release/src-rt/linux/linux-2.6/net/ipv4/netfilter/iptable_raw.c

   1 /*
   2  * 'raw' table, which is the very first hooked in at PRE_ROUTING and LOCAL_OUT .
   3  *
   4  * Copyright (C) 2003 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
   5  */
   6 #include <linux/module.h>
   7 #include <linux/netfilter_ipv4/ip_tables.h>
   8 #include <net/ip.h>
   9
  10 #define RAW_VALID_HOOKS ((1 << NF_IP_PRE_ROUTING) | (1 << NF_IP_LOCAL_OUT))
  11
  12 static struct
  13 {
  14         struct ipt_replace repl;
  15         struct ipt_standard entries[2];
  16         struct ipt_error term;
  17 } initial_table __initdata = {
  18         .repl = {
  19                 .name = "raw",
  20                 .valid_hooks = RAW_VALID_HOOKS,
  21                 .num_entries = 3,
  22                 .size = sizeof(struct ipt_standard) * 2 + sizeof(struct ipt_error),
  23                 .hook_entry = {
  24                         [NF_IP_PRE_ROUTING] = 0,
  25                         [NF_IP_LOCAL_OUT] = sizeof(struct ipt_standard)
  26                 },
  27                 .underflow = {
  28                         [NF_IP_PRE_ROUTING] = 0,
  29                         [NF_IP_LOCAL_OUT]  = sizeof(struct ipt_standard)
  30                 },
  31         },
  32         .entries = {
  33                 IPT_STANDARD_INIT(NF_ACCEPT),   /* PRE_ROUTING */
  34                 IPT_STANDARD_INIT(NF_ACCEPT),   /* LOCAL_OUT */
  35         },
  36         .term = IPT_ERROR_INIT,                 /* ERROR */
  37 };
  38
  39 static struct xt_table packet_raw = {
  40         .name = "raw",
  41         .valid_hooks =  RAW_VALID_HOOKS,
  42         .me = THIS_MODULE,
  43         .af = AF_INET,
  44 };
  45
  46 /* The work comes in here from netfilter.c. */
  47 static unsigned int
  48 ipt_hook(unsigned int hook,
  49          struct sk_buff *skb,
  50          const struct net_device *in,
  51          const struct net_device *out,
  52          int (*okfn)(struct sk_buff *))
  53 {
  54         return ipt_do_table(skb, hook, in, out, &packet_raw);
  55 }
  56
  57 static unsigned int
  58 ipt_local_hook(unsigned int hook,
  59                struct sk_buff *skb,
  60                const struct net_device *in,
  61                const struct net_device *out,
  62                int (*okfn)(struct sk_buff *))
  63 {
  64         /* root is playing with raw sockets. */
  65         if (skb->len < sizeof(struct iphdr) ||
  66             ip_hdrlen(skb) < sizeof(struct iphdr)) {
  67                 if (net_ratelimit())
  68                         printk("iptable_raw: ignoring short SOCK_RAW"
  69                                "packet.\n");
  70                 return NF_ACCEPT;
  71         }
  72         return ipt_do_table(skb, hook, in, out, &packet_raw);
  73 }
  74
  75 /* 'raw' is the very first table. */
  76 static struct nf_hook_ops ipt_ops[] = {
  77         {
  78                 .hook = ipt_hook,
  79                 .pf = PF_INET,
  80                 .hooknum = NF_IP_PRE_ROUTING,
  81                 .priority = NF_IP_PRI_RAW,
  82                 .owner = THIS_MODULE,
  83         },
  84         {
  85                 .hook = ipt_local_hook,
  86                 .pf = PF_INET,
  87                 .hooknum = NF_IP_LOCAL_OUT,
  88                 .priority = NF_IP_PRI_RAW,
  89                 .owner = THIS_MODULE,
  90         },
  91 };
  92
  93 static int __init iptable_raw_init(void)
  94 {
  95         int ret;
  96
  97         /* Register table */
  98         ret = ipt_register_table(&packet_raw, &initial_table.repl);
  99         if (ret < 0)
 100                 return ret;
 101
 102         /* Register hooks */
 103         ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
 104         if (ret < 0) {
 105         ipt_unregister_table(&packet_raw);
 106         }
 107
 108         return ret;
 109 }
 110
 111 static void __exit iptable_raw_fini(void)
 112 {
 113         nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
 114         ipt_unregister_table(&packet_raw);
 115 }
 116
 117 module_init(iptable_raw_init);
 118 module_exit(iptable_raw_fini);
 119 MODULE_LICENSE("GPL");