rrenum.c revision 222732 
168673Sobrien/*	$FreeBSD: head/usr.sbin/rtadvd/rrenum.c 222732 2011-06-06 03:06:43Z hrs $	*/
277298Sobrien/*	$KAME: rrenum.c,v 1.12 2002/06/10 19:59:47 itojun Exp $	*/
368673Sobrien
468673Sobrien/*
568673Sobrien * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
668673Sobrien * All rights reserved.
768673Sobrien *
868673Sobrien * Redistribution and use in source and binary forms, with or without
968673Sobrien * modification, are permitted provided that the following conditions
1068673Sobrien * are met:
1168673Sobrien * 1. Redistributions of source code must retain the above copyright
1268673Sobrien *    notice, this list of conditions and the following disclaimer.
1368673Sobrien * 2. Redistributions in binary form must reproduce the above copyright
1468673Sobrien *    notice, this list of conditions and the following disclaimer in the
1568673Sobrien *    documentation and/or other materials provided with the distribution.
1668673Sobrien * 3. Neither the name of the project nor the names of its contributors
1768673Sobrien *    may be used to endorse or promote products derived from this software
1868673Sobrien *    without specific prior written permission.
1968673Sobrien *
2068673Sobrien * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
2168673Sobrien * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
2268673Sobrien * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
2368673Sobrien * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
2468673Sobrien * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
2568673Sobrien * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
2668673Sobrien * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
2768673Sobrien * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
2868673Sobrien * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
2968673Sobrien * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
3068673Sobrien * SUCH DAMAGE.
3168673Sobrien */
3268673Sobrien#include <sys/types.h>
3368673Sobrien#include <sys/param.h>
3468673Sobrien#include <sys/ioctl.h>
3568673Sobrien#include <sys/socket.h>
3668673Sobrien#include <sys/sysctl.h>
3777298Sobrien
3868673Sobrien#include <net/if.h>
3968673Sobrien#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 <netdb.h>
49#include <string.h>
50#include <stdlib.h>
51#include <syslog.h>
52#include "rtadvd.h"
53#include "rrenum.h"
54#include "if.h"
55
56#define	RR_ISSET_SEGNUM(segnum_bits, segnum) \
57	((((segnum_bits)[(segnum) >> 5]) & (1 << ((segnum) & 31))) != 0)
58#define	RR_SET_SEGNUM(segnum_bits, segnum) \
59	(((segnum_bits)[(segnum) >> 5]) |= (1 << ((segnum) & 31)))
60
61struct rr_operation {
62	u_long	rro_seqnum;
63	u_long	rro_segnum_bits[8];
64};
65
66static struct rr_operation rro;
67static int rr_rcvifindex;
68static int rrcmd2pco[RPM_PCO_MAX] = {
69	0,
70	SIOCAIFPREFIX_IN6,
71	SIOCCIFPREFIX_IN6,
72	SIOCSGIFPREFIX_IN6
73};
74static int s = -1;
75
76/*
77 * Check validity of a Prefix Control Operation(PCO).
78 * return 0 on success, 1 on failure.
79 */
80static int
81rr_pco_check(int len, struct rr_pco_match *rpm)
82{
83	struct rr_pco_use *rpu, *rpulim;
84	int checklen;
85
86	/* rpm->rpm_len must be (4N * 3) as router-renum-05.txt */
87	if ((rpm->rpm_len - 3) < 0 || /* must be at least 3 */
88	    (rpm->rpm_len - 3) & 0x3) { /* must be multiple of 4 */
89		syslog(LOG_WARNING, "<%s> rpm_len %d is not 4N * 3",
90		    __func__, rpm->rpm_len);
91		return (1);
92	}
93	/* rpm->rpm_code must be valid value */
94	switch (rpm->rpm_code) {
95	case RPM_PCO_ADD:
96	case RPM_PCO_CHANGE:
97	case RPM_PCO_SETGLOBAL:
98		break;
99	default:
100		syslog(LOG_WARNING, "<%s> unknown rpm_code %d", __func__,
101		    rpm->rpm_code);
102		return (1);
103	}
104	/* rpm->rpm_matchlen must be 0 to 128 inclusive */
105	if (rpm->rpm_matchlen > 128) {
106		syslog(LOG_WARNING, "<%s> rpm_matchlen %d is over 128",
107		    __func__, rpm->rpm_matchlen);
108		return (1);
109	}
110
111	/*
112	 * rpu->rpu_uselen, rpu->rpu_keeplen, and sum of them must be
113	 * between 0 and 128 inclusive
114	 */
115	for (rpu = (struct rr_pco_use *)(rpm + 1),
116	     rpulim = (struct rr_pco_use *)((char *)rpm + len);
117	     rpu < rpulim;
118	     rpu += 1) {
119		checklen = rpu->rpu_uselen;
120		checklen += rpu->rpu_keeplen;
121		/*
122		 * omit these check, because either of rpu_uselen
123		 * and rpu_keeplen is unsigned char
124		 *  (128 > rpu_uselen > 0)
125		 *  (128 > rpu_keeplen > 0)
126		 *  (rpu_uselen + rpu_keeplen > 0)
127		 */
128		if (checklen > 128) {
129			syslog(LOG_WARNING, "<%s> sum of rpu_uselen %d and"
130			    " rpu_keeplen %d is %d(over 128)",
131			    __func__, rpu->rpu_uselen, 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 *pfx;
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 ?
186		    0 : 1;
187		irr->irr_raf_auto =
188		    (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ?
189		    0 : 1;
190		irr->irr_rrf_decrvalid =
191		    (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME) == 0 ?
192		    0 : 1;
193		irr->irr_rrf_decrprefd =
194		    (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME) == 0 ?
195		    0 : 1;
196		irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
197		irr->irr_useprefix.sin6_family = AF_INET6;
198		irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
199
200		if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
201		    errno != EADDRNOTAVAIL)
202			syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
203			    strerror(errno));
204
205		/* very adhoc: should be rewritten */
206		if (rpm->rpm_code == RPM_PCO_CHANGE &&
207		    IN6_ARE_ADDR_EQUAL(&rpm->rpm_prefix, &rpu->rpu_prefix) &&
208		    rpm->rpm_matchlen == rpu->rpu_uselen &&
209		    rpu->rpu_uselen == rpu->rpu_keeplen) {
210			if ((rai = if_indextorainfo(ifindex)) == NULL)
211				continue; /* non-advertising IF */
212
213			TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) {
214				struct timeval now;
215
216				if (prefix_match(&pfx->pfx_prefix,
217				    pfx->pfx_prefixlen, &rpm->rpm_prefix,
218				    rpm->rpm_matchlen)) {
219					/* change parameters */
220					pfx->pfx_validlifetime =
221					    ntohl(rpu->rpu_vltime);
222					pfx->pfx_preflifetime =
223					    ntohl(rpu->rpu_pltime);
224					if (irr->irr_rrf_decrvalid) {
225						gettimeofday(&now, 0);
226						pfx->pfx_vltimeexpire =
227						    now.tv_sec +
228						    pfx->pfx_validlifetime;
229					} else
230						pfx->pfx_vltimeexpire = 0;
231					if (irr->irr_rrf_decrprefd) {
232						gettimeofday(&now, 0);
233						pfx->pfx_pltimeexpire =
234						    now.tv_sec +
235						    pfx->pfx_preflifetime;
236					} else
237						pfx->pfx_pltimeexpire = 0;
238				}
239			}
240		}
241	}
242}
243
244/*
245 * process a Prefix Control Operation(PCO).
246 * return 0 on success, 1 on failure
247 */
248static int
249do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
250{
251	int ifindex = 0;
252	struct in6_rrenumreq irr;
253
254	if ((rr_pco_check(len, rpm) != 0))
255		return (1);
256
257	if (s == -1 && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
258		syslog(LOG_ERR, "<%s> socket: %s", __func__,
259		    strerror(errno));
260		exit(1);
261	}
262
263	memset(&irr, 0, sizeof(irr));
264	irr.irr_origin = PR_ORIG_RR;
265	irr.irr_m_len = rpm->rpm_matchlen;
266	irr.irr_m_minlen = rpm->rpm_minlen;
267	irr.irr_m_maxlen = rpm->rpm_maxlen;
268	irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
269	irr.irr_matchprefix.sin6_family = AF_INET6;
270	irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
271
272	while (if_indextoname(++ifindex, irr.irr_name)) {
273		/*
274		 * if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and
275		 * IFF_UP is off, the interface is not applied
276		 */
277		if ((rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) == 0 &&
278		    (iflist[ifindex]->ifm_flags & IFF_UP) == 0)
279			continue;
280		/* TODO: interface scope check */
281		do_use_prefix(len, rpm, &irr, ifindex);
282	}
283	if (errno == ENXIO)
284		return (0);
285	else if (errno) {
286		syslog(LOG_ERR, "<%s> if_indextoname: %s", __func__,
287		    strerror(errno));
288		return (1);
289	}
290	return (0);
291}
292
293/*
294 * call do_pco() for each Prefix Control Operations(PCOs) in a received
295 * Router Renumbering Command packet.
296 * return 0 on success, 1 on failure
297 */
298static int
299do_rr(int len, struct icmp6_router_renum *rr)
300{
301	struct rr_pco_match *rpm;
302	char *cp, *lim;
303
304	lim = (char *)rr + len;
305	cp = (char *)(rr + 1);
306	len -= sizeof(struct icmp6_router_renum);
307
308	/* get iflist block from kernel again, to get up-to-date information */
309	init_iflist();
310
311	while (cp < lim) {
312		int rpmlen;
313
314		rpm = (struct rr_pco_match *)cp;
315		if ((size_t)len < sizeof(struct rr_pco_match)) {
316		    tooshort:
317			syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
318			    "gabage at end of pkt?", __func__, len);
319			return (1);
320		}
321		rpmlen = rpm->rpm_len << 3;
322		if (len < rpmlen)
323			goto tooshort;
324
325		if (do_pco(rr, rpmlen, rpm)) {
326			syslog(LOG_WARNING, "<%s> invalid PCO", __func__);
327			goto next;
328		}
329
330	    next:
331		cp += rpmlen;
332		len -= rpmlen;
333	}
334
335	return (0);
336}
337
338/*
339 * check validity of a router renumbering command packet
340 * return 0 on success, 1 on failure
341 */
342static int
343rr_command_check(int len, struct icmp6_router_renum *rr, struct in6_addr *from,
344	struct in6_addr *dst)
345{
346	u_char ntopbuf[INET6_ADDRSTRLEN];
347
348	/* omit rr minimal length check. hope kernel have done it. */
349	/* rr_command length check */
350	if ((size_t)len < (sizeof(struct icmp6_router_renum) +
351	    sizeof(struct rr_pco_match))) {
352		syslog(LOG_ERR,	"<%s> rr_command len %d is too short",
353		    __func__, len);
354		return (1);
355	}
356
357	/* destination check. only for multicast. omit unicast check. */
358	if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
359	    !IN6_IS_ADDR_MC_SITELOCAL(dst)) {
360		syslog(LOG_ERR,	"<%s> dst mcast addr %s is illegal",
361		    __func__,
362		    inet_ntop(AF_INET6, dst, ntopbuf, sizeof(ntopbuf)));
363		return (1);
364	}
365
366	/* seqnum and segnum check */
367	if (rro.rro_seqnum > rr->rr_seqnum) {
368		syslog(LOG_WARNING,
369		    "<%s> rcvd old seqnum %d from %s",
370		    __func__, (u_int32_t)ntohl(rr->rr_seqnum),
371		   inet_ntop(AF_INET6, from, ntopbuf, sizeof(ntopbuf)));
372		return (1);
373	}
374	if (rro.rro_seqnum == rr->rr_seqnum &&
375	    (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
376	    RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
377		if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
378			syslog(LOG_WARNING,
379			    "<%s> rcvd duped segnum %d from %s",
380			    __func__, rr->rr_segnum, inet_ntop(AF_INET6, from,
381				ntopbuf, sizeof(ntopbuf)));
382		return (0);
383	}
384
385	/* update seqnum */
386	if (rro.rro_seqnum != rr->rr_seqnum) {
387		/* then must be "<" */
388
389		/* init rro_segnum_bits */
390		memset(rro.rro_segnum_bits, 0,
391		    sizeof(rro.rro_segnum_bits));
392	}
393	rro.rro_seqnum = rr->rr_seqnum;
394
395	return (0);
396}
397
398static void
399rr_command_input(int len, struct icmp6_router_renum *rr,
400	struct in6_addr *from, struct in6_addr *dst)
401{
402	/* rr_command validity check */
403	if (rr_command_check(len, rr, from, dst))
404		goto failed;
405	if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
406	    ICMP6_RR_FLAGS_TEST)
407		return;
408
409	/* do router renumbering */
410	if (do_rr(len, rr))
411		goto failed;
412
413	/* update segnum */
414	RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
415
416	return;
417
418    failed:
419	syslog(LOG_ERR, "<%s> received RR was invalid", __func__);
420	return;
421}
422
423void
424rr_input(int len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
425	struct sockaddr_in6 *from, struct in6_addr *dst)
426{
427	u_char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
428
429	syslog(LOG_DEBUG,
430	    "<%s> RR received from %s to %s on %s",
431	    __func__,
432	    inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[0] ,sizeof(ntopbuf[0])),
433	    inet_ntop(AF_INET6, &dst, ntopbuf[1], sizeof(ntopbuf[1])),
434	    if_indextoname(pi->ipi6_ifindex, ifnamebuf));
435
436	/* packet validation based on Section 4.1 of RFC2894 */
437	if ((size_t)len < sizeof(struct icmp6_router_renum)) {
438		syslog(LOG_NOTICE,
439		    "<%s>: RR short message (size %d) from %s to %s on %s",
440		    __func__, len,
441		    inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[0],
442			sizeof(ntopbuf[0])),
443		    inet_ntop(AF_INET6, &dst, ntopbuf[1], sizeof(ntopbuf[1])),
444		    if_indextoname(pi->ipi6_ifindex, ifnamebuf));
445		return;
446	}
447
448	/*
449	 * If the IPv6 destination address is neither an All Routers multicast
450	 * address [AARCH] nor one of the receiving router's unicast addresses,
451	 * the message MUST be discarded and SHOULD be logged to network
452	 * management.
453	 * We rely on the kernel input routine for unicast addresses, and thus
454	 * check multicast destinations only.
455	 */
456	if (IN6_IS_ADDR_MULTICAST(&pi->ipi6_addr) && !IN6_ARE_ADDR_EQUAL(
457	    &sin6_sitelocal_allrouters.sin6_addr, &pi->ipi6_addr)) {
458		syslog(LOG_NOTICE,
459		    "<%s>: RR message with invalid destination (%s) "
460		    "from %s on %s",
461		    __func__,
462		    inet_ntop(AF_INET6, &dst, ntopbuf[0], sizeof(ntopbuf[0])),
463		    inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[1],
464			      sizeof(ntopbuf[1])),
465		    if_indextoname(pi->ipi6_ifindex, ifnamebuf));
466		return;
467	}
468
469	rr_rcvifindex = pi->ipi6_ifindex;
470
471	switch (rr->rr_code) {
472	case ICMP6_ROUTER_RENUMBERING_COMMAND:
473		rr_command_input(len, rr, &from->sin6_addr, dst);
474		/* TODO: send reply msg */
475		break;
476	case ICMP6_ROUTER_RENUMBERING_RESULT:
477		/* RESULT will be processed by rrenumd */
478		break;
479	case ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET:
480		/* TODO: sequence number reset */
481		break;
482	default:
483		syslog(LOG_ERR,	"<%s> received unknown code %d",
484		    __func__, rr->rr_code);
485		break;
486
487	}
488
489	return;
490}
491