LXR linux/net/ipv4/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/ipv4/nf_dup_ipv4.h>
  14
  15struct nft_dup_ipv4 {
  16        enum nft_registers      sreg_addr:8;
  17        enum nft_registers      sreg_dev:8;
  18};
  19
  20static void nft_dup_ipv4_eval(const struct nft_expr *expr,
  21                              struct nft_regs *regs,
  22                              const struct nft_pktinfo *pkt)
  23{
  24        struct nft_dup_ipv4 *priv = nft_expr_priv(expr);
  25        struct in_addr gw = {
  26                .s_addr = (__force __be32)regs->data[priv->sreg_addr],
  27        };
  28        int oif = priv->sreg_dev ? regs->data[priv->sreg_dev] : -1;
  29
  30        nf_dup_ipv4(nft_net(pkt), pkt->skb, nft_hook(pkt), &gw, oif);
  31}
  32
  33static int nft_dup_ipv4_init(const struct nft_ctx *ctx,
  34                             const struct nft_expr *expr,
  35                             const struct nlattr * const tb[])
  36{
  37        struct nft_dup_ipv4 *priv = nft_expr_priv(expr);
  38        int err;
  39
  40        if (tb[NFTA_DUP_SREG_ADDR] == NULL)
  41                return -EINVAL;
  42
  43        priv->sreg_addr = nft_parse_register(tb[NFTA_DUP_SREG_ADDR]);
  44        err = nft_validate_register_load(priv->sreg_addr, sizeof(struct in_addr));
  45        if (err < 0)
  46                return err;
  47
  48        if (tb[NFTA_DUP_SREG_DEV] != NULL) {
  49                priv->sreg_dev = nft_parse_register(tb[NFTA_DUP_SREG_DEV]);
  50                return nft_validate_register_load(priv->sreg_dev, sizeof(int));
  51        }
  52        return 0;
  53}
  54
  55static int nft_dup_ipv4_dump(struct sk_buff *skb, const struct nft_expr *expr)
  56{
  57        struct nft_dup_ipv4 *priv = nft_expr_priv(expr);
  58
  59        if (nft_dump_register(skb, NFTA_DUP_SREG_ADDR, priv->sreg_addr))
  60                goto nla_put_failure;
  61        if (priv->sreg_dev &&
  62            nft_dump_register(skb, NFTA_DUP_SREG_DEV, priv->sreg_dev))
  63                goto nla_put_failure;
  64
  65        return 0;
  66
  67nla_put_failure:
  68        return -1;
  69}
  70
  71static struct nft_expr_type nft_dup_ipv4_type;
  72static const struct nft_expr_ops nft_dup_ipv4_ops = {
  73        .type           = &nft_dup_ipv4_type,
  74        .size           = NFT_EXPR_SIZE(sizeof(struct nft_dup_ipv4)),
  75        .eval           = nft_dup_ipv4_eval,
  76        .init           = nft_dup_ipv4_init,
  77        .dump           = nft_dup_ipv4_dump,
  78};
  79
  80static const struct nla_policy nft_dup_ipv4_policy[NFTA_DUP_MAX + 1] = {
  81        [NFTA_DUP_SREG_ADDR]    = { .type = NLA_U32 },
  82        [NFTA_DUP_SREG_DEV]     = { .type = NLA_U32 },
  83};
  84
  85static struct nft_expr_type nft_dup_ipv4_type __read_mostly = {
  86        .family         = NFPROTO_IPV4,
  87        .name           = "dup",
  88        .ops            = &nft_dup_ipv4_ops,
  89        .policy         = nft_dup_ipv4_policy,
  90        .maxattr        = NFTA_DUP_MAX,
  91        .owner          = THIS_MODULE,
  92};
  93
  94static int __init nft_dup_ipv4_module_init(void)
  95{
  96        return nft_register_expr(&nft_dup_ipv4_type);
  97}
  98
  99static void __exit nft_dup_ipv4_module_exit(void)
 100{
 101        nft_unregister_expr(&nft_dup_ipv4_type);
 102}
 103
 104module_init(nft_dup_ipv4_module_init);
 105module_exit(nft_dup_ipv4_module_exit);
 106
 107MODULE_LICENSE("GPL");
 108MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
 109MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "dup");
 110MODULE_DESCRIPTION("IPv4 nftables packet duplication support");
 111