[linux-2.6-block.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);

/*
 *	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;

	ASSERT_RTNL();

	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
		return -EPERM;
	if (ipv6_addr_is_multicast(addr))
		return -EINVAL;

	if (ifindex)
		dev = __dev_get_by_index(net, ifindex);

	if (ipv6_chk_addr_and_flags(net, addr, dev, true, 0, IFA_F_TENTATIVE))
		return -EINVAL;

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

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

		rt = rt6_lookup(net, addr, NULL, 0, NULL, 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);
		}
	}

	if (!dev) {
		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(idev, addr);
	if (!err) {
		pac->acl_next = np->ipv6_ac_list;
		np->ipv6_ac_list = pac;
		pac = NULL;
	}

error:
	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);

	ASSERT_RTNL();

	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)
		return -ENOENT;
	if (prev_pac)
		prev_pac->acl_next = pac->acl_next;
	else
		np->ipv6_ac_list = pac->acl_next;

	dev = __dev_get_by_index(net, pac->acl_ifindex);
	if (dev)
		ipv6_dev_ac_dec(dev, &pac->acl_addr);

	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;

	rtnl_lock();
	pac = np->ipv6_ac_list;
	np->ipv6_ac_list = NULL;

	prev_index = 0;
	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_get(struct ifacaddr6 *aca)
{
	refcount_inc(&aca->aca_refcnt);
}

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

static struct ifacaddr6 *aca_alloc(struct rt6_info *rt,
				   const struct in6_addr *addr)
{
	struct inet6_dev *idev = rt->rt6i_idev;
	struct ifacaddr6 *aca;

	aca = kzalloc(sizeof(*aca), GFP_ATOMIC);
	if (!aca)
		return NULL;

	aca->aca_addr = *addr;
	in6_dev_hold(idev);
	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;
	refcount_set(&aca->aca_refcnt, 1);

	return aca;
}

/*
 *	device anycast group inc (add if not found)
 */
int __ipv6_dev_ac_inc(struct inet6_dev *idev, const struct in6_addr *addr)
{
	struct ifacaddr6 *aca;
	struct rt6_info *rt;
	int err;

	ASSERT_RTNL();

	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;
		}
	}

	rt = addrconf_dst_alloc(idev, addr, true);
	if (IS_ERR(rt)) {
		err = PTR_ERR(rt);
		goto out;
	}
	aca = aca_alloc(rt, addr);
	if (!aca) {
		ip6_rt_put(rt);
		err = -ENOMEM;
		goto out;
	}

	aca->aca_next = idev->ac_list;
	idev->ac_list = aca;

	/* Hold this for addrconf_join_solict() below before we unlock,
	 * it is already exposed via idev->ac_list.
	 */
	aca_get(aca);
	write_unlock_bh(&idev->lock);

	ip6_ins_rt(rt);

	addrconf_join_solict(idev->dev, &aca->aca_addr);

	aca_put(aca);
	return 0;
out:
	write_unlock_bh(&idev->lock);
	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)
		return -ENODEV;
	return __ipv6_dev_ac_dec(idev, addr);
}

void ipv6_ac_destroy_dev(struct inet6_dev *idev)
{
	struct ifacaddr6 *aca;

	write_lock_bh(&idev->lock);
	while ((aca = idev->ac_list) != NULL) {
		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);

		write_lock_bh(&idev->lock);
	}
	write_unlock_bh(&idev->lock);
}

/*
 *	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 = {
	.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", 0444, 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	48
1da177e4 LT	49	/*
	50	* socket join an anycast group
	51	*/
	52
b71d1d42	53	int ipv6_sock_ac_join(struct sock sk, int ifindex, const struct in6_addr addr)
1da177e4 LT	54	{
	55	struct ipv6_pinfo *np = inet6_sk(sk);
	56	struct net_device *dev = NULL;
	57	struct inet6_dev *idev;
	58	struct ipv6_ac_socklist *pac;
6ab57e7e	59	struct net *net = sock_net(sk);
53b7997f	60	int ishost = !net->ipv6.devconf_all->forwarding;
1da177e4 LT	61	int err = 0;
1da177e4 LT	62
c4a6853d MRL	63	ASSERT_RTNL();
c4a6853d MRL	64
af31f412	65	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1da177e4 LT	66	return -EPERM;
	67	if (ipv6_addr_is_multicast(addr))
	68	return -EINVAL;
232378e8 DA	69
	70	if (ifindex)
	71	dev = __dev_get_by_index(net, ifindex);
	72
	73	if (ipv6_chk_addr_and_flags(net, addr, dev, true, 0, IFA_F_TENTATIVE))
1da177e4 LT	74	return -EINVAL;
	75
	76	pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
63159f29	77	if (!pac)
1da177e4 LT	78	return -ENOMEM;
1da177e4 LT	79	pac->acl_next = NULL;
4e3fd7a0	80	pac->acl_addr = *addr;
1da177e4 LT	81
	82	if (ifindex == 0) {
	83	struct rt6_info *rt;
	84
b75cc8f9	85	rt = rt6_lookup(net, addr, NULL, 0, NULL, 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 */
6c555490 WC	94	dev = __dev_get_by_flags(net, IFF_UP,
6c555490 WC	95	IFF_UP \| IFF_LOOPBACK);
1da177e4	96	}
232378e8	97	}
1da177e4	98
63159f29	99	if (!dev) {
1da177e4	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	}
1da177e4 LT	128
013b4d90	129	err = __ipv6_dev_ac_inc(idev, addr);
bb69ae04	130	if (!err) {
bb69ae04 ED	131	pac->acl_next = np->ipv6_ac_list;
bb69ae04 ED	132	np->ipv6_ac_list = pac;
bb69ae04 ED	133	pac = NULL;
bb69ae04 ED	134	}
1da177e4	135
bb69ae04	136	error:
bb69ae04 ED	137	if (pac)
bb69ae04 ED	138	sock_kfree_s(sk, pac, sizeof(*pac));
1da177e4 LT	139	return err;
	140	}
	141
	142	/*
	143	* socket leave an anycast group
	144	*/
b71d1d42	145	int ipv6_sock_ac_drop(struct sock sk, int ifindex, const struct in6_addr addr)
1da177e4 LT	146	{
	147	struct ipv6_pinfo *np = inet6_sk(sk);
	148	struct net_device *dev;
	149	struct ipv6_ac_socklist pac, prev_pac;
6ab57e7e	150	struct net *net = sock_net(sk);
1da177e4	151
c4a6853d MRL	152	ASSERT_RTNL();
c4a6853d MRL	153
1da177e4 LT	154	prev_pac = NULL;
	155	for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
	156	if ((ifindex == 0 \|\| pac->acl_ifindex == ifindex) &&
	157	ipv6_addr_equal(&pac->acl_addr, addr))
	158	break;
	159	prev_pac = pac;
	160	}
c4a6853d	161	if (!pac)
1da177e4	162	return -ENOENT;
1da177e4 LT	163	if (prev_pac)
	164	prev_pac->acl_next = pac->acl_next;
	165	else
	166	np->ipv6_ac_list = pac->acl_next;
	167
6c555490	168	dev = __dev_get_by_index(net, pac->acl_ifindex);
bb69ae04	169	if (dev)
1da177e4	170	ipv6_dev_ac_dec(dev, &pac->acl_addr);
bb69ae04	171
1da177e4 LT	172	sock_kfree_s(sk, pac, sizeof(*pac));
	173	return 0;
	174	}
	175
	176	void ipv6_sock_ac_close(struct sock *sk)
	177	{
	178	struct ipv6_pinfo *np = inet6_sk(sk);
	179	struct net_device *dev = NULL;
	180	struct ipv6_ac_socklist *pac;
6ab57e7e	181	struct net *net = sock_net(sk);
1da177e4 LT	182	int prev_index;
1da177e4 LT	183
0e1efe9d ED	184	if (!np->ipv6_ac_list)
	185	return;
	186
b03a9c04	187	rtnl_lock();
1da177e4 LT	188	pac = np->ipv6_ac_list;
1da177e4 LT	189	np->ipv6_ac_list = NULL;
1da177e4 LT	190
	191	prev_index = 0;
	192	while (pac) {
	193	struct ipv6_ac_socklist *next = pac->acl_next;
	194
	195	if (pac->acl_ifindex != prev_index) {
6c555490	196	dev = __dev_get_by_index(net, pac->acl_ifindex);
1da177e4 LT	197	prev_index = pac->acl_ifindex;
	198	}
	199	if (dev)
	200	ipv6_dev_ac_dec(dev, &pac->acl_addr);
	201	sock_kfree_s(sk, pac, sizeof(*pac));
	202	pac = next;
	203	}
a9ed4a29	204	rtnl_unlock();
1da177e4 LT	205	}
1da177e4 LT	206
83aa29ee WC	207	static void aca_get(struct ifacaddr6 *aca)
83aa29ee WC	208	{
affa78bc	209	refcount_inc(&aca->aca_refcnt);
83aa29ee WC	210	}
83aa29ee WC	211
1da177e4 LT	212	static void aca_put(struct ifacaddr6 *ac)
1da177e4 LT	213	{
affa78bc	214	if (refcount_dec_and_test(&ac->aca_refcnt)) {
1da177e4	215	in6_dev_put(ac->aca_idev);
d8d1f30b	216	dst_release(&ac->aca_rt->dst);
1da177e4 LT	217	kfree(ac);
	218	}
	219	}
	220
83aa29ee WC	221	static struct ifacaddr6 aca_alloc(struct rt6_info rt,
	222	const struct in6_addr *addr)
	223	{
	224	struct inet6_dev *idev = rt->rt6i_idev;
	225	struct ifacaddr6 *aca;
	226
	227	aca = kzalloc(sizeof(*aca), GFP_ATOMIC);
63159f29	228	if (!aca)
83aa29ee WC	229	return NULL;
	230
	231	aca->aca_addr = *addr;
	232	in6_dev_hold(idev);
	233	aca->aca_idev = idev;
	234	aca->aca_rt = rt;
	235	aca->aca_users = 1;
	236	/* aca_tstamp should be updated upon changes */
	237	aca->aca_cstamp = aca->aca_tstamp = jiffies;
affa78bc	238	refcount_set(&aca->aca_refcnt, 1);
83aa29ee WC	239
	240	return aca;
	241	}
	242
1da177e4 LT	243	/*
	244	* device anycast group inc (add if not found)
	245	*/
013b4d90	246	int __ipv6_dev_ac_inc(struct inet6_dev idev, const struct in6_addr addr)
1da177e4 LT	247	{
1da177e4 LT	248	struct ifacaddr6 *aca;
1da177e4 LT	249	struct rt6_info *rt;
	250	int err;
	251
a9ed4a29 SD	252	ASSERT_RTNL();
a9ed4a29 SD	253
1da177e4 LT	254	write_lock_bh(&idev->lock);
	255	if (idev->dead) {
	256	err = -ENODEV;
	257	goto out;
	258	}
	259
	260	for (aca = idev->ac_list; aca; aca = aca->aca_next) {
	261	if (ipv6_addr_equal(&aca->aca_addr, addr)) {
	262	aca->aca_users++;
	263	err = 0;
	264	goto out;
	265	}
	266	}
	267
8f031519	268	rt = addrconf_dst_alloc(idev, addr, true);
1da177e4	269	if (IS_ERR(rt)) {
1da177e4 LT	270	err = PTR_ERR(rt);
	271	goto out;
	272	}
83aa29ee	273	aca = aca_alloc(rt, addr);
63159f29	274	if (!aca) {
83aa29ee WC	275	ip6_rt_put(rt);
	276	err = -ENOMEM;
	277	goto out;
	278	}
1da177e4 LT	279
	280	aca->aca_next = idev->ac_list;
	281	idev->ac_list = aca;
83aa29ee WC	282
	283	/* Hold this for addrconf_join_solict() below before we unlock,
	284	* it is already exposed via idev->ac_list.
	285	*/
	286	aca_get(aca);
1da177e4 LT	287	write_unlock_bh(&idev->lock);
1da177e4 LT	288
84f59370	289	ip6_ins_rt(rt);
1da177e4	290
013b4d90	291	addrconf_join_solict(idev->dev, &aca->aca_addr);
1da177e4 LT	292
	293	aca_put(aca);
	294	return 0;
	295	out:
	296	write_unlock_bh(&idev->lock);
1da177e4 LT	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
63159f29	343	if (!idev)
1da177e4	344	return -ENODEV;
bb69ae04	345	return __ipv6_dev_ac_dec(idev, addr);
1da177e4	346	}
1ab1457c	347
381f4dca SD	348	void ipv6_ac_destroy_dev(struct inet6_dev *idev)
	349	{
	350	struct ifacaddr6 *aca;
	351
	352	write_lock_bh(&idev->lock);
	353	while ((aca = idev->ac_list) != NULL) {
	354	idev->ac_list = aca->aca_next;
	355	write_unlock_bh(&idev->lock);
	356
	357	addrconf_leave_solict(idev, &aca->aca_addr);
	358
	359	dst_hold(&aca->aca_rt->dst);
	360	ip6_del_rt(aca->aca_rt);
	361
	362	aca_put(aca);
	363
	364	write_lock_bh(&idev->lock);
	365	}
	366	write_unlock_bh(&idev->lock);
	367	}
	368
1da177e4 LT	369	/*
1da177e4 LT	370	* check if the interface has this anycast address
bb69ae04	371	* called with rcu_read_lock()
1da177e4	372	*/
a50feda5	373	static bool ipv6_chk_acast_dev(struct net_device dev, const struct in6_addr addr)
1da177e4 LT	374	{
	375	struct inet6_dev *idev;
	376	struct ifacaddr6 *aca;
	377
bb69ae04	378	idev = __in6_dev_get(dev);
1da177e4 LT	379	if (idev) {
	380	read_lock_bh(&idev->lock);
	381	for (aca = idev->ac_list; aca; aca = aca->aca_next)
	382	if (ipv6_addr_equal(&aca->aca_addr, addr))
	383	break;
	384	read_unlock_bh(&idev->lock);
cfcabdcc	385	return aca != NULL;
1da177e4	386	}
a50feda5	387	return false;
1da177e4 LT	388	}
	389
	390	/*
	391	* check if given interface (or any, if dev==0) has this anycast address
	392	*/
a50feda5 ED	393	bool ipv6_chk_acast_addr(struct net net, struct net_device dev,
a50feda5 ED	394	const struct in6_addr *addr)
1da177e4	395	{
a50feda5	396	bool found = false;
7562f876	397
c6d14c84	398	rcu_read_lock();
bb69ae04 ED	399	if (dev)
	400	found = ipv6_chk_acast_dev(dev, addr);
	401	else
	402	for_each_netdev_rcu(net, dev)
	403	if (ipv6_chk_acast_dev(dev, addr)) {
a50feda5	404	found = true;
bb69ae04 ED	405	break;
bb69ae04 ED	406	}
c6d14c84	407	rcu_read_unlock();
7562f876	408	return found;
1da177e4 LT	409	}
1da177e4 LT	410
7c90cc2d FLB	411	/* check if this anycast address is link-local on given interface or
	412	* is global
	413	*/
	414	bool ipv6_chk_acast_addr_src(struct net net, struct net_device dev,
	415	const struct in6_addr *addr)
	416	{
	417	return ipv6_chk_acast_addr(net,
	418	(ipv6_addr_type(addr) & IPV6_ADDR_LINKLOCAL ?
	419	dev : NULL),
	420	addr);
	421	}
1da177e4 LT	422
	423	#ifdef CONFIG_PROC_FS
	424	struct ac6_iter_state {
6ab57e7e	425	struct seq_net_private p;
1da177e4 LT	426	struct net_device *dev;
	427	struct inet6_dev *idev;
	428	};
	429
	430	#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
	431
	432	static inline struct ifacaddr6 ac6_get_first(struct seq_file seq)
	433	{
	434	struct ifacaddr6 *im = NULL;
	435	struct ac6_iter_state *state = ac6_seq_private(seq);
6ab57e7e	436	struct net *net = seq_file_net(seq);
1da177e4	437
7562f876	438	state->idev = NULL;
ce81b76a	439	for_each_netdev_rcu(net, state->dev) {
1da177e4	440	struct inet6_dev *idev;
ce81b76a	441	idev = __in6_dev_get(state->dev);
1da177e4 LT	442	if (!idev)
	443	continue;
	444	read_lock_bh(&idev->lock);
	445	im = idev->ac_list;
	446	if (im) {
	447	state->idev = idev;
	448	break;
	449	}
	450	read_unlock_bh(&idev->lock);
	451	}
	452	return im;
	453	}
	454
	455	static struct ifacaddr6 ac6_get_next(struct seq_file seq, struct ifacaddr6 *im)
	456	{
	457	struct ac6_iter_state *state = ac6_seq_private(seq);
	458
	459	im = im->aca_next;
	460	while (!im) {
ce81b76a	461	if (likely(state->idev != NULL))
1da177e4	462	read_unlock_bh(&state->idev->lock);
ce81b76a ED	463
ce81b76a ED	464	state->dev = next_net_device_rcu(state->dev);
1da177e4 LT	465	if (!state->dev) {
	466	state->idev = NULL;
	467	break;
	468	}
ce81b76a	469	state->idev = __in6_dev_get(state->dev);
1da177e4 LT	470	if (!state->idev)
	471	continue;
	472	read_lock_bh(&state->idev->lock);
	473	im = state->idev->ac_list;
	474	}
	475	return im;
	476	}
	477
	478	static struct ifacaddr6 ac6_get_idx(struct seq_file seq, loff_t pos)
	479	{
	480	struct ifacaddr6 *im = ac6_get_first(seq);
	481	if (im)
	482	while (pos && (im = ac6_get_next(seq, im)) != NULL)
	483	--pos;
	484	return pos ? NULL : im;
	485	}
	486
	487	static void ac6_seq_start(struct seq_file seq, loff_t *pos)
ce81b76a	488	__acquires(RCU)
1da177e4	489	{
ce81b76a	490	rcu_read_lock();
1da177e4 LT	491	return ac6_get_idx(seq, *pos);
	492	}
	493
	494	static void ac6_seq_next(struct seq_file seq, void v, loff_t pos)
	495	{
ce81b76a ED	496	struct ifacaddr6 *im = ac6_get_next(seq, v);
ce81b76a ED	497
1da177e4 LT	498	++*pos;
	499	return im;
	500	}
	501
	502	static void ac6_seq_stop(struct seq_file seq, void v)
ce81b76a	503	__releases(RCU)
1da177e4 LT	504	{
1da177e4 LT	505	struct ac6_iter_state *state = ac6_seq_private(seq);
ce81b76a	506
1da177e4 LT	507	if (likely(state->idev != NULL)) {
1da177e4 LT	508	read_unlock_bh(&state->idev->lock);
ce81b76a	509	state->idev = NULL;
1da177e4	510	}
ce81b76a	511	rcu_read_unlock();
1da177e4 LT	512	}
	513
	514	static int ac6_seq_show(struct seq_file seq, void v)
	515	{
	516	struct ifacaddr6 im = (struct ifacaddr6 )v;
	517	struct ac6_iter_state *state = ac6_seq_private(seq);
	518
4b7a4274	519	seq_printf(seq, "%-4d %-15s %pi6 %5d\n",
1da177e4	520	state->dev->ifindex, state->dev->name,
b071195d	521	&im->aca_addr, im->aca_users);
1da177e4 LT	522	return 0;
	523	}
	524
56b3d975	525	static const struct seq_operations ac6_seq_ops = {
1da177e4 LT	526	.start = ac6_seq_start,
	527	.next = ac6_seq_next,
	528	.stop = ac6_seq_stop,
	529	.show = ac6_seq_show,
	530	};
	531
	532	static int ac6_seq_open(struct inode inode, struct file file)
	533	{
6ab57e7e DL	534	return seq_open_net(inode, file, &ac6_seq_ops,
6ab57e7e DL	535	sizeof(struct ac6_iter_state));
1da177e4 LT	536	}
1da177e4 LT	537
9a32144e	538	static const struct file_operations ac6_seq_fops = {
1da177e4 LT	539	.open = ac6_seq_open,
	540	.read = seq_read,
	541	.llseek = seq_lseek,
6ab57e7e	542	.release = seq_release_net,
1da177e4 LT	543	};
1da177e4 LT	544
2c8c1e72	545	int __net_init ac6_proc_init(struct net *net)
1da177e4	546	{
d6444062	547	if (!proc_create("anycast6", 0444, net->proc_net, &ac6_seq_fops))
1da177e4 LT	548	return -ENOMEM;
	549
	550	return 0;
	551	}
	552
6ab57e7e	553	void ac6_proc_exit(struct net *net)
1da177e4	554	{
ece31ffd	555	remove_proc_entry("anycast6", net->proc_net);
1da177e4 LT	556	}
1da177e4 LT	557	#endif