mostly just cleanup I think...

chatserver.go

@@ -36,6 +36,12 @@ type ConfMailer struct {
 }
 
 
+type tcpUser struct {
+  bufConn bufferedConn
+  userCount chan int
+  email string
+}
+
 // So we can peek at net.Conn, which we can't do natively
 // https://stackoverflow.com/questions/51472020/how-to-get-the-size-of-available-tcp-data
 type bufferedConn struct {
@@ -70,15 +76,16 @@ type myMsg struct {
   bytes []byte
   receivedAt time.Time
   channel string
+  email string
 }
 
 var firstMsgs chan myMsg
-var myChans map[string](chan myMsg)
+//var myRooms map[string](chan myMsg)
 var myMsgs chan myMsg
-var myUnsortedConns map[net.Conn]bool
+//var myUnsortedConns map[net.Conn]bool
-var myRawConns 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 delHttpChat chan bufferedConn
@@ -117,7 +124,7 @@ 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 {
@@ -125,7 +132,6 @@ func handleRaw(bufConn bufferedConn) {
       }
       fmt.Fprintf(os.Stdout, "Ending socket\n")
 
-      // TODO put this in a channel to prevent data races
       delTcpChat <- bufConn
       break
     }
@@ -140,7 +146,9 @@ func handleRaw(bufConn bufferedConn) {
 
     if !authn {
       if "" == email {
-        fmt.Fprintf(os.Stdout, "buf{%s}\n", buf[:count])
+        // Indeed telnet sends CRLF as part of the message
+        //fmt.Fprintf(os.Stdout, "buf{%s}\n", buf[:count])
+
         // TODO use safer email testing
         email = strings.TrimSpace(string(buf[:count]))
         emailParts := strings.Split(email, "@")
@@ -148,12 +156,53 @@ func handleRaw(bufConn bufferedConn) {
           fmt.Fprintf(bufConn, "Email: ")
           continue
         }
-        fmt.Fprintf(os.Stdout, "email: '%v'\n", []byte(email))
+
+        // Debugging any weird characters as part of the message (just CRLF)
+        //fmt.Fprintf(os.Stdout, "email: '%v'\n", []byte(email))
+
+        // Just for a fun little bit of puzzah
+        // Note: Reaction times are about 100ms
+        //       Procesing times are about 250ms
+        //       Right around 300ms is about when a person literally begins to get bored (begin context switching)
+        //       Therefore any interaction should take longer than 100ms (time to register)
+        //       and either engage the user or complete before reaching 300ms (not yet bored)
+        //       This little ditty is meant to act as a psuedo-progress bar to engage the user
+        //       Aside: a keystroke typically takes >=50s to type (probably closer to 200ms between words)
+        //       https://stackoverflow.com/questions/22505698/what-is-a-typical-keypress-duration
+        var wg sync.WaitGroup
+        wg.Add(1)
+        go func() {
+          time.Sleep(50 * 1000000)
+          const msg = "Mailing auth code..."
+          for _, r := range msg {
+            time.Sleep(20 * 1000000)
+            fmt.Fprintf(bufConn, string(r))
+          }
+          time.Sleep(50 * 1000000)
+          wg.Done()
+        }()
+        if "" != config.Mailer.ApiKey {
+          wg.Add(1)
+          go func() {
             code, err = sendAuthCode(config.Mailer, strings.TrimSpace(email))
+            wg.Done()
+          }()
+        } else {
+          code, err = genAuthCode()
+        }
+        wg.Wait()
         if nil != err {
           // TODO handle better
+          // (not sure why a random number would fail,
+          //  but on a machine without internet the calls
+          //  to mailgun APIs would fail)
           panic(err)
         }
+        // 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)
+        fmt.Fprintf(bufConn, " done\n")
+        time.Sleep(150 * 1000000)
         fmt.Fprintf(bufConn, "Auth Code: ")
         continue
       }
@@ -162,27 +211,64 @@ func handleRaw(bufConn bufferedConn) {
         fmt.Fprintf(bufConn, "Incorrect Code\nAuth Code: ")
       } else {
         authn = true
-        fmt.Fprintf(bufConn, "Welcome to #general! (TODO `/help' for list of commands)\n")
+        time.Sleep(150 * 1000000)
-        // TODO number of users
+        fmt.Fprintf(bufConn, "\n")
-        //fmt.Fprintf(bufConn, "Welcome to #general! TODO `/list' to see channels. `/join chname' to switch.\n")
+        u := tcpUser{
+          bufConn: bufConn,
+          email: email,
+          userCount: make(chan int, 1),
+        }
+        authTcpChat <- u
+        // prevent data race on len(myRawConns)
+        // XXX (there can't be a race between these two lines, right?)
+        count := <- u.userCount
+        u.userCount = nil
+        time.Sleep(50 * 1000000)
+        fmt.Fprintf(bufConn, "\n")
+        time.Sleep(50 * 1000000)
+        fmt.Fprintf(bufConn, "Welcome to #general (%d users)!", count)
+        time.Sleep(50 * 1000000)
+        fmt.Fprintf(bufConn, "\n")
+        time.Sleep(50 * 1000000)
+        // TODO /help /join <room> /users /channels /block <user> /upgrade <http/ws>
+        //fmt.Fprintf(bufConn, "(TODO `/help' for list of commands)")
+        time.Sleep(100 * 1000000)
+        fmt.Fprintf(bufConn, "\n")
+
+        // this would be cool, but won't work since other messages will come
+        // in before the person responds
+        //fmt.Fprintf(bufConn, "\n%s> ", email)
       }
       continue
     }
 
-    fmt.Fprintf(os.Stdout, "Queing message...\n");
+    //fmt.Fprintf(os.Stdout, "Queing message...\n");
-    //myChans["general"] <- myMsg{
+    //myRooms["general"] <- myMsg{
     myMsgs <- myMsg{
       receivedAt: time.Now(),
       sender: bufConn,
       bytes: buf[0:count],
       channel: "general",
+      email: email,
     }
+    //fmt.Fprintf(bufConn, "> ")
   }
 }
 
 func handleSorted(conn bufferedConn) {
-  // at this piont we've already at least one byte via Peek()
+  // Wish List for protocol detection
+  // * PROXY protocol (and loop)
+  // * tls (and loop) https://github.com/polvi/sni
+  // * http/ws
+  // * irc
+  // * fallback to telnet
+
+  // At this piont we've already at least one byte via Peek()
   // so the first packet is available in the buffer
+
+  // 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
   n := conn.Buffered()
   firstMsg, err := conn.Peek(n)
   if nil != err {
@@ -218,7 +304,7 @@ func handleSorted(conn bufferedConn) {
       // fmt.Fprintf(os.Stdout, "Weird")
       continue
     }
-    //myChans["general"] <- myMsg{
+    //myRooms["general"] <- myMsg{
     myMsgs <- myMsg{
       receivedAt: time.Now(),
       sender: conn,
@@ -228,9 +314,9 @@ func handleSorted(conn bufferedConn) {
   }
 }
 
-// TODO https://github.com/polvi/sni
 func handleConnection(netConn net.Conn) {
-  fmt.Fprintf(os.Stdout, "Accepting socket\n")
+  ts := time.Now()
+  fmt.Fprintf(os.Stdout, "[New Connection] (%s) welcome %s\n", ts, netConn.RemoteAddr().String())
 
   m := sync.Mutex{}
   virgin := true
@@ -241,14 +327,15 @@ func handleConnection(netConn net.Conn) {
   // But this does
 
 	bufConn := newBufferedConn(netConn)
-  myUnsortedConns[bufConn] = true
+  //myUnsortedConns[bufConn] = true
   go func() {
     // Handle First Packet
-    fmsg, err := bufConn.Peek(1)
+    _, err := bufConn.Peek(1)
+    //fmsg, err := bufConn.Peek(1)
     if nil != err {
       panic(err)
     }
-    fmt.Fprintf(os.Stdout, "[First Byte] %s\n", fmsg)
+    //fmt.Fprintf(os.Stdout, "[First Byte] %s\n", fmsg)
 
     m.Lock();
     if virgin {
@@ -269,7 +356,7 @@ func handleConnection(netConn net.Conn) {
     virgin = false
     // don't block for this
     // let it be handled after the unlock
-    defer fmt.Fprintf(netConn, "Welcome to Sample Chat! You appear to be using Telnet.\nYou must authenticate via email to participate\nEmail: ")
+    defer fmt.Fprintf(netConn, "\n\nWelcome to Sample Chat! You appear to be using Telnet.\nYou must authenticate via email to participate\n\nEmail: ")
   }
   m.Unlock()
 }
@@ -310,11 +397,18 @@ func sendAuthCode(cnf ConfMailer, to string) (string, error) {
   }
 
   defer resp.Body.Close()
+  // Security XXX
+  // we trust mailgun implicitly and this is just a demo
+  // hence no DoS check on body size for now
   body, err := ioutil.ReadAll(resp.Body)
   if nil != err {
     return "", err
   }
-  fmt.Fprintf(os.Stdout, "Here's what Mailgun had to say about the event: %s\n", body)
+  if resp.StatusCode < 200 || resp.StatusCode >= 300 || "{" != string(body[0]) {
+    fmt.Fprintf(os.Stdout, "[Mailgun] Uh-oh...\n[Maigun] Baby Brent says: %s\n", body)
+  } else {
+    fmt.Fprintf(os.Stdout, "[Mailgun] Status: %d", resp.StatusCode)
+  }
 
   return code, nil
 }
@@ -337,17 +431,18 @@ func main() {
     config = Conf{}
   }
 
+  myRawConns := make(map[bufferedConn]bool)
   firstMsgs = make(chan myMsg, 128)
-  myChans = make(map[string](chan myMsg))
+  //myRooms = make(map[string](chan myMsg))
   newConns = make(chan net.Conn, 128)
+  authTcpChat = make(chan tcpUser, 128)
   newTcpChat = make(chan bufferedConn, 128)
   newHttpChat = make(chan bufferedConn, 128)
-  myRawConns = make(map[net.Conn]bool)
+  //myUnsortedConns = make(map[net.Conn]bool)
-  myUnsortedConns = make(map[net.Conn]bool)
 
   // TODO dynamically select on channels?
   // https://stackoverflow.com/questions/19992334/how-to-listen-to-n-channels-dynamic-select-statement
-  //myChans["general"] = make(chan myMsg, 128)
+  //myRooms["general"] = make(chan myMsg, 128)
   myMsgs = make(chan myMsg, 128)
 
   var addr string
@@ -377,40 +472,77 @@ func main() {
     }
   }()
 
+  // Main event loop handling most access to shared data
   for {
     select {
     case conn := <- newConns:
-      ts := time.Now()
-      fmt.Fprintf(os.Stdout, "[Handle New Connection] [Timestamp] %s\n", ts)
       // This is short lived
       go handleConnection(conn)
+    case u := <- authTcpChat:
+      // allow to receive messages
+      // (and be counted among the users)
+      myRawConns[u.bufConn] = true
+      // is chan chan the right way to handle this?
+      u.userCount <- len(myRawConns)
+      myMsgs <- myMsg{
+        sender: nil,
+        // TODO fmt.Fprintf()? template?
+        bytes: []byte("<" + u.email + "> joined #general\n"),
+        receivedAt: time.Now(),
+        channel: "general",
+        email: "system",
+      }
     case bufConn := <- newTcpChat:
-      myRawConns[bufConn] = true
       go handleRaw(bufConn)
     case bufConn := <- delTcpChat:
-      bufConn.Close();
+      // we can safely ignore this error
+      bufConn.Close()
       delete(myRawConns, bufConn)
     case bufConn := <- newHttpChat:
       go handleSorted(bufConn)
-    //case msg := <- myChans["general"]:
+    //case msg := <- myRooms["general"]:
-      //delete(myChans["general"], bufConn)
+      //delete(myRooms["general"], bufConn)
     case msg := <- myMsgs:
-      ts, err := msg.receivedAt.MarshalJSON()
+      t := msg.receivedAt
-      if nil != err {
+      tf := "%d-%02d-%02d %02d:%02d:%02d (%s)"
-        fmt.Fprintf(os.Stderr, "[Error] %s\n", err)
+      var sender string
+      if nil != msg.sender {
+        sender = msg.sender.RemoteAddr().String()
+      } else {
+        sender = "system"
       }
-      fmt.Fprintf(os.Stdout, "[Timestamp] %s\n", ts)
+      // I wonder if we could use IP detection to get the client's tz
-      fmt.Fprintf(os.Stdout, "[Remote] %s\n", msg.sender.RemoteAddr().String())
+      // ... could probably make time for this in the authentication loop
-      fmt.Fprintf(os.Stdout, "[Message] %s\n", msg.bytes);
+      zone, _ := msg.receivedAt.Zone()
+
+      //ts, err := msg.receivedAt.MarshalJSON()
+      fmt.Fprintf(os.Stdout, tf + " [%s] (%s):\n\t%s",
+        t.Year(), t.Month(), t.Day(),
+        t.Hour(), t.Minute(), t.Second(), zone,
+        sender,
+        msg.email, msg.bytes)
+
       for conn, _ := range myRawConns {
+        // Don't echo back to the original client
         if msg.sender == conn {
           continue
         }
-        // backlogged connections could prevent a next write,
+
-        // so this should be refactored into a goroutine
+        // Don't block the rest of the loop
-        // And what to do about slow clients that get behind (or DoS)?
+        // TODO maybe use a chan to send to the socket's event loop
-        // SetDeadTime and Disconnect them?
+        go func() {
-        conn.Write(msg.bytes)
+          // 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",
+            t.Year(), t.Month(), t.Day(),
+            t.Hour(), t.Minute(), t.Second(), zone,
+            msg.email, msg.bytes)
+          if nil != err {
+            delTcpChat <- conn
+          }
+        }()
       }
     case msg := <- firstMsgs:
       fmt.Fprintf(os.Stdout, "f [First Message]\n")