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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 _NDN_HEADER_HELPER_H_
#define _NDN_HEADER_HELPER_H_
#include "ns3/ptr.h"
namespace ns3 {
class Header;
class Packet;
namespace ndn {
class Name;
/**
* \ingroup ndn-helpers
*
* \brief Class implementing functionality to detect Ndn packet type and
* create the corresponding object
*
* Ndn doesn't really have a header, so we need this class to
* determine type of Ndn packet and return corresponent header class,
* InterestHeader or ContentObjectHeader
*
* Throws UnknownHeaderException if header type couldn't be determined
*/
class HeaderHelper
{
public:
/**
@brief enum for Ndn packet types
*/
enum Type {INTEREST_CCNB, CONTENT_OBJECT_CCNB,
INTEREST_NDNSIM, CONTENT_OBJECT_NDNSIM};
/**
* Packet ::= Version
* PacketType
* (Interest | ContentObject)
*
* 0 1
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Version | PacketType |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* For ccnb-encoding compatibility, ``Version`` / ``PacketType`` has two reserved values to denote ccnb-encoded packet:
*
* Version 0x01, PacketType 0xD2 --- ccnb-encoded ``Interest`` packet
* Version 0x04, PacketType 0x82 --- ccnb-encoded ``ContentObject`` packet
*
*
* 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
GetNdnHeaderType (Ptr<const Packet> packet);
/**
* @brief A heavy-weight operation to get name of the packet
*
* This function returns name of the packet by deserializing a copy of the packet to a right header
*/
static Ptr<const Name>
GetName (Ptr<const Packet> packet);
};
/**
* \ingroup ndn
* \defgroup ndn-exceptions Exceptions
*/
/**
* \ingroup ndn-exceptions
* \brief Exception thrown if Ndn stack receives unrecognized
* message type
*/
class UnknownHeaderException {};
} // namespace ndn
} // namespace ns3
#endif // _NDN_HEADER_HELPER_H_