lpd.c revision 1.11
1 /* $NetBSD: lpd.c,v 1.11 1997/07/17 05:49:13 mikel Exp $ */ 2 3 /* 4 * Copyright (c) 1983, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #include <sys/cdefs.h> 38 39 #ifndef lint 40 __COPYRIGHT("@(#) Copyright (c) 1983, 1993, 1994\n\ 41 The Regents of the University of California. All rights reserved.\n"); 42 #endif /* not lint */ 43 44 #ifndef lint 45 #if 0 46 static char sccsid[] = "@(#)lpd.c 8.4 (Berkeley) 4/17/94"; 47 #else 48 __RCSID("$NetBSD: lpd.c,v 1.11 1997/07/17 05:49:13 mikel Exp $"); 49 #endif 50 #endif /* not lint */ 51 52 /* 53 * lpd -- line printer daemon. 54 * 55 * Listen for a connection and perform the requested operation. 56 * Operations are: 57 * \1printer\n 58 * check the queue for jobs and print any found. 59 * \2printer\n 60 * receive a job from another machine and queue it. 61 * \3printer [users ...] [jobs ...]\n 62 * return the current state of the queue (short form). 63 * \4printer [users ...] [jobs ...]\n 64 * return the current state of the queue (long form). 65 * \5printer person [users ...] [jobs ...]\n 66 * remove jobs from the queue. 67 * 68 * Strategy to maintain protected spooling area: 69 * 1. Spooling area is writable only by daemon and spooling group 70 * 2. lpr runs setuid root and setgrp spooling group; it uses 71 * root to access any file it wants (verifying things before 72 * with an access call) and group id to know how it should 73 * set up ownership of files in the spooling area. 74 * 3. Files in spooling area are owned by root, group spooling 75 * group, with mode 660. 76 * 4. lpd, lpq and lprm run setuid daemon and setgrp spooling group to 77 * access files and printer. Users can't get to anything 78 * w/o help of lpq and lprm programs. 79 */ 80 81 #include <sys/param.h> 82 #include <sys/wait.h> 83 #include <sys/types.h> 84 #include <sys/socket.h> 85 #include <sys/un.h> 86 #include <sys/stat.h> 87 #include <netinet/in.h> 88 89 #include <netdb.h> 90 #include <unistd.h> 91 #include <syslog.h> 92 #include <signal.h> 93 #include <errno.h> 94 #include <fcntl.h> 95 #include <dirent.h> 96 #include <stdio.h> 97 #include <stdlib.h> 98 #include <string.h> 99 #include <ctype.h> 100 #include <arpa/inet.h> 101 102 #include "lp.h" 103 #include "lp.local.h" 104 #include "pathnames.h" 105 #include "extern.h" 106 107 int lflag; /* log requests flag */ 108 int sflag; /* secure (no inet) flag */ 109 int from_remote; /* from remote socket */ 110 111 int main __P((int, char **)); 112 static void reapchild __P((int)); 113 static void mcleanup __P((int)); 114 static void doit __P((void)); 115 static void startup __P((void)); 116 static void chkhost __P((struct sockaddr_in *)); 117 118 uid_t uid, euid; 119 120 int 121 main(argc, argv) 122 int argc; 123 char **argv; 124 { 125 int f, funix, finet, options, fromlen; 126 fd_set defreadfds; 127 struct sockaddr_un un, fromunix; 128 struct sockaddr_in sin, frominet; 129 int omask, lfd; 130 131 euid = geteuid(); /* these shouldn't be different */ 132 uid = getuid(); 133 options = 0; 134 gethostname(host, sizeof(host)); 135 name = argv[0]; 136 137 while (--argc > 0) { 138 argv++; 139 if (argv[0][0] == '-') 140 switch (argv[0][1]) { 141 case 'd': 142 options |= SO_DEBUG; 143 break; 144 case 'l': 145 lflag++; 146 break; 147 case 's': 148 sflag++; 149 break; 150 } 151 } 152 153 #ifndef DEBUG 154 /* 155 * Set up standard environment by detaching from the parent. 156 */ 157 daemon(0, 0); 158 #endif 159 160 openlog("lpd", LOG_PID, LOG_LPR); 161 syslog(LOG_INFO, "restarted"); 162 (void)umask(0); 163 lfd = open(_PATH_MASTERLOCK, O_WRONLY|O_CREAT, 0644); 164 if (lfd < 0) { 165 syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK); 166 exit(1); 167 } 168 if (flock(lfd, LOCK_EX|LOCK_NB) < 0) { 169 if (errno == EWOULDBLOCK) /* active deamon present */ 170 exit(0); 171 syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK); 172 exit(1); 173 } 174 ftruncate(lfd, 0); 175 /* 176 * write process id for others to know 177 */ 178 (void)snprintf(line, sizeof(line), "%u\n", getpid()); 179 f = strlen(line); 180 if (write(lfd, line, f) != f) { 181 syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK); 182 exit(1); 183 } 184 signal(SIGCHLD, reapchild); 185 /* 186 * Restart all the printers. 187 */ 188 startup(); 189 (void)unlink(_PATH_SOCKETNAME); 190 funix = socket(AF_UNIX, SOCK_STREAM, 0); 191 if (funix < 0) { 192 syslog(LOG_ERR, "socket: %m"); 193 exit(1); 194 } 195 #define mask(s) (1 << ((s) - 1)) 196 omask = sigblock(mask(SIGHUP)|mask(SIGINT)|mask(SIGQUIT)|mask(SIGTERM)); 197 signal(SIGHUP, mcleanup); 198 signal(SIGINT, mcleanup); 199 signal(SIGQUIT, mcleanup); 200 signal(SIGTERM, mcleanup); 201 memset(&un, 0, sizeof(un)); 202 un.sun_family = AF_UNIX; 203 strncpy(un.sun_path, _PATH_SOCKETNAME, sizeof(un.sun_path) - 1); 204 #ifndef SUN_LEN 205 #define SUN_LEN(unp) (strlen((unp)->sun_path) + 2) 206 #endif 207 if (bind(funix, (struct sockaddr *)&un, SUN_LEN(&un)) < 0) { 208 syslog(LOG_ERR, "ubind: %m"); 209 exit(1); 210 } 211 sigsetmask(omask); 212 FD_ZERO(&defreadfds); 213 FD_SET(funix, &defreadfds); 214 listen(funix, 5); 215 if (!sflag) 216 finet = socket(AF_INET, SOCK_STREAM, 0); 217 else 218 finet = -1; /* pretend we couldn't open TCP socket. */ 219 if (finet >= 0) { 220 struct servent *sp; 221 222 if (options & SO_DEBUG) 223 if (setsockopt(finet, SOL_SOCKET, SO_DEBUG, 0, 0) < 0) { 224 syslog(LOG_ERR, "setsockopt (SO_DEBUG): %m"); 225 mcleanup(0); 226 } 227 sp = getservbyname("printer", "tcp"); 228 if (sp == NULL) { 229 syslog(LOG_ERR, "printer/tcp: unknown service"); 230 mcleanup(0); 231 } 232 memset(&sin, 0, sizeof(sin)); 233 sin.sin_family = AF_INET; 234 sin.sin_port = sp->s_port; 235 if (bind(finet, (struct sockaddr *)&sin, sizeof(sin)) < 0) { 236 syslog(LOG_ERR, "bind: %m"); 237 mcleanup(0); 238 } 239 FD_SET(finet, &defreadfds); 240 listen(finet, 5); 241 } 242 /* 243 * Main loop: accept, do a request, continue. 244 */ 245 memset(&frominet, 0, sizeof(frominet)); 246 memset(&fromunix, 0, sizeof(fromunix)); 247 for (;;) { 248 int domain, nfds, s; 249 fd_set readfds; 250 251 FD_COPY(&defreadfds, &readfds); 252 nfds = select(20, &readfds, 0, 0, 0); 253 if (nfds <= 0) { 254 if (nfds < 0 && errno != EINTR) 255 syslog(LOG_WARNING, "select: %m"); 256 continue; 257 } 258 if (FD_ISSET(funix, &readfds)) { 259 domain = AF_UNIX, fromlen = sizeof(fromunix); 260 s = accept(funix, 261 (struct sockaddr *)&fromunix, &fromlen); 262 } else /* if (FD_ISSET(finet, &readfds)) */ { 263 domain = AF_INET, fromlen = sizeof(frominet); 264 s = accept(finet, 265 (struct sockaddr *)&frominet, &fromlen); 266 } 267 if (s < 0) { 268 if (errno != EINTR) 269 syslog(LOG_WARNING, "accept: %m"); 270 continue; 271 } 272 if (fork() == 0) { 273 signal(SIGCHLD, SIG_IGN); 274 signal(SIGHUP, SIG_IGN); 275 signal(SIGINT, SIG_IGN); 276 signal(SIGQUIT, SIG_IGN); 277 signal(SIGTERM, SIG_IGN); 278 (void)close(funix); 279 if (!sflag) 280 (void)close(finet); 281 dup2(s, 1); 282 (void)close(s); 283 if (domain == AF_INET) { 284 from_remote = 1; 285 chkhost(&frominet); 286 } else 287 from_remote = 0; 288 doit(); 289 exit(0); 290 } 291 (void)close(s); 292 } 293 } 294 295 static void 296 reapchild(signo) 297 int signo; 298 { 299 union wait status; 300 301 while (wait3((int *)&status, WNOHANG, 0) > 0) 302 ; 303 } 304 305 static void 306 mcleanup(signo) 307 int signo; 308 { 309 if (lflag) 310 syslog(LOG_INFO, "exiting"); 311 unlink(_PATH_SOCKETNAME); 312 exit(0); 313 } 314 315 /* 316 * Stuff for handling job specifications 317 */ 318 char *user[MAXUSERS]; /* users to process */ 319 int users; /* # of users in user array */ 320 int requ[MAXREQUESTS]; /* job number of spool entries */ 321 int requests; /* # of spool requests */ 322 char *person; /* name of person doing lprm */ 323 324 char fromb[MAXHOSTNAMELEN]; /* buffer for client's machine name */ 325 char cbuf[BUFSIZ]; /* command line buffer */ 326 char *cmdnames[] = { 327 "null", 328 "printjob", 329 "recvjob", 330 "displayq short", 331 "displayq long", 332 "rmjob" 333 }; 334 335 static void 336 doit() 337 { 338 register char *cp; 339 register int n; 340 341 for (;;) { 342 cp = cbuf; 343 do { 344 if (cp >= &cbuf[sizeof(cbuf) - 1]) 345 fatal("Command line too long"); 346 if ((n = read(1, cp, 1)) != 1) { 347 if (n < 0) 348 fatal("Lost connection"); 349 return; 350 } 351 } while (*cp++ != '\n'); 352 *--cp = '\0'; 353 cp = cbuf; 354 if (lflag) { 355 if (*cp >= '\1' && *cp <= '\5') 356 syslog(LOG_INFO, "%s requests %s %s", 357 from, cmdnames[(int)*cp], cp+1); 358 else 359 syslog(LOG_INFO, "bad request (%d) from %s", 360 *cp, from); 361 } 362 switch (*cp++) { 363 case '\1': /* check the queue and print any jobs there */ 364 printer = cp; 365 printjob(); 366 break; 367 case '\2': /* receive files to be queued */ 368 if (!from_remote) { 369 syslog(LOG_INFO, "illegal request (%d)", *cp); 370 exit(1); 371 } 372 printer = cp; 373 recvjob(); 374 break; 375 case '\3': /* display the queue (short form) */ 376 case '\4': /* display the queue (long form) */ 377 printer = cp; 378 while (*cp) { 379 if (*cp != ' ') { 380 cp++; 381 continue; 382 } 383 *cp++ = '\0'; 384 while (isspace(*cp)) 385 cp++; 386 if (*cp == '\0') 387 break; 388 if (isdigit(*cp)) { 389 if (requests >= MAXREQUESTS) 390 fatal("Too many requests"); 391 requ[requests++] = atoi(cp); 392 } else { 393 if (users >= MAXUSERS) 394 fatal("Too many users"); 395 user[users++] = cp; 396 } 397 } 398 displayq(cbuf[0] - '\3'); 399 exit(0); 400 case '\5': /* remove a job from the queue */ 401 if (!from_remote) { 402 syslog(LOG_INFO, "illegal request (%d)", *cp); 403 exit(1); 404 } 405 printer = cp; 406 while (*cp && *cp != ' ') 407 cp++; 408 if (!*cp) 409 break; 410 *cp++ = '\0'; 411 person = cp; 412 while (*cp) { 413 if (*cp != ' ') { 414 cp++; 415 continue; 416 } 417 *cp++ = '\0'; 418 while (isspace(*cp)) 419 cp++; 420 if (*cp == '\0') 421 break; 422 if (isdigit(*cp)) { 423 if (requests >= MAXREQUESTS) 424 fatal("Too many requests"); 425 requ[requests++] = atoi(cp); 426 } else { 427 if (users >= MAXUSERS) 428 fatal("Too many users"); 429 user[users++] = cp; 430 } 431 } 432 rmjob(); 433 break; 434 } 435 fatal("Illegal service request"); 436 } 437 } 438 439 /* 440 * Make a pass through the printcap database and start printing any 441 * files left from the last time the machine went down. 442 */ 443 static void 444 startup() 445 { 446 char *buf; 447 register char *cp; 448 int pid; 449 450 /* 451 * Restart the daemons. 452 */ 453 while (cgetnext(&buf, printcapdb) > 0) { 454 for (cp = buf; *cp; cp++) 455 if (*cp == '|' || *cp == ':') { 456 *cp = '\0'; 457 break; 458 } 459 if ((pid = fork()) < 0) { 460 syslog(LOG_WARNING, "startup: cannot fork"); 461 mcleanup(0); 462 } 463 if (!pid) { 464 printer = buf; 465 cgetclose(); 466 printjob(); 467 } 468 } 469 } 470 471 #define DUMMY ":nobody::" 472 473 /* 474 * Check to see if the from host has access to the line printer. 475 */ 476 static void 477 chkhost(f) 478 struct sockaddr_in *f; 479 { 480 register struct hostent *hp; 481 register FILE *hostf; 482 int first = 1; 483 484 f->sin_port = ntohs(f->sin_port); 485 if (f->sin_family != AF_INET || f->sin_port >= IPPORT_RESERVED) 486 fatal("Malformed from address"); 487 488 /* Need real hostname for temporary filenames */ 489 hp = gethostbyaddr((char *)&f->sin_addr, 490 sizeof(struct in_addr), f->sin_family); 491 if (hp == NULL) 492 fatal("Host name for your address (%s) unknown", 493 inet_ntoa(f->sin_addr)); 494 495 (void)strncpy(fromb, hp->h_name, sizeof(fromb) - 1); 496 from[sizeof(fromb) - 1] = '\0'; 497 from = fromb; 498 499 hostf = fopen(_PATH_HOSTSEQUIV, "r"); 500 again: 501 if (hostf) { 502 if (__ivaliduser(hostf, f->sin_addr.s_addr, 503 DUMMY, DUMMY) == 0) { 504 (void)fclose(hostf); 505 return; 506 } 507 (void)fclose(hostf); 508 } 509 if (first == 1) { 510 first = 0; 511 hostf = fopen(_PATH_HOSTSLPD, "r"); 512 goto again; 513 } 514 fatal("Your host does not have line printer access"); 515 /*NOTREACHED*/ 516 } 517
Indexes created Sun Sep 28 07:09:56 GMT 2025