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_regs *regs,
  21                                const struct nft_pktinfo *pkt)
  22 {
  23         struct nft_masq *priv = nft_expr_priv(expr);
  24         struct nf_nat_range range;
  25
  26         memset(&range, 0, sizeof(range));
  27         range.flags = priv->flags;
  28         if (priv->sreg_proto_min) {
  29                 range.min_proto.all =
  30                         *(__be16 *)&regs->data[priv->sreg_proto_min];
  31                 range.max_proto.all =
  32                         *(__be16 *)&regs->data[priv->sreg_proto_max];
  33         }
  34         regs->verdict.code = nf_nat_masquerade_ipv4(pkt->skb, pkt->hook,
  35                                                     &range, pkt->out);
  36 }
  37
  38 static struct nft_expr_type nft_masq_ipv4_type;
  39 static const struct nft_expr_ops nft_masq_ipv4_ops = {
  40         .type           = &nft_masq_ipv4_type,
  41         .size           = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
  42         .eval           = nft_masq_ipv4_eval,
  43         .init           = nft_masq_init,
  44         .dump           = nft_masq_dump,
  45         .validate       = nft_masq_validate,
  46 };
  47
  48 static struct nft_expr_type nft_masq_ipv4_type __read_mostly = {
  49         .family         = NFPROTO_IPV4,
  50         .name           = "masq",
  51         .ops            = &nft_masq_ipv4_ops,
  52         .policy         = nft_masq_policy,
  53         .maxattr        = NFTA_MASQ_MAX,
  54         .owner          = THIS_MODULE,
  55 };
  56
  57 static int __init nft_masq_ipv4_module_init(void)
  58 {
  59         int ret;
  60
  61         ret = nft_register_expr(&nft_masq_ipv4_type);
  62         if (ret < 0)
  63                 return ret;
  64
  65         nf_nat_masquerade_ipv4_register_notifier();
  66
  67         return ret;
  68 }
  69
  70 static void __exit nft_masq_ipv4_module_exit(void)
  71 {
  72         nft_unregister_expr(&nft_masq_ipv4_type);
  73         nf_nat_masquerade_ipv4_unregister_notifier();
  74 }
  75
  76 module_init(nft_masq_ipv4_module_init);
  77 module_exit(nft_masq_ipv4_module_exit);
  78
  79 MODULE_LICENSE("GPL");
  80 MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>");
  81 MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "masq");