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