xref: /netbsd-src/usr.sbin/lpr/lpd/lpd.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /*	$NetBSD: lpd.c,v 1.53 2005/12/02 11:33:39 yamt 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. 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 <sys/cdefs.h>
34 
35 #ifndef lint
36 __COPYRIGHT("@(#) Copyright (c) 1983, 1993, 1994\n\
37 	The Regents of the University of California.  All rights reserved.\n");
38 #endif /* not lint */
39 
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)lpd.c	8.7 (Berkeley) 5/10/95";
43 #else
44 __RCSID("$NetBSD: lpd.c,v 1.53 2005/12/02 11:33:39 yamt Exp $");
45 #endif
46 #endif /* not lint */
47 
48 /*
49  * lpd -- line printer daemon.
50  *
51  * Listen for a connection and perform the requested operation.
52  * Operations are:
53  *	\1printer\n
54  *		check the queue for jobs and print any found.
55  *	\2printer\n
56  *		receive a job from another machine and queue it.
57  *	\3printer [users ...] [jobs ...]\n
58  *		return the current state of the queue (short form).
59  *	\4printer [users ...] [jobs ...]\n
60  *		return the current state of the queue (long form).
61  *	\5printer person [users ...] [jobs ...]\n
62  *		remove jobs from the queue.
63  *
64  * Strategy to maintain protected spooling area:
65  *	1. Spooling area is writable only by daemon and spooling group
66  *	2. lpr runs setuid root and setgrp spooling group; it uses
67  *	   root to access any file it wants (verifying things before
68  *	   with an access call) and group id to know how it should
69  *	   set up ownership of files in the spooling area.
70  *	3. Files in spooling area are owned by root, group spooling
71  *	   group, with mode 660.
72  *	4. lpd, lpq and lprm run setuid daemon and setgrp spooling group to
73  *	   access files and printer.  Users can't get to anything
74  *	   w/o help of lpq and lprm programs.
75  */
76 
77 #include <sys/param.h>
78 #include <sys/wait.h>
79 #include <sys/types.h>
80 #include <sys/socket.h>
81 #include <sys/un.h>
82 #include <sys/stat.h>
83 #include <sys/file.h>
84 #include <sys/poll.h>
85 #include <netinet/in.h>
86 
87 #include <err.h>
88 #include <netdb.h>
89 #include <unistd.h>
90 #include <syslog.h>
91 #include <signal.h>
92 #include <errno.h>
93 #include <fcntl.h>
94 #include <dirent.h>
95 #include <stdarg.h>
96 #include <stdio.h>
97 #include <stdlib.h>
98 #include <string.h>
99 #include <ctype.h>
100 #include <arpa/inet.h>
101 
102 #ifdef LIBWRAP
103 #include <tcpd.h>
104 #endif
105 
106 #include "lp.h"
107 #include "lp.local.h"
108 #include "pathnames.h"
109 #include "extern.h"
110 
111 /* XXX from libc/net/rcmd.c */
112 extern int __ivaliduser_sa(FILE *, const struct sockaddr *, socklen_t,
113 			   const char *, const char *);
114 
115 #ifdef LIBWRAP
116 int allow_severity = LOG_AUTH|LOG_INFO;
117 int deny_severity = LOG_AUTH|LOG_WARNING;
118 #endif
119 
120 int	lflag;				/* log requests flag */
121 int	rflag;				/* allow of for remote printers */
122 int	sflag;				/* secure (no inet) flag */
123 int	from_remote;			/* from remote socket */
124 char	**blist;			/* list of addresses to bind(2) to */
125 int	blist_size;
126 int	blist_addrs;
127 
128 int			main(int, char **);
129 static void		reapchild(int);
130 static void		mcleanup(int);
131 static void		doit(void);
132 static void		startup(void);
133 static void		chkhost(struct sockaddr *, int);
134 static void		usage(void);
135 static struct pollfd	*socksetup(int, int, const char *, int *);
136 
137 uid_t	uid, euid;
138 int child_count;
139 
140 #define LPD_NOPORTCHK	0001		/* skip reserved-port check */
141 
142 int
143 main(int argc, char **argv)
144 {
145 	struct sockaddr_storage frm;
146 	socklen_t frmlen;
147 	sigset_t nmask, omask;
148 	int lfd, errs, i, f, nfds;
149 	struct pollfd *socks;
150 	int child_max = 32;	/* more than enough to hose the system */
151 	int options = 0, check_options = 0;
152 	struct servent *sp;
153 	const char *port = "printer";
154 	char **newblist;
155 
156 	euid = geteuid();	/* these shouldn't be different */
157 	uid = getuid();
158 	gethostname(host, sizeof(host));
159 	host[sizeof(host) - 1] = '\0';
160 	setprogname(*argv);
161 
162 	errs = 0;
163 	while ((i = getopt(argc, argv, "b:dln:srw:W")) != -1)
164 		switch (i) {
165 		case 'b':
166 			if (blist_addrs >= blist_size) {
167 				newblist = realloc(blist,
168 				    blist_size + sizeof(char *) * 4);
169 				if (newblist == NULL)
170 					err(1, "cant allocate bind addr list");
171 				blist = newblist;
172 				blist_size += sizeof(char *) * 4;
173 			}
174 			blist[blist_addrs++] = strdup(optarg);
175 			break;
176 		case 'd':
177 			options |= SO_DEBUG;
178 			break;
179 		case 'l':
180 			lflag++;
181 			break;
182 		case 'n':
183 			child_max = atoi(optarg);
184 			if (child_max < 0 || child_max > 1024)
185 				errx(1, "invalid number of children: %s",
186 				    optarg);
187 			break;
188 		case 'r':
189 			rflag++;
190 			break;
191 		case 's':
192 			sflag++;
193 			break;
194 		case 'w':
195 			wait_time = atoi(optarg);
196 			if (wait_time < 0)
197 				errx(1, "wait time must be postive: %s",
198 				    optarg);
199 			if (wait_time < 30)
200 			    warnx("warning: wait time less than 30 seconds");
201 			break;
202 		case 'W':/* allow connections coming from a non-reserved port */
203 			 /* (done by some lpr-implementations for MS-Windows) */
204 			check_options |= LPD_NOPORTCHK;
205 			break;
206 		default:
207 			errs++;
208 		}
209 	argc -= optind;
210 	argv += optind;
211 	if (errs)
212 		usage();
213 
214 	switch (argc) {
215 	case 1:
216 		if ((i = atoi(argv[0])) == 0)
217 			usage();
218 		if (i < 0 || i > USHRT_MAX)
219 			errx(1, "port # %d is invalid", i);
220 
221 		port = argv[0];
222 		break;
223 	case 0:
224 		sp = getservbyname(port, "tcp");
225 		if (sp == NULL)
226 			errx(1, "%s/tcp: unknown service", port);
227 		break;
228 	default:
229 		usage();
230 	}
231 
232 #ifndef DEBUG
233 	/*
234 	 * Set up standard environment by detaching from the parent.
235 	 */
236 	daemon(0, 0);
237 #endif
238 
239 	openlog("lpd", LOG_PID, LOG_LPR);
240 	syslog(LOG_INFO, "restarted");
241 	(void)umask(0);
242 	lfd = open(_PATH_MASTERLOCK, O_WRONLY|O_CREAT, 0644);
243 	if (lfd < 0) {
244 		syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK);
245 		exit(1);
246 	}
247 	if (flock(lfd, LOCK_EX|LOCK_NB) < 0) {
248 		if (errno == EWOULDBLOCK) {	/* active daemon present */
249 			syslog(LOG_ERR, "%s is locked; another lpd is running",
250 			    _PATH_MASTERLOCK);
251 			exit(0);
252 		}
253 		syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK);
254 		exit(1);
255 	}
256 	ftruncate(lfd, 0);
257 	/*
258 	 * write process id for others to know
259 	 */
260 	(void)snprintf(line, sizeof(line), "%u\n", getpid());
261 	f = strlen(line);
262 	if (write(lfd, line, f) != f) {
263 		syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK);
264 		exit(1);
265 	}
266 	signal(SIGCHLD, reapchild);
267 	/*
268 	 * Restart all the printers.
269 	 */
270 	startup();
271 
272 	sigemptyset(&nmask);
273 	sigaddset(&nmask, SIGHUP);
274 	sigaddset(&nmask, SIGINT);
275 	sigaddset(&nmask, SIGQUIT);
276 	sigaddset(&nmask, SIGTERM);
277 	sigprocmask(SIG_BLOCK, &nmask, &omask);
278 
279 	signal(SIGHUP, mcleanup);
280 	signal(SIGINT, mcleanup);
281 	signal(SIGQUIT, mcleanup);
282 	signal(SIGTERM, mcleanup);
283 
284 	socks = socksetup(PF_UNSPEC, options, port, &nfds);
285 
286 	sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
287 
288 	if (blist != NULL) {
289 		for (i = 0; i < blist_addrs; i++)
290 			free(blist[i]);
291 		free(blist);
292 	}
293 
294 	/*
295 	 * Main loop: accept, do a request, continue.
296 	 */
297 	memset(&frm, 0, sizeof(frm));
298 	for (;;) {
299 		int rv, s;
300 		/* "short" so it overflows in about 2 hours */
301 		struct timespec sleeptime = {10, 0};
302 
303 		while (child_max < child_count) {
304 			syslog(LOG_WARNING,
305 			    "too many children, sleeping for %ld seconds",
306 				(long)sleeptime.tv_sec);
307 			nanosleep(&sleeptime, NULL);
308 			sleeptime.tv_sec <<= 1;
309 			if (sleeptime.tv_sec <= 0) {
310 				syslog(LOG_CRIT, "sleeptime overflowed! help!");
311 				sleeptime.tv_sec = 10;
312 			}
313 		}
314 
315 		rv = poll(socks, nfds, INFTIM);
316 		if (rv <= 0) {
317 			if (rv < 0 && errno != EINTR)
318 				syslog(LOG_WARNING, "poll: %m");
319 			continue;
320 		}
321 		s = -1;
322                 for (i = 0; i < nfds; i++)
323 			if (socks[i].revents & POLLIN) {
324 				frmlen = sizeof(frm);
325 				s = accept(socks[i].fd,
326 				    (struct sockaddr *)&frm, &frmlen);
327 				break;
328 			}
329 		if (s < 0) {
330 			if (errno != EINTR)
331 				syslog(LOG_WARNING, "accept: %m");
332 			continue;
333 		}
334 
335 		switch (fork()) {
336 		case 0:
337 			signal(SIGCHLD, SIG_IGN);
338 			signal(SIGHUP, SIG_IGN);
339 			signal(SIGINT, SIG_IGN);
340 			signal(SIGQUIT, SIG_IGN);
341 			signal(SIGTERM, SIG_IGN);
342                        	for (i = 0; i < nfds; i++)
343 				(void)close(socks[i].fd);
344 			dup2(s, STDOUT_FILENO);
345 			(void)close(s);
346 			if (frm.ss_family != AF_LOCAL) {
347 				/* for both AF_INET and AF_INET6 */
348 				from_remote = 1;
349 				chkhost((struct sockaddr *)&frm, check_options);
350 			} else
351 				from_remote = 0;
352 			doit();
353 			exit(0);
354 		case -1:
355 			syslog(LOG_WARNING, "fork: %m, sleeping for 10 seconds...");
356 			sleep(10);
357 			continue;
358 		default:
359 			child_count++;
360 		}
361 		(void)close(s);
362 	}
363 }
364 
365 static void
366 reapchild(int signo)
367 {
368 	union wait status;
369 
370 	while (wait3((int *)&status, WNOHANG, 0) > 0)
371 		child_count--;
372 }
373 
374 static void
375 mcleanup(int signo)
376 {
377 	if (lflag)
378 		syslog(LOG_INFO, "exiting");
379 	unlink(_PATH_SOCKETNAME);
380 	exit(0);
381 }
382 
383 /*
384  * Stuff for handling job specifications
385  */
386 char	*user[MAXUSERS];	/* users to process */
387 int	users;			/* # of users in user array */
388 int	requ[MAXREQUESTS];	/* job number of spool entries */
389 int	requests;		/* # of spool requests */
390 char	*person;		/* name of person doing lprm */
391 
392 char	fromb[NI_MAXHOST];	/* buffer for client's machine name */
393 char	cbuf[BUFSIZ];		/* command line buffer */
394 const char *cmdnames[] = {
395 	"null",
396 	"printjob",
397 	"recvjob",
398 	"displayq short",
399 	"displayq long",
400 	"rmjob"
401 };
402 
403 static void
404 doit(void)
405 {
406 	char *cp;
407 	int n;
408 
409 	for (;;) {
410 		cp = cbuf;
411 		do {
412 			if (cp >= &cbuf[sizeof(cbuf) - 1])
413 				fatal("Command line too long");
414 			if ((n = read(STDOUT_FILENO, cp, 1)) != 1) {
415 				if (n < 0)
416 					fatal("Lost connection");
417 				return;
418 			}
419 		} while (*cp++ != '\n');
420 		*--cp = '\0';
421 		cp = cbuf;
422 		if (lflag) {
423 			if (*cp >= '\1' && *cp <= '\5') {
424 				syslog(LOG_INFO, "%s requests %s %s",
425 					from, cmdnames[(int)*cp], cp+1);
426 				setproctitle("serving %s: %s %s", from,
427 				    cmdnames[(int)*cp], cp+1);
428 			}
429 			else
430 				syslog(LOG_INFO, "bad request (%d) from %s",
431 					*cp, from);
432 		}
433 		switch (*cp++) {
434 		case '\1':	/* check the queue and print any jobs there */
435 			printer = cp;
436 			if (*printer == '\0')
437 				printer = DEFLP;
438 			printjob();
439 			break;
440 		case '\2':	/* receive files to be queued */
441 			if (!from_remote) {
442 				syslog(LOG_INFO, "illegal request (%d)", *cp);
443 				exit(1);
444 			}
445 			printer = cp;
446 			if (*printer == '\0')
447 				printer = DEFLP;
448 			recvjob();
449 			break;
450 		case '\3':	/* display the queue (short form) */
451 		case '\4':	/* display the queue (long form) */
452 			printer = cp;
453 			if (*printer == '\0')
454 				printer = DEFLP;
455 			while (*cp) {
456 				if (*cp != ' ') {
457 					cp++;
458 					continue;
459 				}
460 				*cp++ = '\0';
461 				while (isspace((unsigned char)*cp))
462 					cp++;
463 				if (*cp == '\0')
464 					break;
465 				if (isdigit((unsigned char)*cp)) {
466 					if (requests >= MAXREQUESTS)
467 						fatal("Too many requests");
468 					requ[requests++] = atoi(cp);
469 				} else {
470 					if (users >= MAXUSERS)
471 						fatal("Too many users");
472 					user[users++] = cp;
473 				}
474 			}
475 			displayq(cbuf[0] - '\3');
476 			exit(0);
477 		case '\5':	/* remove a job from the queue */
478 			if (!from_remote) {
479 				syslog(LOG_INFO, "illegal request (%d)", *cp);
480 				exit(1);
481 			}
482 			printer = cp;
483 			if (*printer == '\0')
484 				printer = DEFLP;
485 			while (*cp && *cp != ' ')
486 				cp++;
487 			if (!*cp)
488 				break;
489 			*cp++ = '\0';
490 			person = cp;
491 			while (*cp) {
492 				if (*cp != ' ') {
493 					cp++;
494 					continue;
495 				}
496 				*cp++ = '\0';
497 				while (isspace((unsigned char)*cp))
498 					cp++;
499 				if (*cp == '\0')
500 					break;
501 				if (isdigit((unsigned char)*cp)) {
502 					if (requests >= MAXREQUESTS)
503 						fatal("Too many requests");
504 					requ[requests++] = atoi(cp);
505 				} else {
506 					if (users >= MAXUSERS)
507 						fatal("Too many users");
508 					user[users++] = cp;
509 				}
510 			}
511 			rmjob();
512 			break;
513 		}
514 		fatal("Illegal service request");
515 	}
516 }
517 
518 /*
519  * Make a pass through the printcap database and start printing any
520  * files left from the last time the machine went down.
521  */
522 static void
523 startup(void)
524 {
525 	char *buf;
526 	char *cp;
527 
528 	/*
529 	 * Restart the daemons.
530 	 */
531 	while (cgetnext(&buf, printcapdb) > 0) {
532 		if (ckqueue(buf) <= 0) {
533 			free(buf);
534 			continue;	/* no work to do for this printer */
535 		}
536 		for (cp = buf; *cp; cp++)
537 			if (*cp == '|' || *cp == ':') {
538 				*cp = '\0';
539 				break;
540 			}
541 		if (lflag)
542 			syslog(LOG_INFO, "work for %s", buf);
543 		switch (fork()) {
544 		case -1:
545 			syslog(LOG_WARNING, "startup: cannot fork");
546 			mcleanup(0);
547 		case 0:
548 			printer = buf;
549 			setproctitle("working on printer %s", printer);
550 			cgetclose();
551 			printjob();
552 			/* NOTREACHED */
553 		default:
554 			child_count++;
555 			free(buf);
556 		}
557 	}
558 }
559 
560 #define DUMMY ":nobody::"
561 
562 /*
563  * Check to see if the from host has access to the line printer.
564  */
565 static void
566 chkhost(struct sockaddr *f, int check_opts)
567 {
568 	struct addrinfo hints, *res, *r;
569 	FILE *hostf;
570 	int good = 0;
571 	char hst[NI_MAXHOST], ip[NI_MAXHOST];
572 	char serv[NI_MAXSERV];
573 	int error;
574 #ifdef LIBWRAP
575 	struct request_info req;
576 #endif
577 
578 	error = getnameinfo(f, f->sa_len, NULL, 0, serv, sizeof(serv),
579 			    NI_NUMERICSERV);
580 	if (error)
581 		fatal("Malformed from address: %s", gai_strerror(error));
582 
583          if (!(check_opts & LPD_NOPORTCHK) &&
584 	       atoi(serv) >= IPPORT_RESERVED)
585 		fatal("Connect from invalid port (%s)", serv);
586 
587 	/* Need real hostname for temporary filenames */
588 	error = getnameinfo(f, f->sa_len, hst, sizeof(hst), NULL, 0,
589 			    NI_NAMEREQD);
590 	if (error) {
591 		error = getnameinfo(f, f->sa_len, hst, sizeof(hst), NULL, 0,
592 				    NI_NUMERICHOST);
593 		if (error)
594 			fatal("Host name for your address unknown");
595 		else
596 			fatal("Host name for your address (%s) unknown", hst);
597 	}
598 
599 	(void)strlcpy(fromb, hst, sizeof(fromb));
600 	from = fromb;
601 
602 	/* need address in stringform for comparison (no DNS lookup here) */
603 	error = getnameinfo(f, f->sa_len, hst, sizeof(hst), NULL, 0,
604 			    NI_NUMERICHOST);
605 	if (error)
606 		fatal("Cannot print address");
607 
608 	/* Check for spoof, ala rlogind */
609 	memset(&hints, 0, sizeof(hints));
610 	hints.ai_family = PF_UNSPEC;
611 	hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
612 	error = getaddrinfo(fromb, NULL, &hints, &res);
613 	if (error) {
614 		fatal("hostname for your address (%s) unknown: %s", hst,
615 		    gai_strerror(error));
616 	}
617 	good = 0;
618 	for (r = res; good == 0 && r; r = r->ai_next) {
619 		error = getnameinfo(r->ai_addr, r->ai_addrlen, ip, sizeof(ip),
620 				    NULL, 0, NI_NUMERICHOST);
621 		if (!error && !strcmp(hst, ip))
622 			good = 1;
623 	}
624 	if (res)
625 		freeaddrinfo(res);
626 	if (good == 0)
627 		fatal("address for your hostname (%s) not matched", hst);
628 
629 	setproctitle("serving %s", from);
630 
631 #ifdef LIBWRAP
632 	request_init(&req, RQ_DAEMON, "lpd", RQ_CLIENT_SIN, f,
633 	    RQ_FILE, STDOUT_FILENO, NULL);
634 	fromhost(&req);
635 	if (!hosts_access(&req))
636 		goto denied;
637 #endif
638 
639 	hostf = fopen(_PATH_HOSTSEQUIV, "r");
640 	if (hostf) {
641 		if (__ivaliduser_sa(hostf, f, f->sa_len, DUMMY, DUMMY) == 0) {
642 			(void)fclose(hostf);
643 			return;
644 		}
645 		(void)fclose(hostf);
646 	}
647 	hostf = fopen(_PATH_HOSTSLPD, "r");
648 	if (hostf) {
649 		if (__ivaliduser_sa(hostf, f, f->sa_len, DUMMY, DUMMY) == 0) {
650 			(void)fclose(hostf);
651 			return;
652 		}
653 		(void)fclose(hostf);
654 	}
655 #ifdef LIBWRAP
656   denied:
657 #endif
658 	fatal("Your host does not have line printer access");
659 	/*NOTREACHED*/
660 }
661 
662 
663 static void
664 usage(void)
665 {
666 
667 	(void)fprintf(stderr,
668 	    "Usage: %s [-dlrsW] [-b bind-address] [-n maxchild] "
669 	    "[-w maxwait] [port]\n", getprogname());
670 	exit(1);
671 }
672 
673 /* setup server socket for specified address family */
674 /* if af is PF_UNSPEC more than one socket may be returned */
675 /* the returned list is dynamically allocated, so caller needs to free it */
676 struct pollfd *
677 socksetup(int af, int options, const char *port, int *nfds)
678 {
679 	struct sockaddr_un un;
680 	struct addrinfo hints, *res, *r;
681 	int error, s, blidx = 0, n;
682 	struct pollfd *socks, *newsocks;
683 	const int on = 1;
684 
685 	*nfds = 0;
686 
687 	socks = malloc(1 * sizeof(socks[0]));
688 	if (!socks) {
689 		syslog(LOG_ERR, "couldn't allocate memory for sockets");
690 		mcleanup(0);
691 	}
692 
693 	s = socket(AF_LOCAL, SOCK_STREAM, 0);
694 	if (s < 0) {
695 		syslog(LOG_ERR, "socket(): %m");
696 		exit(1);
697 	}
698 	memset(&un, 0, sizeof(un));
699 	un.sun_family = AF_LOCAL;
700 	strncpy(un.sun_path, _PATH_SOCKETNAME, sizeof(un.sun_path) - 1);
701 	un.sun_len = SUN_LEN(&un);
702 	(void)umask(07);
703 	(void)unlink(_PATH_SOCKETNAME);
704 	if (bind(s, (struct sockaddr *)&un, un.sun_len) < 0) {
705 		syslog(LOG_ERR, "bind(): %m");
706 		exit(1);
707 	}
708 	(void)umask(0);
709 	listen(s, 5);
710 	socks[*nfds].fd = s;
711 	socks[*nfds].events = POLLIN;
712 	(*nfds)++;
713 
714 	if (sflag && !blist_addrs)
715 		return (socks);
716 
717 	do {
718 		memset(&hints, 0, sizeof(hints));
719 		hints.ai_flags = AI_PASSIVE;
720 		hints.ai_family = af;
721 		hints.ai_socktype = SOCK_STREAM;
722 		error = getaddrinfo((blist_addrs == 0) ? NULL : blist[blidx],
723 		    port ? port : "printer", &hints, &res);
724 		if (error) {
725 			if (blist_addrs)
726 				syslog(LOG_ERR, "%s: %s", blist[blidx],
727 				    gai_strerror(error));
728 			else
729 				syslog(LOG_ERR, "%s", gai_strerror(error));
730 			mcleanup(0);
731 		}
732 
733 		/* Count max number of sockets we may open */
734 		for (r = res, n = 0; r; r = r->ai_next, n++)
735 			;
736 		newsocks = realloc(socks, (*nfds + n) * sizeof(socks[0]));
737 		if (!newsocks) {
738 			syslog(LOG_ERR, "couldn't allocate memory for sockets");
739 			mcleanup(0);
740 		}
741 		socks = newsocks;
742 
743 		for (r = res; r; r = r->ai_next) {
744 			s = socket(r->ai_family, r->ai_socktype,
745 			    r->ai_protocol);
746 			if (s < 0) {
747 				syslog(LOG_DEBUG, "socket(): %m");
748 				continue;
749 			}
750 			if (options & SO_DEBUG)
751 				if (setsockopt(s, SOL_SOCKET, SO_DEBUG,
752 					       &on, sizeof(on)) < 0) {
753 					syslog(LOG_ERR,
754 					       "setsockopt (SO_DEBUG): %m");
755 					close(s);
756 					continue;
757 				}
758 			if (setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &on,
759 			    sizeof(on)) < 0) {
760 				syslog(LOG_ERR,
761 				    "setsockopt (SO_REUSEPORT): %m");
762 				close(s);
763 				continue;
764 			}
765 			if (r->ai_family == AF_INET6 && setsockopt(s,
766 			    IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0) {
767 				syslog(LOG_ERR,
768 				    "setsockopt (IPV6_V6ONLY): %m");
769 				close(s);
770 				continue;
771 			}
772 			if (bind(s, r->ai_addr, r->ai_addrlen) < 0) {
773 				syslog(LOG_DEBUG, "bind(): %m");
774 				close(s);
775 				continue;
776 			}
777 			listen(s, 5);
778 			socks[*nfds].fd = s;
779 			socks[*nfds].events = POLLIN;
780 			(*nfds)++;
781 		}
782 
783 		if (res)
784 			freeaddrinfo(res);
785 	} while (++blidx < blist_addrs);
786 
787 	return (socks);
788 }
789