xref: /linux/net/core/rtnetlink.c (revision 7f3edee81fbd49114c28057512906f169caa0bed)
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 static struct sock *rtnl;
64 
65 void rtnl_lock(void)
66 {
67 	mutex_lock(&rtnl_mutex);
68 }
69 
70 void __rtnl_unlock(void)
71 {
72 	mutex_unlock(&rtnl_mutex);
73 }
74 
75 void rtnl_unlock(void)
76 {
77 	mutex_unlock(&rtnl_mutex);
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 int __rtattr_parse_nested_compat(struct rtattr *tb[], int maxattr,
100 				 struct rtattr *rta, int len)
101 {
102 	if (RTA_PAYLOAD(rta) < len)
103 		return -1;
104 	if (RTA_PAYLOAD(rta) >= RTA_ALIGN(len) + sizeof(struct rtattr)) {
105 		rta = RTA_DATA(rta) + RTA_ALIGN(len);
106 		return rtattr_parse_nested(tb, maxattr, rta);
107 	}
108 	memset(tb, 0, sizeof(struct rtattr *) * maxattr);
109 	return 0;
110 }
111 
112 static struct rtnl_link *rtnl_msg_handlers[NPROTO];
113 
114 static inline int rtm_msgindex(int msgtype)
115 {
116 	int msgindex = msgtype - RTM_BASE;
117 
118 	/*
119 	 * msgindex < 0 implies someone tried to register a netlink
120 	 * control code. msgindex >= RTM_NR_MSGTYPES may indicate that
121 	 * the message type has not been added to linux/rtnetlink.h
122 	 */
123 	BUG_ON(msgindex < 0 || msgindex >= RTM_NR_MSGTYPES);
124 
125 	return msgindex;
126 }
127 
128 static rtnl_doit_func rtnl_get_doit(int protocol, int msgindex)
129 {
130 	struct rtnl_link *tab;
131 
132 	tab = rtnl_msg_handlers[protocol];
133 	if (tab == NULL || tab[msgindex].doit == NULL)
134 		tab = rtnl_msg_handlers[PF_UNSPEC];
135 
136 	return tab ? tab[msgindex].doit : NULL;
137 }
138 
139 static rtnl_dumpit_func rtnl_get_dumpit(int protocol, int msgindex)
140 {
141 	struct rtnl_link *tab;
142 
143 	tab = rtnl_msg_handlers[protocol];
144 	if (tab == NULL || tab[msgindex].dumpit == NULL)
145 		tab = rtnl_msg_handlers[PF_UNSPEC];
146 
147 	return tab ? tab[msgindex].dumpit : NULL;
148 }
149 
150 /**
151  * __rtnl_register - Register a rtnetlink message type
152  * @protocol: Protocol family or PF_UNSPEC
153  * @msgtype: rtnetlink message type
154  * @doit: Function pointer called for each request message
155  * @dumpit: Function pointer called for each dump request (NLM_F_DUMP) message
156  *
157  * Registers the specified function pointers (at least one of them has
158  * to be non-NULL) to be called whenever a request message for the
159  * specified protocol family and message type is received.
160  *
161  * The special protocol family PF_UNSPEC may be used to define fallback
162  * function pointers for the case when no entry for the specific protocol
163  * family exists.
164  *
165  * Returns 0 on success or a negative error code.
166  */
167 int __rtnl_register(int protocol, int msgtype,
168 		    rtnl_doit_func doit, rtnl_dumpit_func dumpit)
169 {
170 	struct rtnl_link *tab;
171 	int msgindex;
172 
173 	BUG_ON(protocol < 0 || protocol >= NPROTO);
174 	msgindex = rtm_msgindex(msgtype);
175 
176 	tab = rtnl_msg_handlers[protocol];
177 	if (tab == NULL) {
178 		tab = kcalloc(RTM_NR_MSGTYPES, sizeof(*tab), GFP_KERNEL);
179 		if (tab == NULL)
180 			return -ENOBUFS;
181 
182 		rtnl_msg_handlers[protocol] = tab;
183 	}
184 
185 	if (doit)
186 		tab[msgindex].doit = doit;
187 
188 	if (dumpit)
189 		tab[msgindex].dumpit = dumpit;
190 
191 	return 0;
192 }
193 
194 EXPORT_SYMBOL_GPL(__rtnl_register);
195 
196 /**
197  * rtnl_register - Register a rtnetlink message type
198  *
199  * Identical to __rtnl_register() but panics on failure. This is useful
200  * as failure of this function is very unlikely, it can only happen due
201  * to lack of memory when allocating the chain to store all message
202  * handlers for a protocol. Meant for use in init functions where lack
203  * of memory implies no sense in continueing.
204  */
205 void rtnl_register(int protocol, int msgtype,
206 		   rtnl_doit_func doit, rtnl_dumpit_func dumpit)
207 {
208 	if (__rtnl_register(protocol, msgtype, doit, dumpit) < 0)
209 		panic("Unable to register rtnetlink message handler, "
210 		      "protocol = %d, message type = %d\n",
211 		      protocol, msgtype);
212 }
213 
214 EXPORT_SYMBOL_GPL(rtnl_register);
215 
216 /**
217  * rtnl_unregister - Unregister a rtnetlink message type
218  * @protocol: Protocol family or PF_UNSPEC
219  * @msgtype: rtnetlink message type
220  *
221  * Returns 0 on success or a negative error code.
222  */
223 int rtnl_unregister(int protocol, int msgtype)
224 {
225 	int msgindex;
226 
227 	BUG_ON(protocol < 0 || protocol >= NPROTO);
228 	msgindex = rtm_msgindex(msgtype);
229 
230 	if (rtnl_msg_handlers[protocol] == NULL)
231 		return -ENOENT;
232 
233 	rtnl_msg_handlers[protocol][msgindex].doit = NULL;
234 	rtnl_msg_handlers[protocol][msgindex].dumpit = NULL;
235 
236 	return 0;
237 }
238 
239 EXPORT_SYMBOL_GPL(rtnl_unregister);
240 
241 /**
242  * rtnl_unregister_all - Unregister all rtnetlink message type of a protocol
243  * @protocol : Protocol family or PF_UNSPEC
244  *
245  * Identical to calling rtnl_unregster() for all registered message types
246  * of a certain protocol family.
247  */
248 void rtnl_unregister_all(int protocol)
249 {
250 	BUG_ON(protocol < 0 || protocol >= NPROTO);
251 
252 	kfree(rtnl_msg_handlers[protocol]);
253 	rtnl_msg_handlers[protocol] = NULL;
254 }
255 
256 EXPORT_SYMBOL_GPL(rtnl_unregister_all);
257 
258 static LIST_HEAD(link_ops);
259 
260 /**
261  * __rtnl_link_register - Register rtnl_link_ops with rtnetlink.
262  * @ops: struct rtnl_link_ops * to register
263  *
264  * The caller must hold the rtnl_mutex. This function should be used
265  * by drivers that create devices during module initialization. It
266  * must be called before registering the devices.
267  *
268  * Returns 0 on success or a negative error code.
269  */
270 int __rtnl_link_register(struct rtnl_link_ops *ops)
271 {
272 	if (!ops->dellink)
273 		ops->dellink = unregister_netdevice;
274 
275 	list_add_tail(&ops->list, &link_ops);
276 	return 0;
277 }
278 
279 EXPORT_SYMBOL_GPL(__rtnl_link_register);
280 
281 /**
282  * rtnl_link_register - Register rtnl_link_ops with rtnetlink.
283  * @ops: struct rtnl_link_ops * to register
284  *
285  * Returns 0 on success or a negative error code.
286  */
287 int rtnl_link_register(struct rtnl_link_ops *ops)
288 {
289 	int err;
290 
291 	rtnl_lock();
292 	err = __rtnl_link_register(ops);
293 	rtnl_unlock();
294 	return err;
295 }
296 
297 EXPORT_SYMBOL_GPL(rtnl_link_register);
298 
299 /**
300  * __rtnl_link_unregister - Unregister rtnl_link_ops from rtnetlink.
301  * @ops: struct rtnl_link_ops * to unregister
302  *
303  * The caller must hold the rtnl_mutex.
304  */
305 void __rtnl_link_unregister(struct rtnl_link_ops *ops)
306 {
307 	struct net_device *dev, *n;
308 	struct net *net;
309 
310 	for_each_net(net) {
311 restart:
312 		for_each_netdev_safe(net, dev, n) {
313 			if (dev->rtnl_link_ops == ops) {
314 				ops->dellink(dev);
315 				goto restart;
316 			}
317 		}
318 	}
319 	list_del(&ops->list);
320 }
321 
322 EXPORT_SYMBOL_GPL(__rtnl_link_unregister);
323 
324 /**
325  * rtnl_link_unregister - Unregister rtnl_link_ops from rtnetlink.
326  * @ops: struct rtnl_link_ops * to unregister
327  */
328 void rtnl_link_unregister(struct rtnl_link_ops *ops)
329 {
330 	rtnl_lock();
331 	__rtnl_link_unregister(ops);
332 	rtnl_unlock();
333 }
334 
335 EXPORT_SYMBOL_GPL(rtnl_link_unregister);
336 
337 static const struct rtnl_link_ops *rtnl_link_ops_get(const char *kind)
338 {
339 	const struct rtnl_link_ops *ops;
340 
341 	list_for_each_entry(ops, &link_ops, list) {
342 		if (!strcmp(ops->kind, kind))
343 			return ops;
344 	}
345 	return NULL;
346 }
347 
348 static size_t rtnl_link_get_size(const struct net_device *dev)
349 {
350 	const struct rtnl_link_ops *ops = dev->rtnl_link_ops;
351 	size_t size;
352 
353 	if (!ops)
354 		return 0;
355 
356 	size = nlmsg_total_size(sizeof(struct nlattr)) + /* IFLA_LINKINFO */
357 	       nlmsg_total_size(strlen(ops->kind) + 1);	 /* IFLA_INFO_KIND */
358 
359 	if (ops->get_size)
360 		/* IFLA_INFO_DATA + nested data */
361 		size += nlmsg_total_size(sizeof(struct nlattr)) +
362 			ops->get_size(dev);
363 
364 	if (ops->get_xstats_size)
365 		size += ops->get_xstats_size(dev);	/* IFLA_INFO_XSTATS */
366 
367 	return size;
368 }
369 
370 static int rtnl_link_fill(struct sk_buff *skb, const struct net_device *dev)
371 {
372 	const struct rtnl_link_ops *ops = dev->rtnl_link_ops;
373 	struct nlattr *linkinfo, *data;
374 	int err = -EMSGSIZE;
375 
376 	linkinfo = nla_nest_start(skb, IFLA_LINKINFO);
377 	if (linkinfo == NULL)
378 		goto out;
379 
380 	if (nla_put_string(skb, IFLA_INFO_KIND, ops->kind) < 0)
381 		goto err_cancel_link;
382 	if (ops->fill_xstats) {
383 		err = ops->fill_xstats(skb, dev);
384 		if (err < 0)
385 			goto err_cancel_link;
386 	}
387 	if (ops->fill_info) {
388 		data = nla_nest_start(skb, IFLA_INFO_DATA);
389 		if (data == NULL)
390 			goto err_cancel_link;
391 		err = ops->fill_info(skb, dev);
392 		if (err < 0)
393 			goto err_cancel_data;
394 		nla_nest_end(skb, data);
395 	}
396 
397 	nla_nest_end(skb, linkinfo);
398 	return 0;
399 
400 err_cancel_data:
401 	nla_nest_cancel(skb, data);
402 err_cancel_link:
403 	nla_nest_cancel(skb, linkinfo);
404 out:
405 	return err;
406 }
407 
408 static const int rtm_min[RTM_NR_FAMILIES] =
409 {
410 	[RTM_FAM(RTM_NEWLINK)]      = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
411 	[RTM_FAM(RTM_NEWADDR)]      = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
412 	[RTM_FAM(RTM_NEWROUTE)]     = NLMSG_LENGTH(sizeof(struct rtmsg)),
413 	[RTM_FAM(RTM_NEWRULE)]      = NLMSG_LENGTH(sizeof(struct fib_rule_hdr)),
414 	[RTM_FAM(RTM_NEWQDISC)]     = NLMSG_LENGTH(sizeof(struct tcmsg)),
415 	[RTM_FAM(RTM_NEWTCLASS)]    = NLMSG_LENGTH(sizeof(struct tcmsg)),
416 	[RTM_FAM(RTM_NEWTFILTER)]   = NLMSG_LENGTH(sizeof(struct tcmsg)),
417 	[RTM_FAM(RTM_NEWACTION)]    = NLMSG_LENGTH(sizeof(struct tcamsg)),
418 	[RTM_FAM(RTM_GETMULTICAST)] = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
419 	[RTM_FAM(RTM_GETANYCAST)]   = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
420 };
421 
422 static const int rta_max[RTM_NR_FAMILIES] =
423 {
424 	[RTM_FAM(RTM_NEWLINK)]      = IFLA_MAX,
425 	[RTM_FAM(RTM_NEWADDR)]      = IFA_MAX,
426 	[RTM_FAM(RTM_NEWROUTE)]     = RTA_MAX,
427 	[RTM_FAM(RTM_NEWRULE)]      = FRA_MAX,
428 	[RTM_FAM(RTM_NEWQDISC)]     = TCA_MAX,
429 	[RTM_FAM(RTM_NEWTCLASS)]    = TCA_MAX,
430 	[RTM_FAM(RTM_NEWTFILTER)]   = TCA_MAX,
431 	[RTM_FAM(RTM_NEWACTION)]    = TCAA_MAX,
432 };
433 
434 void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
435 {
436 	struct rtattr *rta;
437 	int size = RTA_LENGTH(attrlen);
438 
439 	rta = (struct rtattr*)skb_put(skb, RTA_ALIGN(size));
440 	rta->rta_type = attrtype;
441 	rta->rta_len = size;
442 	memcpy(RTA_DATA(rta), data, attrlen);
443 	memset(RTA_DATA(rta) + attrlen, 0, RTA_ALIGN(size) - size);
444 }
445 
446 size_t rtattr_strlcpy(char *dest, const struct rtattr *rta, size_t size)
447 {
448 	size_t ret = RTA_PAYLOAD(rta);
449 	char *src = RTA_DATA(rta);
450 
451 	if (ret > 0 && src[ret - 1] == '\0')
452 		ret--;
453 	if (size > 0) {
454 		size_t len = (ret >= size) ? size - 1 : ret;
455 		memset(dest, 0, size);
456 		memcpy(dest, src, len);
457 	}
458 	return ret;
459 }
460 
461 int rtnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo)
462 {
463 	int err = 0;
464 
465 	NETLINK_CB(skb).dst_group = group;
466 	if (echo)
467 		atomic_inc(&skb->users);
468 	netlink_broadcast(rtnl, skb, pid, group, GFP_KERNEL);
469 	if (echo)
470 		err = netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
471 	return err;
472 }
473 
474 int rtnl_unicast(struct sk_buff *skb, u32 pid)
475 {
476 	return nlmsg_unicast(rtnl, skb, pid);
477 }
478 
479 int rtnl_notify(struct sk_buff *skb, u32 pid, u32 group,
480 		struct nlmsghdr *nlh, gfp_t flags)
481 {
482 	int report = 0;
483 
484 	if (nlh)
485 		report = nlmsg_report(nlh);
486 
487 	return nlmsg_notify(rtnl, skb, pid, group, report, flags);
488 }
489 
490 void rtnl_set_sk_err(u32 group, int error)
491 {
492 	netlink_set_err(rtnl, 0, group, error);
493 }
494 
495 int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics)
496 {
497 	struct nlattr *mx;
498 	int i, valid = 0;
499 
500 	mx = nla_nest_start(skb, RTA_METRICS);
501 	if (mx == NULL)
502 		return -ENOBUFS;
503 
504 	for (i = 0; i < RTAX_MAX; i++) {
505 		if (metrics[i]) {
506 			valid++;
507 			NLA_PUT_U32(skb, i+1, metrics[i]);
508 		}
509 	}
510 
511 	if (!valid) {
512 		nla_nest_cancel(skb, mx);
513 		return 0;
514 	}
515 
516 	return nla_nest_end(skb, mx);
517 
518 nla_put_failure:
519 	return nla_nest_cancel(skb, mx);
520 }
521 
522 int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id,
523 		       u32 ts, u32 tsage, long expires, u32 error)
524 {
525 	struct rta_cacheinfo ci = {
526 		.rta_lastuse = jiffies_to_clock_t(jiffies - dst->lastuse),
527 		.rta_used = dst->__use,
528 		.rta_clntref = atomic_read(&(dst->__refcnt)),
529 		.rta_error = error,
530 		.rta_id =  id,
531 		.rta_ts = ts,
532 		.rta_tsage = tsage,
533 	};
534 
535 	if (expires)
536 		ci.rta_expires = jiffies_to_clock_t(expires);
537 
538 	return nla_put(skb, RTA_CACHEINFO, sizeof(ci), &ci);
539 }
540 
541 EXPORT_SYMBOL_GPL(rtnl_put_cacheinfo);
542 
543 static void set_operstate(struct net_device *dev, unsigned char transition)
544 {
545 	unsigned char operstate = dev->operstate;
546 
547 	switch(transition) {
548 	case IF_OPER_UP:
549 		if ((operstate == IF_OPER_DORMANT ||
550 		     operstate == IF_OPER_UNKNOWN) &&
551 		    !netif_dormant(dev))
552 			operstate = IF_OPER_UP;
553 		break;
554 
555 	case IF_OPER_DORMANT:
556 		if (operstate == IF_OPER_UP ||
557 		    operstate == IF_OPER_UNKNOWN)
558 			operstate = IF_OPER_DORMANT;
559 		break;
560 	}
561 
562 	if (dev->operstate != operstate) {
563 		write_lock_bh(&dev_base_lock);
564 		dev->operstate = operstate;
565 		write_unlock_bh(&dev_base_lock);
566 		netdev_state_change(dev);
567 	}
568 }
569 
570 static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
571 				 struct net_device_stats *b)
572 {
573 	a->rx_packets = b->rx_packets;
574 	a->tx_packets = b->tx_packets;
575 	a->rx_bytes = b->rx_bytes;
576 	a->tx_bytes = b->tx_bytes;
577 	a->rx_errors = b->rx_errors;
578 	a->tx_errors = b->tx_errors;
579 	a->rx_dropped = b->rx_dropped;
580 	a->tx_dropped = b->tx_dropped;
581 
582 	a->multicast = b->multicast;
583 	a->collisions = b->collisions;
584 
585 	a->rx_length_errors = b->rx_length_errors;
586 	a->rx_over_errors = b->rx_over_errors;
587 	a->rx_crc_errors = b->rx_crc_errors;
588 	a->rx_frame_errors = b->rx_frame_errors;
589 	a->rx_fifo_errors = b->rx_fifo_errors;
590 	a->rx_missed_errors = b->rx_missed_errors;
591 
592 	a->tx_aborted_errors = b->tx_aborted_errors;
593 	a->tx_carrier_errors = b->tx_carrier_errors;
594 	a->tx_fifo_errors = b->tx_fifo_errors;
595 	a->tx_heartbeat_errors = b->tx_heartbeat_errors;
596 	a->tx_window_errors = b->tx_window_errors;
597 
598 	a->rx_compressed = b->rx_compressed;
599 	a->tx_compressed = b->tx_compressed;
600 };
601 
602 static inline size_t if_nlmsg_size(const struct net_device *dev)
603 {
604 	return NLMSG_ALIGN(sizeof(struct ifinfomsg))
605 	       + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
606 	       + nla_total_size(IFNAMSIZ) /* IFLA_QDISC */
607 	       + nla_total_size(sizeof(struct rtnl_link_ifmap))
608 	       + nla_total_size(sizeof(struct rtnl_link_stats))
609 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
610 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_BROADCAST */
611 	       + nla_total_size(4) /* IFLA_TXQLEN */
612 	       + nla_total_size(4) /* IFLA_WEIGHT */
613 	       + nla_total_size(4) /* IFLA_MTU */
614 	       + nla_total_size(4) /* IFLA_LINK */
615 	       + nla_total_size(4) /* IFLA_MASTER */
616 	       + nla_total_size(1) /* IFLA_OPERSTATE */
617 	       + nla_total_size(1) /* IFLA_LINKMODE */
618 	       + rtnl_link_get_size(dev); /* IFLA_LINKINFO */
619 }
620 
621 static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
622 			    int type, u32 pid, u32 seq, u32 change,
623 			    unsigned int flags)
624 {
625 	struct ifinfomsg *ifm;
626 	struct nlmsghdr *nlh;
627 
628 	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ifm), flags);
629 	if (nlh == NULL)
630 		return -EMSGSIZE;
631 
632 	ifm = nlmsg_data(nlh);
633 	ifm->ifi_family = AF_UNSPEC;
634 	ifm->__ifi_pad = 0;
635 	ifm->ifi_type = dev->type;
636 	ifm->ifi_index = dev->ifindex;
637 	ifm->ifi_flags = dev_get_flags(dev);
638 	ifm->ifi_change = change;
639 
640 	NLA_PUT_STRING(skb, IFLA_IFNAME, dev->name);
641 	NLA_PUT_U32(skb, IFLA_TXQLEN, dev->tx_queue_len);
642 	NLA_PUT_U8(skb, IFLA_OPERSTATE,
643 		   netif_running(dev) ? dev->operstate : IF_OPER_DOWN);
644 	NLA_PUT_U8(skb, IFLA_LINKMODE, dev->link_mode);
645 	NLA_PUT_U32(skb, IFLA_MTU, dev->mtu);
646 
647 	if (dev->ifindex != dev->iflink)
648 		NLA_PUT_U32(skb, IFLA_LINK, dev->iflink);
649 
650 	if (dev->master)
651 		NLA_PUT_U32(skb, IFLA_MASTER, dev->master->ifindex);
652 
653 	if (dev->qdisc_sleeping)
654 		NLA_PUT_STRING(skb, IFLA_QDISC, dev->qdisc_sleeping->ops->id);
655 
656 	if (1) {
657 		struct rtnl_link_ifmap map = {
658 			.mem_start   = dev->mem_start,
659 			.mem_end     = dev->mem_end,
660 			.base_addr   = dev->base_addr,
661 			.irq         = dev->irq,
662 			.dma         = dev->dma,
663 			.port        = dev->if_port,
664 		};
665 		NLA_PUT(skb, IFLA_MAP, sizeof(map), &map);
666 	}
667 
668 	if (dev->addr_len) {
669 		NLA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr);
670 		NLA_PUT(skb, IFLA_BROADCAST, dev->addr_len, dev->broadcast);
671 	}
672 
673 	if (dev->get_stats) {
674 		struct net_device_stats *stats = dev->get_stats(dev);
675 		if (stats) {
676 			struct nlattr *attr;
677 
678 			attr = nla_reserve(skb, IFLA_STATS,
679 					   sizeof(struct rtnl_link_stats));
680 			if (attr == NULL)
681 				goto nla_put_failure;
682 
683 			copy_rtnl_link_stats(nla_data(attr), stats);
684 		}
685 	}
686 
687 	if (dev->rtnl_link_ops) {
688 		if (rtnl_link_fill(skb, dev) < 0)
689 			goto nla_put_failure;
690 	}
691 
692 	return nlmsg_end(skb, nlh);
693 
694 nla_put_failure:
695 	nlmsg_cancel(skb, nlh);
696 	return -EMSGSIZE;
697 }
698 
699 static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
700 {
701 	struct net *net = skb->sk->sk_net;
702 	int idx;
703 	int s_idx = cb->args[0];
704 	struct net_device *dev;
705 
706 	idx = 0;
707 	for_each_netdev(net, dev) {
708 		if (idx < s_idx)
709 			goto cont;
710 		if (rtnl_fill_ifinfo(skb, dev, RTM_NEWLINK,
711 				     NETLINK_CB(cb->skb).pid,
712 				     cb->nlh->nlmsg_seq, 0, NLM_F_MULTI) <= 0)
713 			break;
714 cont:
715 		idx++;
716 	}
717 	cb->args[0] = idx;
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_TXQLEN]		= { .type = NLA_U32 },
729 	[IFLA_WEIGHT]		= { .type = NLA_U32 },
730 	[IFLA_OPERSTATE]	= { .type = NLA_U8 },
731 	[IFLA_LINKMODE]		= { .type = NLA_U8 },
732 	[IFLA_NET_NS_PID]	= { .type = NLA_U32 },
733 };
734 
735 static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
736 	[IFLA_INFO_KIND]	= { .type = NLA_STRING },
737 	[IFLA_INFO_DATA]	= { .type = NLA_NESTED },
738 };
739 
740 static struct net *get_net_ns_by_pid(pid_t pid)
741 {
742 	struct task_struct *tsk;
743 	struct net *net;
744 
745 	/* Lookup the network namespace */
746 	net = ERR_PTR(-ESRCH);
747 	rcu_read_lock();
748 	tsk = find_task_by_vpid(pid);
749 	if (tsk) {
750 		struct nsproxy *nsproxy;
751 		nsproxy = task_nsproxy(tsk);
752 		if (nsproxy)
753 			net = get_net(nsproxy->net_ns);
754 	}
755 	rcu_read_unlock();
756 	return net;
757 }
758 
759 static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
760 		      struct nlattr **tb, char *ifname, int modified)
761 {
762 	int send_addr_notify = 0;
763 	int err;
764 
765 	if (tb[IFLA_NET_NS_PID]) {
766 		struct net *net;
767 		net = get_net_ns_by_pid(nla_get_u32(tb[IFLA_NET_NS_PID]));
768 		if (IS_ERR(net)) {
769 			err = PTR_ERR(net);
770 			goto errout;
771 		}
772 		err = dev_change_net_namespace(dev, net, ifname);
773 		put_net(net);
774 		if (err)
775 			goto errout;
776 		modified = 1;
777 	}
778 
779 	if (tb[IFLA_MAP]) {
780 		struct rtnl_link_ifmap *u_map;
781 		struct ifmap k_map;
782 
783 		if (!dev->set_config) {
784 			err = -EOPNOTSUPP;
785 			goto errout;
786 		}
787 
788 		if (!netif_device_present(dev)) {
789 			err = -ENODEV;
790 			goto errout;
791 		}
792 
793 		u_map = nla_data(tb[IFLA_MAP]);
794 		k_map.mem_start = (unsigned long) u_map->mem_start;
795 		k_map.mem_end = (unsigned long) u_map->mem_end;
796 		k_map.base_addr = (unsigned short) u_map->base_addr;
797 		k_map.irq = (unsigned char) u_map->irq;
798 		k_map.dma = (unsigned char) u_map->dma;
799 		k_map.port = (unsigned char) u_map->port;
800 
801 		err = dev->set_config(dev, &k_map);
802 		if (err < 0)
803 			goto errout;
804 
805 		modified = 1;
806 	}
807 
808 	if (tb[IFLA_ADDRESS]) {
809 		struct sockaddr *sa;
810 		int len;
811 
812 		if (!dev->set_mac_address) {
813 			err = -EOPNOTSUPP;
814 			goto errout;
815 		}
816 
817 		if (!netif_device_present(dev)) {
818 			err = -ENODEV;
819 			goto errout;
820 		}
821 
822 		len = sizeof(sa_family_t) + dev->addr_len;
823 		sa = kmalloc(len, GFP_KERNEL);
824 		if (!sa) {
825 			err = -ENOMEM;
826 			goto errout;
827 		}
828 		sa->sa_family = dev->type;
829 		memcpy(sa->sa_data, nla_data(tb[IFLA_ADDRESS]),
830 		       dev->addr_len);
831 		err = dev->set_mac_address(dev, sa);
832 		kfree(sa);
833 		if (err)
834 			goto errout;
835 		send_addr_notify = 1;
836 		modified = 1;
837 	}
838 
839 	if (tb[IFLA_MTU]) {
840 		err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
841 		if (err < 0)
842 			goto errout;
843 		modified = 1;
844 	}
845 
846 	/*
847 	 * Interface selected by interface index but interface
848 	 * name provided implies that a name change has been
849 	 * requested.
850 	 */
851 	if (ifm->ifi_index > 0 && ifname[0]) {
852 		err = dev_change_name(dev, ifname);
853 		if (err < 0)
854 			goto errout;
855 		modified = 1;
856 	}
857 
858 	if (tb[IFLA_BROADCAST]) {
859 		nla_memcpy(dev->broadcast, tb[IFLA_BROADCAST], dev->addr_len);
860 		send_addr_notify = 1;
861 	}
862 
863 	if (ifm->ifi_flags || ifm->ifi_change) {
864 		unsigned int flags = ifm->ifi_flags;
865 
866 		/* bugwards compatibility: ifi_change == 0 is treated as ~0 */
867 		if (ifm->ifi_change)
868 			flags = (flags & ifm->ifi_change) |
869 				(dev->flags & ~ifm->ifi_change);
870 		dev_change_flags(dev, flags);
871 	}
872 
873 	if (tb[IFLA_TXQLEN])
874 		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
875 
876 	if (tb[IFLA_OPERSTATE])
877 		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
878 
879 	if (tb[IFLA_LINKMODE]) {
880 		write_lock_bh(&dev_base_lock);
881 		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
882 		write_unlock_bh(&dev_base_lock);
883 	}
884 
885 	err = 0;
886 
887 errout:
888 	if (err < 0 && modified && net_ratelimit())
889 		printk(KERN_WARNING "A link change request failed with "
890 		       "some changes comitted already. Interface %s may "
891 		       "have been left with an inconsistent configuration, "
892 		       "please check.\n", dev->name);
893 
894 	if (send_addr_notify)
895 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
896 	return err;
897 }
898 
899 static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
900 {
901 	struct net *net = skb->sk->sk_net;
902 	struct ifinfomsg *ifm;
903 	struct net_device *dev;
904 	int err;
905 	struct nlattr *tb[IFLA_MAX+1];
906 	char ifname[IFNAMSIZ];
907 
908 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
909 	if (err < 0)
910 		goto errout;
911 
912 	if (tb[IFLA_IFNAME])
913 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
914 	else
915 		ifname[0] = '\0';
916 
917 	err = -EINVAL;
918 	ifm = nlmsg_data(nlh);
919 	if (ifm->ifi_index > 0)
920 		dev = dev_get_by_index(net, ifm->ifi_index);
921 	else if (tb[IFLA_IFNAME])
922 		dev = dev_get_by_name(net, ifname);
923 	else
924 		goto errout;
925 
926 	if (dev == NULL) {
927 		err = -ENODEV;
928 		goto errout;
929 	}
930 
931 	if (tb[IFLA_ADDRESS] &&
932 	    nla_len(tb[IFLA_ADDRESS]) < dev->addr_len)
933 		goto errout_dev;
934 
935 	if (tb[IFLA_BROADCAST] &&
936 	    nla_len(tb[IFLA_BROADCAST]) < dev->addr_len)
937 		goto errout_dev;
938 
939 	err = do_setlink(dev, ifm, tb, ifname, 0);
940 errout_dev:
941 	dev_put(dev);
942 errout:
943 	return err;
944 }
945 
946 static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
947 {
948 	struct net *net = skb->sk->sk_net;
949 	const struct rtnl_link_ops *ops;
950 	struct net_device *dev;
951 	struct ifinfomsg *ifm;
952 	char ifname[IFNAMSIZ];
953 	struct nlattr *tb[IFLA_MAX+1];
954 	int err;
955 
956 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
957 	if (err < 0)
958 		return err;
959 
960 	if (tb[IFLA_IFNAME])
961 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
962 
963 	ifm = nlmsg_data(nlh);
964 	if (ifm->ifi_index > 0)
965 		dev = __dev_get_by_index(net, ifm->ifi_index);
966 	else if (tb[IFLA_IFNAME])
967 		dev = __dev_get_by_name(net, ifname);
968 	else
969 		return -EINVAL;
970 
971 	if (!dev)
972 		return -ENODEV;
973 
974 	ops = dev->rtnl_link_ops;
975 	if (!ops)
976 		return -EOPNOTSUPP;
977 
978 	ops->dellink(dev);
979 	return 0;
980 }
981 
982 struct net_device *rtnl_create_link(struct net *net, char *ifname,
983 		const struct rtnl_link_ops *ops, struct nlattr *tb[])
984 {
985 	int err;
986 	struct net_device *dev;
987 
988 	err = -ENOMEM;
989 	dev = alloc_netdev(ops->priv_size, ifname, ops->setup);
990 	if (!dev)
991 		goto err;
992 
993 	if (strchr(dev->name, '%')) {
994 		err = dev_alloc_name(dev, dev->name);
995 		if (err < 0)
996 			goto err_free;
997 	}
998 
999 	dev->nd_net = net;
1000 	dev->rtnl_link_ops = ops;
1001 
1002 	if (tb[IFLA_MTU])
1003 		dev->mtu = nla_get_u32(tb[IFLA_MTU]);
1004 	if (tb[IFLA_ADDRESS])
1005 		memcpy(dev->dev_addr, nla_data(tb[IFLA_ADDRESS]),
1006 				nla_len(tb[IFLA_ADDRESS]));
1007 	if (tb[IFLA_BROADCAST])
1008 		memcpy(dev->broadcast, nla_data(tb[IFLA_BROADCAST]),
1009 				nla_len(tb[IFLA_BROADCAST]));
1010 	if (tb[IFLA_TXQLEN])
1011 		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
1012 	if (tb[IFLA_OPERSTATE])
1013 		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
1014 	if (tb[IFLA_LINKMODE])
1015 		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
1016 
1017 	return dev;
1018 
1019 err_free:
1020 	free_netdev(dev);
1021 err:
1022 	return ERR_PTR(err);
1023 }
1024 
1025 static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
1026 {
1027 	struct net *net = skb->sk->sk_net;
1028 	const struct rtnl_link_ops *ops;
1029 	struct net_device *dev;
1030 	struct ifinfomsg *ifm;
1031 	char kind[MODULE_NAME_LEN];
1032 	char ifname[IFNAMSIZ];
1033 	struct nlattr *tb[IFLA_MAX+1];
1034 	struct nlattr *linkinfo[IFLA_INFO_MAX+1];
1035 	int err;
1036 
1037 #ifdef CONFIG_KMOD
1038 replay:
1039 #endif
1040 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
1041 	if (err < 0)
1042 		return err;
1043 
1044 	if (tb[IFLA_IFNAME])
1045 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
1046 	else
1047 		ifname[0] = '\0';
1048 
1049 	ifm = nlmsg_data(nlh);
1050 	if (ifm->ifi_index > 0)
1051 		dev = __dev_get_by_index(net, ifm->ifi_index);
1052 	else if (ifname[0])
1053 		dev = __dev_get_by_name(net, ifname);
1054 	else
1055 		dev = NULL;
1056 
1057 	if (tb[IFLA_LINKINFO]) {
1058 		err = nla_parse_nested(linkinfo, IFLA_INFO_MAX,
1059 				       tb[IFLA_LINKINFO], ifla_info_policy);
1060 		if (err < 0)
1061 			return err;
1062 	} else
1063 		memset(linkinfo, 0, sizeof(linkinfo));
1064 
1065 	if (linkinfo[IFLA_INFO_KIND]) {
1066 		nla_strlcpy(kind, linkinfo[IFLA_INFO_KIND], sizeof(kind));
1067 		ops = rtnl_link_ops_get(kind);
1068 	} else {
1069 		kind[0] = '\0';
1070 		ops = NULL;
1071 	}
1072 
1073 	if (1) {
1074 		struct nlattr *attr[ops ? ops->maxtype + 1 : 0], **data = NULL;
1075 
1076 		if (ops) {
1077 			if (ops->maxtype && linkinfo[IFLA_INFO_DATA]) {
1078 				err = nla_parse_nested(attr, ops->maxtype,
1079 						       linkinfo[IFLA_INFO_DATA],
1080 						       ops->policy);
1081 				if (err < 0)
1082 					return err;
1083 				data = attr;
1084 			}
1085 			if (ops->validate) {
1086 				err = ops->validate(tb, data);
1087 				if (err < 0)
1088 					return err;
1089 			}
1090 		}
1091 
1092 		if (dev) {
1093 			int modified = 0;
1094 
1095 			if (nlh->nlmsg_flags & NLM_F_EXCL)
1096 				return -EEXIST;
1097 			if (nlh->nlmsg_flags & NLM_F_REPLACE)
1098 				return -EOPNOTSUPP;
1099 
1100 			if (linkinfo[IFLA_INFO_DATA]) {
1101 				if (!ops || ops != dev->rtnl_link_ops ||
1102 				    !ops->changelink)
1103 					return -EOPNOTSUPP;
1104 
1105 				err = ops->changelink(dev, tb, data);
1106 				if (err < 0)
1107 					return err;
1108 				modified = 1;
1109 			}
1110 
1111 			return do_setlink(dev, ifm, tb, ifname, modified);
1112 		}
1113 
1114 		if (!(nlh->nlmsg_flags & NLM_F_CREATE))
1115 			return -ENODEV;
1116 
1117 		if (ifm->ifi_index || ifm->ifi_flags || ifm->ifi_change)
1118 			return -EOPNOTSUPP;
1119 		if (tb[IFLA_MAP] || tb[IFLA_MASTER] || tb[IFLA_PROTINFO])
1120 			return -EOPNOTSUPP;
1121 
1122 		if (!ops) {
1123 #ifdef CONFIG_KMOD
1124 			if (kind[0]) {
1125 				__rtnl_unlock();
1126 				request_module("rtnl-link-%s", kind);
1127 				rtnl_lock();
1128 				ops = rtnl_link_ops_get(kind);
1129 				if (ops)
1130 					goto replay;
1131 			}
1132 #endif
1133 			return -EOPNOTSUPP;
1134 		}
1135 
1136 		if (!ifname[0])
1137 			snprintf(ifname, IFNAMSIZ, "%s%%d", ops->kind);
1138 
1139 		dev = rtnl_create_link(net, ifname, ops, tb);
1140 
1141 		if (IS_ERR(dev))
1142 			err = PTR_ERR(dev);
1143 		else if (ops->newlink)
1144 			err = ops->newlink(dev, tb, data);
1145 		else
1146 			err = register_netdevice(dev);
1147 
1148 		if (err < 0 && !IS_ERR(dev))
1149 			free_netdev(dev);
1150 		return err;
1151 	}
1152 }
1153 
1154 static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
1155 {
1156 	struct net *net = skb->sk->sk_net;
1157 	struct ifinfomsg *ifm;
1158 	struct nlattr *tb[IFLA_MAX+1];
1159 	struct net_device *dev = NULL;
1160 	struct sk_buff *nskb;
1161 	int err;
1162 
1163 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
1164 	if (err < 0)
1165 		return err;
1166 
1167 	ifm = nlmsg_data(nlh);
1168 	if (ifm->ifi_index > 0) {
1169 		dev = dev_get_by_index(net, ifm->ifi_index);
1170 		if (dev == NULL)
1171 			return -ENODEV;
1172 	} else
1173 		return -EINVAL;
1174 
1175 	nskb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
1176 	if (nskb == NULL) {
1177 		err = -ENOBUFS;
1178 		goto errout;
1179 	}
1180 
1181 	err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).pid,
1182 			       nlh->nlmsg_seq, 0, 0);
1183 	if (err < 0) {
1184 		/* -EMSGSIZE implies BUG in if_nlmsg_size */
1185 		WARN_ON(err == -EMSGSIZE);
1186 		kfree_skb(nskb);
1187 		goto errout;
1188 	}
1189 	err = rtnl_unicast(nskb, NETLINK_CB(skb).pid);
1190 errout:
1191 	dev_put(dev);
1192 
1193 	return err;
1194 }
1195 
1196 static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
1197 {
1198 	int idx;
1199 	int s_idx = cb->family;
1200 
1201 	if (s_idx == 0)
1202 		s_idx = 1;
1203 	for (idx=1; idx<NPROTO; idx++) {
1204 		int type = cb->nlh->nlmsg_type-RTM_BASE;
1205 		if (idx < s_idx || idx == PF_PACKET)
1206 			continue;
1207 		if (rtnl_msg_handlers[idx] == NULL ||
1208 		    rtnl_msg_handlers[idx][type].dumpit == NULL)
1209 			continue;
1210 		if (idx > s_idx)
1211 			memset(&cb->args[0], 0, sizeof(cb->args));
1212 		if (rtnl_msg_handlers[idx][type].dumpit(skb, cb))
1213 			break;
1214 	}
1215 	cb->family = idx;
1216 
1217 	return skb->len;
1218 }
1219 
1220 void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change)
1221 {
1222 	struct sk_buff *skb;
1223 	int err = -ENOBUFS;
1224 
1225 	skb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
1226 	if (skb == NULL)
1227 		goto errout;
1228 
1229 	err = rtnl_fill_ifinfo(skb, dev, type, 0, 0, change, 0);
1230 	if (err < 0) {
1231 		/* -EMSGSIZE implies BUG in if_nlmsg_size() */
1232 		WARN_ON(err == -EMSGSIZE);
1233 		kfree_skb(skb);
1234 		goto errout;
1235 	}
1236 	err = rtnl_notify(skb, 0, RTNLGRP_LINK, NULL, GFP_KERNEL);
1237 errout:
1238 	if (err < 0)
1239 		rtnl_set_sk_err(RTNLGRP_LINK, err);
1240 }
1241 
1242 /* Protected by RTNL sempahore.  */
1243 static struct rtattr **rta_buf;
1244 static int rtattr_max;
1245 
1246 /* Process one rtnetlink message. */
1247 
1248 static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
1249 {
1250 	rtnl_doit_func doit;
1251 	int sz_idx, kind;
1252 	int min_len;
1253 	int family;
1254 	int type;
1255 	int err;
1256 
1257 	type = nlh->nlmsg_type;
1258 	if (type > RTM_MAX)
1259 		return -EOPNOTSUPP;
1260 
1261 	type -= RTM_BASE;
1262 
1263 	/* All the messages must have at least 1 byte length */
1264 	if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct rtgenmsg)))
1265 		return 0;
1266 
1267 	family = ((struct rtgenmsg*)NLMSG_DATA(nlh))->rtgen_family;
1268 	if (family >= NPROTO)
1269 		return -EAFNOSUPPORT;
1270 
1271 	sz_idx = type>>2;
1272 	kind = type&3;
1273 
1274 	if (kind != 2 && security_netlink_recv(skb, CAP_NET_ADMIN))
1275 		return -EPERM;
1276 
1277 	if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
1278 		rtnl_dumpit_func dumpit;
1279 
1280 		dumpit = rtnl_get_dumpit(family, type);
1281 		if (dumpit == NULL)
1282 			return -EOPNOTSUPP;
1283 
1284 		__rtnl_unlock();
1285 		err = netlink_dump_start(rtnl, skb, nlh, dumpit, NULL);
1286 		rtnl_lock();
1287 		return err;
1288 	}
1289 
1290 	memset(rta_buf, 0, (rtattr_max * sizeof(struct rtattr *)));
1291 
1292 	min_len = rtm_min[sz_idx];
1293 	if (nlh->nlmsg_len < min_len)
1294 		return -EINVAL;
1295 
1296 	if (nlh->nlmsg_len > min_len) {
1297 		int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
1298 		struct rtattr *attr = (void*)nlh + NLMSG_ALIGN(min_len);
1299 
1300 		while (RTA_OK(attr, attrlen)) {
1301 			unsigned flavor = attr->rta_type;
1302 			if (flavor) {
1303 				if (flavor > rta_max[sz_idx])
1304 					return -EINVAL;
1305 				rta_buf[flavor-1] = attr;
1306 			}
1307 			attr = RTA_NEXT(attr, attrlen);
1308 		}
1309 	}
1310 
1311 	doit = rtnl_get_doit(family, type);
1312 	if (doit == NULL)
1313 		return -EOPNOTSUPP;
1314 
1315 	return doit(skb, nlh, (void *)&rta_buf[0]);
1316 }
1317 
1318 static void rtnetlink_rcv(struct sk_buff *skb)
1319 {
1320 	rtnl_lock();
1321 	netlink_rcv_skb(skb, &rtnetlink_rcv_msg);
1322 	rtnl_unlock();
1323 }
1324 
1325 static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr)
1326 {
1327 	struct net_device *dev = ptr;
1328 
1329 	if (dev->nd_net != &init_net)
1330 		return NOTIFY_DONE;
1331 
1332 	switch (event) {
1333 	case NETDEV_UNREGISTER:
1334 		rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
1335 		break;
1336 	case NETDEV_REGISTER:
1337 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
1338 		break;
1339 	case NETDEV_UP:
1340 	case NETDEV_DOWN:
1341 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1342 		break;
1343 	case NETDEV_CHANGE:
1344 	case NETDEV_GOING_DOWN:
1345 		break;
1346 	default:
1347 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
1348 		break;
1349 	}
1350 	return NOTIFY_DONE;
1351 }
1352 
1353 static struct notifier_block rtnetlink_dev_notifier = {
1354 	.notifier_call	= rtnetlink_event,
1355 };
1356 
1357 void __init rtnetlink_init(void)
1358 {
1359 	int i;
1360 
1361 	rtattr_max = 0;
1362 	for (i = 0; i < ARRAY_SIZE(rta_max); i++)
1363 		if (rta_max[i] > rtattr_max)
1364 			rtattr_max = rta_max[i];
1365 	rta_buf = kmalloc(rtattr_max * sizeof(struct rtattr *), GFP_KERNEL);
1366 	if (!rta_buf)
1367 		panic("rtnetlink_init: cannot allocate rta_buf\n");
1368 
1369 	rtnl = netlink_kernel_create(&init_net, NETLINK_ROUTE, RTNLGRP_MAX,
1370 				     rtnetlink_rcv, &rtnl_mutex, THIS_MODULE);
1371 	if (rtnl == NULL)
1372 		panic("rtnetlink_init: cannot initialize rtnetlink\n");
1373 	netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
1374 	register_netdevice_notifier(&rtnetlink_dev_notifier);
1375 
1376 	rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink, rtnl_dump_ifinfo);
1377 	rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL);
1378 	rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL);
1379 	rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL);
1380 
1381 	rtnl_register(PF_UNSPEC, RTM_GETADDR, NULL, rtnl_dump_all);
1382 	rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all);
1383 }
1384 
1385 EXPORT_SYMBOL(__rta_fill);
1386 EXPORT_SYMBOL(rtattr_strlcpy);
1387 EXPORT_SYMBOL(rtattr_parse);
1388 EXPORT_SYMBOL(__rtattr_parse_nested_compat);
1389 EXPORT_SYMBOL(rtnetlink_put_metrics);
1390 EXPORT_SYMBOL(rtnl_lock);
1391 EXPORT_SYMBOL(rtnl_trylock);
1392 EXPORT_SYMBOL(rtnl_unlock);
1393 EXPORT_SYMBOL(rtnl_unicast);
1394 EXPORT_SYMBOL(rtnl_notify);
1395 EXPORT_SYMBOL(rtnl_set_sk_err);
1396 EXPORT_SYMBOL(rtnl_create_link);
1397 EXPORT_SYMBOL(ifla_policy);
1398