include/rxrpc/packet.h

   1 /* packet.h: Rx packet layout and definitions
   2  *
   3  * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #ifndef _LINUX_RXRPC_PACKET_H
  13 #define _LINUX_RXRPC_PACKET_H
  14
  15 #include <rxrpc/types.h>
  16
  17 #define RXRPC_IPUDP_SIZE                28
  18 extern size_t RXRPC_MAX_PACKET_SIZE;
  19 #define RXRPC_MAX_PACKET_DATA_SIZE      (RXRPC_MAX_PACKET_SIZE - sizeof(struct rxrpc_header))
  20 #define RXRPC_LOCAL_PACKET_SIZE         RXRPC_MAX_PACKET_SIZE
  21 #define RXRPC_REMOTE_PACKET_SIZE        (576 - RXRPC_IPUDP_SIZE)
  22
  23 /*****************************************************************************/
  24 /*
  25  * on-the-wire Rx packet header
  26  * - all multibyte fields should be in network byte order
  27  */
  28 struct rxrpc_header
  29 {
  30         u32     epoch;          /* client boot timestamp */
  31
  32         u32     cid;            /* connection and channel ID */
  33 #define RXRPC_MAXCALLS          4                       /* max active calls per conn */
  34 #define RXRPC_CHANNELMASK       (RXRPC_MAXCALLS-1)      /* mask for channel ID */
  35 #define RXRPC_CIDMASK           (~RXRPC_CHANNELMASK)    /* mask for connection ID */
  36 #define RXRPC_CIDSHIFT          2                       /* shift for connection ID */
  37
  38         u32     callNumber;     /* call ID (0 for connection-level packets) */
  39 #define RXRPC_PROCESS_MAXCALLS  (1<<2)  /* maximum number of active calls per conn (power of 2) */
  40
  41         u32     seq;            /* sequence number of pkt in call stream */
  42         u32     serial;         /* serial number of pkt sent to network */
  43
  44         u8      type;           /* packet type */
  45 #define RXRPC_PACKET_TYPE_DATA          1       /* data */
  46 #define RXRPC_PACKET_TYPE_ACK           2       /* ACK */
  47 #define RXRPC_PACKET_TYPE_BUSY          3       /* call reject */
  48 #define RXRPC_PACKET_TYPE_ABORT         4       /* call/connection abort */
  49 #define RXRPC_PACKET_TYPE_ACKALL        5       /* ACK all outstanding packets on call */
  50 #define RXRPC_PACKET_TYPE_CHALLENGE     6       /* connection security challenge (SRVR->CLNT) */
  51 #define RXRPC_PACKET_TYPE_RESPONSE      7       /* connection secutity response (CLNT->SRVR) */
  52 #define RXRPC_PACKET_TYPE_DEBUG         8       /* debug info request */
  53 #define RXRPC_N_PACKET_TYPES            9       /* number of packet types (incl type 0) */
  54
  55         u8      flags;          /* packet flags */
  56 #define RXRPC_CLIENT_INITIATED  0x01            /* signifies a packet generated by a client */
  57 #define RXRPC_REQUEST_ACK       0x02            /* request an unconditional ACK of this packet */
  58 #define RXRPC_LAST_PACKET       0x04            /* the last packet from this side for this call */
  59 #define RXRPC_MORE_PACKETS      0x08            /* more packets to come */
  60 #define RXRPC_JUMBO_PACKET      0x20            /* [DATA] this is a jumbo packet */
  61 #define RXRPC_SLOW_START_OK     0x20            /* [ACK] slow start supported */
  62
  63         u8      userStatus;     /* app-layer defined status */
  64         u8      securityIndex;  /* security protocol ID */
  65         u16     _rsvd;          /* reserved (used by kerberos security as cksum) */
  66         u16     serviceId;      /* service ID */
  67
  68 } __attribute__((packed));
  69
  70 #define __rxrpc_header_off(X) offsetof(struct rxrpc_header,X)
  71
  72 extern const char *rxrpc_pkts[];
  73
  74 /*****************************************************************************/
  75 /*
  76  * jumbo packet secondary header
  77  * - can be mapped to read header by:
  78  *   - new_serial = serial + 1
  79  *   - new_seq = seq + 1
  80  *   - new_flags = j_flags
  81  *   - new__rsvd = j__rsvd
  82  *   - duplicating all other fields
  83  */
  84 struct rxrpc_jumbo_header
  85 {
  86         u8      flags;          /* packet flags (as per rxrpc_header) */
  87         u8      pad;
  88         u16     _rsvd;          /* reserved (used by kerberos security as cksum) */
  89 };
  90
  91 #define RXRPC_JUMBO_DATALEN     1412    /* non-terminal jumbo packet data length */
  92
  93 /*****************************************************************************/
  94 /*
  95  * on-the-wire Rx ACK packet data payload
  96  * - all multibyte fields should be in network byte order
  97  */
  98 struct rxrpc_ackpacket
  99 {
 100         u16     bufferSpace;    /* number of packet buffers available */
 101         u16     maxSkew;        /* diff between serno being ACK'd and highest serial no received */
 102         u32     firstPacket;    /* sequence no of first ACK'd packet in attached list */
 103         u32     previousPacket; /* sequence no of previous packet received */
 104         u32     serial;         /* serial no of packet that prompted this ACK */
 105
 106         u8      reason;         /* reason for ACK */
 107 #define RXRPC_ACK_REQUESTED             1       /* ACK was requested on packet */
 108 #define RXRPC_ACK_DUPLICATE             2       /* duplicate packet received */
 109 #define RXRPC_ACK_OUT_OF_SEQUENCE       3       /* out of sequence packet received */
 110 #define RXRPC_ACK_EXCEEDS_WINDOW        4       /* packet received beyond end of ACK window */
 111 #define RXRPC_ACK_NOSPACE               5       /* packet discarded due to lack of buffer space */
 112 #define RXRPC_ACK_PING                  6       /* keep alive ACK */
 113 #define RXRPC_ACK_PING_RESPONSE         7       /* response to RXRPC_ACK_PING */
 114 #define RXRPC_ACK_DELAY                 8       /* nothing happened since received packet */
 115 #define RXRPC_ACK_IDLE                  9       /* ACK due to fully received ACK window */
 116
 117         u8      nAcks;          /* number of ACKs */
 118 #define RXRPC_MAXACKS   255
 119
 120         u8      acks[0];        /* list of ACK/NAKs */
 121 #define RXRPC_ACK_TYPE_NACK             0
 122 #define RXRPC_ACK_TYPE_ACK              1
 123
 124 } __attribute__((packed));
 125
 126 extern const char *rxrpc_acks[];
 127
 128 #endif /* _LINUX_RXRPC_PACKET_H */