From 2f711939d2ea9dfaecebecd1324d2ec7a7a21f65 Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Tue, 2 Sep 2014 15:49:25 +0200 Subject: [PATCH] ipv6: add sysctl_mld_qrv to configure query robustness variable 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 Acked-by: Flavio Leitner Signed-off-by: David S. Miller --- Documentation/networking/ip-sysctl.txt | 5 +++++ include/net/ipv6.h | 1 + net/ipv6/mcast.c | 25 +++++++++++++++---------- net/ipv6/sysctl_net_ipv6.c | 10 ++++++++++ 4 files changed, 31 insertions(+), 10 deletions(-) diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 3cce8ea6b13..cfc71ac0f76 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -1152,6 +1152,11 @@ anycast_src_echo_reply - BOOLEAN FALSE: disabled Default: FALSE +mld_qrv - INTEGER + Controls the MLD query robustness variable (see RFC3810 9.1). + Default: 2 (as specified by RFC3810 9.1) + Minimum: 1 (as specified by RFC6636 4.5) + IPv6 Fragmentation: ip6frag_high_thresh - INTEGER diff --git a/include/net/ipv6.h b/include/net/ipv6.h index a2db816e846..7e247e9b876 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 70881795da9..64919425f1a 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 @@ -1191,15 +1192,16 @@ static void mld_update_qrv(struct inet6_dev *idev, * and SHOULD NOT be one. Catch this here if we ever run * into such a case in future. */ + const int min_qrv = min(MLD_QRV_DEFAULT, sysctl_mld_qrv); WARN_ON(idev->mc_qrv == 0); if (mlh2->mld2q_qrv > 0) idev->mc_qrv = mlh2->mld2q_qrv; - if (unlikely(idev->mc_qrv < 2)) { + if (unlikely(idev->mc_qrv < min_qrv)) { net_warn_ratelimited("IPv6: MLD: clamping QRV from %u to %u!\n", - idev->mc_qrv, MLD_QRV_DEFAULT); - idev->mc_qrv = MLD_QRV_DEFAULT; + idev->mc_qrv, min_qrv); + idev->mc_qrv = min_qrv; } } @@ -2478,6 +2480,14 @@ 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 +2498,7 @@ 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); for (i = idev->mc_list; i; i = i->next) igmp6_group_added(i); read_unlock_bh(&idev->lock); @@ -2508,13 +2519,7 @@ 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); write_unlock_bh(&idev->lock); } diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c index 0c56c93619e..c5c10fafcfe 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; + 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 + }, { } }; -- 2.46.0