Can I block a connection or an association when using callback? about usrsctp HOT 1 CLOSED

The rwnd is something that is controlled by the actual SCTP implementation. You are
correct in that if a application stops reading (calling recv) then the implementation
will buffer up to the rwnd bytes of data (waiting for the user to read it) and then finally
start to send a rwnd of 0. From the time you stop calling recv() to the time it stops
would vary depending on how much data the peer was sending you since the peer
must fill the rwnd before the rwnd == 0 condition would occur.

The callback API has no way to stop since it has already performed the read for you and
is handing you the data.

In some past implementation’s of such an API I have heard where folks would have the
callback not include the data, but instead say “You have data to read” and then you would
have to do a recv() call to acquire the data. Since it was not implemented that way then
I don’t think you can do anything to stop the data with current mechanisms.

You could, of course, always create an application to application message that says “Stop please
don’t send me data”. As long as your peer honored that then you would not receive more..
That is probably your only choice with the callback API.

Best wishes

R
On Jul 22, 2015, at 7:33 AM, Jianfeng Zhang [email protected] wrote:

I want to prevent the peer from writing more data to this socket. According to RFC4960 I need to tell the peer that my rwnd is 0.
I can stop calling recv() when in non-callback mode. But when using a callback, I can't stop the calling of the callback. Are there any APIs can help?

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Randall Stewart
[email protected]
803-317-4952

from usrsctp.