target/linux/generic-2.4/patches/606-netfilter_NETMAP.patch

   1 --- a/Documentation/Configure.help
   2 +++ b/Documentation/Configure.help
   3 @@ -3086,6 +3086,17 @@ CONFIG_IP_NF_TARGET_REDIRECT
   4    If you want to compile it as a module, say M here and read
   5    <file:Documentation/modules.txt>.  If unsure, say `N'.
   6
   7 +NETMAP target support
   8 +CONFIG_IP_NF_TARGET_NETMAP
   9 +  NETMAP is an implementation of static 1:1 NAT mapping of network
  10 +  addresses. It maps the network address part, while keeping the
  11 +  host address part intact. It is similar to Fast NAT, except that
  12 +  Netfilter's connection tracking doesn't work well with Fast NAT.
  13 +
  14 +  If you want to compile it as a module, say M here and read
  15 +  Documentation/modules.txt.  The module will be called
  16 +  ipt_NETMAP.o.  If unsure, say `N'.
  17 +
  18  Packet mangling
  19  CONFIG_IP_NF_MANGLE
  20    This option adds a `mangle' table to iptables: see the man page for
  21 --- a/net/ipv4/netfilter/Config.in
  22 +++ b/net/ipv4/netfilter/Config.in
  23 @@ -63,6 +63,7 @@ if [ "$CONFIG_IP_NF_IPTABLES" != "n" ];
  24        define_bool CONFIG_IP_NF_NAT_NEEDED y
  25        dep_tristate '    MASQUERADE target support' CONFIG_IP_NF_TARGET_MASQUERADE $CONFIG_IP_NF_NAT
  26        dep_tristate '    REDIRECT target support' CONFIG_IP_NF_TARGET_REDIRECT $CONFIG_IP_NF_NAT
  27 +      dep_tristate '    NETMAP target support' CONFIG_IP_NF_TARGET_NETMAP $CONFIG_IP_NF_NAT
  28        if [ "$CONFIG_IP_NF_AMANDA" = "m" ]; then
  29          define_tristate CONFIG_IP_NF_NAT_AMANDA m
  30        else
  31 --- /dev/null
  32 +++ b/net/ipv4/netfilter/ipt_NETMAP.c
  33 @@ -0,0 +1,112 @@
  34 +/* NETMAP - static NAT mapping of IP network addresses (1:1).
  35 +   The mapping can be applied to source (POSTROUTING),
  36 +   destination (PREROUTING), or both (with separate rules).
  37 +
  38 +   Author: Svenning Soerensen <svenning@post5.tele.dk>
  39 +*/
  40 +
  41 +#include <linux/config.h>
  42 +#include <linux/ip.h>
  43 +#include <linux/module.h>
  44 +#include <linux/netdevice.h>
  45 +#include <linux/netfilter.h>
  46 +#include <linux/netfilter_ipv4.h>
  47 +#include <linux/netfilter_ipv4/ip_nat_rule.h>
  48 +
  49 +#define MODULENAME "NETMAP"
  50 +MODULE_LICENSE("GPL");
  51 +MODULE_AUTHOR("Svenning Soerensen <svenning@post5.tele.dk>");
  52 +MODULE_DESCRIPTION("iptables 1:1 NAT mapping of IP networks target");
  53 +
  54 +#if 0
  55 +#define DEBUGP printk
  56 +#else
  57 +#define DEBUGP(format, args...)
  58 +#endif
  59 +
  60 +static int
  61 +check(const char *tablename,
  62 +      const struct ipt_entry *e,
  63 +      void *targinfo,
  64 +      unsigned int targinfosize,
  65 +      unsigned int hook_mask)
  66 +{
  67 +       const struct ip_nat_multi_range *mr = targinfo;
  68 +
  69 +       if (strcmp(tablename, "nat") != 0) {
  70 +               DEBUGP(MODULENAME":check: bad table `%s'.\n", tablename);
  71 +               return 0;
  72 +       }
  73 +       if (targinfosize != IPT_ALIGN(sizeof(*mr))) {
  74 +               DEBUGP(MODULENAME":check: size %u.\n", targinfosize);
  75 +               return 0;
  76 +       }
  77 +       if (hook_mask & ~((1 << NF_IP_PRE_ROUTING) | (1 << NF_IP_POST_ROUTING))) {
  78 +               DEBUGP(MODULENAME":check: bad hooks %x.\n", hook_mask);
  79 +               return 0;
  80 +       }
  81 +       if (!(mr->range[0].flags & IP_NAT_RANGE_MAP_IPS)) {
  82 +               DEBUGP(MODULENAME":check: bad MAP_IPS.\n");
  83 +               return 0;
  84 +       }
  85 +       if (mr->rangesize != 1) {
  86 +               DEBUGP(MODULENAME":check: bad rangesize %u.\n", mr->rangesize);
  87 +               return 0;
  88 +       }
  89 +       return 1;
  90 +}
  91 +
  92 +static unsigned int
  93 +target(struct sk_buff **pskb,
  94 +       unsigned int hooknum,
  95 +       const struct net_device *in,
  96 +       const struct net_device *out,
  97 +       const void *targinfo,
  98 +       void *userinfo)
  99 +{
 100 +       struct ip_conntrack *ct;
 101 +       enum ip_conntrack_info ctinfo;
 102 +       u_int32_t new_ip, netmask;
 103 +       const struct ip_nat_multi_range *mr = targinfo;
 104 +       struct ip_nat_multi_range newrange;
 105 +
 106 +       IP_NF_ASSERT(hooknum == NF_IP_PRE_ROUTING
 107 +                    || hooknum == NF_IP_POST_ROUTING);
 108 +       ct = ip_conntrack_get(*pskb, &ctinfo);
 109 +
 110 +       netmask = ~(mr->range[0].min_ip ^ mr->range[0].max_ip);
 111 +
 112 +       if (hooknum == NF_IP_PRE_ROUTING)
 113 +               new_ip = (*pskb)->nh.iph->daddr & ~netmask;
 114 +       else
 115 +               new_ip = (*pskb)->nh.iph->saddr & ~netmask;
 116 +       new_ip |= mr->range[0].min_ip & netmask;
 117 +
 118 +       newrange = ((struct ip_nat_multi_range)
 119 +       { 1, { { mr->range[0].flags | IP_NAT_RANGE_MAP_IPS,
 120 +                new_ip, new_ip,
 121 +                mr->range[0].min, mr->range[0].max } } });
 122 +
 123 +       /* Hand modified range to generic setup. */
 124 +       return ip_nat_setup_info(ct, &newrange, hooknum);
 125 +}
 126 +
 127 +static struct ipt_target target_module = {
 128 +       .name = MODULENAME,
 129 +       .target = target,
 130 +       .checkentry = check,
 131 +       .me = THIS_MODULE
 132 +};
 133 +
 134 +static int __init init(void)
 135 +{
 136 +       return ipt_register_target(&target_module);
 137 +}
 138 +
 139 +static void __exit fini(void)
 140 +{
 141 +       ipt_unregister_target(&target_module);
 142 +}
 143 +
 144 +module_init(init);
 145 +module_exit(fini);
 146 --- a/net/ipv4/netfilter/Makefile
 147 +++ b/net/ipv4/netfilter/Makefile
 148 @@ -99,6 +99,7 @@ obj-$(CONFIG_IP_NF_TARGET_DSCP) += ipt_D
 149  obj-$(CONFIG_IP_NF_TARGET_MARK) += ipt_MARK.o
 150  obj-$(CONFIG_IP_NF_TARGET_MASQUERADE) += ipt_MASQUERADE.o
 151  obj-$(CONFIG_IP_NF_TARGET_REDIRECT) += ipt_REDIRECT.o
 152 +obj-$(CONFIG_IP_NF_TARGET_NETMAP) += ipt_NETMAP.o
 153  obj-$(CONFIG_IP_NF_NAT_SNMP_BASIC) += ip_nat_snmp_basic.o
 154  obj-$(CONFIG_IP_NF_TARGET_LOG) += ipt_LOG.o
 155  obj-$(CONFIG_IP_NF_TARGET_TTL) += ipt_TTL.o