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