// SPDX-License-Identifier: GPL-2.0-only

  /* (C) 1999-2001 Michal Ludvig <michal@logix.cz>

   */
  
  #include <linux/module.h>
  #include <linux/skbuff.h>
  #include <linux/if_ether.h>
  #include <linux/if_packet.h>

  #include <linux/in.h>
  #include <linux/ip.h>

  #include <linux/ipv6.h>

  #include <linux/netfilter/xt_pkttype.h>
  #include <linux/netfilter/x_tables.h>

  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Michal Ludvig <michal@logix.cz>");

  MODULE_DESCRIPTION("Xtables: link layer packet type match");

  MODULE_ALIAS("ipt_pkttype");
  MODULE_ALIAS("ip6t_pkttype");

  static bool

  pkttype_mt(const struct sk_buff *skb, struct xt_action_param *par)

  {

  	const struct xt_pkttype_info *info = par->matchinfo;

  	u_int8_t type;

  	if (skb->pkt_type != PACKET_LOOPBACK)

  		type = skb->pkt_type;

  	else if (xt_family(par) == NFPROTO_IPV4 &&

  	    ipv4_is_multicast(ip_hdr(skb)->daddr))
  		type = PACKET_MULTICAST;

  	else if (xt_family(par) == NFPROTO_IPV6)

  		type = PACKET_MULTICAST;
  	else
  		type = PACKET_BROADCAST;

  
  	return (type == info->pkttype) ^ info->invert;

  }

  static struct xt_match pkttype_mt_reg __read_mostly = {
  	.name      = "pkttype",
  	.revision  = 0,
  	.family    = NFPROTO_UNSPEC,
  	.match     = pkttype_mt,
  	.matchsize = sizeof(struct xt_pkttype_info),
  	.me        = THIS_MODULE,

  };

  static int __init pkttype_mt_init(void)

  {

  	return xt_register_match(&pkttype_mt_reg);

  }

  static void __exit pkttype_mt_exit(void)

  {

  	xt_unregister_match(&pkttype_mt_reg);

  }

  module_init(pkttype_mt_init);
  module_exit(pkttype_mt_exit);