net/netfilter/nft_masq.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/nf_nat.h>
  17 #include <net/netfilter/nft_masq.h>
  18
  19 const struct nla_policy nft_masq_policy[NFTA_MASQ_MAX + 1] = {
  20         [NFTA_MASQ_FLAGS]       = { .type = NLA_U32 },
  21 };
  22 EXPORT_SYMBOL_GPL(nft_masq_policy);
  23
  24 int nft_masq_validate(const struct nft_ctx *ctx,
  25                       const struct nft_expr *expr,
  26                       const struct nft_data **data)
  27 {
  28         int err;
  29
  30         err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
  31         if (err < 0)
  32                 return err;
  33
  34         return nft_chain_validate_hooks(ctx->chain,
  35                                         (1 << NF_INET_POST_ROUTING));
  36 }
  37 EXPORT_SYMBOL_GPL(nft_masq_validate);
  38
  39 int nft_masq_init(const struct nft_ctx *ctx,
  40                   const struct nft_expr *expr,
  41                   const struct nlattr * const tb[])
  42 {
  43         struct nft_masq *priv = nft_expr_priv(expr);
  44         int err;
  45
  46         err = nft_masq_validate(ctx, expr, NULL);
  47         if (err)
  48                 return err;
  49
  50         if (tb[NFTA_MASQ_FLAGS] == NULL)
  51                 return 0;
  52
  53         priv->flags = ntohl(nla_get_be32(tb[NFTA_MASQ_FLAGS]));
  54         if (priv->flags & ~NF_NAT_RANGE_MASK)
  55                 return -EINVAL;
  56
  57         return 0;
  58 }
  59 EXPORT_SYMBOL_GPL(nft_masq_init);
  60
  61 int nft_masq_dump(struct sk_buff *skb, const struct nft_expr *expr)
  62 {
  63         const struct nft_masq *priv = nft_expr_priv(expr);
  64
  65         if (priv->flags == 0)
  66                 return 0;
  67
  68         if (nla_put_be32(skb, NFTA_MASQ_FLAGS, htonl(priv->flags)))
  69                 goto nla_put_failure;
  70
  71         return 0;
  72
  73 nla_put_failure:
  74         return -1;
  75 }
  76 EXPORT_SYMBOL_GPL(nft_masq_dump);
  77
  78 MODULE_LICENSE("GPL");
  79 MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>");