Question

使用Windows我可以使用以下简化代码轻松与USB设备通信：

DWORD dwJunk;    // discard results from DeviceIOControl()
int   iReply;
char  cBuffer[100];
// cBuffer is initialized here.
HANDLE hDevice; // handle to the drive to be examined 
CString sDrive = _T(\\\\.\\H:); // drive H: for this test
hDevice = CreateFile(sDrive,            // drive to open
   GENERIC_READ | GENERIC_WRITE,        // read and write access to the drive
   FILE_SHARE_READ | FILE_SHARE_WRITE,  // share mode           
   NULL,                                // default security attributes
   OPEN_EXISTING,                       // disposition
   0,                                   // file attributes
   NULL);                               // do not copy file attributes

iReply = DeviceIoControl(hDevice, IOCTL_SCSI_PASS_THROUGH_DIRECT, &cBuffer, sizeof(cBuffer), &cBuffer, sizeof(cBuffer), &dwJunk, (LPOVERLAPPED)NULL);

我正在尝试在linux中做同样的事情，但是无法找出ioctrl（）参数，或者更好地放置结构。我们非常感谢代码片段。感谢。

Answer 1

不幸的是，我使用您的链接修改的代码没有返回任何结果。这是我使用的剥离代码。 ioctl（）返回时没有错误：

#define DEF_TIMEOUT 5000 // 5 seconds
char cDiskName[] = "/dev/sg3";
int fd = open(cDiskName, O_RDWR);
if (fd < 0)
{
  printf("Open error: %s, errno=%d (%s)\n", cDiskName, errno, strerror(errno));
  return 1;
}

unsigned char turCmbBlk[] = {0x00, 0, 0, 0, 0, 0};
struct sg_io_hdr io_hdr;

unsigned char cIOBuffer[100];

// buffer initialization code omitted

memset(&io_hdr, 0, sizeof(struct sg_io_hdr));
io_hdr.interface_id = 'S';
io_hdr.cmd_len = sizeof(turCmbBlk);
io_hdr.mx_sb_len = sizeof(cIOBuffer);
io_hdr.dxfer_direction = SG_DXFER_NONE;
io_hdr.cmdp = turCmbBlk;
io_hdr.sbp = cIOBuffer;
io_hdr.timeout = DEF_TIMEOUT;
if (ioctl(fd, SG_IO, &io_hdr) < 0)
{
  printf("ioctl error: errno=%d (%s)\n", errno, strerror(errno));
}

// Code returned here without any errors but cIOBuffer remains unchanged.

也许电话需要不同的请求代码？

Answer 2

以下是更多文档：

Notes on Linux's SG driver version 2.1.36
SCSI编程，page 8 （handle_SCSI_cmd功能），page 9，page 11 （例子）以及其他一些
Generic SCSI Target Subsystem for Linux

Answer 3

见这里：

#include <sys/ioctl.h>

int ioctl(int d, int request, ...);

<强>参数：

Filedescriptor （必须打开！）
请求代码号码（取决于设备）
无内存指针到内存（进入/来自驱动程序）

示例

#include <stdio.h> #include <fcntl.h> #include <errno.h> #include <sys/ioctl.h> #include <linux/usbdevice_fs.h> void main(int argc, char **argv) { const char *filename; int fd; filename = argv[1]; fd = open(filename, O_WRONLY); ioctl(fd, USBDEVFS_RESET, 0); close(fd); return; }

<强>文档

ioctl(2) - Linux man page

IOCTL(2)

Generic I/O Control operations (GNU libc)

The ioctl() Requests

usb.c （可能对你有帮助的例子）

Linux / Unix Command: ioctl

How to Reset USB Device in Linux （示例）

An example Program with IOCTL

修改

#define BUFF_SIZE 100 // - Buffersize #define DEF_TIMEOUT 5000 // 5 seconds char cDiskName[] = "/dev/sg3"; int fd = open(cDiskName, O_RDWR); if (fd < 0) { printf("Open error: %s, errno=%d (%s)\n", cDiskName, errno, strerror(errno)); return 1; } unsigned char turCmbBlk[] = {0x00, 0, 0, 0, 0, 0}; struct sg_io_hdr *p = (struct sg_io_hdr *) malloc(sizeof(struct sg_io_hdr)); // - dynamic memory allocation - free() required somewhere unsigned char cIOBuffer[BUFF_SIZE]; unsigned char replyBuffer[BUFF_SIZE]; // - dxfer buffer // buffer initialization code omitted memset(p, 0, sizeof(struct sg_io_hdr)); p->interface_id = 'S'; p->cmd_len = sizeof(turCmbBlk); p->mx_sb_len = BUFF_SIZE; p->dxfer_direction = SG_DXFER_NONE; p->cmdp = turCmbBlk; p->sbp = cIOBuffer; p->timeout = DEF_TIMEOUT; p->flags = SG_FLAG_DIRECT_IO; // - Does this help? p->dxferp = replyBuffer; // - Set dxferp buffer - (A) p->dxfer_len = BUFF_SIZE; // - buffersize if (ioctl(fd, SG_IO, p) < 0) { printf("ioctl error: errno=%d (%s)\n", errno, strerror(errno)); } // Code returned here without any errors but cIOBuffer remains unchanged.

注意（A）：请尝试设置您在此处使用的输入/输出缓冲区。

<强>文档

SCSI Generic HOWTO, SG_IO_HDR_T

Tour the Linux generic SCSI driver

ioctl使用SCSI传递

3 个答案: