netdev - Re: [PATCH net-next v5 2/3] bpf: Add new cgroup attach type to enable sock modifications

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: <d3359d0c-8995-d605-cd2d-f0558fdd0408@cumulusnetworks.com>
Date:   Tue, 29 Nov 2016 18:07:18 -0700
From:   David Ahern <dsa@...ulusnetworks.com>
To:     Alexei Starovoitov <alexei.starovoitov@...il.com>
Cc:     netdev@...r.kernel.org, daniel@...que.org, ast@...com,
        daniel@...earbox.net, maheshb@...gle.com, tgraf@...g.ch
Subject: Re: [PATCH net-next v5 2/3] bpf: Add new cgroup attach type to enable
 sock modifications

On 11/29/16 5:59 PM, Alexei Starovoitov wrote:
> On Tue, Nov 29, 2016 at 05:43:08PM -0700, David Ahern wrote:
>> On 11/29/16 1:01 PM, Alexei Starovoitov wrote:
>>> Could you also expose sk_protcol and sk_type as read only fields?
>>
>> Those are bitfields in struct sock, so can't use offsetof or sizeof. Any existing use cases that try to load a bitfield in a bpf that I can look at?
> 
> pkt_type, vlan are also bitfileds in skb. Please see convert_skb_access()
> There is a bit of ugliness due to __BIG_ENDIAN_BITFIELD though..
> 

Given the added complexity I'd prefer to defer this second use case to a follow on patch set. This one introduces the infra for sockets and I don't see anything needing to change with it to add the read of 3 more sock elements. Agree?