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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
16#include <linux/capability.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/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>
32#include <linux/slab.h>
33
34#include <net/net_namespace.h>
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
47static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr);
48
49/* Big ac list lock for all the sockets */
50static DEFINE_RWLOCK(ipv6_sk_ac_lock);
51
52
53/*
54 * socket join an anycast group
55 */
56
57int ipv6_sock_ac_join(struct sock *sk, int ifindex, const 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;
63 struct net *net = sock_net(sk);
64 int ishost = !net->ipv6.devconf_all->forwarding;
65 int err = 0;
66
67 if (!capable(CAP_NET_ADMIN))
68 return -EPERM;
69 if (ipv6_addr_is_multicast(addr))
70 return -EINVAL;
71 if (ipv6_chk_addr(net, addr, NULL, 0))
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 rcu_read_lock();
81 if (ifindex == 0) {
82 struct rt6_info *rt;
83
84 rt = rt6_lookup(net, addr, NULL, 0, 0);
85 if (rt) {
86 dev = rt->rt6i_dev;
87 dst_release(&rt->dst);
88 } else if (ishost) {
89 err = -EADDRNOTAVAIL;
90 goto error;
91 } else {
92 /* router, no matching interface: just pick one */
93 dev = dev_get_by_flags_rcu(net, IFF_UP,
94 IFF_UP | IFF_LOOPBACK);
95 }
96 } else
97 dev = dev_get_by_index_rcu(net, ifindex);
98
99 if (dev == NULL) {
100 err = -ENODEV;
101 goto error;
102 }
103
104 idev = __in6_dev_get(dev);
105 if (!idev) {
106 if (ifindex)
107 err = -ENODEV;
108 else
109 err = -EADDRNOTAVAIL;
110 goto error;
111 }
112 /* reset ishost, now that we have a specific device */
113 ishost = !idev->cnf.forwarding;
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 */
122 if (!ipv6_chk_prefix(addr, dev)) {
123 if (ishost)
124 err = -EADDRNOTAVAIL;
125 if (err)
126 goto error;
127 }
128
129 err = ipv6_dev_ac_inc(dev, addr);
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 }
137
138error:
139 rcu_read_unlock();
140 if (pac)
141 sock_kfree_s(sk, pac, sizeof(*pac));
142 return err;
143}
144
145/*
146 * socket leave an anycast group
147 */
148int ipv6_sock_ac_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
149{
150 struct ipv6_pinfo *np = inet6_sk(sk);
151 struct net_device *dev;
152 struct ipv6_ac_socklist *pac, *prev_pac;
153 struct net *net = sock_net(sk);
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
174 rcu_read_lock();
175 dev = dev_get_by_index_rcu(net, pac->acl_ifindex);
176 if (dev)
177 ipv6_dev_ac_dec(dev, &pac->acl_addr);
178 rcu_read_unlock();
179
180 sock_kfree_s(sk, pac, sizeof(*pac));
181 return 0;
182}
183
184void 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;
189 struct net *net = sock_net(sk);
190 int prev_index;
191
192 write_lock_bh(&ipv6_sk_ac_lock);
193 pac = np->ipv6_ac_list;
194 np->ipv6_ac_list = NULL;
195 write_unlock_bh(&ipv6_sk_ac_lock);
196
197 prev_index = 0;
198 rcu_read_lock();
199 while (pac) {
200 struct ipv6_ac_socklist *next = pac->acl_next;
201
202 if (pac->acl_ifindex != prev_index) {
203 dev = dev_get_by_index_rcu(net, pac->acl_ifindex);
204 prev_index = pac->acl_ifindex;
205 }
206 if (dev)
207 ipv6_dev_ac_dec(dev, &pac->acl_addr);
208 sock_kfree_s(sk, pac, sizeof(*pac));
209 pac = next;
210 }
211 rcu_read_unlock();
212}
213
214#if 0
215/* The function is not used, which is funny. Apparently, author
216 * supposed to use it to filter out datagrams inside udp/raw but forgot.
217 *
218 * It is OK, anycasts are not special comparing to delivery to unicasts.
219 */
220
221int inet6_ac_check(struct sock *sk, struct in6_addr *addr, int ifindex)
222{
223 struct ipv6_ac_socklist *pac;
224 struct ipv6_pinfo *np = inet6_sk(sk);
225 int found;
226
227 found = 0;
228 read_lock(&ipv6_sk_ac_lock);
229 for (pac=np->ipv6_ac_list; pac; pac=pac->acl_next) {
230 if (ifindex && pac->acl_ifindex != ifindex)
231 continue;
232 found = ipv6_addr_equal(&pac->acl_addr, addr);
233 if (found)
234 break;
235 }
236 read_unlock(&ipv6_sk_ac_lock);
237
238 return found;
239}
240
241#endif
242
243static void aca_put(struct ifacaddr6 *ac)
244{
245 if (atomic_dec_and_test(&ac->aca_refcnt)) {
246 in6_dev_put(ac->aca_idev);
247 dst_release(&ac->aca_rt->dst);
248 kfree(ac);
249 }
250}
251
252/*
253 * device anycast group inc (add if not found)
254 */
255int ipv6_dev_ac_inc(struct net_device *dev, const struct in6_addr *addr)
256{
257 struct ifacaddr6 *aca;
258 struct inet6_dev *idev;
259 struct rt6_info *rt;
260 int err;
261
262 idev = in6_dev_get(dev);
263
264 if (idev == NULL)
265 return -EINVAL;
266
267 write_lock_bh(&idev->lock);
268 if (idev->dead) {
269 err = -ENODEV;
270 goto out;
271 }
272
273 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
274 if (ipv6_addr_equal(&aca->aca_addr, addr)) {
275 aca->aca_users++;
276 err = 0;
277 goto out;
278 }
279 }
280
281 /*
282 * not found: create a new one.
283 */
284
285 aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
286
287 if (aca == NULL) {
288 err = -ENOMEM;
289 goto out;
290 }
291
292 rt = addrconf_dst_alloc(idev, addr, 1);
293 if (IS_ERR(rt)) {
294 kfree(aca);
295 err = PTR_ERR(rt);
296 goto out;
297 }
298
299 ipv6_addr_copy(&aca->aca_addr, addr);
300 aca->aca_idev = idev;
301 aca->aca_rt = rt;
302 aca->aca_users = 1;
303 /* aca_tstamp should be updated upon changes */
304 aca->aca_cstamp = aca->aca_tstamp = jiffies;
305 atomic_set(&aca->aca_refcnt, 2);
306 spin_lock_init(&aca->aca_lock);
307
308 aca->aca_next = idev->ac_list;
309 idev->ac_list = aca;
310 write_unlock_bh(&idev->lock);
311
312 ip6_ins_rt(rt);
313
314 addrconf_join_solict(dev, &aca->aca_addr);
315
316 aca_put(aca);
317 return 0;
318out:
319 write_unlock_bh(&idev->lock);
320 in6_dev_put(idev);
321 return err;
322}
323
324/*
325 * device anycast group decrement
326 */
327int __ipv6_dev_ac_dec(struct inet6_dev *idev, const struct in6_addr *addr)
328{
329 struct ifacaddr6 *aca, *prev_aca;
330
331 write_lock_bh(&idev->lock);
332 prev_aca = NULL;
333 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
334 if (ipv6_addr_equal(&aca->aca_addr, addr))
335 break;
336 prev_aca = aca;
337 }
338 if (!aca) {
339 write_unlock_bh(&idev->lock);
340 return -ENOENT;
341 }
342 if (--aca->aca_users > 0) {
343 write_unlock_bh(&idev->lock);
344 return 0;
345 }
346 if (prev_aca)
347 prev_aca->aca_next = aca->aca_next;
348 else
349 idev->ac_list = aca->aca_next;
350 write_unlock_bh(&idev->lock);
351 addrconf_leave_solict(idev, &aca->aca_addr);
352
353 dst_hold(&aca->aca_rt->dst);
354 ip6_del_rt(aca->aca_rt);
355
356 aca_put(aca);
357 return 0;
358}
359
360/* called with rcu_read_lock() */
361static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr)
362{
363 struct inet6_dev *idev = __in6_dev_get(dev);
364
365 if (idev == NULL)
366 return -ENODEV;
367 return __ipv6_dev_ac_dec(idev, addr);
368}
369
370/*
371 * check if the interface has this anycast address
372 * called with rcu_read_lock()
373 */
374static int ipv6_chk_acast_dev(struct net_device *dev, const struct in6_addr *addr)
375{
376 struct inet6_dev *idev;
377 struct ifacaddr6 *aca;
378
379 idev = __in6_dev_get(dev);
380 if (idev) {
381 read_lock_bh(&idev->lock);
382 for (aca = idev->ac_list; aca; aca = aca->aca_next)
383 if (ipv6_addr_equal(&aca->aca_addr, addr))
384 break;
385 read_unlock_bh(&idev->lock);
386 return aca != NULL;
387 }
388 return 0;
389}
390
391/*
392 * check if given interface (or any, if dev==0) has this anycast address
393 */
394int ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
395 const struct in6_addr *addr)
396{
397 int found = 0;
398
399 rcu_read_lock();
400 if (dev)
401 found = ipv6_chk_acast_dev(dev, addr);
402 else
403 for_each_netdev_rcu(net, dev)
404 if (ipv6_chk_acast_dev(dev, addr)) {
405 found = 1;
406 break;
407 }
408 rcu_read_unlock();
409 return found;
410}
411
412
413#ifdef CONFIG_PROC_FS
414struct ac6_iter_state {
415 struct seq_net_private p;
416 struct net_device *dev;
417 struct inet6_dev *idev;
418};
419
420#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
421
422static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
423{
424 struct ifacaddr6 *im = NULL;
425 struct ac6_iter_state *state = ac6_seq_private(seq);
426 struct net *net = seq_file_net(seq);
427
428 state->idev = NULL;
429 for_each_netdev_rcu(net, state->dev) {
430 struct inet6_dev *idev;
431 idev = __in6_dev_get(state->dev);
432 if (!idev)
433 continue;
434 read_lock_bh(&idev->lock);
435 im = idev->ac_list;
436 if (im) {
437 state->idev = idev;
438 break;
439 }
440 read_unlock_bh(&idev->lock);
441 }
442 return im;
443}
444
445static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
446{
447 struct ac6_iter_state *state = ac6_seq_private(seq);
448
449 im = im->aca_next;
450 while (!im) {
451 if (likely(state->idev != NULL))
452 read_unlock_bh(&state->idev->lock);
453
454 state->dev = next_net_device_rcu(state->dev);
455 if (!state->dev) {
456 state->idev = NULL;
457 break;
458 }
459 state->idev = __in6_dev_get(state->dev);
460 if (!state->idev)
461 continue;
462 read_lock_bh(&state->idev->lock);
463 im = state->idev->ac_list;
464 }
465 return im;
466}
467
468static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
469{
470 struct ifacaddr6 *im = ac6_get_first(seq);
471 if (im)
472 while (pos && (im = ac6_get_next(seq, im)) != NULL)
473 --pos;
474 return pos ? NULL : im;
475}
476
477static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
478 __acquires(RCU)
479{
480 rcu_read_lock();
481 return ac6_get_idx(seq, *pos);
482}
483
484static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
485{
486 struct ifacaddr6 *im = ac6_get_next(seq, v);
487
488 ++*pos;
489 return im;
490}
491
492static void ac6_seq_stop(struct seq_file *seq, void *v)
493 __releases(RCU)
494{
495 struct ac6_iter_state *state = ac6_seq_private(seq);
496
497 if (likely(state->idev != NULL)) {
498 read_unlock_bh(&state->idev->lock);
499 state->idev = NULL;
500 }
501 rcu_read_unlock();
502}
503
504static int ac6_seq_show(struct seq_file *seq, void *v)
505{
506 struct ifacaddr6 *im = (struct ifacaddr6 *)v;
507 struct ac6_iter_state *state = ac6_seq_private(seq);
508
509 seq_printf(seq, "%-4d %-15s %pi6 %5d\n",
510 state->dev->ifindex, state->dev->name,
511 &im->aca_addr, im->aca_users);
512 return 0;
513}
514
515static const struct seq_operations ac6_seq_ops = {
516 .start = ac6_seq_start,
517 .next = ac6_seq_next,
518 .stop = ac6_seq_stop,
519 .show = ac6_seq_show,
520};
521
522static int ac6_seq_open(struct inode *inode, struct file *file)
523{
524 return seq_open_net(inode, file, &ac6_seq_ops,
525 sizeof(struct ac6_iter_state));
526}
527
528static const struct file_operations ac6_seq_fops = {
529 .owner = THIS_MODULE,
530 .open = ac6_seq_open,
531 .read = seq_read,
532 .llseek = seq_lseek,
533 .release = seq_release_net,
534};
535
536int __net_init ac6_proc_init(struct net *net)
537{
538 if (!proc_net_fops_create(net, "anycast6", S_IRUGO, &ac6_seq_fops))
539 return -ENOMEM;
540
541 return 0;
542}
543
544void ac6_proc_exit(struct net *net)
545{
546 proc_net_remove(net, "anycast6");
547}
548#endif
549
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
16#include <linux/capability.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/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>
32#include <linux/slab.h>
33
34#include <net/net_namespace.h>
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
47static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr);
48
49/* Big ac list lock for all the sockets */
50static DEFINE_RWLOCK(ipv6_sk_ac_lock);
51
52
53/*
54 * socket join an anycast group
55 */
56
57int ipv6_sock_ac_join(struct sock *sk, int ifindex, const 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;
63 struct net *net = sock_net(sk);
64 int ishost = !net->ipv6.devconf_all->forwarding;
65 int err = 0;
66
67 if (!capable(CAP_NET_ADMIN))
68 return -EPERM;
69 if (ipv6_addr_is_multicast(addr))
70 return -EINVAL;
71 if (ipv6_chk_addr(net, addr, NULL, 0))
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 pac->acl_addr = *addr;
79
80 rcu_read_lock();
81 if (ifindex == 0) {
82 struct rt6_info *rt;
83
84 rt = rt6_lookup(net, addr, NULL, 0, 0);
85 if (rt) {
86 dev = rt->dst.dev;
87 dst_release(&rt->dst);
88 } else if (ishost) {
89 err = -EADDRNOTAVAIL;
90 goto error;
91 } else {
92 /* router, no matching interface: just pick one */
93 dev = dev_get_by_flags_rcu(net, IFF_UP,
94 IFF_UP | IFF_LOOPBACK);
95 }
96 } else
97 dev = dev_get_by_index_rcu(net, ifindex);
98
99 if (dev == NULL) {
100 err = -ENODEV;
101 goto error;
102 }
103
104 idev = __in6_dev_get(dev);
105 if (!idev) {
106 if (ifindex)
107 err = -ENODEV;
108 else
109 err = -EADDRNOTAVAIL;
110 goto error;
111 }
112 /* reset ishost, now that we have a specific device */
113 ishost = !idev->cnf.forwarding;
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 */
122 if (!ipv6_chk_prefix(addr, dev)) {
123 if (ishost)
124 err = -EADDRNOTAVAIL;
125 if (err)
126 goto error;
127 }
128
129 err = ipv6_dev_ac_inc(dev, addr);
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 }
137
138error:
139 rcu_read_unlock();
140 if (pac)
141 sock_kfree_s(sk, pac, sizeof(*pac));
142 return err;
143}
144
145/*
146 * socket leave an anycast group
147 */
148int ipv6_sock_ac_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
149{
150 struct ipv6_pinfo *np = inet6_sk(sk);
151 struct net_device *dev;
152 struct ipv6_ac_socklist *pac, *prev_pac;
153 struct net *net = sock_net(sk);
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
174 rcu_read_lock();
175 dev = dev_get_by_index_rcu(net, pac->acl_ifindex);
176 if (dev)
177 ipv6_dev_ac_dec(dev, &pac->acl_addr);
178 rcu_read_unlock();
179
180 sock_kfree_s(sk, pac, sizeof(*pac));
181 return 0;
182}
183
184void 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;
189 struct net *net = sock_net(sk);
190 int prev_index;
191
192 write_lock_bh(&ipv6_sk_ac_lock);
193 pac = np->ipv6_ac_list;
194 np->ipv6_ac_list = NULL;
195 write_unlock_bh(&ipv6_sk_ac_lock);
196
197 prev_index = 0;
198 rcu_read_lock();
199 while (pac) {
200 struct ipv6_ac_socklist *next = pac->acl_next;
201
202 if (pac->acl_ifindex != prev_index) {
203 dev = dev_get_by_index_rcu(net, pac->acl_ifindex);
204 prev_index = pac->acl_ifindex;
205 }
206 if (dev)
207 ipv6_dev_ac_dec(dev, &pac->acl_addr);
208 sock_kfree_s(sk, pac, sizeof(*pac));
209 pac = next;
210 }
211 rcu_read_unlock();
212}
213
214static void aca_put(struct ifacaddr6 *ac)
215{
216 if (atomic_dec_and_test(&ac->aca_refcnt)) {
217 in6_dev_put(ac->aca_idev);
218 dst_release(&ac->aca_rt->dst);
219 kfree(ac);
220 }
221}
222
223/*
224 * device anycast group inc (add if not found)
225 */
226int ipv6_dev_ac_inc(struct net_device *dev, const struct in6_addr *addr)
227{
228 struct ifacaddr6 *aca;
229 struct inet6_dev *idev;
230 struct rt6_info *rt;
231 int err;
232
233 idev = in6_dev_get(dev);
234
235 if (idev == NULL)
236 return -EINVAL;
237
238 write_lock_bh(&idev->lock);
239 if (idev->dead) {
240 err = -ENODEV;
241 goto out;
242 }
243
244 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
245 if (ipv6_addr_equal(&aca->aca_addr, addr)) {
246 aca->aca_users++;
247 err = 0;
248 goto out;
249 }
250 }
251
252 /*
253 * not found: create a new one.
254 */
255
256 aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
257
258 if (aca == NULL) {
259 err = -ENOMEM;
260 goto out;
261 }
262
263 rt = addrconf_dst_alloc(idev, addr, true);
264 if (IS_ERR(rt)) {
265 kfree(aca);
266 err = PTR_ERR(rt);
267 goto out;
268 }
269
270 aca->aca_addr = *addr;
271 aca->aca_idev = idev;
272 aca->aca_rt = rt;
273 aca->aca_users = 1;
274 /* aca_tstamp should be updated upon changes */
275 aca->aca_cstamp = aca->aca_tstamp = jiffies;
276 atomic_set(&aca->aca_refcnt, 2);
277 spin_lock_init(&aca->aca_lock);
278
279 aca->aca_next = idev->ac_list;
280 idev->ac_list = aca;
281 write_unlock_bh(&idev->lock);
282
283 ip6_ins_rt(rt);
284
285 addrconf_join_solict(dev, &aca->aca_addr);
286
287 aca_put(aca);
288 return 0;
289out:
290 write_unlock_bh(&idev->lock);
291 in6_dev_put(idev);
292 return err;
293}
294
295/*
296 * device anycast group decrement
297 */
298int __ipv6_dev_ac_dec(struct inet6_dev *idev, const struct in6_addr *addr)
299{
300 struct ifacaddr6 *aca, *prev_aca;
301
302 write_lock_bh(&idev->lock);
303 prev_aca = NULL;
304 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
305 if (ipv6_addr_equal(&aca->aca_addr, addr))
306 break;
307 prev_aca = aca;
308 }
309 if (!aca) {
310 write_unlock_bh(&idev->lock);
311 return -ENOENT;
312 }
313 if (--aca->aca_users > 0) {
314 write_unlock_bh(&idev->lock);
315 return 0;
316 }
317 if (prev_aca)
318 prev_aca->aca_next = aca->aca_next;
319 else
320 idev->ac_list = aca->aca_next;
321 write_unlock_bh(&idev->lock);
322 addrconf_leave_solict(idev, &aca->aca_addr);
323
324 dst_hold(&aca->aca_rt->dst);
325 ip6_del_rt(aca->aca_rt);
326
327 aca_put(aca);
328 return 0;
329}
330
331/* called with rcu_read_lock() */
332static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr)
333{
334 struct inet6_dev *idev = __in6_dev_get(dev);
335
336 if (idev == NULL)
337 return -ENODEV;
338 return __ipv6_dev_ac_dec(idev, addr);
339}
340
341/*
342 * check if the interface has this anycast address
343 * called with rcu_read_lock()
344 */
345static bool ipv6_chk_acast_dev(struct net_device *dev, const struct in6_addr *addr)
346{
347 struct inet6_dev *idev;
348 struct ifacaddr6 *aca;
349
350 idev = __in6_dev_get(dev);
351 if (idev) {
352 read_lock_bh(&idev->lock);
353 for (aca = idev->ac_list; aca; aca = aca->aca_next)
354 if (ipv6_addr_equal(&aca->aca_addr, addr))
355 break;
356 read_unlock_bh(&idev->lock);
357 return aca != NULL;
358 }
359 return false;
360}
361
362/*
363 * check if given interface (or any, if dev==0) has this anycast address
364 */
365bool ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
366 const struct in6_addr *addr)
367{
368 bool found = false;
369
370 rcu_read_lock();
371 if (dev)
372 found = ipv6_chk_acast_dev(dev, addr);
373 else
374 for_each_netdev_rcu(net, dev)
375 if (ipv6_chk_acast_dev(dev, addr)) {
376 found = true;
377 break;
378 }
379 rcu_read_unlock();
380 return found;
381}
382
383
384#ifdef CONFIG_PROC_FS
385struct ac6_iter_state {
386 struct seq_net_private p;
387 struct net_device *dev;
388 struct inet6_dev *idev;
389};
390
391#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
392
393static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
394{
395 struct ifacaddr6 *im = NULL;
396 struct ac6_iter_state *state = ac6_seq_private(seq);
397 struct net *net = seq_file_net(seq);
398
399 state->idev = NULL;
400 for_each_netdev_rcu(net, state->dev) {
401 struct inet6_dev *idev;
402 idev = __in6_dev_get(state->dev);
403 if (!idev)
404 continue;
405 read_lock_bh(&idev->lock);
406 im = idev->ac_list;
407 if (im) {
408 state->idev = idev;
409 break;
410 }
411 read_unlock_bh(&idev->lock);
412 }
413 return im;
414}
415
416static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
417{
418 struct ac6_iter_state *state = ac6_seq_private(seq);
419
420 im = im->aca_next;
421 while (!im) {
422 if (likely(state->idev != NULL))
423 read_unlock_bh(&state->idev->lock);
424
425 state->dev = next_net_device_rcu(state->dev);
426 if (!state->dev) {
427 state->idev = NULL;
428 break;
429 }
430 state->idev = __in6_dev_get(state->dev);
431 if (!state->idev)
432 continue;
433 read_lock_bh(&state->idev->lock);
434 im = state->idev->ac_list;
435 }
436 return im;
437}
438
439static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
440{
441 struct ifacaddr6 *im = ac6_get_first(seq);
442 if (im)
443 while (pos && (im = ac6_get_next(seq, im)) != NULL)
444 --pos;
445 return pos ? NULL : im;
446}
447
448static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
449 __acquires(RCU)
450{
451 rcu_read_lock();
452 return ac6_get_idx(seq, *pos);
453}
454
455static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
456{
457 struct ifacaddr6 *im = ac6_get_next(seq, v);
458
459 ++*pos;
460 return im;
461}
462
463static void ac6_seq_stop(struct seq_file *seq, void *v)
464 __releases(RCU)
465{
466 struct ac6_iter_state *state = ac6_seq_private(seq);
467
468 if (likely(state->idev != NULL)) {
469 read_unlock_bh(&state->idev->lock);
470 state->idev = NULL;
471 }
472 rcu_read_unlock();
473}
474
475static int ac6_seq_show(struct seq_file *seq, void *v)
476{
477 struct ifacaddr6 *im = (struct ifacaddr6 *)v;
478 struct ac6_iter_state *state = ac6_seq_private(seq);
479
480 seq_printf(seq, "%-4d %-15s %pi6 %5d\n",
481 state->dev->ifindex, state->dev->name,
482 &im->aca_addr, im->aca_users);
483 return 0;
484}
485
486static const struct seq_operations ac6_seq_ops = {
487 .start = ac6_seq_start,
488 .next = ac6_seq_next,
489 .stop = ac6_seq_stop,
490 .show = ac6_seq_show,
491};
492
493static int ac6_seq_open(struct inode *inode, struct file *file)
494{
495 return seq_open_net(inode, file, &ac6_seq_ops,
496 sizeof(struct ac6_iter_state));
497}
498
499static const struct file_operations ac6_seq_fops = {
500 .owner = THIS_MODULE,
501 .open = ac6_seq_open,
502 .read = seq_read,
503 .llseek = seq_lseek,
504 .release = seq_release_net,
505};
506
507int __net_init ac6_proc_init(struct net *net)
508{
509 if (!proc_net_fops_create(net, "anycast6", S_IRUGO, &ac6_seq_fops))
510 return -ENOMEM;
511
512 return 0;
513}
514
515void ac6_proc_exit(struct net *net)
516{
517 proc_net_remove(net, "anycast6");
518}
519#endif
520