Correct handling of SIGINT signal in client networking layer

plugins/ua_network_tcp.c

@@ -182,10 +182,11 @@ connection_releaserecvbuffer(UA_Connection *connection,
 
 static UA_StatusCode
 connection_write(UA_Connection *connection, UA_ByteString *buf) {
-    if (connection->state == UA_CONNECTION_CLOSED) {
+    if(connection->state == UA_CONNECTION_CLOSED) {
         UA_ByteString_deleteMembers(buf);
         return UA_STATUSCODE_BADCONNECTIONCLOSED;
     }
+
     /* Prevent OS signals when sending to a closed socket */
     int flags = 0;
 #ifdef MSG_NOSIGNAL
@@ -218,8 +219,9 @@ connection_write(UA_Connection *connection, UA_ByteString *buf) {
 static UA_StatusCode
 connection_recv(UA_Connection *connection, UA_ByteString *response,
                 UA_UInt32 timeout) {
-    if (connection->state == UA_CONNECTION_CLOSED)
+    if(connection->state == UA_CONNECTION_CLOSED)
         return UA_STATUSCODE_BADCONNECTIONCLOSED;
+
     /* Listen on the socket for the given timeout until a message arrives */
     if(timeout > 0) {
         fd_set fdset;
@@ -235,8 +237,13 @@ connection_recv(UA_Connection *connection, UA_ByteString *response,
         if(resultsize == 0)
             return UA_STATUSCODE_GOODNONCRITICALTIMEOUT;
 
-        /* Error occurred */
-        if (resultsize == -1) {
+        if(resultsize == -1) {
+            /* The call to select was interrupted manually. Act as if it timed
+             * out */
+            if(errno == EINTR)
+                return UA_STATUSCODE_GOODNONCRITICALTIMEOUT;
+
+            /* The error cannot be recovered. Close the connection. */
             connection->close(connection);
             return UA_STATUSCODE_BADCONNECTIONCLOSED;
         }
@@ -878,8 +885,8 @@ UA_ClientConnectionTCP(UA_ConnectionConfig conf,
             ClientNetworkLayerTCP_close(&connection);
             UA_LOG_SOCKET_ERRNO_WRAP(
                     UA_LOG_WARNING(logger, UA_LOGCATEGORY_NETWORK,
-                                          "Connection to %s failed with error: %s",
-                                          endpointUrl, errno_str));
+                                   "Connection to %s failed with error: %s",
+                                   endpointUrl, errno_str));
             freeaddrinfo(server);
             return connection;
         }