openvpn/occ.h
2009-05-30 21:38:49 +00:00

96 lines
2.8 KiB
C

/*
* 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) 2002-2009 OpenVPN Technologies, Inc. <sales@openvpn.net>
*
* 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
*/
#ifndef OCC_H
#define OCC_H
#ifdef ENABLE_OCC
#include "forward.h"
/* OCC_STRING_SIZE must be set to sizeof (occ_magic) */
#define OCC_STRING_SIZE 16
/*
* OCC (OpenVPN Configuration Control) protocol opcodes.
*/
#define OCC_REQUEST 0 /* request options string from peer */
#define OCC_REPLY 1 /* deliver options string to peer */
/*
* Send an OCC_REQUEST once every OCC_INTERVAL
* seconds until a reply is received.
*
* If we haven't received a reply after
* OCC_N_TRIES, give up.
*/
#define OCC_INTERVAL_SECONDS 10
#define OCC_N_TRIES 12
/*
* Other OCC protocol opcodes used to estimate the MTU empirically.
*/
#define OCC_MTU_LOAD_REQUEST 2 /* Ask peer to send a big packet to us */
#define OCC_MTU_LOAD 3 /* Send a big packet to peer */
#define OCC_MTU_REQUEST 4 /* Ask peer to tell us the largest
packet it has received from us so far */
#define OCC_MTU_REPLY 5 /* Send largest packet size to peer */
/*
* Process one command from mtu_load_test_sequence
* once every n seconds, if --mtu-test is specified.
*/
#define OCC_MTU_LOAD_INTERVAL_SECONDS 3
/*
* Send an exit message to remote.
*/
#define OCC_EXIT 6
/*
* Used to conduct a load test command sequence
* of UDP connection for empirical MTU measurement.
*/
struct mtu_load_test
{
int op; /* OCC opcode to send to peer */
int delta; /* determine packet size to send by using
this delta against currently
configured MTU */
};
extern const uint8_t occ_magic[];
static inline bool
is_occ_msg (const struct buffer* buf)
{
return buf_string_match_head (buf, occ_magic, OCC_STRING_SIZE);
}
void process_received_occ_msg (struct context *c);
#endif
#endif