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v4.17
  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
v3.15
  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