devinet_ioctl(): take copyin/copyout to caller
[muen/linux.git] / net / ipv4 / fib_frontend.c
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         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         /* Destroy the tables in reverse order to guarantee that the
1309          * local table, ID 255, is destroyed before the main table, ID
1310          * 254. This is necessary as the local table may contain
1311          * references to data contained in the main table.
1312          */
1313         for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1314                 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1315                 struct hlist_node *tmp;
1316                 struct fib_table *tb;
1317
1318                 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1319                         hlist_del(&tb->tb_hlist);
1320                         fib_table_flush(net, tb);
1321                         fib_free_table(tb);
1322                 }
1323         }
1324
1325 #ifdef CONFIG_IP_MULTIPLE_TABLES
1326         fib4_rules_exit(net);
1327 #endif
1328         rtnl_unlock();
1329         kfree(net->ipv4.fib_table_hash);
1330         fib4_notifier_exit(net);
1331 }
1332
1333 static int __net_init fib_net_init(struct net *net)
1334 {
1335         int error;
1336
1337 #ifdef CONFIG_IP_ROUTE_CLASSID
1338         net->ipv4.fib_num_tclassid_users = 0;
1339 #endif
1340         error = ip_fib_net_init(net);
1341         if (error < 0)
1342                 goto out;
1343         error = nl_fib_lookup_init(net);
1344         if (error < 0)
1345                 goto out_nlfl;
1346         error = fib_proc_init(net);
1347         if (error < 0)
1348                 goto out_proc;
1349 out:
1350         return error;
1351
1352 out_proc:
1353         nl_fib_lookup_exit(net);
1354 out_nlfl:
1355         ip_fib_net_exit(net);
1356         goto out;
1357 }
1358
1359 static void __net_exit fib_net_exit(struct net *net)
1360 {
1361         fib_proc_exit(net);
1362         nl_fib_lookup_exit(net);
1363         ip_fib_net_exit(net);
1364 }
1365
1366 static struct pernet_operations fib_net_ops = {
1367         .init = fib_net_init,
1368         .exit = fib_net_exit,
1369 };
1370
1371 void __init ip_fib_init(void)
1372 {
1373         fib_trie_init();
1374
1375         register_pernet_subsys(&fib_net_ops);
1376
1377         register_netdevice_notifier(&fib_netdev_notifier);
1378         register_inetaddr_notifier(&fib_inetaddr_notifier);
1379
1380         rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0);
1381         rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0);
1382         rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0);
1383 }