[lwip-devel] [task #7896] Support zero-copy drivers

[Joel Cunningham]

Follow-up Comment #11, task #7896 (project lwip):

I've actually encountered the TCP retransmission issue with another embedded
stack that supported asynchronous zero-copy TX.  That stack had a behavior
where if a fast retransmit happened, it didn't restart the original RTO timer.
This made it possible that if a fast retransmit happened within close
succession to the original RTO timing out, we'd end up performing two
retransmits of the same packet

Taking a quick look at LwIP, I think the same thing could happen. pcb->rtime
is only reset during an actual RTO via the slow timer and not during
tcp_rexmit_fast().

    _______________________________________________________

Reply to this item at:

  <http://savannah.nongnu.org/task/?7896>

_______________________________________________
  Message sent via/by Savannah
  http://savannah.nongnu.org/