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