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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/*
50 * socket join an anycast group
51 */
52
53int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
54{
55 struct ipv6_pinfo *np = inet6_sk(sk);
56 struct net_device *dev = NULL;
57 struct inet6_dev *idev;
58 struct ipv6_ac_socklist *pac;
59 struct net *net = sock_net(sk);
60 int ishost = !net->ipv6.devconf_all->forwarding;
61 int err = 0;
62
63 ASSERT_RTNL();
64
65 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
66 return -EPERM;
67 if (ipv6_addr_is_multicast(addr))
68 return -EINVAL;
69 if (ipv6_chk_addr(net, addr, NULL, 0))
70 return -EINVAL;
71
72 pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
73 if (!pac)
74 return -ENOMEM;
75 pac->acl_next = NULL;
76 pac->acl_addr = *addr;
77
78 if (ifindex == 0) {
79 struct rt6_info *rt;
80
81 rt = rt6_lookup(net, addr, NULL, 0, 0);
82 if (rt) {
83 dev = rt->dst.dev;
84 ip6_rt_put(rt);
85 } else if (ishost) {
86 err = -EADDRNOTAVAIL;
87 goto error;
88 } else {
89 /* router, no matching interface: just pick one */
90 dev = __dev_get_by_flags(net, IFF_UP,
91 IFF_UP | IFF_LOOPBACK);
92 }
93 } else
94 dev = __dev_get_by_index(net, ifindex);
95
96 if (!dev) {
97 err = -ENODEV;
98 goto error;
99 }
100
101 idev = __in6_dev_get(dev);
102 if (!idev) {
103 if (ifindex)
104 err = -ENODEV;
105 else
106 err = -EADDRNOTAVAIL;
107 goto error;
108 }
109 /* reset ishost, now that we have a specific device */
110 ishost = !idev->cnf.forwarding;
111
112 pac->acl_ifindex = dev->ifindex;
113
114 /* XXX
115 * For hosts, allow link-local or matching prefix anycasts.
116 * This obviates the need for propagating anycast routes while
117 * still allowing some non-router anycast participation.
118 */
119 if (!ipv6_chk_prefix(addr, dev)) {
120 if (ishost)
121 err = -EADDRNOTAVAIL;
122 if (err)
123 goto error;
124 }
125
126 err = __ipv6_dev_ac_inc(idev, addr);
127 if (!err) {
128 pac->acl_next = np->ipv6_ac_list;
129 np->ipv6_ac_list = pac;
130 pac = NULL;
131 }
132
133error:
134 if (pac)
135 sock_kfree_s(sk, pac, sizeof(*pac));
136 return err;
137}
138
139/*
140 * socket leave an anycast group
141 */
142int ipv6_sock_ac_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
143{
144 struct ipv6_pinfo *np = inet6_sk(sk);
145 struct net_device *dev;
146 struct ipv6_ac_socklist *pac, *prev_pac;
147 struct net *net = sock_net(sk);
148
149 ASSERT_RTNL();
150
151 prev_pac = NULL;
152 for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
153 if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
154 ipv6_addr_equal(&pac->acl_addr, addr))
155 break;
156 prev_pac = pac;
157 }
158 if (!pac)
159 return -ENOENT;
160 if (prev_pac)
161 prev_pac->acl_next = pac->acl_next;
162 else
163 np->ipv6_ac_list = pac->acl_next;
164
165 dev = __dev_get_by_index(net, pac->acl_ifindex);
166 if (dev)
167 ipv6_dev_ac_dec(dev, &pac->acl_addr);
168
169 sock_kfree_s(sk, pac, sizeof(*pac));
170 return 0;
171}
172
173void ipv6_sock_ac_close(struct sock *sk)
174{
175 struct ipv6_pinfo *np = inet6_sk(sk);
176 struct net_device *dev = NULL;
177 struct ipv6_ac_socklist *pac;
178 struct net *net = sock_net(sk);
179 int prev_index;
180
181 if (!np->ipv6_ac_list)
182 return;
183
184 rtnl_lock();
185 pac = np->ipv6_ac_list;
186 np->ipv6_ac_list = NULL;
187
188 prev_index = 0;
189 while (pac) {
190 struct ipv6_ac_socklist *next = pac->acl_next;
191
192 if (pac->acl_ifindex != prev_index) {
193 dev = __dev_get_by_index(net, pac->acl_ifindex);
194 prev_index = pac->acl_ifindex;
195 }
196 if (dev)
197 ipv6_dev_ac_dec(dev, &pac->acl_addr);
198 sock_kfree_s(sk, pac, sizeof(*pac));
199 pac = next;
200 }
201 rtnl_unlock();
202}
203
204static void aca_get(struct ifacaddr6 *aca)
205{
206 atomic_inc(&aca->aca_refcnt);
207}
208
209static void aca_put(struct ifacaddr6 *ac)
210{
211 if (atomic_dec_and_test(&ac->aca_refcnt)) {
212 in6_dev_put(ac->aca_idev);
213 dst_release(&ac->aca_rt->dst);
214 kfree(ac);
215 }
216}
217
218static struct ifacaddr6 *aca_alloc(struct rt6_info *rt,
219 const struct in6_addr *addr)
220{
221 struct inet6_dev *idev = rt->rt6i_idev;
222 struct ifacaddr6 *aca;
223
224 aca = kzalloc(sizeof(*aca), GFP_ATOMIC);
225 if (!aca)
226 return NULL;
227
228 aca->aca_addr = *addr;
229 in6_dev_hold(idev);
230 aca->aca_idev = idev;
231 aca->aca_rt = rt;
232 aca->aca_users = 1;
233 /* aca_tstamp should be updated upon changes */
234 aca->aca_cstamp = aca->aca_tstamp = jiffies;
235 atomic_set(&aca->aca_refcnt, 1);
236
237 return aca;
238}
239
240/*
241 * device anycast group inc (add if not found)
242 */
243int __ipv6_dev_ac_inc(struct inet6_dev *idev, const struct in6_addr *addr)
244{
245 struct ifacaddr6 *aca;
246 struct rt6_info *rt;
247 int err;
248
249 ASSERT_RTNL();
250
251 write_lock_bh(&idev->lock);
252 if (idev->dead) {
253 err = -ENODEV;
254 goto out;
255 }
256
257 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
258 if (ipv6_addr_equal(&aca->aca_addr, addr)) {
259 aca->aca_users++;
260 err = 0;
261 goto out;
262 }
263 }
264
265 rt = addrconf_dst_alloc(idev, addr, true);
266 if (IS_ERR(rt)) {
267 err = PTR_ERR(rt);
268 goto out;
269 }
270 aca = aca_alloc(rt, addr);
271 if (!aca) {
272 ip6_rt_put(rt);
273 err = -ENOMEM;
274 goto out;
275 }
276
277 aca->aca_next = idev->ac_list;
278 idev->ac_list = aca;
279
280 /* Hold this for addrconf_join_solict() below before we unlock,
281 * it is already exposed via idev->ac_list.
282 */
283 aca_get(aca);
284 write_unlock_bh(&idev->lock);
285
286 ip6_ins_rt(rt);
287
288 addrconf_join_solict(idev->dev, &aca->aca_addr);
289
290 aca_put(aca);
291 return 0;
292out:
293 write_unlock_bh(&idev->lock);
294 return err;
295}
296
297/*
298 * device anycast group decrement
299 */
300int __ipv6_dev_ac_dec(struct inet6_dev *idev, const struct in6_addr *addr)
301{
302 struct ifacaddr6 *aca, *prev_aca;
303
304 ASSERT_RTNL();
305
306 write_lock_bh(&idev->lock);
307 prev_aca = NULL;
308 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
309 if (ipv6_addr_equal(&aca->aca_addr, addr))
310 break;
311 prev_aca = aca;
312 }
313 if (!aca) {
314 write_unlock_bh(&idev->lock);
315 return -ENOENT;
316 }
317 if (--aca->aca_users > 0) {
318 write_unlock_bh(&idev->lock);
319 return 0;
320 }
321 if (prev_aca)
322 prev_aca->aca_next = aca->aca_next;
323 else
324 idev->ac_list = aca->aca_next;
325 write_unlock_bh(&idev->lock);
326 addrconf_leave_solict(idev, &aca->aca_addr);
327
328 dst_hold(&aca->aca_rt->dst);
329 ip6_del_rt(aca->aca_rt);
330
331 aca_put(aca);
332 return 0;
333}
334
335/* called with rtnl_lock() */
336static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr)
337{
338 struct inet6_dev *idev = __in6_dev_get(dev);
339
340 if (!idev)
341 return -ENODEV;
342 return __ipv6_dev_ac_dec(idev, addr);
343}
344
345void ipv6_ac_destroy_dev(struct inet6_dev *idev)
346{
347 struct ifacaddr6 *aca;
348
349 write_lock_bh(&idev->lock);
350 while ((aca = idev->ac_list) != NULL) {
351 idev->ac_list = aca->aca_next;
352 write_unlock_bh(&idev->lock);
353
354 addrconf_leave_solict(idev, &aca->aca_addr);
355
356 dst_hold(&aca->aca_rt->dst);
357 ip6_del_rt(aca->aca_rt);
358
359 aca_put(aca);
360
361 write_lock_bh(&idev->lock);
362 }
363 write_unlock_bh(&idev->lock);
364}
365
366/*
367 * check if the interface has this anycast address
368 * called with rcu_read_lock()
369 */
370static bool ipv6_chk_acast_dev(struct net_device *dev, const struct in6_addr *addr)
371{
372 struct inet6_dev *idev;
373 struct ifacaddr6 *aca;
374
375 idev = __in6_dev_get(dev);
376 if (idev) {
377 read_lock_bh(&idev->lock);
378 for (aca = idev->ac_list; aca; aca = aca->aca_next)
379 if (ipv6_addr_equal(&aca->aca_addr, addr))
380 break;
381 read_unlock_bh(&idev->lock);
382 return aca != NULL;
383 }
384 return false;
385}
386
387/*
388 * check if given interface (or any, if dev==0) has this anycast address
389 */
390bool ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
391 const struct in6_addr *addr)
392{
393 bool found = false;
394
395 rcu_read_lock();
396 if (dev)
397 found = ipv6_chk_acast_dev(dev, addr);
398 else
399 for_each_netdev_rcu(net, dev)
400 if (ipv6_chk_acast_dev(dev, addr)) {
401 found = true;
402 break;
403 }
404 rcu_read_unlock();
405 return found;
406}
407
408/* check if this anycast address is link-local on given interface or
409 * is global
410 */
411bool ipv6_chk_acast_addr_src(struct net *net, struct net_device *dev,
412 const struct in6_addr *addr)
413{
414 return ipv6_chk_acast_addr(net,
415 (ipv6_addr_type(addr) & IPV6_ADDR_LINKLOCAL ?
416 dev : NULL),
417 addr);
418}
419
420#ifdef CONFIG_PROC_FS
421struct ac6_iter_state {
422 struct seq_net_private p;
423 struct net_device *dev;
424 struct inet6_dev *idev;
425};
426
427#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
428
429static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
430{
431 struct ifacaddr6 *im = NULL;
432 struct ac6_iter_state *state = ac6_seq_private(seq);
433 struct net *net = seq_file_net(seq);
434
435 state->idev = NULL;
436 for_each_netdev_rcu(net, state->dev) {
437 struct inet6_dev *idev;
438 idev = __in6_dev_get(state->dev);
439 if (!idev)
440 continue;
441 read_lock_bh(&idev->lock);
442 im = idev->ac_list;
443 if (im) {
444 state->idev = idev;
445 break;
446 }
447 read_unlock_bh(&idev->lock);
448 }
449 return im;
450}
451
452static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
453{
454 struct ac6_iter_state *state = ac6_seq_private(seq);
455
456 im = im->aca_next;
457 while (!im) {
458 if (likely(state->idev != NULL))
459 read_unlock_bh(&state->idev->lock);
460
461 state->dev = next_net_device_rcu(state->dev);
462 if (!state->dev) {
463 state->idev = NULL;
464 break;
465 }
466 state->idev = __in6_dev_get(state->dev);
467 if (!state->idev)
468 continue;
469 read_lock_bh(&state->idev->lock);
470 im = state->idev->ac_list;
471 }
472 return im;
473}
474
475static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
476{
477 struct ifacaddr6 *im = ac6_get_first(seq);
478 if (im)
479 while (pos && (im = ac6_get_next(seq, im)) != NULL)
480 --pos;
481 return pos ? NULL : im;
482}
483
484static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
485 __acquires(RCU)
486{
487 rcu_read_lock();
488 return ac6_get_idx(seq, *pos);
489}
490
491static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
492{
493 struct ifacaddr6 *im = ac6_get_next(seq, v);
494
495 ++*pos;
496 return im;
497}
498
499static void ac6_seq_stop(struct seq_file *seq, void *v)
500 __releases(RCU)
501{
502 struct ac6_iter_state *state = ac6_seq_private(seq);
503
504 if (likely(state->idev != NULL)) {
505 read_unlock_bh(&state->idev->lock);
506 state->idev = NULL;
507 }
508 rcu_read_unlock();
509}
510
511static int ac6_seq_show(struct seq_file *seq, void *v)
512{
513 struct ifacaddr6 *im = (struct ifacaddr6 *)v;
514 struct ac6_iter_state *state = ac6_seq_private(seq);
515
516 seq_printf(seq, "%-4d %-15s %pi6 %5d\n",
517 state->dev->ifindex, state->dev->name,
518 &im->aca_addr, im->aca_users);
519 return 0;
520}
521
522static const struct seq_operations ac6_seq_ops = {
523 .start = ac6_seq_start,
524 .next = ac6_seq_next,
525 .stop = ac6_seq_stop,
526 .show = ac6_seq_show,
527};
528
529static int ac6_seq_open(struct inode *inode, struct file *file)
530{
531 return seq_open_net(inode, file, &ac6_seq_ops,
532 sizeof(struct ac6_iter_state));
533}
534
535static const struct file_operations ac6_seq_fops = {
536 .owner = THIS_MODULE,
537 .open = ac6_seq_open,
538 .read = seq_read,
539 .llseek = seq_lseek,
540 .release = seq_release_net,
541};
542
543int __net_init ac6_proc_init(struct net *net)
544{
545 if (!proc_create("anycast6", S_IRUGO, net->proc_net, &ac6_seq_fops))
546 return -ENOMEM;
547
548 return 0;
549}
550
551void ac6_proc_exit(struct net *net)
552{
553 remove_proc_entry("anycast6", net->proc_net);
554}
555#endif
556
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/*
50 * socket join an anycast group
51 */
52
53int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
54{
55 struct ipv6_pinfo *np = inet6_sk(sk);
56 struct net_device *dev = NULL;
57 struct inet6_dev *idev;
58 struct ipv6_ac_socklist *pac;
59 struct net *net = sock_net(sk);
60 int ishost = !net->ipv6.devconf_all->forwarding;
61 int err = 0;
62
63 ASSERT_RTNL();
64
65 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
66 return -EPERM;
67 if (ipv6_addr_is_multicast(addr))
68 return -EINVAL;
69 if (ipv6_chk_addr(net, addr, NULL, 0))
70 return -EINVAL;
71
72 pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
73 if (!pac)
74 return -ENOMEM;
75 pac->acl_next = NULL;
76 pac->acl_addr = *addr;
77
78 if (ifindex == 0) {
79 struct rt6_info *rt;
80
81 rt = rt6_lookup(net, addr, NULL, 0, 0);
82 if (rt) {
83 dev = rt->dst.dev;
84 ip6_rt_put(rt);
85 } else if (ishost) {
86 err = -EADDRNOTAVAIL;
87 goto error;
88 } else {
89 /* router, no matching interface: just pick one */
90 dev = __dev_get_by_flags(net, IFF_UP,
91 IFF_UP | IFF_LOOPBACK);
92 }
93 } else
94 dev = __dev_get_by_index(net, ifindex);
95
96 if (!dev) {
97 err = -ENODEV;
98 goto error;
99 }
100
101 idev = __in6_dev_get(dev);
102 if (!idev) {
103 if (ifindex)
104 err = -ENODEV;
105 else
106 err = -EADDRNOTAVAIL;
107 goto error;
108 }
109 /* reset ishost, now that we have a specific device */
110 ishost = !idev->cnf.forwarding;
111
112 pac->acl_ifindex = dev->ifindex;
113
114 /* XXX
115 * For hosts, allow link-local or matching prefix anycasts.
116 * This obviates the need for propagating anycast routes while
117 * still allowing some non-router anycast participation.
118 */
119 if (!ipv6_chk_prefix(addr, dev)) {
120 if (ishost)
121 err = -EADDRNOTAVAIL;
122 if (err)
123 goto error;
124 }
125
126 err = __ipv6_dev_ac_inc(idev, addr);
127 if (!err) {
128 pac->acl_next = np->ipv6_ac_list;
129 np->ipv6_ac_list = pac;
130 pac = NULL;
131 }
132
133error:
134 if (pac)
135 sock_kfree_s(sk, pac, sizeof(*pac));
136 return err;
137}
138
139/*
140 * socket leave an anycast group
141 */
142int ipv6_sock_ac_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
143{
144 struct ipv6_pinfo *np = inet6_sk(sk);
145 struct net_device *dev;
146 struct ipv6_ac_socklist *pac, *prev_pac;
147 struct net *net = sock_net(sk);
148
149 ASSERT_RTNL();
150
151 prev_pac = NULL;
152 for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
153 if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
154 ipv6_addr_equal(&pac->acl_addr, addr))
155 break;
156 prev_pac = pac;
157 }
158 if (!pac)
159 return -ENOENT;
160 if (prev_pac)
161 prev_pac->acl_next = pac->acl_next;
162 else
163 np->ipv6_ac_list = pac->acl_next;
164
165 dev = __dev_get_by_index(net, pac->acl_ifindex);
166 if (dev)
167 ipv6_dev_ac_dec(dev, &pac->acl_addr);
168
169 sock_kfree_s(sk, pac, sizeof(*pac));
170 return 0;
171}
172
173void ipv6_sock_ac_close(struct sock *sk)
174{
175 struct ipv6_pinfo *np = inet6_sk(sk);
176 struct net_device *dev = NULL;
177 struct ipv6_ac_socklist *pac;
178 struct net *net = sock_net(sk);
179 int prev_index;
180
181 if (!np->ipv6_ac_list)
182 return;
183
184 rtnl_lock();
185 pac = np->ipv6_ac_list;
186 np->ipv6_ac_list = NULL;
187
188 prev_index = 0;
189 while (pac) {
190 struct ipv6_ac_socklist *next = pac->acl_next;
191
192 if (pac->acl_ifindex != prev_index) {
193 dev = __dev_get_by_index(net, pac->acl_ifindex);
194 prev_index = pac->acl_ifindex;
195 }
196 if (dev)
197 ipv6_dev_ac_dec(dev, &pac->acl_addr);
198 sock_kfree_s(sk, pac, sizeof(*pac));
199 pac = next;
200 }
201 rtnl_unlock();
202}
203
204static void aca_get(struct ifacaddr6 *aca)
205{
206 atomic_inc(&aca->aca_refcnt);
207}
208
209static void aca_put(struct ifacaddr6 *ac)
210{
211 if (atomic_dec_and_test(&ac->aca_refcnt)) {
212 in6_dev_put(ac->aca_idev);
213 dst_release(&ac->aca_rt->dst);
214 kfree(ac);
215 }
216}
217
218static struct ifacaddr6 *aca_alloc(struct rt6_info *rt,
219 const struct in6_addr *addr)
220{
221 struct inet6_dev *idev = rt->rt6i_idev;
222 struct ifacaddr6 *aca;
223
224 aca = kzalloc(sizeof(*aca), GFP_ATOMIC);
225 if (!aca)
226 return NULL;
227
228 aca->aca_addr = *addr;
229 in6_dev_hold(idev);
230 aca->aca_idev = idev;
231 aca->aca_rt = rt;
232 aca->aca_users = 1;
233 /* aca_tstamp should be updated upon changes */
234 aca->aca_cstamp = aca->aca_tstamp = jiffies;
235 atomic_set(&aca->aca_refcnt, 1);
236
237 return aca;
238}
239
240/*
241 * device anycast group inc (add if not found)
242 */
243int __ipv6_dev_ac_inc(struct inet6_dev *idev, const struct in6_addr *addr)
244{
245 struct ifacaddr6 *aca;
246 struct rt6_info *rt;
247 int err;
248
249 ASSERT_RTNL();
250
251 write_lock_bh(&idev->lock);
252 if (idev->dead) {
253 err = -ENODEV;
254 goto out;
255 }
256
257 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
258 if (ipv6_addr_equal(&aca->aca_addr, addr)) {
259 aca->aca_users++;
260 err = 0;
261 goto out;
262 }
263 }
264
265 rt = addrconf_dst_alloc(idev, addr, true);
266 if (IS_ERR(rt)) {
267 err = PTR_ERR(rt);
268 goto out;
269 }
270 aca = aca_alloc(rt, addr);
271 if (!aca) {
272 ip6_rt_put(rt);
273 err = -ENOMEM;
274 goto out;
275 }
276
277 aca->aca_next = idev->ac_list;
278 idev->ac_list = aca;
279
280 /* Hold this for addrconf_join_solict() below before we unlock,
281 * it is already exposed via idev->ac_list.
282 */
283 aca_get(aca);
284 write_unlock_bh(&idev->lock);
285
286 ip6_ins_rt(rt);
287
288 addrconf_join_solict(idev->dev, &aca->aca_addr);
289
290 aca_put(aca);
291 return 0;
292out:
293 write_unlock_bh(&idev->lock);
294 return err;
295}
296
297/*
298 * device anycast group decrement
299 */
300int __ipv6_dev_ac_dec(struct inet6_dev *idev, const struct in6_addr *addr)
301{
302 struct ifacaddr6 *aca, *prev_aca;
303
304 ASSERT_RTNL();
305
306 write_lock_bh(&idev->lock);
307 prev_aca = NULL;
308 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
309 if (ipv6_addr_equal(&aca->aca_addr, addr))
310 break;
311 prev_aca = aca;
312 }
313 if (!aca) {
314 write_unlock_bh(&idev->lock);
315 return -ENOENT;
316 }
317 if (--aca->aca_users > 0) {
318 write_unlock_bh(&idev->lock);
319 return 0;
320 }
321 if (prev_aca)
322 prev_aca->aca_next = aca->aca_next;
323 else
324 idev->ac_list = aca->aca_next;
325 write_unlock_bh(&idev->lock);
326 addrconf_leave_solict(idev, &aca->aca_addr);
327
328 dst_hold(&aca->aca_rt->dst);
329 ip6_del_rt(aca->aca_rt);
330
331 aca_put(aca);
332 return 0;
333}
334
335/* called with rtnl_lock() */
336static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr)
337{
338 struct inet6_dev *idev = __in6_dev_get(dev);
339
340 if (!idev)
341 return -ENODEV;
342 return __ipv6_dev_ac_dec(idev, addr);
343}
344
345void ipv6_ac_destroy_dev(struct inet6_dev *idev)
346{
347 struct ifacaddr6 *aca;
348
349 write_lock_bh(&idev->lock);
350 while ((aca = idev->ac_list) != NULL) {
351 idev->ac_list = aca->aca_next;
352 write_unlock_bh(&idev->lock);
353
354 addrconf_leave_solict(idev, &aca->aca_addr);
355
356 dst_hold(&aca->aca_rt->dst);
357 ip6_del_rt(aca->aca_rt);
358
359 aca_put(aca);
360
361 write_lock_bh(&idev->lock);
362 }
363 write_unlock_bh(&idev->lock);
364}
365
366/*
367 * check if the interface has this anycast address
368 * called with rcu_read_lock()
369 */
370static bool ipv6_chk_acast_dev(struct net_device *dev, const struct in6_addr *addr)
371{
372 struct inet6_dev *idev;
373 struct ifacaddr6 *aca;
374
375 idev = __in6_dev_get(dev);
376 if (idev) {
377 read_lock_bh(&idev->lock);
378 for (aca = idev->ac_list; aca; aca = aca->aca_next)
379 if (ipv6_addr_equal(&aca->aca_addr, addr))
380 break;
381 read_unlock_bh(&idev->lock);
382 return aca != NULL;
383 }
384 return false;
385}
386
387/*
388 * check if given interface (or any, if dev==0) has this anycast address
389 */
390bool ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
391 const struct in6_addr *addr)
392{
393 bool found = false;
394
395 rcu_read_lock();
396 if (dev)
397 found = ipv6_chk_acast_dev(dev, addr);
398 else
399 for_each_netdev_rcu(net, dev)
400 if (ipv6_chk_acast_dev(dev, addr)) {
401 found = true;
402 break;
403 }
404 rcu_read_unlock();
405 return found;
406}
407
408/* check if this anycast address is link-local on given interface or
409 * is global
410 */
411bool ipv6_chk_acast_addr_src(struct net *net, struct net_device *dev,
412 const struct in6_addr *addr)
413{
414 return ipv6_chk_acast_addr(net,
415 (ipv6_addr_type(addr) & IPV6_ADDR_LINKLOCAL ?
416 dev : NULL),
417 addr);
418}
419
420#ifdef CONFIG_PROC_FS
421struct ac6_iter_state {
422 struct seq_net_private p;
423 struct net_device *dev;
424 struct inet6_dev *idev;
425};
426
427#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
428
429static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
430{
431 struct ifacaddr6 *im = NULL;
432 struct ac6_iter_state *state = ac6_seq_private(seq);
433 struct net *net = seq_file_net(seq);
434
435 state->idev = NULL;
436 for_each_netdev_rcu(net, state->dev) {
437 struct inet6_dev *idev;
438 idev = __in6_dev_get(state->dev);
439 if (!idev)
440 continue;
441 read_lock_bh(&idev->lock);
442 im = idev->ac_list;
443 if (im) {
444 state->idev = idev;
445 break;
446 }
447 read_unlock_bh(&idev->lock);
448 }
449 return im;
450}
451
452static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
453{
454 struct ac6_iter_state *state = ac6_seq_private(seq);
455
456 im = im->aca_next;
457 while (!im) {
458 if (likely(state->idev != NULL))
459 read_unlock_bh(&state->idev->lock);
460
461 state->dev = next_net_device_rcu(state->dev);
462 if (!state->dev) {
463 state->idev = NULL;
464 break;
465 }
466 state->idev = __in6_dev_get(state->dev);
467 if (!state->idev)
468 continue;
469 read_lock_bh(&state->idev->lock);
470 im = state->idev->ac_list;
471 }
472 return im;
473}
474
475static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
476{
477 struct ifacaddr6 *im = ac6_get_first(seq);
478 if (im)
479 while (pos && (im = ac6_get_next(seq, im)) != NULL)
480 --pos;
481 return pos ? NULL : im;
482}
483
484static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
485 __acquires(RCU)
486{
487 rcu_read_lock();
488 return ac6_get_idx(seq, *pos);
489}
490
491static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
492{
493 struct ifacaddr6 *im = ac6_get_next(seq, v);
494
495 ++*pos;
496 return im;
497}
498
499static void ac6_seq_stop(struct seq_file *seq, void *v)
500 __releases(RCU)
501{
502 struct ac6_iter_state *state = ac6_seq_private(seq);
503
504 if (likely(state->idev != NULL)) {
505 read_unlock_bh(&state->idev->lock);
506 state->idev = NULL;
507 }
508 rcu_read_unlock();
509}
510
511static int ac6_seq_show(struct seq_file *seq, void *v)
512{
513 struct ifacaddr6 *im = (struct ifacaddr6 *)v;
514 struct ac6_iter_state *state = ac6_seq_private(seq);
515
516 seq_printf(seq, "%-4d %-15s %pi6 %5d\n",
517 state->dev->ifindex, state->dev->name,
518 &im->aca_addr, im->aca_users);
519 return 0;
520}
521
522static const struct seq_operations ac6_seq_ops = {
523 .start = ac6_seq_start,
524 .next = ac6_seq_next,
525 .stop = ac6_seq_stop,
526 .show = ac6_seq_show,
527};
528
529static int ac6_seq_open(struct inode *inode, struct file *file)
530{
531 return seq_open_net(inode, file, &ac6_seq_ops,
532 sizeof(struct ac6_iter_state));
533}
534
535static const struct file_operations ac6_seq_fops = {
536 .owner = THIS_MODULE,
537 .open = ac6_seq_open,
538 .read = seq_read,
539 .llseek = seq_lseek,
540 .release = seq_release_net,
541};
542
543int __net_init ac6_proc_init(struct net *net)
544{
545 if (!proc_create("anycast6", S_IRUGO, net->proc_net, &ac6_seq_fops))
546 return -ENOMEM;
547
548 return 0;
549}
550
551void ac6_proc_exit(struct net *net)
552{
553 remove_proc_entry("anycast6", net->proc_net);
554}
555#endif
556