summaryrefslogtreecommitdiff
path: root/usr.sbin/lpr/lpd/lpd.c
blob: e731fda086bf483a405a31c351414d91eb2fe450 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
/*	$OpenBSD: lpd.c,v 1.33 2002/06/08 01:53:43 millert Exp $ */
/*	$NetBSD: lpd.c,v 1.33 2002/01/21 14:42:29 wiz Exp $	*/

/*
 * Copyright (c) 1983, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1983, 1993, 1994\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
#if 0
static const char sccsid[] = "@(#)lpd.c	8.7 (Berkeley) 5/10/95";
#else
static const char rcsid[] = "$OpenBSD: lpd.c,v 1.33 2002/06/08 01:53:43 millert Exp $";
#endif
#endif /* not lint */

/*
 * lpd -- line printer daemon.
 *
 * Listen for a connection and perform the requested operation.
 * Operations are:
 *	\1printer\n
 *		check the queue for jobs and print any found.
 *	\2printer\n
 *		receive a job from another machine and queue it.
 *	\3printer [users ...] [jobs ...]\n
 *		return the current state of the queue (short form).
 *	\4printer [users ...] [jobs ...]\n
 *		return the current state of the queue (long form).
 *	\5printer person [users ...] [jobs ...]\n
 *		remove jobs from the queue.
 *
 * Strategy to maintain protected spooling area:
 *	1. Spooling area is writable only by root and the group daemon.
 *	2. Files in spooling area are owned by user daemon, group daemon,
 *	   and are mode 660.
 *	3. lpd runs as root but spends most of its time with its effective
 *	   uid and gid set to the uid/gid specified in the passwd entry for
 *	   DEFUID (1, aka daemon).
 *	4. lpr runs setuid daemon and setgrp daemon; it opens
 *	   files to be printed with its real uid/gid and writes to
 *	   the spool dir with its effective uid/gid (i.e. daemon).
 *	5. lpc, lpr and lprm run setgrp daemon.
 *
 * Users can't touch the spool w/o the help of one of the lp* programs.
 */

#include <sys/param.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include <ctype.h>
#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>

#include "lp.h"
#include "lp.local.h"
#include "pathnames.h"
#include "extern.h"

#define	LPD_NOPORTCHK	0001		/* skip reserved-port check */

int	lflag;				/* log requests flag */
int	rflag;				/* allow 'of' for remote printers */
int	sflag;				/* secure (no inet) flag */
int	from_remote;			/* from remote socket */
char	**blist;			/* list of addresses to bind(2) to */
int	blist_size;
int	blist_addrs;

volatile sig_atomic_t child_count;	/* number of kids forked */

static void		reapchild(int);
static void		mcleanup(int);
static void		doit(void);
static void		startup(void);
static void		chkhost(struct sockaddr *, int);
static int		ckqueue(char *);
static __dead void	usage(void);
static int		*socksetup(int, int, const char *);

extern int		__ivaliduser_sa(FILE *, struct sockaddr *, socklen_t,
			    const char *, const char *);

/* unused, needed for lpc */
volatile sig_atomic_t gotintr;

int
main(int argc, char **argv)
{
	fd_set defreadfds;
	struct passwd *pw;
	struct sockaddr_un un, fromunix;
	struct sockaddr_storage frominet;
	sigset_t mask, omask;
	int lfd, i, f, funix, *finet;
	int options, check_options, maxfd;
	long l;
	long child_max = 32;	/* more then enough to hose the system */
	struct servent *sp;
	const char *port = "printer";
	char *cp;

	if (geteuid() != 0)
		errx(1, "must run as root");

	/*
	 * We want to run with euid of daemon most of the time.
	 */
	if ((pw = getpwuid(DEFUID)) == NULL)
		errx(1, "daemon uid (%d) not in password file", DEFUID);
	real_uid = pw->pw_uid;
	real_gid = pw->pw_gid;
	effective_uid = 0;
	effective_gid = getegid();
	PRIV_END;	/* run as daemon for most things */

	check_options = LPD_NOPORTCHK;		/* XXX - lp* not setuid root */
	options = 0;
	gethostname(host, sizeof(host));

	while ((i = getopt(argc, argv, "b:cdln:rsw:W")) != -1) {
		switch (i) {
		case 'b':
			if (blist_addrs >= blist_size) {
				blist_size += sizeof(char *) * 4;
				if (blist == NULL)
					blist = malloc(blist_size);
				else
					blist = realloc(blist, blist_size);
				if (blist == NULL)
					err(1, "cant allocate bind addr list");
			}
			blist[blist_addrs] = strdup(optarg);
			if (blist[blist_addrs++] == NULL)
				err(1, NULL);
			break;
		case 'd':
			options |= SO_DEBUG;
			break;
		case 'l':
			lflag++;
			break;
		case 'n':
			child_max = strtol(optarg, &cp, 10);
			if (*cp != '\0' || child_max < 0 || child_max > 1024)
				errx(1, "invalid number of children: %s",
				    optarg);
			break;
		case 'r':
			rflag++;
			break;
		case 's':
			sflag++;
			break;
		case 'w':
			l = strtol(optarg, &cp, 10);
			if (*cp != '\0' || l < 0 || l >= INT_MAX)
				errx(1, "wait time must be postive integer: %s",
				    optarg);
			wait_time = (u_int)l;
			if (wait_time < 30)
				warnx("warning: wait time less than 30 seconds");
			break;
		case 'W':
			/*
			 * Allow connections coming from a non-reserved port.
			 * (done by some lpr-implementations for MS-Windows)
			 */
			check_options |= LPD_NOPORTCHK;
			break;
		default:
			usage();
			break;
		}
	}
	argc -= optind;
	argv += optind;

	switch (argc) {
	case 1:
		port = argv[0];
		l = strtol(port, &cp, 10);
		if (*cp != '\0' || l <= 0 || l > USHRT_MAX)
			errx(1, "port # %s is invalid", port);
		break;
	case 0:
		sp = getservbyname(port, "tcp");
		if (sp == NULL)
			errx(1, "%s/tcp: unknown service", port);
		break;
	default:
		usage();
	}

#ifndef DEBUG
	/*
	 * Set up standard environment by detaching from the parent.
	 */
	daemon(0, 0);
#endif

	openlog("lpd", LOG_PID, LOG_LPR);
	syslog(LOG_INFO, "restarted");
	(void)umask(0);
	PRIV_START;
	lfd = open(_PATH_MASTERLOCK, O_WRONLY|O_CREAT|O_EXLOCK|O_NONBLOCK, 0644);
	PRIV_END;
	if (lfd < 0) {
		if (errno == EWOULDBLOCK)	/* active daemon present */
			exit(0);
		syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK);
		exit(1);
	}
	ftruncate(lfd, 0);
	/*
	 * write process id for others to know
	 */
	(void)snprintf(line, sizeof(line), "%u\n", getpid());
	f = strlen(line);
	if (write(lfd, line, f) != f) {
		syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK);
		exit(1);
	}
	signal(SIGCHLD, reapchild);
	/*
	 * Restart all the printers.
	 */
	startup();
	PRIV_START;
	(void)unlink(_PATH_SOCKETNAME);
	PRIV_END;
	funix = socket(AF_LOCAL, SOCK_STREAM, 0);
	if (funix < 0) {
		syslog(LOG_ERR, "socket: %m");
		exit(1);
	}

	sigemptyset(&mask);
	sigaddset(&mask, SIGHUP);
	sigaddset(&mask, SIGINT);
	sigaddset(&mask, SIGQUIT);
	sigaddset(&mask, SIGTERM);
	sigprocmask(SIG_BLOCK, &mask, &omask);

	(void)umask(07);
	signal(SIGHUP, mcleanup);
	signal(SIGINT, mcleanup);
	signal(SIGQUIT, mcleanup);
	signal(SIGTERM, mcleanup);
	memset(&un, 0, sizeof(un));
	un.sun_family = AF_LOCAL;
	strlcpy(un.sun_path, _PATH_SOCKETNAME, sizeof(un.sun_path));
#ifndef SUN_LEN
#define SUN_LEN(unp) (strlen((unp)->sun_path) + 2)
#endif
	PRIV_START;
	if (bind(funix, (struct sockaddr *)&un, SUN_LEN(&un)) < 0) {
		syslog(LOG_ERR, "ubind: %m");
		exit(1);
	}
	PRIV_END;
	(void)umask(0);
	sigprocmask(SIG_SETMASK, &omask, NULL);
	FD_ZERO(&defreadfds);
	FD_SET(funix, &defreadfds);
	listen(funix, 5);
	if (!sflag || blist_addrs)
		finet = socksetup(PF_UNSPEC, options, port);
	else
		finet = NULL;	/* pretend we couldn't open TCP socket. */

	if (blist != NULL) {
		for (i = 0; i < blist_addrs; i++)
			free(blist[i]);
		free(blist);
	}

	maxfd = funix;
	if (finet) {
		for (i = 1; i <= *finet; i++) {
			FD_SET(finet[i], &defreadfds);
			listen(finet[i], 5);
			if (finet[i] > maxfd)
				maxfd = finet[i];
		}
	}
	/*
	 * Main loop: accept, do a request, continue.
	 */
	memset(&frominet, 0, sizeof(frominet));
	memset(&fromunix, 0, sizeof(fromunix));
	for (;;) {
		int domain, nfds, s, fromlen;
		fd_set readfds;
		short sleeptime = 10;	/* overflows in about 2 hours */

		while (child_max < child_count) {
			syslog(LOG_WARNING,
			    "too many children, sleeping for %d seconds",
			    sleeptime);
			sleep(sleeptime);
			sleeptime <<= 1;
			if (sleeptime < 0) {
				syslog(LOG_CRIT, "sleeptime overflowed! help!");
				sleeptime = 10;
			}
		}

		FD_COPY(&defreadfds, &readfds);
		nfds = select(maxfd + 1, &readfds, NULL, NULL, NULL);
		if (nfds <= 0) {
			if (nfds < 0 && errno != EINTR)
				syslog(LOG_WARNING, "select: %m");
			continue;
		}
		if (FD_ISSET(funix, &readfds)) {
			domain = AF_LOCAL;
			fromlen = sizeof(fromunix);
			s = accept(funix,
			    (struct sockaddr *)&fromunix, &fromlen);
		} else {
			domain = AF_INET;
			s = -1;
			for (i = 1; i <= *finet; i++)
				if (FD_ISSET(finet[i], &readfds)) {
					in_port_t port;

					fromlen = sizeof(frominet);
					s = accept(finet[i],
					    (struct sockaddr *)&frominet,
					    &fromlen);
					switch (frominet.ss_family) {
					case AF_INET:
						port = ((struct sockaddr_in *)
						    &frominet)->sin_port;
						break;
					case AF_INET6:
						port = ((struct sockaddr_in6 *)
						    &frominet)->sin6_port;
						break;
					default:
						port = 0;
					}
					/* check for ftp bounce attack */
					if (port == htons(20)) {
						close(s);
						continue;
					}
				}
		}
		if (s < 0) {
			if (errno != EINTR)
				syslog(LOG_WARNING, "accept: %m");
			continue;
		}

		switch (fork()) {
		case 0:
			signal(SIGCHLD, SIG_DFL);
			signal(SIGHUP, SIG_IGN);
			signal(SIGINT, SIG_IGN);
			signal(SIGQUIT, SIG_IGN);
			signal(SIGTERM, SIG_IGN);
			(void)close(funix);
			if (!sflag && finet)
				for (i = 1; i <= *finet; i++)
					(void)close(finet[i]);
			if (s != STDOUT_FILENO) {
				dup2(s, STDOUT_FILENO);
				(void)close(s);
			}
			if (domain == AF_INET) {
				/* for both AF_INET and AF_INET6 */
				from_remote = 1;
				chkhost((struct sockaddr *)&frominet, check_options);
			} else
				from_remote = 0;
			doit();
			exit(0);
		case -1:
			syslog(LOG_WARNING, "fork: %m, sleeping for 10 seconds...");
			sleep(10);
			continue;
		default:
			child_count++;
		}
		(void)close(s);
	}
}

static void
reapchild(int signo)
{
	int save_errno = errno;
	int status;

	while (waitpid((pid_t)-1, &status, WNOHANG) > 0)
		child_count--;
	errno = save_errno;
}

static void
mcleanup(int signo)
{
	struct syslog_data sdata = SYSLOG_DATA_INIT;

	if (lflag)
		syslog_r(LOG_INFO, &sdata, "exiting");
	PRIV_START;
	unlink(_PATH_SOCKETNAME);
	unlink(_PATH_MASTERLOCK);
	_exit(0);
}

/*
 * Stuff for handling job specifications
 */
char	*user[MAXUSERS];	/* users to process */
int	users;			/* # of users in user array */
int	requ[MAXREQUESTS];	/* job number of spool entries */
int	requests;		/* # of spool requests */
char	*person;		/* name of person doing lprm */

char	fromb[NI_MAXHOST];	/* buffer for client's machine name */
char	cbuf[BUFSIZ];		/* command line buffer */
char	*cmdnames[] = {
	"null",
	"printjob",
	"recvjob",
	"displayq short",
	"displayq long",
	"rmjob"
};

static void
doit(void)
{
	char *cp;
	int n;

	for (;;) {
		cp = cbuf;
		do {
			if (cp >= &cbuf[sizeof(cbuf) - 1])
				fatal("Command line too long");
			if ((n = read(STDOUT_FILENO, cp, 1)) != 1) {
				if (n < 0)
					fatal("Lost connection");
				return;
			}
		} while (*cp++ != '\n');
		*--cp = '\0';
		cp = cbuf;
		if (lflag) {
			if (*cp >= '\1' && *cp <= '\5') {
				syslog(LOG_INFO, "%s requests %s %s",
					from, cmdnames[(int)*cp], cp+1);
				setproctitle("serving %s: %s %s", from,
				    cmdnames[(int)*cp], cp+1);
			} else
				syslog(LOG_INFO, "bad request (%d) from %s",
					*cp, from);
		}
		switch (*cp++) {
		case '\1':	/* check the queue and print any jobs there */
			printer = cp;
			if (*printer == '\0')
				printer = DEFLP;
			printjob();
			break;
		case '\2':	/* receive files to be queued */
			if (!from_remote) {
				syslog(LOG_INFO, "illegal request (%d)", *cp);
				exit(1);
			}
			printer = cp;
			if (*printer == '\0')
				printer = DEFLP;
			recvjob();
			break;
		case '\3':	/* display the queue (short form) */
		case '\4':	/* display the queue (long form) */
			printer = cp;
			if (*printer == '\0')
				printer = DEFLP;
			while (*cp) {
				if (*cp != ' ') {
					cp++;
					continue;
				}
				*cp++ = '\0';
				while (isspace(*cp))
					cp++;
				if (*cp == '\0')
					break;
				if (isdigit(*cp)) {
					if (requests >= MAXREQUESTS)
						fatal("Too many requests");
					requ[requests++] = atoi(cp);
				} else {
					if (users >= MAXUSERS)
						fatal("Too many users");
					user[users++] = cp;
				}
			}
			displayq(cbuf[0] - '\3');
			exit(0);
		case '\5':	/* remove a job from the queue */
			if (!from_remote) {
				syslog(LOG_INFO, "illegal request (%d)", *cp);
				exit(1);
			}
			printer = cp;
			if (*printer == '\0')
				printer = DEFLP;
			while (*cp && *cp != ' ')
				cp++;
			if (!*cp)
				break;
			*cp++ = '\0';
			person = cp;
			while (*cp) {
				if (*cp != ' ') {
					cp++;
					continue;
				}
				*cp++ = '\0';
				while (isspace(*cp))
					cp++;
				if (*cp == '\0')
					break;
				if (isdigit(*cp)) {
					if (requests >= MAXREQUESTS)
						fatal("Too many requests");
					requ[requests++] = atoi(cp);
				} else {
					if (users >= MAXUSERS)
						fatal("Too many users");
					user[users++] = cp;
				}
			}
			rmjob();
			break;
		}
		fatal("Illegal service request");
	}
}

/*
 * Make a pass through the printcap database and start printing any
 * files left from the last time the machine went down.
 */
static void
startup(void)
{
	char *buf, *cp;

	/*
	 * Restart the daemons.
	 */
	while (cgetnext(&buf, printcapdb) > 0) {
		if (ckqueue(buf) <= 0) {
			free(buf);
			continue;	/* no work to do for this printer */
		}
		for (cp = buf; *cp; cp++)
			if (*cp == '|' || *cp == ':') {
				*cp = '\0';
				break;
			}
		if (lflag)
			syslog(LOG_INFO, "work for %s", buf);
		switch (fork()) {
		case -1:
			syslog(LOG_WARNING, "startup: cannot fork");
			mcleanup(0);
			/* NOTREACHED */
		case 0:
			printer = buf;
			setproctitle("working on printer %s", printer);
			cgetclose();
			printjob();
			/* NOTREACHED */
		default:
			child_count++;
			free(buf);
		}
	}
}

/*
 * Make sure there's some work to do before forking off a child
 * XXX - could be common w/ lpq
 */
static int
ckqueue(char *cap)
{
	struct dirent *d;
	DIR *dirp;
	char *spooldir;

	if (cgetstr(cap, "sd", &spooldir) == -1)
		spooldir = _PATH_DEFSPOOL;
	dirp = opendir(spooldir);
	if (dirp == NULL)
		return (-1);
	while ((d = readdir(dirp)) != NULL) {
		if (d->d_name[0] == 'c' && d->d_name[1] == 'f') {
			closedir(dirp);
			return (1);		/* found a cf file */
		}
	}
	closedir(dirp);
	return (0);
}

#define DUMMY ":nobody::"

/*
 * Check to see if the from host has access to the line printer.
 */
static void
chkhost(struct sockaddr *f, int check_opts)
{
	struct addrinfo hints, *res, *r;
	FILE *hostf;
	int first = 1;
	int good = 0;
	char host[NI_MAXHOST], ip[NI_MAXHOST];
	char serv[NI_MAXSERV];
	int error;

	error = getnameinfo(f, f->sa_len, NULL, 0, serv, sizeof(serv),
	    NI_NUMERICSERV);
	if (error)
		fatal("Malformed from address");

	if (!(check_opts & LPD_NOPORTCHK) &&
	    atoi(serv) >= IPPORT_RESERVED)
		fatal("Connect from invalid port (%s)", serv);

	/* Need real hostname for temporary filenames */
	error = getnameinfo(f, f->sa_len, host, sizeof(host), NULL, 0,
	    NI_NAMEREQD);
	if (error) {
		error = getnameinfo(f, f->sa_len, host, sizeof(host), NULL, 0,
		    NI_NUMERICHOST);
		if (error)
			fatal("Host name for your address unknown");
		else
			fatal("Host name for your address (%s) unknown", host);
	}

	(void)strlcpy(fromb, host, sizeof(fromb));
	from = fromb;

	/* need address in stringform for comparison (no DNS lookup here) */
	error = getnameinfo(f, f->sa_len, host, sizeof(host), NULL, 0,
	    NI_NUMERICHOST);
	if (error)
		fatal("Cannot print address");

	/* Check for spoof, ala rlogind */
	memset(&hints, 0, sizeof(hints));
	hints.ai_family = PF_UNSPEC;
	hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
	error = getaddrinfo(fromb, NULL, &hints, &res);
	if (error) {
		fatal("hostname for your address (%s) unknown: %s", host,
		    gai_strerror(error));
	}
	for (good = 0, r = res; good == 0 && r; r = r->ai_next) {
		error = getnameinfo(r->ai_addr, r->ai_addrlen, ip, sizeof(ip),
		    NULL, 0, NI_NUMERICHOST);
		if (!error && !strcmp(host, ip))
			good = 1;
	}
	if (res)
		freeaddrinfo(res);
	if (good == 0)
		fatal("address for your hostname (%s) not matched", host);
	setproctitle("serving %s", from);
	PRIV_START;
	hostf = fopen(_PATH_HOSTSEQUIV, "r");
	PRIV_END;
again:
	if (hostf) {
		if (__ivaliduser_sa(hostf, f, f->sa_len, DUMMY, DUMMY) == 0) {
			(void)fclose(hostf);
			return;
		}
		(void)fclose(hostf);
	}
	if (first == 1) {
		first = 0;
		PRIV_START;
		hostf = fopen(_PATH_HOSTSLPD, "r");
		PRIV_END;
		goto again;
	}
	fatal("Your host does not have line printer access");
	/*NOTREACHED*/
}

static __dead void
usage(void)
{
	extern char *__progname;

	fprintf(stderr, "usage: %s [-dlrsW] [-b bind-address] [-n maxchild] "
	    "[-w maxwait] [port]\n", __progname);
	exit(1);
}

/*
 * Setup server socket for specified address family.
 * If af is PF_UNSPEC more than one socket may be returned.
 * The returned list is dynamically allocated, so the caller needs to free it.
 */
int *
socksetup(int af, int options, const char *port)
{
	struct addrinfo hints, *res, *r;
	int error, maxs = 0, *s, *socks = NULL, blidx = 0;
	const int on = 1;

	do {
		memset(&hints, 0, sizeof(hints));
		hints.ai_flags = AI_PASSIVE;
		hints.ai_family = af;
		hints.ai_socktype = SOCK_STREAM;
		error = getaddrinfo((blist_addrs == 0) ? NULL : blist[blidx],
		    port ? port : "printer", &hints, &res);
		if (error) {
			if (blist_addrs)
				syslog(LOG_ERR, "%s: %s", blist[blidx],
				    gai_strerror(error));
			else
				syslog(LOG_ERR, "%s", gai_strerror(error));
			mcleanup(0);
		}

		/* Count max number of sockets we may open */
		for (r = res; r; r = r->ai_next, maxs++)
			;
		if (socks == NULL) {
			socks = malloc((maxs + 1) * sizeof(int));
			if (socks)
				*socks = 0; /* num of sockets ctr at start */
		} else
			socks = realloc(socks, (maxs + 1) * sizeof(int));
		if (!socks) {
			syslog(LOG_ERR, "couldn't allocate memory for sockets");
			mcleanup(0);
		}

		s = socks + *socks + 1;
		for (r = res; r; r = r->ai_next) {
			*s = socket(r->ai_family, r->ai_socktype,
			            r->ai_protocol);
			if (*s < 0) {
				syslog(LOG_DEBUG, "socket(): %m");
				continue;
			}
			if (options & SO_DEBUG)
				if (setsockopt(*s, SOL_SOCKET, SO_DEBUG,
					       &on, sizeof(on)) < 0) {
					syslog(LOG_ERR,
					       "setsockopt (SO_DEBUG): %m");
					close (*s);
					continue;
				}
			PRIV_START;
			error = bind(*s, r->ai_addr, r->ai_addrlen);
			PRIV_END;
			if (error < 0) {
				syslog(LOG_DEBUG, "bind(): %m");
				close (*s);
				continue;
			}
			*socks = *socks + 1;
			s++;
		}

		if (res)
			freeaddrinfo(res);
	} while (++blidx < blist_addrs);

	if (socks == NULL || *socks == 0) {
		syslog(LOG_ERR, "Couldn't bind to any socket");
		if (socks != NULL)
			free(socks);
		mcleanup(0);
	}
	return(socks);
}