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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
#ifndef mozilla_SameBinary_h
#define mozilla_SameBinary_h
#include "mozilla/WinHeaderOnlyUtils.h"
#include "mozilla/NativeNt.h"
#include "nsWindowsHelpers.h"
namespace mozilla {
class ProcessImagePath final {
PathType mType;
LauncherVoidResult mLastError;
// Using a larger buffer because an NT path may exceed MAX_PATH.
WCHAR mPathBuffer[(MAX_PATH * 2) + 1];
public:
// Initialize with an NT path string of a given process handle
explicit ProcessImagePath(const nsAutoHandle& aProcess)
: mType(PathType::eNtPath), mLastError(Ok()) {
DWORD len = mozilla::ArrayLength(mPathBuffer);
if (!::QueryFullProcessImageNameW(aProcess.get(), PROCESS_NAME_NATIVE,
mPathBuffer, &len)) {
mLastError = LAUNCHER_ERROR_FROM_LAST();
return;
}
}
// Initizlize with a DOS path string of a given imagebase address
explicit ProcessImagePath(HMODULE aImageBase)
: mType(PathType::eDosPath), mLastError(Ok()) {
DWORD len = ::GetModuleFileNameW(aImageBase, mPathBuffer,
mozilla::ArrayLength(mPathBuffer));
if (!len || len == mozilla::ArrayLength(mPathBuffer)) {
mLastError = LAUNCHER_ERROR_FROM_LAST();
return;
}
}
bool IsError() const { return mLastError.isErr(); }
const WindowsErrorType& GetError() const { return mLastError.inspectErr(); }
FileUniqueId GetId() const { return FileUniqueId(mPathBuffer, mType); }
bool CompareNtPaths(const ProcessImagePath& aOther) const {
if (mLastError.isErr() || aOther.mLastError.isErr() ||
mType != PathType::eNtPath || aOther.mType != PathType::eNtPath) {
return false;
}
UNICODE_STRING path1, path2;
::RtlInitUnicodeString(&path1, mPathBuffer);
::RtlInitUnicodeString(&path2, aOther.mPathBuffer);
return !!::RtlEqualUnicodeString(&path1, &path2, TRUE);
}
};
enum class ImageFileCompareOption {
Default,
CompareNtPathsOnly,
};
static inline mozilla::LauncherResult<bool> IsSameBinaryAsParentProcess(
ImageFileCompareOption aOption = ImageFileCompareOption::Default) {
mozilla::LauncherResult<DWORD> parentPid = mozilla::nt::GetParentProcessId();
if (parentPid.isErr()) {
return parentPid.propagateErr();
}
nsAutoHandle parentProcess(::OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION,
FALSE, parentPid.unwrap()));
if (!parentProcess.get()) {
DWORD err = ::GetLastError();
if (err == ERROR_INVALID_PARAMETER || err == ERROR_ACCESS_DENIED) {
// In the ERROR_INVALID_PARAMETER case, the process identified by
// parentPid has already exited. This is a common case when the parent
// process is not Firefox, thus we should return false instead of erroring
// out.
// The ERROR_ACCESS_DENIED case can happen when the parent process is
// something that we don't have permission to query. For example, we may
// encounter this when Firefox is launched by the Windows Task Scheduler.
return false;
}
return LAUNCHER_ERROR_FROM_WIN32(err);
}
ProcessImagePath parentExe(parentProcess);
if (parentExe.IsError()) {
return ::mozilla::Err(parentExe.GetError());
}
if (aOption == ImageFileCompareOption::Default) {
bool skipFileIdComparison = false;
FileUniqueId id1 = parentExe.GetId();
if (id1.IsError()) {
// We saw a number of Win7 users failed to call NtOpenFile with
// STATUS_OBJECT_PATH_NOT_FOUND for an unknown reason. In this
// particular case, we fall back to the logic to compare NT path
// strings instead of a file id which will not fail because we don't
// need to open a file handle.
#if !defined(STATUS_OBJECT_PATH_NOT_FOUND)
constexpr NTSTATUS STATUS_OBJECT_PATH_NOT_FOUND = 0xc000003a;
#endif
const LauncherError& err = id1.GetError();
if (err.mError !=
WindowsError::FromNtStatus(STATUS_OBJECT_PATH_NOT_FOUND)) {
return ::mozilla::Err(err);
}
skipFileIdComparison = true;
}
if (!skipFileIdComparison) {
ProcessImagePath ourExe(nullptr);
if (ourExe.IsError()) {
return ::mozilla::Err(ourExe.GetError());
}
FileUniqueId id2 = ourExe.GetId();
if (id2.IsError()) {
return ::mozilla::Err(id2.GetError());
}
return id1 == id2;
}
}
nsAutoHandle ourProcess(::GetCurrentProcess());
ProcessImagePath ourExeNt(ourProcess);
if (ourExeNt.IsError()) {
return ::mozilla::Err(ourExeNt.GetError());
}
return parentExe.CompareNtPaths(ourExeNt);
}
} // namespace mozilla
#endif // mozilla_SameBinary_h