iSCSITypesKernel.h

/*
 * Copyright (c) 2016, Nareg Sinenian
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef __ISCSI_TYPES_KERNEL_H__
#define __ISCSI_TYPES_KERNEL_H__


#include <IOKit/IOLib.h>
#include <sys/socket.h>

#include "iSCSITypesShared.h"

class iSCSITaskQueue;
class iSCSIIOEventSource;

/*! Definition of a single connection that is associated with a particular
 *  iSCSI session. */
typedef struct iSCSIConnection {
    
    /*! Status sequence number expected by the initiator. */
    UInt32 expStatSN;
    
    /*! Connection ID. */
    CID cid; // Might need this for ErrorRecovery (otherwise have to search through list for it)
    
    /*! Portal address (IPv4/IPv6/DNS address). */
    OSString * portalAddress;
    
    /*! TCP port used for the connection. */
    OSString * portalPort;
    
    /*! Host inteface used for the connection. */
    OSString * hostInteface;
    
    /*! Target tag for current transfer. */
    //    UInt32 targetTransferTag;  /// NEED THIS???
    
    /*! Socket used for communication. */
    socket_t socket;
    
    /*! Used to keep track of R2T PDUs. */
    UInt32 R2TSN;
    
    /*! iSCSI task queue used to manage tasks for this connection. */
    iSCSITaskQueue * taskQueue;

    /*! Event source used to signal the Virtual HBA that data has been
     *  received and needs to be processed. */
    iSCSIIOEventSource * dataRecvEventSource;
    
    /*! Amount of data, in bytes, that this connection has been requested
     *  to transfer.  This is used for bitrate-based load balancing. */
    UInt64 dataToTransfer;
    
    /*! The maximum length of data allowed for immediate data (data sent as part
     *  of a command PDU).  This parameter is derived by taking the lesser of
     *  the FirstBurstLength and the maxSendDataSegmentLength.  The former
     *  is a session option while the latter is a connection option. */
    UInt32 immediateDataLength;
    
    /*! Keeps track of when processing began for a particualr task, as
     *  represented by the system uptime (seconds component). */
    clock_sec_t taskStartTimeSec;
    
    /*! Keeps track of when processing began for a particualr task, as
     *  represented by the system uptime (microseconds component). */
    clock_usec_t taskStartTimeUSec;
    
    /*! Keeps track of the iSCSI data transfer rate of this connection,
     *  in units of bytes per second.  This number is obtained by averaging
     *  over 5 tasks. */
    UInt32 bytesPerSecond;
    
    /*! Size of moving average (# points) to use to compute average speed. */
    static const UInt8 kBytesPerSecAvgWindowSize = 30;
    
    /*! Last few measurements of bytes per second on this connection. */
    UInt32 bytesPerSecondHistory[kBytesPerSecAvgWindowSize];
    
    /*! Keeps track of the index in the above array should be populated next. */
    UInt8 bytesPerSecHistoryIdx;
    
    /*! Keeps track of the connection latency (ms). */
    UInt32 latency_ms;
    
    //////////////////// Configured Connection Parameters /////////////////////
    
    /*! Flag that indicates if this connection uses header digests. */
    bool useHeaderDigest;
    
    /*! Flag that indicates if this connection uses data digests. */
    bool useDataDigest;
    
    /*! Flag that indicates if this connection uses IF markers. */
    bool useIFMarker;
    
    /*! Flag that indicates if this connection uses OF markers. */
    bool useOFMarker;
    
    /*! Interval for OF marker. */
    UInt16 OFMarkInt;
    
    /*! Interval for IF marker. */
    UInt16 IFMarkInt;
    
    /*! Maximum data segment length allowed by the target. */
    UInt32 maxSendDataSegmentLength;
    
    /*! Maximum data segment length initiator can receive. */
    UInt32 maxRecvDataSegmentLength;

    
} iSCSIConnection;


/*! Definition of a single iSCSI session.  Each session is comprised of one
 *  or more connections as defined by the struct iSCSIConnection.  Each session
 *  is further associated with an initiator session ID (ISID), a target session
 *  ID (TSIH), a target IP address, a target name, and a target alias. */
typedef struct iSCSISession {
    
    /*! The initiator session ID, which is also used as the target ID within
     *  this kernel extension since there is a 1-1 mapping. */
    SID sessionId;
    
    /*! Command sequence number to be used for the next initiator command. */
    UInt32 cmdSN;
    
    /*! Command seqeuence number expected by the target. */
    UInt32 expCmdSN;
    
    /*! Maximum command seqeuence number allowed. */
    UInt32 maxCmdSN;
    
    /*! Connections associated with this session. */
    iSCSIConnection * * connections;
    
    /*! Number of active connections. */
    UInt32 numActiveConnections;
        
    /*! Indicates whether session is active, which means that a SCSI target
     *  exists and is backing the the iSCSI session. */
    bool active;
    
    //////////////////// Configured Session Parameters /////////////////////
    
    /*! Time to retain. */
    UInt16 defaultTime2Retain;
    
    /*! Time to wait. */
    UInt16 defaultTime2Wait;
    
    /*! Error recovery level. */
    UInt8 errorRecoveryLevel;
    
    /*! Max connections supported by target. */
    UInt32 maxConnections;
    
    /*! Send data immediately. */
    bool immediateData;
    
    /*!  Expect an initial R2T from target. */
    bool initialR2T;
    
    /*! Data PDUs in order. */
    bool dataPDUInOrder;
    
    /*! Data sequence in order. */
    bool dataSequenceInOrder;
    
    /*! Number of outstanding R2Ts allowed. */
    UInt16 maxOutStandingR2T;
    
    /*! Maximum data burst length (in bytes). */
    UInt32 maxBurstLength;
    
    /*! First data burst length (in bytes). */
    UInt32 firstBurstLength;
    
    /*! Target session identifying handle. */
    TSIH targetSessionId;
    
    /*! Target portal group tag. */
    TPGT targetPortalGroupTag;
    
} iSCSISession;

#endif /* defined(__ISCSI_TYPES_KERNEL_H__) */