Merge branch 'pvt-launcher2'

build/VStudio/tools/launcher.vcxproj

@@ -112,7 +112,7 @@
       <SubSystem>Console</SubSystem>
       <GenerateDebugInformation>true</GenerateDebugInformation>
       <IgnoreAllDefaultLibraries>true</IgnoreAllDefaultLibraries>
-      <AdditionalDependencies>%(AdditionalDependencies);rpcrt4.lib</AdditionalDependencies>
+      <AdditionalDependencies>%(AdditionalDependencies);rpcrt4.lib;userenv.lib</AdditionalDependencies>
       <StripPrivateSymbols>$(OutDir)$(TargetName).public.pdb</StripPrivateSymbols>
     </Link>
   </ItemDefinitionGroup>
@@ -134,7 +134,7 @@
       <SubSystem>Console</SubSystem>
       <GenerateDebugInformation>true</GenerateDebugInformation>
       <IgnoreAllDefaultLibraries>true</IgnoreAllDefaultLibraries>
-      <AdditionalDependencies>%(AdditionalDependencies);rpcrt4.lib</AdditionalDependencies>
+      <AdditionalDependencies>%(AdditionalDependencies);rpcrt4.lib;userenv.lib</AdditionalDependencies>
       <StripPrivateSymbols>$(OutDir)$(TargetName).public.pdb</StripPrivateSymbols>
     </Link>
   </ItemDefinitionGroup>
@@ -159,7 +159,7 @@
       <OptimizeReferences>true</OptimizeReferences>
       <GenerateDebugInformation>true</GenerateDebugInformation>
       <IgnoreAllDefaultLibraries>true</IgnoreAllDefaultLibraries>
-      <AdditionalDependencies>%(AdditionalDependencies);rpcrt4.lib</AdditionalDependencies>
+      <AdditionalDependencies>%(AdditionalDependencies);rpcrt4.lib;userenv.lib</AdditionalDependencies>
       <StripPrivateSymbols>$(OutDir)$(TargetName).public.pdb</StripPrivateSymbols>
     </Link>
   </ItemDefinitionGroup>
@@ -184,7 +184,7 @@
       <OptimizeReferences>true</OptimizeReferences>
       <GenerateDebugInformation>true</GenerateDebugInformation>
       <IgnoreAllDefaultLibraries>true</IgnoreAllDefaultLibraries>
-      <AdditionalDependencies>%(AdditionalDependencies);rpcrt4.lib</AdditionalDependencies>
+      <AdditionalDependencies>%(AdditionalDependencies);rpcrt4.lib;userenv.lib</AdditionalDependencies>
       <StripPrivateSymbols>$(OutDir)$(TargetName).public.pdb</StripPrivateSymbols>
     </Link>
   </ItemDefinitionGroup>

build/VStudio/winfsp_dll.vcxproj

@@ -51,6 +51,7 @@
     <ClCompile Include="..\..\src\dll\path.c" />
     <ClCompile Include="..\..\src\dll\service.c" />
     <ClCompile Include="..\..\src\dll\util.c" />
+    <ClCompile Include="..\..\src\dll\wksid.c" />
   </ItemGroup>
   <ItemGroup>
     <CustomBuild Include="..\..\src\dll\fuse\fuse.pc.in">

build/VStudio/winfsp_dll.vcxproj.filters

@@ -112,6 +112,9 @@
     <ClCompile Include="..\..\src\dll\fuse\fuse_compat.c">
       <Filter>Source\fuse</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\dll\wksid.c">
+      <Filter>Source</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <None Include="..\..\src\dll\library.def">

inc/winfsp/winfsp.h

@@ -1675,6 +1675,19 @@ FSP_API VOID FspServiceStop(FSP_SERVICE *Service);
  *     TRUE if the process is running in running user interactive mode.
  */
 FSP_API BOOLEAN FspServiceIsInteractive(VOID);
+/**
+ * Check if the supplied token is from the service context.
+ *
+ * @param Token
+ *     Token to check. Pass NULL to check the current process token.
+ * @param PIsLocalSystem
+ *     Pointer to a boolean that will receive a TRUE value if the token belongs to LocalSystem
+ *     and FALSE otherwise. May be NULL.
+ * @return
+ *     STATUS_SUCCESS if the token is from the service context. STATUS_ACCESS_DENIED if it is not.
+ *     Other error codes are possible.
+ */
+FSP_API NTSTATUS FspServiceContextCheck(HANDLE Token, PBOOLEAN PIsLocalSystem);
 /**
  * Log a service message.
  *
@@ -1700,6 +1713,7 @@ FSP_API VOID FspEventLogV(ULONG Type, PWSTR Format, va_list ap);
 FSP_API VOID FspDebugLogSetHandle(HANDLE Handle);
 FSP_API VOID FspDebugLog(const char *Format, ...);
 FSP_API VOID FspDebugLogSD(const char *Format, PSECURITY_DESCRIPTOR SecurityDescriptor);
+FSP_API VOID FspDebugLogSid(const char *format, PSID Sid);
 FSP_API VOID FspDebugLogFT(const char *Format, PFILETIME FileTime);
 FSP_API VOID FspDebugLogRequest(FSP_FSCTL_TRANSACT_REQ *Request);
 FSP_API VOID FspDebugLogResponse(FSP_FSCTL_TRANSACT_RSP *Response);

src/dll/debug.c

@@ -63,6 +63,21 @@ FSP_API VOID FspDebugLogSD(const char *format, PSECURITY_DESCRIPTOR SecurityDesc
         FspDebugLog(format, "invalid security descriptor");
 }
 
+FSP_API VOID FspDebugLogSid(const char *format, PSID Sid)
+{
+    char *S;
+
+    if (0 == Sid)
+        FspDebugLog(format, "null SID");
+    else if (ConvertSidToStringSidA(Sid, &S))
+    {
+        FspDebugLog(format, S);
+        LocalFree(S);
+    }
+    else
+        FspDebugLog(format, "invalid SID");
+}
+
 FSP_API VOID FspDebugLogFT(const char *format, PFILETIME FileTime)
 {
     SYSTEMTIME SystemTime;

src/dll/fs.c

@@ -16,6 +16,7 @@
  */
 
 #include <dll/library.h>
+#include <launcher/launcher.h>
 
 enum
 {
@@ -187,17 +188,101 @@ FSP_API VOID FspFileSystemDelete(FSP_FILE_SYSTEM *FileSystem)
     MemFree(FileSystem);
 }
 
+static NTSTATUS FspFileSystemLauncherDefineDosDevice(
+    WCHAR Sign, PWSTR MountPoint, PWSTR VolumeName)
+{
+    NTSTATUS Result;
+    ULONG MountPointLen, VolumeNameLen;
+    PWSTR PipeBuf = 0, P;
+    DWORD BytesTransferred;
+
+    MountPointLen = lstrlenW(MountPoint);
+    VolumeNameLen = lstrlenW(VolumeName);
+
+    if (2 != MountPointLen ||
+        FSP_FSCTL_VOLUME_NAME_SIZEMAX / sizeof(WCHAR) <= VolumeNameLen)
+        return STATUS_INVALID_PARAMETER;
+
+    PipeBuf = MemAlloc(LAUNCHER_PIPE_BUFFER_SIZE);
+    if (0 == PipeBuf)
+    {
+        Result = STATUS_INSUFFICIENT_RESOURCES;
+        goto exit;
+    }
+
+    P = PipeBuf;
+    *P++ = LauncherDefineDosDevice;
+    *P++ = Sign;
+    memcpy(P, MountPoint, MountPointLen * sizeof(WCHAR)); P += MountPointLen; *P++ = L'\0';
+    memcpy(P, VolumeName, VolumeNameLen * sizeof(WCHAR)); P += VolumeNameLen; *P++ = L'\0';
+
+    Result = FspCallNamedPipeSecurely(L"" LAUNCHER_PIPE_NAME,
+        PipeBuf, (ULONG)(P - PipeBuf) * sizeof(WCHAR), PipeBuf, LAUNCHER_PIPE_BUFFER_SIZE,
+        &BytesTransferred, NMPWAIT_USE_DEFAULT_WAIT, LAUNCHER_PIPE_OWNER);
+    if (!NT_SUCCESS(Result))
+        goto exit;
+
+    if (sizeof(WCHAR) > BytesTransferred)
+        Result = RPC_NT_PROTOCOL_ERROR;
+    else if (LauncherSuccess == PipeBuf[0])
+        Result = STATUS_SUCCESS;
+    else if (LauncherFailure == PipeBuf[0])
+    {
+        DWORD ErrorCode = 0;
+
+        for (PWSTR P = PipeBuf + 1, EndP = PipeBuf + BytesTransferred / sizeof(WCHAR); EndP > P; P++)
+        {
+            if (L'0' > *P || *P > L'9')
+                break;
+
+            ErrorCode = 10 * ErrorCode + (*P - L'0');
+        }
+
+        Result = FspNtStatusFromWin32(ErrorCode);
+        if (0 == Result)
+            Result = RPC_NT_PROTOCOL_ERROR;
+    }
+    else 
+        Result = RPC_NT_PROTOCOL_ERROR;
+
+exit:
+    MemFree(PipeBuf);
+
+    return Result;
+}
+
 static NTSTATUS FspFileSystemSetMountPoint_Drive(PWSTR MountPoint, PWSTR VolumeName,
     PHANDLE PMountHandle)
 {
+    NTSTATUS Result;
+    BOOLEAN IsLocalSystem, IsServiceContext;
+
     *PMountHandle = 0;
 
+    Result = FspServiceContextCheck(0, &IsLocalSystem);
+    IsServiceContext = NT_SUCCESS(Result) && !IsLocalSystem;
+    if (IsServiceContext)
+    {
+        /*
+         * If the current process is in the service context but not LocalSystem,
+         * ask the launcher to DefineDosDevice for us. This is because the launcher
+         * runs in the LocalSystem context and can create global drives.
+         *
+         * In this case the launcher will also add DELETE access to the drive symlink
+         * for us, so that we can make it temporary below.
+         */
+        Result = FspFileSystemLauncherDefineDosDevice(L'+', MountPoint, VolumeName);
+        if (!NT_SUCCESS(Result))
+            return Result;
+    }
+    else
+    {
         if (!DefineDosDeviceW(DDD_RAW_TARGET_PATH, MountPoint, VolumeName))
             return FspNtStatusFromWin32(GetLastError());
+    }
 
     if (0 != FspNtOpenSymbolicLinkObject)
     {
-        NTSTATUS Result;
         WCHAR SymlinkBuf[6];
         UNICODE_STRING Symlink;
         OBJECT_ATTRIBUTES Obja;
@@ -224,6 +309,13 @@ static NTSTATUS FspFileSystemSetMountPoint_Drive(PWSTR MountPoint, PWSTR VolumeN
         }
     }
 
+    /* HACK:
+     *
+     * Handles do not use the low 2 bits (unless they are console handles).
+     * Abuse this fact to remember that we are running in the service context.
+     */
+    *PMountHandle = (HANDLE)(UINT_PTR)((DWORD)(UINT_PTR)*PMountHandle | IsServiceContext);
+
     return STATUS_SUCCESS;
 }
 
@@ -411,6 +503,16 @@ exit:
 
 static VOID FspFileSystemRemoveMountPoint_Drive(PWSTR MountPoint, PWSTR VolumeName, HANDLE MountHandle)
 {
+    BOOLEAN IsServiceContext = 0 != ((DWORD)(UINT_PTR)MountHandle & 1);
+    MountHandle = (HANDLE)(UINT_PTR)((DWORD)(UINT_PTR)MountHandle & ~1);
+    if (IsServiceContext)
+        /*
+         * If the current process is in the service context but not LocalSystem,
+         * ask the launcher to DefineDosDevice for us. This is because the launcher
+         * runs in the LocalSystem context and can remove global drives.
+         */
+        FspFileSystemLauncherDefineDosDevice(L'-', MountPoint, VolumeName);
+    else
         DefineDosDeviceW(DDD_RAW_TARGET_PATH | DDD_REMOVE_DEFINITION | DDD_EXACT_MATCH_ON_REMOVE,
             MountPoint, VolumeName);
 

src/dll/fsctl.c

@@ -284,7 +284,7 @@ static NTSTATUS FspFsctlFixServiceSecurity(HANDLE SvcHandle)
      * This function adds an ACE that allows Everyone to start a service.
      */
 
-    PSID WorldSid = 0;
+    PSID WorldSid;
     PSECURITY_DESCRIPTOR SecurityDescriptor = 0;
     PSECURITY_DESCRIPTOR NewSecurityDescriptor = 0;
     EXPLICIT_ACCESSW AccessEntry;
@@ -296,18 +296,12 @@ static NTSTATUS FspFsctlFixServiceSecurity(HANDLE SvcHandle)
     NTSTATUS Result;
 
     /* get the Everyone (World) SID */
-    Size = SECURITY_MAX_SID_SIZE;
+    WorldSid = FspWksidGet(WinWorldSid);
-    WorldSid = MemAlloc(Size);
     if (0 == WorldSid)
     {
         Result = STATUS_INSUFFICIENT_RESOURCES;
         goto exit;
     }
-    if (!CreateWellKnownSid(WinWorldSid, 0, WorldSid, &Size))
-    {
-        Result = FspNtStatusFromWin32(GetLastError());
-        goto exit;
-    }
 
     /* get the service security descriptor DACL */
     Size = 0;
@@ -394,7 +388,6 @@ static NTSTATUS FspFsctlFixServiceSecurity(HANDLE SvcHandle)
 exit:
     LocalFree(NewSecurityDescriptor);
     MemFree(SecurityDescriptor);
-    MemFree(WorldSid);
 
     return Result;
 }

src/dll/library.c

@@ -44,6 +44,7 @@ BOOL WINAPI DllMain(HINSTANCE Instance, DWORD Reason, PVOID Reserved)
         FspServiceFinalize(Dynamic);
         FspEventLogFinalize(Dynamic);
         FspPosixFinalize(Dynamic);
+        FspWksidFinalize(Dynamic);
         break;
 
     case DLL_THREAD_DETACH:

src/dll/library.h

@@ -31,11 +31,15 @@
     FspDebugLog("[U] " LIBRARY_NAME "!" __FUNCTION__ ": " fmt "\n", __VA_ARGS__)
 #define DEBUGLOGSD(fmt, SD)             \
     FspDebugLogSD("[U] " LIBRARY_NAME "!" __FUNCTION__ ": " fmt "\n", SD)
+#define DEBUGLOGSID(fmt, Sid)           \
+    FspDebugLogSid("[U] " LIBRARY_NAME "!" __FUNCTION__ ": " fmt "\n", Sid)
 #else
 #define DEBUGLOG(fmt, ...)              ((void)0)
 #define DEBUGLOGSD(fmt, SD)             ((void)0)
+#define DEBUGLOGSID(fmt, Sid)           ((void)0)
 #endif
 
+VOID FspWksidFinalize(BOOLEAN Dynamic);
 VOID FspPosixFinalize(BOOLEAN Dynamic);
 VOID FspEventLogFinalize(BOOLEAN Dynamic);
 VOID FspServiceFinalize(BOOLEAN Dynamic);
@@ -49,6 +53,9 @@ NTSTATUS FspNpUnregister(VOID);
 NTSTATUS FspEventLogRegister(VOID);
 NTSTATUS FspEventLogUnregister(VOID);
 
+PSID FspWksidNew(WELL_KNOWN_SID_TYPE WellKnownSidType, PNTSTATUS PResult);
+PSID FspWksidGet(WELL_KNOWN_SID_TYPE WellKnownSidType);
+
 PWSTR FspDiagIdent(VOID);
 
 VOID FspFileSystemPeekInDirectoryBuffer(PVOID *PDirBuffer,

src/dll/posix.c

@@ -453,9 +453,12 @@ FSP_API NTSTATUS FspPosixMapPermissionsToSecurityDescriptor(
     if (!NT_SUCCESS(Result))
         goto exit;
 
-    Result = FspPosixMapUidToSid(0x10100, &WorldSid);
+    WorldSid = FspWksidGet(WinWorldSid);
-    if (!NT_SUCCESS(Result))
+    if (0 == WorldSid)
+    {
+        Result = STATUS_INSUFFICIENT_RESOURCES;
         goto exit;
+    }
 
     OwnerPerm = (Mode & 0700) >> 6;
     GroupPerm = (Mode & 0070) >> 3;
@@ -579,9 +582,6 @@ exit:
 
     MemFree(Acl);
 
-    if (0 != WorldSid)
-        FspDeleteSid(WorldSid, FspPosixMapUidToSid);
-
     if (0 != GroupSid)
         FspDeleteSid(GroupSid, FspPosixMapUidToSid);
 
@@ -649,13 +649,19 @@ FSP_API NTSTATUS FspPosixMapSecurityDescriptorToPermissions(
 
     if (0 != Acl)
     {
-        Result = FspPosixMapUidToSid(0x10100, &WorldSid);
+        WorldSid = FspWksidGet(WinWorldSid);
-        if (!NT_SUCCESS(Result))
+        if (0 == WorldSid)
+        {
+            Result = STATUS_INSUFFICIENT_RESOURCES;
             goto exit;
+        }
 
-        Result = FspPosixMapUidToSid(11, &AuthUsersSid);
+        AuthUsersSid = FspWksidGet(WinAuthenticatedUserSid);
-        if (!NT_SUCCESS(Result))
+        if (0 == AuthUsersSid)
+        {
+            Result = STATUS_INSUFFICIENT_RESOURCES;
             goto exit;
+        }
 
         OwnerAllow = OwnerDeny = GroupAllow = GroupDeny = WorldAllow = WorldDeny = 0;
 
@@ -771,12 +777,6 @@ FSP_API NTSTATUS FspPosixMapSecurityDescriptorToPermissions(
     Result = STATUS_SUCCESS;
 
 exit:
-    if (0 != AuthUsersSid)
-        FspDeleteSid(AuthUsersSid, FspPosixMapUidToSid);
-
-    if (0 != WorldSid)
-        FspDeleteSid(WorldSid, FspPosixMapUidToSid);
-
     return Result;
 
 lasterror:

src/dll/service.c

@@ -566,6 +566,106 @@ FSP_API BOOLEAN FspServiceIsInteractive(VOID)
     return IsInteractive;
 }
 
+FSP_API NTSTATUS FspServiceContextCheck(HANDLE Token, PBOOLEAN PIsLocalSystem)
+{
+    NTSTATUS Result;
+    PSID LocalSystemSid, ServiceSid;
+    BOOLEAN IsLocalSystem = FALSE;
+    BOOL HasServiceSid = FALSE;
+    HANDLE ProcessToken = 0, ImpersonationToken = 0;
+    DWORD SessionId, Size;
+    union
+    {
+        TOKEN_USER V;
+        UINT8 B[128];
+    } UserInfoBuf;
+    PTOKEN_USER UserInfo = &UserInfoBuf.V;
+
+    LocalSystemSid = FspWksidGet(WinLocalSystemSid);
+    ServiceSid = FspWksidGet(WinServiceSid);
+    if (0 == LocalSystemSid || 0 == ServiceSid)
+    {
+        Result = STATUS_INSUFFICIENT_RESOURCES;
+        goto exit;
+    }
+
+    if (0 == Token)
+    {
+        if (!OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY | TOKEN_DUPLICATE, &ProcessToken) ||
+            !DuplicateToken(ProcessToken, SecurityImpersonation, &ImpersonationToken))
+        {
+            Result = FspNtStatusFromWin32(GetLastError());
+            goto exit;
+        }
+
+        Token = ImpersonationToken;
+    }
+
+    if (!GetTokenInformation(Token, TokenSessionId, &SessionId, sizeof SessionId, &Size))
+    {
+        Result = FspNtStatusFromWin32(GetLastError());
+        goto exit;
+    }
+
+    if (0 != SessionId)
+    {
+        Result = STATUS_ACCESS_DENIED;
+        goto exit;
+    }
+
+    if (!GetTokenInformation(Token, TokenUser, UserInfo, sizeof UserInfoBuf, &Size))
+    {
+        if (ERROR_INSUFFICIENT_BUFFER != GetLastError())
+        {
+            Result = FspNtStatusFromWin32(GetLastError());
+            goto exit;
+        }
+
+        UserInfo = MemAlloc(Size);
+        if (0 == UserInfo)
+        {
+            Result = STATUS_INSUFFICIENT_RESOURCES;
+            goto exit;
+        }
+
+        if (!GetTokenInformation(Token, TokenUser, UserInfo, Size, &Size))
+        {
+            Result = FspNtStatusFromWin32(GetLastError());
+            goto exit;
+        }
+    }
+
+    IsLocalSystem = EqualSid(LocalSystemSid, UserInfo->User.Sid);
+    if (IsLocalSystem)
+    {
+        Result = STATUS_SUCCESS;
+        goto exit;
+    }
+
+    if (!CheckTokenMembership(Token, ServiceSid, &HasServiceSid))
+    {
+        Result = FspNtStatusFromWin32(GetLastError());
+        goto exit;
+    }
+
+    Result = HasServiceSid ? STATUS_SUCCESS : STATUS_ACCESS_DENIED;
+
+exit:
+    if (0 != PIsLocalSystem)
+        *PIsLocalSystem = NT_SUCCESS(Result) ? IsLocalSystem : FALSE;
+
+    if (UserInfo != &UserInfoBuf.V)
+        MemFree(UserInfo);
+
+    if (0 != ImpersonationToken)
+        CloseHandle(ImpersonationToken);
+
+    if (0 != ProcessToken)
+        CloseHandle(ProcessToken);
+
+    return Result;
+}
+
 FSP_API VOID FspServiceLog(ULONG Type, PWSTR Format, ...)
 {
     va_list ap;

src/dll/util.c

@@ -97,26 +97,16 @@ FSP_API NTSTATUS FspCallNamedPipeSecurely(PWSTR PipeName,
     {
         PSECURITY_DESCRIPTOR SecurityDescriptor = 0;
         PSID OwnerSid, WellKnownSid = 0;
-        DWORD SidSize, LastError;
+        DWORD LastError;
 
         /* if it is a small number treat it like a well known SID */
         if (1024 > (INT_PTR)Sid)
         {
-            SidSize = SECURITY_MAX_SID_SIZE;
+            WellKnownSid = FspWksidNew((INT_PTR)Sid, &Result);
-            WellKnownSid = MemAlloc(SidSize);
             if (0 == WellKnownSid)
-            {
-                Result = STATUS_INSUFFICIENT_RESOURCES;
                 goto sid_exit;
         }
 
-            if (!CreateWellKnownSid((INT_PTR)Sid, 0, WellKnownSid, &SidSize))
-            {
-                Result = FspNtStatusFromWin32(GetLastError());
-                goto sid_exit;
-            }
-        }
-
         LastError = GetSecurityInfo(Pipe, SE_FILE_OBJECT,
             OWNER_SECURITY_INFORMATION, &OwnerSid, 0, 0, 0, &SecurityDescriptor);
         if (0 != LastError)

src/dll/wksid.c

@@ -0,0 +1,108 @@
+/**
+ * @file dll/wksid.c
+ *
+ * @copyright 2015-2017 Bill Zissimopoulos
+ */
+/*
+ * This file is part of WinFsp.
+ *
+ * You can redistribute it and/or modify it under the terms of the GNU
+ * General Public License version 3 as published by the Free Software
+ * Foundation.
+ *
+ * Licensees holding a valid commercial license may use this file in
+ * accordance with the commercial license agreement provided with the
+ * software.
+ */
+
+#include <dll/library.h>
+
+static INIT_ONCE FspWksidInitOnce = INIT_ONCE_STATIC_INIT;
+static PSID FspWksidWorld;
+static PSID FspWksidAuthenticatedUser;
+static PSID FspWksidLocalSystem;
+static PSID FspWksidService;
+
+static BOOL WINAPI FspWksidInitialize(
+    PINIT_ONCE InitOnce, PVOID Parameter, PVOID *Context)
+{
+    FspWksidWorld = FspWksidNew(WinWorldSid, 0);
+    FspWksidAuthenticatedUser = FspWksidNew(WinAuthenticatedUserSid, 0);
+    FspWksidLocalSystem = FspWksidNew(WinLocalSystemSid, 0);
+    FspWksidService = FspWksidNew(WinServiceSid, 0);
+
+    //DEBUGLOGSID("FspWksidWorld=%s", FspWksidWorld);
+    //DEBUGLOGSID("FspWksidAuthenticatedUser=%s", FspWksidAuthenticatedUser);
+    //DEBUGLOGSID("FspWksidLocalSystem=%s", FspWksidLocalSystem);
+    //DEBUGLOGSID("FspWksidService=%s", FspWksidService);
+
+    return TRUE;
+}
+
+VOID FspWksidFinalize(BOOLEAN Dynamic)
+{
+    /*
+     * This function is called during DLL_PROCESS_DETACH. We must therefore keep
+     * finalization tasks to a minimum.
+     *
+     * We must deregister our event source (if any). We only do so if the library
+     * is being explicitly unloaded (rather than the process exiting).
+     */
+
+    if (Dynamic)
+    {
+        MemFree(FspWksidWorld); FspWksidWorld = 0;
+        MemFree(FspWksidAuthenticatedUser); FspWksidAuthenticatedUser = 0;
+        MemFree(FspWksidLocalSystem); FspWksidLocalSystem = 0;
+        MemFree(FspWksidService); FspWksidService = 0;
+    }
+}
+
+PSID FspWksidNew(WELL_KNOWN_SID_TYPE WellKnownSidType, PNTSTATUS PResult)
+{
+    NTSTATUS Result;
+    PSID Sid;
+    DWORD Size;
+
+    Size = SECURITY_MAX_SID_SIZE;
+    Sid = MemAlloc(Size);
+    if (0 == Sid)
+    {
+        Result = STATUS_INSUFFICIENT_RESOURCES;
+        goto exit;
+    }
+
+    if (!CreateWellKnownSid(WellKnownSidType, 0, Sid, &Size))
+    {
+        Result = FspNtStatusFromWin32(GetLastError());
+        MemFree(Sid); Sid = 0;
+        goto exit;
+    }
+
+    Result = STATUS_SUCCESS;
+
+exit:
+    if (0 != PResult)
+        *PResult = Result;
+
+    return Sid;
+}
+
+PSID FspWksidGet(WELL_KNOWN_SID_TYPE WellKnownSidType)
+{
+    InitOnceExecuteOnce(&FspWksidInitOnce, FspWksidInitialize, 0, 0);
+
+    switch (WellKnownSidType)
+    {
+    case WinWorldSid:
+        return FspWksidWorld;
+    case WinAuthenticatedUserSid:
+        return FspWksidAuthenticatedUser;
+    case WinLocalSystemSid:
+        return FspWksidLocalSystem;
+    case WinServiceSid:
+        return FspWksidService;
+    default:
+        return 0;
+    }
+}

src/launcher/launcher.c

@@ -16,10 +16,19 @@
  */
 
 #include <launcher/launcher.h>
+#include <aclapi.h>
 #include <sddl.h>
+#include <userenv.h>
 
 #define PROGNAME                        "WinFsp.Launcher"
 
+static NTSTATUS (NTAPI *SvcNtOpenSymbolicLinkObject)(
+    PHANDLE LinkHandle,
+    ACCESS_MASK DesiredAccess,
+    POBJECT_ATTRIBUTES ObjectAttributes);
+static NTSTATUS (NTAPI *SvcNtClose)(
+    HANDLE Handle);
+
 BOOL CreateOverlappedPipe(
     PHANDLE PReadPipe, PHANDLE PWritePipe,
     DWORD Size,
@@ -141,6 +150,201 @@ exit:
     return Result;
 }
 
+static NTSTATUS AddAccessForTokenUser(HANDLE Handle, DWORD Access, HANDLE Token)
+{
+    TOKEN_USER *User = 0;
+    PSECURITY_DESCRIPTOR SecurityDescriptor = 0;
+    PSECURITY_DESCRIPTOR NewSecurityDescriptor = 0;
+    EXPLICIT_ACCESSW AccessEntry;
+    DWORD Size, LastError;
+    NTSTATUS Result;
+
+    if (GetTokenInformation(Token, TokenUser, 0, 0, &Size))
+    {
+        Result = STATUS_INVALID_PARAMETER;
+        goto exit;
+    }
+    if (ERROR_INSUFFICIENT_BUFFER != GetLastError())
+    {
+        Result = FspNtStatusFromWin32(GetLastError());
+        goto exit;
+    }
+
+    User = MemAlloc(Size);
+    if (0 == User)
+    {
+        Result = STATUS_INSUFFICIENT_RESOURCES;
+        goto exit;
+    }
+
+    if (!GetTokenInformation(Token, TokenUser, User, Size, &Size))
+    {
+        Result = FspNtStatusFromWin32(GetLastError());
+        goto exit;
+    }
+
+    if (GetKernelObjectSecurity(Handle, DACL_SECURITY_INFORMATION, 0, 0, &Size))
+    {
+        Result = STATUS_INVALID_PARAMETER;
+        goto exit;
+    }
+    if (ERROR_INSUFFICIENT_BUFFER != GetLastError())
+    {
+        Result = FspNtStatusFromWin32(GetLastError());
+        goto exit;
+    }
+
+    SecurityDescriptor = MemAlloc(Size);
+    if (0 == SecurityDescriptor)
+    {
+        Result = STATUS_INSUFFICIENT_RESOURCES;
+        goto exit;
+    }
+
+    if (!GetKernelObjectSecurity(Handle, DACL_SECURITY_INFORMATION, SecurityDescriptor, Size, &Size))
+    {
+        Result = FspNtStatusFromWin32(GetLastError());
+        goto exit;
+    }
+
+    AccessEntry.grfAccessPermissions = Access;
+    AccessEntry.grfAccessMode = GRANT_ACCESS;
+    AccessEntry.grfInheritance = NO_INHERITANCE;
+    AccessEntry.Trustee.pMultipleTrustee = 0;
+    AccessEntry.Trustee.MultipleTrusteeOperation = NO_MULTIPLE_TRUSTEE;
+    AccessEntry.Trustee.TrusteeForm = TRUSTEE_IS_SID;
+    AccessEntry.Trustee.TrusteeType = TRUSTEE_IS_UNKNOWN;
+    AccessEntry.Trustee.ptstrName = User->User.Sid;
+
+    LastError = BuildSecurityDescriptorW(0, 0, 1, &AccessEntry, 0, 0, SecurityDescriptor,
+        &Size, &NewSecurityDescriptor);
+    if (0 != LastError)
+    {
+        Result = FspNtStatusFromWin32(LastError);
+        goto exit;
+    }
+
+    if (!SetKernelObjectSecurity(Handle, DACL_SECURITY_INFORMATION, NewSecurityDescriptor))
+    {
+        Result = FspNtStatusFromWin32(GetLastError());
+        goto exit;
+    }
+
+    Result = STATUS_SUCCESS;
+
+exit:
+    LocalFree(NewSecurityDescriptor);
+    MemFree(SecurityDescriptor);
+    MemFree(User);
+
+    return Result;
+}
+
+static BOOL LogonCreateProcess(
+    PWSTR UserName,
+    LPCWSTR ApplicationName,
+    LPWSTR CommandLine,
+    LPSECURITY_ATTRIBUTES ProcessAttributes,
+    LPSECURITY_ATTRIBUTES ThreadAttributes,
+    BOOL InheritHandles,
+    DWORD CreationFlags,
+    LPVOID Environment,
+    LPCWSTR CurrentDirectory,
+    LPSTARTUPINFOW StartupInfo,
+    LPPROCESS_INFORMATION ProcessInformation)
+{
+    PWSTR DomainName = 0;
+
+    if (0 != UserName)
+    {
+        if (0 == invariant_wcsicmp(UserName, L"LocalSystem"))
+            UserName = 0;
+        else
+        if (0 == invariant_wcsicmp(UserName, L"LocalService") ||
+            0 == invariant_wcsicmp(UserName, L"NetworkService"))
+            DomainName = L"NT AUTHORITY";
+        else
+        {
+            SetLastError(ERROR_ACCESS_DENIED);
+            return FALSE;
+        }
+    }
+
+    if (0 == UserName)
+        /* without a user name go ahead and call CreateProcessW */
+        return CreateProcessW(
+            ApplicationName,
+            CommandLine,
+            ProcessAttributes,
+            ThreadAttributes,
+            InheritHandles,
+            CreationFlags,
+            Environment,
+            CurrentDirectory,
+            StartupInfo,
+            ProcessInformation);
+
+    HANDLE LogonToken = 0;
+    PVOID EnvironmentBlock = 0;
+    DWORD LastError;
+    BOOL Success;
+
+    Success = LogonUserW(
+        UserName,
+        DomainName,
+        0,
+        LOGON32_LOGON_SERVICE,
+        LOGON32_PROVIDER_DEFAULT,
+        &LogonToken);
+    if (!Success)
+        goto exit;
+
+    if (0 == Environment)
+    {
+        Success = CreateEnvironmentBlock(&EnvironmentBlock, LogonToken, FALSE);
+        if (!Success)
+            goto exit;
+
+        CreationFlags |= CREATE_UNICODE_ENVIRONMENT;
+        Environment = EnvironmentBlock;
+    }
+
+    Success = ImpersonateLoggedOnUser(LogonToken);
+    if (!Success)
+        goto exit;
+
+    Success = CreateProcessAsUserW(
+        LogonToken,
+        ApplicationName,
+        CommandLine,
+        ProcessAttributes,
+        ThreadAttributes,
+        InheritHandles,
+        CreationFlags,
+        Environment,
+        CurrentDirectory,
+        StartupInfo,
+        ProcessInformation);
+
+    if (!RevertToSelf())
+        /* should not happen! */
+        ExitProcess(GetLastError());
+
+exit:
+    if (!Success)
+        LastError = GetLastError();
+
+    if (0 != EnvironmentBlock)
+        DestroyEnvironmentBlock(EnvironmentBlock);
+    if (0 != LogonToken)
+        CloseHandle(LogonToken);
+
+    if (!Success)
+        SetLastError(LastError);
+
+    return Success;
+}
+
 typedef struct
 {
     HANDLE Process;
@@ -352,6 +556,67 @@ static NTSTATUS SvcInstanceReplaceArguments(PWSTR String, ULONG Argc, PWSTR *Arg
     return STATUS_SUCCESS;
 }
 
+static NTSTATUS SvcInstanceAddUserRights(HANDLE Token,
+    PSECURITY_DESCRIPTOR SecurityDescriptor, PSECURITY_DESCRIPTOR *PNewSecurityDescriptor)
+{
+    PSECURITY_DESCRIPTOR NewSecurityDescriptor;
+    TOKEN_USER *User = 0;
+    EXPLICIT_ACCESSW AccessEntry;
+    DWORD Size, LastError;
+    NTSTATUS Result;
+
+    *PNewSecurityDescriptor = 0;
+
+    if (GetTokenInformation(Token, TokenUser, 0, 0, &Size))
+    {
+        Result = STATUS_INVALID_PARAMETER;
+        goto exit;
+    }
+    if (ERROR_INSUFFICIENT_BUFFER != GetLastError())
+    {
+        Result = FspNtStatusFromWin32(GetLastError());
+        goto exit;
+    }
+
+    User = MemAlloc(Size);
+    if (0 == User)
+    {
+        Result = STATUS_INSUFFICIENT_RESOURCES;
+        goto exit;
+    }
+
+    if (!GetTokenInformation(Token, TokenUser, User, Size, &Size))
+    {
+        Result = FspNtStatusFromWin32(GetLastError());
+        goto exit;
+    }
+
+    AccessEntry.grfAccessPermissions = SERVICE_QUERY_STATUS | SERVICE_STOP;
+    AccessEntry.grfAccessMode = GRANT_ACCESS;
+    AccessEntry.grfInheritance = NO_INHERITANCE;
+    AccessEntry.Trustee.pMultipleTrustee = 0;
+    AccessEntry.Trustee.MultipleTrusteeOperation = NO_MULTIPLE_TRUSTEE;
+    AccessEntry.Trustee.TrusteeForm = TRUSTEE_IS_SID;
+    AccessEntry.Trustee.TrusteeType = TRUSTEE_IS_UNKNOWN;
+    AccessEntry.Trustee.ptstrName = User->User.Sid;
+
+    LastError = BuildSecurityDescriptorW(0, 0, 1, &AccessEntry, 0, 0, SecurityDescriptor,
+        &Size, &NewSecurityDescriptor);
+    if (0 != LastError)
+    {
+        Result = FspNtStatusFromWin32(LastError);
+        goto exit;
+    }
+
+    *PNewSecurityDescriptor = NewSecurityDescriptor;
+    Result = STATUS_SUCCESS;
+
+exit:
+    MemFree(User);
+
+    return Result;
+}
+
 static NTSTATUS SvcInstanceAccessCheck(HANDLE ClientToken, ULONG DesiredAccess,
     PSECURITY_DESCRIPTOR SecurityDescriptor)
 {
@@ -380,7 +645,8 @@ static NTSTATUS SvcInstanceAccessCheck(HANDLE ClientToken, ULONG DesiredAccess,
     return Result;
 }
 
-NTSTATUS SvcInstanceCreateProcess(PWSTR Executable, PWSTR CommandLine,
+NTSTATUS SvcInstanceCreateProcess(PWSTR UserName,
+    PWSTR Executable, PWSTR CommandLine,
     HANDLE StdioHandles[2],
     PPROCESS_INFORMATION ProcessInfo)
 {
@@ -457,7 +723,8 @@ NTSTATUS SvcInstanceCreateProcess(PWSTR Executable, PWSTR CommandLine,
         StartupInfoEx.StartupInfo.hStdOutput = ChildHandles[1];
         StartupInfoEx.StartupInfo.hStdError = ChildHandles[2];
 
-        if (!CreateProcessW(Executable, CommandLine, 0, 0, TRUE,
+        if (!LogonCreateProcess(UserName,
+            Executable, CommandLine, 0, 0, TRUE,
             CREATE_SUSPENDED | CREATE_NEW_PROCESS_GROUP | EXTENDED_STARTUPINFO_PRESENT, 0, 0,
             &StartupInfoEx.StartupInfo, ProcessInfo))
         {
@@ -476,7 +743,8 @@ NTSTATUS SvcInstanceCreateProcess(PWSTR Executable, PWSTR CommandLine,
              * Not ideal, but...
              */
             StartupInfoEx.StartupInfo.cb = sizeof StartupInfoEx.StartupInfo;
-            if (!CreateProcessW(Executable, CommandLine, 0, 0, TRUE,
+            if (!LogonCreateProcess(UserName,
+                Executable, CommandLine, 0, 0, TRUE,
                 CREATE_SUSPENDED | CREATE_NEW_PROCESS_GROUP, 0, 0,
                 &StartupInfoEx.StartupInfo, ProcessInfo))
             {
@@ -487,7 +755,8 @@ NTSTATUS SvcInstanceCreateProcess(PWSTR Executable, PWSTR CommandLine,
     }
     else
     {
-        if (!CreateProcessW(Executable, CommandLine, 0, 0, FALSE,
+        if (!LogonCreateProcess(UserName,
+            Executable, CommandLine, 0, 0, FALSE,
             CREATE_SUSPENDED | CREATE_NEW_PROCESS_GROUP, 0, 0,
             &StartupInfoEx.StartupInfo, ProcessInfo))
         {
@@ -531,10 +800,10 @@ NTSTATUS SvcInstanceCreate(HANDLE ClientToken,
     HKEY RegKey = 0;
     DWORD RegResult, RegSize;
     DWORD ClassNameSize, InstanceNameSize;
-    WCHAR Executable[MAX_PATH], CommandLineBuf[512], SecurityBuf[512];
+    WCHAR Executable[MAX_PATH], CommandLineBuf[512], SecurityBuf[512], RunAsBuf[256];
     PWSTR CommandLine, Security;
     DWORD JobControl, Credentials;
-    PSECURITY_DESCRIPTOR SecurityDescriptor = 0;
+    PSECURITY_DESCRIPTOR SecurityDescriptor = 0, NewSecurityDescriptor;
     PWSTR Argv[10];
     PROCESS_INFORMATION ProcessInfo;
     NTSTATUS Result;
@@ -618,6 +887,16 @@ NTSTATUS SvcInstanceCreate(HANDLE ClientToken,
         goto exit;
     }
 
+    RegSize = sizeof RunAsBuf;
+    RunAsBuf[0] = L'\0';
+    RegResult = RegGetValueW(RegKey, ClassName, L"RunAs", RRF_RT_REG_SZ, 0,
+        RunAsBuf, &RegSize);
+    if (ERROR_SUCCESS != RegResult && ERROR_FILE_NOT_FOUND != RegResult)
+    {
+        Result = FspNtStatusFromWin32(RegResult);
+        goto exit;
+    }
+
     RegSize = sizeof JobControl;
     JobControl = 1; /* default is YES! */
     RegResult = RegGetValueW(RegKey, ClassName, L"JobControl", RRF_RT_REG_DWORD, 0,
@@ -649,6 +928,14 @@ NTSTATUS SvcInstanceCreate(HANDLE ClientToken,
     if (!NT_SUCCESS(Result))
         goto exit;
 
+    Result = SvcInstanceAddUserRights(ClientToken, SecurityDescriptor, &NewSecurityDescriptor);
+    if (!NT_SUCCESS(Result))
+        goto exit;
+    LocalFree(SecurityDescriptor);
+    SecurityDescriptor = NewSecurityDescriptor;
+
+    //FspDebugLogSD(__FUNCTION__ ": SDDL = %s\n", SecurityDescriptor);
+
     ClassNameSize = (lstrlenW(ClassName) + 1) * sizeof(WCHAR);
     InstanceNameSize = (lstrlenW(InstanceName) + 1) * sizeof(WCHAR);
 
@@ -673,7 +960,8 @@ NTSTATUS SvcInstanceCreate(HANDLE ClientToken,
     if (!NT_SUCCESS(Result))
         goto exit;
 
-    Result = SvcInstanceCreateProcess(Executable, SvcInstance->CommandLine,
+    Result = SvcInstanceCreateProcess(L'\0' != RunAsBuf[0] ? RunAsBuf : 0,
+        Executable, SvcInstance->CommandLine,
         RedirectStdio ? SvcInstance->StdioHandles : 0, &ProcessInfo);
     if (!NT_SUCCESS(Result))
         goto exit;
@@ -744,6 +1032,9 @@ exit:
 
     LeaveCriticalSection(&SvcInstanceLock);
 
+    FspServiceLog(EVENTLOG_INFORMATION_TYPE,
+        L"create %s\\%s = %lx", ClassName, InstanceName, Result);
+
     return Result;
 }
 
@@ -777,6 +1068,9 @@ static VOID CALLBACK SvcInstanceTerminated(PVOID Context, BOOLEAN Timeout)
 {
     SVC_INSTANCE *SvcInstance = Context;
 
+    FspServiceLog(EVENTLOG_INFORMATION_TYPE,
+        L"terminated %s\\%s", SvcInstance->ClassName, SvcInstance->InstanceName);
+
     SvcInstanceRelease(SvcInstance);
 }
 
@@ -1009,6 +1303,53 @@ NTSTATUS SvcInstanceStopAndWaitAll(VOID)
     return STATUS_SUCCESS;
 }
 
+NTSTATUS SvcDefineDosDevice(HANDLE ClientToken,
+    PWSTR DeviceName, PWSTR TargetPath)
+{
+    NTSTATUS Result;
+
+    if (L'+' != DeviceName[0] && L'-' != DeviceName[0])
+        return STATUS_INVALID_PARAMETER;
+
+    Result = FspServiceContextCheck(ClientToken, 0);
+    if (!NT_SUCCESS(Result))
+        return Result;
+
+    if (!DefineDosDeviceW(
+        DDD_RAW_TARGET_PATH |
+            (L'+' == DeviceName[0] ? 0 : DDD_REMOVE_DEFINITION | DDD_EXACT_MATCH_ON_REMOVE),
+        DeviceName + 1, TargetPath))
+        return FspNtStatusFromWin32(GetLastError());
+
+    if (L'+' == DeviceName[0] && 0 != SvcNtOpenSymbolicLinkObject)
+    {
+        /* The drive symlink now exists; add DELETE access to it for the ClientToken. */
+        WCHAR SymlinkBuf[6];
+        UNICODE_STRING Symlink;
+        OBJECT_ATTRIBUTES Obja;
+        HANDLE MountHandle;
+
+        memcpy(SymlinkBuf, L"\\??\\X:", sizeof SymlinkBuf);
+        SymlinkBuf[4] = DeviceName[1];
+        Symlink.Length = Symlink.MaximumLength = sizeof SymlinkBuf;
+        Symlink.Buffer = SymlinkBuf;
+
+        memset(&Obja, 0, sizeof Obja);
+        Obja.Length = sizeof Obja;
+        Obja.ObjectName = &Symlink;
+        Obja.Attributes = OBJ_CASE_INSENSITIVE;
+
+        Result = SvcNtOpenSymbolicLinkObject(&MountHandle, READ_CONTROL | WRITE_DAC, &Obja);
+        if (NT_SUCCESS(Result))
+        {
+            AddAccessForTokenUser(MountHandle, DELETE, ClientToken);
+            SvcNtClose(MountHandle);
+        }
+    }
+
+    return STATUS_SUCCESS;
+}
+
 static HANDLE SvcJob, SvcThread, SvcEvent;
 static DWORD SvcThreadId;
 static HANDLE SvcPipe = INVALID_HANDLE_VALUE;
@@ -1329,6 +1670,7 @@ static VOID SvcPipeTransact(HANDLE ClientToken, PWSTR PipeBuf, PULONG PSize)
 
     PWSTR P = PipeBuf, PipeBufEnd = PipeBuf + *PSize / sizeof(WCHAR);
     PWSTR ClassName, InstanceName, UserName;
+    PWSTR DeviceName, TargetPath;
     ULONG Argc; PWSTR Argv[9];
     BOOLEAN HasSecret = FALSE;
     NTSTATUS Result;
@@ -1390,6 +1732,17 @@ static VOID SvcPipeTransact(HANDLE ClientToken, PWSTR PipeBuf, PULONG PSize)
         SvcPipeTransactResult(Result, PipeBuf, PSize);
         break;
 
+    case LauncherDefineDosDevice:
+        DeviceName = SvcPipeTransactGetPart(&P, PipeBufEnd);
+        TargetPath = SvcPipeTransactGetPart(&P, PipeBufEnd);
+
+        Result = STATUS_INVALID_PARAMETER;
+        if (0 != DeviceName && 0 != TargetPath)
+            Result = SvcDefineDosDevice(ClientToken, DeviceName, TargetPath);
+
+        SvcPipeTransactResult(Result, PipeBuf, PSize);
+        break;
+
 #if !defined(NDEBUG)
     case LauncherQuit:
         SetEvent(SvcEvent);
@@ -1408,6 +1761,19 @@ static VOID SvcPipeTransact(HANDLE ClientToken, PWSTR PipeBuf, PULONG PSize)
 
 int wmain(int argc, wchar_t **argv)
 {
+    HANDLE Handle = GetModuleHandleW(L"ntdll.dll");
+    if (0 != Handle)
+    {
+        SvcNtOpenSymbolicLinkObject = (PVOID)GetProcAddress(Handle, "NtOpenSymbolicLinkObject");
+        SvcNtClose = (PVOID)GetProcAddress(Handle, "NtClose");
+
+        if (0 == SvcNtOpenSymbolicLinkObject || 0 == SvcNtClose)
+        {
+            SvcNtOpenSymbolicLinkObject = 0;
+            SvcNtClose = 0;
+        }
+    }
+
     return FspServiceRun(L"" PROGNAME, SvcStart, SvcStop, 0);
 }
 

src/launcher/launcher.h

@@ -29,7 +29,7 @@
 
 #define LAUNCHER_PIPE_NAME              "\\\\.\\pipe\\WinFsp.{14E7137D-22B4-437A-B0C1-D21D1BDF3767}"
 #define LAUNCHER_PIPE_BUFFER_SIZE       4096
-#define LAUNCHER_PIPE_DEFAULT_TIMEOUT   3000
+#define LAUNCHER_PIPE_DEFAULT_TIMEOUT   (2 * 15000 + 1000)
 
 #define LAUNCHER_START_WITH_SECRET_TIMEOUT 15000
 
@@ -62,6 +62,7 @@ enum
     LauncherSvcInstanceStop             = 'T',  /* requires: SERVICE_STOP */
     LauncherSvcInstanceInfo             = 'I',  /* requires: SERVICE_QUERY_STATUS */
     LauncherSvcInstanceList             = 'L',  /* requires: none*/
+    LauncherDefineDosDevice             = 'D',
     LauncherQuit                        = 'Q',  /* DEBUG version only */
 
     LauncherSuccess                     = '$',