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[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / ipv6 / anycast.c
blob0e5e943446f08c60690170c4e8af6fdc962a645e
1 /*
2 * Anycast support for IPv6
3 * Linux INET6 implementation
5 * Authors:
6 * David L Stevens (dlstevens@us.ibm.com)
8 * based heavily on net/ipv6/mcast.c
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.
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>
34 #include <net/net_namespace.h>
35 #include <net/sock.h>
36 #include <net/snmp.h>
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>
45 #include <net/checksum.h>
47 static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr);
49 /* Big ac list lock for all the sockets */
50 static DEFINE_RWLOCK(ipv6_sk_ac_lock);
54 * socket join an anycast group
57 int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr)
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;
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;
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);
80 rcu_read_lock();
81 if (ifindex == 0) {
82 struct rt6_info *rt;
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);
96 } else
97 dev = dev_get_by_index_rcu(net, ifindex);
99 if (dev == NULL) {
100 err = -ENODEV;
101 goto error;
104 idev = __in6_dev_get(dev);
105 if (!idev) {
106 if (ifindex)
107 err = -ENODEV;
108 else
109 err = -EADDRNOTAVAIL;
110 goto error;
112 /* reset ishost, now that we have a specific device */
113 ishost = !idev->cnf.forwarding;
115 pac->acl_ifindex = dev->ifindex;
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.
122 if (!ipv6_chk_prefix(addr, dev)) {
123 if (ishost)
124 err = -EADDRNOTAVAIL;
125 if (err)
126 goto error;
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;
138 error:
139 rcu_read_unlock();
140 if (pac)
141 sock_kfree_s(sk, pac, sizeof(*pac));
142 return err;
146 * socket leave an anycast group
148 int ipv6_sock_ac_drop(struct sock *sk, int ifindex, struct in6_addr *addr)
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);
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;
163 if (!pac) {
164 write_unlock_bh(&ipv6_sk_ac_lock);
165 return -ENOENT;
167 if (prev_pac)
168 prev_pac->acl_next = pac->acl_next;
169 else
170 np->ipv6_ac_list = pac->acl_next;
172 write_unlock_bh(&ipv6_sk_ac_lock);
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();
180 sock_kfree_s(sk, pac, sizeof(*pac));
181 return 0;
184 void ipv6_sock_ac_close(struct sock *sk)
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;
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);
197 prev_index = 0;
198 rcu_read_lock();
199 while (pac) {
200 struct ipv6_ac_socklist *next = pac->acl_next;
202 if (pac->acl_ifindex != prev_index) {
203 dev = dev_get_by_index_rcu(net, pac->acl_ifindex);
204 prev_index = pac->acl_ifindex;
206 if (dev)
207 ipv6_dev_ac_dec(dev, &pac->acl_addr);
208 sock_kfree_s(sk, pac, sizeof(*pac));
209 pac = next;
211 rcu_read_unlock();
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.
218 * It is OK, anycasts are not special comparing to delivery to unicasts.
221 int inet6_ac_check(struct sock *sk, struct in6_addr *addr, int ifindex)
223 struct ipv6_ac_socklist *pac;
224 struct ipv6_pinfo *np = inet6_sk(sk);
225 int found;
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;
236 read_unlock(&ipv6_sk_ac_lock);
238 return found;
241 #endif
243 static void aca_put(struct ifacaddr6 *ac)
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);
253 * device anycast group inc (add if not found)
255 int ipv6_dev_ac_inc(struct net_device *dev, struct in6_addr *addr)
257 struct ifacaddr6 *aca;
258 struct inet6_dev *idev;
259 struct rt6_info *rt;
260 int err;
262 idev = in6_dev_get(dev);
264 if (idev == NULL)
265 return -EINVAL;
267 write_lock_bh(&idev->lock);
268 if (idev->dead) {
269 err = -ENODEV;
270 goto out;
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;
282 * not found: create a new one.
285 aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
287 if (aca == NULL) {
288 err = -ENOMEM;
289 goto out;
292 rt = addrconf_dst_alloc(idev, addr, 1);
293 if (IS_ERR(rt)) {
294 kfree(aca);
295 err = PTR_ERR(rt);
296 goto out;
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);
308 aca->aca_next = idev->ac_list;
309 idev->ac_list = aca;
310 write_unlock_bh(&idev->lock);
312 ip6_ins_rt(rt);
314 addrconf_join_solict(dev, &aca->aca_addr);
316 aca_put(aca);
317 return 0;
318 out:
319 write_unlock_bh(&idev->lock);
320 in6_dev_put(idev);
321 return err;
325 * device anycast group decrement
327 int __ipv6_dev_ac_dec(struct inet6_dev *idev, struct in6_addr *addr)
329 struct ifacaddr6 *aca, *prev_aca;
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;
338 if (!aca) {
339 write_unlock_bh(&idev->lock);
340 return -ENOENT;
342 if (--aca->aca_users > 0) {
343 write_unlock_bh(&idev->lock);
344 return 0;
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);
353 dst_hold(&aca->aca_rt->dst);
354 ip6_del_rt(aca->aca_rt);
356 aca_put(aca);
357 return 0;
360 /* called with rcu_read_lock() */
361 static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr)
363 struct inet6_dev *idev = __in6_dev_get(dev);
365 if (idev == NULL)
366 return -ENODEV;
367 return __ipv6_dev_ac_dec(idev, addr);
371 * check if the interface has this anycast address
372 * called with rcu_read_lock()
374 static int ipv6_chk_acast_dev(struct net_device *dev, struct in6_addr *addr)
376 struct inet6_dev *idev;
377 struct ifacaddr6 *aca;
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;
388 return 0;
392 * check if given interface (or any, if dev==0) has this anycast address
394 int ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
395 struct in6_addr *addr)
397 int found = 0;
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;
408 rcu_read_unlock();
409 return found;
413 #ifdef CONFIG_PROC_FS
414 struct ac6_iter_state {
415 struct seq_net_private p;
416 struct net_device *dev;
417 struct inet6_dev *idev;
420 #define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
422 static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
424 struct ifacaddr6 *im = NULL;
425 struct ac6_iter_state *state = ac6_seq_private(seq);
426 struct net *net = seq_file_net(seq);
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;
440 read_unlock_bh(&idev->lock);
442 return im;
445 static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
447 struct ac6_iter_state *state = ac6_seq_private(seq);
449 im = im->aca_next;
450 while (!im) {
451 if (likely(state->idev != NULL))
452 read_unlock_bh(&state->idev->lock);
454 state->dev = next_net_device_rcu(state->dev);
455 if (!state->dev) {
456 state->idev = NULL;
457 break;
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;
465 return im;
468 static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
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;
477 static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
478 __acquires(RCU)
480 rcu_read_lock();
481 return ac6_get_idx(seq, *pos);
484 static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
486 struct ifacaddr6 *im = ac6_get_next(seq, v);
488 ++*pos;
489 return im;
492 static void ac6_seq_stop(struct seq_file *seq, void *v)
493 __releases(RCU)
495 struct ac6_iter_state *state = ac6_seq_private(seq);
497 if (likely(state->idev != NULL)) {
498 read_unlock_bh(&state->idev->lock);
499 state->idev = NULL;
501 rcu_read_unlock();
504 static int ac6_seq_show(struct seq_file *seq, void *v)
506 struct ifacaddr6 *im = (struct ifacaddr6 *)v;
507 struct ac6_iter_state *state = ac6_seq_private(seq);
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;
515 static 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,
522 static int ac6_seq_open(struct inode *inode, struct file *file)
524 return seq_open_net(inode, file, &ac6_seq_ops,
525 sizeof(struct ac6_iter_state));
528 static 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,
536 int __net_init ac6_proc_init(struct net *net)
538 if (!proc_net_fops_create(net, "anycast6", S_IRUGO, &ac6_seq_fops))
539 return -ENOMEM;
541 return 0;
544 void ac6_proc_exit(struct net *net)
546 proc_net_remove(net, "anycast6");
548 #endif