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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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  * @(#) Copyright (c) 1983, 1993 The Regents of the University of California.  All rights reserved.
  34  * @(#)rwhod.c  8.1 (Berkeley) 6/6/93
  35  * $FreeBSD: src/usr.sbin/rwhod/rwhod.c,v 1.13.2.2 2000/12/23 15:28:12 iedowse Exp $
  36  * $DragonFly: src/usr.sbin/rwhod/rwhod.c,v 1.24 2007/12/27 15:29:40 matthias Exp $
  37  */
  38
  39 #include <sys/param.h>
  40 #include <sys/socket.h>
  41 #include <sys/stat.h>
  42 #include <sys/signal.h>
  43 #include <sys/ioctl.h>
  44 #include <sys/sysctl.h>
  45
  46 #include <net/if.h>
  47 #include <net/if_dl.h>
  48 #include <net/route.h>
  49 #include <netinet/in.h>
  50 #include <arpa/inet.h>
  51 #include <protocols/rwhod.h>
  52
  53 #include <ctype.h>
  54 #include <err.h>
  55 #include <errno.h>
  56 #include <fcntl.h>
  57 #include <libutil.h>
  58 #include <netdb.h>
  59 #include <paths.h>
  60 #include <poll.h>
  61 #include <stdio.h>
  62 #include <stdlib.h>
  63 #include <string.h>
  64 #include <syslog.h>
  65 #include <unistd.h>
  66 #include <utmp.h>
  67 #include <pwd.h>
  68 #include <grp.h>
  69
  70 /*
  71  * This version of Berkeley's rwhod has been modified to use IP multicast
  72  * datagrams, under control of a new command-line option:
  73  *
  74  *      rwhod -m        causes rwhod to use IP multicast (instead of
  75  *                      broadcast or unicast) on all interfaces that have
  76  *                      the IFF_MULTICAST flag set in their "ifnet" structs
  77  *                      (excluding the loopback interface).  The multicast
  78  *                      reports are sent with a time-to-live of 1, to prevent
  79  *                      forwarding beyond the directly-connected subnet(s).
  80  *
  81  *      rwhod -m <ttl>  causes rwhod to send IP multicast datagrams with a
  82  *                      time-to-live of <ttl>, via a SINGLE interface rather
  83  *                      than all interfaces.  <ttl> must be between 0 and
  84  *                      MAX_MULTICAST_SCOPE, defined below.  Note that "-m 1"
  85  *                      is different than "-m", in that "-m 1" specifies
  86  *                      transmission on one interface only.
  87  *
  88  * When "-m" is used without a <ttl> argument, the program accepts multicast
  89  * rwhod reports from all multicast-capable interfaces.  If a <ttl> argument
  90  * is given, it accepts multicast reports from only one interface, the one
  91  * on which reports are sent (which may be controlled via the host's routing
  92  * table).  Regardless of the "-m" option, the program accepts broadcast or
  93  * unicast reports from all interfaces.  Thus, this program will hear the
  94  * reports of old, non-multicasting rwhods, but, if multicasting is used,
  95  * those old rwhods won't hear the reports generated by this program.
  96  *
  97  *                  -- Steve Deering, Stanford University, February 1989
  98  */
  99
 100 #define UNPRIV_USER             "daemon"
 101 #define UNPRIV_GROUP            "daemon"
 102
 103 #define WITH_ERRNO              1       /* Write to syslog with errno (%m) */
 104 #define WITHOUT_ERRNO           0       /* Write to syslog without errno */
 105
 106 #define NO_MULTICAST            0         /* multicast modes */
 107 #define PER_INTERFACE_MULTICAST 1
 108 #define SCOPED_MULTICAST        2
 109
 110 #define MAX_MULTICAST_SCOPE     32        /* "site-wide", by convention */
 111
 112 #define INADDR_WHOD_GROUP (u_long)0xe0000103      /* 224.0.1.3 */
 113                                           /* (belongs in protocols/rwhod.h) */
 114
 115 int                     insecure_mode;
 116 int                     quiet_mode;
 117 int                     iff_flag = IFF_POINTOPOINT;
 118 int                     multicast_mode  = NO_MULTICAST;
 119 int                     multicast_scope;
 120 struct sockaddr_in      multicast_addr;
 121
 122 char    myname[MAXHOSTNAMELEN];
 123
 124 /*
 125  * We communicate with each neighbor in a list constructed at the time we're
 126  * started up.  Neighbors are currently directly connected via a hardware
 127  * interface.
 128  */
 129 struct  neighbor {
 130         struct  neighbor *n_next;
 131         char    *n_name;                /* interface name */
 132         struct  sockaddr *n_addr;               /* who to send to */
 133         int     n_addrlen;              /* size of address */
 134         int     n_flags;                /* should forward?, interface flags */
 135 };
 136
 137 struct  neighbor *neighbors;
 138 struct  whod mywd;
 139 struct  servent *sp;
 140 int     s, utmpf;
 141 volatile sig_atomic_t   onsighup;
 142
 143 #define WHDRSIZE        (sizeof(mywd) - sizeof(mywd.wd_we))
 144
 145 void     run_as(uid_t *, gid_t *);
 146 int      configure(int);
 147 void     getboottime(void);
 148 void     send_host_information(void);
 149 void     hup(int);
 150 void     quit(const char *, int);
 151 void     rt_xaddrs(caddr_t, caddr_t, struct rt_addrinfo *);
 152 int      verify(char *, int);
 153 void     handleread(int);
 154 static void usage(void);
 155 void     timeadd(struct timeval *, time_t, struct timeval *);
 156
 157 #ifdef DEBUG
 158 char    *interval(int, const char *);
 159 ssize_t Sendto(int, const void *, size_t, int,
 160                      const struct sockaddr *, int);
 161 #else
 162 #define Sendto sendto
 163 #endif
 164
 165 int
 166 main(int argc, char *argv[])
 167 {
 168         struct pollfd pfd[1];
 169         char *ep, *cp;
 170         int on = 1;
 171         int send_time = 180;    /* Default time, 180 seconds (3 minutes) */
 172         struct sockaddr_in m_sin;
 173         uid_t unpriv_uid;
 174         gid_t unpriv_gid;
 175         long tmp;
 176         time_t delta = 0;
 177         struct timeval next, now;
 178
 179         if (getuid())
 180                 errx(1, "not super user");
 181
 182         run_as(&unpriv_uid, &unpriv_gid);
 183
 184         argv++; argc--;
 185         while (argc > 0 && *argv[0] == '-') {
 186                 if (strcmp(*argv, "-m") == 0) {
 187                         if (argc > 1 && *(argv + 1)[0] != '-') {
 188                                 /* Argument has been given */
 189                                 argv++, argc--;
 190                                 multicast_mode = SCOPED_MULTICAST;
 191                                 tmp = strtol(*argv, &ep, 10);
 192                                 if (*ep != '\0' || tmp < INT_MIN || tmp > INT_MAX)
 193                                         errx(1, "invalid ttl: %s", *argv);
 194                                 multicast_scope = (int)tmp;
 195                                 if (multicast_scope > MAX_MULTICAST_SCOPE)
 196                                         errx(1, "ttl must not exceed %u",
 197                                         MAX_MULTICAST_SCOPE);
 198                         }
 199                         else multicast_mode = PER_INTERFACE_MULTICAST;
 200                 } else if (strcmp(*argv, "-g") == 0) {
 201                         if (argc > 1 && *(argv + 1)[0] != '-') {
 202                                 argv++, argc--;
 203                                 send_time = (int)strtol(*argv, &ep, 10);
 204                                 if (send_time <= 0)
 205                                         errx(1, "time must be greater than 0");
 206
 207                                 if (ep[0] != '\0') {
 208                                         if (ep[1] != '\0')
 209                                                 errx(1, "invalid argument: %s", *argv);
 210                                         if (*ep == 'M' || *ep == 'm') {
 211                                                 /* Time in minutes. */
 212                                                 send_time *= 60;
 213                                         } else
 214                                                 errx(1, "invalid argument: %s", *argv);
 215                                 }
 216
 217                                 if (send_time > 180)
 218                                         errx(1, "cannot be greater than 180 seconds (3 minutes)");
 219                         } else
 220                                 errx(1, "missing argument");
 221                 } else if (strcmp(*argv, "-i") == 0)
 222                         insecure_mode = 1;
 223                 else if (strcmp(*argv, "-l") == 0)
 224                         quiet_mode = 1;
 225                 else if (strcmp(*argv, "-p") == 0)
 226                         iff_flag = 0;
 227                 else
 228                         usage();
 229                 argv++, argc--;
 230         }
 231         if (argc > 0)
 232                 usage();
 233 #ifndef DEBUG
 234         daemon(1, 0);
 235         pidfile(NULL);
 236 #endif
 237         signal(SIGHUP, hup);
 238         openlog("rwhod", LOG_PID, LOG_DAEMON);
 239         sp = getservbyname("who", "udp");
 240         if (sp == NULL)
 241                 quit("udp/who: unknown service", WITHOUT_ERRNO);
 242
 243         if (chdir(_PATH_RWHODIR) < 0)
 244                 quit(_PATH_RWHODIR, WITH_ERRNO);
 245
 246         /*
 247          * Establish host name as returned by system.
 248          */
 249         if (gethostname(myname, sizeof(myname)) < 0)
 250                 quit("gethostname", WITH_ERRNO);
 251
 252         if ((cp = strchr(myname, '.')) != NULL)
 253                 *cp = '\0';
 254         strlcpy(mywd.wd_hostname, myname, sizeof(mywd.wd_hostname));
 255         utmpf = open(_PATH_UTMP, O_RDONLY|O_CREAT, 0644);
 256         if (utmpf < 0)
 257                 quit(_PATH_UTMP, WITH_ERRNO);
 258
 259         getboottime();
 260         if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
 261                 quit("socket", WITH_ERRNO);
 262
 263         if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)) < 0)
 264                 quit("setsockopt SO_BROADCAST", WITH_ERRNO);
 265
 266         memset(&m_sin, 0, sizeof(m_sin));
 267         m_sin.sin_len = sizeof(m_sin);
 268         m_sin.sin_family = AF_INET;
 269         m_sin.sin_port = sp->s_port;
 270         if (bind(s, (struct sockaddr *)&m_sin, sizeof(m_sin)) < 0)
 271                 quit("bind", WITH_ERRNO);
 272
 273         setgid(unpriv_gid);
 274         setgroups(1, &unpriv_gid);      /* XXX BOGUS groups[0] = egid */
 275         setuid(unpriv_uid);
 276         if (!configure(s))
 277                 exit(1);
 278
 279         if (!quiet_mode) {
 280                 send_host_information();
 281                 delta = send_time;
 282                 gettimeofday(&now, NULL);
 283                 timeadd(&now, delta, &next);
 284         }
 285
 286         pfd[0].fd = s;
 287         pfd[0].events = POLLIN;
 288
 289         for (;;) {
 290                 int n;
 291
 292                 n = poll(pfd, 1, 1000);
 293
 294                 if (onsighup) {
 295                         onsighup = 0;
 296                         getboottime();
 297                 }
 298
 299                 if (n == 1)
 300                         handleread(s);
 301                 if (!quiet_mode) {
 302                         gettimeofday(&now, NULL);
 303                         if (now.tv_sec > next.tv_sec) {
 304                                 send_host_information();
 305                                 timeadd(&now, delta, &next);
 306                         }
 307                 }
 308         }
 309 }
 310
 311 void
 312 timeadd(struct timeval *now, time_t delta, struct timeval *next)
 313 {
 314         (next)->tv_sec = (now)->tv_sec + delta;
 315 }
 316
 317 void
 318 handleread(int sock)
 319 {
 320         struct sockaddr_in from;
 321         struct stat st;
 322         char path[64];
 323         struct whod wd;
 324         int cc, whod;
 325         socklen_t len = sizeof(from);
 326
 327         cc = recvfrom(sock, (char *)&wd, sizeof(struct whod), 0,
 328                 (struct sockaddr *)&from, &len);
 329         if (cc == 0)
 330                 return;
 331
 332         if (cc < 0 && errno != EINTR) {
 333                 syslog(LOG_WARNING, "recv: %m");
 334                 return;
 335         }
 336
 337         if (from.sin_port != sp->s_port && !insecure_mode) {
 338                 syslog(LOG_WARNING, "%d: bad source port from %s",
 339                     ntohs(from.sin_port), inet_ntoa(from.sin_addr));
 340                 return;
 341         }
 342         if (cc < (int)WHDRSIZE) {
 343                 syslog(LOG_WARNING, "short packet from %s",
 344                     inet_ntoa(from.sin_addr));
 345                 return;
 346         }
 347         if (wd.wd_vers != WHODVERSION)
 348                 return;
 349         if (wd.wd_type != WHODTYPE_STATUS)
 350                 return;
 351         if (!verify(wd.wd_hostname, sizeof wd.wd_hostname)) {
 352                 syslog(LOG_WARNING, "malformed host name from %s",
 353                     inet_ntoa(from.sin_addr));
 354                 return;
 355         }
 356         snprintf(path, sizeof path, "whod.%s", wd.wd_hostname);
 357         /*
 358          * Rather than truncating and growing the file each time,
 359          * use ftruncate if size is less than previous size.
 360          */
 361         whod = open(path, O_WRONLY | O_CREAT, 0644);
 362         if (whod < 0) {
 363                 syslog(LOG_WARNING, "%s: %m", path);
 364                 return;
 365         }
 366 #if ENDIAN != BIG_ENDIAN
 367         {
 368                 int i, n = (cc - WHDRSIZE)/sizeof(struct whoent);
 369                 struct whoent *we;
 370
 371                 /* undo header byte swapping before writing to file */
 372                 wd.wd_sendtime = ntohl(wd.wd_sendtime);
 373                 for (i = 0; i < 3; i++)
 374                         wd.wd_loadav[i] = ntohl(wd.wd_loadav[i]);
 375                 wd.wd_boottime = ntohl(wd.wd_boottime);
 376                 we = wd.wd_we;
 377                 for (i = 0; i < n; i++) {
 378                         we->we_idle = ntohl(we->we_idle);
 379                         we->we_utmp.out_time =
 380                             ntohl(we->we_utmp.out_time);
 381                         we++;
 382                 }
 383         }
 384 #endif
 385         time((time_t *)&wd.wd_recvtime);
 386         write(whod, (char *)&wd, cc);
 387         if (fstat(whod, &st) < 0 || st.st_size > cc)
 388                 ftruncate(whod, cc);
 389         close(whod);
 390 }
 391
 392 static void
 393 usage(void)
 394 {
 395         fprintf(stderr, "usage: rwhod [-i] [-p] [-l] [-m [ttl]]\n");
 396         exit(1);
 397 }
 398
 399 void
 400 hup(int signo __unused)
 401 {
 402         onsighup = 1;
 403 }
 404
 405 void
 406 run_as(uid_t *uid, gid_t *gid)
 407 {
 408         struct passwd *pw;
 409         struct group *gr;
 410
 411         pw = getpwnam(UNPRIV_USER);
 412         if (!pw)
 413                 quit("getpwnam(daemon)", WITH_ERRNO);
 414
 415         *uid = pw->pw_uid;
 416
 417         gr = getgrnam(UNPRIV_GROUP);
 418         if (!gr)
 419                 quit("getgrnam(daemon)", WITH_ERRNO);
 420
 421         *gid = gr->gr_gid;
 422 }
 423
 424 /*
 425  * Check out host name for unprintables
 426  * and other funnies before allowing a file
 427  * to be created.  Sorry, but blanks aren't allowed.
 428  */
 429 int
 430 verify(char *name, int maxlen)
 431 {
 432         int size = 0;
 433
 434         while (*name && size < maxlen - 1) {
 435                 if (!isascii(*name) || !(isalnum(*name) || ispunct(*name)))
 436                         return (0);
 437                 name++, size++;
 438         }
 439         *name = '\0';
 440         return (size > 0);
 441 }
 442
 443 int     utmptime;
 444 int     utmpent;
 445 int     utmpsize;
 446 struct  utmp *utmp;
 447 int     alarmcount;
 448
 449 void
 450 send_host_information(void)
 451 {
 452         struct neighbor *np;
 453         struct whoent *we = mywd.wd_we, *wlast;
 454         int i;
 455         struct stat stb;
 456         double avenrun[3];
 457         time_t now;
 458         int cc;
 459
 460         now = time(NULL);
 461         if (alarmcount % 10 == 0)
 462                 getboottime();
 463         alarmcount++;
 464         fstat(utmpf, &stb);
 465         if ((stb.st_mtime != utmptime) || (stb.st_size > utmpsize)) {
 466                 utmptime = stb.st_mtime;
 467                 if (stb.st_size > utmpsize) {
 468                         utmpsize = stb.st_size + 10 * sizeof(struct utmp);
 469                         utmp = reallocf(utmp, utmpsize);
 470                         if (utmp == NULL) {
 471                                 syslog(LOG_WARNING, "malloc failed: %m");
 472                                 utmpsize = 0;
 473                                 return;
 474                         }
 475                 }
 476                 lseek(utmpf, (off_t)0, L_SET);
 477                 cc = read(utmpf, (char *)utmp, stb.st_size);
 478                 if (cc < 0) {
 479                         syslog(LOG_ERR, "read(%s): %m", _PATH_UTMP);
 480                         return;
 481                 }
 482                 wlast = &mywd.wd_we[1024 / sizeof(struct whoent) - 1];
 483                 utmpent = cc / sizeof(struct utmp);
 484                 for (i = 0; i < utmpent; i++)
 485                         if (utmp[i].ut_name[0]) {
 486                                 memcpy(we->we_utmp.out_line, utmp[i].ut_line,
 487                                    sizeof(utmp[i].ut_line));
 488                                 memcpy(we->we_utmp.out_name, utmp[i].ut_name,
 489                                    sizeof(utmp[i].ut_name));
 490                                 we->we_utmp.out_time = htonl(utmp[i].ut_time);
 491                                 if (we >= wlast)
 492                                         break;
 493                                 we++;
 494                         }
 495                 utmpent = we - mywd.wd_we;
 496         }
 497
 498         /*
 499          * The test on utmpent looks silly---after all, if no one is
 500          * logged on, why worry about efficiency?---but is useful on
 501          * (e.g.) compute servers.
 502          */
 503         if (utmpent && chdir(_PATH_DEV)) {
 504                 syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV);
 505                 exit(1);
 506         }
 507
 508         we = mywd.wd_we;
 509         for (i = 0; i < utmpent; i++) {
 510                 if (stat(we->we_utmp.out_line, &stb) >= 0)
 511                         we->we_idle = htonl(now - stb.st_atime);
 512                 we++;
 513         }
 514         getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0]));
 515         for (i = 0; i < 3; i++)
 516                 mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100));
 517         cc = (char *)we - (char *)&mywd;
 518         mywd.wd_sendtime = htonl(time(0));
 519         mywd.wd_vers = WHODVERSION;
 520         mywd.wd_type = WHODTYPE_STATUS;
 521         if (multicast_mode == SCOPED_MULTICAST) {
 522                 Sendto(s, (char *)&mywd, cc, 0,
 523                                 (struct sockaddr *)&multicast_addr,
 524                                 sizeof(multicast_addr));
 525         }
 526         else for (np = neighbors; np != NULL; np = np->n_next) {
 527                 if (multicast_mode == PER_INTERFACE_MULTICAST &&
 528                     np->n_flags & IFF_MULTICAST) {
 529                         /*
 530                          * Select the outgoing interface for the multicast.
 531                          */
 532                         if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF,
 533                             &(((struct sockaddr_in *)np->n_addr)->sin_addr),
 534                             sizeof(struct in_addr)) < 0) {
 535                                 quit("setsockopt IP_MULTICAST_IF", WITH_ERRNO);
 536                         }
 537                         Sendto(s, (char *)&mywd, cc, 0,
 538                                 (struct sockaddr *)&multicast_addr,
 539                                 sizeof(multicast_addr));
 540                 } else Sendto(s, (char *)&mywd, cc, 0,
 541                                 np->n_addr, np->n_addrlen);
 542         }
 543         if (utmpent && chdir(_PATH_RWHODIR)) {
 544                 syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR);
 545                 exit(1);
 546         }
 547 }
 548
 549 void
 550 getboottime(void)
 551 {
 552         int mib[2];
 553         size_t size;
 554         struct timeval tm;
 555
 556         mib[0] = CTL_KERN;
 557         mib[1] = KERN_BOOTTIME;
 558         size = sizeof(tm);
 559         if (sysctl(mib, 2, &tm, &size, NULL, 0) == -1)
 560                 quit("cannot get boottime", WITH_ERRNO);
 561
 562         mywd.wd_boottime = htonl(tm.tv_sec);
 563 }
 564
 565 /*
 566  * If wrterrno == WITH_ERRNO, we will print
 567  * errno. If not, we leave errno out.
 568  */
 569 void
 570 quit(const char *msg, int wrterrno)
 571 {
 572         if (wrterrno)
 573                 syslog(LOG_ERR, "%s: %m", msg);
 574         else
 575                 syslog(LOG_ERR, "%s", msg);
 576         exit(1);
 577 }
 578
 579 #define ROUNDUP(a) \
 580         ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
 581 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
 582
 583 void
 584 rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo)
 585 {
 586         struct sockaddr *sa;
 587         int i;
 588
 589         memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info));
 590         for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) {
 591                 if ((rtinfo->rti_addrs & (1 << i)) == 0)
 592                         continue;
 593                 rtinfo->rti_info[i] = sa = (struct sockaddr *)cp;
 594                 ADVANCE(cp, sa);
 595         }
 596 }
 597
 598 /*
 599  * Figure out device configuration and select
 600  * networks which deserve status information.
 601  */
 602 int
 603 configure(int c_sock)
 604 {
 605         struct neighbor *np;
 606         struct if_msghdr *ifm;
 607         struct ifa_msghdr *ifam;
 608         struct sockaddr_dl *sdl;
 609         size_t needed;
 610         int mib[6], flags = 0, len;
 611         char *buf, *lim, *next;
 612         struct rt_addrinfo info;
 613
 614         if (multicast_mode != NO_MULTICAST) {
 615                 multicast_addr.sin_len = sizeof(multicast_addr);
 616                 multicast_addr.sin_family = AF_INET;
 617                 multicast_addr.sin_addr.s_addr = htonl(INADDR_WHOD_GROUP);
 618                 multicast_addr.sin_port = sp->s_port;
 619         }
 620
 621         if (multicast_mode == SCOPED_MULTICAST) {
 622                 struct ip_mreq mreq;
 623                 unsigned char ttl;
 624
 625                 mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
 626                 mreq.imr_interface.s_addr = htonl(INADDR_ANY);
 627                 if (setsockopt(c_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 628                                         &mreq, sizeof(mreq)) < 0) {
 629                         syslog(LOG_ERR,
 630                                 "setsockopt IP_ADD_MEMBERSHIP: %m");
 631                         return(0);
 632                 }
 633                 ttl = multicast_scope;
 634                 if (setsockopt(c_sock, IPPROTO_IP, IP_MULTICAST_TTL,
 635                                         &ttl, sizeof(ttl)) < 0) {
 636                         syslog(LOG_ERR,
 637                                 "setsockopt IP_MULTICAST_TTL: %m");
 638                         return(0);
 639                 }
 640                 return(1);
 641         }
 642
 643         mib[0] = CTL_NET;
 644         mib[1] = PF_ROUTE;
 645         mib[2] = 0;
 646         mib[3] = AF_INET;
 647         mib[4] = NET_RT_IFLIST;
 648         mib[5] = 0;
 649         if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
 650                 quit("route-sysctl-estimate", WITH_ERRNO);
 651         if ((buf = malloc(needed)) == NULL)
 652                 quit("malloc", WITH_ERRNO);
 653         if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
 654                 quit("actual retrieval of interface table", WITH_ERRNO);
 655         lim = buf + needed;
 656
 657         sdl = NULL;             /* XXX just to keep gcc -Wall happy */
 658         for (next = buf; next < lim; next += ifm->ifm_msglen) {
 659                 ifm = (struct if_msghdr *)next;
 660                 if (ifm->ifm_type == RTM_IFINFO) {
 661                         sdl = (struct sockaddr_dl *)(ifm + 1);
 662                         flags = ifm->ifm_flags;
 663                         continue;
 664                 }
 665                 if ((flags & IFF_UP) == 0 ||
 666                     (flags & (((multicast_mode == PER_INTERFACE_MULTICAST) ?
 667                                 IFF_MULTICAST : 0) |
 668                                 IFF_BROADCAST|iff_flag)) == 0)
 669                         continue;
 670                 if (ifm->ifm_type != RTM_NEWADDR)
 671                         quit("out of sync parsing NET_RT_IFLIST", WITHOUT_ERRNO);
 672                 ifam = (struct ifa_msghdr *)ifm;
 673                 info.rti_addrs = ifam->ifam_addrs;
 674                 rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam,
 675                         &info);
 676                 /* gag, wish we could get rid of Internet dependencies */
 677 #define dstaddr info.rti_info[RTAX_BRD]
 678 #define ifaddr info.rti_info[RTAX_IFA]
 679 #define IPADDR_SA(x) ((struct sockaddr_in *)(x))->sin_addr.s_addr
 680 #define PORT_SA(x) ((struct sockaddr_in *)(x))->sin_port
 681                 if (dstaddr == 0 || dstaddr->sa_family != AF_INET)
 682                         continue;
 683                 PORT_SA(dstaddr) = sp->s_port;
 684                 for (np = neighbors; np != NULL; np = np->n_next)
 685                         if (memcmp(sdl->sdl_data, np->n_name,
 686                                    sdl->sdl_nlen) == 0 &&
 687                             IPADDR_SA(np->n_addr) == IPADDR_SA(dstaddr))
 688                                 break;
 689                 if (np != NULL)
 690                         continue;
 691                 len = sizeof(*np) + dstaddr->sa_len + sdl->sdl_nlen + 1;
 692                 np = (struct neighbor *)malloc(len);
 693                 if (np == NULL)
 694                         quit("malloc of neighbor structure", WITH_ERRNO);
 695                 memset(np, 0, len);
 696                 np->n_flags = flags;
 697                 np->n_addr = (struct sockaddr *)(np + 1);
 698                 np->n_addrlen = dstaddr->sa_len;
 699                 np->n_name = np->n_addrlen + (char *)np->n_addr;
 700                 memcpy((char *)np->n_addr, (char *)dstaddr, np->n_addrlen);
 701                 memcpy(np->n_name, sdl->sdl_data, sdl->sdl_nlen);
 702                 if (multicast_mode == PER_INTERFACE_MULTICAST &&
 703                     (flags & IFF_MULTICAST) &&
 704                    !(flags & IFF_LOOPBACK)) {
 705                         struct ip_mreq mreq;
 706
 707                         memcpy((char *)np->n_addr, (char *)ifaddr,
 708                                 np->n_addrlen);
 709                         mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
 710                         mreq.imr_interface.s_addr =
 711                           ((struct sockaddr_in *)np->n_addr)->sin_addr.s_addr;
 712                         if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 713                                                 &mreq, sizeof(mreq)) < 0) {
 714                                 syslog(LOG_ERR,
 715                                     "setsockopt IP_ADD_MEMBERSHIP: %m");
 716 #if 0
 717                                 /* Fall back to broadcast on this if. */
 718                                 np->n_flags &= ~IFF_MULTICAST;
 719 #else
 720                                 free((char *)np);
 721                                 continue;
 722 #endif
 723                         }
 724                 }
 725                 np->n_next = neighbors;
 726                 neighbors = np;
 727         }
 728         free(buf);
 729         return (1);
 730 }
 731
 732 #ifdef DEBUG
 733 ssize_t
 734 Sendto(int s_debug, const void *buf, size_t cc, int flags,
 735        const struct sockaddr *to, int tolen)
 736 {
 737         const struct whod *w = (const struct whod *)buf;
 738         const struct whoent *we;
 739         const struct sockaddr_in *sock_in = (const struct sockaddr_in *)to;
 740         ssize_t ret;
 741         int idle_time;
 742
 743         ret = sendto(s_debug, buf, cc, flags, to, tolen);
 744
 745         printf("sendto %s:%d\n", inet_ntoa(sock_in->sin_addr),
 746                                  ntohs(sock_in->sin_port));
 747         printf("hostname %s %s\n", w->wd_hostname,
 748            interval(ntohl(w->wd_sendtime) - ntohl(w->wd_boottime), "  up"));
 749         printf("load %4.2f, %4.2f, %4.2f\n",
 750             ntohl(w->wd_loadav[0]) / 100.0, ntohl(w->wd_loadav[1]) / 100.0,
 751             ntohl(w->wd_loadav[2]) / 100.0);
 752         cc -= WHDRSIZE;
 753         for (we = w->wd_we, cc /= sizeof(struct whoent); cc > 0; cc--, we++) {
 754                 time_t t = ntohl(we->we_utmp.out_time);
 755                 idle_time = we->we_idle;
 756                 printf("%-8.8s %s:%s %.12s",
 757                         we->we_utmp.out_name,
 758                         w->wd_hostname, we->we_utmp.out_line,
 759                         ctime(&t)+4);
 760                 idle_time = ntohl(we->we_idle) / 60;
 761                 if (idle_time) {
 762                         if (idle_time >= 100*60)
 763                                 idle_time = 100*60 - 1;
 764                         if (idle_time >= 60)
 765                                 printf(" %2d", idle_time / 60);
 766                         else
 767                                 printf("   ");
 768                         printf(":%02d", idle_time % 60);
 769                 }
 770                 printf("\n");
 771         }
 772         return(ret);
 773 }
 774
 775 char *
 776 interval(int inter_time, const char *updown)
 777 {
 778         static char resbuf[32];
 779         int days, hours, minutes;
 780
 781         if (inter_time < 0 || inter_time > 3*30*24*60*60) {
 782                 snprintf(resbuf, sizeof(resbuf), "   %s ??:??", updown);
 783                 return (resbuf);
 784         }
 785         minutes = (inter_time + 59) / 60;               /* round to minutes */
 786         hours = minutes / 60; minutes %= 60;
 787         days = hours / 24; hours %= 24;
 788         if (days)
 789                 snprintf(resbuf, sizeof(resbuf), "%s %2d+%02d:%02d",
 790                     updown, days, hours, minutes);
 791         else
 792                 snprintf(resbuf, sizeof(resbuf), "%s    %2d:%02d",
 793                     updown, hours, minutes);
 794         return (resbuf);
 795 }
 796 #endif