Commit 2f711939 authored by Hannes Frederic Sowa's avatar Hannes Frederic Sowa Committed by David S. Miller

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 <fbl@redhat.com>
Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: default avatarFlavio Leitner <fbl@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b89df95d
......@@ -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
......
......@@ -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) \
({ \
......
......@@ -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);
}
......
......@@ -16,6 +16,8 @@
#include <net/addrconf.h>
#include <net/inet_frag.h>
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
},
{ }
};
......
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