xref: /openbmc/linux/net/ipv4/fib_frontend.c (revision ae3473231e77a3f1909d48cd144cebe5e1d049b3)
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  *		IPv4 Forwarding Information Base: FIB frontend.
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 
16 #include <linux/module.h>
17 #include <linux/uaccess.h>
18 #include <linux/bitops.h>
19 #include <linux/capability.h>
20 #include <linux/types.h>
21 #include <linux/kernel.h>
22 #include <linux/mm.h>
23 #include <linux/string.h>
24 #include <linux/socket.h>
25 #include <linux/sockios.h>
26 #include <linux/errno.h>
27 #include <linux/in.h>
28 #include <linux/inet.h>
29 #include <linux/inetdevice.h>
30 #include <linux/netdevice.h>
31 #include <linux/if_addr.h>
32 #include <linux/if_arp.h>
33 #include <linux/skbuff.h>
34 #include <linux/cache.h>
35 #include <linux/init.h>
36 #include <linux/list.h>
37 #include <linux/slab.h>
38 
39 #include <net/ip.h>
40 #include <net/protocol.h>
41 #include <net/route.h>
42 #include <net/tcp.h>
43 #include <net/sock.h>
44 #include <net/arp.h>
45 #include <net/ip_fib.h>
46 #include <net/rtnetlink.h>
47 #include <net/xfrm.h>
48 #include <net/l3mdev.h>
49 #include <trace/events/fib.h>
50 
51 #ifndef CONFIG_IP_MULTIPLE_TABLES
52 
53 static int __net_init fib4_rules_init(struct net *net)
54 {
55 	struct fib_table *local_table, *main_table;
56 
57 	main_table  = fib_trie_table(RT_TABLE_MAIN, NULL);
58 	if (!main_table)
59 		return -ENOMEM;
60 
61 	local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
62 	if (!local_table)
63 		goto fail;
64 
65 	hlist_add_head_rcu(&local_table->tb_hlist,
66 				&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
67 	hlist_add_head_rcu(&main_table->tb_hlist,
68 				&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
69 	return 0;
70 
71 fail:
72 	fib_free_table(main_table);
73 	return -ENOMEM;
74 }
75 #else
76 
77 struct fib_table *fib_new_table(struct net *net, u32 id)
78 {
79 	struct fib_table *tb, *alias = NULL;
80 	unsigned int h;
81 
82 	if (id == 0)
83 		id = RT_TABLE_MAIN;
84 	tb = fib_get_table(net, id);
85 	if (tb)
86 		return tb;
87 
88 	if (id == RT_TABLE_LOCAL)
89 		alias = fib_new_table(net, RT_TABLE_MAIN);
90 
91 	tb = fib_trie_table(id, alias);
92 	if (!tb)
93 		return NULL;
94 
95 	switch (id) {
96 	case RT_TABLE_MAIN:
97 		rcu_assign_pointer(net->ipv4.fib_main, tb);
98 		break;
99 	case RT_TABLE_DEFAULT:
100 		rcu_assign_pointer(net->ipv4.fib_default, tb);
101 		break;
102 	default:
103 		break;
104 	}
105 
106 	h = id & (FIB_TABLE_HASHSZ - 1);
107 	hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
108 	return tb;
109 }
110 EXPORT_SYMBOL_GPL(fib_new_table);
111 
112 /* caller must hold either rtnl or rcu read lock */
113 struct fib_table *fib_get_table(struct net *net, u32 id)
114 {
115 	struct fib_table *tb;
116 	struct hlist_head *head;
117 	unsigned int h;
118 
119 	if (id == 0)
120 		id = RT_TABLE_MAIN;
121 	h = id & (FIB_TABLE_HASHSZ - 1);
122 
123 	head = &net->ipv4.fib_table_hash[h];
124 	hlist_for_each_entry_rcu(tb, head, tb_hlist) {
125 		if (tb->tb_id == id)
126 			return tb;
127 	}
128 	return NULL;
129 }
130 #endif /* CONFIG_IP_MULTIPLE_TABLES */
131 
132 static void fib_replace_table(struct net *net, struct fib_table *old,
133 			      struct fib_table *new)
134 {
135 #ifdef CONFIG_IP_MULTIPLE_TABLES
136 	switch (new->tb_id) {
137 	case RT_TABLE_MAIN:
138 		rcu_assign_pointer(net->ipv4.fib_main, new);
139 		break;
140 	case RT_TABLE_DEFAULT:
141 		rcu_assign_pointer(net->ipv4.fib_default, new);
142 		break;
143 	default:
144 		break;
145 	}
146 
147 #endif
148 	/* replace the old table in the hlist */
149 	hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
150 }
151 
152 int fib_unmerge(struct net *net)
153 {
154 	struct fib_table *old, *new, *main_table;
155 
156 	/* attempt to fetch local table if it has been allocated */
157 	old = fib_get_table(net, RT_TABLE_LOCAL);
158 	if (!old)
159 		return 0;
160 
161 	new = fib_trie_unmerge(old);
162 	if (!new)
163 		return -ENOMEM;
164 
165 	/* table is already unmerged */
166 	if (new == old)
167 		return 0;
168 
169 	/* replace merged table with clean table */
170 	fib_replace_table(net, old, new);
171 	fib_free_table(old);
172 
173 	/* attempt to fetch main table if it has been allocated */
174 	main_table = fib_get_table(net, RT_TABLE_MAIN);
175 	if (!main_table)
176 		return 0;
177 
178 	/* flush local entries from main table */
179 	fib_table_flush_external(main_table);
180 
181 	return 0;
182 }
183 
184 static void fib_flush(struct net *net)
185 {
186 	int flushed = 0;
187 	unsigned int h;
188 
189 	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
190 		struct hlist_head *head = &net->ipv4.fib_table_hash[h];
191 		struct hlist_node *tmp;
192 		struct fib_table *tb;
193 
194 		hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
195 			flushed += fib_table_flush(net, tb);
196 	}
197 
198 	if (flushed)
199 		rt_cache_flush(net);
200 }
201 
202 /*
203  * Find address type as if only "dev" was present in the system. If
204  * on_dev is NULL then all interfaces are taken into consideration.
205  */
206 static inline unsigned int __inet_dev_addr_type(struct net *net,
207 						const struct net_device *dev,
208 						__be32 addr, u32 tb_id)
209 {
210 	struct flowi4		fl4 = { .daddr = addr };
211 	struct fib_result	res;
212 	unsigned int ret = RTN_BROADCAST;
213 	struct fib_table *table;
214 
215 	if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
216 		return RTN_BROADCAST;
217 	if (ipv4_is_multicast(addr))
218 		return RTN_MULTICAST;
219 
220 	rcu_read_lock();
221 
222 	table = fib_get_table(net, tb_id);
223 	if (table) {
224 		ret = RTN_UNICAST;
225 		if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
226 			if (!dev || dev == res.fi->fib_dev)
227 				ret = res.type;
228 		}
229 	}
230 
231 	rcu_read_unlock();
232 	return ret;
233 }
234 
235 unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
236 {
237 	return __inet_dev_addr_type(net, NULL, addr, tb_id);
238 }
239 EXPORT_SYMBOL(inet_addr_type_table);
240 
241 unsigned int inet_addr_type(struct net *net, __be32 addr)
242 {
243 	return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
244 }
245 EXPORT_SYMBOL(inet_addr_type);
246 
247 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
248 				__be32 addr)
249 {
250 	u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
251 
252 	return __inet_dev_addr_type(net, dev, addr, rt_table);
253 }
254 EXPORT_SYMBOL(inet_dev_addr_type);
255 
256 /* inet_addr_type with dev == NULL but using the table from a dev
257  * if one is associated
258  */
259 unsigned int inet_addr_type_dev_table(struct net *net,
260 				      const struct net_device *dev,
261 				      __be32 addr)
262 {
263 	u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
264 
265 	return __inet_dev_addr_type(net, NULL, addr, rt_table);
266 }
267 EXPORT_SYMBOL(inet_addr_type_dev_table);
268 
269 __be32 fib_compute_spec_dst(struct sk_buff *skb)
270 {
271 	struct net_device *dev = skb->dev;
272 	struct in_device *in_dev;
273 	struct fib_result res;
274 	struct rtable *rt;
275 	struct net *net;
276 	int scope;
277 
278 	rt = skb_rtable(skb);
279 	if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
280 	    RTCF_LOCAL)
281 		return ip_hdr(skb)->daddr;
282 
283 	in_dev = __in_dev_get_rcu(dev);
284 	BUG_ON(!in_dev);
285 
286 	net = dev_net(dev);
287 
288 	scope = RT_SCOPE_UNIVERSE;
289 	if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
290 		struct flowi4 fl4 = {
291 			.flowi4_iif = LOOPBACK_IFINDEX,
292 			.daddr = ip_hdr(skb)->saddr,
293 			.flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
294 			.flowi4_scope = scope,
295 			.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0,
296 		};
297 		if (!fib_lookup(net, &fl4, &res, 0))
298 			return FIB_RES_PREFSRC(net, res);
299 	} else {
300 		scope = RT_SCOPE_LINK;
301 	}
302 
303 	return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
304 }
305 
306 /* Given (packet source, input interface) and optional (dst, oif, tos):
307  * - (main) check, that source is valid i.e. not broadcast or our local
308  *   address.
309  * - figure out what "logical" interface this packet arrived
310  *   and calculate "specific destination" address.
311  * - check, that packet arrived from expected physical interface.
312  * called with rcu_read_lock()
313  */
314 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
315 				 u8 tos, int oif, struct net_device *dev,
316 				 int rpf, struct in_device *idev, u32 *itag)
317 {
318 	int ret, no_addr;
319 	struct fib_result res;
320 	struct flowi4 fl4;
321 	struct net *net;
322 	bool dev_match;
323 
324 	fl4.flowi4_oif = 0;
325 	fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
326 	if (!fl4.flowi4_iif)
327 		fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
328 	fl4.daddr = src;
329 	fl4.saddr = dst;
330 	fl4.flowi4_tos = tos;
331 	fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
332 	fl4.flowi4_tun_key.tun_id = 0;
333 	fl4.flowi4_flags = 0;
334 
335 	no_addr = idev->ifa_list == NULL;
336 
337 	fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
338 
339 	trace_fib_validate_source(dev, &fl4);
340 
341 	net = dev_net(dev);
342 	if (fib_lookup(net, &fl4, &res, 0))
343 		goto last_resort;
344 	if (res.type != RTN_UNICAST &&
345 	    (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
346 		goto e_inval;
347 	if (!rpf && !fib_num_tclassid_users(dev_net(dev)) &&
348 	    (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev)))
349 		goto last_resort;
350 	fib_combine_itag(itag, &res);
351 	dev_match = false;
352 
353 #ifdef CONFIG_IP_ROUTE_MULTIPATH
354 	for (ret = 0; ret < res.fi->fib_nhs; ret++) {
355 		struct fib_nh *nh = &res.fi->fib_nh[ret];
356 
357 		if (nh->nh_dev == dev) {
358 			dev_match = true;
359 			break;
360 		} else if (l3mdev_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
361 			dev_match = true;
362 			break;
363 		}
364 	}
365 #else
366 	if (FIB_RES_DEV(res) == dev)
367 		dev_match = true;
368 #endif
369 	if (dev_match) {
370 		ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
371 		return ret;
372 	}
373 	if (no_addr)
374 		goto last_resort;
375 	if (rpf == 1)
376 		goto e_rpf;
377 	fl4.flowi4_oif = dev->ifindex;
378 
379 	ret = 0;
380 	if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
381 		if (res.type == RTN_UNICAST)
382 			ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
383 	}
384 	return ret;
385 
386 last_resort:
387 	if (rpf)
388 		goto e_rpf;
389 	*itag = 0;
390 	return 0;
391 
392 e_inval:
393 	return -EINVAL;
394 e_rpf:
395 	return -EXDEV;
396 }
397 
398 /* Ignore rp_filter for packets protected by IPsec. */
399 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
400 			u8 tos, int oif, struct net_device *dev,
401 			struct in_device *idev, u32 *itag)
402 {
403 	int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
404 
405 	if (!r && !fib_num_tclassid_users(dev_net(dev)) &&
406 	    IN_DEV_ACCEPT_LOCAL(idev) &&
407 	    (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
408 		*itag = 0;
409 		return 0;
410 	}
411 	return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
412 }
413 
414 static inline __be32 sk_extract_addr(struct sockaddr *addr)
415 {
416 	return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
417 }
418 
419 static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
420 {
421 	struct nlattr *nla;
422 
423 	nla = (struct nlattr *) ((char *) mx + len);
424 	nla->nla_type = type;
425 	nla->nla_len = nla_attr_size(4);
426 	*(u32 *) nla_data(nla) = value;
427 
428 	return len + nla_total_size(4);
429 }
430 
431 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
432 				 struct fib_config *cfg)
433 {
434 	__be32 addr;
435 	int plen;
436 
437 	memset(cfg, 0, sizeof(*cfg));
438 	cfg->fc_nlinfo.nl_net = net;
439 
440 	if (rt->rt_dst.sa_family != AF_INET)
441 		return -EAFNOSUPPORT;
442 
443 	/*
444 	 * Check mask for validity:
445 	 * a) it must be contiguous.
446 	 * b) destination must have all host bits clear.
447 	 * c) if application forgot to set correct family (AF_INET),
448 	 *    reject request unless it is absolutely clear i.e.
449 	 *    both family and mask are zero.
450 	 */
451 	plen = 32;
452 	addr = sk_extract_addr(&rt->rt_dst);
453 	if (!(rt->rt_flags & RTF_HOST)) {
454 		__be32 mask = sk_extract_addr(&rt->rt_genmask);
455 
456 		if (rt->rt_genmask.sa_family != AF_INET) {
457 			if (mask || rt->rt_genmask.sa_family)
458 				return -EAFNOSUPPORT;
459 		}
460 
461 		if (bad_mask(mask, addr))
462 			return -EINVAL;
463 
464 		plen = inet_mask_len(mask);
465 	}
466 
467 	cfg->fc_dst_len = plen;
468 	cfg->fc_dst = addr;
469 
470 	if (cmd != SIOCDELRT) {
471 		cfg->fc_nlflags = NLM_F_CREATE;
472 		cfg->fc_protocol = RTPROT_BOOT;
473 	}
474 
475 	if (rt->rt_metric)
476 		cfg->fc_priority = rt->rt_metric - 1;
477 
478 	if (rt->rt_flags & RTF_REJECT) {
479 		cfg->fc_scope = RT_SCOPE_HOST;
480 		cfg->fc_type = RTN_UNREACHABLE;
481 		return 0;
482 	}
483 
484 	cfg->fc_scope = RT_SCOPE_NOWHERE;
485 	cfg->fc_type = RTN_UNICAST;
486 
487 	if (rt->rt_dev) {
488 		char *colon;
489 		struct net_device *dev;
490 		char devname[IFNAMSIZ];
491 
492 		if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
493 			return -EFAULT;
494 
495 		devname[IFNAMSIZ-1] = 0;
496 		colon = strchr(devname, ':');
497 		if (colon)
498 			*colon = 0;
499 		dev = __dev_get_by_name(net, devname);
500 		if (!dev)
501 			return -ENODEV;
502 		cfg->fc_oif = dev->ifindex;
503 		cfg->fc_table = l3mdev_fib_table(dev);
504 		if (colon) {
505 			struct in_ifaddr *ifa;
506 			struct in_device *in_dev = __in_dev_get_rtnl(dev);
507 			if (!in_dev)
508 				return -ENODEV;
509 			*colon = ':';
510 			for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
511 				if (strcmp(ifa->ifa_label, devname) == 0)
512 					break;
513 			if (!ifa)
514 				return -ENODEV;
515 			cfg->fc_prefsrc = ifa->ifa_local;
516 		}
517 	}
518 
519 	addr = sk_extract_addr(&rt->rt_gateway);
520 	if (rt->rt_gateway.sa_family == AF_INET && addr) {
521 		unsigned int addr_type;
522 
523 		cfg->fc_gw = addr;
524 		addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
525 		if (rt->rt_flags & RTF_GATEWAY &&
526 		    addr_type == RTN_UNICAST)
527 			cfg->fc_scope = RT_SCOPE_UNIVERSE;
528 	}
529 
530 	if (cmd == SIOCDELRT)
531 		return 0;
532 
533 	if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
534 		return -EINVAL;
535 
536 	if (cfg->fc_scope == RT_SCOPE_NOWHERE)
537 		cfg->fc_scope = RT_SCOPE_LINK;
538 
539 	if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
540 		struct nlattr *mx;
541 		int len = 0;
542 
543 		mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
544 		if (!mx)
545 			return -ENOMEM;
546 
547 		if (rt->rt_flags & RTF_MTU)
548 			len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
549 
550 		if (rt->rt_flags & RTF_WINDOW)
551 			len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
552 
553 		if (rt->rt_flags & RTF_IRTT)
554 			len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
555 
556 		cfg->fc_mx = mx;
557 		cfg->fc_mx_len = len;
558 	}
559 
560 	return 0;
561 }
562 
563 /*
564  * Handle IP routing ioctl calls.
565  * These are used to manipulate the routing tables
566  */
567 int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
568 {
569 	struct fib_config cfg;
570 	struct rtentry rt;
571 	int err;
572 
573 	switch (cmd) {
574 	case SIOCADDRT:		/* Add a route */
575 	case SIOCDELRT:		/* Delete a route */
576 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
577 			return -EPERM;
578 
579 		if (copy_from_user(&rt, arg, sizeof(rt)))
580 			return -EFAULT;
581 
582 		rtnl_lock();
583 		err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
584 		if (err == 0) {
585 			struct fib_table *tb;
586 
587 			if (cmd == SIOCDELRT) {
588 				tb = fib_get_table(net, cfg.fc_table);
589 				if (tb)
590 					err = fib_table_delete(net, tb, &cfg);
591 				else
592 					err = -ESRCH;
593 			} else {
594 				tb = fib_new_table(net, cfg.fc_table);
595 				if (tb)
596 					err = fib_table_insert(net, tb, &cfg);
597 				else
598 					err = -ENOBUFS;
599 			}
600 
601 			/* allocated by rtentry_to_fib_config() */
602 			kfree(cfg.fc_mx);
603 		}
604 		rtnl_unlock();
605 		return err;
606 	}
607 	return -EINVAL;
608 }
609 
610 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
611 	[RTA_DST]		= { .type = NLA_U32 },
612 	[RTA_SRC]		= { .type = NLA_U32 },
613 	[RTA_IIF]		= { .type = NLA_U32 },
614 	[RTA_OIF]		= { .type = NLA_U32 },
615 	[RTA_GATEWAY]		= { .type = NLA_U32 },
616 	[RTA_PRIORITY]		= { .type = NLA_U32 },
617 	[RTA_PREFSRC]		= { .type = NLA_U32 },
618 	[RTA_METRICS]		= { .type = NLA_NESTED },
619 	[RTA_MULTIPATH]		= { .len = sizeof(struct rtnexthop) },
620 	[RTA_FLOW]		= { .type = NLA_U32 },
621 	[RTA_ENCAP_TYPE]	= { .type = NLA_U16 },
622 	[RTA_ENCAP]		= { .type = NLA_NESTED },
623 	[RTA_UID]		= { .type = NLA_U32 },
624 };
625 
626 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
627 			     struct nlmsghdr *nlh, struct fib_config *cfg)
628 {
629 	struct nlattr *attr;
630 	int err, remaining;
631 	struct rtmsg *rtm;
632 
633 	err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
634 	if (err < 0)
635 		goto errout;
636 
637 	memset(cfg, 0, sizeof(*cfg));
638 
639 	rtm = nlmsg_data(nlh);
640 	cfg->fc_dst_len = rtm->rtm_dst_len;
641 	cfg->fc_tos = rtm->rtm_tos;
642 	cfg->fc_table = rtm->rtm_table;
643 	cfg->fc_protocol = rtm->rtm_protocol;
644 	cfg->fc_scope = rtm->rtm_scope;
645 	cfg->fc_type = rtm->rtm_type;
646 	cfg->fc_flags = rtm->rtm_flags;
647 	cfg->fc_nlflags = nlh->nlmsg_flags;
648 
649 	cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
650 	cfg->fc_nlinfo.nlh = nlh;
651 	cfg->fc_nlinfo.nl_net = net;
652 
653 	if (cfg->fc_type > RTN_MAX) {
654 		err = -EINVAL;
655 		goto errout;
656 	}
657 
658 	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
659 		switch (nla_type(attr)) {
660 		case RTA_DST:
661 			cfg->fc_dst = nla_get_be32(attr);
662 			break;
663 		case RTA_OIF:
664 			cfg->fc_oif = nla_get_u32(attr);
665 			break;
666 		case RTA_GATEWAY:
667 			cfg->fc_gw = nla_get_be32(attr);
668 			break;
669 		case RTA_PRIORITY:
670 			cfg->fc_priority = nla_get_u32(attr);
671 			break;
672 		case RTA_PREFSRC:
673 			cfg->fc_prefsrc = nla_get_be32(attr);
674 			break;
675 		case RTA_METRICS:
676 			cfg->fc_mx = nla_data(attr);
677 			cfg->fc_mx_len = nla_len(attr);
678 			break;
679 		case RTA_MULTIPATH:
680 			cfg->fc_mp = nla_data(attr);
681 			cfg->fc_mp_len = nla_len(attr);
682 			break;
683 		case RTA_FLOW:
684 			cfg->fc_flow = nla_get_u32(attr);
685 			break;
686 		case RTA_TABLE:
687 			cfg->fc_table = nla_get_u32(attr);
688 			break;
689 		case RTA_ENCAP:
690 			cfg->fc_encap = attr;
691 			break;
692 		case RTA_ENCAP_TYPE:
693 			cfg->fc_encap_type = nla_get_u16(attr);
694 			break;
695 		}
696 	}
697 
698 	return 0;
699 errout:
700 	return err;
701 }
702 
703 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
704 {
705 	struct net *net = sock_net(skb->sk);
706 	struct fib_config cfg;
707 	struct fib_table *tb;
708 	int err;
709 
710 	err = rtm_to_fib_config(net, skb, nlh, &cfg);
711 	if (err < 0)
712 		goto errout;
713 
714 	tb = fib_get_table(net, cfg.fc_table);
715 	if (!tb) {
716 		err = -ESRCH;
717 		goto errout;
718 	}
719 
720 	err = fib_table_delete(net, tb, &cfg);
721 errout:
722 	return err;
723 }
724 
725 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
726 {
727 	struct net *net = sock_net(skb->sk);
728 	struct fib_config cfg;
729 	struct fib_table *tb;
730 	int err;
731 
732 	err = rtm_to_fib_config(net, skb, nlh, &cfg);
733 	if (err < 0)
734 		goto errout;
735 
736 	tb = fib_new_table(net, cfg.fc_table);
737 	if (!tb) {
738 		err = -ENOBUFS;
739 		goto errout;
740 	}
741 
742 	err = fib_table_insert(net, tb, &cfg);
743 errout:
744 	return err;
745 }
746 
747 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
748 {
749 	struct net *net = sock_net(skb->sk);
750 	unsigned int h, s_h;
751 	unsigned int e = 0, s_e;
752 	struct fib_table *tb;
753 	struct hlist_head *head;
754 	int dumped = 0;
755 
756 	if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
757 	    ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
758 		return skb->len;
759 
760 	s_h = cb->args[0];
761 	s_e = cb->args[1];
762 
763 	rcu_read_lock();
764 
765 	for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
766 		e = 0;
767 		head = &net->ipv4.fib_table_hash[h];
768 		hlist_for_each_entry_rcu(tb, head, tb_hlist) {
769 			if (e < s_e)
770 				goto next;
771 			if (dumped)
772 				memset(&cb->args[2], 0, sizeof(cb->args) -
773 						 2 * sizeof(cb->args[0]));
774 			if (fib_table_dump(tb, skb, cb) < 0)
775 				goto out;
776 			dumped = 1;
777 next:
778 			e++;
779 		}
780 	}
781 out:
782 	rcu_read_unlock();
783 
784 	cb->args[1] = e;
785 	cb->args[0] = h;
786 
787 	return skb->len;
788 }
789 
790 /* Prepare and feed intra-kernel routing request.
791  * Really, it should be netlink message, but :-( netlink
792  * can be not configured, so that we feed it directly
793  * to fib engine. It is legal, because all events occur
794  * only when netlink is already locked.
795  */
796 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
797 {
798 	struct net *net = dev_net(ifa->ifa_dev->dev);
799 	u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
800 	struct fib_table *tb;
801 	struct fib_config cfg = {
802 		.fc_protocol = RTPROT_KERNEL,
803 		.fc_type = type,
804 		.fc_dst = dst,
805 		.fc_dst_len = dst_len,
806 		.fc_prefsrc = ifa->ifa_local,
807 		.fc_oif = ifa->ifa_dev->dev->ifindex,
808 		.fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
809 		.fc_nlinfo = {
810 			.nl_net = net,
811 		},
812 	};
813 
814 	if (!tb_id)
815 		tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
816 
817 	tb = fib_new_table(net, tb_id);
818 	if (!tb)
819 		return;
820 
821 	cfg.fc_table = tb->tb_id;
822 
823 	if (type != RTN_LOCAL)
824 		cfg.fc_scope = RT_SCOPE_LINK;
825 	else
826 		cfg.fc_scope = RT_SCOPE_HOST;
827 
828 	if (cmd == RTM_NEWROUTE)
829 		fib_table_insert(net, tb, &cfg);
830 	else
831 		fib_table_delete(net, tb, &cfg);
832 }
833 
834 void fib_add_ifaddr(struct in_ifaddr *ifa)
835 {
836 	struct in_device *in_dev = ifa->ifa_dev;
837 	struct net_device *dev = in_dev->dev;
838 	struct in_ifaddr *prim = ifa;
839 	__be32 mask = ifa->ifa_mask;
840 	__be32 addr = ifa->ifa_local;
841 	__be32 prefix = ifa->ifa_address & mask;
842 
843 	if (ifa->ifa_flags & IFA_F_SECONDARY) {
844 		prim = inet_ifa_byprefix(in_dev, prefix, mask);
845 		if (!prim) {
846 			pr_warn("%s: bug: prim == NULL\n", __func__);
847 			return;
848 		}
849 	}
850 
851 	fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
852 
853 	if (!(dev->flags & IFF_UP))
854 		return;
855 
856 	/* Add broadcast address, if it is explicitly assigned. */
857 	if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
858 		fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
859 
860 	if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
861 	    (prefix != addr || ifa->ifa_prefixlen < 32)) {
862 		if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
863 			fib_magic(RTM_NEWROUTE,
864 				  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
865 				  prefix, ifa->ifa_prefixlen, prim);
866 
867 		/* Add network specific broadcasts, when it takes a sense */
868 		if (ifa->ifa_prefixlen < 31) {
869 			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
870 			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
871 				  32, prim);
872 		}
873 	}
874 }
875 
876 /* Delete primary or secondary address.
877  * Optionally, on secondary address promotion consider the addresses
878  * from subnet iprim as deleted, even if they are in device list.
879  * In this case the secondary ifa can be in device list.
880  */
881 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
882 {
883 	struct in_device *in_dev = ifa->ifa_dev;
884 	struct net_device *dev = in_dev->dev;
885 	struct in_ifaddr *ifa1;
886 	struct in_ifaddr *prim = ifa, *prim1 = NULL;
887 	__be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
888 	__be32 any = ifa->ifa_address & ifa->ifa_mask;
889 #define LOCAL_OK	1
890 #define BRD_OK		2
891 #define BRD0_OK		4
892 #define BRD1_OK		8
893 	unsigned int ok = 0;
894 	int subnet = 0;		/* Primary network */
895 	int gone = 1;		/* Address is missing */
896 	int same_prefsrc = 0;	/* Another primary with same IP */
897 
898 	if (ifa->ifa_flags & IFA_F_SECONDARY) {
899 		prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
900 		if (!prim) {
901 			/* if the device has been deleted, we don't perform
902 			 * address promotion
903 			 */
904 			if (!in_dev->dead)
905 				pr_warn("%s: bug: prim == NULL\n", __func__);
906 			return;
907 		}
908 		if (iprim && iprim != prim) {
909 			pr_warn("%s: bug: iprim != prim\n", __func__);
910 			return;
911 		}
912 	} else if (!ipv4_is_zeronet(any) &&
913 		   (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
914 		if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
915 			fib_magic(RTM_DELROUTE,
916 				  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
917 				  any, ifa->ifa_prefixlen, prim);
918 		subnet = 1;
919 	}
920 
921 	if (in_dev->dead)
922 		goto no_promotions;
923 
924 	/* Deletion is more complicated than add.
925 	 * We should take care of not to delete too much :-)
926 	 *
927 	 * Scan address list to be sure that addresses are really gone.
928 	 */
929 
930 	for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
931 		if (ifa1 == ifa) {
932 			/* promotion, keep the IP */
933 			gone = 0;
934 			continue;
935 		}
936 		/* Ignore IFAs from our subnet */
937 		if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
938 		    inet_ifa_match(ifa1->ifa_address, iprim))
939 			continue;
940 
941 		/* Ignore ifa1 if it uses different primary IP (prefsrc) */
942 		if (ifa1->ifa_flags & IFA_F_SECONDARY) {
943 			/* Another address from our subnet? */
944 			if (ifa1->ifa_mask == prim->ifa_mask &&
945 			    inet_ifa_match(ifa1->ifa_address, prim))
946 				prim1 = prim;
947 			else {
948 				/* We reached the secondaries, so
949 				 * same_prefsrc should be determined.
950 				 */
951 				if (!same_prefsrc)
952 					continue;
953 				/* Search new prim1 if ifa1 is not
954 				 * using the current prim1
955 				 */
956 				if (!prim1 ||
957 				    ifa1->ifa_mask != prim1->ifa_mask ||
958 				    !inet_ifa_match(ifa1->ifa_address, prim1))
959 					prim1 = inet_ifa_byprefix(in_dev,
960 							ifa1->ifa_address,
961 							ifa1->ifa_mask);
962 				if (!prim1)
963 					continue;
964 				if (prim1->ifa_local != prim->ifa_local)
965 					continue;
966 			}
967 		} else {
968 			if (prim->ifa_local != ifa1->ifa_local)
969 				continue;
970 			prim1 = ifa1;
971 			if (prim != prim1)
972 				same_prefsrc = 1;
973 		}
974 		if (ifa->ifa_local == ifa1->ifa_local)
975 			ok |= LOCAL_OK;
976 		if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
977 			ok |= BRD_OK;
978 		if (brd == ifa1->ifa_broadcast)
979 			ok |= BRD1_OK;
980 		if (any == ifa1->ifa_broadcast)
981 			ok |= BRD0_OK;
982 		/* primary has network specific broadcasts */
983 		if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
984 			__be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
985 			__be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
986 
987 			if (!ipv4_is_zeronet(any1)) {
988 				if (ifa->ifa_broadcast == brd1 ||
989 				    ifa->ifa_broadcast == any1)
990 					ok |= BRD_OK;
991 				if (brd == brd1 || brd == any1)
992 					ok |= BRD1_OK;
993 				if (any == brd1 || any == any1)
994 					ok |= BRD0_OK;
995 			}
996 		}
997 	}
998 
999 no_promotions:
1000 	if (!(ok & BRD_OK))
1001 		fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
1002 	if (subnet && ifa->ifa_prefixlen < 31) {
1003 		if (!(ok & BRD1_OK))
1004 			fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
1005 		if (!(ok & BRD0_OK))
1006 			fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
1007 	}
1008 	if (!(ok & LOCAL_OK)) {
1009 		unsigned int addr_type;
1010 
1011 		fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
1012 
1013 		/* Check, that this local address finally disappeared. */
1014 		addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1015 						     ifa->ifa_local);
1016 		if (gone && addr_type != RTN_LOCAL) {
1017 			/* And the last, but not the least thing.
1018 			 * We must flush stray FIB entries.
1019 			 *
1020 			 * First of all, we scan fib_info list searching
1021 			 * for stray nexthop entries, then ignite fib_flush.
1022 			 */
1023 			if (fib_sync_down_addr(dev, ifa->ifa_local))
1024 				fib_flush(dev_net(dev));
1025 		}
1026 	}
1027 #undef LOCAL_OK
1028 #undef BRD_OK
1029 #undef BRD0_OK
1030 #undef BRD1_OK
1031 }
1032 
1033 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1034 {
1035 
1036 	struct fib_result       res;
1037 	struct flowi4           fl4 = {
1038 		.flowi4_mark = frn->fl_mark,
1039 		.daddr = frn->fl_addr,
1040 		.flowi4_tos = frn->fl_tos,
1041 		.flowi4_scope = frn->fl_scope,
1042 	};
1043 	struct fib_table *tb;
1044 
1045 	rcu_read_lock();
1046 
1047 	tb = fib_get_table(net, frn->tb_id_in);
1048 
1049 	frn->err = -ENOENT;
1050 	if (tb) {
1051 		local_bh_disable();
1052 
1053 		frn->tb_id = tb->tb_id;
1054 		frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1055 
1056 		if (!frn->err) {
1057 			frn->prefixlen = res.prefixlen;
1058 			frn->nh_sel = res.nh_sel;
1059 			frn->type = res.type;
1060 			frn->scope = res.scope;
1061 		}
1062 		local_bh_enable();
1063 	}
1064 
1065 	rcu_read_unlock();
1066 }
1067 
1068 static void nl_fib_input(struct sk_buff *skb)
1069 {
1070 	struct net *net;
1071 	struct fib_result_nl *frn;
1072 	struct nlmsghdr *nlh;
1073 	u32 portid;
1074 
1075 	net = sock_net(skb->sk);
1076 	nlh = nlmsg_hdr(skb);
1077 	if (skb->len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len ||
1078 	    nlmsg_len(nlh) < sizeof(*frn))
1079 		return;
1080 
1081 	skb = netlink_skb_clone(skb, GFP_KERNEL);
1082 	if (!skb)
1083 		return;
1084 	nlh = nlmsg_hdr(skb);
1085 
1086 	frn = (struct fib_result_nl *) nlmsg_data(nlh);
1087 	nl_fib_lookup(net, frn);
1088 
1089 	portid = NETLINK_CB(skb).portid;      /* netlink portid */
1090 	NETLINK_CB(skb).portid = 0;        /* from kernel */
1091 	NETLINK_CB(skb).dst_group = 0;  /* unicast */
1092 	netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1093 }
1094 
1095 static int __net_init nl_fib_lookup_init(struct net *net)
1096 {
1097 	struct sock *sk;
1098 	struct netlink_kernel_cfg cfg = {
1099 		.input	= nl_fib_input,
1100 	};
1101 
1102 	sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1103 	if (!sk)
1104 		return -EAFNOSUPPORT;
1105 	net->ipv4.fibnl = sk;
1106 	return 0;
1107 }
1108 
1109 static void nl_fib_lookup_exit(struct net *net)
1110 {
1111 	netlink_kernel_release(net->ipv4.fibnl);
1112 	net->ipv4.fibnl = NULL;
1113 }
1114 
1115 static void fib_disable_ip(struct net_device *dev, unsigned long event,
1116 			   bool force)
1117 {
1118 	if (fib_sync_down_dev(dev, event, force))
1119 		fib_flush(dev_net(dev));
1120 	rt_cache_flush(dev_net(dev));
1121 	arp_ifdown(dev);
1122 }
1123 
1124 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1125 {
1126 	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1127 	struct net_device *dev = ifa->ifa_dev->dev;
1128 	struct net *net = dev_net(dev);
1129 
1130 	switch (event) {
1131 	case NETDEV_UP:
1132 		fib_add_ifaddr(ifa);
1133 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1134 		fib_sync_up(dev, RTNH_F_DEAD);
1135 #endif
1136 		atomic_inc(&net->ipv4.dev_addr_genid);
1137 		rt_cache_flush(dev_net(dev));
1138 		break;
1139 	case NETDEV_DOWN:
1140 		fib_del_ifaddr(ifa, NULL);
1141 		atomic_inc(&net->ipv4.dev_addr_genid);
1142 		if (!ifa->ifa_dev->ifa_list) {
1143 			/* Last address was deleted from this interface.
1144 			 * Disable IP.
1145 			 */
1146 			fib_disable_ip(dev, event, true);
1147 		} else {
1148 			rt_cache_flush(dev_net(dev));
1149 		}
1150 		break;
1151 	}
1152 	return NOTIFY_DONE;
1153 }
1154 
1155 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1156 {
1157 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1158 	struct netdev_notifier_changeupper_info *info;
1159 	struct in_device *in_dev;
1160 	struct net *net = dev_net(dev);
1161 	unsigned int flags;
1162 
1163 	if (event == NETDEV_UNREGISTER) {
1164 		fib_disable_ip(dev, event, true);
1165 		rt_flush_dev(dev);
1166 		return NOTIFY_DONE;
1167 	}
1168 
1169 	in_dev = __in_dev_get_rtnl(dev);
1170 	if (!in_dev)
1171 		return NOTIFY_DONE;
1172 
1173 	switch (event) {
1174 	case NETDEV_UP:
1175 		for_ifa(in_dev) {
1176 			fib_add_ifaddr(ifa);
1177 		} endfor_ifa(in_dev);
1178 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1179 		fib_sync_up(dev, RTNH_F_DEAD);
1180 #endif
1181 		atomic_inc(&net->ipv4.dev_addr_genid);
1182 		rt_cache_flush(net);
1183 		break;
1184 	case NETDEV_DOWN:
1185 		fib_disable_ip(dev, event, false);
1186 		break;
1187 	case NETDEV_CHANGE:
1188 		flags = dev_get_flags(dev);
1189 		if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1190 			fib_sync_up(dev, RTNH_F_LINKDOWN);
1191 		else
1192 			fib_sync_down_dev(dev, event, false);
1193 		/* fall through */
1194 	case NETDEV_CHANGEMTU:
1195 		rt_cache_flush(net);
1196 		break;
1197 	case NETDEV_CHANGEUPPER:
1198 		info = ptr;
1199 		/* flush all routes if dev is linked to or unlinked from
1200 		 * an L3 master device (e.g., VRF)
1201 		 */
1202 		if (info->upper_dev && netif_is_l3_master(info->upper_dev))
1203 			fib_disable_ip(dev, NETDEV_DOWN, true);
1204 		break;
1205 	}
1206 	return NOTIFY_DONE;
1207 }
1208 
1209 static struct notifier_block fib_inetaddr_notifier = {
1210 	.notifier_call = fib_inetaddr_event,
1211 };
1212 
1213 static struct notifier_block fib_netdev_notifier = {
1214 	.notifier_call = fib_netdev_event,
1215 };
1216 
1217 static int __net_init ip_fib_net_init(struct net *net)
1218 {
1219 	int err;
1220 	size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1221 
1222 	net->ipv4.fib_seq = 0;
1223 
1224 	/* Avoid false sharing : Use at least a full cache line */
1225 	size = max_t(size_t, size, L1_CACHE_BYTES);
1226 
1227 	net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1228 	if (!net->ipv4.fib_table_hash)
1229 		return -ENOMEM;
1230 
1231 	err = fib4_rules_init(net);
1232 	if (err < 0)
1233 		goto fail;
1234 	return 0;
1235 
1236 fail:
1237 	kfree(net->ipv4.fib_table_hash);
1238 	return err;
1239 }
1240 
1241 static void ip_fib_net_exit(struct net *net)
1242 {
1243 	unsigned int i;
1244 
1245 	rtnl_lock();
1246 #ifdef CONFIG_IP_MULTIPLE_TABLES
1247 	RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1248 	RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1249 #endif
1250 	for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1251 		struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1252 		struct hlist_node *tmp;
1253 		struct fib_table *tb;
1254 
1255 		hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1256 			hlist_del(&tb->tb_hlist);
1257 			fib_table_flush(net, tb);
1258 			fib_free_table(tb);
1259 		}
1260 	}
1261 
1262 #ifdef CONFIG_IP_MULTIPLE_TABLES
1263 	fib4_rules_exit(net);
1264 #endif
1265 	rtnl_unlock();
1266 	kfree(net->ipv4.fib_table_hash);
1267 }
1268 
1269 static int __net_init fib_net_init(struct net *net)
1270 {
1271 	int error;
1272 
1273 #ifdef CONFIG_IP_ROUTE_CLASSID
1274 	net->ipv4.fib_num_tclassid_users = 0;
1275 #endif
1276 	error = ip_fib_net_init(net);
1277 	if (error < 0)
1278 		goto out;
1279 	error = nl_fib_lookup_init(net);
1280 	if (error < 0)
1281 		goto out_nlfl;
1282 	error = fib_proc_init(net);
1283 	if (error < 0)
1284 		goto out_proc;
1285 out:
1286 	return error;
1287 
1288 out_proc:
1289 	nl_fib_lookup_exit(net);
1290 out_nlfl:
1291 	ip_fib_net_exit(net);
1292 	goto out;
1293 }
1294 
1295 static void __net_exit fib_net_exit(struct net *net)
1296 {
1297 	fib_proc_exit(net);
1298 	nl_fib_lookup_exit(net);
1299 	ip_fib_net_exit(net);
1300 }
1301 
1302 static struct pernet_operations fib_net_ops = {
1303 	.init = fib_net_init,
1304 	.exit = fib_net_exit,
1305 };
1306 
1307 void __init ip_fib_init(void)
1308 {
1309 	rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1310 	rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1311 	rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1312 
1313 	register_pernet_subsys(&fib_net_ops);
1314 	register_netdevice_notifier(&fib_netdev_notifier);
1315 	register_inetaddr_notifier(&fib_inetaddr_notifier);
1316 
1317 	fib_trie_init();
1318 }
1319