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

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

#include <linux/capability.h>
#include <linux/config.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/sched.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/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;
	read_lock(&addrconf_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);
	}
	read_unlock(&addrconf_lock);
	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;
	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(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(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(IFF_UP, IFF_UP|IFF_LOOPBACK);
		}
	} else
		dev = dev_get_by_index(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;

	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(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;
	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(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 = kmalloc(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;
	}

	memset(aca, 0, sizeof(struct ifacaddr6));

	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, NULL, NULL, NULL))
		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, NULL, NULL, NULL))
		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 != 0;
	}
	return 0;
}

/*
 *	check if given interface (or any, if dev==0) has this anycast address
 */
int ipv6_chk_acast_addr(struct net_device *dev, struct in6_addr *addr)
{
	if (dev)
		return ipv6_chk_acast_dev(dev, addr);
	read_lock(&dev_base_lock);
	for (dev=dev_base; dev; dev=dev->next)
		if (ipv6_chk_acast_dev(dev, addr))
			break;
	read_unlock(&dev_base_lock);
	return dev != 0;
}


#ifdef CONFIG_PROC_FS
struct ac6_iter_state {
	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);

	for (state->dev = dev_base, state->idev = NULL;
	     state->dev;
	     state->dev = state->dev->next) {
		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);
			in6_dev_put(state->idev);
		}
		state->dev = state->dev->next;
		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)
{
	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)
{
	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 "
		   "%04x%04x%04x%04x%04x%04x%04x%04x "
		   "%5d\n",
		   state->dev->ifindex, state->dev->name,
		   NIP6(im->aca_addr),
		   im->aca_users);
	return 0;
}

static 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)
{
	struct seq_file *seq;
	int rc = -ENOMEM;
	struct ac6_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);

	if (!s)
		goto out;

	rc = seq_open(file, &ac6_seq_ops);
	if (rc)
		goto out_kfree;

	seq = file->private_data;
	seq->private = s;
	memset(s, 0, sizeof(*s));
out:
	return rc;
out_kfree:
	kfree(s);
	goto out;
}

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

int __init ac6_proc_init(void)
{
	if (!proc_net_fops_create("anycast6", S_IRUGO, &ac6_seq_fops))
		return -ENOMEM;

	return 0;
}

void ac6_proc_exit(void)
{
	proc_net_remove("anycast6");
}
#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Anycast support for IPv6
	3	* Linux INET6 implementation
	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/config.h>
	18	#include <linux/module.h>
	19	#include <linux/errno.h>
	20	#include <linux/types.h>
	21	#include <linux/random.h>
	22	#include <linux/string.h>
	23	#include <linux/socket.h>
	24	#include <linux/sockios.h>
	25	#include <linux/sched.h>
	26	#include <linux/net.h>
	27	#include <linux/in6.h>
	28	#include <linux/netdevice.h>
	29	#include <linux/if_arp.h>
	30	#include <linux/route.h>
	31	#include <linux/init.h>
	32	#include <linux/proc_fs.h>
	33	#include <linux/seq_file.h>
	34
	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
	47	static int ipv6_dev_ac_dec(struct net_device dev, struct in6_addr addr);
	48
	49	/* Big ac list lock for all the sockets */
	50	static DEFINE_RWLOCK(ipv6_sk_ac_lock);
	51
	52	static int
	53	ip6_onlink(struct in6_addr addr, struct net_device dev)
	54	{
	55	struct inet6_dev *idev;
	56	struct inet6_ifaddr *ifa;
	57	int onlink;
	58
	59	onlink = 0;
	60	read_lock(&addrconf_lock);
	61	idev = __in6_dev_get(dev);
	62	if (idev) {
	63	read_lock_bh(&idev->lock);
	64	for (ifa=idev->addr_list; ifa; ifa=ifa->if_next) {
	65	onlink = ipv6_prefix_equal(addr, &ifa->addr,
	66	ifa->prefix_len);
	67	if (onlink)
	68	break;
	69	}
	70	read_unlock_bh(&idev->lock);
	71	}
	72	read_unlock(&addrconf_lock);
	73	return onlink;
	74	}
	75
	76	/*
	77	* socket join an anycast group
	78	*/
	79
	80	int ipv6_sock_ac_join(struct sock sk, int ifindex, struct in6_addr addr)
81	{
82	struct ipv6_pinfo *np = inet6_sk(sk);
83	struct net_device *dev = NULL;
84	struct inet6_dev *idev;
85	struct ipv6_ac_socklist *pac;
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;
93	if (ipv6_chk_addr(addr, NULL, 0))
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
105	rt = rt6_lookup(addr, NULL, 0, 0);
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
116	dev = dev_get_by_flags(IFF_UP, IFF_UP\|IFF_LOOPBACK);
117	}
118	} else
119	dev = dev_get_by_index(ifindex);
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;
180
181	write_lock_bh(&ipv6_sk_ac_lock);
182	prev_pac = NULL;
183	for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
184	if ((ifindex == 0 \|\| pac->acl_ifindex == ifindex) &&
185	ipv6_addr_equal(&pac->acl_addr, addr))
186	break;
187	prev_pac = pac;
188	}
189	if (!pac) {
190	write_unlock_bh(&ipv6_sk_ac_lock);
191	return -ENOENT;
192	}
193	if (prev_pac)
194	prev_pac->acl_next = pac->acl_next;
195	else
196	np->ipv6_ac_list = pac->acl_next;
197
198	write_unlock_bh(&ipv6_sk_ac_lock);
199
200	dev = dev_get_by_index(pac->acl_ifindex);
201	if (dev) {
202	ipv6_dev_ac_dec(dev, &pac->acl_addr);
203	dev_put(dev);
204	}
205	sock_kfree_s(sk, pac, sizeof(*pac));
206	return 0;
207	}
208
209	void ipv6_sock_ac_close(struct sock *sk)
210	{
211	struct ipv6_pinfo *np = inet6_sk(sk);
212	struct net_device *dev = NULL;
213	struct ipv6_ac_socklist *pac;
214	int prev_index;
215
216	write_lock_bh(&ipv6_sk_ac_lock);
217	pac = np->ipv6_ac_list;
218	np->ipv6_ac_list = NULL;
219	write_unlock_bh(&ipv6_sk_ac_lock);
220
221	prev_index = 0;
222	while (pac) {
223	struct ipv6_ac_socklist *next = pac->acl_next;
224
225	if (pac->acl_ifindex != prev_index) {
226	if (dev)
227	dev_put(dev);
228	dev = dev_get_by_index(pac->acl_ifindex);
229	prev_index = pac->acl_ifindex;
230	}
231	if (dev)
232	ipv6_dev_ac_dec(dev, &pac->acl_addr);
233	sock_kfree_s(sk, pac, sizeof(*pac));
234	pac = next;
235	}
236	if (dev)
237	dev_put(dev);
238	}
239
240	#if 0
241	/* The function is not used, which is funny. Apparently, author
242	* supposed to use it to filter out datagrams inside udp/raw but forgot.
243	*
244	* It is OK, anycasts are not special comparing to delivery to unicasts.
245	*/
246
247	int inet6_ac_check(struct sock sk, struct in6_addr addr, int ifindex)
248	{
249	struct ipv6_ac_socklist *pac;
250	struct ipv6_pinfo *np = inet6_sk(sk);
251	int found;
252
253	found = 0;
254	read_lock(&ipv6_sk_ac_lock);
255	for (pac=np->ipv6_ac_list; pac; pac=pac->acl_next) {
256	if (ifindex && pac->acl_ifindex != ifindex)
257	continue;
258	found = ipv6_addr_equal(&pac->acl_addr, addr);
259	if (found)
260	break;
261	}
262	read_unlock(&ipv6_sk_ac_lock);
263
264	return found;
265	}
266
267	#endif
268
269	static void aca_put(struct ifacaddr6 *ac)
270	{
271	if (atomic_dec_and_test(&ac->aca_refcnt)) {
272	in6_dev_put(ac->aca_idev);
273	dst_release(&ac->aca_rt->u.dst);
274	kfree(ac);
275	}
276	}
277
278	/*
279	* device anycast group inc (add if not found)
280	*/
281	int ipv6_dev_ac_inc(struct net_device dev, struct in6_addr addr)
282	{
283	struct ifacaddr6 *aca;
284	struct inet6_dev *idev;
285	struct rt6_info *rt;
286	int err;
287
288	idev = in6_dev_get(dev);
289
290	if (idev == NULL)
291	return -EINVAL;
292
293	write_lock_bh(&idev->lock);
294	if (idev->dead) {
295	err = -ENODEV;
296	goto out;
297	}
298
299	for (aca = idev->ac_list; aca; aca = aca->aca_next) {
300	if (ipv6_addr_equal(&aca->aca_addr, addr)) {
301	aca->aca_users++;
302	err = 0;
303	goto out;
304	}
305	}
306
307	/*
308	* not found: create a new one.
309	*/
310
311	aca = kmalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
312
313	if (aca == NULL) {
314	err = -ENOMEM;
315	goto out;
316	}
317
318	rt = addrconf_dst_alloc(idev, addr, 1);
319	if (IS_ERR(rt)) {
320	kfree(aca);
321	err = PTR_ERR(rt);
322	goto out;
323	}
324
325	memset(aca, 0, sizeof(struct ifacaddr6));
326
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);
0d51aa80	341	if (ip6_ins_rt(rt, NULL, NULL, NULL))
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);
0d51aa80	384	if (ip6_del_rt(aca->aca_rt, NULL, NULL, NULL))
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	}
	403
	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);
	420	return aca != 0;
	421	}
	422	return 0;
	423	}
	424
	425	/*
	426	* check if given interface (or any, if dev==0) has this anycast address
	427	*/
	428	int ipv6_chk_acast_addr(struct net_device dev, struct in6_addr addr)
	429	{
	430	if (dev)
	431	return ipv6_chk_acast_dev(dev, addr);
	432	read_lock(&dev_base_lock);
	433	for (dev=dev_base; dev; dev=dev->next)
	434	if (ipv6_chk_acast_dev(dev, addr))
	435	break;
	436	read_unlock(&dev_base_lock);
	437	return dev != 0;
	438	}
	439
	440
	441	#ifdef CONFIG_PROC_FS
	442	struct ac6_iter_state {
	443	struct net_device *dev;
	444	struct inet6_dev *idev;
	445	};
	446
	447	#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
	448
449	static inline struct ifacaddr6 ac6_get_first(struct seq_file seq)
450	{
451	struct ifacaddr6 *im = NULL;
452	struct ac6_iter_state *state = ac6_seq_private(seq);
453
454	for (state->dev = dev_base, state->idev = NULL;
455	state->dev;
456	state->dev = state->dev->next) {
457	struct inet6_dev *idev;
458	idev = in6_dev_get(state->dev);
459	if (!idev)
460	continue;
461	read_lock_bh(&idev->lock);
462	im = idev->ac_list;
463	if (im) {
464	state->idev = idev;
465	break;
466	}
467	read_unlock_bh(&idev->lock);
468	}
469	return im;
470	}
471
472	static struct ifacaddr6 ac6_get_next(struct seq_file seq, struct ifacaddr6 *im)
473	{
474	struct ac6_iter_state *state = ac6_seq_private(seq);
475
476	im = im->aca_next;
477	while (!im) {
478	if (likely(state->idev != NULL)) {
479	read_unlock_bh(&state->idev->lock);
480	in6_dev_put(state->idev);
481	}
482	state->dev = state->dev->next;
483	if (!state->dev) {
484	state->idev = NULL;
485	break;
486	}
487	state->idev = in6_dev_get(state->dev);
488	if (!state->idev)
489	continue;
490	read_lock_bh(&state->idev->lock);
491	im = state->idev->ac_list;
492	}
493	return im;
494	}
495
496	static struct ifacaddr6 ac6_get_idx(struct seq_file seq, loff_t pos)
497	{
498	struct ifacaddr6 *im = ac6_get_first(seq);
499	if (im)
500	while (pos && (im = ac6_get_next(seq, im)) != NULL)
501	--pos;
502	return pos ? NULL : im;
503	}
504
505	static void ac6_seq_start(struct seq_file seq, loff_t *pos)
506	{
507	read_lock(&dev_base_lock);
508	return ac6_get_idx(seq, *pos);
509	}
510
511	static void ac6_seq_next(struct seq_file seq, void v, loff_t pos)
512	{
513	struct ifacaddr6 *im;
514	im = ac6_get_next(seq, v);
515	++*pos;
516	return im;
517	}
518
519	static void ac6_seq_stop(struct seq_file seq, void v)
520	{
521	struct ac6_iter_state *state = ac6_seq_private(seq);
522	if (likely(state->idev != NULL)) {
523	read_unlock_bh(&state->idev->lock);
524	in6_dev_put(state->idev);
525	}
526	read_unlock(&dev_base_lock);
527	}
528
529	static int ac6_seq_show(struct seq_file seq, void v)
530	{
531	struct ifacaddr6 im = (struct ifacaddr6 )v;
532	struct ac6_iter_state *state = ac6_seq_private(seq);
533
534	seq_printf(seq,
535	"%-4d %-15s "
536	"%04x%04x%04x%04x%04x%04x%04x%04x "
537	"%5d\n",
538	state->dev->ifindex, state->dev->name,
539	NIP6(im->aca_addr),
540	im->aca_users);
541	return 0;
542	}
543
544	static struct seq_operations ac6_seq_ops = {
545	.start = ac6_seq_start,
546	.next = ac6_seq_next,
547	.stop = ac6_seq_stop,
548	.show = ac6_seq_show,
549	};
550
551	static int ac6_seq_open(struct inode inode, struct file file)
552	{
553	struct seq_file *seq;
554	int rc = -ENOMEM;
555	struct ac6_iter_state s = kmalloc(sizeof(s), GFP_KERNEL);
556
557	if (!s)
558	goto out;
559
560	rc = seq_open(file, &ac6_seq_ops);
561	if (rc)
562	goto out_kfree;
563
564	seq = file->private_data;
565	seq->private = s;
566	memset(s, 0, sizeof(*s));
567	out:
568	return rc;
569	out_kfree:
570	kfree(s);
571	goto out;
572	}
573
574	static struct file_operations ac6_seq_fops = {
575	.owner = THIS_MODULE,
576	.open = ac6_seq_open,
577	.read = seq_read,
578	.llseek = seq_lseek,
579	.release = seq_release_private,
580	};
581
582	int __init ac6_proc_init(void)
583	{
584	if (!proc_net_fops_create("anycast6", S_IRUGO, &ac6_seq_fops))
585	return -ENOMEM;
586
587	return 0;
588	}
589
590	void ac6_proc_exit(void)
591	{
592	proc_net_remove("anycast6");
593	}
594	#endif
595