xref: /openbmc/linux/net/core/rtnetlink.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
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 
39 #include <asm/uaccess.h>
40 #include <asm/system.h>
41 #include <asm/string.h>
42 
43 #include <linux/inet.h>
44 #include <linux/netdevice.h>
45 #include <net/ip.h>
46 #include <net/protocol.h>
47 #include <net/arp.h>
48 #include <net/route.h>
49 #include <net/udp.h>
50 #include <net/sock.h>
51 #include <net/pkt_sched.h>
52 #include <net/fib_rules.h>
53 #include <net/rtnetlink.h>
54 
55 struct rtnl_link
56 {
57 	rtnl_doit_func		doit;
58 	rtnl_dumpit_func	dumpit;
59 };
60 
61 static DEFINE_MUTEX(rtnl_mutex);
62 static struct sock *rtnl;
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 	if (rtnl && rtnl->sk_receive_queue.qlen)
78 		rtnl->sk_data_ready(rtnl, 0);
79 	netdev_run_todo();
80 }
81 
82 int rtnl_trylock(void)
83 {
84 	return mutex_trylock(&rtnl_mutex);
85 }
86 
87 int rtattr_parse(struct rtattr *tb[], int maxattr, struct rtattr *rta, int len)
88 {
89 	memset(tb, 0, sizeof(struct rtattr*)*maxattr);
90 
91 	while (RTA_OK(rta, len)) {
92 		unsigned flavor = rta->rta_type;
93 		if (flavor && flavor <= maxattr)
94 			tb[flavor-1] = rta;
95 		rta = RTA_NEXT(rta, len);
96 	}
97 	return 0;
98 }
99 
100 static struct rtnl_link *rtnl_msg_handlers[NPROTO];
101 
102 static inline int rtm_msgindex(int msgtype)
103 {
104 	int msgindex = msgtype - RTM_BASE;
105 
106 	/*
107 	 * msgindex < 0 implies someone tried to register a netlink
108 	 * control code. msgindex >= RTM_NR_MSGTYPES may indicate that
109 	 * the message type has not been added to linux/rtnetlink.h
110 	 */
111 	BUG_ON(msgindex < 0 || msgindex >= RTM_NR_MSGTYPES);
112 
113 	return msgindex;
114 }
115 
116 static rtnl_doit_func rtnl_get_doit(int protocol, int msgindex)
117 {
118 	struct rtnl_link *tab;
119 
120 	tab = rtnl_msg_handlers[protocol];
121 	if (tab == NULL || tab[msgindex].doit == NULL)
122 		tab = rtnl_msg_handlers[PF_UNSPEC];
123 
124 	return tab ? tab[msgindex].doit : NULL;
125 }
126 
127 static rtnl_dumpit_func rtnl_get_dumpit(int protocol, int msgindex)
128 {
129 	struct rtnl_link *tab;
130 
131 	tab = rtnl_msg_handlers[protocol];
132 	if (tab == NULL || tab[msgindex].dumpit == NULL)
133 		tab = rtnl_msg_handlers[PF_UNSPEC];
134 
135 	return tab ? tab[msgindex].dumpit : NULL;
136 }
137 
138 /**
139  * __rtnl_register - Register a rtnetlink message type
140  * @protocol: Protocol family or PF_UNSPEC
141  * @msgtype: rtnetlink message type
142  * @doit: Function pointer called for each request message
143  * @dumpit: Function pointer called for each dump request (NLM_F_DUMP) message
144  *
145  * Registers the specified function pointers (at least one of them has
146  * to be non-NULL) to be called whenever a request message for the
147  * specified protocol family and message type is received.
148  *
149  * The special protocol family PF_UNSPEC may be used to define fallback
150  * function pointers for the case when no entry for the specific protocol
151  * family exists.
152  *
153  * Returns 0 on success or a negative error code.
154  */
155 int __rtnl_register(int protocol, int msgtype,
156 		    rtnl_doit_func doit, rtnl_dumpit_func dumpit)
157 {
158 	struct rtnl_link *tab;
159 	int msgindex;
160 
161 	BUG_ON(protocol < 0 || protocol >= NPROTO);
162 	msgindex = rtm_msgindex(msgtype);
163 
164 	tab = rtnl_msg_handlers[protocol];
165 	if (tab == NULL) {
166 		tab = kcalloc(RTM_NR_MSGTYPES, sizeof(*tab), GFP_KERNEL);
167 		if (tab == NULL)
168 			return -ENOBUFS;
169 
170 		rtnl_msg_handlers[protocol] = tab;
171 	}
172 
173 	if (doit)
174 		tab[msgindex].doit = doit;
175 
176 	if (dumpit)
177 		tab[msgindex].dumpit = dumpit;
178 
179 	return 0;
180 }
181 
182 EXPORT_SYMBOL_GPL(__rtnl_register);
183 
184 /**
185  * rtnl_register - Register a rtnetlink message type
186  *
187  * Identical to __rtnl_register() but panics on failure. This is useful
188  * as failure of this function is very unlikely, it can only happen due
189  * to lack of memory when allocating the chain to store all message
190  * handlers for a protocol. Meant for use in init functions where lack
191  * of memory implies no sense in continueing.
192  */
193 void rtnl_register(int protocol, int msgtype,
194 		   rtnl_doit_func doit, rtnl_dumpit_func dumpit)
195 {
196 	if (__rtnl_register(protocol, msgtype, doit, dumpit) < 0)
197 		panic("Unable to register rtnetlink message handler, "
198 		      "protocol = %d, message type = %d\n",
199 		      protocol, msgtype);
200 }
201 
202 EXPORT_SYMBOL_GPL(rtnl_register);
203 
204 /**
205  * rtnl_unregister - Unregister a rtnetlink message type
206  * @protocol: Protocol family or PF_UNSPEC
207  * @msgtype: rtnetlink message type
208  *
209  * Returns 0 on success or a negative error code.
210  */
211 int rtnl_unregister(int protocol, int msgtype)
212 {
213 	int msgindex;
214 
215 	BUG_ON(protocol < 0 || protocol >= NPROTO);
216 	msgindex = rtm_msgindex(msgtype);
217 
218 	if (rtnl_msg_handlers[protocol] == NULL)
219 		return -ENOENT;
220 
221 	rtnl_msg_handlers[protocol][msgindex].doit = NULL;
222 	rtnl_msg_handlers[protocol][msgindex].dumpit = NULL;
223 
224 	return 0;
225 }
226 
227 EXPORT_SYMBOL_GPL(rtnl_unregister);
228 
229 /**
230  * rtnl_unregister_all - Unregister all rtnetlink message type of a protocol
231  * @protocol : Protocol family or PF_UNSPEC
232  *
233  * Identical to calling rtnl_unregster() for all registered message types
234  * of a certain protocol family.
235  */
236 void rtnl_unregister_all(int protocol)
237 {
238 	BUG_ON(protocol < 0 || protocol >= NPROTO);
239 
240 	kfree(rtnl_msg_handlers[protocol]);
241 	rtnl_msg_handlers[protocol] = NULL;
242 }
243 
244 EXPORT_SYMBOL_GPL(rtnl_unregister_all);
245 
246 static const int rtm_min[RTM_NR_FAMILIES] =
247 {
248 	[RTM_FAM(RTM_NEWLINK)]      = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
249 	[RTM_FAM(RTM_NEWADDR)]      = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
250 	[RTM_FAM(RTM_NEWROUTE)]     = NLMSG_LENGTH(sizeof(struct rtmsg)),
251 	[RTM_FAM(RTM_NEWRULE)]      = NLMSG_LENGTH(sizeof(struct fib_rule_hdr)),
252 	[RTM_FAM(RTM_NEWQDISC)]     = NLMSG_LENGTH(sizeof(struct tcmsg)),
253 	[RTM_FAM(RTM_NEWTCLASS)]    = NLMSG_LENGTH(sizeof(struct tcmsg)),
254 	[RTM_FAM(RTM_NEWTFILTER)]   = NLMSG_LENGTH(sizeof(struct tcmsg)),
255 	[RTM_FAM(RTM_NEWACTION)]    = NLMSG_LENGTH(sizeof(struct tcamsg)),
256 	[RTM_FAM(RTM_GETMULTICAST)] = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
257 	[RTM_FAM(RTM_GETANYCAST)]   = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
258 };
259 
260 static const int rta_max[RTM_NR_FAMILIES] =
261 {
262 	[RTM_FAM(RTM_NEWLINK)]      = IFLA_MAX,
263 	[RTM_FAM(RTM_NEWADDR)]      = IFA_MAX,
264 	[RTM_FAM(RTM_NEWROUTE)]     = RTA_MAX,
265 	[RTM_FAM(RTM_NEWRULE)]      = FRA_MAX,
266 	[RTM_FAM(RTM_NEWQDISC)]     = TCA_MAX,
267 	[RTM_FAM(RTM_NEWTCLASS)]    = TCA_MAX,
268 	[RTM_FAM(RTM_NEWTFILTER)]   = TCA_MAX,
269 	[RTM_FAM(RTM_NEWACTION)]    = TCAA_MAX,
270 };
271 
272 void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
273 {
274 	struct rtattr *rta;
275 	int size = RTA_LENGTH(attrlen);
276 
277 	rta = (struct rtattr*)skb_put(skb, RTA_ALIGN(size));
278 	rta->rta_type = attrtype;
279 	rta->rta_len = size;
280 	memcpy(RTA_DATA(rta), data, attrlen);
281 	memset(RTA_DATA(rta) + attrlen, 0, RTA_ALIGN(size) - size);
282 }
283 
284 size_t rtattr_strlcpy(char *dest, const struct rtattr *rta, size_t size)
285 {
286 	size_t ret = RTA_PAYLOAD(rta);
287 	char *src = RTA_DATA(rta);
288 
289 	if (ret > 0 && src[ret - 1] == '\0')
290 		ret--;
291 	if (size > 0) {
292 		size_t len = (ret >= size) ? size - 1 : ret;
293 		memset(dest, 0, size);
294 		memcpy(dest, src, len);
295 	}
296 	return ret;
297 }
298 
299 int rtnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo)
300 {
301 	int err = 0;
302 
303 	NETLINK_CB(skb).dst_group = group;
304 	if (echo)
305 		atomic_inc(&skb->users);
306 	netlink_broadcast(rtnl, skb, pid, group, GFP_KERNEL);
307 	if (echo)
308 		err = netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
309 	return err;
310 }
311 
312 int rtnl_unicast(struct sk_buff *skb, u32 pid)
313 {
314 	return nlmsg_unicast(rtnl, skb, pid);
315 }
316 
317 int rtnl_notify(struct sk_buff *skb, u32 pid, u32 group,
318 		struct nlmsghdr *nlh, gfp_t flags)
319 {
320 	int report = 0;
321 
322 	if (nlh)
323 		report = nlmsg_report(nlh);
324 
325 	return nlmsg_notify(rtnl, skb, pid, group, report, flags);
326 }
327 
328 void rtnl_set_sk_err(u32 group, int error)
329 {
330 	netlink_set_err(rtnl, 0, group, error);
331 }
332 
333 int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics)
334 {
335 	struct nlattr *mx;
336 	int i, valid = 0;
337 
338 	mx = nla_nest_start(skb, RTA_METRICS);
339 	if (mx == NULL)
340 		return -ENOBUFS;
341 
342 	for (i = 0; i < RTAX_MAX; i++) {
343 		if (metrics[i]) {
344 			valid++;
345 			NLA_PUT_U32(skb, i+1, metrics[i]);
346 		}
347 	}
348 
349 	if (!valid) {
350 		nla_nest_cancel(skb, mx);
351 		return 0;
352 	}
353 
354 	return nla_nest_end(skb, mx);
355 
356 nla_put_failure:
357 	return nla_nest_cancel(skb, mx);
358 }
359 
360 int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id,
361 		       u32 ts, u32 tsage, long expires, u32 error)
362 {
363 	struct rta_cacheinfo ci = {
364 		.rta_lastuse = jiffies_to_clock_t(jiffies - dst->lastuse),
365 		.rta_used = dst->__use,
366 		.rta_clntref = atomic_read(&(dst->__refcnt)),
367 		.rta_error = error,
368 		.rta_id =  id,
369 		.rta_ts = ts,
370 		.rta_tsage = tsage,
371 	};
372 
373 	if (expires)
374 		ci.rta_expires = jiffies_to_clock_t(expires);
375 
376 	return nla_put(skb, RTA_CACHEINFO, sizeof(ci), &ci);
377 }
378 
379 EXPORT_SYMBOL_GPL(rtnl_put_cacheinfo);
380 
381 static void set_operstate(struct net_device *dev, unsigned char transition)
382 {
383 	unsigned char operstate = dev->operstate;
384 
385 	switch(transition) {
386 	case IF_OPER_UP:
387 		if ((operstate == IF_OPER_DORMANT ||
388 		     operstate == IF_OPER_UNKNOWN) &&
389 		    !netif_dormant(dev))
390 			operstate = IF_OPER_UP;
391 		break;
392 
393 	case IF_OPER_DORMANT:
394 		if (operstate == IF_OPER_UP ||
395 		    operstate == IF_OPER_UNKNOWN)
396 			operstate = IF_OPER_DORMANT;
397 		break;
398 	}
399 
400 	if (dev->operstate != operstate) {
401 		write_lock_bh(&dev_base_lock);
402 		dev->operstate = operstate;
403 		write_unlock_bh(&dev_base_lock);
404 		netdev_state_change(dev);
405 	}
406 }
407 
408 static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
409 				 struct net_device_stats *b)
410 {
411 	a->rx_packets = b->rx_packets;
412 	a->tx_packets = b->tx_packets;
413 	a->rx_bytes = b->rx_bytes;
414 	a->tx_bytes = b->tx_bytes;
415 	a->rx_errors = b->rx_errors;
416 	a->tx_errors = b->tx_errors;
417 	a->rx_dropped = b->rx_dropped;
418 	a->tx_dropped = b->tx_dropped;
419 
420 	a->multicast = b->multicast;
421 	a->collisions = b->collisions;
422 
423 	a->rx_length_errors = b->rx_length_errors;
424 	a->rx_over_errors = b->rx_over_errors;
425 	a->rx_crc_errors = b->rx_crc_errors;
426 	a->rx_frame_errors = b->rx_frame_errors;
427 	a->rx_fifo_errors = b->rx_fifo_errors;
428 	a->rx_missed_errors = b->rx_missed_errors;
429 
430 	a->tx_aborted_errors = b->tx_aborted_errors;
431 	a->tx_carrier_errors = b->tx_carrier_errors;
432 	a->tx_fifo_errors = b->tx_fifo_errors;
433 	a->tx_heartbeat_errors = b->tx_heartbeat_errors;
434 	a->tx_window_errors = b->tx_window_errors;
435 
436 	a->rx_compressed = b->rx_compressed;
437 	a->tx_compressed = b->tx_compressed;
438 };
439 
440 static inline size_t if_nlmsg_size(int iwbuflen)
441 {
442 	return NLMSG_ALIGN(sizeof(struct ifinfomsg))
443 	       + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
444 	       + nla_total_size(IFNAMSIZ) /* IFLA_QDISC */
445 	       + nla_total_size(sizeof(struct rtnl_link_ifmap))
446 	       + nla_total_size(sizeof(struct rtnl_link_stats))
447 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
448 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_BROADCAST */
449 	       + nla_total_size(4) /* IFLA_TXQLEN */
450 	       + nla_total_size(4) /* IFLA_WEIGHT */
451 	       + nla_total_size(4) /* IFLA_MTU */
452 	       + nla_total_size(4) /* IFLA_LINK */
453 	       + nla_total_size(4) /* IFLA_MASTER */
454 	       + nla_total_size(1) /* IFLA_OPERSTATE */
455 	       + nla_total_size(1) /* IFLA_LINKMODE */
456 	       + nla_total_size(iwbuflen);
457 }
458 
459 static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
460 			    void *iwbuf, int iwbuflen, int type, u32 pid,
461 			    u32 seq, u32 change, unsigned int flags)
462 {
463 	struct ifinfomsg *ifm;
464 	struct nlmsghdr *nlh;
465 
466 	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ifm), flags);
467 	if (nlh == NULL)
468 		return -EMSGSIZE;
469 
470 	ifm = nlmsg_data(nlh);
471 	ifm->ifi_family = AF_UNSPEC;
472 	ifm->__ifi_pad = 0;
473 	ifm->ifi_type = dev->type;
474 	ifm->ifi_index = dev->ifindex;
475 	ifm->ifi_flags = dev_get_flags(dev);
476 	ifm->ifi_change = change;
477 
478 	NLA_PUT_STRING(skb, IFLA_IFNAME, dev->name);
479 	NLA_PUT_U32(skb, IFLA_TXQLEN, dev->tx_queue_len);
480 	NLA_PUT_U32(skb, IFLA_WEIGHT, dev->weight);
481 	NLA_PUT_U8(skb, IFLA_OPERSTATE,
482 		   netif_running(dev) ? dev->operstate : IF_OPER_DOWN);
483 	NLA_PUT_U8(skb, IFLA_LINKMODE, dev->link_mode);
484 	NLA_PUT_U32(skb, IFLA_MTU, dev->mtu);
485 
486 	if (dev->ifindex != dev->iflink)
487 		NLA_PUT_U32(skb, IFLA_LINK, dev->iflink);
488 
489 	if (dev->master)
490 		NLA_PUT_U32(skb, IFLA_MASTER, dev->master->ifindex);
491 
492 	if (dev->qdisc_sleeping)
493 		NLA_PUT_STRING(skb, IFLA_QDISC, dev->qdisc_sleeping->ops->id);
494 
495 	if (1) {
496 		struct rtnl_link_ifmap map = {
497 			.mem_start   = dev->mem_start,
498 			.mem_end     = dev->mem_end,
499 			.base_addr   = dev->base_addr,
500 			.irq         = dev->irq,
501 			.dma         = dev->dma,
502 			.port        = dev->if_port,
503 		};
504 		NLA_PUT(skb, IFLA_MAP, sizeof(map), &map);
505 	}
506 
507 	if (dev->addr_len) {
508 		NLA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr);
509 		NLA_PUT(skb, IFLA_BROADCAST, dev->addr_len, dev->broadcast);
510 	}
511 
512 	if (dev->get_stats) {
513 		struct net_device_stats *stats = dev->get_stats(dev);
514 		if (stats) {
515 			struct nlattr *attr;
516 
517 			attr = nla_reserve(skb, IFLA_STATS,
518 					   sizeof(struct rtnl_link_stats));
519 			if (attr == NULL)
520 				goto nla_put_failure;
521 
522 			copy_rtnl_link_stats(nla_data(attr), stats);
523 		}
524 	}
525 
526 	if (iwbuf)
527 		NLA_PUT(skb, IFLA_WIRELESS, iwbuflen, iwbuf);
528 
529 	return nlmsg_end(skb, nlh);
530 
531 nla_put_failure:
532 	nlmsg_cancel(skb, nlh);
533 	return -EMSGSIZE;
534 }
535 
536 static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
537 {
538 	int idx;
539 	int s_idx = cb->args[0];
540 	struct net_device *dev;
541 
542 	idx = 0;
543 	for_each_netdev(dev) {
544 		if (idx < s_idx)
545 			goto cont;
546 		if (rtnl_fill_ifinfo(skb, dev, NULL, 0, RTM_NEWLINK,
547 				     NETLINK_CB(cb->skb).pid,
548 				     cb->nlh->nlmsg_seq, 0, NLM_F_MULTI) <= 0)
549 			break;
550 cont:
551 		idx++;
552 	}
553 	cb->args[0] = idx;
554 
555 	return skb->len;
556 }
557 
558 static struct nla_policy ifla_policy[IFLA_MAX+1] __read_mostly = {
559 	[IFLA_IFNAME]		= { .type = NLA_STRING, .len = IFNAMSIZ-1 },
560 	[IFLA_MAP]		= { .len = sizeof(struct rtnl_link_ifmap) },
561 	[IFLA_MTU]		= { .type = NLA_U32 },
562 	[IFLA_TXQLEN]		= { .type = NLA_U32 },
563 	[IFLA_WEIGHT]		= { .type = NLA_U32 },
564 	[IFLA_OPERSTATE]	= { .type = NLA_U8 },
565 	[IFLA_LINKMODE]		= { .type = NLA_U8 },
566 };
567 
568 static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
569 {
570 	struct ifinfomsg *ifm;
571 	struct net_device *dev;
572 	int err, send_addr_notify = 0, modified = 0;
573 	struct nlattr *tb[IFLA_MAX+1];
574 	char ifname[IFNAMSIZ];
575 
576 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
577 	if (err < 0)
578 		goto errout;
579 
580 	if (tb[IFLA_IFNAME])
581 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
582 	else
583 		ifname[0] = '\0';
584 
585 	err = -EINVAL;
586 	ifm = nlmsg_data(nlh);
587 	if (ifm->ifi_index >= 0)
588 		dev = dev_get_by_index(ifm->ifi_index);
589 	else if (tb[IFLA_IFNAME])
590 		dev = dev_get_by_name(ifname);
591 	else
592 		goto errout;
593 
594 	if (dev == NULL) {
595 		err = -ENODEV;
596 		goto errout;
597 	}
598 
599 	if (tb[IFLA_ADDRESS] &&
600 	    nla_len(tb[IFLA_ADDRESS]) < dev->addr_len)
601 		goto errout_dev;
602 
603 	if (tb[IFLA_BROADCAST] &&
604 	    nla_len(tb[IFLA_BROADCAST]) < dev->addr_len)
605 		goto errout_dev;
606 
607 	if (tb[IFLA_MAP]) {
608 		struct rtnl_link_ifmap *u_map;
609 		struct ifmap k_map;
610 
611 		if (!dev->set_config) {
612 			err = -EOPNOTSUPP;
613 			goto errout_dev;
614 		}
615 
616 		if (!netif_device_present(dev)) {
617 			err = -ENODEV;
618 			goto errout_dev;
619 		}
620 
621 		u_map = nla_data(tb[IFLA_MAP]);
622 		k_map.mem_start = (unsigned long) u_map->mem_start;
623 		k_map.mem_end = (unsigned long) u_map->mem_end;
624 		k_map.base_addr = (unsigned short) u_map->base_addr;
625 		k_map.irq = (unsigned char) u_map->irq;
626 		k_map.dma = (unsigned char) u_map->dma;
627 		k_map.port = (unsigned char) u_map->port;
628 
629 		err = dev->set_config(dev, &k_map);
630 		if (err < 0)
631 			goto errout_dev;
632 
633 		modified = 1;
634 	}
635 
636 	if (tb[IFLA_ADDRESS]) {
637 		struct sockaddr *sa;
638 		int len;
639 
640 		if (!dev->set_mac_address) {
641 			err = -EOPNOTSUPP;
642 			goto errout_dev;
643 		}
644 
645 		if (!netif_device_present(dev)) {
646 			err = -ENODEV;
647 			goto errout_dev;
648 		}
649 
650 		len = sizeof(sa_family_t) + dev->addr_len;
651 		sa = kmalloc(len, GFP_KERNEL);
652 		if (!sa) {
653 			err = -ENOMEM;
654 			goto errout_dev;
655 		}
656 		sa->sa_family = dev->type;
657 		memcpy(sa->sa_data, nla_data(tb[IFLA_ADDRESS]),
658 		       dev->addr_len);
659 		err = dev->set_mac_address(dev, sa);
660 		kfree(sa);
661 		if (err)
662 			goto errout_dev;
663 		send_addr_notify = 1;
664 		modified = 1;
665 	}
666 
667 	if (tb[IFLA_MTU]) {
668 		err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
669 		if (err < 0)
670 			goto errout_dev;
671 		modified = 1;
672 	}
673 
674 	/*
675 	 * Interface selected by interface index but interface
676 	 * name provided implies that a name change has been
677 	 * requested.
678 	 */
679 	if (ifm->ifi_index >= 0 && ifname[0]) {
680 		err = dev_change_name(dev, ifname);
681 		if (err < 0)
682 			goto errout_dev;
683 		modified = 1;
684 	}
685 
686 	if (tb[IFLA_BROADCAST]) {
687 		nla_memcpy(dev->broadcast, tb[IFLA_BROADCAST], dev->addr_len);
688 		send_addr_notify = 1;
689 	}
690 
691 
692 	if (ifm->ifi_flags)
693 		dev_change_flags(dev, ifm->ifi_flags);
694 
695 	if (tb[IFLA_TXQLEN])
696 		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
697 
698 	if (tb[IFLA_WEIGHT])
699 		dev->weight = nla_get_u32(tb[IFLA_WEIGHT]);
700 
701 	if (tb[IFLA_OPERSTATE])
702 		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
703 
704 	if (tb[IFLA_LINKMODE]) {
705 		write_lock_bh(&dev_base_lock);
706 		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
707 		write_unlock_bh(&dev_base_lock);
708 	}
709 
710 	err = 0;
711 
712 errout_dev:
713 	if (err < 0 && modified && net_ratelimit())
714 		printk(KERN_WARNING "A link change request failed with "
715 		       "some changes comitted already. Interface %s may "
716 		       "have been left with an inconsistent configuration, "
717 		       "please check.\n", dev->name);
718 
719 	if (send_addr_notify)
720 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
721 
722 	dev_put(dev);
723 errout:
724 	return err;
725 }
726 
727 static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
728 {
729 	struct ifinfomsg *ifm;
730 	struct nlattr *tb[IFLA_MAX+1];
731 	struct net_device *dev = NULL;
732 	struct sk_buff *nskb;
733 	char *iw_buf = NULL, *iw = NULL;
734 	int iw_buf_len = 0;
735 	int err;
736 
737 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
738 	if (err < 0)
739 		return err;
740 
741 	ifm = nlmsg_data(nlh);
742 	if (ifm->ifi_index >= 0) {
743 		dev = dev_get_by_index(ifm->ifi_index);
744 		if (dev == NULL)
745 			return -ENODEV;
746 	} else
747 		return -EINVAL;
748 
749 	nskb = nlmsg_new(if_nlmsg_size(iw_buf_len), GFP_KERNEL);
750 	if (nskb == NULL) {
751 		err = -ENOBUFS;
752 		goto errout;
753 	}
754 
755 	err = rtnl_fill_ifinfo(nskb, dev, iw, iw_buf_len, RTM_NEWLINK,
756 			       NETLINK_CB(skb).pid, nlh->nlmsg_seq, 0, 0);
757 	if (err < 0) {
758 		/* -EMSGSIZE implies BUG in if_nlmsg_size */
759 		WARN_ON(err == -EMSGSIZE);
760 		kfree_skb(nskb);
761 		goto errout;
762 	}
763 	err = rtnl_unicast(nskb, NETLINK_CB(skb).pid);
764 errout:
765 	kfree(iw_buf);
766 	dev_put(dev);
767 
768 	return err;
769 }
770 
771 static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
772 {
773 	int idx;
774 	int s_idx = cb->family;
775 
776 	if (s_idx == 0)
777 		s_idx = 1;
778 	for (idx=1; idx<NPROTO; idx++) {
779 		int type = cb->nlh->nlmsg_type-RTM_BASE;
780 		if (idx < s_idx || idx == PF_PACKET)
781 			continue;
782 		if (rtnl_msg_handlers[idx] == NULL ||
783 		    rtnl_msg_handlers[idx][type].dumpit == NULL)
784 			continue;
785 		if (idx > s_idx)
786 			memset(&cb->args[0], 0, sizeof(cb->args));
787 		if (rtnl_msg_handlers[idx][type].dumpit(skb, cb))
788 			break;
789 	}
790 	cb->family = idx;
791 
792 	return skb->len;
793 }
794 
795 void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change)
796 {
797 	struct sk_buff *skb;
798 	int err = -ENOBUFS;
799 
800 	skb = nlmsg_new(if_nlmsg_size(0), GFP_KERNEL);
801 	if (skb == NULL)
802 		goto errout;
803 
804 	err = rtnl_fill_ifinfo(skb, dev, NULL, 0, type, 0, 0, change, 0);
805 	if (err < 0) {
806 		/* -EMSGSIZE implies BUG in if_nlmsg_size() */
807 		WARN_ON(err == -EMSGSIZE);
808 		kfree_skb(skb);
809 		goto errout;
810 	}
811 	err = rtnl_notify(skb, 0, RTNLGRP_LINK, NULL, GFP_KERNEL);
812 errout:
813 	if (err < 0)
814 		rtnl_set_sk_err(RTNLGRP_LINK, err);
815 }
816 
817 /* Protected by RTNL sempahore.  */
818 static struct rtattr **rta_buf;
819 static int rtattr_max;
820 
821 /* Process one rtnetlink message. */
822 
823 static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
824 {
825 	rtnl_doit_func doit;
826 	int sz_idx, kind;
827 	int min_len;
828 	int family;
829 	int type;
830 	int err;
831 
832 	type = nlh->nlmsg_type;
833 	if (type > RTM_MAX)
834 		return -EOPNOTSUPP;
835 
836 	type -= RTM_BASE;
837 
838 	/* All the messages must have at least 1 byte length */
839 	if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct rtgenmsg)))
840 		return 0;
841 
842 	family = ((struct rtgenmsg*)NLMSG_DATA(nlh))->rtgen_family;
843 	if (family >= NPROTO)
844 		return -EAFNOSUPPORT;
845 
846 	sz_idx = type>>2;
847 	kind = type&3;
848 
849 	if (kind != 2 && security_netlink_recv(skb, CAP_NET_ADMIN))
850 		return -EPERM;
851 
852 	if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
853 		rtnl_dumpit_func dumpit;
854 
855 		dumpit = rtnl_get_dumpit(family, type);
856 		if (dumpit == NULL)
857 			return -EOPNOTSUPP;
858 
859 		__rtnl_unlock();
860 		err = netlink_dump_start(rtnl, skb, nlh, dumpit, NULL);
861 		rtnl_lock();
862 		return err;
863 	}
864 
865 	memset(rta_buf, 0, (rtattr_max * sizeof(struct rtattr *)));
866 
867 	min_len = rtm_min[sz_idx];
868 	if (nlh->nlmsg_len < min_len)
869 		return -EINVAL;
870 
871 	if (nlh->nlmsg_len > min_len) {
872 		int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
873 		struct rtattr *attr = (void*)nlh + NLMSG_ALIGN(min_len);
874 
875 		while (RTA_OK(attr, attrlen)) {
876 			unsigned flavor = attr->rta_type;
877 			if (flavor) {
878 				if (flavor > rta_max[sz_idx])
879 					return -EINVAL;
880 				rta_buf[flavor-1] = attr;
881 			}
882 			attr = RTA_NEXT(attr, attrlen);
883 		}
884 	}
885 
886 	doit = rtnl_get_doit(family, type);
887 	if (doit == NULL)
888 		return -EOPNOTSUPP;
889 
890 	return doit(skb, nlh, (void *)&rta_buf[0]);
891 }
892 
893 static void rtnetlink_rcv(struct sock *sk, int len)
894 {
895 	unsigned int qlen = 0;
896 
897 	do {
898 		mutex_lock(&rtnl_mutex);
899 		netlink_run_queue(sk, &qlen, &rtnetlink_rcv_msg);
900 		mutex_unlock(&rtnl_mutex);
901 
902 		netdev_run_todo();
903 	} while (qlen);
904 }
905 
906 static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr)
907 {
908 	struct net_device *dev = ptr;
909 	switch (event) {
910 	case NETDEV_UNREGISTER:
911 		rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
912 		break;
913 	case NETDEV_REGISTER:
914 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
915 		break;
916 	case NETDEV_UP:
917 	case NETDEV_DOWN:
918 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
919 		break;
920 	case NETDEV_CHANGE:
921 	case NETDEV_GOING_DOWN:
922 		break;
923 	default:
924 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
925 		break;
926 	}
927 	return NOTIFY_DONE;
928 }
929 
930 static struct notifier_block rtnetlink_dev_notifier = {
931 	.notifier_call	= rtnetlink_event,
932 };
933 
934 void __init rtnetlink_init(void)
935 {
936 	int i;
937 
938 	rtattr_max = 0;
939 	for (i = 0; i < ARRAY_SIZE(rta_max); i++)
940 		if (rta_max[i] > rtattr_max)
941 			rtattr_max = rta_max[i];
942 	rta_buf = kmalloc(rtattr_max * sizeof(struct rtattr *), GFP_KERNEL);
943 	if (!rta_buf)
944 		panic("rtnetlink_init: cannot allocate rta_buf\n");
945 
946 	rtnl = netlink_kernel_create(NETLINK_ROUTE, RTNLGRP_MAX, rtnetlink_rcv,
947 				     &rtnl_mutex, THIS_MODULE);
948 	if (rtnl == NULL)
949 		panic("rtnetlink_init: cannot initialize rtnetlink\n");
950 	netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
951 	register_netdevice_notifier(&rtnetlink_dev_notifier);
952 
953 	rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink, rtnl_dump_ifinfo);
954 	rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL);
955 
956 	rtnl_register(PF_UNSPEC, RTM_GETADDR, NULL, rtnl_dump_all);
957 	rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all);
958 }
959 
960 EXPORT_SYMBOL(__rta_fill);
961 EXPORT_SYMBOL(rtattr_strlcpy);
962 EXPORT_SYMBOL(rtattr_parse);
963 EXPORT_SYMBOL(rtnetlink_put_metrics);
964 EXPORT_SYMBOL(rtnl_lock);
965 EXPORT_SYMBOL(rtnl_trylock);
966 EXPORT_SYMBOL(rtnl_unlock);
967 EXPORT_SYMBOL(rtnl_unicast);
968 EXPORT_SYMBOL(rtnl_notify);
969 EXPORT_SYMBOL(rtnl_set_sk_err);
970