Projects/Webserver/Lib/SCSI.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2012.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2011  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaim all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *
  33  *  SCSI command processing routines, for SCSI commands issued by the host. Mass Storage
  34  *  devices use a thin "Bulk-Only Transport" protocol for issuing commands and status information,
  35  *  which wrap around standard SCSI device commands for controlling the actual storage medium.
  36  */
  37
  38 #define  INCLUDE_FROM_SCSI_C
  39 #include "SCSI.h"
  40
  41 /** Structure to hold the SCSI response data to a SCSI INQUIRY command. This gives information about the device's
  42  *  features and capabilities.
  43  */
  44 static const SCSI_Inquiry_Response_t InquiryData =
  45         {
  46                 .DeviceType          = DEVICE_TYPE_BLOCK,
  47                 .PeripheralQualifier = 0,
  48
  49                 .Removable           = true,
  50
  51                 .Version             = 0,
  52
  53                 .ResponseDataFormat  = 2,
  54                 .NormACA             = false,
  55                 .TrmTsk              = false,
  56                 .AERC                = false,
  57
  58                 .AdditionalLength    = 0x1F,
  59
  60                 .SoftReset           = false,
  61                 .CmdQue              = false,
  62                 .Linked              = false,
  63                 .Sync                = false,
  64                 .WideBus16Bit        = false,
  65                 .WideBus32Bit        = false,
  66                 .RelAddr             = false,
  67
  68                 .VendorID            = "LUFA",
  69                 .ProductID           = "Dataflash Disk",
  70                 .RevisionID          = {'0','.','0','0'},
  71         };
  72
  73 /** Structure to hold the sense data for the last issued SCSI command, which is returned to the host after a SCSI REQUEST SENSE
  74  *  command is issued. This gives information on exactly why the last command failed to complete.
  75  */
  76 static SCSI_Request_Sense_Response_t SenseData =
  77         {
  78                 .ResponseCode        = 0x70,
  79                 .AdditionalLength    = 0x0A,
  80         };
  81
  82
  83 /** Main routine to process the SCSI command located in the Command Block Wrapper read from the host. This dispatches
  84  *  to the appropriate SCSI command handling routine if the issued command is supported by the device, else it returns
  85  *  a command failure due to a ILLEGAL REQUEST.
  86  *
  87  *  \param[in] MSInterfaceInfo  Pointer to the Mass Storage class interface structure that the command is associated with
  88  *
  89  *  \return Boolean true if the command completed successfully, false otherwise
  90  */
  91 bool SCSI_DecodeSCSICommand(USB_ClassInfo_MS_Device_t* const MSInterfaceInfo)
  92 {
  93         bool CommandSuccess = false;
  94
  95         /* Run the appropriate SCSI command hander function based on the passed command */
  96         switch (MSInterfaceInfo->State.CommandBlock.SCSICommandData[0])
  97         {
  98                 case SCSI_CMD_INQUIRY:
  99                         CommandSuccess = SCSI_Command_Inquiry(MSInterfaceInfo);
 100                         break;
 101                 case SCSI_CMD_REQUEST_SENSE:
 102                         CommandSuccess = SCSI_Command_Request_Sense(MSInterfaceInfo);
 103                         break;
 104                 case SCSI_CMD_READ_CAPACITY_10:
 105                         CommandSuccess = SCSI_Command_Read_Capacity_10(MSInterfaceInfo);
 106                         break;
 107                 case SCSI_CMD_SEND_DIAGNOSTIC:
 108                         CommandSuccess = SCSI_Command_Send_Diagnostic(MSInterfaceInfo);
 109                         break;
 110                 case SCSI_CMD_WRITE_10:
 111                         CommandSuccess = SCSI_Command_ReadWrite_10(MSInterfaceInfo, DATA_WRITE);
 112                         break;
 113                 case SCSI_CMD_READ_10:
 114                         CommandSuccess = SCSI_Command_ReadWrite_10(MSInterfaceInfo, DATA_READ);
 115                         break;
 116                 case SCSI_CMD_MODE_SENSE_6:
 117                         CommandSuccess = SCSI_Command_ModeSense_6(MSInterfaceInfo);
 118                         break;
 119                 case SCSI_CMD_TEST_UNIT_READY:
 120                 case SCSI_CMD_PREVENT_ALLOW_MEDIUM_REMOVAL:
 121                 case SCSI_CMD_VERIFY_10:
 122                         /* These commands should just succeed, no handling required */
 123                         CommandSuccess = true;
 124                         MSInterfaceInfo->State.CommandBlock.DataTransferLength = 0;
 125                         break;
 126                 default:
 127                         /* Update the SENSE key to reflect the invalid command */
 128                         SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 129                                    SCSI_ASENSE_INVALID_COMMAND,
 130                                    SCSI_ASENSEQ_NO_QUALIFIER);
 131                         break;
 132         }
 133
 134         /* Check if command was successfully processed */
 135         if (CommandSuccess)
 136         {
 137                 SCSI_SET_SENSE(SCSI_SENSE_KEY_GOOD,
 138                                SCSI_ASENSE_NO_ADDITIONAL_INFORMATION,
 139                                SCSI_ASENSEQ_NO_QUALIFIER);
 140
 141                 return true;
 142         }
 143
 144         return false;
 145 }
 146
 147 /** Command processing for an issued SCSI INQUIRY command. This command returns information about the device's features
 148  *  and capabilities to the host.
 149  *
 150  *  \param[in] MSInterfaceInfo  Pointer to the Mass Storage class interface structure that the command is associated with
 151  *
 152  *  \return Boolean true if the command completed successfully, false otherwise.
 153  */
 154 static bool SCSI_Command_Inquiry(USB_ClassInfo_MS_Device_t* const MSInterfaceInfo)
 155 {
 156         uint16_t AllocationLength  = SwapEndian_16(*(uint16_t*)&MSInterfaceInfo->State.CommandBlock.SCSICommandData[3]);
 157         uint16_t BytesTransferred  = MIN(AllocationLength, sizeof(InquiryData));
 158
 159         /* Only the standard INQUIRY data is supported, check if any optional INQUIRY bits set */
 160         if ((MSInterfaceInfo->State.CommandBlock.SCSICommandData[1] & ((1 << 0) | (1 << 1))) ||
 161              MSInterfaceInfo->State.CommandBlock.SCSICommandData[2])
 162         {
 163                 /* Optional but unsupported bits set - update the SENSE key and fail the request */
 164                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 165                                SCSI_ASENSE_INVALID_FIELD_IN_CDB,
 166                                SCSI_ASENSEQ_NO_QUALIFIER);
 167
 168                 return false;
 169         }
 170
 171         Endpoint_Write_Stream_LE(&InquiryData, BytesTransferred, NULL);
 172
 173         /* Pad out remaining bytes with 0x00 */
 174         Endpoint_Null_Stream((AllocationLength - BytesTransferred), NULL);
 175
 176         /* Finalize the stream transfer to send the last packet */
 177         Endpoint_ClearIN();
 178
 179         /* Succeed the command and update the bytes transferred counter */
 180         MSInterfaceInfo->State.CommandBlock.DataTransferLength -= BytesTransferred;
 181
 182         return true;
 183 }
 184
 185 /** Command processing for an issued SCSI REQUEST SENSE command. This command returns information about the last issued command,
 186  *  including the error code and additional error information so that the host can determine why a command failed to complete.
 187  *
 188  *  \param[in] MSInterfaceInfo  Pointer to the Mass Storage class interface structure that the command is associated with
 189  *
 190  *  \return Boolean true if the command completed successfully, false otherwise.
 191  */
 192 static bool SCSI_Command_Request_Sense(USB_ClassInfo_MS_Device_t* const MSInterfaceInfo)
 193 {
 194         uint8_t  AllocationLength = MSInterfaceInfo->State.CommandBlock.SCSICommandData[4];
 195         uint8_t  BytesTransferred = MIN(AllocationLength, sizeof(SenseData));
 196
 197         Endpoint_Write_Stream_LE(&SenseData, BytesTransferred, NULL);
 198         Endpoint_Null_Stream((AllocationLength - BytesTransferred), NULL);
 199         Endpoint_ClearIN();
 200
 201         /* Succeed the command and update the bytes transferred counter */
 202         MSInterfaceInfo->State.CommandBlock.DataTransferLength -= BytesTransferred;
 203
 204         return true;
 205 }
 206
 207 /** Command processing for an issued SCSI READ CAPACITY (10) command. This command returns information about the device's capacity
 208  *  on the selected Logical Unit (drive), as a number of OS-sized blocks.
 209  *
 210  *  \param[in] MSInterfaceInfo  Pointer to the Mass Storage class interface structure that the command is associated with
 211  *
 212  *  \return Boolean true if the command completed successfully, false otherwise.
 213  */
 214 static bool SCSI_Command_Read_Capacity_10(USB_ClassInfo_MS_Device_t* const MSInterfaceInfo)
 215 {
 216         uint32_t LastBlockAddressInLUN = (VIRTUAL_MEMORY_BLOCKS - 1);
 217         uint32_t MediaBlockSize        = VIRTUAL_MEMORY_BLOCK_SIZE;
 218
 219         Endpoint_Write_Stream_BE(&LastBlockAddressInLUN, sizeof(LastBlockAddressInLUN), NULL);
 220         Endpoint_Write_Stream_BE(&MediaBlockSize, sizeof(MediaBlockSize), NULL);
 221         Endpoint_ClearIN();
 222
 223         /* Succeed the command and update the bytes transferred counter */
 224         MSInterfaceInfo->State.CommandBlock.DataTransferLength -= 8;
 225
 226         return true;
 227 }
 228
 229 /** Command processing for an issued SCSI SEND DIAGNOSTIC command. This command performs a quick check of the Dataflash ICs on the
 230  *  board, and indicates if they are present and functioning correctly. Only the Self-Test portion of the diagnostic command is
 231  *  supported.
 232  *
 233  *  \param[in] MSInterfaceInfo  Pointer to the Mass Storage class interface structure that the command is associated with
 234  *
 235  *  \return Boolean true if the command completed successfully, false otherwise.
 236  */
 237 static bool SCSI_Command_Send_Diagnostic(USB_ClassInfo_MS_Device_t* const MSInterfaceInfo)
 238 {
 239         /* Check to see if the SELF TEST bit is not set */
 240         if (!(MSInterfaceInfo->State.CommandBlock.SCSICommandData[1] & (1 << 2)))
 241         {
 242                 /* Only self-test supported - update SENSE key and fail the command */
 243                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 244                                SCSI_ASENSE_INVALID_FIELD_IN_CDB,
 245                                SCSI_ASENSEQ_NO_QUALIFIER);
 246
 247                 return false;
 248         }
 249
 250         /* Check to see if all attached Dataflash ICs are functional */
 251         if (!(DataflashManager_CheckDataflashOperation()))
 252         {
 253                 /* Update SENSE key with a hardware error condition and return command fail */
 254                 SCSI_SET_SENSE(SCSI_SENSE_KEY_HARDWARE_ERROR,
 255                                SCSI_ASENSE_NO_ADDITIONAL_INFORMATION,
 256                                SCSI_ASENSEQ_NO_QUALIFIER);
 257
 258                 return false;
 259         }
 260
 261         /* Succeed the command and update the bytes transferred counter */
 262         MSInterfaceInfo->State.CommandBlock.DataTransferLength = 0;
 263
 264         return true;
 265 }
 266
 267 /** Command processing for an issued SCSI READ (10) or WRITE (10) command. This command reads in the block start address
 268  *  and total number of blocks to process, then calls the appropriate low-level Dataflash routine to handle the actual
 269  *  reading and writing of the data.
 270  *
 271  *  \param[in] MSInterfaceInfo  Pointer to the Mass Storage class interface structure that the command is associated with
 272  *  \param[in] IsDataRead  Indicates if the command is a READ (10) command or WRITE (10) command (DATA_READ or DATA_WRITE)
 273  *
 274  *  \return Boolean true if the command completed successfully, false otherwise.
 275  */
 276 static bool SCSI_Command_ReadWrite_10(USB_ClassInfo_MS_Device_t* const MSInterfaceInfo,
 277                                       const bool IsDataRead)
 278 {
 279         uint32_t BlockAddress;
 280         uint16_t TotalBlocks;
 281
 282         /* Check if the disk is write protected or not */
 283         if ((IsDataRead == DATA_WRITE) && DISK_READ_ONLY)
 284         {
 285                 /* Block address is invalid, update SENSE key and return command fail */
 286                 SCSI_SET_SENSE(SCSI_SENSE_KEY_DATA_PROTECT,
 287                                SCSI_ASENSE_WRITE_PROTECTED,
 288                                SCSI_ASENSEQ_NO_QUALIFIER);
 289
 290                 return false;
 291         }
 292
 293         /* Load in the 32-bit block address (SCSI uses big-endian, so have to reverse the byte order) */
 294         BlockAddress = SwapEndian_32(*(uint32_t*)&MSInterfaceInfo->State.CommandBlock.SCSICommandData[2]);
 295
 296         /* Load in the 16-bit total blocks (SCSI uses big-endian, so have to reverse the byte order) */
 297         TotalBlocks  = SwapEndian_16(*(uint16_t*)&MSInterfaceInfo->State.CommandBlock.SCSICommandData[7]);
 298
 299         /* Check if the block address is outside the maximum allowable value for the LUN */
 300         if (BlockAddress >= VIRTUAL_MEMORY_BLOCKS)
 301         {
 302                 /* Block address is invalid, update SENSE key and return command fail */
 303                 SCSI_SET_SENSE(SCSI_SENSE_KEY_ILLEGAL_REQUEST,
 304                                SCSI_ASENSE_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE,
 305                                SCSI_ASENSEQ_NO_QUALIFIER);
 306
 307                 return false;
 308         }
 309
 310         /* Determine if the packet is a READ (10) or WRITE (10) command, call appropriate function */
 311         if (IsDataRead == DATA_READ)
 312           DataflashManager_ReadBlocks(MSInterfaceInfo, BlockAddress, TotalBlocks);
 313         else
 314           DataflashManager_WriteBlocks(MSInterfaceInfo, BlockAddress, TotalBlocks);
 315
 316         /* Update the bytes transferred counter and succeed the command */
 317         MSInterfaceInfo->State.CommandBlock.DataTransferLength -= ((uint32_t)TotalBlocks * VIRTUAL_MEMORY_BLOCK_SIZE);
 318
 319         return true;
 320 }
 321
 322 /** Command processing for an issued SCSI MODE SENSE (6) command. This command returns various informational pages about
 323  *  the SCSI device, as well as the device's Write Protect status.
 324  *
 325  *  \param[in] MSInterfaceInfo  Pointer to the Mass Storage class interface structure that the command is associated with
 326  *
 327  *  \return Boolean true if the command completed successfully, false otherwise.
 328  */
 329 static bool SCSI_Command_ModeSense_6(USB_ClassInfo_MS_Device_t* const MSInterfaceInfo)
 330 {
 331         /* Send an empty header response with the Write Protect flag status */
 332         Endpoint_Write_8(0x00);
 333         Endpoint_Write_8(0x00);
 334         Endpoint_Write_8(DISK_READ_ONLY ? 0x80 : 0x00);
 335         Endpoint_Write_8(0x00);
 336         Endpoint_ClearIN();
 337
 338         /* Update the bytes transferred counter and succeed the command */
 339         MSInterfaceInfo->State.CommandBlock.DataTransferLength -= 4;
 340
 341         return true;
 342 }
 343