From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Daniel Borkmann <daniel@iogearbox.net>
Cc: John Fastabend <john.fastabend@gmail.com>,
davem@davemloft.net, ast@kernel.org, davejwatson@fb.com,
netdev@vger.kernel.org
Subject: Re: [bpf-next PATCH v2 05/18] bpf: create tcp_bpf_ulp allowing BPF to monitor socket TX/RX data
Date: Thu, 15 Mar 2018 15:20:12 -0700 [thread overview]
Message-ID: <20180315222010.kq5hcjsl33d3smho@ast-mbp> (raw)
In-Reply-To: <31bf7017-7456-1637-3a99-9630fc4d7009@iogearbox.net>
On Thu, Mar 15, 2018 at 11:17:12PM +0100, Daniel Borkmann wrote:
> On 03/15/2018 10:59 PM, Alexei Starovoitov wrote:
> > On Mon, Mar 12, 2018 at 12:23:29PM -0700, John Fastabend wrote:
> >>
> >> +/* User return codes for SK_MSG prog type. */
> >> +enum sk_msg_action {
> >> + SK_MSG_DROP = 0,
> >> + SK_MSG_PASS,
> >> +};
> >
> > do we really need new enum here?
> > It's the same as 'enum sk_action' and SK_DROP == SK_MSG_DROP
> > and there will be only drop/pass in both enums.
> > Also I don't see where these two new SK_MSG_* are used...
> >
> >> +
> >> +/* user accessible metadata for SK_MSG packet hook, new fields must
> >> + * be added to the end of this structure
> >> + */
> >> +struct sk_msg_md {
> >> + __u32 data;
> >> + __u32 data_end;
> >> +};
> >
> > I think it's time for me to ask for forgiveness :)
>
> :-)
>
> > I used __u32 for data and data_end only because all other fields
> > in __sk_buff were __u32 at the time and I couldn't easily figure out
> > how to teach verifier to recognize 8-byte rewrites.
> > Unfortunately my mistake stuck and was copied over into xdp.
> > Since this is new struct let's do it right and add
> > 'void *data, *data_end' here,
> > since bpf prog will use them as 'void *' pointers.
> > There are no compat issues here, since bpf is always 64-bit.
>
> But at least offset-wise when you do the ctx rewrite this would then
> be a bit more tricky when you have 64 bit kernel with 32 bit user
> space since void * members are in each cases at different offset. So
> unless I'm missing something, this still should either be __u32 or
> __u64 instead of void *, no?
there is no 32-bit user space. these structs are seen by bpf progs only
and bpf is 64-bit only too.
unless I'm missing your point.
next prev parent reply other threads:[~2018-03-15 22:20 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-12 19:23 [bpf-next PATCH v2 00/18] bpf,sockmap: sendmsg/sendfile ULP John Fastabend
2018-03-12 19:23 ` [bpf-next PATCH v2 01/18] sock: make static tls function alloc_sg generic sock helper John Fastabend
2018-03-12 19:23 ` [bpf-next PATCH v2 02/18] sockmap: convert refcnt to an atomic refcnt John Fastabend
2018-03-12 19:23 ` [bpf-next PATCH v2 03/18] net: do_tcp_sendpages flag to avoid SKBTX_SHARED_FRAG John Fastabend
2018-03-15 18:40 ` David Miller
2018-03-12 19:23 ` [bpf-next PATCH v2 04/18] net: generalize sk_alloc_sg to work with scatterlist rings John Fastabend
2018-03-12 19:23 ` [bpf-next PATCH v2 05/18] bpf: create tcp_bpf_ulp allowing BPF to monitor socket TX/RX data John Fastabend
2018-03-15 18:41 ` David Miller
2018-03-15 21:59 ` Alexei Starovoitov
2018-03-15 22:08 ` John Fastabend
2018-03-15 22:17 ` Daniel Borkmann
2018-03-15 22:20 ` Alexei Starovoitov [this message]
2018-03-15 22:55 ` Daniel Borkmann
2018-03-15 23:06 ` Alexei Starovoitov
2018-03-16 0:37 ` Daniel Borkmann
2018-03-16 16:47 ` John Fastabend
2018-03-12 19:23 ` [bpf-next PATCH v2 06/18] bpf: sockmap, add bpf_msg_apply_bytes() helper John Fastabend
2018-03-15 18:41 ` David Miller
2018-03-15 20:32 ` Daniel Borkmann
2018-03-15 22:02 ` John Fastabend
2018-03-15 21:45 ` Alexei Starovoitov
2018-03-15 21:59 ` John Fastabend
2018-03-12 19:23 ` [bpf-next PATCH v2 07/18] bpf: sockmap, add msg_cork_bytes() helper John Fastabend
2018-03-15 18:41 ` David Miller
2018-03-12 19:23 ` [bpf-next PATCH v2 08/18] bpf: sk_msg program helper bpf_sk_msg_pull_data John Fastabend
2018-03-15 18:42 ` David Miller
2018-03-15 20:25 ` Daniel Borkmann
2018-03-12 19:23 ` [bpf-next PATCH v2 09/18] bpf: add map tests for BPF_PROG_TYPE_SK_MSG John Fastabend
2018-03-15 18:42 ` David Miller
2018-03-12 19:23 ` [bpf-next PATCH v2 10/18] bpf: add verifier " John Fastabend
2018-03-15 18:42 ` David Miller
2018-03-12 19:24 ` [bpf-next PATCH v2 11/18] bpf: sockmap sample, add option to attach SK_MSG program John Fastabend
2018-03-15 18:42 ` David Miller
2018-03-12 19:24 ` [bpf-next PATCH v2 12/18] bpf: sockmap sample, add sendfile test John Fastabend
2018-03-15 18:42 ` David Miller
2018-03-12 19:24 ` [bpf-next PATCH v2 13/18] bpf: sockmap sample, add data verification option John Fastabend
2018-03-15 18:42 ` David Miller
2018-03-12 19:24 ` [bpf-next PATCH v2 14/18] bpf: sockmap, add sample option to test apply_bytes helper John Fastabend
2018-03-15 18:42 ` David Miller
2018-03-12 19:24 ` [bpf-next PATCH v2 15/18] bpf: sockmap sample support for bpf_msg_cork_bytes() John Fastabend
2018-03-15 18:42 ` David Miller
2018-03-15 20:15 ` Alexei Starovoitov
2018-03-15 22:04 ` John Fastabend
2018-03-12 19:24 ` [bpf-next PATCH v2 16/18] bpf: sockmap add SK_DROP tests John Fastabend
2018-03-15 18:43 ` David Miller
2018-03-12 19:24 ` [bpf-next PATCH v2 17/18] bpf: sockmap sample test for bpf_msg_pull_data John Fastabend
2018-03-15 18:43 ` David Miller
2018-03-12 19:24 ` [bpf-next PATCH v2 18/18] bpf: sockmap test script John Fastabend
2018-03-15 18:43 ` David Miller
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