adb devices获得的设备标识

浅浅的花香味﹌ 2022-09-27 00:29 247阅读 0赞

在命令行执行adb devices，你会得到连接上的设备，结果里面有每个设备的标识(serial number)。在adb的其他命令中，你可以用adb –s 来指定用某一个设备来执行命令，但是每个设备的serial number都不一样，adb是如何得到的呢？查看adb的源码后，发现其获取serial number的代码如下：

//D:/project/android/android-1.5/development/host/windows/usb/api/adb\_interface.cpp bool AdbInterfaceObject::GetSerialNumber(void\* buffer, unsigned long\* buffer\_char\_size, bool ansi) \{ if (!IsOpened()) \{ SetLastError(ERROR\_INVALID\_HANDLE); return false; \} // Open USB device for this intefface HANDLE usb\_device\_handle = CreateFile(interface\_name().c\_str(), GENERIC\_READ, FILE\_SHARE\_READ | FILE\_SHARE\_WRITE, NULL, OPEN\_EXISTING, 0, NULL); if (INVALID\_HANDLE\_VALUE == usb\_device\_handle) return NULL; WCHAR serial\_number\[512\]; // Send IOCTL DWORD ret\_bytes = 0; BOOL ret = DeviceIoControl(usb\_device\_handle, ADB\_IOCTL\_GET\_SERIAL\_NUMBER, NULL, 0, serial\_number, sizeof(serial\_number), &ret\_bytes, NULL); // Preserve error accross CloseHandle ULONG error = ret ? NO\_ERROR : GetLastError(); ::CloseHandle(usb\_device\_handle); if (NO\_ERROR != error) \{ SetLastError(error); return false; \} unsigned long str\_len = static\_cast(wcslen(serial\_number) + 1); if ((NULL == buffer) || (\*buffer\_char\_size < str\_len)) \{ \*buffer\_char\_size = str\_len; SetLastError(ERROR\_INSUFFICIENT\_BUFFER); return false; \} if (!ansi) \{ // If user asked for wide char name just return it wcscpy(reinterpret\_cast(buffer), serial\_number); return true; \} // We need to convert name from wide char to ansi string int res = WideCharToMultiByte(CP\_ACP, 0, serial\_number, static\_cast(str\_len), reinterpret\_cast(buffer), static\_cast(\*buffer\_char\_size), NULL, NULL); return (res != 0); \}

从上面的代码可以看到，adb是通过DeviceIoControl发送ADB\_IOCTL\_GET\_SERIAL\_NUMBER获取的，而上面CreateFile使用的interface\_name是adb设备的全路径，格式如"?//usb\#vid\_xxxx&pid\_xxxx&mi\_xx\#123456789abcdef\#\{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX\}，创建adb设备的代码如下：

//D:/project/android/android-1.5/development/host/windows/usb/api/adb\_api.cpp ADBAPIHANDLE AdbCreateInterface(GUID class\_id, unsigned short vendor\_id, unsigned short product\_id, unsigned char interface\_id) \{ // Enumerate all active interfaces for the given class AdbEnumInterfaceArray interfaces; if (!EnumerateDeviceInterfaces(class\_id, DIGCF\_DEVICEINTERFACE | DIGCF\_PRESENT, true, true, &interfaces)) \{ return NULL; \} if (interfaces.empty()) \{ SetLastError(ERROR\_DEVICE\_NOT\_AVAILABLE); return NULL; \} // Now iterate over active interfaces looking for the name match. // The name is formatted as such: // "?//usb\#vid\_xxxx&pid\_xxxx&mi\_xx\#123456789abcdef\#\{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX\}" // where // vid\_xxxx is for the vendor id (xxxx are hex for the given vendor id), // pid\_xxxx is for the product id (xxxx are hex for the given product id) // mi\_xx is for the interface id (xx are hex for the given interface id) // EnumerateDeviceInterfaces will guarantee that returned interface names // will have our class id at the end of the name (those last XXXes in the // format). So, we only need to match the beginning of the name wchar\_t match\_name\[64\]; if (0xFF == interface\_id) \{ // No interface id for the name. swprintf(match\_name, L"?//usb\#vid\_%04x&pid\_%04x\#", vendor\_id, product\_id); \} else \{ // With interface id for the name. swprintf(match\_name, L"?//usb\#vid\_%04x&pid\_%04x&mi\_%02x\#", vendor\_id, product\_id, interface\_id); \} size\_t match\_len = wcslen(match\_name); for (AdbEnumInterfaceArray::iterator it = interfaces.begin(); it != interfaces.end(); it++) \{ const AdbInstanceEnumEntry& next\_interface = \*it; if (0 == wcsnicmp(match\_name, next\_interface.device\_name().c\_str(), match\_len)) \{ // Found requested interface among active interfaces. return AdbCreateInterfaceByName(next\_interface.device\_name().c\_str()); \} \} SetLastError(ERROR\_DEVICE\_NOT\_AVAILABLE); return NULL; \}

adb是每个1秒没有所有的usb设备（classid：\{0xf72fe0d4, 0xcbcb, 0x407d, \{0x88, 0x14, 0x9e, 0xd6, 0x73, 0xd0, 0xdd, 0x6b\}\}），所以插上usb后起码要1秒adb devices才能发现新设备。

//D:/project/android/android-1.5/system/core/adb/usb\_windows.c void\* device\_poll\_thread(void\* unused) \{ D("Created device thread/n"); while(1) \{ find\_devices(); adb\_sleep\_ms(1000); \} return NULL; \}

如果你用windows监听usb设备的方式去监听adb设备，你可以在PDEV\_BROADCAST\_DEVICEINTERFACE结构体的dbcc\_name字段获得GetSerialNumber函数所使用的interface\_name。