1 /* $FreeBSD: stable/10/usr.sbin/rtadvd/rrenum.c 253970 2013-08-05 20:13:02Z hrs $ */
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_dl.h>
40 #include <net/if_var.h>
41 #include <net/route.h>
42 #include <netinet/in.h>
43 #include <netinet/in_var.h>
44 #include <netinet/icmp6.h>
45
46 #include <arpa/inet.h>
47
48 #include <errno.h>
49 #include <netdb.h>
50 #include <string.h>
51 #include <stdlib.h>
52 #include <time.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
rr_pco_check(int len,struct rr_pco_match * rpm)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, rpu->rpu_keeplen,
134 rpu->rpu_uselen + rpu->rpu_keeplen);
135 return (1);
136 }
137 }
138 return (0);
139 }
140
141 static void
do_use_prefix(int len,struct rr_pco_match * rpm,struct in6_rrenumreq * irr,int ifindex)142 do_use_prefix(int len, struct rr_pco_match *rpm,
143 struct in6_rrenumreq *irr, int ifindex)
144 {
145 struct rr_pco_use *rpu, *rpulim;
146 struct rainfo *rai;
147 struct ifinfo *ifi;
148 struct prefix *pfx;
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);
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 ?
189 0 : 1;
190 irr->irr_raf_auto =
191 (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ?
192 0 : 1;
193 irr->irr_rrf_decrvalid =
194 (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME) == 0 ?
195 0 : 1;
196 irr->irr_rrf_decrprefd =
197 (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME) == 0 ?
198 0 : 1;
199 irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
200 irr->irr_useprefix.sin6_family = AF_INET6;
201 irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
202
203 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
204 errno != EADDRNOTAVAIL)
205 syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
206 strerror(errno));
207
208 /* very adhoc: should be rewritten */
209 if (rpm->rpm_code == RPM_PCO_CHANGE &&
210 IN6_ARE_ADDR_EQUAL(&rpm->rpm_prefix, &rpu->rpu_prefix) &&
211 rpm->rpm_matchlen == rpu->rpu_uselen &&
212 rpu->rpu_uselen == rpu->rpu_keeplen) {
213 ifi = if_indextoifinfo(ifindex);
214 if (ifi == NULL || ifi->ifi_rainfo == NULL)
215 continue; /* non-advertising IF */
216 rai = ifi->ifi_rainfo;
217
218 TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) {
219 struct timespec now;
220
221 if (prefix_match(&pfx->pfx_prefix,
222 pfx->pfx_prefixlen, &rpm->rpm_prefix,
223 rpm->rpm_matchlen)) {
224 /* change parameters */
225 pfx->pfx_validlifetime =
226 ntohl(rpu->rpu_vltime);
227 pfx->pfx_preflifetime =
228 ntohl(rpu->rpu_pltime);
229 if (irr->irr_rrf_decrvalid) {
230 clock_gettime(CLOCK_MONOTONIC_FAST,
231 &now);
232 pfx->pfx_vltimeexpire =
233 now.tv_sec +
234 pfx->pfx_validlifetime;
235 } else
236 pfx->pfx_vltimeexpire = 0;
237 if (irr->irr_rrf_decrprefd) {
238 clock_gettime(CLOCK_MONOTONIC_FAST,
239 &now);
240 pfx->pfx_pltimeexpire =
241 now.tv_sec +
242 pfx->pfx_preflifetime;
243 } else
244 pfx->pfx_pltimeexpire = 0;
245 }
246 }
247 }
248 }
249 }
250
251 /*
252 * process a Prefix Control Operation(PCO).
253 * return 0 on success, 1 on failure
254 */
255 static int
do_pco(struct icmp6_router_renum * rr,int len,struct rr_pco_match * rpm)256 do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
257 {
258 int ifindex = 0;
259 struct in6_rrenumreq irr;
260 struct ifinfo *ifi;
261
262 if ((rr_pco_check(len, rpm) != 0))
263 return (1);
264
265 if (s == -1 && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
266 syslog(LOG_ERR, "<%s> socket: %s", __func__,
267 strerror(errno));
268 exit(1);
269 }
270
271 memset(&irr, 0, sizeof(irr));
272 irr.irr_origin = PR_ORIG_RR;
273 irr.irr_m_len = rpm->rpm_matchlen;
274 irr.irr_m_minlen = rpm->rpm_minlen;
275 irr.irr_m_maxlen = rpm->rpm_maxlen;
276 irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
277 irr.irr_matchprefix.sin6_family = AF_INET6;
278 irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
279
280 while (if_indextoname(++ifindex, irr.irr_name)) {
281 ifi = if_indextoifinfo(ifindex);
282 if (ifi == NULL) {
283 syslog(LOG_ERR, "<%s> ifindex not found.",
284 __func__);
285 return (1);
286 }
287 /*
288 * if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and
289 * IFF_UP is off, the interface is not applied
290 */
291 if ((rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) == 0 &&
292 (ifi->ifi_flags & IFF_UP) == 0)
293 continue;
294 /* TODO: interface scope check */
295 do_use_prefix(len, rpm, &irr, ifindex);
296 }
297 if (errno == ENXIO)
298 return (0);
299 else if (errno) {
300 syslog(LOG_ERR, "<%s> if_indextoname: %s", __func__,
301 strerror(errno));
302 return (1);
303 }
304 return (0);
305 }
306
307 /*
308 * call do_pco() for each Prefix Control Operations(PCOs) in a received
309 * Router Renumbering Command packet.
310 * return 0 on success, 1 on failure
311 */
312 static int
do_rr(int len,struct icmp6_router_renum * rr)313 do_rr(int len, struct icmp6_router_renum *rr)
314 {
315 struct rr_pco_match *rpm;
316 char *cp, *lim;
317
318 lim = (char *)rr + len;
319 cp = (char *)(rr + 1);
320 len -= sizeof(struct icmp6_router_renum);
321
322 update_ifinfo(&ifilist, UPDATE_IFINFO_ALL);
323
324 while (cp < lim) {
325 int rpmlen;
326
327 rpm = (struct rr_pco_match *)cp;
328 if ((size_t)len < sizeof(struct rr_pco_match)) {
329 tooshort:
330 syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
331 "garbage at end of pkt?", __func__, len);
332 return (1);
333 }
334 rpmlen = rpm->rpm_len << 3;
335 if (len < rpmlen)
336 goto tooshort;
337
338 if (do_pco(rr, rpmlen, rpm)) {
339 syslog(LOG_WARNING, "<%s> invalid PCO", __func__);
340 goto next;
341 }
342
343 next:
344 cp += rpmlen;
345 len -= rpmlen;
346 }
347
348 return (0);
349 }
350
351 /*
352 * check validity of a router renumbering command packet
353 * return 0 on success, 1 on failure
354 */
355 static int
rr_command_check(int len,struct icmp6_router_renum * rr,struct in6_addr * from,struct in6_addr * dst)356 rr_command_check(int len, struct icmp6_router_renum *rr, struct in6_addr *from,
357 struct in6_addr *dst)
358 {
359 u_char ntopbuf[INET6_ADDRSTRLEN];
360
361 /* omit rr minimal length check. hope kernel have done it. */
362 /* rr_command length check */
363 if ((size_t)len < (sizeof(struct icmp6_router_renum) +
364 sizeof(struct rr_pco_match))) {
365 syslog(LOG_ERR, "<%s> rr_command len %d is too short",
366 __func__, len);
367 return (1);
368 }
369
370 /* destination check. only for multicast. omit unicast check. */
371 if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
372 !IN6_IS_ADDR_MC_SITELOCAL(dst)) {
373 syslog(LOG_ERR, "<%s> dst mcast addr %s is illegal",
374 __func__,
375 inet_ntop(AF_INET6, dst, ntopbuf, sizeof(ntopbuf)));
376 return (1);
377 }
378
379 /* seqnum and segnum check */
380 if (rro.rro_seqnum > rr->rr_seqnum) {
381 syslog(LOG_WARNING,
382 "<%s> rcvd old seqnum %d from %s",
383 __func__, (u_int32_t)ntohl(rr->rr_seqnum),
384 inet_ntop(AF_INET6, from, ntopbuf, sizeof(ntopbuf)));
385 return (1);
386 }
387 if (rro.rro_seqnum == rr->rr_seqnum &&
388 (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
389 RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
390 if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
391 syslog(LOG_WARNING,
392 "<%s> rcvd duped segnum %d from %s",
393 __func__, rr->rr_segnum, inet_ntop(AF_INET6, from,
394 ntopbuf, sizeof(ntopbuf)));
395 return (0);
396 }
397
398 /* update seqnum */
399 if (rro.rro_seqnum != rr->rr_seqnum) {
400 /* then must be "<" */
401
402 /* init rro_segnum_bits */
403 memset(rro.rro_segnum_bits, 0,
404 sizeof(rro.rro_segnum_bits));
405 }
406 rro.rro_seqnum = rr->rr_seqnum;
407
408 return (0);
409 }
410
411 static void
rr_command_input(int len,struct icmp6_router_renum * rr,struct in6_addr * from,struct in6_addr * dst)412 rr_command_input(int len, struct icmp6_router_renum *rr,
413 struct in6_addr *from, struct in6_addr *dst)
414 {
415 /* rr_command validity check */
416 if (rr_command_check(len, rr, from, dst))
417 goto failed;
418 if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
419 ICMP6_RR_FLAGS_TEST)
420 return;
421
422 /* do router renumbering */
423 if (do_rr(len, rr))
424 goto failed;
425
426 /* update segnum */
427 RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
428
429 return;
430
431 failed:
432 syslog(LOG_ERR, "<%s> received RR was invalid", __func__);
433 return;
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 return;
503 }
504