adb/usb_windows.cpp - android_system_core - Gitiles

 /*
  * Copyright (C) 2007 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #define TRACE_TAG TRACE_USB

 #include "sysdeps.h"

 #include <winsock2.h>  // winsock.h *must* be included before windows.h.
 #include <adb_api.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <usb100.h>
 #include <windows.h>
 #include <winerror.h>

 #include "adb.h"
 #include "transport.h"

 /** Structure usb_handle describes our connection to the usb device via
   AdbWinApi.dll. This structure is returned from usb_open() routine and
   is expected in each subsequent call that is accessing the device.
 */
 struct usb_handle {
   /// Previous entry in the list of opened usb handles
   usb_handle *prev;

   /// Next entry in the list of opened usb handles
   usb_handle *next;

   /// Handle to USB interface
   ADBAPIHANDLE  adb_interface;

   /// Handle to USB read pipe (endpoint)
   ADBAPIHANDLE  adb_read_pipe;

   /// Handle to USB write pipe (endpoint)
   ADBAPIHANDLE  adb_write_pipe;

   /// Interface name
   char*         interface_name;

   /// Mask for determining when to use zero length packets
   unsigned zero_mask;
 };

 /// Class ID assigned to the device by androidusb.sys
 static const GUID usb_class_id = ANDROID_USB_CLASS_ID;

 /// List of opened usb handles
 static usb_handle handle_list = {
   .prev = &handle_list,
   .next = &handle_list,
 };

 /// Locker for the list of opened usb handles
 ADB_MUTEX_DEFINE( usb_lock );

 /// Checks if there is opened usb handle in handle_list for this device.
 int known_device(const char* dev_name);

 /// Checks if there is opened usb handle in handle_list for this device.
 /// usb_lock mutex must be held before calling this routine.
 int known_device_locked(const char* dev_name);

 /// Registers opened usb handle (adds it to handle_list).
 int register_new_device(usb_handle* handle);

 /// Checks if interface (device) matches certain criteria
 int recognized_device(usb_handle* handle);

 /// Enumerates present and available interfaces (devices), opens new ones and
 /// registers usb transport for them.
 void find_devices();

 /// Entry point for thread that polls (every second) for new usb interfaces.
 /// This routine calls find_devices in infinite loop.
 void* device_poll_thread(void* unused);

 /// Initializes this module
 void usb_init();

 /// Cleans up this module
 void usb_cleanup();

 /// Opens usb interface (device) by interface (device) name.
 usb_handle* do_usb_open(const wchar_t* interface_name);

 /// Writes data to the opened usb handle
 int usb_write(usb_handle* handle, const void* data, int len);

 /// Reads data using the opened usb handle
 int usb_read(usb_handle *handle, void* data, int len);

 /// Cleans up opened usb handle
 void usb_cleanup_handle(usb_handle* handle);

 /// Cleans up (but don't close) opened usb handle
 void usb_kick(usb_handle* handle);

 /// Closes opened usb handle
 int usb_close(usb_handle* handle);

 /// Gets interface (device) name for an opened usb handle
 const char *usb_name(usb_handle* handle);

 int known_device_locked(const char* dev_name) {
   usb_handle* usb;

   if (NULL != dev_name) {
     // Iterate through the list looking for the name match.
     for(usb = handle_list.next; usb != &handle_list; usb = usb->next) {
       // In Windows names are not case sensetive!
       if((NULL != usb->interface_name) &&
          (0 == stricmp(usb->interface_name, dev_name))) {
         return 1;
       }
     }
   }

   return 0;
 }

 int known_device(const char* dev_name) {
   int ret = 0;

   if (NULL != dev_name) {
     adb_mutex_lock(&usb_lock);
     ret = known_device_locked(dev_name);
     adb_mutex_unlock(&usb_lock);
   }

   return ret;
 }

 int register_new_device(usb_handle* handle) {
   if (NULL == handle)
     return 0;

   adb_mutex_lock(&usb_lock);

   // Check if device is already in the list
   if (known_device_locked(handle->interface_name)) {
     adb_mutex_unlock(&usb_lock);
     return 0;
   }

   // Not in the list. Add this handle to the list.
   handle->next = &handle_list;
   handle->prev = handle_list.prev;
   handle->prev->next = handle;
   handle->next->prev = handle;

   adb_mutex_unlock(&usb_lock);

   return 1;
 }

 void* device_poll_thread(void* unused) {
   D("Created device thread\n");

   while(1) {
     find_devices();
     adb_sleep_ms(1000);
   }

   return NULL;
 }

 void usb_init() {
   adb_thread_t tid;

   if(adb_thread_create(&tid, device_poll_thread, NULL)) {
     fatal_errno("cannot create input thread");
   }
 }

 void usb_cleanup() {
 }

 usb_handle* do_usb_open(const wchar_t* interface_name) {
   // Allocate our handle
   usb_handle* ret = (usb_handle*)malloc(sizeof(usb_handle));
   if (NULL == ret)
     return NULL;

   // Set linkers back to the handle
   ret->next = ret;
   ret->prev = ret;

   // Create interface.
   ret->adb_interface = AdbCreateInterfaceByName(interface_name);

   if (NULL == ret->adb_interface) {
     free(ret);
     errno = GetLastError();
     return NULL;
   }

   // Open read pipe (endpoint)
   ret->adb_read_pipe =
     AdbOpenDefaultBulkReadEndpoint(ret->adb_interface,
                                    AdbOpenAccessTypeReadWrite,
                                    AdbOpenSharingModeReadWrite);
   if (NULL != ret->adb_read_pipe) {
     // Open write pipe (endpoint)
     ret->adb_write_pipe =
       AdbOpenDefaultBulkWriteEndpoint(ret->adb_interface,
                                       AdbOpenAccessTypeReadWrite,
                                       AdbOpenSharingModeReadWrite);
     if (NULL != ret->adb_write_pipe) {
       // Save interface name
       unsigned long name_len = 0;

       // First get expected name length
       AdbGetInterfaceName(ret->adb_interface,
                           NULL,
                           &name_len,
                           true);
       if (0 != name_len) {
         ret->interface_name = (char*)malloc(name_len);

         if (NULL != ret->interface_name) {
           // Now save the name
           if (AdbGetInterfaceName(ret->adb_interface,
                                   ret->interface_name,
                                   &name_len,
                                   true)) {
             // We're done at this point
             return ret;
           }
         } else {
           SetLastError(ERROR_OUTOFMEMORY);
         }
       }
     }
   }

   // Something went wrong.
   int saved_errno = GetLastError();
   usb_cleanup_handle(ret);
   free(ret);
   SetLastError(saved_errno);

   return NULL;
 }

 int usb_write(usb_handle* handle, const void* data, int len) {
   unsigned long time_out = 5000;
   unsigned long written = 0;
   int ret;

   D("usb_write %d\n", len);
   if (NULL != handle) {
     // Perform write
     ret = AdbWriteEndpointSync(handle->adb_write_pipe,
                                (void*)data,
                                (unsigned long)len,
                                &written,
                                time_out);
     int saved_errno = GetLastError();

     if (ret) {
       // Make sure that we've written what we were asked to write
       D("usb_write got: %ld, expected: %d\n", written, len);
       if (written == (unsigned long)len) {
         if(handle->zero_mask && (len & handle->zero_mask) == 0) {
           // Send a zero length packet
           AdbWriteEndpointSync(handle->adb_write_pipe,
                                (void*)data,
                                0,
                                &written,
                                time_out);
         }
         return 0;
       }
     } else {
       // assume ERROR_INVALID_HANDLE indicates we are disconnected
       if (saved_errno == ERROR_INVALID_HANDLE)
         usb_kick(handle);
     }
     errno = saved_errno;
   } else {
     D("usb_write NULL handle\n");
     SetLastError(ERROR_INVALID_HANDLE);
   }

   D("usb_write failed: %d\n", errno);

   return -1;
 }

 int usb_read(usb_handle *handle, void* data, int len) {
   unsigned long time_out = 0;
   unsigned long read = 0;
   int ret;

   D("usb_read %d\n", len);
   if (NULL != handle) {
     while (len > 0) {
       int xfer = (len > 4096) ? 4096 : len;

       ret = AdbReadEndpointSync(handle->adb_read_pipe,
                                   data,
                                   (unsigned long)xfer,
                                   &read,
                                   time_out);
       int saved_errno = GetLastError();
       D("usb_write got: %ld, expected: %d, errno: %d\n", read, xfer, saved_errno);
       if (ret) {
         data = (char *)data + read;
         len -= read;

         if (len == 0)
           return 0;
       } else {
         // assume ERROR_INVALID_HANDLE indicates we are disconnected
         if (saved_errno == ERROR_INVALID_HANDLE)
           usb_kick(handle);
         break;
       }
       errno = saved_errno;
     }
   } else {
     D("usb_read NULL handle\n");
     SetLastError(ERROR_INVALID_HANDLE);
   }

   D("usb_read failed: %d\n", errno);

   return -1;
 }

 void usb_cleanup_handle(usb_handle* handle) {
   if (NULL != handle) {
     if (NULL != handle->interface_name)
       free(handle->interface_name);
     if (NULL != handle->adb_write_pipe)
       AdbCloseHandle(handle->adb_write_pipe);
     if (NULL != handle->adb_read_pipe)
       AdbCloseHandle(handle->adb_read_pipe);
     if (NULL != handle->adb_interface)
       AdbCloseHandle(handle->adb_interface);

     handle->interface_name = NULL;
     handle->adb_write_pipe = NULL;
     handle->adb_read_pipe = NULL;
     handle->adb_interface = NULL;
   }
 }

 void usb_kick(usb_handle* handle) {
   if (NULL != handle) {
     adb_mutex_lock(&usb_lock);

     usb_cleanup_handle(handle);

     adb_mutex_unlock(&usb_lock);
   } else {
     SetLastError(ERROR_INVALID_HANDLE);
     errno = ERROR_INVALID_HANDLE;
   }
 }

 int usb_close(usb_handle* handle) {
   D("usb_close\n");

   if (NULL != handle) {
     // Remove handle from the list
     adb_mutex_lock(&usb_lock);

     if ((handle->next != handle) && (handle->prev != handle)) {
       handle->next->prev = handle->prev;
       handle->prev->next = handle->next;
       handle->prev = handle;
       handle->next = handle;
     }

     adb_mutex_unlock(&usb_lock);

     // Cleanup handle
     usb_cleanup_handle(handle);
     free(handle);
   }

   return 0;
 }

 const char *usb_name(usb_handle* handle) {
   if (NULL == handle) {
     SetLastError(ERROR_INVALID_HANDLE);
     errno = ERROR_INVALID_HANDLE;
     return NULL;
   }

   return (const char*)handle->interface_name;
 }

 int recognized_device(usb_handle* handle) {
   if (NULL == handle)
     return 0;

   // Check vendor and product id first
   USB_DEVICE_DESCRIPTOR device_desc;

   if (!AdbGetUsbDeviceDescriptor(handle->adb_interface,
                                  &device_desc)) {
     return 0;
   }

   // Then check interface properties
   USB_INTERFACE_DESCRIPTOR interf_desc;

   if (!AdbGetUsbInterfaceDescriptor(handle->adb_interface,
                                     &interf_desc)) {
     return 0;
   }

   // Must have two endpoints
   if (2 != interf_desc.bNumEndpoints) {
     return 0;
   }

   if (is_adb_interface(device_desc.idVendor, device_desc.idProduct,
       interf_desc.bInterfaceClass, interf_desc.bInterfaceSubClass, interf_desc.bInterfaceProtocol)) {

     if(interf_desc.bInterfaceProtocol == 0x01) {
       AdbEndpointInformation endpoint_info;
       // assuming zero is a valid bulk endpoint ID
       if (AdbGetEndpointInformation(handle->adb_interface, 0, &endpoint_info)) {
         handle->zero_mask = endpoint_info.max_packet_size - 1;
       }
     }

     return 1;
   }

   return 0;
 }

 void find_devices() {
         usb_handle* handle = NULL;
   char entry_buffer[2048];
   char interf_name[2048];
   AdbInterfaceInfo* next_interface = (AdbInterfaceInfo*)(&entry_buffer[0]);
   unsigned long entry_buffer_size = sizeof(entry_buffer);
   char* copy_name;

   // Enumerate all present and active interfaces.
   ADBAPIHANDLE enum_handle =
     AdbEnumInterfaces(usb_class_id, true, true, true);

   if (NULL == enum_handle)
     return;

   while (AdbNextInterface(enum_handle, next_interface, &entry_buffer_size)) {
     // TODO: FIXME - temp hack converting wchar_t into char.
     // It would be better to change AdbNextInterface so it will return
     // interface name as single char string.
     const wchar_t* wchar_name = next_interface->device_name;
     for(copy_name = interf_name;
         L'\0' != *wchar_name;
         wchar_name++, copy_name++) {
       *copy_name = (char)(*wchar_name);
     }
     *copy_name = '\0';

     // Lets see if we already have this device in the list
     if (!known_device(interf_name)) {
       // This seems to be a new device. Open it!
         handle = do_usb_open(next_interface->device_name);
         if (NULL != handle) {
         // Lets see if this interface (device) belongs to us
         if (recognized_device(handle)) {
           D("adding a new device %s\n", interf_name);
           char serial_number[512];
           unsigned long serial_number_len = sizeof(serial_number);
           if (AdbGetSerialNumber(handle->adb_interface,
                                 serial_number,
                                 &serial_number_len,
                                 true)) {
             // Lets make sure that we don't duplicate this device
             if (register_new_device(handle)) {
               register_usb_transport(handle, serial_number, NULL, 1);
             } else {
               D("register_new_device failed for %s\n", interf_name);
               usb_cleanup_handle(handle);
               free(handle);
             }
           } else {
             D("cannot get serial number\n");
             usb_cleanup_handle(handle);
             free(handle);
           }
         } else {
           usb_cleanup_handle(handle);
           free(handle);
         }
       }
     }

     entry_buffer_size = sizeof(entry_buffer);
   }

   AdbCloseHandle(enum_handle);
 }
	/*
	* Copyright (C) 2007 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#define TRACE_TAG TRACE_USB

	#include "sysdeps.h"

	#include <winsock2.h> // winsock.h must be included before windows.h.
	#include <adb_api.h>
	#include <errno.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <usb100.h>
	#include <windows.h>
	#include <winerror.h>

	#include "adb.h"
	#include "transport.h"

	/** Structure usb_handle describes our connection to the usb device via
	AdbWinApi.dll. This structure is returned from usb_open() routine and
	is expected in each subsequent call that is accessing the device.
	*/
	struct usb_handle {
	/// Previous entry in the list of opened usb handles
	usb_handle *prev;

	/// Next entry in the list of opened usb handles
	usb_handle *next;

	/// Handle to USB interface
	ADBAPIHANDLE adb_interface;

	/// Handle to USB read pipe (endpoint)
	ADBAPIHANDLE adb_read_pipe;

	/// Handle to USB write pipe (endpoint)
	ADBAPIHANDLE adb_write_pipe;

	/// Interface name
	char* interface_name;

	/// Mask for determining when to use zero length packets
	unsigned zero_mask;
	};

	/// Class ID assigned to the device by androidusb.sys
	static const GUID usb_class_id = ANDROID_USB_CLASS_ID;

	/// List of opened usb handles
	static usb_handle handle_list = {
	.prev = &handle_list,
	.next = &handle_list,
	};

	/// Locker for the list of opened usb handles
	ADB_MUTEX_DEFINE( usb_lock );

	/// Checks if there is opened usb handle in handle_list for this device.
	int known_device(const char* dev_name);

	/// Checks if there is opened usb handle in handle_list for this device.
	/// usb_lock mutex must be held before calling this routine.
	int known_device_locked(const char* dev_name);

	/// Registers opened usb handle (adds it to handle_list).
	int register_new_device(usb_handle* handle);

	/// Checks if interface (device) matches certain criteria
	int recognized_device(usb_handle* handle);

	/// Enumerates present and available interfaces (devices), opens new ones and
	/// registers usb transport for them.
	void find_devices();

	/// Entry point for thread that polls (every second) for new usb interfaces.
	/// This routine calls find_devices in infinite loop.
	void* device_poll_thread(void* unused);

	/// Initializes this module
	void usb_init();

	/// Cleans up this module
	void usb_cleanup();

	/// Opens usb interface (device) by interface (device) name.
	usb_handle* do_usb_open(const wchar_t* interface_name);

	/// Writes data to the opened usb handle
	int usb_write(usb_handle* handle, const void* data, int len);

	/// Reads data using the opened usb handle
	int usb_read(usb_handle handle, void data, int len);

	/// Cleans up opened usb handle
	void usb_cleanup_handle(usb_handle* handle);

	/// Cleans up (but don't close) opened usb handle
	void usb_kick(usb_handle* handle);

	/// Closes opened usb handle
	int usb_close(usb_handle* handle);

	/// Gets interface (device) name for an opened usb handle
	const char usb_name(usb_handle handle);

	int known_device_locked(const char* dev_name) {
	usb_handle* usb;

	if (NULL != dev_name) {
	// Iterate through the list looking for the name match.
	for(usb = handle_list.next; usb != &handle_list; usb = usb->next) {
	// In Windows names are not case sensetive!
	if((NULL != usb->interface_name) &&
	(0 == stricmp(usb->interface_name, dev_name))) {
	return 1;
	}
	}
	}

	return 0;
	}

	int known_device(const char* dev_name) {
	int ret = 0;

	if (NULL != dev_name) {
	adb_mutex_lock(&usb_lock);
	ret = known_device_locked(dev_name);
	adb_mutex_unlock(&usb_lock);
	}

	return ret;
	}

	int register_new_device(usb_handle* handle) {
	if (NULL == handle)
	return 0;

	adb_mutex_lock(&usb_lock);

	// Check if device is already in the list
	if (known_device_locked(handle->interface_name)) {
	adb_mutex_unlock(&usb_lock);
	return 0;
	}

	// Not in the list. Add this handle to the list.
	handle->next = &handle_list;
	handle->prev = handle_list.prev;
	handle->prev->next = handle;
	handle->next->prev = handle;

	adb_mutex_unlock(&usb_lock);

	return 1;
	}

	void* device_poll_thread(void* unused) {
	D("Created device thread\n");

	while(1) {
	find_devices();
	adb_sleep_ms(1000);
	}

	return NULL;
	}

	void usb_init() {
	adb_thread_t tid;

	if(adb_thread_create(&tid, device_poll_thread, NULL)) {
	fatal_errno("cannot create input thread");
	}
	}

	void usb_cleanup() {
	}

	usb_handle* do_usb_open(const wchar_t* interface_name) {
	// Allocate our handle
	usb_handle* ret = (usb_handle*)malloc(sizeof(usb_handle));
	if (NULL == ret)
	return NULL;

	// Set linkers back to the handle
	ret->next = ret;
	ret->prev = ret;

	// Create interface.
	ret->adb_interface = AdbCreateInterfaceByName(interface_name);

	if (NULL == ret->adb_interface) {
	free(ret);
	errno = GetLastError();
	return NULL;
	}

	// Open read pipe (endpoint)
	ret->adb_read_pipe =
	AdbOpenDefaultBulkReadEndpoint(ret->adb_interface,
	AdbOpenAccessTypeReadWrite,
	AdbOpenSharingModeReadWrite);
	if (NULL != ret->adb_read_pipe) {
	// Open write pipe (endpoint)
	ret->adb_write_pipe =
	AdbOpenDefaultBulkWriteEndpoint(ret->adb_interface,
	AdbOpenAccessTypeReadWrite,
	AdbOpenSharingModeReadWrite);
	if (NULL != ret->adb_write_pipe) {
	// Save interface name
	unsigned long name_len = 0;

	// First get expected name length
	AdbGetInterfaceName(ret->adb_interface,
	NULL,
	&name_len,
	true);
	if (0 != name_len) {
	ret->interface_name = (char*)malloc(name_len);

	if (NULL != ret->interface_name) {
	// Now save the name
	if (AdbGetInterfaceName(ret->adb_interface,
	ret->interface_name,
	&name_len,
	true)) {
	// We're done at this point
	return ret;
	}
	} else {
	SetLastError(ERROR_OUTOFMEMORY);
	}
	}
	}
	}

	// Something went wrong.
	int saved_errno = GetLastError();
	usb_cleanup_handle(ret);
	free(ret);
	SetLastError(saved_errno);

	return NULL;
	}

	int usb_write(usb_handle* handle, const void* data, int len) {
	unsigned long time_out = 5000;
	unsigned long written = 0;
	int ret;

	D("usb_write %d\n", len);
	if (NULL != handle) {
	// Perform write
	ret = AdbWriteEndpointSync(handle->adb_write_pipe,
	(void*)data,
	(unsigned long)len,
	&written,
	time_out);
	int saved_errno = GetLastError();

	if (ret) {
	// Make sure that we've written what we were asked to write
	D("usb_write got: %ld, expected: %d\n", written, len);
	if (written == (unsigned long)len) {
	if(handle->zero_mask && (len & handle->zero_mask) == 0) {
	// Send a zero length packet
	AdbWriteEndpointSync(handle->adb_write_pipe,
	(void*)data,
	0,
	&written,
	time_out);
	}
	return 0;
	}
	} else {
	// assume ERROR_INVALID_HANDLE indicates we are disconnected
	if (saved_errno == ERROR_INVALID_HANDLE)
	usb_kick(handle);
	}
	errno = saved_errno;
	} else {
	D("usb_write NULL handle\n");
	SetLastError(ERROR_INVALID_HANDLE);
	}

	D("usb_write failed: %d\n", errno);

	return -1;
	}

	int usb_read(usb_handle handle, void data, int len) {
	unsigned long time_out = 0;
	unsigned long read = 0;
	int ret;

	D("usb_read %d\n", len);
	if (NULL != handle) {
	while (len > 0) {
	int xfer = (len > 4096) ? 4096 : len;

	ret = AdbReadEndpointSync(handle->adb_read_pipe,
	data,
	(unsigned long)xfer,
	&read,
	time_out);
	int saved_errno = GetLastError();
	D("usb_write got: %ld, expected: %d, errno: %d\n", read, xfer, saved_errno);
	if (ret) {
	data = (char *)data + read;
	len -= read;

	if (len == 0)
	return 0;
	} else {
	// assume ERROR_INVALID_HANDLE indicates we are disconnected
	if (saved_errno == ERROR_INVALID_HANDLE)
	usb_kick(handle);
	break;
	}
	errno = saved_errno;
	}
	} else {
	D("usb_read NULL handle\n");
	SetLastError(ERROR_INVALID_HANDLE);
	}

	D("usb_read failed: %d\n", errno);

	return -1;
	}

	void usb_cleanup_handle(usb_handle* handle) {
	if (NULL != handle) {
	if (NULL != handle->interface_name)
	free(handle->interface_name);
	if (NULL != handle->adb_write_pipe)
	AdbCloseHandle(handle->adb_write_pipe);
	if (NULL != handle->adb_read_pipe)
	AdbCloseHandle(handle->adb_read_pipe);
	if (NULL != handle->adb_interface)
	AdbCloseHandle(handle->adb_interface);

	handle->interface_name = NULL;
	handle->adb_write_pipe = NULL;
	handle->adb_read_pipe = NULL;
	handle->adb_interface = NULL;
	}
	}

	void usb_kick(usb_handle* handle) {
	if (NULL != handle) {
	adb_mutex_lock(&usb_lock);

	usb_cleanup_handle(handle);

	adb_mutex_unlock(&usb_lock);
	} else {
	SetLastError(ERROR_INVALID_HANDLE);
	errno = ERROR_INVALID_HANDLE;
	}
	}

	int usb_close(usb_handle* handle) {
	D("usb_close\n");

	if (NULL != handle) {
	// Remove handle from the list
	adb_mutex_lock(&usb_lock);

	if ((handle->next != handle) && (handle->prev != handle)) {
	handle->next->prev = handle->prev;
	handle->prev->next = handle->next;
	handle->prev = handle;
	handle->next = handle;
	}

	adb_mutex_unlock(&usb_lock);

	// Cleanup handle
	usb_cleanup_handle(handle);
	free(handle);
	}

	return 0;
	}

	const char usb_name(usb_handle handle) {
	if (NULL == handle) {
	SetLastError(ERROR_INVALID_HANDLE);
	errno = ERROR_INVALID_HANDLE;
	return NULL;
	}

	return (const char*)handle->interface_name;
	}

	int recognized_device(usb_handle* handle) {
	if (NULL == handle)
	return 0;

	// Check vendor and product id first
	USB_DEVICE_DESCRIPTOR device_desc;

	if (!AdbGetUsbDeviceDescriptor(handle->adb_interface,
	&device_desc)) {
	return 0;
	}

	// Then check interface properties
	USB_INTERFACE_DESCRIPTOR interf_desc;

	if (!AdbGetUsbInterfaceDescriptor(handle->adb_interface,
	&interf_desc)) {
	return 0;
	}

	// Must have two endpoints
	if (2 != interf_desc.bNumEndpoints) {
	return 0;
	}

	if (is_adb_interface(device_desc.idVendor, device_desc.idProduct,
	interf_desc.bInterfaceClass, interf_desc.bInterfaceSubClass, interf_desc.bInterfaceProtocol)) {

	if(interf_desc.bInterfaceProtocol == 0x01) {
	AdbEndpointInformation endpoint_info;
	// assuming zero is a valid bulk endpoint ID
	if (AdbGetEndpointInformation(handle->adb_interface, 0, &endpoint_info)) {
	handle->zero_mask = endpoint_info.max_packet_size - 1;
	}
	}

	return 1;
	}

	return 0;
	}

	void find_devices() {
	usb_handle* handle = NULL;
	char entry_buffer[2048];
	char interf_name[2048];
	AdbInterfaceInfo* next_interface = (AdbInterfaceInfo*)(&entry_buffer[0]);
	unsigned long entry_buffer_size = sizeof(entry_buffer);
	char* copy_name;

	// Enumerate all present and active interfaces.
	ADBAPIHANDLE enum_handle =
	AdbEnumInterfaces(usb_class_id, true, true, true);

	if (NULL == enum_handle)
	return;

	while (AdbNextInterface(enum_handle, next_interface, &entry_buffer_size)) {
	// TODO: FIXME - temp hack converting wchar_t into char.
	// It would be better to change AdbNextInterface so it will return
	// interface name as single char string.
	const wchar_t* wchar_name = next_interface->device_name;
	for(copy_name = interf_name;
	L'\0' != *wchar_name;
	wchar_name++, copy_name++) {
	copy_name = (char)(wchar_name);
	}
	*copy_name = '\0';

	// Lets see if we already have this device in the list
	if (!known_device(interf_name)) {
	// This seems to be a new device. Open it!
	handle = do_usb_open(next_interface->device_name);
	if (NULL != handle) {
	// Lets see if this interface (device) belongs to us
	if (recognized_device(handle)) {
	D("adding a new device %s\n", interf_name);
	char serial_number[512];
	unsigned long serial_number_len = sizeof(serial_number);
	if (AdbGetSerialNumber(handle->adb_interface,
	serial_number,
	&serial_number_len,
	true)) {
	// Lets make sure that we don't duplicate this device
	if (register_new_device(handle)) {
	register_usb_transport(handle, serial_number, NULL, 1);
	} else {
	D("register_new_device failed for %s\n", interf_name);
	usb_cleanup_handle(handle);
	free(handle);
	}
	} else {
	D("cannot get serial number\n");
	usb_cleanup_handle(handle);
	free(handle);
	}
	} else {
	usb_cleanup_handle(handle);
	free(handle);
	}
	}
	}

	entry_buffer_size = sizeof(entry_buffer);
	}

	AdbCloseHandle(enum_handle);
	}