package/linux/kernel-patches/312-netfilter-TTL

   1 diff -urN linux-2.4.30.old/Documentation/Configure.help linux-2.4.30.dev/Documentation/Configure.help
   2 --- linux-2.4.30.old/Documentation/Configure.help       2005-04-27 11:35:46.000000000 +0200
   3 +++ linux-2.4.30.dev/Documentation/Configure.help       2005-04-27 11:43:49.000000000 +0200
   4 @@ -3209,6 +3209,15 @@
   5    If you want to compile it as a module, say M here and read
   6    <file:Documentation/modules.txt>.  If unsure, say `N'.
   7
   8 +TTL target support
   9 +CONFIG_IP_NF_TARGET_TTL
  10 +  This option adds a `TTL' target, which enables the user to set
  11 +  the TTL value or increment / decrement the TTL value by a given
  12 +  amount.
  13 +
  14 +  If you want to compile it as a module, say M here and read
  15 +  Documentation/modules.txt.  If unsure, say `N'.
  16 +
  17  ipchains (2.2-style) support
  18  CONFIG_IP_NF_COMPAT_IPCHAINS
  19    This option places ipchains (with masquerading and redirection
  20 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
  21 --- linux-2.4.30.old/include/linux/netfilter_ipv4/ipt_TTL.h     1970-01-01 01:00:00.000000000 +0100
  22 +++ linux-2.4.30.dev/include/linux/netfilter_ipv4/ipt_TTL.h     2005-04-27 11:43:49.000000000 +0200
  23 @@ -0,0 +1,21 @@
  24 +/* TTL modification module for IP tables
  25 + * (C) 2000 by Harald Welte <laforge@gnumonks.org> */
  26 +
  27 +#ifndef _IPT_TTL_H
  28 +#define _IPT_TTL_H
  29 +
  30 +enum {
  31 +       IPT_TTL_SET = 0,
  32 +       IPT_TTL_INC,
  33 +       IPT_TTL_DEC
  34 +};
  35 +
  36 +#define IPT_TTL_MAXMODE        IPT_TTL_DEC
  37 +
  38 +struct ipt_TTL_info {
  39 +       u_int8_t        mode;
  40 +       u_int8_t        ttl;
  41 +};
  42 +
  43 +
  44 +#endif
  45 diff -urN linux-2.4.30.old/net/ipv4/netfilter/Config.in linux-2.4.30.dev/net/ipv4/netfilter/Config.in
  46 --- linux-2.4.30.old/net/ipv4/netfilter/Config.in       2005-04-27 11:35:45.000000000 +0200
  47 +++ linux-2.4.30.dev/net/ipv4/netfilter/Config.in       2005-04-27 11:43:49.000000000 +0200
  48 @@ -129,6 +129,7 @@
  49      dep_tristate '    MARK target support' CONFIG_IP_NF_TARGET_MARK $CONFIG_IP_NF_MANGLE
  50    fi
  51    dep_tristate '  LOG target support' CONFIG_IP_NF_TARGET_LOG $CONFIG_IP_NF_IPTABLES
  52 +  dep_tristate '  TTL target support' CONFIG_IP_NF_TARGET_TTL $CONFIG_IP_NF_IPTABLES
  53    dep_tristate '  ULOG target support' CONFIG_IP_NF_TARGET_ULOG $CONFIG_IP_NF_IPTABLES
  54    dep_tristate '  TCPMSS target support' CONFIG_IP_NF_TARGET_TCPMSS $CONFIG_IP_NF_IPTABLES
  55  fi
  56 diff -urN linux-2.4.30.old/net/ipv4/netfilter/ipt_TTL.c linux-2.4.30.dev/net/ipv4/netfilter/ipt_TTL.c
  57 --- linux-2.4.30.old/net/ipv4/netfilter/ipt_TTL.c       1970-01-01 01:00:00.000000000 +0100
  58 +++ linux-2.4.30.dev/net/ipv4/netfilter/ipt_TTL.c       2005-04-27 11:43:49.000000000 +0200
  59 @@ -0,0 +1,110 @@
  60 +/* TTL modification target for IP tables
  61 + * (C) 2000 by Harald Welte <laforge@gnumonks.org>
  62 + *
  63 + * Version: $Revision$
  64 + *
  65 + * This software is distributed under the terms of GNU GPL
  66 + */
  67 +
  68 +#include <linux/module.h>
  69 +#include <linux/skbuff.h>
  70 +#include <linux/ip.h>
  71 +#include <net/checksum.h>
  72 +
  73 +#include <linux/netfilter_ipv4/ip_tables.h>
  74 +#include <linux/netfilter_ipv4/ipt_TTL.h>
  75 +
  76 +MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
  77 +MODULE_DESCRIPTION("IP tables TTL modification module");
  78 +MODULE_LICENSE("GPL");
  79 +
  80 +static unsigned int ipt_ttl_target(struct sk_buff **pskb, unsigned int hooknum,
  81 +               const struct net_device *in, const struct net_device *out,
  82 +               const void *targinfo, void *userinfo)
  83 +{
  84 +       struct iphdr *iph = (*pskb)->nh.iph;
  85 +       const struct ipt_TTL_info *info = targinfo;
  86 +       u_int16_t diffs[2];
  87 +       int new_ttl;
  88 +
  89 +       switch (info->mode) {
  90 +               case IPT_TTL_SET:
  91 +                       new_ttl = info->ttl;
  92 +                       break;
  93 +               case IPT_TTL_INC:
  94 +                       new_ttl = iph->ttl + info->ttl;
  95 +                       if (new_ttl > 255)
  96 +                               new_ttl = 255;
  97 +                       break;
  98 +               case IPT_TTL_DEC:
  99 +                       new_ttl = iph->ttl - info->ttl;
 100 +                       if (new_ttl < 0)
 101 +                               new_ttl = 0;
 102 +                       break;
 103 +               default:
 104 +                       new_ttl = iph->ttl;
 105 +                       break;
 106 +       }
 107 +
 108 +       if (new_ttl != iph->ttl) {
 109 +               diffs[0] = htons(((unsigned)iph->ttl) << 8) ^ 0xFFFF;
 110 +               iph->ttl = new_ttl;
 111 +               diffs[1] = htons(((unsigned)iph->ttl) << 8);
 112 +               iph->check = csum_fold(csum_partial((char *)diffs,
 113 +                                                   sizeof(diffs),
 114 +                                                   iph->check^0xFFFF));
 115 +                                                                                               (*pskb)->nfcache |= NFC_ALTERED;
 116 +       }
 117 +
 118 +       return IPT_CONTINUE;
 119 +}
 120 +
 121 +static int ipt_ttl_checkentry(const char *tablename,
 122 +               const struct ipt_entry *e,
 123 +               void *targinfo,
 124 +               unsigned int targinfosize,
 125 +               unsigned int hook_mask)
 126 +{
 127 +       struct ipt_TTL_info *info = targinfo;
 128 +
 129 +       if (targinfosize != IPT_ALIGN(sizeof(struct ipt_TTL_info))) {
 130 +               printk(KERN_WARNING "TTL: targinfosize %u != %Zu\n",
 131 +                               targinfosize,
 132 +                               IPT_ALIGN(sizeof(struct ipt_TTL_info)));
 133 +               return 0;
 134 +       }
 135 +
 136 +       if (strcmp(tablename, "mangle")) {
 137 +               printk(KERN_WARNING "TTL: can only be called from \"mangle\" table, not \"%s\"\n", tablename);
 138 +               return 0;
 139 +       }
 140 +
 141 +       if (info->mode > IPT_TTL_MAXMODE) {
 142 +               printk(KERN_WARNING "TTL: invalid or unknown Mode %u\n",
 143 +                       info->mode);
 144 +               return 0;
 145 +       }
 146 +
 147 +       if ((info->mode != IPT_TTL_SET) && (info->ttl == 0)) {
 148 +               printk(KERN_WARNING "TTL: increment/decrement doesn't make sense with value 0\n");
 149 +               return 0;
 150 +       }
 151 +
 152 +       return 1;
 153 +}
 154 +
 155 +static struct ipt_target ipt_TTL = { { NULL, NULL }, "TTL",
 156 +       ipt_ttl_target, ipt_ttl_checkentry, NULL, THIS_MODULE };
 157 +
 158 +static int __init init(void)
 159 +{
 160 +       return ipt_register_target(&ipt_TTL);
 161 +}
 162 +
 163 +static void __exit fini(void)
 164 +{
 165 +       ipt_unregister_target(&ipt_TTL);
 166 +}
 167 +
 168 +module_init(init);
 169 +module_exit(fini);
 170 diff -urN linux-2.4.30.old/net/ipv4/netfilter/Makefile linux-2.4.30.dev/net/ipv4/netfilter/Makefile
 171 --- linux-2.4.30.old/net/ipv4/netfilter/Makefile        2005-04-27 11:35:45.000000000 +0200
 172 +++ linux-2.4.30.dev/net/ipv4/netfilter/Makefile        2005-04-27 11:43:49.000000000 +0200
 173 @@ -112,6 +112,7 @@
 174  obj-$(CONFIG_IP_NF_TARGET_REDIRECT) += ipt_REDIRECT.o
 175  obj-$(CONFIG_IP_NF_NAT_SNMP_BASIC) += ip_nat_snmp_basic.o
 176  obj-$(CONFIG_IP_NF_TARGET_LOG) += ipt_LOG.o
 177 +obj-$(CONFIG_IP_NF_TARGET_TTL) += ipt_TTL.o
 178  obj-$(CONFIG_IP_NF_TARGET_ULOG) += ipt_ULOG.o
 179  obj-$(CONFIG_IP_NF_TARGET_TCPMSS) += ipt_TCPMSS.o
 180