From mboxrd@z Thu Jan 1 00:00:00 1970 From: Flavio Leitner Subject: Re: [PATCH 1/2] ipv6: add sysctl_mld_qrv to configure query robustness variable Date: Mon, 1 Sep 2014 21:05:54 -0300 Message-ID: <20140902000554.GA7909@t520.home> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org To: Hannes Frederic Sowa Return-path: Received: from mx1.redhat.com ([209.132.183.28]:10280 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751965AbaIBAF7 (ORCPT ); Mon, 1 Sep 2014 20:05:59 -0400 Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Hi Hannes, On Mon, Sep 01, 2014 at 09:55:34PM +0200, Hannes Frederic Sowa wrote: > This patch adds a new sysctl_mld_qrv knob to configure the mldv1/v2 query > robustness variable. It specifies how many retransmit of unsolicited mld > retransmit should happen. Admins might want to tune this on lossy links. > > Also reset mld state on interface down/up, so we pick up new sysctl > settings during interface up event. > > IPv6 certification requests this knob to be available. > > I didn't make this knob netns specific, as it is mostly a setting in a > physical environment and should be per host. > > Cc: Flavio Leitner > Signed-off-by: Hannes Frederic Sowa > --- > v2) no changes to original version > > Documentation/networking/ip-sysctl.txt | 3 +++ > include/net/ipv6.h | 1 + > net/ipv6/mcast.c | 20 ++++++++++++-------- > net/ipv6/sysctl_net_ipv6.c | 10 ++++++++++ > 4 files changed, 26 insertions(+), 8 deletions(-) > > diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt > index 3cce8ea..b7fe844 100644 > --- a/Documentation/networking/ip-sysctl.txt > +++ b/Documentation/networking/ip-sysctl.txt > @@ -1152,6 +1152,9 @@ anycast_src_echo_reply - BOOLEAN > FALSE: disabled > Default: FALSE > > +mld_qrv - INTEGER > + Controls the MLD query robustness variable (see RFC3810 9.1). > + > IPv6 Fragmentation: > > ip6frag_high_thresh - INTEGER > diff --git a/include/net/ipv6.h b/include/net/ipv6.h > index a2db816..7e247e9 100644 > --- a/include/net/ipv6.h > +++ b/include/net/ipv6.h > @@ -121,6 +121,7 @@ struct frag_hdr { > > /* sysctls */ > extern int sysctl_mld_max_msf; > +extern int sysctl_mld_qrv; > > #define _DEVINC(net, statname, modifier, idev, field) \ > ({ \ > diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c > index 7088179..6efb0e5 100644 > --- a/net/ipv6/mcast.c > +++ b/net/ipv6/mcast.c > @@ -121,6 +121,7 @@ static int ip6_mc_leave_src(struct sock *sk, struct ipv6_mc_socklist *iml, > #define IPV6_MLD_MAX_MSF 64 > > int sysctl_mld_max_msf __read_mostly = IPV6_MLD_MAX_MSF; > +int sysctl_mld_qrv __read_mostly = MLD_QRV_DEFAULT; > > /* > * socket join on multicast group > @@ -1196,7 +1197,7 @@ static void mld_update_qrv(struct inet6_dev *idev, > if (mlh2->mld2q_qrv > 0) > idev->mc_qrv = mlh2->mld2q_qrv; > > - if (unlikely(idev->mc_qrv < 2)) { > + if (unlikely(idev->mc_qrv < MLD_QRV_DEFAULT)) { > net_warn_ratelimited("IPv6: MLD: clamping QRV from %u to %u!\n", > idev->mc_qrv, MLD_QRV_DEFAULT); > idev->mc_qrv = MLD_QRV_DEFAULT; You allow the sysctl to be 1, but here it is limited to 2? > @@ -2478,6 +2479,14 @@ void ipv6_mc_down(struct inet6_dev *idev) > mld_clear_delrec(idev); > } > > +static void ipv6_mc_reset(struct inet6_dev *idev) > +{ > + idev->mc_qrv = sysctl_mld_qrv; > + idev->mc_qi = MLD_QI_DEFAULT; > + idev->mc_qri = MLD_QRI_DEFAULT; > + idev->mc_v1_seen = 0; > + idev->mc_maxdelay = unsolicited_report_interval(idev); > +} > > /* Device going up */ > > @@ -2488,6 +2497,7 @@ void ipv6_mc_up(struct inet6_dev *idev) > /* Install multicast list, except for all-nodes (already installed) */ > > read_lock_bh(&idev->lock); > + ipv6_mc_reset(idev); ok, up and down the interface to get the sysctl value applied. > for (i = idev->mc_list; i; i = i->next) > igmp6_group_added(i); > read_unlock_bh(&idev->lock); > @@ -2508,13 +2518,7 @@ void ipv6_mc_init_dev(struct inet6_dev *idev) > (unsigned long)idev); > setup_timer(&idev->mc_dad_timer, mld_dad_timer_expire, > (unsigned long)idev); > - > - idev->mc_qrv = MLD_QRV_DEFAULT; > - idev->mc_qi = MLD_QI_DEFAULT; > - idev->mc_qri = MLD_QRI_DEFAULT; > - > - idev->mc_maxdelay = unsolicited_report_interval(idev); > - idev->mc_v1_seen = 0; > + ipv6_mc_reset(idev); looks good to me. > write_unlock_bh(&idev->lock); > } > > diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c > index 0c56c93..c5c10fa 100644 > --- a/net/ipv6/sysctl_net_ipv6.c > +++ b/net/ipv6/sysctl_net_ipv6.c > @@ -16,6 +16,8 @@ > #include > #include > > +static int one = 1; > + Although that can be reused later for other purposes, it's nice to have a comment telling where that value came from. Since you have defined MLD_QRV_DEFAULT, it helps. Still I didn't know about rfc6636#section-4.5, so I'd appreciate if you include that info either in ip-sysctl.txt or close to MLD_QRV_DEFAULT. E.g.: /* See RFC3810 9.1 and rfc6636 4.5 */ +int sysctl_mld_qrv __read_mostly = MLD_QRV_DEFAULT; Actually, maybe that int could be something not specific to ipv6 because I believe there are more users of the same thing. That's ok, just a comment and it's not part of this patch. > static struct ctl_table ipv6_table_template[] = { > { > .procname = "bindv6only", > @@ -63,6 +65,14 @@ static struct ctl_table ipv6_rotable[] = { > .mode = 0644, > .proc_handler = proc_dointvec > }, > + { > + .procname = "mld_qrv", > + .data = &sysctl_mld_qrv, > + .maxlen = sizeof(int), > + .mode = 0644, > + .proc_handler = proc_dointvec_minmax, > + .extra1 = &one > + }, > { } > }; > > -- > 1.9.3 >