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                     (*handler)(struct sk_buff *skb);
  39
  40         /* This returns an error if we weren't able to handle the error. */
  41         int                     (*err_handler)(struct sk_buff *skb, u32 info);
  42
  43         unsigned int            no_policy:1,
  44                                 /* does the protocol do more stringent
  45                                  * icmp tag validation than simple
  46                                  * socket lookup?
  47                                  */
  48                                 icmp_strict_tag_validation:1;
  49         u32                     secret;
  50 };
  51
  52 #if IS_ENABLED(CONFIG_IPV6)
  53 struct inet6_protocol {
  54         int     (*handler)(struct sk_buff *skb);
  55
  56         /* This returns an error if we weren't able to handle the error. */
  57         int     (*err_handler)(struct sk_buff *skb,
  58                                struct inet6_skb_parm *opt,
  59                                u8 type, u8 code, int offset,
  60                                __be32 info);
  61
  62         unsigned int    flags;  /* INET6_PROTO_xxx */
  63         u32             secret;
  64 };
  65
  66 #define INET6_PROTO_NOPOLICY    0x1
  67 #define INET6_PROTO_FINAL       0x2
  68 #endif
  69
  70 struct net_offload {
  71         struct offload_callbacks callbacks;
  72         unsigned int             flags; /* Flags used by IPv6 for now */
  73         u32                      secret;
  74 };
  75 /* This should be set for any extension header which is compatible with GSO. */
  76 #define INET6_PROTO_GSO_EXTHDR  0x1
  77
  78 /* This is used to register socket interfaces for IP protocols.  */
  79 struct inet_protosw {
  80         struct list_head list;
  81
  82         /* These two fields form the lookup key.  */
  83         unsigned short   type;     /* This is the 2nd argument to socket(2). */
  84         unsigned short   protocol; /* This is the L4 protocol number.  */
  85
  86         struct proto     *prot;
  87         const struct proto_ops *ops;
  88
  89         unsigned char    flags;      /* See INET_PROTOSW_* below.  */
  90 };
  91 #define INET_PROTOSW_REUSE 0x01      /* Are ports automatically reusable? */
  92 #define INET_PROTOSW_PERMANENT 0x02  /* Permanent protocols are unremovable. */
  93 #define INET_PROTOSW_ICSK      0x04  /* Is this an inet_connection_sock? */
  94
  95 extern struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS];
  96 extern const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS];
  97 extern const struct net_offload __rcu *inet6_offloads[MAX_INET_PROTOS];
  98
  99 #if IS_ENABLED(CONFIG_IPV6)
 100 extern struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS];
 101 #endif
 102
 103 int inet_add_protocol(const struct net_protocol *prot, unsigned char num);
 104 int inet_del_protocol(const struct net_protocol *prot, unsigned char num);
 105 int inet_add_offload(const struct net_offload *prot, unsigned char num);
 106 int inet_del_offload(const struct net_offload *prot, unsigned char num);
 107 void inet_register_protosw(struct inet_protosw *p);
 108 void inet_unregister_protosw(struct inet_protosw *p);
 109
 110 #if IS_ENABLED(CONFIG_IPV6)
 111 int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char num);
 112 int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char num);
 113 int inet6_register_protosw(struct inet_protosw *p);
 114 void inet6_unregister_protosw(struct inet_protosw *p);
 115 #endif
 116 int inet6_add_offload(const struct net_offload *prot, unsigned char num);
 117 int inet6_del_offload(const struct net_offload *prot, unsigned char num);
 118
 119 #endif  /* _PROTOCOL_H */