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unison/src/network/utils/error-model.h
2014-03-13 09:29:47 +01:00

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2007 University of Washington
* Copyright (c) 2013 ResiliNets, ITTC, University of Kansas
*
* 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
*
*
* This file incorporates work covered by the following copyright and
* permission notice:
*
* Copyright (c) 1997 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor of the Laboratory may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* Contributed by the Daedalus Research Group, UC Berkeley
* (http://daedalus.cs.berkeley.edu)
*
* This code has been ported from ns-2 (queue/errmodel.{cc,h}
*/
/* BurstErrorModel additions
*
* Author: Truc Anh N. Nguyen <annguyen@ittc.ku.edu>
* ResiliNets Research Group http://wiki.ittc.ku.edu/resilinets
* James P.G. Sterbenz <jpgs@ittc.ku.edu>, director
*/
#ifndef ERROR_MODEL_H
#define ERROR_MODEL_H
#include <list>
#include "ns3/object.h"
#include "ns3/random-variable-stream.h"
namespace ns3 {
class Packet;
/**
* \ingroup network
* \defgroup errormodel Error Model
*/
/**
* \ingroup errormodel
* \brief General error model that can be used to corrupt packets
*
* This object is used to flag packets as being lost/errored or not.
* It is part of the Object framework and can be aggregated to
* other ns3 objects and handled by the Ptr class.
*
* The main method is IsCorrupt(Ptr<Packet> p) which returns true if
* the packet is to be corrupted according to the underlying model.
* Depending on the error model, the packet itself may have its packet
* data buffer errored or not, or side information may be returned to
* the client in the form of a packet tag. (Note: No such error models
* that actually error the bits in a packet presently exist).
* The object can have state (resettable by Reset()).
* The object can also be enabled and disabled via two public member functions.
*
* Typical code (simplified) to use an ErrorModel may look something like
* this:
* \code
* Ptr<ErrorModel> rem = CreateObject<RateErrorModel> ();
* Ptr<UniformRandomVariable> uv = CreateObject<UniformRandomVariable> ();
* rem->SetRandomVariable (uv);
* rem->SetRate (0.001);
* ...
* Ptr<Packet> p;
* if (rem->IsCorrupt (p))
* {
* dropTrace(p);
* } else {
* Forward (p);
* }
* \endcode
*
* Four practical error models, a RateErrorModel, a BurstErrorModel,
* a ListErrorModel, and a ReceiveListErrorModel, are currently implemented.
*/
class ErrorModel : public Object
{
public:
/**
* \brief Get the type ID.
* \return the object TypeId
*/
static TypeId GetTypeId (void);
ErrorModel ();
virtual ~ErrorModel ();
/**
* Note: Depending on the error model, this function may or may not
* alter the contents of the packet upon returning true.
*
* \returns true if the Packet is to be considered as errored/corrupted
* \param pkt Packet to apply error model to
*/
bool IsCorrupt (Ptr<Packet> pkt);
/**
* Reset any state associated with the error model
*/
void Reset (void);
/**
* Enable the error model
*/
void Enable (void);
/**
* Disable the error model
*/
void Disable (void);
/**
* \return true if error model is enabled; false otherwise
*/
bool IsEnabled (void) const;
private:
/**
* Corrupt a packet according to the specified model.
* \param p the packet to corrupt
* \returns true if the packet is corrupted
*/
virtual bool DoCorrupt (Ptr<Packet> p) = 0;
/**
* Re-initialize any state
*/
virtual void DoReset (void) = 0;
bool m_enable; //!< True if the error model is enabled
};
/**
* \brief Determine which packets are errored corresponding to an underlying
* distribution, rate, and unit.
*
* This object is used to flag packets as being lost/errored or not.
* The two parameters that govern the behavior are the rate (or
* equivalently, the mean duration/spacing between errors), and the
* unit (which may be per-bit, per-byte, and per-packet).
* Users can optionally provide a RandomVariableStream object; the default
* is to use a Uniform(0,1) distribution.
* Reset() on this model will do nothing
*
* IsCorrupt() will not modify the packet data buffer
*/
class RateErrorModel : public ErrorModel
{
public:
/**
* \brief Get the type ID.
* \return the object TypeId
*/
static TypeId GetTypeId (void);
RateErrorModel ();
virtual ~RateErrorModel ();
/**
* Error unit. The error model can be packet, Byte or bit based.
*/
enum ErrorUnit
{
ERROR_UNIT_BIT,
ERROR_UNIT_BYTE,
ERROR_UNIT_PACKET
};
/**
* \returns the ErrorUnit being used by the underlying model
*/
RateErrorModel::ErrorUnit GetUnit (void) const;
/**
* \param error_unit the ErrorUnit to be used by the underlying model
*/
void SetUnit (enum ErrorUnit error_unit);
/**
* \returns the error rate being applied by the model
*/
double GetRate (void) const;
/**
* \param rate the error rate to be used by the model
*/
void SetRate (double rate);
/**
* \param ranvar A random variable distribution to generate random variates
*/
void SetRandomVariable (Ptr<RandomVariableStream>);
/**
* Assign a fixed random variable stream number to the random variables
* used by this model. Return the number of streams (possibly zero) that
* have been assigned.
*
* \param stream first stream index to use
* \return the number of stream indices assigned by this model
*/
int64_t AssignStreams (int64_t stream);
private:
virtual bool DoCorrupt (Ptr<Packet> p);
/**
* Corrupt a packet (packet unit).
* \param p the packet to corrupt
* \returns true if the packet is corrupted
*/
virtual bool DoCorruptPkt (Ptr<Packet> p);
/**
* Corrupt a packet (Byte unit).
* \param p the packet to corrupt
* \returns true if the packet is corrupted
*/
virtual bool DoCorruptByte (Ptr<Packet> p);
/**
* Corrupt a packet (bit unit).
* \param p the packet to corrupt
* \returns true if the packet is corrupted
*/
virtual bool DoCorruptBit (Ptr<Packet> p);
virtual void DoReset (void);
enum ErrorUnit m_unit; //!< Error rate unit
double m_rate; //!< Error rate
Ptr<RandomVariableStream> m_ranvar; //!< rng stream
};
/**
* \brief Determine which bursts of packets are errored corresponding to
* an underlying distribution, burst rate, and burst size.
*
* This object is used to flag packets as being lost/errored or not.
* The two parameters that govern the behavior are the burst rate (or
* equivalently, the mean duration/spacing between between error events),
* and the burst size (or equivalently, the number of packets being flagged
* as errored at each error event).
*
* Users can optionally provide RandomVariableStream objects;
* the default for the decision variable is to use a Uniform(0,1) distribution;
* the default for the burst size (number of packets) is to use a
* discrete Uniform[1,4] distribution.
*
* For every packet, the model generates a random number based on the
* decision variable, and compares it with the burst error rate to
* determine if a burst error event should occur.
* If a new error event occurs, the model to will generate a new burst size
* to determine how many packets should be dropped in this particular burst
* error event in addition to the current packet.
*
* When a second packet arrives, the model again determines if a new error
* event should occur based on a newly generated decision variable and
* the burst error rate. If a new error event is determined to occur,
* the model will restart with a new burst size. Otherwise, the model will
* resume the last error event and drop the packet provided that the
* total number of packets that has been dropped does not exceed the
* burst size.
*
* IsCorrupt() will not modify the packet data buffer
*/
class BurstErrorModel : public ErrorModel
{
public:
/**
* \brief Get the type ID.
* \return the object TypeId
*/
static TypeId GetTypeId (void);
BurstErrorModel ();
virtual ~BurstErrorModel ();
/**
* \returns the error rate being applied by the model
*/
double GetBurstRate (void) const;
/**
* \param rate the error rate to be used by the model
*/
void SetBurstRate (double rate);
/**
* \param ranVar A random variable distribution to generate random variates
*/
void SetRandomVariable (Ptr<RandomVariableStream> ranVar);
/**
* \param burstSz A random variable distribution to generate random burst size
*/
void SetRandomBurstSize (Ptr<RandomVariableStream> burstSz);
/**
* Assign a fixed random variable stream number to the random variables
* used by this model. Return the number of streams (possibly zero) that
* have been assigned.
*
* \param stream first stream index to use
* \return the number of stream indices assigned by this model
*/
int64_t AssignStreams (int64_t stream);
private:
virtual bool DoCorrupt (Ptr<Packet> p);
virtual void DoReset (void);
double m_burstRate; //!< the burst error event
Ptr<RandomVariableStream> m_burstStart; //!< the error decision variable
Ptr<RandomVariableStream> m_burstSize; //!< the number of packets being flagged as errored
/**
* keep track of the number of packets being errored
* until it reaches m_burstSize
*/
uint32_t m_counter;
uint32_t m_currentBurstSz; //!< the current burst size
};
/**
* \brief Provide a list of Packet uids to corrupt
*
* This object is used to flag packets as being lost/errored or not.
* A note on performance: the list is assumed to be unordered, and
* in general, Packet uids received may be unordered. Therefore,
* each call to IsCorrupt() will result in a walk of the list with
* the present underlying implementation.
*
* Note also that if one wants to target multiple packets from looking
* at an (unerrored) trace file, the act of erroring a given packet may
* cause subsequent packet uids to change. For instance, suppose one wants
* to error packets 11 and 17 on a given device. It may be that erroring
* packet 11 will cause the subsequent uid stream to change and 17 may no
* longer correspond to the second packet that one wants to lose. Therefore,
* be advised that it might take some trial and error to select the
* right uids when multiple are provided.
*
* Reset() on this model will clear the list
*
* IsCorrupt() will not modify the packet data buffer
*/
class ListErrorModel : public ErrorModel
{
public:
/**
* \brief Get the type ID.
* \return the object TypeId
*/
static TypeId GetTypeId (void);
ListErrorModel ();
virtual ~ListErrorModel ();
/**
* \return a copy of the underlying list
*/
std::list<uint32_t> GetList (void) const;
/**
* \param packetlist The list of packet uids to error.
*
* This method overwrites any previously provided list.
*/
void SetList (const std::list<uint32_t> &packetlist);
private:
virtual bool DoCorrupt (Ptr<Packet> p);
virtual void DoReset (void);
/// Typedef: packet Uid list
typedef std::list<uint32_t> PacketList;
/// Typedef: packet Uid list const iterator
typedef std::list<uint32_t>::const_iterator PacketListCI;
PacketList m_packetList; //!< container of Uid of packets to corrupt
};
/**
* \brief Provide a list of Packets to corrupt
*
* This model also processes a user-generated list of packets to
* corrupt, except that the list corresponds to the sequence of
* received packets as observed by this error model, and not the
* Packet UID.
*
* Reset() on this model will clear the list
*
* IsCorrupt() will not modify the packet data buffer
*/
class ReceiveListErrorModel : public ErrorModel
{
public:
/**
* \brief Get the type ID.
* \return the object TypeId
*/
static TypeId GetTypeId (void);
ReceiveListErrorModel ();
virtual ~ReceiveListErrorModel ();
/**
* \return a copy of the underlying list
*/
std::list<uint32_t> GetList (void) const;
/**
* \param packetlist The list of packets to error.
*
* This method overwrites any previously provided list.
*/
void SetList (const std::list<uint32_t> &packetlist);
private:
virtual bool DoCorrupt (Ptr<Packet> p);
virtual void DoReset (void);
/// Typedef: packet sequence number list
typedef std::list<uint32_t> PacketList;
/// Typedef: packet sequence number list const iterator
typedef std::list<uint32_t>::const_iterator PacketListCI;
PacketList m_packetList; //!< container of sequence number of packets to corrupt
uint32_t m_timesInvoked; //!< number of times the error model has been invoked
};
} // namespace ns3
#endif