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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/inet_dscp.h>
36#include <net/ip.h>
37#include <net/protocol.h>
38#include <net/route.h>
39#include <net/tcp.h>
40#include <net/sock.h>
41#include <net/arp.h>
42#include <net/ip_fib.h>
43#include <net/nexthop.h>
44#include <net/rtnetlink.h>
45#include <net/xfrm.h>
46#include <net/l3mdev.h>
47#include <net/lwtunnel.h>
48#include <trace/events/fib.h>
49
50#ifndef CONFIG_IP_MULTIPLE_TABLES
51
52static int __net_init fib4_rules_init(struct net *net)
53{
54 struct fib_table *local_table, *main_table;
55
56 main_table = fib_trie_table(RT_TABLE_MAIN, NULL);
57 if (!main_table)
58 return -ENOMEM;
59
60 local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
61 if (!local_table)
62 goto fail;
63
64 hlist_add_head_rcu(&local_table->tb_hlist,
65 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
66 hlist_add_head_rcu(&main_table->tb_hlist,
67 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
68 return 0;
69
70fail:
71 fib_free_table(main_table);
72 return -ENOMEM;
73}
74#else
75
76struct fib_table *fib_new_table(struct net *net, u32 id)
77{
78 struct fib_table *tb, *alias = NULL;
79 unsigned int h;
80
81 if (id == 0)
82 id = RT_TABLE_MAIN;
83 tb = fib_get_table(net, id);
84 if (tb)
85 return tb;
86
87 if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules)
88 alias = fib_new_table(net, RT_TABLE_MAIN);
89
90 tb = fib_trie_table(id, alias);
91 if (!tb)
92 return NULL;
93
94 switch (id) {
95 case RT_TABLE_MAIN:
96 rcu_assign_pointer(net->ipv4.fib_main, tb);
97 break;
98 case RT_TABLE_DEFAULT:
99 rcu_assign_pointer(net->ipv4.fib_default, tb);
100 break;
101 default:
102 break;
103 }
104
105 h = id & (FIB_TABLE_HASHSZ - 1);
106 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
107 return tb;
108}
109EXPORT_SYMBOL_GPL(fib_new_table);
110
111/* caller must hold either rtnl or rcu read lock */
112struct fib_table *fib_get_table(struct net *net, u32 id)
113{
114 struct fib_table *tb;
115 struct hlist_head *head;
116 unsigned int h;
117
118 if (id == 0)
119 id = RT_TABLE_MAIN;
120 h = id & (FIB_TABLE_HASHSZ - 1);
121
122 head = &net->ipv4.fib_table_hash[h];
123 hlist_for_each_entry_rcu(tb, head, tb_hlist,
124 lockdep_rtnl_is_held()) {
125 if (tb->tb_id == id)
126 return tb;
127 }
128 return NULL;
129}
130#endif /* CONFIG_IP_MULTIPLE_TABLES */
131
132static void fib_replace_table(struct net *net, struct fib_table *old,
133 struct fib_table *new)
134{
135#ifdef CONFIG_IP_MULTIPLE_TABLES
136 switch (new->tb_id) {
137 case RT_TABLE_MAIN:
138 rcu_assign_pointer(net->ipv4.fib_main, new);
139 break;
140 case RT_TABLE_DEFAULT:
141 rcu_assign_pointer(net->ipv4.fib_default, new);
142 break;
143 default:
144 break;
145 }
146
147#endif
148 /* replace the old table in the hlist */
149 hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
150}
151
152int fib_unmerge(struct net *net)
153{
154 struct fib_table *old, *new, *main_table;
155
156 /* attempt to fetch local table if it has been allocated */
157 old = fib_get_table(net, RT_TABLE_LOCAL);
158 if (!old)
159 return 0;
160
161 new = fib_trie_unmerge(old);
162 if (!new)
163 return -ENOMEM;
164
165 /* table is already unmerged */
166 if (new == old)
167 return 0;
168
169 /* replace merged table with clean table */
170 fib_replace_table(net, old, new);
171 fib_free_table(old);
172
173 /* attempt to fetch main table if it has been allocated */
174 main_table = fib_get_table(net, RT_TABLE_MAIN);
175 if (!main_table)
176 return 0;
177
178 /* flush local entries from main table */
179 fib_table_flush_external(main_table);
180
181 return 0;
182}
183
184void fib_flush(struct net *net)
185{
186 int flushed = 0;
187 unsigned int h;
188
189 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
190 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
191 struct hlist_node *tmp;
192 struct fib_table *tb;
193
194 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
195 flushed += fib_table_flush(net, tb, false);
196 }
197
198 if (flushed)
199 rt_cache_flush(net);
200}
201
202/*
203 * Find address type as if only "dev" was present in the system. If
204 * on_dev is NULL then all interfaces are taken into consideration.
205 */
206static inline unsigned int __inet_dev_addr_type(struct net *net,
207 const struct net_device *dev,
208 __be32 addr, u32 tb_id)
209{
210 struct flowi4 fl4 = { .daddr = addr };
211 struct fib_result res;
212 unsigned int ret = RTN_BROADCAST;
213 struct fib_table *table;
214
215 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
216 return RTN_BROADCAST;
217 if (ipv4_is_multicast(addr))
218 return RTN_MULTICAST;
219
220 rcu_read_lock();
221
222 table = fib_get_table(net, tb_id);
223 if (table) {
224 ret = RTN_UNICAST;
225 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
226 struct fib_nh_common *nhc = fib_info_nhc(res.fi, 0);
227
228 if (!dev || dev == nhc->nhc_dev)
229 ret = res.type;
230 }
231 }
232
233 rcu_read_unlock();
234 return ret;
235}
236
237unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
238{
239 return __inet_dev_addr_type(net, NULL, addr, tb_id);
240}
241EXPORT_SYMBOL(inet_addr_type_table);
242
243unsigned int inet_addr_type(struct net *net, __be32 addr)
244{
245 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
246}
247EXPORT_SYMBOL(inet_addr_type);
248
249unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
250 __be32 addr)
251{
252 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
253
254 return __inet_dev_addr_type(net, dev, addr, rt_table);
255}
256EXPORT_SYMBOL(inet_dev_addr_type);
257
258/* inet_addr_type with dev == NULL but using the table from a dev
259 * if one is associated
260 */
261unsigned int inet_addr_type_dev_table(struct net *net,
262 const struct net_device *dev,
263 __be32 addr)
264{
265 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
266
267 return __inet_dev_addr_type(net, NULL, addr, rt_table);
268}
269EXPORT_SYMBOL(inet_addr_type_dev_table);
270
271__be32 fib_compute_spec_dst(struct sk_buff *skb)
272{
273 struct net_device *dev = skb->dev;
274 struct in_device *in_dev;
275 struct fib_result res;
276 struct rtable *rt;
277 struct net *net;
278 int scope;
279
280 rt = skb_rtable(skb);
281 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
282 RTCF_LOCAL)
283 return ip_hdr(skb)->daddr;
284
285 in_dev = __in_dev_get_rcu(dev);
286
287 net = dev_net(dev);
288
289 scope = RT_SCOPE_UNIVERSE;
290 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
291 bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev);
292 struct flowi4 fl4 = {
293 .flowi4_iif = LOOPBACK_IFINDEX,
294 .flowi4_l3mdev = l3mdev_master_ifindex_rcu(dev),
295 .daddr = ip_hdr(skb)->saddr,
296 .flowi4_tos = inet_dscp_to_dsfield(ip4h_dscp(ip_hdr(skb))),
297 .flowi4_scope = scope,
298 .flowi4_mark = vmark ? skb->mark : 0,
299 };
300 if (!fib_lookup(net, &fl4, &res, 0))
301 return fib_result_prefsrc(net, &res);
302 } else {
303 scope = RT_SCOPE_LINK;
304 }
305
306 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
307}
308
309bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev)
310{
311 bool dev_match = false;
312#ifdef CONFIG_IP_ROUTE_MULTIPATH
313 if (unlikely(fi->nh)) {
314 dev_match = nexthop_uses_dev(fi->nh, dev);
315 } else {
316 int ret;
317
318 for (ret = 0; ret < fib_info_num_path(fi); ret++) {
319 const struct fib_nh_common *nhc = fib_info_nhc(fi, ret);
320
321 if (nhc_l3mdev_matches_dev(nhc, dev)) {
322 dev_match = true;
323 break;
324 }
325 }
326 }
327#else
328 if (fib_info_nhc(fi, 0)->nhc_dev == dev)
329 dev_match = true;
330#endif
331
332 return dev_match;
333}
334EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev);
335
336/* Given (packet source, input interface) and optional (dst, oif, tos):
337 * - (main) check, that source is valid i.e. not broadcast or our local
338 * address.
339 * - figure out what "logical" interface this packet arrived
340 * and calculate "specific destination" address.
341 * - check, that packet arrived from expected physical interface.
342 * called with rcu_read_lock()
343 */
344static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
345 dscp_t dscp, int oif, struct net_device *dev,
346 int rpf, struct in_device *idev, u32 *itag)
347{
348 struct net *net = dev_net(dev);
349 enum skb_drop_reason reason;
350 struct flow_keys flkeys;
351 int ret, no_addr;
352 struct fib_result res;
353 struct flowi4 fl4;
354 bool dev_match;
355
356 fl4.flowi4_oif = 0;
357 fl4.flowi4_l3mdev = l3mdev_master_ifindex_rcu(dev);
358 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
359 fl4.daddr = src;
360 fl4.saddr = dst;
361 fl4.flowi4_tos = inet_dscp_to_dsfield(dscp);
362 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
363 fl4.flowi4_tun_key.tun_id = 0;
364 fl4.flowi4_flags = 0;
365 fl4.flowi4_uid = sock_net_uid(net, NULL);
366 fl4.flowi4_multipath_hash = 0;
367
368 no_addr = idev->ifa_list == NULL;
369
370 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
371 if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) {
372 fl4.flowi4_proto = 0;
373 fl4.fl4_sport = 0;
374 fl4.fl4_dport = 0;
375 } else {
376 swap(fl4.fl4_sport, fl4.fl4_dport);
377 }
378
379 if (fib_lookup(net, &fl4, &res, 0))
380 goto last_resort;
381 if (res.type != RTN_UNICAST) {
382 if (res.type != RTN_LOCAL) {
383 reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
384 goto e_inval;
385 } else if (!IN_DEV_ACCEPT_LOCAL(idev)) {
386 reason = SKB_DROP_REASON_IP_LOCAL_SOURCE;
387 goto e_inval;
388 }
389 }
390 fib_combine_itag(itag, &res);
391
392 dev_match = fib_info_nh_uses_dev(res.fi, dev);
393 /* This is not common, loopback packets retain skb_dst so normally they
394 * would not even hit this slow path.
395 */
396 dev_match = dev_match || (res.type == RTN_LOCAL &&
397 dev == net->loopback_dev);
398 if (dev_match) {
399 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
400 return ret;
401 }
402 if (no_addr)
403 goto last_resort;
404 if (rpf == 1)
405 goto e_rpf;
406 fl4.flowi4_oif = dev->ifindex;
407
408 ret = 0;
409 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
410 if (res.type == RTN_UNICAST)
411 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
412 }
413 return ret;
414
415last_resort:
416 if (rpf)
417 goto e_rpf;
418 *itag = 0;
419 return 0;
420
421e_inval:
422 return -reason;
423e_rpf:
424 return -SKB_DROP_REASON_IP_RPFILTER;
425}
426
427/* Ignore rp_filter for packets protected by IPsec. */
428int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
429 dscp_t dscp, int oif, struct net_device *dev,
430 struct in_device *idev, u32 *itag)
431{
432 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
433 struct net *net = dev_net(dev);
434
435 if (!r && !fib_num_tclassid_users(net) &&
436 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
437 if (IN_DEV_ACCEPT_LOCAL(idev))
438 goto ok;
439 /* with custom local routes in place, checking local addresses
440 * only will be too optimistic, with custom rules, checking
441 * local addresses only can be too strict, e.g. due to vrf
442 */
443 if (net->ipv4.fib_has_custom_local_routes ||
444 fib4_has_custom_rules(net))
445 goto full_check;
446 /* Within the same container, it is regarded as a martian source,
447 * and the same host but different containers are not.
448 */
449 if (inet_lookup_ifaddr_rcu(net, src))
450 return -SKB_DROP_REASON_IP_LOCAL_SOURCE;
451
452ok:
453 *itag = 0;
454 return 0;
455 }
456
457full_check:
458 return __fib_validate_source(skb, src, dst, dscp, oif, dev, r, idev,
459 itag);
460}
461
462static inline __be32 sk_extract_addr(struct sockaddr *addr)
463{
464 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
465}
466
467static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
468{
469 struct nlattr *nla;
470
471 nla = (struct nlattr *) ((char *) mx + len);
472 nla->nla_type = type;
473 nla->nla_len = nla_attr_size(4);
474 *(u32 *) nla_data(nla) = value;
475
476 return len + nla_total_size(4);
477}
478
479static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
480 struct fib_config *cfg)
481{
482 __be32 addr;
483 int plen;
484
485 memset(cfg, 0, sizeof(*cfg));
486 cfg->fc_nlinfo.nl_net = net;
487
488 if (rt->rt_dst.sa_family != AF_INET)
489 return -EAFNOSUPPORT;
490
491 /*
492 * Check mask for validity:
493 * a) it must be contiguous.
494 * b) destination must have all host bits clear.
495 * c) if application forgot to set correct family (AF_INET),
496 * reject request unless it is absolutely clear i.e.
497 * both family and mask are zero.
498 */
499 plen = 32;
500 addr = sk_extract_addr(&rt->rt_dst);
501 if (!(rt->rt_flags & RTF_HOST)) {
502 __be32 mask = sk_extract_addr(&rt->rt_genmask);
503
504 if (rt->rt_genmask.sa_family != AF_INET) {
505 if (mask || rt->rt_genmask.sa_family)
506 return -EAFNOSUPPORT;
507 }
508
509 if (bad_mask(mask, addr))
510 return -EINVAL;
511
512 plen = inet_mask_len(mask);
513 }
514
515 cfg->fc_dst_len = plen;
516 cfg->fc_dst = addr;
517
518 if (cmd != SIOCDELRT) {
519 cfg->fc_nlflags = NLM_F_CREATE;
520 cfg->fc_protocol = RTPROT_BOOT;
521 }
522
523 if (rt->rt_metric)
524 cfg->fc_priority = rt->rt_metric - 1;
525
526 if (rt->rt_flags & RTF_REJECT) {
527 cfg->fc_scope = RT_SCOPE_HOST;
528 cfg->fc_type = RTN_UNREACHABLE;
529 return 0;
530 }
531
532 cfg->fc_scope = RT_SCOPE_NOWHERE;
533 cfg->fc_type = RTN_UNICAST;
534
535 if (rt->rt_dev) {
536 char *colon;
537 struct net_device *dev;
538 char devname[IFNAMSIZ];
539
540 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
541 return -EFAULT;
542
543 devname[IFNAMSIZ-1] = 0;
544 colon = strchr(devname, ':');
545 if (colon)
546 *colon = 0;
547 dev = __dev_get_by_name(net, devname);
548 if (!dev)
549 return -ENODEV;
550 cfg->fc_oif = dev->ifindex;
551 cfg->fc_table = l3mdev_fib_table(dev);
552 if (colon) {
553 const struct in_ifaddr *ifa;
554 struct in_device *in_dev;
555
556 in_dev = __in_dev_get_rtnl(dev);
557 if (!in_dev)
558 return -ENODEV;
559
560 *colon = ':';
561
562 rcu_read_lock();
563 in_dev_for_each_ifa_rcu(ifa, in_dev) {
564 if (strcmp(ifa->ifa_label, devname) == 0)
565 break;
566 }
567 rcu_read_unlock();
568
569 if (!ifa)
570 return -ENODEV;
571 cfg->fc_prefsrc = ifa->ifa_local;
572 }
573 }
574
575 addr = sk_extract_addr(&rt->rt_gateway);
576 if (rt->rt_gateway.sa_family == AF_INET && addr) {
577 unsigned int addr_type;
578
579 cfg->fc_gw4 = addr;
580 cfg->fc_gw_family = AF_INET;
581 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
582 if (rt->rt_flags & RTF_GATEWAY &&
583 addr_type == RTN_UNICAST)
584 cfg->fc_scope = RT_SCOPE_UNIVERSE;
585 }
586
587 if (!cfg->fc_table)
588 cfg->fc_table = RT_TABLE_MAIN;
589
590 if (cmd == SIOCDELRT)
591 return 0;
592
593 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family)
594 return -EINVAL;
595
596 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
597 cfg->fc_scope = RT_SCOPE_LINK;
598
599 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
600 struct nlattr *mx;
601 int len = 0;
602
603 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL);
604 if (!mx)
605 return -ENOMEM;
606
607 if (rt->rt_flags & RTF_MTU)
608 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
609
610 if (rt->rt_flags & RTF_WINDOW)
611 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
612
613 if (rt->rt_flags & RTF_IRTT)
614 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
615
616 cfg->fc_mx = mx;
617 cfg->fc_mx_len = len;
618 }
619
620 return 0;
621}
622
623/*
624 * Handle IP routing ioctl calls.
625 * These are used to manipulate the routing tables
626 */
627int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
628{
629 struct fib_config cfg;
630 int err;
631
632 switch (cmd) {
633 case SIOCADDRT: /* Add a route */
634 case SIOCDELRT: /* Delete a route */
635 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
636 return -EPERM;
637
638 rtnl_lock();
639 err = rtentry_to_fib_config(net, cmd, rt, &cfg);
640 if (err == 0) {
641 struct fib_table *tb;
642
643 if (cmd == SIOCDELRT) {
644 tb = fib_get_table(net, cfg.fc_table);
645 if (tb)
646 err = fib_table_delete(net, tb, &cfg,
647 NULL);
648 else
649 err = -ESRCH;
650 } else {
651 tb = fib_new_table(net, cfg.fc_table);
652 if (tb)
653 err = fib_table_insert(net, tb,
654 &cfg, NULL);
655 else
656 err = -ENOBUFS;
657 }
658
659 /* allocated by rtentry_to_fib_config() */
660 kfree(cfg.fc_mx);
661 }
662 rtnl_unlock();
663 return err;
664 }
665 return -EINVAL;
666}
667
668const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
669 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 },
670 [RTA_DST] = { .type = NLA_U32 },
671 [RTA_SRC] = { .type = NLA_U32 },
672 [RTA_IIF] = { .type = NLA_U32 },
673 [RTA_OIF] = { .type = NLA_U32 },
674 [RTA_GATEWAY] = { .type = NLA_U32 },
675 [RTA_PRIORITY] = { .type = NLA_U32 },
676 [RTA_PREFSRC] = { .type = NLA_U32 },
677 [RTA_METRICS] = { .type = NLA_NESTED },
678 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
679 [RTA_FLOW] = { .type = NLA_U32 },
680 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
681 [RTA_ENCAP] = { .type = NLA_NESTED },
682 [RTA_UID] = { .type = NLA_U32 },
683 [RTA_MARK] = { .type = NLA_U32 },
684 [RTA_TABLE] = { .type = NLA_U32 },
685 [RTA_IP_PROTO] = { .type = NLA_U8 },
686 [RTA_SPORT] = { .type = NLA_U16 },
687 [RTA_DPORT] = { .type = NLA_U16 },
688 [RTA_NH_ID] = { .type = NLA_U32 },
689};
690
691int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
692 struct netlink_ext_ack *extack)
693{
694 struct rtvia *via;
695 int alen;
696
697 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
698 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA");
699 return -EINVAL;
700 }
701
702 via = nla_data(nla);
703 alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr);
704
705 switch (via->rtvia_family) {
706 case AF_INET:
707 if (alen != sizeof(__be32)) {
708 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA");
709 return -EINVAL;
710 }
711 cfg->fc_gw_family = AF_INET;
712 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr);
713 break;
714 case AF_INET6:
715#if IS_ENABLED(CONFIG_IPV6)
716 if (alen != sizeof(struct in6_addr)) {
717 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA");
718 return -EINVAL;
719 }
720 cfg->fc_gw_family = AF_INET6;
721 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr);
722#else
723 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
724 return -EINVAL;
725#endif
726 break;
727 default:
728 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA");
729 return -EINVAL;
730 }
731
732 return 0;
733}
734
735static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
736 struct nlmsghdr *nlh, struct fib_config *cfg,
737 struct netlink_ext_ack *extack)
738{
739 bool has_gw = false, has_via = false;
740 struct nlattr *attr;
741 int err, remaining;
742 struct rtmsg *rtm;
743
744 err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
745 rtm_ipv4_policy, extack);
746 if (err < 0)
747 goto errout;
748
749 memset(cfg, 0, sizeof(*cfg));
750
751 rtm = nlmsg_data(nlh);
752
753 if (!inet_validate_dscp(rtm->rtm_tos)) {
754 NL_SET_ERR_MSG(extack,
755 "Invalid dsfield (tos): ECN bits must be 0");
756 err = -EINVAL;
757 goto errout;
758 }
759 cfg->fc_dscp = inet_dsfield_to_dscp(rtm->rtm_tos);
760
761 cfg->fc_dst_len = rtm->rtm_dst_len;
762 cfg->fc_table = rtm->rtm_table;
763 cfg->fc_protocol = rtm->rtm_protocol;
764 cfg->fc_scope = rtm->rtm_scope;
765 cfg->fc_type = rtm->rtm_type;
766 cfg->fc_flags = rtm->rtm_flags;
767 cfg->fc_nlflags = nlh->nlmsg_flags;
768
769 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
770 cfg->fc_nlinfo.nlh = nlh;
771 cfg->fc_nlinfo.nl_net = net;
772
773 if (cfg->fc_type > RTN_MAX) {
774 NL_SET_ERR_MSG(extack, "Invalid route type");
775 err = -EINVAL;
776 goto errout;
777 }
778
779 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
780 switch (nla_type(attr)) {
781 case RTA_DST:
782 cfg->fc_dst = nla_get_be32(attr);
783 break;
784 case RTA_OIF:
785 cfg->fc_oif = nla_get_u32(attr);
786 break;
787 case RTA_GATEWAY:
788 has_gw = true;
789 cfg->fc_gw4 = nla_get_be32(attr);
790 if (cfg->fc_gw4)
791 cfg->fc_gw_family = AF_INET;
792 break;
793 case RTA_VIA:
794 has_via = true;
795 err = fib_gw_from_via(cfg, attr, extack);
796 if (err)
797 goto errout;
798 break;
799 case RTA_PRIORITY:
800 cfg->fc_priority = nla_get_u32(attr);
801 break;
802 case RTA_PREFSRC:
803 cfg->fc_prefsrc = nla_get_be32(attr);
804 break;
805 case RTA_METRICS:
806 cfg->fc_mx = nla_data(attr);
807 cfg->fc_mx_len = nla_len(attr);
808 break;
809 case RTA_MULTIPATH:
810 err = lwtunnel_valid_encap_type_attr(nla_data(attr),
811 nla_len(attr),
812 extack);
813 if (err < 0)
814 goto errout;
815 cfg->fc_mp = nla_data(attr);
816 cfg->fc_mp_len = nla_len(attr);
817 break;
818 case RTA_FLOW:
819 cfg->fc_flow = nla_get_u32(attr);
820 break;
821 case RTA_TABLE:
822 cfg->fc_table = nla_get_u32(attr);
823 break;
824 case RTA_ENCAP:
825 cfg->fc_encap = attr;
826 break;
827 case RTA_ENCAP_TYPE:
828 cfg->fc_encap_type = nla_get_u16(attr);
829 err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
830 extack);
831 if (err < 0)
832 goto errout;
833 break;
834 case RTA_NH_ID:
835 cfg->fc_nh_id = nla_get_u32(attr);
836 break;
837 }
838 }
839
840 if (cfg->fc_nh_id) {
841 if (cfg->fc_oif || cfg->fc_gw_family ||
842 cfg->fc_encap || cfg->fc_mp) {
843 NL_SET_ERR_MSG(extack,
844 "Nexthop specification and nexthop id are mutually exclusive");
845 return -EINVAL;
846 }
847 }
848
849 if (has_gw && has_via) {
850 NL_SET_ERR_MSG(extack,
851 "Nexthop configuration can not contain both GATEWAY and VIA");
852 return -EINVAL;
853 }
854
855 if (!cfg->fc_table)
856 cfg->fc_table = RT_TABLE_MAIN;
857
858 return 0;
859errout:
860 return err;
861}
862
863static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
864 struct netlink_ext_ack *extack)
865{
866 struct net *net = sock_net(skb->sk);
867 struct fib_config cfg;
868 struct fib_table *tb;
869 int err;
870
871 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
872 if (err < 0)
873 goto errout;
874
875 if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) {
876 NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
877 err = -EINVAL;
878 goto errout;
879 }
880
881 tb = fib_get_table(net, cfg.fc_table);
882 if (!tb) {
883 NL_SET_ERR_MSG(extack, "FIB table does not exist");
884 err = -ESRCH;
885 goto errout;
886 }
887
888 err = fib_table_delete(net, tb, &cfg, extack);
889errout:
890 return err;
891}
892
893static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
894 struct netlink_ext_ack *extack)
895{
896 struct net *net = sock_net(skb->sk);
897 struct fib_config cfg;
898 struct fib_table *tb;
899 int err;
900
901 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
902 if (err < 0)
903 goto errout;
904
905 tb = fib_new_table(net, cfg.fc_table);
906 if (!tb) {
907 err = -ENOBUFS;
908 goto errout;
909 }
910
911 err = fib_table_insert(net, tb, &cfg, extack);
912 if (!err && cfg.fc_type == RTN_LOCAL)
913 net->ipv4.fib_has_custom_local_routes = true;
914errout:
915 return err;
916}
917
918int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
919 struct fib_dump_filter *filter,
920 struct netlink_callback *cb)
921{
922 struct netlink_ext_ack *extack = cb->extack;
923 struct nlattr *tb[RTA_MAX + 1];
924 struct rtmsg *rtm;
925 int err, i;
926
927 if (filter->rtnl_held)
928 ASSERT_RTNL();
929
930 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
931 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request");
932 return -EINVAL;
933 }
934
935 rtm = nlmsg_data(nlh);
936 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos ||
937 rtm->rtm_scope) {
938 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request");
939 return -EINVAL;
940 }
941
942 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) {
943 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request");
944 return -EINVAL;
945 }
946 if (rtm->rtm_flags & RTM_F_CLONED)
947 filter->dump_routes = false;
948 else
949 filter->dump_exceptions = false;
950
951 filter->flags = rtm->rtm_flags;
952 filter->protocol = rtm->rtm_protocol;
953 filter->rt_type = rtm->rtm_type;
954 filter->table_id = rtm->rtm_table;
955
956 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
957 rtm_ipv4_policy, extack);
958 if (err < 0)
959 return err;
960
961 for (i = 0; i <= RTA_MAX; ++i) {
962 int ifindex;
963
964 if (!tb[i])
965 continue;
966
967 switch (i) {
968 case RTA_TABLE:
969 filter->table_id = nla_get_u32(tb[i]);
970 break;
971 case RTA_OIF:
972 ifindex = nla_get_u32(tb[i]);
973 if (filter->rtnl_held)
974 filter->dev = __dev_get_by_index(net, ifindex);
975 else
976 filter->dev = dev_get_by_index_rcu(net, ifindex);
977 if (!filter->dev)
978 return -ENODEV;
979 break;
980 default:
981 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
982 return -EINVAL;
983 }
984 }
985
986 if (filter->flags || filter->protocol || filter->rt_type ||
987 filter->table_id || filter->dev) {
988 filter->filter_set = 1;
989 cb->answer_flags = NLM_F_DUMP_FILTERED;
990 }
991
992 return 0;
993}
994EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req);
995
996static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
997{
998 struct fib_dump_filter filter = {
999 .dump_routes = true,
1000 .dump_exceptions = true,
1001 .rtnl_held = false,
1002 };
1003 const struct nlmsghdr *nlh = cb->nlh;
1004 struct net *net = sock_net(skb->sk);
1005 unsigned int h, s_h;
1006 unsigned int e = 0, s_e;
1007 struct fib_table *tb;
1008 struct hlist_head *head;
1009 int dumped = 0, err = 0;
1010
1011 rcu_read_lock();
1012 if (cb->strict_check) {
1013 err = ip_valid_fib_dump_req(net, nlh, &filter, cb);
1014 if (err < 0)
1015 goto unlock;
1016 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
1017 struct rtmsg *rtm = nlmsg_data(nlh);
1018
1019 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED);
1020 }
1021
1022 /* ipv4 does not use prefix flag */
1023 if (filter.flags & RTM_F_PREFIX)
1024 goto unlock;
1025
1026 if (filter.table_id) {
1027 tb = fib_get_table(net, filter.table_id);
1028 if (!tb) {
1029 if (rtnl_msg_family(cb->nlh) != PF_INET)
1030 goto unlock;
1031
1032 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist");
1033 err = -ENOENT;
1034 goto unlock;
1035 }
1036 err = fib_table_dump(tb, skb, cb, &filter);
1037 goto unlock;
1038 }
1039
1040 s_h = cb->args[0];
1041 s_e = cb->args[1];
1042
1043 err = 0;
1044 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
1045 e = 0;
1046 head = &net->ipv4.fib_table_hash[h];
1047 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
1048 if (e < s_e)
1049 goto next;
1050 if (dumped)
1051 memset(&cb->args[2], 0, sizeof(cb->args) -
1052 2 * sizeof(cb->args[0]));
1053 err = fib_table_dump(tb, skb, cb, &filter);
1054 if (err < 0)
1055 goto out;
1056 dumped = 1;
1057next:
1058 e++;
1059 }
1060 }
1061out:
1062
1063 cb->args[1] = e;
1064 cb->args[0] = h;
1065
1066unlock:
1067 rcu_read_unlock();
1068 return err;
1069}
1070
1071/* Prepare and feed intra-kernel routing request.
1072 * Really, it should be netlink message, but :-( netlink
1073 * can be not configured, so that we feed it directly
1074 * to fib engine. It is legal, because all events occur
1075 * only when netlink is already locked.
1076 */
1077static void fib_magic(int cmd, int type, __be32 dst, int dst_len,
1078 struct in_ifaddr *ifa, u32 rt_priority)
1079{
1080 struct net *net = dev_net(ifa->ifa_dev->dev);
1081 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
1082 struct fib_table *tb;
1083 struct fib_config cfg = {
1084 .fc_protocol = RTPROT_KERNEL,
1085 .fc_type = type,
1086 .fc_dst = dst,
1087 .fc_dst_len = dst_len,
1088 .fc_priority = rt_priority,
1089 .fc_prefsrc = ifa->ifa_local,
1090 .fc_oif = ifa->ifa_dev->dev->ifindex,
1091 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
1092 .fc_nlinfo = {
1093 .nl_net = net,
1094 },
1095 };
1096
1097 if (!tb_id)
1098 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
1099
1100 tb = fib_new_table(net, tb_id);
1101 if (!tb)
1102 return;
1103
1104 cfg.fc_table = tb->tb_id;
1105
1106 if (type != RTN_LOCAL)
1107 cfg.fc_scope = RT_SCOPE_LINK;
1108 else
1109 cfg.fc_scope = RT_SCOPE_HOST;
1110
1111 if (cmd == RTM_NEWROUTE)
1112 fib_table_insert(net, tb, &cfg, NULL);
1113 else
1114 fib_table_delete(net, tb, &cfg, NULL);
1115}
1116
1117void fib_add_ifaddr(struct in_ifaddr *ifa)
1118{
1119 struct in_device *in_dev = ifa->ifa_dev;
1120 struct net_device *dev = in_dev->dev;
1121 struct in_ifaddr *prim = ifa;
1122 __be32 mask = ifa->ifa_mask;
1123 __be32 addr = ifa->ifa_local;
1124 __be32 prefix = ifa->ifa_address & mask;
1125
1126 if (ifa->ifa_flags & IFA_F_SECONDARY) {
1127 prim = inet_ifa_byprefix(in_dev, prefix, mask);
1128 if (!prim) {
1129 pr_warn("%s: bug: prim == NULL\n", __func__);
1130 return;
1131 }
1132 }
1133
1134 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0);
1135
1136 if (!(dev->flags & IFF_UP))
1137 return;
1138
1139 /* Add broadcast address, if it is explicitly assigned. */
1140 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) {
1141 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1142 prim, 0);
1143 arp_invalidate(dev, ifa->ifa_broadcast, false);
1144 }
1145
1146 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
1147 (prefix != addr || ifa->ifa_prefixlen < 32)) {
1148 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1149 fib_magic(RTM_NEWROUTE,
1150 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1151 prefix, ifa->ifa_prefixlen, prim,
1152 ifa->ifa_rt_priority);
1153
1154 /* Add the network broadcast address, when it makes sense */
1155 if (ifa->ifa_prefixlen < 31) {
1156 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
1157 32, prim, 0);
1158 arp_invalidate(dev, prefix | ~mask, false);
1159 }
1160 }
1161}
1162
1163void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric)
1164{
1165 __be32 prefix = ifa->ifa_address & ifa->ifa_mask;
1166 struct in_device *in_dev = ifa->ifa_dev;
1167 struct net_device *dev = in_dev->dev;
1168
1169 if (!(dev->flags & IFF_UP) ||
1170 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) ||
1171 ipv4_is_zeronet(prefix) ||
1172 (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32))
1173 return;
1174
1175 /* add the new */
1176 fib_magic(RTM_NEWROUTE,
1177 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1178 prefix, ifa->ifa_prefixlen, ifa, new_metric);
1179
1180 /* delete the old */
1181 fib_magic(RTM_DELROUTE,
1182 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1183 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority);
1184}
1185
1186/* Delete primary or secondary address.
1187 * Optionally, on secondary address promotion consider the addresses
1188 * from subnet iprim as deleted, even if they are in device list.
1189 * In this case the secondary ifa can be in device list.
1190 */
1191void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
1192{
1193 struct in_device *in_dev = ifa->ifa_dev;
1194 struct net_device *dev = in_dev->dev;
1195 struct in_ifaddr *ifa1;
1196 struct in_ifaddr *prim = ifa, *prim1 = NULL;
1197 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
1198 __be32 any = ifa->ifa_address & ifa->ifa_mask;
1199#define LOCAL_OK 1
1200#define BRD_OK 2
1201#define BRD0_OK 4
1202#define BRD1_OK 8
1203 unsigned int ok = 0;
1204 int subnet = 0; /* Primary network */
1205 int gone = 1; /* Address is missing */
1206 int same_prefsrc = 0; /* Another primary with same IP */
1207
1208 if (ifa->ifa_flags & IFA_F_SECONDARY) {
1209 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
1210 if (!prim) {
1211 /* if the device has been deleted, we don't perform
1212 * address promotion
1213 */
1214 if (!in_dev->dead)
1215 pr_warn("%s: bug: prim == NULL\n", __func__);
1216 return;
1217 }
1218 if (iprim && iprim != prim) {
1219 pr_warn("%s: bug: iprim != prim\n", __func__);
1220 return;
1221 }
1222 } else if (!ipv4_is_zeronet(any) &&
1223 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
1224 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1225 fib_magic(RTM_DELROUTE,
1226 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1227 any, ifa->ifa_prefixlen, prim, 0);
1228 subnet = 1;
1229 }
1230
1231 if (in_dev->dead)
1232 goto no_promotions;
1233
1234 /* Deletion is more complicated than add.
1235 * We should take care of not to delete too much :-)
1236 *
1237 * Scan address list to be sure that addresses are really gone.
1238 */
1239 rcu_read_lock();
1240 in_dev_for_each_ifa_rcu(ifa1, in_dev) {
1241 if (ifa1 == ifa) {
1242 /* promotion, keep the IP */
1243 gone = 0;
1244 continue;
1245 }
1246 /* Ignore IFAs from our subnet */
1247 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
1248 inet_ifa_match(ifa1->ifa_address, iprim))
1249 continue;
1250
1251 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
1252 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
1253 /* Another address from our subnet? */
1254 if (ifa1->ifa_mask == prim->ifa_mask &&
1255 inet_ifa_match(ifa1->ifa_address, prim))
1256 prim1 = prim;
1257 else {
1258 /* We reached the secondaries, so
1259 * same_prefsrc should be determined.
1260 */
1261 if (!same_prefsrc)
1262 continue;
1263 /* Search new prim1 if ifa1 is not
1264 * using the current prim1
1265 */
1266 if (!prim1 ||
1267 ifa1->ifa_mask != prim1->ifa_mask ||
1268 !inet_ifa_match(ifa1->ifa_address, prim1))
1269 prim1 = inet_ifa_byprefix(in_dev,
1270 ifa1->ifa_address,
1271 ifa1->ifa_mask);
1272 if (!prim1)
1273 continue;
1274 if (prim1->ifa_local != prim->ifa_local)
1275 continue;
1276 }
1277 } else {
1278 if (prim->ifa_local != ifa1->ifa_local)
1279 continue;
1280 prim1 = ifa1;
1281 if (prim != prim1)
1282 same_prefsrc = 1;
1283 }
1284 if (ifa->ifa_local == ifa1->ifa_local)
1285 ok |= LOCAL_OK;
1286 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1287 ok |= BRD_OK;
1288 if (brd == ifa1->ifa_broadcast)
1289 ok |= BRD1_OK;
1290 if (any == ifa1->ifa_broadcast)
1291 ok |= BRD0_OK;
1292 /* primary has network specific broadcasts */
1293 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1294 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1295 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1296
1297 if (!ipv4_is_zeronet(any1)) {
1298 if (ifa->ifa_broadcast == brd1 ||
1299 ifa->ifa_broadcast == any1)
1300 ok |= BRD_OK;
1301 if (brd == brd1 || brd == any1)
1302 ok |= BRD1_OK;
1303 if (any == brd1 || any == any1)
1304 ok |= BRD0_OK;
1305 }
1306 }
1307 }
1308 rcu_read_unlock();
1309
1310no_promotions:
1311 if (!(ok & BRD_OK))
1312 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1313 prim, 0);
1314 if (subnet && ifa->ifa_prefixlen < 31) {
1315 if (!(ok & BRD1_OK))
1316 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32,
1317 prim, 0);
1318 if (!(ok & BRD0_OK))
1319 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32,
1320 prim, 0);
1321 }
1322 if (!(ok & LOCAL_OK)) {
1323 unsigned int addr_type;
1324
1325 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0);
1326
1327 /* Check, that this local address finally disappeared. */
1328 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1329 ifa->ifa_local);
1330 if (gone && addr_type != RTN_LOCAL) {
1331 /* And the last, but not the least thing.
1332 * We must flush stray FIB entries.
1333 *
1334 * First of all, we scan fib_info list searching
1335 * for stray nexthop entries, then ignite fib_flush.
1336 */
1337 if (fib_sync_down_addr(dev, ifa->ifa_local))
1338 fib_flush(dev_net(dev));
1339 }
1340 }
1341#undef LOCAL_OK
1342#undef BRD_OK
1343#undef BRD0_OK
1344#undef BRD1_OK
1345}
1346
1347static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1348{
1349
1350 struct fib_result res;
1351 struct flowi4 fl4 = {
1352 .flowi4_mark = frn->fl_mark,
1353 .daddr = frn->fl_addr,
1354 .flowi4_tos = frn->fl_tos & INET_DSCP_MASK,
1355 .flowi4_scope = frn->fl_scope,
1356 };
1357 struct fib_table *tb;
1358
1359 rcu_read_lock();
1360
1361 tb = fib_get_table(net, frn->tb_id_in);
1362
1363 frn->err = -ENOENT;
1364 if (tb) {
1365 local_bh_disable();
1366
1367 frn->tb_id = tb->tb_id;
1368 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1369
1370 if (!frn->err) {
1371 frn->prefixlen = res.prefixlen;
1372 frn->nh_sel = res.nh_sel;
1373 frn->type = res.type;
1374 frn->scope = res.scope;
1375 }
1376 local_bh_enable();
1377 }
1378
1379 rcu_read_unlock();
1380}
1381
1382static void nl_fib_input(struct sk_buff *skb)
1383{
1384 struct net *net;
1385 struct fib_result_nl *frn;
1386 struct nlmsghdr *nlh;
1387 u32 portid;
1388
1389 net = sock_net(skb->sk);
1390 nlh = nlmsg_hdr(skb);
1391 if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1392 skb->len < nlh->nlmsg_len ||
1393 nlmsg_len(nlh) < sizeof(*frn))
1394 return;
1395
1396 skb = netlink_skb_clone(skb, GFP_KERNEL);
1397 if (!skb)
1398 return;
1399 nlh = nlmsg_hdr(skb);
1400
1401 frn = nlmsg_data(nlh);
1402 nl_fib_lookup(net, frn);
1403
1404 portid = NETLINK_CB(skb).portid; /* netlink portid */
1405 NETLINK_CB(skb).portid = 0; /* from kernel */
1406 NETLINK_CB(skb).dst_group = 0; /* unicast */
1407 nlmsg_unicast(net->ipv4.fibnl, skb, portid);
1408}
1409
1410static int __net_init nl_fib_lookup_init(struct net *net)
1411{
1412 struct sock *sk;
1413 struct netlink_kernel_cfg cfg = {
1414 .input = nl_fib_input,
1415 };
1416
1417 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1418 if (!sk)
1419 return -EAFNOSUPPORT;
1420 net->ipv4.fibnl = sk;
1421 return 0;
1422}
1423
1424static void nl_fib_lookup_exit(struct net *net)
1425{
1426 netlink_kernel_release(net->ipv4.fibnl);
1427 net->ipv4.fibnl = NULL;
1428}
1429
1430static void fib_disable_ip(struct net_device *dev, unsigned long event,
1431 bool force)
1432{
1433 if (fib_sync_down_dev(dev, event, force))
1434 fib_flush(dev_net(dev));
1435 else
1436 rt_cache_flush(dev_net(dev));
1437 arp_ifdown(dev);
1438}
1439
1440static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1441{
1442 struct in_ifaddr *ifa = ptr;
1443 struct net_device *dev = ifa->ifa_dev->dev;
1444 struct net *net = dev_net(dev);
1445
1446 switch (event) {
1447 case NETDEV_UP:
1448 fib_add_ifaddr(ifa);
1449#ifdef CONFIG_IP_ROUTE_MULTIPATH
1450 fib_sync_up(dev, RTNH_F_DEAD);
1451#endif
1452 atomic_inc(&net->ipv4.dev_addr_genid);
1453 rt_cache_flush(dev_net(dev));
1454 break;
1455 case NETDEV_DOWN:
1456 fib_del_ifaddr(ifa, NULL);
1457 atomic_inc(&net->ipv4.dev_addr_genid);
1458 if (!ifa->ifa_dev->ifa_list) {
1459 /* Last address was deleted from this interface.
1460 * Disable IP.
1461 */
1462 fib_disable_ip(dev, event, true);
1463 } else {
1464 rt_cache_flush(dev_net(dev));
1465 }
1466 break;
1467 }
1468 return NOTIFY_DONE;
1469}
1470
1471static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1472{
1473 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1474 struct netdev_notifier_changeupper_info *upper_info = ptr;
1475 struct netdev_notifier_info_ext *info_ext = ptr;
1476 struct in_device *in_dev;
1477 struct net *net = dev_net(dev);
1478 struct in_ifaddr *ifa;
1479 unsigned int flags;
1480
1481 if (event == NETDEV_UNREGISTER) {
1482 fib_disable_ip(dev, event, true);
1483 rt_flush_dev(dev);
1484 return NOTIFY_DONE;
1485 }
1486
1487 in_dev = __in_dev_get_rtnl(dev);
1488 if (!in_dev)
1489 return NOTIFY_DONE;
1490
1491 switch (event) {
1492 case NETDEV_UP:
1493 in_dev_for_each_ifa_rtnl(ifa, in_dev) {
1494 fib_add_ifaddr(ifa);
1495 }
1496#ifdef CONFIG_IP_ROUTE_MULTIPATH
1497 fib_sync_up(dev, RTNH_F_DEAD);
1498#endif
1499 atomic_inc(&net->ipv4.dev_addr_genid);
1500 rt_cache_flush(net);
1501 break;
1502 case NETDEV_DOWN:
1503 fib_disable_ip(dev, event, false);
1504 break;
1505 case NETDEV_CHANGE:
1506 flags = dev_get_flags(dev);
1507 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1508 fib_sync_up(dev, RTNH_F_LINKDOWN);
1509 else
1510 fib_sync_down_dev(dev, event, false);
1511 rt_cache_flush(net);
1512 break;
1513 case NETDEV_CHANGEMTU:
1514 fib_sync_mtu(dev, info_ext->ext.mtu);
1515 rt_cache_flush(net);
1516 break;
1517 case NETDEV_CHANGEUPPER:
1518 upper_info = ptr;
1519 /* flush all routes if dev is linked to or unlinked from
1520 * an L3 master device (e.g., VRF)
1521 */
1522 if (upper_info->upper_dev &&
1523 netif_is_l3_master(upper_info->upper_dev))
1524 fib_disable_ip(dev, NETDEV_DOWN, true);
1525 break;
1526 }
1527 return NOTIFY_DONE;
1528}
1529
1530static struct notifier_block fib_inetaddr_notifier = {
1531 .notifier_call = fib_inetaddr_event,
1532};
1533
1534static struct notifier_block fib_netdev_notifier = {
1535 .notifier_call = fib_netdev_event,
1536};
1537
1538static int __net_init ip_fib_net_init(struct net *net)
1539{
1540 int err;
1541 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1542
1543 err = fib4_notifier_init(net);
1544 if (err)
1545 return err;
1546
1547#ifdef CONFIG_IP_ROUTE_MULTIPATH
1548 /* Default to 3-tuple */
1549 net->ipv4.sysctl_fib_multipath_hash_fields =
1550 FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK;
1551#endif
1552
1553 /* Avoid false sharing : Use at least a full cache line */
1554 size = max_t(size_t, size, L1_CACHE_BYTES);
1555
1556 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1557 if (!net->ipv4.fib_table_hash) {
1558 err = -ENOMEM;
1559 goto err_table_hash_alloc;
1560 }
1561
1562 err = fib4_rules_init(net);
1563 if (err < 0)
1564 goto err_rules_init;
1565 return 0;
1566
1567err_rules_init:
1568 kfree(net->ipv4.fib_table_hash);
1569err_table_hash_alloc:
1570 fib4_notifier_exit(net);
1571 return err;
1572}
1573
1574static void ip_fib_net_exit(struct net *net)
1575{
1576 int i;
1577
1578 ASSERT_RTNL();
1579#ifdef CONFIG_IP_MULTIPLE_TABLES
1580 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1581 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1582#endif
1583 /* Destroy the tables in reverse order to guarantee that the
1584 * local table, ID 255, is destroyed before the main table, ID
1585 * 254. This is necessary as the local table may contain
1586 * references to data contained in the main table.
1587 */
1588 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1589 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1590 struct hlist_node *tmp;
1591 struct fib_table *tb;
1592
1593 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1594 hlist_del(&tb->tb_hlist);
1595 fib_table_flush(net, tb, true);
1596 fib_free_table(tb);
1597 }
1598 }
1599
1600#ifdef CONFIG_IP_MULTIPLE_TABLES
1601 fib4_rules_exit(net);
1602#endif
1603
1604 kfree(net->ipv4.fib_table_hash);
1605 fib4_notifier_exit(net);
1606}
1607
1608static int __net_init fib_net_init(struct net *net)
1609{
1610 int error;
1611
1612#ifdef CONFIG_IP_ROUTE_CLASSID
1613 atomic_set(&net->ipv4.fib_num_tclassid_users, 0);
1614#endif
1615 error = ip_fib_net_init(net);
1616 if (error < 0)
1617 goto out;
1618 error = nl_fib_lookup_init(net);
1619 if (error < 0)
1620 goto out_nlfl;
1621 error = fib_proc_init(net);
1622 if (error < 0)
1623 goto out_proc;
1624out:
1625 return error;
1626
1627out_proc:
1628 nl_fib_lookup_exit(net);
1629out_nlfl:
1630 rtnl_lock();
1631 ip_fib_net_exit(net);
1632 rtnl_unlock();
1633 goto out;
1634}
1635
1636static void __net_exit fib_net_exit(struct net *net)
1637{
1638 fib_proc_exit(net);
1639 nl_fib_lookup_exit(net);
1640}
1641
1642static void __net_exit fib_net_exit_batch(struct list_head *net_list)
1643{
1644 struct net *net;
1645
1646 rtnl_lock();
1647 list_for_each_entry(net, net_list, exit_list)
1648 ip_fib_net_exit(net);
1649
1650 rtnl_unlock();
1651}
1652
1653static struct pernet_operations fib_net_ops = {
1654 .init = fib_net_init,
1655 .exit = fib_net_exit,
1656 .exit_batch = fib_net_exit_batch,
1657};
1658
1659static const struct rtnl_msg_handler fib_rtnl_msg_handlers[] __initconst = {
1660 {.protocol = PF_INET, .msgtype = RTM_NEWROUTE,
1661 .doit = inet_rtm_newroute},
1662 {.protocol = PF_INET, .msgtype = RTM_DELROUTE,
1663 .doit = inet_rtm_delroute},
1664 {.protocol = PF_INET, .msgtype = RTM_GETROUTE, .dumpit = inet_dump_fib,
1665 .flags = RTNL_FLAG_DUMP_UNLOCKED | RTNL_FLAG_DUMP_SPLIT_NLM_DONE},
1666};
1667
1668void __init ip_fib_init(void)
1669{
1670 fib_trie_init();
1671
1672 register_pernet_subsys(&fib_net_ops);
1673
1674 register_netdevice_notifier(&fib_netdev_notifier);
1675 register_inetaddr_notifier(&fib_inetaddr_notifier);
1676
1677 rtnl_register_many(fib_rtnl_msg_handlers);
1678}
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}