sys: FspUnicodePathIsValid: check and return stream type

src/sys/create.c

@@ -179,6 +179,7 @@ static NTSTATUS FspFsvolCreateNoLock(
     FSP_FILE_NODE *FileNode, *RelatedFileNode;
     FSP_FILE_DESC *FileDesc;
     UNICODE_STRING MainFileName = { 0 }, StreamPart = { 0 };
+    ULONG StreamType = FspUnicodePathStreamTypeNone;
     FSP_FSCTL_TRANSACT_REQ *Request;
 
     /* cannot open files by fileid */
@@ -276,7 +277,8 @@ static NTSTATUS FspFsvolCreateNoLock(
 
     /* check filename validity */
     if (!FspUnicodePathIsValid(&FileNode->FileName,
-        FsvolDeviceExtension->VolumeParams.NamedStreams ? &StreamPart : 0))
+        FsvolDeviceExtension->VolumeParams.NamedStreams ? &StreamPart : 0,
+        &StreamType))
     {
         FspFileNodeDereference(FileNode);
         return STATUS_OBJECT_NAME_INVALID;
@@ -291,7 +293,8 @@ static NTSTATUS FspFsvolCreateNoLock(
                 (PUINT8)FileNode->FileName.Buffer + FileNode->FileName.Length);
 
         FileNode->FileName.Length = (USHORT)
-            ((PUINT8)StreamPart.Buffer - (PUINT8)FileNode->FileName.Buffer + StreamPart.Length);
+            ((PUINT8)StreamPart.Buffer - (PUINT8)FileNode->FileName.Buffer + StreamPart.Length -
+            (0 == StreamPart.Length) * sizeof(WCHAR));
     }
 
     /* check and remove any volume prefix */
@@ -330,6 +333,16 @@ static NTSTATUS FspFsvolCreateNoLock(
         FileNode->FileName.Length -= sizeof(WCHAR);
     }
 
+    /* if a $DATA stream type, this cannot be a directory */
+    if (FspUnicodePathStreamTypeData == StreamType)
+    {
+        if (FlagOn(CreateOptions, FILE_DIRECTORY_FILE))
+        {
+            FspFileNodeDereference(FileNode);
+            return STATUS_NOT_A_DIRECTORY;
+        }
+    }
+
     /* not all operations allowed on the root directory */
     if (sizeof(WCHAR) == FileNode->FileName.Length &&
         (FILE_CREATE == CreateDisposition ||

src/sys/driver.h

@@ -423,9 +423,14 @@ BOOLEAN FspExpirationTimeValid2(UINT64 ExpirationTime, UINT64 CurrentTime)
 }
 
 /* utility */
+enum
+{
+    FspUnicodePathStreamTypeNone        = 0,
+    FspUnicodePathStreamTypeData        = 1,
+};
 PVOID FspAllocatePoolMustSucceed(POOL_TYPE PoolType, SIZE_T Size, ULONG Tag);
 PVOID FspAllocateIrpMustSucceed(CCHAR StackSize);
-BOOLEAN FspUnicodePathIsValid(PUNICODE_STRING Path, PUNICODE_STRING StreamPart);
+BOOLEAN FspUnicodePathIsValid(PUNICODE_STRING Path, PUNICODE_STRING StreamPart, PULONG StreamType);
 BOOLEAN FspUnicodePathIsValidPattern(PUNICODE_STRING Pattern);
 VOID FspUnicodePathSuffix(PUNICODE_STRING Path, PUNICODE_STRING Remain, PUNICODE_STRING Suffix);
 NTSTATUS FspCreateGuid(GUID *Guid);

src/sys/file.c

@@ -1274,7 +1274,7 @@ NTSTATUS FspMainFileOpen(
     PFILE_OBJECT MainFileObject;
 
     /* assert that the supplied name is actually a main file name */
-    ASSERT(FspUnicodePathIsValid(MainFileName, 0));
+    ASSERT(FspUnicodePathIsValid(MainFileName, 0, 0));
 
     *PMainFileHandle = 0;
     *PMainFileObject = 0;

src/sys/fileinfo.c

@@ -1114,7 +1114,7 @@ static NTSTATUS FspFsvolSetRenameInformation(
     if (FileNode->IsRootDirectory)
         /* cannot rename root directory */
         return STATUS_INVALID_PARAMETER;
-    if (!FspUnicodePathIsValid(&FileNode->FileName, 0))
+    if (!FspUnicodePathIsValid(&FileNode->FileName, 0, 0))
         /* cannot rename streams (WinFsp limitation) */
         return STATUS_INVALID_PARAMETER;
 
@@ -1139,7 +1139,7 @@ static NTSTATUS FspFsvolSetRenameInformation(
     if (L'\\' == Suffix.Buffer[0])
         FspUnicodePathSuffix(&Suffix, &NewFileName, &Suffix);
 
-    if (!FspUnicodePathIsValid(&Remain, 0) || !FspUnicodePathIsValid(&Suffix, 0))
+    if (!FspUnicodePathIsValid(&Remain, 0, 0) || !FspUnicodePathIsValid(&Suffix, 0, 0))
     {
         /* cannot rename streams (WinFsp limitation) */
         Result = STATUS_INVALID_PARAMETER;

src/sys/util.c

@@ -17,7 +17,7 @@
 
 #include <sys/driver.h>
 
-BOOLEAN FspUnicodePathIsValid(PUNICODE_STRING Path, PUNICODE_STRING StreamPart);
+BOOLEAN FspUnicodePathIsValid(PUNICODE_STRING Path, PUNICODE_STRING StreamPart, PULONG StreamType);
 BOOLEAN FspUnicodePathIsValidPattern(PUNICODE_STRING Pattern);
 VOID FspUnicodePathSuffix(PUNICODE_STRING Path, PUNICODE_STRING Remain, PUNICODE_STRING Suffix);
 NTSTATUS FspCreateGuid(GUID *Guid);
@@ -171,14 +171,17 @@ PVOID FspAllocateIrpMustSucceed(CCHAR StackSize)
     }
 }
 
-BOOLEAN FspUnicodePathIsValid(PUNICODE_STRING Path, PUNICODE_STRING StreamPart)
+BOOLEAN FspUnicodePathIsValid(PUNICODE_STRING Path, PUNICODE_STRING StreamPart, PULONG StreamType)
 {
     PAGED_CODE();
 
+    /* if StreamPart is not NULL, StreamType must also be not NULL */
+    ASSERT(0 == StreamPart || 0 != StreamType);
+
     if (0 != Path->Length % sizeof(WCHAR))
         return FALSE;
 
-    PWSTR PathBgn, PathEnd, PathPtr;
+    PWSTR PathBgn, PathEnd, PathPtr, StreamTypeStr = 0;
     UCHAR Flags = FSRTL_NTFS_LEGAL;
     ULONG Colons = 0;
     WCHAR Char;
@@ -221,15 +224,17 @@ BOOLEAN FspUnicodePathIsValid(PUNICODE_STRING Path, PUNICODE_STRING StreamPart)
             if (1 == Colons)
             {
                 /* first time through: set up StreamPart */
-                StreamPart->Length = StreamPart->MaximumLength =
+                StreamPart->Length = StreamPart->MaximumLength = (USHORT)
-                    (USHORT)((PUINT8)PathEnd - (PUINT8)PathPtr);
+                    ((PUINT8)PathEnd - (PUINT8)PathPtr);
                 StreamPart->Buffer = PathPtr;
             }
             else if (2 == Colons)
             {
                 /* second time through: fix StreamPart length to not include 2nd colon */
-                StreamPart->Length =
+                StreamPart->Length = (USHORT)
-                    (USHORT)((PUINT8)PathPtr - (PUINT8)StreamPart->Buffer - 1);
+                    ((PUINT8)PathPtr - (PUINT8)StreamPart->Buffer - sizeof(WCHAR));
+
+                StreamTypeStr = PathPtr;
             }
         }
         else if (0x80 > Char && !FsRtlTestAnsiCharacter(Char, TRUE, FALSE, Flags))
@@ -238,7 +243,31 @@ BOOLEAN FspUnicodePathIsValid(PUNICODE_STRING Path, PUNICODE_STRING StreamPart)
             PathPtr++;
     }
 
-    return TRUE;
+    /* if we had no colons the path is valid */
+    if (0 == Colons)
+        return TRUE;
+
+    ASSERT(0 != StreamPart && 0 != StreamType);
+
+    *StreamType = FspUnicodePathStreamTypeNone;
+
+    /* if we had no stream type the path is valid if there was an actual stream name */
+    if (0 == StreamTypeStr)
+        return 0 != StreamPart->Length;
+
+    /* if we had a stream type the path is valid if the stream type was "$DATA" only */
+    if (StreamTypeStr + 5 == PathEnd &&
+        L'$' == StreamTypeStr[0] &&
+        L'D' == StreamTypeStr[1] &&
+        L'A' == StreamTypeStr[2] &&
+        L'T' == StreamTypeStr[3] &&
+        L'A' == StreamTypeStr[4])
+    {
+        *StreamType = FspUnicodePathStreamTypeData;
+        return TRUE;
+    }
+
+    return FALSE;
 }
 
 BOOLEAN FspUnicodePathIsValidPattern(PUNICODE_STRING Path)