libexec/rbootd/rbootd.c

   1 /*
   2  * Copyright (c) 1988, 1992 The University of Utah and the Center
   3  *      for Software Science (CSS).
   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  * @(#) Copyright (c) 1992, 1993 The Regents of the University of California.  All rights reserved.
  43  * @(#)rbootd.c 8.1 (Berkeley) 6/4/93
  44  * $FreeBSD: src/libexec/rbootd/rbootd.c,v 1.11.2.1 2001/02/18 02:54:11 kris Exp $
  45  */
  46
  47 #include <sys/param.h>
  48 #include <sys/time.h>
  49 #include <ctype.h>
  50 #include <err.h>
  51 #include <errno.h>
  52 #include <fcntl.h>
  53 #include <signal.h>
  54 #include <stdio.h>
  55 #include <stdlib.h>
  56 #include <string.h>
  57 #include <syslog.h>
  58 #include <unistd.h>
  59 #include "defs.h"
  60
  61 static void usage (void);
  62
  63 int
  64 main(int argc, char *argv[])
  65 {
  66         int c, fd, omask, maxfds;
  67         fd_set rset;
  68
  69         /*
  70          *  Close any open file descriptors.
  71          *  Temporarily leave stdin & stdout open for `-d',
  72          *  and stderr open for any pre-syslog error messages.
  73          */
  74         {
  75                 int i, nfds = getdtablesize();
  76
  77                 for (i = 0; i < nfds; i++)
  78                         if (i != fileno(stdin) && i != fileno(stdout) &&
  79                             i != fileno(stderr))
  80                                 (void) close(i);
  81         }
  82
  83         /*
  84          *  Parse any arguments.
  85          */
  86         while ((c = getopt(argc, argv, "adi:")) != -1)
  87                 switch(c) {
  88                     case 'a':
  89                         BootAny++;
  90                         break;
  91                     case 'd':
  92                         DebugFlg++;
  93                         break;
  94                     case 'i':
  95                         IntfName = optarg;
  96                         break;
  97                     default:
  98                         usage();
  99                 }
 100         for (; optind < argc; optind++) {
 101                 if (ConfigFile == NULL)
 102                         ConfigFile = argv[optind];
 103                 else {
 104                         warnx("too many config files (`%s' ignored)",
 105                             argv[optind]);
 106                 }
 107         }
 108
 109         if (ConfigFile == NULL)                 /* use default config file */
 110                 ConfigFile = DfltConfig;
 111
 112         if (DebugFlg) {
 113                 DbgFp = stdout;                         /* output to stdout */
 114
 115                 (void) signal(SIGUSR1, SIG_IGN);        /* dont muck w/DbgFp */
 116                 (void) signal(SIGUSR2, SIG_IGN);
 117                 (void) fclose(stderr);                  /* finished with it */
 118         } else {
 119                 if (daemon(0, 0))
 120                         err(1, "can't detach from terminal");
 121
 122                 (void) signal(SIGUSR1, DebugOn);
 123                 (void) signal(SIGUSR2, DebugOff);
 124         }
 125
 126         openlog("rbootd", LOG_PID, LOG_DAEMON);
 127
 128         /*
 129          *  If no interface was specified, get one now.
 130          *
 131          *  This is convoluted because we want to get the default interface
 132          *  name for the syslog("restarted") message.  If BpfGetIntfName()
 133          *  runs into an error, it will return a syslog-able error message
 134          *  (in `errmsg') which will be displayed here.
 135          */
 136         if (IntfName == NULL) {
 137                 char *errmsg;
 138
 139                 if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
 140                         syslog(LOG_NOTICE, "restarted (?\?)");
 141                         /* BpfGetIntfName() returns safe names, using %m */
 142                         syslog(LOG_ERR, "%s", errmsg);
 143                         Exit(0);
 144                 }
 145         }
 146
 147         syslog(LOG_NOTICE, "restarted (%s)", IntfName);
 148
 149         (void) signal(SIGHUP, ReConfig);
 150         (void) signal(SIGINT, Exit);
 151         (void) signal(SIGTERM, Exit);
 152
 153         /*
 154          *  Grab our host name and pid.
 155          */
 156         if (gethostname(MyHost, MAXHOSTNAMELEN - 1) < 0) {
 157                 syslog(LOG_ERR, "gethostname: %m");
 158                 Exit(0);
 159         }
 160         MyHost[MAXHOSTNAMELEN - 1] = '\0';
 161
 162         MyPid = getpid();
 163
 164         /*
 165          *  Write proc's pid to a file.
 166          */
 167         {
 168                 FILE *fp;
 169
 170                 if ((fp = fopen(PidFile, "w")) != NULL) {
 171                         (void) fprintf(fp, "%d\n", (int) MyPid);
 172                         (void) fclose(fp);
 173                 } else {
 174                         syslog(LOG_WARNING, "fopen: failed (%s)", PidFile);
 175                 }
 176         }
 177
 178         /*
 179          *  All boot files are relative to the boot directory, we might
 180          *  as well chdir() there to make life easier.
 181          */
 182         if (chdir(BootDir) < 0) {
 183                 syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
 184                 Exit(0);
 185         }
 186
 187         /*
 188          *  Initial configuration.
 189          */
 190         omask = sigblock(sigmask(SIGHUP));      /* prevent reconfig's */
 191         if (GetBootFiles() == 0)                /* get list of boot files */
 192                 Exit(0);
 193         if (ParseConfig() == 0)                 /* parse config file */
 194                 Exit(0);
 195
 196         /*
 197          *  Open and initialize a BPF device for the appropriate interface.
 198          *  If an error is encountered, a message is displayed and Exit()
 199          *  is called.
 200          */
 201         fd = BpfOpen();
 202
 203         (void) sigsetmask(omask);               /* allow reconfig's */
 204
 205         /*
 206          *  Main loop: receive a packet, determine where it came from,
 207          *  and if we service this host, call routine to handle request.
 208          */
 209         maxfds = fd + 1;
 210         FD_ZERO(&rset);
 211         FD_SET(fd, &rset);
 212         for (;;) {
 213                 struct timeval timeout;
 214                 fd_set r;
 215                 int nsel;
 216
 217                 r = rset;
 218
 219                 if (RmpConns == NULL) {         /* timeout isnt necessary */
 220                         nsel = select(maxfds, &r, NULL, NULL, NULL);
 221                 } else {
 222                         timeout.tv_sec = RMP_TIMEOUT;
 223                         timeout.tv_usec = 0;
 224                         nsel = select(maxfds, &r, NULL, NULL, &timeout);
 225                 }
 226
 227                 if (nsel < 0) {
 228                         if (errno == EINTR)
 229                                 continue;
 230                         syslog(LOG_ERR, "select: %m");
 231                         Exit(0);
 232                 } else if (nsel == 0) {         /* timeout */
 233                         DoTimeout();                    /* clear stale conns */
 234                         continue;
 235                 }
 236
 237                 if (FD_ISSET(fd, &r)) {
 238                         RMPCONN rconn;
 239                         CLIENT *client, *FindClient();
 240                         int doread = 1;
 241
 242                         while (BpfRead(&rconn, doread)) {
 243                                 doread = 0;
 244
 245                                 if (DbgFp != NULL)      /* display packet */
 246                                         DispPkt(&rconn,DIR_RCVD);
 247
 248                                 omask = sigblock(sigmask(SIGHUP));
 249
 250                                 /*
 251                                  *  If we do not restrict service, set the
 252                                  *  client to NULL (ProcessPacket() handles
 253                                  *  this).  Otherwise, check that we can
 254                                  *  service this host; if not, log a message
 255                                  *  and ignore the packet.
 256                                  */
 257                                 if (BootAny) {
 258                                         client = NULL;
 259                                 } else if ((client=FindClient(&rconn))==NULL) {
 260                                         syslog(LOG_INFO,
 261                                                "%s: boot packet ignored",
 262                                                EnetStr(&rconn));
 263                                         (void) sigsetmask(omask);
 264                                         continue;
 265                                 }
 266
 267                                 ProcessPacket(&rconn,client);
 268
 269                                 (void) sigsetmask(omask);
 270                         }
 271                 }
 272         }
 273 }
 274
 275 static void
 276 usage(void)
 277 {
 278         fprintf(stderr, "usage: rbootd [-ad] [-i interface] [config_file]\n");
 279         exit (1);
 280 }
 281
 282 /*
 283 **  DoTimeout -- Free any connections that have timed out.
 284 **
 285 **      Parameters:
 286 **              None.
 287 **
 288 **      Returns:
 289 **              Nothing.
 290 **
 291 **      Side Effects:
 292 **              - Timed out connections in `RmpConns' will be freed.
 293 */
 294 void
 295 DoTimeout(void)
 296 {
 297         RMPCONN *rtmp;
 298         struct timeval now;
 299
 300         (void) gettimeofday(&now, NULL);
 301
 302         /*
 303          *  For each active connection, if RMP_TIMEOUT seconds have passed
 304          *  since the last packet was sent, delete the connection.
 305          */
 306         for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
 307                 if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
 308                         syslog(LOG_WARNING, "%s: connection timed out (%u)",
 309                                EnetStr(rtmp), rtmp->rmp.r_type);
 310                         RemoveConn(rtmp);
 311                 }
 312 }
 313
 314 /*
 315 **  FindClient -- Find client associated with a packet.
 316 **
 317 **      Parameters:
 318 **              rconn - the new packet.
 319 **
 320 **      Returns:
 321 **              Pointer to client info if found, NULL otherwise.
 322 **
 323 **      Side Effects:
 324 **              None.
 325 **
 326 **      Warnings:
 327 **              - This routine must be called with SIGHUP blocked since
 328 **                a reconfigure can invalidate the information returned.
 329 */
 330
 331 CLIENT *
 332 FindClient(RMPCONN *rconn)
 333 {
 334         CLIENT *ctmp;
 335
 336         for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
 337                 if (bcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
 338                          (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
 339                         break;
 340
 341         return(ctmp);
 342 }
 343
 344 /*
 345 **  Exit -- Log an error message and exit.
 346 **
 347 **      Parameters:
 348 **              sig - caught signal (or zero if not dying on a signal).
 349 **
 350 **      Returns:
 351 **              Does not return.
 352 **
 353 **      Side Effects:
 354 **              - This process ceases to exist.
 355 */
 356 void
 357 Exit(int sig)
 358 {
 359         if (sig > 0)
 360                 syslog(LOG_ERR, "going down on signal %d", sig);
 361         else
 362                 syslog(LOG_ERR, "going down with fatal error");
 363         BpfClose();
 364         exit(1);
 365 }
 366
 367 /*
 368 **  ReConfig -- Get new list of boot files and reread config files.
 369 **
 370 **      Parameters:
 371 **              None.
 372 **
 373 **      Returns:
 374 **              Nothing.
 375 **
 376 **      Side Effects:
 377 **              - All active connections are dropped.
 378 **              - List of boot-able files is changed.
 379 **              - List of clients is changed.
 380 **
 381 **      Warnings:
 382 **              - This routine must be called with SIGHUP blocked.
 383 */
 384 void
 385 ReConfig(int signo)
 386 {
 387         syslog(LOG_NOTICE, "reconfiguring boot server");
 388
 389         FreeConns();
 390
 391         if (GetBootFiles() == 0)
 392                 Exit(0);
 393
 394         if (ParseConfig() == 0)
 395                 Exit(0);
 396 }
 397
 398 /*
 399 **  DebugOff -- Turn off debugging.
 400 **
 401 **      Parameters:
 402 **              None.
 403 **
 404 **      Returns:
 405 **              Nothing.
 406 **
 407 **      Side Effects:
 408 **              - Debug file is closed.
 409 */
 410 void
 411 DebugOff(int signo)
 412 {
 413         if (DbgFp != NULL)
 414                 (void) fclose(DbgFp);
 415
 416         DbgFp = NULL;
 417 }
 418
 419 /*
 420 **  DebugOn -- Turn on debugging.
 421 **
 422 **      Parameters:
 423 **              None.
 424 **
 425 **      Returns:
 426 **              Nothing.
 427 **
 428 **      Side Effects:
 429 **              - Debug file is opened/truncated if not already opened,
 430 **                otherwise do nothing.
 431 */
 432 void
 433 DebugOn(int signo)
 434 {
 435         if (DbgFp == NULL) {
 436                 if ((DbgFp = fopen(DbgFile, "w")) == NULL)
 437                         syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
 438         }
 439 }