Merge pull request #16 from ARMmbed/fix-recvfrom-address

Fix invalid SocketAddress returned from recvfrom

Author: geky

ESP8266Interface.cpp

@@ -131,6 +131,7 @@ struct esp8266_socket {
     int id;
     nsapi_protocol_t proto;
     bool connected;
+    SocketAddress addr;
 };
 
 int ESP8266Interface::socket_open(void **handle, nsapi_protocol_t proto)
@@ -234,20 +235,35 @@ int ESP8266Interface::socket_recv(void *handle, void *data, unsigned size)
 int ESP8266Interface::socket_sendto(void *handle, const SocketAddress &addr, const void *data, unsigned size)
 {
     struct esp8266_socket *socket = (struct esp8266_socket *)handle;
+
+    if (socket->connected && socket->addr != addr) {
+        _esp.setTimeout(ESP8266_MISC_TIMEOUT);
+        if (!_esp.close(socket->id)) {
+            return NSAPI_ERROR_DEVICE_ERROR;
+        }
+        socket->connected = false;
+    }
+
     if (!socket->connected) {
         int err = socket_connect(socket, addr);
         if (err < 0) {
             return err;
         }
+        socket->addr = addr;
     }
 
     return socket_send(socket, data, size);
 }
 
 int ESP8266Interface::socket_recvfrom(void *handle, SocketAddress *addr, void *data, unsigned size)
 {
-    struct esp8266_socket *socket = (struct esp8266_socket *)handle;    
-    return socket_recv(socket, data, size);
+    struct esp8266_socket *socket = (struct esp8266_socket *)handle;
+    int ret = socket_recv(socket, data, size);
+    if (ret >= 0 && addr) {
+        *addr = socket->addr;
+    }
+
+    return ret;
 }
 
 void ESP8266Interface::socket_attach(void *handle, void (*callback)(void *), void *data)

ESP8266Interface.h

@@ -124,6 +124,29 @@ class ESP8266Interface : public NetworkStack, public WiFiInterface
      */
     virtual int scan(WiFiAccessPoint *res, unsigned count);
 
+    /** Translates a hostname to an IP address with specific version
+     *
+     *  The hostname may be either a domain name or an IP address. If the
+     *  hostname is an IP address, no network transactions will be performed.
+     *
+     *  If no stack-specific DNS resolution is provided, the hostname
+     *  will be resolve using a UDP socket on the stack.
+     *
+     *  @param address  Destination for the host SocketAddress
+     *  @param host     Hostname to resolve
+     *  @param version  IP version of address to resolve, NSAPI_UNSPEC indicates
+     *                  version is chosen by the stack (defaults to NSAPI_UNSPEC)
+     *  @return         0 on success, negative error code on failure
+     */
+    using NetworkInterface::gethostbyname;
+
+    /** Add a domain name server to list of servers to query
+     *
+     *  @param addr     Destination for the host address
+     *  @return         0 on success, negative error code on failure
+     */
+    using NetworkInterface::add_dns_server;
+
 protected:
     /** Open a socket
      *  @param handle       Handle in which to store new socket