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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);
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 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 */
325static 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 struct net *net = dev_net(dev);
330 struct flow_keys flkeys;
331 int ret, no_addr;
332 struct fib_result res;
333 struct flowi4 fl4;
334 bool dev_match;
335
336 fl4.flowi4_oif = 0;
337 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
338 if (!fl4.flowi4_iif)
339 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
340 fl4.daddr = src;
341 fl4.saddr = dst;
342 fl4.flowi4_tos = tos;
343 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
344 fl4.flowi4_tun_key.tun_id = 0;
345 fl4.flowi4_flags = 0;
346 fl4.flowi4_uid = sock_net_uid(net, NULL);
347
348 no_addr = idev->ifa_list == NULL;
349
350 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
351 if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) {
352 fl4.flowi4_proto = 0;
353 fl4.fl4_sport = 0;
354 fl4.fl4_dport = 0;
355 }
356
357 trace_fib_validate_source(dev, &fl4);
358
359 if (fib_lookup(net, &fl4, &res, 0))
360 goto last_resort;
361 if (res.type != RTN_UNICAST &&
362 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
363 goto e_inval;
364 fib_combine_itag(itag, &res);
365 dev_match = false;
366
367#ifdef CONFIG_IP_ROUTE_MULTIPATH
368 for (ret = 0; ret < res.fi->fib_nhs; ret++) {
369 struct fib_nh *nh = &res.fi->fib_nh[ret];
370
371 if (nh->nh_dev == dev) {
372 dev_match = true;
373 break;
374 } else if (l3mdev_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
375 dev_match = true;
376 break;
377 }
378 }
379#else
380 if (FIB_RES_DEV(res) == dev)
381 dev_match = true;
382#endif
383 if (dev_match) {
384 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
385 return ret;
386 }
387 if (no_addr)
388 goto last_resort;
389 if (rpf == 1)
390 goto e_rpf;
391 fl4.flowi4_oif = dev->ifindex;
392
393 ret = 0;
394 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
395 if (res.type == RTN_UNICAST)
396 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
397 }
398 return ret;
399
400last_resort:
401 if (rpf)
402 goto e_rpf;
403 *itag = 0;
404 return 0;
405
406e_inval:
407 return -EINVAL;
408e_rpf:
409 return -EXDEV;
410}
411
412/* Ignore rp_filter for packets protected by IPsec. */
413int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
414 u8 tos, int oif, struct net_device *dev,
415 struct in_device *idev, u32 *itag)
416{
417 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
418 struct net *net = dev_net(dev);
419
420 if (!r && !fib_num_tclassid_users(net) &&
421 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
422 if (IN_DEV_ACCEPT_LOCAL(idev))
423 goto ok;
424 /* with custom local routes in place, checking local addresses
425 * only will be too optimistic, with custom rules, checking
426 * local addresses only can be too strict, e.g. due to vrf
427 */
428 if (net->ipv4.fib_has_custom_local_routes ||
429 fib4_has_custom_rules(net))
430 goto full_check;
431 if (inet_lookup_ifaddr_rcu(net, src))
432 return -EINVAL;
433
434ok:
435 *itag = 0;
436 return 0;
437 }
438
439full_check:
440 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
441}
442
443static inline __be32 sk_extract_addr(struct sockaddr *addr)
444{
445 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
446}
447
448static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
449{
450 struct nlattr *nla;
451
452 nla = (struct nlattr *) ((char *) mx + len);
453 nla->nla_type = type;
454 nla->nla_len = nla_attr_size(4);
455 *(u32 *) nla_data(nla) = value;
456
457 return len + nla_total_size(4);
458}
459
460static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
461 struct fib_config *cfg)
462{
463 __be32 addr;
464 int plen;
465
466 memset(cfg, 0, sizeof(*cfg));
467 cfg->fc_nlinfo.nl_net = net;
468
469 if (rt->rt_dst.sa_family != AF_INET)
470 return -EAFNOSUPPORT;
471
472 /*
473 * Check mask for validity:
474 * a) it must be contiguous.
475 * b) destination must have all host bits clear.
476 * c) if application forgot to set correct family (AF_INET),
477 * reject request unless it is absolutely clear i.e.
478 * both family and mask are zero.
479 */
480 plen = 32;
481 addr = sk_extract_addr(&rt->rt_dst);
482 if (!(rt->rt_flags & RTF_HOST)) {
483 __be32 mask = sk_extract_addr(&rt->rt_genmask);
484
485 if (rt->rt_genmask.sa_family != AF_INET) {
486 if (mask || rt->rt_genmask.sa_family)
487 return -EAFNOSUPPORT;
488 }
489
490 if (bad_mask(mask, addr))
491 return -EINVAL;
492
493 plen = inet_mask_len(mask);
494 }
495
496 cfg->fc_dst_len = plen;
497 cfg->fc_dst = addr;
498
499 if (cmd != SIOCDELRT) {
500 cfg->fc_nlflags = NLM_F_CREATE;
501 cfg->fc_protocol = RTPROT_BOOT;
502 }
503
504 if (rt->rt_metric)
505 cfg->fc_priority = rt->rt_metric - 1;
506
507 if (rt->rt_flags & RTF_REJECT) {
508 cfg->fc_scope = RT_SCOPE_HOST;
509 cfg->fc_type = RTN_UNREACHABLE;
510 return 0;
511 }
512
513 cfg->fc_scope = RT_SCOPE_NOWHERE;
514 cfg->fc_type = RTN_UNICAST;
515
516 if (rt->rt_dev) {
517 char *colon;
518 struct net_device *dev;
519 char devname[IFNAMSIZ];
520
521 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
522 return -EFAULT;
523
524 devname[IFNAMSIZ-1] = 0;
525 colon = strchr(devname, ':');
526 if (colon)
527 *colon = 0;
528 dev = __dev_get_by_name(net, devname);
529 if (!dev)
530 return -ENODEV;
531 cfg->fc_oif = dev->ifindex;
532 cfg->fc_table = l3mdev_fib_table(dev);
533 if (colon) {
534 struct in_ifaddr *ifa;
535 struct in_device *in_dev = __in_dev_get_rtnl(dev);
536 if (!in_dev)
537 return -ENODEV;
538 *colon = ':';
539 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
540 if (strcmp(ifa->ifa_label, devname) == 0)
541 break;
542 if (!ifa)
543 return -ENODEV;
544 cfg->fc_prefsrc = ifa->ifa_local;
545 }
546 }
547
548 addr = sk_extract_addr(&rt->rt_gateway);
549 if (rt->rt_gateway.sa_family == AF_INET && addr) {
550 unsigned int addr_type;
551
552 cfg->fc_gw = addr;
553 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
554 if (rt->rt_flags & RTF_GATEWAY &&
555 addr_type == RTN_UNICAST)
556 cfg->fc_scope = RT_SCOPE_UNIVERSE;
557 }
558
559 if (cmd == SIOCDELRT)
560 return 0;
561
562 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
563 return -EINVAL;
564
565 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
566 cfg->fc_scope = RT_SCOPE_LINK;
567
568 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
569 struct nlattr *mx;
570 int len = 0;
571
572 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
573 if (!mx)
574 return -ENOMEM;
575
576 if (rt->rt_flags & RTF_MTU)
577 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
578
579 if (rt->rt_flags & RTF_WINDOW)
580 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
581
582 if (rt->rt_flags & RTF_IRTT)
583 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
584
585 cfg->fc_mx = mx;
586 cfg->fc_mx_len = len;
587 }
588
589 return 0;
590}
591
592/*
593 * Handle IP routing ioctl calls.
594 * These are used to manipulate the routing tables
595 */
596int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
597{
598 struct fib_config cfg;
599 int err;
600
601 switch (cmd) {
602 case SIOCADDRT: /* Add a route */
603 case SIOCDELRT: /* Delete a route */
604 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
605 return -EPERM;
606
607 rtnl_lock();
608 err = rtentry_to_fib_config(net, cmd, rt, &cfg);
609 if (err == 0) {
610 struct fib_table *tb;
611
612 if (cmd == SIOCDELRT) {
613 tb = fib_get_table(net, cfg.fc_table);
614 if (tb)
615 err = fib_table_delete(net, tb, &cfg,
616 NULL);
617 else
618 err = -ESRCH;
619 } else {
620 tb = fib_new_table(net, cfg.fc_table);
621 if (tb)
622 err = fib_table_insert(net, tb,
623 &cfg, NULL);
624 else
625 err = -ENOBUFS;
626 }
627
628 /* allocated by rtentry_to_fib_config() */
629 kfree(cfg.fc_mx);
630 }
631 rtnl_unlock();
632 return err;
633 }
634 return -EINVAL;
635}
636
637const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
638 [RTA_DST] = { .type = NLA_U32 },
639 [RTA_SRC] = { .type = NLA_U32 },
640 [RTA_IIF] = { .type = NLA_U32 },
641 [RTA_OIF] = { .type = NLA_U32 },
642 [RTA_GATEWAY] = { .type = NLA_U32 },
643 [RTA_PRIORITY] = { .type = NLA_U32 },
644 [RTA_PREFSRC] = { .type = NLA_U32 },
645 [RTA_METRICS] = { .type = NLA_NESTED },
646 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
647 [RTA_FLOW] = { .type = NLA_U32 },
648 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
649 [RTA_ENCAP] = { .type = NLA_NESTED },
650 [RTA_UID] = { .type = NLA_U32 },
651 [RTA_MARK] = { .type = NLA_U32 },
652 [RTA_TABLE] = { .type = NLA_U32 },
653};
654
655static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
656 struct nlmsghdr *nlh, struct fib_config *cfg,
657 struct netlink_ext_ack *extack)
658{
659 struct nlattr *attr;
660 int err, remaining;
661 struct rtmsg *rtm;
662
663 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy,
664 extack);
665 if (err < 0)
666 goto errout;
667
668 memset(cfg, 0, sizeof(*cfg));
669
670 rtm = nlmsg_data(nlh);
671 cfg->fc_dst_len = rtm->rtm_dst_len;
672 cfg->fc_tos = rtm->rtm_tos;
673 cfg->fc_table = rtm->rtm_table;
674 cfg->fc_protocol = rtm->rtm_protocol;
675 cfg->fc_scope = rtm->rtm_scope;
676 cfg->fc_type = rtm->rtm_type;
677 cfg->fc_flags = rtm->rtm_flags;
678 cfg->fc_nlflags = nlh->nlmsg_flags;
679
680 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
681 cfg->fc_nlinfo.nlh = nlh;
682 cfg->fc_nlinfo.nl_net = net;
683
684 if (cfg->fc_type > RTN_MAX) {
685 NL_SET_ERR_MSG(extack, "Invalid route type");
686 err = -EINVAL;
687 goto errout;
688 }
689
690 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
691 switch (nla_type(attr)) {
692 case RTA_DST:
693 cfg->fc_dst = nla_get_be32(attr);
694 break;
695 case RTA_OIF:
696 cfg->fc_oif = nla_get_u32(attr);
697 break;
698 case RTA_GATEWAY:
699 cfg->fc_gw = nla_get_be32(attr);
700 break;
701 case RTA_PRIORITY:
702 cfg->fc_priority = nla_get_u32(attr);
703 break;
704 case RTA_PREFSRC:
705 cfg->fc_prefsrc = nla_get_be32(attr);
706 break;
707 case RTA_METRICS:
708 cfg->fc_mx = nla_data(attr);
709 cfg->fc_mx_len = nla_len(attr);
710 break;
711 case RTA_MULTIPATH:
712 err = lwtunnel_valid_encap_type_attr(nla_data(attr),
713 nla_len(attr),
714 extack);
715 if (err < 0)
716 goto errout;
717 cfg->fc_mp = nla_data(attr);
718 cfg->fc_mp_len = nla_len(attr);
719 break;
720 case RTA_FLOW:
721 cfg->fc_flow = nla_get_u32(attr);
722 break;
723 case RTA_TABLE:
724 cfg->fc_table = nla_get_u32(attr);
725 break;
726 case RTA_ENCAP:
727 cfg->fc_encap = attr;
728 break;
729 case RTA_ENCAP_TYPE:
730 cfg->fc_encap_type = nla_get_u16(attr);
731 err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
732 extack);
733 if (err < 0)
734 goto errout;
735 break;
736 }
737 }
738
739 return 0;
740errout:
741 return err;
742}
743
744static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
745 struct netlink_ext_ack *extack)
746{
747 struct net *net = sock_net(skb->sk);
748 struct fib_config cfg;
749 struct fib_table *tb;
750 int err;
751
752 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
753 if (err < 0)
754 goto errout;
755
756 tb = fib_get_table(net, cfg.fc_table);
757 if (!tb) {
758 NL_SET_ERR_MSG(extack, "FIB table does not exist");
759 err = -ESRCH;
760 goto errout;
761 }
762
763 err = fib_table_delete(net, tb, &cfg, extack);
764errout:
765 return err;
766}
767
768static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
769 struct netlink_ext_ack *extack)
770{
771 struct net *net = sock_net(skb->sk);
772 struct fib_config cfg;
773 struct fib_table *tb;
774 int err;
775
776 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
777 if (err < 0)
778 goto errout;
779
780 tb = fib_new_table(net, cfg.fc_table);
781 if (!tb) {
782 err = -ENOBUFS;
783 goto errout;
784 }
785
786 err = fib_table_insert(net, tb, &cfg, extack);
787 if (!err && cfg.fc_type == RTN_LOCAL)
788 net->ipv4.fib_has_custom_local_routes = true;
789errout:
790 return err;
791}
792
793static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
794{
795 struct net *net = sock_net(skb->sk);
796 unsigned int h, s_h;
797 unsigned int e = 0, s_e;
798 struct fib_table *tb;
799 struct hlist_head *head;
800 int dumped = 0, err;
801
802 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
803 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
804 return skb->len;
805
806 s_h = cb->args[0];
807 s_e = cb->args[1];
808
809 rcu_read_lock();
810
811 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
812 e = 0;
813 head = &net->ipv4.fib_table_hash[h];
814 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
815 if (e < s_e)
816 goto next;
817 if (dumped)
818 memset(&cb->args[2], 0, sizeof(cb->args) -
819 2 * sizeof(cb->args[0]));
820 err = fib_table_dump(tb, skb, cb);
821 if (err < 0) {
822 if (likely(skb->len))
823 goto out;
824
825 goto out_err;
826 }
827 dumped = 1;
828next:
829 e++;
830 }
831 }
832out:
833 err = skb->len;
834out_err:
835 rcu_read_unlock();
836
837 cb->args[1] = e;
838 cb->args[0] = h;
839
840 return err;
841}
842
843/* Prepare and feed intra-kernel routing request.
844 * Really, it should be netlink message, but :-( netlink
845 * can be not configured, so that we feed it directly
846 * to fib engine. It is legal, because all events occur
847 * only when netlink is already locked.
848 */
849static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
850{
851 struct net *net = dev_net(ifa->ifa_dev->dev);
852 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
853 struct fib_table *tb;
854 struct fib_config cfg = {
855 .fc_protocol = RTPROT_KERNEL,
856 .fc_type = type,
857 .fc_dst = dst,
858 .fc_dst_len = dst_len,
859 .fc_prefsrc = ifa->ifa_local,
860 .fc_oif = ifa->ifa_dev->dev->ifindex,
861 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
862 .fc_nlinfo = {
863 .nl_net = net,
864 },
865 };
866
867 if (!tb_id)
868 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
869
870 tb = fib_new_table(net, tb_id);
871 if (!tb)
872 return;
873
874 cfg.fc_table = tb->tb_id;
875
876 if (type != RTN_LOCAL)
877 cfg.fc_scope = RT_SCOPE_LINK;
878 else
879 cfg.fc_scope = RT_SCOPE_HOST;
880
881 if (cmd == RTM_NEWROUTE)
882 fib_table_insert(net, tb, &cfg, NULL);
883 else
884 fib_table_delete(net, tb, &cfg, NULL);
885}
886
887void fib_add_ifaddr(struct in_ifaddr *ifa)
888{
889 struct in_device *in_dev = ifa->ifa_dev;
890 struct net_device *dev = in_dev->dev;
891 struct in_ifaddr *prim = ifa;
892 __be32 mask = ifa->ifa_mask;
893 __be32 addr = ifa->ifa_local;
894 __be32 prefix = ifa->ifa_address & mask;
895
896 if (ifa->ifa_flags & IFA_F_SECONDARY) {
897 prim = inet_ifa_byprefix(in_dev, prefix, mask);
898 if (!prim) {
899 pr_warn("%s: bug: prim == NULL\n", __func__);
900 return;
901 }
902 }
903
904 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
905
906 if (!(dev->flags & IFF_UP))
907 return;
908
909 /* Add broadcast address, if it is explicitly assigned. */
910 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
911 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
912
913 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
914 (prefix != addr || ifa->ifa_prefixlen < 32)) {
915 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
916 fib_magic(RTM_NEWROUTE,
917 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
918 prefix, ifa->ifa_prefixlen, prim);
919
920 /* Add network specific broadcasts, when it takes a sense */
921 if (ifa->ifa_prefixlen < 31) {
922 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
923 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
924 32, prim);
925 }
926 }
927}
928
929/* Delete primary or secondary address.
930 * Optionally, on secondary address promotion consider the addresses
931 * from subnet iprim as deleted, even if they are in device list.
932 * In this case the secondary ifa can be in device list.
933 */
934void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
935{
936 struct in_device *in_dev = ifa->ifa_dev;
937 struct net_device *dev = in_dev->dev;
938 struct in_ifaddr *ifa1;
939 struct in_ifaddr *prim = ifa, *prim1 = NULL;
940 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
941 __be32 any = ifa->ifa_address & ifa->ifa_mask;
942#define LOCAL_OK 1
943#define BRD_OK 2
944#define BRD0_OK 4
945#define BRD1_OK 8
946 unsigned int ok = 0;
947 int subnet = 0; /* Primary network */
948 int gone = 1; /* Address is missing */
949 int same_prefsrc = 0; /* Another primary with same IP */
950
951 if (ifa->ifa_flags & IFA_F_SECONDARY) {
952 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
953 if (!prim) {
954 /* if the device has been deleted, we don't perform
955 * address promotion
956 */
957 if (!in_dev->dead)
958 pr_warn("%s: bug: prim == NULL\n", __func__);
959 return;
960 }
961 if (iprim && iprim != prim) {
962 pr_warn("%s: bug: iprim != prim\n", __func__);
963 return;
964 }
965 } else if (!ipv4_is_zeronet(any) &&
966 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
967 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
968 fib_magic(RTM_DELROUTE,
969 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
970 any, ifa->ifa_prefixlen, prim);
971 subnet = 1;
972 }
973
974 if (in_dev->dead)
975 goto no_promotions;
976
977 /* Deletion is more complicated than add.
978 * We should take care of not to delete too much :-)
979 *
980 * Scan address list to be sure that addresses are really gone.
981 */
982
983 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
984 if (ifa1 == ifa) {
985 /* promotion, keep the IP */
986 gone = 0;
987 continue;
988 }
989 /* Ignore IFAs from our subnet */
990 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
991 inet_ifa_match(ifa1->ifa_address, iprim))
992 continue;
993
994 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
995 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
996 /* Another address from our subnet? */
997 if (ifa1->ifa_mask == prim->ifa_mask &&
998 inet_ifa_match(ifa1->ifa_address, prim))
999 prim1 = prim;
1000 else {
1001 /* We reached the secondaries, so
1002 * same_prefsrc should be determined.
1003 */
1004 if (!same_prefsrc)
1005 continue;
1006 /* Search new prim1 if ifa1 is not
1007 * using the current prim1
1008 */
1009 if (!prim1 ||
1010 ifa1->ifa_mask != prim1->ifa_mask ||
1011 !inet_ifa_match(ifa1->ifa_address, prim1))
1012 prim1 = inet_ifa_byprefix(in_dev,
1013 ifa1->ifa_address,
1014 ifa1->ifa_mask);
1015 if (!prim1)
1016 continue;
1017 if (prim1->ifa_local != prim->ifa_local)
1018 continue;
1019 }
1020 } else {
1021 if (prim->ifa_local != ifa1->ifa_local)
1022 continue;
1023 prim1 = ifa1;
1024 if (prim != prim1)
1025 same_prefsrc = 1;
1026 }
1027 if (ifa->ifa_local == ifa1->ifa_local)
1028 ok |= LOCAL_OK;
1029 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1030 ok |= BRD_OK;
1031 if (brd == ifa1->ifa_broadcast)
1032 ok |= BRD1_OK;
1033 if (any == ifa1->ifa_broadcast)
1034 ok |= BRD0_OK;
1035 /* primary has network specific broadcasts */
1036 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1037 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1038 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1039
1040 if (!ipv4_is_zeronet(any1)) {
1041 if (ifa->ifa_broadcast == brd1 ||
1042 ifa->ifa_broadcast == any1)
1043 ok |= BRD_OK;
1044 if (brd == brd1 || brd == any1)
1045 ok |= BRD1_OK;
1046 if (any == brd1 || any == any1)
1047 ok |= BRD0_OK;
1048 }
1049 }
1050 }
1051
1052no_promotions:
1053 if (!(ok & BRD_OK))
1054 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
1055 if (subnet && ifa->ifa_prefixlen < 31) {
1056 if (!(ok & BRD1_OK))
1057 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
1058 if (!(ok & BRD0_OK))
1059 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
1060 }
1061 if (!(ok & LOCAL_OK)) {
1062 unsigned int addr_type;
1063
1064 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
1065
1066 /* Check, that this local address finally disappeared. */
1067 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1068 ifa->ifa_local);
1069 if (gone && addr_type != RTN_LOCAL) {
1070 /* And the last, but not the least thing.
1071 * We must flush stray FIB entries.
1072 *
1073 * First of all, we scan fib_info list searching
1074 * for stray nexthop entries, then ignite fib_flush.
1075 */
1076 if (fib_sync_down_addr(dev, ifa->ifa_local))
1077 fib_flush(dev_net(dev));
1078 }
1079 }
1080#undef LOCAL_OK
1081#undef BRD_OK
1082#undef BRD0_OK
1083#undef BRD1_OK
1084}
1085
1086static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1087{
1088
1089 struct fib_result res;
1090 struct flowi4 fl4 = {
1091 .flowi4_mark = frn->fl_mark,
1092 .daddr = frn->fl_addr,
1093 .flowi4_tos = frn->fl_tos,
1094 .flowi4_scope = frn->fl_scope,
1095 };
1096 struct fib_table *tb;
1097
1098 rcu_read_lock();
1099
1100 tb = fib_get_table(net, frn->tb_id_in);
1101
1102 frn->err = -ENOENT;
1103 if (tb) {
1104 local_bh_disable();
1105
1106 frn->tb_id = tb->tb_id;
1107 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1108
1109 if (!frn->err) {
1110 frn->prefixlen = res.prefixlen;
1111 frn->nh_sel = res.nh_sel;
1112 frn->type = res.type;
1113 frn->scope = res.scope;
1114 }
1115 local_bh_enable();
1116 }
1117
1118 rcu_read_unlock();
1119}
1120
1121static void nl_fib_input(struct sk_buff *skb)
1122{
1123 struct net *net;
1124 struct fib_result_nl *frn;
1125 struct nlmsghdr *nlh;
1126 u32 portid;
1127
1128 net = sock_net(skb->sk);
1129 nlh = nlmsg_hdr(skb);
1130 if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1131 skb->len < nlh->nlmsg_len ||
1132 nlmsg_len(nlh) < sizeof(*frn))
1133 return;
1134
1135 skb = netlink_skb_clone(skb, GFP_KERNEL);
1136 if (!skb)
1137 return;
1138 nlh = nlmsg_hdr(skb);
1139
1140 frn = (struct fib_result_nl *) nlmsg_data(nlh);
1141 nl_fib_lookup(net, frn);
1142
1143 portid = NETLINK_CB(skb).portid; /* netlink portid */
1144 NETLINK_CB(skb).portid = 0; /* from kernel */
1145 NETLINK_CB(skb).dst_group = 0; /* unicast */
1146 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1147}
1148
1149static int __net_init nl_fib_lookup_init(struct net *net)
1150{
1151 struct sock *sk;
1152 struct netlink_kernel_cfg cfg = {
1153 .input = nl_fib_input,
1154 };
1155
1156 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1157 if (!sk)
1158 return -EAFNOSUPPORT;
1159 net->ipv4.fibnl = sk;
1160 return 0;
1161}
1162
1163static void nl_fib_lookup_exit(struct net *net)
1164{
1165 netlink_kernel_release(net->ipv4.fibnl);
1166 net->ipv4.fibnl = NULL;
1167}
1168
1169static void fib_disable_ip(struct net_device *dev, unsigned long event,
1170 bool force)
1171{
1172 if (fib_sync_down_dev(dev, event, force))
1173 fib_flush(dev_net(dev));
1174 else
1175 rt_cache_flush(dev_net(dev));
1176 arp_ifdown(dev);
1177}
1178
1179static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1180{
1181 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1182 struct net_device *dev = ifa->ifa_dev->dev;
1183 struct net *net = dev_net(dev);
1184
1185 switch (event) {
1186 case NETDEV_UP:
1187 fib_add_ifaddr(ifa);
1188#ifdef CONFIG_IP_ROUTE_MULTIPATH
1189 fib_sync_up(dev, RTNH_F_DEAD);
1190#endif
1191 atomic_inc(&net->ipv4.dev_addr_genid);
1192 rt_cache_flush(dev_net(dev));
1193 break;
1194 case NETDEV_DOWN:
1195 fib_del_ifaddr(ifa, NULL);
1196 atomic_inc(&net->ipv4.dev_addr_genid);
1197 if (!ifa->ifa_dev->ifa_list) {
1198 /* Last address was deleted from this interface.
1199 * Disable IP.
1200 */
1201 fib_disable_ip(dev, event, true);
1202 } else {
1203 rt_cache_flush(dev_net(dev));
1204 }
1205 break;
1206 }
1207 return NOTIFY_DONE;
1208}
1209
1210static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1211{
1212 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1213 struct netdev_notifier_changeupper_info *info;
1214 struct in_device *in_dev;
1215 struct net *net = dev_net(dev);
1216 unsigned int flags;
1217
1218 if (event == NETDEV_UNREGISTER) {
1219 fib_disable_ip(dev, event, true);
1220 rt_flush_dev(dev);
1221 return NOTIFY_DONE;
1222 }
1223
1224 in_dev = __in_dev_get_rtnl(dev);
1225 if (!in_dev)
1226 return NOTIFY_DONE;
1227
1228 switch (event) {
1229 case NETDEV_UP:
1230 for_ifa(in_dev) {
1231 fib_add_ifaddr(ifa);
1232 } endfor_ifa(in_dev);
1233#ifdef CONFIG_IP_ROUTE_MULTIPATH
1234 fib_sync_up(dev, RTNH_F_DEAD);
1235#endif
1236 atomic_inc(&net->ipv4.dev_addr_genid);
1237 rt_cache_flush(net);
1238 break;
1239 case NETDEV_DOWN:
1240 fib_disable_ip(dev, event, false);
1241 break;
1242 case NETDEV_CHANGE:
1243 flags = dev_get_flags(dev);
1244 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1245 fib_sync_up(dev, RTNH_F_LINKDOWN);
1246 else
1247 fib_sync_down_dev(dev, event, false);
1248 /* fall through */
1249 case NETDEV_CHANGEMTU:
1250 rt_cache_flush(net);
1251 break;
1252 case NETDEV_CHANGEUPPER:
1253 info = ptr;
1254 /* flush all routes if dev is linked to or unlinked from
1255 * an L3 master device (e.g., VRF)
1256 */
1257 if (info->upper_dev && netif_is_l3_master(info->upper_dev))
1258 fib_disable_ip(dev, NETDEV_DOWN, true);
1259 break;
1260 }
1261 return NOTIFY_DONE;
1262}
1263
1264static struct notifier_block fib_inetaddr_notifier = {
1265 .notifier_call = fib_inetaddr_event,
1266};
1267
1268static struct notifier_block fib_netdev_notifier = {
1269 .notifier_call = fib_netdev_event,
1270};
1271
1272static int __net_init ip_fib_net_init(struct net *net)
1273{
1274 int err;
1275 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1276
1277 err = fib4_notifier_init(net);
1278 if (err)
1279 return err;
1280
1281 /* Avoid false sharing : Use at least a full cache line */
1282 size = max_t(size_t, size, L1_CACHE_BYTES);
1283
1284 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1285 if (!net->ipv4.fib_table_hash) {
1286 err = -ENOMEM;
1287 goto err_table_hash_alloc;
1288 }
1289
1290 err = fib4_rules_init(net);
1291 if (err < 0)
1292 goto err_rules_init;
1293 return 0;
1294
1295err_rules_init:
1296 kfree(net->ipv4.fib_table_hash);
1297err_table_hash_alloc:
1298 fib4_notifier_exit(net);
1299 return err;
1300}
1301
1302static void ip_fib_net_exit(struct net *net)
1303{
1304 int i;
1305
1306 rtnl_lock();
1307#ifdef CONFIG_IP_MULTIPLE_TABLES
1308 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1309 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1310#endif
1311 /* Destroy the tables in reverse order to guarantee that the
1312 * local table, ID 255, is destroyed before the main table, ID
1313 * 254. This is necessary as the local table may contain
1314 * references to data contained in the main table.
1315 */
1316 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1317 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1318 struct hlist_node *tmp;
1319 struct fib_table *tb;
1320
1321 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1322 hlist_del(&tb->tb_hlist);
1323 fib_table_flush(net, tb);
1324 fib_free_table(tb);
1325 }
1326 }
1327
1328#ifdef CONFIG_IP_MULTIPLE_TABLES
1329 fib4_rules_exit(net);
1330#endif
1331 rtnl_unlock();
1332 kfree(net->ipv4.fib_table_hash);
1333 fib4_notifier_exit(net);
1334}
1335
1336static int __net_init fib_net_init(struct net *net)
1337{
1338 int error;
1339
1340#ifdef CONFIG_IP_ROUTE_CLASSID
1341 net->ipv4.fib_num_tclassid_users = 0;
1342#endif
1343 error = ip_fib_net_init(net);
1344 if (error < 0)
1345 goto out;
1346 error = nl_fib_lookup_init(net);
1347 if (error < 0)
1348 goto out_nlfl;
1349 error = fib_proc_init(net);
1350 if (error < 0)
1351 goto out_proc;
1352out:
1353 return error;
1354
1355out_proc:
1356 nl_fib_lookup_exit(net);
1357out_nlfl:
1358 ip_fib_net_exit(net);
1359 goto out;
1360}
1361
1362static void __net_exit fib_net_exit(struct net *net)
1363{
1364 fib_proc_exit(net);
1365 nl_fib_lookup_exit(net);
1366 ip_fib_net_exit(net);
1367}
1368
1369static struct pernet_operations fib_net_ops = {
1370 .init = fib_net_init,
1371 .exit = fib_net_exit,
1372};
1373
1374void __init ip_fib_init(void)
1375{
1376 fib_trie_init();
1377
1378 register_pernet_subsys(&fib_net_ops);
1379
1380 register_netdevice_notifier(&fib_netdev_notifier);
1381 register_inetaddr_notifier(&fib_inetaddr_notifier);
1382
1383 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0);
1384 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0);
1385 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0);
1386}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * IPv4 Forwarding Information Base: FIB frontend.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 */
11
12#include <linux/module.h>
13#include <linux/uaccess.h>
14#include <linux/bitops.h>
15#include <linux/capability.h>
16#include <linux/types.h>
17#include <linux/kernel.h>
18#include <linux/mm.h>
19#include <linux/string.h>
20#include <linux/socket.h>
21#include <linux/sockios.h>
22#include <linux/errno.h>
23#include <linux/in.h>
24#include <linux/inet.h>
25#include <linux/inetdevice.h>
26#include <linux/netdevice.h>
27#include <linux/if_addr.h>
28#include <linux/if_arp.h>
29#include <linux/skbuff.h>
30#include <linux/cache.h>
31#include <linux/init.h>
32#include <linux/list.h>
33#include <linux/slab.h>
34
35#include <net/ip.h>
36#include <net/protocol.h>
37#include <net/route.h>
38#include <net/tcp.h>
39#include <net/sock.h>
40#include <net/arp.h>
41#include <net/ip_fib.h>
42#include <net/nexthop.h>
43#include <net/rtnetlink.h>
44#include <net/xfrm.h>
45#include <net/l3mdev.h>
46#include <net/lwtunnel.h>
47#include <trace/events/fib.h>
48
49#ifndef CONFIG_IP_MULTIPLE_TABLES
50
51static int __net_init fib4_rules_init(struct net *net)
52{
53 struct fib_table *local_table, *main_table;
54
55 main_table = fib_trie_table(RT_TABLE_MAIN, NULL);
56 if (!main_table)
57 return -ENOMEM;
58
59 local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
60 if (!local_table)
61 goto fail;
62
63 hlist_add_head_rcu(&local_table->tb_hlist,
64 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
65 hlist_add_head_rcu(&main_table->tb_hlist,
66 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
67 return 0;
68
69fail:
70 fib_free_table(main_table);
71 return -ENOMEM;
72}
73#else
74
75struct fib_table *fib_new_table(struct net *net, u32 id)
76{
77 struct fib_table *tb, *alias = NULL;
78 unsigned int h;
79
80 if (id == 0)
81 id = RT_TABLE_MAIN;
82 tb = fib_get_table(net, id);
83 if (tb)
84 return tb;
85
86 if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules)
87 alias = fib_new_table(net, RT_TABLE_MAIN);
88
89 tb = fib_trie_table(id, alias);
90 if (!tb)
91 return NULL;
92
93 switch (id) {
94 case RT_TABLE_MAIN:
95 rcu_assign_pointer(net->ipv4.fib_main, tb);
96 break;
97 case RT_TABLE_DEFAULT:
98 rcu_assign_pointer(net->ipv4.fib_default, tb);
99 break;
100 default:
101 break;
102 }
103
104 h = id & (FIB_TABLE_HASHSZ - 1);
105 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
106 return tb;
107}
108EXPORT_SYMBOL_GPL(fib_new_table);
109
110/* caller must hold either rtnl or rcu read lock */
111struct fib_table *fib_get_table(struct net *net, u32 id)
112{
113 struct fib_table *tb;
114 struct hlist_head *head;
115 unsigned int h;
116
117 if (id == 0)
118 id = RT_TABLE_MAIN;
119 h = id & (FIB_TABLE_HASHSZ - 1);
120
121 head = &net->ipv4.fib_table_hash[h];
122 hlist_for_each_entry_rcu(tb, head, tb_hlist,
123 lockdep_rtnl_is_held()) {
124 if (tb->tb_id == id)
125 return tb;
126 }
127 return NULL;
128}
129#endif /* CONFIG_IP_MULTIPLE_TABLES */
130
131static void fib_replace_table(struct net *net, struct fib_table *old,
132 struct fib_table *new)
133{
134#ifdef CONFIG_IP_MULTIPLE_TABLES
135 switch (new->tb_id) {
136 case RT_TABLE_MAIN:
137 rcu_assign_pointer(net->ipv4.fib_main, new);
138 break;
139 case RT_TABLE_DEFAULT:
140 rcu_assign_pointer(net->ipv4.fib_default, new);
141 break;
142 default:
143 break;
144 }
145
146#endif
147 /* replace the old table in the hlist */
148 hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
149}
150
151int fib_unmerge(struct net *net)
152{
153 struct fib_table *old, *new, *main_table;
154
155 /* attempt to fetch local table if it has been allocated */
156 old = fib_get_table(net, RT_TABLE_LOCAL);
157 if (!old)
158 return 0;
159
160 new = fib_trie_unmerge(old);
161 if (!new)
162 return -ENOMEM;
163
164 /* table is already unmerged */
165 if (new == old)
166 return 0;
167
168 /* replace merged table with clean table */
169 fib_replace_table(net, old, new);
170 fib_free_table(old);
171
172 /* attempt to fetch main table if it has been allocated */
173 main_table = fib_get_table(net, RT_TABLE_MAIN);
174 if (!main_table)
175 return 0;
176
177 /* flush local entries from main table */
178 fib_table_flush_external(main_table);
179
180 return 0;
181}
182
183void fib_flush(struct net *net)
184{
185 int flushed = 0;
186 unsigned int h;
187
188 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
189 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
190 struct hlist_node *tmp;
191 struct fib_table *tb;
192
193 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
194 flushed += fib_table_flush(net, tb, false);
195 }
196
197 if (flushed)
198 rt_cache_flush(net);
199}
200
201/*
202 * Find address type as if only "dev" was present in the system. If
203 * on_dev is NULL then all interfaces are taken into consideration.
204 */
205static inline unsigned int __inet_dev_addr_type(struct net *net,
206 const struct net_device *dev,
207 __be32 addr, u32 tb_id)
208{
209 struct flowi4 fl4 = { .daddr = addr };
210 struct fib_result res;
211 unsigned int ret = RTN_BROADCAST;
212 struct fib_table *table;
213
214 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
215 return RTN_BROADCAST;
216 if (ipv4_is_multicast(addr))
217 return RTN_MULTICAST;
218
219 rcu_read_lock();
220
221 table = fib_get_table(net, tb_id);
222 if (table) {
223 ret = RTN_UNICAST;
224 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
225 struct fib_nh_common *nhc = fib_info_nhc(res.fi, 0);
226
227 if (!dev || dev == nhc->nhc_dev)
228 ret = res.type;
229 }
230 }
231
232 rcu_read_unlock();
233 return ret;
234}
235
236unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
237{
238 return __inet_dev_addr_type(net, NULL, addr, tb_id);
239}
240EXPORT_SYMBOL(inet_addr_type_table);
241
242unsigned int inet_addr_type(struct net *net, __be32 addr)
243{
244 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
245}
246EXPORT_SYMBOL(inet_addr_type);
247
248unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
249 __be32 addr)
250{
251 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
252
253 return __inet_dev_addr_type(net, dev, addr, rt_table);
254}
255EXPORT_SYMBOL(inet_dev_addr_type);
256
257/* inet_addr_type with dev == NULL but using the table from a dev
258 * if one is associated
259 */
260unsigned int inet_addr_type_dev_table(struct net *net,
261 const struct net_device *dev,
262 __be32 addr)
263{
264 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
265
266 return __inet_dev_addr_type(net, NULL, addr, rt_table);
267}
268EXPORT_SYMBOL(inet_addr_type_dev_table);
269
270__be32 fib_compute_spec_dst(struct sk_buff *skb)
271{
272 struct net_device *dev = skb->dev;
273 struct in_device *in_dev;
274 struct fib_result res;
275 struct rtable *rt;
276 struct net *net;
277 int scope;
278
279 rt = skb_rtable(skb);
280 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
281 RTCF_LOCAL)
282 return ip_hdr(skb)->daddr;
283
284 in_dev = __in_dev_get_rcu(dev);
285
286 net = dev_net(dev);
287
288 scope = RT_SCOPE_UNIVERSE;
289 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
290 bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev);
291 struct flowi4 fl4 = {
292 .flowi4_iif = LOOPBACK_IFINDEX,
293 .flowi4_oif = l3mdev_master_ifindex_rcu(dev),
294 .daddr = ip_hdr(skb)->saddr,
295 .flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
296 .flowi4_scope = scope,
297 .flowi4_mark = vmark ? skb->mark : 0,
298 };
299 if (!fib_lookup(net, &fl4, &res, 0))
300 return fib_result_prefsrc(net, &res);
301 } else {
302 scope = RT_SCOPE_LINK;
303 }
304
305 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
306}
307
308bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev)
309{
310 bool dev_match = false;
311#ifdef CONFIG_IP_ROUTE_MULTIPATH
312 if (unlikely(fi->nh)) {
313 dev_match = nexthop_uses_dev(fi->nh, dev);
314 } else {
315 int ret;
316
317 for (ret = 0; ret < fib_info_num_path(fi); ret++) {
318 const struct fib_nh_common *nhc = fib_info_nhc(fi, ret);
319
320 if (nhc_l3mdev_matches_dev(nhc, dev)) {
321 dev_match = true;
322 break;
323 }
324 }
325 }
326#else
327 if (fib_info_nhc(fi, 0)->nhc_dev == dev)
328 dev_match = true;
329#endif
330
331 return dev_match;
332}
333EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev);
334
335/* Given (packet source, input interface) and optional (dst, oif, tos):
336 * - (main) check, that source is valid i.e. not broadcast or our local
337 * address.
338 * - figure out what "logical" interface this packet arrived
339 * and calculate "specific destination" address.
340 * - check, that packet arrived from expected physical interface.
341 * called with rcu_read_lock()
342 */
343static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
344 u8 tos, int oif, struct net_device *dev,
345 int rpf, struct in_device *idev, u32 *itag)
346{
347 struct net *net = dev_net(dev);
348 struct flow_keys flkeys;
349 int ret, no_addr;
350 struct fib_result res;
351 struct flowi4 fl4;
352 bool dev_match;
353
354 fl4.flowi4_oif = 0;
355 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
356 if (!fl4.flowi4_iif)
357 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
358 fl4.daddr = src;
359 fl4.saddr = dst;
360 fl4.flowi4_tos = tos;
361 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
362 fl4.flowi4_tun_key.tun_id = 0;
363 fl4.flowi4_flags = 0;
364 fl4.flowi4_uid = sock_net_uid(net, NULL);
365 fl4.flowi4_multipath_hash = 0;
366
367 no_addr = idev->ifa_list == NULL;
368
369 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
370 if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) {
371 fl4.flowi4_proto = 0;
372 fl4.fl4_sport = 0;
373 fl4.fl4_dport = 0;
374 }
375
376 if (fib_lookup(net, &fl4, &res, 0))
377 goto last_resort;
378 if (res.type != RTN_UNICAST &&
379 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
380 goto e_inval;
381 fib_combine_itag(itag, &res);
382
383 dev_match = fib_info_nh_uses_dev(res.fi, dev);
384 /* This is not common, loopback packets retain skb_dst so normally they
385 * would not even hit this slow path.
386 */
387 dev_match = dev_match || (res.type == RTN_LOCAL &&
388 dev == net->loopback_dev);
389 if (dev_match) {
390 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
391 return ret;
392 }
393 if (no_addr)
394 goto last_resort;
395 if (rpf == 1)
396 goto e_rpf;
397 fl4.flowi4_oif = dev->ifindex;
398
399 ret = 0;
400 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
401 if (res.type == RTN_UNICAST)
402 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
403 }
404 return ret;
405
406last_resort:
407 if (rpf)
408 goto e_rpf;
409 *itag = 0;
410 return 0;
411
412e_inval:
413 return -EINVAL;
414e_rpf:
415 return -EXDEV;
416}
417
418/* Ignore rp_filter for packets protected by IPsec. */
419int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
420 u8 tos, int oif, struct net_device *dev,
421 struct in_device *idev, u32 *itag)
422{
423 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
424 struct net *net = dev_net(dev);
425
426 if (!r && !fib_num_tclassid_users(net) &&
427 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
428 if (IN_DEV_ACCEPT_LOCAL(idev))
429 goto ok;
430 /* with custom local routes in place, checking local addresses
431 * only will be too optimistic, with custom rules, checking
432 * local addresses only can be too strict, e.g. due to vrf
433 */
434 if (net->ipv4.fib_has_custom_local_routes ||
435 fib4_has_custom_rules(net))
436 goto full_check;
437 if (inet_lookup_ifaddr_rcu(net, src))
438 return -EINVAL;
439
440ok:
441 *itag = 0;
442 return 0;
443 }
444
445full_check:
446 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
447}
448
449static inline __be32 sk_extract_addr(struct sockaddr *addr)
450{
451 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
452}
453
454static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
455{
456 struct nlattr *nla;
457
458 nla = (struct nlattr *) ((char *) mx + len);
459 nla->nla_type = type;
460 nla->nla_len = nla_attr_size(4);
461 *(u32 *) nla_data(nla) = value;
462
463 return len + nla_total_size(4);
464}
465
466static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
467 struct fib_config *cfg)
468{
469 __be32 addr;
470 int plen;
471
472 memset(cfg, 0, sizeof(*cfg));
473 cfg->fc_nlinfo.nl_net = net;
474
475 if (rt->rt_dst.sa_family != AF_INET)
476 return -EAFNOSUPPORT;
477
478 /*
479 * Check mask for validity:
480 * a) it must be contiguous.
481 * b) destination must have all host bits clear.
482 * c) if application forgot to set correct family (AF_INET),
483 * reject request unless it is absolutely clear i.e.
484 * both family and mask are zero.
485 */
486 plen = 32;
487 addr = sk_extract_addr(&rt->rt_dst);
488 if (!(rt->rt_flags & RTF_HOST)) {
489 __be32 mask = sk_extract_addr(&rt->rt_genmask);
490
491 if (rt->rt_genmask.sa_family != AF_INET) {
492 if (mask || rt->rt_genmask.sa_family)
493 return -EAFNOSUPPORT;
494 }
495
496 if (bad_mask(mask, addr))
497 return -EINVAL;
498
499 plen = inet_mask_len(mask);
500 }
501
502 cfg->fc_dst_len = plen;
503 cfg->fc_dst = addr;
504
505 if (cmd != SIOCDELRT) {
506 cfg->fc_nlflags = NLM_F_CREATE;
507 cfg->fc_protocol = RTPROT_BOOT;
508 }
509
510 if (rt->rt_metric)
511 cfg->fc_priority = rt->rt_metric - 1;
512
513 if (rt->rt_flags & RTF_REJECT) {
514 cfg->fc_scope = RT_SCOPE_HOST;
515 cfg->fc_type = RTN_UNREACHABLE;
516 return 0;
517 }
518
519 cfg->fc_scope = RT_SCOPE_NOWHERE;
520 cfg->fc_type = RTN_UNICAST;
521
522 if (rt->rt_dev) {
523 char *colon;
524 struct net_device *dev;
525 char devname[IFNAMSIZ];
526
527 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
528 return -EFAULT;
529
530 devname[IFNAMSIZ-1] = 0;
531 colon = strchr(devname, ':');
532 if (colon)
533 *colon = 0;
534 dev = __dev_get_by_name(net, devname);
535 if (!dev)
536 return -ENODEV;
537 cfg->fc_oif = dev->ifindex;
538 cfg->fc_table = l3mdev_fib_table(dev);
539 if (colon) {
540 const struct in_ifaddr *ifa;
541 struct in_device *in_dev;
542
543 in_dev = __in_dev_get_rtnl(dev);
544 if (!in_dev)
545 return -ENODEV;
546
547 *colon = ':';
548
549 rcu_read_lock();
550 in_dev_for_each_ifa_rcu(ifa, in_dev) {
551 if (strcmp(ifa->ifa_label, devname) == 0)
552 break;
553 }
554 rcu_read_unlock();
555
556 if (!ifa)
557 return -ENODEV;
558 cfg->fc_prefsrc = ifa->ifa_local;
559 }
560 }
561
562 addr = sk_extract_addr(&rt->rt_gateway);
563 if (rt->rt_gateway.sa_family == AF_INET && addr) {
564 unsigned int addr_type;
565
566 cfg->fc_gw4 = addr;
567 cfg->fc_gw_family = AF_INET;
568 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
569 if (rt->rt_flags & RTF_GATEWAY &&
570 addr_type == RTN_UNICAST)
571 cfg->fc_scope = RT_SCOPE_UNIVERSE;
572 }
573
574 if (cmd == SIOCDELRT)
575 return 0;
576
577 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family)
578 return -EINVAL;
579
580 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
581 cfg->fc_scope = RT_SCOPE_LINK;
582
583 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
584 struct nlattr *mx;
585 int len = 0;
586
587 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL);
588 if (!mx)
589 return -ENOMEM;
590
591 if (rt->rt_flags & RTF_MTU)
592 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
593
594 if (rt->rt_flags & RTF_WINDOW)
595 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
596
597 if (rt->rt_flags & RTF_IRTT)
598 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
599
600 cfg->fc_mx = mx;
601 cfg->fc_mx_len = len;
602 }
603
604 return 0;
605}
606
607/*
608 * Handle IP routing ioctl calls.
609 * These are used to manipulate the routing tables
610 */
611int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
612{
613 struct fib_config cfg;
614 int err;
615
616 switch (cmd) {
617 case SIOCADDRT: /* Add a route */
618 case SIOCDELRT: /* Delete a route */
619 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
620 return -EPERM;
621
622 rtnl_lock();
623 err = rtentry_to_fib_config(net, cmd, rt, &cfg);
624 if (err == 0) {
625 struct fib_table *tb;
626
627 if (cmd == SIOCDELRT) {
628 tb = fib_get_table(net, cfg.fc_table);
629 if (tb)
630 err = fib_table_delete(net, tb, &cfg,
631 NULL);
632 else
633 err = -ESRCH;
634 } else {
635 tb = fib_new_table(net, cfg.fc_table);
636 if (tb)
637 err = fib_table_insert(net, tb,
638 &cfg, NULL);
639 else
640 err = -ENOBUFS;
641 }
642
643 /* allocated by rtentry_to_fib_config() */
644 kfree(cfg.fc_mx);
645 }
646 rtnl_unlock();
647 return err;
648 }
649 return -EINVAL;
650}
651
652const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
653 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 },
654 [RTA_DST] = { .type = NLA_U32 },
655 [RTA_SRC] = { .type = NLA_U32 },
656 [RTA_IIF] = { .type = NLA_U32 },
657 [RTA_OIF] = { .type = NLA_U32 },
658 [RTA_GATEWAY] = { .type = NLA_U32 },
659 [RTA_PRIORITY] = { .type = NLA_U32 },
660 [RTA_PREFSRC] = { .type = NLA_U32 },
661 [RTA_METRICS] = { .type = NLA_NESTED },
662 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
663 [RTA_FLOW] = { .type = NLA_U32 },
664 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
665 [RTA_ENCAP] = { .type = NLA_NESTED },
666 [RTA_UID] = { .type = NLA_U32 },
667 [RTA_MARK] = { .type = NLA_U32 },
668 [RTA_TABLE] = { .type = NLA_U32 },
669 [RTA_IP_PROTO] = { .type = NLA_U8 },
670 [RTA_SPORT] = { .type = NLA_U16 },
671 [RTA_DPORT] = { .type = NLA_U16 },
672 [RTA_NH_ID] = { .type = NLA_U32 },
673};
674
675int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
676 struct netlink_ext_ack *extack)
677{
678 struct rtvia *via;
679 int alen;
680
681 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
682 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA");
683 return -EINVAL;
684 }
685
686 via = nla_data(nla);
687 alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr);
688
689 switch (via->rtvia_family) {
690 case AF_INET:
691 if (alen != sizeof(__be32)) {
692 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA");
693 return -EINVAL;
694 }
695 cfg->fc_gw_family = AF_INET;
696 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr);
697 break;
698 case AF_INET6:
699#ifdef CONFIG_IPV6
700 if (alen != sizeof(struct in6_addr)) {
701 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA");
702 return -EINVAL;
703 }
704 cfg->fc_gw_family = AF_INET6;
705 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr);
706#else
707 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
708 return -EINVAL;
709#endif
710 break;
711 default:
712 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA");
713 return -EINVAL;
714 }
715
716 return 0;
717}
718
719static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
720 struct nlmsghdr *nlh, struct fib_config *cfg,
721 struct netlink_ext_ack *extack)
722{
723 bool has_gw = false, has_via = false;
724 struct nlattr *attr;
725 int err, remaining;
726 struct rtmsg *rtm;
727
728 err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
729 rtm_ipv4_policy, extack);
730 if (err < 0)
731 goto errout;
732
733 memset(cfg, 0, sizeof(*cfg));
734
735 rtm = nlmsg_data(nlh);
736 cfg->fc_dst_len = rtm->rtm_dst_len;
737 cfg->fc_tos = rtm->rtm_tos;
738 cfg->fc_table = rtm->rtm_table;
739 cfg->fc_protocol = rtm->rtm_protocol;
740 cfg->fc_scope = rtm->rtm_scope;
741 cfg->fc_type = rtm->rtm_type;
742 cfg->fc_flags = rtm->rtm_flags;
743 cfg->fc_nlflags = nlh->nlmsg_flags;
744
745 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
746 cfg->fc_nlinfo.nlh = nlh;
747 cfg->fc_nlinfo.nl_net = net;
748
749 if (cfg->fc_type > RTN_MAX) {
750 NL_SET_ERR_MSG(extack, "Invalid route type");
751 err = -EINVAL;
752 goto errout;
753 }
754
755 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
756 switch (nla_type(attr)) {
757 case RTA_DST:
758 cfg->fc_dst = nla_get_be32(attr);
759 break;
760 case RTA_OIF:
761 cfg->fc_oif = nla_get_u32(attr);
762 break;
763 case RTA_GATEWAY:
764 has_gw = true;
765 cfg->fc_gw4 = nla_get_be32(attr);
766 if (cfg->fc_gw4)
767 cfg->fc_gw_family = AF_INET;
768 break;
769 case RTA_VIA:
770 has_via = true;
771 err = fib_gw_from_via(cfg, attr, extack);
772 if (err)
773 goto errout;
774 break;
775 case RTA_PRIORITY:
776 cfg->fc_priority = nla_get_u32(attr);
777 break;
778 case RTA_PREFSRC:
779 cfg->fc_prefsrc = nla_get_be32(attr);
780 break;
781 case RTA_METRICS:
782 cfg->fc_mx = nla_data(attr);
783 cfg->fc_mx_len = nla_len(attr);
784 break;
785 case RTA_MULTIPATH:
786 err = lwtunnel_valid_encap_type_attr(nla_data(attr),
787 nla_len(attr),
788 extack);
789 if (err < 0)
790 goto errout;
791 cfg->fc_mp = nla_data(attr);
792 cfg->fc_mp_len = nla_len(attr);
793 break;
794 case RTA_FLOW:
795 cfg->fc_flow = nla_get_u32(attr);
796 break;
797 case RTA_TABLE:
798 cfg->fc_table = nla_get_u32(attr);
799 break;
800 case RTA_ENCAP:
801 cfg->fc_encap = attr;
802 break;
803 case RTA_ENCAP_TYPE:
804 cfg->fc_encap_type = nla_get_u16(attr);
805 err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
806 extack);
807 if (err < 0)
808 goto errout;
809 break;
810 case RTA_NH_ID:
811 cfg->fc_nh_id = nla_get_u32(attr);
812 break;
813 }
814 }
815
816 if (cfg->fc_nh_id) {
817 if (cfg->fc_oif || cfg->fc_gw_family ||
818 cfg->fc_encap || cfg->fc_mp) {
819 NL_SET_ERR_MSG(extack,
820 "Nexthop specification and nexthop id are mutually exclusive");
821 return -EINVAL;
822 }
823 }
824
825 if (has_gw && has_via) {
826 NL_SET_ERR_MSG(extack,
827 "Nexthop configuration can not contain both GATEWAY and VIA");
828 goto errout;
829 }
830
831 return 0;
832errout:
833 return err;
834}
835
836static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
837 struct netlink_ext_ack *extack)
838{
839 struct net *net = sock_net(skb->sk);
840 struct fib_config cfg;
841 struct fib_table *tb;
842 int err;
843
844 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
845 if (err < 0)
846 goto errout;
847
848 if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) {
849 NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
850 err = -EINVAL;
851 goto errout;
852 }
853
854 tb = fib_get_table(net, cfg.fc_table);
855 if (!tb) {
856 NL_SET_ERR_MSG(extack, "FIB table does not exist");
857 err = -ESRCH;
858 goto errout;
859 }
860
861 err = fib_table_delete(net, tb, &cfg, extack);
862errout:
863 return err;
864}
865
866static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
867 struct netlink_ext_ack *extack)
868{
869 struct net *net = sock_net(skb->sk);
870 struct fib_config cfg;
871 struct fib_table *tb;
872 int err;
873
874 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
875 if (err < 0)
876 goto errout;
877
878 tb = fib_new_table(net, cfg.fc_table);
879 if (!tb) {
880 err = -ENOBUFS;
881 goto errout;
882 }
883
884 err = fib_table_insert(net, tb, &cfg, extack);
885 if (!err && cfg.fc_type == RTN_LOCAL)
886 net->ipv4.fib_has_custom_local_routes = true;
887errout:
888 return err;
889}
890
891int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
892 struct fib_dump_filter *filter,
893 struct netlink_callback *cb)
894{
895 struct netlink_ext_ack *extack = cb->extack;
896 struct nlattr *tb[RTA_MAX + 1];
897 struct rtmsg *rtm;
898 int err, i;
899
900 ASSERT_RTNL();
901
902 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
903 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request");
904 return -EINVAL;
905 }
906
907 rtm = nlmsg_data(nlh);
908 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos ||
909 rtm->rtm_scope) {
910 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request");
911 return -EINVAL;
912 }
913
914 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) {
915 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request");
916 return -EINVAL;
917 }
918 if (rtm->rtm_flags & RTM_F_CLONED)
919 filter->dump_routes = false;
920 else
921 filter->dump_exceptions = false;
922
923 filter->flags = rtm->rtm_flags;
924 filter->protocol = rtm->rtm_protocol;
925 filter->rt_type = rtm->rtm_type;
926 filter->table_id = rtm->rtm_table;
927
928 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
929 rtm_ipv4_policy, extack);
930 if (err < 0)
931 return err;
932
933 for (i = 0; i <= RTA_MAX; ++i) {
934 int ifindex;
935
936 if (!tb[i])
937 continue;
938
939 switch (i) {
940 case RTA_TABLE:
941 filter->table_id = nla_get_u32(tb[i]);
942 break;
943 case RTA_OIF:
944 ifindex = nla_get_u32(tb[i]);
945 filter->dev = __dev_get_by_index(net, ifindex);
946 if (!filter->dev)
947 return -ENODEV;
948 break;
949 default:
950 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
951 return -EINVAL;
952 }
953 }
954
955 if (filter->flags || filter->protocol || filter->rt_type ||
956 filter->table_id || filter->dev) {
957 filter->filter_set = 1;
958 cb->answer_flags = NLM_F_DUMP_FILTERED;
959 }
960
961 return 0;
962}
963EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req);
964
965static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
966{
967 struct fib_dump_filter filter = { .dump_routes = true,
968 .dump_exceptions = true };
969 const struct nlmsghdr *nlh = cb->nlh;
970 struct net *net = sock_net(skb->sk);
971 unsigned int h, s_h;
972 unsigned int e = 0, s_e;
973 struct fib_table *tb;
974 struct hlist_head *head;
975 int dumped = 0, err;
976
977 if (cb->strict_check) {
978 err = ip_valid_fib_dump_req(net, nlh, &filter, cb);
979 if (err < 0)
980 return err;
981 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
982 struct rtmsg *rtm = nlmsg_data(nlh);
983
984 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED);
985 }
986
987 /* ipv4 does not use prefix flag */
988 if (filter.flags & RTM_F_PREFIX)
989 return skb->len;
990
991 if (filter.table_id) {
992 tb = fib_get_table(net, filter.table_id);
993 if (!tb) {
994 if (rtnl_msg_family(cb->nlh) != PF_INET)
995 return skb->len;
996
997 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist");
998 return -ENOENT;
999 }
1000
1001 rcu_read_lock();
1002 err = fib_table_dump(tb, skb, cb, &filter);
1003 rcu_read_unlock();
1004 return skb->len ? : err;
1005 }
1006
1007 s_h = cb->args[0];
1008 s_e = cb->args[1];
1009
1010 rcu_read_lock();
1011
1012 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
1013 e = 0;
1014 head = &net->ipv4.fib_table_hash[h];
1015 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
1016 if (e < s_e)
1017 goto next;
1018 if (dumped)
1019 memset(&cb->args[2], 0, sizeof(cb->args) -
1020 2 * sizeof(cb->args[0]));
1021 err = fib_table_dump(tb, skb, cb, &filter);
1022 if (err < 0) {
1023 if (likely(skb->len))
1024 goto out;
1025
1026 goto out_err;
1027 }
1028 dumped = 1;
1029next:
1030 e++;
1031 }
1032 }
1033out:
1034 err = skb->len;
1035out_err:
1036 rcu_read_unlock();
1037
1038 cb->args[1] = e;
1039 cb->args[0] = h;
1040
1041 return err;
1042}
1043
1044/* Prepare and feed intra-kernel routing request.
1045 * Really, it should be netlink message, but :-( netlink
1046 * can be not configured, so that we feed it directly
1047 * to fib engine. It is legal, because all events occur
1048 * only when netlink is already locked.
1049 */
1050static void fib_magic(int cmd, int type, __be32 dst, int dst_len,
1051 struct in_ifaddr *ifa, u32 rt_priority)
1052{
1053 struct net *net = dev_net(ifa->ifa_dev->dev);
1054 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
1055 struct fib_table *tb;
1056 struct fib_config cfg = {
1057 .fc_protocol = RTPROT_KERNEL,
1058 .fc_type = type,
1059 .fc_dst = dst,
1060 .fc_dst_len = dst_len,
1061 .fc_priority = rt_priority,
1062 .fc_prefsrc = ifa->ifa_local,
1063 .fc_oif = ifa->ifa_dev->dev->ifindex,
1064 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
1065 .fc_nlinfo = {
1066 .nl_net = net,
1067 },
1068 };
1069
1070 if (!tb_id)
1071 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
1072
1073 tb = fib_new_table(net, tb_id);
1074 if (!tb)
1075 return;
1076
1077 cfg.fc_table = tb->tb_id;
1078
1079 if (type != RTN_LOCAL)
1080 cfg.fc_scope = RT_SCOPE_LINK;
1081 else
1082 cfg.fc_scope = RT_SCOPE_HOST;
1083
1084 if (cmd == RTM_NEWROUTE)
1085 fib_table_insert(net, tb, &cfg, NULL);
1086 else
1087 fib_table_delete(net, tb, &cfg, NULL);
1088}
1089
1090void fib_add_ifaddr(struct in_ifaddr *ifa)
1091{
1092 struct in_device *in_dev = ifa->ifa_dev;
1093 struct net_device *dev = in_dev->dev;
1094 struct in_ifaddr *prim = ifa;
1095 __be32 mask = ifa->ifa_mask;
1096 __be32 addr = ifa->ifa_local;
1097 __be32 prefix = ifa->ifa_address & mask;
1098
1099 if (ifa->ifa_flags & IFA_F_SECONDARY) {
1100 prim = inet_ifa_byprefix(in_dev, prefix, mask);
1101 if (!prim) {
1102 pr_warn("%s: bug: prim == NULL\n", __func__);
1103 return;
1104 }
1105 }
1106
1107 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0);
1108
1109 if (!(dev->flags & IFF_UP))
1110 return;
1111
1112 /* Add broadcast address, if it is explicitly assigned. */
1113 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
1114 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1115 prim, 0);
1116
1117 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
1118 (prefix != addr || ifa->ifa_prefixlen < 32)) {
1119 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1120 fib_magic(RTM_NEWROUTE,
1121 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1122 prefix, ifa->ifa_prefixlen, prim,
1123 ifa->ifa_rt_priority);
1124
1125 /* Add network specific broadcasts, when it takes a sense */
1126 if (ifa->ifa_prefixlen < 31) {
1127 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32,
1128 prim, 0);
1129 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
1130 32, prim, 0);
1131 }
1132 }
1133}
1134
1135void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric)
1136{
1137 __be32 prefix = ifa->ifa_address & ifa->ifa_mask;
1138 struct in_device *in_dev = ifa->ifa_dev;
1139 struct net_device *dev = in_dev->dev;
1140
1141 if (!(dev->flags & IFF_UP) ||
1142 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) ||
1143 ipv4_is_zeronet(prefix) ||
1144 (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32))
1145 return;
1146
1147 /* add the new */
1148 fib_magic(RTM_NEWROUTE,
1149 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1150 prefix, ifa->ifa_prefixlen, ifa, new_metric);
1151
1152 /* delete the old */
1153 fib_magic(RTM_DELROUTE,
1154 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1155 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority);
1156}
1157
1158/* Delete primary or secondary address.
1159 * Optionally, on secondary address promotion consider the addresses
1160 * from subnet iprim as deleted, even if they are in device list.
1161 * In this case the secondary ifa can be in device list.
1162 */
1163void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
1164{
1165 struct in_device *in_dev = ifa->ifa_dev;
1166 struct net_device *dev = in_dev->dev;
1167 struct in_ifaddr *ifa1;
1168 struct in_ifaddr *prim = ifa, *prim1 = NULL;
1169 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
1170 __be32 any = ifa->ifa_address & ifa->ifa_mask;
1171#define LOCAL_OK 1
1172#define BRD_OK 2
1173#define BRD0_OK 4
1174#define BRD1_OK 8
1175 unsigned int ok = 0;
1176 int subnet = 0; /* Primary network */
1177 int gone = 1; /* Address is missing */
1178 int same_prefsrc = 0; /* Another primary with same IP */
1179
1180 if (ifa->ifa_flags & IFA_F_SECONDARY) {
1181 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
1182 if (!prim) {
1183 /* if the device has been deleted, we don't perform
1184 * address promotion
1185 */
1186 if (!in_dev->dead)
1187 pr_warn("%s: bug: prim == NULL\n", __func__);
1188 return;
1189 }
1190 if (iprim && iprim != prim) {
1191 pr_warn("%s: bug: iprim != prim\n", __func__);
1192 return;
1193 }
1194 } else if (!ipv4_is_zeronet(any) &&
1195 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
1196 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1197 fib_magic(RTM_DELROUTE,
1198 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1199 any, ifa->ifa_prefixlen, prim, 0);
1200 subnet = 1;
1201 }
1202
1203 if (in_dev->dead)
1204 goto no_promotions;
1205
1206 /* Deletion is more complicated than add.
1207 * We should take care of not to delete too much :-)
1208 *
1209 * Scan address list to be sure that addresses are really gone.
1210 */
1211 rcu_read_lock();
1212 in_dev_for_each_ifa_rcu(ifa1, in_dev) {
1213 if (ifa1 == ifa) {
1214 /* promotion, keep the IP */
1215 gone = 0;
1216 continue;
1217 }
1218 /* Ignore IFAs from our subnet */
1219 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
1220 inet_ifa_match(ifa1->ifa_address, iprim))
1221 continue;
1222
1223 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
1224 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
1225 /* Another address from our subnet? */
1226 if (ifa1->ifa_mask == prim->ifa_mask &&
1227 inet_ifa_match(ifa1->ifa_address, prim))
1228 prim1 = prim;
1229 else {
1230 /* We reached the secondaries, so
1231 * same_prefsrc should be determined.
1232 */
1233 if (!same_prefsrc)
1234 continue;
1235 /* Search new prim1 if ifa1 is not
1236 * using the current prim1
1237 */
1238 if (!prim1 ||
1239 ifa1->ifa_mask != prim1->ifa_mask ||
1240 !inet_ifa_match(ifa1->ifa_address, prim1))
1241 prim1 = inet_ifa_byprefix(in_dev,
1242 ifa1->ifa_address,
1243 ifa1->ifa_mask);
1244 if (!prim1)
1245 continue;
1246 if (prim1->ifa_local != prim->ifa_local)
1247 continue;
1248 }
1249 } else {
1250 if (prim->ifa_local != ifa1->ifa_local)
1251 continue;
1252 prim1 = ifa1;
1253 if (prim != prim1)
1254 same_prefsrc = 1;
1255 }
1256 if (ifa->ifa_local == ifa1->ifa_local)
1257 ok |= LOCAL_OK;
1258 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1259 ok |= BRD_OK;
1260 if (brd == ifa1->ifa_broadcast)
1261 ok |= BRD1_OK;
1262 if (any == ifa1->ifa_broadcast)
1263 ok |= BRD0_OK;
1264 /* primary has network specific broadcasts */
1265 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1266 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1267 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1268
1269 if (!ipv4_is_zeronet(any1)) {
1270 if (ifa->ifa_broadcast == brd1 ||
1271 ifa->ifa_broadcast == any1)
1272 ok |= BRD_OK;
1273 if (brd == brd1 || brd == any1)
1274 ok |= BRD1_OK;
1275 if (any == brd1 || any == any1)
1276 ok |= BRD0_OK;
1277 }
1278 }
1279 }
1280 rcu_read_unlock();
1281
1282no_promotions:
1283 if (!(ok & BRD_OK))
1284 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1285 prim, 0);
1286 if (subnet && ifa->ifa_prefixlen < 31) {
1287 if (!(ok & BRD1_OK))
1288 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32,
1289 prim, 0);
1290 if (!(ok & BRD0_OK))
1291 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32,
1292 prim, 0);
1293 }
1294 if (!(ok & LOCAL_OK)) {
1295 unsigned int addr_type;
1296
1297 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0);
1298
1299 /* Check, that this local address finally disappeared. */
1300 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1301 ifa->ifa_local);
1302 if (gone && addr_type != RTN_LOCAL) {
1303 /* And the last, but not the least thing.
1304 * We must flush stray FIB entries.
1305 *
1306 * First of all, we scan fib_info list searching
1307 * for stray nexthop entries, then ignite fib_flush.
1308 */
1309 if (fib_sync_down_addr(dev, ifa->ifa_local))
1310 fib_flush(dev_net(dev));
1311 }
1312 }
1313#undef LOCAL_OK
1314#undef BRD_OK
1315#undef BRD0_OK
1316#undef BRD1_OK
1317}
1318
1319static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1320{
1321
1322 struct fib_result res;
1323 struct flowi4 fl4 = {
1324 .flowi4_mark = frn->fl_mark,
1325 .daddr = frn->fl_addr,
1326 .flowi4_tos = frn->fl_tos,
1327 .flowi4_scope = frn->fl_scope,
1328 };
1329 struct fib_table *tb;
1330
1331 rcu_read_lock();
1332
1333 tb = fib_get_table(net, frn->tb_id_in);
1334
1335 frn->err = -ENOENT;
1336 if (tb) {
1337 local_bh_disable();
1338
1339 frn->tb_id = tb->tb_id;
1340 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1341
1342 if (!frn->err) {
1343 frn->prefixlen = res.prefixlen;
1344 frn->nh_sel = res.nh_sel;
1345 frn->type = res.type;
1346 frn->scope = res.scope;
1347 }
1348 local_bh_enable();
1349 }
1350
1351 rcu_read_unlock();
1352}
1353
1354static void nl_fib_input(struct sk_buff *skb)
1355{
1356 struct net *net;
1357 struct fib_result_nl *frn;
1358 struct nlmsghdr *nlh;
1359 u32 portid;
1360
1361 net = sock_net(skb->sk);
1362 nlh = nlmsg_hdr(skb);
1363 if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1364 skb->len < nlh->nlmsg_len ||
1365 nlmsg_len(nlh) < sizeof(*frn))
1366 return;
1367
1368 skb = netlink_skb_clone(skb, GFP_KERNEL);
1369 if (!skb)
1370 return;
1371 nlh = nlmsg_hdr(skb);
1372
1373 frn = (struct fib_result_nl *) nlmsg_data(nlh);
1374 nl_fib_lookup(net, frn);
1375
1376 portid = NETLINK_CB(skb).portid; /* netlink portid */
1377 NETLINK_CB(skb).portid = 0; /* from kernel */
1378 NETLINK_CB(skb).dst_group = 0; /* unicast */
1379 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1380}
1381
1382static int __net_init nl_fib_lookup_init(struct net *net)
1383{
1384 struct sock *sk;
1385 struct netlink_kernel_cfg cfg = {
1386 .input = nl_fib_input,
1387 };
1388
1389 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1390 if (!sk)
1391 return -EAFNOSUPPORT;
1392 net->ipv4.fibnl = sk;
1393 return 0;
1394}
1395
1396static void nl_fib_lookup_exit(struct net *net)
1397{
1398 netlink_kernel_release(net->ipv4.fibnl);
1399 net->ipv4.fibnl = NULL;
1400}
1401
1402static void fib_disable_ip(struct net_device *dev, unsigned long event,
1403 bool force)
1404{
1405 if (fib_sync_down_dev(dev, event, force))
1406 fib_flush(dev_net(dev));
1407 else
1408 rt_cache_flush(dev_net(dev));
1409 arp_ifdown(dev);
1410}
1411
1412static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1413{
1414 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1415 struct net_device *dev = ifa->ifa_dev->dev;
1416 struct net *net = dev_net(dev);
1417
1418 switch (event) {
1419 case NETDEV_UP:
1420 fib_add_ifaddr(ifa);
1421#ifdef CONFIG_IP_ROUTE_MULTIPATH
1422 fib_sync_up(dev, RTNH_F_DEAD);
1423#endif
1424 atomic_inc(&net->ipv4.dev_addr_genid);
1425 rt_cache_flush(dev_net(dev));
1426 break;
1427 case NETDEV_DOWN:
1428 fib_del_ifaddr(ifa, NULL);
1429 atomic_inc(&net->ipv4.dev_addr_genid);
1430 if (!ifa->ifa_dev->ifa_list) {
1431 /* Last address was deleted from this interface.
1432 * Disable IP.
1433 */
1434 fib_disable_ip(dev, event, true);
1435 } else {
1436 rt_cache_flush(dev_net(dev));
1437 }
1438 break;
1439 }
1440 return NOTIFY_DONE;
1441}
1442
1443static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1444{
1445 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1446 struct netdev_notifier_changeupper_info *upper_info = ptr;
1447 struct netdev_notifier_info_ext *info_ext = ptr;
1448 struct in_device *in_dev;
1449 struct net *net = dev_net(dev);
1450 struct in_ifaddr *ifa;
1451 unsigned int flags;
1452
1453 if (event == NETDEV_UNREGISTER) {
1454 fib_disable_ip(dev, event, true);
1455 rt_flush_dev(dev);
1456 return NOTIFY_DONE;
1457 }
1458
1459 in_dev = __in_dev_get_rtnl(dev);
1460 if (!in_dev)
1461 return NOTIFY_DONE;
1462
1463 switch (event) {
1464 case NETDEV_UP:
1465 in_dev_for_each_ifa_rtnl(ifa, in_dev) {
1466 fib_add_ifaddr(ifa);
1467 }
1468#ifdef CONFIG_IP_ROUTE_MULTIPATH
1469 fib_sync_up(dev, RTNH_F_DEAD);
1470#endif
1471 atomic_inc(&net->ipv4.dev_addr_genid);
1472 rt_cache_flush(net);
1473 break;
1474 case NETDEV_DOWN:
1475 fib_disable_ip(dev, event, false);
1476 break;
1477 case NETDEV_CHANGE:
1478 flags = dev_get_flags(dev);
1479 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1480 fib_sync_up(dev, RTNH_F_LINKDOWN);
1481 else
1482 fib_sync_down_dev(dev, event, false);
1483 rt_cache_flush(net);
1484 break;
1485 case NETDEV_CHANGEMTU:
1486 fib_sync_mtu(dev, info_ext->ext.mtu);
1487 rt_cache_flush(net);
1488 break;
1489 case NETDEV_CHANGEUPPER:
1490 upper_info = ptr;
1491 /* flush all routes if dev is linked to or unlinked from
1492 * an L3 master device (e.g., VRF)
1493 */
1494 if (upper_info->upper_dev &&
1495 netif_is_l3_master(upper_info->upper_dev))
1496 fib_disable_ip(dev, NETDEV_DOWN, true);
1497 break;
1498 }
1499 return NOTIFY_DONE;
1500}
1501
1502static struct notifier_block fib_inetaddr_notifier = {
1503 .notifier_call = fib_inetaddr_event,
1504};
1505
1506static struct notifier_block fib_netdev_notifier = {
1507 .notifier_call = fib_netdev_event,
1508};
1509
1510static int __net_init ip_fib_net_init(struct net *net)
1511{
1512 int err;
1513 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1514
1515 err = fib4_notifier_init(net);
1516 if (err)
1517 return err;
1518
1519 /* Avoid false sharing : Use at least a full cache line */
1520 size = max_t(size_t, size, L1_CACHE_BYTES);
1521
1522 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1523 if (!net->ipv4.fib_table_hash) {
1524 err = -ENOMEM;
1525 goto err_table_hash_alloc;
1526 }
1527
1528 err = fib4_rules_init(net);
1529 if (err < 0)
1530 goto err_rules_init;
1531 return 0;
1532
1533err_rules_init:
1534 kfree(net->ipv4.fib_table_hash);
1535err_table_hash_alloc:
1536 fib4_notifier_exit(net);
1537 return err;
1538}
1539
1540static void ip_fib_net_exit(struct net *net)
1541{
1542 int i;
1543
1544 rtnl_lock();
1545#ifdef CONFIG_IP_MULTIPLE_TABLES
1546 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1547 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1548#endif
1549 /* Destroy the tables in reverse order to guarantee that the
1550 * local table, ID 255, is destroyed before the main table, ID
1551 * 254. This is necessary as the local table may contain
1552 * references to data contained in the main table.
1553 */
1554 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1555 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1556 struct hlist_node *tmp;
1557 struct fib_table *tb;
1558
1559 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1560 hlist_del(&tb->tb_hlist);
1561 fib_table_flush(net, tb, true);
1562 fib_free_table(tb);
1563 }
1564 }
1565
1566#ifdef CONFIG_IP_MULTIPLE_TABLES
1567 fib4_rules_exit(net);
1568#endif
1569 rtnl_unlock();
1570 kfree(net->ipv4.fib_table_hash);
1571 fib4_notifier_exit(net);
1572}
1573
1574static int __net_init fib_net_init(struct net *net)
1575{
1576 int error;
1577
1578#ifdef CONFIG_IP_ROUTE_CLASSID
1579 net->ipv4.fib_num_tclassid_users = 0;
1580#endif
1581 error = ip_fib_net_init(net);
1582 if (error < 0)
1583 goto out;
1584 error = nl_fib_lookup_init(net);
1585 if (error < 0)
1586 goto out_nlfl;
1587 error = fib_proc_init(net);
1588 if (error < 0)
1589 goto out_proc;
1590out:
1591 return error;
1592
1593out_proc:
1594 nl_fib_lookup_exit(net);
1595out_nlfl:
1596 ip_fib_net_exit(net);
1597 goto out;
1598}
1599
1600static void __net_exit fib_net_exit(struct net *net)
1601{
1602 fib_proc_exit(net);
1603 nl_fib_lookup_exit(net);
1604 ip_fib_net_exit(net);
1605}
1606
1607static struct pernet_operations fib_net_ops = {
1608 .init = fib_net_init,
1609 .exit = fib_net_exit,
1610};
1611
1612void __init ip_fib_init(void)
1613{
1614 fib_trie_init();
1615
1616 register_pernet_subsys(&fib_net_ops);
1617
1618 register_netdevice_notifier(&fib_netdev_notifier);
1619 register_inetaddr_notifier(&fib_inetaddr_notifier);
1620
1621 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0);
1622 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0);
1623 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0);
1624}