SCSI Inquiry Data - scsi

Question

I am new to SCSI Programming and hence sorry for asking basic question. I sent SCSI Inquiry command to a Tape Device through 6 byte CDB
ccb = (Exec_IO_CCB *)( buffer + header_size );
ccb->ccb_length = sizeof(Exec_IO_CCB);
ccb->cam_opcode = 0x1;
ccb->connect_id = 0;
ccb->sense_buf_ptr = (long)(header_size + ccb->ccb_length);
ccb->sense_buf_length = MAX_SENSE_LEN;
ccb->time_out = CAM_TIMEOUT;
ccb->cdb_length = 6;
/* For INQUIRY sets cam_flags and cdb[0] */
ccb->cam_flags = NO_DATA;
ccb->cdb[0] = INQUIRY; /* 0x12 SCSI Opcode for Inquiry Command */
ccb->cdb[1] = 0;
ccb->cdb[2] = 0;
ccb->cdb[3] = 0;
ccb->cdb[4] = 3200;
ccb->cdb[5] = 0;
The SCSI Command is successful . How do i capture the output of INQUIRY command so that i can get
Vendor ID / Product ID ??
I have declared the Execute I/O SCSI buffer as follows
typedef struct {
long ccb_address; /* Address of this CCB */
short ccb_length; /* CAM Control Block Length */
char cam_opcode; /* CAM Operation Code */
char status; /* CAM Status */
long connect_id; /* Connect ID - no fields supported */
long cam_flags; /* CAM Flags */
long pd_pointer; /* Peripheral driver pointer */
long next_ccb_ptr; /* Next CCB Pointer */
long req_map_info; /* Request mapping information */
long call_on_comp; /* Callback on completion */
long data_buf_ptr; /* Data Buffer Pointer */
long data_xfer_length; /* Data transfer length */
long sense_buf_ptr; /* Sense information buffer pointer */
char sense_buf_length; /* Sense information buffer length */
char cdb_length; /* Command Descriptor Block (CDB) **
** length */
short num_sg_entries; /* Number of scatter/gather entries */
long vendor_unique; /* Vendor Unique field */
char scsi_status; /* SCSI status */
char auto_resid; /* Auto sense residual length */
short reserved; /* Reserved */
long resid_length; /* Residual length */
char cdb[12]; /* Command Descriptor Block (CDB) */
long time_out; /* Time-out value */
long msg_buf_ptr; /* Message buffer pointer */
short msg_buf_length; /* Message buffer length */
short vu_flags; /* Vendor-unique flags */
char tag_queue_act; /* Tagged Queue action */
char tag_id; /* Tag ID (target only) */
char init_id; /* Initiator ID (target only) */
char reserved2; /* Reserved */
} Exec_IO_CCB;
This structure will never capture SCSI Output ?
I have declared the Inquiry Structure as follows . But I am not sure how Inquire command will
populate Inquiry_Data structure data ??
typedef struct {
short data_valid; /* Flag that indicates whether or not the */
/* structure has been filled in with */
/* inquiry data from the device. */
byte periph_qual;
byte periph_dev_type;
byte rmb;
byte iso_version;
byte ecma_version;
byte ansi_version;
byte resp_data_format;
byte rel_adr;
byte sync;
byte linked;
byte cmd_que;
byte sft_rst;
char vendor_id[9];
char prod_id[17];
char prod_rev[5];
char reserved;
} Inquiry_Data;

Answer 1

The first thing that you have assigned a short to cdb[4], but cdb[4] is a byte. The assignment probably put a 0 there since the compiler would truncate. Since bytes 3 and 4 are the allocation length you have told the target not to send anything. Maybe you ment to assign 32 to cdb[4]; but since your Inquiry_Data structure is 44 bytes you probably want to assign 44 to cdb[4].