[GitHub/mt8127/android_kernel_alcatel_ttab.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);

static int
ip6_onlink(struct in6_addr *addr, struct net_device *dev)
{
	struct inet6_dev	*idev;
	struct inet6_ifaddr	*ifa;
	int	onlink;

	onlink = 0;
	rcu_read_lock();
	idev = __in6_dev_get(dev);
	if (idev) {
		read_lock_bh(&idev->lock);
		for (ifa=idev->addr_list; ifa; ifa=ifa->if_next) {
			onlink = ipv6_prefix_equal(addr, &ifa->addr,
						   ifa->prefix_len);
			if (onlink)
				break;
		}
		read_unlock_bh(&idev->lock);
	}
	rcu_read_unlock();
	return onlink;
}

/*
 *	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 = !ipv6_devconf.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 (!ip6_onlink(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);

	dst_hold(&rt->u.dst);
	if (ip6_ins_rt(rt))
		dst_release(&rt->u.dst);

	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);
	if (ip6_del_rt(aca->aca_rt))
		dst_free(&aca->aca_rt->u.dst);
	else
		dst_release(&aca->aca_rt->u.dst);

	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 " NIP6_SEQFMT " %5d\n",
		   state->dev->ifindex, state->dev->name,
		   NIP6(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
	51	static int
	52	ip6_onlink(struct in6_addr addr, struct net_device dev)
	53	{
	54	struct inet6_dev *idev;
	55	struct inet6_ifaddr *ifa;
	56	int onlink;
	57
	58	onlink = 0;
8814c4b5	59	rcu_read_lock();
1da177e4 LT	60	idev = __in6_dev_get(dev);
	61	if (idev) {
	62	read_lock_bh(&idev->lock);
	63	for (ifa=idev->addr_list; ifa; ifa=ifa->if_next) {
	64	onlink = ipv6_prefix_equal(addr, &ifa->addr,
	65	ifa->prefix_len);
	66	if (onlink)
	67	break;
	68	}
	69	read_unlock_bh(&idev->lock);
	70	}
8814c4b5	71	rcu_read_unlock();
1da177e4 LT	72	return onlink;
	73	}
	74
	75	/*
	76	* socket join an anycast group
	77	*/
	78
	79	int ipv6_sock_ac_join(struct sock sk, int ifindex, struct in6_addr addr)
	80	{
	81	struct ipv6_pinfo *np = inet6_sk(sk);
	82	struct net_device *dev = NULL;
	83	struct inet6_dev *idev;
	84	struct ipv6_ac_socklist *pac;
6ab57e7e	85	struct net *net = sock_net(sk);
1da177e4 LT	86	int ishost = !ipv6_devconf.forwarding;
	87	int err = 0;
	88
	89	if (!capable(CAP_NET_ADMIN))
	90	return -EPERM;
	91	if (ipv6_addr_is_multicast(addr))
	92	return -EINVAL;
6ab57e7e	93	if (ipv6_chk_addr(net, addr, NULL, 0))
1da177e4 LT	94	return -EINVAL;
	95
	96	pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
	97	if (pac == NULL)
	98	return -ENOMEM;
	99	pac->acl_next = NULL;
	100	ipv6_addr_copy(&pac->acl_addr, addr);
	101
	102	if (ifindex == 0) {
	103	struct rt6_info *rt;
	104
6ab57e7e	105	rt = rt6_lookup(net, addr, NULL, 0, 0);
1da177e4 LT	106	if (rt) {
	107	dev = rt->rt6i_dev;
	108	dev_hold(dev);
	109	dst_release(&rt->u.dst);
	110	} else if (ishost) {
	111	err = -EADDRNOTAVAIL;
	112	goto out_free_pac;
	113	} else {
	114	/* router, no matching interface: just pick one */
	115
6ab57e7e	116	dev = dev_get_by_flags(net, IFF_UP, IFF_UP\|IFF_LOOPBACK);
1da177e4 LT	117	}
1da177e4 LT	118	} else
6ab57e7e	119	dev = dev_get_by_index(net, ifindex);
1da177e4 LT	120
	121	if (dev == NULL) {
	122	err = -ENODEV;
	123	goto out_free_pac;
	124	}
	125
	126	idev = in6_dev_get(dev);
	127	if (!idev) {
	128	if (ifindex)
	129	err = -ENODEV;
	130	else
	131	err = -EADDRNOTAVAIL;
	132	goto out_dev_put;
	133	}
	134	/* reset ishost, now that we have a specific device */
	135	ishost = !idev->cnf.forwarding;
	136	in6_dev_put(idev);
	137
	138	pac->acl_ifindex = dev->ifindex;
	139
	140	/* XXX
	141	* For hosts, allow link-local or matching prefix anycasts.
	142	* This obviates the need for propagating anycast routes while
	143	* still allowing some non-router anycast participation.
	144	*/
	145	if (!ip6_onlink(addr, dev)) {
	146	if (ishost)
	147	err = -EADDRNOTAVAIL;
	148	if (err)
	149	goto out_dev_put;
	150	}
	151
	152	err = ipv6_dev_ac_inc(dev, addr);
	153	if (err)
	154	goto out_dev_put;
	155
	156	write_lock_bh(&ipv6_sk_ac_lock);
	157	pac->acl_next = np->ipv6_ac_list;
	158	np->ipv6_ac_list = pac;
	159	write_unlock_bh(&ipv6_sk_ac_lock);
	160
	161	dev_put(dev);
	162
	163	return 0;
	164
	165	out_dev_put:
	166	dev_put(dev);
	167	out_free_pac:
	168	sock_kfree_s(sk, pac, sizeof(*pac));
	169	return err;
	170	}
	171
	172	/*
	173	* socket leave an anycast group
	174	*/
	175	int ipv6_sock_ac_drop(struct sock sk, int ifindex, struct in6_addr addr)
	176	{
	177	struct ipv6_pinfo *np = inet6_sk(sk);
	178	struct net_device *dev;
	179	struct ipv6_ac_socklist pac, prev_pac;
6ab57e7e	180	struct net *net = sock_net(sk);
1da177e4 LT	181
	182	write_lock_bh(&ipv6_sk_ac_lock);
	183	prev_pac = NULL;
	184	for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
	185	if ((ifindex == 0 \|\| pac->acl_ifindex == ifindex) &&
	186	ipv6_addr_equal(&pac->acl_addr, addr))
	187	break;
	188	prev_pac = pac;
	189	}
	190	if (!pac) {
	191	write_unlock_bh(&ipv6_sk_ac_lock);
	192	return -ENOENT;
	193	}
	194	if (prev_pac)
	195	prev_pac->acl_next = pac->acl_next;
	196	else
	197	np->ipv6_ac_list = pac->acl_next;
	198
	199	write_unlock_bh(&ipv6_sk_ac_lock);
	200
6ab57e7e	201	dev = dev_get_by_index(net, pac->acl_ifindex);
1da177e4 LT	202	if (dev) {
	203	ipv6_dev_ac_dec(dev, &pac->acl_addr);
	204	dev_put(dev);
	205	}
	206	sock_kfree_s(sk, pac, sizeof(*pac));
	207	return 0;
	208	}
	209
	210	void ipv6_sock_ac_close(struct sock *sk)
	211	{
	212	struct ipv6_pinfo *np = inet6_sk(sk);
	213	struct net_device *dev = NULL;
	214	struct ipv6_ac_socklist *pac;
6ab57e7e	215	struct net *net = sock_net(sk);
1da177e4 LT	216	int prev_index;
	217
	218	write_lock_bh(&ipv6_sk_ac_lock);
	219	pac = np->ipv6_ac_list;
	220	np->ipv6_ac_list = NULL;
	221	write_unlock_bh(&ipv6_sk_ac_lock);
	222
	223	prev_index = 0;
	224	while (pac) {
	225	struct ipv6_ac_socklist *next = pac->acl_next;
	226
	227	if (pac->acl_ifindex != prev_index) {
	228	if (dev)
	229	dev_put(dev);
6ab57e7e	230	dev = dev_get_by_index(net, pac->acl_ifindex);
1da177e4 LT	231	prev_index = pac->acl_ifindex;
	232	}
	233	if (dev)
	234	ipv6_dev_ac_dec(dev, &pac->acl_addr);
	235	sock_kfree_s(sk, pac, sizeof(*pac));
	236	pac = next;
	237	}
	238	if (dev)
	239	dev_put(dev);
	240	}
	241
	242	#if 0
	243	/* The function is not used, which is funny. Apparently, author
	244	* supposed to use it to filter out datagrams inside udp/raw but forgot.
	245	*
	246	* It is OK, anycasts are not special comparing to delivery to unicasts.
	247	*/
	248
	249	int inet6_ac_check(struct sock sk, struct in6_addr addr, int ifindex)
	250	{
	251	struct ipv6_ac_socklist *pac;
	252	struct ipv6_pinfo *np = inet6_sk(sk);
	253	int found;
	254
	255	found = 0;
	256	read_lock(&ipv6_sk_ac_lock);
	257	for (pac=np->ipv6_ac_list; pac; pac=pac->acl_next) {
	258	if (ifindex && pac->acl_ifindex != ifindex)
	259	continue;
	260	found = ipv6_addr_equal(&pac->acl_addr, addr);
	261	if (found)
	262	break;
	263	}
	264	read_unlock(&ipv6_sk_ac_lock);
	265
	266	return found;
	267	}
	268
	269	#endif
	270
	271	static void aca_put(struct ifacaddr6 *ac)
	272	{
	273	if (atomic_dec_and_test(&ac->aca_refcnt)) {
	274	in6_dev_put(ac->aca_idev);
	275	dst_release(&ac->aca_rt->u.dst);
	276	kfree(ac);
	277	}
	278	}
	279
	280	/*
	281	* device anycast group inc (add if not found)
	282	*/
	283	int ipv6_dev_ac_inc(struct net_device dev, struct in6_addr addr)
	284	{
	285	struct ifacaddr6 *aca;
	286	struct inet6_dev *idev;
	287	struct rt6_info *rt;
	288	int err;
	289
	290	idev = in6_dev_get(dev);
	291
	292	if (idev == NULL)
	293	return -EINVAL;
	294
295	write_lock_bh(&idev->lock);
296	if (idev->dead) {
297	err = -ENODEV;
298	goto out;
299	}
300
301	for (aca = idev->ac_list; aca; aca = aca->aca_next) {
302	if (ipv6_addr_equal(&aca->aca_addr, addr)) {
303	aca->aca_users++;
304	err = 0;
305	goto out;
306	}
307	}
308
309	/*
310	* not found: create a new one.
311	*/
312
0c600eda	313	aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
1da177e4 LT	314
	315	if (aca == NULL) {
	316	err = -ENOMEM;
	317	goto out;
	318	}
	319
	320	rt = addrconf_dst_alloc(idev, addr, 1);
	321	if (IS_ERR(rt)) {
	322	kfree(aca);
	323	err = PTR_ERR(rt);
	324	goto out;
	325	}
	326
1da177e4 LT	327	ipv6_addr_copy(&aca->aca_addr, addr);
	328	aca->aca_idev = idev;
	329	aca->aca_rt = rt;
	330	aca->aca_users = 1;
	331	/* aca_tstamp should be updated upon changes */
	332	aca->aca_cstamp = aca->aca_tstamp = jiffies;
	333	atomic_set(&aca->aca_refcnt, 2);
	334	spin_lock_init(&aca->aca_lock);
	335
	336	aca->aca_next = idev->ac_list;
	337	idev->ac_list = aca;
	338	write_unlock_bh(&idev->lock);
	339
	340	dst_hold(&rt->u.dst);
40e22e8f	341	if (ip6_ins_rt(rt))
1da177e4 LT	342	dst_release(&rt->u.dst);
	343
	344	addrconf_join_solict(dev, &aca->aca_addr);
	345
	346	aca_put(aca);
	347	return 0;
	348	out:
	349	write_unlock_bh(&idev->lock);
	350	in6_dev_put(idev);
	351	return err;
	352	}
	353
	354	/*
	355	* device anycast group decrement
	356	*/
	357	int __ipv6_dev_ac_dec(struct inet6_dev idev, struct in6_addr addr)
	358	{
	359	struct ifacaddr6 aca, prev_aca;
	360
	361	write_lock_bh(&idev->lock);
	362	prev_aca = NULL;
	363	for (aca = idev->ac_list; aca; aca = aca->aca_next) {
	364	if (ipv6_addr_equal(&aca->aca_addr, addr))
	365	break;
	366	prev_aca = aca;
	367	}
	368	if (!aca) {
	369	write_unlock_bh(&idev->lock);
	370	return -ENOENT;
	371	}
	372	if (--aca->aca_users > 0) {
	373	write_unlock_bh(&idev->lock);
	374	return 0;
	375	}
	376	if (prev_aca)
	377	prev_aca->aca_next = aca->aca_next;
	378	else
	379	idev->ac_list = aca->aca_next;
	380	write_unlock_bh(&idev->lock);
	381	addrconf_leave_solict(idev, &aca->aca_addr);
	382
	383	dst_hold(&aca->aca_rt->u.dst);
72d3b2c9	384	if (ip6_del_rt(aca->aca_rt))
1da177e4 LT	385	dst_free(&aca->aca_rt->u.dst);
	386	else
	387	dst_release(&aca->aca_rt->u.dst);
	388
	389	aca_put(aca);
	390	return 0;
	391	}
	392
	393	static int ipv6_dev_ac_dec(struct net_device dev, struct in6_addr addr)
	394	{
	395	int ret;
	396	struct inet6_dev *idev = in6_dev_get(dev);
	397	if (idev == NULL)
	398	return -ENODEV;
	399	ret = __ipv6_dev_ac_dec(idev, addr);
	400	in6_dev_put(idev);
	401	return ret;
	402	}
1ab1457c	403
1da177e4 LT	404	/*
	405	* check if the interface has this anycast address
	406	*/
	407	static int ipv6_chk_acast_dev(struct net_device dev, struct in6_addr addr)
	408	{
	409	struct inet6_dev *idev;
	410	struct ifacaddr6 *aca;
	411
	412	idev = in6_dev_get(dev);
	413	if (idev) {
	414	read_lock_bh(&idev->lock);
	415	for (aca = idev->ac_list; aca; aca = aca->aca_next)
	416	if (ipv6_addr_equal(&aca->aca_addr, addr))
	417	break;
	418	read_unlock_bh(&idev->lock);
	419	in6_dev_put(idev);
cfcabdcc	420	return aca != NULL;
1da177e4 LT	421	}
	422	return 0;
	423	}
	424
	425	/*
	426	* check if given interface (or any, if dev==0) has this anycast address
	427	*/
6ab57e7e DL	428	int ipv6_chk_acast_addr(struct net net, struct net_device dev,
6ab57e7e DL	429	struct in6_addr *addr)
1da177e4	430	{
7562f876 PE	431	int found = 0;
7562f876 PE	432
1da177e4 LT	433	if (dev)
	434	return ipv6_chk_acast_dev(dev, addr);
	435	read_lock(&dev_base_lock);
6ab57e7e	436	for_each_netdev(net, dev)
7562f876 PE	437	if (ipv6_chk_acast_dev(dev, addr)) {
7562f876 PE	438	found = 1;
1da177e4	439	break;
7562f876	440	}
1da177e4	441	read_unlock(&dev_base_lock);
7562f876	442	return found;
1da177e4 LT	443	}
	444
	445
	446	#ifdef CONFIG_PROC_FS
	447	struct ac6_iter_state {
6ab57e7e	448	struct seq_net_private p;
1da177e4 LT	449	struct net_device *dev;
	450	struct inet6_dev *idev;
	451	};
	452
	453	#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
	454
	455	static inline struct ifacaddr6 ac6_get_first(struct seq_file seq)
	456	{
	457	struct ifacaddr6 *im = NULL;
	458	struct ac6_iter_state *state = ac6_seq_private(seq);
6ab57e7e	459	struct net *net = seq_file_net(seq);
1da177e4	460
7562f876	461	state->idev = NULL;
6ab57e7e	462	for_each_netdev(net, state->dev) {
1da177e4 LT	463	struct inet6_dev *idev;
	464	idev = in6_dev_get(state->dev);
	465	if (!idev)
	466	continue;
	467	read_lock_bh(&idev->lock);
	468	im = idev->ac_list;
	469	if (im) {
	470	state->idev = idev;
	471	break;
	472	}
	473	read_unlock_bh(&idev->lock);
aa6e4a96	474	in6_dev_put(idev);
1da177e4 LT	475	}
	476	return im;
	477	}
	478
	479	static struct ifacaddr6 ac6_get_next(struct seq_file seq, struct ifacaddr6 *im)
	480	{
	481	struct ac6_iter_state *state = ac6_seq_private(seq);
	482
	483	im = im->aca_next;
	484	while (!im) {
	485	if (likely(state->idev != NULL)) {
	486	read_unlock_bh(&state->idev->lock);
	487	in6_dev_put(state->idev);
	488	}
7562f876	489	state->dev = next_net_device(state->dev);
1da177e4 LT	490	if (!state->dev) {
	491	state->idev = NULL;
	492	break;
	493	}
	494	state->idev = in6_dev_get(state->dev);
	495	if (!state->idev)
	496	continue;
	497	read_lock_bh(&state->idev->lock);
	498	im = state->idev->ac_list;
	499	}
	500	return im;
	501	}
	502
	503	static struct ifacaddr6 ac6_get_idx(struct seq_file seq, loff_t pos)
	504	{
	505	struct ifacaddr6 *im = ac6_get_first(seq);
	506	if (im)
	507	while (pos && (im = ac6_get_next(seq, im)) != NULL)
	508	--pos;
	509	return pos ? NULL : im;
	510	}
	511
	512	static void ac6_seq_start(struct seq_file seq, loff_t *pos)
9a429c49	513	__acquires(dev_base_lock)
1da177e4 LT	514	{
	515	read_lock(&dev_base_lock);
	516	return ac6_get_idx(seq, *pos);
	517	}
	518
	519	static void ac6_seq_next(struct seq_file seq, void v, loff_t pos)
	520	{
	521	struct ifacaddr6 *im;
	522	im = ac6_get_next(seq, v);
	523	++*pos;
	524	return im;
	525	}
	526
	527	static void ac6_seq_stop(struct seq_file seq, void v)
9a429c49	528	__releases(dev_base_lock)
1da177e4 LT	529	{
	530	struct ac6_iter_state *state = ac6_seq_private(seq);
	531	if (likely(state->idev != NULL)) {
	532	read_unlock_bh(&state->idev->lock);
	533	in6_dev_put(state->idev);
	534	}
	535	read_unlock(&dev_base_lock);
	536	}
	537
	538	static int ac6_seq_show(struct seq_file seq, void v)
	539	{
	540	struct ifacaddr6 im = (struct ifacaddr6 )v;
	541	struct ac6_iter_state *state = ac6_seq_private(seq);
	542
	543	seq_printf(seq,
9343e79a	544	"%-4d %-15s " NIP6_SEQFMT " %5d\n",
1da177e4 LT	545	state->dev->ifindex, state->dev->name,
	546	NIP6(im->aca_addr),
	547	im->aca_users);
	548	return 0;
	549	}
	550
56b3d975	551	static const struct seq_operations ac6_seq_ops = {
1da177e4 LT	552	.start = ac6_seq_start,
	553	.next = ac6_seq_next,
	554	.stop = ac6_seq_stop,
	555	.show = ac6_seq_show,
	556	};
	557
	558	static int ac6_seq_open(struct inode inode, struct file file)
	559	{
6ab57e7e DL	560	return seq_open_net(inode, file, &ac6_seq_ops,
6ab57e7e DL	561	sizeof(struct ac6_iter_state));
1da177e4 LT	562	}
1da177e4 LT	563
9a32144e	564	static const struct file_operations ac6_seq_fops = {
1da177e4 LT	565	.owner = THIS_MODULE,
	566	.open = ac6_seq_open,
	567	.read = seq_read,
	568	.llseek = seq_lseek,
6ab57e7e	569	.release = seq_release_net,
1da177e4 LT	570	};
1da177e4 LT	571
6ab57e7e	572	int ac6_proc_init(struct net *net)
1da177e4	573	{
6ab57e7e	574	if (!proc_net_fops_create(net, "anycast6", S_IRUGO, &ac6_seq_fops))
1da177e4 LT	575	return -ENOMEM;
	576
	577	return 0;
	578	}
	579
6ab57e7e	580	void ac6_proc_exit(struct net *net)
1da177e4	581	{
6ab57e7e	582	proc_net_remove(net, "anycast6");
1da177e4 LT	583	}
	584	#endif
	585