Style(9) cleanup.
[dragonfly.git] / usr.sbin / lpr / lpd / lpd.c
CommitLineData
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1/*
2 * Copyright (c) 1983, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
4 *
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by the University of
17 * California, Berkeley and its contributors.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
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33 *
34 * @(#) Copyright (c) 1983, 1993, 1994 The Regents of the University of California. All rights reserved.
35 * @(#)lpd.c 8.7 (Berkeley) 5/10/95
36 * $FreeBSD: src/usr.sbin/lpr/lpd/lpd.c,v 1.12.2.22 2002/06/30 04:09:11 gad Exp $
be6b9a2e 37 * $DragonFly: src/usr.sbin/lpr/lpd/lpd.c,v 1.4 2004/03/22 22:32:50 cpressey Exp $
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38 */
39
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40/*
41 * lpd -- line printer daemon.
42 *
43 * Listen for a connection and perform the requested operation.
44 * Operations are:
45 * \1printer\n
46 * check the queue for jobs and print any found.
47 * \2printer\n
48 * receive a job from another machine and queue it.
49 * \3printer [users ...] [jobs ...]\n
50 * return the current state of the queue (short form).
51 * \4printer [users ...] [jobs ...]\n
52 * return the current state of the queue (long form).
53 * \5printer person [users ...] [jobs ...]\n
54 * remove jobs from the queue.
55 *
56 * Strategy to maintain protected spooling area:
57 * 1. Spooling area is writable only by daemon and spooling group
58 * 2. lpr runs setuid root and setgrp spooling group; it uses
59 * root to access any file it wants (verifying things before
60 * with an access call) and group id to know how it should
61 * set up ownership of files in the spooling area.
62 * 3. Files in spooling area are owned by root, group spooling
63 * group, with mode 660.
64 * 4. lpd, lpq and lprm run setuid daemon and setgrp spooling group to
65 * access files and printer. Users can't get to anything
66 * w/o help of lpq and lprm programs.
67 */
68
69#include <sys/param.h>
70#include <sys/wait.h>
71#include <sys/types.h>
72#include <sys/socket.h>
73#include <sys/un.h>
74#include <sys/stat.h>
75#include <sys/file.h>
76#include <netinet/in.h>
77#include <arpa/inet.h>
78
79#include <netdb.h>
80#include <unistd.h>
81#include <syslog.h>
82#include <signal.h>
83#include <err.h>
84#include <errno.h>
85#include <fcntl.h>
86#include <dirent.h>
87#include <stdio.h>
88#include <stdlib.h>
89#include <string.h>
90#include <sysexits.h>
91#include <ctype.h>
92#include "lp.h"
93#include "lp.local.h"
94#include "pathnames.h"
95#include "extern.h"
96
97int lflag; /* log requests flag */
98int sflag; /* no incoming port flag */
99int from_remote; /* from remote socket */
100
101int main(int argc, char **_argv);
102static void reapchild(int _signo);
103static void mcleanup(int _signo);
104static void doit(void);
105static void startup(void);
106static void chkhost(struct sockaddr *_f, int _ch_opts);
107static int ckqueue(struct printer *_pp);
108static void fhosterr(int _ch_opts, char *_sysmsg, char *_usermsg);
109static int *socksetup(int _af, int _debuglvl);
110static void usage(void);
111
112/* XXX from libc/net/rcmd.c */
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113extern int __ivaliduser_sa(FILE *, struct sockaddr *, socklen_t,
114 const char *, const char *);
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115
116uid_t uid, euid;
117
118#define LPD_NOPORTCHK 0001 /* skip reserved-port check */
119#define LPD_LOGCONNERR 0002 /* (sys)log connection errors */
120#define LPD_ADDFROMLINE 0004 /* just used for fhosterr() */
121
122int
123main(int argc, char **argv)
124{
125 int ch_options, errs, f, funix, *finet, i, lfd, socket_debug;
126 fd_set defreadfds;
127 struct sockaddr_un un, fromunix;
128 struct sockaddr_storage frominet;
129 socklen_t fromlen;
130 sigset_t omask, nmask;
131 struct servent *sp, serv;
132 int inet_flag = 0, inet6_flag = 0;
133
134 euid = geteuid(); /* these shouldn't be different */
135 uid = getuid();
136
137 ch_options = 0;
138 socket_debug = 0;
139 gethostname(local_host, sizeof(local_host));
140
141 progname = "lpd";
142
143 if (euid != 0)
144 errx(EX_NOPERM,"must run as root");
145
146 errs = 0;
147 while ((i = getopt(argc, argv, "cdlpswW46")) != -1)
148 switch (i) {
149 case 'c':
150 /* log all kinds of connection-errors to syslog */
151 ch_options |= LPD_LOGCONNERR;
152 break;
153 case 'd':
154 socket_debug++;
155 break;
156 case 'l':
157 lflag++;
158 break;
159 case 'p': /* letter initially used for -s */
160 /*
161 * This will probably be removed with 5.0-release.
162 */
163 /* FALLTHROUGH */
164 case 's': /* secure (no inet) */
165 sflag++;
166 break;
167 case 'w': /* netbsd uses -w for maxwait */
168 /*
169 * This will be removed after the release of 4.4, as
170 * it conflicts with -w in netbsd's lpd. For now it
171 * is just a warning, so we won't suddenly break lpd
172 * for anyone who is currently using the option.
173 */
174 syslog(LOG_WARNING,
175 "NOTE: the -w option has been renamed -W");
176 syslog(LOG_WARNING,
177 "NOTE: please change your lpd config to use -W");
178 /* FALLTHROUGH */
179 case 'W':
180 /* allow connections coming from a non-reserved port */
181 /* (done by some lpr-implementations for MS-Windows) */
182 ch_options |= LPD_NOPORTCHK;
183 break;
184 case '4':
185 family = PF_INET;
186 inet_flag++;
187 break;
188 case '6':
189#ifdef INET6
190 family = PF_INET6;
191 inet6_flag++;
192#else
193 errx(EX_USAGE, "lpd compiled sans INET6 (IPv6 support)");
194#endif
195 break;
196 /*
197 * The following options are not in FreeBSD (yet?), but are
198 * listed here to "reserve" them, because the option-letters
199 * are used by either NetBSD or OpenBSD (as of July 2001).
200 */
201 case 'b': /* set bind-addr */
202 case 'n': /* set max num of children */
203 case 'r': /* allow 'of' for remote ptrs */
204 /* ...[not needed in freebsd] */
205 /* FALLTHROUGH */
206 default:
207 errs++;
208 }
209 if (inet_flag && inet6_flag)
210 family = PF_UNSPEC;
211 argc -= optind;
212 argv += optind;
213 if (errs)
214 usage();
215
216 if (argc == 1) {
217 if ((i = atoi(argv[0])) == 0)
218 usage();
219 if (i < 0 || i > USHRT_MAX)
220 errx(EX_USAGE, "port # %d is invalid", i);
221
222 serv.s_port = htons(i);
223 sp = &serv;
224 argc--;
225 } else {
226 sp = getservbyname("printer", "tcp");
227 if (sp == NULL)
228 errx(EX_OSFILE, "printer/tcp: unknown service");
229 }
230
231 if (argc != 0)
232 usage();
233
234 /*
235 * We run chkprintcap right away to catch any errors and blat them
236 * to stderr while we still have it open, rather than sending them
237 * to syslog and leaving the user wondering why lpd started and
238 * then stopped. There should probably be a command-line flag to
239 * ignore errors from chkprintcap.
240 */
241 {
242 pid_t pid;
243 int status;
244 pid = fork();
245 if (pid < 0) {
246 err(EX_OSERR, "cannot fork");
247 } else if (pid == 0) { /* child */
248 execl(_PATH_CHKPRINTCAP, _PATH_CHKPRINTCAP, (char *)0);
249 err(EX_OSERR, "cannot execute %s", _PATH_CHKPRINTCAP);
250 }
251 if (waitpid(pid, &status, 0) < 0) {
252 err(EX_OSERR, "cannot wait");
253 }
254 if (WIFEXITED(status) && WEXITSTATUS(status) != 0)
255 errx(EX_OSFILE, "%d errors in printcap file, exiting",
256 WEXITSTATUS(status));
257 }
258
259#ifndef DEBUG
260 /*
261 * Set up standard environment by detaching from the parent.
262 */
263 daemon(0, 0);
264#endif
265
266 openlog("lpd", LOG_PID, LOG_LPR);
267 syslog(LOG_INFO, "lpd startup: logging=%d%s%s", lflag,
268 socket_debug ? " dbg" : "", sflag ? " net-secure" : "");
269 (void) umask(0);
270 /*
271 * NB: This depends on O_NONBLOCK semantics doing the right thing;
272 * i.e., applying only to the O_EXLOCK and not to the rest of the
273 * open/creation. As of 1997-12-02, this is the case for commonly-
274 * used filesystems. There are other places in this code which
275 * make the same assumption.
276 */
277 lfd = open(_PATH_MASTERLOCK, O_WRONLY|O_CREAT|O_EXLOCK|O_NONBLOCK,
278 LOCK_FILE_MODE);
279 if (lfd < 0) {
280 if (errno == EWOULDBLOCK) /* active daemon present */
281 exit(0);
282 syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK);
283 exit(1);
284 }
285 fcntl(lfd, F_SETFL, 0); /* turn off non-blocking mode */
286 ftruncate(lfd, 0);
287 /*
288 * write process id for others to know
289 */
290 sprintf(line, "%u\n", getpid());
291 f = strlen(line);
292 if (write(lfd, line, f) != f) {
293 syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK);
294 exit(1);
295 }
296 signal(SIGCHLD, reapchild);
297 /*
298 * Restart all the printers.
299 */
300 startup();
301 (void) unlink(_PATH_SOCKETNAME);
302 funix = socket(AF_UNIX, SOCK_STREAM, 0);
303 if (funix < 0) {
304 syslog(LOG_ERR, "socket: %m");
305 exit(1);
306 }
307
308 sigemptyset(&nmask);
309 sigaddset(&nmask, SIGHUP);
310 sigaddset(&nmask, SIGINT);
311 sigaddset(&nmask, SIGQUIT);
312 sigaddset(&nmask, SIGTERM);
313 sigprocmask(SIG_BLOCK, &nmask, &omask);
314
315 (void) umask(07);
316 signal(SIGHUP, mcleanup);
317 signal(SIGINT, mcleanup);
318 signal(SIGQUIT, mcleanup);
319 signal(SIGTERM, mcleanup);
320 memset(&un, 0, sizeof(un));
321 un.sun_family = AF_UNIX;
322 strcpy(un.sun_path, _PATH_SOCKETNAME);
323#ifndef SUN_LEN
324#define SUN_LEN(unp) (strlen((unp)->sun_path) + 2)
325#endif
326 if (bind(funix, (struct sockaddr *)&un, SUN_LEN(&un)) < 0) {
327 syslog(LOG_ERR, "ubind: %m");
328 exit(1);
329 }
330 (void) umask(0);
331 sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
332 FD_ZERO(&defreadfds);
333 FD_SET(funix, &defreadfds);
334 listen(funix, 5);
335 if (sflag == 0) {
336 finet = socksetup(family, socket_debug);
337 } else
338 finet = NULL; /* pretend we couldn't open TCP socket. */
339 if (finet) {
340 for (i = 1; i <= *finet; i++) {
341 FD_SET(finet[i], &defreadfds);
342 listen(finet[i], 5);
343 }
344 }
345 /*
346 * Main loop: accept, do a request, continue.
347 */
348 memset(&frominet, 0, sizeof(frominet));
349 memset(&fromunix, 0, sizeof(fromunix));
350 if (lflag)
351 syslog(LOG_INFO, "lpd startup: ready to accept requests");
352 /*
353 * XXX - should be redone for multi-protocol
354 */
355 for (;;) {
356 int domain, nfds, s;
357 fd_set readfds;
358
359 FD_COPY(&defreadfds, &readfds);
360 nfds = select(20, &readfds, 0, 0, 0);
361 if (nfds <= 0) {
362 if (nfds < 0 && errno != EINTR)
363 syslog(LOG_WARNING, "select: %m");
364 continue;
365 }
366 domain = -1; /* avoid compile-time warning */
367 s = -1; /* avoid compile-time warning */
368 if (FD_ISSET(funix, &readfds)) {
369 domain = AF_UNIX, fromlen = sizeof(fromunix);
370 s = accept(funix,
371 (struct sockaddr *)&fromunix, &fromlen);
372 } else {
373 for (i = 1; i <= *finet; i++)
374 if (FD_ISSET(finet[i], &readfds)) {
375 domain = AF_INET;
376 fromlen = sizeof(frominet);
377 s = accept(finet[i],
378 (struct sockaddr *)&frominet,
379 &fromlen);
380 }
381 }
382 if (s < 0) {
383 if (errno != EINTR)
384 syslog(LOG_WARNING, "accept: %m");
385 continue;
386 }
387 if (fork() == 0) {
388 /*
389 * Note that printjob() also plays around with
390 * signal-handling routines, and may need to be
391 * changed when making changes to signal-handling.
392 */
393 signal(SIGCHLD, SIG_DFL);
394 signal(SIGHUP, SIG_IGN);
395 signal(SIGINT, SIG_IGN);
396 signal(SIGQUIT, SIG_IGN);
397 signal(SIGTERM, SIG_IGN);
398 (void) close(funix);
399 if (sflag == 0 && finet) {
400 for (i = 1; i <= *finet; i++)
401 (void)close(finet[i]);
402 }
403 dup2(s, 1);
404 (void) close(s);
405 if (domain == AF_INET) {
406 /* for both AF_INET and AF_INET6 */
407 from_remote = 1;
408 chkhost((struct sockaddr *)&frominet,
409 ch_options);
410 } else
411 from_remote = 0;
412 doit();
413 exit(0);
414 }
415 (void) close(s);
416 }
417}
418
419static void
420reapchild(int signo __unused)
421{
422 int status;
423
424 while (wait3(&status, WNOHANG, 0) > 0)
425 ;
426}
427
428static void
429mcleanup(int signo)
430{
431 /*
432 * XXX syslog(3) is not signal-safe.
433 */
434 if (lflag) {
435 if (signo)
436 syslog(LOG_INFO, "exiting on signal %d", signo);
437 else
438 syslog(LOG_INFO, "exiting");
439 }
440 unlink(_PATH_SOCKETNAME);
441 exit(0);
442}
443
444/*
445 * Stuff for handling job specifications
446 */
447char *user[MAXUSERS]; /* users to process */
448int users; /* # of users in user array */
449int requ[MAXREQUESTS]; /* job number of spool entries */
450int requests; /* # of spool requests */
451char *person; /* name of person doing lprm */
452
453 /* buffer to hold the client's machine-name */
454static char frombuf[MAXHOSTNAMELEN];
455char cbuf[BUFSIZ]; /* command line buffer */
456const char *cmdnames[] = {
457 "null",
458 "printjob",
459 "recvjob",
460 "displayq short",
461 "displayq long",
462 "rmjob"
463};
464
465static void
466doit(void)
467{
468 char *cp, *printer;
469 int n;
470 int status;
471 struct printer myprinter, *pp = &myprinter;
472
473 init_printer(&myprinter);
474
475 for (;;) {
476 cp = cbuf;
477 do {
478 if (cp >= &cbuf[sizeof(cbuf) - 1])
479 fatal(0, "Command line too long");
480 if ((n = read(STDOUT_FILENO, cp, 1)) != 1) {
481 if (n < 0)
482 fatal(0, "Lost connection");
483 return;
484 }
485 } while (*cp++ != '\n');
486 *--cp = '\0';
487 cp = cbuf;
488 if (lflag) {
489 if (*cp >= '\1' && *cp <= '\5')
490 syslog(LOG_INFO, "%s requests %s %s",
491 from_host, cmdnames[(u_char)*cp], cp+1);
492 else
493 syslog(LOG_INFO, "bad request (%d) from %s",
494 *cp, from_host);
495 }
496 switch (*cp++) {
497 case CMD_CHECK_QUE: /* check the queue, print any jobs there */
498 startprinting(cp);
499 break;
500 case CMD_TAKE_THIS: /* receive files to be queued */
501 if (!from_remote) {
502 syslog(LOG_INFO, "illegal request (%d)", *cp);
503 exit(1);
504 }
505 recvjob(cp);
506 break;
507 case CMD_SHOWQ_SHORT: /* display the queue (short form) */
508 case CMD_SHOWQ_LONG: /* display the queue (long form) */
509 /* XXX - this all needs to be redone. */
510 printer = cp;
511 while (*cp) {
512 if (*cp != ' ') {
513 cp++;
514 continue;
515 }
516 *cp++ = '\0';
517 while (isspace(*cp))
518 cp++;
519 if (*cp == '\0')
520 break;
521 if (isdigit(*cp)) {
522 if (requests >= MAXREQUESTS)
523 fatal(0, "Too many requests");
524 requ[requests++] = atoi(cp);
525 } else {
526 if (users >= MAXUSERS)
527 fatal(0, "Too many users");
528 user[users++] = cp;
529 }
530 }
531 status = getprintcap(printer, pp);
532 if (status < 0)
533 fatal(pp, "%s", pcaperr(status));
534 displayq(pp, cbuf[0] == CMD_SHOWQ_LONG);
535 exit(0);
536 case CMD_RMJOB: /* remove a job from the queue */
537 if (!from_remote) {
538 syslog(LOG_INFO, "illegal request (%d)", *cp);
539 exit(1);
540 }
541 printer = cp;
542 while (*cp && *cp != ' ')
543 cp++;
544 if (!*cp)
545 break;
546 *cp++ = '\0';
547 person = cp;
548 while (*cp) {
549 if (*cp != ' ') {
550 cp++;
551 continue;
552 }
553 *cp++ = '\0';
554 while (isspace(*cp))
555 cp++;
556 if (*cp == '\0')
557 break;
558 if (isdigit(*cp)) {
559 if (requests >= MAXREQUESTS)
560 fatal(0, "Too many requests");
561 requ[requests++] = atoi(cp);
562 } else {
563 if (users >= MAXUSERS)
564 fatal(0, "Too many users");
565 user[users++] = cp;
566 }
567 }
568 rmjob(printer);
569 break;
570 }
571 fatal(0, "Illegal service request");
572 }
573}
574
575/*
576 * Make a pass through the printcap database and start printing any
577 * files left from the last time the machine went down.
578 */
579static void
580startup(void)
581{
582 int pid, status, more;
583 struct printer myprinter, *pp = &myprinter;
584
585 more = firstprinter(pp, &status);
586 if (status)
587 goto errloop;
588 while (more) {
589 if (ckqueue(pp) <= 0) {
590 goto next;
591 }
592 if (lflag)
593 syslog(LOG_INFO, "lpd startup: work for %s",
594 pp->printer);
595 if ((pid = fork()) < 0) {
596 syslog(LOG_WARNING, "lpd startup: cannot fork for %s",
597 pp->printer);
598 mcleanup(0);
599 }
600 if (pid == 0) {
601 lastprinter();
602 printjob(pp);
603 /* NOTREACHED */
604 }
605 do {
606next:
607 more = nextprinter(pp, &status);
608errloop:
609 if (status)
610 syslog(LOG_WARNING,
611 "lpd startup: printcap entry for %s has errors, skipping",
612 pp->printer ? pp->printer : "<noname?>");
613 } while (more && status);
614 }
615}
616
617/*
618 * Make sure there's some work to do before forking off a child
619 */
620static int
621ckqueue(struct printer *pp)
622{
be6b9a2e 623 struct dirent *d;
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624 DIR *dirp;
625 char *spooldir;
626
627 spooldir = pp->spool_dir;
628 if ((dirp = opendir(spooldir)) == NULL)
629 return (-1);
630 while ((d = readdir(dirp)) != NULL) {
631 if (d->d_name[0] != 'c' || d->d_name[1] != 'f')
632 continue; /* daemon control files only */
633 closedir(dirp);
634 return (1); /* found something */
635 }
636 closedir(dirp);
637 return (0);
638}
639
640#define DUMMY ":nobody::"
641
642/*
643 * Check to see if the host connecting to this host has access to any
644 * lpd services on this host.
645 */
646static void
647chkhost(struct sockaddr *f, int ch_opts)
648{
649 struct addrinfo hints, *res, *r;
be6b9a2e 650 FILE *hostf;
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651 char hostbuf[NI_MAXHOST], ip[NI_MAXHOST];
652 char serv[NI_MAXSERV];
653 char *syserr, *usererr;
654 int error, errsav, fpass, good, wantsl;
655
656 wantsl = 0;
657 if (ch_opts & LPD_LOGCONNERR)
658 wantsl = 1; /* also syslog the errors */
659
660 from_host = ".na.";
661
662 /* Need real hostname for temporary filenames */
663 error = getnameinfo(f, f->sa_len, hostbuf, sizeof(hostbuf), NULL, 0,
664 NI_NAMEREQD);
665 if (error) {
666 errsav = error;
667 error = getnameinfo(f, f->sa_len, hostbuf, sizeof(hostbuf),
668 NULL, 0, NI_NUMERICHOST | NI_WITHSCOPEID);
669 if (error) {
670 asprintf(&syserr,
671 "can not determine hostname for remote host (%d,%d)",
672 errsav, error);
673 asprintf(&usererr,
674 "Host name for your address is not known");
675 fhosterr(ch_opts, syserr, usererr);
676 /* NOTREACHED */
677 }
678 asprintf(&syserr,
679 "Host name for remote host (%s) not known (%d)",
680 hostbuf, errsav);
681 asprintf(&usererr,
682 "Host name for your address (%s) is not known",
683 hostbuf);
684 fhosterr(ch_opts, syserr, usererr);
685 /* NOTREACHED */
686 }
687
688 strlcpy(frombuf, hostbuf, sizeof(frombuf));
689 from_host = frombuf;
690 ch_opts |= LPD_ADDFROMLINE;
691
692 /* Need address in stringform for comparison (no DNS lookup here) */
693 error = getnameinfo(f, f->sa_len, hostbuf, sizeof(hostbuf), NULL, 0,
694 NI_NUMERICHOST | NI_WITHSCOPEID);
695 if (error) {
696 asprintf(&syserr, "Cannot print IP address (error %d)",
697 error);
698 asprintf(&usererr, "Cannot print IP address for your host");
699 fhosterr(ch_opts, syserr, usererr);
700 /* NOTREACHED */
701 }
702 from_ip = strdup(hostbuf);
703
704 /* Reject numeric addresses */
705 memset(&hints, 0, sizeof(hints));
706 hints.ai_family = family;
707 hints.ai_socktype = SOCK_DGRAM; /*dummy*/
708 hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST;
709 if (getaddrinfo(from_host, NULL, &hints, &res) == 0) {
710 freeaddrinfo(res);
711 /* This syslog message already includes from_host */
712 ch_opts &= ~LPD_ADDFROMLINE;
713 asprintf(&syserr, "reverse lookup results in non-FQDN %s",
714 from_host);
715 /* same message to both syslog and remote user */
716 fhosterr(ch_opts, syserr, syserr);
717 /* NOTREACHED */
718 }
719
720 /* Check for spoof, ala rlogind */
721 memset(&hints, 0, sizeof(hints));
722 hints.ai_family = family;
723 hints.ai_socktype = SOCK_DGRAM; /*dummy*/
724 error = getaddrinfo(from_host, NULL, &hints, &res);
725 if (error) {
726 asprintf(&syserr, "dns lookup for address %s failed: %s",
727 from_ip, gai_strerror(error));
728 asprintf(&usererr, "hostname for your address (%s) unknown: %s",
729 from_ip, gai_strerror(error));
730 fhosterr(ch_opts, syserr, usererr);
731 /* NOTREACHED */
732 }
733 good = 0;
734 for (r = res; good == 0 && r; r = r->ai_next) {
735 error = getnameinfo(r->ai_addr, r->ai_addrlen, ip, sizeof(ip),
736 NULL, 0, NI_NUMERICHOST | NI_WITHSCOPEID);
737 if (!error && !strcmp(from_ip, ip))
738 good = 1;
739 }
740 if (res)
741 freeaddrinfo(res);
742 if (good == 0) {
743 asprintf(&syserr, "address for remote host (%s) not matched",
744 from_ip);
745 asprintf(&usererr,
746 "address for your hostname (%s) not matched", from_ip);
747 fhosterr(ch_opts, syserr, usererr);
748 /* NOTREACHED */
749 }
750
751 fpass = 1;
752 hostf = fopen(_PATH_HOSTSEQUIV, "r");
753again:
754 if (hostf) {
755 if (__ivaliduser_sa(hostf, f, f->sa_len, DUMMY, DUMMY) == 0) {
756 (void) fclose(hostf);
757 goto foundhost;
758 }
759 (void) fclose(hostf);
760 }
761 if (fpass == 1) {
762 fpass = 2;
763 hostf = fopen(_PATH_HOSTSLPD, "r");
764 goto again;
765 }
766 /* This syslog message already includes from_host */
767 ch_opts &= ~LPD_ADDFROMLINE;
768 asprintf(&syserr, "refused connection from %s, sip=%s", from_host,
769 from_ip);
770 asprintf(&usererr,
771 "Print-services are not available to your host (%s).", from_host);
772 fhosterr(ch_opts, syserr, usererr);
773 /* NOTREACHED */
774
775foundhost:
776 if (ch_opts & LPD_NOPORTCHK)
777 return; /* skip the reserved-port check */
778
779 error = getnameinfo(f, f->sa_len, NULL, 0, serv, sizeof(serv),
780 NI_NUMERICSERV);
781 if (error) {
782 /* same message to both syslog and remote user */
783 asprintf(&syserr, "malformed from-address (%d)", error);
784 fhosterr(ch_opts, syserr, syserr);
785 /* NOTREACHED */
786 }
787
788 if (atoi(serv) >= IPPORT_RESERVED) {
789 /* same message to both syslog and remote user */
790 asprintf(&syserr, "connected from invalid port (%s)", serv);
791 fhosterr(ch_opts, syserr, syserr);
792 /* NOTREACHED */
793 }
794}
795
796/*
797 * Handle fatal errors in chkhost. The first message will optionally be
798 * sent to syslog, the second one is sent to the connecting host.
799 *
800 * The idea is that the syslog message is meant for an administrator of a
801 * print server (the host receiving connections), while the usermsg is meant
802 * for a remote user who may or may not be clueful, and may or may not be
803 * doing something nefarious. Some remote users (eg, MS-Windows...) may not
804 * even see whatever message is sent, which is why there's the option to
805 * start 'lpd' with the connection-errors also sent to syslog.
806 *
807 * Given that hostnames can theoretically be fairly long (well, over 250
808 * bytes), it would probably be helpful to have the 'from_host' field at
809 * the end of any error messages which include that info.
810 *
811 * These are Fatal host-connection errors, so this routine does not return.
812 */
813static void
814fhosterr(int ch_opts, char *sysmsg, char *usermsg)
815{
816
817 /*
818 * If lpd was started up to print connection errors, then write
819 * the syslog message before the user message.
820 * And for many of the syslog messages, it is helpful to first
821 * write the from_host (if it is known) as a separate syslog
822 * message, since the hostname may be so long.
823 */
824 if (ch_opts & LPD_LOGCONNERR) {
825 if (ch_opts & LPD_ADDFROMLINE) {
826 syslog(LOG_WARNING, "for connection from %s:", from_host);
827 }
828 syslog(LOG_WARNING, "%s", sysmsg);
829 }
830
831 /*
832 * Now send the error message to the remote host which is trying
833 * to make the connection.
834 */
835 printf("%s [@%s]: %s\n", progname, local_host, usermsg);
836 fflush(stdout);
837
838 /*
839 * Add a minimal delay before exiting (and disconnecting from the
840 * sending-host). This is just in case that machine responds by
841 * INSTANTLY retrying (and instantly re-failing...). This may also
842 * give the other side more time to read the error message.
843 */
844 sleep(2); /* a paranoid throttling measure */
845 exit(1);
846}
847
848/* setup server socket for specified address family */
849/* if af is PF_UNSPEC more than one socket may be returned */
850/* the returned list is dynamically allocated, so caller needs to free it */
851static int *
852socksetup(int af, int debuglvl)
853{
854 struct addrinfo hints, *res, *r;
855 int error, maxs, *s, *socks;
856 const int on = 1;
857
858 memset(&hints, 0, sizeof(hints));
859 hints.ai_flags = AI_PASSIVE;
860 hints.ai_family = af;
861 hints.ai_socktype = SOCK_STREAM;
862 error = getaddrinfo(NULL, "printer", &hints, &res);
863 if (error) {
864 syslog(LOG_ERR, "%s", gai_strerror(error));
865 mcleanup(0);
866 }
867
868 /* Count max number of sockets we may open */
869 for (maxs = 0, r = res; r; r = r->ai_next, maxs++)
870 ;
871 socks = malloc((maxs + 1) * sizeof(int));
872 if (!socks) {
873 syslog(LOG_ERR, "couldn't allocate memory for sockets");
874 mcleanup(0);
875 }
876
877 *socks = 0; /* num of sockets counter at start of array */
878 s = socks + 1;
879 for (r = res; r; r = r->ai_next) {
880 *s = socket(r->ai_family, r->ai_socktype, r->ai_protocol);
881 if (*s < 0) {
882 syslog(LOG_DEBUG, "socket(): %m");
883 continue;
884 }
885 if (setsockopt(*s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on))
886 < 0) {
887 syslog(LOG_ERR, "setsockopt(SO_REUSEADDR): %m");
888 close(*s);
889 continue;
890 }
891 if (debuglvl)
892 if (setsockopt(*s, SOL_SOCKET, SO_DEBUG, &debuglvl,
893 sizeof(debuglvl)) < 0) {
894 syslog(LOG_ERR, "setsockopt (SO_DEBUG): %m");
895 close(*s);
896 continue;
897 }
898#ifdef IPV6_BINDV6ONLY
899 if (r->ai_family == AF_INET6) {
900 if (setsockopt(*s, IPPROTO_IPV6, IPV6_BINDV6ONLY,
901 &on, sizeof(on)) < 0) {
902 syslog(LOG_ERR,
903 "setsockopt (IPV6_BINDV6ONLY): %m");
904 close(*s);
905 continue;
906 }
907 }
908#endif
909 if (bind(*s, r->ai_addr, r->ai_addrlen) < 0) {
910 syslog(LOG_DEBUG, "bind(): %m");
911 close(*s);
912 continue;
913 }
914 (*socks)++;
915 s++;
916 }
917
918 if (res)
919 freeaddrinfo(res);
920
921 if (*socks == 0) {
922 syslog(LOG_ERR, "Couldn't bind to any socket");
923 free(socks);
924 mcleanup(0);
925 }
926 return(socks);
927}
928
929static void
930usage(void)
931{
932#ifdef INET6
933 fprintf(stderr, "usage: lpd [-cdlsW46] [port#]\n");
934#else
935 fprintf(stderr, "usage: lpd [-cdlsW] [port#]\n");
936#endif
937 exit(EX_USAGE);
938}