netdev - Re: [bpf-next PATCH v2 08/18] bpf: sk_msg program helper bpf_sk_msg_pull

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: <20180315.144210.1170859529847416311.davem@davemloft.net>
Date:   Thu, 15 Mar 2018 14:42:10 -0400 (EDT)
From:   David Miller <davem@...emloft.net>
To:     john.fastabend@...il.com
Cc:     ast@...nel.org, daniel@...earbox.net, davejwatson@...com,
        netdev@...r.kernel.org
Subject: Re: [bpf-next PATCH v2 08/18] bpf: sk_msg program helper
 bpf_sk_msg_pull_data

From: John Fastabend <john.fastabend@...il.com>
Date: Mon, 12 Mar 2018 12:23:45 -0700

> Currently, if a bpf sk msg program is run the program
> can only parse data that the (start,end) pointers already
> consumed. For sendmsg hooks this is likely the first
> scatterlist element. For sendpage this will be the range
> (0,0) because the data is shared with userspace and by
> default we want to avoid allowing userspace to modify
> data while (or after) BPF verdict is being decided.
> 
> To support pulling in additional bytes for parsing use
> a new helper bpf_sk_msg_pull(start, end, flags) which
> works similar to cls tc logic. This helper will attempt
> to point the data start pointer at 'start' bytes offest
> into msg and data end pointer at 'end' bytes offset into
> message.
 ...
> Signed-off-by: John Fastabend <john.fastabend@...il.com>

Yeah this looks really nice.

Acked-by: David S. Miller <davem@...emloft.net>