xref: /dragonfly/usr.sbin/rtadvd/rrenum.c (revision 33311965) 
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  */
33 #include <sys/types.h>
34 #include <sys/param.h>
35 #include <sys/ioctl.h>
36 #include <sys/socket.h>
37 #include <sys/sysctl.h>
38 
39 #include <net/if.h>
40 #if defined(__DragonFly__)
41 #include <net/if_var.h>
42 #endif /* __DragonFly__ */
43 #include <net/route.h>
44 #include <netinet/in.h>
45 #include <netinet/in_var.h>
46 #include <netinet/icmp6.h>
47 
48 #include <arpa/inet.h>
49 
50 #include <errno.h>
51 #include <string.h>
52 #include <stdlib.h>
53 #include <syslog.h>
54 #include "rtadvd.h"
55 #include "rrenum.h"
56 #include "if.h"
57 
58 #define	RR_ISSET_SEGNUM(segnum_bits, segnum) \
59 	((((segnum_bits)[(segnum) >> 5]) & (1 << ((segnum) & 31))) != 0)
60 #define	RR_SET_SEGNUM(segnum_bits, segnum) \
61 	(((segnum_bits)[(segnum) >> 5]) |= (1 << ((segnum) & 31)))
62 
63 struct rr_operation {
64 	u_long	rro_seqnum;
65 	u_long	rro_segnum_bits[8];
66 };
67 
68 static struct rr_operation rro;
69 static int rr_rcvifindex;
70 static int rrcmd2pco[RPM_PCO_MAX] = {
71 	0,
72 	SIOCAIFPREFIX_IN6,
73 	SIOCCIFPREFIX_IN6,
74 	SIOCSGIFPREFIX_IN6
75 };
76 static int s = -1;
77 
78 /*
79  * Check validity of a Prefix Control Operation(PCO).
80  * Return 0 on success, 1 on failure.
81  */
82 static int
83 rr_pco_check(int len, struct rr_pco_match *rpm)
84 {
85 	struct rr_pco_use *rpu, *rpulim;
86 	int checklen;
87 
88 	/* rpm->rpm_len must be (4N * 3) as router-renum-05.txt */
89 	if ((rpm->rpm_len - 3) < 0 || /* must be at least 3 */
90 	    (rpm->rpm_len - 3) & 0x3) { /* must be multiple of 4 */
91 		syslog(LOG_WARNING, "<%s> rpm_len %d is not 4N * 3",
92 		       __func__, rpm->rpm_len);
93 		return 1;
94 	}
95 	/* rpm->rpm_code must be valid value */
96 	switch(rpm->rpm_code) {
97 	case RPM_PCO_ADD:
98 	case RPM_PCO_CHANGE:
99 	case RPM_PCO_SETGLOBAL:
100 		break;
101 	default:
102 		syslog(LOG_WARNING, "<%s> unknown rpm_code %d", __func__,
103 		       rpm->rpm_code);
104 		return 1;
105 	}
106 	/* rpm->rpm_matchlen must be 0 to 128 inclusive */
107 	if (rpm->rpm_matchlen > 128) {
108 		syslog(LOG_WARNING, "<%s> rpm_matchlen %d is over 128",
109 		       __func__, rpm->rpm_matchlen);
110 		return 1;
111 	}
112 
113 	/*
114 	 * rpu->rpu_uselen, rpu->rpu_keeplen, and sum of them must be
115 	 * between 0 and 128 inclusive
116 	 */
117 	for (rpu = (struct rr_pco_use *)(rpm + 1),
118 	     rpulim = (struct rr_pco_use *)((char *)rpm + len);
119 	     rpu < rpulim;
120 	     rpu += 1) {
121 		checklen = rpu->rpu_uselen;
122 		checklen += rpu->rpu_keeplen;
123 		/*
124 		 * omit these check, because either of rpu_uselen
125 		 * and rpu_keeplen is unsigned char
126 		 *  (128 > rpu_uselen > 0)
127 		 *  (128 > rpu_keeplen > 0)
128 		 *  (rpu_uselen + rpu_keeplen > 0)
129 		 */
130 		if (checklen > 128) {
131 			syslog(LOG_WARNING, "<%s> sum of rpu_uselen %d and"
132 			       " rpu_keeplen %d is %d(over 128)",
133 			       __func__, rpu->rpu_uselen,
134 			       rpu->rpu_keeplen,
135 			       rpu->rpu_uselen + rpu->rpu_keeplen);
136 			return 1;
137 		}
138 	}
139 	return 0;
140 }
141 
142 static void
143 do_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 prefix *pp;
149 
150 	rpu = (struct rr_pco_use *)(rpm + 1);
151 	rpulim = (struct rr_pco_use *)((char *)rpm + len);
152 
153 	if (rpu == rpulim) {	/* no use prefix */
154 		if (rpm->rpm_code == RPM_PCO_ADD)
155 			return;
156 
157 		irr->irr_u_uselen = 0;
158 		irr->irr_u_keeplen = 0;
159 		irr->irr_raf_mask_onlink = 0;
160 		irr->irr_raf_mask_auto = 0;
161 		irr->irr_vltime = 0;
162 		irr->irr_pltime = 0;
163 		memset(&irr->irr_flags, 0, sizeof(irr->irr_flags));
164 		irr->irr_useprefix.sin6_len = 0; /* let it mean, no addition */
165 		irr->irr_useprefix.sin6_family = 0;
166 		irr->irr_useprefix.sin6_addr = in6addr_any;
167 		if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
168 		    errno != EADDRNOTAVAIL)
169 			syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
170 			       strerror(errno));
171 		return;
172 	}
173 
174 	for (rpu = (struct rr_pco_use *)(rpm + 1),
175 	     rpulim = (struct rr_pco_use *)((char *)rpm + len);
176 	     rpu < rpulim;
177 	     rpu += 1) {
178 		/* init in6_rrenumreq fields */
179 		irr->irr_u_uselen = rpu->rpu_uselen;
180 		irr->irr_u_keeplen = rpu->rpu_keeplen;
181 		irr->irr_raf_mask_onlink =
182 			(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK) == 0 ? 0 : 1;
183 		irr->irr_raf_mask_auto =
184 			(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_AUTO);
185 		irr->irr_vltime = ntohl(rpu->rpu_vltime);
186 		irr->irr_pltime = ntohl(rpu->rpu_pltime);
187 		irr->irr_raf_onlink =
188 			(rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK) == 0 ? 0 : 1;
189 		irr->irr_raf_auto =
190 			(rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ? 0 : 1;
191 		irr->irr_rrf_decrvalid =
192 			(rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME) == 0 ? 0 : 1;
193 		irr->irr_rrf_decrprefd =
194 			(rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME) == 0 ? 0 : 1;
195 		irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
196 		irr->irr_useprefix.sin6_family = AF_INET6;
197 		irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
198 
199 		if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
200 		    errno != EADDRNOTAVAIL)
201 			syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
202 			       strerror(errno));
203 
204 		/* very adhoc: should be rewritten */
205 		if (rpm->rpm_code == RPM_PCO_CHANGE &&
206 		    IN6_ARE_ADDR_EQUAL(&rpm->rpm_prefix, &rpu->rpu_prefix) &&
207 		    rpm->rpm_matchlen == rpu->rpu_uselen &&
208 		    rpu->rpu_uselen == rpu->rpu_keeplen) {
209 			if ((rai = if_indextorainfo(ifindex)) == NULL)
210 				continue; /* non-advertising IF */
211 
212 			for (pp = rai->prefix.next; pp != &rai->prefix;
213 			     pp = pp->next) {
214 				struct timeval now;
215 
216 				if (prefix_match(&pp->prefix, pp->prefixlen,
217 						 &rpm->rpm_prefix,
218 						 rpm->rpm_matchlen)) {
219 					/* change parameters */
220 					pp->validlifetime = ntohl(rpu->rpu_vltime);
221 					pp->preflifetime = ntohl(rpu->rpu_pltime);
222 					if (irr->irr_rrf_decrvalid) {
223 						gettimeofday(&now, 0);
224 						pp->vltimeexpire =
225 							now.tv_sec + pp->validlifetime;
226 					} else
227 						pp->vltimeexpire = 0;
228 					if (irr->irr_rrf_decrprefd) {
229 						gettimeofday(&now, 0);
230 						pp->pltimeexpire =
231 							now.tv_sec + pp->preflifetime;
232 					} else
233 						pp->pltimeexpire = 0;
234 				}
235 			}
236 		}
237 	}
238 }
239 
240 /*
241  * process a Prefix Control Operation(PCO).
242  * return 0 on success, 1 on failure
243  */
244 static int
245 do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
246 {
247 	int ifindex = 0;
248 	struct in6_rrenumreq irr;
249 
250 	if ((rr_pco_check(len, rpm) != 0))
251 		return 1;
252 
253 	if (s == -1 && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
254 		syslog(LOG_ERR, "<%s> socket: %s", __func__,
255 		       strerror(errno));
256 		exit(1);
257 	}
258 
259 	memset(&irr, 0, sizeof(irr));
260 	irr.irr_origin = PR_ORIG_RR;
261 	irr.irr_m_len = rpm->rpm_matchlen;
262 	irr.irr_m_minlen = rpm->rpm_minlen;
263 	irr.irr_m_maxlen = rpm->rpm_maxlen;
264 	irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
265 	irr.irr_matchprefix.sin6_family = AF_INET6;
266 	irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
267 
268 	while (if_indextoname(++ifindex, irr.irr_name)) {
269 		/*
270 		 * if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and IFF_UP is off,
271 		 * the interface is not applied
272 		 */
273 		if ((rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) == 0 &&
274 		    (iflist[ifindex]->ifm_flags & IFF_UP) == 0)
275 			continue;
276 		/* TODO: interface scope check */
277 		do_use_prefix(len, rpm, &irr, ifindex);
278 	}
279 	if (errno == ENXIO)
280 		return 0;
281 	else if (errno) {
282 		syslog(LOG_ERR, "<%s> if_indextoname: %s", __func__,
283 		       strerror(errno));
284 		return 1;
285 	}
286 	return 0;
287 }
288 
289 /*
290  * call do_pco() for each Prefix Control Operations(PCOs) in a received
291  * Router Renumbering Command packet.
292  * return 0 on success, 1 on failure
293  */
294 static int
295 do_rr(int len, struct icmp6_router_renum *rr)
296 {
297 	struct rr_pco_match *rpm;
298 	char *cp, *lim;
299 
300 	lim = (char *)rr + len;
301 	cp = (char *)(rr + 1);
302 	len -= sizeof(struct icmp6_router_renum);
303 
304 	/* get iflist block from kernel again, to get up-to-date information */
305 	init_iflist();
306 
307 	while (cp < lim) {
308 		int rpmlen;
309 
310 		rpm = (struct rr_pco_match *)cp;
311 		if (len < sizeof(struct rr_pco_match)) {
312 		    tooshort:
313 			syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
314 			       "garbage at end of pkt?", __func__, len);
315 			return 1;
316 		}
317 		rpmlen = rpm->rpm_len << 3;
318 		if (len < rpmlen)
319 			goto tooshort;
320 
321 		if (do_pco(rr, rpmlen, rpm)) {
322 			syslog(LOG_WARNING, "<%s> invalid PCO", __func__);
323 			goto next;
324 		}
325 
326 	    next:
327 		cp += rpmlen;
328 		len -= rpmlen;
329 	}
330 
331 	return 0;
332 }
333 
334 /*
335  * check validity of a router renumbering command packet
336  * return 0 on success, 1 on failure
337  */
338 static int
339 rr_command_check(int len, struct icmp6_router_renum *rr, struct in6_addr *from,
340 		 struct in6_addr *dst)
341 {
342 	u_char ntopbuf[INET6_ADDRSTRLEN];
343 
344 	/* omit rr minimal length check. hope kernel have done it. */
345 	/* rr_command length check */
346 	if (len < (sizeof(struct icmp6_router_renum) +
347 		   sizeof(struct rr_pco_match))) {
348 		syslog(LOG_ERR,	"<%s> rr_command len %d is too short",
349 		       __func__, len);
350 		return 1;
351 	}
352 
353 	/* destination check. only for multicast. omit unicast check. */
354 	if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
355 	    !IN6_IS_ADDR_MC_SITELOCAL(dst)) {
356 		syslog(LOG_ERR,	"<%s> dst mcast addr %s is illegal",
357 		       __func__,
358 		       inet_ntop(AF_INET6, dst, ntopbuf, INET6_ADDRSTRLEN));
359 		return 1;
360 	}
361 
362 	/* seqnum and segnum check */
363 	if (rro.rro_seqnum > rr->rr_seqnum) {
364 		syslog(LOG_WARNING,
365 		       "<%s> rcvd old seqnum %d from %s",
366 		       __func__, (u_int32_t)ntohl(rr->rr_seqnum),
367 		       inet_ntop(AF_INET6, from, ntopbuf, INET6_ADDRSTRLEN));
368 		return 1;
369 	}
370 	if (rro.rro_seqnum == rr->rr_seqnum &&
371 	    (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
372 	    RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
373 		if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
374 			syslog(LOG_WARNING,
375 			       "<%s> rcvd duped segnum %d from %s",
376 			       __func__, rr->rr_segnum,
377 			       inet_ntop(AF_INET6, from, ntopbuf,
378 					 INET6_ADDRSTRLEN));
379 		return 0;
380 	}
381 
382 	/* update seqnum */
383 	if (rro.rro_seqnum != rr->rr_seqnum) {
384 		/* then must be "<" */
385 
386 		/* init rro_segnum_bits */
387 		memset(rro.rro_segnum_bits, 0,
388 		       sizeof(rro.rro_segnum_bits));
389 	}
390 	rro.rro_seqnum = rr->rr_seqnum;
391 
392 	return 0;
393 }
394 
395 static void
396 rr_command_input(int len, struct icmp6_router_renum *rr,
397 		 struct in6_addr *from, struct in6_addr *dst)
398 {
399 	/* rr_command validity check */
400 	if (rr_command_check(len, rr, from, dst))
401 		goto failed;
402 	if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
403 	    ICMP6_RR_FLAGS_TEST)
404 		return;
405 
406 	/* do router renumbering */
407 	if (do_rr(len, rr)) {
408 		goto failed;
409 	}
410 
411 	/* update segnum */
412 	RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
413 
414 	return;
415 
416     failed:
417 	syslog(LOG_ERR, "<%s> received RR was invalid", __func__);
418 	return;
419 }
420 
421 void
422 rr_input(int len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
423 	 struct sockaddr_in6 *from, struct in6_addr *dst)
424 {
425 	u_char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
426 
427 	syslog(LOG_DEBUG,
428 	       "<%s> RR received from %s to %s on %s",
429 	       __func__,
430 	       inet_ntop(AF_INET6, &from->sin6_addr,
431 			 ntopbuf[0], INET6_ADDRSTRLEN),
432 	       inet_ntop(AF_INET6, &dst, ntopbuf[1], INET6_ADDRSTRLEN),
433 	       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
434 
435 	/* packet validation based on Section 4.1 of RFC2894 */
436 	if (len < sizeof(struct icmp6_router_renum)) {
437 		syslog(LOG_NOTICE,
438 		       "<%s>: RR short message (size %d) from %s to %s on %s",
439 		       __func__, len,
440 		       inet_ntop(AF_INET6, &from->sin6_addr,
441 				 ntopbuf[0], INET6_ADDRSTRLEN),
442 		       inet_ntop(AF_INET6, &dst, ntopbuf[1], INET6_ADDRSTRLEN),
443 		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
444 		return;
445 	}
446 
447 	/*
448 	 * If the IPv6 destination address is neither an All Routers multicast
449 	 * address [AARCH] nor one of the receiving router's unicast addresses,
450 	 * the message MUST be discarded and SHOULD be logged to network
451 	 * management.
452 	 * We rely on the kernel input routine for unicast addresses, and thus
453 	 * check multicast destinations only.
454 	 */
455 	if (IN6_IS_ADDR_MULTICAST(&pi->ipi6_addr) &&
456 	    !IN6_ARE_ADDR_EQUAL(&in6a_site_allrouters, &pi->ipi6_addr)) {
457 		syslog(LOG_NOTICE,
458 		       "<%s>: RR message with invalid destination (%s) "
459 		       "from %s on %s",
460 		       __func__,
461 		       inet_ntop(AF_INET6, &dst, ntopbuf[0], INET6_ADDRSTRLEN),
462 		       inet_ntop(AF_INET6, &from->sin6_addr,
463 				 ntopbuf[1], INET6_ADDRSTRLEN),
464 		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
465 		return;
466 	}
467 
468 	rr_rcvifindex = pi->ipi6_ifindex;
469 
470 	switch (rr->rr_code) {
471 	case ICMP6_ROUTER_RENUMBERING_COMMAND:
472 		rr_command_input(len, rr, &from->sin6_addr, dst);
473 		/* TODO: send reply msg */
474 		break;
475 	case ICMP6_ROUTER_RENUMBERING_RESULT:
476 		/* RESULT will be processed by rrenumd */
477 		break;
478 	case ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET:
479 		/* TODO: sequence number reset */
480 		break;
481 	default:
482 		syslog(LOG_ERR,	"<%s> received unknown code %d",
483 		       __func__, rr->rr_code);
484 		break;
485 
486 	}
487 
488 	return;
489 }
490