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