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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 | ||
b71d1d42 | 47 | static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr); |
1da177e4 LT |
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 | ||
b71d1d42 | 57 | int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr) |
1da177e4 LT |
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 | ||
af31f412 | 67 | if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) |
1da177e4 LT |
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; | |
4e3fd7a0 | 78 | pac->acl_addr = *addr; |
1da177e4 | 79 | |
bb69ae04 | 80 | rcu_read_lock(); |
1da177e4 LT |
81 | if (ifindex == 0) { |
82 | struct rt6_info *rt; | |
83 | ||
6ab57e7e | 84 | rt = rt6_lookup(net, addr, NULL, 0, 0); |
1da177e4 | 85 | if (rt) { |
d1918542 | 86 | dev = rt->dst.dev; |
94e187c0 | 87 | ip6_rt_put(rt); |
1da177e4 LT |
88 | } else if (ishost) { |
89 | err = -EADDRNOTAVAIL; | |
bb69ae04 | 90 | goto error; |
1da177e4 LT |
91 | } else { |
92 | /* router, no matching interface: just pick one */ | |
bb69ae04 ED |
93 | dev = dev_get_by_flags_rcu(net, IFF_UP, |
94 | IFF_UP | IFF_LOOPBACK); | |
1da177e4 LT |
95 | } |
96 | } else | |
bb69ae04 | 97 | dev = dev_get_by_index_rcu(net, ifindex); |
1da177e4 LT |
98 | |
99 | if (dev == NULL) { | |
100 | err = -ENODEV; | |
bb69ae04 | 101 | goto error; |
1da177e4 LT |
102 | } |
103 | ||
bb69ae04 | 104 | idev = __in6_dev_get(dev); |
1da177e4 LT |
105 | if (!idev) { |
106 | if (ifindex) | |
107 | err = -ENODEV; | |
108 | else | |
109 | err = -EADDRNOTAVAIL; | |
bb69ae04 | 110 | goto error; |
1da177e4 LT |
111 | } |
112 | /* reset ishost, now that we have a specific device */ | |
113 | ishost = !idev->cnf.forwarding; | |
1da177e4 LT |
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 | */ | |
52eeeb84 | 122 | if (!ipv6_chk_prefix(addr, dev)) { |
1da177e4 LT |
123 | if (ishost) |
124 | err = -EADDRNOTAVAIL; | |
125 | if (err) | |
bb69ae04 | 126 | goto error; |
1da177e4 LT |
127 | } |
128 | ||
129 | err = ipv6_dev_ac_inc(dev, addr); | |
bb69ae04 ED |
130 | if (!err) { |
131 | write_lock_bh(&ipv6_sk_ac_lock); | |
132 | pac->acl_next = np->ipv6_ac_list; | |
133 | np->ipv6_ac_list = pac; | |
134 | write_unlock_bh(&ipv6_sk_ac_lock); | |
135 | pac = NULL; | |
136 | } | |
1da177e4 | 137 | |
bb69ae04 ED |
138 | error: |
139 | rcu_read_unlock(); | |
140 | if (pac) | |
141 | sock_kfree_s(sk, pac, sizeof(*pac)); | |
1da177e4 LT |
142 | return err; |
143 | } | |
144 | ||
145 | /* | |
146 | * socket leave an anycast group | |
147 | */ | |
b71d1d42 | 148 | int ipv6_sock_ac_drop(struct sock *sk, int ifindex, const struct in6_addr *addr) |
1da177e4 LT |
149 | { |
150 | struct ipv6_pinfo *np = inet6_sk(sk); | |
151 | struct net_device *dev; | |
152 | struct ipv6_ac_socklist *pac, *prev_pac; | |
6ab57e7e | 153 | struct net *net = sock_net(sk); |
1da177e4 LT |
154 | |
155 | write_lock_bh(&ipv6_sk_ac_lock); | |
156 | prev_pac = NULL; | |
157 | for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) { | |
158 | if ((ifindex == 0 || pac->acl_ifindex == ifindex) && | |
159 | ipv6_addr_equal(&pac->acl_addr, addr)) | |
160 | break; | |
161 | prev_pac = pac; | |
162 | } | |
163 | if (!pac) { | |
164 | write_unlock_bh(&ipv6_sk_ac_lock); | |
165 | return -ENOENT; | |
166 | } | |
167 | if (prev_pac) | |
168 | prev_pac->acl_next = pac->acl_next; | |
169 | else | |
170 | np->ipv6_ac_list = pac->acl_next; | |
171 | ||
172 | write_unlock_bh(&ipv6_sk_ac_lock); | |
173 | ||
bb69ae04 ED |
174 | rcu_read_lock(); |
175 | dev = dev_get_by_index_rcu(net, pac->acl_ifindex); | |
176 | if (dev) | |
1da177e4 | 177 | ipv6_dev_ac_dec(dev, &pac->acl_addr); |
bb69ae04 ED |
178 | rcu_read_unlock(); |
179 | ||
1da177e4 LT |
180 | sock_kfree_s(sk, pac, sizeof(*pac)); |
181 | return 0; | |
182 | } | |
183 | ||
184 | void ipv6_sock_ac_close(struct sock *sk) | |
185 | { | |
186 | struct ipv6_pinfo *np = inet6_sk(sk); | |
187 | struct net_device *dev = NULL; | |
188 | struct ipv6_ac_socklist *pac; | |
6ab57e7e | 189 | struct net *net = sock_net(sk); |
1da177e4 LT |
190 | int prev_index; |
191 | ||
0e1efe9d ED |
192 | if (!np->ipv6_ac_list) |
193 | return; | |
194 | ||
1da177e4 LT |
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; | |
bb69ae04 | 201 | rcu_read_lock(); |
1da177e4 LT |
202 | while (pac) { |
203 | struct ipv6_ac_socklist *next = pac->acl_next; | |
204 | ||
205 | if (pac->acl_ifindex != prev_index) { | |
bb69ae04 | 206 | dev = dev_get_by_index_rcu(net, pac->acl_ifindex); |
1da177e4 LT |
207 | prev_index = pac->acl_ifindex; |
208 | } | |
209 | if (dev) | |
210 | ipv6_dev_ac_dec(dev, &pac->acl_addr); | |
211 | sock_kfree_s(sk, pac, sizeof(*pac)); | |
212 | pac = next; | |
213 | } | |
bb69ae04 | 214 | rcu_read_unlock(); |
1da177e4 LT |
215 | } |
216 | ||
1da177e4 LT |
217 | static void aca_put(struct ifacaddr6 *ac) |
218 | { | |
219 | if (atomic_dec_and_test(&ac->aca_refcnt)) { | |
220 | in6_dev_put(ac->aca_idev); | |
d8d1f30b | 221 | dst_release(&ac->aca_rt->dst); |
1da177e4 LT |
222 | kfree(ac); |
223 | } | |
224 | } | |
225 | ||
226 | /* | |
227 | * device anycast group inc (add if not found) | |
228 | */ | |
b71d1d42 | 229 | int ipv6_dev_ac_inc(struct net_device *dev, const struct in6_addr *addr) |
1da177e4 LT |
230 | { |
231 | struct ifacaddr6 *aca; | |
232 | struct inet6_dev *idev; | |
233 | struct rt6_info *rt; | |
234 | int err; | |
235 | ||
236 | idev = in6_dev_get(dev); | |
237 | ||
238 | if (idev == NULL) | |
239 | return -EINVAL; | |
240 | ||
241 | write_lock_bh(&idev->lock); | |
242 | if (idev->dead) { | |
243 | err = -ENODEV; | |
244 | goto out; | |
245 | } | |
246 | ||
247 | for (aca = idev->ac_list; aca; aca = aca->aca_next) { | |
248 | if (ipv6_addr_equal(&aca->aca_addr, addr)) { | |
249 | aca->aca_users++; | |
250 | err = 0; | |
251 | goto out; | |
252 | } | |
253 | } | |
254 | ||
255 | /* | |
256 | * not found: create a new one. | |
257 | */ | |
258 | ||
0c600eda | 259 | aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC); |
1da177e4 LT |
260 | |
261 | if (aca == NULL) { | |
262 | err = -ENOMEM; | |
263 | goto out; | |
264 | } | |
265 | ||
8f031519 | 266 | rt = addrconf_dst_alloc(idev, addr, true); |
1da177e4 LT |
267 | if (IS_ERR(rt)) { |
268 | kfree(aca); | |
269 | err = PTR_ERR(rt); | |
270 | goto out; | |
271 | } | |
272 | ||
4e3fd7a0 | 273 | aca->aca_addr = *addr; |
1da177e4 LT |
274 | aca->aca_idev = idev; |
275 | aca->aca_rt = rt; | |
276 | aca->aca_users = 1; | |
277 | /* aca_tstamp should be updated upon changes */ | |
278 | aca->aca_cstamp = aca->aca_tstamp = jiffies; | |
279 | atomic_set(&aca->aca_refcnt, 2); | |
280 | spin_lock_init(&aca->aca_lock); | |
281 | ||
282 | aca->aca_next = idev->ac_list; | |
283 | idev->ac_list = aca; | |
284 | write_unlock_bh(&idev->lock); | |
285 | ||
84f59370 | 286 | ip6_ins_rt(rt); |
1da177e4 LT |
287 | |
288 | addrconf_join_solict(dev, &aca->aca_addr); | |
289 | ||
290 | aca_put(aca); | |
291 | return 0; | |
292 | out: | |
293 | write_unlock_bh(&idev->lock); | |
294 | in6_dev_put(idev); | |
295 | return err; | |
296 | } | |
297 | ||
298 | /* | |
299 | * device anycast group decrement | |
300 | */ | |
b71d1d42 | 301 | int __ipv6_dev_ac_dec(struct inet6_dev *idev, const struct in6_addr *addr) |
1da177e4 LT |
302 | { |
303 | struct ifacaddr6 *aca, *prev_aca; | |
304 | ||
305 | write_lock_bh(&idev->lock); | |
306 | prev_aca = NULL; | |
307 | for (aca = idev->ac_list; aca; aca = aca->aca_next) { | |
308 | if (ipv6_addr_equal(&aca->aca_addr, addr)) | |
309 | break; | |
310 | prev_aca = aca; | |
311 | } | |
312 | if (!aca) { | |
313 | write_unlock_bh(&idev->lock); | |
314 | return -ENOENT; | |
315 | } | |
316 | if (--aca->aca_users > 0) { | |
317 | write_unlock_bh(&idev->lock); | |
318 | return 0; | |
319 | } | |
320 | if (prev_aca) | |
321 | prev_aca->aca_next = aca->aca_next; | |
322 | else | |
323 | idev->ac_list = aca->aca_next; | |
324 | write_unlock_bh(&idev->lock); | |
325 | addrconf_leave_solict(idev, &aca->aca_addr); | |
326 | ||
d8d1f30b | 327 | dst_hold(&aca->aca_rt->dst); |
84f59370 | 328 | ip6_del_rt(aca->aca_rt); |
1da177e4 LT |
329 | |
330 | aca_put(aca); | |
331 | return 0; | |
332 | } | |
333 | ||
bb69ae04 | 334 | /* called with rcu_read_lock() */ |
b71d1d42 | 335 | static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr) |
1da177e4 | 336 | { |
bb69ae04 ED |
337 | struct inet6_dev *idev = __in6_dev_get(dev); |
338 | ||
1da177e4 LT |
339 | if (idev == NULL) |
340 | return -ENODEV; | |
bb69ae04 | 341 | return __ipv6_dev_ac_dec(idev, addr); |
1da177e4 | 342 | } |
1ab1457c | 343 | |
1da177e4 LT |
344 | /* |
345 | * check if the interface has this anycast address | |
bb69ae04 | 346 | * called with rcu_read_lock() |
1da177e4 | 347 | */ |
a50feda5 | 348 | static bool ipv6_chk_acast_dev(struct net_device *dev, const struct in6_addr *addr) |
1da177e4 LT |
349 | { |
350 | struct inet6_dev *idev; | |
351 | struct ifacaddr6 *aca; | |
352 | ||
bb69ae04 | 353 | idev = __in6_dev_get(dev); |
1da177e4 LT |
354 | if (idev) { |
355 | read_lock_bh(&idev->lock); | |
356 | for (aca = idev->ac_list; aca; aca = aca->aca_next) | |
357 | if (ipv6_addr_equal(&aca->aca_addr, addr)) | |
358 | break; | |
359 | read_unlock_bh(&idev->lock); | |
cfcabdcc | 360 | return aca != NULL; |
1da177e4 | 361 | } |
a50feda5 | 362 | return false; |
1da177e4 LT |
363 | } |
364 | ||
365 | /* | |
366 | * check if given interface (or any, if dev==0) has this anycast address | |
367 | */ | |
a50feda5 ED |
368 | bool ipv6_chk_acast_addr(struct net *net, struct net_device *dev, |
369 | const struct in6_addr *addr) | |
1da177e4 | 370 | { |
a50feda5 | 371 | bool found = false; |
7562f876 | 372 | |
c6d14c84 | 373 | rcu_read_lock(); |
bb69ae04 ED |
374 | if (dev) |
375 | found = ipv6_chk_acast_dev(dev, addr); | |
376 | else | |
377 | for_each_netdev_rcu(net, dev) | |
378 | if (ipv6_chk_acast_dev(dev, addr)) { | |
a50feda5 | 379 | found = true; |
bb69ae04 ED |
380 | break; |
381 | } | |
c6d14c84 | 382 | rcu_read_unlock(); |
7562f876 | 383 | return found; |
1da177e4 LT |
384 | } |
385 | ||
386 | ||
387 | #ifdef CONFIG_PROC_FS | |
388 | struct ac6_iter_state { | |
6ab57e7e | 389 | struct seq_net_private p; |
1da177e4 LT |
390 | struct net_device *dev; |
391 | struct inet6_dev *idev; | |
392 | }; | |
393 | ||
394 | #define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private) | |
395 | ||
396 | static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq) | |
397 | { | |
398 | struct ifacaddr6 *im = NULL; | |
399 | struct ac6_iter_state *state = ac6_seq_private(seq); | |
6ab57e7e | 400 | struct net *net = seq_file_net(seq); |
1da177e4 | 401 | |
7562f876 | 402 | state->idev = NULL; |
ce81b76a | 403 | for_each_netdev_rcu(net, state->dev) { |
1da177e4 | 404 | struct inet6_dev *idev; |
ce81b76a | 405 | idev = __in6_dev_get(state->dev); |
1da177e4 LT |
406 | if (!idev) |
407 | continue; | |
408 | read_lock_bh(&idev->lock); | |
409 | im = idev->ac_list; | |
410 | if (im) { | |
411 | state->idev = idev; | |
412 | break; | |
413 | } | |
414 | read_unlock_bh(&idev->lock); | |
415 | } | |
416 | return im; | |
417 | } | |
418 | ||
419 | static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im) | |
420 | { | |
421 | struct ac6_iter_state *state = ac6_seq_private(seq); | |
422 | ||
423 | im = im->aca_next; | |
424 | while (!im) { | |
ce81b76a | 425 | if (likely(state->idev != NULL)) |
1da177e4 | 426 | read_unlock_bh(&state->idev->lock); |
ce81b76a ED |
427 | |
428 | state->dev = next_net_device_rcu(state->dev); | |
1da177e4 LT |
429 | if (!state->dev) { |
430 | state->idev = NULL; | |
431 | break; | |
432 | } | |
ce81b76a | 433 | state->idev = __in6_dev_get(state->dev); |
1da177e4 LT |
434 | if (!state->idev) |
435 | continue; | |
436 | read_lock_bh(&state->idev->lock); | |
437 | im = state->idev->ac_list; | |
438 | } | |
439 | return im; | |
440 | } | |
441 | ||
442 | static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos) | |
443 | { | |
444 | struct ifacaddr6 *im = ac6_get_first(seq); | |
445 | if (im) | |
446 | while (pos && (im = ac6_get_next(seq, im)) != NULL) | |
447 | --pos; | |
448 | return pos ? NULL : im; | |
449 | } | |
450 | ||
451 | static void *ac6_seq_start(struct seq_file *seq, loff_t *pos) | |
ce81b76a | 452 | __acquires(RCU) |
1da177e4 | 453 | { |
ce81b76a | 454 | rcu_read_lock(); |
1da177e4 LT |
455 | return ac6_get_idx(seq, *pos); |
456 | } | |
457 | ||
458 | static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
459 | { | |
ce81b76a ED |
460 | struct ifacaddr6 *im = ac6_get_next(seq, v); |
461 | ||
1da177e4 LT |
462 | ++*pos; |
463 | return im; | |
464 | } | |
465 | ||
466 | static void ac6_seq_stop(struct seq_file *seq, void *v) | |
ce81b76a | 467 | __releases(RCU) |
1da177e4 LT |
468 | { |
469 | struct ac6_iter_state *state = ac6_seq_private(seq); | |
ce81b76a | 470 | |
1da177e4 LT |
471 | if (likely(state->idev != NULL)) { |
472 | read_unlock_bh(&state->idev->lock); | |
ce81b76a | 473 | state->idev = NULL; |
1da177e4 | 474 | } |
ce81b76a | 475 | rcu_read_unlock(); |
1da177e4 LT |
476 | } |
477 | ||
478 | static int ac6_seq_show(struct seq_file *seq, void *v) | |
479 | { | |
480 | struct ifacaddr6 *im = (struct ifacaddr6 *)v; | |
481 | struct ac6_iter_state *state = ac6_seq_private(seq); | |
482 | ||
4b7a4274 | 483 | seq_printf(seq, "%-4d %-15s %pi6 %5d\n", |
1da177e4 | 484 | state->dev->ifindex, state->dev->name, |
b071195d | 485 | &im->aca_addr, im->aca_users); |
1da177e4 LT |
486 | return 0; |
487 | } | |
488 | ||
56b3d975 | 489 | static const struct seq_operations ac6_seq_ops = { |
1da177e4 LT |
490 | .start = ac6_seq_start, |
491 | .next = ac6_seq_next, | |
492 | .stop = ac6_seq_stop, | |
493 | .show = ac6_seq_show, | |
494 | }; | |
495 | ||
496 | static int ac6_seq_open(struct inode *inode, struct file *file) | |
497 | { | |
6ab57e7e DL |
498 | return seq_open_net(inode, file, &ac6_seq_ops, |
499 | sizeof(struct ac6_iter_state)); | |
1da177e4 LT |
500 | } |
501 | ||
9a32144e | 502 | static const struct file_operations ac6_seq_fops = { |
1da177e4 LT |
503 | .owner = THIS_MODULE, |
504 | .open = ac6_seq_open, | |
505 | .read = seq_read, | |
506 | .llseek = seq_lseek, | |
6ab57e7e | 507 | .release = seq_release_net, |
1da177e4 LT |
508 | }; |
509 | ||
2c8c1e72 | 510 | int __net_init ac6_proc_init(struct net *net) |
1da177e4 | 511 | { |
6ab57e7e | 512 | if (!proc_net_fops_create(net, "anycast6", S_IRUGO, &ac6_seq_fops)) |
1da177e4 LT |
513 | return -ENOMEM; |
514 | ||
515 | return 0; | |
516 | } | |
517 | ||
6ab57e7e | 518 | void ac6_proc_exit(struct net *net) |
1da177e4 | 519 | { |
6ab57e7e | 520 | proc_net_remove(net, "anycast6"); |
1da177e4 LT |
521 | } |
522 | #endif | |
523 |