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  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]
Date:	Sun, 26 May 2013 00:03:04 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	timo.teras@....fi
Cc:	netdev@...r.kernel.org
Subject: Re: [PATCH RFC] net/ipv4: Use next hop exceptions also for input
 routes

From: Timo Teräs <timo.teras@....fi>
Date: Thu, 23 May 2013 16:15:46 +0300

> Commit d2d68ba9 (ipv4: Cache input routes in fib_info nexthops)
> assmued that "locally destined, and routed packets, never trigger
> PMTU events or redirects that will be processed by us".
> 
> However, it seems that tunnel devices do trigger PMTU events in certain
> cases. At least ip_gre, ip6_gre, sit, and ipip do use the inner flow's
> skb_dst(skb)->ops->update_pmtu to propage mtu information from the
> outer flows. These can cause the inner flow mtu to be decreased. If
> next hop exceptions are not consulted for pmtu, IP fragmentation will
> not be done properly for these routes.
> 
> It also seems that we really need to have the PMTU information always
> for netfilter TCPMSS' clamp-to-pmtu feature to work properly.
> 
> So for the time being, cache separate copies of input routes for
> each next hop exception.
> 
> Signed-off-by: Timo Teräs <timo.teras@....fi>

Thanks for working on this Timo, I am actively reviewing this change
and thinking about alternatives.
--
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