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

  /* This is a module which is used to mark packets for tracing.
   */
  #include <linux/module.h>
  #include <linux/skbuff.h>
  
  #include <linux/netfilter/x_tables.h>

  #include <net/netfilter/nf_log.h>

  MODULE_DESCRIPTION("Xtables: packet flow tracing");

  MODULE_LICENSE("GPL");
  MODULE_ALIAS("ipt_TRACE");
  MODULE_ALIAS("ip6t_TRACE");

  static int trace_tg_check(const struct xt_tgchk_param *par)
  {
  	return nf_logger_find_get(par->family, NF_LOG_TYPE_LOG);
  }
  
  static void trace_tg_destroy(const struct xt_tgdtor_param *par)
  {
  	nf_logger_put(par->family, NF_LOG_TYPE_LOG);
  }

  static unsigned int

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

  {

  	skb->nf_trace = 1;

  	return XT_CONTINUE;
  }

  static struct xt_target trace_tg_reg __read_mostly = {

  	.name		= "TRACE",
  	.revision	= 0,
  	.family		= NFPROTO_UNSPEC,
  	.table		= "raw",
  	.target		= trace_tg,
  	.checkentry	= trace_tg_check,
  	.destroy	= trace_tg_destroy,
  	.me		= THIS_MODULE,

  };

  static int __init trace_tg_init(void)

  {

  	return xt_register_target(&trace_tg_reg);

  }

  static void __exit trace_tg_exit(void)

  {

  	xt_unregister_target(&trace_tg_reg);

  }

  module_init(trace_tg_init);
  module_exit(trace_tg_exit);