1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1988, 1992 The University of Utah and the Center 5 * for Software Science (CSS). 6 * Copyright (c) 1992, 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * the Center for Software Science of the University of Utah Computer 11 * Science Department. CSS requests users of this software to return 12 * to css-dist@cs.utah.edu any improvements that they make and grant 13 * CSS redistribution rights. 14 * 15 * Redistribution and use in source and binary forms, with or without 16 * modification, are permitted provided that the following conditions 17 * are met: 18 * 1. Redistributions of source code must retain the above copyright 19 * notice, this list of conditions and the following disclaimer. 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in the 22 * documentation and/or other materials provided with the distribution. 23 * 3. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * From: Utah Hdr: rbootd.c 3.1 92/07/06 40 * Author: Jeff Forys, University of Utah CSS 41 */ 42 43 #include <sys/param.h> 44 #include <sys/time.h> 45 #include <ctype.h> 46 #include <err.h> 47 #include <errno.h> 48 #include <fcntl.h> 49 #include <signal.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <syslog.h> 54 #include <unistd.h> 55 #include "defs.h" 56 57 static void usage(void) __dead2; 58 59 int 60 main(int argc, char *argv[]) 61 { 62 int c, fd, omask, maxfds; 63 fd_set rset; 64 65 /* 66 * Close any open file descriptors. 67 * Temporarily leave stdin & stdout open for `-d', 68 * and stderr open for any pre-syslog error messages. 69 */ 70 { 71 int i, nfds = getdtablesize(); 72 73 for (i = 0; i < nfds; i++) 74 if (i != fileno(stdin) && i != fileno(stdout) && 75 i != fileno(stderr)) 76 (void) close(i); 77 } 78 79 /* 80 * Parse any arguments. 81 */ 82 while ((c = getopt(argc, argv, "adi:")) != -1) 83 switch(c) { 84 case 'a': 85 BootAny++; 86 break; 87 case 'd': 88 DebugFlg++; 89 break; 90 case 'i': 91 IntfName = optarg; 92 break; 93 default: 94 usage(); 95 } 96 for (; optind < argc; optind++) { 97 if (ConfigFile == NULL) 98 ConfigFile = argv[optind]; 99 else { 100 warnx("too many config files (`%s' ignored)", 101 argv[optind]); 102 } 103 } 104 105 if (ConfigFile == NULL) /* use default config file */ 106 ConfigFile = DfltConfig; 107 108 if (DebugFlg) { 109 DbgFp = stdout; /* output to stdout */ 110 111 (void) signal(SIGUSR1, SIG_IGN); /* dont muck w/DbgFp */ 112 (void) signal(SIGUSR2, SIG_IGN); 113 (void) fclose(stderr); /* finished with it */ 114 } else { 115 if (daemon(0, 0)) 116 err(1, "can't detach from terminal"); 117 118 (void) signal(SIGUSR1, DebugOn); 119 (void) signal(SIGUSR2, DebugOff); 120 } 121 122 openlog("rbootd", LOG_PID, LOG_DAEMON); 123 124 /* 125 * If no interface was specified, get one now. 126 * 127 * This is convoluted because we want to get the default interface 128 * name for the syslog("restarted") message. If BpfGetIntfName() 129 * runs into an error, it will return a syslog-able error message 130 * (in `errmsg') which will be displayed here. 131 */ 132 if (IntfName == NULL) { 133 char *errmsg; 134 135 if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) { 136 /* Backslash to avoid trigraph '??)'. */ 137 syslog(LOG_NOTICE, "restarted (?\?)"); 138 /* BpfGetIntfName() returns safe names, using %m */ 139 syslog(LOG_ERR, "%s", errmsg); 140 Exit(0); 141 } 142 } 143 144 syslog(LOG_NOTICE, "restarted (%s)", IntfName); 145 146 (void) signal(SIGHUP, ReConfig); 147 (void) signal(SIGINT, Exit); 148 (void) signal(SIGTERM, Exit); 149 150 /* 151 * Grab our host name and pid. 152 */ 153 if (gethostname(MyHost, MAXHOSTNAMELEN - 1) < 0) { 154 syslog(LOG_ERR, "gethostname: %m"); 155 Exit(0); 156 } 157 MyHost[MAXHOSTNAMELEN - 1] = '\0'; 158 159 MyPid = getpid(); 160 161 /* 162 * Write proc's pid to a file. 163 */ 164 { 165 FILE *fp; 166 167 if ((fp = fopen(PidFile, "w")) != NULL) { 168 (void) fprintf(fp, "%d\n", (int) MyPid); 169 (void) fclose(fp); 170 } else { 171 syslog(LOG_WARNING, "fopen: failed (%s)", PidFile); 172 } 173 } 174 175 /* 176 * All boot files are relative to the boot directory, we might 177 * as well chdir() there to make life easier. 178 */ 179 if (chdir(BootDir) < 0) { 180 syslog(LOG_ERR, "chdir: %m (%s)", BootDir); 181 Exit(0); 182 } 183 184 /* 185 * Initial configuration. 186 */ 187 omask = sigblock(sigmask(SIGHUP)); /* prevent reconfig's */ 188 if (GetBootFiles() == 0) /* get list of boot files */ 189 Exit(0); 190 if (ParseConfig() == 0) /* parse config file */ 191 Exit(0); 192 193 /* 194 * Open and initialize a BPF device for the appropriate interface. 195 * If an error is encountered, a message is displayed and Exit() 196 * is called. 197 */ 198 fd = BpfOpen(); 199 200 (void) sigsetmask(omask); /* allow reconfig's */ 201 202 /* 203 * Main loop: receive a packet, determine where it came from, 204 * and if we service this host, call routine to handle request. 205 */ 206 maxfds = fd + 1; 207 FD_ZERO(&rset); 208 FD_SET(fd, &rset); 209 for (;;) { 210 struct timeval timeout; 211 fd_set r; 212 int nsel; 213 214 r = rset; 215 216 if (RmpConns == NULL) { /* timeout isn't necessary */ 217 nsel = select(maxfds, &r, NULL, NULL, NULL); 218 } else { 219 timeout.tv_sec = RMP_TIMEOUT; 220 timeout.tv_usec = 0; 221 nsel = select(maxfds, &r, NULL, NULL, &timeout); 222 } 223 224 if (nsel < 0) { 225 if (errno == EINTR) 226 continue; 227 syslog(LOG_ERR, "select: %m"); 228 Exit(0); 229 } else if (nsel == 0) { /* timeout */ 230 DoTimeout(); /* clear stale conns */ 231 continue; 232 } 233 234 if (FD_ISSET(fd, &r)) { 235 RMPCONN rconn; 236 CLIENT *client; 237 int doread = 1; 238 239 while (BpfRead(&rconn, doread)) { 240 doread = 0; 241 242 if (DbgFp != NULL) /* display packet */ 243 DispPkt(&rconn,DIR_RCVD); 244 245 omask = sigblock(sigmask(SIGHUP)); 246 247 /* 248 * If we do not restrict service, set the 249 * client to NULL (ProcessPacket() handles 250 * this). Otherwise, check that we can 251 * service this host; if not, log a message 252 * and ignore the packet. 253 */ 254 if (BootAny) { 255 client = NULL; 256 } else if ((client=FindClient(&rconn))==NULL) { 257 syslog(LOG_INFO, 258 "%s: boot packet ignored", 259 EnetStr(&rconn)); 260 (void) sigsetmask(omask); 261 continue; 262 } 263 264 ProcessPacket(&rconn,client); 265 266 (void) sigsetmask(omask); 267 } 268 } 269 } 270 } 271 272 static void 273 usage(void) 274 { 275 fprintf(stderr, "usage: rbootd [-ad] [-i interface] [config_file]\n"); 276 exit (1); 277 } 278 279 /* 280 ** DoTimeout -- Free any connections that have timed out. 281 ** 282 ** Parameters: 283 ** None. 284 ** 285 ** Returns: 286 ** Nothing. 287 ** 288 ** Side Effects: 289 ** - Timed out connections in `RmpConns' will be freed. 290 */ 291 void 292 DoTimeout(void) 293 { 294 RMPCONN *rtmp; 295 time_t now; 296 297 /* 298 * For each active connection, if RMP_TIMEOUT seconds have passed 299 * since the last packet was sent, delete the connection. 300 */ 301 now = time(NULL); 302 for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next) 303 if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now) { 304 syslog(LOG_WARNING, "%s: connection timed out (%u)", 305 EnetStr(rtmp), rtmp->rmp.r_type); 306 RemoveConn(rtmp); 307 } 308 } 309 310 /* 311 ** FindClient -- Find client associated with a packet. 312 ** 313 ** Parameters: 314 ** rconn - the new packet. 315 ** 316 ** Returns: 317 ** Pointer to client info if found, NULL otherwise. 318 ** 319 ** Side Effects: 320 ** None. 321 ** 322 ** Warnings: 323 ** - This routine must be called with SIGHUP blocked since 324 ** a reconfigure can invalidate the information returned. 325 */ 326 327 CLIENT * 328 FindClient(RMPCONN *rconn) 329 { 330 CLIENT *ctmp; 331 332 for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next) 333 if (bcmp((char *)&rconn->rmp.hp_hdr.saddr[0], 334 (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0) 335 break; 336 337 return(ctmp); 338 } 339 340 /* 341 ** Exit -- Log an error message and exit. 342 ** 343 ** Parameters: 344 ** sig - caught signal (or zero if not dying on a signal). 345 ** 346 ** Returns: 347 ** Does not return. 348 ** 349 ** Side Effects: 350 ** - This process ceases to exist. 351 */ 352 void 353 Exit(int sig) 354 { 355 if (sig > 0) 356 syslog(LOG_ERR, "going down on signal %d", sig); 357 else 358 syslog(LOG_ERR, "going down with fatal error"); 359 BpfClose(); 360 exit(1); 361 } 362 363 /* 364 ** ReConfig -- Get new list of boot files and reread config files. 365 ** 366 ** Parameters: 367 ** None. 368 ** 369 ** Returns: 370 ** Nothing. 371 ** 372 ** Side Effects: 373 ** - All active connections are dropped. 374 ** - List of boot-able files is changed. 375 ** - List of clients is changed. 376 ** 377 ** Warnings: 378 ** - This routine must be called with SIGHUP blocked. 379 */ 380 void 381 ReConfig(int signo __unused) 382 { 383 syslog(LOG_NOTICE, "reconfiguring boot server"); 384 385 FreeConns(); 386 387 if (GetBootFiles() == 0) 388 Exit(0); 389 390 if (ParseConfig() == 0) 391 Exit(0); 392 } 393 394 /* 395 ** DebugOff -- Turn off debugging. 396 ** 397 ** Parameters: 398 ** None. 399 ** 400 ** Returns: 401 ** Nothing. 402 ** 403 ** Side Effects: 404 ** - Debug file is closed. 405 */ 406 void 407 DebugOff(int signo __unused) 408 { 409 if (DbgFp != NULL) 410 (void) fclose(DbgFp); 411 412 DbgFp = NULL; 413 } 414 415 /* 416 ** DebugOn -- Turn on debugging. 417 ** 418 ** Parameters: 419 ** None. 420 ** 421 ** Returns: 422 ** Nothing. 423 ** 424 ** Side Effects: 425 ** - Debug file is opened/truncated if not already opened, 426 ** otherwise do nothing. 427 */ 428 void 429 DebugOn(int signo __unused) 430 { 431 if (DbgFp == NULL) { 432 if ((DbgFp = fopen(DbgFile, "w")) == NULL) 433 syslog(LOG_ERR, "can't open debug file (%s)", DbgFile); 434 } 435 } 436