net/ipv6/netfilter/nft_dup_ipv6.c

   1 /*
   2  * Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 as published by
   6  * 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/ipv6/nf_dup_ipv6.h>
  17
  18 struct nft_dup_ipv6 {
  19         enum nft_registers      sreg_addr:8;
  20         enum nft_registers      sreg_dev:8;
  21 };
  22
  23 static void nft_dup_ipv6_eval(const struct nft_expr *expr,
  24                               struct nft_regs *regs,
  25                               const struct nft_pktinfo *pkt)
  26 {
  27         struct nft_dup_ipv6 *priv = nft_expr_priv(expr);
  28         struct in6_addr *gw = (struct in6_addr *)&regs->data[priv->sreg_addr];
  29         int oif = regs->data[priv->sreg_dev];
  30
  31         nf_dup_ipv6(pkt->net, pkt->skb, pkt->hook, gw, oif);
  32 }
  33
  34 static int nft_dup_ipv6_init(const struct nft_ctx *ctx,
  35                              const struct nft_expr *expr,
  36                              const struct nlattr * const tb[])
  37 {
  38         struct nft_dup_ipv6 *priv = nft_expr_priv(expr);
  39         int err;
  40
  41         if (tb[NFTA_DUP_SREG_ADDR] == NULL)
  42                 return -EINVAL;
  43
  44         priv->sreg_addr = nft_parse_register(tb[NFTA_DUP_SREG_ADDR]);
  45         err = nft_validate_register_load(priv->sreg_addr, sizeof(struct in6_addr));
  46         if (err < 0)
  47                 return err;
  48
  49         if (tb[NFTA_DUP_SREG_DEV] != NULL) {
  50                 priv->sreg_dev = nft_parse_register(tb[NFTA_DUP_SREG_DEV]);
  51                 return nft_validate_register_load(priv->sreg_dev, sizeof(int));
  52         }
  53         return 0;
  54 }
  55
  56 static int nft_dup_ipv6_dump(struct sk_buff *skb, const struct nft_expr *expr)
  57 {
  58         struct nft_dup_ipv6 *priv = nft_expr_priv(expr);
  59
  60         if (nft_dump_register(skb, NFTA_DUP_SREG_ADDR, priv->sreg_addr) ||
  61             nft_dump_register(skb, NFTA_DUP_SREG_DEV, priv->sreg_dev))
  62                 goto nla_put_failure;
  63
  64         return 0;
  65
  66 nla_put_failure:
  67         return -1;
  68 }
  69
  70 static struct nft_expr_type nft_dup_ipv6_type;
  71 static const struct nft_expr_ops nft_dup_ipv6_ops = {
  72         .type           = &nft_dup_ipv6_type,
  73         .size           = NFT_EXPR_SIZE(sizeof(struct nft_dup_ipv6)),
  74         .eval           = nft_dup_ipv6_eval,
  75         .init           = nft_dup_ipv6_init,
  76         .dump           = nft_dup_ipv6_dump,
  77 };
  78
  79 static const struct nla_policy nft_dup_ipv6_policy[NFTA_DUP_MAX + 1] = {
  80         [NFTA_DUP_SREG_ADDR]    = { .type = NLA_U32 },
  81         [NFTA_DUP_SREG_DEV]     = { .type = NLA_U32 },
  82 };
  83
  84 static struct nft_expr_type nft_dup_ipv6_type __read_mostly = {
  85         .family         = NFPROTO_IPV6,
  86         .name           = "dup",
  87         .ops            = &nft_dup_ipv6_ops,
  88         .policy         = nft_dup_ipv6_policy,
  89         .maxattr        = NFTA_DUP_MAX,
  90         .owner          = THIS_MODULE,
  91 };
  92
  93 static int __init nft_dup_ipv6_module_init(void)
  94 {
  95         return nft_register_expr(&nft_dup_ipv6_type);
  96 }
  97
  98 static void __exit nft_dup_ipv6_module_exit(void)
  99 {
 100         nft_unregister_expr(&nft_dup_ipv6_type);
 101 }
 102
 103 module_init(nft_dup_ipv6_module_init);
 104 module_exit(nft_dup_ipv6_module_exit);
 105
 106 MODULE_LICENSE("GPL");
 107 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
 108 MODULE_ALIAS_NFT_AF_EXPR(AF_INET6, "dup");