usr.sbin/rtsold/rtsold.c

   1 /*      $KAME: rtsold.c,v 1.67 2003/05/17 18:16:15 itojun Exp $ */
   2
   3 /*-
   4  * SPDX-License-Identifier: BSD-3-Clause
   5  *
   6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the project nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * $FreeBSD$
  34  */
  35
  36 #include <sys/param.h>
  37 #include <sys/ioctl.h>
  38 #include <sys/socket.h>
  39
  40 #include <net/if.h>
  41 #include <net/if_dl.h>
  42
  43 #include <netinet/in.h>
  44 #include <netinet/icmp6.h>
  45 #include <netinet/in_var.h>
  46 #include <arpa/inet.h>
  47
  48 #include <netinet6/nd6.h>
  49
  50 #include <signal.h>
  51 #include <unistd.h>
  52 #include <syslog.h>
  53 #include <string.h>
  54 #include <stdlib.h>
  55 #include <stdio.h>
  56 #include <time.h>
  57 #include <errno.h>
  58 #include <err.h>
  59 #include <stdarg.h>
  60 #include <ifaddrs.h>
  61 #include <poll.h>
  62
  63 #include "rtsold.h"
  64
  65 #define RTSOL_DUMPFILE  "/var/run/rtsold.dump";
  66 #define RTSOL_PIDFILE   "/var/run/rtsold.pid";
  67
  68 struct timespec tm_max;
  69 static int log_upto = 999;
  70 static int fflag = 0;
  71
  72 int Fflag = 0;  /* force setting sysctl parameters */
  73 int aflag = 0;
  74 int dflag = 0;
  75 int uflag = 0;
  76
  77 const char *otherconf_script;
  78 const char *resolvconf_script = "/sbin/resolvconf";
  79
  80 /* protocol constants */
  81 #define MAX_RTR_SOLICITATION_DELAY      1 /* second */
  82 #define RTR_SOLICITATION_INTERVAL       4 /* seconds */
  83 #define MAX_RTR_SOLICITATIONS           3 /* times */
  84
  85 /*
  86  * implementation dependent constants in seconds
  87  * XXX: should be configurable
  88  */
  89 #define PROBE_INTERVAL 60
  90
  91 /* static variables and functions */
  92 static int mobile_node = 0;
  93 static const char *pidfilename = RTSOL_PIDFILE;
  94
  95 #ifndef SMALL
  96 static int do_dump;
  97 static const char *dumpfilename = RTSOL_DUMPFILE;
  98 #endif
  99
 100 static char **autoifprobe(void);
 101 static int ifconfig(char *ifname);
 102 static int make_packet(struct ifinfo *);
 103 static struct timespec *rtsol_check_timer(void);
 104
 105 #ifndef SMALL
 106 static void rtsold_set_dump_file(int);
 107 #endif
 108 static void usage(void);
 109
 110 int
 111 main(int argc, char **argv)
 112 {
 113         int s, ch, once = 0;
 114         struct timespec *timeout;
 115         const char *opts;
 116         struct pollfd set[2];
 117         int rtsock;
 118         char *argv0;
 119
 120 #ifndef SMALL
 121         /* rtsold */
 122         opts = "adDfFm1O:p:R:u";
 123 #else
 124         /* rtsol */
 125         opts = "adDFO:R:u";
 126         fflag = 1;
 127         once = 1;
 128 #endif
 129         argv0 = argv[0];
 130
 131         while ((ch = getopt(argc, argv, opts)) != -1) {
 132                 switch (ch) {
 133                 case 'a':
 134                         aflag = 1;
 135                         break;
 136                 case 'd':
 137                         dflag += 1;
 138                         break;
 139                 case 'D':
 140                         dflag += 2;
 141                         break;
 142                 case 'f':
 143                         fflag = 1;
 144                         break;
 145                 case 'F':
 146                         Fflag = 1;
 147                         break;
 148                 case 'm':
 149                         mobile_node = 1;
 150                         break;
 151                 case '1':
 152                         once = 1;
 153                         break;
 154                 case 'O':
 155                         otherconf_script = optarg;
 156                         break;
 157                 case 'p':
 158                         pidfilename = optarg;
 159                         break;
 160                 case 'R':
 161                         resolvconf_script = optarg;
 162                         break;
 163                 case 'u':
 164                         uflag = 1;
 165                         break;
 166                 default:
 167                         usage();
 168                         exit(1);
 169                 }
 170         }
 171         argc -= optind;
 172         argv += optind;
 173
 174         if ((!aflag && argc == 0) || (aflag && argc != 0)) {
 175                 usage();
 176                 exit(1);
 177         }
 178
 179         /* Generate maximum time in timespec. */
 180         tm_max.tv_sec = (-1) & ~((time_t)1 << ((sizeof(tm_max.tv_sec) * 8) - 1));
 181         tm_max.tv_nsec = (-1) & ~((long)1 << ((sizeof(tm_max.tv_nsec) * 8) - 1));
 182
 183         /* set log level */
 184         if (dflag > 1)
 185                 log_upto = LOG_DEBUG;
 186         else if (dflag > 0)
 187                 log_upto = LOG_INFO;
 188         else
 189                 log_upto = LOG_NOTICE;
 190
 191         if (!fflag) {
 192                 char *ident;
 193
 194                 ident = strrchr(argv0, '/');
 195                 if (!ident)
 196                         ident = argv0;
 197                 else
 198                         ident++;
 199                 openlog(ident, LOG_NDELAY|LOG_PID, LOG_DAEMON);
 200                 if (log_upto >= 0)
 201                         setlogmask(LOG_UPTO(log_upto));
 202         }
 203
 204         if (otherconf_script && *otherconf_script != '/') {
 205                 errx(1, "configuration script (%s) must be an absolute path",
 206                     otherconf_script);
 207         }
 208         if (resolvconf_script && *resolvconf_script != '/') {
 209                 errx(1, "configuration script (%s) must be an absolute path",
 210                     resolvconf_script);
 211         }
 212         if (pidfilename && *pidfilename != '/') {
 213                 errx(1, "pid filename (%s) must be an absolute path",
 214                     pidfilename);
 215         }
 216
 217 #ifndef SMALL
 218         /* initialization to dump internal status to a file */
 219         signal(SIGUSR1, rtsold_set_dump_file);
 220 #endif
 221
 222         if (!fflag)
 223                 daemon(0, 0);           /* act as a daemon */
 224
 225         /*
 226          * Open a socket for sending RS and receiving RA.
 227          * This should be done before calling ifinit(), since the function
 228          * uses the socket.
 229          */
 230         if ((s = sockopen()) < 0) {
 231                 warnmsg(LOG_ERR, __func__, "failed to open a socket");
 232                 exit(1);
 233         }
 234         set[0].fd = s;
 235         set[0].events = POLLIN;
 236         set[1].fd = -1;
 237
 238         if ((rtsock = rtsock_open()) < 0) {
 239                 warnmsg(LOG_ERR, __func__, "failed to open a socket");
 240                 exit(1);
 241         }
 242         set[1].fd = rtsock;
 243         set[1].events = POLLIN;
 244
 245         /* configuration per interface */
 246         if (ifinit()) {
 247                 warnmsg(LOG_ERR, __func__,
 248                     "failed to initialize interfaces");
 249                 exit(1);
 250         }
 251         if (aflag)
 252                 argv = autoifprobe();
 253         while (argv && *argv) {
 254                 if (ifconfig(*argv)) {
 255                         warnmsg(LOG_ERR, __func__,
 256                             "failed to initialize %s", *argv);
 257                         exit(1);
 258                 }
 259                 argv++;
 260         }
 261
 262         /* setup for probing default routers */
 263         if (probe_init()) {
 264                 warnmsg(LOG_ERR, __func__,
 265                     "failed to setup for probing routers");
 266                 exit(1);
 267                 /*NOTREACHED*/
 268         }
 269
 270         /* dump the current pid */
 271         if (!once) {
 272                 pid_t pid = getpid();
 273                 FILE *fp;
 274
 275                 if ((fp = fopen(pidfilename, "w")) == NULL)
 276                         warnmsg(LOG_ERR, __func__,
 277                             "failed to open a pid log file(%s): %s",
 278                             pidfilename, strerror(errno));
 279                 else {
 280                         fprintf(fp, "%d\n", pid);
 281                         fclose(fp);
 282                 }
 283         }
 284         while (1) {             /* main loop */
 285                 int e;
 286 #ifndef SMALL
 287                 if (do_dump) {  /* SIGUSR1 */
 288                         do_dump = 0;
 289                         rtsold_dump_file(dumpfilename);
 290                 }
 291 #endif
 292
 293                 timeout = rtsol_check_timer();
 294
 295                 if (once) {
 296                         struct ifinfo *ifi;
 297
 298                         /* if we have no timeout, we are done (or failed) */
 299                         if (timeout == NULL)
 300                                 break;
 301
 302                         /* if all interfaces have got RA packet, we are done */
 303                         TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
 304                                 if (ifi->state != IFS_DOWN && ifi->racnt == 0)
 305                                         break;
 306                         }
 307                         if (ifi == NULL)
 308                                 break;
 309                 }
 310                 e = poll(set, 2, timeout ? (timeout->tv_sec * 1000 + timeout->tv_nsec / 1000 / 1000) : INFTIM);
 311                 if (e < 1) {
 312                         if (e < 0 && errno != EINTR) {
 313                                 warnmsg(LOG_ERR, __func__, "select: %s",
 314                                     strerror(errno));
 315                         }
 316                         continue;
 317                 }
 318
 319                 /* packet reception */
 320                 if (set[1].revents & POLLIN)
 321                         rtsock_input(rtsock);
 322                 if (set[0].revents & POLLIN)
 323                         rtsol_input(s);
 324         }
 325         /* NOTREACHED */
 326
 327         return (0);
 328 }
 329
 330 static int
 331 ifconfig(char *ifname)
 332 {
 333         struct ifinfo *ifi;
 334         struct sockaddr_dl *sdl;
 335         int flags;
 336
 337         if ((sdl = if_nametosdl(ifname)) == NULL) {
 338                 warnmsg(LOG_ERR, __func__,
 339                     "failed to get link layer information for %s", ifname);
 340                 return (-1);
 341         }
 342         if (find_ifinfo(sdl->sdl_index)) {
 343                 warnmsg(LOG_ERR, __func__,
 344                     "interface %s was already configured", ifname);
 345                 free(sdl);
 346                 return (-1);
 347         }
 348
 349         if (Fflag) {
 350                 struct in6_ndireq nd;
 351                 int s;
 352
 353                 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
 354                         warnmsg(LOG_ERR, __func__, "socket() failed.");
 355                         return (-1);
 356                 }
 357                 memset(&nd, 0, sizeof(nd));
 358                 strlcpy(nd.ifname, ifname, sizeof(nd.ifname));
 359                 if (ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd) < 0) {
 360                         warnmsg(LOG_ERR, __func__,
 361                             "cannot get accept_rtadv flag");
 362                         close(s);
 363                         return (-1);
 364                 }
 365                 nd.ndi.flags |= ND6_IFF_ACCEPT_RTADV;
 366                 if (ioctl(s, SIOCSIFINFO_IN6, (caddr_t)&nd) < 0) {
 367                         warnmsg(LOG_ERR, __func__,
 368                             "cannot set accept_rtadv flag");
 369                         close(s);
 370                         return (-1);
 371                 }
 372                 close(s);
 373         }
 374
 375         if ((ifi = malloc(sizeof(*ifi))) == NULL) {
 376                 warnmsg(LOG_ERR, __func__, "memory allocation failed");
 377                 free(sdl);
 378                 return (-1);
 379         }
 380         memset(ifi, 0, sizeof(*ifi));
 381         ifi->sdl = sdl;
 382         ifi->ifi_rdnss = IFI_DNSOPT_STATE_NOINFO;
 383         ifi->ifi_dnssl = IFI_DNSOPT_STATE_NOINFO;
 384         TAILQ_INIT(&ifi->ifi_rainfo);
 385         strlcpy(ifi->ifname, ifname, sizeof(ifi->ifname));
 386
 387         /* construct a router solicitation message */
 388         if (make_packet(ifi))
 389                 goto bad;
 390
 391         /* set link ID of this interface. */
 392 #ifdef HAVE_SCOPELIB
 393         if (inet_zoneid(AF_INET6, 2, ifname, &ifi->linkid))
 394                 goto bad;
 395 #else
 396         /* XXX: assume interface IDs as link IDs */
 397         ifi->linkid = ifi->sdl->sdl_index;
 398 #endif
 399
 400         /*
 401          * check if the interface is available.
 402          * also check if SIOCGIFMEDIA ioctl is OK on the interface.
 403          */
 404         ifi->mediareqok = 1;
 405         ifi->active = interface_status(ifi);
 406         if (!ifi->mediareqok) {
 407                 /*
 408                  * probe routers periodically even if the link status
 409                  * does not change.
 410                  */
 411                 ifi->probeinterval = PROBE_INTERVAL;
 412         }
 413
 414         /* activate interface: interface_up returns 0 on success */
 415         flags = interface_up(ifi->ifname);
 416         if (flags == 0)
 417                 ifi->state = IFS_DELAY;
 418         else if (flags == IFS_TENTATIVE)
 419                 ifi->state = IFS_TENTATIVE;
 420         else
 421                 ifi->state = IFS_DOWN;
 422
 423         rtsol_timer_update(ifi);
 424
 425         TAILQ_INSERT_TAIL(&ifinfo_head, ifi, ifi_next);
 426         return (0);
 427
 428 bad:
 429         free(ifi->sdl);
 430         free(ifi);
 431         return (-1);
 432 }
 433
 434 struct rainfo *
 435 find_rainfo(struct ifinfo *ifi, struct sockaddr_in6 *sin6)
 436 {
 437         struct rainfo *rai;
 438
 439         TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next)
 440                 if (memcmp(&rai->rai_saddr.sin6_addr, &sin6->sin6_addr,
 441                     sizeof(rai->rai_saddr.sin6_addr)) == 0)
 442                         return (rai);
 443
 444         return (NULL);
 445 }
 446
 447 struct ifinfo *
 448 find_ifinfo(int ifindex)
 449 {
 450         struct ifinfo *ifi;
 451
 452         TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
 453                 if (ifi->sdl->sdl_index == ifindex)
 454                         return (ifi);
 455         }
 456         return (NULL);
 457 }
 458
 459 static int
 460 make_packet(struct ifinfo *ifi)
 461 {
 462         size_t packlen = sizeof(struct nd_router_solicit), lladdroptlen = 0;
 463         struct nd_router_solicit *rs;
 464         char *buf;
 465
 466         if ((lladdroptlen = lladdropt_length(ifi->sdl)) == 0) {
 467                 warnmsg(LOG_INFO, __func__,
 468                     "link-layer address option has null length"
 469                     " on %s. Treat as not included.", ifi->ifname);
 470         }
 471         packlen += lladdroptlen;
 472         ifi->rs_datalen = packlen;
 473
 474         /* allocate buffer */
 475         if ((buf = malloc(packlen)) == NULL) {
 476                 warnmsg(LOG_ERR, __func__,
 477                     "memory allocation failed for %s", ifi->ifname);
 478                 return (-1);
 479         }
 480         ifi->rs_data = buf;
 481
 482         /* fill in the message */
 483         rs = (struct nd_router_solicit *)buf;
 484         rs->nd_rs_type = ND_ROUTER_SOLICIT;
 485         rs->nd_rs_code = 0;
 486         rs->nd_rs_cksum = 0;
 487         rs->nd_rs_reserved = 0;
 488         buf += sizeof(*rs);
 489
 490         /* fill in source link-layer address option */
 491         if (lladdroptlen)
 492                 lladdropt_fill(ifi->sdl, (struct nd_opt_hdr *)buf);
 493
 494         return (0);
 495 }
 496
 497 static struct timespec *
 498 rtsol_check_timer(void)
 499 {
 500         static struct timespec returnval;
 501         struct timespec now, rtsol_timer;
 502         struct ifinfo *ifi;
 503         struct rainfo *rai;
 504         struct ra_opt *rao, *raotmp;
 505         int flags;
 506
 507         clock_gettime(CLOCK_MONOTONIC_FAST, &now);
 508
 509         rtsol_timer = tm_max;
 510
 511         TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
 512                 if (TS_CMP(&ifi->expire, &now, <=)) {
 513                         warnmsg(LOG_DEBUG, __func__, "timer expiration on %s, "
 514                             "state = %d", ifi->ifname, ifi->state);
 515
 516                         while((rai = TAILQ_FIRST(&ifi->ifi_rainfo)) != NULL) {
 517                                 /* Remove all RA options. */
 518                                 TAILQ_REMOVE(&ifi->ifi_rainfo, rai, rai_next);
 519                                 while ((rao = TAILQ_FIRST(&rai->rai_ra_opt)) !=
 520                                     NULL) {
 521                                         TAILQ_REMOVE(&rai->rai_ra_opt, rao,
 522                                             rao_next);
 523                                         if (rao->rao_msg != NULL)
 524                                                 free(rao->rao_msg);
 525                                         free(rao);
 526                                 }
 527                                 free(rai);
 528                         }
 529                         switch (ifi->state) {
 530                         case IFS_DOWN:
 531                         case IFS_TENTATIVE:
 532                                 /* interface_up returns 0 on success */
 533                                 flags = interface_up(ifi->ifname);
 534                                 if (flags == 0)
 535                                         ifi->state = IFS_DELAY;
 536                                 else if (flags == IFS_TENTATIVE)
 537                                         ifi->state = IFS_TENTATIVE;
 538                                 else
 539                                         ifi->state = IFS_DOWN;
 540                                 break;
 541                         case IFS_IDLE:
 542                         {
 543                                 int oldstatus = ifi->active;
 544                                 int probe = 0;
 545
 546                                 ifi->active = interface_status(ifi);
 547
 548                                 if (oldstatus != ifi->active) {
 549                                         warnmsg(LOG_DEBUG, __func__,
 550                                             "%s status is changed"
 551                                             " from %d to %d",
 552                                             ifi->ifname,
 553                                             oldstatus, ifi->active);
 554                                         probe = 1;
 555                                         ifi->state = IFS_DELAY;
 556                                 } else if (ifi->probeinterval &&
 557                                     (ifi->probetimer -=
 558                                     ifi->timer.tv_sec) <= 0) {
 559                                         /* probe timer expired */
 560                                         ifi->probetimer =
 561                                             ifi->probeinterval;
 562                                         probe = 1;
 563                                         ifi->state = IFS_PROBE;
 564                                 }
 565
 566                                 /*
 567                                  * If we need a probe, clear the previous
 568                                  * status wrt the "other" configuration.
 569                                  */
 570                                 if (probe)
 571                                         ifi->otherconfig = 0;
 572
 573                                 if (probe && mobile_node)
 574                                         defrouter_probe(ifi);
 575                                 break;
 576                         }
 577                         case IFS_DELAY:
 578                                 ifi->state = IFS_PROBE;
 579                                 sendpacket(ifi);
 580                                 break;
 581                         case IFS_PROBE:
 582                                 if (ifi->probes < MAX_RTR_SOLICITATIONS)
 583                                         sendpacket(ifi);
 584                                 else {
 585                                         warnmsg(LOG_INFO, __func__,
 586                                             "No answer after sending %d RSs",
 587                                             ifi->probes);
 588                                         ifi->probes = 0;
 589                                         ifi->state = IFS_IDLE;
 590                                 }
 591                                 break;
 592                         }
 593                         rtsol_timer_update(ifi);
 594                 } else {
 595                         /* Expiration check for RA options. */
 596                         int expire = 0;
 597
 598                         TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) {
 599                                 TAILQ_FOREACH_SAFE(rao, &rai->rai_ra_opt,
 600                                     rao_next, raotmp) {
 601                                         warnmsg(LOG_DEBUG, __func__,
 602                                             "RA expiration timer: "
 603                                             "type=%d, msg=%s, expire=%s",
 604                                             rao->rao_type, (char *)rao->rao_msg,
 605                                                 sec2str(&rao->rao_expire));
 606                                         if (TS_CMP(&now, &rao->rao_expire,
 607                                             >=)) {
 608                                                 warnmsg(LOG_DEBUG, __func__,
 609                                                     "RA expiration timer: "
 610                                                     "expired.");
 611                                                 TAILQ_REMOVE(&rai->rai_ra_opt,
 612                                                     rao, rao_next);
 613                                                 if (rao->rao_msg != NULL)
 614                                                         free(rao->rao_msg);
 615                                                 free(rao);
 616                                                 expire = 1;
 617                                         }
 618                                 }
 619                         }
 620                         if (expire)
 621                                 ra_opt_handler(ifi);
 622                 }
 623                 if (TS_CMP(&ifi->expire, &rtsol_timer, <))
 624                         rtsol_timer = ifi->expire;
 625         }
 626
 627         if (TS_CMP(&rtsol_timer, &tm_max, ==)) {
 628                 warnmsg(LOG_DEBUG, __func__, "there is no timer");
 629                 return (NULL);
 630         } else if (TS_CMP(&rtsol_timer, &now, <))
 631                 /* this may occur when the interval is too small */
 632                 returnval.tv_sec = returnval.tv_nsec = 0;
 633         else
 634                 TS_SUB(&rtsol_timer, &now, &returnval);
 635
 636         now.tv_sec += returnval.tv_sec;
 637         now.tv_nsec += returnval.tv_nsec;
 638         warnmsg(LOG_DEBUG, __func__, "New timer is %s",
 639             sec2str(&now));
 640
 641         return (&returnval);
 642 }
 643
 644 void
 645 rtsol_timer_update(struct ifinfo *ifi)
 646 {
 647 #define MILLION 1000000
 648 #define DADRETRY 10             /* XXX: adhoc */
 649         long interval;
 650         struct timespec now;
 651
 652         bzero(&ifi->timer, sizeof(ifi->timer));
 653
 654         switch (ifi->state) {
 655         case IFS_DOWN:
 656         case IFS_TENTATIVE:
 657                 if (++ifi->dadcount > DADRETRY) {
 658                         ifi->dadcount = 0;
 659                         ifi->timer.tv_sec = PROBE_INTERVAL;
 660                 } else
 661                         ifi->timer.tv_sec = 1;
 662                 break;
 663         case IFS_IDLE:
 664                 if (mobile_node) {
 665                         /* XXX should be configurable */
 666                         ifi->timer.tv_sec = 3;
 667                 }
 668                 else
 669                         ifi->timer = tm_max;    /* stop timer(valid?) */
 670                 break;
 671         case IFS_DELAY:
 672                 interval = arc4random_uniform(MAX_RTR_SOLICITATION_DELAY * MILLION);
 673                 ifi->timer.tv_sec = interval / MILLION;
 674                 ifi->timer.tv_nsec = (interval % MILLION) * 1000;
 675                 break;
 676         case IFS_PROBE:
 677                 if (ifi->probes < MAX_RTR_SOLICITATIONS)
 678                         ifi->timer.tv_sec = RTR_SOLICITATION_INTERVAL;
 679                 else {
 680                         /*
 681                          * After sending MAX_RTR_SOLICITATIONS solicitations,
 682                          * we're just waiting for possible replies; there
 683                          * will be no more solicitation.  Thus, we change
 684                          * the timer value to MAX_RTR_SOLICITATION_DELAY based
 685                          * on RFC 2461, Section 6.3.7.
 686                          */
 687                         ifi->timer.tv_sec = MAX_RTR_SOLICITATION_DELAY;
 688                 }
 689                 break;
 690         default:
 691                 warnmsg(LOG_ERR, __func__,
 692                     "illegal interface state(%d) on %s",
 693                     ifi->state, ifi->ifname);
 694                 return;
 695         }
 696
 697         /* reset the timer */
 698         if (TS_CMP(&ifi->timer, &tm_max, ==)) {
 699                 ifi->expire = tm_max;
 700                 warnmsg(LOG_DEBUG, __func__,
 701                     "stop timer for %s", ifi->ifname);
 702         } else {
 703                 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
 704                 TS_ADD(&now, &ifi->timer, &ifi->expire);
 705
 706                 now.tv_sec += ifi->timer.tv_sec;
 707                 now.tv_nsec += ifi->timer.tv_nsec;
 708                 warnmsg(LOG_DEBUG, __func__, "set timer for %s to %s",
 709                     ifi->ifname, sec2str(&now));
 710         }
 711
 712 #undef MILLION
 713 }
 714
 715 #ifndef SMALL
 716 static void
 717 rtsold_set_dump_file(int sig __unused)
 718 {
 719         do_dump = 1;
 720 }
 721 #endif
 722
 723 static void
 724 usage(void)
 725 {
 726 #ifndef SMALL
 727         fprintf(stderr, "usage: rtsold [-dDfFm1] [-O script-name] "
 728             "[-p pidfile] [-R script-name] interface ...\n");
 729         fprintf(stderr, "usage: rtsold [-dDfFm1] [-O script-name] "
 730             "[-p pidfile] [-R script-name] -a\n");
 731 #else
 732         fprintf(stderr, "usage: rtsol [-dDF] [-O script-name] "
 733             "[-p pidfile] [-R script-name] interface ...\n");
 734         fprintf(stderr, "usage: rtsol [-dDF] [-O script-name] "
 735             "[-p pidfile] [-R script-name] -a\n");
 736 #endif
 737 }
 738
 739 void
 740 warnmsg(int priority, const char *func, const char *msg, ...)
 741 {
 742         va_list ap;
 743         char buf[BUFSIZ];
 744
 745         va_start(ap, msg);
 746         if (fflag) {
 747                 if (priority <= log_upto) {
 748                         (void)vfprintf(stderr, msg, ap);
 749                         (void)fprintf(stderr, "\n");
 750                 }
 751         } else {
 752                 snprintf(buf, sizeof(buf), "<%s> %s", func, msg);
 753                 msg = buf;
 754                 vsyslog(priority, msg, ap);
 755         }
 756         va_end(ap);
 757 }
 758
 759 /*
 760  * return a list of interfaces which is suitable to sending an RS.
 761  */
 762 static char **
 763 autoifprobe(void)
 764 {
 765         static char **argv = NULL;
 766         static int n = 0;
 767         char **a;
 768         int s = 0, i, found;
 769         struct ifaddrs *ifap, *ifa;
 770         struct in6_ndireq nd;
 771
 772         /* initialize */
 773         while (n--)
 774                 free(argv[n]);
 775         if (argv) {
 776                 free(argv);
 777                 argv = NULL;
 778         }
 779         n = 0;
 780
 781         if (getifaddrs(&ifap) != 0)
 782                 return (NULL);
 783
 784         if (!Fflag && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
 785                 warnmsg(LOG_ERR, __func__, "socket");
 786                 exit(1);
 787         }
 788
 789         /* find an ethernet */
 790         for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
 791                 if ((ifa->ifa_flags & IFF_UP) == 0)
 792                         continue;
 793                 if ((ifa->ifa_flags & IFF_POINTOPOINT) != 0)
 794                         continue;
 795                 if ((ifa->ifa_flags & IFF_LOOPBACK) != 0)
 796                         continue;
 797                 if ((ifa->ifa_flags & IFF_MULTICAST) == 0)
 798                         continue;
 799
 800                 if (ifa->ifa_addr->sa_family != AF_INET6)
 801                         continue;
 802
 803                 found = 0;
 804                 for (i = 0; i < n; i++) {
 805                         if (strcmp(argv[i], ifa->ifa_name) == 0) {
 806                                 found++;
 807                                 break;
 808                         }
 809                 }
 810                 if (found)
 811                         continue;
 812
 813                 /*
 814                  * Skip the interfaces which IPv6 and/or accepting RA
 815                  * is disabled.
 816                  */
 817                 if (!Fflag) {
 818                         memset(&nd, 0, sizeof(nd));
 819                         strlcpy(nd.ifname, ifa->ifa_name, sizeof(nd.ifname));
 820                         if (ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd) < 0) {
 821                                 warnmsg(LOG_ERR, __func__,
 822                                         "ioctl(SIOCGIFINFO_IN6)");
 823                                 exit(1);
 824                         }
 825                         if ((nd.ndi.flags & ND6_IFF_IFDISABLED))
 826                                 continue;
 827                         if (!(nd.ndi.flags & ND6_IFF_ACCEPT_RTADV))
 828                                 continue;
 829                 }
 830
 831                 /* if we find multiple candidates, just warn. */
 832                 if (n != 0 && dflag > 1)
 833                         warnmsg(LOG_WARNING, __func__,
 834                                 "multiple interfaces found");
 835
 836                 a = realloc(argv, (n + 1) * sizeof(char *));
 837                 if (a == NULL) {
 838                         warnmsg(LOG_ERR, __func__, "realloc");
 839                         exit(1);
 840                 }
 841                 argv = a;
 842                 argv[n] = strdup(ifa->ifa_name);
 843                 if (!argv[n]) {
 844                         warnmsg(LOG_ERR, __func__, "malloc");
 845                         exit(1);
 846                 }
 847                 n++;
 848         }
 849
 850         if (n) {
 851                 a = realloc(argv, (n + 1) * sizeof(char *));
 852                 if (a == NULL) {
 853                         warnmsg(LOG_ERR, __func__, "realloc");
 854                         exit(1);
 855                 }
 856                 argv = a;
 857                 argv[n] = NULL;
 858
 859                 if (dflag > 0) {
 860                         for (i = 0; i < n; i++)
 861                                 warnmsg(LOG_WARNING, __func__, "probing %s",
 862                                         argv[i]);
 863                 }
 864         }
 865         if (!Fflag)
 866                 close(s);
 867         freeifaddrs(ifap);
 868         return (argv);
 869 }