libusb_fill_bulk_transfer
void libusb_fill_bulk_transfer(struct libusb_transfer *transfer, libusb_device_handle *devh, uint8_t endpoint, uint8_t *buf, int length, libusb_transfer_cb_fn callback, void *user_data, uint32_t timeout);
libusb_fill_bulk_transfer(transfer, dev_handle, endpoint, buffer,