vendor: update c/common

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

vendor/github.com/pkg/sftp/server_windows.go

@@ -1,8 +1,15 @@
 package sftp
 
 import (
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
 	"path"
 	"path/filepath"
+	"time"
+
+	"golang.org/x/sys/windows"
 )
 
 func (s *Server) toLocalPath(p string) string {
@@ -12,7 +19,11 @@ func (s *Server) toLocalPath(p string) string {
 
 	lp := filepath.FromSlash(p)
 
-	if path.IsAbs(p) {
+	if path.IsAbs(p) { // starts with '/'
+		if len(p) == 1 && s.winRoot {
+			return `\\.\` // for openfile
+		}
+
 		tmp := lp
 		for len(tmp) > 0 && tmp[0] == '\\' {
 			tmp = tmp[1:]
@@ -33,7 +44,150 @@ func (s *Server) toLocalPath(p string) string {
 			// e.g. "/C:" to "C:\\"
 			return tmp
 		}
+
+		if s.winRoot {
+			// Make it so that "/Windows" is not found, and "/c:/Windows" has to be used
+			return `\\.\` + tmp
+		}
 	}
 
 	return lp
 }
+
+func bitsToDrives(bitmap uint32) []string {
+	var drive rune = 'a'
+	var drives []string
+
+	for bitmap != 0 && drive <= 'z' {
+		if bitmap&1 == 1 {
+			drives = append(drives, string(drive)+":")
+		}
+		drive++
+		bitmap >>= 1
+	}
+
+	return drives
+}
+
+func getDrives() ([]string, error) {
+	mask, err := windows.GetLogicalDrives()
+	if err != nil {
+		return nil, fmt.Errorf("GetLogicalDrives: %w", err)
+	}
+	return bitsToDrives(mask), nil
+}
+
+type driveInfo struct {
+	fs.FileInfo
+	name string
+}
+
+func (i *driveInfo) Name() string {
+	return i.name // since the Name() returned from a os.Stat("C:\\") is "\\"
+}
+
+type winRoot struct {
+	drives []string
+}
+
+func newWinRoot() (*winRoot, error) {
+	drives, err := getDrives()
+	if err != nil {
+		return nil, err
+	}
+	return &winRoot{
+		drives: drives,
+	}, nil
+}
+
+func (f *winRoot) Readdir(n int) ([]os.FileInfo, error) {
+	drives := f.drives
+	if n > 0 && len(drives) > n {
+		drives = drives[:n]
+	}
+	f.drives = f.drives[len(drives):]
+	if len(drives) == 0 {
+		return nil, io.EOF
+	}
+
+	var infos []os.FileInfo
+	for _, drive := range drives {
+		fi, err := os.Stat(drive + `\`)
+		if err != nil {
+			return nil, err
+		}
+
+		di := &driveInfo{
+			FileInfo: fi,
+			name:     drive,
+		}
+		infos = append(infos, di)
+	}
+
+	return infos, nil
+}
+
+func (f *winRoot) Stat() (os.FileInfo, error) {
+	return rootFileInfo, nil
+}
+func (f *winRoot) ReadAt(b []byte, off int64) (int, error) {
+	return 0, os.ErrPermission
+}
+func (f *winRoot) WriteAt(b []byte, off int64) (int, error) {
+	return 0, os.ErrPermission
+}
+func (f *winRoot) Name() string {
+	return "/"
+}
+func (f *winRoot) Truncate(int64) error {
+	return os.ErrPermission
+}
+func (f *winRoot) Chmod(mode fs.FileMode) error {
+	return os.ErrPermission
+}
+func (f *winRoot) Chown(uid, gid int) error {
+	return os.ErrPermission
+}
+func (f *winRoot) Close() error {
+	f.drives = nil
+	return nil
+}
+
+func (s *Server) openfile(path string, flag int, mode fs.FileMode) (file, error) {
+	if path == `\\.\` && s.winRoot {
+		return newWinRoot()
+	}
+	return os.OpenFile(path, flag, mode)
+}
+
+type winRootFileInfo struct {
+	name    string
+	modTime time.Time
+}
+
+func (w *winRootFileInfo) Name() string       { return w.name }
+func (w *winRootFileInfo) Size() int64        { return 0 }
+func (w *winRootFileInfo) Mode() fs.FileMode  { return fs.ModeDir | 0555 } // read+execute for all
+func (w *winRootFileInfo) ModTime() time.Time { return w.modTime }
+func (w *winRootFileInfo) IsDir() bool        { return true }
+func (w *winRootFileInfo) Sys() interface{}   { return nil }
+
+// Create a new root FileInfo
+var rootFileInfo = &winRootFileInfo{
+	name:    "/",
+	modTime: time.Now(),
+}
+
+func (s *Server) lstat(name string) (os.FileInfo, error) {
+	if name == `\\.\` && s.winRoot {
+		return rootFileInfo, nil
+	}
+	return os.Lstat(name)
+}
+
+func (s *Server) stat(name string) (os.FileInfo, error) {
+	if name == `\\.\` && s.winRoot {
+		return rootFileInfo, nil
+	}
+	return os.Stat(name)
+}