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_validate(const struct nft_ctx *ctx,
  27                        const struct nft_expr *expr,
  28                        const struct nft_data **data)
  29 {
  30         int err;
  31
  32         err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
  33         if (err < 0)
  34                 return err;
  35
  36         return nft_chain_validate_hooks(ctx->chain,
  37                                         (1 << NF_INET_PRE_ROUTING) |
  38                                         (1 << NF_INET_LOCAL_OUT));
  39 }
  40 EXPORT_SYMBOL_GPL(nft_redir_validate);
  41
  42 int nft_redir_init(const struct nft_ctx *ctx,
  43                    const struct nft_expr *expr,
  44                    const struct nlattr * const tb[])
  45 {
  46         struct nft_redir *priv = nft_expr_priv(expr);
  47         unsigned int plen;
  48         int err;
  49
  50         err = nft_redir_validate(ctx, expr, NULL);
  51         if (err < 0)
  52                 return err;
  53
  54         plen = FIELD_SIZEOF(struct nf_nat_range, min_addr.all);
  55         if (tb[NFTA_REDIR_REG_PROTO_MIN]) {
  56                 priv->sreg_proto_min =
  57                         nft_parse_register(tb[NFTA_REDIR_REG_PROTO_MIN]);
  58
  59                 err = nft_validate_register_load(priv->sreg_proto_min, plen);
  60                 if (err < 0)
  61                         return err;
  62
  63                 if (tb[NFTA_REDIR_REG_PROTO_MAX]) {
  64                         priv->sreg_proto_max =
  65                                 nft_parse_register(tb[NFTA_REDIR_REG_PROTO_MAX]);
  66
  67                         err = nft_validate_register_load(priv->sreg_proto_max,
  68                                                          plen);
  69                         if (err < 0)
  70                                 return err;
  71                 } else {
  72                         priv->sreg_proto_max = priv->sreg_proto_min;
  73                 }
  74         }
  75
  76         if (tb[NFTA_REDIR_FLAGS]) {
  77                 priv->flags = ntohl(nla_get_be32(tb[NFTA_REDIR_FLAGS]));
  78                 if (priv->flags & ~NF_NAT_RANGE_MASK)
  79                         return -EINVAL;
  80         }
  81
  82         return 0;
  83 }
  84 EXPORT_SYMBOL_GPL(nft_redir_init);
  85
  86 int nft_redir_dump(struct sk_buff *skb, const struct nft_expr *expr)
  87 {
  88         const struct nft_redir *priv = nft_expr_priv(expr);
  89
  90         if (priv->sreg_proto_min) {
  91                 if (nft_dump_register(skb, NFTA_REDIR_REG_PROTO_MIN,
  92                                       priv->sreg_proto_min))
  93                         goto nla_put_failure;
  94                 if (nft_dump_register(skb, NFTA_REDIR_REG_PROTO_MAX,
  95                                       priv->sreg_proto_max))
  96                         goto nla_put_failure;
  97         }
  98
  99         if (priv->flags != 0 &&
 100             nla_put_be32(skb, NFTA_REDIR_FLAGS, htonl(priv->flags)))
 101                         goto nla_put_failure;
 102
 103         return 0;
 104
 105 nla_put_failure:
 106         return -1;
 107 }
 108 EXPORT_SYMBOL_GPL(nft_redir_dump);
 109
 110 MODULE_LICENSE("GPL");
 111 MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>");