netdev - Re: Problem with semantics?

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <p737inzne6i.fsf@bingen.suse.de>
Date:	14 Aug 2007 02:38:13 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	Shay Goikhman <GOIKHMAN@...ibm.com>
Cc:	netdev@...r.kernel.org, davem@...emloft.net, mtk-manpages@....net
Subject: Re: Problem with semantics?

Shay Goikhman <GOIKHMAN@...ibm.com> writes:

> Dear Linux maintainers,
> 
>  I'm doing :
> 
>       setsockopt(s,  SO_RCVTIMEO, t1 );                  // set time-out
> t1 on socket while block receiving on it
>       select(,,, &fd_set_including(s), .., &errs, t2);      // block till
> receive or time-out  t 2 jointly on a set of sockets
> 
> Apparently, I could no find reference on the coupled behavior of the two
> above statements in Linux documentation.
> As I understand the blocking semantics, I would expect  that  if t1<t2 ,
> select should return after t1 with the descriptor 's' in 'errs' if 's' does
> not become readable in the t1 interval.
> 
> It is not so in life -- select ignores t1 altogether.
> 
> Do you have some enlightening knowledge on the matter?

RCVTIMEO only applies to recvmsg et.al., similar to SNDTIMEO only
apply to sendmsg etc. But select/poll only report events, they
do not actually send or receive by themselves.

Michael, perhaps you can clarify that in the manpages

-Andi
-
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