net/ipv6/netfilter/ip6table_raw.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * IPv6 raw table, a port of the IPv4 raw table to IPv6
   4  *
   5  * Copyright (C) 2003 Jozsef Kadlecsik <kadlec@netfilter.org>
   6  */
   7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   8 #include <linux/module.h>
   9 #include <linux/netfilter_ipv6/ip6_tables.h>
  10 #include <linux/slab.h>
  11
  12 #define RAW_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_OUT))
  13
  14 static int __net_init ip6table_raw_table_init(struct net *net);
  15
  16 static bool raw_before_defrag __read_mostly;
  17 MODULE_PARM_DESC(raw_before_defrag, "Enable raw table before defrag");
  18 module_param(raw_before_defrag, bool, 0000);
  19
  20 static const struct xt_table packet_raw = {
  21         .name = "raw",
  22         .valid_hooks = RAW_VALID_HOOKS,
  23         .me = THIS_MODULE,
  24         .af = NFPROTO_IPV6,
  25         .priority = NF_IP6_PRI_RAW,
  26         .table_init = ip6table_raw_table_init,
  27 };
  28
  29 static const struct xt_table packet_raw_before_defrag = {
  30         .name = "raw",
  31         .valid_hooks = RAW_VALID_HOOKS,
  32         .me = THIS_MODULE,
  33         .af = NFPROTO_IPV6,
  34         .priority = NF_IP6_PRI_RAW_BEFORE_DEFRAG,
  35         .table_init = ip6table_raw_table_init,
  36 };
  37
  38 /* The work comes in here from netfilter.c. */
  39 static unsigned int
  40 ip6table_raw_hook(void *priv, struct sk_buff *skb,
  41                   const struct nf_hook_state *state)
  42 {
  43         return ip6t_do_table(skb, state, state->net->ipv6.ip6table_raw);
  44 }
  45
  46 static struct nf_hook_ops *rawtable_ops __read_mostly;
  47
  48 static int __net_init ip6table_raw_table_init(struct net *net)
  49 {
  50         struct ip6t_replace *repl;
  51         const struct xt_table *table = &packet_raw;
  52         int ret;
  53
  54         if (raw_before_defrag)
  55                 table = &packet_raw_before_defrag;
  56
  57         if (net->ipv6.ip6table_raw)
  58                 return 0;
  59
  60         repl = ip6t_alloc_initial_table(table);
  61         if (repl == NULL)
  62                 return -ENOMEM;
  63         ret = ip6t_register_table(net, table, repl, rawtable_ops,
  64                                   &net->ipv6.ip6table_raw);
  65         kfree(repl);
  66         return ret;
  67 }
  68
  69 static void __net_exit ip6table_raw_net_exit(struct net *net)
  70 {
  71         if (!net->ipv6.ip6table_raw)
  72                 return;
  73         ip6t_unregister_table(net, net->ipv6.ip6table_raw, rawtable_ops);
  74         net->ipv6.ip6table_raw = NULL;
  75 }
  76
  77 static struct pernet_operations ip6table_raw_net_ops = {
  78         .exit = ip6table_raw_net_exit,
  79 };
  80
  81 static int __init ip6table_raw_init(void)
  82 {
  83         int ret;
  84         const struct xt_table *table = &packet_raw;
  85
  86         if (raw_before_defrag) {
  87                 table = &packet_raw_before_defrag;
  88
  89                 pr_info("Enabling raw table before defrag\n");
  90         }
  91
  92         /* Register hooks */
  93         rawtable_ops = xt_hook_ops_alloc(table, ip6table_raw_hook);
  94         if (IS_ERR(rawtable_ops))
  95                 return PTR_ERR(rawtable_ops);
  96
  97         ret = register_pernet_subsys(&ip6table_raw_net_ops);
  98         if (ret < 0) {
  99                 kfree(rawtable_ops);
 100                 return ret;
 101         }
 102
 103         ret = ip6table_raw_table_init(&init_net);
 104         if (ret) {
 105                 unregister_pernet_subsys(&ip6table_raw_net_ops);
 106                 kfree(rawtable_ops);
 107         }
 108         return ret;
 109 }
 110
 111 static void __exit ip6table_raw_fini(void)
 112 {
 113         unregister_pernet_subsys(&ip6table_raw_net_ops);
 114         kfree(rawtable_ops);
 115 }
 116
 117 module_init(ip6table_raw_init);
 118 module_exit(ip6table_raw_fini);
 119 MODULE_LICENSE("GPL");