1 /* 2 * Copyright (c) 1983, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by the University of 17 * California, Berkeley and its contributors. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#) Copyright (c) 1983, 1993, 1994 The Regents of the University of California. All rights reserved. 35 * @(#)lpd.c 8.7 (Berkeley) 5/10/95 36 * $FreeBSD: src/usr.sbin/lpr/lpd/lpd.c,v 1.12.2.22 2002/06/30 04:09:11 gad Exp $ 37 */ 38 39 /* 40 * lpd -- line printer daemon. 41 * 42 * Listen for a connection and perform the requested operation. 43 * Operations are: 44 * \1printer\n 45 * check the queue for jobs and print any found. 46 * \2printer\n 47 * receive a job from another machine and queue it. 48 * \3printer [users ...] [jobs ...]\n 49 * return the current state of the queue (short form). 50 * \4printer [users ...] [jobs ...]\n 51 * return the current state of the queue (long form). 52 * \5printer person [users ...] [jobs ...]\n 53 * remove jobs from the queue. 54 * 55 * Strategy to maintain protected spooling area: 56 * 1. Spooling area is writable only by daemon and spooling group 57 * 2. lpr runs setuid root and setgrp spooling group; it uses 58 * root to access any file it wants (verifying things before 59 * with an access call) and group id to know how it should 60 * set up ownership of files in the spooling area. 61 * 3. Files in spooling area are owned by root, group spooling 62 * group, with mode 660. 63 * 4. lpd, lpq and lprm run setuid daemon and setgrp spooling group to 64 * access files and printer. Users can't get to anything 65 * w/o help of lpq and lprm programs. 66 */ 67 68 #include <sys/param.h> 69 #include <sys/wait.h> 70 #include <sys/types.h> 71 #include <sys/socket.h> 72 #include <sys/un.h> 73 #include <sys/stat.h> 74 #include <sys/file.h> 75 #include <netinet/in.h> 76 #include <arpa/inet.h> 77 78 #include <netdb.h> 79 #include <unistd.h> 80 #include <syslog.h> 81 #include <signal.h> 82 #include <err.h> 83 #include <errno.h> 84 #include <fcntl.h> 85 #include <dirent.h> 86 #include <stdio.h> 87 #include <stdlib.h> 88 #include <string.h> 89 #include <sysexits.h> 90 #include <ctype.h> 91 #include "lp.h" 92 #include "lp.local.h" 93 #include "pathnames.h" 94 #include "extern.h" 95 96 int lflag; /* log requests flag */ 97 int sflag; /* no incoming port flag */ 98 int from_remote; /* from remote socket */ 99 100 static void reapchild(int _signo); 101 static void mcleanup(int _signo); 102 static void doit(void); 103 static void startup(void); 104 static void chkhost(struct sockaddr *_f, int _ch_opts); 105 static int ckqueue(struct printer *_pp); 106 static void fhosterr(int _ch_opts, char *_sysmsg, char *_usermsg); 107 static int *socksetup(int _af, int _debuglvl); 108 static void usage(void); 109 110 /* XXX from libc/net/rcmd.c */ 111 extern int __ivaliduser_sa(FILE *, struct sockaddr *, socklen_t, 112 const char *, const char *); 113 114 uid_t uid, euid; 115 116 #define LPD_NOPORTCHK 0001 /* skip reserved-port check */ 117 #define LPD_LOGCONNERR 0002 /* (sys)log connection errors */ 118 #define LPD_ADDFROMLINE 0004 /* just used for fhosterr() */ 119 120 int 121 main(int argc, char **argv) 122 { 123 int ch_options, errs, f, funix, *finet, i, lfd, socket_debug; 124 fd_set defreadfds; 125 struct sockaddr_un un, fromunix; 126 struct sockaddr_storage frominet; 127 socklen_t fromlen; 128 sigset_t omask, nmask; 129 struct servent *sp, serv; 130 int inet_flag = 0, inet6_flag = 0; 131 132 euid = geteuid(); /* these shouldn't be different */ 133 uid = getuid(); 134 135 ch_options = 0; 136 socket_debug = 0; 137 gethostname(local_host, sizeof(local_host)); 138 139 progname = "lpd"; 140 141 if (euid != 0) 142 errx(EX_NOPERM,"must run as root"); 143 144 errs = 0; 145 while ((i = getopt(argc, argv, "cdlpswW46")) != -1) 146 switch (i) { 147 case 'c': 148 /* log all kinds of connection-errors to syslog */ 149 ch_options |= LPD_LOGCONNERR; 150 break; 151 case 'd': 152 socket_debug++; 153 break; 154 case 'l': 155 lflag++; 156 break; 157 case 'p': /* letter initially used for -s */ 158 /* 159 * This will probably be removed with 5.0-release. 160 */ 161 /* FALLTHROUGH */ 162 case 's': /* secure (no inet) */ 163 sflag++; 164 break; 165 case 'w': /* netbsd uses -w for maxwait */ 166 /* 167 * This will be removed after the release of 4.4, as 168 * it conflicts with -w in netbsd's lpd. For now it 169 * is just a warning, so we won't suddenly break lpd 170 * for anyone who is currently using the option. 171 */ 172 syslog(LOG_WARNING, 173 "NOTE: the -w option has been renamed -W"); 174 syslog(LOG_WARNING, 175 "NOTE: please change your lpd config to use -W"); 176 /* FALLTHROUGH */ 177 case 'W': 178 /* allow connections coming from a non-reserved port */ 179 /* (done by some lpr-implementations for MS-Windows) */ 180 ch_options |= LPD_NOPORTCHK; 181 break; 182 case '4': 183 family = PF_INET; 184 inet_flag++; 185 break; 186 case '6': 187 #ifdef INET6 188 family = PF_INET6; 189 inet6_flag++; 190 #else 191 errx(EX_USAGE, "lpd compiled sans INET6 (IPv6 support)"); 192 #endif 193 break; 194 /* 195 * The following options are not in FreeBSD (yet?), but are 196 * listed here to "reserve" them, because the option-letters 197 * are used by either NetBSD or OpenBSD (as of July 2001). 198 */ 199 case 'b': /* set bind-addr */ 200 case 'n': /* set max num of children */ 201 case 'r': /* allow 'of' for remote ptrs */ 202 /* ...[not needed in freebsd] */ 203 /* FALLTHROUGH */ 204 default: 205 errs++; 206 } 207 if (inet_flag && inet6_flag) 208 family = PF_UNSPEC; 209 argc -= optind; 210 argv += optind; 211 if (errs) 212 usage(); 213 214 if (argc == 1) { 215 if ((i = atoi(argv[0])) == 0) 216 usage(); 217 if (i < 0 || i > USHRT_MAX) 218 errx(EX_USAGE, "port # %d is invalid", i); 219 220 serv.s_port = htons(i); 221 sp = &serv; 222 argc--; 223 } else { 224 sp = getservbyname("printer", "tcp"); 225 if (sp == NULL) 226 errx(EX_OSFILE, "printer/tcp: unknown service"); 227 } 228 229 if (argc != 0) 230 usage(); 231 232 /* 233 * We run chkprintcap right away to catch any errors and blat them 234 * to stderr while we still have it open, rather than sending them 235 * to syslog and leaving the user wondering why lpd started and 236 * then stopped. There should probably be a command-line flag to 237 * ignore errors from chkprintcap. 238 */ 239 { 240 pid_t pid; 241 int status; 242 pid = fork(); 243 if (pid < 0) { 244 err(EX_OSERR, "cannot fork"); 245 } else if (pid == 0) { /* child */ 246 execl(_PATH_CHKPRINTCAP, _PATH_CHKPRINTCAP, NULL); 247 err(EX_OSERR, "cannot execute %s", _PATH_CHKPRINTCAP); 248 } 249 if (waitpid(pid, &status, 0) < 0) { 250 err(EX_OSERR, "cannot wait"); 251 } 252 if (WIFEXITED(status) && WEXITSTATUS(status) != 0) 253 errx(EX_OSFILE, "%d errors in printcap file, exiting", 254 WEXITSTATUS(status)); 255 } 256 257 #ifndef DEBUG 258 /* 259 * Set up standard environment by detaching from the parent. 260 */ 261 daemon(0, 0); 262 #endif 263 264 openlog("lpd", LOG_PID, LOG_LPR); 265 syslog(LOG_INFO, "lpd startup: logging=%d%s%s", lflag, 266 socket_debug ? " dbg" : "", sflag ? " net-secure" : ""); 267 umask(0); 268 /* 269 * NB: This depends on O_NONBLOCK semantics doing the right thing; 270 * i.e., applying only to the O_EXLOCK and not to the rest of the 271 * open/creation. As of 1997-12-02, this is the case for commonly- 272 * used filesystems. There are other places in this code which 273 * make the same assumption. 274 */ 275 lfd = open(_PATH_MASTERLOCK, O_WRONLY|O_CREAT|O_EXLOCK|O_NONBLOCK, 276 LOCK_FILE_MODE); 277 if (lfd < 0) { 278 if (errno == EWOULDBLOCK) /* active daemon present */ 279 exit(0); 280 syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK); 281 exit(1); 282 } 283 fcntl(lfd, F_SETFL, 0); /* turn off non-blocking mode */ 284 ftruncate(lfd, 0); 285 /* 286 * write process id for others to know 287 */ 288 sprintf(line, "%u\n", getpid()); 289 f = strlen(line); 290 if (write(lfd, line, f) != f) { 291 syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK); 292 exit(1); 293 } 294 signal(SIGCHLD, reapchild); 295 /* 296 * Restart all the printers. 297 */ 298 startup(); 299 unlink(_PATH_SOCKETNAME); 300 funix = socket(AF_UNIX, SOCK_STREAM, 0); 301 if (funix < 0) { 302 syslog(LOG_ERR, "socket: %m"); 303 exit(1); 304 } 305 306 sigemptyset(&nmask); 307 sigaddset(&nmask, SIGHUP); 308 sigaddset(&nmask, SIGINT); 309 sigaddset(&nmask, SIGQUIT); 310 sigaddset(&nmask, SIGTERM); 311 sigprocmask(SIG_BLOCK, &nmask, &omask); 312 313 umask(07); 314 signal(SIGHUP, mcleanup); 315 signal(SIGINT, mcleanup); 316 signal(SIGQUIT, mcleanup); 317 signal(SIGTERM, mcleanup); 318 memset(&un, 0, sizeof(un)); 319 un.sun_family = AF_UNIX; 320 strcpy(un.sun_path, _PATH_SOCKETNAME); 321 #ifndef SUN_LEN 322 #define SUN_LEN(unp) (strlen((unp)->sun_path) + 2) 323 #endif 324 if (bind(funix, (struct sockaddr *)&un, SUN_LEN(&un)) < 0) { 325 syslog(LOG_ERR, "ubind: %m"); 326 exit(1); 327 } 328 umask(0); 329 sigprocmask(SIG_SETMASK, &omask, NULL); 330 FD_ZERO(&defreadfds); 331 FD_SET(funix, &defreadfds); 332 listen(funix, 5); 333 if (sflag == 0) { 334 finet = socksetup(family, socket_debug); 335 } else 336 finet = NULL; /* pretend we couldn't open TCP socket. */ 337 if (finet) { 338 for (i = 1; i <= *finet; i++) { 339 FD_SET(finet[i], &defreadfds); 340 listen(finet[i], 5); 341 } 342 } 343 /* 344 * Main loop: accept, do a request, continue. 345 */ 346 memset(&frominet, 0, sizeof(frominet)); 347 memset(&fromunix, 0, sizeof(fromunix)); 348 if (lflag) 349 syslog(LOG_INFO, "lpd startup: ready to accept requests"); 350 /* 351 * XXX - should be redone for multi-protocol 352 */ 353 for (;;) { 354 int domain, nfds, s; 355 fd_set readfds; 356 357 FD_COPY(&defreadfds, &readfds); 358 nfds = select(20, &readfds, 0, 0, 0); 359 if (nfds <= 0) { 360 if (nfds < 0 && errno != EINTR) 361 syslog(LOG_WARNING, "select: %m"); 362 continue; 363 } 364 domain = -1; /* avoid compile-time warning */ 365 s = -1; /* avoid compile-time warning */ 366 if (FD_ISSET(funix, &readfds)) { 367 domain = AF_UNIX, fromlen = sizeof(fromunix); 368 s = accept(funix, 369 (struct sockaddr *)&fromunix, &fromlen); 370 } else { 371 for (i = 1; i <= *finet; i++) 372 if (FD_ISSET(finet[i], &readfds)) { 373 domain = AF_INET; 374 fromlen = sizeof(frominet); 375 s = accept(finet[i], 376 (struct sockaddr *)&frominet, 377 &fromlen); 378 } 379 } 380 if (s < 0) { 381 if (errno != EINTR) 382 syslog(LOG_WARNING, "accept: %m"); 383 continue; 384 } 385 if (fork() == 0) { 386 /* 387 * Note that printjob() also plays around with 388 * signal-handling routines, and may need to be 389 * changed when making changes to signal-handling. 390 */ 391 signal(SIGCHLD, SIG_DFL); 392 signal(SIGHUP, SIG_IGN); 393 signal(SIGINT, SIG_IGN); 394 signal(SIGQUIT, SIG_IGN); 395 signal(SIGTERM, SIG_IGN); 396 close(funix); 397 if (sflag == 0 && finet) { 398 for (i = 1; i <= *finet; i++) 399 close(finet[i]); 400 } 401 dup2(s, 1); 402 close(s); 403 if (domain == AF_INET) { 404 /* for both AF_INET and AF_INET6 */ 405 from_remote = 1; 406 chkhost((struct sockaddr *)&frominet, 407 ch_options); 408 } else 409 from_remote = 0; 410 doit(); 411 exit(0); 412 } 413 close(s); 414 } 415 } 416 417 static void 418 reapchild(int signo __unused) 419 { 420 int status; 421 422 while (wait3(&status, WNOHANG, 0) > 0) 423 ; 424 } 425 426 static void 427 mcleanup(int signo) 428 { 429 /* 430 * XXX syslog(3) is not signal-safe. 431 */ 432 if (lflag) { 433 if (signo) 434 syslog(LOG_INFO, "exiting on signal %d", signo); 435 else 436 syslog(LOG_INFO, "exiting"); 437 } 438 unlink(_PATH_SOCKETNAME); 439 exit(0); 440 } 441 442 /* 443 * Stuff for handling job specifications 444 */ 445 char *user[MAXUSERS]; /* users to process */ 446 int users; /* # of users in user array */ 447 int requ[MAXREQUESTS]; /* job number of spool entries */ 448 int requests; /* # of spool requests */ 449 char *person; /* name of person doing lprm */ 450 451 /* buffer to hold the client's machine-name */ 452 static char frombuf[MAXHOSTNAMELEN]; 453 char cbuf[BUFSIZ]; /* command line buffer */ 454 const char *cmdnames[] = { 455 "null", 456 "printjob", 457 "recvjob", 458 "displayq short", 459 "displayq long", 460 "rmjob" 461 }; 462 463 static void 464 doit(void) 465 { 466 char *cp, *printer; 467 int n; 468 int status; 469 struct printer myprinter, *pp = &myprinter; 470 471 init_printer(&myprinter); 472 473 for (;;) { 474 cp = cbuf; 475 do { 476 if (cp >= &cbuf[sizeof(cbuf) - 1]) 477 fatal(0, "Command line too long"); 478 if ((n = read(STDOUT_FILENO, cp, 1)) != 1) { 479 if (n < 0) 480 fatal(0, "Lost connection"); 481 return; 482 } 483 } while (*cp++ != '\n'); 484 *--cp = '\0'; 485 cp = cbuf; 486 if (lflag) { 487 if (*cp >= '\1' && *cp <= '\5') 488 syslog(LOG_INFO, "%s requests %s %s", 489 from_host, cmdnames[(u_char)*cp], cp+1); 490 else 491 syslog(LOG_INFO, "bad request (%d) from %s", 492 *cp, from_host); 493 } 494 switch (*cp++) { 495 case CMD_CHECK_QUE: /* check the queue, print any jobs there */ 496 startprinting(cp); 497 break; 498 case CMD_TAKE_THIS: /* receive files to be queued */ 499 if (!from_remote) { 500 syslog(LOG_INFO, "illegal request (%d)", *cp); 501 exit(1); 502 } 503 recvjob(cp); 504 break; 505 case CMD_SHOWQ_SHORT: /* display the queue (short form) */ 506 case CMD_SHOWQ_LONG: /* display the queue (long form) */ 507 /* XXX - this all needs to be redone. */ 508 printer = cp; 509 while (*cp) { 510 if (*cp != ' ') { 511 cp++; 512 continue; 513 } 514 *cp++ = '\0'; 515 while (isspace(*cp)) 516 cp++; 517 if (*cp == '\0') 518 break; 519 if (isdigit(*cp)) { 520 if (requests >= MAXREQUESTS) 521 fatal(0, "Too many requests"); 522 requ[requests++] = atoi(cp); 523 } else { 524 if (users >= MAXUSERS) 525 fatal(0, "Too many users"); 526 user[users++] = cp; 527 } 528 } 529 status = getprintcap(printer, pp); 530 if (status < 0) 531 fatal(pp, "%s", pcaperr(status)); 532 displayq(pp, cbuf[0] == CMD_SHOWQ_LONG); 533 exit(0); 534 case CMD_RMJOB: /* remove a job from the queue */ 535 if (!from_remote) { 536 syslog(LOG_INFO, "illegal request (%d)", *cp); 537 exit(1); 538 } 539 printer = cp; 540 while (*cp && *cp != ' ') 541 cp++; 542 if (!*cp) 543 break; 544 *cp++ = '\0'; 545 person = cp; 546 while (*cp) { 547 if (*cp != ' ') { 548 cp++; 549 continue; 550 } 551 *cp++ = '\0'; 552 while (isspace(*cp)) 553 cp++; 554 if (*cp == '\0') 555 break; 556 if (isdigit(*cp)) { 557 if (requests >= MAXREQUESTS) 558 fatal(0, "Too many requests"); 559 requ[requests++] = atoi(cp); 560 } else { 561 if (users >= MAXUSERS) 562 fatal(0, "Too many users"); 563 user[users++] = cp; 564 } 565 } 566 rmjob(printer); 567 break; 568 } 569 fatal(0, "Illegal service request"); 570 } 571 } 572 573 /* 574 * Make a pass through the printcap database and start printing any 575 * files left from the last time the machine went down. 576 */ 577 static void 578 startup(void) 579 { 580 int pid, status, more; 581 struct printer myprinter, *pp = &myprinter; 582 583 more = firstprinter(pp, &status); 584 if (status) 585 goto errloop; 586 while (more) { 587 if (ckqueue(pp) <= 0) { 588 goto next; 589 } 590 if (lflag) 591 syslog(LOG_INFO, "lpd startup: work for %s", 592 pp->printer); 593 if ((pid = fork()) < 0) { 594 syslog(LOG_WARNING, "lpd startup: cannot fork for %s", 595 pp->printer); 596 mcleanup(0); 597 } 598 if (pid == 0) { 599 lastprinter(); 600 printjob(pp); 601 /* NOTREACHED */ 602 } 603 do { 604 next: 605 more = nextprinter(pp, &status); 606 errloop: 607 if (status) 608 syslog(LOG_WARNING, 609 "lpd startup: printcap entry for %s has errors, skipping", 610 pp->printer ? pp->printer : "<noname?>"); 611 } while (more && status); 612 } 613 } 614 615 /* 616 * Make sure there's some work to do before forking off a child 617 */ 618 static int 619 ckqueue(struct printer *pp) 620 { 621 struct dirent *d; 622 DIR *dirp; 623 char *spooldir; 624 625 spooldir = pp->spool_dir; 626 if ((dirp = opendir(spooldir)) == NULL) 627 return (-1); 628 while ((d = readdir(dirp)) != NULL) { 629 if (d->d_name[0] != 'c' || d->d_name[1] != 'f') 630 continue; /* daemon control files only */ 631 closedir(dirp); 632 return (1); /* found something */ 633 } 634 closedir(dirp); 635 return (0); 636 } 637 638 #define DUMMY ":nobody::" 639 640 /* 641 * Check to see if the host connecting to this host has access to any 642 * lpd services on this host. 643 */ 644 static void 645 chkhost(struct sockaddr *f, int ch_opts) 646 { 647 struct addrinfo hints, *res, *r; 648 FILE *hostf; 649 char hostbuf[NI_MAXHOST], ip[NI_MAXHOST]; 650 char serv[NI_MAXSERV]; 651 char *syserr, *usererr; 652 int error, errsav, fpass, good, wantsl; 653 654 wantsl = 0; 655 if (ch_opts & LPD_LOGCONNERR) 656 wantsl = 1; /* also syslog the errors */ 657 658 from_host = ".na."; 659 660 /* Need real hostname for temporary filenames */ 661 error = getnameinfo(f, f->sa_len, hostbuf, sizeof(hostbuf), NULL, 0, 662 NI_NAMEREQD); 663 if (error) { 664 errsav = error; 665 error = getnameinfo(f, f->sa_len, hostbuf, sizeof(hostbuf), 666 NULL, 0, NI_NUMERICHOST | NI_WITHSCOPEID); 667 if (error) { 668 asprintf(&syserr, 669 "can not determine hostname for remote host (%d,%d)", 670 errsav, error); 671 asprintf(&usererr, 672 "Host name for your address is not known"); 673 fhosterr(ch_opts, syserr, usererr); 674 /* NOTREACHED */ 675 } 676 asprintf(&syserr, 677 "Host name for remote host (%s) not known (%d)", 678 hostbuf, errsav); 679 asprintf(&usererr, 680 "Host name for your address (%s) is not known", 681 hostbuf); 682 fhosterr(ch_opts, syserr, usererr); 683 /* NOTREACHED */ 684 } 685 686 strlcpy(frombuf, hostbuf, sizeof(frombuf)); 687 from_host = frombuf; 688 ch_opts |= LPD_ADDFROMLINE; 689 690 /* Need address in stringform for comparison (no DNS lookup here) */ 691 error = getnameinfo(f, f->sa_len, hostbuf, sizeof(hostbuf), NULL, 0, 692 NI_NUMERICHOST | NI_WITHSCOPEID); 693 if (error) { 694 asprintf(&syserr, "Cannot print IP address (error %d)", 695 error); 696 asprintf(&usererr, "Cannot print IP address for your host"); 697 fhosterr(ch_opts, syserr, usererr); 698 /* NOTREACHED */ 699 } 700 from_ip = strdup(hostbuf); 701 702 /* Reject numeric addresses */ 703 memset(&hints, 0, sizeof(hints)); 704 hints.ai_family = family; 705 hints.ai_socktype = SOCK_DGRAM; /*dummy*/ 706 hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST; 707 if (getaddrinfo(from_host, NULL, &hints, &res) == 0) { 708 freeaddrinfo(res); 709 /* This syslog message already includes from_host */ 710 ch_opts &= ~LPD_ADDFROMLINE; 711 asprintf(&syserr, "reverse lookup results in non-FQDN %s", 712 from_host); 713 /* same message to both syslog and remote user */ 714 fhosterr(ch_opts, syserr, syserr); 715 /* NOTREACHED */ 716 } 717 718 /* Check for spoof, ala rlogind */ 719 memset(&hints, 0, sizeof(hints)); 720 hints.ai_family = family; 721 hints.ai_socktype = SOCK_DGRAM; /*dummy*/ 722 error = getaddrinfo(from_host, NULL, &hints, &res); 723 if (error) { 724 asprintf(&syserr, "dns lookup for address %s failed: %s", 725 from_ip, gai_strerror(error)); 726 asprintf(&usererr, "hostname for your address (%s) unknown: %s", 727 from_ip, gai_strerror(error)); 728 fhosterr(ch_opts, syserr, usererr); 729 /* NOTREACHED */ 730 } 731 good = 0; 732 for (r = res; good == 0 && r; r = r->ai_next) { 733 error = getnameinfo(r->ai_addr, r->ai_addrlen, ip, sizeof(ip), 734 NULL, 0, NI_NUMERICHOST | NI_WITHSCOPEID); 735 if (!error && !strcmp(from_ip, ip)) 736 good = 1; 737 } 738 if (res) 739 freeaddrinfo(res); 740 if (good == 0) { 741 asprintf(&syserr, "address for remote host (%s) not matched", 742 from_ip); 743 asprintf(&usererr, 744 "address for your hostname (%s) not matched", from_ip); 745 fhosterr(ch_opts, syserr, usererr); 746 /* NOTREACHED */ 747 } 748 749 fpass = 1; 750 hostf = fopen(_PATH_HOSTSEQUIV, "r"); 751 again: 752 if (hostf) { 753 if (__ivaliduser_sa(hostf, f, f->sa_len, DUMMY, DUMMY) == 0) { 754 fclose(hostf); 755 goto foundhost; 756 } 757 fclose(hostf); 758 } 759 if (fpass == 1) { 760 fpass = 2; 761 hostf = fopen(_PATH_HOSTSLPD, "r"); 762 goto again; 763 } 764 /* This syslog message already includes from_host */ 765 ch_opts &= ~LPD_ADDFROMLINE; 766 asprintf(&syserr, "refused connection from %s, sip=%s", from_host, 767 from_ip); 768 asprintf(&usererr, 769 "Print-services are not available to your host (%s).", from_host); 770 fhosterr(ch_opts, syserr, usererr); 771 /* NOTREACHED */ 772 773 foundhost: 774 if (ch_opts & LPD_NOPORTCHK) 775 return; /* skip the reserved-port check */ 776 777 error = getnameinfo(f, f->sa_len, NULL, 0, serv, sizeof(serv), 778 NI_NUMERICSERV); 779 if (error) { 780 /* same message to both syslog and remote user */ 781 asprintf(&syserr, "malformed from-address (%d)", error); 782 fhosterr(ch_opts, syserr, syserr); 783 /* NOTREACHED */ 784 } 785 786 if (atoi(serv) >= IPPORT_RESERVED) { 787 /* same message to both syslog and remote user */ 788 asprintf(&syserr, "connected from invalid port (%s)", serv); 789 fhosterr(ch_opts, syserr, syserr); 790 /* NOTREACHED */ 791 } 792 } 793 794 /* 795 * Handle fatal errors in chkhost. The first message will optionally be 796 * sent to syslog, the second one is sent to the connecting host. 797 * 798 * The idea is that the syslog message is meant for an administrator of a 799 * print server (the host receiving connections), while the usermsg is meant 800 * for a remote user who may or may not be clueful, and may or may not be 801 * doing something nefarious. Some remote users (eg, MS-Windows...) may not 802 * even see whatever message is sent, which is why there's the option to 803 * start 'lpd' with the connection-errors also sent to syslog. 804 * 805 * Given that hostnames can theoretically be fairly long (well, over 250 806 * bytes), it would probably be helpful to have the 'from_host' field at 807 * the end of any error messages which include that info. 808 * 809 * These are Fatal host-connection errors, so this routine does not return. 810 */ 811 static void 812 fhosterr(int ch_opts, char *sysmsg, char *usermsg) 813 { 814 815 /* 816 * If lpd was started up to print connection errors, then write 817 * the syslog message before the user message. 818 * And for many of the syslog messages, it is helpful to first 819 * write the from_host (if it is known) as a separate syslog 820 * message, since the hostname may be so long. 821 */ 822 if (ch_opts & LPD_LOGCONNERR) { 823 if (ch_opts & LPD_ADDFROMLINE) { 824 syslog(LOG_WARNING, "for connection from %s:", from_host); 825 } 826 syslog(LOG_WARNING, "%s", sysmsg); 827 } 828 829 /* 830 * Now send the error message to the remote host which is trying 831 * to make the connection. 832 */ 833 printf("%s [@%s]: %s\n", progname, local_host, usermsg); 834 fflush(stdout); 835 836 /* 837 * Add a minimal delay before exiting (and disconnecting from the 838 * sending-host). This is just in case that machine responds by 839 * INSTANTLY retrying (and instantly re-failing...). This may also 840 * give the other side more time to read the error message. 841 */ 842 sleep(2); /* a paranoid throttling measure */ 843 exit(1); 844 } 845 846 /* setup server socket for specified address family */ 847 /* if af is PF_UNSPEC more than one socket may be returned */ 848 /* the returned list is dynamically allocated, so caller needs to free it */ 849 static int * 850 socksetup(int af, int debuglvl) 851 { 852 struct addrinfo hints, *res, *r; 853 int error, maxs, *s, *socks; 854 const int on = 1; 855 856 memset(&hints, 0, sizeof(hints)); 857 hints.ai_flags = AI_PASSIVE; 858 hints.ai_family = af; 859 hints.ai_socktype = SOCK_STREAM; 860 error = getaddrinfo(NULL, "printer", &hints, &res); 861 if (error) { 862 syslog(LOG_ERR, "%s", gai_strerror(error)); 863 mcleanup(0); 864 } 865 866 /* Count max number of sockets we may open */ 867 for (maxs = 0, r = res; r; r = r->ai_next, maxs++) 868 ; 869 socks = malloc((maxs + 1) * sizeof(int)); 870 if (!socks) { 871 syslog(LOG_ERR, "couldn't allocate memory for sockets"); 872 mcleanup(0); 873 } 874 875 *socks = 0; /* num of sockets counter at start of array */ 876 s = socks + 1; 877 for (r = res; r; r = r->ai_next) { 878 *s = socket(r->ai_family, r->ai_socktype, r->ai_protocol); 879 if (*s < 0) { 880 syslog(LOG_DEBUG, "socket(): %m"); 881 continue; 882 } 883 if (setsockopt(*s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) 884 < 0) { 885 syslog(LOG_ERR, "setsockopt(SO_REUSEADDR): %m"); 886 close(*s); 887 continue; 888 } 889 if (debuglvl) 890 if (setsockopt(*s, SOL_SOCKET, SO_DEBUG, &debuglvl, 891 sizeof(debuglvl)) < 0) { 892 syslog(LOG_ERR, "setsockopt (SO_DEBUG): %m"); 893 close(*s); 894 continue; 895 } 896 #ifdef IPV6_BINDV6ONLY 897 if (r->ai_family == AF_INET6) { 898 if (setsockopt(*s, IPPROTO_IPV6, IPV6_BINDV6ONLY, 899 &on, sizeof(on)) < 0) { 900 syslog(LOG_ERR, 901 "setsockopt (IPV6_BINDV6ONLY): %m"); 902 close(*s); 903 continue; 904 } 905 } 906 #endif 907 if (bind(*s, r->ai_addr, r->ai_addrlen) < 0) { 908 syslog(LOG_DEBUG, "bind(): %m"); 909 close(*s); 910 continue; 911 } 912 (*socks)++; 913 s++; 914 } 915 916 if (res) 917 freeaddrinfo(res); 918 919 if (*socks == 0) { 920 syslog(LOG_ERR, "Couldn't bind to any socket"); 921 free(socks); 922 mcleanup(0); 923 } 924 return(socks); 925 } 926 927 static void 928 usage(void) 929 { 930 #ifdef INET6 931 fprintf(stderr, "usage: lpd [-cdlsW46] [port#]\n"); 932 #else 933 fprintf(stderr, "usage: lpd [-cdlsW] [port#]\n"); 934 #endif 935 exit(EX_USAGE); 936 } 937