[deliverable/linux.git] / net / netfilter / nfnetlink_cttimeout.c

/*
 * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
 * (C) 2012 by Vyatta Inc. <http://www.vyatta.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation (or any later at your option).
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/rculist.h>
#include <linux/rculist_nulls.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/security.h>
#include <linux/skbuff.h>
#include <linux/errno.h>
#include <linux/netlink.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/slab.h>

#include <linux/netfilter.h>
#include <net/netlink.h>
#include <net/sock.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_l3proto.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_tuple.h>
#include <net/netfilter/nf_conntrack_timeout.h>

#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_cttimeout.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning");

static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = {
	[CTA_TIMEOUT_NAME]	= { .type = NLA_NUL_STRING,
				    .len  = CTNL_TIMEOUT_NAME_MAX - 1},
	[CTA_TIMEOUT_L3PROTO]	= { .type = NLA_U16 },
	[CTA_TIMEOUT_L4PROTO]	= { .type = NLA_U8 },
	[CTA_TIMEOUT_DATA]	= { .type = NLA_NESTED },
};

static int
ctnl_timeout_parse_policy(void *timeouts, struct nf_conntrack_l4proto *l4proto,
			  struct net *net, const struct nlattr *attr)
{
	int ret = 0;

	if (likely(l4proto->ctnl_timeout.nlattr_to_obj)) {
		struct nlattr *tb[l4proto->ctnl_timeout.nlattr_max+1];

		ret = nla_parse_nested(tb, l4proto->ctnl_timeout.nlattr_max,
				       attr, l4proto->ctnl_timeout.nla_policy);
		if (ret < 0)
			return ret;

		ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeouts);
	}
	return ret;
}

static int cttimeout_new_timeout(struct net *net, struct sock *ctnl,
				 struct sk_buff *skb,
				 const struct nlmsghdr *nlh,
				 const struct nlattr * const cda[])
{
	__u16 l3num;
	__u8 l4num;
	struct nf_conntrack_l4proto *l4proto;
	struct ctnl_timeout *timeout, *matching = NULL;
	char *name;
	int ret;

	if (!cda[CTA_TIMEOUT_NAME] ||
	    !cda[CTA_TIMEOUT_L3PROTO] ||
	    !cda[CTA_TIMEOUT_L4PROTO] ||
	    !cda[CTA_TIMEOUT_DATA])
		return -EINVAL;

	name = nla_data(cda[CTA_TIMEOUT_NAME]);
	l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
	l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);

	list_for_each_entry(timeout, &net->nfct_timeout_list, head) {
		if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
			continue;

		if (nlh->nlmsg_flags & NLM_F_EXCL)
			return -EEXIST;

		matching = timeout;
		break;
	}

	l4proto = nf_ct_l4proto_find_get(l3num, l4num);

	/* This protocol is not supportted, skip. */
	if (l4proto->l4proto != l4num) {
		ret = -EOPNOTSUPP;
		goto err_proto_put;
	}

	if (matching) {
		if (nlh->nlmsg_flags & NLM_F_REPLACE) {
			/* You cannot replace one timeout policy by another of
			 * different kind, sorry.
			 */
			if (matching->l3num != l3num ||
			    matching->l4proto->l4proto != l4num) {
				ret = -EINVAL;
				goto err_proto_put;
			}

			ret = ctnl_timeout_parse_policy(&matching->data,
							l4proto, net,
							cda[CTA_TIMEOUT_DATA]);
			return ret;
		}
		ret = -EBUSY;
		goto err_proto_put;
	}

	timeout = kzalloc(sizeof(struct ctnl_timeout) +
			  l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
	if (timeout == NULL) {
		ret = -ENOMEM;
		goto err_proto_put;
	}

	ret = ctnl_timeout_parse_policy(&timeout->data, l4proto, net,
					cda[CTA_TIMEOUT_DATA]);
	if (ret < 0)
		goto err;

	strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
	timeout->l3num = l3num;
	timeout->l4proto = l4proto;
	atomic_set(&timeout->refcnt, 1);
	list_add_tail_rcu(&timeout->head, &net->nfct_timeout_list);

	return 0;
err:
	kfree(timeout);
err_proto_put:
	nf_ct_l4proto_put(l4proto);
	return ret;
}

static int
ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
		       int event, struct ctnl_timeout *timeout)
{
	struct nlmsghdr *nlh;
	struct nfgenmsg *nfmsg;
	unsigned int flags = portid ? NLM_F_MULTI : 0;
	struct nf_conntrack_l4proto *l4proto = timeout->l4proto;

	event |= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8;
	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
	if (nlh == NULL)
		goto nlmsg_failure;

	nfmsg = nlmsg_data(nlh);
	nfmsg->nfgen_family = AF_UNSPEC;
	nfmsg->version = NFNETLINK_V0;
	nfmsg->res_id = 0;

	if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) ||
	    nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(timeout->l3num)) ||
	    nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, timeout->l4proto->l4proto) ||
	    nla_put_be32(skb, CTA_TIMEOUT_USE,
			 htonl(atomic_read(&timeout->refcnt))))
		goto nla_put_failure;

	if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
		struct nlattr *nest_parms;
		int ret;

		nest_parms = nla_nest_start(skb,
					    CTA_TIMEOUT_DATA | NLA_F_NESTED);
		if (!nest_parms)
			goto nla_put_failure;

		ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->data);
		if (ret < 0)
			goto nla_put_failure;

		nla_nest_end(skb, nest_parms);
	}

	nlmsg_end(skb, nlh);
	return skb->len;

nlmsg_failure:
nla_put_failure:
	nlmsg_cancel(skb, nlh);
	return -1;
}

static int
ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
	struct net *net = sock_net(skb->sk);
	struct ctnl_timeout *cur, *last;

	if (cb->args[2])
		return 0;

	last = (struct ctnl_timeout *)cb->args[1];
	if (cb->args[1])
		cb->args[1] = 0;

	rcu_read_lock();
	list_for_each_entry_rcu(cur, &net->nfct_timeout_list, head) {
		if (last) {
			if (cur != last)
				continue;

			last = NULL;
		}
		if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
					   cb->nlh->nlmsg_seq,
					   NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
					   IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
			cb->args[1] = (unsigned long)cur;
			break;
		}
	}
	if (!cb->args[1])
		cb->args[2] = 1;
	rcu_read_unlock();
	return skb->len;
}

static int cttimeout_get_timeout(struct net *net, struct sock *ctnl,
				 struct sk_buff *skb,
				 const struct nlmsghdr *nlh,
				 const struct nlattr * const cda[])
{
	int ret = -ENOENT;
	char *name;
	struct ctnl_timeout *cur;

	if (nlh->nlmsg_flags & NLM_F_DUMP) {
		struct netlink_dump_control c = {
			.dump = ctnl_timeout_dump,
		};
		return netlink_dump_start(ctnl, skb, nlh, &c);
	}

	if (!cda[CTA_TIMEOUT_NAME])
		return -EINVAL;
	name = nla_data(cda[CTA_TIMEOUT_NAME]);

	list_for_each_entry(cur, &net->nfct_timeout_list, head) {
		struct sk_buff *skb2;

		if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
			continue;

		skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
		if (skb2 == NULL) {
			ret = -ENOMEM;
			break;
		}

		ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
					     nlh->nlmsg_seq,
					     NFNL_MSG_TYPE(nlh->nlmsg_type),
					     IPCTNL_MSG_TIMEOUT_NEW, cur);
		if (ret <= 0) {
			kfree_skb(skb2);
			break;
		}
		ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
					MSG_DONTWAIT);
		if (ret > 0)
			ret = 0;

		/* this avoids a loop in nfnetlink. */
		return ret == -EAGAIN ? -ENOBUFS : ret;
	}
	return ret;
}

static void untimeout(struct nf_conntrack_tuple_hash *i,
		      struct ctnl_timeout *timeout)
{
	struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(i);
	struct nf_conn_timeout *timeout_ext = nf_ct_timeout_find(ct);

	if (timeout_ext && (!timeout || timeout_ext->timeout == timeout))
		RCU_INIT_POINTER(timeout_ext->timeout, NULL);
}

static void ctnl_untimeout(struct net *net, struct ctnl_timeout *timeout)
{
	struct nf_conntrack_tuple_hash *h;
	const struct hlist_nulls_node *nn;
	unsigned int last_hsize;
	spinlock_t *lock;
	int i;

	local_bh_disable();
restart:
	last_hsize = nf_conntrack_htable_size;
	for (i = 0; i < last_hsize; i++) {
		lock = &nf_conntrack_locks[i % CONNTRACK_LOCKS];
		nf_conntrack_lock(lock);
		if (last_hsize != nf_conntrack_htable_size) {
			spin_unlock(lock);
			goto restart;
		}

		hlist_nulls_for_each_entry(h, nn, &nf_conntrack_hash[i], hnnode)
			untimeout(h, timeout);
		spin_unlock(lock);
	}
	local_bh_enable();
}

/* try to delete object, fail if it is still in use. */
static int ctnl_timeout_try_del(struct net *net, struct ctnl_timeout *timeout)
{
	int ret = 0;

	/* we want to avoid races with nf_ct_timeout_find_get. */
	if (atomic_dec_and_test(&timeout->refcnt)) {
		/* We are protected by nfnl mutex. */
		list_del_rcu(&timeout->head);
		nf_ct_l4proto_put(timeout->l4proto);
		ctnl_untimeout(net, timeout);
		kfree_rcu(timeout, rcu_head);
	} else {
		/* still in use, restore reference counter. */
		atomic_inc(&timeout->refcnt);
		ret = -EBUSY;
	}
	return ret;
}

static int cttimeout_del_timeout(struct net *net, struct sock *ctnl,
				 struct sk_buff *skb,
				 const struct nlmsghdr *nlh,
				 const struct nlattr * const cda[])
{
	struct ctnl_timeout *cur;
	int ret = -ENOENT;
	char *name;

	if (!cda[CTA_TIMEOUT_NAME]) {
		list_for_each_entry(cur, &net->nfct_timeout_list, head)
			ctnl_timeout_try_del(net, cur);

		return 0;
	}
	name = nla_data(cda[CTA_TIMEOUT_NAME]);

	list_for_each_entry(cur, &net->nfct_timeout_list, head) {
		if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
			continue;

		ret = ctnl_timeout_try_del(net, cur);
		if (ret < 0)
			return ret;

		break;
	}
	return ret;
}

static int cttimeout_default_set(struct net *net, struct sock *ctnl,
				 struct sk_buff *skb,
				 const struct nlmsghdr *nlh,
				 const struct nlattr * const cda[])
{
	__u16 l3num;
	__u8 l4num;
	struct nf_conntrack_l4proto *l4proto;
	unsigned int *timeouts;
	int ret;

	if (!cda[CTA_TIMEOUT_L3PROTO] ||
	    !cda[CTA_TIMEOUT_L4PROTO] ||
	    !cda[CTA_TIMEOUT_DATA])
		return -EINVAL;

	l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
	l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
	l4proto = nf_ct_l4proto_find_get(l3num, l4num);

	/* This protocol is not supported, skip. */
	if (l4proto->l4proto != l4num) {
		ret = -EOPNOTSUPP;
		goto err;
	}

	timeouts = l4proto->get_timeouts(net);

	ret = ctnl_timeout_parse_policy(timeouts, l4proto, net,
					cda[CTA_TIMEOUT_DATA]);
	if (ret < 0)
		goto err;

	nf_ct_l4proto_put(l4proto);
	return 0;
err:
	nf_ct_l4proto_put(l4proto);
	return ret;
}

static int
cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
			    u32 seq, u32 type, int event,
			    struct nf_conntrack_l4proto *l4proto)
{
	struct nlmsghdr *nlh;
	struct nfgenmsg *nfmsg;
	unsigned int flags = portid ? NLM_F_MULTI : 0;

	event |= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8;
	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
	if (nlh == NULL)
		goto nlmsg_failure;

	nfmsg = nlmsg_data(nlh);
	nfmsg->nfgen_family = AF_UNSPEC;
	nfmsg->version = NFNETLINK_V0;
	nfmsg->res_id = 0;

	if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l4proto->l3proto)) ||
	    nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
		goto nla_put_failure;

	if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
		struct nlattr *nest_parms;
		unsigned int *timeouts = l4proto->get_timeouts(net);
		int ret;

		nest_parms = nla_nest_start(skb,
					    CTA_TIMEOUT_DATA | NLA_F_NESTED);
		if (!nest_parms)
			goto nla_put_failure;

		ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, timeouts);
		if (ret < 0)
			goto nla_put_failure;

		nla_nest_end(skb, nest_parms);
	}

	nlmsg_end(skb, nlh);
	return skb->len;

nlmsg_failure:
nla_put_failure:
	nlmsg_cancel(skb, nlh);
	return -1;
}

static int cttimeout_default_get(struct net *net, struct sock *ctnl,
				 struct sk_buff *skb,
				 const struct nlmsghdr *nlh,
				 const struct nlattr * const cda[])
{
	__u16 l3num;
	__u8 l4num;
	struct nf_conntrack_l4proto *l4proto;
	struct sk_buff *skb2;
	int ret, err;

	if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
		return -EINVAL;

	l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
	l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
	l4proto = nf_ct_l4proto_find_get(l3num, l4num);

	/* This protocol is not supported, skip. */
	if (l4proto->l4proto != l4num) {
		err = -EOPNOTSUPP;
		goto err;
	}

	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
	if (skb2 == NULL) {
		err = -ENOMEM;
		goto err;
	}

	ret = cttimeout_default_fill_info(net, skb2, NETLINK_CB(skb).portid,
					  nlh->nlmsg_seq,
					  NFNL_MSG_TYPE(nlh->nlmsg_type),
					  IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
					  l4proto);
	if (ret <= 0) {
		kfree_skb(skb2);
		err = -ENOMEM;
		goto err;
	}
	ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
	if (ret > 0)
		ret = 0;

	/* this avoids a loop in nfnetlink. */
	return ret == -EAGAIN ? -ENOBUFS : ret;
err:
	nf_ct_l4proto_put(l4proto);
	return err;
}

#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
static struct ctnl_timeout *
ctnl_timeout_find_get(struct net *net, const char *name)
{
	struct ctnl_timeout *timeout, *matching = NULL;

	rcu_read_lock();
	list_for_each_entry_rcu(timeout, &net->nfct_timeout_list, head) {
		if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
			continue;

		if (!try_module_get(THIS_MODULE))
			goto err;

		if (!atomic_inc_not_zero(&timeout->refcnt)) {
			module_put(THIS_MODULE);
			goto err;
		}
		matching = timeout;
		break;
	}
err:
	rcu_read_unlock();
	return matching;
}

static void ctnl_timeout_put(struct ctnl_timeout *timeout)
{
	atomic_dec(&timeout->refcnt);
	module_put(THIS_MODULE);
}
#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */

static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
	[IPCTNL_MSG_TIMEOUT_NEW]	= { .call = cttimeout_new_timeout,
					    .attr_count = CTA_TIMEOUT_MAX,
					    .policy = cttimeout_nla_policy },
	[IPCTNL_MSG_TIMEOUT_GET]	= { .call = cttimeout_get_timeout,
					    .attr_count = CTA_TIMEOUT_MAX,
					    .policy = cttimeout_nla_policy },
	[IPCTNL_MSG_TIMEOUT_DELETE]	= { .call = cttimeout_del_timeout,
					    .attr_count = CTA_TIMEOUT_MAX,
					    .policy = cttimeout_nla_policy },
	[IPCTNL_MSG_TIMEOUT_DEFAULT_SET]= { .call = cttimeout_default_set,
					    .attr_count = CTA_TIMEOUT_MAX,
					    .policy = cttimeout_nla_policy },
	[IPCTNL_MSG_TIMEOUT_DEFAULT_GET]= { .call = cttimeout_default_get,
					    .attr_count = CTA_TIMEOUT_MAX,
					    .policy = cttimeout_nla_policy },
};

static const struct nfnetlink_subsystem cttimeout_subsys = {
	.name				= "conntrack_timeout",
	.subsys_id			= NFNL_SUBSYS_CTNETLINK_TIMEOUT,
	.cb_count			= IPCTNL_MSG_TIMEOUT_MAX,
	.cb				= cttimeout_cb,
};

MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);

static int __net_init cttimeout_net_init(struct net *net)
{
	INIT_LIST_HEAD(&net->nfct_timeout_list);

	return 0;
}

static void __net_exit cttimeout_net_exit(struct net *net)
{
	struct ctnl_timeout *cur, *tmp;

	ctnl_untimeout(net, NULL);

	list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list, head) {
		list_del_rcu(&cur->head);
		nf_ct_l4proto_put(cur->l4proto);
		kfree_rcu(cur, rcu_head);
	}
}

static struct pernet_operations cttimeout_ops = {
	.init	= cttimeout_net_init,
	.exit	= cttimeout_net_exit,
};

static int __init cttimeout_init(void)
{
	int ret;

	ret = register_pernet_subsys(&cttimeout_ops);
	if (ret < 0)
		return ret;

	ret = nfnetlink_subsys_register(&cttimeout_subsys);
	if (ret < 0) {
		pr_err("cttimeout_init: cannot register cttimeout with "
			"nfnetlink.\n");
		goto err_out;
	}
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
	RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get);
	RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put);
#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
	return 0;

err_out:
	unregister_pernet_subsys(&cttimeout_ops);
	return ret;
}

static void __exit cttimeout_exit(void)
{
	pr_info("cttimeout: unregistering from nfnetlink.\n");

	nfnetlink_subsys_unregister(&cttimeout_subsys);

	unregister_pernet_subsys(&cttimeout_ops);
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
	RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
	RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
	rcu_barrier();
}

module_init(cttimeout_init);
module_exit(cttimeout_exit);
Commit	Line	Data
50978462 PNA	1	/*
	2	* (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
	3	* (C) 2012 by Vyatta Inc. <http://www.vyatta.com>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation (or any later at your option).
	8	*/
	9	#include <linux/init.h>
	10	#include <linux/module.h>
	11	#include <linux/kernel.h>
	12	#include <linux/rculist.h>
	13	#include <linux/rculist_nulls.h>
	14	#include <linux/types.h>
	15	#include <linux/timer.h>
	16	#include <linux/security.h>
	17	#include <linux/skbuff.h>
	18	#include <linux/errno.h>
	19	#include <linux/netlink.h>
	20	#include <linux/spinlock.h>
	21	#include <linux/interrupt.h>
	22	#include <linux/slab.h>
	23
	24	#include <linux/netfilter.h>
	25	#include <net/netlink.h>
	26	#include <net/sock.h>
	27	#include <net/netfilter/nf_conntrack.h>
	28	#include <net/netfilter/nf_conntrack_core.h>
	29	#include <net/netfilter/nf_conntrack_l3proto.h>
	30	#include <net/netfilter/nf_conntrack_l4proto.h>
	31	#include <net/netfilter/nf_conntrack_tuple.h>
24de58f4	32	#include <net/netfilter/nf_conntrack_timeout.h>
50978462 PNA	33
	34	#include <linux/netfilter/nfnetlink.h>
	35	#include <linux/netfilter/nfnetlink_cttimeout.h>
	36
	37	MODULE_LICENSE("GPL");
	38	MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
	39	MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning");
	40
50978462	41	static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = {
e93b5f9f FW	42	[CTA_TIMEOUT_NAME] = { .type = NLA_NUL_STRING,
e93b5f9f FW	43	.len = CTNL_TIMEOUT_NAME_MAX - 1},
50978462 PNA	44	[CTA_TIMEOUT_L3PROTO] = { .type = NLA_U16 },
	45	[CTA_TIMEOUT_L4PROTO] = { .type = NLA_U8 },
	46	[CTA_TIMEOUT_DATA] = { .type = NLA_NESTED },
	47	};
	48
	49	static int
91cb498e PNA	50	ctnl_timeout_parse_policy(void timeouts, struct nf_conntrack_l4proto l4proto,
91cb498e PNA	51	struct net net, const struct nlattr attr)
50978462 PNA	52	{
	53	int ret = 0;
	54
	55	if (likely(l4proto->ctnl_timeout.nlattr_to_obj)) {
	56	struct nlattr *tb[l4proto->ctnl_timeout.nlattr_max+1];
	57
130ffbc2 DB	58	ret = nla_parse_nested(tb, l4proto->ctnl_timeout.nlattr_max,
	59	attr, l4proto->ctnl_timeout.nla_policy);
	60	if (ret < 0)
	61	return ret;
50978462	62
91cb498e	63	ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeouts);
50978462 PNA	64	}
	65	return ret;
	66	}
	67
7b8002a1 PNA	68	static int cttimeout_new_timeout(struct net net, struct sock ctnl,
	69	struct sk_buff *skb,
	70	const struct nlmsghdr *nlh,
	71	const struct nlattr * const cda[])
50978462 PNA	72	{
	73	__u16 l3num;
	74	__u8 l4num;
	75	struct nf_conntrack_l4proto *l4proto;
	76	struct ctnl_timeout timeout, matching = NULL;
	77	char *name;
	78	int ret;
	79
	80	if (!cda[CTA_TIMEOUT_NAME] \|\|
	81	!cda[CTA_TIMEOUT_L3PROTO] \|\|
	82	!cda[CTA_TIMEOUT_L4PROTO] \|\|
	83	!cda[CTA_TIMEOUT_DATA])
	84	return -EINVAL;
	85
	86	name = nla_data(cda[CTA_TIMEOUT_NAME]);
	87	l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
	88	l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
	89
19576c94	90	list_for_each_entry(timeout, &net->nfct_timeout_list, head) {
50978462 PNA	91	if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
	92	continue;
	93
	94	if (nlh->nlmsg_flags & NLM_F_EXCL)
	95	return -EEXIST;
	96
	97	matching = timeout;
	98	break;
	99	}
	100
c1ebd7df	101	l4proto = nf_ct_l4proto_find_get(l3num, l4num);
50978462 PNA	102
50978462 PNA	103	/* This protocol is not supportted, skip. */
c1ebd7df PNA	104	if (l4proto->l4proto != l4num) {
	105	ret = -EOPNOTSUPP;
	106	goto err_proto_put;
	107	}
50978462 PNA	108
	109	if (matching) {
	110	if (nlh->nlmsg_flags & NLM_F_REPLACE) {
	111	/* You cannot replace one timeout policy by another of
	112	* different kind, sorry.
	113	*/
	114	if (matching->l3num != l3num \|\|
c1ebd7df PNA	115	matching->l4proto->l4proto != l4num) {
	116	ret = -EINVAL;
	117	goto err_proto_put;
	118	}
50978462	119
91cb498e PNA	120	ret = ctnl_timeout_parse_policy(&matching->data,
91cb498e PNA	121	l4proto, net,
50978462 PNA	122	cda[CTA_TIMEOUT_DATA]);
	123	return ret;
	124	}
c1ebd7df PNA	125	ret = -EBUSY;
c1ebd7df PNA	126	goto err_proto_put;
50978462 PNA	127	}
	128
	129	timeout = kzalloc(sizeof(struct ctnl_timeout) +
	130	l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
c1ebd7df PNA	131	if (timeout == NULL) {
	132	ret = -ENOMEM;
	133	goto err_proto_put;
	134	}
50978462	135
91cb498e	136	ret = ctnl_timeout_parse_policy(&timeout->data, l4proto, net,
50978462 PNA	137	cda[CTA_TIMEOUT_DATA]);
	138	if (ret < 0)
	139	goto err;
	140
	141	strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
	142	timeout->l3num = l3num;
c1ebd7df	143	timeout->l4proto = l4proto;
50978462	144	atomic_set(&timeout->refcnt, 1);
19576c94	145	list_add_tail_rcu(&timeout->head, &net->nfct_timeout_list);
50978462 PNA	146
	147	return 0;
	148	err:
	149	kfree(timeout);
c1ebd7df PNA	150	err_proto_put:
c1ebd7df PNA	151	nf_ct_l4proto_put(l4proto);
50978462 PNA	152	return ret;
	153	}
	154
	155	static int
15e47304	156	ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
50978462 PNA	157	int event, struct ctnl_timeout *timeout)
	158	{
	159	struct nlmsghdr *nlh;
	160	struct nfgenmsg *nfmsg;
15e47304	161	unsigned int flags = portid ? NLM_F_MULTI : 0;
c1ebd7df	162	struct nf_conntrack_l4proto *l4proto = timeout->l4proto;
50978462 PNA	163
50978462 PNA	164	event \|= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8;
15e47304	165	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
50978462 PNA	166	if (nlh == NULL)
	167	goto nlmsg_failure;
	168
	169	nfmsg = nlmsg_data(nlh);
	170	nfmsg->nfgen_family = AF_UNSPEC;
	171	nfmsg->version = NFNETLINK_V0;
	172	nfmsg->res_id = 0;
	173
48f03bda DM	174	if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) \|\|
	175	nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(timeout->l3num)) \|\|
	176	nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, timeout->l4proto->l4proto) \|\|
	177	nla_put_be32(skb, CTA_TIMEOUT_USE,
	178	htonl(atomic_read(&timeout->refcnt))))
	179	goto nla_put_failure;
50978462	180
50978462 PNA	181	if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
	182	struct nlattr *nest_parms;
	183	int ret;
	184
	185	nest_parms = nla_nest_start(skb,
	186	CTA_TIMEOUT_DATA \| NLA_F_NESTED);
	187	if (!nest_parms)
	188	goto nla_put_failure;
	189
	190	ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->data);
	191	if (ret < 0)
	192	goto nla_put_failure;
	193
	194	nla_nest_end(skb, nest_parms);
	195	}
c1ebd7df	196
50978462 PNA	197	nlmsg_end(skb, nlh);
	198	return skb->len;
	199
	200	nlmsg_failure:
	201	nla_put_failure:
	202	nlmsg_cancel(skb, nlh);
	203	return -1;
	204	}
	205
	206	static int
	207	ctnl_timeout_dump(struct sk_buff skb, struct netlink_callback cb)
	208	{
19576c94	209	struct net *net = sock_net(skb->sk);
50978462 PNA	210	struct ctnl_timeout cur, last;
	211
	212	if (cb->args[2])
	213	return 0;
	214
	215	last = (struct ctnl_timeout *)cb->args[1];
	216	if (cb->args[1])
	217	cb->args[1] = 0;
	218
	219	rcu_read_lock();
19576c94	220	list_for_each_entry_rcu(cur, &net->nfct_timeout_list, head) {
37bc4f8d PNA	221	if (last) {
	222	if (cur != last)
	223	continue;
50978462	224
37bc4f8d PNA	225	last = NULL;
37bc4f8d PNA	226	}
15e47304	227	if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
50978462 PNA	228	cb->nlh->nlmsg_seq,
	229	NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
	230	IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
	231	cb->args[1] = (unsigned long)cur;
	232	break;
	233	}
	234	}
	235	if (!cb->args[1])
	236	cb->args[2] = 1;
	237	rcu_read_unlock();
	238	return skb->len;
	239	}
	240
7b8002a1 PNA	241	static int cttimeout_get_timeout(struct net net, struct sock ctnl,
	242	struct sk_buff *skb,
	243	const struct nlmsghdr *nlh,
	244	const struct nlattr * const cda[])
50978462 PNA	245	{
	246	int ret = -ENOENT;
	247	char *name;
	248	struct ctnl_timeout *cur;
	249
	250	if (nlh->nlmsg_flags & NLM_F_DUMP) {
	251	struct netlink_dump_control c = {
	252	.dump = ctnl_timeout_dump,
	253	};
	254	return netlink_dump_start(ctnl, skb, nlh, &c);
	255	}
	256
	257	if (!cda[CTA_TIMEOUT_NAME])
	258	return -EINVAL;
	259	name = nla_data(cda[CTA_TIMEOUT_NAME]);
	260
19576c94	261	list_for_each_entry(cur, &net->nfct_timeout_list, head) {
50978462 PNA	262	struct sk_buff *skb2;
	263
	264	if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
	265	continue;
	266
	267	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
	268	if (skb2 == NULL) {
	269	ret = -ENOMEM;
	270	break;
	271	}
	272
15e47304	273	ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
50978462 PNA	274	nlh->nlmsg_seq,
	275	NFNL_MSG_TYPE(nlh->nlmsg_type),
	276	IPCTNL_MSG_TIMEOUT_NEW, cur);
	277	if (ret <= 0) {
	278	kfree_skb(skb2);
	279	break;
	280	}
15e47304	281	ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
50978462 PNA	282	MSG_DONTWAIT);
	283	if (ret > 0)
	284	ret = 0;
	285
	286	/* this avoids a loop in nfnetlink. */
	287	return ret == -EAGAIN ? -ENOBUFS : ret;
	288	}
	289	return ret;
	290	}
	291
ae2d708e PNA	292	static void untimeout(struct nf_conntrack_tuple_hash *i,
	293	struct ctnl_timeout *timeout)
	294	{
	295	struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(i);
	296	struct nf_conn_timeout *timeout_ext = nf_ct_timeout_find(ct);
	297
	298	if (timeout_ext && (!timeout \|\| timeout_ext->timeout == timeout))
	299	RCU_INIT_POINTER(timeout_ext->timeout, NULL);
	300	}
	301
19576c94	302	static void ctnl_untimeout(struct net net, struct ctnl_timeout timeout)
ae2d708e PNA	303	{
	304	struct nf_conntrack_tuple_hash *h;
	305	const struct hlist_nulls_node *nn;
474803d3 LZ	306	unsigned int last_hsize;
474803d3 LZ	307	spinlock_t *lock;
ae2d708e PNA	308	int i;
	309
	310	local_bh_disable();
474803d3 LZ	311	restart:
	312	last_hsize = nf_conntrack_htable_size;
	313	for (i = 0; i < last_hsize; i++) {
	314	lock = &nf_conntrack_locks[i % CONNTRACK_LOCKS];
	315	nf_conntrack_lock(lock);
	316	if (last_hsize != nf_conntrack_htable_size) {
	317	spin_unlock(lock);
	318	goto restart;
ae2d708e	319	}
474803d3 LZ	320
	321	hlist_nulls_for_each_entry(h, nn, &nf_conntrack_hash[i], hnnode)
	322	untimeout(h, timeout);
	323	spin_unlock(lock);
ae2d708e PNA	324	}
	325	local_bh_enable();
	326	}
	327
50978462	328	/* try to delete object, fail if it is still in use. */
19576c94	329	static int ctnl_timeout_try_del(struct net net, struct ctnl_timeout timeout)
50978462 PNA	330	{
	331	int ret = 0;
	332
	333	/* we want to avoid races with nf_ct_timeout_find_get. */
	334	if (atomic_dec_and_test(&timeout->refcnt)) {
	335	/* We are protected by nfnl mutex. */
	336	list_del_rcu(&timeout->head);
c1ebd7df	337	nf_ct_l4proto_put(timeout->l4proto);
19576c94	338	ctnl_untimeout(net, timeout);
50978462 PNA	339	kfree_rcu(timeout, rcu_head);
	340	} else {
	341	/* still in use, restore reference counter. */
	342	atomic_inc(&timeout->refcnt);
	343	ret = -EBUSY;
	344	}
	345	return ret;
	346	}
	347
7b8002a1 PNA	348	static int cttimeout_del_timeout(struct net net, struct sock ctnl,
	349	struct sk_buff *skb,
	350	const struct nlmsghdr *nlh,
	351	const struct nlattr * const cda[])
50978462	352	{
50978462 PNA	353	struct ctnl_timeout *cur;
50978462 PNA	354	int ret = -ENOENT;
7b8002a1	355	char *name;
50978462 PNA	356
50978462 PNA	357	if (!cda[CTA_TIMEOUT_NAME]) {
19576c94 PN	358	list_for_each_entry(cur, &net->nfct_timeout_list, head)
19576c94 PN	359	ctnl_timeout_try_del(net, cur);
50978462 PNA	360
	361	return 0;
	362	}
	363	name = nla_data(cda[CTA_TIMEOUT_NAME]);
	364
19576c94	365	list_for_each_entry(cur, &net->nfct_timeout_list, head) {
50978462 PNA	366	if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
	367	continue;
	368
19576c94	369	ret = ctnl_timeout_try_del(net, cur);
50978462 PNA	370	if (ret < 0)
	371	return ret;
	372
	373	break;
	374	}
	375	return ret;
	376	}
	377
7b8002a1 PNA	378	static int cttimeout_default_set(struct net net, struct sock ctnl,
	379	struct sk_buff *skb,
	380	const struct nlmsghdr *nlh,
	381	const struct nlattr * const cda[])
91cb498e PNA	382	{
	383	__u16 l3num;
	384	__u8 l4num;
	385	struct nf_conntrack_l4proto *l4proto;
91cb498e PNA	386	unsigned int *timeouts;
	387	int ret;
	388
	389	if (!cda[CTA_TIMEOUT_L3PROTO] \|\|
	390	!cda[CTA_TIMEOUT_L4PROTO] \|\|
	391	!cda[CTA_TIMEOUT_DATA])
	392	return -EINVAL;
	393
	394	l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
	395	l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
	396	l4proto = nf_ct_l4proto_find_get(l3num, l4num);
	397
	398	/* This protocol is not supported, skip. */
	399	if (l4proto->l4proto != l4num) {
	400	ret = -EOPNOTSUPP;
	401	goto err;
	402	}
	403
	404	timeouts = l4proto->get_timeouts(net);
	405
	406	ret = ctnl_timeout_parse_policy(timeouts, l4proto, net,
	407	cda[CTA_TIMEOUT_DATA]);
	408	if (ret < 0)
	409	goto err;
	410
	411	nf_ct_l4proto_put(l4proto);
	412	return 0;
	413	err:
	414	nf_ct_l4proto_put(l4proto);
	415	return ret;
	416	}
	417
	418	static int
	419	cttimeout_default_fill_info(struct net net, struct sk_buff skb, u32 portid,
	420	u32 seq, u32 type, int event,
	421	struct nf_conntrack_l4proto *l4proto)
	422	{
	423	struct nlmsghdr *nlh;
	424	struct nfgenmsg *nfmsg;
	425	unsigned int flags = portid ? NLM_F_MULTI : 0;
	426
	427	event \|= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8;
	428	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
	429	if (nlh == NULL)
	430	goto nlmsg_failure;
	431
	432	nfmsg = nlmsg_data(nlh);
	433	nfmsg->nfgen_family = AF_UNSPEC;
	434	nfmsg->version = NFNETLINK_V0;
	435	nfmsg->res_id = 0;
	436
	437	if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l4proto->l3proto)) \|\|
	438	nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
	439	goto nla_put_failure;
	440
	441	if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
	442	struct nlattr *nest_parms;
	443	unsigned int *timeouts = l4proto->get_timeouts(net);
	444	int ret;
	445
	446	nest_parms = nla_nest_start(skb,
	447	CTA_TIMEOUT_DATA \| NLA_F_NESTED);
	448	if (!nest_parms)
	449	goto nla_put_failure;
450
451	ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, timeouts);
452	if (ret < 0)
453	goto nla_put_failure;
454
455	nla_nest_end(skb, nest_parms);
456	}
457
458	nlmsg_end(skb, nlh);
459	return skb->len;
460
461	nlmsg_failure:
462	nla_put_failure:
463	nlmsg_cancel(skb, nlh);
464	return -1;
465	}
466
7b8002a1 PNA	467	static int cttimeout_default_get(struct net net, struct sock ctnl,
7b8002a1 PNA	468	struct sk_buff *skb,
91cb498e PNA	469	const struct nlmsghdr *nlh,
	470	const struct nlattr * const cda[])
	471	{
	472	__u16 l3num;
	473	__u8 l4num;
	474	struct nf_conntrack_l4proto *l4proto;
91cb498e PNA	475	struct sk_buff *skb2;
	476	int ret, err;
	477
	478	if (!cda[CTA_TIMEOUT_L3PROTO] \|\| !cda[CTA_TIMEOUT_L4PROTO])
	479	return -EINVAL;
	480
	481	l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
	482	l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
	483	l4proto = nf_ct_l4proto_find_get(l3num, l4num);
	484
	485	/* This protocol is not supported, skip. */
	486	if (l4proto->l4proto != l4num) {
	487	err = -EOPNOTSUPP;
	488	goto err;
	489	}
	490
	491	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
	492	if (skb2 == NULL) {
	493	err = -ENOMEM;
	494	goto err;
	495	}
	496
	497	ret = cttimeout_default_fill_info(net, skb2, NETLINK_CB(skb).portid,
	498	nlh->nlmsg_seq,
	499	NFNL_MSG_TYPE(nlh->nlmsg_type),
	500	IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
	501	l4proto);
	502	if (ret <= 0) {
	503	kfree_skb(skb2);
	504	err = -ENOMEM;
	505	goto err;
	506	}
	507	ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
	508	if (ret > 0)
	509	ret = 0;
	510
	511	/* this avoids a loop in nfnetlink. */
	512	return ret == -EAGAIN ? -ENOBUFS : ret;
	513	err:
	514	nf_ct_l4proto_put(l4proto);
	515	return err;
	516	}
	517
24de58f4	518	#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
19576c94 PN	519	static struct ctnl_timeout *
19576c94 PN	520	ctnl_timeout_find_get(struct net net, const char name)
24de58f4 PNA	521	{
	522	struct ctnl_timeout timeout, matching = NULL;
	523
	524	rcu_read_lock();
19576c94	525	list_for_each_entry_rcu(timeout, &net->nfct_timeout_list, head) {
24de58f4 PNA	526	if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
	527	continue;
	528
	529	if (!try_module_get(THIS_MODULE))
	530	goto err;
	531
	532	if (!atomic_inc_not_zero(&timeout->refcnt)) {
	533	module_put(THIS_MODULE);
	534	goto err;
	535	}
	536	matching = timeout;
	537	break;
	538	}
	539	err:
	540	rcu_read_unlock();
	541	return matching;
	542	}
	543
	544	static void ctnl_timeout_put(struct ctnl_timeout *timeout)
	545	{
	546	atomic_dec(&timeout->refcnt);
	547	module_put(THIS_MODULE);
	548	}
	549	#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
	550
50978462 PNA	551	static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
	552	[IPCTNL_MSG_TIMEOUT_NEW] = { .call = cttimeout_new_timeout,
	553	.attr_count = CTA_TIMEOUT_MAX,
	554	.policy = cttimeout_nla_policy },
	555	[IPCTNL_MSG_TIMEOUT_GET] = { .call = cttimeout_get_timeout,
	556	.attr_count = CTA_TIMEOUT_MAX,
	557	.policy = cttimeout_nla_policy },
	558	[IPCTNL_MSG_TIMEOUT_DELETE] = { .call = cttimeout_del_timeout,
	559	.attr_count = CTA_TIMEOUT_MAX,
	560	.policy = cttimeout_nla_policy },
91cb498e PNA	561	[IPCTNL_MSG_TIMEOUT_DEFAULT_SET]= { .call = cttimeout_default_set,
	562	.attr_count = CTA_TIMEOUT_MAX,
	563	.policy = cttimeout_nla_policy },
	564	[IPCTNL_MSG_TIMEOUT_DEFAULT_GET]= { .call = cttimeout_default_get,
	565	.attr_count = CTA_TIMEOUT_MAX,
	566	.policy = cttimeout_nla_policy },
50978462 PNA	567	};
	568
	569	static const struct nfnetlink_subsystem cttimeout_subsys = {
	570	.name = "conntrack_timeout",
	571	.subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
	572	.cb_count = IPCTNL_MSG_TIMEOUT_MAX,
	573	.cb = cttimeout_cb,
	574	};
	575
	576	MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
	577
19576c94 PN	578	static int __net_init cttimeout_net_init(struct net *net)
	579	{
	580	INIT_LIST_HEAD(&net->nfct_timeout_list);
	581
	582	return 0;
	583	}
	584
	585	static void __net_exit cttimeout_net_exit(struct net *net)
	586	{
	587	struct ctnl_timeout cur, tmp;
	588
	589	ctnl_untimeout(net, NULL);
	590
	591	list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list, head) {
	592	list_del_rcu(&cur->head);
	593	nf_ct_l4proto_put(cur->l4proto);
	594	kfree_rcu(cur, rcu_head);
	595	}
	596	}
	597
	598	static struct pernet_operations cttimeout_ops = {
	599	.init = cttimeout_net_init,
	600	.exit = cttimeout_net_exit,
	601	};
	602
50978462 PNA	603	static int __init cttimeout_init(void)
	604	{
	605	int ret;
	606
19576c94 PN	607	ret = register_pernet_subsys(&cttimeout_ops);
	608	if (ret < 0)
	609	return ret;
	610
50978462 PNA	611	ret = nfnetlink_subsys_register(&cttimeout_subsys);
	612	if (ret < 0) {
	613	pr_err("cttimeout_init: cannot register cttimeout with "
	614	"nfnetlink.\n");
	615	goto err_out;
	616	}
24de58f4 PNA	617	#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
	618	RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get);
	619	RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put);
	620	#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
50978462 PNA	621	return 0;
	622
	623	err_out:
19576c94	624	unregister_pernet_subsys(&cttimeout_ops);
50978462 PNA	625	return ret;
	626	}
	627
	628	static void __exit cttimeout_exit(void)
	629	{
50978462 PNA	630	pr_info("cttimeout: unregistering from nfnetlink.\n");
	631
	632	nfnetlink_subsys_unregister(&cttimeout_subsys);
ae2d708e	633
19576c94	634	unregister_pernet_subsys(&cttimeout_ops);
24de58f4 PNA	635	#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
	636	RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
	637	RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
	638	#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
4302f5ee	639	rcu_barrier();
50978462 PNA	640	}
	641
	642	module_init(cttimeout_init);
	643	module_exit(cttimeout_exit);