xref: /dragonfly/usr.sbin/rtadvd/rrenum.c (revision 0bb9290e) 
1 /*	$KAME: rrenum.c,v 1.10 2001/01/21 15:32:16 itojun Exp $	*/
2 
3 /*
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  * $FreeBSD: src/usr.sbin/rtadvd/rrenum.c,v 1.2.2.2 2001/07/03 11:02:14 ume Exp $
32  * $DragonFly: src/usr.sbin/rtadvd/rrenum.c,v 1.4 2005/02/17 14:00:10 joerg Exp $
33  */
34 #include <sys/types.h>
35 #include <sys/param.h>
36 #include <sys/ioctl.h>
37 #include <sys/socket.h>
38 #include <sys/sysctl.h>
39 
40 #include <net/if.h>
41 #if defined(__DragonFly__)
42 #include <net/if_var.h>
43 #endif /* __DragonFly__ */
44 #include <net/route.h>
45 #include <netinet/in.h>
46 #include <netinet/in_var.h>
47 #include <netinet/icmp6.h>
48 
49 #include <arpa/inet.h>
50 
51 #include <errno.h>
52 #include <string.h>
53 #include <stdlib.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 
64 struct rr_operation {
65 	u_long	rro_seqnum;
66 	u_long	rro_segnum_bits[8];
67 };
68 
69 static struct rr_operation rro;
70 static int rr_rcvifindex;
71 static int rrcmd2pco[RPM_PCO_MAX] = {
72 	0,
73 	SIOCAIFPREFIX_IN6,
74 	SIOCCIFPREFIX_IN6,
75 	SIOCSGIFPREFIX_IN6
76 };
77 static int s = -1;
78 
79 /*
80  * Check validity of a Prefix Control Operation(PCO).
81  * Return 0 on success, 1 on failure.
82  */
83 static int
84 rr_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,
135 			       rpu->rpu_keeplen,
136 			       rpu->rpu_uselen + rpu->rpu_keeplen);
137 			return 1;
138 		}
139 	}
140 	return 0;
141 }
142 
143 static void
144 do_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 prefix *pp;
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 ? 0 : 1;
190 		irr->irr_raf_auto =
191 			(rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ? 0 : 1;
192 		irr->irr_rrf_decrvalid =
193 			(rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME) == 0 ? 0 : 1;
194 		irr->irr_rrf_decrprefd =
195 			(rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME) == 0 ? 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 			for (pp = rai->prefix.next; pp != &rai->prefix;
214 			     pp = pp->next) {
215 				struct timeval now;
216 
217 				if (prefix_match(&pp->prefix, pp->prefixlen,
218 						 &rpm->rpm_prefix,
219 						 rpm->rpm_matchlen)) {
220 					/* change parameters */
221 					pp->validlifetime = ntohl(rpu->rpu_vltime);
222 					pp->preflifetime = ntohl(rpu->rpu_pltime);
223 					if (irr->irr_rrf_decrvalid) {
224 						gettimeofday(&now, 0);
225 						pp->vltimeexpire =
226 							now.tv_sec + pp->validlifetime;
227 					} else
228 						pp->vltimeexpire = 0;
229 					if (irr->irr_rrf_decrprefd) {
230 						gettimeofday(&now, 0);
231 						pp->pltimeexpire =
232 							now.tv_sec + pp->preflifetime;
233 					} else
234 						pp->pltimeexpire = 0;
235 				}
236 			}
237 		}
238 	}
239 }
240 
241 /*
242  * process a Prefix Control Operation(PCO).
243  * return 0 on success, 1 on failure
244  */
245 static int
246 do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
247 {
248 	int ifindex = 0;
249 	struct in6_rrenumreq irr;
250 
251 	if ((rr_pco_check(len, rpm) != NULL))
252 		return 1;
253 
254 	if (s == -1 && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
255 		syslog(LOG_ERR, "<%s> socket: %s", __func__,
256 		       strerror(errno));
257 		exit(1);
258 	}
259 
260 	memset(&irr, 0, sizeof(irr));
261 	irr.irr_origin = PR_ORIG_RR;
262 	irr.irr_m_len = rpm->rpm_matchlen;
263 	irr.irr_m_minlen = rpm->rpm_minlen;
264 	irr.irr_m_maxlen = rpm->rpm_maxlen;
265 	irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
266 	irr.irr_matchprefix.sin6_family = AF_INET6;
267 	irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
268 
269 	while (if_indextoname(++ifindex, irr.irr_name)) {
270 		/*
271 		 * if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and IFF_UP is off,
272 		 * the interface is not applied
273 		 */
274 		if ((rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) == 0 &&
275 		    (iflist[ifindex]->ifm_flags & IFF_UP) == 0)
276 			continue;
277 		/* TODO: interface scope check */
278 		do_use_prefix(len, rpm, &irr, ifindex);
279 	}
280 	if (errno == ENXIO)
281 		return 0;
282 	else if (errno) {
283 		syslog(LOG_ERR, "<%s> if_indextoname: %s", __func__,
284 		       strerror(errno));
285 		return 1;
286 	}
287 	return 0;
288 }
289 
290 /*
291  * call do_pco() for each Prefix Control Operations(PCOs) in a received
292  * Router Renumbering Command packet.
293  * return 0 on success, 1 on failure
294  */
295 static int
296 do_rr(int len, struct icmp6_router_renum *rr)
297 {
298 	struct rr_pco_match *rpm;
299 	char *cp, *lim;
300 
301 	lim = (char *)rr + len;
302 	cp = (char *)(rr + 1);
303 	len -= sizeof(struct icmp6_router_renum);
304 
305 	/* get iflist block from kernel again, to get up-to-date information */
306 	init_iflist();
307 
308 	while (cp < lim) {
309 		int rpmlen;
310 
311 		rpm = (struct rr_pco_match *)cp;
312 		if (len < sizeof(struct rr_pco_match)) {
313 		    tooshort:
314 			syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
315 			       "gabage at end of pkt?", __func__, len);
316 			return 1;
317 		}
318 		rpmlen = rpm->rpm_len << 3;
319 		if (len < rpmlen)
320 			goto tooshort;
321 
322 		if (do_pco(rr, rpmlen, rpm)) {
323 			syslog(LOG_WARNING, "<%s> invalid PCO", __func__);
324 			goto next;
325 		}
326 
327 	    next:
328 		cp += rpmlen;
329 		len -= rpmlen;
330 	}
331 
332 	return 0;
333 }
334 
335 /*
336  * check validity of a router renumbering command packet
337  * return 0 on success, 1 on failure
338  */
339 static int
340 rr_command_check(int len, struct icmp6_router_renum *rr, struct in6_addr *from,
341 		 struct in6_addr *dst)
342 {
343 	u_char ntopbuf[INET6_ADDRSTRLEN];
344 
345 	/* omit rr minimal length check. hope kernel have done it. */
346 	/* rr_command length check */
347 	if (len < (sizeof(struct icmp6_router_renum) +
348 		   sizeof(struct rr_pco_match))) {
349 		syslog(LOG_ERR,	"<%s> rr_command len %d is too short",
350 		       __func__, len);
351 		return 1;
352 	}
353 
354 	/* destination check. only for multicast. omit unicast check. */
355 	if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
356 	    !IN6_IS_ADDR_MC_SITELOCAL(dst)) {
357 		syslog(LOG_ERR,	"<%s> dst mcast addr %s is illegal",
358 		       __func__,
359 		       inet_ntop(AF_INET6, dst, ntopbuf, INET6_ADDRSTRLEN));
360 		return 1;
361 	}
362 
363 	/* seqnum and segnum check */
364 	if (rro.rro_seqnum > rr->rr_seqnum) {
365 		syslog(LOG_WARNING,
366 		       "<%s> rcvd old seqnum %d from %s",
367 		       __func__, (u_int32_t)ntohl(rr->rr_seqnum),
368 		       inet_ntop(AF_INET6, from, ntopbuf, INET6_ADDRSTRLEN));
369 		return 1;
370 	}
371 	if (rro.rro_seqnum == rr->rr_seqnum &&
372 	    (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
373 	    RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
374 		if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
375 			syslog(LOG_WARNING,
376 			       "<%s> rcvd duped segnum %d from %s",
377 			       __func__, rr->rr_segnum,
378 			       inet_ntop(AF_INET6, from, ntopbuf,
379 					 INET6_ADDRSTRLEN));
380 		return 0;
381 	}
382 
383 	/* update seqnum */
384 	if (rro.rro_seqnum != rr->rr_seqnum) {
385 		/* then must be "<" */
386 
387 		/* init rro_segnum_bits */
388 		memset(rro.rro_segnum_bits, 0,
389 		       sizeof(rro.rro_segnum_bits));
390 	}
391 	rro.rro_seqnum = rr->rr_seqnum;
392 
393 	return 0;
394 }
395 
396 static void
397 rr_command_input(int len, struct icmp6_router_renum *rr,
398 		 struct in6_addr *from, struct in6_addr *dst)
399 {
400 	/* rr_command validity check */
401 	if (rr_command_check(len, rr, from, dst))
402 		goto failed;
403 	if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
404 	    ICMP6_RR_FLAGS_TEST)
405 		return;
406 
407 	/* do router renumbering */
408 	if (do_rr(len, rr)) {
409 		goto failed;
410 	}
411 
412 	/* update segnum */
413 	RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
414 
415 	return;
416 
417     failed:
418 	syslog(LOG_ERR, "<%s> received RR was invalid", __func__);
419 	return;
420 }
421 
422 void
423 rr_input(int len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
424 	 struct sockaddr_in6 *from, struct in6_addr *dst)
425 {
426 	u_char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
427 
428 	syslog(LOG_DEBUG,
429 	       "<%s> RR received from %s to %s on %s",
430 	       __func__,
431 	       inet_ntop(AF_INET6, &from->sin6_addr,
432 			 ntopbuf[0], INET6_ADDRSTRLEN),
433 	       inet_ntop(AF_INET6, &dst, ntopbuf[1], INET6_ADDRSTRLEN),
434 	       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
435 
436 	/* packet validation based on Section 4.1 of RFC2894 */
437 	if (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,
442 				 ntopbuf[0], INET6_ADDRSTRLEN),
443 		       inet_ntop(AF_INET6, &dst, ntopbuf[1], INET6_ADDRSTRLEN),
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) &&
457 	    !IN6_ARE_ADDR_EQUAL(&in6a_site_allrouters, &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], INET6_ADDRSTRLEN),
463 		       inet_ntop(AF_INET6, &from->sin6_addr,
464 				 ntopbuf[1], INET6_ADDRSTRLEN),
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