Re: [PATCH net] sctp: do not update transport pathmtu if SPP_PMTUD_ENABLE is not set

[Xin Long <lucien.xin@gmail.com>]

On Wed, Jul 21, 2021 at 2:42 PM Marcelo Ricardo Leitner
<marcelo.leitner@gmail.com> wrote:
>
> On Wed, Jul 21, 2021 at 12:08:25PM -0400, Xin Long wrote:
> > Currently, in sctp_packet_config(), sctp_transport_pmtu_check() is
> > called to update transport pathmtu with dst's mtu when dst's mtu
> > has been changed by non sctp stack like xfrm.
> >
> > However, this should only happen when SPP_PMTUD_ENABLE is set, no
> > matter where dst's mtu changed. This patch is to fix by checking
> > SPP_PMTUD_ENABLE flag before calling sctp_transport_pmtu_check().
> >
> > Thanks Jacek for reporting and looking into this issue.
> >
> > Fixes: 69fec325a643 ('Revert "sctp: remove sctp_transport_pmtu_check"')
> > Reported-by: Jacek Szafraniec <jacek.szafraniec@nokia.com>
> > Tested-by: Jacek Szafraniec <jacek.szafraniec@nokia.com>
> > Signed-off-by: Xin Long <lucien.xin@gmail.com>
> > ---
> >  net/sctp/output.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/net/sctp/output.c b/net/sctp/output.c
> > index 9032ce60d50e..8d5708dd2a1f 100644
> > --- a/net/sctp/output.c
> > +++ b/net/sctp/output.c
> > @@ -104,8 +104,8 @@ void sctp_packet_config(struct sctp_packet *packet, __u32 vtag,
> >               if (asoc->param_flags & SPP_PMTUD_ENABLE)
> >                       sctp_assoc_sync_pmtu(asoc);
> >       } else if (!sctp_transport_pl_enabled(tp) &&
> > -                !sctp_transport_pmtu_check(tp)) {
> > -             if (asoc->param_flags & SPP_PMTUD_ENABLE)
> > +                asoc->param_flags & SPP_PMTUD_ENABLE)
>
> Lacks a '{' here at the end of the line.
ah, right, sorry, reposted.

>
> Other than that:
> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
>
> (please add it on the v2)
>
> > +             if (!sctp_transport_pmtu_check(tp))
> >                       sctp_assoc_sync_pmtu(asoc);
> >       }
> >
> > --
> > 2.27.0
> >