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 <protocols/rwhod.h>
  79
  80 #include <ctype.h>
  81 #include <errno.h>
  82 #include <fcntl.h>
  83 #include <netdb.h>
  84 #include <paths.h>
  85 #include <stdio.h>
  86 #include <stdlib.h>
  87 #include <string.h>
  88 #include <syslog.h>
  89 #include <unistd.h>
  90 #include <utmp.h>
  91
  92 /*
  93  * Alarm interval. Don't forget to change the down time check in ruptime
  94  * if this is changed.
  95  */
  96 #define AL_INTERVAL (3 * 60)
  97
  98 char    myname[MAXHOSTNAMELEN];
  99
 100 /*
 101  * We communicate with each neighbor in a list constructed at the time we're
 102  * started up.  Neighbors are currently directly connected via a hardware
 103  * interface.
 104  */
 105 struct  neighbor {
 106         struct  neighbor *n_next;
 107         char    *n_name;                /* interface name */
 108         struct  sockaddr *n_addr;               /* who to send to */
 109         int     n_addrlen;              /* size of address */
 110         int     n_flags;                /* should forward?, interface flags */
 111 };
 112
 113 struct  neighbor *neighbors;
 114 struct  whod mywd;
 115 struct  servent *sp;
 116 int     s, utmpf;
 117
 118 #define WHDRSIZE        (sizeof(mywd) - sizeof(mywd.wd_we))
 119
 120 int      configure __P((int));
 121 void     getboottime __P((int));
 122 void     onalrm __P((int));
 123 void     quit __P((char *));
 124 void     rt_xaddrs __P((caddr_t, caddr_t, struct rt_addrinfo *));
 125 int      verify __P((char *));
 126 #ifdef DEBUG
 127 char    *interval __P((int, char *));
 128 void     Sendto __P((int, char *, int, int, char *, int));
 129 #define  sendto Sendto
 130 #endif
 131
 132 int
 133 main(argc, argv)
 134         int argc;
 135         char argv[];
 136 {
 137         struct sockaddr_in from;
 138         struct stat st;
 139         char path[64];
 140         int on = 1;
 141         char *cp;
 142         struct sockaddr_in sin;
 143
 144         if (getuid()) {
 145                 fprintf(stderr, "rwhod: not super user\n");
 146                 exit(1);
 147         }
 148         sp = getservbyname("who", "udp");
 149         if (sp == NULL) {
 150                 fprintf(stderr, "rwhod: udp/who: unknown service\n");
 151                 exit(1);
 152         }
 153 #ifndef DEBUG
 154         daemon(1, 0);
 155 #endif
 156         if (chdir(_PATH_RWHODIR) < 0) {
 157                 (void)fprintf(stderr, "rwhod: %s: %s\n",
 158                     _PATH_RWHODIR, strerror(errno));
 159                 exit(1);
 160         }
 161         (void) signal(SIGHUP, getboottime);
 162         openlog("rwhod", LOG_PID, LOG_DAEMON);
 163         /*
 164          * Establish host name as returned by system.
 165          */
 166         if (gethostname(myname, sizeof(myname) - 1) < 0) {
 167                 syslog(LOG_ERR, "gethostname: %m");
 168                 exit(1);
 169         }
 170         if ((cp = index(myname, '.')) != NULL)
 171                 *cp = '\0';
 172         strncpy(mywd.wd_hostname, myname, sizeof(myname) - 1);
 173         utmpf = open(_PATH_UTMP, O_RDONLY|O_CREAT, 0644);
 174         if (utmpf < 0) {
 175                 syslog(LOG_ERR, "%s: %m", _PATH_UTMP);
 176                 exit(1);
 177         }
 178         getboottime(0);
 179         if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
 180                 syslog(LOG_ERR, "socket: %m");
 181                 exit(1);
 182         }
 183         if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)) < 0) {
 184                 syslog(LOG_ERR, "setsockopt SO_BROADCAST: %m");
 185                 exit(1);
 186         }
 187         memset(&sin, 0, sizeof(sin));
 188         sin.sin_family = AF_INET;
 189         sin.sin_port = sp->s_port;
 190         if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
 191                 syslog(LOG_ERR, "bind: %m");
 192                 exit(1);
 193         }
 194         if (!configure(s))
 195                 exit(1);
 196         signal(SIGALRM, onalrm);
 197         onalrm(0);
 198         for (;;) {
 199                 struct whod wd;
 200                 int cc, whod, len = sizeof(from);
 201
 202                 cc = recvfrom(s, (char *)&wd, sizeof(struct whod), 0,
 203                         (struct sockaddr *)&from, &len);
 204                 if (cc <= 0) {
 205                         if (cc < 0 && errno != EINTR)
 206                                 syslog(LOG_WARNING, "recv: %m");
 207                         continue;
 208                 }
 209                 if (from.sin_port != sp->s_port) {
 210                         syslog(LOG_WARNING, "%d: bad from port",
 211                                 ntohs(from.sin_port));
 212                         continue;
 213                 }
 214                 if (wd.wd_vers != WHODVERSION)
 215                         continue;
 216                 if (wd.wd_type != WHODTYPE_STATUS)
 217                         continue;
 218                 if (!verify(wd.wd_hostname)) {
 219                         syslog(LOG_WARNING, "malformed host name from %x",
 220                                 from.sin_addr);
 221                         continue;
 222                 }
 223                 (void) sprintf(path, "whod.%s", wd.wd_hostname);
 224                 /*
 225                  * Rather than truncating and growing the file each time,
 226                  * use ftruncate if size is less than previous size.
 227                  */
 228                 whod = open(path, O_WRONLY | O_CREAT, 0644);
 229                 if (whod < 0) {
 230                         syslog(LOG_WARNING, "%s: %m", path);
 231                         continue;
 232                 }
 233 #if ENDIAN != BIG_ENDIAN
 234                 {
 235                         int i, n = (cc - WHDRSIZE)/sizeof(struct whoent);
 236                         struct whoent *we;
 237
 238                         /* undo header byte swapping before writing to file */
 239                         wd.wd_sendtime = ntohl(wd.wd_sendtime);
 240                         for (i = 0; i < 3; i++)
 241                                 wd.wd_loadav[i] = ntohl(wd.wd_loadav[i]);
 242                         wd.wd_boottime = ntohl(wd.wd_boottime);
 243                         we = wd.wd_we;
 244                         for (i = 0; i < n; i++) {
 245                                 we->we_idle = ntohl(we->we_idle);
 246                                 we->we_utmp.out_time =
 247                                     ntohl(we->we_utmp.out_time);
 248                                 we++;
 249                         }
 250                 }
 251 #endif
 252                 (void) time((time_t *)&wd.wd_recvtime);
 253                 (void) write(whod, (char *)&wd, cc);
 254                 if (fstat(whod, &st) < 0 || st.st_size > cc)
 255                         ftruncate(whod, cc);
 256                 (void) close(whod);
 257         }
 258 }
 259
 260 /*
 261  * Check out host name for unprintables
 262  * and other funnies before allowing a file
 263  * to be created.  Sorry, but blanks aren't allowed.
 264  */
 265 int
 266 verify(name)
 267         register char *name;
 268 {
 269         register int size = 0;
 270
 271         while (*name) {
 272                 if (!isascii(*name) || !(isalnum(*name) || ispunct(*name)))
 273                         return (0);
 274                 name++, size++;
 275         }
 276         return (size > 0);
 277 }
 278
 279 int     utmptime;
 280 int     utmpent;
 281 int     utmpsize = 0;
 282 struct  utmp *utmp;
 283 int     alarmcount;
 284
 285 void
 286 onalrm(signo)
 287         int signo;
 288 {
 289         register struct neighbor *np;
 290         register struct whoent *we = mywd.wd_we, *wlast;
 291         register int i;
 292         struct stat stb;
 293         double avenrun[3];
 294         time_t now;
 295         int cc;
 296
 297         now = time(NULL);
 298         if (alarmcount % 10 == 0)
 299                 getboottime(0);
 300         alarmcount++;
 301         (void) fstat(utmpf, &stb);
 302         if ((stb.st_mtime != utmptime) || (stb.st_size > utmpsize)) {
 303                 utmptime = stb.st_mtime;
 304                 if (stb.st_size > utmpsize) {
 305                         utmpsize = stb.st_size + 10 * sizeof(struct utmp);
 306                         if (utmp)
 307                                 utmp = (struct utmp *)realloc(utmp, utmpsize);
 308                         else
 309                                 utmp = (struct utmp *)malloc(utmpsize);
 310                         if (! utmp) {
 311                                 fprintf(stderr, "rwhod: malloc failed\n");
 312                                 utmpsize = 0;
 313                                 goto done;
 314                         }
 315                 }
 316                 (void) lseek(utmpf, (off_t)0, L_SET);
 317                 cc = read(utmpf, (char *)utmp, stb.st_size);
 318                 if (cc < 0) {
 319                         fprintf(stderr, "rwhod: %s: %s\n",
 320                             _PATH_UTMP, strerror(errno));
 321                         goto done;
 322                 }
 323                 wlast = &mywd.wd_we[1024 / sizeof(struct whoent) - 1];
 324                 utmpent = cc / sizeof(struct utmp);
 325                 for (i = 0; i < utmpent; i++)
 326                         if (utmp[i].ut_name[0]) {
 327                                 memcpy(we->we_utmp.out_line, utmp[i].ut_line,
 328                                    sizeof(utmp[i].ut_line));
 329                                 memcpy(we->we_utmp.out_name, utmp[i].ut_name,
 330                                    sizeof(utmp[i].ut_name));
 331                                 we->we_utmp.out_time = htonl(utmp[i].ut_time);
 332                                 if (we >= wlast)
 333                                         break;
 334                                 we++;
 335                         }
 336                 utmpent = we - mywd.wd_we;
 337         }
 338
 339         /*
 340          * The test on utmpent looks silly---after all, if no one is
 341          * logged on, why worry about efficiency?---but is useful on
 342          * (e.g.) compute servers.
 343          */
 344         if (utmpent && chdir(_PATH_DEV)) {
 345                 syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV);
 346                 exit(1);
 347         }
 348         we = mywd.wd_we;
 349         for (i = 0; i < utmpent; i++) {
 350                 if (stat(we->we_utmp.out_line, &stb) >= 0)
 351                         we->we_idle = htonl(now - stb.st_atime);
 352                 we++;
 353         }
 354         (void)getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0]));
 355         for (i = 0; i < 3; i++)
 356                 mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100));
 357         cc = (char *)we - (char *)&mywd;
 358         mywd.wd_sendtime = htonl(time(0));
 359         mywd.wd_vers = WHODVERSION;
 360         mywd.wd_type = WHODTYPE_STATUS;
 361         for (np = neighbors; np != NULL; np = np->n_next)
 362                 (void)sendto(s, (char *)&mywd, cc, 0,
 363                                 np->n_addr, np->n_addrlen);
 364         if (utmpent && chdir(_PATH_RWHODIR)) {
 365                 syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR);
 366                 exit(1);
 367         }
 368 done:
 369         (void) alarm(AL_INTERVAL);
 370 }
 371
 372 void
 373 getboottime(signo)
 374         int signo;
 375 {
 376         int mib[2];
 377         size_t size;
 378         struct timeval tm;
 379
 380         mib[0] = CTL_KERN;
 381         mib[1] = KERN_BOOTTIME;
 382         size = sizeof(tm);
 383         if (sysctl(mib, 2, &tm, &size, NULL, 0) == -1) {
 384                 syslog(LOG_ERR, "cannot get boottime: %m");
 385                 exit(1);
 386         }
 387         mywd.wd_boottime = htonl(tm.tv_sec);
 388 }
 389
 390 void
 391 quit(msg)
 392         char *msg;
 393 {
 394         syslog(LOG_ERR, msg);
 395         exit(1);
 396 }
 397
 398 #define ROUNDUP(a) \
 399         ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
 400 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
 401
 402 void
 403 rt_xaddrs(cp, cplim, rtinfo)
 404         register caddr_t cp, cplim;
 405         register struct rt_addrinfo *rtinfo;
 406 {
 407         register struct sockaddr *sa;
 408         register int i;
 409
 410         memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info));
 411         for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) {
 412                 if ((rtinfo->rti_addrs & (1 << i)) == 0)
 413                         continue;
 414                 rtinfo->rti_info[i] = sa = (struct sockaddr *)cp;
 415                 ADVANCE(cp, sa);
 416         }
 417 }
 418
 419 /*
 420  * Figure out device configuration and select
 421  * networks which deserve status information.
 422  */
 423 int
 424 configure(s)
 425         int s;
 426 {
 427         register struct neighbor *np;
 428         register struct if_msghdr *ifm;
 429         register struct ifa_msghdr *ifam;
 430         struct sockaddr_dl *sdl;
 431         size_t needed;
 432         int mib[6], flags = 0, len;
 433         char *buf, *lim, *next;
 434         struct rt_addrinfo info;
 435
 436         mib[0] = CTL_NET;
 437         mib[1] = PF_ROUTE;
 438         mib[2] = 0;
 439         mib[3] = AF_INET;
 440         mib[4] = NET_RT_IFLIST;
 441         mib[5] = 0;
 442         if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
 443                 quit("route-sysctl-estimate");
 444         if ((buf = malloc(needed)) == NULL)
 445                 quit("malloc");
 446         if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
 447                 quit("actual retrieval of interface table");
 448         lim = buf + needed;
 449
 450         sdl = NULL;             /* XXX just to keep gcc -Wall happy */
 451         for (next = buf; next < lim; next += ifm->ifm_msglen) {
 452                 ifm = (struct if_msghdr *)next;
 453                 if (ifm->ifm_type == RTM_IFINFO) {
 454                         sdl = (struct sockaddr_dl *)(ifm + 1);
 455                         flags = ifm->ifm_flags;
 456                         continue;
 457                 }
 458                 if ((flags & IFF_UP) == 0 ||
 459                     (flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)
 460                         continue;
 461                 if (ifm->ifm_type != RTM_NEWADDR)
 462                         quit("out of sync parsing NET_RT_IFLIST");
 463                 ifam = (struct ifa_msghdr *)ifm;
 464                 info.rti_addrs = ifam->ifam_addrs;
 465                 rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam,
 466                         &info);
 467                 /* gag, wish we could get rid of Internet dependencies */
 468 #define dstaddr info.rti_info[RTAX_BRD]
 469 #define IPADDR_SA(x) ((struct sockaddr_in *)(x))->sin_addr.s_addr
 470 #define PORT_SA(x) ((struct sockaddr_in *)(x))->sin_port
 471                 if (dstaddr == 0 || dstaddr->sa_family != AF_INET)
 472                         continue;
 473                 PORT_SA(dstaddr) = sp->s_port;
 474                 for (np = neighbors; np != NULL; np = np->n_next)
 475                         if (memcmp(sdl->sdl_data, np->n_name,
 476                                    sdl->sdl_nlen) == 0 &&
 477                             IPADDR_SA(np->n_addr) == IPADDR_SA(dstaddr))
 478                                 break;
 479                 if (np != NULL)
 480                         continue;
 481                 len = sizeof(*np) + dstaddr->sa_len + sdl->sdl_nlen + 1;
 482                 np = (struct neighbor *)malloc(len);
 483                 if (np == NULL)
 484                         quit("malloc of neighbor structure");
 485                 memset(np, 0, len);
 486                 np->n_flags = flags;
 487                 np->n_addr = (struct sockaddr *)(np + 1);
 488                 np->n_addrlen = dstaddr->sa_len;
 489                 np->n_name = np->n_addrlen + (char *)np->n_addr;
 490                 np->n_next = neighbors;
 491                 neighbors = np;
 492                 memcpy((char *)np->n_addr, (char *)dstaddr, np->n_addrlen);
 493                 memcpy(np->n_name, sdl->sdl_data, sdl->sdl_nlen);
 494         }
 495         free(buf);
 496         return (1);
 497 }
 498
 499 #ifdef DEBUG
 500 void
 501 Sendto(s, buf, cc, flags, to, tolen)
 502         int s;
 503         char *buf;
 504         int cc, flags;
 505         char *to;
 506         int tolen;
 507 {
 508         register struct whod *w = (struct whod *)buf;
 509         register struct whoent *we;
 510         struct sockaddr_in *sin = (struct sockaddr_in *)to;
 511
 512         printf("sendto %x.%d\n", ntohl(sin->sin_addr), ntohs(sin->sin_port));
 513         printf("hostname %s %s\n", w->wd_hostname,
 514            interval(ntohl(w->wd_sendtime) - ntohl(w->wd_boottime), "  up"));
 515         printf("load %4.2f, %4.2f, %4.2f\n",
 516             ntohl(w->wd_loadav[0]) / 100.0, ntohl(w->wd_loadav[1]) / 100.0,
 517             ntohl(w->wd_loadav[2]) / 100.0);
 518         cc -= WHDRSIZE;
 519         for (we = w->wd_we, cc /= sizeof(struct whoent); cc > 0; cc--, we++) {
 520                 time_t t = ntohl(we->we_utmp.out_time);
 521                 printf("%-8.8s %s:%s %.12s",
 522                         we->we_utmp.out_name,
 523                         w->wd_hostname, we->we_utmp.out_line,
 524                         ctime(&t)+4);
 525                 we->we_idle = ntohl(we->we_idle) / 60;
 526                 if (we->we_idle) {
 527                         if (we->we_idle >= 100*60)
 528                                 we->we_idle = 100*60 - 1;
 529                         if (we->we_idle >= 60)
 530                                 printf(" %2d", we->we_idle / 60);
 531                         else
 532                                 printf("   ");
 533                         printf(":%02d", we->we_idle % 60);
 534                 }
 535                 printf("\n");
 536         }
 537 }
 538
 539 char *
 540 interval(time, updown)
 541         int time;
 542         char *updown;
 543 {
 544         static char resbuf[32];
 545         int days, hours, minutes;
 546
 547         if (time < 0 || time > 3*30*24*60*60) {
 548                 (void) sprintf(resbuf, "   %s ??:??", updown);
 549                 return (resbuf);
 550         }
 551         minutes = (time + 59) / 60;             /* round to minutes */
 552         hours = minutes / 60; minutes %= 60;
 553         days = hours / 24; hours %= 24;
 554         if (days)
 555                 (void) sprintf(resbuf, "%s %2d+%02d:%02d",
 556                     updown, days, hours, minutes);
 557         else
 558                 (void) sprintf(resbuf, "%s    %2d:%02d",
 559                     updown, hours, minutes);
 560         return (resbuf);
 561 }
 562 #endif