usr.sbin/rbootd/rbootd.c

   1 /*      $NetBSD: rbootd.c,v 1.20 2007/02/21 20:57:55 hubertf Exp $      */
   2
   3 /*
   4  * Copyright (c) 1992, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * the Center for Software Science of the University of Utah Computer
   9  * Science Department.  CSS requests users of this software to return
  10  * to css-dist@cs.utah.edu any improvements that they make and grant
  11  * CSS redistribution rights.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 3. Neither the name of the University nor the names of its contributors
  22  *    may be used to endorse or promote products derived from this software
  23  *    without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  35  * SUCH DAMAGE.
  36  *
  37  *      from: @(#)rbootd.c      8.1 (Berkeley) 6/4/93
  38  *
  39  * From: Utah Hdr: rbootd.c 3.1 92/07/06
  40  * Author: Jeff Forys, University of Utah CSS
  41  */
  42
  43 /*
  44  * Copyright (c) 1988, 1992 The University of Utah and the Center
  45  *      for Software Science (CSS).
  46  *
  47  * This code is derived from software contributed to Berkeley by
  48  * the Center for Software Science of the University of Utah Computer
  49  * Science Department.  CSS requests users of this software to return
  50  * to css-dist@cs.utah.edu any improvements that they make and grant
  51  * CSS redistribution rights.
  52  *
  53  * Redistribution and use in source and binary forms, with or without
  54  * modification, are permitted provided that the following conditions
  55  * are met:
  56  * 1. Redistributions of source code must retain the above copyright
  57  *    notice, this list of conditions and the following disclaimer.
  58  * 2. Redistributions in binary form must reproduce the above copyright
  59  *    notice, this list of conditions and the following disclaimer in the
  60  *    documentation and/or other materials provided with the distribution.
  61  * 3. All advertising materials mentioning features or use of this software
  62  *    must display the following acknowledgement:
  63  *      This product includes software developed by the University of
  64  *      California, Berkeley and its contributors.
  65  * 4. Neither the name of the University nor the names of its contributors
  66  *    may be used to endorse or promote products derived from this software
  67  *    without specific prior written permission.
  68  *
  69  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  70  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  71  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  72  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  73  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  74  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  75  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  76  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  77  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  78  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  79  * SUCH DAMAGE.
  80  *
  81  *      from: @(#)rbootd.c      8.1 (Berkeley) 6/4/93
  82  *
  83  * From: Utah Hdr: rbootd.c 3.1 92/07/06
  84  * Author: Jeff Forys, University of Utah CSS
  85  */
  86
  87 #include <sys/cdefs.h>
  88 #ifndef lint
  89 __COPYRIGHT("@(#) Copyright (c) 1992, 1993\
  90  The Regents of the University of California.  All rights reserved.");
  91 #endif /* not lint */
  92
  93 #ifndef lint
  94 #if 0
  95 static char sccsid[] = "@(#)rbootd.c    8.1 (Berkeley) 6/4/93";
  96 #else
  97 __RCSID("$NetBSD: rbootd.c,v 1.20 2007/02/21 20:57:55 hubertf Exp $");
  98 #endif
  99 #endif /* not lint */
 100
 101 #include <sys/param.h>
 102 #include <sys/time.h>
 103 #include <poll.h>
 104 #include <err.h>
 105 #include <errno.h>
 106 #include <fcntl.h>
 107 #include <signal.h>
 108 #include <stdio.h>
 109 #include <stdlib.h>
 110 #include <string.h>
 111 #include <syslog.h>
 112 #include <unistd.h>
 113 #include <util.h>
 114 #include "defs.h"
 115
 116 int     main (int, char *[]);
 117
 118 int
 119 main(int argc, char *argv[])
 120 {
 121         int c, fd, omask;
 122         struct pollfd set[1];
 123
 124         /*
 125          *  Close any open file descriptors.
 126          *  Temporarily leave stdin & stdout open for `-d',
 127          *  and stderr open for any pre-syslog error messages.
 128          */
 129         {
 130                 int i, nfds = getdtablesize();
 131
 132                 for (i = 0; i < nfds; i++)
 133                         if (i != STDIN_FILENO && i != STDOUT_FILENO &&
 134                             i != STDERR_FILENO)
 135                                 (void) close(i);
 136         }
 137
 138         /*
 139          *  Parse any arguments.
 140          */
 141         while ((c = getopt(argc, argv, "adi:")) != -1)
 142                 switch(c) {
 143                     case 'a':
 144                         BootAny++;
 145                         break;
 146                     case 'd':
 147                         DebugFlg++;
 148                         break;
 149                     case 'i':
 150                         IntfName = optarg;
 151                         break;
 152                 }
 153         for (; optind < argc; optind++) {
 154                 if (ConfigFile == NULL)
 155                         ConfigFile = argv[optind];
 156                 else {
 157                         warnx("too many config files (`%s' ignored)",
 158                             argv[optind]);
 159                 }
 160         }
 161
 162         if (ConfigFile == NULL)                 /* use default config file */
 163                 ConfigFile = DfltConfig;
 164
 165         if (DebugFlg) {
 166                 DbgFp = stdout;                         /* output to stdout */
 167
 168                 (void) signal(SIGUSR1, SIG_IGN);        /* dont muck w/DbgFp */
 169                 (void) signal(SIGUSR2, SIG_IGN);
 170                 (void) fclose(stderr);                  /* finished with it */
 171         } else {
 172                 if (daemon(0, 0))
 173                         err(1, "can't detach from terminal");
 174                 pidfile(NULL);
 175
 176                 (void) signal(SIGUSR1, DebugOn);
 177                 (void) signal(SIGUSR2, DebugOff);
 178         }
 179
 180         openlog("rbootd", LOG_PID, LOG_DAEMON);
 181
 182         /*
 183          *  If no interface was specified, get one now.
 184          *
 185          *  This is convoluted because we want to get the default interface
 186          *  name for the syslog("restarted") message.  If BpfGetIntfName()
 187          *  runs into an error, it will return a syslog-able error message
 188          *  (in `errmsg') which will be displayed here.
 189          */
 190         if (IntfName == NULL) {
 191                 char *errmsg;
 192
 193                 if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
 194                         /* backslash to avoid trigraph ??) */
 195                         syslog(LOG_NOTICE, "restarted (?\?)");
 196                         syslog(LOG_ERR, errmsg);
 197                         Exit(0);
 198                 }
 199         }
 200
 201         syslog(LOG_NOTICE, "restarted (%s)", IntfName);
 202
 203         (void) signal(SIGHUP, ReConfig);
 204         (void) signal(SIGINT, Exit);
 205         (void) signal(SIGTERM, Exit);
 206
 207         /*
 208          *  Grab our host name and pid.
 209          */
 210         if (gethostname(MyHost, sizeof MyHost) < 0) {
 211                 syslog(LOG_ERR, "gethostname: %m");
 212                 Exit(0);
 213         }
 214         MyHost[sizeof(MyHost) - 1] = '\0';
 215
 216         /*
 217          *  All boot files are relative to the boot directory, we might
 218          *  as well chdir() there to make life easier.
 219          */
 220         if (chdir(BootDir) < 0) {
 221                 syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
 222                 Exit(0);
 223         }
 224
 225         /*
 226          *  Initial configuration.
 227          */
 228         omask = sigblock(sigmask(SIGHUP));      /* prevent reconfig's */
 229         if (GetBootFiles() == 0)                /* get list of boot files */
 230                 Exit(0);
 231         if (ParseConfig() == 0)                 /* parse config file */
 232                 Exit(0);
 233
 234         /*
 235          *  Open and initialize a BPF device for the appropriate interface.
 236          *  If an error is encountered, a message is displayed and Exit()
 237          *  is called.
 238          */
 239         fd = BpfOpen();
 240
 241         (void) sigsetmask(omask);               /* allow reconfig's */
 242
 243         /*
 244          *  Main loop: receive a packet, determine where it came from,
 245          *  and if we service this host, call routine to handle request.
 246          */
 247         set[0].fd = fd;
 248         set[0].events = POLLIN;
 249         for (;;) {
 250                 int nsel;
 251
 252                 nsel = poll(set, 1, RmpConns ? RMP_TIMEOUT * 1000 : INFTIM);
 253
 254                 if (nsel < 0) {
 255                         if (errno == EINTR)
 256                                 continue;
 257                         syslog(LOG_ERR, "poll: %m");
 258                         Exit(0);
 259                 } else if (nsel == 0) {         /* timeout */
 260                         DoTimeout();                    /* clear stale conns */
 261                         continue;
 262                 }
 263
 264                 if (set[0].revents & POLLIN) {
 265                         RMPCONN rconn;
 266                         CLIENT *client;
 267                         int doread = 1;
 268
 269                         while (BpfRead(&rconn, doread)) {
 270                                 doread = 0;
 271
 272                                 if (DbgFp != NULL)      /* display packet */
 273                                         DispPkt(&rconn,DIR_RCVD);
 274
 275                                 omask = sigblock(sigmask(SIGHUP));
 276
 277                                 /*
 278                                  *  If we do not restrict service, set the
 279                                  *  client to NULL (ProcessPacket() handles
 280                                  *  this).  Otherwise, check that we can
 281                                  *  service this host; if not, log a message
 282                                  *  and ignore the packet.
 283                                  */
 284                                 if (BootAny) {
 285                                         client = NULL;
 286                                 } else if ((client=FindClient(&rconn))==NULL) {
 287                                         syslog(LOG_INFO,
 288                                                "%s: boot packet ignored",
 289                                                EnetStr(&rconn));
 290                                         (void) sigsetmask(omask);
 291                                         continue;
 292                                 }
 293
 294                                 ProcessPacket(&rconn,client);
 295
 296                                 (void) sigsetmask(omask);
 297                         }
 298                 }
 299         }
 300 }
 301
 302 /*
 303 **  DoTimeout -- Free any connections that have timed out.
 304 **
 305 **      Parameters:
 306 **              None.
 307 **
 308 **      Returns:
 309 **              Nothing.
 310 **
 311 **      Side Effects:
 312 **              - Timed out connections in `RmpConns' will be freed.
 313 */
 314 void
 315 DoTimeout(void)
 316 {
 317         RMPCONN *rtmp;
 318         struct timeval now;
 319
 320         (void) gettimeofday(&now, (struct timezone *)0);
 321
 322         /*
 323          *  For each active connection, if RMP_TIMEOUT seconds have passed
 324          *  since the last packet was sent, delete the connection.
 325          */
 326         for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
 327                 if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
 328                         syslog(LOG_WARNING, "%s: connection timed out (%u)",
 329                                EnetStr(rtmp), rtmp->rmp.r_type);
 330                         RemoveConn(rtmp);
 331                 }
 332 }
 333
 334 /*
 335 **  FindClient -- Find client associated with a packet.
 336 **
 337 **      Parameters:
 338 **              rconn - the new packet.
 339 **
 340 **      Returns:
 341 **              Pointer to client info if found, NULL otherwise.
 342 **
 343 **      Side Effects:
 344 **              None.
 345 **
 346 **      Warnings:
 347 **              - This routine must be called with SIGHUP blocked since
 348 **                a reconfigure can invalidate the information returned.
 349 */
 350
 351 CLIENT *
 352 FindClient(RMPCONN *rconn)
 353 {
 354         CLIENT *ctmp;
 355
 356         for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
 357                 if (memcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
 358                          (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
 359                         break;
 360
 361         return(ctmp);
 362 }
 363
 364 /*
 365 **  Exit -- Log an error message and exit.
 366 **
 367 **      Parameters:
 368 **              sig - caught signal (or zero if not dying on a signal).
 369 **
 370 **      Returns:
 371 **              Does not return.
 372 **
 373 **      Side Effects:
 374 **              - This process ceases to exist.
 375 */
 376 void
 377 Exit(int sig)
 378 {
 379         if (sig > 0)
 380                 syslog(LOG_ERR, "going down on signal %d", sig);
 381         else
 382                 syslog(LOG_ERR, "going down with fatal error");
 383         BpfClose();
 384         exit(1);
 385 }
 386
 387 /*
 388 **  ReConfig -- Get new list of boot files and reread config files.
 389 **
 390 **      Parameters:
 391 **              None.
 392 **
 393 **      Returns:
 394 **              Nothing.
 395 **
 396 **      Side Effects:
 397 **              - All active connections are dropped.
 398 **              - List of boot-able files is changed.
 399 **              - List of clients is changed.
 400 **
 401 **      Warnings:
 402 **              - This routine must be called with SIGHUP blocked.
 403 */
 404 void
 405 ReConfig(int signo)
 406 {
 407         syslog(LOG_NOTICE, "reconfiguring boot server");
 408
 409         FreeConns();
 410
 411         if (GetBootFiles() == 0)
 412                 Exit(0);
 413
 414         if (ParseConfig() == 0)
 415                 Exit(0);
 416 }
 417
 418 /*
 419 **  DebugOff -- Turn off debugging.
 420 **
 421 **      Parameters:
 422 **              None.
 423 **
 424 **      Returns:
 425 **              Nothing.
 426 **
 427 **      Side Effects:
 428 **              - Debug file is closed.
 429 */
 430 void
 431 DebugOff(int signo)
 432 {
 433         if (DbgFp != NULL)
 434                 (void) fclose(DbgFp);
 435
 436         DbgFp = NULL;
 437 }
 438
 439 /*
 440 **  DebugOn -- Turn on debugging.
 441 **
 442 **      Parameters:
 443 **              None.
 444 **
 445 **      Returns:
 446 **              Nothing.
 447 **
 448 **      Side Effects:
 449 **              - Debug file is opened/truncated if not already opened,
 450 **                otherwise do nothing.
 451 */
 452 void
 453 DebugOn(int signo)
 454 {
 455         if (DbgFp == NULL) {
 456                 if ((DbgFp = fopen(DbgFile, "w")) == NULL)
 457                         syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
 458         }
 459 }