LXR linux/include/net/protocol.h

   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/*
   3 * INET         An implementation of the TCP/IP protocol suite for the LINUX
   4 *              operating system.  INET is implemented using the  BSD Socket
   5 *              interface as the means of communication with the user level.
   6 *
   7 *              Definitions for the protocol dispatcher.
   8 *
   9 * Version:     @(#)protocol.h  1.0.2   05/07/93
  10 *
  11 * Author:      Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  12 *
  13 *      Changes:
  14 *              Alan Cox        :       Added a name field and a frag handler
  15 *                                      field for later.
  16 *              Alan Cox        :       Cleaned up, and sorted types.
  17 *              Pedro Roque     :       inet6 protocols
  18 */
  19 
  20#ifndef _PROTOCOL_H
  21#define _PROTOCOL_H
  22
  23#include <linux/in6.h>
  24#include <linux/skbuff.h>
  25#if IS_ENABLED(CONFIG_IPV6)
  26#include <linux/ipv6.h>
  27#endif
  28#include <linux/netdevice.h>
  29
  30/* This is one larger than the largest protocol value that can be
  31 * found in an ipv4 or ipv6 header.  Since in both cases the protocol
  32 * value is presented in a __u8, this is defined to be 256.
  33 */
  34#define MAX_INET_PROTOS         256
  35
  36/* This is used to register protocols. */
  37struct net_protocol {
  38        int                     (*early_demux)(struct sk_buff *skb);
  39        int                     (*early_demux_handler)(struct sk_buff *skb);
  40        int                     (*handler)(struct sk_buff *skb);
  41
  42        /* This returns an error if we weren't able to handle the error. */
  43        int                     (*err_handler)(struct sk_buff *skb, u32 info);
  44
  45        unsigned int            no_policy:1,
  46                                netns_ok:1,
  47                                /* does the protocol do more stringent
  48                                 * icmp tag validation than simple
  49                                 * socket lookup?
  50                                 */
  51                                icmp_strict_tag_validation:1;
  52};
  53
  54#if IS_ENABLED(CONFIG_IPV6)
  55struct inet6_protocol {
  56        void    (*early_demux)(struct sk_buff *skb);
  57        void    (*early_demux_handler)(struct sk_buff *skb);
  58        int     (*handler)(struct sk_buff *skb);
  59
  60        /* This returns an error if we weren't able to handle the error. */
  61        int     (*err_handler)(struct sk_buff *skb,
  62                               struct inet6_skb_parm *opt,
  63                               u8 type, u8 code, int offset,
  64                               __be32 info);
  65
  66        unsigned int    flags;  /* INET6_PROTO_xxx */
  67};
  68
  69#define INET6_PROTO_NOPOLICY    0x1
  70#define INET6_PROTO_FINAL       0x2
  71#endif
  72
  73struct net_offload {
  74        struct offload_callbacks callbacks;
  75        unsigned int             flags; /* Flags used by IPv6 for now */
  76};
  77/* This should be set for any extension header which is compatible with GSO. */
  78#define INET6_PROTO_GSO_EXTHDR  0x1
  79
  80/* This is used to register socket interfaces for IP protocols.  */
  81struct inet_protosw {
  82        struct list_head list;
  83
  84        /* These two fields form the lookup key.  */
  85        unsigned short   type;     /* This is the 2nd argument to socket(2). */
  86        unsigned short   protocol; /* This is the L4 protocol number.  */
  87
  88        struct proto     *prot;
  89        const struct proto_ops *ops;
  90  
  91        unsigned char    flags;      /* See INET_PROTOSW_* below.  */
  92};
  93#define INET_PROTOSW_REUSE 0x01      /* Are ports automatically reusable? */
  94#define INET_PROTOSW_PERMANENT 0x02  /* Permanent protocols are unremovable. */
  95#define INET_PROTOSW_ICSK      0x04  /* Is this an inet_connection_sock? */
  96
  97extern struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS];
  98extern const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS];
  99extern const struct net_offload __rcu *inet6_offloads[MAX_INET_PROTOS];
 100
 101#if IS_ENABLED(CONFIG_IPV6)
 102extern struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS];
 103#endif
 104
 105int inet_add_protocol(const struct net_protocol *prot, unsigned char num);
 106int inet_del_protocol(const struct net_protocol *prot, unsigned char num);
 107int inet_add_offload(const struct net_offload *prot, unsigned char num);
 108int inet_del_offload(const struct net_offload *prot, unsigned char num);
 109void inet_register_protosw(struct inet_protosw *p);
 110void inet_unregister_protosw(struct inet_protosw *p);
 111
 112#if IS_ENABLED(CONFIG_IPV6)
 113int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char num);
 114int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char num);
 115int inet6_register_protosw(struct inet_protosw *p);
 116void inet6_unregister_protosw(struct inet_protosw *p);
 117#endif
 118int inet6_add_offload(const struct net_offload *prot, unsigned char num);
 119int inet6_del_offload(const struct net_offload *prot, unsigned char num);
 120
 121#endif  /* _PROTOCOL_H */
 122