From 73698066d142a82468aa1c4c2bef52bbef919a7c Mon Sep 17 00:00:00 2001 From: Simon Rozman Date: Fri, 2 Aug 2019 14:53:02 +0200 Subject: wintun: refactor `err == nil` error checking Signed-off-by: Simon Rozman --- tun/wintun/wintun_windows.go | 255 ++++++++++++++++++++++++------------------- 1 file changed, 144 insertions(+), 111 deletions(-) (limited to 'tun/wintun/wintun_windows.go') diff --git a/tun/wintun/wintun_windows.go b/tun/wintun/wintun_windows.go index 09bf14f..9dd2957 100644 --- a/tun/wintun/wintun_windows.go +++ b/tun/wintun/wintun_windows.go @@ -69,14 +69,14 @@ func makeWintun(deviceInfoSet setupapi.DevInfo, deviceInfoData *setupapi.DevInfo return nil, fmt.Errorf("RegQueryValue(\"*IfType\") failed: %v", err) } - instanceId, err := deviceInfoSet.DeviceInstanceID(deviceInfoData) + instanceID, err := deviceInfoSet.DeviceInstanceID(deviceInfoData) if err != nil { return nil, fmt.Errorf("DeviceInstanceID failed: %v", err) } return &Wintun{ cfgInstanceID: ifid, - devInstanceID: instanceId, + devInstanceID: instanceID, luidIndex: uint32(luidIdx), ifType: uint32(ifType), }, nil @@ -170,42 +170,49 @@ func CreateInterface(description string, requestedGUID *windows.GUID) (wintun *W // Create an empty device info set for network adapter device class. devInfoList, err := setupapi.SetupDiCreateDeviceInfoListEx(&deviceClassNetGUID, 0, "") if err != nil { - return nil, false, fmt.Errorf("SetupDiCreateDeviceInfoListEx(%v) failed: %v", deviceClassNetGUID, err) + err = fmt.Errorf("SetupDiCreateDeviceInfoListEx(%v) failed: %v", deviceClassNetGUID, err) + return } defer devInfoList.Close() // Get the device class name from GUID. className, err := setupapi.SetupDiClassNameFromGuidEx(&deviceClassNetGUID, "") if err != nil { - return nil, false, fmt.Errorf("SetupDiClassNameFromGuidEx(%v) failed: %v", deviceClassNetGUID, err) + err = fmt.Errorf("SetupDiClassNameFromGuidEx(%v) failed: %v", deviceClassNetGUID, err) + return } // Create a new device info element and add it to the device info set. deviceData, err := devInfoList.CreateDeviceInfo(className, &deviceClassNetGUID, description, 0, setupapi.DICD_GENERATE_ID) if err != nil { - return nil, false, fmt.Errorf("SetupDiCreateDeviceInfo failed: %v", err) + err = fmt.Errorf("SetupDiCreateDeviceInfo failed: %v", err) + return } err = setQuietInstall(devInfoList, deviceData) if err != nil { - return nil, false, fmt.Errorf("Setting quiet installation failed: %v", err) + err = fmt.Errorf("Setting quiet installation failed: %v", err) + return } // Set a device information element as the selected member of a device information set. err = devInfoList.SetSelectedDevice(deviceData) if err != nil { - return nil, false, fmt.Errorf("SetupDiSetSelectedDevice failed: %v", err) + err = fmt.Errorf("SetupDiSetSelectedDevice failed: %v", err) + return } // Set Plug&Play device hardware ID property. err = devInfoList.SetDeviceRegistryPropertyString(deviceData, setupapi.SPDRP_HARDWAREID, hardwareID) if err != nil { - return nil, false, fmt.Errorf("SetupDiSetDeviceRegistryProperty(SPDRP_HARDWAREID) failed: %v", err) + err = fmt.Errorf("SetupDiSetDeviceRegistryProperty(SPDRP_HARDWAREID) failed: %v", err) + return } err = devInfoList.BuildDriverInfoList(deviceData, setupapi.SPDIT_COMPATDRIVER) // TODO: This takes ~510ms if err != nil { - return nil, false, fmt.Errorf("SetupDiBuildDriverInfoList failed: %v", err) + err = fmt.Errorf("SetupDiBuildDriverInfoList failed: %v", err) + return } defer devInfoList.DestroyDriverInfoList(deviceData, setupapi.SPDIT_COMPATDRIVER) @@ -240,156 +247,182 @@ func CreateInterface(description string, requestedGUID *windows.GUID) (wintun *W } if driverVersion == 0 { - return nil, false, fmt.Errorf("No driver for device %q installed", hardwareID) + err = fmt.Errorf("No driver for device %q installed", hardwareID) + return } // Call appropriate class installer. err = devInfoList.CallClassInstaller(setupapi.DIF_REGISTERDEVICE, deviceData) if err != nil { - return nil, false, fmt.Errorf("SetupDiCallClassInstaller(DIF_REGISTERDEVICE) failed: %v", err) + err = fmt.Errorf("SetupDiCallClassInstaller(DIF_REGISTERDEVICE) failed: %v", err) + return } // Register device co-installers if any. (Ignore errors) devInfoList.CallClassInstaller(setupapi.DIF_REGISTER_COINSTALLERS, deviceData) + var key registry.Key if requestedGUID != nil { - key, err := devInfoList.OpenDevRegKey(deviceData, setupapi.DICS_FLAG_GLOBAL, 0, setupapi.DIREG_DRV, registry.SET_VALUE) + key, err = devInfoList.OpenDevRegKey(deviceData, setupapi.DICS_FLAG_GLOBAL, 0, setupapi.DIREG_DRV, registry.SET_VALUE) if err != nil { - return nil, false, fmt.Errorf("OpenDevRegKey failed: %v", err) + err = fmt.Errorf("OpenDevRegKey failed: %v", err) + return } err = key.SetStringValue("NetSetupAnticipatedInstanceId", requestedGUID.String()) key.Close() if err != nil { - return nil, false, fmt.Errorf("SetStringValue(NetSetupAnticipatedInstanceId) failed: %v", err) + err = fmt.Errorf("SetStringValue(NetSetupAnticipatedInstanceId) failed: %v", err) + return } } // Install interfaces if any. (Ignore errors) devInfoList.CallClassInstaller(setupapi.DIF_INSTALLINTERFACES, deviceData) + defer func() { + if err != nil { + // The interface failed to install, or the interface ID was unobtainable. Clean-up. + removeDeviceParams := setupapi.RemoveDeviceParams{ + ClassInstallHeader: *setupapi.MakeClassInstallHeader(setupapi.DIF_REMOVE), + Scope: setupapi.DI_REMOVEDEVICE_GLOBAL, + } + + // Set class installer parameters for DIF_REMOVE. + if devInfoList.SetClassInstallParams(deviceData, &removeDeviceParams.ClassInstallHeader, uint32(unsafe.Sizeof(removeDeviceParams))) == nil { + // Call appropriate class installer. + if devInfoList.CallClassInstaller(setupapi.DIF_REMOVE, deviceData) == nil { + // Check if a system reboot is required. (Ignore errors) + if ret, _ := checkReboot(devInfoList, deviceData); ret { + rebootRequired = true + } + } + } + + wintun = nil + } + }() // Install the device. err = devInfoList.CallClassInstaller(setupapi.DIF_INSTALLDEVICE, deviceData) if err != nil { err = fmt.Errorf("SetupDiCallClassInstaller(DIF_INSTALLDEVICE) failed: %v", err) + return } - var key registry.Key - if err == nil { - // Check if a system reboot is required. (Ignore errors) - if ret, _ := checkReboot(devInfoList, deviceData); ret { - rebootRequired = true - } + // Check if a system reboot is required. (Ignore errors) + if ret, _ := checkReboot(devInfoList, deviceData); ret { + rebootRequired = true + } - // DIF_INSTALLDEVICE returns almost immediately, while the device installation - // continues in the background. It might take a while, before all registry - // keys and values are populated. - const pollTimeout = time.Millisecond * 50 - for i := 0; i < int(waitForRegistryTimeout/pollTimeout); i++ { - if i != 0 { - time.Sleep(pollTimeout) - } - key, err = devInfoList.OpenDevRegKey(deviceData, setupapi.DICS_FLAG_GLOBAL, 0, setupapi.DIREG_DRV, registry.QUERY_VALUE|registry.NOTIFY) - if err == nil { - break - } + // DIF_INSTALLDEVICE returns almost immediately, while the device installation + // continues in the background. It might take a while, before all registry + // keys and values are populated. + const pollTimeout = time.Millisecond * 50 + for i := 0; i < int(waitForRegistryTimeout/pollTimeout); i++ { + if i != 0 { + time.Sleep(pollTimeout) } + key, err = devInfoList.OpenDevRegKey(deviceData, setupapi.DICS_FLAG_GLOBAL, 0, setupapi.DIREG_DRV, registry.QUERY_VALUE|registry.NOTIFY) if err == nil { - _, err = registryEx.GetStringValueWait(key, "NetCfgInstanceId", waitForRegistryTimeout) - if err == nil { - _, err = registryEx.GetIntegerValueWait(key, "NetLuidIndex", waitForRegistryTimeout) - } - if err == nil { - _, err = registryEx.GetIntegerValueWait(key, "*IfType", waitForRegistryTimeout) - } - key.Close() + break } } - - if err == nil { - // Get network interface. - wintun, err = makeWintun(devInfoList, deviceData) + if err != nil { + err = fmt.Errorf("SetupDiOpenDevRegKey failed: %v", err) + return } - - if err == nil { - // Wait for network registry key to emerge and populate. - key, err = registryEx.OpenKeyWait( - registry.LOCAL_MACHINE, - wintun.netRegKeyName(), - registry.QUERY_VALUE|registry.NOTIFY, - waitForRegistryTimeout) - if err == nil { - _, err = registryEx.GetStringValueWait(key, "Name", waitForRegistryTimeout) - if err == nil { - _, err = registryEx.GetStringValueWait(key, "PnPInstanceId", waitForRegistryTimeout) - } - key.Close() - } + defer key.Close() + _, err = registryEx.GetStringValueWait(key, "NetCfgInstanceId", waitForRegistryTimeout) + if err != nil { + err = fmt.Errorf("GetStringValueWait(NetCfgInstanceId) failed: %v", err) + return } - - if err == nil { - // Wait for TCP/IP adapter registry key to emerge and populate. - key, err = registryEx.OpenKeyWait( - registry.LOCAL_MACHINE, - wintun.tcpipAdapterRegKeyName(), registry.QUERY_VALUE|registry.NOTIFY, - waitForRegistryTimeout) - if err == nil { - _, err = registryEx.GetStringValueWait(key, "IpConfig", waitForRegistryTimeout) - key.Close() - } + _, err = registryEx.GetIntegerValueWait(key, "NetLuidIndex", waitForRegistryTimeout) + if err != nil { + err = fmt.Errorf("GetIntegerValueWait(NetLuidIndex) failed: %v", err) + return + } + _, err = registryEx.GetIntegerValueWait(key, "*IfType", waitForRegistryTimeout) + if err != nil { + err = fmt.Errorf("GetIntegerValueWait(*IfType) failed: %v", err) + return } - var tcpipInterfaceRegKeyName string - if err == nil { - tcpipInterfaceRegKeyName, err = wintun.tcpipInterfaceRegKeyName() - if err == nil { - // Wait for TCP/IP interface registry key to emerge. - key, err = registryEx.OpenKeyWait( - registry.LOCAL_MACHINE, - tcpipInterfaceRegKeyName, registry.QUERY_VALUE, - waitForRegistryTimeout) - if err == nil { - key.Close() - } - } + // Get network interface. + wintun, err = makeWintun(devInfoList, deviceData) + if err != nil { + err = fmt.Errorf("makeWintun failed: %v", err) + return } - // - // All the registry keys and values we're relying on are present now. - // + // Wait for network registry key to emerge and populate. + key, err = registryEx.OpenKeyWait( + registry.LOCAL_MACHINE, + wintun.netRegKeyName(), + registry.QUERY_VALUE|registry.NOTIFY, + waitForRegistryTimeout) + if err != nil { + err = fmt.Errorf("makeWintun failed: %v", err) + return + } + defer key.Close() + _, err = registryEx.GetStringValueWait(key, "Name", waitForRegistryTimeout) + if err != nil { + err = fmt.Errorf("GetStringValueWait(Name) failed: %v", err) + return + } + _, err = registryEx.GetStringValueWait(key, "PnPInstanceId", waitForRegistryTimeout) + if err != nil { + err = fmt.Errorf("GetStringValueWait(PnPInstanceId) failed: %v", err) + return + } - if err == nil { - // Disable dead gateway detection on our interface. - key, err = registry.OpenKey(registry.LOCAL_MACHINE, tcpipInterfaceRegKeyName, registry.SET_VALUE) - if err != nil { - err = fmt.Errorf("Error opening interface-specific TCP/IP network registry key: %v", err) - } else { - key.SetDWordValue("EnableDeadGWDetect", 0) - key.Close() - } + // Wait for TCP/IP adapter registry key to emerge and populate. + key, err = registryEx.OpenKeyWait( + registry.LOCAL_MACHINE, + wintun.tcpipAdapterRegKeyName(), registry.QUERY_VALUE|registry.NOTIFY, + waitForRegistryTimeout) + if err != nil { + err = fmt.Errorf("OpenKeyWait(HKLM\\%s) failed: %v", wintun.tcpipAdapterRegKeyName(), err) + return + } + defer key.Close() + _, err = registryEx.GetStringValueWait(key, "IpConfig", waitForRegistryTimeout) + if err != nil { + err = fmt.Errorf("GetStringValueWait(IpConfig) failed: %v", err) + return } - if err == nil { - return wintun, rebootRequired, nil + tcpipInterfaceRegKeyName, err := wintun.tcpipInterfaceRegKeyName() + if err != nil { + err = fmt.Errorf("tcpipInterfaceRegKeyName failed: %v", err) + return } - // The interface failed to install, or the interface ID was unobtainable. Clean-up. - removeDeviceParams := setupapi.RemoveDeviceParams{ - ClassInstallHeader: *setupapi.MakeClassInstallHeader(setupapi.DIF_REMOVE), - Scope: setupapi.DI_REMOVEDEVICE_GLOBAL, + // Wait for TCP/IP interface registry key to emerge. + key, err = registryEx.OpenKeyWait( + registry.LOCAL_MACHINE, + tcpipInterfaceRegKeyName, registry.QUERY_VALUE, + waitForRegistryTimeout) + if err != nil { + err = fmt.Errorf("OpenKeyWait(HKLM\\%s) failed: %v", tcpipInterfaceRegKeyName, err) + return } + key.Close() - // Set class installer parameters for DIF_REMOVE. - if devInfoList.SetClassInstallParams(deviceData, &removeDeviceParams.ClassInstallHeader, uint32(unsafe.Sizeof(removeDeviceParams))) == nil { - // Call appropriate class installer. - if devInfoList.CallClassInstaller(setupapi.DIF_REMOVE, deviceData) == nil { - // Check if a system reboot is required. (Ignore errors) - if ret, _ := checkReboot(devInfoList, deviceData); ret { - rebootRequired = true - } - } + // + // All the registry keys and values we're relying on are present now. + // + + // Disable dead gateway detection on our interface. + key, err = registry.OpenKey(registry.LOCAL_MACHINE, tcpipInterfaceRegKeyName, registry.SET_VALUE) + if err != nil { + err = fmt.Errorf("Error opening interface-specific TCP/IP network registry key: %v", err) + return } + key.SetDWordValue("EnableDeadGWDetect", 0) + key.Close() - return nil, rebootRequired, err + return } // DeleteInterface deletes a Wintun interface. This function succeeds -- cgit v1.2.3