sbin/routed/main.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 1983, 1988, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  * $FreeBSD$
  32  */
  33
  34 #include "defs.h"
  35 #include "pathnames.h"
  36 #include <signal.h>
  37 #include <fcntl.h>
  38 #include <sys/file.h>
  39
  40 __COPYRIGHT("@(#) Copyright (c) 1983, 1988, 1993 "
  41             "The Regents of the University of California."
  42             "  All rights reserved.");
  43 __RCSID("$FreeBSD$");
  44
  45 pid_t   mypid;
  46
  47 naddr   myaddr;                         /* system address */
  48 static char myname[MAXHOSTNAMELEN+1];
  49
  50 static int verbose;
  51
  52 int     supplier;                       /* supply or broadcast updates */
  53 int     supplier_set;
  54 static int ipforwarding = 1;            /* kernel forwarding on */
  55
  56 static int default_gateway;             /* 1=advertise default */
  57 static int background = 1;
  58 int     ridhosts;                       /* 1=reduce host routes */
  59 int     mhome;                          /* 1=want multi-homed host route */
  60 int     advertise_mhome;                /* 1=must continue advertising it */
  61 int     auth_ok = 1;                    /* 1=ignore auth if we do not care */
  62 int     insecure;                       /* Reply to special queries or not */
  63
  64 struct timeval epoch;                   /* when started */
  65 struct timeval clk;
  66 static struct timeval prev_clk;
  67 static int usec_fudge;
  68 struct timeval now;                     /* current idea of time */
  69 time_t  now_stale;
  70 time_t  now_expire;
  71 time_t  now_garbage;
  72
  73 static struct timeval next_bcast;       /* next general broadcast */
  74 struct timeval no_flash = {             /* inhibit flash update */
  75         EPOCH+SUPPLY_INTERVAL, 0
  76 };
  77
  78 static struct timeval flush_kern_timer;
  79
  80 static fd_set fdbits;
  81 static int sock_max;
  82 int     rip_sock = -1;                  /* RIP socket */
  83 const struct interface *rip_sock_mcast; /* current multicast interface */
  84 int     rt_sock;                        /* routing socket */
  85 int     rt_sock_seqno;
  86
  87
  88 static  int get_rip_sock(naddr, int);
  89 static void timevalsub(struct timeval *, struct timeval *, struct timeval *);
  90 static void sigalrm(int s UNUSED);
  91 static void sigterm(int sig);
  92
  93 int
  94 main(int argc,
  95      char *argv[])
  96 {
  97         int n, mib[4], off;
  98         size_t len;
  99         char *p, *q;
 100         const char *cp;
 101         struct timeval wtime, t2;
 102         time_t dt;
 103         fd_set ibits;
 104         naddr p_net, p_mask;
 105         struct interface *ifp;
 106         struct parm parm;
 107         char *tracename = 0;
 108
 109
 110         /* Some shells are badly broken and send SIGHUP to backgrounded
 111          * processes.
 112          */
 113         signal(SIGHUP, SIG_IGN);
 114
 115         openlog("routed", LOG_PID, LOG_DAEMON);
 116         ftrace = stdout;
 117
 118         gettimeofday(&clk, 0);
 119         prev_clk = clk;
 120         epoch = clk;
 121         epoch.tv_sec -= EPOCH;
 122         now.tv_sec = EPOCH;
 123         now_stale = EPOCH - STALE_TIME;
 124         now_expire = EPOCH - EXPIRE_TIME;
 125         now_garbage = EPOCH - GARBAGE_TIME;
 126         wtime.tv_sec = 0;
 127
 128         (void)gethostname(myname, sizeof(myname)-1);
 129         (void)gethost(myname, &myaddr);
 130
 131         while ((n = getopt(argc, argv, "isqdghmAtvT:F:P:")) != -1) {
 132                 switch (n) {
 133                 case 'i':
 134                         insecure++;
 135                         break;
 136                 case 's':
 137                         supplier = 1;
 138                         supplier_set = 1;
 139                         break;
 140
 141                 case 'q':
 142                         supplier = 0;
 143                         supplier_set = 1;
 144                         break;
 145
 146                 case 'd':
 147                         background = 0;
 148                         break;
 149
 150                 case 'g':
 151                         memset(&parm, 0, sizeof(parm));
 152                         parm.parm_d_metric = 1;
 153                         cp = check_parms(&parm);
 154                         if (cp != 0)
 155                                 msglog("bad -g: %s", cp);
 156                         else
 157                                 default_gateway = 1;
 158                         break;
 159
 160                 case 'h':               /* suppress extra host routes */
 161                         ridhosts = 1;
 162                         break;
 163
 164                 case 'm':               /* advertise host route */
 165                         mhome = 1;      /* on multi-homed hosts */
 166                         break;
 167
 168                 case 'A':
 169                         /* Ignore authentication if we do not care.
 170                          * Crazy as it is, that is what RFC 1723 requires.
 171                          */
 172                         auth_ok = 0;
 173                         break;
 174
 175                 case 't':
 176                         new_tracelevel++;
 177                         break;
 178
 179                 case 'T':
 180                         tracename = optarg;
 181                         break;
 182
 183                 case 'F':               /* minimal routes for SLIP */
 184                         n = FAKE_METRIC;
 185                         p = strchr(optarg,',');
 186                         if (p && *p != '\0') {
 187                                 n = (int)strtoul(p+1, &q, 0);
 188                                 if (*q == '\0'
 189                                     && n <= HOPCNT_INFINITY-1
 190                                     && n >= 1)
 191                                         *p = '\0';
 192                         }
 193                         if (!getnet(optarg, &p_net, &p_mask)) {
 194                                 msglog("bad network; \"-F %s\"",
 195                                        optarg);
 196                                 break;
 197                         }
 198                         memset(&parm, 0, sizeof(parm));
 199                         parm.parm_net = p_net;
 200                         parm.parm_mask = p_mask;
 201                         parm.parm_d_metric = n;
 202                         cp = check_parms(&parm);
 203                         if (cp != 0)
 204                                 msglog("bad -F: %s", cp);
 205                         break;
 206
 207                 case 'P':
 208                         /* handle arbitrary parameters.
 209                          */
 210                         q = strdup(optarg);
 211                         cp = parse_parms(q, 0);
 212                         if (cp != 0)
 213                                 msglog("%s in \"-P %s\"", cp, optarg);
 214                         free(q);
 215                         break;
 216
 217                 case 'v':
 218                         /* display version */
 219                         verbose++;
 220                         msglog("version 2.31");
 221                         break;
 222
 223                 default:
 224                         goto usage;
 225                 }
 226         }
 227         argc -= optind;
 228         argv += optind;
 229
 230         if (tracename == 0 && argc >= 1) {
 231                 tracename = *argv++;
 232                 argc--;
 233         }
 234         if (tracename != 0 && tracename[0] == '\0')
 235                 goto usage;
 236         if (argc != 0) {
 237 usage:
 238                 logbad(0, "usage: routed [-sqdghmAtv] [-T tracefile]"
 239                        " [-F net[,metric]] [-P parms]");
 240         }
 241         if (geteuid() != 0) {
 242                 if (verbose)
 243                         exit(0);
 244                 logbad(0, "requires UID 0");
 245         }
 246
 247         mib[0] = CTL_NET;
 248         mib[1] = PF_INET;
 249         mib[2] = IPPROTO_IP;
 250         mib[3] = IPCTL_FORWARDING;
 251         len = sizeof(ipforwarding);
 252         if (sysctl(mib, 4, &ipforwarding, &len, 0, 0) < 0)
 253                 LOGERR("sysctl(IPCTL_FORWARDING)");
 254
 255         if (!ipforwarding) {
 256                 if (supplier)
 257                         msglog("-s incompatible with ipforwarding=0");
 258                 if (default_gateway) {
 259                         msglog("-g incompatible with ipforwarding=0");
 260                         default_gateway = 0;
 261                 }
 262                 supplier = 0;
 263                 supplier_set = 1;
 264         }
 265         if (default_gateway) {
 266                 if (supplier_set && !supplier) {
 267                         msglog("-g and -q incompatible");
 268                 } else {
 269                         supplier = 1;
 270                         supplier_set = 1;
 271                 }
 272         }
 273
 274
 275         signal(SIGALRM, sigalrm);
 276         if (!background)
 277                 signal(SIGHUP, sigterm);    /* SIGHUP fatal during debugging */
 278         signal(SIGTERM, sigterm);
 279         signal(SIGINT, sigterm);
 280         signal(SIGUSR1, sigtrace_on);
 281         signal(SIGUSR2, sigtrace_off);
 282
 283         /* get into the background */
 284         if (background && daemon(0, 1) < 0)
 285                 BADERR(0,"daemon()");
 286
 287         mypid = getpid();
 288
 289         /* prepare socket connected to the kernel.
 290          */
 291         rt_sock = socket(AF_ROUTE, SOCK_RAW, 0);
 292         if (rt_sock < 0)
 293                 BADERR(1,"rt_sock = socket()");
 294         if (fcntl(rt_sock, F_SETFL, O_NONBLOCK) == -1)
 295                 logbad(1, "fcntl(rt_sock) O_NONBLOCK: %s", strerror(errno));
 296         off = 0;
 297         if (setsockopt(rt_sock, SOL_SOCKET,SO_USELOOPBACK,
 298                        &off,sizeof(off)) < 0)
 299                 LOGERR("setsockopt(SO_USELOOPBACK,0)");
 300
 301         fix_select();
 302
 303
 304         if (tracename != 0) {
 305                 strncpy(inittracename, tracename, sizeof(inittracename)-1);
 306                 set_tracefile(inittracename, "%s", -1);
 307         } else {
 308                 tracelevel_msg("%s", -1);   /* turn on tracing to stdio */
 309         }
 310
 311         bufinit();
 312
 313         /* initialize radix tree */
 314         rtinit();
 315
 316         /* Pick a random part of the second for our output to minimize
 317          * collisions.
 318          *
 319          * Start broadcasting after hearing from other routers, and
 320          * at a random time so a bunch of systems do not get synchronized
 321          * after a power failure.
 322          */
 323         intvl_random(&next_bcast, EPOCH+MIN_WAITTIME, EPOCH+SUPPLY_INTERVAL);
 324         age_timer.tv_usec = next_bcast.tv_usec;
 325         age_timer.tv_sec = EPOCH+MIN_WAITTIME;
 326         rdisc_timer = next_bcast;
 327         ifinit_timer.tv_usec = next_bcast.tv_usec;
 328
 329         /* Collect an initial view of the world by checking the interface
 330          * configuration and the kludge file.
 331          */
 332         gwkludge();
 333         ifinit();
 334
 335         /* Ask for routes */
 336         rip_query();
 337         rdisc_sol();
 338
 339         /* Now turn off stdio if not tracing */
 340         if (new_tracelevel == 0)
 341                 trace_close(background);
 342
 343         /* Loop forever, listening and broadcasting.
 344          */
 345         for (;;) {
 346                 prev_clk = clk;
 347                 gettimeofday(&clk, 0);
 348                 if (prev_clk.tv_sec == clk.tv_sec
 349                     && prev_clk.tv_usec == clk.tv_usec+usec_fudge) {
 350                         /* Much of `routed` depends on time always advancing.
 351                          * On systems that do not guarantee that gettimeofday()
 352                          * produces unique timestamps even if called within
 353                          * a single tick, use trickery like that in classic
 354                          * BSD kernels.
 355                          */
 356                         clk.tv_usec += ++usec_fudge;
 357
 358                 } else {
 359                         usec_fudge = 0;
 360
 361                         timevalsub(&t2, &clk, &prev_clk);
 362                         if (t2.tv_sec < 0
 363                             || t2.tv_sec > wtime.tv_sec + 5) {
 364                                 /* Deal with time changes before other
 365                                  * housekeeping to keep everything straight.
 366                                  */
 367                                 dt = t2.tv_sec;
 368                                 if (dt > 0)
 369                                         dt -= wtime.tv_sec;
 370                                 trace_act("time changed by %d sec", (int)dt);
 371                                 epoch.tv_sec += dt;
 372                         }
 373                 }
 374                 timevalsub(&now, &clk, &epoch);
 375                 now_stale = now.tv_sec - STALE_TIME;
 376                 now_expire = now.tv_sec - EXPIRE_TIME;
 377                 now_garbage = now.tv_sec - GARBAGE_TIME;
 378
 379                 /* deal with signals that should affect tracing */
 380                 set_tracelevel();
 381
 382                 if (stopint != 0) {
 383                         rip_bcast(0);
 384                         rdisc_adv();
 385                         trace_off("exiting with signal %d", stopint);
 386                         exit(stopint | 128);
 387                 }
 388
 389                 /* look for new or dead interfaces */
 390                 timevalsub(&wtime, &ifinit_timer, &now);
 391                 if (wtime.tv_sec <= 0) {
 392                         wtime.tv_sec = 0;
 393                         ifinit();
 394                         rip_query();
 395                         continue;
 396                 }
 397
 398                 /* Check the kernel table occasionally for mysteriously
 399                  * evaporated routes
 400                  */
 401                 timevalsub(&t2, &flush_kern_timer, &now);
 402                 if (t2.tv_sec <= 0) {
 403                         flush_kern();
 404                         flush_kern_timer.tv_sec = (now.tv_sec
 405                                                    + CHECK_QUIET_INTERVAL);
 406                         continue;
 407                 }
 408                 if (timercmp(&t2, &wtime, <))
 409                         wtime = t2;
 410
 411                 /* If it is time, then broadcast our routes.
 412                  */
 413                 if (supplier || advertise_mhome) {
 414                         timevalsub(&t2, &next_bcast, &now);
 415                         if (t2.tv_sec <= 0) {
 416                                 /* Synchronize the aging and broadcast
 417                                  * timers to minimize awakenings
 418                                  */
 419                                 age(0);
 420
 421                                 rip_bcast(0);
 422
 423                                 /* It is desirable to send routing updates
 424                                  * regularly.  So schedule the next update
 425                                  * 30 seconds after the previous one was
 426                                  * scheduled, instead of 30 seconds after
 427                                  * the previous update was finished.
 428                                  * Even if we just started after discovering
 429                                  * a 2nd interface or were otherwise delayed,
 430                                  * pick a 30-second anniversary of the
 431                                  * original broadcast time.
 432                                  */
 433                                 n = 1 + (0-t2.tv_sec)/SUPPLY_INTERVAL;
 434                                 next_bcast.tv_sec += n*SUPPLY_INTERVAL;
 435
 436                                 continue;
 437                         }
 438
 439                         if (timercmp(&t2, &wtime, <))
 440                                 wtime = t2;
 441                 }
 442
 443                 /* If we need a flash update, either do it now or
 444                  * set the delay to end when it is time.
 445                  *
 446                  * If we are within MIN_WAITTIME seconds of a full update,
 447                  * do not bother.
 448                  */
 449                 if (need_flash
 450                     && supplier
 451                     && no_flash.tv_sec+MIN_WAITTIME < next_bcast.tv_sec) {
 452                         /* accurate to the millisecond */
 453                         if (!timercmp(&no_flash, &now, >))
 454                                 rip_bcast(1);
 455                         timevalsub(&t2, &no_flash, &now);
 456                         if (timercmp(&t2, &wtime, <))
 457                                 wtime = t2;
 458                 }
 459
 460                 /* trigger the main aging timer.
 461                  */
 462                 timevalsub(&t2, &age_timer, &now);
 463                 if (t2.tv_sec <= 0) {
 464                         age(0);
 465                         continue;
 466                 }
 467                 if (timercmp(&t2, &wtime, <))
 468                         wtime = t2;
 469
 470                 /* update the kernel routing table
 471                  */
 472                 timevalsub(&t2, &need_kern, &now);
 473                 if (t2.tv_sec <= 0) {
 474                         age(0);
 475                         continue;
 476                 }
 477                 if (timercmp(&t2, &wtime, <))
 478                         wtime = t2;
 479
 480                 /* take care of router discovery,
 481                  * but do it in the correct the millisecond
 482                  */
 483                 if (!timercmp(&rdisc_timer, &now, >)) {
 484                         rdisc_age(0);
 485                         continue;
 486                 }
 487                 timevalsub(&t2, &rdisc_timer, &now);
 488                 if (timercmp(&t2, &wtime, <))
 489                         wtime = t2;
 490
 491
 492                 /* wait for input or a timer to expire.
 493                  */
 494                 trace_flush();
 495                 ibits = fdbits;
 496                 n = select(sock_max, &ibits, 0, 0, &wtime);
 497                 if (n <= 0) {
 498                         if (n < 0 && errno != EINTR && errno != EAGAIN)
 499                                 BADERR(1,"select");
 500                         continue;
 501                 }
 502
 503                 if (FD_ISSET(rt_sock, &ibits)) {
 504                         read_rt();
 505                         n--;
 506                 }
 507                 if (rdisc_sock >= 0 && FD_ISSET(rdisc_sock, &ibits)) {
 508                         read_d();
 509                         n--;
 510                 }
 511                 if (rip_sock >= 0 && FD_ISSET(rip_sock, &ibits)) {
 512                         read_rip(rip_sock, 0);
 513                         n--;
 514                 }
 515
 516                 LIST_FOREACH(ifp, &ifnet, int_list) {
 517                         if (n <= 0)
 518                                 break;
 519                         if (ifp->int_rip_sock >= 0
 520                             && FD_ISSET(ifp->int_rip_sock, &ibits)) {
 521                                 read_rip(ifp->int_rip_sock, ifp);
 522                                 n--;
 523                         }
 524                 }
 525         }
 526 }
 527
 528
 529 /* ARGSUSED */
 530 static void
 531 sigalrm(int s UNUSED)
 532 {
 533         /* Historically, SIGALRM would cause the daemon to check for
 534          * new and broken interfaces.
 535          */
 536         ifinit_timer.tv_sec = now.tv_sec;
 537         trace_act("SIGALRM");
 538 }
 539
 540
 541 /* watch for fatal signals */
 542 static void
 543 sigterm(int sig)
 544 {
 545         stopint = sig;
 546         (void)signal(sig, SIG_DFL);     /* catch it only once */
 547 }
 548
 549
 550 void
 551 fix_select(void)
 552 {
 553         struct interface *ifp;
 554
 555
 556         FD_ZERO(&fdbits);
 557         sock_max = 0;
 558
 559         FD_SET(rt_sock, &fdbits);
 560         if (sock_max <= rt_sock)
 561                 sock_max = rt_sock+1;
 562         if (rip_sock >= 0) {
 563                 FD_SET(rip_sock, &fdbits);
 564                 if (sock_max <= rip_sock)
 565                         sock_max = rip_sock+1;
 566         }
 567         LIST_FOREACH(ifp, &ifnet, int_list) {
 568                 if (ifp->int_rip_sock >= 0) {
 569                         FD_SET(ifp->int_rip_sock, &fdbits);
 570                         if (sock_max <= ifp->int_rip_sock)
 571                                 sock_max = ifp->int_rip_sock+1;
 572                 }
 573         }
 574         if (rdisc_sock >= 0) {
 575                 FD_SET(rdisc_sock, &fdbits);
 576                 if (sock_max <= rdisc_sock)
 577                         sock_max = rdisc_sock+1;
 578         }
 579 }
 580
 581
 582 void
 583 fix_sock(int sock,
 584          const char *name)
 585 {
 586         int on;
 587 #define MIN_SOCKBUF (4*1024)
 588         static int rbuf;
 589
 590         if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)
 591                 logbad(1, "fcntl(%s) O_NONBLOCK: %s",
 592                        name, strerror(errno));
 593         on = 1;
 594         if (setsockopt(sock, SOL_SOCKET,SO_BROADCAST, &on,sizeof(on)) < 0)
 595                 msglog("setsockopt(%s,SO_BROADCAST): %s",
 596                        name, strerror(errno));
 597 #ifdef USE_PASSIFNAME
 598         on = 1;
 599         if (setsockopt(sock, SOL_SOCKET, SO_PASSIFNAME, &on,sizeof(on)) < 0)
 600                 msglog("setsockopt(%s,SO_PASSIFNAME): %s",
 601                        name, strerror(errno));
 602 #endif
 603
 604         if (rbuf >= MIN_SOCKBUF) {
 605                 if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
 606                                &rbuf, sizeof(rbuf)) < 0)
 607                         msglog("setsockopt(%s,SO_RCVBUF=%d): %s",
 608                                name, rbuf, strerror(errno));
 609         } else {
 610                 for (rbuf = 60*1024; ; rbuf -= 4096) {
 611                         if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
 612                                        &rbuf, sizeof(rbuf)) == 0) {
 613                                 trace_act("RCVBUF=%d", rbuf);
 614                                 break;
 615                         }
 616                         if (rbuf < MIN_SOCKBUF) {
 617                                 msglog("setsockopt(%s,SO_RCVBUF = %d): %s",
 618                                        name, rbuf, strerror(errno));
 619                                 break;
 620                         }
 621                 }
 622         }
 623 }
 624
 625
 626 /* get a rip socket
 627  */
 628 static int                              /* <0 or file descriptor */
 629 get_rip_sock(naddr addr,
 630              int serious)               /* 1=failure to bind is serious */
 631 {
 632         struct sockaddr_in rsin;
 633         unsigned char ttl;
 634         int s;
 635
 636
 637         if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
 638                 BADERR(1,"rip_sock = socket()");
 639
 640         memset(&rsin, 0, sizeof(rsin));
 641 #ifdef _HAVE_SIN_LEN
 642         rsin.sin_len = sizeof(rsin);
 643 #endif
 644         rsin.sin_family = AF_INET;
 645         rsin.sin_port = htons(RIP_PORT);
 646         rsin.sin_addr.s_addr = addr;
 647         if (bind(s, (struct sockaddr *)&rsin, sizeof(rsin)) < 0) {
 648                 if (serious)
 649                         BADERR(errno != EADDRINUSE, "bind(rip_sock)");
 650                 close(s);
 651                 return -1;
 652         }
 653         fix_sock(s,"rip_sock");
 654
 655         ttl = 1;
 656         if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
 657                        &ttl, sizeof(ttl)) < 0)
 658                 DBGERR(1,"rip_sock setsockopt(IP_MULTICAST_TTL)");
 659
 660         return s;
 661 }
 662
 663
 664 /* turn off main RIP socket */
 665 void
 666 rip_off(void)
 667 {
 668         struct interface *ifp;
 669         naddr addr;
 670
 671
 672         if (rip_sock >= 0 && !mhome) {
 673                 trace_act("turn off RIP");
 674
 675                 (void)close(rip_sock);
 676                 rip_sock = -1;
 677
 678                 /* get non-broadcast sockets to listen to queries.
 679                  */
 680                 LIST_FOREACH(ifp, &ifnet, int_list) {
 681                         if (ifp->int_state & IS_REMOTE)
 682                                 continue;
 683                         if (ifp->int_rip_sock < 0) {
 684                                 addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
 685                                         ? ifp->int_dstaddr
 686                                         : ifp->int_addr);
 687                                 ifp->int_rip_sock = get_rip_sock(addr, 0);
 688                         }
 689                 }
 690
 691                 fix_select();
 692
 693                 age(0);
 694         }
 695 }
 696
 697
 698 /* turn on RIP multicast input via an interface
 699  */
 700 static void
 701 rip_mcast_on(struct interface *ifp)
 702 {
 703         struct group_req gr;
 704         struct sockaddr_in *sin;
 705
 706         if (!IS_RIP_IN_OFF(ifp->int_state)
 707             && (ifp->int_if_flags & IFF_MULTICAST)
 708             && !(ifp->int_state & IS_ALIAS)) {
 709                 memset(&gr, 0, sizeof(gr));
 710                 gr.gr_interface = ifp->int_index;
 711                 sin = (struct sockaddr_in *)&gr.gr_group;
 712                 sin->sin_family = AF_INET;
 713 #ifdef _HAVE_SIN_LEN
 714                 sin->sin_len = sizeof(struct sockaddr_in);
 715 #endif
 716                 sin->sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
 717                 if (setsockopt(rip_sock, IPPROTO_IP, MCAST_JOIN_GROUP,
 718                                &gr, sizeof(gr)) < 0)
 719                         LOGERR("setsockopt(MCAST_JOIN_GROUP RIP)");
 720         }
 721 }
 722
 723
 724 /* Prepare socket used for RIP.
 725  */
 726 void
 727 rip_on(struct interface *ifp)
 728 {
 729         /* If the main RIP socket is already alive, only start receiving
 730          * multicasts for this interface.
 731          */
 732         if (rip_sock >= 0) {
 733                 if (ifp != NULL)
 734                         rip_mcast_on(ifp);
 735                 return;
 736         }
 737
 738         /* If the main RIP socket is off and it makes sense to turn it on,
 739          * then turn it on for all of the interfaces.
 740          * It makes sense if either router discovery is off, or if
 741          * router discover is on and at most one interface is doing RIP.
 742          */
 743         if (rip_interfaces > 0 && (!rdisc_ok || rip_interfaces > 1)) {
 744                 trace_act("turn on RIP");
 745
 746                 /* Close all of the query sockets so that we can open
 747                  * the main socket.  SO_REUSEPORT is not a solution,
 748                  * since that would let two daemons bind to the broadcast
 749                  * socket.
 750                  */
 751                 LIST_FOREACH(ifp, &ifnet, int_list) {
 752                         if (ifp->int_rip_sock >= 0) {
 753                                 (void)close(ifp->int_rip_sock);
 754                                 ifp->int_rip_sock = -1;
 755                         }
 756                 }
 757
 758                 rip_sock = get_rip_sock(INADDR_ANY, 1);
 759                 rip_sock_mcast = NULL;
 760
 761                 /* Do not advertise anything until we have heard something
 762                  */
 763                 if (next_bcast.tv_sec < now.tv_sec+MIN_WAITTIME)
 764                         next_bcast.tv_sec = now.tv_sec+MIN_WAITTIME;
 765
 766                 LIST_FOREACH(ifp, &ifnet, int_list) {
 767                         ifp->int_query_time = NEVER;
 768                         rip_mcast_on(ifp);
 769                 }
 770                 ifinit_timer.tv_sec = now.tv_sec;
 771
 772         } else if (ifp != NULL
 773                    && !(ifp->int_state & IS_REMOTE)
 774                    && ifp->int_rip_sock < 0) {
 775                 /* RIP is off, so ensure there are sockets on which
 776                  * to listen for queries.
 777                  */
 778                 ifp->int_rip_sock = get_rip_sock(ifp->int_addr, 0);
 779         }
 780
 781         fix_select();
 782 }
 783
 784
 785 /* die if malloc(3) fails
 786  */
 787 void *
 788 rtmalloc(size_t size,
 789          const char *msg)
 790 {
 791         void *p = malloc(size);
 792         if (p == NULL)
 793                 logbad(1,"malloc(%lu) failed in %s", (u_long)size, msg);
 794         return p;
 795 }
 796
 797
 798 /* get a random instant in an interval
 799  */
 800 void
 801 intvl_random(struct timeval *tp,        /* put value here */
 802              u_long lo,                 /* value is after this second */
 803              u_long hi)                 /* and before this */
 804 {
 805         tp->tv_sec = (time_t)(hi == lo
 806                               ? lo
 807                               : (lo + arc4random_uniform(1 + hi - lo)));
 808         tp->tv_usec = arc4random_uniform(1000000);
 809 }
 810
 811
 812 void
 813 timevaladd(struct timeval *t1,
 814            struct timeval *t2)
 815 {
 816
 817         t1->tv_sec += t2->tv_sec;
 818         if ((t1->tv_usec += t2->tv_usec) >= 1000000) {
 819                 t1->tv_sec++;
 820                 t1->tv_usec -= 1000000;
 821         }
 822 }
 823
 824
 825 /* t1 = t2 - t3
 826  */
 827 static void
 828 timevalsub(struct timeval *t1,
 829            struct timeval *t2,
 830            struct timeval *t3)
 831 {
 832         t1->tv_sec = t2->tv_sec - t3->tv_sec;
 833         if ((t1->tv_usec = t2->tv_usec - t3->tv_usec) < 0) {
 834                 t1->tv_sec--;
 835                 t1->tv_usec += 1000000;
 836         }
 837 }
 838
 839
 840 /* put a message into the system log
 841  */
 842 void
 843 msglog(const char *p, ...)
 844 {
 845         va_list args;
 846
 847         trace_flush();
 848
 849         va_start(args, p);
 850         vsyslog(LOG_ERR, p, args);
 851         va_end(args);
 852         if (ftrace != NULL) {
 853                 if (ftrace == stdout)
 854                         (void)fputs("routed: ", ftrace);
 855                 va_start(args, p);
 856                 (void)vfprintf(ftrace, p, args);
 857                 va_end(args);
 858                 (void)fputc('\n', ftrace);
 859         }
 860 }
 861
 862
 863 /* Put a message about a bad system into the system log if
 864  * we have not complained about it recently.
 865  *
 866  * It is desirable to complain about all bad systems, but not too often.
 867  * In the worst case, it is not practical to keep track of all bad systems.
 868  * For example, there can be many systems with the wrong password.
 869  */
 870 void
 871 msglim(struct msg_limit *lim, naddr addr, const char *p, ...)
 872 {
 873         va_list args;
 874         int i;
 875         struct msg_sub *ms1, *ms;
 876         const char *p1;
 877
 878         /* look for the oldest slot in the table
 879          * or the slot for the bad router.
 880          */
 881         ms = ms1 = lim->subs;
 882         for (i = MSG_SUBJECT_N; ; i--, ms1++) {
 883                 if (i == 0) {
 884                         /* Reuse a slot at most once every 10 minutes.
 885                          */
 886                         if (lim->reuse > now.tv_sec) {
 887                                 ms = NULL;
 888                         } else {
 889                                 ms = ms1;
 890                                 lim->reuse = now.tv_sec + 10*60;
 891                         }
 892                         break;
 893                 }
 894                 if (ms->addr == addr) {
 895                         /* Repeat a complaint about a given system at
 896                          * most once an hour.
 897                          */
 898                         if (ms->until > now.tv_sec)
 899                                 ms = NULL;
 900                         break;
 901                 }
 902                 if (ms->until < ms1->until)
 903                         ms = ms1;
 904         }
 905         if (ms != NULL) {
 906                 ms->addr = addr;
 907                 ms->until = now.tv_sec + 60*60; /* 60 minutes */
 908
 909                 trace_flush();
 910                 for (p1 = p; *p1 == ' '; p1++)
 911                         continue;
 912                 va_start(args, p);
 913                 vsyslog(LOG_ERR, p1, args);
 914                 va_end(args);
 915         }
 916
 917         /* always display the message if tracing */
 918         if (ftrace != NULL) {
 919                 va_start(args, p);
 920                 (void)vfprintf(ftrace, p, args);
 921                 va_end(args);
 922                 (void)fputc('\n', ftrace);
 923         }
 924 }
 925
 926
 927 void
 928 logbad(int dump, const char *p, ...)
 929 {
 930         va_list args;
 931
 932         trace_flush();
 933
 934         va_start(args, p);
 935         vsyslog(LOG_ERR, p, args);
 936         va_end(args);
 937         (void)fputs("routed: ", stderr);
 938         va_start(args, p);
 939         (void)vfprintf(stderr, p, args);
 940         va_end(args);
 941         (void)fputs("; giving up\n",stderr);
 942         (void)fflush(stderr);
 943
 944         if (dump)
 945                 abort();
 946         exit(1);
 947 }