linux-kernel - Re: [PATCH bpf-next v3 2/7] net: export inet_lookup_reuseport and inet6_lookup

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] [day] [month] [year] [list]

Message-ID: <e21aa61a-803b-bb82-d56e-2db0c839477b@iogearbox.net>
Date:   Tue, 27 Jun 2023 12:19:41 +0200
From:   Daniel Borkmann <daniel@...earbox.net>
To:     Lorenz Bauer <lmb@...valent.com>,
        Kuniyuki Iwashima <kuniyu@...zon.com>
Cc:     andrii@...nel.org, ast@...nel.org, bpf@...r.kernel.org,
        davem@...emloft.net, dsahern@...nel.org, edumazet@...gle.com,
        haoluo@...gle.com, hemanthmalla@...il.com, joe@...d.net.nz,
        john.fastabend@...il.com, jolsa@...nel.org, kpsingh@...nel.org,
        kuba@...nel.org, linux-kernel@...r.kernel.org,
        linux-kselftest@...r.kernel.org, martin.lau@...ux.dev,
        mykolal@...com, netdev@...r.kernel.org, pabeni@...hat.com,
        sdf@...gle.com, shuah@...nel.org, song@...nel.org,
        willemdebruijn.kernel@...il.com, yhs@...com
Subject: Re: [PATCH bpf-next v3 2/7] net: export inet_lookup_reuseport and
 inet6_lookup_reuseport

On 6/27/23 10:56 AM, Lorenz Bauer wrote:
> On Mon, Jun 26, 2023 at 6:33 PM Kuniyuki Iwashima <kuniyu@...zon.com> wrote:
>>
>> From: Lorenz Bauer <lmb@...valent.com>
>> Date: Mon, 26 Jun 2023 16:08:59 +0100
>>> Rename the existing reuseport helpers for IPv4 and IPv6 so that they
>>> can be invoked in the follow up commit. Export them so that DCCP which
>>> may be built as a module can access them.
>>
>> We need not export the functions unless there is a real user.
>>
>> I added a deprecation notice for DCCP recently, so I bet DCCP
>> will not get SO_REUSEPORT support.
>> https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=b144fcaf46d4
> 
> Misleading commit message, it turns out that ipv6 as a module also
> needs (the v6 functions at least) to be EXPORT_SYMBOL'd. That's
> because of some special shenanigans where inet6_hashtables.c is linked
> into vmlinux even when CONFIG_IPV6=m.
> 
> Also not sure how to work around this: DCCP may be deprecated but
> without the export a module build of it fails.

If it breaks the build, then we need to export it.