[mirror_ubuntu-artful-kernel.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();
	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(net, IFF_UP,
						 IFF_UP | IFF_LOOPBACK);
		}
	} else
		dev = __dev_get_by_index(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:
	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();
	dev = __dev_get_by_index(net, pac->acl_ifindex);
	if (dev)
		ipv6_dev_ac_dec(dev, &pac->acl_addr);
	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();
	while (pac) {
		struct ipv6_ac_socklist *next = pac->acl_next;

		if (pac->acl_ifindex != prev_index) {
			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;
	}
	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 rtnl_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();
1da177e4 LT	81	if (ifindex == 0) {
	82	struct rt6_info *rt;
	83
6ab57e7e	84	rt = rt6_lookup(net, addr, NULL, 0, 0);
1da177e4	85	if (rt) {
d1918542	86	dev = rt->dst.dev;
94e187c0	87	ip6_rt_put(rt);
1da177e4 LT	88	} else if (ishost) {
1da177e4 LT	89	err = -EADDRNOTAVAIL;
bb69ae04	90	goto error;
1da177e4 LT	91	} else {
1da177e4 LT	92	/* router, no matching interface: just pick one */
6c555490 WC	93	dev = __dev_get_by_flags(net, IFF_UP,
6c555490 WC	94	IFF_UP \| IFF_LOOPBACK);
1da177e4 LT	95	}
1da177e4 LT	96	} else
6c555490	97	dev = __dev_get_by_index(net, ifindex);
1da177e4 LT	98
	99	if (dev == NULL) {
	100	err = -ENODEV;
bb69ae04	101	goto error;
1da177e4 LT	102	}
1da177e4 LT	103
bb69ae04	104	idev = __in6_dev_get(dev);
1da177e4 LT	105	if (!idev) {
	106	if (ifindex)
	107	err = -ENODEV;
	108	else
	109	err = -EADDRNOTAVAIL;
bb69ae04	110	goto error;
1da177e4 LT	111	}
	112	/* reset ishost, now that we have a specific device */
	113	ishost = !idev->cnf.forwarding;
1da177e4 LT	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)
bb69ae04	126	goto error;
1da177e4 LT	127	}
	128
	129	err = ipv6_dev_ac_inc(dev, addr);
bb69ae04	130	if (!err) {
c33e7b05	131	spin_lock_bh(&ipv6_sk_ac_lock);
bb69ae04 ED	132	pac->acl_next = np->ipv6_ac_list;
bb69ae04 ED	133	np->ipv6_ac_list = pac;
c33e7b05	134	spin_unlock_bh(&ipv6_sk_ac_lock);
bb69ae04 ED	135	pac = NULL;
bb69ae04 ED	136	}
1da177e4	137
bb69ae04	138	error:
a9ed4a29	139	rtnl_unlock();
bb69ae04 ED	140	if (pac)
bb69ae04 ED	141	sock_kfree_s(sk, pac, sizeof(*pac));
1da177e4 LT	142	return err;
	143	}
	144
	145	/*
	146	* socket leave an anycast group
	147	*/
b71d1d42	148	int ipv6_sock_ac_drop(struct sock sk, int ifindex, const struct in6_addr addr)
1da177e4 LT	149	{
	150	struct ipv6_pinfo *np = inet6_sk(sk);
	151	struct net_device *dev;
	152	struct ipv6_ac_socklist pac, prev_pac;
6ab57e7e	153	struct net *net = sock_net(sk);
1da177e4	154
c33e7b05	155	spin_lock_bh(&ipv6_sk_ac_lock);
1da177e4 LT	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) {
c33e7b05	164	spin_unlock_bh(&ipv6_sk_ac_lock);
1da177e4 LT	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
c33e7b05	172	spin_unlock_bh(&ipv6_sk_ac_lock);
1da177e4	173
a9ed4a29	174	rtnl_lock();
6c555490	175	dev = __dev_get_by_index(net, pac->acl_ifindex);
bb69ae04	176	if (dev)
1da177e4	177	ipv6_dev_ac_dec(dev, &pac->acl_addr);
a9ed4a29	178	rtnl_unlock();
bb69ae04	179
1da177e4 LT	180	sock_kfree_s(sk, pac, sizeof(*pac));
	181	return 0;
	182	}
	183
	184	void 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;
6ab57e7e	189	struct net *net = sock_net(sk);
1da177e4 LT	190	int prev_index;
1da177e4 LT	191
0e1efe9d ED	192	if (!np->ipv6_ac_list)
	193	return;
	194
c33e7b05	195	spin_lock_bh(&ipv6_sk_ac_lock);
1da177e4 LT	196	pac = np->ipv6_ac_list;
1da177e4 LT	197	np->ipv6_ac_list = NULL;
c33e7b05	198	spin_unlock_bh(&ipv6_sk_ac_lock);
1da177e4 LT	199
1da177e4 LT	200	prev_index = 0;
a9ed4a29	201	rtnl_lock();
1da177e4 LT	202	while (pac) {
	203	struct ipv6_ac_socklist *next = pac->acl_next;
	204
	205	if (pac->acl_ifindex != prev_index) {
6c555490	206	dev = __dev_get_by_index(net, pac->acl_ifindex);
1da177e4 LT	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	}
a9ed4a29	214	rtnl_unlock();
1da177e4 LT	215	}
1da177e4 LT	216
1da177e4 LT	217	static void aca_put(struct ifacaddr6 *ac)
	218	{
	219	if (atomic_dec_and_test(&ac->aca_refcnt)) {
	220	in6_dev_put(ac->aca_idev);
d8d1f30b	221	dst_release(&ac->aca_rt->dst);
1da177e4 LT	222	kfree(ac);
	223	}
	224	}
	225
	226	/*
	227	* device anycast group inc (add if not found)
	228	*/
b71d1d42	229	int ipv6_dev_ac_inc(struct net_device dev, const struct in6_addr addr)
1da177e4 LT	230	{
	231	struct ifacaddr6 *aca;
	232	struct inet6_dev *idev;
	233	struct rt6_info *rt;
	234	int err;
	235
a9ed4a29 SD	236	ASSERT_RTNL();
a9ed4a29 SD	237
1da177e4 LT	238	idev = in6_dev_get(dev);
	239
	240	if (idev == NULL)
	241	return -EINVAL;
	242
	243	write_lock_bh(&idev->lock);
	244	if (idev->dead) {
	245	err = -ENODEV;
	246	goto out;
	247	}
	248
	249	for (aca = idev->ac_list; aca; aca = aca->aca_next) {
	250	if (ipv6_addr_equal(&aca->aca_addr, addr)) {
	251	aca->aca_users++;
	252	err = 0;
	253	goto out;
	254	}
	255	}
	256
	257	/*
	258	* not found: create a new one.
	259	*/
	260
0c600eda	261	aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
1da177e4 LT	262
	263	if (aca == NULL) {
	264	err = -ENOMEM;
	265	goto out;
	266	}
	267
8f031519	268	rt = addrconf_dst_alloc(idev, addr, true);
1da177e4 LT	269	if (IS_ERR(rt)) {
	270	kfree(aca);
	271	err = PTR_ERR(rt);
	272	goto out;
	273	}
	274
4e3fd7a0	275	aca->aca_addr = *addr;
1da177e4 LT	276	aca->aca_idev = idev;
	277	aca->aca_rt = rt;
	278	aca->aca_users = 1;
	279	/* aca_tstamp should be updated upon changes */
	280	aca->aca_cstamp = aca->aca_tstamp = jiffies;
	281	atomic_set(&aca->aca_refcnt, 2);
	282	spin_lock_init(&aca->aca_lock);
	283
	284	aca->aca_next = idev->ac_list;
	285	idev->ac_list = aca;
	286	write_unlock_bh(&idev->lock);
	287
84f59370	288	ip6_ins_rt(rt);
1da177e4 LT	289
	290	addrconf_join_solict(dev, &aca->aca_addr);
	291
	292	aca_put(aca);
	293	return 0;
	294	out:
	295	write_unlock_bh(&idev->lock);
	296	in6_dev_put(idev);
	297	return err;
	298	}
	299
	300	/*
	301	* device anycast group decrement
	302	*/
b71d1d42	303	int __ipv6_dev_ac_dec(struct inet6_dev idev, const struct in6_addr addr)
1da177e4 LT	304	{
	305	struct ifacaddr6 aca, prev_aca;
	306
a9ed4a29 SD	307	ASSERT_RTNL();
a9ed4a29 SD	308
1da177e4 LT	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
d8d1f30b	331	dst_hold(&aca->aca_rt->dst);
84f59370	332	ip6_del_rt(aca->aca_rt);
1da177e4 LT	333
	334	aca_put(aca);
	335	return 0;
	336	}
	337
6c555490	338	/* called with rtnl_lock() */
b71d1d42	339	static int ipv6_dev_ac_dec(struct net_device dev, const struct in6_addr addr)
1da177e4	340	{
bb69ae04 ED	341	struct inet6_dev *idev = __in6_dev_get(dev);
bb69ae04 ED	342
1da177e4 LT	343	if (idev == NULL)
1da177e4 LT	344	return -ENODEV;
bb69ae04	345	return __ipv6_dev_ac_dec(idev, addr);
1da177e4	346	}
1ab1457c	347
1da177e4 LT	348	/*
1da177e4 LT	349	* check if the interface has this anycast address
bb69ae04	350	* called with rcu_read_lock()
1da177e4	351	*/
a50feda5	352	static bool ipv6_chk_acast_dev(struct net_device dev, const struct in6_addr addr)
1da177e4 LT	353	{
	354	struct inet6_dev *idev;
	355	struct ifacaddr6 *aca;
	356
bb69ae04	357	idev = __in6_dev_get(dev);
1da177e4 LT	358	if (idev) {
	359	read_lock_bh(&idev->lock);
	360	for (aca = idev->ac_list; aca; aca = aca->aca_next)
	361	if (ipv6_addr_equal(&aca->aca_addr, addr))
	362	break;
	363	read_unlock_bh(&idev->lock);
cfcabdcc	364	return aca != NULL;
1da177e4	365	}
a50feda5	366	return false;
1da177e4 LT	367	}
	368
	369	/*
	370	* check if given interface (or any, if dev==0) has this anycast address
	371	*/
a50feda5 ED	372	bool ipv6_chk_acast_addr(struct net net, struct net_device dev,
a50feda5 ED	373	const struct in6_addr *addr)
1da177e4	374	{
a50feda5	375	bool found = false;
7562f876	376
c6d14c84	377	rcu_read_lock();
bb69ae04 ED	378	if (dev)
	379	found = ipv6_chk_acast_dev(dev, addr);
	380	else
	381	for_each_netdev_rcu(net, dev)
	382	if (ipv6_chk_acast_dev(dev, addr)) {
a50feda5	383	found = true;
bb69ae04 ED	384	break;
bb69ae04 ED	385	}
c6d14c84	386	rcu_read_unlock();
7562f876	387	return found;
1da177e4 LT	388	}
1da177e4 LT	389
7c90cc2d FLB	390	/* check if this anycast address is link-local on given interface or
	391	* is global
	392	*/
	393	bool ipv6_chk_acast_addr_src(struct net net, struct net_device dev,
	394	const struct in6_addr *addr)
	395	{
	396	return ipv6_chk_acast_addr(net,
	397	(ipv6_addr_type(addr) & IPV6_ADDR_LINKLOCAL ?
	398	dev : NULL),
	399	addr);
	400	}
1da177e4 LT	401
	402	#ifdef CONFIG_PROC_FS
	403	struct ac6_iter_state {
6ab57e7e	404	struct seq_net_private p;
1da177e4 LT	405	struct net_device *dev;
	406	struct inet6_dev *idev;
	407	};
	408
	409	#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
	410
	411	static inline struct ifacaddr6 ac6_get_first(struct seq_file seq)
	412	{
	413	struct ifacaddr6 *im = NULL;
	414	struct ac6_iter_state *state = ac6_seq_private(seq);
6ab57e7e	415	struct net *net = seq_file_net(seq);
1da177e4	416
7562f876	417	state->idev = NULL;
ce81b76a	418	for_each_netdev_rcu(net, state->dev) {
1da177e4	419	struct inet6_dev *idev;
ce81b76a	420	idev = __in6_dev_get(state->dev);
1da177e4 LT	421	if (!idev)
	422	continue;
	423	read_lock_bh(&idev->lock);
	424	im = idev->ac_list;
	425	if (im) {
	426	state->idev = idev;
	427	break;
	428	}
	429	read_unlock_bh(&idev->lock);
	430	}
	431	return im;
	432	}
	433
	434	static struct ifacaddr6 ac6_get_next(struct seq_file seq, struct ifacaddr6 *im)
	435	{
	436	struct ac6_iter_state *state = ac6_seq_private(seq);
	437
	438	im = im->aca_next;
	439	while (!im) {
ce81b76a	440	if (likely(state->idev != NULL))
1da177e4	441	read_unlock_bh(&state->idev->lock);
ce81b76a ED	442
ce81b76a ED	443	state->dev = next_net_device_rcu(state->dev);
1da177e4 LT	444	if (!state->dev) {
	445	state->idev = NULL;
	446	break;
	447	}
ce81b76a	448	state->idev = __in6_dev_get(state->dev);
1da177e4 LT	449	if (!state->idev)
	450	continue;
	451	read_lock_bh(&state->idev->lock);
	452	im = state->idev->ac_list;
	453	}
	454	return im;
	455	}
	456
	457	static struct ifacaddr6 ac6_get_idx(struct seq_file seq, loff_t pos)
	458	{
	459	struct ifacaddr6 *im = ac6_get_first(seq);
	460	if (im)
	461	while (pos && (im = ac6_get_next(seq, im)) != NULL)
	462	--pos;
	463	return pos ? NULL : im;
	464	}
	465
	466	static void ac6_seq_start(struct seq_file seq, loff_t *pos)
ce81b76a	467	__acquires(RCU)
1da177e4	468	{
ce81b76a	469	rcu_read_lock();
1da177e4 LT	470	return ac6_get_idx(seq, *pos);
	471	}
	472
	473	static void ac6_seq_next(struct seq_file seq, void v, loff_t pos)
	474	{
ce81b76a ED	475	struct ifacaddr6 *im = ac6_get_next(seq, v);
ce81b76a ED	476
1da177e4 LT	477	++*pos;
	478	return im;
	479	}
	480
	481	static void ac6_seq_stop(struct seq_file seq, void v)
ce81b76a	482	__releases(RCU)
1da177e4 LT	483	{
1da177e4 LT	484	struct ac6_iter_state *state = ac6_seq_private(seq);
ce81b76a	485
1da177e4 LT	486	if (likely(state->idev != NULL)) {
1da177e4 LT	487	read_unlock_bh(&state->idev->lock);
ce81b76a	488	state->idev = NULL;
1da177e4	489	}
ce81b76a	490	rcu_read_unlock();
1da177e4 LT	491	}
	492
	493	static int ac6_seq_show(struct seq_file seq, void v)
	494	{
	495	struct ifacaddr6 im = (struct ifacaddr6 )v;
	496	struct ac6_iter_state *state = ac6_seq_private(seq);
	497
4b7a4274	498	seq_printf(seq, "%-4d %-15s %pi6 %5d\n",
1da177e4	499	state->dev->ifindex, state->dev->name,
b071195d	500	&im->aca_addr, im->aca_users);
1da177e4 LT	501	return 0;
	502	}
	503
56b3d975	504	static const struct seq_operations ac6_seq_ops = {
1da177e4 LT	505	.start = ac6_seq_start,
	506	.next = ac6_seq_next,
	507	.stop = ac6_seq_stop,
	508	.show = ac6_seq_show,
	509	};
	510
	511	static int ac6_seq_open(struct inode inode, struct file file)
	512	{
6ab57e7e DL	513	return seq_open_net(inode, file, &ac6_seq_ops,
6ab57e7e DL	514	sizeof(struct ac6_iter_state));
1da177e4 LT	515	}
1da177e4 LT	516
9a32144e	517	static const struct file_operations ac6_seq_fops = {
1da177e4 LT	518	.owner = THIS_MODULE,
	519	.open = ac6_seq_open,
	520	.read = seq_read,
	521	.llseek = seq_lseek,
6ab57e7e	522	.release = seq_release_net,
1da177e4 LT	523	};
1da177e4 LT	524
2c8c1e72	525	int __net_init ac6_proc_init(struct net *net)
1da177e4	526	{
d4beaa66	527	if (!proc_create("anycast6", S_IRUGO, net->proc_net, &ac6_seq_fops))
1da177e4 LT	528	return -ENOMEM;
	529
	530	return 0;
	531	}
	532
6ab57e7e	533	void ac6_proc_exit(struct net *net)
1da177e4	534	{
ece31ffd	535	remove_proc_entry("anycast6", net->proc_net);
1da177e4 LT	536	}
	537	#endif
	538