| package pty |
| |
| /* based on: |
| http://src.illumos.org/source/xref/illumos-gate/usr/src/lib/libc/port/gen/pt.c |
| */ |
| |
| import ( |
| "errors" |
| "golang.org/x/sys/unix" |
| "os" |
| "strconv" |
| "syscall" |
| "unsafe" |
| ) |
| |
| const NODEV = ^uint64(0) |
| |
| func open() (pty, tty *os.File, err error) { |
| masterfd, err := syscall.Open("/dev/ptmx", syscall.O_RDWR|unix.O_NOCTTY, 0) |
| //masterfd, err := syscall.Open("/dev/ptmx", syscall.O_RDWR|syscall.O_CLOEXEC|unix.O_NOCTTY, 0) |
| if err != nil { |
| return nil, nil, err |
| } |
| p := os.NewFile(uintptr(masterfd), "/dev/ptmx") |
| |
| 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 |
| } |
| |
| slavefd, err := syscall.Open(sname, os.O_RDWR|unix.O_NOCTTY, 0) |
| if err != nil { |
| return nil, nil, err |
| } |
| t := os.NewFile(uintptr(slavefd), sname) |
| |
| // pushing terminal driver STREAMS modules as per pts(7) |
| for _, mod := range([]string{"ptem", "ldterm", "ttcompat"}) { |
| err = streams_push(t, mod) |
| if err != nil { |
| return nil, nil, err |
| } |
| } |
| |
| return p, t, nil |
| } |
| |
| func minor(x uint64) uint64 { |
| return x & 0377 |
| } |
| |
| func ptsdev(fd uintptr) uint64 { |
| istr := strioctl{ISPTM, 0, 0, nil} |
| err := ioctl(fd, I_STR, uintptr(unsafe.Pointer(&istr))) |
| if err != nil { |
| return NODEV |
| } |
| var status unix.Stat_t |
| err = unix.Fstat(int(fd), &status) |
| if err != nil { |
| return NODEV |
| } |
| return uint64(minor(status.Rdev)) |
| } |
| |
| func ptsname(f *os.File) (string, error) { |
| dev := ptsdev(f.Fd()) |
| if dev == NODEV { |
| return "", errors.New("not a master pty") |
| } |
| fn := "/dev/pts/" + strconv.FormatInt(int64(dev), 10) |
| // access(2) creates the slave device (if the pty exists) |
| // F_OK == 0 (unistd.h) |
| err := unix.Access(fn, 0) |
| if err != nil { |
| return "", err |
| } |
| return fn, nil |
| } |
| |
| type pt_own struct { |
| pto_ruid int32 |
| pto_rgid int32 |
| } |
| |
| func grantpt(f *os.File) error { |
| if ptsdev(f.Fd()) == NODEV { |
| return errors.New("not a master pty") |
| } |
| var pto pt_own |
| pto.pto_ruid = int32(os.Getuid()) |
| // XXX should first attempt to get gid of DEFAULT_TTY_GROUP="tty" |
| pto.pto_rgid = int32(os.Getgid()) |
| var istr strioctl |
| istr.ic_cmd = OWNERPT |
| istr.ic_timout = 0 |
| istr.ic_len = int32(unsafe.Sizeof(istr)) |
| istr.ic_dp = unsafe.Pointer(&pto) |
| err := ioctl(f.Fd(), I_STR, uintptr(unsafe.Pointer(&istr))) |
| if err != nil { |
| return errors.New("access denied") |
| } |
| return nil |
| } |
| |
| func unlockpt(f *os.File) error { |
| istr := strioctl{UNLKPT, 0, 0, nil} |
| return ioctl(f.Fd(), I_STR, uintptr(unsafe.Pointer(&istr))) |
| } |
| |
| // push STREAMS modules if not already done so |
| func streams_push(f *os.File, mod string) error { |
| var err error |
| buf := []byte(mod) |
| // XXX I_FIND is not returning an error when the module |
| // is already pushed even though truss reports a return |
| // value of 1. A bug in the Go Solaris syscall interface? |
| // XXX without this we are at risk of the issue |
| // https://www.illumos.org/issues/9042 |
| // but since we are not using libc or XPG4.2, we should not be |
| // double-pushing modules |
| |
| err = ioctl(f.Fd(), I_FIND, uintptr(unsafe.Pointer(&buf[0]))) |
| if err != nil { |
| return nil |
| } |
| err = ioctl(f.Fd(), I_PUSH, uintptr(unsafe.Pointer(&buf[0]))) |
| return err |
| } |