[NETFILTER]: xt_conntrack match, revision 1
Introduces the xt_conntrack match revision 1. It uses fixed types, the
new nf_inet_addr and comes with IPv6 support, thereby completely
superseding xt_state.
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/xt_conntrack.c b/net/netfilter/xt_conntrack.c
index 3f8bfba..dc9e737 100644
--- a/net/netfilter/xt_conntrack.c
+++ b/net/netfilter/xt_conntrack.c
@@ -1,15 +1,19 @@
-/* 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).
+ * Copyright © CC Computer Consultants GmbH, 2007 - 2008
+ * Jan Engelhardt <jengelh@computergmbh.de>
*
- * 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.
*/
#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>
@@ -18,12 +22,13 @@
MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
MODULE_DESCRIPTION("iptables connection tracking match module");
MODULE_ALIAS("ipt_conntrack");
+MODULE_ALIAS("ip6t_conntrack");
static bool
-conntrack_mt(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)
+conntrack_mt_v0(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;
@@ -112,6 +117,134 @@
}
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 == AF_INET)
+ return (kaddr->ip & umask->ip) == uaddr->ip;
+ else if (l3proto == AF_INET6)
+ 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_mtinfo1 *info,
+ unsigned int 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_mtinfo1 *info,
+ unsigned int 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_mtinfo1 *info,
+ unsigned int 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_mtinfo1 *info,
+ unsigned int family)
+{
+ return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3,
+ &info->repldst_addr, &info->repldst_mask, family);
+}
+
+static bool
+conntrack_mt(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_mtinfo1 *info = 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_PROTO) &&
+ ((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum ==
+ info->l4proto) ^ !(info->invert_flags & XT_CONNTRACK_PROTO)))
+ return false;
+
+ if (info->match_flags & XT_CONNTRACK_ORIGSRC)
+ if (conntrack_mt_origsrc(ct, info, match->family) ^
+ !(info->invert_flags & XT_CONNTRACK_ORIGSRC))
+ return false;
+
+ if (info->match_flags & XT_CONNTRACK_ORIGDST)
+ if (conntrack_mt_origdst(ct, info, match->family) ^
+ !(info->invert_flags & XT_CONNTRACK_ORIGDST))
+ return false;
+
+ if (info->match_flags & XT_CONNTRACK_REPLSRC)
+ if (conntrack_mt_replsrc(ct, info, match->family) ^
+ !(info->invert_flags & XT_CONNTRACK_REPLSRC))
+ return false;
+
+ if (info->match_flags & XT_CONNTRACK_REPLDST)
+ if (conntrack_mt_repldst(ct, info, match->family) ^
+ !(info->invert_flags & XT_CONNTRACK_REPLDST))
+ 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_check(const char *tablename, const void *ip,
const struct xt_match *match, void *matchinfo,
unsigned int hook_mask)
@@ -144,7 +277,7 @@
u_int8_t invflags;
};
-static void conntrack_mt_compat_from_user(void *dst, void *src)
+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 = {
@@ -161,7 +294,7 @@
memcpy(dst, &m, sizeof(m));
}
-static int conntrack_mt_compat_to_user(void __user *dst, void *src)
+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 = {
@@ -179,29 +312,53 @@
}
#endif
-static struct xt_match conntrack_mt_reg __read_mostly = {
- .name = "conntrack",
- .match = conntrack_mt,
- .checkentry = conntrack_mt_check,
- .destroy = conntrack_mt_destroy,
- .matchsize = sizeof(struct xt_conntrack_info),
+static struct xt_match conntrack_mt_reg[] __read_mostly = {
+ {
+ .name = "conntrack",
+ .revision = 0,
+ .family = AF_INET,
+ .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,
- .compat_to_user = conntrack_mt_compat_to_user,
+ .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
- .family = AF_INET,
- .me = THIS_MODULE,
+ },
+ {
+ .name = "conntrack",
+ .revision = 1,
+ .family = AF_INET,
+ .matchsize = sizeof(struct xt_conntrack_mtinfo1),
+ .match = conntrack_mt,
+ .checkentry = conntrack_mt_check,
+ .destroy = conntrack_mt_destroy,
+ .me = THIS_MODULE,
+ },
+ {
+ .name = "conntrack",
+ .revision = 1,
+ .family = AF_INET6,
+ .matchsize = sizeof(struct xt_conntrack_mtinfo1),
+ .match = conntrack_mt,
+ .checkentry = conntrack_mt_check,
+ .destroy = conntrack_mt_destroy,
+ .me = THIS_MODULE,
+ },
};
static int __init conntrack_mt_init(void)
{
- return xt_register_match(&conntrack_mt_reg);
+ return xt_register_matches(conntrack_mt_reg,
+ ARRAY_SIZE(conntrack_mt_reg));
}
static void __exit conntrack_mt_exit(void)
{
- xt_unregister_match(&conntrack_mt_reg);
+ xt_unregister_matches(conntrack_mt_reg, ARRAY_SIZE(conntrack_mt_reg));
}
module_init(conntrack_mt_init);