buglwIP - A Lightweight TCP/IP stack - Bugs: bug #28098, Nagle can prevent fast retransmit...

 
 

You are not allowed to post comments on this tracker with your current authentication level.

bug #28098: Nagle can prevent fast retransmit from sending segment

Submitted by:  Harry Bryson <hbryson>
Submitted on:  Thu 26 Nov 2009 11:37:54 AM UTC  
 
Category: TCPSeverity: 3 - Normal
Item Group: Faulty BehaviourStatus: Fixed
Privacy: PublicAssigned to: Simon Goldschmidt <goldsimon>
Open/Closed: ClosedPlanned Release: None
lwIP version: 1.3.1

Thu 26 Nov 2009 04:44:27 PM UTC, comment #2:

The fix was rather simple: tcp_do_output_nagle() must return TRUE if pcb->flags has TF_INFR set.

Fixed, thanks for reporting.

Simon Goldschmidt <goldsimon>
Project AdministratorIn charge of this item.
Thu 26 Nov 2009 03:07:20 PM UTC, comment #1:

Hmm, this is indeed a problem that should be fixed for 1.3.2 as the nagle on pcb-level is quite new...

Simon Goldschmidt <goldsimon>
Project AdministratorIn charge of this item.
Thu 26 Nov 2009 11:37:54 AM UTC, original submission:

If fast retransmit (tcp_rexmit() from tcp_receive()) attempts to output a segment, the segment can be blocked by Nagle algorithm (if it matches the appropriate criteria). It should not be.

If a slow retransmission occurs after the above event(tcp_rexmit_rto()), the previous "stuck" segment is queued behind all its subsequent segments in the unsent queue. When the unsent queue is output, the "stuck" segment will again be prevented by Nagle from getting transmitted.

If no sunsequent data is enqueued to TCP (e.g. TCP PCB is "full"), the above condition is persistent and the connection will stall and eventually fail.

Harry Bryson <hbryson>

 

No files currently attached

 

Depends on the following items: None found

Items that depend on this one: None found

 

Carbon-Copy List
  • -unavailable- added by goldsimon (Posted a comment)
  • -unavailable- added by hbryson (Submitted the item)
  •  

    Do you think this task is very important?
    If so, you can click here to add your encouragement to it.
    This task has 0 encouragements so far.

    Only logged-in users can vote.

     

    Please enter the title of George Orwell's famous dystopian book (it's a date):

     

     

    Follow 3 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Thu 26 Nov 2009 04:44:27 PM UTCgoldsimonOpen/ClosedOpen=>Closed
      Assigned toNone=>goldsimon
      StatusNone=>Fixed

    Back to the top


    Powered by Savane 3.1-cleanup1