Unlock ICMPV6CTL_ND6_DELAY case of icmp6_sysctl().

`nd6_delay' loaded only once in nd6_resolve().

ok bluhm

Author: mvs

sys/netinet6/icmp6.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: icmp6.c,v 1.272 2025/08/02 09:03:54 mvs Exp $	*/
+/*	$OpenBSD: icmp6.c,v 1.273 2025/08/02 12:53:04 mvs Exp $	*/
 /*	$KAME: icmp6.c,v 1.217 2001/06/20 15:03:29 jinmei Exp $	*/
 
 /*
@@ -1774,8 +1774,11 @@ icmp6_mtudisc_timeout(struct rtentry *rt, u_int rtableid)
 }
 
 #ifndef SMALL_KERNEL
-const struct sysctl_bounded_args icmpv6ctl_vars[] = {
+const struct sysctl_bounded_args icmpv6ctl_vars_unlocked[] = {
 	{ ICMPV6CTL_ND6_DELAY, &nd6_delay, 0, INT_MAX },
+};
+
+const struct sysctl_bounded_args icmpv6ctl_vars[] = {
 	{ ICMPV6CTL_ND6_UMAXTRIES, &nd6_umaxtries, 0, INT_MAX },
 	{ ICMPV6CTL_ND6_MMAXTRIES, &nd6_mmaxtries, 0, INT_MAX },
 	{ ICMPV6CTL_ERRPPSLIMIT, &icmp6errppslim, -1, 1000 },
@@ -1843,6 +1846,12 @@ icmp6_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
 		    atomic_load_int(&ln_hold_total));
 		break;
 
+	case ICMPV6CTL_ND6_DELAY:
+		error = sysctl_bounded_arr(icmpv6ctl_vars_unlocked,
+		    nitems(icmpv6ctl_vars_unlocked), name, namelen,
+		    oldp, oldlenp, newp, newlen);
+		break;
+
 	default:
 		NET_LOCK();
 		error = sysctl_bounded_arr(icmpv6ctl_vars,

sys/netinet6/nd6.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: nd6.c,v 1.293 2025/07/26 01:16:59 mvs Exp $	*/
+/*	$OpenBSD: nd6.c,v 1.294 2025/08/02 12:53:04 mvs Exp $	*/
 /*	$KAME: nd6.c,v 1.280 2002/06/08 19:52:07 itojun Exp $	*/
 
 /*
@@ -75,7 +75,7 @@
 /* timer values */
 int	nd6_timer_next	= -1;	/* at which uptime nd6_timer runs */
 time_t	nd6_expire_next	= -1;	/* at which uptime nd6_expire runs */
-int	nd6_delay	= 5;	/* delay first probe time 5 second */
+int	nd6_delay	= 5;	/* [a] delay first probe time 5 second */
 int	nd6_umaxtries	= 3;	/* maximum unicast query */
 int	nd6_mmaxtries	= 3;	/* maximum multicast query */
 int	nd6_gctimer	= (60 * 60 * 24); /* 1 day: garbage collection timer */
@@ -1307,7 +1307,7 @@ nd6_resolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m,
 	if (ln->ln_state == ND6_LLINFO_STALE) {
 		ln->ln_asked = 0;
 		ln->ln_state = ND6_LLINFO_DELAY;
-		nd6_llinfo_settimer(ln, nd6_delay);
+		nd6_llinfo_settimer(ln, atomic_load_int(&nd6_delay));
 	}
 
 	/*