Fixing "Slipping in the window" before 4.11-release
silby at silby.com
Tue Jan 4 05:02:50 GMT 2005
On Mon, 3 Jan 2005, Charles Swiger wrote:
> Are you relying on the IPID or the connection tuple of
> srcIP+srcPort+destIP+destPort to identify the SYN packet as being associated
> with an already established connection?
>> This means that SYN packets left of the window will no longer receive an
>> ACK, and SYN packets in the window will no longer reset the connection. In
>> all states other than ESTABLISHED, SYN packets are handled as they were
>> before, in case there's some edge case where that could happen.
> This seems to be a reasonable improvement: the stack shouldn't be ACK'ing
> data outside of a valid connection window to begin with.
I spoke inaccurately above. We trim the ACK to the left edge of our
window, then ACK that value. So, it *shouldn't* affect the state of the
connection, but it will cause us to flood ACKs.
More comments coming, see upcoming reply to Don...
Mike "Silby" Silbersack
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