netdev - Re: setsockopt()

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 07 Jul 2008 16:27:14 -0700
From:	Rick Jones <rick.jones2@...com>
To:	David Miller <davem@...emloft.net>
CC:	aglo@...i.umich.edu, shemminger@...tta.com, netdev@...r.kernel.org,
	rees@...ch.edu, bfields@...ldses.org
Subject: Re: setsockopt()

David Miller wrote:
> We need 2x, in order to have a full window during recovery.
> 
> There was a measurement bug found a few months ago when the
> google folks were probing in this area, which was fixed
> by John Heffner.  Most of which had to deal with TSO subtleties.
> 
> --------------------
> commit 246eb2af060fc32650f07203c02bdc0456ad76c7
> Author: John Heffner <johnwheffner@...il.com>
> Date:   Tue Apr 29 03:13:52 2008 -0700
> 
>     tcp: Limit cwnd growth when deferring for GSO
>     
>     This fixes inappropriately large cwnd growth on sender-limited flows
>     when GSO is enabled, limiting cwnd growth to 64k.
>     
>     Signed-off-by: John Heffner <johnwheffner@...il.com>
>     Signed-off-by: David S. Miller <davem@...emloft.net>
> 
> commit ce447eb91409225f8a488f6b7b2a1bdf7b2d884f
> Author: John Heffner <johnwheffner@...il.com>
> Date:   Tue Apr 29 03:13:02 2008 -0700
> 
>     tcp: Allow send-limited cwnd to grow up to max_burst when gso disabled
>     
>     This changes the logic in tcp_is_cwnd_limited() so that cwnd may grow
>     up to tcp_max_burst() even when sk_can_gso() is false, or when
>     sysctl_tcp_tso_win_divisor != 0.
>     
>     Signed-off-by: John Heffner <johnwheffner@...il.com>
>     Signed-off-by: David S. Miller <davem@...emloft.net>
> --------------------


I'll try my tests again with newer kernels since I'm not 100% certain I 
was trying with those commits in place.

> Setting TCP socket buffer via setsockopt() is always wrong.

Does that apply equally to SO_SNDBUF and SO_RCVBUF?

rick jones
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html