Re: [PATCH net-next v2 0/2] support SO_PRIORITY cmsg

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

Anna Nyiri wrote:
> Ido Schimmel <idosch@idosch.org> ezt írta (időpont: 2024. nov. 3., V, 17:25):
> >
> > On Sat, Nov 02, 2024 at 01:51:34PM +0100, Anna Emese Nyiri wrote:
> > > The changes introduce a new helper function,
> > > `sk_set_prio_allowed`, which centralizes the logic for validating
> > > priority settings. This series adds support for the `SO_PRIORITY`
> > > control message, allowing user-space applications to set socket
> > > priority via control messages (cmsg).
> > >
> > > Patch Overview:
> > > Patch 1/2: Introduces `sk_set_prio_allowed` helper function.
> > > Patch 2/2: Implements support for setting `SO_PRIORITY` via control
> > > messages.
> > >
> > > v2:
> > > - Suggested by Willem de Bruijn <willemdebruijn.kernel@gmail.com>
> > >   introduce "sk_set_prio_allowed" helper to check priority setting
> > >   capability
> > > - drop new fields and change sockcm_cookie::priority from "char" to
> > >   "u32" to match with sk_buff::priority
> > > - cork->tos value check before priority setting
> > >   moved from __ip_make_skb() to ip_setup_cork()
> > > - rebased on net-next
> > >
> > > v1:
> > > https://lore.kernel.org/all/20241029144142.31382-1-annaemesenyiri@gmail.com/
> > >
> > > Anna Emese Nyiri (2):
> > >   Introduce sk_set_prio_allowed helper function
> > >   support SO_PRIORITY cmsg
> > >
> > >  include/net/inet_sock.h |  2 +-
> > >  include/net/ip.h        |  3 ++-
> > >  include/net/sock.h      |  4 +++-
> > >  net/can/raw.c           |  2 +-
> > >  net/core/sock.c         | 19 ++++++++++++++++---
> > >  net/ipv4/ip_output.c    |  7 +++++--
> > >  net/ipv4/raw.c          |  2 +-
> > >  net/ipv6/ip6_output.c   |  3 ++-
> > >  net/ipv6/raw.c          |  2 +-
> > >  net/packet/af_packet.c  |  2 +-
> > >  10 files changed, 33 insertions(+), 13 deletions(-)
> >
> > Please consider adding a selftest for this feature. Willem already
> > extended tools/testing/selftests/net/cmsg_sender.c so that it could be
> > used to set SO_PRIORITY via setsockopt. You can extend it to set
> > SO_PRIORITY via cmsg and then use it in a test like
> > tools/testing/selftests/net/cmsg_so_mark.sh is doing for SO_MARK.
> 
> Of course, I will send the test. However, I would first like to
> clarify which option I should assign in cmsg_sender for setting
> priority via cmsg. The -P option is already used for setting priority
> with setsockopt(), and -p is used to specify the protocol.

Thanks for adding test coverage.

If all the Ps are taken, use Q. It's a rare letter, and happens to be
the next. In the end, whatever is available.