[linux-2.6-block.git] / net / netfilter / nfnetlink_cthelper.c

/*
 * (C) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
 *
 * 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).
 *
 * This software has been sponsored by Vyatta Inc. <http://www.vyatta.com>
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/rculist.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <net/netlink.h>
#include <net/sock.h>

#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_expect.h>
#include <net/netfilter/nf_conntrack_ecache.h>

#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_conntrack.h>
#include <linux/netfilter/nfnetlink_cthelper.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
MODULE_DESCRIPTION("nfnl_cthelper: User-space connection tracking helpers");

static int
nfnl_userspace_cthelper(struct sk_buff *skb, unsigned int protoff,
			struct nf_conn *ct, enum ip_conntrack_info ctinfo)
{
	const struct nf_conn_help *help;
	struct nf_conntrack_helper *helper;

	help = nfct_help(ct);
	if (help == NULL)
		return NF_DROP;

	/* rcu_read_lock()ed by nf_hook_slow */
	helper = rcu_dereference(help->helper);
	if (helper == NULL)
		return NF_DROP;

	/* This is an user-space helper not yet configured, skip. */
	if ((helper->flags &
	    (NF_CT_HELPER_F_USERSPACE | NF_CT_HELPER_F_CONFIGURED)) ==
	     NF_CT_HELPER_F_USERSPACE)
		return NF_ACCEPT;

	/* If the user-space helper is not available, don't block traffic. */
	return NF_QUEUE_NR(helper->queue_num) | NF_VERDICT_FLAG_QUEUE_BYPASS;
}

static const struct nla_policy nfnl_cthelper_tuple_pol[NFCTH_TUPLE_MAX+1] = {
	[NFCTH_TUPLE_L3PROTONUM] = { .type = NLA_U16, },
	[NFCTH_TUPLE_L4PROTONUM] = { .type = NLA_U8, },
};

static int
nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple,
			  const struct nlattr *attr)
{
	int err;
	struct nlattr *tb[NFCTH_TUPLE_MAX+1];

	err = nla_parse_nested(tb, NFCTH_TUPLE_MAX, attr, nfnl_cthelper_tuple_pol);
	if (err < 0)
		return err;

	if (!tb[NFCTH_TUPLE_L3PROTONUM] || !tb[NFCTH_TUPLE_L4PROTONUM])
		return -EINVAL;

	/* Not all fields are initialized so first zero the tuple */
	memset(tuple, 0, sizeof(struct nf_conntrack_tuple));

	tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM]));
	tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]);

	return 0;
}

static int
nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct)
{
	struct nf_conn_help *help = nfct_help(ct);

	if (attr == NULL)
		return -EINVAL;

	if (help->helper->data_len == 0)
		return -EINVAL;

	memcpy(help->data, nla_data(attr), help->helper->data_len);
	return 0;
}

static int
nfnl_cthelper_to_nlattr(struct sk_buff *skb, const struct nf_conn *ct)
{
	const struct nf_conn_help *help = nfct_help(ct);

	if (help->helper->data_len &&
	    nla_put(skb, CTA_HELP_INFO, help->helper->data_len, &help->data))
		goto nla_put_failure;

	return 0;

nla_put_failure:
	return -ENOSPC;
}

static const struct nla_policy nfnl_cthelper_expect_pol[NFCTH_POLICY_MAX+1] = {
	[NFCTH_POLICY_NAME] = { .type = NLA_NUL_STRING,
				.len = NF_CT_HELPER_NAME_LEN-1 },
	[NFCTH_POLICY_EXPECT_MAX] = { .type = NLA_U32, },
	[NFCTH_POLICY_EXPECT_TIMEOUT] = { .type = NLA_U32, },
};

static int
nfnl_cthelper_expect_policy(struct nf_conntrack_expect_policy *expect_policy,
			    const struct nlattr *attr)
{
	int err;
	struct nlattr *tb[NFCTH_POLICY_MAX+1];

	err = nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, nfnl_cthelper_expect_pol);
	if (err < 0)
		return err;

	if (!tb[NFCTH_POLICY_NAME] ||
	    !tb[NFCTH_POLICY_EXPECT_MAX] ||
	    !tb[NFCTH_POLICY_EXPECT_TIMEOUT])
		return -EINVAL;

	strncpy(expect_policy->name,
		nla_data(tb[NFCTH_POLICY_NAME]), NF_CT_HELPER_NAME_LEN);
	expect_policy->max_expected =
		ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX]));
	expect_policy->timeout =
		ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT]));

	return 0;
}

static const struct nla_policy
nfnl_cthelper_expect_policy_set[NFCTH_POLICY_SET_MAX+1] = {
	[NFCTH_POLICY_SET_NUM] = { .type = NLA_U32, },
};

static int
nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper,
				  const struct nlattr *attr)
{
	int i, ret;
	struct nf_conntrack_expect_policy *expect_policy;
	struct nlattr *tb[NFCTH_POLICY_SET_MAX+1];

	ret = nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr,
			       nfnl_cthelper_expect_policy_set);
	if (ret < 0)
		return ret;

	if (!tb[NFCTH_POLICY_SET_NUM])
		return -EINVAL;

	helper->expect_class_max =
		ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM]));

	if (helper->expect_class_max != 0 &&
	    helper->expect_class_max > NF_CT_MAX_EXPECT_CLASSES)
		return -EOVERFLOW;

	expect_policy = kzalloc(sizeof(struct nf_conntrack_expect_policy) *
				helper->expect_class_max, GFP_KERNEL);
	if (expect_policy == NULL)
		return -ENOMEM;

	for (i=0; i<helper->expect_class_max; i++) {
		if (!tb[NFCTH_POLICY_SET+i])
			goto err;

		ret = nfnl_cthelper_expect_policy(&expect_policy[i],
						  tb[NFCTH_POLICY_SET+i]);
		if (ret < 0)
			goto err;
	}
	helper->expect_policy = expect_policy;
	return 0;
err:
	kfree(expect_policy);
	return -EINVAL;
}

static int
nfnl_cthelper_create(const struct nlattr * const tb[],
		     struct nf_conntrack_tuple *tuple)
{
	struct nf_conntrack_helper *helper;
	int ret;

	if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN])
		return -EINVAL;

	helper = kzalloc(sizeof(struct nf_conntrack_helper), GFP_KERNEL);
	if (helper == NULL)
		return -ENOMEM;

	ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]);
	if (ret < 0)
		goto err;

	strncpy(helper->name, nla_data(tb[NFCTH_NAME]), NF_CT_HELPER_NAME_LEN);
	helper->data_len = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN]));
	helper->flags |= NF_CT_HELPER_F_USERSPACE;
	memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple));

	helper->me = THIS_MODULE;
	helper->help = nfnl_userspace_cthelper;
	helper->from_nlattr = nfnl_cthelper_from_nlattr;
	helper->to_nlattr = nfnl_cthelper_to_nlattr;

	/* Default to queue number zero, this can be updated at any time. */
	if (tb[NFCTH_QUEUE_NUM])
		helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));

	if (tb[NFCTH_STATUS]) {
		int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));

		switch(status) {
		case NFCT_HELPER_STATUS_ENABLED:
			helper->flags |= NF_CT_HELPER_F_CONFIGURED;
			break;
		case NFCT_HELPER_STATUS_DISABLED:
			helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
			break;
		}
	}

	ret = nf_conntrack_helper_register(helper);
	if (ret < 0)
		goto err;

	return 0;
err:
	kfree(helper);
	return ret;
}

static int
nfnl_cthelper_update(const struct nlattr * const tb[],
		     struct nf_conntrack_helper *helper)
{
	int ret;

	if (tb[NFCTH_PRIV_DATA_LEN])
		return -EBUSY;

	if (tb[NFCTH_POLICY]) {
		ret = nfnl_cthelper_parse_expect_policy(helper,
							tb[NFCTH_POLICY]);
		if (ret < 0)
			return ret;
	}
	if (tb[NFCTH_QUEUE_NUM])
		helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));

	if (tb[NFCTH_STATUS]) {
		int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));

		switch(status) {
		case NFCT_HELPER_STATUS_ENABLED:
			helper->flags |= NF_CT_HELPER_F_CONFIGURED;
			break;
		case NFCT_HELPER_STATUS_DISABLED:
			helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
			break;
		}
	}
	return 0;
}

static int
nfnl_cthelper_new(struct sock *nfnl, struct sk_buff *skb,
		  const struct nlmsghdr *nlh, const struct nlattr * const tb[])
{
	const char *helper_name;
	struct nf_conntrack_helper *cur, *helper = NULL;
	struct nf_conntrack_tuple tuple;
	int ret = 0, i;

	if (!tb[NFCTH_NAME] || !tb[NFCTH_TUPLE])
		return -EINVAL;

	helper_name = nla_data(tb[NFCTH_NAME]);

	ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
	if (ret < 0)
		return ret;

	rcu_read_lock();
	for (i = 0; i < nf_ct_helper_hsize && !helper; i++) {
		hlist_for_each_entry_rcu(cur, &nf_ct_helper_hash[i], hnode) {

			/* skip non-userspace conntrack helpers. */
			if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
				continue;

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

			if ((tuple.src.l3num != cur->tuple.src.l3num ||
			     tuple.dst.protonum != cur->tuple.dst.protonum))
				continue;

			if (nlh->nlmsg_flags & NLM_F_EXCL) {
				ret = -EEXIST;
				goto err;
			}
			helper = cur;
			break;
		}
	}
	rcu_read_unlock();

	if (helper == NULL)
		ret = nfnl_cthelper_create(tb, &tuple);
	else
		ret = nfnl_cthelper_update(tb, helper);

	return ret;
err:
	rcu_read_unlock();
	return ret;
}

static int
nfnl_cthelper_dump_tuple(struct sk_buff *skb,
			 struct nf_conntrack_helper *helper)
{
	struct nlattr *nest_parms;

	nest_parms = nla_nest_start(skb, NFCTH_TUPLE | NLA_F_NESTED);
	if (nest_parms == NULL)
		goto nla_put_failure;

	if (nla_put_be16(skb, NFCTH_TUPLE_L3PROTONUM,
			 htons(helper->tuple.src.l3num)))
		goto nla_put_failure;

	if (nla_put_u8(skb, NFCTH_TUPLE_L4PROTONUM, helper->tuple.dst.protonum))
		goto nla_put_failure;

	nla_nest_end(skb, nest_parms);
	return 0;

nla_put_failure:
	return -1;
}

static int
nfnl_cthelper_dump_policy(struct sk_buff *skb,
			struct nf_conntrack_helper *helper)
{
	int i;
	struct nlattr *nest_parms1, *nest_parms2;

	nest_parms1 = nla_nest_start(skb, NFCTH_POLICY | NLA_F_NESTED);
	if (nest_parms1 == NULL)
		goto nla_put_failure;

	if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM,
			 htonl(helper->expect_class_max)))
		goto nla_put_failure;

	for (i=0; i<helper->expect_class_max; i++) {
		nest_parms2 = nla_nest_start(skb,
				(NFCTH_POLICY_SET+i) | NLA_F_NESTED);
		if (nest_parms2 == NULL)
			goto nla_put_failure;

		if (nla_put_string(skb, NFCTH_POLICY_NAME,
				   helper->expect_policy[i].name))
			goto nla_put_failure;

		if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_MAX,
				 htonl(helper->expect_policy[i].max_expected)))
			goto nla_put_failure;

		if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_TIMEOUT,
				 htonl(helper->expect_policy[i].timeout)))
			goto nla_put_failure;

		nla_nest_end(skb, nest_parms2);
	}
	nla_nest_end(skb, nest_parms1);
	return 0;

nla_put_failure:
	return -1;
}

static int
nfnl_cthelper_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
			int event, struct nf_conntrack_helper *helper)
{
	struct nlmsghdr *nlh;
	struct nfgenmsg *nfmsg;
	unsigned int flags = portid ? NLM_F_MULTI : 0;
	int status;

	event |= NFNL_SUBSYS_CTHELPER << 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, NFCTH_NAME, helper->name))
		goto nla_put_failure;

	if (nla_put_be32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num)))
		goto nla_put_failure;

	if (nfnl_cthelper_dump_tuple(skb, helper) < 0)
		goto nla_put_failure;

	if (nfnl_cthelper_dump_policy(skb, helper) < 0)
		goto nla_put_failure;

	if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len)))
		goto nla_put_failure;

	if (helper->flags & NF_CT_HELPER_F_CONFIGURED)
		status = NFCT_HELPER_STATUS_ENABLED;
	else
		status = NFCT_HELPER_STATUS_DISABLED;

	if (nla_put_be32(skb, NFCTH_STATUS, htonl(status)))
		goto nla_put_failure;

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

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

static int
nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
{
	struct nf_conntrack_helper *cur, *last;

	rcu_read_lock();
	last = (struct nf_conntrack_helper *)cb->args[1];
	for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) {
restart:
		hlist_for_each_entry_rcu(cur,
				&nf_ct_helper_hash[cb->args[0]], hnode) {

			/* skip non-userspace conntrack helpers. */
			if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
				continue;

			if (cb->args[1]) {
				if (cur != last)
					continue;
				cb->args[1] = 0;
			}
			if (nfnl_cthelper_fill_info(skb,
					    NETLINK_CB(cb->skb).portid,
					    cb->nlh->nlmsg_seq,
					    NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
					    NFNL_MSG_CTHELPER_NEW, cur) < 0) {
				cb->args[1] = (unsigned long)cur;
				goto out;
			}
		}
	}
	if (cb->args[1]) {
		cb->args[1] = 0;
		goto restart;
	}
out:
	rcu_read_unlock();
	return skb->len;
}

static int
nfnl_cthelper_get(struct sock *nfnl, struct sk_buff *skb,
		  const struct nlmsghdr *nlh, const struct nlattr * const tb[])
{
	int ret = -ENOENT, i;
	struct nf_conntrack_helper *cur;
	struct sk_buff *skb2;
	char *helper_name = NULL;
	struct nf_conntrack_tuple tuple;
	bool tuple_set = false;

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

	if (tb[NFCTH_NAME])
		helper_name = nla_data(tb[NFCTH_NAME]);

	if (tb[NFCTH_TUPLE]) {
		ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
		if (ret < 0)
			return ret;

		tuple_set = true;
	}

	for (i = 0; i < nf_ct_helper_hsize; i++) {
		hlist_for_each_entry_rcu(cur, &nf_ct_helper_hash[i], hnode) {

			/* skip non-userspace conntrack helpers. */
			if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
				continue;

			if (helper_name && strncmp(cur->name, helper_name,
						NF_CT_HELPER_NAME_LEN) != 0) {
				continue;
			}
			if (tuple_set &&
			    (tuple.src.l3num != cur->tuple.src.l3num ||
			     tuple.dst.protonum != cur->tuple.dst.protonum))
				continue;

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

			ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).portid,
						nlh->nlmsg_seq,
						NFNL_MSG_TYPE(nlh->nlmsg_type),
						NFNL_MSG_CTHELPER_NEW, cur);
			if (ret <= 0) {
				kfree_skb(skb2);
				break;
			}

			ret = netlink_unicast(nfnl, 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 int
nfnl_cthelper_del(struct sock *nfnl, struct sk_buff *skb,
	     const struct nlmsghdr *nlh, const struct nlattr * const tb[])
{
	char *helper_name = NULL;
	struct nf_conntrack_helper *cur;
	struct hlist_node *tmp;
	struct nf_conntrack_tuple tuple;
	bool tuple_set = false, found = false;
	int i, j = 0, ret;

	if (tb[NFCTH_NAME])
		helper_name = nla_data(tb[NFCTH_NAME]);

	if (tb[NFCTH_TUPLE]) {
		ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
		if (ret < 0)
			return ret;

		tuple_set = true;
	}

	for (i = 0; i < nf_ct_helper_hsize; i++) {
		hlist_for_each_entry_safe(cur, tmp, &nf_ct_helper_hash[i],
								hnode) {
			/* skip non-userspace conntrack helpers. */
			if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
				continue;

			j++;

			if (helper_name && strncmp(cur->name, helper_name,
						NF_CT_HELPER_NAME_LEN) != 0) {
				continue;
			}
			if (tuple_set &&
			    (tuple.src.l3num != cur->tuple.src.l3num ||
			     tuple.dst.protonum != cur->tuple.dst.protonum))
				continue;

			found = true;
			nf_conntrack_helper_unregister(cur);
		}
	}
	/* Make sure we return success if we flush and there is no helpers */
	return (found || j == 0) ? 0 : -ENOENT;
}

static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = {
	[NFCTH_NAME] = { .type = NLA_NUL_STRING,
			 .len = NF_CT_HELPER_NAME_LEN-1 },
	[NFCTH_QUEUE_NUM] = { .type = NLA_U32, },
};

static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = {
	[NFNL_MSG_CTHELPER_NEW]		= { .call = nfnl_cthelper_new,
					    .attr_count = NFCTH_MAX,
					    .policy = nfnl_cthelper_policy },
	[NFNL_MSG_CTHELPER_GET]		= { .call = nfnl_cthelper_get,
					    .attr_count = NFCTH_MAX,
					    .policy = nfnl_cthelper_policy },
	[NFNL_MSG_CTHELPER_DEL]		= { .call = nfnl_cthelper_del,
					    .attr_count = NFCTH_MAX,
					    .policy = nfnl_cthelper_policy },
};

static const struct nfnetlink_subsystem nfnl_cthelper_subsys = {
	.name				= "cthelper",
	.subsys_id			= NFNL_SUBSYS_CTHELPER,
	.cb_count			= NFNL_MSG_CTHELPER_MAX,
	.cb				= nfnl_cthelper_cb,
};

MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER);

static int __init nfnl_cthelper_init(void)
{
	int ret;

	ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys);
	if (ret < 0) {
		pr_err("nfnl_cthelper: cannot register with nfnetlink.\n");
		goto err_out;
	}
	return 0;
err_out:
	return ret;
}

static void __exit nfnl_cthelper_exit(void)
{
	struct nf_conntrack_helper *cur;
	struct hlist_node *tmp;
	int i;

	nfnetlink_subsys_unregister(&nfnl_cthelper_subsys);

	for (i=0; i<nf_ct_helper_hsize; i++) {
		hlist_for_each_entry_safe(cur, tmp, &nf_ct_helper_hash[i],
									hnode) {
			/* skip non-userspace conntrack helpers. */
			if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
				continue;

			nf_conntrack_helper_unregister(cur);
		}
	}
}

module_init(nfnl_cthelper_init);
module_exit(nfnl_cthelper_exit);
Commit	Line	Data
12f7a505 PNA	1	/*
	2	* (C) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation (or any later at your option).
	7	*
	8	* This software has been sponsored by Vyatta Inc. <http://www.vyatta.com>
	9	*/
	10	#include <linux/init.h>
	11	#include <linux/module.h>
	12	#include <linux/kernel.h>
	13	#include <linux/skbuff.h>
	14	#include <linux/netlink.h>
	15	#include <linux/rculist.h>
	16	#include <linux/slab.h>
	17	#include <linux/types.h>
	18	#include <linux/list.h>
	19	#include <linux/errno.h>
	20	#include <net/netlink.h>
	21	#include <net/sock.h>
	22
	23	#include <net/netfilter/nf_conntrack_helper.h>
	24	#include <net/netfilter/nf_conntrack_expect.h>
	25	#include <net/netfilter/nf_conntrack_ecache.h>
	26
	27	#include <linux/netfilter/nfnetlink.h>
	28	#include <linux/netfilter/nfnetlink_conntrack.h>
	29	#include <linux/netfilter/nfnetlink_cthelper.h>
	30
	31	MODULE_LICENSE("GPL");
	32	MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
	33	MODULE_DESCRIPTION("nfnl_cthelper: User-space connection tracking helpers");
	34
	35	static int
	36	nfnl_userspace_cthelper(struct sk_buff *skb, unsigned int protoff,
	37	struct nf_conn *ct, enum ip_conntrack_info ctinfo)
	38	{
	39	const struct nf_conn_help *help;
	40	struct nf_conntrack_helper *helper;
	41
	42	help = nfct_help(ct);
	43	if (help == NULL)
	44	return NF_DROP;
	45
	46	/* rcu_read_lock()ed by nf_hook_slow */
	47	helper = rcu_dereference(help->helper);
	48	if (helper == NULL)
	49	return NF_DROP;
	50
	51	/* This is an user-space helper not yet configured, skip. */
	52	if ((helper->flags &
	53	(NF_CT_HELPER_F_USERSPACE \| NF_CT_HELPER_F_CONFIGURED)) ==
	54	NF_CT_HELPER_F_USERSPACE)
	55	return NF_ACCEPT;
	56
	57	/* If the user-space helper is not available, don't block traffic. */
	58	return NF_QUEUE_NR(helper->queue_num) \| NF_VERDICT_FLAG_QUEUE_BYPASS;
	59	}
	60
	61	static const struct nla_policy nfnl_cthelper_tuple_pol[NFCTH_TUPLE_MAX+1] = {
	62	[NFCTH_TUPLE_L3PROTONUM] = { .type = NLA_U16, },
	63	[NFCTH_TUPLE_L4PROTONUM] = { .type = NLA_U8, },
	64	};
65
66	static int
67	nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple,
68	const struct nlattr *attr)
69	{
130ffbc2	70	int err;
12f7a505 PNA	71	struct nlattr *tb[NFCTH_TUPLE_MAX+1];
12f7a505 PNA	72
130ffbc2 DB	73	err = nla_parse_nested(tb, NFCTH_TUPLE_MAX, attr, nfnl_cthelper_tuple_pol);
	74	if (err < 0)
	75	return err;
12f7a505 PNA	76
	77	if (!tb[NFCTH_TUPLE_L3PROTONUM] \|\| !tb[NFCTH_TUPLE_L4PROTONUM])
	78	return -EINVAL;
	79
78146572 IW	80	/* Not all fields are initialized so first zero the tuple */
	81	memset(tuple, 0, sizeof(struct nf_conntrack_tuple));
	82
fe31d1a8	83	tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM]));
12f7a505 PNA	84	tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]);
	85
	86	return 0;
	87	}
	88
	89	static int
	90	nfnl_cthelper_from_nlattr(struct nlattr attr, struct nf_conn ct)
	91	{
b18c5d15	92	struct nf_conn_help *help = nfct_help(ct);
12f7a505	93
7be54ca4 PNA	94	if (attr == NULL)
	95	return -EINVAL;
	96
12f7a505 PNA	97	if (help->helper->data_len == 0)
	98	return -EINVAL;
	99
b18c5d15	100	memcpy(help->data, nla_data(attr), help->helper->data_len);
12f7a505 PNA	101	return 0;
	102	}
	103
	104	static int
	105	nfnl_cthelper_to_nlattr(struct sk_buff skb, const struct nf_conn ct)
	106	{
	107	const struct nf_conn_help *help = nfct_help(ct);
	108
	109	if (help->helper->data_len &&
	110	nla_put(skb, CTA_HELP_INFO, help->helper->data_len, &help->data))
	111	goto nla_put_failure;
	112
	113	return 0;
	114
	115	nla_put_failure:
	116	return -ENOSPC;
	117	}
	118
	119	static const struct nla_policy nfnl_cthelper_expect_pol[NFCTH_POLICY_MAX+1] = {
	120	[NFCTH_POLICY_NAME] = { .type = NLA_NUL_STRING,
	121	.len = NF_CT_HELPER_NAME_LEN-1 },
	122	[NFCTH_POLICY_EXPECT_MAX] = { .type = NLA_U32, },
	123	[NFCTH_POLICY_EXPECT_TIMEOUT] = { .type = NLA_U32, },
	124	};
	125
	126	static int
	127	nfnl_cthelper_expect_policy(struct nf_conntrack_expect_policy *expect_policy,
	128	const struct nlattr *attr)
	129	{
130ffbc2	130	int err;
12f7a505 PNA	131	struct nlattr *tb[NFCTH_POLICY_MAX+1];
12f7a505 PNA	132
130ffbc2 DB	133	err = nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, nfnl_cthelper_expect_pol);
	134	if (err < 0)
	135	return err;
12f7a505 PNA	136
	137	if (!tb[NFCTH_POLICY_NAME] \|\|
	138	!tb[NFCTH_POLICY_EXPECT_MAX] \|\|
	139	!tb[NFCTH_POLICY_EXPECT_TIMEOUT])
	140	return -EINVAL;
	141
	142	strncpy(expect_policy->name,
	143	nla_data(tb[NFCTH_POLICY_NAME]), NF_CT_HELPER_NAME_LEN);
	144	expect_policy->max_expected =
	145	ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX]));
	146	expect_policy->timeout =
	147	ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT]));
	148
	149	return 0;
	150	}
	151
	152	static const struct nla_policy
	153	nfnl_cthelper_expect_policy_set[NFCTH_POLICY_SET_MAX+1] = {
	154	[NFCTH_POLICY_SET_NUM] = { .type = NLA_U32, },
	155	};
	156
	157	static int
	158	nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper,
	159	const struct nlattr *attr)
	160	{
	161	int i, ret;
	162	struct nf_conntrack_expect_policy *expect_policy;
	163	struct nlattr *tb[NFCTH_POLICY_SET_MAX+1];
	164
130ffbc2 DB	165	ret = nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr,
	166	nfnl_cthelper_expect_policy_set);
	167	if (ret < 0)
	168	return ret;
12f7a505 PNA	169
	170	if (!tb[NFCTH_POLICY_SET_NUM])
	171	return -EINVAL;
	172
	173	helper->expect_class_max =
	174	ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM]));
	175
	176	if (helper->expect_class_max != 0 &&
	177	helper->expect_class_max > NF_CT_MAX_EXPECT_CLASSES)
	178	return -EOVERFLOW;
	179
	180	expect_policy = kzalloc(sizeof(struct nf_conntrack_expect_policy) *
	181	helper->expect_class_max, GFP_KERNEL);
	182	if (expect_policy == NULL)
	183	return -ENOMEM;
	184
	185	for (i=0; i<helper->expect_class_max; i++) {
	186	if (!tb[NFCTH_POLICY_SET+i])
	187	goto err;
	188
	189	ret = nfnl_cthelper_expect_policy(&expect_policy[i],
	190	tb[NFCTH_POLICY_SET+i]);
	191	if (ret < 0)
	192	goto err;
	193	}
	194	helper->expect_policy = expect_policy;
	195	return 0;
	196	err:
	197	kfree(expect_policy);
	198	return -EINVAL;
	199	}
	200
	201	static int
	202	nfnl_cthelper_create(const struct nlattr * const tb[],
	203	struct nf_conntrack_tuple *tuple)
	204	{
	205	struct nf_conntrack_helper *helper;
	206	int ret;
	207
	208	if (!tb[NFCTH_TUPLE] \|\| !tb[NFCTH_POLICY] \|\| !tb[NFCTH_PRIV_DATA_LEN])
	209	return -EINVAL;
	210
	211	helper = kzalloc(sizeof(struct nf_conntrack_helper), GFP_KERNEL);
	212	if (helper == NULL)
	213	return -ENOMEM;
	214
	215	ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]);
	216	if (ret < 0)
	217	goto err;
	218
	219	strncpy(helper->name, nla_data(tb[NFCTH_NAME]), NF_CT_HELPER_NAME_LEN);
	220	helper->data_len = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN]));
	221	helper->flags \|= NF_CT_HELPER_F_USERSPACE;
	222	memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple));
	223
	224	helper->me = THIS_MODULE;
	225	helper->help = nfnl_userspace_cthelper;
	226	helper->from_nlattr = nfnl_cthelper_from_nlattr;
	227	helper->to_nlattr = nfnl_cthelper_to_nlattr;
	228
	229	/* Default to queue number zero, this can be updated at any time. */
	230	if (tb[NFCTH_QUEUE_NUM])
	231	helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
	232
233	if (tb[NFCTH_STATUS]) {
234	int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
235
236	switch(status) {
237	case NFCT_HELPER_STATUS_ENABLED:
238	helper->flags \|= NF_CT_HELPER_F_CONFIGURED;
239	break;
240	case NFCT_HELPER_STATUS_DISABLED:
241	helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
242	break;
243	}
244	}
245
246	ret = nf_conntrack_helper_register(helper);
247	if (ret < 0)
248	goto err;
249
250	return 0;
251	err:
252	kfree(helper);
253	return ret;
254	}
255
256	static int
257	nfnl_cthelper_update(const struct nlattr * const tb[],
258	struct nf_conntrack_helper *helper)
259	{
260	int ret;
261
262	if (tb[NFCTH_PRIV_DATA_LEN])
263	return -EBUSY;
264
265	if (tb[NFCTH_POLICY]) {
266	ret = nfnl_cthelper_parse_expect_policy(helper,
267	tb[NFCTH_POLICY]);
268	if (ret < 0)
269	return ret;
270	}
271	if (tb[NFCTH_QUEUE_NUM])
272	helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
273
274	if (tb[NFCTH_STATUS]) {
275	int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
276
277	switch(status) {
278	case NFCT_HELPER_STATUS_ENABLED:
279	helper->flags \|= NF_CT_HELPER_F_CONFIGURED;
280	break;
281	case NFCT_HELPER_STATUS_DISABLED:
282	helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
283	break;
284	}
285	}
286	return 0;
287	}
288
289	static int
290	nfnl_cthelper_new(struct sock nfnl, struct sk_buff skb,
291	const struct nlmsghdr nlh, const struct nlattr const tb[])
292	{
293	const char *helper_name;
294	struct nf_conntrack_helper cur, helper = NULL;
295	struct nf_conntrack_tuple tuple;
12f7a505 PNA	296	int ret = 0, i;
	297
	298	if (!tb[NFCTH_NAME] \|\| !tb[NFCTH_TUPLE])
	299	return -EINVAL;
	300
	301	helper_name = nla_data(tb[NFCTH_NAME]);
	302
	303	ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
	304	if (ret < 0)
	305	return ret;
	306
	307	rcu_read_lock();
	308	for (i = 0; i < nf_ct_helper_hsize && !helper; i++) {
b67bfe0d	309	hlist_for_each_entry_rcu(cur, &nf_ct_helper_hash[i], hnode) {
12f7a505 PNA	310
	311	/* skip non-userspace conntrack helpers. */
	312	if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
	313	continue;
	314
	315	if (strncmp(cur->name, helper_name,
	316	NF_CT_HELPER_NAME_LEN) != 0)
	317	continue;
	318
	319	if ((tuple.src.l3num != cur->tuple.src.l3num \|\|
	320	tuple.dst.protonum != cur->tuple.dst.protonum))
	321	continue;
	322
	323	if (nlh->nlmsg_flags & NLM_F_EXCL) {
	324	ret = -EEXIST;
	325	goto err;
	326	}
	327	helper = cur;
	328	break;
	329	}
	330	}
	331	rcu_read_unlock();
	332
	333	if (helper == NULL)
	334	ret = nfnl_cthelper_create(tb, &tuple);
	335	else
	336	ret = nfnl_cthelper_update(tb, helper);
	337
	338	return ret;
	339	err:
	340	rcu_read_unlock();
	341	return ret;
	342	}
	343
	344	static int
	345	nfnl_cthelper_dump_tuple(struct sk_buff *skb,
	346	struct nf_conntrack_helper *helper)
	347	{
	348	struct nlattr *nest_parms;
	349
	350	nest_parms = nla_nest_start(skb, NFCTH_TUPLE \| NLA_F_NESTED);
	351	if (nest_parms == NULL)
	352	goto nla_put_failure;
	353
	354	if (nla_put_be16(skb, NFCTH_TUPLE_L3PROTONUM,
	355	htons(helper->tuple.src.l3num)))
	356	goto nla_put_failure;
	357
	358	if (nla_put_u8(skb, NFCTH_TUPLE_L4PROTONUM, helper->tuple.dst.protonum))
	359	goto nla_put_failure;
	360
	361	nla_nest_end(skb, nest_parms);
	362	return 0;
	363
	364	nla_put_failure:
	365	return -1;
	366	}
	367
	368	static int
	369	nfnl_cthelper_dump_policy(struct sk_buff *skb,
	370	struct nf_conntrack_helper *helper)
	371	{
	372	int i;
	373	struct nlattr nest_parms1, nest_parms2;
374
375	nest_parms1 = nla_nest_start(skb, NFCTH_POLICY \| NLA_F_NESTED);
376	if (nest_parms1 == NULL)
377	goto nla_put_failure;
378
379	if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM,
380	htonl(helper->expect_class_max)))
381	goto nla_put_failure;
382
383	for (i=0; i<helper->expect_class_max; i++) {
384	nest_parms2 = nla_nest_start(skb,
385	(NFCTH_POLICY_SET+i) \| NLA_F_NESTED);
386	if (nest_parms2 == NULL)
387	goto nla_put_failure;
388
389	if (nla_put_string(skb, NFCTH_POLICY_NAME,
390	helper->expect_policy[i].name))
391	goto nla_put_failure;
392
393	if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_MAX,
394	htonl(helper->expect_policy[i].max_expected)))
395	goto nla_put_failure;
396
397	if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_TIMEOUT,
398	htonl(helper->expect_policy[i].timeout)))
399	goto nla_put_failure;
400
401	nla_nest_end(skb, nest_parms2);
402	}
403	nla_nest_end(skb, nest_parms1);
404	return 0;
405
406	nla_put_failure:
407	return -1;
408	}
409
410	static int
15e47304	411	nfnl_cthelper_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
12f7a505 PNA	412	int event, struct nf_conntrack_helper *helper)
	413	{
	414	struct nlmsghdr *nlh;
	415	struct nfgenmsg *nfmsg;
15e47304	416	unsigned int flags = portid ? NLM_F_MULTI : 0;
12f7a505 PNA	417	int status;
	418
	419	event \|= NFNL_SUBSYS_CTHELPER << 8;
15e47304	420	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
12f7a505 PNA	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_string(skb, NFCTH_NAME, helper->name))
	430	goto nla_put_failure;
	431
	432	if (nla_put_be32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num)))
	433	goto nla_put_failure;
	434
	435	if (nfnl_cthelper_dump_tuple(skb, helper) < 0)
	436	goto nla_put_failure;
	437
	438	if (nfnl_cthelper_dump_policy(skb, helper) < 0)
	439	goto nla_put_failure;
	440
	441	if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len)))
	442	goto nla_put_failure;
	443
	444	if (helper->flags & NF_CT_HELPER_F_CONFIGURED)
	445	status = NFCT_HELPER_STATUS_ENABLED;
	446	else
	447	status = NFCT_HELPER_STATUS_DISABLED;
	448
	449	if (nla_put_be32(skb, NFCTH_STATUS, htonl(status)))
	450	goto nla_put_failure;
	451
	452	nlmsg_end(skb, nlh);
	453	return skb->len;
	454
	455	nlmsg_failure:
	456	nla_put_failure:
	457	nlmsg_cancel(skb, nlh);
	458	return -1;
	459	}
	460
	461	static int
	462	nfnl_cthelper_dump_table(struct sk_buff skb, struct netlink_callback cb)
	463	{
	464	struct nf_conntrack_helper cur, last;
12f7a505 PNA	465
	466	rcu_read_lock();
	467	last = (struct nf_conntrack_helper *)cb->args[1];
	468	for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) {
	469	restart:
b67bfe0d	470	hlist_for_each_entry_rcu(cur,
12f7a505 PNA	471	&nf_ct_helper_hash[cb->args[0]], hnode) {
	472
	473	/* skip non-userspace conntrack helpers. */
	474	if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
	475	continue;
	476
	477	if (cb->args[1]) {
	478	if (cur != last)
	479	continue;
	480	cb->args[1] = 0;
	481	}
	482	if (nfnl_cthelper_fill_info(skb,
15e47304	483	NETLINK_CB(cb->skb).portid,
12f7a505 PNA	484	cb->nlh->nlmsg_seq,
	485	NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
	486	NFNL_MSG_CTHELPER_NEW, cur) < 0) {
	487	cb->args[1] = (unsigned long)cur;
	488	goto out;
	489	}
	490	}
	491	}
	492	if (cb->args[1]) {
	493	cb->args[1] = 0;
	494	goto restart;
	495	}
	496	out:
	497	rcu_read_unlock();
	498	return skb->len;
	499	}
	500
	501	static int
	502	nfnl_cthelper_get(struct sock nfnl, struct sk_buff skb,
	503	const struct nlmsghdr nlh, const struct nlattr const tb[])
	504	{
	505	int ret = -ENOENT, i;
	506	struct nf_conntrack_helper *cur;
12f7a505 PNA	507	struct sk_buff *skb2;
	508	char *helper_name = NULL;
	509	struct nf_conntrack_tuple tuple;
	510	bool tuple_set = false;
	511
	512	if (nlh->nlmsg_flags & NLM_F_DUMP) {
	513	struct netlink_dump_control c = {
	514	.dump = nfnl_cthelper_dump_table,
	515	};
	516	return netlink_dump_start(nfnl, skb, nlh, &c);
	517	}
	518
	519	if (tb[NFCTH_NAME])
	520	helper_name = nla_data(tb[NFCTH_NAME]);
	521
	522	if (tb[NFCTH_TUPLE]) {
	523	ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
	524	if (ret < 0)
	525	return ret;
	526
	527	tuple_set = true;
	528	}
	529
	530	for (i = 0; i < nf_ct_helper_hsize; i++) {
b67bfe0d	531	hlist_for_each_entry_rcu(cur, &nf_ct_helper_hash[i], hnode) {
12f7a505 PNA	532
	533	/* skip non-userspace conntrack helpers. */
	534	if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
	535	continue;
	536
	537	if (helper_name && strncmp(cur->name, helper_name,
	538	NF_CT_HELPER_NAME_LEN) != 0) {
	539	continue;
	540	}
	541	if (tuple_set &&
	542	(tuple.src.l3num != cur->tuple.src.l3num \|\|
	543	tuple.dst.protonum != cur->tuple.dst.protonum))
	544	continue;
	545
	546	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
	547	if (skb2 == NULL) {
	548	ret = -ENOMEM;
	549	break;
	550	}
	551
15e47304	552	ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).portid,
12f7a505 PNA	553	nlh->nlmsg_seq,
	554	NFNL_MSG_TYPE(nlh->nlmsg_type),
	555	NFNL_MSG_CTHELPER_NEW, cur);
	556	if (ret <= 0) {
	557	kfree_skb(skb2);
	558	break;
	559	}
	560
15e47304	561	ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
12f7a505 PNA	562	MSG_DONTWAIT);
	563	if (ret > 0)
	564	ret = 0;
	565
	566	/* this avoids a loop in nfnetlink. */
	567	return ret == -EAGAIN ? -ENOBUFS : ret;
	568	}
	569	}
	570	return ret;
	571	}
	572
	573	static int
	574	nfnl_cthelper_del(struct sock nfnl, struct sk_buff skb,
	575	const struct nlmsghdr nlh, const struct nlattr const tb[])
	576	{
	577	char *helper_name = NULL;
	578	struct nf_conntrack_helper *cur;
b67bfe0d	579	struct hlist_node *tmp;
12f7a505 PNA	580	struct nf_conntrack_tuple tuple;
	581	bool tuple_set = false, found = false;
	582	int i, j = 0, ret;
	583
	584	if (tb[NFCTH_NAME])
	585	helper_name = nla_data(tb[NFCTH_NAME]);
	586
	587	if (tb[NFCTH_TUPLE]) {
	588	ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
	589	if (ret < 0)
	590	return ret;
	591
	592	tuple_set = true;
	593	}
	594
	595	for (i = 0; i < nf_ct_helper_hsize; i++) {
b67bfe0d	596	hlist_for_each_entry_safe(cur, tmp, &nf_ct_helper_hash[i],
12f7a505 PNA	597	hnode) {
	598	/* skip non-userspace conntrack helpers. */
	599	if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
	600	continue;
	601
	602	j++;
	603
	604	if (helper_name && strncmp(cur->name, helper_name,
	605	NF_CT_HELPER_NAME_LEN) != 0) {
	606	continue;
	607	}
	608	if (tuple_set &&
	609	(tuple.src.l3num != cur->tuple.src.l3num \|\|
	610	tuple.dst.protonum != cur->tuple.dst.protonum))
	611	continue;
	612
	613	found = true;
	614	nf_conntrack_helper_unregister(cur);
	615	}
	616	}
	617	/* Make sure we return success if we flush and there is no helpers */
	618	return (found \|\| j == 0) ? 0 : -ENOENT;
	619	}
	620
	621	static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = {
	622	[NFCTH_NAME] = { .type = NLA_NUL_STRING,
	623	.len = NF_CT_HELPER_NAME_LEN-1 },
	624	[NFCTH_QUEUE_NUM] = { .type = NLA_U32, },
	625	};
	626
	627	static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = {
	628	[NFNL_MSG_CTHELPER_NEW] = { .call = nfnl_cthelper_new,
	629	.attr_count = NFCTH_MAX,
	630	.policy = nfnl_cthelper_policy },
	631	[NFNL_MSG_CTHELPER_GET] = { .call = nfnl_cthelper_get,
	632	.attr_count = NFCTH_MAX,
	633	.policy = nfnl_cthelper_policy },
	634	[NFNL_MSG_CTHELPER_DEL] = { .call = nfnl_cthelper_del,
	635	.attr_count = NFCTH_MAX,
	636	.policy = nfnl_cthelper_policy },
	637	};
	638
	639	static const struct nfnetlink_subsystem nfnl_cthelper_subsys = {
	640	.name = "cthelper",
	641	.subsys_id = NFNL_SUBSYS_CTHELPER,
	642	.cb_count = NFNL_MSG_CTHELPER_MAX,
	643	.cb = nfnl_cthelper_cb,
	644	};
	645
	646	MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER);
	647
	648	static int __init nfnl_cthelper_init(void)
	649	{
	650	int ret;
	651
	652	ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys);
	653	if (ret < 0) {
	654	pr_err("nfnl_cthelper: cannot register with nfnetlink.\n");
	655	goto err_out;
	656	}
	657	return 0;
	658	err_out:
	659	return ret;
	660	}
661
662	static void __exit nfnl_cthelper_exit(void)
663	{
664	struct nf_conntrack_helper *cur;
b67bfe0d	665	struct hlist_node *tmp;
12f7a505 PNA	666	int i;
	667
	668	nfnetlink_subsys_unregister(&nfnl_cthelper_subsys);
	669
	670	for (i=0; i<nf_ct_helper_hsize; i++) {
b67bfe0d	671	hlist_for_each_entry_safe(cur, tmp, &nf_ct_helper_hash[i],
12f7a505 PNA	672	hnode) {
	673	/* skip non-userspace conntrack helpers. */
	674	if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
	675	continue;
	676
	677	nf_conntrack_helper_unregister(cur);
	678	}
	679	}
	680	}
	681
	682	module_init(nfnl_cthelper_init);
	683	module_exit(nfnl_cthelper_exit);