return rc;
6499 }
6500 
6501 subsys_initcall(net_dev_init);
6502 
6503 static int __init initialize_hashrnd(void)
6504 {
6505 	get_random_bytes(&hashrnd, sizeof(hashrnd));
6506 	return 0;
6507 }
6508 
6509 late_initcall_sync(initialize_hashrnd);
6510 
6511