通過一個函數發送各種scsi命令

Question

我一直在玩scsi命令，我可以發送一些基本的命令，如不同的查詢等。

我一直在使用這個例子來產生我的詢問。我正在努力使這個例子與不同的scsi命令一起工作。

http://www.tldp.org/HOWTO/SCSI-Generic-HOWTO/pexample.html

我已經改變的功能以接受通過一個結構不同的SCSI命令和它也返回基於輸出一個結構。這完美地進行調查。但是，如果我發送讀取容量（16）命令的if語句的功能觸發：

(io_hdr.info & SG_INFO_OK_MASK) != SG_INFO_OK) 

我是新來的SCSI編程，所以我可能會做一些完全錯誤的...

我讀能力（16）命令就是這樣：

scsi_read_capacity.cmdblk[0]=0x9e; 
scsi_read_capacity.cmdblk[13]=32; 

開行的其餘均爲0！

這裏是代碼：

#include <stdio.h> 
#include <sys/ioctl.h> 
#include <scsi/sg.h> 


/* global struct to store return data from a scsi cmd*/ 

typedef struct SCSI_data { 
    unsigned char data[1024]; 

    unsigned char raw_sens[252]; 
    unsigned char sense_key; 
    unsigned char additional_sense_code; 
    unsigned char additional_sense_qualifier; 
    unsigned char additional_sense_length; 

    unsigned char sense_data_descriptors[10][244]; 

    int    result; 
} SCSI_data; 



/* global struct to store return data from a scsi cmd*/ 

typedef struct SCSI_cmd { 
    int    sg_fd; 
    unsigned char cmdblk[32]; 
    int    cmdblklength; 
    int    allocation_length; 
    int    xfer; 
    int    timeout; 

} SCSI_cmd; 


SCSI_data send_scsicmd(SCSI_cmd cmdobject) { 
    int k;; 

    unsigned char inqBuff[cmdobject.allocation_length]; 
    unsigned char sense_buffer[252]; 

    SCSI_data output_data; 
    sg_io_hdr_t io_hdr; 

    /* Prepare INQUIRY command */ 
    memset(&io_hdr, 0, sizeof(sg_io_hdr_t)); 
    io_hdr.interface_id = 'S'; 
    io_hdr.cmd_len = cmdobject.cmdblklength; 
    io_hdr.mx_sb_len = sizeof(sense_buffer); 
    io_hdr.dxfer_direction = cmdobject.xfer; 
    io_hdr.dxfer_len = cmdobject.allocation_length; 
    io_hdr.dxferp = inqBuff; 
    io_hdr.cmdp = cmdobject.cmdblk; 
    io_hdr.sbp = sense_buffer; 
    io_hdr.timeout = cmdobject.timeout; 

    if (ioctl(cmdobject.sg_fd, SG_IO, &io_hdr) < 0) { 
     output_data.result=2; 
     return output_data; 
    } 

    /* now for the error processing */ 
    if ((io_hdr.info & SG_INFO_OK_MASK) != SG_INFO_OK) { 
     output_data.result=1; 
     if (io_hdr.sb_len_wr > 0) { 
      printf("INQUIRY sense data: "); 
      for (k = 0; k < io_hdr.sb_len_wr; ++k) { 
       if ((k > 0) && (0 == (k % 10))) 
        printf("\n "); 
       printf("0x%02x ", sense_buffer[k]); 
      } 
      printf("\n"); 
     } 

     if (io_hdr.masked_status) 
      printf("INQUIRY SCSI status=0x%x\n", io_hdr.status); 

     if (io_hdr.host_status) 
      printf("INQUIRY host_status=0x%x\n", io_hdr.host_status); 

     if (io_hdr.driver_status) 
      printf("INQUIRY driver_status=0x%x\n", io_hdr.driver_status); 
    } 

    else { /* assume INQUIRY response is present */ 
     output_data.result=0; 
     for (k=0;k<cmdobject.allocation_length;k++) { 
      output_data.data[k]=inqBuff[k]; 
     } 
    } 
    return output_data; 
} 


int main(int argc, char * argv[]) { 

    FILE *driveptr=fopen(argv[1], "r"); 

    int i; 

    SCSI_data scsi_data_read_capacity; 

    SCSI_cmd scsi_read_capacity; 


    scsi_read_capacity.sg_fd=fileno(driveptr); 
    scsi_read_capacity.cmdblk[0]=0x9e; 
    scsi_read_capacity.cmdblk[13]=32; 
    scsi_read_capacity.cmdblklength=16; 
    scsi_read_capacity.xfer=SG_DXFER_FROM_DEV; 
    scsi_read_capacity.allocation_length=32; 
    scsi_read_capacity.timeout=1000; 

    scsi_data_read_capacity=send_scsicmd(scsi_read_capacity); 

    if (scsi_data_read_capacity.result==0) { 
     printf(" capacity in blocks: %02x%02x%02x%02x%02x%02x%02x%02x\n", 
      scsi_data_read_capacity.data[0], 
      scsi_data_read_capacity.data[1], 
      scsi_data_read_capacity.data[2], 
      scsi_data_read_capacity.data[3], 
      scsi_data_read_capacity.data[4], 
      scsi_data_read_capacity.data[5], 
      scsi_data_read_capacity.data[6], 
      scsi_data_read_capacity.data[7]); 

     printf("    blocksize: %02x%02x%02x%02x\n", 
      scsi_data_read_capacity.data[8], 
      scsi_data_read_capacity.data[9], 
      scsi_data_read_capacity.data[10], 
      scsi_data_read_capacity.data[11]); 

    } 

    fclose(driveptr); 

    return 0; 
} 

Answer 1

我剛剛一個小問題。我的CDB錯了！

我不得不使用這樣的：

scsi_read_capacity.cmdblk[0]=0x9E; 
scsi_read_capacity.cmdblk[1]=0x10; 
scsi_read_capacity.cmdblk[13]=32; 

第二個字節必須是等於0x10的，這是因爲SCSI CMD 0x9E是接受在其中限定了第二個字節的參數服務動作命令其行爲！