Loading...
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/*
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 <asm/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 <trace/events/fib.h>
50
51#ifndef CONFIG_IP_MULTIPLE_TABLES
52
53static int __net_init fib4_rules_init(struct net *net)
54{
55 struct fib_table *local_table, *main_table;
56
57 main_table = fib_trie_table(RT_TABLE_MAIN, NULL);
58 if (!main_table)
59 return -ENOMEM;
60
61 local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
62 if (!local_table)
63 goto fail;
64
65 hlist_add_head_rcu(&local_table->tb_hlist,
66 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
67 hlist_add_head_rcu(&main_table->tb_hlist,
68 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
69 return 0;
70
71fail:
72 fib_free_table(main_table);
73 return -ENOMEM;
74}
75#else
76
77struct fib_table *fib_new_table(struct net *net, u32 id)
78{
79 struct fib_table *tb, *alias = NULL;
80 unsigned int h;
81
82 if (id == 0)
83 id = RT_TABLE_MAIN;
84 tb = fib_get_table(net, id);
85 if (tb)
86 return tb;
87
88 if (id == RT_TABLE_LOCAL)
89 alias = fib_new_table(net, RT_TABLE_MAIN);
90
91 tb = fib_trie_table(id, alias);
92 if (!tb)
93 return NULL;
94
95 switch (id) {
96 case RT_TABLE_LOCAL:
97 rcu_assign_pointer(net->ipv4.fib_local, tb);
98 break;
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}
113
114/* caller must hold either rtnl or rcu read lock */
115struct fib_table *fib_get_table(struct net *net, u32 id)
116{
117 struct fib_table *tb;
118 struct hlist_head *head;
119 unsigned int h;
120
121 if (id == 0)
122 id = RT_TABLE_MAIN;
123 h = id & (FIB_TABLE_HASHSZ - 1);
124
125 head = &net->ipv4.fib_table_hash[h];
126 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
127 if (tb->tb_id == id)
128 return tb;
129 }
130 return NULL;
131}
132#endif /* CONFIG_IP_MULTIPLE_TABLES */
133
134static void fib_replace_table(struct net *net, struct fib_table *old,
135 struct fib_table *new)
136{
137#ifdef CONFIG_IP_MULTIPLE_TABLES
138 switch (new->tb_id) {
139 case RT_TABLE_LOCAL:
140 rcu_assign_pointer(net->ipv4.fib_local, new);
141 break;
142 case RT_TABLE_MAIN:
143 rcu_assign_pointer(net->ipv4.fib_main, new);
144 break;
145 case RT_TABLE_DEFAULT:
146 rcu_assign_pointer(net->ipv4.fib_default, new);
147 break;
148 default:
149 break;
150 }
151
152#endif
153 /* replace the old table in the hlist */
154 hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
155}
156
157int fib_unmerge(struct net *net)
158{
159 struct fib_table *old, *new;
160
161 /* attempt to fetch local table if it has been allocated */
162 old = fib_get_table(net, RT_TABLE_LOCAL);
163 if (!old)
164 return 0;
165
166 new = fib_trie_unmerge(old);
167 if (!new)
168 return -ENOMEM;
169
170 /* replace merged table with clean table */
171 if (new != old) {
172 fib_replace_table(net, old, new);
173 fib_free_table(old);
174 }
175
176 return 0;
177}
178
179static void fib_flush(struct net *net)
180{
181 int flushed = 0;
182 unsigned int h;
183
184 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
185 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
186 struct hlist_node *tmp;
187 struct fib_table *tb;
188
189 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
190 flushed += fib_table_flush(tb);
191 }
192
193 if (flushed)
194 rt_cache_flush(net);
195}
196
197void fib_flush_external(struct net *net)
198{
199 struct fib_table *tb;
200 struct hlist_head *head;
201 unsigned int h;
202
203 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
204 head = &net->ipv4.fib_table_hash[h];
205 hlist_for_each_entry(tb, head, tb_hlist)
206 fib_table_flush_external(tb);
207 }
208}
209
210/*
211 * Find address type as if only "dev" was present in the system. If
212 * on_dev is NULL then all interfaces are taken into consideration.
213 */
214static inline unsigned int __inet_dev_addr_type(struct net *net,
215 const struct net_device *dev,
216 __be32 addr, u32 tb_id)
217{
218 struct flowi4 fl4 = { .daddr = addr };
219 struct fib_result res;
220 unsigned int ret = RTN_BROADCAST;
221 struct fib_table *table;
222
223 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
224 return RTN_BROADCAST;
225 if (ipv4_is_multicast(addr))
226 return RTN_MULTICAST;
227
228 rcu_read_lock();
229
230 table = fib_get_table(net, tb_id);
231 if (table) {
232 ret = RTN_UNICAST;
233 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
234 if (!dev || dev == res.fi->fib_dev)
235 ret = res.type;
236 }
237 }
238
239 rcu_read_unlock();
240 return ret;
241}
242
243unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
244{
245 return __inet_dev_addr_type(net, NULL, addr, tb_id);
246}
247EXPORT_SYMBOL(inet_addr_type_table);
248
249unsigned int inet_addr_type(struct net *net, __be32 addr)
250{
251 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
252}
253EXPORT_SYMBOL(inet_addr_type);
254
255unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
256 __be32 addr)
257{
258 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
259
260 return __inet_dev_addr_type(net, dev, addr, rt_table);
261}
262EXPORT_SYMBOL(inet_dev_addr_type);
263
264/* inet_addr_type with dev == NULL but using the table from a dev
265 * if one is associated
266 */
267unsigned int inet_addr_type_dev_table(struct net *net,
268 const struct net_device *dev,
269 __be32 addr)
270{
271 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
272
273 return __inet_dev_addr_type(net, NULL, addr, rt_table);
274}
275EXPORT_SYMBOL(inet_addr_type_dev_table);
276
277__be32 fib_compute_spec_dst(struct sk_buff *skb)
278{
279 struct net_device *dev = skb->dev;
280 struct in_device *in_dev;
281 struct fib_result res;
282 struct rtable *rt;
283 struct net *net;
284 int scope;
285
286 rt = skb_rtable(skb);
287 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
288 RTCF_LOCAL)
289 return ip_hdr(skb)->daddr;
290
291 in_dev = __in_dev_get_rcu(dev);
292 BUG_ON(!in_dev);
293
294 net = dev_net(dev);
295
296 scope = RT_SCOPE_UNIVERSE;
297 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
298 struct flowi4 fl4 = {
299 .flowi4_iif = LOOPBACK_IFINDEX,
300 .daddr = ip_hdr(skb)->saddr,
301 .flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
302 .flowi4_scope = scope,
303 .flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0,
304 };
305 if (!fib_lookup(net, &fl4, &res, 0))
306 return FIB_RES_PREFSRC(net, res);
307 } else {
308 scope = RT_SCOPE_LINK;
309 }
310
311 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
312}
313
314/* Given (packet source, input interface) and optional (dst, oif, tos):
315 * - (main) check, that source is valid i.e. not broadcast or our local
316 * address.
317 * - figure out what "logical" interface this packet arrived
318 * and calculate "specific destination" address.
319 * - check, that packet arrived from expected physical interface.
320 * called with rcu_read_lock()
321 */
322static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
323 u8 tos, int oif, struct net_device *dev,
324 int rpf, struct in_device *idev, u32 *itag)
325{
326 int ret, no_addr;
327 struct fib_result res;
328 struct flowi4 fl4;
329 struct net *net;
330 bool dev_match;
331
332 fl4.flowi4_oif = 0;
333 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
334 if (!fl4.flowi4_iif)
335 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
336 fl4.daddr = src;
337 fl4.saddr = dst;
338 fl4.flowi4_tos = tos;
339 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
340 fl4.flowi4_tun_key.tun_id = 0;
341 fl4.flowi4_flags = 0;
342
343 no_addr = idev->ifa_list == NULL;
344
345 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
346
347 trace_fib_validate_source(dev, &fl4);
348
349 net = dev_net(dev);
350 if (fib_lookup(net, &fl4, &res, 0))
351 goto last_resort;
352 if (res.type != RTN_UNICAST &&
353 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
354 goto e_inval;
355 if (!rpf && !fib_num_tclassid_users(dev_net(dev)) &&
356 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev)))
357 goto last_resort;
358 fib_combine_itag(itag, &res);
359 dev_match = false;
360
361#ifdef CONFIG_IP_ROUTE_MULTIPATH
362 for (ret = 0; ret < res.fi->fib_nhs; ret++) {
363 struct fib_nh *nh = &res.fi->fib_nh[ret];
364
365 if (nh->nh_dev == dev) {
366 dev_match = true;
367 break;
368 } else if (l3mdev_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
369 dev_match = true;
370 break;
371 }
372 }
373#else
374 if (FIB_RES_DEV(res) == dev)
375 dev_match = true;
376#endif
377 if (dev_match) {
378 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
379 return ret;
380 }
381 if (no_addr)
382 goto last_resort;
383 if (rpf == 1)
384 goto e_rpf;
385 fl4.flowi4_oif = dev->ifindex;
386
387 ret = 0;
388 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
389 if (res.type == RTN_UNICAST)
390 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
391 }
392 return ret;
393
394last_resort:
395 if (rpf)
396 goto e_rpf;
397 *itag = 0;
398 return 0;
399
400e_inval:
401 return -EINVAL;
402e_rpf:
403 return -EXDEV;
404}
405
406/* Ignore rp_filter for packets protected by IPsec. */
407int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
408 u8 tos, int oif, struct net_device *dev,
409 struct in_device *idev, u32 *itag)
410{
411 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
412
413 if (!r && !fib_num_tclassid_users(dev_net(dev)) &&
414 IN_DEV_ACCEPT_LOCAL(idev) &&
415 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
416 *itag = 0;
417 return 0;
418 }
419 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
420}
421
422static inline __be32 sk_extract_addr(struct sockaddr *addr)
423{
424 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
425}
426
427static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
428{
429 struct nlattr *nla;
430
431 nla = (struct nlattr *) ((char *) mx + len);
432 nla->nla_type = type;
433 nla->nla_len = nla_attr_size(4);
434 *(u32 *) nla_data(nla) = value;
435
436 return len + nla_total_size(4);
437}
438
439static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
440 struct fib_config *cfg)
441{
442 __be32 addr;
443 int plen;
444
445 memset(cfg, 0, sizeof(*cfg));
446 cfg->fc_nlinfo.nl_net = net;
447
448 if (rt->rt_dst.sa_family != AF_INET)
449 return -EAFNOSUPPORT;
450
451 /*
452 * Check mask for validity:
453 * a) it must be contiguous.
454 * b) destination must have all host bits clear.
455 * c) if application forgot to set correct family (AF_INET),
456 * reject request unless it is absolutely clear i.e.
457 * both family and mask are zero.
458 */
459 plen = 32;
460 addr = sk_extract_addr(&rt->rt_dst);
461 if (!(rt->rt_flags & RTF_HOST)) {
462 __be32 mask = sk_extract_addr(&rt->rt_genmask);
463
464 if (rt->rt_genmask.sa_family != AF_INET) {
465 if (mask || rt->rt_genmask.sa_family)
466 return -EAFNOSUPPORT;
467 }
468
469 if (bad_mask(mask, addr))
470 return -EINVAL;
471
472 plen = inet_mask_len(mask);
473 }
474
475 cfg->fc_dst_len = plen;
476 cfg->fc_dst = addr;
477
478 if (cmd != SIOCDELRT) {
479 cfg->fc_nlflags = NLM_F_CREATE;
480 cfg->fc_protocol = RTPROT_BOOT;
481 }
482
483 if (rt->rt_metric)
484 cfg->fc_priority = rt->rt_metric - 1;
485
486 if (rt->rt_flags & RTF_REJECT) {
487 cfg->fc_scope = RT_SCOPE_HOST;
488 cfg->fc_type = RTN_UNREACHABLE;
489 return 0;
490 }
491
492 cfg->fc_scope = RT_SCOPE_NOWHERE;
493 cfg->fc_type = RTN_UNICAST;
494
495 if (rt->rt_dev) {
496 char *colon;
497 struct net_device *dev;
498 char devname[IFNAMSIZ];
499
500 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
501 return -EFAULT;
502
503 devname[IFNAMSIZ-1] = 0;
504 colon = strchr(devname, ':');
505 if (colon)
506 *colon = 0;
507 dev = __dev_get_by_name(net, devname);
508 if (!dev)
509 return -ENODEV;
510 cfg->fc_oif = dev->ifindex;
511 if (colon) {
512 struct in_ifaddr *ifa;
513 struct in_device *in_dev = __in_dev_get_rtnl(dev);
514 if (!in_dev)
515 return -ENODEV;
516 *colon = ':';
517 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
518 if (strcmp(ifa->ifa_label, devname) == 0)
519 break;
520 if (!ifa)
521 return -ENODEV;
522 cfg->fc_prefsrc = ifa->ifa_local;
523 }
524 }
525
526 addr = sk_extract_addr(&rt->rt_gateway);
527 if (rt->rt_gateway.sa_family == AF_INET && addr) {
528 unsigned int addr_type;
529
530 cfg->fc_gw = addr;
531 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
532 if (rt->rt_flags & RTF_GATEWAY &&
533 addr_type == RTN_UNICAST)
534 cfg->fc_scope = RT_SCOPE_UNIVERSE;
535 }
536
537 if (cmd == SIOCDELRT)
538 return 0;
539
540 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
541 return -EINVAL;
542
543 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
544 cfg->fc_scope = RT_SCOPE_LINK;
545
546 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
547 struct nlattr *mx;
548 int len = 0;
549
550 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
551 if (!mx)
552 return -ENOMEM;
553
554 if (rt->rt_flags & RTF_MTU)
555 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
556
557 if (rt->rt_flags & RTF_WINDOW)
558 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
559
560 if (rt->rt_flags & RTF_IRTT)
561 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
562
563 cfg->fc_mx = mx;
564 cfg->fc_mx_len = len;
565 }
566
567 return 0;
568}
569
570/*
571 * Handle IP routing ioctl calls.
572 * These are used to manipulate the routing tables
573 */
574int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
575{
576 struct fib_config cfg;
577 struct rtentry rt;
578 int err;
579
580 switch (cmd) {
581 case SIOCADDRT: /* Add a route */
582 case SIOCDELRT: /* Delete a route */
583 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
584 return -EPERM;
585
586 if (copy_from_user(&rt, arg, sizeof(rt)))
587 return -EFAULT;
588
589 rtnl_lock();
590 err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
591 if (err == 0) {
592 struct fib_table *tb;
593
594 if (cmd == SIOCDELRT) {
595 tb = fib_get_table(net, cfg.fc_table);
596 if (tb)
597 err = fib_table_delete(tb, &cfg);
598 else
599 err = -ESRCH;
600 } else {
601 tb = fib_new_table(net, cfg.fc_table);
602 if (tb)
603 err = fib_table_insert(tb, &cfg);
604 else
605 err = -ENOBUFS;
606 }
607
608 /* allocated by rtentry_to_fib_config() */
609 kfree(cfg.fc_mx);
610 }
611 rtnl_unlock();
612 return err;
613 }
614 return -EINVAL;
615}
616
617const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
618 [RTA_DST] = { .type = NLA_U32 },
619 [RTA_SRC] = { .type = NLA_U32 },
620 [RTA_IIF] = { .type = NLA_U32 },
621 [RTA_OIF] = { .type = NLA_U32 },
622 [RTA_GATEWAY] = { .type = NLA_U32 },
623 [RTA_PRIORITY] = { .type = NLA_U32 },
624 [RTA_PREFSRC] = { .type = NLA_U32 },
625 [RTA_METRICS] = { .type = NLA_NESTED },
626 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
627 [RTA_FLOW] = { .type = NLA_U32 },
628 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
629 [RTA_ENCAP] = { .type = NLA_NESTED },
630};
631
632static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
633 struct nlmsghdr *nlh, struct fib_config *cfg)
634{
635 struct nlattr *attr;
636 int err, remaining;
637 struct rtmsg *rtm;
638
639 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
640 if (err < 0)
641 goto errout;
642
643 memset(cfg, 0, sizeof(*cfg));
644
645 rtm = nlmsg_data(nlh);
646 cfg->fc_dst_len = rtm->rtm_dst_len;
647 cfg->fc_tos = rtm->rtm_tos;
648 cfg->fc_table = rtm->rtm_table;
649 cfg->fc_protocol = rtm->rtm_protocol;
650 cfg->fc_scope = rtm->rtm_scope;
651 cfg->fc_type = rtm->rtm_type;
652 cfg->fc_flags = rtm->rtm_flags;
653 cfg->fc_nlflags = nlh->nlmsg_flags;
654
655 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
656 cfg->fc_nlinfo.nlh = nlh;
657 cfg->fc_nlinfo.nl_net = net;
658
659 if (cfg->fc_type > RTN_MAX) {
660 err = -EINVAL;
661 goto errout;
662 }
663
664 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
665 switch (nla_type(attr)) {
666 case RTA_DST:
667 cfg->fc_dst = nla_get_be32(attr);
668 break;
669 case RTA_OIF:
670 cfg->fc_oif = nla_get_u32(attr);
671 break;
672 case RTA_GATEWAY:
673 cfg->fc_gw = nla_get_be32(attr);
674 break;
675 case RTA_PRIORITY:
676 cfg->fc_priority = nla_get_u32(attr);
677 break;
678 case RTA_PREFSRC:
679 cfg->fc_prefsrc = nla_get_be32(attr);
680 break;
681 case RTA_METRICS:
682 cfg->fc_mx = nla_data(attr);
683 cfg->fc_mx_len = nla_len(attr);
684 break;
685 case RTA_MULTIPATH:
686 cfg->fc_mp = nla_data(attr);
687 cfg->fc_mp_len = nla_len(attr);
688 break;
689 case RTA_FLOW:
690 cfg->fc_flow = nla_get_u32(attr);
691 break;
692 case RTA_TABLE:
693 cfg->fc_table = nla_get_u32(attr);
694 break;
695 case RTA_ENCAP:
696 cfg->fc_encap = attr;
697 break;
698 case RTA_ENCAP_TYPE:
699 cfg->fc_encap_type = nla_get_u16(attr);
700 break;
701 }
702 }
703
704 return 0;
705errout:
706 return err;
707}
708
709static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
710{
711 struct net *net = sock_net(skb->sk);
712 struct fib_config cfg;
713 struct fib_table *tb;
714 int err;
715
716 err = rtm_to_fib_config(net, skb, nlh, &cfg);
717 if (err < 0)
718 goto errout;
719
720 tb = fib_get_table(net, cfg.fc_table);
721 if (!tb) {
722 err = -ESRCH;
723 goto errout;
724 }
725
726 err = fib_table_delete(tb, &cfg);
727errout:
728 return err;
729}
730
731static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
732{
733 struct net *net = sock_net(skb->sk);
734 struct fib_config cfg;
735 struct fib_table *tb;
736 int err;
737
738 err = rtm_to_fib_config(net, skb, nlh, &cfg);
739 if (err < 0)
740 goto errout;
741
742 tb = fib_new_table(net, cfg.fc_table);
743 if (!tb) {
744 err = -ENOBUFS;
745 goto errout;
746 }
747
748 err = fib_table_insert(tb, &cfg);
749errout:
750 return err;
751}
752
753static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
754{
755 struct net *net = sock_net(skb->sk);
756 unsigned int h, s_h;
757 unsigned int e = 0, s_e;
758 struct fib_table *tb;
759 struct hlist_head *head;
760 int dumped = 0;
761
762 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
763 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
764 return skb->len;
765
766 s_h = cb->args[0];
767 s_e = cb->args[1];
768
769 rcu_read_lock();
770
771 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
772 e = 0;
773 head = &net->ipv4.fib_table_hash[h];
774 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
775 if (e < s_e)
776 goto next;
777 if (dumped)
778 memset(&cb->args[2], 0, sizeof(cb->args) -
779 2 * sizeof(cb->args[0]));
780 if (fib_table_dump(tb, skb, cb) < 0)
781 goto out;
782 dumped = 1;
783next:
784 e++;
785 }
786 }
787out:
788 rcu_read_unlock();
789
790 cb->args[1] = e;
791 cb->args[0] = h;
792
793 return skb->len;
794}
795
796/* Prepare and feed intra-kernel routing request.
797 * Really, it should be netlink message, but :-( netlink
798 * can be not configured, so that we feed it directly
799 * to fib engine. It is legal, because all events occur
800 * only when netlink is already locked.
801 */
802static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
803{
804 struct net *net = dev_net(ifa->ifa_dev->dev);
805 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
806 struct fib_table *tb;
807 struct fib_config cfg = {
808 .fc_protocol = RTPROT_KERNEL,
809 .fc_type = type,
810 .fc_dst = dst,
811 .fc_dst_len = dst_len,
812 .fc_prefsrc = ifa->ifa_local,
813 .fc_oif = ifa->ifa_dev->dev->ifindex,
814 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
815 .fc_nlinfo = {
816 .nl_net = net,
817 },
818 };
819
820 if (!tb_id)
821 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
822
823 tb = fib_new_table(net, tb_id);
824 if (!tb)
825 return;
826
827 cfg.fc_table = tb->tb_id;
828
829 if (type != RTN_LOCAL)
830 cfg.fc_scope = RT_SCOPE_LINK;
831 else
832 cfg.fc_scope = RT_SCOPE_HOST;
833
834 if (cmd == RTM_NEWROUTE)
835 fib_table_insert(tb, &cfg);
836 else
837 fib_table_delete(tb, &cfg);
838}
839
840void fib_add_ifaddr(struct in_ifaddr *ifa)
841{
842 struct in_device *in_dev = ifa->ifa_dev;
843 struct net_device *dev = in_dev->dev;
844 struct in_ifaddr *prim = ifa;
845 __be32 mask = ifa->ifa_mask;
846 __be32 addr = ifa->ifa_local;
847 __be32 prefix = ifa->ifa_address & mask;
848
849 if (ifa->ifa_flags & IFA_F_SECONDARY) {
850 prim = inet_ifa_byprefix(in_dev, prefix, mask);
851 if (!prim) {
852 pr_warn("%s: bug: prim == NULL\n", __func__);
853 return;
854 }
855 }
856
857 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
858
859 if (!(dev->flags & IFF_UP))
860 return;
861
862 /* Add broadcast address, if it is explicitly assigned. */
863 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
864 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
865
866 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
867 (prefix != addr || ifa->ifa_prefixlen < 32)) {
868 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
869 fib_magic(RTM_NEWROUTE,
870 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
871 prefix, ifa->ifa_prefixlen, prim);
872
873 /* Add network specific broadcasts, when it takes a sense */
874 if (ifa->ifa_prefixlen < 31) {
875 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
876 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
877 32, prim);
878 }
879 }
880}
881
882/* Delete primary or secondary address.
883 * Optionally, on secondary address promotion consider the addresses
884 * from subnet iprim as deleted, even if they are in device list.
885 * In this case the secondary ifa can be in device list.
886 */
887void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
888{
889 struct in_device *in_dev = ifa->ifa_dev;
890 struct net_device *dev = in_dev->dev;
891 struct in_ifaddr *ifa1;
892 struct in_ifaddr *prim = ifa, *prim1 = NULL;
893 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
894 __be32 any = ifa->ifa_address & ifa->ifa_mask;
895#define LOCAL_OK 1
896#define BRD_OK 2
897#define BRD0_OK 4
898#define BRD1_OK 8
899 unsigned int ok = 0;
900 int subnet = 0; /* Primary network */
901 int gone = 1; /* Address is missing */
902 int same_prefsrc = 0; /* Another primary with same IP */
903
904 if (ifa->ifa_flags & IFA_F_SECONDARY) {
905 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
906 if (!prim) {
907 /* if the device has been deleted, we don't perform
908 * address promotion
909 */
910 if (!in_dev->dead)
911 pr_warn("%s: bug: prim == NULL\n", __func__);
912 return;
913 }
914 if (iprim && iprim != prim) {
915 pr_warn("%s: bug: iprim != prim\n", __func__);
916 return;
917 }
918 } else if (!ipv4_is_zeronet(any) &&
919 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
920 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
921 fib_magic(RTM_DELROUTE,
922 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
923 any, ifa->ifa_prefixlen, prim);
924 subnet = 1;
925 }
926
927 if (in_dev->dead)
928 goto no_promotions;
929
930 /* Deletion is more complicated than add.
931 * We should take care of not to delete too much :-)
932 *
933 * Scan address list to be sure that addresses are really gone.
934 */
935
936 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
937 if (ifa1 == ifa) {
938 /* promotion, keep the IP */
939 gone = 0;
940 continue;
941 }
942 /* Ignore IFAs from our subnet */
943 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
944 inet_ifa_match(ifa1->ifa_address, iprim))
945 continue;
946
947 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
948 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
949 /* Another address from our subnet? */
950 if (ifa1->ifa_mask == prim->ifa_mask &&
951 inet_ifa_match(ifa1->ifa_address, prim))
952 prim1 = prim;
953 else {
954 /* We reached the secondaries, so
955 * same_prefsrc should be determined.
956 */
957 if (!same_prefsrc)
958 continue;
959 /* Search new prim1 if ifa1 is not
960 * using the current prim1
961 */
962 if (!prim1 ||
963 ifa1->ifa_mask != prim1->ifa_mask ||
964 !inet_ifa_match(ifa1->ifa_address, prim1))
965 prim1 = inet_ifa_byprefix(in_dev,
966 ifa1->ifa_address,
967 ifa1->ifa_mask);
968 if (!prim1)
969 continue;
970 if (prim1->ifa_local != prim->ifa_local)
971 continue;
972 }
973 } else {
974 if (prim->ifa_local != ifa1->ifa_local)
975 continue;
976 prim1 = ifa1;
977 if (prim != prim1)
978 same_prefsrc = 1;
979 }
980 if (ifa->ifa_local == ifa1->ifa_local)
981 ok |= LOCAL_OK;
982 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
983 ok |= BRD_OK;
984 if (brd == ifa1->ifa_broadcast)
985 ok |= BRD1_OK;
986 if (any == ifa1->ifa_broadcast)
987 ok |= BRD0_OK;
988 /* primary has network specific broadcasts */
989 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
990 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
991 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
992
993 if (!ipv4_is_zeronet(any1)) {
994 if (ifa->ifa_broadcast == brd1 ||
995 ifa->ifa_broadcast == any1)
996 ok |= BRD_OK;
997 if (brd == brd1 || brd == any1)
998 ok |= BRD1_OK;
999 if (any == brd1 || any == any1)
1000 ok |= BRD0_OK;
1001 }
1002 }
1003 }
1004
1005no_promotions:
1006 if (!(ok & BRD_OK))
1007 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
1008 if (subnet && ifa->ifa_prefixlen < 31) {
1009 if (!(ok & BRD1_OK))
1010 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
1011 if (!(ok & BRD0_OK))
1012 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
1013 }
1014 if (!(ok & LOCAL_OK)) {
1015 unsigned int addr_type;
1016
1017 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
1018
1019 /* Check, that this local address finally disappeared. */
1020 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1021 ifa->ifa_local);
1022 if (gone && addr_type != RTN_LOCAL) {
1023 /* And the last, but not the least thing.
1024 * We must flush stray FIB entries.
1025 *
1026 * First of all, we scan fib_info list searching
1027 * for stray nexthop entries, then ignite fib_flush.
1028 */
1029 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
1030 fib_flush(dev_net(dev));
1031 }
1032 }
1033#undef LOCAL_OK
1034#undef BRD_OK
1035#undef BRD0_OK
1036#undef BRD1_OK
1037}
1038
1039static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1040{
1041
1042 struct fib_result res;
1043 struct flowi4 fl4 = {
1044 .flowi4_mark = frn->fl_mark,
1045 .daddr = frn->fl_addr,
1046 .flowi4_tos = frn->fl_tos,
1047 .flowi4_scope = frn->fl_scope,
1048 };
1049 struct fib_table *tb;
1050
1051 rcu_read_lock();
1052
1053 tb = fib_get_table(net, frn->tb_id_in);
1054
1055 frn->err = -ENOENT;
1056 if (tb) {
1057 local_bh_disable();
1058
1059 frn->tb_id = tb->tb_id;
1060 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1061
1062 if (!frn->err) {
1063 frn->prefixlen = res.prefixlen;
1064 frn->nh_sel = res.nh_sel;
1065 frn->type = res.type;
1066 frn->scope = res.scope;
1067 }
1068 local_bh_enable();
1069 }
1070
1071 rcu_read_unlock();
1072}
1073
1074static void nl_fib_input(struct sk_buff *skb)
1075{
1076 struct net *net;
1077 struct fib_result_nl *frn;
1078 struct nlmsghdr *nlh;
1079 u32 portid;
1080
1081 net = sock_net(skb->sk);
1082 nlh = nlmsg_hdr(skb);
1083 if (skb->len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len ||
1084 nlmsg_len(nlh) < sizeof(*frn))
1085 return;
1086
1087 skb = netlink_skb_clone(skb, GFP_KERNEL);
1088 if (!skb)
1089 return;
1090 nlh = nlmsg_hdr(skb);
1091
1092 frn = (struct fib_result_nl *) nlmsg_data(nlh);
1093 nl_fib_lookup(net, frn);
1094
1095 portid = NETLINK_CB(skb).portid; /* netlink portid */
1096 NETLINK_CB(skb).portid = 0; /* from kernel */
1097 NETLINK_CB(skb).dst_group = 0; /* unicast */
1098 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1099}
1100
1101static int __net_init nl_fib_lookup_init(struct net *net)
1102{
1103 struct sock *sk;
1104 struct netlink_kernel_cfg cfg = {
1105 .input = nl_fib_input,
1106 };
1107
1108 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1109 if (!sk)
1110 return -EAFNOSUPPORT;
1111 net->ipv4.fibnl = sk;
1112 return 0;
1113}
1114
1115static void nl_fib_lookup_exit(struct net *net)
1116{
1117 netlink_kernel_release(net->ipv4.fibnl);
1118 net->ipv4.fibnl = NULL;
1119}
1120
1121static void fib_disable_ip(struct net_device *dev, unsigned long event,
1122 bool force)
1123{
1124 if (fib_sync_down_dev(dev, event, force))
1125 fib_flush(dev_net(dev));
1126 rt_cache_flush(dev_net(dev));
1127 arp_ifdown(dev);
1128}
1129
1130static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1131{
1132 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1133 struct net_device *dev = ifa->ifa_dev->dev;
1134 struct net *net = dev_net(dev);
1135
1136 switch (event) {
1137 case NETDEV_UP:
1138 fib_add_ifaddr(ifa);
1139#ifdef CONFIG_IP_ROUTE_MULTIPATH
1140 fib_sync_up(dev, RTNH_F_DEAD);
1141#endif
1142 atomic_inc(&net->ipv4.dev_addr_genid);
1143 rt_cache_flush(dev_net(dev));
1144 break;
1145 case NETDEV_DOWN:
1146 fib_del_ifaddr(ifa, NULL);
1147 atomic_inc(&net->ipv4.dev_addr_genid);
1148 if (!ifa->ifa_dev->ifa_list) {
1149 /* Last address was deleted from this interface.
1150 * Disable IP.
1151 */
1152 fib_disable_ip(dev, event, true);
1153 } else {
1154 rt_cache_flush(dev_net(dev));
1155 }
1156 break;
1157 }
1158 return NOTIFY_DONE;
1159}
1160
1161static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1162{
1163 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1164 struct netdev_notifier_changeupper_info *info;
1165 struct in_device *in_dev;
1166 struct net *net = dev_net(dev);
1167 unsigned int flags;
1168
1169 if (event == NETDEV_UNREGISTER) {
1170 fib_disable_ip(dev, event, true);
1171 rt_flush_dev(dev);
1172 return NOTIFY_DONE;
1173 }
1174
1175 in_dev = __in_dev_get_rtnl(dev);
1176 if (!in_dev)
1177 return NOTIFY_DONE;
1178
1179 switch (event) {
1180 case NETDEV_UP:
1181 for_ifa(in_dev) {
1182 fib_add_ifaddr(ifa);
1183 } endfor_ifa(in_dev);
1184#ifdef CONFIG_IP_ROUTE_MULTIPATH
1185 fib_sync_up(dev, RTNH_F_DEAD);
1186#endif
1187 atomic_inc(&net->ipv4.dev_addr_genid);
1188 rt_cache_flush(net);
1189 break;
1190 case NETDEV_DOWN:
1191 fib_disable_ip(dev, event, false);
1192 break;
1193 case NETDEV_CHANGE:
1194 flags = dev_get_flags(dev);
1195 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1196 fib_sync_up(dev, RTNH_F_LINKDOWN);
1197 else
1198 fib_sync_down_dev(dev, event, false);
1199 /* fall through */
1200 case NETDEV_CHANGEMTU:
1201 rt_cache_flush(net);
1202 break;
1203 case NETDEV_CHANGEUPPER:
1204 info = ptr;
1205 /* flush all routes if dev is linked to or unlinked from
1206 * an L3 master device (e.g., VRF)
1207 */
1208 if (info->upper_dev && netif_is_l3_master(info->upper_dev))
1209 fib_disable_ip(dev, NETDEV_DOWN, true);
1210 break;
1211 }
1212 return NOTIFY_DONE;
1213}
1214
1215static struct notifier_block fib_inetaddr_notifier = {
1216 .notifier_call = fib_inetaddr_event,
1217};
1218
1219static struct notifier_block fib_netdev_notifier = {
1220 .notifier_call = fib_netdev_event,
1221};
1222
1223static int __net_init ip_fib_net_init(struct net *net)
1224{
1225 int err;
1226 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1227
1228 /* Avoid false sharing : Use at least a full cache line */
1229 size = max_t(size_t, size, L1_CACHE_BYTES);
1230
1231 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1232 if (!net->ipv4.fib_table_hash)
1233 return -ENOMEM;
1234
1235 err = fib4_rules_init(net);
1236 if (err < 0)
1237 goto fail;
1238 return 0;
1239
1240fail:
1241 kfree(net->ipv4.fib_table_hash);
1242 return err;
1243}
1244
1245static void ip_fib_net_exit(struct net *net)
1246{
1247 unsigned int i;
1248
1249 rtnl_lock();
1250#ifdef CONFIG_IP_MULTIPLE_TABLES
1251 RCU_INIT_POINTER(net->ipv4.fib_local, NULL);
1252 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1253 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1254#endif
1255 for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1256 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1257 struct hlist_node *tmp;
1258 struct fib_table *tb;
1259
1260 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1261 hlist_del(&tb->tb_hlist);
1262 fib_table_flush(tb);
1263 fib_free_table(tb);
1264 }
1265 }
1266
1267#ifdef CONFIG_IP_MULTIPLE_TABLES
1268 fib4_rules_exit(net);
1269#endif
1270 rtnl_unlock();
1271 kfree(net->ipv4.fib_table_hash);
1272}
1273
1274static int __net_init fib_net_init(struct net *net)
1275{
1276 int error;
1277
1278#ifdef CONFIG_IP_ROUTE_CLASSID
1279 net->ipv4.fib_num_tclassid_users = 0;
1280#endif
1281 error = ip_fib_net_init(net);
1282 if (error < 0)
1283 goto out;
1284 error = nl_fib_lookup_init(net);
1285 if (error < 0)
1286 goto out_nlfl;
1287 error = fib_proc_init(net);
1288 if (error < 0)
1289 goto out_proc;
1290out:
1291 return error;
1292
1293out_proc:
1294 nl_fib_lookup_exit(net);
1295out_nlfl:
1296 ip_fib_net_exit(net);
1297 goto out;
1298}
1299
1300static void __net_exit fib_net_exit(struct net *net)
1301{
1302 fib_proc_exit(net);
1303 nl_fib_lookup_exit(net);
1304 ip_fib_net_exit(net);
1305}
1306
1307static struct pernet_operations fib_net_ops = {
1308 .init = fib_net_init,
1309 .exit = fib_net_exit,
1310};
1311
1312void __init ip_fib_init(void)
1313{
1314 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1315 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1316 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1317
1318 register_pernet_subsys(&fib_net_ops);
1319 register_netdevice_notifier(&fib_netdev_notifier);
1320 register_inetaddr_notifier(&fib_inetaddr_notifier);
1321
1322 fib_trie_init();
1323}