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                                /* does the protocol do more stringent
  47                                 * icmp tag validation than simple
  48                                 * socket lookup?
  49                                 */
  50                                icmp_strict_tag_validation:1;
  51};
  52
  53#if IS_ENABLED(CONFIG_IPV6)
  54struct inet6_protocol {
  55        void    (*early_demux)(struct sk_buff *skb);
  56        void    (*early_demux_handler)(struct sk_buff *skb);
  57        int     (*handler)(struct sk_buff *skb);
  58
  59        /* This returns an error if we weren't able to handle the error. */
  60        int     (*err_handler)(struct sk_buff *skb,
  61                               struct inet6_skb_parm *opt,
  62                               u8 type, u8 code, int offset,
  63                               __be32 info);
  64
  65        unsigned int    flags;  /* INET6_PROTO_xxx */
  66};
  67
  68#define INET6_PROTO_NOPOLICY    0x1
  69#define INET6_PROTO_FINAL       0x2
  70#endif
  71
  72struct net_offload {
  73        struct offload_callbacks callbacks;
  74        unsigned int             flags; /* Flags used by IPv6 for now */
  75};
  76/* This should be set for any extension header which is compatible with GSO. */
  77#define INET6_PROTO_GSO_EXTHDR  0x1
  78
  79/* This is used to register socket interfaces for IP protocols.  */
  80struct inet_protosw {
  81        struct list_head list;
  82
  83        /* These two fields form the lookup key.  */
  84        unsigned short   type;     /* This is the 2nd argument to socket(2). */
  85        unsigned short   protocol; /* This is the L4 protocol number.  */
  86
  87        struct proto     *prot;
  88        const struct proto_ops *ops;
  89  
  90        unsigned char    flags;      /* See INET_PROTOSW_* below.  */
  91};
  92#define INET_PROTOSW_REUSE 0x01      /* Are ports automatically reusable? */
  93#define INET_PROTOSW_PERMANENT 0x02  /* Permanent protocols are unremovable. */
  94#define INET_PROTOSW_ICSK      0x04  /* Is this an inet_connection_sock? */
  95
  96extern struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS];
  97extern const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS];
  98extern const struct net_offload __rcu *inet6_offloads[MAX_INET_PROTOS];
  99
 100#if IS_ENABLED(CONFIG_IPV6)
 101extern struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS];
 102#endif
 103
 104int inet_add_protocol(const struct net_protocol *prot, unsigned char num);
 105int inet_del_protocol(const struct net_protocol *prot, unsigned char num);
 106int inet_add_offload(const struct net_offload *prot, unsigned char num);
 107int inet_del_offload(const struct net_offload *prot, unsigned char num);
 108void inet_register_protosw(struct inet_protosw *p);
 109void inet_unregister_protosw(struct inet_protosw *p);
 110
 111#if IS_ENABLED(CONFIG_IPV6)
 112int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char num);
 113int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char num);
 114int inet6_register_protosw(struct inet_protosw *p);
 115void inet6_unregister_protosw(struct inet_protosw *p);
 116#endif
 117int inet6_add_offload(const struct net_offload *prot, unsigned char num);
 118int inet6_del_offload(const struct net_offload *prot, unsigned char num);
 119
 120#endif  /* _PROTOCOL_H */
 121