Don't treat certain "expected" errors from the filesystem as 500 errors; closes pterodactyl/panel#2376

router/router_server_files.go

@@ -247,6 +247,13 @@ func postServerWriteFile(c *gin.Context) {
 	f = "/" + strings.TrimLeft(f, "/")
 
 	if err := s.Filesystem.Writefile(f, c.Request.Body); err != nil {
+		if errors.Is(err, server.ErrIsDirectory) {
+			c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{
+				"error": "Cannot write file, name conflicts with an existing directory by the same name.",
+			})
+			return
+		}
+
 		TrackedServerError(err, s).AbortWithServerError(c)
 		return
 	}
@@ -268,6 +275,13 @@ func postServerCreateDirectory(c *gin.Context) {
 	}
 
 	if err := s.Filesystem.CreateDirectory(data.Name, data.Path); err != nil {
+		if err.Error() == "not a directory" {
+			c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{
+				"error": "Part of the path being created is not a directory (ENOTDIR).",
+			})
+			return
+		}
+
 		TrackedServerError(err, s).AbortWithServerError(c)
 		return
 	}

server/filesystem.go

@@ -29,6 +29,7 @@ import (
 // Error returned when there is a bad path provided to one of the FS calls.
 type PathResolutionError struct{}
 
+var ErrIsDirectory = errors.New("is a directory")
 var ErrNotEnoughDiskSpace = errors.New("not enough disk space is available to perform this operation")
 
 // Returns the error response in a string form that can be more easily consumed.
@@ -396,7 +397,7 @@ func (fs *Filesystem) Writefile(p string, r io.Reader) error {
 		}
 	} else {
 		if stat.IsDir() {
-			return errors.New("cannot write file contents to a directory")
+			return ErrIsDirectory
 		}
 
 		currentSize = stat.Size()