CLI support (#59)

chat.go

@@ -2,6 +2,7 @@ package proxy
 
 import (
 	"fmt"
+	"io"
 	"strings"
 	"time"
 
@@ -59,8 +60,41 @@ func onChatMsg(cc *ClientConn, cmd *mt.ToSrvChatMsg) (string, bool) {
 			return fmt.Sprintf("Missing permission %s.", cmd.Perm), true
 		}
 
-		return cmd.Handler(cc, args...), true
+		return cmd.Handler(cc, nil, args...), true
 	}
 
 	return "", false
 }
+
+func onTelnetMsg(tlog func(dir string, v ...interface{}), w io.Writer, msg string) string {
+	initChatCmds()
+
+	substrs := strings.Split(msg, " ")
+	cmdName := substrs[0]
+
+	var args []string
+	if len(substrs) > 1 {
+		args = substrs[1:]
+	}
+
+	v := make([]interface{}, 2+len(args))
+	v[0] = "command"
+	v[1] = cmdName
+
+	for i, arg := range args {
+		v[i+2] = arg
+	}
+
+	tlog("-->", v...)
+
+	if !ChatCmdExists(cmdName) {
+		tlog("<--", "unknown command", cmdName)
+		return "Command not found.\n"
+	}
+
+	chatCmdsMu.RLock()
+	defer chatCmdsMu.RUnlock()
+
+	cmd := chatCmds[cmdName]
+	return cmd.Handler(nil, w, args...) + "\n"
+}

config.go

@@ -12,7 +12,7 @@ const defaultCmdPrefix = ">"
 const defaultSendInterval = 0.09
 const defaultUserLimit = 10
 const defaultAuthBackend = "sqlite3"
-const defaultTelnetAddr = ":40010"
+const defaultTelnetAddr = "[::1]:40010"
 const defaultBindAddr = ":40000"
 const defaultListInterval = 300
 

plugin_chatcmd.go

@@ -1,6 +1,9 @@
 package proxy
 
-import "sync"
+import (
+	"io"
+	"sync"
+)
 
 // A ChatCmd holds information on how to handle a chat command.
 type ChatCmd struct {
@@ -8,7 +11,7 @@ type ChatCmd struct {
 	Perm    string
 	Help    string
 	Usage   string
-	Handler func(*ClientConn, ...string) string
+	Handler func(*ClientConn, io.Writer, ...string) string
 }
 
 var chatCmds map[string]ChatCmd

telnet.go

@@ -5,9 +5,24 @@ import (
 	"errors"
 	"io"
 	"log"
+	"math"
 	"net"
+	"strings"
 )
 
+// A TelnetWriter can be used to print something at the other end
+// of a telnet connection. It implements the io.Writer interface.
+type TelnetWriter struct {
+	conn net.Conn
+}
+
+// Write writes its parameter to the telnet connection.
+// A trailing newline is always appended.
+// It returns the number of bytes written and an error.
+func (tw *TelnetWriter) Write(p []byte) (n int, err error) {
+	return tw.conn.Write(append(p, '\n'))
+}
+
 var telnetCh = make(chan struct{})
 
 func telnetServer() error {
@@ -17,6 +32,8 @@ func telnetServer() error {
 	}
 	defer ln.Close()
 
+	log.Print("{←|⇶} listen telnet ", ln.Addr())
+
 	for {
 		select {
 		case <-telnetCh:
@@ -34,16 +51,39 @@ func telnetServer() error {
 }
 
 func handleTelnet(conn net.Conn) {
+	tlog := func(dir string, v ...interface{}) {
+		format := "{%s} %s {←|⇶}"
+		format += strings.Repeat(" %v", len(v))
+
+		log.Printf(format, append([]interface{}{
+			conn.RemoteAddr(),
+			dir,
+		}, v...)...)
+	}
+
+	tlog("<->", "telnet connect")
+
+	defer tlog("<->", "telnet disconnect")
 	defer conn.Close()
 
-	r, w := bufio.NewReader(conn), bufio.NewWriter(conn)
-	b := bufio.NewReadWriter(r, w)
+	readString := func(delim byte) (string, error) {
+		s, err := bufio.NewReader(conn).ReadString(delim)
+		i := int(math.Max(float64(len(s)-2), 1))
+		s = s[:i]
+		return s, err
+	}
+
+	writeString := func(s string) (n int, err error) {
+		return io.WriteString(conn, s)
+	}
+
+	writeString("mt-multiserver-proxy console\n")
+	writeString("Type \\quit or \\q to disconnect.\n")
 
-	b.WriteString("mt-multiserver-proxy console\n")
 	for {
-		b.WriteString(">")
+		writeString(Conf().CmdPrefix)
 
-		_, err := b.ReadString('\n')
+		s, err := readString('\n')
 		if err != nil {
 			if errors.Is(err, io.EOF) {
 				return
@@ -52,5 +92,16 @@ func handleTelnet(conn net.Conn) {
 			log.Print("{←|⇶} ", err)
 			continue
 		}
+
+		tlog("-->", "telnet command", s)
+
+		if s == "\\quit" || s == "\\q" {
+			return
+		}
+
+		result := onTelnetMsg(tlog, &TelnetWriter{conn: conn}, s)
+		if result != "" {
+			writeString(result)
+		}
 	}
 }