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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(struct net *net, const struct in6_addr *addr)
53{
54 u32 val = ipv6_addr_hash(addr) ^ net_hash_mix(net);
55
56 return hash_32(val, IN6_ADDR_HSIZE_SHIFT);
57}
58
59/*
60 * socket join an anycast group
61 */
62
63int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
64{
65 struct ipv6_pinfo *np = inet6_sk(sk);
66 struct net_device *dev = NULL;
67 struct inet6_dev *idev;
68 struct ipv6_ac_socklist *pac;
69 struct net *net = sock_net(sk);
70 int ishost = !net->ipv6.devconf_all->forwarding;
71 int err = 0;
72
73 ASSERT_RTNL();
74
75 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
76 return -EPERM;
77 if (ipv6_addr_is_multicast(addr))
78 return -EINVAL;
79
80 if (ifindex)
81 dev = __dev_get_by_index(net, ifindex);
82
83 if (ipv6_chk_addr_and_flags(net, addr, dev, true, 0, IFA_F_TENTATIVE))
84 return -EINVAL;
85
86 pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
87 if (!pac)
88 return -ENOMEM;
89 pac->acl_next = NULL;
90 pac->acl_addr = *addr;
91
92 if (ifindex == 0) {
93 struct rt6_info *rt;
94
95 rt = rt6_lookup(net, addr, NULL, 0, NULL, 0);
96 if (rt) {
97 dev = rt->dst.dev;
98 ip6_rt_put(rt);
99 } else if (ishost) {
100 err = -EADDRNOTAVAIL;
101 goto error;
102 } else {
103 /* router, no matching interface: just pick one */
104 dev = __dev_get_by_flags(net, IFF_UP,
105 IFF_UP | IFF_LOOPBACK);
106 }
107 }
108
109 if (!dev) {
110 err = -ENODEV;
111 goto error;
112 }
113
114 idev = __in6_dev_get(dev);
115 if (!idev) {
116 if (ifindex)
117 err = -ENODEV;
118 else
119 err = -EADDRNOTAVAIL;
120 goto error;
121 }
122 /* reset ishost, now that we have a specific device */
123 ishost = !idev->cnf.forwarding;
124
125 pac->acl_ifindex = dev->ifindex;
126
127 /* XXX
128 * For hosts, allow link-local or matching prefix anycasts.
129 * This obviates the need for propagating anycast routes while
130 * still allowing some non-router anycast participation.
131 */
132 if (!ipv6_chk_prefix(addr, dev)) {
133 if (ishost)
134 err = -EADDRNOTAVAIL;
135 if (err)
136 goto error;
137 }
138
139 err = __ipv6_dev_ac_inc(idev, addr);
140 if (!err) {
141 pac->acl_next = np->ipv6_ac_list;
142 np->ipv6_ac_list = pac;
143 pac = NULL;
144 }
145
146error:
147 if (pac)
148 sock_kfree_s(sk, pac, sizeof(*pac));
149 return err;
150}
151
152/*
153 * socket leave an anycast group
154 */
155int ipv6_sock_ac_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
156{
157 struct ipv6_pinfo *np = inet6_sk(sk);
158 struct net_device *dev;
159 struct ipv6_ac_socklist *pac, *prev_pac;
160 struct net *net = sock_net(sk);
161
162 ASSERT_RTNL();
163
164 prev_pac = NULL;
165 for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
166 if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
167 ipv6_addr_equal(&pac->acl_addr, addr))
168 break;
169 prev_pac = pac;
170 }
171 if (!pac)
172 return -ENOENT;
173 if (prev_pac)
174 prev_pac->acl_next = pac->acl_next;
175 else
176 np->ipv6_ac_list = pac->acl_next;
177
178 dev = __dev_get_by_index(net, pac->acl_ifindex);
179 if (dev)
180 ipv6_dev_ac_dec(dev, &pac->acl_addr);
181
182 sock_kfree_s(sk, pac, sizeof(*pac));
183 return 0;
184}
185
186void __ipv6_sock_ac_close(struct sock *sk)
187{
188 struct ipv6_pinfo *np = inet6_sk(sk);
189 struct net_device *dev = NULL;
190 struct ipv6_ac_socklist *pac;
191 struct net *net = sock_net(sk);
192 int prev_index;
193
194 ASSERT_RTNL();
195 pac = np->ipv6_ac_list;
196 np->ipv6_ac_list = NULL;
197
198 prev_index = 0;
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(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}
212
213void ipv6_sock_ac_close(struct sock *sk)
214{
215 struct ipv6_pinfo *np = inet6_sk(sk);
216
217 if (!np->ipv6_ac_list)
218 return;
219 rtnl_lock();
220 __ipv6_sock_ac_close(sk);
221 rtnl_unlock();
222}
223
224static void ipv6_add_acaddr_hash(struct net *net, struct ifacaddr6 *aca)
225{
226 unsigned int hash = inet6_acaddr_hash(net, &aca->aca_addr);
227
228 spin_lock(&acaddr_hash_lock);
229 hlist_add_head_rcu(&aca->aca_addr_lst, &inet6_acaddr_lst[hash]);
230 spin_unlock(&acaddr_hash_lock);
231}
232
233static void ipv6_del_acaddr_hash(struct ifacaddr6 *aca)
234{
235 spin_lock(&acaddr_hash_lock);
236 hlist_del_init_rcu(&aca->aca_addr_lst);
237 spin_unlock(&acaddr_hash_lock);
238}
239
240static void aca_get(struct ifacaddr6 *aca)
241{
242 refcount_inc(&aca->aca_refcnt);
243}
244
245static void aca_free_rcu(struct rcu_head *h)
246{
247 struct ifacaddr6 *aca = container_of(h, struct ifacaddr6, rcu);
248
249 fib6_info_release(aca->aca_rt);
250 kfree(aca);
251}
252
253static void aca_put(struct ifacaddr6 *ac)
254{
255 if (refcount_dec_and_test(&ac->aca_refcnt)) {
256 call_rcu(&ac->rcu, aca_free_rcu);
257 }
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 = idev->ac_list; aca; aca = aca->aca_next) {
300 if (ipv6_addr_equal(&aca->aca_addr, addr)) {
301 aca->aca_users++;
302 err = 0;
303 goto out;
304 }
305 }
306
307 net = dev_net(idev->dev);
308 f6i = addrconf_f6i_alloc(net, idev, addr, true, GFP_ATOMIC);
309 if (IS_ERR(f6i)) {
310 err = PTR_ERR(f6i);
311 goto out;
312 }
313 aca = aca_alloc(f6i, addr);
314 if (!aca) {
315 fib6_info_release(f6i);
316 err = -ENOMEM;
317 goto out;
318 }
319
320 aca->aca_next = idev->ac_list;
321 idev->ac_list = aca;
322
323 /* Hold this for addrconf_join_solict() below before we unlock,
324 * it is already exposed via idev->ac_list.
325 */
326 aca_get(aca);
327 write_unlock_bh(&idev->lock);
328
329 ipv6_add_acaddr_hash(net, aca);
330
331 ip6_ins_rt(net, f6i);
332
333 addrconf_join_solict(idev->dev, &aca->aca_addr);
334
335 aca_put(aca);
336 return 0;
337out:
338 write_unlock_bh(&idev->lock);
339 return err;
340}
341
342/*
343 * device anycast group decrement
344 */
345int __ipv6_dev_ac_dec(struct inet6_dev *idev, const struct in6_addr *addr)
346{
347 struct ifacaddr6 *aca, *prev_aca;
348
349 ASSERT_RTNL();
350
351 write_lock_bh(&idev->lock);
352 prev_aca = NULL;
353 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
354 if (ipv6_addr_equal(&aca->aca_addr, addr))
355 break;
356 prev_aca = aca;
357 }
358 if (!aca) {
359 write_unlock_bh(&idev->lock);
360 return -ENOENT;
361 }
362 if (--aca->aca_users > 0) {
363 write_unlock_bh(&idev->lock);
364 return 0;
365 }
366 if (prev_aca)
367 prev_aca->aca_next = aca->aca_next;
368 else
369 idev->ac_list = aca->aca_next;
370 write_unlock_bh(&idev->lock);
371 ipv6_del_acaddr_hash(aca);
372 addrconf_leave_solict(idev, &aca->aca_addr);
373
374 ip6_del_rt(dev_net(idev->dev), aca->aca_rt, false);
375
376 aca_put(aca);
377 return 0;
378}
379
380/* called with rtnl_lock() */
381static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr)
382{
383 struct inet6_dev *idev = __in6_dev_get(dev);
384
385 if (!idev)
386 return -ENODEV;
387 return __ipv6_dev_ac_dec(idev, addr);
388}
389
390void ipv6_ac_destroy_dev(struct inet6_dev *idev)
391{
392 struct ifacaddr6 *aca;
393
394 write_lock_bh(&idev->lock);
395 while ((aca = idev->ac_list) != NULL) {
396 idev->ac_list = aca->aca_next;
397 write_unlock_bh(&idev->lock);
398
399 ipv6_del_acaddr_hash(aca);
400
401 addrconf_leave_solict(idev, &aca->aca_addr);
402
403 ip6_del_rt(dev_net(idev->dev), aca->aca_rt, false);
404
405 aca_put(aca);
406
407 write_lock_bh(&idev->lock);
408 }
409 write_unlock_bh(&idev->lock);
410}
411
412/*
413 * check if the interface has this anycast address
414 * called with rcu_read_lock()
415 */
416static bool ipv6_chk_acast_dev(struct net_device *dev, const struct in6_addr *addr)
417{
418 struct inet6_dev *idev;
419 struct ifacaddr6 *aca;
420
421 idev = __in6_dev_get(dev);
422 if (idev) {
423 read_lock_bh(&idev->lock);
424 for (aca = idev->ac_list; aca; aca = aca->aca_next)
425 if (ipv6_addr_equal(&aca->aca_addr, addr))
426 break;
427 read_unlock_bh(&idev->lock);
428 return aca != NULL;
429 }
430 return false;
431}
432
433/*
434 * check if given interface (or any, if dev==0) has this anycast address
435 */
436bool ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
437 const struct in6_addr *addr)
438{
439 struct net_device *nh_dev;
440 struct ifacaddr6 *aca;
441 bool found = false;
442
443 rcu_read_lock();
444 if (dev)
445 found = ipv6_chk_acast_dev(dev, addr);
446 else {
447 unsigned int hash = inet6_acaddr_hash(net, addr);
448
449 hlist_for_each_entry_rcu(aca, &inet6_acaddr_lst[hash],
450 aca_addr_lst) {
451 nh_dev = fib6_info_nh_dev(aca->aca_rt);
452 if (!nh_dev || !net_eq(dev_net(nh_dev), net))
453 continue;
454 if (ipv6_addr_equal(&aca->aca_addr, addr)) {
455 found = true;
456 break;
457 }
458 }
459 }
460 rcu_read_unlock();
461 return found;
462}
463
464/* check if this anycast address is link-local on given interface or
465 * is global
466 */
467bool ipv6_chk_acast_addr_src(struct net *net, struct net_device *dev,
468 const struct in6_addr *addr)
469{
470 return ipv6_chk_acast_addr(net,
471 (ipv6_addr_type(addr) & IPV6_ADDR_LINKLOCAL ?
472 dev : NULL),
473 addr);
474}
475
476#ifdef CONFIG_PROC_FS
477struct ac6_iter_state {
478 struct seq_net_private p;
479 struct net_device *dev;
480 struct inet6_dev *idev;
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 ifacaddr6 *im = NULL;
488 struct ac6_iter_state *state = ac6_seq_private(seq);
489 struct net *net = seq_file_net(seq);
490
491 state->idev = NULL;
492 for_each_netdev_rcu(net, state->dev) {
493 struct inet6_dev *idev;
494 idev = __in6_dev_get(state->dev);
495 if (!idev)
496 continue;
497 read_lock_bh(&idev->lock);
498 im = idev->ac_list;
499 if (im) {
500 state->idev = idev;
501 break;
502 }
503 read_unlock_bh(&idev->lock);
504 }
505 return im;
506}
507
508static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
509{
510 struct ac6_iter_state *state = ac6_seq_private(seq);
511
512 im = im->aca_next;
513 while (!im) {
514 if (likely(state->idev != NULL))
515 read_unlock_bh(&state->idev->lock);
516
517 state->dev = next_net_device_rcu(state->dev);
518 if (!state->dev) {
519 state->idev = NULL;
520 break;
521 }
522 state->idev = __in6_dev_get(state->dev);
523 if (!state->idev)
524 continue;
525 read_lock_bh(&state->idev->lock);
526 im = state->idev->ac_list;
527 }
528 return im;
529}
530
531static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
532{
533 struct ifacaddr6 *im = ac6_get_first(seq);
534 if (im)
535 while (pos && (im = ac6_get_next(seq, im)) != NULL)
536 --pos;
537 return pos ? NULL : im;
538}
539
540static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
541 __acquires(RCU)
542{
543 rcu_read_lock();
544 return ac6_get_idx(seq, *pos);
545}
546
547static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
548{
549 struct ifacaddr6 *im = ac6_get_next(seq, v);
550
551 ++*pos;
552 return im;
553}
554
555static void ac6_seq_stop(struct seq_file *seq, void *v)
556 __releases(RCU)
557{
558 struct ac6_iter_state *state = ac6_seq_private(seq);
559
560 if (likely(state->idev != NULL)) {
561 read_unlock_bh(&state->idev->lock);
562 state->idev = NULL;
563 }
564 rcu_read_unlock();
565}
566
567static int ac6_seq_show(struct seq_file *seq, void *v)
568{
569 struct ifacaddr6 *im = (struct ifacaddr6 *)v;
570 struct ac6_iter_state *state = ac6_seq_private(seq);
571
572 seq_printf(seq, "%-4d %-15s %pi6 %5d\n",
573 state->dev->ifindex, state->dev->name,
574 &im->aca_addr, im->aca_users);
575 return 0;
576}
577
578static const struct seq_operations ac6_seq_ops = {
579 .start = ac6_seq_start,
580 .next = ac6_seq_next,
581 .stop = ac6_seq_stop,
582 .show = ac6_seq_show,
583};
584
585int __net_init ac6_proc_init(struct net *net)
586{
587 if (!proc_create_net("anycast6", 0444, net->proc_net, &ac6_seq_ops,
588 sizeof(struct ac6_iter_state)))
589 return -ENOMEM;
590
591 return 0;
592}
593
594void ac6_proc_exit(struct net *net)
595{
596 remove_proc_entry("anycast6", net->proc_net);
597}
598#endif
599
600/* Init / cleanup code
601 */
602int __init ipv6_anycast_init(void)
603{
604 int i;
605
606 for (i = 0; i < IN6_ADDR_HSIZE; i++)
607 INIT_HLIST_HEAD(&inet6_acaddr_lst[i]);
608 return 0;
609}
610
611void ipv6_anycast_cleanup(void)
612{
613 int i;
614
615 spin_lock(&acaddr_hash_lock);
616 for (i = 0; i < IN6_ADDR_HSIZE; i++)
617 WARN_ON(!hlist_empty(&inet6_acaddr_lst[i]));
618 spin_unlock(&acaddr_hash_lock);
619}
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}