LXR linux/net/netfilter/nft_dup

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org>
   4 */
   5
   6#include <linux/kernel.h>
   7#include <linux/init.h>
   8#include <linux/module.h>
   9#include <linux/netlink.h>
  10#include <linux/netfilter.h>
  11#include <linux/netfilter/nf_tables.h>
  12#include <net/netfilter/nf_tables.h>
  13#include <net/netfilter/nf_tables_offload.h>
  14#include <net/netfilter/nf_dup_netdev.h>
  15
  16struct nft_dup_netdev {
  17        u8      sreg_dev;
  18};
  19
  20static void nft_dup_netdev_eval(const struct nft_expr *expr,
  21                                struct nft_regs *regs,
  22                                const struct nft_pktinfo *pkt)
  23{
  24        struct nft_dup_netdev *priv = nft_expr_priv(expr);
  25        int oif = regs->data[priv->sreg_dev];
  26
  27        nf_dup_netdev_egress(pkt, oif);
  28}
  29
  30static const struct nla_policy nft_dup_netdev_policy[NFTA_DUP_MAX + 1] = {
  31        [NFTA_DUP_SREG_DEV]     = { .type = NLA_U32 },
  32};
  33
  34static int nft_dup_netdev_init(const struct nft_ctx *ctx,
  35                               const struct nft_expr *expr,
  36                               const struct nlattr * const tb[])
  37{
  38        struct nft_dup_netdev *priv = nft_expr_priv(expr);
  39
  40        if (tb[NFTA_DUP_SREG_DEV] == NULL)
  41                return -EINVAL;
  42
  43        return nft_parse_register_load(tb[NFTA_DUP_SREG_DEV], &priv->sreg_dev,
  44                                       sizeof(int));
  45}
  46
  47static int nft_dup_netdev_dump(struct sk_buff *skb, const struct nft_expr *expr)
  48{
  49        struct nft_dup_netdev *priv = nft_expr_priv(expr);
  50
  51        if (nft_dump_register(skb, NFTA_DUP_SREG_DEV, priv->sreg_dev))
  52                goto nla_put_failure;
  53
  54        return 0;
  55
  56nla_put_failure:
  57        return -1;
  58}
  59
  60static int nft_dup_netdev_offload(struct nft_offload_ctx *ctx,
  61                                  struct nft_flow_rule *flow,
  62                                  const struct nft_expr *expr)
  63{
  64        const struct nft_dup_netdev *priv = nft_expr_priv(expr);
  65        int oif = ctx->regs[priv->sreg_dev].data.data[0];
  66
  67        return nft_fwd_dup_netdev_offload(ctx, flow, FLOW_ACTION_MIRRED, oif);
  68}
  69
  70static bool nft_dup_netdev_offload_action(const struct nft_expr *expr)
  71{
  72        return true;
  73}
  74
  75static struct nft_expr_type nft_dup_netdev_type;
  76static const struct nft_expr_ops nft_dup_netdev_ops = {
  77        .type           = &nft_dup_netdev_type,
  78        .size           = NFT_EXPR_SIZE(sizeof(struct nft_dup_netdev)),
  79        .eval           = nft_dup_netdev_eval,
  80        .init           = nft_dup_netdev_init,
  81        .dump           = nft_dup_netdev_dump,
  82        .reduce         = NFT_REDUCE_READONLY,
  83        .offload        = nft_dup_netdev_offload,
  84        .offload_action = nft_dup_netdev_offload_action,
  85};
  86
  87static struct nft_expr_type nft_dup_netdev_type __read_mostly = {
  88        .family         = NFPROTO_NETDEV,
  89        .name           = "dup",
  90        .ops            = &nft_dup_netdev_ops,
  91        .policy         = nft_dup_netdev_policy,
  92        .maxattr        = NFTA_DUP_MAX,
  93        .owner          = THIS_MODULE,
  94};
  95
  96static int __init nft_dup_netdev_module_init(void)
  97{
  98        return nft_register_expr(&nft_dup_netdev_type);
  99}
 100
 101static void __exit nft_dup_netdev_module_exit(void)
 102{
 103        nft_unregister_expr(&nft_dup_netdev_type);
 104}
 105
 106module_init(nft_dup_netdev_module_init);
 107module_exit(nft_dup_netdev_module_exit);
 108
 109MODULE_LICENSE("GPL");
 110MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
 111MODULE_ALIAS_NFT_AF_EXPR(5, "dup");
 112MODULE_DESCRIPTION("nftables netdev packet duplication support");
 113