exploit the embedded FileStat in fileInfo

attrs.go

@@ -21,29 +21,26 @@ const (
 
 // fileInfo is an artificial type designed to satisfy os.FileInfo.
 type fileInfo struct {
-	name  string
-	size  int64
-	mode  os.FileMode
-	mtime time.Time
-	sys   interface{}
+	name string
+	stat *FileStat
 }
 
 // Name returns the base name of the file.
 func (fi *fileInfo) Name() string { return fi.name }
 
 // Size returns the length in bytes for regular files; system-dependent for others.
-func (fi *fileInfo) Size() int64 { return fi.size }
+func (fi *fileInfo) Size() int64 { return int64(fi.stat.Size) }
 
 // Mode returns file mode bits.
-func (fi *fileInfo) Mode() os.FileMode { return fi.mode }
+func (fi *fileInfo) Mode() os.FileMode { return toFileMode(fi.stat.Mode) }
 
 // ModTime returns the last modification time of the file.
-func (fi *fileInfo) ModTime() time.Time { return fi.mtime }
+func (fi *fileInfo) ModTime() time.Time { return time.Unix(int64(fi.stat.Mtime), 0) }
 
 // IsDir returns true if the file is a directory.
 func (fi *fileInfo) IsDir() bool { return fi.Mode().IsDir() }
 
-func (fi *fileInfo) Sys() interface{} { return fi.sys }
+func (fi *fileInfo) Sys() interface{} { return fi.stat }
 
 // FileStat holds the original unmarshalled values from a call to READDIR or
 // *STAT. It is exported for the purposes of accessing the raw values via
@@ -65,25 +62,21 @@ type StatExtended struct {
 	ExtData string
 }
 
-func fileInfoFromStat(st *FileStat, name string) os.FileInfo {
-	fs := &fileInfo{
-		name:  name,
-		size:  int64(st.Size),
-		mode:  toFileMode(st.Mode),
-		mtime: time.Unix(int64(st.Mtime), 0),
-		sys:   st,
+func fileInfoFromStat(stat *FileStat, name string) os.FileInfo {
+	return &fileInfo{
+		name: name,
+		stat: stat,
 	}
-	return fs
 }
 
-func fileStatFromInfo(fi os.FileInfo) (uint32, FileStat) {
+func fileStatFromInfo(fi os.FileInfo) (uint32, *FileStat) {
 	mtime := fi.ModTime().Unix()
 	atime := mtime
 	var flags uint32 = sshFileXferAttrSize |
 		sshFileXferAttrPermissions |
 		sshFileXferAttrACmodTime
 
-	fileStat := FileStat{
+	fileStat := &FileStat{
 		Size:  uint64(fi.Size()),
 		Mode:  fromFileMode(fi.Mode()),
 		Mtime: uint32(mtime),
@@ -91,7 +84,7 @@ func fileStatFromInfo(fi os.FileInfo) (uint32, FileStat) {
 	}
 
 	// os specific file stat decoding
-	fileStatFromInfoOs(fi, &flags, &fileStat)
+	fileStatFromInfoOs(fi, &flags, fileStat)
 
 	return flags, fileStat
 }