From 84801d80af4cb9f2ca240441a690a720d65a4711 Mon Sep 17 00:00:00 2001 From: Eliyahu Stern Date: Sat, 24 Dec 2022 21:45:35 +0200 Subject: Guess current mode based on available configurations and interfaces. Switch mode only if guess is different than desired mode. --- src/usb.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 73 insertions(+), 15 deletions(-) (limited to 'src') diff --git a/src/usb.c b/src/usb.c index ee64fa5..c98b58a 100644 --- a/src/usb.c +++ b/src/usb.c @@ -390,6 +390,71 @@ static struct usb_device* find_device(int bus, int address) return NULL; } +/// @brief guess the current mode +/// @param dev +/// @param usbdev +/// @param handle +/// @return 0 - undetermined, 1 - initial, 2 - valeria, 3 - cdc_ncm +static int guess_mode(struct libusb_device* dev, struct usb_device *usbdev) +{ + int res, j; + int has_valeria = 0, has_cdc_ncm = 0, has_usbmux = 0; + struct libusb_device_descriptor devdesc = usbdev->devdesc; + struct libusb_config_descriptor *config; + int bus = usbdev->bus; + int address = usbdev->address; + + if(devdesc.bNumConfigurations <= 4) { + // Assume this is initial mode + return 1; + } + + if(devdesc.bNumConfigurations != 5) { + // No known modes with more then 5 configurations + return 0; + } + + if((res = libusb_get_config_descriptor_by_value(dev, 5, &config)) != 0) { + usbmuxd_log(LL_NOTICE, "Could not get configuration 5 descriptor for device %i-%i: %s", bus, address, libusb_error_name(res)); + return 0; + } + + // Require both usbmux and one of the other interfaces to determine this is a valid configuration + for(j = 0 ; j < config->bNumInterfaces ; j++) { + const struct libusb_interface_descriptor *intf = &config->interface[j].altsetting[0]; + if(intf->bInterfaceClass == INTERFACE_CLASS && + intf->bInterfaceSubClass == 42 && + intf->bInterfaceProtocol == 255) { + has_valeria = 1; + } + // https://github.com/torvalds/linux/blob/72a85e2b0a1e1e6fb4ee51ae902730212b2de25c/include/uapi/linux/usb/cdc.h#L22 + // 2 for Communication class, 0xd for CDC NCM subclass + if(intf->bInterfaceClass == 2 && + intf->bInterfaceSubClass == 0xd) { + has_cdc_ncm = 1; + } + if(intf->bInterfaceClass == INTERFACE_CLASS && + intf->bInterfaceSubClass == INTERFACE_SUBCLASS && + intf->bInterfaceProtocol == INTERFACE_PROTOCOL) { + has_usbmux = 1; + } + } + + libusb_free_config_descriptor(config); + + if(has_valeria && has_usbmux) { + usbmuxd_log(LL_NOTICE, "Found Valeria and Apple USB Multiplexor in device %i-%i configuration 5", bus, address); + return 2; + } + + if(has_cdc_ncm && has_usbmux) { + usbmuxd_log(LL_NOTICE, "Found CDC-NCM and Apple USB Multiplexor in device %i-%i configuration 5", bus, address); + return 3; + } + + return 0; +} + /// @brief Finds and sets the valid configuration, interface and endpoints on the usb_device static int set_valid_configuration(struct libusb_device* dev, struct usb_device *usbdev, struct libusb_device_handle *handle) { @@ -625,25 +690,19 @@ static void get_mode_cb(struct libusb_transfer* transfer) unsigned char *data = libusb_control_transfer_get_data(transfer); - char* desired_mode = getenv(ENV_DEVICE_MODE); - if(!desired_mode) { - context->wIndex = 0x1; - } - else if(!strncmp(desired_mode, "2", 1)) { - context->wIndex = 0x2; - } - else if(!strncmp(desired_mode, "3", 1)) { - context->wIndex = 0x3; - } + int desired_mode = atoi(getenv(ENV_DEVICE_MODE)); + int guessed_mode = guess_mode(context->dev, dev); + // Response is 3:3:3:0 for initial mode, 5:3:3:0 otherwise. - // In later commit, should infer the mode from available configurations and interfaces. usbmuxd_log(LL_INFO, "Received response %i:%i:%i:%i for get_mode request for device %i-%i", data[0], data[1], data[2], data[3], context->bus, context->address); - if(context->wIndex > 1 && data[0] == 3 && data[1] == 3 && data[2] == 3 && data[3] == 0) { - // 3:3:3:0 means the initial mode + if(desired_mode >= 1 && desired_mode <= 3 && + guessed_mode > 0 && // do not switch mode if guess failed + guessed_mode != desired_mode) { usbmuxd_log(LL_WARNING, "Switching device %i-%i mode to %i", context->bus, context->address, context->wIndex); context->bRequest = APPLE_VEND_SPECIFIC_SET_MODE; context->wValue = 0; + context->wIndex = desired_mode; context->wLength = 1; if((res = submit_vendor_specific(transfer->dev_handle, context, switch_mode_cb)) != 0) { @@ -653,8 +712,7 @@ static void get_mode_cb(struct libusb_transfer* transfer) } } else { - // in other modes, usually 5:3:3:0 (but in any other unexpected case as well), complete init: - usbmuxd_log(LL_WARNING, "Skipping switch device %i-%i mode", context->bus, context->address); + usbmuxd_log(LL_WARNING, "Skipping switch device %i-%i mode from %i to %i", context->bus, context->address, guessed_mode, desired_mode); device_complete_initialization(context, transfer->dev_handle); free(context); } -- cgit v1.1-32-gdbae