memfs: Rename: bugfix

tst/memfs/memfs.cpp

@@ -237,6 +237,22 @@ BOOLEAN MemfsFileNodeMapEnumerateChildren(MEMFS_FILE_NODE_MAP *FileNodeMap, MEMF
     return TRUE;
 }
 
+static inline
+BOOLEAN MemfsFileNodeMapEnumerateDescendants(MEMFS_FILE_NODE_MAP *FileNodeMap, MEMFS_FILE_NODE *FileNode,
+    BOOLEAN (*EnumFn)(MEMFS_FILE_NODE *, PVOID), PVOID Context)
+{
+    WCHAR Root[2] = L"\\";
+    MEMFS_FILE_NODE_MAP::iterator iter = FileNodeMap->lower_bound(FileNode->FileName);
+    for (; FileNodeMap->end() != iter; ++iter)
+    {
+        if (!MemfsFileNameHasPrefix(iter->second->FileName, FileNode->FileName))
+            break;
+        if (!EnumFn(iter->second, Context))
+            return FALSE;
+    }
+    return TRUE;
+}
+
 static NTSTATUS SetFileSize(FSP_FILE_SYSTEM *FileSystem,
     FSP_FSCTL_TRANSACT_REQ *Request,
     PVOID FileNode0, UINT64 FileSize,
@@ -630,6 +646,22 @@ static NTSTATUS CanDelete(FSP_FILE_SYSTEM *FileSystem,
     return STATUS_SUCCESS;
 }
 
+typedef struct _MEMFS_RENAME_CONTEXT
+{
+    MEMFS_FILE_NODE **FileNodes;
+    ULONG Count;
+} MEMFS_RENAME_CONTEXT;
+
+static BOOLEAN RenameEnumFn(MEMFS_FILE_NODE *FileNode, PVOID Context0)
+{
+    MEMFS_RENAME_CONTEXT *Context = (MEMFS_RENAME_CONTEXT *)Context0;
+
+    Context->FileNodes[Context->Count++] = FileNode;
+    FileNode->RefCount++;
+
+    return TRUE;
+}
+
 static NTSTATUS Rename(FSP_FILE_SYSTEM *FileSystem,
     FSP_FSCTL_TRANSACT_REQ *Request,
     PVOID FileNode0,
@@ -637,40 +669,88 @@ static NTSTATUS Rename(FSP_FILE_SYSTEM *FileSystem,
 {
     MEMFS *Memfs = (MEMFS *)FileSystem->UserContext;
     MEMFS_FILE_NODE *FileNode = (MEMFS_FILE_NODE *)FileNode0;
-    MEMFS_FILE_NODE *NewFileNode;
+    MEMFS_FILE_NODE *NewFileNode, *DescendantFileNode;
+    MEMFS_RENAME_CONTEXT Context = { 0 };
+    ULONG Index, FileNameLen, NewFileNameLen;
     BOOLEAN Inserted;
     NTSTATUS Result;
 
     assert(0 == FileName || 0 == wcscmp(FileNode->FileName, FileName));
 
-    if (MAX_PATH <= wcslen(NewFileName))
-        return STATUS_OBJECT_NAME_INVALID;
-
     NewFileNode = MemfsFileNodeMapGet(Memfs->FileNodeMap, NewFileName);
     if (0 != NewFileNode)
     {
         if (!ReplaceIfExists)
-            return STATUS_OBJECT_NAME_COLLISION;
+        {
+            Result = STATUS_OBJECT_NAME_COLLISION;
+            goto exit;
+        }
 
         if (NewFileNode->FileInfo.FileAttributes & FILE_ATTRIBUTE_DIRECTORY)
-            return STATUS_ACCESS_DENIED;
+        {
+            Result = STATUS_ACCESS_DENIED;
+            goto exit;
+        }
+    }
 
+    Context.FileNodes = (MEMFS_FILE_NODE **)malloc(Memfs->MaxFileNodes * sizeof Context.FileNodes[0]);
+    if (0 == Context.FileNodes)
+    {
+        Result = STATUS_INSUFFICIENT_RESOURCES;
+        goto exit;
+    }
+
+    MemfsFileNodeMapEnumerateDescendants(Memfs->FileNodeMap, FileNode, RenameEnumFn, &Context);
+
+    FileNameLen = (ULONG)wcslen(FileNode->FileName);
+    NewFileNameLen = (ULONG)wcslen(NewFileName);
+    for (Index = 0; Context.Count > Index; Index++)
+    {
+        DescendantFileNode = Context.FileNodes[Index];
+        assert(MemfsFileNameHasPrefix(DescendantFileNode->FileName, FileNode->FileName));
+        if (MAX_PATH <= wcslen(DescendantFileNode->FileName) - FileNameLen + NewFileNameLen)
+        {
+            Result = STATUS_OBJECT_NAME_INVALID;
+            goto exit;
+        }
+    }
+
+    if (0 != NewFileNode)
+    {
         NewFileNode->RefCount++;
         MemfsFileNodeMapRemove(Memfs->FileNodeMap, NewFileNode);
         if (0 == --NewFileNode->RefCount)
             MemfsFileNodeDelete(NewFileNode);
     }
 
-    MemfsFileNodeMapRemove(Memfs->FileNodeMap, FileNode);
+    for (Index = 0; Context.Count > Index; Index++)
-    wcscpy_s(FileNode->FileName, sizeof FileNode->FileName / sizeof(WCHAR), NewFileName);
+    {
-    Result = MemfsFileNodeMapInsert(Memfs->FileNodeMap, FileNode, &Inserted);
+        DescendantFileNode = Context.FileNodes[Index];
+        MemfsFileNodeMapRemove(Memfs->FileNodeMap, DescendantFileNode);
+        memmove(DescendantFileNode->FileName + NewFileNameLen,
+            DescendantFileNode->FileName + FileNameLen,
+            (wcslen(DescendantFileNode->FileName) + 1 - FileNameLen) * sizeof(WCHAR));
+        memcpy(DescendantFileNode->FileName, NewFileName, NewFileNameLen * sizeof(WCHAR));
+        Result = MemfsFileNodeMapInsert(Memfs->FileNodeMap, DescendantFileNode, &Inserted);
         if (!NT_SUCCESS(Result))
         {
             FspDebugLog(__FUNCTION__ ": cannot insert into FileNodeMap; aborting\n");
             abort();
         }
+        assert(Inserted);
+    }
 
-    return STATUS_SUCCESS;
+    Result = STATUS_SUCCESS;
+
+exit:
+    for (Index = 0; Context.Count > Index; Index++)
+    {
+        DescendantFileNode = Context.FileNodes[Index];
+        DescendantFileNode->RefCount--;
+    }
+    free(Context.FileNodes);
+
+    return Result;
 }
 
 static NTSTATUS GetSecurity(FSP_FILE_SYSTEM *FileSystem,