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 <[email protected]>
   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_pre_exit(struct net *net)
  70 {
  71         if (net->ipv6.ip6table_raw)
  72                 ip6t_unregister_table_pre_exit(net, net->ipv6.ip6table_raw,
  73                                                rawtable_ops);
  74 }
  75
  76 static void __net_exit ip6table_raw_net_exit(struct net *net)
  77 {
  78         if (!net->ipv6.ip6table_raw)
  79                 return;
  80         ip6t_unregister_table_exit(net, net->ipv6.ip6table_raw);
  81         net->ipv6.ip6table_raw = NULL;
  82 }
  83
  84 static struct pernet_operations ip6table_raw_net_ops = {
  85         .pre_exit = ip6table_raw_net_pre_exit,
  86         .exit = ip6table_raw_net_exit,
  87 };
  88
  89 static int __init ip6table_raw_init(void)
  90 {
  91         int ret;
  92         const struct xt_table *table = &packet_raw;
  93
  94         if (raw_before_defrag) {
  95                 table = &packet_raw_before_defrag;
  96
  97                 pr_info("Enabling raw table before defrag\n");
  98         }
  99
 100         /* Register hooks */
 101         rawtable_ops = xt_hook_ops_alloc(table, ip6table_raw_hook);
 102         if (IS_ERR(rawtable_ops))
 103                 return PTR_ERR(rawtable_ops);
 104
 105         ret = register_pernet_subsys(&ip6table_raw_net_ops);
 106         if (ret < 0) {
 107                 kfree(rawtable_ops);
 108                 return ret;
 109         }
 110
 111         ret = ip6table_raw_table_init(&init_net);
 112         if (ret) {
 113                 unregister_pernet_subsys(&ip6table_raw_net_ops);
 114                 kfree(rawtable_ops);
 115         }
 116         return ret;
 117 }
 118
 119 static void __exit ip6table_raw_fini(void)
 120 {
 121         unregister_pernet_subsys(&ip6table_raw_net_ops);
 122         kfree(rawtable_ops);
 123 }
 124
 125 module_init(ip6table_raw_init);
 126 module_exit(ip6table_raw_fini);
 127 MODULE_LICENSE("GPL");