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/**********
This library is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the
Free Software Foundation; either version 2.1 of the License, or (at your
option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)
This library 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 Lesser General Public License for
more details.
You should have received a copy of the GNU Lesser General Public License
along with this library; if not, write to the Free Software Foundation, Inc.,
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
**********/
// "mTunnel" multicast access service
// Copyright (c) 1996-1998 Live Networks, Inc. All rights reserved.
// Encapsulation trailer for tunnels
// C++ header
#ifndef _TUNNEL_ENCAPS_HH
#define _TUNNEL_ENCAPS_HH
#ifndef _NET_ADDRESS_HH
#include "NetAddress.hh"
#endif
typedef u_int16_t Cookie;
class TunnelEncapsulationTrailer {
// The trailer is layed out as follows:
// bytes 0-1: source 'cookie'
// bytes 2-3: destination 'cookie'
// bytes 4-7: address
// bytes 8-9: port
// byte 10: ttl
// byte 11: command
// Optionally, there may also be a 4-byte 'auxilliary address'
// (e.g., for 'source-specific multicast' preceding this)
// bytes -4 through -1: auxilliary address
public:
Cookie& srcCookie()
{ return *(Cookie*)byteOffset(0); }
Cookie& dstCookie()
{ return *(Cookie*)byteOffset(2); }
u_int32_t& address()
{ return *(u_int32_t*)byteOffset(4); }
Port& port()
{ return *(Port*)byteOffset(8); }
u_int8_t& ttl()
{ return *(u_int8_t*)byteOffset(10); }
u_int8_t& command()
{ return *(u_int8_t*)byteOffset(11); }
u_int32_t& auxAddress()
{ return *(u_int32_t*)byteOffset(-4); }
private:
inline char* byteOffset(int charIndex)
{ return ((char*)this) + charIndex; }
};
const unsigned TunnelEncapsulationTrailerSize = 12; // bytes
const unsigned TunnelEncapsulationTrailerAuxSize = 4; // bytes
const unsigned TunnelEncapsulationTrailerMaxSize
= TunnelEncapsulationTrailerSize + TunnelEncapsulationTrailerAuxSize;
// Command codes:
// 0: unused
const u_int8_t TunnelDataCmd = 1;
const u_int8_t TunnelJoinGroupCmd = 2;
const u_int8_t TunnelLeaveGroupCmd = 3;
const u_int8_t TunnelTearDownCmd = 4;
const u_int8_t TunnelProbeCmd = 5;
const u_int8_t TunnelProbeAckCmd = 6;
const u_int8_t TunnelProbeNackCmd = 7;
const u_int8_t TunnelJoinRTPGroupCmd = 8;
const u_int8_t TunnelLeaveRTPGroupCmd = 9;
// 0x0A through 0x10: currently unused.
const u_int8_t TunnelExtensionFlag = 0x80; // a flag, not a cmd code
const u_int8_t TunnelDataAuxCmd
= (TunnelExtensionFlag|TunnelDataCmd);
const u_int8_t TunnelJoinGroupAuxCmd
= (TunnelExtensionFlag|TunnelJoinGroupCmd);
const u_int8_t TunnelLeaveGroupAuxCmd
= (TunnelExtensionFlag|TunnelLeaveGroupCmd);
// Note: the TearDown, Probe, ProbeAck, ProbeNack cmds have no Aux version
// 0x84 through 0x87: currently unused.
const u_int8_t TunnelJoinRTPGroupAuxCmd
= (TunnelExtensionFlag|TunnelJoinRTPGroupCmd);
const u_int8_t TunnelLeaveRTPGroupAuxCmd
= (TunnelExtensionFlag|TunnelLeaveRTPGroupCmd);
// 0x8A through 0xFF: currently unused
inline Boolean TunnelIsAuxCmd(u_int8_t cmd) {
return (cmd&TunnelExtensionFlag) != 0;
}
#endif
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