[deliverable/linux.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 <linux/slab.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, const struct in6_addr *addr);

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


/*
 *	socket join an anycast group
 */

int ipv6_sock_ac_join(struct sock *sk, int ifindex, const 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 (!ns_capable(net->user_ns, 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;
	pac->acl_addr = *addr;

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

		rt = rt6_lookup(net, addr, NULL, 0, 0);
		if (rt) {
			dev = rt->dst.dev;
			ip6_rt_put(rt);
		} else if (ishost) {
			err = -EADDRNOTAVAIL;
			goto error;
		} else {
			/* router, no matching interface: just pick one */
			dev = dev_get_by_flags_rcu(net, IFF_UP,
						   IFF_UP | IFF_LOOPBACK);
		}
	} else
		dev = dev_get_by_index_rcu(net, ifindex);

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

	idev = __in6_dev_get(dev);
	if (!idev) {
		if (ifindex)
			err = -ENODEV;
		else
			err = -EADDRNOTAVAIL;
		goto error;
	}
	/* reset ishost, now that we have a specific device */
	ishost = !idev->cnf.forwarding;

	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 error;
	}

	err = ipv6_dev_ac_inc(dev, addr);
	if (!err) {
		spin_lock_bh(&ipv6_sk_ac_lock);
		pac->acl_next = np->ipv6_ac_list;
		np->ipv6_ac_list = pac;
		spin_unlock_bh(&ipv6_sk_ac_lock);
		pac = NULL;
	}

error:
	rcu_read_unlock();
	rtnl_unlock();
	if (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, const 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);

	spin_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) {
		spin_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;

	spin_unlock_bh(&ipv6_sk_ac_lock);

	rtnl_lock();
	rcu_read_lock();
	dev = dev_get_by_index_rcu(net, pac->acl_ifindex);
	if (dev)
		ipv6_dev_ac_dec(dev, &pac->acl_addr);
	rcu_read_unlock();
	rtnl_unlock();

	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;

	if (!np->ipv6_ac_list)
		return;

	spin_lock_bh(&ipv6_sk_ac_lock);
	pac = np->ipv6_ac_list;
	np->ipv6_ac_list = NULL;
	spin_unlock_bh(&ipv6_sk_ac_lock);

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

		if (pac->acl_ifindex != prev_index) {
			dev = dev_get_by_index_rcu(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;
	}
	rcu_read_unlock();
	rtnl_unlock();
}

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->dst);
		kfree(ac);
	}
}

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

	ASSERT_RTNL();

	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, true);
	if (IS_ERR(rt)) {
		kfree(aca);
		err = PTR_ERR(rt);
		goto out;
	}

	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, const struct in6_addr *addr)
{
	struct ifacaddr6 *aca, *prev_aca;

	ASSERT_RTNL();

	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->dst);
	ip6_del_rt(aca->aca_rt);

	aca_put(aca);
	return 0;
}

/* called with rcu_read_lock() */
static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr)
{
	struct inet6_dev *idev = __in6_dev_get(dev);

	if (idev == NULL)
		return -ENODEV;
	return __ipv6_dev_ac_dec(idev, addr);
}

/*
 *	check if the interface has this anycast address
 *	called with rcu_read_lock()
 */
static bool ipv6_chk_acast_dev(struct net_device *dev, const 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);
		return aca != NULL;
	}
	return false;
}

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

	rcu_read_lock();
	if (dev)
		found = ipv6_chk_acast_dev(dev, addr);
	else
		for_each_netdev_rcu(net, dev)
			if (ipv6_chk_acast_dev(dev, addr)) {
				found = true;
				break;
			}
	rcu_read_unlock();
	return found;
}

/*	check if this anycast address is link-local on given interface or
 *	is global
 */
bool ipv6_chk_acast_addr_src(struct net *net, struct net_device *dev,
			     const struct in6_addr *addr)
{
	return ipv6_chk_acast_addr(net,
				   (ipv6_addr_type(addr) & IPV6_ADDR_LINKLOCAL ?
				    dev : NULL),
				   addr);
}

#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_rcu(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);
	}
	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);

		state->dev = next_net_device_rcu(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(RCU)
{
	rcu_read_lock();
	return ac6_get_idx(seq, *pos);
}

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

	++*pos;
	return im;
}

static void ac6_seq_stop(struct seq_file *seq, void *v)
	__releases(RCU)
{
	struct ac6_iter_state *state = ac6_seq_private(seq);

	if (likely(state->idev != NULL)) {
		read_unlock_bh(&state->idev->lock);
		state->idev = NULL;
	}
	rcu_read_unlock();
}

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 __net_init ac6_proc_init(struct net *net)
{
	if (!proc_create("anycast6", S_IRUGO, net->proc_net, &ac6_seq_fops))
		return -ENOMEM;

	return 0;
}

void ac6_proc_exit(struct net *net)
{
	remove_proc_entry("anycast6", net->proc_net);
}
#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>
5a0e3ad6	32	#include <linux/slab.h>
1da177e4	33
457c4cbc	34	#include <net/net_namespace.h>
1da177e4 LT	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
b71d1d42	47	static int ipv6_dev_ac_dec(struct net_device dev, const struct in6_addr addr);
1da177e4 LT	48
1da177e4 LT	49	/* Big ac list lock for all the sockets */
c33e7b05	50	static DEFINE_SPINLOCK(ipv6_sk_ac_lock);
1da177e4	51
1da177e4 LT	52
	53	/*
	54	* socket join an anycast group
	55	*/
	56
b71d1d42	57	int ipv6_sock_ac_join(struct sock sk, int ifindex, const struct in6_addr addr)
1da177e4 LT	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;
6ab57e7e	63	struct net *net = sock_net(sk);
53b7997f	64	int ishost = !net->ipv6.devconf_all->forwarding;
1da177e4 LT	65	int err = 0;
1da177e4 LT	66
af31f412	67	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1da177e4 LT	68	return -EPERM;
	69	if (ipv6_addr_is_multicast(addr))
	70	return -EINVAL;
6ab57e7e	71	if (ipv6_chk_addr(net, addr, NULL, 0))
1da177e4 LT	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;
4e3fd7a0	78	pac->acl_addr = *addr;
1da177e4	79
a9ed4a29	80	rtnl_lock();
bb69ae04	81	rcu_read_lock();
1da177e4 LT	82	if (ifindex == 0) {
	83	struct rt6_info *rt;
	84
6ab57e7e	85	rt = rt6_lookup(net, addr, NULL, 0, 0);
1da177e4	86	if (rt) {
d1918542	87	dev = rt->dst.dev;
94e187c0	88	ip6_rt_put(rt);
1da177e4 LT	89	} else if (ishost) {
1da177e4 LT	90	err = -EADDRNOTAVAIL;
bb69ae04	91	goto error;
1da177e4 LT	92	} else {
1da177e4 LT	93	/* router, no matching interface: just pick one */
bb69ae04 ED	94	dev = dev_get_by_flags_rcu(net, IFF_UP,
bb69ae04 ED	95	IFF_UP \| IFF_LOOPBACK);
1da177e4 LT	96	}
1da177e4 LT	97	} else
bb69ae04	98	dev = dev_get_by_index_rcu(net, ifindex);
1da177e4 LT	99
	100	if (dev == NULL) {
	101	err = -ENODEV;
bb69ae04	102	goto error;
1da177e4 LT	103	}
1da177e4 LT	104
bb69ae04	105	idev = __in6_dev_get(dev);
1da177e4 LT	106	if (!idev) {
	107	if (ifindex)
	108	err = -ENODEV;
	109	else
	110	err = -EADDRNOTAVAIL;
bb69ae04	111	goto error;
1da177e4 LT	112	}
	113	/* reset ishost, now that we have a specific device */
	114	ishost = !idev->cnf.forwarding;
1da177e4 LT	115
	116	pac->acl_ifindex = dev->ifindex;
	117
	118	/* XXX
	119	* For hosts, allow link-local or matching prefix anycasts.
	120	* This obviates the need for propagating anycast routes while
	121	* still allowing some non-router anycast participation.
	122	*/
52eeeb84	123	if (!ipv6_chk_prefix(addr, dev)) {
1da177e4 LT	124	if (ishost)
	125	err = -EADDRNOTAVAIL;
	126	if (err)
bb69ae04	127	goto error;
1da177e4 LT	128	}
	129
	130	err = ipv6_dev_ac_inc(dev, addr);
bb69ae04	131	if (!err) {
c33e7b05	132	spin_lock_bh(&ipv6_sk_ac_lock);
bb69ae04 ED	133	pac->acl_next = np->ipv6_ac_list;
bb69ae04 ED	134	np->ipv6_ac_list = pac;
c33e7b05	135	spin_unlock_bh(&ipv6_sk_ac_lock);
bb69ae04 ED	136	pac = NULL;
bb69ae04 ED	137	}
1da177e4	138
bb69ae04 ED	139	error:
bb69ae04 ED	140	rcu_read_unlock();
a9ed4a29	141	rtnl_unlock();
bb69ae04 ED	142	if (pac)
bb69ae04 ED	143	sock_kfree_s(sk, pac, sizeof(*pac));
1da177e4 LT	144	return err;
	145	}
	146
	147	/*
	148	* socket leave an anycast group
	149	*/
b71d1d42	150	int ipv6_sock_ac_drop(struct sock sk, int ifindex, const struct in6_addr addr)
1da177e4 LT	151	{
	152	struct ipv6_pinfo *np = inet6_sk(sk);
	153	struct net_device *dev;
	154	struct ipv6_ac_socklist pac, prev_pac;
6ab57e7e	155	struct net *net = sock_net(sk);
1da177e4	156
c33e7b05	157	spin_lock_bh(&ipv6_sk_ac_lock);
1da177e4 LT	158	prev_pac = NULL;
	159	for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
	160	if ((ifindex == 0 \|\| pac->acl_ifindex == ifindex) &&
	161	ipv6_addr_equal(&pac->acl_addr, addr))
	162	break;
	163	prev_pac = pac;
	164	}
	165	if (!pac) {
c33e7b05	166	spin_unlock_bh(&ipv6_sk_ac_lock);
1da177e4 LT	167	return -ENOENT;
	168	}
	169	if (prev_pac)
	170	prev_pac->acl_next = pac->acl_next;
	171	else
	172	np->ipv6_ac_list = pac->acl_next;
	173
c33e7b05	174	spin_unlock_bh(&ipv6_sk_ac_lock);
1da177e4	175
a9ed4a29	176	rtnl_lock();
bb69ae04 ED	177	rcu_read_lock();
	178	dev = dev_get_by_index_rcu(net, pac->acl_ifindex);
	179	if (dev)
1da177e4	180	ipv6_dev_ac_dec(dev, &pac->acl_addr);
bb69ae04	181	rcu_read_unlock();
a9ed4a29	182	rtnl_unlock();
bb69ae04	183
1da177e4 LT	184	sock_kfree_s(sk, pac, sizeof(*pac));
	185	return 0;
	186	}
	187
	188	void ipv6_sock_ac_close(struct sock *sk)
	189	{
	190	struct ipv6_pinfo *np = inet6_sk(sk);
	191	struct net_device *dev = NULL;
	192	struct ipv6_ac_socklist *pac;
6ab57e7e	193	struct net *net = sock_net(sk);
1da177e4 LT	194	int prev_index;
1da177e4 LT	195
0e1efe9d ED	196	if (!np->ipv6_ac_list)
	197	return;
	198
c33e7b05	199	spin_lock_bh(&ipv6_sk_ac_lock);
1da177e4 LT	200	pac = np->ipv6_ac_list;
1da177e4 LT	201	np->ipv6_ac_list = NULL;
c33e7b05	202	spin_unlock_bh(&ipv6_sk_ac_lock);
1da177e4 LT	203
1da177e4 LT	204	prev_index = 0;
a9ed4a29	205	rtnl_lock();
bb69ae04	206	rcu_read_lock();
1da177e4 LT	207	while (pac) {
	208	struct ipv6_ac_socklist *next = pac->acl_next;
	209
	210	if (pac->acl_ifindex != prev_index) {
bb69ae04	211	dev = dev_get_by_index_rcu(net, pac->acl_ifindex);
1da177e4 LT	212	prev_index = pac->acl_ifindex;
	213	}
	214	if (dev)
	215	ipv6_dev_ac_dec(dev, &pac->acl_addr);
	216	sock_kfree_s(sk, pac, sizeof(*pac));
	217	pac = next;
	218	}
bb69ae04	219	rcu_read_unlock();
a9ed4a29	220	rtnl_unlock();
1da177e4 LT	221	}
1da177e4 LT	222
1da177e4 LT	223	static void aca_put(struct ifacaddr6 *ac)
	224	{
	225	if (atomic_dec_and_test(&ac->aca_refcnt)) {
	226	in6_dev_put(ac->aca_idev);
d8d1f30b	227	dst_release(&ac->aca_rt->dst);
1da177e4 LT	228	kfree(ac);
	229	}
	230	}
	231
	232	/*
	233	* device anycast group inc (add if not found)
	234	*/
b71d1d42	235	int ipv6_dev_ac_inc(struct net_device dev, const struct in6_addr addr)
1da177e4 LT	236	{
	237	struct ifacaddr6 *aca;
	238	struct inet6_dev *idev;
	239	struct rt6_info *rt;
	240	int err;
	241
a9ed4a29 SD	242	ASSERT_RTNL();
a9ed4a29 SD	243
1da177e4 LT	244	idev = in6_dev_get(dev);
	245
	246	if (idev == NULL)
	247	return -EINVAL;
	248
	249	write_lock_bh(&idev->lock);
	250	if (idev->dead) {
	251	err = -ENODEV;
	252	goto out;
	253	}
	254
	255	for (aca = idev->ac_list; aca; aca = aca->aca_next) {
	256	if (ipv6_addr_equal(&aca->aca_addr, addr)) {
	257	aca->aca_users++;
	258	err = 0;
	259	goto out;
	260	}
	261	}
	262
	263	/*
	264	* not found: create a new one.
	265	*/
	266
0c600eda	267	aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
1da177e4 LT	268
	269	if (aca == NULL) {
	270	err = -ENOMEM;
	271	goto out;
	272	}
	273
8f031519	274	rt = addrconf_dst_alloc(idev, addr, true);
1da177e4 LT	275	if (IS_ERR(rt)) {
	276	kfree(aca);
	277	err = PTR_ERR(rt);
	278	goto out;
	279	}
	280
4e3fd7a0	281	aca->aca_addr = *addr;
1da177e4 LT	282	aca->aca_idev = idev;
	283	aca->aca_rt = rt;
	284	aca->aca_users = 1;
	285	/* aca_tstamp should be updated upon changes */
	286	aca->aca_cstamp = aca->aca_tstamp = jiffies;
	287	atomic_set(&aca->aca_refcnt, 2);
	288	spin_lock_init(&aca->aca_lock);
	289
	290	aca->aca_next = idev->ac_list;
	291	idev->ac_list = aca;
	292	write_unlock_bh(&idev->lock);
	293
84f59370	294	ip6_ins_rt(rt);
1da177e4 LT	295
	296	addrconf_join_solict(dev, &aca->aca_addr);
	297
	298	aca_put(aca);
	299	return 0;
	300	out:
	301	write_unlock_bh(&idev->lock);
	302	in6_dev_put(idev);
	303	return err;
	304	}
	305
	306	/*
	307	* device anycast group decrement
	308	*/
b71d1d42	309	int __ipv6_dev_ac_dec(struct inet6_dev idev, const struct in6_addr addr)
1da177e4 LT	310	{
	311	struct ifacaddr6 aca, prev_aca;
	312
a9ed4a29 SD	313	ASSERT_RTNL();
a9ed4a29 SD	314
1da177e4 LT	315	write_lock_bh(&idev->lock);
	316	prev_aca = NULL;
	317	for (aca = idev->ac_list; aca; aca = aca->aca_next) {
	318	if (ipv6_addr_equal(&aca->aca_addr, addr))
	319	break;
	320	prev_aca = aca;
	321	}
	322	if (!aca) {
	323	write_unlock_bh(&idev->lock);
	324	return -ENOENT;
	325	}
	326	if (--aca->aca_users > 0) {
	327	write_unlock_bh(&idev->lock);
	328	return 0;
	329	}
	330	if (prev_aca)
	331	prev_aca->aca_next = aca->aca_next;
	332	else
	333	idev->ac_list = aca->aca_next;
	334	write_unlock_bh(&idev->lock);
	335	addrconf_leave_solict(idev, &aca->aca_addr);
	336
d8d1f30b	337	dst_hold(&aca->aca_rt->dst);
84f59370	338	ip6_del_rt(aca->aca_rt);
1da177e4 LT	339
	340	aca_put(aca);
	341	return 0;
	342	}
	343
bb69ae04	344	/* called with rcu_read_lock() */
b71d1d42	345	static int ipv6_dev_ac_dec(struct net_device dev, const struct in6_addr addr)
1da177e4	346	{
bb69ae04 ED	347	struct inet6_dev *idev = __in6_dev_get(dev);
bb69ae04 ED	348
1da177e4 LT	349	if (idev == NULL)
1da177e4 LT	350	return -ENODEV;
bb69ae04	351	return __ipv6_dev_ac_dec(idev, addr);
1da177e4	352	}
1ab1457c	353
1da177e4 LT	354	/*
1da177e4 LT	355	* check if the interface has this anycast address
bb69ae04	356	* called with rcu_read_lock()
1da177e4	357	*/
a50feda5	358	static bool ipv6_chk_acast_dev(struct net_device dev, const struct in6_addr addr)
1da177e4 LT	359	{
	360	struct inet6_dev *idev;
	361	struct ifacaddr6 *aca;
	362
bb69ae04	363	idev = __in6_dev_get(dev);
1da177e4 LT	364	if (idev) {
	365	read_lock_bh(&idev->lock);
	366	for (aca = idev->ac_list; aca; aca = aca->aca_next)
	367	if (ipv6_addr_equal(&aca->aca_addr, addr))
	368	break;
	369	read_unlock_bh(&idev->lock);
cfcabdcc	370	return aca != NULL;
1da177e4	371	}
a50feda5	372	return false;
1da177e4 LT	373	}
	374
	375	/*
	376	* check if given interface (or any, if dev==0) has this anycast address
	377	*/
a50feda5 ED	378	bool ipv6_chk_acast_addr(struct net net, struct net_device dev,
a50feda5 ED	379	const struct in6_addr *addr)
1da177e4	380	{
a50feda5	381	bool found = false;
7562f876	382
c6d14c84	383	rcu_read_lock();
bb69ae04 ED	384	if (dev)
	385	found = ipv6_chk_acast_dev(dev, addr);
	386	else
	387	for_each_netdev_rcu(net, dev)
	388	if (ipv6_chk_acast_dev(dev, addr)) {
a50feda5	389	found = true;
bb69ae04 ED	390	break;
bb69ae04 ED	391	}
c6d14c84	392	rcu_read_unlock();
7562f876	393	return found;
1da177e4 LT	394	}
1da177e4 LT	395
7c90cc2d FLB	396	/* check if this anycast address is link-local on given interface or
	397	* is global
	398	*/
	399	bool ipv6_chk_acast_addr_src(struct net net, struct net_device dev,
	400	const struct in6_addr *addr)
	401	{
	402	return ipv6_chk_acast_addr(net,
	403	(ipv6_addr_type(addr) & IPV6_ADDR_LINKLOCAL ?
	404	dev : NULL),
	405	addr);
	406	}
1da177e4 LT	407
	408	#ifdef CONFIG_PROC_FS
	409	struct ac6_iter_state {
6ab57e7e	410	struct seq_net_private p;
1da177e4 LT	411	struct net_device *dev;
	412	struct inet6_dev *idev;
	413	};
	414
	415	#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
	416
	417	static inline struct ifacaddr6 ac6_get_first(struct seq_file seq)
	418	{
	419	struct ifacaddr6 *im = NULL;
	420	struct ac6_iter_state *state = ac6_seq_private(seq);
6ab57e7e	421	struct net *net = seq_file_net(seq);
1da177e4	422
7562f876	423	state->idev = NULL;
ce81b76a	424	for_each_netdev_rcu(net, state->dev) {
1da177e4	425	struct inet6_dev *idev;
ce81b76a	426	idev = __in6_dev_get(state->dev);
1da177e4 LT	427	if (!idev)
	428	continue;
	429	read_lock_bh(&idev->lock);
	430	im = idev->ac_list;
	431	if (im) {
	432	state->idev = idev;
	433	break;
	434	}
	435	read_unlock_bh(&idev->lock);
	436	}
	437	return im;
	438	}
	439
	440	static struct ifacaddr6 ac6_get_next(struct seq_file seq, struct ifacaddr6 *im)
	441	{
	442	struct ac6_iter_state *state = ac6_seq_private(seq);
	443
	444	im = im->aca_next;
	445	while (!im) {
ce81b76a	446	if (likely(state->idev != NULL))
1da177e4	447	read_unlock_bh(&state->idev->lock);
ce81b76a ED	448
ce81b76a ED	449	state->dev = next_net_device_rcu(state->dev);
1da177e4 LT	450	if (!state->dev) {
	451	state->idev = NULL;
	452	break;
	453	}
ce81b76a	454	state->idev = __in6_dev_get(state->dev);
1da177e4 LT	455	if (!state->idev)
	456	continue;
	457	read_lock_bh(&state->idev->lock);
	458	im = state->idev->ac_list;
	459	}
	460	return im;
	461	}
	462
	463	static struct ifacaddr6 ac6_get_idx(struct seq_file seq, loff_t pos)
	464	{
	465	struct ifacaddr6 *im = ac6_get_first(seq);
	466	if (im)
	467	while (pos && (im = ac6_get_next(seq, im)) != NULL)
	468	--pos;
	469	return pos ? NULL : im;
	470	}
	471
	472	static void ac6_seq_start(struct seq_file seq, loff_t *pos)
ce81b76a	473	__acquires(RCU)
1da177e4	474	{
ce81b76a	475	rcu_read_lock();
1da177e4 LT	476	return ac6_get_idx(seq, *pos);
	477	}
	478
	479	static void ac6_seq_next(struct seq_file seq, void v, loff_t pos)
	480	{
ce81b76a ED	481	struct ifacaddr6 *im = ac6_get_next(seq, v);
ce81b76a ED	482
1da177e4 LT	483	++*pos;
	484	return im;
	485	}
	486
	487	static void ac6_seq_stop(struct seq_file seq, void v)
ce81b76a	488	__releases(RCU)
1da177e4 LT	489	{
1da177e4 LT	490	struct ac6_iter_state *state = ac6_seq_private(seq);
ce81b76a	491
1da177e4 LT	492	if (likely(state->idev != NULL)) {
1da177e4 LT	493	read_unlock_bh(&state->idev->lock);
ce81b76a	494	state->idev = NULL;
1da177e4	495	}
ce81b76a	496	rcu_read_unlock();
1da177e4 LT	497	}
	498
	499	static int ac6_seq_show(struct seq_file seq, void v)
	500	{
	501	struct ifacaddr6 im = (struct ifacaddr6 )v;
	502	struct ac6_iter_state *state = ac6_seq_private(seq);
	503
4b7a4274	504	seq_printf(seq, "%-4d %-15s %pi6 %5d\n",
1da177e4	505	state->dev->ifindex, state->dev->name,
b071195d	506	&im->aca_addr, im->aca_users);
1da177e4 LT	507	return 0;
	508	}
	509
56b3d975	510	static const struct seq_operations ac6_seq_ops = {
1da177e4 LT	511	.start = ac6_seq_start,
	512	.next = ac6_seq_next,
	513	.stop = ac6_seq_stop,
	514	.show = ac6_seq_show,
	515	};
	516
	517	static int ac6_seq_open(struct inode inode, struct file file)
	518	{
6ab57e7e DL	519	return seq_open_net(inode, file, &ac6_seq_ops,
6ab57e7e DL	520	sizeof(struct ac6_iter_state));
1da177e4 LT	521	}
1da177e4 LT	522
9a32144e	523	static const struct file_operations ac6_seq_fops = {
1da177e4 LT	524	.owner = THIS_MODULE,
	525	.open = ac6_seq_open,
	526	.read = seq_read,
	527	.llseek = seq_lseek,
6ab57e7e	528	.release = seq_release_net,
1da177e4 LT	529	};
1da177e4 LT	530
2c8c1e72	531	int __net_init ac6_proc_init(struct net *net)
1da177e4	532	{
d4beaa66	533	if (!proc_create("anycast6", S_IRUGO, net->proc_net, &ac6_seq_fops))
1da177e4 LT	534	return -ENOMEM;
	535
	536	return 0;
	537	}
	538
6ab57e7e	539	void ac6_proc_exit(struct net *net)
1da177e4	540	{
ece31ffd	541	remove_proc_entry("anycast6", net->proc_net);
1da177e4 LT	542	}
	543	#endif
	544