MAISTRA-1166: Treat EAGAIN as SSL_ERROR_WANT_READ (#46)

Co-authored-by: Kevin Conner <kconner@redhat.com>
(cherry picked from commit d4bd4cfa0dc513e7833fbe117ba0b3479ef86038)

Signed-off-by: Brian Avery <bavery@redhat.com>

source/extensions/transport_sockets/tls/ssl_socket.cc

@@ -152,10 +152,16 @@ Network::IoResult SslSocket::doRead(Buffer::Instance& read_buffer) {
             break;
           }
           FALLTHRU;
+        case SSL_ERROR_SSL:
+          // If EAGAIN treat it as if it's SSL_ERROR_WANT_READ
+          if (errno == EAGAIN) {
+            break;
+          }
+          // fall through for other errors
         case SSL_ERROR_WANT_WRITE:
         // Renegotiation has started. We don't handle renegotiation so just fall through.
         default:
-          drainErrorQueue();
+          drainErrorQueue(true);
           action = PostIoAction::Close;
           break;
         }