net/netfilter/nft_redir.c

   1 /*
   2  * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo@debian.org>
   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         plen = FIELD_SIZEOF(struct nf_nat_range, min_addr.all);
  51         if (tb[NFTA_REDIR_REG_PROTO_MIN]) {
  52                 priv->sreg_proto_min =
  53                         nft_parse_register(tb[NFTA_REDIR_REG_PROTO_MIN]);
  54
  55                 err = nft_validate_register_load(priv->sreg_proto_min, plen);
  56                 if (err < 0)
  57                         return err;
  58
  59                 if (tb[NFTA_REDIR_REG_PROTO_MAX]) {
  60                         priv->sreg_proto_max =
  61                                 nft_parse_register(tb[NFTA_REDIR_REG_PROTO_MAX]);
  62
  63                         err = nft_validate_register_load(priv->sreg_proto_max,
  64                                                          plen);
  65                         if (err < 0)
  66                                 return err;
  67                 } else {
  68                         priv->sreg_proto_max = priv->sreg_proto_min;
  69                 }
  70         }
  71
  72         if (tb[NFTA_REDIR_FLAGS]) {
  73                 priv->flags = ntohl(nla_get_be32(tb[NFTA_REDIR_FLAGS]));
  74                 if (priv->flags & ~NF_NAT_RANGE_MASK)
  75                         return -EINVAL;
  76         }
  77
  78         return nf_ct_netns_get(ctx->net, ctx->afi->family);
  79 }
  80 EXPORT_SYMBOL_GPL(nft_redir_init);
  81
  82 int nft_redir_dump(struct sk_buff *skb, const struct nft_expr *expr)
  83 {
  84         const struct nft_redir *priv = nft_expr_priv(expr);
  85
  86         if (priv->sreg_proto_min) {
  87                 if (nft_dump_register(skb, NFTA_REDIR_REG_PROTO_MIN,
  88                                       priv->sreg_proto_min))
  89                         goto nla_put_failure;
  90                 if (nft_dump_register(skb, NFTA_REDIR_REG_PROTO_MAX,
  91                                       priv->sreg_proto_max))
  92                         goto nla_put_failure;
  93         }
  94
  95         if (priv->flags != 0 &&
  96             nla_put_be32(skb, NFTA_REDIR_FLAGS, htonl(priv->flags)))
  97                         goto nla_put_failure;
  98
  99         return 0;
 100
 101 nla_put_failure:
 102         return -1;
 103 }
 104 EXPORT_SYMBOL_GPL(nft_redir_dump);
 105
 106 MODULE_LICENSE("GPL");
 107 MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo@debian.org>");