Index: linux-2.4.35.4/Documentation/Configure.help
===================================================================
--- linux-2.4.35.4.orig/Documentation/Configure.help
+++ linux-2.4.35.4/Documentation/Configure.help
@@ -3209,6 +3209,15 @@ CONFIG_IP_NF_TARGET_LOG
   If you want to compile it as a module, say M here and read
   <file:Documentation/modules.txt>.  If unsure, say `N'.
 
+TTL target support
+CONFIG_IP_NF_TARGET_TTL
+  This option adds a `TTL' target, which enables the user to set
+  the TTL value or increment / decrement the TTL value by a given
+  amount.
+
+  If you want to compile it as a module, say M here and read
+  Documentation/modules.txt.  If unsure, say `N'.
+
 ipchains (2.2-style) support
 CONFIG_IP_NF_COMPAT_IPCHAINS
   This option places ipchains (with masquerading and redirection
Index: linux-2.4.35.4/include/linux/netfilter_ipv4/ipt_TTL.h
===================================================================
--- /dev/null
+++ linux-2.4.35.4/include/linux/netfilter_ipv4/ipt_TTL.h
@@ -0,0 +1,21 @@
+/* TTL modification module for IP tables
+ * (C) 2000 by Harald Welte <laforge@gnumonks.org> */
+
+#ifndef _IPT_TTL_H
+#define _IPT_TTL_H
+
+enum {
+	IPT_TTL_SET = 0,
+	IPT_TTL_INC,
+	IPT_TTL_DEC
+};
+
+#define IPT_TTL_MAXMODE	IPT_TTL_DEC
+
+struct ipt_TTL_info {
+	u_int8_t	mode;
+	u_int8_t	ttl;
+};
+
+
+#endif
Index: linux-2.4.35.4/net/ipv4/netfilter/Config.in
===================================================================
--- linux-2.4.35.4.orig/net/ipv4/netfilter/Config.in
+++ linux-2.4.35.4/net/ipv4/netfilter/Config.in
@@ -125,6 +125,7 @@ if [ "$CONFIG_IP_NF_IPTABLES" != "n" ]; 
     dep_tristate '    MARK target support' CONFIG_IP_NF_TARGET_MARK $CONFIG_IP_NF_MANGLE
   fi
   dep_tristate '  LOG target support' CONFIG_IP_NF_TARGET_LOG $CONFIG_IP_NF_IPTABLES
+  dep_tristate '  TTL target support' CONFIG_IP_NF_TARGET_TTL $CONFIG_IP_NF_IPTABLES
   dep_tristate '  ULOG target support' CONFIG_IP_NF_TARGET_ULOG $CONFIG_IP_NF_IPTABLES
   dep_tristate '  TCPMSS target support' CONFIG_IP_NF_TARGET_TCPMSS $CONFIG_IP_NF_IPTABLES
 fi
Index: linux-2.4.35.4/net/ipv4/netfilter/ipt_TTL.c
===================================================================
--- /dev/null
+++ linux-2.4.35.4/net/ipv4/netfilter/ipt_TTL.c
@@ -0,0 +1,110 @@
+/* TTL modification target for IP tables
+ * (C) 2000 by Harald Welte <laforge@gnumonks.org>
+ *
+ * Version: $Revision: 1.1 $
+ *
+ * This software is distributed under the terms of GNU GPL
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <net/checksum.h>
+
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_TTL.h>
+
+MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
+MODULE_DESCRIPTION("IP tables TTL modification module");
+MODULE_LICENSE("GPL");
+
+static unsigned int ipt_ttl_target(struct sk_buff **pskb, unsigned int hooknum,
+		const struct net_device *in, const struct net_device *out,
+		const void *targinfo, void *userinfo)
+{
+	struct iphdr *iph = (*pskb)->nh.iph;
+	const struct ipt_TTL_info *info = targinfo;
+	u_int16_t diffs[2];
+	int new_ttl;
+			 
+	switch (info->mode) {
+		case IPT_TTL_SET:
+			new_ttl = info->ttl;
+			break;
+		case IPT_TTL_INC:
+			new_ttl = iph->ttl + info->ttl;
+			if (new_ttl > 255)
+				new_ttl = 255;
+			break;
+		case IPT_TTL_DEC:
+			new_ttl = iph->ttl - info->ttl;
+			if (new_ttl < 0)
+				new_ttl = 0;
+			break;
+		default:
+			new_ttl = iph->ttl;
+			break;
+	}
+
+	if (new_ttl != iph->ttl) {
+		diffs[0] = htons(((unsigned)iph->ttl) << 8) ^ 0xFFFF;
+		iph->ttl = new_ttl;
+		diffs[1] = htons(((unsigned)iph->ttl) << 8);
+		iph->check = csum_fold(csum_partial((char *)diffs,
+						    sizeof(diffs),
+				 	            iph->check^0xFFFF));
+									                	(*pskb)->nfcache |= NFC_ALTERED;
+	}
+
+	return IPT_CONTINUE;
+}
+
+static int ipt_ttl_checkentry(const char *tablename,
+		const struct ipt_entry *e,
+		void *targinfo,
+		unsigned int targinfosize,
+		unsigned int hook_mask)
+{
+	struct ipt_TTL_info *info = targinfo;
+
+	if (targinfosize != IPT_ALIGN(sizeof(struct ipt_TTL_info))) {
+		printk(KERN_WARNING "TTL: targinfosize %u != %Zu\n",
+				targinfosize,
+				IPT_ALIGN(sizeof(struct ipt_TTL_info)));
+		return 0;	
+	}	
+
+	if (strcmp(tablename, "mangle")) {
+		printk(KERN_WARNING "TTL: can only be called from \"mangle\" table, not \"%s\"\n", tablename);
+		return 0;
+	}
+
+	if (info->mode > IPT_TTL_MAXMODE) {
+		printk(KERN_WARNING "TTL: invalid or unknown Mode %u\n", 
+			info->mode);
+		return 0;
+	}
+
+	if ((info->mode != IPT_TTL_SET) && (info->ttl == 0)) {
+		printk(KERN_WARNING "TTL: increment/decrement doesn't make sense with value 0\n");
+		return 0;
+	}
+	
+	return 1;
+}
+
+static struct ipt_target ipt_TTL = { { NULL, NULL }, "TTL", 
+	ipt_ttl_target, ipt_ttl_checkentry, NULL, THIS_MODULE };
+
+static int __init init(void)
+{
+	return ipt_register_target(&ipt_TTL);
+}
+
+static void __exit fini(void)
+{
+	ipt_unregister_target(&ipt_TTL);
+}
+
+module_init(init);
+module_exit(fini);
Index: linux-2.4.35.4/net/ipv4/netfilter/Makefile
===================================================================
--- linux-2.4.35.4.orig/net/ipv4/netfilter/Makefile
+++ linux-2.4.35.4/net/ipv4/netfilter/Makefile
@@ -109,6 +109,7 @@ obj-$(CONFIG_IP_NF_TARGET_MASQUERADE) +=
 obj-$(CONFIG_IP_NF_TARGET_REDIRECT) += ipt_REDIRECT.o
 obj-$(CONFIG_IP_NF_NAT_SNMP_BASIC) += ip_nat_snmp_basic.o
 obj-$(CONFIG_IP_NF_TARGET_LOG) += ipt_LOG.o
+obj-$(CONFIG_IP_NF_TARGET_TTL) += ipt_TTL.o
 obj-$(CONFIG_IP_NF_TARGET_ULOG) += ipt_ULOG.o
 obj-$(CONFIG_IP_NF_TARGET_TCPMSS) += ipt_TCPMSS.o
 
