net/ipv6/netfilter/ip6table_raw.c

   1 /*
   2  * IPv6 raw table, a port of the IPv4 raw table to IPv6
   3  *
   4  * Copyright (C) 2003 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
   5  */
   6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   7 #include <linux/module.h>
   8 #include <linux/netfilter_ipv6/ip6_tables.h>
   9 #include <linux/slab.h>
  10
  11 #define RAW_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_OUT))
  12
  13 static int __net_init ip6table_raw_table_init(struct net *net);
  14
  15 static bool raw_before_defrag __read_mostly;
  16 MODULE_PARM_DESC(raw_before_defrag, "Enable raw table before defrag");
  17 module_param(raw_before_defrag, bool, 0000);
  18
  19 static const struct xt_table packet_raw = {
  20         .name = "raw",
  21         .valid_hooks = RAW_VALID_HOOKS,
  22         .me = THIS_MODULE,
  23         .af = NFPROTO_IPV6,
  24         .priority = NF_IP6_PRI_RAW,
  25         .table_init = ip6table_raw_table_init,
  26 };
  27
  28 static const struct xt_table packet_raw_before_defrag = {
  29         .name = "raw",
  30         .valid_hooks = RAW_VALID_HOOKS,
  31         .me = THIS_MODULE,
  32         .af = NFPROTO_IPV6,
  33         .priority = NF_IP6_PRI_RAW_BEFORE_DEFRAG,
  34         .table_init = ip6table_raw_table_init,
  35 };
  36
  37 /* The work comes in here from netfilter.c. */
  38 static unsigned int
  39 ip6table_raw_hook(void *priv, struct sk_buff *skb,
  40                   const struct nf_hook_state *state)
  41 {
  42         return ip6t_do_table(skb, state, state->net->ipv6.ip6table_raw);
  43 }
  44
  45 static struct nf_hook_ops *rawtable_ops __read_mostly;
  46
  47 static int __net_init ip6table_raw_table_init(struct net *net)
  48 {
  49         struct ip6t_replace *repl;
  50         const struct xt_table *table = &packet_raw;
  51         int ret;
  52
  53         if (raw_before_defrag)
  54                 table = &packet_raw_before_defrag;
  55
  56         if (net->ipv6.ip6table_raw)
  57                 return 0;
  58
  59         repl = ip6t_alloc_initial_table(table);
  60         if (repl == NULL)
  61                 return -ENOMEM;
  62         ret = ip6t_register_table(net, table, repl, rawtable_ops,
  63                                   &net->ipv6.ip6table_raw);
  64         kfree(repl);
  65         return ret;
  66 }
  67
  68 static void __net_exit ip6table_raw_net_exit(struct net *net)
  69 {
  70         if (!net->ipv6.ip6table_raw)
  71                 return;
  72         ip6t_unregister_table(net, net->ipv6.ip6table_raw, rawtable_ops);
  73         net->ipv6.ip6table_raw = NULL;
  74 }
  75
  76 static struct pernet_operations ip6table_raw_net_ops = {
  77         .exit = ip6table_raw_net_exit,
  78 };
  79
  80 static int __init ip6table_raw_init(void)
  81 {
  82         int ret;
  83         const struct xt_table *table = &packet_raw;
  84
  85         if (raw_before_defrag) {
  86                 table = &packet_raw_before_defrag;
  87
  88                 pr_info("Enabling raw table before defrag\n");
  89         }
  90
  91         /* Register hooks */
  92         rawtable_ops = xt_hook_ops_alloc(table, ip6table_raw_hook);
  93         if (IS_ERR(rawtable_ops))
  94                 return PTR_ERR(rawtable_ops);
  95
  96         ret = register_pernet_subsys(&ip6table_raw_net_ops);
  97         if (ret < 0) {
  98                 kfree(rawtable_ops);
  99                 return ret;
 100         }
 101
 102         ret = ip6table_raw_table_init(&init_net);
 103         if (ret) {
 104                 unregister_pernet_subsys(&ip6table_raw_net_ops);
 105                 kfree(rawtable_ops);
 106         }
 107         return ret;
 108 }
 109
 110 static void __exit ip6table_raw_fini(void)
 111 {
 112         unregister_pernet_subsys(&ip6table_raw_net_ops);
 113         kfree(rawtable_ops);
 114 }
 115
 116 module_init(ip6table_raw_init);
 117 module_exit(ip6table_raw_fini);
 118 MODULE_LICENSE("GPL");