update changelog

This fixes GitHub issue #177. All credit for the investigation and
suggested workaround goes to @thinkport.

Changelog.asciidoc

@@ -1,6 +1,42 @@
 = Changelog
 
 
+v1.4 (2019.1)::
+
+Changes since v1.3:
+
+* FUSE3 API (version 3.2) is now available. The FUSE2 API (version 2.8) also remains supported.
+* New `Control` file system operation allows sending custom control codes to the file system using the Windows `DeviceIoControl` API. FUSE `ioctl` is also supported.
+* New `SetDelete` file system operation can optionally be used instead of `CanDelete`. `SetDelete` or `CanDelete` are used to handle the file "disposition" flag, which determines if a file is marked for deletion. See the relevant documentation for more details.
+* `FlushAndPurgeOnCleanup` has now been added to the .NET API. (GitHub PR #176; thanks @FrKaram.)
+* The Launcher now supports running file systems under the user account that started them. Use `RunAs="."` in the file system registry entry.
+* New sample file system "airfs" contributed by @JohnOberschelp. Airfs is an in-memory file system like Memfs on which it is based on; it has received substantial improvements in how the file name space is maintained and has been modified to use modern C++ techniques by John.
+* New sample file system "passthrough-fuse3" passes all operations to an underlying file system. This file system is built using the FUSE3 API. It builds and runs on both Windows and Cygwin.
+* The FUSE layer now supports multiple file systems within a single process. This is a long standing problem that has been fixed. (GitHub issue #135.)
+* The FSD includes a fix for a Windows problem: that case-sensitive file systems do not work properly when mounted as directories. See FAQ entry #3.
+* The FSD includes a fix for a rare but serious problem. (GitHub issue #177. Thanks @thinkport.)
+* The FSD includes a fix for an incompatibility with DrWeb Antivirus. (GitHub issue #192)
+* The DLL includes a fix for an errorenous `STATUS_ACCESS_DENIED` on read-only directories. (GitHub issue #190. Thanks @alfaunits.)
+
+
+v1.4B4 (2018.2 B4)::
+
+Changes since v1.3:
+
+* FUSE3 API (version 3.2) is now available. The FUSE2 API (version 2.8) also remains supported.
+* New `Control` file system operation allows sending custom control codes to the file system using the Windows `DeviceIoControl` API. FUSE `ioctl` is also supported.
+* New `SetDelete` file system operation can optionally be used instead of `CanDelete`. `SetDelete` or `CanDelete` are used to handle the file "disposition" flag, which determines if a file is marked for deletion. See the relevant documentation for more details.
+* `FlushAndPurgeOnCleanup` has now been added to the .NET API. (GitHub PR #176; thanks @FrKaram.)
+* The Launcher now supports running file systems under the user account that started them. Use `RunAs="."` in the file system registry entry.
+* New sample file system "airfs" contributed by @JohnOberschelp. Airfs is an in-memory file system like Memfs on which it is based on; it has received substantial improvements in how the file name space is maintained and has been modified to use modern C++ techniques by John.
+* New sample file system "passthrough-fuse3" passes all operations to an underlying file system. This file system is built using the FUSE3 API. It builds and runs on both Windows and Cygwin.
+* The FUSE layer now supports multiple file systems within a single process. This is a long standing problem that has been fixed. (GitHub issue #135.)
+* The FSD includes a fix for a Windows problem: that case-sensitive file systems do not work properly when mounted as directories. See FAQ entry #3.
+* The FSD includes a fix for a rare but serious problem. (GitHub issue #177. Thanks @thinkport.)
+* The FSD includes a fix for an incompatibility with DrWeb Antivirus. (GitHub issue #192)
+* The DLL includes a fix for an errorenous `STATUS_ACCESS_DENIED` on read-only directories. (GitHub issue #190. Thanks @alfaunits.)
+
+
 v1.4B3 (2018.2 B3)::
 
 Changes since v1.3:

build/VStudio/version.properties

@@ -18,8 +18,8 @@
 
         <MyCanonicalVersion>1.4</MyCanonicalVersion>
 
-        <MyProductVersion>2018.2 B3</MyProductVersion>
-        <MyProductStage>Beta</MyProductStage>
+        <MyProductVersion>2019.1</MyProductVersion>
+        <MyProductStage>Gold</MyProductStage>
 
         <MyVersion>$(MyCanonicalVersion).$(MyBuildNumber)</MyVersion>
         <MyVersionWithCommas>$(MyVersion.Replace('.',',')),0</MyVersionWithCommas>

build/VStudio/winfsp_dll.vcxproj

@@ -222,7 +222,7 @@ copy /b $(OutDir)fuse3-$(PlatformTarget).pc + %(FullPath) $(OutDir)fuse3-$(Platf
       <MapFileName>$(OutDir)$(TargetFileName).map</MapFileName>
       <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
       <ModuleDefinitionFile>..\..\src\dll\library.def</ModuleDefinitionFile>
-      <AdditionalDependencies>%(AdditionalDependencies);rpcrt4.lib;credui.lib;version.lib</AdditionalDependencies>
+      <AdditionalDependencies>%(AdditionalDependencies);rpcrt4.lib;credui.lib;secur32.lib;version.lib</AdditionalDependencies>
       <StripPrivateSymbols>$(OutDir)$(TargetFileName).public.pdb</StripPrivateSymbols>
     </Link>
   </ItemDefinitionGroup>
@@ -250,7 +250,7 @@ copy /b $(OutDir)fuse3-$(PlatformTarget).pc + %(FullPath) $(OutDir)fuse3-$(Platf
       <MapFileName>$(OutDir)$(TargetFileName).map</MapFileName>
       <IgnoreAllDefaultLibraries>true</IgnoreAllDefaultLibraries>
       <ModuleDefinitionFile>..\..\src\dll\library.def</ModuleDefinitionFile>
-      <AdditionalDependencies>%(AdditionalDependencies);rpcrt4.lib;credui.lib;version.lib</AdditionalDependencies>
+      <AdditionalDependencies>%(AdditionalDependencies);rpcrt4.lib;credui.lib;secur32.lib;version.lib</AdditionalDependencies>
       <StripPrivateSymbols>$(OutDir)$(TargetFileName).public.pdb</StripPrivateSymbols>
     </Link>
   </ItemDefinitionGroup>
@@ -281,7 +281,7 @@ copy /b $(OutDir)fuse3-$(PlatformTarget).pc + %(FullPath) $(OutDir)fuse3-$(Platf
       <MapFileName>$(OutDir)$(TargetFileName).map</MapFileName>
       <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
       <ModuleDefinitionFile>..\..\src\dll\library.def</ModuleDefinitionFile>
-      <AdditionalDependencies>%(AdditionalDependencies);rpcrt4.lib;credui.lib;version.lib</AdditionalDependencies>
+      <AdditionalDependencies>%(AdditionalDependencies);rpcrt4.lib;credui.lib;secur32.lib;version.lib</AdditionalDependencies>
       <StripPrivateSymbols>$(OutDir)$(TargetFileName).public.pdb</StripPrivateSymbols>
     </Link>
   </ItemDefinitionGroup>
@@ -312,7 +312,7 @@ copy /b $(OutDir)fuse3-$(PlatformTarget).pc + %(FullPath) $(OutDir)fuse3-$(Platf
       <MapFileName>$(OutDir)$(TargetFileName).map</MapFileName>
       <IgnoreAllDefaultLibraries>true</IgnoreAllDefaultLibraries>
       <ModuleDefinitionFile>..\..\src\dll\library.def</ModuleDefinitionFile>
-      <AdditionalDependencies>%(AdditionalDependencies);rpcrt4.lib;credui.lib;version.lib</AdditionalDependencies>
+      <AdditionalDependencies>%(AdditionalDependencies);rpcrt4.lib;credui.lib;secur32.lib;version.lib</AdditionalDependencies>
       <StripPrivateSymbols>$(OutDir)$(TargetFileName).public.pdb</StripPrivateSymbols>
     </Link>
   </ItemDefinitionGroup>

inc/winfsp/launch.h

@@ -111,7 +111,43 @@ enum
  */
 FSP_API NTSTATUS FspLaunchCallLauncherPipe(
     WCHAR Command, ULONG Argc, PWSTR *Argv, ULONG *Argl,
-    PWSTR Buffer, PULONG PSize, PULONG PLauncherError);
+    PWSTR Buffer, PULONG PSize,
+    PULONG PLauncherError);
+/**
+ * Call launcher pipe.
+ *
+ * This function is used to send a command to the launcher and receive a response.
+ *
+ * @param Command
+ *     Launcher command to send. For example, the 'L' launcher command instructs
+ *     the launcher to list all running service instances.
+ * @param Argc
+ *     Command argument count. May be 0.
+ * @param Argv
+ *     Command argument array. May be NULL.
+ * @param Argl
+ *     Command argument length array. May be NULL. If this is NULL all command arguments
+ *     are assumed to be NULL-terminated strings. It is also possible for specific arguments
+ *     to be NULL-terminated; in this case pass -1 in the corresponding Argl position.
+ * @param Buffer
+ *     Buffer that receives the command response. May be NULL.
+ * @param PSize
+ *     Pointer to a ULONG. On input it contains the size of the Buffer. On output it
+ *     contains the number of bytes transferred. May be NULL.
+ * @param AllowImpersonation
+ *     Allow caller to be impersonated by launcher.
+ * @param PLauncherError
+ *     Receives the launcher error if any. This is always a Win32 error code. May not be NULL.
+ * @return
+ *     STATUS_SUCCESS if the command is sent successfully to the launcher, even if the launcher
+ *     returns an error. Other status codes indicate a communication error. Launcher errors are
+ *     reported through PLauncherError.
+ */
+FSP_API NTSTATUS FspLaunchCallLauncherPipeEx(
+    WCHAR Command, ULONG Argc, PWSTR *Argv, ULONG *Argl,
+    PWSTR Buffer, PULONG PSize,
+    BOOLEAN AllowImpersonation,
+    PULONG PLauncherError);
 /**
  * Start a service instance.
  *
@@ -138,6 +174,35 @@ FSP_API NTSTATUS FspLaunchStart(
     PWSTR ClassName, PWSTR InstanceName, ULONG Argc, PWSTR *Argv,
     BOOLEAN HasSecret,
     PULONG PLauncherError);
+/**
+ * Start a service instance.
+ *
+ * @param ClassName
+ *     Class name of the service instance to start.
+ * @param InstanceName
+ *     Instance name of the service instance to start.
+ * @param Argc
+ *     Service instance argument count. May be 0.
+ * @param Argv
+ *     Service instance argument array. May be NULL.
+ * @param HasSecret
+ *     Whether the last argument in Argv is assumed to be a secret (e.g. password) or not.
+ *     Secrets are passed to service instances through standard input rather than the command
+ *     line.
+ * @param AllowImpersonation
+ *     Allow caller to be impersonated by launcher.
+ * @param PLauncherError
+ *     Receives the launcher error if any. This is always a Win32 error code. May not be NULL.
+ * @return
+ *     STATUS_SUCCESS if the command is sent successfully to the launcher, even if the launcher
+ *     returns an error. Other status codes indicate a communication error. Launcher errors are
+ *     reported through PLauncherError.
+ */
+FSP_API NTSTATUS FspLaunchStartEx(
+    PWSTR ClassName, PWSTR InstanceName, ULONG Argc, PWSTR *Argv,
+    BOOLEAN HasSecret,
+    BOOLEAN AllowImpersonation,
+    PULONG PLauncherError);
 /**
  * Stop a service instance.
  *
@@ -221,10 +286,12 @@ typedef struct _FSP_LAUNCH_REG_RECORD
     PWSTR WorkDirectory;
     PWSTR RunAs;
     PWSTR Security;
-    PVOID Reserved0[6];
+    PWSTR AuthPackage;
+    PVOID Reserved0[5];
     ULONG JobControl;
     ULONG Credentials;
-    ULONG Reserved1[6];
+    ULONG AuthPackageId;
+    ULONG Reserved1[5];
     UINT8 Buffer[];
 } FSP_LAUNCH_REG_RECORD;
 #pragma warning(pop)

inc/winfsp/winfsp.h

@@ -1795,6 +1795,10 @@ FSP_API NTSTATUS FspCallNamedPipeSecurely(PWSTR PipeName,
     PVOID InBuffer, ULONG InBufferSize, PVOID OutBuffer, ULONG OutBufferSize,
     PULONG PBytesTransferred, ULONG Timeout,
     PSID Sid);
+FSP_API NTSTATUS FspCallNamedPipeSecurelyEx(PWSTR PipeName,
+    PVOID InBuffer, ULONG InBufferSize, PVOID OutBuffer, ULONG OutBufferSize,
+    PULONG PBytesTransferred, ULONG Timeout, BOOLEAN AllowImpersonation,
+    PSID Sid);
 FSP_API NTSTATUS FspVersion(PUINT32 PVersion);
 
 /*

src/dll/launch.c

@@ -23,7 +23,18 @@
 
 FSP_API NTSTATUS FspLaunchCallLauncherPipe(
     WCHAR Command, ULONG Argc, PWSTR *Argv, ULONG *Argl,
-    PWSTR Buffer, PULONG PSize, PULONG PLauncherError)
+    PWSTR Buffer, PULONG PSize,
+    PULONG PLauncherError)
+{
+    return FspLaunchCallLauncherPipeEx(
+        Command, Argc, Argv, Argl, Buffer, PSize, FALSE, PLauncherError);
+}
+
+FSP_API NTSTATUS FspLaunchCallLauncherPipeEx(
+    WCHAR Command, ULONG Argc, PWSTR *Argv, ULONG *Argl,
+    PWSTR Buffer, PULONG PSize,
+    BOOLEAN AllowImpersonation,
+    PULONG PLauncherError)
 {
     PWSTR PipeBuf = 0, P;
     ULONG Length, BytesTransferred;
@@ -53,9 +64,9 @@ FSP_API NTSTATUS FspLaunchCallLauncherPipe(
             memcpy(P, Argv[I], Length * sizeof(WCHAR)); P += Length; *P++ = L'\0';
         }
 
-    Result = FspCallNamedPipeSecurely(L"" FSP_LAUNCH_PIPE_NAME,
+    Result = FspCallNamedPipeSecurelyEx(L"" FSP_LAUNCH_PIPE_NAME,
         PipeBuf, (ULONG)(P - PipeBuf) * sizeof(WCHAR), PipeBuf, FSP_LAUNCH_PIPE_BUFFER_SIZE,
-        &BytesTransferred, NMPWAIT_USE_DEFAULT_WAIT, FSP_LAUNCH_PIPE_OWNER);
+        &BytesTransferred, NMPWAIT_USE_DEFAULT_WAIT, AllowImpersonation, FSP_LAUNCH_PIPE_OWNER);
     if (!NT_SUCCESS(Result))
         goto exit;
 
@@ -102,8 +113,17 @@ exit:
 }
 
 FSP_API NTSTATUS FspLaunchStart(
+    PWSTR ClassName, PWSTR InstanceName, ULONG Argc, PWSTR *Argv,
+    BOOLEAN HasSecret,
+    PULONG PLauncherError)
+{
+    return FspLaunchStartEx(ClassName, InstanceName, Argc, Argv, HasSecret, FALSE, PLauncherError);
+}
+
+FSP_API NTSTATUS FspLaunchStartEx(
     PWSTR ClassName, PWSTR InstanceName, ULONG Argc, PWSTR *Argv0,
     BOOLEAN HasSecret,
+    BOOLEAN AllowImpersonation,
     PULONG PLauncherError)
 {
     PWSTR Argv[9 + 2];
@@ -115,9 +135,9 @@ FSP_API NTSTATUS FspLaunchStart(
     Argv[1] = InstanceName;
     memcpy(Argv + 2, Argv0, Argc * sizeof(PWSTR));
 
-    return FspLaunchCallLauncherPipe(
+    return FspLaunchCallLauncherPipeEx(
         HasSecret ? FspLaunchCmdStartWithSecret : FspLaunchCmdStart,
-        Argc + 2, Argv, 0, 0, 0, PLauncherError);
+        Argc + 2, Argv, 0, 0, 0, AllowImpersonation, PLauncherError);
 }
 
 FSP_API NTSTATUS FspLaunchStop(
@@ -250,8 +270,10 @@ FSP_API NTSTATUS FspLaunchRegSetRecord(
         SETFIELD(WorkDirectory);
         SETFIELD(RunAs);
         SETFIELD(Security);
+        SETFIELD(AuthPackage);
         SETFIELDI(JobControl, ~0); /* JobControl default is 1; but we treat as without default */
         SETFIELDI(Credentials, 0);
+        SETFIELDI(AuthPackageId, 0);
     }
     else
     {
@@ -400,8 +422,10 @@ FSP_API NTSTATUS FspLaunchRegGetRecord(
     GETFIELD(WorkDirectory);
     GETFIELD(RunAs);
     GETFIELD(Security);
+    GETFIELD(AuthPackage);
     GETFIELDI(JobControl);
     GETFIELDI(Credentials);
+    GETFIELDI(AuthPackageId);
 
     if (0 == Record->Executable)
     {
@@ -430,8 +454,11 @@ FSP_API NTSTATUS FspLaunchRegGetRecord(
         (PVOID)(Record->Buffer + ((PUINT8)RecordBuf.RunAs - RegBuf)) : 0;
     Record->Security = 0 != RecordBuf.Security ?
         (PVOID)(Record->Buffer + ((PUINT8)RecordBuf.Security - RegBuf)) : 0;
+    Record->AuthPackage = 0 != RecordBuf.AuthPackage ?
+        (PVOID)(Record->Buffer + ((PUINT8)RecordBuf.AuthPackage - RegBuf)) : 0;
     Record->JobControl = RecordBuf.JobControl;
     Record->Credentials = RecordBuf.Credentials;
+    Record->AuthPackageId = RecordBuf.AuthPackageId;
 
     *PRecord = Record;
     Result = STATUS_SUCCESS;

src/dll/library.c

@@ -46,6 +46,7 @@ BOOL WINAPI DllMain(HINSTANCE Instance, DWORD Reason, PVOID Reserved)
         Dynamic = 0 == Reserved;
         fsp_fuse_finalize(Dynamic);
         FspServiceFinalize(Dynamic);
+        FspFileSystemFinalize(Dynamic);
         FspEventLogFinalize(Dynamic);
         FspPosixFinalize(Dynamic);
         FspWksidFinalize(Dynamic);

src/dll/library.h

@@ -47,6 +47,7 @@
 VOID FspWksidFinalize(BOOLEAN Dynamic);
 VOID FspPosixFinalize(BOOLEAN Dynamic);
 VOID FspEventLogFinalize(BOOLEAN Dynamic);
+VOID FspFileSystemFinalize(BOOLEAN Dynamic);
 VOID FspServiceFinalize(BOOLEAN Dynamic);
 VOID fsp_fuse_finalize(BOOLEAN Dynamic);
 VOID fsp_fuse_finalize_thread(VOID);

src/dll/np.c

@@ -23,6 +23,9 @@
 #include <npapi.h>
 #include <wincred.h>
 
+#define _NTDEF_
+#include <ntsecapi.h>
+
 #define FSP_NP_NAME                     LIBRARY_NAME ".Np"
 #define FSP_NP_TYPE                     ' spF'  /* pick a value hopefully not in use */
 #define FSP_NP_ADDCONNECTION_TIMEOUT    15000
@@ -179,12 +182,14 @@ static inline BOOLEAN FspNpParseRemoteUserName(PWSTR RemoteName,
 
 static inline DWORD FspNpCallLauncherPipe(
     WCHAR Command, ULONG Argc, PWSTR *Argv, ULONG *Argl,
-    PWSTR Buffer, PULONG PSize)
+    PWSTR Buffer, PULONG PSize,
+    BOOLEAN AllowImpersonation)
 {
     NTSTATUS Result;
     ULONG ErrorCode;
 
-    Result = FspLaunchCallLauncherPipe(Command, Argc, Argv, Argl, Buffer, PSize, &ErrorCode);
+    Result = FspLaunchCallLauncherPipeEx(Command, Argc, Argv, Argl, Buffer, PSize, AllowImpersonation,
+        &ErrorCode);
     return !NT_SUCCESS(Result) ?
         WN_NO_NETWORK :
         (ERROR_BROKEN_PIPE == ErrorCode ? WN_NO_NETWORK : ErrorCode);
@@ -251,7 +256,50 @@ static WCHAR FspNpGetDriveLetter(PDWORD PLogicalDrives, PWSTR VolumeName)
     return 0;
 }
 
-static DWORD FspNpGetRemoteInfo(PWSTR RemoteName, PDWORD PCredentialsKind)
+static NTSTATUS FspNpGetAuthPackage(PWSTR AuthPackageName, PULONG PAuthPackage)
+{
+    HANDLE LsaHandle;
+    BOOLEAN LsaHandleValid = FALSE;
+    CHAR LsaAuthPackageNameBuf[127]; /* "The package name must not exceed 127 bytes in length." */
+    LSA_STRING LsaAuthPackageName;
+    ULONG AuthPackage;
+    NTSTATUS Result;
+
+    *PAuthPackage = 0;
+
+    Result = LsaConnectUntrusted(&LsaHandle);
+    if (!NT_SUCCESS(Result))
+        goto exit;
+    LsaHandleValid = TRUE;
+
+    LsaAuthPackageName.MaximumLength = sizeof LsaAuthPackageNameBuf;
+    LsaAuthPackageName.Buffer = LsaAuthPackageNameBuf;
+    LsaAuthPackageName.Length = WideCharToMultiByte(CP_UTF8, 0,
+        AuthPackageName, lstrlenW(AuthPackageName),
+        LsaAuthPackageNameBuf, sizeof LsaAuthPackageNameBuf,
+        0, 0);
+    if (0 == LsaAuthPackageName.Length)
+    {
+        Result = FspNtStatusFromWin32(GetLastError());
+        goto exit;
+    }
+
+    Result = LsaLookupAuthenticationPackage(LsaHandle, &LsaAuthPackageName, &AuthPackage);
+    if (!NT_SUCCESS(Result))
+        goto exit;
+
+    *PAuthPackage = AuthPackage;
+    Result = STATUS_SUCCESS;
+
+exit:
+    if (LsaHandleValid)
+        LsaDeregisterLogonProcess(LsaHandle);
+
+    return Result;
+}
+
+static DWORD FspNpGetRemoteInfo(PWSTR RemoteName,
+    PDWORD PAuthPackage, PDWORD PCredentialsKind, PBOOLEAN PAllowImpersonation)
 {
     PWSTR ClassName, InstanceName;
     ULONG ClassNameLen, InstanceNameLen;
@@ -259,7 +307,14 @@ static DWORD FspNpGetRemoteInfo(PWSTR RemoteName, PDWORD PCredentialsKind)
     FSP_LAUNCH_REG_RECORD *Record;
     NTSTATUS Result;
 
-    *PCredentialsKind = FSP_NP_CREDENTIALS_NONE;
+    if (0 != PAuthPackage)
+        *PAuthPackage = 0;
+
+    if (0 != PCredentialsKind)
+        *PCredentialsKind = FSP_NP_CREDENTIALS_NONE;
+
+    if (0 != PAllowImpersonation)
+        *PAllowImpersonation = FALSE;
 
     if (!FspNpParseRemoteName(RemoteName,
         &ClassName, &ClassNameLen, &InstanceName, &InstanceNameLen))
@@ -274,15 +329,36 @@ static DWORD FspNpGetRemoteInfo(PWSTR RemoteName, PDWORD PCredentialsKind)
     if (!NT_SUCCESS(Result))
         return WN_NO_NETWORK;
 
-    switch (Record->Credentials)
+    if (0 != PAuthPackage)
     {
-    case FSP_NP_CREDENTIALS_NONE:
-    case FSP_NP_CREDENTIALS_PASSWORD:
-    case FSP_NP_CREDENTIALS_USERPASS:
-        *PCredentialsKind = Record->Credentials;
-        break;
+        if (0 != Record->AuthPackage)
+        {
+            ULONG AuthPackage = 0;
+
+            Result = FspNpGetAuthPackage(Record->AuthPackage, &AuthPackage);
+            if (!NT_SUCCESS(Result))
+                return WN_NO_NETWORK;
+
+            *PAuthPackage = AuthPackage + 1;            /* ensure non-0 (Negotiate AuthPackage == 0) */
+        }
+        else if (0 != Record->AuthPackageId)
+            *PAuthPackage = Record->AuthPackageId + 1;  /* ensure non-0 (Negotiate AuthPackage == 0) */
     }
 
+    if (0 != PCredentialsKind)
+        switch (Record->Credentials)
+        {
+        case FSP_NP_CREDENTIALS_NONE:
+        case FSP_NP_CREDENTIALS_PASSWORD:
+        case FSP_NP_CREDENTIALS_USERPASS:
+            *PCredentialsKind = Record->Credentials;
+            break;
+        }
+
+    if (0 != PAllowImpersonation)
+        *PAllowImpersonation = 0 != Record->RunAs &&
+            L'.' == Record->RunAs[0] && L'\0' == Record->RunAs[1];
+
     FspLaunchRegFreeRecord(Record);
 
     return WN_SUCCESS;
@@ -290,7 +366,7 @@ static DWORD FspNpGetRemoteInfo(PWSTR RemoteName, PDWORD PCredentialsKind)
 
 static DWORD FspNpGetCredentials(
     HWND hwndOwner, PWSTR Caption, DWORD PrevNpResult,
-    DWORD CredentialsKind,
+    DWORD AuthPackage0, DWORD CredentialsKind,
     PBOOL PSave,
     PWSTR UserName, ULONG UserNameSize/* in chars */,
     PWSTR Password, ULONG PasswordSize/* in chars */)
@@ -317,7 +393,7 @@ static DWORD FspNpGetCredentials(
         (FSP_NP_CREDENTIALS_PASSWORD == CredentialsKind ? 0/*CREDUI_FLAGS_KEEP_USERNAME*/ : 0));
 #else
     WCHAR Domain[CREDUI_MAX_DOMAIN_TARGET_LENGTH + 1];
-    ULONG AuthPackage = 0;
+    ULONG AuthPackage = 0 != AuthPackage0 ? AuthPackage0 - 1 : 0;
     PVOID InAuthBuf = 0, OutAuthBuf = 0;
     ULONG InAuthSize, OutAuthSize, DomainSize;
 
@@ -346,7 +422,8 @@ static DWORD FspNpGetCredentials(
 
     NpResult = CredUIPromptForWindowsCredentialsW(&UiInfo, PrevNpResult,
         &AuthPackage, InAuthBuf, InAuthSize, &OutAuthBuf, &OutAuthSize, PSave,
-        CREDUIWIN_GENERIC | (0 != PSave ? CREDUIWIN_CHECKBOX : 0));
+        (0 != AuthPackage0 ? CREDUIWIN_AUTHPACKAGE_ONLY : CREDUIWIN_GENERIC) |
+            (0 != PSave ? CREDUIWIN_CHECKBOX : 0));
     if (ERROR_SUCCESS != NpResult)
         goto exit;
 
@@ -464,6 +541,7 @@ DWORD APIENTRY NPAddConnection(LPNETRESOURCEW lpNetResource, LPWSTR lpPassword,
     PWSTR ClassName, InstanceName, RemoteName, P;
     ULONG ClassNameLen, InstanceNameLen;
     DWORD CredentialsKind;
+    BOOLEAN AllowImpersonation;
     ULONG Argc;
     PWSTR Argv[6];
     ULONG Argl[6];
@@ -493,7 +571,7 @@ DWORD APIENTRY NPAddConnection(LPNETRESOURCEW lpNetResource, LPWSTR lpPassword,
             return WN_ALREADY_CONNECTED;
     }
 
-    NpResult = FspNpGetRemoteInfo(lpRemoteName, &CredentialsKind);
+    NpResult = FspNpGetRemoteInfo(lpRemoteName, 0, &CredentialsKind, &AllowImpersonation);
     if (WN_SUCCESS != NpResult)
         return NpResult;
 
@@ -550,7 +628,8 @@ DWORD APIENTRY NPAddConnection(LPNETRESOURCEW lpNetResource, LPWSTR lpPassword,
 
     NpResult = FspNpCallLauncherPipe(
         FSP_NP_CREDENTIALS_NONE != CredentialsKind ? FspLaunchCmdStartWithSecret : FspLaunchCmdStart,
-        Argc, Argv, Argl, 0, 0);
+        Argc, Argv, Argl, 0, 0,
+        AllowImpersonation);
     switch (NpResult)
     {
     case WN_SUCCESS:
@@ -602,7 +681,8 @@ DWORD APIENTRY NPAddConnection(LPNETRESOURCEW lpNetResource, LPWSTR lpPassword,
 
                 if (WN_SUCCESS != FspNpCallLauncherPipe(
                     FspLaunchCmdGetInfo,
-                    Argc, Argv, Argl, 0, 0))
+                    Argc, Argv, Argl, 0, 0,
+                    FALSE))
                 {
                     /* looks like the file system is gone! */
                     NpResult = WN_NO_NETWORK;
@@ -659,7 +739,7 @@ DWORD APIENTRY NPAddConnection3(HWND hwndOwner,
 {
     DWORD NpResult;
     PWSTR RemoteName = lpNetResource->lpRemoteName;
-    DWORD CredentialsKind;
+    DWORD AuthPackage, CredentialsKind;
     WCHAR UserName[CREDUI_MAX_USERNAME_LENGTH + 1], Password[CREDUI_MAX_PASSWORD_LENGTH + 1];
 #if defined(FSP_NP_CREDENTIAL_MANAGER)
     BOOL Save = TRUE;
@@ -679,7 +759,7 @@ DWORD APIENTRY NPAddConnection3(HWND hwndOwner,
             return NpResult;
     }
 
-    NpResult = FspNpGetRemoteInfo(RemoteName, &CredentialsKind);
+    NpResult = FspNpGetRemoteInfo(RemoteName, &AuthPackage, &CredentialsKind, 0);
     if (WN_SUCCESS != NpResult)
         return NpResult;
     if (FSP_NP_CREDENTIALS_NONE == CredentialsKind)
@@ -695,7 +775,7 @@ DWORD APIENTRY NPAddConnection3(HWND hwndOwner,
     {
         NpResult = FspNpGetCredentials(
             hwndOwner, RemoteName, NpResult,
-            CredentialsKind,
+            AuthPackage, CredentialsKind,
 #if defined(FSP_NP_CREDENTIAL_MANAGER)
             &Save,
 #else
@@ -766,7 +846,8 @@ DWORD APIENTRY NPCancelConnection(LPWSTR lpName, BOOL fForce)
 
     NpResult = FspNpCallLauncherPipe(
         FspLaunchCmdStop,
-        Argc, Argv, Argl, 0, 0);
+        Argc, Argv, Argl, 0, 0,
+        FALSE);
     switch (NpResult)
     {
     case WN_SUCCESS:

src/dll/security.c

@@ -341,26 +341,25 @@ FSP_API NTSTATUS FspAccessCheckEx(FSP_FILE_SYSTEM *FileSystem,
 
     if (Request->Req.Create.UserMode)
     {
-        if (0 != (FileAttributes & FILE_ATTRIBUTE_READONLY))
+        if (FILE_ATTRIBUTE_READONLY == (FileAttributes & (FILE_ATTRIBUTE_READONLY | FILE_ATTRIBUTE_DIRECTORY)) &&
+            (DesiredAccess & (FILE_WRITE_DATA | FILE_APPEND_DATA | FILE_ADD_SUBDIRECTORY | FILE_DELETE_CHILD)))
         {
-            if (DesiredAccess &
-                (FILE_WRITE_DATA | FILE_APPEND_DATA | FILE_ADD_SUBDIRECTORY | FILE_DELETE_CHILD))
-            {
-                Result = STATUS_ACCESS_DENIED;
-                goto exit;
-            }
-            if (Request->Req.Create.CreateOptions & FILE_DELETE_ON_CLOSE)
-            {
-                Result = STATUS_CANNOT_DELETE;
-                goto exit;
-            }
+            Result = STATUS_ACCESS_DENIED;
+            goto exit;
+        }
+
+        if (FILE_ATTRIBUTE_READONLY == (FileAttributes & FILE_ATTRIBUTE_READONLY) &&
+            (Request->Req.Create.CreateOptions & FILE_DELETE_ON_CLOSE))
+        {
+            Result = STATUS_CANNOT_DELETE;
+            goto exit;
         }
 
         if (0 == SecurityDescriptorSize)
             *PGrantedAccess = (MAXIMUM_ALLOWED & DesiredAccess) ?
                 FspFileGenericMapping.GenericAll : DesiredAccess;
 
-        if (0 != (FileAttributes & FILE_ATTRIBUTE_READONLY) &&
+        if (FILE_ATTRIBUTE_READONLY == (FileAttributes & (FILE_ATTRIBUTE_READONLY | FILE_ATTRIBUTE_DIRECTORY)) &&
             0 != (MAXIMUM_ALLOWED & DesiredAccess))
             *PGrantedAccess &= ~(FILE_WRITE_DATA | FILE_APPEND_DATA |
                 FILE_ADD_SUBDIRECTORY | FILE_DELETE_CHILD);

src/dll/util.c

@@ -67,6 +67,16 @@ FSP_API NTSTATUS FspCallNamedPipeSecurely(PWSTR PipeName,
     PVOID InBuffer, ULONG InBufferSize, PVOID OutBuffer, ULONG OutBufferSize,
     PULONG PBytesTransferred, ULONG Timeout,
     PSID Sid)
+{
+    return FspCallNamedPipeSecurelyEx(PipeName,
+        InBuffer, InBufferSize, OutBuffer, OutBufferSize, PBytesTransferred, Timeout,
+        FALSE, Sid);
+}
+
+FSP_API NTSTATUS FspCallNamedPipeSecurelyEx(PWSTR PipeName,
+    PVOID InBuffer, ULONG InBufferSize, PVOID OutBuffer, ULONG OutBufferSize,
+    PULONG PBytesTransferred, ULONG Timeout, BOOLEAN AllowImpersonation,
+    PSID Sid)
 {
     NTSTATUS Result;
     HANDLE Pipe = INVALID_HANDLE_VALUE;
@@ -75,7 +85,8 @@ FSP_API NTSTATUS FspCallNamedPipeSecurely(PWSTR PipeName,
     Pipe = CreateFileW(PipeName,
         GENERIC_READ | FILE_WRITE_DATA | FILE_WRITE_ATTRIBUTES,
         FILE_SHARE_READ | FILE_SHARE_WRITE, 0, OPEN_EXISTING,
-        SECURITY_SQOS_PRESENT | SECURITY_IDENTIFICATION, 0);
+        SECURITY_SQOS_PRESENT | (AllowImpersonation ? SECURITY_IMPERSONATION : SECURITY_IDENTIFICATION),
+        0);
     if (INVALID_HANDLE_VALUE == Pipe)
     {
         if (ERROR_PIPE_BUSY != GetLastError())
@@ -89,7 +100,8 @@ FSP_API NTSTATUS FspCallNamedPipeSecurely(PWSTR PipeName,
         Pipe = CreateFileW(PipeName,
             GENERIC_READ | FILE_WRITE_DATA | FILE_WRITE_ATTRIBUTES,
             FILE_SHARE_READ | FILE_SHARE_WRITE, 0, OPEN_EXISTING,
-            SECURITY_SQOS_PRESENT | SECURITY_IDENTIFICATION, 0);
+            SECURITY_SQOS_PRESENT | (AllowImpersonation ? SECURITY_IMPERSONATION : SECURITY_IDENTIFICATION),
+            0);
         if (INVALID_HANDLE_VALUE == Pipe)
         {
             Result = FspNtStatusFromWin32(GetLastError());

src/dotnet/FileSystemBase.cs

@@ -707,7 +707,7 @@ namespace Fsp
         /// Describes the modifications to apply to the file or directory security descriptor.
         /// </param>
         /// <returns>STATUS_SUCCESS or error code.</returns>
-        /// <seealso cref="ModifySecurityDescriptor"/>
+        /// <seealso cref="ModifySecurityDescriptorEx"/>
         public virtual Int32 SetSecurity(
             Object FileNode,
             Object FileDesc,
@@ -1105,7 +1105,7 @@ namespace Fsp
             return (int)Api.FspFileSystemOperationProcessId();
         }
         /// <summary>
-        /// Modifies a security descriptor.
+        /// Modifies a security descriptor. [OBSOLETE]
         /// </summary>
         /// <remarks>
         /// This is a helper for implementing the SetSecurity operation.
@@ -1121,6 +1121,7 @@ namespace Fsp
         /// </param>
         /// <returns>The modified security descriptor.</returns>
         /// <seealso cref="SetSecurity"/>
+        [Obsolete("use ModifySecurityDescriptorEx")]
         public static byte[] ModifySecurityDescriptor(
             Byte[] SecurityDescriptor,
             AccessControlSections Sections,
@@ -1140,6 +1141,47 @@ namespace Fsp
                 SecurityInformation,
                 ModificationDescriptor);
         }
+        /// <summary>
+        /// Modifies a security descriptor.
+        /// </summary>
+        /// <remarks>
+        /// This is a helper for implementing the SetSecurity operation.
+        /// </remarks>
+        /// <param name="SecurityDescriptor">
+        /// The original security descriptor.
+        /// </param>
+        /// <param name="Sections">
+        /// Describes what parts of the file or directory security descriptor should be modified.
+        /// </param>
+        /// <param name="ModificationDescriptor">
+        /// Describes the modifications to apply to the file or directory security descriptor.
+        /// </param>
+        /// <param name="ModifiedDescriptor">
+        /// The modified security descriptor. This parameter is modified only on success.
+        /// </param>
+        /// <returns>STATUS_SUCCESS or error code.</returns>
+        /// <seealso cref="SetSecurity"/>
+        public static Int32 ModifySecurityDescriptorEx(
+            Byte[] SecurityDescriptor,
+            AccessControlSections Sections,
+            Byte[] ModificationDescriptor,
+            ref Byte[] ModifiedDescriptor)
+        {
+            UInt32 SecurityInformation = 0;
+            if (0 != (Sections & AccessControlSections.Owner))
+                SecurityInformation |= 1/*OWNER_SECURITY_INFORMATION*/;
+            if (0 != (Sections & AccessControlSections.Group))
+                SecurityInformation |= 2/*GROUP_SECURITY_INFORMATION*/;
+            if (0 != (Sections & AccessControlSections.Access))
+                SecurityInformation |= 4/*DACL_SECURITY_INFORMATION*/;
+            if (0 != (Sections & AccessControlSections.Audit))
+                SecurityInformation |= 8/*SACL_SECURITY_INFORMATION*/;
+            return Api.ModifySecurityDescriptorEx(
+                SecurityDescriptor,
+                SecurityInformation,
+                ModificationDescriptor,
+                ref ModifiedDescriptor);
+        }
         public Int32 SeekableReadDirectory(
             Object FileNode,
             Object FileDesc,

src/dotnet/Interop.cs

@@ -928,6 +928,26 @@ namespace Fsp.Interop
                     return SecurityDescriptorBytes;
                 }
         }
+        internal unsafe static Int32 ModifySecurityDescriptorEx(
+            Byte[] SecurityDescriptorBytes,
+            UInt32 SecurityInformation,
+            Byte[] ModificationDescriptorBytes,
+            ref Byte[] ModifiedDescriptorBytes)
+        {
+            fixed (Byte *S = SecurityDescriptorBytes)
+                fixed (Byte *M = ModificationDescriptorBytes)
+                {
+                    IntPtr SecurityDescriptor;
+                    Int32 Result = FspSetSecurityDescriptor(
+                        (IntPtr)S, SecurityInformation, (IntPtr)M, out SecurityDescriptor);
+                    if (0 > Result)
+                        return Result;
+                    SecurityDescriptorBytes = MakeSecurityDescriptor(SecurityDescriptor);
+                    FspDeleteSecurityDescriptor(SecurityDescriptor, _FspSetSecurityDescriptorPtr);
+                    ModifiedDescriptorBytes = SecurityDescriptorBytes;
+                    return 0/*STATUS_SUCCESS*/;
+                }
+        }
 
         internal unsafe static Int32 CopyReparsePoint(
             Byte[] ReparseData,

src/launcher/launchctl.c

@@ -72,8 +72,8 @@ static int call_pipe_and_report(PWSTR PipeBuf, ULONG SendSize, ULONG RecvSize)
     NTSTATUS Result;
     DWORD LastError, BytesTransferred;
 
-    Result = FspCallNamedPipeSecurely(L"" FSP_LAUNCH_PIPE_NAME, PipeBuf, SendSize, PipeBuf, RecvSize,
-        &BytesTransferred, NMPWAIT_USE_DEFAULT_WAIT, FSP_LAUNCH_PIPE_OWNER);
+    Result = FspCallNamedPipeSecurelyEx(L"" FSP_LAUNCH_PIPE_NAME, PipeBuf, SendSize, PipeBuf, RecvSize,
+        &BytesTransferred, NMPWAIT_USE_DEFAULT_WAIT, TRUE, FSP_LAUNCH_PIPE_OWNER);
     LastError = FspWin32FromNtStatus(Result);
 
     if (0 != LastError)

src/launcher/launcher.c

@@ -255,6 +255,7 @@ exit:
 
 static BOOL LogonCreateProcess(
     PWSTR UserName,
+    HANDLE Token,
     LPCWSTR ApplicationName,
     LPWSTR CommandLine,
     LPSECURITY_ATTRIBUTES ProcessAttributes,
@@ -271,11 +272,20 @@ static BOOL LogonCreateProcess(
     if (0 != UserName)
     {
         if (0 == invariant_wcsicmp(UserName, L"LocalSystem"))
+        {
             UserName = 0;
+            Token = 0;
+        }
         else
         if (0 == invariant_wcsicmp(UserName, L"LocalService") ||
             0 == invariant_wcsicmp(UserName, L"NetworkService"))
+        {
             DomainName = L"NT AUTHORITY";
+            Token = 0;
+        }
+        else
+        if (0 == invariant_wcsicmp(UserName, L"."))
+            ;
         else
         {
             SetLastError(ERROR_ACCESS_DENIED);
@@ -299,18 +309,40 @@ static BOOL LogonCreateProcess(
 
     HANDLE LogonToken = 0;
     PVOID EnvironmentBlock = 0;
+    DWORD SessionId;
     DWORD LastError;
     BOOL Success;
 
-    Success = LogonUserW(
-        UserName,
-        DomainName,
-        0,
-        LOGON32_LOGON_SERVICE,
-        LOGON32_PROVIDER_DEFAULT,
-        &LogonToken);
-    if (!Success)
-        goto exit;
+    if (0 == Token)
+    {
+        Success = LogonUserW(
+            UserName,
+            DomainName,
+            0,
+            LOGON32_LOGON_SERVICE,
+            LOGON32_PROVIDER_DEFAULT,
+            &LogonToken);
+        if (!Success)
+            goto exit;
+    }
+    else
+    {
+        /* convert the impersonation token to a primary token */
+        Success = DuplicateTokenEx(Token,
+            TOKEN_ALL_ACCESS,
+            0,
+            SecurityAnonymous,
+            TokenPrimary,
+            &LogonToken);
+        if (!Success)
+            goto exit;
+        if (!ProcessIdToSessionId(GetCurrentProcessId(), &SessionId))
+            SessionId = 0;
+        /* place the duplicated token in the service session (session 0) */
+        Success = SetTokenInformation(LogonToken, TokenSessionId, &SessionId, sizeof SessionId);
+        if (!Success)
+            goto exit;
+    }
 
     if (0 == Environment)
     {
@@ -663,7 +695,7 @@ static NTSTATUS SvcInstanceAccessCheck(HANDLE ClientToken, ULONG DesiredAccess,
     return Result;
 }
 
-static NTSTATUS SvcInstanceCreateProcess(PWSTR UserName,
+static NTSTATUS SvcInstanceCreateProcess(PWSTR UserName, HANDLE ClientToken,
     PWSTR Executable, PWSTR CommandLine, PWSTR WorkDirectory,
     HANDLE StdioHandles[2],
     PPROCESS_INFORMATION ProcessInfo)
@@ -758,7 +790,7 @@ static NTSTATUS SvcInstanceCreateProcess(PWSTR UserName,
         StartupInfoEx.StartupInfo.hStdOutput = ChildHandles[1];
         StartupInfoEx.StartupInfo.hStdError = ChildHandles[2];
 
-        if (!LogonCreateProcess(UserName,
+        if (!LogonCreateProcess(UserName, ClientToken,
             Executable, CommandLine, 0, 0, TRUE,
             CREATE_SUSPENDED | CREATE_NEW_PROCESS_GROUP | EXTENDED_STARTUPINFO_PRESENT,
             0, WorkDirectory,
@@ -779,7 +811,7 @@ static NTSTATUS SvcInstanceCreateProcess(PWSTR UserName,
              * Not ideal, but...
              */
             StartupInfoEx.StartupInfo.cb = sizeof StartupInfoEx.StartupInfo;
-            if (!LogonCreateProcess(UserName,
+            if (!LogonCreateProcess(UserName, ClientToken,
                 Executable, CommandLine, 0, 0, TRUE,
                 CREATE_SUSPENDED | CREATE_NEW_PROCESS_GROUP,
                 0, WorkDirectory,
@@ -792,7 +824,7 @@ static NTSTATUS SvcInstanceCreateProcess(PWSTR UserName,
     }
     else
     {
-        if (!LogonCreateProcess(UserName,
+        if (!LogonCreateProcess(UserName, ClientToken,
             Executable, CommandLine, 0, 0, FALSE,
             CREATE_SUSPENDED | CREATE_NEW_PROCESS_GROUP,
             0, WorkDirectory,
@@ -1009,7 +1041,7 @@ NTSTATUS SvcInstanceCreate(HANDLE ClientToken,
     if (!NT_SUCCESS(Result))
         goto exit;
 
-    Result = SvcInstanceCreateProcess(L'\0' != RunAsBuf[0] ? RunAsBuf : 0,
+    Result = SvcInstanceCreateProcess(L'\0' != RunAsBuf[0] ? RunAsBuf : 0, ClientToken,
         Executable, SvcInstance->CommandLine, L'\0' != WorkDirectory[0] ? WorkDirectory : 0,
         RedirectStdio ? SvcInstance->StdioHandles : 0, &ProcessInfo);
     if (!NT_SUCCESS(Result))
@@ -1629,7 +1661,10 @@ static DWORD WINAPI SvcPipeServer(PVOID Context)
 
         ClientToken = 0;
         if (!ImpersonateNamedPipeClient(SvcPipe) ||
-            !OpenThreadToken(GetCurrentThread(), TOKEN_QUERY, FALSE, &ClientToken) ||
+            (
+                !OpenThreadToken(GetCurrentThread(), TOKEN_QUERY | TOKEN_DUPLICATE, FALSE, &ClientToken) &&
+                !OpenThreadToken(GetCurrentThread(), TOKEN_QUERY, FALSE, &ClientToken)
+            ) ||
             !RevertToSelf())
         {
             LastError = GetLastError();

src/sys/devctl.c

@@ -21,6 +21,8 @@
 
 #include <sys/driver.h>
 
+static NTSTATUS FspFsvrtDeviceControl(
+    PDEVICE_OBJECT DeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp);
 static NTSTATUS FspFsvolDeviceControl(
     PDEVICE_OBJECT DeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp);
 FSP_IOCMPL_DISPATCH FspFsvolDeviceControlComplete;
@@ -28,6 +30,7 @@ static FSP_IOP_REQUEST_FINI FspFsvolDeviceControlRequestFini;
 FSP_DRIVER_DISPATCH FspDeviceControl;
 
 #ifdef ALLOC_PRAGMA
+#pragma alloc_text(PAGE, FspFsvrtDeviceControl)
 #pragma alloc_text(PAGE, FspFsvolDeviceControl)
 #pragma alloc_text(PAGE, FspFsvolDeviceControlComplete)
 #pragma alloc_text(PAGE, FspFsvolDeviceControlRequestFini)
@@ -39,6 +42,28 @@ enum
     RequestFileNode                     = 0,
 };
 
+static NTSTATUS FspFsvrtDeviceControl(
+    PDEVICE_OBJECT FsvolDeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp)
+{
+    PAGED_CODE();
+
+    /*
+     * Fix GitHub issue #177. All credit for the investigation of this issue
+     * and the suggested steps to reproduce and work around the problem goes
+     * to GitHub user @thinkport.
+     *
+     * When Windows attempts to mount a new volume it iterates over all disk file
+     * systems registered with IoRegisterFileSystem. Foreign (i.e. non-WinFsp) file
+     * systems would in some cases attempt to mount our Fsvrt volume device by
+     * sending it unknown IOCTL codes, which would then be failed with
+     * STATUS_INVALID_DEVICE_REQUEST. Unfortunately the file systems would then
+     * report this error code to the I/O Manager, which would cause it to abort the
+     * mounting process completely and thus WinFsp would never get a chance to
+     * mount its own volume device!
+     */
+    return STATUS_UNRECOGNIZED_VOLUME;
+}
+
 static NTSTATUS FspFsvolDeviceControl(
     PDEVICE_OBJECT FsvolDeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp)
 {
@@ -155,6 +180,8 @@ NTSTATUS FspDeviceControl(
     {
     case FspFsvolDeviceExtensionKind:
         FSP_RETURN(Result = FspFsvolDeviceControl(DeviceObject, Irp, IrpSp));
+    case FspFsvrtDeviceExtensionKind:
+        FSP_RETURN(Result = FspFsvrtDeviceControl(DeviceObject, Irp, IrpSp));
     default:
         FSP_RETURN(Result = STATUS_INVALID_DEVICE_REQUEST);
     }

src/sys/driver.c

@@ -169,6 +169,21 @@ NTSTATUS DriverEntry(
         &FspFsmupDeviceObject);
     if (!NT_SUCCESS(Result))
         goto exit;
+
+#if DBG
+    /*
+     * Fix GitHub issue #177. All credit for the investigation of this issue
+     * and the suggested steps to reproduce and work around the problem goes
+     * to GitHub user @thinkport.
+     *
+     * On debug builds set DO_LOW_PRIORITY_FILESYSTEM to place the file system
+     * at the end of the file system list during IoRegisterFileSystem below.
+     * This allows us to test the behavior of our Fsvrt devices when foreign
+     * file systems attempt to use them for mounting.
+     */
+    SetFlag(FspFsctlDiskDeviceObject->Flags, DO_LOW_PRIORITY_FILESYSTEM);
+#endif
+
     Result = FspDeviceInitialize(FspFsctlDiskDeviceObject);
     ASSERT(STATUS_SUCCESS == Result);
     Result = FspDeviceInitialize(FspFsctlNetDeviceObject);

tools/run-tests.bat

@@ -725,13 +725,13 @@ exit /b 0
 
 :sample-passthrough-fuse3-x64
 call :__run_sample_fuse_test passthrough-fuse3 x64 passthrough-fuse3-x64 winfsp-tests-x64 ^
-    "-create_fileattr_test -setfileinfo_test"
+    "-create_fileattr_test -create_readonlydir_test -setfileinfo_test"
 if !ERRORLEVEL! neq 0 goto fail
 exit /b 0
 
 :sample-passthrough-fuse3-x86
 call :__run_sample_fuse_test passthrough-fuse3 x86 passthrough-fuse3-x86 winfsp-tests-x86 ^
-    "-create_fileattr_test -setfileinfo_test"
+    "-create_fileattr_test -create_readonlydir_test -setfileinfo_test"
 if !ERRORLEVEL! neq 0 goto fail
 exit /b 0
 
@@ -923,7 +923,7 @@ cd L: >nul 2>nul || (echo Unable to find drive L: >&2 & goto fail)
 L:
 "%ProjRoot%\build\VStudio\build\%Configuration%\%3.exe" ^
     --external --resilient --case-insensitive-cmp --share-prefix="\%1\%TMP::=$%\%1\test" ^
-    -create_fileattr_test -create_allocation_test -create_notraverse_test -create_backup_test -create_restore_test -create_namelen_test ^
+    -create_fileattr_test -create_readonlydir_test -create_allocation_test -create_notraverse_test -create_backup_test -create_restore_test -create_namelen_test ^
     -getfileinfo_name_test -setfileinfo_test -delete_access_test -delete_mmap_test -rename_flipflop_test -rename_mmap_test -setsecurity_test -querydir_namelen_test -exec_rename_dir_test ^
     -reparse* -stream*
 if !ERRORLEVEL! neq 0 set RunSampleTestExit=1

tst/memfs-dotnet/Program.cs

@@ -783,10 +783,8 @@ namespace memfs
             if (null != FileNode.MainFileNode)
                 FileNode = FileNode.MainFileNode;
 
-            FileNode.FileSecurity = ModifySecurityDescriptor(
-                FileNode.FileSecurity, Sections, SecurityDescriptor);
-
-            return STATUS_SUCCESS;
+            return ModifySecurityDescriptorEx(FileNode.FileSecurity, Sections, SecurityDescriptor,
+                ref FileNode.FileSecurity);
         }
 
         public override Boolean ReadDirectoryEntry(

tst/winfsp-tests/create-test.c

@@ -352,6 +352,68 @@ static void create_fileattr_test(void)
         create_fileattr_dotest(MemfsNet, L"\\\\memfs\\share");
 }
 
+static void create_readonlydir_dotest(ULONG Flags, PWSTR Prefix)
+{
+    void *memfs = memfs_start(Flags);
+
+    HANDLE Handle;
+    BOOLEAN Success;
+    DWORD FileAttributes;
+    WCHAR DirPath[MAX_PATH], FilePath[MAX_PATH];
+
+    StringCbPrintfW(DirPath, sizeof DirPath, L"%s%s\\dir0",
+        Prefix ? L"" : L"\\\\?\\GLOBALROOT", Prefix ? Prefix : memfs_volumename(memfs));
+
+    StringCbPrintfW(FilePath, sizeof FilePath, L"%s%s\\dir0\\file0",
+        Prefix ? L"" : L"\\\\?\\GLOBALROOT", Prefix ? Prefix : memfs_volumename(memfs));
+
+    Success = CreateDirectoryW(DirPath, 0);
+    ASSERT(Success);
+
+    Success = SetFileAttributesW(DirPath, FILE_ATTRIBUTE_DIRECTORY | FILE_ATTRIBUTE_READONLY);
+    ASSERT(Success);
+
+    FileAttributes = GetFileAttributesW(DirPath);
+    ASSERT((FILE_ATTRIBUTE_DIRECTORY | FILE_ATTRIBUTE_READONLY) == FileAttributes);
+
+    Handle = CreateFileW(FilePath,
+        GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, 0, CREATE_NEW, FILE_ATTRIBUTE_NORMAL, 0);
+    ASSERT(INVALID_HANDLE_VALUE != Handle);
+    CloseHandle(Handle);
+
+    Success = DeleteFileW(FilePath);
+    ASSERT(Success);
+
+    Success = RemoveDirectoryW(DirPath);
+    ASSERT(!Success);
+    ASSERT(ERROR_ACCESS_DENIED == GetLastError());
+
+    Success = SetFileAttributesW(DirPath, FILE_ATTRIBUTE_DIRECTORY);
+    ASSERT(Success);
+
+    FileAttributes = GetFileAttributesW(DirPath);
+    ASSERT(FILE_ATTRIBUTE_DIRECTORY == FileAttributes);
+
+    Success = RemoveDirectoryW(DirPath);
+    ASSERT(Success);
+
+    memfs_stop(memfs);
+}
+
+static void create_readonlydir_test(void)
+{
+    if (NtfsTests)
+    {
+        WCHAR DirBuf[MAX_PATH];
+        GetTestDirectory(DirBuf);
+        create_readonlydir_dotest(-1, DirBuf);
+    }
+    if (WinFspDiskTests)
+        create_readonlydir_dotest(MemfsDisk, 0);
+    if (WinFspNetTests)
+        create_readonlydir_dotest(MemfsNet, L"\\\\memfs\\share");
+}
+
 void create_related_dotest(ULONG Flags, PWSTR Prefix)
 {
     void *memfs = memfs_start(Flags);
@@ -1265,6 +1327,7 @@ void create_tests(void)
 {
     TEST(create_test);
     TEST(create_fileattr_test);
+    TEST(create_readonlydir_test);
     TEST(create_related_test);
     TEST(create_allocation_test);
     TEST(create_sd_test);