From mboxrd@z Thu Jan 1 00:00:00 1970 From: zhuyj Subject: SCTP_PEER_ADDR_CHANGE Notification over UNCONFIRMED path Date: Fri, 15 Aug 2014 16:49:46 +0800 Message-ID: <53EDC9AA.9080500@gmail.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------030205070701000605070006" To: LKML , netdev , Vlad Yasevich , tuexen@fh-muenster.de, khandelwal.deepak.1987@gmail.com, "Tao, Yue" , Alexandre Dietsch , "David S. Miller" , zhuyj Return-path: Received: from mail-pa0-f43.google.com ([209.85.220.43]:62933 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751272AbaHOIuB (ORCPT ); Fri, 15 Aug 2014 04:50:01 -0400 Sender: netdev-owner@vger.kernel.org List-ID: This is a multi-part message in MIME format. --------------030205070701000605070006 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Hi, Vlad && DEEPAK && Michael && David From Michael && DEEPAK " lxr SCTP implementation, doesn't transit the path state to INACTIVE, if it was never confirmed. this leads to SCTP_PEER_ADDRESS_CHANGE notification after each failed probe from this time. Is there any specific reason to have same notification to SCTP User with each probe in RTO time period ? 806 case SCTP_TRANSPORT_DOWN: 807 /* If the transport was never confirmed, do not transition it 808 * to inactive state. Also, release the cached route since 809 * there may be a better route next time. 810 */ 811 if (transport->state != SCTP_UNCONFIRMED) 812 transport->state = SCTP_INACTIVE; http://lxr.free-electrons.com/source/net/sctp/associola.c#L806 we checked RFC and here it is mentioned as Path Verification Section(5.4) of RFC 4960 http://tools.ietf.org/html/rfc4960 In each RTO, a probe may be sent on an active UNCONFIRMED path in an attempt to move it to the CONFIRMED state. If during this probing the path becomes inactive, this rate is lowered to the normal HEARTBEAT rate. At the expiration of the RTO timer, the error counter of any path that was probed but not CONFIRMED is incremented by one and subjected to path failure detection, as defined in Section 8.2 . When probing UNCONFIRMED addresses, however, the association overall error counter is not incremented Does this mean that in attempt to move a UNCONFIRMED path to CONFIRMED State, the path can become INACTIVE, when transport error counter reaches to path_max_retrans counter ? I would say that the path stays UNCONFIRMED. I would also only expect a SCTP_PEER_ADDRESS_CHANGE notification when a path state changes, not on every try. " I made a patch to disable sending SCTP_PEER_ADDRESS_CHANGE notification every try. Now the patch is in the attachment. Please check it. Zhu Yanjun --------------030205070701000605070006 Content-Type: text/x-patch; name="0001-sctp-not-send-SCTP_PEER_ADDR_CHANGE-notifications-wi.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename*0="0001-sctp-not-send-SCTP_PEER_ADDR_CHANGE-notifications-wi.pa"; filename*1="tch" >>From 78027ced63911229092c345dbac47c385259fe35 Mon Sep 17 00:00:00 2001 From: Zhu Yanjun Date: Fri, 15 Aug 2014 16:32:51 +0800 Subject: [PATCH 1/1] sctp: not send SCTP_PEER_ADDR_CHANGE notifications with failed probe When a failed probe comes along UNCONFIRMED path, it is not necessary to send SCTP_PEER_ADDR_CHANGE notification. Reported-by: DEEPAK KHANDELWAL Suggested-by: Vlad Yasevich Suggested-by: Michael Tuexen Signed-off-by: Zhu Yanjun --- net/sctp/associola.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/sctp/associola.c b/net/sctp/associola.c index 9de23a2..2e23f6b 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -813,6 +813,7 @@ void sctp_assoc_control_transport(struct sctp_association *asoc, else { dst_release(transport->dst); transport->dst = NULL; + ulp_notify = false; } spc_state = SCTP_ADDR_UNREACHABLE; -- 1.9.1 --------------030205070701000605070006--