1 /* $KAME: rtsol.c,v 1.27 2003/10/05 00:09:36 itojun Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-3-Clause
5 *
6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7 * Copyright (C) 2011 Hiroki Sato
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the project nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #include <sys/param.h>
36 #include <sys/capsicum.h>
37 #include <sys/queue.h>
38 #include <sys/socket.h>
39 #include <sys/stat.h>
40 #include <sys/uio.h>
41 #include <sys/wait.h>
42
43 #include <net/if.h>
44 #include <net/route.h>
45 #include <net/if_dl.h>
46
47 #define __BSD_VISIBLE 1 /* IN6ADDR_LINKLOCAL_ALLROUTERS_INIT */
48 #include <netinet/in.h>
49 #undef __BSD_VISIBLE
50 #include <netinet/ip6.h>
51 #include <netinet6/ip6_var.h>
52 #include <netinet/icmp6.h>
53
54 #include <arpa/inet.h>
55
56 #include <capsicum_helpers.h>
57 #include <netdb.h>
58 #include <time.h>
59 #include <fcntl.h>
60 #include <unistd.h>
61 #include <stdio.h>
62 #include <time.h>
63 #include <err.h>
64 #include <errno.h>
65 #include <string.h>
66 #include <stdlib.h>
67 #include <syslog.h>
68 #include "rtsold.h"
69
70 static char rsid[IFNAMSIZ + 1 + sizeof(DNSINFO_ORIGIN_LABEL) + 1 + NI_MAXHOST];
71 struct ifinfo_head_t ifinfo_head = TAILQ_HEAD_INITIALIZER(ifinfo_head);
72
73 static void call_script(const char *const *, struct script_msg_head_t *);
74 static size_t dname_labeldec(char *, size_t, const char *);
75 static struct ra_opt *find_raopt(struct rainfo *, int, void *, size_t);
76 static int ra_opt_rdnss_dispatch(struct ifinfo *, struct rainfo *,
77 struct script_msg_head_t *, struct script_msg_head_t *);
78 static char *make_rsid(const char *, const char *, struct rainfo *);
79
80 #define _ARGS_MANAGED managedconf_script, ifi->ifname, rasender
81 #define _ARGS_OTHER otherconf_script, ifi->ifname, rasender
82 #define _ARGS_ALWAYS alwaysconf_script, ifi->ifname, rasender
83 #define _ARGS_RESADD resolvconf_script, "-a", rsid
84 #define _ARGS_RESDEL resolvconf_script, "-d", rsid
85
86 #define CALL_SCRIPT(name, sm_head) do { \
87 const char *const sarg[] = { _ARGS_##name, NULL }; \
88 call_script(sarg, sm_head); \
89 } while (0)
90
91 #define ELM_MALLOC(p, error_action) do { \
92 p = malloc(sizeof(*p)); \
93 if (p == NULL) { \
94 warnmsg(LOG_ERR, __func__, "malloc failed: %s", \
95 strerror(errno)); \
96 error_action; \
97 } \
98 memset(p, 0, sizeof(*p)); \
99 } while (0)
100
101 int
recvsockopen(void)102 recvsockopen(void)
103 {
104 struct icmp6_filter filt;
105 cap_rights_t rights;
106 int on, sock;
107
108 if ((sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
109 warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno));
110 goto fail;
111 }
112
113 /* Provide info about the receiving interface. */
114 on = 1;
115 if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
116 sizeof(on)) < 0) {
117 warnmsg(LOG_ERR, __func__, "setsockopt(IPV6_RECVPKTINFO): %s",
118 strerror(errno));
119 goto fail;
120 }
121
122 /* Include the hop limit from the received header. */
123 on = 1;
124 if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
125 sizeof(on)) < 0) {
126 warnmsg(LOG_ERR, __func__, "setsockopt(IPV6_RECVHOPLIMIT): %s",
127 strerror(errno));
128 goto fail;
129 }
130
131 /* Filter out everything except for Router Advertisements. */
132 ICMP6_FILTER_SETBLOCKALL(&filt);
133 ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
134 if (setsockopt(sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
135 sizeof(filt)) == -1) {
136 warnmsg(LOG_ERR, __func__, "setsockopt(ICMP6_FILTER): %s",
137 strerror(errno));
138 goto fail;
139 }
140
141 cap_rights_init(&rights, CAP_EVENT, CAP_RECV);
142 if (caph_rights_limit(sock, &rights) < 0) {
143 warnmsg(LOG_ERR, __func__, "caph_rights_limit(): %s",
144 strerror(errno));
145 goto fail;
146 }
147
148 return (sock);
149
150 fail:
151 if (sock >= 0)
152 (void)close(sock);
153 return (-1);
154 }
155
156 void
rtsol_input(int sock)157 rtsol_input(int sock)
158 {
159 uint8_t cmsg[CMSG_SPACE(sizeof(struct in6_pktinfo)) +
160 CMSG_SPACE(sizeof(int))];
161 struct iovec iov;
162 struct msghdr hdr;
163 struct sockaddr_in6 from;
164 char answer[1500], ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
165 int l, ifindex = 0, *hlimp = NULL;
166 ssize_t msglen;
167 struct in6_pktinfo *pi = NULL;
168 struct ifinfo *ifi = NULL;
169 struct ra_opt *rao = NULL;
170 struct icmp6_hdr *icp;
171 struct nd_router_advert *nd_ra;
172 struct cmsghdr *cm;
173 struct rainfo *rai;
174 char *p, *raoptp;
175 struct in6_addr *addr;
176 struct nd_opt_hdr *ndo;
177 struct nd_opt_rdnss *rdnss;
178 struct nd_opt_dnssl *dnssl;
179 size_t len;
180 char nsbuf[INET6_ADDRSTRLEN + 1 + IFNAMSIZ + 1];
181 char dname[NI_MAXHOST];
182 struct timespec lifetime, now;
183 int newent_rai, newent_rao;
184
185 memset(&hdr, 0, sizeof(hdr));
186 hdr.msg_iov = &iov;
187 hdr.msg_iovlen = 1;
188 hdr.msg_name = &from;
189 hdr.msg_namelen = sizeof(from);
190 hdr.msg_control = cmsg;
191 hdr.msg_controllen = sizeof(cmsg);
192
193 iov.iov_base = (caddr_t)answer;
194 iov.iov_len = sizeof(answer);
195
196 if ((msglen = recvmsg(sock, &hdr, 0)) < 0) {
197 warnmsg(LOG_ERR, __func__, "recvmsg: %s", strerror(errno));
198 return;
199 }
200
201 /* Extract control message info. */
202 for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&hdr); cm != NULL;
203 cm = (struct cmsghdr *)CMSG_NXTHDR(&hdr, cm)) {
204 if (cm->cmsg_level == IPPROTO_IPV6 &&
205 cm->cmsg_type == IPV6_PKTINFO &&
206 cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
207 pi = (struct in6_pktinfo *)(void *)(CMSG_DATA(cm));
208 ifindex = pi->ipi6_ifindex;
209 }
210 if (cm->cmsg_level == IPPROTO_IPV6 &&
211 cm->cmsg_type == IPV6_HOPLIMIT &&
212 cm->cmsg_len == CMSG_LEN(sizeof(int)))
213 hlimp = (int *)(void *)CMSG_DATA(cm);
214 }
215
216 if (ifindex == 0) {
217 warnmsg(LOG_ERR, __func__,
218 "failed to get receiving interface");
219 return;
220 }
221 if (hlimp == NULL) {
222 warnmsg(LOG_ERR, __func__,
223 "failed to get receiving hop limit");
224 return;
225 }
226
227 if ((size_t)msglen < sizeof(struct nd_router_advert)) {
228 warnmsg(LOG_INFO, __func__,
229 "packet size(%zd) is too short", msglen);
230 return;
231 }
232
233 icp = (struct icmp6_hdr *)iov.iov_base;
234 if (icp->icmp6_type != ND_ROUTER_ADVERT) {
235 /*
236 * this should not happen because we configured a filter
237 * that only passes RAs on the receiving socket.
238 */
239 warnmsg(LOG_ERR, __func__,
240 "invalid icmp type(%d) from %s on %s", icp->icmp6_type,
241 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
242 sizeof(ntopbuf)),
243 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
244 return;
245 }
246
247 if (icp->icmp6_code != 0) {
248 warnmsg(LOG_INFO, __func__,
249 "invalid icmp code(%d) from %s on %s", icp->icmp6_code,
250 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
251 sizeof(ntopbuf)),
252 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
253 return;
254 }
255
256 if (*hlimp != 255) {
257 warnmsg(LOG_INFO, __func__,
258 "invalid RA with hop limit(%d) from %s on %s",
259 *hlimp,
260 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
261 sizeof(ntopbuf)),
262 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
263 return;
264 }
265
266 if (pi && !IN6_IS_ADDR_LINKLOCAL(&from.sin6_addr)) {
267 warnmsg(LOG_INFO, __func__,
268 "invalid RA with non link-local source from %s on %s",
269 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
270 sizeof(ntopbuf)),
271 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
272 return;
273 }
274
275 /* xxx: more validation? */
276
277 if ((ifi = find_ifinfo(pi->ipi6_ifindex)) == NULL) {
278 warnmsg(LOG_DEBUG, __func__,
279 "received RA from %s on an unexpected IF(%s)",
280 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
281 sizeof(ntopbuf)),
282 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
283 return;
284 }
285
286 warnmsg(LOG_DEBUG, __func__,
287 "received RA from %s on %s, state is %d",
288 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, sizeof(ntopbuf)),
289 ifi->ifname, ifi->state);
290
291 nd_ra = (struct nd_router_advert *)icp;
292
293 /*
294 * Process the "M bit."
295 * If the value of ManagedConfigFlag changes from FALSE to TRUE, the
296 * host should invoke the stateful autoconfiguration protocol,
297 * requesting information.
298 * [RFC 4861 Section 4.2]
299 * XXX ??? [draft-ietf-v6ops-dhcpv6-slaac-problem-07]
300 */
301 if (((nd_ra->nd_ra_flags_reserved) & ND_RA_FLAG_MANAGED) &&
302 !ifi->managedconfig) {
303 const char *rasender = inet_ntop(AF_INET6, &from.sin6_addr,
304 ntopbuf, sizeof(ntopbuf));
305 warnmsg(LOG_DEBUG, __func__,
306 "ManagedConfigFlag on %s is turned on", ifi->ifname);
307 ifi->managedconfig = 1;
308 CALL_SCRIPT(MANAGED, NULL);
309 }
310
311 /*
312 * Process the "O bit."
313 * If the value of OtherConfigFlag changes from FALSE to TRUE, the
314 * host should invoke the stateful autoconfiguration protocol,
315 * requesting information unless the "M bit" was set as well in
316 * which case the "O bit" is redundant.
317 * [RFC 4861 Section 4.2]
318 */
319 if (((nd_ra->nd_ra_flags_reserved) & ND_RA_FLAG_OTHER) &&
320 !ifi->otherconfig) {
321 const char *rasender = inet_ntop(AF_INET6, &from.sin6_addr,
322 ntopbuf, sizeof(ntopbuf));
323 warnmsg(LOG_DEBUG, __func__,
324 "OtherConfigFlag on %s is turned on", ifi->ifname);
325 ifi->otherconfig = 1;
326 if (!ifi->managedconfig)
327 CALL_SCRIPT(OTHER, NULL);
328 }
329
330 /*
331 * "Always" script.
332 */
333 if (!ifi->alwaysconfig) {
334 const char *rasender = inet_ntop(AF_INET6, &from.sin6_addr,
335 ntopbuf, sizeof(ntopbuf));
336 ifi->alwaysconfig = 1;
337 CALL_SCRIPT(ALWAYS, NULL);
338 }
339
340 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
341 newent_rai = 0;
342 rai = find_rainfo(ifi, &from);
343 if (rai == NULL) {
344 ELM_MALLOC(rai, exit(1));
345 rai->rai_ifinfo = ifi;
346 TAILQ_INIT(&rai->rai_ra_opt);
347 rai->rai_saddr.sin6_family = AF_INET6;
348 rai->rai_saddr.sin6_len = sizeof(rai->rai_saddr);
349 memcpy(&rai->rai_saddr.sin6_addr, &from.sin6_addr,
350 sizeof(rai->rai_saddr.sin6_addr));
351 newent_rai = 1;
352 }
353
354 #define RA_OPT_NEXT_HDR(x) (struct nd_opt_hdr *)((char *)(x) + \
355 (((struct nd_opt_hdr *)(x))->nd_opt_len * 8))
356 /* Process RA options. */
357 warnmsg(LOG_DEBUG, __func__, "Processing RA");
358 raoptp = (char *)icp + sizeof(struct nd_router_advert);
359 while (raoptp < (char *)icp + msglen) {
360 ndo = (struct nd_opt_hdr *)raoptp;
361 warnmsg(LOG_DEBUG, __func__, "ndo = %p", raoptp);
362 warnmsg(LOG_DEBUG, __func__, "ndo->nd_opt_type = %d",
363 ndo->nd_opt_type);
364 warnmsg(LOG_DEBUG, __func__, "ndo->nd_opt_len = %d",
365 ndo->nd_opt_len);
366
367 if (ndo->nd_opt_len == 0) {
368 warnmsg(LOG_INFO, __func__, "invalid option length 0.");
369 break;
370 }
371 if ((char *)RA_OPT_NEXT_HDR(raoptp) > (char *)icp + msglen) {
372 warnmsg(LOG_INFO, __func__, "option length overflow.");
373 break;
374 }
375
376 switch (ndo->nd_opt_type) {
377 case ND_OPT_RDNSS:
378 rdnss = (struct nd_opt_rdnss *)raoptp;
379
380 /*
381 * The option header is 8 bytes long and each address
382 * occupies 16 bytes, so the option length must be
383 * greater than or equal to 24 bytes and an odd multiple
384 * of 8 bytes. See section 5.1 in RFC 6106.
385 */
386 if (rdnss->nd_opt_rdnss_len < 3 ||
387 rdnss->nd_opt_rdnss_len % 2 == 0) {
388 warnmsg(LOG_INFO, __func__,
389 "too short RDNSS option in RA from %s "
390 "was ignored.",
391 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
392 sizeof(ntopbuf)));
393 break;
394 }
395
396 addr = (struct in6_addr *)(void *)(raoptp + sizeof(*rdnss));
397 while ((char *)addr < (char *)RA_OPT_NEXT_HDR(raoptp)) {
398 if (inet_ntop(AF_INET6, addr, ntopbuf,
399 sizeof(ntopbuf)) == NULL) {
400 warnmsg(LOG_INFO, __func__,
401 "an invalid address in RDNSS option"
402 " in RA from %s was ignored.",
403 inet_ntop(AF_INET6, &from.sin6_addr,
404 ntopbuf, sizeof(ntopbuf)));
405 addr++;
406 continue;
407 }
408 if (IN6_IS_ADDR_LINKLOCAL(addr))
409 /* XXX: % has to be escaped here */
410 l = snprintf(nsbuf, sizeof(nsbuf),
411 "%s%c%s", ntopbuf,
412 SCOPE_DELIMITER,
413 ifi->ifname);
414 else
415 l = snprintf(nsbuf, sizeof(nsbuf),
416 "%s", ntopbuf);
417 if (l < 0 || (size_t)l >= sizeof(nsbuf)) {
418 warnmsg(LOG_ERR, __func__,
419 "address copying error in "
420 "RDNSS option: %d.", l);
421 addr++;
422 continue;
423 }
424 warnmsg(LOG_DEBUG, __func__, "nsbuf = %s",
425 nsbuf);
426
427 newent_rao = 0;
428 rao = find_raopt(rai, ndo->nd_opt_type, nsbuf,
429 strlen(nsbuf));
430 if (rao == NULL) {
431 ELM_MALLOC(rao, break);
432 rao->rao_type = ndo->nd_opt_type;
433 rao->rao_len = strlen(nsbuf);
434 rao->rao_msg = strdup(nsbuf);
435 if (rao->rao_msg == NULL) {
436 warnmsg(LOG_ERR, __func__,
437 "strdup failed: %s",
438 strerror(errno));
439 free(rao);
440 addr++;
441 continue;
442 }
443 newent_rao = 1;
444 }
445 /* Set expiration timer */
446 memset(&rao->rao_expire, 0,
447 sizeof(rao->rao_expire));
448 memset(&lifetime, 0, sizeof(lifetime));
449 lifetime.tv_sec =
450 ntohl(rdnss->nd_opt_rdnss_lifetime);
451 TS_ADD(&now, &lifetime, &rao->rao_expire);
452
453 if (newent_rao)
454 TAILQ_INSERT_TAIL(&rai->rai_ra_opt,
455 rao, rao_next);
456 addr++;
457 }
458 break;
459 case ND_OPT_DNSSL:
460 dnssl = (struct nd_opt_dnssl *)raoptp;
461
462 /* Optlen sanity check (Section 5.3.1 in RFC 6106) */
463 if (dnssl->nd_opt_dnssl_len < 2) {
464 warnmsg(LOG_INFO, __func__,
465 "too short DNSSL option"
466 "in RA from %s was ignored.",
467 inet_ntop(AF_INET6, &from.sin6_addr,
468 ntopbuf, sizeof(ntopbuf)));
469 break;
470 }
471
472 /*
473 * Ensure NUL-termination in DNSSL in case of
474 * malformed field.
475 */
476 p = (char *)RA_OPT_NEXT_HDR(raoptp);
477 *(p - 1) = '\0';
478
479 p = raoptp + sizeof(*dnssl);
480 while (1 < (len = dname_labeldec(dname, sizeof(dname),
481 p))) {
482 /* length == 1 means empty string */
483 warnmsg(LOG_DEBUG, __func__, "dname = %s",
484 dname);
485
486 newent_rao = 0;
487 rao = find_raopt(rai, ndo->nd_opt_type, dname,
488 strlen(dname));
489 if (rao == NULL) {
490 ELM_MALLOC(rao, break);
491 rao->rao_type = ndo->nd_opt_type;
492 rao->rao_len = strlen(dname);
493 rao->rao_msg = strdup(dname);
494 if (rao->rao_msg == NULL) {
495 warnmsg(LOG_ERR, __func__,
496 "strdup failed: %s",
497 strerror(errno));
498 free(rao);
499 addr++;
500 continue;
501 }
502 newent_rao = 1;
503 }
504 /* Set expiration timer */
505 memset(&rao->rao_expire, 0,
506 sizeof(rao->rao_expire));
507 memset(&lifetime, 0, sizeof(lifetime));
508 lifetime.tv_sec =
509 ntohl(dnssl->nd_opt_dnssl_lifetime);
510 TS_ADD(&now, &lifetime, &rao->rao_expire);
511
512 if (newent_rao)
513 TAILQ_INSERT_TAIL(&rai->rai_ra_opt,
514 rao, rao_next);
515 p += len;
516 }
517 break;
518 default:
519 /* nothing to do for other options */
520 break;
521 }
522 raoptp = (char *)RA_OPT_NEXT_HDR(raoptp);
523 }
524 if (newent_rai)
525 TAILQ_INSERT_TAIL(&ifi->ifi_rainfo, rai, rai_next);
526
527 ra_opt_handler(ifi);
528 ifi->racnt++;
529
530 switch (ifi->state) {
531 case IFS_IDLE: /* should be ignored */
532 case IFS_DELAY: /* right? */
533 break;
534 case IFS_PROBE:
535 ifi->state = IFS_IDLE;
536 ifi->probes = 0;
537 rtsol_timer_update(ifi);
538 break;
539 }
540 }
541
542 static char resstr_ns_prefix[] = "nameserver ";
543 static char resstr_sh_prefix[] = "search ";
544 static char resstr_nl[] = "\n";
545 static char resstr_sp[] = " ";
546
547 int
ra_opt_handler(struct ifinfo * ifi)548 ra_opt_handler(struct ifinfo *ifi)
549 {
550 struct ra_opt *rao;
551 struct rainfo *rai;
552 struct script_msg *smp1, *smp2, *smp3;
553 struct timespec now;
554 struct script_msg_head_t sm_rdnss_head =
555 TAILQ_HEAD_INITIALIZER(sm_rdnss_head);
556 struct script_msg_head_t sm_dnssl_head =
557 TAILQ_HEAD_INITIALIZER(sm_dnssl_head);
558
559 int dcount, dlen;
560
561 dcount = 0;
562 dlen = strlen(resstr_sh_prefix) + strlen(resstr_nl);
563 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
564
565 /*
566 * All options from multiple RAs with the same or different
567 * source addresses on a single interface will be gathered and
568 * handled, not overridden. [RFC 4861 6.3.4]
569 */
570 TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) {
571 TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) {
572 switch (rao->rao_type) {
573 case ND_OPT_RDNSS:
574 if (TS_CMP(&now, &rao->rao_expire, >)) {
575 warnmsg(LOG_INFO, __func__,
576 "expired rdnss entry: %s",
577 (char *)rao->rao_msg);
578 break;
579 }
580 ELM_MALLOC(smp1, continue);
581 ELM_MALLOC(smp2, goto free1);
582 ELM_MALLOC(smp3, goto free2);
583 smp1->sm_msg = resstr_ns_prefix;
584 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp1,
585 sm_next);
586 smp2->sm_msg = rao->rao_msg;
587 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp2,
588 sm_next);
589 smp3->sm_msg = resstr_nl;
590 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp3,
591 sm_next);
592 ifi->ifi_rdnss = IFI_DNSOPT_STATE_RECEIVED;
593 break;
594 case ND_OPT_DNSSL:
595 if (TS_CMP(&now, &rao->rao_expire, >)) {
596 warnmsg(LOG_INFO, __func__,
597 "expired dnssl entry: %s",
598 (char *)rao->rao_msg);
599 break;
600 }
601 dcount++;
602 /* Check resolv.conf(5) restrictions. */
603 if (dcount > 6) {
604 warnmsg(LOG_INFO, __func__,
605 "dnssl entry exceeding maximum count (%d>6)"
606 ": %s", dcount, (char *)rao->rao_msg);
607 break;
608 }
609 if (256 < dlen + strlen(rao->rao_msg) +
610 strlen(resstr_sp)) {
611 warnmsg(LOG_INFO, __func__,
612 "dnssl entry exceeding maximum length "
613 "(>256): %s", (char *)rao->rao_msg);
614 break;
615 }
616 ELM_MALLOC(smp1, continue);
617 ELM_MALLOC(smp2, goto free1);
618 if (TAILQ_EMPTY(&sm_dnssl_head)) {
619 ELM_MALLOC(smp3, goto free2);
620 smp3->sm_msg = resstr_sh_prefix;
621 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp3,
622 sm_next);
623 }
624 smp1->sm_msg = rao->rao_msg;
625 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp1,
626 sm_next);
627 smp2->sm_msg = resstr_sp;
628 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp2,
629 sm_next);
630 dlen += strlen(rao->rao_msg) +
631 strlen(resstr_sp);
632 ifi->ifi_dnssl = IFI_DNSOPT_STATE_RECEIVED;
633 break;
634 }
635 continue;
636 free2:
637 free(smp2);
638 free1:
639 free(smp1);
640 }
641 /* Call the script for each information source. */
642 if (uflag)
643 ra_opt_rdnss_dispatch(ifi, rai, &sm_rdnss_head,
644 &sm_dnssl_head);
645 }
646 /* Call the script for each interface. */
647 if (!uflag)
648 ra_opt_rdnss_dispatch(ifi, NULL, &sm_rdnss_head,
649 &sm_dnssl_head);
650 return (0);
651 }
652
653 char *
make_rsid(const char * ifname,const char * origin,struct rainfo * rai)654 make_rsid(const char *ifname, const char *origin, struct rainfo *rai)
655 {
656 char hbuf[NI_MAXHOST];
657
658 if (rai == NULL)
659 sprintf(rsid, "%s:%s", ifname, origin);
660 else {
661 if (!IN6_IS_ADDR_LINKLOCAL(&rai->rai_saddr.sin6_addr))
662 return (NULL);
663 if (getnameinfo((struct sockaddr *)&rai->rai_saddr,
664 rai->rai_saddr.sin6_len, hbuf, sizeof(hbuf), NULL, 0,
665 NI_NUMERICHOST) != 0)
666 return (NULL);
667 sprintf(rsid, "%s:%s:[%s]", ifname, origin, hbuf);
668 }
669 warnmsg(LOG_DEBUG, __func__, "rsid = [%s]", rsid);
670 return (rsid);
671 }
672
673 int
ra_opt_rdnss_dispatch(struct ifinfo * ifi,struct rainfo * rai,struct script_msg_head_t * sm_rdnss_head,struct script_msg_head_t * sm_dnssl_head)674 ra_opt_rdnss_dispatch(struct ifinfo *ifi, struct rainfo *rai,
675 struct script_msg_head_t *sm_rdnss_head,
676 struct script_msg_head_t *sm_dnssl_head)
677 {
678 struct script_msg *smp1;
679 const char *r;
680 int error;
681
682 error = 0;
683 /* Add \n for DNSSL list. */
684 if (!TAILQ_EMPTY(sm_dnssl_head)) {
685 ELM_MALLOC(smp1, goto ra_opt_rdnss_freeit);
686 smp1->sm_msg = resstr_nl;
687 TAILQ_INSERT_TAIL(sm_dnssl_head, smp1, sm_next);
688 }
689 TAILQ_CONCAT(sm_rdnss_head, sm_dnssl_head, sm_next);
690
691 r = make_rsid(ifi->ifname, DNSINFO_ORIGIN_LABEL, uflag ? rai : NULL);
692 if (r == NULL) {
693 warnmsg(LOG_ERR, __func__, "make_rsid() failed. "
694 "Script was not invoked.");
695 error = 1;
696 goto ra_opt_rdnss_freeit;
697 }
698 if (!TAILQ_EMPTY(sm_rdnss_head))
699 CALL_SCRIPT(RESADD, sm_rdnss_head);
700 else if (ifi->ifi_rdnss == IFI_DNSOPT_STATE_RECEIVED ||
701 ifi->ifi_dnssl == IFI_DNSOPT_STATE_RECEIVED) {
702 CALL_SCRIPT(RESDEL, NULL);
703 ifi->ifi_rdnss = IFI_DNSOPT_STATE_NOINFO;
704 ifi->ifi_dnssl = IFI_DNSOPT_STATE_NOINFO;
705 }
706
707 ra_opt_rdnss_freeit:
708 /* Clear script message queue. */
709 if (!TAILQ_EMPTY(sm_rdnss_head)) {
710 while ((smp1 = TAILQ_FIRST(sm_rdnss_head)) != NULL) {
711 TAILQ_REMOVE(sm_rdnss_head, smp1, sm_next);
712 free(smp1);
713 }
714 }
715 if (!TAILQ_EMPTY(sm_dnssl_head)) {
716 while ((smp1 = TAILQ_FIRST(sm_dnssl_head)) != NULL) {
717 TAILQ_REMOVE(sm_dnssl_head, smp1, sm_next);
718 free(smp1);
719 }
720 }
721 return (error);
722 }
723
724 static struct ra_opt *
find_raopt(struct rainfo * rai,int type,void * msg,size_t len)725 find_raopt(struct rainfo *rai, int type, void *msg, size_t len)
726 {
727 struct ra_opt *rao;
728
729 TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) {
730 if (rao->rao_type == type &&
731 rao->rao_len == strlen(msg) &&
732 memcmp(rao->rao_msg, msg, len) == 0)
733 break;
734 }
735
736 return (rao);
737 }
738
739 static void
call_script(const char * const argv[],struct script_msg_head_t * sm_head)740 call_script(const char *const argv[], struct script_msg_head_t *sm_head)
741 {
742 struct script_msg *smp;
743 ssize_t len;
744 int status, wfd;
745
746 if (argv[0] == NULL)
747 return;
748
749 wfd = cap_script_run(capscript, argv);
750 if (wfd == -1) {
751 warnmsg(LOG_ERR, __func__,
752 "failed to run %s: %s", argv[0], strerror(errno));
753 return;
754 }
755
756 if (sm_head != NULL) {
757 TAILQ_FOREACH(smp, sm_head, sm_next) {
758 len = strlen(smp->sm_msg);
759 warnmsg(LOG_DEBUG, __func__, "write to child = %s(%zd)",
760 smp->sm_msg, len);
761 if (write(wfd, smp->sm_msg, len) != len) {
762 warnmsg(LOG_ERR, __func__,
763 "write to child failed: %s",
764 strerror(errno));
765 break;
766 }
767 }
768 }
769
770 (void)close(wfd);
771
772 if (cap_script_wait(capscript, &status) != 0)
773 warnmsg(LOG_ERR, __func__, "wait(): %s", strerror(errno));
774 else
775 warnmsg(LOG_DEBUG, __func__, "script \"%s\" status %d",
776 argv[0], status);
777 }
778
779 /* Decode domain name label encoding in RFC 1035 Section 3.1 */
780 static size_t
dname_labeldec(char * dst,size_t dlen,const char * src)781 dname_labeldec(char *dst, size_t dlen, const char *src)
782 {
783 size_t len;
784 const char *src_origin;
785 const char *src_last;
786 const char *dst_origin;
787
788 src_origin = src;
789 src_last = strchr(src, '\0');
790 dst_origin = dst;
791 memset(dst, '\0', dlen);
792 while ((len = (*src++) & 0x3f) &&
793 src + len <= src_last &&
794 len + (dst == dst_origin ? 0 : 1) < dlen) {
795 if (dst != dst_origin) {
796 *dst++ = '.';
797 dlen--;
798 }
799 warnmsg(LOG_DEBUG, __func__, "labellen = %zd", len);
800 memcpy(dst, src, len);
801 src += len;
802 dst += len;
803 dlen -= len;
804 }
805 *dst = '\0';
806
807 /*
808 * XXX validate that domain name only contains valid characters
809 * for two reasons: 1) correctness, 2) we do not want to pass
810 * possible malicious, unescaped characters like `` to a script
811 * or program that could be exploited that way.
812 */
813
814 return (src - src_origin);
815 }
816