Centralise packet handling for common packets … (pkg#111)

* Centralise packet handling for common packets Updates pkg#84, pkg#95, pkg#96 * use sendError
austinyoo-pp · Jun 15, 2016 · 7f77924 · 7f77924
1 parent ea1a7bc
commit 7f77924
Showing 1 changed file with 107 additions and 125 deletions.
diff --git a/server.go b/server.go
@@ -122,7 +122,10 @@ type rxPacket struct {
 // Up to N parallel servers
 func (svr *Server) sftpServerWorker() error {
 	for p := range svr.pktChan {
-		var pkt serverRespondablePacket
+		var pkt interface {
+			encoding.BinaryUnmarshaler
+			id() uint32
+		}
 		var readonly = true
 		switch p.pktType {
 		case ssh_FXP_INIT:
@@ -181,7 +184,7 @@ func (svr *Server) sftpServerWorker() error {
 			return err
 		}
 
-		// handle SFP_OPENDIR specially
+		// handle FXP_OPENDIR specially
 		switch pkt := pkt.(type) {
 		case *sshFxpOpenPacket:
 			readonly = pkt.readonly()
@@ -198,14 +201,113 @@ func (svr *Server) sftpServerWorker() error {
 			continue
 		}
 
-		if err := pkt.respond(svr); err != nil {
-			return errors.Wrap(err, "pkt.respond failed")
+		if err := handlePacket(svr, pkt); err != nil {
+			return err
 		}
-
 	}
 	return nil
 }
 
+func handlePacket(s *Server, p interface{}) error {
+	switch p := p.(type) {
+	case *sshFxInitPacket:
+		return s.sendPacket(sshFxVersionPacket{sftpProtocolVersion, nil})
+	case *sshFxpStatPacket:
+		// stat the requested file
+		info, err := os.Stat(p.Path)
+		if err != nil {
+			return s.sendError(p, err)
+		}
+		return s.sendPacket(sshFxpStatResponse{
+			ID:   p.ID,
+			info: info,
+		})
+	case *sshFxpLstatPacket:
+		// stat the requested file
+		info, err := os.Lstat(p.Path)
+		if err != nil {
+			return s.sendError(p, err)
+		}
+		return s.sendPacket(sshFxpStatResponse{
+			ID:   p.ID,
+			info: info,
+		})
+	case *sshFxpFstatPacket:
+		f, ok := s.getHandle(p.Handle)
+		if !ok {
+			return s.sendError(p, syscall.EBADF)
+		}
+
+		info, err := f.Stat()
+		if err != nil {
+			return s.sendError(p, err)
+		}
+
+		return s.sendPacket(sshFxpStatResponse{
+			ID:   p.ID,
+			info: info,
+		})
+	case *sshFxpMkdirPacket:
+		// TODO FIXME: ignore flags field
+		err := os.Mkdir(p.Path, 0755)
+		return s.sendError(p, err)
+	case *sshFxpRmdirPacket:
+		err := os.Remove(p.Path)
+		return s.sendError(p, err)
+	case *sshFxpRemovePacket:
+		err := os.Remove(p.Filename)
+		return s.sendError(p, err)
+	case *sshFxpRenamePacket:
+		err := os.Rename(p.Oldpath, p.Newpath)
+		return s.sendError(p, err)
+	case *sshFxpSymlinkPacket:
+		err := os.Symlink(p.Targetpath, p.Linkpath)
+		return s.sendError(p, err)
+	case *sshFxpClosePacket:
+		return s.sendError(p, s.closeHandle(p.Handle))
+	case *sshFxpReadlinkPacket:
+		f, err := os.Readlink(p.Path)
+		if err != nil {
+			return s.sendError(p, err)
+		}
+
+		return s.sendPacket(sshFxpNamePacket{
+			ID: p.ID,
+			NameAttrs: []sshFxpNameAttr{{
+				Name:     f,
+				LongName: f,
+				Attrs:    emptyFileStat,
+			}},
+		})
+
+	case *sshFxpRealpathPacket:
+		f, err := filepath.Abs(p.Path)
+		if err != nil {
+			return s.sendError(p, err)
+		}
+		f = filepath.Clean(f)
+		return s.sendPacket(sshFxpNamePacket{
+			ID: p.ID,
+			NameAttrs: []sshFxpNameAttr{{
+				Name:     f,
+				LongName: f,
+				Attrs:    emptyFileStat,
+			}},
+		})
+	case *sshFxpOpendirPacket:
+		return sshFxpOpenPacket{
+			ID:     p.ID,
+			Path:   p.Path,
+			Pflags: ssh_FXF_READ,
+		}.respond(s)
+	case serverRespondablePacket:
+		err := p.respond(s)
+		return errors.Wrap(err, "pkt.respond failed")
+	default:
+		return errors.Errorf("unexpected packet type %T", p)
+	}
+}
+
 // Serve serves SFTP connections until the streams stop or the SFTP subsystem
 // is stopped.
 func (svr *Server) Serve() error {
@@ -250,10 +352,6 @@ func (s *Server) sendError(p id, err error) error {
 	return s.sendPacket(statusFromError(p, err))
 }
 
-func (p sshFxInitPacket) respond(svr *Server) error {
-	return svr.sendPacket(sshFxVersionPacket{sftpProtocolVersion, nil})
-}
-
 // The init packet has no ID, so we just return a zero-value ID
 func (p sshFxInitPacket) id() uint32 { return 0 }
 
@@ -269,119 +367,8 @@ func (p sshFxpStatResponse) MarshalBinary() ([]byte, error) {
 	return b, nil
 }
 
-func (p sshFxpLstatPacket) respond(svr *Server) error {
-	// stat the requested file
-	info, err := os.Lstat(p.Path)
-	if err != nil {
-		return svr.sendError(p, err)
-	}
-
-	return svr.sendPacket(sshFxpStatResponse{
-		ID:   p.ID,
-		info: info,
-	})
-}
-
-func (p sshFxpStatPacket) respond(svr *Server) error {
-	// stat the requested file
-	info, err := os.Stat(p.Path)
-	if err != nil {
-		return svr.sendError(p, err)
-	}
-
-	return svr.sendPacket(sshFxpStatResponse{
-		ID:   p.ID,
-		info: info,
-	})
-}
-
-func (p sshFxpFstatPacket) respond(svr *Server) error {
-	f, ok := svr.getHandle(p.Handle)
-	if !ok {
-		return svr.sendError(p, syscall.EBADF)
-	}
-
-	info, err := f.Stat()
-	if err != nil {
-		return svr.sendError(p, err)
-	}
-
-	return svr.sendPacket(sshFxpStatResponse{
-		ID:   p.ID,
-		info: info,
-	})
-}
-
-func (p sshFxpMkdirPacket) respond(svr *Server) error {
-	// TODO FIXME: ignore flags field
-	err := os.Mkdir(p.Path, 0755)
-	return svr.sendError(p, err)
-}
-
-func (p sshFxpRmdirPacket) respond(svr *Server) error {
-	err := os.Remove(p.Path)
-	return svr.sendError(p, err)
-}
-
-func (p sshFxpRemovePacket) respond(svr *Server) error {
-	err := os.Remove(p.Filename)
-	return svr.sendError(p, err)
-}
-
-func (p sshFxpRenamePacket) respond(svr *Server) error {
-	err := os.Rename(p.Oldpath, p.Newpath)
-	return svr.sendError(p, err)
-}
-
-func (p sshFxpSymlinkPacket) respond(svr *Server) error {
-	err := os.Symlink(p.Targetpath, p.Linkpath)
-	return svr.sendError(p, err)
-}
-
 var emptyFileStat = []interface{}{uint32(0)}
 
-func (p sshFxpReadlinkPacket) respond(svr *Server) error {
-	f, err := os.Readlink(p.Path)
-	if err != nil {
-		return svr.sendError(p, err)
-	}
-
-	return svr.sendPacket(sshFxpNamePacket{
-		ID: p.ID,
-		NameAttrs: []sshFxpNameAttr{{
-			Name:     f,
-			LongName: f,
-			Attrs:    emptyFileStat,
-		}},
-	})
-}
-
-func (p sshFxpRealpathPacket) respond(svr *Server) error {
-	f, err := filepath.Abs(p.Path)
-	if err != nil {
-		return svr.sendError(p, err)
-	}
-
-	f = filepath.Clean(f)
-
-	return svr.sendPacket(sshFxpNamePacket{
-		ID: p.ID,
-		NameAttrs: []sshFxpNameAttr{{
-			Name:     f,
-			LongName: f,
-			Attrs:    emptyFileStat,
-		}},
-	})
-}
-
-func (p sshFxpOpendirPacket) respond(svr *Server) error {
-	return sshFxpOpenPacket{
-		ID:     p.ID,
-		Path:   p.Path,
-		Pflags: ssh_FXF_READ,
-	}.respond(svr)
-}
-
 func (p sshFxpOpenPacket) readonly() bool {
 	return !p.hasPflags(ssh_FXF_WRITE)
 }
@@ -392,7 +379,6 @@ func (p sshFxpOpenPacket) hasPflags(flags ...uint32) bool {
 			return false
 		}
 	}
-
 	return true
 }
 
@@ -431,10 +417,6 @@ func (p sshFxpOpenPacket) respond(svr *Server) error {
 	return svr.sendPacket(sshFxpHandlePacket{p.ID, handle})
 }
 
-func (p sshFxpClosePacket) respond(svr *Server) error {
-	return svr.sendError(p, svr.closeHandle(p.Handle))
-}
-
 func (p sshFxpReadPacket) respond(svr *Server) error {
 	f, ok := svr.getHandle(p.Handle)
 	if !ok {