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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#include "ProfileUnlockerWin.h"
#include "nsCOMPtr.h"
#include "nsIFile.h"
#include "nsTArray.h"
#include "nsXPCOM.h"
namespace mozilla {
/**
* RAII class to obtain and manage a handle to a Restart Manager session.
* It opens a new handle upon construction and releases it upon destruction.
*/
class MOZ_STACK_CLASS ScopedRestartManagerSession {
public:
explicit ScopedRestartManagerSession(ProfileUnlockerWin& aUnlocker)
: mError(ERROR_INVALID_HANDLE),
mHandle((DWORD)-1) // 0 is a valid restart manager handle
,
mUnlocker(aUnlocker) {
mError = mUnlocker.StartSession(mHandle);
}
~ScopedRestartManagerSession() {
if (mError == ERROR_SUCCESS) {
mUnlocker.EndSession(mHandle);
}
}
/**
* @return true if the handle is a valid Restart Ranager handle.
*/
inline bool ok() { return mError == ERROR_SUCCESS; }
/**
* @return the Restart Manager handle to pass to other Restart Manager APIs.
*/
inline DWORD handle() { return mHandle; }
private:
DWORD mError;
DWORD mHandle;
ProfileUnlockerWin& mUnlocker;
};
ProfileUnlockerWin::ProfileUnlockerWin(const nsAString& aFileName)
: mRmStartSession(nullptr),
mRmRegisterResources(nullptr),
mRmGetList(nullptr),
mRmEndSession(nullptr),
mFileName(aFileName) {}
ProfileUnlockerWin::~ProfileUnlockerWin() {}
NS_IMPL_ISUPPORTS(ProfileUnlockerWin, nsIProfileUnlocker)
nsresult ProfileUnlockerWin::Init() {
MOZ_ASSERT(!mRestartMgrModule);
if (mFileName.IsEmpty()) {
return NS_ERROR_ILLEGAL_VALUE;
}
nsModuleHandle module(::LoadLibraryW(L"Rstrtmgr.dll"));
if (!module) {
return NS_ERROR_NOT_AVAILABLE;
}
mRmStartSession = reinterpret_cast<RMSTARTSESSION>(
::GetProcAddress(module, "RmStartSession"));
if (!mRmStartSession) {
return NS_ERROR_UNEXPECTED;
}
mRmRegisterResources = reinterpret_cast<RMREGISTERRESOURCES>(
::GetProcAddress(module, "RmRegisterResources"));
if (!mRmRegisterResources) {
return NS_ERROR_UNEXPECTED;
}
mRmGetList =
reinterpret_cast<RMGETLIST>(::GetProcAddress(module, "RmGetList"));
if (!mRmGetList) {
return NS_ERROR_UNEXPECTED;
}
mRmEndSession =
reinterpret_cast<RMENDSESSION>(::GetProcAddress(module, "RmEndSession"));
if (!mRmEndSession) {
return NS_ERROR_UNEXPECTED;
}
mRestartMgrModule.steal(module);
return NS_OK;
}
DWORD
ProfileUnlockerWin::StartSession(DWORD& aHandle) {
WCHAR sessionKey[CCH_RM_SESSION_KEY + 1] = {0};
return mRmStartSession(&aHandle, 0, sessionKey);
}
void ProfileUnlockerWin::EndSession(DWORD aHandle) { mRmEndSession(aHandle); }
NS_IMETHODIMP
ProfileUnlockerWin::Unlock(uint32_t aSeverity) {
if (!mRestartMgrModule) {
return NS_ERROR_NOT_INITIALIZED;
}
if (aSeverity != FORCE_QUIT) {
return NS_ERROR_NOT_IMPLEMENTED;
}
ScopedRestartManagerSession session(*this);
if (!session.ok()) {
return NS_ERROR_FAILURE;
}
LPCWSTR resources[] = {mFileName.get()};
DWORD error = mRmRegisterResources(session.handle(), 1, resources, 0, nullptr,
0, nullptr);
if (error != ERROR_SUCCESS) {
return NS_ERROR_FAILURE;
}
// Using a AutoTArray here because we expect the required size to be 1.
AutoTArray<RM_PROCESS_INFO, 1> info;
UINT numEntries;
UINT numEntriesNeeded = 1;
error = ERROR_MORE_DATA;
DWORD reason = RmRebootReasonNone;
while (error == ERROR_MORE_DATA) {
info.SetLength(numEntriesNeeded);
numEntries = numEntriesNeeded;
error = mRmGetList(session.handle(), &numEntriesNeeded, &numEntries,
&info[0], &reason);
}
if (error != ERROR_SUCCESS) {
return NS_ERROR_FAILURE;
}
if (numEntries == 0) {
// Nobody else is locking the file; the other process must have terminated
return NS_OK;
}
nsresult rv = NS_ERROR_FAILURE;
for (UINT i = 0; i < numEntries; ++i) {
rv = TryToTerminate(info[i].Process);
if (NS_SUCCEEDED(rv)) {
return NS_OK;
}
}
// If nothing could be unlocked then we return the error code of the last
// failure that was returned.
return rv;
}
nsresult ProfileUnlockerWin::TryToTerminate(RM_UNIQUE_PROCESS& aProcess) {
// Subtle: If the target process terminated before this call to OpenProcess,
// this call will still succeed. This is because the restart manager session
// internally retains a handle to the target process. The rules for Windows
// PIDs state that the PID of a terminated process remains valid as long as
// at least one handle to that process remains open, so when we reach this
// point the PID is still valid and the process will open successfully.
DWORD accessRights = PROCESS_QUERY_LIMITED_INFORMATION | PROCESS_TERMINATE;
nsAutoHandle otherProcess(
::OpenProcess(accessRights, FALSE, aProcess.dwProcessId));
if (!otherProcess) {
return NS_ERROR_FAILURE;
}
FILETIME creationTime, exitTime, kernelTime, userTime;
if (!::GetProcessTimes(otherProcess, &creationTime, &exitTime, &kernelTime,
&userTime)) {
return NS_ERROR_FAILURE;
}
if (::CompareFileTime(&aProcess.ProcessStartTime, &creationTime)) {
return NS_ERROR_NOT_AVAILABLE;
}
WCHAR imageName[MAX_PATH];
DWORD imageNameLen = MAX_PATH;
if (!::QueryFullProcessImageNameW(otherProcess, 0, imageName,
&imageNameLen)) {
// The error codes for this function are not very descriptive. There are
// actually two failure cases here: Either the call failed because the
// process is no longer running, or it failed for some other reason. We
// need to know which case that is.
DWORD otherProcessExitCode;
if (!::GetExitCodeProcess(otherProcess, &otherProcessExitCode) ||
otherProcessExitCode == STILL_ACTIVE) {
// The other process is still running.
return NS_ERROR_FAILURE;
}
// The other process must have terminated. We should return NS_OK so that
// this process may proceed with startup.
return NS_OK;
}
nsCOMPtr<nsIFile> otherProcessImageName;
if (NS_FAILED(NS_NewLocalFile(nsDependentString(imageName, imageNameLen),
getter_AddRefs(otherProcessImageName)))) {
return NS_ERROR_FAILURE;
}
nsAutoString otherProcessLeafName;
if (NS_FAILED(otherProcessImageName->GetLeafName(otherProcessLeafName))) {
return NS_ERROR_FAILURE;
}
imageNameLen = MAX_PATH;
if (!::QueryFullProcessImageNameW(::GetCurrentProcess(), 0, imageName,
&imageNameLen)) {
return NS_ERROR_FAILURE;
}
nsCOMPtr<nsIFile> thisProcessImageName;
if (NS_FAILED(NS_NewLocalFile(nsDependentString(imageName, imageNameLen),
getter_AddRefs(thisProcessImageName)))) {
return NS_ERROR_FAILURE;
}
nsAutoString thisProcessLeafName;
if (NS_FAILED(thisProcessImageName->GetLeafName(thisProcessLeafName))) {
return NS_ERROR_FAILURE;
}
// Make sure the image leaf names match
if (_wcsicmp(otherProcessLeafName.get(), thisProcessLeafName.get())) {
return NS_ERROR_NOT_AVAILABLE;
}
// We know that another process holds the lock and that it shares the same
// image name as our process. Let's kill it.
// Subtle: TerminateProcess returning ERROR_ACCESS_DENIED is actually an
// indicator that the target process managed to shut down on its own. In that
// case we should return NS_OK since we may proceed with startup.
if (!::TerminateProcess(otherProcess, 1) &&
::GetLastError() != ERROR_ACCESS_DENIED) {
return NS_ERROR_FAILURE;
}
return NS_OK;
}
} // namespace mozilla