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