我正在尝试使用libusb和C编程从Windows上通过USB连接的pendrive读取数据。我可以列出我的USB连接，但我无法连接到一个，也无法将数据从USB传输到我的计算机。
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "libusb.h"
#define BULK_EP_OUT 0x63
#define BULK_EP_IN 0x08
int interface_ref = 0;
int alt_interface, interface_number;
int print_configuration(struct libusb_device_handle *hDevice, struct libusb_config_descriptor *config)
{
char *data;
int index;
data = (char *)malloc(512);
memset(data, 0, 512);
index = config->iConfiguration;
libusb_get_string_descriptor_ascii(hDevice, index, data, 512);
printf("nInterface Descriptors: ");
printf("ntNumber of Interfaces: %d", config->bNumInterfaces);
printf("ntLength: %d", config->bLength);
printf("ntDesc_Type: %d", config->bDescriptorType);
printf("ntConfig_index: %d", config->iConfiguration);
printf("ntTotal length: %lu", config->wTotalLength);
printf("ntConfiguration Value: %d", config->bConfigurationValue);
printf("ntConfiguration Attributes: %d", config->bmAttributes);
printf("ntMaxPower(mA): %dn", config->MaxPower);
free(data);
data = NULL;
return 0;
}
struct libusb_endpoint_descriptor* active_config(struct libusb_device *dev, struct libusb_device_handle *handle)
{
struct libusb_device_handle *hDevice_req;
struct libusb_config_descriptor *config;
struct libusb_endpoint_descriptor *endpoint;
int altsetting_index, interface_index=0, ret_active;
int i, ret_print;
hDevice_req = handle;
ret_active = libusb_get_active_config_descriptor(dev, &config);
ret_print = print_configuration(hDevice_req, config);
for (interface_index=0;interface_index<config->bNumInterfaces;interface_index++)
{
const struct libusb_interface *iface = &config->interface[interface_index];
for (altsetting_index=0; altsetting_index<iface->num_altsetting; altsetting_index++)
{
const struct libusb_interface_descriptor *altsetting = &iface->altsetting[altsetting_index];
int endpoint_index;
for(endpoint_index=0; endpoint_index<altsetting->bNumEndpoints; endpoint_index++)
{
const struct libusb_endpoint_desriptor *ep = &altsetting->endpoint[endpoint_index];
endpoint = ep;
alt_interface = altsetting->bAlternateSetting;
interface_number = altsetting->bInterfaceNumber;
}
printf("nEndPoint Descriptors: ");
printf("ntSize of EndPoint Descriptor: %d", endpoint->bLength);
printf("ntType of Descriptor: %d", endpoint->bDescriptorType);
printf("ntEndpoint Address: 0x0%x", endpoint->bEndpointAddress);
printf("ntMaximum Packet Size: %x", endpoint->wMaxPacketSize);
printf("ntAttributes applied to Endpoint: %d", endpoint->bmAttributes);
printf("ntInterval for Polling for data Tranfer: %dn", endpoint->bInterval);
}
}
libusb_free_config_descriptor(NULL);
return endpoint;
}
int main(void)
{
int r = 1, found1;
struct libusb_device **devs;
struct libusb_device_handle *handle = NULL, *hDevice_expected = NULL;
struct libusb_device *dev, *dev_expected;
struct libusb_device_descriptor desc;
struct libusb_endpoint_descriptor *epdesc;
struct libusb_interface_descriptor *intdesc;
libusb_context *context = NULL;
ssize_t cnt;
int e = 0, config2;
int i = 0, index;
char str1[64], str2[64];
char found = 0;
// Init libusb
r = libusb_init(NULL);
if(r < 0)
{
printf("nFailed to initialise libusbn");
return 1;
}
else
printf("nInit successful!n");
// Get a list of USB devices
cnt = libusb_get_device_list(NULL, &devs);
if (cnt < 0)
{
printf("nThere are no USB devices on the busn");
return -1;
}
printf("nDevice count: %dn-------------------------------n", cnt);
while ((dev = devs[i++]) > 0)
{
r = libusb_get_device_descriptor(dev, &desc);
if (r < 0)
{
printf("Failed to get device descriptorn");
libusb_free_device_list(devs, 1);
libusb_close(handle);
break;
}
e = libusb_open(dev, &handle);
if (e < 0)
{
printf("Error opening devicen");
printf(e);
libusb_free_device_list(devs, 1);
libusb_close(handle);
break;
}
printf("nDevice Descriptors: ");
printf("ntVendor ID: %x", desc.idVendor);
printf("ntProduct ID: %x", desc.idProduct);
printf("ntSerial Number: %x", desc.iSerialNumber);
printf("ntSize of Device Descriptor: %d", desc.bLength);
printf("ntType of Descriptor: %d", desc.bDescriptorType);
printf("ntUSB Specification Release Number: %d", desc.bcdUSB);
printf("ntDevice Release Number: %d", desc.bcdDevice);
printf("ntDevice Class: %d", desc.bDeviceClass);
printf("ntDevice Sub-Class: %d", desc.bDeviceSubClass);
printf("ntDevice Protocol: %d", desc.bDeviceProtocol);
printf("ntMax. Packet Size: %d", desc.bMaxPacketSize0);
printf("ntNumber of Configurations: %dn", desc.bNumConfigurations);
e = libusb_get_string_descriptor_ascii(handle, desc.iManufacturer, (unsigned char*) str1, sizeof(str1));
if (e < 0)
{
libusb_free_device_list(devs, 1);
libusb_close(handle);
break;
}
printf("nManufactured: %s", str1);
e = libusb_get_string_descriptor_ascii(handle, desc.iProduct, (unsigned char*) str2, sizeof(str2));
if(e < 0)
{
libusb_free_device_list(devs, 1);
libusb_close(handle);
break;
}
printf("nProduct: %s", str2);
printf("n----------------------------------------");
if(desc.idVendor == 0x0781 && desc.idProduct == 0x5567)
{
found1 = 1;
break;
}
}//end of while
if (found1 == 0)
{
printf("nDevice NOT foundn");
libusb_free_device_list(devs, 1);
libusb_close(handle);
return 1;
}
else
{
printf("nDevice found");
dev_expected = dev;
hDevice_expected = handle;
}
e = libusb_get_configuration(handle, &config2);
if (e!=0)
{
printf("n***Error in libusb_get_configurationn");
libusb_free_device_list(devs, 1);
libusb_close(handle);
return -1;
}
printf("nConfigured value: %d", config2);
if (config2 != 1)
{
libusb_set_configuration(handle, 1);
if(e!=0)
{
printf("Error in libusb_set_configurationn");
libusb_free_device_list(devs, 1);
libusb_close(handle);
return -1;
}
else
printf("nDevice is in configured state!");
}
libusb_free_device_list(devs, 1);
if(libusb_kernel_driver_active(handle, 0) == 1)
{
printf("nKernel Driver Active");
if(libusb_detach_kernel_driver(handle, 0) == 0)
printf("nKernel Driver Detached!");
else
{
printf("nCouldn't detach kernel driver!n");
libusb_free_device_list(devs, 1);
libusb_close(handle);
return -1;
}
}
e = libusb_claim_interface(handle, 0);
if (e < 0)
{
printf("nCannot Claim Interface");
libusb_free_device_list(devs, 1);
libusb_close(handle);
return -1;
}
else
printf("nClaimed Interfacen");
active_config(dev_expected, hDevice_expected);
char *my_string, *my_string1;
int transferred = 0;
int received = 0;
int length = 0;
int nbytes = 256;
my_string = (char *)malloc(nbytes + 1);
my_string1 = (char *)malloc(nbytes + 1);
memset(my_string, ' ', 64);
memset(my_string1, ' ', 64);
strcpy(my_string, "Prasad Divesd");
length = strlen(my_string);
printf("nTo be sent: %s", my_string);
for(i = 0; i < length; i++)
{
e = libusb_bulk_transfer(handle, BULK_EP_OUT, my_string1, 64, &received, 0); //64: Max Packet Length
if(e == 0)
{
printf("nReceived: ");
printf("%c", my_string1[i]);
_sleep(1);
}
else
{
printf("nError in read! e = %d and received = %dn", e, received);
return -1;
}
}
e = libusb_release_interface(handle, 0);
libusb_close(handle);
libusb_exit(NULL);
printf("n");
return 0;
}
使用libusb:libusb_bulk_transfer()在笔式驱动器上读/写的代码适用于Linux。下面的顺序是分离Linux中的内核驱动程序。
这样做是为了能够将批量传输写入USB大容量存储设备(pendrive)。在Linux中，这是必要的，在Windows中，这并不是因为在Windows中libusb有自己的驱动程序：
if(libusb_kernel_driver_active(handle, 0) == 1)
{
printf("nKernel Driver Active");
if(libusb_detach_kernel_driver(handle, 0) == 0)
printf("nKernel Driver Detached!");
else
{
printf("nCouldn't detach kernel driver!n");
libusb_free_device_list(devs, 1);
libusb_close(handle);
return -1;
}
}
所以你必须至少删除这个代码。
然后注意，Windows上的libusb有一些限制，请参阅https://github.com/libusb/libusb/wiki/Windows.
如果您想调试程序，请使用类似WinDbg的调试器(在WinDbg中查看调用堆栈)和获取堆栈跟踪(Windows调试器：第1部分：WinDbg教程和查看WinDbg中的调用堆栈)
有关USB的更多信息，请参阅NutShell中的USB。
除此之外，你发布的代码应该可以工作(当删除Linux特定的行时，等等)