/**********
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This library is free software; you can redistribute it and/or modify it under
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the terms of the GNU Lesser General Public License as published by the
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Free Software Foundation; either version 3 of the License, or (at your
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option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)
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This library is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
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more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this library; if not, write to the Free Software Foundation, Inc.,
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51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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**********/
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// "mTunnel" multicast access service
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// Copyright (c) 1996-2017 Live Networks, Inc. All rights reserved.
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// Encapsulation trailer for tunnels
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// C++ header
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#ifndef _TUNNEL_ENCAPS_HH
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#define _TUNNEL_ENCAPS_HH
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#ifndef _NET_ADDRESS_HH
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#include "NetAddress.hh"
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#endif
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typedef u_int16_t Cookie;
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class TunnelEncapsulationTrailer {
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// The trailer is layed out as follows:
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// bytes 0-1: source 'cookie'
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// bytes 2-3: destination 'cookie'
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// bytes 4-7: address
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// bytes 8-9: port
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// byte 10: ttl
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// byte 11: command
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// Optionally, there may also be a 4-byte 'auxilliary address'
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// (e.g., for 'source-specific multicast' preceding this)
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// bytes -4 through -1: auxilliary address
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public:
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Cookie& srcCookie()
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{ return *(Cookie*)byteOffset(0); }
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Cookie& dstCookie()
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{ return *(Cookie*)byteOffset(2); }
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u_int32_t& address()
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{ return *(u_int32_t*)byteOffset(4); }
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Port& port()
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{ return *(Port*)byteOffset(8); }
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u_int8_t& ttl()
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{ return *(u_int8_t*)byteOffset(10); }
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u_int8_t& command()
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{ return *(u_int8_t*)byteOffset(11); }
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u_int32_t& auxAddress()
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{ return *(u_int32_t*)byteOffset(-4); }
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private:
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inline char* byteOffset(int charIndex)
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{ return ((char*)this) + charIndex; }
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};
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const unsigned TunnelEncapsulationTrailerSize = 12; // bytes
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const unsigned TunnelEncapsulationTrailerAuxSize = 4; // bytes
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const unsigned TunnelEncapsulationTrailerMaxSize
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= TunnelEncapsulationTrailerSize + TunnelEncapsulationTrailerAuxSize;
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// Command codes:
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// 0: unused
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const u_int8_t TunnelDataCmd = 1;
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const u_int8_t TunnelJoinGroupCmd = 2;
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const u_int8_t TunnelLeaveGroupCmd = 3;
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const u_int8_t TunnelTearDownCmd = 4;
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const u_int8_t TunnelProbeCmd = 5;
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const u_int8_t TunnelProbeAckCmd = 6;
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const u_int8_t TunnelProbeNackCmd = 7;
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const u_int8_t TunnelJoinRTPGroupCmd = 8;
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const u_int8_t TunnelLeaveRTPGroupCmd = 9;
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// 0x0A through 0x10: currently unused.
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const u_int8_t TunnelExtensionFlag = 0x80; // a flag, not a cmd code
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const u_int8_t TunnelDataAuxCmd
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= (TunnelExtensionFlag|TunnelDataCmd);
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const u_int8_t TunnelJoinGroupAuxCmd
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= (TunnelExtensionFlag|TunnelJoinGroupCmd);
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const u_int8_t TunnelLeaveGroupAuxCmd
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= (TunnelExtensionFlag|TunnelLeaveGroupCmd);
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// Note: the TearDown, Probe, ProbeAck, ProbeNack cmds have no Aux version
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// 0x84 through 0x87: currently unused.
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const u_int8_t TunnelJoinRTPGroupAuxCmd
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= (TunnelExtensionFlag|TunnelJoinRTPGroupCmd);
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const u_int8_t TunnelLeaveRTPGroupAuxCmd
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= (TunnelExtensionFlag|TunnelLeaveRTPGroupCmd);
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// 0x8A through 0xFF: currently unused
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inline Boolean TunnelIsAuxCmd(u_int8_t cmd) {
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return (cmd&TunnelExtensionFlag) != 0;
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}
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#endif
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