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
  83 #define _ARGS_OTHER     otherconf_script, ifi->ifname
  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                 warnmsg(LOG_DEBUG, __func__,
 305                     "ManagedConfigFlag on %s is turned on", ifi->ifname);
 306                 ifi->managedconfig = 1;
 307                 CALL_SCRIPT(MANAGED, NULL);
 308         }
 309
 310         /*
 311          * Process the "O bit."
 312          * If the value of OtherConfigFlag changes from FALSE to TRUE, the
 313          * host should invoke the stateful autoconfiguration protocol,
 314          * requesting information unless the "M bit" was set as well in
 315          * which case the "O bit" is redundant.
 316          * [RFC 4861 Section 4.2]
 317          */
 318         if (((nd_ra->nd_ra_flags_reserved) & ND_RA_FLAG_OTHER) &&
 319             !ifi->otherconfig) {
 320                 warnmsg(LOG_DEBUG, __func__,
 321                     "OtherConfigFlag on %s is turned on", ifi->ifname);
 322                 ifi->otherconfig = 1;
 323                 if (!ifi->managedconfig)
 324                         CALL_SCRIPT(OTHER, NULL);
 325         }
 326         clock_gettime(CLOCK_MONOTONIC_FAST, &now);
 327         newent_rai = 0;
 328         rai = find_rainfo(ifi, &from);
 329         if (rai == NULL) {
 330                 ELM_MALLOC(rai, exit(1));
 331                 rai->rai_ifinfo = ifi;
 332                 TAILQ_INIT(&rai->rai_ra_opt);
 333                 rai->rai_saddr.sin6_family = AF_INET6;
 334                 rai->rai_saddr.sin6_len = sizeof(rai->rai_saddr);
 335                 memcpy(&rai->rai_saddr.sin6_addr, &from.sin6_addr,
 336                     sizeof(rai->rai_saddr.sin6_addr));
 337                 newent_rai = 1;
 338         }
 339
 340 #define RA_OPT_NEXT_HDR(x)      (struct nd_opt_hdr *)((char *)(x) + \
 341                                 (((struct nd_opt_hdr *)(x))->nd_opt_len * 8))
 342         /* Process RA options. */
 343         warnmsg(LOG_DEBUG, __func__, "Processing RA");
 344         raoptp = (char *)icp + sizeof(struct nd_router_advert);
 345         while (raoptp < (char *)icp + msglen) {
 346                 ndo = (struct nd_opt_hdr *)raoptp;
 347                 warnmsg(LOG_DEBUG, __func__, "ndo = %p", raoptp);
 348                 warnmsg(LOG_DEBUG, __func__, "ndo->nd_opt_type = %d",
 349                     ndo->nd_opt_type);
 350                 warnmsg(LOG_DEBUG, __func__, "ndo->nd_opt_len = %d",
 351                     ndo->nd_opt_len);
 352
 353                 if (ndo->nd_opt_len == 0) {
 354                         warnmsg(LOG_INFO, __func__, "invalid option length 0.");
 355                         break;
 356                 }
 357                 if ((char *)RA_OPT_NEXT_HDR(raoptp) > (char *)icp + msglen) {
 358                         warnmsg(LOG_INFO, __func__, "option length overflow.");
 359                         break;
 360                 }
 361
 362                 switch (ndo->nd_opt_type) {
 363                 case ND_OPT_RDNSS:
 364                         rdnss = (struct nd_opt_rdnss *)raoptp;
 365
 366                         /*
 367                          * The option header is 8 bytes long and each address
 368                          * occupies 16 bytes, so the option length must be
 369                          * greater than or equal to 24 bytes and an odd multiple
 370                          * of 8 bytes.  See section 5.1 in RFC 6106.
 371                          */
 372                         if (rdnss->nd_opt_rdnss_len < 3 ||
 373                             rdnss->nd_opt_rdnss_len % 2 == 0) {
 374                                 warnmsg(LOG_INFO, __func__,
 375                                     "too short RDNSS option in RA from %s "
 376                                     "was ignored.",
 377                                 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 378                                     sizeof(ntopbuf)));
 379                                 break;
 380                         }
 381
 382                         addr = (struct in6_addr *)(void *)(raoptp + sizeof(*rdnss));
 383                         while ((char *)addr < (char *)RA_OPT_NEXT_HDR(raoptp)) {
 384                                 if (inet_ntop(AF_INET6, addr, ntopbuf,
 385                                         sizeof(ntopbuf)) == NULL) {
 386                                         warnmsg(LOG_INFO, __func__,
 387                                             "an invalid address in RDNSS option"
 388                                             " in RA from %s was ignored.",
 389                                             inet_ntop(AF_INET6, &from.sin6_addr,
 390                                                 ntopbuf, sizeof(ntopbuf)));
 391                                         addr++;
 392                                         continue;
 393                                 }
 394                                 if (IN6_IS_ADDR_LINKLOCAL(addr))
 395                                         /* XXX: % has to be escaped here */
 396                                         l = snprintf(nsbuf, sizeof(nsbuf),
 397                                             "%s%c%s", ntopbuf,
 398                                             SCOPE_DELIMITER,
 399                                             ifi->ifname);
 400                                 else
 401                                         l = snprintf(nsbuf, sizeof(nsbuf),
 402                                             "%s", ntopbuf);
 403                                 if (l < 0 || (size_t)l >= sizeof(nsbuf)) {
 404                                         warnmsg(LOG_ERR, __func__,
 405                                             "address copying error in "
 406                                             "RDNSS option: %d.", l);
 407                                         addr++;
 408                                         continue;
 409                                 }
 410                                 warnmsg(LOG_DEBUG, __func__, "nsbuf = %s",
 411                                     nsbuf);
 412
 413                                 newent_rao = 0;
 414                                 rao = find_raopt(rai, ndo->nd_opt_type, nsbuf,
 415                                     strlen(nsbuf));
 416                                 if (rao == NULL) {
 417                                         ELM_MALLOC(rao, break);
 418                                         rao->rao_type = ndo->nd_opt_type;
 419                                         rao->rao_len = strlen(nsbuf);
 420                                         rao->rao_msg = strdup(nsbuf);
 421                                         if (rao->rao_msg == NULL) {
 422                                                 warnmsg(LOG_ERR, __func__,
 423                                                     "strdup failed: %s",
 424                                                     strerror(errno));
 425                                                 free(rao);
 426                                                 addr++;
 427                                                 continue;
 428                                         }
 429                                         newent_rao = 1;
 430                                 }
 431                                 /* Set expiration timer */
 432                                 memset(&rao->rao_expire, 0,
 433                                     sizeof(rao->rao_expire));
 434                                 memset(&lifetime, 0, sizeof(lifetime));
 435                                 lifetime.tv_sec =
 436                                     ntohl(rdnss->nd_opt_rdnss_lifetime);
 437                                 TS_ADD(&now, &lifetime, &rao->rao_expire);
 438
 439                                 if (newent_rao)
 440                                         TAILQ_INSERT_TAIL(&rai->rai_ra_opt,
 441                                             rao, rao_next);
 442                                 addr++;
 443                         }
 444                         break;
 445                 case ND_OPT_DNSSL:
 446                         dnssl = (struct nd_opt_dnssl *)raoptp;
 447
 448                         /* Optlen sanity check (Section 5.3.1 in RFC 6106) */
 449                         if (dnssl->nd_opt_dnssl_len < 2) {
 450                                 warnmsg(LOG_INFO, __func__,
 451                                         "too short DNSSL option"
 452                                         "in RA from %s was ignored.",
 453                                         inet_ntop(AF_INET6, &from.sin6_addr,
 454                                             ntopbuf, sizeof(ntopbuf)));
 455                                 break;
 456                         }
 457
 458                         /*
 459                          * Ensure NUL-termination in DNSSL in case of
 460                          * malformed field.
 461                          */
 462                         p = (char *)RA_OPT_NEXT_HDR(raoptp);
 463                         *(p - 1) = '\0';
 464
 465                         p = raoptp + sizeof(*dnssl);
 466                         while (1 < (len = dname_labeldec(dname, sizeof(dname),
 467                             p))) {
 468                                 /* length == 1 means empty string */
 469                                 warnmsg(LOG_DEBUG, __func__, "dname = %s",
 470                                     dname);
 471
 472                                 newent_rao = 0;
 473                                 rao = find_raopt(rai, ndo->nd_opt_type, dname,
 474                                     strlen(dname));
 475                                 if (rao == NULL) {
 476                                         ELM_MALLOC(rao, break);
 477                                         rao->rao_type = ndo->nd_opt_type;
 478                                         rao->rao_len = strlen(dname);
 479                                         rao->rao_msg = strdup(dname);
 480                                         if (rao->rao_msg == NULL) {
 481                                                 warnmsg(LOG_ERR, __func__,
 482                                                     "strdup failed: %s",
 483                                                     strerror(errno));
 484                                                 free(rao);
 485                                                 addr++;
 486                                                 continue;
 487                                         }
 488                                         newent_rao = 1;
 489                                 }
 490                                 /* Set expiration timer */
 491                                 memset(&rao->rao_expire, 0,
 492                                     sizeof(rao->rao_expire));
 493                                 memset(&lifetime, 0, sizeof(lifetime));
 494                                 lifetime.tv_sec =
 495                                     ntohl(dnssl->nd_opt_dnssl_lifetime);
 496                                 TS_ADD(&now, &lifetime, &rao->rao_expire);
 497
 498                                 if (newent_rao)
 499                                         TAILQ_INSERT_TAIL(&rai->rai_ra_opt,
 500                                             rao, rao_next);
 501                                 p += len;
 502                         }
 503                         break;
 504                 default:
 505                         /* nothing to do for other options */
 506                         break;
 507                 }
 508                 raoptp = (char *)RA_OPT_NEXT_HDR(raoptp);
 509         }
 510         if (newent_rai)
 511                 TAILQ_INSERT_TAIL(&ifi->ifi_rainfo, rai, rai_next);
 512
 513         ra_opt_handler(ifi);
 514         ifi->racnt++;
 515
 516         switch (ifi->state) {
 517         case IFS_IDLE:          /* should be ignored */
 518         case IFS_DELAY:         /* right? */
 519                 break;
 520         case IFS_PROBE:
 521                 ifi->state = IFS_IDLE;
 522                 ifi->probes = 0;
 523                 rtsol_timer_update(ifi);
 524                 break;
 525         }
 526 }
 527
 528 static char resstr_ns_prefix[] = "nameserver ";
 529 static char resstr_sh_prefix[] = "search ";
 530 static char resstr_nl[] = "\n";
 531 static char resstr_sp[] = " ";
 532
 533 int
 534 ra_opt_handler(struct ifinfo *ifi)
 535 {
 536         struct ra_opt *rao;
 537         struct rainfo *rai;
 538         struct script_msg *smp1, *smp2, *smp3;
 539         struct timespec now;
 540         struct script_msg_head_t sm_rdnss_head =
 541             TAILQ_HEAD_INITIALIZER(sm_rdnss_head);
 542         struct script_msg_head_t sm_dnssl_head =
 543             TAILQ_HEAD_INITIALIZER(sm_dnssl_head);
 544
 545         int dcount, dlen;
 546
 547         dcount = 0;
 548         dlen = strlen(resstr_sh_prefix) + strlen(resstr_nl);
 549         clock_gettime(CLOCK_MONOTONIC_FAST, &now);
 550
 551         /*
 552          * All options from multiple RAs with the same or different
 553          * source addresses on a single interface will be gathered and
 554          * handled, not overridden.  [RFC 4861 6.3.4]
 555          */
 556         TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) {
 557                 TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) {
 558                         switch (rao->rao_type) {
 559                         case ND_OPT_RDNSS:
 560                                 if (TS_CMP(&now, &rao->rao_expire, >)) {
 561                                         warnmsg(LOG_INFO, __func__,
 562                                             "expired rdnss entry: %s",
 563                                             (char *)rao->rao_msg);
 564                                         break;
 565                                 }
 566                                 ELM_MALLOC(smp1, continue);
 567                                 ELM_MALLOC(smp2, goto free1);
 568                                 ELM_MALLOC(smp3, goto free2);
 569                                 smp1->sm_msg = resstr_ns_prefix;
 570                                 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp1,
 571                                     sm_next);
 572                                 smp2->sm_msg = rao->rao_msg;
 573                                 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp2,
 574                                     sm_next);
 575                                 smp3->sm_msg = resstr_nl;
 576                                 TAILQ_INSERT_TAIL(&sm_rdnss_head, smp3,
 577                                     sm_next);
 578                                 ifi->ifi_rdnss = IFI_DNSOPT_STATE_RECEIVED;
 579                                 break;
 580                         case ND_OPT_DNSSL:
 581                                 if (TS_CMP(&now, &rao->rao_expire, >)) {
 582                                         warnmsg(LOG_INFO, __func__,
 583                                             "expired dnssl entry: %s",
 584                                             (char *)rao->rao_msg);
 585                                         break;
 586                                 }
 587                                 dcount++;
 588                                 /* Check resolv.conf(5) restrictions. */
 589                                 if (dcount > 6) {
 590                                         warnmsg(LOG_INFO, __func__,
 591                                             "dnssl entry exceeding maximum count (%d>6)"
 592                                             ": %s", dcount, (char *)rao->rao_msg);
 593                                         break;
 594                                 }
 595                                 if (256 < dlen + strlen(rao->rao_msg) +
 596                                     strlen(resstr_sp)) {
 597                                         warnmsg(LOG_INFO, __func__,
 598                                             "dnssl entry exceeding maximum length "
 599                                             "(>256): %s", (char *)rao->rao_msg);
 600                                         break;
 601                                 }
 602                                 ELM_MALLOC(smp1, continue);
 603                                 ELM_MALLOC(smp2, goto free1);
 604                                 if (TAILQ_EMPTY(&sm_dnssl_head)) {
 605                                         ELM_MALLOC(smp3, goto free2);
 606                                         smp3->sm_msg = resstr_sh_prefix;
 607                                         TAILQ_INSERT_TAIL(&sm_dnssl_head, smp3,
 608                                             sm_next);
 609                                 }
 610                                 smp1->sm_msg = rao->rao_msg;
 611                                 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp1,
 612                                     sm_next);
 613                                 smp2->sm_msg = resstr_sp;
 614                                 TAILQ_INSERT_TAIL(&sm_dnssl_head, smp2,
 615                                     sm_next);
 616                                 dlen += strlen(rao->rao_msg) +
 617                                     strlen(resstr_sp);
 618                                 ifi->ifi_dnssl = IFI_DNSOPT_STATE_RECEIVED;
 619                                 break;
 620                         }
 621                         continue;
 622 free2:
 623                         free(smp2);
 624 free1:
 625                         free(smp1);
 626                 }
 627                 /* Call the script for each information source. */
 628                 if (uflag)
 629                         ra_opt_rdnss_dispatch(ifi, rai, &sm_rdnss_head,
 630                             &sm_dnssl_head);
 631         }
 632         /* Call the script for each interface. */
 633         if (!uflag)
 634                 ra_opt_rdnss_dispatch(ifi, NULL, &sm_rdnss_head,
 635                     &sm_dnssl_head);
 636         return (0);
 637 }
 638
 639 char *
 640 make_rsid(const char *ifname, const char *origin, struct rainfo *rai)
 641 {
 642         char hbuf[NI_MAXHOST];
 643
 644         if (rai == NULL)
 645                 sprintf(rsid, "%s:%s", ifname, origin);
 646         else {
 647                 if (!IN6_IS_ADDR_LINKLOCAL(&rai->rai_saddr.sin6_addr))
 648                         return (NULL);
 649                 if (getnameinfo((struct sockaddr *)&rai->rai_saddr,
 650                         rai->rai_saddr.sin6_len, hbuf, sizeof(hbuf), NULL, 0,
 651                         NI_NUMERICHOST) != 0)
 652                         return (NULL);
 653                 sprintf(rsid, "%s:%s:[%s]", ifname, origin, hbuf);
 654         }
 655         warnmsg(LOG_DEBUG, __func__, "rsid = [%s]", rsid);
 656         return (rsid);
 657 }
 658
 659 int
 660 ra_opt_rdnss_dispatch(struct ifinfo *ifi, struct rainfo *rai,
 661     struct script_msg_head_t *sm_rdnss_head,
 662     struct script_msg_head_t *sm_dnssl_head)
 663 {
 664         struct script_msg *smp1;
 665         const char *r;
 666         int error;
 667
 668         error = 0;
 669         /* Add \n for DNSSL list. */
 670         if (!TAILQ_EMPTY(sm_dnssl_head)) {
 671                 ELM_MALLOC(smp1, goto ra_opt_rdnss_freeit);
 672                 smp1->sm_msg = resstr_nl;
 673                 TAILQ_INSERT_TAIL(sm_dnssl_head, smp1, sm_next);
 674         }
 675         TAILQ_CONCAT(sm_rdnss_head, sm_dnssl_head, sm_next);
 676
 677         r = make_rsid(ifi->ifname, DNSINFO_ORIGIN_LABEL, uflag ? rai : NULL);
 678         if (r == NULL) {
 679                 warnmsg(LOG_ERR, __func__, "make_rsid() failed.  "
 680                     "Script was not invoked.");
 681                 error = 1;
 682                 goto ra_opt_rdnss_freeit;
 683         }
 684         if (!TAILQ_EMPTY(sm_rdnss_head))
 685                 CALL_SCRIPT(RESADD, sm_rdnss_head);
 686         else if (ifi->ifi_rdnss == IFI_DNSOPT_STATE_RECEIVED ||
 687             ifi->ifi_dnssl == IFI_DNSOPT_STATE_RECEIVED) {
 688                 CALL_SCRIPT(RESDEL, NULL);
 689                 ifi->ifi_rdnss = IFI_DNSOPT_STATE_NOINFO;
 690                 ifi->ifi_dnssl = IFI_DNSOPT_STATE_NOINFO;
 691         }
 692
 693 ra_opt_rdnss_freeit:
 694         /* Clear script message queue. */
 695         if (!TAILQ_EMPTY(sm_rdnss_head)) {
 696                 while ((smp1 = TAILQ_FIRST(sm_rdnss_head)) != NULL) {
 697                         TAILQ_REMOVE(sm_rdnss_head, smp1, sm_next);
 698                         free(smp1);
 699                 }
 700         }
 701         if (!TAILQ_EMPTY(sm_dnssl_head)) {
 702                 while ((smp1 = TAILQ_FIRST(sm_dnssl_head)) != NULL) {
 703                         TAILQ_REMOVE(sm_dnssl_head, smp1, sm_next);
 704                         free(smp1);
 705                 }
 706         }
 707         return (error);
 708 }
 709
 710 static struct ra_opt *
 711 find_raopt(struct rainfo *rai, int type, void *msg, size_t len)
 712 {
 713         struct ra_opt *rao;
 714
 715         TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) {
 716                 if (rao->rao_type == type &&
 717                     rao->rao_len == strlen(msg) &&
 718                     memcmp(rao->rao_msg, msg, len) == 0)
 719                         break;
 720         }
 721
 722         return (rao);
 723 }
 724
 725 static void
 726 call_script(const char *const argv[], struct script_msg_head_t *sm_head)
 727 {
 728         struct script_msg *smp;
 729         ssize_t len;
 730         int status, wfd;
 731
 732         if (argv[0] == NULL)
 733                 return;
 734
 735         wfd = cap_script_run(capscript, argv);
 736         if (wfd == -1) {
 737                 warnmsg(LOG_ERR, __func__,
 738                     "failed to run %s: %s", argv[0], strerror(errno));
 739                 return;
 740         }
 741
 742         if (sm_head != NULL) {
 743                 TAILQ_FOREACH(smp, sm_head, sm_next) {
 744                         len = strlen(smp->sm_msg);
 745                         warnmsg(LOG_DEBUG, __func__, "write to child = %s(%zd)",
 746                             smp->sm_msg, len);
 747                         if (write(wfd, smp->sm_msg, len) != len) {
 748                                 warnmsg(LOG_ERR, __func__,
 749                                     "write to child failed: %s",
 750                                     strerror(errno));
 751                                 break;
 752                         }
 753                 }
 754         }
 755
 756         (void)close(wfd);
 757
 758         if (cap_script_wait(capscript, &status) != 0)
 759                 warnmsg(LOG_ERR, __func__, "wait(): %s", strerror(errno));
 760         else
 761                 warnmsg(LOG_DEBUG, __func__, "script \"%s\" status %d",
 762                     argv[0], status);
 763 }
 764
 765 /* Decode domain name label encoding in RFC 1035 Section 3.1 */
 766 static size_t
 767 dname_labeldec(char *dst, size_t dlen, const char *src)
 768 {
 769         size_t len;
 770         const char *src_origin;
 771         const char *src_last;
 772         const char *dst_origin;
 773
 774         src_origin = src;
 775         src_last = strchr(src, '\0');
 776         dst_origin = dst;
 777         memset(dst, '\0', dlen);
 778         while ((len = (*src++) & 0x3f) &&
 779             src + len <= src_last &&
 780             len + (dst == dst_origin ? 0 : 1) < dlen) {
 781                 if (dst != dst_origin) {
 782                         *dst++ = '.';
 783                         dlen--;
 784                 }
 785                 warnmsg(LOG_DEBUG, __func__, "labellen = %zd", len);
 786                 memcpy(dst, src, len);
 787                 src += len;
 788                 dst += len;
 789                 dlen -= len;
 790         }
 791         *dst = '\0';
 792
 793         /*
 794          * XXX validate that domain name only contains valid characters
 795          * for two reasons: 1) correctness, 2) we do not want to pass
 796          * possible malicious, unescaped characters like `` to a script
 797          * or program that could be exploited that way.
 798          */
 799
 800         return (src - src_origin);
 801 }