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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
74static bool fib4_has_custom_rules(struct net *net)
75{
76 return false;
77}
78#else
79
80struct fib_table *fib_new_table(struct net *net, u32 id)
81{
82 struct fib_table *tb, *alias = NULL;
83 unsigned int h;
84
85 if (id == 0)
86 id = RT_TABLE_MAIN;
87 tb = fib_get_table(net, id);
88 if (tb)
89 return tb;
90
91 if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules)
92 alias = fib_new_table(net, RT_TABLE_MAIN);
93
94 tb = fib_trie_table(id, alias);
95 if (!tb)
96 return NULL;
97
98 switch (id) {
99 case RT_TABLE_MAIN:
100 rcu_assign_pointer(net->ipv4.fib_main, tb);
101 break;
102 case RT_TABLE_DEFAULT:
103 rcu_assign_pointer(net->ipv4.fib_default, tb);
104 break;
105 default:
106 break;
107 }
108
109 h = id & (FIB_TABLE_HASHSZ - 1);
110 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
111 return tb;
112}
113EXPORT_SYMBOL_GPL(fib_new_table);
114
115/* caller must hold either rtnl or rcu read lock */
116struct fib_table *fib_get_table(struct net *net, u32 id)
117{
118 struct fib_table *tb;
119 struct hlist_head *head;
120 unsigned int h;
121
122 if (id == 0)
123 id = RT_TABLE_MAIN;
124 h = id & (FIB_TABLE_HASHSZ - 1);
125
126 head = &net->ipv4.fib_table_hash[h];
127 hlist_for_each_entry_rcu(tb, head, tb_hlist,
128 lockdep_rtnl_is_held()) {
129 if (tb->tb_id == id)
130 return tb;
131 }
132 return NULL;
133}
134
135static bool fib4_has_custom_rules(struct net *net)
136{
137 return net->ipv4.fib_has_custom_rules;
138}
139#endif /* CONFIG_IP_MULTIPLE_TABLES */
140
141static void fib_replace_table(struct net *net, struct fib_table *old,
142 struct fib_table *new)
143{
144#ifdef CONFIG_IP_MULTIPLE_TABLES
145 switch (new->tb_id) {
146 case RT_TABLE_MAIN:
147 rcu_assign_pointer(net->ipv4.fib_main, new);
148 break;
149 case RT_TABLE_DEFAULT:
150 rcu_assign_pointer(net->ipv4.fib_default, new);
151 break;
152 default:
153 break;
154 }
155
156#endif
157 /* replace the old table in the hlist */
158 hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
159}
160
161int fib_unmerge(struct net *net)
162{
163 struct fib_table *old, *new, *main_table;
164
165 /* attempt to fetch local table if it has been allocated */
166 old = fib_get_table(net, RT_TABLE_LOCAL);
167 if (!old)
168 return 0;
169
170 new = fib_trie_unmerge(old);
171 if (!new)
172 return -ENOMEM;
173
174 /* table is already unmerged */
175 if (new == old)
176 return 0;
177
178 /* replace merged table with clean table */
179 fib_replace_table(net, old, new);
180 fib_free_table(old);
181
182 /* attempt to fetch main table if it has been allocated */
183 main_table = fib_get_table(net, RT_TABLE_MAIN);
184 if (!main_table)
185 return 0;
186
187 /* flush local entries from main table */
188 fib_table_flush_external(main_table);
189
190 return 0;
191}
192
193void fib_flush(struct net *net)
194{
195 int flushed = 0;
196 unsigned int h;
197
198 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
199 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
200 struct hlist_node *tmp;
201 struct fib_table *tb;
202
203 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
204 flushed += fib_table_flush(net, tb, false);
205 }
206
207 if (flushed)
208 rt_cache_flush(net);
209}
210
211/*
212 * Find address type as if only "dev" was present in the system. If
213 * on_dev is NULL then all interfaces are taken into consideration.
214 */
215static inline unsigned int __inet_dev_addr_type(struct net *net,
216 const struct net_device *dev,
217 __be32 addr, u32 tb_id)
218{
219 struct flowi4 fl4 = { .daddr = addr };
220 struct fib_result res;
221 unsigned int ret = RTN_BROADCAST;
222 struct fib_table *table;
223
224 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
225 return RTN_BROADCAST;
226 if (ipv4_is_multicast(addr))
227 return RTN_MULTICAST;
228
229 rcu_read_lock();
230
231 table = fib_get_table(net, tb_id);
232 if (table) {
233 ret = RTN_UNICAST;
234 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
235 struct fib_nh_common *nhc = fib_info_nhc(res.fi, 0);
236
237 if (!dev || dev == nhc->nhc_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_result_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 < fib_info_num_path(fi); ret++) {
325 const struct fib_nh_common *nhc = fib_info_nhc(fi, ret);
326
327 if (nhc->nhc_dev == dev) {
328 dev_match = true;
329 break;
330 } else if (l3mdev_master_ifindex_rcu(nhc->nhc_dev) == dev->ifindex) {
331 dev_match = true;
332 break;
333 }
334 }
335#else
336 if (fib_info_nhc(fi, 0)->nhc_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 /* This is not common, loopback packets retain skb_dst so normally they
393 * would not even hit this slow path.
394 */
395 dev_match = dev_match || (res.type == RTN_LOCAL &&
396 dev == net->loopback_dev);
397 if (dev_match) {
398 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
399 return ret;
400 }
401 if (no_addr)
402 goto last_resort;
403 if (rpf == 1)
404 goto e_rpf;
405 fl4.flowi4_oif = dev->ifindex;
406
407 ret = 0;
408 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
409 if (res.type == RTN_UNICAST)
410 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
411 }
412 return ret;
413
414last_resort:
415 if (rpf)
416 goto e_rpf;
417 *itag = 0;
418 return 0;
419
420e_inval:
421 return -EINVAL;
422e_rpf:
423 return -EXDEV;
424}
425
426/* Ignore rp_filter for packets protected by IPsec. */
427int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
428 u8 tos, int oif, struct net_device *dev,
429 struct in_device *idev, u32 *itag)
430{
431 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
432 struct net *net = dev_net(dev);
433
434 if (!r && !fib_num_tclassid_users(net) &&
435 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
436 if (IN_DEV_ACCEPT_LOCAL(idev))
437 goto ok;
438 /* with custom local routes in place, checking local addresses
439 * only will be too optimistic, with custom rules, checking
440 * local addresses only can be too strict, e.g. due to vrf
441 */
442 if (net->ipv4.fib_has_custom_local_routes ||
443 fib4_has_custom_rules(net))
444 goto full_check;
445 if (inet_lookup_ifaddr_rcu(net, src))
446 return -EINVAL;
447
448ok:
449 *itag = 0;
450 return 0;
451 }
452
453full_check:
454 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
455}
456
457static inline __be32 sk_extract_addr(struct sockaddr *addr)
458{
459 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
460}
461
462static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
463{
464 struct nlattr *nla;
465
466 nla = (struct nlattr *) ((char *) mx + len);
467 nla->nla_type = type;
468 nla->nla_len = nla_attr_size(4);
469 *(u32 *) nla_data(nla) = value;
470
471 return len + nla_total_size(4);
472}
473
474static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
475 struct fib_config *cfg)
476{
477 __be32 addr;
478 int plen;
479
480 memset(cfg, 0, sizeof(*cfg));
481 cfg->fc_nlinfo.nl_net = net;
482
483 if (rt->rt_dst.sa_family != AF_INET)
484 return -EAFNOSUPPORT;
485
486 /*
487 * Check mask for validity:
488 * a) it must be contiguous.
489 * b) destination must have all host bits clear.
490 * c) if application forgot to set correct family (AF_INET),
491 * reject request unless it is absolutely clear i.e.
492 * both family and mask are zero.
493 */
494 plen = 32;
495 addr = sk_extract_addr(&rt->rt_dst);
496 if (!(rt->rt_flags & RTF_HOST)) {
497 __be32 mask = sk_extract_addr(&rt->rt_genmask);
498
499 if (rt->rt_genmask.sa_family != AF_INET) {
500 if (mask || rt->rt_genmask.sa_family)
501 return -EAFNOSUPPORT;
502 }
503
504 if (bad_mask(mask, addr))
505 return -EINVAL;
506
507 plen = inet_mask_len(mask);
508 }
509
510 cfg->fc_dst_len = plen;
511 cfg->fc_dst = addr;
512
513 if (cmd != SIOCDELRT) {
514 cfg->fc_nlflags = NLM_F_CREATE;
515 cfg->fc_protocol = RTPROT_BOOT;
516 }
517
518 if (rt->rt_metric)
519 cfg->fc_priority = rt->rt_metric - 1;
520
521 if (rt->rt_flags & RTF_REJECT) {
522 cfg->fc_scope = RT_SCOPE_HOST;
523 cfg->fc_type = RTN_UNREACHABLE;
524 return 0;
525 }
526
527 cfg->fc_scope = RT_SCOPE_NOWHERE;
528 cfg->fc_type = RTN_UNICAST;
529
530 if (rt->rt_dev) {
531 char *colon;
532 struct net_device *dev;
533 char devname[IFNAMSIZ];
534
535 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
536 return -EFAULT;
537
538 devname[IFNAMSIZ-1] = 0;
539 colon = strchr(devname, ':');
540 if (colon)
541 *colon = 0;
542 dev = __dev_get_by_name(net, devname);
543 if (!dev)
544 return -ENODEV;
545 cfg->fc_oif = dev->ifindex;
546 cfg->fc_table = l3mdev_fib_table(dev);
547 if (colon) {
548 const struct in_ifaddr *ifa;
549 struct in_device *in_dev;
550
551 in_dev = __in_dev_get_rtnl(dev);
552 if (!in_dev)
553 return -ENODEV;
554
555 *colon = ':';
556
557 rcu_read_lock();
558 in_dev_for_each_ifa_rcu(ifa, in_dev) {
559 if (strcmp(ifa->ifa_label, devname) == 0)
560 break;
561 }
562 rcu_read_unlock();
563
564 if (!ifa)
565 return -ENODEV;
566 cfg->fc_prefsrc = ifa->ifa_local;
567 }
568 }
569
570 addr = sk_extract_addr(&rt->rt_gateway);
571 if (rt->rt_gateway.sa_family == AF_INET && addr) {
572 unsigned int addr_type;
573
574 cfg->fc_gw4 = addr;
575 cfg->fc_gw_family = AF_INET;
576 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
577 if (rt->rt_flags & RTF_GATEWAY &&
578 addr_type == RTN_UNICAST)
579 cfg->fc_scope = RT_SCOPE_UNIVERSE;
580 }
581
582 if (cmd == SIOCDELRT)
583 return 0;
584
585 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family)
586 return -EINVAL;
587
588 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
589 cfg->fc_scope = RT_SCOPE_LINK;
590
591 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
592 struct nlattr *mx;
593 int len = 0;
594
595 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL);
596 if (!mx)
597 return -ENOMEM;
598
599 if (rt->rt_flags & RTF_MTU)
600 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
601
602 if (rt->rt_flags & RTF_WINDOW)
603 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
604
605 if (rt->rt_flags & RTF_IRTT)
606 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
607
608 cfg->fc_mx = mx;
609 cfg->fc_mx_len = len;
610 }
611
612 return 0;
613}
614
615/*
616 * Handle IP routing ioctl calls.
617 * These are used to manipulate the routing tables
618 */
619int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
620{
621 struct fib_config cfg;
622 int err;
623
624 switch (cmd) {
625 case SIOCADDRT: /* Add a route */
626 case SIOCDELRT: /* Delete a route */
627 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
628 return -EPERM;
629
630 rtnl_lock();
631 err = rtentry_to_fib_config(net, cmd, rt, &cfg);
632 if (err == 0) {
633 struct fib_table *tb;
634
635 if (cmd == SIOCDELRT) {
636 tb = fib_get_table(net, cfg.fc_table);
637 if (tb)
638 err = fib_table_delete(net, tb, &cfg,
639 NULL);
640 else
641 err = -ESRCH;
642 } else {
643 tb = fib_new_table(net, cfg.fc_table);
644 if (tb)
645 err = fib_table_insert(net, tb,
646 &cfg, NULL);
647 else
648 err = -ENOBUFS;
649 }
650
651 /* allocated by rtentry_to_fib_config() */
652 kfree(cfg.fc_mx);
653 }
654 rtnl_unlock();
655 return err;
656 }
657 return -EINVAL;
658}
659
660const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
661 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 },
662 [RTA_DST] = { .type = NLA_U32 },
663 [RTA_SRC] = { .type = NLA_U32 },
664 [RTA_IIF] = { .type = NLA_U32 },
665 [RTA_OIF] = { .type = NLA_U32 },
666 [RTA_GATEWAY] = { .type = NLA_U32 },
667 [RTA_PRIORITY] = { .type = NLA_U32 },
668 [RTA_PREFSRC] = { .type = NLA_U32 },
669 [RTA_METRICS] = { .type = NLA_NESTED },
670 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
671 [RTA_FLOW] = { .type = NLA_U32 },
672 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
673 [RTA_ENCAP] = { .type = NLA_NESTED },
674 [RTA_UID] = { .type = NLA_U32 },
675 [RTA_MARK] = { .type = NLA_U32 },
676 [RTA_TABLE] = { .type = NLA_U32 },
677 [RTA_IP_PROTO] = { .type = NLA_U8 },
678 [RTA_SPORT] = { .type = NLA_U16 },
679 [RTA_DPORT] = { .type = NLA_U16 },
680 [RTA_NH_ID] = { .type = NLA_U32 },
681};
682
683int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
684 struct netlink_ext_ack *extack)
685{
686 struct rtvia *via;
687 int alen;
688
689 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
690 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA");
691 return -EINVAL;
692 }
693
694 via = nla_data(nla);
695 alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr);
696
697 switch (via->rtvia_family) {
698 case AF_INET:
699 if (alen != sizeof(__be32)) {
700 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA");
701 return -EINVAL;
702 }
703 cfg->fc_gw_family = AF_INET;
704 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr);
705 break;
706 case AF_INET6:
707#ifdef CONFIG_IPV6
708 if (alen != sizeof(struct in6_addr)) {
709 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA");
710 return -EINVAL;
711 }
712 cfg->fc_gw_family = AF_INET6;
713 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr);
714#else
715 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
716 return -EINVAL;
717#endif
718 break;
719 default:
720 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA");
721 return -EINVAL;
722 }
723
724 return 0;
725}
726
727static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
728 struct nlmsghdr *nlh, struct fib_config *cfg,
729 struct netlink_ext_ack *extack)
730{
731 bool has_gw = false, has_via = false;
732 struct nlattr *attr;
733 int err, remaining;
734 struct rtmsg *rtm;
735
736 err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
737 rtm_ipv4_policy, extack);
738 if (err < 0)
739 goto errout;
740
741 memset(cfg, 0, sizeof(*cfg));
742
743 rtm = nlmsg_data(nlh);
744 cfg->fc_dst_len = rtm->rtm_dst_len;
745 cfg->fc_tos = rtm->rtm_tos;
746 cfg->fc_table = rtm->rtm_table;
747 cfg->fc_protocol = rtm->rtm_protocol;
748 cfg->fc_scope = rtm->rtm_scope;
749 cfg->fc_type = rtm->rtm_type;
750 cfg->fc_flags = rtm->rtm_flags;
751 cfg->fc_nlflags = nlh->nlmsg_flags;
752
753 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
754 cfg->fc_nlinfo.nlh = nlh;
755 cfg->fc_nlinfo.nl_net = net;
756
757 if (cfg->fc_type > RTN_MAX) {
758 NL_SET_ERR_MSG(extack, "Invalid route type");
759 err = -EINVAL;
760 goto errout;
761 }
762
763 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
764 switch (nla_type(attr)) {
765 case RTA_DST:
766 cfg->fc_dst = nla_get_be32(attr);
767 break;
768 case RTA_OIF:
769 cfg->fc_oif = nla_get_u32(attr);
770 break;
771 case RTA_GATEWAY:
772 has_gw = true;
773 cfg->fc_gw4 = nla_get_be32(attr);
774 if (cfg->fc_gw4)
775 cfg->fc_gw_family = AF_INET;
776 break;
777 case RTA_VIA:
778 has_via = true;
779 err = fib_gw_from_via(cfg, attr, extack);
780 if (err)
781 goto errout;
782 break;
783 case RTA_PRIORITY:
784 cfg->fc_priority = nla_get_u32(attr);
785 break;
786 case RTA_PREFSRC:
787 cfg->fc_prefsrc = nla_get_be32(attr);
788 break;
789 case RTA_METRICS:
790 cfg->fc_mx = nla_data(attr);
791 cfg->fc_mx_len = nla_len(attr);
792 break;
793 case RTA_MULTIPATH:
794 err = lwtunnel_valid_encap_type_attr(nla_data(attr),
795 nla_len(attr),
796 extack);
797 if (err < 0)
798 goto errout;
799 cfg->fc_mp = nla_data(attr);
800 cfg->fc_mp_len = nla_len(attr);
801 break;
802 case RTA_FLOW:
803 cfg->fc_flow = nla_get_u32(attr);
804 break;
805 case RTA_TABLE:
806 cfg->fc_table = nla_get_u32(attr);
807 break;
808 case RTA_ENCAP:
809 cfg->fc_encap = attr;
810 break;
811 case RTA_ENCAP_TYPE:
812 cfg->fc_encap_type = nla_get_u16(attr);
813 err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
814 extack);
815 if (err < 0)
816 goto errout;
817 break;
818 case RTA_NH_ID:
819 cfg->fc_nh_id = nla_get_u32(attr);
820 break;
821 }
822 }
823
824 if (cfg->fc_nh_id) {
825 if (cfg->fc_oif || cfg->fc_gw_family ||
826 cfg->fc_encap || cfg->fc_mp) {
827 NL_SET_ERR_MSG(extack,
828 "Nexthop specification and nexthop id are mutually exclusive");
829 return -EINVAL;
830 }
831 }
832
833 if (has_gw && has_via) {
834 NL_SET_ERR_MSG(extack,
835 "Nexthop configuration can not contain both GATEWAY and VIA");
836 goto errout;
837 }
838
839 return 0;
840errout:
841 return err;
842}
843
844static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
845 struct netlink_ext_ack *extack)
846{
847 struct net *net = sock_net(skb->sk);
848 struct fib_config cfg;
849 struct fib_table *tb;
850 int err;
851
852 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
853 if (err < 0)
854 goto errout;
855
856 if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) {
857 NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
858 err = -EINVAL;
859 goto errout;
860 }
861
862 tb = fib_get_table(net, cfg.fc_table);
863 if (!tb) {
864 NL_SET_ERR_MSG(extack, "FIB table does not exist");
865 err = -ESRCH;
866 goto errout;
867 }
868
869 err = fib_table_delete(net, tb, &cfg, extack);
870errout:
871 return err;
872}
873
874static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
875 struct netlink_ext_ack *extack)
876{
877 struct net *net = sock_net(skb->sk);
878 struct fib_config cfg;
879 struct fib_table *tb;
880 int err;
881
882 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
883 if (err < 0)
884 goto errout;
885
886 tb = fib_new_table(net, cfg.fc_table);
887 if (!tb) {
888 err = -ENOBUFS;
889 goto errout;
890 }
891
892 err = fib_table_insert(net, tb, &cfg, extack);
893 if (!err && cfg.fc_type == RTN_LOCAL)
894 net->ipv4.fib_has_custom_local_routes = true;
895errout:
896 return err;
897}
898
899int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
900 struct fib_dump_filter *filter,
901 struct netlink_callback *cb)
902{
903 struct netlink_ext_ack *extack = cb->extack;
904 struct nlattr *tb[RTA_MAX + 1];
905 struct rtmsg *rtm;
906 int err, i;
907
908 ASSERT_RTNL();
909
910 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
911 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request");
912 return -EINVAL;
913 }
914
915 rtm = nlmsg_data(nlh);
916 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos ||
917 rtm->rtm_scope) {
918 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request");
919 return -EINVAL;
920 }
921
922 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) {
923 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request");
924 return -EINVAL;
925 }
926 if (rtm->rtm_flags & RTM_F_CLONED)
927 filter->dump_routes = false;
928 else
929 filter->dump_exceptions = false;
930
931 filter->dump_all_families = (rtm->rtm_family == AF_UNSPEC);
932 filter->flags = rtm->rtm_flags;
933 filter->protocol = rtm->rtm_protocol;
934 filter->rt_type = rtm->rtm_type;
935 filter->table_id = rtm->rtm_table;
936
937 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
938 rtm_ipv4_policy, extack);
939 if (err < 0)
940 return err;
941
942 for (i = 0; i <= RTA_MAX; ++i) {
943 int ifindex;
944
945 if (!tb[i])
946 continue;
947
948 switch (i) {
949 case RTA_TABLE:
950 filter->table_id = nla_get_u32(tb[i]);
951 break;
952 case RTA_OIF:
953 ifindex = nla_get_u32(tb[i]);
954 filter->dev = __dev_get_by_index(net, ifindex);
955 if (!filter->dev)
956 return -ENODEV;
957 break;
958 default:
959 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
960 return -EINVAL;
961 }
962 }
963
964 if (filter->flags || filter->protocol || filter->rt_type ||
965 filter->table_id || filter->dev) {
966 filter->filter_set = 1;
967 cb->answer_flags = NLM_F_DUMP_FILTERED;
968 }
969
970 return 0;
971}
972EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req);
973
974static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
975{
976 struct fib_dump_filter filter = { .dump_routes = true,
977 .dump_exceptions = true };
978 const struct nlmsghdr *nlh = cb->nlh;
979 struct net *net = sock_net(skb->sk);
980 unsigned int h, s_h;
981 unsigned int e = 0, s_e;
982 struct fib_table *tb;
983 struct hlist_head *head;
984 int dumped = 0, err;
985
986 if (cb->strict_check) {
987 err = ip_valid_fib_dump_req(net, nlh, &filter, cb);
988 if (err < 0)
989 return err;
990 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
991 struct rtmsg *rtm = nlmsg_data(nlh);
992
993 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED);
994 }
995
996 /* ipv4 does not use prefix flag */
997 if (filter.flags & RTM_F_PREFIX)
998 return skb->len;
999
1000 if (filter.table_id) {
1001 tb = fib_get_table(net, filter.table_id);
1002 if (!tb) {
1003 if (filter.dump_all_families)
1004 return skb->len;
1005
1006 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist");
1007 return -ENOENT;
1008 }
1009
1010 err = fib_table_dump(tb, skb, cb, &filter);
1011 return skb->len ? : err;
1012 }
1013
1014 s_h = cb->args[0];
1015 s_e = cb->args[1];
1016
1017 rcu_read_lock();
1018
1019 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
1020 e = 0;
1021 head = &net->ipv4.fib_table_hash[h];
1022 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
1023 if (e < s_e)
1024 goto next;
1025 if (dumped)
1026 memset(&cb->args[2], 0, sizeof(cb->args) -
1027 2 * sizeof(cb->args[0]));
1028 err = fib_table_dump(tb, skb, cb, &filter);
1029 if (err < 0) {
1030 if (likely(skb->len))
1031 goto out;
1032
1033 goto out_err;
1034 }
1035 dumped = 1;
1036next:
1037 e++;
1038 }
1039 }
1040out:
1041 err = skb->len;
1042out_err:
1043 rcu_read_unlock();
1044
1045 cb->args[1] = e;
1046 cb->args[0] = h;
1047
1048 return err;
1049}
1050
1051/* Prepare and feed intra-kernel routing request.
1052 * Really, it should be netlink message, but :-( netlink
1053 * can be not configured, so that we feed it directly
1054 * to fib engine. It is legal, because all events occur
1055 * only when netlink is already locked.
1056 */
1057static void fib_magic(int cmd, int type, __be32 dst, int dst_len,
1058 struct in_ifaddr *ifa, u32 rt_priority)
1059{
1060 struct net *net = dev_net(ifa->ifa_dev->dev);
1061 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
1062 struct fib_table *tb;
1063 struct fib_config cfg = {
1064 .fc_protocol = RTPROT_KERNEL,
1065 .fc_type = type,
1066 .fc_dst = dst,
1067 .fc_dst_len = dst_len,
1068 .fc_priority = rt_priority,
1069 .fc_prefsrc = ifa->ifa_local,
1070 .fc_oif = ifa->ifa_dev->dev->ifindex,
1071 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
1072 .fc_nlinfo = {
1073 .nl_net = net,
1074 },
1075 };
1076
1077 if (!tb_id)
1078 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
1079
1080 tb = fib_new_table(net, tb_id);
1081 if (!tb)
1082 return;
1083
1084 cfg.fc_table = tb->tb_id;
1085
1086 if (type != RTN_LOCAL)
1087 cfg.fc_scope = RT_SCOPE_LINK;
1088 else
1089 cfg.fc_scope = RT_SCOPE_HOST;
1090
1091 if (cmd == RTM_NEWROUTE)
1092 fib_table_insert(net, tb, &cfg, NULL);
1093 else
1094 fib_table_delete(net, tb, &cfg, NULL);
1095}
1096
1097void fib_add_ifaddr(struct in_ifaddr *ifa)
1098{
1099 struct in_device *in_dev = ifa->ifa_dev;
1100 struct net_device *dev = in_dev->dev;
1101 struct in_ifaddr *prim = ifa;
1102 __be32 mask = ifa->ifa_mask;
1103 __be32 addr = ifa->ifa_local;
1104 __be32 prefix = ifa->ifa_address & mask;
1105
1106 if (ifa->ifa_flags & IFA_F_SECONDARY) {
1107 prim = inet_ifa_byprefix(in_dev, prefix, mask);
1108 if (!prim) {
1109 pr_warn("%s: bug: prim == NULL\n", __func__);
1110 return;
1111 }
1112 }
1113
1114 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0);
1115
1116 if (!(dev->flags & IFF_UP))
1117 return;
1118
1119 /* Add broadcast address, if it is explicitly assigned. */
1120 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
1121 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1122 prim, 0);
1123
1124 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
1125 (prefix != addr || ifa->ifa_prefixlen < 32)) {
1126 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1127 fib_magic(RTM_NEWROUTE,
1128 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1129 prefix, ifa->ifa_prefixlen, prim,
1130 ifa->ifa_rt_priority);
1131
1132 /* Add network specific broadcasts, when it takes a sense */
1133 if (ifa->ifa_prefixlen < 31) {
1134 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32,
1135 prim, 0);
1136 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
1137 32, prim, 0);
1138 }
1139 }
1140}
1141
1142void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric)
1143{
1144 __be32 prefix = ifa->ifa_address & ifa->ifa_mask;
1145 struct in_device *in_dev = ifa->ifa_dev;
1146 struct net_device *dev = in_dev->dev;
1147
1148 if (!(dev->flags & IFF_UP) ||
1149 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) ||
1150 ipv4_is_zeronet(prefix) ||
1151 (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32))
1152 return;
1153
1154 /* add the new */
1155 fib_magic(RTM_NEWROUTE,
1156 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1157 prefix, ifa->ifa_prefixlen, ifa, new_metric);
1158
1159 /* delete the old */
1160 fib_magic(RTM_DELROUTE,
1161 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1162 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority);
1163}
1164
1165/* Delete primary or secondary address.
1166 * Optionally, on secondary address promotion consider the addresses
1167 * from subnet iprim as deleted, even if they are in device list.
1168 * In this case the secondary ifa can be in device list.
1169 */
1170void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
1171{
1172 struct in_device *in_dev = ifa->ifa_dev;
1173 struct net_device *dev = in_dev->dev;
1174 struct in_ifaddr *ifa1;
1175 struct in_ifaddr *prim = ifa, *prim1 = NULL;
1176 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
1177 __be32 any = ifa->ifa_address & ifa->ifa_mask;
1178#define LOCAL_OK 1
1179#define BRD_OK 2
1180#define BRD0_OK 4
1181#define BRD1_OK 8
1182 unsigned int ok = 0;
1183 int subnet = 0; /* Primary network */
1184 int gone = 1; /* Address is missing */
1185 int same_prefsrc = 0; /* Another primary with same IP */
1186
1187 if (ifa->ifa_flags & IFA_F_SECONDARY) {
1188 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
1189 if (!prim) {
1190 /* if the device has been deleted, we don't perform
1191 * address promotion
1192 */
1193 if (!in_dev->dead)
1194 pr_warn("%s: bug: prim == NULL\n", __func__);
1195 return;
1196 }
1197 if (iprim && iprim != prim) {
1198 pr_warn("%s: bug: iprim != prim\n", __func__);
1199 return;
1200 }
1201 } else if (!ipv4_is_zeronet(any) &&
1202 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
1203 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1204 fib_magic(RTM_DELROUTE,
1205 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1206 any, ifa->ifa_prefixlen, prim, 0);
1207 subnet = 1;
1208 }
1209
1210 if (in_dev->dead)
1211 goto no_promotions;
1212
1213 /* Deletion is more complicated than add.
1214 * We should take care of not to delete too much :-)
1215 *
1216 * Scan address list to be sure that addresses are really gone.
1217 */
1218 rcu_read_lock();
1219 in_dev_for_each_ifa_rcu(ifa1, in_dev) {
1220 if (ifa1 == ifa) {
1221 /* promotion, keep the IP */
1222 gone = 0;
1223 continue;
1224 }
1225 /* Ignore IFAs from our subnet */
1226 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
1227 inet_ifa_match(ifa1->ifa_address, iprim))
1228 continue;
1229
1230 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
1231 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
1232 /* Another address from our subnet? */
1233 if (ifa1->ifa_mask == prim->ifa_mask &&
1234 inet_ifa_match(ifa1->ifa_address, prim))
1235 prim1 = prim;
1236 else {
1237 /* We reached the secondaries, so
1238 * same_prefsrc should be determined.
1239 */
1240 if (!same_prefsrc)
1241 continue;
1242 /* Search new prim1 if ifa1 is not
1243 * using the current prim1
1244 */
1245 if (!prim1 ||
1246 ifa1->ifa_mask != prim1->ifa_mask ||
1247 !inet_ifa_match(ifa1->ifa_address, prim1))
1248 prim1 = inet_ifa_byprefix(in_dev,
1249 ifa1->ifa_address,
1250 ifa1->ifa_mask);
1251 if (!prim1)
1252 continue;
1253 if (prim1->ifa_local != prim->ifa_local)
1254 continue;
1255 }
1256 } else {
1257 if (prim->ifa_local != ifa1->ifa_local)
1258 continue;
1259 prim1 = ifa1;
1260 if (prim != prim1)
1261 same_prefsrc = 1;
1262 }
1263 if (ifa->ifa_local == ifa1->ifa_local)
1264 ok |= LOCAL_OK;
1265 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1266 ok |= BRD_OK;
1267 if (brd == ifa1->ifa_broadcast)
1268 ok |= BRD1_OK;
1269 if (any == ifa1->ifa_broadcast)
1270 ok |= BRD0_OK;
1271 /* primary has network specific broadcasts */
1272 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1273 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1274 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1275
1276 if (!ipv4_is_zeronet(any1)) {
1277 if (ifa->ifa_broadcast == brd1 ||
1278 ifa->ifa_broadcast == any1)
1279 ok |= BRD_OK;
1280 if (brd == brd1 || brd == any1)
1281 ok |= BRD1_OK;
1282 if (any == brd1 || any == any1)
1283 ok |= BRD0_OK;
1284 }
1285 }
1286 }
1287 rcu_read_unlock();
1288
1289no_promotions:
1290 if (!(ok & BRD_OK))
1291 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1292 prim, 0);
1293 if (subnet && ifa->ifa_prefixlen < 31) {
1294 if (!(ok & BRD1_OK))
1295 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32,
1296 prim, 0);
1297 if (!(ok & BRD0_OK))
1298 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32,
1299 prim, 0);
1300 }
1301 if (!(ok & LOCAL_OK)) {
1302 unsigned int addr_type;
1303
1304 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0);
1305
1306 /* Check, that this local address finally disappeared. */
1307 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1308 ifa->ifa_local);
1309 if (gone && addr_type != RTN_LOCAL) {
1310 /* And the last, but not the least thing.
1311 * We must flush stray FIB entries.
1312 *
1313 * First of all, we scan fib_info list searching
1314 * for stray nexthop entries, then ignite fib_flush.
1315 */
1316 if (fib_sync_down_addr(dev, ifa->ifa_local))
1317 fib_flush(dev_net(dev));
1318 }
1319 }
1320#undef LOCAL_OK
1321#undef BRD_OK
1322#undef BRD0_OK
1323#undef BRD1_OK
1324}
1325
1326static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1327{
1328
1329 struct fib_result res;
1330 struct flowi4 fl4 = {
1331 .flowi4_mark = frn->fl_mark,
1332 .daddr = frn->fl_addr,
1333 .flowi4_tos = frn->fl_tos,
1334 .flowi4_scope = frn->fl_scope,
1335 };
1336 struct fib_table *tb;
1337
1338 rcu_read_lock();
1339
1340 tb = fib_get_table(net, frn->tb_id_in);
1341
1342 frn->err = -ENOENT;
1343 if (tb) {
1344 local_bh_disable();
1345
1346 frn->tb_id = tb->tb_id;
1347 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1348
1349 if (!frn->err) {
1350 frn->prefixlen = res.prefixlen;
1351 frn->nh_sel = res.nh_sel;
1352 frn->type = res.type;
1353 frn->scope = res.scope;
1354 }
1355 local_bh_enable();
1356 }
1357
1358 rcu_read_unlock();
1359}
1360
1361static void nl_fib_input(struct sk_buff *skb)
1362{
1363 struct net *net;
1364 struct fib_result_nl *frn;
1365 struct nlmsghdr *nlh;
1366 u32 portid;
1367
1368 net = sock_net(skb->sk);
1369 nlh = nlmsg_hdr(skb);
1370 if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1371 skb->len < nlh->nlmsg_len ||
1372 nlmsg_len(nlh) < sizeof(*frn))
1373 return;
1374
1375 skb = netlink_skb_clone(skb, GFP_KERNEL);
1376 if (!skb)
1377 return;
1378 nlh = nlmsg_hdr(skb);
1379
1380 frn = (struct fib_result_nl *) nlmsg_data(nlh);
1381 nl_fib_lookup(net, frn);
1382
1383 portid = NETLINK_CB(skb).portid; /* netlink portid */
1384 NETLINK_CB(skb).portid = 0; /* from kernel */
1385 NETLINK_CB(skb).dst_group = 0; /* unicast */
1386 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1387}
1388
1389static int __net_init nl_fib_lookup_init(struct net *net)
1390{
1391 struct sock *sk;
1392 struct netlink_kernel_cfg cfg = {
1393 .input = nl_fib_input,
1394 };
1395
1396 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1397 if (!sk)
1398 return -EAFNOSUPPORT;
1399 net->ipv4.fibnl = sk;
1400 return 0;
1401}
1402
1403static void nl_fib_lookup_exit(struct net *net)
1404{
1405 netlink_kernel_release(net->ipv4.fibnl);
1406 net->ipv4.fibnl = NULL;
1407}
1408
1409static void fib_disable_ip(struct net_device *dev, unsigned long event,
1410 bool force)
1411{
1412 if (fib_sync_down_dev(dev, event, force))
1413 fib_flush(dev_net(dev));
1414 else
1415 rt_cache_flush(dev_net(dev));
1416 arp_ifdown(dev);
1417}
1418
1419static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1420{
1421 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1422 struct net_device *dev = ifa->ifa_dev->dev;
1423 struct net *net = dev_net(dev);
1424
1425 switch (event) {
1426 case NETDEV_UP:
1427 fib_add_ifaddr(ifa);
1428#ifdef CONFIG_IP_ROUTE_MULTIPATH
1429 fib_sync_up(dev, RTNH_F_DEAD);
1430#endif
1431 atomic_inc(&net->ipv4.dev_addr_genid);
1432 rt_cache_flush(dev_net(dev));
1433 break;
1434 case NETDEV_DOWN:
1435 fib_del_ifaddr(ifa, NULL);
1436 atomic_inc(&net->ipv4.dev_addr_genid);
1437 if (!ifa->ifa_dev->ifa_list) {
1438 /* Last address was deleted from this interface.
1439 * Disable IP.
1440 */
1441 fib_disable_ip(dev, event, true);
1442 } else {
1443 rt_cache_flush(dev_net(dev));
1444 }
1445 break;
1446 }
1447 return NOTIFY_DONE;
1448}
1449
1450static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1451{
1452 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1453 struct netdev_notifier_changeupper_info *upper_info = ptr;
1454 struct netdev_notifier_info_ext *info_ext = ptr;
1455 struct in_device *in_dev;
1456 struct net *net = dev_net(dev);
1457 struct in_ifaddr *ifa;
1458 unsigned int flags;
1459
1460 if (event == NETDEV_UNREGISTER) {
1461 fib_disable_ip(dev, event, true);
1462 rt_flush_dev(dev);
1463 return NOTIFY_DONE;
1464 }
1465
1466 in_dev = __in_dev_get_rtnl(dev);
1467 if (!in_dev)
1468 return NOTIFY_DONE;
1469
1470 switch (event) {
1471 case NETDEV_UP:
1472 in_dev_for_each_ifa_rtnl(ifa, in_dev) {
1473 fib_add_ifaddr(ifa);
1474 }
1475#ifdef CONFIG_IP_ROUTE_MULTIPATH
1476 fib_sync_up(dev, RTNH_F_DEAD);
1477#endif
1478 atomic_inc(&net->ipv4.dev_addr_genid);
1479 rt_cache_flush(net);
1480 break;
1481 case NETDEV_DOWN:
1482 fib_disable_ip(dev, event, false);
1483 break;
1484 case NETDEV_CHANGE:
1485 flags = dev_get_flags(dev);
1486 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1487 fib_sync_up(dev, RTNH_F_LINKDOWN);
1488 else
1489 fib_sync_down_dev(dev, event, false);
1490 rt_cache_flush(net);
1491 break;
1492 case NETDEV_CHANGEMTU:
1493 fib_sync_mtu(dev, info_ext->ext.mtu);
1494 rt_cache_flush(net);
1495 break;
1496 case NETDEV_CHANGEUPPER:
1497 upper_info = ptr;
1498 /* flush all routes if dev is linked to or unlinked from
1499 * an L3 master device (e.g., VRF)
1500 */
1501 if (upper_info->upper_dev &&
1502 netif_is_l3_master(upper_info->upper_dev))
1503 fib_disable_ip(dev, NETDEV_DOWN, true);
1504 break;
1505 }
1506 return NOTIFY_DONE;
1507}
1508
1509static struct notifier_block fib_inetaddr_notifier = {
1510 .notifier_call = fib_inetaddr_event,
1511};
1512
1513static struct notifier_block fib_netdev_notifier = {
1514 .notifier_call = fib_netdev_event,
1515};
1516
1517static int __net_init ip_fib_net_init(struct net *net)
1518{
1519 int err;
1520 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1521
1522 err = fib4_notifier_init(net);
1523 if (err)
1524 return err;
1525
1526 /* Avoid false sharing : Use at least a full cache line */
1527 size = max_t(size_t, size, L1_CACHE_BYTES);
1528
1529 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1530 if (!net->ipv4.fib_table_hash) {
1531 err = -ENOMEM;
1532 goto err_table_hash_alloc;
1533 }
1534
1535 err = fib4_rules_init(net);
1536 if (err < 0)
1537 goto err_rules_init;
1538 return 0;
1539
1540err_rules_init:
1541 kfree(net->ipv4.fib_table_hash);
1542err_table_hash_alloc:
1543 fib4_notifier_exit(net);
1544 return err;
1545}
1546
1547static void ip_fib_net_exit(struct net *net)
1548{
1549 int i;
1550
1551 rtnl_lock();
1552#ifdef CONFIG_IP_MULTIPLE_TABLES
1553 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1554 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1555#endif
1556 /* Destroy the tables in reverse order to guarantee that the
1557 * local table, ID 255, is destroyed before the main table, ID
1558 * 254. This is necessary as the local table may contain
1559 * references to data contained in the main table.
1560 */
1561 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1562 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1563 struct hlist_node *tmp;
1564 struct fib_table *tb;
1565
1566 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1567 hlist_del(&tb->tb_hlist);
1568 fib_table_flush(net, tb, true);
1569 fib_free_table(tb);
1570 }
1571 }
1572
1573#ifdef CONFIG_IP_MULTIPLE_TABLES
1574 fib4_rules_exit(net);
1575#endif
1576 rtnl_unlock();
1577 kfree(net->ipv4.fib_table_hash);
1578 fib4_notifier_exit(net);
1579}
1580
1581static int __net_init fib_net_init(struct net *net)
1582{
1583 int error;
1584
1585#ifdef CONFIG_IP_ROUTE_CLASSID
1586 net->ipv4.fib_num_tclassid_users = 0;
1587#endif
1588 error = ip_fib_net_init(net);
1589 if (error < 0)
1590 goto out;
1591 error = nl_fib_lookup_init(net);
1592 if (error < 0)
1593 goto out_nlfl;
1594 error = fib_proc_init(net);
1595 if (error < 0)
1596 goto out_proc;
1597out:
1598 return error;
1599
1600out_proc:
1601 nl_fib_lookup_exit(net);
1602out_nlfl:
1603 ip_fib_net_exit(net);
1604 goto out;
1605}
1606
1607static void __net_exit fib_net_exit(struct net *net)
1608{
1609 fib_proc_exit(net);
1610 nl_fib_lookup_exit(net);
1611 ip_fib_net_exit(net);
1612}
1613
1614static struct pernet_operations fib_net_ops = {
1615 .init = fib_net_init,
1616 .exit = fib_net_exit,
1617};
1618
1619void __init ip_fib_init(void)
1620{
1621 fib_trie_init();
1622
1623 register_pernet_subsys(&fib_net_ops);
1624
1625 register_netdevice_notifier(&fib_netdev_notifier);
1626 register_inetaddr_notifier(&fib_inetaddr_notifier);
1627
1628 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0);
1629 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0);
1630 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0);
1631}