diff -urN linux-2.4.30.old/Documentation/Configure.help linux-2.4.30.dev/Documentation/Configure.help --- linux-2.4.30.old/Documentation/Configure.help 2005-04-27 11:35:46.000000000 +0200 +++ linux-2.4.30.dev/Documentation/Configure.help 2005-04-27 11:43:49.000000000 +0200 @@ -3209,6 +3209,15 @@ If you want to compile it as a module, say M here and read . 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 diff -urN linux-2.4.30.old/include/linux/netfilter_ipv4/ipt_TTL.h linux-2.4.30.dev/include/linux/netfilter_ipv4/ipt_TTL.h --- linux-2.4.30.old/include/linux/netfilter_ipv4/ipt_TTL.h 1970-01-01 01:00:00.000000000 +0100 +++ linux-2.4.30.dev/include/linux/netfilter_ipv4/ipt_TTL.h 2005-04-27 11:43:49.000000000 +0200 @@ -0,0 +1,21 @@ +/* TTL modification module for IP tables + * (C) 2000 by Harald Welte */ + +#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 diff -urN linux-2.4.30.old/net/ipv4/netfilter/Config.in linux-2.4.30.dev/net/ipv4/netfilter/Config.in --- linux-2.4.30.old/net/ipv4/netfilter/Config.in 2005-04-27 11:35:45.000000000 +0200 +++ linux-2.4.30.dev/net/ipv4/netfilter/Config.in 2005-04-27 11:43:49.000000000 +0200 @@ -129,6 +129,7 @@ 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 diff -urN linux-2.4.30.old/net/ipv4/netfilter/ipt_TTL.c linux-2.4.30.dev/net/ipv4/netfilter/ipt_TTL.c --- linux-2.4.30.old/net/ipv4/netfilter/ipt_TTL.c 1970-01-01 01:00:00.000000000 +0100 +++ linux-2.4.30.dev/net/ipv4/netfilter/ipt_TTL.c 2005-04-27 11:43:49.000000000 +0200 @@ -0,0 +1,110 @@ +/* TTL modification target for IP tables + * (C) 2000 by Harald Welte + * + * Version: $Revision: 1.1 $ + * + * This software is distributed under the terms of GNU GPL + */ + +#include +#include +#include +#include + +#include +#include + +MODULE_AUTHOR("Harald Welte "); +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); diff -urN linux-2.4.30.old/net/ipv4/netfilter/Makefile linux-2.4.30.dev/net/ipv4/netfilter/Makefile --- linux-2.4.30.old/net/ipv4/netfilter/Makefile 2005-04-27 11:35:45.000000000 +0200 +++ linux-2.4.30.dev/net/ipv4/netfilter/Makefile 2005-04-27 11:43:49.000000000 +0200 @@ -112,6 +112,7 @@ 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