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1da177e4 LT |
1 | /* |
2 | * Anycast support for IPv6 | |
3 | * Linux INET6 implementation | |
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/config.h> |
18 | #include <linux/module.h> | |
19 | #include <linux/errno.h> | |
20 | #include <linux/types.h> | |
21 | #include <linux/random.h> | |
22 | #include <linux/string.h> | |
23 | #include <linux/socket.h> | |
24 | #include <linux/sockios.h> | |
25 | #include <linux/sched.h> | |
26 | #include <linux/net.h> | |
27 | #include <linux/in6.h> | |
28 | #include <linux/netdevice.h> | |
29 | #include <linux/if_arp.h> | |
30 | #include <linux/route.h> | |
31 | #include <linux/init.h> | |
32 | #include <linux/proc_fs.h> | |
33 | #include <linux/seq_file.h> | |
34 | ||
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 | ||
52 | static int | |
53 | ip6_onlink(struct in6_addr *addr, struct net_device *dev) | |
54 | { | |
55 | struct inet6_dev *idev; | |
56 | struct inet6_ifaddr *ifa; | |
57 | int onlink; | |
58 | ||
59 | onlink = 0; | |
60 | read_lock(&addrconf_lock); | |
61 | idev = __in6_dev_get(dev); | |
62 | if (idev) { | |
63 | read_lock_bh(&idev->lock); | |
64 | for (ifa=idev->addr_list; ifa; ifa=ifa->if_next) { | |
65 | onlink = ipv6_prefix_equal(addr, &ifa->addr, | |
66 | ifa->prefix_len); | |
67 | if (onlink) | |
68 | break; | |
69 | } | |
70 | read_unlock_bh(&idev->lock); | |
71 | } | |
72 | read_unlock(&addrconf_lock); | |
73 | return onlink; | |
74 | } | |
75 | ||
76 | /* | |
77 | * socket join an anycast group | |
78 | */ | |
79 | ||
80 | int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr) | |
81 | { | |
82 | struct ipv6_pinfo *np = inet6_sk(sk); | |
83 | struct net_device *dev = NULL; | |
84 | struct inet6_dev *idev; | |
85 | struct ipv6_ac_socklist *pac; | |
86 | int ishost = !ipv6_devconf.forwarding; | |
87 | int err = 0; | |
88 | ||
89 | if (!capable(CAP_NET_ADMIN)) | |
90 | return -EPERM; | |
91 | if (ipv6_addr_is_multicast(addr)) | |
92 | return -EINVAL; | |
93 | if (ipv6_chk_addr(addr, NULL, 0)) | |
94 | return -EINVAL; | |
95 | ||
96 | pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL); | |
97 | if (pac == NULL) | |
98 | return -ENOMEM; | |
99 | pac->acl_next = NULL; | |
100 | ipv6_addr_copy(&pac->acl_addr, addr); | |
101 | ||
102 | if (ifindex == 0) { | |
103 | struct rt6_info *rt; | |
104 | ||
105 | rt = rt6_lookup(addr, NULL, 0, 0); | |
106 | if (rt) { | |
107 | dev = rt->rt6i_dev; | |
108 | dev_hold(dev); | |
109 | dst_release(&rt->u.dst); | |
110 | } else if (ishost) { | |
111 | err = -EADDRNOTAVAIL; | |
112 | goto out_free_pac; | |
113 | } else { | |
114 | /* router, no matching interface: just pick one */ | |
115 | ||
116 | dev = dev_get_by_flags(IFF_UP, IFF_UP|IFF_LOOPBACK); | |
117 | } | |
118 | } else | |
119 | dev = dev_get_by_index(ifindex); | |
120 | ||
121 | if (dev == NULL) { | |
122 | err = -ENODEV; | |
123 | goto out_free_pac; | |
124 | } | |
125 | ||
126 | idev = in6_dev_get(dev); | |
127 | if (!idev) { | |
128 | if (ifindex) | |
129 | err = -ENODEV; | |
130 | else | |
131 | err = -EADDRNOTAVAIL; | |
132 | goto out_dev_put; | |
133 | } | |
134 | /* reset ishost, now that we have a specific device */ | |
135 | ishost = !idev->cnf.forwarding; | |
136 | in6_dev_put(idev); | |
137 | ||
138 | pac->acl_ifindex = dev->ifindex; | |
139 | ||
140 | /* XXX | |
141 | * For hosts, allow link-local or matching prefix anycasts. | |
142 | * This obviates the need for propagating anycast routes while | |
143 | * still allowing some non-router anycast participation. | |
144 | */ | |
145 | if (!ip6_onlink(addr, dev)) { | |
146 | if (ishost) | |
147 | err = -EADDRNOTAVAIL; | |
148 | if (err) | |
149 | goto out_dev_put; | |
150 | } | |
151 | ||
152 | err = ipv6_dev_ac_inc(dev, addr); | |
153 | if (err) | |
154 | goto out_dev_put; | |
155 | ||
156 | write_lock_bh(&ipv6_sk_ac_lock); | |
157 | pac->acl_next = np->ipv6_ac_list; | |
158 | np->ipv6_ac_list = pac; | |
159 | write_unlock_bh(&ipv6_sk_ac_lock); | |
160 | ||
161 | dev_put(dev); | |
162 | ||
163 | return 0; | |
164 | ||
165 | out_dev_put: | |
166 | dev_put(dev); | |
167 | out_free_pac: | |
168 | sock_kfree_s(sk, pac, sizeof(*pac)); | |
169 | return err; | |
170 | } | |
171 | ||
172 | /* | |
173 | * socket leave an anycast group | |
174 | */ | |
175 | int ipv6_sock_ac_drop(struct sock *sk, int ifindex, struct in6_addr *addr) | |
176 | { | |
177 | struct ipv6_pinfo *np = inet6_sk(sk); | |
178 | struct net_device *dev; | |
179 | struct ipv6_ac_socklist *pac, *prev_pac; | |
180 | ||
181 | write_lock_bh(&ipv6_sk_ac_lock); | |
182 | prev_pac = NULL; | |
183 | for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) { | |
184 | if ((ifindex == 0 || pac->acl_ifindex == ifindex) && | |
185 | ipv6_addr_equal(&pac->acl_addr, addr)) | |
186 | break; | |
187 | prev_pac = pac; | |
188 | } | |
189 | if (!pac) { | |
190 | write_unlock_bh(&ipv6_sk_ac_lock); | |
191 | return -ENOENT; | |
192 | } | |
193 | if (prev_pac) | |
194 | prev_pac->acl_next = pac->acl_next; | |
195 | else | |
196 | np->ipv6_ac_list = pac->acl_next; | |
197 | ||
198 | write_unlock_bh(&ipv6_sk_ac_lock); | |
199 | ||
200 | dev = dev_get_by_index(pac->acl_ifindex); | |
201 | if (dev) { | |
202 | ipv6_dev_ac_dec(dev, &pac->acl_addr); | |
203 | dev_put(dev); | |
204 | } | |
205 | sock_kfree_s(sk, pac, sizeof(*pac)); | |
206 | return 0; | |
207 | } | |
208 | ||
209 | void ipv6_sock_ac_close(struct sock *sk) | |
210 | { | |
211 | struct ipv6_pinfo *np = inet6_sk(sk); | |
212 | struct net_device *dev = NULL; | |
213 | struct ipv6_ac_socklist *pac; | |
214 | int prev_index; | |
215 | ||
216 | write_lock_bh(&ipv6_sk_ac_lock); | |
217 | pac = np->ipv6_ac_list; | |
218 | np->ipv6_ac_list = NULL; | |
219 | write_unlock_bh(&ipv6_sk_ac_lock); | |
220 | ||
221 | prev_index = 0; | |
222 | while (pac) { | |
223 | struct ipv6_ac_socklist *next = pac->acl_next; | |
224 | ||
225 | if (pac->acl_ifindex != prev_index) { | |
226 | if (dev) | |
227 | dev_put(dev); | |
228 | dev = dev_get_by_index(pac->acl_ifindex); | |
229 | prev_index = pac->acl_ifindex; | |
230 | } | |
231 | if (dev) | |
232 | ipv6_dev_ac_dec(dev, &pac->acl_addr); | |
233 | sock_kfree_s(sk, pac, sizeof(*pac)); | |
234 | pac = next; | |
235 | } | |
236 | if (dev) | |
237 | dev_put(dev); | |
238 | } | |
239 | ||
240 | #if 0 | |
241 | /* The function is not used, which is funny. Apparently, author | |
242 | * supposed to use it to filter out datagrams inside udp/raw but forgot. | |
243 | * | |
244 | * It is OK, anycasts are not special comparing to delivery to unicasts. | |
245 | */ | |
246 | ||
247 | int inet6_ac_check(struct sock *sk, struct in6_addr *addr, int ifindex) | |
248 | { | |
249 | struct ipv6_ac_socklist *pac; | |
250 | struct ipv6_pinfo *np = inet6_sk(sk); | |
251 | int found; | |
252 | ||
253 | found = 0; | |
254 | read_lock(&ipv6_sk_ac_lock); | |
255 | for (pac=np->ipv6_ac_list; pac; pac=pac->acl_next) { | |
256 | if (ifindex && pac->acl_ifindex != ifindex) | |
257 | continue; | |
258 | found = ipv6_addr_equal(&pac->acl_addr, addr); | |
259 | if (found) | |
260 | break; | |
261 | } | |
262 | read_unlock(&ipv6_sk_ac_lock); | |
263 | ||
264 | return found; | |
265 | } | |
266 | ||
267 | #endif | |
268 | ||
269 | static void aca_put(struct ifacaddr6 *ac) | |
270 | { | |
271 | if (atomic_dec_and_test(&ac->aca_refcnt)) { | |
272 | in6_dev_put(ac->aca_idev); | |
273 | dst_release(&ac->aca_rt->u.dst); | |
274 | kfree(ac); | |
275 | } | |
276 | } | |
277 | ||
278 | /* | |
279 | * device anycast group inc (add if not found) | |
280 | */ | |
281 | int ipv6_dev_ac_inc(struct net_device *dev, struct in6_addr *addr) | |
282 | { | |
283 | struct ifacaddr6 *aca; | |
284 | struct inet6_dev *idev; | |
285 | struct rt6_info *rt; | |
286 | int err; | |
287 | ||
288 | idev = in6_dev_get(dev); | |
289 | ||
290 | if (idev == NULL) | |
291 | return -EINVAL; | |
292 | ||
293 | write_lock_bh(&idev->lock); | |
294 | if (idev->dead) { | |
295 | err = -ENODEV; | |
296 | goto out; | |
297 | } | |
298 | ||
299 | for (aca = idev->ac_list; aca; aca = aca->aca_next) { | |
300 | if (ipv6_addr_equal(&aca->aca_addr, addr)) { | |
301 | aca->aca_users++; | |
302 | err = 0; | |
303 | goto out; | |
304 | } | |
305 | } | |
306 | ||
307 | /* | |
308 | * not found: create a new one. | |
309 | */ | |
310 | ||
311 | aca = kmalloc(sizeof(struct ifacaddr6), GFP_ATOMIC); | |
312 | ||
313 | if (aca == NULL) { | |
314 | err = -ENOMEM; | |
315 | goto out; | |
316 | } | |
317 | ||
318 | rt = addrconf_dst_alloc(idev, addr, 1); | |
319 | if (IS_ERR(rt)) { | |
320 | kfree(aca); | |
321 | err = PTR_ERR(rt); | |
322 | goto out; | |
323 | } | |
324 | ||
325 | memset(aca, 0, sizeof(struct ifacaddr6)); | |
326 | ||
327 | ipv6_addr_copy(&aca->aca_addr, addr); | |
328 | aca->aca_idev = idev; | |
329 | aca->aca_rt = rt; | |
330 | aca->aca_users = 1; | |
331 | /* aca_tstamp should be updated upon changes */ | |
332 | aca->aca_cstamp = aca->aca_tstamp = jiffies; | |
333 | atomic_set(&aca->aca_refcnt, 2); | |
334 | spin_lock_init(&aca->aca_lock); | |
335 | ||
336 | aca->aca_next = idev->ac_list; | |
337 | idev->ac_list = aca; | |
338 | write_unlock_bh(&idev->lock); | |
339 | ||
340 | dst_hold(&rt->u.dst); | |
0d51aa80 | 341 | if (ip6_ins_rt(rt, NULL, NULL, NULL)) |
1da177e4 LT |
342 | dst_release(&rt->u.dst); |
343 | ||
344 | addrconf_join_solict(dev, &aca->aca_addr); | |
345 | ||
346 | aca_put(aca); | |
347 | return 0; | |
348 | out: | |
349 | write_unlock_bh(&idev->lock); | |
350 | in6_dev_put(idev); | |
351 | return err; | |
352 | } | |
353 | ||
354 | /* | |
355 | * device anycast group decrement | |
356 | */ | |
357 | int __ipv6_dev_ac_dec(struct inet6_dev *idev, struct in6_addr *addr) | |
358 | { | |
359 | struct ifacaddr6 *aca, *prev_aca; | |
360 | ||
361 | write_lock_bh(&idev->lock); | |
362 | prev_aca = NULL; | |
363 | for (aca = idev->ac_list; aca; aca = aca->aca_next) { | |
364 | if (ipv6_addr_equal(&aca->aca_addr, addr)) | |
365 | break; | |
366 | prev_aca = aca; | |
367 | } | |
368 | if (!aca) { | |
369 | write_unlock_bh(&idev->lock); | |
370 | return -ENOENT; | |
371 | } | |
372 | if (--aca->aca_users > 0) { | |
373 | write_unlock_bh(&idev->lock); | |
374 | return 0; | |
375 | } | |
376 | if (prev_aca) | |
377 | prev_aca->aca_next = aca->aca_next; | |
378 | else | |
379 | idev->ac_list = aca->aca_next; | |
380 | write_unlock_bh(&idev->lock); | |
381 | addrconf_leave_solict(idev, &aca->aca_addr); | |
382 | ||
383 | dst_hold(&aca->aca_rt->u.dst); | |
0d51aa80 | 384 | if (ip6_del_rt(aca->aca_rt, NULL, NULL, NULL)) |
1da177e4 LT |
385 | dst_free(&aca->aca_rt->u.dst); |
386 | else | |
387 | dst_release(&aca->aca_rt->u.dst); | |
388 | ||
389 | aca_put(aca); | |
390 | return 0; | |
391 | } | |
392 | ||
393 | static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr) | |
394 | { | |
395 | int ret; | |
396 | struct inet6_dev *idev = in6_dev_get(dev); | |
397 | if (idev == NULL) | |
398 | return -ENODEV; | |
399 | ret = __ipv6_dev_ac_dec(idev, addr); | |
400 | in6_dev_put(idev); | |
401 | return ret; | |
402 | } | |
403 | ||
404 | /* | |
405 | * check if the interface has this anycast address | |
406 | */ | |
407 | static int ipv6_chk_acast_dev(struct net_device *dev, struct in6_addr *addr) | |
408 | { | |
409 | struct inet6_dev *idev; | |
410 | struct ifacaddr6 *aca; | |
411 | ||
412 | idev = in6_dev_get(dev); | |
413 | if (idev) { | |
414 | read_lock_bh(&idev->lock); | |
415 | for (aca = idev->ac_list; aca; aca = aca->aca_next) | |
416 | if (ipv6_addr_equal(&aca->aca_addr, addr)) | |
417 | break; | |
418 | read_unlock_bh(&idev->lock); | |
419 | in6_dev_put(idev); | |
420 | return aca != 0; | |
421 | } | |
422 | return 0; | |
423 | } | |
424 | ||
425 | /* | |
426 | * check if given interface (or any, if dev==0) has this anycast address | |
427 | */ | |
428 | int ipv6_chk_acast_addr(struct net_device *dev, struct in6_addr *addr) | |
429 | { | |
430 | if (dev) | |
431 | return ipv6_chk_acast_dev(dev, addr); | |
432 | read_lock(&dev_base_lock); | |
433 | for (dev=dev_base; dev; dev=dev->next) | |
434 | if (ipv6_chk_acast_dev(dev, addr)) | |
435 | break; | |
436 | read_unlock(&dev_base_lock); | |
437 | return dev != 0; | |
438 | } | |
439 | ||
440 | ||
441 | #ifdef CONFIG_PROC_FS | |
442 | struct 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 | ||
449 | static 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 | ||
454 | for (state->dev = dev_base, state->idev = NULL; | |
455 | state->dev; | |
456 | state->dev = state->dev->next) { | |
457 | struct inet6_dev *idev; | |
458 | idev = in6_dev_get(state->dev); | |
459 | if (!idev) | |
460 | continue; | |
461 | read_lock_bh(&idev->lock); | |
462 | im = idev->ac_list; | |
463 | if (im) { | |
464 | state->idev = idev; | |
465 | break; | |
466 | } | |
467 | read_unlock_bh(&idev->lock); | |
468 | } | |
469 | return im; | |
470 | } | |
471 | ||
472 | static 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 | } | |
482 | state->dev = state->dev->next; | |
483 | 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 | ||
496 | static 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 | ||
505 | static 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 | ||
511 | static 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 | ||
519 | static 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 | ||
529 | static 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, | |
9343e79a | 535 | "%-4d %-15s " NIP6_SEQFMT " %5d\n", |
1da177e4 LT |
536 | state->dev->ifindex, state->dev->name, |
537 | NIP6(im->aca_addr), | |
538 | im->aca_users); | |
539 | return 0; | |
540 | } | |
541 | ||
542 | static struct seq_operations ac6_seq_ops = { | |
543 | .start = ac6_seq_start, | |
544 | .next = ac6_seq_next, | |
545 | .stop = ac6_seq_stop, | |
546 | .show = ac6_seq_show, | |
547 | }; | |
548 | ||
549 | static int ac6_seq_open(struct inode *inode, struct file *file) | |
550 | { | |
551 | struct seq_file *seq; | |
552 | int rc = -ENOMEM; | |
553 | struct ac6_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL); | |
554 | ||
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; | |
564 | memset(s, 0, sizeof(*s)); | |
565 | out: | |
566 | return rc; | |
567 | out_kfree: | |
568 | kfree(s); | |
569 | goto out; | |
570 | } | |
571 | ||
572 | static struct file_operations ac6_seq_fops = { | |
573 | .owner = THIS_MODULE, | |
574 | .open = ac6_seq_open, | |
575 | .read = seq_read, | |
576 | .llseek = seq_lseek, | |
577 | .release = seq_release_private, | |
578 | }; | |
579 | ||
580 | int __init ac6_proc_init(void) | |
581 | { | |
582 | if (!proc_net_fops_create("anycast6", S_IRUGO, &ac6_seq_fops)) | |
583 | return -ENOMEM; | |
584 | ||
585 | return 0; | |
586 | } | |
587 | ||
588 | void ac6_proc_exit(void) | |
589 | { | |
590 | proc_net_remove("anycast6"); | |
591 | } | |
592 | #endif | |
593 |