diff options
Diffstat (limited to 'occ.h')
| -rw-r--r-- | occ.h | 95 |
1 files changed, 95 insertions, 0 deletions
@@ -0,0 +1,95 @@ +/* + * 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) 2002-2010 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 |