rrenum.c revision 118787 
1/*	$FreeBSD: head/usr.sbin/rtadvd/rrenum.c 118787 2003-08-11 15:51:54Z ume $	*/
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_var.h>
40#include <net/route.h>
41#include <netinet/in.h>
42#include <netinet/in_var.h>
43#include <netinet/icmp6.h>
44
45#include <arpa/inet.h>
46
47#include <errno.h>
48#include <string.h>
49#include <stdlib.h>
50#include <syslog.h>
51#include "rtadvd.h"
52#include "rrenum.h"
53#include "if.h"
54
55#define	RR_ISSET_SEGNUM(segnum_bits, segnum) \
56	((((segnum_bits)[(segnum) >> 5]) & (1 << ((segnum) & 31))) != 0)
57#define	RR_SET_SEGNUM(segnum_bits, segnum) \
58	(((segnum_bits)[(segnum) >> 5]) |= (1 << ((segnum) & 31)))
59
60struct rr_operation {
61	u_long	rro_seqnum;
62	u_long	rro_segnum_bits[8];
63};
64
65static struct rr_operation rro;
66static int rr_rcvifindex;
67static int rrcmd2pco[RPM_PCO_MAX] = {
68	0,
69	SIOCAIFPREFIX_IN6,
70	SIOCCIFPREFIX_IN6,
71	SIOCSGIFPREFIX_IN6
72};
73static int s = -1;
74
75/*
76 * Check validity of a Prefix Control Operation(PCO).
77 * Return 0 on success, 1 on failure.
78 */
79static int
80rr_pco_check(int len, struct rr_pco_match *rpm)
81{
82	struct rr_pco_use *rpu, *rpulim;
83	int checklen;
84
85	/* rpm->rpm_len must be (4N * 3) as router-renum-05.txt */
86	if ((rpm->rpm_len - 3) < 0 || /* must be at least 3 */
87	    (rpm->rpm_len - 3) & 0x3) { /* must be multiple of 4 */
88		syslog(LOG_WARNING, "<%s> rpm_len %d is not 4N * 3",
89		       __func__, rpm->rpm_len);
90		return 1;
91	}
92	/* rpm->rpm_code must be valid value */
93	switch (rpm->rpm_code) {
94	case RPM_PCO_ADD:
95	case RPM_PCO_CHANGE:
96	case RPM_PCO_SETGLOBAL:
97		break;
98	default:
99		syslog(LOG_WARNING, "<%s> unknown rpm_code %d", __func__,
100		       rpm->rpm_code);
101		return 1;
102	}
103	/* rpm->rpm_matchlen must be 0 to 128 inclusive */
104	if (rpm->rpm_matchlen > 128) {
105		syslog(LOG_WARNING, "<%s> rpm_matchlen %d is over 128",
106		       __func__, rpm->rpm_matchlen);
107		return 1;
108	}
109
110	/*
111	 * rpu->rpu_uselen, rpu->rpu_keeplen, and sum of them must be
112	 * between 0 and 128 inclusive
113	 */
114	for (rpu = (struct rr_pco_use *)(rpm + 1),
115	     rpulim = (struct rr_pco_use *)((char *)rpm + len);
116	     rpu < rpulim;
117	     rpu += 1) {
118		checklen = rpu->rpu_uselen;
119		checklen += rpu->rpu_keeplen;
120		/*
121		 * omit these check, because either of rpu_uselen
122		 * and rpu_keeplen is unsigned char
123		 *  (128 > rpu_uselen > 0)
124		 *  (128 > rpu_keeplen > 0)
125		 *  (rpu_uselen + rpu_keeplen > 0)
126		 */
127		if (checklen > 128) {
128			syslog(LOG_WARNING, "<%s> sum of rpu_uselen %d and"
129			       " rpu_keeplen %d is %d(over 128)",
130			       __func__, rpu->rpu_uselen,
131			       rpu->rpu_keeplen,
132			       rpu->rpu_uselen + rpu->rpu_keeplen);
133			return 1;
134		}
135	}
136	return 0;
137}
138
139static void
140do_use_prefix(int len, struct rr_pco_match *rpm,
141	      struct in6_rrenumreq *irr, int ifindex)
142{
143	struct rr_pco_use *rpu, *rpulim;
144	struct rainfo *rai;
145	struct prefix *pp;
146
147	rpu = (struct rr_pco_use *)(rpm + 1);
148	rpulim = (struct rr_pco_use *)((char *)rpm + len);
149
150	if (rpu == rpulim) {	/* no use prefix */
151		if (rpm->rpm_code == RPM_PCO_ADD)
152			return;
153
154		irr->irr_u_uselen = 0;
155		irr->irr_u_keeplen = 0;
156		irr->irr_raf_mask_onlink = 0;
157		irr->irr_raf_mask_auto = 0;
158		irr->irr_vltime = 0;
159		irr->irr_pltime = 0;
160		memset(&irr->irr_flags, 0, sizeof(irr->irr_flags));
161		irr->irr_useprefix.sin6_len = 0; /* let it mean, no addition */
162		irr->irr_useprefix.sin6_family = 0;
163		irr->irr_useprefix.sin6_addr = in6addr_any;
164		if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
165		    errno != EADDRNOTAVAIL)
166			syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
167			       strerror(errno));
168		return;
169	}
170
171	for (rpu = (struct rr_pco_use *)(rpm + 1),
172	     rpulim = (struct rr_pco_use *)((char *)rpm + len);
173	     rpu < rpulim;
174	     rpu += 1) {
175		/* init in6_rrenumreq fields */
176		irr->irr_u_uselen = rpu->rpu_uselen;
177		irr->irr_u_keeplen = rpu->rpu_keeplen;
178		irr->irr_raf_mask_onlink =
179			(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK);
180		irr->irr_raf_mask_auto =
181			(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_AUTO);
182		irr->irr_vltime = ntohl(rpu->rpu_vltime);
183		irr->irr_pltime = ntohl(rpu->rpu_pltime);
184		irr->irr_raf_onlink =
185			(rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK) == 0 ? 0 : 1;
186		irr->irr_raf_auto =
187			(rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ? 0 : 1;
188		irr->irr_rrf_decrvalid =
189			(rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME) == 0 ? 0 : 1;
190		irr->irr_rrf_decrprefd =
191			(rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME) == 0 ? 0 : 1;
192		irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
193		irr->irr_useprefix.sin6_family = AF_INET6;
194		irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
195
196		if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
197		    errno != EADDRNOTAVAIL)
198			syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
199			       strerror(errno));
200
201		/* very adhoc: should be rewritten */
202		if (rpm->rpm_code == RPM_PCO_CHANGE &&
203		    IN6_ARE_ADDR_EQUAL(&rpm->rpm_prefix, &rpu->rpu_prefix) &&
204		    rpm->rpm_matchlen == rpu->rpu_uselen &&
205		    rpu->rpu_uselen == rpu->rpu_keeplen) {
206			if ((rai = if_indextorainfo(ifindex)) == NULL)
207				continue; /* non-advertising IF */
208
209			for (pp = rai->prefix.next; pp != &rai->prefix;
210			     pp = pp->next) {
211				struct timeval now;
212
213				if (prefix_match(&pp->prefix, pp->prefixlen,
214						 &rpm->rpm_prefix,
215						 rpm->rpm_matchlen)) {
216					/* change parameters */
217					pp->validlifetime = ntohl(rpu->rpu_vltime);
218					pp->preflifetime = ntohl(rpu->rpu_pltime);
219					if (irr->irr_rrf_decrvalid) {
220						gettimeofday(&now, 0);
221						pp->vltimeexpire =
222							now.tv_sec + pp->validlifetime;
223					} else
224						pp->vltimeexpire = 0;
225					if (irr->irr_rrf_decrprefd) {
226						gettimeofday(&now, 0);
227						pp->pltimeexpire =
228							now.tv_sec + pp->preflifetime;
229					} else
230						pp->pltimeexpire = 0;
231				}
232			}
233		}
234	}
235}
236
237/*
238 * process a Prefix Control Operation(PCO).
239 * return 0 on success, 1 on failure
240 */
241static int
242do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
243{
244	int ifindex = 0;
245	struct in6_rrenumreq irr;
246
247	if ((rr_pco_check(len, rpm) != NULL))
248		return 1;
249
250	if (s == -1 && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
251		syslog(LOG_ERR, "<%s> socket: %s", __func__,
252		       strerror(errno));
253		exit(1);
254	}
255
256	memset(&irr, 0, sizeof(irr));
257	irr.irr_origin = PR_ORIG_RR;
258	irr.irr_m_len = rpm->rpm_matchlen;
259	irr.irr_m_minlen = rpm->rpm_minlen;
260	irr.irr_m_maxlen = rpm->rpm_maxlen;
261	irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
262	irr.irr_matchprefix.sin6_family = AF_INET6;
263	irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
264
265	while (if_indextoname(++ifindex, irr.irr_name)) {
266		/*
267		 * if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and IFF_UP is off,
268		 * the interface is not applied
269		 */
270		if ((rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) == 0 &&
271		    (iflist[ifindex]->ifm_flags & IFF_UP) == 0)
272			continue;
273		/* TODO: interface scope check */
274		do_use_prefix(len, rpm, &irr, ifindex);
275	}
276	if (errno == ENXIO)
277		return 0;
278	else if (errno) {
279		syslog(LOG_ERR, "<%s> if_indextoname: %s", __func__,
280		       strerror(errno));
281		return 1;
282	}
283	return 0;
284}
285
286/*
287 * call do_pco() for each Prefix Control Operations(PCOs) in a received
288 * Router Renumbering Command packet.
289 * return 0 on success, 1 on failure
290 */
291static int
292do_rr(int len, struct icmp6_router_renum *rr)
293{
294	struct rr_pco_match *rpm;
295	char *cp, *lim;
296
297	lim = (char *)rr + len;
298	cp = (char *)(rr + 1);
299	len -= sizeof(struct icmp6_router_renum);
300
301	/* get iflist block from kernel again, to get up-to-date information */
302	init_iflist();
303
304	while (cp < lim) {
305		int rpmlen;
306
307		rpm = (struct rr_pco_match *)cp;
308		if (len < sizeof(struct rr_pco_match)) {
309		    tooshort:
310			syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
311			       "gabage at end of pkt?", __func__, len);
312			return 1;
313		}
314		rpmlen = rpm->rpm_len << 3;
315		if (len < rpmlen)
316			goto tooshort;
317
318		if (do_pco(rr, rpmlen, rpm)) {
319			syslog(LOG_WARNING, "<%s> invalid PCO", __func__);
320			goto next;
321		}
322
323	    next:
324		cp += rpmlen;
325		len -= rpmlen;
326	}
327
328	return 0;
329}
330
331/*
332 * check validity of a router renumbering command packet
333 * return 0 on success, 1 on failure
334 */
335static int
336rr_command_check(int len, struct icmp6_router_renum *rr, struct in6_addr *from,
337		 struct in6_addr *dst)
338{
339	u_char ntopbuf[INET6_ADDRSTRLEN];
340
341	/* omit rr minimal length check. hope kernel have done it. */
342	/* rr_command length check */
343	if (len < (sizeof(struct icmp6_router_renum) +
344		   sizeof(struct rr_pco_match))) {
345		syslog(LOG_ERR,	"<%s> rr_command len %d is too short",
346		       __func__, len);
347		return 1;
348	}
349
350	/* destination check. only for multicast. omit unicast check. */
351	if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
352	    !IN6_IS_ADDR_MC_SITELOCAL(dst)) {
353		syslog(LOG_ERR,	"<%s> dst mcast addr %s is illegal",
354		       __func__,
355		       inet_ntop(AF_INET6, dst, ntopbuf, INET6_ADDRSTRLEN));
356		return 1;
357	}
358
359	/* seqnum and segnum check */
360	if (rro.rro_seqnum > rr->rr_seqnum) {
361		syslog(LOG_WARNING,
362		       "<%s> rcvd old seqnum %d from %s",
363		       __func__, (u_int32_t)ntohl(rr->rr_seqnum),
364		       inet_ntop(AF_INET6, from, ntopbuf, INET6_ADDRSTRLEN));
365		return 1;
366	}
367	if (rro.rro_seqnum == rr->rr_seqnum &&
368	    (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
369	    RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
370		if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
371			syslog(LOG_WARNING,
372			       "<%s> rcvd duped segnum %d from %s",
373			       __func__, rr->rr_segnum,
374			       inet_ntop(AF_INET6, from, ntopbuf,
375					 INET6_ADDRSTRLEN));
376		return 0;
377	}
378
379	/* update seqnum */
380	if (rro.rro_seqnum != rr->rr_seqnum) {
381		/* then must be "<" */
382
383		/* init rro_segnum_bits */
384		memset(rro.rro_segnum_bits, 0,
385		       sizeof(rro.rro_segnum_bits));
386	}
387	rro.rro_seqnum = rr->rr_seqnum;
388
389	return 0;
390}
391
392static void
393rr_command_input(int len, struct icmp6_router_renum *rr,
394		 struct in6_addr *from, struct in6_addr *dst)
395{
396	/* rr_command validity check */
397	if (rr_command_check(len, rr, from, dst))
398		goto failed;
399	if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
400	    ICMP6_RR_FLAGS_TEST)
401		return;
402
403	/* do router renumbering */
404	if (do_rr(len, rr)) {
405		goto failed;
406	}
407
408	/* update segnum */
409	RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
410
411	return;
412
413    failed:
414	syslog(LOG_ERR, "<%s> received RR was invalid", __func__);
415	return;
416}
417
418void
419rr_input(int len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
420	 struct sockaddr_in6 *from, struct in6_addr *dst)
421{
422	u_char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
423
424	syslog(LOG_DEBUG,
425	       "<%s> RR received from %s to %s on %s",
426	       __func__,
427	       inet_ntop(AF_INET6, &from->sin6_addr,
428			 ntopbuf[0], INET6_ADDRSTRLEN),
429	       inet_ntop(AF_INET6, &dst, ntopbuf[1], INET6_ADDRSTRLEN),
430	       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
431
432	/* packet validation based on Section 4.1 of RFC2894 */
433	if (len < sizeof(struct icmp6_router_renum)) {
434		syslog(LOG_NOTICE,
435		       "<%s>: RR short message (size %d) from %s to %s on %s",
436		       __func__, len,
437		       inet_ntop(AF_INET6, &from->sin6_addr,
438				 ntopbuf[0], INET6_ADDRSTRLEN),
439		       inet_ntop(AF_INET6, &dst, ntopbuf[1], INET6_ADDRSTRLEN),
440		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
441		return;
442	}
443
444	/*
445	 * If the IPv6 destination address is neither an All Routers multicast
446	 * address [AARCH] nor one of the receiving router's unicast addresses,
447	 * the message MUST be discarded and SHOULD be logged to network
448	 * management.
449	 * We rely on the kernel input routine for unicast addresses, and thus
450	 * check multicast destinations only.
451	 */
452	if (IN6_IS_ADDR_MULTICAST(&pi->ipi6_addr) &&
453	    !IN6_ARE_ADDR_EQUAL(&in6a_site_allrouters, &pi->ipi6_addr)) {
454		syslog(LOG_NOTICE,
455		       "<%s>: RR message with invalid destination (%s) "
456		       "from %s on %s",
457		       __func__,
458		       inet_ntop(AF_INET6, &dst, ntopbuf[0], INET6_ADDRSTRLEN),
459		       inet_ntop(AF_INET6, &from->sin6_addr,
460				 ntopbuf[1], INET6_ADDRSTRLEN),
461		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
462		return;
463	}
464
465	rr_rcvifindex = pi->ipi6_ifindex;
466
467	switch (rr->rr_code) {
468	case ICMP6_ROUTER_RENUMBERING_COMMAND:
469		rr_command_input(len, rr, &from->sin6_addr, dst);
470		/* TODO: send reply msg */
471		break;
472	case ICMP6_ROUTER_RENUMBERING_RESULT:
473		/* RESULT will be processed by rrenumd */
474		break;
475	case ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET:
476		/* TODO: sequence number reset */
477		break;
478	default:
479		syslog(LOG_ERR,	"<%s> received unknown code %d",
480		       __func__, rr->rr_code);
481		break;
482
483	}
484
485	return;
486}
487