Index: uspace/lib/usbvirt/stdreq.c
===================================================================
--- uspace/lib/usbvirt/stdreq.c	(revision 49718128accdeacf6fe042496fd599feb593f4b2)
+++ uspace/lib/usbvirt/stdreq.c	(revision 49718128accdeacf6fe042496fd599feb593f4b2)
@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) 2010 Vojtech Horky
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libusbvirt usb
+ * @{
+ */
+/** @file
+ * @brief Preprocessing of standard device requests.
+ */
+#include <errno.h>
+#include <usb/devreq.h>
+
+#include "private.h"
+
+/*
+ * All sub handlers must return EFORWARD to inform the caller that
+ * they were not able to process the request (yes, it is abuse of
+ * this error code but such error code shall not collide with anything
+ * else in this context).
+ */
+ 
+static int handle_get_descriptor(uint8_t type, uint8_t index, uint16_t language,
+    uint16_t length)
+{
+	/* 
+	 * Standard device descriptor.
+	 */
+	if ((type == USB_DESCTYPE_DEVICE) && (index == 0)) {
+		if (device->standard_descriptor) {
+			return device->send_data(device, 0,
+			    device->standard_descriptor,
+			    device->standard_descriptor->length);
+		} else {
+			return EFORWARD;
+		}
+	}
+	
+	return EFORWARD;
+}
+
+static int handle_set_address(uint16_t new_address,
+    uint16_t zero1, uint16_t zero2)
+{
+	if ((zero1 != 0) || (zero2 != 0)) {
+		return EINVAL;
+	}
+	
+	if (new_address > 127) {
+		return EINVAL;
+	}
+	
+	/*
+	 * TODO: inform the HC that device has new address assigned.
+	 */
+	return EOK;
+}
+
+int handle_std_request(usb_direction_t direction, int recipient,
+    uint16_t request, uint16_t value, uint16_t index, uint16_t length,
+    uint8_t *remaining_data)
+{
+	int rc;
+	
+	switch (request) {
+		case USB_DEVREQ_GET_DESCRIPTOR:
+			rc = handle_get_descriptor(value >> 8, (uint8_t) value,
+			    index, length);
+			break;
+		
+		case USB_DEVREQ_SET_ADDRESS:
+			rc = handle_set_address(value, index, length);
+			break;
+		
+		default:
+			rc = EFORWARD;
+			break;
+	}
+	
+	/*
+	 * We preprocessed all we could.
+	 * If it was not enough, pass the request to the actual driver.
+	 */
+	if (rc == EFORWARD) {
+		if (DEVICE_HAS_OP(device, on_devreq_std)) {
+			return device->ops->on_devreq_std(device, direction,
+			    recipient,
+			    request, value, index,
+			    length, remaining_data);
+		}
+	}
+	
+	return EOK;
+}
+
+/**
+ * @}
+ */