xref: /openbmc/linux/net/core/rtnetlink.c (revision 643d1f7f)
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 rtattr_parse(struct rtattr *tb[], int maxattr, struct rtattr *rta, int len)
86 {
87 	memset(tb, 0, sizeof(struct rtattr*)*maxattr);
88 
89 	while (RTA_OK(rta, len)) {
90 		unsigned flavor = rta->rta_type;
91 		if (flavor && flavor <= maxattr)
92 			tb[flavor-1] = rta;
93 		rta = RTA_NEXT(rta, len);
94 	}
95 	return 0;
96 }
97 
98 int __rtattr_parse_nested_compat(struct rtattr *tb[], int maxattr,
99 				 struct rtattr *rta, int len)
100 {
101 	if (RTA_PAYLOAD(rta) < len)
102 		return -1;
103 	if (RTA_PAYLOAD(rta) >= RTA_ALIGN(len) + sizeof(struct rtattr)) {
104 		rta = RTA_DATA(rta) + RTA_ALIGN(len);
105 		return rtattr_parse_nested(tb, maxattr, rta);
106 	}
107 	memset(tb, 0, sizeof(struct rtattr *) * maxattr);
108 	return 0;
109 }
110 
111 static struct rtnl_link *rtnl_msg_handlers[NPROTO];
112 
113 static inline int rtm_msgindex(int msgtype)
114 {
115 	int msgindex = msgtype - RTM_BASE;
116 
117 	/*
118 	 * msgindex < 0 implies someone tried to register a netlink
119 	 * control code. msgindex >= RTM_NR_MSGTYPES may indicate that
120 	 * the message type has not been added to linux/rtnetlink.h
121 	 */
122 	BUG_ON(msgindex < 0 || msgindex >= RTM_NR_MSGTYPES);
123 
124 	return msgindex;
125 }
126 
127 static rtnl_doit_func rtnl_get_doit(int protocol, int msgindex)
128 {
129 	struct rtnl_link *tab;
130 
131 	tab = rtnl_msg_handlers[protocol];
132 	if (tab == NULL || tab[msgindex].doit == NULL)
133 		tab = rtnl_msg_handlers[PF_UNSPEC];
134 
135 	return tab ? tab[msgindex].doit : NULL;
136 }
137 
138 static rtnl_dumpit_func rtnl_get_dumpit(int protocol, int msgindex)
139 {
140 	struct rtnl_link *tab;
141 
142 	tab = rtnl_msg_handlers[protocol];
143 	if (tab == NULL || tab[msgindex].dumpit == NULL)
144 		tab = rtnl_msg_handlers[PF_UNSPEC];
145 
146 	return tab ? tab[msgindex].dumpit : NULL;
147 }
148 
149 /**
150  * __rtnl_register - Register a rtnetlink message type
151  * @protocol: Protocol family or PF_UNSPEC
152  * @msgtype: rtnetlink message type
153  * @doit: Function pointer called for each request message
154  * @dumpit: Function pointer called for each dump request (NLM_F_DUMP) message
155  *
156  * Registers the specified function pointers (at least one of them has
157  * to be non-NULL) to be called whenever a request message for the
158  * specified protocol family and message type is received.
159  *
160  * The special protocol family PF_UNSPEC may be used to define fallback
161  * function pointers for the case when no entry for the specific protocol
162  * family exists.
163  *
164  * Returns 0 on success or a negative error code.
165  */
166 int __rtnl_register(int protocol, int msgtype,
167 		    rtnl_doit_func doit, rtnl_dumpit_func dumpit)
168 {
169 	struct rtnl_link *tab;
170 	int msgindex;
171 
172 	BUG_ON(protocol < 0 || protocol >= NPROTO);
173 	msgindex = rtm_msgindex(msgtype);
174 
175 	tab = rtnl_msg_handlers[protocol];
176 	if (tab == NULL) {
177 		tab = kcalloc(RTM_NR_MSGTYPES, sizeof(*tab), GFP_KERNEL);
178 		if (tab == NULL)
179 			return -ENOBUFS;
180 
181 		rtnl_msg_handlers[protocol] = tab;
182 	}
183 
184 	if (doit)
185 		tab[msgindex].doit = doit;
186 
187 	if (dumpit)
188 		tab[msgindex].dumpit = dumpit;
189 
190 	return 0;
191 }
192 
193 EXPORT_SYMBOL_GPL(__rtnl_register);
194 
195 /**
196  * rtnl_register - Register a rtnetlink message type
197  *
198  * Identical to __rtnl_register() but panics on failure. This is useful
199  * as failure of this function is very unlikely, it can only happen due
200  * to lack of memory when allocating the chain to store all message
201  * handlers for a protocol. Meant for use in init functions where lack
202  * of memory implies no sense in continueing.
203  */
204 void rtnl_register(int protocol, int msgtype,
205 		   rtnl_doit_func doit, rtnl_dumpit_func dumpit)
206 {
207 	if (__rtnl_register(protocol, msgtype, doit, dumpit) < 0)
208 		panic("Unable to register rtnetlink message handler, "
209 		      "protocol = %d, message type = %d\n",
210 		      protocol, msgtype);
211 }
212 
213 EXPORT_SYMBOL_GPL(rtnl_register);
214 
215 /**
216  * rtnl_unregister - Unregister a rtnetlink message type
217  * @protocol: Protocol family or PF_UNSPEC
218  * @msgtype: rtnetlink message type
219  *
220  * Returns 0 on success or a negative error code.
221  */
222 int rtnl_unregister(int protocol, int msgtype)
223 {
224 	int msgindex;
225 
226 	BUG_ON(protocol < 0 || protocol >= NPROTO);
227 	msgindex = rtm_msgindex(msgtype);
228 
229 	if (rtnl_msg_handlers[protocol] == NULL)
230 		return -ENOENT;
231 
232 	rtnl_msg_handlers[protocol][msgindex].doit = NULL;
233 	rtnl_msg_handlers[protocol][msgindex].dumpit = NULL;
234 
235 	return 0;
236 }
237 
238 EXPORT_SYMBOL_GPL(rtnl_unregister);
239 
240 /**
241  * rtnl_unregister_all - Unregister all rtnetlink message type of a protocol
242  * @protocol : Protocol family or PF_UNSPEC
243  *
244  * Identical to calling rtnl_unregster() for all registered message types
245  * of a certain protocol family.
246  */
247 void rtnl_unregister_all(int protocol)
248 {
249 	BUG_ON(protocol < 0 || protocol >= NPROTO);
250 
251 	kfree(rtnl_msg_handlers[protocol]);
252 	rtnl_msg_handlers[protocol] = NULL;
253 }
254 
255 EXPORT_SYMBOL_GPL(rtnl_unregister_all);
256 
257 static LIST_HEAD(link_ops);
258 
259 /**
260  * __rtnl_link_register - Register rtnl_link_ops with rtnetlink.
261  * @ops: struct rtnl_link_ops * to register
262  *
263  * The caller must hold the rtnl_mutex. This function should be used
264  * by drivers that create devices during module initialization. It
265  * must be called before registering the devices.
266  *
267  * Returns 0 on success or a negative error code.
268  */
269 int __rtnl_link_register(struct rtnl_link_ops *ops)
270 {
271 	if (!ops->dellink)
272 		ops->dellink = unregister_netdevice;
273 
274 	list_add_tail(&ops->list, &link_ops);
275 	return 0;
276 }
277 
278 EXPORT_SYMBOL_GPL(__rtnl_link_register);
279 
280 /**
281  * rtnl_link_register - Register rtnl_link_ops with rtnetlink.
282  * @ops: struct rtnl_link_ops * to register
283  *
284  * Returns 0 on success or a negative error code.
285  */
286 int rtnl_link_register(struct rtnl_link_ops *ops)
287 {
288 	int err;
289 
290 	rtnl_lock();
291 	err = __rtnl_link_register(ops);
292 	rtnl_unlock();
293 	return err;
294 }
295 
296 EXPORT_SYMBOL_GPL(rtnl_link_register);
297 
298 /**
299  * __rtnl_link_unregister - Unregister rtnl_link_ops from rtnetlink.
300  * @ops: struct rtnl_link_ops * to unregister
301  *
302  * The caller must hold the rtnl_mutex.
303  */
304 void __rtnl_link_unregister(struct rtnl_link_ops *ops)
305 {
306 	struct net_device *dev, *n;
307 	struct net *net;
308 
309 	for_each_net(net) {
310 restart:
311 		for_each_netdev_safe(net, dev, n) {
312 			if (dev->rtnl_link_ops == ops) {
313 				ops->dellink(dev);
314 				goto restart;
315 			}
316 		}
317 	}
318 	list_del(&ops->list);
319 }
320 
321 EXPORT_SYMBOL_GPL(__rtnl_link_unregister);
322 
323 /**
324  * rtnl_link_unregister - Unregister rtnl_link_ops from rtnetlink.
325  * @ops: struct rtnl_link_ops * to unregister
326  */
327 void rtnl_link_unregister(struct rtnl_link_ops *ops)
328 {
329 	rtnl_lock();
330 	__rtnl_link_unregister(ops);
331 	rtnl_unlock();
332 }
333 
334 EXPORT_SYMBOL_GPL(rtnl_link_unregister);
335 
336 static const struct rtnl_link_ops *rtnl_link_ops_get(const char *kind)
337 {
338 	const struct rtnl_link_ops *ops;
339 
340 	list_for_each_entry(ops, &link_ops, list) {
341 		if (!strcmp(ops->kind, kind))
342 			return ops;
343 	}
344 	return NULL;
345 }
346 
347 static size_t rtnl_link_get_size(const struct net_device *dev)
348 {
349 	const struct rtnl_link_ops *ops = dev->rtnl_link_ops;
350 	size_t size;
351 
352 	if (!ops)
353 		return 0;
354 
355 	size = nlmsg_total_size(sizeof(struct nlattr)) + /* IFLA_LINKINFO */
356 	       nlmsg_total_size(strlen(ops->kind) + 1);	 /* IFLA_INFO_KIND */
357 
358 	if (ops->get_size)
359 		/* IFLA_INFO_DATA + nested data */
360 		size += nlmsg_total_size(sizeof(struct nlattr)) +
361 			ops->get_size(dev);
362 
363 	if (ops->get_xstats_size)
364 		size += ops->get_xstats_size(dev);	/* IFLA_INFO_XSTATS */
365 
366 	return size;
367 }
368 
369 static int rtnl_link_fill(struct sk_buff *skb, const struct net_device *dev)
370 {
371 	const struct rtnl_link_ops *ops = dev->rtnl_link_ops;
372 	struct nlattr *linkinfo, *data;
373 	int err = -EMSGSIZE;
374 
375 	linkinfo = nla_nest_start(skb, IFLA_LINKINFO);
376 	if (linkinfo == NULL)
377 		goto out;
378 
379 	if (nla_put_string(skb, IFLA_INFO_KIND, ops->kind) < 0)
380 		goto err_cancel_link;
381 	if (ops->fill_xstats) {
382 		err = ops->fill_xstats(skb, dev);
383 		if (err < 0)
384 			goto err_cancel_link;
385 	}
386 	if (ops->fill_info) {
387 		data = nla_nest_start(skb, IFLA_INFO_DATA);
388 		if (data == NULL)
389 			goto err_cancel_link;
390 		err = ops->fill_info(skb, dev);
391 		if (err < 0)
392 			goto err_cancel_data;
393 		nla_nest_end(skb, data);
394 	}
395 
396 	nla_nest_end(skb, linkinfo);
397 	return 0;
398 
399 err_cancel_data:
400 	nla_nest_cancel(skb, data);
401 err_cancel_link:
402 	nla_nest_cancel(skb, linkinfo);
403 out:
404 	return err;
405 }
406 
407 static const int rtm_min[RTM_NR_FAMILIES] =
408 {
409 	[RTM_FAM(RTM_NEWLINK)]      = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
410 	[RTM_FAM(RTM_NEWADDR)]      = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
411 	[RTM_FAM(RTM_NEWROUTE)]     = NLMSG_LENGTH(sizeof(struct rtmsg)),
412 	[RTM_FAM(RTM_NEWRULE)]      = NLMSG_LENGTH(sizeof(struct fib_rule_hdr)),
413 	[RTM_FAM(RTM_NEWQDISC)]     = NLMSG_LENGTH(sizeof(struct tcmsg)),
414 	[RTM_FAM(RTM_NEWTCLASS)]    = NLMSG_LENGTH(sizeof(struct tcmsg)),
415 	[RTM_FAM(RTM_NEWTFILTER)]   = NLMSG_LENGTH(sizeof(struct tcmsg)),
416 	[RTM_FAM(RTM_NEWACTION)]    = NLMSG_LENGTH(sizeof(struct tcamsg)),
417 	[RTM_FAM(RTM_GETMULTICAST)] = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
418 	[RTM_FAM(RTM_GETANYCAST)]   = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
419 };
420 
421 static const int rta_max[RTM_NR_FAMILIES] =
422 {
423 	[RTM_FAM(RTM_NEWLINK)]      = IFLA_MAX,
424 	[RTM_FAM(RTM_NEWADDR)]      = IFA_MAX,
425 	[RTM_FAM(RTM_NEWROUTE)]     = RTA_MAX,
426 	[RTM_FAM(RTM_NEWRULE)]      = FRA_MAX,
427 	[RTM_FAM(RTM_NEWQDISC)]     = TCA_MAX,
428 	[RTM_FAM(RTM_NEWTCLASS)]    = TCA_MAX,
429 	[RTM_FAM(RTM_NEWTFILTER)]   = TCA_MAX,
430 	[RTM_FAM(RTM_NEWACTION)]    = TCAA_MAX,
431 };
432 
433 void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
434 {
435 	struct rtattr *rta;
436 	int size = RTA_LENGTH(attrlen);
437 
438 	rta = (struct rtattr*)skb_put(skb, RTA_ALIGN(size));
439 	rta->rta_type = attrtype;
440 	rta->rta_len = size;
441 	memcpy(RTA_DATA(rta), data, attrlen);
442 	memset(RTA_DATA(rta) + attrlen, 0, RTA_ALIGN(size) - size);
443 }
444 
445 size_t rtattr_strlcpy(char *dest, const struct rtattr *rta, size_t size)
446 {
447 	size_t ret = RTA_PAYLOAD(rta);
448 	char *src = RTA_DATA(rta);
449 
450 	if (ret > 0 && src[ret - 1] == '\0')
451 		ret--;
452 	if (size > 0) {
453 		size_t len = (ret >= size) ? size - 1 : ret;
454 		memset(dest, 0, size);
455 		memcpy(dest, src, len);
456 	}
457 	return ret;
458 }
459 
460 int rtnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, unsigned group, int echo)
461 {
462 	struct sock *rtnl = net->rtnl;
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, struct net *net, u32 pid)
475 {
476 	struct sock *rtnl = net->rtnl;
477 
478 	return nlmsg_unicast(rtnl, skb, pid);
479 }
480 
481 int rtnl_notify(struct sk_buff *skb, struct net *net, u32 pid, u32 group,
482 		struct nlmsghdr *nlh, gfp_t flags)
483 {
484 	struct sock *rtnl = net->rtnl;
485 	int report = 0;
486 
487 	if (nlh)
488 		report = nlmsg_report(nlh);
489 
490 	return nlmsg_notify(rtnl, skb, pid, group, report, flags);
491 }
492 
493 void rtnl_set_sk_err(struct net *net, u32 group, int error)
494 {
495 	struct sock *rtnl = net->rtnl;
496 
497 	netlink_set_err(rtnl, 0, group, error);
498 }
499 
500 int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics)
501 {
502 	struct nlattr *mx;
503 	int i, valid = 0;
504 
505 	mx = nla_nest_start(skb, RTA_METRICS);
506 	if (mx == NULL)
507 		return -ENOBUFS;
508 
509 	for (i = 0; i < RTAX_MAX; i++) {
510 		if (metrics[i]) {
511 			valid++;
512 			NLA_PUT_U32(skb, i+1, metrics[i]);
513 		}
514 	}
515 
516 	if (!valid) {
517 		nla_nest_cancel(skb, mx);
518 		return 0;
519 	}
520 
521 	return nla_nest_end(skb, mx);
522 
523 nla_put_failure:
524 	return nla_nest_cancel(skb, mx);
525 }
526 
527 int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id,
528 		       u32 ts, u32 tsage, long expires, u32 error)
529 {
530 	struct rta_cacheinfo ci = {
531 		.rta_lastuse = jiffies_to_clock_t(jiffies - dst->lastuse),
532 		.rta_used = dst->__use,
533 		.rta_clntref = atomic_read(&(dst->__refcnt)),
534 		.rta_error = error,
535 		.rta_id =  id,
536 		.rta_ts = ts,
537 		.rta_tsage = tsage,
538 	};
539 
540 	if (expires)
541 		ci.rta_expires = jiffies_to_clock_t(expires);
542 
543 	return nla_put(skb, RTA_CACHEINFO, sizeof(ci), &ci);
544 }
545 
546 EXPORT_SYMBOL_GPL(rtnl_put_cacheinfo);
547 
548 static void set_operstate(struct net_device *dev, unsigned char transition)
549 {
550 	unsigned char operstate = dev->operstate;
551 
552 	switch(transition) {
553 	case IF_OPER_UP:
554 		if ((operstate == IF_OPER_DORMANT ||
555 		     operstate == IF_OPER_UNKNOWN) &&
556 		    !netif_dormant(dev))
557 			operstate = IF_OPER_UP;
558 		break;
559 
560 	case IF_OPER_DORMANT:
561 		if (operstate == IF_OPER_UP ||
562 		    operstate == IF_OPER_UNKNOWN)
563 			operstate = IF_OPER_DORMANT;
564 		break;
565 	}
566 
567 	if (dev->operstate != operstate) {
568 		write_lock_bh(&dev_base_lock);
569 		dev->operstate = operstate;
570 		write_unlock_bh(&dev_base_lock);
571 		netdev_state_change(dev);
572 	}
573 }
574 
575 static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
576 				 struct net_device_stats *b)
577 {
578 	a->rx_packets = b->rx_packets;
579 	a->tx_packets = b->tx_packets;
580 	a->rx_bytes = b->rx_bytes;
581 	a->tx_bytes = b->tx_bytes;
582 	a->rx_errors = b->rx_errors;
583 	a->tx_errors = b->tx_errors;
584 	a->rx_dropped = b->rx_dropped;
585 	a->tx_dropped = b->tx_dropped;
586 
587 	a->multicast = b->multicast;
588 	a->collisions = b->collisions;
589 
590 	a->rx_length_errors = b->rx_length_errors;
591 	a->rx_over_errors = b->rx_over_errors;
592 	a->rx_crc_errors = b->rx_crc_errors;
593 	a->rx_frame_errors = b->rx_frame_errors;
594 	a->rx_fifo_errors = b->rx_fifo_errors;
595 	a->rx_missed_errors = b->rx_missed_errors;
596 
597 	a->tx_aborted_errors = b->tx_aborted_errors;
598 	a->tx_carrier_errors = b->tx_carrier_errors;
599 	a->tx_fifo_errors = b->tx_fifo_errors;
600 	a->tx_heartbeat_errors = b->tx_heartbeat_errors;
601 	a->tx_window_errors = b->tx_window_errors;
602 
603 	a->rx_compressed = b->rx_compressed;
604 	a->tx_compressed = b->tx_compressed;
605 };
606 
607 static inline size_t if_nlmsg_size(const struct net_device *dev)
608 {
609 	return NLMSG_ALIGN(sizeof(struct ifinfomsg))
610 	       + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
611 	       + nla_total_size(IFNAMSIZ) /* IFLA_QDISC */
612 	       + nla_total_size(sizeof(struct rtnl_link_ifmap))
613 	       + nla_total_size(sizeof(struct rtnl_link_stats))
614 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
615 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_BROADCAST */
616 	       + nla_total_size(4) /* IFLA_TXQLEN */
617 	       + nla_total_size(4) /* IFLA_WEIGHT */
618 	       + nla_total_size(4) /* IFLA_MTU */
619 	       + nla_total_size(4) /* IFLA_LINK */
620 	       + nla_total_size(4) /* IFLA_MASTER */
621 	       + nla_total_size(1) /* IFLA_OPERSTATE */
622 	       + nla_total_size(1) /* IFLA_LINKMODE */
623 	       + rtnl_link_get_size(dev); /* IFLA_LINKINFO */
624 }
625 
626 static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
627 			    int type, u32 pid, u32 seq, u32 change,
628 			    unsigned int flags)
629 {
630 	struct ifinfomsg *ifm;
631 	struct nlmsghdr *nlh;
632 
633 	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ifm), flags);
634 	if (nlh == NULL)
635 		return -EMSGSIZE;
636 
637 	ifm = nlmsg_data(nlh);
638 	ifm->ifi_family = AF_UNSPEC;
639 	ifm->__ifi_pad = 0;
640 	ifm->ifi_type = dev->type;
641 	ifm->ifi_index = dev->ifindex;
642 	ifm->ifi_flags = dev_get_flags(dev);
643 	ifm->ifi_change = change;
644 
645 	NLA_PUT_STRING(skb, IFLA_IFNAME, dev->name);
646 	NLA_PUT_U32(skb, IFLA_TXQLEN, dev->tx_queue_len);
647 	NLA_PUT_U8(skb, IFLA_OPERSTATE,
648 		   netif_running(dev) ? dev->operstate : IF_OPER_DOWN);
649 	NLA_PUT_U8(skb, IFLA_LINKMODE, dev->link_mode);
650 	NLA_PUT_U32(skb, IFLA_MTU, dev->mtu);
651 
652 	if (dev->ifindex != dev->iflink)
653 		NLA_PUT_U32(skb, IFLA_LINK, dev->iflink);
654 
655 	if (dev->master)
656 		NLA_PUT_U32(skb, IFLA_MASTER, dev->master->ifindex);
657 
658 	if (dev->qdisc_sleeping)
659 		NLA_PUT_STRING(skb, IFLA_QDISC, dev->qdisc_sleeping->ops->id);
660 
661 	if (1) {
662 		struct rtnl_link_ifmap map = {
663 			.mem_start   = dev->mem_start,
664 			.mem_end     = dev->mem_end,
665 			.base_addr   = dev->base_addr,
666 			.irq         = dev->irq,
667 			.dma         = dev->dma,
668 			.port        = dev->if_port,
669 		};
670 		NLA_PUT(skb, IFLA_MAP, sizeof(map), &map);
671 	}
672 
673 	if (dev->addr_len) {
674 		NLA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr);
675 		NLA_PUT(skb, IFLA_BROADCAST, dev->addr_len, dev->broadcast);
676 	}
677 
678 	if (dev->get_stats) {
679 		struct net_device_stats *stats = dev->get_stats(dev);
680 		if (stats) {
681 			struct nlattr *attr;
682 
683 			attr = nla_reserve(skb, IFLA_STATS,
684 					   sizeof(struct rtnl_link_stats));
685 			if (attr == NULL)
686 				goto nla_put_failure;
687 
688 			copy_rtnl_link_stats(nla_data(attr), stats);
689 		}
690 	}
691 
692 	if (dev->rtnl_link_ops) {
693 		if (rtnl_link_fill(skb, dev) < 0)
694 			goto nla_put_failure;
695 	}
696 
697 	return nlmsg_end(skb, nlh);
698 
699 nla_put_failure:
700 	nlmsg_cancel(skb, nlh);
701 	return -EMSGSIZE;
702 }
703 
704 static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
705 {
706 	struct net *net = skb->sk->sk_net;
707 	int idx;
708 	int s_idx = cb->args[0];
709 	struct net_device *dev;
710 
711 	idx = 0;
712 	for_each_netdev(net, dev) {
713 		if (idx < s_idx)
714 			goto cont;
715 		if (rtnl_fill_ifinfo(skb, dev, RTM_NEWLINK,
716 				     NETLINK_CB(cb->skb).pid,
717 				     cb->nlh->nlmsg_seq, 0, NLM_F_MULTI) <= 0)
718 			break;
719 cont:
720 		idx++;
721 	}
722 	cb->args[0] = idx;
723 
724 	return skb->len;
725 }
726 
727 const struct nla_policy ifla_policy[IFLA_MAX+1] = {
728 	[IFLA_IFNAME]		= { .type = NLA_STRING, .len = IFNAMSIZ-1 },
729 	[IFLA_ADDRESS]		= { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
730 	[IFLA_BROADCAST]	= { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
731 	[IFLA_MAP]		= { .len = sizeof(struct rtnl_link_ifmap) },
732 	[IFLA_MTU]		= { .type = NLA_U32 },
733 	[IFLA_TXQLEN]		= { .type = NLA_U32 },
734 	[IFLA_WEIGHT]		= { .type = NLA_U32 },
735 	[IFLA_OPERSTATE]	= { .type = NLA_U8 },
736 	[IFLA_LINKMODE]		= { .type = NLA_U8 },
737 	[IFLA_NET_NS_PID]	= { .type = NLA_U32 },
738 };
739 
740 static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
741 	[IFLA_INFO_KIND]	= { .type = NLA_STRING },
742 	[IFLA_INFO_DATA]	= { .type = NLA_NESTED },
743 };
744 
745 static struct net *get_net_ns_by_pid(pid_t pid)
746 {
747 	struct task_struct *tsk;
748 	struct net *net;
749 
750 	/* Lookup the network namespace */
751 	net = ERR_PTR(-ESRCH);
752 	rcu_read_lock();
753 	tsk = find_task_by_vpid(pid);
754 	if (tsk) {
755 		struct nsproxy *nsproxy;
756 		nsproxy = task_nsproxy(tsk);
757 		if (nsproxy)
758 			net = get_net(nsproxy->net_ns);
759 	}
760 	rcu_read_unlock();
761 	return net;
762 }
763 
764 static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
765 		      struct nlattr **tb, char *ifname, int modified)
766 {
767 	int send_addr_notify = 0;
768 	int err;
769 
770 	if (tb[IFLA_NET_NS_PID]) {
771 		struct net *net;
772 		net = get_net_ns_by_pid(nla_get_u32(tb[IFLA_NET_NS_PID]));
773 		if (IS_ERR(net)) {
774 			err = PTR_ERR(net);
775 			goto errout;
776 		}
777 		err = dev_change_net_namespace(dev, net, ifname);
778 		put_net(net);
779 		if (err)
780 			goto errout;
781 		modified = 1;
782 	}
783 
784 	if (tb[IFLA_MAP]) {
785 		struct rtnl_link_ifmap *u_map;
786 		struct ifmap k_map;
787 
788 		if (!dev->set_config) {
789 			err = -EOPNOTSUPP;
790 			goto errout;
791 		}
792 
793 		if (!netif_device_present(dev)) {
794 			err = -ENODEV;
795 			goto errout;
796 		}
797 
798 		u_map = nla_data(tb[IFLA_MAP]);
799 		k_map.mem_start = (unsigned long) u_map->mem_start;
800 		k_map.mem_end = (unsigned long) u_map->mem_end;
801 		k_map.base_addr = (unsigned short) u_map->base_addr;
802 		k_map.irq = (unsigned char) u_map->irq;
803 		k_map.dma = (unsigned char) u_map->dma;
804 		k_map.port = (unsigned char) u_map->port;
805 
806 		err = dev->set_config(dev, &k_map);
807 		if (err < 0)
808 			goto errout;
809 
810 		modified = 1;
811 	}
812 
813 	if (tb[IFLA_ADDRESS]) {
814 		struct sockaddr *sa;
815 		int len;
816 
817 		if (!dev->set_mac_address) {
818 			err = -EOPNOTSUPP;
819 			goto errout;
820 		}
821 
822 		if (!netif_device_present(dev)) {
823 			err = -ENODEV;
824 			goto errout;
825 		}
826 
827 		len = sizeof(sa_family_t) + dev->addr_len;
828 		sa = kmalloc(len, GFP_KERNEL);
829 		if (!sa) {
830 			err = -ENOMEM;
831 			goto errout;
832 		}
833 		sa->sa_family = dev->type;
834 		memcpy(sa->sa_data, nla_data(tb[IFLA_ADDRESS]),
835 		       dev->addr_len);
836 		err = dev->set_mac_address(dev, sa);
837 		kfree(sa);
838 		if (err)
839 			goto errout;
840 		send_addr_notify = 1;
841 		modified = 1;
842 	}
843 
844 	if (tb[IFLA_MTU]) {
845 		err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
846 		if (err < 0)
847 			goto errout;
848 		modified = 1;
849 	}
850 
851 	/*
852 	 * Interface selected by interface index but interface
853 	 * name provided implies that a name change has been
854 	 * requested.
855 	 */
856 	if (ifm->ifi_index > 0 && ifname[0]) {
857 		err = dev_change_name(dev, ifname);
858 		if (err < 0)
859 			goto errout;
860 		modified = 1;
861 	}
862 
863 	if (tb[IFLA_BROADCAST]) {
864 		nla_memcpy(dev->broadcast, tb[IFLA_BROADCAST], dev->addr_len);
865 		send_addr_notify = 1;
866 	}
867 
868 	if (ifm->ifi_flags || ifm->ifi_change) {
869 		unsigned int flags = ifm->ifi_flags;
870 
871 		/* bugwards compatibility: ifi_change == 0 is treated as ~0 */
872 		if (ifm->ifi_change)
873 			flags = (flags & ifm->ifi_change) |
874 				(dev->flags & ~ifm->ifi_change);
875 		dev_change_flags(dev, flags);
876 	}
877 
878 	if (tb[IFLA_TXQLEN])
879 		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
880 
881 	if (tb[IFLA_OPERSTATE])
882 		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
883 
884 	if (tb[IFLA_LINKMODE]) {
885 		write_lock_bh(&dev_base_lock);
886 		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
887 		write_unlock_bh(&dev_base_lock);
888 	}
889 
890 	err = 0;
891 
892 errout:
893 	if (err < 0 && modified && net_ratelimit())
894 		printk(KERN_WARNING "A link change request failed with "
895 		       "some changes comitted already. Interface %s may "
896 		       "have been left with an inconsistent configuration, "
897 		       "please check.\n", dev->name);
898 
899 	if (send_addr_notify)
900 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
901 	return err;
902 }
903 
904 static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
905 {
906 	struct net *net = skb->sk->sk_net;
907 	struct ifinfomsg *ifm;
908 	struct net_device *dev;
909 	int err;
910 	struct nlattr *tb[IFLA_MAX+1];
911 	char ifname[IFNAMSIZ];
912 
913 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
914 	if (err < 0)
915 		goto errout;
916 
917 	if (tb[IFLA_IFNAME])
918 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
919 	else
920 		ifname[0] = '\0';
921 
922 	err = -EINVAL;
923 	ifm = nlmsg_data(nlh);
924 	if (ifm->ifi_index > 0)
925 		dev = dev_get_by_index(net, ifm->ifi_index);
926 	else if (tb[IFLA_IFNAME])
927 		dev = dev_get_by_name(net, ifname);
928 	else
929 		goto errout;
930 
931 	if (dev == NULL) {
932 		err = -ENODEV;
933 		goto errout;
934 	}
935 
936 	if (tb[IFLA_ADDRESS] &&
937 	    nla_len(tb[IFLA_ADDRESS]) < dev->addr_len)
938 		goto errout_dev;
939 
940 	if (tb[IFLA_BROADCAST] &&
941 	    nla_len(tb[IFLA_BROADCAST]) < dev->addr_len)
942 		goto errout_dev;
943 
944 	err = do_setlink(dev, ifm, tb, ifname, 0);
945 errout_dev:
946 	dev_put(dev);
947 errout:
948 	return err;
949 }
950 
951 static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
952 {
953 	struct net *net = skb->sk->sk_net;
954 	const struct rtnl_link_ops *ops;
955 	struct net_device *dev;
956 	struct ifinfomsg *ifm;
957 	char ifname[IFNAMSIZ];
958 	struct nlattr *tb[IFLA_MAX+1];
959 	int err;
960 
961 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
962 	if (err < 0)
963 		return err;
964 
965 	if (tb[IFLA_IFNAME])
966 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
967 
968 	ifm = nlmsg_data(nlh);
969 	if (ifm->ifi_index > 0)
970 		dev = __dev_get_by_index(net, ifm->ifi_index);
971 	else if (tb[IFLA_IFNAME])
972 		dev = __dev_get_by_name(net, ifname);
973 	else
974 		return -EINVAL;
975 
976 	if (!dev)
977 		return -ENODEV;
978 
979 	ops = dev->rtnl_link_ops;
980 	if (!ops)
981 		return -EOPNOTSUPP;
982 
983 	ops->dellink(dev);
984 	return 0;
985 }
986 
987 struct net_device *rtnl_create_link(struct net *net, char *ifname,
988 		const struct rtnl_link_ops *ops, struct nlattr *tb[])
989 {
990 	int err;
991 	struct net_device *dev;
992 
993 	err = -ENOMEM;
994 	dev = alloc_netdev(ops->priv_size, ifname, ops->setup);
995 	if (!dev)
996 		goto err;
997 
998 	if (strchr(dev->name, '%')) {
999 		err = dev_alloc_name(dev, dev->name);
1000 		if (err < 0)
1001 			goto err_free;
1002 	}
1003 
1004 	dev->nd_net = net;
1005 	dev->rtnl_link_ops = ops;
1006 
1007 	if (tb[IFLA_MTU])
1008 		dev->mtu = nla_get_u32(tb[IFLA_MTU]);
1009 	if (tb[IFLA_ADDRESS])
1010 		memcpy(dev->dev_addr, nla_data(tb[IFLA_ADDRESS]),
1011 				nla_len(tb[IFLA_ADDRESS]));
1012 	if (tb[IFLA_BROADCAST])
1013 		memcpy(dev->broadcast, nla_data(tb[IFLA_BROADCAST]),
1014 				nla_len(tb[IFLA_BROADCAST]));
1015 	if (tb[IFLA_TXQLEN])
1016 		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
1017 	if (tb[IFLA_OPERSTATE])
1018 		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
1019 	if (tb[IFLA_LINKMODE])
1020 		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
1021 
1022 	return dev;
1023 
1024 err_free:
1025 	free_netdev(dev);
1026 err:
1027 	return ERR_PTR(err);
1028 }
1029 
1030 static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
1031 {
1032 	struct net *net = skb->sk->sk_net;
1033 	const struct rtnl_link_ops *ops;
1034 	struct net_device *dev;
1035 	struct ifinfomsg *ifm;
1036 	char kind[MODULE_NAME_LEN];
1037 	char ifname[IFNAMSIZ];
1038 	struct nlattr *tb[IFLA_MAX+1];
1039 	struct nlattr *linkinfo[IFLA_INFO_MAX+1];
1040 	int err;
1041 
1042 #ifdef CONFIG_KMOD
1043 replay:
1044 #endif
1045 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
1046 	if (err < 0)
1047 		return err;
1048 
1049 	if (tb[IFLA_IFNAME])
1050 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
1051 	else
1052 		ifname[0] = '\0';
1053 
1054 	ifm = nlmsg_data(nlh);
1055 	if (ifm->ifi_index > 0)
1056 		dev = __dev_get_by_index(net, ifm->ifi_index);
1057 	else if (ifname[0])
1058 		dev = __dev_get_by_name(net, ifname);
1059 	else
1060 		dev = NULL;
1061 
1062 	if (tb[IFLA_LINKINFO]) {
1063 		err = nla_parse_nested(linkinfo, IFLA_INFO_MAX,
1064 				       tb[IFLA_LINKINFO], ifla_info_policy);
1065 		if (err < 0)
1066 			return err;
1067 	} else
1068 		memset(linkinfo, 0, sizeof(linkinfo));
1069 
1070 	if (linkinfo[IFLA_INFO_KIND]) {
1071 		nla_strlcpy(kind, linkinfo[IFLA_INFO_KIND], sizeof(kind));
1072 		ops = rtnl_link_ops_get(kind);
1073 	} else {
1074 		kind[0] = '\0';
1075 		ops = NULL;
1076 	}
1077 
1078 	if (1) {
1079 		struct nlattr *attr[ops ? ops->maxtype + 1 : 0], **data = NULL;
1080 
1081 		if (ops) {
1082 			if (ops->maxtype && linkinfo[IFLA_INFO_DATA]) {
1083 				err = nla_parse_nested(attr, ops->maxtype,
1084 						       linkinfo[IFLA_INFO_DATA],
1085 						       ops->policy);
1086 				if (err < 0)
1087 					return err;
1088 				data = attr;
1089 			}
1090 			if (ops->validate) {
1091 				err = ops->validate(tb, data);
1092 				if (err < 0)
1093 					return err;
1094 			}
1095 		}
1096 
1097 		if (dev) {
1098 			int modified = 0;
1099 
1100 			if (nlh->nlmsg_flags & NLM_F_EXCL)
1101 				return -EEXIST;
1102 			if (nlh->nlmsg_flags & NLM_F_REPLACE)
1103 				return -EOPNOTSUPP;
1104 
1105 			if (linkinfo[IFLA_INFO_DATA]) {
1106 				if (!ops || ops != dev->rtnl_link_ops ||
1107 				    !ops->changelink)
1108 					return -EOPNOTSUPP;
1109 
1110 				err = ops->changelink(dev, tb, data);
1111 				if (err < 0)
1112 					return err;
1113 				modified = 1;
1114 			}
1115 
1116 			return do_setlink(dev, ifm, tb, ifname, modified);
1117 		}
1118 
1119 		if (!(nlh->nlmsg_flags & NLM_F_CREATE))
1120 			return -ENODEV;
1121 
1122 		if (ifm->ifi_index || ifm->ifi_flags || ifm->ifi_change)
1123 			return -EOPNOTSUPP;
1124 		if (tb[IFLA_MAP] || tb[IFLA_MASTER] || tb[IFLA_PROTINFO])
1125 			return -EOPNOTSUPP;
1126 
1127 		if (!ops) {
1128 #ifdef CONFIG_KMOD
1129 			if (kind[0]) {
1130 				__rtnl_unlock();
1131 				request_module("rtnl-link-%s", kind);
1132 				rtnl_lock();
1133 				ops = rtnl_link_ops_get(kind);
1134 				if (ops)
1135 					goto replay;
1136 			}
1137 #endif
1138 			return -EOPNOTSUPP;
1139 		}
1140 
1141 		if (!ifname[0])
1142 			snprintf(ifname, IFNAMSIZ, "%s%%d", ops->kind);
1143 
1144 		dev = rtnl_create_link(net, ifname, ops, tb);
1145 
1146 		if (IS_ERR(dev))
1147 			err = PTR_ERR(dev);
1148 		else if (ops->newlink)
1149 			err = ops->newlink(dev, tb, data);
1150 		else
1151 			err = register_netdevice(dev);
1152 
1153 		if (err < 0 && !IS_ERR(dev))
1154 			free_netdev(dev);
1155 		return err;
1156 	}
1157 }
1158 
1159 static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
1160 {
1161 	struct net *net = skb->sk->sk_net;
1162 	struct ifinfomsg *ifm;
1163 	struct nlattr *tb[IFLA_MAX+1];
1164 	struct net_device *dev = NULL;
1165 	struct sk_buff *nskb;
1166 	int err;
1167 
1168 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
1169 	if (err < 0)
1170 		return err;
1171 
1172 	ifm = nlmsg_data(nlh);
1173 	if (ifm->ifi_index > 0) {
1174 		dev = dev_get_by_index(net, ifm->ifi_index);
1175 		if (dev == NULL)
1176 			return -ENODEV;
1177 	} else
1178 		return -EINVAL;
1179 
1180 	nskb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
1181 	if (nskb == NULL) {
1182 		err = -ENOBUFS;
1183 		goto errout;
1184 	}
1185 
1186 	err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).pid,
1187 			       nlh->nlmsg_seq, 0, 0);
1188 	if (err < 0) {
1189 		/* -EMSGSIZE implies BUG in if_nlmsg_size */
1190 		WARN_ON(err == -EMSGSIZE);
1191 		kfree_skb(nskb);
1192 		goto errout;
1193 	}
1194 	err = rtnl_unicast(nskb, net, NETLINK_CB(skb).pid);
1195 errout:
1196 	dev_put(dev);
1197 
1198 	return err;
1199 }
1200 
1201 static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
1202 {
1203 	int idx;
1204 	int s_idx = cb->family;
1205 
1206 	if (s_idx == 0)
1207 		s_idx = 1;
1208 	for (idx=1; idx<NPROTO; idx++) {
1209 		int type = cb->nlh->nlmsg_type-RTM_BASE;
1210 		if (idx < s_idx || idx == PF_PACKET)
1211 			continue;
1212 		if (rtnl_msg_handlers[idx] == NULL ||
1213 		    rtnl_msg_handlers[idx][type].dumpit == NULL)
1214 			continue;
1215 		if (idx > s_idx)
1216 			memset(&cb->args[0], 0, sizeof(cb->args));
1217 		if (rtnl_msg_handlers[idx][type].dumpit(skb, cb))
1218 			break;
1219 	}
1220 	cb->family = idx;
1221 
1222 	return skb->len;
1223 }
1224 
1225 void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change)
1226 {
1227 	struct net *net = dev->nd_net;
1228 	struct sk_buff *skb;
1229 	int err = -ENOBUFS;
1230 
1231 	skb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
1232 	if (skb == NULL)
1233 		goto errout;
1234 
1235 	err = rtnl_fill_ifinfo(skb, dev, type, 0, 0, change, 0);
1236 	if (err < 0) {
1237 		/* -EMSGSIZE implies BUG in if_nlmsg_size() */
1238 		WARN_ON(err == -EMSGSIZE);
1239 		kfree_skb(skb);
1240 		goto errout;
1241 	}
1242 	err = rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_KERNEL);
1243 errout:
1244 	if (err < 0)
1245 		rtnl_set_sk_err(net, RTNLGRP_LINK, err);
1246 }
1247 
1248 /* Protected by RTNL sempahore.  */
1249 static struct rtattr **rta_buf;
1250 static int rtattr_max;
1251 
1252 /* Process one rtnetlink message. */
1253 
1254 static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
1255 {
1256 	struct net *net = skb->sk->sk_net;
1257 	rtnl_doit_func doit;
1258 	int sz_idx, kind;
1259 	int min_len;
1260 	int family;
1261 	int type;
1262 	int err;
1263 
1264 	type = nlh->nlmsg_type;
1265 	if (type > RTM_MAX)
1266 		return -EOPNOTSUPP;
1267 
1268 	type -= RTM_BASE;
1269 
1270 	/* All the messages must have at least 1 byte length */
1271 	if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct rtgenmsg)))
1272 		return 0;
1273 
1274 	family = ((struct rtgenmsg*)NLMSG_DATA(nlh))->rtgen_family;
1275 	if (family >= NPROTO)
1276 		return -EAFNOSUPPORT;
1277 
1278 	sz_idx = type>>2;
1279 	kind = type&3;
1280 
1281 	if (kind != 2 && security_netlink_recv(skb, CAP_NET_ADMIN))
1282 		return -EPERM;
1283 
1284 	if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
1285 		struct sock *rtnl;
1286 		rtnl_dumpit_func dumpit;
1287 
1288 		dumpit = rtnl_get_dumpit(family, type);
1289 		if (dumpit == NULL)
1290 			return -EOPNOTSUPP;
1291 
1292 		__rtnl_unlock();
1293 		rtnl = net->rtnl;
1294 		err = netlink_dump_start(rtnl, skb, nlh, dumpit, NULL);
1295 		rtnl_lock();
1296 		return err;
1297 	}
1298 
1299 	memset(rta_buf, 0, (rtattr_max * sizeof(struct rtattr *)));
1300 
1301 	min_len = rtm_min[sz_idx];
1302 	if (nlh->nlmsg_len < min_len)
1303 		return -EINVAL;
1304 
1305 	if (nlh->nlmsg_len > min_len) {
1306 		int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
1307 		struct rtattr *attr = (void*)nlh + NLMSG_ALIGN(min_len);
1308 
1309 		while (RTA_OK(attr, attrlen)) {
1310 			unsigned flavor = attr->rta_type;
1311 			if (flavor) {
1312 				if (flavor > rta_max[sz_idx])
1313 					return -EINVAL;
1314 				rta_buf[flavor-1] = attr;
1315 			}
1316 			attr = RTA_NEXT(attr, attrlen);
1317 		}
1318 	}
1319 
1320 	doit = rtnl_get_doit(family, type);
1321 	if (doit == NULL)
1322 		return -EOPNOTSUPP;
1323 
1324 	return doit(skb, nlh, (void *)&rta_buf[0]);
1325 }
1326 
1327 static void rtnetlink_rcv(struct sk_buff *skb)
1328 {
1329 	rtnl_lock();
1330 	netlink_rcv_skb(skb, &rtnetlink_rcv_msg);
1331 	rtnl_unlock();
1332 }
1333 
1334 static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr)
1335 {
1336 	struct net_device *dev = ptr;
1337 
1338 	switch (event) {
1339 	case NETDEV_UNREGISTER:
1340 		rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
1341 		break;
1342 	case NETDEV_REGISTER:
1343 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
1344 		break;
1345 	case NETDEV_UP:
1346 	case NETDEV_DOWN:
1347 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1348 		break;
1349 	case NETDEV_CHANGE:
1350 	case NETDEV_GOING_DOWN:
1351 		break;
1352 	default:
1353 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
1354 		break;
1355 	}
1356 	return NOTIFY_DONE;
1357 }
1358 
1359 static struct notifier_block rtnetlink_dev_notifier = {
1360 	.notifier_call	= rtnetlink_event,
1361 };
1362 
1363 
1364 static int rtnetlink_net_init(struct net *net)
1365 {
1366 	struct sock *sk;
1367 	sk = netlink_kernel_create(net, NETLINK_ROUTE, RTNLGRP_MAX,
1368 				   rtnetlink_rcv, &rtnl_mutex, THIS_MODULE);
1369 	if (!sk)
1370 		return -ENOMEM;
1371 	net->rtnl = sk;
1372 	return 0;
1373 }
1374 
1375 static void rtnetlink_net_exit(struct net *net)
1376 {
1377 	netlink_kernel_release(net->rtnl);
1378 	net->rtnl = NULL;
1379 }
1380 
1381 static struct pernet_operations rtnetlink_net_ops = {
1382 	.init = rtnetlink_net_init,
1383 	.exit = rtnetlink_net_exit,
1384 };
1385 
1386 void __init rtnetlink_init(void)
1387 {
1388 	int i;
1389 
1390 	rtattr_max = 0;
1391 	for (i = 0; i < ARRAY_SIZE(rta_max); i++)
1392 		if (rta_max[i] > rtattr_max)
1393 			rtattr_max = rta_max[i];
1394 	rta_buf = kmalloc(rtattr_max * sizeof(struct rtattr *), GFP_KERNEL);
1395 	if (!rta_buf)
1396 		panic("rtnetlink_init: cannot allocate rta_buf\n");
1397 
1398 	if (register_pernet_subsys(&rtnetlink_net_ops))
1399 		panic("rtnetlink_init: cannot initialize rtnetlink\n");
1400 
1401 	netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
1402 	register_netdevice_notifier(&rtnetlink_dev_notifier);
1403 
1404 	rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink, rtnl_dump_ifinfo);
1405 	rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL);
1406 	rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL);
1407 	rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL);
1408 
1409 	rtnl_register(PF_UNSPEC, RTM_GETADDR, NULL, rtnl_dump_all);
1410 	rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all);
1411 }
1412 
1413 EXPORT_SYMBOL(__rta_fill);
1414 EXPORT_SYMBOL(rtattr_strlcpy);
1415 EXPORT_SYMBOL(rtattr_parse);
1416 EXPORT_SYMBOL(__rtattr_parse_nested_compat);
1417 EXPORT_SYMBOL(rtnetlink_put_metrics);
1418 EXPORT_SYMBOL(rtnl_lock);
1419 EXPORT_SYMBOL(rtnl_trylock);
1420 EXPORT_SYMBOL(rtnl_unlock);
1421 EXPORT_SYMBOL(rtnl_unicast);
1422 EXPORT_SYMBOL(rtnl_notify);
1423 EXPORT_SYMBOL(rtnl_set_sk_err);
1424 EXPORT_SYMBOL(rtnl_create_link);
1425 EXPORT_SYMBOL(ifla_policy);
1426