1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include "lp.cdefs.h" /* A cross-platform version of <sys/cdefs.h> */ 34 /* 35 * lpd -- line printer daemon. 36 * 37 * Listen for a connection and perform the requested operation. 38 * Operations are: 39 * \1printer\n 40 * check the queue for jobs and print any found. 41 * \2printer\n 42 * receive a job from another machine and queue it. 43 * \3printer [users ...] [jobs ...]\n 44 * return the current state of the queue (short form). 45 * \4printer [users ...] [jobs ...]\n 46 * return the current state of the queue (long form). 47 * \5printer person [users ...] [jobs ...]\n 48 * remove jobs from the queue. 49 * 50 * Strategy to maintain protected spooling area: 51 * 1. Spooling area is writable only by daemon and spooling group 52 * 2. lpr runs setuid root and setgrp spooling group; it uses 53 * root to access any file it wants (verifying things before 54 * with an access call) and group id to know how it should 55 * set up ownership of files in the spooling area. 56 * 3. Files in spooling area are owned by root, group spooling 57 * group, with mode 660. 58 * 4. lpd, lpq and lprm run setuid daemon and setgrp spooling group to 59 * access files and printer. Users can't get to anything 60 * w/o help of lpq and lprm programs. 61 */ 62 63 #include <sys/param.h> 64 #include <sys/wait.h> 65 #include <sys/types.h> 66 #include <sys/socket.h> 67 #include <sys/un.h> 68 #include <sys/stat.h> 69 #include <sys/file.h> 70 #include <netinet/in.h> 71 #include <arpa/inet.h> 72 73 #include <netdb.h> 74 #include <unistd.h> 75 #include <syslog.h> 76 #include <signal.h> 77 #include <err.h> 78 #include <errno.h> 79 #include <fcntl.h> 80 #include <dirent.h> 81 #include <stdio.h> 82 #include <stdlib.h> 83 #include <string.h> 84 #include <sysexits.h> 85 #include <ctype.h> 86 #include "lp.h" 87 #include "lp.local.h" 88 #include "pathnames.h" 89 #include "extern.h" 90 91 int lflag; /* log requests flag */ 92 int sflag; /* no incoming port flag */ 93 int Fflag; /* run in foreground flag */ 94 int from_remote; /* from remote socket */ 95 96 int main(int argc, char **_argv); 97 static void reapchild(int _signo); 98 static void mcleanup(int _signo); 99 static void doit(void); 100 static void startup(void); 101 static void chkhost(struct sockaddr *_f, int _ch_opts); 102 static int ckqueue(struct printer *_pp); 103 static void fhosterr(int _ch_opts, char *_sysmsg, char *_usermsg); 104 static int *socksetup(int _af, int _debuglvl); 105 static void usage(void); 106 107 /* XXX from libc/net/rcmd.c */ 108 extern int __ivaliduser_sa(FILE *, struct sockaddr *, socklen_t, 109 const char *, const char *); 110 111 uid_t uid, euid; 112 113 #define LPD_NOPORTCHK 0001 /* skip reserved-port check */ 114 #define LPD_LOGCONNERR 0002 /* (sys)log connection errors */ 115 #define LPD_ADDFROMLINE 0004 /* just used for fhosterr() */ 116 117 int 118 main(int argc, char **argv) 119 { 120 int ch_options, errs, f, funix, *finet, i, lfd, socket_debug; 121 fd_set defreadfds; 122 struct sockaddr_un un, fromunix; 123 struct sockaddr_storage frominet; 124 socklen_t fromlen; 125 sigset_t omask, nmask; 126 struct servent *sp, serv; 127 int inet_flag = 0, inet6_flag = 0; 128 129 euid = geteuid(); /* these shouldn't be different */ 130 uid = getuid(); 131 132 ch_options = 0; 133 socket_debug = 0; 134 gethostname(local_host, sizeof(local_host)); 135 136 progname = "lpd"; 137 138 if (euid != 0) 139 errx(EX_NOPERM,"must run as root"); 140 141 errs = 0; 142 while ((i = getopt(argc, argv, "cdlpswFW46")) != -1) 143 switch (i) { 144 case 'c': 145 /* log all kinds of connection-errors to syslog */ 146 ch_options |= LPD_LOGCONNERR; 147 break; 148 case 'd': 149 socket_debug++; 150 break; 151 case 'l': 152 lflag++; 153 break; 154 case 'p': /* letter initially used for -s */ 155 /* 156 * This will probably be removed with 5.0-release. 157 */ 158 /* FALLTHROUGH */ 159 case 's': /* secure (no inet) */ 160 sflag++; 161 break; 162 case 'w': /* netbsd uses -w for maxwait */ 163 /* 164 * This will be removed after the release of 4.4, as 165 * it conflicts with -w in netbsd's lpd. For now it 166 * is just a warning, so we won't suddenly break lpd 167 * for anyone who is currently using the option. 168 */ 169 syslog(LOG_WARNING, 170 "NOTE: the -w option has been renamed -W"); 171 syslog(LOG_WARNING, 172 "NOTE: please change your lpd config to use -W"); 173 /* FALLTHROUGH */ 174 case 'F': 175 Fflag++; 176 break; 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, (char *)0); 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 #ifdef DEBUG 258 Fflag++; 259 #endif 260 /* 261 * Set up standard environment by detaching from the parent 262 * if -F not specified 263 */ 264 if (Fflag == 0) { 265 daemon(0, 0); 266 } 267 268 openlog("lpd", LOG_PID, LOG_LPR); 269 syslog(LOG_INFO, "lpd startup: logging=%d%s%s", lflag, 270 socket_debug ? " dbg" : "", sflag ? " net-secure" : ""); 271 (void) umask(0); 272 /* 273 * NB: This depends on O_NONBLOCK semantics doing the right thing; 274 * i.e., applying only to the O_EXLOCK and not to the rest of the 275 * open/creation. As of 1997-12-02, this is the case for commonly- 276 * used filesystems. There are other places in this code which 277 * make the same assumption. 278 */ 279 lfd = open(_PATH_MASTERLOCK, O_WRONLY|O_CREAT|O_EXLOCK|O_NONBLOCK, 280 LOCK_FILE_MODE); 281 if (lfd < 0) { 282 if (errno == EWOULDBLOCK) /* active daemon present */ 283 exit(0); 284 syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK); 285 exit(1); 286 } 287 fcntl(lfd, F_SETFL, 0); /* turn off non-blocking mode */ 288 ftruncate(lfd, 0); 289 /* 290 * write process id for others to know 291 */ 292 sprintf(line, "%u\n", getpid()); 293 f = strlen(line); 294 if (write(lfd, line, f) != f) { 295 syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK); 296 exit(1); 297 } 298 signal(SIGCHLD, reapchild); 299 /* 300 * Restart all the printers. 301 */ 302 startup(); 303 (void) unlink(_PATH_SOCKETNAME); 304 funix = socket(AF_UNIX, SOCK_STREAM, 0); 305 if (funix < 0) { 306 syslog(LOG_ERR, "socket: %m"); 307 exit(1); 308 } 309 310 sigemptyset(&nmask); 311 sigaddset(&nmask, SIGHUP); 312 sigaddset(&nmask, SIGINT); 313 sigaddset(&nmask, SIGQUIT); 314 sigaddset(&nmask, SIGTERM); 315 sigprocmask(SIG_BLOCK, &nmask, &omask); 316 317 (void) umask(07); 318 signal(SIGHUP, mcleanup); 319 signal(SIGINT, mcleanup); 320 signal(SIGQUIT, mcleanup); 321 signal(SIGTERM, mcleanup); 322 memset(&un, 0, sizeof(un)); 323 un.sun_family = AF_UNIX; 324 strcpy(un.sun_path, _PATH_SOCKETNAME); 325 #ifndef SUN_LEN 326 #define SUN_LEN(unp) (strlen((unp)->sun_path) + 2) 327 #endif 328 if (bind(funix, (struct sockaddr *)&un, SUN_LEN(&un)) < 0) { 329 syslog(LOG_ERR, "ubind: %m"); 330 exit(1); 331 } 332 (void) umask(0); 333 sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0); 334 FD_ZERO(&defreadfds); 335 FD_SET(funix, &defreadfds); 336 listen(funix, 5); 337 if (sflag == 0) { 338 finet = socksetup(family, socket_debug); 339 } else 340 finet = NULL; /* pretend we couldn't open TCP socket. */ 341 if (finet) { 342 for (i = 1; i <= *finet; i++) { 343 FD_SET(finet[i], &defreadfds); 344 listen(finet[i], 5); 345 } 346 } 347 /* 348 * Main loop: accept, do a request, continue. 349 */ 350 memset(&frominet, 0, sizeof(frominet)); 351 memset(&fromunix, 0, sizeof(fromunix)); 352 if (lflag) 353 syslog(LOG_INFO, "lpd startup: ready to accept requests"); 354 /* 355 * XXX - should be redone for multi-protocol 356 */ 357 for (;;) { 358 int domain, nfds, s; 359 fd_set readfds; 360 361 FD_COPY(&defreadfds, &readfds); 362 nfds = select(20, &readfds, 0, 0, 0); 363 if (nfds <= 0) { 364 if (nfds < 0 && errno != EINTR) 365 syslog(LOG_WARNING, "select: %m"); 366 continue; 367 } 368 domain = -1; /* avoid compile-time warning */ 369 s = -1; /* avoid compile-time warning */ 370 if (FD_ISSET(funix, &readfds)) { 371 domain = AF_UNIX, fromlen = sizeof(fromunix); 372 s = accept(funix, 373 (struct sockaddr *)&fromunix, &fromlen); 374 } else { 375 for (i = 1; i <= *finet; i++) 376 if (FD_ISSET(finet[i], &readfds)) { 377 domain = AF_INET; 378 fromlen = sizeof(frominet); 379 s = accept(finet[i], 380 (struct sockaddr *)&frominet, 381 &fromlen); 382 } 383 } 384 if (s < 0) { 385 if (errno != EINTR) 386 syslog(LOG_WARNING, "accept: %m"); 387 continue; 388 } 389 if (fork() == 0) { 390 /* 391 * Note that printjob() also plays around with 392 * signal-handling routines, and may need to be 393 * changed when making changes to signal-handling. 394 */ 395 signal(SIGCHLD, SIG_DFL); 396 signal(SIGHUP, SIG_IGN); 397 signal(SIGINT, SIG_IGN); 398 signal(SIGQUIT, SIG_IGN); 399 signal(SIGTERM, SIG_IGN); 400 (void) close(funix); 401 if (sflag == 0 && finet) { 402 for (i = 1; i <= *finet; i++) 403 (void)close(finet[i]); 404 } 405 dup2(s, STDOUT_FILENO); 406 (void) close(s); 407 if (domain == AF_INET) { 408 /* for both AF_INET and AF_INET6 */ 409 from_remote = 1; 410 chkhost((struct sockaddr *)&frominet, 411 ch_options); 412 } else 413 from_remote = 0; 414 doit(); 415 exit(0); 416 } 417 (void) close(s); 418 } 419 } 420 421 static void 422 reapchild(int signo __unused) 423 { 424 int status; 425 426 while (wait3(&status, WNOHANG, 0) > 0) 427 ; 428 } 429 430 static void 431 mcleanup(int signo) 432 { 433 /* 434 * XXX syslog(3) is not signal-safe. 435 */ 436 if (lflag) { 437 if (signo) 438 syslog(LOG_INFO, "exiting on signal %d", signo); 439 else 440 syslog(LOG_INFO, "exiting"); 441 } 442 unlink(_PATH_SOCKETNAME); 443 exit(0); 444 } 445 446 /* 447 * Stuff for handling job specifications 448 */ 449 char *user[MAXUSERS]; /* users to process */ 450 int users; /* # of users in user array */ 451 int requ[MAXREQUESTS]; /* job number of spool entries */ 452 int requests; /* # of spool requests */ 453 char *person; /* name of person doing lprm */ 454 455 /* buffer to hold the client's machine-name */ 456 static char frombuf[MAXHOSTNAMELEN]; 457 char cbuf[BUFSIZ]; /* command line buffer */ 458 const char *cmdnames[] = { 459 "null", 460 "printjob", 461 "recvjob", 462 "displayq short", 463 "displayq long", 464 "rmjob" 465 }; 466 467 static void 468 doit(void) 469 { 470 char *cp, *printer; 471 int n; 472 int status; 473 struct printer myprinter, *pp = &myprinter; 474 475 init_printer(&myprinter); 476 477 for (;;) { 478 cp = cbuf; 479 do { 480 if (cp >= &cbuf[sizeof(cbuf) - 1]) 481 fatal(0, "Command line too long"); 482 if ((n = read(STDOUT_FILENO, cp, 1)) != 1) { 483 if (n < 0) 484 fatal(0, "Lost connection"); 485 return; 486 } 487 } while (*cp++ != '\n'); 488 *--cp = '\0'; 489 cp = cbuf; 490 if (lflag) { 491 if (*cp >= '\1' && *cp <= '\5') 492 syslog(LOG_INFO, "%s requests %s %s", 493 from_host, cmdnames[(u_char)*cp], cp+1); 494 else 495 syslog(LOG_INFO, "bad request (%d) from %s", 496 *cp, from_host); 497 } 498 switch (*cp++) { 499 case CMD_CHECK_QUE: /* check the queue, print any jobs there */ 500 startprinting(cp); 501 break; 502 case CMD_TAKE_THIS: /* receive files to be queued */ 503 if (!from_remote) { 504 syslog(LOG_INFO, "illegal request (%d)", *cp); 505 exit(1); 506 } 507 recvjob(cp); 508 break; 509 case CMD_SHOWQ_SHORT: /* display the queue (short form) */ 510 case CMD_SHOWQ_LONG: /* display the queue (long form) */ 511 /* XXX - this all needs to be redone. */ 512 printer = cp; 513 while (*cp) { 514 if (*cp != ' ') { 515 cp++; 516 continue; 517 } 518 *cp++ = '\0'; 519 while (isspace(*cp)) 520 cp++; 521 if (*cp == '\0') 522 break; 523 if (isdigit(*cp)) { 524 if (requests >= MAXREQUESTS) 525 fatal(0, "Too many requests"); 526 requ[requests++] = atoi(cp); 527 } else { 528 if (users >= MAXUSERS) 529 fatal(0, "Too many users"); 530 user[users++] = cp; 531 } 532 } 533 status = getprintcap(printer, pp); 534 if (status < 0) 535 fatal(pp, "%s", pcaperr(status)); 536 displayq(pp, cbuf[0] == CMD_SHOWQ_LONG); 537 exit(0); 538 case CMD_RMJOB: /* remove a job from the queue */ 539 if (!from_remote) { 540 syslog(LOG_INFO, "illegal request (%d)", *cp); 541 exit(1); 542 } 543 printer = cp; 544 while (*cp && *cp != ' ') 545 cp++; 546 if (!*cp) 547 break; 548 *cp++ = '\0'; 549 person = cp; 550 while (*cp) { 551 if (*cp != ' ') { 552 cp++; 553 continue; 554 } 555 *cp++ = '\0'; 556 while (isspace(*cp)) 557 cp++; 558 if (*cp == '\0') 559 break; 560 if (isdigit(*cp)) { 561 if (requests >= MAXREQUESTS) 562 fatal(0, "Too many requests"); 563 requ[requests++] = atoi(cp); 564 } else { 565 if (users >= MAXUSERS) 566 fatal(0, "Too many users"); 567 user[users++] = cp; 568 } 569 } 570 rmjob(printer); 571 break; 572 } 573 fatal(0, "Illegal service request"); 574 } 575 } 576 577 /* 578 * Make a pass through the printcap database and start printing any 579 * files left from the last time the machine went down. 580 */ 581 static void 582 startup(void) 583 { 584 int pid, status, more; 585 struct printer myprinter, *pp = &myprinter; 586 587 more = firstprinter(pp, &status); 588 if (status) 589 goto errloop; 590 while (more) { 591 if (ckqueue(pp) <= 0) { 592 goto next; 593 } 594 if (lflag) 595 syslog(LOG_INFO, "lpd startup: work for %s", 596 pp->printer); 597 if ((pid = fork()) < 0) { 598 syslog(LOG_WARNING, "lpd startup: cannot fork for %s", 599 pp->printer); 600 mcleanup(0); 601 } 602 if (pid == 0) { 603 lastprinter(); 604 printjob(pp); 605 /* NOTREACHED */ 606 } 607 do { 608 next: 609 more = nextprinter(pp, &status); 610 errloop: 611 if (status) 612 syslog(LOG_WARNING, 613 "lpd startup: printcap entry for %s has errors, skipping", 614 pp->printer ? pp->printer : "<noname?>"); 615 } while (more && status); 616 } 617 } 618 619 /* 620 * Make sure there's some work to do before forking off a child 621 */ 622 static int 623 ckqueue(struct printer *pp) 624 { 625 register struct dirent *d; 626 DIR *dirp; 627 char *spooldir; 628 629 spooldir = pp->spool_dir; 630 if ((dirp = opendir(spooldir)) == NULL) 631 return (-1); 632 while ((d = readdir(dirp)) != NULL) { 633 if (d->d_name[0] != 'c' || d->d_name[1] != 'f') 634 continue; /* daemon control files only */ 635 closedir(dirp); 636 return (1); /* found something */ 637 } 638 closedir(dirp); 639 return (0); 640 } 641 642 #define DUMMY ":nobody::" 643 644 /* 645 * Check to see if the host connecting to this host has access to any 646 * lpd services on this host. 647 */ 648 static void 649 chkhost(struct sockaddr *f, int ch_opts) 650 { 651 struct addrinfo hints, *res, *r; 652 register FILE *hostf; 653 char hostbuf[NI_MAXHOST], ip[NI_MAXHOST]; 654 char serv[NI_MAXSERV]; 655 char *syserr, *usererr; 656 int error, errsav, fpass, good; 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); 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); 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); 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 (void) fclose(hostf); 755 goto foundhost; 756 } 757 (void) 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 if (r->ai_family == AF_INET6) { 897 if (setsockopt(*s, IPPROTO_IPV6, IPV6_V6ONLY, 898 &on, sizeof(on)) < 0) { 899 syslog(LOG_ERR, 900 "setsockopt (IPV6_V6ONLY): %m"); 901 close(*s); 902 continue; 903 } 904 } 905 if (bind(*s, r->ai_addr, r->ai_addrlen) < 0) { 906 syslog(LOG_DEBUG, "bind(): %m"); 907 close(*s); 908 continue; 909 } 910 (*socks)++; 911 s++; 912 } 913 914 if (res) 915 freeaddrinfo(res); 916 917 if (*socks == 0) { 918 syslog(LOG_ERR, "Couldn't bind to any socket"); 919 free(socks); 920 mcleanup(0); 921 } 922 return(socks); 923 } 924 925 static void 926 usage(void) 927 { 928 #ifdef INET6 929 fprintf(stderr, "usage: lpd [-cdlsFW46] [port#]\n"); 930 #else 931 fprintf(stderr, "usage: lpd [-cdlsFW] [port#]\n"); 932 #endif 933 exit(EX_USAGE); 934 } 935