net/ipv4/netfilter/nft_masq_ipv4.c

   1 /*
   2  * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/netlink.h>
  13 #include <linux/netfilter.h>
  14 #include <linux/netfilter/nf_tables.h>
  15 #include <net/netfilter/nf_tables.h>
  16 #include <net/netfilter/nft_masq.h>
  17 #include <net/netfilter/ipv4/nf_nat_masquerade.h>
  18
  19 static void nft_masq_ipv4_eval(const struct nft_expr *expr,
  20                                struct nft_data data[NFT_REG_MAX + 1],
  21                                const struct nft_pktinfo *pkt)
  22 {
  23         struct nft_masq *priv = nft_expr_priv(expr);
  24         struct nf_nat_range range;
  25         unsigned int verdict;
  26
  27         range.flags = priv->flags;
  28
  29         verdict = nf_nat_masquerade_ipv4(pkt->skb, pkt->ops->hooknum,
  30                                          &range, pkt->out);
  31
  32         data[NFT_REG_VERDICT].verdict = verdict;
  33 }
  34
  35 static struct nft_expr_type nft_masq_ipv4_type;
  36 static const struct nft_expr_ops nft_masq_ipv4_ops = {
  37         .type           = &nft_masq_ipv4_type,
  38         .size           = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
  39         .eval           = nft_masq_ipv4_eval,
  40         .init           = nft_masq_init,
  41         .dump           = nft_masq_dump,
  42         .validate       = nft_masq_validate,
  43 };
  44
  45 static struct nft_expr_type nft_masq_ipv4_type __read_mostly = {
  46         .family         = NFPROTO_IPV4,
  47         .name           = "masq",
  48         .ops            = &nft_masq_ipv4_ops,
  49         .policy         = nft_masq_policy,
  50         .maxattr        = NFTA_MASQ_MAX,
  51         .owner          = THIS_MODULE,
  52 };
  53
  54 static int __init nft_masq_ipv4_module_init(void)
  55 {
  56         int ret;
  57
  58         ret = nft_register_expr(&nft_masq_ipv4_type);
  59         if (ret < 0)
  60                 return ret;
  61
  62         nf_nat_masquerade_ipv4_register_notifier();
  63
  64         return ret;
  65 }
  66
  67 static void __exit nft_masq_ipv4_module_exit(void)
  68 {
  69         nft_unregister_expr(&nft_masq_ipv4_type);
  70         nf_nat_masquerade_ipv4_unregister_notifier();
  71 }
  72
  73 module_init(nft_masq_ipv4_module_init);
  74 module_exit(nft_masq_ipv4_module_exit);
  75
  76 MODULE_LICENSE("GPL");
  77 MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>");
  78 MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "masq");