From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamal Hadi Salim Date: Wed, 18 Dec 2013 14:06:12 +0000 Subject: Re: Send fail notifications Message-Id: <52B1ABD4.1060108@mojatatu.com> List-Id: References: <52B1AA25.3000700@mojatatu.com> In-Reply-To: <52B1AA25.3000700@mojatatu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sctp@vger.kernel.org A little more info: - When i have MTU > 16K, no problem, 1 notification makes it through with an EOR and proper info EOR. - ssf_flags are always zero (thats one other place that may have carried such extra info) - kernel 3.12.0 (with other non-sctp patches) cheers, jamal On 12/18/13 08:59, Jamal Hadi Salim wrote: > > Lets say between server and client i have an MTU of 4K. > I send 16K with partial reliability setting. > If the data gets through the receiver sees (I think > SCTP_PARTIAL_DELIVERY_POINT may change this behavior but it probably > defaults to MTU): > > Msg1, 4k, !EOR > Msg2, 4k, !EOR > Msg3, 4k, !EOR > Msg4, 4k, EOR > > OTOH, at sender if the send fails because PR timeout on some data > chunk occurs i receive from the kernel not 1 but 4 notifications. > Msg1, 4k, Notification(send failed, ssf_length=4k), EOR > Msg2, 4k, Notification(send failed, ssf_length=4k), EOR > Msg3, 4k, Notification(send failed, ssf_length=4k), EOR > Msg4, 4k, Notification(send failed, ssf_length=4k), EOR > .... some last message here to account for notification overhead .... > > I was expecting only the last one to have an EOR or least the > ssf_length to be telling me there's more than 4K. Stoopid question: > Is there some other field I should be looking at? > > The only way i could tell the 5 notifications are from the same > original message is when i provide a sinfo_context at sendmsg() time. > > > cheers, > jamal