From 89b8245420dd6ef355bd67faec39de49e4fda767 Mon Sep 17 00:00:00 2001
From: florian <florian@openbsd.org>
Date: Wed, 22 Nov 2023 18:06:44 +0000
Subject: [PATCH] Recognize option ipv6-only-preferred (RFC8925).

"option option-108 00:00:07:08;" is unwieldy and error prone.

OK denis, kn, deraadt
---
 usr.sbin/dhcpd/dhcp-options.5 | 8 ++++++--
 usr.sbin/dhcpd/tables.c       | 4 ++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/usr.sbin/dhcpd/dhcp-options.5 b/usr.sbin/dhcpd/dhcp-options.5
index 25b168fdb21..80e9fe258c6 100644
--- a/usr.sbin/dhcpd/dhcp-options.5
+++ b/usr.sbin/dhcpd/dhcp-options.5
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: dhcp-options.5,v 1.32 2022/03/31 17:27:29 naddy Exp $
+.\"	$OpenBSD: dhcp-options.5,v 1.33 2023/11/22 18:06:44 florian Exp $
 .\"
 .\" Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium.
 .\" All rights reserved.
@@ -36,7 +36,7 @@
 .\" see ``http://www.isc.org/isc''.  To learn more about Vixie
 .\" Enterprises, see ``http://www.vix.com''.
 .\"
-.Dd $Mdocdate: March 31 2022 $
+.Dd $Mdocdate: November 22 2023 $
 .Dt DHCP-OPTIONS 5
 .Os
 .Sh NAME
@@ -346,6 +346,10 @@ This option specifies whether the client should configure its IP layer
 for packet forwarding.
 A value of 0 means disable IP forwarding, and a value of 1 means enable
 IP forwarding.
+.It Ic option ipv6-only-preferred Ar uint32 ;
+This option specifies that a NAT64 is available and the pool is IPv6-mostly
+capable.
+This option is specified in RFC 8925.
 .It Ic option irc-server Ar ip-address Oo , Ar ip-address ... Oc ;
 The
 .Ic irc-server
diff --git a/usr.sbin/dhcpd/tables.c b/usr.sbin/dhcpd/tables.c
index 6735a332a75..d9364cc7b97 100644
--- a/usr.sbin/dhcpd/tables.c
+++ b/usr.sbin/dhcpd/tables.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tables.c,v 1.14 2019/05/08 22:00:55 krw Exp $	*/
+/*	$OpenBSD: tables.c,v 1.15 2023/11/22 18:06:44 florian Exp $	*/
 
 /* Tables of information... */
 
@@ -184,7 +184,7 @@ struct option dhcp_options[256] = {
 	{ "option-105", "X",				&dhcp_universe, 105 },
 	{ "option-106", "X",				&dhcp_universe, 106 },
 	{ "option-107", "X",				&dhcp_universe, 107 },
-	{ "option-108", "X",				&dhcp_universe, 108 },
+	{ "ipv6-only-preferred", "L",			&dhcp_universe, 108 },
 	{ "option-109", "X",				&dhcp_universe, 109 },
 	{ "option-110", "X",				&dhcp_universe, 110 },
 	{ "option-111", "X",				&dhcp_universe, 111 },
-- 
2.20.1