xref: /linux/net/core/rtnetlink.c (revision 99b5aa3c10c7cff1e97239fda93649222fc12d25)
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/sched.h>
25 #include <linux/timer.h>
26 #include <linux/string.h>
27 #include <linux/sockios.h>
28 #include <linux/net.h>
29 #include <linux/fcntl.h>
30 #include <linux/mm.h>
31 #include <linux/slab.h>
32 #include <linux/interrupt.h>
33 #include <linux/capability.h>
34 #include <linux/skbuff.h>
35 #include <linux/init.h>
36 #include <linux/security.h>
37 #include <linux/mutex.h>
38 #include <linux/if_addr.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/netlink.h>
55 #ifdef CONFIG_NET_WIRELESS_RTNETLINK
56 #include <linux/wireless.h>
57 #include <net/iw_handler.h>
58 #endif	/* CONFIG_NET_WIRELESS_RTNETLINK */
59 
60 static DEFINE_MUTEX(rtnl_mutex);
61 static struct sock *rtnl;
62 
63 void rtnl_lock(void)
64 {
65 	mutex_lock(&rtnl_mutex);
66 }
67 
68 void __rtnl_unlock(void)
69 {
70 	mutex_unlock(&rtnl_mutex);
71 }
72 
73 void rtnl_unlock(void)
74 {
75 	mutex_unlock(&rtnl_mutex);
76 	if (rtnl && rtnl->sk_receive_queue.qlen)
77 		rtnl->sk_data_ready(rtnl, 0);
78 	netdev_run_todo();
79 }
80 
81 int rtnl_trylock(void)
82 {
83 	return mutex_trylock(&rtnl_mutex);
84 }
85 
86 int rtattr_parse(struct rtattr *tb[], int maxattr, struct rtattr *rta, int len)
87 {
88 	memset(tb, 0, sizeof(struct rtattr*)*maxattr);
89 
90 	while (RTA_OK(rta, len)) {
91 		unsigned flavor = rta->rta_type;
92 		if (flavor && flavor <= maxattr)
93 			tb[flavor-1] = rta;
94 		rta = RTA_NEXT(rta, len);
95 	}
96 	return 0;
97 }
98 
99 struct rtnetlink_link * rtnetlink_links[NPROTO];
100 
101 static const int rtm_min[RTM_NR_FAMILIES] =
102 {
103 	[RTM_FAM(RTM_NEWLINK)]      = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
104 	[RTM_FAM(RTM_NEWADDR)]      = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
105 	[RTM_FAM(RTM_NEWROUTE)]     = NLMSG_LENGTH(sizeof(struct rtmsg)),
106 	[RTM_FAM(RTM_NEWRULE)]      = NLMSG_LENGTH(sizeof(struct fib_rule_hdr)),
107 	[RTM_FAM(RTM_NEWQDISC)]     = NLMSG_LENGTH(sizeof(struct tcmsg)),
108 	[RTM_FAM(RTM_NEWTCLASS)]    = NLMSG_LENGTH(sizeof(struct tcmsg)),
109 	[RTM_FAM(RTM_NEWTFILTER)]   = NLMSG_LENGTH(sizeof(struct tcmsg)),
110 	[RTM_FAM(RTM_NEWACTION)]    = NLMSG_LENGTH(sizeof(struct tcamsg)),
111 	[RTM_FAM(RTM_GETMULTICAST)] = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
112 	[RTM_FAM(RTM_GETANYCAST)]   = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
113 };
114 
115 static const int rta_max[RTM_NR_FAMILIES] =
116 {
117 	[RTM_FAM(RTM_NEWLINK)]      = IFLA_MAX,
118 	[RTM_FAM(RTM_NEWADDR)]      = IFA_MAX,
119 	[RTM_FAM(RTM_NEWROUTE)]     = RTA_MAX,
120 	[RTM_FAM(RTM_NEWRULE)]      = FRA_MAX,
121 	[RTM_FAM(RTM_NEWQDISC)]     = TCA_MAX,
122 	[RTM_FAM(RTM_NEWTCLASS)]    = TCA_MAX,
123 	[RTM_FAM(RTM_NEWTFILTER)]   = TCA_MAX,
124 	[RTM_FAM(RTM_NEWACTION)]    = TCAA_MAX,
125 };
126 
127 void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
128 {
129 	struct rtattr *rta;
130 	int size = RTA_LENGTH(attrlen);
131 
132 	rta = (struct rtattr*)skb_put(skb, RTA_ALIGN(size));
133 	rta->rta_type = attrtype;
134 	rta->rta_len = size;
135 	memcpy(RTA_DATA(rta), data, attrlen);
136 	memset(RTA_DATA(rta) + attrlen, 0, RTA_ALIGN(size) - size);
137 }
138 
139 size_t rtattr_strlcpy(char *dest, const struct rtattr *rta, size_t size)
140 {
141 	size_t ret = RTA_PAYLOAD(rta);
142 	char *src = RTA_DATA(rta);
143 
144 	if (ret > 0 && src[ret - 1] == '\0')
145 		ret--;
146 	if (size > 0) {
147 		size_t len = (ret >= size) ? size - 1 : ret;
148 		memset(dest, 0, size);
149 		memcpy(dest, src, len);
150 	}
151 	return ret;
152 }
153 
154 int rtnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo)
155 {
156 	int err = 0;
157 
158 	NETLINK_CB(skb).dst_group = group;
159 	if (echo)
160 		atomic_inc(&skb->users);
161 	netlink_broadcast(rtnl, skb, pid, group, GFP_KERNEL);
162 	if (echo)
163 		err = netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
164 	return err;
165 }
166 
167 int rtnl_unicast(struct sk_buff *skb, u32 pid)
168 {
169 	return nlmsg_unicast(rtnl, skb, pid);
170 }
171 
172 int rtnl_notify(struct sk_buff *skb, u32 pid, u32 group,
173 		struct nlmsghdr *nlh, gfp_t flags)
174 {
175 	int report = 0;
176 
177 	if (nlh)
178 		report = nlmsg_report(nlh);
179 
180 	return nlmsg_notify(rtnl, skb, pid, group, report, flags);
181 }
182 
183 void rtnl_set_sk_err(u32 group, int error)
184 {
185 	netlink_set_err(rtnl, 0, group, error);
186 }
187 
188 int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics)
189 {
190 	struct nlattr *mx;
191 	int i, valid = 0;
192 
193 	mx = nla_nest_start(skb, RTA_METRICS);
194 	if (mx == NULL)
195 		return -ENOBUFS;
196 
197 	for (i = 0; i < RTAX_MAX; i++) {
198 		if (metrics[i]) {
199 			valid++;
200 			NLA_PUT_U32(skb, i+1, metrics[i]);
201 		}
202 	}
203 
204 	if (!valid) {
205 		nla_nest_cancel(skb, mx);
206 		return 0;
207 	}
208 
209 	return nla_nest_end(skb, mx);
210 
211 nla_put_failure:
212 	return nla_nest_cancel(skb, mx);
213 }
214 
215 int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id,
216 		       u32 ts, u32 tsage, long expires, u32 error)
217 {
218 	struct rta_cacheinfo ci = {
219 		.rta_lastuse = jiffies_to_clock_t(jiffies - dst->lastuse),
220 		.rta_used = dst->__use,
221 		.rta_clntref = atomic_read(&(dst->__refcnt)),
222 		.rta_error = error,
223 		.rta_id =  id,
224 		.rta_ts = ts,
225 		.rta_tsage = tsage,
226 	};
227 
228 	if (expires)
229 		ci.rta_expires = jiffies_to_clock_t(expires);
230 
231 	return nla_put(skb, RTA_CACHEINFO, sizeof(ci), &ci);
232 }
233 
234 EXPORT_SYMBOL_GPL(rtnl_put_cacheinfo);
235 
236 static void set_operstate(struct net_device *dev, unsigned char transition)
237 {
238 	unsigned char operstate = dev->operstate;
239 
240 	switch(transition) {
241 	case IF_OPER_UP:
242 		if ((operstate == IF_OPER_DORMANT ||
243 		     operstate == IF_OPER_UNKNOWN) &&
244 		    !netif_dormant(dev))
245 			operstate = IF_OPER_UP;
246 		break;
247 
248 	case IF_OPER_DORMANT:
249 		if (operstate == IF_OPER_UP ||
250 		    operstate == IF_OPER_UNKNOWN)
251 			operstate = IF_OPER_DORMANT;
252 		break;
253 	};
254 
255 	if (dev->operstate != operstate) {
256 		write_lock_bh(&dev_base_lock);
257 		dev->operstate = operstate;
258 		write_unlock_bh(&dev_base_lock);
259 		netdev_state_change(dev);
260 	}
261 }
262 
263 static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
264 				 struct net_device_stats *b)
265 {
266 	a->rx_packets = b->rx_packets;
267 	a->tx_packets = b->tx_packets;
268 	a->rx_bytes = b->rx_bytes;
269 	a->tx_bytes = b->tx_bytes;
270 	a->rx_errors = b->rx_errors;
271 	a->tx_errors = b->tx_errors;
272 	a->rx_dropped = b->rx_dropped;
273 	a->tx_dropped = b->tx_dropped;
274 
275 	a->multicast = b->multicast;
276 	a->collisions = b->collisions;
277 
278 	a->rx_length_errors = b->rx_length_errors;
279 	a->rx_over_errors = b->rx_over_errors;
280 	a->rx_crc_errors = b->rx_crc_errors;
281 	a->rx_frame_errors = b->rx_frame_errors;
282 	a->rx_fifo_errors = b->rx_fifo_errors;
283 	a->rx_missed_errors = b->rx_missed_errors;
284 
285 	a->tx_aborted_errors = b->tx_aborted_errors;
286 	a->tx_carrier_errors = b->tx_carrier_errors;
287 	a->tx_fifo_errors = b->tx_fifo_errors;
288 	a->tx_heartbeat_errors = b->tx_heartbeat_errors;
289 	a->tx_window_errors = b->tx_window_errors;
290 
291 	a->rx_compressed = b->rx_compressed;
292 	a->tx_compressed = b->tx_compressed;
293 };
294 
295 static inline size_t if_nlmsg_size(int iwbuflen)
296 {
297 	return NLMSG_ALIGN(sizeof(struct ifinfomsg))
298 	       + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
299 	       + nla_total_size(IFNAMSIZ) /* IFLA_QDISC */
300 	       + nla_total_size(sizeof(struct rtnl_link_ifmap))
301 	       + nla_total_size(sizeof(struct rtnl_link_stats))
302 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
303 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_BROADCAST */
304 	       + nla_total_size(4) /* IFLA_TXQLEN */
305 	       + nla_total_size(4) /* IFLA_WEIGHT */
306 	       + nla_total_size(4) /* IFLA_MTU */
307 	       + nla_total_size(4) /* IFLA_LINK */
308 	       + nla_total_size(4) /* IFLA_MASTER */
309 	       + nla_total_size(1) /* IFLA_OPERSTATE */
310 	       + nla_total_size(1) /* IFLA_LINKMODE */
311 	       + nla_total_size(iwbuflen);
312 }
313 
314 static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
315 			    void *iwbuf, int iwbuflen, int type, u32 pid,
316 			    u32 seq, u32 change, unsigned int flags)
317 {
318 	struct ifinfomsg *ifm;
319 	struct nlmsghdr *nlh;
320 
321 	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ifm), flags);
322 	if (nlh == NULL)
323 		return -ENOBUFS;
324 
325 	ifm = nlmsg_data(nlh);
326 	ifm->ifi_family = AF_UNSPEC;
327 	ifm->__ifi_pad = 0;
328 	ifm->ifi_type = dev->type;
329 	ifm->ifi_index = dev->ifindex;
330 	ifm->ifi_flags = dev_get_flags(dev);
331 	ifm->ifi_change = change;
332 
333 	NLA_PUT_STRING(skb, IFLA_IFNAME, dev->name);
334 	NLA_PUT_U32(skb, IFLA_TXQLEN, dev->tx_queue_len);
335 	NLA_PUT_U32(skb, IFLA_WEIGHT, dev->weight);
336 	NLA_PUT_U8(skb, IFLA_OPERSTATE,
337 		   netif_running(dev) ? dev->operstate : IF_OPER_DOWN);
338 	NLA_PUT_U8(skb, IFLA_LINKMODE, dev->link_mode);
339 	NLA_PUT_U32(skb, IFLA_MTU, dev->mtu);
340 
341 	if (dev->ifindex != dev->iflink)
342 		NLA_PUT_U32(skb, IFLA_LINK, dev->iflink);
343 
344 	if (dev->master)
345 		NLA_PUT_U32(skb, IFLA_MASTER, dev->master->ifindex);
346 
347 	if (dev->qdisc_sleeping)
348 		NLA_PUT_STRING(skb, IFLA_QDISC, dev->qdisc_sleeping->ops->id);
349 
350 	if (1) {
351 		struct rtnl_link_ifmap map = {
352 			.mem_start   = dev->mem_start,
353 			.mem_end     = dev->mem_end,
354 			.base_addr   = dev->base_addr,
355 			.irq         = dev->irq,
356 			.dma         = dev->dma,
357 			.port        = dev->if_port,
358 		};
359 		NLA_PUT(skb, IFLA_MAP, sizeof(map), &map);
360 	}
361 
362 	if (dev->addr_len) {
363 		NLA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr);
364 		NLA_PUT(skb, IFLA_BROADCAST, dev->addr_len, dev->broadcast);
365 	}
366 
367 	if (dev->get_stats) {
368 		struct net_device_stats *stats = dev->get_stats(dev);
369 		if (stats) {
370 			struct nlattr *attr;
371 
372 			attr = nla_reserve(skb, IFLA_STATS,
373 					   sizeof(struct rtnl_link_stats));
374 			if (attr == NULL)
375 				goto nla_put_failure;
376 
377 			copy_rtnl_link_stats(nla_data(attr), stats);
378 		}
379 	}
380 
381 	if (iwbuf)
382 		NLA_PUT(skb, IFLA_WIRELESS, iwbuflen, iwbuf);
383 
384 	return nlmsg_end(skb, nlh);
385 
386 nla_put_failure:
387 	return nlmsg_cancel(skb, nlh);
388 }
389 
390 static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
391 {
392 	int idx;
393 	int s_idx = cb->args[0];
394 	struct net_device *dev;
395 
396 	read_lock(&dev_base_lock);
397 	for (dev=dev_base, idx=0; dev; dev = dev->next, idx++) {
398 		if (idx < s_idx)
399 			continue;
400 		if (rtnl_fill_ifinfo(skb, dev, NULL, 0, RTM_NEWLINK,
401 				     NETLINK_CB(cb->skb).pid,
402 				     cb->nlh->nlmsg_seq, 0, NLM_F_MULTI) <= 0)
403 			break;
404 	}
405 	read_unlock(&dev_base_lock);
406 	cb->args[0] = idx;
407 
408 	return skb->len;
409 }
410 
411 static struct nla_policy ifla_policy[IFLA_MAX+1] __read_mostly = {
412 	[IFLA_IFNAME]		= { .type = NLA_STRING, .len = IFNAMSIZ-1 },
413 	[IFLA_MAP]		= { .len = sizeof(struct rtnl_link_ifmap) },
414 	[IFLA_MTU]		= { .type = NLA_U32 },
415 	[IFLA_TXQLEN]		= { .type = NLA_U32 },
416 	[IFLA_WEIGHT]		= { .type = NLA_U32 },
417 	[IFLA_OPERSTATE]	= { .type = NLA_U8 },
418 	[IFLA_LINKMODE]		= { .type = NLA_U8 },
419 };
420 
421 static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
422 {
423 	struct ifinfomsg *ifm;
424 	struct net_device *dev;
425 	int err, send_addr_notify = 0, modified = 0;
426 	struct nlattr *tb[IFLA_MAX+1];
427 	char ifname[IFNAMSIZ];
428 
429 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
430 	if (err < 0)
431 		goto errout;
432 
433 	if (tb[IFLA_IFNAME])
434 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
435 	else
436 		ifname[0] = '\0';
437 
438 	err = -EINVAL;
439 	ifm = nlmsg_data(nlh);
440 	if (ifm->ifi_index >= 0)
441 		dev = dev_get_by_index(ifm->ifi_index);
442 	else if (tb[IFLA_IFNAME])
443 		dev = dev_get_by_name(ifname);
444 	else
445 		goto errout;
446 
447 	if (dev == NULL) {
448 		err = -ENODEV;
449 		goto errout;
450 	}
451 
452 	if (tb[IFLA_ADDRESS] &&
453 	    nla_len(tb[IFLA_ADDRESS]) < dev->addr_len)
454 		goto errout_dev;
455 
456 	if (tb[IFLA_BROADCAST] &&
457 	    nla_len(tb[IFLA_BROADCAST]) < dev->addr_len)
458 		goto errout_dev;
459 
460 	if (tb[IFLA_MAP]) {
461 		struct rtnl_link_ifmap *u_map;
462 		struct ifmap k_map;
463 
464 		if (!dev->set_config) {
465 			err = -EOPNOTSUPP;
466 			goto errout_dev;
467 		}
468 
469 		if (!netif_device_present(dev)) {
470 			err = -ENODEV;
471 			goto errout_dev;
472 		}
473 
474 		u_map = nla_data(tb[IFLA_MAP]);
475 		k_map.mem_start = (unsigned long) u_map->mem_start;
476 		k_map.mem_end = (unsigned long) u_map->mem_end;
477 		k_map.base_addr = (unsigned short) u_map->base_addr;
478 		k_map.irq = (unsigned char) u_map->irq;
479 		k_map.dma = (unsigned char) u_map->dma;
480 		k_map.port = (unsigned char) u_map->port;
481 
482 		err = dev->set_config(dev, &k_map);
483 		if (err < 0)
484 			goto errout_dev;
485 
486 		modified = 1;
487 	}
488 
489 	if (tb[IFLA_ADDRESS]) {
490 		struct sockaddr *sa;
491 		int len;
492 
493 		if (!dev->set_mac_address) {
494 			err = -EOPNOTSUPP;
495 			goto errout_dev;
496 		}
497 
498 		if (!netif_device_present(dev)) {
499 			err = -ENODEV;
500 			goto errout_dev;
501 		}
502 
503 		len = sizeof(sa_family_t) + dev->addr_len;
504 		sa = kmalloc(len, GFP_KERNEL);
505 		if (!sa) {
506 			err = -ENOMEM;
507 			goto errout_dev;
508 		}
509 		sa->sa_family = dev->type;
510 		memcpy(sa->sa_data, nla_data(tb[IFLA_ADDRESS]),
511 		       dev->addr_len);
512 		err = dev->set_mac_address(dev, sa);
513 		kfree(sa);
514 		if (err)
515 			goto errout_dev;
516 		send_addr_notify = 1;
517 		modified = 1;
518 	}
519 
520 	if (tb[IFLA_MTU]) {
521 		err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
522 		if (err < 0)
523 			goto errout_dev;
524 		modified = 1;
525 	}
526 
527 	/*
528 	 * Interface selected by interface index but interface
529 	 * name provided implies that a name change has been
530 	 * requested.
531 	 */
532 	if (ifm->ifi_index >= 0 && ifname[0]) {
533 		err = dev_change_name(dev, ifname);
534 		if (err < 0)
535 			goto errout_dev;
536 		modified = 1;
537 	}
538 
539 #ifdef CONFIG_NET_WIRELESS_RTNETLINK
540 	if (tb[IFLA_WIRELESS]) {
541 		/* Call Wireless Extensions.
542 		 * Various stuff checked in there... */
543 		err = wireless_rtnetlink_set(dev, nla_data(tb[IFLA_WIRELESS]),
544 					     nla_len(tb[IFLA_WIRELESS]));
545 		if (err < 0)
546 			goto errout_dev;
547 	}
548 #endif	/* CONFIG_NET_WIRELESS_RTNETLINK */
549 
550 	if (tb[IFLA_BROADCAST]) {
551 		nla_memcpy(dev->broadcast, tb[IFLA_BROADCAST], dev->addr_len);
552 		send_addr_notify = 1;
553 	}
554 
555 
556 	if (ifm->ifi_flags)
557 		dev_change_flags(dev, ifm->ifi_flags);
558 
559 	if (tb[IFLA_TXQLEN])
560 		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
561 
562 	if (tb[IFLA_WEIGHT])
563 		dev->weight = nla_get_u32(tb[IFLA_WEIGHT]);
564 
565 	if (tb[IFLA_OPERSTATE])
566 		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
567 
568 	if (tb[IFLA_LINKMODE]) {
569 		write_lock_bh(&dev_base_lock);
570 		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
571 		write_unlock_bh(&dev_base_lock);
572 	}
573 
574 	err = 0;
575 
576 errout_dev:
577 	if (err < 0 && modified && net_ratelimit())
578 		printk(KERN_WARNING "A link change request failed with "
579 		       "some changes comitted already. Interface %s may "
580 		       "have been left with an inconsistent configuration, "
581 		       "please check.\n", dev->name);
582 
583 	if (send_addr_notify)
584 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
585 
586 	dev_put(dev);
587 errout:
588 	return err;
589 }
590 
591 static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
592 {
593 	struct ifinfomsg *ifm;
594 	struct nlattr *tb[IFLA_MAX+1];
595 	struct net_device *dev = NULL;
596 	struct sk_buff *nskb;
597 	char *iw_buf = NULL, *iw = NULL;
598 	int iw_buf_len = 0;
599 	int err;
600 
601 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
602 	if (err < 0)
603 		return err;
604 
605 	ifm = nlmsg_data(nlh);
606 	if (ifm->ifi_index >= 0) {
607 		dev = dev_get_by_index(ifm->ifi_index);
608 		if (dev == NULL)
609 			return -ENODEV;
610 	} else
611 		return -EINVAL;
612 
613 
614 #ifdef CONFIG_NET_WIRELESS_RTNETLINK
615 	if (tb[IFLA_WIRELESS]) {
616 		/* Call Wireless Extensions. We need to know the size before
617 		 * we can alloc. Various stuff checked in there... */
618 		err = wireless_rtnetlink_get(dev, nla_data(tb[IFLA_WIRELESS]),
619 					     nla_len(tb[IFLA_WIRELESS]),
620 					     &iw_buf, &iw_buf_len);
621 		if (err < 0)
622 			goto errout;
623 
624 		iw += IW_EV_POINT_OFF;
625 	}
626 #endif	/* CONFIG_NET_WIRELESS_RTNETLINK */
627 
628 	nskb = nlmsg_new(if_nlmsg_size(iw_buf_len), GFP_KERNEL);
629 	if (nskb == NULL) {
630 		err = -ENOBUFS;
631 		goto errout;
632 	}
633 
634 	err = rtnl_fill_ifinfo(nskb, dev, iw, iw_buf_len, RTM_NEWLINK,
635 			       NETLINK_CB(skb).pid, nlh->nlmsg_seq, 0, 0);
636 	/* failure impilies BUG in if_nlmsg_size or wireless_rtnetlink_get */
637 	BUG_ON(err < 0);
638 
639 	err = rtnl_unicast(nskb, NETLINK_CB(skb).pid);
640 errout:
641 	kfree(iw_buf);
642 	dev_put(dev);
643 
644 	return err;
645 }
646 
647 static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
648 {
649 	int idx;
650 	int s_idx = cb->family;
651 
652 	if (s_idx == 0)
653 		s_idx = 1;
654 	for (idx=1; idx<NPROTO; idx++) {
655 		int type = cb->nlh->nlmsg_type-RTM_BASE;
656 		if (idx < s_idx || idx == PF_PACKET)
657 			continue;
658 		if (rtnetlink_links[idx] == NULL ||
659 		    rtnetlink_links[idx][type].dumpit == NULL)
660 			continue;
661 		if (idx > s_idx)
662 			memset(&cb->args[0], 0, sizeof(cb->args));
663 		if (rtnetlink_links[idx][type].dumpit(skb, cb))
664 			break;
665 	}
666 	cb->family = idx;
667 
668 	return skb->len;
669 }
670 
671 void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change)
672 {
673 	struct sk_buff *skb;
674 	int err = -ENOBUFS;
675 
676 	skb = nlmsg_new(if_nlmsg_size(0), GFP_KERNEL);
677 	if (skb == NULL)
678 		goto errout;
679 
680 	err = rtnl_fill_ifinfo(skb, dev, NULL, 0, type, 0, 0, change, 0);
681 	/* failure implies BUG in if_nlmsg_size() */
682 	BUG_ON(err < 0);
683 
684 	err = rtnl_notify(skb, 0, RTNLGRP_LINK, NULL, GFP_KERNEL);
685 errout:
686 	if (err < 0)
687 		rtnl_set_sk_err(RTNLGRP_LINK, err);
688 }
689 
690 /* Protected by RTNL sempahore.  */
691 static struct rtattr **rta_buf;
692 static int rtattr_max;
693 
694 /* Process one rtnetlink message. */
695 
696 static __inline__ int
697 rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp)
698 {
699 	struct rtnetlink_link *link;
700 	struct rtnetlink_link *link_tab;
701 	int sz_idx, kind;
702 	int min_len;
703 	int family;
704 	int type;
705 	int err;
706 
707 	/* Only requests are handled by kernel now */
708 	if (!(nlh->nlmsg_flags&NLM_F_REQUEST))
709 		return 0;
710 
711 	type = nlh->nlmsg_type;
712 
713 	/* A control message: ignore them */
714 	if (type < RTM_BASE)
715 		return 0;
716 
717 	/* Unknown message: reply with EINVAL */
718 	if (type > RTM_MAX)
719 		goto err_inval;
720 
721 	type -= RTM_BASE;
722 
723 	/* All the messages must have at least 1 byte length */
724 	if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct rtgenmsg)))
725 		return 0;
726 
727 	family = ((struct rtgenmsg*)NLMSG_DATA(nlh))->rtgen_family;
728 	if (family >= NPROTO) {
729 		*errp = -EAFNOSUPPORT;
730 		return -1;
731 	}
732 
733 	link_tab = rtnetlink_links[family];
734 	if (link_tab == NULL)
735 		link_tab = rtnetlink_links[PF_UNSPEC];
736 	link = &link_tab[type];
737 
738 	sz_idx = type>>2;
739 	kind = type&3;
740 
741 	if (kind != 2 && security_netlink_recv(skb, CAP_NET_ADMIN)) {
742 		*errp = -EPERM;
743 		return -1;
744 	}
745 
746 	if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
747 		if (link->dumpit == NULL)
748 			link = &(rtnetlink_links[PF_UNSPEC][type]);
749 
750 		if (link->dumpit == NULL)
751 			goto err_inval;
752 
753 		if ((*errp = netlink_dump_start(rtnl, skb, nlh,
754 						link->dumpit, NULL)) != 0) {
755 			return -1;
756 		}
757 
758 		netlink_queue_skip(nlh, skb);
759 		return -1;
760 	}
761 
762 	memset(rta_buf, 0, (rtattr_max * sizeof(struct rtattr *)));
763 
764 	min_len = rtm_min[sz_idx];
765 	if (nlh->nlmsg_len < min_len)
766 		goto err_inval;
767 
768 	if (nlh->nlmsg_len > min_len) {
769 		int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
770 		struct rtattr *attr = (void*)nlh + NLMSG_ALIGN(min_len);
771 
772 		while (RTA_OK(attr, attrlen)) {
773 			unsigned flavor = attr->rta_type;
774 			if (flavor) {
775 				if (flavor > rta_max[sz_idx])
776 					goto err_inval;
777 				rta_buf[flavor-1] = attr;
778 			}
779 			attr = RTA_NEXT(attr, attrlen);
780 		}
781 	}
782 
783 	if (link->doit == NULL)
784 		link = &(rtnetlink_links[PF_UNSPEC][type]);
785 	if (link->doit == NULL)
786 		goto err_inval;
787 	err = link->doit(skb, nlh, (void *)&rta_buf[0]);
788 
789 	*errp = err;
790 	return err;
791 
792 err_inval:
793 	*errp = -EINVAL;
794 	return -1;
795 }
796 
797 static void rtnetlink_rcv(struct sock *sk, int len)
798 {
799 	unsigned int qlen = 0;
800 
801 	do {
802 		mutex_lock(&rtnl_mutex);
803 		netlink_run_queue(sk, &qlen, &rtnetlink_rcv_msg);
804 		mutex_unlock(&rtnl_mutex);
805 
806 		netdev_run_todo();
807 	} while (qlen);
808 }
809 
810 static struct rtnetlink_link link_rtnetlink_table[RTM_NR_MSGTYPES] =
811 {
812 	[RTM_GETLINK     - RTM_BASE] = { .doit   = rtnl_getlink,
813 					 .dumpit = rtnl_dump_ifinfo	 },
814 	[RTM_SETLINK     - RTM_BASE] = { .doit   = rtnl_setlink		 },
815 	[RTM_GETADDR     - RTM_BASE] = { .dumpit = rtnl_dump_all	 },
816 	[RTM_GETROUTE    - RTM_BASE] = { .dumpit = rtnl_dump_all	 },
817 	[RTM_NEWNEIGH    - RTM_BASE] = { .doit   = neigh_add		 },
818 	[RTM_DELNEIGH    - RTM_BASE] = { .doit   = neigh_delete		 },
819 	[RTM_GETNEIGH    - RTM_BASE] = { .dumpit = neigh_dump_info	 },
820 #ifdef CONFIG_FIB_RULES
821 	[RTM_NEWRULE     - RTM_BASE] = { .doit   = fib_nl_newrule	 },
822 	[RTM_DELRULE     - RTM_BASE] = { .doit   = fib_nl_delrule	 },
823 #endif
824 	[RTM_GETRULE     - RTM_BASE] = { .dumpit = rtnl_dump_all	 },
825 	[RTM_GETNEIGHTBL - RTM_BASE] = { .dumpit = neightbl_dump_info	 },
826 	[RTM_SETNEIGHTBL - RTM_BASE] = { .doit   = neightbl_set		 },
827 };
828 
829 static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr)
830 {
831 	struct net_device *dev = ptr;
832 	switch (event) {
833 	case NETDEV_UNREGISTER:
834 		rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
835 		break;
836 	case NETDEV_REGISTER:
837 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
838 		break;
839 	case NETDEV_UP:
840 	case NETDEV_DOWN:
841 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
842 		break;
843 	case NETDEV_CHANGE:
844 	case NETDEV_GOING_DOWN:
845 		break;
846 	default:
847 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
848 		break;
849 	}
850 	return NOTIFY_DONE;
851 }
852 
853 static struct notifier_block rtnetlink_dev_notifier = {
854 	.notifier_call	= rtnetlink_event,
855 };
856 
857 void __init rtnetlink_init(void)
858 {
859 	int i;
860 
861 	rtattr_max = 0;
862 	for (i = 0; i < ARRAY_SIZE(rta_max); i++)
863 		if (rta_max[i] > rtattr_max)
864 			rtattr_max = rta_max[i];
865 	rta_buf = kmalloc(rtattr_max * sizeof(struct rtattr *), GFP_KERNEL);
866 	if (!rta_buf)
867 		panic("rtnetlink_init: cannot allocate rta_buf\n");
868 
869 	rtnl = netlink_kernel_create(NETLINK_ROUTE, RTNLGRP_MAX, rtnetlink_rcv,
870 	                             THIS_MODULE);
871 	if (rtnl == NULL)
872 		panic("rtnetlink_init: cannot initialize rtnetlink\n");
873 	netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
874 	register_netdevice_notifier(&rtnetlink_dev_notifier);
875 	rtnetlink_links[PF_UNSPEC] = link_rtnetlink_table;
876 	rtnetlink_links[PF_PACKET] = link_rtnetlink_table;
877 }
878 
879 EXPORT_SYMBOL(__rta_fill);
880 EXPORT_SYMBOL(rtattr_strlcpy);
881 EXPORT_SYMBOL(rtattr_parse);
882 EXPORT_SYMBOL(rtnetlink_links);
883 EXPORT_SYMBOL(rtnetlink_put_metrics);
884 EXPORT_SYMBOL(rtnl_lock);
885 EXPORT_SYMBOL(rtnl_trylock);
886 EXPORT_SYMBOL(rtnl_unlock);
887 EXPORT_SYMBOL(rtnl_unicast);
888 EXPORT_SYMBOL(rtnl_notify);
889 EXPORT_SYMBOL(rtnl_set_sk_err);
890