LXR linux/net/ipv6/netfilter/ip6table

   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
  14static int __net_init ip6table_raw_table_init(struct net *net);
  15
  16static bool raw_before_defrag __read_mostly;
  17MODULE_PARM_DESC(raw_before_defrag, "Enable raw table before defrag");
  18module_param(raw_before_defrag, bool, 0000);
  19
  20static 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
  29static 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. */
  39static unsigned int
  40ip6table_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
  46static struct nf_hook_ops *rawtable_ops __read_mostly;
  47
  48static 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
  69static 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
  77static struct pernet_operations ip6table_raw_net_ops = {
  78        .exit = ip6table_raw_net_exit,
  79};
  80
  81static 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
 111static void __exit ip6table_raw_fini(void)
 112{
 113        unregister_pernet_subsys(&ip6table_raw_net_ops);
 114        kfree(rawtable_ops);
 115}
 116
 117module_init(ip6table_raw_init);
 118module_exit(ip6table_raw_fini);
 119MODULE_LICENSE("GPL");
 120