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Merge remote-tracking branch 'sysctl/master'
[linux-2.6/next.git] / net / ipv4 / fib_frontend.c
blob92fc5f69f5da1c36aff62213d0c6bca358e624f7
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * IPv4 Forwarding Information Base: FIB frontend.
7 *
8 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 */
15
16 #include <linux/module.h>
17 #include <asm/uaccess.h>
18 #include <asm/system.h>
19 #include <linux/bitops.h>
20 #include <linux/capability.h>
21 #include <linux/types.h>
22 #include <linux/kernel.h>
23 #include <linux/mm.h>
24 #include <linux/string.h>
25 #include <linux/socket.h>
26 #include <linux/sockios.h>
27 #include <linux/errno.h>
28 #include <linux/in.h>
29 #include <linux/inet.h>
30 #include <linux/inetdevice.h>
31 #include <linux/netdevice.h>
32 #include <linux/if_addr.h>
33 #include <linux/if_arp.h>
34 #include <linux/skbuff.h>
35 #include <linux/init.h>
36 #include <linux/list.h>
37 #include <linux/slab.h>
38
39 #include <net/ip.h>
40 #include <net/protocol.h>
41 #include <net/route.h>
42 #include <net/tcp.h>
43 #include <net/sock.h>
44 #include <net/arp.h>
45 #include <net/ip_fib.h>
46 #include <net/rtnetlink.h>
47 #include <net/xfrm.h>
48
49 #ifndef CONFIG_IP_MULTIPLE_TABLES
50
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 kfree(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 h = id & (FIB_TABLE_HASHSZ - 1);
90 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
91 return tb;
92 }
93
94 struct fib_table *fib_get_table(struct net *net, u32 id)
95 {
96 struct fib_table *tb;
97 struct hlist_node *node;
98 struct hlist_head *head;
99 unsigned int h;
100
101 if (id == 0)
102 id = RT_TABLE_MAIN;
103 h = id & (FIB_TABLE_HASHSZ - 1);
104
105 rcu_read_lock();
106 head = &net->ipv4.fib_table_hash[h];
107 hlist_for_each_entry_rcu(tb, node, head, tb_hlist) {
108 if (tb->tb_id == id) {
109 rcu_read_unlock();
110 return tb;
111 }
112 }
113 rcu_read_unlock();
114 return NULL;
115 }
116 #endif /* CONFIG_IP_MULTIPLE_TABLES */
117
118 static void fib_flush(struct net *net)
119 {
120 int flushed = 0;
121 struct fib_table *tb;
122 struct hlist_node *node;
123 struct hlist_head *head;
124 unsigned int h;
125
126 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
127 head = &net->ipv4.fib_table_hash[h];
128 hlist_for_each_entry(tb, node, head, tb_hlist)
129 flushed += fib_table_flush(tb);
130 }
131
132 if (flushed)
133 rt_cache_flush(net, -1);
134 }
135
136 /*
137 * Find address type as if only "dev" was present in the system. If
138 * on_dev is NULL then all interfaces are taken into consideration.
139 */
140 static inline unsigned __inet_dev_addr_type(struct net *net,
141 const struct net_device *dev,
142 __be32 addr)
143 {
144 struct flowi4 fl4 = { .daddr = addr };
145 struct fib_result res;
146 unsigned ret = RTN_BROADCAST;
147 struct fib_table *local_table;
148
149 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
150 return RTN_BROADCAST;
151 if (ipv4_is_multicast(addr))
152 return RTN_MULTICAST;
153
154 #ifdef CONFIG_IP_MULTIPLE_TABLES
155 res.r = NULL;
156 #endif
157
158 local_table = fib_get_table(net, RT_TABLE_LOCAL);
159 if (local_table) {
160 ret = RTN_UNICAST;
161 rcu_read_lock();
162 if (!fib_table_lookup(local_table, &fl4, &res, FIB_LOOKUP_NOREF)) {
163 if (!dev || dev == res.fi->fib_dev)
164 ret = res.type;
165 }
166 rcu_read_unlock();
167 }
168 return ret;
169 }
170
171 unsigned int inet_addr_type(struct net *net, __be32 addr)
172 {
173 return __inet_dev_addr_type(net, NULL, addr);
174 }
175 EXPORT_SYMBOL(inet_addr_type);
176
177 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
178 __be32 addr)
179 {
180 return __inet_dev_addr_type(net, dev, addr);
181 }
182 EXPORT_SYMBOL(inet_dev_addr_type);
183
184 /* Given (packet source, input interface) and optional (dst, oif, tos):
185 * - (main) check, that source is valid i.e. not broadcast or our local
186 * address.
187 * - figure out what "logical" interface this packet arrived
188 * and calculate "specific destination" address.
189 * - check, that packet arrived from expected physical interface.
190 * called with rcu_read_lock()
191 */
192 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, u8 tos,
193 int oif, struct net_device *dev, __be32 *spec_dst,
194 u32 *itag)
195 {
196 struct in_device *in_dev;
197 struct flowi4 fl4;
198 struct fib_result res;
199 int no_addr, rpf, accept_local;
200 bool dev_match;
201 int ret;
202 struct net *net;
203
204 fl4.flowi4_oif = 0;
205 fl4.flowi4_iif = oif;
206 fl4.daddr = src;
207 fl4.saddr = dst;
208 fl4.flowi4_tos = tos;
209 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
210
211 no_addr = rpf = accept_local = 0;
212 in_dev = __in_dev_get_rcu(dev);
213 if (in_dev) {
214 no_addr = in_dev->ifa_list == NULL;
215
216 /* Ignore rp_filter for packets protected by IPsec. */
217 rpf = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(in_dev);
218
219 accept_local = IN_DEV_ACCEPT_LOCAL(in_dev);
220 fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0;
221 }
222
223 if (in_dev == NULL)
224 goto e_inval;
225
226 net = dev_net(dev);
227 if (fib_lookup(net, &fl4, &res))
228 goto last_resort;
229 if (res.type != RTN_UNICAST) {
230 if (res.type != RTN_LOCAL || !accept_local)
231 goto e_inval;
232 }
233 *spec_dst = FIB_RES_PREFSRC(net, res);
234 fib_combine_itag(itag, &res);
235 dev_match = false;
236
237 #ifdef CONFIG_IP_ROUTE_MULTIPATH
238 for (ret = 0; ret < res.fi->fib_nhs; ret++) {
239 struct fib_nh *nh = &res.fi->fib_nh[ret];
240
241 if (nh->nh_dev == dev) {
242 dev_match = true;
243 break;
244 }
245 }
246 #else
247 if (FIB_RES_DEV(res) == dev)
248 dev_match = true;
249 #endif
250 if (dev_match) {
251 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
252 return ret;
253 }
254 if (no_addr)
255 goto last_resort;
256 if (rpf == 1)
257 goto e_rpf;
258 fl4.flowi4_oif = dev->ifindex;
259
260 ret = 0;
261 if (fib_lookup(net, &fl4, &res) == 0) {
262 if (res.type == RTN_UNICAST) {
263 *spec_dst = FIB_RES_PREFSRC(net, res);
264 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
265 }
266 }
267 return ret;
268
269 last_resort:
270 if (rpf)
271 goto e_rpf;
272 *spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
273 *itag = 0;
274 return 0;
275
276 e_inval:
277 return -EINVAL;
278 e_rpf:
279 return -EXDEV;
280 }
281
282 static inline __be32 sk_extract_addr(struct sockaddr *addr)
283 {
284 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
285 }
286
287 static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
288 {
289 struct nlattr *nla;
290
291 nla = (struct nlattr *) ((char *) mx + len);
292 nla->nla_type = type;
293 nla->nla_len = nla_attr_size(4);
294 *(u32 *) nla_data(nla) = value;
295
296 return len + nla_total_size(4);
297 }
298
299 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
300 struct fib_config *cfg)
301 {
302 __be32 addr;
303 int plen;
304
305 memset(cfg, 0, sizeof(*cfg));
306 cfg->fc_nlinfo.nl_net = net;
307
308 if (rt->rt_dst.sa_family != AF_INET)
309 return -EAFNOSUPPORT;
310
311 /*
312 * Check mask for validity:
313 * a) it must be contiguous.
314 * b) destination must have all host bits clear.
315 * c) if application forgot to set correct family (AF_INET),
316 * reject request unless it is absolutely clear i.e.
317 * both family and mask are zero.
318 */
319 plen = 32;
320 addr = sk_extract_addr(&rt->rt_dst);
321 if (!(rt->rt_flags & RTF_HOST)) {
322 __be32 mask = sk_extract_addr(&rt->rt_genmask);
323
324 if (rt->rt_genmask.sa_family != AF_INET) {
325 if (mask || rt->rt_genmask.sa_family)
326 return -EAFNOSUPPORT;
327 }
328
329 if (bad_mask(mask, addr))
330 return -EINVAL;
331
332 plen = inet_mask_len(mask);
333 }
334
335 cfg->fc_dst_len = plen;
336 cfg->fc_dst = addr;
337
338 if (cmd != SIOCDELRT) {
339 cfg->fc_nlflags = NLM_F_CREATE;
340 cfg->fc_protocol = RTPROT_BOOT;
341 }
342
343 if (rt->rt_metric)
344 cfg->fc_priority = rt->rt_metric - 1;
345
346 if (rt->rt_flags & RTF_REJECT) {
347 cfg->fc_scope = RT_SCOPE_HOST;
348 cfg->fc_type = RTN_UNREACHABLE;
349 return 0;
350 }
351
352 cfg->fc_scope = RT_SCOPE_NOWHERE;
353 cfg->fc_type = RTN_UNICAST;
354
355 if (rt->rt_dev) {
356 char *colon;
357 struct net_device *dev;
358 char devname[IFNAMSIZ];
359
360 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
361 return -EFAULT;
362
363 devname[IFNAMSIZ-1] = 0;
364 colon = strchr(devname, ':');
365 if (colon)
366 *colon = 0;
367 dev = __dev_get_by_name(net, devname);
368 if (!dev)
369 return -ENODEV;
370 cfg->fc_oif = dev->ifindex;
371 if (colon) {
372 struct in_ifaddr *ifa;
373 struct in_device *in_dev = __in_dev_get_rtnl(dev);
374 if (!in_dev)
375 return -ENODEV;
376 *colon = ':';
377 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
378 if (strcmp(ifa->ifa_label, devname) == 0)
379 break;
380 if (ifa == NULL)
381 return -ENODEV;
382 cfg->fc_prefsrc = ifa->ifa_local;
383 }
384 }
385
386 addr = sk_extract_addr(&rt->rt_gateway);
387 if (rt->rt_gateway.sa_family == AF_INET && addr) {
388 cfg->fc_gw = addr;
389 if (rt->rt_flags & RTF_GATEWAY &&
390 inet_addr_type(net, addr) == RTN_UNICAST)
391 cfg->fc_scope = RT_SCOPE_UNIVERSE;
392 }
393
394 if (cmd == SIOCDELRT)
395 return 0;
396
397 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
398 return -EINVAL;
399
400 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
401 cfg->fc_scope = RT_SCOPE_LINK;
402
403 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
404 struct nlattr *mx;
405 int len = 0;
406
407 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
408 if (mx == NULL)
409 return -ENOMEM;
410
411 if (rt->rt_flags & RTF_MTU)
412 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
413
414 if (rt->rt_flags & RTF_WINDOW)
415 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
416
417 if (rt->rt_flags & RTF_IRTT)
418 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
419
420 cfg->fc_mx = mx;
421 cfg->fc_mx_len = len;
422 }
423
424 return 0;
425 }
426
427 /*
428 * Handle IP routing ioctl calls.
429 * These are used to manipulate the routing tables
430 */
431 int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
432 {
433 struct fib_config cfg;
434 struct rtentry rt;
435 int err;
436
437 switch (cmd) {
438 case SIOCADDRT: /* Add a route */
439 case SIOCDELRT: /* Delete a route */
440 if (!capable(CAP_NET_ADMIN))
441 return -EPERM;
442
443 if (copy_from_user(&rt, arg, sizeof(rt)))
444 return -EFAULT;
445
446 rtnl_lock();
447 err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
448 if (err == 0) {
449 struct fib_table *tb;
450
451 if (cmd == SIOCDELRT) {
452 tb = fib_get_table(net, cfg.fc_table);
453 if (tb)
454 err = fib_table_delete(tb, &cfg);
455 else
456 err = -ESRCH;
457 } else {
458 tb = fib_new_table(net, cfg.fc_table);
459 if (tb)
460 err = fib_table_insert(tb, &cfg);
461 else
462 err = -ENOBUFS;
463 }
464
465 /* allocated by rtentry_to_fib_config() */
466 kfree(cfg.fc_mx);
467 }
468 rtnl_unlock();
469 return err;
470 }
471 return -EINVAL;
472 }
473
474 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
475 [RTA_DST] = { .type = NLA_U32 },
476 [RTA_SRC] = { .type = NLA_U32 },
477 [RTA_IIF] = { .type = NLA_U32 },
478 [RTA_OIF] = { .type = NLA_U32 },
479 [RTA_GATEWAY] = { .type = NLA_U32 },
480 [RTA_PRIORITY] = { .type = NLA_U32 },
481 [RTA_PREFSRC] = { .type = NLA_U32 },
482 [RTA_METRICS] = { .type = NLA_NESTED },
483 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
484 [RTA_FLOW] = { .type = NLA_U32 },
485 };
486
487 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
488 struct nlmsghdr *nlh, struct fib_config *cfg)
489 {
490 struct nlattr *attr;
491 int err, remaining;
492 struct rtmsg *rtm;
493
494 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
495 if (err < 0)
496 goto errout;
497
498 memset(cfg, 0, sizeof(*cfg));
499
500 rtm = nlmsg_data(nlh);
501 cfg->fc_dst_len = rtm->rtm_dst_len;
502 cfg->fc_tos = rtm->rtm_tos;
503 cfg->fc_table = rtm->rtm_table;
504 cfg->fc_protocol = rtm->rtm_protocol;
505 cfg->fc_scope = rtm->rtm_scope;
506 cfg->fc_type = rtm->rtm_type;
507 cfg->fc_flags = rtm->rtm_flags;
508 cfg->fc_nlflags = nlh->nlmsg_flags;
509
510 cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid;
511 cfg->fc_nlinfo.nlh = nlh;
512 cfg->fc_nlinfo.nl_net = net;
513
514 if (cfg->fc_type > RTN_MAX) {
515 err = -EINVAL;
516 goto errout;
517 }
518
519 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
520 switch (nla_type(attr)) {
521 case RTA_DST:
522 cfg->fc_dst = nla_get_be32(attr);
523 break;
524 case RTA_OIF:
525 cfg->fc_oif = nla_get_u32(attr);
526 break;
527 case RTA_GATEWAY:
528 cfg->fc_gw = nla_get_be32(attr);
529 break;
530 case RTA_PRIORITY:
531 cfg->fc_priority = nla_get_u32(attr);
532 break;
533 case RTA_PREFSRC:
534 cfg->fc_prefsrc = nla_get_be32(attr);
535 break;
536 case RTA_METRICS:
537 cfg->fc_mx = nla_data(attr);
538 cfg->fc_mx_len = nla_len(attr);
539 break;
540 case RTA_MULTIPATH:
541 cfg->fc_mp = nla_data(attr);
542 cfg->fc_mp_len = nla_len(attr);
543 break;
544 case RTA_FLOW:
545 cfg->fc_flow = nla_get_u32(attr);
546 break;
547 case RTA_TABLE:
548 cfg->fc_table = nla_get_u32(attr);
549 break;
550 }
551 }
552
553 return 0;
554 errout:
555 return err;
556 }
557
558 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
559 {
560 struct net *net = sock_net(skb->sk);
561 struct fib_config cfg;
562 struct fib_table *tb;
563 int err;
564
565 err = rtm_to_fib_config(net, skb, nlh, &cfg);
566 if (err < 0)
567 goto errout;
568
569 tb = fib_get_table(net, cfg.fc_table);
570 if (tb == NULL) {
571 err = -ESRCH;
572 goto errout;
573 }
574
575 err = fib_table_delete(tb, &cfg);
576 errout:
577 return err;
578 }
579
580 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
581 {
582 struct net *net = sock_net(skb->sk);
583 struct fib_config cfg;
584 struct fib_table *tb;
585 int err;
586
587 err = rtm_to_fib_config(net, skb, nlh, &cfg);
588 if (err < 0)
589 goto errout;
590
591 tb = fib_new_table(net, cfg.fc_table);
592 if (tb == NULL) {
593 err = -ENOBUFS;
594 goto errout;
595 }
596
597 err = fib_table_insert(tb, &cfg);
598 errout:
599 return err;
600 }
601
602 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
603 {
604 struct net *net = sock_net(skb->sk);
605 unsigned int h, s_h;
606 unsigned int e = 0, s_e;
607 struct fib_table *tb;
608 struct hlist_node *node;
609 struct hlist_head *head;
610 int dumped = 0;
611
612 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
613 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
614 return ip_rt_dump(skb, cb);
615
616 s_h = cb->args[0];
617 s_e = cb->args[1];
618
619 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
620 e = 0;
621 head = &net->ipv4.fib_table_hash[h];
622 hlist_for_each_entry(tb, node, head, tb_hlist) {
623 if (e < s_e)
624 goto next;
625 if (dumped)
626 memset(&cb->args[2], 0, sizeof(cb->args) -
627 2 * sizeof(cb->args[0]));
628 if (fib_table_dump(tb, skb, cb) < 0)
629 goto out;
630 dumped = 1;
631 next:
632 e++;
633 }
634 }
635 out:
636 cb->args[1] = e;
637 cb->args[0] = h;
638
639 return skb->len;
640 }
641
642 /* Prepare and feed intra-kernel routing request.
643 * Really, it should be netlink message, but :-( netlink
644 * can be not configured, so that we feed it directly
645 * to fib engine. It is legal, because all events occur
646 * only when netlink is already locked.
647 */
648 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
649 {
650 struct net *net = dev_net(ifa->ifa_dev->dev);
651 struct fib_table *tb;
652 struct fib_config cfg = {
653 .fc_protocol = RTPROT_KERNEL,
654 .fc_type = type,
655 .fc_dst = dst,
656 .fc_dst_len = dst_len,
657 .fc_prefsrc = ifa->ifa_local,
658 .fc_oif = ifa->ifa_dev->dev->ifindex,
659 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
660 .fc_nlinfo = {
661 .nl_net = net,
662 },
663 };
664
665 if (type == RTN_UNICAST)
666 tb = fib_new_table(net, RT_TABLE_MAIN);
667 else
668 tb = fib_new_table(net, RT_TABLE_LOCAL);
669
670 if (tb == NULL)
671 return;
672
673 cfg.fc_table = tb->tb_id;
674
675 if (type != RTN_LOCAL)
676 cfg.fc_scope = RT_SCOPE_LINK;
677 else
678 cfg.fc_scope = RT_SCOPE_HOST;
679
680 if (cmd == RTM_NEWROUTE)
681 fib_table_insert(tb, &cfg);
682 else
683 fib_table_delete(tb, &cfg);
684 }
685
686 void fib_add_ifaddr(struct in_ifaddr *ifa)
687 {
688 struct in_device *in_dev = ifa->ifa_dev;
689 struct net_device *dev = in_dev->dev;
690 struct in_ifaddr *prim = ifa;
691 __be32 mask = ifa->ifa_mask;
692 __be32 addr = ifa->ifa_local;
693 __be32 prefix = ifa->ifa_address & mask;
694
695 if (ifa->ifa_flags & IFA_F_SECONDARY) {
696 prim = inet_ifa_byprefix(in_dev, prefix, mask);
697 if (prim == NULL) {
698 printk(KERN_WARNING "fib_add_ifaddr: bug: prim == NULL\n");
699 return;
700 }
701 }
702
703 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
704
705 if (!(dev->flags & IFF_UP))
706 return;
707
708 /* Add broadcast address, if it is explicitly assigned. */
709 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
710 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
711
712 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
713 (prefix != addr || ifa->ifa_prefixlen < 32)) {
714 fib_magic(RTM_NEWROUTE,
715 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
716 prefix, ifa->ifa_prefixlen, prim);
717
718 /* Add network specific broadcasts, when it takes a sense */
719 if (ifa->ifa_prefixlen < 31) {
720 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
721 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
722 32, prim);
723 }
724 }
725 }
726
727 /* Delete primary or secondary address.
728 * Optionally, on secondary address promotion consider the addresses
729 * from subnet iprim as deleted, even if they are in device list.
730 * In this case the secondary ifa can be in device list.
731 */
732 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
733 {
734 struct in_device *in_dev = ifa->ifa_dev;
735 struct net_device *dev = in_dev->dev;
736 struct in_ifaddr *ifa1;
737 struct in_ifaddr *prim = ifa, *prim1 = NULL;
738 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
739 __be32 any = ifa->ifa_address & ifa->ifa_mask;
740 #define LOCAL_OK 1
741 #define BRD_OK 2
742 #define BRD0_OK 4
743 #define BRD1_OK 8
744 unsigned ok = 0;
745 int subnet = 0; /* Primary network */
746 int gone = 1; /* Address is missing */
747 int same_prefsrc = 0; /* Another primary with same IP */
748
749 if (ifa->ifa_flags & IFA_F_SECONDARY) {
750 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
751 if (prim == NULL) {
752 printk(KERN_WARNING "fib_del_ifaddr: bug: prim == NULL\n");
753 return;
754 }
755 if (iprim && iprim != prim) {
756 printk(KERN_WARNING "fib_del_ifaddr: bug: iprim != prim\n");
757 return;
758 }
759 } else if (!ipv4_is_zeronet(any) &&
760 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
761 fib_magic(RTM_DELROUTE,
762 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
763 any, ifa->ifa_prefixlen, prim);
764 subnet = 1;
765 }
766
767 /* Deletion is more complicated than add.
768 * We should take care of not to delete too much :-)
769 *
770 * Scan address list to be sure that addresses are really gone.
771 */
772
773 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
774 if (ifa1 == ifa) {
775 /* promotion, keep the IP */
776 gone = 0;
777 continue;
778 }
779 /* Ignore IFAs from our subnet */
780 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
781 inet_ifa_match(ifa1->ifa_address, iprim))
782 continue;
783
784 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
785 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
786 /* Another address from our subnet? */
787 if (ifa1->ifa_mask == prim->ifa_mask &&
788 inet_ifa_match(ifa1->ifa_address, prim))
789 prim1 = prim;
790 else {
791 /* We reached the secondaries, so
792 * same_prefsrc should be determined.
793 */
794 if (!same_prefsrc)
795 continue;
796 /* Search new prim1 if ifa1 is not
797 * using the current prim1
798 */
799 if (!prim1 ||
800 ifa1->ifa_mask != prim1->ifa_mask ||
801 !inet_ifa_match(ifa1->ifa_address, prim1))
802 prim1 = inet_ifa_byprefix(in_dev,
803 ifa1->ifa_address,
804 ifa1->ifa_mask);
805 if (!prim1)
806 continue;
807 if (prim1->ifa_local != prim->ifa_local)
808 continue;
809 }
810 } else {
811 if (prim->ifa_local != ifa1->ifa_local)
812 continue;
813 prim1 = ifa1;
814 if (prim != prim1)
815 same_prefsrc = 1;
816 }
817 if (ifa->ifa_local == ifa1->ifa_local)
818 ok |= LOCAL_OK;
819 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
820 ok |= BRD_OK;
821 if (brd == ifa1->ifa_broadcast)
822 ok |= BRD1_OK;
823 if (any == ifa1->ifa_broadcast)
824 ok |= BRD0_OK;
825 /* primary has network specific broadcasts */
826 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
827 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
828 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
829
830 if (!ipv4_is_zeronet(any1)) {
831 if (ifa->ifa_broadcast == brd1 ||
832 ifa->ifa_broadcast == any1)
833 ok |= BRD_OK;
834 if (brd == brd1 || brd == any1)
835 ok |= BRD1_OK;
836 if (any == brd1 || any == any1)
837 ok |= BRD0_OK;
838 }
839 }
840 }
841
842 if (!(ok & BRD_OK))
843 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
844 if (subnet && ifa->ifa_prefixlen < 31) {
845 if (!(ok & BRD1_OK))
846 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
847 if (!(ok & BRD0_OK))
848 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
849 }
850 if (!(ok & LOCAL_OK)) {
851 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
852
853 /* Check, that this local address finally disappeared. */
854 if (gone &&
855 inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) {
856 /* And the last, but not the least thing.
857 * We must flush stray FIB entries.
858 *
859 * First of all, we scan fib_info list searching
860 * for stray nexthop entries, then ignite fib_flush.
861 */
862 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
863 fib_flush(dev_net(dev));
864 }
865 }
866 #undef LOCAL_OK
867 #undef BRD_OK
868 #undef BRD0_OK
869 #undef BRD1_OK
870 }
871
872 static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb)
873 {
874
875 struct fib_result res;
876 struct flowi4 fl4 = {
877 .flowi4_mark = frn->fl_mark,
878 .daddr = frn->fl_addr,
879 .flowi4_tos = frn->fl_tos,
880 .flowi4_scope = frn->fl_scope,
881 };
882
883 #ifdef CONFIG_IP_MULTIPLE_TABLES
884 res.r = NULL;
885 #endif
886
887 frn->err = -ENOENT;
888 if (tb) {
889 local_bh_disable();
890
891 frn->tb_id = tb->tb_id;
892 rcu_read_lock();
893 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
894
895 if (!frn->err) {
896 frn->prefixlen = res.prefixlen;
897 frn->nh_sel = res.nh_sel;
898 frn->type = res.type;
899 frn->scope = res.scope;
900 }
901 rcu_read_unlock();
902 local_bh_enable();
903 }
904 }
905
906 static void nl_fib_input(struct sk_buff *skb)
907 {
908 struct net *net;
909 struct fib_result_nl *frn;
910 struct nlmsghdr *nlh;
911 struct fib_table *tb;
912 u32 pid;
913
914 net = sock_net(skb->sk);
915 nlh = nlmsg_hdr(skb);
916 if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len ||
917 nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn)))
918 return;
919
920 skb = skb_clone(skb, GFP_KERNEL);
921 if (skb == NULL)
922 return;
923 nlh = nlmsg_hdr(skb);
924
925 frn = (struct fib_result_nl *) NLMSG_DATA(nlh);
926 tb = fib_get_table(net, frn->tb_id_in);
927
928 nl_fib_lookup(frn, tb);
929
930 pid = NETLINK_CB(skb).pid; /* pid of sending process */
931 NETLINK_CB(skb).pid = 0; /* from kernel */
932 NETLINK_CB(skb).dst_group = 0; /* unicast */
933 netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT);
934 }
935
936 static int __net_init nl_fib_lookup_init(struct net *net)
937 {
938 struct sock *sk;
939 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0,
940 nl_fib_input, NULL, THIS_MODULE);
941 if (sk == NULL)
942 return -EAFNOSUPPORT;
943 net->ipv4.fibnl = sk;
944 return 0;
945 }
946
947 static void nl_fib_lookup_exit(struct net *net)
948 {
949 netlink_kernel_release(net->ipv4.fibnl);
950 net->ipv4.fibnl = NULL;
951 }
952
953 static void fib_disable_ip(struct net_device *dev, int force, int delay)
954 {
955 if (fib_sync_down_dev(dev, force))
956 fib_flush(dev_net(dev));
957 rt_cache_flush(dev_net(dev), delay);
958 arp_ifdown(dev);
959 }
960
961 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
962 {
963 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
964 struct net_device *dev = ifa->ifa_dev->dev;
965 struct net *net = dev_net(dev);
966
967 switch (event) {
968 case NETDEV_UP:
969 fib_add_ifaddr(ifa);
970 #ifdef CONFIG_IP_ROUTE_MULTIPATH
971 fib_sync_up(dev);
972 #endif
973 atomic_inc(&net->ipv4.dev_addr_genid);
974 rt_cache_flush(dev_net(dev), -1);
975 break;
976 case NETDEV_DOWN:
977 fib_del_ifaddr(ifa, NULL);
978 atomic_inc(&net->ipv4.dev_addr_genid);
979 if (ifa->ifa_dev->ifa_list == NULL) {
980 /* Last address was deleted from this interface.
981 * Disable IP.
982 */
983 fib_disable_ip(dev, 1, 0);
984 } else {
985 rt_cache_flush(dev_net(dev), -1);
986 }
987 break;
988 }
989 return NOTIFY_DONE;
990 }
991
992 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
993 {
994 struct net_device *dev = ptr;
995 struct in_device *in_dev = __in_dev_get_rtnl(dev);
996 struct net *net = dev_net(dev);
997
998 if (event == NETDEV_UNREGISTER) {
999 fib_disable_ip(dev, 2, -1);
1000 return NOTIFY_DONE;
1001 }
1002
1003 if (!in_dev)
1004 return NOTIFY_DONE;
1005
1006 switch (event) {
1007 case NETDEV_UP:
1008 for_ifa(in_dev) {
1009 fib_add_ifaddr(ifa);
1010 } endfor_ifa(in_dev);
1011 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1012 fib_sync_up(dev);
1013 #endif
1014 atomic_inc(&net->ipv4.dev_addr_genid);
1015 rt_cache_flush(dev_net(dev), -1);
1016 break;
1017 case NETDEV_DOWN:
1018 fib_disable_ip(dev, 0, 0);
1019 break;
1020 case NETDEV_CHANGEMTU:
1021 case NETDEV_CHANGE:
1022 rt_cache_flush(dev_net(dev), 0);
1023 break;
1024 case NETDEV_UNREGISTER_BATCH:
1025 /* The batch unregister is only called on the first
1026 * device in the list of devices being unregistered.
1027 * Therefore we should not pass dev_net(dev) in here.
1028 */
1029 rt_cache_flush_batch(NULL);
1030 break;
1031 }
1032 return NOTIFY_DONE;
1033 }
1034
1035 static struct notifier_block fib_inetaddr_notifier = {
1036 .notifier_call = fib_inetaddr_event,
1037 };
1038
1039 static struct notifier_block fib_netdev_notifier = {
1040 .notifier_call = fib_netdev_event,
1041 };
1042
1043 static int __net_init ip_fib_net_init(struct net *net)
1044 {
1045 int err;
1046 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1047
1048 /* Avoid false sharing : Use at least a full cache line */
1049 size = max_t(size_t, size, L1_CACHE_BYTES);
1050
1051 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1052 if (net->ipv4.fib_table_hash == NULL)
1053 return -ENOMEM;
1054
1055 err = fib4_rules_init(net);
1056 if (err < 0)
1057 goto fail;
1058 return 0;
1059
1060 fail:
1061 kfree(net->ipv4.fib_table_hash);
1062 return err;
1063 }
1064
1065 static void ip_fib_net_exit(struct net *net)
1066 {
1067 unsigned int i;
1068
1069 #ifdef CONFIG_IP_MULTIPLE_TABLES
1070 fib4_rules_exit(net);
1071 #endif
1072
1073 rtnl_lock();
1074 for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1075 struct fib_table *tb;
1076 struct hlist_head *head;
1077 struct hlist_node *node, *tmp;
1078
1079 head = &net->ipv4.fib_table_hash[i];
1080 hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) {
1081 hlist_del(node);
1082 fib_table_flush(tb);
1083 fib_free_table(tb);
1084 }
1085 }
1086 rtnl_unlock();
1087 kfree(net->ipv4.fib_table_hash);
1088 }
1089
1090 static int __net_init fib_net_init(struct net *net)
1091 {
1092 int error;
1093
1094 error = ip_fib_net_init(net);
1095 if (error < 0)
1096 goto out;
1097 error = nl_fib_lookup_init(net);
1098 if (error < 0)
1099 goto out_nlfl;
1100 error = fib_proc_init(net);
1101 if (error < 0)
1102 goto out_proc;
1103 out:
1104 return error;
1105
1106 out_proc:
1107 nl_fib_lookup_exit(net);
1108 out_nlfl:
1109 ip_fib_net_exit(net);
1110 goto out;
1111 }
1112
1113 static void __net_exit fib_net_exit(struct net *net)
1114 {
1115 fib_proc_exit(net);
1116 nl_fib_lookup_exit(net);
1117 ip_fib_net_exit(net);
1118 }
1119
1120 static struct pernet_operations fib_net_ops = {
1121 .init = fib_net_init,
1122 .exit = fib_net_exit,
1123 };
1124
1125 void __init ip_fib_init(void)
1126 {
1127 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1128 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1129 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1130
1131 register_pernet_subsys(&fib_net_ops);
1132 register_netdevice_notifier(&fib_netdev_notifier);
1133 register_inetaddr_notifier(&fib_inetaddr_notifier);
1134
1135 fib_trie_init();
1136 }
linux-next