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

  /*
   * Copyright (c) 2006 Patrick McHardy <kaber@trash.net>

   */
  
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/skbuff.h>
  
  #include <linux/netfilter/x_tables.h>
  #include <linux/netfilter/xt_NFLOG.h>

  #include <net/netfilter/nf_log.h>

  
  MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");

  MODULE_DESCRIPTION("Xtables: packet logging to netlink using NFLOG");

  MODULE_LICENSE("GPL");
  MODULE_ALIAS("ipt_NFLOG");
  MODULE_ALIAS("ip6t_NFLOG");
  
  static unsigned int

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

  {

  	const struct xt_nflog_info *info = par->targinfo;

  	struct net *net = xt_net(par);

  	struct nf_loginfo li;
  
  	li.type		     = NF_LOG_TYPE_ULOG;
  	li.u.ulog.copy_len   = info->len;
  	li.u.ulog.group	     = info->group;
  	li.u.ulog.qthreshold = info->threshold;

  	li.u.ulog.flags	     = 0;

  	if (info->flags & XT_NFLOG_F_COPY_LEN)
  		li.u.ulog.flags |= NF_LOG_F_COPY_LEN;

  	nf_log_packet(net, xt_family(par), xt_hooknum(par), skb, xt_in(par),
  		      xt_out(par), &li, "%s", info->prefix);

  	return XT_CONTINUE;
  }

  static int nflog_tg_check(const struct xt_tgchk_param *par)

  {

  	const struct xt_nflog_info *info = par->targinfo;

  
  	if (info->flags & ~XT_NFLOG_MASK)

  		return -EINVAL;

  	if (info->prefix[sizeof(info->prefix) - 1] != '\0')

  		return -EINVAL;

  
  	return nf_logger_find_get(par->family, NF_LOG_TYPE_ULOG);
  }
  
  static void nflog_tg_destroy(const struct xt_tgdtor_param *par)
  {
  	nf_logger_put(par->family, NF_LOG_TYPE_ULOG);

  }

  static struct xt_target nflog_tg_reg __read_mostly = {
  	.name       = "NFLOG",
  	.revision   = 0,
  	.family     = NFPROTO_UNSPEC,
  	.checkentry = nflog_tg_check,

  	.destroy    = nflog_tg_destroy,

  	.target     = nflog_tg,
  	.targetsize = sizeof(struct xt_nflog_info),
  	.me         = THIS_MODULE,

  };

  static int __init nflog_tg_init(void)

  {

  	return xt_register_target(&nflog_tg_reg);

  }

  static void __exit nflog_tg_exit(void)

  {

  	xt_unregister_target(&nflog_tg_reg);

  }

  module_init(nflog_tg_init);
  module_exit(nflog_tg_exit);