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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
70 if (ifindex)
71 dev = __dev_get_by_index(net, ifindex);
72
73 if (ipv6_chk_addr_and_flags(net, addr, dev, true, 0, IFA_F_TENTATIVE))
74 return -EINVAL;
75
76 pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
77 if (!pac)
78 return -ENOMEM;
79 pac->acl_next = NULL;
80 pac->acl_addr = *addr;
81
82 if (ifindex == 0) {
83 struct rt6_info *rt;
84
85 rt = rt6_lookup(net, addr, NULL, 0, NULL, 0);
86 if (rt) {
87 dev = rt->dst.dev;
88 ip6_rt_put(rt);
89 } else if (ishost) {
90 err = -EADDRNOTAVAIL;
91 goto error;
92 } else {
93 /* router, no matching interface: just pick one */
94 dev = __dev_get_by_flags(net, IFF_UP,
95 IFF_UP | IFF_LOOPBACK);
96 }
97 }
98
99 if (!dev) {
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(idev, addr);
130 if (!err) {
131 pac->acl_next = np->ipv6_ac_list;
132 np->ipv6_ac_list = pac;
133 pac = NULL;
134 }
135
136error:
137 if (pac)
138 sock_kfree_s(sk, pac, sizeof(*pac));
139 return err;
140}
141
142/*
143 * socket leave an anycast group
144 */
145int ipv6_sock_ac_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
146{
147 struct ipv6_pinfo *np = inet6_sk(sk);
148 struct net_device *dev;
149 struct ipv6_ac_socklist *pac, *prev_pac;
150 struct net *net = sock_net(sk);
151
152 ASSERT_RTNL();
153
154 prev_pac = NULL;
155 for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
156 if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
157 ipv6_addr_equal(&pac->acl_addr, addr))
158 break;
159 prev_pac = pac;
160 }
161 if (!pac)
162 return -ENOENT;
163 if (prev_pac)
164 prev_pac->acl_next = pac->acl_next;
165 else
166 np->ipv6_ac_list = pac->acl_next;
167
168 dev = __dev_get_by_index(net, pac->acl_ifindex);
169 if (dev)
170 ipv6_dev_ac_dec(dev, &pac->acl_addr);
171
172 sock_kfree_s(sk, pac, sizeof(*pac));
173 return 0;
174}
175
176void ipv6_sock_ac_close(struct sock *sk)
177{
178 struct ipv6_pinfo *np = inet6_sk(sk);
179 struct net_device *dev = NULL;
180 struct ipv6_ac_socklist *pac;
181 struct net *net = sock_net(sk);
182 int prev_index;
183
184 if (!np->ipv6_ac_list)
185 return;
186
187 rtnl_lock();
188 pac = np->ipv6_ac_list;
189 np->ipv6_ac_list = NULL;
190
191 prev_index = 0;
192 while (pac) {
193 struct ipv6_ac_socklist *next = pac->acl_next;
194
195 if (pac->acl_ifindex != prev_index) {
196 dev = __dev_get_by_index(net, pac->acl_ifindex);
197 prev_index = pac->acl_ifindex;
198 }
199 if (dev)
200 ipv6_dev_ac_dec(dev, &pac->acl_addr);
201 sock_kfree_s(sk, pac, sizeof(*pac));
202 pac = next;
203 }
204 rtnl_unlock();
205}
206
207static void aca_get(struct ifacaddr6 *aca)
208{
209 refcount_inc(&aca->aca_refcnt);
210}
211
212static void aca_put(struct ifacaddr6 *ac)
213{
214 if (refcount_dec_and_test(&ac->aca_refcnt)) {
215 in6_dev_put(ac->aca_idev);
216 dst_release(&ac->aca_rt->dst);
217 kfree(ac);
218 }
219}
220
221static struct ifacaddr6 *aca_alloc(struct rt6_info *rt,
222 const struct in6_addr *addr)
223{
224 struct inet6_dev *idev = rt->rt6i_idev;
225 struct ifacaddr6 *aca;
226
227 aca = kzalloc(sizeof(*aca), GFP_ATOMIC);
228 if (!aca)
229 return NULL;
230
231 aca->aca_addr = *addr;
232 in6_dev_hold(idev);
233 aca->aca_idev = idev;
234 aca->aca_rt = rt;
235 aca->aca_users = 1;
236 /* aca_tstamp should be updated upon changes */
237 aca->aca_cstamp = aca->aca_tstamp = jiffies;
238 refcount_set(&aca->aca_refcnt, 1);
239
240 return aca;
241}
242
243/*
244 * device anycast group inc (add if not found)
245 */
246int __ipv6_dev_ac_inc(struct inet6_dev *idev, const struct in6_addr *addr)
247{
248 struct ifacaddr6 *aca;
249 struct rt6_info *rt;
250 int err;
251
252 ASSERT_RTNL();
253
254 write_lock_bh(&idev->lock);
255 if (idev->dead) {
256 err = -ENODEV;
257 goto out;
258 }
259
260 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
261 if (ipv6_addr_equal(&aca->aca_addr, addr)) {
262 aca->aca_users++;
263 err = 0;
264 goto out;
265 }
266 }
267
268 rt = addrconf_dst_alloc(idev, addr, true);
269 if (IS_ERR(rt)) {
270 err = PTR_ERR(rt);
271 goto out;
272 }
273 aca = aca_alloc(rt, addr);
274 if (!aca) {
275 ip6_rt_put(rt);
276 err = -ENOMEM;
277 goto out;
278 }
279
280 aca->aca_next = idev->ac_list;
281 idev->ac_list = aca;
282
283 /* Hold this for addrconf_join_solict() below before we unlock,
284 * it is already exposed via idev->ac_list.
285 */
286 aca_get(aca);
287 write_unlock_bh(&idev->lock);
288
289 ip6_ins_rt(rt);
290
291 addrconf_join_solict(idev->dev, &aca->aca_addr);
292
293 aca_put(aca);
294 return 0;
295out:
296 write_unlock_bh(&idev->lock);
297 return err;
298}
299
300/*
301 * device anycast group decrement
302 */
303int __ipv6_dev_ac_dec(struct inet6_dev *idev, const struct in6_addr *addr)
304{
305 struct ifacaddr6 *aca, *prev_aca;
306
307 ASSERT_RTNL();
308
309 write_lock_bh(&idev->lock);
310 prev_aca = NULL;
311 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
312 if (ipv6_addr_equal(&aca->aca_addr, addr))
313 break;
314 prev_aca = aca;
315 }
316 if (!aca) {
317 write_unlock_bh(&idev->lock);
318 return -ENOENT;
319 }
320 if (--aca->aca_users > 0) {
321 write_unlock_bh(&idev->lock);
322 return 0;
323 }
324 if (prev_aca)
325 prev_aca->aca_next = aca->aca_next;
326 else
327 idev->ac_list = aca->aca_next;
328 write_unlock_bh(&idev->lock);
329 addrconf_leave_solict(idev, &aca->aca_addr);
330
331 dst_hold(&aca->aca_rt->dst);
332 ip6_del_rt(aca->aca_rt);
333
334 aca_put(aca);
335 return 0;
336}
337
338/* called with rtnl_lock() */
339static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr)
340{
341 struct inet6_dev *idev = __in6_dev_get(dev);
342
343 if (!idev)
344 return -ENODEV;
345 return __ipv6_dev_ac_dec(idev, addr);
346}
347
348void ipv6_ac_destroy_dev(struct inet6_dev *idev)
349{
350 struct ifacaddr6 *aca;
351
352 write_lock_bh(&idev->lock);
353 while ((aca = idev->ac_list) != NULL) {
354 idev->ac_list = aca->aca_next;
355 write_unlock_bh(&idev->lock);
356
357 addrconf_leave_solict(idev, &aca->aca_addr);
358
359 dst_hold(&aca->aca_rt->dst);
360 ip6_del_rt(aca->aca_rt);
361
362 aca_put(aca);
363
364 write_lock_bh(&idev->lock);
365 }
366 write_unlock_bh(&idev->lock);
367}
368
369/*
370 * check if the interface has this anycast address
371 * called with rcu_read_lock()
372 */
373static bool ipv6_chk_acast_dev(struct net_device *dev, const struct in6_addr *addr)
374{
375 struct inet6_dev *idev;
376 struct ifacaddr6 *aca;
377
378 idev = __in6_dev_get(dev);
379 if (idev) {
380 read_lock_bh(&idev->lock);
381 for (aca = idev->ac_list; aca; aca = aca->aca_next)
382 if (ipv6_addr_equal(&aca->aca_addr, addr))
383 break;
384 read_unlock_bh(&idev->lock);
385 return aca != NULL;
386 }
387 return false;
388}
389
390/*
391 * check if given interface (or any, if dev==0) has this anycast address
392 */
393bool ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
394 const struct in6_addr *addr)
395{
396 bool found = false;
397
398 rcu_read_lock();
399 if (dev)
400 found = ipv6_chk_acast_dev(dev, addr);
401 else
402 for_each_netdev_rcu(net, dev)
403 if (ipv6_chk_acast_dev(dev, addr)) {
404 found = true;
405 break;
406 }
407 rcu_read_unlock();
408 return found;
409}
410
411/* check if this anycast address is link-local on given interface or
412 * is global
413 */
414bool ipv6_chk_acast_addr_src(struct net *net, struct net_device *dev,
415 const struct in6_addr *addr)
416{
417 return ipv6_chk_acast_addr(net,
418 (ipv6_addr_type(addr) & IPV6_ADDR_LINKLOCAL ?
419 dev : NULL),
420 addr);
421}
422
423#ifdef CONFIG_PROC_FS
424struct ac6_iter_state {
425 struct seq_net_private p;
426 struct net_device *dev;
427 struct inet6_dev *idev;
428};
429
430#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
431
432static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
433{
434 struct ifacaddr6 *im = NULL;
435 struct ac6_iter_state *state = ac6_seq_private(seq);
436 struct net *net = seq_file_net(seq);
437
438 state->idev = NULL;
439 for_each_netdev_rcu(net, state->dev) {
440 struct inet6_dev *idev;
441 idev = __in6_dev_get(state->dev);
442 if (!idev)
443 continue;
444 read_lock_bh(&idev->lock);
445 im = idev->ac_list;
446 if (im) {
447 state->idev = idev;
448 break;
449 }
450 read_unlock_bh(&idev->lock);
451 }
452 return im;
453}
454
455static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
456{
457 struct ac6_iter_state *state = ac6_seq_private(seq);
458
459 im = im->aca_next;
460 while (!im) {
461 if (likely(state->idev != NULL))
462 read_unlock_bh(&state->idev->lock);
463
464 state->dev = next_net_device_rcu(state->dev);
465 if (!state->dev) {
466 state->idev = NULL;
467 break;
468 }
469 state->idev = __in6_dev_get(state->dev);
470 if (!state->idev)
471 continue;
472 read_lock_bh(&state->idev->lock);
473 im = state->idev->ac_list;
474 }
475 return im;
476}
477
478static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
479{
480 struct ifacaddr6 *im = ac6_get_first(seq);
481 if (im)
482 while (pos && (im = ac6_get_next(seq, im)) != NULL)
483 --pos;
484 return pos ? NULL : im;
485}
486
487static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
488 __acquires(RCU)
489{
490 rcu_read_lock();
491 return ac6_get_idx(seq, *pos);
492}
493
494static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
495{
496 struct ifacaddr6 *im = ac6_get_next(seq, v);
497
498 ++*pos;
499 return im;
500}
501
502static void ac6_seq_stop(struct seq_file *seq, void *v)
503 __releases(RCU)
504{
505 struct ac6_iter_state *state = ac6_seq_private(seq);
506
507 if (likely(state->idev != NULL)) {
508 read_unlock_bh(&state->idev->lock);
509 state->idev = NULL;
510 }
511 rcu_read_unlock();
512}
513
514static int ac6_seq_show(struct seq_file *seq, void *v)
515{
516 struct ifacaddr6 *im = (struct ifacaddr6 *)v;
517 struct ac6_iter_state *state = ac6_seq_private(seq);
518
519 seq_printf(seq, "%-4d %-15s %pi6 %5d\n",
520 state->dev->ifindex, state->dev->name,
521 &im->aca_addr, im->aca_users);
522 return 0;
523}
524
525static const struct seq_operations ac6_seq_ops = {
526 .start = ac6_seq_start,
527 .next = ac6_seq_next,
528 .stop = ac6_seq_stop,
529 .show = ac6_seq_show,
530};
531
532static int ac6_seq_open(struct inode *inode, struct file *file)
533{
534 return seq_open_net(inode, file, &ac6_seq_ops,
535 sizeof(struct ac6_iter_state));
536}
537
538static const struct file_operations ac6_seq_fops = {
539 .open = ac6_seq_open,
540 .read = seq_read,
541 .llseek = seq_lseek,
542 .release = seq_release_net,
543};
544
545int __net_init ac6_proc_init(struct net *net)
546{
547 if (!proc_create("anycast6", 0444, net->proc_net, &ac6_seq_fops))
548 return -ENOMEM;
549
550 return 0;
551}
552
553void ac6_proc_exit(struct net *net)
554{
555 remove_proc_entry("anycast6", net->proc_net);
556}
557#endif
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_SPINLOCK(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 (!ns_capable(net->user_ns, 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 ip6_rt_put(rt);
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 spin_lock_bh(&ipv6_sk_ac_lock);
132 pac->acl_next = np->ipv6_ac_list;
133 np->ipv6_ac_list = pac;
134 spin_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 spin_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 spin_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 spin_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 if (!np->ipv6_ac_list)
193 return;
194
195 spin_lock_bh(&ipv6_sk_ac_lock);
196 pac = np->ipv6_ac_list;
197 np->ipv6_ac_list = NULL;
198 spin_unlock_bh(&ipv6_sk_ac_lock);
199
200 prev_index = 0;
201 rcu_read_lock();
202 while (pac) {
203 struct ipv6_ac_socklist *next = pac->acl_next;
204
205 if (pac->acl_ifindex != prev_index) {
206 dev = dev_get_by_index_rcu(net, pac->acl_ifindex);
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 }
214 rcu_read_unlock();
215}
216
217static void aca_put(struct ifacaddr6 *ac)
218{
219 if (atomic_dec_and_test(&ac->aca_refcnt)) {
220 in6_dev_put(ac->aca_idev);
221 dst_release(&ac->aca_rt->dst);
222 kfree(ac);
223 }
224}
225
226/*
227 * device anycast group inc (add if not found)
228 */
229int ipv6_dev_ac_inc(struct net_device *dev, const struct in6_addr *addr)
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
259 aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
260
261 if (aca == NULL) {
262 err = -ENOMEM;
263 goto out;
264 }
265
266 rt = addrconf_dst_alloc(idev, addr, true);
267 if (IS_ERR(rt)) {
268 kfree(aca);
269 err = PTR_ERR(rt);
270 goto out;
271 }
272
273 aca->aca_addr = *addr;
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
286 ip6_ins_rt(rt);
287
288 addrconf_join_solict(dev, &aca->aca_addr);
289
290 aca_put(aca);
291 return 0;
292out:
293 write_unlock_bh(&idev->lock);
294 in6_dev_put(idev);
295 return err;
296}
297
298/*
299 * device anycast group decrement
300 */
301int __ipv6_dev_ac_dec(struct inet6_dev *idev, const struct in6_addr *addr)
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
327 dst_hold(&aca->aca_rt->dst);
328 ip6_del_rt(aca->aca_rt);
329
330 aca_put(aca);
331 return 0;
332}
333
334/* called with rcu_read_lock() */
335static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr)
336{
337 struct inet6_dev *idev = __in6_dev_get(dev);
338
339 if (idev == NULL)
340 return -ENODEV;
341 return __ipv6_dev_ac_dec(idev, addr);
342}
343
344/*
345 * check if the interface has this anycast address
346 * called with rcu_read_lock()
347 */
348static bool ipv6_chk_acast_dev(struct net_device *dev, const struct in6_addr *addr)
349{
350 struct inet6_dev *idev;
351 struct ifacaddr6 *aca;
352
353 idev = __in6_dev_get(dev);
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);
360 return aca != NULL;
361 }
362 return false;
363}
364
365/*
366 * check if given interface (or any, if dev==0) has this anycast address
367 */
368bool ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
369 const struct in6_addr *addr)
370{
371 bool found = false;
372
373 rcu_read_lock();
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)) {
379 found = true;
380 break;
381 }
382 rcu_read_unlock();
383 return found;
384}
385
386/* check if this anycast address is link-local on given interface or
387 * is global
388 */
389bool ipv6_chk_acast_addr_src(struct net *net, struct net_device *dev,
390 const struct in6_addr *addr)
391{
392 return ipv6_chk_acast_addr(net,
393 (ipv6_addr_type(addr) & IPV6_ADDR_LINKLOCAL ?
394 dev : NULL),
395 addr);
396}
397
398#ifdef CONFIG_PROC_FS
399struct ac6_iter_state {
400 struct seq_net_private p;
401 struct net_device *dev;
402 struct inet6_dev *idev;
403};
404
405#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
406
407static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
408{
409 struct ifacaddr6 *im = NULL;
410 struct ac6_iter_state *state = ac6_seq_private(seq);
411 struct net *net = seq_file_net(seq);
412
413 state->idev = NULL;
414 for_each_netdev_rcu(net, state->dev) {
415 struct inet6_dev *idev;
416 idev = __in6_dev_get(state->dev);
417 if (!idev)
418 continue;
419 read_lock_bh(&idev->lock);
420 im = idev->ac_list;
421 if (im) {
422 state->idev = idev;
423 break;
424 }
425 read_unlock_bh(&idev->lock);
426 }
427 return im;
428}
429
430static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
431{
432 struct ac6_iter_state *state = ac6_seq_private(seq);
433
434 im = im->aca_next;
435 while (!im) {
436 if (likely(state->idev != NULL))
437 read_unlock_bh(&state->idev->lock);
438
439 state->dev = next_net_device_rcu(state->dev);
440 if (!state->dev) {
441 state->idev = NULL;
442 break;
443 }
444 state->idev = __in6_dev_get(state->dev);
445 if (!state->idev)
446 continue;
447 read_lock_bh(&state->idev->lock);
448 im = state->idev->ac_list;
449 }
450 return im;
451}
452
453static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
454{
455 struct ifacaddr6 *im = ac6_get_first(seq);
456 if (im)
457 while (pos && (im = ac6_get_next(seq, im)) != NULL)
458 --pos;
459 return pos ? NULL : im;
460}
461
462static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
463 __acquires(RCU)
464{
465 rcu_read_lock();
466 return ac6_get_idx(seq, *pos);
467}
468
469static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
470{
471 struct ifacaddr6 *im = ac6_get_next(seq, v);
472
473 ++*pos;
474 return im;
475}
476
477static void ac6_seq_stop(struct seq_file *seq, void *v)
478 __releases(RCU)
479{
480 struct ac6_iter_state *state = ac6_seq_private(seq);
481
482 if (likely(state->idev != NULL)) {
483 read_unlock_bh(&state->idev->lock);
484 state->idev = NULL;
485 }
486 rcu_read_unlock();
487}
488
489static int ac6_seq_show(struct seq_file *seq, void *v)
490{
491 struct ifacaddr6 *im = (struct ifacaddr6 *)v;
492 struct ac6_iter_state *state = ac6_seq_private(seq);
493
494 seq_printf(seq, "%-4d %-15s %pi6 %5d\n",
495 state->dev->ifindex, state->dev->name,
496 &im->aca_addr, im->aca_users);
497 return 0;
498}
499
500static const struct seq_operations ac6_seq_ops = {
501 .start = ac6_seq_start,
502 .next = ac6_seq_next,
503 .stop = ac6_seq_stop,
504 .show = ac6_seq_show,
505};
506
507static int ac6_seq_open(struct inode *inode, struct file *file)
508{
509 return seq_open_net(inode, file, &ac6_seq_ops,
510 sizeof(struct ac6_iter_state));
511}
512
513static const struct file_operations ac6_seq_fops = {
514 .owner = THIS_MODULE,
515 .open = ac6_seq_open,
516 .read = seq_read,
517 .llseek = seq_lseek,
518 .release = seq_release_net,
519};
520
521int __net_init ac6_proc_init(struct net *net)
522{
523 if (!proc_create("anycast6", S_IRUGO, net->proc_net, &ac6_seq_fops))
524 return -ENOMEM;
525
526 return 0;
527}
528
529void ac6_proc_exit(struct net *net)
530{
531 remove_proc_entry("anycast6", net->proc_net);
532}
533#endif
534