1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * IPv4 Forwarding Information Base: FIB frontend.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 */
11
12#include <linux/module.h>
13#include <linux/uaccess.h>
14#include <linux/bitops.h>
15#include <linux/capability.h>
16#include <linux/types.h>
17#include <linux/kernel.h>
18#include <linux/mm.h>
19#include <linux/string.h>
20#include <linux/socket.h>
21#include <linux/sockios.h>
22#include <linux/errno.h>
23#include <linux/in.h>
24#include <linux/inet.h>
25#include <linux/inetdevice.h>
26#include <linux/netdevice.h>
27#include <linux/if_addr.h>
28#include <linux/if_arp.h>
29#include <linux/skbuff.h>
30#include <linux/cache.h>
31#include <linux/init.h>
32#include <linux/list.h>
33#include <linux/slab.h>
34
35#include <net/flow.h>
36#include <net/inet_dscp.h>
37#include <net/ip.h>
38#include <net/protocol.h>
39#include <net/route.h>
40#include <net/tcp.h>
41#include <net/sock.h>
42#include <net/arp.h>
43#include <net/ip_fib.h>
44#include <net/nexthop.h>
45#include <net/rtnetlink.h>
46#include <net/xfrm.h>
47#include <net/l3mdev.h>
48#include <net/lwtunnel.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 && !net->ipv4.fib_has_custom_rules)
89 alias = fib_new_table(net, id: 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_MAIN:
97 rcu_assign_pointer(net->ipv4.fib_main, tb);
98 break;
99 case RT_TABLE_DEFAULT:
100 rcu_assign_pointer(net->ipv4.fib_default, tb);
101 break;
102 default:
103 break;
104 }
105
106 h = id & (FIB_TABLE_HASHSZ - 1);
107 hlist_add_head_rcu(n: &tb->tb_hlist, h: &net->ipv4.fib_table_hash[h]);
108 return tb;
109}
110EXPORT_SYMBOL_GPL(fib_new_table);
111
112/* caller must hold either rtnl or rcu read lock */
113struct fib_table *fib_get_table(struct net *net, u32 id)
114{
115 struct fib_table *tb;
116 struct hlist_head *head;
117 unsigned int h;
118
119 if (id == 0)
120 id = RT_TABLE_MAIN;
121 h = id & (FIB_TABLE_HASHSZ - 1);
122
123 head = &net->ipv4.fib_table_hash[h];
124 hlist_for_each_entry_rcu(tb, head, tb_hlist,
125 lockdep_rtnl_is_held()) {
126 if (tb->tb_id == id)
127 return tb;
128 }
129 return NULL;
130}
131#endif /* CONFIG_IP_MULTIPLE_TABLES */
132
133static void fib_replace_table(struct net *net, struct fib_table *old,
134 struct fib_table *new)
135{
136#ifdef CONFIG_IP_MULTIPLE_TABLES
137 switch (new->tb_id) {
138 case RT_TABLE_MAIN:
139 rcu_assign_pointer(net->ipv4.fib_main, new);
140 break;
141 case RT_TABLE_DEFAULT:
142 rcu_assign_pointer(net->ipv4.fib_default, new);
143 break;
144 default:
145 break;
146 }
147
148#endif
149 /* replace the old table in the hlist */
150 hlist_replace_rcu(old: &old->tb_hlist, new: &new->tb_hlist);
151}
152
153int fib_unmerge(struct net *net)
154{
155 struct fib_table *old, *new, *main_table;
156
157 /* attempt to fetch local table if it has been allocated */
158 old = fib_get_table(net, id: RT_TABLE_LOCAL);
159 if (!old)
160 return 0;
161
162 new = fib_trie_unmerge(main_tb: old);
163 if (!new)
164 return -ENOMEM;
165
166 /* table is already unmerged */
167 if (new == old)
168 return 0;
169
170 /* replace merged table with clean table */
171 fib_replace_table(net, old, new);
172 fib_free_table(tb: old);
173
174 /* attempt to fetch main table if it has been allocated */
175 main_table = fib_get_table(net, id: RT_TABLE_MAIN);
176 if (!main_table)
177 return 0;
178
179 /* flush local entries from main table */
180 fib_table_flush_external(table: main_table);
181
182 return 0;
183}
184
185void fib_flush(struct net *net)
186{
187 int flushed = 0;
188 unsigned int h;
189
190 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
191 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
192 struct hlist_node *tmp;
193 struct fib_table *tb;
194
195 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
196 flushed += fib_table_flush(net, table: tb, flush_all: false);
197 }
198
199 if (flushed)
200 rt_cache_flush(net);
201}
202
203/*
204 * Find address type as if only "dev" was present in the system. If
205 * on_dev is NULL then all interfaces are taken into consideration.
206 */
207static inline unsigned int __inet_dev_addr_type(struct net *net,
208 const struct net_device *dev,
209 __be32 addr, u32 tb_id)
210{
211 struct flowi4 fl4 = { .daddr = addr };
212 struct fib_result res;
213 unsigned int ret = RTN_BROADCAST;
214 struct fib_table *table;
215
216 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
217 return RTN_BROADCAST;
218 if (ipv4_is_multicast(addr))
219 return RTN_MULTICAST;
220
221 rcu_read_lock();
222
223 table = fib_get_table(net, id: tb_id);
224 if (table) {
225 ret = RTN_UNICAST;
226 if (!fib_table_lookup(tb: table, flp: &fl4, res: &res, FIB_LOOKUP_NOREF)) {
227 struct fib_nh_common *nhc = fib_info_nhc(fi: res.fi, nhsel: 0);
228
229 if (!dev || dev == nhc->nhc_dev)
230 ret = res.type;
231 }
232 }
233
234 rcu_read_unlock();
235 return ret;
236}
237
238unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
239{
240 return __inet_dev_addr_type(net, NULL, addr, tb_id);
241}
242EXPORT_SYMBOL(inet_addr_type_table);
243
244unsigned int inet_addr_type(struct net *net, __be32 addr)
245{
246 return __inet_dev_addr_type(net, NULL, addr, tb_id: RT_TABLE_LOCAL);
247}
248EXPORT_SYMBOL(inet_addr_type);
249
250unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
251 __be32 addr)
252{
253 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
254
255 return __inet_dev_addr_type(net, dev, addr, tb_id: rt_table);
256}
257EXPORT_SYMBOL(inet_dev_addr_type);
258
259/* inet_addr_type with dev == NULL but using the table from a dev
260 * if one is associated
261 */
262unsigned int inet_addr_type_dev_table(struct net *net,
263 const struct net_device *dev,
264 __be32 addr)
265{
266 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
267
268 return __inet_dev_addr_type(net, NULL, addr, tb_id: rt_table);
269}
270EXPORT_SYMBOL(inet_addr_type_dev_table);
271
272__be32 fib_compute_spec_dst(struct sk_buff *skb)
273{
274 struct net_device *dev = skb->dev;
275 struct in_device *in_dev;
276 struct fib_result res;
277 struct rtable *rt;
278 struct net *net;
279 int scope;
280
281 rt = skb_rtable(skb);
282 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
283 RTCF_LOCAL)
284 return ip_hdr(skb)->daddr;
285
286 in_dev = __in_dev_get_rcu(dev);
287
288 net = dev_net(dev);
289
290 scope = RT_SCOPE_UNIVERSE;
291 if (!ipv4_is_zeronet(addr: ip_hdr(skb)->saddr)) {
292 bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev);
293 struct flowi4 fl4 = {
294 .flowi4_iif = LOOPBACK_IFINDEX,
295 .flowi4_l3mdev = l3mdev_master_ifindex_rcu(dev),
296 .daddr = ip_hdr(skb)->saddr,
297 .flowi4_dscp = ip4h_dscp(ip4h: ip_hdr(skb)),
298 .flowi4_scope = scope,
299 .flowi4_mark = vmark ? skb->mark : 0,
300 };
301 if (!fib_lookup(net, flp: &fl4, res: &res, flags: 0))
302 return fib_result_prefsrc(net, res: &res);
303 } else {
304 scope = RT_SCOPE_LINK;
305 }
306
307 return inet_select_addr(dev, dst: ip_hdr(skb)->saddr, scope);
308}
309
310bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev)
311{
312 bool dev_match = false;
313#ifdef CONFIG_IP_ROUTE_MULTIPATH
314 if (unlikely(fi->nh)) {
315 dev_match = nexthop_uses_dev(nh: fi->nh, dev);
316 } else {
317 int ret;
318
319 for (ret = 0; ret < fib_info_num_path(fi); ret++) {
320 const struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel: ret);
321
322 if (nhc_l3mdev_matches_dev(nhc, dev)) {
323 dev_match = true;
324 break;
325 }
326 }
327 }
328#else
329 if (fib_info_nhc(fi, 0)->nhc_dev == dev)
330 dev_match = true;
331#endif
332
333 return dev_match;
334}
335EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev);
336
337/* Given (packet source, input interface) and optional (dst, oif, tos):
338 * - (main) check, that source is valid i.e. not broadcast or our local
339 * address.
340 * - figure out what "logical" interface this packet arrived
341 * and calculate "specific destination" address.
342 * - check, that packet arrived from expected physical interface.
343 * called with rcu_read_lock()
344 */
345static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
346 dscp_t dscp, int oif, struct net_device *dev,
347 int rpf, struct in_device *idev, u32 *itag)
348{
349 struct net *net = dev_net(dev);
350 enum skb_drop_reason reason;
351 struct flow_keys flkeys;
352 int ret, no_addr;
353 struct fib_result res;
354 struct flowi4 fl4;
355 bool dev_match;
356
357 fl4.flowi4_oif = 0;
358 fl4.flowi4_l3mdev = l3mdev_master_ifindex_rcu(dev);
359 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
360 fl4.daddr = src;
361 fl4.saddr = dst;
362 fl4.flowi4_dscp = dscp;
363 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
364 fl4.flowi4_tun_key.tun_id = 0;
365 fl4.flowi4_flags = 0;
366 fl4.flowi4_uid = sock_net_uid(net, NULL);
367 fl4.flowi4_multipath_hash = 0;
368
369 no_addr = idev->ifa_list == NULL;
370
371 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
372 if (!fib4_rules_early_flow_dissect(net, skb, fl4: &fl4, flkeys: &flkeys)) {
373 fl4.flowi4_proto = 0;
374 fl4.fl4_sport = 0;
375 fl4.fl4_dport = 0;
376 } else {
377 swap(fl4.fl4_sport, fl4.fl4_dport);
378 }
379
380 if (fib_lookup(net, flp: &fl4, res: &res, flags: 0))
381 goto last_resort;
382 if (res.type != RTN_UNICAST) {
383 if (res.type != RTN_LOCAL) {
384 reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
385 goto e_inval;
386 } else if (!IN_DEV_ACCEPT_LOCAL(idev)) {
387 reason = SKB_DROP_REASON_IP_LOCAL_SOURCE;
388 goto e_inval;
389 }
390 }
391 fib_combine_itag(itag, res: &res);
392
393 dev_match = fib_info_nh_uses_dev(res.fi, dev);
394 /* This is not common, loopback packets retain skb_dst so normally they
395 * would not even hit this slow path.
396 */
397 dev_match = dev_match || (res.type == RTN_LOCAL &&
398 dev == net->loopback_dev);
399 if (dev_match) {
400 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
401 return ret;
402 }
403 if (no_addr)
404 goto last_resort;
405 if (rpf == 1)
406 goto e_rpf;
407 fl4.flowi4_oif = dev->ifindex;
408
409 ret = 0;
410 if (fib_lookup(net, flp: &fl4, res: &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
411 if (res.type == RTN_UNICAST)
412 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
413 }
414 return ret;
415
416last_resort:
417 if (rpf)
418 goto e_rpf;
419 *itag = 0;
420 return 0;
421
422e_inval:
423 return -reason;
424e_rpf:
425 return -SKB_DROP_REASON_IP_RPFILTER;
426}
427
428/* Ignore rp_filter for packets protected by IPsec. */
429int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
430 dscp_t dscp, int oif, struct net_device *dev,
431 struct in_device *idev, u32 *itag)
432{
433 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
434 struct net *net = dev_net(dev);
435
436 if (!r && !fib_num_tclassid_users(net) &&
437 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
438 if (IN_DEV_ACCEPT_LOCAL(idev))
439 goto ok;
440 /* with custom local routes in place, checking local addresses
441 * only will be too optimistic, with custom rules, checking
442 * local addresses only can be too strict, e.g. due to vrf
443 */
444 if (net->ipv4.fib_has_custom_local_routes ||
445 fib4_has_custom_rules(net))
446 goto full_check;
447 /* Within the same container, it is regarded as a martian source,
448 * and the same host but different containers are not.
449 */
450 if (inet_lookup_ifaddr_rcu(net, addr: src))
451 return -SKB_DROP_REASON_IP_LOCAL_SOURCE;
452
453ok:
454 *itag = 0;
455 return 0;
456 }
457
458full_check:
459 return __fib_validate_source(skb, src, dst, dscp, oif, dev, rpf: r, idev,
460 itag);
461}
462
463static inline __be32 sk_extract_addr(struct sockaddr *addr)
464{
465 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
466}
467
468static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
469{
470 struct nlattr *nla;
471
472 nla = (struct nlattr *) ((char *) mx + len);
473 nla->nla_type = type;
474 nla->nla_len = nla_attr_size(payload: 4);
475 *(u32 *) nla_data(nla) = value;
476
477 return len + nla_total_size(payload: 4);
478}
479
480static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
481 struct fib_config *cfg)
482{
483 __be32 addr;
484 int plen;
485
486 memset(s: cfg, c: 0, n: sizeof(*cfg));
487 cfg->fc_nlinfo.nl_net = net;
488
489 if (rt->rt_dst.sa_family != AF_INET)
490 return -EAFNOSUPPORT;
491
492 /*
493 * Check mask for validity:
494 * a) it must be contiguous.
495 * b) destination must have all host bits clear.
496 * c) if application forgot to set correct family (AF_INET),
497 * reject request unless it is absolutely clear i.e.
498 * both family and mask are zero.
499 */
500 plen = 32;
501 addr = sk_extract_addr(addr: &rt->rt_dst);
502 if (!(rt->rt_flags & RTF_HOST)) {
503 __be32 mask = sk_extract_addr(addr: &rt->rt_genmask);
504
505 if (rt->rt_genmask.sa_family != AF_INET) {
506 if (mask || rt->rt_genmask.sa_family)
507 return -EAFNOSUPPORT;
508 }
509
510 if (bad_mask(mask, addr))
511 return -EINVAL;
512
513 plen = inet_mask_len(mask);
514 }
515
516 cfg->fc_dst_len = plen;
517 cfg->fc_dst = addr;
518
519 if (cmd != SIOCDELRT) {
520 cfg->fc_nlflags = NLM_F_CREATE;
521 cfg->fc_protocol = RTPROT_BOOT;
522 }
523
524 if (rt->rt_metric)
525 cfg->fc_priority = rt->rt_metric - 1;
526
527 if (rt->rt_flags & RTF_REJECT) {
528 cfg->fc_scope = RT_SCOPE_HOST;
529 cfg->fc_type = RTN_UNREACHABLE;
530 return 0;
531 }
532
533 cfg->fc_scope = RT_SCOPE_NOWHERE;
534 cfg->fc_type = RTN_UNICAST;
535
536 if (rt->rt_dev) {
537 char *colon;
538 struct net_device *dev;
539 char devname[IFNAMSIZ];
540
541 if (copy_from_user(to: devname, from: rt->rt_dev, IFNAMSIZ-1))
542 return -EFAULT;
543
544 devname[IFNAMSIZ-1] = 0;
545 colon = strchr(devname, ':');
546 if (colon)
547 *colon = 0;
548 dev = __dev_get_by_name(net, name: devname);
549 if (!dev)
550 return -ENODEV;
551 cfg->fc_oif = dev->ifindex;
552 cfg->fc_table = l3mdev_fib_table(dev);
553 if (colon) {
554 const struct in_ifaddr *ifa;
555 struct in_device *in_dev;
556
557 in_dev = __in_dev_get_rtnl_net(dev);
558 if (!in_dev)
559 return -ENODEV;
560
561 *colon = ':';
562
563 in_dev_for_each_ifa_rtnl_net(net, ifa, in_dev) {
564 if (strcmp(ifa->ifa_label, devname) == 0)
565 break;
566 }
567
568 if (!ifa)
569 return -ENODEV;
570 cfg->fc_prefsrc = ifa->ifa_local;
571 }
572 }
573
574 addr = sk_extract_addr(addr: &rt->rt_gateway);
575 if (rt->rt_gateway.sa_family == AF_INET && addr) {
576 unsigned int addr_type;
577
578 cfg->fc_gw4 = addr;
579 cfg->fc_gw_family = AF_INET;
580 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
581 if (rt->rt_flags & RTF_GATEWAY &&
582 addr_type == RTN_UNICAST)
583 cfg->fc_scope = RT_SCOPE_UNIVERSE;
584 }
585
586 if (!cfg->fc_table)
587 cfg->fc_table = RT_TABLE_MAIN;
588
589 if (cmd == SIOCDELRT)
590 return 0;
591
592 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family)
593 return -EINVAL;
594
595 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
596 cfg->fc_scope = RT_SCOPE_LINK;
597
598 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
599 struct nlattr *mx;
600 int len = 0;
601
602 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL);
603 if (!mx)
604 return -ENOMEM;
605
606 if (rt->rt_flags & RTF_MTU)
607 len = put_rtax(mx, len, RTAX_ADVMSS, value: rt->rt_mtu - 40);
608
609 if (rt->rt_flags & RTF_WINDOW)
610 len = put_rtax(mx, len, RTAX_WINDOW, value: rt->rt_window);
611
612 if (rt->rt_flags & RTF_IRTT)
613 len = put_rtax(mx, len, RTAX_RTT, value: rt->rt_irtt << 3);
614
615 cfg->fc_mx = mx;
616 cfg->fc_mx_len = len;
617 }
618
619 return 0;
620}
621
622/*
623 * Handle IP routing ioctl calls.
624 * These are used to manipulate the routing tables
625 */
626int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
627{
628 struct fib_config cfg;
629 int err;
630
631 switch (cmd) {
632 case SIOCADDRT: /* Add a route */
633 case SIOCDELRT: /* Delete a route */
634 if (!ns_capable(ns: net->user_ns, CAP_NET_ADMIN))
635 return -EPERM;
636
637 rtnl_net_lock(net);
638 err = rtentry_to_fib_config(net, cmd, rt, cfg: &cfg);
639 if (err == 0) {
640 struct fib_table *tb;
641
642 if (cmd == SIOCDELRT) {
643 tb = fib_get_table(net, id: cfg.fc_table);
644 if (tb)
645 err = fib_table_delete(net, tb, &cfg,
646 NULL);
647 else
648 err = -ESRCH;
649 } else {
650 tb = fib_new_table(net, cfg.fc_table);
651 if (tb)
652 err = fib_table_insert(net, tb,
653 &cfg, NULL);
654 else
655 err = -ENOBUFS;
656 }
657
658 /* allocated by rtentry_to_fib_config() */
659 kfree(objp: cfg.fc_mx);
660 }
661 rtnl_net_unlock(net);
662 return err;
663 }
664 return -EINVAL;
665}
666
667const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
668 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 },
669 [RTA_DST] = { .type = NLA_U32 },
670 [RTA_SRC] = { .type = NLA_U32 },
671 [RTA_IIF] = { .type = NLA_U32 },
672 [RTA_OIF] = { .type = NLA_U32 },
673 [RTA_GATEWAY] = { .type = NLA_U32 },
674 [RTA_PRIORITY] = { .type = NLA_U32 },
675 [RTA_PREFSRC] = { .type = NLA_U32 },
676 [RTA_METRICS] = { .type = NLA_NESTED },
677 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
678 [RTA_FLOW] = { .type = NLA_U32 },
679 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
680 [RTA_ENCAP] = { .type = NLA_NESTED },
681 [RTA_UID] = { .type = NLA_U32 },
682 [RTA_MARK] = { .type = NLA_U32 },
683 [RTA_TABLE] = { .type = NLA_U32 },
684 [RTA_IP_PROTO] = { .type = NLA_U8 },
685 [RTA_SPORT] = { .type = NLA_U16 },
686 [RTA_DPORT] = { .type = NLA_U16 },
687 [RTA_NH_ID] = { .type = NLA_U32 },
688};
689
690int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
691 struct netlink_ext_ack *extack)
692{
693 struct rtvia *via;
694 int alen;
695
696 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
697 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA");
698 return -EINVAL;
699 }
700
701 via = nla_data(nla);
702 alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr);
703
704 switch (via->rtvia_family) {
705 case AF_INET:
706 if (alen != sizeof(__be32)) {
707 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA");
708 return -EINVAL;
709 }
710 cfg->fc_gw_family = AF_INET;
711 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr);
712 break;
713 case AF_INET6:
714#if IS_ENABLED(CONFIG_IPV6)
715 if (alen != sizeof(struct in6_addr)) {
716 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA");
717 return -EINVAL;
718 }
719 cfg->fc_gw_family = AF_INET6;
720 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr);
721#else
722 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
723 return -EINVAL;
724#endif
725 break;
726 default:
727 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA");
728 return -EINVAL;
729 }
730
731 return 0;
732}
733
734static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
735 struct nlmsghdr *nlh, struct fib_config *cfg,
736 struct netlink_ext_ack *extack)
737{
738 bool has_gw = false, has_via = false;
739 struct nlattr *attr;
740 int err, remaining;
741 struct rtmsg *rtm;
742
743 err = nlmsg_validate_deprecated(nlh, hdrlen: sizeof(*rtm), RTA_MAX,
744 policy: rtm_ipv4_policy, extack);
745 if (err < 0)
746 goto errout;
747
748 memset(s: cfg, c: 0, n: sizeof(*cfg));
749
750 rtm = nlmsg_data(nlh);
751
752 if (!inet_validate_dscp(val: rtm->rtm_tos)) {
753 NL_SET_ERR_MSG(extack,
754 "Invalid dsfield (tos): ECN bits must be 0");
755 err = -EINVAL;
756 goto errout;
757 }
758 cfg->fc_dscp = inet_dsfield_to_dscp(dsfield: rtm->rtm_tos);
759
760 cfg->fc_dst_len = rtm->rtm_dst_len;
761 cfg->fc_table = rtm->rtm_table;
762 cfg->fc_protocol = rtm->rtm_protocol;
763 cfg->fc_scope = rtm->rtm_scope;
764 cfg->fc_type = rtm->rtm_type;
765 cfg->fc_flags = rtm->rtm_flags;
766 cfg->fc_nlflags = nlh->nlmsg_flags;
767
768 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
769 cfg->fc_nlinfo.nlh = nlh;
770 cfg->fc_nlinfo.nl_net = net;
771
772 if (cfg->fc_type > RTN_MAX) {
773 NL_SET_ERR_MSG(extack, "Invalid route type");
774 err = -EINVAL;
775 goto errout;
776 }
777
778 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
779 switch (nla_type(nla: attr)) {
780 case RTA_DST:
781 cfg->fc_dst = nla_get_be32(nla: attr);
782 break;
783 case RTA_OIF:
784 cfg->fc_oif = nla_get_u32(nla: attr);
785 break;
786 case RTA_GATEWAY:
787 has_gw = true;
788 cfg->fc_gw4 = nla_get_be32(nla: attr);
789 if (cfg->fc_gw4)
790 cfg->fc_gw_family = AF_INET;
791 break;
792 case RTA_VIA:
793 has_via = true;
794 err = fib_gw_from_via(cfg, nla: attr, extack);
795 if (err)
796 goto errout;
797 break;
798 case RTA_PRIORITY:
799 cfg->fc_priority = nla_get_u32(nla: attr);
800 break;
801 case RTA_PREFSRC:
802 cfg->fc_prefsrc = nla_get_be32(nla: attr);
803 break;
804 case RTA_METRICS:
805 cfg->fc_mx = nla_data(nla: attr);
806 cfg->fc_mx_len = nla_len(nla: attr);
807 break;
808 case RTA_MULTIPATH:
809 err = lwtunnel_valid_encap_type_attr(attr: nla_data(nla: attr),
810 len: nla_len(nla: attr),
811 extack);
812 if (err < 0)
813 goto errout;
814 cfg->fc_mp = nla_data(nla: attr);
815 cfg->fc_mp_len = nla_len(nla: attr);
816 break;
817 case RTA_FLOW:
818 cfg->fc_flow = nla_get_u32(nla: attr);
819 break;
820 case RTA_TABLE:
821 cfg->fc_table = nla_get_u32(nla: attr);
822 break;
823 case RTA_ENCAP:
824 cfg->fc_encap = attr;
825 break;
826 case RTA_ENCAP_TYPE:
827 cfg->fc_encap_type = nla_get_u16(nla: attr);
828 err = lwtunnel_valid_encap_type(encap_type: cfg->fc_encap_type,
829 extack);
830 if (err < 0)
831 goto errout;
832 break;
833 case RTA_NH_ID:
834 cfg->fc_nh_id = nla_get_u32(nla: attr);
835 break;
836 }
837 }
838
839 if (cfg->fc_dst_len > 32) {
840 NL_SET_ERR_MSG(extack, "Invalid prefix length");
841 err = -EINVAL;
842 goto errout;
843 }
844
845 if (cfg->fc_dst_len < 32 && (ntohl(cfg->fc_dst) << cfg->fc_dst_len)) {
846 NL_SET_ERR_MSG(extack, "Invalid prefix for given prefix length");
847 err = -EINVAL;
848 goto errout;
849 }
850
851 if (cfg->fc_nh_id) {
852 if (cfg->fc_oif || cfg->fc_gw_family ||
853 cfg->fc_encap || cfg->fc_mp) {
854 NL_SET_ERR_MSG(extack,
855 "Nexthop specification and nexthop id are mutually exclusive");
856 err = -EINVAL;
857 goto errout;
858 }
859 }
860
861 if (has_gw && has_via) {
862 NL_SET_ERR_MSG(extack,
863 "Nexthop configuration can not contain both GATEWAY and VIA");
864 err = -EINVAL;
865 goto errout;
866 }
867
868 if (!cfg->fc_table)
869 cfg->fc_table = RT_TABLE_MAIN;
870
871 return 0;
872errout:
873 return err;
874}
875
876static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
877 struct netlink_ext_ack *extack)
878{
879 struct net *net = sock_net(sk: skb->sk);
880 struct fib_config cfg;
881 struct fib_table *tb;
882 int err;
883
884 err = rtm_to_fib_config(net, skb, nlh, cfg: &cfg, extack);
885 if (err < 0)
886 goto errout;
887
888 rtnl_net_lock(net);
889
890 if (cfg.fc_nh_id && !nexthop_find_by_id(net, id: cfg.fc_nh_id)) {
891 NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
892 err = -EINVAL;
893 goto unlock;
894 }
895
896 tb = fib_get_table(net, id: cfg.fc_table);
897 if (!tb) {
898 NL_SET_ERR_MSG(extack, "FIB table does not exist");
899 err = -ESRCH;
900 goto unlock;
901 }
902
903 err = fib_table_delete(net, tb, &cfg, extack);
904unlock:
905 rtnl_net_unlock(net);
906errout:
907 return err;
908}
909
910static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
911 struct netlink_ext_ack *extack)
912{
913 struct net *net = sock_net(sk: skb->sk);
914 struct fib_config cfg;
915 struct fib_table *tb;
916 int err;
917
918 err = rtm_to_fib_config(net, skb, nlh, cfg: &cfg, extack);
919 if (err < 0)
920 goto errout;
921
922 rtnl_net_lock(net);
923
924 tb = fib_new_table(net, cfg.fc_table);
925 if (!tb) {
926 err = -ENOBUFS;
927 goto unlock;
928 }
929
930 err = fib_table_insert(net, tb, &cfg, extack);
931 if (!err && cfg.fc_type == RTN_LOCAL)
932 net->ipv4.fib_has_custom_local_routes = true;
933
934unlock:
935 rtnl_net_unlock(net);
936errout:
937 return err;
938}
939
940int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
941 struct fib_dump_filter *filter,
942 struct netlink_callback *cb)
943{
944 struct netlink_ext_ack *extack = cb->extack;
945 struct nlattr *tb[RTA_MAX + 1];
946 struct rtmsg *rtm;
947 int err, i;
948
949 if (filter->rtnl_held)
950 ASSERT_RTNL();
951
952 rtm = nlmsg_payload(nlh, len: sizeof(*rtm));
953 if (!rtm) {
954 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request");
955 return -EINVAL;
956 }
957
958 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos ||
959 rtm->rtm_scope) {
960 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request");
961 return -EINVAL;
962 }
963
964 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) {
965 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request");
966 return -EINVAL;
967 }
968 if (rtm->rtm_flags & RTM_F_CLONED)
969 filter->dump_routes = false;
970 else
971 filter->dump_exceptions = false;
972
973 filter->flags = rtm->rtm_flags;
974 filter->protocol = rtm->rtm_protocol;
975 filter->rt_type = rtm->rtm_type;
976 filter->table_id = rtm->rtm_table;
977
978 err = nlmsg_parse_deprecated_strict(nlh, hdrlen: sizeof(*rtm), tb, RTA_MAX,
979 policy: rtm_ipv4_policy, extack);
980 if (err < 0)
981 return err;
982
983 for (i = 0; i <= RTA_MAX; ++i) {
984 int ifindex;
985
986 if (!tb[i])
987 continue;
988
989 switch (i) {
990 case RTA_TABLE:
991 filter->table_id = nla_get_u32(nla: tb[i]);
992 break;
993 case RTA_OIF:
994 ifindex = nla_get_u32(nla: tb[i]);
995 if (filter->rtnl_held)
996 filter->dev = __dev_get_by_index(net, ifindex);
997 else
998 filter->dev = dev_get_by_index_rcu(net, ifindex);
999 if (!filter->dev)
1000 return -ENODEV;
1001 break;
1002 default:
1003 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
1004 return -EINVAL;
1005 }
1006 }
1007
1008 if (filter->flags || filter->protocol || filter->rt_type ||
1009 filter->table_id || filter->dev) {
1010 filter->filter_set = 1;
1011 cb->answer_flags = NLM_F_DUMP_FILTERED;
1012 }
1013
1014 return 0;
1015}
1016EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req);
1017
1018static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
1019{
1020 struct fib_dump_filter filter = {
1021 .dump_routes = true,
1022 .dump_exceptions = true,
1023 .rtnl_held = false,
1024 };
1025 const struct nlmsghdr *nlh = cb->nlh;
1026 struct net *net = sock_net(sk: skb->sk);
1027 unsigned int h, s_h;
1028 unsigned int e = 0, s_e;
1029 struct fib_table *tb;
1030 struct hlist_head *head;
1031 int dumped = 0, err = 0;
1032
1033 rcu_read_lock();
1034 if (cb->strict_check) {
1035 err = ip_valid_fib_dump_req(net, nlh, &filter, cb);
1036 if (err < 0)
1037 goto unlock;
1038 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
1039 struct rtmsg *rtm = nlmsg_data(nlh);
1040
1041 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED);
1042 }
1043
1044 /* ipv4 does not use prefix flag */
1045 if (filter.flags & RTM_F_PREFIX)
1046 goto unlock;
1047
1048 if (filter.table_id) {
1049 tb = fib_get_table(net, id: filter.table_id);
1050 if (!tb) {
1051 if (rtnl_msg_family(nlh: cb->nlh) != PF_INET)
1052 goto unlock;
1053
1054 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist");
1055 err = -ENOENT;
1056 goto unlock;
1057 }
1058 err = fib_table_dump(table: tb, skb, cb, filter: &filter);
1059 goto unlock;
1060 }
1061
1062 s_h = cb->args[0];
1063 s_e = cb->args[1];
1064
1065 err = 0;
1066 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
1067 e = 0;
1068 head = &net->ipv4.fib_table_hash[h];
1069 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
1070 if (e < s_e)
1071 goto next;
1072 if (dumped)
1073 memset(s: &cb->args[2], c: 0, n: sizeof(cb->args) -
1074 2 * sizeof(cb->args[0]));
1075 err = fib_table_dump(table: tb, skb, cb, filter: &filter);
1076 if (err < 0)
1077 goto out;
1078 dumped = 1;
1079next:
1080 e++;
1081 }
1082 }
1083out:
1084
1085 cb->args[1] = e;
1086 cb->args[0] = h;
1087
1088unlock:
1089 rcu_read_unlock();
1090 return err;
1091}
1092
1093/* Prepare and feed intra-kernel routing request.
1094 * Really, it should be netlink message, but :-( netlink
1095 * can be not configured, so that we feed it directly
1096 * to fib engine. It is legal, because all events occur
1097 * only when netlink is already locked.
1098 */
1099static void fib_magic(int cmd, int type, __be32 dst, int dst_len,
1100 struct in_ifaddr *ifa, u32 rt_priority)
1101{
1102 struct net *net = dev_net(dev: ifa->ifa_dev->dev);
1103 u32 tb_id = l3mdev_fib_table(dev: ifa->ifa_dev->dev);
1104 struct fib_table *tb;
1105 struct fib_config cfg = {
1106 .fc_protocol = RTPROT_KERNEL,
1107 .fc_type = type,
1108 .fc_dst = dst,
1109 .fc_dst_len = dst_len,
1110 .fc_priority = rt_priority,
1111 .fc_prefsrc = ifa->ifa_local,
1112 .fc_oif = ifa->ifa_dev->dev->ifindex,
1113 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
1114 .fc_nlinfo = {
1115 .nl_net = net,
1116 },
1117 };
1118
1119 if (!tb_id)
1120 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
1121
1122 tb = fib_new_table(net, tb_id);
1123 if (!tb)
1124 return;
1125
1126 cfg.fc_table = tb->tb_id;
1127
1128 if (type != RTN_LOCAL)
1129 cfg.fc_scope = RT_SCOPE_LINK;
1130 else
1131 cfg.fc_scope = RT_SCOPE_HOST;
1132
1133 if (cmd == RTM_NEWROUTE)
1134 fib_table_insert(net, tb, &cfg, NULL);
1135 else
1136 fib_table_delete(net, tb, &cfg, NULL);
1137}
1138
1139void fib_add_ifaddr(struct in_ifaddr *ifa)
1140{
1141 struct in_device *in_dev = ifa->ifa_dev;
1142 struct net_device *dev = in_dev->dev;
1143 struct in_ifaddr *prim = ifa;
1144 __be32 mask = ifa->ifa_mask;
1145 __be32 addr = ifa->ifa_local;
1146 __be32 prefix = ifa->ifa_address & mask;
1147
1148 if (ifa->ifa_flags & IFA_F_SECONDARY) {
1149 prim = inet_ifa_byprefix(in_dev, prefix, mask);
1150 if (!prim) {
1151 pr_warn("%s: bug: prim == NULL\n", __func__);
1152 return;
1153 }
1154 }
1155
1156 fib_magic(RTM_NEWROUTE, type: RTN_LOCAL, dst: addr, dst_len: 32, ifa: prim, rt_priority: 0);
1157
1158 if (!(dev->flags & IFF_UP))
1159 return;
1160
1161 /* Add broadcast address, if it is explicitly assigned. */
1162 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) {
1163 fib_magic(RTM_NEWROUTE, type: RTN_BROADCAST, dst: ifa->ifa_broadcast, dst_len: 32,
1164 ifa: prim, rt_priority: 0);
1165 arp_invalidate(dev, ip: ifa->ifa_broadcast, force: false);
1166 }
1167
1168 if (!ipv4_is_zeronet(addr: prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
1169 (prefix != addr || ifa->ifa_prefixlen < 32)) {
1170 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1171 fib_magic(RTM_NEWROUTE,
1172 type: dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1173 dst: prefix, dst_len: ifa->ifa_prefixlen, ifa: prim,
1174 rt_priority: ifa->ifa_rt_priority);
1175
1176 /* Add the network broadcast address, when it makes sense */
1177 if (ifa->ifa_prefixlen < 31) {
1178 fib_magic(RTM_NEWROUTE, type: RTN_BROADCAST, dst: prefix | ~mask,
1179 dst_len: 32, ifa: prim, rt_priority: 0);
1180 arp_invalidate(dev, ip: prefix | ~mask, force: false);
1181 }
1182 }
1183}
1184
1185void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric)
1186{
1187 __be32 prefix = ifa->ifa_address & ifa->ifa_mask;
1188 struct in_device *in_dev = ifa->ifa_dev;
1189 struct net_device *dev = in_dev->dev;
1190
1191 if (!(dev->flags & IFF_UP) ||
1192 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) ||
1193 ipv4_is_zeronet(addr: prefix) ||
1194 (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32))
1195 return;
1196
1197 /* add the new */
1198 fib_magic(RTM_NEWROUTE,
1199 type: dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1200 dst: prefix, dst_len: ifa->ifa_prefixlen, ifa, rt_priority: new_metric);
1201
1202 /* delete the old */
1203 fib_magic(RTM_DELROUTE,
1204 type: dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1205 dst: prefix, dst_len: ifa->ifa_prefixlen, ifa, rt_priority: ifa->ifa_rt_priority);
1206}
1207
1208/* Delete primary or secondary address.
1209 * Optionally, on secondary address promotion consider the addresses
1210 * from subnet iprim as deleted, even if they are in device list.
1211 * In this case the secondary ifa can be in device list.
1212 */
1213void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
1214{
1215 struct in_device *in_dev = ifa->ifa_dev;
1216 struct net_device *dev = in_dev->dev;
1217 struct in_ifaddr *ifa1;
1218 struct in_ifaddr *prim = ifa, *prim1 = NULL;
1219 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
1220 __be32 any = ifa->ifa_address & ifa->ifa_mask;
1221#define LOCAL_OK 1
1222#define BRD_OK 2
1223#define BRD0_OK 4
1224#define BRD1_OK 8
1225 unsigned int ok = 0;
1226 int subnet = 0; /* Primary network */
1227 int gone = 1; /* Address is missing */
1228 int same_prefsrc = 0; /* Another primary with same IP */
1229
1230 if (ifa->ifa_flags & IFA_F_SECONDARY) {
1231 prim = inet_ifa_byprefix(in_dev, prefix: any, mask: ifa->ifa_mask);
1232 if (!prim) {
1233 /* if the device has been deleted, we don't perform
1234 * address promotion
1235 */
1236 if (!in_dev->dead)
1237 pr_warn("%s: bug: prim == NULL\n", __func__);
1238 return;
1239 }
1240 if (iprim && iprim != prim) {
1241 pr_warn("%s: bug: iprim != prim\n", __func__);
1242 return;
1243 }
1244 } else if (!ipv4_is_zeronet(addr: any) &&
1245 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
1246 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1247 fib_magic(RTM_DELROUTE,
1248 type: dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1249 dst: any, dst_len: ifa->ifa_prefixlen, ifa: prim, rt_priority: 0);
1250 subnet = 1;
1251 }
1252
1253 if (in_dev->dead)
1254 goto no_promotions;
1255
1256 /* Deletion is more complicated than add.
1257 * We should take care of not to delete too much :-)
1258 *
1259 * Scan address list to be sure that addresses are really gone.
1260 */
1261 rcu_read_lock();
1262 in_dev_for_each_ifa_rcu(ifa1, in_dev) {
1263 if (ifa1 == ifa) {
1264 /* promotion, keep the IP */
1265 gone = 0;
1266 continue;
1267 }
1268 /* Ignore IFAs from our subnet */
1269 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
1270 inet_ifa_match(addr: ifa1->ifa_address, ifa: iprim))
1271 continue;
1272
1273 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
1274 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
1275 /* Another address from our subnet? */
1276 if (ifa1->ifa_mask == prim->ifa_mask &&
1277 inet_ifa_match(addr: ifa1->ifa_address, ifa: prim))
1278 prim1 = prim;
1279 else {
1280 /* We reached the secondaries, so
1281 * same_prefsrc should be determined.
1282 */
1283 if (!same_prefsrc)
1284 continue;
1285 /* Search new prim1 if ifa1 is not
1286 * using the current prim1
1287 */
1288 if (!prim1 ||
1289 ifa1->ifa_mask != prim1->ifa_mask ||
1290 !inet_ifa_match(addr: ifa1->ifa_address, ifa: prim1))
1291 prim1 = inet_ifa_byprefix(in_dev,
1292 prefix: ifa1->ifa_address,
1293 mask: ifa1->ifa_mask);
1294 if (!prim1)
1295 continue;
1296 if (prim1->ifa_local != prim->ifa_local)
1297 continue;
1298 }
1299 } else {
1300 if (prim->ifa_local != ifa1->ifa_local)
1301 continue;
1302 prim1 = ifa1;
1303 if (prim != prim1)
1304 same_prefsrc = 1;
1305 }
1306 if (ifa->ifa_local == ifa1->ifa_local)
1307 ok |= LOCAL_OK;
1308 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1309 ok |= BRD_OK;
1310 if (brd == ifa1->ifa_broadcast)
1311 ok |= BRD1_OK;
1312 if (any == ifa1->ifa_broadcast)
1313 ok |= BRD0_OK;
1314 /* primary has network specific broadcasts */
1315 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1316 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1317 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1318
1319 if (!ipv4_is_zeronet(addr: any1)) {
1320 if (ifa->ifa_broadcast == brd1 ||
1321 ifa->ifa_broadcast == any1)
1322 ok |= BRD_OK;
1323 if (brd == brd1 || brd == any1)
1324 ok |= BRD1_OK;
1325 if (any == brd1 || any == any1)
1326 ok |= BRD0_OK;
1327 }
1328 }
1329 }
1330 rcu_read_unlock();
1331
1332no_promotions:
1333 if (!(ok & BRD_OK))
1334 fib_magic(RTM_DELROUTE, type: RTN_BROADCAST, dst: ifa->ifa_broadcast, dst_len: 32,
1335 ifa: prim, rt_priority: 0);
1336 if (subnet && ifa->ifa_prefixlen < 31) {
1337 if (!(ok & BRD1_OK))
1338 fib_magic(RTM_DELROUTE, type: RTN_BROADCAST, dst: brd, dst_len: 32,
1339 ifa: prim, rt_priority: 0);
1340 if (!(ok & BRD0_OK))
1341 fib_magic(RTM_DELROUTE, type: RTN_BROADCAST, dst: any, dst_len: 32,
1342 ifa: prim, rt_priority: 0);
1343 }
1344 if (!(ok & LOCAL_OK)) {
1345 unsigned int addr_type;
1346
1347 fib_magic(RTM_DELROUTE, type: RTN_LOCAL, dst: ifa->ifa_local, dst_len: 32, ifa: prim, rt_priority: 0);
1348
1349 /* Check, that this local address finally disappeared. */
1350 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1351 ifa->ifa_local);
1352 if (gone && addr_type != RTN_LOCAL) {
1353 /* And the last, but not the least thing.
1354 * We must flush stray FIB entries.
1355 *
1356 * First of all, we scan fib_info list searching
1357 * for stray nexthop entries, then ignite fib_flush.
1358 */
1359 if (fib_sync_down_addr(dev, local: ifa->ifa_local))
1360 fib_flush(net: dev_net(dev));
1361 }
1362 }
1363#undef LOCAL_OK
1364#undef BRD_OK
1365#undef BRD0_OK
1366#undef BRD1_OK
1367}
1368
1369static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1370{
1371
1372 struct fib_result res;
1373 struct flowi4 fl4 = {
1374 .flowi4_mark = frn->fl_mark,
1375 .daddr = frn->fl_addr,
1376 .flowi4_dscp = inet_dsfield_to_dscp(dsfield: frn->fl_tos),
1377 .flowi4_scope = frn->fl_scope,
1378 };
1379 struct fib_table *tb;
1380
1381 rcu_read_lock();
1382
1383 tb = fib_get_table(net, id: frn->tb_id_in);
1384
1385 frn->err = -ENOENT;
1386 if (tb) {
1387 local_bh_disable();
1388
1389 frn->tb_id = tb->tb_id;
1390 frn->err = fib_table_lookup(tb, flp: &fl4, res: &res, FIB_LOOKUP_NOREF);
1391
1392 if (!frn->err) {
1393 frn->prefixlen = res.prefixlen;
1394 frn->nh_sel = res.nh_sel;
1395 frn->type = res.type;
1396 frn->scope = res.scope;
1397 }
1398 local_bh_enable();
1399 }
1400
1401 rcu_read_unlock();
1402}
1403
1404static void nl_fib_input(struct sk_buff *skb)
1405{
1406 struct net *net;
1407 struct fib_result_nl *frn;
1408 struct nlmsghdr *nlh;
1409 u32 portid;
1410
1411 net = sock_net(sk: skb->sk);
1412 nlh = nlmsg_hdr(skb);
1413 if (skb->len < nlmsg_total_size(payload: sizeof(*frn)) ||
1414 skb->len < nlh->nlmsg_len ||
1415 nlmsg_len(nlh) < sizeof(*frn))
1416 return;
1417
1418 skb = netlink_skb_clone(skb, GFP_KERNEL);
1419 if (!skb)
1420 return;
1421 nlh = nlmsg_hdr(skb);
1422
1423 frn = nlmsg_data(nlh);
1424 nl_fib_lookup(net, frn);
1425
1426 portid = NETLINK_CB(skb).portid; /* netlink portid */
1427 NETLINK_CB(skb).portid = 0; /* from kernel */
1428 NETLINK_CB(skb).dst_group = 0; /* unicast */
1429 nlmsg_unicast(sk: net->ipv4.fibnl, skb, portid);
1430}
1431
1432static int __net_init nl_fib_lookup_init(struct net *net)
1433{
1434 struct sock *sk;
1435 struct netlink_kernel_cfg cfg = {
1436 .input = nl_fib_input,
1437 };
1438
1439 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, cfg: &cfg);
1440 if (!sk)
1441 return -EAFNOSUPPORT;
1442 net->ipv4.fibnl = sk;
1443 return 0;
1444}
1445
1446static void nl_fib_lookup_exit(struct net *net)
1447{
1448 netlink_kernel_release(sk: net->ipv4.fibnl);
1449 net->ipv4.fibnl = NULL;
1450}
1451
1452static void fib_disable_ip(struct net_device *dev, unsigned long event,
1453 bool force)
1454{
1455 if (fib_sync_down_dev(dev, event, force))
1456 fib_flush(net: dev_net(dev));
1457 else
1458 rt_cache_flush(net: dev_net(dev));
1459 arp_ifdown(dev);
1460}
1461
1462static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1463{
1464 struct in_ifaddr *ifa = ptr;
1465 struct net_device *dev = ifa->ifa_dev->dev;
1466 struct net *net = dev_net(dev);
1467
1468 switch (event) {
1469 case NETDEV_UP:
1470 fib_add_ifaddr(ifa);
1471#ifdef CONFIG_IP_ROUTE_MULTIPATH
1472 fib_sync_up(dev, RTNH_F_DEAD);
1473#endif
1474 atomic_inc(v: &net->ipv4.dev_addr_genid);
1475 rt_cache_flush(net);
1476 break;
1477 case NETDEV_DOWN:
1478 fib_del_ifaddr(ifa, NULL);
1479 atomic_inc(v: &net->ipv4.dev_addr_genid);
1480 if (!ifa->ifa_dev->ifa_list) {
1481 /* Last address was deleted from this interface.
1482 * Disable IP.
1483 */
1484 fib_disable_ip(dev, event, force: true);
1485 } else {
1486 rt_cache_flush(net);
1487 }
1488 break;
1489 }
1490 return NOTIFY_DONE;
1491}
1492
1493static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1494{
1495 struct net_device *dev = netdev_notifier_info_to_dev(info: ptr);
1496 struct netdev_notifier_changeupper_info *upper_info = ptr;
1497 struct netdev_notifier_info_ext *info_ext = ptr;
1498 struct in_device *in_dev;
1499 struct net *net = dev_net(dev);
1500 struct in_ifaddr *ifa;
1501 unsigned int flags;
1502
1503 if (event == NETDEV_UNREGISTER) {
1504 fib_disable_ip(dev, event, force: true);
1505 rt_flush_dev(dev);
1506 return NOTIFY_DONE;
1507 }
1508
1509 in_dev = __in_dev_get_rtnl(dev);
1510 if (!in_dev)
1511 return NOTIFY_DONE;
1512
1513 switch (event) {
1514 case NETDEV_UP:
1515 in_dev_for_each_ifa_rtnl(ifa, in_dev) {
1516 fib_add_ifaddr(ifa);
1517 }
1518#ifdef CONFIG_IP_ROUTE_MULTIPATH
1519 fib_sync_up(dev, RTNH_F_DEAD);
1520#endif
1521 atomic_inc(v: &net->ipv4.dev_addr_genid);
1522 rt_cache_flush(net);
1523 break;
1524 case NETDEV_DOWN:
1525 fib_disable_ip(dev, event, force: false);
1526 break;
1527 case NETDEV_CHANGE:
1528 flags = netif_get_flags(dev);
1529 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1530 fib_sync_up(dev, RTNH_F_LINKDOWN);
1531 else
1532 fib_sync_down_dev(dev, event, force: false);
1533 rt_cache_flush(net);
1534 break;
1535 case NETDEV_CHANGEMTU:
1536 fib_sync_mtu(dev, orig_mtu: info_ext->ext.mtu);
1537 rt_cache_flush(net);
1538 break;
1539 case NETDEV_CHANGEUPPER:
1540 upper_info = ptr;
1541 /* flush all routes if dev is linked to or unlinked from
1542 * an L3 master device (e.g., VRF)
1543 */
1544 if (upper_info->upper_dev &&
1545 netif_is_l3_master(dev: upper_info->upper_dev))
1546 fib_disable_ip(dev, event: NETDEV_DOWN, force: true);
1547 break;
1548 }
1549 return NOTIFY_DONE;
1550}
1551
1552static struct notifier_block fib_inetaddr_notifier = {
1553 .notifier_call = fib_inetaddr_event,
1554};
1555
1556static struct notifier_block fib_netdev_notifier = {
1557 .notifier_call = fib_netdev_event,
1558};
1559
1560static int __net_init ip_fib_net_init(struct net *net)
1561{
1562 int err;
1563 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1564
1565 err = fib4_notifier_init(net);
1566 if (err)
1567 return err;
1568
1569#ifdef CONFIG_IP_ROUTE_MULTIPATH
1570 /* Default to 3-tuple */
1571 net->ipv4.sysctl_fib_multipath_hash_fields =
1572 FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK;
1573#endif
1574
1575 /* Avoid false sharing : Use at least a full cache line */
1576 size = max_t(size_t, size, L1_CACHE_BYTES);
1577
1578 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1579 if (!net->ipv4.fib_table_hash) {
1580 err = -ENOMEM;
1581 goto err_table_hash_alloc;
1582 }
1583
1584 err = fib4_rules_init(net);
1585 if (err < 0)
1586 goto err_rules_init;
1587 return 0;
1588
1589err_rules_init:
1590 kfree(objp: net->ipv4.fib_table_hash);
1591err_table_hash_alloc:
1592 fib4_notifier_exit(net);
1593 return err;
1594}
1595
1596static void ip_fib_net_exit(struct net *net)
1597{
1598 int i;
1599
1600 ASSERT_RTNL_NET(net);
1601#ifdef CONFIG_IP_MULTIPLE_TABLES
1602 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1603 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1604#endif
1605 /* Destroy the tables in reverse order to guarantee that the
1606 * local table, ID 255, is destroyed before the main table, ID
1607 * 254. This is necessary as the local table may contain
1608 * references to data contained in the main table.
1609 */
1610 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1611 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1612 struct hlist_node *tmp;
1613 struct fib_table *tb;
1614
1615 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1616 hlist_del(n: &tb->tb_hlist);
1617 fib_table_flush(net, table: tb, flush_all: true);
1618 fib_free_table(tb);
1619 }
1620 }
1621
1622#ifdef CONFIG_IP_MULTIPLE_TABLES
1623 fib4_rules_exit(net);
1624#endif
1625
1626 kfree(objp: net->ipv4.fib_table_hash);
1627 fib4_notifier_exit(net);
1628}
1629
1630static int __net_init fib_net_init(struct net *net)
1631{
1632 int error;
1633
1634#ifdef CONFIG_IP_ROUTE_CLASSID
1635 atomic_set(&net->ipv4.fib_num_tclassid_users, 0);
1636#endif
1637 error = ip_fib_net_init(net);
1638 if (error < 0)
1639 goto out;
1640
1641 error = fib4_semantics_init(net);
1642 if (error)
1643 goto out_semantics;
1644
1645 error = nl_fib_lookup_init(net);
1646 if (error < 0)
1647 goto out_nlfl;
1648
1649 error = fib_proc_init(net);
1650 if (error < 0)
1651 goto out_proc;
1652out:
1653 return error;
1654
1655out_proc:
1656 nl_fib_lookup_exit(net);
1657out_nlfl:
1658 fib4_semantics_exit(net);
1659out_semantics:
1660 rtnl_net_lock(net);
1661 ip_fib_net_exit(net);
1662 rtnl_net_unlock(net);
1663 goto out;
1664}
1665
1666static void __net_exit fib_net_exit(struct net *net)
1667{
1668 fib_proc_exit(net);
1669 nl_fib_lookup_exit(net);
1670}
1671
1672static void __net_exit fib_net_exit_batch(struct list_head *net_list)
1673{
1674 struct net *net;
1675
1676 rtnl_lock();
1677 list_for_each_entry(net, net_list, exit_list) {
1678 __rtnl_net_lock(net);
1679 ip_fib_net_exit(net);
1680 __rtnl_net_unlock(net);
1681 }
1682 rtnl_unlock();
1683
1684 list_for_each_entry(net, net_list, exit_list)
1685 fib4_semantics_exit(net);
1686}
1687
1688static struct pernet_operations fib_net_ops = {
1689 .init = fib_net_init,
1690 .exit = fib_net_exit,
1691 .exit_batch = fib_net_exit_batch,
1692};
1693
1694static const struct rtnl_msg_handler fib_rtnl_msg_handlers[] __initconst = {
1695 {.protocol = PF_INET, .msgtype = RTM_NEWROUTE,
1696 .doit = inet_rtm_newroute, .flags = RTNL_FLAG_DOIT_PERNET},
1697 {.protocol = PF_INET, .msgtype = RTM_DELROUTE,
1698 .doit = inet_rtm_delroute, .flags = RTNL_FLAG_DOIT_PERNET},
1699 {.protocol = PF_INET, .msgtype = RTM_GETROUTE, .dumpit = inet_dump_fib,
1700 .flags = RTNL_FLAG_DUMP_UNLOCKED | RTNL_FLAG_DUMP_SPLIT_NLM_DONE},
1701};
1702
1703void __init ip_fib_init(void)
1704{
1705 fib_trie_init();
1706
1707 register_pernet_subsys(&fib_net_ops);
1708
1709 register_netdevice_notifier(nb: &fib_netdev_notifier);
1710 register_inetaddr_notifier(nb: &fib_inetaddr_notifier);
1711
1712 rtnl_register_many(fib_rtnl_msg_handlers);
1713}
1714