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/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
/*
* Copyright (c) 2011 University of California, Los Angeles
*
* 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; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
*/
#ifndef _CCNX_HEADER_HELPER_H_
#define _CCNX_HEADER_HELPER_H_
#include "ns3/ptr.h"
#define INTEREST_BYTE0 0x01
#define INTEREST_BYTE1 0xD2
#define CONTENT_OBJECT_BYTE0 0x04
#define CONTENT_OBJECT_BYTE1 0x82
namespace ns3
{
class Header;
class Packet;
/**
* \ingroup ccnx-helpers
*
* \brief Class implementing functionality to detect CCNx packet type and
* create the corresponding object
*
* CCNx doesn't really have a header, so we need this class to
* determine type of CCNx packet and return corresponent header class,
* CcnxInterestHeader or CcnxContentObjectHeader
*
* Throws CcnxUnknownHeaderException if header type couldn't be determined
*/
class CcnxHeaderHelper
{
public:
enum Type {INTEREST, CONTENT_OBJECT};
/**
* Static function to create an appropriate CCNx header
*
* It peeks first 2 bytes of a packet.
*
* All interests start with
* +-----------------+ +---+---------+-------+
* | 0 0 0 0 0 0 0 1 | | 1 | 1 0 1 0 | 0 1 0 | (0x01 0xD2)
* +-----------------+ +---+---------+-------+
*
* All content objects start with
* +-----------------+ +---+---------+-------+
* | 0 0 0 0 0 1 0 0 | | 1 | 0 0 0 0 | 0 1 0 | (0x04 0x82)
* +-----------------+ +---+---------+-------+
* ^ ^^^^^
* | |
* terminator DTAG (Dictionary TAG)
*
* \see http://www.ccnx.org/releases/latest/doc/technical/BinaryEncoding.html
*/
static Type
CreateCorrectCcnxHeader (Ptr<const Packet> packet);
};
/**
* \ingroup ccnx
* \defgroup ccnx-exceptions Exceptions
*/
/**
* \ingroup ccnx-exceptions
* \brief Exception thrown if CCNx stack receives unrecognized
* message type
*/
class CcnxUnknownHeaderException {};
} // namespace ns3
#endif // _CCNX_HEADER_HELPER_H_