[net-next-2.6.git] / net / ipv6 / anycast.c

/*
 *	Anycast support for IPv6
 *	Linux INET6 implementation
 *
 *	Authors:
 *	David L Stevens (dlstevens@us.ibm.com)
 *
 *	based heavily on net/ipv6/mcast.c
 *
 *	This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <linux/capability.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/random.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/route.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>

#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/snmp.h>

#include <net/ipv6.h>
#include <net/protocol.h>
#include <net/if_inet6.h>
#include <net/ndisc.h>
#include <net/addrconf.h>
#include <net/ip6_route.h>

#include <net/checksum.h>

static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr);

/* Big ac list lock for all the sockets */
static DEFINE_RWLOCK(ipv6_sk_ac_lock);


/*
 *	socket join an anycast group
 */

int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct net_device *dev = NULL;
	struct inet6_dev *idev;
	struct ipv6_ac_socklist *pac;
	struct net *net = sock_net(sk);
	int	ishost = !net->ipv6.devconf_all->forwarding;
	int	err = 0;

	if (!capable(CAP_NET_ADMIN))
		return -EPERM;
	if (ipv6_addr_is_multicast(addr))
		return -EINVAL;
	if (ipv6_chk_addr(net, addr, NULL, 0))
		return -EINVAL;

	pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
	if (pac == NULL)
		return -ENOMEM;
	pac->acl_next = NULL;
	ipv6_addr_copy(&pac->acl_addr, addr);

	if (ifindex == 0) {
		struct rt6_info *rt;

		rt = rt6_lookup(net, addr, NULL, 0, 0);
		if (rt) {
			dev = rt->rt6i_dev;
			dev_hold(dev);
			dst_release(&rt->u.dst);
		} else if (ishost) {
			err = -EADDRNOTAVAIL;
			goto out_free_pac;
		} else {
			/* router, no matching interface: just pick one */

			dev = dev_get_by_flags(net, IFF_UP, IFF_UP|IFF_LOOPBACK);
		}
	} else
		dev = dev_get_by_index(net, ifindex);

	if (dev == NULL) {
		err = -ENODEV;
		goto out_free_pac;
	}

	idev = in6_dev_get(dev);
	if (!idev) {
		if (ifindex)
			err = -ENODEV;
		else
			err = -EADDRNOTAVAIL;
		goto out_dev_put;
	}
	/* reset ishost, now that we have a specific device */
	ishost = !idev->cnf.forwarding;
	in6_dev_put(idev);

	pac->acl_ifindex = dev->ifindex;

	/* XXX
	 * For hosts, allow link-local or matching prefix anycasts.
	 * This obviates the need for propagating anycast routes while
	 * still allowing some non-router anycast participation.
	 */
	if (!ipv6_chk_prefix(addr, dev)) {
		if (ishost)
			err = -EADDRNOTAVAIL;
		if (err)
			goto out_dev_put;
	}

	err = ipv6_dev_ac_inc(dev, addr);
	if (err)
		goto out_dev_put;

	write_lock_bh(&ipv6_sk_ac_lock);
	pac->acl_next = np->ipv6_ac_list;
	np->ipv6_ac_list = pac;
	write_unlock_bh(&ipv6_sk_ac_lock);

	dev_put(dev);

	return 0;

out_dev_put:
	dev_put(dev);
out_free_pac:
	sock_kfree_s(sk, pac, sizeof(*pac));
	return err;
}

/*
 *	socket leave an anycast group
 */
int ipv6_sock_ac_drop(struct sock *sk, int ifindex, struct in6_addr *addr)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct net_device *dev;
	struct ipv6_ac_socklist *pac, *prev_pac;
	struct net *net = sock_net(sk);

	write_lock_bh(&ipv6_sk_ac_lock);
	prev_pac = NULL;
	for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
		if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
		     ipv6_addr_equal(&pac->acl_addr, addr))
			break;
		prev_pac = pac;
	}
	if (!pac) {
		write_unlock_bh(&ipv6_sk_ac_lock);
		return -ENOENT;
	}
	if (prev_pac)
		prev_pac->acl_next = pac->acl_next;
	else
		np->ipv6_ac_list = pac->acl_next;

	write_unlock_bh(&ipv6_sk_ac_lock);

	dev = dev_get_by_index(net, pac->acl_ifindex);
	if (dev) {
		ipv6_dev_ac_dec(dev, &pac->acl_addr);
		dev_put(dev);
	}
	sock_kfree_s(sk, pac, sizeof(*pac));
	return 0;
}

void ipv6_sock_ac_close(struct sock *sk)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct net_device *dev = NULL;
	struct ipv6_ac_socklist *pac;
	struct net *net = sock_net(sk);
	int	prev_index;

	write_lock_bh(&ipv6_sk_ac_lock);
	pac = np->ipv6_ac_list;
	np->ipv6_ac_list = NULL;
	write_unlock_bh(&ipv6_sk_ac_lock);

	prev_index = 0;
	while (pac) {
		struct ipv6_ac_socklist *next = pac->acl_next;

		if (pac->acl_ifindex != prev_index) {
			if (dev)
				dev_put(dev);
			dev = dev_get_by_index(net, pac->acl_ifindex);
			prev_index = pac->acl_ifindex;
		}
		if (dev)
			ipv6_dev_ac_dec(dev, &pac->acl_addr);
		sock_kfree_s(sk, pac, sizeof(*pac));
		pac = next;
	}
	if (dev)
		dev_put(dev);
}

#if 0
/* The function is not used, which is funny. Apparently, author
 * supposed to use it to filter out datagrams inside udp/raw but forgot.
 *
 * It is OK, anycasts are not special comparing to delivery to unicasts.
 */

int inet6_ac_check(struct sock *sk, struct in6_addr *addr, int ifindex)
{
	struct ipv6_ac_socklist *pac;
	struct ipv6_pinfo *np = inet6_sk(sk);
	int	found;

	found = 0;
	read_lock(&ipv6_sk_ac_lock);
	for (pac=np->ipv6_ac_list; pac; pac=pac->acl_next) {
		if (ifindex && pac->acl_ifindex != ifindex)
			continue;
		found = ipv6_addr_equal(&pac->acl_addr, addr);
		if (found)
			break;
	}
	read_unlock(&ipv6_sk_ac_lock);

	return found;
}

#endif

static void aca_put(struct ifacaddr6 *ac)
{
	if (atomic_dec_and_test(&ac->aca_refcnt)) {
		in6_dev_put(ac->aca_idev);
		dst_release(&ac->aca_rt->u.dst);
		kfree(ac);
	}
}

/*
 *	device anycast group inc (add if not found)
 */
int ipv6_dev_ac_inc(struct net_device *dev, struct in6_addr *addr)
{
	struct ifacaddr6 *aca;
	struct inet6_dev *idev;
	struct rt6_info *rt;
	int err;

	idev = in6_dev_get(dev);

	if (idev == NULL)
		return -EINVAL;

	write_lock_bh(&idev->lock);
	if (idev->dead) {
		err = -ENODEV;
		goto out;
	}

	for (aca = idev->ac_list; aca; aca = aca->aca_next) {
		if (ipv6_addr_equal(&aca->aca_addr, addr)) {
			aca->aca_users++;
			err = 0;
			goto out;
		}
	}

	/*
	 *	not found: create a new one.
	 */

	aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);

	if (aca == NULL) {
		err = -ENOMEM;
		goto out;
	}

	rt = addrconf_dst_alloc(idev, addr, 1);
	if (IS_ERR(rt)) {
		kfree(aca);
		err = PTR_ERR(rt);
		goto out;
	}

	ipv6_addr_copy(&aca->aca_addr, addr);
	aca->aca_idev = idev;
	aca->aca_rt = rt;
	aca->aca_users = 1;
	/* aca_tstamp should be updated upon changes */
	aca->aca_cstamp = aca->aca_tstamp = jiffies;
	atomic_set(&aca->aca_refcnt, 2);
	spin_lock_init(&aca->aca_lock);

	aca->aca_next = idev->ac_list;
	idev->ac_list = aca;
	write_unlock_bh(&idev->lock);

	ip6_ins_rt(rt);

	addrconf_join_solict(dev, &aca->aca_addr);

	aca_put(aca);
	return 0;
out:
	write_unlock_bh(&idev->lock);
	in6_dev_put(idev);
	return err;
}

/*
 *	device anycast group decrement
 */
int __ipv6_dev_ac_dec(struct inet6_dev *idev, struct in6_addr *addr)
{
	struct ifacaddr6 *aca, *prev_aca;

	write_lock_bh(&idev->lock);
	prev_aca = NULL;
	for (aca = idev->ac_list; aca; aca = aca->aca_next) {
		if (ipv6_addr_equal(&aca->aca_addr, addr))
			break;
		prev_aca = aca;
	}
	if (!aca) {
		write_unlock_bh(&idev->lock);
		return -ENOENT;
	}
	if (--aca->aca_users > 0) {
		write_unlock_bh(&idev->lock);
		return 0;
	}
	if (prev_aca)
		prev_aca->aca_next = aca->aca_next;
	else
		idev->ac_list = aca->aca_next;
	write_unlock_bh(&idev->lock);
	addrconf_leave_solict(idev, &aca->aca_addr);

	dst_hold(&aca->aca_rt->u.dst);
	ip6_del_rt(aca->aca_rt);

	aca_put(aca);
	return 0;
}

static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr)
{
	int ret;
	struct inet6_dev *idev = in6_dev_get(dev);
	if (idev == NULL)
		return -ENODEV;
	ret = __ipv6_dev_ac_dec(idev, addr);
	in6_dev_put(idev);
	return ret;
}

/*
 *	check if the interface has this anycast address
 */
static int ipv6_chk_acast_dev(struct net_device *dev, struct in6_addr *addr)
{
	struct inet6_dev *idev;
	struct ifacaddr6 *aca;

	idev = in6_dev_get(dev);
	if (idev) {
		read_lock_bh(&idev->lock);
		for (aca = idev->ac_list; aca; aca = aca->aca_next)
			if (ipv6_addr_equal(&aca->aca_addr, addr))
				break;
		read_unlock_bh(&idev->lock);
		in6_dev_put(idev);
		return aca != NULL;
	}
	return 0;
}

/*
 *	check if given interface (or any, if dev==0) has this anycast address
 */
int ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
			struct in6_addr *addr)
{
	int found = 0;

	if (dev)
		return ipv6_chk_acast_dev(dev, addr);
	read_lock(&dev_base_lock);
	for_each_netdev(net, dev)
		if (ipv6_chk_acast_dev(dev, addr)) {
			found = 1;
			break;
		}
	read_unlock(&dev_base_lock);
	return found;
}


#ifdef CONFIG_PROC_FS
struct ac6_iter_state {
	struct seq_net_private p;
	struct net_device *dev;
	struct inet6_dev *idev;
};

#define ac6_seq_private(seq)	((struct ac6_iter_state *)(seq)->private)

static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
{
	struct ifacaddr6 *im = NULL;
	struct ac6_iter_state *state = ac6_seq_private(seq);
	struct net *net = seq_file_net(seq);

	state->idev = NULL;
	for_each_netdev(net, state->dev) {
		struct inet6_dev *idev;
		idev = in6_dev_get(state->dev);
		if (!idev)
			continue;
		read_lock_bh(&idev->lock);
		im = idev->ac_list;
		if (im) {
			state->idev = idev;
			break;
		}
		read_unlock_bh(&idev->lock);
		in6_dev_put(idev);
	}
	return im;
}

static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
{
	struct ac6_iter_state *state = ac6_seq_private(seq);

	im = im->aca_next;
	while (!im) {
		if (likely(state->idev != NULL)) {
			read_unlock_bh(&state->idev->lock);
			in6_dev_put(state->idev);
		}
		state->dev = next_net_device(state->dev);
		if (!state->dev) {
			state->idev = NULL;
			break;
		}
		state->idev = in6_dev_get(state->dev);
		if (!state->idev)
			continue;
		read_lock_bh(&state->idev->lock);
		im = state->idev->ac_list;
	}
	return im;
}

static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
{
	struct ifacaddr6 *im = ac6_get_first(seq);
	if (im)
		while (pos && (im = ac6_get_next(seq, im)) != NULL)
			--pos;
	return pos ? NULL : im;
}

static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
	__acquires(dev_base_lock)
{
	read_lock(&dev_base_lock);
	return ac6_get_idx(seq, *pos);
}

static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct ifacaddr6 *im;
	im = ac6_get_next(seq, v);
	++*pos;
	return im;
}

static void ac6_seq_stop(struct seq_file *seq, void *v)
	__releases(dev_base_lock)
{
	struct ac6_iter_state *state = ac6_seq_private(seq);
	if (likely(state->idev != NULL)) {
		read_unlock_bh(&state->idev->lock);
		in6_dev_put(state->idev);
	}
	read_unlock(&dev_base_lock);
}

static int ac6_seq_show(struct seq_file *seq, void *v)
{
	struct ifacaddr6 *im = (struct ifacaddr6 *)v;
	struct ac6_iter_state *state = ac6_seq_private(seq);

	seq_printf(seq, "%-4d %-15s %pi6 %5d\n",
		   state->dev->ifindex, state->dev->name,
		   &im->aca_addr, im->aca_users);
	return 0;
}

static const struct seq_operations ac6_seq_ops = {
	.start	=	ac6_seq_start,
	.next	=	ac6_seq_next,
	.stop	=	ac6_seq_stop,
	.show	=	ac6_seq_show,
};

static int ac6_seq_open(struct inode *inode, struct file *file)
{
	return seq_open_net(inode, file, &ac6_seq_ops,
			    sizeof(struct ac6_iter_state));
}

static const struct file_operations ac6_seq_fops = {
	.owner		=	THIS_MODULE,
	.open		=	ac6_seq_open,
	.read		=	seq_read,
	.llseek		=	seq_lseek,
	.release	=	seq_release_net,
};

int ac6_proc_init(struct net *net)
{
	if (!proc_net_fops_create(net, "anycast6", S_IRUGO, &ac6_seq_fops))
		return -ENOMEM;

	return 0;
}

void ac6_proc_exit(struct net *net)
{
	proc_net_remove(net, "anycast6");
}
#endif
Commit	Line	Data
1da177e4 LT	1	/*
1da177e4 LT	2	* Anycast support for IPv6
1ab1457c	3	* Linux INET6 implementation
1da177e4 LT	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
4fc268d2	16	#include <linux/capability.h>
1da177e4 LT	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>
1da177e4 LT	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
457c4cbc	33	#include <net/net_namespace.h>
1da177e4 LT	34	#include <net/sock.h>
	35	#include <net/snmp.h>
	36
	37	#include <net/ipv6.h>
	38	#include <net/protocol.h>
	39	#include <net/if_inet6.h>
	40	#include <net/ndisc.h>
	41	#include <net/addrconf.h>
	42	#include <net/ip6_route.h>
	43
	44	#include <net/checksum.h>
	45
	46	static int ipv6_dev_ac_dec(struct net_device dev, struct in6_addr addr);
	47
	48	/* Big ac list lock for all the sockets */
	49	static DEFINE_RWLOCK(ipv6_sk_ac_lock);
	50
1da177e4 LT	51
	52	/*
	53	* socket join an anycast group
	54	*/
	55
	56	int ipv6_sock_ac_join(struct sock sk, int ifindex, struct in6_addr addr)
	57	{
	58	struct ipv6_pinfo *np = inet6_sk(sk);
	59	struct net_device *dev = NULL;
	60	struct inet6_dev *idev;
	61	struct ipv6_ac_socklist *pac;
6ab57e7e	62	struct net *net = sock_net(sk);
53b7997f	63	int ishost = !net->ipv6.devconf_all->forwarding;
1da177e4 LT	64	int err = 0;
	65
	66	if (!capable(CAP_NET_ADMIN))
	67	return -EPERM;
	68	if (ipv6_addr_is_multicast(addr))
	69	return -EINVAL;
6ab57e7e	70	if (ipv6_chk_addr(net, addr, NULL, 0))
1da177e4 LT	71	return -EINVAL;
	72
	73	pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
	74	if (pac == NULL)
	75	return -ENOMEM;
	76	pac->acl_next = NULL;
	77	ipv6_addr_copy(&pac->acl_addr, addr);
	78
	79	if (ifindex == 0) {
	80	struct rt6_info *rt;
	81
6ab57e7e	82	rt = rt6_lookup(net, addr, NULL, 0, 0);
1da177e4 LT	83	if (rt) {
	84	dev = rt->rt6i_dev;
	85	dev_hold(dev);
	86	dst_release(&rt->u.dst);
	87	} else if (ishost) {
	88	err = -EADDRNOTAVAIL;
	89	goto out_free_pac;
	90	} else {
	91	/* router, no matching interface: just pick one */
	92
6ab57e7e	93	dev = dev_get_by_flags(net, IFF_UP, IFF_UP\|IFF_LOOPBACK);
1da177e4 LT	94	}
1da177e4 LT	95	} else
6ab57e7e	96	dev = dev_get_by_index(net, ifindex);
1da177e4 LT	97
	98	if (dev == NULL) {
	99	err = -ENODEV;
	100	goto out_free_pac;
	101	}
	102
	103	idev = in6_dev_get(dev);
	104	if (!idev) {
	105	if (ifindex)
	106	err = -ENODEV;
	107	else
	108	err = -EADDRNOTAVAIL;
	109	goto out_dev_put;
	110	}
	111	/* reset ishost, now that we have a specific device */
	112	ishost = !idev->cnf.forwarding;
	113	in6_dev_put(idev);
	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	*/
52eeeb84	122	if (!ipv6_chk_prefix(addr, dev)) {
1da177e4 LT	123	if (ishost)
	124	err = -EADDRNOTAVAIL;
	125	if (err)
	126	goto out_dev_put;
	127	}
	128
	129	err = ipv6_dev_ac_inc(dev, addr);
	130	if (err)
	131	goto out_dev_put;
	132
	133	write_lock_bh(&ipv6_sk_ac_lock);
	134	pac->acl_next = np->ipv6_ac_list;
	135	np->ipv6_ac_list = pac;
	136	write_unlock_bh(&ipv6_sk_ac_lock);
	137
	138	dev_put(dev);
	139
	140	return 0;
	141
	142	out_dev_put:
	143	dev_put(dev);
	144	out_free_pac:
	145	sock_kfree_s(sk, pac, sizeof(*pac));
	146	return err;
	147	}
	148
	149	/*
	150	* socket leave an anycast group
	151	*/
	152	int ipv6_sock_ac_drop(struct sock sk, int ifindex, struct in6_addr addr)
	153	{
	154	struct ipv6_pinfo *np = inet6_sk(sk);
	155	struct net_device *dev;
	156	struct ipv6_ac_socklist pac, prev_pac;
6ab57e7e	157	struct net *net = sock_net(sk);
1da177e4 LT	158
	159	write_lock_bh(&ipv6_sk_ac_lock);
	160	prev_pac = NULL;
	161	for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
	162	if ((ifindex == 0 \|\| pac->acl_ifindex == ifindex) &&
	163	ipv6_addr_equal(&pac->acl_addr, addr))
	164	break;
	165	prev_pac = pac;
	166	}
	167	if (!pac) {
	168	write_unlock_bh(&ipv6_sk_ac_lock);
	169	return -ENOENT;
	170	}
	171	if (prev_pac)
	172	prev_pac->acl_next = pac->acl_next;
	173	else
	174	np->ipv6_ac_list = pac->acl_next;
	175
	176	write_unlock_bh(&ipv6_sk_ac_lock);
	177
6ab57e7e	178	dev = dev_get_by_index(net, pac->acl_ifindex);
1da177e4 LT	179	if (dev) {
	180	ipv6_dev_ac_dec(dev, &pac->acl_addr);
	181	dev_put(dev);
	182	}
	183	sock_kfree_s(sk, pac, sizeof(*pac));
	184	return 0;
	185	}
	186
	187	void 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;
6ab57e7e	192	struct net *net = sock_net(sk);
1da177e4 LT	193	int prev_index;
	194
	195	write_lock_bh(&ipv6_sk_ac_lock);
	196	pac = np->ipv6_ac_list;
	197	np->ipv6_ac_list = NULL;
	198	write_unlock_bh(&ipv6_sk_ac_lock);
	199
	200	prev_index = 0;
	201	while (pac) {
	202	struct ipv6_ac_socklist *next = pac->acl_next;
	203
	204	if (pac->acl_ifindex != prev_index) {
	205	if (dev)
	206	dev_put(dev);
6ab57e7e	207	dev = dev_get_by_index(net, pac->acl_ifindex);
1da177e4 LT	208	prev_index = pac->acl_ifindex;
	209	}
	210	if (dev)
	211	ipv6_dev_ac_dec(dev, &pac->acl_addr);
	212	sock_kfree_s(sk, pac, sizeof(*pac));
	213	pac = next;
	214	}
	215	if (dev)
	216	dev_put(dev);
	217	}
	218
	219	#if 0
	220	/* The function is not used, which is funny. Apparently, author
	221	* supposed to use it to filter out datagrams inside udp/raw but forgot.
	222	*
	223	* It is OK, anycasts are not special comparing to delivery to unicasts.
	224	*/
	225
	226	int inet6_ac_check(struct sock sk, struct in6_addr addr, int ifindex)
	227	{
	228	struct ipv6_ac_socklist *pac;
	229	struct ipv6_pinfo *np = inet6_sk(sk);
	230	int found;
	231
	232	found = 0;
	233	read_lock(&ipv6_sk_ac_lock);
	234	for (pac=np->ipv6_ac_list; pac; pac=pac->acl_next) {
	235	if (ifindex && pac->acl_ifindex != ifindex)
	236	continue;
	237	found = ipv6_addr_equal(&pac->acl_addr, addr);
	238	if (found)
	239	break;
	240	}
	241	read_unlock(&ipv6_sk_ac_lock);
	242
	243	return found;
	244	}
	245
	246	#endif
	247
	248	static void aca_put(struct ifacaddr6 *ac)
	249	{
	250	if (atomic_dec_and_test(&ac->aca_refcnt)) {
	251	in6_dev_put(ac->aca_idev);
	252	dst_release(&ac->aca_rt->u.dst);
	253	kfree(ac);
	254	}
	255	}
	256
	257	/*
	258	* device anycast group inc (add if not found)
	259	*/
	260	int ipv6_dev_ac_inc(struct net_device dev, struct in6_addr addr)
	261	{
	262	struct ifacaddr6 *aca;
	263	struct inet6_dev *idev;
	264	struct rt6_info *rt;
	265	int err;
	266
	267	idev = in6_dev_get(dev);
	268
	269	if (idev == NULL)
	270	return -EINVAL;
	271
272	write_lock_bh(&idev->lock);
273	if (idev->dead) {
274	err = -ENODEV;
275	goto out;
276	}
277
278	for (aca = idev->ac_list; aca; aca = aca->aca_next) {
279	if (ipv6_addr_equal(&aca->aca_addr, addr)) {
280	aca->aca_users++;
281	err = 0;
282	goto out;
283	}
284	}
285
286	/*
287	* not found: create a new one.
288	*/
289
0c600eda	290	aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
1da177e4 LT	291
	292	if (aca == NULL) {
	293	err = -ENOMEM;
	294	goto out;
	295	}
	296
	297	rt = addrconf_dst_alloc(idev, addr, 1);
	298	if (IS_ERR(rt)) {
	299	kfree(aca);
	300	err = PTR_ERR(rt);
	301	goto out;
	302	}
	303
1da177e4 LT	304	ipv6_addr_copy(&aca->aca_addr, addr);
	305	aca->aca_idev = idev;
	306	aca->aca_rt = rt;
	307	aca->aca_users = 1;
	308	/* aca_tstamp should be updated upon changes */
	309	aca->aca_cstamp = aca->aca_tstamp = jiffies;
	310	atomic_set(&aca->aca_refcnt, 2);
	311	spin_lock_init(&aca->aca_lock);
	312
	313	aca->aca_next = idev->ac_list;
	314	idev->ac_list = aca;
	315	write_unlock_bh(&idev->lock);
	316
84f59370	317	ip6_ins_rt(rt);
1da177e4 LT	318
	319	addrconf_join_solict(dev, &aca->aca_addr);
	320
	321	aca_put(aca);
	322	return 0;
	323	out:
	324	write_unlock_bh(&idev->lock);
	325	in6_dev_put(idev);
	326	return err;
	327	}
	328
	329	/*
	330	* device anycast group decrement
	331	*/
	332	int __ipv6_dev_ac_dec(struct inet6_dev idev, struct in6_addr addr)
	333	{
	334	struct ifacaddr6 aca, prev_aca;
	335
	336	write_lock_bh(&idev->lock);
	337	prev_aca = NULL;
	338	for (aca = idev->ac_list; aca; aca = aca->aca_next) {
	339	if (ipv6_addr_equal(&aca->aca_addr, addr))
	340	break;
	341	prev_aca = aca;
	342	}
	343	if (!aca) {
	344	write_unlock_bh(&idev->lock);
	345	return -ENOENT;
	346	}
	347	if (--aca->aca_users > 0) {
	348	write_unlock_bh(&idev->lock);
	349	return 0;
	350	}
	351	if (prev_aca)
	352	prev_aca->aca_next = aca->aca_next;
	353	else
	354	idev->ac_list = aca->aca_next;
	355	write_unlock_bh(&idev->lock);
	356	addrconf_leave_solict(idev, &aca->aca_addr);
	357
	358	dst_hold(&aca->aca_rt->u.dst);
84f59370	359	ip6_del_rt(aca->aca_rt);
1da177e4 LT	360
	361	aca_put(aca);
	362	return 0;
	363	}
	364
	365	static int ipv6_dev_ac_dec(struct net_device dev, struct in6_addr addr)
	366	{
	367	int ret;
	368	struct inet6_dev *idev = in6_dev_get(dev);
	369	if (idev == NULL)
	370	return -ENODEV;
	371	ret = __ipv6_dev_ac_dec(idev, addr);
	372	in6_dev_put(idev);
	373	return ret;
	374	}
1ab1457c	375
1da177e4 LT	376	/*
	377	* check if the interface has this anycast address
	378	*/
	379	static int ipv6_chk_acast_dev(struct net_device dev, struct in6_addr addr)
	380	{
	381	struct inet6_dev *idev;
	382	struct ifacaddr6 *aca;
	383
	384	idev = in6_dev_get(dev);
	385	if (idev) {
	386	read_lock_bh(&idev->lock);
	387	for (aca = idev->ac_list; aca; aca = aca->aca_next)
	388	if (ipv6_addr_equal(&aca->aca_addr, addr))
	389	break;
	390	read_unlock_bh(&idev->lock);
	391	in6_dev_put(idev);
cfcabdcc	392	return aca != NULL;
1da177e4 LT	393	}
	394	return 0;
	395	}
	396
	397	/*
	398	* check if given interface (or any, if dev==0) has this anycast address
	399	*/
6ab57e7e DL	400	int ipv6_chk_acast_addr(struct net net, struct net_device dev,
6ab57e7e DL	401	struct in6_addr *addr)
1da177e4	402	{
7562f876 PE	403	int found = 0;
7562f876 PE	404
1da177e4 LT	405	if (dev)
	406	return ipv6_chk_acast_dev(dev, addr);
	407	read_lock(&dev_base_lock);
6ab57e7e	408	for_each_netdev(net, dev)
7562f876 PE	409	if (ipv6_chk_acast_dev(dev, addr)) {
7562f876 PE	410	found = 1;
1da177e4	411	break;
7562f876	412	}
1da177e4	413	read_unlock(&dev_base_lock);
7562f876	414	return found;
1da177e4 LT	415	}
	416
	417
	418	#ifdef CONFIG_PROC_FS
	419	struct ac6_iter_state {
6ab57e7e	420	struct seq_net_private p;
1da177e4 LT	421	struct net_device *dev;
	422	struct inet6_dev *idev;
	423	};
	424
	425	#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
	426
	427	static inline struct ifacaddr6 ac6_get_first(struct seq_file seq)
	428	{
	429	struct ifacaddr6 *im = NULL;
	430	struct ac6_iter_state *state = ac6_seq_private(seq);
6ab57e7e	431	struct net *net = seq_file_net(seq);
1da177e4	432
7562f876	433	state->idev = NULL;
6ab57e7e	434	for_each_netdev(net, state->dev) {
1da177e4 LT	435	struct inet6_dev *idev;
	436	idev = in6_dev_get(state->dev);
	437	if (!idev)
	438	continue;
	439	read_lock_bh(&idev->lock);
	440	im = idev->ac_list;
	441	if (im) {
	442	state->idev = idev;
	443	break;
	444	}
	445	read_unlock_bh(&idev->lock);
aa6e4a96	446	in6_dev_put(idev);
1da177e4 LT	447	}
	448	return im;
	449	}
	450
	451	static struct ifacaddr6 ac6_get_next(struct seq_file seq, struct ifacaddr6 *im)
	452	{
	453	struct ac6_iter_state *state = ac6_seq_private(seq);
	454
	455	im = im->aca_next;
	456	while (!im) {
	457	if (likely(state->idev != NULL)) {
	458	read_unlock_bh(&state->idev->lock);
	459	in6_dev_put(state->idev);
	460	}
7562f876	461	state->dev = next_net_device(state->dev);
1da177e4 LT	462	if (!state->dev) {
	463	state->idev = NULL;
	464	break;
	465	}
	466	state->idev = in6_dev_get(state->dev);
	467	if (!state->idev)
	468	continue;
	469	read_lock_bh(&state->idev->lock);
	470	im = state->idev->ac_list;
	471	}
	472	return im;
	473	}
	474
	475	static struct ifacaddr6 ac6_get_idx(struct seq_file seq, loff_t pos)
	476	{
	477	struct ifacaddr6 *im = ac6_get_first(seq);
	478	if (im)
	479	while (pos && (im = ac6_get_next(seq, im)) != NULL)
	480	--pos;
	481	return pos ? NULL : im;
	482	}
	483
	484	static void ac6_seq_start(struct seq_file seq, loff_t *pos)
9a429c49	485	__acquires(dev_base_lock)
1da177e4 LT	486	{
	487	read_lock(&dev_base_lock);
	488	return ac6_get_idx(seq, *pos);
	489	}
	490
	491	static void ac6_seq_next(struct seq_file seq, void v, loff_t pos)
	492	{
	493	struct ifacaddr6 *im;
	494	im = ac6_get_next(seq, v);
	495	++*pos;
	496	return im;
	497	}
	498
	499	static void ac6_seq_stop(struct seq_file seq, void v)
9a429c49	500	__releases(dev_base_lock)
1da177e4 LT	501	{
	502	struct ac6_iter_state *state = ac6_seq_private(seq);
	503	if (likely(state->idev != NULL)) {
	504	read_unlock_bh(&state->idev->lock);
	505	in6_dev_put(state->idev);
	506	}
	507	read_unlock(&dev_base_lock);
	508	}
	509
	510	static int ac6_seq_show(struct seq_file seq, void v)
	511	{
	512	struct ifacaddr6 im = (struct ifacaddr6 )v;
	513	struct ac6_iter_state *state = ac6_seq_private(seq);
	514
4b7a4274	515	seq_printf(seq, "%-4d %-15s %pi6 %5d\n",
1da177e4	516	state->dev->ifindex, state->dev->name,
b071195d	517	&im->aca_addr, im->aca_users);
1da177e4 LT	518	return 0;
	519	}
	520
56b3d975	521	static const struct seq_operations ac6_seq_ops = {
1da177e4 LT	522	.start = ac6_seq_start,
	523	.next = ac6_seq_next,
	524	.stop = ac6_seq_stop,
	525	.show = ac6_seq_show,
	526	};
	527
	528	static int ac6_seq_open(struct inode inode, struct file file)
	529	{
6ab57e7e DL	530	return seq_open_net(inode, file, &ac6_seq_ops,
6ab57e7e DL	531	sizeof(struct ac6_iter_state));
1da177e4 LT	532	}
1da177e4 LT	533
9a32144e	534	static const struct file_operations ac6_seq_fops = {
1da177e4 LT	535	.owner = THIS_MODULE,
	536	.open = ac6_seq_open,
	537	.read = seq_read,
	538	.llseek = seq_lseek,
6ab57e7e	539	.release = seq_release_net,
1da177e4 LT	540	};
1da177e4 LT	541
6ab57e7e	542	int ac6_proc_init(struct net *net)
1da177e4	543	{
6ab57e7e	544	if (!proc_net_fops_create(net, "anycast6", S_IRUGO, &ac6_seq_fops))
1da177e4 LT	545	return -ENOMEM;
	546
	547	return 0;
	548	}
	549
6ab57e7e	550	void ac6_proc_exit(struct net *net)
1da177e4	551	{
6ab57e7e	552	proc_net_remove(net, "anycast6");
1da177e4 LT	553	}
	554	#endif
	555