usr.sbin/rwhod/rwhod.c

   1 /*
   2  * Copyright (c) 1983, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#) Copyright (c) 1983, 1993 The Regents of the University of California.  All rights reserved.
  30  * @(#)rwhod.c  8.1 (Berkeley) 6/6/93
  31  * $FreeBSD: src/usr.sbin/rwhod/rwhod.c,v 1.13.2.2 2000/12/23 15:28:12 iedowse Exp $
  32  */
  33
  34 #include <sys/param.h>
  35 #include <sys/socket.h>
  36 #include <sys/stat.h>
  37 #include <sys/signal.h>
  38 #include <sys/ioctl.h>
  39 #include <sys/sysctl.h>
  40
  41 #include <net/if.h>
  42 #include <net/if_dl.h>
  43 #include <net/route.h>
  44 #include <netinet/in.h>
  45 #include <arpa/inet.h>
  46 #include <protocols/rwhod.h>
  47
  48 #include <ctype.h>
  49 #include <err.h>
  50 #include <errno.h>
  51 #include <fcntl.h>
  52 #include <libutil.h>
  53 #include <netdb.h>
  54 #include <paths.h>
  55 #include <poll.h>
  56 #include <stdio.h>
  57 #include <stdlib.h>
  58 #include <string.h>
  59 #include <syslog.h>
  60 #include <unistd.h>
  61 #include <utmp.h>
  62 #include <pwd.h>
  63 #include <grp.h>
  64
  65 /*
  66  * This version of Berkeley's rwhod has been modified to use IP multicast
  67  * datagrams, under control of a new command-line option:
  68  *
  69  *      rwhod -m        causes rwhod to use IP multicast (instead of
  70  *                      broadcast or unicast) on all interfaces that have
  71  *                      the IFF_MULTICAST flag set in their "ifnet" structs
  72  *                      (excluding the loopback interface).  The multicast
  73  *                      reports are sent with a time-to-live of 1, to prevent
  74  *                      forwarding beyond the directly-connected subnet(s).
  75  *
  76  *      rwhod -m <ttl>  causes rwhod to send IP multicast datagrams with a
  77  *                      time-to-live of <ttl>, via a SINGLE interface rather
  78  *                      than all interfaces.  <ttl> must be between 0 and
  79  *                      MAX_MULTICAST_SCOPE, defined below.  Note that "-m 1"
  80  *                      is different than "-m", in that "-m 1" specifies
  81  *                      transmission on one interface only.
  82  *
  83  * When "-m" is used without a <ttl> argument, the program accepts multicast
  84  * rwhod reports from all multicast-capable interfaces.  If a <ttl> argument
  85  * is given, it accepts multicast reports from only one interface, the one
  86  * on which reports are sent (which may be controlled via the host's routing
  87  * table).  Regardless of the "-m" option, the program accepts broadcast or
  88  * unicast reports from all interfaces.  Thus, this program will hear the
  89  * reports of old, non-multicasting rwhods, but, if multicasting is used,
  90  * those old rwhods won't hear the reports generated by this program.
  91  *
  92  *                  -- Steve Deering, Stanford University, February 1989
  93  */
  94
  95 #define UNPRIV_USER             "daemon"
  96 #define UNPRIV_GROUP            "daemon"
  97
  98 #define WITH_ERRNO              1       /* Write to syslog with errno (%m) */
  99 #define WITHOUT_ERRNO           0       /* Write to syslog without errno */
 100
 101 #define NO_MULTICAST            0         /* multicast modes */
 102 #define PER_INTERFACE_MULTICAST 1
 103 #define SCOPED_MULTICAST        2
 104
 105 #define MAX_MULTICAST_SCOPE     32        /* "site-wide", by convention */
 106
 107 #define INADDR_WHOD_GROUP (u_long)0xe0000103      /* 224.0.1.3 */
 108                                           /* (belongs in protocols/rwhod.h) */
 109
 110 int                     insecure_mode;
 111 int                     quiet_mode;
 112 int                     iff_flag = IFF_POINTOPOINT;
 113 int                     multicast_mode  = NO_MULTICAST;
 114 int                     multicast_scope;
 115 struct sockaddr_in      multicast_addr;
 116
 117 char    myname[MAXHOSTNAMELEN];
 118
 119 /*
 120  * We communicate with each neighbor in a list constructed at the time we're
 121  * started up.  Neighbors are currently directly connected via a hardware
 122  * interface.
 123  */
 124 struct  neighbor {
 125         struct  neighbor *n_next;
 126         char    *n_name;                /* interface name */
 127         struct  sockaddr *n_addr;               /* who to send to */
 128         int     n_addrlen;              /* size of address */
 129         int     n_flags;                /* should forward?, interface flags */
 130 };
 131
 132 struct  neighbor *neighbors;
 133 struct  whod mywd;
 134 struct  servent *sp;
 135 int     s, utmpf;
 136 volatile sig_atomic_t   onsighup;
 137
 138 #define WHDRSIZE        (sizeof(mywd) - sizeof(mywd.wd_we))
 139
 140 void     run_as(uid_t *, gid_t *);
 141 int      configure(int);
 142 void     getboottime(void);
 143 void     send_host_information(void);
 144 void     hup(int);
 145 void     quit(const char *, int);
 146 void     rt_xaddrs(caddr_t, caddr_t, struct rt_addrinfo *);
 147 int      verify(char *, int);
 148 void     handleread(int);
 149 static void usage(void);
 150 void     timeadd(struct timeval *, time_t, struct timeval *);
 151
 152 #ifdef DEBUG
 153 char    *interval(int, const char *);
 154 ssize_t Sendto(int, const void *, size_t, int,
 155                      const struct sockaddr *, int);
 156 #else
 157 #define Sendto sendto
 158 #endif
 159
 160 int
 161 main(int argc, char *argv[])
 162 {
 163         struct pollfd pfd[1];
 164         char *ep, *cp;
 165         int on = 1;
 166         int send_time = 180;    /* Default time, 180 seconds (3 minutes) */
 167         struct sockaddr_in m_sin;
 168         uid_t unpriv_uid;
 169         gid_t unpriv_gid;
 170         long tmp;
 171         time_t delta = 0;
 172         struct timeval next = { .tv_sec = 0 }, now;
 173
 174         if (getuid())
 175                 errx(1, "not super user");
 176
 177         run_as(&unpriv_uid, &unpriv_gid);
 178
 179         argv++; argc--;
 180         while (argc > 0 && *argv[0] == '-') {
 181                 if (strcmp(*argv, "-m") == 0) {
 182                         if (argc > 1 && *(argv + 1)[0] != '-') {
 183                                 /* Argument has been given */
 184                                 argv++, argc--;
 185                                 multicast_mode = SCOPED_MULTICAST;
 186                                 tmp = strtol(*argv, &ep, 10);
 187                                 if (*ep != '\0' || tmp < INT_MIN || tmp > INT_MAX)
 188                                         errx(1, "invalid ttl: %s", *argv);
 189                                 multicast_scope = (int)tmp;
 190                                 if (multicast_scope > MAX_MULTICAST_SCOPE)
 191                                         errx(1, "ttl must not exceed %u",
 192                                         MAX_MULTICAST_SCOPE);
 193                         }
 194                         else multicast_mode = PER_INTERFACE_MULTICAST;
 195                 } else if (strcmp(*argv, "-g") == 0) {
 196                         if (argc > 1 && *(argv + 1)[0] != '-') {
 197                                 argv++, argc--;
 198                                 send_time = (int)strtol(*argv, &ep, 10);
 199                                 if (send_time <= 0)
 200                                         errx(1, "time must be greater than 0");
 201
 202                                 if (ep[0] != '\0') {
 203                                         if (ep[1] != '\0')
 204                                                 errx(1, "invalid argument: %s", *argv);
 205                                         if (*ep == 'M' || *ep == 'm') {
 206                                                 /* Time in minutes. */
 207                                                 send_time *= 60;
 208                                         } else
 209                                                 errx(1, "invalid argument: %s", *argv);
 210                                 }
 211
 212                                 if (send_time > 180)
 213                                         errx(1, "cannot be greater than 180 seconds (3 minutes)");
 214                         } else
 215                                 errx(1, "missing argument");
 216                 } else if (strcmp(*argv, "-i") == 0)
 217                         insecure_mode = 1;
 218                 else if (strcmp(*argv, "-l") == 0)
 219                         quiet_mode = 1;
 220                 else if (strcmp(*argv, "-p") == 0)
 221                         iff_flag = 0;
 222                 else
 223                         usage();
 224                 argv++, argc--;
 225         }
 226         if (argc > 0)
 227                 usage();
 228 #ifndef DEBUG
 229         struct pidfh *pfh = NULL;
 230         pfh = pidfile_open(NULL, 600, NULL);
 231         daemon(1, 0);
 232         pidfile_write(pfh);
 233 #endif
 234         signal(SIGHUP, hup);
 235         openlog("rwhod", LOG_PID, LOG_DAEMON);
 236         sp = getservbyname("who", "udp");
 237         if (sp == NULL)
 238                 quit("udp/who: unknown service", WITHOUT_ERRNO);
 239
 240         if (chdir(_PATH_RWHODIR) < 0)
 241                 quit(_PATH_RWHODIR, WITH_ERRNO);
 242
 243         /*
 244          * Establish host name as returned by system.
 245          */
 246         if (gethostname(myname, sizeof(myname)) < 0)
 247                 quit("gethostname", WITH_ERRNO);
 248
 249         if ((cp = strchr(myname, '.')) != NULL)
 250                 *cp = '\0';
 251         strlcpy(mywd.wd_hostname, myname, sizeof(mywd.wd_hostname));
 252         utmpf = open(_PATH_UTMP, O_RDONLY|O_CREAT, 0644);
 253         if (utmpf < 0)
 254                 quit(_PATH_UTMP, WITH_ERRNO);
 255
 256         getboottime();
 257         if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
 258                 quit("socket", WITH_ERRNO);
 259
 260         if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)) < 0)
 261                 quit("setsockopt SO_BROADCAST", WITH_ERRNO);
 262
 263         memset(&m_sin, 0, sizeof(m_sin));
 264         m_sin.sin_len = sizeof(m_sin);
 265         m_sin.sin_family = AF_INET;
 266         m_sin.sin_port = sp->s_port;
 267         if (bind(s, (struct sockaddr *)&m_sin, sizeof(m_sin)) < 0)
 268                 quit("bind", WITH_ERRNO);
 269
 270         setgid(unpriv_gid);
 271         setgroups(1, &unpriv_gid);      /* XXX BOGUS groups[0] = egid */
 272         setuid(unpriv_uid);
 273         if (!configure(s))
 274                 exit(1);
 275
 276         if (!quiet_mode) {
 277                 send_host_information();
 278                 delta = send_time;
 279                 gettimeofday(&now, NULL);
 280                 timeadd(&now, delta, &next);
 281         }
 282
 283         pfd[0].fd = s;
 284         pfd[0].events = POLLIN;
 285
 286         for (;;) {
 287                 int n;
 288
 289                 n = poll(pfd, 1, 1000);
 290
 291                 if (onsighup) {
 292                         onsighup = 0;
 293                         getboottime();
 294                 }
 295
 296                 if (n == 1)
 297                         handleread(s);
 298                 if (!quiet_mode) {
 299                         gettimeofday(&now, NULL);
 300                         if (now.tv_sec > next.tv_sec) {
 301                                 send_host_information();
 302                                 timeadd(&now, delta, &next);
 303                         }
 304                 }
 305         }
 306 }
 307
 308 void
 309 timeadd(struct timeval *now, time_t delta, struct timeval *next)
 310 {
 311         (next)->tv_sec = (now)->tv_sec + delta;
 312 }
 313
 314 void
 315 handleread(int sock)
 316 {
 317         struct sockaddr_in from;
 318         struct stat st;
 319         char path[64];
 320         struct whod wd;
 321         int cc, whod;
 322         socklen_t len = sizeof(from);
 323
 324         cc = recvfrom(sock, (char *)&wd, sizeof(struct whod), 0,
 325                 (struct sockaddr *)&from, &len);
 326         if (cc == 0)
 327                 return;
 328
 329         if (cc < 0 && errno != EINTR) {
 330                 syslog(LOG_WARNING, "recv: %m");
 331                 return;
 332         }
 333
 334         if (from.sin_port != sp->s_port && !insecure_mode) {
 335                 syslog(LOG_WARNING, "%d: bad source port from %s",
 336                     ntohs(from.sin_port), inet_ntoa(from.sin_addr));
 337                 return;
 338         }
 339         if (cc < (int)WHDRSIZE) {
 340                 syslog(LOG_WARNING, "short packet from %s",
 341                     inet_ntoa(from.sin_addr));
 342                 return;
 343         }
 344         if (wd.wd_vers != WHODVERSION)
 345                 return;
 346         if (wd.wd_type != WHODTYPE_STATUS)
 347                 return;
 348         if (!verify(wd.wd_hostname, sizeof wd.wd_hostname)) {
 349                 syslog(LOG_WARNING, "malformed host name from %s",
 350                     inet_ntoa(from.sin_addr));
 351                 return;
 352         }
 353         snprintf(path, sizeof path, "whod.%s", wd.wd_hostname);
 354         /*
 355          * Rather than truncating and growing the file each time,
 356          * use ftruncate if size is less than previous size.
 357          */
 358         whod = open(path, O_WRONLY | O_CREAT, 0644);
 359         if (whod < 0) {
 360                 syslog(LOG_WARNING, "%s: %m", path);
 361                 return;
 362         }
 363 #if ENDIAN != BIG_ENDIAN
 364         {
 365                 int i, n = (cc - WHDRSIZE)/sizeof(struct whoent);
 366                 struct whoent *we;
 367
 368                 /* undo header byte swapping before writing to file */
 369                 wd.wd_sendtime = ntohl(wd.wd_sendtime);
 370                 for (i = 0; i < 3; i++)
 371                         wd.wd_loadav[i] = ntohl(wd.wd_loadav[i]);
 372                 wd.wd_boottime = ntohl(wd.wd_boottime);
 373                 we = wd.wd_we;
 374                 for (i = 0; i < n; i++) {
 375                         we->we_idle = ntohl(we->we_idle);
 376                         we->we_utmp.out_time =
 377                             ntohl(we->we_utmp.out_time);
 378                         we++;
 379                 }
 380         }
 381 #endif
 382         wd.wd_recvtime = time(NULL);
 383         write(whod, (char *)&wd, cc);
 384         if (fstat(whod, &st) < 0 || st.st_size > cc)
 385                 ftruncate(whod, cc);
 386         close(whod);
 387 }
 388
 389 static void
 390 usage(void)
 391 {
 392         fprintf(stderr, "usage: rwhod [-i] [-p] [-l] [-m [ttl]]\n");
 393         exit(1);
 394 }
 395
 396 void
 397 hup(int signo __unused)
 398 {
 399         onsighup = 1;
 400 }
 401
 402 void
 403 run_as(uid_t *uid, gid_t *gid)
 404 {
 405         struct passwd *pw;
 406         struct group *gr;
 407
 408         pw = getpwnam(UNPRIV_USER);
 409         if (!pw)
 410                 quit("getpwnam(daemon)", WITH_ERRNO);
 411
 412         *uid = pw->pw_uid;
 413
 414         gr = getgrnam(UNPRIV_GROUP);
 415         if (!gr)
 416                 quit("getgrnam(daemon)", WITH_ERRNO);
 417
 418         *gid = gr->gr_gid;
 419 }
 420
 421 /*
 422  * Check out host name for unprintables
 423  * and other funnies before allowing a file
 424  * to be created.  Sorry, but blanks aren't allowed.
 425  */
 426 int
 427 verify(char *name, int maxlen)
 428 {
 429         int size = 0;
 430
 431         while (*name && size < maxlen - 1) {
 432                 if (!isascii(*name) || !(isalnum(*name) || ispunct(*name)))
 433                         return (0);
 434                 name++, size++;
 435         }
 436         *name = '\0';
 437         return (size > 0);
 438 }
 439
 440 int     utmptime;
 441 int     utmpent;
 442 int     utmpsize;
 443 struct  utmp *utmp;
 444 int     alarmcount;
 445
 446 void
 447 send_host_information(void)
 448 {
 449         struct neighbor *np;
 450         struct whoent *we = mywd.wd_we, *wlast;
 451         int i;
 452         struct stat stb;
 453         double avenrun[3];
 454         time_t now;
 455         int cc;
 456
 457         now = time(NULL);
 458         if (alarmcount % 10 == 0)
 459                 getboottime();
 460         alarmcount++;
 461         fstat(utmpf, &stb);
 462         if ((stb.st_mtime != utmptime) || (stb.st_size > utmpsize)) {
 463                 utmptime = stb.st_mtime;
 464                 if (stb.st_size > utmpsize) {
 465                         utmpsize = stb.st_size + 10 * sizeof(struct utmp);
 466                         utmp = reallocf(utmp, utmpsize);
 467                         if (utmp == NULL) {
 468                                 syslog(LOG_WARNING, "malloc failed: %m");
 469                                 utmpsize = 0;
 470                                 return;
 471                         }
 472                 }
 473                 lseek(utmpf, (off_t)0, L_SET);
 474                 cc = read(utmpf, (char *)utmp, stb.st_size);
 475                 if (cc < 0) {
 476                         syslog(LOG_ERR, "read(%s): %m", _PATH_UTMP);
 477                         return;
 478                 }
 479                 wlast = &mywd.wd_we[1024 / sizeof(struct whoent) - 1];
 480                 utmpent = cc / sizeof(struct utmp);
 481                 for (i = 0; i < utmpent; i++)
 482                         if (utmp[i].ut_name[0]) {
 483                                 memcpy(we->we_utmp.out_line, utmp[i].ut_line,
 484                                    sizeof(utmp[i].ut_line));
 485                                 memcpy(we->we_utmp.out_name, utmp[i].ut_name,
 486                                    sizeof(utmp[i].ut_name));
 487                                 we->we_utmp.out_time = htonl(utmp[i].ut_time);
 488                                 if (we >= wlast)
 489                                         break;
 490                                 we++;
 491                         }
 492                 utmpent = we - mywd.wd_we;
 493         }
 494
 495         /*
 496          * The test on utmpent looks silly---after all, if no one is
 497          * logged on, why worry about efficiency?---but is useful on
 498          * (e.g.) compute servers.
 499          */
 500         if (utmpent && chdir(_PATH_DEV)) {
 501                 syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV);
 502                 exit(1);
 503         }
 504
 505         we = mywd.wd_we;
 506         for (i = 0; i < utmpent; i++) {
 507                 if (stat(we->we_utmp.out_line, &stb) >= 0)
 508                         we->we_idle = htonl(now - stb.st_atime);
 509                 we++;
 510         }
 511         getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0]));
 512         for (i = 0; i < 3; i++)
 513                 mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100));
 514         cc = (char *)we - (char *)&mywd;
 515         mywd.wd_sendtime = htonl(time(0));
 516         mywd.wd_vers = WHODVERSION;
 517         mywd.wd_type = WHODTYPE_STATUS;
 518         if (multicast_mode == SCOPED_MULTICAST) {
 519                 Sendto(s, (char *)&mywd, cc, 0,
 520                                 (struct sockaddr *)&multicast_addr,
 521                                 sizeof(multicast_addr));
 522         }
 523         else for (np = neighbors; np != NULL; np = np->n_next) {
 524                 if (multicast_mode == PER_INTERFACE_MULTICAST &&
 525                     np->n_flags & IFF_MULTICAST) {
 526                         /*
 527                          * Select the outgoing interface for the multicast.
 528                          */
 529                         if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF,
 530                             &(((struct sockaddr_in *)np->n_addr)->sin_addr),
 531                             sizeof(struct in_addr)) < 0) {
 532                                 quit("setsockopt IP_MULTICAST_IF", WITH_ERRNO);
 533                         }
 534                         Sendto(s, (char *)&mywd, cc, 0,
 535                                 (struct sockaddr *)&multicast_addr,
 536                                 sizeof(multicast_addr));
 537                 } else Sendto(s, (char *)&mywd, cc, 0,
 538                                 np->n_addr, np->n_addrlen);
 539         }
 540         if (utmpent && chdir(_PATH_RWHODIR)) {
 541                 syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR);
 542                 exit(1);
 543         }
 544 }
 545
 546 void
 547 getboottime(void)
 548 {
 549         int mib[2];
 550         size_t size;
 551         struct timeval tm;
 552
 553         mib[0] = CTL_KERN;
 554         mib[1] = KERN_BOOTTIME;
 555         size = sizeof(tm);
 556         if (sysctl(mib, 2, &tm, &size, NULL, 0) == -1)
 557                 quit("cannot get boottime", WITH_ERRNO);
 558
 559         mywd.wd_boottime = htonl(tm.tv_sec);
 560 }
 561
 562 /*
 563  * If wrterrno == WITH_ERRNO, we will print
 564  * errno. If not, we leave errno out.
 565  */
 566 void
 567 quit(const char *msg, int wrterrno)
 568 {
 569         if (wrterrno)
 570                 syslog(LOG_ERR, "%s: %m", msg);
 571         else
 572                 syslog(LOG_ERR, "%s", msg);
 573         exit(1);
 574 }
 575
 576 void
 577 rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo)
 578 {
 579         struct sockaddr *sa;
 580         int i;
 581
 582         memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info));
 583         for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) {
 584                 if ((rtinfo->rti_addrs & (1 << i)) == 0)
 585                         continue;
 586                 rtinfo->rti_info[i] = sa = (struct sockaddr *)cp;
 587                 RT_ADVANCE(cp, sa);
 588         }
 589 }
 590
 591 /*
 592  * Figure out device configuration and select
 593  * networks which deserve status information.
 594  */
 595 int
 596 configure(int c_sock)
 597 {
 598         struct neighbor *np;
 599         struct if_msghdr *ifm;
 600         struct ifa_msghdr *ifam;
 601         struct sockaddr_dl *sdl;
 602         size_t needed;
 603         int mib[6], flags = 0, len;
 604         char *buf, *lim, *next;
 605         struct rt_addrinfo info;
 606
 607         if (multicast_mode != NO_MULTICAST) {
 608                 multicast_addr.sin_len = sizeof(multicast_addr);
 609                 multicast_addr.sin_family = AF_INET;
 610                 multicast_addr.sin_addr.s_addr = htonl(INADDR_WHOD_GROUP);
 611                 multicast_addr.sin_port = sp->s_port;
 612         }
 613
 614         if (multicast_mode == SCOPED_MULTICAST) {
 615                 struct ip_mreq mreq;
 616                 unsigned char ttl;
 617
 618                 mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
 619                 mreq.imr_interface.s_addr = htonl(INADDR_ANY);
 620                 if (setsockopt(c_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 621                                         &mreq, sizeof(mreq)) < 0) {
 622                         syslog(LOG_ERR,
 623                                 "setsockopt IP_ADD_MEMBERSHIP: %m");
 624                         return(0);
 625                 }
 626                 ttl = multicast_scope;
 627                 if (setsockopt(c_sock, IPPROTO_IP, IP_MULTICAST_TTL,
 628                                         &ttl, sizeof(ttl)) < 0) {
 629                         syslog(LOG_ERR,
 630                                 "setsockopt IP_MULTICAST_TTL: %m");
 631                         return(0);
 632                 }
 633                 return(1);
 634         }
 635
 636         mib[0] = CTL_NET;
 637         mib[1] = PF_ROUTE;
 638         mib[2] = 0;
 639         mib[3] = AF_INET;
 640         mib[4] = NET_RT_IFLIST;
 641         mib[5] = 0;
 642         if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
 643                 quit("route-sysctl-estimate", WITH_ERRNO);
 644         if ((buf = malloc(needed)) == NULL)
 645                 quit("malloc", WITH_ERRNO);
 646         if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
 647                 quit("actual retrieval of interface table", WITH_ERRNO);
 648         lim = buf + needed;
 649
 650         sdl = NULL;             /* XXX just to keep gcc -Wall happy */
 651         for (next = buf; next < lim; next += ifm->ifm_msglen) {
 652                 ifm = (struct if_msghdr *)next;
 653                 if (ifm->ifm_type == RTM_IFINFO) {
 654                         sdl = (struct sockaddr_dl *)(ifm + 1);
 655                         flags = ifm->ifm_flags;
 656                         continue;
 657                 }
 658                 if ((flags & IFF_UP) == 0 ||
 659                     (flags & (((multicast_mode == PER_INTERFACE_MULTICAST) ?
 660                                 IFF_MULTICAST : 0) |
 661                                 IFF_BROADCAST|iff_flag)) == 0)
 662                         continue;
 663                 if (ifm->ifm_type != RTM_NEWADDR)
 664                         quit("out of sync parsing NET_RT_IFLIST", WITHOUT_ERRNO);
 665                 ifam = (struct ifa_msghdr *)ifm;
 666                 info.rti_addrs = ifam->ifam_addrs;
 667                 rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam,
 668                         &info);
 669                 /* gag, wish we could get rid of Internet dependencies */
 670 #define dstaddr info.rti_info[RTAX_BRD]
 671 #define ifaddr info.rti_info[RTAX_IFA]
 672 #define IPADDR_SA(x) ((struct sockaddr_in *)(x))->sin_addr.s_addr
 673 #define PORT_SA(x) ((struct sockaddr_in *)(x))->sin_port
 674                 if (dstaddr == 0 || dstaddr->sa_family != AF_INET)
 675                         continue;
 676                 PORT_SA(dstaddr) = sp->s_port;
 677                 for (np = neighbors; np != NULL; np = np->n_next)
 678                         if (memcmp(sdl->sdl_data, np->n_name,
 679                                    sdl->sdl_nlen) == 0 &&
 680                             IPADDR_SA(np->n_addr) == IPADDR_SA(dstaddr))
 681                                 break;
 682                 if (np != NULL)
 683                         continue;
 684                 len = sizeof(*np) + dstaddr->sa_len + sdl->sdl_nlen + 1;
 685                 np = (struct neighbor *)malloc(len);
 686                 if (np == NULL)
 687                         quit("malloc of neighbor structure", WITH_ERRNO);
 688                 memset(np, 0, len);
 689                 np->n_flags = flags;
 690                 np->n_addr = (struct sockaddr *)(np + 1);
 691                 np->n_addrlen = dstaddr->sa_len;
 692                 np->n_name = np->n_addrlen + (char *)np->n_addr;
 693                 memcpy((char *)np->n_addr, (char *)dstaddr, np->n_addrlen);
 694                 memcpy(np->n_name, sdl->sdl_data, sdl->sdl_nlen);
 695                 if (multicast_mode == PER_INTERFACE_MULTICAST &&
 696                     (flags & IFF_MULTICAST) &&
 697                    !(flags & IFF_LOOPBACK)) {
 698                         struct ip_mreq mreq;
 699
 700                         memcpy((char *)np->n_addr, (char *)ifaddr,
 701                                 np->n_addrlen);
 702                         mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
 703                         mreq.imr_interface.s_addr =
 704                           ((struct sockaddr_in *)np->n_addr)->sin_addr.s_addr;
 705                         if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 706                                                 &mreq, sizeof(mreq)) < 0) {
 707                                 syslog(LOG_ERR,
 708                                     "setsockopt IP_ADD_MEMBERSHIP: %m");
 709 #if 0
 710                                 /* Fall back to broadcast on this if. */
 711                                 np->n_flags &= ~IFF_MULTICAST;
 712 #else
 713                                 free((char *)np);
 714                                 continue;
 715 #endif
 716                         }
 717                 }
 718                 np->n_next = neighbors;
 719                 neighbors = np;
 720         }
 721         free(buf);
 722         return (1);
 723 }
 724
 725 #ifdef DEBUG
 726 ssize_t
 727 Sendto(int s_debug, const void *buf, size_t cc, int flags,
 728        const struct sockaddr *to, int tolen)
 729 {
 730         const struct whod *w = (const struct whod *)buf;
 731         const struct whoent *we;
 732         const struct sockaddr_in *sock_in = (const struct sockaddr_in *)to;
 733         ssize_t ret;
 734         int idle_time;
 735
 736         ret = sendto(s_debug, buf, cc, flags, to, tolen);
 737
 738         printf("sendto %s:%d\n", inet_ntoa(sock_in->sin_addr),
 739                                  ntohs(sock_in->sin_port));
 740         printf("hostname %s %s\n", w->wd_hostname,
 741            interval(ntohl(w->wd_sendtime) - ntohl(w->wd_boottime), "  up"));
 742         printf("load %4.2f, %4.2f, %4.2f\n",
 743             ntohl(w->wd_loadav[0]) / 100.0, ntohl(w->wd_loadav[1]) / 100.0,
 744             ntohl(w->wd_loadav[2]) / 100.0);
 745         cc -= WHDRSIZE;
 746         for (we = w->wd_we, cc /= sizeof(struct whoent); cc > 0; cc--, we++) {
 747                 time_t t = ntohl(we->we_utmp.out_time);
 748                 idle_time = we->we_idle;
 749                 printf("%-8.8s %s:%s %.12s",
 750                         we->we_utmp.out_name,
 751                         w->wd_hostname, we->we_utmp.out_line,
 752                         ctime(&t)+4);
 753                 idle_time = ntohl(we->we_idle) / 60;
 754                 if (idle_time) {
 755                         if (idle_time >= 100*60)
 756                                 idle_time = 100*60 - 1;
 757                         if (idle_time >= 60)
 758                                 printf(" %2d", idle_time / 60);
 759                         else
 760                                 printf("   ");
 761                         printf(":%02d", idle_time % 60);
 762                 }
 763                 printf("\n");
 764         }
 765         return(ret);
 766 }
 767
 768 char *
 769 interval(int inter_time, const char *updown)
 770 {
 771         static char resbuf[32];
 772         int days, hours, minutes;
 773
 774         if (inter_time < 0 || inter_time > 3*30*24*60*60) {
 775                 snprintf(resbuf, sizeof(resbuf), "   %s ??:??", updown);
 776                 return (resbuf);
 777         }
 778         minutes = (inter_time + 59) / 60;               /* round to minutes */
 779         hours = minutes / 60; minutes %= 60;
 780         days = hours / 24; hours %= 24;
 781         if (days)
 782                 snprintf(resbuf, sizeof(resbuf), "%s %2d+%02d:%02d",
 783                     updown, days, hours, minutes);
 784         else
 785                 snprintf(resbuf, sizeof(resbuf), "%s    %2d:%02d",
 786                     updown, hours, minutes);
 787         return (resbuf);
 788 }
 789 #endif