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. */
  37 struct 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)
  55 struct 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
  73 struct 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.  */
  81 struct 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
  97 extern struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS];
  98 extern const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS];
  99 extern const struct net_offload __rcu *inet6_offloads[MAX_INET_PROTOS];
 100
 101 #if IS_ENABLED(CONFIG_IPV6)
 102 extern struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS];
 103 #endif
 104
 105 int inet_add_protocol(const struct net_protocol *prot, unsigned char num);
 106 int inet_del_protocol(const struct net_protocol *prot, unsigned char num);
 107 int inet_add_offload(const struct net_offload *prot, unsigned char num);
 108 int inet_del_offload(const struct net_offload *prot, unsigned char num);
 109 void inet_register_protosw(struct inet_protosw *p);
 110 void inet_unregister_protosw(struct inet_protosw *p);
 111
 112 #if IS_ENABLED(CONFIG_IPV6)
 113 int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char num);
 114 int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char num);
 115 int inet6_register_protosw(struct inet_protosw *p);
 116 void inet6_unregister_protosw(struct inet_protosw *p);
 117 #endif
 118 int inet6_add_offload(const struct net_offload *prot, unsigned char num);
 119 int inet6_del_offload(const struct net_offload *prot, unsigned char num);
 120
 121 #endif  /* _PROTOCOL_H */