DupInitInCookieEchoed.seq - Duplicate INIT chunk is received in COOKIE-ECHOED state
To check that if INIT chunk is received in COOKIE-ECHOED state then the
endpoint should respond with an INIT-ACK using the same parameters it
sent in its original INIT chunk.
./DupInitInCookieEchoed.seq [-tooloption ...] -pkt ./DupInitInCookieEchoed.def
-tooloption : v6eval tool option
See Also: ../common/STD_PKT_COMMON.def
../common/SCTP_COMMON.def
Association not established between endpoint A and B. Also arrange the
data in endpoint B such that upper layers send Associate primitive to
startup an association with endpoint A.
Endpoint A Endpoint B ULP
(CLOSED) (CLOSED)
<----- Associate
<----------------- INIT
INIT-ACK ----------------->
<----------------- COOKIE-ECHO
INIT ----------------->
<----------------- INIT-ACK
COOKIE-ECHO ----------------->
<----------------- COOKIE-ACK
<----- Send
<----------------- DATA
SACK ----------------->
TEST DESCRIPTION:
1. Start normal association procedure by sending associate primitive
from ULP in endpoint B and from ULP in endpoint A at the same time.
Record the message sequence using a signal emulator.
2. Send INIT message to endpoint B after receiving COOKIE-ECHO message
to the endpoint B.
3. Check A: INIT-ACK message is sent in response to INIT message.
4. Check B: In the INIT-ACK message, verification tag field is set to
the peer's new tag value received in the duplicate INIT message.
5. Check C: In the INIT-ACK message, Init Tag is equal to the Init
Tag in the existing association.
6. Check D: Cookie, sent in the INIT-ACK message, is the newly generated
Cookie with the information in the duplicate INIT message with local
tie tag and peer tie tag equal to current verification tag and peer
verification tag.
None
RFC 4960
5.2.1. INIT Received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
This usually indicates an initialization collision, i.e., each
endpoint is attempting, at about the same time, to establish an
association with the other endpoint.
Upon receipt of an INIT in the COOKIE-WAIT state, an endpoint MUST
respond with an INIT ACK using the same parameters it sent in its
original INIT chunk (including its Initiate Tag, unchanged). When
responding, the endpoint MUST send the INIT ACK back to the same
address that the original INIT (sent by this endpoint) was sent.
Upon receipt of an INIT in the COOKIE-ECHOED state, an endpoint MUST
respond with an INIT ACK using the same parameters it sent in its
original INIT chunk (including its Initiate Tag, unchanged), provided
that no NEW address has been added to the forming association. If
the INIT message indicates that a new address has been added to the
association, then the entire INIT MUST be discarded, and NO changes
should be made to the existing association. An ABORT SHOULD be sent
in response that MAY include the error 'Restart of an association
with new addresses'. The error SHOULD list the addresses that were
added to the restarting association.
When responding in either state (COOKIE-WAIT or COOKIE-ECHOED) with
an INIT ACK, the original parameters are combined with those from the
newly received INIT chunk. The endpoint shall also generate a State
Cookie with the INIT ACK. The endpoint uses the parameters sent in
its INIT to calculate the State Cookie.
After that, the endpoint MUST NOT change its state, the T1-init timer
shall be left running, and the corresponding TCB MUST NOT be
destroyed. The normal procedures for handling State Cookies when a
TCB exists will resolve the duplicate INITs to a single association.
For an endpoint that is in the COOKIE-ECHOED state, it MUST populate
its Tie-Tags within both the association TCB and inside the State
Cookie (see Section 5.2.2 for a description of the Tie-Tags).