vendor: Update vendoring for the exec client and server implementations

Signed-off-by: Jacek J. Łakis <jacek.lakis@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

vendor/github.com/kr/pty/pty_dragonfly.go

@@ -0,0 +1,76 @@
+package pty
+
+import (
+	"errors"
+	"os"
+	"strings"
+	"syscall"
+	"unsafe"
+)
+
+// same code as pty_darwin.go
+func open() (pty, tty *os.File, err error) {
+	p, err := os.OpenFile("/dev/ptmx", os.O_RDWR, 0)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	sname, err := ptsname(p)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	err = grantpt(p)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	err = unlockpt(p)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	t, err := os.OpenFile(sname, os.O_RDWR, 0)
+	if err != nil {
+		return nil, nil, err
+	}
+	return p, t, nil
+}
+
+func grantpt(f *os.File) error {
+	_, err := isptmaster(f.Fd())
+	return err
+}
+
+func unlockpt(f *os.File) error {
+	_, err := isptmaster(f.Fd())
+	return err
+}
+
+func isptmaster(fd uintptr) (bool, error) {
+	err := ioctl(fd, syscall.TIOCISPTMASTER, 0)
+	return err == nil, err
+}
+
+var (
+	emptyFiodgnameArg fiodgnameArg
+	ioctl_FIODNAME    = _IOW('f', 120, unsafe.Sizeof(emptyFiodgnameArg))
+)
+
+func ptsname(f *os.File) (string, error) {
+	name := make([]byte, _C_SPECNAMELEN)
+	fa := fiodgnameArg{Name: (*byte)(unsafe.Pointer(&name[0])), Len: _C_SPECNAMELEN, Pad_cgo_0: [4]byte{0, 0, 0, 0}}
+
+	err := ioctl(f.Fd(), ioctl_FIODNAME, uintptr(unsafe.Pointer(&fa)))
+	if err != nil {
+		return "", err
+	}
+
+	for i, c := range name {
+		if c == 0 {
+			s := "/dev/" + string(name[:i])
+			return strings.Replace(s, "ptm", "pts", -1), nil
+		}
+	}
+	return "", errors.New("TIOCPTYGNAME string not NUL-terminated")
+}