net/rxrpc/protocol.h

   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
  11 typedef u32     rxrpc_seq_t;    /* Rx message sequence number */
  12 typedef u32     rxrpc_serial_t; /* Rx message serial number */
  13 typedef __be32  rxrpc_seq_net_t; /* on-the-wire Rx message sequence number */
  14 typedef __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  */
  21 struct 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  */
  80 struct 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  */
 106 struct 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  */
 145 struct 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  */
 156 struct 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  */
 167 struct 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 */