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

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

Documentation/networking/ip-sysctl.txt

+5 −0
Original line number Diff line number Diff line
@@ -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

include/net/ipv6.h

+1 −0
Original line number Diff line number Diff line
@@ -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)			\

({									\

net/ipv6/mcast.c

+15 −10
Original line number Diff line number Diff line
@@ -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);

}

net/ipv6/sysctl_net_ipv6.c

+10 −0
Original line number Diff line number Diff line
@@ -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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