net/netfilter/nft_fib_netdev.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2017 Pablo M. Bermudo Garay <pablombg@gmail.com>
   4  *
   5  * This code is based on net/netfilter/nft_fib_inet.c, written by
   6  * Florian Westphal <fw@strlen.de>.
   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_core.h>
  16 #include <net/netfilter/nf_tables.h>
  17 #include <net/ipv6.h>
  18
  19 #include <net/netfilter/nft_fib.h>
  20
  21 static void nft_fib_netdev_eval(const struct nft_expr *expr,
  22                                 struct nft_regs *regs,
  23                                 const struct nft_pktinfo *pkt)
  24 {
  25         const struct nft_fib *priv = nft_expr_priv(expr);
  26
  27         switch (ntohs(pkt->skb->protocol)) {
  28         case ETH_P_IP:
  29                 switch (priv->result) {
  30                 case NFT_FIB_RESULT_OIF:
  31                 case NFT_FIB_RESULT_OIFNAME:
  32                         return nft_fib4_eval(expr, regs, pkt);
  33                 case NFT_FIB_RESULT_ADDRTYPE:
  34                         return nft_fib4_eval_type(expr, regs, pkt);
  35                 }
  36                 break;
  37         case ETH_P_IPV6:
  38                 if (!ipv6_mod_enabled())
  39                         break;
  40                 switch (priv->result) {
  41                 case NFT_FIB_RESULT_OIF:
  42                 case NFT_FIB_RESULT_OIFNAME:
  43                         return nft_fib6_eval(expr, regs, pkt);
  44                 case NFT_FIB_RESULT_ADDRTYPE:
  45                         return nft_fib6_eval_type(expr, regs, pkt);
  46                 }
  47                 break;
  48         }
  49
  50         regs->verdict.code = NFT_BREAK;
  51 }
  52
  53 static struct nft_expr_type nft_fib_netdev_type;
  54 static const struct nft_expr_ops nft_fib_netdev_ops = {
  55         .type           = &nft_fib_netdev_type,
  56         .size           = NFT_EXPR_SIZE(sizeof(struct nft_fib)),
  57         .eval           = nft_fib_netdev_eval,
  58         .init           = nft_fib_init,
  59         .dump           = nft_fib_dump,
  60         .validate       = nft_fib_validate,
  61         .reduce         = nft_fib_reduce,
  62 };
  63
  64 static struct nft_expr_type nft_fib_netdev_type __read_mostly = {
  65         .family         = NFPROTO_NETDEV,
  66         .name           = "fib",
  67         .ops            = &nft_fib_netdev_ops,
  68         .policy         = nft_fib_policy,
  69         .maxattr        = NFTA_FIB_MAX,
  70         .owner          = THIS_MODULE,
  71 };
  72
  73 static int __init nft_fib_netdev_module_init(void)
  74 {
  75         return nft_register_expr(&nft_fib_netdev_type);
  76 }
  77
  78 static void __exit nft_fib_netdev_module_exit(void)
  79 {
  80         nft_unregister_expr(&nft_fib_netdev_type);
  81 }
  82
  83 module_init(nft_fib_netdev_module_init);
  84 module_exit(nft_fib_netdev_module_exit);
  85
  86 MODULE_LICENSE("GPL");
  87 MODULE_AUTHOR("Pablo M. Bermudo Garay <pablombg@gmail.com>");
  88 MODULE_ALIAS_NFT_AF_EXPR(5, "fib");
  89 MODULE_DESCRIPTION("nftables netdev fib lookups support");