From f03f4f9412e465006ac7e52944691f3406a880a7 Mon Sep 17 00:00:00 2001
From: Yveaux <info@emmission.nl>
Date: Fri, 4 Sep 2015 19:54:45 +0200
Subject: [PATCH] Hardened (dis)connections

Added support fot multiple sessions (Currently 5 max. Each connection
costs RAM!)
Each session can send data to the gateway. Data from the gateway will be
broadcasted to all connected clients.
Added serial logging of client (dis)connections. Inspect serial terminal
in case of problems.
---
 .../Esp8266Gateway/Esp8266Gateway.ino         | 147 +++++++++++-------
 .../examples/Esp8266Gateway/GatewayUtil.h     |   9 +-
 2 files changed, 100 insertions(+), 56 deletions(-)

diff --git a/libraries/MySensors/examples/Esp8266Gateway/Esp8266Gateway.ino b/libraries/MySensors/examples/Esp8266Gateway/Esp8266Gateway.ino
index c5be624ce1d..ee828b5ddb5 100644
--- a/libraries/MySensors/examples/Esp8266Gateway/Esp8266Gateway.ino
+++ b/libraries/MySensors/examples/Esp8266Gateway/Esp8266Gateway.ino
@@ -123,24 +123,34 @@ MySensor gw(transport, hw
   );
   
 
-#define IP_PORT 5003        // The port you want to open 
+#define IP_PORT 5003         // The port you want to open 
+#define MAX_SRV_CLIENTS 5    // how many clients should be able to telnet to this ESP8266
 
 // a R/W server on the port
-WiFiServer server(IP_PORT);
-// handle to open connection
-WiFiClient client;
-
-char inputString[MAX_RECEIVE_LENGTH] = "";    // A string to hold incoming commands from serial/ethernet interface
-int inputPos = 0;
-bool sentReady = false;
-
-void output(const char *fmt, ... ) {
-   va_list args;
-   va_start (args, fmt );
-   vsnprintf_P(serialBuffer, MAX_SEND_LENGTH, fmt, args);
-   va_end (args);
-   Serial.print(serialBuffer);
-   server.write(serialBuffer);
+static WiFiServer server(IP_PORT);
+static WiFiClient clients[MAX_SRV_CLIENTS];
+static bool clientsConnected[MAX_SRV_CLIENTS];
+static inputBuffer inputString[MAX_SRV_CLIENTS];
+
+#define ARRAY_SIZE(x)  (sizeof(x)/sizeof(x[0]))
+
+
+void output(const char *fmt, ... )
+{
+  char serialBuffer[MAX_SEND_LENGTH];
+  va_list args;
+  va_start (args, fmt );
+  vsnprintf_P(serialBuffer, MAX_SEND_LENGTH, fmt, args);
+  va_end (args);
+  Serial.print(serialBuffer);
+  for (uint8_t i = 0; i < ARRAY_SIZE(clients); i++)
+  {
+    if (clients[i] && clients[i].connected())
+    {
+//       Serial.print("Client "); Serial.print(i); Serial.println(" write");
+       clients[i].write((uint8_t*)serialBuffer, strlen(serialBuffer));
+    }
+  }
 }
 
 void setup()  
@@ -153,7 +163,8 @@ void setup()
   Serial.print("Connecting to "); Serial.println(ssid);
 
   (void)WiFi.begin(ssid, pass);
-  while (WiFi.status() != WL_CONNECTED) {
+  while (WiFi.status() != WL_CONNECTED)
+  {
     delay(500);
     Serial.print(".");
   }
@@ -168,6 +179,7 @@ void setup()
   
   // start listening for clients
   server.begin();
+  server.setNoDelay(true);  
 }
 
 
@@ -176,47 +188,74 @@ void loop() {
   
   checkButtonTriggeredInclusion();
   checkInclusionFinished();
-  
-  //check if there are any new clients
-  if (server.hasClient())
+
+  // Go over list of clients and stop any that are no longer connected.
+  // If the server has a new client connection it will be assigned to a free slot.
+  bool allSlotsOccupied = true;
+  for (uint8_t i = 0; i < ARRAY_SIZE(clients); i++)
   {
-    if (client)
+    if (!clients[i].connected())
     {
-      client.stop();
+      if (clientsConnected[i])
+      {
+        Serial.print("Client "); Serial.print(i); Serial.println(" disconnected");
+        clients[i].stop();
+      }
+      //check if there are any new clients
+      if (server.hasClient())
+      {
+        clients[i] = server.available();
+        inputString[i].idx = 0;
+        Serial.print("Client "); Serial.print(i); Serial.println(" connected"); 
+        output(PSTR("0;0;%d;0;%d;Gateway startup complete.\n"),  C_INTERNAL, I_GATEWAY_READY);
+      }
     }
-    client = server.available();
-    output(PSTR("0;0;%d;0;%d;Gateway startup complete.\n"),  C_INTERNAL, I_GATEWAY_READY);
-  }     		 
-
-  if (client) {
-     if (!client.connected()) {
-       client.stop();
-     } else if (client.available()) { 
-       // read the bytes incoming from the client
-       char inChar = client.read();
-       if (inputPos<MAX_RECEIVE_LENGTH-1) { 
-         // if newline then command is complete
-         if (inChar == '\n') {  
-           Serial.println("Finished");
-            // a command was issued by the client
-            // we will now try to send it to the actuator
-            inputString[inputPos] = 0;
-      
-            // echo the string to the serial port
-            Serial.print(inputString);
-      
-            parseAndSend(gw, inputString);
-      
-            // clear the string:
-            inputPos = 0;
-         } else {  
-           // add it to the inputString:
-           inputString[inputPos] = inChar;
-           inputPos++;
-         }
+    bool connected = clients[i].connected();
+    clientsConnected[i] = connected;
+    allSlotsOccupied &= connected;
+  }
+  if (allSlotsOccupied && server.hasClient())
+  {
+    //no free/disconnected spot so reject
+    Serial.println("No free slot available");
+    WiFiClient c = server.available();
+    c.stop();
+  }
+  
+  // Loop over clients connect and read available data
+  for (uint8_t i = 0; i < ARRAY_SIZE(clients); i++)
+  {
+    while(clients[i].connected() && clients[i].available())
+    {
+      char inChar = clients[i].read();
+      if ( inputString[i].idx < MAX_RECEIVE_LENGTH - 1 )
+      { 
+        // if newline then command is complete
+        if (inChar == '\n')
+        {  
+          // a command was issued by the client
+          // we will now try to send it to the actuator
+          inputString[i].string[inputString[i].idx] = 0;
+    
+          // echo the string to the serial port
+          Serial.print("Client "); Serial.print(i); Serial.print(": "); Serial.println(inputString[i].string);
+    
+          parseAndSend(gw, inputString[i].string);
+    
+          // clear the string:
+          inputString[i].idx = 0;
+          // Finished with this client's message. Next loop() we'll see if there's more to read.
+          break;
+        } else {  
+         // add it to the inputString:
+         inputString[i].string[inputString[i].idx++] = inChar;
+        }
       } else {
-         // Incoming message too long. Throw away 
-         inputPos = 0;
+        // Incoming message too long. Throw away 
+        Serial.print("Client "); Serial.print(i); Serial.println(": Message too long");
+        inputString[i].idx = 0;
+        // Finished with this client's message. Next loop() we'll see if there's more to read.
+        break;
       }
     }
   }
diff --git a/libraries/MySensors/examples/Esp8266Gateway/GatewayUtil.h b/libraries/MySensors/examples/Esp8266Gateway/GatewayUtil.h
index c926f5e1686..fa814b3b8a7 100644
--- a/libraries/MySensors/examples/Esp8266Gateway/GatewayUtil.h
+++ b/libraries/MySensors/examples/Esp8266Gateway/GatewayUtil.h
@@ -3,13 +3,19 @@
 
 #ifdef ARDUINO
 
-
 static uint8_t inclusionTime = 1; // Number of minutes inclusion mode is enabled
 static uint8_t pinInclusion =  3; // Input pin that should trigger inclusion mode
 
 #define MAX_RECEIVE_LENGTH 100 // Max buffersize needed for messages coming from controller
 #define MAX_SEND_LENGTH 120 // Max buffersize needed for messages destined for controller
 
+
+typedef struct
+{
+  char    string[MAX_RECEIVE_LENGTH];
+  uint8_t idx;
+} inputBuffer;
+
 static volatile boolean buttonTriggeredInclusion;
 static boolean inclusionMode; // Keeps track on inclusion mode
 bool inclusionButtonSupported = false;
@@ -20,7 +26,6 @@ MyParserSerial parser;
 void setInclusionMode(boolean newMode);
 
 char convBuf[MAX_PAYLOAD*2+1];
-char serialBuffer[MAX_SEND_LENGTH]; // Buffer for building string when sending data to vera
 unsigned long inclusionStartTime;