summaryrefslogtreecommitdiff
path: root/app/openvpn/doc/doxygen/doc_eventloop.h
diff options
context:
space:
mode:
Diffstat (limited to 'app/openvpn/doc/doxygen/doc_eventloop.h')
-rw-r--r--app/openvpn/doc/doxygen/doc_eventloop.h67
1 files changed, 67 insertions, 0 deletions
diff --git a/app/openvpn/doc/doxygen/doc_eventloop.h b/app/openvpn/doc/doxygen/doc_eventloop.h
new file mode 100644
index 00000000..a860db68
--- /dev/null
+++ b/app/openvpn/doc/doxygen/doc_eventloop.h
@@ -0,0 +1,67 @@
+/*
+ * OpenVPN -- An application to securely tunnel IP networks
+ * over a single TCP/UDP port, with support for SSL/TLS-based
+ * session authentication and key exchange,
+ * packet encryption, packet authentication, and
+ * packet compression.
+ *
+ * Copyright (C) 2010 Fox Crypto B.V. <openvpn@fox-it.com>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program 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 this program (see the file COPYING included with this
+ * distribution); if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+/**
+ * @file
+ * Main Event Loop module documentation file.
+ */
+
+/**
+ * @defgroup eventloop Main Event Loop module
+ *
+ * This main event loop module drives the packet processing of OpenVPN.
+ *
+ * OpenVPN is an event driven system. Its activities are driven by a main
+ * event loop, which repeatedly waits for one of several predefined events
+ * to occur, and then calls the appropriate module to handle the event.
+ * The major types of network events that OpenVPN processes are:
+ * - A packet can be read from the external network interface.
+ * - The main event loop activates the \link external_multiplexer
+ * External Multiplexer\endlink to read and process the packet.
+ * - A packet can be read from the virtual tun/tap network interface.
+ * - The main event loop activates the \link internal_multiplexer
+ * Internal Multiplexer\endlink to read and process the packet.
+ * - If a packet is ready to be sent out as a VPN tunnel packet: the
+ * external network interface can be written to.
+ * - The main event loop activates the \link external_multiplexer
+ * External Multiplexer\endlink to send the packet.
+ * - If a packet is ready to be sent to a locally reachable destination:
+ * the virtual tun/tap network interface can be written to.
+ * - The main event loop activates the \link internal_multiplexer
+ * Internal Multiplexer\endlink to send the packet.
+ *
+ * Beside these external events, OpenVPN also processes other types of
+ * internal events. These include scheduled events, such as resending of
+ * non-acknowledged control channel messages.
+ *
+ * @par Main event loop implementations
+ *
+ * Depending on the mode in which OpenVPN is running, a different main
+ * event loop function is called to drive the event processing. The
+ * following implementations are available:
+ * - Client mode using UDP or TCP: \c tunnel_point_to_point()
+ * - Server mode using UDP: \c tunnel_server_udp_single_threaded()
+ * - Server mode using TCP: \c tunnel_server_tcp()
+ */