From: Alexei Starovoitov <ast@plumgrid•com>
To: Daniel Borkmann <daniel@iogearbox•net>,
Hannes Frederic Sowa <hannes@stressinduktion•org>,
stephen@networkplumber•org
Cc: jiri@resnulli•us, tgraf@suug•ch, netdev@vger•kernel.org,
Jamal Hadi Salim <jhs@mojatatu•com>
Subject: Re: [PATCH iproute2 -next] tc, bpf: finalize eBPF support for cls and act front-end
Date: Thu, 02 Apr 2015 09:14:07 -0700 [thread overview]
Message-ID: <551D6ACF.3090101@plumgrid.com> (raw)
In-Reply-To: <551D3156.9030407@iogearbox.net>
On 4/2/2015 5:08 AM, Daniel Borkmann wrote:
> On 04/02/2015 01:30 PM, Hannes Frederic Sowa wrote:
>>> ... perhaps such a built-in fake device for retrieving bpf map fds
>>> might be interesting, e.g. exec 4<>/dev/bpf/<obj-file>/<map-name> if
>>> that has been given to bash?
>>>
>>> Anyway, I think to have some utility for shell scripts, as you
>>> suggest, certainly sounds interesting!
>>
>> All file descriptors will be inherited by exec as long as the O_CLOEXEC
>> flag wasn't specified on them. So you can retrieve the fds via af_unix
>> and just exec a new shell. The file descriptors will stay open and you
>> can pass the numbers of the fds via environment. This wouldn't need
>> changes to bash or kernel.
>
> Okay, I will give it a try. Thanks!
I think even if it's little awkward to do it in user space, it's better
than adding stuff to kernel. This /dev/bpf/obj-file/map-name or sysfs
might start hitting scalability issues when we try to load thousands
of bpf programs.
next prev parent reply other threads:[~2015-04-02 16:14 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-30 22:35 [PATCH iproute2 -next] tc, bpf: finalize eBPF support for cls and act front-end Daniel Borkmann
2015-04-01 5:16 ` Alexei Starovoitov
2015-04-01 8:48 ` Daniel Borkmann
2015-04-01 12:36 ` Jamal Hadi Salim
2015-04-01 14:13 ` Daniel Borkmann
2015-04-01 22:30 ` Thomas Graf
2015-04-08 11:58 ` Jamal Hadi Salim
2015-04-02 0:13 ` Hannes Frederic Sowa
2015-04-02 0:24 ` Daniel Borkmann
2015-04-02 0:29 ` Hannes Frederic Sowa
2015-04-02 10:19 ` Daniel Borkmann
2015-04-02 11:30 ` Hannes Frederic Sowa
2015-04-02 12:08 ` Daniel Borkmann
2015-04-02 16:14 ` Alexei Starovoitov [this message]
2015-04-02 18:38 ` Daniel Borkmann
2015-04-02 12:10 ` Thomas Graf
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