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         [NFTA_MASQ_REG_PROTO_MIN]       = { .type = NLA_U32 },
  22         [NFTA_MASQ_REG_PROTO_MAX]       = { .type = NLA_U32 },
  23 };
  24 EXPORT_SYMBOL_GPL(nft_masq_policy);
  25
  26 int nft_masq_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_POST_ROUTING));
  38 }
  39 EXPORT_SYMBOL_GPL(nft_masq_validate);
  40
  41 int nft_masq_init(const struct nft_ctx *ctx,
  42                   const struct nft_expr *expr,
  43                   const struct nlattr * const tb[])
  44 {
  45         u32 plen = FIELD_SIZEOF(struct nf_nat_range, min_addr.all);
  46         struct nft_masq *priv = nft_expr_priv(expr);
  47         int err;
  48
  49         err = nft_masq_validate(ctx, expr, NULL);
  50         if (err)
  51                 return err;
  52
  53         if (tb[NFTA_MASQ_FLAGS]) {
  54                 priv->flags = ntohl(nla_get_be32(tb[NFTA_MASQ_FLAGS]));
  55                 if (priv->flags & ~NF_NAT_RANGE_MASK)
  56                         return -EINVAL;
  57         }
  58
  59         if (tb[NFTA_MASQ_REG_PROTO_MIN]) {
  60                 priv->sreg_proto_min =
  61                         nft_parse_register(tb[NFTA_MASQ_REG_PROTO_MIN]);
  62
  63                 err = nft_validate_register_load(priv->sreg_proto_min, plen);
  64                 if (err < 0)
  65                         return err;
  66
  67                 if (tb[NFTA_MASQ_REG_PROTO_MAX]) {
  68                         priv->sreg_proto_max =
  69                                 nft_parse_register(tb[NFTA_MASQ_REG_PROTO_MAX]);
  70
  71                         err = nft_validate_register_load(priv->sreg_proto_max,
  72                                                          plen);
  73                         if (err < 0)
  74                                 return err;
  75                 } else {
  76                         priv->sreg_proto_max = priv->sreg_proto_min;
  77                 }
  78         }
  79
  80         return 0;
  81 }
  82 EXPORT_SYMBOL_GPL(nft_masq_init);
  83
  84 int nft_masq_dump(struct sk_buff *skb, const struct nft_expr *expr)
  85 {
  86         const struct nft_masq *priv = nft_expr_priv(expr);
  87
  88         if (priv->flags != 0 &&
  89             nla_put_be32(skb, NFTA_MASQ_FLAGS, htonl(priv->flags)))
  90                 goto nla_put_failure;
  91
  92         if (priv->sreg_proto_min) {
  93                 if (nft_dump_register(skb, NFTA_MASQ_REG_PROTO_MIN,
  94                                       priv->sreg_proto_min) ||
  95                     nft_dump_register(skb, NFTA_MASQ_REG_PROTO_MAX,
  96                                       priv->sreg_proto_max))
  97                         goto nla_put_failure;
  98         }
  99
 100         return 0;
 101
 102 nla_put_failure:
 103         return -1;
 104 }
 105 EXPORT_SYMBOL_GPL(nft_masq_dump);
 106
 107 MODULE_LICENSE("GPL");
 108 MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>");