dll: np: NPAddConnection3, NPCancelConnection implementation

src/dll/library.def

@@ -3,3 +3,6 @@ EXPORTS
     DllUnregisterServer PRIVATE
     NPGetCaps           PRIVATE
     NPGetConnection     PRIVATE
+    NPAddConnection     PRIVATE
+    NPAddConnection3    PRIVATE
+    NPCancelConnection  PRIVATE

src/dll/np.c

@@ -16,6 +16,7 @@
  */
 
 #include <dll/library.h>
+#include <launcher/launcher.h>
 #include <npapi.h>
 
 #define FSP_NP_NAME                     LIBRARY_NAME ".Np"
@@ -33,14 +34,17 @@ DWORD APIENTRY NPGetCaps(DWORD Index)
         return 0;
     case WNNC_CONNECTION:
         /*
-         * WNNC_CON_ADDCONECTION
+         * WNNC_CON_ADDCONNECTION
          * WNNC_CON_CANCELCONNECTION
          * WNNC_CON_GETCONNECTIONS
-         * WNNC_CON_ADDCONECTION3
+         * WNNC_CON_ADDCONNECTION3
          * WNNC_CON_GETPERFORMANCE
          * WNNC_CON_DEFER
          */
-        return WNNC_CON_GETCONNECTIONS;
+        return
+            WNNC_CON_GETCONNECTIONS |
+            WNNC_CON_ADDCONNECTION | WNNC_CON_ADDCONNECTION3 |
+            WNNC_CON_CANCELCONNECTION;
     case WNNC_DIALOG:
         /*
          * WNNC_DLG_DEVICEMODE
@@ -75,6 +79,88 @@ DWORD APIENTRY NPGetCaps(DWORD Index)
     }
 }
 
+static inline BOOLEAN FspNpCheckLocalName(PWSTR LocalName)
+{
+    return 0 != LocalName &&
+        (
+            (L'A' <= LocalName[0] && LocalName[0] <= L'Z') ||
+            (L'a' <= LocalName[0] && LocalName[0] <= L'z')
+        ) &&
+        L':' == LocalName[1] || L'\0' == LocalName[2];
+}
+
+static inline BOOLEAN FspNpCheckRemoteName(PWSTR RemoteName)
+{
+    return 0 != RemoteName && L'\\' == RemoteName[0] && L'\\' == RemoteName[1] &&
+        sizeof(((FSP_FSCTL_VOLUME_PARAMS *)0)->Prefix) / sizeof(WCHAR) >= lstrlenW(RemoteName);
+}
+
+static inline BOOLEAN FspNpParseRemoteName(PWSTR RemoteName,
+    PWSTR *PClassName, PULONG PClassNameLen,
+    PWSTR *PInstanceName, PULONG PInstanceNameLen)
+{
+    PWSTR ClassName, InstanceName, P;
+    ULONG ClassNameLen, InstanceNameLen;
+
+    ClassName = RemoteName + 2; /* skip \\ */
+    for (P = ClassName; *P; P++)
+        if (L'\\' == *P)
+            break;
+    if (ClassName == P || L'\\' != *P)
+        return FALSE;
+    ClassNameLen = (ULONG)(P - ClassName);
+
+    InstanceName = P + 1;
+    for (P = InstanceName; *P; P++)
+        ;
+    for (;;)
+    {
+        if (InstanceName == P)
+            return FALSE;
+        if (L'\\' != P[-1])
+            break;
+        P--;
+    }
+    InstanceNameLen = (ULONG)(P - InstanceName);
+
+    *PClassName = ClassName; *PClassNameLen = ClassNameLen;
+    *PInstanceName = InstanceName; *PInstanceNameLen = InstanceNameLen;
+    
+    return TRUE;
+}
+
+static inline DWORD FspNpCallLauncherPipe(PWSTR PipeBuf, ULONG SendSize, ULONG RecvSize)
+{
+    DWORD NpResult;
+    DWORD LastError, BytesTransferred;
+
+    LastError = CallNamedPipeW(L"" LAUNCHER_PIPE_NAME, PipeBuf, SendSize, PipeBuf, RecvSize,
+        &BytesTransferred, NMPWAIT_USE_DEFAULT_WAIT) ? 0 : GetLastError();
+
+    if (0 != LastError)
+        NpResult = WN_NO_NETWORK;
+    else if (sizeof(WCHAR) > BytesTransferred)
+        NpResult = WN_NO_NETWORK;
+    else if (LauncherSuccess == PipeBuf[0])
+        NpResult = WN_SUCCESS;
+    else if (LauncherFailure == PipeBuf[0])
+    {
+        if (BytesTransferred < RecvSize)
+            PipeBuf[BytesTransferred / sizeof(WCHAR)] = L'\0';
+        else
+            PipeBuf[RecvSize / sizeof(WCHAR) - 1] = L'\0';
+
+        if (0 == lstrcmpW(L"183"/*ERROR_ALREADY_EXISTS*/, PipeBuf + 1))
+            NpResult = WN_ALREADY_CONNECTED;
+        else
+            NpResult = WN_NO_NETWORK;
+    }
+    else 
+        NpResult = WN_NO_NETWORK;
+
+    return NpResult;
+}
+
 static NTSTATUS FspNpGetVolumeList(
     PWCHAR *PVolumeListBuf, PSIZE_T PVolumeListSize)
 {
@@ -107,7 +193,8 @@ static NTSTATUS FspNpGetVolumeList(
     }
 }
 
-DWORD APIENTRY NPGetConnection(LPWSTR lpLocalName, LPWSTR lpRemoteName, LPDWORD lpnBufferLen)
+DWORD APIENTRY NPGetConnection(
+    LPWSTR lpLocalName, LPWSTR lpRemoteName, LPDWORD lpnBufferLen)
 {
     DWORD NpResult;
     NTSTATUS Result;
@@ -117,15 +204,10 @@ DWORD APIENTRY NPGetConnection(LPWSTR lpLocalName, LPWSTR lpRemoteName, LPDWORD
     SIZE_T VolumeListSize, VolumeNameSize;
     ULONG Backslashes;
 
-    if (0 == lpLocalName ||
+    if (!FspNpCheckLocalName(lpLocalName))
-        !(
-            (L'A' <= lpLocalName[0] && lpLocalName[0] <= L'Z') ||
-            (L'a' <= lpLocalName[0] && lpLocalName[0] <= L'z')
-        ) ||
-        L':' != lpLocalName[1])
         return WN_BAD_LOCALNAME;
 
-    LocalNameBuf[0] = lpLocalName[0];
+    LocalNameBuf[0] = lpLocalName[0] & ~0x20; /* convert to uppercase */
     LocalNameBuf[1] = L':';
     LocalNameBuf[2] = L'\0';
 
@@ -188,6 +270,111 @@ DWORD APIENTRY NPGetConnection(LPWSTR lpLocalName, LPWSTR lpRemoteName, LPDWORD
     return NpResult;
 }
 
+DWORD APIENTRY NPAddConnection(LPNETRESOURCEW lpNetResource, LPWSTR lpPassword, LPWSTR lpUserName)
+{
+    return NPAddConnection3(0, lpNetResource, lpPassword, lpUserName, 0);
+}
+
+DWORD APIENTRY NPAddConnection3(HWND hwndOwner,
+    LPNETRESOURCEW lpNetResource, LPWSTR lpPassword, LPWSTR lpUserName, DWORD dwFlags)
+{
+    DWORD NpResult;
+    DWORD dwType = lpNetResource->dwType;
+    LPWSTR lpRemoteName = lpNetResource->lpRemoteName;
+    LPWSTR lpLocalName = lpNetResource->lpLocalName;
+    WCHAR LocalNameBuf[3];
+    PWSTR ClassName, InstanceName, RemoteName, P;
+    ULONG ClassNameLen, InstanceNameLen;
+    PWSTR PipeBuf = 0;
+
+    if (dwType & RESOURCETYPE_PRINT)
+        return WN_BAD_VALUE;
+
+    if (!FspNpCheckRemoteName(lpRemoteName))
+        return WN_BAD_NETNAME;
+
+    if (!FspNpParseRemoteName(lpRemoteName,
+        &ClassName, &ClassNameLen, &InstanceName, &InstanceNameLen))
+        return WN_BAD_NETNAME;
+    RemoteName = lpRemoteName + 1;
+
+    LocalNameBuf[0] = L'\0';
+    if (0 != lpLocalName && L'\0' != lpLocalName[0])
+    {
+        if (!FspNpCheckLocalName(lpLocalName))
+            return WN_BAD_LOCALNAME;
+
+        LocalNameBuf[0] = lpLocalName[0] & ~0x20; /* convert to uppercase */
+        LocalNameBuf[1] = L':';
+        LocalNameBuf[2] = L'\0';
+
+        if (GetLogicalDrives() & (1 << (LocalNameBuf[0] - 'A')))
+            return WN_ALREADY_CONNECTED;
+    }
+
+    PipeBuf = MemAlloc(LAUNCHER_PIPE_BUFFER_SIZE);
+    if (0 == PipeBuf)
+        return WN_OUT_OF_MEMORY;
+
+    P = PipeBuf;
+    *P++ = LauncherSvcInstanceStart;
+    memcpy(P, ClassName, ClassNameLen * sizeof(WCHAR)); P += ClassNameLen; *P++ = L'\0';
+    memcpy(P, InstanceName, InstanceNameLen * sizeof(WCHAR)); P += InstanceNameLen; *P++ = L'\0';
+    lstrcpyW(P, RemoteName); P += lstrlenW(RemoteName) + 1;
+    lstrcpyW(P, LocalNameBuf); P += lstrlenW(LocalNameBuf) + 1;
+
+    NpResult = FspNpCallLauncherPipe(
+        PipeBuf, (ULONG)(P - PipeBuf) * sizeof(WCHAR), LAUNCHER_PIPE_BUFFER_SIZE);
+
+    MemFree(PipeBuf);
+
+    return NpResult;
+}
+
+DWORD APIENTRY NPCancelConnection(LPWSTR lpName, BOOL fForce)
+{
+    DWORD NpResult;
+    WCHAR RemoteNameBuf[sizeof(((FSP_FSCTL_VOLUME_PARAMS *)0)->Prefix) / sizeof(WCHAR)];
+    DWORD RemoteNameSize;
+    PWSTR ClassName, InstanceName, RemoteName, P;
+    ULONG ClassNameLen, InstanceNameLen;
+    PWSTR PipeBuf = 0;
+
+    if (FspNpCheckLocalName(lpName))
+    {
+        RemoteNameSize = sizeof RemoteNameBuf / sizeof(WCHAR);
+        NpResult = NPGetConnection(lpName, RemoteNameBuf, &RemoteNameSize);
+        if (WN_SUCCESS != NpResult)
+            return NpResult;
+
+        RemoteName = RemoteNameBuf;
+    }
+    else if (FspNpCheckRemoteName(lpName))
+        RemoteName = lpName;
+    else
+        return WN_BAD_NETNAME;
+
+    if (!FspNpParseRemoteName(RemoteName,
+        &ClassName, &ClassNameLen, &InstanceName, &InstanceNameLen))
+        return WN_BAD_NETNAME;
+
+    PipeBuf = MemAlloc(LAUNCHER_PIPE_BUFFER_SIZE);
+    if (0 == PipeBuf)
+        return WN_OUT_OF_MEMORY;
+
+    P = PipeBuf;
+    *P++ = LauncherSvcInstanceStop;
+    memcpy(P, ClassName, ClassNameLen * sizeof(WCHAR)); P += ClassNameLen; *P++ = L'\0';
+    memcpy(P, InstanceName, InstanceNameLen * sizeof(WCHAR)); P += InstanceNameLen; *P++ = L'\0';
+
+    NpResult = FspNpCallLauncherPipe(
+        PipeBuf, (ULONG)(P - PipeBuf) * sizeof(WCHAR), LAUNCHER_PIPE_BUFFER_SIZE);
+
+    MemFree(PipeBuf);
+
+    return NpResult;
+}
+
 NTSTATUS FspNpRegister(VOID)
 {
     extern HINSTANCE DllInstance;

src/launcher/launchctl.c

@@ -65,14 +65,14 @@ static int call_pipe_and_report(PWSTR PipeBuf, ULONG SendSize, ULONG RecvSize)
 {
     DWORD LastError, BytesTransferred;
 
-    LastError = CallNamedPipeW(L"" PIPE_NAME, PipeBuf, SendSize, PipeBuf, RecvSize,
+    LastError = CallNamedPipeW(L"" LAUNCHER_PIPE_NAME, PipeBuf, SendSize, PipeBuf, RecvSize,
         &BytesTransferred, NMPWAIT_USE_DEFAULT_WAIT) ? 0 : GetLastError();
 
     if (0 != LastError)
         warn("KO CallNamedPipeW = %ld", LastError);
-    else if (0 == BytesTransferred)
+    else if (sizeof(WCHAR) > BytesTransferred)
         warn("KO launcher: empty buffer");
-    else if (L'$' == PipeBuf[0])
+    else if (LauncherSuccess == PipeBuf[0])
     {
         if (sizeof(WCHAR) == BytesTransferred)
             info("OK");
@@ -97,7 +97,7 @@ static int call_pipe_and_report(PWSTR PipeBuf, ULONG SendSize, ULONG RecvSize)
             info("OK\n%S", PipeBuf + 1);
         }
     }
-    else if (L'!' == PipeBuf[0])
+    else if (LauncherFailure == PipeBuf[0])
     {
         if (BytesTransferred < RecvSize)
             PipeBuf[BytesTransferred / sizeof(WCHAR)] = L'\0';
@@ -213,7 +213,7 @@ int wmain(int argc, wchar_t **argv)
     PWSTR PipeBuf = 0;
 
     /* allocate our PipeBuf early on; freed on process exit by the system */
-    PipeBuf = MemAlloc(PIPE_BUFFER_SIZE);
+    PipeBuf = MemAlloc(LAUNCHER_PIPE_BUFFER_SIZE);
     if (0 == PipeBuf)
         return ERROR_NO_SYSTEM_RESOURCES;
 
@@ -228,7 +228,7 @@ int wmain(int argc, wchar_t **argv)
         if (3 > argc || argc > 12)
             usage();
 
-        return start(PipeBuf, PIPE_BUFFER_SIZE, argv[1], argv[2], argc - 3, argv + 3);
+        return start(PipeBuf, LAUNCHER_PIPE_BUFFER_SIZE, argv[1], argv[2], argc - 3, argv + 3);
     }
     else
     if (0 == lstrcmpW(L"stop", argv[0]))
@@ -236,7 +236,7 @@ int wmain(int argc, wchar_t **argv)
         if (3 != argc)
             usage();
 
-        return stop(PipeBuf, PIPE_BUFFER_SIZE, argv[1], argv[2]);
+        return stop(PipeBuf, LAUNCHER_PIPE_BUFFER_SIZE, argv[1], argv[2]);
     }
     else
     if (0 == lstrcmpW(L"info", argv[0]))
@@ -244,7 +244,7 @@ int wmain(int argc, wchar_t **argv)
         if (3 != argc)
             usage();
 
-        return getinfo(PipeBuf, PIPE_BUFFER_SIZE, argv[1], argv[2]);
+        return getinfo(PipeBuf, LAUNCHER_PIPE_BUFFER_SIZE, argv[1], argv[2]);
     }
     else
     if (0 == lstrcmpW(L"list", argv[0]))
@@ -252,7 +252,7 @@ int wmain(int argc, wchar_t **argv)
         if (1 != argc)
             usage();
 
-        return list(PipeBuf, PIPE_BUFFER_SIZE);
+        return list(PipeBuf, LAUNCHER_PIPE_BUFFER_SIZE);
     }
     else
     if (0 == lstrcmpW(L"quit", argv[0]))
@@ -261,7 +261,7 @@ int wmain(int argc, wchar_t **argv)
             usage();
 
         /* works only against DEBUG version of launcher */
-        return quit(PipeBuf, PIPE_BUFFER_SIZE);
+        return quit(PipeBuf, LAUNCHER_PIPE_BUFFER_SIZE);
     }
     else
         usage();

src/launcher/launcher.c

@@ -487,7 +487,7 @@ NTSTATUS SvcInstanceStop(HANDLE ClientToken,
     if (!NT_SUCCESS(Result))
         goto exit;
 
-    KillProcess(SvcInstance->ProcessId, SvcInstance->Process, KILL_TIMEOUT);
+    KillProcess(SvcInstance->ProcessId, SvcInstance->Process, LAUNCHER_KILL_TIMEOUT);
 
     Result = STATUS_SUCCESS;
 
@@ -588,12 +588,12 @@ NTSTATUS SvcInstanceStopAndWaitAll(VOID)
     {
         SvcInstance = CONTAINING_RECORD(ListEntry, SVC_INSTANCE, ListEntry);
 
-        KillProcess(SvcInstance->ProcessId, SvcInstance->Process, KILL_TIMEOUT);
+        KillProcess(SvcInstance->ProcessId, SvcInstance->Process, LAUNCHER_KILL_TIMEOUT);
     }
 
     LeaveCriticalSection(&SvcInstanceLock);
 
-    WaitForSingleObject(SvcInstanceEvent, STOP_TIMEOUT);
+    WaitForSingleObject(SvcInstanceEvent, LAUNCHER_STOP_TIMEOUT);
 
     return STATUS_SUCCESS;
 }
@@ -621,7 +621,7 @@ static NTSTATUS SvcStart(FSP_SERVICE *Service, ULONG argc, PWSTR *argv)
 
     SecurityAttributes.nLength = sizeof SecurityAttributes;
     SecurityAttributes.bInheritHandle = FALSE;
-    if (!ConvertStringSecurityDescriptorToSecurityDescriptorW(L"" PIPE_SDDL, SDDL_REVISION_1,
+    if (!ConvertStringSecurityDescriptorToSecurityDescriptorW(L"" LAUNCHER_PIPE_SDDL, SDDL_REVISION_1,
         &SecurityAttributes.lpSecurityDescriptor, 0))
         goto fail;
 
@@ -654,11 +654,12 @@ static NTSTATUS SvcStart(FSP_SERVICE *Service, ULONG argc, PWSTR *argv)
     if (0 == SvcOverlapped.hEvent)
         goto fail;
 
-    SvcPipe = CreateNamedPipeW(L"" PIPE_NAME,
+    SvcPipe = CreateNamedPipeW(L"" LAUNCHER_PIPE_NAME,
         PIPE_ACCESS_DUPLEX |
             FILE_FLAG_FIRST_PIPE_INSTANCE | FILE_FLAG_WRITE_THROUGH | FILE_FLAG_OVERLAPPED,
         PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT | PIPE_REJECT_REMOTE_CLIENTS,
-        1, PIPE_BUFFER_SIZE, PIPE_BUFFER_SIZE, PIPE_DEFAULT_TIMEOUT, &SecurityAttributes);
+        1, LAUNCHER_PIPE_BUFFER_SIZE, LAUNCHER_PIPE_BUFFER_SIZE, LAUNCHER_PIPE_DEFAULT_TIMEOUT,
+        &SecurityAttributes);
     if (INVALID_HANDLE_VALUE == SvcPipe)
         goto fail;
 
@@ -708,8 +709,8 @@ static NTSTATUS SvcStop(FSP_SERVICE *Service)
     if (GetCurrentThreadId() != SvcThreadId)
     {
         SetEvent(SvcEvent);
-        FspServiceRequestTime(Service, STOP_TIMEOUT);
+        FspServiceRequestTime(Service, LAUNCHER_STOP_TIMEOUT);
-        WaitForSingleObject(SvcThread, STOP_TIMEOUT);
+        WaitForSingleObject(SvcThread, LAUNCHER_STOP_TIMEOUT);
     }
 
     /*
@@ -779,7 +780,7 @@ static DWORD WINAPI SvcPipeServer(PVOID Context)
     HANDLE ClientToken;
     DWORD LastError, BytesTransferred;
 
-    PipeBuf = MemAlloc(PIPE_BUFFER_SIZE);
+    PipeBuf = MemAlloc(LAUNCHER_PIPE_BUFFER_SIZE);
     if (0 == PipeBuf)
     {
         FspServiceSetExitCode(Service, ERROR_NO_SYSTEM_RESOURCES);
@@ -802,7 +803,7 @@ static DWORD WINAPI SvcPipeServer(PVOID Context)
         }
 
         LastError = SvcPipeWaitResult(
-            ReadFile(SvcPipe, PipeBuf, PIPE_BUFFER_SIZE, &BytesTransferred, &SvcOverlapped),
+            ReadFile(SvcPipe, PipeBuf, LAUNCHER_PIPE_BUFFER_SIZE, &BytesTransferred, &SvcOverlapped),
             SvcEvent, SvcPipe, &SvcOverlapped, &BytesTransferred);
         if (-1 == LastError)
             break;
@@ -892,11 +893,12 @@ static inline VOID SvcPipeTransactResult(NTSTATUS Result, PWSTR PipeBuf, PULONG
 {
     if (NT_SUCCESS(Result))
     {
-        *PipeBuf = L'$';
+        *PipeBuf = LauncherSuccess;
         *PSize += sizeof(WCHAR);
     }
     else
-        *PSize = (wsprintfW(PipeBuf, L"!%ld", FspWin32FromNtStatus(Result)) + 1) * sizeof(WCHAR);
+        *PSize = (wsprintfW(PipeBuf, L"%c%ld", LauncherFailure, FspWin32FromNtStatus(Result)) + 1) *
+            sizeof(WCHAR);
 }
 
 static VOID SvcPipeTransact(HANDLE ClientToken, PWSTR PipeBuf, PULONG PSize)
@@ -945,7 +947,7 @@ static VOID SvcPipeTransact(HANDLE ClientToken, PWSTR PipeBuf, PULONG PSize)
         Result = STATUS_INVALID_PARAMETER;
         if (0 != ClassName && 0 != InstanceName)
         {
-            *PSize = PIPE_BUFFER_SIZE - 1;
+            *PSize = LAUNCHER_PIPE_BUFFER_SIZE - 1;
             Result = SvcInstanceGetInfo(ClientToken, ClassName, InstanceName, PipeBuf + 1, PSize);
         }
 
@@ -953,7 +955,7 @@ static VOID SvcPipeTransact(HANDLE ClientToken, PWSTR PipeBuf, PULONG PSize)
         break;
 
     case LauncherSvcInstanceList:
-        *PSize = PIPE_BUFFER_SIZE - 1;
+        *PSize = LAUNCHER_PIPE_BUFFER_SIZE - 1;
         Result = SvcInstanceGetNameList(ClientToken, PipeBuf + 1, PSize);
 
         SvcPipeTransactResult(Result, PipeBuf, PSize);

src/launcher/launcher.h

@@ -21,12 +21,12 @@
 #include <winfsp/winfsp.h>
 #include <shared/minimal.h>
 
-#define STOP_TIMEOUT                    5500
+#define LAUNCHER_STOP_TIMEOUT           5500
-#define KILL_TIMEOUT                    5000
+#define LAUNCHER_KILL_TIMEOUT           5000
 
-#define PIPE_NAME                       "\\\\.\\pipe\\WinFsp.{14E7137D-22B4-437A-B0C1-D21D1BDF3767}"
+#define LAUNCHER_PIPE_NAME              "\\\\.\\pipe\\WinFsp.{14E7137D-22B4-437A-B0C1-D21D1BDF3767}"
-#define PIPE_BUFFER_SIZE                2048
+#define LAUNCHER_PIPE_BUFFER_SIZE       2048
-#define PIPE_DEFAULT_TIMEOUT            3000
+#define LAUNCHER_PIPE_DEFAULT_TIMEOUT   3000
 
 /*
  * The launcher named pipe SDDL gives full access to LocalSystem and Administrators.
@@ -38,7 +38,7 @@
  * the FILE_CREATE_PIPE_INSTANCE right is that the server creates the named pipe with
  * MaxInstances == 1 (and therefore no client can create additional instances).
  */
-#define PIPE_SDDL                       "D:P(A;;GA;;;SY)(A;;GA;;;BA)(A;;GRGW;;;WD)"
+#define LAUNCHER_PIPE_SDDL              "D:P(A;;GA;;;SY)(A;;GA;;;BA)(A;;GRGW;;;WD)"
 
  /*
  * The default service instance SDDL gives full access to LocalSystem and Administrators.
@@ -60,6 +60,9 @@ enum
     LauncherSvcInstanceInfo             = 'I',  /* requires: SERVICE_QUERY_STATUS */
     LauncherSvcInstanceList             = 'L',  /* requires: none*/
     LauncherQuit                        = 'Q',  /* DEBUG version only */
+
+    LauncherSuccess                     = '$',
+    LauncherFailure                     = '!',
 };
 
 #endif

tst/memfs/memfs-main.c

@@ -82,6 +82,9 @@ NTSTATUS SvcStart(FSP_SERVICE *Service, ULONG argc, PWSTR *argv)
     if (arge > argp)
         goto usage;
 
+    if (MemfsDisk == Flags && 0 == MountPoint)
+        goto usage;
+
     Result = MemfsCreate(Flags, FileInfoTimeout, MaxFileNodes, MaxFileSize, VolumePrefix, RootSddl,
         &Memfs);
     if (!NT_SUCCESS(Result))
@@ -90,13 +93,16 @@ NTSTATUS SvcStart(FSP_SERVICE *Service, ULONG argc, PWSTR *argv)
         goto exit;
     }
 
+    if (0 != MountPoint && L'\0' != MountPoint[0])
+    {
         Result = FspFileSystemSetMountPoint(MemfsFileSystem(Memfs),
-        MountPoint && MountPoint[0] ? MountPoint : 0);
+            L'*' == MountPoint[0] && L'\0' == MountPoint[1] ? 0 : MountPoint);
         if (!NT_SUCCESS(Result))
         {
             fail(L"cannot mount MEMFS");
             goto exit;
         }
+    }
 
     Result = MemfsStart(Memfs);
     if (!NT_SUCCESS(Result))
@@ -107,11 +113,11 @@ NTSTATUS SvcStart(FSP_SERVICE *Service, ULONG argc, PWSTR *argv)
 
     MountPoint = FspFileSystemMountPoint(MemfsFileSystem(Memfs));
 
-    info(L"%s -t %ld -n %ld -s %ld%s%s%s%s -m %s",
+    info(L"%s -t %ld -n %ld -s %ld%s%s%s%s%s%s",
         L"" PROGNAME, FileInfoTimeout, MaxFileNodes, MaxFileSize,
         RootSddl ? L" -S " : L"", RootSddl ? RootSddl : L"",
         VolumePrefix ? L" -u " : L"", VolumePrefix ? VolumePrefix : L"",
-        MountPoint);
+        MountPoint ? L" -m " : L"", MountPoint ? MountPoint : L"");
 
     Service->UserContext = Memfs;
     Result = STATUS_SUCCESS;
@@ -132,7 +138,7 @@ usage:
         "    -s MaxFileSize      [bytes]\n"
         "    -S RootSddl         [file rights: FA, etc; NO generic rights: GA, etc.]\n"
         "    -u \\Server\\Share    [UNC prefix (single backslash)]\n"
-        "    -m MountPoint       [X:]\n";
+        "    -m MountPoint       [X:|* (required if no UNC prefix)]\n";
 
     fail(usage, L"" PROGNAME);