blob: b5b07054508a5154315c99f0da67b903e9ce46ee [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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090032#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
Eric W. Biederman457c4cb2007-09-12 12:01:34 +020034#include <net/net_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include <net/sock.h>
36#include <net/snmp.h>
37
38#include <net/ipv6.h>
39#include <net/protocol.h>
40#include <net/if_inet6.h>
41#include <net/ndisc.h>
42#include <net/addrconf.h>
43#include <net/ip6_route.h>
44
45#include <net/checksum.h>
46
47static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr);
48
49/* Big ac list lock for all the sockets */
50static DEFINE_RWLOCK(ipv6_sk_ac_lock);
51
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
53/*
54 * socket join an anycast group
55 */
56
57int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr)
58{
59 struct ipv6_pinfo *np = inet6_sk(sk);
60 struct net_device *dev = NULL;
61 struct inet6_dev *idev;
62 struct ipv6_ac_socklist *pac;
Daniel Lezcano6ab57e72008-03-26 16:52:32 -070063 struct net *net = sock_net(sk);
YOSHIFUJI Hideaki53b79972008-07-19 22:35:03 -070064 int ishost = !net->ipv6.devconf_all->forwarding;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 int err = 0;
66
67 if (!capable(CAP_NET_ADMIN))
68 return -EPERM;
69 if (ipv6_addr_is_multicast(addr))
70 return -EINVAL;
Daniel Lezcano6ab57e72008-03-26 16:52:32 -070071 if (ipv6_chk_addr(net, addr, NULL, 0))
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 return -EINVAL;
73
74 pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
75 if (pac == NULL)
76 return -ENOMEM;
77 pac->acl_next = NULL;
78 ipv6_addr_copy(&pac->acl_addr, addr);
79
80 if (ifindex == 0) {
81 struct rt6_info *rt;
82
Daniel Lezcano6ab57e72008-03-26 16:52:32 -070083 rt = rt6_lookup(net, addr, NULL, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 if (rt) {
85 dev = rt->rt6i_dev;
86 dev_hold(dev);
87 dst_release(&rt->u.dst);
88 } else if (ishost) {
89 err = -EADDRNOTAVAIL;
90 goto out_free_pac;
91 } else {
92 /* router, no matching interface: just pick one */
93
Daniel Lezcano6ab57e72008-03-26 16:52:32 -070094 dev = dev_get_by_flags(net, IFF_UP, IFF_UP|IFF_LOOPBACK);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 }
96 } else
Daniel Lezcano6ab57e72008-03-26 16:52:32 -070097 dev = dev_get_by_index(net, ifindex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
99 if (dev == NULL) {
100 err = -ENODEV;
101 goto out_free_pac;
102 }
103
104 idev = in6_dev_get(dev);
105 if (!idev) {
106 if (ifindex)
107 err = -ENODEV;
108 else
109 err = -EADDRNOTAVAIL;
110 goto out_dev_put;
111 }
112 /* reset ishost, now that we have a specific device */
113 ishost = !idev->cnf.forwarding;
114 in6_dev_put(idev);
115
116 pac->acl_ifindex = dev->ifindex;
117
118 /* XXX
119 * For hosts, allow link-local or matching prefix anycasts.
120 * This obviates the need for propagating anycast routes while
121 * still allowing some non-router anycast participation.
122 */
YOSHIFUJI Hideaki52eeeb82008-03-15 22:54:23 -0400123 if (!ipv6_chk_prefix(addr, dev)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 if (ishost)
125 err = -EADDRNOTAVAIL;
126 if (err)
127 goto out_dev_put;
128 }
129
130 err = ipv6_dev_ac_inc(dev, addr);
131 if (err)
132 goto out_dev_put;
133
134 write_lock_bh(&ipv6_sk_ac_lock);
135 pac->acl_next = np->ipv6_ac_list;
136 np->ipv6_ac_list = pac;
137 write_unlock_bh(&ipv6_sk_ac_lock);
138
139 dev_put(dev);
140
141 return 0;
142
143out_dev_put:
144 dev_put(dev);
145out_free_pac:
146 sock_kfree_s(sk, pac, sizeof(*pac));
147 return err;
148}
149
150/*
151 * socket leave an anycast group
152 */
153int ipv6_sock_ac_drop(struct sock *sk, int ifindex, struct in6_addr *addr)
154{
155 struct ipv6_pinfo *np = inet6_sk(sk);
156 struct net_device *dev;
157 struct ipv6_ac_socklist *pac, *prev_pac;
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700158 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159
160 write_lock_bh(&ipv6_sk_ac_lock);
161 prev_pac = NULL;
162 for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
163 if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
164 ipv6_addr_equal(&pac->acl_addr, addr))
165 break;
166 prev_pac = pac;
167 }
168 if (!pac) {
169 write_unlock_bh(&ipv6_sk_ac_lock);
170 return -ENOENT;
171 }
172 if (prev_pac)
173 prev_pac->acl_next = pac->acl_next;
174 else
175 np->ipv6_ac_list = pac->acl_next;
176
177 write_unlock_bh(&ipv6_sk_ac_lock);
178
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700179 dev = dev_get_by_index(net, pac->acl_ifindex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 if (dev) {
181 ipv6_dev_ac_dec(dev, &pac->acl_addr);
182 dev_put(dev);
183 }
184 sock_kfree_s(sk, pac, sizeof(*pac));
185 return 0;
186}
187
188void ipv6_sock_ac_close(struct sock *sk)
189{
190 struct ipv6_pinfo *np = inet6_sk(sk);
191 struct net_device *dev = NULL;
192 struct ipv6_ac_socklist *pac;
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700193 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 int prev_index;
195
196 write_lock_bh(&ipv6_sk_ac_lock);
197 pac = np->ipv6_ac_list;
198 np->ipv6_ac_list = NULL;
199 write_unlock_bh(&ipv6_sk_ac_lock);
200
201 prev_index = 0;
202 while (pac) {
203 struct ipv6_ac_socklist *next = pac->acl_next;
204
205 if (pac->acl_ifindex != prev_index) {
206 if (dev)
207 dev_put(dev);
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700208 dev = dev_get_by_index(net, pac->acl_ifindex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 prev_index = pac->acl_ifindex;
210 }
211 if (dev)
212 ipv6_dev_ac_dec(dev, &pac->acl_addr);
213 sock_kfree_s(sk, pac, sizeof(*pac));
214 pac = next;
215 }
216 if (dev)
217 dev_put(dev);
218}
219
220#if 0
221/* The function is not used, which is funny. Apparently, author
222 * supposed to use it to filter out datagrams inside udp/raw but forgot.
223 *
224 * It is OK, anycasts are not special comparing to delivery to unicasts.
225 */
226
227int inet6_ac_check(struct sock *sk, struct in6_addr *addr, int ifindex)
228{
229 struct ipv6_ac_socklist *pac;
230 struct ipv6_pinfo *np = inet6_sk(sk);
231 int found;
232
233 found = 0;
234 read_lock(&ipv6_sk_ac_lock);
235 for (pac=np->ipv6_ac_list; pac; pac=pac->acl_next) {
236 if (ifindex && pac->acl_ifindex != ifindex)
237 continue;
238 found = ipv6_addr_equal(&pac->acl_addr, addr);
239 if (found)
240 break;
241 }
242 read_unlock(&ipv6_sk_ac_lock);
243
244 return found;
245}
246
247#endif
248
249static void aca_put(struct ifacaddr6 *ac)
250{
251 if (atomic_dec_and_test(&ac->aca_refcnt)) {
252 in6_dev_put(ac->aca_idev);
253 dst_release(&ac->aca_rt->u.dst);
254 kfree(ac);
255 }
256}
257
258/*
259 * device anycast group inc (add if not found)
260 */
261int ipv6_dev_ac_inc(struct net_device *dev, struct in6_addr *addr)
262{
263 struct ifacaddr6 *aca;
264 struct inet6_dev *idev;
265 struct rt6_info *rt;
266 int err;
267
268 idev = in6_dev_get(dev);
269
270 if (idev == NULL)
271 return -EINVAL;
272
273 write_lock_bh(&idev->lock);
274 if (idev->dead) {
275 err = -ENODEV;
276 goto out;
277 }
278
279 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
280 if (ipv6_addr_equal(&aca->aca_addr, addr)) {
281 aca->aca_users++;
282 err = 0;
283 goto out;
284 }
285 }
286
287 /*
288 * not found: create a new one.
289 */
290
Ingo Oeser0c600ed2006-03-20 23:01:32 -0800291 aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292
293 if (aca == NULL) {
294 err = -ENOMEM;
295 goto out;
296 }
297
298 rt = addrconf_dst_alloc(idev, addr, 1);
299 if (IS_ERR(rt)) {
300 kfree(aca);
301 err = PTR_ERR(rt);
302 goto out;
303 }
304
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 ipv6_addr_copy(&aca->aca_addr, addr);
306 aca->aca_idev = idev;
307 aca->aca_rt = rt;
308 aca->aca_users = 1;
309 /* aca_tstamp should be updated upon changes */
310 aca->aca_cstamp = aca->aca_tstamp = jiffies;
311 atomic_set(&aca->aca_refcnt, 2);
312 spin_lock_init(&aca->aca_lock);
313
314 aca->aca_next = idev->ac_list;
315 idev->ac_list = aca;
316 write_unlock_bh(&idev->lock);
317
Denis V. Lunev84f59372008-04-03 13:33:00 -0700318 ip6_ins_rt(rt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319
320 addrconf_join_solict(dev, &aca->aca_addr);
321
322 aca_put(aca);
323 return 0;
324out:
325 write_unlock_bh(&idev->lock);
326 in6_dev_put(idev);
327 return err;
328}
329
330/*
331 * device anycast group decrement
332 */
333int __ipv6_dev_ac_dec(struct inet6_dev *idev, struct in6_addr *addr)
334{
335 struct ifacaddr6 *aca, *prev_aca;
336
337 write_lock_bh(&idev->lock);
338 prev_aca = NULL;
339 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
340 if (ipv6_addr_equal(&aca->aca_addr, addr))
341 break;
342 prev_aca = aca;
343 }
344 if (!aca) {
345 write_unlock_bh(&idev->lock);
346 return -ENOENT;
347 }
348 if (--aca->aca_users > 0) {
349 write_unlock_bh(&idev->lock);
350 return 0;
351 }
352 if (prev_aca)
353 prev_aca->aca_next = aca->aca_next;
354 else
355 idev->ac_list = aca->aca_next;
356 write_unlock_bh(&idev->lock);
357 addrconf_leave_solict(idev, &aca->aca_addr);
358
359 dst_hold(&aca->aca_rt->u.dst);
Denis V. Lunev84f59372008-04-03 13:33:00 -0700360 ip6_del_rt(aca->aca_rt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361
362 aca_put(aca);
363 return 0;
364}
365
366static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr)
367{
368 int ret;
369 struct inet6_dev *idev = in6_dev_get(dev);
370 if (idev == NULL)
371 return -ENODEV;
372 ret = __ipv6_dev_ac_dec(idev, addr);
373 in6_dev_put(idev);
374 return ret;
375}
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900376
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377/*
378 * check if the interface has this anycast address
379 */
380static int ipv6_chk_acast_dev(struct net_device *dev, struct in6_addr *addr)
381{
382 struct inet6_dev *idev;
383 struct ifacaddr6 *aca;
384
385 idev = in6_dev_get(dev);
386 if (idev) {
387 read_lock_bh(&idev->lock);
388 for (aca = idev->ac_list; aca; aca = aca->aca_next)
389 if (ipv6_addr_equal(&aca->aca_addr, addr))
390 break;
391 read_unlock_bh(&idev->lock);
392 in6_dev_put(idev);
Stephen Hemmingercfcabdc2007-10-09 01:59:42 -0700393 return aca != NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 }
395 return 0;
396}
397
398/*
399 * check if given interface (or any, if dev==0) has this anycast address
400 */
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700401int ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
402 struct in6_addr *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403{
Pavel Emelianov7562f872007-05-03 15:13:45 -0700404 int found = 0;
405
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 if (dev)
407 return ipv6_chk_acast_dev(dev, addr);
Eric Dumazetc6d14c82009-11-04 05:43:23 -0800408 rcu_read_lock();
409 for_each_netdev_rcu(net, dev)
Pavel Emelianov7562f872007-05-03 15:13:45 -0700410 if (ipv6_chk_acast_dev(dev, addr)) {
411 found = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 break;
Pavel Emelianov7562f872007-05-03 15:13:45 -0700413 }
Eric Dumazetc6d14c82009-11-04 05:43:23 -0800414 rcu_read_unlock();
Pavel Emelianov7562f872007-05-03 15:13:45 -0700415 return found;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416}
417
418
419#ifdef CONFIG_PROC_FS
420struct ac6_iter_state {
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700421 struct seq_net_private p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 struct net_device *dev;
423 struct inet6_dev *idev;
424};
425
426#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
427
428static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
429{
430 struct ifacaddr6 *im = NULL;
431 struct ac6_iter_state *state = ac6_seq_private(seq);
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700432 struct net *net = seq_file_net(seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433
Pavel Emelianov7562f872007-05-03 15:13:45 -0700434 state->idev = NULL;
Eric Dumazetce81b762009-11-11 17:34:30 +0000435 for_each_netdev_rcu(net, state->dev) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 struct inet6_dev *idev;
Eric Dumazetce81b762009-11-11 17:34:30 +0000437 idev = __in6_dev_get(state->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 if (!idev)
439 continue;
440 read_lock_bh(&idev->lock);
441 im = idev->ac_list;
442 if (im) {
443 state->idev = idev;
444 break;
445 }
446 read_unlock_bh(&idev->lock);
447 }
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) {
Eric Dumazetce81b762009-11-11 17:34:30 +0000457 if (likely(state->idev != NULL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 read_unlock_bh(&state->idev->lock);
Eric Dumazetce81b762009-11-11 17:34:30 +0000459
460 state->dev = next_net_device_rcu(state->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 if (!state->dev) {
462 state->idev = NULL;
463 break;
464 }
Eric Dumazetce81b762009-11-11 17:34:30 +0000465 state->idev = __in6_dev_get(state->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 if (!state->idev)
467 continue;
468 read_lock_bh(&state->idev->lock);
469 im = state->idev->ac_list;
470 }
471 return im;
472}
473
474static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
475{
476 struct ifacaddr6 *im = ac6_get_first(seq);
477 if (im)
478 while (pos && (im = ac6_get_next(seq, im)) != NULL)
479 --pos;
480 return pos ? NULL : im;
481}
482
483static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
Eric Dumazetce81b762009-11-11 17:34:30 +0000484 __acquires(RCU)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485{
Eric Dumazetce81b762009-11-11 17:34:30 +0000486 rcu_read_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 return ac6_get_idx(seq, *pos);
488}
489
490static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
491{
Eric Dumazetce81b762009-11-11 17:34:30 +0000492 struct ifacaddr6 *im = ac6_get_next(seq, v);
493
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 ++*pos;
495 return im;
496}
497
498static void ac6_seq_stop(struct seq_file *seq, void *v)
Eric Dumazetce81b762009-11-11 17:34:30 +0000499 __releases(RCU)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500{
501 struct ac6_iter_state *state = ac6_seq_private(seq);
Eric Dumazetce81b762009-11-11 17:34:30 +0000502
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 if (likely(state->idev != NULL)) {
504 read_unlock_bh(&state->idev->lock);
Eric Dumazetce81b762009-11-11 17:34:30 +0000505 state->idev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 }
Eric Dumazetce81b762009-11-11 17:34:30 +0000507 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508}
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
Harvey Harrison4b7a4272008-10-29 12:50:24 -0700515 seq_printf(seq, "%-4d %-15s %pi6 %5d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 state->dev->ifindex, state->dev->name,
Harvey Harrisonb0711952008-10-28 16:05:40 -0700517 &im->aca_addr, im->aca_users);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 return 0;
519}
520
Philippe De Muyter56b3d972007-07-10 23:07:31 -0700521static const struct seq_operations ac6_seq_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 .start = ac6_seq_start,
523 .next = ac6_seq_next,
524 .stop = ac6_seq_stop,
525 .show = ac6_seq_show,
526};
527
528static int ac6_seq_open(struct inode *inode, struct file *file)
529{
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700530 return seq_open_net(inode, file, &ac6_seq_ops,
531 sizeof(struct ac6_iter_state));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532}
533
Arjan van de Ven9a321442007-02-12 00:55:35 -0800534static const struct file_operations ac6_seq_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 .owner = THIS_MODULE,
536 .open = ac6_seq_open,
537 .read = seq_read,
538 .llseek = seq_lseek,
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700539 .release = seq_release_net,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540};
541
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +0000542int __net_init ac6_proc_init(struct net *net)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543{
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700544 if (!proc_net_fops_create(net, "anycast6", S_IRUGO, &ac6_seq_fops))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 return -ENOMEM;
546
547 return 0;
548}
549
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700550void ac6_proc_exit(struct net *net)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551{
Daniel Lezcano6ab57e72008-03-26 16:52:32 -0700552 proc_net_remove(net, "anycast6");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553}
554#endif
555