hid_enumerate_full.c

struct hid_device_info HID_API_EXPORT * HID_API_CALL hid_enumerate(unsigned short vendor_id, unsigned short product_id)
{
    BOOL res;
    struct hid_device_info *root = NULL; /* return object */
    struct hid_device_info *cur_dev = NULL;

    /* Windows objects for interacting with the driver. */
    GUID InterfaceClassGuid = {0x4d1e55b2, 0xf16f, 0x11cf, {0x88, 0xcb, 0x00, 0x11, 0x11, 0x00, 0x00, 0x30} };
    SP_DEVINFO_DATA devinfo_data;
    SP_DEVICE_INTERFACE_DATA device_interface_data;
    SP_DEVICE_INTERFACE_DETAIL_DATA_A *device_interface_detail_data = NULL;
    HDEVINFO device_info_set = INVALID_HANDLE_VALUE;
    int device_index = 0;
    int i;

    if (hid_init() < 0)
        return NULL;

    /* Initialize the Windows objects. */
    memset(&devinfo_data, 0x0, sizeof(devinfo_data));
    devinfo_data.cbSize = sizeof(SP_DEVINFO_DATA);
    device_interface_data.cbSize = sizeof(SP_DEVICE_INTERFACE_DATA);

    /* Get information for all the devices belonging to the HID class. */
    device_info_set = SetupDiGetClassDevsA(&InterfaceClassGuid, NULL, NULL, DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);
    
    /* Iterate over each device in the HID class, looking for the right one. */
    
    for (;;) {
        printf("Iterating over device [%d]\n", device_index);
        HANDLE write_handle = INVALID_HANDLE_VALUE;
        DWORD required_size = 0;
        HIDD_ATTRIBUTES attrib;

        res = SetupDiEnumDeviceInterfaces(device_info_set,
            NULL,
            &InterfaceClassGuid,
            device_index,
            &device_interface_data);
        
        if (!res) {
            /* A return of FALSE from this function means that
               there are no more devices. */
            puts("Finished, no more devices\n");
            break;
        }

        /* Call with 0-sized detail size, and let the function
           tell us how long the detail struct needs to be. The
           size is put in &required_size. */
        res = SetupDiGetDeviceInterfaceDetailA(device_info_set,
            &device_interface_data,
            NULL,
            0,
            &required_size,
            NULL);

        /* Allocate a long enough structure for device_interface_detail_data. */
        device_interface_detail_data = (SP_DEVICE_INTERFACE_DETAIL_DATA_A*) malloc(required_size);
        device_interface_detail_data->cbSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA_A);

        /* Get the detailed data for this device. The detail data gives us
           the device path for this device, which is then passed into
           CreateFile() to get a handle to the device. */
        res = SetupDiGetDeviceInterfaceDetailA(device_info_set,
            &device_interface_data,
            device_interface_detail_data,
            required_size,
            NULL,
            NULL);

        if (!res) {
            /* register_error(dev, "Unable to call SetupDiGetDeviceInterfaceDetail");
               Continue to the next device. */
            printf("Unable to call SetupDiGetDeviceInterfaceDetail");
            goto cont;
        }
        printf("device interface detail: %s\n", device_interface_detail_data->DevicePath);

        /* Make sure this device is of Setup Class "HIDClass" and has a
           driver bound to it. */
#define ENABLE_HIDCLASS_CHECK 1
#define ENABLE_FOR_LOOP 1
#if ENABLE_FOR_LOOP
        for (i = 0; ; i++) {
#else
        i = device_index;
#endif
            char driver_name[256];

            /* Populate devinfo_data. This function will return failure
               when there are no more interfaces left. */
            res = SetupDiEnumDeviceInfo(device_info_set, i, &devinfo_data);
            if (!res)
            {
                printf("failure on SetupDiEnumDeviceInfo()!\n");  
                goto cont;
            }
            printf("Getting driver of i: [%d] Instance: [%d] guid: [%d]", i, devinfo_data.DevInst, devinfo_data.ClassGuid); 

            res = SetupDiGetDeviceRegistryPropertyA(device_info_set, &devinfo_data,
                           SPDRP_CLASS, NULL, (PBYTE)driver_name, sizeof(driver_name), NULL);
            if (!res)
            {
                printf("failure on SetupDiGetDeviceRegistryPropertyA()!\n");
                goto cont;
            }

            printf(" Driver: %s\n", driver_name);

            #if ENABLE_HIDCLASS_CHECK
                #if ENABLE_FOR_LOOP
                    if (strcmp(driver_name, "HIDClass") == 0) {
                        res = SetupDiGetDeviceRegistryPropertyA(device_info_set, &devinfo_data,
                                   SPDRP_DRIVER, NULL, (PBYTE)driver_name, sizeof(driver_name), NULL);
                        if (res)
                            break;
                    }
                #else
                    if (strcmp(driver_name, "HIDClass") != 0) {
                        goto cont;
                    }
                #endif
            #endif
#if ENABLE_FOR_LOOP
        }
#endif
        //wprintf(L"HandleName: %s\n", device_interface_detail_data->DevicePath);

        /* Open a handle to the device */
        write_handle = open_device(device_interface_detail_data->DevicePath, TRUE);

        /* Check validity of write_handle. */
        if (write_handle == INVALID_HANDLE_VALUE) {
            /* Unable to open the device. */
            //register_error(dev, "CreateFile");
            goto cont_close;
        }        


        /* Get the Vendor ID and Product ID for this device. */
        attrib.Size = sizeof(HIDD_ATTRIBUTES);
        HidD_GetAttributes(write_handle, &attrib);
        wprintf(L"Product/Vendor: %x %x\n", attrib.ProductID, attrib.VendorID);

        /* Check the VID/PID to see if we should add this
           device to the enumeration list. */
        if ((vendor_id == 0x0 || attrib.VendorID == vendor_id) &&
            (product_id == 0x0 || attrib.ProductID == product_id)) {

            #define WSTR_LEN 512
            const char *str;
            struct hid_device_info *tmp;
            PHIDP_PREPARSED_DATA pp_data = NULL;
            HIDP_CAPS caps;
            BOOLEAN res;
            NTSTATUS nt_res;
            wchar_t wstr[WSTR_LEN]; /* TODO: Determine Size */
            size_t len;

            /* VID/PID match. Create the record. */
            tmp = (struct hid_device_info*) calloc(1, sizeof(struct hid_device_info));
            if (cur_dev) {
                cur_dev->next = tmp;
            }
            else {
                root = tmp;
            }
            cur_dev = tmp;

            /* Get the Usage Page and Usage for this device. */
            res = HidD_GetPreparsedData(write_handle, &pp_data);
            if (res) {
                nt_res = HidP_GetCaps(pp_data, &caps);
                if (nt_res == HIDP_STATUS_SUCCESS) {
                    cur_dev->usage_page = caps.UsagePage;
                    cur_dev->usage = caps.Usage;
                }

                HidD_FreePreparsedData(pp_data);
            }
            
            /* Fill out the record */
            cur_dev->next = NULL;
            str = device_interface_detail_data->DevicePath;
            if (str) {
                len = strlen(str);
                cur_dev->path = (char*) calloc(len+1, sizeof(char));
                strncpy(cur_dev->path, str, len+1);
                cur_dev->path[len] = '\0';
            }
            else
                cur_dev->path = NULL;

            /* Serial Number */
            res = HidD_GetSerialNumberString(write_handle, wstr, sizeof(wstr));
            wstr[WSTR_LEN-1] = 0x0000;
            if (res) {
                cur_dev->serial_number = _wcsdup(wstr);
            }

            /* Manufacturer String */
            res = HidD_GetManufacturerString(write_handle, wstr, sizeof(wstr));
            wstr[WSTR_LEN-1] = 0x0000;
            if (res) {
                cur_dev->manufacturer_string = _wcsdup(wstr);
            }

            /* Product String */
            res = HidD_GetProductString(write_handle, wstr, sizeof(wstr));
            wstr[WSTR_LEN-1] = 0x0000;
            if (res) {
                cur_dev->product_string = _wcsdup(wstr);
            }

            /* VID/PID */
            cur_dev->vendor_id = attrib.VendorID;
            cur_dev->product_id = attrib.ProductID;

            /* Release Number */
            cur_dev->release_number = attrib.VersionNumber;

            /* Interface Number. It can sometimes be parsed out of the path
               on Windows if a device has multiple interfaces. See
               http://msdn.microsoft.com/en-us/windows/hardware/gg487473 or
               search for "Hardware IDs for HID Devices" at MSDN. If it's not
               in the path, it's set to -1. */
            cur_dev->interface_number = -1;
            if (cur_dev->path) {
                char *interface_component = strstr(cur_dev->path, "&mi_");
                if (interface_component) {
                    char *hex_str = interface_component + 4;
                    char *endptr = NULL;
                    cur_dev->interface_number = strtol(hex_str, &endptr, 16);
                    if (endptr == hex_str) {
                        /* The parsing failed. Set interface_number to -1. */
                        cur_dev->interface_number = -1;
                    }
                }
            }
        }

cont_close:
        CloseHandle(write_handle);
cont:
        /* We no longer need the detail data. It can be freed */
        free(device_interface_detail_data);

        device_index++;

    }

    /* Close the device information handle. */
    SetupDiDestroyDeviceInfoList(device_info_set);

    return root;

}