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