| /********** |
| 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 3 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., |
| 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| **********/ |
| // "mTunnel" multicast access service |
| // Copyright (c) 1996-2020 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 |