xref: /linux/net/core/rtnetlink.c (revision 7b04fa014c11e6415da8b5a7999dbd201abad53c)
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 int rtnl_is_locked(void)
86 {
87 	return mutex_is_locked(&rtnl_mutex);
88 }
89 
90 static struct rtnl_link *rtnl_msg_handlers[NPROTO];
91 
92 static inline int rtm_msgindex(int msgtype)
93 {
94 	int msgindex = msgtype - RTM_BASE;
95 
96 	/*
97 	 * msgindex < 0 implies someone tried to register a netlink
98 	 * control code. msgindex >= RTM_NR_MSGTYPES may indicate that
99 	 * the message type has not been added to linux/rtnetlink.h
100 	 */
101 	BUG_ON(msgindex < 0 || msgindex >= RTM_NR_MSGTYPES);
102 
103 	return msgindex;
104 }
105 
106 static rtnl_doit_func rtnl_get_doit(int protocol, int msgindex)
107 {
108 	struct rtnl_link *tab;
109 
110 	tab = rtnl_msg_handlers[protocol];
111 	if (tab == NULL || tab[msgindex].doit == NULL)
112 		tab = rtnl_msg_handlers[PF_UNSPEC];
113 
114 	return tab ? tab[msgindex].doit : NULL;
115 }
116 
117 static rtnl_dumpit_func rtnl_get_dumpit(int protocol, int msgindex)
118 {
119 	struct rtnl_link *tab;
120 
121 	tab = rtnl_msg_handlers[protocol];
122 	if (tab == NULL || tab[msgindex].dumpit == NULL)
123 		tab = rtnl_msg_handlers[PF_UNSPEC];
124 
125 	return tab ? tab[msgindex].dumpit : NULL;
126 }
127 
128 /**
129  * __rtnl_register - Register a rtnetlink message type
130  * @protocol: Protocol family or PF_UNSPEC
131  * @msgtype: rtnetlink message type
132  * @doit: Function pointer called for each request message
133  * @dumpit: Function pointer called for each dump request (NLM_F_DUMP) message
134  *
135  * Registers the specified function pointers (at least one of them has
136  * to be non-NULL) to be called whenever a request message for the
137  * specified protocol family and message type is received.
138  *
139  * The special protocol family PF_UNSPEC may be used to define fallback
140  * function pointers for the case when no entry for the specific protocol
141  * family exists.
142  *
143  * Returns 0 on success or a negative error code.
144  */
145 int __rtnl_register(int protocol, int msgtype,
146 		    rtnl_doit_func doit, rtnl_dumpit_func dumpit)
147 {
148 	struct rtnl_link *tab;
149 	int msgindex;
150 
151 	BUG_ON(protocol < 0 || protocol >= NPROTO);
152 	msgindex = rtm_msgindex(msgtype);
153 
154 	tab = rtnl_msg_handlers[protocol];
155 	if (tab == NULL) {
156 		tab = kcalloc(RTM_NR_MSGTYPES, sizeof(*tab), GFP_KERNEL);
157 		if (tab == NULL)
158 			return -ENOBUFS;
159 
160 		rtnl_msg_handlers[protocol] = tab;
161 	}
162 
163 	if (doit)
164 		tab[msgindex].doit = doit;
165 
166 	if (dumpit)
167 		tab[msgindex].dumpit = dumpit;
168 
169 	return 0;
170 }
171 
172 EXPORT_SYMBOL_GPL(__rtnl_register);
173 
174 /**
175  * rtnl_register - Register a rtnetlink message type
176  *
177  * Identical to __rtnl_register() but panics on failure. This is useful
178  * as failure of this function is very unlikely, it can only happen due
179  * to lack of memory when allocating the chain to store all message
180  * handlers for a protocol. Meant for use in init functions where lack
181  * of memory implies no sense in continueing.
182  */
183 void rtnl_register(int protocol, int msgtype,
184 		   rtnl_doit_func doit, rtnl_dumpit_func dumpit)
185 {
186 	if (__rtnl_register(protocol, msgtype, doit, dumpit) < 0)
187 		panic("Unable to register rtnetlink message handler, "
188 		      "protocol = %d, message type = %d\n",
189 		      protocol, msgtype);
190 }
191 
192 EXPORT_SYMBOL_GPL(rtnl_register);
193 
194 /**
195  * rtnl_unregister - Unregister a rtnetlink message type
196  * @protocol: Protocol family or PF_UNSPEC
197  * @msgtype: rtnetlink message type
198  *
199  * Returns 0 on success or a negative error code.
200  */
201 int rtnl_unregister(int protocol, int msgtype)
202 {
203 	int msgindex;
204 
205 	BUG_ON(protocol < 0 || protocol >= NPROTO);
206 	msgindex = rtm_msgindex(msgtype);
207 
208 	if (rtnl_msg_handlers[protocol] == NULL)
209 		return -ENOENT;
210 
211 	rtnl_msg_handlers[protocol][msgindex].doit = NULL;
212 	rtnl_msg_handlers[protocol][msgindex].dumpit = NULL;
213 
214 	return 0;
215 }
216 
217 EXPORT_SYMBOL_GPL(rtnl_unregister);
218 
219 /**
220  * rtnl_unregister_all - Unregister all rtnetlink message type of a protocol
221  * @protocol : Protocol family or PF_UNSPEC
222  *
223  * Identical to calling rtnl_unregster() for all registered message types
224  * of a certain protocol family.
225  */
226 void rtnl_unregister_all(int protocol)
227 {
228 	BUG_ON(protocol < 0 || protocol >= NPROTO);
229 
230 	kfree(rtnl_msg_handlers[protocol]);
231 	rtnl_msg_handlers[protocol] = NULL;
232 }
233 
234 EXPORT_SYMBOL_GPL(rtnl_unregister_all);
235 
236 static LIST_HEAD(link_ops);
237 
238 /**
239  * __rtnl_link_register - Register rtnl_link_ops with rtnetlink.
240  * @ops: struct rtnl_link_ops * to register
241  *
242  * The caller must hold the rtnl_mutex. This function should be used
243  * by drivers that create devices during module initialization. It
244  * must be called before registering the devices.
245  *
246  * Returns 0 on success or a negative error code.
247  */
248 int __rtnl_link_register(struct rtnl_link_ops *ops)
249 {
250 	if (!ops->dellink)
251 		ops->dellink = unregister_netdevice;
252 
253 	list_add_tail(&ops->list, &link_ops);
254 	return 0;
255 }
256 
257 EXPORT_SYMBOL_GPL(__rtnl_link_register);
258 
259 /**
260  * rtnl_link_register - Register rtnl_link_ops with rtnetlink.
261  * @ops: struct rtnl_link_ops * to register
262  *
263  * Returns 0 on success or a negative error code.
264  */
265 int rtnl_link_register(struct rtnl_link_ops *ops)
266 {
267 	int err;
268 
269 	rtnl_lock();
270 	err = __rtnl_link_register(ops);
271 	rtnl_unlock();
272 	return err;
273 }
274 
275 EXPORT_SYMBOL_GPL(rtnl_link_register);
276 
277 static void __rtnl_kill_links(struct net *net, struct rtnl_link_ops *ops)
278 {
279 	struct net_device *dev;
280 restart:
281 	for_each_netdev(net, dev) {
282 		if (dev->rtnl_link_ops == ops) {
283 			ops->dellink(dev);
284 			goto restart;
285 		}
286 	}
287 }
288 
289 void rtnl_kill_links(struct net *net, struct rtnl_link_ops *ops)
290 {
291 	rtnl_lock();
292 	__rtnl_kill_links(net, ops);
293 	rtnl_unlock();
294 }
295 EXPORT_SYMBOL_GPL(rtnl_kill_links);
296 
297 /**
298  * __rtnl_link_unregister - Unregister rtnl_link_ops from rtnetlink.
299  * @ops: struct rtnl_link_ops * to unregister
300  *
301  * The caller must hold the rtnl_mutex.
302  */
303 void __rtnl_link_unregister(struct rtnl_link_ops *ops)
304 {
305 	struct net *net;
306 
307 	for_each_net(net) {
308 		__rtnl_kill_links(net, ops);
309 	}
310 	list_del(&ops->list);
311 }
312 
313 EXPORT_SYMBOL_GPL(__rtnl_link_unregister);
314 
315 /**
316  * rtnl_link_unregister - Unregister rtnl_link_ops from rtnetlink.
317  * @ops: struct rtnl_link_ops * to unregister
318  */
319 void rtnl_link_unregister(struct rtnl_link_ops *ops)
320 {
321 	rtnl_lock();
322 	__rtnl_link_unregister(ops);
323 	rtnl_unlock();
324 }
325 
326 EXPORT_SYMBOL_GPL(rtnl_link_unregister);
327 
328 static const struct rtnl_link_ops *rtnl_link_ops_get(const char *kind)
329 {
330 	const struct rtnl_link_ops *ops;
331 
332 	list_for_each_entry(ops, &link_ops, list) {
333 		if (!strcmp(ops->kind, kind))
334 			return ops;
335 	}
336 	return NULL;
337 }
338 
339 static size_t rtnl_link_get_size(const struct net_device *dev)
340 {
341 	const struct rtnl_link_ops *ops = dev->rtnl_link_ops;
342 	size_t size;
343 
344 	if (!ops)
345 		return 0;
346 
347 	size = nlmsg_total_size(sizeof(struct nlattr)) + /* IFLA_LINKINFO */
348 	       nlmsg_total_size(strlen(ops->kind) + 1);	 /* IFLA_INFO_KIND */
349 
350 	if (ops->get_size)
351 		/* IFLA_INFO_DATA + nested data */
352 		size += nlmsg_total_size(sizeof(struct nlattr)) +
353 			ops->get_size(dev);
354 
355 	if (ops->get_xstats_size)
356 		size += ops->get_xstats_size(dev);	/* IFLA_INFO_XSTATS */
357 
358 	return size;
359 }
360 
361 static int rtnl_link_fill(struct sk_buff *skb, const struct net_device *dev)
362 {
363 	const struct rtnl_link_ops *ops = dev->rtnl_link_ops;
364 	struct nlattr *linkinfo, *data;
365 	int err = -EMSGSIZE;
366 
367 	linkinfo = nla_nest_start(skb, IFLA_LINKINFO);
368 	if (linkinfo == NULL)
369 		goto out;
370 
371 	if (nla_put_string(skb, IFLA_INFO_KIND, ops->kind) < 0)
372 		goto err_cancel_link;
373 	if (ops->fill_xstats) {
374 		err = ops->fill_xstats(skb, dev);
375 		if (err < 0)
376 			goto err_cancel_link;
377 	}
378 	if (ops->fill_info) {
379 		data = nla_nest_start(skb, IFLA_INFO_DATA);
380 		if (data == NULL)
381 			goto err_cancel_link;
382 		err = ops->fill_info(skb, dev);
383 		if (err < 0)
384 			goto err_cancel_data;
385 		nla_nest_end(skb, data);
386 	}
387 
388 	nla_nest_end(skb, linkinfo);
389 	return 0;
390 
391 err_cancel_data:
392 	nla_nest_cancel(skb, data);
393 err_cancel_link:
394 	nla_nest_cancel(skb, linkinfo);
395 out:
396 	return err;
397 }
398 
399 static const int rtm_min[RTM_NR_FAMILIES] =
400 {
401 	[RTM_FAM(RTM_NEWLINK)]      = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
402 	[RTM_FAM(RTM_NEWADDR)]      = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
403 	[RTM_FAM(RTM_NEWROUTE)]     = NLMSG_LENGTH(sizeof(struct rtmsg)),
404 	[RTM_FAM(RTM_NEWRULE)]      = NLMSG_LENGTH(sizeof(struct fib_rule_hdr)),
405 	[RTM_FAM(RTM_NEWQDISC)]     = NLMSG_LENGTH(sizeof(struct tcmsg)),
406 	[RTM_FAM(RTM_NEWTCLASS)]    = NLMSG_LENGTH(sizeof(struct tcmsg)),
407 	[RTM_FAM(RTM_NEWTFILTER)]   = NLMSG_LENGTH(sizeof(struct tcmsg)),
408 	[RTM_FAM(RTM_NEWACTION)]    = NLMSG_LENGTH(sizeof(struct tcamsg)),
409 	[RTM_FAM(RTM_GETMULTICAST)] = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
410 	[RTM_FAM(RTM_GETANYCAST)]   = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
411 };
412 
413 static const int rta_max[RTM_NR_FAMILIES] =
414 {
415 	[RTM_FAM(RTM_NEWLINK)]      = IFLA_MAX,
416 	[RTM_FAM(RTM_NEWADDR)]      = IFA_MAX,
417 	[RTM_FAM(RTM_NEWROUTE)]     = RTA_MAX,
418 	[RTM_FAM(RTM_NEWRULE)]      = FRA_MAX,
419 	[RTM_FAM(RTM_NEWQDISC)]     = TCA_MAX,
420 	[RTM_FAM(RTM_NEWTCLASS)]    = TCA_MAX,
421 	[RTM_FAM(RTM_NEWTFILTER)]   = TCA_MAX,
422 	[RTM_FAM(RTM_NEWACTION)]    = TCAA_MAX,
423 };
424 
425 void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
426 {
427 	struct rtattr *rta;
428 	int size = RTA_LENGTH(attrlen);
429 
430 	rta = (struct rtattr*)skb_put(skb, RTA_ALIGN(size));
431 	rta->rta_type = attrtype;
432 	rta->rta_len = size;
433 	memcpy(RTA_DATA(rta), data, attrlen);
434 	memset(RTA_DATA(rta) + attrlen, 0, RTA_ALIGN(size) - size);
435 }
436 
437 int rtnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, unsigned group, int echo)
438 {
439 	struct sock *rtnl = net->rtnl;
440 	int err = 0;
441 
442 	NETLINK_CB(skb).dst_group = group;
443 	if (echo)
444 		atomic_inc(&skb->users);
445 	netlink_broadcast(rtnl, skb, pid, group, GFP_KERNEL);
446 	if (echo)
447 		err = netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
448 	return err;
449 }
450 
451 int rtnl_unicast(struct sk_buff *skb, struct net *net, u32 pid)
452 {
453 	struct sock *rtnl = net->rtnl;
454 
455 	return nlmsg_unicast(rtnl, skb, pid);
456 }
457 
458 int rtnl_notify(struct sk_buff *skb, struct net *net, u32 pid, u32 group,
459 		struct nlmsghdr *nlh, gfp_t flags)
460 {
461 	struct sock *rtnl = net->rtnl;
462 	int report = 0;
463 
464 	if (nlh)
465 		report = nlmsg_report(nlh);
466 
467 	return nlmsg_notify(rtnl, skb, pid, group, report, flags);
468 }
469 
470 void rtnl_set_sk_err(struct net *net, u32 group, int error)
471 {
472 	struct sock *rtnl = net->rtnl;
473 
474 	netlink_set_err(rtnl, 0, group, error);
475 }
476 
477 int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics)
478 {
479 	struct nlattr *mx;
480 	int i, valid = 0;
481 
482 	mx = nla_nest_start(skb, RTA_METRICS);
483 	if (mx == NULL)
484 		return -ENOBUFS;
485 
486 	for (i = 0; i < RTAX_MAX; i++) {
487 		if (metrics[i]) {
488 			valid++;
489 			NLA_PUT_U32(skb, i+1, metrics[i]);
490 		}
491 	}
492 
493 	if (!valid) {
494 		nla_nest_cancel(skb, mx);
495 		return 0;
496 	}
497 
498 	return nla_nest_end(skb, mx);
499 
500 nla_put_failure:
501 	return nla_nest_cancel(skb, mx);
502 }
503 
504 int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id,
505 		       u32 ts, u32 tsage, long expires, u32 error)
506 {
507 	struct rta_cacheinfo ci = {
508 		.rta_lastuse = jiffies_to_clock_t(jiffies - dst->lastuse),
509 		.rta_used = dst->__use,
510 		.rta_clntref = atomic_read(&(dst->__refcnt)),
511 		.rta_error = error,
512 		.rta_id =  id,
513 		.rta_ts = ts,
514 		.rta_tsage = tsage,
515 	};
516 
517 	if (expires)
518 		ci.rta_expires = jiffies_to_clock_t(expires);
519 
520 	return nla_put(skb, RTA_CACHEINFO, sizeof(ci), &ci);
521 }
522 
523 EXPORT_SYMBOL_GPL(rtnl_put_cacheinfo);
524 
525 static void set_operstate(struct net_device *dev, unsigned char transition)
526 {
527 	unsigned char operstate = dev->operstate;
528 
529 	switch(transition) {
530 	case IF_OPER_UP:
531 		if ((operstate == IF_OPER_DORMANT ||
532 		     operstate == IF_OPER_UNKNOWN) &&
533 		    !netif_dormant(dev))
534 			operstate = IF_OPER_UP;
535 		break;
536 
537 	case IF_OPER_DORMANT:
538 		if (operstate == IF_OPER_UP ||
539 		    operstate == IF_OPER_UNKNOWN)
540 			operstate = IF_OPER_DORMANT;
541 		break;
542 	}
543 
544 	if (dev->operstate != operstate) {
545 		write_lock_bh(&dev_base_lock);
546 		dev->operstate = operstate;
547 		write_unlock_bh(&dev_base_lock);
548 		netdev_state_change(dev);
549 	}
550 }
551 
552 static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
553 				 struct net_device_stats *b)
554 {
555 	a->rx_packets = b->rx_packets;
556 	a->tx_packets = b->tx_packets;
557 	a->rx_bytes = b->rx_bytes;
558 	a->tx_bytes = b->tx_bytes;
559 	a->rx_errors = b->rx_errors;
560 	a->tx_errors = b->tx_errors;
561 	a->rx_dropped = b->rx_dropped;
562 	a->tx_dropped = b->tx_dropped;
563 
564 	a->multicast = b->multicast;
565 	a->collisions = b->collisions;
566 
567 	a->rx_length_errors = b->rx_length_errors;
568 	a->rx_over_errors = b->rx_over_errors;
569 	a->rx_crc_errors = b->rx_crc_errors;
570 	a->rx_frame_errors = b->rx_frame_errors;
571 	a->rx_fifo_errors = b->rx_fifo_errors;
572 	a->rx_missed_errors = b->rx_missed_errors;
573 
574 	a->tx_aborted_errors = b->tx_aborted_errors;
575 	a->tx_carrier_errors = b->tx_carrier_errors;
576 	a->tx_fifo_errors = b->tx_fifo_errors;
577 	a->tx_heartbeat_errors = b->tx_heartbeat_errors;
578 	a->tx_window_errors = b->tx_window_errors;
579 
580 	a->rx_compressed = b->rx_compressed;
581 	a->tx_compressed = b->tx_compressed;
582 };
583 
584 static inline size_t if_nlmsg_size(const struct net_device *dev)
585 {
586 	return NLMSG_ALIGN(sizeof(struct ifinfomsg))
587 	       + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
588 	       + nla_total_size(IFNAMSIZ) /* IFLA_QDISC */
589 	       + nla_total_size(sizeof(struct rtnl_link_ifmap))
590 	       + nla_total_size(sizeof(struct rtnl_link_stats))
591 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
592 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_BROADCAST */
593 	       + nla_total_size(4) /* IFLA_TXQLEN */
594 	       + nla_total_size(4) /* IFLA_WEIGHT */
595 	       + nla_total_size(4) /* IFLA_MTU */
596 	       + nla_total_size(4) /* IFLA_LINK */
597 	       + nla_total_size(4) /* IFLA_MASTER */
598 	       + nla_total_size(1) /* IFLA_OPERSTATE */
599 	       + nla_total_size(1) /* IFLA_LINKMODE */
600 	       + rtnl_link_get_size(dev); /* IFLA_LINKINFO */
601 }
602 
603 static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
604 			    int type, u32 pid, u32 seq, u32 change,
605 			    unsigned int flags)
606 {
607 	struct ifinfomsg *ifm;
608 	struct nlmsghdr *nlh;
609 
610 	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ifm), flags);
611 	if (nlh == NULL)
612 		return -EMSGSIZE;
613 
614 	ifm = nlmsg_data(nlh);
615 	ifm->ifi_family = AF_UNSPEC;
616 	ifm->__ifi_pad = 0;
617 	ifm->ifi_type = dev->type;
618 	ifm->ifi_index = dev->ifindex;
619 	ifm->ifi_flags = dev_get_flags(dev);
620 	ifm->ifi_change = change;
621 
622 	NLA_PUT_STRING(skb, IFLA_IFNAME, dev->name);
623 	NLA_PUT_U32(skb, IFLA_TXQLEN, dev->tx_queue_len);
624 	NLA_PUT_U8(skb, IFLA_OPERSTATE,
625 		   netif_running(dev) ? dev->operstate : IF_OPER_DOWN);
626 	NLA_PUT_U8(skb, IFLA_LINKMODE, dev->link_mode);
627 	NLA_PUT_U32(skb, IFLA_MTU, dev->mtu);
628 
629 	if (dev->ifindex != dev->iflink)
630 		NLA_PUT_U32(skb, IFLA_LINK, dev->iflink);
631 
632 	if (dev->master)
633 		NLA_PUT_U32(skb, IFLA_MASTER, dev->master->ifindex);
634 
635 	if (dev->qdisc_sleeping)
636 		NLA_PUT_STRING(skb, IFLA_QDISC, dev->qdisc_sleeping->ops->id);
637 
638 	if (1) {
639 		struct rtnl_link_ifmap map = {
640 			.mem_start   = dev->mem_start,
641 			.mem_end     = dev->mem_end,
642 			.base_addr   = dev->base_addr,
643 			.irq         = dev->irq,
644 			.dma         = dev->dma,
645 			.port        = dev->if_port,
646 		};
647 		NLA_PUT(skb, IFLA_MAP, sizeof(map), &map);
648 	}
649 
650 	if (dev->addr_len) {
651 		NLA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr);
652 		NLA_PUT(skb, IFLA_BROADCAST, dev->addr_len, dev->broadcast);
653 	}
654 
655 	if (dev->get_stats) {
656 		struct net_device_stats *stats = dev->get_stats(dev);
657 		if (stats) {
658 			struct nlattr *attr;
659 
660 			attr = nla_reserve(skb, IFLA_STATS,
661 					   sizeof(struct rtnl_link_stats));
662 			if (attr == NULL)
663 				goto nla_put_failure;
664 
665 			copy_rtnl_link_stats(nla_data(attr), stats);
666 		}
667 	}
668 
669 	if (dev->rtnl_link_ops) {
670 		if (rtnl_link_fill(skb, dev) < 0)
671 			goto nla_put_failure;
672 	}
673 
674 	return nlmsg_end(skb, nlh);
675 
676 nla_put_failure:
677 	nlmsg_cancel(skb, nlh);
678 	return -EMSGSIZE;
679 }
680 
681 static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
682 {
683 	struct net *net = sock_net(skb->sk);
684 	int idx;
685 	int s_idx = cb->args[0];
686 	struct net_device *dev;
687 
688 	idx = 0;
689 	for_each_netdev(net, dev) {
690 		if (idx < s_idx)
691 			goto cont;
692 		if (rtnl_fill_ifinfo(skb, dev, RTM_NEWLINK,
693 				     NETLINK_CB(cb->skb).pid,
694 				     cb->nlh->nlmsg_seq, 0, NLM_F_MULTI) <= 0)
695 			break;
696 cont:
697 		idx++;
698 	}
699 	cb->args[0] = idx;
700 
701 	return skb->len;
702 }
703 
704 const struct nla_policy ifla_policy[IFLA_MAX+1] = {
705 	[IFLA_IFNAME]		= { .type = NLA_STRING, .len = IFNAMSIZ-1 },
706 	[IFLA_ADDRESS]		= { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
707 	[IFLA_BROADCAST]	= { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
708 	[IFLA_MAP]		= { .len = sizeof(struct rtnl_link_ifmap) },
709 	[IFLA_MTU]		= { .type = NLA_U32 },
710 	[IFLA_LINK]		= { .type = NLA_U32 },
711 	[IFLA_TXQLEN]		= { .type = NLA_U32 },
712 	[IFLA_WEIGHT]		= { .type = NLA_U32 },
713 	[IFLA_OPERSTATE]	= { .type = NLA_U8 },
714 	[IFLA_LINKMODE]		= { .type = NLA_U8 },
715 	[IFLA_LINKINFO]		= { .type = NLA_NESTED },
716 	[IFLA_NET_NS_PID]	= { .type = NLA_U32 },
717 };
718 
719 static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
720 	[IFLA_INFO_KIND]	= { .type = NLA_STRING },
721 	[IFLA_INFO_DATA]	= { .type = NLA_NESTED },
722 };
723 
724 static struct net *get_net_ns_by_pid(pid_t pid)
725 {
726 	struct task_struct *tsk;
727 	struct net *net;
728 
729 	/* Lookup the network namespace */
730 	net = ERR_PTR(-ESRCH);
731 	rcu_read_lock();
732 	tsk = find_task_by_vpid(pid);
733 	if (tsk) {
734 		struct nsproxy *nsproxy;
735 		nsproxy = task_nsproxy(tsk);
736 		if (nsproxy)
737 			net = get_net(nsproxy->net_ns);
738 	}
739 	rcu_read_unlock();
740 	return net;
741 }
742 
743 static int validate_linkmsg(struct net_device *dev, struct nlattr *tb[])
744 {
745 	if (dev) {
746 		if (tb[IFLA_ADDRESS] &&
747 		    nla_len(tb[IFLA_ADDRESS]) < dev->addr_len)
748 			return -EINVAL;
749 
750 		if (tb[IFLA_BROADCAST] &&
751 		    nla_len(tb[IFLA_BROADCAST]) < dev->addr_len)
752 			return -EINVAL;
753 	}
754 
755 	return 0;
756 }
757 
758 static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
759 		      struct nlattr **tb, char *ifname, int modified)
760 {
761 	int send_addr_notify = 0;
762 	int err;
763 
764 	if (tb[IFLA_NET_NS_PID]) {
765 		struct net *net;
766 		net = get_net_ns_by_pid(nla_get_u32(tb[IFLA_NET_NS_PID]));
767 		if (IS_ERR(net)) {
768 			err = PTR_ERR(net);
769 			goto errout;
770 		}
771 		err = dev_change_net_namespace(dev, net, ifname);
772 		put_net(net);
773 		if (err)
774 			goto errout;
775 		modified = 1;
776 	}
777 
778 	if (tb[IFLA_MAP]) {
779 		struct rtnl_link_ifmap *u_map;
780 		struct ifmap k_map;
781 
782 		if (!dev->set_config) {
783 			err = -EOPNOTSUPP;
784 			goto errout;
785 		}
786 
787 		if (!netif_device_present(dev)) {
788 			err = -ENODEV;
789 			goto errout;
790 		}
791 
792 		u_map = nla_data(tb[IFLA_MAP]);
793 		k_map.mem_start = (unsigned long) u_map->mem_start;
794 		k_map.mem_end = (unsigned long) u_map->mem_end;
795 		k_map.base_addr = (unsigned short) u_map->base_addr;
796 		k_map.irq = (unsigned char) u_map->irq;
797 		k_map.dma = (unsigned char) u_map->dma;
798 		k_map.port = (unsigned char) u_map->port;
799 
800 		err = dev->set_config(dev, &k_map);
801 		if (err < 0)
802 			goto errout;
803 
804 		modified = 1;
805 	}
806 
807 	if (tb[IFLA_ADDRESS]) {
808 		struct sockaddr *sa;
809 		int len;
810 
811 		if (!dev->set_mac_address) {
812 			err = -EOPNOTSUPP;
813 			goto errout;
814 		}
815 
816 		if (!netif_device_present(dev)) {
817 			err = -ENODEV;
818 			goto errout;
819 		}
820 
821 		len = sizeof(sa_family_t) + dev->addr_len;
822 		sa = kmalloc(len, GFP_KERNEL);
823 		if (!sa) {
824 			err = -ENOMEM;
825 			goto errout;
826 		}
827 		sa->sa_family = dev->type;
828 		memcpy(sa->sa_data, nla_data(tb[IFLA_ADDRESS]),
829 		       dev->addr_len);
830 		err = dev->set_mac_address(dev, sa);
831 		kfree(sa);
832 		if (err)
833 			goto errout;
834 		send_addr_notify = 1;
835 		modified = 1;
836 	}
837 
838 	if (tb[IFLA_MTU]) {
839 		err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
840 		if (err < 0)
841 			goto errout;
842 		modified = 1;
843 	}
844 
845 	/*
846 	 * Interface selected by interface index but interface
847 	 * name provided implies that a name change has been
848 	 * requested.
849 	 */
850 	if (ifm->ifi_index > 0 && ifname[0]) {
851 		err = dev_change_name(dev, ifname);
852 		if (err < 0)
853 			goto errout;
854 		modified = 1;
855 	}
856 
857 	if (tb[IFLA_BROADCAST]) {
858 		nla_memcpy(dev->broadcast, tb[IFLA_BROADCAST], dev->addr_len);
859 		send_addr_notify = 1;
860 	}
861 
862 	if (ifm->ifi_flags || ifm->ifi_change) {
863 		unsigned int flags = ifm->ifi_flags;
864 
865 		/* bugwards compatibility: ifi_change == 0 is treated as ~0 */
866 		if (ifm->ifi_change)
867 			flags = (flags & ifm->ifi_change) |
868 				(dev->flags & ~ifm->ifi_change);
869 		dev_change_flags(dev, flags);
870 	}
871 
872 	if (tb[IFLA_TXQLEN])
873 		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
874 
875 	if (tb[IFLA_OPERSTATE])
876 		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
877 
878 	if (tb[IFLA_LINKMODE]) {
879 		write_lock_bh(&dev_base_lock);
880 		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
881 		write_unlock_bh(&dev_base_lock);
882 	}
883 
884 	err = 0;
885 
886 errout:
887 	if (err < 0 && modified && net_ratelimit())
888 		printk(KERN_WARNING "A link change request failed with "
889 		       "some changes comitted already. Interface %s may "
890 		       "have been left with an inconsistent configuration, "
891 		       "please check.\n", dev->name);
892 
893 	if (send_addr_notify)
894 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
895 	return err;
896 }
897 
898 static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
899 {
900 	struct net *net = sock_net(skb->sk);
901 	struct ifinfomsg *ifm;
902 	struct net_device *dev;
903 	int err;
904 	struct nlattr *tb[IFLA_MAX+1];
905 	char ifname[IFNAMSIZ];
906 
907 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
908 	if (err < 0)
909 		goto errout;
910 
911 	if (tb[IFLA_IFNAME])
912 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
913 	else
914 		ifname[0] = '\0';
915 
916 	err = -EINVAL;
917 	ifm = nlmsg_data(nlh);
918 	if (ifm->ifi_index > 0)
919 		dev = dev_get_by_index(net, ifm->ifi_index);
920 	else if (tb[IFLA_IFNAME])
921 		dev = dev_get_by_name(net, ifname);
922 	else
923 		goto errout;
924 
925 	if (dev == NULL) {
926 		err = -ENODEV;
927 		goto errout;
928 	}
929 
930 	if ((err = validate_linkmsg(dev, tb)) < 0)
931 		goto errout_dev;
932 
933 	err = do_setlink(dev, ifm, tb, ifname, 0);
934 errout_dev:
935 	dev_put(dev);
936 errout:
937 	return err;
938 }
939 
940 static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
941 {
942 	struct net *net = sock_net(skb->sk);
943 	const struct rtnl_link_ops *ops;
944 	struct net_device *dev;
945 	struct ifinfomsg *ifm;
946 	char ifname[IFNAMSIZ];
947 	struct nlattr *tb[IFLA_MAX+1];
948 	int err;
949 
950 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
951 	if (err < 0)
952 		return err;
953 
954 	if (tb[IFLA_IFNAME])
955 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
956 
957 	ifm = nlmsg_data(nlh);
958 	if (ifm->ifi_index > 0)
959 		dev = __dev_get_by_index(net, ifm->ifi_index);
960 	else if (tb[IFLA_IFNAME])
961 		dev = __dev_get_by_name(net, ifname);
962 	else
963 		return -EINVAL;
964 
965 	if (!dev)
966 		return -ENODEV;
967 
968 	ops = dev->rtnl_link_ops;
969 	if (!ops)
970 		return -EOPNOTSUPP;
971 
972 	ops->dellink(dev);
973 	return 0;
974 }
975 
976 struct net_device *rtnl_create_link(struct net *net, char *ifname,
977 		const struct rtnl_link_ops *ops, struct nlattr *tb[])
978 {
979 	int err;
980 	struct net_device *dev;
981 
982 	err = -ENOMEM;
983 	dev = alloc_netdev(ops->priv_size, ifname, ops->setup);
984 	if (!dev)
985 		goto err;
986 
987 	if (strchr(dev->name, '%')) {
988 		err = dev_alloc_name(dev, dev->name);
989 		if (err < 0)
990 			goto err_free;
991 	}
992 
993 	dev_net_set(dev, net);
994 	dev->rtnl_link_ops = ops;
995 
996 	if (tb[IFLA_MTU])
997 		dev->mtu = nla_get_u32(tb[IFLA_MTU]);
998 	if (tb[IFLA_ADDRESS])
999 		memcpy(dev->dev_addr, nla_data(tb[IFLA_ADDRESS]),
1000 				nla_len(tb[IFLA_ADDRESS]));
1001 	if (tb[IFLA_BROADCAST])
1002 		memcpy(dev->broadcast, nla_data(tb[IFLA_BROADCAST]),
1003 				nla_len(tb[IFLA_BROADCAST]));
1004 	if (tb[IFLA_TXQLEN])
1005 		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
1006 	if (tb[IFLA_OPERSTATE])
1007 		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
1008 	if (tb[IFLA_LINKMODE])
1009 		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
1010 
1011 	return dev;
1012 
1013 err_free:
1014 	free_netdev(dev);
1015 err:
1016 	return ERR_PTR(err);
1017 }
1018 
1019 static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
1020 {
1021 	struct net *net = sock_net(skb->sk);
1022 	const struct rtnl_link_ops *ops;
1023 	struct net_device *dev;
1024 	struct ifinfomsg *ifm;
1025 	char kind[MODULE_NAME_LEN];
1026 	char ifname[IFNAMSIZ];
1027 	struct nlattr *tb[IFLA_MAX+1];
1028 	struct nlattr *linkinfo[IFLA_INFO_MAX+1];
1029 	int err;
1030 
1031 #ifdef CONFIG_KMOD
1032 replay:
1033 #endif
1034 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
1035 	if (err < 0)
1036 		return err;
1037 
1038 	if (tb[IFLA_IFNAME])
1039 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
1040 	else
1041 		ifname[0] = '\0';
1042 
1043 	ifm = nlmsg_data(nlh);
1044 	if (ifm->ifi_index > 0)
1045 		dev = __dev_get_by_index(net, ifm->ifi_index);
1046 	else if (ifname[0])
1047 		dev = __dev_get_by_name(net, ifname);
1048 	else
1049 		dev = NULL;
1050 
1051 	if ((err = validate_linkmsg(dev, tb)) < 0)
1052 		return err;
1053 
1054 	if (tb[IFLA_LINKINFO]) {
1055 		err = nla_parse_nested(linkinfo, IFLA_INFO_MAX,
1056 				       tb[IFLA_LINKINFO], ifla_info_policy);
1057 		if (err < 0)
1058 			return err;
1059 	} else
1060 		memset(linkinfo, 0, sizeof(linkinfo));
1061 
1062 	if (linkinfo[IFLA_INFO_KIND]) {
1063 		nla_strlcpy(kind, linkinfo[IFLA_INFO_KIND], sizeof(kind));
1064 		ops = rtnl_link_ops_get(kind);
1065 	} else {
1066 		kind[0] = '\0';
1067 		ops = NULL;
1068 	}
1069 
1070 	if (1) {
1071 		struct nlattr *attr[ops ? ops->maxtype + 1 : 0], **data = NULL;
1072 
1073 		if (ops) {
1074 			if (ops->maxtype && linkinfo[IFLA_INFO_DATA]) {
1075 				err = nla_parse_nested(attr, ops->maxtype,
1076 						       linkinfo[IFLA_INFO_DATA],
1077 						       ops->policy);
1078 				if (err < 0)
1079 					return err;
1080 				data = attr;
1081 			}
1082 			if (ops->validate) {
1083 				err = ops->validate(tb, data);
1084 				if (err < 0)
1085 					return err;
1086 			}
1087 		}
1088 
1089 		if (dev) {
1090 			int modified = 0;
1091 
1092 			if (nlh->nlmsg_flags & NLM_F_EXCL)
1093 				return -EEXIST;
1094 			if (nlh->nlmsg_flags & NLM_F_REPLACE)
1095 				return -EOPNOTSUPP;
1096 
1097 			if (linkinfo[IFLA_INFO_DATA]) {
1098 				if (!ops || ops != dev->rtnl_link_ops ||
1099 				    !ops->changelink)
1100 					return -EOPNOTSUPP;
1101 
1102 				err = ops->changelink(dev, tb, data);
1103 				if (err < 0)
1104 					return err;
1105 				modified = 1;
1106 			}
1107 
1108 			return do_setlink(dev, ifm, tb, ifname, modified);
1109 		}
1110 
1111 		if (!(nlh->nlmsg_flags & NLM_F_CREATE))
1112 			return -ENODEV;
1113 
1114 		if (ifm->ifi_index || ifm->ifi_flags || ifm->ifi_change)
1115 			return -EOPNOTSUPP;
1116 		if (tb[IFLA_MAP] || tb[IFLA_MASTER] || tb[IFLA_PROTINFO])
1117 			return -EOPNOTSUPP;
1118 
1119 		if (!ops) {
1120 #ifdef CONFIG_KMOD
1121 			if (kind[0]) {
1122 				__rtnl_unlock();
1123 				request_module("rtnl-link-%s", kind);
1124 				rtnl_lock();
1125 				ops = rtnl_link_ops_get(kind);
1126 				if (ops)
1127 					goto replay;
1128 			}
1129 #endif
1130 			return -EOPNOTSUPP;
1131 		}
1132 
1133 		if (!ifname[0])
1134 			snprintf(ifname, IFNAMSIZ, "%s%%d", ops->kind);
1135 
1136 		dev = rtnl_create_link(net, ifname, ops, tb);
1137 
1138 		if (IS_ERR(dev))
1139 			err = PTR_ERR(dev);
1140 		else if (ops->newlink)
1141 			err = ops->newlink(dev, tb, data);
1142 		else
1143 			err = register_netdevice(dev);
1144 
1145 		if (err < 0 && !IS_ERR(dev))
1146 			free_netdev(dev);
1147 		return err;
1148 	}
1149 }
1150 
1151 static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
1152 {
1153 	struct net *net = sock_net(skb->sk);
1154 	struct ifinfomsg *ifm;
1155 	struct nlattr *tb[IFLA_MAX+1];
1156 	struct net_device *dev = NULL;
1157 	struct sk_buff *nskb;
1158 	int err;
1159 
1160 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
1161 	if (err < 0)
1162 		return err;
1163 
1164 	ifm = nlmsg_data(nlh);
1165 	if (ifm->ifi_index > 0) {
1166 		dev = dev_get_by_index(net, ifm->ifi_index);
1167 		if (dev == NULL)
1168 			return -ENODEV;
1169 	} else
1170 		return -EINVAL;
1171 
1172 	nskb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
1173 	if (nskb == NULL) {
1174 		err = -ENOBUFS;
1175 		goto errout;
1176 	}
1177 
1178 	err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).pid,
1179 			       nlh->nlmsg_seq, 0, 0);
1180 	if (err < 0) {
1181 		/* -EMSGSIZE implies BUG in if_nlmsg_size */
1182 		WARN_ON(err == -EMSGSIZE);
1183 		kfree_skb(nskb);
1184 		goto errout;
1185 	}
1186 	err = rtnl_unicast(nskb, net, NETLINK_CB(skb).pid);
1187 errout:
1188 	dev_put(dev);
1189 
1190 	return err;
1191 }
1192 
1193 static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
1194 {
1195 	int idx;
1196 	int s_idx = cb->family;
1197 
1198 	if (s_idx == 0)
1199 		s_idx = 1;
1200 	for (idx=1; idx<NPROTO; idx++) {
1201 		int type = cb->nlh->nlmsg_type-RTM_BASE;
1202 		if (idx < s_idx || idx == PF_PACKET)
1203 			continue;
1204 		if (rtnl_msg_handlers[idx] == NULL ||
1205 		    rtnl_msg_handlers[idx][type].dumpit == NULL)
1206 			continue;
1207 		if (idx > s_idx)
1208 			memset(&cb->args[0], 0, sizeof(cb->args));
1209 		if (rtnl_msg_handlers[idx][type].dumpit(skb, cb))
1210 			break;
1211 	}
1212 	cb->family = idx;
1213 
1214 	return skb->len;
1215 }
1216 
1217 void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change)
1218 {
1219 	struct net *net = dev_net(dev);
1220 	struct sk_buff *skb;
1221 	int err = -ENOBUFS;
1222 
1223 	skb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
1224 	if (skb == NULL)
1225 		goto errout;
1226 
1227 	err = rtnl_fill_ifinfo(skb, dev, type, 0, 0, change, 0);
1228 	if (err < 0) {
1229 		/* -EMSGSIZE implies BUG in if_nlmsg_size() */
1230 		WARN_ON(err == -EMSGSIZE);
1231 		kfree_skb(skb);
1232 		goto errout;
1233 	}
1234 	err = rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_KERNEL);
1235 errout:
1236 	if (err < 0)
1237 		rtnl_set_sk_err(net, RTNLGRP_LINK, err);
1238 }
1239 
1240 /* Protected by RTNL sempahore.  */
1241 static struct rtattr **rta_buf;
1242 static int rtattr_max;
1243 
1244 /* Process one rtnetlink message. */
1245 
1246 static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
1247 {
1248 	struct net *net = sock_net(skb->sk);
1249 	rtnl_doit_func doit;
1250 	int sz_idx, kind;
1251 	int min_len;
1252 	int family;
1253 	int type;
1254 	int err;
1255 
1256 	type = nlh->nlmsg_type;
1257 	if (type > RTM_MAX)
1258 		return -EOPNOTSUPP;
1259 
1260 	type -= RTM_BASE;
1261 
1262 	/* All the messages must have at least 1 byte length */
1263 	if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct rtgenmsg)))
1264 		return 0;
1265 
1266 	family = ((struct rtgenmsg*)NLMSG_DATA(nlh))->rtgen_family;
1267 	if (family >= NPROTO)
1268 		return -EAFNOSUPPORT;
1269 
1270 	sz_idx = type>>2;
1271 	kind = type&3;
1272 
1273 	if (kind != 2 && security_netlink_recv(skb, CAP_NET_ADMIN))
1274 		return -EPERM;
1275 
1276 	if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
1277 		struct sock *rtnl;
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 		rtnl = net->rtnl;
1286 		err = netlink_dump_start(rtnl, skb, nlh, dumpit, NULL);
1287 		rtnl_lock();
1288 		return err;
1289 	}
1290 
1291 	memset(rta_buf, 0, (rtattr_max * sizeof(struct rtattr *)));
1292 
1293 	min_len = rtm_min[sz_idx];
1294 	if (nlh->nlmsg_len < min_len)
1295 		return -EINVAL;
1296 
1297 	if (nlh->nlmsg_len > min_len) {
1298 		int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
1299 		struct rtattr *attr = (void*)nlh + NLMSG_ALIGN(min_len);
1300 
1301 		while (RTA_OK(attr, attrlen)) {
1302 			unsigned flavor = attr->rta_type;
1303 			if (flavor) {
1304 				if (flavor > rta_max[sz_idx])
1305 					return -EINVAL;
1306 				rta_buf[flavor-1] = attr;
1307 			}
1308 			attr = RTA_NEXT(attr, attrlen);
1309 		}
1310 	}
1311 
1312 	doit = rtnl_get_doit(family, type);
1313 	if (doit == NULL)
1314 		return -EOPNOTSUPP;
1315 
1316 	return doit(skb, nlh, (void *)&rta_buf[0]);
1317 }
1318 
1319 static void rtnetlink_rcv(struct sk_buff *skb)
1320 {
1321 	rtnl_lock();
1322 	netlink_rcv_skb(skb, &rtnetlink_rcv_msg);
1323 	rtnl_unlock();
1324 }
1325 
1326 static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr)
1327 {
1328 	struct net_device *dev = ptr;
1329 
1330 	switch (event) {
1331 	case NETDEV_UNREGISTER:
1332 		rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
1333 		break;
1334 	case NETDEV_REGISTER:
1335 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
1336 		break;
1337 	case NETDEV_UP:
1338 	case NETDEV_DOWN:
1339 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1340 		break;
1341 	case NETDEV_CHANGE:
1342 	case NETDEV_GOING_DOWN:
1343 		break;
1344 	default:
1345 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
1346 		break;
1347 	}
1348 	return NOTIFY_DONE;
1349 }
1350 
1351 static struct notifier_block rtnetlink_dev_notifier = {
1352 	.notifier_call	= rtnetlink_event,
1353 };
1354 
1355 
1356 static int rtnetlink_net_init(struct net *net)
1357 {
1358 	struct sock *sk;
1359 	sk = netlink_kernel_create(net, NETLINK_ROUTE, RTNLGRP_MAX,
1360 				   rtnetlink_rcv, &rtnl_mutex, THIS_MODULE);
1361 	if (!sk)
1362 		return -ENOMEM;
1363 	net->rtnl = sk;
1364 	return 0;
1365 }
1366 
1367 static void rtnetlink_net_exit(struct net *net)
1368 {
1369 	netlink_kernel_release(net->rtnl);
1370 	net->rtnl = NULL;
1371 }
1372 
1373 static struct pernet_operations rtnetlink_net_ops = {
1374 	.init = rtnetlink_net_init,
1375 	.exit = rtnetlink_net_exit,
1376 };
1377 
1378 void __init rtnetlink_init(void)
1379 {
1380 	int i;
1381 
1382 	rtattr_max = 0;
1383 	for (i = 0; i < ARRAY_SIZE(rta_max); i++)
1384 		if (rta_max[i] > rtattr_max)
1385 			rtattr_max = rta_max[i];
1386 	rta_buf = kmalloc(rtattr_max * sizeof(struct rtattr *), GFP_KERNEL);
1387 	if (!rta_buf)
1388 		panic("rtnetlink_init: cannot allocate rta_buf\n");
1389 
1390 	if (register_pernet_subsys(&rtnetlink_net_ops))
1391 		panic("rtnetlink_init: cannot initialize rtnetlink\n");
1392 
1393 	netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
1394 	register_netdevice_notifier(&rtnetlink_dev_notifier);
1395 
1396 	rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink, rtnl_dump_ifinfo);
1397 	rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL);
1398 	rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL);
1399 	rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL);
1400 
1401 	rtnl_register(PF_UNSPEC, RTM_GETADDR, NULL, rtnl_dump_all);
1402 	rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all);
1403 }
1404 
1405 EXPORT_SYMBOL(__rta_fill);
1406 EXPORT_SYMBOL(rtnetlink_put_metrics);
1407 EXPORT_SYMBOL(rtnl_lock);
1408 EXPORT_SYMBOL(rtnl_trylock);
1409 EXPORT_SYMBOL(rtnl_unlock);
1410 EXPORT_SYMBOL(rtnl_is_locked);
1411 EXPORT_SYMBOL(rtnl_unicast);
1412 EXPORT_SYMBOL(rtnl_notify);
1413 EXPORT_SYMBOL(rtnl_set_sk_err);
1414 EXPORT_SYMBOL(rtnl_create_link);
1415 EXPORT_SYMBOL(ifla_policy);
1416