Re: [PATCH 0/3] PROTO_CMSG_DATA_ONLY for Datagram (UDP)

[Victor Stewart <v@nametag.social>]

On Sat, Dec 12, 2020 at 5:07 PM Jens Axboe <axboe@kernel.dk> wrote:
>
> On 12/12/20 8:31 AM, Victor Stewart wrote:
> > RE our conversation on the "[RFC 0/1] whitelisting UDP GSO and GRO
> > cmsgs" thread...
> >
> > https://lore.kernel.org/io-uring/CAM1kxwi5m6i8hrtkw7nZYoziPTD-Wp03+fcsUwh3CuSc=81kUQ@mail.gmail.com/
> >
> > here are the patches we discussed.
> >
> > Victor Stewart (3):
> >    net/socket.c: add PROTO_CMSG_DATA_ONLY to __sys_sendmsg_sock
> >    net/ipv4/af_inet.c: add PROTO_CMSG_DATA_ONLY to inet_dgram_ops
> >    net/ipv6/af_inet6.c: add PROTO_CMSG_DATA_ONLY to inet6_dgram_ops
> >
> >    net/ipv4/af_inet.c
> >      |   1 +
> >    net/ipv6/af_inet6.c
> >     |   1 +
> >    net/socket.c
> >        |   8 +-
> >    3 files changed, 7 insertions(+), 3 deletions(-)
>
> Changes look fine to me, but a few comments:
>
> - I'd order 1/3 as 3/3, that ordering makes more sense as at that point it
>   could actually be used.

right that makes sense.

>
> - For adding it to af_inet/af_inet6, you should write a better commit message
>   on the reasoning for the change. Right now it just describes what the
>   patch does (which is obvious from the change), not WHY it's done. Really
>   goes for current 1/3 as well, commit messages need to be better in
>   general.
>

okay thanks Jens. i would have reiterated the intention but assumed it
were implicit given I linked the initial conversation about enabling
UDP_SEGMENT (GSO) and UDP_GRO through io_uring.

> I'd also CC Jann Horn on the series, he's the one that found an issue there
> in the past and also acked the previous change on doing PROTO_CMSG_DATA_ONLY.

I CCed him on this reply. Soheil at the end of the first exchange
thread said he audited the UDP paths and believed this to be safe.

how/should I resubmit the patch with a proper intention explanation in
the meta and reorder the patches? my first patch and all lol.

>
> --
> Jens Axboe
>