[NETFILTER]: xt_connmark match, revision 1

Introduces the xt_connmark match revision 1. It uses fixed types,
eventually obsoleting revision 0 some day (uses nonfixed types).
(Unfixed types like "unsigned long" do not play well with mixed
user-/kernelspace "bitness", e.g. 32/64, as is common on SPARC64,
and need extra compat code.)
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>

include/linux/netfilter/xt_connmark.h

@@ -15,4 +15,9 @@ struct xt_connmark_info {
 	u_int8_t invert;
 };
 
+struct xt_connmark_mtinfo1 {
+	u_int32_t mark, mask;
+	u_int8_t invert;
+};
+
 #endif /*_XT_CONNMARK_H*/

net/netfilter/xt_connmark.c

-/* This kernel module matches connection mark values set by the
- * CONNMARK target
+/*
+ *	xt_connmark - Netfilter module to match connection mark values
  *
- * Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
- * by Henrik Nordstrom <hno@marasystems.com>
+ *	Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
+ *	by Henrik Nordstrom <hno@marasystems.com>
+ *	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 as published by
@@ -36,6 +38,23 @@ connmark_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_connmark_mtinfo1 *info = matchinfo;
+	enum ip_conntrack_info ctinfo;
+	const struct nf_conn *ct;
+
+	ct = nf_ct_get(skb, &ctinfo);
+	if (ct == NULL)
+		return false;
+
+	return ((ct->mark & info->mask) == info->mark) ^ info->invert;
+}
+
+static bool
+connmark_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_connmark_info *info = matchinfo;
 	const struct nf_conn *ct;
@@ -49,9 +68,9 @@ connmark_mt(const struct sk_buff *skb, const struct net_device *in,
 }
 
 static bool
-connmark_mt_check(const char *tablename, const void *ip,
-                  const struct xt_match *match, void *matchinfo,
-                  unsigned int hook_mask)
+connmark_mt_check_v0(const char *tablename, const void *ip,
+                     const struct xt_match *match, void *matchinfo,
+                     unsigned int hook_mask)
 {
 	const struct xt_connmark_info *cm = matchinfo;
 
@@ -67,6 +86,19 @@ connmark_mt_check(const char *tablename, const void *ip,
 	return true;
 }
 
+static bool
+connmark_mt_check(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 "cannot load conntrack support for "
+		       "proto=%u\n", match->family);
+		return false;
+	}
+	return true;
+}
+
 static void
 connmark_mt_destroy(const struct xt_match *match, void *matchinfo)
 {
@@ -81,7 +113,7 @@ struct compat_xt_connmark_info {
 	u_int16_t	__pad2;
 };
 
-static void connmark_mt_compat_from_user(void *dst, void *src)
+static void connmark_mt_compat_from_user_v0(void *dst, void *src)
 {
 	const struct compat_xt_connmark_info *cm = src;
 	struct xt_connmark_info m = {
@@ -92,7 +124,7 @@ static void connmark_mt_compat_from_user(void *dst, void *src)
 	memcpy(dst, &m, sizeof(m));
 }
 
-static int connmark_mt_compat_to_user(void __user *dst, void *src)
+static int connmark_mt_compat_to_user_v0(void __user *dst, void *src)
 {
 	const struct xt_connmark_info *m = src;
 	struct compat_xt_connmark_info cm = {
@@ -107,32 +139,54 @@ static int connmark_mt_compat_to_user(void __user *dst, void *src)
 static struct xt_match connmark_mt_reg[] __read_mostly = {
 	{
 		.name		= "connmark",
+		.revision	= 0,
 		.family		= AF_INET,
-		.checkentry	= connmark_mt_check,
-		.match		= connmark_mt,
+		.checkentry	= connmark_mt_check_v0,
+		.match		= connmark_mt_v0,
 		.destroy	= connmark_mt_destroy,
 		.matchsize	= sizeof(struct xt_connmark_info),
 #ifdef CONFIG_COMPAT
 		.compatsize	= sizeof(struct compat_xt_connmark_info),
-		.compat_from_user = connmark_mt_compat_from_user,
-		.compat_to_user	= connmark_mt_compat_to_user,
+		.compat_from_user = connmark_mt_compat_from_user_v0,
+		.compat_to_user	= connmark_mt_compat_to_user_v0,
 #endif
 		.me		= THIS_MODULE
 	},
 	{
 		.name		= "connmark",
+		.revision	= 0,
 		.family		= AF_INET6,
-		.checkentry	= connmark_mt_check,
-		.match		= connmark_mt,
+		.checkentry	= connmark_mt_check_v0,
+		.match		= connmark_mt_v0,
 		.destroy	= connmark_mt_destroy,
 		.matchsize	= sizeof(struct xt_connmark_info),
 #ifdef CONFIG_COMPAT
 		.compatsize	= sizeof(struct compat_xt_connmark_info),
-		.compat_from_user = connmark_mt_compat_from_user,
-		.compat_to_user	= connmark_mt_compat_to_user,
+		.compat_from_user = connmark_mt_compat_from_user_v0,
+		.compat_to_user	= connmark_mt_compat_to_user_v0,
 #endif
 		.me		= THIS_MODULE
 	},
+	{
+		.name           = "connmark",
+		.revision       = 1,
+		.family         = AF_INET,
+		.checkentry     = connmark_mt_check,
+		.match          = connmark_mt,
+		.matchsize      = sizeof(struct xt_connmark_mtinfo1),
+		.destroy        = connmark_mt_destroy,
+		.me             = THIS_MODULE,
+	},
+	{
+		.name           = "connmark",
+		.revision       = 1,
+		.family         = AF_INET6,
+		.checkentry     = connmark_mt_check,
+		.match          = connmark_mt,
+		.matchsize      = sizeof(struct xt_connmark_mtinfo1),
+		.destroy        = connmark_mt_destroy,
+		.me             = THIS_MODULE,
+	},
 };
 
 static int __init connmark_mt_init(void)