/* packet.h: Rx packet layout and definitions
   *

   * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.

   * Written by David Howells (dhowells@redhat.com)
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version
   * 2 of the License, or (at your option) any later version.
   */
  
  #ifndef _LINUX_RXRPC_PACKET_H
  #define _LINUX_RXRPC_PACKET_H

  typedef u32	rxrpc_seq_t;	/* Rx message sequence number */
  typedef u32	rxrpc_serial_t;	/* Rx message serial number */
  typedef __be32	rxrpc_seq_net_t; /* on-the-wire Rx message sequence number */
  typedef __be32	rxrpc_serial_net_t; /* on-the-wire Rx message serial number */

  
  /*****************************************************************************/
  /*
   * on-the-wire Rx packet header
   * - all multibyte fields should be in network byte order
   */

  struct rxrpc_header {

  	__be32		epoch;		/* client boot timestamp */
  
  	__be32		cid;		/* connection and channel ID */
  #define RXRPC_MAXCALLS		4			/* max active calls per conn */
  #define RXRPC_CHANNELMASK	(RXRPC_MAXCALLS-1)	/* mask for channel ID */
  #define RXRPC_CIDMASK		(~RXRPC_CHANNELMASK)	/* mask for connection ID */

  #define RXRPC_CIDSHIFT		ilog2(RXRPC_MAXCALLS)	/* shift for connection ID */
  #define RXRPC_CID_INC		(1 << RXRPC_CIDSHIFT)	/* connection ID increment */

  
  	__be32		callNumber;	/* call ID (0 for connection-level packets) */
  #define RXRPC_PROCESS_MAXCALLS	(1<<2)	/* maximum number of active calls per conn (power of 2) */
  
  	__be32		seq;		/* sequence number of pkt in call stream */
  	__be32		serial;		/* serial number of pkt sent to network */
  
  	uint8_t		type;		/* packet type */
  #define RXRPC_PACKET_TYPE_DATA		1	/* data */
  #define RXRPC_PACKET_TYPE_ACK		2	/* ACK */
  #define RXRPC_PACKET_TYPE_BUSY		3	/* call reject */
  #define RXRPC_PACKET_TYPE_ABORT		4	/* call/connection abort */
  #define RXRPC_PACKET_TYPE_ACKALL	5	/* ACK all outstanding packets on call */
  #define RXRPC_PACKET_TYPE_CHALLENGE	6	/* connection security challenge (SRVR->CLNT) */
  #define RXRPC_PACKET_TYPE_RESPONSE	7	/* connection secutity response (CLNT->SRVR) */
  #define RXRPC_PACKET_TYPE_DEBUG		8	/* debug info request */
  #define RXRPC_N_PACKET_TYPES		9	/* number of packet types (incl type 0) */
  
  	uint8_t		flags;		/* packet flags */
  #define RXRPC_CLIENT_INITIATED	0x01		/* signifies a packet generated by a client */
  #define RXRPC_REQUEST_ACK	0x02		/* request an unconditional ACK of this packet */
  #define RXRPC_LAST_PACKET	0x04		/* the last packet from this side for this call */
  #define RXRPC_MORE_PACKETS	0x08		/* more packets to come */
  #define RXRPC_JUMBO_PACKET	0x20		/* [DATA] this is a jumbo packet */
  #define RXRPC_SLOW_START_OK	0x20		/* [ACK] slow start supported */
  
  	uint8_t		userStatus;	/* app-layer defined status */
  	uint8_t		securityIndex;	/* security protocol ID */

  	union {
  		__be16	_rsvd;		/* reserved */
  		__be16	cksum;		/* kerberos security checksum */
  	};

  	__be16		serviceId;	/* service ID */

  } __packed;

  
  #define __rxrpc_header_off(X) offsetof(struct rxrpc_header,X)
  
  extern const char *rxrpc_pkts[];
  
  /*****************************************************************************/
  /*
   * jumbo packet secondary header
   * - can be mapped to read header by:
   *   - new_serial = serial + 1
   *   - new_seq = seq + 1
   *   - new_flags = j_flags
   *   - new__rsvd = j__rsvd
   *   - duplicating all other fields
   */

  struct rxrpc_jumbo_header {

  	uint8_t		flags;		/* packet flags (as per rxrpc_header) */
  	uint8_t		pad;
  	__be16		_rsvd;		/* reserved (used by kerberos security as cksum) */
  };
  
  #define RXRPC_JUMBO_DATALEN	1412	/* non-terminal jumbo packet data length */
  
  /*****************************************************************************/
  /*
   * on-the-wire Rx ACK packet data payload
   * - all multibyte fields should be in network byte order
   */

  struct rxrpc_ackpacket {

  	__be16		bufferSpace;	/* number of packet buffers available */
  	__be16		maxSkew;	/* diff between serno being ACK'd and highest serial no
  					 * received */
  	__be32		firstPacket;	/* sequence no of first ACK'd packet in attached list */
  	__be32		previousPacket;	/* sequence no of previous packet received */
  	__be32		serial;		/* serial no of packet that prompted this ACK */
  
  	uint8_t		reason;		/* reason for ACK */
  #define RXRPC_ACK_REQUESTED		1	/* ACK was requested on packet */
  #define RXRPC_ACK_DUPLICATE		2	/* duplicate packet received */
  #define RXRPC_ACK_OUT_OF_SEQUENCE	3	/* out of sequence packet received */
  #define RXRPC_ACK_EXCEEDS_WINDOW	4	/* packet received beyond end of ACK window */
  #define RXRPC_ACK_NOSPACE		5	/* packet discarded due to lack of buffer space */
  #define RXRPC_ACK_PING			6	/* keep alive ACK */
  #define RXRPC_ACK_PING_RESPONSE		7	/* response to RXRPC_ACK_PING */
  #define RXRPC_ACK_DELAY			8	/* nothing happened since received packet */
  #define RXRPC_ACK_IDLE			9	/* ACK due to fully received ACK window */
  
  	uint8_t		nAcks;		/* number of ACKs */
  #define RXRPC_MAXACKS	255
  
  	uint8_t		acks[0];	/* list of ACK/NAKs */
  #define RXRPC_ACK_TYPE_NACK		0
  #define RXRPC_ACK_TYPE_ACK		1

  } __packed;

  /*
   * ACK packets can have a further piece of information tagged on the end
   */
  struct rxrpc_ackinfo {
  	__be32		rxMTU;		/* maximum Rx MTU size (bytes) [AFS 3.3] */
  	__be32		maxMTU;		/* maximum interface MTU size (bytes) [AFS 3.3] */
  	__be32		rwind;		/* Rx window size (packets) [AFS 3.4] */
  	__be32		jumbo_max;	/* max packets to stick into a jumbo packet [AFS 3.5] */
  };
  
  /*****************************************************************************/
  /*
   * Kerberos security type-2 challenge packet
   */
  struct rxkad_challenge {
  	__be32		version;	/* version of this challenge type */
  	__be32		nonce;		/* encrypted random number */
  	__be32		min_level;	/* minimum security level */
  	__be32		__padding;	/* padding to 8-byte boundary */

  } __packed;

  
  /*****************************************************************************/
  /*
   * Kerberos security type-2 response packet
   */
  struct rxkad_response {

  	__be32		version;	/* version of this response type */

  	__be32		__pad;
  
  	/* encrypted bit of the response */
  	struct {
  		__be32		epoch;		/* current epoch */
  		__be32		cid;		/* parent connection ID */
  		__be32		checksum;	/* checksum */
  		__be32		securityIndex;	/* security type */
  		__be32		call_id[4];	/* encrypted call IDs */
  		__be32		inc_nonce;	/* challenge nonce + 1 */
  		__be32		level;		/* desired level */
  	} encrypted;
  
  	__be32		kvno;		/* Kerberos key version number */
  	__be32		ticket_len;	/* Kerberos ticket length  */

  } __packed;

  
  /*****************************************************************************/
  /*
   * RxRPC-level abort codes
   */
  #define RX_CALL_DEAD		-1	/* call/conn has been inactive and is shut down */
  #define RX_INVALID_OPERATION	-2	/* invalid operation requested / attempted */
  #define RX_CALL_TIMEOUT		-3	/* call timeout exceeded */
  #define RX_EOF			-4	/* unexpected end of data on read op */
  #define RX_PROTOCOL_ERROR	-5	/* low-level protocol error */
  #define RX_USER_ABORT		-6	/* generic user abort */
  #define RX_ADDRINUSE		-7	/* UDP port in use */
  #define RX_DEBUGI_BADTYPE	-8	/* bad debugging packet type */
  
  /*

   * (un)marshalling abort codes (rxgen)
   */
  #define	RXGEN_CC_MARSHAL    -450
  #define	RXGEN_CC_UNMARSHAL  -451
  #define	RXGEN_SS_MARSHAL    -452
  #define	RXGEN_SS_UNMARSHAL  -453
  #define	RXGEN_DECODE	    -454
  #define	RXGEN_OPCODE	    -455
  #define	RXGEN_SS_XDRFREE    -456
  #define	RXGEN_CC_XDRFREE    -457
  
  /*

   * Rx kerberos security abort codes
   * - unfortunately we have no generalised security abort codes to say things
   *   like "unsupported security", so we have to use these instead and hope the
   *   other side understands
   */
  #define RXKADINCONSISTENCY	19270400	/* security module structure inconsistent */
  #define RXKADPACKETSHORT	19270401	/* packet too short for security challenge */
  #define RXKADLEVELFAIL		19270402	/* security level negotiation failed */
  #define RXKADTICKETLEN		19270403	/* ticket length too short or too long */
  #define RXKADOUTOFSEQUENCE	19270404	/* packet had bad sequence number */
  #define RXKADNOAUTH		19270405	/* caller not authorised */
  #define RXKADBADKEY		19270406	/* illegal key: bad parity or weak */
  #define RXKADBADTICKET		19270407	/* security object was passed a bad ticket */
  #define RXKADUNKNOWNKEY		19270408	/* ticket contained unknown key version number */
  #define RXKADEXPIRED		19270409	/* authentication expired */
  #define RXKADSEALEDINCON	19270410	/* sealed data inconsistent */
  #define RXKADDATALEN		19270411	/* user data too long */
  #define RXKADILLEGALLEVEL	19270412	/* caller not authorised to use encrypted conns */

  #endif /* _LINUX_RXRPC_PACKET_H */