1/*	$NetBSD: dhcp4o6.c,v 1.3 2022/04/03 01:10:58 christos Exp $	*/
2
3/* dhcp4o6.c
4
5   DHCPv4 over DHCPv6 shared code... */
6
7/*
8 * Copyright (C) 2016-2022 Internet Systems Consortium, Inc. ("ISC")
9 *
10 * This Source Code Form is subject to the terms of the Mozilla Public
11 * License, v. 2.0. If a copy of the MPL was not distributed with this
12 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
15 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
16 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
17 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
18 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
19 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
20 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
21 *
22 *   Internet Systems Consortium, Inc.
23 *   PO Box 360
24 *   Newmarket, NH 03857 USA
25 *   <info@isc.org>
26 *   https://www.isc.org/
27 *
28 */
29
30#include <sys/cdefs.h>
31__RCSID("$NetBSD: dhcp4o6.c,v 1.3 2022/04/03 01:10:58 christos Exp $");
32
33#include "dhcpd.h"
34
35#ifdef DHCP4o6
36
37int dhcp4o6_fd = -1;
38omapi_object_t *dhcp4o6_object = NULL;
39omapi_object_type_t *dhcp4o6_type = NULL;
40
41static int dhcp4o6_readsocket(omapi_object_t *);
42
43/*
44 * DHCPv4 over DHCPv6 Inter Process Communication setup
45 *
46 * A UDP socket is created between ::1 port and ::1 port + 1
47 * (port is given in network order, the DHCPv6 side is bound to port,
48 *  the DHCPv4 side to port + 1. The socket descriptor is stored into
49 *  dhcp4o6_fd and an OMAPI handler is registered. Any failure is fatal.)
50 */
51void dhcp4o6_setup(u_int16_t port) {
52	struct sockaddr_in6 local6, remote6;
53	int flag;
54	isc_result_t status;
55
56	/* Register DHCPv4 over DHCPv6 forwarding. */
57	memset(&local6, 0, sizeof(local6));
58	local6.sin6_family = AF_INET6;
59	if (local_family == AF_INET6)
60		local6.sin6_port = port;
61	else
62		local6.sin6_port = htons(ntohs(port) + 1);
63	local6.sin6_addr.s6_addr[15] = 1;
64#ifdef HAVE_SA_LEN
65	local6.sin6_len = sizeof(local6);
66#endif
67	memset(&remote6, 0, sizeof(remote6));
68	remote6.sin6_family = AF_INET6;
69	if (local_family == AF_INET6)
70		remote6.sin6_port = htons(ntohs(port) + 1);
71	else
72		remote6.sin6_port = port;
73	remote6.sin6_addr.s6_addr[15] = 1;
74#ifdef HAVE_SA_LEN
75	remote6.sin6_len = sizeof(remote6);
76#endif
77
78	dhcp4o6_fd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
79	if (dhcp4o6_fd < 0)
80		log_fatal("Can't create dhcp4o6 socket: %m");
81	flag = 1;
82	if (setsockopt(dhcp4o6_fd, SOL_SOCKET, SO_REUSEADDR,
83		       (char *)&flag, sizeof(flag)) < 0)
84		log_fatal("Can't set SO_REUSEADDR option "
85			  "on dhcp4o6 socket: %m");
86	if (bind(dhcp4o6_fd,
87		 (struct sockaddr *)&local6,
88		 sizeof(local6)) < 0)
89		log_fatal("Can't bind dhcp4o6 socket: %m");
90	if (connect(dhcp4o6_fd,
91		    (struct sockaddr *)&remote6,
92		    sizeof(remote6)) < 0)
93		log_fatal("Can't connect dhcp4o6 socket: %m");
94
95	/* Omapi stuff. */
96	/* TODO: add tracing support. */
97	status = omapi_object_type_register(&dhcp4o6_type,
98					    "dhcp4o6",
99					    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
100					    sizeof(*dhcp4o6_object),
101					    0, RC_MISC);
102	if (status != ISC_R_SUCCESS)
103		log_fatal("Can't register dhcp4o6 type: %s",
104			  isc_result_totext(status));
105	status = omapi_object_allocate(&dhcp4o6_object, dhcp4o6_type, 0, MDL);
106	if (status != ISC_R_SUCCESS)
107		log_fatal("Can't allocate dhcp4o6 object: %s",
108			  isc_result_totext(status));
109	status = omapi_register_io_object(dhcp4o6_object,
110					  dhcp4o6_readsocket, 0,
111					  dhcpv4o6_handler, 0, 0);
112	if (status != ISC_R_SUCCESS)
113		log_fatal("Can't register dhcp4o6 handle: %s",
114			  isc_result_totext(status));
115}
116
117static int dhcp4o6_readsocket(omapi_object_t *h) {
118	IGNORE_UNUSED(h);
119	return dhcp4o6_fd;
120}
121#endif /* DHCP4o6 */
122