linux/net/rxrpc/protocol.h
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   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/* packet.h: Rx packet layout and definitions
   3 *
   4 * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
   5 * Written by David Howells (dhowells@redhat.com)
   6 */
   7
   8#ifndef _LINUX_RXRPC_PACKET_H
   9#define _LINUX_RXRPC_PACKET_H
  10
  11typedef u32     rxrpc_seq_t;    /* Rx message sequence number */
  12typedef u32     rxrpc_serial_t; /* Rx message serial number */
  13typedef __be32  rxrpc_seq_net_t; /* on-the-wire Rx message sequence number */
  14typedef __be32  rxrpc_serial_net_t; /* on-the-wire Rx message serial number */
  15
  16/*****************************************************************************/
  17/*
  18 * on-the-wire Rx packet header
  19 * - all multibyte fields should be in network byte order
  20 */
  21struct rxrpc_wire_header {
  22        __be32          epoch;          /* client boot timestamp */
  23#define RXRPC_RANDOM_EPOCH      0x80000000      /* Random if set, date-based if not */
  24
  25        __be32          cid;            /* connection and channel ID */
  26#define RXRPC_MAXCALLS          4                       /* max active calls per conn */
  27#define RXRPC_CHANNELMASK       (RXRPC_MAXCALLS-1)      /* mask for channel ID */
  28#define RXRPC_CIDMASK           (~RXRPC_CHANNELMASK)    /* mask for connection ID */
  29#define RXRPC_CIDSHIFT          ilog2(RXRPC_MAXCALLS)   /* shift for connection ID */
  30#define RXRPC_CID_INC           (1 << RXRPC_CIDSHIFT)   /* connection ID increment */
  31
  32        __be32          callNumber;     /* call ID (0 for connection-level packets) */
  33        __be32          seq;            /* sequence number of pkt in call stream */
  34        __be32          serial;         /* serial number of pkt sent to network */
  35
  36        uint8_t         type;           /* packet type */
  37#define RXRPC_PACKET_TYPE_DATA          1       /* data */
  38#define RXRPC_PACKET_TYPE_ACK           2       /* ACK */
  39#define RXRPC_PACKET_TYPE_BUSY          3       /* call reject */
  40#define RXRPC_PACKET_TYPE_ABORT         4       /* call/connection abort */
  41#define RXRPC_PACKET_TYPE_ACKALL        5       /* ACK all outstanding packets on call */
  42#define RXRPC_PACKET_TYPE_CHALLENGE     6       /* connection security challenge (SRVR->CLNT) */
  43#define RXRPC_PACKET_TYPE_RESPONSE      7       /* connection secutity response (CLNT->SRVR) */
  44#define RXRPC_PACKET_TYPE_DEBUG         8       /* debug info request */
  45#define RXRPC_PACKET_TYPE_PARAMS        9       /* Parameter negotiation (unspec'd, ignore) */
  46#define RXRPC_PACKET_TYPE_10            10      /* Ignored */
  47#define RXRPC_PACKET_TYPE_11            11      /* Ignored */
  48#define RXRPC_PACKET_TYPE_VERSION       13      /* version string request */
  49
  50        uint8_t         flags;          /* packet flags */
  51#define RXRPC_CLIENT_INITIATED  0x01            /* signifies a packet generated by a client */
  52#define RXRPC_REQUEST_ACK       0x02            /* request an unconditional ACK of this packet */
  53#define RXRPC_LAST_PACKET       0x04            /* the last packet from this side for this call */
  54#define RXRPC_MORE_PACKETS      0x08            /* more packets to come */
  55#define RXRPC_JUMBO_PACKET      0x20            /* [DATA] this is a jumbo packet */
  56#define RXRPC_SLOW_START_OK     0x20            /* [ACK] slow start supported */
  57
  58        uint8_t         userStatus;     /* app-layer defined status */
  59#define RXRPC_USERSTATUS_SERVICE_UPGRADE 0x01   /* AuriStor service upgrade request */
  60        
  61        uint8_t         securityIndex;  /* security protocol ID */
  62        union {
  63                __be16  _rsvd;          /* reserved */
  64                __be16  cksum;          /* kerberos security checksum */
  65        };
  66        __be16          serviceId;      /* service ID */
  67
  68} __packed;
  69
  70/*****************************************************************************/
  71/*
  72 * jumbo packet secondary header
  73 * - can be mapped to read header by:
  74 *   - new_serial = serial + 1
  75 *   - new_seq = seq + 1
  76 *   - new_flags = j_flags
  77 *   - new__rsvd = j__rsvd
  78 *   - duplicating all other fields
  79 */
  80struct rxrpc_jumbo_header {
  81        uint8_t         flags;          /* packet flags (as per rxrpc_header) */
  82        uint8_t         pad;
  83        union {
  84                __be16  _rsvd;          /* reserved */
  85                __be16  cksum;          /* kerberos security checksum */
  86        };
  87};
  88
  89#define RXRPC_JUMBO_DATALEN     1412    /* non-terminal jumbo packet data length */
  90#define RXRPC_JUMBO_SUBPKTLEN   (RXRPC_JUMBO_DATALEN + sizeof(struct rxrpc_jumbo_header))
  91
  92/*
  93 * The maximum number of subpackets that can possibly fit in a UDP packet is:
  94 *
  95 *      ((max_IP - IP_hdr - UDP_hdr) / RXRPC_JUMBO_SUBPKTLEN) + 1
  96 *      = ((65535 - 28 - 28) / 1416) + 1
  97 *      = 46 non-terminal packets and 1 terminal packet.
  98 */
  99#define RXRPC_MAX_NR_JUMBO      47
 100
 101/*****************************************************************************/
 102/*
 103 * on-the-wire Rx ACK packet data payload
 104 * - all multibyte fields should be in network byte order
 105 */
 106struct rxrpc_ackpacket {
 107        __be16          bufferSpace;    /* number of packet buffers available */
 108        __be16          maxSkew;        /* diff between serno being ACK'd and highest serial no
 109                                         * received */
 110        __be32          firstPacket;    /* sequence no of first ACK'd packet in attached list */
 111        __be32          previousPacket; /* sequence no of previous packet received */
 112        __be32          serial;         /* serial no of packet that prompted this ACK */
 113
 114        uint8_t         reason;         /* reason for ACK */
 115#define RXRPC_ACK_REQUESTED             1       /* ACK was requested on packet */
 116#define RXRPC_ACK_DUPLICATE             2       /* duplicate packet received */
 117#define RXRPC_ACK_OUT_OF_SEQUENCE       3       /* out of sequence packet received */
 118#define RXRPC_ACK_EXCEEDS_WINDOW        4       /* packet received beyond end of ACK window */
 119#define RXRPC_ACK_NOSPACE               5       /* packet discarded due to lack of buffer space */
 120#define RXRPC_ACK_PING                  6       /* keep alive ACK */
 121#define RXRPC_ACK_PING_RESPONSE         7       /* response to RXRPC_ACK_PING */
 122#define RXRPC_ACK_DELAY                 8       /* nothing happened since received packet */
 123#define RXRPC_ACK_IDLE                  9       /* ACK due to fully received ACK window */
 124#define RXRPC_ACK__INVALID              10      /* Representation of invalid ACK reason */
 125
 126        uint8_t         nAcks;          /* number of ACKs */
 127#define RXRPC_MAXACKS   255
 128
 129        uint8_t         acks[0];        /* list of ACK/NAKs */
 130#define RXRPC_ACK_TYPE_NACK             0
 131#define RXRPC_ACK_TYPE_ACK              1
 132
 133} __packed;
 134
 135/* Some ACKs refer to specific packets and some are general and can be updated. */
 136#define RXRPC_ACK_UPDATEABLE ((1 << RXRPC_ACK_REQUESTED)        |       \
 137                              (1 << RXRPC_ACK_PING_RESPONSE)    |       \
 138                              (1 << RXRPC_ACK_DELAY)            |       \
 139                              (1 << RXRPC_ACK_IDLE))
 140
 141
 142/*
 143 * ACK packets can have a further piece of information tagged on the end
 144 */
 145struct rxrpc_ackinfo {
 146        __be32          rxMTU;          /* maximum Rx MTU size (bytes) [AFS 3.3] */
 147        __be32          maxMTU;         /* maximum interface MTU size (bytes) [AFS 3.3] */
 148        __be32          rwind;          /* Rx window size (packets) [AFS 3.4] */
 149        __be32          jumbo_max;      /* max packets to stick into a jumbo packet [AFS 3.5] */
 150};
 151
 152/*****************************************************************************/
 153/*
 154 * Kerberos security type-2 challenge packet
 155 */
 156struct rxkad_challenge {
 157        __be32          version;        /* version of this challenge type */
 158        __be32          nonce;          /* encrypted random number */
 159        __be32          min_level;      /* minimum security level */
 160        __be32          __padding;      /* padding to 8-byte boundary */
 161} __packed;
 162
 163/*****************************************************************************/
 164/*
 165 * Kerberos security type-2 response packet
 166 */
 167struct rxkad_response {
 168        __be32          version;        /* version of this response type */
 169        __be32          __pad;
 170
 171        /* encrypted bit of the response */
 172        struct {
 173                __be32          epoch;          /* current epoch */
 174                __be32          cid;            /* parent connection ID */
 175                __be32          checksum;       /* checksum */
 176                __be32          securityIndex;  /* security type */
 177                __be32          call_id[4];     /* encrypted call IDs */
 178                __be32          inc_nonce;      /* challenge nonce + 1 */
 179                __be32          level;          /* desired level */
 180        } encrypted;
 181
 182        __be32          kvno;           /* Kerberos key version number */
 183        __be32          ticket_len;     /* Kerberos ticket length  */
 184} __packed;
 185
 186#endif /* _LINUX_RXRPC_PACKET_H */
 187