[linux-block.git] / net / ipv4 / netfilter / ipt_conntrack.c

/* Kernel module to match connection tracking information.
 * Superset of Rusty's minimalistic state match.
 *
 * (C) 2001  Marc Boucher (marc@mbsi.ca).
 *
 * 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.
 */

#include <linux/module.h>
#include <linux/skbuff.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_tuple.h>
#else
#include <net/netfilter/nf_conntrack.h>
#endif

#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv4/ipt_conntrack.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
MODULE_DESCRIPTION("iptables connection tracking match module");

#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,
      int *hotdrop)
{
	const struct ipt_conntrack_info *sinfo = matchinfo;
	struct ip_conntrack *ct;
	enum ip_conntrack_info ctinfo;
	unsigned int statebit;

	ct = ip_conntrack_get((struct sk_buff *)skb, &ctinfo);

#define FWINV(bool,invflg) ((bool) ^ !!(sinfo->invflags & invflg))

	if (ct == &ip_conntrack_untracked)
		statebit = IPT_CONNTRACK_STATE_UNTRACKED;
	else if (ct)
 		statebit = IPT_CONNTRACK_STATE_BIT(ctinfo);
 	else
 		statebit = IPT_CONNTRACK_STATE_INVALID;
 
	if(sinfo->flags & IPT_CONNTRACK_STATE) {
		if (ct) {
			if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip !=
			    ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip)
				statebit |= IPT_CONNTRACK_STATE_SNAT;

			if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip !=
			    ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip)
				statebit |= IPT_CONNTRACK_STATE_DNAT;
		}

		if (FWINV((statebit & sinfo->statemask) == 0, IPT_CONNTRACK_STATE))
			return 0;
	}

	if(sinfo->flags & IPT_CONNTRACK_PROTO) {
		if (!ct || FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum, IPT_CONNTRACK_PROTO))
                	return 0;
	}

	if(sinfo->flags & IPT_CONNTRACK_ORIGSRC) {
		if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip&sinfo->sipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip, IPT_CONNTRACK_ORIGSRC))
			return 0;
	}

	if(sinfo->flags & IPT_CONNTRACK_ORIGDST) {
		if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip&sinfo->dipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip, IPT_CONNTRACK_ORIGDST))
			return 0;
	}

	if(sinfo->flags & IPT_CONNTRACK_REPLSRC) {
		if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip&sinfo->sipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].src.ip, IPT_CONNTRACK_REPLSRC))
			return 0;
	}

	if(sinfo->flags & IPT_CONNTRACK_REPLDST) {
		if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip&sinfo->dipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].dst.ip, IPT_CONNTRACK_REPLDST))
			return 0;
	}

	if(sinfo->flags & IPT_CONNTRACK_STATUS) {
		if (!ct || FWINV((ct->status & sinfo->statusmask) == 0, IPT_CONNTRACK_STATUS))
			return 0;
	}

	if(sinfo->flags & IPT_CONNTRACK_EXPIRES) {
		unsigned long expires;

		if(!ct)
			return 0;

		expires = timer_pending(&ct->timeout) ? (ct->timeout.expires - jiffies)/HZ : 0;

		if (FWINV(!(expires >= sinfo->expires_min && expires <= sinfo->expires_max), IPT_CONNTRACK_EXPIRES))
			return 0;
	}

	return 1;
}

#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,
      int *hotdrop)
{
	const struct ipt_conntrack_info *sinfo = matchinfo;
	struct nf_conn *ct;
	enum ip_conntrack_info ctinfo;
	unsigned int statebit;

	ct = nf_ct_get((struct sk_buff *)skb, &ctinfo);

#define FWINV(bool,invflg) ((bool) ^ !!(sinfo->invflags & invflg))

	if (ct == &nf_conntrack_untracked)
		statebit = IPT_CONNTRACK_STATE_UNTRACKED;
	else if (ct)
 		statebit = IPT_CONNTRACK_STATE_BIT(ctinfo);
 	else
 		statebit = IPT_CONNTRACK_STATE_INVALID;
 
	if(sinfo->flags & IPT_CONNTRACK_STATE) {
		if (ct) {
			if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip !=
			    ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip)
				statebit |= IPT_CONNTRACK_STATE_SNAT;

			if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip !=
			    ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip)
				statebit |= IPT_CONNTRACK_STATE_DNAT;
		}

		if (FWINV((statebit & sinfo->statemask) == 0, IPT_CONNTRACK_STATE))
			return 0;
	}

	if(sinfo->flags & IPT_CONNTRACK_PROTO) {
		if (!ct || FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum, IPT_CONNTRACK_PROTO))
                	return 0;
	}

	if(sinfo->flags & IPT_CONNTRACK_ORIGSRC) {
		if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip&sinfo->sipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip, IPT_CONNTRACK_ORIGSRC))
			return 0;
	}

	if(sinfo->flags & IPT_CONNTRACK_ORIGDST) {
		if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip&sinfo->dipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip, IPT_CONNTRACK_ORIGDST))
			return 0;
	}

	if(sinfo->flags & IPT_CONNTRACK_REPLSRC) {
		if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip&sinfo->sipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].src.ip, IPT_CONNTRACK_REPLSRC))
			return 0;
	}

	if(sinfo->flags & IPT_CONNTRACK_REPLDST) {
		if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip&sinfo->dipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].dst.ip, IPT_CONNTRACK_REPLDST))
			return 0;
	}

	if(sinfo->flags & IPT_CONNTRACK_STATUS) {
		if (!ct || FWINV((ct->status & sinfo->statusmask) == 0, IPT_CONNTRACK_STATUS))
			return 0;
	}

	if(sinfo->flags & IPT_CONNTRACK_EXPIRES) {
		unsigned long expires;

		if(!ct)
			return 0;

		expires = timer_pending(&ct->timeout) ? (ct->timeout.expires - jiffies)/HZ : 0;

		if (FWINV(!(expires >= sinfo->expires_min && expires <= sinfo->expires_max), IPT_CONNTRACK_EXPIRES))
			return 0;
	}

	return 1;
}

#endif /* CONFIG_NF_IP_CONNTRACK */

static int check(const char *tablename,
		 const struct ipt_ip *ip,
		 void *matchinfo,
		 unsigned int matchsize,
		 unsigned int hook_mask)
{
	if (matchsize != IPT_ALIGN(sizeof(struct ipt_conntrack_info)))
		return 0;

	return 1;
}

static struct ipt_match conntrack_match = {
	.name		= "conntrack",
	.match		= &match,
	.checkentry	= &check,
	.me		= THIS_MODULE,
};

static int __init init(void)
{
	need_ip_conntrack();
	return ipt_register_match(&conntrack_match);
}

static void __exit fini(void)
{
	ipt_unregister_match(&conntrack_match);
}

module_init(init);
module_exit(fini);
Commit	Line	Data
1da177e4 LT	1	/* Kernel module to match connection tracking information.
	2	* Superset of Rusty's minimalistic state match.
	3	*
	4	* (C) 2001 Marc Boucher (marc@mbsi.ca).
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
	10
	11	#include <linux/module.h>
	12	#include <linux/skbuff.h>
9fb9cbb1 YK	13
9fb9cbb1 YK	14	#if defined(CONFIG_IP_NF_CONNTRACK) \|\| defined(CONFIG_IP_NF_CONNTRACK_MODULE)
1da177e4	15	#include <linux/netfilter_ipv4/ip_conntrack.h>
9fb9cbb1 YK	16	#include <linux/netfilter_ipv4/ip_conntrack_tuple.h>
	17	#else
	18	#include <net/netfilter/nf_conntrack.h>
	19	#endif
	20
1da177e4 LT	21	#include <linux/netfilter_ipv4/ip_tables.h>
	22	#include <linux/netfilter_ipv4/ipt_conntrack.h>
	23
	24	MODULE_LICENSE("GPL");
	25	MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
	26	MODULE_DESCRIPTION("iptables connection tracking match module");
	27
9fb9cbb1 YK	28	#if defined(CONFIG_IP_NF_CONNTRACK) \|\| defined(CONFIG_IP_NF_CONNTRACK_MODULE)
9fb9cbb1 YK	29
1da177e4 LT	30	static int
	31	match(const struct sk_buff *skb,
	32	const struct net_device *in,
	33	const struct net_device *out,
	34	const void *matchinfo,
	35	int offset,
	36	int *hotdrop)
	37	{
	38	const struct ipt_conntrack_info *sinfo = matchinfo;
	39	struct ip_conntrack *ct;
	40	enum ip_conntrack_info ctinfo;
	41	unsigned int statebit;
	42
	43	ct = ip_conntrack_get((struct sk_buff *)skb, &ctinfo);
	44
	45	#define FWINV(bool,invflg) ((bool) ^ !!(sinfo->invflags & invflg))
	46
	47	if (ct == &ip_conntrack_untracked)
	48	statebit = IPT_CONNTRACK_STATE_UNTRACKED;
	49	else if (ct)
	50	statebit = IPT_CONNTRACK_STATE_BIT(ctinfo);
	51	else
	52	statebit = IPT_CONNTRACK_STATE_INVALID;
	53
	54	if(sinfo->flags & IPT_CONNTRACK_STATE) {
	55	if (ct) {
	56	if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip !=
	57	ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip)
	58	statebit \|= IPT_CONNTRACK_STATE_SNAT;
	59
	60	if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip !=
	61	ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip)
	62	statebit \|= IPT_CONNTRACK_STATE_DNAT;
	63	}
	64
	65	if (FWINV((statebit & sinfo->statemask) == 0, IPT_CONNTRACK_STATE))
	66	return 0;
	67	}
	68
	69	if(sinfo->flags & IPT_CONNTRACK_PROTO) {
	70	if (!ct \|\| FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum, IPT_CONNTRACK_PROTO))
	71	return 0;
	72	}
	73
	74	if(sinfo->flags & IPT_CONNTRACK_ORIGSRC) {
	75	if (!ct \|\| FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip&sinfo->sipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip, IPT_CONNTRACK_ORIGSRC))
	76	return 0;
	77	}
	78
	79	if(sinfo->flags & IPT_CONNTRACK_ORIGDST) {
	80	if (!ct \|\| FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip&sinfo->dipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip, IPT_CONNTRACK_ORIGDST))
	81	return 0;
	82	}
	83
	84	if(sinfo->flags & IPT_CONNTRACK_REPLSRC) {
	85	if (!ct \|\| FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip&sinfo->sipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].src.ip, IPT_CONNTRACK_REPLSRC))
	86	return 0;
	87	}
	88
	89	if(sinfo->flags & IPT_CONNTRACK_REPLDST) {
	90	if (!ct \|\| FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip&sinfo->dipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].dst.ip, IPT_CONNTRACK_REPLDST))
	91	return 0;
	92	}
	93
94	if(sinfo->flags & IPT_CONNTRACK_STATUS) {
95	if (!ct \|\| FWINV((ct->status & sinfo->statusmask) == 0, IPT_CONNTRACK_STATUS))
96	return 0;
97	}
98
99	if(sinfo->flags & IPT_CONNTRACK_EXPIRES) {
100	unsigned long expires;
101
102	if(!ct)
103	return 0;
104
105	expires = timer_pending(&ct->timeout) ? (ct->timeout.expires - jiffies)/HZ : 0;
106
107	if (FWINV(!(expires >= sinfo->expires_min && expires <= sinfo->expires_max), IPT_CONNTRACK_EXPIRES))
108	return 0;
109	}
110
111	return 1;
112	}
113
9fb9cbb1 YK	114	#else /* CONFIG_IP_NF_CONNTRACK */
	115	static int
	116	match(const struct sk_buff *skb,
	117	const struct net_device *in,
	118	const struct net_device *out,
	119	const void *matchinfo,
	120	int offset,
	121	int *hotdrop)
	122	{
	123	const struct ipt_conntrack_info *sinfo = matchinfo;
	124	struct nf_conn *ct;
	125	enum ip_conntrack_info ctinfo;
	126	unsigned int statebit;
	127
	128	ct = nf_ct_get((struct sk_buff *)skb, &ctinfo);
	129
	130	#define FWINV(bool,invflg) ((bool) ^ !!(sinfo->invflags & invflg))
	131
	132	if (ct == &nf_conntrack_untracked)
	133	statebit = IPT_CONNTRACK_STATE_UNTRACKED;
	134	else if (ct)
	135	statebit = IPT_CONNTRACK_STATE_BIT(ctinfo);
	136	else
	137	statebit = IPT_CONNTRACK_STATE_INVALID;
	138
	139	if(sinfo->flags & IPT_CONNTRACK_STATE) {
	140	if (ct) {
	141	if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip !=
	142	ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip)
	143	statebit \|= IPT_CONNTRACK_STATE_SNAT;
	144
	145	if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip !=
	146	ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip)
	147	statebit \|= IPT_CONNTRACK_STATE_DNAT;
	148	}
	149
	150	if (FWINV((statebit & sinfo->statemask) == 0, IPT_CONNTRACK_STATE))
	151	return 0;
	152	}
	153
	154	if(sinfo->flags & IPT_CONNTRACK_PROTO) {
	155	if (!ct \|\| FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum, IPT_CONNTRACK_PROTO))
	156	return 0;
	157	}
	158
	159	if(sinfo->flags & IPT_CONNTRACK_ORIGSRC) {
	160	if (!ct \|\| FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip&sinfo->sipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip, IPT_CONNTRACK_ORIGSRC))
	161	return 0;
	162	}
	163
	164	if(sinfo->flags & IPT_CONNTRACK_ORIGDST) {
	165	if (!ct \|\| FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip&sinfo->dipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip, IPT_CONNTRACK_ORIGDST))
	166	return 0;
	167	}
	168
	169	if(sinfo->flags & IPT_CONNTRACK_REPLSRC) {
	170	if (!ct \|\| FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip&sinfo->sipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].src.ip, IPT_CONNTRACK_REPLSRC))
	171	return 0;
	172	}
	173
	174	if(sinfo->flags & IPT_CONNTRACK_REPLDST) {
	175	if (!ct \|\| FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip&sinfo->dipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].dst.ip, IPT_CONNTRACK_REPLDST))
	176	return 0;
	177	}
178
179	if(sinfo->flags & IPT_CONNTRACK_STATUS) {
180	if (!ct \|\| FWINV((ct->status & sinfo->statusmask) == 0, IPT_CONNTRACK_STATUS))
181	return 0;
182	}
183
184	if(sinfo->flags & IPT_CONNTRACK_EXPIRES) {
185	unsigned long expires;
186
187	if(!ct)
188	return 0;
189
190	expires = timer_pending(&ct->timeout) ? (ct->timeout.expires - jiffies)/HZ : 0;
191
192	if (FWINV(!(expires >= sinfo->expires_min && expires <= sinfo->expires_max), IPT_CONNTRACK_EXPIRES))
193	return 0;
194	}
195
196	return 1;
197	}
198
199	#endif /* CONFIG_NF_IP_CONNTRACK */
200
1da177e4 LT	201	static int check(const char *tablename,
	202	const struct ipt_ip *ip,
	203	void *matchinfo,
	204	unsigned int matchsize,
	205	unsigned int hook_mask)
	206	{
	207	if (matchsize != IPT_ALIGN(sizeof(struct ipt_conntrack_info)))
	208	return 0;
	209
	210	return 1;
	211	}
	212
	213	static struct ipt_match conntrack_match = {
	214	.name = "conntrack",
	215	.match = &match,
	216	.checkentry = &check,
	217	.me = THIS_MODULE,
	218	};
	219
	220	static int __init init(void)
	221	{
	222	need_ip_conntrack();
	223	return ipt_register_match(&conntrack_match);
	224	}
	225
	226	static void __exit fini(void)
	227	{
	228	ipt_unregister_match(&conntrack_match);
	229	}
	230
	231	module_init(init);
	232	module_exit(fini);