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Linux 3.8-rc7
[cris-mirror.git] / net / ipv4 / fib_frontend.c
blob5cd75e2dab2c17377d7250680c6b32717fe9cce9
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 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
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 struct fib_table *fib_get_table(struct net *net, u32 id)
113 {
114 struct fib_table *tb;
115 struct hlist_node *node;
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 rcu_read_lock();
124 head = &net->ipv4.fib_table_hash[h];
125 hlist_for_each_entry_rcu(tb, node, head, tb_hlist) {
126 if (tb->tb_id == id) {
127 rcu_read_unlock();
128 return tb;
129 }
130 }
131 rcu_read_unlock();
132 return NULL;
133 }
134 #endif /* CONFIG_IP_MULTIPLE_TABLES */
135
136 static void fib_flush(struct net *net)
137 {
138 int flushed = 0;
139 struct fib_table *tb;
140 struct hlist_node *node;
141 struct hlist_head *head;
142 unsigned int h;
143
144 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
145 head = &net->ipv4.fib_table_hash[h];
146 hlist_for_each_entry(tb, node, head, tb_hlist)
147 flushed += fib_table_flush(tb);
148 }
149
150 if (flushed)
151 rt_cache_flush(net);
152 }
153
154 /*
155 * Find address type as if only "dev" was present in the system. If
156 * on_dev is NULL then all interfaces are taken into consideration.
157 */
158 static inline unsigned int __inet_dev_addr_type(struct net *net,
159 const struct net_device *dev,
160 __be32 addr)
161 {
162 struct flowi4 fl4 = { .daddr = addr };
163 struct fib_result res;
164 unsigned int ret = RTN_BROADCAST;
165 struct fib_table *local_table;
166
167 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
168 return RTN_BROADCAST;
169 if (ipv4_is_multicast(addr))
170 return RTN_MULTICAST;
171
172 local_table = fib_get_table(net, RT_TABLE_LOCAL);
173 if (local_table) {
174 ret = RTN_UNICAST;
175 rcu_read_lock();
176 if (!fib_table_lookup(local_table, &fl4, &res, FIB_LOOKUP_NOREF)) {
177 if (!dev || dev == res.fi->fib_dev)
178 ret = res.type;
179 }
180 rcu_read_unlock();
181 }
182 return ret;
183 }
184
185 unsigned int inet_addr_type(struct net *net, __be32 addr)
186 {
187 return __inet_dev_addr_type(net, NULL, addr);
188 }
189 EXPORT_SYMBOL(inet_addr_type);
190
191 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
192 __be32 addr)
193 {
194 return __inet_dev_addr_type(net, dev, addr);
195 }
196 EXPORT_SYMBOL(inet_dev_addr_type);
197
198 __be32 fib_compute_spec_dst(struct sk_buff *skb)
199 {
200 struct net_device *dev = skb->dev;
201 struct in_device *in_dev;
202 struct fib_result res;
203 struct rtable *rt;
204 struct flowi4 fl4;
205 struct net *net;
206 int scope;
207
208 rt = skb_rtable(skb);
209 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
210 RTCF_LOCAL)
211 return ip_hdr(skb)->daddr;
212
213 in_dev = __in_dev_get_rcu(dev);
214 BUG_ON(!in_dev);
215
216 net = dev_net(dev);
217
218 scope = RT_SCOPE_UNIVERSE;
219 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
220 fl4.flowi4_oif = 0;
221 fl4.flowi4_iif = LOOPBACK_IFINDEX;
222 fl4.daddr = ip_hdr(skb)->saddr;
223 fl4.saddr = 0;
224 fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos);
225 fl4.flowi4_scope = scope;
226 fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0;
227 if (!fib_lookup(net, &fl4, &res))
228 return FIB_RES_PREFSRC(net, res);
229 } else {
230 scope = RT_SCOPE_LINK;
231 }
232
233 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
234 }
235
236 /* Given (packet source, input interface) and optional (dst, oif, tos):
237 * - (main) check, that source is valid i.e. not broadcast or our local
238 * address.
239 * - figure out what "logical" interface this packet arrived
240 * and calculate "specific destination" address.
241 * - check, that packet arrived from expected physical interface.
242 * called with rcu_read_lock()
243 */
244 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
245 u8 tos, int oif, struct net_device *dev,
246 int rpf, struct in_device *idev, u32 *itag)
247 {
248 int ret, no_addr, accept_local;
249 struct fib_result res;
250 struct flowi4 fl4;
251 struct net *net;
252 bool dev_match;
253
254 fl4.flowi4_oif = 0;
255 fl4.flowi4_iif = oif;
256 fl4.daddr = src;
257 fl4.saddr = dst;
258 fl4.flowi4_tos = tos;
259 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
260
261 no_addr = idev->ifa_list == NULL;
262
263 accept_local = IN_DEV_ACCEPT_LOCAL(idev);
264 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
265
266 net = dev_net(dev);
267 if (fib_lookup(net, &fl4, &res))
268 goto last_resort;
269 if (res.type != RTN_UNICAST) {
270 if (res.type != RTN_LOCAL || !accept_local)
271 goto e_inval;
272 }
273 fib_combine_itag(itag, &res);
274 dev_match = false;
275
276 #ifdef CONFIG_IP_ROUTE_MULTIPATH
277 for (ret = 0; ret < res.fi->fib_nhs; ret++) {
278 struct fib_nh *nh = &res.fi->fib_nh[ret];
279
280 if (nh->nh_dev == dev) {
281 dev_match = true;
282 break;
283 }
284 }
285 #else
286 if (FIB_RES_DEV(res) == dev)
287 dev_match = true;
288 #endif
289 if (dev_match) {
290 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
291 return ret;
292 }
293 if (no_addr)
294 goto last_resort;
295 if (rpf == 1)
296 goto e_rpf;
297 fl4.flowi4_oif = dev->ifindex;
298
299 ret = 0;
300 if (fib_lookup(net, &fl4, &res) == 0) {
301 if (res.type == RTN_UNICAST)
302 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
303 }
304 return ret;
305
306 last_resort:
307 if (rpf)
308 goto e_rpf;
309 *itag = 0;
310 return 0;
311
312 e_inval:
313 return -EINVAL;
314 e_rpf:
315 return -EXDEV;
316 }
317
318 /* Ignore rp_filter for packets protected by IPsec. */
319 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
320 u8 tos, int oif, struct net_device *dev,
321 struct in_device *idev, u32 *itag)
322 {
323 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
324
325 if (!r && !fib_num_tclassid_users(dev_net(dev)) &&
326 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
327 *itag = 0;
328 return 0;
329 }
330 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
331 }
332
333 static inline __be32 sk_extract_addr(struct sockaddr *addr)
334 {
335 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
336 }
337
338 static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
339 {
340 struct nlattr *nla;
341
342 nla = (struct nlattr *) ((char *) mx + len);
343 nla->nla_type = type;
344 nla->nla_len = nla_attr_size(4);
345 *(u32 *) nla_data(nla) = value;
346
347 return len + nla_total_size(4);
348 }
349
350 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
351 struct fib_config *cfg)
352 {
353 __be32 addr;
354 int plen;
355
356 memset(cfg, 0, sizeof(*cfg));
357 cfg->fc_nlinfo.nl_net = net;
358
359 if (rt->rt_dst.sa_family != AF_INET)
360 return -EAFNOSUPPORT;
361
362 /*
363 * Check mask for validity:
364 * a) it must be contiguous.
365 * b) destination must have all host bits clear.
366 * c) if application forgot to set correct family (AF_INET),
367 * reject request unless it is absolutely clear i.e.
368 * both family and mask are zero.
369 */
370 plen = 32;
371 addr = sk_extract_addr(&rt->rt_dst);
372 if (!(rt->rt_flags & RTF_HOST)) {
373 __be32 mask = sk_extract_addr(&rt->rt_genmask);
374
375 if (rt->rt_genmask.sa_family != AF_INET) {
376 if (mask || rt->rt_genmask.sa_family)
377 return -EAFNOSUPPORT;
378 }
379
380 if (bad_mask(mask, addr))
381 return -EINVAL;
382
383 plen = inet_mask_len(mask);
384 }
385
386 cfg->fc_dst_len = plen;
387 cfg->fc_dst = addr;
388
389 if (cmd != SIOCDELRT) {
390 cfg->fc_nlflags = NLM_F_CREATE;
391 cfg->fc_protocol = RTPROT_BOOT;
392 }
393
394 if (rt->rt_metric)
395 cfg->fc_priority = rt->rt_metric - 1;
396
397 if (rt->rt_flags & RTF_REJECT) {
398 cfg->fc_scope = RT_SCOPE_HOST;
399 cfg->fc_type = RTN_UNREACHABLE;
400 return 0;
401 }
402
403 cfg->fc_scope = RT_SCOPE_NOWHERE;
404 cfg->fc_type = RTN_UNICAST;
405
406 if (rt->rt_dev) {
407 char *colon;
408 struct net_device *dev;
409 char devname[IFNAMSIZ];
410
411 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
412 return -EFAULT;
413
414 devname[IFNAMSIZ-1] = 0;
415 colon = strchr(devname, ':');
416 if (colon)
417 *colon = 0;
418 dev = __dev_get_by_name(net, devname);
419 if (!dev)
420 return -ENODEV;
421 cfg->fc_oif = dev->ifindex;
422 if (colon) {
423 struct in_ifaddr *ifa;
424 struct in_device *in_dev = __in_dev_get_rtnl(dev);
425 if (!in_dev)
426 return -ENODEV;
427 *colon = ':';
428 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
429 if (strcmp(ifa->ifa_label, devname) == 0)
430 break;
431 if (ifa == NULL)
432 return -ENODEV;
433 cfg->fc_prefsrc = ifa->ifa_local;
434 }
435 }
436
437 addr = sk_extract_addr(&rt->rt_gateway);
438 if (rt->rt_gateway.sa_family == AF_INET && addr) {
439 cfg->fc_gw = addr;
440 if (rt->rt_flags & RTF_GATEWAY &&
441 inet_addr_type(net, addr) == RTN_UNICAST)
442 cfg->fc_scope = RT_SCOPE_UNIVERSE;
443 }
444
445 if (cmd == SIOCDELRT)
446 return 0;
447
448 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
449 return -EINVAL;
450
451 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
452 cfg->fc_scope = RT_SCOPE_LINK;
453
454 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
455 struct nlattr *mx;
456 int len = 0;
457
458 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
459 if (mx == NULL)
460 return -ENOMEM;
461
462 if (rt->rt_flags & RTF_MTU)
463 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
464
465 if (rt->rt_flags & RTF_WINDOW)
466 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
467
468 if (rt->rt_flags & RTF_IRTT)
469 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
470
471 cfg->fc_mx = mx;
472 cfg->fc_mx_len = len;
473 }
474
475 return 0;
476 }
477
478 /*
479 * Handle IP routing ioctl calls.
480 * These are used to manipulate the routing tables
481 */
482 int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
483 {
484 struct fib_config cfg;
485 struct rtentry rt;
486 int err;
487
488 switch (cmd) {
489 case SIOCADDRT: /* Add a route */
490 case SIOCDELRT: /* Delete a route */
491 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
492 return -EPERM;
493
494 if (copy_from_user(&rt, arg, sizeof(rt)))
495 return -EFAULT;
496
497 rtnl_lock();
498 err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
499 if (err == 0) {
500 struct fib_table *tb;
501
502 if (cmd == SIOCDELRT) {
503 tb = fib_get_table(net, cfg.fc_table);
504 if (tb)
505 err = fib_table_delete(tb, &cfg);
506 else
507 err = -ESRCH;
508 } else {
509 tb = fib_new_table(net, cfg.fc_table);
510 if (tb)
511 err = fib_table_insert(tb, &cfg);
512 else
513 err = -ENOBUFS;
514 }
515
516 /* allocated by rtentry_to_fib_config() */
517 kfree(cfg.fc_mx);
518 }
519 rtnl_unlock();
520 return err;
521 }
522 return -EINVAL;
523 }
524
525 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
526 [RTA_DST] = { .type = NLA_U32 },
527 [RTA_SRC] = { .type = NLA_U32 },
528 [RTA_IIF] = { .type = NLA_U32 },
529 [RTA_OIF] = { .type = NLA_U32 },
530 [RTA_GATEWAY] = { .type = NLA_U32 },
531 [RTA_PRIORITY] = { .type = NLA_U32 },
532 [RTA_PREFSRC] = { .type = NLA_U32 },
533 [RTA_METRICS] = { .type = NLA_NESTED },
534 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
535 [RTA_FLOW] = { .type = NLA_U32 },
536 };
537
538 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
539 struct nlmsghdr *nlh, struct fib_config *cfg)
540 {
541 struct nlattr *attr;
542 int err, remaining;
543 struct rtmsg *rtm;
544
545 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
546 if (err < 0)
547 goto errout;
548
549 memset(cfg, 0, sizeof(*cfg));
550
551 rtm = nlmsg_data(nlh);
552 cfg->fc_dst_len = rtm->rtm_dst_len;
553 cfg->fc_tos = rtm->rtm_tos;
554 cfg->fc_table = rtm->rtm_table;
555 cfg->fc_protocol = rtm->rtm_protocol;
556 cfg->fc_scope = rtm->rtm_scope;
557 cfg->fc_type = rtm->rtm_type;
558 cfg->fc_flags = rtm->rtm_flags;
559 cfg->fc_nlflags = nlh->nlmsg_flags;
560
561 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
562 cfg->fc_nlinfo.nlh = nlh;
563 cfg->fc_nlinfo.nl_net = net;
564
565 if (cfg->fc_type > RTN_MAX) {
566 err = -EINVAL;
567 goto errout;
568 }
569
570 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
571 switch (nla_type(attr)) {
572 case RTA_DST:
573 cfg->fc_dst = nla_get_be32(attr);
574 break;
575 case RTA_OIF:
576 cfg->fc_oif = nla_get_u32(attr);
577 break;
578 case RTA_GATEWAY:
579 cfg->fc_gw = nla_get_be32(attr);
580 break;
581 case RTA_PRIORITY:
582 cfg->fc_priority = nla_get_u32(attr);
583 break;
584 case RTA_PREFSRC:
585 cfg->fc_prefsrc = nla_get_be32(attr);
586 break;
587 case RTA_METRICS:
588 cfg->fc_mx = nla_data(attr);
589 cfg->fc_mx_len = nla_len(attr);
590 break;
591 case RTA_MULTIPATH:
592 cfg->fc_mp = nla_data(attr);
593 cfg->fc_mp_len = nla_len(attr);
594 break;
595 case RTA_FLOW:
596 cfg->fc_flow = nla_get_u32(attr);
597 break;
598 case RTA_TABLE:
599 cfg->fc_table = nla_get_u32(attr);
600 break;
601 }
602 }
603
604 return 0;
605 errout:
606 return err;
607 }
608
609 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
610 {
611 struct net *net = sock_net(skb->sk);
612 struct fib_config cfg;
613 struct fib_table *tb;
614 int err;
615
616 err = rtm_to_fib_config(net, skb, nlh, &cfg);
617 if (err < 0)
618 goto errout;
619
620 tb = fib_get_table(net, cfg.fc_table);
621 if (tb == NULL) {
622 err = -ESRCH;
623 goto errout;
624 }
625
626 err = fib_table_delete(tb, &cfg);
627 errout:
628 return err;
629 }
630
631 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
632 {
633 struct net *net = sock_net(skb->sk);
634 struct fib_config cfg;
635 struct fib_table *tb;
636 int err;
637
638 err = rtm_to_fib_config(net, skb, nlh, &cfg);
639 if (err < 0)
640 goto errout;
641
642 tb = fib_new_table(net, cfg.fc_table);
643 if (tb == NULL) {
644 err = -ENOBUFS;
645 goto errout;
646 }
647
648 err = fib_table_insert(tb, &cfg);
649 errout:
650 return err;
651 }
652
653 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
654 {
655 struct net *net = sock_net(skb->sk);
656 unsigned int h, s_h;
657 unsigned int e = 0, s_e;
658 struct fib_table *tb;
659 struct hlist_node *node;
660 struct hlist_head *head;
661 int dumped = 0;
662
663 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
664 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
665 return ip_rt_dump(skb, cb);
666
667 s_h = cb->args[0];
668 s_e = cb->args[1];
669
670 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
671 e = 0;
672 head = &net->ipv4.fib_table_hash[h];
673 hlist_for_each_entry(tb, node, head, tb_hlist) {
674 if (e < s_e)
675 goto next;
676 if (dumped)
677 memset(&cb->args[2], 0, sizeof(cb->args) -
678 2 * sizeof(cb->args[0]));
679 if (fib_table_dump(tb, skb, cb) < 0)
680 goto out;
681 dumped = 1;
682 next:
683 e++;
684 }
685 }
686 out:
687 cb->args[1] = e;
688 cb->args[0] = h;
689
690 return skb->len;
691 }
692
693 /* Prepare and feed intra-kernel routing request.
694 * Really, it should be netlink message, but :-( netlink
695 * can be not configured, so that we feed it directly
696 * to fib engine. It is legal, because all events occur
697 * only when netlink is already locked.
698 */
699 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
700 {
701 struct net *net = dev_net(ifa->ifa_dev->dev);
702 struct fib_table *tb;
703 struct fib_config cfg = {
704 .fc_protocol = RTPROT_KERNEL,
705 .fc_type = type,
706 .fc_dst = dst,
707 .fc_dst_len = dst_len,
708 .fc_prefsrc = ifa->ifa_local,
709 .fc_oif = ifa->ifa_dev->dev->ifindex,
710 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
711 .fc_nlinfo = {
712 .nl_net = net,
713 },
714 };
715
716 if (type == RTN_UNICAST)
717 tb = fib_new_table(net, RT_TABLE_MAIN);
718 else
719 tb = fib_new_table(net, RT_TABLE_LOCAL);
720
721 if (tb == NULL)
722 return;
723
724 cfg.fc_table = tb->tb_id;
725
726 if (type != RTN_LOCAL)
727 cfg.fc_scope = RT_SCOPE_LINK;
728 else
729 cfg.fc_scope = RT_SCOPE_HOST;
730
731 if (cmd == RTM_NEWROUTE)
732 fib_table_insert(tb, &cfg);
733 else
734 fib_table_delete(tb, &cfg);
735 }
736
737 void fib_add_ifaddr(struct in_ifaddr *ifa)
738 {
739 struct in_device *in_dev = ifa->ifa_dev;
740 struct net_device *dev = in_dev->dev;
741 struct in_ifaddr *prim = ifa;
742 __be32 mask = ifa->ifa_mask;
743 __be32 addr = ifa->ifa_local;
744 __be32 prefix = ifa->ifa_address & mask;
745
746 if (ifa->ifa_flags & IFA_F_SECONDARY) {
747 prim = inet_ifa_byprefix(in_dev, prefix, mask);
748 if (prim == NULL) {
749 pr_warn("%s: bug: prim == NULL\n", __func__);
750 return;
751 }
752 }
753
754 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
755
756 if (!(dev->flags & IFF_UP))
757 return;
758
759 /* Add broadcast address, if it is explicitly assigned. */
760 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
761 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
762
763 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
764 (prefix != addr || ifa->ifa_prefixlen < 32)) {
765 fib_magic(RTM_NEWROUTE,
766 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
767 prefix, ifa->ifa_prefixlen, prim);
768
769 /* Add network specific broadcasts, when it takes a sense */
770 if (ifa->ifa_prefixlen < 31) {
771 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
772 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
773 32, prim);
774 }
775 }
776 }
777
778 /* Delete primary or secondary address.
779 * Optionally, on secondary address promotion consider the addresses
780 * from subnet iprim as deleted, even if they are in device list.
781 * In this case the secondary ifa can be in device list.
782 */
783 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
784 {
785 struct in_device *in_dev = ifa->ifa_dev;
786 struct net_device *dev = in_dev->dev;
787 struct in_ifaddr *ifa1;
788 struct in_ifaddr *prim = ifa, *prim1 = NULL;
789 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
790 __be32 any = ifa->ifa_address & ifa->ifa_mask;
791 #define LOCAL_OK 1
792 #define BRD_OK 2
793 #define BRD0_OK 4
794 #define BRD1_OK 8
795 unsigned int ok = 0;
796 int subnet = 0; /* Primary network */
797 int gone = 1; /* Address is missing */
798 int same_prefsrc = 0; /* Another primary with same IP */
799
800 if (ifa->ifa_flags & IFA_F_SECONDARY) {
801 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
802 if (prim == NULL) {
803 pr_warn("%s: bug: prim == NULL\n", __func__);
804 return;
805 }
806 if (iprim && iprim != prim) {
807 pr_warn("%s: bug: iprim != prim\n", __func__);
808 return;
809 }
810 } else if (!ipv4_is_zeronet(any) &&
811 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
812 fib_magic(RTM_DELROUTE,
813 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
814 any, ifa->ifa_prefixlen, prim);
815 subnet = 1;
816 }
817
818 /* Deletion is more complicated than add.
819 * We should take care of not to delete too much :-)
820 *
821 * Scan address list to be sure that addresses are really gone.
822 */
823
824 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
825 if (ifa1 == ifa) {
826 /* promotion, keep the IP */
827 gone = 0;
828 continue;
829 }
830 /* Ignore IFAs from our subnet */
831 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
832 inet_ifa_match(ifa1->ifa_address, iprim))
833 continue;
834
835 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
836 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
837 /* Another address from our subnet? */
838 if (ifa1->ifa_mask == prim->ifa_mask &&
839 inet_ifa_match(ifa1->ifa_address, prim))
840 prim1 = prim;
841 else {
842 /* We reached the secondaries, so
843 * same_prefsrc should be determined.
844 */
845 if (!same_prefsrc)
846 continue;
847 /* Search new prim1 if ifa1 is not
848 * using the current prim1
849 */
850 if (!prim1 ||
851 ifa1->ifa_mask != prim1->ifa_mask ||
852 !inet_ifa_match(ifa1->ifa_address, prim1))
853 prim1 = inet_ifa_byprefix(in_dev,
854 ifa1->ifa_address,
855 ifa1->ifa_mask);
856 if (!prim1)
857 continue;
858 if (prim1->ifa_local != prim->ifa_local)
859 continue;
860 }
861 } else {
862 if (prim->ifa_local != ifa1->ifa_local)
863 continue;
864 prim1 = ifa1;
865 if (prim != prim1)
866 same_prefsrc = 1;
867 }
868 if (ifa->ifa_local == ifa1->ifa_local)
869 ok |= LOCAL_OK;
870 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
871 ok |= BRD_OK;
872 if (brd == ifa1->ifa_broadcast)
873 ok |= BRD1_OK;
874 if (any == ifa1->ifa_broadcast)
875 ok |= BRD0_OK;
876 /* primary has network specific broadcasts */
877 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
878 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
879 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
880
881 if (!ipv4_is_zeronet(any1)) {
882 if (ifa->ifa_broadcast == brd1 ||
883 ifa->ifa_broadcast == any1)
884 ok |= BRD_OK;
885 if (brd == brd1 || brd == any1)
886 ok |= BRD1_OK;
887 if (any == brd1 || any == any1)
888 ok |= BRD0_OK;
889 }
890 }
891 }
892
893 if (!(ok & BRD_OK))
894 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
895 if (subnet && ifa->ifa_prefixlen < 31) {
896 if (!(ok & BRD1_OK))
897 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
898 if (!(ok & BRD0_OK))
899 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
900 }
901 if (!(ok & LOCAL_OK)) {
902 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
903
904 /* Check, that this local address finally disappeared. */
905 if (gone &&
906 inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) {
907 /* And the last, but not the least thing.
908 * We must flush stray FIB entries.
909 *
910 * First of all, we scan fib_info list searching
911 * for stray nexthop entries, then ignite fib_flush.
912 */
913 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
914 fib_flush(dev_net(dev));
915 }
916 }
917 #undef LOCAL_OK
918 #undef BRD_OK
919 #undef BRD0_OK
920 #undef BRD1_OK
921 }
922
923 static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb)
924 {
925
926 struct fib_result res;
927 struct flowi4 fl4 = {
928 .flowi4_mark = frn->fl_mark,
929 .daddr = frn->fl_addr,
930 .flowi4_tos = frn->fl_tos,
931 .flowi4_scope = frn->fl_scope,
932 };
933
934 frn->err = -ENOENT;
935 if (tb) {
936 local_bh_disable();
937
938 frn->tb_id = tb->tb_id;
939 rcu_read_lock();
940 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
941
942 if (!frn->err) {
943 frn->prefixlen = res.prefixlen;
944 frn->nh_sel = res.nh_sel;
945 frn->type = res.type;
946 frn->scope = res.scope;
947 }
948 rcu_read_unlock();
949 local_bh_enable();
950 }
951 }
952
953 static void nl_fib_input(struct sk_buff *skb)
954 {
955 struct net *net;
956 struct fib_result_nl *frn;
957 struct nlmsghdr *nlh;
958 struct fib_table *tb;
959 u32 portid;
960
961 net = sock_net(skb->sk);
962 nlh = nlmsg_hdr(skb);
963 if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len ||
964 nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn)))
965 return;
966
967 skb = skb_clone(skb, GFP_KERNEL);
968 if (skb == NULL)
969 return;
970 nlh = nlmsg_hdr(skb);
971
972 frn = (struct fib_result_nl *) NLMSG_DATA(nlh);
973 tb = fib_get_table(net, frn->tb_id_in);
974
975 nl_fib_lookup(frn, tb);
976
977 portid = NETLINK_CB(skb).portid; /* pid of sending process */
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 = 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
1056 switch (event) {
1057 case NETDEV_UP:
1058 for_ifa(in_dev) {
1059 fib_add_ifaddr(ifa);
1060 } endfor_ifa(in_dev);
1061 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1062 fib_sync_up(dev);
1063 #endif
1064 atomic_inc(&net->ipv4.dev_addr_genid);
1065 rt_cache_flush(net);
1066 break;
1067 case NETDEV_DOWN:
1068 fib_disable_ip(dev, 0);
1069 break;
1070 case NETDEV_CHANGEMTU:
1071 case NETDEV_CHANGE:
1072 rt_cache_flush(net);
1073 break;
1074 }
1075 return NOTIFY_DONE;
1076 }
1077
1078 static struct notifier_block fib_inetaddr_notifier = {
1079 .notifier_call = fib_inetaddr_event,
1080 };
1081
1082 static struct notifier_block fib_netdev_notifier = {
1083 .notifier_call = fib_netdev_event,
1084 };
1085
1086 static int __net_init ip_fib_net_init(struct net *net)
1087 {
1088 int err;
1089 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1090
1091 /* Avoid false sharing : Use at least a full cache line */
1092 size = max_t(size_t, size, L1_CACHE_BYTES);
1093
1094 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1095 if (net->ipv4.fib_table_hash == NULL)
1096 return -ENOMEM;
1097
1098 err = fib4_rules_init(net);
1099 if (err < 0)
1100 goto fail;
1101 return 0;
1102
1103 fail:
1104 kfree(net->ipv4.fib_table_hash);
1105 return err;
1106 }
1107
1108 static void ip_fib_net_exit(struct net *net)
1109 {
1110 unsigned int i;
1111
1112 #ifdef CONFIG_IP_MULTIPLE_TABLES
1113 fib4_rules_exit(net);
1114 #endif
1115
1116 rtnl_lock();
1117 for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1118 struct fib_table *tb;
1119 struct hlist_head *head;
1120 struct hlist_node *node, *tmp;
1121
1122 head = &net->ipv4.fib_table_hash[i];
1123 hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) {
1124 hlist_del(node);
1125 fib_table_flush(tb);
1126 fib_free_table(tb);
1127 }
1128 }
1129 rtnl_unlock();
1130 kfree(net->ipv4.fib_table_hash);
1131 }
1132
1133 static int __net_init fib_net_init(struct net *net)
1134 {
1135 int error;
1136
1137 #ifdef CONFIG_IP_ROUTE_CLASSID
1138 net->ipv4.fib_num_tclassid_users = 0;
1139 #endif
1140 error = ip_fib_net_init(net);
1141 if (error < 0)
1142 goto out;
1143 error = nl_fib_lookup_init(net);
1144 if (error < 0)
1145 goto out_nlfl;
1146 error = fib_proc_init(net);
1147 if (error < 0)
1148 goto out_proc;
1149 out:
1150 return error;
1151
1152 out_proc:
1153 nl_fib_lookup_exit(net);
1154 out_nlfl:
1155 ip_fib_net_exit(net);
1156 goto out;
1157 }
1158
1159 static void __net_exit fib_net_exit(struct net *net)
1160 {
1161 fib_proc_exit(net);
1162 nl_fib_lookup_exit(net);
1163 ip_fib_net_exit(net);
1164 }
1165
1166 static struct pernet_operations fib_net_ops = {
1167 .init = fib_net_init,
1168 .exit = fib_net_exit,
1169 };
1170
1171 void __init ip_fib_init(void)
1172 {
1173 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1174 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1175 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1176
1177 register_pernet_subsys(&fib_net_ops);
1178 register_netdevice_notifier(&fib_netdev_notifier);
1179 register_inetaddr_notifier(&fib_inetaddr_notifier);
1180
1181 fib_trie_init();
1182 }
CRIS linux kernel tree