ls.h

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// Copyright (c) 2000 by the University of Southern California
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//  Copyright (C) 1998 by Mingzhou Sun. All rights reserved.
//  This software is developed at Rensselaer Polytechnic Institute under 
//  DARPA grant No. F30602-97-C-0274
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//  provided that the above copyright notice and this paragraph are
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// $Header: /nfs/jade/vint/CVSROOT/ns-2/linkstate/ls.h,v 1.5 2002/10/09 03:47:00 difa Exp $

#ifndef ns_ls_h
#define ns_ls_h

#include <sys/types.h> 
#include <list>
#include <map>
#include <utility>

#include "timer-handler.h"

const int LS_INVALID_COUNT = -1;
const int LS_INIT_ACCESS_COUNT = 3;
const int LS_INVALID_NODE_ID = 65535;
const int LS_INVALID_COST = 65535;
const int LS_MIN_COST = 0;
const int LS_MAX_COST = 65534;
const int LS_MESSAGE_CENTER_SIZE_FACTOR = 4; // times the number of nodes 
const int LS_DEFAULT_MESSAGE_SIZE = 100; // in bytes
const int LS_LSA_MESSAGE_SIZE = 100; // in bytes
const double LS_RTX_TIMEOUT = 0.002;  // default to 2ms to begin with
const int LS_TIMEOUT_FACTOR = 3;   // x times of one-way total delay
// Topo message is not too long due to incremental update
const int LS_TOPO_MESSAGE_SIZE = 200; // in bytes
const int LS_ACK_MESSAGE_SIZE = 20; // in bytes
const unsigned int LS_INVALID_MESSAGE_ID = 0;
const unsigned int LS_BIG_NUMBER = 1048576;
const unsigned int LS_WRAPAROUND_THRESHOLD = 1073741824; // 2^30
const unsigned int LS_MESSAGE_TYPES = 6;

enum ls_status_t { 
        LS_STATUS_DOWN = 0, 
        LS_STATUS_UP = 1
};

enum ls_message_type_t { 
        LS_MSG_INVALID = 0, 
        LS_MSG_LSA = 1,         // Link state advertisement
        LS_MSG_TPM = 2,         // Topology map message
        LS_MSG_LSAACK = 3,      // Link state advertisement ACK
        LS_MSG_TPMACK = 4, 
        LS_MSG_LSM = 5, 
};

template <class _Tp>
class LsList : public list<_Tp> {
public:
        typedef list<_Tp> baseList;
        LsList() : baseList() {}
        LsList(const _Tp& x) : baseList(1, x) {}
        void eraseAll() { 
                baseList::erase(begin(), end()); 
        }
        LsList<_Tp>& operator= (const LsList<_Tp> & x) {
                return (LsList<_Tp> &)baseList::operator= (x);
        }
};

template<class Key, class T>
class LsMap : public map<Key, T, less<Key> > {
public:
        typedef less<Key> less_key;
        typedef map<Key, T, less_key> baseMap;
        LsMap() : baseMap() {}

        // this next typedef of iterator seems extraneous but is required by gcc-2.96
        typedef typename map<Key, T, less<Key> >::iterator iterator;
        typedef pair<iterator, bool> pair_iterator_bool;
        iterator insert(const Key & key, const T & item) {
                typename baseMap::value_type v(key, item);
                pair_iterator_bool ib = baseMap::insert(v);
                return ib.second ? ib.first : baseMap::end();
        }

        void eraseAll() { erase(begin(), end()); }
        T* findPtr(Key key) {
                iterator it = baseMap::find(key);
                return (it == baseMap::end()) ? (T *)NULL : &((*it).second);
        }
};

/*
  LsNodeIdList -- A list of int 's. It manages its own memory
*/
class LsNodeIdList : public LsList<int> {
public:
        int appendUnique (const LsNodeIdList& x);
};  

/* -------------------------------------------------------------------*/
/* 
   LsLinkState -- representing a link, contains neighborId, cost and status
*/
struct LsLinkState {
        // public data
        int neighborId_;  
        ls_status_t status_;
        int cost_;
        u_int32_t sequenceNumber_;  

        // public methods
        LsLinkState() : neighborId_(LS_INVALID_NODE_ID),
                status_(LS_STATUS_DOWN), cost_(LS_INVALID_COST) {}
        LsLinkState(int id, ls_status_t s, int c) : neighborId_(id), 
                status_(s), cost_(c) {}

        void init (int nbId, ls_status_t s, int c){
                neighborId_ = nbId;
                status_ = s;
                cost_ =c;
        }
} ;

/* 
   LsLinkStateList 
*/
typedef LsList<LsLinkState> LsLinkStateList;

/* -------------------------------------------------------------------*/
/*
  LsTopoMap
  the Link State Database, the representation of the
  topology within the protocol 
*/
typedef LsMap<int, LsLinkStateList> LsLinkStateListMap;

class LsTopoMap : public LsLinkStateListMap {
public:
        // constructor / destructor 
        // the default ones 
        LsTopoMap() : LsLinkStateListMap() {}
  
        //   // map oeration
        //   iterator begin() { return LsLinkStateListMap::begin();}
        //   iterator end() { return LsLinkStateListMap::end();}
        //  iterator begin() { return baseMap::begin();}
        //   const_iterator begin() const { return  baseMap::begin();}
        //   iterator end() { return baseMap::end();}
        //   const_iterator end() const { return baseMap::end();}

        // insert one link state each time 
        LsLinkStateList* insertLinkState(int nodeId, 
                                         const LsLinkState& linkState);
        // update returns true if there's change
        bool update(int nodeId, const LsLinkStateList& linkStateList);
        //   friend ostream & operator << ( ostream & os, LsTopoMap & x) ;
        void setNodeId(int id) { myNodeId_ = id ;}
private:
        int myNodeId_; // for update()
};

typedef LsTopoMap LsTopology;
typedef LsTopoMap* LsTopoMapPtr;

/*
  LsPath - A struct with destination, cost, nextHop
*/
struct LsPath {
        LsPath() : destination (LS_INVALID_NODE_ID) {}
        LsPath(int dest, int c, int nh)
                : destination (dest), cost(c), nextHop(nh) {}
        // methods
        bool isValid() { 
                return ((destination != LS_INVALID_NODE_ID) && 
                        (cost != LS_INVALID_COST) && 
                        (nextHop != LS_INVALID_COST));
        }

        // public data
        int destination;
        int cost;
        int nextHop;
};

/*
  LsEqualPaths -- A struct with one cost and a list of multiple next hops
  Used by LsPaths
*/
struct LsEqualPaths {
public:
        int  cost;
        LsNodeIdList nextHopList;

        // constructors
        LsEqualPaths() : cost(LS_INVALID_COST) {}
        LsEqualPaths(int c, int nh) : cost(c), nextHopList() {
                nextHopList.push_back(nh);
        }
        LsEqualPaths(const LsPath & path) : cost (path.cost), nextHopList() {
                nextHopList.push_back(path.nextHop);
        }
        LsEqualPaths(int c, const LsNodeIdList & nhList) 
                : cost(c), nextHopList(nhList) {}
  
        LsEqualPaths& operator = (const LsEqualPaths & x ) {
                cost = x.cost;
                nextHopList = x.nextHopList;
                return *this;
        }

        // copy 
        LsEqualPaths& copy(const LsEqualPaths & x) { return operator = (x) ;}

        // appendNextHopList 
        int appendNextHopList(const LsNodeIdList & nhl) {
                return nextHopList.appendUnique (nhl);
        }
};

/* 
   LsEqualPathsMap -- A map of LsEqualPaths
*/
typedef LsMap< int, LsEqualPaths > LsEqualPathsMap;

/*
  LsPaths -- enhanced LsEqualPathsMap, used in LsRouting
*/
class LsPaths : public LsEqualPathsMap {
public:
        LsPaths(): LsEqualPathsMap() {}
  
        // -- map operations 
        iterator begin() { return LsEqualPathsMap::begin();}
        iterator end() { return LsEqualPathsMap::end();}

        // -- specical methods that facilitates computeRoutes of LsRouting
        // lookupCost
        int lookupCost(int destId) {
                LsEqualPaths * pEP = findPtr (destId);
                if ( pEP == NULL ) return LS_MAX_COST + 1;
                // else
                return pEP->cost;
        }

        // lookupNextHopListPtr
        LsNodeIdList* lookupNextHopListPtr(int destId) {
                LsEqualPaths* pEP = findPtr(destId);
                if (pEP == NULL ) 
                        return (LsNodeIdList *) NULL;
                // else
                return &(pEP->nextHopList);
        }
  
        // insertPath without checking validity
        iterator insertPathNoChecking(int destId, int cost, int nextHop) {
                LsEqualPaths ep(cost, nextHop);
                iterator itr = insert(destId, ep);
                return itr; // for clarity
        }     

        // insertPathNoChekcing()
        iterator insertPathNoChecking (const LsPath & path) {
                return insertPathNoChecking(path.destination, path.cost, 
                                            path.nextHop);
        }
        // insertPath(), returns end() if error, else return iterator 
        iterator insertPath(int destId, int cost, int nextHop);
        iterator insertPath(const LsPath& path) {
                return insertPath(path.destination, path.cost, path.nextHop);
        }
        // insertNextHopList 
        iterator insertNextHopList(int destId, int cost, 
                                   const LsNodeIdList& nextHopList);
};

/*
  LsPathsTentative -- Used in LsRouting, remembers min cost and location 
*/
class LsPathsTentative : public LsPaths {
public:
        LsPathsTentative() : LsPaths(), minCost(LS_MAX_COST+1) {
                minCostIterator = end();
        }
  
        // combining get and remove min path
        LsPath popShortestPath();
  
private:
        int minCost; // remembers the min cost
        iterator minCostIterator; // remembers where it's stored
        iterator findMinEqualPaths();
};

/* 
   LsMessage 
*/
struct LsMessage {
        LsMessage() : type_(LS_MSG_INVALID), contentPtr_(NULL) {}
        LsMessage(u_int32_t id, int nodeId, ls_message_type_t t) :
                type_(t), messageId_(id),
                sequenceNumber_(id), originNodeId_(nodeId), 
                contentPtr_(NULL) {}
        ~LsMessage() {
                if ((type_ == LS_MSG_LSM) && (lslPtr_ != NULL)) {
                        delete lslPtr_;
                        lslPtr_ = NULL;
                }
        }
        ls_message_type_t type_;
        u_int32_t messageId_;
        u_int32_t sequenceNumber_; 
        int originNodeId_; 
        union {
                LsLinkStateList* lslPtr_;
                const LsTopoMap* topoPtr_;
                void* contentPtr_;
        };
};

// TODO -- not used, comment out
// Some time we just want the header, since the message has a content
// which will be destroyed with it goes out of scope, 
// used by ack manager
struct LsMessageInfo
{
        ls_message_type_t type_;
        int destId_; 
        u_int32_t msgId_;
        u_int32_t sequenceNumber_;    
        union {
                // for LSA, the originator of the msg
                int originNodeId_;  
                // for LSA_ACK, the originator of the lsa being acked
                int originNodeIdAck_; 
        };
        // constructor 
        LsMessageInfo() {}
        LsMessageInfo(int d, const LsMessage& msg ) :
                type_(msg.type_), destId_(d),  msgId_(msg.messageId_),
                sequenceNumber_(msg.sequenceNumber_),
                originNodeId_(msg.originNodeId_)  {}
        LsMessageInfo(int d , ls_message_type_t t, int o, 
                      u_int32_t seq, u_int32_t mId) :
                type_(t), destId_(d), msgId_(mId), sequenceNumber_(seq), 
                originNodeId_(o) {}
};

/* 
   LsMessageCenter -- Global storage of LsMessage's for retrieval
*/
class LsMessageCenter {
public:
        typedef LsMap <u_int32_t, LsMessage> baseMap;
        // constructor
        LsMessageCenter () 
                : current_lsa_id(LS_INVALID_MESSAGE_ID + 1), 
                current_other_id(LS_INVALID_MESSAGE_ID + 2),
                max_size(0), lsa_messages(), other_messages() {}
  
        void setNodeNumber (int number_of_nodes) {
                max_size = number_of_nodes * LS_MESSAGE_CENTER_SIZE_FACTOR;
        }
        LsMessage* newMessage (int senderNodeId, ls_message_type_t type);
        u_int32_t duplicateMessage( u_int32_t msgId) {
                return msgId;
        }
        u_int32_t duplicateMessage(const LsMessage& msg) {
                return duplicateMessage(msg.messageId_);
        }
        bool deleteMessage(u_int32_t msgId) ;
        bool deleteMessage (const LsMessage& msg) {
                return deleteMessage(msg.messageId_);
        }
        LsMessage* retrieveMessagePtr(u_int32_t msgId){
                if (isLSA(msgId)) {
                        return lsa_messages.findPtr(msgId);
                } else {
                        return other_messages.findPtr(msgId);
                }
        }
        static LsMessageCenter& instance() { 
                return msgctr_;
        }

private:
        static LsMessageCenter msgctr_; // Singleton class

        u_int32_t current_lsa_id ;
        u_int32_t current_other_id;
        unsigned int max_size; // if size() greater than this number, erase begin().
        typedef LsMap <u_int32_t, LsMessage > message_storage;
        message_storage lsa_messages;
        message_storage other_messages;
        void init();
        int isLSA (u_int32_t msgId) {
                // to see if msgId's last bit is different from 
                // LS_INVALID_MESSAGE_ID
                return (0x1 & (msgId ^ LS_INVALID_MESSAGE_ID));
        }
};

/* 
   LsMessageHistory 
*/
typedef LsList<u_int32_t> LsMessageIdList;
typedef less<int> less_node_id;
class LsMessageHistory : public LsMap<int, u_int32_t> {
public:
        // isNewMessage, note: it saves this one in the history as well
        bool isNewMessage ( const LsMessage & msg ); 
};

class LsRetransmissionManager;
class LsRetransTimer : public TimerHandler {
public:
        LsRetransTimer() {}
        LsRetransTimer (LsRetransmissionManager *amp , int nbrId)
                : ackManagerPtr_(amp), neighborId_(nbrId) {}
        virtual void expire(Event *e);
protected:
        LsRetransmissionManager* ackManagerPtr_;
        int neighborId_;
};

struct LsIdSeq {
        u_int32_t msgId_;
        u_int32_t seq_;
        LsIdSeq() {}
        LsIdSeq(u_int32_t id, u_int32_t s) : msgId_(id), seq_(s) {}
};

/* LsUnackPeer 
   used in ackManager to keep record a peer who still haven't ack some of 
   its LSA or Topo packets
*/
struct LsUnackPeer {
        double rtxTimeout_; // time out value 
        LsRetransTimer timer_;
        u_int32_t tpmSeq_; // topo message Id

        LsMap<int, LsIdSeq> lsaMap_;

        // constructor
        LsUnackPeer() : tpmSeq_(LS_INVALID_MESSAGE_ID) {}
        LsUnackPeer(LsRetransmissionManager* amp, int nbrId, 
                    double timeout = LS_RTX_TIMEOUT) : 
                rtxTimeout_(timeout), timer_(amp, nbrId), 
                tpmSeq_(LS_INVALID_MESSAGE_ID) {}
};

/* 
   LsDelayMap
   store the estimated one-way total delay for eay neighbor, in second
*/
typedef LsMap< int, double > LsDelayMap; 

/* 
   LsRetransmissionManager -- handles retransmission and acknowledgement
*/
class LsRouting; 
class LsRetransmissionManager : public LsMap<int, LsUnackPeer> {
public:
        LsRetransmissionManager(LsRouting& lsr) : lsRouting_(lsr) {} 

        void initTimeout(LsDelayMap* delayMapPtr);
        void cancelTimer(int neighborId);

        // Called by LsRouting when a message is sent out 
        int messageOut(int peerId, const LsMessage& msg);
  
        // Called by LsRouting when an ack is received
        int ackIn(int peerId,  const LsMessage& ack);

        // Called by retransmit timer
        int resendMessages(int peerId);

private:
        // data
        LsRouting& lsRouting_;
};

inline void LsRetransTimer::expire(Event *e) 
{ 
        ackManagerPtr_->resendMessages(neighborId_); 
}
   
/* 
   LsNode -- represents the node environment interface 
   It serves as the interface between the Routing class and the actual 
   simulation enviroment 
   rtProtoLS will derive from LsNode as well as Agent
*/
class LsNode {
public:
        virtual bool sendMessage(int destId, u_int32_t msgId, 
                                  int msgsz = LS_DEFAULT_MESSAGE_SIZE) = 0;
        virtual void receiveMessage(int sender, u_int32_t msgId) = 0;
        // TODO , maybe not, use one type of message, that's it. 
        // All go to message center.
        // sendAck 
        // receiveAck
        virtual int getNodeId() = 0;
        virtual LsLinkStateList* getLinkStateListPtr()= 0; 
        virtual LsNodeIdList* getPeerIdListPtr() = 0;
        virtual LsDelayMap* getDelayMapPtr() = 0;
};

/* 
   LsRouting -- The implementation of the Link State Routing protocol
*/
class LsRouting {
public:
        static int msgSizes[ LS_MESSAGE_TYPES ];
        friend class LsRetransmissionManager;

        // constructor and distructor
        LsRouting() : myNodePtr_(NULL),  myNodeId_(LS_INVALID_NODE_ID), 
                peerIdListPtr_(NULL), linkStateListPtr_(NULL),
                routingTablePtr_(NULL),
                linkStateDatabase_(), lsaHistory_(), ackManager_(*this) {}
        ~LsRouting() {
                //delete pLinkStateDatabase;
                if (routingTablePtr_ != NULL)
                        delete routingTablePtr_;
        }

        bool init(LsNode* nodePtr);
        void computeRoutes() {
                if (routingTablePtr_ != NULL)
                        delete routingTablePtr_;
                routingTablePtr_ = _computeRoutes();
        }
        LsEqualPaths* lookup(int destId) {
                return (routingTablePtr_ == NULL) ? 
                        (LsEqualPaths *)NULL : 
                        routingTablePtr_->findPtr(destId);
        }

        // to propogate LSA, all Links, called by node and self
        bool sendLinkStates(bool buffer = false); 
        void linkStateChanged();
        void sendBufferedMessages() ;

        // called by node when messages arrive
        bool receiveMessage(int senderId , u_int32_t msgId);

private:
        // most of these pointers should have been references, 
        // except routing table
        LsNode * myNodePtr_; // where I am residing in
        int myNodeId_; // who am I
        LsNodeIdList* peerIdListPtr_; // my peers
        LsLinkStateList* linkStateListPtr_; // My links
        LsMessageCenter* messageCenterPtr_; // points to static messageCenter
        LsPaths* routingTablePtr_; // the routing table
        LsTopoMap linkStateDatabase_; // topology;
        LsMessageHistory lsaHistory_; // Remember what we've seen
        LsMessageHistory tpmHistory_; 
        LsRetransmissionManager ackManager_; // Handles ack and retransmission

        struct IdMsgPtr {
                int peerId_;
                const LsMessage* msgPtr_;
                IdMsgPtr() {};
                IdMsgPtr(int id, const LsMessage* p) :
                        peerId_(id), msgPtr_(p) {}
        };
        typedef LsList<IdMsgPtr> MessageBuffer;
        MessageBuffer messageBuffer_;

private:
        LsMessageCenter& msgctr() { return LsMessageCenter::instance(); }
        LsPaths* _computeRoutes();
        bool isUp(int neighborId);

        bool receiveAck (int neighborId, LsMessage* msgPtr) {
                ackManager_.ackIn(neighborId, *msgPtr);
                return true;
        }
        bool receiveLSA (int neighborId, LsMessage* msgPtr);
        bool receiveTopo(int neighborId, LsMessage* msgPtr);

        // send the entire topomap
        // don't worry, in simulation only the pointer is sent
        // in ospf, only the descrpition of it is sent first, 
        void sendTopo(int neighborId);
        void regenAndSend(int exception, int origin, 
                          const LsLinkStateList& lsl);
        bool sendAck(int nbrId, ls_message_type_t type, 
                     int originNodeIdAcked, u_int32_t originMsgIdAcked);
        void resendMessage(int neighborId, u_int32_t msgId, 
                            ls_message_type_t type) {
                myNodePtr_->sendMessage(neighborId, msgId, msgSizes[type]);
        }
        // just store the outgoing messages, and wait for cmd flushBuffer to 
        // actually send out 
        void bufferedSend (int peerId, const LsMessage* mp) {
                messageBuffer_.push_back(IdMsgPtr(peerId, mp));
        }
};

#endif // ns_ls_h

---