netdev - Re: [PATCH net-next] ipv4: use l4 hash for locally generated multipath flows

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: <1446144211.6254.2.camel@edumazet-glaptop2.roam.corp.google.com>
Date:	Thu, 29 Oct 2015 11:43:31 -0700
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Paolo Abeni <pabeni@...hat.com>
Cc:	Peter Nørlund <pch@...bogen.com>,
	netdev@...r.kernel.org, "David S. Miller" <davem@...emloft.net>,
	Alexey Kuznetsov <kuznet@....inr.ac.ru>,
	James Morris <jmorris@...ei.org>,
	Hideaki YOSHIFUJI <yoshfuji@...ux-ipv6.org>,
	Patrick McHardy <kaber@...sh.net>
Subject: Re: [PATCH net-next] ipv4: use l4 hash for locally generated
 multipath flows

On Thu, 2015-10-29 at 17:52 +0100, Paolo Abeni wrote:
> On Thu, 2015-10-29 at 08:28 -0700, Eric Dumazet wrote:
> > On Thu, 2015-10-29 at 16:00 +0100, Paolo Abeni wrote:
> > 
> > > This patch do not add dissection code: it use the information provided
> > > by the available flowi4 structure. Moreover the skb is not available on
> > > the calling site (in __ip_route_output_key_hash) and pushing it all the
> > > way will require a lot of intrusive changes. Do you think it's the
> > > better option ?
> > 
> > If skb is provided, then we could use its information.
> 
> I see your point, but providing an skb to __ip_route_output_key_hash()
> is not very viable: it has a lot of indirect callers which are
> problematic, i.e.:
> 
> __ip_route_output_key()
> ip_route_output_flow()
> inet_csk_route_req()
> tcp_v4_send_synack()  <- skb available here, but created using dst
> information.
> 

I never said it was trivial.

I said : "If skb is provided, then we can use its l4hash"

If not, then sure, a flow-based hash fallback is better than nothing.


--
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