Read-only access from sysctl(2) interface.

Index: sys/netinet6/ip6_input.c
===================================================================
RCS file: /cvs/src/sys/netinet6/ip6_input.c,v
diff -u -p -r1.275 ip6_input.c
--- sys/netinet6/ip6_input.c	23 Jun 2025 09:16:32 -0000	1.275
+++ sys/netinet6/ip6_input.c	23 Jun 2025 13:12:13 -0000
@@ -1450,13 +1450,13 @@ extern int ip6_mrtproto;
 const struct sysctl_bounded_args ipv6ctl_vars_unlocked[] = {
 	{ IPV6CTL_FORWARDING, &ip6_forwarding, 0, 2 },
 	{ IPV6CTL_SENDREDIRECTS, &ip6_sendredirects, 0, 1 },
-};
-
-const struct sysctl_bounded_args ipv6ctl_vars[] = {
 	{ IPV6CTL_DAD_PENDING, &ip6_dad_pending, SYSCTL_INT_READONLY },
 #ifdef MROUTING
 	{ IPV6CTL_MRTPROTO, &ip6_mrtproto, SYSCTL_INT_READONLY },
 #endif
+};
+
+const struct sysctl_bounded_args ipv6ctl_vars[] = {
 	{ IPV6CTL_DEFHLIM, &ip6_defhlim, 0, 255 },
 	{ IPV6CTL_MAXFRAGPACKETS, &ip6_maxfragpackets, 0, 1000 },
 	{ IPV6CTL_LOG_INTERVAL, &ip6_log_interval, 0, INT_MAX },
@@ -1581,6 +1581,10 @@ ip6_sysctl(int *name, u_int namelen, voi
 	}
 	case IPV6CTL_FORWARDING:
 	case IPV6CTL_SENDREDIRECTS:
+	case IPV6CTL_DAD_PENDING:
+#ifdef MROUTING
+	case IPV6CTL_MRTPROTO:
+#endif
 		return (sysctl_bounded_arr(
 		    ipv6ctl_vars_unlocked, nitems(ipv6ctl_vars_unlocked),
 		    name, namelen, oldp, oldlenp, newp, newlen));