/*
   * 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.
   *
   *		Definitions for the protocol dispatcher.
   *
   * Version:	@(#)protocol.h	1.0.2	05/07/93
   *
   * Author:	Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
   *
   *		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:
   *		Alan Cox	:	Added a name field and a frag handler
   *					field for later.
   *		Alan Cox	:	Cleaned up, and sorted types.
   *		Pedro Roque	:	inet6 protocols
   */
   
  #ifndef _PROTOCOL_H
  #define _PROTOCOL_H

  #include <linux/in6.h>

  #include <linux/skbuff.h>

  #if IS_ENABLED(CONFIG_IPV6)

  #include <linux/ipv6.h>
  #endif

  #include <linux/netdevice.h>

  /* This is one larger than the largest protocol value that can be
   * found in an ipv4 or ipv6 header.  Since in both cases the protocol
   * value is presented in a __u8, this is defined to be 256.
   */
  #define MAX_INET_PROTOS		256

  
  /* This is used to register protocols. */
  struct net_protocol {

  	int			(*early_demux)(struct sk_buff *skb);
  	int			(*early_demux_handler)(struct sk_buff *skb);

  	int			(*handler)(struct sk_buff *skb);
  	void			(*err_handler)(struct sk_buff *skb, u32 info);

  	unsigned int		no_policy:1,

  				netns_ok:1,
  				/* does the protocol do more stringent
  				 * icmp tag validation than simple
  				 * socket lookup?
  				 */
  				icmp_strict_tag_validation:1;

  };

  #if IS_ENABLED(CONFIG_IPV6)

  struct inet6_protocol {

  	void	(*early_demux)(struct sk_buff *skb);

  	void    (*early_demux_handler)(struct sk_buff *skb);

  	int	(*handler)(struct sk_buff *skb);

  
  	void	(*err_handler)(struct sk_buff *skb,
  			       struct inet6_skb_parm *opt,

  			       u8 type, u8 code, int offset,

  			       __be32 info);

  	unsigned int	flags;	/* INET6_PROTO_xxx */
  };
  
  #define INET6_PROTO_NOPOLICY	0x1
  #define INET6_PROTO_FINAL	0x2
  #endif

  struct net_offload {

  	struct offload_callbacks callbacks;
  	unsigned int		 flags;	/* Flags used by IPv6 for now */

  };

  /* This should be set for any extension header which is compatible with GSO. */
  #define INET6_PROTO_GSO_EXTHDR	0x1

  /* This is used to register socket interfaces for IP protocols.  */
  struct inet_protosw {
  	struct list_head list;
  
          /* These two fields form the lookup key.  */
  	unsigned short	 type;	   /* This is the 2nd argument to socket(2). */

  	unsigned short	 protocol; /* This is the L4 protocol number.  */

  
  	struct proto	 *prot;

  	const struct proto_ops *ops;

  	unsigned char	 flags;      /* See INET_PROTOSW_* below.  */
  };
  #define INET_PROTOSW_REUSE 0x01	     /* Are ports automatically reusable? */
  #define INET_PROTOSW_PERMANENT 0x02  /* Permanent protocols are unremovable. */

  #define INET_PROTOSW_ICSK      0x04  /* Is this an inet_connection_sock? */

  extern struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS];

  extern const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS];

  extern const struct net_offload __rcu *inet6_offloads[MAX_INET_PROTOS];

  #if IS_ENABLED(CONFIG_IPV6)

  extern struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS];

  #endif

  int inet_add_protocol(const struct net_protocol *prot, unsigned char num);
  int inet_del_protocol(const struct net_protocol *prot, unsigned char num);
  int inet_add_offload(const struct net_offload *prot, unsigned char num);
  int inet_del_offload(const struct net_offload *prot, unsigned char num);
  void inet_register_protosw(struct inet_protosw *p);
  void inet_unregister_protosw(struct inet_protosw *p);

  #if IS_ENABLED(CONFIG_IPV6)

  int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char num);
  int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char num);
  int inet6_register_protosw(struct inet_protosw *p);
  void inet6_unregister_protosw(struct inet_protosw *p);

  #endif

  int inet6_add_offload(const struct net_offload *prot, unsigned char num);
  int inet6_del_offload(const struct net_offload *prot, unsigned char num);

  
  #endif	/* _PROTOCOL_H */