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 ipt_table packet_raw = {
  83         .name = "raw",
  84         .valid_hooks =  RAW_VALID_HOOKS,
  85         .lock = RW_LOCK_UNLOCKED,
  86         .me = THIS_MODULE
  87 };
  88
  89 /* The work comes in here from netfilter.c. */
  90 static unsigned int
  91 ipt_hook(unsigned int hook,
  92          struct sk_buff **pskb,
  93          const struct net_device *in,
  94          const struct net_device *out,
  95          int (*okfn)(struct sk_buff *))
  96 {
  97         return ipt_do_table(pskb, hook, in, out, &packet_raw, NULL);
  98 }
  99
 100 /* 'raw' is the very first table. */
 101 static struct nf_hook_ops ipt_ops[] = {
 102         {
 103           .hook = ipt_hook,
 104           .pf = PF_INET,
 105           .hooknum = NF_IP_PRE_ROUTING,
 106           .priority = NF_IP_PRI_RAW
 107         },
 108         {
 109           .hook = ipt_hook,
 110           .pf = PF_INET,
 111           .hooknum = NF_IP_LOCAL_OUT,
 112           .priority = NF_IP_PRI_RAW
 113         },
 114 };
 115
 116 static int __init init(void)
 117 {
 118         int ret;
 119
 120         /* Register table */
 121         ret = ipt_register_table(&packet_raw, &initial_table.repl);
 122         if (ret < 0)
 123                 return ret;
 124
 125         /* Register hooks */
 126         ret = nf_register_hook(&ipt_ops[0]);
 127         if (ret < 0)
 128                 goto cleanup_table;
 129
 130         ret = nf_register_hook(&ipt_ops[1]);
 131         if (ret < 0)
 132                 goto cleanup_hook0;
 133
 134         return ret;
 135
 136  cleanup_hook0:
 137         nf_unregister_hook(&ipt_ops[0]);
 138  cleanup_table:
 139         ipt_unregister_table(&packet_raw);
 140
 141         return ret;
 142 }
 143
 144 static void __exit fini(void)
 145 {
 146         unsigned int i;
 147
 148         for (i = 0; i < sizeof(ipt_ops)/sizeof(struct nf_hook_ops); i++)
 149                 nf_unregister_hook(&ipt_ops[i]);
 150
 151         ipt_unregister_table(&packet_raw);
 152 }
 153
 154 module_init(init);
 155 module_exit(fini);
 156 MODULE_LICENSE("GPL");