include/net/protocol.h

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              Definitions for the protocol dispatcher.
   7  *
   8  * Version:     @(#)protocol.h  1.0.2   05/07/93
   9  *
  10  * Author:      Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  11  *
  12  *              This program is free software; you can redistribute it and/or
  13  *              modify it under the terms of the GNU General Public License
  14  *              as published by the Free Software Foundation; either version
  15  *              2 of the License, or (at your option) any later version.
  16  *
  17  *      Changes:
  18  *              Alan Cox        :       Added a name field and a frag handler
  19  *                                      field for later.
  20  *              Alan Cox        :       Cleaned up, and sorted types.
  21  *              Pedro Roque     :       inet6 protocols
  22  */
  23
  24 #ifndef _PROTOCOL_H
  25 #define _PROTOCOL_H
  26
  27 #include <linux/in6.h>
  28 #include <linux/skbuff.h>
  29 #if IS_ENABLED(CONFIG_IPV6)
  30 #include <linux/ipv6.h>
  31 #endif
  32 #include <linux/netdevice.h>
  33
  34 /* This is one larger than the largest protocol value that can be
  35  * found in an ipv4 or ipv6 header.  Since in both cases the protocol
  36  * value is presented in a __u8, this is defined to be 256.
  37  */
  38 #define MAX_INET_PROTOS         256
  39
  40 /* This is used to register protocols. */
  41 struct net_protocol {
  42         int                     (*early_demux)(struct sk_buff *skb);
  43         int                     (*early_demux_handler)(struct sk_buff *skb);
  44         int                     (*handler)(struct sk_buff *skb);
  45
  46         /* This returns an error if we weren't able to handle the error. */
  47         int                     (*err_handler)(struct sk_buff *skb, u32 info);
  48
  49         unsigned int            no_policy:1,
  50                                 netns_ok:1,
  51                                 /* does the protocol do more stringent
  52                                  * icmp tag validation than simple
  53                                  * socket lookup?
  54                                  */
  55                                 icmp_strict_tag_validation:1;
  56 };
  57
  58 #if IS_ENABLED(CONFIG_IPV6)
  59 struct inet6_protocol {
  60         void    (*early_demux)(struct sk_buff *skb);
  61         void    (*early_demux_handler)(struct sk_buff *skb);
  62         int     (*handler)(struct sk_buff *skb);
  63
  64         /* This returns an error if we weren't able to handle the error. */
  65         int     (*err_handler)(struct sk_buff *skb,
  66                                struct inet6_skb_parm *opt,
  67                                u8 type, u8 code, int offset,
  68                                __be32 info);
  69
  70         unsigned int    flags;  /* INET6_PROTO_xxx */
  71 };
  72
  73 #define INET6_PROTO_NOPOLICY    0x1
  74 #define INET6_PROTO_FINAL       0x2
  75 #endif
  76
  77 struct net_offload {
  78         struct offload_callbacks callbacks;
  79         unsigned int             flags; /* Flags used by IPv6 for now */
  80 };
  81 /* This should be set for any extension header which is compatible with GSO. */
  82 #define INET6_PROTO_GSO_EXTHDR  0x1
  83
  84 /* This is used to register socket interfaces for IP protocols.  */
  85 struct inet_protosw {
  86         struct list_head list;
  87
  88         /* These two fields form the lookup key.  */
  89         unsigned short   type;     /* This is the 2nd argument to socket(2). */
  90         unsigned short   protocol; /* This is the L4 protocol number.  */
  91
  92         struct proto     *prot;
  93         const struct proto_ops *ops;
  94
  95         unsigned char    flags;      /* See INET_PROTOSW_* below.  */
  96 };
  97 #define INET_PROTOSW_REUSE 0x01      /* Are ports automatically reusable? */
  98 #define INET_PROTOSW_PERMANENT 0x02  /* Permanent protocols are unremovable. */
  99 #define INET_PROTOSW_ICSK      0x04  /* Is this an inet_connection_sock? */
 100
 101 extern struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS];
 102 extern const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS];
 103 extern const struct net_offload __rcu *inet6_offloads[MAX_INET_PROTOS];
 104
 105 #if IS_ENABLED(CONFIG_IPV6)
 106 extern struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS];
 107 #endif
 108
 109 int inet_add_protocol(const struct net_protocol *prot, unsigned char num);
 110 int inet_del_protocol(const struct net_protocol *prot, unsigned char num);
 111 int inet_add_offload(const struct net_offload *prot, unsigned char num);
 112 int inet_del_offload(const struct net_offload *prot, unsigned char num);
 113 void inet_register_protosw(struct inet_protosw *p);
 114 void inet_unregister_protosw(struct inet_protosw *p);
 115
 116 #if IS_ENABLED(CONFIG_IPV6)
 117 int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char num);
 118 int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char num);
 119 int inet6_register_protosw(struct inet_protosw *p);
 120 void inet6_unregister_protosw(struct inet_protosw *p);
 121 #endif
 122 int inet6_add_offload(const struct net_offload *prot, unsigned char num);
 123 int inet6_del_offload(const struct net_offload *prot, unsigned char num);
 124
 125 #endif  /* _PROTOCOL_H */