[mirror_ubuntu-zesty-kernel.git] / net / netfilter / xt_conntrack.c

/*
 *	xt_conntrack - Netfilter module to match connection tracking
 *	information. (Superset of Rusty's minimalistic state match.)
 *
 *	(C) 2001  Marc Boucher (marc@mbsi.ca).
 *	Copyright © CC Computer Consultants GmbH, 2007 - 2008
 *
 *	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>
#include <net/ipv6.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_conntrack.h>
#include <net/netfilter/nf_conntrack.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
MODULE_DESCRIPTION("Xtables: connection tracking state match");
MODULE_ALIAS("ipt_conntrack");
MODULE_ALIAS("ip6t_conntrack");

static bool
conntrack_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par)
{
	const struct xt_conntrack_info *sinfo = par->matchinfo;
	const struct nf_conn *ct;
	enum ip_conntrack_info ctinfo;
	unsigned int statebit;

	ct = nf_ct_get(skb, &ctinfo);

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

	if (ct == &nf_conntrack_untracked)
		statebit = XT_CONNTRACK_STATE_UNTRACKED;
	else if (ct)
		statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
	else
		statebit = XT_CONNTRACK_STATE_INVALID;

	if (sinfo->flags & XT_CONNTRACK_STATE) {
		if (ct) {
			if (test_bit(IPS_SRC_NAT_BIT, &ct->status))
				statebit |= XT_CONNTRACK_STATE_SNAT;
			if (test_bit(IPS_DST_NAT_BIT, &ct->status))
				statebit |= XT_CONNTRACK_STATE_DNAT;
		}
		if (FWINV((statebit & sinfo->statemask) == 0,
			  XT_CONNTRACK_STATE))
			return false;
	}

	if (ct == NULL) {
		if (sinfo->flags & ~XT_CONNTRACK_STATE)
			return false;
		return true;
	}

	if (sinfo->flags & XT_CONNTRACK_PROTO &&
	    FWINV(nf_ct_protonum(ct) !=
		  sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum,
		  XT_CONNTRACK_PROTO))
		return false;

	if (sinfo->flags & XT_CONNTRACK_ORIGSRC &&
	    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,
		  XT_CONNTRACK_ORIGSRC))
		return false;

	if (sinfo->flags & XT_CONNTRACK_ORIGDST &&
	    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,
		  XT_CONNTRACK_ORIGDST))
		return false;

	if (sinfo->flags & XT_CONNTRACK_REPLSRC &&
	    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,
		  XT_CONNTRACK_REPLSRC))
		return false;

	if (sinfo->flags & XT_CONNTRACK_REPLDST &&
	    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,
		  XT_CONNTRACK_REPLDST))
		return false;

	if (sinfo->flags & XT_CONNTRACK_STATUS &&
	    FWINV((ct->status & sinfo->statusmask) == 0,
		  XT_CONNTRACK_STATUS))
		return false;

	if(sinfo->flags & XT_CONNTRACK_EXPIRES) {
		unsigned long expires = timer_pending(&ct->timeout) ?
					(ct->timeout.expires - jiffies)/HZ : 0;

		if (FWINV(!(expires >= sinfo->expires_min &&
			    expires <= sinfo->expires_max),
			  XT_CONNTRACK_EXPIRES))
			return false;
	}
	return true;
#undef FWINV
}

static bool
conntrack_addrcmp(const union nf_inet_addr *kaddr,
                  const union nf_inet_addr *uaddr,
                  const union nf_inet_addr *umask, unsigned int l3proto)
{
	if (l3proto == NFPROTO_IPV4)
		return ((kaddr->ip ^ uaddr->ip) & umask->ip) == 0;
	else if (l3proto == NFPROTO_IPV6)
		return ipv6_masked_addr_cmp(&kaddr->in6, &umask->in6,
		       &uaddr->in6) == 0;
	else
		return false;
}

static inline bool
conntrack_mt_origsrc(const struct nf_conn *ct,
                     const struct xt_conntrack_mtinfo2 *info,
		     u_int8_t family)
{
	return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3,
	       &info->origsrc_addr, &info->origsrc_mask, family);
}

static inline bool
conntrack_mt_origdst(const struct nf_conn *ct,
                     const struct xt_conntrack_mtinfo2 *info,
		     u_int8_t family)
{
	return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3,
	       &info->origdst_addr, &info->origdst_mask, family);
}

static inline bool
conntrack_mt_replsrc(const struct nf_conn *ct,
                     const struct xt_conntrack_mtinfo2 *info,
		     u_int8_t family)
{
	return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3,
	       &info->replsrc_addr, &info->replsrc_mask, family);
}

static inline bool
conntrack_mt_repldst(const struct nf_conn *ct,
                     const struct xt_conntrack_mtinfo2 *info,
		     u_int8_t family)
{
	return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3,
	       &info->repldst_addr, &info->repldst_mask, family);
}

static inline bool
ct_proto_port_check(const struct xt_conntrack_mtinfo2 *info,
                    const struct nf_conn *ct)
{
	const struct nf_conntrack_tuple *tuple;

	tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
	if ((info->match_flags & XT_CONNTRACK_PROTO) &&
	    (nf_ct_protonum(ct) == info->l4proto) ^
	    !(info->invert_flags & XT_CONNTRACK_PROTO))
		return false;

	/* Shortcut to match all recognized protocols by using ->src.all. */
	if ((info->match_flags & XT_CONNTRACK_ORIGSRC_PORT) &&
	    (tuple->src.u.all == info->origsrc_port) ^
	    !(info->invert_flags & XT_CONNTRACK_ORIGSRC_PORT))
		return false;

	if ((info->match_flags & XT_CONNTRACK_ORIGDST_PORT) &&
	    (tuple->dst.u.all == info->origdst_port) ^
	    !(info->invert_flags & XT_CONNTRACK_ORIGDST_PORT))
		return false;

	tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple;

	if ((info->match_flags & XT_CONNTRACK_REPLSRC_PORT) &&
	    (tuple->src.u.all == info->replsrc_port) ^
	    !(info->invert_flags & XT_CONNTRACK_REPLSRC_PORT))
		return false;

	if ((info->match_flags & XT_CONNTRACK_REPLDST_PORT) &&
	    (tuple->dst.u.all == info->repldst_port) ^
	    !(info->invert_flags & XT_CONNTRACK_REPLDST_PORT))
		return false;

	return true;
}

static bool
conntrack_mt(const struct sk_buff *skb, const struct xt_match_param *par)
{
	const struct xt_conntrack_mtinfo2 *info = par->matchinfo;
	enum ip_conntrack_info ctinfo;
	const struct nf_conn *ct;
	unsigned int statebit;

	ct = nf_ct_get(skb, &ctinfo);

	if (ct == &nf_conntrack_untracked)
		statebit = XT_CONNTRACK_STATE_UNTRACKED;
	else if (ct != NULL)
		statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
	else
		statebit = XT_CONNTRACK_STATE_INVALID;

	if (info->match_flags & XT_CONNTRACK_STATE) {
		if (ct != NULL) {
			if (test_bit(IPS_SRC_NAT_BIT, &ct->status))
				statebit |= XT_CONNTRACK_STATE_SNAT;
			if (test_bit(IPS_DST_NAT_BIT, &ct->status))
				statebit |= XT_CONNTRACK_STATE_DNAT;
		}
		if (!!(info->state_mask & statebit) ^
		    !(info->invert_flags & XT_CONNTRACK_STATE))
			return false;
	}

	if (ct == NULL)
		return info->match_flags & XT_CONNTRACK_STATE;
	if ((info->match_flags & XT_CONNTRACK_DIRECTION) &&
	    (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) ^
	    !!(info->invert_flags & XT_CONNTRACK_DIRECTION))
		return false;

	if (info->match_flags & XT_CONNTRACK_ORIGSRC)
		if (conntrack_mt_origsrc(ct, info, par->family) ^
		    !(info->invert_flags & XT_CONNTRACK_ORIGSRC))
			return false;

	if (info->match_flags & XT_CONNTRACK_ORIGDST)
		if (conntrack_mt_origdst(ct, info, par->family) ^
		    !(info->invert_flags & XT_CONNTRACK_ORIGDST))
			return false;

	if (info->match_flags & XT_CONNTRACK_REPLSRC)
		if (conntrack_mt_replsrc(ct, info, par->family) ^
		    !(info->invert_flags & XT_CONNTRACK_REPLSRC))
			return false;

	if (info->match_flags & XT_CONNTRACK_REPLDST)
		if (conntrack_mt_repldst(ct, info, par->family) ^
		    !(info->invert_flags & XT_CONNTRACK_REPLDST))
			return false;

	if (!ct_proto_port_check(info, ct))
		return false;

	if ((info->match_flags & XT_CONNTRACK_STATUS) &&
	    (!!(info->status_mask & ct->status) ^
	    !(info->invert_flags & XT_CONNTRACK_STATUS)))
		return false;

	if (info->match_flags & XT_CONNTRACK_EXPIRES) {
		unsigned long expires = 0;

		if (timer_pending(&ct->timeout))
			expires = (ct->timeout.expires - jiffies) / HZ;
		if ((expires >= info->expires_min &&
		    expires <= info->expires_max) ^
		    !(info->invert_flags & XT_CONNTRACK_EXPIRES))
			return false;
	}
	return true;
}

static bool
conntrack_mt_v1(const struct sk_buff *skb, const struct xt_match_param *par)
{
	const struct xt_conntrack_mtinfo2 *const *info = par->matchinfo;
	struct xt_match_param newpar = *par;

	newpar.matchinfo = *info;
	return conntrack_mt(skb, &newpar);
}

static bool conntrack_mt_check(const struct xt_mtchk_param *par)
{
	if (nf_ct_l3proto_try_module_get(par->family) < 0) {
		printk(KERN_WARNING "can't load conntrack support for "
				    "proto=%u\n", par->family);
		return false;
	}
	return true;
}

static bool conntrack_mt_check_v1(const struct xt_mtchk_param *par)
{
	struct xt_conntrack_mtinfo1 *info = par->matchinfo;
	struct xt_conntrack_mtinfo2 *up;
	int ret = conntrack_mt_check(par);

	if (ret < 0)
		return ret;

	up = kmalloc(sizeof(*up), GFP_KERNEL);
	if (up == NULL) {
		nf_ct_l3proto_module_put(par->family);
		return -ENOMEM;
	}

	/*
	 * The strategy here is to minimize the overhead of v1 matching,
	 * by prebuilding a v2 struct and putting the pointer into the
	 * v1 dataspace.
	 */
	memcpy(up, info, offsetof(typeof(*info), state_mask));
	up->state_mask  = info->state_mask;
	up->status_mask = info->status_mask;
	*(void **)info  = up;
	return true;
}

static void conntrack_mt_destroy(const struct xt_mtdtor_param *par)
{
	nf_ct_l3proto_module_put(par->family);
}

static void conntrack_mt_destroy_v1(const struct xt_mtdtor_param *par)
{
	struct xt_conntrack_mtinfo2 **info = par->matchinfo;
	kfree(*info);
	conntrack_mt_destroy(par);
}

#ifdef CONFIG_COMPAT
struct compat_xt_conntrack_info
{
	compat_uint_t			statemask;
	compat_uint_t			statusmask;
	struct ip_conntrack_old_tuple	tuple[IP_CT_DIR_MAX];
	struct in_addr			sipmsk[IP_CT_DIR_MAX];
	struct in_addr			dipmsk[IP_CT_DIR_MAX];
	compat_ulong_t			expires_min;
	compat_ulong_t			expires_max;
	u_int8_t			flags;
	u_int8_t			invflags;
};

static void conntrack_mt_compat_from_user_v0(void *dst, void *src)
{
	const struct compat_xt_conntrack_info *cm = src;
	struct xt_conntrack_info m = {
		.statemask	= cm->statemask,
		.statusmask	= cm->statusmask,
		.expires_min	= cm->expires_min,
		.expires_max	= cm->expires_max,
		.flags		= cm->flags,
		.invflags	= cm->invflags,
	};
	memcpy(m.tuple, cm->tuple, sizeof(m.tuple));
	memcpy(m.sipmsk, cm->sipmsk, sizeof(m.sipmsk));
	memcpy(m.dipmsk, cm->dipmsk, sizeof(m.dipmsk));
	memcpy(dst, &m, sizeof(m));
}

static int conntrack_mt_compat_to_user_v0(void __user *dst, void *src)
{
	const struct xt_conntrack_info *m = src;
	struct compat_xt_conntrack_info cm = {
		.statemask	= m->statemask,
		.statusmask	= m->statusmask,
		.expires_min	= m->expires_min,
		.expires_max	= m->expires_max,
		.flags		= m->flags,
		.invflags	= m->invflags,
	};
	memcpy(cm.tuple, m->tuple, sizeof(cm.tuple));
	memcpy(cm.sipmsk, m->sipmsk, sizeof(cm.sipmsk));
	memcpy(cm.dipmsk, m->dipmsk, sizeof(cm.dipmsk));
	return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0;
}
#endif

static struct xt_match conntrack_mt_reg[] __read_mostly = {
	{
		.name       = "conntrack",
		.revision   = 0,
		.family     = NFPROTO_IPV4,
		.match      = conntrack_mt_v0,
		.checkentry = conntrack_mt_check,
		.destroy    = conntrack_mt_destroy,
		.matchsize  = sizeof(struct xt_conntrack_info),
		.me         = THIS_MODULE,
#ifdef CONFIG_COMPAT
		.compatsize       = sizeof(struct compat_xt_conntrack_info),
		.compat_from_user = conntrack_mt_compat_from_user_v0,
		.compat_to_user   = conntrack_mt_compat_to_user_v0,
#endif
	},
	{
		.name       = "conntrack",
		.revision   = 1,
		.family     = NFPROTO_UNSPEC,
		.matchsize  = sizeof(struct xt_conntrack_mtinfo1),
		.match      = conntrack_mt_v1,
		.checkentry = conntrack_mt_check_v1,
		.destroy    = conntrack_mt_destroy_v1,
		.me         = THIS_MODULE,
	},
	{
		.name       = "conntrack",
		.revision   = 2,
		.family     = NFPROTO_UNSPEC,
		.matchsize  = sizeof(struct xt_conntrack_mtinfo2),
		.match      = conntrack_mt,
		.checkentry = conntrack_mt_check,
		.destroy    = conntrack_mt_destroy,
		.me         = THIS_MODULE,
	},
};

static int __init conntrack_mt_init(void)
{
	return xt_register_matches(conntrack_mt_reg,
	       ARRAY_SIZE(conntrack_mt_reg));
}

static void __exit conntrack_mt_exit(void)
{
	xt_unregister_matches(conntrack_mt_reg, ARRAY_SIZE(conntrack_mt_reg));
}

module_init(conntrack_mt_init);
module_exit(conntrack_mt_exit);
Commit	Line	Data
64eb12f9 JE	1	/*
	2	* xt_conntrack - Netfilter module to match connection tracking
	3	* information. (Superset of Rusty's minimalistic state match.)
1da177e4	4	*
64eb12f9 JE	5	* (C) 2001 Marc Boucher (marc@mbsi.ca).
64eb12f9 JE	6	* Copyright © CC Computer Consultants GmbH, 2007 - 2008
1da177e4	7	*
64eb12f9 JE	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
1da177e4 LT	11	*/
	12
	13	#include <linux/module.h>
	14	#include <linux/skbuff.h>
64eb12f9	15	#include <net/ipv6.h>
2e4e6a17 HW	16	#include <linux/netfilter/x_tables.h>
2e4e6a17 HW	17	#include <linux/netfilter/xt_conntrack.h>
587aa641	18	#include <net/netfilter/nf_conntrack.h>
1da177e4 LT	19
	20	MODULE_LICENSE("GPL");
	21	MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
b4164998	22	MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
2ae15b64	23	MODULE_DESCRIPTION("Xtables: connection tracking state match");
2e4e6a17	24	MODULE_ALIAS("ipt_conntrack");
64eb12f9	25	MODULE_ALIAS("ip6t_conntrack");
1da177e4	26
1d93a9cb	27	static bool
f7108a20	28	conntrack_mt_v0(const struct sk_buff skb, const struct xt_match_param par)
9fb9cbb1	29	{
f7108a20	30	const struct xt_conntrack_info *sinfo = par->matchinfo;
a47362a2	31	const struct nf_conn *ct;
9fb9cbb1 YK	32	enum ip_conntrack_info ctinfo;
	33	unsigned int statebit;
	34
a47362a2	35	ct = nf_ct_get(skb, &ctinfo);
9fb9cbb1	36
e79ec50b	37	#define FWINV(bool, invflg) ((bool) ^ !!(sinfo->invflags & (invflg)))
9fb9cbb1 YK	38
9fb9cbb1 YK	39	if (ct == &nf_conntrack_untracked)
2e4e6a17	40	statebit = XT_CONNTRACK_STATE_UNTRACKED;
9fb9cbb1	41	else if (ct)
601e68e1 YH	42	statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
	43	else
	44	statebit = XT_CONNTRACK_STATE_INVALID;
	45
50b9f1d5	46	if (sinfo->flags & XT_CONNTRACK_STATE) {
9fb9cbb1	47	if (ct) {
50b9f1d5	48	if (test_bit(IPS_SRC_NAT_BIT, &ct->status))
2e4e6a17	49	statebit \|= XT_CONNTRACK_STATE_SNAT;
50b9f1d5	50	if (test_bit(IPS_DST_NAT_BIT, &ct->status))
2e4e6a17	51	statebit \|= XT_CONNTRACK_STATE_DNAT;
9fb9cbb1	52	}
50b9f1d5 PM	53	if (FWINV((statebit & sinfo->statemask) == 0,
50b9f1d5 PM	54	XT_CONNTRACK_STATE))
1d93a9cb	55	return false;
9fb9cbb1 YK	56	}
9fb9cbb1 YK	57
50b9f1d5 PM	58	if (ct == NULL) {
50b9f1d5 PM	59	if (sinfo->flags & ~XT_CONNTRACK_STATE)
1d93a9cb JE	60	return false;
1d93a9cb JE	61	return true;
9fb9cbb1 YK	62	}
9fb9cbb1 YK	63
50b9f1d5	64	if (sinfo->flags & XT_CONNTRACK_PROTO &&
5e8fbe2a	65	FWINV(nf_ct_protonum(ct) !=
601e68e1	66	sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum,
50b9f1d5	67	XT_CONNTRACK_PROTO))
1d93a9cb	68	return false;
50b9f1d5 PM	69
	70	if (sinfo->flags & XT_CONNTRACK_ORIGSRC &&
	71	FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip &
601e68e1	72	sinfo->sipmsk[IP_CT_DIR_ORIGINAL].s_addr) !=
50b9f1d5 PM	73	sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip,
50b9f1d5 PM	74	XT_CONNTRACK_ORIGSRC))
1d93a9cb	75	return false;
9fb9cbb1	76
50b9f1d5 PM	77	if (sinfo->flags & XT_CONNTRACK_ORIGDST &&
50b9f1d5 PM	78	FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip &
601e68e1	79	sinfo->dipmsk[IP_CT_DIR_ORIGINAL].s_addr) !=
50b9f1d5 PM	80	sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip,
50b9f1d5 PM	81	XT_CONNTRACK_ORIGDST))
1d93a9cb	82	return false;
9fb9cbb1	83
50b9f1d5 PM	84	if (sinfo->flags & XT_CONNTRACK_REPLSRC &&
50b9f1d5 PM	85	FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip &
601e68e1	86	sinfo->sipmsk[IP_CT_DIR_REPLY].s_addr) !=
50b9f1d5 PM	87	sinfo->tuple[IP_CT_DIR_REPLY].src.ip,
50b9f1d5 PM	88	XT_CONNTRACK_REPLSRC))
1d93a9cb	89	return false;
9fb9cbb1	90
50b9f1d5 PM	91	if (sinfo->flags & XT_CONNTRACK_REPLDST &&
50b9f1d5 PM	92	FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip &
601e68e1	93	sinfo->dipmsk[IP_CT_DIR_REPLY].s_addr) !=
50b9f1d5 PM	94	sinfo->tuple[IP_CT_DIR_REPLY].dst.ip,
50b9f1d5 PM	95	XT_CONNTRACK_REPLDST))
1d93a9cb	96	return false;
9fb9cbb1	97
50b9f1d5 PM	98	if (sinfo->flags & XT_CONNTRACK_STATUS &&
50b9f1d5 PM	99	FWINV((ct->status & sinfo->statusmask) == 0,
601e68e1	100	XT_CONNTRACK_STATUS))
1d93a9cb	101	return false;
9fb9cbb1	102
50b9f1d5 PM	103	if(sinfo->flags & XT_CONNTRACK_EXPIRES) {
	104	unsigned long expires = timer_pending(&ct->timeout) ?
	105	(ct->timeout.expires - jiffies)/HZ : 0;
9fb9cbb1	106
50b9f1d5 PM	107	if (FWINV(!(expires >= sinfo->expires_min &&
	108	expires <= sinfo->expires_max),
	109	XT_CONNTRACK_EXPIRES))
1d93a9cb	110	return false;
9fb9cbb1	111	}
1d93a9cb	112	return true;
e79ec50b	113	#undef FWINV
9fb9cbb1 YK	114	}
9fb9cbb1 YK	115
64eb12f9 JE	116	static bool
	117	conntrack_addrcmp(const union nf_inet_addr *kaddr,
	118	const union nf_inet_addr *uaddr,
	119	const union nf_inet_addr *umask, unsigned int l3proto)
	120	{
ee999d8b	121	if (l3proto == NFPROTO_IPV4)
6556874d	122	return ((kaddr->ip ^ uaddr->ip) & umask->ip) == 0;
ee999d8b	123	else if (l3proto == NFPROTO_IPV6)
64eb12f9 JE	124	return ipv6_masked_addr_cmp(&kaddr->in6, &umask->in6,
	125	&uaddr->in6) == 0;
	126	else
	127	return false;
	128	}
	129
	130	static inline bool
	131	conntrack_mt_origsrc(const struct nf_conn *ct,
d6d3f08b	132	const struct xt_conntrack_mtinfo2 *info,
76108cea	133	u_int8_t family)
64eb12f9 JE	134	{
	135	return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3,
	136	&info->origsrc_addr, &info->origsrc_mask, family);
	137	}
	138
	139	static inline bool
	140	conntrack_mt_origdst(const struct nf_conn *ct,
d6d3f08b	141	const struct xt_conntrack_mtinfo2 *info,
76108cea	142	u_int8_t family)
64eb12f9 JE	143	{
	144	return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3,
	145	&info->origdst_addr, &info->origdst_mask, family);
	146	}
	147
	148	static inline bool
	149	conntrack_mt_replsrc(const struct nf_conn *ct,
d6d3f08b	150	const struct xt_conntrack_mtinfo2 *info,
76108cea	151	u_int8_t family)
64eb12f9 JE	152	{
	153	return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3,
	154	&info->replsrc_addr, &info->replsrc_mask, family);
	155	}
	156
	157	static inline bool
	158	conntrack_mt_repldst(const struct nf_conn *ct,
d6d3f08b	159	const struct xt_conntrack_mtinfo2 *info,
76108cea	160	u_int8_t family)
64eb12f9 JE	161	{
	162	return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3,
	163	&info->repldst_addr, &info->repldst_mask, family);
	164	}
	165
b4164998	166	static inline bool
d6d3f08b	167	ct_proto_port_check(const struct xt_conntrack_mtinfo2 *info,
b4164998 JE	168	const struct nf_conn *ct)
	169	{
	170	const struct nf_conntrack_tuple *tuple;
	171
	172	tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
	173	if ((info->match_flags & XT_CONNTRACK_PROTO) &&
5e8fbe2a	174	(nf_ct_protonum(ct) == info->l4proto) ^
b4164998 JE	175	!(info->invert_flags & XT_CONNTRACK_PROTO))
	176	return false;
	177
	178	/* Shortcut to match all recognized protocols by using ->src.all. */
	179	if ((info->match_flags & XT_CONNTRACK_ORIGSRC_PORT) &&
	180	(tuple->src.u.all == info->origsrc_port) ^
	181	!(info->invert_flags & XT_CONNTRACK_ORIGSRC_PORT))
	182	return false;
	183
	184	if ((info->match_flags & XT_CONNTRACK_ORIGDST_PORT) &&
	185	(tuple->dst.u.all == info->origdst_port) ^
	186	!(info->invert_flags & XT_CONNTRACK_ORIGDST_PORT))
	187	return false;
	188
	189	tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple;
	190
	191	if ((info->match_flags & XT_CONNTRACK_REPLSRC_PORT) &&
	192	(tuple->src.u.all == info->replsrc_port) ^
	193	!(info->invert_flags & XT_CONNTRACK_REPLSRC_PORT))
	194	return false;
	195
	196	if ((info->match_flags & XT_CONNTRACK_REPLDST_PORT) &&
	197	(tuple->dst.u.all == info->repldst_port) ^
	198	!(info->invert_flags & XT_CONNTRACK_REPLDST_PORT))
	199	return false;
	200
	201	return true;
	202	}
	203
64eb12f9	204	static bool
f7108a20	205	conntrack_mt(const struct sk_buff skb, const struct xt_match_param par)
64eb12f9	206	{
d6d3f08b	207	const struct xt_conntrack_mtinfo2 *info = par->matchinfo;
64eb12f9 JE	208	enum ip_conntrack_info ctinfo;
	209	const struct nf_conn *ct;
	210	unsigned int statebit;
	211
	212	ct = nf_ct_get(skb, &ctinfo);
	213
	214	if (ct == &nf_conntrack_untracked)
	215	statebit = XT_CONNTRACK_STATE_UNTRACKED;
	216	else if (ct != NULL)
	217	statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
	218	else
	219	statebit = XT_CONNTRACK_STATE_INVALID;
	220
	221	if (info->match_flags & XT_CONNTRACK_STATE) {
	222	if (ct != NULL) {
	223	if (test_bit(IPS_SRC_NAT_BIT, &ct->status))
	224	statebit \|= XT_CONNTRACK_STATE_SNAT;
	225	if (test_bit(IPS_DST_NAT_BIT, &ct->status))
	226	statebit \|= XT_CONNTRACK_STATE_DNAT;
	227	}
d61f89e9	228	if (!!(info->state_mask & statebit) ^
64eb12f9 JE	229	!(info->invert_flags & XT_CONNTRACK_STATE))
	230	return false;
	231	}
	232
	233	if (ct == NULL)
	234	return info->match_flags & XT_CONNTRACK_STATE;
b4164998 JE	235	if ((info->match_flags & XT_CONNTRACK_DIRECTION) &&
	236	(CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) ^
	237	!!(info->invert_flags & XT_CONNTRACK_DIRECTION))
64eb12f9 JE	238	return false;
	239
	240	if (info->match_flags & XT_CONNTRACK_ORIGSRC)
92f3b2b1	241	if (conntrack_mt_origsrc(ct, info, par->family) ^
64eb12f9 JE	242	!(info->invert_flags & XT_CONNTRACK_ORIGSRC))
	243	return false;
	244
	245	if (info->match_flags & XT_CONNTRACK_ORIGDST)
92f3b2b1	246	if (conntrack_mt_origdst(ct, info, par->family) ^
64eb12f9 JE	247	!(info->invert_flags & XT_CONNTRACK_ORIGDST))
	248	return false;
	249
	250	if (info->match_flags & XT_CONNTRACK_REPLSRC)
92f3b2b1	251	if (conntrack_mt_replsrc(ct, info, par->family) ^
64eb12f9 JE	252	!(info->invert_flags & XT_CONNTRACK_REPLSRC))
	253	return false;
	254
	255	if (info->match_flags & XT_CONNTRACK_REPLDST)
92f3b2b1	256	if (conntrack_mt_repldst(ct, info, par->family) ^
64eb12f9 JE	257	!(info->invert_flags & XT_CONNTRACK_REPLDST))
	258	return false;
	259
b4164998 JE	260	if (!ct_proto_port_check(info, ct))
	261	return false;
	262
64eb12f9 JE	263	if ((info->match_flags & XT_CONNTRACK_STATUS) &&
	264	(!!(info->status_mask & ct->status) ^
	265	!(info->invert_flags & XT_CONNTRACK_STATUS)))
	266	return false;
	267
	268	if (info->match_flags & XT_CONNTRACK_EXPIRES) {
	269	unsigned long expires = 0;
	270
	271	if (timer_pending(&ct->timeout))
	272	expires = (ct->timeout.expires - jiffies) / HZ;
	273	if ((expires >= info->expires_min &&
	274	expires <= info->expires_max) ^
	275	!(info->invert_flags & XT_CONNTRACK_EXPIRES))
	276	return false;
	277	}
	278	return true;
	279	}
	280
d6d3f08b JE	281	static bool
	282	conntrack_mt_v1(const struct sk_buff skb, const struct xt_match_param par)
	283	{
	284	const struct xt_conntrack_mtinfo2 const info = par->matchinfo;
	285	struct xt_match_param newpar = *par;
	286
	287	newpar.matchinfo = *info;
	288	return conntrack_mt(skb, &newpar);
	289	}
	290
9b4fce7a	291	static bool conntrack_mt_check(const struct xt_mtchk_param *par)
b9f78f9f	292	{
92f3b2b1	293	if (nf_ct_l3proto_try_module_get(par->family) < 0) {
fe0b9294	294	printk(KERN_WARNING "can't load conntrack support for "
92f3b2b1	295	"proto=%u\n", par->family);
ccb79bdc	296	return false;
b9f78f9f	297	}
ccb79bdc	298	return true;
b9f78f9f PNA	299	}
b9f78f9f PNA	300
d6d3f08b JE	301	static bool conntrack_mt_check_v1(const struct xt_mtchk_param *par)
	302	{
	303	struct xt_conntrack_mtinfo1 *info = par->matchinfo;
	304	struct xt_conntrack_mtinfo2 *up;
	305	int ret = conntrack_mt_check(par);
	306
	307	if (ret < 0)
	308	return ret;
	309
	310	up = kmalloc(sizeof(*up), GFP_KERNEL);
	311	if (up == NULL) {
	312	nf_ct_l3proto_module_put(par->family);
	313	return -ENOMEM;
	314	}
	315
	316	/*
	317	* The strategy here is to minimize the overhead of v1 matching,
	318	* by prebuilding a v2 struct and putting the pointer into the
	319	* v1 dataspace.
	320	*/
	321	memcpy(up, info, offsetof(typeof(*info), state_mask));
	322	up->state_mask = info->state_mask;
	323	up->status_mask = info->status_mask;
	324	(void *)info = up;
	325	return true;
	326	}
	327
6be3d859	328	static void conntrack_mt_destroy(const struct xt_mtdtor_param *par)
b9f78f9f	329	{
92f3b2b1	330	nf_ct_l3proto_module_put(par->family);
b9f78f9f PNA	331	}
b9f78f9f PNA	332
d6d3f08b JE	333	static void conntrack_mt_destroy_v1(const struct xt_mtdtor_param *par)
	334	{
	335	struct xt_conntrack_mtinfo2 **info = par->matchinfo;
	336	kfree(*info);
	337	conntrack_mt_destroy(par);
	338	}
	339
da0dd231 PM	340	#ifdef CONFIG_COMPAT
	341	struct compat_xt_conntrack_info
	342	{
	343	compat_uint_t statemask;
	344	compat_uint_t statusmask;
	345	struct ip_conntrack_old_tuple tuple[IP_CT_DIR_MAX];
	346	struct in_addr sipmsk[IP_CT_DIR_MAX];
	347	struct in_addr dipmsk[IP_CT_DIR_MAX];
	348	compat_ulong_t expires_min;
	349	compat_ulong_t expires_max;
	350	u_int8_t flags;
	351	u_int8_t invflags;
	352	};
	353
64eb12f9	354	static void conntrack_mt_compat_from_user_v0(void dst, void src)
da0dd231	355	{
a47362a2	356	const struct compat_xt_conntrack_info *cm = src;
da0dd231 PM	357	struct xt_conntrack_info m = {
	358	.statemask = cm->statemask,
	359	.statusmask = cm->statusmask,
	360	.expires_min = cm->expires_min,
	361	.expires_max = cm->expires_max,
	362	.flags = cm->flags,
	363	.invflags = cm->invflags,
	364	};
	365	memcpy(m.tuple, cm->tuple, sizeof(m.tuple));
	366	memcpy(m.sipmsk, cm->sipmsk, sizeof(m.sipmsk));
	367	memcpy(m.dipmsk, cm->dipmsk, sizeof(m.dipmsk));
	368	memcpy(dst, &m, sizeof(m));
	369	}
	370
64eb12f9	371	static int conntrack_mt_compat_to_user_v0(void __user dst, void src)
da0dd231	372	{
a47362a2	373	const struct xt_conntrack_info *m = src;
da0dd231 PM	374	struct compat_xt_conntrack_info cm = {
	375	.statemask = m->statemask,
	376	.statusmask = m->statusmask,
	377	.expires_min = m->expires_min,
	378	.expires_max = m->expires_max,
	379	.flags = m->flags,
	380	.invflags = m->invflags,
	381	};
	382	memcpy(cm.tuple, m->tuple, sizeof(cm.tuple));
	383	memcpy(cm.sipmsk, m->sipmsk, sizeof(cm.sipmsk));
	384	memcpy(cm.dipmsk, m->dipmsk, sizeof(cm.dipmsk));
	385	return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0;
	386	}
	387	#endif
	388
64eb12f9 JE	389	static struct xt_match conntrack_mt_reg[] __read_mostly = {
	390	{
	391	.name = "conntrack",
	392	.revision = 0,
ee999d8b	393	.family = NFPROTO_IPV4,
64eb12f9 JE	394	.match = conntrack_mt_v0,
	395	.checkentry = conntrack_mt_check,
	396	.destroy = conntrack_mt_destroy,
	397	.matchsize = sizeof(struct xt_conntrack_info),
	398	.me = THIS_MODULE,
da0dd231	399	#ifdef CONFIG_COMPAT
64eb12f9 JE	400	.compatsize = sizeof(struct compat_xt_conntrack_info),
	401	.compat_from_user = conntrack_mt_compat_from_user_v0,
	402	.compat_to_user = conntrack_mt_compat_to_user_v0,
da0dd231	403	#endif
64eb12f9 JE	404	},
	405	{
	406	.name = "conntrack",
	407	.revision = 1,
92f3b2b1	408	.family = NFPROTO_UNSPEC,
64eb12f9	409	.matchsize = sizeof(struct xt_conntrack_mtinfo1),
d6d3f08b JE	410	.match = conntrack_mt_v1,
	411	.checkentry = conntrack_mt_check_v1,
	412	.destroy = conntrack_mt_destroy_v1,
	413	.me = THIS_MODULE,
	414	},
	415	{
	416	.name = "conntrack",
	417	.revision = 2,
	418	.family = NFPROTO_UNSPEC,
	419	.matchsize = sizeof(struct xt_conntrack_mtinfo2),
64eb12f9 JE	420	.match = conntrack_mt,
	421	.checkentry = conntrack_mt_check,
	422	.destroy = conntrack_mt_destroy,
	423	.me = THIS_MODULE,
	424	},
1da177e4 LT	425	};
1da177e4 LT	426
d3c5ee6d	427	static int __init conntrack_mt_init(void)
1da177e4	428	{
64eb12f9 JE	429	return xt_register_matches(conntrack_mt_reg,
64eb12f9 JE	430	ARRAY_SIZE(conntrack_mt_reg));
1da177e4 LT	431	}
1da177e4 LT	432
d3c5ee6d	433	static void __exit conntrack_mt_exit(void)
1da177e4	434	{
64eb12f9	435	xt_unregister_matches(conntrack_mt_reg, ARRAY_SIZE(conntrack_mt_reg));
1da177e4 LT	436	}
1da177e4 LT	437
d3c5ee6d JE	438	module_init(conntrack_mt_init);
d3c5ee6d JE	439	module_exit(conntrack_mt_exit);