1 /* $KAME: rrenum.c,v 1.12 2002/06/10 19:59:47 itojun Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-3-Clause
5 *
6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the project nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33 #include <sys/types.h>
34 #include <sys/param.h>
35 #include <sys/ioctl.h>
36 #include <sys/queue.h>
37 #include <sys/socket.h>
38 #include <sys/sysctl.h>
39
40 #include <net/if.h>
41 #include <net/if_dl.h>
42 #include <net/route.h>
43 #include <netinet/in.h>
44 #include <netinet/in_var.h>
45 #include <netinet/icmp6.h>
46
47 #include <arpa/inet.h>
48
49 #include <errno.h>
50 #include <netdb.h>
51 #include <string.h>
52 #include <stdlib.h>
53 #include <time.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
rr_pco_check(int len,struct rr_pco_match * rpm)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, rpu->rpu_keeplen,
135 rpu->rpu_uselen + rpu->rpu_keeplen);
136 return (1);
137 }
138 }
139 return (0);
140 }
141
142 static void
do_use_prefix(int len,struct rr_pco_match * rpm,struct in6_rrenumreq * irr,int ifindex)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 ifinfo *ifi;
149 struct prefix *pfx;
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 ?
190 0 : 1;
191 irr->irr_raf_auto =
192 (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ?
193 0 : 1;
194 irr->irr_rrf_decrvalid =
195 (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME) == 0 ?
196 0 : 1;
197 irr->irr_rrf_decrprefd =
198 (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME) == 0 ?
199 0 : 1;
200 irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
201 irr->irr_useprefix.sin6_family = AF_INET6;
202 irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
203
204 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
205 errno != EADDRNOTAVAIL)
206 syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
207 strerror(errno));
208
209 /* very adhoc: should be rewritten */
210 if (rpm->rpm_code == RPM_PCO_CHANGE &&
211 IN6_ARE_ADDR_EQUAL(&rpm->rpm_prefix, &rpu->rpu_prefix) &&
212 rpm->rpm_matchlen == rpu->rpu_uselen &&
213 rpu->rpu_uselen == rpu->rpu_keeplen) {
214 ifi = if_indextoifinfo(ifindex);
215 if (ifi == NULL || ifi->ifi_rainfo == NULL)
216 continue; /* non-advertising IF */
217 rai = ifi->ifi_rainfo;
218
219 TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) {
220 struct timespec now;
221
222 if (prefix_match(&pfx->pfx_prefix,
223 pfx->pfx_prefixlen, &rpm->rpm_prefix,
224 rpm->rpm_matchlen)) {
225 /* change parameters */
226 pfx->pfx_validlifetime =
227 ntohl(rpu->rpu_vltime);
228 pfx->pfx_preflifetime =
229 ntohl(rpu->rpu_pltime);
230 if (irr->irr_rrf_decrvalid) {
231 clock_gettime(CLOCK_MONOTONIC_FAST,
232 &now);
233 pfx->pfx_vltimeexpire =
234 now.tv_sec +
235 pfx->pfx_validlifetime;
236 } else
237 pfx->pfx_vltimeexpire = 0;
238 if (irr->irr_rrf_decrprefd) {
239 clock_gettime(CLOCK_MONOTONIC_FAST,
240 &now);
241 pfx->pfx_pltimeexpire =
242 now.tv_sec +
243 pfx->pfx_preflifetime;
244 } else
245 pfx->pfx_pltimeexpire = 0;
246 }
247 }
248 }
249 }
250 }
251
252 /*
253 * process a Prefix Control Operation(PCO).
254 * return 0 on success, 1 on failure
255 */
256 static int
do_pco(struct icmp6_router_renum * rr,int len,struct rr_pco_match * rpm)257 do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
258 {
259 int ifindex = 0;
260 struct in6_rrenumreq irr;
261 struct ifinfo *ifi;
262
263 if ((rr_pco_check(len, rpm) != 0))
264 return (1);
265
266 if (s == -1 && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
267 syslog(LOG_ERR, "<%s> socket: %s", __func__,
268 strerror(errno));
269 exit(1);
270 }
271
272 memset(&irr, 0, sizeof(irr));
273 irr.irr_origin = PR_ORIG_RR;
274 irr.irr_m_len = rpm->rpm_matchlen;
275 irr.irr_m_minlen = rpm->rpm_minlen;
276 irr.irr_m_maxlen = rpm->rpm_maxlen;
277 irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
278 irr.irr_matchprefix.sin6_family = AF_INET6;
279 irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
280
281 while (if_indextoname(++ifindex, irr.irr_name)) {
282 ifi = if_indextoifinfo(ifindex);
283 if (ifi == NULL) {
284 syslog(LOG_ERR, "<%s> ifindex not found.",
285 __func__);
286 return (1);
287 }
288 /*
289 * if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and
290 * IFF_UP is off, the interface is not applied
291 */
292 if ((rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) == 0 &&
293 (ifi->ifi_flags & IFF_UP) == 0)
294 continue;
295 /* TODO: interface scope check */
296 do_use_prefix(len, rpm, &irr, ifindex);
297 }
298 if (errno == ENXIO)
299 return (0);
300 else if (errno) {
301 syslog(LOG_ERR, "<%s> if_indextoname: %s", __func__,
302 strerror(errno));
303 return (1);
304 }
305 return (0);
306 }
307
308 /*
309 * call do_pco() for each Prefix Control Operations(PCOs) in a received
310 * Router Renumbering Command packet.
311 * return 0 on success, 1 on failure
312 */
313 static int
do_rr(int len,struct icmp6_router_renum * rr)314 do_rr(int len, struct icmp6_router_renum *rr)
315 {
316 struct rr_pco_match *rpm;
317 char *cp, *lim;
318
319 lim = (char *)rr + len;
320 cp = (char *)(rr + 1);
321 len -= sizeof(struct icmp6_router_renum);
322
323 update_ifinfo(&ifilist, UPDATE_IFINFO_ALL);
324
325 while (cp < lim) {
326 int rpmlen;
327
328 rpm = (struct rr_pco_match *)cp;
329 if ((size_t)len < sizeof(struct rr_pco_match)) {
330 tooshort:
331 syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
332 "garbage at end of pkt?", __func__, len);
333 return (1);
334 }
335 rpmlen = rpm->rpm_len << 3;
336 if (len < rpmlen)
337 goto tooshort;
338
339 if (do_pco(rr, rpmlen, rpm)) {
340 syslog(LOG_WARNING, "<%s> invalid PCO", __func__);
341 goto next;
342 }
343
344 next:
345 cp += rpmlen;
346 len -= rpmlen;
347 }
348
349 return (0);
350 }
351
352 /*
353 * check validity of a router renumbering command packet
354 * return 0 on success, 1 on failure
355 */
356 static int
rr_command_check(int len,struct icmp6_router_renum * rr,struct in6_addr * from,struct in6_addr * dst)357 rr_command_check(int len, struct icmp6_router_renum *rr, struct in6_addr *from,
358 struct in6_addr *dst)
359 {
360 u_char ntopbuf[INET6_ADDRSTRLEN];
361
362 /* omit rr minimal length check. hope kernel have done it. */
363 /* rr_command length check */
364 if ((size_t)len < (sizeof(struct icmp6_router_renum) +
365 sizeof(struct rr_pco_match))) {
366 syslog(LOG_ERR, "<%s> rr_command len %d is too short",
367 __func__, len);
368 return (1);
369 }
370
371 /* destination check. only for multicast. omit unicast check. */
372 if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
373 !IN6_IS_ADDR_MC_SITELOCAL(dst)) {
374 syslog(LOG_ERR, "<%s> dst mcast addr %s is illegal",
375 __func__,
376 inet_ntop(AF_INET6, dst, ntopbuf, sizeof(ntopbuf)));
377 return (1);
378 }
379
380 /* seqnum and segnum check */
381 if (rro.rro_seqnum > rr->rr_seqnum) {
382 syslog(LOG_WARNING,
383 "<%s> rcvd old seqnum %d from %s",
384 __func__, (u_int32_t)ntohl(rr->rr_seqnum),
385 inet_ntop(AF_INET6, from, ntopbuf, sizeof(ntopbuf)));
386 return (1);
387 }
388 if (rro.rro_seqnum == rr->rr_seqnum &&
389 (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
390 RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
391 if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
392 syslog(LOG_WARNING,
393 "<%s> rcvd duped segnum %d from %s",
394 __func__, rr->rr_segnum, inet_ntop(AF_INET6, from,
395 ntopbuf, sizeof(ntopbuf)));
396 return (0);
397 }
398
399 /* update seqnum */
400 if (rro.rro_seqnum != rr->rr_seqnum) {
401 /* then must be "<" */
402
403 /* init rro_segnum_bits */
404 memset(rro.rro_segnum_bits, 0,
405 sizeof(rro.rro_segnum_bits));
406 }
407 rro.rro_seqnum = rr->rr_seqnum;
408
409 return (0);
410 }
411
412 static void
rr_command_input(int len,struct icmp6_router_renum * rr,struct in6_addr * from,struct in6_addr * dst)413 rr_command_input(int len, struct icmp6_router_renum *rr,
414 struct in6_addr *from, struct in6_addr *dst)
415 {
416 /* rr_command validity check */
417 if (rr_command_check(len, rr, from, dst))
418 goto failed;
419 if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
420 ICMP6_RR_FLAGS_TEST)
421 return;
422
423 /* do router renumbering */
424 if (do_rr(len, rr))
425 goto failed;
426
427 /* update segnum */
428 RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
429
430 return;
431
432 failed:
433 syslog(LOG_ERR, "<%s> received RR was invalid", __func__);
434 }
435
436 void
rr_input(int len,struct icmp6_router_renum * rr,struct in6_pktinfo * pi,struct sockaddr_in6 * from,struct in6_addr * dst)437 rr_input(int len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
438 struct sockaddr_in6 *from, struct in6_addr *dst)
439 {
440 u_char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
441
442 syslog(LOG_DEBUG,
443 "<%s> RR received from %s to %s on %s",
444 __func__,
445 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[0] ,sizeof(ntopbuf[0])),
446 inet_ntop(AF_INET6, &dst, ntopbuf[1], sizeof(ntopbuf[1])),
447 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
448
449 /* packet validation based on Section 4.1 of RFC2894 */
450 if ((size_t)len < sizeof(struct icmp6_router_renum)) {
451 syslog(LOG_NOTICE,
452 "<%s>: RR short message (size %d) from %s to %s on %s",
453 __func__, len,
454 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[0],
455 sizeof(ntopbuf[0])),
456 inet_ntop(AF_INET6, &dst, ntopbuf[1], sizeof(ntopbuf[1])),
457 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
458 return;
459 }
460
461 /*
462 * If the IPv6 destination address is neither an All Routers multicast
463 * address [AARCH] nor one of the receiving router's unicast addresses,
464 * the message MUST be discarded and SHOULD be logged to network
465 * management.
466 * We rely on the kernel input routine for unicast addresses, and thus
467 * check multicast destinations only.
468 */
469 if (IN6_IS_ADDR_MULTICAST(&pi->ipi6_addr) && !IN6_ARE_ADDR_EQUAL(
470 &sin6_sitelocal_allrouters.sin6_addr, &pi->ipi6_addr)) {
471 syslog(LOG_NOTICE,
472 "<%s>: RR message with invalid destination (%s) "
473 "from %s on %s",
474 __func__,
475 inet_ntop(AF_INET6, &dst, ntopbuf[0], sizeof(ntopbuf[0])),
476 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[1],
477 sizeof(ntopbuf[1])),
478 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
479 return;
480 }
481
482 rr_rcvifindex = pi->ipi6_ifindex;
483
484 switch (rr->rr_code) {
485 case ICMP6_ROUTER_RENUMBERING_COMMAND:
486 rr_command_input(len, rr, &from->sin6_addr, dst);
487 /* TODO: send reply msg */
488 break;
489 case ICMP6_ROUTER_RENUMBERING_RESULT:
490 /* RESULT will be processed by rrenumd */
491 break;
492 case ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET:
493 /* TODO: sequence number reset */
494 break;
495 default:
496 syslog(LOG_ERR, "<%s> received unknown code %d",
497 __func__, rr->rr_code);
498 break;
499
500 }
501 }
502