review adjustments

Author: powellnorma

server.go

@@ -22,7 +22,7 @@ const (
 	SftpServerWorkerCount = 8
 )
 
-type FileLike interface {
+type file interface {
 	Stat() (os.FileInfo, error)
 	ReadAt(b []byte, off int64) (int, error)
 	WriteAt(b []byte, off int64) (int, error)
@@ -76,13 +76,13 @@ type Server struct {
 	debugStream   io.Writer
 	readOnly      bool
 	pktMgr        *packetManager
-	openFiles     map[string]FileLike
+	openFiles     map[string]file
 	openFilesLock sync.RWMutex
 	handleCount   int
 	workDir       string
 }
 
-func (svr *Server) nextHandle(f FileLike) string {
+func (svr *Server) nextHandle(f file) string {
 	svr.openFilesLock.Lock()
 	defer svr.openFilesLock.Unlock()
 	svr.handleCount++
@@ -102,7 +102,7 @@ func (svr *Server) closeHandle(handle string) error {
 	return EBADF
 }
 
-func (svr *Server) getHandle(handle string) (FileLike, bool) {
+func (svr *Server) getHandle(handle string) (file, bool) {
 	svr.openFilesLock.RLock()
 	defer svr.openFilesLock.RUnlock()
 	f, ok := svr.openFiles[handle]
@@ -131,7 +131,7 @@ func NewServer(rwc io.ReadWriteCloser, options ...ServerOption) (*Server, error)
 		serverConn:  svrConn,
 		debugStream: ioutil.Discard,
 		pktMgr:      newPktMgr(svrConn),
-		openFiles:   make(map[string]FileLike),
+		openFiles:   make(map[string]file),
 	}
 
 	for _, o := range options {
@@ -508,7 +508,7 @@ func (p *sshFxpOpenPacket) respond(svr *Server) responsePacket {
 		osFlags |= os.O_EXCL
 	}
 
-	f, err := openFileLike(svr.toLocalPath(p.Path), osFlags, 0o644)
+	f, err := openfile(svr.toLocalPath(p.Path), osFlags, 0o644)
 	if err != nil {
 		return statusFromError(p.ID, err)
 	}

server_posix.go

@@ -8,6 +8,6 @@ import (
 	"os"
 )
 
-func openFileLike(path string, flag int, mode fs.FileMode) (FileLike, error) {
+func openfile(path string, flag int, mode fs.FileMode) (file, error) {
 	return os.OpenFile(path, flag, mode)
 }

server_windows.go

@@ -4,12 +4,13 @@ package sftp
 
 import (
 	"fmt"
+	"io"
 	"io/fs"
 	"os"
 	"path"
 	"path/filepath"
-	"syscall"
-	"time"
+
+	"golang.org/x/sys/windows"
 )
 
 func (s *Server) toLocalPath(p string) string {
@@ -45,16 +46,13 @@ func (s *Server) toLocalPath(p string) string {
 	return lp
 }
 
-var kernel32, _ = syscall.LoadLibrary("kernel32.dll")
-var getLogicalDrivesHandle, _ = syscall.GetProcAddress(kernel32, "GetLogicalDrives")
-
 func bitsToDrives(bitmap uint32) []string {
-	var drive rune = 'A'
+	var drive rune = 'a'
 	var drives []string
 
 	for bitmap != 0 {
 		if bitmap&1 == 1 {
-			drives = append(drives, string(drive))
+			drives = append(drives, string(drive)+":")
 		}
 		drive++
 		bitmap >>= 1
@@ -64,56 +62,63 @@ func bitsToDrives(bitmap uint32) []string {
 }
 
 func getDrives() ([]string, error) {
-	if ret, _, callErr := syscall.Syscall(uintptr(getLogicalDrivesHandle), 0, 0, 0, 0); callErr != 0 {
-		return nil, fmt.Errorf("GetLogicalDrives: %w", callErr)
-	} else {
-		drives := bitsToDrives(uint32(ret))
-		return drives, nil
+	mask, err := windows.GetLogicalDrives()
+	if err != nil {
+		return nil, fmt.Errorf("GetLogicalDrives: %w", err)
 	}
+	return bitsToDrives(mask), nil
 }
 
-type dummyDriveStat struct {
+type driveInfo struct {
+	fs.FileInfo
 	name string
 }
 
-func (s *dummyDriveStat) Name() string {
-	return s.name
-}
-func (s *dummyDriveStat) Size() int64 {
-	return 1024
-}
-func (s *dummyDriveStat) Mode() os.FileMode {
-	return os.FileMode(0755)
-}
-func (s *dummyDriveStat) ModTime() time.Time {
-	return time.Now()
-}
-func (s *dummyDriveStat) IsDir() bool {
-	return true
-}
-func (s *dummyDriveStat) Sys() any {
-	return nil
+func (i *driveInfo) Name() string {
+	return i.name // since the Name() returned from a os.Stat("C:\\") is "\\"
 }
 
-type WinRoot struct {
+type winRoot struct {
 	dummyFile
+	doneDirs int
 }
 
-func (f *WinRoot) Readdir(int) ([]os.FileInfo, error) {
+func (f *winRoot) Readdir(n int) ([]os.FileInfo, error) {
 	drives, err := getDrives()
 	if err != nil {
 		return nil, err
 	}
-	infos := []os.FileInfo{}
-	for _, drive := range drives {
-		infos = append(infos, &dummyDriveStat{drive})
+
+	if f.doneDirs >= len(drives) {
+		return nil, io.EOF
 	}
+	drives = drives[f.doneDirs:]
+
+	var infos []os.FileInfo
+	for i, drive := range drives {
+		if i >= n {
+			break
+		}
+
+		fi, err := os.Stat(drive)
+		if err != nil {
+			return nil, err
+		}
+
+		di := &driveInfo{
+			FileInfo: fi,
+			name:     drive,
+		}
+		infos = append(infos, di)
+	}
+
+	f.doneDirs += len(infos)
 	return infos, nil
 }
 
-func openFileLike(path string, flag int, mode fs.FileMode) (FileLike, error) {
+func openfile(path string, flag int, mode fs.FileMode) (file, error) {
 	if path == "/" {
-		return &WinRoot{}, nil
+		return &winRoot{}, nil
 	}
 	return os.OpenFile(path, flag, mode)
 }