1 files changed, 274 insertions, 153 deletions

diff --git a/net/netfilter/xt_conntrack.c b/net/netfilter/xt_conntrack.c
index ca4b69f020a..188404b9b00 100644
--- a/net/netfilter/xt_conntrack.c
+++ b/net/netfilter/xt_conntrack.c
@@ -1,212 +1,333 @@
-/* Kernel module to match connection tracking information.
- * Superset of Rusty's minimalistic state match.
+/*
+ *	xt_conntrack - Netfilter module to match connection tracking
+ *	information. (Superset of Rusty's minimalistic state match.)
  *
- * (C) 2001  Marc Boucher (marc@mbsi.ca).
+ *	(C) 2001  Marc Boucher (marc@mbsi.ca).
+ *	(C) 2006-2012 Patrick McHardy <kaber@trash.net>
+ *	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.
+ *	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.
  */
-
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 #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_DESCRIPTION("iptables connection tracking match module");
+MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
+MODULE_DESCRIPTION("Xtables: connection tracking state match");
 MODULE_ALIAS("ipt_conntrack");
+MODULE_ALIAS("ip6t_conntrack");
 
 static bool
-match(const struct sk_buff *skb,
-      const struct net_device *in,
-      const struct net_device *out,
-      const struct xt_match *match,
-      const void *matchinfo,
-      int offset,
-      unsigned int protoff,
-      bool *hotdrop)
-{
-	const struct xt_conntrack_info *sinfo = matchinfo;
-	const struct nf_conn *ct;
+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 inline bool
+port_match(u16 min, u16 max, u16 port, bool invert)
+{
+	return (port >= min && port <= max) ^ invert;
+}
+
+static inline bool
+ct_proto_port_check_v3(const struct xt_conntrack_mtinfo3 *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) &&
+	    !port_match(info->origsrc_port, info->origsrc_port_high,
+			ntohs(tuple->src.u.all),
+			info->invert_flags & XT_CONNTRACK_ORIGSRC_PORT))
+		return false;
+
+	if ((info->match_flags & XT_CONNTRACK_ORIGDST_PORT) &&
+	    !port_match(info->origdst_port, info->origdst_port_high,
+			ntohs(tuple->dst.u.all),
+			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) &&
+	    !port_match(info->replsrc_port, info->replsrc_port_high,
+			ntohs(tuple->src.u.all),
+			info->invert_flags & XT_CONNTRACK_REPLSRC_PORT))
+		return false;
+
+	if ((info->match_flags & XT_CONNTRACK_REPLDST_PORT) &&
+	    !port_match(info->repldst_port, info->repldst_port_high,
+			ntohs(tuple->dst.u.all),
+			info->invert_flags & XT_CONNTRACK_REPLDST_PORT))
+		return false;
+
+	return true;
+}
+
+static bool
+conntrack_mt(const struct sk_buff *skb, struct xt_action_param *par,
+             u16 state_mask, u16 status_mask)
+{
+	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);
 
-#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
+	if (ct) {
+		if (nf_ct_is_untracked(ct))
+			statebit = XT_CONNTRACK_STATE_UNTRACKED;
+		else
+			statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
+	} else
 		statebit = XT_CONNTRACK_STATE_INVALID;
 
-	if (sinfo->flags & XT_CONNTRACK_STATE) {
-		if (ct) {
+	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 (FWINV((statebit & sinfo->statemask) == 0,
-			  XT_CONNTRACK_STATE))
-			return false;
-	}
-
-	if (ct == NULL) {
-		if (sinfo->flags & ~XT_CONNTRACK_STATE)
+		if (!!(state_mask & statebit) ^
+		    !(info->invert_flags & XT_CONNTRACK_STATE))
 			return false;
-		return true;
 	}
 
-	if (sinfo->flags & XT_CONNTRACK_PROTO &&
-	    FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum !=
-		  sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum,
-		  XT_CONNTRACK_PROTO))
+	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 (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 (info->match_flags & XT_CONNTRACK_ORIGSRC)
+		if (conntrack_mt_origsrc(ct, info, par->family) ^
+		    !(info->invert_flags & 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 (info->match_flags & XT_CONNTRACK_ORIGDST)
+		if (conntrack_mt_origdst(ct, info, par->family) ^
+		    !(info->invert_flags & 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 (info->match_flags & XT_CONNTRACK_REPLSRC)
+		if (conntrack_mt_replsrc(ct, info, par->family) ^
+		    !(info->invert_flags & 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 (info->match_flags & XT_CONNTRACK_REPLDST)
+		if (conntrack_mt_repldst(ct, info, par->family) ^
+		    !(info->invert_flags & XT_CONNTRACK_REPLDST))
+			return false;
+
+	if (par->match->revision != 3) {
+		if (!ct_proto_port_check(info, ct))
+			return false;
+	} else {
+		if (!ct_proto_port_check_v3(par->matchinfo, ct))
+			return false;
+	}
 
-	if (sinfo->flags & XT_CONNTRACK_STATUS &&
-	    FWINV((ct->status & sinfo->statusmask) == 0,
-		  XT_CONNTRACK_STATUS))
+	if ((info->match_flags & XT_CONNTRACK_STATUS) &&
+	    (!!(status_mask & ct->status) ^
+	    !(info->invert_flags & 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 (info->match_flags & XT_CONNTRACK_EXPIRES) {
+		unsigned long expires = 0;
 
-		if (FWINV(!(expires >= sinfo->expires_min &&
-			    expires <= sinfo->expires_max),
-			  XT_CONNTRACK_EXPIRES))
+		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
-checkentry(const char *tablename,
-	   const void *ip,
-	   const struct xt_match *match,
-	   void *matchinfo,
-	   unsigned int hook_mask)
-{
-	if (nf_ct_l3proto_try_module_get(match->family) < 0) {
-		printk(KERN_WARNING "can't load conntrack support for "
-				    "proto=%d\n", match->family);
-		return false;
-	}
-	return true;
+conntrack_mt_v1(const struct sk_buff *skb, struct xt_action_param *par)
+{
+	const struct xt_conntrack_mtinfo1 *info = par->matchinfo;
+
+	return conntrack_mt(skb, par, info->state_mask, info->status_mask);
 }
 
-static void destroy(const struct xt_match *match, void *matchinfo)
+static bool
+conntrack_mt_v2(const struct sk_buff *skb, struct xt_action_param *par)
 {
-	nf_ct_l3proto_module_put(match->family);
+	const struct xt_conntrack_mtinfo2 *info = par->matchinfo;
+
+	return conntrack_mt(skb, par, info->state_mask, info->status_mask);
 }
 
-#ifdef CONFIG_COMPAT
-struct compat_xt_conntrack_info
+static bool
+conntrack_mt_v3(const struct sk_buff *skb, struct xt_action_param *par)
 {
-	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;
-};
+	const struct xt_conntrack_mtinfo3 *info = par->matchinfo;
+
+	return conntrack_mt(skb, par, info->state_mask, info->status_mask);
+}
+
+static int conntrack_mt_check(const struct xt_mtchk_param *par)
+{
+	int ret;
+
+	ret = nf_ct_l3proto_try_module_get(par->family);
+	if (ret < 0)
+		pr_info("cannot load conntrack support for proto=%u\n",
+			par->family);
+	return ret;
+}
+
+static void conntrack_mt_destroy(const struct xt_mtdtor_param *par)
+{
+	nf_ct_l3proto_module_put(par->family);
+}
 
-static void compat_from_user(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 compat_to_user(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_match __read_mostly = {
-	.name		= "conntrack",
-	.match		= match,
-	.checkentry	= checkentry,
-	.destroy	= destroy,
-	.matchsize	= sizeof(struct xt_conntrack_info),
-#ifdef CONFIG_COMPAT
-	.compatsize	= sizeof(struct compat_xt_conntrack_info),
-	.compat_from_user = compat_from_user,
-	.compat_to_user	= compat_to_user,
-#endif
-	.family		= AF_INET,
-	.me		= THIS_MODULE,
+static struct xt_match conntrack_mt_reg[] __read_mostly = {
+	{
+		.name       = "conntrack",
+		.revision   = 1,
+		.family     = NFPROTO_UNSPEC,
+		.matchsize  = sizeof(struct xt_conntrack_mtinfo1),
+		.match      = conntrack_mt_v1,
+		.checkentry = conntrack_mt_check,
+		.destroy    = conntrack_mt_destroy,
+		.me         = THIS_MODULE,
+	},
+	{
+		.name       = "conntrack",
+		.revision   = 2,
+		.family     = NFPROTO_UNSPEC,
+		.matchsize  = sizeof(struct xt_conntrack_mtinfo2),
+		.match      = conntrack_mt_v2,
+		.checkentry = conntrack_mt_check,
+		.destroy    = conntrack_mt_destroy,
+		.me         = THIS_MODULE,
+	},
+	{
+		.name       = "conntrack",
+		.revision   = 3,
+		.family     = NFPROTO_UNSPEC,
+		.matchsize  = sizeof(struct xt_conntrack_mtinfo3),
+		.match      = conntrack_mt_v3,
+		.checkentry = conntrack_mt_check,
+		.destroy    = conntrack_mt_destroy,
+		.me         = THIS_MODULE,
+	},
 };
 
-static int __init xt_conntrack_init(void)
+static int __init conntrack_mt_init(void)
 {
-	return xt_register_match(&conntrack_match);
+	return xt_register_matches(conntrack_mt_reg,
+	       ARRAY_SIZE(conntrack_mt_reg));
 }
 
-static void __exit xt_conntrack_fini(void)
+static void __exit conntrack_mt_exit(void)
 {
-	xt_unregister_match(&conntrack_match);
+	xt_unregister_matches(conntrack_mt_reg, ARRAY_SIZE(conntrack_mt_reg));
 }
 
-module_init(xt_conntrack_init);
-module_exit(xt_conntrack_fini);
+module_init(conntrack_mt_init);
+module_exit(conntrack_mt_exit);