[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / netfilter / xt_helper.c

/* iptables module to match on related connections */
/*
 * (C) 2001 Martin Josefsson <gandalf@wlug.westbo.se>
 *
 * 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.
 *
 *   19 Mar 2002 Harald Welte <laforge@gnumonks.org>:
 *   		 - Port to newnat infrastructure
 */

#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netfilter.h>
#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
#include <linux/netfilter_ipv4/ip_conntrack.h>
#include <linux/netfilter_ipv4/ip_conntrack_core.h>
#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
#else
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_helper.h>
#endif
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_helper.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Martin Josefsson <gandalf@netfilter.org>");
MODULE_DESCRIPTION("iptables helper match module");
MODULE_ALIAS("ipt_helper");
MODULE_ALIAS("ip6t_helper");

#if 0
#define DEBUGP printk
#else
#define DEBUGP(format, args...)
#endif

#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
static int
match(const struct sk_buff *skb,
      const struct net_device *in,
      const struct net_device *out,
      const void *matchinfo,
      int offset,
      unsigned int protoff,
      int *hotdrop)
{
	const struct xt_helper_info *info = matchinfo;
	struct ip_conntrack *ct;
	enum ip_conntrack_info ctinfo;
	int ret = info->invert;
	
	ct = ip_conntrack_get((struct sk_buff *)skb, &ctinfo);
	if (!ct) {
		DEBUGP("xt_helper: Eek! invalid conntrack?\n");
		return ret;
	}

	if (!ct->master) {
		DEBUGP("xt_helper: conntrack %p has no master\n", ct);
		return ret;
	}

	read_lock_bh(&ip_conntrack_lock);
	if (!ct->master->helper) {
		DEBUGP("xt_helper: master ct %p has no helper\n", 
			exp->expectant);
		goto out_unlock;
	}

	DEBUGP("master's name = %s , info->name = %s\n", 
		ct->master->helper->name, info->name);

	if (info->name[0] == '\0')
		ret ^= 1;
	else
		ret ^= !strncmp(ct->master->helper->name, info->name, 
		                strlen(ct->master->helper->name));
out_unlock:
	read_unlock_bh(&ip_conntrack_lock);
	return ret;
}

#else /* CONFIG_IP_NF_CONNTRACK */

static int
match(const struct sk_buff *skb,
      const struct net_device *in,
      const struct net_device *out,
      const void *matchinfo,
      int offset,
      unsigned int protoff,
      int *hotdrop)
{
	const struct xt_helper_info *info = matchinfo;
	struct nf_conn *ct;
	enum ip_conntrack_info ctinfo;
	int ret = info->invert;
	
	ct = nf_ct_get((struct sk_buff *)skb, &ctinfo);
	if (!ct) {
		DEBUGP("xt_helper: Eek! invalid conntrack?\n");
		return ret;
	}

	if (!ct->master) {
		DEBUGP("xt_helper: conntrack %p has no master\n", ct);
		return ret;
	}

	read_lock_bh(&nf_conntrack_lock);
	if (!ct->master->helper) {
		DEBUGP("xt_helper: master ct %p has no helper\n", 
			exp->expectant);
		goto out_unlock;
	}

	DEBUGP("master's name = %s , info->name = %s\n", 
		ct->master->helper->name, info->name);

	if (info->name[0] == '\0')
		ret ^= 1;
	else
		ret ^= !strncmp(ct->master->helper->name, info->name, 
		                strlen(ct->master->helper->name));
out_unlock:
	read_unlock_bh(&nf_conntrack_lock);
	return ret;
}
#endif

static int check(const char *tablename,
		 const void *inf,
		 void *matchinfo,
		 unsigned int matchsize,
		 unsigned int hook_mask)
{
	struct xt_helper_info *info = matchinfo;

	info->name[29] = '\0';

	/* verify size */
	if (matchsize != XT_ALIGN(sizeof(struct xt_helper_info)))
		return 0;

	return 1;
}

static struct xt_match helper_match = {
	.name		= "helper",
	.match		= &match,
	.checkentry	= &check,
	.me		= THIS_MODULE,
};
static struct xt_match helper6_match = {
	.name		= "helper",
	.match		= &match,
	.checkentry	= &check,
	.me		= THIS_MODULE,
};

static int __init init(void)
{
	int ret;
	need_conntrack();

	ret = xt_register_match(AF_INET, &helper_match);
	if (ret < 0)
		return ret;

	ret = xt_register_match(AF_INET6, &helper6_match);
	if (ret < 0)
		xt_unregister_match(AF_INET, &helper_match);

	return ret;
}

static void __exit fini(void)
{
	xt_unregister_match(AF_INET, &helper_match);
	xt_unregister_match(AF_INET6, &helper6_match);
}

module_init(init);
module_exit(fini);
Commit	Line	Data
1da177e4 LT	1	/* iptables module to match on related connections */
	2	/*
	3	* (C) 2001 Martin Josefsson <gandalf@wlug.westbo.se>
	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.
	8	*
	9	* 19 Mar 2002 Harald Welte <laforge@gnumonks.org>:
	10	* - Port to newnat infrastructure
	11	*/
	12
	13	#include <linux/module.h>
	14	#include <linux/skbuff.h>
	15	#include <linux/netfilter.h>
9fb9cbb1	16	#if defined(CONFIG_IP_NF_CONNTRACK) \|\| defined(CONFIG_IP_NF_CONNTRACK_MODULE)
1da177e4 LT	17	#include <linux/netfilter_ipv4/ip_conntrack.h>
	18	#include <linux/netfilter_ipv4/ip_conntrack_core.h>
	19	#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
9fb9cbb1 YK	20	#else
	21	#include <net/netfilter/nf_conntrack.h>
	22	#include <net/netfilter/nf_conntrack_core.h>
	23	#include <net/netfilter/nf_conntrack_helper.h>
	24	#endif
2e4e6a17 HW	25	#include <linux/netfilter/x_tables.h>
2e4e6a17 HW	26	#include <linux/netfilter/xt_helper.h>
1da177e4 LT	27
	28	MODULE_LICENSE("GPL");
	29	MODULE_AUTHOR("Martin Josefsson <gandalf@netfilter.org>");
	30	MODULE_DESCRIPTION("iptables helper match module");
2e4e6a17 HW	31	MODULE_ALIAS("ipt_helper");
2e4e6a17 HW	32	MODULE_ALIAS("ip6t_helper");
1da177e4 LT	33
	34	#if 0
	35	#define DEBUGP printk
	36	#else
	37	#define DEBUGP(format, args...)
	38	#endif
	39
9fb9cbb1	40	#if defined(CONFIG_IP_NF_CONNTRACK) \|\| defined(CONFIG_IP_NF_CONNTRACK_MODULE)
1da177e4 LT	41	static int
	42	match(const struct sk_buff *skb,
	43	const struct net_device *in,
	44	const struct net_device *out,
	45	const void *matchinfo,
	46	int offset,
2e4e6a17	47	unsigned int protoff,
1da177e4 LT	48	int *hotdrop)
1da177e4 LT	49	{
2e4e6a17	50	const struct xt_helper_info *info = matchinfo;
1da177e4 LT	51	struct ip_conntrack *ct;
	52	enum ip_conntrack_info ctinfo;
	53	int ret = info->invert;
	54
	55	ct = ip_conntrack_get((struct sk_buff *)skb, &ctinfo);
	56	if (!ct) {
2e4e6a17	57	DEBUGP("xt_helper: Eek! invalid conntrack?\n");
1da177e4 LT	58	return ret;
	59	}
	60
	61	if (!ct->master) {
2e4e6a17	62	DEBUGP("xt_helper: conntrack %p has no master\n", ct);
1da177e4 LT	63	return ret;
	64	}
	65
e45b1be8	66	read_lock_bh(&ip_conntrack_lock);
1da177e4	67	if (!ct->master->helper) {
2e4e6a17	68	DEBUGP("xt_helper: master ct %p has no helper\n",
1da177e4 LT	69	exp->expectant);
	70	goto out_unlock;
	71	}
	72
	73	DEBUGP("master's name = %s , info->name = %s\n",
	74	ct->master->helper->name, info->name);
	75
	76	if (info->name[0] == '\0')
	77	ret ^= 1;
	78	else
	79	ret ^= !strncmp(ct->master->helper->name, info->name,
	80	strlen(ct->master->helper->name));
	81	out_unlock:
e45b1be8	82	read_unlock_bh(&ip_conntrack_lock);
1da177e4 LT	83	return ret;
	84	}
	85
9fb9cbb1 YK	86	#else /* CONFIG_IP_NF_CONNTRACK */
	87
	88	static int
	89	match(const struct sk_buff *skb,
	90	const struct net_device *in,
	91	const struct net_device *out,
	92	const void *matchinfo,
	93	int offset,
2e4e6a17	94	unsigned int protoff,
9fb9cbb1 YK	95	int *hotdrop)
9fb9cbb1 YK	96	{
2e4e6a17	97	const struct xt_helper_info *info = matchinfo;
9fb9cbb1 YK	98	struct nf_conn *ct;
	99	enum ip_conntrack_info ctinfo;
	100	int ret = info->invert;
	101
	102	ct = nf_ct_get((struct sk_buff *)skb, &ctinfo);
	103	if (!ct) {
2e4e6a17	104	DEBUGP("xt_helper: Eek! invalid conntrack?\n");
9fb9cbb1 YK	105	return ret;
	106	}
	107
	108	if (!ct->master) {
2e4e6a17	109	DEBUGP("xt_helper: conntrack %p has no master\n", ct);
9fb9cbb1 YK	110	return ret;
	111	}
	112
	113	read_lock_bh(&nf_conntrack_lock);
	114	if (!ct->master->helper) {
2e4e6a17	115	DEBUGP("xt_helper: master ct %p has no helper\n",
9fb9cbb1 YK	116	exp->expectant);
	117	goto out_unlock;
	118	}
	119
	120	DEBUGP("master's name = %s , info->name = %s\n",
	121	ct->master->helper->name, info->name);
	122
	123	if (info->name[0] == '\0')
	124	ret ^= 1;
	125	else
	126	ret ^= !strncmp(ct->master->helper->name, info->name,
	127	strlen(ct->master->helper->name));
	128	out_unlock:
	129	read_unlock_bh(&nf_conntrack_lock);
	130	return ret;
	131	}
	132	#endif
	133
1da177e4	134	static int check(const char *tablename,
2e4e6a17	135	const void *inf,
1da177e4 LT	136	void *matchinfo,
	137	unsigned int matchsize,
	138	unsigned int hook_mask)
	139	{
2e4e6a17	140	struct xt_helper_info *info = matchinfo;
1da177e4 LT	141
	142	info->name[29] = '\0';
	143
	144	/* verify size */
2e4e6a17	145	if (matchsize != XT_ALIGN(sizeof(struct xt_helper_info)))
1da177e4 LT	146	return 0;
	147
	148	return 1;
	149	}
	150
2e4e6a17 HW	151	static struct xt_match helper_match = {
	152	.name = "helper",
	153	.match = &match,
	154	.checkentry = &check,
	155	.me = THIS_MODULE,
	156	};
	157	static struct xt_match helper6_match = {
1da177e4 LT	158	.name = "helper",
	159	.match = &match,
	160	.checkentry = &check,
	161	.me = THIS_MODULE,
	162	};
	163
	164	static int __init init(void)
	165	{
2e4e6a17 HW	166	int ret;
	167	need_conntrack();
	168
	169	ret = xt_register_match(AF_INET, &helper_match);
	170	if (ret < 0)
	171	return ret;
	172
	173	ret = xt_register_match(AF_INET6, &helper6_match);
	174	if (ret < 0)
	175	xt_unregister_match(AF_INET, &helper_match);
	176
	177	return ret;
1da177e4 LT	178	}
	179
	180	static void __exit fini(void)
	181	{
2e4e6a17 HW	182	xt_unregister_match(AF_INET, &helper_match);
2e4e6a17 HW	183	xt_unregister_match(AF_INET6, &helper6_match);
1da177e4 LT	184	}
	185
	186	module_init(init);
	187	module_exit(fini);
	188