Add retry for email sending (#2963).2963-retry-email

1 files changed, 79 insertions, 0 deletions

diff --git a/test/smtp_server.cc b/test/smtp_server.cc
new file mode 100644
index 000000000..c6802bded
--- /dev/null
+++ b/test/smtp_server.cc
@@ -0,0 +1,79 @@
+/*
+    Copyright (C) 2025 Carl Hetherington <cth@carlh.net>
+
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    DCP-o-matic is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+
+#include "smtp_server.h"
+#include <boost/asio.hpp>
+#include <iostream>
+#include <string>
+
+
+using std::string;
+using boost::asio::ip::tcp;
+
+
+void
+run_smtp_server(int port, bool fail)
+{
+	boost::asio::io_context context;
+	tcp::acceptor acceptor(context, tcp::endpoint(tcp::v4(), port));
+	tcp::socket socket(context);
+	acceptor.accept(socket);
+
+	auto send = [&socket](string message) {
+		boost::system::error_code error;
+		boost::asio::write(socket, boost::asio::buffer(message + "\r\n"), boost::asio::transfer_all(), error);
+	};
+
+	auto receive = [&socket]() {
+		boost::asio::streambuf buffer;
+		boost::asio::read_until(socket, buffer, "\n");
+		return string{
+			std::istreambuf_iterator<char>(&buffer),
+			std::istreambuf_iterator<char>()
+		};
+	};
+
+	send("220 smtp.example.com ESMTP Postfix");
+	/* EHLO */
+	receive();
+	send("250-smtp.example.com Hello mate [127.0.0.1]");
+	send("250-SIZE 14680064");
+	send("250-PIPELINING");
+	send("250 HELP");
+	/* MAIL FROM */
+	receive();
+	send("250 Ok");
+	/* RCPT TO */
+	if (fail) {
+		return;
+	}
+	receive();
+	send("250 Ok");
+	/* DATA */
+	receive();
+	send("354 End data with <CR><LF>.<CR><LF>");
+	/* Email body */
+	receive();
+	send("250 Ok");
+	/* QUIT */
+	receive();
+}
+