Fix handling of UDP datagrams and TCP streams

Author: Veijo Pesonen

ESP8266/ESP8266.cpp

@@ -373,7 +373,7 @@ void ESP8266::_packet_handler()
     _packets_end = &packet->next;
 }
 
-int32_t ESP8266::recv(int id, void *data, uint32_t amount)
+int32_t ESP8266::recv_tcp(int id, void *data, uint32_t amount)
 {
     _smutex.lock();
     // Poll for inbound packets
@@ -415,7 +415,39 @@ int32_t ESP8266::recv(int id, void *data, uint32_t amount)
 
     _smutex.unlock();
 
-    return -1;
+    return NSAPI_ERROR_WOULD_BLOCK;
+}
+
+int32_t ESP8266::recv_udp(int id, void *data, uint32_t amount)
+{
+    _smutex.lock();
+    // Poll for inbound packets
+    while (_parser.process_oob()) {
+    }
+
+    // check if any packets are ready for us
+    for (struct packet **p = &_packets; *p; p = &(*p)->next) {
+        if ((*p)->id == id) {
+            struct packet *q = *p;
+
+            // Return and remove packet (truncated if necessary)
+            uint32_t len = q->len < amount ? q->len : amount;
+            memcpy(data, q+1, len);
+
+            if (_packets_end == &(*p)->next) {
+                _packets_end = p;
+            }
+            *p = (*p)->next;
+            _smutex.unlock();
+
+            free(q);
+            return len;
+        }
+    }
+
+    _smutex.unlock();
+
+    return NSAPI_ERROR_WOULD_BLOCK;
 }
 
 bool ESP8266::close(int id)

ESP8266/ESP8266.h

@@ -164,14 +164,24 @@ class ESP8266
     nsapi_error_t send(int id, const void *data, uint32_t amount);
 
     /**
-    * Receives data from an open socket
+    * Receives datagram from an open UDP socket
     *
     * @param id id to receive from
     * @param data placeholder for returned information
     * @param amount number of bytes to be received
     * @return the number of bytes received
     */
-    int32_t recv(int id, void *data, uint32_t amount);
+    int32_t recv_udp(int id, void *data, uint32_t amount);
+
+    /**
+    * Receives stream data from an open TCP socket
+    *
+    * @param id id to receive from
+    * @param data placeholder for returned information
+    * @param amount number of bytes to be received
+    * @return the number of bytes received
+    */
+    int32_t recv_tcp(int id, void *data, uint32_t amount);
 
     /**
     * Closes a socket

ESP8266Interface.cpp

@@ -424,12 +424,14 @@ int ESP8266Interface::socket_recv(void *handle, void *data, unsigned size)
     struct esp8266_socket *socket = (struct esp8266_socket *)handle;
     _esp.setTimeout(ESP8266_RECV_TIMEOUT);
 
-    int32_t recv = _esp.recv(socket->id, data, size);
-    if(recv == 0) {
-        socket->connected = false; // No more data, ESP has closed the socket
-    }
-    if (recv < 0) {
-        return NSAPI_ERROR_WOULD_BLOCK;
+    int32_t recv;
+    if (socket->proto == NSAPI_TCP) {
+        recv = _esp.recv_tcp(socket->id, data, size);
+        if (recv <= 0) {
+            socket->connected = false;
+        }
+    } else {
+        recv = _esp.recv_udp(socket->id, data, size);
     }
 
     return recv;