xref: /openbmc/linux/net/core/rtnetlink.c (revision f42b3800)
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 #include <linux/nsproxy.h>
39 
40 #include <asm/uaccess.h>
41 #include <asm/system.h>
42 #include <asm/string.h>
43 
44 #include <linux/inet.h>
45 #include <linux/netdevice.h>
46 #include <net/ip.h>
47 #include <net/protocol.h>
48 #include <net/arp.h>
49 #include <net/route.h>
50 #include <net/udp.h>
51 #include <net/sock.h>
52 #include <net/pkt_sched.h>
53 #include <net/fib_rules.h>
54 #include <net/rtnetlink.h>
55 
56 struct rtnl_link
57 {
58 	rtnl_doit_func		doit;
59 	rtnl_dumpit_func	dumpit;
60 };
61 
62 static DEFINE_MUTEX(rtnl_mutex);
63 
64 void rtnl_lock(void)
65 {
66 	mutex_lock(&rtnl_mutex);
67 }
68 
69 void __rtnl_unlock(void)
70 {
71 	mutex_unlock(&rtnl_mutex);
72 }
73 
74 void rtnl_unlock(void)
75 {
76 	mutex_unlock(&rtnl_mutex);
77 	netdev_run_todo();
78 }
79 
80 int rtnl_trylock(void)
81 {
82 	return mutex_trylock(&rtnl_mutex);
83 }
84 
85 static struct rtnl_link *rtnl_msg_handlers[NPROTO];
86 
87 static inline int rtm_msgindex(int msgtype)
88 {
89 	int msgindex = msgtype - RTM_BASE;
90 
91 	/*
92 	 * msgindex < 0 implies someone tried to register a netlink
93 	 * control code. msgindex >= RTM_NR_MSGTYPES may indicate that
94 	 * the message type has not been added to linux/rtnetlink.h
95 	 */
96 	BUG_ON(msgindex < 0 || msgindex >= RTM_NR_MSGTYPES);
97 
98 	return msgindex;
99 }
100 
101 static rtnl_doit_func rtnl_get_doit(int protocol, int msgindex)
102 {
103 	struct rtnl_link *tab;
104 
105 	tab = rtnl_msg_handlers[protocol];
106 	if (tab == NULL || tab[msgindex].doit == NULL)
107 		tab = rtnl_msg_handlers[PF_UNSPEC];
108 
109 	return tab ? tab[msgindex].doit : NULL;
110 }
111 
112 static rtnl_dumpit_func rtnl_get_dumpit(int protocol, int msgindex)
113 {
114 	struct rtnl_link *tab;
115 
116 	tab = rtnl_msg_handlers[protocol];
117 	if (tab == NULL || tab[msgindex].dumpit == NULL)
118 		tab = rtnl_msg_handlers[PF_UNSPEC];
119 
120 	return tab ? tab[msgindex].dumpit : NULL;
121 }
122 
123 /**
124  * __rtnl_register - Register a rtnetlink message type
125  * @protocol: Protocol family or PF_UNSPEC
126  * @msgtype: rtnetlink message type
127  * @doit: Function pointer called for each request message
128  * @dumpit: Function pointer called for each dump request (NLM_F_DUMP) message
129  *
130  * Registers the specified function pointers (at least one of them has
131  * to be non-NULL) to be called whenever a request message for the
132  * specified protocol family and message type is received.
133  *
134  * The special protocol family PF_UNSPEC may be used to define fallback
135  * function pointers for the case when no entry for the specific protocol
136  * family exists.
137  *
138  * Returns 0 on success or a negative error code.
139  */
140 int __rtnl_register(int protocol, int msgtype,
141 		    rtnl_doit_func doit, rtnl_dumpit_func dumpit)
142 {
143 	struct rtnl_link *tab;
144 	int msgindex;
145 
146 	BUG_ON(protocol < 0 || protocol >= NPROTO);
147 	msgindex = rtm_msgindex(msgtype);
148 
149 	tab = rtnl_msg_handlers[protocol];
150 	if (tab == NULL) {
151 		tab = kcalloc(RTM_NR_MSGTYPES, sizeof(*tab), GFP_KERNEL);
152 		if (tab == NULL)
153 			return -ENOBUFS;
154 
155 		rtnl_msg_handlers[protocol] = tab;
156 	}
157 
158 	if (doit)
159 		tab[msgindex].doit = doit;
160 
161 	if (dumpit)
162 		tab[msgindex].dumpit = dumpit;
163 
164 	return 0;
165 }
166 
167 EXPORT_SYMBOL_GPL(__rtnl_register);
168 
169 /**
170  * rtnl_register - Register a rtnetlink message type
171  *
172  * Identical to __rtnl_register() but panics on failure. This is useful
173  * as failure of this function is very unlikely, it can only happen due
174  * to lack of memory when allocating the chain to store all message
175  * handlers for a protocol. Meant for use in init functions where lack
176  * of memory implies no sense in continueing.
177  */
178 void rtnl_register(int protocol, int msgtype,
179 		   rtnl_doit_func doit, rtnl_dumpit_func dumpit)
180 {
181 	if (__rtnl_register(protocol, msgtype, doit, dumpit) < 0)
182 		panic("Unable to register rtnetlink message handler, "
183 		      "protocol = %d, message type = %d\n",
184 		      protocol, msgtype);
185 }
186 
187 EXPORT_SYMBOL_GPL(rtnl_register);
188 
189 /**
190  * rtnl_unregister - Unregister a rtnetlink message type
191  * @protocol: Protocol family or PF_UNSPEC
192  * @msgtype: rtnetlink message type
193  *
194  * Returns 0 on success or a negative error code.
195  */
196 int rtnl_unregister(int protocol, int msgtype)
197 {
198 	int msgindex;
199 
200 	BUG_ON(protocol < 0 || protocol >= NPROTO);
201 	msgindex = rtm_msgindex(msgtype);
202 
203 	if (rtnl_msg_handlers[protocol] == NULL)
204 		return -ENOENT;
205 
206 	rtnl_msg_handlers[protocol][msgindex].doit = NULL;
207 	rtnl_msg_handlers[protocol][msgindex].dumpit = NULL;
208 
209 	return 0;
210 }
211 
212 EXPORT_SYMBOL_GPL(rtnl_unregister);
213 
214 /**
215  * rtnl_unregister_all - Unregister all rtnetlink message type of a protocol
216  * @protocol : Protocol family or PF_UNSPEC
217  *
218  * Identical to calling rtnl_unregster() for all registered message types
219  * of a certain protocol family.
220  */
221 void rtnl_unregister_all(int protocol)
222 {
223 	BUG_ON(protocol < 0 || protocol >= NPROTO);
224 
225 	kfree(rtnl_msg_handlers[protocol]);
226 	rtnl_msg_handlers[protocol] = NULL;
227 }
228 
229 EXPORT_SYMBOL_GPL(rtnl_unregister_all);
230 
231 static LIST_HEAD(link_ops);
232 
233 /**
234  * __rtnl_link_register - Register rtnl_link_ops with rtnetlink.
235  * @ops: struct rtnl_link_ops * to register
236  *
237  * The caller must hold the rtnl_mutex. This function should be used
238  * by drivers that create devices during module initialization. It
239  * must be called before registering the devices.
240  *
241  * Returns 0 on success or a negative error code.
242  */
243 int __rtnl_link_register(struct rtnl_link_ops *ops)
244 {
245 	if (!ops->dellink)
246 		ops->dellink = unregister_netdevice;
247 
248 	list_add_tail(&ops->list, &link_ops);
249 	return 0;
250 }
251 
252 EXPORT_SYMBOL_GPL(__rtnl_link_register);
253 
254 /**
255  * rtnl_link_register - Register rtnl_link_ops with rtnetlink.
256  * @ops: struct rtnl_link_ops * to register
257  *
258  * Returns 0 on success or a negative error code.
259  */
260 int rtnl_link_register(struct rtnl_link_ops *ops)
261 {
262 	int err;
263 
264 	rtnl_lock();
265 	err = __rtnl_link_register(ops);
266 	rtnl_unlock();
267 	return err;
268 }
269 
270 EXPORT_SYMBOL_GPL(rtnl_link_register);
271 
272 static void __rtnl_kill_links(struct net *net, struct rtnl_link_ops *ops)
273 {
274 	struct net_device *dev;
275 restart:
276 	for_each_netdev(net, dev) {
277 		if (dev->rtnl_link_ops == ops) {
278 			ops->dellink(dev);
279 			goto restart;
280 		}
281 	}
282 }
283 
284 void rtnl_kill_links(struct net *net, struct rtnl_link_ops *ops)
285 {
286 	rtnl_lock();
287 	__rtnl_kill_links(net, ops);
288 	rtnl_unlock();
289 }
290 EXPORT_SYMBOL_GPL(rtnl_kill_links);
291 
292 /**
293  * __rtnl_link_unregister - Unregister rtnl_link_ops from rtnetlink.
294  * @ops: struct rtnl_link_ops * to unregister
295  *
296  * The caller must hold the rtnl_mutex.
297  */
298 void __rtnl_link_unregister(struct rtnl_link_ops *ops)
299 {
300 	struct net *net;
301 
302 	for_each_net(net) {
303 		__rtnl_kill_links(net, ops);
304 	}
305 	list_del(&ops->list);
306 }
307 
308 EXPORT_SYMBOL_GPL(__rtnl_link_unregister);
309 
310 /**
311  * rtnl_link_unregister - Unregister rtnl_link_ops from rtnetlink.
312  * @ops: struct rtnl_link_ops * to unregister
313  */
314 void rtnl_link_unregister(struct rtnl_link_ops *ops)
315 {
316 	rtnl_lock();
317 	__rtnl_link_unregister(ops);
318 	rtnl_unlock();
319 }
320 
321 EXPORT_SYMBOL_GPL(rtnl_link_unregister);
322 
323 static const struct rtnl_link_ops *rtnl_link_ops_get(const char *kind)
324 {
325 	const struct rtnl_link_ops *ops;
326 
327 	list_for_each_entry(ops, &link_ops, list) {
328 		if (!strcmp(ops->kind, kind))
329 			return ops;
330 	}
331 	return NULL;
332 }
333 
334 static size_t rtnl_link_get_size(const struct net_device *dev)
335 {
336 	const struct rtnl_link_ops *ops = dev->rtnl_link_ops;
337 	size_t size;
338 
339 	if (!ops)
340 		return 0;
341 
342 	size = nlmsg_total_size(sizeof(struct nlattr)) + /* IFLA_LINKINFO */
343 	       nlmsg_total_size(strlen(ops->kind) + 1);	 /* IFLA_INFO_KIND */
344 
345 	if (ops->get_size)
346 		/* IFLA_INFO_DATA + nested data */
347 		size += nlmsg_total_size(sizeof(struct nlattr)) +
348 			ops->get_size(dev);
349 
350 	if (ops->get_xstats_size)
351 		size += ops->get_xstats_size(dev);	/* IFLA_INFO_XSTATS */
352 
353 	return size;
354 }
355 
356 static int rtnl_link_fill(struct sk_buff *skb, const struct net_device *dev)
357 {
358 	const struct rtnl_link_ops *ops = dev->rtnl_link_ops;
359 	struct nlattr *linkinfo, *data;
360 	int err = -EMSGSIZE;
361 
362 	linkinfo = nla_nest_start(skb, IFLA_LINKINFO);
363 	if (linkinfo == NULL)
364 		goto out;
365 
366 	if (nla_put_string(skb, IFLA_INFO_KIND, ops->kind) < 0)
367 		goto err_cancel_link;
368 	if (ops->fill_xstats) {
369 		err = ops->fill_xstats(skb, dev);
370 		if (err < 0)
371 			goto err_cancel_link;
372 	}
373 	if (ops->fill_info) {
374 		data = nla_nest_start(skb, IFLA_INFO_DATA);
375 		if (data == NULL)
376 			goto err_cancel_link;
377 		err = ops->fill_info(skb, dev);
378 		if (err < 0)
379 			goto err_cancel_data;
380 		nla_nest_end(skb, data);
381 	}
382 
383 	nla_nest_end(skb, linkinfo);
384 	return 0;
385 
386 err_cancel_data:
387 	nla_nest_cancel(skb, data);
388 err_cancel_link:
389 	nla_nest_cancel(skb, linkinfo);
390 out:
391 	return err;
392 }
393 
394 static const int rtm_min[RTM_NR_FAMILIES] =
395 {
396 	[RTM_FAM(RTM_NEWLINK)]      = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
397 	[RTM_FAM(RTM_NEWADDR)]      = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
398 	[RTM_FAM(RTM_NEWROUTE)]     = NLMSG_LENGTH(sizeof(struct rtmsg)),
399 	[RTM_FAM(RTM_NEWRULE)]      = NLMSG_LENGTH(sizeof(struct fib_rule_hdr)),
400 	[RTM_FAM(RTM_NEWQDISC)]     = NLMSG_LENGTH(sizeof(struct tcmsg)),
401 	[RTM_FAM(RTM_NEWTCLASS)]    = NLMSG_LENGTH(sizeof(struct tcmsg)),
402 	[RTM_FAM(RTM_NEWTFILTER)]   = NLMSG_LENGTH(sizeof(struct tcmsg)),
403 	[RTM_FAM(RTM_NEWACTION)]    = NLMSG_LENGTH(sizeof(struct tcamsg)),
404 	[RTM_FAM(RTM_GETMULTICAST)] = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
405 	[RTM_FAM(RTM_GETANYCAST)]   = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
406 };
407 
408 static const int rta_max[RTM_NR_FAMILIES] =
409 {
410 	[RTM_FAM(RTM_NEWLINK)]      = IFLA_MAX,
411 	[RTM_FAM(RTM_NEWADDR)]      = IFA_MAX,
412 	[RTM_FAM(RTM_NEWROUTE)]     = RTA_MAX,
413 	[RTM_FAM(RTM_NEWRULE)]      = FRA_MAX,
414 	[RTM_FAM(RTM_NEWQDISC)]     = TCA_MAX,
415 	[RTM_FAM(RTM_NEWTCLASS)]    = TCA_MAX,
416 	[RTM_FAM(RTM_NEWTFILTER)]   = TCA_MAX,
417 	[RTM_FAM(RTM_NEWACTION)]    = TCAA_MAX,
418 };
419 
420 void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
421 {
422 	struct rtattr *rta;
423 	int size = RTA_LENGTH(attrlen);
424 
425 	rta = (struct rtattr*)skb_put(skb, RTA_ALIGN(size));
426 	rta->rta_type = attrtype;
427 	rta->rta_len = size;
428 	memcpy(RTA_DATA(rta), data, attrlen);
429 	memset(RTA_DATA(rta) + attrlen, 0, RTA_ALIGN(size) - size);
430 }
431 
432 int rtnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, unsigned group, int echo)
433 {
434 	struct sock *rtnl = net->rtnl;
435 	int err = 0;
436 
437 	NETLINK_CB(skb).dst_group = group;
438 	if (echo)
439 		atomic_inc(&skb->users);
440 	netlink_broadcast(rtnl, skb, pid, group, GFP_KERNEL);
441 	if (echo)
442 		err = netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
443 	return err;
444 }
445 
446 int rtnl_unicast(struct sk_buff *skb, struct net *net, u32 pid)
447 {
448 	struct sock *rtnl = net->rtnl;
449 
450 	return nlmsg_unicast(rtnl, skb, pid);
451 }
452 
453 int rtnl_notify(struct sk_buff *skb, struct net *net, u32 pid, u32 group,
454 		struct nlmsghdr *nlh, gfp_t flags)
455 {
456 	struct sock *rtnl = net->rtnl;
457 	int report = 0;
458 
459 	if (nlh)
460 		report = nlmsg_report(nlh);
461 
462 	return nlmsg_notify(rtnl, skb, pid, group, report, flags);
463 }
464 
465 void rtnl_set_sk_err(struct net *net, u32 group, int error)
466 {
467 	struct sock *rtnl = net->rtnl;
468 
469 	netlink_set_err(rtnl, 0, group, error);
470 }
471 
472 int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics)
473 {
474 	struct nlattr *mx;
475 	int i, valid = 0;
476 
477 	mx = nla_nest_start(skb, RTA_METRICS);
478 	if (mx == NULL)
479 		return -ENOBUFS;
480 
481 	for (i = 0; i < RTAX_MAX; i++) {
482 		if (metrics[i]) {
483 			valid++;
484 			NLA_PUT_U32(skb, i+1, metrics[i]);
485 		}
486 	}
487 
488 	if (!valid) {
489 		nla_nest_cancel(skb, mx);
490 		return 0;
491 	}
492 
493 	return nla_nest_end(skb, mx);
494 
495 nla_put_failure:
496 	return nla_nest_cancel(skb, mx);
497 }
498 
499 int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id,
500 		       u32 ts, u32 tsage, long expires, u32 error)
501 {
502 	struct rta_cacheinfo ci = {
503 		.rta_lastuse = jiffies_to_clock_t(jiffies - dst->lastuse),
504 		.rta_used = dst->__use,
505 		.rta_clntref = atomic_read(&(dst->__refcnt)),
506 		.rta_error = error,
507 		.rta_id =  id,
508 		.rta_ts = ts,
509 		.rta_tsage = tsage,
510 	};
511 
512 	if (expires)
513 		ci.rta_expires = jiffies_to_clock_t(expires);
514 
515 	return nla_put(skb, RTA_CACHEINFO, sizeof(ci), &ci);
516 }
517 
518 EXPORT_SYMBOL_GPL(rtnl_put_cacheinfo);
519 
520 static void set_operstate(struct net_device *dev, unsigned char transition)
521 {
522 	unsigned char operstate = dev->operstate;
523 
524 	switch(transition) {
525 	case IF_OPER_UP:
526 		if ((operstate == IF_OPER_DORMANT ||
527 		     operstate == IF_OPER_UNKNOWN) &&
528 		    !netif_dormant(dev))
529 			operstate = IF_OPER_UP;
530 		break;
531 
532 	case IF_OPER_DORMANT:
533 		if (operstate == IF_OPER_UP ||
534 		    operstate == IF_OPER_UNKNOWN)
535 			operstate = IF_OPER_DORMANT;
536 		break;
537 	}
538 
539 	if (dev->operstate != operstate) {
540 		write_lock_bh(&dev_base_lock);
541 		dev->operstate = operstate;
542 		write_unlock_bh(&dev_base_lock);
543 		netdev_state_change(dev);
544 	}
545 }
546 
547 static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
548 				 struct net_device_stats *b)
549 {
550 	a->rx_packets = b->rx_packets;
551 	a->tx_packets = b->tx_packets;
552 	a->rx_bytes = b->rx_bytes;
553 	a->tx_bytes = b->tx_bytes;
554 	a->rx_errors = b->rx_errors;
555 	a->tx_errors = b->tx_errors;
556 	a->rx_dropped = b->rx_dropped;
557 	a->tx_dropped = b->tx_dropped;
558 
559 	a->multicast = b->multicast;
560 	a->collisions = b->collisions;
561 
562 	a->rx_length_errors = b->rx_length_errors;
563 	a->rx_over_errors = b->rx_over_errors;
564 	a->rx_crc_errors = b->rx_crc_errors;
565 	a->rx_frame_errors = b->rx_frame_errors;
566 	a->rx_fifo_errors = b->rx_fifo_errors;
567 	a->rx_missed_errors = b->rx_missed_errors;
568 
569 	a->tx_aborted_errors = b->tx_aborted_errors;
570 	a->tx_carrier_errors = b->tx_carrier_errors;
571 	a->tx_fifo_errors = b->tx_fifo_errors;
572 	a->tx_heartbeat_errors = b->tx_heartbeat_errors;
573 	a->tx_window_errors = b->tx_window_errors;
574 
575 	a->rx_compressed = b->rx_compressed;
576 	a->tx_compressed = b->tx_compressed;
577 };
578 
579 static inline size_t if_nlmsg_size(const struct net_device *dev)
580 {
581 	return NLMSG_ALIGN(sizeof(struct ifinfomsg))
582 	       + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
583 	       + nla_total_size(IFNAMSIZ) /* IFLA_QDISC */
584 	       + nla_total_size(sizeof(struct rtnl_link_ifmap))
585 	       + nla_total_size(sizeof(struct rtnl_link_stats))
586 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
587 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_BROADCAST */
588 	       + nla_total_size(4) /* IFLA_TXQLEN */
589 	       + nla_total_size(4) /* IFLA_WEIGHT */
590 	       + nla_total_size(4) /* IFLA_MTU */
591 	       + nla_total_size(4) /* IFLA_LINK */
592 	       + nla_total_size(4) /* IFLA_MASTER */
593 	       + nla_total_size(1) /* IFLA_OPERSTATE */
594 	       + nla_total_size(1) /* IFLA_LINKMODE */
595 	       + rtnl_link_get_size(dev); /* IFLA_LINKINFO */
596 }
597 
598 static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
599 			    int type, u32 pid, u32 seq, u32 change,
600 			    unsigned int flags)
601 {
602 	struct ifinfomsg *ifm;
603 	struct nlmsghdr *nlh;
604 
605 	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ifm), flags);
606 	if (nlh == NULL)
607 		return -EMSGSIZE;
608 
609 	ifm = nlmsg_data(nlh);
610 	ifm->ifi_family = AF_UNSPEC;
611 	ifm->__ifi_pad = 0;
612 	ifm->ifi_type = dev->type;
613 	ifm->ifi_index = dev->ifindex;
614 	ifm->ifi_flags = dev_get_flags(dev);
615 	ifm->ifi_change = change;
616 
617 	NLA_PUT_STRING(skb, IFLA_IFNAME, dev->name);
618 	NLA_PUT_U32(skb, IFLA_TXQLEN, dev->tx_queue_len);
619 	NLA_PUT_U8(skb, IFLA_OPERSTATE,
620 		   netif_running(dev) ? dev->operstate : IF_OPER_DOWN);
621 	NLA_PUT_U8(skb, IFLA_LINKMODE, dev->link_mode);
622 	NLA_PUT_U32(skb, IFLA_MTU, dev->mtu);
623 
624 	if (dev->ifindex != dev->iflink)
625 		NLA_PUT_U32(skb, IFLA_LINK, dev->iflink);
626 
627 	if (dev->master)
628 		NLA_PUT_U32(skb, IFLA_MASTER, dev->master->ifindex);
629 
630 	if (dev->qdisc_sleeping)
631 		NLA_PUT_STRING(skb, IFLA_QDISC, dev->qdisc_sleeping->ops->id);
632 
633 	if (1) {
634 		struct rtnl_link_ifmap map = {
635 			.mem_start   = dev->mem_start,
636 			.mem_end     = dev->mem_end,
637 			.base_addr   = dev->base_addr,
638 			.irq         = dev->irq,
639 			.dma         = dev->dma,
640 			.port        = dev->if_port,
641 		};
642 		NLA_PUT(skb, IFLA_MAP, sizeof(map), &map);
643 	}
644 
645 	if (dev->addr_len) {
646 		NLA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr);
647 		NLA_PUT(skb, IFLA_BROADCAST, dev->addr_len, dev->broadcast);
648 	}
649 
650 	if (dev->get_stats) {
651 		struct net_device_stats *stats = dev->get_stats(dev);
652 		if (stats) {
653 			struct nlattr *attr;
654 
655 			attr = nla_reserve(skb, IFLA_STATS,
656 					   sizeof(struct rtnl_link_stats));
657 			if (attr == NULL)
658 				goto nla_put_failure;
659 
660 			copy_rtnl_link_stats(nla_data(attr), stats);
661 		}
662 	}
663 
664 	if (dev->rtnl_link_ops) {
665 		if (rtnl_link_fill(skb, dev) < 0)
666 			goto nla_put_failure;
667 	}
668 
669 	return nlmsg_end(skb, nlh);
670 
671 nla_put_failure:
672 	nlmsg_cancel(skb, nlh);
673 	return -EMSGSIZE;
674 }
675 
676 static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
677 {
678 	struct net *net = sock_net(skb->sk);
679 	int idx;
680 	int s_idx = cb->args[0];
681 	struct net_device *dev;
682 
683 	idx = 0;
684 	for_each_netdev(net, dev) {
685 		if (idx < s_idx)
686 			goto cont;
687 		if (rtnl_fill_ifinfo(skb, dev, RTM_NEWLINK,
688 				     NETLINK_CB(cb->skb).pid,
689 				     cb->nlh->nlmsg_seq, 0, NLM_F_MULTI) <= 0)
690 			break;
691 cont:
692 		idx++;
693 	}
694 	cb->args[0] = idx;
695 
696 	return skb->len;
697 }
698 
699 const struct nla_policy ifla_policy[IFLA_MAX+1] = {
700 	[IFLA_IFNAME]		= { .type = NLA_STRING, .len = IFNAMSIZ-1 },
701 	[IFLA_ADDRESS]		= { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
702 	[IFLA_BROADCAST]	= { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
703 	[IFLA_MAP]		= { .len = sizeof(struct rtnl_link_ifmap) },
704 	[IFLA_MTU]		= { .type = NLA_U32 },
705 	[IFLA_LINK]		= { .type = NLA_U32 },
706 	[IFLA_TXQLEN]		= { .type = NLA_U32 },
707 	[IFLA_WEIGHT]		= { .type = NLA_U32 },
708 	[IFLA_OPERSTATE]	= { .type = NLA_U8 },
709 	[IFLA_LINKMODE]		= { .type = NLA_U8 },
710 	[IFLA_LINKINFO]		= { .type = NLA_NESTED },
711 	[IFLA_NET_NS_PID]	= { .type = NLA_U32 },
712 };
713 
714 static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
715 	[IFLA_INFO_KIND]	= { .type = NLA_STRING },
716 	[IFLA_INFO_DATA]	= { .type = NLA_NESTED },
717 };
718 
719 static struct net *get_net_ns_by_pid(pid_t pid)
720 {
721 	struct task_struct *tsk;
722 	struct net *net;
723 
724 	/* Lookup the network namespace */
725 	net = ERR_PTR(-ESRCH);
726 	rcu_read_lock();
727 	tsk = find_task_by_vpid(pid);
728 	if (tsk) {
729 		struct nsproxy *nsproxy;
730 		nsproxy = task_nsproxy(tsk);
731 		if (nsproxy)
732 			net = get_net(nsproxy->net_ns);
733 	}
734 	rcu_read_unlock();
735 	return net;
736 }
737 
738 static int validate_linkmsg(struct net_device *dev, struct nlattr *tb[])
739 {
740 	if (dev) {
741 		if (tb[IFLA_ADDRESS] &&
742 		    nla_len(tb[IFLA_ADDRESS]) < dev->addr_len)
743 			return -EINVAL;
744 
745 		if (tb[IFLA_BROADCAST] &&
746 		    nla_len(tb[IFLA_BROADCAST]) < dev->addr_len)
747 			return -EINVAL;
748 	}
749 
750 	return 0;
751 }
752 
753 static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
754 		      struct nlattr **tb, char *ifname, int modified)
755 {
756 	int send_addr_notify = 0;
757 	int err;
758 
759 	if (tb[IFLA_NET_NS_PID]) {
760 		struct net *net;
761 		net = get_net_ns_by_pid(nla_get_u32(tb[IFLA_NET_NS_PID]));
762 		if (IS_ERR(net)) {
763 			err = PTR_ERR(net);
764 			goto errout;
765 		}
766 		err = dev_change_net_namespace(dev, net, ifname);
767 		put_net(net);
768 		if (err)
769 			goto errout;
770 		modified = 1;
771 	}
772 
773 	if (tb[IFLA_MAP]) {
774 		struct rtnl_link_ifmap *u_map;
775 		struct ifmap k_map;
776 
777 		if (!dev->set_config) {
778 			err = -EOPNOTSUPP;
779 			goto errout;
780 		}
781 
782 		if (!netif_device_present(dev)) {
783 			err = -ENODEV;
784 			goto errout;
785 		}
786 
787 		u_map = nla_data(tb[IFLA_MAP]);
788 		k_map.mem_start = (unsigned long) u_map->mem_start;
789 		k_map.mem_end = (unsigned long) u_map->mem_end;
790 		k_map.base_addr = (unsigned short) u_map->base_addr;
791 		k_map.irq = (unsigned char) u_map->irq;
792 		k_map.dma = (unsigned char) u_map->dma;
793 		k_map.port = (unsigned char) u_map->port;
794 
795 		err = dev->set_config(dev, &k_map);
796 		if (err < 0)
797 			goto errout;
798 
799 		modified = 1;
800 	}
801 
802 	if (tb[IFLA_ADDRESS]) {
803 		struct sockaddr *sa;
804 		int len;
805 
806 		if (!dev->set_mac_address) {
807 			err = -EOPNOTSUPP;
808 			goto errout;
809 		}
810 
811 		if (!netif_device_present(dev)) {
812 			err = -ENODEV;
813 			goto errout;
814 		}
815 
816 		len = sizeof(sa_family_t) + dev->addr_len;
817 		sa = kmalloc(len, GFP_KERNEL);
818 		if (!sa) {
819 			err = -ENOMEM;
820 			goto errout;
821 		}
822 		sa->sa_family = dev->type;
823 		memcpy(sa->sa_data, nla_data(tb[IFLA_ADDRESS]),
824 		       dev->addr_len);
825 		err = dev->set_mac_address(dev, sa);
826 		kfree(sa);
827 		if (err)
828 			goto errout;
829 		send_addr_notify = 1;
830 		modified = 1;
831 	}
832 
833 	if (tb[IFLA_MTU]) {
834 		err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
835 		if (err < 0)
836 			goto errout;
837 		modified = 1;
838 	}
839 
840 	/*
841 	 * Interface selected by interface index but interface
842 	 * name provided implies that a name change has been
843 	 * requested.
844 	 */
845 	if (ifm->ifi_index > 0 && ifname[0]) {
846 		err = dev_change_name(dev, ifname);
847 		if (err < 0)
848 			goto errout;
849 		modified = 1;
850 	}
851 
852 	if (tb[IFLA_BROADCAST]) {
853 		nla_memcpy(dev->broadcast, tb[IFLA_BROADCAST], dev->addr_len);
854 		send_addr_notify = 1;
855 	}
856 
857 	if (ifm->ifi_flags || ifm->ifi_change) {
858 		unsigned int flags = ifm->ifi_flags;
859 
860 		/* bugwards compatibility: ifi_change == 0 is treated as ~0 */
861 		if (ifm->ifi_change)
862 			flags = (flags & ifm->ifi_change) |
863 				(dev->flags & ~ifm->ifi_change);
864 		dev_change_flags(dev, flags);
865 	}
866 
867 	if (tb[IFLA_TXQLEN])
868 		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
869 
870 	if (tb[IFLA_OPERSTATE])
871 		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
872 
873 	if (tb[IFLA_LINKMODE]) {
874 		write_lock_bh(&dev_base_lock);
875 		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
876 		write_unlock_bh(&dev_base_lock);
877 	}
878 
879 	err = 0;
880 
881 errout:
882 	if (err < 0 && modified && net_ratelimit())
883 		printk(KERN_WARNING "A link change request failed with "
884 		       "some changes comitted already. Interface %s may "
885 		       "have been left with an inconsistent configuration, "
886 		       "please check.\n", dev->name);
887 
888 	if (send_addr_notify)
889 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
890 	return err;
891 }
892 
893 static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
894 {
895 	struct net *net = sock_net(skb->sk);
896 	struct ifinfomsg *ifm;
897 	struct net_device *dev;
898 	int err;
899 	struct nlattr *tb[IFLA_MAX+1];
900 	char ifname[IFNAMSIZ];
901 
902 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
903 	if (err < 0)
904 		goto errout;
905 
906 	if (tb[IFLA_IFNAME])
907 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
908 	else
909 		ifname[0] = '\0';
910 
911 	err = -EINVAL;
912 	ifm = nlmsg_data(nlh);
913 	if (ifm->ifi_index > 0)
914 		dev = dev_get_by_index(net, ifm->ifi_index);
915 	else if (tb[IFLA_IFNAME])
916 		dev = dev_get_by_name(net, ifname);
917 	else
918 		goto errout;
919 
920 	if (dev == NULL) {
921 		err = -ENODEV;
922 		goto errout;
923 	}
924 
925 	if ((err = validate_linkmsg(dev, tb)) < 0)
926 		goto errout_dev;
927 
928 	err = do_setlink(dev, ifm, tb, ifname, 0);
929 errout_dev:
930 	dev_put(dev);
931 errout:
932 	return err;
933 }
934 
935 static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
936 {
937 	struct net *net = sock_net(skb->sk);
938 	const struct rtnl_link_ops *ops;
939 	struct net_device *dev;
940 	struct ifinfomsg *ifm;
941 	char ifname[IFNAMSIZ];
942 	struct nlattr *tb[IFLA_MAX+1];
943 	int err;
944 
945 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
946 	if (err < 0)
947 		return err;
948 
949 	if (tb[IFLA_IFNAME])
950 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
951 
952 	ifm = nlmsg_data(nlh);
953 	if (ifm->ifi_index > 0)
954 		dev = __dev_get_by_index(net, ifm->ifi_index);
955 	else if (tb[IFLA_IFNAME])
956 		dev = __dev_get_by_name(net, ifname);
957 	else
958 		return -EINVAL;
959 
960 	if (!dev)
961 		return -ENODEV;
962 
963 	ops = dev->rtnl_link_ops;
964 	if (!ops)
965 		return -EOPNOTSUPP;
966 
967 	ops->dellink(dev);
968 	return 0;
969 }
970 
971 struct net_device *rtnl_create_link(struct net *net, char *ifname,
972 		const struct rtnl_link_ops *ops, struct nlattr *tb[])
973 {
974 	int err;
975 	struct net_device *dev;
976 
977 	err = -ENOMEM;
978 	dev = alloc_netdev(ops->priv_size, ifname, ops->setup);
979 	if (!dev)
980 		goto err;
981 
982 	if (strchr(dev->name, '%')) {
983 		err = dev_alloc_name(dev, dev->name);
984 		if (err < 0)
985 			goto err_free;
986 	}
987 
988 	dev_net_set(dev, net);
989 	dev->rtnl_link_ops = ops;
990 
991 	if (tb[IFLA_MTU])
992 		dev->mtu = nla_get_u32(tb[IFLA_MTU]);
993 	if (tb[IFLA_ADDRESS])
994 		memcpy(dev->dev_addr, nla_data(tb[IFLA_ADDRESS]),
995 				nla_len(tb[IFLA_ADDRESS]));
996 	if (tb[IFLA_BROADCAST])
997 		memcpy(dev->broadcast, nla_data(tb[IFLA_BROADCAST]),
998 				nla_len(tb[IFLA_BROADCAST]));
999 	if (tb[IFLA_TXQLEN])
1000 		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
1001 	if (tb[IFLA_OPERSTATE])
1002 		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
1003 	if (tb[IFLA_LINKMODE])
1004 		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
1005 
1006 	return dev;
1007 
1008 err_free:
1009 	free_netdev(dev);
1010 err:
1011 	return ERR_PTR(err);
1012 }
1013 
1014 static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
1015 {
1016 	struct net *net = sock_net(skb->sk);
1017 	const struct rtnl_link_ops *ops;
1018 	struct net_device *dev;
1019 	struct ifinfomsg *ifm;
1020 	char kind[MODULE_NAME_LEN];
1021 	char ifname[IFNAMSIZ];
1022 	struct nlattr *tb[IFLA_MAX+1];
1023 	struct nlattr *linkinfo[IFLA_INFO_MAX+1];
1024 	int err;
1025 
1026 #ifdef CONFIG_KMOD
1027 replay:
1028 #endif
1029 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
1030 	if (err < 0)
1031 		return err;
1032 
1033 	if (tb[IFLA_IFNAME])
1034 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
1035 	else
1036 		ifname[0] = '\0';
1037 
1038 	ifm = nlmsg_data(nlh);
1039 	if (ifm->ifi_index > 0)
1040 		dev = __dev_get_by_index(net, ifm->ifi_index);
1041 	else if (ifname[0])
1042 		dev = __dev_get_by_name(net, ifname);
1043 	else
1044 		dev = NULL;
1045 
1046 	if ((err = validate_linkmsg(dev, tb)) < 0)
1047 		return err;
1048 
1049 	if (tb[IFLA_LINKINFO]) {
1050 		err = nla_parse_nested(linkinfo, IFLA_INFO_MAX,
1051 				       tb[IFLA_LINKINFO], ifla_info_policy);
1052 		if (err < 0)
1053 			return err;
1054 	} else
1055 		memset(linkinfo, 0, sizeof(linkinfo));
1056 
1057 	if (linkinfo[IFLA_INFO_KIND]) {
1058 		nla_strlcpy(kind, linkinfo[IFLA_INFO_KIND], sizeof(kind));
1059 		ops = rtnl_link_ops_get(kind);
1060 	} else {
1061 		kind[0] = '\0';
1062 		ops = NULL;
1063 	}
1064 
1065 	if (1) {
1066 		struct nlattr *attr[ops ? ops->maxtype + 1 : 0], **data = NULL;
1067 
1068 		if (ops) {
1069 			if (ops->maxtype && linkinfo[IFLA_INFO_DATA]) {
1070 				err = nla_parse_nested(attr, ops->maxtype,
1071 						       linkinfo[IFLA_INFO_DATA],
1072 						       ops->policy);
1073 				if (err < 0)
1074 					return err;
1075 				data = attr;
1076 			}
1077 			if (ops->validate) {
1078 				err = ops->validate(tb, data);
1079 				if (err < 0)
1080 					return err;
1081 			}
1082 		}
1083 
1084 		if (dev) {
1085 			int modified = 0;
1086 
1087 			if (nlh->nlmsg_flags & NLM_F_EXCL)
1088 				return -EEXIST;
1089 			if (nlh->nlmsg_flags & NLM_F_REPLACE)
1090 				return -EOPNOTSUPP;
1091 
1092 			if (linkinfo[IFLA_INFO_DATA]) {
1093 				if (!ops || ops != dev->rtnl_link_ops ||
1094 				    !ops->changelink)
1095 					return -EOPNOTSUPP;
1096 
1097 				err = ops->changelink(dev, tb, data);
1098 				if (err < 0)
1099 					return err;
1100 				modified = 1;
1101 			}
1102 
1103 			return do_setlink(dev, ifm, tb, ifname, modified);
1104 		}
1105 
1106 		if (!(nlh->nlmsg_flags & NLM_F_CREATE))
1107 			return -ENODEV;
1108 
1109 		if (ifm->ifi_index || ifm->ifi_flags || ifm->ifi_change)
1110 			return -EOPNOTSUPP;
1111 		if (tb[IFLA_MAP] || tb[IFLA_MASTER] || tb[IFLA_PROTINFO])
1112 			return -EOPNOTSUPP;
1113 
1114 		if (!ops) {
1115 #ifdef CONFIG_KMOD
1116 			if (kind[0]) {
1117 				__rtnl_unlock();
1118 				request_module("rtnl-link-%s", kind);
1119 				rtnl_lock();
1120 				ops = rtnl_link_ops_get(kind);
1121 				if (ops)
1122 					goto replay;
1123 			}
1124 #endif
1125 			return -EOPNOTSUPP;
1126 		}
1127 
1128 		if (!ifname[0])
1129 			snprintf(ifname, IFNAMSIZ, "%s%%d", ops->kind);
1130 
1131 		dev = rtnl_create_link(net, ifname, ops, tb);
1132 
1133 		if (IS_ERR(dev))
1134 			err = PTR_ERR(dev);
1135 		else if (ops->newlink)
1136 			err = ops->newlink(dev, tb, data);
1137 		else
1138 			err = register_netdevice(dev);
1139 
1140 		if (err < 0 && !IS_ERR(dev))
1141 			free_netdev(dev);
1142 		return err;
1143 	}
1144 }
1145 
1146 static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
1147 {
1148 	struct net *net = sock_net(skb->sk);
1149 	struct ifinfomsg *ifm;
1150 	struct nlattr *tb[IFLA_MAX+1];
1151 	struct net_device *dev = NULL;
1152 	struct sk_buff *nskb;
1153 	int err;
1154 
1155 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
1156 	if (err < 0)
1157 		return err;
1158 
1159 	ifm = nlmsg_data(nlh);
1160 	if (ifm->ifi_index > 0) {
1161 		dev = dev_get_by_index(net, ifm->ifi_index);
1162 		if (dev == NULL)
1163 			return -ENODEV;
1164 	} else
1165 		return -EINVAL;
1166 
1167 	nskb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
1168 	if (nskb == NULL) {
1169 		err = -ENOBUFS;
1170 		goto errout;
1171 	}
1172 
1173 	err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).pid,
1174 			       nlh->nlmsg_seq, 0, 0);
1175 	if (err < 0) {
1176 		/* -EMSGSIZE implies BUG in if_nlmsg_size */
1177 		WARN_ON(err == -EMSGSIZE);
1178 		kfree_skb(nskb);
1179 		goto errout;
1180 	}
1181 	err = rtnl_unicast(nskb, net, NETLINK_CB(skb).pid);
1182 errout:
1183 	dev_put(dev);
1184 
1185 	return err;
1186 }
1187 
1188 static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
1189 {
1190 	int idx;
1191 	int s_idx = cb->family;
1192 
1193 	if (s_idx == 0)
1194 		s_idx = 1;
1195 	for (idx=1; idx<NPROTO; idx++) {
1196 		int type = cb->nlh->nlmsg_type-RTM_BASE;
1197 		if (idx < s_idx || idx == PF_PACKET)
1198 			continue;
1199 		if (rtnl_msg_handlers[idx] == NULL ||
1200 		    rtnl_msg_handlers[idx][type].dumpit == NULL)
1201 			continue;
1202 		if (idx > s_idx)
1203 			memset(&cb->args[0], 0, sizeof(cb->args));
1204 		if (rtnl_msg_handlers[idx][type].dumpit(skb, cb))
1205 			break;
1206 	}
1207 	cb->family = idx;
1208 
1209 	return skb->len;
1210 }
1211 
1212 void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change)
1213 {
1214 	struct net *net = dev_net(dev);
1215 	struct sk_buff *skb;
1216 	int err = -ENOBUFS;
1217 
1218 	skb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
1219 	if (skb == NULL)
1220 		goto errout;
1221 
1222 	err = rtnl_fill_ifinfo(skb, dev, type, 0, 0, change, 0);
1223 	if (err < 0) {
1224 		/* -EMSGSIZE implies BUG in if_nlmsg_size() */
1225 		WARN_ON(err == -EMSGSIZE);
1226 		kfree_skb(skb);
1227 		goto errout;
1228 	}
1229 	err = rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_KERNEL);
1230 errout:
1231 	if (err < 0)
1232 		rtnl_set_sk_err(net, RTNLGRP_LINK, err);
1233 }
1234 
1235 /* Protected by RTNL sempahore.  */
1236 static struct rtattr **rta_buf;
1237 static int rtattr_max;
1238 
1239 /* Process one rtnetlink message. */
1240 
1241 static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
1242 {
1243 	struct net *net = sock_net(skb->sk);
1244 	rtnl_doit_func doit;
1245 	int sz_idx, kind;
1246 	int min_len;
1247 	int family;
1248 	int type;
1249 	int err;
1250 
1251 	type = nlh->nlmsg_type;
1252 	if (type > RTM_MAX)
1253 		return -EOPNOTSUPP;
1254 
1255 	type -= RTM_BASE;
1256 
1257 	/* All the messages must have at least 1 byte length */
1258 	if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct rtgenmsg)))
1259 		return 0;
1260 
1261 	family = ((struct rtgenmsg*)NLMSG_DATA(nlh))->rtgen_family;
1262 	if (family >= NPROTO)
1263 		return -EAFNOSUPPORT;
1264 
1265 	sz_idx = type>>2;
1266 	kind = type&3;
1267 
1268 	if (kind != 2 && security_netlink_recv(skb, CAP_NET_ADMIN))
1269 		return -EPERM;
1270 
1271 	if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
1272 		struct sock *rtnl;
1273 		rtnl_dumpit_func dumpit;
1274 
1275 		dumpit = rtnl_get_dumpit(family, type);
1276 		if (dumpit == NULL)
1277 			return -EOPNOTSUPP;
1278 
1279 		__rtnl_unlock();
1280 		rtnl = net->rtnl;
1281 		err = netlink_dump_start(rtnl, skb, nlh, dumpit, NULL);
1282 		rtnl_lock();
1283 		return err;
1284 	}
1285 
1286 	memset(rta_buf, 0, (rtattr_max * sizeof(struct rtattr *)));
1287 
1288 	min_len = rtm_min[sz_idx];
1289 	if (nlh->nlmsg_len < min_len)
1290 		return -EINVAL;
1291 
1292 	if (nlh->nlmsg_len > min_len) {
1293 		int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
1294 		struct rtattr *attr = (void*)nlh + NLMSG_ALIGN(min_len);
1295 
1296 		while (RTA_OK(attr, attrlen)) {
1297 			unsigned flavor = attr->rta_type;
1298 			if (flavor) {
1299 				if (flavor > rta_max[sz_idx])
1300 					return -EINVAL;
1301 				rta_buf[flavor-1] = attr;
1302 			}
1303 			attr = RTA_NEXT(attr, attrlen);
1304 		}
1305 	}
1306 
1307 	doit = rtnl_get_doit(family, type);
1308 	if (doit == NULL)
1309 		return -EOPNOTSUPP;
1310 
1311 	return doit(skb, nlh, (void *)&rta_buf[0]);
1312 }
1313 
1314 static void rtnetlink_rcv(struct sk_buff *skb)
1315 {
1316 	rtnl_lock();
1317 	netlink_rcv_skb(skb, &rtnetlink_rcv_msg);
1318 	rtnl_unlock();
1319 }
1320 
1321 static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr)
1322 {
1323 	struct net_device *dev = ptr;
1324 
1325 	switch (event) {
1326 	case NETDEV_UNREGISTER:
1327 		rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
1328 		break;
1329 	case NETDEV_REGISTER:
1330 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
1331 		break;
1332 	case NETDEV_UP:
1333 	case NETDEV_DOWN:
1334 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1335 		break;
1336 	case NETDEV_CHANGE:
1337 	case NETDEV_GOING_DOWN:
1338 		break;
1339 	default:
1340 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
1341 		break;
1342 	}
1343 	return NOTIFY_DONE;
1344 }
1345 
1346 static struct notifier_block rtnetlink_dev_notifier = {
1347 	.notifier_call	= rtnetlink_event,
1348 };
1349 
1350 
1351 static int rtnetlink_net_init(struct net *net)
1352 {
1353 	struct sock *sk;
1354 	sk = netlink_kernel_create(net, NETLINK_ROUTE, RTNLGRP_MAX,
1355 				   rtnetlink_rcv, &rtnl_mutex, THIS_MODULE);
1356 	if (!sk)
1357 		return -ENOMEM;
1358 	net->rtnl = sk;
1359 	return 0;
1360 }
1361 
1362 static void rtnetlink_net_exit(struct net *net)
1363 {
1364 	netlink_kernel_release(net->rtnl);
1365 	net->rtnl = NULL;
1366 }
1367 
1368 static struct pernet_operations rtnetlink_net_ops = {
1369 	.init = rtnetlink_net_init,
1370 	.exit = rtnetlink_net_exit,
1371 };
1372 
1373 void __init rtnetlink_init(void)
1374 {
1375 	int i;
1376 
1377 	rtattr_max = 0;
1378 	for (i = 0; i < ARRAY_SIZE(rta_max); i++)
1379 		if (rta_max[i] > rtattr_max)
1380 			rtattr_max = rta_max[i];
1381 	rta_buf = kmalloc(rtattr_max * sizeof(struct rtattr *), GFP_KERNEL);
1382 	if (!rta_buf)
1383 		panic("rtnetlink_init: cannot allocate rta_buf\n");
1384 
1385 	if (register_pernet_subsys(&rtnetlink_net_ops))
1386 		panic("rtnetlink_init: cannot initialize rtnetlink\n");
1387 
1388 	netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
1389 	register_netdevice_notifier(&rtnetlink_dev_notifier);
1390 
1391 	rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink, rtnl_dump_ifinfo);
1392 	rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL);
1393 	rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL);
1394 	rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL);
1395 
1396 	rtnl_register(PF_UNSPEC, RTM_GETADDR, NULL, rtnl_dump_all);
1397 	rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all);
1398 }
1399 
1400 EXPORT_SYMBOL(__rta_fill);
1401 EXPORT_SYMBOL(rtnetlink_put_metrics);
1402 EXPORT_SYMBOL(rtnl_lock);
1403 EXPORT_SYMBOL(rtnl_trylock);
1404 EXPORT_SYMBOL(rtnl_unlock);
1405 EXPORT_SYMBOL(rtnl_unicast);
1406 EXPORT_SYMBOL(rtnl_notify);
1407 EXPORT_SYMBOL(rtnl_set_sk_err);
1408 EXPORT_SYMBOL(rtnl_create_link);
1409 EXPORT_SYMBOL(ifla_policy);
1410