/*
* 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, <[email protected]>
*
* 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 {
void (*early_demux)(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;
};

#if IS_ENABLED(CONFIG_IPV6)
struct inet6_protocol {
void (*early_demux)(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;

char no_check; /* checksum on rcv/xmit/none? */
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 const 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 const 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);

int udp_add_offload(struct udp_offload *prot);
void udp_del_offload(struct udp_offload *prot);

#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 */