term: fix own implementation

Signed-off-by: Nobuhiro MIKI <[email protected]>

go.mod

@@ -1,5 +1,3 @@
 module github.com/nmi/gokvm
 
 go 1.13
-
-require golang.org/x/term v0.0.0-20201210144234-2321bbc49cbf

kvm/kvm.go

@@ -157,7 +157,6 @@ func (r *UserspaceMemoryRegion) SetMemReadonly() {
 }
 
 func ioctl(fd, op, arg uintptr) (uintptr, error) {
-	// fmt.Printf("ioctl called.\n")
 	res, _, errno := syscall.Syscall(
 		syscall.SYS_IOCTL, fd, op, arg)
 

main.go

@@ -2,13 +2,10 @@ package main
 
 import (
 	"bufio"
-	"log"
 	"os"
 
 	"github.com/nmi/gokvm/machine"
-
-	// change to own library.
-	"golang.org/x/term"
+	"github.com/nmi/gokvm/term"
 )
 
 func main() {
@@ -27,17 +24,12 @@ func main() {
 		}
 	}()
 
-	// fd 0 is stdin
-	state, err := term.MakeRaw(0)
+	restoreMode, err := term.SetRawMode()
 	if err != nil {
-		log.Fatalln("setting stdin to raw:", err)
+		panic(err)
 	}
 
-	defer func() {
-		if err := term.Restore(0, state); err != nil {
-			log.Println("warning, failed to restore terminal:", err)
-		}
-	}()
+	defer restoreMode()
 
 	var before byte = 0
 
@@ -46,9 +38,7 @@ func main() {
 	for {
 		b, err := in.ReadByte()
 		if err != nil {
-			log.Println("stdin:", err)
-
-			break
+			panic(err)
 		}
 		m.GetInputChan() <- b
 

term/term.go

@@ -0,0 +1,66 @@
+package term
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+type termios struct {
+	Iflag  uint32
+	Oflag  uint32
+	Cflag  uint32
+	Lflag  uint32
+	Line   uint8
+	Cc     [19]uint8
+	Ispeed uint32
+	Ospeed uint32
+}
+
+func read(fd int) (termios, error) {
+	var t termios
+
+	_, _, errno := syscall.Syscall(
+		syscall.SYS_IOCTL, uintptr(fd), 0x5401,
+		uintptr(unsafe.Pointer(&t)))
+
+	var err error = nil
+	if errno != 0 {
+		err = errno
+	}
+
+	return t, err
+}
+
+func write(fd int, t termios) error {
+	_, _, errno := syscall.Syscall(
+		syscall.SYS_IOCTL, uintptr(fd), 0x5402,
+		uintptr(unsafe.Pointer(&t)))
+
+	var err error = nil
+	if errno != 0 {
+		err = errno
+	}
+
+	return err
+}
+
+func SetRawMode() (func(), error) {
+	t, err := read(0)
+	if err != nil {
+		return func() {}, err
+	}
+
+	oldTermios := t
+
+	t.Iflag &^= 0b10111101011
+	t.Oflag &^= 1
+	t.Lflag &^= 0b1000000001001011
+	t.Cflag &^= 0b01001000 | 0b100000000
+	t.Cflag |= 48
+	t.Cc[6] = 1
+	t.Cc[5] = 0
+
+	return func() {
+		_ = write(0, oldTermios)
+	}, write(0, t)
+}