blob: b8c533fbdb63f0ab320b7d27735f2e5a6ea2b040 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Anycast support for IPv6
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +09003 * Linux INET6 implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
5 * Authors:
6 * David L Stevens (dlstevens@us.ibm.com)
7 *
8 * based heavily on net/ipv6/mcast.c
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
Randy Dunlap4fc268d2006-01-11 12:17:47 -080016#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/module.h>
18#include <linux/errno.h>
19#include <linux/types.h>
20#include <linux/random.h>
21#include <linux/string.h>
22#include <linux/socket.h>
23#include <linux/sockios.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/net.h>
25#include <linux/in6.h>
26#include <linux/netdevice.h>
27#include <linux/if_arp.h>
28#include <linux/route.h>
29#include <linux/init.h>
30#include <linux/proc_fs.h>
31#include <linux/seq_file.h>
32
33#include <net/sock.h>
34#include <net/snmp.h>
35
36#include <net/ipv6.h>
37#include <net/protocol.h>
38#include <net/if_inet6.h>
39#include <net/ndisc.h>
40#include <net/addrconf.h>
41#include <net/ip6_route.h>
42
43#include <net/checksum.h>
44
45static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr);
46
47/* Big ac list lock for all the sockets */
48static DEFINE_RWLOCK(ipv6_sk_ac_lock);
49
50static int
51ip6_onlink(struct in6_addr *addr, struct net_device *dev)
52{
53 struct inet6_dev *idev;
54 struct inet6_ifaddr *ifa;
55 int onlink;
56
57 onlink = 0;
YOSHIFUJI Hideaki8814c4b2006-09-22 14:44:24 -070058 rcu_read_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 idev = __in6_dev_get(dev);
60 if (idev) {
61 read_lock_bh(&idev->lock);
62 for (ifa=idev->addr_list; ifa; ifa=ifa->if_next) {
63 onlink = ipv6_prefix_equal(addr, &ifa->addr,
64 ifa->prefix_len);
65 if (onlink)
66 break;
67 }
68 read_unlock_bh(&idev->lock);
69 }
YOSHIFUJI Hideaki8814c4b2006-09-22 14:44:24 -070070 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 return onlink;
72}
73
74/*
75 * socket join an anycast group
76 */
77
78int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr)
79{
80 struct ipv6_pinfo *np = inet6_sk(sk);
81 struct net_device *dev = NULL;
82 struct inet6_dev *idev;
83 struct ipv6_ac_socklist *pac;
84 int ishost = !ipv6_devconf.forwarding;
85 int err = 0;
86
87 if (!capable(CAP_NET_ADMIN))
88 return -EPERM;
89 if (ipv6_addr_is_multicast(addr))
90 return -EINVAL;
91 if (ipv6_chk_addr(addr, NULL, 0))
92 return -EINVAL;
93
94 pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
95 if (pac == NULL)
96 return -ENOMEM;
97 pac->acl_next = NULL;
98 ipv6_addr_copy(&pac->acl_addr, addr);
99
100 if (ifindex == 0) {
101 struct rt6_info *rt;
102
103 rt = rt6_lookup(addr, NULL, 0, 0);
104 if (rt) {
105 dev = rt->rt6i_dev;
106 dev_hold(dev);
107 dst_release(&rt->u.dst);
108 } else if (ishost) {
109 err = -EADDRNOTAVAIL;
110 goto out_free_pac;
111 } else {
112 /* router, no matching interface: just pick one */
113
114 dev = dev_get_by_flags(IFF_UP, IFF_UP|IFF_LOOPBACK);
115 }
116 } else
117 dev = dev_get_by_index(ifindex);
118
119 if (dev == NULL) {
120 err = -ENODEV;
121 goto out_free_pac;
122 }
123
124 idev = in6_dev_get(dev);
125 if (!idev) {
126 if (ifindex)
127 err = -ENODEV;
128 else
129 err = -EADDRNOTAVAIL;
130 goto out_dev_put;
131 }
132 /* reset ishost, now that we have a specific device */
133 ishost = !idev->cnf.forwarding;
134 in6_dev_put(idev);
135
136 pac->acl_ifindex = dev->ifindex;
137
138 /* XXX
139 * For hosts, allow link-local or matching prefix anycasts.
140 * This obviates the need for propagating anycast routes while
141 * still allowing some non-router anycast participation.
142 */
143 if (!ip6_onlink(addr, dev)) {
144 if (ishost)
145 err = -EADDRNOTAVAIL;
146 if (err)
147 goto out_dev_put;
148 }
149
150 err = ipv6_dev_ac_inc(dev, addr);
151 if (err)
152 goto out_dev_put;
153
154 write_lock_bh(&ipv6_sk_ac_lock);
155 pac->acl_next = np->ipv6_ac_list;
156 np->ipv6_ac_list = pac;
157 write_unlock_bh(&ipv6_sk_ac_lock);
158
159 dev_put(dev);
160
161 return 0;
162
163out_dev_put:
164 dev_put(dev);
165out_free_pac:
166 sock_kfree_s(sk, pac, sizeof(*pac));
167 return err;
168}
169
170/*
171 * socket leave an anycast group
172 */
173int ipv6_sock_ac_drop(struct sock *sk, int ifindex, struct in6_addr *addr)
174{
175 struct ipv6_pinfo *np = inet6_sk(sk);
176 struct net_device *dev;
177 struct ipv6_ac_socklist *pac, *prev_pac;
178
179 write_lock_bh(&ipv6_sk_ac_lock);
180 prev_pac = NULL;
181 for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
182 if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
183 ipv6_addr_equal(&pac->acl_addr, addr))
184 break;
185 prev_pac = pac;
186 }
187 if (!pac) {
188 write_unlock_bh(&ipv6_sk_ac_lock);
189 return -ENOENT;
190 }
191 if (prev_pac)
192 prev_pac->acl_next = pac->acl_next;
193 else
194 np->ipv6_ac_list = pac->acl_next;
195
196 write_unlock_bh(&ipv6_sk_ac_lock);
197
198 dev = dev_get_by_index(pac->acl_ifindex);
199 if (dev) {
200 ipv6_dev_ac_dec(dev, &pac->acl_addr);
201 dev_put(dev);
202 }
203 sock_kfree_s(sk, pac, sizeof(*pac));
204 return 0;
205}
206
207void ipv6_sock_ac_close(struct sock *sk)
208{
209 struct ipv6_pinfo *np = inet6_sk(sk);
210 struct net_device *dev = NULL;
211 struct ipv6_ac_socklist *pac;
212 int prev_index;
213
214 write_lock_bh(&ipv6_sk_ac_lock);
215 pac = np->ipv6_ac_list;
216 np->ipv6_ac_list = NULL;
217 write_unlock_bh(&ipv6_sk_ac_lock);
218
219 prev_index = 0;
220 while (pac) {
221 struct ipv6_ac_socklist *next = pac->acl_next;
222
223 if (pac->acl_ifindex != prev_index) {
224 if (dev)
225 dev_put(dev);
226 dev = dev_get_by_index(pac->acl_ifindex);
227 prev_index = pac->acl_ifindex;
228 }
229 if (dev)
230 ipv6_dev_ac_dec(dev, &pac->acl_addr);
231 sock_kfree_s(sk, pac, sizeof(*pac));
232 pac = next;
233 }
234 if (dev)
235 dev_put(dev);
236}
237
238#if 0
239/* The function is not used, which is funny. Apparently, author
240 * supposed to use it to filter out datagrams inside udp/raw but forgot.
241 *
242 * It is OK, anycasts are not special comparing to delivery to unicasts.
243 */
244
245int inet6_ac_check(struct sock *sk, struct in6_addr *addr, int ifindex)
246{
247 struct ipv6_ac_socklist *pac;
248 struct ipv6_pinfo *np = inet6_sk(sk);
249 int found;
250
251 found = 0;
252 read_lock(&ipv6_sk_ac_lock);
253 for (pac=np->ipv6_ac_list; pac; pac=pac->acl_next) {
254 if (ifindex && pac->acl_ifindex != ifindex)
255 continue;
256 found = ipv6_addr_equal(&pac->acl_addr, addr);
257 if (found)
258 break;
259 }
260 read_unlock(&ipv6_sk_ac_lock);
261
262 return found;
263}
264
265#endif
266
267static void aca_put(struct ifacaddr6 *ac)
268{
269 if (atomic_dec_and_test(&ac->aca_refcnt)) {
270 in6_dev_put(ac->aca_idev);
271 dst_release(&ac->aca_rt->u.dst);
272 kfree(ac);
273 }
274}
275
276/*
277 * device anycast group inc (add if not found)
278 */
279int ipv6_dev_ac_inc(struct net_device *dev, struct in6_addr *addr)
280{
281 struct ifacaddr6 *aca;
282 struct inet6_dev *idev;
283 struct rt6_info *rt;
284 int err;
285
286 idev = in6_dev_get(dev);
287
288 if (idev == NULL)
289 return -EINVAL;
290
291 write_lock_bh(&idev->lock);
292 if (idev->dead) {
293 err = -ENODEV;
294 goto out;
295 }
296
297 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
298 if (ipv6_addr_equal(&aca->aca_addr, addr)) {
299 aca->aca_users++;
300 err = 0;
301 goto out;
302 }
303 }
304
305 /*
306 * not found: create a new one.
307 */
308
Ingo Oeser0c600ed2006-03-20 23:01:32 -0800309 aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310
311 if (aca == NULL) {
312 err = -ENOMEM;
313 goto out;
314 }
315
316 rt = addrconf_dst_alloc(idev, addr, 1);
317 if (IS_ERR(rt)) {
318 kfree(aca);
319 err = PTR_ERR(rt);
320 goto out;
321 }
322
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 ipv6_addr_copy(&aca->aca_addr, addr);
324 aca->aca_idev = idev;
325 aca->aca_rt = rt;
326 aca->aca_users = 1;
327 /* aca_tstamp should be updated upon changes */
328 aca->aca_cstamp = aca->aca_tstamp = jiffies;
329 atomic_set(&aca->aca_refcnt, 2);
330 spin_lock_init(&aca->aca_lock);
331
332 aca->aca_next = idev->ac_list;
333 idev->ac_list = aca;
334 write_unlock_bh(&idev->lock);
335
336 dst_hold(&rt->u.dst);
Thomas Graf40e22e82006-08-22 00:00:45 -0700337 if (ip6_ins_rt(rt))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 dst_release(&rt->u.dst);
339
340 addrconf_join_solict(dev, &aca->aca_addr);
341
342 aca_put(aca);
343 return 0;
344out:
345 write_unlock_bh(&idev->lock);
346 in6_dev_put(idev);
347 return err;
348}
349
350/*
351 * device anycast group decrement
352 */
353int __ipv6_dev_ac_dec(struct inet6_dev *idev, struct in6_addr *addr)
354{
355 struct ifacaddr6 *aca, *prev_aca;
356
357 write_lock_bh(&idev->lock);
358 prev_aca = NULL;
359 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
360 if (ipv6_addr_equal(&aca->aca_addr, addr))
361 break;
362 prev_aca = aca;
363 }
364 if (!aca) {
365 write_unlock_bh(&idev->lock);
366 return -ENOENT;
367 }
368 if (--aca->aca_users > 0) {
369 write_unlock_bh(&idev->lock);
370 return 0;
371 }
372 if (prev_aca)
373 prev_aca->aca_next = aca->aca_next;
374 else
375 idev->ac_list = aca->aca_next;
376 write_unlock_bh(&idev->lock);
377 addrconf_leave_solict(idev, &aca->aca_addr);
378
379 dst_hold(&aca->aca_rt->u.dst);
David S. Miller72d3b2c2006-08-22 00:13:07 -0700380 if (ip6_del_rt(aca->aca_rt))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 dst_free(&aca->aca_rt->u.dst);
382 else
383 dst_release(&aca->aca_rt->u.dst);
384
385 aca_put(aca);
386 return 0;
387}
388
389static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr)
390{
391 int ret;
392 struct inet6_dev *idev = in6_dev_get(dev);
393 if (idev == NULL)
394 return -ENODEV;
395 ret = __ipv6_dev_ac_dec(idev, addr);
396 in6_dev_put(idev);
397 return ret;
398}
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900399
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400/*
401 * check if the interface has this anycast address
402 */
403static int ipv6_chk_acast_dev(struct net_device *dev, struct in6_addr *addr)
404{
405 struct inet6_dev *idev;
406 struct ifacaddr6 *aca;
407
408 idev = in6_dev_get(dev);
409 if (idev) {
410 read_lock_bh(&idev->lock);
411 for (aca = idev->ac_list; aca; aca = aca->aca_next)
412 if (ipv6_addr_equal(&aca->aca_addr, addr))
413 break;
414 read_unlock_bh(&idev->lock);
415 in6_dev_put(idev);
416 return aca != 0;
417 }
418 return 0;
419}
420
421/*
422 * check if given interface (or any, if dev==0) has this anycast address
423 */
424int ipv6_chk_acast_addr(struct net_device *dev, struct in6_addr *addr)
425{
Pavel Emelianov7562f872007-05-03 15:13:45 -0700426 int found = 0;
427
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 if (dev)
429 return ipv6_chk_acast_dev(dev, addr);
430 read_lock(&dev_base_lock);
Pavel Emelianov7562f872007-05-03 15:13:45 -0700431 for_each_netdev(dev)
432 if (ipv6_chk_acast_dev(dev, addr)) {
433 found = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 break;
Pavel Emelianov7562f872007-05-03 15:13:45 -0700435 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 read_unlock(&dev_base_lock);
Pavel Emelianov7562f872007-05-03 15:13:45 -0700437 return found;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438}
439
440
441#ifdef CONFIG_PROC_FS
442struct ac6_iter_state {
443 struct net_device *dev;
444 struct inet6_dev *idev;
445};
446
447#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
448
449static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
450{
451 struct ifacaddr6 *im = NULL;
452 struct ac6_iter_state *state = ac6_seq_private(seq);
453
Pavel Emelianov7562f872007-05-03 15:13:45 -0700454 state->idev = NULL;
455 for_each_netdev(state->dev) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 struct inet6_dev *idev;
457 idev = in6_dev_get(state->dev);
458 if (!idev)
459 continue;
460 read_lock_bh(&idev->lock);
461 im = idev->ac_list;
462 if (im) {
463 state->idev = idev;
464 break;
465 }
466 read_unlock_bh(&idev->lock);
David Stevensaa6e4a92007-02-26 16:28:56 -0800467 in6_dev_put(idev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 }
469 return im;
470}
471
472static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
473{
474 struct ac6_iter_state *state = ac6_seq_private(seq);
475
476 im = im->aca_next;
477 while (!im) {
478 if (likely(state->idev != NULL)) {
479 read_unlock_bh(&state->idev->lock);
480 in6_dev_put(state->idev);
481 }
Pavel Emelianov7562f872007-05-03 15:13:45 -0700482 state->dev = next_net_device(state->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 if (!state->dev) {
484 state->idev = NULL;
485 break;
486 }
487 state->idev = in6_dev_get(state->dev);
488 if (!state->idev)
489 continue;
490 read_lock_bh(&state->idev->lock);
491 im = state->idev->ac_list;
492 }
493 return im;
494}
495
496static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
497{
498 struct ifacaddr6 *im = ac6_get_first(seq);
499 if (im)
500 while (pos && (im = ac6_get_next(seq, im)) != NULL)
501 --pos;
502 return pos ? NULL : im;
503}
504
505static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
506{
507 read_lock(&dev_base_lock);
508 return ac6_get_idx(seq, *pos);
509}
510
511static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
512{
513 struct ifacaddr6 *im;
514 im = ac6_get_next(seq, v);
515 ++*pos;
516 return im;
517}
518
519static void ac6_seq_stop(struct seq_file *seq, void *v)
520{
521 struct ac6_iter_state *state = ac6_seq_private(seq);
522 if (likely(state->idev != NULL)) {
523 read_unlock_bh(&state->idev->lock);
524 in6_dev_put(state->idev);
525 }
526 read_unlock(&dev_base_lock);
527}
528
529static int ac6_seq_show(struct seq_file *seq, void *v)
530{
531 struct ifacaddr6 *im = (struct ifacaddr6 *)v;
532 struct ac6_iter_state *state = ac6_seq_private(seq);
533
534 seq_printf(seq,
YOSHIFUJI Hideaki9343e792006-01-17 02:10:53 -0800535 "%-4d %-15s " NIP6_SEQFMT " %5d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 state->dev->ifindex, state->dev->name,
537 NIP6(im->aca_addr),
538 im->aca_users);
539 return 0;
540}
541
Philippe De Muyter56b3d972007-07-10 23:07:31 -0700542static const struct seq_operations ac6_seq_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 .start = ac6_seq_start,
544 .next = ac6_seq_next,
545 .stop = ac6_seq_stop,
546 .show = ac6_seq_show,
547};
548
549static int ac6_seq_open(struct inode *inode, struct file *file)
550{
551 struct seq_file *seq;
552 int rc = -ENOMEM;
Ingo Oeser0c600ed2006-03-20 23:01:32 -0800553 struct ac6_iter_state *s = kzalloc(sizeof(*s), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554
555 if (!s)
556 goto out;
557
558 rc = seq_open(file, &ac6_seq_ops);
559 if (rc)
560 goto out_kfree;
561
562 seq = file->private_data;
563 seq->private = s;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564out:
565 return rc;
566out_kfree:
567 kfree(s);
568 goto out;
569}
570
Arjan van de Ven9a321442007-02-12 00:55:35 -0800571static const struct file_operations ac6_seq_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 .owner = THIS_MODULE,
573 .open = ac6_seq_open,
574 .read = seq_read,
575 .llseek = seq_lseek,
576 .release = seq_release_private,
577};
578
579int __init ac6_proc_init(void)
580{
581 if (!proc_net_fops_create("anycast6", S_IRUGO, &ac6_seq_fops))
582 return -ENOMEM;
583
584 return 0;
585}
586
587void ac6_proc_exit(void)
588{
589 proc_net_remove("anycast6");
590}
591#endif
592