[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;
	int i;

	local_bh_disable();
	for (i = 0; i < net->ct.htable_size; i++) {
		nf_conntrack_lock(&nf_conntrack_locks[i % CONNTRACK_LOCKS]);
		if (i < net->ct.htable_size) {
			hlist_nulls_for_each_entry(h, nn, &net->ct.hash[i], hnnode)
				untimeout(h, timeout);
		}
		spin_unlock(&nf_conntrack_locks[i % CONNTRACK_LOCKS]);
	}
	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;
	306	int i;
	307
	308	local_bh_disable();
19576c94	309	for (i = 0; i < net->ct.htable_size; i++) {
b16c2919	310	nf_conntrack_lock(&nf_conntrack_locks[i % CONNTRACK_LOCKS]);
19576c94 PN	311	if (i < net->ct.htable_size) {
19576c94 PN	312	hlist_nulls_for_each_entry(h, nn, &net->ct.hash[i], hnnode)
ae2d708e PNA	313	untimeout(h, timeout);
ae2d708e PNA	314	}
53c520c2	315	spin_unlock(&nf_conntrack_locks[i % CONNTRACK_LOCKS]);
ae2d708e PNA	316	}
	317	local_bh_enable();
	318	}
	319
50978462	320	/* try to delete object, fail if it is still in use. */
19576c94	321	static int ctnl_timeout_try_del(struct net net, struct ctnl_timeout timeout)
50978462 PNA	322	{
	323	int ret = 0;
	324
	325	/* we want to avoid races with nf_ct_timeout_find_get. */
	326	if (atomic_dec_and_test(&timeout->refcnt)) {
	327	/* We are protected by nfnl mutex. */
	328	list_del_rcu(&timeout->head);
c1ebd7df	329	nf_ct_l4proto_put(timeout->l4proto);
19576c94	330	ctnl_untimeout(net, timeout);
50978462 PNA	331	kfree_rcu(timeout, rcu_head);
	332	} else {
	333	/* still in use, restore reference counter. */
	334	atomic_inc(&timeout->refcnt);
	335	ret = -EBUSY;
	336	}
	337	return ret;
	338	}
	339
7b8002a1 PNA	340	static int cttimeout_del_timeout(struct net net, struct sock ctnl,
	341	struct sk_buff *skb,
	342	const struct nlmsghdr *nlh,
	343	const struct nlattr * const cda[])
50978462	344	{
50978462 PNA	345	struct ctnl_timeout *cur;
50978462 PNA	346	int ret = -ENOENT;
7b8002a1	347	char *name;
50978462 PNA	348
50978462 PNA	349	if (!cda[CTA_TIMEOUT_NAME]) {
19576c94 PN	350	list_for_each_entry(cur, &net->nfct_timeout_list, head)
19576c94 PN	351	ctnl_timeout_try_del(net, cur);
50978462 PNA	352
	353	return 0;
	354	}
	355	name = nla_data(cda[CTA_TIMEOUT_NAME]);
	356
19576c94	357	list_for_each_entry(cur, &net->nfct_timeout_list, head) {
50978462 PNA	358	if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
	359	continue;
	360
19576c94	361	ret = ctnl_timeout_try_del(net, cur);
50978462 PNA	362	if (ret < 0)
	363	return ret;
	364
	365	break;
	366	}
	367	return ret;
	368	}
	369
7b8002a1 PNA	370	static int cttimeout_default_set(struct net net, struct sock ctnl,
	371	struct sk_buff *skb,
	372	const struct nlmsghdr *nlh,
	373	const struct nlattr * const cda[])
91cb498e PNA	374	{
	375	__u16 l3num;
	376	__u8 l4num;
	377	struct nf_conntrack_l4proto *l4proto;
91cb498e PNA	378	unsigned int *timeouts;
	379	int ret;
	380
	381	if (!cda[CTA_TIMEOUT_L3PROTO] \|\|
	382	!cda[CTA_TIMEOUT_L4PROTO] \|\|
	383	!cda[CTA_TIMEOUT_DATA])
	384	return -EINVAL;
	385
	386	l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
	387	l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
	388	l4proto = nf_ct_l4proto_find_get(l3num, l4num);
	389
	390	/* This protocol is not supported, skip. */
	391	if (l4proto->l4proto != l4num) {
	392	ret = -EOPNOTSUPP;
	393	goto err;
	394	}
	395
	396	timeouts = l4proto->get_timeouts(net);
	397
	398	ret = ctnl_timeout_parse_policy(timeouts, l4proto, net,
	399	cda[CTA_TIMEOUT_DATA]);
	400	if (ret < 0)
	401	goto err;
	402
	403	nf_ct_l4proto_put(l4proto);
	404	return 0;
	405	err:
	406	nf_ct_l4proto_put(l4proto);
	407	return ret;
	408	}
	409
	410	static int
	411	cttimeout_default_fill_info(struct net net, struct sk_buff skb, u32 portid,
	412	u32 seq, u32 type, int event,
	413	struct nf_conntrack_l4proto *l4proto)
	414	{
	415	struct nlmsghdr *nlh;
	416	struct nfgenmsg *nfmsg;
	417	unsigned int flags = portid ? NLM_F_MULTI : 0;
	418
	419	event \|= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8;
	420	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
	421	if (nlh == NULL)
	422	goto nlmsg_failure;
	423
	424	nfmsg = nlmsg_data(nlh);
	425	nfmsg->nfgen_family = AF_UNSPEC;
	426	nfmsg->version = NFNETLINK_V0;
	427	nfmsg->res_id = 0;
	428
	429	if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l4proto->l3proto)) \|\|
	430	nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
	431	goto nla_put_failure;
	432
	433	if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
	434	struct nlattr *nest_parms;
	435	unsigned int *timeouts = l4proto->get_timeouts(net);
	436	int ret;
	437
	438	nest_parms = nla_nest_start(skb,
	439	CTA_TIMEOUT_DATA \| NLA_F_NESTED);
	440	if (!nest_parms)
	441	goto nla_put_failure;
442
443	ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, timeouts);
444	if (ret < 0)
445	goto nla_put_failure;
446
447	nla_nest_end(skb, nest_parms);
448	}
449
450	nlmsg_end(skb, nlh);
451	return skb->len;
452
453	nlmsg_failure:
454	nla_put_failure:
455	nlmsg_cancel(skb, nlh);
456	return -1;
457	}
458
7b8002a1 PNA	459	static int cttimeout_default_get(struct net net, struct sock ctnl,
7b8002a1 PNA	460	struct sk_buff *skb,
91cb498e PNA	461	const struct nlmsghdr *nlh,
	462	const struct nlattr * const cda[])
	463	{
	464	__u16 l3num;
	465	__u8 l4num;
	466	struct nf_conntrack_l4proto *l4proto;
91cb498e PNA	467	struct sk_buff *skb2;
	468	int ret, err;
	469
	470	if (!cda[CTA_TIMEOUT_L3PROTO] \|\| !cda[CTA_TIMEOUT_L4PROTO])
	471	return -EINVAL;
	472
	473	l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
	474	l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
	475	l4proto = nf_ct_l4proto_find_get(l3num, l4num);
	476
	477	/* This protocol is not supported, skip. */
	478	if (l4proto->l4proto != l4num) {
	479	err = -EOPNOTSUPP;
	480	goto err;
	481	}
	482
	483	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
	484	if (skb2 == NULL) {
	485	err = -ENOMEM;
	486	goto err;
	487	}
	488
	489	ret = cttimeout_default_fill_info(net, skb2, NETLINK_CB(skb).portid,
	490	nlh->nlmsg_seq,
	491	NFNL_MSG_TYPE(nlh->nlmsg_type),
	492	IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
	493	l4proto);
	494	if (ret <= 0) {
	495	kfree_skb(skb2);
	496	err = -ENOMEM;
	497	goto err;
	498	}
	499	ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
	500	if (ret > 0)
	501	ret = 0;
	502
	503	/* this avoids a loop in nfnetlink. */
	504	return ret == -EAGAIN ? -ENOBUFS : ret;
	505	err:
	506	nf_ct_l4proto_put(l4proto);
	507	return err;
	508	}
	509
24de58f4	510	#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
19576c94 PN	511	static struct ctnl_timeout *
19576c94 PN	512	ctnl_timeout_find_get(struct net net, const char name)
24de58f4 PNA	513	{
	514	struct ctnl_timeout timeout, matching = NULL;
	515
	516	rcu_read_lock();
19576c94	517	list_for_each_entry_rcu(timeout, &net->nfct_timeout_list, head) {
24de58f4 PNA	518	if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
	519	continue;
	520
	521	if (!try_module_get(THIS_MODULE))
	522	goto err;
	523
	524	if (!atomic_inc_not_zero(&timeout->refcnt)) {
	525	module_put(THIS_MODULE);
	526	goto err;
	527	}
	528	matching = timeout;
	529	break;
	530	}
	531	err:
	532	rcu_read_unlock();
	533	return matching;
	534	}
	535
	536	static void ctnl_timeout_put(struct ctnl_timeout *timeout)
	537	{
	538	atomic_dec(&timeout->refcnt);
	539	module_put(THIS_MODULE);
	540	}
	541	#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
	542
50978462 PNA	543	static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
	544	[IPCTNL_MSG_TIMEOUT_NEW] = { .call = cttimeout_new_timeout,
	545	.attr_count = CTA_TIMEOUT_MAX,
	546	.policy = cttimeout_nla_policy },
	547	[IPCTNL_MSG_TIMEOUT_GET] = { .call = cttimeout_get_timeout,
	548	.attr_count = CTA_TIMEOUT_MAX,
	549	.policy = cttimeout_nla_policy },
	550	[IPCTNL_MSG_TIMEOUT_DELETE] = { .call = cttimeout_del_timeout,
	551	.attr_count = CTA_TIMEOUT_MAX,
	552	.policy = cttimeout_nla_policy },
91cb498e PNA	553	[IPCTNL_MSG_TIMEOUT_DEFAULT_SET]= { .call = cttimeout_default_set,
	554	.attr_count = CTA_TIMEOUT_MAX,
	555	.policy = cttimeout_nla_policy },
	556	[IPCTNL_MSG_TIMEOUT_DEFAULT_GET]= { .call = cttimeout_default_get,
	557	.attr_count = CTA_TIMEOUT_MAX,
	558	.policy = cttimeout_nla_policy },
50978462 PNA	559	};
	560
	561	static const struct nfnetlink_subsystem cttimeout_subsys = {
	562	.name = "conntrack_timeout",
	563	.subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
	564	.cb_count = IPCTNL_MSG_TIMEOUT_MAX,
	565	.cb = cttimeout_cb,
	566	};
	567
	568	MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
	569
19576c94 PN	570	static int __net_init cttimeout_net_init(struct net *net)
	571	{
	572	INIT_LIST_HEAD(&net->nfct_timeout_list);
	573
	574	return 0;
	575	}
	576
	577	static void __net_exit cttimeout_net_exit(struct net *net)
	578	{
	579	struct ctnl_timeout cur, tmp;
	580
	581	ctnl_untimeout(net, NULL);
	582
	583	list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list, head) {
	584	list_del_rcu(&cur->head);
	585	nf_ct_l4proto_put(cur->l4proto);
	586	kfree_rcu(cur, rcu_head);
	587	}
	588	}
	589
	590	static struct pernet_operations cttimeout_ops = {
	591	.init = cttimeout_net_init,
	592	.exit = cttimeout_net_exit,
	593	};
	594
50978462 PNA	595	static int __init cttimeout_init(void)
	596	{
	597	int ret;
	598
19576c94 PN	599	ret = register_pernet_subsys(&cttimeout_ops);
	600	if (ret < 0)
	601	return ret;
	602
50978462 PNA	603	ret = nfnetlink_subsys_register(&cttimeout_subsys);
	604	if (ret < 0) {
	605	pr_err("cttimeout_init: cannot register cttimeout with "
	606	"nfnetlink.\n");
	607	goto err_out;
	608	}
24de58f4 PNA	609	#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
	610	RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get);
	611	RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put);
	612	#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
50978462 PNA	613	return 0;
	614
	615	err_out:
19576c94	616	unregister_pernet_subsys(&cttimeout_ops);
50978462 PNA	617	return ret;
	618	}
	619
	620	static void __exit cttimeout_exit(void)
	621	{
50978462 PNA	622	pr_info("cttimeout: unregistering from nfnetlink.\n");
	623
	624	nfnetlink_subsys_unregister(&cttimeout_subsys);
ae2d708e	625
19576c94	626	unregister_pernet_subsys(&cttimeout_ops);
24de58f4 PNA	627	#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
	628	RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
	629	RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
	630	#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
4302f5ee	631	rcu_barrier();
50978462 PNA	632	}
	633
	634	module_init(cttimeout_init);
	635	module_exit(cttimeout_exit);