text: /*
   * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/netlink.h>
  #include <linux/netfilter.h>
  #include <linux/netfilter/nf_tables.h>
  #include <net/netfilter/nf_tables.h>
  #include <net/netfilter/nf_nat.h>
  #include <net/netfilter/nft_masq.h>
  
  const struct nla_policy nft_masq_policy[NFTA_MASQ_MAX + 1] = {
  	[NFTA_MASQ_FLAGS]	= { .type = NLA_U32 },
  };
  EXPORT_SYMBOL_GPL(nft_masq_policy);
  
  int nft_masq_init(const struct nft_ctx *ctx,
  		  const struct nft_expr *expr,
  		  const struct nlattr * const tb[])
  {
  	struct nft_masq *priv = nft_expr_priv(expr);
  	int err;
  
  	err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
  	if (err < 0)
  		return err;
  
  	if (tb[NFTA_MASQ_FLAGS] == NULL)
  		return 0;
  
  	priv->flags = ntohl(nla_get_be32(tb[NFTA_MASQ_FLAGS]));
  	if (priv->flags & ~NF_NAT_RANGE_MASK)
  		return -EINVAL;
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(nft_masq_init);
  
  int nft_masq_dump(struct sk_buff *skb, const struct nft_expr *expr)
  {
  	const struct nft_masq *priv = nft_expr_priv(expr);
  
  	if (priv->flags == 0)
  		return 0;
  
  	if (nla_put_be32(skb, NFTA_MASQ_FLAGS, htonl(priv->flags)))
  		goto nla_put_failure;
  
  	return 0;
  
  nla_put_failure:
  	return -1;
  }
  EXPORT_SYMBOL_GPL(nft_masq_dump);
  
  int nft_masq_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
  		      const struct nft_data **data)
  {
  	return nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
  }
  EXPORT_SYMBOL_GPL(nft_masq_validate);
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>");
  