drcl.inet.protocol.ospf
Class OSPF_LSA_Header

java.lang.Object
  |
  +--drcl.inet.protocol.ospf.OSPF_LSA_Header

public class OSPF_LSA_Header

extends java.lang.Object

OSPF LSA Header (fixed length = 20 byte) ref: sec. 12.1 & A.4.1 contains fields: ls_age(2), options(1), type(1), LS_ID(4), Adv_router(4), LS_seqno(4), checksum(2), length(2) Ref: RFC 2328 sec. 12 Remark: ls_age, options, type, checksum, length in RFC is defined unsigned type Here we use signed type for simplicity. Besides, we replace struct in_addr with long

Author:

Wei-peng Chen

See Also:

OSPF_LSA

Field Summary

protected int	birth birth: the time when genarating the LSA although 'birth' is not defined in the header, it is necessary to record in the lsa.
protected static int	INITIAL_SEQUENCE_NUMBER
protected int	installed
protected int	lsh_advtr specify router ID of the LSA's originator
protected int	lsh_age Age of the LSA: An instance of age MaxAge is always accepted as most recent; Otherwise, if the ages differ by more than MaxAgeDiff, the instance having the smaller age is accepted as most recent.(sec.
protected int	lsh_id In type 1, link state type always represents router ID ref: sec 12.1.4 table 16
protected int	lsh_seqnum increase one when the router send one new LSA
protected int	lsh_type
protected static int	MAX_SEQUENCE_NUMBER
protected static int	OSPF_LSA_HEADER_SIZE

Method Summary

protected int	check_lsh_type() Check the correctness of the header type
java.lang.Object	clone()
protected void	duplicate(java.lang.Object source_) duplicate the OSPF_LSA_Header
protected int	ospf_age_current(int now_) get current age of the LSA
protected void	ospf_age_update_to_send(int transdelay, int now_) update age field of lsa_hdr, add InfTransDelay, when sending out the packet over the interface
protected static int	ospf_lsa_issame(OSPF_LSA_Header lsh1, OSPF_LSA_Header lsh2) test LSAs identity
protected int	size() return the header size
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

OSPF_LSA_HEADER_SIZE

protected static final int OSPF_LSA_HEADER_SIZE

lsh_age

protected int lsh_age

Age of the LSA: An instance of age MaxAge is always accepted as most recent; Otherwise, if the ages differ by more than MaxAgeDiff, the instance having the smaller age is accepted as most recent.(sec. 12.1.1)

lsh_type

protected int lsh_type

lsh_id

protected int lsh_id

In type 1, link state type always represents router ID ref: sec 12.1.4 table 16

lsh_advtr

protected int lsh_advtr

specify router ID of the LSA's originator

INITIAL_SEQUENCE_NUMBER

protected static final int INITIAL_SEQUENCE_NUMBER

MAX_SEQUENCE_NUMBER

protected static final int MAX_SEQUENCE_NUMBER

lsh_seqnum

protected int lsh_seqnum

increase one when the router send one new LSA

birth

protected int birth

birth: the time when genarating the LSA although 'birth' is not defined in the header, it is necessary to record in the lsa. Record the birth time of this lsa. => also can record the time that this lsa has stayed

installed

protected int installed

Method Detail

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

clone

public java.lang.Object clone()

Overrides:

clone in class java.lang.Object

duplicate

protected void duplicate(java.lang.Object source_)

duplicate the OSPF_LSA_Header

size

protected int size()

return the header size

check_lsh_type

protected int check_lsh_type()

Check the correctness of the header type

ospf_age_update_to_send

protected void ospf_age_update_to_send(int transdelay,
                                       int now_)

update age field of lsa_hdr, add InfTransDelay, when sending out the packet over the interface

ospf_age_current

protected int ospf_age_current(int now_)

get current age of the LSA

ospf_lsa_issame

protected static int ospf_lsa_issame(OSPF_LSA_Header lsh1,
                                     OSPF_LSA_Header lsh2)

test LSAs identity