blob: 4e1b29fabdf0da93e8b5f6edca9e0fd89efb4418 [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
Eric W. Biederman457c4cb2007-09-12 12:01:34 +020033#include <net/net_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <net/sock.h>
35#include <net/snmp.h>
36
37#include <net/ipv6.h>
38#include <net/protocol.h>
39#include <net/if_inet6.h>
40#include <net/ndisc.h>
41#include <net/addrconf.h>
42#include <net/ip6_route.h>
43
44#include <net/checksum.h>
45
46static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr);
47
48/* Big ac list lock for all the sockets */
49static DEFINE_RWLOCK(ipv6_sk_ac_lock);
50
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
52/*
53 * socket join an anycast group
54 */
55
56int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr)
57{
58 struct ipv6_pinfo *np = inet6_sk(sk);
59 struct net_device *dev = NULL;
60 struct inet6_dev *idev;
61 struct ipv6_ac_socklist *pac;
Daniel Lezcano6ab57e72008-03-26 16:52:32 -070062 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 int ishost = !ipv6_devconf.forwarding;
64 int err = 0;
65
66 if (!capable(CAP_NET_ADMIN))
67 return -EPERM;
68 if (ipv6_addr_is_multicast(addr))
69 return -EINVAL;
Daniel Lezcano6ab57e72008-03-26 16:52:32 -070070 if (ipv6_chk_addr(net, addr, NULL, 0))
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 return -EINVAL;
72
73 pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
74 if (pac == NULL)
75 return -ENOMEM;
76 pac->acl_next = NULL;
77 ipv6_addr_copy(&pac->acl_addr, addr);
78
79 if (ifindex == 0) {
80 struct rt6_info *rt;
81
Daniel Lezcano6ab57e72008-03-26 16:52:32 -070082 rt = rt6_lookup(net, addr, NULL, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 if (rt) {
84 dev = rt->rt6i_dev;
85 dev_hold(dev);
86 dst_release(&rt->u.dst);
87 } else if (ishost) {
88 err = -EADDRNOTAVAIL;
89 goto out_free_pac;
90 } else {
91 /* router, no matching interface: just pick one */
92
Daniel Lezcano6ab57e72008-03-26 16:52:32 -070093 dev = dev_get_by_flags(net, IFF_UP, IFF_UP|IFF_LOOPBACK);
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 }
95 } else
Daniel Lezcano6ab57e72008-03-26 16:52:32 -070096 dev = dev_get_by_index(net, ifindex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
98 if (dev == NULL) {
99 err = -ENODEV;
100 goto out_free_pac;
101 }
102
103 idev = in6_dev_get(dev);
104 if (!idev) {
105 if (ifindex)
106 err = -ENODEV;
107 else
108 err = -EADDRNOTAVAIL;
109 goto out_dev_put;
110 }
111 /* reset ishost, now that we have a specific device */
112 ishost = !idev->cnf.forwarding;
113 in6_dev_put(idev);
114
115 pac->acl_ifindex = dev->ifindex;
116
117 /* XXX
118 * For hosts, allow link-local or matching prefix anycasts.
119 * This obviates the need for propagating anycast routes while
120 * still allowing some non-router anycast participation.
121 */
YOSHIFUJI Hideaki52eeeb82008-03-15 22:54:23 -0400122 if (!ipv6_chk_prefix(addr, dev)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 if (ishost)
124 err = -EADDRNOTAVAIL;
125 if (err)
126 goto out_dev_put;
127 }
128
129 err = ipv6_dev_ac_inc(dev, addr);
130 if (err)
131 goto out_dev_put;
132
133 write_lock_bh(&ipv6_sk_ac_lock);
134 pac->acl_next = np->ipv6_ac_list;
135 np->ipv6_ac_list = pac;
136 write_unlock_bh(&ipv6_sk_ac_lock);
137
138 dev_put(dev);
139
140 return 0;
141
142out_dev_put:
143 dev_put(dev);
144out_free_pac:
145 sock_kfree_s(sk, pac, sizeof(*pac));
146 return err;
147}
148
149/*
150 * socket leave an anycast group
151 */
152int ipv6_sock_ac_drop(struct sock *sk, int ifindex, struct in6_addr *addr)
153{
154 struct ipv6_pinfo *np = inet6_sk(sk);
155 struct net_device *dev;
156 struct ipv6_ac_socklist *pac, *prev_pac;
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700157 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158
159 write_lock_bh(&ipv6_sk_ac_lock);
160 prev_pac = NULL;
161 for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
162 if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
163 ipv6_addr_equal(&pac->acl_addr, addr))
164 break;
165 prev_pac = pac;
166 }
167 if (!pac) {
168 write_unlock_bh(&ipv6_sk_ac_lock);
169 return -ENOENT;
170 }
171 if (prev_pac)
172 prev_pac->acl_next = pac->acl_next;
173 else
174 np->ipv6_ac_list = pac->acl_next;
175
176 write_unlock_bh(&ipv6_sk_ac_lock);
177
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700178 dev = dev_get_by_index(net, pac->acl_ifindex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 if (dev) {
180 ipv6_dev_ac_dec(dev, &pac->acl_addr);
181 dev_put(dev);
182 }
183 sock_kfree_s(sk, pac, sizeof(*pac));
184 return 0;
185}
186
187void ipv6_sock_ac_close(struct sock *sk)
188{
189 struct ipv6_pinfo *np = inet6_sk(sk);
190 struct net_device *dev = NULL;
191 struct ipv6_ac_socklist *pac;
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700192 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 int prev_index;
194
195 write_lock_bh(&ipv6_sk_ac_lock);
196 pac = np->ipv6_ac_list;
197 np->ipv6_ac_list = NULL;
198 write_unlock_bh(&ipv6_sk_ac_lock);
199
200 prev_index = 0;
201 while (pac) {
202 struct ipv6_ac_socklist *next = pac->acl_next;
203
204 if (pac->acl_ifindex != prev_index) {
205 if (dev)
206 dev_put(dev);
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700207 dev = dev_get_by_index(net, pac->acl_ifindex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 prev_index = pac->acl_ifindex;
209 }
210 if (dev)
211 ipv6_dev_ac_dec(dev, &pac->acl_addr);
212 sock_kfree_s(sk, pac, sizeof(*pac));
213 pac = next;
214 }
215 if (dev)
216 dev_put(dev);
217}
218
219#if 0
220/* The function is not used, which is funny. Apparently, author
221 * supposed to use it to filter out datagrams inside udp/raw but forgot.
222 *
223 * It is OK, anycasts are not special comparing to delivery to unicasts.
224 */
225
226int inet6_ac_check(struct sock *sk, struct in6_addr *addr, int ifindex)
227{
228 struct ipv6_ac_socklist *pac;
229 struct ipv6_pinfo *np = inet6_sk(sk);
230 int found;
231
232 found = 0;
233 read_lock(&ipv6_sk_ac_lock);
234 for (pac=np->ipv6_ac_list; pac; pac=pac->acl_next) {
235 if (ifindex && pac->acl_ifindex != ifindex)
236 continue;
237 found = ipv6_addr_equal(&pac->acl_addr, addr);
238 if (found)
239 break;
240 }
241 read_unlock(&ipv6_sk_ac_lock);
242
243 return found;
244}
245
246#endif
247
248static void aca_put(struct ifacaddr6 *ac)
249{
250 if (atomic_dec_and_test(&ac->aca_refcnt)) {
251 in6_dev_put(ac->aca_idev);
252 dst_release(&ac->aca_rt->u.dst);
253 kfree(ac);
254 }
255}
256
257/*
258 * device anycast group inc (add if not found)
259 */
260int ipv6_dev_ac_inc(struct net_device *dev, struct in6_addr *addr)
261{
262 struct ifacaddr6 *aca;
263 struct inet6_dev *idev;
264 struct rt6_info *rt;
265 int err;
266
267 idev = in6_dev_get(dev);
268
269 if (idev == NULL)
270 return -EINVAL;
271
272 write_lock_bh(&idev->lock);
273 if (idev->dead) {
274 err = -ENODEV;
275 goto out;
276 }
277
278 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
279 if (ipv6_addr_equal(&aca->aca_addr, addr)) {
280 aca->aca_users++;
281 err = 0;
282 goto out;
283 }
284 }
285
286 /*
287 * not found: create a new one.
288 */
289
Ingo Oeser0c600ed2006-03-20 23:01:32 -0800290 aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291
292 if (aca == NULL) {
293 err = -ENOMEM;
294 goto out;
295 }
296
297 rt = addrconf_dst_alloc(idev, addr, 1);
298 if (IS_ERR(rt)) {
299 kfree(aca);
300 err = PTR_ERR(rt);
301 goto out;
302 }
303
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 ipv6_addr_copy(&aca->aca_addr, addr);
305 aca->aca_idev = idev;
306 aca->aca_rt = rt;
307 aca->aca_users = 1;
308 /* aca_tstamp should be updated upon changes */
309 aca->aca_cstamp = aca->aca_tstamp = jiffies;
310 atomic_set(&aca->aca_refcnt, 2);
311 spin_lock_init(&aca->aca_lock);
312
313 aca->aca_next = idev->ac_list;
314 idev->ac_list = aca;
315 write_unlock_bh(&idev->lock);
316
Denis V. Lunev84f59372008-04-03 13:33:00 -0700317 ip6_ins_rt(rt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318
319 addrconf_join_solict(dev, &aca->aca_addr);
320
321 aca_put(aca);
322 return 0;
323out:
324 write_unlock_bh(&idev->lock);
325 in6_dev_put(idev);
326 return err;
327}
328
329/*
330 * device anycast group decrement
331 */
332int __ipv6_dev_ac_dec(struct inet6_dev *idev, struct in6_addr *addr)
333{
334 struct ifacaddr6 *aca, *prev_aca;
335
336 write_lock_bh(&idev->lock);
337 prev_aca = NULL;
338 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
339 if (ipv6_addr_equal(&aca->aca_addr, addr))
340 break;
341 prev_aca = aca;
342 }
343 if (!aca) {
344 write_unlock_bh(&idev->lock);
345 return -ENOENT;
346 }
347 if (--aca->aca_users > 0) {
348 write_unlock_bh(&idev->lock);
349 return 0;
350 }
351 if (prev_aca)
352 prev_aca->aca_next = aca->aca_next;
353 else
354 idev->ac_list = aca->aca_next;
355 write_unlock_bh(&idev->lock);
356 addrconf_leave_solict(idev, &aca->aca_addr);
357
358 dst_hold(&aca->aca_rt->u.dst);
Denis V. Lunev84f59372008-04-03 13:33:00 -0700359 ip6_del_rt(aca->aca_rt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360
361 aca_put(aca);
362 return 0;
363}
364
365static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr)
366{
367 int ret;
368 struct inet6_dev *idev = in6_dev_get(dev);
369 if (idev == NULL)
370 return -ENODEV;
371 ret = __ipv6_dev_ac_dec(idev, addr);
372 in6_dev_put(idev);
373 return ret;
374}
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900375
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376/*
377 * check if the interface has this anycast address
378 */
379static int ipv6_chk_acast_dev(struct net_device *dev, struct in6_addr *addr)
380{
381 struct inet6_dev *idev;
382 struct ifacaddr6 *aca;
383
384 idev = in6_dev_get(dev);
385 if (idev) {
386 read_lock_bh(&idev->lock);
387 for (aca = idev->ac_list; aca; aca = aca->aca_next)
388 if (ipv6_addr_equal(&aca->aca_addr, addr))
389 break;
390 read_unlock_bh(&idev->lock);
391 in6_dev_put(idev);
Stephen Hemmingercfcabdc2007-10-09 01:59:42 -0700392 return aca != NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 }
394 return 0;
395}
396
397/*
398 * check if given interface (or any, if dev==0) has this anycast address
399 */
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700400int ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
401 struct in6_addr *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402{
Pavel Emelianov7562f872007-05-03 15:13:45 -0700403 int found = 0;
404
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 if (dev)
406 return ipv6_chk_acast_dev(dev, addr);
407 read_lock(&dev_base_lock);
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700408 for_each_netdev(net, dev)
Pavel Emelianov7562f872007-05-03 15:13:45 -0700409 if (ipv6_chk_acast_dev(dev, addr)) {
410 found = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 break;
Pavel Emelianov7562f872007-05-03 15:13:45 -0700412 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 read_unlock(&dev_base_lock);
Pavel Emelianov7562f872007-05-03 15:13:45 -0700414 return found;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415}
416
417
418#ifdef CONFIG_PROC_FS
419struct ac6_iter_state {
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700420 struct seq_net_private p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 struct net_device *dev;
422 struct inet6_dev *idev;
423};
424
425#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
426
427static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
428{
429 struct ifacaddr6 *im = NULL;
430 struct ac6_iter_state *state = ac6_seq_private(seq);
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700431 struct net *net = seq_file_net(seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432
Pavel Emelianov7562f872007-05-03 15:13:45 -0700433 state->idev = NULL;
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700434 for_each_netdev(net, state->dev) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 struct inet6_dev *idev;
436 idev = in6_dev_get(state->dev);
437 if (!idev)
438 continue;
439 read_lock_bh(&idev->lock);
440 im = idev->ac_list;
441 if (im) {
442 state->idev = idev;
443 break;
444 }
445 read_unlock_bh(&idev->lock);
David Stevensaa6e4a92007-02-26 16:28:56 -0800446 in6_dev_put(idev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 }
448 return im;
449}
450
451static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
452{
453 struct ac6_iter_state *state = ac6_seq_private(seq);
454
455 im = im->aca_next;
456 while (!im) {
457 if (likely(state->idev != NULL)) {
458 read_unlock_bh(&state->idev->lock);
459 in6_dev_put(state->idev);
460 }
Pavel Emelianov7562f872007-05-03 15:13:45 -0700461 state->dev = next_net_device(state->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 if (!state->dev) {
463 state->idev = NULL;
464 break;
465 }
466 state->idev = in6_dev_get(state->dev);
467 if (!state->idev)
468 continue;
469 read_lock_bh(&state->idev->lock);
470 im = state->idev->ac_list;
471 }
472 return im;
473}
474
475static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
476{
477 struct ifacaddr6 *im = ac6_get_first(seq);
478 if (im)
479 while (pos && (im = ac6_get_next(seq, im)) != NULL)
480 --pos;
481 return pos ? NULL : im;
482}
483
484static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
Eric Dumazet9a429c42008-01-01 21:58:02 -0800485 __acquires(dev_base_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486{
487 read_lock(&dev_base_lock);
488 return ac6_get_idx(seq, *pos);
489}
490
491static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
492{
493 struct ifacaddr6 *im;
494 im = ac6_get_next(seq, v);
495 ++*pos;
496 return im;
497}
498
499static void ac6_seq_stop(struct seq_file *seq, void *v)
Eric Dumazet9a429c42008-01-01 21:58:02 -0800500 __releases(dev_base_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501{
502 struct ac6_iter_state *state = ac6_seq_private(seq);
503 if (likely(state->idev != NULL)) {
504 read_unlock_bh(&state->idev->lock);
505 in6_dev_put(state->idev);
506 }
507 read_unlock(&dev_base_lock);
508}
509
510static int ac6_seq_show(struct seq_file *seq, void *v)
511{
512 struct ifacaddr6 *im = (struct ifacaddr6 *)v;
513 struct ac6_iter_state *state = ac6_seq_private(seq);
514
515 seq_printf(seq,
YOSHIFUJI Hideaki9343e792006-01-17 02:10:53 -0800516 "%-4d %-15s " NIP6_SEQFMT " %5d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 state->dev->ifindex, state->dev->name,
518 NIP6(im->aca_addr),
519 im->aca_users);
520 return 0;
521}
522
Philippe De Muyter56b3d972007-07-10 23:07:31 -0700523static const struct seq_operations ac6_seq_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 .start = ac6_seq_start,
525 .next = ac6_seq_next,
526 .stop = ac6_seq_stop,
527 .show = ac6_seq_show,
528};
529
530static int ac6_seq_open(struct inode *inode, struct file *file)
531{
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700532 return seq_open_net(inode, file, &ac6_seq_ops,
533 sizeof(struct ac6_iter_state));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534}
535
Arjan van de Ven9a321442007-02-12 00:55:35 -0800536static const struct file_operations ac6_seq_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 .owner = THIS_MODULE,
538 .open = ac6_seq_open,
539 .read = seq_read,
540 .llseek = seq_lseek,
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700541 .release = seq_release_net,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542};
543
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700544int ac6_proc_init(struct net *net)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545{
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700546 if (!proc_net_fops_create(net, "anycast6", S_IRUGO, &ac6_seq_fops))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 return -ENOMEM;
548
549 return 0;
550}
551
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700552void ac6_proc_exit(struct net *net)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553{
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700554 proc_net_remove(net, "anycast6");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555}
556#endif
557