/*
   * INET		An implementation of the TCP/IP protocol suite for the LINUX
   *		operating system.  INET is implemented using the  BSD Socket
   *		interface as the means of communication with the user level.
   *
   *		PF_INET6 protocol dispatch tables.
   *
   * Authors:	Pedro Roque	<roque@di.fc.ul.pt>
   *
   *		This program is free software; you can redistribute it and/or
   *		modify it under the terms of the GNU General Public License
   *		as published by the Free Software Foundation; either version
   *		2 of the License, or (at your option) any later version.
   */
  
  /*
   *      Changes:
   *
   *      Vince Laviano (vince@cs.stanford.edu)       16 May 2001
   *      - Removed unused variable 'inet6_protocol_base'
   *      - Modified inet6_del_protocol() to correctly maintain copy bit.
   */
  #include <linux/module.h>
  #include <linux/netdevice.h>
  #include <linux/spinlock.h>
  #include <net/protocol.h>
  
  #if IS_ENABLED(CONFIG_IPV6)
  const struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS] __read_mostly;
  EXPORT_SYMBOL(inet6_protos);
  
  int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char protocol)
  {
  	return !cmpxchg((const struct inet6_protocol **)&inet6_protos[protocol],
  			NULL, prot) ? 0 : -1;
  }
  EXPORT_SYMBOL(inet6_add_protocol);
  
  int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char protocol)
  {
  	int ret;
  
  	ret = (cmpxchg((const struct inet6_protocol **)&inet6_protos[protocol],
  		       prot, NULL) == prot) ? 0 : -1;
  
  	synchronize_net();
  
  	return ret;
  }
  EXPORT_SYMBOL(inet6_del_protocol);
  #endif
  
  const struct net_offload __rcu *inet6_offloads[MAX_INET_PROTOS] __read_mostly;
  
  int inet6_add_offload(const struct net_offload *prot, unsigned char protocol)
  {
  	return !cmpxchg((const struct net_offload **)&inet6_offloads[protocol],
  			NULL, prot) ? 0 : -1;
  }
  EXPORT_SYMBOL(inet6_add_offload);
  
  int inet6_del_offload(const struct net_offload *prot, unsigned char protocol)
  {
  	int ret;
  
  	ret = (cmpxchg((const struct net_offload **)&inet6_offloads[protocol],
  		       prot, NULL) == prot) ? 0 : -1;
  
  	synchronize_net();
  
  	return ret;
  }
  EXPORT_SYMBOL(inet6_del_offload);