kernel/linux/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 /* Standard entry. */
  12 struct ipt_standard
  13 {
  14         struct ipt_entry entry;
  15         struct ipt_standard_target target;
  16 };
  17
  18 struct ipt_error_target
  19 {
  20         struct ipt_entry_target target;
  21         char errorname[IPT_FUNCTION_MAXNAMELEN];
  22 };
  23
  24 struct ipt_error
  25 {
  26         struct ipt_entry entry;
  27         struct ipt_error_target target;
  28 };
  29
  30 static struct
  31 {
  32         struct ipt_replace repl;
  33         struct ipt_standard entries[2];
  34         struct ipt_error term;
  35 } initial_table __initdata = {
  36         .repl = {
  37                 .name = "raw",
  38                 .valid_hooks = RAW_VALID_HOOKS,
  39                 .num_entries = 3,
  40                 .size = sizeof(struct ipt_standard) * 2 + sizeof(struct ipt_error),
  41                 .hook_entry = {
  42                         [NF_IP_PRE_ROUTING] = 0,
  43                         [NF_IP_LOCAL_OUT] = sizeof(struct ipt_standard) },
  44                 .underflow = {
  45                         [NF_IP_PRE_ROUTING] = 0,
  46                         [NF_IP_LOCAL_OUT]  = sizeof(struct ipt_standard) },
  47         },
  48         .entries = {
  49              /* PRE_ROUTING */
  50              {
  51                      .entry = {
  52                              .target_offset = sizeof(struct ipt_entry),
  53                              .next_offset = sizeof(struct ipt_standard),
  54                      },
  55                      .target = {
  56                           .target = {
  57                                   .u = {
  58                                           .target_size = IPT_ALIGN(sizeof(struct ipt_standard_target)),
  59                                   },
  60                           },
  61                           .verdict = -NF_ACCEPT - 1,
  62                      },
  63              },
  64
  65              /* LOCAL_OUT */
  66              {
  67                      .entry = {
  68                              .target_offset = sizeof(struct ipt_entry),
  69                              .next_offset = sizeof(struct ipt_standard),
  70                      },
  71                      .target = {
  72                              .target = {
  73                                      .u = {
  74                                              .target_size = IPT_ALIGN(sizeof(struct ipt_standard_target)),
  75                                      },
  76                              },
  77                              .verdict = -NF_ACCEPT - 1,
  78                      },
  79              },
  80         },
  81         /* ERROR */
  82         .term = {
  83                 .entry = {
  84                         .target_offset = sizeof(struct ipt_entry),
  85                         .next_offset = sizeof(struct ipt_error),
  86                 },
  87                 .target = {
  88                         .target = {
  89                                 .u = {
  90                                         .user = {
  91                                                 .target_size = IPT_ALIGN(sizeof(struct ipt_error_target)),
  92                                                 .name = IPT_ERROR_TARGET,
  93                                         },
  94                                 },
  95                         },
  96                         .errorname = "ERROR",
  97                 },
  98         }
  99 };
 100
 101 static struct ipt_table packet_raw = {
 102         .name = "raw",
 103         .table = &initial_table.repl,
 104         .valid_hooks =  RAW_VALID_HOOKS,
 105         .lock = RW_LOCK_UNLOCKED,
 106         .me = THIS_MODULE
 107 };
 108
 109 /* The work comes in here from netfilter.c. */
 110 static unsigned int
 111 ipt_hook(unsigned int hook,
 112          struct sk_buff **pskb,
 113          const struct net_device *in,
 114          const struct net_device *out,
 115          int (*okfn)(struct sk_buff *))
 116 {
 117         return ipt_do_table(pskb, hook, in, out, &packet_raw, NULL);
 118 }
 119
 120 /* 'raw' is the very first table. */
 121 static struct nf_hook_ops ipt_ops[] = {
 122         {
 123           .hook = ipt_hook,
 124           .pf = PF_INET,
 125           .hooknum = NF_IP_PRE_ROUTING,
 126           .priority = NF_IP_PRI_RAW
 127         },
 128         {
 129           .hook = ipt_hook,
 130           .pf = PF_INET,
 131           .hooknum = NF_IP_LOCAL_OUT,
 132           .priority = NF_IP_PRI_RAW
 133         },
 134 };
 135
 136 static int __init init(void)
 137 {
 138         int ret;
 139
 140         /* Register table */
 141         ret = ipt_register_table(&packet_raw);
 142         if (ret < 0)
 143                 return ret;
 144
 145         /* Register hooks */
 146         ret = nf_register_hook(&ipt_ops[0]);
 147         if (ret < 0)
 148                 goto cleanup_table;
 149
 150         ret = nf_register_hook(&ipt_ops[1]);
 151         if (ret < 0)
 152                 goto cleanup_hook0;
 153
 154         return ret;
 155
 156  cleanup_hook0:
 157         nf_unregister_hook(&ipt_ops[0]);
 158  cleanup_table:
 159         ipt_unregister_table(&packet_raw);
 160
 161         return ret;
 162 }
 163
 164 static void __exit fini(void)
 165 {
 166         unsigned int i;
 167
 168         for (i = 0; i < sizeof(ipt_ops)/sizeof(struct nf_hook_ops); i++)
 169                 nf_unregister_hook(&ipt_ops[i]);
 170
 171         ipt_unregister_table(&packet_raw);
 172 }
 173
 174 module_init(init);
 175 module_exit(fini);
 176 MODULE_LICENSE("GPL");