xref: /linux/net/core/rtnetlink.c (revision 5499b45190237ca90dd2ac86395cf464fe1f4cc7)
1 /*
2  * INET		An implementation of the TCP/IP protocol suite for the LINUX
3  *		operating system.  INET is implemented using the  BSD Socket
4  *		interface as the means of communication with the user level.
5  *
6  *		Routing netlink socket interface: protocol independent part.
7  *
8  * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
9  *
10  *		This program is free software; you can redistribute it and/or
11  *		modify it under the terms of the GNU General Public License
12  *		as published by the Free Software Foundation; either version
13  *		2 of the License, or (at your option) any later version.
14  *
15  *	Fixes:
16  *	Vitaly E. Lavrov		RTA_OK arithmetics was wrong.
17  */
18 
19 #include <linux/errno.h>
20 #include <linux/module.h>
21 #include <linux/types.h>
22 #include <linux/socket.h>
23 #include <linux/kernel.h>
24 #include <linux/timer.h>
25 #include <linux/string.h>
26 #include <linux/sockios.h>
27 #include <linux/net.h>
28 #include <linux/fcntl.h>
29 #include <linux/mm.h>
30 #include <linux/slab.h>
31 #include <linux/interrupt.h>
32 #include <linux/capability.h>
33 #include <linux/skbuff.h>
34 #include <linux/init.h>
35 #include <linux/security.h>
36 #include <linux/mutex.h>
37 #include <linux/if_addr.h>
38 
39 #include <asm/uaccess.h>
40 #include <asm/system.h>
41 
42 #include <linux/inet.h>
43 #include <linux/netdevice.h>
44 #include <net/ip.h>
45 #include <net/protocol.h>
46 #include <net/arp.h>
47 #include <net/route.h>
48 #include <net/udp.h>
49 #include <net/sock.h>
50 #include <net/pkt_sched.h>
51 #include <net/fib_rules.h>
52 #include <net/rtnetlink.h>
53 #include <net/net_namespace.h>
54 
55 struct rtnl_link {
56 	rtnl_doit_func		doit;
57 	rtnl_dumpit_func	dumpit;
58 };
59 
60 static DEFINE_MUTEX(rtnl_mutex);
61 
62 void rtnl_lock(void)
63 {
64 	mutex_lock(&rtnl_mutex);
65 }
66 EXPORT_SYMBOL(rtnl_lock);
67 
68 void __rtnl_unlock(void)
69 {
70 	mutex_unlock(&rtnl_mutex);
71 }
72 
73 void rtnl_unlock(void)
74 {
75 	/* This fellow will unlock it for us. */
76 	netdev_run_todo();
77 }
78 EXPORT_SYMBOL(rtnl_unlock);
79 
80 int rtnl_trylock(void)
81 {
82 	return mutex_trylock(&rtnl_mutex);
83 }
84 EXPORT_SYMBOL(rtnl_trylock);
85 
86 int rtnl_is_locked(void)
87 {
88 	return mutex_is_locked(&rtnl_mutex);
89 }
90 EXPORT_SYMBOL(rtnl_is_locked);
91 
92 #ifdef CONFIG_PROVE_LOCKING
93 int lockdep_rtnl_is_held(void)
94 {
95 	return lockdep_is_held(&rtnl_mutex);
96 }
97 EXPORT_SYMBOL(lockdep_rtnl_is_held);
98 #endif /* #ifdef CONFIG_PROVE_LOCKING */
99 
100 static struct rtnl_link *rtnl_msg_handlers[NPROTO];
101 
102 static inline int rtm_msgindex(int msgtype)
103 {
104 	int msgindex = msgtype - RTM_BASE;
105 
106 	/*
107 	 * msgindex < 0 implies someone tried to register a netlink
108 	 * control code. msgindex >= RTM_NR_MSGTYPES may indicate that
109 	 * the message type has not been added to linux/rtnetlink.h
110 	 */
111 	BUG_ON(msgindex < 0 || msgindex >= RTM_NR_MSGTYPES);
112 
113 	return msgindex;
114 }
115 
116 static rtnl_doit_func rtnl_get_doit(int protocol, int msgindex)
117 {
118 	struct rtnl_link *tab;
119 
120 	tab = rtnl_msg_handlers[protocol];
121 	if (tab == NULL || tab[msgindex].doit == NULL)
122 		tab = rtnl_msg_handlers[PF_UNSPEC];
123 
124 	return tab ? tab[msgindex].doit : NULL;
125 }
126 
127 static rtnl_dumpit_func rtnl_get_dumpit(int protocol, int msgindex)
128 {
129 	struct rtnl_link *tab;
130 
131 	tab = rtnl_msg_handlers[protocol];
132 	if (tab == NULL || tab[msgindex].dumpit == NULL)
133 		tab = rtnl_msg_handlers[PF_UNSPEC];
134 
135 	return tab ? tab[msgindex].dumpit : NULL;
136 }
137 
138 /**
139  * __rtnl_register - Register a rtnetlink message type
140  * @protocol: Protocol family or PF_UNSPEC
141  * @msgtype: rtnetlink message type
142  * @doit: Function pointer called for each request message
143  * @dumpit: Function pointer called for each dump request (NLM_F_DUMP) message
144  *
145  * Registers the specified function pointers (at least one of them has
146  * to be non-NULL) to be called whenever a request message for the
147  * specified protocol family and message type is received.
148  *
149  * The special protocol family PF_UNSPEC may be used to define fallback
150  * function pointers for the case when no entry for the specific protocol
151  * family exists.
152  *
153  * Returns 0 on success or a negative error code.
154  */
155 int __rtnl_register(int protocol, int msgtype,
156 		    rtnl_doit_func doit, rtnl_dumpit_func dumpit)
157 {
158 	struct rtnl_link *tab;
159 	int msgindex;
160 
161 	BUG_ON(protocol < 0 || protocol >= NPROTO);
162 	msgindex = rtm_msgindex(msgtype);
163 
164 	tab = rtnl_msg_handlers[protocol];
165 	if (tab == NULL) {
166 		tab = kcalloc(RTM_NR_MSGTYPES, sizeof(*tab), GFP_KERNEL);
167 		if (tab == NULL)
168 			return -ENOBUFS;
169 
170 		rtnl_msg_handlers[protocol] = tab;
171 	}
172 
173 	if (doit)
174 		tab[msgindex].doit = doit;
175 
176 	if (dumpit)
177 		tab[msgindex].dumpit = dumpit;
178 
179 	return 0;
180 }
181 EXPORT_SYMBOL_GPL(__rtnl_register);
182 
183 /**
184  * rtnl_register - Register a rtnetlink message type
185  *
186  * Identical to __rtnl_register() but panics on failure. This is useful
187  * as failure of this function is very unlikely, it can only happen due
188  * to lack of memory when allocating the chain to store all message
189  * handlers for a protocol. Meant for use in init functions where lack
190  * of memory implies no sense in continueing.
191  */
192 void rtnl_register(int protocol, int msgtype,
193 		   rtnl_doit_func doit, rtnl_dumpit_func dumpit)
194 {
195 	if (__rtnl_register(protocol, msgtype, doit, dumpit) < 0)
196 		panic("Unable to register rtnetlink message handler, "
197 		      "protocol = %d, message type = %d\n",
198 		      protocol, msgtype);
199 }
200 EXPORT_SYMBOL_GPL(rtnl_register);
201 
202 /**
203  * rtnl_unregister - Unregister a rtnetlink message type
204  * @protocol: Protocol family or PF_UNSPEC
205  * @msgtype: rtnetlink message type
206  *
207  * Returns 0 on success or a negative error code.
208  */
209 int rtnl_unregister(int protocol, int msgtype)
210 {
211 	int msgindex;
212 
213 	BUG_ON(protocol < 0 || protocol >= NPROTO);
214 	msgindex = rtm_msgindex(msgtype);
215 
216 	if (rtnl_msg_handlers[protocol] == NULL)
217 		return -ENOENT;
218 
219 	rtnl_msg_handlers[protocol][msgindex].doit = NULL;
220 	rtnl_msg_handlers[protocol][msgindex].dumpit = NULL;
221 
222 	return 0;
223 }
224 EXPORT_SYMBOL_GPL(rtnl_unregister);
225 
226 /**
227  * rtnl_unregister_all - Unregister all rtnetlink message type of a protocol
228  * @protocol : Protocol family or PF_UNSPEC
229  *
230  * Identical to calling rtnl_unregster() for all registered message types
231  * of a certain protocol family.
232  */
233 void rtnl_unregister_all(int protocol)
234 {
235 	BUG_ON(protocol < 0 || protocol >= NPROTO);
236 
237 	kfree(rtnl_msg_handlers[protocol]);
238 	rtnl_msg_handlers[protocol] = NULL;
239 }
240 EXPORT_SYMBOL_GPL(rtnl_unregister_all);
241 
242 static LIST_HEAD(link_ops);
243 
244 /**
245  * __rtnl_link_register - Register rtnl_link_ops with rtnetlink.
246  * @ops: struct rtnl_link_ops * to register
247  *
248  * The caller must hold the rtnl_mutex. This function should be used
249  * by drivers that create devices during module initialization. It
250  * must be called before registering the devices.
251  *
252  * Returns 0 on success or a negative error code.
253  */
254 int __rtnl_link_register(struct rtnl_link_ops *ops)
255 {
256 	if (!ops->dellink)
257 		ops->dellink = unregister_netdevice_queue;
258 
259 	list_add_tail(&ops->list, &link_ops);
260 	return 0;
261 }
262 EXPORT_SYMBOL_GPL(__rtnl_link_register);
263 
264 /**
265  * rtnl_link_register - Register rtnl_link_ops with rtnetlink.
266  * @ops: struct rtnl_link_ops * to register
267  *
268  * Returns 0 on success or a negative error code.
269  */
270 int rtnl_link_register(struct rtnl_link_ops *ops)
271 {
272 	int err;
273 
274 	rtnl_lock();
275 	err = __rtnl_link_register(ops);
276 	rtnl_unlock();
277 	return err;
278 }
279 EXPORT_SYMBOL_GPL(rtnl_link_register);
280 
281 static void __rtnl_kill_links(struct net *net, struct rtnl_link_ops *ops)
282 {
283 	struct net_device *dev;
284 	LIST_HEAD(list_kill);
285 
286 	for_each_netdev(net, dev) {
287 		if (dev->rtnl_link_ops == ops)
288 			ops->dellink(dev, &list_kill);
289 	}
290 	unregister_netdevice_many(&list_kill);
291 }
292 
293 void rtnl_kill_links(struct net *net, struct rtnl_link_ops *ops)
294 {
295 	rtnl_lock();
296 	__rtnl_kill_links(net, ops);
297 	rtnl_unlock();
298 }
299 EXPORT_SYMBOL_GPL(rtnl_kill_links);
300 
301 /**
302  * __rtnl_link_unregister - Unregister rtnl_link_ops from rtnetlink.
303  * @ops: struct rtnl_link_ops * to unregister
304  *
305  * The caller must hold the rtnl_mutex.
306  */
307 void __rtnl_link_unregister(struct rtnl_link_ops *ops)
308 {
309 	struct net *net;
310 
311 	for_each_net(net) {
312 		__rtnl_kill_links(net, ops);
313 	}
314 	list_del(&ops->list);
315 }
316 EXPORT_SYMBOL_GPL(__rtnl_link_unregister);
317 
318 /**
319  * rtnl_link_unregister - Unregister rtnl_link_ops from rtnetlink.
320  * @ops: struct rtnl_link_ops * to unregister
321  */
322 void rtnl_link_unregister(struct rtnl_link_ops *ops)
323 {
324 	rtnl_lock();
325 	__rtnl_link_unregister(ops);
326 	rtnl_unlock();
327 }
328 EXPORT_SYMBOL_GPL(rtnl_link_unregister);
329 
330 static const struct rtnl_link_ops *rtnl_link_ops_get(const char *kind)
331 {
332 	const struct rtnl_link_ops *ops;
333 
334 	list_for_each_entry(ops, &link_ops, list) {
335 		if (!strcmp(ops->kind, kind))
336 			return ops;
337 	}
338 	return NULL;
339 }
340 
341 static size_t rtnl_link_get_size(const struct net_device *dev)
342 {
343 	const struct rtnl_link_ops *ops = dev->rtnl_link_ops;
344 	size_t size;
345 
346 	if (!ops)
347 		return 0;
348 
349 	size = nlmsg_total_size(sizeof(struct nlattr)) + /* IFLA_LINKINFO */
350 	       nlmsg_total_size(strlen(ops->kind) + 1);	 /* IFLA_INFO_KIND */
351 
352 	if (ops->get_size)
353 		/* IFLA_INFO_DATA + nested data */
354 		size += nlmsg_total_size(sizeof(struct nlattr)) +
355 			ops->get_size(dev);
356 
357 	if (ops->get_xstats_size)
358 		size += ops->get_xstats_size(dev);	/* IFLA_INFO_XSTATS */
359 
360 	return size;
361 }
362 
363 static int rtnl_link_fill(struct sk_buff *skb, const struct net_device *dev)
364 {
365 	const struct rtnl_link_ops *ops = dev->rtnl_link_ops;
366 	struct nlattr *linkinfo, *data;
367 	int err = -EMSGSIZE;
368 
369 	linkinfo = nla_nest_start(skb, IFLA_LINKINFO);
370 	if (linkinfo == NULL)
371 		goto out;
372 
373 	if (nla_put_string(skb, IFLA_INFO_KIND, ops->kind) < 0)
374 		goto err_cancel_link;
375 	if (ops->fill_xstats) {
376 		err = ops->fill_xstats(skb, dev);
377 		if (err < 0)
378 			goto err_cancel_link;
379 	}
380 	if (ops->fill_info) {
381 		data = nla_nest_start(skb, IFLA_INFO_DATA);
382 		if (data == NULL)
383 			goto err_cancel_link;
384 		err = ops->fill_info(skb, dev);
385 		if (err < 0)
386 			goto err_cancel_data;
387 		nla_nest_end(skb, data);
388 	}
389 
390 	nla_nest_end(skb, linkinfo);
391 	return 0;
392 
393 err_cancel_data:
394 	nla_nest_cancel(skb, data);
395 err_cancel_link:
396 	nla_nest_cancel(skb, linkinfo);
397 out:
398 	return err;
399 }
400 
401 static const int rtm_min[RTM_NR_FAMILIES] =
402 {
403 	[RTM_FAM(RTM_NEWLINK)]      = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
404 	[RTM_FAM(RTM_NEWADDR)]      = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
405 	[RTM_FAM(RTM_NEWROUTE)]     = NLMSG_LENGTH(sizeof(struct rtmsg)),
406 	[RTM_FAM(RTM_NEWRULE)]      = NLMSG_LENGTH(sizeof(struct fib_rule_hdr)),
407 	[RTM_FAM(RTM_NEWQDISC)]     = NLMSG_LENGTH(sizeof(struct tcmsg)),
408 	[RTM_FAM(RTM_NEWTCLASS)]    = NLMSG_LENGTH(sizeof(struct tcmsg)),
409 	[RTM_FAM(RTM_NEWTFILTER)]   = NLMSG_LENGTH(sizeof(struct tcmsg)),
410 	[RTM_FAM(RTM_NEWACTION)]    = NLMSG_LENGTH(sizeof(struct tcamsg)),
411 	[RTM_FAM(RTM_GETMULTICAST)] = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
412 	[RTM_FAM(RTM_GETANYCAST)]   = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
413 };
414 
415 static const int rta_max[RTM_NR_FAMILIES] =
416 {
417 	[RTM_FAM(RTM_NEWLINK)]      = IFLA_MAX,
418 	[RTM_FAM(RTM_NEWADDR)]      = IFA_MAX,
419 	[RTM_FAM(RTM_NEWROUTE)]     = RTA_MAX,
420 	[RTM_FAM(RTM_NEWRULE)]      = FRA_MAX,
421 	[RTM_FAM(RTM_NEWQDISC)]     = TCA_MAX,
422 	[RTM_FAM(RTM_NEWTCLASS)]    = TCA_MAX,
423 	[RTM_FAM(RTM_NEWTFILTER)]   = TCA_MAX,
424 	[RTM_FAM(RTM_NEWACTION)]    = TCAA_MAX,
425 };
426 
427 void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
428 {
429 	struct rtattr *rta;
430 	int size = RTA_LENGTH(attrlen);
431 
432 	rta = (struct rtattr *)skb_put(skb, RTA_ALIGN(size));
433 	rta->rta_type = attrtype;
434 	rta->rta_len = size;
435 	memcpy(RTA_DATA(rta), data, attrlen);
436 	memset(RTA_DATA(rta) + attrlen, 0, RTA_ALIGN(size) - size);
437 }
438 EXPORT_SYMBOL(__rta_fill);
439 
440 int rtnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, unsigned group, int echo)
441 {
442 	struct sock *rtnl = net->rtnl;
443 	int err = 0;
444 
445 	NETLINK_CB(skb).dst_group = group;
446 	if (echo)
447 		atomic_inc(&skb->users);
448 	netlink_broadcast(rtnl, skb, pid, group, GFP_KERNEL);
449 	if (echo)
450 		err = netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
451 	return err;
452 }
453 
454 int rtnl_unicast(struct sk_buff *skb, struct net *net, u32 pid)
455 {
456 	struct sock *rtnl = net->rtnl;
457 
458 	return nlmsg_unicast(rtnl, skb, pid);
459 }
460 EXPORT_SYMBOL(rtnl_unicast);
461 
462 void rtnl_notify(struct sk_buff *skb, struct net *net, u32 pid, u32 group,
463 		 struct nlmsghdr *nlh, gfp_t flags)
464 {
465 	struct sock *rtnl = net->rtnl;
466 	int report = 0;
467 
468 	if (nlh)
469 		report = nlmsg_report(nlh);
470 
471 	nlmsg_notify(rtnl, skb, pid, group, report, flags);
472 }
473 EXPORT_SYMBOL(rtnl_notify);
474 
475 void rtnl_set_sk_err(struct net *net, u32 group, int error)
476 {
477 	struct sock *rtnl = net->rtnl;
478 
479 	netlink_set_err(rtnl, 0, group, error);
480 }
481 EXPORT_SYMBOL(rtnl_set_sk_err);
482 
483 int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics)
484 {
485 	struct nlattr *mx;
486 	int i, valid = 0;
487 
488 	mx = nla_nest_start(skb, RTA_METRICS);
489 	if (mx == NULL)
490 		return -ENOBUFS;
491 
492 	for (i = 0; i < RTAX_MAX; i++) {
493 		if (metrics[i]) {
494 			valid++;
495 			NLA_PUT_U32(skb, i+1, metrics[i]);
496 		}
497 	}
498 
499 	if (!valid) {
500 		nla_nest_cancel(skb, mx);
501 		return 0;
502 	}
503 
504 	return nla_nest_end(skb, mx);
505 
506 nla_put_failure:
507 	nla_nest_cancel(skb, mx);
508 	return -EMSGSIZE;
509 }
510 EXPORT_SYMBOL(rtnetlink_put_metrics);
511 
512 int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id,
513 		       u32 ts, u32 tsage, long expires, u32 error)
514 {
515 	struct rta_cacheinfo ci = {
516 		.rta_lastuse = jiffies_to_clock_t(jiffies - dst->lastuse),
517 		.rta_used = dst->__use,
518 		.rta_clntref = atomic_read(&(dst->__refcnt)),
519 		.rta_error = error,
520 		.rta_id =  id,
521 		.rta_ts = ts,
522 		.rta_tsage = tsage,
523 	};
524 
525 	if (expires)
526 		ci.rta_expires = jiffies_to_clock_t(expires);
527 
528 	return nla_put(skb, RTA_CACHEINFO, sizeof(ci), &ci);
529 }
530 EXPORT_SYMBOL_GPL(rtnl_put_cacheinfo);
531 
532 static void set_operstate(struct net_device *dev, unsigned char transition)
533 {
534 	unsigned char operstate = dev->operstate;
535 
536 	switch (transition) {
537 	case IF_OPER_UP:
538 		if ((operstate == IF_OPER_DORMANT ||
539 		     operstate == IF_OPER_UNKNOWN) &&
540 		    !netif_dormant(dev))
541 			operstate = IF_OPER_UP;
542 		break;
543 
544 	case IF_OPER_DORMANT:
545 		if (operstate == IF_OPER_UP ||
546 		    operstate == IF_OPER_UNKNOWN)
547 			operstate = IF_OPER_DORMANT;
548 		break;
549 	}
550 
551 	if (dev->operstate != operstate) {
552 		write_lock_bh(&dev_base_lock);
553 		dev->operstate = operstate;
554 		write_unlock_bh(&dev_base_lock);
555 		netdev_state_change(dev);
556 	}
557 }
558 
559 static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
560 				 const struct net_device_stats *b)
561 {
562 	a->rx_packets = b->rx_packets;
563 	a->tx_packets = b->tx_packets;
564 	a->rx_bytes = b->rx_bytes;
565 	a->tx_bytes = b->tx_bytes;
566 	a->rx_errors = b->rx_errors;
567 	a->tx_errors = b->tx_errors;
568 	a->rx_dropped = b->rx_dropped;
569 	a->tx_dropped = b->tx_dropped;
570 
571 	a->multicast = b->multicast;
572 	a->collisions = b->collisions;
573 
574 	a->rx_length_errors = b->rx_length_errors;
575 	a->rx_over_errors = b->rx_over_errors;
576 	a->rx_crc_errors = b->rx_crc_errors;
577 	a->rx_frame_errors = b->rx_frame_errors;
578 	a->rx_fifo_errors = b->rx_fifo_errors;
579 	a->rx_missed_errors = b->rx_missed_errors;
580 
581 	a->tx_aborted_errors = b->tx_aborted_errors;
582 	a->tx_carrier_errors = b->tx_carrier_errors;
583 	a->tx_fifo_errors = b->tx_fifo_errors;
584 	a->tx_heartbeat_errors = b->tx_heartbeat_errors;
585 	a->tx_window_errors = b->tx_window_errors;
586 
587 	a->rx_compressed = b->rx_compressed;
588 	a->tx_compressed = b->tx_compressed;
589 };
590 
591 static inline size_t if_nlmsg_size(const struct net_device *dev)
592 {
593 	return NLMSG_ALIGN(sizeof(struct ifinfomsg))
594 	       + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
595 	       + nla_total_size(IFALIASZ) /* IFLA_IFALIAS */
596 	       + nla_total_size(IFNAMSIZ) /* IFLA_QDISC */
597 	       + nla_total_size(sizeof(struct rtnl_link_ifmap))
598 	       + nla_total_size(sizeof(struct rtnl_link_stats))
599 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
600 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_BROADCAST */
601 	       + nla_total_size(4) /* IFLA_TXQLEN */
602 	       + nla_total_size(4) /* IFLA_WEIGHT */
603 	       + nla_total_size(4) /* IFLA_MTU */
604 	       + nla_total_size(4) /* IFLA_LINK */
605 	       + nla_total_size(4) /* IFLA_MASTER */
606 	       + nla_total_size(1) /* IFLA_OPERSTATE */
607 	       + nla_total_size(1) /* IFLA_LINKMODE */
608 	       + rtnl_link_get_size(dev); /* IFLA_LINKINFO */
609 }
610 
611 static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
612 			    int type, u32 pid, u32 seq, u32 change,
613 			    unsigned int flags)
614 {
615 	struct ifinfomsg *ifm;
616 	struct nlmsghdr *nlh;
617 	const struct net_device_stats *stats;
618 	struct nlattr *attr;
619 
620 	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ifm), flags);
621 	if (nlh == NULL)
622 		return -EMSGSIZE;
623 
624 	ifm = nlmsg_data(nlh);
625 	ifm->ifi_family = AF_UNSPEC;
626 	ifm->__ifi_pad = 0;
627 	ifm->ifi_type = dev->type;
628 	ifm->ifi_index = dev->ifindex;
629 	ifm->ifi_flags = dev_get_flags(dev);
630 	ifm->ifi_change = change;
631 
632 	NLA_PUT_STRING(skb, IFLA_IFNAME, dev->name);
633 	NLA_PUT_U32(skb, IFLA_TXQLEN, dev->tx_queue_len);
634 	NLA_PUT_U8(skb, IFLA_OPERSTATE,
635 		   netif_running(dev) ? dev->operstate : IF_OPER_DOWN);
636 	NLA_PUT_U8(skb, IFLA_LINKMODE, dev->link_mode);
637 	NLA_PUT_U32(skb, IFLA_MTU, dev->mtu);
638 
639 	if (dev->ifindex != dev->iflink)
640 		NLA_PUT_U32(skb, IFLA_LINK, dev->iflink);
641 
642 	if (dev->master)
643 		NLA_PUT_U32(skb, IFLA_MASTER, dev->master->ifindex);
644 
645 	if (dev->qdisc)
646 		NLA_PUT_STRING(skb, IFLA_QDISC, dev->qdisc->ops->id);
647 
648 	if (dev->ifalias)
649 		NLA_PUT_STRING(skb, IFLA_IFALIAS, dev->ifalias);
650 
651 	if (1) {
652 		struct rtnl_link_ifmap map = {
653 			.mem_start   = dev->mem_start,
654 			.mem_end     = dev->mem_end,
655 			.base_addr   = dev->base_addr,
656 			.irq         = dev->irq,
657 			.dma         = dev->dma,
658 			.port        = dev->if_port,
659 		};
660 		NLA_PUT(skb, IFLA_MAP, sizeof(map), &map);
661 	}
662 
663 	if (dev->addr_len) {
664 		NLA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr);
665 		NLA_PUT(skb, IFLA_BROADCAST, dev->addr_len, dev->broadcast);
666 	}
667 
668 	attr = nla_reserve(skb, IFLA_STATS,
669 			sizeof(struct rtnl_link_stats));
670 	if (attr == NULL)
671 		goto nla_put_failure;
672 
673 	stats = dev_get_stats(dev);
674 	copy_rtnl_link_stats(nla_data(attr), stats);
675 
676 	if (dev->rtnl_link_ops) {
677 		if (rtnl_link_fill(skb, dev) < 0)
678 			goto nla_put_failure;
679 	}
680 
681 	return nlmsg_end(skb, nlh);
682 
683 nla_put_failure:
684 	nlmsg_cancel(skb, nlh);
685 	return -EMSGSIZE;
686 }
687 
688 static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
689 {
690 	struct net *net = sock_net(skb->sk);
691 	int h, s_h;
692 	int idx = 0, s_idx;
693 	struct net_device *dev;
694 	struct hlist_head *head;
695 	struct hlist_node *node;
696 
697 	s_h = cb->args[0];
698 	s_idx = cb->args[1];
699 
700 	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
701 		idx = 0;
702 		head = &net->dev_index_head[h];
703 		hlist_for_each_entry(dev, node, head, index_hlist) {
704 			if (idx < s_idx)
705 				goto cont;
706 			if (rtnl_fill_ifinfo(skb, dev, RTM_NEWLINK,
707 					     NETLINK_CB(cb->skb).pid,
708 					     cb->nlh->nlmsg_seq, 0,
709 					     NLM_F_MULTI) <= 0)
710 				goto out;
711 cont:
712 			idx++;
713 		}
714 	}
715 out:
716 	cb->args[1] = idx;
717 	cb->args[0] = h;
718 
719 	return skb->len;
720 }
721 
722 const struct nla_policy ifla_policy[IFLA_MAX+1] = {
723 	[IFLA_IFNAME]		= { .type = NLA_STRING, .len = IFNAMSIZ-1 },
724 	[IFLA_ADDRESS]		= { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
725 	[IFLA_BROADCAST]	= { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
726 	[IFLA_MAP]		= { .len = sizeof(struct rtnl_link_ifmap) },
727 	[IFLA_MTU]		= { .type = NLA_U32 },
728 	[IFLA_LINK]		= { .type = NLA_U32 },
729 	[IFLA_TXQLEN]		= { .type = NLA_U32 },
730 	[IFLA_WEIGHT]		= { .type = NLA_U32 },
731 	[IFLA_OPERSTATE]	= { .type = NLA_U8 },
732 	[IFLA_LINKMODE]		= { .type = NLA_U8 },
733 	[IFLA_LINKINFO]		= { .type = NLA_NESTED },
734 	[IFLA_NET_NS_PID]	= { .type = NLA_U32 },
735 	[IFLA_IFALIAS]	        = { .type = NLA_STRING, .len = IFALIASZ-1 },
736 };
737 EXPORT_SYMBOL(ifla_policy);
738 
739 static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
740 	[IFLA_INFO_KIND]	= { .type = NLA_STRING },
741 	[IFLA_INFO_DATA]	= { .type = NLA_NESTED },
742 };
743 
744 struct net *rtnl_link_get_net(struct net *src_net, struct nlattr *tb[])
745 {
746 	struct net *net;
747 	/* Examine the link attributes and figure out which
748 	 * network namespace we are talking about.
749 	 */
750 	if (tb[IFLA_NET_NS_PID])
751 		net = get_net_ns_by_pid(nla_get_u32(tb[IFLA_NET_NS_PID]));
752 	else
753 		net = get_net(src_net);
754 	return net;
755 }
756 EXPORT_SYMBOL(rtnl_link_get_net);
757 
758 static int validate_linkmsg(struct net_device *dev, struct nlattr *tb[])
759 {
760 	if (dev) {
761 		if (tb[IFLA_ADDRESS] &&
762 		    nla_len(tb[IFLA_ADDRESS]) < dev->addr_len)
763 			return -EINVAL;
764 
765 		if (tb[IFLA_BROADCAST] &&
766 		    nla_len(tb[IFLA_BROADCAST]) < dev->addr_len)
767 			return -EINVAL;
768 	}
769 
770 	return 0;
771 }
772 
773 static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
774 		      struct nlattr **tb, char *ifname, int modified)
775 {
776 	const struct net_device_ops *ops = dev->netdev_ops;
777 	int send_addr_notify = 0;
778 	int err;
779 
780 	if (tb[IFLA_NET_NS_PID]) {
781 		struct net *net = rtnl_link_get_net(dev_net(dev), tb);
782 		if (IS_ERR(net)) {
783 			err = PTR_ERR(net);
784 			goto errout;
785 		}
786 		err = dev_change_net_namespace(dev, net, ifname);
787 		put_net(net);
788 		if (err)
789 			goto errout;
790 		modified = 1;
791 	}
792 
793 	if (tb[IFLA_MAP]) {
794 		struct rtnl_link_ifmap *u_map;
795 		struct ifmap k_map;
796 
797 		if (!ops->ndo_set_config) {
798 			err = -EOPNOTSUPP;
799 			goto errout;
800 		}
801 
802 		if (!netif_device_present(dev)) {
803 			err = -ENODEV;
804 			goto errout;
805 		}
806 
807 		u_map = nla_data(tb[IFLA_MAP]);
808 		k_map.mem_start = (unsigned long) u_map->mem_start;
809 		k_map.mem_end = (unsigned long) u_map->mem_end;
810 		k_map.base_addr = (unsigned short) u_map->base_addr;
811 		k_map.irq = (unsigned char) u_map->irq;
812 		k_map.dma = (unsigned char) u_map->dma;
813 		k_map.port = (unsigned char) u_map->port;
814 
815 		err = ops->ndo_set_config(dev, &k_map);
816 		if (err < 0)
817 			goto errout;
818 
819 		modified = 1;
820 	}
821 
822 	if (tb[IFLA_ADDRESS]) {
823 		struct sockaddr *sa;
824 		int len;
825 
826 		if (!ops->ndo_set_mac_address) {
827 			err = -EOPNOTSUPP;
828 			goto errout;
829 		}
830 
831 		if (!netif_device_present(dev)) {
832 			err = -ENODEV;
833 			goto errout;
834 		}
835 
836 		len = sizeof(sa_family_t) + dev->addr_len;
837 		sa = kmalloc(len, GFP_KERNEL);
838 		if (!sa) {
839 			err = -ENOMEM;
840 			goto errout;
841 		}
842 		sa->sa_family = dev->type;
843 		memcpy(sa->sa_data, nla_data(tb[IFLA_ADDRESS]),
844 		       dev->addr_len);
845 		err = ops->ndo_set_mac_address(dev, sa);
846 		kfree(sa);
847 		if (err)
848 			goto errout;
849 		send_addr_notify = 1;
850 		modified = 1;
851 	}
852 
853 	if (tb[IFLA_MTU]) {
854 		err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
855 		if (err < 0)
856 			goto errout;
857 		modified = 1;
858 	}
859 
860 	/*
861 	 * Interface selected by interface index but interface
862 	 * name provided implies that a name change has been
863 	 * requested.
864 	 */
865 	if (ifm->ifi_index > 0 && ifname[0]) {
866 		err = dev_change_name(dev, ifname);
867 		if (err < 0)
868 			goto errout;
869 		modified = 1;
870 	}
871 
872 	if (tb[IFLA_IFALIAS]) {
873 		err = dev_set_alias(dev, nla_data(tb[IFLA_IFALIAS]),
874 				    nla_len(tb[IFLA_IFALIAS]));
875 		if (err < 0)
876 			goto errout;
877 		modified = 1;
878 	}
879 
880 	if (tb[IFLA_BROADCAST]) {
881 		nla_memcpy(dev->broadcast, tb[IFLA_BROADCAST], dev->addr_len);
882 		send_addr_notify = 1;
883 	}
884 
885 	if (ifm->ifi_flags || ifm->ifi_change) {
886 		unsigned int flags = ifm->ifi_flags;
887 
888 		/* bugwards compatibility: ifi_change == 0 is treated as ~0 */
889 		if (ifm->ifi_change)
890 			flags = (flags & ifm->ifi_change) |
891 				(dev->flags & ~ifm->ifi_change);
892 		err = dev_change_flags(dev, flags);
893 		if (err < 0)
894 			goto errout;
895 	}
896 
897 	if (tb[IFLA_TXQLEN])
898 		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
899 
900 	if (tb[IFLA_OPERSTATE])
901 		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
902 
903 	if (tb[IFLA_LINKMODE]) {
904 		write_lock_bh(&dev_base_lock);
905 		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
906 		write_unlock_bh(&dev_base_lock);
907 	}
908 
909 	err = 0;
910 
911 errout:
912 	if (err < 0 && modified && net_ratelimit())
913 		printk(KERN_WARNING "A link change request failed with "
914 		       "some changes comitted already. Interface %s may "
915 		       "have been left with an inconsistent configuration, "
916 		       "please check.\n", dev->name);
917 
918 	if (send_addr_notify)
919 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
920 	return err;
921 }
922 
923 static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
924 {
925 	struct net *net = sock_net(skb->sk);
926 	struct ifinfomsg *ifm;
927 	struct net_device *dev;
928 	int err;
929 	struct nlattr *tb[IFLA_MAX+1];
930 	char ifname[IFNAMSIZ];
931 
932 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
933 	if (err < 0)
934 		goto errout;
935 
936 	if (tb[IFLA_IFNAME])
937 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
938 	else
939 		ifname[0] = '\0';
940 
941 	err = -EINVAL;
942 	ifm = nlmsg_data(nlh);
943 	if (ifm->ifi_index > 0)
944 		dev = __dev_get_by_index(net, ifm->ifi_index);
945 	else if (tb[IFLA_IFNAME])
946 		dev = __dev_get_by_name(net, ifname);
947 	else
948 		goto errout;
949 
950 	if (dev == NULL) {
951 		err = -ENODEV;
952 		goto errout;
953 	}
954 
955 	err = validate_linkmsg(dev, tb);
956 	if (err < 0)
957 		goto errout;
958 
959 	err = do_setlink(dev, ifm, tb, ifname, 0);
960 errout:
961 	return err;
962 }
963 
964 static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
965 {
966 	struct net *net = sock_net(skb->sk);
967 	const struct rtnl_link_ops *ops;
968 	struct net_device *dev;
969 	struct ifinfomsg *ifm;
970 	char ifname[IFNAMSIZ];
971 	struct nlattr *tb[IFLA_MAX+1];
972 	int err;
973 
974 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
975 	if (err < 0)
976 		return err;
977 
978 	if (tb[IFLA_IFNAME])
979 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
980 
981 	ifm = nlmsg_data(nlh);
982 	if (ifm->ifi_index > 0)
983 		dev = __dev_get_by_index(net, ifm->ifi_index);
984 	else if (tb[IFLA_IFNAME])
985 		dev = __dev_get_by_name(net, ifname);
986 	else
987 		return -EINVAL;
988 
989 	if (!dev)
990 		return -ENODEV;
991 
992 	ops = dev->rtnl_link_ops;
993 	if (!ops)
994 		return -EOPNOTSUPP;
995 
996 	ops->dellink(dev, NULL);
997 	return 0;
998 }
999 
1000 struct net_device *rtnl_create_link(struct net *src_net, struct net *net,
1001 	char *ifname, const struct rtnl_link_ops *ops, struct nlattr *tb[])
1002 {
1003 	int err;
1004 	struct net_device *dev;
1005 	unsigned int num_queues = 1;
1006 	unsigned int real_num_queues = 1;
1007 
1008 	if (ops->get_tx_queues) {
1009 		err = ops->get_tx_queues(src_net, tb, &num_queues,
1010 					 &real_num_queues);
1011 		if (err)
1012 			goto err;
1013 	}
1014 	err = -ENOMEM;
1015 	dev = alloc_netdev_mq(ops->priv_size, ifname, ops->setup, num_queues);
1016 	if (!dev)
1017 		goto err;
1018 
1019 	dev_net_set(dev, net);
1020 	dev->rtnl_link_ops = ops;
1021 	dev->real_num_tx_queues = real_num_queues;
1022 
1023 	if (strchr(dev->name, '%')) {
1024 		err = dev_alloc_name(dev, dev->name);
1025 		if (err < 0)
1026 			goto err_free;
1027 	}
1028 
1029 	if (tb[IFLA_MTU])
1030 		dev->mtu = nla_get_u32(tb[IFLA_MTU]);
1031 	if (tb[IFLA_ADDRESS])
1032 		memcpy(dev->dev_addr, nla_data(tb[IFLA_ADDRESS]),
1033 				nla_len(tb[IFLA_ADDRESS]));
1034 	if (tb[IFLA_BROADCAST])
1035 		memcpy(dev->broadcast, nla_data(tb[IFLA_BROADCAST]),
1036 				nla_len(tb[IFLA_BROADCAST]));
1037 	if (tb[IFLA_TXQLEN])
1038 		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
1039 	if (tb[IFLA_OPERSTATE])
1040 		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
1041 	if (tb[IFLA_LINKMODE])
1042 		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
1043 
1044 	return dev;
1045 
1046 err_free:
1047 	free_netdev(dev);
1048 err:
1049 	return ERR_PTR(err);
1050 }
1051 EXPORT_SYMBOL(rtnl_create_link);
1052 
1053 static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
1054 {
1055 	struct net *net = sock_net(skb->sk);
1056 	const struct rtnl_link_ops *ops;
1057 	struct net_device *dev;
1058 	struct ifinfomsg *ifm;
1059 	char kind[MODULE_NAME_LEN];
1060 	char ifname[IFNAMSIZ];
1061 	struct nlattr *tb[IFLA_MAX+1];
1062 	struct nlattr *linkinfo[IFLA_INFO_MAX+1];
1063 	int err;
1064 
1065 #ifdef CONFIG_MODULES
1066 replay:
1067 #endif
1068 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
1069 	if (err < 0)
1070 		return err;
1071 
1072 	if (tb[IFLA_IFNAME])
1073 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
1074 	else
1075 		ifname[0] = '\0';
1076 
1077 	ifm = nlmsg_data(nlh);
1078 	if (ifm->ifi_index > 0)
1079 		dev = __dev_get_by_index(net, ifm->ifi_index);
1080 	else if (ifname[0])
1081 		dev = __dev_get_by_name(net, ifname);
1082 	else
1083 		dev = NULL;
1084 
1085 	err = validate_linkmsg(dev, tb);
1086 	if (err < 0)
1087 		return err;
1088 
1089 	if (tb[IFLA_LINKINFO]) {
1090 		err = nla_parse_nested(linkinfo, IFLA_INFO_MAX,
1091 				       tb[IFLA_LINKINFO], ifla_info_policy);
1092 		if (err < 0)
1093 			return err;
1094 	} else
1095 		memset(linkinfo, 0, sizeof(linkinfo));
1096 
1097 	if (linkinfo[IFLA_INFO_KIND]) {
1098 		nla_strlcpy(kind, linkinfo[IFLA_INFO_KIND], sizeof(kind));
1099 		ops = rtnl_link_ops_get(kind);
1100 	} else {
1101 		kind[0] = '\0';
1102 		ops = NULL;
1103 	}
1104 
1105 	if (1) {
1106 		struct nlattr *attr[ops ? ops->maxtype + 1 : 0], **data = NULL;
1107 		struct net *dest_net;
1108 
1109 		if (ops) {
1110 			if (ops->maxtype && linkinfo[IFLA_INFO_DATA]) {
1111 				err = nla_parse_nested(attr, ops->maxtype,
1112 						       linkinfo[IFLA_INFO_DATA],
1113 						       ops->policy);
1114 				if (err < 0)
1115 					return err;
1116 				data = attr;
1117 			}
1118 			if (ops->validate) {
1119 				err = ops->validate(tb, data);
1120 				if (err < 0)
1121 					return err;
1122 			}
1123 		}
1124 
1125 		if (dev) {
1126 			int modified = 0;
1127 
1128 			if (nlh->nlmsg_flags & NLM_F_EXCL)
1129 				return -EEXIST;
1130 			if (nlh->nlmsg_flags & NLM_F_REPLACE)
1131 				return -EOPNOTSUPP;
1132 
1133 			if (linkinfo[IFLA_INFO_DATA]) {
1134 				if (!ops || ops != dev->rtnl_link_ops ||
1135 				    !ops->changelink)
1136 					return -EOPNOTSUPP;
1137 
1138 				err = ops->changelink(dev, tb, data);
1139 				if (err < 0)
1140 					return err;
1141 				modified = 1;
1142 			}
1143 
1144 			return do_setlink(dev, ifm, tb, ifname, modified);
1145 		}
1146 
1147 		if (!(nlh->nlmsg_flags & NLM_F_CREATE))
1148 			return -ENODEV;
1149 
1150 		if (ifm->ifi_index || ifm->ifi_flags || ifm->ifi_change)
1151 			return -EOPNOTSUPP;
1152 		if (tb[IFLA_MAP] || tb[IFLA_MASTER] || tb[IFLA_PROTINFO])
1153 			return -EOPNOTSUPP;
1154 
1155 		if (!ops) {
1156 #ifdef CONFIG_MODULES
1157 			if (kind[0]) {
1158 				__rtnl_unlock();
1159 				request_module("rtnl-link-%s", kind);
1160 				rtnl_lock();
1161 				ops = rtnl_link_ops_get(kind);
1162 				if (ops)
1163 					goto replay;
1164 			}
1165 #endif
1166 			return -EOPNOTSUPP;
1167 		}
1168 
1169 		if (!ifname[0])
1170 			snprintf(ifname, IFNAMSIZ, "%s%%d", ops->kind);
1171 
1172 		dest_net = rtnl_link_get_net(net, tb);
1173 		dev = rtnl_create_link(net, dest_net, ifname, ops, tb);
1174 
1175 		if (IS_ERR(dev))
1176 			err = PTR_ERR(dev);
1177 		else if (ops->newlink)
1178 			err = ops->newlink(net, dev, tb, data);
1179 		else
1180 			err = register_netdevice(dev);
1181 		if (err < 0 && !IS_ERR(dev))
1182 			free_netdev(dev);
1183 
1184 		put_net(dest_net);
1185 		return err;
1186 	}
1187 }
1188 
1189 static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
1190 {
1191 	struct net *net = sock_net(skb->sk);
1192 	struct ifinfomsg *ifm;
1193 	char ifname[IFNAMSIZ];
1194 	struct nlattr *tb[IFLA_MAX+1];
1195 	struct net_device *dev = NULL;
1196 	struct sk_buff *nskb;
1197 	int err;
1198 
1199 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
1200 	if (err < 0)
1201 		return err;
1202 
1203 	if (tb[IFLA_IFNAME])
1204 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
1205 
1206 	ifm = nlmsg_data(nlh);
1207 	if (ifm->ifi_index > 0)
1208 		dev = __dev_get_by_index(net, ifm->ifi_index);
1209 	else if (tb[IFLA_IFNAME])
1210 		dev = __dev_get_by_name(net, ifname);
1211 	else
1212 		return -EINVAL;
1213 
1214 	if (dev == NULL)
1215 		return -ENODEV;
1216 
1217 	nskb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
1218 	if (nskb == NULL)
1219 		return -ENOBUFS;
1220 
1221 	err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).pid,
1222 			       nlh->nlmsg_seq, 0, 0);
1223 	if (err < 0) {
1224 		/* -EMSGSIZE implies BUG in if_nlmsg_size */
1225 		WARN_ON(err == -EMSGSIZE);
1226 		kfree_skb(nskb);
1227 	} else
1228 		err = rtnl_unicast(nskb, net, NETLINK_CB(skb).pid);
1229 
1230 	return err;
1231 }
1232 
1233 static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
1234 {
1235 	int idx;
1236 	int s_idx = cb->family;
1237 
1238 	if (s_idx == 0)
1239 		s_idx = 1;
1240 	for (idx = 1; idx < NPROTO; idx++) {
1241 		int type = cb->nlh->nlmsg_type-RTM_BASE;
1242 		if (idx < s_idx || idx == PF_PACKET)
1243 			continue;
1244 		if (rtnl_msg_handlers[idx] == NULL ||
1245 		    rtnl_msg_handlers[idx][type].dumpit == NULL)
1246 			continue;
1247 		if (idx > s_idx)
1248 			memset(&cb->args[0], 0, sizeof(cb->args));
1249 		if (rtnl_msg_handlers[idx][type].dumpit(skb, cb))
1250 			break;
1251 	}
1252 	cb->family = idx;
1253 
1254 	return skb->len;
1255 }
1256 
1257 void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change)
1258 {
1259 	struct net *net = dev_net(dev);
1260 	struct sk_buff *skb;
1261 	int err = -ENOBUFS;
1262 
1263 	skb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
1264 	if (skb == NULL)
1265 		goto errout;
1266 
1267 	err = rtnl_fill_ifinfo(skb, dev, type, 0, 0, change, 0);
1268 	if (err < 0) {
1269 		/* -EMSGSIZE implies BUG in if_nlmsg_size() */
1270 		WARN_ON(err == -EMSGSIZE);
1271 		kfree_skb(skb);
1272 		goto errout;
1273 	}
1274 	rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_KERNEL);
1275 	return;
1276 errout:
1277 	if (err < 0)
1278 		rtnl_set_sk_err(net, RTNLGRP_LINK, err);
1279 }
1280 
1281 /* Protected by RTNL sempahore.  */
1282 static struct rtattr **rta_buf;
1283 static int rtattr_max;
1284 
1285 /* Process one rtnetlink message. */
1286 
1287 static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
1288 {
1289 	struct net *net = sock_net(skb->sk);
1290 	rtnl_doit_func doit;
1291 	int sz_idx, kind;
1292 	int min_len;
1293 	int family;
1294 	int type;
1295 	int err;
1296 
1297 	type = nlh->nlmsg_type;
1298 	if (type > RTM_MAX)
1299 		return -EOPNOTSUPP;
1300 
1301 	type -= RTM_BASE;
1302 
1303 	/* All the messages must have at least 1 byte length */
1304 	if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct rtgenmsg)))
1305 		return 0;
1306 
1307 	family = ((struct rtgenmsg *)NLMSG_DATA(nlh))->rtgen_family;
1308 	if (family >= NPROTO)
1309 		return -EAFNOSUPPORT;
1310 
1311 	sz_idx = type>>2;
1312 	kind = type&3;
1313 
1314 	if (kind != 2 && security_netlink_recv(skb, CAP_NET_ADMIN))
1315 		return -EPERM;
1316 
1317 	if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
1318 		struct sock *rtnl;
1319 		rtnl_dumpit_func dumpit;
1320 
1321 		dumpit = rtnl_get_dumpit(family, type);
1322 		if (dumpit == NULL)
1323 			return -EOPNOTSUPP;
1324 
1325 		__rtnl_unlock();
1326 		rtnl = net->rtnl;
1327 		err = netlink_dump_start(rtnl, skb, nlh, dumpit, NULL);
1328 		rtnl_lock();
1329 		return err;
1330 	}
1331 
1332 	memset(rta_buf, 0, (rtattr_max * sizeof(struct rtattr *)));
1333 
1334 	min_len = rtm_min[sz_idx];
1335 	if (nlh->nlmsg_len < min_len)
1336 		return -EINVAL;
1337 
1338 	if (nlh->nlmsg_len > min_len) {
1339 		int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
1340 		struct rtattr *attr = (void *)nlh + NLMSG_ALIGN(min_len);
1341 
1342 		while (RTA_OK(attr, attrlen)) {
1343 			unsigned flavor = attr->rta_type;
1344 			if (flavor) {
1345 				if (flavor > rta_max[sz_idx])
1346 					return -EINVAL;
1347 				rta_buf[flavor-1] = attr;
1348 			}
1349 			attr = RTA_NEXT(attr, attrlen);
1350 		}
1351 	}
1352 
1353 	doit = rtnl_get_doit(family, type);
1354 	if (doit == NULL)
1355 		return -EOPNOTSUPP;
1356 
1357 	return doit(skb, nlh, (void *)&rta_buf[0]);
1358 }
1359 
1360 static void rtnetlink_rcv(struct sk_buff *skb)
1361 {
1362 	rtnl_lock();
1363 	netlink_rcv_skb(skb, &rtnetlink_rcv_msg);
1364 	rtnl_unlock();
1365 }
1366 
1367 static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr)
1368 {
1369 	struct net_device *dev = ptr;
1370 
1371 	switch (event) {
1372 	case NETDEV_UNREGISTER:
1373 		rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
1374 		break;
1375 	case NETDEV_UP:
1376 	case NETDEV_DOWN:
1377 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1378 		break;
1379 	case NETDEV_POST_INIT:
1380 	case NETDEV_REGISTER:
1381 	case NETDEV_CHANGE:
1382 	case NETDEV_GOING_DOWN:
1383 	case NETDEV_UNREGISTER_BATCH:
1384 		break;
1385 	default:
1386 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
1387 		break;
1388 	}
1389 	return NOTIFY_DONE;
1390 }
1391 
1392 static struct notifier_block rtnetlink_dev_notifier = {
1393 	.notifier_call	= rtnetlink_event,
1394 };
1395 
1396 
1397 static int rtnetlink_net_init(struct net *net)
1398 {
1399 	struct sock *sk;
1400 	sk = netlink_kernel_create(net, NETLINK_ROUTE, RTNLGRP_MAX,
1401 				   rtnetlink_rcv, &rtnl_mutex, THIS_MODULE);
1402 	if (!sk)
1403 		return -ENOMEM;
1404 	net->rtnl = sk;
1405 	return 0;
1406 }
1407 
1408 static void rtnetlink_net_exit(struct net *net)
1409 {
1410 	netlink_kernel_release(net->rtnl);
1411 	net->rtnl = NULL;
1412 }
1413 
1414 static struct pernet_operations rtnetlink_net_ops = {
1415 	.init = rtnetlink_net_init,
1416 	.exit = rtnetlink_net_exit,
1417 };
1418 
1419 void __init rtnetlink_init(void)
1420 {
1421 	int i;
1422 
1423 	rtattr_max = 0;
1424 	for (i = 0; i < ARRAY_SIZE(rta_max); i++)
1425 		if (rta_max[i] > rtattr_max)
1426 			rtattr_max = rta_max[i];
1427 	rta_buf = kmalloc(rtattr_max * sizeof(struct rtattr *), GFP_KERNEL);
1428 	if (!rta_buf)
1429 		panic("rtnetlink_init: cannot allocate rta_buf\n");
1430 
1431 	if (register_pernet_subsys(&rtnetlink_net_ops))
1432 		panic("rtnetlink_init: cannot initialize rtnetlink\n");
1433 
1434 	netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
1435 	register_netdevice_notifier(&rtnetlink_dev_notifier);
1436 
1437 	rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink, rtnl_dump_ifinfo);
1438 	rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL);
1439 	rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL);
1440 	rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL);
1441 
1442 	rtnl_register(PF_UNSPEC, RTM_GETADDR, NULL, rtnl_dump_all);
1443 	rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all);
1444 }
1445 
1446