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 #if IS_ENABLED(CONFIG_IPV6)
  29 #include <linux/ipv6.h>
  30 #endif
  31
  32 /* This is one larger than the largest protocol value that can be
  33  * found in an ipv4 or ipv6 header.  Since in both cases the protocol
  34  * value is presented in a __u8, this is defined to be 256.
  35  */
  36 #define MAX_INET_PROTOS         256
  37
  38 /* This is used to register protocols. */
  39 struct net_protocol {
  40         void                    (*early_demux)(struct sk_buff *skb);
  41         int                     (*handler)(struct sk_buff *skb);
  42         void                    (*err_handler)(struct sk_buff *skb, u32 info);
  43         int                     (*gso_send_check)(struct sk_buff *skb);
  44         struct sk_buff         *(*gso_segment)(struct sk_buff *skb,
  45                                                netdev_features_t features);
  46         struct sk_buff        **(*gro_receive)(struct sk_buff **head,
  47                                                struct sk_buff *skb);
  48         int                     (*gro_complete)(struct sk_buff *skb);
  49         unsigned int            no_policy:1,
  50                                 netns_ok:1;
  51 };
  52
  53 #if IS_ENABLED(CONFIG_IPV6)
  54 struct inet6_protocol {
  55         void    (*early_demux)(struct sk_buff *skb);
  56
  57         int     (*handler)(struct sk_buff *skb);
  58
  59         void    (*err_handler)(struct sk_buff *skb,
  60                                struct inet6_skb_parm *opt,
  61                                u8 type, u8 code, int offset,
  62                                __be32 info);
  63
  64         int     (*gso_send_check)(struct sk_buff *skb);
  65         struct sk_buff *(*gso_segment)(struct sk_buff *skb,
  66                                        netdev_features_t features);
  67         struct sk_buff **(*gro_receive)(struct sk_buff **head,
  68                                         struct sk_buff *skb);
  69         int     (*gro_complete)(struct sk_buff *skb);
  70
  71         unsigned int    flags;  /* INET6_PROTO_xxx */
  72 };
  73
  74 #define INET6_PROTO_NOPOLICY    0x1
  75 #define INET6_PROTO_FINAL       0x2
  76 /* This should be set for any extension header which is compatible with GSO. */
  77 #define INET6_PROTO_GSO_EXTHDR  0x4
  78 #endif
  79
  80 struct net_offload {
  81         int                     (*gso_send_check)(struct sk_buff *skb);
  82         struct sk_buff         *(*gso_segment)(struct sk_buff *skb,
  83                                                netdev_features_t features);
  84         struct sk_buff        **(*gro_receive)(struct sk_buff **head,
  85                                                struct sk_buff *skb);
  86         int                     (*gro_complete)(struct sk_buff *skb);
  87 };
  88
  89 /* This is used to register socket interfaces for IP protocols.  */
  90 struct inet_protosw {
  91         struct list_head list;
  92
  93         /* These two fields form the lookup key.  */
  94         unsigned short   type;     /* This is the 2nd argument to socket(2). */
  95         unsigned short   protocol; /* This is the L4 protocol number.  */
  96
  97         struct proto     *prot;
  98         const struct proto_ops *ops;
  99
 100         char             no_check;   /* checksum on rcv/xmit/none? */
 101         unsigned char    flags;      /* See INET_PROTOSW_* below.  */
 102 };
 103 #define INET_PROTOSW_REUSE 0x01      /* Are ports automatically reusable? */
 104 #define INET_PROTOSW_PERMANENT 0x02  /* Permanent protocols are unremovable. */
 105 #define INET_PROTOSW_ICSK      0x04  /* Is this an inet_connection_sock? */
 106
 107 extern const struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS];
 108 extern const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS];
 109
 110 #if IS_ENABLED(CONFIG_IPV6)
 111 extern const struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS];
 112 #endif
 113
 114 extern int      inet_add_protocol(const struct net_protocol *prot, unsigned char num);
 115 extern int      inet_del_protocol(const struct net_protocol *prot, unsigned char num);
 116 extern int      inet_add_offload(const struct net_offload *prot, unsigned char num);
 117 extern int      inet_del_offload(const struct net_offload *prot, unsigned char num);
 118 extern void     inet_register_protosw(struct inet_protosw *p);
 119 extern void     inet_unregister_protosw(struct inet_protosw *p);
 120
 121 #if IS_ENABLED(CONFIG_IPV6)
 122 extern int      inet6_add_protocol(const struct inet6_protocol *prot, unsigned char num);
 123 extern int      inet6_del_protocol(const struct inet6_protocol *prot, unsigned char num);
 124 extern int      inet6_register_protosw(struct inet_protosw *p);
 125 extern void     inet6_unregister_protosw(struct inet_protosw *p);
 126 #endif
 127
 128 #endif  /* _PROTOCOL_H */