fix func by passing conn, go fmt (oops), start http detection

chatserver.go

@@ -5,6 +5,7 @@ package main
 
 import (
 	"bufio"
+	"bytes"
 	"crypto/rand"
 	"encoding/base64"
 	"flag"
@@ -35,7 +36,6 @@ type ConfMailer struct {
 	From   string `yaml:"from,omitempty"`
 }
 
-
 type tcpUser struct {
 	bufConn   bufferedConn
 	userCount chan int
@@ -58,7 +58,7 @@ func (b bufferedConn) Peek(n int) ([]byte, error) {
 	return b.r.Peek(n)
 }
 
-func (b bufferedConn) Buffered() (int) {
+func (b bufferedConn) Buffered() int {
 	return b.r.Buffered()
 }
 
@@ -80,19 +80,22 @@ type myMsg struct {
 }
 
 var firstMsgs chan myMsg
+
 //var myRooms map[string](chan myMsg)
 var myMsgs chan myMsg
+
 //var myUnsortedConns map[net.Conn]bool
 var newConns chan net.Conn
 var newTcpChat chan bufferedConn
 var authTcpChat chan tcpUser
 var delTcpChat chan bufferedConn
 var newHttpChat chan bufferedConn
+var newHttpClient chan bufferedConn
 var delHttpChat chan bufferedConn
 
 func usage() {
 	fmt.Fprintf(os.Stderr, "\nusage: go run chatserver.go\n")
-  flag.PrintDefaults();
+	flag.PrintDefaults()
 	fmt.Println()
 
 	os.Exit(1)
@@ -124,7 +127,7 @@ func handleRaw(bufConn bufferedConn) {
 	// Handle all subsequent packets
 	buffer := make([]byte, 1024)
 	for {
-    //fmt.Fprintf(os.Stdout, "[raw] Waiting for message...\n");
+		//fmt.Fprintf(os.Stdout, "[raw] Waiting for message...\n")
 		count, err := bufConn.Read(buffer)
 		if nil != err {
 			if io.EOF != err {
@@ -172,13 +175,13 @@ func handleRaw(bufConn bufferedConn) {
 				var wg sync.WaitGroup
 				wg.Add(1)
 				go func() {
-          time.Sleep(50 * 1000000)
+					time.Sleep(50 * time.Millisecond)
 					const msg = "Mailing auth code..."
 					for _, r := range msg {
-            time.Sleep(20 * 1000000)
+						time.Sleep(20 * time.Millisecond)
 						fmt.Fprintf(bufConn, string(r))
 					}
-          time.Sleep(50 * 1000000)
+					time.Sleep(50 * time.Millisecond)
 					wg.Done()
 				}()
 				if "" != config.Mailer.ApiKey {
@@ -200,9 +203,9 @@ func handleRaw(bufConn bufferedConn) {
 				}
 				// so I don't have to actually go check my email
 				fmt.Fprintf(os.Stdout, "\n== AUTHORIZATION ==\n[cheat code for %s]: %s\n", email, code)
-        time.Sleep(150 * 1000000)
+				time.Sleep(150 * time.Millisecond)
 				fmt.Fprintf(bufConn, " done\n")
-        time.Sleep(150 * 1000000)
+				time.Sleep(150 * time.Millisecond)
 				fmt.Fprintf(bufConn, "Auth Code: ")
 				continue
 			}
@@ -211,7 +214,7 @@ func handleRaw(bufConn bufferedConn) {
 				fmt.Fprintf(bufConn, "Incorrect Code\nAuth Code: ")
 			} else {
 				authn = true
-        time.Sleep(150 * 1000000)
+				time.Sleep(150 * time.Millisecond)
 				fmt.Fprintf(bufConn, "\n")
 				u := tcpUser{
 					bufConn:   bufConn,
@@ -221,18 +224,18 @@ func handleRaw(bufConn bufferedConn) {
 				authTcpChat <- u
 				// prevent data race on len(myRawConns)
 				// XXX (there can't be a race between these two lines, right?)
-        count := <- u.userCount
+				count := <-u.userCount
 				u.userCount = nil
-        time.Sleep(50 * 1000000)
+				time.Sleep(50 * time.Millisecond)
 				fmt.Fprintf(bufConn, "\n")
-        time.Sleep(50 * 1000000)
+				time.Sleep(50 * time.Millisecond)
 				fmt.Fprintf(bufConn, "Welcome to #general (%d users)!", count)
-        time.Sleep(50 * 1000000)
+				time.Sleep(50 * time.Millisecond)
 				fmt.Fprintf(bufConn, "\n")
-        time.Sleep(50 * 1000000)
+				time.Sleep(50 * time.Millisecond)
 				// TODO /help /join <room> /users /channels /block <user> /upgrade <http/ws>
 				//fmt.Fprintf(bufConn, "(TODO `/help' for list of commands)")
-        time.Sleep(100 * 1000000)
+				time.Sleep(100 * time.Millisecond)
 				fmt.Fprintf(bufConn, "\n")
 
 				// this would be cool, but won't work since other messages will come
@@ -242,7 +245,7 @@ func handleRaw(bufConn bufferedConn) {
 			continue
 		}
 
-    //fmt.Fprintf(os.Stdout, "Queing message...\n");
+		//fmt.Fprintf(os.Stdout, "Queing message...\n")
 		//myRooms["general"] <- myMsg{
 		myMsgs <- myMsg{
 			receivedAt: time.Now(),
@@ -258,6 +261,7 @@ func handleRaw(bufConn bufferedConn) {
 func handleSorted(conn bufferedConn) {
 	// Wish List for protocol detection
 	// * PROXY protocol (and loop)
+	// * HTTP CONNECT (proxy) (and loop)
 	// * tls (and loop) https://github.com/polvi/sni
 	// * http/ws
 	// * irc
@@ -269,11 +273,50 @@ func handleSorted(conn bufferedConn) {
 	// Note: Realistically no tls/http/irc client is going to send so few bytes
 	//       (and no router is going to chunk so small)
 	//       that it cannot reasonably detect the protocol in the first packet
+	//       However, typical MTU is 1,500 and HTTP can have a 2k URL
+	//       so expecting to find the "HTTP/1.1" in the Peek is not always reasonable
 	n := conn.Buffered()
 	firstMsg, err := conn.Peek(n)
 	if nil != err {
-    panic(err)
+		conn.Close()
+		return
 	}
+	var protocol string
+	// between A and z
+	if firstMsg[0] >= 65 && firstMsg[0] <= 122 {
+		i := bytes.Index(firstMsg, []byte(" /"))
+		if -1 != i {
+			protocol = "HTTP"
+			// very likely HTTP
+			j := bytes.IndexAny(firstMsg, "\r\n")
+			if -1 != j {
+				k := bytes.Index(bytes.ToLower(firstMsg[:j]), []byte("HTTP/1"))
+				if -1 != k {
+					// positively HTTP
+				}
+			}
+		}
+	} else if 0x16 /*22*/ == firstMsg[0] {
+		// Because I don't always remember off the top of my head what the first byte is
+		// http://blog.fourthbit.com/2014/12/23/traffic-analysis-of-an-ssl-slash-tls-session
+		// https://tlseminar.github.io/first-few-milliseconds/
+		// TODO I want to learn about ALPN
+		protocol = "TLS"
+	}
+
+	if "" == protocol {
+		fmt.Fprintf(conn, "\n\nWelcome to Sample Chat! You're not an HTTP client, assuming Telnet.\nYou must authenticate via email to participate\n\nEmail: ")
+		newTcpChat <- conn
+		return
+	} else if "HTTP" != protocol {
+		defer conn.Close()
+		fmt.Fprintf(conn, "\n\nNot yet supported. Try HTTP or Telnet\n\n")
+		return
+	}
+
+	newHttpClient <- conn
+
+	/*
 	   firstMsgs <- myMsg{
 	     receivedAt: time.Now(),
 	     sender: conn,
@@ -289,7 +332,7 @@ func handleSorted(conn bufferedConn) {
 	   // Handle all subsequent packets
 	   buf := make([]byte, 1024)
 	   for {
-    fmt.Fprintf(os.Stdout, "[sortable] Waiting for message...\n");
+	     fmt.Fprintf(os.Stdout, "[sortable] Waiting for message...\n")
 	     count, err := conn.Read(buf)
 	     if nil != err {
 	       if io.EOF != err {
@@ -312,6 +355,7 @@ func handleSorted(conn bufferedConn) {
 	       channel: "general",
 	     }
 	   }
+	*/
 }
 
 func handleConnection(netConn net.Conn) {
@@ -337,15 +381,14 @@ func handleConnection(netConn net.Conn) {
 		}
 		//fmt.Fprintf(os.Stdout, "[First Byte] %s\n", fmsg)
 
-    m.Lock();
+		m.Lock()
 		if virgin {
 			virgin = false
 			newHttpChat <- bufConn
 		} else {
-      // TODO probably needs to go into a channel
 			newTcpChat <- bufConn
 		}
-    m.Unlock();
+		m.Unlock()
 	}()
 
 	time.Sleep(250 * 1000000)
@@ -378,7 +421,7 @@ func sendAuthCode(cnf ConfMailer, to string) (string, error) {
 	form := url.Values{}
 	form.Add("from", cnf.From)
 	form.Add("to", to)
-	form.Add("subject", "Sample Chat Auth Code: " + code)
+	form.Add("subject", "Sample Chat Auth Code: "+code)
 	form.Add("text", text)
 	form.Add("html", html)
 
@@ -414,6 +457,7 @@ func sendAuthCode(cnf ConfMailer, to string) (string, error) {
 }
 
 var config Conf
+
 func main() {
 	flag.Usage = usage
 	port := flag.Uint("telnet-port", 0, "tcp telnet chat port")
@@ -438,6 +482,7 @@ func main() {
 	authTcpChat = make(chan tcpUser, 128)
 	newTcpChat = make(chan bufferedConn, 128)
 	newHttpChat = make(chan bufferedConn, 128)
+	newHttpClient = make(chan bufferedConn, 128)
 	//myUnsortedConns = make(map[net.Conn]bool)
 
 	// TODO dynamically select on channels?
@@ -458,7 +503,7 @@ func main() {
 		fmt.Fprintf(os.Stderr, "Couldn't bind to TCP socket %q: %s\n", addr, err)
 		os.Exit(2)
 	}
-  fmt.Println("Listening on", addr);
+	fmt.Println("Listening on", addr)
 
 	go func() {
 		for {
@@ -471,14 +516,20 @@ func main() {
 			newConns <- conn
 		}
 	}()
+	/*
+	   server := &http.Server{
+	     Addr:    addr,
+	     Handler: &myHandler{},
+	   }
+	*/
 
 	// Main event loop handling most access to shared data
 	for {
 		select {
-    case conn := <- newConns:
+		case conn := <-newConns:
 			// This is short lived
 			go handleConnection(conn)
-    case u := <- authTcpChat:
+		case u := <-authTcpChat:
 			// allow to receive messages
 			// (and be counted among the users)
 			myRawConns[u.bufConn] = true
@@ -492,17 +543,19 @@ func main() {
 				channel:    "general",
 				email:      "system",
 			}
-    case bufConn := <- newTcpChat:
+		case bufConn := <-newTcpChat:
 			go handleRaw(bufConn)
-    case bufConn := <- delTcpChat:
+		case bufConn := <-delTcpChat:
 			// we can safely ignore this error
 			bufConn.Close()
 			delete(myRawConns, bufConn)
-    case bufConn := <- newHttpChat:
+		case bufConn := <-newHttpChat:
 			go handleSorted(bufConn)
 		//case msg := <- myRooms["general"]:
 		//delete(myRooms["general"], bufConn)
-    case msg := <- myMsgs:
+		//case bufConn := <-newHttpClient:
+		//server.Serve(bufConn)
+		case msg := <-myMsgs:
 			t := msg.receivedAt
 			tf := "%d-%02d-%02d %02d:%02d:%02d (%s)"
 			var sender string
@@ -516,7 +569,7 @@ func main() {
 			zone, _ := msg.receivedAt.Zone()
 
 			//ts, err := msg.receivedAt.MarshalJSON()
-      fmt.Fprintf(os.Stdout, tf + " [%s] (%s):\n\t%s",
+			fmt.Fprintf(os.Stdout, tf+" [%s] (%s):\n\t%s",
 				t.Year(), t.Month(), t.Day(),
 				t.Hour(), t.Minute(), t.Second(), zone,
 				sender,
@@ -528,23 +581,24 @@ func main() {
 					continue
 				}
 
+				// To ask: Why do I have to pass in conn to prevent a data race? Is it garbage collection?
 				// Don't block the rest of the loop
 				// TODO maybe use a chan to send to the socket's event loop
-        go func() {
+				go func(conn bufferedConn) {
 					// Protect against malicious clients to prevent DoS
 					// https://blog.cloudflare.com/the-complete-guide-to-golang-net-http-timeouts/
 					timeoutDuration := 5 * time.Second
 					conn.SetWriteDeadline(time.Now().Add(timeoutDuration))
-          _, err := fmt.Fprintf(conn, tf + " [%s]: %s",
+					_, err := fmt.Fprintf(conn, tf+" [%s]: %s",
 						t.Year(), t.Month(), t.Day(),
 						t.Hour(), t.Minute(), t.Second(), zone,
 						msg.email, msg.bytes)
 					if nil != err {
 						delTcpChat <- conn
 					}
-        }()
+				}(conn)
 			}
-    case msg := <- firstMsgs:
+		case msg := <-firstMsgs:
 			fmt.Fprintf(os.Stdout, "f [First Message]\n")
 			ts, err := msg.receivedAt.MarshalJSON()
 			if nil != err {
@@ -552,7 +606,7 @@ func main() {
 			}
 			fmt.Fprintf(os.Stdout, "f [Timestamp] %s\n", ts)
 			fmt.Fprintf(os.Stdout, "f [Remote] %s\n", msg.sender.RemoteAddr().String())
-      fmt.Fprintf(os.Stdout, "f [Message] %s\n", msg.bytes);
+			fmt.Fprintf(os.Stdout, "f [Message] %s\n", msg.bytes)
 		}
 	}
 }