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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Anycast support for IPv6 | |
1ab1457c | 3 | * Linux INET6 implementation |
1da177e4 LT |
4 | * |
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 | ||
4fc268d2 | 16 | #include <linux/capability.h> |
1da177e4 LT |
17 | #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> | |
1da177e4 LT |
24 | #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> | |
5a0e3ad6 | 32 | #include <linux/slab.h> |
1da177e4 | 33 | |
457c4cbc | 34 | #include <net/net_namespace.h> |
1da177e4 LT |
35 | #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 | ||
47 | static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr); | |
48 | ||
49 | /* Big ac list lock for all the sockets */ | |
50 | static DEFINE_RWLOCK(ipv6_sk_ac_lock); | |
51 | ||
1da177e4 LT |
52 | |
53 | /* | |
54 | * socket join an anycast group | |
55 | */ | |
56 | ||
57 | int 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; | |
6ab57e7e | 63 | struct net *net = sock_net(sk); |
53b7997f | 64 | int ishost = !net->ipv6.devconf_all->forwarding; |
1da177e4 LT |
65 | int err = 0; |
66 | ||
67 | if (!capable(CAP_NET_ADMIN)) | |
68 | return -EPERM; | |
69 | if (ipv6_addr_is_multicast(addr)) | |
70 | return -EINVAL; | |
6ab57e7e | 71 | if (ipv6_chk_addr(net, addr, NULL, 0)) |
1da177e4 LT |
72 | 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 | ||
6ab57e7e | 83 | rt = rt6_lookup(net, addr, NULL, 0, 0); |
1da177e4 LT |
84 | 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 | ||
6ab57e7e | 94 | dev = dev_get_by_flags(net, IFF_UP, IFF_UP|IFF_LOOPBACK); |
1da177e4 LT |
95 | } |
96 | } else | |
6ab57e7e | 97 | dev = dev_get_by_index(net, ifindex); |
1da177e4 LT |
98 | |
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 | */ | |
52eeeb84 | 123 | if (!ipv6_chk_prefix(addr, dev)) { |
1da177e4 LT |
124 | 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 | ||
143 | out_dev_put: | |
144 | dev_put(dev); | |
145 | out_free_pac: | |
146 | sock_kfree_s(sk, pac, sizeof(*pac)); | |
147 | return err; | |
148 | } | |
149 | ||
150 | /* | |
151 | * socket leave an anycast group | |
152 | */ | |
153 | int 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; | |
6ab57e7e | 158 | struct net *net = sock_net(sk); |
1da177e4 LT |
159 | |
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 | ||
6ab57e7e | 179 | dev = dev_get_by_index(net, pac->acl_ifindex); |
1da177e4 LT |
180 | 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 | ||
188 | void 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; | |
6ab57e7e | 193 | struct net *net = sock_net(sk); |
1da177e4 LT |
194 | 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); | |
6ab57e7e | 208 | dev = dev_get_by_index(net, pac->acl_ifindex); |
1da177e4 LT |
209 | 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 | ||
227 | int 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 | ||
249 | static 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 | */ | |
261 | int 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 | ||
0c600eda | 291 | aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC); |
1da177e4 LT |
292 | |
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 | ||
1da177e4 LT |
305 | 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 | ||
84f59370 | 318 | ip6_ins_rt(rt); |
1da177e4 LT |
319 | |
320 | addrconf_join_solict(dev, &aca->aca_addr); | |
321 | ||
322 | aca_put(aca); | |
323 | return 0; | |
324 | out: | |
325 | write_unlock_bh(&idev->lock); | |
326 | in6_dev_put(idev); | |
327 | return err; | |
328 | } | |
329 | ||
330 | /* | |
331 | * device anycast group decrement | |
332 | */ | |
333 | int __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); | |
84f59370 | 360 | ip6_del_rt(aca->aca_rt); |
1da177e4 LT |
361 | |
362 | aca_put(aca); | |
363 | return 0; | |
364 | } | |
365 | ||
366 | static 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 | } | |
1ab1457c | 376 | |
1da177e4 LT |
377 | /* |
378 | * check if the interface has this anycast address | |
379 | */ | |
380 | static 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); | |
cfcabdcc | 393 | return aca != NULL; |
1da177e4 LT |
394 | } |
395 | return 0; | |
396 | } | |
397 | ||
398 | /* | |
399 | * check if given interface (or any, if dev==0) has this anycast address | |
400 | */ | |
6ab57e7e DL |
401 | int ipv6_chk_acast_addr(struct net *net, struct net_device *dev, |
402 | struct in6_addr *addr) | |
1da177e4 | 403 | { |
7562f876 PE |
404 | int found = 0; |
405 | ||
1da177e4 LT |
406 | if (dev) |
407 | return ipv6_chk_acast_dev(dev, addr); | |
c6d14c84 ED |
408 | rcu_read_lock(); |
409 | for_each_netdev_rcu(net, dev) | |
7562f876 PE |
410 | if (ipv6_chk_acast_dev(dev, addr)) { |
411 | found = 1; | |
1da177e4 | 412 | break; |
7562f876 | 413 | } |
c6d14c84 | 414 | rcu_read_unlock(); |
7562f876 | 415 | return found; |
1da177e4 LT |
416 | } |
417 | ||
418 | ||
419 | #ifdef CONFIG_PROC_FS | |
420 | struct ac6_iter_state { | |
6ab57e7e | 421 | struct seq_net_private p; |
1da177e4 LT |
422 | struct net_device *dev; |
423 | struct inet6_dev *idev; | |
424 | }; | |
425 | ||
426 | #define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private) | |
427 | ||
428 | static 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); | |
6ab57e7e | 432 | struct net *net = seq_file_net(seq); |
1da177e4 | 433 | |
7562f876 | 434 | state->idev = NULL; |
ce81b76a | 435 | for_each_netdev_rcu(net, state->dev) { |
1da177e4 | 436 | struct inet6_dev *idev; |
ce81b76a | 437 | idev = __in6_dev_get(state->dev); |
1da177e4 LT |
438 | 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 | ||
451 | static 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) { | |
ce81b76a | 457 | if (likely(state->idev != NULL)) |
1da177e4 | 458 | read_unlock_bh(&state->idev->lock); |
ce81b76a ED |
459 | |
460 | state->dev = next_net_device_rcu(state->dev); | |
1da177e4 LT |
461 | if (!state->dev) { |
462 | state->idev = NULL; | |
463 | break; | |
464 | } | |
ce81b76a | 465 | state->idev = __in6_dev_get(state->dev); |
1da177e4 LT |
466 | if (!state->idev) |
467 | continue; | |
468 | read_lock_bh(&state->idev->lock); | |
469 | im = state->idev->ac_list; | |
470 | } | |
471 | return im; | |
472 | } | |
473 | ||
474 | static 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 | ||
483 | static void *ac6_seq_start(struct seq_file *seq, loff_t *pos) | |
ce81b76a | 484 | __acquires(RCU) |
1da177e4 | 485 | { |
ce81b76a | 486 | rcu_read_lock(); |
1da177e4 LT |
487 | return ac6_get_idx(seq, *pos); |
488 | } | |
489 | ||
490 | static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
491 | { | |
ce81b76a ED |
492 | struct ifacaddr6 *im = ac6_get_next(seq, v); |
493 | ||
1da177e4 LT |
494 | ++*pos; |
495 | return im; | |
496 | } | |
497 | ||
498 | static void ac6_seq_stop(struct seq_file *seq, void *v) | |
ce81b76a | 499 | __releases(RCU) |
1da177e4 LT |
500 | { |
501 | struct ac6_iter_state *state = ac6_seq_private(seq); | |
ce81b76a | 502 | |
1da177e4 LT |
503 | if (likely(state->idev != NULL)) { |
504 | read_unlock_bh(&state->idev->lock); | |
ce81b76a | 505 | state->idev = NULL; |
1da177e4 | 506 | } |
ce81b76a | 507 | rcu_read_unlock(); |
1da177e4 LT |
508 | } |
509 | ||
510 | static 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 | ||
4b7a4274 | 515 | seq_printf(seq, "%-4d %-15s %pi6 %5d\n", |
1da177e4 | 516 | state->dev->ifindex, state->dev->name, |
b071195d | 517 | &im->aca_addr, im->aca_users); |
1da177e4 LT |
518 | return 0; |
519 | } | |
520 | ||
56b3d975 | 521 | static const struct seq_operations ac6_seq_ops = { |
1da177e4 LT |
522 | .start = ac6_seq_start, |
523 | .next = ac6_seq_next, | |
524 | .stop = ac6_seq_stop, | |
525 | .show = ac6_seq_show, | |
526 | }; | |
527 | ||
528 | static int ac6_seq_open(struct inode *inode, struct file *file) | |
529 | { | |
6ab57e7e DL |
530 | return seq_open_net(inode, file, &ac6_seq_ops, |
531 | sizeof(struct ac6_iter_state)); | |
1da177e4 LT |
532 | } |
533 | ||
9a32144e | 534 | static const struct file_operations ac6_seq_fops = { |
1da177e4 LT |
535 | .owner = THIS_MODULE, |
536 | .open = ac6_seq_open, | |
537 | .read = seq_read, | |
538 | .llseek = seq_lseek, | |
6ab57e7e | 539 | .release = seq_release_net, |
1da177e4 LT |
540 | }; |
541 | ||
2c8c1e72 | 542 | int __net_init ac6_proc_init(struct net *net) |
1da177e4 | 543 | { |
6ab57e7e | 544 | if (!proc_net_fops_create(net, "anycast6", S_IRUGO, &ac6_seq_fops)) |
1da177e4 LT |
545 | return -ENOMEM; |
546 | ||
547 | return 0; | |
548 | } | |
549 | ||
6ab57e7e | 550 | void ac6_proc_exit(struct net *net) |
1da177e4 | 551 | { |
6ab57e7e | 552 | proc_net_remove(net, "anycast6"); |
1da177e4 LT |
553 | } |
554 | #endif | |
555 |