ip_rt_ioctl(): take copyin 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, struct rtentry *rt)
591 {
592         struct fib_config cfg;
593         int err;
594
595         switch (cmd) {
596         case SIOCADDRT:         /* Add a route */
597         case SIOCDELRT:         /* Delete a route */
598                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
599                         return -EPERM;
600
601                 rtnl_lock();
602                 err = rtentry_to_fib_config(net, cmd, rt, &cfg);
603                 if (err == 0) {
604                         struct fib_table *tb;
605
606                         if (cmd == SIOCDELRT) {
607                                 tb = fib_get_table(net, cfg.fc_table);
608                                 if (tb)
609                                         err = fib_table_delete(net, tb, &cfg,
610                                                                NULL);
611                                 else
612                                         err = -ESRCH;
613                         } else {
614                                 tb = fib_new_table(net, cfg.fc_table);
615                                 if (tb)
616                                         err = fib_table_insert(net, tb,
617                                                                &cfg, NULL);
618                                 else
619                                         err = -ENOBUFS;
620                         }
621
622                         /* allocated by rtentry_to_fib_config() */
623                         kfree(cfg.fc_mx);
624                 }
625                 rtnl_unlock();
626                 return err;
627         }
628         return -EINVAL;
629 }
630
631 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
632         [RTA_DST]               = { .type = NLA_U32 },
633         [RTA_SRC]               = { .type = NLA_U32 },
634         [RTA_IIF]               = { .type = NLA_U32 },
635         [RTA_OIF]               = { .type = NLA_U32 },
636         [RTA_GATEWAY]           = { .type = NLA_U32 },
637         [RTA_PRIORITY]          = { .type = NLA_U32 },
638         [RTA_PREFSRC]           = { .type = NLA_U32 },
639         [RTA_METRICS]           = { .type = NLA_NESTED },
640         [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
641         [RTA_FLOW]              = { .type = NLA_U32 },
642         [RTA_ENCAP_TYPE]        = { .type = NLA_U16 },
643         [RTA_ENCAP]             = { .type = NLA_NESTED },
644         [RTA_UID]               = { .type = NLA_U32 },
645         [RTA_MARK]              = { .type = NLA_U32 },
646 };
647
648 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
649                              struct nlmsghdr *nlh, struct fib_config *cfg,
650                              struct netlink_ext_ack *extack)
651 {
652         struct nlattr *attr;
653         int err, remaining;
654         struct rtmsg *rtm;
655
656         err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy,
657                              extack);
658         if (err < 0)
659                 goto errout;
660
661         memset(cfg, 0, sizeof(*cfg));
662
663         rtm = nlmsg_data(nlh);
664         cfg->fc_dst_len = rtm->rtm_dst_len;
665         cfg->fc_tos = rtm->rtm_tos;
666         cfg->fc_table = rtm->rtm_table;
667         cfg->fc_protocol = rtm->rtm_protocol;
668         cfg->fc_scope = rtm->rtm_scope;
669         cfg->fc_type = rtm->rtm_type;
670         cfg->fc_flags = rtm->rtm_flags;
671         cfg->fc_nlflags = nlh->nlmsg_flags;
672
673         cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
674         cfg->fc_nlinfo.nlh = nlh;
675         cfg->fc_nlinfo.nl_net = net;
676
677         if (cfg->fc_type > RTN_MAX) {
678                 NL_SET_ERR_MSG(extack, "Invalid route type");
679                 err = -EINVAL;
680                 goto errout;
681         }
682
683         nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
684                 switch (nla_type(attr)) {
685                 case RTA_DST:
686                         cfg->fc_dst = nla_get_be32(attr);
687                         break;
688                 case RTA_OIF:
689                         cfg->fc_oif = nla_get_u32(attr);
690                         break;
691                 case RTA_GATEWAY:
692                         cfg->fc_gw = nla_get_be32(attr);
693                         break;
694                 case RTA_PRIORITY:
695                         cfg->fc_priority = nla_get_u32(attr);
696                         break;
697                 case RTA_PREFSRC:
698                         cfg->fc_prefsrc = nla_get_be32(attr);
699                         break;
700                 case RTA_METRICS:
701                         cfg->fc_mx = nla_data(attr);
702                         cfg->fc_mx_len = nla_len(attr);
703                         break;
704                 case RTA_MULTIPATH:
705                         err = lwtunnel_valid_encap_type_attr(nla_data(attr),
706                                                              nla_len(attr),
707                                                              extack);
708                         if (err < 0)
709                                 goto errout;
710                         cfg->fc_mp = nla_data(attr);
711                         cfg->fc_mp_len = nla_len(attr);
712                         break;
713                 case RTA_FLOW:
714                         cfg->fc_flow = nla_get_u32(attr);
715                         break;
716                 case RTA_TABLE:
717                         cfg->fc_table = nla_get_u32(attr);
718                         break;
719                 case RTA_ENCAP:
720                         cfg->fc_encap = attr;
721                         break;
722                 case RTA_ENCAP_TYPE:
723                         cfg->fc_encap_type = nla_get_u16(attr);
724                         err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
725                                                         extack);
726                         if (err < 0)
727                                 goto errout;
728                         break;
729                 }
730         }
731
732         return 0;
733 errout:
734         return err;
735 }
736
737 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
738                              struct netlink_ext_ack *extack)
739 {
740         struct net *net = sock_net(skb->sk);
741         struct fib_config cfg;
742         struct fib_table *tb;
743         int err;
744
745         err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
746         if (err < 0)
747                 goto errout;
748
749         tb = fib_get_table(net, cfg.fc_table);
750         if (!tb) {
751                 NL_SET_ERR_MSG(extack, "FIB table does not exist");
752                 err = -ESRCH;
753                 goto errout;
754         }
755
756         err = fib_table_delete(net, tb, &cfg, extack);
757 errout:
758         return err;
759 }
760
761 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
762                              struct netlink_ext_ack *extack)
763 {
764         struct net *net = sock_net(skb->sk);
765         struct fib_config cfg;
766         struct fib_table *tb;
767         int err;
768
769         err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
770         if (err < 0)
771                 goto errout;
772
773         tb = fib_new_table(net, cfg.fc_table);
774         if (!tb) {
775                 err = -ENOBUFS;
776                 goto errout;
777         }
778
779         err = fib_table_insert(net, tb, &cfg, extack);
780         if (!err && cfg.fc_type == RTN_LOCAL)
781                 net->ipv4.fib_has_custom_local_routes = true;
782 errout:
783         return err;
784 }
785
786 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
787 {
788         struct net *net = sock_net(skb->sk);
789         unsigned int h, s_h;
790         unsigned int e = 0, s_e;
791         struct fib_table *tb;
792         struct hlist_head *head;
793         int dumped = 0, err;
794
795         if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
796             ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
797                 return skb->len;
798
799         s_h = cb->args[0];
800         s_e = cb->args[1];
801
802         rcu_read_lock();
803
804         for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
805                 e = 0;
806                 head = &net->ipv4.fib_table_hash[h];
807                 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
808                         if (e < s_e)
809                                 goto next;
810                         if (dumped)
811                                 memset(&cb->args[2], 0, sizeof(cb->args) -
812                                                  2 * sizeof(cb->args[0]));
813                         err = fib_table_dump(tb, skb, cb);
814                         if (err < 0) {
815                                 if (likely(skb->len))
816                                         goto out;
817
818                                 goto out_err;
819                         }
820                         dumped = 1;
821 next:
822                         e++;
823                 }
824         }
825 out:
826         err = skb->len;
827 out_err:
828         rcu_read_unlock();
829
830         cb->args[1] = e;
831         cb->args[0] = h;
832
833         return err;
834 }
835
836 /* Prepare and feed intra-kernel routing request.
837  * Really, it should be netlink message, but :-( netlink
838  * can be not configured, so that we feed it directly
839  * to fib engine. It is legal, because all events occur
840  * only when netlink is already locked.
841  */
842 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
843 {
844         struct net *net = dev_net(ifa->ifa_dev->dev);
845         u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
846         struct fib_table *tb;
847         struct fib_config cfg = {
848                 .fc_protocol = RTPROT_KERNEL,
849                 .fc_type = type,
850                 .fc_dst = dst,
851                 .fc_dst_len = dst_len,
852                 .fc_prefsrc = ifa->ifa_local,
853                 .fc_oif = ifa->ifa_dev->dev->ifindex,
854                 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
855                 .fc_nlinfo = {
856                         .nl_net = net,
857                 },
858         };
859
860         if (!tb_id)
861                 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
862
863         tb = fib_new_table(net, tb_id);
864         if (!tb)
865                 return;
866
867         cfg.fc_table = tb->tb_id;
868
869         if (type != RTN_LOCAL)
870                 cfg.fc_scope = RT_SCOPE_LINK;
871         else
872                 cfg.fc_scope = RT_SCOPE_HOST;
873
874         if (cmd == RTM_NEWROUTE)
875                 fib_table_insert(net, tb, &cfg, NULL);
876         else
877                 fib_table_delete(net, tb, &cfg, NULL);
878 }
879
880 void fib_add_ifaddr(struct in_ifaddr *ifa)
881 {
882         struct in_device *in_dev = ifa->ifa_dev;
883         struct net_device *dev = in_dev->dev;
884         struct in_ifaddr *prim = ifa;
885         __be32 mask = ifa->ifa_mask;
886         __be32 addr = ifa->ifa_local;
887         __be32 prefix = ifa->ifa_address & mask;
888
889         if (ifa->ifa_flags & IFA_F_SECONDARY) {
890                 prim = inet_ifa_byprefix(in_dev, prefix, mask);
891                 if (!prim) {
892                         pr_warn("%s: bug: prim == NULL\n", __func__);
893                         return;
894                 }
895         }
896
897         fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
898
899         if (!(dev->flags & IFF_UP))
900                 return;
901
902         /* Add broadcast address, if it is explicitly assigned. */
903         if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
904                 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
905
906         if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
907             (prefix != addr || ifa->ifa_prefixlen < 32)) {
908                 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
909                         fib_magic(RTM_NEWROUTE,
910                                   dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
911                                   prefix, ifa->ifa_prefixlen, prim);
912
913                 /* Add network specific broadcasts, when it takes a sense */
914                 if (ifa->ifa_prefixlen < 31) {
915                         fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
916                         fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
917                                   32, prim);
918                 }
919         }
920 }
921
922 /* Delete primary or secondary address.
923  * Optionally, on secondary address promotion consider the addresses
924  * from subnet iprim as deleted, even if they are in device list.
925  * In this case the secondary ifa can be in device list.
926  */
927 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
928 {
929         struct in_device *in_dev = ifa->ifa_dev;
930         struct net_device *dev = in_dev->dev;
931         struct in_ifaddr *ifa1;
932         struct in_ifaddr *prim = ifa, *prim1 = NULL;
933         __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
934         __be32 any = ifa->ifa_address & ifa->ifa_mask;
935 #define LOCAL_OK        1
936 #define BRD_OK          2
937 #define BRD0_OK         4
938 #define BRD1_OK         8
939         unsigned int ok = 0;
940         int subnet = 0;         /* Primary network */
941         int gone = 1;           /* Address is missing */
942         int same_prefsrc = 0;   /* Another primary with same IP */
943
944         if (ifa->ifa_flags & IFA_F_SECONDARY) {
945                 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
946                 if (!prim) {
947                         /* if the device has been deleted, we don't perform
948                          * address promotion
949                          */
950                         if (!in_dev->dead)
951                                 pr_warn("%s: bug: prim == NULL\n", __func__);
952                         return;
953                 }
954                 if (iprim && iprim != prim) {
955                         pr_warn("%s: bug: iprim != prim\n", __func__);
956                         return;
957                 }
958         } else if (!ipv4_is_zeronet(any) &&
959                    (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
960                 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
961                         fib_magic(RTM_DELROUTE,
962                                   dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
963                                   any, ifa->ifa_prefixlen, prim);
964                 subnet = 1;
965         }
966
967         if (in_dev->dead)
968                 goto no_promotions;
969
970         /* Deletion is more complicated than add.
971          * We should take care of not to delete too much :-)
972          *
973          * Scan address list to be sure that addresses are really gone.
974          */
975
976         for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
977                 if (ifa1 == ifa) {
978                         /* promotion, keep the IP */
979                         gone = 0;
980                         continue;
981                 }
982                 /* Ignore IFAs from our subnet */
983                 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
984                     inet_ifa_match(ifa1->ifa_address, iprim))
985                         continue;
986
987                 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
988                 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
989                         /* Another address from our subnet? */
990                         if (ifa1->ifa_mask == prim->ifa_mask &&
991                             inet_ifa_match(ifa1->ifa_address, prim))
992                                 prim1 = prim;
993                         else {
994                                 /* We reached the secondaries, so
995                                  * same_prefsrc should be determined.
996                                  */
997                                 if (!same_prefsrc)
998                                         continue;
999                                 /* Search new prim1 if ifa1 is not
1000                                  * using the current prim1
1001                                  */
1002                                 if (!prim1 ||
1003                                     ifa1->ifa_mask != prim1->ifa_mask ||
1004                                     !inet_ifa_match(ifa1->ifa_address, prim1))
1005                                         prim1 = inet_ifa_byprefix(in_dev,
1006                                                         ifa1->ifa_address,
1007                                                         ifa1->ifa_mask);
1008                                 if (!prim1)
1009                                         continue;
1010                                 if (prim1->ifa_local != prim->ifa_local)
1011                                         continue;
1012                         }
1013                 } else {
1014                         if (prim->ifa_local != ifa1->ifa_local)
1015                                 continue;
1016                         prim1 = ifa1;
1017                         if (prim != prim1)
1018                                 same_prefsrc = 1;
1019                 }
1020                 if (ifa->ifa_local == ifa1->ifa_local)
1021                         ok |= LOCAL_OK;
1022                 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1023                         ok |= BRD_OK;
1024                 if (brd == ifa1->ifa_broadcast)
1025                         ok |= BRD1_OK;
1026                 if (any == ifa1->ifa_broadcast)
1027                         ok |= BRD0_OK;
1028                 /* primary has network specific broadcasts */
1029                 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1030                         __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1031                         __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1032
1033                         if (!ipv4_is_zeronet(any1)) {
1034                                 if (ifa->ifa_broadcast == brd1 ||
1035                                     ifa->ifa_broadcast == any1)
1036                                         ok |= BRD_OK;
1037                                 if (brd == brd1 || brd == any1)
1038                                         ok |= BRD1_OK;
1039                                 if (any == brd1 || any == any1)
1040                                         ok |= BRD0_OK;
1041                         }
1042                 }
1043         }
1044
1045 no_promotions:
1046         if (!(ok & BRD_OK))
1047                 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
1048         if (subnet && ifa->ifa_prefixlen < 31) {
1049                 if (!(ok & BRD1_OK))
1050                         fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
1051                 if (!(ok & BRD0_OK))
1052                         fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
1053         }
1054         if (!(ok & LOCAL_OK)) {
1055                 unsigned int addr_type;
1056
1057                 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
1058
1059                 /* Check, that this local address finally disappeared. */
1060                 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1061                                                      ifa->ifa_local);
1062                 if (gone && addr_type != RTN_LOCAL) {
1063                         /* And the last, but not the least thing.
1064                          * We must flush stray FIB entries.
1065                          *
1066                          * First of all, we scan fib_info list searching
1067                          * for stray nexthop entries, then ignite fib_flush.
1068                          */
1069                         if (fib_sync_down_addr(dev, ifa->ifa_local))
1070                                 fib_flush(dev_net(dev));
1071                 }
1072         }
1073 #undef LOCAL_OK
1074 #undef BRD_OK
1075 #undef BRD0_OK
1076 #undef BRD1_OK
1077 }
1078
1079 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1080 {
1081
1082         struct fib_result       res;
1083         struct flowi4           fl4 = {
1084                 .flowi4_mark = frn->fl_mark,
1085                 .daddr = frn->fl_addr,
1086                 .flowi4_tos = frn->fl_tos,
1087                 .flowi4_scope = frn->fl_scope,
1088         };
1089         struct fib_table *tb;
1090
1091         rcu_read_lock();
1092
1093         tb = fib_get_table(net, frn->tb_id_in);
1094
1095         frn->err = -ENOENT;
1096         if (tb) {
1097                 local_bh_disable();
1098
1099                 frn->tb_id = tb->tb_id;
1100                 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1101
1102                 if (!frn->err) {
1103                         frn->prefixlen = res.prefixlen;
1104                         frn->nh_sel = res.nh_sel;
1105                         frn->type = res.type;
1106                         frn->scope = res.scope;
1107                 }
1108                 local_bh_enable();
1109         }
1110
1111         rcu_read_unlock();
1112 }
1113
1114 static void nl_fib_input(struct sk_buff *skb)
1115 {
1116         struct net *net;
1117         struct fib_result_nl *frn;
1118         struct nlmsghdr *nlh;
1119         u32 portid;
1120
1121         net = sock_net(skb->sk);
1122         nlh = nlmsg_hdr(skb);
1123         if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1124             skb->len < nlh->nlmsg_len ||
1125             nlmsg_len(nlh) < sizeof(*frn))
1126                 return;
1127
1128         skb = netlink_skb_clone(skb, GFP_KERNEL);
1129         if (!skb)
1130                 return;
1131         nlh = nlmsg_hdr(skb);
1132
1133         frn = (struct fib_result_nl *) nlmsg_data(nlh);
1134         nl_fib_lookup(net, frn);
1135
1136         portid = NETLINK_CB(skb).portid;      /* netlink portid */
1137         NETLINK_CB(skb).portid = 0;        /* from kernel */
1138         NETLINK_CB(skb).dst_group = 0;  /* unicast */
1139         netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1140 }
1141
1142 static int __net_init nl_fib_lookup_init(struct net *net)
1143 {
1144         struct sock *sk;
1145         struct netlink_kernel_cfg cfg = {
1146                 .input  = nl_fib_input,
1147         };
1148
1149         sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1150         if (!sk)
1151                 return -EAFNOSUPPORT;
1152         net->ipv4.fibnl = sk;
1153         return 0;
1154 }
1155
1156 static void nl_fib_lookup_exit(struct net *net)
1157 {
1158         netlink_kernel_release(net->ipv4.fibnl);
1159         net->ipv4.fibnl = NULL;
1160 }
1161
1162 static void fib_disable_ip(struct net_device *dev, unsigned long event,
1163                            bool force)
1164 {
1165         if (fib_sync_down_dev(dev, event, force))
1166                 fib_flush(dev_net(dev));
1167         else
1168                 rt_cache_flush(dev_net(dev));
1169         arp_ifdown(dev);
1170 }
1171
1172 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1173 {
1174         struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1175         struct net_device *dev = ifa->ifa_dev->dev;
1176         struct net *net = dev_net(dev);
1177
1178         switch (event) {
1179         case NETDEV_UP:
1180                 fib_add_ifaddr(ifa);
1181 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1182                 fib_sync_up(dev, RTNH_F_DEAD);
1183 #endif
1184                 atomic_inc(&net->ipv4.dev_addr_genid);
1185                 rt_cache_flush(dev_net(dev));
1186                 break;
1187         case NETDEV_DOWN:
1188                 fib_del_ifaddr(ifa, NULL);
1189                 atomic_inc(&net->ipv4.dev_addr_genid);
1190                 if (!ifa->ifa_dev->ifa_list) {
1191                         /* Last address was deleted from this interface.
1192                          * Disable IP.
1193                          */
1194                         fib_disable_ip(dev, event, true);
1195                 } else {
1196                         rt_cache_flush(dev_net(dev));
1197                 }
1198                 break;
1199         }
1200         return NOTIFY_DONE;
1201 }
1202
1203 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1204 {
1205         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1206         struct netdev_notifier_changeupper_info *info;
1207         struct in_device *in_dev;
1208         struct net *net = dev_net(dev);
1209         unsigned int flags;
1210
1211         if (event == NETDEV_UNREGISTER) {
1212                 fib_disable_ip(dev, event, true);
1213                 rt_flush_dev(dev);
1214                 return NOTIFY_DONE;
1215         }
1216
1217         in_dev = __in_dev_get_rtnl(dev);
1218         if (!in_dev)
1219                 return NOTIFY_DONE;
1220
1221         switch (event) {
1222         case NETDEV_UP:
1223                 for_ifa(in_dev) {
1224                         fib_add_ifaddr(ifa);
1225                 } endfor_ifa(in_dev);
1226 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1227                 fib_sync_up(dev, RTNH_F_DEAD);
1228 #endif
1229                 atomic_inc(&net->ipv4.dev_addr_genid);
1230                 rt_cache_flush(net);
1231                 break;
1232         case NETDEV_DOWN:
1233                 fib_disable_ip(dev, event, false);
1234                 break;
1235         case NETDEV_CHANGE:
1236                 flags = dev_get_flags(dev);
1237                 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1238                         fib_sync_up(dev, RTNH_F_LINKDOWN);
1239                 else
1240                         fib_sync_down_dev(dev, event, false);
1241                 /* fall through */
1242         case NETDEV_CHANGEMTU:
1243                 rt_cache_flush(net);
1244                 break;
1245         case NETDEV_CHANGEUPPER:
1246                 info = ptr;
1247                 /* flush all routes if dev is linked to or unlinked from
1248                  * an L3 master device (e.g., VRF)
1249                  */
1250                 if (info->upper_dev && netif_is_l3_master(info->upper_dev))
1251                         fib_disable_ip(dev, NETDEV_DOWN, true);
1252                 break;
1253         }
1254         return NOTIFY_DONE;
1255 }
1256
1257 static struct notifier_block fib_inetaddr_notifier = {
1258         .notifier_call = fib_inetaddr_event,
1259 };
1260
1261 static struct notifier_block fib_netdev_notifier = {
1262         .notifier_call = fib_netdev_event,
1263 };
1264
1265 static int __net_init ip_fib_net_init(struct net *net)
1266 {
1267         int err;
1268         size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1269
1270         err = fib4_notifier_init(net);
1271         if (err)
1272                 return err;
1273
1274         /* Avoid false sharing : Use at least a full cache line */
1275         size = max_t(size_t, size, L1_CACHE_BYTES);
1276
1277         net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1278         if (!net->ipv4.fib_table_hash) {
1279                 err = -ENOMEM;
1280                 goto err_table_hash_alloc;
1281         }
1282
1283         err = fib4_rules_init(net);
1284         if (err < 0)
1285                 goto err_rules_init;
1286         return 0;
1287
1288 err_rules_init:
1289         kfree(net->ipv4.fib_table_hash);
1290 err_table_hash_alloc:
1291         fib4_notifier_exit(net);
1292         return err;
1293 }
1294
1295 static void ip_fib_net_exit(struct net *net)
1296 {
1297         int i;
1298
1299         rtnl_lock();
1300 #ifdef CONFIG_IP_MULTIPLE_TABLES
1301         RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1302         RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1303 #endif
1304         /* Destroy the tables in reverse order to guarantee that the
1305          * local table, ID 255, is destroyed before the main table, ID
1306          * 254. This is necessary as the local table may contain
1307          * references to data contained in the main table.
1308          */
1309         for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1310                 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1311                 struct hlist_node *tmp;
1312                 struct fib_table *tb;
1313
1314                 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1315                         hlist_del(&tb->tb_hlist);
1316                         fib_table_flush(net, tb);
1317                         fib_free_table(tb);
1318                 }
1319         }
1320
1321 #ifdef CONFIG_IP_MULTIPLE_TABLES
1322         fib4_rules_exit(net);
1323 #endif
1324         rtnl_unlock();
1325         kfree(net->ipv4.fib_table_hash);
1326         fib4_notifier_exit(net);
1327 }
1328
1329 static int __net_init fib_net_init(struct net *net)
1330 {
1331         int error;
1332
1333 #ifdef CONFIG_IP_ROUTE_CLASSID
1334         net->ipv4.fib_num_tclassid_users = 0;
1335 #endif
1336         error = ip_fib_net_init(net);
1337         if (error < 0)
1338                 goto out;
1339         error = nl_fib_lookup_init(net);
1340         if (error < 0)
1341                 goto out_nlfl;
1342         error = fib_proc_init(net);
1343         if (error < 0)
1344                 goto out_proc;
1345 out:
1346         return error;
1347
1348 out_proc:
1349         nl_fib_lookup_exit(net);
1350 out_nlfl:
1351         ip_fib_net_exit(net);
1352         goto out;
1353 }
1354
1355 static void __net_exit fib_net_exit(struct net *net)
1356 {
1357         fib_proc_exit(net);
1358         nl_fib_lookup_exit(net);
1359         ip_fib_net_exit(net);
1360 }
1361
1362 static struct pernet_operations fib_net_ops = {
1363         .init = fib_net_init,
1364         .exit = fib_net_exit,
1365 };
1366
1367 void __init ip_fib_init(void)
1368 {
1369         fib_trie_init();
1370
1371         register_pernet_subsys(&fib_net_ops);
1372
1373         register_netdevice_notifier(&fib_netdev_notifier);
1374         register_inetaddr_notifier(&fib_inetaddr_notifier);
1375
1376         rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0);
1377         rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0);
1378         rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0);
1379 }