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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// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Anycast support for IPv6
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * David L Stevens (dlstevens@us.ibm.com)
8 *
9 * based heavily on net/ipv6/mcast.c
10 */
11
12#include <linux/capability.h>
13#include <linux/module.h>
14#include <linux/errno.h>
15#include <linux/types.h>
16#include <linux/random.h>
17#include <linux/string.h>
18#include <linux/socket.h>
19#include <linux/sockios.h>
20#include <linux/net.h>
21#include <linux/in6.h>
22#include <linux/netdevice.h>
23#include <linux/if_arp.h>
24#include <linux/route.h>
25#include <linux/init.h>
26#include <linux/proc_fs.h>
27#include <linux/seq_file.h>
28#include <linux/slab.h>
29
30#include <net/net_namespace.h>
31#include <net/sock.h>
32#include <net/snmp.h>
33
34#include <net/ipv6.h>
35#include <net/protocol.h>
36#include <net/if_inet6.h>
37#include <net/ndisc.h>
38#include <net/addrconf.h>
39#include <net/ip6_route.h>
40
41#include <net/checksum.h>
42
43#define IN6_ADDR_HSIZE_SHIFT 8
44#define IN6_ADDR_HSIZE BIT(IN6_ADDR_HSIZE_SHIFT)
45/* anycast address hash table
46 */
47static struct hlist_head inet6_acaddr_lst[IN6_ADDR_HSIZE];
48static DEFINE_SPINLOCK(acaddr_hash_lock);
49
50static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr);
51
52static u32 inet6_acaddr_hash(const struct net *net,
53 const struct in6_addr *addr)
54{
55 u32 val = __ipv6_addr_jhash(addr, net_hash_mix(net));
56
57 return hash_32(val, IN6_ADDR_HSIZE_SHIFT);
58}
59
60/*
61 * socket join an anycast group
62 */
63
64int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
65{
66 struct ipv6_pinfo *np = inet6_sk(sk);
67 struct net_device *dev = NULL;
68 struct inet6_dev *idev;
69 struct ipv6_ac_socklist *pac;
70 struct net *net = sock_net(sk);
71 int ishost = !net->ipv6.devconf_all->forwarding;
72 int err = 0;
73
74 ASSERT_RTNL();
75
76 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
77 return -EPERM;
78 if (ipv6_addr_is_multicast(addr))
79 return -EINVAL;
80
81 if (ifindex)
82 dev = __dev_get_by_index(net, ifindex);
83
84 if (ipv6_chk_addr_and_flags(net, addr, dev, true, 0, IFA_F_TENTATIVE))
85 return -EINVAL;
86
87 pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
88 if (!pac)
89 return -ENOMEM;
90 pac->acl_next = NULL;
91 pac->acl_addr = *addr;
92
93 if (ifindex == 0) {
94 struct rt6_info *rt;
95
96 rt = rt6_lookup(net, addr, NULL, 0, NULL, 0);
97 if (rt) {
98 dev = rt->dst.dev;
99 ip6_rt_put(rt);
100 } else if (ishost) {
101 err = -EADDRNOTAVAIL;
102 goto error;
103 } else {
104 /* router, no matching interface: just pick one */
105 dev = __dev_get_by_flags(net, IFF_UP,
106 IFF_UP | IFF_LOOPBACK);
107 }
108 }
109
110 if (!dev) {
111 err = -ENODEV;
112 goto error;
113 }
114
115 idev = __in6_dev_get(dev);
116 if (!idev) {
117 if (ifindex)
118 err = -ENODEV;
119 else
120 err = -EADDRNOTAVAIL;
121 goto error;
122 }
123 /* reset ishost, now that we have a specific device */
124 ishost = !idev->cnf.forwarding;
125
126 pac->acl_ifindex = dev->ifindex;
127
128 /* XXX
129 * For hosts, allow link-local or matching prefix anycasts.
130 * This obviates the need for propagating anycast routes while
131 * still allowing some non-router anycast participation.
132 */
133 if (!ipv6_chk_prefix(addr, dev)) {
134 if (ishost)
135 err = -EADDRNOTAVAIL;
136 if (err)
137 goto error;
138 }
139
140 err = __ipv6_dev_ac_inc(idev, addr);
141 if (!err) {
142 pac->acl_next = np->ipv6_ac_list;
143 np->ipv6_ac_list = pac;
144 pac = NULL;
145 }
146
147error:
148 if (pac)
149 sock_kfree_s(sk, pac, sizeof(*pac));
150 return err;
151}
152
153/*
154 * socket leave an anycast group
155 */
156int ipv6_sock_ac_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
157{
158 struct ipv6_pinfo *np = inet6_sk(sk);
159 struct net_device *dev;
160 struct ipv6_ac_socklist *pac, *prev_pac;
161 struct net *net = sock_net(sk);
162
163 ASSERT_RTNL();
164
165 prev_pac = NULL;
166 for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
167 if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
168 ipv6_addr_equal(&pac->acl_addr, addr))
169 break;
170 prev_pac = pac;
171 }
172 if (!pac)
173 return -ENOENT;
174 if (prev_pac)
175 prev_pac->acl_next = pac->acl_next;
176 else
177 np->ipv6_ac_list = pac->acl_next;
178
179 dev = __dev_get_by_index(net, pac->acl_ifindex);
180 if (dev)
181 ipv6_dev_ac_dec(dev, &pac->acl_addr);
182
183 sock_kfree_s(sk, pac, sizeof(*pac));
184 return 0;
185}
186
187void __ipv6_sock_ac_close(struct sock *sk)
188{
189 struct ipv6_pinfo *np = inet6_sk(sk);
190 struct net_device *dev = NULL;
191 struct ipv6_ac_socklist *pac;
192 struct net *net = sock_net(sk);
193 int prev_index;
194
195 ASSERT_RTNL();
196 pac = np->ipv6_ac_list;
197 np->ipv6_ac_list = NULL;
198
199 prev_index = 0;
200 while (pac) {
201 struct ipv6_ac_socklist *next = pac->acl_next;
202
203 if (pac->acl_ifindex != prev_index) {
204 dev = __dev_get_by_index(net, pac->acl_ifindex);
205 prev_index = pac->acl_ifindex;
206 }
207 if (dev)
208 ipv6_dev_ac_dec(dev, &pac->acl_addr);
209 sock_kfree_s(sk, pac, sizeof(*pac));
210 pac = next;
211 }
212}
213
214void ipv6_sock_ac_close(struct sock *sk)
215{
216 struct ipv6_pinfo *np = inet6_sk(sk);
217
218 if (!np->ipv6_ac_list)
219 return;
220 rtnl_lock();
221 __ipv6_sock_ac_close(sk);
222 rtnl_unlock();
223}
224
225static void ipv6_add_acaddr_hash(struct net *net, struct ifacaddr6 *aca)
226{
227 unsigned int hash = inet6_acaddr_hash(net, &aca->aca_addr);
228
229 spin_lock(&acaddr_hash_lock);
230 hlist_add_head_rcu(&aca->aca_addr_lst, &inet6_acaddr_lst[hash]);
231 spin_unlock(&acaddr_hash_lock);
232}
233
234static void ipv6_del_acaddr_hash(struct ifacaddr6 *aca)
235{
236 spin_lock(&acaddr_hash_lock);
237 hlist_del_init_rcu(&aca->aca_addr_lst);
238 spin_unlock(&acaddr_hash_lock);
239}
240
241static void aca_get(struct ifacaddr6 *aca)
242{
243 refcount_inc(&aca->aca_refcnt);
244}
245
246static void aca_free_rcu(struct rcu_head *h)
247{
248 struct ifacaddr6 *aca = container_of(h, struct ifacaddr6, rcu);
249
250 fib6_info_release(aca->aca_rt);
251 kfree(aca);
252}
253
254static void aca_put(struct ifacaddr6 *ac)
255{
256 if (refcount_dec_and_test(&ac->aca_refcnt))
257 call_rcu_hurry(&ac->rcu, aca_free_rcu);
258}
259
260static struct ifacaddr6 *aca_alloc(struct fib6_info *f6i,
261 const struct in6_addr *addr)
262{
263 struct ifacaddr6 *aca;
264
265 aca = kzalloc(sizeof(*aca), GFP_ATOMIC);
266 if (!aca)
267 return NULL;
268
269 aca->aca_addr = *addr;
270 fib6_info_hold(f6i);
271 aca->aca_rt = f6i;
272 INIT_HLIST_NODE(&aca->aca_addr_lst);
273 aca->aca_users = 1;
274 /* aca_tstamp should be updated upon changes */
275 aca->aca_cstamp = aca->aca_tstamp = jiffies;
276 refcount_set(&aca->aca_refcnt, 1);
277
278 return aca;
279}
280
281/*
282 * device anycast group inc (add if not found)
283 */
284int __ipv6_dev_ac_inc(struct inet6_dev *idev, const struct in6_addr *addr)
285{
286 struct ifacaddr6 *aca;
287 struct fib6_info *f6i;
288 struct net *net;
289 int err;
290
291 ASSERT_RTNL();
292
293 write_lock_bh(&idev->lock);
294 if (idev->dead) {
295 err = -ENODEV;
296 goto out;
297 }
298
299 for (aca = rtnl_dereference(idev->ac_list); aca;
300 aca = rtnl_dereference(aca->aca_next)) {
301 if (ipv6_addr_equal(&aca->aca_addr, addr)) {
302 aca->aca_users++;
303 err = 0;
304 goto out;
305 }
306 }
307
308 net = dev_net(idev->dev);
309 f6i = addrconf_f6i_alloc(net, idev, addr, true, GFP_ATOMIC, NULL);
310 if (IS_ERR(f6i)) {
311 err = PTR_ERR(f6i);
312 goto out;
313 }
314 aca = aca_alloc(f6i, addr);
315 if (!aca) {
316 fib6_info_release(f6i);
317 err = -ENOMEM;
318 goto out;
319 }
320
321 /* Hold this for addrconf_join_solict() below before we unlock,
322 * it is already exposed via idev->ac_list.
323 */
324 aca_get(aca);
325 aca->aca_next = idev->ac_list;
326 rcu_assign_pointer(idev->ac_list, aca);
327
328 write_unlock_bh(&idev->lock);
329
330 ipv6_add_acaddr_hash(net, aca);
331
332 ip6_ins_rt(net, f6i);
333
334 addrconf_join_solict(idev->dev, &aca->aca_addr);
335
336 aca_put(aca);
337 return 0;
338out:
339 write_unlock_bh(&idev->lock);
340 return err;
341}
342
343/*
344 * device anycast group decrement
345 */
346int __ipv6_dev_ac_dec(struct inet6_dev *idev, const struct in6_addr *addr)
347{
348 struct ifacaddr6 *aca, *prev_aca;
349
350 ASSERT_RTNL();
351
352 write_lock_bh(&idev->lock);
353 prev_aca = NULL;
354 for (aca = rtnl_dereference(idev->ac_list); aca;
355 aca = rtnl_dereference(aca->aca_next)) {
356 if (ipv6_addr_equal(&aca->aca_addr, addr))
357 break;
358 prev_aca = aca;
359 }
360 if (!aca) {
361 write_unlock_bh(&idev->lock);
362 return -ENOENT;
363 }
364 if (--aca->aca_users > 0) {
365 write_unlock_bh(&idev->lock);
366 return 0;
367 }
368 if (prev_aca)
369 rcu_assign_pointer(prev_aca->aca_next, aca->aca_next);
370 else
371 rcu_assign_pointer(idev->ac_list, aca->aca_next);
372 write_unlock_bh(&idev->lock);
373 ipv6_del_acaddr_hash(aca);
374 addrconf_leave_solict(idev, &aca->aca_addr);
375
376 ip6_del_rt(dev_net(idev->dev), aca->aca_rt, false);
377
378 aca_put(aca);
379 return 0;
380}
381
382/* called with rtnl_lock() */
383static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr)
384{
385 struct inet6_dev *idev = __in6_dev_get(dev);
386
387 if (!idev)
388 return -ENODEV;
389 return __ipv6_dev_ac_dec(idev, addr);
390}
391
392void ipv6_ac_destroy_dev(struct inet6_dev *idev)
393{
394 struct ifacaddr6 *aca;
395
396 write_lock_bh(&idev->lock);
397 while ((aca = rtnl_dereference(idev->ac_list)) != NULL) {
398 rcu_assign_pointer(idev->ac_list, aca->aca_next);
399 write_unlock_bh(&idev->lock);
400
401 ipv6_del_acaddr_hash(aca);
402
403 addrconf_leave_solict(idev, &aca->aca_addr);
404
405 ip6_del_rt(dev_net(idev->dev), aca->aca_rt, false);
406
407 aca_put(aca);
408
409 write_lock_bh(&idev->lock);
410 }
411 write_unlock_bh(&idev->lock);
412}
413
414/*
415 * check if the interface has this anycast address
416 * called with rcu_read_lock()
417 */
418static bool ipv6_chk_acast_dev(struct net_device *dev, const struct in6_addr *addr)
419{
420 struct inet6_dev *idev;
421 struct ifacaddr6 *aca;
422
423 idev = __in6_dev_get(dev);
424 if (idev) {
425 for (aca = rcu_dereference(idev->ac_list); aca;
426 aca = rcu_dereference(aca->aca_next))
427 if (ipv6_addr_equal(&aca->aca_addr, addr))
428 break;
429 return aca != NULL;
430 }
431 return false;
432}
433
434/*
435 * check if given interface (or any, if dev==0) has this anycast address
436 */
437bool ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
438 const struct in6_addr *addr)
439{
440 struct net_device *nh_dev;
441 struct ifacaddr6 *aca;
442 bool found = false;
443
444 rcu_read_lock();
445 if (dev)
446 found = ipv6_chk_acast_dev(dev, addr);
447 else {
448 unsigned int hash = inet6_acaddr_hash(net, addr);
449
450 hlist_for_each_entry_rcu(aca, &inet6_acaddr_lst[hash],
451 aca_addr_lst) {
452 nh_dev = fib6_info_nh_dev(aca->aca_rt);
453 if (!nh_dev || !net_eq(dev_net(nh_dev), net))
454 continue;
455 if (ipv6_addr_equal(&aca->aca_addr, addr)) {
456 found = true;
457 break;
458 }
459 }
460 }
461 rcu_read_unlock();
462 return found;
463}
464
465/* check if this anycast address is link-local on given interface or
466 * is global
467 */
468bool ipv6_chk_acast_addr_src(struct net *net, struct net_device *dev,
469 const struct in6_addr *addr)
470{
471 return ipv6_chk_acast_addr(net,
472 (ipv6_addr_type(addr) & IPV6_ADDR_LINKLOCAL ?
473 dev : NULL),
474 addr);
475}
476
477#ifdef CONFIG_PROC_FS
478struct ac6_iter_state {
479 struct seq_net_private p;
480 struct net_device *dev;
481};
482
483#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
484
485static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
486{
487 struct ac6_iter_state *state = ac6_seq_private(seq);
488 struct net *net = seq_file_net(seq);
489 struct ifacaddr6 *im = NULL;
490
491 for_each_netdev_rcu(net, state->dev) {
492 struct inet6_dev *idev;
493
494 idev = __in6_dev_get(state->dev);
495 if (!idev)
496 continue;
497 im = rcu_dereference(idev->ac_list);
498 if (im)
499 break;
500 }
501 return im;
502}
503
504static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
505{
506 struct ac6_iter_state *state = ac6_seq_private(seq);
507 struct inet6_dev *idev;
508
509 im = rcu_dereference(im->aca_next);
510 while (!im) {
511 state->dev = next_net_device_rcu(state->dev);
512 if (!state->dev)
513 break;
514 idev = __in6_dev_get(state->dev);
515 if (!idev)
516 continue;
517 im = rcu_dereference(idev->ac_list);
518 }
519 return im;
520}
521
522static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
523{
524 struct ifacaddr6 *im = ac6_get_first(seq);
525 if (im)
526 while (pos && (im = ac6_get_next(seq, im)) != NULL)
527 --pos;
528 return pos ? NULL : im;
529}
530
531static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
532 __acquires(RCU)
533{
534 rcu_read_lock();
535 return ac6_get_idx(seq, *pos);
536}
537
538static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
539{
540 struct ifacaddr6 *im = ac6_get_next(seq, v);
541
542 ++*pos;
543 return im;
544}
545
546static void ac6_seq_stop(struct seq_file *seq, void *v)
547 __releases(RCU)
548{
549 rcu_read_unlock();
550}
551
552static int ac6_seq_show(struct seq_file *seq, void *v)
553{
554 struct ifacaddr6 *im = (struct ifacaddr6 *)v;
555 struct ac6_iter_state *state = ac6_seq_private(seq);
556
557 seq_printf(seq, "%-4d %-15s %pi6 %5d\n",
558 state->dev->ifindex, state->dev->name,
559 &im->aca_addr, im->aca_users);
560 return 0;
561}
562
563static const struct seq_operations ac6_seq_ops = {
564 .start = ac6_seq_start,
565 .next = ac6_seq_next,
566 .stop = ac6_seq_stop,
567 .show = ac6_seq_show,
568};
569
570int __net_init ac6_proc_init(struct net *net)
571{
572 if (!proc_create_net("anycast6", 0444, net->proc_net, &ac6_seq_ops,
573 sizeof(struct ac6_iter_state)))
574 return -ENOMEM;
575
576 return 0;
577}
578
579void ac6_proc_exit(struct net *net)
580{
581 remove_proc_entry("anycast6", net->proc_net);
582}
583#endif
584
585/* Init / cleanup code
586 */
587int __init ipv6_anycast_init(void)
588{
589 int i;
590
591 for (i = 0; i < IN6_ADDR_HSIZE; i++)
592 INIT_HLIST_HEAD(&inet6_acaddr_lst[i]);
593 return 0;
594}
595
596void ipv6_anycast_cleanup(void)
597{
598 int i;
599
600 spin_lock(&acaddr_hash_lock);
601 for (i = 0; i < IN6_ADDR_HSIZE; i++)
602 WARN_ON(!hlist_empty(&inet6_acaddr_lst[i]));
603 spin_unlock(&acaddr_hash_lock);
604}