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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 <asm/system.h>
19#include <linux/bitops.h>
20#include <linux/capability.h>
21#include <linux/types.h>
22#include <linux/kernel.h>
23#include <linux/mm.h>
24#include <linux/string.h>
25#include <linux/socket.h>
26#include <linux/sockios.h>
27#include <linux/errno.h>
28#include <linux/in.h>
29#include <linux/inet.h>
30#include <linux/inetdevice.h>
31#include <linux/netdevice.h>
32#include <linux/if_addr.h>
33#include <linux/if_arp.h>
34#include <linux/skbuff.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
49#ifndef CONFIG_IP_MULTIPLE_TABLES
50
51static int __net_init fib4_rules_init(struct net *net)
52{
53 struct fib_table *local_table, *main_table;
54
55 local_table = fib_trie_table(RT_TABLE_LOCAL);
56 if (local_table == NULL)
57 return -ENOMEM;
58
59 main_table = fib_trie_table(RT_TABLE_MAIN);
60 if (main_table == NULL)
61 goto fail;
62
63 hlist_add_head_rcu(&local_table->tb_hlist,
64 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
65 hlist_add_head_rcu(&main_table->tb_hlist,
66 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
67 return 0;
68
69fail:
70 kfree(local_table);
71 return -ENOMEM;
72}
73#else
74
75struct fib_table *fib_new_table(struct net *net, u32 id)
76{
77 struct fib_table *tb;
78 unsigned int h;
79
80 if (id == 0)
81 id = RT_TABLE_MAIN;
82 tb = fib_get_table(net, id);
83 if (tb)
84 return tb;
85
86 tb = fib_trie_table(id);
87 if (!tb)
88 return NULL;
89 h = id & (FIB_TABLE_HASHSZ - 1);
90 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
91 return tb;
92}
93
94struct fib_table *fib_get_table(struct net *net, u32 id)
95{
96 struct fib_table *tb;
97 struct hlist_node *node;
98 struct hlist_head *head;
99 unsigned int h;
100
101 if (id == 0)
102 id = RT_TABLE_MAIN;
103 h = id & (FIB_TABLE_HASHSZ - 1);
104
105 rcu_read_lock();
106 head = &net->ipv4.fib_table_hash[h];
107 hlist_for_each_entry_rcu(tb, node, head, tb_hlist) {
108 if (tb->tb_id == id) {
109 rcu_read_unlock();
110 return tb;
111 }
112 }
113 rcu_read_unlock();
114 return NULL;
115}
116#endif /* CONFIG_IP_MULTIPLE_TABLES */
117
118static void fib_flush(struct net *net)
119{
120 int flushed = 0;
121 struct fib_table *tb;
122 struct hlist_node *node;
123 struct hlist_head *head;
124 unsigned int h;
125
126 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
127 head = &net->ipv4.fib_table_hash[h];
128 hlist_for_each_entry(tb, node, head, tb_hlist)
129 flushed += fib_table_flush(tb);
130 }
131
132 if (flushed)
133 rt_cache_flush(net, -1);
134}
135
136/*
137 * Find address type as if only "dev" was present in the system. If
138 * on_dev is NULL then all interfaces are taken into consideration.
139 */
140static inline unsigned __inet_dev_addr_type(struct net *net,
141 const struct net_device *dev,
142 __be32 addr)
143{
144 struct flowi4 fl4 = { .daddr = addr };
145 struct fib_result res;
146 unsigned ret = RTN_BROADCAST;
147 struct fib_table *local_table;
148
149 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
150 return RTN_BROADCAST;
151 if (ipv4_is_multicast(addr))
152 return RTN_MULTICAST;
153
154#ifdef CONFIG_IP_MULTIPLE_TABLES
155 res.r = NULL;
156#endif
157
158 local_table = fib_get_table(net, RT_TABLE_LOCAL);
159 if (local_table) {
160 ret = RTN_UNICAST;
161 rcu_read_lock();
162 if (!fib_table_lookup(local_table, &fl4, &res, FIB_LOOKUP_NOREF)) {
163 if (!dev || dev == res.fi->fib_dev)
164 ret = res.type;
165 }
166 rcu_read_unlock();
167 }
168 return ret;
169}
170
171unsigned int inet_addr_type(struct net *net, __be32 addr)
172{
173 return __inet_dev_addr_type(net, NULL, addr);
174}
175EXPORT_SYMBOL(inet_addr_type);
176
177unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
178 __be32 addr)
179{
180 return __inet_dev_addr_type(net, dev, addr);
181}
182EXPORT_SYMBOL(inet_dev_addr_type);
183
184/* Given (packet source, input interface) and optional (dst, oif, tos):
185 * - (main) check, that source is valid i.e. not broadcast or our local
186 * address.
187 * - figure out what "logical" interface this packet arrived
188 * and calculate "specific destination" address.
189 * - check, that packet arrived from expected physical interface.
190 * called with rcu_read_lock()
191 */
192int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, u8 tos,
193 int oif, struct net_device *dev, __be32 *spec_dst,
194 u32 *itag)
195{
196 struct in_device *in_dev;
197 struct flowi4 fl4;
198 struct fib_result res;
199 int no_addr, rpf, accept_local;
200 bool dev_match;
201 int ret;
202 struct net *net;
203
204 fl4.flowi4_oif = 0;
205 fl4.flowi4_iif = oif;
206 fl4.daddr = src;
207 fl4.saddr = dst;
208 fl4.flowi4_tos = tos;
209 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
210
211 no_addr = rpf = accept_local = 0;
212 in_dev = __in_dev_get_rcu(dev);
213 if (in_dev) {
214 no_addr = in_dev->ifa_list == NULL;
215
216 /* Ignore rp_filter for packets protected by IPsec. */
217 rpf = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(in_dev);
218
219 accept_local = IN_DEV_ACCEPT_LOCAL(in_dev);
220 fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0;
221 }
222
223 if (in_dev == NULL)
224 goto e_inval;
225
226 net = dev_net(dev);
227 if (fib_lookup(net, &fl4, &res))
228 goto last_resort;
229 if (res.type != RTN_UNICAST) {
230 if (res.type != RTN_LOCAL || !accept_local)
231 goto e_inval;
232 }
233 *spec_dst = FIB_RES_PREFSRC(net, res);
234 fib_combine_itag(itag, &res);
235 dev_match = false;
236
237#ifdef CONFIG_IP_ROUTE_MULTIPATH
238 for (ret = 0; ret < res.fi->fib_nhs; ret++) {
239 struct fib_nh *nh = &res.fi->fib_nh[ret];
240
241 if (nh->nh_dev == dev) {
242 dev_match = true;
243 break;
244 }
245 }
246#else
247 if (FIB_RES_DEV(res) == dev)
248 dev_match = true;
249#endif
250 if (dev_match) {
251 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
252 return ret;
253 }
254 if (no_addr)
255 goto last_resort;
256 if (rpf == 1)
257 goto e_rpf;
258 fl4.flowi4_oif = dev->ifindex;
259
260 ret = 0;
261 if (fib_lookup(net, &fl4, &res) == 0) {
262 if (res.type == RTN_UNICAST) {
263 *spec_dst = FIB_RES_PREFSRC(net, res);
264 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
265 }
266 }
267 return ret;
268
269last_resort:
270 if (rpf)
271 goto e_rpf;
272 *spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
273 *itag = 0;
274 return 0;
275
276e_inval:
277 return -EINVAL;
278e_rpf:
279 return -EXDEV;
280}
281
282static inline __be32 sk_extract_addr(struct sockaddr *addr)
283{
284 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
285}
286
287static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
288{
289 struct nlattr *nla;
290
291 nla = (struct nlattr *) ((char *) mx + len);
292 nla->nla_type = type;
293 nla->nla_len = nla_attr_size(4);
294 *(u32 *) nla_data(nla) = value;
295
296 return len + nla_total_size(4);
297}
298
299static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
300 struct fib_config *cfg)
301{
302 __be32 addr;
303 int plen;
304
305 memset(cfg, 0, sizeof(*cfg));
306 cfg->fc_nlinfo.nl_net = net;
307
308 if (rt->rt_dst.sa_family != AF_INET)
309 return -EAFNOSUPPORT;
310
311 /*
312 * Check mask for validity:
313 * a) it must be contiguous.
314 * b) destination must have all host bits clear.
315 * c) if application forgot to set correct family (AF_INET),
316 * reject request unless it is absolutely clear i.e.
317 * both family and mask are zero.
318 */
319 plen = 32;
320 addr = sk_extract_addr(&rt->rt_dst);
321 if (!(rt->rt_flags & RTF_HOST)) {
322 __be32 mask = sk_extract_addr(&rt->rt_genmask);
323
324 if (rt->rt_genmask.sa_family != AF_INET) {
325 if (mask || rt->rt_genmask.sa_family)
326 return -EAFNOSUPPORT;
327 }
328
329 if (bad_mask(mask, addr))
330 return -EINVAL;
331
332 plen = inet_mask_len(mask);
333 }
334
335 cfg->fc_dst_len = plen;
336 cfg->fc_dst = addr;
337
338 if (cmd != SIOCDELRT) {
339 cfg->fc_nlflags = NLM_F_CREATE;
340 cfg->fc_protocol = RTPROT_BOOT;
341 }
342
343 if (rt->rt_metric)
344 cfg->fc_priority = rt->rt_metric - 1;
345
346 if (rt->rt_flags & RTF_REJECT) {
347 cfg->fc_scope = RT_SCOPE_HOST;
348 cfg->fc_type = RTN_UNREACHABLE;
349 return 0;
350 }
351
352 cfg->fc_scope = RT_SCOPE_NOWHERE;
353 cfg->fc_type = RTN_UNICAST;
354
355 if (rt->rt_dev) {
356 char *colon;
357 struct net_device *dev;
358 char devname[IFNAMSIZ];
359
360 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
361 return -EFAULT;
362
363 devname[IFNAMSIZ-1] = 0;
364 colon = strchr(devname, ':');
365 if (colon)
366 *colon = 0;
367 dev = __dev_get_by_name(net, devname);
368 if (!dev)
369 return -ENODEV;
370 cfg->fc_oif = dev->ifindex;
371 if (colon) {
372 struct in_ifaddr *ifa;
373 struct in_device *in_dev = __in_dev_get_rtnl(dev);
374 if (!in_dev)
375 return -ENODEV;
376 *colon = ':';
377 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
378 if (strcmp(ifa->ifa_label, devname) == 0)
379 break;
380 if (ifa == NULL)
381 return -ENODEV;
382 cfg->fc_prefsrc = ifa->ifa_local;
383 }
384 }
385
386 addr = sk_extract_addr(&rt->rt_gateway);
387 if (rt->rt_gateway.sa_family == AF_INET && addr) {
388 cfg->fc_gw = addr;
389 if (rt->rt_flags & RTF_GATEWAY &&
390 inet_addr_type(net, addr) == RTN_UNICAST)
391 cfg->fc_scope = RT_SCOPE_UNIVERSE;
392 }
393
394 if (cmd == SIOCDELRT)
395 return 0;
396
397 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
398 return -EINVAL;
399
400 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
401 cfg->fc_scope = RT_SCOPE_LINK;
402
403 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
404 struct nlattr *mx;
405 int len = 0;
406
407 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
408 if (mx == NULL)
409 return -ENOMEM;
410
411 if (rt->rt_flags & RTF_MTU)
412 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
413
414 if (rt->rt_flags & RTF_WINDOW)
415 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
416
417 if (rt->rt_flags & RTF_IRTT)
418 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
419
420 cfg->fc_mx = mx;
421 cfg->fc_mx_len = len;
422 }
423
424 return 0;
425}
426
427/*
428 * Handle IP routing ioctl calls.
429 * These are used to manipulate the routing tables
430 */
431int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
432{
433 struct fib_config cfg;
434 struct rtentry rt;
435 int err;
436
437 switch (cmd) {
438 case SIOCADDRT: /* Add a route */
439 case SIOCDELRT: /* Delete a route */
440 if (!capable(CAP_NET_ADMIN))
441 return -EPERM;
442
443 if (copy_from_user(&rt, arg, sizeof(rt)))
444 return -EFAULT;
445
446 rtnl_lock();
447 err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
448 if (err == 0) {
449 struct fib_table *tb;
450
451 if (cmd == SIOCDELRT) {
452 tb = fib_get_table(net, cfg.fc_table);
453 if (tb)
454 err = fib_table_delete(tb, &cfg);
455 else
456 err = -ESRCH;
457 } else {
458 tb = fib_new_table(net, cfg.fc_table);
459 if (tb)
460 err = fib_table_insert(tb, &cfg);
461 else
462 err = -ENOBUFS;
463 }
464
465 /* allocated by rtentry_to_fib_config() */
466 kfree(cfg.fc_mx);
467 }
468 rtnl_unlock();
469 return err;
470 }
471 return -EINVAL;
472}
473
474const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
475 [RTA_DST] = { .type = NLA_U32 },
476 [RTA_SRC] = { .type = NLA_U32 },
477 [RTA_IIF] = { .type = NLA_U32 },
478 [RTA_OIF] = { .type = NLA_U32 },
479 [RTA_GATEWAY] = { .type = NLA_U32 },
480 [RTA_PRIORITY] = { .type = NLA_U32 },
481 [RTA_PREFSRC] = { .type = NLA_U32 },
482 [RTA_METRICS] = { .type = NLA_NESTED },
483 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
484 [RTA_FLOW] = { .type = NLA_U32 },
485};
486
487static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
488 struct nlmsghdr *nlh, struct fib_config *cfg)
489{
490 struct nlattr *attr;
491 int err, remaining;
492 struct rtmsg *rtm;
493
494 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
495 if (err < 0)
496 goto errout;
497
498 memset(cfg, 0, sizeof(*cfg));
499
500 rtm = nlmsg_data(nlh);
501 cfg->fc_dst_len = rtm->rtm_dst_len;
502 cfg->fc_tos = rtm->rtm_tos;
503 cfg->fc_table = rtm->rtm_table;
504 cfg->fc_protocol = rtm->rtm_protocol;
505 cfg->fc_scope = rtm->rtm_scope;
506 cfg->fc_type = rtm->rtm_type;
507 cfg->fc_flags = rtm->rtm_flags;
508 cfg->fc_nlflags = nlh->nlmsg_flags;
509
510 cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid;
511 cfg->fc_nlinfo.nlh = nlh;
512 cfg->fc_nlinfo.nl_net = net;
513
514 if (cfg->fc_type > RTN_MAX) {
515 err = -EINVAL;
516 goto errout;
517 }
518
519 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
520 switch (nla_type(attr)) {
521 case RTA_DST:
522 cfg->fc_dst = nla_get_be32(attr);
523 break;
524 case RTA_OIF:
525 cfg->fc_oif = nla_get_u32(attr);
526 break;
527 case RTA_GATEWAY:
528 cfg->fc_gw = nla_get_be32(attr);
529 break;
530 case RTA_PRIORITY:
531 cfg->fc_priority = nla_get_u32(attr);
532 break;
533 case RTA_PREFSRC:
534 cfg->fc_prefsrc = nla_get_be32(attr);
535 break;
536 case RTA_METRICS:
537 cfg->fc_mx = nla_data(attr);
538 cfg->fc_mx_len = nla_len(attr);
539 break;
540 case RTA_MULTIPATH:
541 cfg->fc_mp = nla_data(attr);
542 cfg->fc_mp_len = nla_len(attr);
543 break;
544 case RTA_FLOW:
545 cfg->fc_flow = nla_get_u32(attr);
546 break;
547 case RTA_TABLE:
548 cfg->fc_table = nla_get_u32(attr);
549 break;
550 }
551 }
552
553 return 0;
554errout:
555 return err;
556}
557
558static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
559{
560 struct net *net = sock_net(skb->sk);
561 struct fib_config cfg;
562 struct fib_table *tb;
563 int err;
564
565 err = rtm_to_fib_config(net, skb, nlh, &cfg);
566 if (err < 0)
567 goto errout;
568
569 tb = fib_get_table(net, cfg.fc_table);
570 if (tb == NULL) {
571 err = -ESRCH;
572 goto errout;
573 }
574
575 err = fib_table_delete(tb, &cfg);
576errout:
577 return err;
578}
579
580static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
581{
582 struct net *net = sock_net(skb->sk);
583 struct fib_config cfg;
584 struct fib_table *tb;
585 int err;
586
587 err = rtm_to_fib_config(net, skb, nlh, &cfg);
588 if (err < 0)
589 goto errout;
590
591 tb = fib_new_table(net, cfg.fc_table);
592 if (tb == NULL) {
593 err = -ENOBUFS;
594 goto errout;
595 }
596
597 err = fib_table_insert(tb, &cfg);
598errout:
599 return err;
600}
601
602static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
603{
604 struct net *net = sock_net(skb->sk);
605 unsigned int h, s_h;
606 unsigned int e = 0, s_e;
607 struct fib_table *tb;
608 struct hlist_node *node;
609 struct hlist_head *head;
610 int dumped = 0;
611
612 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
613 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
614 return ip_rt_dump(skb, cb);
615
616 s_h = cb->args[0];
617 s_e = cb->args[1];
618
619 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
620 e = 0;
621 head = &net->ipv4.fib_table_hash[h];
622 hlist_for_each_entry(tb, node, head, tb_hlist) {
623 if (e < s_e)
624 goto next;
625 if (dumped)
626 memset(&cb->args[2], 0, sizeof(cb->args) -
627 2 * sizeof(cb->args[0]));
628 if (fib_table_dump(tb, skb, cb) < 0)
629 goto out;
630 dumped = 1;
631next:
632 e++;
633 }
634 }
635out:
636 cb->args[1] = e;
637 cb->args[0] = h;
638
639 return skb->len;
640}
641
642/* Prepare and feed intra-kernel routing request.
643 * Really, it should be netlink message, but :-( netlink
644 * can be not configured, so that we feed it directly
645 * to fib engine. It is legal, because all events occur
646 * only when netlink is already locked.
647 */
648static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
649{
650 struct net *net = dev_net(ifa->ifa_dev->dev);
651 struct fib_table *tb;
652 struct fib_config cfg = {
653 .fc_protocol = RTPROT_KERNEL,
654 .fc_type = type,
655 .fc_dst = dst,
656 .fc_dst_len = dst_len,
657 .fc_prefsrc = ifa->ifa_local,
658 .fc_oif = ifa->ifa_dev->dev->ifindex,
659 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
660 .fc_nlinfo = {
661 .nl_net = net,
662 },
663 };
664
665 if (type == RTN_UNICAST)
666 tb = fib_new_table(net, RT_TABLE_MAIN);
667 else
668 tb = fib_new_table(net, RT_TABLE_LOCAL);
669
670 if (tb == NULL)
671 return;
672
673 cfg.fc_table = tb->tb_id;
674
675 if (type != RTN_LOCAL)
676 cfg.fc_scope = RT_SCOPE_LINK;
677 else
678 cfg.fc_scope = RT_SCOPE_HOST;
679
680 if (cmd == RTM_NEWROUTE)
681 fib_table_insert(tb, &cfg);
682 else
683 fib_table_delete(tb, &cfg);
684}
685
686void fib_add_ifaddr(struct in_ifaddr *ifa)
687{
688 struct in_device *in_dev = ifa->ifa_dev;
689 struct net_device *dev = in_dev->dev;
690 struct in_ifaddr *prim = ifa;
691 __be32 mask = ifa->ifa_mask;
692 __be32 addr = ifa->ifa_local;
693 __be32 prefix = ifa->ifa_address & mask;
694
695 if (ifa->ifa_flags & IFA_F_SECONDARY) {
696 prim = inet_ifa_byprefix(in_dev, prefix, mask);
697 if (prim == NULL) {
698 printk(KERN_WARNING "fib_add_ifaddr: bug: prim == NULL\n");
699 return;
700 }
701 }
702
703 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
704
705 if (!(dev->flags & IFF_UP))
706 return;
707
708 /* Add broadcast address, if it is explicitly assigned. */
709 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
710 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
711
712 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
713 (prefix != addr || ifa->ifa_prefixlen < 32)) {
714 fib_magic(RTM_NEWROUTE,
715 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
716 prefix, ifa->ifa_prefixlen, prim);
717
718 /* Add network specific broadcasts, when it takes a sense */
719 if (ifa->ifa_prefixlen < 31) {
720 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
721 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
722 32, prim);
723 }
724 }
725}
726
727/* Delete primary or secondary address.
728 * Optionally, on secondary address promotion consider the addresses
729 * from subnet iprim as deleted, even if they are in device list.
730 * In this case the secondary ifa can be in device list.
731 */
732void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
733{
734 struct in_device *in_dev = ifa->ifa_dev;
735 struct net_device *dev = in_dev->dev;
736 struct in_ifaddr *ifa1;
737 struct in_ifaddr *prim = ifa, *prim1 = NULL;
738 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
739 __be32 any = ifa->ifa_address & ifa->ifa_mask;
740#define LOCAL_OK 1
741#define BRD_OK 2
742#define BRD0_OK 4
743#define BRD1_OK 8
744 unsigned ok = 0;
745 int subnet = 0; /* Primary network */
746 int gone = 1; /* Address is missing */
747 int same_prefsrc = 0; /* Another primary with same IP */
748
749 if (ifa->ifa_flags & IFA_F_SECONDARY) {
750 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
751 if (prim == NULL) {
752 printk(KERN_WARNING "fib_del_ifaddr: bug: prim == NULL\n");
753 return;
754 }
755 if (iprim && iprim != prim) {
756 printk(KERN_WARNING "fib_del_ifaddr: bug: iprim != prim\n");
757 return;
758 }
759 } else if (!ipv4_is_zeronet(any) &&
760 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
761 fib_magic(RTM_DELROUTE,
762 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
763 any, ifa->ifa_prefixlen, prim);
764 subnet = 1;
765 }
766
767 /* Deletion is more complicated than add.
768 * We should take care of not to delete too much :-)
769 *
770 * Scan address list to be sure that addresses are really gone.
771 */
772
773 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
774 if (ifa1 == ifa) {
775 /* promotion, keep the IP */
776 gone = 0;
777 continue;
778 }
779 /* Ignore IFAs from our subnet */
780 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
781 inet_ifa_match(ifa1->ifa_address, iprim))
782 continue;
783
784 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
785 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
786 /* Another address from our subnet? */
787 if (ifa1->ifa_mask == prim->ifa_mask &&
788 inet_ifa_match(ifa1->ifa_address, prim))
789 prim1 = prim;
790 else {
791 /* We reached the secondaries, so
792 * same_prefsrc should be determined.
793 */
794 if (!same_prefsrc)
795 continue;
796 /* Search new prim1 if ifa1 is not
797 * using the current prim1
798 */
799 if (!prim1 ||
800 ifa1->ifa_mask != prim1->ifa_mask ||
801 !inet_ifa_match(ifa1->ifa_address, prim1))
802 prim1 = inet_ifa_byprefix(in_dev,
803 ifa1->ifa_address,
804 ifa1->ifa_mask);
805 if (!prim1)
806 continue;
807 if (prim1->ifa_local != prim->ifa_local)
808 continue;
809 }
810 } else {
811 if (prim->ifa_local != ifa1->ifa_local)
812 continue;
813 prim1 = ifa1;
814 if (prim != prim1)
815 same_prefsrc = 1;
816 }
817 if (ifa->ifa_local == ifa1->ifa_local)
818 ok |= LOCAL_OK;
819 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
820 ok |= BRD_OK;
821 if (brd == ifa1->ifa_broadcast)
822 ok |= BRD1_OK;
823 if (any == ifa1->ifa_broadcast)
824 ok |= BRD0_OK;
825 /* primary has network specific broadcasts */
826 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
827 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
828 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
829
830 if (!ipv4_is_zeronet(any1)) {
831 if (ifa->ifa_broadcast == brd1 ||
832 ifa->ifa_broadcast == any1)
833 ok |= BRD_OK;
834 if (brd == brd1 || brd == any1)
835 ok |= BRD1_OK;
836 if (any == brd1 || any == any1)
837 ok |= BRD0_OK;
838 }
839 }
840 }
841
842 if (!(ok & BRD_OK))
843 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
844 if (subnet && ifa->ifa_prefixlen < 31) {
845 if (!(ok & BRD1_OK))
846 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
847 if (!(ok & BRD0_OK))
848 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
849 }
850 if (!(ok & LOCAL_OK)) {
851 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
852
853 /* Check, that this local address finally disappeared. */
854 if (gone &&
855 inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) {
856 /* And the last, but not the least thing.
857 * We must flush stray FIB entries.
858 *
859 * First of all, we scan fib_info list searching
860 * for stray nexthop entries, then ignite fib_flush.
861 */
862 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
863 fib_flush(dev_net(dev));
864 }
865 }
866#undef LOCAL_OK
867#undef BRD_OK
868#undef BRD0_OK
869#undef BRD1_OK
870}
871
872static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb)
873{
874
875 struct fib_result res;
876 struct flowi4 fl4 = {
877 .flowi4_mark = frn->fl_mark,
878 .daddr = frn->fl_addr,
879 .flowi4_tos = frn->fl_tos,
880 .flowi4_scope = frn->fl_scope,
881 };
882
883#ifdef CONFIG_IP_MULTIPLE_TABLES
884 res.r = NULL;
885#endif
886
887 frn->err = -ENOENT;
888 if (tb) {
889 local_bh_disable();
890
891 frn->tb_id = tb->tb_id;
892 rcu_read_lock();
893 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
894
895 if (!frn->err) {
896 frn->prefixlen = res.prefixlen;
897 frn->nh_sel = res.nh_sel;
898 frn->type = res.type;
899 frn->scope = res.scope;
900 }
901 rcu_read_unlock();
902 local_bh_enable();
903 }
904}
905
906static void nl_fib_input(struct sk_buff *skb)
907{
908 struct net *net;
909 struct fib_result_nl *frn;
910 struct nlmsghdr *nlh;
911 struct fib_table *tb;
912 u32 pid;
913
914 net = sock_net(skb->sk);
915 nlh = nlmsg_hdr(skb);
916 if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len ||
917 nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn)))
918 return;
919
920 skb = skb_clone(skb, GFP_KERNEL);
921 if (skb == NULL)
922 return;
923 nlh = nlmsg_hdr(skb);
924
925 frn = (struct fib_result_nl *) NLMSG_DATA(nlh);
926 tb = fib_get_table(net, frn->tb_id_in);
927
928 nl_fib_lookup(frn, tb);
929
930 pid = NETLINK_CB(skb).pid; /* pid of sending process */
931 NETLINK_CB(skb).pid = 0; /* from kernel */
932 NETLINK_CB(skb).dst_group = 0; /* unicast */
933 netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT);
934}
935
936static int __net_init nl_fib_lookup_init(struct net *net)
937{
938 struct sock *sk;
939 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0,
940 nl_fib_input, NULL, THIS_MODULE);
941 if (sk == NULL)
942 return -EAFNOSUPPORT;
943 net->ipv4.fibnl = sk;
944 return 0;
945}
946
947static void nl_fib_lookup_exit(struct net *net)
948{
949 netlink_kernel_release(net->ipv4.fibnl);
950 net->ipv4.fibnl = NULL;
951}
952
953static void fib_disable_ip(struct net_device *dev, int force, int delay)
954{
955 if (fib_sync_down_dev(dev, force))
956 fib_flush(dev_net(dev));
957 rt_cache_flush(dev_net(dev), delay);
958 arp_ifdown(dev);
959}
960
961static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
962{
963 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
964 struct net_device *dev = ifa->ifa_dev->dev;
965 struct net *net = dev_net(dev);
966
967 switch (event) {
968 case NETDEV_UP:
969 fib_add_ifaddr(ifa);
970#ifdef CONFIG_IP_ROUTE_MULTIPATH
971 fib_sync_up(dev);
972#endif
973 atomic_inc(&net->ipv4.dev_addr_genid);
974 rt_cache_flush(dev_net(dev), -1);
975 break;
976 case NETDEV_DOWN:
977 fib_del_ifaddr(ifa, NULL);
978 atomic_inc(&net->ipv4.dev_addr_genid);
979 if (ifa->ifa_dev->ifa_list == NULL) {
980 /* Last address was deleted from this interface.
981 * Disable IP.
982 */
983 fib_disable_ip(dev, 1, 0);
984 } else {
985 rt_cache_flush(dev_net(dev), -1);
986 }
987 break;
988 }
989 return NOTIFY_DONE;
990}
991
992static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
993{
994 struct net_device *dev = ptr;
995 struct in_device *in_dev = __in_dev_get_rtnl(dev);
996 struct net *net = dev_net(dev);
997
998 if (event == NETDEV_UNREGISTER) {
999 fib_disable_ip(dev, 2, -1);
1000 return NOTIFY_DONE;
1001 }
1002
1003 if (!in_dev)
1004 return NOTIFY_DONE;
1005
1006 switch (event) {
1007 case NETDEV_UP:
1008 for_ifa(in_dev) {
1009 fib_add_ifaddr(ifa);
1010 } endfor_ifa(in_dev);
1011#ifdef CONFIG_IP_ROUTE_MULTIPATH
1012 fib_sync_up(dev);
1013#endif
1014 atomic_inc(&net->ipv4.dev_addr_genid);
1015 rt_cache_flush(dev_net(dev), -1);
1016 break;
1017 case NETDEV_DOWN:
1018 fib_disable_ip(dev, 0, 0);
1019 break;
1020 case NETDEV_CHANGEMTU:
1021 case NETDEV_CHANGE:
1022 rt_cache_flush(dev_net(dev), 0);
1023 break;
1024 case NETDEV_UNREGISTER_BATCH:
1025 /* The batch unregister is only called on the first
1026 * device in the list of devices being unregistered.
1027 * Therefore we should not pass dev_net(dev) in here.
1028 */
1029 rt_cache_flush_batch(NULL);
1030 break;
1031 }
1032 return NOTIFY_DONE;
1033}
1034
1035static struct notifier_block fib_inetaddr_notifier = {
1036 .notifier_call = fib_inetaddr_event,
1037};
1038
1039static struct notifier_block fib_netdev_notifier = {
1040 .notifier_call = fib_netdev_event,
1041};
1042
1043static int __net_init ip_fib_net_init(struct net *net)
1044{
1045 int err;
1046 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1047
1048 /* Avoid false sharing : Use at least a full cache line */
1049 size = max_t(size_t, size, L1_CACHE_BYTES);
1050
1051 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1052 if (net->ipv4.fib_table_hash == NULL)
1053 return -ENOMEM;
1054
1055 err = fib4_rules_init(net);
1056 if (err < 0)
1057 goto fail;
1058 return 0;
1059
1060fail:
1061 kfree(net->ipv4.fib_table_hash);
1062 return err;
1063}
1064
1065static void ip_fib_net_exit(struct net *net)
1066{
1067 unsigned int i;
1068
1069#ifdef CONFIG_IP_MULTIPLE_TABLES
1070 fib4_rules_exit(net);
1071#endif
1072
1073 rtnl_lock();
1074 for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1075 struct fib_table *tb;
1076 struct hlist_head *head;
1077 struct hlist_node *node, *tmp;
1078
1079 head = &net->ipv4.fib_table_hash[i];
1080 hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) {
1081 hlist_del(node);
1082 fib_table_flush(tb);
1083 fib_free_table(tb);
1084 }
1085 }
1086 rtnl_unlock();
1087 kfree(net->ipv4.fib_table_hash);
1088}
1089
1090static int __net_init fib_net_init(struct net *net)
1091{
1092 int error;
1093
1094 error = ip_fib_net_init(net);
1095 if (error < 0)
1096 goto out;
1097 error = nl_fib_lookup_init(net);
1098 if (error < 0)
1099 goto out_nlfl;
1100 error = fib_proc_init(net);
1101 if (error < 0)
1102 goto out_proc;
1103out:
1104 return error;
1105
1106out_proc:
1107 nl_fib_lookup_exit(net);
1108out_nlfl:
1109 ip_fib_net_exit(net);
1110 goto out;
1111}
1112
1113static void __net_exit fib_net_exit(struct net *net)
1114{
1115 fib_proc_exit(net);
1116 nl_fib_lookup_exit(net);
1117 ip_fib_net_exit(net);
1118}
1119
1120static struct pernet_operations fib_net_ops = {
1121 .init = fib_net_init,
1122 .exit = fib_net_exit,
1123};
1124
1125void __init ip_fib_init(void)
1126{
1127 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1128 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1129 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1130
1131 register_pernet_subsys(&fib_net_ops);
1132 register_netdevice_notifier(&fib_netdev_notifier);
1133 register_inetaddr_notifier(&fib_inetaddr_notifier);
1134
1135 fib_trie_init();
1136}