1 /* $OpenBSD: rbootd.c,v 1.22 2005/09/22 14:24:51 jmc Exp $ */ 2 /* $NetBSD: rbootd.c,v 1.5 1995/10/06 05:12:17 thorpej Exp $ */ 3 4 /* 5 * Copyright (c) 1988, 1992 The University of Utah and the Center 6 * for Software Science (CSS). 7 * Copyright (c) 1992, 1993 8 * The Regents of the University of California. All rights reserved. 9 * 10 * This code is derived from software contributed to Berkeley by 11 * the Center for Software Science of the University of Utah Computer 12 * Science Department. CSS requests users of this software to return 13 * to css-dist@cs.utah.edu any improvements that they make and grant 14 * CSS redistribution rights. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 3. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * from: @(#)rbootd.c 8.1 (Berkeley) 6/4/93 41 * 42 * From: Utah Hdr: rbootd.c 3.1 92/07/06 43 * Author: Jeff Forys, University of Utah CSS 44 */ 45 46 #ifndef lint 47 static char copyright[] = 48 "@(#) Copyright (c) 1992, 1993\n\ 49 The Regents of the University of California. All rights reserved.\n"; 50 #endif /* not lint */ 51 52 #ifndef lint 53 /*static char sccsid[] = "@(#)rbootd.c 8.1 (Berkeley) 6/4/93";*/ 54 static char rcsid[] = "$OpenBSD: rbootd.c,v 1.22 2005/09/22 14:24:51 jmc Exp $"; 55 #endif /* not lint */ 56 57 #include <sys/param.h> 58 #include <sys/time.h> 59 60 #include <ctype.h> 61 #include <err.h> 62 #include <errno.h> 63 #include <fcntl.h> 64 #include <signal.h> 65 #include <stdio.h> 66 #include <stdlib.h> 67 #include <string.h> 68 #include <syslog.h> 69 #include <unistd.h> 70 #include <util.h> 71 #include <pwd.h> 72 73 #include "defs.h" 74 75 extern char *__progname; /* from crt0.o */ 76 77 volatile sig_atomic_t dodebugoff; 78 volatile sig_atomic_t dodebugon; 79 volatile sig_atomic_t doreconfig; 80 81 void DebugOff(int); 82 void DebugOn(int); 83 void ReConfig(int); 84 void Exit(int); 85 86 void DoDebugOff(void); 87 void DoDebugOn(void); 88 void DoReConfig(void); 89 90 void DoTimeout(void); 91 CLIENT *FindClient(RMPCONN *); 92 93 int 94 main(int argc, char *argv[]) 95 { 96 int c, fd, maxfds; 97 sigset_t hmask, omask; 98 struct passwd *pw; 99 fd_set rset; 100 101 closefrom(STDERR_FILENO + 1); 102 103 if ((pw = getpwnam("_rbootd")) == NULL) 104 err(1, "getpwnam"); 105 106 while ((c = getopt(argc, argv, "adi:")) != -1) 107 switch (c) { 108 case 'a': 109 BootAny++; 110 break; 111 case 'd': 112 DebugFlg++; 113 break; 114 case 'i': 115 IntfName = optarg; 116 break; 117 } 118 for (; optind < argc; optind++) { 119 if (ConfigFile == NULL) 120 ConfigFile = argv[optind]; 121 else { 122 warnx("too many config files (`%s' ignored)", 123 argv[optind]); 124 } 125 } 126 127 if (ConfigFile == NULL) /* use default config file */ 128 ConfigFile = DfltConfig; 129 130 if (DebugFlg) { 131 DbgFp = stdout; /* output to stdout */ 132 133 (void) signal(SIGUSR1, SIG_IGN); /* dont muck w/DbgFp */ 134 (void) signal(SIGUSR2, SIG_IGN); 135 (void) fclose(stderr); /* finished with it */ 136 } else { 137 if (daemon(0, 0)) 138 err(1, "can't detach from terminal"); 139 140 (void) signal(SIGUSR1, DebugOn); 141 (void) signal(SIGUSR2, DebugOff); 142 } 143 144 /* 145 * If no interface was specified, get one now. 146 * 147 * This is convoluted because we want to get the default interface 148 * name for the syslog("restarted") message. If BpfGetIntfName() 149 * runs into an error, it will return a syslog-able error message 150 * (in `errmsg') which will be displayed here. 151 */ 152 if (IntfName == NULL) { 153 char *errmsg; 154 155 if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) { 156 syslog(LOG_NOTICE, "restarted (??)"); 157 /* BpfGetIntfName() returns safe names, using %m */ 158 syslog(LOG_ERR, "%s", errmsg); 159 DoExit(); 160 } 161 } 162 163 openlog(__progname, LOG_PID, LOG_DAEMON); 164 fd = BpfOpen(); 165 syslog(LOG_NOTICE, "restarted (%s)", IntfName); 166 167 (void) signal(SIGHUP, ReConfig); 168 (void) signal(SIGINT, Exit); 169 (void) signal(SIGTERM, Exit); 170 171 gethostname(MyHost, MAXHOSTNAMELEN); 172 173 if (pidfile(NULL) < 0) 174 syslog(LOG_WARNING, "pidfile: failed"); 175 176 /* 177 * All boot files are relative to the boot directory, we might 178 * as well chdir() there to make life easier. 179 */ 180 if (chdir(BootDir) < 0) { 181 syslog(LOG_ERR, "chdir: %m (%s)", BootDir); 182 DoExit(); 183 } 184 185 /* 186 * Initial configuration. 187 */ 188 sigemptyset(&hmask); 189 sigaddset(&hmask, SIGHUP); 190 sigprocmask(SIG_BLOCK, &hmask, &omask); /* prevent reconfig's */ 191 if (GetBootFiles() == 0) /* get list of boot files */ 192 DoExit(); 193 if (ParseConfig() == 0) /* parse config file */ 194 DoExit(); 195 196 if (chroot(BootDir) == -1) { 197 syslog(LOG_CRIT, "chroot %s: %m", BootDir); 198 exit(1); 199 } 200 if (chdir("/") == -1) { 201 syslog(LOG_CRIT, "chdir(\"/\"): %m"); 202 exit(1); 203 } 204 if (setgroups(1, &pw->pw_gid) || 205 setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) || 206 setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid)) { 207 syslog(LOG_CRIT, "can't drop privileges: %m"); 208 exit(1); 209 } 210 endpwent(); 211 212 sigprocmask(SIG_SETMASK, &omask, NULL); /* allow reconfig's */ 213 214 /* 215 * Main loop: receive a packet, determine where it came from, 216 * and if we service this host, call routine to handle request. 217 */ 218 maxfds = fd + 1; 219 FD_ZERO(&rset); 220 FD_SET(fd, &rset); 221 for (;;) { 222 struct timeval timeout; 223 fd_set r; 224 int nsel; 225 226 /* 227 * Check pending actions 228 */ 229 if (dodebugoff) { 230 DoDebugOff(); 231 dodebugoff = 0; 232 } 233 if (dodebugon) { 234 DoDebugOn(); 235 dodebugon = 0; 236 } 237 if (doreconfig) { 238 DoReConfig(); 239 doreconfig = 0; 240 } 241 242 r = rset; 243 244 if (RmpConns == NULL) { /* timeout isnt necessary */ 245 nsel = select(maxfds, &r, NULL, NULL, NULL); 246 } else { 247 timeout.tv_sec = RMP_TIMEOUT; 248 timeout.tv_usec = 0; 249 nsel = select(maxfds, &r, NULL, NULL, &timeout); 250 } 251 252 if (nsel < 0) { 253 if (errno == EINTR) 254 continue; 255 syslog(LOG_ERR, "select: %m"); 256 DoExit(); 257 } else if (nsel == 0) { /* timeout */ 258 DoTimeout(); /* clear stale conns */ 259 continue; 260 } 261 262 if (FD_ISSET(fd, &r)) { 263 RMPCONN rconn; 264 CLIENT *client; 265 int doread = 1; 266 267 while (BpfRead(&rconn, doread)) { 268 doread = 0; 269 270 if (DbgFp != NULL) /* display packet */ 271 DispPkt(&rconn,DIR_RCVD); 272 273 sigprocmask(SIG_BLOCK, &hmask, &omask); 274 275 /* 276 * If we do not restrict service, set the 277 * client to NULL (ProcessPacket() handles 278 * this). Otherwise, check that we can 279 * service this host; if not, log a message 280 * and ignore the packet. 281 */ 282 if (BootAny) { 283 client = NULL; 284 } else if ((client=FindClient(&rconn))==NULL) { 285 syslog(LOG_INFO, 286 "%s: boot packet ignored", 287 EnetStr(&rconn)); 288 sigprocmask(SIG_SETMASK, &omask, NULL); 289 continue; 290 } 291 292 ProcessPacket(&rconn,client); 293 294 sigprocmask(SIG_SETMASK, &omask, NULL); 295 } 296 } 297 } 298 } 299 300 /* 301 ** DoTimeout -- Free any connections that have timed out. 302 ** 303 ** Parameters: 304 ** None. 305 ** 306 ** Returns: 307 ** Nothing. 308 ** 309 ** Side Effects: 310 ** - Timed out connections in `RmpConns' will be freed. 311 */ 312 void 313 DoTimeout(void) 314 { 315 RMPCONN *rtmp; 316 struct timeval now; 317 318 (void) gettimeofday(&now, (struct timezone *)0); 319 320 /* 321 * For each active connection, if RMP_TIMEOUT seconds have passed 322 * since the last packet was sent, delete the connection. 323 */ 324 for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next) 325 if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) { 326 syslog(LOG_WARNING, "%s: connection timed out (%u)", 327 EnetStr(rtmp), rtmp->rmp.r_type); 328 RemoveConn(rtmp); 329 } 330 } 331 332 /* 333 ** FindClient -- Find client associated with a packet. 334 ** 335 ** Parameters: 336 ** rconn - the new packet. 337 ** 338 ** Returns: 339 ** Pointer to client info if found, NULL otherwise. 340 ** 341 ** Side Effects: 342 ** None. 343 ** 344 ** Warnings: 345 ** - This routine must be called with SIGHUP blocked since 346 ** a reconfigure can invalidate the information returned. 347 */ 348 CLIENT * 349 FindClient(RMPCONN *rconn) 350 { 351 CLIENT *ctmp; 352 353 for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next) 354 if (bcmp((char *)&rconn->rmp.hp_hdr.saddr[0], 355 (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0) 356 break; 357 358 return(ctmp); 359 } 360 361 /* 362 ** Exit -- Log an error message and exit. 363 ** 364 ** Parameters: 365 ** sig - caught signal (or zero if not dying on a signal). 366 ** 367 ** Returns: 368 ** Does not return. 369 ** 370 ** Side Effects: 371 ** - This process ceases to exist. 372 */ 373 void 374 Exit(int sig) 375 { 376 struct syslog_data sdata = SYSLOG_DATA_INIT; 377 378 syslog_r(LOG_ERR, &sdata, "going down on signal %d", sig); 379 _exit(1); 380 } 381 382 void 383 DoExit(void) 384 { 385 syslog(LOG_ERR, "going down on fatal error"); 386 exit(1); 387 } 388 389 /* 390 ** ReConfig -- Get new list of boot files and reread config files. 391 ** 392 ** Parameters: 393 ** None. 394 ** 395 ** Returns: 396 ** Nothing. 397 ** 398 ** Side Effects: 399 ** - All active connections are dropped. 400 ** - List of bootable files is changed. 401 ** - List of clients is changed. 402 ** 403 ** Warnings: 404 ** - This routine must be called with SIGHUP blocked. 405 */ 406 void 407 ReConfig(int signo) 408 { 409 doreconfig = 1; 410 } 411 412 void 413 DoReConfig(void) 414 { 415 syslog(LOG_NOTICE, "reconfiguring boot server"); 416 417 FreeConns(); 418 419 if (GetBootFiles() == 0) 420 DoExit(); 421 422 if (ParseConfig() == 0) 423 DoExit(); 424 } 425 426 /* 427 ** DebugOff -- Turn off debugging. 428 ** 429 ** Parameters: 430 ** None. 431 ** 432 ** Returns: 433 ** Nothing. 434 ** 435 ** Side Effects: 436 ** - Debug file is closed. 437 */ 438 void 439 DebugOff(int signo) 440 { 441 dodebugoff = 1; 442 } 443 444 void 445 DoDebugOff(void) 446 { 447 if (DbgFp != NULL) 448 (void) fclose(DbgFp); 449 450 DbgFp = NULL; 451 } 452 453 /* 454 ** DebugOn -- Turn on debugging. 455 ** 456 ** Parameters: 457 ** None. 458 ** 459 ** Returns: 460 ** Nothing. 461 ** 462 ** Side Effects: 463 ** - Debug file is opened/truncated if not already opened, 464 ** otherwise do nothing. 465 */ 466 void 467 DebugOn(int signo) 468 { 469 dodebugon = 1; 470 } 471 472 void 473 DoDebugOn(void) 474 { 475 if (DbgFp == NULL) { 476 if ((DbgFp = fopen(DbgFile, "w")) == NULL) 477 syslog(LOG_ERR, "can't open debug file (%s)", DbgFile); 478 } 479 } 480