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/*
* pconfig.h
* ptunnel is licensed under the BSD license:
*
* Copyright (c) 2004-2011, Daniel Stoedle <daniels@cs.uit.no>,
* Yellow Lemon Software. All rights reserved.
*
* Copyright (c) 2017-2019, Toni Uhlig <matzeton@googlemail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* - Neither the name of the Yellow Lemon Software nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* Contacting the author:
* You can get in touch with me, Daniel Stødle (that's the Norwegian letter oe,
* in case your text editor didn't realize), here: <daniels@cs.uit.no>
*
* The official ptunnel website is here:
* <http://www.cs.uit.no/~daniels/PingTunnel/>
*
* Note that the source code is best viewed with tabs set to 4 spaces.
*/
#ifndef PCONFIG_H
#define PCONFIG_H 1
enum {
/** Set this constant to the number of
* concurrent connections you wish to handle by default.
*/
kMax_tunnels = 10,
/** numbers */
kIP_packet_max_size = 576,
/** In bytes, mind you */
kIP_header_size = 20,
kIP_actual_size = (kIP_packet_max_size - kIP_header_size) - ((kIP_packet_max_size - kIP_header_size) % 8),
/** Also in bytes */
kICMP_header_size = 8,
/** This constant control the maximum size of
* the payload-portion of the ICMP packets
* we send. Note that this does not include
* the IP or ICMP headers!
*/
kDefault_buf_size = 1024,
/** Type code for echo request and replies */
kICMP_echo_request = 8,
kICMP_echo_reply = 0,
/** number of packets we can have in our send/receive ring */
kPing_window_size = 64,
/** Tunnels are automatically closed after one minute of inactivity. Since
* we continously send acknowledgements between the two peers, this mechanism
* won't disconnect "valid" connections.
*/
kAutomatic_close_timeout = 60, // Seconds!
/** size of md5 digest in bytes */
kMD5_digest_size = 16,
/** size of sha512 digest in bytes */
kSHA512_digest_size = 64,
kDNS_port = 53
};
enum oper_mode {
/** Ping tunnel's operating mode (client) */
kMode_forward = 0,
/** Ping tunnel's operating mode (server) */
kMode_proxy
};
enum pkt_flag {
/** set when packet comes from a user */
kUser_flag = 1 << 30,
/** set when packet comes from the proxy */
kProxy_flag = 1 << 31,
kFlag_mask = kUser_flag | kProxy_flag
};
enum log_level {
/** Different verbosity levels. */
kNo_log = -1,
kLog_error = 0,
kLog_info,
kLog_event,
kLog_verbose,
kLog_debug,
kLog_sendrecv
};
enum proxy_state {
/** These constants are used to indicate the protocol state. The protocol
* works as follows:
* - The identifier is used by both the proxy and the forwarder
* to identify the session (and thus the relevant sockets).
* - The seq-no of the ping packet is used in a sliding-window-esque
* way, and to identify the order of data.
*
* The protocol can be in any of the following states:
* kProxy_start Causes the proxy to open a connection to the given
* host and port, associating the ID with the socket,
* before the data on the socket are transmitted.
* kProxy_data Indicates that the packet contains data from the proxy.
* Data ordering is indicated by the seq-no, which will start
* at 0. (The proxy and forwarder maintain different seq-nos.)
* kUser_data This packet contains user data.
* kConnection_close Indicates that the connection is being closed.
* kProxy_ack and Acknowledges the packet (and all packets before it) with seq_no = ack.
* kUser_ack This is used if there are no implicit acknowledgements due to data
* being sent.
*
* Acknowledgements work by the remote peer acknowledging the last
* continuous seq no it has received.
*
* Note: A proxy receiving a kProxy_data packet, or a user receiving a
* kUser_data packet, should ignore it, as it is the host operating system
* actually returning the ping. This is mostly relevant for users, and for
* proxies running in unprivileged mode.
*/
kProxy_start = 0,
kProto_ack,
kProto_data,
kProto_close,
kProto_authenticate,
kNum_proto_types
};
#endif
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