xref: /openbmc/linux/net/ipv4/fib_frontend.c (revision 680ef72a)
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 <net/lwtunnel.h>
50 #include <trace/events/fib.h>
51 
52 #ifndef CONFIG_IP_MULTIPLE_TABLES
53 
54 static int __net_init fib4_rules_init(struct net *net)
55 {
56 	struct fib_table *local_table, *main_table;
57 
58 	main_table  = fib_trie_table(RT_TABLE_MAIN, NULL);
59 	if (!main_table)
60 		return -ENOMEM;
61 
62 	local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
63 	if (!local_table)
64 		goto fail;
65 
66 	hlist_add_head_rcu(&local_table->tb_hlist,
67 				&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
68 	hlist_add_head_rcu(&main_table->tb_hlist,
69 				&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
70 	return 0;
71 
72 fail:
73 	fib_free_table(main_table);
74 	return -ENOMEM;
75 }
76 
77 static bool fib4_has_custom_rules(struct net *net)
78 {
79 	return false;
80 }
81 #else
82 
83 struct fib_table *fib_new_table(struct net *net, u32 id)
84 {
85 	struct fib_table *tb, *alias = NULL;
86 	unsigned int h;
87 
88 	if (id == 0)
89 		id = RT_TABLE_MAIN;
90 	tb = fib_get_table(net, id);
91 	if (tb)
92 		return tb;
93 
94 	if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules)
95 		alias = fib_new_table(net, RT_TABLE_MAIN);
96 
97 	tb = fib_trie_table(id, alias);
98 	if (!tb)
99 		return NULL;
100 
101 	switch (id) {
102 	case RT_TABLE_MAIN:
103 		rcu_assign_pointer(net->ipv4.fib_main, tb);
104 		break;
105 	case RT_TABLE_DEFAULT:
106 		rcu_assign_pointer(net->ipv4.fib_default, tb);
107 		break;
108 	default:
109 		break;
110 	}
111 
112 	h = id & (FIB_TABLE_HASHSZ - 1);
113 	hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
114 	return tb;
115 }
116 EXPORT_SYMBOL_GPL(fib_new_table);
117 
118 /* caller must hold either rtnl or rcu read lock */
119 struct fib_table *fib_get_table(struct net *net, u32 id)
120 {
121 	struct fib_table *tb;
122 	struct hlist_head *head;
123 	unsigned int h;
124 
125 	if (id == 0)
126 		id = RT_TABLE_MAIN;
127 	h = id & (FIB_TABLE_HASHSZ - 1);
128 
129 	head = &net->ipv4.fib_table_hash[h];
130 	hlist_for_each_entry_rcu(tb, head, tb_hlist) {
131 		if (tb->tb_id == id)
132 			return tb;
133 	}
134 	return NULL;
135 }
136 
137 static bool fib4_has_custom_rules(struct net *net)
138 {
139 	return net->ipv4.fib_has_custom_rules;
140 }
141 #endif /* CONFIG_IP_MULTIPLE_TABLES */
142 
143 static void fib_replace_table(struct net *net, struct fib_table *old,
144 			      struct fib_table *new)
145 {
146 #ifdef CONFIG_IP_MULTIPLE_TABLES
147 	switch (new->tb_id) {
148 	case RT_TABLE_MAIN:
149 		rcu_assign_pointer(net->ipv4.fib_main, new);
150 		break;
151 	case RT_TABLE_DEFAULT:
152 		rcu_assign_pointer(net->ipv4.fib_default, new);
153 		break;
154 	default:
155 		break;
156 	}
157 
158 #endif
159 	/* replace the old table in the hlist */
160 	hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
161 }
162 
163 int fib_unmerge(struct net *net)
164 {
165 	struct fib_table *old, *new, *main_table;
166 
167 	/* attempt to fetch local table if it has been allocated */
168 	old = fib_get_table(net, RT_TABLE_LOCAL);
169 	if (!old)
170 		return 0;
171 
172 	new = fib_trie_unmerge(old);
173 	if (!new)
174 		return -ENOMEM;
175 
176 	/* table is already unmerged */
177 	if (new == old)
178 		return 0;
179 
180 	/* replace merged table with clean table */
181 	fib_replace_table(net, old, new);
182 	fib_free_table(old);
183 
184 	/* attempt to fetch main table if it has been allocated */
185 	main_table = fib_get_table(net, RT_TABLE_MAIN);
186 	if (!main_table)
187 		return 0;
188 
189 	/* flush local entries from main table */
190 	fib_table_flush_external(main_table);
191 
192 	return 0;
193 }
194 
195 static void fib_flush(struct net *net)
196 {
197 	int flushed = 0;
198 	unsigned int h;
199 
200 	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
201 		struct hlist_head *head = &net->ipv4.fib_table_hash[h];
202 		struct hlist_node *tmp;
203 		struct fib_table *tb;
204 
205 		hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
206 			flushed += fib_table_flush(net, tb);
207 	}
208 
209 	if (flushed)
210 		rt_cache_flush(net);
211 }
212 
213 /*
214  * Find address type as if only "dev" was present in the system. If
215  * on_dev is NULL then all interfaces are taken into consideration.
216  */
217 static inline unsigned int __inet_dev_addr_type(struct net *net,
218 						const struct net_device *dev,
219 						__be32 addr, u32 tb_id)
220 {
221 	struct flowi4		fl4 = { .daddr = addr };
222 	struct fib_result	res;
223 	unsigned int ret = RTN_BROADCAST;
224 	struct fib_table *table;
225 
226 	if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
227 		return RTN_BROADCAST;
228 	if (ipv4_is_multicast(addr))
229 		return RTN_MULTICAST;
230 
231 	rcu_read_lock();
232 
233 	table = fib_get_table(net, tb_id);
234 	if (table) {
235 		ret = RTN_UNICAST;
236 		if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
237 			if (!dev || dev == res.fi->fib_dev)
238 				ret = res.type;
239 		}
240 	}
241 
242 	rcu_read_unlock();
243 	return ret;
244 }
245 
246 unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
247 {
248 	return __inet_dev_addr_type(net, NULL, addr, tb_id);
249 }
250 EXPORT_SYMBOL(inet_addr_type_table);
251 
252 unsigned int inet_addr_type(struct net *net, __be32 addr)
253 {
254 	return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
255 }
256 EXPORT_SYMBOL(inet_addr_type);
257 
258 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
259 				__be32 addr)
260 {
261 	u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
262 
263 	return __inet_dev_addr_type(net, dev, addr, rt_table);
264 }
265 EXPORT_SYMBOL(inet_dev_addr_type);
266 
267 /* inet_addr_type with dev == NULL but using the table from a dev
268  * if one is associated
269  */
270 unsigned int inet_addr_type_dev_table(struct net *net,
271 				      const struct net_device *dev,
272 				      __be32 addr)
273 {
274 	u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
275 
276 	return __inet_dev_addr_type(net, NULL, addr, rt_table);
277 }
278 EXPORT_SYMBOL(inet_addr_type_dev_table);
279 
280 __be32 fib_compute_spec_dst(struct sk_buff *skb)
281 {
282 	struct net_device *dev = skb->dev;
283 	struct in_device *in_dev;
284 	struct fib_result res;
285 	struct rtable *rt;
286 	struct net *net;
287 	int scope;
288 
289 	rt = skb_rtable(skb);
290 	if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
291 	    RTCF_LOCAL)
292 		return ip_hdr(skb)->daddr;
293 
294 	in_dev = __in_dev_get_rcu(dev);
295 	BUG_ON(!in_dev);
296 
297 	net = dev_net(dev);
298 
299 	scope = RT_SCOPE_UNIVERSE;
300 	if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
301 		struct flowi4 fl4 = {
302 			.flowi4_iif = LOOPBACK_IFINDEX,
303 			.daddr = ip_hdr(skb)->saddr,
304 			.flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
305 			.flowi4_scope = scope,
306 			.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0,
307 		};
308 		if (!fib_lookup(net, &fl4, &res, 0))
309 			return FIB_RES_PREFSRC(net, res);
310 	} else {
311 		scope = RT_SCOPE_LINK;
312 	}
313 
314 	return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
315 }
316 
317 /* Given (packet source, input interface) and optional (dst, oif, tos):
318  * - (main) check, that source is valid i.e. not broadcast or our local
319  *   address.
320  * - figure out what "logical" interface this packet arrived
321  *   and calculate "specific destination" address.
322  * - check, that packet arrived from expected physical interface.
323  * called with rcu_read_lock()
324  */
325 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
326 				 u8 tos, int oif, struct net_device *dev,
327 				 int rpf, struct in_device *idev, u32 *itag)
328 {
329 	int ret, no_addr;
330 	struct fib_result res;
331 	struct flowi4 fl4;
332 	struct net *net = dev_net(dev);
333 	bool dev_match;
334 
335 	fl4.flowi4_oif = 0;
336 	fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
337 	if (!fl4.flowi4_iif)
338 		fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
339 	fl4.daddr = src;
340 	fl4.saddr = dst;
341 	fl4.flowi4_tos = tos;
342 	fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
343 	fl4.flowi4_tun_key.tun_id = 0;
344 	fl4.flowi4_flags = 0;
345 	fl4.flowi4_uid = sock_net_uid(net, NULL);
346 
347 	no_addr = idev->ifa_list == NULL;
348 
349 	fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
350 
351 	trace_fib_validate_source(dev, &fl4);
352 
353 	if (fib_lookup(net, &fl4, &res, 0))
354 		goto last_resort;
355 	if (res.type != RTN_UNICAST &&
356 	    (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
357 		goto e_inval;
358 	fib_combine_itag(itag, &res);
359 	dev_match = false;
360 
361 #ifdef CONFIG_IP_ROUTE_MULTIPATH
362 	for (ret = 0; ret < res.fi->fib_nhs; ret++) {
363 		struct fib_nh *nh = &res.fi->fib_nh[ret];
364 
365 		if (nh->nh_dev == dev) {
366 			dev_match = true;
367 			break;
368 		} else if (l3mdev_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
369 			dev_match = true;
370 			break;
371 		}
372 	}
373 #else
374 	if (FIB_RES_DEV(res) == dev)
375 		dev_match = true;
376 #endif
377 	if (dev_match) {
378 		ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
379 		return ret;
380 	}
381 	if (no_addr)
382 		goto last_resort;
383 	if (rpf == 1)
384 		goto e_rpf;
385 	fl4.flowi4_oif = dev->ifindex;
386 
387 	ret = 0;
388 	if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
389 		if (res.type == RTN_UNICAST)
390 			ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
391 	}
392 	return ret;
393 
394 last_resort:
395 	if (rpf)
396 		goto e_rpf;
397 	*itag = 0;
398 	return 0;
399 
400 e_inval:
401 	return -EINVAL;
402 e_rpf:
403 	return -EXDEV;
404 }
405 
406 /* Ignore rp_filter for packets protected by IPsec. */
407 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
408 			u8 tos, int oif, struct net_device *dev,
409 			struct in_device *idev, u32 *itag)
410 {
411 	int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
412 	struct net *net = dev_net(dev);
413 
414 	if (!r && !fib_num_tclassid_users(net) &&
415 	    (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
416 		if (IN_DEV_ACCEPT_LOCAL(idev))
417 			goto ok;
418 		/* with custom local routes in place, checking local addresses
419 		 * only will be too optimistic, with custom rules, checking
420 		 * local addresses only can be too strict, e.g. due to vrf
421 		 */
422 		if (net->ipv4.fib_has_custom_local_routes ||
423 		    fib4_has_custom_rules(net))
424 			goto full_check;
425 		if (inet_lookup_ifaddr_rcu(net, src))
426 			return -EINVAL;
427 
428 ok:
429 		*itag = 0;
430 		return 0;
431 	}
432 
433 full_check:
434 	return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
435 }
436 
437 static inline __be32 sk_extract_addr(struct sockaddr *addr)
438 {
439 	return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
440 }
441 
442 static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
443 {
444 	struct nlattr *nla;
445 
446 	nla = (struct nlattr *) ((char *) mx + len);
447 	nla->nla_type = type;
448 	nla->nla_len = nla_attr_size(4);
449 	*(u32 *) nla_data(nla) = value;
450 
451 	return len + nla_total_size(4);
452 }
453 
454 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
455 				 struct fib_config *cfg)
456 {
457 	__be32 addr;
458 	int plen;
459 
460 	memset(cfg, 0, sizeof(*cfg));
461 	cfg->fc_nlinfo.nl_net = net;
462 
463 	if (rt->rt_dst.sa_family != AF_INET)
464 		return -EAFNOSUPPORT;
465 
466 	/*
467 	 * Check mask for validity:
468 	 * a) it must be contiguous.
469 	 * b) destination must have all host bits clear.
470 	 * c) if application forgot to set correct family (AF_INET),
471 	 *    reject request unless it is absolutely clear i.e.
472 	 *    both family and mask are zero.
473 	 */
474 	plen = 32;
475 	addr = sk_extract_addr(&rt->rt_dst);
476 	if (!(rt->rt_flags & RTF_HOST)) {
477 		__be32 mask = sk_extract_addr(&rt->rt_genmask);
478 
479 		if (rt->rt_genmask.sa_family != AF_INET) {
480 			if (mask || rt->rt_genmask.sa_family)
481 				return -EAFNOSUPPORT;
482 		}
483 
484 		if (bad_mask(mask, addr))
485 			return -EINVAL;
486 
487 		plen = inet_mask_len(mask);
488 	}
489 
490 	cfg->fc_dst_len = plen;
491 	cfg->fc_dst = addr;
492 
493 	if (cmd != SIOCDELRT) {
494 		cfg->fc_nlflags = NLM_F_CREATE;
495 		cfg->fc_protocol = RTPROT_BOOT;
496 	}
497 
498 	if (rt->rt_metric)
499 		cfg->fc_priority = rt->rt_metric - 1;
500 
501 	if (rt->rt_flags & RTF_REJECT) {
502 		cfg->fc_scope = RT_SCOPE_HOST;
503 		cfg->fc_type = RTN_UNREACHABLE;
504 		return 0;
505 	}
506 
507 	cfg->fc_scope = RT_SCOPE_NOWHERE;
508 	cfg->fc_type = RTN_UNICAST;
509 
510 	if (rt->rt_dev) {
511 		char *colon;
512 		struct net_device *dev;
513 		char devname[IFNAMSIZ];
514 
515 		if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
516 			return -EFAULT;
517 
518 		devname[IFNAMSIZ-1] = 0;
519 		colon = strchr(devname, ':');
520 		if (colon)
521 			*colon = 0;
522 		dev = __dev_get_by_name(net, devname);
523 		if (!dev)
524 			return -ENODEV;
525 		cfg->fc_oif = dev->ifindex;
526 		cfg->fc_table = l3mdev_fib_table(dev);
527 		if (colon) {
528 			struct in_ifaddr *ifa;
529 			struct in_device *in_dev = __in_dev_get_rtnl(dev);
530 			if (!in_dev)
531 				return -ENODEV;
532 			*colon = ':';
533 			for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
534 				if (strcmp(ifa->ifa_label, devname) == 0)
535 					break;
536 			if (!ifa)
537 				return -ENODEV;
538 			cfg->fc_prefsrc = ifa->ifa_local;
539 		}
540 	}
541 
542 	addr = sk_extract_addr(&rt->rt_gateway);
543 	if (rt->rt_gateway.sa_family == AF_INET && addr) {
544 		unsigned int addr_type;
545 
546 		cfg->fc_gw = addr;
547 		addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
548 		if (rt->rt_flags & RTF_GATEWAY &&
549 		    addr_type == RTN_UNICAST)
550 			cfg->fc_scope = RT_SCOPE_UNIVERSE;
551 	}
552 
553 	if (cmd == SIOCDELRT)
554 		return 0;
555 
556 	if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
557 		return -EINVAL;
558 
559 	if (cfg->fc_scope == RT_SCOPE_NOWHERE)
560 		cfg->fc_scope = RT_SCOPE_LINK;
561 
562 	if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
563 		struct nlattr *mx;
564 		int len = 0;
565 
566 		mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
567 		if (!mx)
568 			return -ENOMEM;
569 
570 		if (rt->rt_flags & RTF_MTU)
571 			len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
572 
573 		if (rt->rt_flags & RTF_WINDOW)
574 			len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
575 
576 		if (rt->rt_flags & RTF_IRTT)
577 			len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
578 
579 		cfg->fc_mx = mx;
580 		cfg->fc_mx_len = len;
581 	}
582 
583 	return 0;
584 }
585 
586 /*
587  * Handle IP routing ioctl calls.
588  * These are used to manipulate the routing tables
589  */
590 int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
591 {
592 	struct fib_config cfg;
593 	struct rtentry rt;
594 	int err;
595 
596 	switch (cmd) {
597 	case SIOCADDRT:		/* Add a route */
598 	case SIOCDELRT:		/* Delete a route */
599 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
600 			return -EPERM;
601 
602 		if (copy_from_user(&rt, arg, sizeof(rt)))
603 			return -EFAULT;
604 
605 		rtnl_lock();
606 		err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
607 		if (err == 0) {
608 			struct fib_table *tb;
609 
610 			if (cmd == SIOCDELRT) {
611 				tb = fib_get_table(net, cfg.fc_table);
612 				if (tb)
613 					err = fib_table_delete(net, tb, &cfg,
614 							       NULL);
615 				else
616 					err = -ESRCH;
617 			} else {
618 				tb = fib_new_table(net, cfg.fc_table);
619 				if (tb)
620 					err = fib_table_insert(net, tb,
621 							       &cfg, NULL);
622 				else
623 					err = -ENOBUFS;
624 			}
625 
626 			/* allocated by rtentry_to_fib_config() */
627 			kfree(cfg.fc_mx);
628 		}
629 		rtnl_unlock();
630 		return err;
631 	}
632 	return -EINVAL;
633 }
634 
635 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
636 	[RTA_DST]		= { .type = NLA_U32 },
637 	[RTA_SRC]		= { .type = NLA_U32 },
638 	[RTA_IIF]		= { .type = NLA_U32 },
639 	[RTA_OIF]		= { .type = NLA_U32 },
640 	[RTA_GATEWAY]		= { .type = NLA_U32 },
641 	[RTA_PRIORITY]		= { .type = NLA_U32 },
642 	[RTA_PREFSRC]		= { .type = NLA_U32 },
643 	[RTA_METRICS]		= { .type = NLA_NESTED },
644 	[RTA_MULTIPATH]		= { .len = sizeof(struct rtnexthop) },
645 	[RTA_FLOW]		= { .type = NLA_U32 },
646 	[RTA_ENCAP_TYPE]	= { .type = NLA_U16 },
647 	[RTA_ENCAP]		= { .type = NLA_NESTED },
648 	[RTA_UID]		= { .type = NLA_U32 },
649 	[RTA_MARK]		= { .type = NLA_U32 },
650 };
651 
652 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
653 			     struct nlmsghdr *nlh, struct fib_config *cfg,
654 			     struct netlink_ext_ack *extack)
655 {
656 	struct nlattr *attr;
657 	int err, remaining;
658 	struct rtmsg *rtm;
659 
660 	err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy,
661 			     extack);
662 	if (err < 0)
663 		goto errout;
664 
665 	memset(cfg, 0, sizeof(*cfg));
666 
667 	rtm = nlmsg_data(nlh);
668 	cfg->fc_dst_len = rtm->rtm_dst_len;
669 	cfg->fc_tos = rtm->rtm_tos;
670 	cfg->fc_table = rtm->rtm_table;
671 	cfg->fc_protocol = rtm->rtm_protocol;
672 	cfg->fc_scope = rtm->rtm_scope;
673 	cfg->fc_type = rtm->rtm_type;
674 	cfg->fc_flags = rtm->rtm_flags;
675 	cfg->fc_nlflags = nlh->nlmsg_flags;
676 
677 	cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
678 	cfg->fc_nlinfo.nlh = nlh;
679 	cfg->fc_nlinfo.nl_net = net;
680 
681 	if (cfg->fc_type > RTN_MAX) {
682 		NL_SET_ERR_MSG(extack, "Invalid route type");
683 		err = -EINVAL;
684 		goto errout;
685 	}
686 
687 	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
688 		switch (nla_type(attr)) {
689 		case RTA_DST:
690 			cfg->fc_dst = nla_get_be32(attr);
691 			break;
692 		case RTA_OIF:
693 			cfg->fc_oif = nla_get_u32(attr);
694 			break;
695 		case RTA_GATEWAY:
696 			cfg->fc_gw = nla_get_be32(attr);
697 			break;
698 		case RTA_PRIORITY:
699 			cfg->fc_priority = nla_get_u32(attr);
700 			break;
701 		case RTA_PREFSRC:
702 			cfg->fc_prefsrc = nla_get_be32(attr);
703 			break;
704 		case RTA_METRICS:
705 			cfg->fc_mx = nla_data(attr);
706 			cfg->fc_mx_len = nla_len(attr);
707 			break;
708 		case RTA_MULTIPATH:
709 			err = lwtunnel_valid_encap_type_attr(nla_data(attr),
710 							     nla_len(attr),
711 							     extack);
712 			if (err < 0)
713 				goto errout;
714 			cfg->fc_mp = nla_data(attr);
715 			cfg->fc_mp_len = nla_len(attr);
716 			break;
717 		case RTA_FLOW:
718 			cfg->fc_flow = nla_get_u32(attr);
719 			break;
720 		case RTA_TABLE:
721 			cfg->fc_table = nla_get_u32(attr);
722 			break;
723 		case RTA_ENCAP:
724 			cfg->fc_encap = attr;
725 			break;
726 		case RTA_ENCAP_TYPE:
727 			cfg->fc_encap_type = nla_get_u16(attr);
728 			err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
729 							extack);
730 			if (err < 0)
731 				goto errout;
732 			break;
733 		}
734 	}
735 
736 	return 0;
737 errout:
738 	return err;
739 }
740 
741 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
742 			     struct netlink_ext_ack *extack)
743 {
744 	struct net *net = sock_net(skb->sk);
745 	struct fib_config cfg;
746 	struct fib_table *tb;
747 	int err;
748 
749 	err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
750 	if (err < 0)
751 		goto errout;
752 
753 	tb = fib_get_table(net, cfg.fc_table);
754 	if (!tb) {
755 		NL_SET_ERR_MSG(extack, "FIB table does not exist");
756 		err = -ESRCH;
757 		goto errout;
758 	}
759 
760 	err = fib_table_delete(net, tb, &cfg, extack);
761 errout:
762 	return err;
763 }
764 
765 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
766 			     struct netlink_ext_ack *extack)
767 {
768 	struct net *net = sock_net(skb->sk);
769 	struct fib_config cfg;
770 	struct fib_table *tb;
771 	int err;
772 
773 	err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
774 	if (err < 0)
775 		goto errout;
776 
777 	tb = fib_new_table(net, cfg.fc_table);
778 	if (!tb) {
779 		err = -ENOBUFS;
780 		goto errout;
781 	}
782 
783 	err = fib_table_insert(net, tb, &cfg, extack);
784 	if (!err && cfg.fc_type == RTN_LOCAL)
785 		net->ipv4.fib_has_custom_local_routes = true;
786 errout:
787 	return err;
788 }
789 
790 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
791 {
792 	struct net *net = sock_net(skb->sk);
793 	unsigned int h, s_h;
794 	unsigned int e = 0, s_e;
795 	struct fib_table *tb;
796 	struct hlist_head *head;
797 	int dumped = 0, err;
798 
799 	if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
800 	    ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
801 		return skb->len;
802 
803 	s_h = cb->args[0];
804 	s_e = cb->args[1];
805 
806 	rcu_read_lock();
807 
808 	for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
809 		e = 0;
810 		head = &net->ipv4.fib_table_hash[h];
811 		hlist_for_each_entry_rcu(tb, head, tb_hlist) {
812 			if (e < s_e)
813 				goto next;
814 			if (dumped)
815 				memset(&cb->args[2], 0, sizeof(cb->args) -
816 						 2 * sizeof(cb->args[0]));
817 			err = fib_table_dump(tb, skb, cb);
818 			if (err < 0) {
819 				if (likely(skb->len))
820 					goto out;
821 
822 				goto out_err;
823 			}
824 			dumped = 1;
825 next:
826 			e++;
827 		}
828 	}
829 out:
830 	err = skb->len;
831 out_err:
832 	rcu_read_unlock();
833 
834 	cb->args[1] = e;
835 	cb->args[0] = h;
836 
837 	return err;
838 }
839 
840 /* Prepare and feed intra-kernel routing request.
841  * Really, it should be netlink message, but :-( netlink
842  * can be not configured, so that we feed it directly
843  * to fib engine. It is legal, because all events occur
844  * only when netlink is already locked.
845  */
846 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
847 {
848 	struct net *net = dev_net(ifa->ifa_dev->dev);
849 	u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
850 	struct fib_table *tb;
851 	struct fib_config cfg = {
852 		.fc_protocol = RTPROT_KERNEL,
853 		.fc_type = type,
854 		.fc_dst = dst,
855 		.fc_dst_len = dst_len,
856 		.fc_prefsrc = ifa->ifa_local,
857 		.fc_oif = ifa->ifa_dev->dev->ifindex,
858 		.fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
859 		.fc_nlinfo = {
860 			.nl_net = net,
861 		},
862 	};
863 
864 	if (!tb_id)
865 		tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
866 
867 	tb = fib_new_table(net, tb_id);
868 	if (!tb)
869 		return;
870 
871 	cfg.fc_table = tb->tb_id;
872 
873 	if (type != RTN_LOCAL)
874 		cfg.fc_scope = RT_SCOPE_LINK;
875 	else
876 		cfg.fc_scope = RT_SCOPE_HOST;
877 
878 	if (cmd == RTM_NEWROUTE)
879 		fib_table_insert(net, tb, &cfg, NULL);
880 	else
881 		fib_table_delete(net, tb, &cfg, NULL);
882 }
883 
884 void fib_add_ifaddr(struct in_ifaddr *ifa)
885 {
886 	struct in_device *in_dev = ifa->ifa_dev;
887 	struct net_device *dev = in_dev->dev;
888 	struct in_ifaddr *prim = ifa;
889 	__be32 mask = ifa->ifa_mask;
890 	__be32 addr = ifa->ifa_local;
891 	__be32 prefix = ifa->ifa_address & mask;
892 
893 	if (ifa->ifa_flags & IFA_F_SECONDARY) {
894 		prim = inet_ifa_byprefix(in_dev, prefix, mask);
895 		if (!prim) {
896 			pr_warn("%s: bug: prim == NULL\n", __func__);
897 			return;
898 		}
899 	}
900 
901 	fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
902 
903 	if (!(dev->flags & IFF_UP))
904 		return;
905 
906 	/* Add broadcast address, if it is explicitly assigned. */
907 	if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
908 		fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
909 
910 	if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
911 	    (prefix != addr || ifa->ifa_prefixlen < 32)) {
912 		if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
913 			fib_magic(RTM_NEWROUTE,
914 				  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
915 				  prefix, ifa->ifa_prefixlen, prim);
916 
917 		/* Add network specific broadcasts, when it takes a sense */
918 		if (ifa->ifa_prefixlen < 31) {
919 			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
920 			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
921 				  32, prim);
922 		}
923 	}
924 }
925 
926 /* Delete primary or secondary address.
927  * Optionally, on secondary address promotion consider the addresses
928  * from subnet iprim as deleted, even if they are in device list.
929  * In this case the secondary ifa can be in device list.
930  */
931 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
932 {
933 	struct in_device *in_dev = ifa->ifa_dev;
934 	struct net_device *dev = in_dev->dev;
935 	struct in_ifaddr *ifa1;
936 	struct in_ifaddr *prim = ifa, *prim1 = NULL;
937 	__be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
938 	__be32 any = ifa->ifa_address & ifa->ifa_mask;
939 #define LOCAL_OK	1
940 #define BRD_OK		2
941 #define BRD0_OK		4
942 #define BRD1_OK		8
943 	unsigned int ok = 0;
944 	int subnet = 0;		/* Primary network */
945 	int gone = 1;		/* Address is missing */
946 	int same_prefsrc = 0;	/* Another primary with same IP */
947 
948 	if (ifa->ifa_flags & IFA_F_SECONDARY) {
949 		prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
950 		if (!prim) {
951 			/* if the device has been deleted, we don't perform
952 			 * address promotion
953 			 */
954 			if (!in_dev->dead)
955 				pr_warn("%s: bug: prim == NULL\n", __func__);
956 			return;
957 		}
958 		if (iprim && iprim != prim) {
959 			pr_warn("%s: bug: iprim != prim\n", __func__);
960 			return;
961 		}
962 	} else if (!ipv4_is_zeronet(any) &&
963 		   (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
964 		if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
965 			fib_magic(RTM_DELROUTE,
966 				  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
967 				  any, ifa->ifa_prefixlen, prim);
968 		subnet = 1;
969 	}
970 
971 	if (in_dev->dead)
972 		goto no_promotions;
973 
974 	/* Deletion is more complicated than add.
975 	 * We should take care of not to delete too much :-)
976 	 *
977 	 * Scan address list to be sure that addresses are really gone.
978 	 */
979 
980 	for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
981 		if (ifa1 == ifa) {
982 			/* promotion, keep the IP */
983 			gone = 0;
984 			continue;
985 		}
986 		/* Ignore IFAs from our subnet */
987 		if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
988 		    inet_ifa_match(ifa1->ifa_address, iprim))
989 			continue;
990 
991 		/* Ignore ifa1 if it uses different primary IP (prefsrc) */
992 		if (ifa1->ifa_flags & IFA_F_SECONDARY) {
993 			/* Another address from our subnet? */
994 			if (ifa1->ifa_mask == prim->ifa_mask &&
995 			    inet_ifa_match(ifa1->ifa_address, prim))
996 				prim1 = prim;
997 			else {
998 				/* We reached the secondaries, so
999 				 * same_prefsrc should be determined.
1000 				 */
1001 				if (!same_prefsrc)
1002 					continue;
1003 				/* Search new prim1 if ifa1 is not
1004 				 * using the current prim1
1005 				 */
1006 				if (!prim1 ||
1007 				    ifa1->ifa_mask != prim1->ifa_mask ||
1008 				    !inet_ifa_match(ifa1->ifa_address, prim1))
1009 					prim1 = inet_ifa_byprefix(in_dev,
1010 							ifa1->ifa_address,
1011 							ifa1->ifa_mask);
1012 				if (!prim1)
1013 					continue;
1014 				if (prim1->ifa_local != prim->ifa_local)
1015 					continue;
1016 			}
1017 		} else {
1018 			if (prim->ifa_local != ifa1->ifa_local)
1019 				continue;
1020 			prim1 = ifa1;
1021 			if (prim != prim1)
1022 				same_prefsrc = 1;
1023 		}
1024 		if (ifa->ifa_local == ifa1->ifa_local)
1025 			ok |= LOCAL_OK;
1026 		if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1027 			ok |= BRD_OK;
1028 		if (brd == ifa1->ifa_broadcast)
1029 			ok |= BRD1_OK;
1030 		if (any == ifa1->ifa_broadcast)
1031 			ok |= BRD0_OK;
1032 		/* primary has network specific broadcasts */
1033 		if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1034 			__be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1035 			__be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1036 
1037 			if (!ipv4_is_zeronet(any1)) {
1038 				if (ifa->ifa_broadcast == brd1 ||
1039 				    ifa->ifa_broadcast == any1)
1040 					ok |= BRD_OK;
1041 				if (brd == brd1 || brd == any1)
1042 					ok |= BRD1_OK;
1043 				if (any == brd1 || any == any1)
1044 					ok |= BRD0_OK;
1045 			}
1046 		}
1047 	}
1048 
1049 no_promotions:
1050 	if (!(ok & BRD_OK))
1051 		fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
1052 	if (subnet && ifa->ifa_prefixlen < 31) {
1053 		if (!(ok & BRD1_OK))
1054 			fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
1055 		if (!(ok & BRD0_OK))
1056 			fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
1057 	}
1058 	if (!(ok & LOCAL_OK)) {
1059 		unsigned int addr_type;
1060 
1061 		fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
1062 
1063 		/* Check, that this local address finally disappeared. */
1064 		addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1065 						     ifa->ifa_local);
1066 		if (gone && addr_type != RTN_LOCAL) {
1067 			/* And the last, but not the least thing.
1068 			 * We must flush stray FIB entries.
1069 			 *
1070 			 * First of all, we scan fib_info list searching
1071 			 * for stray nexthop entries, then ignite fib_flush.
1072 			 */
1073 			if (fib_sync_down_addr(dev, ifa->ifa_local))
1074 				fib_flush(dev_net(dev));
1075 		}
1076 	}
1077 #undef LOCAL_OK
1078 #undef BRD_OK
1079 #undef BRD0_OK
1080 #undef BRD1_OK
1081 }
1082 
1083 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1084 {
1085 
1086 	struct fib_result       res;
1087 	struct flowi4           fl4 = {
1088 		.flowi4_mark = frn->fl_mark,
1089 		.daddr = frn->fl_addr,
1090 		.flowi4_tos = frn->fl_tos,
1091 		.flowi4_scope = frn->fl_scope,
1092 	};
1093 	struct fib_table *tb;
1094 
1095 	rcu_read_lock();
1096 
1097 	tb = fib_get_table(net, frn->tb_id_in);
1098 
1099 	frn->err = -ENOENT;
1100 	if (tb) {
1101 		local_bh_disable();
1102 
1103 		frn->tb_id = tb->tb_id;
1104 		frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1105 
1106 		if (!frn->err) {
1107 			frn->prefixlen = res.prefixlen;
1108 			frn->nh_sel = res.nh_sel;
1109 			frn->type = res.type;
1110 			frn->scope = res.scope;
1111 		}
1112 		local_bh_enable();
1113 	}
1114 
1115 	rcu_read_unlock();
1116 }
1117 
1118 static void nl_fib_input(struct sk_buff *skb)
1119 {
1120 	struct net *net;
1121 	struct fib_result_nl *frn;
1122 	struct nlmsghdr *nlh;
1123 	u32 portid;
1124 
1125 	net = sock_net(skb->sk);
1126 	nlh = nlmsg_hdr(skb);
1127 	if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1128 	    skb->len < nlh->nlmsg_len ||
1129 	    nlmsg_len(nlh) < sizeof(*frn))
1130 		return;
1131 
1132 	skb = netlink_skb_clone(skb, GFP_KERNEL);
1133 	if (!skb)
1134 		return;
1135 	nlh = nlmsg_hdr(skb);
1136 
1137 	frn = (struct fib_result_nl *) nlmsg_data(nlh);
1138 	nl_fib_lookup(net, frn);
1139 
1140 	portid = NETLINK_CB(skb).portid;      /* netlink portid */
1141 	NETLINK_CB(skb).portid = 0;        /* from kernel */
1142 	NETLINK_CB(skb).dst_group = 0;  /* unicast */
1143 	netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1144 }
1145 
1146 static int __net_init nl_fib_lookup_init(struct net *net)
1147 {
1148 	struct sock *sk;
1149 	struct netlink_kernel_cfg cfg = {
1150 		.input	= nl_fib_input,
1151 	};
1152 
1153 	sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1154 	if (!sk)
1155 		return -EAFNOSUPPORT;
1156 	net->ipv4.fibnl = sk;
1157 	return 0;
1158 }
1159 
1160 static void nl_fib_lookup_exit(struct net *net)
1161 {
1162 	netlink_kernel_release(net->ipv4.fibnl);
1163 	net->ipv4.fibnl = NULL;
1164 }
1165 
1166 static void fib_disable_ip(struct net_device *dev, unsigned long event,
1167 			   bool force)
1168 {
1169 	if (fib_sync_down_dev(dev, event, force))
1170 		fib_flush(dev_net(dev));
1171 	else
1172 		rt_cache_flush(dev_net(dev));
1173 	arp_ifdown(dev);
1174 }
1175 
1176 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1177 {
1178 	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1179 	struct net_device *dev = ifa->ifa_dev->dev;
1180 	struct net *net = dev_net(dev);
1181 
1182 	switch (event) {
1183 	case NETDEV_UP:
1184 		fib_add_ifaddr(ifa);
1185 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1186 		fib_sync_up(dev, RTNH_F_DEAD);
1187 #endif
1188 		atomic_inc(&net->ipv4.dev_addr_genid);
1189 		rt_cache_flush(dev_net(dev));
1190 		break;
1191 	case NETDEV_DOWN:
1192 		fib_del_ifaddr(ifa, NULL);
1193 		atomic_inc(&net->ipv4.dev_addr_genid);
1194 		if (!ifa->ifa_dev->ifa_list) {
1195 			/* Last address was deleted from this interface.
1196 			 * Disable IP.
1197 			 */
1198 			fib_disable_ip(dev, event, true);
1199 		} else {
1200 			rt_cache_flush(dev_net(dev));
1201 		}
1202 		break;
1203 	}
1204 	return NOTIFY_DONE;
1205 }
1206 
1207 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1208 {
1209 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1210 	struct netdev_notifier_changeupper_info *info;
1211 	struct in_device *in_dev;
1212 	struct net *net = dev_net(dev);
1213 	unsigned int flags;
1214 
1215 	if (event == NETDEV_UNREGISTER) {
1216 		fib_disable_ip(dev, event, true);
1217 		rt_flush_dev(dev);
1218 		return NOTIFY_DONE;
1219 	}
1220 
1221 	in_dev = __in_dev_get_rtnl(dev);
1222 	if (!in_dev)
1223 		return NOTIFY_DONE;
1224 
1225 	switch (event) {
1226 	case NETDEV_UP:
1227 		for_ifa(in_dev) {
1228 			fib_add_ifaddr(ifa);
1229 		} endfor_ifa(in_dev);
1230 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1231 		fib_sync_up(dev, RTNH_F_DEAD);
1232 #endif
1233 		atomic_inc(&net->ipv4.dev_addr_genid);
1234 		rt_cache_flush(net);
1235 		break;
1236 	case NETDEV_DOWN:
1237 		fib_disable_ip(dev, event, false);
1238 		break;
1239 	case NETDEV_CHANGE:
1240 		flags = dev_get_flags(dev);
1241 		if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1242 			fib_sync_up(dev, RTNH_F_LINKDOWN);
1243 		else
1244 			fib_sync_down_dev(dev, event, false);
1245 		/* fall through */
1246 	case NETDEV_CHANGEMTU:
1247 		rt_cache_flush(net);
1248 		break;
1249 	case NETDEV_CHANGEUPPER:
1250 		info = ptr;
1251 		/* flush all routes if dev is linked to or unlinked from
1252 		 * an L3 master device (e.g., VRF)
1253 		 */
1254 		if (info->upper_dev && netif_is_l3_master(info->upper_dev))
1255 			fib_disable_ip(dev, NETDEV_DOWN, true);
1256 		break;
1257 	}
1258 	return NOTIFY_DONE;
1259 }
1260 
1261 static struct notifier_block fib_inetaddr_notifier = {
1262 	.notifier_call = fib_inetaddr_event,
1263 };
1264 
1265 static struct notifier_block fib_netdev_notifier = {
1266 	.notifier_call = fib_netdev_event,
1267 };
1268 
1269 static int __net_init ip_fib_net_init(struct net *net)
1270 {
1271 	int err;
1272 	size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1273 
1274 	err = fib4_notifier_init(net);
1275 	if (err)
1276 		return err;
1277 
1278 	/* Avoid false sharing : Use at least a full cache line */
1279 	size = max_t(size_t, size, L1_CACHE_BYTES);
1280 
1281 	net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1282 	if (!net->ipv4.fib_table_hash) {
1283 		err = -ENOMEM;
1284 		goto err_table_hash_alloc;
1285 	}
1286 
1287 	err = fib4_rules_init(net);
1288 	if (err < 0)
1289 		goto err_rules_init;
1290 	return 0;
1291 
1292 err_rules_init:
1293 	kfree(net->ipv4.fib_table_hash);
1294 err_table_hash_alloc:
1295 	fib4_notifier_exit(net);
1296 	return err;
1297 }
1298 
1299 static void ip_fib_net_exit(struct net *net)
1300 {
1301 	unsigned int i;
1302 
1303 	rtnl_lock();
1304 #ifdef CONFIG_IP_MULTIPLE_TABLES
1305 	RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1306 	RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1307 #endif
1308 	for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1309 		struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1310 		struct hlist_node *tmp;
1311 		struct fib_table *tb;
1312 
1313 		hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1314 			hlist_del(&tb->tb_hlist);
1315 			fib_table_flush(net, tb);
1316 			fib_free_table(tb);
1317 		}
1318 	}
1319 
1320 #ifdef CONFIG_IP_MULTIPLE_TABLES
1321 	fib4_rules_exit(net);
1322 #endif
1323 	rtnl_unlock();
1324 	kfree(net->ipv4.fib_table_hash);
1325 	fib4_notifier_exit(net);
1326 }
1327 
1328 static int __net_init fib_net_init(struct net *net)
1329 {
1330 	int error;
1331 
1332 #ifdef CONFIG_IP_ROUTE_CLASSID
1333 	net->ipv4.fib_num_tclassid_users = 0;
1334 #endif
1335 	error = ip_fib_net_init(net);
1336 	if (error < 0)
1337 		goto out;
1338 	error = nl_fib_lookup_init(net);
1339 	if (error < 0)
1340 		goto out_nlfl;
1341 	error = fib_proc_init(net);
1342 	if (error < 0)
1343 		goto out_proc;
1344 out:
1345 	return error;
1346 
1347 out_proc:
1348 	nl_fib_lookup_exit(net);
1349 out_nlfl:
1350 	ip_fib_net_exit(net);
1351 	goto out;
1352 }
1353 
1354 static void __net_exit fib_net_exit(struct net *net)
1355 {
1356 	fib_proc_exit(net);
1357 	nl_fib_lookup_exit(net);
1358 	ip_fib_net_exit(net);
1359 }
1360 
1361 static struct pernet_operations fib_net_ops = {
1362 	.init = fib_net_init,
1363 	.exit = fib_net_exit,
1364 };
1365 
1366 void __init ip_fib_init(void)
1367 {
1368 	fib_trie_init();
1369 
1370 	register_pernet_subsys(&fib_net_ops);
1371 
1372 	register_netdevice_notifier(&fib_netdev_notifier);
1373 	register_inetaddr_notifier(&fib_inetaddr_notifier);
1374 
1375 	rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0);
1376 	rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0);
1377 	rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0);
1378 }
1379