/* $Id: VirtualBoxClientImpl.cpp 71179 2018-03-02 15:08:52Z vboxsync $ */ /** @file * VirtualBox COM class implementation */ /* * Copyright (C) 2010-2017 Oracle Corporation * * This file is part of VirtualBox Open Source Edition (OSE), as * available from http://www.virtualbox.org. This file is free software; * you can redistribute it and/or modify it under the terms of the GNU * General Public License (GPL) as published by the Free Software * Foundation, in version 2 as it comes in the "COPYING" file of the * VirtualBox OSE distribution. VirtualBox OSE is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. */ #define LOG_GROUP LOG_GROUP_MAIN_VIRTUALBOXCLIENT #include "LoggingNew.h" #include "VirtualBoxClientImpl.h" #include "AutoCaller.h" #include "VBoxEvents.h" #include "VBox/com/ErrorInfo.h" #include #include #include #include #include #include #ifdef RT_OS_WINDOWS # include # include # include #endif /** Waiting time between probing whether VBoxSVC is alive. */ #define VBOXCLIENT_DEFAULT_INTERVAL 30000 /** Initialize instance counter class variable */ uint32_t VirtualBoxClient::g_cInstances = 0; LONG VirtualBoxClient::s_cUnnecessaryAtlModuleLocks = 0; // constructor / destructor ///////////////////////////////////////////////////////////////////////////// HRESULT VirtualBoxClient::FinalConstruct() { HRESULT rc = init(); BaseFinalConstruct(); return rc; } void VirtualBoxClient::FinalRelease() { uninit(); BaseFinalRelease(); } // public initializer/uninitializer for internal purposes only ///////////////////////////////////////////////////////////////////////////// /** * Initializes the VirtualBoxClient object. * * @returns COM result indicator */ HRESULT VirtualBoxClient::init() { #if defined(RT_OS_WINDOWS) && defined(VBOX_WITH_SDS) // setup COM Security to enable impersonation // This works for console VirtualBox clients, GUI has own security settings // For GUI VirtualBox it will be second call so can return TOO_LATE error HRESULT hrGUICoInitializeSecurity = CoInitializeSecurity(NULL, -1, NULL, NULL, RPC_C_AUTHN_LEVEL_DEFAULT, RPC_C_IMP_LEVEL_IMPERSONATE, NULL, EOAC_NONE, NULL); NOREF(hrGUICoInitializeSecurity); Assert(SUCCEEDED(hrGUICoInitializeSecurity) || hrGUICoInitializeSecurity == RPC_E_TOO_LATE); #endif LogFlowThisFuncEnter(); /* Enclose the state transition NotReady->InInit->Ready */ AutoInitSpan autoInitSpan(this); AssertReturn(autoInitSpan.isOk(), E_FAIL); /* Important: DO NOT USE any kind of "early return" (except the single * one above, checking the init span success) in this method. It is vital * for correct error handling that it has only one point of return, which * does all the magic on COM to signal object creation success and * reporting the error later for every API method. COM translates any * unsuccessful object creation to REGDB_E_CLASSNOTREG errors or similar * unhelpful ones which cause us a lot of grief with troubleshooting. */ HRESULT rc = S_OK; try { if (ASMAtomicIncU32(&g_cInstances) != 1) AssertFailedStmt(throw setError(E_FAIL, tr("Attempted to create more than one VirtualBoxClient instance"))); mData.m_ThreadWatcher = NIL_RTTHREAD; mData.m_SemEvWatcher = NIL_RTSEMEVENT; rc = mData.m_pVirtualBox.createLocalObject(CLSID_VirtualBox); if (FAILED(rc)) #ifdef RT_OS_WINDOWS throw i_investigateVirtualBoxObjectCreationFailure(rc); #else throw rc; #endif /* VirtualBox error return is postponed to method calls, fetch it. */ ULONG rev; rc = mData.m_pVirtualBox->COMGETTER(Revision)(&rev); if (FAILED(rc)) throw rc; rc = unconst(mData.m_pEventSource).createObject(); AssertComRCThrow(rc, setError(rc, tr("Could not create EventSource for VirtualBoxClient"))); rc = mData.m_pEventSource->init(); AssertComRCThrow(rc, setError(rc, tr("Could not initialize EventSource for VirtualBoxClient"))); /* HACK ALERT! This is for DllCanUnloadNow(). */ s_cUnnecessaryAtlModuleLocks++; AssertMsg(s_cUnnecessaryAtlModuleLocks == 1, ("%d\n", s_cUnnecessaryAtlModuleLocks)); /* Setting up the VBoxSVC watcher thread. If anything goes wrong here it * is not considered important enough to cause any sort of visible * failure. The monitoring will not be done, but that's all. */ int vrc = RTSemEventCreate(&mData.m_SemEvWatcher); if (RT_FAILURE(vrc)) { mData.m_SemEvWatcher = NIL_RTSEMEVENT; AssertRCStmt(vrc, throw setError(VBOX_E_IPRT_ERROR, tr("Failed to create semaphore (rc=%Rrc)"), vrc)); } vrc = RTThreadCreate(&mData.m_ThreadWatcher, SVCWatcherThread, this, 0, RTTHREADTYPE_INFREQUENT_POLLER, RTTHREADFLAGS_WAITABLE, "VBoxSVCWatcher"); if (RT_FAILURE(vrc)) { RTSemEventDestroy(mData.m_SemEvWatcher); mData.m_SemEvWatcher = NIL_RTSEMEVENT; AssertRCStmt(vrc, throw setError(VBOX_E_IPRT_ERROR, tr("Failed to create watcher thread (rc=%Rrc)"), vrc)); } } catch (HRESULT err) { /* we assume that error info is set by the thrower */ rc = err; } catch (...) { rc = VirtualBoxBase::handleUnexpectedExceptions(this, RT_SRC_POS); } /* Confirm a successful initialization when it's the case. Must be last, * as on failure it will uninitialize the object. */ if (SUCCEEDED(rc)) autoInitSpan.setSucceeded(); else autoInitSpan.setFailed(rc); LogFlowThisFunc(("rc=%Rhrc\n", rc)); LogFlowThisFuncLeave(); /* Unconditionally return success, because the error return is delayed to * the attribute/method calls through the InitFailed object state. */ return S_OK; } #ifdef RT_OS_WINDOWS /** * Looks into why we failed to create the VirtualBox object. * * @returns hrcCaller thru setError. * @param hrcCaller The failure status code. */ HRESULT VirtualBoxClient::i_investigateVirtualBoxObjectCreationFailure(HRESULT hrcCaller) { HRESULT hrc; # ifdef VBOX_WITH_SDS /* * Check that the VBoxSDS service is configured to run as LocalSystem and is enabled. */ WCHAR wszBuffer[256]; uint32_t uStartType; int vrc = i_getServiceAccountAndStartType(L"VBoxSDS", wszBuffer, RT_ELEMENTS(wszBuffer), &uStartType); if (RT_SUCCESS(vrc)) { LogRelFunc(("VBoxSDS service is running under the '%ls' account with start type %u.\n", wszBuffer, uStartType)); if (RTUtf16Cmp(wszBuffer, L"LocalSystem") != 0) return setError(hrcCaller, tr("VBoxSDS is misconfigured to run under the '%ls' account instead of the SYSTEM one.\n" "Reinstall VirtualBox to fix it. Alternatively you can fix it using the Windows Service Control " "Manager or by running 'qc config VBoxSDS obj=LocalSystem' on a command line."), wszBuffer); if (uStartType == SERVICE_DISABLED) return setError(hrcCaller, tr("The VBoxSDS windows service is disabled.\n" "Reinstall VirtualBox to fix it. Alternatively try reenable the service by setting it to " " 'Manual' startup type in the Windows Service management console, or by runing " "'sc config VBoxSDS start=demand' on the command line.")); } else if (vrc == VERR_NOT_FOUND) return setError(hrcCaller, tr("The VBoxSDS windows service was not found.\n" "Reinstall VirtualBox to fix it. Alternatively you can try start VirtualBox as Administrator, this " "should automatically reinstall the service, or you can run " "'VBoxSDS.exe --regservice' command from an elevated Administrator command line.")); else LogRelFunc(("VirtualBoxClient::i_getServiceAccount failed: %Rrc\n", vrc)); # endif /* * First step is to try get an IUnknown interface of the VirtualBox object. * * This will succeed even when oleaut32.msm (see @bugref{8016}, @ticketref{12087}) * is accidentally installed and messes up COM. It may also succeed when the COM * registration is partially broken (though that's unlikely to happen these days). */ IUnknown *pUnknown = NULL; hrc = CoCreateInstance(CLSID_VirtualBox, NULL, CLSCTX_LOCAL_SERVER, IID_IUnknown, (void **)&pUnknown); if (FAILED(hrc)) { if (hrc == hrcCaller) return setError(hrcCaller, tr("Completely failed to instantiate CLSID_VirtualBox: %Rhrc"), hrcCaller); return setError(hrcCaller, tr("Completely failed to instantiate CLSID_VirtualBox: %Rhrc & %Rhrc"), hrcCaller, hrc); } /* * Try query the IVirtualBox interface (should fail), if it succeed we return * straight away so we have more columns to spend on long messages below. */ IVirtualBox *pVirtualBox; hrc = pUnknown->QueryInterface(IID_IVirtualBox, (void **)&pVirtualBox); if (SUCCEEDED(hrc)) { pVirtualBox->Release(); pUnknown->Release(); return setError(hrcCaller, tr("Failed to instantiate CLSID_VirtualBox the first time, but worked when checking out why ... weird")); } /* * Check for oleaut32.msm traces in the registry. */ HKEY hKey; LSTATUS lrc = RegOpenKeyExW(HKEY_CLASSES_ROOT, L"CLSID\\{00020420-0000-0000-C000-000000000046}\\InprocServer32", 0 /*fFlags*/, KEY_QUERY_VALUE | KEY_ENUMERATE_SUB_KEYS | STANDARD_RIGHTS_READ, &hKey); if (lrc == ERROR_SUCCESS) { wchar_t wszBuf[8192]; DWORD cbBuf = sizeof(wszBuf) - sizeof(wchar_t); DWORD dwType = 0; lrc = RegQueryValueExW(hKey, L"InprocServer32", NULL /*pvReserved*/, &dwType, (BYTE *)&wszBuf[0], &cbBuf); if (lrc == ERROR_SUCCESS) { wszBuf[cbBuf / sizeof(wchar_t)] = '\0'; bool fSetError = false; /* * Try decode the string and improve the message. */ typedef UINT (WINAPI *PFNMSIDECOMPOSEDESCRIPTORW)(PCWSTR pwszDescriptor, LPWSTR pwszProductCode /*[40]*/, LPWSTR pwszFeatureId /*[40]*/, LPWSTR pwszComponentCode /*[40]*/, DWORD *poffArguments); PFNMSIDECOMPOSEDESCRIPTORW pfnMsiDecomposeDescriptorW; pfnMsiDecomposeDescriptorW = (PFNMSIDECOMPOSEDESCRIPTORW)RTLdrGetSystemSymbol("msi.dll", "MsiDecomposeDescriptorW"); if ( pfnMsiDecomposeDescriptorW && ( dwType == REG_SZ || dwType == REG_MULTI_SZ)) { wchar_t wszProductCode[RTUUID_STR_LENGTH + 2 + 16] = { 0 }; wchar_t wszFeatureId[RTUUID_STR_LENGTH + 2 + 16] = { 0 }; wchar_t wszComponentCode[RTUUID_STR_LENGTH + 2 + 16] = { 0 }; DWORD offArguments = ~(DWORD)0; UINT uRc = pfnMsiDecomposeDescriptorW(wszBuf, wszProductCode, wszFeatureId, wszComponentCode, &offArguments); if (uRc == 0) { /* * Can we resolve the product code into a name? */ typedef UINT (WINAPI *PFNMSIOPENPRODUCTW)(PCWSTR, MSIHANDLE *); PFNMSIOPENPRODUCTW pfnMsiOpenProductW; pfnMsiOpenProductW = (PFNMSIOPENPRODUCTW)RTLdrGetSystemSymbol("msi.dll", "MsiOpenProductW"); typedef UINT (WINAPI *PFNMSICLOSEHANDLE)(MSIHANDLE); PFNMSICLOSEHANDLE pfnMsiCloseHandle; pfnMsiCloseHandle = (PFNMSICLOSEHANDLE)RTLdrGetSystemSymbol("msi.dll", "MsiCloseHandle"); typedef UINT (WINAPI *PFNGETPRODUCTPROPERTYW)(MSIHANDLE, PCWSTR, PWSTR, PDWORD); PFNGETPRODUCTPROPERTYW pfnMsiGetProductPropertyW; pfnMsiGetProductPropertyW = (PFNGETPRODUCTPROPERTYW)RTLdrGetSystemSymbol("msi.dll", "MsiGetProductPropertyW"); if ( pfnMsiGetProductPropertyW && pfnMsiCloseHandle && pfnMsiOpenProductW) { MSIHANDLE hMsi = 0; uRc = pfnMsiOpenProductW(wszProductCode, &hMsi); if (uRc == 0) { static wchar_t const * const s_apwszProps[] = { INSTALLPROPERTY_INSTALLEDPRODUCTNAME, INSTALLPROPERTY_PRODUCTNAME, INSTALLPROPERTY_PACKAGENAME, }; wchar_t wszProductName[1024]; DWORD cwcProductName; unsigned i = 0; do { cwcProductName = RT_ELEMENTS(wszProductName) - 1; uRc = pfnMsiGetProductPropertyW(hMsi, s_apwszProps[i], wszProductName, &cwcProductName); } while ( ++i < RT_ELEMENTS(s_apwszProps) && ( uRc != 0 || cwcProductName < 2 || cwcProductName >= RT_ELEMENTS(wszProductName)) ); uRc = pfnMsiCloseHandle(hMsi); if (uRc == 0 && cwcProductName >= 2) { wszProductName[RT_MIN(cwcProductName, RT_ELEMENTS(wszProductName) - 1)] = '\0'; setError(hrcCaller, tr("Failed to instantiate CLSID_VirtualBox w/ IVirtualBox, but CLSID_VirtualBox w/ IUnknown works.\n" "PSDispatch looks broken by the '%ls' (%ls) program, suspecting that it features the broken oleaut32.msm module as component %ls.\n" "\n" "We suggest you try uninstall '%ls'.\n" "\n" "See also https://support.microsoft.com/en-us/kb/316911 "), wszProductName, wszProductCode, wszComponentCode, wszProductName); fSetError = true; } } } /* MSI uses COM and may mess up our stuff. So, we wait with the fallback till afterwards in this case. */ if (!fSetError) { setError(hrcCaller, tr("Failed to instantiate CLSID_VirtualBox w/ IVirtualBox, CLSID_VirtualBox w/ IUnknown works.\n" "PSDispatch looks broken by installer %ls featuring the broken oleaut32.msm module as component %ls.\n" "\n" "See also https://support.microsoft.com/en-us/kb/316911 "), wszProductCode, wszComponentCode); fSetError = true; } } } if (!fSetError) setError(hrcCaller, tr("Failed to instantiate CLSID_VirtualBox w/ IVirtualBox, CLSID_VirtualBox w/ IUnknown works.\n" "PSDispatch looks broken by some installer featuring the broken oleaut32.msm module as a component.\n" "\n" "See also https://support.microsoft.com/en-us/kb/316911 ")); } else if (lrc == ERROR_FILE_NOT_FOUND) setError(hrcCaller, tr("Failed to instantiate CLSID_VirtualBox w/ IVirtualBox, but CLSID_VirtualBox w/ IUnknown works.\n" "PSDispatch looks fine. Weird")); else setError(hrcCaller, tr("Failed to instantiate CLSID_VirtualBox w/ IVirtualBox, but CLSID_VirtualBox w/ IUnknown works.\n" "Checking out PSDispatch registration ended with error: %u (%#x)"), lrc, lrc); RegCloseKey(hKey); } pUnknown->Release(); return hrcCaller; } # ifdef VBOX_WITH_SDS /** * Gets the service account name and start type for the given service. * * @returns IPRT status code (for some reason). * @param pwszServiceName The name of the service. * @param pwszAccountName Where to return the account name. * @param cwcAccountName The length of the account name buffer (in WCHARs). * @param puStartType Where to return the start type. */ int VirtualBoxClient::i_getServiceAccountAndStartType(const wchar_t *pwszServiceName, wchar_t *pwszAccountName, size_t cwcAccountName, uint32_t *puStartType) { AssertPtr(pwszServiceName); AssertPtr(pwszAccountName); Assert(cwcAccountName); *pwszAccountName = '\0'; *puStartType = SERVICE_DEMAND_START; int vrc; // Get a handle to the SCM database. SC_HANDLE hSCManager = OpenSCManagerW(NULL /*pwszMachineName*/, NULL /*pwszDatabaseName*/, SC_MANAGER_CONNECT); if (hSCManager != NULL) { SC_HANDLE hService = OpenServiceW(hSCManager, pwszServiceName, SERVICE_QUERY_CONFIG); if (hService != NULL) { DWORD cbNeeded = sizeof(QUERY_SERVICE_CONFIGW) + _1K; if (!QueryServiceConfigW(hService, NULL, 0, &cbNeeded)) { Assert(GetLastError() == ERROR_INSUFFICIENT_BUFFER); LPQUERY_SERVICE_CONFIGW pSc = (LPQUERY_SERVICE_CONFIGW)RTMemTmpAllocZ(cbNeeded + _1K); if (pSc) { DWORD cbNeeded2 = 0; if (QueryServiceConfigW(hService, pSc, cbNeeded + _1K, &cbNeeded2)) { *puStartType = pSc->dwStartType; vrc = RTUtf16Copy(pwszAccountName, cwcAccountName, pSc->lpServiceStartName); if (RT_FAILURE(vrc)) LogRel(("Error: SDS service name is too long (%Rrc): %ls\n", vrc, pSc->lpServiceStartName)); } else { int dwError = GetLastError(); vrc = RTErrConvertFromWin32(dwError); LogRel(("Error: Failed querying '%ls' service config: %Rwc (%u) -> %Rrc; cbNeeded=%d cbNeeded2=%d\n", pwszServiceName, dwError, dwError, vrc, cbNeeded, cbNeeded2)); } RTMemTmpFree(pSc); } else { LogRel(("Error: Failed allocating %#x bytes of memory for service config!\n", cbNeeded + _1K)); vrc = VERR_NO_TMP_MEMORY; } } else { AssertLogRelMsgFailed(("Error: QueryServiceConfigW returns success with zero buffer!\n")); vrc = VERR_IPE_UNEXPECTED_STATUS; } CloseServiceHandle(hService); } else { int dwError = GetLastError(); vrc = RTErrConvertFromWin32(dwError); LogRel(("Error: Could not open service '%ls': %Rwc (%u) -> %Rrc\n", pwszServiceName, dwError, dwError, vrc)); } CloseServiceHandle(hSCManager); } else { int dwError = GetLastError(); vrc = RTErrConvertFromWin32(dwError); LogRel(("Error: Could not open SCM: %Rwc (%u) -> %Rrc\n", dwError, dwError, vrc)); } return vrc; } # endif /* VBOX_WITH_SDS */ #endif /* RT_OS_WINDOWS */ /** * Uninitializes the instance and sets the ready flag to FALSE. * Called either from FinalRelease() or by the parent when it gets destroyed. */ void VirtualBoxClient::uninit() { LogFlowThisFunc(("\n")); /* Enclose the state transition Ready->InUninit->NotReady */ AutoUninitSpan autoUninitSpan(this); if (autoUninitSpan.uninitDone()) return; if (mData.m_ThreadWatcher != NIL_RTTHREAD) { /* Signal the event semaphore and wait for the thread to terminate. * if it hangs for some reason exit anyway, this can cause a crash * though as the object will no longer be available. */ RTSemEventSignal(mData.m_SemEvWatcher); RTThreadWait(mData.m_ThreadWatcher, 30000, NULL); mData.m_ThreadWatcher = NIL_RTTHREAD; RTSemEventDestroy(mData.m_SemEvWatcher); mData.m_SemEvWatcher = NIL_RTSEMEVENT; } mData.m_pToken.setNull(); mData.m_pVirtualBox.setNull(); ASMAtomicDecU32(&g_cInstances); } // IVirtualBoxClient properties ///////////////////////////////////////////////////////////////////////////// /** * Returns a reference to the VirtualBox object. * * @returns COM status code * @param aVirtualBox Address of result variable. */ HRESULT VirtualBoxClient::getVirtualBox(ComPtr &aVirtualBox) { AutoReadLock alock(this COMMA_LOCKVAL_SRC_POS); aVirtualBox = mData.m_pVirtualBox; return S_OK; } /** * Create a new Session object and return a reference to it. * * @returns COM status code * @param aSession Address of result variable. */ HRESULT VirtualBoxClient::getSession(ComPtr &aSession) { /* this is not stored in this object, no need to lock */ ComPtr pSession; HRESULT rc = pSession.createInprocObject(CLSID_Session); if (SUCCEEDED(rc)) aSession = pSession; return rc; } /** * Return reference to the EventSource associated with this object. * * @returns COM status code * @param aEventSource Address of result variable. */ HRESULT VirtualBoxClient::getEventSource(ComPtr &aEventSource) { /* this is const, no need to lock */ aEventSource = mData.m_pEventSource; return aEventSource.isNull() ? E_FAIL : S_OK; } // IVirtualBoxClient methods ///////////////////////////////////////////////////////////////////////////// /** * Checks a Machine object for any pending errors. * * @returns COM status code * @param aMachine Machine object to check. */ HRESULT VirtualBoxClient::checkMachineError(const ComPtr &aMachine) { BOOL fAccessible = FALSE; HRESULT rc = aMachine->COMGETTER(Accessible)(&fAccessible); if (FAILED(rc)) return setError(rc, tr("Could not check the accessibility status of the VM")); else if (!fAccessible) { ComPtr pAccessError; rc = aMachine->COMGETTER(AccessError)(pAccessError.asOutParam()); if (FAILED(rc)) return setError(rc, tr("Could not get the access error message of the VM")); else { ErrorInfo info(pAccessError); ErrorInfoKeeper eik(info); return info.getResultCode(); } } return S_OK; } // private methods ///////////////////////////////////////////////////////////////////////////// /// @todo AM Add pinging of VBoxSDS /*static*/ DECLCALLBACK(int) VirtualBoxClient::SVCWatcherThread(RTTHREAD ThreadSelf, void *pvUser) { NOREF(ThreadSelf); Assert(pvUser); VirtualBoxClient *pThis = (VirtualBoxClient *)pvUser; RTSEMEVENT sem = pThis->mData.m_SemEvWatcher; RTMSINTERVAL cMillies = VBOXCLIENT_DEFAULT_INTERVAL; int vrc; /* The likelihood of early crashes are high, so start with a short wait. */ vrc = RTSemEventWait(sem, cMillies / 2); /* As long as the waiting times out keep retrying the wait. */ while (RT_FAILURE(vrc)) { { HRESULT rc = S_OK; ComPtr pV; { AutoReadLock alock(pThis COMMA_LOCKVAL_SRC_POS); pV = pThis->mData.m_pVirtualBox; } if (!pV.isNull()) { ULONG rev; rc = pV->COMGETTER(Revision)(&rev); if (FAILED_DEAD_INTERFACE(rc)) { LogRel(("VirtualBoxClient: detected unresponsive VBoxSVC (rc=%Rhrc)\n", rc)); { AutoWriteLock alock(pThis COMMA_LOCKVAL_SRC_POS); /* Throw away the VirtualBox reference, it's no longer * usable as VBoxSVC terminated in the mean time. */ pThis->mData.m_pVirtualBox.setNull(); } fireVBoxSVCAvailabilityChangedEvent(pThis->mData.m_pEventSource, FALSE); } } else { /* Try to get a new VirtualBox reference straight away, and if * this fails use an increased waiting time as very frequent * restart attempts in some wedged config can cause high CPU * and disk load. */ ComPtr pVirtualBox; ComPtr pToken; rc = pVirtualBox.createLocalObject(CLSID_VirtualBox); if (FAILED(rc)) cMillies = 3 * VBOXCLIENT_DEFAULT_INTERVAL; else { LogRel(("VirtualBoxClient: detected working VBoxSVC (rc=%Rhrc)\n", rc)); { AutoWriteLock alock(pThis COMMA_LOCKVAL_SRC_POS); /* Update the VirtualBox reference, there's a working * VBoxSVC again from now on. */ pThis->mData.m_pVirtualBox = pVirtualBox; pThis->mData.m_pToken = pToken; } fireVBoxSVCAvailabilityChangedEvent(pThis->mData.m_pEventSource, TRUE); cMillies = VBOXCLIENT_DEFAULT_INTERVAL; } } } vrc = RTSemEventWait(sem, cMillies); } return 0; } /* vi: set tabstop=4 shiftwidth=4 expandtab: */