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]
Message-ID: <87bpe825z2.fsf@basil.nowhere.org>
Date:	Sun, 28 Mar 2010 10:41:37 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	David Miller <davem@...emloft.net>
Cc:	gdt@....id.au, netdev@...r.kernel.org
Subject: Re: UDP path MTU discovery

David Miller <davem@...emloft.net> writes:

> From: Glen Turner <gdt@....id.au>
> Date: Fri, 26 Mar 2010 10:32:31 +1030
>
>> This differs from TCP, where it is the kernel -- and not
>> the application -- which organises retransmission. On
>> receiving a ICMP Fragmentation Needed the kernel can
>> immediately re-probe the path MTU wiht no waiting for
>> an exponential timer to expire.
>
> So the argument is, the kernel TCP does retransmission smart,
> userspace UDP apps do it stupidly, so let's turn off the feature
> instead of fixing userspace.
>
> Right?
>
> Sorry, fix this correctly in the user apps.  Putting the
> blame on UDP path MTU discovery is placing it in the
> wrong spot.

It means though that all IPv6 UDP applications essentially have
to implement path mtu discovery support (which is non trivial) 

Will be likely a long time until they're all fixed.

Seems like a big hole not considered by the IPv6 designers?

-Andi
-- 
ak@...ux.intel.com -- Speaking for myself only.
--
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

Powered by blists - more mailing lists