Fix connection issues (nRF24#33)

* Fix for connection issues
   - Found an issue where a connection is made but no data is sent. The connection can be left open indefinitely unless there is a timeout of sorts.

* Amend applicable examples

* Alter data struct
   - Put the boolean last in the data struct for memory alignment purposes

RF24Client.cpp

@@ -240,6 +240,13 @@ void serialip_appcall(void)
 {
     uip_userdata_t *u = (uip_userdata_t *)uip_conn->appstate;
 
+    if(u && u->connectTimeout > 0){
+      if(millis() - u->connectTimer > u->connectTimeout && u->initialData == false){
+        uip_close();
+        IF_RF24ETHERNET_DEBUG_CLIENT(Serial.println(); Serial.print(millis()); Serial.println("UIP Client close(timeout)"););
+      }
+    }
+
     /*******Connected**********/
     if (!u && uip_connected())
     {
@@ -265,6 +272,8 @@ void serialip_appcall(void)
         {
             IF_RF24ETHERNET_DEBUG_CLIENT(Serial.println(); Serial.print(millis()); Serial.print(F(" UIPClient uip_newdata, uip_len:")); Serial.println(uip_len););
 
+            u->initialData = true;
+
             if (u->sent)
             {
                 u->hold = (u->out_pos = (u->windowOpened = (u->packets_out = false)));
@@ -428,6 +437,8 @@ uip_userdata_t *RF24Client::_allocateData()
             data->dataPos = 0;
             data->out_pos = 0;
             data->hold = 0;
+            data->initialData = false;
+            data->connectTimer = millis();
             return data;
         }
     }

RF24Client.h

@@ -66,7 +66,10 @@ typedef struct {
     uint32_t restartTime;
     uint32_t restartInterval;
     uint32_t connAbortTime;
+    uint32_t connectTimeout;
+    uint32_t connectTimer;
     uint8_t myData[OUTPUT_BUFFER_SIZE];
+    bool initialData;
 } uip_userdata_t;
 
 

RF24Server.cpp

@@ -82,3 +82,13 @@ size_t RF24Server::write(const uint8_t *buf, size_t size)
     }
     return ret;
 }
+
+void RF24Server::setTimeout(uint32_t timeout)
+{
+    for(uint8_t i = 0; i < UIP_CONNS; i++){
+        uip_userdata_t *data = &RF24Client::all_data[i];
+        if(data){
+            data->connectTimeout = timeout;
+        }
+    }
+}

RF24Server.h

@@ -35,6 +35,7 @@ class RF24Server : public Server {
     size_t write(uint8_t);
     size_t write(const uint8_t *buf, size_t size);
     using Print::write;
+    void setTimeout(uint32_t timeout);
 
 private:
     uint16_t _port;

examples/Getting_Started_SimpleServer_Mesh/Getting_Started_SimpleServer_Mesh.ino

@@ -119,6 +119,10 @@ void setup() {
   // Listen for incoming connections on TCP port 1000.  Each incoming
   // connection will result in the uip_callback() function being called.
   server.begin();
+
+  // If no data is received from an incoming connection in the first 30 seconds,
+  // close the connection
+  server.setTimeout(30000);
 }
 
 uint32_t mesh_timer = 0;

examples/InteractiveServer_Mesh/InteractiveServer_Mesh.ino

@@ -62,6 +62,7 @@ void setup() {
   Ethernet.set_gateway(gwIP);
 
   server.begin();
+  server.setTimeout(30000);
 
 }
 

examples/InteractiveServer_Mesh_ESPWifi/InteractiveServer_Mesh_ESPWifi.ino

@@ -60,6 +60,7 @@ void setup() {
   Ethernet.set_gateway(gwIP);
 
   server.begin();
+  server.setTimeout(30000);
   // prepare GPIO2
   pinMode(LED_PIN, OUTPUT);
   digitalWrite(LED_PIN, 0);