blob: 6b7294047238387ea6c20420938f8b46990c057b [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
16#include <linux/config.h>
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>
24#include <linux/sched.h>
25#include <linux/net.h>
26#include <linux/in6.h>
27#include <linux/netdevice.h>
28#include <linux/if_arp.h>
29#include <linux/route.h>
30#include <linux/init.h>
31#include <linux/proc_fs.h>
32#include <linux/seq_file.h>
33
34#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
51static int
52ip6_onlink(struct in6_addr *addr, struct net_device *dev)
53{
54 struct inet6_dev *idev;
55 struct inet6_ifaddr *ifa;
56 int onlink;
57
58 onlink = 0;
59 read_lock(&addrconf_lock);
60 idev = __in6_dev_get(dev);
61 if (idev) {
62 read_lock_bh(&idev->lock);
63 for (ifa=idev->addr_list; ifa; ifa=ifa->if_next) {
64 onlink = ipv6_prefix_equal(addr, &ifa->addr,
65 ifa->prefix_len);
66 if (onlink)
67 break;
68 }
69 read_unlock_bh(&idev->lock);
70 }
71 read_unlock(&addrconf_lock);
72 return onlink;
73}
74
75/*
76 * socket join an anycast group
77 */
78
79int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr)
80{
81 struct ipv6_pinfo *np = inet6_sk(sk);
82 struct net_device *dev = NULL;
83 struct inet6_dev *idev;
84 struct ipv6_ac_socklist *pac;
85 int ishost = !ipv6_devconf.forwarding;
86 int err = 0;
87
88 if (!capable(CAP_NET_ADMIN))
89 return -EPERM;
90 if (ipv6_addr_is_multicast(addr))
91 return -EINVAL;
92 if (ipv6_chk_addr(addr, NULL, 0))
93 return -EINVAL;
94
95 pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
96 if (pac == NULL)
97 return -ENOMEM;
98 pac->acl_next = NULL;
99 ipv6_addr_copy(&pac->acl_addr, addr);
100
101 if (ifindex == 0) {
102 struct rt6_info *rt;
103
104 rt = rt6_lookup(addr, NULL, 0, 0);
105 if (rt) {
106 dev = rt->rt6i_dev;
107 dev_hold(dev);
108 dst_release(&rt->u.dst);
109 } else if (ishost) {
110 err = -EADDRNOTAVAIL;
111 goto out_free_pac;
112 } else {
113 /* router, no matching interface: just pick one */
114
115 dev = dev_get_by_flags(IFF_UP, IFF_UP|IFF_LOOPBACK);
116 }
117 } else
118 dev = dev_get_by_index(ifindex);
119
120 if (dev == NULL) {
121 err = -ENODEV;
122 goto out_free_pac;
123 }
124
125 idev = in6_dev_get(dev);
126 if (!idev) {
127 if (ifindex)
128 err = -ENODEV;
129 else
130 err = -EADDRNOTAVAIL;
131 goto out_dev_put;
132 }
133 /* reset ishost, now that we have a specific device */
134 ishost = !idev->cnf.forwarding;
135 in6_dev_put(idev);
136
137 pac->acl_ifindex = dev->ifindex;
138
139 /* XXX
140 * For hosts, allow link-local or matching prefix anycasts.
141 * This obviates the need for propagating anycast routes while
142 * still allowing some non-router anycast participation.
143 */
144 if (!ip6_onlink(addr, dev)) {
145 if (ishost)
146 err = -EADDRNOTAVAIL;
147 if (err)
148 goto out_dev_put;
149 }
150
151 err = ipv6_dev_ac_inc(dev, addr);
152 if (err)
153 goto out_dev_put;
154
155 write_lock_bh(&ipv6_sk_ac_lock);
156 pac->acl_next = np->ipv6_ac_list;
157 np->ipv6_ac_list = pac;
158 write_unlock_bh(&ipv6_sk_ac_lock);
159
160 dev_put(dev);
161
162 return 0;
163
164out_dev_put:
165 dev_put(dev);
166out_free_pac:
167 sock_kfree_s(sk, pac, sizeof(*pac));
168 return err;
169}
170
171/*
172 * socket leave an anycast group
173 */
174int ipv6_sock_ac_drop(struct sock *sk, int ifindex, struct in6_addr *addr)
175{
176 struct ipv6_pinfo *np = inet6_sk(sk);
177 struct net_device *dev;
178 struct ipv6_ac_socklist *pac, *prev_pac;
179
180 write_lock_bh(&ipv6_sk_ac_lock);
181 prev_pac = NULL;
182 for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
183 if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
184 ipv6_addr_equal(&pac->acl_addr, addr))
185 break;
186 prev_pac = pac;
187 }
188 if (!pac) {
189 write_unlock_bh(&ipv6_sk_ac_lock);
190 return -ENOENT;
191 }
192 if (prev_pac)
193 prev_pac->acl_next = pac->acl_next;
194 else
195 np->ipv6_ac_list = pac->acl_next;
196
197 write_unlock_bh(&ipv6_sk_ac_lock);
198
199 dev = dev_get_by_index(pac->acl_ifindex);
200 if (dev) {
201 ipv6_dev_ac_dec(dev, &pac->acl_addr);
202 dev_put(dev);
203 }
204 sock_kfree_s(sk, pac, sizeof(*pac));
205 return 0;
206}
207
208void ipv6_sock_ac_close(struct sock *sk)
209{
210 struct ipv6_pinfo *np = inet6_sk(sk);
211 struct net_device *dev = NULL;
212 struct ipv6_ac_socklist *pac;
213 int prev_index;
214
215 write_lock_bh(&ipv6_sk_ac_lock);
216 pac = np->ipv6_ac_list;
217 np->ipv6_ac_list = NULL;
218 write_unlock_bh(&ipv6_sk_ac_lock);
219
220 prev_index = 0;
221 while (pac) {
222 struct ipv6_ac_socklist *next = pac->acl_next;
223
224 if (pac->acl_ifindex != prev_index) {
225 if (dev)
226 dev_put(dev);
227 dev = dev_get_by_index(pac->acl_ifindex);
228 prev_index = pac->acl_ifindex;
229 }
230 if (dev)
231 ipv6_dev_ac_dec(dev, &pac->acl_addr);
232 sock_kfree_s(sk, pac, sizeof(*pac));
233 pac = next;
234 }
235 if (dev)
236 dev_put(dev);
237}
238
239#if 0
240/* The function is not used, which is funny. Apparently, author
241 * supposed to use it to filter out datagrams inside udp/raw but forgot.
242 *
243 * It is OK, anycasts are not special comparing to delivery to unicasts.
244 */
245
246int inet6_ac_check(struct sock *sk, struct in6_addr *addr, int ifindex)
247{
248 struct ipv6_ac_socklist *pac;
249 struct ipv6_pinfo *np = inet6_sk(sk);
250 int found;
251
252 found = 0;
253 read_lock(&ipv6_sk_ac_lock);
254 for (pac=np->ipv6_ac_list; pac; pac=pac->acl_next) {
255 if (ifindex && pac->acl_ifindex != ifindex)
256 continue;
257 found = ipv6_addr_equal(&pac->acl_addr, addr);
258 if (found)
259 break;
260 }
261 read_unlock(&ipv6_sk_ac_lock);
262
263 return found;
264}
265
266#endif
267
268static void aca_put(struct ifacaddr6 *ac)
269{
270 if (atomic_dec_and_test(&ac->aca_refcnt)) {
271 in6_dev_put(ac->aca_idev);
272 dst_release(&ac->aca_rt->u.dst);
273 kfree(ac);
274 }
275}
276
277/*
278 * device anycast group inc (add if not found)
279 */
280int ipv6_dev_ac_inc(struct net_device *dev, struct in6_addr *addr)
281{
282 struct ifacaddr6 *aca;
283 struct inet6_dev *idev;
284 struct rt6_info *rt;
285 int err;
286
287 idev = in6_dev_get(dev);
288
289 if (idev == NULL)
290 return -EINVAL;
291
292 write_lock_bh(&idev->lock);
293 if (idev->dead) {
294 err = -ENODEV;
295 goto out;
296 }
297
298 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
299 if (ipv6_addr_equal(&aca->aca_addr, addr)) {
300 aca->aca_users++;
301 err = 0;
302 goto out;
303 }
304 }
305
306 /*
307 * not found: create a new one.
308 */
309
310 aca = kmalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
311
312 if (aca == NULL) {
313 err = -ENOMEM;
314 goto out;
315 }
316
317 rt = addrconf_dst_alloc(idev, addr, 1);
318 if (IS_ERR(rt)) {
319 kfree(aca);
320 err = PTR_ERR(rt);
321 goto out;
322 }
323
324 memset(aca, 0, sizeof(struct ifacaddr6));
325
326 ipv6_addr_copy(&aca->aca_addr, addr);
327 aca->aca_idev = idev;
328 aca->aca_rt = rt;
329 aca->aca_users = 1;
330 /* aca_tstamp should be updated upon changes */
331 aca->aca_cstamp = aca->aca_tstamp = jiffies;
332 atomic_set(&aca->aca_refcnt, 2);
333 spin_lock_init(&aca->aca_lock);
334
335 aca->aca_next = idev->ac_list;
336 idev->ac_list = aca;
337 write_unlock_bh(&idev->lock);
338
339 dst_hold(&rt->u.dst);
Jamal Hadi Salim0d51aa82005-06-21 13:51:04 -0700340 if (ip6_ins_rt(rt, NULL, NULL, NULL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 dst_release(&rt->u.dst);
342
343 addrconf_join_solict(dev, &aca->aca_addr);
344
345 aca_put(aca);
346 return 0;
347out:
348 write_unlock_bh(&idev->lock);
349 in6_dev_put(idev);
350 return err;
351}
352
353/*
354 * device anycast group decrement
355 */
356int __ipv6_dev_ac_dec(struct inet6_dev *idev, struct in6_addr *addr)
357{
358 struct ifacaddr6 *aca, *prev_aca;
359
360 write_lock_bh(&idev->lock);
361 prev_aca = NULL;
362 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
363 if (ipv6_addr_equal(&aca->aca_addr, addr))
364 break;
365 prev_aca = aca;
366 }
367 if (!aca) {
368 write_unlock_bh(&idev->lock);
369 return -ENOENT;
370 }
371 if (--aca->aca_users > 0) {
372 write_unlock_bh(&idev->lock);
373 return 0;
374 }
375 if (prev_aca)
376 prev_aca->aca_next = aca->aca_next;
377 else
378 idev->ac_list = aca->aca_next;
379 write_unlock_bh(&idev->lock);
380 addrconf_leave_solict(idev, &aca->aca_addr);
381
382 dst_hold(&aca->aca_rt->u.dst);
Jamal Hadi Salim0d51aa82005-06-21 13:51:04 -0700383 if (ip6_del_rt(aca->aca_rt, NULL, NULL, NULL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 dst_free(&aca->aca_rt->u.dst);
385 else
386 dst_release(&aca->aca_rt->u.dst);
387
388 aca_put(aca);
389 return 0;
390}
391
392static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr)
393{
394 int ret;
395 struct inet6_dev *idev = in6_dev_get(dev);
396 if (idev == NULL)
397 return -ENODEV;
398 ret = __ipv6_dev_ac_dec(idev, addr);
399 in6_dev_put(idev);
400 return ret;
401}
402
403/*
404 * check if the interface has this anycast address
405 */
406static int ipv6_chk_acast_dev(struct net_device *dev, struct in6_addr *addr)
407{
408 struct inet6_dev *idev;
409 struct ifacaddr6 *aca;
410
411 idev = in6_dev_get(dev);
412 if (idev) {
413 read_lock_bh(&idev->lock);
414 for (aca = idev->ac_list; aca; aca = aca->aca_next)
415 if (ipv6_addr_equal(&aca->aca_addr, addr))
416 break;
417 read_unlock_bh(&idev->lock);
418 in6_dev_put(idev);
419 return aca != 0;
420 }
421 return 0;
422}
423
424/*
425 * check if given interface (or any, if dev==0) has this anycast address
426 */
427int ipv6_chk_acast_addr(struct net_device *dev, struct in6_addr *addr)
428{
429 if (dev)
430 return ipv6_chk_acast_dev(dev, addr);
431 read_lock(&dev_base_lock);
432 for (dev=dev_base; dev; dev=dev->next)
433 if (ipv6_chk_acast_dev(dev, addr))
434 break;
435 read_unlock(&dev_base_lock);
436 return dev != 0;
437}
438
439
440#ifdef CONFIG_PROC_FS
441struct ac6_iter_state {
442 struct net_device *dev;
443 struct inet6_dev *idev;
444};
445
446#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
447
448static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
449{
450 struct ifacaddr6 *im = NULL;
451 struct ac6_iter_state *state = ac6_seq_private(seq);
452
453 for (state->dev = dev_base, state->idev = NULL;
454 state->dev;
455 state->dev = state->dev->next) {
456 struct inet6_dev *idev;
457 idev = in6_dev_get(state->dev);
458 if (!idev)
459 continue;
460 read_lock_bh(&idev->lock);
461 im = idev->ac_list;
462 if (im) {
463 state->idev = idev;
464 break;
465 }
466 read_unlock_bh(&idev->lock);
467 }
468 return im;
469}
470
471static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
472{
473 struct ac6_iter_state *state = ac6_seq_private(seq);
474
475 im = im->aca_next;
476 while (!im) {
477 if (likely(state->idev != NULL)) {
478 read_unlock_bh(&state->idev->lock);
479 in6_dev_put(state->idev);
480 }
481 state->dev = state->dev->next;
482 if (!state->dev) {
483 state->idev = NULL;
484 break;
485 }
486 state->idev = in6_dev_get(state->dev);
487 if (!state->idev)
488 continue;
489 read_lock_bh(&state->idev->lock);
490 im = state->idev->ac_list;
491 }
492 return im;
493}
494
495static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
496{
497 struct ifacaddr6 *im = ac6_get_first(seq);
498 if (im)
499 while (pos && (im = ac6_get_next(seq, im)) != NULL)
500 --pos;
501 return pos ? NULL : im;
502}
503
504static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
505{
506 read_lock(&dev_base_lock);
507 return ac6_get_idx(seq, *pos);
508}
509
510static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
511{
512 struct ifacaddr6 *im;
513 im = ac6_get_next(seq, v);
514 ++*pos;
515 return im;
516}
517
518static void ac6_seq_stop(struct seq_file *seq, void *v)
519{
520 struct ac6_iter_state *state = ac6_seq_private(seq);
521 if (likely(state->idev != NULL)) {
522 read_unlock_bh(&state->idev->lock);
523 in6_dev_put(state->idev);
524 }
525 read_unlock(&dev_base_lock);
526}
527
528static int ac6_seq_show(struct seq_file *seq, void *v)
529{
530 struct ifacaddr6 *im = (struct ifacaddr6 *)v;
531 struct ac6_iter_state *state = ac6_seq_private(seq);
532
533 seq_printf(seq,
534 "%-4d %-15s "
535 "%04x%04x%04x%04x%04x%04x%04x%04x "
536 "%5d\n",
537 state->dev->ifindex, state->dev->name,
538 NIP6(im->aca_addr),
539 im->aca_users);
540 return 0;
541}
542
543static struct seq_operations ac6_seq_ops = {
544 .start = ac6_seq_start,
545 .next = ac6_seq_next,
546 .stop = ac6_seq_stop,
547 .show = ac6_seq_show,
548};
549
550static int ac6_seq_open(struct inode *inode, struct file *file)
551{
552 struct seq_file *seq;
553 int rc = -ENOMEM;
554 struct ac6_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
555
556 if (!s)
557 goto out;
558
559 rc = seq_open(file, &ac6_seq_ops);
560 if (rc)
561 goto out_kfree;
562
563 seq = file->private_data;
564 seq->private = s;
565 memset(s, 0, sizeof(*s));
566out:
567 return rc;
568out_kfree:
569 kfree(s);
570 goto out;
571}
572
573static struct file_operations ac6_seq_fops = {
574 .owner = THIS_MODULE,
575 .open = ac6_seq_open,
576 .read = seq_read,
577 .llseek = seq_lseek,
578 .release = seq_release_private,
579};
580
581int __init ac6_proc_init(void)
582{
583 if (!proc_net_fops_create("anycast6", S_IRUGO, &ac6_seq_fops))
584 return -ENOMEM;
585
586 return 0;
587}
588
589void ac6_proc_exit(void)
590{
591 proc_net_remove("anycast6");
592}
593#endif
594