On Thu, Nov 08, 2018 at 03:44:10PM +0800, Hangbin Liu wrote:
> On Fri, Oct 26, 2018 at 10:30:54AM +0800, Hangbin Liu wrote:
> > Currently we only set mc_qrv to sysctl_mld_qrv when interface up. If we
> > change sysctl_mld_qrv after interface up, it will has no effect.
> >
> > Fix it by assigning latest sysctl_mld_qrv to idev mc_qrv when join new
> > group.
> >
> > Reported-by: Ying Xu <yi...@redhat.com>
> > Signed-off-by: Hangbin Liu <liuhang...@gmail.com>
>
> Hi David,
>
> Any comments for this patch?
> > ---
> > net/ipv6/mcast.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
> > index dbab62e..bed4890 100644
> > --- a/net/ipv6/mcast.c
> > +++ b/net/ipv6/mcast.c
> > @@ -680,6 +680,7 @@ static void igmp6_group_added(struct ifmcaddr6 *mc)
> > if (!(dev->flags & IFF_UP) || (mc->mca_flags & MAF_NOREPORT))
> > return;
> >
> > + mc->idev->mc_qrv = sysctl_mld_qrv;
> > if (mld_in_v1_mode(mc->idev)) {
> > igmp6_join_group(mc);
> > return;
Hi David,
Sorry for the late reply. Today I find your reply in
https://patchwork.ozlabs.org/patch/989422/, but I could not find your reply
in my local mailbox, even on gmail web side. I can receive other kernel
mails correctly, which is weird...I will check it later.
For your question:
> Why isn't mld_update_qrv() taking care of this?
mld_update_qrv() is used for processing recieved mldv2 query message. This
patch is to init new sysctl_mld_qrv for new joined groups, which haven't
received any mld query message. e.g.
- ipv6_mc_up() - ipv6_mc_reset() set idev->mc_qrv to default sysctl_mld_qrv,
which is 2
- Join group A with qrv = 2
- user set sysctl_mld_qrv to 3
- Join group B with qrv = 2 <- Here the new group should set qrv to 3 as
user updated sysctl_mld_qrv. This is the
issue this patch want to fix
- Recived MLDv2 query message
- Group A, B update new qrv via mld_update_qrv()
> At a minimum, you must make your change take MLD_QRV_DEFAULT etc.
> into account like mld_update_qrv() does.
We should not init mc_qrv to min(MLD_QRV_DEFAULT, sysctl_mld_qrv), or
user will never be able to set mc_qrv greater than 2.
Thanks
Hangbin
