LXR linux/net/ipv4/netfilter/nft_masq

   1/*
   2 * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo@debian.org>
   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
  19static 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 = (__force __be16)nft_reg_load16(
  30                        &regs->data[priv->sreg_proto_min]);
  31                range.max_proto.all = (__force __be16)nft_reg_load16(
  32                        &regs->data[priv->sreg_proto_max]);
  33        }
  34        regs->verdict.code = nf_nat_masquerade_ipv4(pkt->skb, nft_hook(pkt),
  35                                                    &range, nft_out(pkt));
  36}
  37
  38static void
  39nft_masq_ipv4_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
  40{
  41        nf_ct_netns_put(ctx->net, NFPROTO_IPV4);
  42}
  43
  44static struct nft_expr_type nft_masq_ipv4_type;
  45static const struct nft_expr_ops nft_masq_ipv4_ops = {
  46        .type           = &nft_masq_ipv4_type,
  47        .size           = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
  48        .eval           = nft_masq_ipv4_eval,
  49        .init           = nft_masq_init,
  50        .destroy        = nft_masq_ipv4_destroy,
  51        .dump           = nft_masq_dump,
  52        .validate       = nft_masq_validate,
  53};
  54
  55static struct nft_expr_type nft_masq_ipv4_type __read_mostly = {
  56        .family         = NFPROTO_IPV4,
  57        .name           = "masq",
  58        .ops            = &nft_masq_ipv4_ops,
  59        .policy         = nft_masq_policy,
  60        .maxattr        = NFTA_MASQ_MAX,
  61        .owner          = THIS_MODULE,
  62};
  63
  64static int __init nft_masq_ipv4_module_init(void)
  65{
  66        int ret;
  67
  68        ret = nft_register_expr(&nft_masq_ipv4_type);
  69        if (ret < 0)
  70                return ret;
  71
  72        nf_nat_masquerade_ipv4_register_notifier();
  73
  74        return ret;
  75}
  76
  77static void __exit nft_masq_ipv4_module_exit(void)
  78{
  79        nft_unregister_expr(&nft_masq_ipv4_type);
  80        nf_nat_masquerade_ipv4_unregister_notifier();
  81}
  82
  83module_init(nft_masq_ipv4_module_init);
  84module_exit(nft_masq_ipv4_module_exit);
  85
  86MODULE_LICENSE("GPL");
  87MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo@debian.org");
  88MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "masq");
  89