usr.sbin/rtsold/rtsol.c

   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  * $FreeBSD$
  35  */
  36
  37 #include <sys/param.h>
  38 #include <sys/capsicum.h>
  39 #include <sys/queue.h>
  40 #include <sys/socket.h>
  41 #include <sys/stat.h>
  42 #include <sys/uio.h>
  43 #include <sys/wait.h>
  44
  45 #include <net/if.h>
  46 #include <net/route.h>
  47 #include <net/if_dl.h>
  48
  49 #define __BSD_VISIBLE   1       /* IN6ADDR_LINKLOCAL_ALLROUTERS_INIT */
  50 #include <netinet/in.h>
  51 #undef  __BSD_VISIBLE
  52 #include <netinet/ip6.h>
  53 #include <netinet6/ip6_var.h>
  54 #include <netinet/icmp6.h>
  55
  56 #include <arpa/inet.h>
  57
  58 #include <capsicum_helpers.h>
  59 #include <netdb.h>
  60 #include <time.h>
  61 #include <fcntl.h>
  62 #include <unistd.h>
  63 #include <stdio.h>
  64 #include <time.h>
  65 #include <err.h>
  66 #include <errno.h>
  67 #include <string.h>
  68 #include <stdlib.h>
  69 #include <syslog.h>
  70 #include "rtsold.h"
  71
  72 static char rsid[IFNAMSIZ + 1 + sizeof(DNSINFO_ORIGIN_LABEL) + 1 + NI_MAXHOST];
  73 struct ifinfo_head_t ifinfo_head = TAILQ_HEAD_INITIALIZER(ifinfo_head);
  74
  75 static void call_script(const char *const *, struct script_msg_head_t *);
  76 static size_t dname_labeldec(char *, size_t, const char *);
  77 static struct ra_opt *find_raopt(struct rainfo *, int, void *, size_t);
  78 static int ra_opt_rdnss_dispatch(struct ifinfo *, struct rainfo *,
  79     struct script_msg_head_t *, struct script_msg_head_t *);
  80 static char *make_rsid(const char *, const char *, struct rainfo *);
  81
  82 #define _ARGS_OTHER     otherconf_script, ifi->ifname
  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
 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
 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 "O bit."
 295          * If the value of OtherConfigFlag changes from FALSE to TRUE, the
 296          * host should invoke the stateful autoconfiguration protocol,
 297          * requesting information.
 298          * [RFC 2462 Section 5.5.3]
 299          */
 300         if (((nd_ra->nd_ra_flags_reserved) & ND_RA_FLAG_OTHER) &&
 301             !ifi->otherconfig) {
 302                 warnmsg(LOG_DEBUG, __func__,
 303                     "OtherConfigFlag on %s is turned on", ifi->ifname);
 304                 ifi->otherconfig = 1;
 305                 CALL_SCRIPT(OTHER, NULL);
 306         }
 307         clock_gettime(CLOCK_MONOTONIC_FAST, &now);
 308         newent_rai = 0;
 309         rai = find_rainfo(ifi, &from);
 310         if (rai == NULL) {
 311                 ELM_MALLOC(rai, exit(1));
 312                 rai->rai_ifinfo = ifi;
 313                 TAILQ_INIT(&rai->rai_ra_opt);
 314                 rai->rai_saddr.sin6_family = AF_INET6;
 315                 rai->rai_saddr.sin6_len = sizeof(rai->rai_saddr);
 316                 memcpy(&rai->rai_saddr.sin6_addr, &from.sin6_addr,
 317                     sizeof(rai->rai_saddr.sin6_addr));
 318                 newent_rai = 1;
 319         }
 320
 321 #define RA_OPT_NEXT_HDR(x)      (struct nd_opt_hdr *)((char *)x + \
 322                                 (((struct nd_opt_hdr *)x)->nd_opt_len * 8))
 323         /* Process RA options. */
 324         warnmsg(LOG_DEBUG, __func__, "Processing RA");
 325         raoptp = (char *)icp + sizeof(struct nd_router_advert);
 326         while (raoptp < (char *)icp + msglen) {
 327                 ndo = (struct nd_opt_hdr *)raoptp;
 328                 warnmsg(LOG_DEBUG, __func__, "ndo = %p", raoptp);
 329                 warnmsg(LOG_DEBUG, __func__, "ndo->nd_opt_type = %d",
 330                     ndo->nd_opt_type);
 331                 warnmsg(LOG_DEBUG, __func__, "ndo->nd_opt_len = %d",
 332                     ndo->nd_opt_len);
 333
 334                 switch (ndo->nd_opt_type) {
 335                 case ND_OPT_RDNSS:
 336                         rdnss = (struct nd_opt_rdnss *)raoptp;
 337
 338                         /* Optlen sanity check (Section 5.3.1 in RFC 6106) */
 339                         if (rdnss->nd_opt_rdnss_len < 3) {
 340                                 warnmsg(LOG_INFO, __func__,
 341                                         "too short RDNSS option"
 342                                         "in RA from %s was ignored.",
 343                                         inet_ntop(AF_INET6, &from.sin6_addr,
 344                                             ntopbuf, sizeof(ntopbuf)));
 345                                 break;
 346                         }
 347
 348                         addr = (struct in6_addr *)(void *)(raoptp + sizeof(*rdnss));
 349                         while ((char *)addr < (char *)RA_OPT_NEXT_HDR(raoptp)) {
 350                                 if (inet_ntop(AF_INET6, addr, ntopbuf,
 351                                         sizeof(ntopbuf)) == NULL) {
 352                                         warnmsg(LOG_INFO, __func__,
 353                                             "an invalid address in RDNSS option"
 354                                             " in RA from %s was ignored.",
 355                                             inet_ntop(AF_INET6, &from.sin6_addr,
 356                                                 ntopbuf, sizeof(ntopbuf)));
 357                                         addr++;
 358                                         continue;
 359                                 }
 360                                 if (IN6_IS_ADDR_LINKLOCAL(addr))
 361                                         /* XXX: % has to be escaped here */
 362                                         l = snprintf(nsbuf, sizeof(nsbuf),
 363                                             "%s%c%s", ntopbuf,
 364                                             SCOPE_DELIMITER,
 365                                             ifi->ifname);
 366                                 else
 367                                         l = snprintf(nsbuf, sizeof(nsbuf),
 368                                             "%s", ntopbuf);
 369                                 if (l < 0 || (size_t)l >= sizeof(nsbuf)) {
 370                                         warnmsg(LOG_ERR, __func__,
 371                                             "address copying error in "
 372                                             "RDNSS option: %d.", l);
 373                                         addr++;
 374                                         continue;
 375                                 }
 376                                 warnmsg(LOG_DEBUG, __func__, "nsbuf = %s",
 377                                     nsbuf);
 378
 379                                 newent_rao = 0;
 380                                 rao = find_raopt(rai, ndo->nd_opt_type, nsbuf,
 381                                     strlen(nsbuf));
 382                                 if (rao == NULL) {
 383                                         ELM_MALLOC(rao, break);
 384                                         rao->rao_type = ndo->nd_opt_type;
 385                                         rao->rao_len = strlen(nsbuf);
 386                                         rao->rao_msg = strdup(nsbuf);
 387                                         if (rao->rao_msg == NULL) {
 388                                                 warnmsg(LOG_ERR, __func__,
 389                                                     "strdup failed: %s",
 390                                                     strerror(errno));
 391                                                 free(rao);
 392                                                 addr++;
 393                                                 continue;
 394                                         }
 395                                         newent_rao = 1;
 396                                 }
 397                                 /* Set expiration timer */
 398                                 memset(&rao->rao_expire, 0,
 399                                     sizeof(rao->rao_expire));
 400                                 memset(&lifetime, 0, sizeof(lifetime));
 401                                 lifetime.tv_sec =
 402                                     ntohl(rdnss->nd_opt_rdnss_lifetime);
 403                                 TS_ADD(&now, &lifetime, &rao->rao_expire);
 404
 405                                 if (newent_rao)
 406                                         TAILQ_INSERT_TAIL(&rai->rai_ra_opt,
 407                                             rao, rao_next);
 408                                 addr++;
 409                         }
 410                         break;
 411                 case ND_OPT_DNSSL:
 412                         dnssl = (struct nd_opt_dnssl *)raoptp;
 413
 414                         /* Optlen sanity check (Section 5.3.1 in RFC 6106) */
 415                         if (dnssl->nd_opt_dnssl_len < 2) {
 416                                 warnmsg(LOG_INFO, __func__,
 417                                         "too short DNSSL option"
 418                                         "in RA from %s was ignored.",
 419                                         inet_ntop(AF_INET6, &from.sin6_addr,
 420                                             ntopbuf, sizeof(ntopbuf)));
 421                                 break;
 422                         }
 423
 424                         /*
 425                          * Ensure NUL-termination in DNSSL in case of
 426                          * malformed field.
 427                          */
 428                         p = (char *)RA_OPT_NEXT_HDR(raoptp);
 429                         *(p - 1) = '\0';
 430
 431                         p = raoptp + sizeof(*dnssl);
 432                         while (1 < (len = dname_labeldec(dname, sizeof(dname),
 433                             p))) {
 434                                 /* length == 1 means empty string */
 435                                 warnmsg(LOG_DEBUG, __func__, "dname = %s",
 436                                     dname);
 437
 438                                 newent_rao = 0;
 439                                 rao = find_raopt(rai, ndo->nd_opt_type, dname,
 440                                     strlen(dname));
 441                                 if (rao == NULL) {
 442                                         ELM_MALLOC(rao, break);
 443                                         rao->rao_type = ndo->nd_opt_type;
 444                                         rao->rao_len = strlen(dname);
 445                                         rao->rao_msg = strdup(dname);
 446                                         if (rao->rao_msg == NULL) {
 447                                                 warnmsg(LOG_ERR, __func__,
 448                                                     "strdup failed: %s",
 449                                                     strerror(errno));
 450                                                 free(rao);
 451                                                 addr++;
 452                                                 continue;
 453                                         }
 454                                         newent_rao = 1;
 455                                 }
 456                                 /* Set expiration timer */
 457                                 memset(&rao->rao_expire, 0,
 458                                     sizeof(rao->rao_expire));
 459                                 memset(&lifetime, 0, sizeof(lifetime));
 460                                 lifetime.tv_sec =
 461                                     ntohl(dnssl->nd_opt_dnssl_lifetime);
 462                                 TS_ADD(&now, &lifetime, &rao->rao_expire);
 463
 464                                 if (newent_rao)
 465                                         TAILQ_INSERT_TAIL(&rai->rai_ra_opt,
 466                                             rao, rao_next);
 467                                 p += len;
 468                         }
 469                         break;
 470                 default:
 471                         /* nothing to do for other options */
 472                         break;
 473                 }
 474                 raoptp = (char *)RA_OPT_NEXT_HDR(raoptp);
 475         }
 476         if (newent_rai)
 477                 TAILQ_INSERT_TAIL(&ifi->ifi_rainfo, rai, rai_next);
 478
 479         ra_opt_handler(ifi);
 480         ifi->racnt++;
 481
 482         switch (ifi->state) {
 483         case IFS_IDLE:          /* should be ignored */
 484         case IFS_DELAY:         /* right? */
 485                 break;
 486         case IFS_PROBE:
 487                 ifi->state = IFS_IDLE;
 488                 ifi->probes = 0;
 489                 rtsol_timer_update(ifi);
 490                 break;
 491         }
 492 }
 493
 494 static char resstr_ns_prefix[] = "nameserver ";
 495 static char resstr_sh_prefix[] = "search ";
 496 static char resstr_nl[] = "\n";
 497 static char resstr_sp[] = " ";
 498
 499 int
 500 ra_opt_handler(struct ifinfo *ifi)
 501 {
 502         struct ra_opt *rao;
 503         struct rainfo *rai;
 504         struct script_msg *smp1, *smp2, *smp3;
 505         struct timespec now;
 506         struct script_msg_head_t sm_rdnss_head =
 507             TAILQ_HEAD_INITIALIZER(sm_rdnss_head);
 508         struct script_msg_head_t sm_dnssl_head =
 509             TAILQ_HEAD_INITIALIZER(sm_dnssl_head);
 510
 511         int dcount, dlen;
 512
 513         dcount = 0;
 514         dlen = strlen(resstr_sh_prefix) + strlen(resstr_nl);
 515         clock_gettime(CLOCK_MONOTONIC_FAST, &now);
 516
 517         /*
 518          * All options from multiple RAs with the same or different
 519          * source addresses on a single interface will be gathered and
 520          * handled, not overridden.  [RFC 4861 6.3.4]
 521          */
 522         TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) {
 523                 TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) {
 524                         switch (rao->rao_type) {
 525                         case ND_OPT_RDNSS:
 526                                 if (TS_CMP(&now, &rao->rao_expire, >)) {
 527                                         warnmsg(LOG_INFO, __func__,
 528                                             "expired rdnss entry: %s",
 529                                             (char *)rao->rao_msg);
 530                                         break;
 531                                 }
 532                                 ELM_MALLOC(smp1, continue);
 533                                 ELM_MALLOC(smp2, goto free1);
 534                                 ELM_MALLOC(smp3, goto free2);
 535                                 smp1->sm_msg = resstr_ns_prefix;
 536                                 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp1,
 537                                     sm_next);
 538                                 smp2->sm_msg = rao->rao_msg;
 539                                 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp2,
 540                                     sm_next);
 541                                 smp3->sm_msg = resstr_nl;
 542                                 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp3,
 543                                     sm_next);
 544                                 ifi->ifi_rdnss = IFI_DNSOPT_STATE_RECEIVED;
 545                                 break;
 546                         case ND_OPT_DNSSL:
 547                                 if (TS_CMP(&now, &rao->rao_expire, >)) {
 548                                         warnmsg(LOG_INFO, __func__,
 549                                             "expired dnssl entry: %s",
 550                                             (char *)rao->rao_msg);
 551                                         break;
 552                                 }
 553                                 dcount++;
 554                                 /* Check resolv.conf(5) restrictions. */
 555                                 if (dcount > 6) {
 556                                         warnmsg(LOG_INFO, __func__,
 557                                             "dnssl entry exceeding maximum count (%d>6)"
 558                                             ": %s", dcount, (char *)rao->rao_msg);
 559                                         break;
 560                                 }
 561                                 if (256 < dlen + strlen(rao->rao_msg) +
 562                                     strlen(resstr_sp)) {
 563                                         warnmsg(LOG_INFO, __func__,
 564                                             "dnssl entry exceeding maximum length "
 565                                             "(>256): %s", (char *)rao->rao_msg);
 566                                         break;
 567                                 }
 568                                 ELM_MALLOC(smp1, continue);
 569                                 ELM_MALLOC(smp2, goto free1);
 570                                 if (TAILQ_EMPTY(&sm_dnssl_head)) {
 571                                         ELM_MALLOC(smp3, goto free2);
 572                                         smp3->sm_msg = resstr_sh_prefix;
 573                                         TAILQ_INSERT_TAIL(&sm_dnssl_head, smp3,
 574                                             sm_next);
 575                                 }
 576                                 smp1->sm_msg = rao->rao_msg;
 577                                 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp1,
 578                                     sm_next);
 579                                 smp2->sm_msg = resstr_sp;
 580                                 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp2,
 581                                     sm_next);
 582                                 dlen += strlen(rao->rao_msg) +
 583                                     strlen(resstr_sp);
 584                                 ifi->ifi_dnssl = IFI_DNSOPT_STATE_RECEIVED;
 585                                 break;
 586                         }
 587                         continue;
 588 free2:
 589                         free(smp2);
 590 free1:
 591                         free(smp1);
 592                 }
 593                 /* Call the script for each information source. */
 594                 if (uflag)
 595                         ra_opt_rdnss_dispatch(ifi, rai, &sm_rdnss_head,
 596                             &sm_dnssl_head);
 597         }
 598         /* Call the script for each interface. */
 599         if (!uflag)
 600                 ra_opt_rdnss_dispatch(ifi, NULL, &sm_rdnss_head,
 601                     &sm_dnssl_head);
 602         return (0);
 603 }
 604
 605 char *
 606 make_rsid(const char *ifname, const char *origin, struct rainfo *rai)
 607 {
 608         char hbuf[NI_MAXHOST];
 609
 610         if (rai == NULL)
 611                 sprintf(rsid, "%s:%s", ifname, origin);
 612         else {
 613                 if (!IN6_IS_ADDR_LINKLOCAL(&rai->rai_saddr.sin6_addr))
 614                         return (NULL);
 615                 if (getnameinfo((struct sockaddr *)&rai->rai_saddr,
 616                         rai->rai_saddr.sin6_len, hbuf, sizeof(hbuf), NULL, 0,
 617                         NI_NUMERICHOST) != 0)
 618                         return (NULL);
 619                 sprintf(rsid, "%s:%s:[%s]", ifname, origin, hbuf);
 620         }
 621         warnmsg(LOG_DEBUG, __func__, "rsid = [%s]", rsid);
 622         return (rsid);
 623 }
 624
 625 int
 626 ra_opt_rdnss_dispatch(struct ifinfo *ifi, struct rainfo *rai,
 627     struct script_msg_head_t *sm_rdnss_head,
 628     struct script_msg_head_t *sm_dnssl_head)
 629 {
 630         struct script_msg *smp1;
 631         const char *r;
 632         int error;
 633
 634         error = 0;
 635         /* Add \n for DNSSL list. */
 636         if (!TAILQ_EMPTY(sm_dnssl_head)) {
 637                 ELM_MALLOC(smp1, goto ra_opt_rdnss_freeit);
 638                 smp1->sm_msg = resstr_nl;
 639                 TAILQ_INSERT_TAIL(sm_dnssl_head, smp1, sm_next);
 640         }
 641         TAILQ_CONCAT(sm_rdnss_head, sm_dnssl_head, sm_next);
 642
 643         r = make_rsid(ifi->ifname, DNSINFO_ORIGIN_LABEL, uflag ? rai : NULL);
 644         if (r == NULL) {
 645                 warnmsg(LOG_ERR, __func__, "make_rsid() failed.  "
 646                     "Script was not invoked.");
 647                 error = 1;
 648                 goto ra_opt_rdnss_freeit;
 649         }
 650         if (!TAILQ_EMPTY(sm_rdnss_head))
 651                 CALL_SCRIPT(RESADD, sm_rdnss_head);
 652         else if (ifi->ifi_rdnss == IFI_DNSOPT_STATE_RECEIVED ||
 653             ifi->ifi_dnssl == IFI_DNSOPT_STATE_RECEIVED) {
 654                 CALL_SCRIPT(RESDEL, NULL);
 655                 ifi->ifi_rdnss = IFI_DNSOPT_STATE_NOINFO;
 656                 ifi->ifi_dnssl = IFI_DNSOPT_STATE_NOINFO;
 657         }
 658
 659 ra_opt_rdnss_freeit:
 660         /* Clear script message queue. */
 661         if (!TAILQ_EMPTY(sm_rdnss_head)) {
 662                 while ((smp1 = TAILQ_FIRST(sm_rdnss_head)) != NULL) {
 663                         TAILQ_REMOVE(sm_rdnss_head, smp1, sm_next);
 664                         free(smp1);
 665                 }
 666         }
 667         if (!TAILQ_EMPTY(sm_dnssl_head)) {
 668                 while ((smp1 = TAILQ_FIRST(sm_dnssl_head)) != NULL) {
 669                         TAILQ_REMOVE(sm_dnssl_head, smp1, sm_next);
 670                         free(smp1);
 671                 }
 672         }
 673         return (error);
 674 }
 675
 676 static struct ra_opt *
 677 find_raopt(struct rainfo *rai, int type, void *msg, size_t len)
 678 {
 679         struct ra_opt *rao;
 680
 681         TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) {
 682                 if (rao->rao_type == type &&
 683                     rao->rao_len == strlen(msg) &&
 684                     memcmp(rao->rao_msg, msg, len) == 0)
 685                         break;
 686         }
 687
 688         return (rao);
 689 }
 690
 691 static void
 692 call_script(const char *const argv[], struct script_msg_head_t *sm_head)
 693 {
 694         struct script_msg *smp;
 695         ssize_t len;
 696         int status, wfd;
 697
 698         if (argv[0] == NULL)
 699                 return;
 700
 701         wfd = cap_script_run(capscript, argv);
 702         if (wfd == -1) {
 703                 warnmsg(LOG_ERR, __func__,
 704                     "failed to run %s: %s", argv[0], strerror(errno));
 705                 return;
 706         }
 707
 708         if (sm_head != NULL) {
 709                 TAILQ_FOREACH(smp, sm_head, sm_next) {
 710                         len = strlen(smp->sm_msg);
 711                         warnmsg(LOG_DEBUG, __func__, "write to child = %s(%zd)",
 712                             smp->sm_msg, len);
 713                         if (write(wfd, smp->sm_msg, len) != len) {
 714                                 warnmsg(LOG_ERR, __func__,
 715                                     "write to child failed: %s",
 716                                     strerror(errno));
 717                                 break;
 718                         }
 719                 }
 720         }
 721
 722         (void)close(wfd);
 723
 724         if (cap_script_wait(capscript, &status) != 0)
 725                 warnmsg(LOG_ERR, __func__, "wait(): %s", strerror(errno));
 726         else
 727                 warnmsg(LOG_DEBUG, __func__, "script \"%s\" status %d",
 728                     argv[0], status);
 729 }
 730
 731 /* Decode domain name label encoding in RFC 1035 Section 3.1 */
 732 static size_t
 733 dname_labeldec(char *dst, size_t dlen, const char *src)
 734 {
 735         size_t len;
 736         const char *src_origin;
 737         const char *src_last;
 738         const char *dst_origin;
 739
 740         src_origin = src;
 741         src_last = strchr(src, '\0');
 742         dst_origin = dst;
 743         memset(dst, '\0', dlen);
 744         while (src && (len = (uint8_t)(*src++) & 0x3f) &&
 745             (src + len) <= src_last &&
 746             (dst - dst_origin < (ssize_t)dlen)) {
 747                 if (dst != dst_origin)
 748                         *dst++ = '.';
 749                 warnmsg(LOG_DEBUG, __func__, "labellen = %zd", len);
 750                 memcpy(dst, src, len);
 751                 src += len;
 752                 dst += len;
 753         }
 754         *dst = '\0';
 755
 756         /*
 757          * XXX validate that domain name only contains valid characters
 758          * for two reasons: 1) correctness, 2) we do not want to pass
 759          * possible malicious, unescaped characters like `` to a script
 760          * or program that could be exploited that way.
 761          */
 762
 763         return (src - src_origin);
 764 }