[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20180111150853.GT32305@orbyte.nwl.cc>
Date: Thu, 11 Jan 2018 16:08:53 +0100
From: Phil Sutter <phil@....cc>
To: David Ahern <dsahern@...il.com>, Chris Mi <chrism@...lanox.com>,
netdev@...r.kernel.org, gerlitz.or@...il.com,
stephen@...workplumber.org, marcelo.leitner@...il.com
Subject: Re: [patch iproute2 v8 1/2] lib/libnetlink: Add functions
rtnl_talk_msg and rtnl_talk_iov
On Wed, Jan 10, 2018 at 09:12:45PM +0100, Phil Sutter wrote:
> On Wed, Jan 10, 2018 at 12:20:36PM -0700, David Ahern wrote:
> [...]
> > 2. I am using a batch file with drop filters:
> >
> > filter add dev eth2 ingress protocol ip pref 273 flower dst_ip
> > 192.168.253.0/16 action drop
> >
> > and for each command tc is trying to dlopen m_drop.so:
> >
> > open("/usr/lib/tc//m_drop.so", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such
> > file or directory)
>
> [...]
>
> > Can you look at a follow on patch (not part of this set) to cache status
> > of dlopen attempts?
>
> IMHO the logic used in get_action_kind() for gact is the culprit here:
> After trying to dlopen m_drop.so, it dlopens m_gact.so although it is
> present already. (Unless I missed something.)
Not quite, m_gact.c is statically compiled in and there is logic around
dlopen(NULL, ...) to prevent calling it twice.
> I guess the better (and easier) fix would be to create some more struct
> action_util instances in m_gact.c for the primitives it supports so that
> the lookup in action_list succeeds for consecutive uses. Note that
> parse_gact() even supports this already.
Sadly, this doesn't fly: If a lookup for action 'drop' is successful,
that value is set as TCA_ACT_KIND and the kernel doesn't know about it.
I came up with an alternative solution, what do you think about attached
patch?
Thanks, Phil
View attachment "dlopen_gact.diff" of type "text/plain" (1650 bytes)
Powered by blists - more mailing lists