From e9fe4226256da367a1a627f1788a6530ab3109b4 Mon Sep 17 00:00:00 2001
From: Iain Buclaw <ibuclaw@gdcproject.org>
Date: Sun, 16 May 2021 18:17:26 +0200
Subject: [PATCH] Add support for NetBSD 386/amd64/arm (#117)

---
 mktypes.bash               |  2 +-
 pty_netbsd.go              | 66 ++++++++++++++++++++++++++++++++++++++
 pty_unsupported.go         |  2 +-
 types_netbsd.go            | 15 +++++++++
 ztypes_netbsd_32bit_int.go | 14 ++++++++
 5 files changed, 97 insertions(+), 2 deletions(-)
 create mode 100644 pty_netbsd.go
 create mode 100644 types_netbsd.go
 create mode 100644 ztypes_netbsd_32bit_int.go

diff --git a/mktypes.bash b/mktypes.bash
index 82ee167..7f71bda 100755
--- a/mktypes.bash
+++ b/mktypes.bash
@@ -13,7 +13,7 @@ GODEFS="go tool cgo -godefs"
 $GODEFS types.go |gofmt > ztypes_$GOARCH.go
 
 case $GOOS in
-freebsd|dragonfly|openbsd)
+freebsd|dragonfly|netbsd|openbsd)
 	$GODEFS types_$GOOS.go |gofmt > ztypes_$GOOSARCH.go
 	;;
 esac
diff --git a/pty_netbsd.go b/pty_netbsd.go
new file mode 100644
index 0000000..20f9125
--- /dev/null
+++ b/pty_netbsd.go
@@ -0,0 +1,66 @@
+package pty
+
+import (
+	"errors"
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+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
+	}
+	// In case of error after this point, make sure we close the ptmx fd.
+	defer func() {
+		if err != nil {
+			_ = p.Close() // Best effort.
+		}
+	}()
+
+	sname, err := ptsname(p)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	if err := grantpt(p); err != nil {
+		return nil, nil, err
+	}
+
+	// In NetBSD unlockpt() does nothing, so it isn't called here.
+
+	t, err := os.OpenFile(sname, os.O_RDWR|syscall.O_NOCTTY, 0)
+	if err != nil {
+		return nil, nil, err
+	}
+	return p, t, nil
+}
+
+func ptsname(f *os.File) (string, error) {
+	/*
+	 * from ptsname(3): The ptsname() function is equivalent to:
+	 * struct ptmget pm;
+	 * ioctl(fd, TIOCPTSNAME, &pm) == -1 ? NULL : pm.sn;
+	 */
+	var ptm ptmget
+	if err := ioctl(f.Fd(), uintptr(ioctl_TIOCPTSNAME), uintptr(unsafe.Pointer(&ptm))); err != nil {
+		return "", err
+	}
+	name := make([]byte, len(ptm.Sn))
+	for i, c := range ptm.Sn {
+		name[i] = byte(c)
+		if c == 0 {
+			return string(name[:i]), nil
+		}
+	}
+	return "", errors.New("TIOCPTSNAME string not NUL-terminated")
+}
+
+func grantpt(f *os.File) error {
+	/*
+	 * from grantpt(3): Calling grantpt() is equivalent to:
+	 * ioctl(fd, TIOCGRANTPT, 0);
+	 */
+	return ioctl(f.Fd(), uintptr(ioctl_TIOCGRANTPT), 0)
+}
diff --git a/pty_unsupported.go b/pty_unsupported.go
index ceb425b..6cd757b 100644
--- a/pty_unsupported.go
+++ b/pty_unsupported.go
@@ -1,4 +1,4 @@
-// +build !linux,!darwin,!freebsd,!dragonfly,!openbsd,!solaris
+// +build !linux,!darwin,!freebsd,!dragonfly,!netbsd,!openbsd,!solaris
 
 package pty
 
diff --git a/types_netbsd.go b/types_netbsd.go
new file mode 100644
index 0000000..52ebea7
--- /dev/null
+++ b/types_netbsd.go
@@ -0,0 +1,15 @@
+// +build ignore
+
+package pty
+
+/*
+#include <sys/time.h>
+#include <stdlib.h>
+#include <sys/tty.h>
+*/
+import "C"
+
+type ptmget C.struct_ptmget
+
+var ioctl_TIOCPTSNAME = C.TIOCPTSNAME
+var ioctl_TIOCGRANTPT = C.TIOCGRANTPT
diff --git a/ztypes_netbsd_32bit_int.go b/ztypes_netbsd_32bit_int.go
new file mode 100644
index 0000000..f40a5a6
--- /dev/null
+++ b/ztypes_netbsd_32bit_int.go
@@ -0,0 +1,14 @@
+// +build netbsd
+// +build 386 amd64 arm arm64
+
+package pty
+
+type ptmget struct {
+	Cfd int32
+	Sfd int32
+	Cn  [1024]int8
+	Sn  [1024]int8
+}
+
+var ioctl_TIOCPTSNAME = 0x48087448
+var ioctl_TIOCGRANTPT = 0x20007447