xref: /netbsd-src/usr.sbin/lpr/lpd/lpd.c (revision 211e5fcd48a73970460a7d47cb5b4fa5a583f1fb)
1 /*	$NetBSD: lpd.c,v 1.60 2023/04/26 18:25:02 kre 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\
37  The Regents of the University of California.  All rights reserved.");
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 1.60 2023/04/26 18:25:02 kre 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 static void		reapchild(int);
129 __dead static void	mcleanup(int);
130 static void		doit(void);
131 static void		startup(void);
132 static void		chkhost(struct sockaddr *, int);
133 __dead static void	usage(void);
134 static struct pollfd	*socksetup(int, int, const char *, int *);
135 static void		chkplushost(int, FILE *, char*);
136 
137 uid_t	uid, euid;
138 int child_count;
139 
140 #define LPD_NOPORTCHK	0001		/* skip reserved-port check */
141 
142 int
main(int argc,char ** argv)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 positive: %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_DFL);
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 /*
366  * If there was a forward/backward name resolution mismatch, check
367  * that there's a '+' entry in fhost.
368  */
369 
370 void
chkplushost(int good,FILE * fhost,char * hst)371 chkplushost(int good, FILE *fhost, char *hst)
372 {
373 	int c1, c2, c3;
374 
375 	if (good) {
376 		return;
377 	}
378 
379 	rewind(fhost);
380 	while (EOF != (c1 = fgetc(fhost))) {
381 		if (c1 == '+') {
382 			c2 = fgetc(fhost);
383 			if (c2 == ' ' || c2 == '\t' || c2 == '\n') {
384 				return;
385 			}
386 		}
387 		do {
388 			c3 = fgetc(fhost);
389 		} while (c3 != EOF && c3 != '\n');
390 	}
391 	fatal("address for your hostname (%s) not matched", hst);
392 }
393 
394 static void
reapchild(int signo)395 reapchild(int signo)
396 {
397 	int status;
398 
399 	while (wait3(&status, WNOHANG, 0) > 0)
400 		child_count--;
401 }
402 
403 static void
mcleanup(int signo)404 mcleanup(int signo)
405 {
406 	if (lflag)
407 		syslog(LOG_INFO, "exiting");
408 	unlink(_PATH_SOCKETNAME);
409 	exit(0);
410 }
411 
412 /*
413  * Stuff for handling job specifications
414  */
415 char	*user[MAXUSERS];	/* users to process */
416 int	users;			/* # of users in user array */
417 int	requ[MAXREQUESTS];	/* job number of spool entries */
418 int	requests;		/* # of spool requests */
419 char	*person;		/* name of person doing lprm */
420 
421 char	fromb[NI_MAXHOST];	/* buffer for client's machine name */
422 char	cbuf[BUFSIZ];		/* command line buffer */
423 const char *cmdnames[] = {
424 	"null",
425 	"printjob",
426 	"recvjob",
427 	"displayq short",
428 	"displayq long",
429 	"rmjob"
430 };
431 
432 static void
doit(void)433 doit(void)
434 {
435 	char *cp;
436 	int n;
437 
438 	for (;;) {
439 		cp = cbuf;
440 		do {
441 			if (cp >= &cbuf[sizeof(cbuf) - 1])
442 				fatal("Command line too long");
443 			if ((n = read(STDOUT_FILENO, cp, 1)) != 1) {
444 				if (n < 0)
445 					fatal("Lost connection");
446 				return;
447 			}
448 		} while (*cp++ != '\n');
449 		*--cp = '\0';
450 		cp = cbuf;
451 		if (lflag) {
452 			if (*cp >= '\1' && *cp <= '\5') {
453 				syslog(LOG_INFO, "%s requests %s %s",
454 					from, cmdnames[(int)*cp], cp+1);
455 				setproctitle("serving %s: %s %s", from,
456 				    cmdnames[(int)*cp], cp+1);
457 			}
458 			else
459 				syslog(LOG_INFO, "bad request (%d) from %s",
460 					*cp, from);
461 		}
462 		switch (*cp++) {
463 		case '\1':	/* check the queue and print any jobs there */
464 			printer = cp;
465 			if (*printer == '\0')
466 				printer = DEFLP;
467 			printjob();
468 			break;
469 		case '\2':	/* receive files to be queued */
470 			if (!from_remote) {
471 				syslog(LOG_INFO, "illegal request (%d)", *cp);
472 				exit(1);
473 			}
474 			printer = cp;
475 			if (*printer == '\0')
476 				printer = DEFLP;
477 			recvjob();
478 			break;
479 		case '\3':	/* display the queue (short form) */
480 		case '\4':	/* display the queue (long form) */
481 			printer = cp;
482 			if (*printer == '\0')
483 				printer = DEFLP;
484 			while (*cp) {
485 				if (*cp != ' ') {
486 					cp++;
487 					continue;
488 				}
489 				*cp++ = '\0';
490 				while (isspace((unsigned char)*cp))
491 					cp++;
492 				if (*cp == '\0')
493 					break;
494 				if (isdigit((unsigned char)*cp)) {
495 					if (requests >= MAXREQUESTS)
496 						fatal("Too many requests");
497 					requ[requests++] = atoi(cp);
498 				} else {
499 					if (users >= MAXUSERS)
500 						fatal("Too many users");
501 					user[users++] = cp;
502 				}
503 			}
504 			displayq(cbuf[0] - '\3');
505 			exit(0);
506 		case '\5':	/* remove a job from the queue */
507 			if (!from_remote) {
508 				syslog(LOG_INFO, "illegal request (%d)", *cp);
509 				exit(1);
510 			}
511 			printer = cp;
512 			if (*printer == '\0')
513 				printer = DEFLP;
514 			while (*cp && *cp != ' ')
515 				cp++;
516 			if (!*cp)
517 				break;
518 			*cp++ = '\0';
519 			person = cp;
520 			while (*cp) {
521 				if (*cp != ' ') {
522 					cp++;
523 					continue;
524 				}
525 				*cp++ = '\0';
526 				while (isspace((unsigned char)*cp))
527 					cp++;
528 				if (*cp == '\0')
529 					break;
530 				if (isdigit((unsigned char)*cp)) {
531 					if (requests >= MAXREQUESTS)
532 						fatal("Too many requests");
533 					requ[requests++] = atoi(cp);
534 				} else {
535 					if (users >= MAXUSERS)
536 						fatal("Too many users");
537 					user[users++] = cp;
538 				}
539 			}
540 			rmjob();
541 			break;
542 		}
543 		fatal("Illegal service request");
544 	}
545 }
546 
547 /*
548  * Make a pass through the printcap database and start printing any
549  * files left from the last time the machine went down.
550  */
551 static void
startup(void)552 startup(void)
553 {
554 	char *buf;
555 	char *cp;
556 
557 	/*
558 	 * Restart the daemons.
559 	 */
560 	while (cgetnext(&buf, printcapdb) > 0) {
561 		if (ckqueue(buf) <= 0) {
562 			free(buf);
563 			continue;	/* no work to do for this printer */
564 		}
565 		for (cp = buf; *cp; cp++)
566 			if (*cp == '|' || *cp == ':') {
567 				*cp = '\0';
568 				break;
569 			}
570 		if (lflag)
571 			syslog(LOG_INFO, "work for %s", buf);
572 		switch (fork()) {
573 		case -1:
574 			syslog(LOG_WARNING, "startup: cannot fork");
575 			mcleanup(0);
576 		case 0:
577 			printer = buf;
578 			setproctitle("working on printer %s", printer);
579 			cgetclose();
580 			printjob();
581 			/* NOTREACHED */
582 		default:
583 			child_count++;
584 			free(buf);
585 		}
586 	}
587 }
588 
589 #define DUMMY ":nobody::"
590 
591 /*
592  * Check to see if the from host has access to the line printer.
593  */
594 static void
chkhost(struct sockaddr * f,int check_opts)595 chkhost(struct sockaddr *f, int check_opts)
596 {
597 	struct addrinfo hints, *res, *r;
598 	FILE *hostf;
599 	int good = 0;
600 	char hst[NI_MAXHOST], ip[NI_MAXHOST];
601 	char serv[NI_MAXSERV];
602 	int error;
603 #ifdef LIBWRAP
604 	struct request_info req;
605 #endif
606 
607 	error = getnameinfo(f, f->sa_len, NULL, 0, serv, sizeof(serv),
608 			    NI_NUMERICSERV);
609 	if (error)
610 		fatal("Malformed from address: %s", gai_strerror(error));
611 
612          if (!(check_opts & LPD_NOPORTCHK) &&
613 	       atoi(serv) >= IPPORT_RESERVED)
614 		fatal("Connect from invalid port (%s)", serv);
615 
616 	/* Need real hostname for temporary filenames */
617 	error = getnameinfo(f, f->sa_len, hst, sizeof(hst), NULL, 0,
618 			    NI_NAMEREQD);
619 	if (error) {
620 		error = getnameinfo(f, f->sa_len, hst, sizeof(hst), NULL, 0,
621 				    NI_NUMERICHOST);
622 		if (error)
623 			fatal("Host name for your address unknown");
624 		else
625 			fatal("Host name for your address (%s) unknown", hst);
626 	}
627 
628 	(void)strlcpy(fromb, hst, sizeof(fromb));
629 	from = fromb;
630 
631 	/* need address in stringform for comparison (no DNS lookup here) */
632 	error = getnameinfo(f, f->sa_len, hst, sizeof(hst), NULL, 0,
633 			    NI_NUMERICHOST);
634 	if (error)
635 		fatal("Cannot print address");
636 
637 	/* Check for spoof, ala rlogind */
638 	good = 0;
639 	memset(&hints, 0, sizeof(hints));
640 	hints.ai_family = PF_UNSPEC;
641 	hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
642 	error = getaddrinfo(fromb, NULL, &hints, &res);
643 	if (!error) {
644 		for (r = res; good == 0 && r; r = r->ai_next) {
645 			error = getnameinfo(r->ai_addr, r->ai_addrlen,
646 				    ip, sizeof(ip), NULL, 0, NI_NUMERICHOST);
647 			if (!error && !strcmp(hst, ip))
648 				good = 1;
649 		}
650 		if (res)
651 			freeaddrinfo(res);
652 	}
653 
654 	/* complain about !good later in chkplushost if needed. */
655 
656 	setproctitle("serving %s", from);
657 
658 #ifdef LIBWRAP
659 	request_init(&req, RQ_DAEMON, "lpd", RQ_CLIENT_SIN, f,
660 	    RQ_FILE, STDOUT_FILENO, NULL);
661 	fromhost(&req);
662 	if (!hosts_access(&req))
663 		goto denied;
664 #endif
665 
666 	hostf = fopen(_PATH_HOSTSEQUIV, "r");
667 	if (hostf) {
668 		if (__ivaliduser_sa(hostf, f, f->sa_len, DUMMY, DUMMY) == 0) {
669 			chkplushost(good, hostf, hst);
670 			(void)fclose(hostf);
671 			return;
672 		}
673 		(void)fclose(hostf);
674 	}
675 	hostf = fopen(_PATH_HOSTSLPD, "r");
676 	if (hostf) {
677 		if (__ivaliduser_sa(hostf, f, f->sa_len, DUMMY, DUMMY) == 0) {
678 			chkplushost(good, hostf, hst);
679 			(void)fclose(hostf);
680 			return;
681 		}
682 		(void)fclose(hostf);
683 	}
684 #ifdef LIBWRAP
685   denied:
686 #endif
687 	fatal("Your host does not have line printer access");
688 	/*NOTREACHED*/
689 }
690 
691 
692 static void
usage(void)693 usage(void)
694 {
695 
696 	(void)fprintf(stderr,
697 	    "Usage: %s [-dlrsW] [-b bind-address] [-n maxchild] "
698 	    "[-w maxwait] [port]\n", getprogname());
699 	exit(1);
700 }
701 
702 /* setup server socket for specified address family */
703 /* if af is PF_UNSPEC more than one socket may be returned */
704 /* the returned list is dynamically allocated, so caller needs to free it */
705 struct pollfd *
socksetup(int af,int options,const char * port,int * nfds)706 socksetup(int af, int options, const char *port, int *nfds)
707 {
708 	struct sockaddr_un un;
709 	struct addrinfo hints, *res, *r;
710 	int error, s, blidx = 0, n;
711 	struct pollfd *socks, *newsocks;
712 	const int on = 1;
713 
714 	*nfds = 0;
715 
716 	socks = malloc(1 * sizeof(socks[0]));
717 	if (!socks) {
718 		syslog(LOG_ERR, "couldn't allocate memory for sockets");
719 		mcleanup(0);
720 	}
721 
722 	s = socket(AF_LOCAL, SOCK_STREAM, 0);
723 	if (s < 0) {
724 		syslog(LOG_ERR, "socket(): %m");
725 		exit(1);
726 	}
727 	memset(&un, 0, sizeof(un));
728 	un.sun_family = AF_LOCAL;
729 	strncpy(un.sun_path, _PATH_SOCKETNAME, sizeof(un.sun_path) - 1);
730 	un.sun_len = SUN_LEN(&un);
731 	(void)umask(07);
732 	(void)unlink(_PATH_SOCKETNAME);
733 	if (bind(s, (struct sockaddr *)&un, un.sun_len) < 0) {
734 		syslog(LOG_ERR, "bind(): %m");
735 		exit(1);
736 	}
737 	(void)umask(0);
738 	listen(s, 5);
739 	socks[*nfds].fd = s;
740 	socks[*nfds].events = POLLIN;
741 	(*nfds)++;
742 
743 	if (sflag && !blist_addrs)
744 		return (socks);
745 
746 	do {
747 		memset(&hints, 0, sizeof(hints));
748 		hints.ai_flags = AI_PASSIVE;
749 		hints.ai_family = af;
750 		hints.ai_socktype = SOCK_STREAM;
751 		error = getaddrinfo((blist_addrs == 0) ? NULL : blist[blidx],
752 		    port ? port : "printer", &hints, &res);
753 		if (error) {
754 			if (blist_addrs)
755 				syslog(LOG_ERR, "%s: %s", blist[blidx],
756 				    gai_strerror(error));
757 			else
758 				syslog(LOG_ERR, "%s", gai_strerror(error));
759 			mcleanup(0);
760 		}
761 
762 		/* Count max number of sockets we may open */
763 		for (r = res, n = 0; r; r = r->ai_next, n++)
764 			;
765 		newsocks = realloc(socks, (*nfds + n) * sizeof(socks[0]));
766 		if (!newsocks) {
767 			syslog(LOG_ERR, "couldn't allocate memory for sockets");
768 			mcleanup(0);
769 		}
770 		socks = newsocks;
771 
772 		for (r = res; r; r = r->ai_next) {
773 			s = socket(r->ai_family, r->ai_socktype,
774 			    r->ai_protocol);
775 			if (s < 0) {
776 				syslog(LOG_DEBUG, "socket(): %m");
777 				continue;
778 			}
779 			if (options & SO_DEBUG)
780 				if (setsockopt(s, SOL_SOCKET, SO_DEBUG,
781 					       &on, sizeof(on)) < 0) {
782 					syslog(LOG_ERR,
783 					       "setsockopt (SO_DEBUG): %m");
784 					close(s);
785 					continue;
786 				}
787 			if (setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &on,
788 			    sizeof(on)) < 0) {
789 				syslog(LOG_ERR,
790 				    "setsockopt (SO_REUSEPORT): %m");
791 				close(s);
792 				continue;
793 			}
794 			if (r->ai_family == AF_INET6 && setsockopt(s,
795 			    IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0) {
796 				syslog(LOG_ERR,
797 				    "setsockopt (IPV6_V6ONLY): %m");
798 				close(s);
799 				continue;
800 			}
801 			if (bind(s, r->ai_addr, r->ai_addrlen) < 0) {
802 				syslog(LOG_DEBUG, "bind(): %m");
803 				close(s);
804 				continue;
805 			}
806 			listen(s, 5);
807 			socks[*nfds].fd = s;
808 			socks[*nfds].events = POLLIN;
809 			(*nfds)++;
810 		}
811 
812 		if (res)
813 			freeaddrinfo(res);
814 	} while (++blidx < blist_addrs);
815 
816 	return (socks);
817 }
818