Re: [PATCH mptcp-next 2/7] mptcp: add clear_flags in pm_netlink

[Geliang Tang <geliang.tang@suse.com>]

On Mon, Jan 10, 2022 at 12:38:14PM +0100, Paolo Abeni wrote:
> Hello,
> 
> On Mon, 2022-01-10 at 11:30 +0800, Geliang Tang wrote:
> > Splite set_flags() into two parts, set_flags() and clear_flags(), make it
> > easy to add new flags to set or clear.
> > 
> > This patch added a new PM command MPTCP_PM_CMD_CLEAR_FLAGS, and a new
> > function mptcp_nl_cmd_clear_flags().
> > 
> > Signed-off-by: Geliang Tang <geliang.tang@suse.com>
> > ---
> >  include/uapi/linux/mptcp.h |  1 +
> >  net/mptcp/pm_netlink.c     | 36 ++++++++++++++++++++++++++----------
> >  2 files changed, 27 insertions(+), 10 deletions(-)
> > 
> > diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h
> > index f106a3941cdf..1ca9b13c2ed0 100644
> > --- a/include/uapi/linux/mptcp.h
> > +++ b/include/uapi/linux/mptcp.h
> > @@ -92,6 +92,7 @@ enum {
> >  	MPTCP_PM_CMD_SET_LIMITS,
> >  	MPTCP_PM_CMD_GET_LIMITS,
> >  	MPTCP_PM_CMD_SET_FLAGS,
> > +	MPTCP_PM_CMD_CLEAR_FLAGS,
> >  
> >  	__MPTCP_PM_CMD_AFTER_LAST
> >  };
> 
> I'm unsure if this has already been discussed in some mtg I missed. If
> so, I'm sorry for the late feedback :(
> 
> Looking at the existing netlink interfaces, I *think* the preferred way
> of handling this would be adding instead a couple of MPTCP address
> flags:
> 
> 	MPTCP_PM_ADDR_FLAG_NOBACKUP,
> 	MPTCP_PM_ADDR_FLAG_NOFULLMESH
> 
> As e.g. IFA_F_NOPREFIXROUTE, IFA_F_NODAD,...
> 
> The above should require a similar amount of code and will make it
> clear that we can't/wan't to flip the SUBFLOW or SIGNAL flags.
> 
> WDYT?

Agree, will update in v2.

Thanks,
-Geliang

> 
> Thanks!
> 
> Paolo
>