SSF.OS.OSPFv2
Class Neighbor

java.lang.Object
  |
  +--SSF.OS.OSPFv2.Neighbor

public class Neighbor

extends java.lang.Object

The class Neighbor represents a conversation between its interface owner and the neighboring interface. All Information to build and maintain this conversation is represented in it. It is identified either by the neighboring router's OSPF Router ID or by its Neighbor ip address.

Nested Class Summary

class	Neighbor.FloodingTimer /* A multiple shot Timer for flooding LSAs in LS Update Packets.
class	Neighbor.InactivityTimer /* The Inactivity Timer for this Neighbor class.
class	Neighbor.LastRecDDPacket A class in which the important information of the last received DD packet are recorded.
class	Neighbor.RetransmissionTimer /* The Retransmission Timer for this Neighbor class.

Field Summary

static int	ATTEMPT Indicates that the current state of neighbor conversation is ATTEMPT
DD_Packet	dataDescContent A Database Description Packet.
java.util.Vector	dbSummList The complete list of LSAs that make up the area link-state database, at the moment the neighbor goes into Database Exchange state (EXCHANGE).
int	DDSeqNum The DD Sequence Number of the DD packet that is currently being sent to the neighbor
Neighbor.InactivityTimer	deadTimer Single shot timer whose firing indicates that no Hello Packet has been seen from this Neighbor recently.
static int	DOWN Indicates that the current state of neighbor conversation is DOWN
static int	EXCHANGE Indicates that the current state of neighbor conversation is EXCHANGE
static int	EXSTART Indicates that the current state of neighbor conversation is EXSTART
Neighbor.FloodingTimer	floodTimer Multiple shot timer whose firing indicates that LSAs should be reflooded.
static int	FULL Indicates that the current state of neighbor conversation is FULL
static int	INIT Indicates that the current state of neighbor conversation is INIT
boolean	isMaster To know who is master in the master/slave relationship during Database Exchage.
Neighbor.LastRecDDPacket	lastDDPacket Another data structure for keeping information of the last received DD packet.
static int	LOADING Indicates that the current state of neighbor conversation is LOADING
LS_RequestPacket	lsReqContent A Link State Request Packet.
java.util.Hashtable	lsReqList The list of LSAs that need to be received from this neighbor in order to synchronize the two neighbor's link-state database.
java.util.HashMap	lsRetransList The list of LSAs that have been flooded but not yet acknowledged on this adjacency.
int	neighborBDR The neighbor's IDEA of the backup designated router.
int	neighborDR The neighbor's IDEA of the designated router.
int	neighborID The router ID of the Neighbor Router.
int	neighborIPAddr The IP address of the neighboring router's interface to the attached network.
java.lang.String	neighborNHI The NHI address prefix of the neighboring router.
int	neighborPrio The Router priority of the neighboring router.
boolean[]	options The optional OSPF capabilities supported by the neighbor.
java.util.HashMap	pacingFloodList The list of LSAs that must be flooded out to this neighbor when the pacingTimer fires.
Neighbor.RetransmissionTimer	retransTimer Multiple shot timer whose firing indicates that a Database Description or Request Packet should be retransmitted.
int	state The functional level of the neighbor conversation
static int	TWOWAY Indicates that the current state of neighbor conversation is 2-WAY

Constructor Summary

Neighbor(OSPF myOSPF, AreaData myArea, Interface myInterface, int ipaddr)
Constructs an Neighbor.

Method Summary

void	adjOk() A decision must be made as to whether an adjacency should be established/maintained with the neighbor.
void	badLSReq() Called if a LS Request has been received for an LSA not contained in the database.
void	directAcknowledge(LSA ackLSA) Send a direct Acknowledgment for a particular LSA to the Neighbor.
void	exchange(Packet dataDescPkt) called if state is EXCHANGE.
void	exchangeDone() At this point, the router has sent and received an entire sequence of Database Description Packets.
java.util.Vector	fillAndSendUpdate(java.util.Vector requests) Fill an LS Update Packet with requested LSAs and send it to the Neighbor.
void	fillDDPacketWithHeaders() fill the global DD Packet dataDescContent with as many headers from the database summary list as possible.
void	fillRequestPacket() fill the global LS Request Packet lsReqContent with the keys of as many LSAs from the link state request list as possible.
java.lang.String	getStrFromState(int status) Converts the integer value of state in a more readable format.
boolean	hasKnownLSType(LSA testLSA) Check whether testLSA has a known LS Type and return true if so, otherwise false.
void	initDBExchange() initializes the Database Exchange between two Neighbors
void	loadingDone() Link State Updates have been received for all out-of-date portions of the database.
void	negotiation(Packet dataDescPkt) called when a DD Packet is received while state was EXSTART, or state turned to EXSTART.
void	negotiationDone(boolean neighborIsMaster, java.util.Vector payload) At this point Master/Slave relationship is definitly established.
void	oneWayHelloRec(Packet helloPkt, int sourceIP) Have seen a Neighbor, but the Neighbor doesn't know about me
void	processFloodedUpdate(Packet lsUpdPkt) LS Update Packet has been received while state was FULL.
void	processLSAck(Packet lsAckPkt) When an LS Ack Packet was received, this method is called by the Interface which is adjacent to this Neighbor.
void	processLSAs(java.util.Vector ddPayload) Process the LSA Headers received in the last received Database Description Packet.
void	processLSRequest(Packet lsReqPkt) examine the requested LSAs, locate them in the database and send them in LS Update Packets to the Neighbor.
void	processLSUpdate(Packet lsUpdPkt) LS Update Packet has been received while state was EXCHANGE or LOADING.
boolean	processReceivedLSA(LSA recLSA) This method is called by either "processLSUpdate" or "processFloodedUpdate".
protected void	removeRequest(java.lang.String removeKey) Remove a key from the LS Request List.
void	reset() reset the Neighbor Data Structure to the initial values.
void	sendPacket(ProtocolMessage content) Sends an OSPF Packet (database description or ls request) to the Neighbor this Structure was built for.
void	seqNumMismatch(java.lang.String reason) Actions to be performed, if the received DD Packet has a) an unexpected DD sequence number or b) unexpectedly the Initialize bit set or c) an Options field differing from the last Options field received.
boolean	startFlooding() The Interface's pacingTimer schedules the first flooding of an LSA.
void	subseqTreatment(Packet dataDescPkt) called by the Interface Data Structure if a DD Packet was received and the relationship with the neighbor is in state LOADING or FULL.
void	twoWayHelloRec(Packet helloPkt, int sourceIP) Determine whether an adjacency should be established with the neighbor
void	twoWayReceived(Packet dataDescPkt) called when a DD Packet is received while state was INIT.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DOWN

public static final int DOWN

Indicates that the current state of neighbor conversation is DOWN

See Also:

Constant Field Values

ATTEMPT

public static final int ATTEMPT

Indicates that the current state of neighbor conversation is ATTEMPT

See Also:

Constant Field Values

INIT

public static final int INIT

Indicates that the current state of neighbor conversation is INIT

See Also:

Constant Field Values

TWOWAY

public static final int TWOWAY

Indicates that the current state of neighbor conversation is 2-WAY

See Also:

Constant Field Values

EXSTART

public static final int EXSTART

Indicates that the current state of neighbor conversation is EXSTART

See Also:

Constant Field Values

EXCHANGE

public static final int EXCHANGE

Indicates that the current state of neighbor conversation is EXCHANGE

See Also:

Constant Field Values

LOADING

public static final int LOADING

Indicates that the current state of neighbor conversation is LOADING

See Also:

Constant Field Values

FULL

public static final int FULL

Indicates that the current state of neighbor conversation is FULL

See Also:

Constant Field Values

state

public int state

The functional level of the neighbor conversation

isMaster

public boolean isMaster

To know who is master in the master/slave relationship during Database Exchage. false means neighbor is slave, true means neighbor is master.

DDSeqNum

public int DDSeqNum

The DD Sequence Number of the DD packet that is currently being sent to the neighbor

lastDDPacket

public Neighbor.LastRecDDPacket lastDDPacket

Another data structure for keeping information of the last received DD packet.

neighborPrio

public int neighborPrio

The Router priority of the neighboring router.

neighborID

public int neighborID

The router ID of the Neighbor Router.

neighborNHI

public java.lang.String neighborNHI

The NHI address prefix of the neighboring router.

neighborIPAddr

public int neighborIPAddr

The IP address of the neighboring router's interface to the attached network.

options

public boolean[] options

The optional OSPF capabilities supported by the neighbor.

neighborDR

public int neighborDR

The neighbor's IDEA of the designated router.

neighborBDR

public int neighborBDR

The neighbor's IDEA of the backup designated router.

lsRetransList

public java.util.HashMap lsRetransList

The list of LSAs that have been flooded but not yet acknowledged on this adjacency. It is implemented as HashMap because it should be easy to replace old instances of LSAs by new ones.

dbSummList

public java.util.Vector dbSummList

The complete list of LSAs that make up the area link-state database, at the moment the neighbor goes into Database Exchange state (EXCHANGE). It is implemented as Vector because all LSAs stored in it are unique at every time.

lsReqList

public java.util.Hashtable lsReqList

The list of LSAs that need to be received from this neighbor in order to synchronize the two neighbor's link-state database.

pacingFloodList

public java.util.HashMap pacingFloodList

The list of LSAs that must be flooded out to this neighbor when the pacingTimer fires. When this happened they are transferred to the lsRetransList.

dataDescContent

public DD_Packet dataDescContent

A Database Description Packet. Used, to exchange LS Database informations with the Neighbor when both became adjacent. It saves the last sent DD Packet.

lsReqContent

public LS_RequestPacket lsReqContent

A Link State Request Packet. Used to request more recent LSAs from the Neighbor when state is EXCHANGE, LOADING or FULL. It saves the last sent LS Request Packet.

deadTimer

public Neighbor.InactivityTimer deadTimer

Single shot timer whose firing indicates that no Hello Packet has been seen from this Neighbor recently.

retransTimer

public Neighbor.RetransmissionTimer retransTimer

Multiple shot timer whose firing indicates that a Database Description or Request Packet should be retransmitted.

floodTimer

public Neighbor.FloodingTimer floodTimer

Multiple shot timer whose firing indicates that LSAs should be reflooded.

Constructor Detail

Neighbor

public Neighbor(OSPF myOSPF,
                AreaData myArea,
                Interface myInterface,
                int ipaddr)

Constructs an Neighbor.

Method Detail

reset

public void reset()

reset the Neighbor Data Structure to the initial values. This is part of the stop process of the OSPF Session.

oneWayHelloRec

public void oneWayHelloRec(Packet helloPkt,
                           int sourceIP)

Have seen a Neighbor, but the Neighbor doesn't know about me

twoWayHelloRec

public void twoWayHelloRec(Packet helloPkt,
                           int sourceIP)

Determine whether an adjacency should be established with the neighbor

twoWayReceived

public void twoWayReceived(Packet dataDescPkt)

called when a DD Packet is received while state was INIT.

negotiation

public void negotiation(Packet dataDescPkt)

called when a DD Packet is received while state was EXSTART, or state turned to EXSTART.

negotiationDone

public void negotiationDone(boolean neighborIsMaster,
                            java.util.Vector payload)

At this point Master/Slave relationship is definitly established. DD sequence numbers have been exchanged. This is the begin of sending/receiving of DD Packets.

processLSAs

public void processLSAs(java.util.Vector ddPayload)

Process the LSA Headers received in the last received Database Description Packet.

Parameters:

ddPayload - A Vector holding the LSA Headers to process.

fillDDPacketWithHeaders

public void fillDDPacketWithHeaders()

fill the global DD Packet dataDescContent with as many headers from the database summary list as possible. Remove every header filled in the Packet from the list. The amount of headers in the DD Packet is restricted by the OSPF MTU value.

seqNumMismatch

public void seqNumMismatch(java.lang.String reason)

Actions to be performed, if the received DD Packet has a) an unexpected DD sequence number or b) unexpectedly the Initialize bit set or c) an Options field differing from the last Options field received.

badLSReq

public void badLSReq()

Called if a LS Request has been received for an LSA not contained in the database. This indicates an error in the Database Exchange process. Actions to be performed are the same as in seqNumMismatch. In addition, stop the possibly activated retrans- mission timer.

exchange

public void exchange(Packet dataDescPkt)

called if state is EXCHANGE. This method is executed every time a DD Packets arrives sent by the Neighbor. When the last Packet arrives, it transfers the state into LOADING or FULL

exchangeDone

public void exchangeDone()

At this point, the router has sent and received an entire sequence of Database Description Packets. Now it must be determined whether the new state is FULL, or Link State Request Packets have to be send.

subseqTreatment

public void subseqTreatment(Packet dataDescPkt)

called by the Interface Data Structure if a DD Packet was received and the relationship with the neighbor is in state LOADING or FULL. The only DD Packets received should be duplicates.

adjOk

public void adjOk()

A decision must be made as to whether an adjacency should be established/maintained with the neighbor.

fillRequestPacket

public void fillRequestPacket()

fill the global LS Request Packet lsReqContent with the keys of as many LSAs from the link state request list as possible. The amount of keys in the LS Request Packet is restricted by the OSPF MTU value.

fillAndSendUpdate

public java.util.Vector fillAndSendUpdate(java.util.Vector requests)
                                   throws ProtocolException

Fill an LS Update Packet with requested LSAs and send it to the Neighbor. If there are more LSAs requested than could sent by a single LS Update Packet, return the rest of the requests to handle in a Vector. Else return an empty Vector.

ProtocolException

processLSRequest

public void processLSRequest(Packet lsReqPkt)

examine the requested LSAs, locate them in the database and send them in LS Update Packets to the Neighbor.

processLSUpdate

public void processLSUpdate(Packet lsUpdPkt)

LS Update Packet has been received while state was EXCHANGE or LOADING. Examine the received LSAs, check whether they were requested or not and process them accordingly. Therefore use method "processReceivedLSA" for further treatment.

Parameters:

lsUpdPkt - an LS Update Packet received while Neighbor state was EXCHANGE or LOADING.

removeRequest

protected void removeRequest(java.lang.String removeKey)

Remove a key from the LS Request List. If there is an LS Request Packet ready to send or the Packet is waiting for updates it requested and it holds this key, then remove it from the packets content too.

Parameters:

removeKey - A String representing the key which shall be removed.

processReceivedLSA

public boolean processReceivedLSA(LSA recLSA)
                           throws ProtocolException

This method is called by either "processLSUpdate" or "processFloodedUpdate". It gets recLSA from a received LS Update Packet and processes it as decribed in chapter 13 on page 143-146 in RFC 2328. The method returns "true" if recLSA should be removed from the LS Retransmission List in the case it has been placed there before, otherwise "false".

Parameters:

recLSA - LSA which was received in an LS Update Packet.

Returns:

boolean indicating whether recLSA should be removed from LS Retransmission List or not.

Throws:

ProtocolException - thrown if a Bad LS Request is triggered.

startFlooding

public boolean startFlooding()

The Interface's pacingTimer schedules the first flooding of an LSA. This method groups together these LSAs and sends out one LS Update Packet. If there are more LSAs that must be flooded out than fitting in a single packet, it returns true otherwise false.

Returns:

boolean value indicating wether the pacingTimer must be started again due to LSAs left for flooding out, or not.

hasKnownLSType

public boolean hasKnownLSType(LSA testLSA)

Check whether testLSA has a known LS Type and return true if so, otherwise false. Known LS Types are: Router-LSA, Network-LSA, Summary-Network-LSA, Summary-ASBR-LSA and AS-External-LSA.

processFloodedUpdate

public void processFloodedUpdate(Packet lsUpdPkt)

LS Update Packet has been received while state was FULL.

loadingDone

public void loadingDone()

Link State Updates have been received for all out-of-date portions of the database.

sendPacket

public void sendPacket(ProtocolMessage content)

Sends an OSPF Packet (database description or ls request) to the Neighbor this Structure was built for. This method only send the Packet! The parameter content must be set appropriately before.

initDBExchange

public void initDBExchange()

initializes the Database Exchange between two Neighbors

getStrFromState

public java.lang.String getStrFromState(int status)

Converts the integer value of state in a more readable format. This is only used for debuging purposes.

directAcknowledge

public void directAcknowledge(LSA ackLSA)

Send a direct Acknowledgment for a particular LSA to the Neighbor.

processLSAck

public void processLSAck(Packet lsAckPkt)

When an LS Ack Packet was received, this method is called by the Interface which is adjacent to this Neighbor. It then processes the received Packet.