xref: /openbmc/linux/net/core/rtnetlink.c (revision 2a0a6ebee1d68552152ae8d4aeda91d806995dec)
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/config.h>
20 #include <linux/errno.h>
21 #include <linux/module.h>
22 #include <linux/types.h>
23 #include <linux/socket.h>
24 #include <linux/kernel.h>
25 #include <linux/sched.h>
26 #include <linux/timer.h>
27 #include <linux/string.h>
28 #include <linux/sockios.h>
29 #include <linux/net.h>
30 #include <linux/fcntl.h>
31 #include <linux/mm.h>
32 #include <linux/slab.h>
33 #include <linux/interrupt.h>
34 #include <linux/capability.h>
35 #include <linux/skbuff.h>
36 #include <linux/init.h>
37 #include <linux/security.h>
38 
39 #include <asm/uaccess.h>
40 #include <asm/system.h>
41 #include <asm/string.h>
42 
43 #include <linux/inet.h>
44 #include <linux/netdevice.h>
45 #include <net/ip.h>
46 #include <net/protocol.h>
47 #include <net/arp.h>
48 #include <net/route.h>
49 #include <net/udp.h>
50 #include <net/sock.h>
51 #include <net/pkt_sched.h>
52 
53 DECLARE_MUTEX(rtnl_sem);
54 
55 void rtnl_lock(void)
56 {
57 	rtnl_shlock();
58 }
59 
60 int rtnl_lock_interruptible(void)
61 {
62 	return down_interruptible(&rtnl_sem);
63 }
64 
65 void rtnl_unlock(void)
66 {
67 	rtnl_shunlock();
68 
69 	netdev_run_todo();
70 }
71 
72 int rtattr_parse(struct rtattr *tb[], int maxattr, struct rtattr *rta, int len)
73 {
74 	memset(tb, 0, sizeof(struct rtattr*)*maxattr);
75 
76 	while (RTA_OK(rta, len)) {
77 		unsigned flavor = rta->rta_type;
78 		if (flavor && flavor <= maxattr)
79 			tb[flavor-1] = rta;
80 		rta = RTA_NEXT(rta, len);
81 	}
82 	return 0;
83 }
84 
85 struct sock *rtnl;
86 
87 struct rtnetlink_link * rtnetlink_links[NPROTO];
88 
89 static const int rtm_min[RTM_NR_FAMILIES] =
90 {
91 	[RTM_FAM(RTM_NEWLINK)]      = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
92 	[RTM_FAM(RTM_NEWADDR)]      = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
93 	[RTM_FAM(RTM_NEWROUTE)]     = NLMSG_LENGTH(sizeof(struct rtmsg)),
94 	[RTM_FAM(RTM_NEWNEIGH)]     = NLMSG_LENGTH(sizeof(struct ndmsg)),
95 	[RTM_FAM(RTM_NEWRULE)]      = NLMSG_LENGTH(sizeof(struct rtmsg)),
96 	[RTM_FAM(RTM_NEWQDISC)]     = NLMSG_LENGTH(sizeof(struct tcmsg)),
97 	[RTM_FAM(RTM_NEWTCLASS)]    = NLMSG_LENGTH(sizeof(struct tcmsg)),
98 	[RTM_FAM(RTM_NEWTFILTER)]   = NLMSG_LENGTH(sizeof(struct tcmsg)),
99 	[RTM_FAM(RTM_NEWACTION)]    = NLMSG_LENGTH(sizeof(struct tcamsg)),
100 	[RTM_FAM(RTM_NEWPREFIX)]    = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
101 	[RTM_FAM(RTM_GETMULTICAST)] = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
102 	[RTM_FAM(RTM_GETANYCAST)]   = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
103 };
104 
105 static const int rta_max[RTM_NR_FAMILIES] =
106 {
107 	[RTM_FAM(RTM_NEWLINK)]      = IFLA_MAX,
108 	[RTM_FAM(RTM_NEWADDR)]      = IFA_MAX,
109 	[RTM_FAM(RTM_NEWROUTE)]     = RTA_MAX,
110 	[RTM_FAM(RTM_NEWNEIGH)]     = NDA_MAX,
111 	[RTM_FAM(RTM_NEWRULE)]      = RTA_MAX,
112 	[RTM_FAM(RTM_NEWQDISC)]     = TCA_MAX,
113 	[RTM_FAM(RTM_NEWTCLASS)]    = TCA_MAX,
114 	[RTM_FAM(RTM_NEWTFILTER)]   = TCA_MAX,
115 	[RTM_FAM(RTM_NEWACTION)]    = TCAA_MAX,
116 };
117 
118 void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
119 {
120 	struct rtattr *rta;
121 	int size = RTA_LENGTH(attrlen);
122 
123 	rta = (struct rtattr*)skb_put(skb, RTA_ALIGN(size));
124 	rta->rta_type = attrtype;
125 	rta->rta_len = size;
126 	memcpy(RTA_DATA(rta), data, attrlen);
127 }
128 
129 size_t rtattr_strlcpy(char *dest, const struct rtattr *rta, size_t size)
130 {
131 	size_t ret = RTA_PAYLOAD(rta);
132 	char *src = RTA_DATA(rta);
133 
134 	if (ret > 0 && src[ret - 1] == '\0')
135 		ret--;
136 	if (size > 0) {
137 		size_t len = (ret >= size) ? size - 1 : ret;
138 		memset(dest, 0, size);
139 		memcpy(dest, src, len);
140 	}
141 	return ret;
142 }
143 
144 int rtnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo)
145 {
146 	int err = 0;
147 
148 	NETLINK_CB(skb).dst_groups = group;
149 	if (echo)
150 		atomic_inc(&skb->users);
151 	netlink_broadcast(rtnl, skb, pid, group, GFP_KERNEL);
152 	if (echo)
153 		err = netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
154 	return err;
155 }
156 
157 int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics)
158 {
159 	struct rtattr *mx = (struct rtattr*)skb->tail;
160 	int i;
161 
162 	RTA_PUT(skb, RTA_METRICS, 0, NULL);
163 	for (i=0; i<RTAX_MAX; i++) {
164 		if (metrics[i])
165 			RTA_PUT(skb, i+1, sizeof(u32), metrics+i);
166 	}
167 	mx->rta_len = skb->tail - (u8*)mx;
168 	if (mx->rta_len == RTA_LENGTH(0))
169 		skb_trim(skb, (u8*)mx - skb->data);
170 	return 0;
171 
172 rtattr_failure:
173 	skb_trim(skb, (u8*)mx - skb->data);
174 	return -1;
175 }
176 
177 
178 static int rtnetlink_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
179 				 int type, u32 pid, u32 seq, u32 change)
180 {
181 	struct ifinfomsg *r;
182 	struct nlmsghdr  *nlh;
183 	unsigned char	 *b = skb->tail;
184 
185 	nlh = NLMSG_PUT(skb, pid, seq, type, sizeof(*r));
186 	if (pid) nlh->nlmsg_flags |= NLM_F_MULTI;
187 	r = NLMSG_DATA(nlh);
188 	r->ifi_family = AF_UNSPEC;
189 	r->ifi_type = dev->type;
190 	r->ifi_index = dev->ifindex;
191 	r->ifi_flags = dev_get_flags(dev);
192 	r->ifi_change = change;
193 
194 	RTA_PUT(skb, IFLA_IFNAME, strlen(dev->name)+1, dev->name);
195 
196 	if (1) {
197 		u32 txqlen = dev->tx_queue_len;
198 		RTA_PUT(skb, IFLA_TXQLEN, sizeof(txqlen), &txqlen);
199 	}
200 
201 	if (1) {
202 		u32 weight = dev->weight;
203 		RTA_PUT(skb, IFLA_WEIGHT, sizeof(weight), &weight);
204 	}
205 
206 	if (1) {
207 		struct rtnl_link_ifmap map = {
208 			.mem_start   = dev->mem_start,
209 			.mem_end     = dev->mem_end,
210 			.base_addr   = dev->base_addr,
211 			.irq         = dev->irq,
212 			.dma         = dev->dma,
213 			.port        = dev->if_port,
214 		};
215 		RTA_PUT(skb, IFLA_MAP, sizeof(map), &map);
216 	}
217 
218 	if (dev->addr_len) {
219 		RTA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr);
220 		RTA_PUT(skb, IFLA_BROADCAST, dev->addr_len, dev->broadcast);
221 	}
222 
223 	if (1) {
224 		u32 mtu = dev->mtu;
225 		RTA_PUT(skb, IFLA_MTU, sizeof(mtu), &mtu);
226 	}
227 
228 	if (dev->ifindex != dev->iflink) {
229 		u32 iflink = dev->iflink;
230 		RTA_PUT(skb, IFLA_LINK, sizeof(iflink), &iflink);
231 	}
232 
233 	if (dev->qdisc_sleeping)
234 		RTA_PUT(skb, IFLA_QDISC,
235 			strlen(dev->qdisc_sleeping->ops->id) + 1,
236 			dev->qdisc_sleeping->ops->id);
237 
238 	if (dev->master) {
239 		u32 master = dev->master->ifindex;
240 		RTA_PUT(skb, IFLA_MASTER, sizeof(master), &master);
241 	}
242 
243 	if (dev->get_stats) {
244 		unsigned long *stats = (unsigned long*)dev->get_stats(dev);
245 		if (stats) {
246 			struct rtattr  *a;
247 			__u32	       *s;
248 			int		i;
249 			int		n = sizeof(struct rtnl_link_stats)/4;
250 
251 			a = __RTA_PUT(skb, IFLA_STATS, n*4);
252 			s = RTA_DATA(a);
253 			for (i=0; i<n; i++)
254 				s[i] = stats[i];
255 		}
256 	}
257 	nlh->nlmsg_len = skb->tail - b;
258 	return skb->len;
259 
260 nlmsg_failure:
261 rtattr_failure:
262 	skb_trim(skb, b - skb->data);
263 	return -1;
264 }
265 
266 static int rtnetlink_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
267 {
268 	int idx;
269 	int s_idx = cb->args[0];
270 	struct net_device *dev;
271 
272 	read_lock(&dev_base_lock);
273 	for (dev=dev_base, idx=0; dev; dev = dev->next, idx++) {
274 		if (idx < s_idx)
275 			continue;
276 		if (rtnetlink_fill_ifinfo(skb, dev, RTM_NEWLINK, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, 0) <= 0)
277 			break;
278 	}
279 	read_unlock(&dev_base_lock);
280 	cb->args[0] = idx;
281 
282 	return skb->len;
283 }
284 
285 static int do_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
286 {
287 	struct ifinfomsg  *ifm = NLMSG_DATA(nlh);
288 	struct rtattr    **ida = arg;
289 	struct net_device *dev;
290 	int err, send_addr_notify = 0;
291 
292 	if (ifm->ifi_index >= 0)
293 		dev = dev_get_by_index(ifm->ifi_index);
294 	else if (ida[IFLA_IFNAME - 1]) {
295 		char ifname[IFNAMSIZ];
296 
297 		if (rtattr_strlcpy(ifname, ida[IFLA_IFNAME - 1],
298 		                   IFNAMSIZ) >= IFNAMSIZ)
299 			return -EINVAL;
300 		dev = dev_get_by_name(ifname);
301 	} else
302 		return -EINVAL;
303 
304 	if (!dev)
305 		return -ENODEV;
306 
307 	err = -EINVAL;
308 
309 	if (ifm->ifi_flags)
310 		dev_change_flags(dev, ifm->ifi_flags);
311 
312 	if (ida[IFLA_MAP - 1]) {
313 		struct rtnl_link_ifmap *u_map;
314 		struct ifmap k_map;
315 
316 		if (!dev->set_config) {
317 			err = -EOPNOTSUPP;
318 			goto out;
319 		}
320 
321 		if (!netif_device_present(dev)) {
322 			err = -ENODEV;
323 			goto out;
324 		}
325 
326 		if (ida[IFLA_MAP - 1]->rta_len != RTA_LENGTH(sizeof(*u_map)))
327 			goto out;
328 
329 		u_map = RTA_DATA(ida[IFLA_MAP - 1]);
330 
331 		k_map.mem_start = (unsigned long) u_map->mem_start;
332 		k_map.mem_end = (unsigned long) u_map->mem_end;
333 		k_map.base_addr = (unsigned short) u_map->base_addr;
334 		k_map.irq = (unsigned char) u_map->irq;
335 		k_map.dma = (unsigned char) u_map->dma;
336 		k_map.port = (unsigned char) u_map->port;
337 
338 		err = dev->set_config(dev, &k_map);
339 
340 		if (err)
341 			goto out;
342 	}
343 
344 	if (ida[IFLA_ADDRESS - 1]) {
345 		if (!dev->set_mac_address) {
346 			err = -EOPNOTSUPP;
347 			goto out;
348 		}
349 		if (!netif_device_present(dev)) {
350 			err = -ENODEV;
351 			goto out;
352 		}
353 		if (ida[IFLA_ADDRESS - 1]->rta_len != RTA_LENGTH(dev->addr_len))
354 			goto out;
355 
356 		err = dev->set_mac_address(dev, RTA_DATA(ida[IFLA_ADDRESS - 1]));
357 		if (err)
358 			goto out;
359 		send_addr_notify = 1;
360 	}
361 
362 	if (ida[IFLA_BROADCAST - 1]) {
363 		if (ida[IFLA_BROADCAST - 1]->rta_len != RTA_LENGTH(dev->addr_len))
364 			goto out;
365 		memcpy(dev->broadcast, RTA_DATA(ida[IFLA_BROADCAST - 1]),
366 		       dev->addr_len);
367 		send_addr_notify = 1;
368 	}
369 
370 	if (ida[IFLA_MTU - 1]) {
371 		if (ida[IFLA_MTU - 1]->rta_len != RTA_LENGTH(sizeof(u32)))
372 			goto out;
373 		err = dev_set_mtu(dev, *((u32 *) RTA_DATA(ida[IFLA_MTU - 1])));
374 
375 		if (err)
376 			goto out;
377 
378 	}
379 
380 	if (ida[IFLA_TXQLEN - 1]) {
381 		if (ida[IFLA_TXQLEN - 1]->rta_len != RTA_LENGTH(sizeof(u32)))
382 			goto out;
383 
384 		dev->tx_queue_len = *((u32 *) RTA_DATA(ida[IFLA_TXQLEN - 1]));
385 	}
386 
387 	if (ida[IFLA_WEIGHT - 1]) {
388 		if (ida[IFLA_WEIGHT - 1]->rta_len != RTA_LENGTH(sizeof(u32)))
389 			goto out;
390 
391 		dev->weight = *((u32 *) RTA_DATA(ida[IFLA_WEIGHT - 1]));
392 	}
393 
394 	if (ifm->ifi_index >= 0 && ida[IFLA_IFNAME - 1]) {
395 		char ifname[IFNAMSIZ];
396 
397 		if (rtattr_strlcpy(ifname, ida[IFLA_IFNAME - 1],
398 		                   IFNAMSIZ) >= IFNAMSIZ)
399 			goto out;
400 		err = dev_change_name(dev, ifname);
401 		if (err)
402 			goto out;
403 	}
404 
405 	err = 0;
406 
407 out:
408 	if (send_addr_notify)
409 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
410 
411 	dev_put(dev);
412 	return err;
413 }
414 
415 static int rtnetlink_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
416 {
417 	int idx;
418 	int s_idx = cb->family;
419 
420 	if (s_idx == 0)
421 		s_idx = 1;
422 	for (idx=1; idx<NPROTO; idx++) {
423 		int type = cb->nlh->nlmsg_type-RTM_BASE;
424 		if (idx < s_idx || idx == PF_PACKET)
425 			continue;
426 		if (rtnetlink_links[idx] == NULL ||
427 		    rtnetlink_links[idx][type].dumpit == NULL)
428 			continue;
429 		if (idx > s_idx)
430 			memset(&cb->args[0], 0, sizeof(cb->args));
431 		if (rtnetlink_links[idx][type].dumpit(skb, cb))
432 			break;
433 	}
434 	cb->family = idx;
435 
436 	return skb->len;
437 }
438 
439 void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change)
440 {
441 	struct sk_buff *skb;
442 	int size = NLMSG_SPACE(sizeof(struct ifinfomsg) +
443 			       sizeof(struct rtnl_link_ifmap) +
444 			       sizeof(struct rtnl_link_stats) + 128);
445 
446 	skb = alloc_skb(size, GFP_KERNEL);
447 	if (!skb)
448 		return;
449 
450 	if (rtnetlink_fill_ifinfo(skb, dev, type, 0, 0, change) < 0) {
451 		kfree_skb(skb);
452 		return;
453 	}
454 	NETLINK_CB(skb).dst_groups = RTMGRP_LINK;
455 	netlink_broadcast(rtnl, skb, 0, RTMGRP_LINK, GFP_KERNEL);
456 }
457 
458 static int rtnetlink_done(struct netlink_callback *cb)
459 {
460 	return 0;
461 }
462 
463 /* Protected by RTNL sempahore.  */
464 static struct rtattr **rta_buf;
465 static int rtattr_max;
466 
467 /* Process one rtnetlink message. */
468 
469 static __inline__ int
470 rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp)
471 {
472 	struct rtnetlink_link *link;
473 	struct rtnetlink_link *link_tab;
474 	int sz_idx, kind;
475 	int min_len;
476 	int family;
477 	int type;
478 	int err;
479 
480 	/* Only requests are handled by kernel now */
481 	if (!(nlh->nlmsg_flags&NLM_F_REQUEST))
482 		return 0;
483 
484 	type = nlh->nlmsg_type;
485 
486 	/* A control message: ignore them */
487 	if (type < RTM_BASE)
488 		return 0;
489 
490 	/* Unknown message: reply with EINVAL */
491 	if (type > RTM_MAX)
492 		goto err_inval;
493 
494 	type -= RTM_BASE;
495 
496 	/* All the messages must have at least 1 byte length */
497 	if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct rtgenmsg)))
498 		return 0;
499 
500 	family = ((struct rtgenmsg*)NLMSG_DATA(nlh))->rtgen_family;
501 	if (family >= NPROTO) {
502 		*errp = -EAFNOSUPPORT;
503 		return -1;
504 	}
505 
506 	link_tab = rtnetlink_links[family];
507 	if (link_tab == NULL)
508 		link_tab = rtnetlink_links[PF_UNSPEC];
509 	link = &link_tab[type];
510 
511 	sz_idx = type>>2;
512 	kind = type&3;
513 
514 	if (kind != 2 && security_netlink_recv(skb)) {
515 		*errp = -EPERM;
516 		return -1;
517 	}
518 
519 	if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
520 		u32 rlen;
521 
522 		if (link->dumpit == NULL)
523 			link = &(rtnetlink_links[PF_UNSPEC][type]);
524 
525 		if (link->dumpit == NULL)
526 			goto err_inval;
527 
528 		if ((*errp = netlink_dump_start(rtnl, skb, nlh,
529 						link->dumpit,
530 						rtnetlink_done)) != 0) {
531 			return -1;
532 		}
533 		rlen = NLMSG_ALIGN(nlh->nlmsg_len);
534 		if (rlen > skb->len)
535 			rlen = skb->len;
536 		skb_pull(skb, rlen);
537 		return -1;
538 	}
539 
540 	memset(rta_buf, 0, (rtattr_max * sizeof(struct rtattr *)));
541 
542 	min_len = rtm_min[sz_idx];
543 	if (nlh->nlmsg_len < min_len)
544 		goto err_inval;
545 
546 	if (nlh->nlmsg_len > min_len) {
547 		int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
548 		struct rtattr *attr = (void*)nlh + NLMSG_ALIGN(min_len);
549 
550 		while (RTA_OK(attr, attrlen)) {
551 			unsigned flavor = attr->rta_type;
552 			if (flavor) {
553 				if (flavor > rta_max[sz_idx])
554 					goto err_inval;
555 				rta_buf[flavor-1] = attr;
556 			}
557 			attr = RTA_NEXT(attr, attrlen);
558 		}
559 	}
560 
561 	if (link->doit == NULL)
562 		link = &(rtnetlink_links[PF_UNSPEC][type]);
563 	if (link->doit == NULL)
564 		goto err_inval;
565 	err = link->doit(skb, nlh, (void *)&rta_buf[0]);
566 
567 	*errp = err;
568 	return err;
569 
570 err_inval:
571 	*errp = -EINVAL;
572 	return -1;
573 }
574 
575 /*
576  * Process one packet of messages.
577  * Malformed skbs with wrong lengths of messages are discarded silently.
578  */
579 
580 static inline int rtnetlink_rcv_skb(struct sk_buff *skb)
581 {
582 	int err;
583 	struct nlmsghdr * nlh;
584 
585 	while (skb->len >= NLMSG_SPACE(0)) {
586 		u32 rlen;
587 
588 		nlh = (struct nlmsghdr *)skb->data;
589 		if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
590 			return 0;
591 		rlen = NLMSG_ALIGN(nlh->nlmsg_len);
592 		if (rlen > skb->len)
593 			rlen = skb->len;
594 		if (rtnetlink_rcv_msg(skb, nlh, &err)) {
595 			/* Not error, but we must interrupt processing here:
596 			 *   Note, that in this case we do not pull message
597 			 *   from skb, it will be processed later.
598 			 */
599 			if (err == 0)
600 				return -1;
601 			netlink_ack(skb, nlh, err);
602 		} else if (nlh->nlmsg_flags&NLM_F_ACK)
603 			netlink_ack(skb, nlh, 0);
604 		skb_pull(skb, rlen);
605 	}
606 
607 	return 0;
608 }
609 
610 /*
611  *  rtnetlink input queue processing routine:
612  *	- process as much as there was in the queue upon entry.
613  *	- feed skbs to rtnetlink_rcv_skb, until it refuse a message,
614  *	  that will occur, when a dump started.
615  */
616 
617 static void rtnetlink_rcv(struct sock *sk, int len)
618 {
619 	unsigned int qlen = skb_queue_len(&sk->sk_receive_queue);
620 
621 	do {
622 		struct sk_buff *skb;
623 
624 		rtnl_lock();
625 
626 		if (qlen > skb_queue_len(&sk->sk_receive_queue))
627 			qlen = skb_queue_len(&sk->sk_receive_queue);
628 
629 		while (qlen--) {
630 			skb = skb_dequeue(&sk->sk_receive_queue);
631 			if (rtnetlink_rcv_skb(skb)) {
632 				if (skb->len) {
633 					skb_queue_head(&sk->sk_receive_queue,
634 						       skb);
635 					qlen++;
636 				} else
637 					kfree_skb(skb);
638 				break;
639 			}
640 			kfree_skb(skb);
641 		}
642 
643 		up(&rtnl_sem);
644 
645 		netdev_run_todo();
646 	} while (qlen);
647 }
648 
649 static struct rtnetlink_link link_rtnetlink_table[RTM_NR_MSGTYPES] =
650 {
651 	[RTM_GETLINK  - RTM_BASE] = { .dumpit = rtnetlink_dump_ifinfo },
652 	[RTM_SETLINK  - RTM_BASE] = { .doit   = do_setlink	      },
653 	[RTM_GETADDR  - RTM_BASE] = { .dumpit = rtnetlink_dump_all    },
654 	[RTM_GETROUTE - RTM_BASE] = { .dumpit = rtnetlink_dump_all    },
655 	[RTM_NEWNEIGH - RTM_BASE] = { .doit   = neigh_add	      },
656 	[RTM_DELNEIGH - RTM_BASE] = { .doit   = neigh_delete	      },
657 	[RTM_GETNEIGH - RTM_BASE] = { .dumpit = neigh_dump_info	      },
658 	[RTM_GETRULE  - RTM_BASE] = { .dumpit = rtnetlink_dump_all    },
659 };
660 
661 static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr)
662 {
663 	struct net_device *dev = ptr;
664 	switch (event) {
665 	case NETDEV_UNREGISTER:
666 		rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
667 		break;
668 	case NETDEV_REGISTER:
669 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
670 		break;
671 	case NETDEV_UP:
672 	case NETDEV_DOWN:
673 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
674 		break;
675 	case NETDEV_CHANGE:
676 	case NETDEV_GOING_DOWN:
677 		break;
678 	default:
679 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
680 		break;
681 	}
682 	return NOTIFY_DONE;
683 }
684 
685 static struct notifier_block rtnetlink_dev_notifier = {
686 	.notifier_call	= rtnetlink_event,
687 };
688 
689 void __init rtnetlink_init(void)
690 {
691 	int i;
692 
693 	rtattr_max = 0;
694 	for (i = 0; i < ARRAY_SIZE(rta_max); i++)
695 		if (rta_max[i] > rtattr_max)
696 			rtattr_max = rta_max[i];
697 	rta_buf = kmalloc(rtattr_max * sizeof(struct rtattr *), GFP_KERNEL);
698 	if (!rta_buf)
699 		panic("rtnetlink_init: cannot allocate rta_buf\n");
700 
701 	rtnl = netlink_kernel_create(NETLINK_ROUTE, rtnetlink_rcv);
702 	if (rtnl == NULL)
703 		panic("rtnetlink_init: cannot initialize rtnetlink\n");
704 	netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
705 	register_netdevice_notifier(&rtnetlink_dev_notifier);
706 	rtnetlink_links[PF_UNSPEC] = link_rtnetlink_table;
707 	rtnetlink_links[PF_PACKET] = link_rtnetlink_table;
708 }
709 
710 EXPORT_SYMBOL(__rta_fill);
711 EXPORT_SYMBOL(rtattr_strlcpy);
712 EXPORT_SYMBOL(rtattr_parse);
713 EXPORT_SYMBOL(rtnetlink_links);
714 EXPORT_SYMBOL(rtnetlink_put_metrics);
715 EXPORT_SYMBOL(rtnl);
716 EXPORT_SYMBOL(rtnl_lock);
717 EXPORT_SYMBOL(rtnl_lock_interruptible);
718 EXPORT_SYMBOL(rtnl_sem);
719 EXPORT_SYMBOL(rtnl_unlock);
720