Remote tcp disconnect not detected (#389)

* Add setNoDelay and getNoDelay to WiFiServer class

* Remote TCP disconnect not detected

libraries/WiFi/src/WiFiClient.cpp

@@ -279,8 +279,28 @@ void WiFiClient::flush() {
 
 uint8_t WiFiClient::connected()
 {
-    uint8_t dummy = 0;
-    read(&dummy, 0);
+    if (_connected) {
+        uint8_t dummy;
+        int res = recv(fd(), &dummy, 0, MSG_DONTWAIT);
+        if (res <= 0) {
+            switch (errno) {
+                case ENOTCONN:
+                case EPIPE:
+                case ECONNRESET:
+                case ECONNREFUSED:
+                case ECONNABORTED:
+                    _connected = false;
+                    break;
+                default:
+                    _connected = true;
+                    break;
+            }
+        }
+        else {
+            // Should never happen since requested 0 bytes
+            _connected = true;
+        }
+    }
     return _connected;
 }
 

libraries/WiFi/src/WiFiServer.cpp

@@ -45,8 +45,11 @@ WiFiClient WiFiServer::available(){
   int client_sock = accept(sockfd, (struct sockaddr *)&_client, (socklen_t*)&cs);
   if(client_sock >= 0){
     int val = 1;
-    if(setsockopt(client_sock, SOL_SOCKET, SO_KEEPALIVE, (char*)&val, sizeof(int)) == ESP_OK)
-      return WiFiClient(client_sock);
+    if(setsockopt(client_sock, SOL_SOCKET, SO_KEEPALIVE, (char*)&val, sizeof(int)) == ESP_OK) {
+      val = _noDelay;
+      if(setsockopt(client_sock, IPPROTO_TCP, TCP_NODELAY, (char*)&val, sizeof(int)) == ESP_OK)
+        return WiFiClient(client_sock);
+    }
   }
   return WiFiClient();
 }
@@ -69,6 +72,14 @@ void WiFiServer::begin(){
   _listening = true;
 }
 
+void WiFiServer::setNoDelay(bool nodelay) {
+    _noDelay = nodelay;
+}
+
+bool WiFiServer::getNoDelay() {
+    return _noDelay;
+}
+
 void WiFiServer::end(){
   close(sockfd);
   sockfd = -1;

libraries/WiFi/src/WiFiServer.h

@@ -29,6 +29,7 @@ class WiFiServer : public Server {
     uint16_t _port;
     uint8_t _max_clients;
     bool _listening;
+    bool _noDelay = false;
 
   public:
     void listenOnLocalhost(){}
@@ -38,6 +39,8 @@ class WiFiServer : public Server {
     WiFiClient available();
     WiFiClient accept(){return available();}
     void begin();
+    void setNoDelay(bool nodelay);
+    bool getNoDelay();
     size_t write(const uint8_t *data, size_t len);
     size_t write(uint8_t data){
       return write(&data, 1);