[GitHub/mt8127/android_kernel_alcatel_ttab.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 LIST_HEAD(cttimeout_list);

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

static int
ctnl_timeout_parse_policy(struct ctnl_timeout *timeout,
			  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];

		nla_parse_nested(tb, l4proto->ctnl_timeout.nlattr_max,
				 attr, l4proto->ctnl_timeout.nla_policy);

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

static int
cttimeout_new_timeout(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;
	struct net *net = sock_net(skb->sk);
	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, &cttimeout_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, 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, 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, &cttimeout_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 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, &cttimeout_list, head) {
		if (last && cur != last)
			continue;

		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 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, &cttimeout_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;
}

/* try to delete object, fail if it is still in use. */
static int ctnl_timeout_try_del(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);
		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 sock *ctnl, struct sk_buff *skb,
		      const struct nlmsghdr *nlh,
		      const struct nlattr * const cda[])
{
	char *name;
	struct ctnl_timeout *cur;
	int ret = -ENOENT;

	if (!cda[CTA_TIMEOUT_NAME]) {
		list_for_each_entry(cur, &cttimeout_list, head)
			ctnl_timeout_try_del(cur);

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

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

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

		break;
	}
	return ret;
}

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

	rcu_read_lock();
	list_for_each_entry_rcu(timeout, &cttimeout_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 },
};

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 __init cttimeout_init(void)
{
	int 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:
	return ret;
}

static void __exit cttimeout_exit(void)
{
	struct ctnl_timeout *cur, *tmp;

	pr_info("cttimeout: unregistering from nfnetlink.\n");

	nfnetlink_subsys_unregister(&cttimeout_subsys);
	list_for_each_entry_safe(cur, tmp, &cttimeout_list, head) {
		list_del_rcu(&cur->head);
		/* We are sure that our objects have no clients at this point,
		 * it's safe to release them all without checking refcnt.
		 */
		nf_ct_l4proto_put(cur->l4proto);
		kfree_rcu(cur, rcu_head);
	}
#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 */
}

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 PNA	41	static LIST_HEAD(cttimeout_list);
	42
	43	static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = {
	44	[CTA_TIMEOUT_NAME] = { .type = NLA_NUL_STRING },
	45	[CTA_TIMEOUT_L3PROTO] = { .type = NLA_U16 },
	46	[CTA_TIMEOUT_L4PROTO] = { .type = NLA_U8 },
	47	[CTA_TIMEOUT_DATA] = { .type = NLA_NESTED },
	48	};
	49
	50	static int
	51	ctnl_timeout_parse_policy(struct ctnl_timeout *timeout,
8264deb8 G	52	struct nf_conntrack_l4proto *l4proto,
	53	struct net *net,
	54	const struct nlattr *attr)
50978462 PNA	55	{
	56	int ret = 0;
	57
	58	if (likely(l4proto->ctnl_timeout.nlattr_to_obj)) {
	59	struct nlattr *tb[l4proto->ctnl_timeout.nlattr_max+1];
	60
	61	nla_parse_nested(tb, l4proto->ctnl_timeout.nlattr_max,
	62	attr, l4proto->ctnl_timeout.nla_policy);
	63
8264deb8 G	64	ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net,
8264deb8 G	65	&timeout->data);
50978462 PNA	66	}
	67	return ret;
	68	}
	69
	70	static int
	71	cttimeout_new_timeout(struct sock ctnl, struct sk_buff skb,
	72	const struct nlmsghdr *nlh,
	73	const struct nlattr * const cda[])
	74	{
	75	__u16 l3num;
	76	__u8 l4num;
	77	struct nf_conntrack_l4proto *l4proto;
	78	struct ctnl_timeout timeout, matching = NULL;
8264deb8	79	struct net *net = sock_net(skb->sk);
50978462 PNA	80	char *name;
	81	int ret;
	82
	83	if (!cda[CTA_TIMEOUT_NAME] \|\|
	84	!cda[CTA_TIMEOUT_L3PROTO] \|\|
	85	!cda[CTA_TIMEOUT_L4PROTO] \|\|
	86	!cda[CTA_TIMEOUT_DATA])
	87	return -EINVAL;
	88
	89	name = nla_data(cda[CTA_TIMEOUT_NAME]);
	90	l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
	91	l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
	92
	93	list_for_each_entry(timeout, &cttimeout_list, head) {
	94	if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
	95	continue;
	96
	97	if (nlh->nlmsg_flags & NLM_F_EXCL)
	98	return -EEXIST;
	99
	100	matching = timeout;
	101	break;
	102	}
	103
c1ebd7df	104	l4proto = nf_ct_l4proto_find_get(l3num, l4num);
50978462 PNA	105
50978462 PNA	106	/* This protocol is not supportted, skip. */
c1ebd7df PNA	107	if (l4proto->l4proto != l4num) {
	108	ret = -EOPNOTSUPP;
	109	goto err_proto_put;
	110	}
50978462 PNA	111
	112	if (matching) {
	113	if (nlh->nlmsg_flags & NLM_F_REPLACE) {
	114	/* You cannot replace one timeout policy by another of
	115	* different kind, sorry.
	116	*/
	117	if (matching->l3num != l3num \|\|
c1ebd7df PNA	118	matching->l4proto->l4proto != l4num) {
	119	ret = -EINVAL;
	120	goto err_proto_put;
	121	}
50978462	122
8264deb8	123	ret = ctnl_timeout_parse_policy(matching, l4proto, net,
50978462 PNA	124	cda[CTA_TIMEOUT_DATA]);
	125	return ret;
	126	}
c1ebd7df PNA	127	ret = -EBUSY;
c1ebd7df PNA	128	goto err_proto_put;
50978462 PNA	129	}
	130
	131	timeout = kzalloc(sizeof(struct ctnl_timeout) +
	132	l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
c1ebd7df PNA	133	if (timeout == NULL) {
	134	ret = -ENOMEM;
	135	goto err_proto_put;
	136	}
50978462	137
8264deb8	138	ret = ctnl_timeout_parse_policy(timeout, l4proto, net,
50978462 PNA	139	cda[CTA_TIMEOUT_DATA]);
	140	if (ret < 0)
	141	goto err;
	142
	143	strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
	144	timeout->l3num = l3num;
c1ebd7df	145	timeout->l4proto = l4proto;
50978462 PNA	146	atomic_set(&timeout->refcnt, 1);
	147	list_add_tail_rcu(&timeout->head, &cttimeout_list);
	148
	149	return 0;
	150	err:
	151	kfree(timeout);
c1ebd7df PNA	152	err_proto_put:
c1ebd7df PNA	153	nf_ct_l4proto_put(l4proto);
50978462 PNA	154	return ret;
	155	}
	156
	157	static int
15e47304	158	ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
50978462 PNA	159	int event, struct ctnl_timeout *timeout)
	160	{
	161	struct nlmsghdr *nlh;
	162	struct nfgenmsg *nfmsg;
15e47304	163	unsigned int flags = portid ? NLM_F_MULTI : 0;
c1ebd7df	164	struct nf_conntrack_l4proto *l4proto = timeout->l4proto;
50978462 PNA	165
50978462 PNA	166	event \|= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8;
15e47304	167	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
50978462 PNA	168	if (nlh == NULL)
	169	goto nlmsg_failure;
	170
	171	nfmsg = nlmsg_data(nlh);
	172	nfmsg->nfgen_family = AF_UNSPEC;
	173	nfmsg->version = NFNETLINK_V0;
	174	nfmsg->res_id = 0;
	175
48f03bda DM	176	if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) \|\|
	177	nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(timeout->l3num)) \|\|
	178	nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, timeout->l4proto->l4proto) \|\|
	179	nla_put_be32(skb, CTA_TIMEOUT_USE,
	180	htonl(atomic_read(&timeout->refcnt))))
	181	goto nla_put_failure;
50978462	182
50978462 PNA	183	if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
	184	struct nlattr *nest_parms;
	185	int ret;
	186
	187	nest_parms = nla_nest_start(skb,
	188	CTA_TIMEOUT_DATA \| NLA_F_NESTED);
	189	if (!nest_parms)
	190	goto nla_put_failure;
	191
	192	ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->data);
	193	if (ret < 0)
	194	goto nla_put_failure;
	195
	196	nla_nest_end(skb, nest_parms);
	197	}
c1ebd7df	198
50978462 PNA	199	nlmsg_end(skb, nlh);
	200	return skb->len;
	201
	202	nlmsg_failure:
	203	nla_put_failure:
	204	nlmsg_cancel(skb, nlh);
	205	return -1;
	206	}
	207
	208	static int
	209	ctnl_timeout_dump(struct sk_buff skb, struct netlink_callback cb)
	210	{
	211	struct ctnl_timeout cur, last;
	212
	213	if (cb->args[2])
	214	return 0;
	215
	216	last = (struct ctnl_timeout *)cb->args[1];
	217	if (cb->args[1])
	218	cb->args[1] = 0;
	219
	220	rcu_read_lock();
	221	list_for_each_entry_rcu(cur, &cttimeout_list, head) {
	222	if (last && cur != last)
	223	continue;
	224
15e47304	225	if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
50978462 PNA	226	cb->nlh->nlmsg_seq,
	227	NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
	228	IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
	229	cb->args[1] = (unsigned long)cur;
	230	break;
	231	}
	232	}
	233	if (!cb->args[1])
	234	cb->args[2] = 1;
	235	rcu_read_unlock();
	236	return skb->len;
	237	}
	238
	239	static int
	240	cttimeout_get_timeout(struct sock ctnl, struct sk_buff skb,
	241	const struct nlmsghdr *nlh,
	242	const struct nlattr * const cda[])
	243	{
	244	int ret = -ENOENT;
	245	char *name;
	246	struct ctnl_timeout *cur;
	247
	248	if (nlh->nlmsg_flags & NLM_F_DUMP) {
	249	struct netlink_dump_control c = {
	250	.dump = ctnl_timeout_dump,
	251	};
	252	return netlink_dump_start(ctnl, skb, nlh, &c);
	253	}
	254
	255	if (!cda[CTA_TIMEOUT_NAME])
	256	return -EINVAL;
	257	name = nla_data(cda[CTA_TIMEOUT_NAME]);
	258
	259	list_for_each_entry(cur, &cttimeout_list, head) {
	260	struct sk_buff *skb2;
	261
	262	if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
	263	continue;
	264
	265	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
	266	if (skb2 == NULL) {
	267	ret = -ENOMEM;
	268	break;
	269	}
	270
15e47304	271	ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
50978462 PNA	272	nlh->nlmsg_seq,
	273	NFNL_MSG_TYPE(nlh->nlmsg_type),
	274	IPCTNL_MSG_TIMEOUT_NEW, cur);
	275	if (ret <= 0) {
	276	kfree_skb(skb2);
	277	break;
	278	}
15e47304	279	ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
50978462 PNA	280	MSG_DONTWAIT);
	281	if (ret > 0)
	282	ret = 0;
	283
	284	/* this avoids a loop in nfnetlink. */
	285	return ret == -EAGAIN ? -ENOBUFS : ret;
	286	}
	287	return ret;
	288	}
	289
	290	/* try to delete object, fail if it is still in use. */
	291	static int ctnl_timeout_try_del(struct ctnl_timeout *timeout)
	292	{
	293	int ret = 0;
	294
	295	/* we want to avoid races with nf_ct_timeout_find_get. */
	296	if (atomic_dec_and_test(&timeout->refcnt)) {
	297	/* We are protected by nfnl mutex. */
	298	list_del_rcu(&timeout->head);
c1ebd7df	299	nf_ct_l4proto_put(timeout->l4proto);
50978462 PNA	300	kfree_rcu(timeout, rcu_head);
	301	} else {
	302	/* still in use, restore reference counter. */
	303	atomic_inc(&timeout->refcnt);
	304	ret = -EBUSY;
	305	}
	306	return ret;
	307	}
	308
	309	static int
	310	cttimeout_del_timeout(struct sock ctnl, struct sk_buff skb,
	311	const struct nlmsghdr *nlh,
	312	const struct nlattr * const cda[])
	313	{
	314	char *name;
	315	struct ctnl_timeout *cur;
	316	int ret = -ENOENT;
	317
	318	if (!cda[CTA_TIMEOUT_NAME]) {
	319	list_for_each_entry(cur, &cttimeout_list, head)
	320	ctnl_timeout_try_del(cur);
	321
	322	return 0;
	323	}
	324	name = nla_data(cda[CTA_TIMEOUT_NAME]);
	325
	326	list_for_each_entry(cur, &cttimeout_list, head) {
	327	if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
	328	continue;
	329
	330	ret = ctnl_timeout_try_del(cur);
	331	if (ret < 0)
	332	return ret;
	333
	334	break;
	335	}
	336	return ret;
	337	}
	338
24de58f4 PNA	339	#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
	340	static struct ctnl_timeout ctnl_timeout_find_get(const char name)
	341	{
	342	struct ctnl_timeout timeout, matching = NULL;
	343
	344	rcu_read_lock();
	345	list_for_each_entry_rcu(timeout, &cttimeout_list, head) {
	346	if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
	347	continue;
	348
	349	if (!try_module_get(THIS_MODULE))
	350	goto err;
	351
	352	if (!atomic_inc_not_zero(&timeout->refcnt)) {
	353	module_put(THIS_MODULE);
	354	goto err;
	355	}
	356	matching = timeout;
	357	break;
	358	}
	359	err:
	360	rcu_read_unlock();
	361	return matching;
	362	}
	363
	364	static void ctnl_timeout_put(struct ctnl_timeout *timeout)
	365	{
	366	atomic_dec(&timeout->refcnt);
	367	module_put(THIS_MODULE);
	368	}
	369	#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
	370
50978462 PNA	371	static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
	372	[IPCTNL_MSG_TIMEOUT_NEW] = { .call = cttimeout_new_timeout,
	373	.attr_count = CTA_TIMEOUT_MAX,
	374	.policy = cttimeout_nla_policy },
	375	[IPCTNL_MSG_TIMEOUT_GET] = { .call = cttimeout_get_timeout,
	376	.attr_count = CTA_TIMEOUT_MAX,
	377	.policy = cttimeout_nla_policy },
	378	[IPCTNL_MSG_TIMEOUT_DELETE] = { .call = cttimeout_del_timeout,
	379	.attr_count = CTA_TIMEOUT_MAX,
	380	.policy = cttimeout_nla_policy },
	381	};
	382
	383	static const struct nfnetlink_subsystem cttimeout_subsys = {
	384	.name = "conntrack_timeout",
	385	.subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
	386	.cb_count = IPCTNL_MSG_TIMEOUT_MAX,
	387	.cb = cttimeout_cb,
	388	};
	389
	390	MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
	391
	392	static int __init cttimeout_init(void)
	393	{
	394	int ret;
	395
	396	ret = nfnetlink_subsys_register(&cttimeout_subsys);
	397	if (ret < 0) {
	398	pr_err("cttimeout_init: cannot register cttimeout with "
	399	"nfnetlink.\n");
	400	goto err_out;
	401	}
24de58f4 PNA	402	#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
	403	RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get);
	404	RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put);
	405	#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
50978462 PNA	406	return 0;
	407
	408	err_out:
	409	return ret;
	410	}
	411
	412	static void __exit cttimeout_exit(void)
	413	{
	414	struct ctnl_timeout cur, tmp;
	415
	416	pr_info("cttimeout: unregistering from nfnetlink.\n");
	417
	418	nfnetlink_subsys_unregister(&cttimeout_subsys);
	419	list_for_each_entry_safe(cur, tmp, &cttimeout_list, head) {
	420	list_del_rcu(&cur->head);
	421	/* We are sure that our objects have no clients at this point,
	422	* it's safe to release them all without checking refcnt.
	423	*/
c1ebd7df	424	nf_ct_l4proto_put(cur->l4proto);
50978462 PNA	425	kfree_rcu(cur, rcu_head);
50978462 PNA	426	}
24de58f4 PNA	427	#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
	428	RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
	429	RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
	430	#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
50978462 PNA	431	}
	432
	433	module_init(cttimeout_init);
	434	module_exit(cttimeout_exit);