net/netfilter/nft_redir.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_nat.h>
  16 #include <net/netfilter/nf_tables.h>
  17 #include <net/netfilter/nft_redir.h>
  18
  19 const struct nla_policy nft_redir_policy[NFTA_REDIR_MAX + 1] = {
  20         [NFTA_REDIR_REG_PROTO_MIN]      = { .type = NLA_U32 },
  21         [NFTA_REDIR_REG_PROTO_MAX]      = { .type = NLA_U32 },
  22         [NFTA_REDIR_FLAGS]              = { .type = NLA_U32 },
  23 };
  24 EXPORT_SYMBOL_GPL(nft_redir_policy);
  25
  26 int nft_redir_init(const struct nft_ctx *ctx,
  27                    const struct nft_expr *expr,
  28                    const struct nlattr * const tb[])
  29 {
  30         struct nft_redir *priv = nft_expr_priv(expr);
  31         int err;
  32
  33         err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
  34         if (err < 0)
  35                 return err;
  36
  37         if (tb[NFTA_REDIR_REG_PROTO_MIN]) {
  38                 priv->sreg_proto_min =
  39                         ntohl(nla_get_be32(tb[NFTA_REDIR_REG_PROTO_MIN]));
  40
  41                 err = nft_validate_input_register(priv->sreg_proto_min);
  42                 if (err < 0)
  43                         return err;
  44
  45                 if (tb[NFTA_REDIR_REG_PROTO_MAX]) {
  46                         priv->sreg_proto_max =
  47                                 ntohl(nla_get_be32(tb[NFTA_REDIR_REG_PROTO_MAX]));
  48
  49                         err = nft_validate_input_register(priv->sreg_proto_max);
  50                         if (err < 0)
  51                                 return err;
  52                 } else {
  53                         priv->sreg_proto_max = priv->sreg_proto_min;
  54                 }
  55         }
  56
  57         if (tb[NFTA_REDIR_FLAGS]) {
  58                 priv->flags = ntohl(nla_get_be32(tb[NFTA_REDIR_FLAGS]));
  59                 if (priv->flags & ~NF_NAT_RANGE_MASK)
  60                         return -EINVAL;
  61         }
  62
  63         return 0;
  64 }
  65 EXPORT_SYMBOL_GPL(nft_redir_init);
  66
  67 int nft_redir_dump(struct sk_buff *skb, const struct nft_expr *expr)
  68 {
  69         const struct nft_redir *priv = nft_expr_priv(expr);
  70
  71         if (priv->sreg_proto_min) {
  72                 if (nla_put_be32(skb, NFTA_REDIR_REG_PROTO_MIN,
  73                                  htonl(priv->sreg_proto_min)))
  74                         goto nla_put_failure;
  75                 if (nla_put_be32(skb, NFTA_REDIR_REG_PROTO_MAX,
  76                                  htonl(priv->sreg_proto_max)))
  77                         goto nla_put_failure;
  78         }
  79
  80         if (priv->flags != 0 &&
  81             nla_put_be32(skb, NFTA_REDIR_FLAGS, htonl(priv->flags)))
  82                         goto nla_put_failure;
  83
  84         return 0;
  85
  86 nla_put_failure:
  87         return -1;
  88 }
  89 EXPORT_SYMBOL_GPL(nft_redir_dump);
  90
  91 int nft_redir_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
  92                        const struct nft_data **data)
  93 {
  94         return nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
  95 }
  96 EXPORT_SYMBOL_GPL(nft_redir_validate);
  97
  98 MODULE_LICENSE("GPL");
  99 MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>");