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
   9 #define RAW_VALID_HOOKS ((1 << NF_IP_PRE_ROUTING) | (1 << NF_IP_LOCAL_OUT))
  10
  11 static struct
  12 {
  13         struct ipt_replace repl;
  14         struct ipt_standard entries[2];
  15         struct ipt_error term;
  16 } initial_table __initdata = {
  17         .repl = {
  18                 .name = "raw",
  19                 .valid_hooks = RAW_VALID_HOOKS,
  20                 .num_entries = 3,
  21                 .size = sizeof(struct ipt_standard) * 2 + sizeof(struct ipt_error),
  22                 .hook_entry = {
  23                         [NF_IP_PRE_ROUTING] = 0,
  24                         [NF_IP_LOCAL_OUT] = sizeof(struct ipt_standard) },
  25                 .underflow = {
  26                         [NF_IP_PRE_ROUTING] = 0,
  27                         [NF_IP_LOCAL_OUT]  = sizeof(struct ipt_standard) },
  28         },
  29         .entries = {
  30              /* PRE_ROUTING */
  31              {
  32                      .entry = {
  33                              .target_offset = sizeof(struct ipt_entry),
  34                              .next_offset = sizeof(struct ipt_standard),
  35                      },
  36                      .target = {
  37                           .target = {
  38                                   .u = {
  39                                           .target_size = IPT_ALIGN(sizeof(struct ipt_standard_target)),
  40                                   },
  41                           },
  42                           .verdict = -NF_ACCEPT - 1,
  43                      },
  44              },
  45
  46              /* LOCAL_OUT */
  47              {
  48                      .entry = {
  49                              .target_offset = sizeof(struct ipt_entry),
  50                              .next_offset = sizeof(struct ipt_standard),
  51                      },
  52                      .target = {
  53                              .target = {
  54                                      .u = {
  55                                              .target_size = IPT_ALIGN(sizeof(struct ipt_standard_target)),
  56                                      },
  57                              },
  58                              .verdict = -NF_ACCEPT - 1,
  59                      },
  60              },
  61         },
  62         /* ERROR */
  63         .term = {
  64                 .entry = {
  65                         .target_offset = sizeof(struct ipt_entry),
  66                         .next_offset = sizeof(struct ipt_error),
  67                 },
  68                 .target = {
  69                         .target = {
  70                                 .u = {
  71                                         .user = {
  72                                                 .target_size = IPT_ALIGN(sizeof(struct ipt_error_target)),
  73                                                 .name = IPT_ERROR_TARGET,
  74                                         },
  75                                 },
  76                         },
  77                         .errorname = "ERROR",
  78                 },
  79         }
  80 };
  81
  82 static struct xt_table packet_raw = {
  83         .name = "raw",
  84         .valid_hooks =  RAW_VALID_HOOKS,
  85         .lock = RW_LOCK_UNLOCKED,
  86         .me = THIS_MODULE,
  87         .af = AF_INET,
  88 };
  89
  90 /* The work comes in here from netfilter.c. */
  91 static unsigned int
  92 ipt_hook(unsigned int hook,
  93          struct sk_buff **pskb,
  94          const struct net_device *in,
  95          const struct net_device *out,
  96          int (*okfn)(struct sk_buff *))
  97 {
  98         return ipt_do_table(pskb, hook, in, out, &packet_raw);
  99 }
 100
 101 /* 'raw' is the very first table. */
 102 static struct nf_hook_ops ipt_ops[] = {
 103         {
 104                 .hook = ipt_hook,
 105                 .pf = PF_INET,
 106                 .hooknum = NF_IP_PRE_ROUTING,
 107                 .priority = NF_IP_PRI_RAW,
 108                 .owner = THIS_MODULE,
 109         },
 110         {
 111                 .hook = ipt_hook,
 112                 .pf = PF_INET,
 113                 .hooknum = NF_IP_LOCAL_OUT,
 114                 .priority = NF_IP_PRI_RAW,
 115                 .owner = THIS_MODULE,
 116         },
 117 };
 118
 119 static int __init iptable_raw_init(void)
 120 {
 121         int ret;
 122
 123         /* Register table */
 124         ret = ipt_register_table(&packet_raw, &initial_table.repl);
 125         if (ret < 0)
 126                 return ret;
 127
 128         /* Register hooks */
 129         ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
 130         if (ret < 0)
 131                 goto cleanup_table;
 132
 133         return ret;
 134
 135  cleanup_table:
 136         ipt_unregister_table(&packet_raw);
 137         return ret;
 138 }
 139
 140 static void __exit iptable_raw_fini(void)
 141 {
 142         nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
 143         ipt_unregister_table(&packet_raw);
 144 }
 145
 146 module_init(iptable_raw_init);
 147 module_exit(iptable_raw_fini);
 148 MODULE_LICENSE("GPL");