rwhod.tproj/rwhod.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * Copyright (c) 1983, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * Redistribution and use in source and binary forms, with or without
  28  * modification, are permitted provided that the following conditions
  29  * are met:
  30  * 1. Redistributions of source code must retain the above copyright
  31  *    notice, this list of conditions and the following disclaimer.
  32  * 2. Redistributions in binary form must reproduce the above copyright
  33  *    notice, this list of conditions and the following disclaimer in the
  34  *    documentation and/or other materials provided with the distribution.
  35  * 3. All advertising materials mentioning features or use of this software
  36  *    must display the following acknowledgement:
  37  *      This product includes software developed by the University of
  38  *      California, Berkeley and its contributors.
  39  * 4. Neither the name of the University nor the names of its contributors
  40  *    may be used to endorse or promote products derived from this software
  41  *    without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  53  * SUCH DAMAGE.
  54  */
  55
  56 #ifndef lint
  57 static char copyright[] =
  58 "@(#) Copyright (c) 1983, 1993\n\
  59         The Regents of the University of California.  All rights reserved.\n";
  60 #endif /* not lint */
  61
  62 #ifndef lint
  63 static char sccsid[] = "@(#)rwhod.c     8.1 (Berkeley) 6/6/93";
  64 #endif /* not lint */
  65
  66 #include <sys/param.h>
  67 #include <sys/socket.h>
  68 #include <sys/stat.h>
  69 #include <sys/signal.h>
  70 #include <sys/ioctl.h>
  71 #include <sys/sysctl.h>
  72
  73 #include <net/if.h>
  74 #include <net/if_dl.h>
  75 #include <net/route.h>
  76 #include <netinet/in.h>
  77 #include <arpa/inet.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 source port from %s",
 211                            ntohs(from.sin_port), inet_ntoa(from.sin_addr));
 212                         continue;
 213                 }
 214                 if (cc < WHDRSIZE) {
 215                        syslog(LOG_WARNING, "short packet from %s",
 216                            inet_ntoa(from.sin_addr));
 217                        continue;
 218                 }
 219
 220                 if (wd.wd_vers != WHODVERSION)
 221                         continue;
 222                 if (wd.wd_type != WHODTYPE_STATUS)
 223                         continue;
 224                 if (!verify(wd.wd_hostname)) {
 225                        syslog(LOG_WARNING, "malformed host name from %s",
 226                            inet_ntoa(from.sin_addr));
 227                         continue;
 228                 }
 229                 (void) sprintf(path, "whod.%s", wd.wd_hostname);
 230                 /*
 231                  * Rather than truncating and growing the file each time,
 232                  * use ftruncate if size is less than previous size.
 233                  */
 234                 whod = open(path, O_WRONLY | O_CREAT, 0644);
 235                 if (whod < 0) {
 236                         syslog(LOG_WARNING, "%s: %m", path);
 237                         continue;
 238                 }
 239 #if ENDIAN != BIG_ENDIAN
 240                 {
 241                         int i, n = (cc - WHDRSIZE)/sizeof(struct whoent);
 242                         struct whoent *we;
 243
 244                         /* undo header byte swapping before writing to file */
 245                         wd.wd_sendtime = ntohl(wd.wd_sendtime);
 246                         for (i = 0; i < 3; i++)
 247                                 wd.wd_loadav[i] = ntohl(wd.wd_loadav[i]);
 248                         wd.wd_boottime = ntohl(wd.wd_boottime);
 249                         we = wd.wd_we;
 250                         for (i = 0; i < n; i++) {
 251                                 we->we_idle = ntohl(we->we_idle);
 252                                 we->we_utmp.out_time =
 253                                     ntohl(we->we_utmp.out_time);
 254                                 we++;
 255                         }
 256                 }
 257 #endif
 258                 (void) time((time_t *)&wd.wd_recvtime);
 259                 (void) write(whod, (char *)&wd, cc);
 260                 if (fstat(whod, &st) < 0 || st.st_size > cc)
 261                         ftruncate(whod, cc);
 262                 (void) close(whod);
 263         }
 264 }
 265
 266 /*
 267  * Check out host name for unprintables
 268  * and other funnies before allowing a file
 269  * to be created.  Sorry, but blanks aren't allowed.
 270  */
 271 int
 272 verify(name)
 273         register char *name;
 274 {
 275         register int size = 0;
 276
 277         while (*name) {
 278                 if (!isascii(*name) || !(isalnum(*name) || ispunct(*name)))
 279                         return (0);
 280                 name++, size++;
 281         }
 282         return (size > 0);
 283 }
 284
 285 int     utmptime;
 286 int     utmpent;
 287 int     utmpsize = 0;
 288 struct  utmp *utmp;
 289 int     alarmcount;
 290
 291 void
 292 onalrm(signo)
 293         int signo;
 294 {
 295         register struct neighbor *np;
 296         register struct whoent *we = mywd.wd_we, *wlast;
 297         register int i;
 298         struct stat stb;
 299         double avenrun[3];
 300         time_t now;
 301         int cc;
 302
 303         now = time(NULL);
 304         if (alarmcount % 10 == 0)
 305                 getboottime(0);
 306         alarmcount++;
 307         (void) fstat(utmpf, &stb);
 308         if ((stb.st_mtime != utmptime) || (stb.st_size > utmpsize)) {
 309                 utmptime = stb.st_mtime;
 310                 if (stb.st_size > utmpsize) {
 311                         utmpsize = stb.st_size + 10 * sizeof(struct utmp);
 312                         if (utmp)
 313                                 utmp = (struct utmp *)realloc(utmp, utmpsize);
 314                         else
 315                                 utmp = (struct utmp *)malloc(utmpsize);
 316                         if (! utmp) {
 317                                 fprintf(stderr, "rwhod: malloc failed\n");
 318                                 utmpsize = 0;
 319                                 goto done;
 320                         }
 321                 }
 322                 (void) lseek(utmpf, (off_t)0, L_SET);
 323                 cc = read(utmpf, (char *)utmp, stb.st_size);
 324                 if (cc < 0) {
 325                         fprintf(stderr, "rwhod: %s: %s\n",
 326                             _PATH_UTMP, strerror(errno));
 327                         goto done;
 328                 }
 329                 wlast = &mywd.wd_we[1024 / sizeof(struct whoent) - 1];
 330                 utmpent = cc / sizeof(struct utmp);
 331                 for (i = 0; i < utmpent; i++)
 332                         if (utmp[i].ut_name[0]) {
 333                                 memcpy(we->we_utmp.out_line, utmp[i].ut_line,
 334                                    sizeof(utmp[i].ut_line));
 335                                 memcpy(we->we_utmp.out_name, utmp[i].ut_name,
 336                                    sizeof(utmp[i].ut_name));
 337                                 we->we_utmp.out_time = htonl(utmp[i].ut_time);
 338                                 if (we >= wlast)
 339                                         break;
 340                                 we++;
 341                         }
 342                 utmpent = we - mywd.wd_we;
 343         }
 344
 345         /*
 346          * The test on utmpent looks silly---after all, if no one is
 347          * logged on, why worry about efficiency?---but is useful on
 348          * (e.g.) compute servers.
 349          */
 350         if (utmpent && chdir(_PATH_DEV)) {
 351                 syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV);
 352                 exit(1);
 353         }
 354         we = mywd.wd_we;
 355         for (i = 0; i < utmpent; i++) {
 356                 if (stat(we->we_utmp.out_line, &stb) >= 0)
 357                         we->we_idle = htonl(now - stb.st_atime);
 358                 we++;
 359         }
 360         (void)getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0]));
 361         for (i = 0; i < 3; i++)
 362                 mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100));
 363         cc = (char *)we - (char *)&mywd;
 364         mywd.wd_sendtime = htonl(time(0));
 365         mywd.wd_vers = WHODVERSION;
 366         mywd.wd_type = WHODTYPE_STATUS;
 367         for (np = neighbors; np != NULL; np = np->n_next)
 368                 (void)sendto(s, (char *)&mywd, cc, 0,
 369                                 np->n_addr, np->n_addrlen);
 370         if (utmpent && chdir(_PATH_RWHODIR)) {
 371                 syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR);
 372                 exit(1);
 373         }
 374 done:
 375         (void) alarm(AL_INTERVAL);
 376 }
 377
 378 void
 379 getboottime(signo)
 380         int signo;
 381 {
 382         int mib[2];
 383         size_t size;
 384         struct timeval tm;
 385
 386         mib[0] = CTL_KERN;
 387         mib[1] = KERN_BOOTTIME;
 388         size = sizeof(tm);
 389         if (sysctl(mib, 2, &tm, &size, NULL, 0) == -1) {
 390                 syslog(LOG_ERR, "cannot get boottime: %m");
 391                 exit(1);
 392         }
 393         mywd.wd_boottime = htonl(tm.tv_sec);
 394 }
 395
 396 void
 397 quit(msg)
 398         char *msg;
 399 {
 400         syslog(LOG_ERR, msg);
 401         exit(1);
 402 }
 403
 404 #define ROUNDUP(a) \
 405         ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
 406 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
 407
 408 void
 409 rt_xaddrs(cp, cplim, rtinfo)
 410         register caddr_t cp, cplim;
 411         register struct rt_addrinfo *rtinfo;
 412 {
 413         register struct sockaddr *sa;
 414         register int i;
 415
 416         memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info));
 417         for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) {
 418                 if ((rtinfo->rti_addrs & (1 << i)) == 0)
 419                         continue;
 420                 rtinfo->rti_info[i] = sa = (struct sockaddr *)cp;
 421                 ADVANCE(cp, sa);
 422         }
 423 }
 424
 425 /*
 426  * Figure out device configuration and select
 427  * networks which deserve status information.
 428  */
 429 int
 430 configure(s)
 431         int s;
 432 {
 433         register struct neighbor *np;
 434         register struct if_msghdr *ifm;
 435         register struct ifa_msghdr *ifam;
 436         struct sockaddr_dl *sdl;
 437         size_t needed;
 438         int mib[6], flags = 0, len;
 439         char *buf, *lim, *next;
 440         struct rt_addrinfo info;
 441
 442         mib[0] = CTL_NET;
 443         mib[1] = PF_ROUTE;
 444         mib[2] = 0;
 445         mib[3] = AF_INET;
 446         mib[4] = NET_RT_IFLIST;
 447         mib[5] = 0;
 448         if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
 449                 quit("route-sysctl-estimate");
 450         if ((buf = malloc(needed)) == NULL)
 451                 quit("malloc");
 452         if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
 453                 quit("actual retrieval of interface table");
 454         lim = buf + needed;
 455
 456         sdl = NULL;             /* XXX just to keep gcc -Wall happy */
 457         for (next = buf; next < lim; next += ifm->ifm_msglen) {
 458                 ifm = (struct if_msghdr *)next;
 459                 if (ifm->ifm_type == RTM_IFINFO) {
 460                         sdl = (struct sockaddr_dl *)(ifm + 1);
 461                         flags = ifm->ifm_flags;
 462                         continue;
 463                 }
 464                 if ((flags & IFF_UP) == 0 ||
 465                     (flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)
 466                         continue;
 467                 if (ifm->ifm_type != RTM_NEWADDR)
 468                         quit("out of sync parsing NET_RT_IFLIST");
 469                 ifam = (struct ifa_msghdr *)ifm;
 470                 info.rti_addrs = ifam->ifam_addrs;
 471                 rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam,
 472                         &info);
 473                 /* gag, wish we could get rid of Internet dependencies */
 474 #define dstaddr info.rti_info[RTAX_BRD]
 475 #define IPADDR_SA(x) ((struct sockaddr_in *)(x))->sin_addr.s_addr
 476 #define PORT_SA(x) ((struct sockaddr_in *)(x))->sin_port
 477                 if (dstaddr == 0 || dstaddr->sa_family != AF_INET)
 478                         continue;
 479                 PORT_SA(dstaddr) = sp->s_port;
 480                 for (np = neighbors; np != NULL; np = np->n_next)
 481                         if (memcmp(sdl->sdl_data, np->n_name,
 482                                    sdl->sdl_nlen) == 0 &&
 483                             IPADDR_SA(np->n_addr) == IPADDR_SA(dstaddr))
 484                                 break;
 485                 if (np != NULL)
 486                         continue;
 487                 len = sizeof(*np) + dstaddr->sa_len + sdl->sdl_nlen + 1;
 488                 np = (struct neighbor *)malloc(len);
 489                 if (np == NULL)
 490                         quit("malloc of neighbor structure");
 491                 memset(np, 0, len);
 492                 np->n_flags = flags;
 493                 np->n_addr = (struct sockaddr *)(np + 1);
 494                 np->n_addrlen = dstaddr->sa_len;
 495                 np->n_name = np->n_addrlen + (char *)np->n_addr;
 496                 np->n_next = neighbors;
 497                 neighbors = np;
 498                 memcpy((char *)np->n_addr, (char *)dstaddr, np->n_addrlen);
 499                 memcpy(np->n_name, sdl->sdl_data, sdl->sdl_nlen);
 500         }
 501         free(buf);
 502         return (1);
 503 }
 504
 505 #ifdef DEBUG
 506 void
 507 Sendto(s, buf, cc, flags, to, tolen)
 508         int s;
 509         char *buf;
 510         int cc, flags;
 511         char *to;
 512         int tolen;
 513 {
 514         register struct whod *w = (struct whod *)buf;
 515         register struct whoent *we;
 516         struct sockaddr_in *sin = (struct sockaddr_in *)to;
 517
 518         printf("sendto %x.%d\n", ntohl(sin->sin_addr), ntohs(sin->sin_port));
 519         printf("hostname %s %s\n", w->wd_hostname,
 520            interval(ntohl(w->wd_sendtime) - ntohl(w->wd_boottime), "  up"));
 521         printf("load %4.2f, %4.2f, %4.2f\n",
 522             ntohl(w->wd_loadav[0]) / 100.0, ntohl(w->wd_loadav[1]) / 100.0,
 523             ntohl(w->wd_loadav[2]) / 100.0);
 524         cc -= WHDRSIZE;
 525         for (we = w->wd_we, cc /= sizeof(struct whoent); cc > 0; cc--, we++) {
 526                 time_t t = ntohl(we->we_utmp.out_time);
 527                 printf("%-8.8s %s:%s %.12s",
 528                         we->we_utmp.out_name,
 529                         w->wd_hostname, we->we_utmp.out_line,
 530                         ctime(&t)+4);
 531                 we->we_idle = ntohl(we->we_idle) / 60;
 532                 if (we->we_idle) {
 533                         if (we->we_idle >= 100*60)
 534                                 we->we_idle = 100*60 - 1;
 535                         if (we->we_idle >= 60)
 536                                 printf(" %2d", we->we_idle / 60);
 537                         else
 538                                 printf("   ");
 539                         printf(":%02d", we->we_idle % 60);
 540                 }
 541                 printf("\n");
 542         }
 543 }
 544
 545 char *
 546 interval(time, updown)
 547         int time;
 548         char *updown;
 549 {
 550         static char resbuf[32];
 551         int days, hours, minutes;
 552
 553         if (time < 0 || time > 3*30*24*60*60) {
 554                 (void) sprintf(resbuf, "   %s ??:??", updown);
 555                 return (resbuf);
 556         }
 557         minutes = (time + 59) / 60;             /* round to minutes */
 558         hours = minutes / 60; minutes %= 60;
 559         days = hours / 24; hours %= 24;
 560         if (days)
 561                 (void) sprintf(resbuf, "%s %2d+%02d:%02d",
 562                     updown, days, hours, minutes);
 563         else
 564                 (void) sprintf(resbuf, "%s    %2d:%02d",
 565                     updown, hours, minutes);
 566         return (resbuf);
 567 }
 568 #endif