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_MANAGED   managedconf_script, ifi->ifname, rasender
  83 #define _ARGS_OTHER     otherconf_script, ifi->ifname, rasender
  84 #define _ARGS_ALWAYS    alwaysconf_script, ifi->ifname, rasender
  85 #define _ARGS_RESADD    resolvconf_script, "-a", rsid
  86 #define _ARGS_RESDEL    resolvconf_script, "-d", rsid
  87
  88 #define CALL_SCRIPT(name, sm_head) do {                         \
  89         const char *const sarg[] = { _ARGS_##name, NULL };      \
  90         call_script(sarg, sm_head);                             \
  91 } while (0)
  92
  93 #define ELM_MALLOC(p, error_action) do {                        \
  94         p = malloc(sizeof(*p));                                 \
  95         if (p == NULL) {                                        \
  96                 warnmsg(LOG_ERR, __func__, "malloc failed: %s", \
  97                     strerror(errno));                           \
  98                 error_action;                                   \
  99         }                                                       \
 100         memset(p, 0, sizeof(*p));                               \
 101 } while (0)
 102
 103 int
 104 recvsockopen(void)
 105 {
 106         struct icmp6_filter filt;
 107         cap_rights_t rights;
 108         int on, sock;
 109
 110         if ((sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
 111                 warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno));
 112                 goto fail;
 113         }
 114
 115         /* Provide info about the receiving interface. */
 116         on = 1;
 117         if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
 118             sizeof(on)) < 0) {
 119                 warnmsg(LOG_ERR, __func__, "setsockopt(IPV6_RECVPKTINFO): %s",
 120                     strerror(errno));
 121                 goto fail;
 122         }
 123
 124         /* Include the hop limit from the received header. */
 125         on = 1;
 126         if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
 127             sizeof(on)) < 0) {
 128                 warnmsg(LOG_ERR, __func__, "setsockopt(IPV6_RECVHOPLIMIT): %s",
 129                     strerror(errno));
 130                 goto fail;
 131         }
 132
 133         /* Filter out everything except for Router Advertisements. */
 134         ICMP6_FILTER_SETBLOCKALL(&filt);
 135         ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
 136         if (setsockopt(sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
 137             sizeof(filt)) == -1) {
 138                 warnmsg(LOG_ERR, __func__, "setsockopt(ICMP6_FILTER): %s",
 139                     strerror(errno));
 140                 goto fail;
 141         }
 142
 143         cap_rights_init(&rights, CAP_EVENT, CAP_RECV);
 144         if (caph_rights_limit(sock, &rights) < 0) {
 145                 warnmsg(LOG_ERR, __func__, "caph_rights_limit(): %s",
 146                     strerror(errno));
 147                 goto fail;
 148         }
 149
 150         return (sock);
 151
 152 fail:
 153         if (sock >= 0)
 154                 (void)close(sock);
 155         return (-1);
 156 }
 157
 158 void
 159 rtsol_input(int sock)
 160 {
 161         uint8_t cmsg[CMSG_SPACE(sizeof(struct in6_pktinfo)) +
 162             CMSG_SPACE(sizeof(int))];
 163         struct iovec iov;
 164         struct msghdr hdr;
 165         struct sockaddr_in6 from;
 166         char answer[1500], ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 167         int l, ifindex = 0, *hlimp = NULL;
 168         ssize_t msglen;
 169         struct in6_pktinfo *pi = NULL;
 170         struct ifinfo *ifi = NULL;
 171         struct ra_opt *rao = NULL;
 172         struct icmp6_hdr *icp;
 173         struct nd_router_advert *nd_ra;
 174         struct cmsghdr *cm;
 175         struct rainfo *rai;
 176         char *p, *raoptp;
 177         struct in6_addr *addr;
 178         struct nd_opt_hdr *ndo;
 179         struct nd_opt_rdnss *rdnss;
 180         struct nd_opt_dnssl *dnssl;
 181         size_t len;
 182         char nsbuf[INET6_ADDRSTRLEN + 1 + IFNAMSIZ + 1];
 183         char dname[NI_MAXHOST];
 184         struct timespec lifetime, now;
 185         int newent_rai, newent_rao;
 186
 187         memset(&hdr, 0, sizeof(hdr));
 188         hdr.msg_iov = &iov;
 189         hdr.msg_iovlen = 1;
 190         hdr.msg_name = &from;
 191         hdr.msg_namelen = sizeof(from);
 192         hdr.msg_control = cmsg;
 193         hdr.msg_controllen = sizeof(cmsg);
 194
 195         iov.iov_base = (caddr_t)answer;
 196         iov.iov_len = sizeof(answer);
 197
 198         if ((msglen = recvmsg(sock, &hdr, 0)) < 0) {
 199                 warnmsg(LOG_ERR, __func__, "recvmsg: %s", strerror(errno));
 200                 return;
 201         }
 202
 203         /* Extract control message info. */
 204         for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&hdr); cm != NULL;
 205             cm = (struct cmsghdr *)CMSG_NXTHDR(&hdr, cm)) {
 206                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 207                     cm->cmsg_type == IPV6_PKTINFO &&
 208                     cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
 209                         pi = (struct in6_pktinfo *)(void *)(CMSG_DATA(cm));
 210                         ifindex = pi->ipi6_ifindex;
 211                 }
 212                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 213                     cm->cmsg_type == IPV6_HOPLIMIT &&
 214                     cm->cmsg_len == CMSG_LEN(sizeof(int)))
 215                         hlimp = (int *)(void *)CMSG_DATA(cm);
 216         }
 217
 218         if (ifindex == 0) {
 219                 warnmsg(LOG_ERR, __func__,
 220                     "failed to get receiving interface");
 221                 return;
 222         }
 223         if (hlimp == NULL) {
 224                 warnmsg(LOG_ERR, __func__,
 225                     "failed to get receiving hop limit");
 226                 return;
 227         }
 228
 229         if ((size_t)msglen < sizeof(struct nd_router_advert)) {
 230                 warnmsg(LOG_INFO, __func__,
 231                     "packet size(%zd) is too short", msglen);
 232                 return;
 233         }
 234
 235         icp = (struct icmp6_hdr *)iov.iov_base;
 236         if (icp->icmp6_type != ND_ROUTER_ADVERT) {
 237                 /*
 238                  * this should not happen because we configured a filter
 239                  * that only passes RAs on the receiving socket.
 240                  */
 241                 warnmsg(LOG_ERR, __func__,
 242                     "invalid icmp type(%d) from %s on %s", icp->icmp6_type,
 243                     inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 244                         sizeof(ntopbuf)),
 245                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 246                 return;
 247         }
 248
 249         if (icp->icmp6_code != 0) {
 250                 warnmsg(LOG_INFO, __func__,
 251                     "invalid icmp code(%d) from %s on %s", icp->icmp6_code,
 252                     inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 253                         sizeof(ntopbuf)),
 254                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 255                 return;
 256         }
 257
 258         if (*hlimp != 255) {
 259                 warnmsg(LOG_INFO, __func__,
 260                     "invalid RA with hop limit(%d) from %s on %s",
 261                     *hlimp,
 262                     inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 263                         sizeof(ntopbuf)),
 264                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 265                 return;
 266         }
 267
 268         if (pi && !IN6_IS_ADDR_LINKLOCAL(&from.sin6_addr)) {
 269                 warnmsg(LOG_INFO, __func__,
 270                     "invalid RA with non link-local source from %s on %s",
 271                     inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 272                         sizeof(ntopbuf)),
 273                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 274                 return;
 275         }
 276
 277         /* xxx: more validation? */
 278
 279         if ((ifi = find_ifinfo(pi->ipi6_ifindex)) == NULL) {
 280                 warnmsg(LOG_DEBUG, __func__,
 281                     "received RA from %s on an unexpected IF(%s)",
 282                     inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 283                         sizeof(ntopbuf)),
 284                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 285                 return;
 286         }
 287
 288         warnmsg(LOG_DEBUG, __func__,
 289             "received RA from %s on %s, state is %d",
 290             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, sizeof(ntopbuf)),
 291             ifi->ifname, ifi->state);
 292
 293         nd_ra = (struct nd_router_advert *)icp;
 294
 295         /*
 296          * Process the "M bit."
 297          * If the value of ManagedConfigFlag changes from FALSE to TRUE, the
 298          * host should invoke the stateful autoconfiguration protocol,
 299          * requesting information.
 300          * [RFC 4861 Section 4.2]
 301          * XXX ??? [draft-ietf-v6ops-dhcpv6-slaac-problem-07]
 302          */
 303         if (((nd_ra->nd_ra_flags_reserved) & ND_RA_FLAG_MANAGED) &&
 304             !ifi->managedconfig) {
 305                 const char *rasender = inet_ntop(AF_INET6, &from.sin6_addr,
 306                     ntopbuf, sizeof(ntopbuf));
 307                 warnmsg(LOG_DEBUG, __func__,
 308                     "ManagedConfigFlag on %s is turned on", ifi->ifname);
 309                 ifi->managedconfig = 1;
 310                 CALL_SCRIPT(MANAGED, NULL);
 311         }
 312
 313         /*
 314          * Process the "O bit."
 315          * If the value of OtherConfigFlag changes from FALSE to TRUE, the
 316          * host should invoke the stateful autoconfiguration protocol,
 317          * requesting information unless the "M bit" was set as well in
 318          * which case the "O bit" is redundant.
 319          * [RFC 4861 Section 4.2]
 320          */
 321         if (((nd_ra->nd_ra_flags_reserved) & ND_RA_FLAG_OTHER) &&
 322             !ifi->otherconfig) {
 323                 const char *rasender = inet_ntop(AF_INET6, &from.sin6_addr,
 324                     ntopbuf, sizeof(ntopbuf));
 325                 warnmsg(LOG_DEBUG, __func__,
 326                     "OtherConfigFlag on %s is turned on", ifi->ifname);
 327                 ifi->otherconfig = 1;
 328                 if (!ifi->managedconfig)
 329                         CALL_SCRIPT(OTHER, NULL);
 330         }
 331
 332         /*
 333          * "Always" script.
 334          */
 335         if (!ifi->alwaysconfig) {
 336                 const char *rasender = inet_ntop(AF_INET6, &from.sin6_addr,
 337                     ntopbuf, sizeof(ntopbuf));
 338                 ifi->alwaysconfig = 1;
 339                 CALL_SCRIPT(ALWAYS, NULL);
 340         }
 341
 342         clock_gettime(CLOCK_MONOTONIC_FAST, &now);
 343         newent_rai = 0;
 344         rai = find_rainfo(ifi, &from);
 345         if (rai == NULL) {
 346                 ELM_MALLOC(rai, exit(1));
 347                 rai->rai_ifinfo = ifi;
 348                 TAILQ_INIT(&rai->rai_ra_opt);
 349                 rai->rai_saddr.sin6_family = AF_INET6;
 350                 rai->rai_saddr.sin6_len = sizeof(rai->rai_saddr);
 351                 memcpy(&rai->rai_saddr.sin6_addr, &from.sin6_addr,
 352                     sizeof(rai->rai_saddr.sin6_addr));
 353                 newent_rai = 1;
 354         }
 355
 356 #define RA_OPT_NEXT_HDR(x)      (struct nd_opt_hdr *)((char *)(x) + \
 357                                 (((struct nd_opt_hdr *)(x))->nd_opt_len * 8))
 358         /* Process RA options. */
 359         warnmsg(LOG_DEBUG, __func__, "Processing RA");
 360         raoptp = (char *)icp + sizeof(struct nd_router_advert);
 361         while (raoptp < (char *)icp + msglen) {
 362                 ndo = (struct nd_opt_hdr *)raoptp;
 363                 warnmsg(LOG_DEBUG, __func__, "ndo = %p", raoptp);
 364                 warnmsg(LOG_DEBUG, __func__, "ndo->nd_opt_type = %d",
 365                     ndo->nd_opt_type);
 366                 warnmsg(LOG_DEBUG, __func__, "ndo->nd_opt_len = %d",
 367                     ndo->nd_opt_len);
 368
 369                 if (ndo->nd_opt_len == 0) {
 370                         warnmsg(LOG_INFO, __func__, "invalid option length 0.");
 371                         break;
 372                 }
 373                 if ((char *)RA_OPT_NEXT_HDR(raoptp) > (char *)icp + msglen) {
 374                         warnmsg(LOG_INFO, __func__, "option length overflow.");
 375                         break;
 376                 }
 377
 378                 switch (ndo->nd_opt_type) {
 379                 case ND_OPT_RDNSS:
 380                         rdnss = (struct nd_opt_rdnss *)raoptp;
 381
 382                         /*
 383                          * The option header is 8 bytes long and each address
 384                          * occupies 16 bytes, so the option length must be
 385                          * greater than or equal to 24 bytes and an odd multiple
 386                          * of 8 bytes.  See section 5.1 in RFC 6106.
 387                          */
 388                         if (rdnss->nd_opt_rdnss_len < 3 ||
 389                             rdnss->nd_opt_rdnss_len % 2 == 0) {
 390                                 warnmsg(LOG_INFO, __func__,
 391                                     "too short RDNSS option in RA from %s "
 392                                     "was ignored.",
 393                                 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 394                                     sizeof(ntopbuf)));
 395                                 break;
 396                         }
 397
 398                         addr = (struct in6_addr *)(void *)(raoptp + sizeof(*rdnss));
 399                         while ((char *)addr < (char *)RA_OPT_NEXT_HDR(raoptp)) {
 400                                 if (inet_ntop(AF_INET6, addr, ntopbuf,
 401                                         sizeof(ntopbuf)) == NULL) {
 402                                         warnmsg(LOG_INFO, __func__,
 403                                             "an invalid address in RDNSS option"
 404                                             " in RA from %s was ignored.",
 405                                             inet_ntop(AF_INET6, &from.sin6_addr,
 406                                                 ntopbuf, sizeof(ntopbuf)));
 407                                         addr++;
 408                                         continue;
 409                                 }
 410                                 if (IN6_IS_ADDR_LINKLOCAL(addr))
 411                                         /* XXX: % has to be escaped here */
 412                                         l = snprintf(nsbuf, sizeof(nsbuf),
 413                                             "%s%c%s", ntopbuf,
 414                                             SCOPE_DELIMITER,
 415                                             ifi->ifname);
 416                                 else
 417                                         l = snprintf(nsbuf, sizeof(nsbuf),
 418                                             "%s", ntopbuf);
 419                                 if (l < 0 || (size_t)l >= sizeof(nsbuf)) {
 420                                         warnmsg(LOG_ERR, __func__,
 421                                             "address copying error in "
 422                                             "RDNSS option: %d.", l);
 423                                         addr++;
 424                                         continue;
 425                                 }
 426                                 warnmsg(LOG_DEBUG, __func__, "nsbuf = %s",
 427                                     nsbuf);
 428
 429                                 newent_rao = 0;
 430                                 rao = find_raopt(rai, ndo->nd_opt_type, nsbuf,
 431                                     strlen(nsbuf));
 432                                 if (rao == NULL) {
 433                                         ELM_MALLOC(rao, break);
 434                                         rao->rao_type = ndo->nd_opt_type;
 435                                         rao->rao_len = strlen(nsbuf);
 436                                         rao->rao_msg = strdup(nsbuf);
 437                                         if (rao->rao_msg == NULL) {
 438                                                 warnmsg(LOG_ERR, __func__,
 439                                                     "strdup failed: %s",
 440                                                     strerror(errno));
 441                                                 free(rao);
 442                                                 addr++;
 443                                                 continue;
 444                                         }
 445                                         newent_rao = 1;
 446                                 }
 447                                 /* Set expiration timer */
 448                                 memset(&rao->rao_expire, 0,
 449                                     sizeof(rao->rao_expire));
 450                                 memset(&lifetime, 0, sizeof(lifetime));
 451                                 lifetime.tv_sec =
 452                                     ntohl(rdnss->nd_opt_rdnss_lifetime);
 453                                 TS_ADD(&now, &lifetime, &rao->rao_expire);
 454
 455                                 if (newent_rao)
 456                                         TAILQ_INSERT_TAIL(&rai->rai_ra_opt,
 457                                             rao, rao_next);
 458                                 addr++;
 459                         }
 460                         break;
 461                 case ND_OPT_DNSSL:
 462                         dnssl = (struct nd_opt_dnssl *)raoptp;
 463
 464                         /* Optlen sanity check (Section 5.3.1 in RFC 6106) */
 465                         if (dnssl->nd_opt_dnssl_len < 2) {
 466                                 warnmsg(LOG_INFO, __func__,
 467                                         "too short DNSSL option"
 468                                         "in RA from %s was ignored.",
 469                                         inet_ntop(AF_INET6, &from.sin6_addr,
 470                                             ntopbuf, sizeof(ntopbuf)));
 471                                 break;
 472                         }
 473
 474                         /*
 475                          * Ensure NUL-termination in DNSSL in case of
 476                          * malformed field.
 477                          */
 478                         p = (char *)RA_OPT_NEXT_HDR(raoptp);
 479                         *(p - 1) = '\0';
 480
 481                         p = raoptp + sizeof(*dnssl);
 482                         while (1 < (len = dname_labeldec(dname, sizeof(dname),
 483                             p))) {
 484                                 /* length == 1 means empty string */
 485                                 warnmsg(LOG_DEBUG, __func__, "dname = %s",
 486                                     dname);
 487
 488                                 newent_rao = 0;
 489                                 rao = find_raopt(rai, ndo->nd_opt_type, dname,
 490                                     strlen(dname));
 491                                 if (rao == NULL) {
 492                                         ELM_MALLOC(rao, break);
 493                                         rao->rao_type = ndo->nd_opt_type;
 494                                         rao->rao_len = strlen(dname);
 495                                         rao->rao_msg = strdup(dname);
 496                                         if (rao->rao_msg == NULL) {
 497                                                 warnmsg(LOG_ERR, __func__,
 498                                                     "strdup failed: %s",
 499                                                     strerror(errno));
 500                                                 free(rao);
 501                                                 addr++;
 502                                                 continue;
 503                                         }
 504                                         newent_rao = 1;
 505                                 }
 506                                 /* Set expiration timer */
 507                                 memset(&rao->rao_expire, 0,
 508                                     sizeof(rao->rao_expire));
 509                                 memset(&lifetime, 0, sizeof(lifetime));
 510                                 lifetime.tv_sec =
 511                                     ntohl(dnssl->nd_opt_dnssl_lifetime);
 512                                 TS_ADD(&now, &lifetime, &rao->rao_expire);
 513
 514                                 if (newent_rao)
 515                                         TAILQ_INSERT_TAIL(&rai->rai_ra_opt,
 516                                             rao, rao_next);
 517                                 p += len;
 518                         }
 519                         break;
 520                 default:
 521                         /* nothing to do for other options */
 522                         break;
 523                 }
 524                 raoptp = (char *)RA_OPT_NEXT_HDR(raoptp);
 525         }
 526         if (newent_rai)
 527                 TAILQ_INSERT_TAIL(&ifi->ifi_rainfo, rai, rai_next);
 528
 529         ra_opt_handler(ifi);
 530         ifi->racnt++;
 531
 532         switch (ifi->state) {
 533         case IFS_IDLE:          /* should be ignored */
 534         case IFS_DELAY:         /* right? */
 535                 break;
 536         case IFS_PROBE:
 537                 ifi->state = IFS_IDLE;
 538                 ifi->probes = 0;
 539                 rtsol_timer_update(ifi);
 540                 break;
 541         }
 542 }
 543
 544 static char resstr_ns_prefix[] = "nameserver ";
 545 static char resstr_sh_prefix[] = "search ";
 546 static char resstr_nl[] = "\n";
 547 static char resstr_sp[] = " ";
 548
 549 int
 550 ra_opt_handler(struct ifinfo *ifi)
 551 {
 552         struct ra_opt *rao;
 553         struct rainfo *rai;
 554         struct script_msg *smp1, *smp2, *smp3;
 555         struct timespec now;
 556         struct script_msg_head_t sm_rdnss_head =
 557             TAILQ_HEAD_INITIALIZER(sm_rdnss_head);
 558         struct script_msg_head_t sm_dnssl_head =
 559             TAILQ_HEAD_INITIALIZER(sm_dnssl_head);
 560
 561         int dcount, dlen;
 562
 563         dcount = 0;
 564         dlen = strlen(resstr_sh_prefix) + strlen(resstr_nl);
 565         clock_gettime(CLOCK_MONOTONIC_FAST, &now);
 566
 567         /*
 568          * All options from multiple RAs with the same or different
 569          * source addresses on a single interface will be gathered and
 570          * handled, not overridden.  [RFC 4861 6.3.4]
 571          */
 572         TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) {
 573                 TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) {
 574                         switch (rao->rao_type) {
 575                         case ND_OPT_RDNSS:
 576                                 if (TS_CMP(&now, &rao->rao_expire, >)) {
 577                                         warnmsg(LOG_INFO, __func__,
 578                                             "expired rdnss entry: %s",
 579                                             (char *)rao->rao_msg);
 580                                         break;
 581                                 }
 582                                 ELM_MALLOC(smp1, continue);
 583                                 ELM_MALLOC(smp2, goto free1);
 584                                 ELM_MALLOC(smp3, goto free2);
 585                                 smp1->sm_msg = resstr_ns_prefix;
 586                                 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp1,
 587                                     sm_next);
 588                                 smp2->sm_msg = rao->rao_msg;
 589                                 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp2,
 590                                     sm_next);
 591                                 smp3->sm_msg = resstr_nl;
 592                                 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp3,
 593                                     sm_next);
 594                                 ifi->ifi_rdnss = IFI_DNSOPT_STATE_RECEIVED;
 595                                 break;
 596                         case ND_OPT_DNSSL:
 597                                 if (TS_CMP(&now, &rao->rao_expire, >)) {
 598                                         warnmsg(LOG_INFO, __func__,
 599                                             "expired dnssl entry: %s",
 600                                             (char *)rao->rao_msg);
 601                                         break;
 602                                 }
 603                                 dcount++;
 604                                 /* Check resolv.conf(5) restrictions. */
 605                                 if (dcount > 6) {
 606                                         warnmsg(LOG_INFO, __func__,
 607                                             "dnssl entry exceeding maximum count (%d>6)"
 608                                             ": %s", dcount, (char *)rao->rao_msg);
 609                                         break;
 610                                 }
 611                                 if (256 < dlen + strlen(rao->rao_msg) +
 612                                     strlen(resstr_sp)) {
 613                                         warnmsg(LOG_INFO, __func__,
 614                                             "dnssl entry exceeding maximum length "
 615                                             "(>256): %s", (char *)rao->rao_msg);
 616                                         break;
 617                                 }
 618                                 ELM_MALLOC(smp1, continue);
 619                                 ELM_MALLOC(smp2, goto free1);
 620                                 if (TAILQ_EMPTY(&sm_dnssl_head)) {
 621                                         ELM_MALLOC(smp3, goto free2);
 622                                         smp3->sm_msg = resstr_sh_prefix;
 623                                         TAILQ_INSERT_TAIL(&sm_dnssl_head, smp3,
 624                                             sm_next);
 625                                 }
 626                                 smp1->sm_msg = rao->rao_msg;
 627                                 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp1,
 628                                     sm_next);
 629                                 smp2->sm_msg = resstr_sp;
 630                                 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp2,
 631                                     sm_next);
 632                                 dlen += strlen(rao->rao_msg) +
 633                                     strlen(resstr_sp);
 634                                 ifi->ifi_dnssl = IFI_DNSOPT_STATE_RECEIVED;
 635                                 break;
 636                         }
 637                         continue;
 638 free2:
 639                         free(smp2);
 640 free1:
 641                         free(smp1);
 642                 }
 643                 /* Call the script for each information source. */
 644                 if (uflag)
 645                         ra_opt_rdnss_dispatch(ifi, rai, &sm_rdnss_head,
 646                             &sm_dnssl_head);
 647         }
 648         /* Call the script for each interface. */
 649         if (!uflag)
 650                 ra_opt_rdnss_dispatch(ifi, NULL, &sm_rdnss_head,
 651                     &sm_dnssl_head);
 652         return (0);
 653 }
 654
 655 char *
 656 make_rsid(const char *ifname, const char *origin, struct rainfo *rai)
 657 {
 658         char hbuf[NI_MAXHOST];
 659
 660         if (rai == NULL)
 661                 sprintf(rsid, "%s:%s", ifname, origin);
 662         else {
 663                 if (!IN6_IS_ADDR_LINKLOCAL(&rai->rai_saddr.sin6_addr))
 664                         return (NULL);
 665                 if (getnameinfo((struct sockaddr *)&rai->rai_saddr,
 666                         rai->rai_saddr.sin6_len, hbuf, sizeof(hbuf), NULL, 0,
 667                         NI_NUMERICHOST) != 0)
 668                         return (NULL);
 669                 sprintf(rsid, "%s:%s:[%s]", ifname, origin, hbuf);
 670         }
 671         warnmsg(LOG_DEBUG, __func__, "rsid = [%s]", rsid);
 672         return (rsid);
 673 }
 674
 675 int
 676 ra_opt_rdnss_dispatch(struct ifinfo *ifi, struct rainfo *rai,
 677     struct script_msg_head_t *sm_rdnss_head,
 678     struct script_msg_head_t *sm_dnssl_head)
 679 {
 680         struct script_msg *smp1;
 681         const char *r;
 682         int error;
 683
 684         error = 0;
 685         /* Add \n for DNSSL list. */
 686         if (!TAILQ_EMPTY(sm_dnssl_head)) {
 687                 ELM_MALLOC(smp1, goto ra_opt_rdnss_freeit);
 688                 smp1->sm_msg = resstr_nl;
 689                 TAILQ_INSERT_TAIL(sm_dnssl_head, smp1, sm_next);
 690         }
 691         TAILQ_CONCAT(sm_rdnss_head, sm_dnssl_head, sm_next);
 692
 693         r = make_rsid(ifi->ifname, DNSINFO_ORIGIN_LABEL, uflag ? rai : NULL);
 694         if (r == NULL) {
 695                 warnmsg(LOG_ERR, __func__, "make_rsid() failed.  "
 696                     "Script was not invoked.");
 697                 error = 1;
 698                 goto ra_opt_rdnss_freeit;
 699         }
 700         if (!TAILQ_EMPTY(sm_rdnss_head))
 701                 CALL_SCRIPT(RESADD, sm_rdnss_head);
 702         else if (ifi->ifi_rdnss == IFI_DNSOPT_STATE_RECEIVED ||
 703             ifi->ifi_dnssl == IFI_DNSOPT_STATE_RECEIVED) {
 704                 CALL_SCRIPT(RESDEL, NULL);
 705                 ifi->ifi_rdnss = IFI_DNSOPT_STATE_NOINFO;
 706                 ifi->ifi_dnssl = IFI_DNSOPT_STATE_NOINFO;
 707         }
 708
 709 ra_opt_rdnss_freeit:
 710         /* Clear script message queue. */
 711         if (!TAILQ_EMPTY(sm_rdnss_head)) {
 712                 while ((smp1 = TAILQ_FIRST(sm_rdnss_head)) != NULL) {
 713                         TAILQ_REMOVE(sm_rdnss_head, smp1, sm_next);
 714                         free(smp1);
 715                 }
 716         }
 717         if (!TAILQ_EMPTY(sm_dnssl_head)) {
 718                 while ((smp1 = TAILQ_FIRST(sm_dnssl_head)) != NULL) {
 719                         TAILQ_REMOVE(sm_dnssl_head, smp1, sm_next);
 720                         free(smp1);
 721                 }
 722         }
 723         return (error);
 724 }
 725
 726 static struct ra_opt *
 727 find_raopt(struct rainfo *rai, int type, void *msg, size_t len)
 728 {
 729         struct ra_opt *rao;
 730
 731         TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) {
 732                 if (rao->rao_type == type &&
 733                     rao->rao_len == strlen(msg) &&
 734                     memcmp(rao->rao_msg, msg, len) == 0)
 735                         break;
 736         }
 737
 738         return (rao);
 739 }
 740
 741 static void
 742 call_script(const char *const argv[], struct script_msg_head_t *sm_head)
 743 {
 744         struct script_msg *smp;
 745         ssize_t len;
 746         int status, wfd;
 747
 748         if (argv[0] == NULL)
 749                 return;
 750
 751         wfd = cap_script_run(capscript, argv);
 752         if (wfd == -1) {
 753                 warnmsg(LOG_ERR, __func__,
 754                     "failed to run %s: %s", argv[0], strerror(errno));
 755                 return;
 756         }
 757
 758         if (sm_head != NULL) {
 759                 TAILQ_FOREACH(smp, sm_head, sm_next) {
 760                         len = strlen(smp->sm_msg);
 761                         warnmsg(LOG_DEBUG, __func__, "write to child = %s(%zd)",
 762                             smp->sm_msg, len);
 763                         if (write(wfd, smp->sm_msg, len) != len) {
 764                                 warnmsg(LOG_ERR, __func__,
 765                                     "write to child failed: %s",
 766                                     strerror(errno));
 767                                 break;
 768                         }
 769                 }
 770         }
 771
 772         (void)close(wfd);
 773
 774         if (cap_script_wait(capscript, &status) != 0)
 775                 warnmsg(LOG_ERR, __func__, "wait(): %s", strerror(errno));
 776         else
 777                 warnmsg(LOG_DEBUG, __func__, "script \"%s\" status %d",
 778                     argv[0], status);
 779 }
 780
 781 /* Decode domain name label encoding in RFC 1035 Section 3.1 */
 782 static size_t
 783 dname_labeldec(char *dst, size_t dlen, const char *src)
 784 {
 785         size_t len;
 786         const char *src_origin;
 787         const char *src_last;
 788         const char *dst_origin;
 789
 790         src_origin = src;
 791         src_last = strchr(src, '\0');
 792         dst_origin = dst;
 793         memset(dst, '\0', dlen);
 794         while ((len = (*src++) & 0x3f) &&
 795             src + len <= src_last &&
 796             len + (dst == dst_origin ? 0 : 1) < dlen) {
 797                 if (dst != dst_origin) {
 798                         *dst++ = '.';
 799                         dlen--;
 800                 }
 801                 warnmsg(LOG_DEBUG, __func__, "labellen = %zd", len);
 802                 memcpy(dst, src, len);
 803                 src += len;
 804                 dst += len;
 805                 dlen -= len;
 806         }
 807         *dst = '\0';
 808
 809         /*
 810          * XXX validate that domain name only contains valid characters
 811          * for two reasons: 1) correctness, 2) we do not want to pass
 812          * possible malicious, unescaped characters like `` to a script
 813          * or program that could be exploited that way.
 814          */
 815
 816         return (src - src_origin);
 817 }