rwhod.tproj/rwhod.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.0 (the 'License').  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License."
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 /*
  25  * Copyright (c) 1983, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * Redistribution and use in source and binary forms, with or without
  29  * modification, are permitted provided that the following conditions
  30  * are met:
  31  * 1. Redistributions of source code must retain the above copyright
  32  *    notice, this list of conditions and the following disclaimer.
  33  * 2. Redistributions in binary form must reproduce the above copyright
  34  *    notice, this list of conditions and the following disclaimer in the
  35  *    documentation and/or other materials provided with the distribution.
  36  * 3. All advertising materials mentioning features or use of this software
  37  *    must display the following acknowledgement:
  38  *      This product includes software developed by the University of
  39  *      California, Berkeley and its contributors.
  40  * 4. Neither the name of the University nor the names of its contributors
  41  *    may be used to endorse or promote products derived from this software
  42  *    without specific prior written permission.
  43  *
  44  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  45  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  46  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  47  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  48  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  49  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  50  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  51  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  52  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  53  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  54  * SUCH DAMAGE.
  55  */
  56
  57 #ifndef lint
  58 static char copyright[] =
  59 "@(#) Copyright (c) 1983, 1993\n\
  60         The Regents of the University of California.  All rights reserved.\n";
  61 #endif /* not lint */
  62
  63 #ifndef lint
  64 static char sccsid[] = "@(#)rwhod.c     8.1 (Berkeley) 6/6/93";
  65 #endif /* not lint */
  66
  67 #include <sys/param.h>
  68 #include <sys/socket.h>
  69 #include <sys/stat.h>
  70 #include <sys/signal.h>
  71 #include <sys/ioctl.h>
  72 #include <sys/sysctl.h>
  73
  74 #include <net/if.h>
  75 #include <net/if_dl.h>
  76 #include <net/route.h>
  77 #include <netinet/in.h>
  78 #include <arpa/inet.h>
  79 #include <protocols/rwhod.h>
  80
  81 #include <ctype.h>
  82 #include <errno.h>
  83 #include <fcntl.h>
  84 #include <netdb.h>
  85 #include <paths.h>
  86 #include <stdio.h>
  87 #include <stdlib.h>
  88 #include <string.h>
  89 #include <syslog.h>
  90 #include <unistd.h>
  91 #include <utmp.h>
  92
  93 /*
  94  * Alarm interval. Don't forget to change the down time check in ruptime
  95  * if this is changed.
  96  */
  97 #define AL_INTERVAL (3 * 60)
  98
  99 char    myname[MAXHOSTNAMELEN];
 100
 101 /*
 102  * We communicate with each neighbor in a list constructed at the time we're
 103  * started up.  Neighbors are currently directly connected via a hardware
 104  * interface.
 105  */
 106 struct  neighbor {
 107         struct  neighbor *n_next;
 108         char    *n_name;                /* interface name */
 109         struct  sockaddr *n_addr;               /* who to send to */
 110         int     n_addrlen;              /* size of address */
 111         int     n_flags;                /* should forward?, interface flags */
 112 };
 113
 114 struct  neighbor *neighbors;
 115 struct  whod mywd;
 116 struct  servent *sp;
 117 int     s, utmpf;
 118
 119 #define WHDRSIZE        (sizeof(mywd) - sizeof(mywd.wd_we))
 120
 121 int      configure __P((int));
 122 void     getboottime __P((int));
 123 void     onalrm __P((int));
 124 void     quit __P((char *));
 125 void     rt_xaddrs __P((caddr_t, caddr_t, struct rt_addrinfo *));
 126 int      verify __P((char *));
 127 #ifdef DEBUG
 128 char    *interval __P((int, char *));
 129 void     Sendto __P((int, char *, int, int, char *, int));
 130 #define  sendto Sendto
 131 #endif
 132
 133 int
 134 main(argc, argv)
 135         int argc;
 136         char argv[];
 137 {
 138         struct sockaddr_in from;
 139         struct stat st;
 140         char path[64];
 141         int on = 1;
 142         char *cp;
 143         struct sockaddr_in sin;
 144
 145         if (getuid()) {
 146                 fprintf(stderr, "rwhod: not super user\n");
 147                 exit(1);
 148         }
 149         sp = getservbyname("who", "udp");
 150         if (sp == NULL) {
 151                 fprintf(stderr, "rwhod: udp/who: unknown service\n");
 152                 exit(1);
 153         }
 154 #ifndef DEBUG
 155         daemon(1, 0);
 156 #endif
 157         if (chdir(_PATH_RWHODIR) < 0) {
 158                 (void)fprintf(stderr, "rwhod: %s: %s\n",
 159                     _PATH_RWHODIR, strerror(errno));
 160                 exit(1);
 161         }
 162         (void) signal(SIGHUP, getboottime);
 163         openlog("rwhod", LOG_PID, LOG_DAEMON);
 164         /*
 165          * Establish host name as returned by system.
 166          */
 167         if (gethostname(myname, sizeof(myname) - 1) < 0) {
 168                 syslog(LOG_ERR, "gethostname: %m");
 169                 exit(1);
 170         }
 171         if ((cp = index(myname, '.')) != NULL)
 172                 *cp = '\0';
 173         strncpy(mywd.wd_hostname, myname, sizeof(myname) - 1);
 174         utmpf = open(_PATH_UTMP, O_RDONLY|O_CREAT, 0644);
 175         if (utmpf < 0) {
 176                 syslog(LOG_ERR, "%s: %m", _PATH_UTMP);
 177                 exit(1);
 178         }
 179         getboottime(0);
 180         if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
 181                 syslog(LOG_ERR, "socket: %m");
 182                 exit(1);
 183         }
 184         if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)) < 0) {
 185                 syslog(LOG_ERR, "setsockopt SO_BROADCAST: %m");
 186                 exit(1);
 187         }
 188         memset(&sin, 0, sizeof(sin));
 189         sin.sin_family = AF_INET;
 190         sin.sin_port = sp->s_port;
 191         if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
 192                 syslog(LOG_ERR, "bind: %m");
 193                 exit(1);
 194         }
 195         if (!configure(s))
 196                 exit(1);
 197         signal(SIGALRM, onalrm);
 198         onalrm(0);
 199         for (;;) {
 200                 struct whod wd;
 201                 int cc, whod, len = sizeof(from);
 202
 203                 cc = recvfrom(s, (char *)&wd, sizeof(struct whod), 0,
 204                         (struct sockaddr *)&from, &len);
 205                 if (cc <= 0) {
 206                         if (cc < 0 && errno != EINTR)
 207                                 syslog(LOG_WARNING, "recv: %m");
 208                         continue;
 209                 }
 210                 if (from.sin_port != sp->s_port) {
 211                        syslog(LOG_WARNING, "%d: bad source port from %s",
 212                            ntohs(from.sin_port), inet_ntoa(from.sin_addr));
 213                         continue;
 214                 }
 215                 if (cc < WHDRSIZE) {
 216                        syslog(LOG_WARNING, "short packet from %s",
 217                            inet_ntoa(from.sin_addr));
 218                        continue;
 219                 }
 220
 221                 if (wd.wd_vers != WHODVERSION)
 222                         continue;
 223                 if (wd.wd_type != WHODTYPE_STATUS)
 224                         continue;
 225                 if (!verify(wd.wd_hostname)) {
 226                        syslog(LOG_WARNING, "malformed host name from %s",
 227                            inet_ntoa(from.sin_addr));
 228                         continue;
 229                 }
 230                 (void) sprintf(path, "whod.%s", wd.wd_hostname);
 231                 /*
 232                  * Rather than truncating and growing the file each time,
 233                  * use ftruncate if size is less than previous size.
 234                  */
 235                 whod = open(path, O_WRONLY | O_CREAT, 0644);
 236                 if (whod < 0) {
 237                         syslog(LOG_WARNING, "%s: %m", path);
 238                         continue;
 239                 }
 240 #if ENDIAN != BIG_ENDIAN
 241                 {
 242                         int i, n = (cc - WHDRSIZE)/sizeof(struct whoent);
 243                         struct whoent *we;
 244
 245                         /* undo header byte swapping before writing to file */
 246                         wd.wd_sendtime = ntohl(wd.wd_sendtime);
 247                         for (i = 0; i < 3; i++)
 248                                 wd.wd_loadav[i] = ntohl(wd.wd_loadav[i]);
 249                         wd.wd_boottime = ntohl(wd.wd_boottime);
 250                         we = wd.wd_we;
 251                         for (i = 0; i < n; i++) {
 252                                 we->we_idle = ntohl(we->we_idle);
 253                                 we->we_utmp.out_time =
 254                                     ntohl(we->we_utmp.out_time);
 255                                 we++;
 256                         }
 257                 }
 258 #endif
 259                 (void) time((time_t *)&wd.wd_recvtime);
 260                 (void) write(whod, (char *)&wd, cc);
 261                 if (fstat(whod, &st) < 0 || st.st_size > cc)
 262                         ftruncate(whod, cc);
 263                 (void) close(whod);
 264         }
 265 }
 266
 267 /*
 268  * Check out host name for unprintables
 269  * and other funnies before allowing a file
 270  * to be created.  Sorry, but blanks aren't allowed.
 271  */
 272 int
 273 verify(name)
 274         register char *name;
 275 {
 276         register int size = 0;
 277
 278         while (*name) {
 279                 if (!isascii(*name) || !(isalnum(*name) || ispunct(*name)))
 280                         return (0);
 281                 name++, size++;
 282         }
 283         return (size > 0);
 284 }
 285
 286 int     utmptime;
 287 int     utmpent;
 288 int     utmpsize = 0;
 289 struct  utmp *utmp;
 290 int     alarmcount;
 291
 292 void
 293 onalrm(signo)
 294         int signo;
 295 {
 296         register struct neighbor *np;
 297         register struct whoent *we = mywd.wd_we, *wlast;
 298         register int i;
 299         struct stat stb;
 300         double avenrun[3];
 301         time_t now;
 302         int cc;
 303
 304         now = time(NULL);
 305         if (alarmcount % 10 == 0)
 306                 getboottime(0);
 307         alarmcount++;
 308         (void) fstat(utmpf, &stb);
 309         if ((stb.st_mtime != utmptime) || (stb.st_size > utmpsize)) {
 310                 utmptime = stb.st_mtime;
 311                 if (stb.st_size > utmpsize) {
 312                         utmpsize = stb.st_size + 10 * sizeof(struct utmp);
 313                         if (utmp)
 314                                 utmp = (struct utmp *)realloc(utmp, utmpsize);
 315                         else
 316                                 utmp = (struct utmp *)malloc(utmpsize);
 317                         if (! utmp) {
 318                                 fprintf(stderr, "rwhod: malloc failed\n");
 319                                 utmpsize = 0;
 320                                 goto done;
 321                         }
 322                 }
 323                 (void) lseek(utmpf, (off_t)0, L_SET);
 324                 cc = read(utmpf, (char *)utmp, stb.st_size);
 325                 if (cc < 0) {
 326                         fprintf(stderr, "rwhod: %s: %s\n",
 327                             _PATH_UTMP, strerror(errno));
 328                         goto done;
 329                 }
 330                 wlast = &mywd.wd_we[1024 / sizeof(struct whoent) - 1];
 331                 utmpent = cc / sizeof(struct utmp);
 332                 for (i = 0; i < utmpent; i++)
 333                         if (utmp[i].ut_name[0]) {
 334                                 memcpy(we->we_utmp.out_line, utmp[i].ut_line,
 335                                    sizeof(utmp[i].ut_line));
 336                                 memcpy(we->we_utmp.out_name, utmp[i].ut_name,
 337                                    sizeof(utmp[i].ut_name));
 338                                 we->we_utmp.out_time = htonl(utmp[i].ut_time);
 339                                 if (we >= wlast)
 340                                         break;
 341                                 we++;
 342                         }
 343                 utmpent = we - mywd.wd_we;
 344         }
 345
 346         /*
 347          * The test on utmpent looks silly---after all, if no one is
 348          * logged on, why worry about efficiency?---but is useful on
 349          * (e.g.) compute servers.
 350          */
 351         if (utmpent && chdir(_PATH_DEV)) {
 352                 syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV);
 353                 exit(1);
 354         }
 355         we = mywd.wd_we;
 356         for (i = 0; i < utmpent; i++) {
 357                 if (stat(we->we_utmp.out_line, &stb) >= 0)
 358                         we->we_idle = htonl(now - stb.st_atime);
 359                 we++;
 360         }
 361         (void)getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0]));
 362         for (i = 0; i < 3; i++)
 363                 mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100));
 364         cc = (char *)we - (char *)&mywd;
 365         mywd.wd_sendtime = htonl(time(0));
 366         mywd.wd_vers = WHODVERSION;
 367         mywd.wd_type = WHODTYPE_STATUS;
 368         for (np = neighbors; np != NULL; np = np->n_next)
 369                 (void)sendto(s, (char *)&mywd, cc, 0,
 370                                 np->n_addr, np->n_addrlen);
 371         if (utmpent && chdir(_PATH_RWHODIR)) {
 372                 syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR);
 373                 exit(1);
 374         }
 375 done:
 376         (void) alarm(AL_INTERVAL);
 377 }
 378
 379 void
 380 getboottime(signo)
 381         int signo;
 382 {
 383         int mib[2];
 384         size_t size;
 385         struct timeval tm;
 386
 387         mib[0] = CTL_KERN;
 388         mib[1] = KERN_BOOTTIME;
 389         size = sizeof(tm);
 390         if (sysctl(mib, 2, &tm, &size, NULL, 0) == -1) {
 391                 syslog(LOG_ERR, "cannot get boottime: %m");
 392                 exit(1);
 393         }
 394         mywd.wd_boottime = htonl(tm.tv_sec);
 395 }
 396
 397 void
 398 quit(msg)
 399         char *msg;
 400 {
 401         syslog(LOG_ERR, msg);
 402         exit(1);
 403 }
 404
 405 #define ROUNDUP(a) \
 406         ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
 407 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
 408
 409 void
 410 rt_xaddrs(cp, cplim, rtinfo)
 411         register caddr_t cp, cplim;
 412         register struct rt_addrinfo *rtinfo;
 413 {
 414         register struct sockaddr *sa;
 415         register int i;
 416
 417         memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info));
 418         for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) {
 419                 if ((rtinfo->rti_addrs & (1 << i)) == 0)
 420                         continue;
 421                 rtinfo->rti_info[i] = sa = (struct sockaddr *)cp;
 422                 ADVANCE(cp, sa);
 423         }
 424 }
 425
 426 /*
 427  * Figure out device configuration and select
 428  * networks which deserve status information.
 429  */
 430 int
 431 configure(s)
 432         int s;
 433 {
 434         register struct neighbor *np;
 435         register struct if_msghdr *ifm;
 436         register struct ifa_msghdr *ifam;
 437         struct sockaddr_dl *sdl;
 438         size_t needed;
 439         int mib[6], flags = 0, len;
 440         char *buf, *lim, *next;
 441         struct rt_addrinfo info;
 442
 443         mib[0] = CTL_NET;
 444         mib[1] = PF_ROUTE;
 445         mib[2] = 0;
 446         mib[3] = AF_INET;
 447         mib[4] = NET_RT_IFLIST;
 448         mib[5] = 0;
 449         if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
 450                 quit("route-sysctl-estimate");
 451         if ((buf = malloc(needed)) == NULL)
 452                 quit("malloc");
 453         if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
 454                 quit("actual retrieval of interface table");
 455         lim = buf + needed;
 456
 457         sdl = NULL;             /* XXX just to keep gcc -Wall happy */
 458         for (next = buf; next < lim; next += ifm->ifm_msglen) {
 459                 ifm = (struct if_msghdr *)next;
 460                 if (ifm->ifm_type == RTM_IFINFO) {
 461                         sdl = (struct sockaddr_dl *)(ifm + 1);
 462                         flags = ifm->ifm_flags;
 463                         continue;
 464                 }
 465                 if ((flags & IFF_UP) == 0 ||
 466                     (flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)
 467                         continue;
 468                 if (ifm->ifm_type != RTM_NEWADDR)
 469                         quit("out of sync parsing NET_RT_IFLIST");
 470                 ifam = (struct ifa_msghdr *)ifm;
 471                 info.rti_addrs = ifam->ifam_addrs;
 472                 rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam,
 473                         &info);
 474                 /* gag, wish we could get rid of Internet dependencies */
 475 #define dstaddr info.rti_info[RTAX_BRD]
 476 #define IPADDR_SA(x) ((struct sockaddr_in *)(x))->sin_addr.s_addr
 477 #define PORT_SA(x) ((struct sockaddr_in *)(x))->sin_port
 478                 if (dstaddr == 0 || dstaddr->sa_family != AF_INET)
 479                         continue;
 480                 PORT_SA(dstaddr) = sp->s_port;
 481                 for (np = neighbors; np != NULL; np = np->n_next)
 482                         if (memcmp(sdl->sdl_data, np->n_name,
 483                                    sdl->sdl_nlen) == 0 &&
 484                             IPADDR_SA(np->n_addr) == IPADDR_SA(dstaddr))
 485                                 break;
 486                 if (np != NULL)
 487                         continue;
 488                 len = sizeof(*np) + dstaddr->sa_len + sdl->sdl_nlen + 1;
 489                 np = (struct neighbor *)malloc(len);
 490                 if (np == NULL)
 491                         quit("malloc of neighbor structure");
 492                 memset(np, 0, len);
 493                 np->n_flags = flags;
 494                 np->n_addr = (struct sockaddr *)(np + 1);
 495                 np->n_addrlen = dstaddr->sa_len;
 496                 np->n_name = np->n_addrlen + (char *)np->n_addr;
 497                 np->n_next = neighbors;
 498                 neighbors = np;
 499                 memcpy((char *)np->n_addr, (char *)dstaddr, np->n_addrlen);
 500                 memcpy(np->n_name, sdl->sdl_data, sdl->sdl_nlen);
 501         }
 502         free(buf);
 503         return (1);
 504 }
 505
 506 #ifdef DEBUG
 507 void
 508 Sendto(s, buf, cc, flags, to, tolen)
 509         int s;
 510         char *buf;
 511         int cc, flags;
 512         char *to;
 513         int tolen;
 514 {
 515         register struct whod *w = (struct whod *)buf;
 516         register struct whoent *we;
 517         struct sockaddr_in *sin = (struct sockaddr_in *)to;
 518
 519         printf("sendto %x.%d\n", ntohl(sin->sin_addr), ntohs(sin->sin_port));
 520         printf("hostname %s %s\n", w->wd_hostname,
 521            interval(ntohl(w->wd_sendtime) - ntohl(w->wd_boottime), "  up"));
 522         printf("load %4.2f, %4.2f, %4.2f\n",
 523             ntohl(w->wd_loadav[0]) / 100.0, ntohl(w->wd_loadav[1]) / 100.0,
 524             ntohl(w->wd_loadav[2]) / 100.0);
 525         cc -= WHDRSIZE;
 526         for (we = w->wd_we, cc /= sizeof(struct whoent); cc > 0; cc--, we++) {
 527                 time_t t = ntohl(we->we_utmp.out_time);
 528                 printf("%-8.8s %s:%s %.12s",
 529                         we->we_utmp.out_name,
 530                         w->wd_hostname, we->we_utmp.out_line,
 531                         ctime(&t)+4);
 532                 we->we_idle = ntohl(we->we_idle) / 60;
 533                 if (we->we_idle) {
 534                         if (we->we_idle >= 100*60)
 535                                 we->we_idle = 100*60 - 1;
 536                         if (we->we_idle >= 60)
 537                                 printf(" %2d", we->we_idle / 60);
 538                         else
 539                                 printf("   ");
 540                         printf(":%02d", we->we_idle % 60);
 541                 }
 542                 printf("\n");
 543         }
 544 }
 545
 546 char *
 547 interval(time, updown)
 548         int time;
 549         char *updown;
 550 {
 551         static char resbuf[32];
 552         int days, hours, minutes;
 553
 554         if (time < 0 || time > 3*30*24*60*60) {
 555                 (void) sprintf(resbuf, "   %s ??:??", updown);
 556                 return (resbuf);
 557         }
 558         minutes = (time + 59) / 60;             /* round to minutes */
 559         hours = minutes / 60; minutes %= 60;
 560         days = hours / 24; hours %= 24;
 561         if (days)
 562                 (void) sprintf(resbuf, "%s %2d+%02d:%02d",
 563                     updown, days, hours, minutes);
 564         else
 565                 (void) sprintf(resbuf, "%s    %2d:%02d",
 566                     updown, hours, minutes);
 567         return (resbuf);
 568 }
 569 #endif