419 lines
11 KiB
Go
419 lines
11 KiB
Go
package main
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import (
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"bytes"
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"context"
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"errors"
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"flag"
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"io"
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"log"
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"net"
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"os"
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"os/exec"
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"strconv"
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"strings"
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"sync"
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"text/template"
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"time"
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"github.com/creack/pty"
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"github.com/xtaci/gaio"
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"golang.org/x/term"
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"versestudios.com/go-telnet-asyncio-test/openconn"
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)
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type InChanKey string
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type OutChanKey string
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func ioHandler(w *gaio.Watcher, WatcherControl *chan string) {
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for {
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select {
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case msg := <-*WatcherControl:
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switch msg {
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case "":
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log.Println("empty WatcherControl command")
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case "stop":
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log.Println("stopping ioHandler via WatcherControl stop command")
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return
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default:
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log.Println("unknown WatcherControl command:", msg)
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}
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default:
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// loop wait for any IO events
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results, err := w.WaitIO()
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if err != nil {
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log.Println(err)
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return
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}
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IOLoop:
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for _, res := range results {
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if res.Context != nil && nil != res.Context.(context.Context) {
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if inChan, _, ok := openconn.FromContext(res.Context.(context.Context)); ok {
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switch res.Operation {
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case gaio.OpRead: // read completion event
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inChan <- res
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// queue next read
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w.Read(res.Context, res.Conn, nil)
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default: // anything else (meaning write completions)
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continue IOLoop
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}
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} else {
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log.Printf("error getting inChan and outChan from context: %v\n", res.Context)
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}
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} else {
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log.Printf("nil context! res: %v\n", res)
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}
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}
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}
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time.Sleep(time.Millisecond)
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}
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}
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func main() {
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port := flag.Int("port", 3333, "Port to accept connections on.")
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host := flag.String("host", "127.0.0.1", "Host or IP to bind to")
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flag.Parse()
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w, err := gaio.NewWatcher()
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if err != nil {
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log.Fatal(err)
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}
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defer w.Close()
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l, err := net.Listen("tcp", *host+":"+strconv.Itoa(*port))
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if err != nil {
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log.Panicln(err)
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}
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log.Println("Listening to connections at '"+*host+"' on port", strconv.Itoa(*port))
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log.Println("(If you want to run this on a different address or port, the command line flags --host and --port are available to you.)")
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defer l.Close()
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for {
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conn, err := l.Accept()
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if err != nil {
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log.Panicln(err)
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}
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log.Println("new client: ", conn.RemoteAddr())
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// chan to terminate ioHandler when neccessary
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WatcherControl := make(chan string)
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// get new context with inChan and outChan for this client connection
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ctx := openconn.NewContext(context.Background())
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log.Printf("new context for client %v: %v\n", conn.RemoteAddr(), ctx)
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// submit the first async write IO request
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welcomeScreen, err := screenHandler("welcome")
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if err != nil {
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log.Printf("err loading initial welcome screen: %v\n", err)
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}
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err = w.Write(ctx, conn, welcomeScreen)
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if err != nil {
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log.Printf("err sending welcomeHandler: %v\n", err)
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return
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}
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// now that a prompt is (or will be) displayed, go ahead and listen for input
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err = w.Read(ctx, conn, nil)
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if err != nil {
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log.Printf("err queueing w.Read: %v\n", err)
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return
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}
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time.Sleep(time.Millisecond)
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// menu handler for this connection
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go menuHandler(ctx, conn, w)
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// io handler for this connection
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go ioHandler(w, &WatcherControl)
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log.Println("main thread looping")
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}
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}
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func menuHandler(ctx context.Context, conn net.Conn, w *gaio.Watcher) {
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var wg sync.WaitGroup
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MenuControl := make(chan string)
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var inChan, outChan chan gaio.OpResult
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var ok bool
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if inChan, outChan, ok = openconn.FromContext(ctx); !ok {
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log.Println("Could not get inChan/outChan from context!", ok, ctx)
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}
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wg.Add(1)
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go func(inChan, outChan chan gaio.OpResult, MenuControl chan string) {
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defer wg.Done()
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log.Println("starting menu loop")
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paused := false
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ControlLoop:
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for {
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select {
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case msg := <-MenuControl:
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log.Println("msg on MenuControl:", msg)
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switch string(msg) {
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case "stop":
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log.Println("closing menu loop")
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paused = true
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break ControlLoop
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case "pause":
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log.Println("pausing menu loop via menucontrol")
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paused = true
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case "unpause":
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log.Println("unpausing menu loop via menucontrol")
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paused = false
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default:
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log.Println("menu received unknown command: ", msg)
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}
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default:
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if !paused {
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select {
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case res := <-inChan:
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if res.Error != nil {
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log.Println("error on inChan: ", res.Error)
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}
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if res.Operation == gaio.OpRead && res.Size > 0 && res.Conn == conn {
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log.Printf("received on inChan: conn: %v, buffer size: %v\n", res.Conn.RemoteAddr(), res.Size)
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log.Println("menu receive: ", strings.TrimSpace(string(res.Buffer[:res.Size-2])))
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switch string(strings.TrimSpace(string(res.Buffer[:res.Size-2]))) {
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case "welcome":
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welcomeStr, err := screenHandler("welcome")
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if err != nil {
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log.Printf("err loading welcome screen: %v\n", err)
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}
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if err := w.Write(ctx, conn, welcomeStr); err != nil {
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log.Printf("error sending screenHandler from cmd `welcome`: %v", err)
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}
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case "help":
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helpStr, err := screenHandler("help")
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if err != nil {
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log.Printf("err loading help screen: %v\n", err)
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}
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if err := w.Write(ctx, conn, helpStr); err != nil {
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log.Printf("error sending screenHandler from cmd `help`: %v", err)
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}
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case "operator":
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opStr, err := screenHandler("operator")
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if err != nil {
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log.Printf("err loading operator screen: %v\n", err)
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}
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var lineNum int
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var line string
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baudrate := 40 // 300 baud is ~ 30 characters per second; I'll be nice and bump it to 400
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for lineNum, line = range strings.Split(string(opStr), "\n") {
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// changed my mind - I actually like it at a nice steady 400 baud, tyvm
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// if baudrate < 120 && i > 1 { // 1200 baud is still very readable in realtime without being too fast
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// baudrate += 1
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//}
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if lineNum < 10 { // spit the banner text out quickly
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if err := w.Write(ctx, conn, []byte(line+"\r\n")); err != nil {
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log.Printf("error sending rune from cmd `operator`: %v", err)
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}
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} else {
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ms := float64(1) / float64(baudrate)
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for _, c := range line {
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if err := w.Write(ctx, conn, []byte{byte(c)}); err != nil {
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log.Printf("error sending rune from cmd `operator`: %v", err)
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}
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time.Sleep(time.Duration(ms*1000) * time.Millisecond)
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}
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if err := w.Write(ctx, conn, []byte("\r\n")); err != nil {
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log.Printf("error sending rune from cmd `operator`: %v", err)
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}
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}
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}
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// add prompt at end
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if err := w.Write(ctx, conn, []byte("\r\n> ")); err != nil {
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log.Printf("error sending rune from cmd `operator`: %v", err)
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}
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case "adventure":
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// start the door and wait
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var wg sync.WaitGroup
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log.Println("starting door handler...")
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wg.Add(1)
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go doorHandler(ctx, conn, w, &wg)
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log.Println("menu handler waiting for wg to return from door")
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wg.Wait()
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log.Println("returning from door")
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// welcome back and prompt
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err := w.Write(ctx, conn, []byte("Welcome back from your adventure!\n\n> "))
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if err != nil {
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log.Printf("error writing to connection: %v", err)
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}
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case "exit":
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exitStr, err := screenHandler("exit")
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if err != nil {
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log.Printf("err loading exit screen: %v\n", err)
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}
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if err := w.Write(ctx, conn, exitStr); err != nil {
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log.Printf("error sending exitHandler from cmd `exit`: %v", err)
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}
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// wait a second before really closing the connection
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time.Sleep(time.Second)
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w.Free(conn)
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default:
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err := w.Write(ctx, conn, []byte("huh?\n\n> "))
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if err != nil {
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log.Printf("error writing to connection: %v", err)
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}
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}
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} else {
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// noop
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log.Printf("received on inChan: conn: %v, buffer: %v\n", res.Conn.RemoteAddr(), string(res.Buffer))
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}
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default:
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// noop - wait a lil bit
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time.Sleep(time.Millisecond)
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}
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if conn == nil {
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log.Println("conn is nil!")
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}
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}
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}
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time.Sleep(time.Millisecond)
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}
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log.Println("menu controlloop closed!")
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}(inChan, outChan, MenuControl)
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log.Println("menu waiting on waitgroup")
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wg.Wait()
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log.Println("terminating menucontrol for client")
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}
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func screenHandler(screenName string) (screen []byte, err error) {
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var screenBuf *bytes.Buffer
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if tmpl, err := template.ParseFiles("screens/" + screenName + ".ans"); err != nil {
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log.Printf("err loading welcome template: %v\n", err)
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} else {
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screenBuf = new(bytes.Buffer)
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tmpl.Execute(screenBuf, nil)
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}
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return screenBuf.Bytes(), err
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}
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func doorHandler(ctx context.Context, c net.Conn, w *gaio.Watcher, menuwg *sync.WaitGroup) error {
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defer menuwg.Done()
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var wg sync.WaitGroup
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var inChan, _ chan gaio.OpResult
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var ok bool
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if inChan, _, ok = openconn.FromContext(ctx); !ok {
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log.Println("Could not get inChan/outChan from context!", ok, ctx)
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}
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cmd := exec.Command("/usr/games/adventure")
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ptmx, err := pty.Start(cmd)
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if err != nil {
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return err
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}
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// Make sure to close the pty at the end.
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defer func() { _ = ptmx.Close() }() // Best effort.
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// Can I do this?
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if term.IsTerminal(int(ptmx.Fd())) {
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log.Println("Making cmd terminal raw")
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oldState, _ := term.MakeRaw(int(ptmx.Fd()))
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defer term.Restore(int(ptmx.Fd()), oldState)
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}
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Terminator := make(chan bool)
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wg.Add(1)
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go func() {
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defer wg.Done()
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waitingForInput := false
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IOLoop:
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for {
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select {
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case result, ok := <-inChan:
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var l int
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log.Println("i")
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if ok {
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if result.Operation == gaio.OpRead && result.Size > 0 {
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l, err = ptmx.Write(result.Buffer[:result.Size])
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if err != nil {
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if err == io.EOF {
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log.Println("EOF on cmd.write!!!")
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break IOLoop
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}
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}
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if l > 0 {
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log.Printf("wrote %d bytes to cmd stdin: %v\n", l, string(result.Buffer[:result.Size]))
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waitingForInput = false
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}
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}
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} else {
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log.Println("yikes, problem getting a result from inChan in doorHandler!")
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}
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case <-Terminator:
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log.Println("Terminator'd!!!")
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break IOLoop
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default:
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if !waitingForInput {
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log.Println("o")
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ptmx.SetReadDeadline(time.Now().Add(1 * time.Second))
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var l int
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outBuf := make([]byte, 4096)
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if l, err = ptmx.Read(outBuf); err != nil {
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if err == io.EOF {
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log.Println("EOF on cmd stdout - outta here")
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break IOLoop
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} else if errors.Is(err, os.ErrDeadlineExceeded) {
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// output deadline exceeded - get some input instead
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w.Read(ctx, c, nil)
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waitingForInput = true
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} else if errors.Is(err, os.ErrClosed) {
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// program exited - get outta here
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break IOLoop
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} else {
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log.Printf("err reading from cmd term: %v\n", err)
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break IOLoop
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}
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}
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if l > 0 {
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w.Write(ctx, c, outBuf[:l])
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log.Printf("wrote %d bytes to watcher: %v\n", l, string(outBuf[:l]))
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if strings.Contains(string(outBuf[:l]), ">") {
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// a prompt appeared!
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waitingForInput = true
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}
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} else {
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// zero output? let's get some input?
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// waitingForInput = true
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w.Read(ctx, c, nil)
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}
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}
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}
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time.Sleep(time.Millisecond)
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}
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}()
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wg.Wait()
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log.Println("waiting for cmd")
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exitErr := cmd.Wait()
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if exitErr != nil {
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log.Printf("cmd exited with err: %v\n", exitErr)
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}
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log.Println("leaving door handler")
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return nil
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}
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