launcher: SvcInstance implementation

build/VStudio/launcher/launcher.vcxproj

@@ -175,6 +175,9 @@
       <Project>{4a7c0b21-9e10-4c81-92de-1493efcf24eb}</Project>
     </ProjectReference>
   </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="..\..\..\src\shared\minimal.h" />
+  </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>

build/VStudio/launcher/launcher.vcxproj.filters

@@ -5,10 +5,21 @@
       <UniqueIdentifier>{4FC737F1-C7A5-4376-A066-2A32D752A2FF}</UniqueIdentifier>
       <Extensions>cpp;c;cc;cxx;def;odl;idl;hpj;bat;asm;asmx</Extensions>
     </Filter>
+    <Filter Include="Include">
+      <UniqueIdentifier>{11e7c0f2-7782-43ee-84fa-9e56efbe39de}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="Include\shared">
+      <UniqueIdentifier>{d83ea433-d9f7-494c-90b9-3a8997483cd9}</UniqueIdentifier>
+    </Filter>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\..\..\src\launcher\launcher.c">
       <Filter>Source</Filter>
     </ClCompile>
   </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="..\..\..\src\shared\minimal.h">
+      <Filter>Include\shared</Filter>
+    </ClInclude>
+  </ItemGroup>
 </Project>

src/launcher/launcher.c

@@ -16,21 +16,289 @@
  */
 
 #include <winfsp/winfsp.h>
+#include <shared/minimal.h>
+#include <sddl.h>
 
-#define PROGNAME                        "winfsp-launcher"
+#define PROGNAME                        "WinFsp-Launcher"
+#define REGKEY                          "SYSTEM\\CurrentControlSet\\Services\\" PROGNAME "\\Services"
 
-NTSTATUS SvcStart(FSP_SERVICE *Service, ULONG argc, PWSTR *argv)
+HANDLE ProcessHeap;
+
+typedef struct
 {
+    PWSTR ClassName;
+    PWSTR InstanceName;
+    PWSTR CommandLine;
+    DWORD ProcessId;
+    HANDLE Process;
+    HANDLE ProcessWait;
+    LIST_ENTRY ListEntry;
+    WCHAR Buffer[];
+} SVC_INSTANCE;
+
+static CRITICAL_SECTION SvcInstanceLock;
+static LIST_ENTRY SvcInstanceList = { &SvcInstanceList, &SvcInstanceList };
+
+static VOID CALLBACK SvcInstanceTerminated(PVOID Context, BOOLEAN Fired);
+
+static SVC_INSTANCE *SvcInstanceFromName(PWSTR InstanceName)
+{
+    SVC_INSTANCE *SvcInstance;
+    PLIST_ENTRY ListEntry;
+
+    for (ListEntry = SvcInstanceList.Flink;
+        &SvcInstanceList != ListEntry;
+        ListEntry = ListEntry->Flink)
+    {
+        SvcInstance = CONTAINING_RECORD(ListEntry, SVC_INSTANCE, ListEntry);
+
+        if (0 == lstrcmpW(InstanceName, SvcInstance->InstanceName))
+            return SvcInstance;
+    }
+
+    return 0;
+}
+
+static ULONG SvcInstanceArgumentLength(PWSTR Arg)
+{
+    ULONG Length;
+
+    Length = 2; /* for beginning and ending quotes */
+    for (PWSTR P = Arg; *P; P++)
+        if (L'"' != *P)
+            Length++;
+
+    return Length;
+}
+
+static PWSTR SvcInstanceArgumentCopy(PWSTR Dest, PWSTR Arg)
+{
+    *Dest++ = L'"';
+    for (PWSTR P = Arg; *P; P++)
+        if (L'"' != *P)
+            *Dest++ = *P;
+    *Dest++ = L'"';
+
+    return Dest;
+}
+
+static NTSTATUS SvcInstanceReplaceArguments(PWSTR String, ULONG Argc, PWSTR *Argv,
+    PWSTR *PNewString)
+{
+    PWSTR NewString = 0;
+    ULONG Length;
+
+    *PNewString = 0;
+
+    Length = 0;
+    for (PWSTR P = String; *P; P++)
+    {
+        switch (*P)
+        {
+        case L'%':
+            P++;
+            if (L'0' <= *P && *P <= '9' && Argc > (ULONG)(*P - L'0'))
+                Length += SvcInstanceArgumentLength(Argv[*P - L'0']);
+            break;
+        default:
+            Length++;
+            break;
+        }
+    }
+
+    NewString = MemAlloc((Length + 1) * sizeof(WCHAR));
+    if (0 == NewString)
+        return STATUS_INSUFFICIENT_RESOURCES;
+
+    *PNewString = NewString;
+    for (PWSTR P = String, Q = NewString; *P; P++)
+    {
+        switch (*P)
+        {
+        case L'%':
+            P++;
+            if (L'0' <= *P && *P <= '9' && Argc > (ULONG)(*P - L'0'))
+                Q = SvcInstanceArgumentCopy(Q, Argv[*P - L'0']);
+            break;
+        default:
+            Q++;
+            break;
+        }
+    }
+
     return STATUS_SUCCESS;
 }
 
-NTSTATUS SvcStop(FSP_SERVICE *Service)
+NTSTATUS SvcInstanceCreate(PWSTR ClassName, PWSTR InstanceName, ULONG Argc, PWSTR *Argv,
+    SVC_INSTANCE **PSvcInstance)
 {
+    SVC_INSTANCE *SvcInstance = 0;
+    HKEY RegKey = 0;
+    DWORD RegResult, RegSize;
+    DWORD ClassNameSize, InstanceNameSize;
+    WCHAR Executable[MAX_PATH], CommandLine[512];
+    STARTUPINFOW StartupInfo;
+    PROCESS_INFORMATION ProcessInfo;
+    NTSTATUS Result;
+
+    *PSvcInstance = 0;
+
+    EnterCriticalSection(&SvcInstanceLock);
+
+    if (0 != SvcInstanceFromName(InstanceName))
+    {
+        Result = STATUS_OBJECT_NAME_COLLISION;
+        goto exit;
+    }
+
+    RegResult = RegOpenKeyExW(HKEY_LOCAL_MACHINE, L"" REGKEY, 0, KEY_READ, &RegKey);
+    if (ERROR_SUCCESS != RegResult)
+    {
+        Result = FspNtStatusFromWin32(RegResult);
+        goto exit;
+    }
+
+    RegSize = sizeof Executable;
+    RegResult = RegGetValueW(RegKey, ClassName, L"Executable", RRF_RT_REG_SZ, 0,
+        &Executable, &RegSize);
+    if (ERROR_SUCCESS != RegResult)
+    {
+        Result = FspNtStatusFromWin32(RegResult);
+        goto exit;
+    }
+
+    RegSize = sizeof CommandLine;
+    RegResult = RegGetValueW(RegKey, ClassName, L"CommandLine", RRF_RT_REG_SZ, 0,
+        &CommandLine, &RegSize);
+    if (ERROR_SUCCESS != RegResult)
+    {
+        Result = FspNtStatusFromWin32(RegResult);
+        goto exit;
+    }
+
+    RegCloseKey(RegKey);
+    RegKey = 0;
+
+    ClassNameSize = (lstrlenW(ClassName) + 1) * sizeof(WCHAR);
+    InstanceNameSize = (lstrlenW(InstanceName) + 1) * sizeof(WCHAR);
+
+    SvcInstance = MemAlloc(sizeof *SvcInstance + ClassNameSize + InstanceNameSize);
+    if (0 == SvcInstance)
+    {
+        Result = STATUS_INSUFFICIENT_RESOURCES;
+        goto exit;
+    }
+
+    memset(SvcInstance, 0, sizeof *SvcInstance);
+    memcpy(SvcInstance->Buffer, ClassName, ClassNameSize);
+    memcpy(SvcInstance->Buffer + ClassNameSize / sizeof(WCHAR), InstanceName, InstanceNameSize);
+    SvcInstance->ClassName = SvcInstance->Buffer;
+    SvcInstance->InstanceName = SvcInstance->Buffer + ClassNameSize / sizeof(WCHAR);
+
+    Result = SvcInstanceReplaceArguments(CommandLine, Argc, Argv, &SvcInstance->CommandLine);
+    if (!NT_SUCCESS(Result))
+        goto exit;
+
+    memset(&StartupInfo, 0, sizeof StartupInfo);
+    StartupInfo.cb = sizeof StartupInfo;
+    if (!CreateProcessW(0, SvcInstance->CommandLine, 0, 0, FALSE, CREATE_NEW_PROCESS_GROUP, 0, 0,
+        &StartupInfo, &ProcessInfo))
+    {
+        Result = FspNtStatusFromWin32(GetLastError());
+        goto exit;
+    }
+
+    CloseHandle(ProcessInfo.hThread);
+    SvcInstance->ProcessId = ProcessInfo.dwProcessId;
+    SvcInstance->Process = ProcessInfo.hProcess;
+
+    if (!RegisterWaitForSingleObject(&SvcInstance->ProcessWait, SvcInstance->Process,
+        SvcInstanceTerminated, SvcInstance, INFINITE, WT_EXECUTEONLYONCE))
+    {
+        /* we have no way when the new process will terminate so go ahead and close its handle */
+        FspServiceLog(EVENTLOG_WARNING_TYPE,
+            L"RegisterWaitForSingleObject = %ld", GetLastError());
+        CloseHandle(SvcInstance->Process);
+        SvcInstance->Process = 0;
+    }
+
+    InsertTailList(&SvcInstanceList, &SvcInstance->ListEntry);
+
+    *PSvcInstance = SvcInstance;
+
+    Result = STATUS_SUCCESS;
+
+exit:
+    if (!NT_SUCCESS(Result))
+    {
+        MemFree(SvcInstance->CommandLine);
+        MemFree(SvcInstance);
+    }
+
+    if (0 != RegKey)
+        RegCloseKey(RegKey);
+
+    LeaveCriticalSection(&SvcInstanceLock);
+
+    return Result;
+}
+
+VOID SvcInstanceDelete(SVC_INSTANCE *SvcInstance)
+{
+    EnterCriticalSection(&SvcInstanceLock);
+    RemoveEntryList(&SvcInstance->ListEntry);
+    LeaveCriticalSection(&SvcInstanceLock);
+
+    if (0 != SvcInstance->ProcessWait)
+        UnregisterWaitEx(SvcInstance->ProcessWait, 0);
+    if (0 != SvcInstance->Process)
+        CloseHandle(SvcInstance->Process);
+    MemFree(SvcInstance->CommandLine);
+    MemFree(SvcInstance);
+}
+
+static VOID CALLBACK SvcInstanceTerminated(PVOID Context, BOOLEAN Fired)
+{
+    SVC_INSTANCE *SvcInstance = Context;
+
+    SvcInstanceDelete(SvcInstance);
+}
+
+NTSTATUS SvcInstanceStart(PWSTR ClassName, PWSTR InstanceName, ULONG Argc, PWSTR *Argv)
+{
+    SVC_INSTANCE *SvcInstance;
+
+    return SvcInstanceCreate(ClassName, InstanceName, Argc, Argv, &SvcInstance);
+}
+
+VOID SvcInstanceStop(PWSTR InstanceName)
+{
+    SVC_INSTANCE *SvcInstance;
+
+    EnterCriticalSection(&SvcInstanceLock);
+    SvcInstance = SvcInstanceFromName(InstanceName);
+    if (0 != SvcInstance)
+        GenerateConsoleCtrlEvent(CTRL_BREAK_EVENT, SvcInstance->ProcessId);
+    LeaveCriticalSection(&SvcInstanceLock);
+}
+
+static NTSTATUS SvcStart(FSP_SERVICE *Service, ULONG argc, PWSTR *argv)
+{
+    InitializeCriticalSection(&SvcInstanceLock);
+    return STATUS_SUCCESS;
+}
+
+static NTSTATUS SvcStop(FSP_SERVICE *Service)
+{
+    DeleteCriticalSection(&SvcInstanceLock);
     return STATUS_SUCCESS;
 }
 
 int wmain(int argc, wchar_t **argv)
 {
+    ProcessHeap = GetProcessHeap();
+    if (0 == ProcessHeap)
+        return GetLastError();
     return FspServiceRun(L"" PROGNAME, SvcStart, SvcStop, 0);
 }