Subject: Re: [PATCH RFC] Per route TCP options

From: Eric Dumazet <[email-masked]>
Date: Tue, 20 Oct 2009 17:44:59 +0200

Gilad Ben-Yossef a écrit :
> Turn the global sysctls allowing disabling of TCP SACK, DSCAK,
> time stamp and window scale into per route entry feature options,
> laying the ground to future removal of the relevant global sysctls.
> 
> You really only want to disable SACK, DSACK, time stamp or window
> scale if you've got a piece of broken networking equipment somewhere 
> as a stop gap until you can bring a big enough hammer to deal with
> the broken network equipment. It doesn't make sense to "punish" the
> entire connections going through the machine to destinations not 
> related to the broken equipment.
> 
> This is doubly true when you're dealing with network containers
> used to isolate several virtual domains.
> 
> Per route options implemented in free bits in the features route
> entry property, which in some cases were reserved by name for these
> options, so this does not inflate any structure and I expect that
> when the apropriate global sysctls will be removed the overall code
> base will be smaller.
> 
> Tested on x86 using Qemu/KVM.  
> 
> Will send the matching patch to iproute2 if/when this is ACKed or
> if someone wants to test this.
> 
> Patchset based on original work by Ori Finkelman and Yoni Amit 
> from ComSleep Ltd.
> 
> Gilad Ben-Yossef (8):
>   Only parse time stamp TCP option in time wait sock
>   Allow tcp_parse_options to consult dst entry
>   Infrastructure for querying route entry features
>   Add the no SACK route option feature
>   Allow disabling TCP timestamp options per route
>   Allow to turn off TCP window scale opt per route
>   Allow disabling of DSACK TCP option per route
>   Document future removal of sysctl_tcp_* options
> 

Interesting... But you should give numbers to your patches so that we know their order

You could also do the ECN part for consistency (ie RTAX_FEATURE_ECN -> RTAX_FEATURE_NO_ECN)

And please post iproute2 patches as well :)

Thanks