[NETFILTER]: xt_MARK target, revision 2

Introduces the xt_MARK target revision 2. It uses fixed types, and
also uses the more expressive XOR logic.

Signed-off-by: Jan Engelhardt <[e-mail]>
Signed-off-by: Patrick McHardy <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/linux/netfilter/xt_MARK.h

···
 	u_int8_t mode;
 };
 
+struct xt_mark_tginfo2 {
+	u_int32_t mark, mask;
+};
+
 #endif /*_XT_MARK_H_target */

net/netfilter/xt_MARK.c

···
-/* This is a module which is used for setting the NFMARK field of an skb. */
-
-/* (C) 1999-2001 Marc Boucher <[e-mail]>
+/*
+ *	xt_MARK - Netfilter module to modify the NFMARK field of an skb
  *
- * 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.
+ *	(C) 1999-2001 Marc Boucher <[e-mail]>
+ *	Copyright © CC Computer Consultants GmbH, 2007 - 2008
+ *	Jan Engelhardt <[e-mail]>
+ *
+ *	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>
···
 }
 
 static unsigned int
-mark_tg(struct sk_buff *skb, const struct net_device *in,
-        const struct net_device *out, unsigned int hooknum,
-        const struct xt_target *target, const void *targinfo)
+mark_tg_v1(struct sk_buff *skb, const struct net_device *in,
+           const struct net_device *out, unsigned int hooknum,
+           const struct xt_target *target, const void *targinfo)
 {
 	const struct xt_mark_target_info_v1 *markinfo = targinfo;
 	int mark = 0;
···
 	return XT_CONTINUE;
 }
 
+static unsigned int
+mark_tg(struct sk_buff *skb, const struct net_device *in,
+        const struct net_device *out, unsigned int hooknum,
+        const struct xt_target *target, const void *targinfo)
+{
+	const struct xt_mark_tginfo2 *info = targinfo;
+
+	skb->mark = (skb->mark & ~info->mask) ^ info->mark;
+	return XT_CONTINUE;
+}
+
 static bool
 mark_tg_check_v0(const char *tablename, const void *entry,
                  const struct xt_target *target, void *targinfo,
···
 }
 
 static bool
-mark_tg_check(const char *tablename, const void *entry,
-              const struct xt_target *target, void *targinfo,
-              unsigned int hook_mask)
+mark_tg_check_v1(const char *tablename, const void *entry,
+                 const struct xt_target *target, void *targinfo,
+                 unsigned int hook_mask)
 {
 	const struct xt_mark_target_info_v1 *markinfo = targinfo;
 
···
 	compat_ulong_t	mark;
 };
 
-static void mark_tg_compat_from_user(void *dst, void *src)
+static void mark_tg_compat_from_user_v0(void *dst, void *src)
 {
 	const struct compat_xt_mark_target_info *cm = src;
 	struct xt_mark_target_info m = {
···
 	memcpy(dst, &m, sizeof(m));
 }
 
-static int mark_tg_compat_to_user(void __user *dst, void *src)
+static int mark_tg_compat_to_user_v0(void __user *dst, void *src)
 {
 	const struct xt_mark_target_info *m = src;
 	struct compat_xt_mark_target_info cm = {
···
 		.targetsize	= sizeof(struct xt_mark_target_info),
 #ifdef CONFIG_COMPAT
 		.compatsize	= sizeof(struct compat_xt_mark_target_info),
-		.compat_from_user = mark_tg_compat_from_user,
-		.compat_to_user	= mark_tg_compat_to_user,
+		.compat_from_user = mark_tg_compat_from_user_v0,
+		.compat_to_user	= mark_tg_compat_to_user_v0,
 #endif
 		.table		= "mangle",
 		.me		= THIS_MODULE,
···
 		.name		= "MARK",
 		.family		= AF_INET,
 		.revision	= 1,
-		.checkentry	= mark_tg_check,
-		.target		= mark_tg,
+		.checkentry	= mark_tg_check_v1,
+		.target		= mark_tg_v1,
 		.targetsize	= sizeof(struct xt_mark_target_info_v1),
 #ifdef CONFIG_COMPAT
 		.compatsize	= sizeof(struct compat_xt_mark_target_info_v1),
···
 		.targetsize	= sizeof(struct xt_mark_target_info),
 #ifdef CONFIG_COMPAT
 		.compatsize	= sizeof(struct compat_xt_mark_target_info),
-		.compat_from_user = mark_tg_compat_from_user,
-		.compat_to_user	= mark_tg_compat_to_user,
+		.compat_from_user = mark_tg_compat_from_user_v0,
+		.compat_to_user	= mark_tg_compat_to_user_v0,
 #endif
 		.table		= "mangle",
 		.me		= THIS_MODULE,
···
 		.name		= "MARK",
 		.family		= AF_INET6,
 		.revision	= 1,
-		.checkentry	= mark_tg_check,
-		.target		= mark_tg,
+		.checkentry	= mark_tg_check_v1,
+		.target		= mark_tg_v1,
 		.targetsize	= sizeof(struct xt_mark_target_info_v1),
 #ifdef CONFIG_COMPAT
 		.compatsize	= sizeof(struct compat_xt_mark_target_info_v1),
···
 #endif
 		.table		= "mangle",
 		.me		= THIS_MODULE,
+	},
+	{
+		.name           = "MARK",
+		.revision       = 2,
+		.family         = AF_INET,
+		.target         = mark_tg,
+		.targetsize     = sizeof(struct xt_mark_tginfo2),
+		.me             = THIS_MODULE,
+	},
+	{
+		.name           = "MARK",
+		.revision       = 2,
+		.family         = AF_INET6,
+		.target         = mark_tg,
+		.targetsize     = sizeof(struct xt_mark_tginfo2),
+		.me             = THIS_MODULE,
 	},
 };