net/netfilter/nft_dup_netdev.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/nf_dup_netdev.h>
  17
  18 struct nft_dup_netdev {
  19         enum nft_registers      sreg_dev:8;
  20 };
  21
  22 static void nft_dup_netdev_eval(const struct nft_expr *expr,
  23                                 struct nft_regs *regs,
  24                                 const struct nft_pktinfo *pkt)
  25 {
  26         struct nft_dup_netdev *priv = nft_expr_priv(expr);
  27         int oif = regs->data[priv->sreg_dev];
  28
  29         nf_dup_netdev_egress(pkt, oif);
  30 }
  31
  32 static const struct nla_policy nft_dup_netdev_policy[NFTA_DUP_MAX + 1] = {
  33         [NFTA_DUP_SREG_DEV]     = { .type = NLA_U32 },
  34 };
  35
  36 static int nft_dup_netdev_init(const struct nft_ctx *ctx,
  37                                const struct nft_expr *expr,
  38                                const struct nlattr * const tb[])
  39 {
  40         struct nft_dup_netdev *priv = nft_expr_priv(expr);
  41
  42         if (tb[NFTA_DUP_SREG_DEV] == NULL)
  43                 return -EINVAL;
  44
  45         priv->sreg_dev = nft_parse_register(tb[NFTA_DUP_SREG_DEV]);
  46         return nft_validate_register_load(priv->sreg_dev, sizeof(int));
  47 }
  48
  49 static const struct nft_expr_ops nft_dup_netdev_ingress_ops;
  50
  51 static int nft_dup_netdev_dump(struct sk_buff *skb, const struct nft_expr *expr)
  52 {
  53         struct nft_dup_netdev *priv = nft_expr_priv(expr);
  54
  55         if (nft_dump_register(skb, NFTA_DUP_SREG_DEV, priv->sreg_dev))
  56                 goto nla_put_failure;
  57
  58         return 0;
  59
  60 nla_put_failure:
  61         return -1;
  62 }
  63
  64 static struct nft_expr_type nft_dup_netdev_type;
  65 static const struct nft_expr_ops nft_dup_netdev_ops = {
  66         .type           = &nft_dup_netdev_type,
  67         .size           = NFT_EXPR_SIZE(sizeof(struct nft_dup_netdev)),
  68         .eval           = nft_dup_netdev_eval,
  69         .init           = nft_dup_netdev_init,
  70         .dump           = nft_dup_netdev_dump,
  71 };
  72
  73 static struct nft_expr_type nft_dup_netdev_type __read_mostly = {
  74         .family         = NFPROTO_NETDEV,
  75         .name           = "dup",
  76         .ops            = &nft_dup_netdev_ops,
  77         .policy         = nft_dup_netdev_policy,
  78         .maxattr        = NFTA_DUP_MAX,
  79         .owner          = THIS_MODULE,
  80 };
  81
  82 static int __init nft_dup_netdev_module_init(void)
  83 {
  84         return nft_register_expr(&nft_dup_netdev_type);
  85 }
  86
  87 static void __exit nft_dup_netdev_module_exit(void)
  88 {
  89         nft_unregister_expr(&nft_dup_netdev_type);
  90 }
  91
  92 module_init(nft_dup_netdev_module_init);
  93 module_exit(nft_dup_netdev_module_exit);
  94
  95 MODULE_LICENSE("GPL");
  96 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
  97 MODULE_ALIAS_NFT_AF_EXPR(5, "dup");