Added pty lib to give true terminal capability. raw mode/restore for client working

demo/client/client.go

@@ -10,6 +10,7 @@ import (
 	"sync"
 
 	hkex "blitter.com/herradurakex"
+	"golang.org/x/sys/unix"
 )
 
 // Demo of a simple client that dials up to a simple test server to
@@ -45,6 +46,13 @@ func main() {
 	}
 	defer conn.Close()
 
+	// Set stdin in raw mode.
+	oldState, err := MakeRaw(int(os.Stdin.Fd()))
+	if err != nil {
+		panic(err)
+	}
+	defer func() { _ = Restore(int(os.Stdin.Fd()), oldState) }() // Best effort.
+
 	wg.Add(1)
 	go func() {
 		// This will guarantee the side that closes first
@@ -64,7 +72,7 @@ func main() {
 				os.Exit(1)
 			}
 		}
-		fmt.Println("[Got Write EOF]")
+		log.Println("[Got Write EOF]")
 		wg.Done() // client hanging up, close server read goroutine
 	}()
 
@@ -81,10 +89,68 @@ func main() {
 				os.Exit(2)
 			}
 		}
-		fmt.Println("[Got Read EOF]")
+		log.Println("[Got Read EOF]")
 		wg.Done() // server hung up, close client write goroutine
 	}()
 
 	// Wait until both stdin and stdout goroutines finish
 	wg.Wait()
 }
+
+/* ------------- minimal terminal APIs brought in from ssh/terminal
+ * (they have no real business being there as they aren't specific to
+ * ssh.)
+ * -------------
+ */
+
+const ioctlReadTermios = unix.TCGETS
+const ioctlWriteTermios = unix.TCSETS
+
+// State contains the state of a terminal.
+type State struct {
+	termios unix.Termios
+}
+
+// MakeRaw put the terminal connected to the given file descriptor into raw
+// mode and returns the previous state of the terminal so that it can be
+// restored.
+func MakeRaw(fd int) (*State, error) {
+	termios, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
+	if err != nil {
+		return nil, err
+	}
+
+	oldState := State{termios: *termios}
+
+	// This attempts to replicate the behaviour documented for cfmakeraw in
+	// the termios(3) manpage.
+	termios.Iflag &^= unix.IGNBRK | unix.BRKINT | unix.PARMRK | unix.ISTRIP | unix.INLCR | unix.IGNCR | unix.ICRNL | unix.IXON
+	termios.Oflag &^= unix.OPOST
+	termios.Lflag &^= unix.ECHO | unix.ECHONL | unix.ICANON | unix.ISIG | unix.IEXTEN
+	termios.Cflag &^= unix.CSIZE | unix.PARENB
+	termios.Cflag |= unix.CS8
+	termios.Cc[unix.VMIN] = 1
+	termios.Cc[unix.VTIME] = 0
+	if err := unix.IoctlSetTermios(fd, ioctlWriteTermios, termios); err != nil {
+		return nil, err
+	}
+
+	return &oldState, nil
+}
+
+// GetState returns the current state of a terminal which may be useful to
+// restore the terminal after a signal.
+func GetState(fd int) (*State, error) {
+	termios, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
+	if err != nil {
+		return nil, err
+	}
+
+	return &State{termios: *termios}, nil
+}
+
+// Restore restores the terminal connected to the given file descriptor to a
+// previous state.
+func Restore(fd int, state *State) error {
+	return unix.IoctlSetTermios(fd, ioctlWriteTermios, &state.termios)
+}

demo/server/server.go

@@ -3,6 +3,7 @@ package main
 import (
 	"flag"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"log"
 	"os/exec"
@@ -12,6 +13,7 @@ import (
 	"time"
 
 	hkex "blitter.com/herradurakex"
+	"github.com/kr/pty"
 )
 
 const (
@@ -37,6 +39,60 @@ type cmdRunner struct {
 	status     int
 }
 
+/* ------------- minimal terminal APIs brought in from ssh/terminal
+ * (they have no real business being there as they aren't specific to
+ * ssh.)
+ * -------------
+ */
+
+/*
+// MakeRaw put the terminal connected to the given file descriptor into raw
+// mode and returns the previous state of the terminal so that it can be
+// restored.
+func MakeRaw(fd int) (*State, error) {
+	termios, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
+	if err != nil {
+		return nil, err
+	}
+
+	oldState := State{termios: *termios}
+
+	// This attempts to replicate the behaviour documented for cfmakeraw in
+	// the termios(3) manpage.
+	termios.Iflag &^= unix.IGNBRK | unix.BRKINT | unix.PARMRK | unix.ISTRIP | unix.INLCR | unix.IGNCR | unix.ICRNL | unix.IXON
+	termios.Oflag &^= unix.OPOST
+	termios.Lflag &^= unix.ECHO | unix.ECHONL | unix.ICANON | unix.ISIG | unix.IEXTEN
+	termios.Cflag &^= unix.CSIZE | unix.PARENB
+	termios.Cflag |= unix.CS8
+	termios.Cc[unix.VMIN] = 1
+	termios.Cc[unix.VTIME] = 0
+	if err := unix.IoctlSetTermios(fd, ioctlWriteTermios, termios); err != nil {
+		return nil, err
+	}
+
+	return &oldState, nil
+}
+
+// GetState returns the current state of a terminal which may be useful to
+// restore the terminal after a signal.
+func GetState(fd int) (*State, error) {
+	termios, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
+	if err != nil {
+		return nil, err
+	}
+
+	return &State{termios: *termios}, nil
+}
+
+// Restore restores the terminal connected to the given file descriptor to a
+// previous state.
+func Restore(fd int, state *State) error {
+	return unix.IoctlSetTermios(fd, ioctlWriteTermios, &state.termios)
+}
+*/
+
+/* -------------------------------------------------------------- */
+
 /*
  func cmd(r *cmdRunner) {
 	switch r.op {
@@ -72,7 +128,19 @@ func runCmdAs(who string, cmd string, conn hkex.Conn) (err error) {
 	c.Stdout = conn
 	c.Stderr = conn
 
-	err = c.Run()
+	// Start the command with a pty.
+	ptmx, err := pty.Start(c) // returns immediately with ptmx file
+	if err != nil {
+		return err
+	}
+	// Make sure to close the pty at the end.
+	defer func() { _ = ptmx.Close() }() // Best effort.
+	// Copy stdin to the pty and the pty to stdout.
+	go func() { _, _ = io.Copy(ptmx, conn) }()
+	_, _ = io.Copy(conn, ptmx)
+
+	//err = c.Run()  // returns when c finishes.
+
 	if err != nil {
 		log.Printf("Command finished with error: %v", err)
 		log.Printf("[%s]\n", cmd)
@@ -175,6 +243,7 @@ func main() {
 						// Clear current op so user can enter next, or EOF
 						connOp = nil
 						fmt.Println("[Exiting shell]")
+						conn.Close()
 					}
 					if strings.Trim(string(data), "\r\n") == "exit" {
 						conn.Close()

hkexnet.go

@@ -175,7 +175,7 @@ func Dial(protocol string, ipport string, extensions ...string) (hc *Conn, err e
 // Close a hkex.Conn
 func (c Conn) Close() (err error) {
 	err = c.c.Close()
-	fmt.Println("[Conn Closing]")
+	log.Println("[Conn Closing]")
 	return
 }
 
@@ -241,7 +241,7 @@ func Listen(protocol string, ipport string) (hl HKExListener, e error) {
 	if err != nil {
 		return HKExListener{nil}, err
 	}
-	fmt.Println("[Listening]")
+	log.Println("[Listening]")
 	hl.l = l
 	return
 }
@@ -250,7 +250,7 @@ func Listen(protocol string, ipport string) (hl HKExListener, e error) {
 //
 // See go doc io.Close
 func (hl HKExListener) Close() error {
-	fmt.Println("[Listener Closed]")
+	log.Println("[Listener Closed]")
 	return hl.l.Close()
 }
 
@@ -263,7 +263,7 @@ func (hl HKExListener) Accept() (hc Conn, err error) {
 		return Conn{c: nil, h: nil, cipheropts: 0, opts: 0,
 			r: nil, w: nil}, err
 	}
-	fmt.Println("[Accepted]")
+	log.Println("[Accepted]")
 
 	hc = Conn{c: c, h: New(0, 0), cipheropts: 0, opts: 0, op: 0, r: nil, w: nil}