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
54static 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
72fail:
73 fib_free_table(main_table);
74 return -ENOMEM;
75}
76
77static bool fib4_has_custom_rules(struct net *net)
78{
79 return false;
80}
81#else
82
83struct 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}
116EXPORT_SYMBOL_GPL(fib_new_table);
117
118/* caller must hold either rtnl or rcu read lock */
119struct 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
137static 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
143static 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
163int 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
195static 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, false);
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 */
217static 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
246unsigned 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}
250EXPORT_SYMBOL(inet_addr_type_table);
251
252unsigned int inet_addr_type(struct net *net, __be32 addr)
253{
254 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
255}
256EXPORT_SYMBOL(inet_addr_type);
257
258unsigned 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}
265EXPORT_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 */
270unsigned 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}
278EXPORT_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
296 net = dev_net(dev);
297
298 scope = RT_SCOPE_UNIVERSE;
299 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
300 bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev);
301 struct flowi4 fl4 = {
302 .flowi4_iif = LOOPBACK_IFINDEX,
303 .flowi4_oif = l3mdev_master_ifindex_rcu(dev),
304 .daddr = ip_hdr(skb)->saddr,
305 .flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
306 .flowi4_scope = scope,
307 .flowi4_mark = vmark ? skb->mark : 0,
308 };
309 if (!fib_lookup(net, &fl4, &res, 0))
310 return FIB_RES_PREFSRC(net, res);
311 } else {
312 scope = RT_SCOPE_LINK;
313 }
314
315 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
316}
317
318bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev)
319{
320 bool dev_match = false;
321#ifdef CONFIG_IP_ROUTE_MULTIPATH
322 int ret;
323
324 for (ret = 0; ret < fi->fib_nhs; ret++) {
325 struct fib_nh *nh = &fi->fib_nh[ret];
326
327 if (nh->nh_dev == dev) {
328 dev_match = true;
329 break;
330 } else if (l3mdev_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
331 dev_match = true;
332 break;
333 }
334 }
335#else
336 if (fi->fib_nh[0].nh_dev == dev)
337 dev_match = true;
338#endif
339
340 return dev_match;
341}
342EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev);
343
344/* Given (packet source, input interface) and optional (dst, oif, tos):
345 * - (main) check, that source is valid i.e. not broadcast or our local
346 * address.
347 * - figure out what "logical" interface this packet arrived
348 * and calculate "specific destination" address.
349 * - check, that packet arrived from expected physical interface.
350 * called with rcu_read_lock()
351 */
352static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
353 u8 tos, int oif, struct net_device *dev,
354 int rpf, struct in_device *idev, u32 *itag)
355{
356 struct net *net = dev_net(dev);
357 struct flow_keys flkeys;
358 int ret, no_addr;
359 struct fib_result res;
360 struct flowi4 fl4;
361 bool dev_match;
362
363 fl4.flowi4_oif = 0;
364 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
365 if (!fl4.flowi4_iif)
366 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
367 fl4.daddr = src;
368 fl4.saddr = dst;
369 fl4.flowi4_tos = tos;
370 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
371 fl4.flowi4_tun_key.tun_id = 0;
372 fl4.flowi4_flags = 0;
373 fl4.flowi4_uid = sock_net_uid(net, NULL);
374
375 no_addr = idev->ifa_list == NULL;
376
377 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
378 if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) {
379 fl4.flowi4_proto = 0;
380 fl4.fl4_sport = 0;
381 fl4.fl4_dport = 0;
382 }
383
384 if (fib_lookup(net, &fl4, &res, 0))
385 goto last_resort;
386 if (res.type != RTN_UNICAST &&
387 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
388 goto e_inval;
389 fib_combine_itag(itag, &res);
390
391 dev_match = fib_info_nh_uses_dev(res.fi, dev);
392 if (dev_match) {
393 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
394 return ret;
395 }
396 if (no_addr)
397 goto last_resort;
398 if (rpf == 1)
399 goto e_rpf;
400 fl4.flowi4_oif = dev->ifindex;
401
402 ret = 0;
403 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
404 if (res.type == RTN_UNICAST)
405 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
406 }
407 return ret;
408
409last_resort:
410 if (rpf)
411 goto e_rpf;
412 *itag = 0;
413 return 0;
414
415e_inval:
416 return -EINVAL;
417e_rpf:
418 return -EXDEV;
419}
420
421/* Ignore rp_filter for packets protected by IPsec. */
422int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
423 u8 tos, int oif, struct net_device *dev,
424 struct in_device *idev, u32 *itag)
425{
426 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
427 struct net *net = dev_net(dev);
428
429 if (!r && !fib_num_tclassid_users(net) &&
430 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
431 if (IN_DEV_ACCEPT_LOCAL(idev))
432 goto ok;
433 /* with custom local routes in place, checking local addresses
434 * only will be too optimistic, with custom rules, checking
435 * local addresses only can be too strict, e.g. due to vrf
436 */
437 if (net->ipv4.fib_has_custom_local_routes ||
438 fib4_has_custom_rules(net))
439 goto full_check;
440 if (inet_lookup_ifaddr_rcu(net, src))
441 return -EINVAL;
442
443ok:
444 *itag = 0;
445 return 0;
446 }
447
448full_check:
449 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
450}
451
452static inline __be32 sk_extract_addr(struct sockaddr *addr)
453{
454 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
455}
456
457static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
458{
459 struct nlattr *nla;
460
461 nla = (struct nlattr *) ((char *) mx + len);
462 nla->nla_type = type;
463 nla->nla_len = nla_attr_size(4);
464 *(u32 *) nla_data(nla) = value;
465
466 return len + nla_total_size(4);
467}
468
469static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
470 struct fib_config *cfg)
471{
472 __be32 addr;
473 int plen;
474
475 memset(cfg, 0, sizeof(*cfg));
476 cfg->fc_nlinfo.nl_net = net;
477
478 if (rt->rt_dst.sa_family != AF_INET)
479 return -EAFNOSUPPORT;
480
481 /*
482 * Check mask for validity:
483 * a) it must be contiguous.
484 * b) destination must have all host bits clear.
485 * c) if application forgot to set correct family (AF_INET),
486 * reject request unless it is absolutely clear i.e.
487 * both family and mask are zero.
488 */
489 plen = 32;
490 addr = sk_extract_addr(&rt->rt_dst);
491 if (!(rt->rt_flags & RTF_HOST)) {
492 __be32 mask = sk_extract_addr(&rt->rt_genmask);
493
494 if (rt->rt_genmask.sa_family != AF_INET) {
495 if (mask || rt->rt_genmask.sa_family)
496 return -EAFNOSUPPORT;
497 }
498
499 if (bad_mask(mask, addr))
500 return -EINVAL;
501
502 plen = inet_mask_len(mask);
503 }
504
505 cfg->fc_dst_len = plen;
506 cfg->fc_dst = addr;
507
508 if (cmd != SIOCDELRT) {
509 cfg->fc_nlflags = NLM_F_CREATE;
510 cfg->fc_protocol = RTPROT_BOOT;
511 }
512
513 if (rt->rt_metric)
514 cfg->fc_priority = rt->rt_metric - 1;
515
516 if (rt->rt_flags & RTF_REJECT) {
517 cfg->fc_scope = RT_SCOPE_HOST;
518 cfg->fc_type = RTN_UNREACHABLE;
519 return 0;
520 }
521
522 cfg->fc_scope = RT_SCOPE_NOWHERE;
523 cfg->fc_type = RTN_UNICAST;
524
525 if (rt->rt_dev) {
526 char *colon;
527 struct net_device *dev;
528 char devname[IFNAMSIZ];
529
530 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
531 return -EFAULT;
532
533 devname[IFNAMSIZ-1] = 0;
534 colon = strchr(devname, ':');
535 if (colon)
536 *colon = 0;
537 dev = __dev_get_by_name(net, devname);
538 if (!dev)
539 return -ENODEV;
540 cfg->fc_oif = dev->ifindex;
541 cfg->fc_table = l3mdev_fib_table(dev);
542 if (colon) {
543 struct in_ifaddr *ifa;
544 struct in_device *in_dev = __in_dev_get_rtnl(dev);
545 if (!in_dev)
546 return -ENODEV;
547 *colon = ':';
548 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
549 if (strcmp(ifa->ifa_label, devname) == 0)
550 break;
551 if (!ifa)
552 return -ENODEV;
553 cfg->fc_prefsrc = ifa->ifa_local;
554 }
555 }
556
557 addr = sk_extract_addr(&rt->rt_gateway);
558 if (rt->rt_gateway.sa_family == AF_INET && addr) {
559 unsigned int addr_type;
560
561 cfg->fc_gw = addr;
562 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
563 if (rt->rt_flags & RTF_GATEWAY &&
564 addr_type == RTN_UNICAST)
565 cfg->fc_scope = RT_SCOPE_UNIVERSE;
566 }
567
568 if (cmd == SIOCDELRT)
569 return 0;
570
571 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
572 return -EINVAL;
573
574 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
575 cfg->fc_scope = RT_SCOPE_LINK;
576
577 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
578 struct nlattr *mx;
579 int len = 0;
580
581 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL);
582 if (!mx)
583 return -ENOMEM;
584
585 if (rt->rt_flags & RTF_MTU)
586 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
587
588 if (rt->rt_flags & RTF_WINDOW)
589 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
590
591 if (rt->rt_flags & RTF_IRTT)
592 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
593
594 cfg->fc_mx = mx;
595 cfg->fc_mx_len = len;
596 }
597
598 return 0;
599}
600
601/*
602 * Handle IP routing ioctl calls.
603 * These are used to manipulate the routing tables
604 */
605int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
606{
607 struct fib_config cfg;
608 int err;
609
610 switch (cmd) {
611 case SIOCADDRT: /* Add a route */
612 case SIOCDELRT: /* Delete a route */
613 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
614 return -EPERM;
615
616 rtnl_lock();
617 err = rtentry_to_fib_config(net, cmd, rt, &cfg);
618 if (err == 0) {
619 struct fib_table *tb;
620
621 if (cmd == SIOCDELRT) {
622 tb = fib_get_table(net, cfg.fc_table);
623 if (tb)
624 err = fib_table_delete(net, tb, &cfg,
625 NULL);
626 else
627 err = -ESRCH;
628 } else {
629 tb = fib_new_table(net, cfg.fc_table);
630 if (tb)
631 err = fib_table_insert(net, tb,
632 &cfg, NULL);
633 else
634 err = -ENOBUFS;
635 }
636
637 /* allocated by rtentry_to_fib_config() */
638 kfree(cfg.fc_mx);
639 }
640 rtnl_unlock();
641 return err;
642 }
643 return -EINVAL;
644}
645
646const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
647 [RTA_DST] = { .type = NLA_U32 },
648 [RTA_SRC] = { .type = NLA_U32 },
649 [RTA_IIF] = { .type = NLA_U32 },
650 [RTA_OIF] = { .type = NLA_U32 },
651 [RTA_GATEWAY] = { .type = NLA_U32 },
652 [RTA_PRIORITY] = { .type = NLA_U32 },
653 [RTA_PREFSRC] = { .type = NLA_U32 },
654 [RTA_METRICS] = { .type = NLA_NESTED },
655 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
656 [RTA_FLOW] = { .type = NLA_U32 },
657 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
658 [RTA_ENCAP] = { .type = NLA_NESTED },
659 [RTA_UID] = { .type = NLA_U32 },
660 [RTA_MARK] = { .type = NLA_U32 },
661 [RTA_TABLE] = { .type = NLA_U32 },
662 [RTA_IP_PROTO] = { .type = NLA_U8 },
663 [RTA_SPORT] = { .type = NLA_U16 },
664 [RTA_DPORT] = { .type = NLA_U16 },
665};
666
667static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
668 struct nlmsghdr *nlh, struct fib_config *cfg,
669 struct netlink_ext_ack *extack)
670{
671 struct nlattr *attr;
672 int err, remaining;
673 struct rtmsg *rtm;
674
675 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy,
676 extack);
677 if (err < 0)
678 goto errout;
679
680 memset(cfg, 0, sizeof(*cfg));
681
682 rtm = nlmsg_data(nlh);
683 cfg->fc_dst_len = rtm->rtm_dst_len;
684 cfg->fc_tos = rtm->rtm_tos;
685 cfg->fc_table = rtm->rtm_table;
686 cfg->fc_protocol = rtm->rtm_protocol;
687 cfg->fc_scope = rtm->rtm_scope;
688 cfg->fc_type = rtm->rtm_type;
689 cfg->fc_flags = rtm->rtm_flags;
690 cfg->fc_nlflags = nlh->nlmsg_flags;
691
692 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
693 cfg->fc_nlinfo.nlh = nlh;
694 cfg->fc_nlinfo.nl_net = net;
695
696 if (cfg->fc_type > RTN_MAX) {
697 NL_SET_ERR_MSG(extack, "Invalid route type");
698 err = -EINVAL;
699 goto errout;
700 }
701
702 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
703 switch (nla_type(attr)) {
704 case RTA_DST:
705 cfg->fc_dst = nla_get_be32(attr);
706 break;
707 case RTA_OIF:
708 cfg->fc_oif = nla_get_u32(attr);
709 break;
710 case RTA_GATEWAY:
711 cfg->fc_gw = nla_get_be32(attr);
712 break;
713 case RTA_VIA:
714 NL_SET_ERR_MSG(extack, "IPv4 does not support RTA_VIA attribute");
715 err = -EINVAL;
716 goto errout;
717 case RTA_PRIORITY:
718 cfg->fc_priority = nla_get_u32(attr);
719 break;
720 case RTA_PREFSRC:
721 cfg->fc_prefsrc = nla_get_be32(attr);
722 break;
723 case RTA_METRICS:
724 cfg->fc_mx = nla_data(attr);
725 cfg->fc_mx_len = nla_len(attr);
726 break;
727 case RTA_MULTIPATH:
728 err = lwtunnel_valid_encap_type_attr(nla_data(attr),
729 nla_len(attr),
730 extack);
731 if (err < 0)
732 goto errout;
733 cfg->fc_mp = nla_data(attr);
734 cfg->fc_mp_len = nla_len(attr);
735 break;
736 case RTA_FLOW:
737 cfg->fc_flow = nla_get_u32(attr);
738 break;
739 case RTA_TABLE:
740 cfg->fc_table = nla_get_u32(attr);
741 break;
742 case RTA_ENCAP:
743 cfg->fc_encap = attr;
744 break;
745 case RTA_ENCAP_TYPE:
746 cfg->fc_encap_type = nla_get_u16(attr);
747 err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
748 extack);
749 if (err < 0)
750 goto errout;
751 break;
752 }
753 }
754
755 return 0;
756errout:
757 return err;
758}
759
760static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
761 struct netlink_ext_ack *extack)
762{
763 struct net *net = sock_net(skb->sk);
764 struct fib_config cfg;
765 struct fib_table *tb;
766 int err;
767
768 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
769 if (err < 0)
770 goto errout;
771
772 tb = fib_get_table(net, cfg.fc_table);
773 if (!tb) {
774 NL_SET_ERR_MSG(extack, "FIB table does not exist");
775 err = -ESRCH;
776 goto errout;
777 }
778
779 err = fib_table_delete(net, tb, &cfg, extack);
780errout:
781 return err;
782}
783
784static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
785 struct netlink_ext_ack *extack)
786{
787 struct net *net = sock_net(skb->sk);
788 struct fib_config cfg;
789 struct fib_table *tb;
790 int err;
791
792 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
793 if (err < 0)
794 goto errout;
795
796 tb = fib_new_table(net, cfg.fc_table);
797 if (!tb) {
798 err = -ENOBUFS;
799 goto errout;
800 }
801
802 err = fib_table_insert(net, tb, &cfg, extack);
803 if (!err && cfg.fc_type == RTN_LOCAL)
804 net->ipv4.fib_has_custom_local_routes = true;
805errout:
806 return err;
807}
808
809int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
810 struct fib_dump_filter *filter,
811 struct netlink_callback *cb)
812{
813 struct netlink_ext_ack *extack = cb->extack;
814 struct nlattr *tb[RTA_MAX + 1];
815 struct rtmsg *rtm;
816 int err, i;
817
818 ASSERT_RTNL();
819
820 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
821 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request");
822 return -EINVAL;
823 }
824
825 rtm = nlmsg_data(nlh);
826 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos ||
827 rtm->rtm_scope) {
828 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request");
829 return -EINVAL;
830 }
831 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) {
832 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request");
833 return -EINVAL;
834 }
835
836 filter->dump_all_families = (rtm->rtm_family == AF_UNSPEC);
837 filter->flags = rtm->rtm_flags;
838 filter->protocol = rtm->rtm_protocol;
839 filter->rt_type = rtm->rtm_type;
840 filter->table_id = rtm->rtm_table;
841
842 err = nlmsg_parse_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
843 rtm_ipv4_policy, extack);
844 if (err < 0)
845 return err;
846
847 for (i = 0; i <= RTA_MAX; ++i) {
848 int ifindex;
849
850 if (!tb[i])
851 continue;
852
853 switch (i) {
854 case RTA_TABLE:
855 filter->table_id = nla_get_u32(tb[i]);
856 break;
857 case RTA_OIF:
858 ifindex = nla_get_u32(tb[i]);
859 filter->dev = __dev_get_by_index(net, ifindex);
860 if (!filter->dev)
861 return -ENODEV;
862 break;
863 default:
864 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
865 return -EINVAL;
866 }
867 }
868
869 if (filter->flags || filter->protocol || filter->rt_type ||
870 filter->table_id || filter->dev) {
871 filter->filter_set = 1;
872 cb->answer_flags = NLM_F_DUMP_FILTERED;
873 }
874
875 return 0;
876}
877EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req);
878
879static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
880{
881 const struct nlmsghdr *nlh = cb->nlh;
882 struct net *net = sock_net(skb->sk);
883 struct fib_dump_filter filter = {};
884 unsigned int h, s_h;
885 unsigned int e = 0, s_e;
886 struct fib_table *tb;
887 struct hlist_head *head;
888 int dumped = 0, err;
889
890 if (cb->strict_check) {
891 err = ip_valid_fib_dump_req(net, nlh, &filter, cb);
892 if (err < 0)
893 return err;
894 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
895 struct rtmsg *rtm = nlmsg_data(nlh);
896
897 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED);
898 }
899
900 /* fib entries are never clones and ipv4 does not use prefix flag */
901 if (filter.flags & (RTM_F_PREFIX | RTM_F_CLONED))
902 return skb->len;
903
904 if (filter.table_id) {
905 tb = fib_get_table(net, filter.table_id);
906 if (!tb) {
907 if (filter.dump_all_families)
908 return skb->len;
909
910 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist");
911 return -ENOENT;
912 }
913
914 err = fib_table_dump(tb, skb, cb, &filter);
915 return skb->len ? : err;
916 }
917
918 s_h = cb->args[0];
919 s_e = cb->args[1];
920
921 rcu_read_lock();
922
923 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
924 e = 0;
925 head = &net->ipv4.fib_table_hash[h];
926 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
927 if (e < s_e)
928 goto next;
929 if (dumped)
930 memset(&cb->args[2], 0, sizeof(cb->args) -
931 2 * sizeof(cb->args[0]));
932 err = fib_table_dump(tb, skb, cb, &filter);
933 if (err < 0) {
934 if (likely(skb->len))
935 goto out;
936
937 goto out_err;
938 }
939 dumped = 1;
940next:
941 e++;
942 }
943 }
944out:
945 err = skb->len;
946out_err:
947 rcu_read_unlock();
948
949 cb->args[1] = e;
950 cb->args[0] = h;
951
952 return err;
953}
954
955/* Prepare and feed intra-kernel routing request.
956 * Really, it should be netlink message, but :-( netlink
957 * can be not configured, so that we feed it directly
958 * to fib engine. It is legal, because all events occur
959 * only when netlink is already locked.
960 */
961static void fib_magic(int cmd, int type, __be32 dst, int dst_len,
962 struct in_ifaddr *ifa, u32 rt_priority)
963{
964 struct net *net = dev_net(ifa->ifa_dev->dev);
965 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
966 struct fib_table *tb;
967 struct fib_config cfg = {
968 .fc_protocol = RTPROT_KERNEL,
969 .fc_type = type,
970 .fc_dst = dst,
971 .fc_dst_len = dst_len,
972 .fc_priority = rt_priority,
973 .fc_prefsrc = ifa->ifa_local,
974 .fc_oif = ifa->ifa_dev->dev->ifindex,
975 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
976 .fc_nlinfo = {
977 .nl_net = net,
978 },
979 };
980
981 if (!tb_id)
982 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
983
984 tb = fib_new_table(net, tb_id);
985 if (!tb)
986 return;
987
988 cfg.fc_table = tb->tb_id;
989
990 if (type != RTN_LOCAL)
991 cfg.fc_scope = RT_SCOPE_LINK;
992 else
993 cfg.fc_scope = RT_SCOPE_HOST;
994
995 if (cmd == RTM_NEWROUTE)
996 fib_table_insert(net, tb, &cfg, NULL);
997 else
998 fib_table_delete(net, tb, &cfg, NULL);
999}
1000
1001void fib_add_ifaddr(struct in_ifaddr *ifa)
1002{
1003 struct in_device *in_dev = ifa->ifa_dev;
1004 struct net_device *dev = in_dev->dev;
1005 struct in_ifaddr *prim = ifa;
1006 __be32 mask = ifa->ifa_mask;
1007 __be32 addr = ifa->ifa_local;
1008 __be32 prefix = ifa->ifa_address & mask;
1009
1010 if (ifa->ifa_flags & IFA_F_SECONDARY) {
1011 prim = inet_ifa_byprefix(in_dev, prefix, mask);
1012 if (!prim) {
1013 pr_warn("%s: bug: prim == NULL\n", __func__);
1014 return;
1015 }
1016 }
1017
1018 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0);
1019
1020 if (!(dev->flags & IFF_UP))
1021 return;
1022
1023 /* Add broadcast address, if it is explicitly assigned. */
1024 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
1025 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1026 prim, 0);
1027
1028 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
1029 (prefix != addr || ifa->ifa_prefixlen < 32)) {
1030 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1031 fib_magic(RTM_NEWROUTE,
1032 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1033 prefix, ifa->ifa_prefixlen, prim,
1034 ifa->ifa_rt_priority);
1035
1036 /* Add network specific broadcasts, when it takes a sense */
1037 if (ifa->ifa_prefixlen < 31) {
1038 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32,
1039 prim, 0);
1040 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
1041 32, prim, 0);
1042 }
1043 }
1044}
1045
1046void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric)
1047{
1048 __be32 prefix = ifa->ifa_address & ifa->ifa_mask;
1049 struct in_device *in_dev = ifa->ifa_dev;
1050 struct net_device *dev = in_dev->dev;
1051
1052 if (!(dev->flags & IFF_UP) ||
1053 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) ||
1054 ipv4_is_zeronet(prefix) ||
1055 prefix == ifa->ifa_local || ifa->ifa_prefixlen == 32)
1056 return;
1057
1058 /* add the new */
1059 fib_magic(RTM_NEWROUTE,
1060 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1061 prefix, ifa->ifa_prefixlen, ifa, new_metric);
1062
1063 /* delete the old */
1064 fib_magic(RTM_DELROUTE,
1065 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1066 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority);
1067}
1068
1069/* Delete primary or secondary address.
1070 * Optionally, on secondary address promotion consider the addresses
1071 * from subnet iprim as deleted, even if they are in device list.
1072 * In this case the secondary ifa can be in device list.
1073 */
1074void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
1075{
1076 struct in_device *in_dev = ifa->ifa_dev;
1077 struct net_device *dev = in_dev->dev;
1078 struct in_ifaddr *ifa1;
1079 struct in_ifaddr *prim = ifa, *prim1 = NULL;
1080 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
1081 __be32 any = ifa->ifa_address & ifa->ifa_mask;
1082#define LOCAL_OK 1
1083#define BRD_OK 2
1084#define BRD0_OK 4
1085#define BRD1_OK 8
1086 unsigned int ok = 0;
1087 int subnet = 0; /* Primary network */
1088 int gone = 1; /* Address is missing */
1089 int same_prefsrc = 0; /* Another primary with same IP */
1090
1091 if (ifa->ifa_flags & IFA_F_SECONDARY) {
1092 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
1093 if (!prim) {
1094 /* if the device has been deleted, we don't perform
1095 * address promotion
1096 */
1097 if (!in_dev->dead)
1098 pr_warn("%s: bug: prim == NULL\n", __func__);
1099 return;
1100 }
1101 if (iprim && iprim != prim) {
1102 pr_warn("%s: bug: iprim != prim\n", __func__);
1103 return;
1104 }
1105 } else if (!ipv4_is_zeronet(any) &&
1106 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
1107 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1108 fib_magic(RTM_DELROUTE,
1109 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1110 any, ifa->ifa_prefixlen, prim, 0);
1111 subnet = 1;
1112 }
1113
1114 if (in_dev->dead)
1115 goto no_promotions;
1116
1117 /* Deletion is more complicated than add.
1118 * We should take care of not to delete too much :-)
1119 *
1120 * Scan address list to be sure that addresses are really gone.
1121 */
1122
1123 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
1124 if (ifa1 == ifa) {
1125 /* promotion, keep the IP */
1126 gone = 0;
1127 continue;
1128 }
1129 /* Ignore IFAs from our subnet */
1130 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
1131 inet_ifa_match(ifa1->ifa_address, iprim))
1132 continue;
1133
1134 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
1135 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
1136 /* Another address from our subnet? */
1137 if (ifa1->ifa_mask == prim->ifa_mask &&
1138 inet_ifa_match(ifa1->ifa_address, prim))
1139 prim1 = prim;
1140 else {
1141 /* We reached the secondaries, so
1142 * same_prefsrc should be determined.
1143 */
1144 if (!same_prefsrc)
1145 continue;
1146 /* Search new prim1 if ifa1 is not
1147 * using the current prim1
1148 */
1149 if (!prim1 ||
1150 ifa1->ifa_mask != prim1->ifa_mask ||
1151 !inet_ifa_match(ifa1->ifa_address, prim1))
1152 prim1 = inet_ifa_byprefix(in_dev,
1153 ifa1->ifa_address,
1154 ifa1->ifa_mask);
1155 if (!prim1)
1156 continue;
1157 if (prim1->ifa_local != prim->ifa_local)
1158 continue;
1159 }
1160 } else {
1161 if (prim->ifa_local != ifa1->ifa_local)
1162 continue;
1163 prim1 = ifa1;
1164 if (prim != prim1)
1165 same_prefsrc = 1;
1166 }
1167 if (ifa->ifa_local == ifa1->ifa_local)
1168 ok |= LOCAL_OK;
1169 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1170 ok |= BRD_OK;
1171 if (brd == ifa1->ifa_broadcast)
1172 ok |= BRD1_OK;
1173 if (any == ifa1->ifa_broadcast)
1174 ok |= BRD0_OK;
1175 /* primary has network specific broadcasts */
1176 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1177 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1178 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1179
1180 if (!ipv4_is_zeronet(any1)) {
1181 if (ifa->ifa_broadcast == brd1 ||
1182 ifa->ifa_broadcast == any1)
1183 ok |= BRD_OK;
1184 if (brd == brd1 || brd == any1)
1185 ok |= BRD1_OK;
1186 if (any == brd1 || any == any1)
1187 ok |= BRD0_OK;
1188 }
1189 }
1190 }
1191
1192no_promotions:
1193 if (!(ok & BRD_OK))
1194 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1195 prim, 0);
1196 if (subnet && ifa->ifa_prefixlen < 31) {
1197 if (!(ok & BRD1_OK))
1198 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32,
1199 prim, 0);
1200 if (!(ok & BRD0_OK))
1201 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32,
1202 prim, 0);
1203 }
1204 if (!(ok & LOCAL_OK)) {
1205 unsigned int addr_type;
1206
1207 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0);
1208
1209 /* Check, that this local address finally disappeared. */
1210 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1211 ifa->ifa_local);
1212 if (gone && addr_type != RTN_LOCAL) {
1213 /* And the last, but not the least thing.
1214 * We must flush stray FIB entries.
1215 *
1216 * First of all, we scan fib_info list searching
1217 * for stray nexthop entries, then ignite fib_flush.
1218 */
1219 if (fib_sync_down_addr(dev, ifa->ifa_local))
1220 fib_flush(dev_net(dev));
1221 }
1222 }
1223#undef LOCAL_OK
1224#undef BRD_OK
1225#undef BRD0_OK
1226#undef BRD1_OK
1227}
1228
1229static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1230{
1231
1232 struct fib_result res;
1233 struct flowi4 fl4 = {
1234 .flowi4_mark = frn->fl_mark,
1235 .daddr = frn->fl_addr,
1236 .flowi4_tos = frn->fl_tos,
1237 .flowi4_scope = frn->fl_scope,
1238 };
1239 struct fib_table *tb;
1240
1241 rcu_read_lock();
1242
1243 tb = fib_get_table(net, frn->tb_id_in);
1244
1245 frn->err = -ENOENT;
1246 if (tb) {
1247 local_bh_disable();
1248
1249 frn->tb_id = tb->tb_id;
1250 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1251
1252 if (!frn->err) {
1253 frn->prefixlen = res.prefixlen;
1254 frn->nh_sel = res.nh_sel;
1255 frn->type = res.type;
1256 frn->scope = res.scope;
1257 }
1258 local_bh_enable();
1259 }
1260
1261 rcu_read_unlock();
1262}
1263
1264static void nl_fib_input(struct sk_buff *skb)
1265{
1266 struct net *net;
1267 struct fib_result_nl *frn;
1268 struct nlmsghdr *nlh;
1269 u32 portid;
1270
1271 net = sock_net(skb->sk);
1272 nlh = nlmsg_hdr(skb);
1273 if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1274 skb->len < nlh->nlmsg_len ||
1275 nlmsg_len(nlh) < sizeof(*frn))
1276 return;
1277
1278 skb = netlink_skb_clone(skb, GFP_KERNEL);
1279 if (!skb)
1280 return;
1281 nlh = nlmsg_hdr(skb);
1282
1283 frn = (struct fib_result_nl *) nlmsg_data(nlh);
1284 nl_fib_lookup(net, frn);
1285
1286 portid = NETLINK_CB(skb).portid; /* netlink portid */
1287 NETLINK_CB(skb).portid = 0; /* from kernel */
1288 NETLINK_CB(skb).dst_group = 0; /* unicast */
1289 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1290}
1291
1292static int __net_init nl_fib_lookup_init(struct net *net)
1293{
1294 struct sock *sk;
1295 struct netlink_kernel_cfg cfg = {
1296 .input = nl_fib_input,
1297 };
1298
1299 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1300 if (!sk)
1301 return -EAFNOSUPPORT;
1302 net->ipv4.fibnl = sk;
1303 return 0;
1304}
1305
1306static void nl_fib_lookup_exit(struct net *net)
1307{
1308 netlink_kernel_release(net->ipv4.fibnl);
1309 net->ipv4.fibnl = NULL;
1310}
1311
1312static void fib_disable_ip(struct net_device *dev, unsigned long event,
1313 bool force)
1314{
1315 if (fib_sync_down_dev(dev, event, force))
1316 fib_flush(dev_net(dev));
1317 else
1318 rt_cache_flush(dev_net(dev));
1319 arp_ifdown(dev);
1320}
1321
1322static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1323{
1324 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1325 struct net_device *dev = ifa->ifa_dev->dev;
1326 struct net *net = dev_net(dev);
1327
1328 switch (event) {
1329 case NETDEV_UP:
1330 fib_add_ifaddr(ifa);
1331#ifdef CONFIG_IP_ROUTE_MULTIPATH
1332 fib_sync_up(dev, RTNH_F_DEAD);
1333#endif
1334 atomic_inc(&net->ipv4.dev_addr_genid);
1335 rt_cache_flush(dev_net(dev));
1336 break;
1337 case NETDEV_DOWN:
1338 fib_del_ifaddr(ifa, NULL);
1339 atomic_inc(&net->ipv4.dev_addr_genid);
1340 if (!ifa->ifa_dev->ifa_list) {
1341 /* Last address was deleted from this interface.
1342 * Disable IP.
1343 */
1344 fib_disable_ip(dev, event, true);
1345 } else {
1346 rt_cache_flush(dev_net(dev));
1347 }
1348 break;
1349 }
1350 return NOTIFY_DONE;
1351}
1352
1353static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1354{
1355 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1356 struct netdev_notifier_changeupper_info *upper_info = ptr;
1357 struct netdev_notifier_info_ext *info_ext = ptr;
1358 struct in_device *in_dev;
1359 struct net *net = dev_net(dev);
1360 unsigned int flags;
1361
1362 if (event == NETDEV_UNREGISTER) {
1363 fib_disable_ip(dev, event, true);
1364 rt_flush_dev(dev);
1365 return NOTIFY_DONE;
1366 }
1367
1368 in_dev = __in_dev_get_rtnl(dev);
1369 if (!in_dev)
1370 return NOTIFY_DONE;
1371
1372 switch (event) {
1373 case NETDEV_UP:
1374 for_ifa(in_dev) {
1375 fib_add_ifaddr(ifa);
1376 } endfor_ifa(in_dev);
1377#ifdef CONFIG_IP_ROUTE_MULTIPATH
1378 fib_sync_up(dev, RTNH_F_DEAD);
1379#endif
1380 atomic_inc(&net->ipv4.dev_addr_genid);
1381 rt_cache_flush(net);
1382 break;
1383 case NETDEV_DOWN:
1384 fib_disable_ip(dev, event, false);
1385 break;
1386 case NETDEV_CHANGE:
1387 flags = dev_get_flags(dev);
1388 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1389 fib_sync_up(dev, RTNH_F_LINKDOWN);
1390 else
1391 fib_sync_down_dev(dev, event, false);
1392 rt_cache_flush(net);
1393 break;
1394 case NETDEV_CHANGEMTU:
1395 fib_sync_mtu(dev, info_ext->ext.mtu);
1396 rt_cache_flush(net);
1397 break;
1398 case NETDEV_CHANGEUPPER:
1399 upper_info = ptr;
1400 /* flush all routes if dev is linked to or unlinked from
1401 * an L3 master device (e.g., VRF)
1402 */
1403 if (upper_info->upper_dev &&
1404 netif_is_l3_master(upper_info->upper_dev))
1405 fib_disable_ip(dev, NETDEV_DOWN, true);
1406 break;
1407 }
1408 return NOTIFY_DONE;
1409}
1410
1411static struct notifier_block fib_inetaddr_notifier = {
1412 .notifier_call = fib_inetaddr_event,
1413};
1414
1415static struct notifier_block fib_netdev_notifier = {
1416 .notifier_call = fib_netdev_event,
1417};
1418
1419static int __net_init ip_fib_net_init(struct net *net)
1420{
1421 int err;
1422 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1423
1424 err = fib4_notifier_init(net);
1425 if (err)
1426 return err;
1427
1428 /* Avoid false sharing : Use at least a full cache line */
1429 size = max_t(size_t, size, L1_CACHE_BYTES);
1430
1431 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1432 if (!net->ipv4.fib_table_hash) {
1433 err = -ENOMEM;
1434 goto err_table_hash_alloc;
1435 }
1436
1437 err = fib4_rules_init(net);
1438 if (err < 0)
1439 goto err_rules_init;
1440 return 0;
1441
1442err_rules_init:
1443 kfree(net->ipv4.fib_table_hash);
1444err_table_hash_alloc:
1445 fib4_notifier_exit(net);
1446 return err;
1447}
1448
1449static void ip_fib_net_exit(struct net *net)
1450{
1451 int i;
1452
1453 rtnl_lock();
1454#ifdef CONFIG_IP_MULTIPLE_TABLES
1455 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1456 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1457#endif
1458 /* Destroy the tables in reverse order to guarantee that the
1459 * local table, ID 255, is destroyed before the main table, ID
1460 * 254. This is necessary as the local table may contain
1461 * references to data contained in the main table.
1462 */
1463 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1464 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1465 struct hlist_node *tmp;
1466 struct fib_table *tb;
1467
1468 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1469 hlist_del(&tb->tb_hlist);
1470 fib_table_flush(net, tb, true);
1471 fib_free_table(tb);
1472 }
1473 }
1474
1475#ifdef CONFIG_IP_MULTIPLE_TABLES
1476 fib4_rules_exit(net);
1477#endif
1478 rtnl_unlock();
1479 kfree(net->ipv4.fib_table_hash);
1480 fib4_notifier_exit(net);
1481}
1482
1483static int __net_init fib_net_init(struct net *net)
1484{
1485 int error;
1486
1487#ifdef CONFIG_IP_ROUTE_CLASSID
1488 net->ipv4.fib_num_tclassid_users = 0;
1489#endif
1490 error = ip_fib_net_init(net);
1491 if (error < 0)
1492 goto out;
1493 error = nl_fib_lookup_init(net);
1494 if (error < 0)
1495 goto out_nlfl;
1496 error = fib_proc_init(net);
1497 if (error < 0)
1498 goto out_proc;
1499out:
1500 return error;
1501
1502out_proc:
1503 nl_fib_lookup_exit(net);
1504out_nlfl:
1505 ip_fib_net_exit(net);
1506 goto out;
1507}
1508
1509static void __net_exit fib_net_exit(struct net *net)
1510{
1511 fib_proc_exit(net);
1512 nl_fib_lookup_exit(net);
1513 ip_fib_net_exit(net);
1514}
1515
1516static struct pernet_operations fib_net_ops = {
1517 .init = fib_net_init,
1518 .exit = fib_net_exit,
1519};
1520
1521void __init ip_fib_init(void)
1522{
1523 fib_trie_init();
1524
1525 register_pernet_subsys(&fib_net_ops);
1526
1527 register_netdevice_notifier(&fib_netdev_notifier);
1528 register_inetaddr_notifier(&fib_inetaddr_notifier);
1529
1530 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0);
1531 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0);
1532 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0);
1533}
1534