问用Libusb 1.0.25仿真USBHID流量
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Stack Overflow用户

提问于 2022-03-30 09:45:53

回答 1查看 166关注 0票数 2

我目前正在尝试模拟使用libusb发送到/从HID设备发送的通信量。使用wireshark和USBPcap对流量进行嗅探。我通过请求描述符和设置配置等来模拟第一个数据包。但是此时，主机根据日志发送一个set空闲请求、get描述符hid报告，最后发送一堆set报告。，libusb中的哪些功能对应于这些数据包？ AFAIK，set报告基本上是主机向设备传输某种设置。我想我可以复制数据包数据并发送完全相同的报告？此外，是否有一种方法可以准确地查看数据在set报表数据包中的作用？我需要知道如何妥善安排这件事。

这就是我想要模仿的数据包：

1   0.000000    host    2.41.0  USB 36  GET DESCRIPTOR Request DEVICE
2   0.000174    2.41.0  host    USB 46  GET DESCRIPTOR Response DEVICE
3   0.000208    host    2.41.0  USB 36  GET DESCRIPTOR Request CONFIGURATION
4   0.000291    2.41.0  host    USB 37  GET DESCRIPTOR Response CONFIGURATION
5   0.000304    host    2.41.0  USB 36  GET DESCRIPTOR Request CONFIGURATION
6   0.000395    2.41.0  host    USB 62  GET DESCRIPTOR Response CONFIGURATION
7   0.000411    host    2.41.0  USB 36  SET CONFIGURATION Request
8   0.001150    2.41.0  host    USB 28  SET CONFIGURATION Response
9   0.001167    host    2.41.0  USBHID  36  SET_IDLE Request
10  0.001239    2.41.0  host    USBHID  28  SET_IDLE Response
11  0.001386    host    2.41.0  USBHID  36  GET DESCRIPTOR Request HID Report
12  0.001462    2.41.0  host    USBHID  104 GET DESCRIPTOR Response HID Report
13  0.002620    host    2.41.1  USB 27  URB_INTERRUPT in
14  0.002645    host    2.41.1  USB 27  URB_INTERRUPT in
15  6.085037    2.41.1  host    USB 27  URB_INTERRUPT in
16  6.085090    2.41.1  host    USB 27  URB_INTERRUPT in
17  18.467828   host    2.41.0  USBHID  36  SET_IDLE Request
18  18.467993   2.41.0  host    USBHID  28  SET_IDLE Response
19  18.468086   host    2.41.1  USB 27  URB_INTERRUPT in
20  18.468114   host    2.41.1  USB 27  URB_INTERRUPT in
21  18.468385   host    2.41.0  USB 36  GET DESCRIPTOR Request STRING
22  18.468537   2.41.0  host    USB 86  GET DESCRIPTOR Response STRING
23  18.468595   host    2.41.0  USB 36  GET DESCRIPTOR Request STRING
24  18.468801   2.41.0  host    USB 60  GET DESCRIPTOR Response STRING
25  18.475044   host    2.41.0  USBHID  53  SET_REPORT Request
26  18.475273   2.41.0  host    USBHID  28  SET_REPORT Response
27  18.475834   host    2.41.0  USBHID  1061    SET_REPORT Request
28  18.476102   2.41.0  host    USBHID  28  SET_REPORT Response
29  18.476571   host    2.41.0  USBHID  1061    SET_REPORT Request
30  18.476849   2.41.0  host    USBHID  28  SET_REPORT Response
31  18.477280   host    2.41.0  USBHID  1061    SET_REPORT Request
32  18.477565   2.41.0  host    USBHID  28  SET_REPORT Response
33  18.478085   host    2.41.0  USBHID  1061    SET_REPORT Request
34  18.478329   2.41.0  host    USBHID  28  SET_REPORT Response
35  18.478700   host    2.41.0  USBHID  1061    SET_REPORT Request

我假设我需要声明接口并设置端点。但是我很难理解如何将系统设置为hid类，如何正确设置中断和轮询等等。此时，我有了配置描述符、设备描述符和设备句柄。

#include <stdio.h>
#include "libusb.h"
#include <unistd.h>
#include <time.h>

static void print_devs(libusb_device **devs) //Taken from examples provided with libusb. Not used at this time
{
    libusb_device *dev;
    int i = 0, j = 0;
    uint8_t path[8]; 

    while ((dev = devs[i++]) != NULL) {
        struct libusb_device_descriptor desc;
        int r = libusb_get_device_descriptor(dev, &desc);
        if (r < 0) {
            fprintf(stderr, "failed to get device descriptor");
            return;
        }

        printf("%04x:%04x (bus %d, device %d)",
            desc.idVendor, desc.idProduct,
            libusb_get_bus_number(dev), libusb_get_device_address(dev));

        r = libusb_get_port_numbers(dev, path, sizeof(path));
        if (r > 0) {
            printf(" path: %d", path[0]);
            for (j = 1; j < r; j++)
                printf(".%d", path[j]);
        }
        printf("\n");
    }
}

int port_open (libusb_device* dev, libusb_device_handle** dev_handle){ //Homebrew func. Retries after failed libusb_open
    int count = 0;
    int err = 0;
    printf("Attempting to open port...\n");
    while (1){
        printf(".\n");
        err = libusb_open(dev, &dev_handle); //Attempts to open port
        if (err == 0){
            break;
        }
        if(count>TIMEOUT){      //5s without the port opening and it will throw error
            printf(libusb_error_name(err));
            return -1;
        }
        count++;
        delay(1);
    }
    return 0;

}


static int target_find(libusb_device *dev){ //Check for device. Libusb already had this but it was done before I saw it.
    struct libusb_device_descriptor my_dev;
    libusb_get_device_descriptor(dev,&my_dev);
    if ((my_dev.idVendor == VENDOR) && (my_dev.idProduct == PRODUCT)){
        return 1;
    }
    return 0;
}


int main(void)
{   
    
    int r;
    int err = 0;
    err = libusb_init(NULL);
    if (err != 0) {
        printf("LIBUSB ERROR: Could not initialize\n");                                                                                                                                                                                                                     
        return -1;
    }
    libusb_device **list;
    libusb_device *found = NULL;


    while(1){   //Finds device and opens port
        ssize_t cnt = libusb_get_device_list(NULL, &list);
        ssize_t i = 0;
        err = 0;
        if (cnt < 0){
            printf("USB ERROR: Could not fetch device list\n");
            return -1;
        }
        for (i = 0; i < cnt; i++) {
            libusb_device *device = list[i];
            if (target_find(device)) {
                found = device;
                break;
            }
        }
        
        if (found) {
            printf("Port found!\n");
            struct libusb_device_descriptor desc;
            struct libusb_config_descriptor config;
            err = libusb_get_device_descriptor(found,&desc);
            if (err){
                printf(libusb_error_name(err));
                return -1;
            }
            err = libusb_get_config_descriptor(found,0,&config);
            if (err){
                printf(libusb_error_name(err));
                return -1;
            }

            libusb_device_handle *handle;
            err = port_open(found, &handle);
            if (err){
                printf("\n Timeout ERROR: Could not open port\n");
                return -1;
            }
            break;
        }
        libusb_free_device_list(list, 1); //Free device list so I can refresh. Unclear if this is needed though.
    }
    
    err = libusb_set_configuration(found, 0x1); //Set config 1 for device, should contain 1 interface with two endpoints. I think.
        //The rest here I guess???
   
    return 0;
}