netdev - Re: [RFC bpf-next 0/5] Extend SOCKMAP to store listening sockets

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: <20191024161208.nh2hgsgtscmmfl7w@ast-mbp.dhcp.thefacebook.com>
Date:   Thu, 24 Oct 2019 09:12:09 -0700
From:   Alexei Starovoitov <alexei.starovoitov@...il.com>
To:     Jakub Sitnicki <jakub@...udflare.com>
Cc:     bpf@...r.kernel.org, John Fastabend <john.fastabend@...il.com>,
        Martin KaFai Lau <kafai@...com>, netdev@...r.kernel.org,
        kernel-team@...udflare.com
Subject: Re: [RFC bpf-next 0/5] Extend SOCKMAP to store listening sockets

On Tue, Oct 22, 2019 at 01:37:25PM +0200, Jakub Sitnicki wrote:
> This patch set is a follow up on a suggestion from LPC '19 discussions to
> make SOCKMAP (or a new map type derived from it) a generic type for storing
> established as well as listening sockets.
> 
> We found ourselves in need of a map type that keeps references to listening
> sockets when working on making the socket lookup programmable, aka BPF
> inet_lookup [1].  Initially we repurposed REUSEPORT_SOCKARRAY but found it
> problematic to extend due to being tightly coupled with reuseport
> logic (see slides [2]). So we've turned our attention to SOCKMAP instead.
> 
> As it turns out the changes needed to make SOCKMAP suitable for storing
> listening sockets are self-contained and have use outside of programming
> the socket lookup. Hence this patch set.
> 
> With these patches SOCKMAP can be used in SK_REUSEPORT BPF programs as a
> drop-in replacement for REUSEPORT_SOCKARRAY for TCP. This can hopefully
> lead to code consolidation between the two map types in the future.
> 
> Having said that, the main intention here is to lay groundwork for using
> SOCKMAP in the next iteration of programmable socket lookup patches.
> 
> I'm looking for feedback if there's anything fundamentally wrong with
> extending SOCKMAP map type like this that I might have missed.

John, Martin,
comments?