[gPXE-devel] [PULL] ipxe-sync

[Piotr Jaroszyński]

2010/7/6 Michael Brown <mcb30 at ipxe.org>:
> On Tuesday 06 Jul 2010 16:53:13 Piotr Jaroszyński wrote:
>> > This may also be part of the TCP performance improvements Guo-fu is
>> > working on. Holding off for now on this fix seems fine, though we
>> > should note it so we don't forget.
>>
>> Michael's fix breaks when the last data packet has a FIN flag (which
>> is always with my http server).
>
> I always see a clean termination.  What is breaking in your setup?  (Is your
> HTTP server sending a packet that contains both data and FIN?)

My server seems to be sending such a packet, yes.

tcpdump of the end conversation that doesn't end properly and my
server keeps retransmitting the FIN:

18:49:12.347272 IP saturn.secured.pl.http > 192.168.3.1.1024: Flags
[P.], ack 81, win 5792, options [nop,nop,TS val 2138249377 ecr 3399],
length 1448
18:49:12.347274 IP saturn.secured.pl.http > 192.168.3.1.1024: Flags
[FP.], seq 1048353:1048764, ack 81, win 5792, options [nop,nop,TS val
2138249377 ecr 3399], length 411
18:49:12.347280 IP 192.168.3.1.1024 > saturn.secured.pl.http: Flags
[P.], ack 1048353, win 4096, options [nop,nop,TS val 3400 ecr
2138249377], length 0
18:49:12.347290 IP 192.168.3.1.1024 > saturn.secured.pl.http: Flags
[FP.], seq 81, ack 1048764, win 4096, options [nop,nop,TS val 3400 ecr
2138249377], length 0
18:49:12.347443 IP saturn.secured.pl.http > 192.168.3.1.1024: Flags
[.], ack 82, win 5792, options [nop,nop,TS val 2138249378 ecr 3400],
length 0
18:49:12.548423 IP saturn.secured.pl.http > 192.168.3.1.1024: Flags
[FP.], seq 1048764, ack 82, win 5792, options [nop,nop,TS val
2138249579 ecr 3400], length 0
18:49:12.950402 IP saturn.secured.pl.http > 192.168.3.1.1024: Flags
[FP.], seq 1048764, ack 82, win 5792, options [nop,nop,TS val
2138249981 ecr 3400], length 0
18:49:13.754427 IP saturn.secured.pl.http > 192.168.3.1.1024: Flags
[FP.], seq 1048764, ack 82, win 5792, options [nop,nop,TS val
2138250785 ecr 3400], length 0

Same thing with the admittedly a bit hacky fix from GFT [1]:

18:48:00.363084 IP saturn.secured.pl.http > 192.168.3.1.1024: Flags
[P.], ack 81, win 5792, options [nop,nop,TS val 2138177393 ecr 3398],
length 1448
18:48:00.363085 IP saturn.secured.pl.http > 192.168.3.1.1024: Flags
[FP.], seq 1048353:1048764, ack 81, win 5792, options [nop,nop,TS val
2138177393 ecr 3398], length 411
18:48:00.363090 IP 192.168.3.1.1024 > saturn.secured.pl.http: Flags
[P.], ack 1046905, win 4096, options [nop,nop,TS val 3399 ecr
2138177393], length 0
18:48:00.363097 IP 192.168.3.1.1024 > saturn.secured.pl.http: Flags
[P.], ack 1048353, win 4096, options [nop,nop,TS val 3399 ecr
2138177393], length 0
18:48:00.363108 IP 192.168.3.1.1024 > saturn.secured.pl.http: Flags
[FP.], seq 81, ack 1048765, win 4096, options [nop,nop,TS val 3399 ecr
2138177393], length 0
18:48:00.363265 IP saturn.secured.pl.http > 192.168.3.1.1024: Flags
[.], ack 82, win 5792, options [nop,nop,TS val 2138177393 ecr 3399],
length 0


[1] - http://git.etherboot.org/?p=people/cooldavid/gpxe.git;a=commitdiff;h=59298752519b9c7474f5c8ce36c2c29d71a9ec92

-- 
Best Regards
Piotr Jaroszyński