1/*	$FreeBSD$	*/
2/*	$KAME: rrenum.c,v 1.12 2002/06/10 19:59:47 itojun Exp $	*/
3
4/*-
5 * SPDX-License-Identifier: BSD-3-Clause
6 *
7 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the project nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34#include <sys/types.h>
35#include <sys/param.h>
36#include <sys/ioctl.h>
37#include <sys/queue.h>
38#include <sys/socket.h>
39#include <sys/sysctl.h>
40
41#include <net/if.h>
42#include <net/if_dl.h>
43#include <net/route.h>
44#include <netinet/in.h>
45#include <netinet/in_var.h>
46#include <netinet/icmp6.h>
47
48#include <arpa/inet.h>
49
50#include <errno.h>
51#include <netdb.h>
52#include <string.h>
53#include <stdlib.h>
54#include <time.h>
55#include <syslog.h>
56#include "rtadvd.h"
57#include "rrenum.h"
58#include "if.h"
59
60#define	RR_ISSET_SEGNUM(segnum_bits, segnum) \
61	((((segnum_bits)[(segnum) >> 5]) & (1 << ((segnum) & 31))) != 0)
62#define	RR_SET_SEGNUM(segnum_bits, segnum) \
63	(((segnum_bits)[(segnum) >> 5]) |= (1 << ((segnum) & 31)))
64
65struct rr_operation {
66	u_long	rro_seqnum;
67	u_long	rro_segnum_bits[8];
68};
69
70static struct rr_operation rro;
71static int rr_rcvifindex;
72static int rrcmd2pco[RPM_PCO_MAX] = {
73	0,
74	SIOCAIFPREFIX_IN6,
75	SIOCCIFPREFIX_IN6,
76	SIOCSGIFPREFIX_IN6
77};
78static int s = -1;
79
80/*
81 * Check validity of a Prefix Control Operation(PCO).
82 * return 0 on success, 1 on failure.
83 */
84static int
85rr_pco_check(int len, struct rr_pco_match *rpm)
86{
87	struct rr_pco_use *rpu, *rpulim;
88	int checklen;
89
90	/* rpm->rpm_len must be (4N * 3) as router-renum-05.txt */
91	if ((rpm->rpm_len - 3) < 0 || /* must be at least 3 */
92	    (rpm->rpm_len - 3) & 0x3) { /* must be multiple of 4 */
93		syslog(LOG_WARNING, "<%s> rpm_len %d is not 4N * 3",
94		    __func__, rpm->rpm_len);
95		return (1);
96	}
97	/* rpm->rpm_code must be valid value */
98	switch (rpm->rpm_code) {
99	case RPM_PCO_ADD:
100	case RPM_PCO_CHANGE:
101	case RPM_PCO_SETGLOBAL:
102		break;
103	default:
104		syslog(LOG_WARNING, "<%s> unknown rpm_code %d", __func__,
105		    rpm->rpm_code);
106		return (1);
107	}
108	/* rpm->rpm_matchlen must be 0 to 128 inclusive */
109	if (rpm->rpm_matchlen > 128) {
110		syslog(LOG_WARNING, "<%s> rpm_matchlen %d is over 128",
111		    __func__, rpm->rpm_matchlen);
112		return (1);
113	}
114
115	/*
116	 * rpu->rpu_uselen, rpu->rpu_keeplen, and sum of them must be
117	 * between 0 and 128 inclusive
118	 */
119	for (rpu = (struct rr_pco_use *)(rpm + 1),
120	     rpulim = (struct rr_pco_use *)((char *)rpm + len);
121	     rpu < rpulim;
122	     rpu += 1) {
123		checklen = rpu->rpu_uselen;
124		checklen += rpu->rpu_keeplen;
125		/*
126		 * omit these check, because either of rpu_uselen
127		 * and rpu_keeplen is unsigned char
128		 *  (128 > rpu_uselen > 0)
129		 *  (128 > rpu_keeplen > 0)
130		 *  (rpu_uselen + rpu_keeplen > 0)
131		 */
132		if (checklen > 128) {
133			syslog(LOG_WARNING, "<%s> sum of rpu_uselen %d and"
134			    " rpu_keeplen %d is %d(over 128)",
135			    __func__, rpu->rpu_uselen, rpu->rpu_keeplen,
136			    rpu->rpu_uselen + rpu->rpu_keeplen);
137			return (1);
138		}
139	}
140	return (0);
141}
142
143static void
144do_use_prefix(int len, struct rr_pco_match *rpm,
145	struct in6_rrenumreq *irr, int ifindex)
146{
147	struct rr_pco_use *rpu, *rpulim;
148	struct rainfo *rai;
149	struct ifinfo *ifi;
150	struct prefix *pfx;
151
152	rpu = (struct rr_pco_use *)(rpm + 1);
153	rpulim = (struct rr_pco_use *)((char *)rpm + len);
154
155	if (rpu == rpulim) {	/* no use prefix */
156		if (rpm->rpm_code == RPM_PCO_ADD)
157			return;
158
159		irr->irr_u_uselen = 0;
160		irr->irr_u_keeplen = 0;
161		irr->irr_raf_mask_onlink = 0;
162		irr->irr_raf_mask_auto = 0;
163		irr->irr_vltime = 0;
164		irr->irr_pltime = 0;
165		memset(&irr->irr_flags, 0, sizeof(irr->irr_flags));
166		irr->irr_useprefix.sin6_len = 0; /* let it mean, no addition */
167		irr->irr_useprefix.sin6_family = 0;
168		irr->irr_useprefix.sin6_addr = in6addr_any;
169		if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
170		    errno != EADDRNOTAVAIL)
171			syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
172			    strerror(errno));
173		return;
174	}
175
176	for (rpu = (struct rr_pco_use *)(rpm + 1),
177	     rpulim = (struct rr_pco_use *)((char *)rpm + len);
178	     rpu < rpulim;
179	     rpu += 1) {
180		/* init in6_rrenumreq fields */
181		irr->irr_u_uselen = rpu->rpu_uselen;
182		irr->irr_u_keeplen = rpu->rpu_keeplen;
183		irr->irr_raf_mask_onlink =
184		    !!(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK);
185		irr->irr_raf_mask_auto =
186		    !!(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_AUTO);
187		irr->irr_vltime = ntohl(rpu->rpu_vltime);
188		irr->irr_pltime = ntohl(rpu->rpu_pltime);
189		irr->irr_raf_onlink =
190		    (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK) == 0 ?
191		    0 : 1;
192		irr->irr_raf_auto =
193		    (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ?
194		    0 : 1;
195		irr->irr_rrf_decrvalid =
196		    (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME) == 0 ?
197		    0 : 1;
198		irr->irr_rrf_decrprefd =
199		    (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME) == 0 ?
200		    0 : 1;
201		irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
202		irr->irr_useprefix.sin6_family = AF_INET6;
203		irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
204
205		if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
206		    errno != EADDRNOTAVAIL)
207			syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
208			    strerror(errno));
209
210		/* very adhoc: should be rewritten */
211		if (rpm->rpm_code == RPM_PCO_CHANGE &&
212		    IN6_ARE_ADDR_EQUAL(&rpm->rpm_prefix, &rpu->rpu_prefix) &&
213		    rpm->rpm_matchlen == rpu->rpu_uselen &&
214		    rpu->rpu_uselen == rpu->rpu_keeplen) {
215			ifi = if_indextoifinfo(ifindex);
216			if (ifi == NULL || ifi->ifi_rainfo == NULL)
217				continue; /* non-advertising IF */
218			rai = ifi->ifi_rainfo;
219
220			TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) {
221				struct timespec now;
222
223				if (prefix_match(&pfx->pfx_prefix,
224				    pfx->pfx_prefixlen, &rpm->rpm_prefix,
225				    rpm->rpm_matchlen)) {
226					/* change parameters */
227					pfx->pfx_validlifetime =
228					    ntohl(rpu->rpu_vltime);
229					pfx->pfx_preflifetime =
230					    ntohl(rpu->rpu_pltime);
231					if (irr->irr_rrf_decrvalid) {
232						clock_gettime(CLOCK_MONOTONIC_FAST,
233						    &now);
234						pfx->pfx_vltimeexpire =
235						    now.tv_sec +
236						    pfx->pfx_validlifetime;
237					} else
238						pfx->pfx_vltimeexpire = 0;
239					if (irr->irr_rrf_decrprefd) {
240						clock_gettime(CLOCK_MONOTONIC_FAST,
241						    &now);
242						pfx->pfx_pltimeexpire =
243						    now.tv_sec +
244						    pfx->pfx_preflifetime;
245					} else
246						pfx->pfx_pltimeexpire = 0;
247				}
248			}
249		}
250	}
251}
252
253/*
254 * process a Prefix Control Operation(PCO).
255 * return 0 on success, 1 on failure
256 */
257static int
258do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
259{
260	int ifindex = 0;
261	struct in6_rrenumreq irr;
262	struct ifinfo *ifi;
263
264	if ((rr_pco_check(len, rpm) != 0))
265		return (1);
266
267	if (s == -1 && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
268		syslog(LOG_ERR, "<%s> socket: %s", __func__,
269		    strerror(errno));
270		exit(1);
271	}
272
273	memset(&irr, 0, sizeof(irr));
274	irr.irr_origin = PR_ORIG_RR;
275	irr.irr_m_len = rpm->rpm_matchlen;
276	irr.irr_m_minlen = rpm->rpm_minlen;
277	irr.irr_m_maxlen = rpm->rpm_maxlen;
278	irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
279	irr.irr_matchprefix.sin6_family = AF_INET6;
280	irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
281
282	while (if_indextoname(++ifindex, irr.irr_name)) {
283		ifi = if_indextoifinfo(ifindex);
284		if (ifi == NULL) {
285			syslog(LOG_ERR, "<%s> ifindex not found.",
286			    __func__);
287			return (1);
288		}
289		/*
290		 * if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and
291		 * IFF_UP is off, the interface is not applied
292		 */
293		if ((rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) == 0 &&
294		    (ifi->ifi_flags & IFF_UP) == 0)
295			continue;
296		/* TODO: interface scope check */
297		do_use_prefix(len, rpm, &irr, ifindex);
298	}
299	if (errno == ENXIO)
300		return (0);
301	else if (errno) {
302		syslog(LOG_ERR, "<%s> if_indextoname: %s", __func__,
303		    strerror(errno));
304		return (1);
305	}
306	return (0);
307}
308
309/*
310 * call do_pco() for each Prefix Control Operations(PCOs) in a received
311 * Router Renumbering Command packet.
312 * return 0 on success, 1 on failure
313 */
314static int
315do_rr(int len, struct icmp6_router_renum *rr)
316{
317	struct rr_pco_match *rpm;
318	char *cp, *lim;
319
320	lim = (char *)rr + len;
321	cp = (char *)(rr + 1);
322	len -= sizeof(struct icmp6_router_renum);
323
324	update_ifinfo(&ifilist, UPDATE_IFINFO_ALL);
325
326	while (cp < lim) {
327		int rpmlen;
328
329		rpm = (struct rr_pco_match *)cp;
330		if ((size_t)len < sizeof(struct rr_pco_match)) {
331		    tooshort:
332			syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
333			    "garbage at end of pkt?", __func__, len);
334			return (1);
335		}
336		rpmlen = rpm->rpm_len << 3;
337		if (len < rpmlen)
338			goto tooshort;
339
340		if (do_pco(rr, rpmlen, rpm)) {
341			syslog(LOG_WARNING, "<%s> invalid PCO", __func__);
342			goto next;
343		}
344
345	    next:
346		cp += rpmlen;
347		len -= rpmlen;
348	}
349
350	return (0);
351}
352
353/*
354 * check validity of a router renumbering command packet
355 * return 0 on success, 1 on failure
356 */
357static int
358rr_command_check(int len, struct icmp6_router_renum *rr, struct in6_addr *from,
359	struct in6_addr *dst)
360{
361	u_char ntopbuf[INET6_ADDRSTRLEN];
362
363	/* omit rr minimal length check. hope kernel have done it. */
364	/* rr_command length check */
365	if ((size_t)len < (sizeof(struct icmp6_router_renum) +
366	    sizeof(struct rr_pco_match))) {
367		syslog(LOG_ERR,	"<%s> rr_command len %d is too short",
368		    __func__, len);
369		return (1);
370	}
371
372	/* destination check. only for multicast. omit unicast check. */
373	if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
374	    !IN6_IS_ADDR_MC_SITELOCAL(dst)) {
375		syslog(LOG_ERR,	"<%s> dst mcast addr %s is illegal",
376		    __func__,
377		    inet_ntop(AF_INET6, dst, ntopbuf, sizeof(ntopbuf)));
378		return (1);
379	}
380
381	/* seqnum and segnum check */
382	if (rro.rro_seqnum > rr->rr_seqnum) {
383		syslog(LOG_WARNING,
384		    "<%s> rcvd old seqnum %d from %s",
385		    __func__, (u_int32_t)ntohl(rr->rr_seqnum),
386		   inet_ntop(AF_INET6, from, ntopbuf, sizeof(ntopbuf)));
387		return (1);
388	}
389	if (rro.rro_seqnum == rr->rr_seqnum &&
390	    (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
391	    RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
392		if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
393			syslog(LOG_WARNING,
394			    "<%s> rcvd duped segnum %d from %s",
395			    __func__, rr->rr_segnum, inet_ntop(AF_INET6, from,
396				ntopbuf, sizeof(ntopbuf)));
397		return (0);
398	}
399
400	/* update seqnum */
401	if (rro.rro_seqnum != rr->rr_seqnum) {
402		/* then must be "<" */
403
404		/* init rro_segnum_bits */
405		memset(rro.rro_segnum_bits, 0,
406		    sizeof(rro.rro_segnum_bits));
407	}
408	rro.rro_seqnum = rr->rr_seqnum;
409
410	return (0);
411}
412
413static void
414rr_command_input(int len, struct icmp6_router_renum *rr,
415	struct in6_addr *from, struct in6_addr *dst)
416{
417	/* rr_command validity check */
418	if (rr_command_check(len, rr, from, dst))
419		goto failed;
420	if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
421	    ICMP6_RR_FLAGS_TEST)
422		return;
423
424	/* do router renumbering */
425	if (do_rr(len, rr))
426		goto failed;
427
428	/* update segnum */
429	RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
430
431	return;
432
433    failed:
434	syslog(LOG_ERR, "<%s> received RR was invalid", __func__);
435	return;
436}
437
438void
439rr_input(int len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
440	struct sockaddr_in6 *from, struct in6_addr *dst)
441{
442	u_char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
443
444	syslog(LOG_DEBUG,
445	    "<%s> RR received from %s to %s on %s",
446	    __func__,
447	    inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[0] ,sizeof(ntopbuf[0])),
448	    inet_ntop(AF_INET6, &dst, ntopbuf[1], sizeof(ntopbuf[1])),
449	    if_indextoname(pi->ipi6_ifindex, ifnamebuf));
450
451	/* packet validation based on Section 4.1 of RFC2894 */
452	if ((size_t)len < sizeof(struct icmp6_router_renum)) {
453		syslog(LOG_NOTICE,
454		    "<%s>: RR short message (size %d) from %s to %s on %s",
455		    __func__, len,
456		    inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[0],
457			sizeof(ntopbuf[0])),
458		    inet_ntop(AF_INET6, &dst, ntopbuf[1], sizeof(ntopbuf[1])),
459		    if_indextoname(pi->ipi6_ifindex, ifnamebuf));
460		return;
461	}
462
463	/*
464	 * If the IPv6 destination address is neither an All Routers multicast
465	 * address [AARCH] nor one of the receiving router's unicast addresses,
466	 * the message MUST be discarded and SHOULD be logged to network
467	 * management.
468	 * We rely on the kernel input routine for unicast addresses, and thus
469	 * check multicast destinations only.
470	 */
471	if (IN6_IS_ADDR_MULTICAST(&pi->ipi6_addr) && !IN6_ARE_ADDR_EQUAL(
472	    &sin6_sitelocal_allrouters.sin6_addr, &pi->ipi6_addr)) {
473		syslog(LOG_NOTICE,
474		    "<%s>: RR message with invalid destination (%s) "
475		    "from %s on %s",
476		    __func__,
477		    inet_ntop(AF_INET6, &dst, ntopbuf[0], sizeof(ntopbuf[0])),
478		    inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[1],
479			      sizeof(ntopbuf[1])),
480		    if_indextoname(pi->ipi6_ifindex, ifnamebuf));
481		return;
482	}
483
484	rr_rcvifindex = pi->ipi6_ifindex;
485
486	switch (rr->rr_code) {
487	case ICMP6_ROUTER_RENUMBERING_COMMAND:
488		rr_command_input(len, rr, &from->sin6_addr, dst);
489		/* TODO: send reply msg */
490		break;
491	case ICMP6_ROUTER_RENUMBERING_RESULT:
492		/* RESULT will be processed by rrenumd */
493		break;
494	case ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET:
495		/* TODO: sequence number reset */
496		break;
497	default:
498		syslog(LOG_ERR,	"<%s> received unknown code %d",
499		    __func__, rr->rr_code);
500		break;
501
502	}
503
504	return;
505}
506