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
fib4_rules_init(struct net * net)54 static 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
72 fail:
73 fib_free_table(main_table);
74 return -ENOMEM;
75 }
76
fib4_has_custom_rules(struct net * net)77 static bool fib4_has_custom_rules(struct net *net)
78 {
79 return false;
80 }
81 #else
82
fib_new_table(struct net * net,u32 id)83 struct 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 }
116 EXPORT_SYMBOL_GPL(fib_new_table);
117
118 /* caller must hold either rtnl or rcu read lock */
fib_get_table(struct net * net,u32 id)119 struct 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
fib4_has_custom_rules(struct net * net)137 static 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
fib_replace_table(struct net * net,struct fib_table * old,struct fib_table * new)143 static 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
fib_unmerge(struct net * net)163 int 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
fib_flush(struct net * net)195 static 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 */
__inet_dev_addr_type(struct net * net,const struct net_device * dev,__be32 addr,u32 tb_id)217 static 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
inet_addr_type_table(struct net * net,__be32 addr,u32 tb_id)246 unsigned 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 }
250 EXPORT_SYMBOL(inet_addr_type_table);
251
inet_addr_type(struct net * net,__be32 addr)252 unsigned int inet_addr_type(struct net *net, __be32 addr)
253 {
254 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
255 }
256 EXPORT_SYMBOL(inet_addr_type);
257
inet_dev_addr_type(struct net * net,const struct net_device * dev,__be32 addr)258 unsigned 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 }
265 EXPORT_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 */
inet_addr_type_dev_table(struct net * net,const struct net_device * dev,__be32 addr)270 unsigned 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 }
278 EXPORT_SYMBOL(inet_addr_type_dev_table);
279
fib_compute_spec_dst(struct sk_buff * skb)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
296 net = dev_net(dev);
297
298 scope = RT_SCOPE_UNIVERSE;
299 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
300 bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev);
301 struct flowi4 fl4 = {
302 .flowi4_iif = LOOPBACK_IFINDEX,
303 .flowi4_oif = l3mdev_master_ifindex_rcu(dev),
304 .daddr = ip_hdr(skb)->saddr,
305 .flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
306 .flowi4_scope = scope,
307 .flowi4_mark = vmark ? skb->mark : 0,
308 };
309 if (!fib_lookup(net, &fl4, &res, 0))
310 return FIB_RES_PREFSRC(net, res);
311 } else {
312 scope = RT_SCOPE_LINK;
313 }
314
315 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
316 }
317
318 /* Given (packet source, input interface) and optional (dst, oif, tos):
319 * - (main) check, that source is valid i.e. not broadcast or our local
320 * address.
321 * - figure out what "logical" interface this packet arrived
322 * and calculate "specific destination" address.
323 * - check, that packet arrived from expected physical interface.
324 * called with rcu_read_lock()
325 */
__fib_validate_source(struct sk_buff * skb,__be32 src,__be32 dst,u8 tos,int oif,struct net_device * dev,int rpf,struct in_device * idev,u32 * itag)326 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
327 u8 tos, int oif, struct net_device *dev,
328 int rpf, struct in_device *idev, u32 *itag)
329 {
330 struct net *net = dev_net(dev);
331 struct flow_keys flkeys;
332 int ret, no_addr;
333 struct fib_result res;
334 struct flowi4 fl4;
335 bool dev_match;
336
337 fl4.flowi4_oif = 0;
338 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
339 if (!fl4.flowi4_iif)
340 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
341 fl4.daddr = src;
342 fl4.saddr = dst;
343 fl4.flowi4_tos = tos;
344 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
345 fl4.flowi4_tun_key.tun_id = 0;
346 fl4.flowi4_flags = 0;
347 fl4.flowi4_uid = sock_net_uid(net, NULL);
348
349 no_addr = idev->ifa_list == NULL;
350
351 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
352 if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) {
353 fl4.flowi4_proto = 0;
354 fl4.fl4_sport = 0;
355 fl4.fl4_dport = 0;
356 }
357
358 if (fib_lookup(net, &fl4, &res, 0))
359 goto last_resort;
360 if (res.type != RTN_UNICAST &&
361 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
362 goto e_inval;
363 fib_combine_itag(itag, &res);
364 dev_match = false;
365
366 #ifdef CONFIG_IP_ROUTE_MULTIPATH
367 for (ret = 0; ret < res.fi->fib_nhs; ret++) {
368 struct fib_nh *nh = &res.fi->fib_nh[ret];
369
370 if (nh->nh_dev == dev) {
371 dev_match = true;
372 break;
373 } else if (l3mdev_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
374 dev_match = true;
375 break;
376 }
377 }
378 #else
379 if (FIB_RES_DEV(res) == dev)
380 dev_match = true;
381 #endif
382 if (dev_match) {
383 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
384 return ret;
385 }
386 if (no_addr)
387 goto last_resort;
388 if (rpf == 1)
389 goto e_rpf;
390 fl4.flowi4_oif = dev->ifindex;
391
392 ret = 0;
393 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
394 if (res.type == RTN_UNICAST)
395 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
396 }
397 return ret;
398
399 last_resort:
400 if (rpf)
401 goto e_rpf;
402 *itag = 0;
403 return 0;
404
405 e_inval:
406 return -EINVAL;
407 e_rpf:
408 return -EXDEV;
409 }
410
411 /* Ignore rp_filter for packets protected by IPsec. */
fib_validate_source(struct sk_buff * skb,__be32 src,__be32 dst,u8 tos,int oif,struct net_device * dev,struct in_device * idev,u32 * itag)412 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
413 u8 tos, int oif, struct net_device *dev,
414 struct in_device *idev, u32 *itag)
415 {
416 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
417 struct net *net = dev_net(dev);
418
419 if (!r && !fib_num_tclassid_users(net) &&
420 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
421 if (IN_DEV_ACCEPT_LOCAL(idev))
422 goto ok;
423 /* with custom local routes in place, checking local addresses
424 * only will be too optimistic, with custom rules, checking
425 * local addresses only can be too strict, e.g. due to vrf
426 */
427 if (net->ipv4.fib_has_custom_local_routes ||
428 fib4_has_custom_rules(net))
429 goto full_check;
430 if (inet_lookup_ifaddr_rcu(net, src))
431 return -EINVAL;
432
433 ok:
434 *itag = 0;
435 return 0;
436 }
437
438 full_check:
439 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
440 }
441
sk_extract_addr(struct sockaddr * addr)442 static inline __be32 sk_extract_addr(struct sockaddr *addr)
443 {
444 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
445 }
446
put_rtax(struct nlattr * mx,int len,int type,u32 value)447 static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
448 {
449 struct nlattr *nla;
450
451 nla = (struct nlattr *) ((char *) mx + len);
452 nla->nla_type = type;
453 nla->nla_len = nla_attr_size(4);
454 *(u32 *) nla_data(nla) = value;
455
456 return len + nla_total_size(4);
457 }
458
rtentry_to_fib_config(struct net * net,int cmd,struct rtentry * rt,struct fib_config * cfg)459 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
460 struct fib_config *cfg)
461 {
462 __be32 addr;
463 int plen;
464
465 memset(cfg, 0, sizeof(*cfg));
466 cfg->fc_nlinfo.nl_net = net;
467
468 if (rt->rt_dst.sa_family != AF_INET)
469 return -EAFNOSUPPORT;
470
471 /*
472 * Check mask for validity:
473 * a) it must be contiguous.
474 * b) destination must have all host bits clear.
475 * c) if application forgot to set correct family (AF_INET),
476 * reject request unless it is absolutely clear i.e.
477 * both family and mask are zero.
478 */
479 plen = 32;
480 addr = sk_extract_addr(&rt->rt_dst);
481 if (!(rt->rt_flags & RTF_HOST)) {
482 __be32 mask = sk_extract_addr(&rt->rt_genmask);
483
484 if (rt->rt_genmask.sa_family != AF_INET) {
485 if (mask || rt->rt_genmask.sa_family)
486 return -EAFNOSUPPORT;
487 }
488
489 if (bad_mask(mask, addr))
490 return -EINVAL;
491
492 plen = inet_mask_len(mask);
493 }
494
495 cfg->fc_dst_len = plen;
496 cfg->fc_dst = addr;
497
498 if (cmd != SIOCDELRT) {
499 cfg->fc_nlflags = NLM_F_CREATE;
500 cfg->fc_protocol = RTPROT_BOOT;
501 }
502
503 if (rt->rt_metric)
504 cfg->fc_priority = rt->rt_metric - 1;
505
506 if (rt->rt_flags & RTF_REJECT) {
507 cfg->fc_scope = RT_SCOPE_HOST;
508 cfg->fc_type = RTN_UNREACHABLE;
509 return 0;
510 }
511
512 cfg->fc_scope = RT_SCOPE_NOWHERE;
513 cfg->fc_type = RTN_UNICAST;
514
515 if (rt->rt_dev) {
516 char *colon;
517 struct net_device *dev;
518 char devname[IFNAMSIZ];
519
520 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
521 return -EFAULT;
522
523 devname[IFNAMSIZ-1] = 0;
524 colon = strchr(devname, ':');
525 if (colon)
526 *colon = 0;
527 dev = __dev_get_by_name(net, devname);
528 if (!dev)
529 return -ENODEV;
530 cfg->fc_oif = dev->ifindex;
531 cfg->fc_table = l3mdev_fib_table(dev);
532 if (colon) {
533 struct in_ifaddr *ifa;
534 struct in_device *in_dev = __in_dev_get_rtnl(dev);
535 if (!in_dev)
536 return -ENODEV;
537 *colon = ':';
538 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
539 if (strcmp(ifa->ifa_label, devname) == 0)
540 break;
541 if (!ifa)
542 return -ENODEV;
543 cfg->fc_prefsrc = ifa->ifa_local;
544 }
545 }
546
547 addr = sk_extract_addr(&rt->rt_gateway);
548 if (rt->rt_gateway.sa_family == AF_INET && addr) {
549 unsigned int addr_type;
550
551 cfg->fc_gw = addr;
552 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
553 if (rt->rt_flags & RTF_GATEWAY &&
554 addr_type == RTN_UNICAST)
555 cfg->fc_scope = RT_SCOPE_UNIVERSE;
556 }
557
558 if (cmd == SIOCDELRT)
559 return 0;
560
561 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
562 return -EINVAL;
563
564 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
565 cfg->fc_scope = RT_SCOPE_LINK;
566
567 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
568 struct nlattr *mx;
569 int len = 0;
570
571 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL);
572 if (!mx)
573 return -ENOMEM;
574
575 if (rt->rt_flags & RTF_MTU)
576 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
577
578 if (rt->rt_flags & RTF_WINDOW)
579 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
580
581 if (rt->rt_flags & RTF_IRTT)
582 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
583
584 cfg->fc_mx = mx;
585 cfg->fc_mx_len = len;
586 }
587
588 return 0;
589 }
590
591 /*
592 * Handle IP routing ioctl calls.
593 * These are used to manipulate the routing tables
594 */
ip_rt_ioctl(struct net * net,unsigned int cmd,struct rtentry * rt)595 int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
596 {
597 struct fib_config cfg;
598 int err;
599
600 switch (cmd) {
601 case SIOCADDRT: /* Add a route */
602 case SIOCDELRT: /* Delete a route */
603 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
604 return -EPERM;
605
606 rtnl_lock();
607 err = rtentry_to_fib_config(net, cmd, rt, &cfg);
608 if (err == 0) {
609 struct fib_table *tb;
610
611 if (cmd == SIOCDELRT) {
612 tb = fib_get_table(net, cfg.fc_table);
613 if (tb)
614 err = fib_table_delete(net, tb, &cfg,
615 NULL);
616 else
617 err = -ESRCH;
618 } else {
619 tb = fib_new_table(net, cfg.fc_table);
620 if (tb)
621 err = fib_table_insert(net, tb,
622 &cfg, NULL);
623 else
624 err = -ENOBUFS;
625 }
626
627 /* allocated by rtentry_to_fib_config() */
628 kfree(cfg.fc_mx);
629 }
630 rtnl_unlock();
631 return err;
632 }
633 return -EINVAL;
634 }
635
636 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
637 [RTA_DST] = { .type = NLA_U32 },
638 [RTA_SRC] = { .type = NLA_U32 },
639 [RTA_IIF] = { .type = NLA_U32 },
640 [RTA_OIF] = { .type = NLA_U32 },
641 [RTA_GATEWAY] = { .type = NLA_U32 },
642 [RTA_PRIORITY] = { .type = NLA_U32 },
643 [RTA_PREFSRC] = { .type = NLA_U32 },
644 [RTA_METRICS] = { .type = NLA_NESTED },
645 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
646 [RTA_FLOW] = { .type = NLA_U32 },
647 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
648 [RTA_ENCAP] = { .type = NLA_NESTED },
649 [RTA_UID] = { .type = NLA_U32 },
650 [RTA_MARK] = { .type = NLA_U32 },
651 [RTA_TABLE] = { .type = NLA_U32 },
652 [RTA_IP_PROTO] = { .type = NLA_U8 },
653 [RTA_SPORT] = { .type = NLA_U16 },
654 [RTA_DPORT] = { .type = NLA_U16 },
655 };
656
rtm_to_fib_config(struct net * net,struct sk_buff * skb,struct nlmsghdr * nlh,struct fib_config * cfg,struct netlink_ext_ack * extack)657 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
658 struct nlmsghdr *nlh, struct fib_config *cfg,
659 struct netlink_ext_ack *extack)
660 {
661 struct nlattr *attr;
662 int err, remaining;
663 struct rtmsg *rtm;
664
665 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy,
666 extack);
667 if (err < 0)
668 goto errout;
669
670 memset(cfg, 0, sizeof(*cfg));
671
672 rtm = nlmsg_data(nlh);
673 cfg->fc_dst_len = rtm->rtm_dst_len;
674 cfg->fc_tos = rtm->rtm_tos;
675 cfg->fc_table = rtm->rtm_table;
676 cfg->fc_protocol = rtm->rtm_protocol;
677 cfg->fc_scope = rtm->rtm_scope;
678 cfg->fc_type = rtm->rtm_type;
679 cfg->fc_flags = rtm->rtm_flags;
680 cfg->fc_nlflags = nlh->nlmsg_flags;
681
682 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
683 cfg->fc_nlinfo.nlh = nlh;
684 cfg->fc_nlinfo.nl_net = net;
685
686 if (cfg->fc_type > RTN_MAX) {
687 NL_SET_ERR_MSG(extack, "Invalid route type");
688 err = -EINVAL;
689 goto errout;
690 }
691
692 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
693 switch (nla_type(attr)) {
694 case RTA_DST:
695 cfg->fc_dst = nla_get_be32(attr);
696 break;
697 case RTA_OIF:
698 cfg->fc_oif = nla_get_u32(attr);
699 break;
700 case RTA_GATEWAY:
701 cfg->fc_gw = nla_get_be32(attr);
702 break;
703 case RTA_PRIORITY:
704 cfg->fc_priority = nla_get_u32(attr);
705 break;
706 case RTA_PREFSRC:
707 cfg->fc_prefsrc = nla_get_be32(attr);
708 break;
709 case RTA_METRICS:
710 cfg->fc_mx = nla_data(attr);
711 cfg->fc_mx_len = nla_len(attr);
712 break;
713 case RTA_MULTIPATH:
714 err = lwtunnel_valid_encap_type_attr(nla_data(attr),
715 nla_len(attr),
716 extack);
717 if (err < 0)
718 goto errout;
719 cfg->fc_mp = nla_data(attr);
720 cfg->fc_mp_len = nla_len(attr);
721 break;
722 case RTA_FLOW:
723 cfg->fc_flow = nla_get_u32(attr);
724 break;
725 case RTA_TABLE:
726 cfg->fc_table = nla_get_u32(attr);
727 break;
728 case RTA_ENCAP:
729 cfg->fc_encap = attr;
730 break;
731 case RTA_ENCAP_TYPE:
732 cfg->fc_encap_type = nla_get_u16(attr);
733 err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
734 extack);
735 if (err < 0)
736 goto errout;
737 break;
738 }
739 }
740
741 return 0;
742 errout:
743 return err;
744 }
745
inet_rtm_delroute(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)746 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
747 struct netlink_ext_ack *extack)
748 {
749 struct net *net = sock_net(skb->sk);
750 struct fib_config cfg;
751 struct fib_table *tb;
752 int err;
753
754 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
755 if (err < 0)
756 goto errout;
757
758 tb = fib_get_table(net, cfg.fc_table);
759 if (!tb) {
760 NL_SET_ERR_MSG(extack, "FIB table does not exist");
761 err = -ESRCH;
762 goto errout;
763 }
764
765 err = fib_table_delete(net, tb, &cfg, extack);
766 errout:
767 return err;
768 }
769
inet_rtm_newroute(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)770 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
771 struct netlink_ext_ack *extack)
772 {
773 struct net *net = sock_net(skb->sk);
774 struct fib_config cfg;
775 struct fib_table *tb;
776 int err;
777
778 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
779 if (err < 0)
780 goto errout;
781
782 tb = fib_new_table(net, cfg.fc_table);
783 if (!tb) {
784 err = -ENOBUFS;
785 goto errout;
786 }
787
788 err = fib_table_insert(net, tb, &cfg, extack);
789 if (!err && cfg.fc_type == RTN_LOCAL)
790 net->ipv4.fib_has_custom_local_routes = true;
791 errout:
792 return err;
793 }
794
inet_dump_fib(struct sk_buff * skb,struct netlink_callback * cb)795 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
796 {
797 struct net *net = sock_net(skb->sk);
798 unsigned int h, s_h;
799 unsigned int e = 0, s_e;
800 struct fib_table *tb;
801 struct hlist_head *head;
802 int dumped = 0, err;
803
804 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
805 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
806 return skb->len;
807
808 s_h = cb->args[0];
809 s_e = cb->args[1];
810
811 rcu_read_lock();
812
813 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
814 e = 0;
815 head = &net->ipv4.fib_table_hash[h];
816 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
817 if (e < s_e)
818 goto next;
819 if (dumped)
820 memset(&cb->args[2], 0, sizeof(cb->args) -
821 2 * sizeof(cb->args[0]));
822 err = fib_table_dump(tb, skb, cb);
823 if (err < 0) {
824 if (likely(skb->len))
825 goto out;
826
827 goto out_err;
828 }
829 dumped = 1;
830 next:
831 e++;
832 }
833 }
834 out:
835 err = skb->len;
836 out_err:
837 rcu_read_unlock();
838
839 cb->args[1] = e;
840 cb->args[0] = h;
841
842 return err;
843 }
844
845 /* Prepare and feed intra-kernel routing request.
846 * Really, it should be netlink message, but :-( netlink
847 * can be not configured, so that we feed it directly
848 * to fib engine. It is legal, because all events occur
849 * only when netlink is already locked.
850 */
fib_magic(int cmd,int type,__be32 dst,int dst_len,struct in_ifaddr * ifa,u32 rt_priority)851 static void fib_magic(int cmd, int type, __be32 dst, int dst_len,
852 struct in_ifaddr *ifa, u32 rt_priority)
853 {
854 struct net *net = dev_net(ifa->ifa_dev->dev);
855 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
856 struct fib_table *tb;
857 struct fib_config cfg = {
858 .fc_protocol = RTPROT_KERNEL,
859 .fc_type = type,
860 .fc_dst = dst,
861 .fc_dst_len = dst_len,
862 .fc_priority = rt_priority,
863 .fc_prefsrc = ifa->ifa_local,
864 .fc_oif = ifa->ifa_dev->dev->ifindex,
865 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
866 .fc_nlinfo = {
867 .nl_net = net,
868 },
869 };
870
871 if (!tb_id)
872 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
873
874 tb = fib_new_table(net, tb_id);
875 if (!tb)
876 return;
877
878 cfg.fc_table = tb->tb_id;
879
880 if (type != RTN_LOCAL)
881 cfg.fc_scope = RT_SCOPE_LINK;
882 else
883 cfg.fc_scope = RT_SCOPE_HOST;
884
885 if (cmd == RTM_NEWROUTE)
886 fib_table_insert(net, tb, &cfg, NULL);
887 else
888 fib_table_delete(net, tb, &cfg, NULL);
889 }
890
fib_add_ifaddr(struct in_ifaddr * ifa)891 void fib_add_ifaddr(struct in_ifaddr *ifa)
892 {
893 struct in_device *in_dev = ifa->ifa_dev;
894 struct net_device *dev = in_dev->dev;
895 struct in_ifaddr *prim = ifa;
896 __be32 mask = ifa->ifa_mask;
897 __be32 addr = ifa->ifa_local;
898 __be32 prefix = ifa->ifa_address & mask;
899
900 if (ifa->ifa_flags & IFA_F_SECONDARY) {
901 prim = inet_ifa_byprefix(in_dev, prefix, mask);
902 if (!prim) {
903 pr_warn("%s: bug: prim == NULL\n", __func__);
904 return;
905 }
906 }
907
908 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0);
909
910 if (!(dev->flags & IFF_UP))
911 return;
912
913 /* Add broadcast address, if it is explicitly assigned. */
914 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
915 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
916 prim, 0);
917
918 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
919 (prefix != addr || ifa->ifa_prefixlen < 32)) {
920 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
921 fib_magic(RTM_NEWROUTE,
922 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
923 prefix, ifa->ifa_prefixlen, prim,
924 ifa->ifa_rt_priority);
925
926 /* Add network specific broadcasts, when it takes a sense */
927 if (ifa->ifa_prefixlen < 31) {
928 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32,
929 prim, 0);
930 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
931 32, prim, 0);
932 }
933 }
934 }
935
fib_modify_prefix_metric(struct in_ifaddr * ifa,u32 new_metric)936 void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric)
937 {
938 __be32 prefix = ifa->ifa_address & ifa->ifa_mask;
939 struct in_device *in_dev = ifa->ifa_dev;
940 struct net_device *dev = in_dev->dev;
941
942 if (!(dev->flags & IFF_UP) ||
943 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) ||
944 ipv4_is_zeronet(prefix) ||
945 prefix == ifa->ifa_local || ifa->ifa_prefixlen == 32)
946 return;
947
948 /* add the new */
949 fib_magic(RTM_NEWROUTE,
950 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
951 prefix, ifa->ifa_prefixlen, ifa, new_metric);
952
953 /* delete the old */
954 fib_magic(RTM_DELROUTE,
955 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
956 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority);
957 }
958
959 /* Delete primary or secondary address.
960 * Optionally, on secondary address promotion consider the addresses
961 * from subnet iprim as deleted, even if they are in device list.
962 * In this case the secondary ifa can be in device list.
963 */
fib_del_ifaddr(struct in_ifaddr * ifa,struct in_ifaddr * iprim)964 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
965 {
966 struct in_device *in_dev = ifa->ifa_dev;
967 struct net_device *dev = in_dev->dev;
968 struct in_ifaddr *ifa1;
969 struct in_ifaddr *prim = ifa, *prim1 = NULL;
970 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
971 __be32 any = ifa->ifa_address & ifa->ifa_mask;
972 #define LOCAL_OK 1
973 #define BRD_OK 2
974 #define BRD0_OK 4
975 #define BRD1_OK 8
976 unsigned int ok = 0;
977 int subnet = 0; /* Primary network */
978 int gone = 1; /* Address is missing */
979 int same_prefsrc = 0; /* Another primary with same IP */
980
981 if (ifa->ifa_flags & IFA_F_SECONDARY) {
982 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
983 if (!prim) {
984 /* if the device has been deleted, we don't perform
985 * address promotion
986 */
987 if (!in_dev->dead)
988 pr_warn("%s: bug: prim == NULL\n", __func__);
989 return;
990 }
991 if (iprim && iprim != prim) {
992 pr_warn("%s: bug: iprim != prim\n", __func__);
993 return;
994 }
995 } else if (!ipv4_is_zeronet(any) &&
996 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
997 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
998 fib_magic(RTM_DELROUTE,
999 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1000 any, ifa->ifa_prefixlen, prim, 0);
1001 subnet = 1;
1002 }
1003
1004 if (in_dev->dead)
1005 goto no_promotions;
1006
1007 /* Deletion is more complicated than add.
1008 * We should take care of not to delete too much :-)
1009 *
1010 * Scan address list to be sure that addresses are really gone.
1011 */
1012
1013 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
1014 if (ifa1 == ifa) {
1015 /* promotion, keep the IP */
1016 gone = 0;
1017 continue;
1018 }
1019 /* Ignore IFAs from our subnet */
1020 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
1021 inet_ifa_match(ifa1->ifa_address, iprim))
1022 continue;
1023
1024 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
1025 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
1026 /* Another address from our subnet? */
1027 if (ifa1->ifa_mask == prim->ifa_mask &&
1028 inet_ifa_match(ifa1->ifa_address, prim))
1029 prim1 = prim;
1030 else {
1031 /* We reached the secondaries, so
1032 * same_prefsrc should be determined.
1033 */
1034 if (!same_prefsrc)
1035 continue;
1036 /* Search new prim1 if ifa1 is not
1037 * using the current prim1
1038 */
1039 if (!prim1 ||
1040 ifa1->ifa_mask != prim1->ifa_mask ||
1041 !inet_ifa_match(ifa1->ifa_address, prim1))
1042 prim1 = inet_ifa_byprefix(in_dev,
1043 ifa1->ifa_address,
1044 ifa1->ifa_mask);
1045 if (!prim1)
1046 continue;
1047 if (prim1->ifa_local != prim->ifa_local)
1048 continue;
1049 }
1050 } else {
1051 if (prim->ifa_local != ifa1->ifa_local)
1052 continue;
1053 prim1 = ifa1;
1054 if (prim != prim1)
1055 same_prefsrc = 1;
1056 }
1057 if (ifa->ifa_local == ifa1->ifa_local)
1058 ok |= LOCAL_OK;
1059 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1060 ok |= BRD_OK;
1061 if (brd == ifa1->ifa_broadcast)
1062 ok |= BRD1_OK;
1063 if (any == ifa1->ifa_broadcast)
1064 ok |= BRD0_OK;
1065 /* primary has network specific broadcasts */
1066 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1067 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1068 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1069
1070 if (!ipv4_is_zeronet(any1)) {
1071 if (ifa->ifa_broadcast == brd1 ||
1072 ifa->ifa_broadcast == any1)
1073 ok |= BRD_OK;
1074 if (brd == brd1 || brd == any1)
1075 ok |= BRD1_OK;
1076 if (any == brd1 || any == any1)
1077 ok |= BRD0_OK;
1078 }
1079 }
1080 }
1081
1082 no_promotions:
1083 if (!(ok & BRD_OK))
1084 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1085 prim, 0);
1086 if (subnet && ifa->ifa_prefixlen < 31) {
1087 if (!(ok & BRD1_OK))
1088 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32,
1089 prim, 0);
1090 if (!(ok & BRD0_OK))
1091 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32,
1092 prim, 0);
1093 }
1094 if (!(ok & LOCAL_OK)) {
1095 unsigned int addr_type;
1096
1097 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0);
1098
1099 /* Check, that this local address finally disappeared. */
1100 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1101 ifa->ifa_local);
1102 if (gone && addr_type != RTN_LOCAL) {
1103 /* And the last, but not the least thing.
1104 * We must flush stray FIB entries.
1105 *
1106 * First of all, we scan fib_info list searching
1107 * for stray nexthop entries, then ignite fib_flush.
1108 */
1109 if (fib_sync_down_addr(dev, ifa->ifa_local))
1110 fib_flush(dev_net(dev));
1111 }
1112 }
1113 #undef LOCAL_OK
1114 #undef BRD_OK
1115 #undef BRD0_OK
1116 #undef BRD1_OK
1117 }
1118
nl_fib_lookup(struct net * net,struct fib_result_nl * frn)1119 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1120 {
1121
1122 struct fib_result res;
1123 struct flowi4 fl4 = {
1124 .flowi4_mark = frn->fl_mark,
1125 .daddr = frn->fl_addr,
1126 .flowi4_tos = frn->fl_tos,
1127 .flowi4_scope = frn->fl_scope,
1128 };
1129 struct fib_table *tb;
1130
1131 rcu_read_lock();
1132
1133 tb = fib_get_table(net, frn->tb_id_in);
1134
1135 frn->err = -ENOENT;
1136 if (tb) {
1137 local_bh_disable();
1138
1139 frn->tb_id = tb->tb_id;
1140 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1141
1142 if (!frn->err) {
1143 frn->prefixlen = res.prefixlen;
1144 frn->nh_sel = res.nh_sel;
1145 frn->type = res.type;
1146 frn->scope = res.scope;
1147 }
1148 local_bh_enable();
1149 }
1150
1151 rcu_read_unlock();
1152 }
1153
nl_fib_input(struct sk_buff * skb)1154 static void nl_fib_input(struct sk_buff *skb)
1155 {
1156 struct net *net;
1157 struct fib_result_nl *frn;
1158 struct nlmsghdr *nlh;
1159 u32 portid;
1160
1161 net = sock_net(skb->sk);
1162 nlh = nlmsg_hdr(skb);
1163 if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1164 skb->len < nlh->nlmsg_len ||
1165 nlmsg_len(nlh) < sizeof(*frn))
1166 return;
1167
1168 skb = netlink_skb_clone(skb, GFP_KERNEL);
1169 if (!skb)
1170 return;
1171 nlh = nlmsg_hdr(skb);
1172
1173 frn = (struct fib_result_nl *) nlmsg_data(nlh);
1174 nl_fib_lookup(net, frn);
1175
1176 portid = NETLINK_CB(skb).portid; /* netlink portid */
1177 NETLINK_CB(skb).portid = 0; /* from kernel */
1178 NETLINK_CB(skb).dst_group = 0; /* unicast */
1179 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1180 }
1181
nl_fib_lookup_init(struct net * net)1182 static int __net_init nl_fib_lookup_init(struct net *net)
1183 {
1184 struct sock *sk;
1185 struct netlink_kernel_cfg cfg = {
1186 .input = nl_fib_input,
1187 };
1188
1189 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1190 if (!sk)
1191 return -EAFNOSUPPORT;
1192 net->ipv4.fibnl = sk;
1193 return 0;
1194 }
1195
nl_fib_lookup_exit(struct net * net)1196 static void nl_fib_lookup_exit(struct net *net)
1197 {
1198 netlink_kernel_release(net->ipv4.fibnl);
1199 net->ipv4.fibnl = NULL;
1200 }
1201
fib_disable_ip(struct net_device * dev,unsigned long event,bool force)1202 static void fib_disable_ip(struct net_device *dev, unsigned long event,
1203 bool force)
1204 {
1205 if (fib_sync_down_dev(dev, event, force))
1206 fib_flush(dev_net(dev));
1207 else
1208 rt_cache_flush(dev_net(dev));
1209 arp_ifdown(dev);
1210 }
1211
fib_inetaddr_event(struct notifier_block * this,unsigned long event,void * ptr)1212 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1213 {
1214 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1215 struct net_device *dev = ifa->ifa_dev->dev;
1216 struct net *net = dev_net(dev);
1217
1218 switch (event) {
1219 case NETDEV_UP:
1220 fib_add_ifaddr(ifa);
1221 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1222 fib_sync_up(dev, RTNH_F_DEAD);
1223 #endif
1224 atomic_inc(&net->ipv4.dev_addr_genid);
1225 rt_cache_flush(dev_net(dev));
1226 break;
1227 case NETDEV_DOWN:
1228 fib_del_ifaddr(ifa, NULL);
1229 atomic_inc(&net->ipv4.dev_addr_genid);
1230 if (!ifa->ifa_dev->ifa_list) {
1231 /* Last address was deleted from this interface.
1232 * Disable IP.
1233 */
1234 fib_disable_ip(dev, event, true);
1235 } else {
1236 rt_cache_flush(dev_net(dev));
1237 }
1238 break;
1239 }
1240 return NOTIFY_DONE;
1241 }
1242
fib_netdev_event(struct notifier_block * this,unsigned long event,void * ptr)1243 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1244 {
1245 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1246 struct netdev_notifier_changeupper_info *upper_info = ptr;
1247 struct netdev_notifier_info_ext *info_ext = ptr;
1248 struct in_device *in_dev;
1249 struct net *net = dev_net(dev);
1250 unsigned int flags;
1251
1252 if (event == NETDEV_UNREGISTER) {
1253 fib_disable_ip(dev, event, true);
1254 rt_flush_dev(dev);
1255 return NOTIFY_DONE;
1256 }
1257
1258 in_dev = __in_dev_get_rtnl(dev);
1259 if (!in_dev)
1260 return NOTIFY_DONE;
1261
1262 switch (event) {
1263 case NETDEV_UP:
1264 for_ifa(in_dev) {
1265 fib_add_ifaddr(ifa);
1266 } endfor_ifa(in_dev);
1267 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1268 fib_sync_up(dev, RTNH_F_DEAD);
1269 #endif
1270 atomic_inc(&net->ipv4.dev_addr_genid);
1271 rt_cache_flush(net);
1272 break;
1273 case NETDEV_DOWN:
1274 fib_disable_ip(dev, event, false);
1275 break;
1276 case NETDEV_CHANGE:
1277 flags = dev_get_flags(dev);
1278 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1279 fib_sync_up(dev, RTNH_F_LINKDOWN);
1280 else
1281 fib_sync_down_dev(dev, event, false);
1282 rt_cache_flush(net);
1283 break;
1284 case NETDEV_CHANGEMTU:
1285 fib_sync_mtu(dev, info_ext->ext.mtu);
1286 rt_cache_flush(net);
1287 break;
1288 case NETDEV_CHANGEUPPER:
1289 upper_info = ptr;
1290 /* flush all routes if dev is linked to or unlinked from
1291 * an L3 master device (e.g., VRF)
1292 */
1293 if (upper_info->upper_dev &&
1294 netif_is_l3_master(upper_info->upper_dev))
1295 fib_disable_ip(dev, NETDEV_DOWN, true);
1296 break;
1297 }
1298 return NOTIFY_DONE;
1299 }
1300
1301 static struct notifier_block fib_inetaddr_notifier = {
1302 .notifier_call = fib_inetaddr_event,
1303 };
1304
1305 static struct notifier_block fib_netdev_notifier = {
1306 .notifier_call = fib_netdev_event,
1307 };
1308
ip_fib_net_init(struct net * net)1309 static int __net_init ip_fib_net_init(struct net *net)
1310 {
1311 int err;
1312 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1313
1314 err = fib4_notifier_init(net);
1315 if (err)
1316 return err;
1317
1318 /* Avoid false sharing : Use at least a full cache line */
1319 size = max_t(size_t, size, L1_CACHE_BYTES);
1320
1321 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1322 if (!net->ipv4.fib_table_hash) {
1323 err = -ENOMEM;
1324 goto err_table_hash_alloc;
1325 }
1326
1327 err = fib4_rules_init(net);
1328 if (err < 0)
1329 goto err_rules_init;
1330 return 0;
1331
1332 err_rules_init:
1333 kfree(net->ipv4.fib_table_hash);
1334 err_table_hash_alloc:
1335 fib4_notifier_exit(net);
1336 return err;
1337 }
1338
ip_fib_net_exit(struct net * net)1339 static void ip_fib_net_exit(struct net *net)
1340 {
1341 int i;
1342
1343 rtnl_lock();
1344 #ifdef CONFIG_IP_MULTIPLE_TABLES
1345 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1346 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1347 #endif
1348 /* Destroy the tables in reverse order to guarantee that the
1349 * local table, ID 255, is destroyed before the main table, ID
1350 * 254. This is necessary as the local table may contain
1351 * references to data contained in the main table.
1352 */
1353 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1354 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1355 struct hlist_node *tmp;
1356 struct fib_table *tb;
1357
1358 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1359 hlist_del(&tb->tb_hlist);
1360 fib_table_flush(net, tb);
1361 fib_free_table(tb);
1362 }
1363 }
1364
1365 #ifdef CONFIG_IP_MULTIPLE_TABLES
1366 fib4_rules_exit(net);
1367 #endif
1368 rtnl_unlock();
1369 kfree(net->ipv4.fib_table_hash);
1370 fib4_notifier_exit(net);
1371 }
1372
fib_net_init(struct net * net)1373 static int __net_init fib_net_init(struct net *net)
1374 {
1375 int error;
1376
1377 #ifdef CONFIG_IP_ROUTE_CLASSID
1378 net->ipv4.fib_num_tclassid_users = 0;
1379 #endif
1380 error = ip_fib_net_init(net);
1381 if (error < 0)
1382 goto out;
1383 error = nl_fib_lookup_init(net);
1384 if (error < 0)
1385 goto out_nlfl;
1386 error = fib_proc_init(net);
1387 if (error < 0)
1388 goto out_proc;
1389 out:
1390 return error;
1391
1392 out_proc:
1393 nl_fib_lookup_exit(net);
1394 out_nlfl:
1395 ip_fib_net_exit(net);
1396 goto out;
1397 }
1398
fib_net_exit(struct net * net)1399 static void __net_exit fib_net_exit(struct net *net)
1400 {
1401 fib_proc_exit(net);
1402 nl_fib_lookup_exit(net);
1403 ip_fib_net_exit(net);
1404 }
1405
1406 static struct pernet_operations fib_net_ops = {
1407 .init = fib_net_init,
1408 .exit = fib_net_exit,
1409 };
1410
ip_fib_init(void)1411 void __init ip_fib_init(void)
1412 {
1413 fib_trie_init();
1414
1415 register_pernet_subsys(&fib_net_ops);
1416
1417 register_netdevice_notifier(&fib_netdev_notifier);
1418 register_inetaddr_notifier(&fib_inetaddr_notifier);
1419
1420 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0);
1421 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0);
1422 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0);
1423 }
1424
