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
|
/*
* 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 char sccsid[] = "@(#)lpd.c 8.7 (Berkeley) 5/10/95";
#endif
static const char rcsid[] =
"$FreeBSD$";
#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 daemon and spooling group
* 2. lpr runs setuid root and setgrp spooling group; it uses
* root to access any file it wants (verifying things before
* with an access call) and group id to know how it should
* set up ownership of files in the spooling area.
* 3. Files in spooling area are owned by root, group spooling
* group, with mode 660.
* 4. lpd, lpq and lprm run setuid daemon and setgrp spooling group to
* access files and printer. Users can't get to anything
* w/o help of lpq and lprm 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 <netdb.h>
#include <unistd.h>
#include <syslog.h>
#include <signal.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <ctype.h>
#include "lp.h"
#include "lp.local.h"
#include "pathnames.h"
#include "extern.h"
int lflag; /* log requests flag */
int pflag; /* no incoming port flag */
int from_remote; /* from remote socket */
int main __P((int, char **));
static void reapchild __P((int));
static void mcleanup __P((int));
static void doit __P((void));
static void startup __P((void));
static void chkhost __P((struct sockaddr_in *));
static int ckqueue __P((struct printer *));
static void usage __P((void));
/* From rcmd.c: */
int __ivaliduser __P((FILE *, u_long, const char *,
const char *));
uid_t uid, euid;
int
main(argc, argv)
int argc;
char **argv;
{
int errs, f, funix, finet, fromlen, i, socket_debug;
fd_set defreadfds;
struct sockaddr_un un, fromunix;
struct sockaddr_in sin, frominet;
int lfd;
sigset_t omask, nmask;
struct servent *sp, serv;
euid = geteuid(); /* these shouldn't be different */
uid = getuid();
socket_debug = 0;
gethostname(host, sizeof(host));
name = "lpd";
if (euid != 0)
errx(EX_NOPERM,"must run as root");
errs = 0;
while ((i = getopt(argc, argv, "dlp")) != -1)
switch (i) {
case 'd':
socket_debug++;
break;
case 'l':
lflag++;
break;
case 'p':
pflag++;
break;
default:
errs++;
}
argc -= optind;
argv += optind;
if (errs)
usage();
if (argc == 1) {
if ((i = atoi(argv[0])) == 0)
usage();
if (i < 0 || i > USHRT_MAX)
errx(EX_USAGE, "port # %d is invalid", i);
serv.s_port = htons(i);
sp = &serv;
argc--;
} else {
sp = getservbyname("printer", "tcp");
if (sp == NULL)
errx(EX_OSFILE, "printer/tcp: unknown service");
}
if (argc != 0)
usage();
/*
* We run chkprintcap right away to catch any errors and blat them
* to stderr while we still have it open, rather than sending them
* to syslog and leaving the user wondering why lpd started and
* then stopped. There should probably be a command-line flag to
* ignore errors from chkprintcap.
*/
{
pid_t pid;
int status;
pid = fork();
if (pid < 0) {
err(EX_OSERR, "cannot fork");
} else if (pid == 0) { /* child */
execl(_PATH_CHKPRINTCAP, _PATH_CHKPRINTCAP, (char *)0);
err(EX_OSERR, "cannot execute %s", _PATH_CHKPRINTCAP);
}
if (waitpid(pid, &status, 0) < 0) {
err(EX_OSERR, "cannot wait");
}
if (WIFEXITED(status) && WEXITSTATUS(status) != 0)
errx(EX_OSFILE, "%d errors in printcap file, exiting",
WEXITSTATUS(status));
}
#ifndef DEBUG
/*
* Set up standard environment by detaching from the parent.
*/
daemon(0, 0);
#endif
openlog("lpd", LOG_PID, LOG_LPR);
syslog(LOG_INFO, "lpd startup: logging=%d%s", lflag,
socket_debug ? " dbg" : "");
(void) umask(0);
/*
* NB: This depends on O_NONBLOCK semantics doing the right thing;
* i.e., applying only to the O_EXLOCK and not to the rest of the
* open/creation. As of 1997-12-02, this is the case for commonly-
* used filesystems. There are other places in this code which
* make the same assumption.
*/
lfd = open(_PATH_MASTERLOCK, O_WRONLY|O_CREAT|O_EXLOCK|O_NONBLOCK,
LOCK_FILE_MODE);
if (lfd < 0) {
if (errno == EWOULDBLOCK) /* active deamon present */
exit(0);
syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK);
exit(1);
}
fcntl(lfd, F_SETFL, 0); /* turn off non-blocking mode */
ftruncate(lfd, 0);
/*
* write process id for others to know
*/
sprintf(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();
(void) unlink(_PATH_SOCKETNAME);
funix = socket(AF_UNIX, SOCK_STREAM, 0);
if (funix < 0) {
syslog(LOG_ERR, "socket: %m");
exit(1);
}
sigemptyset(&nmask);
sigaddset(&nmask, SIGHUP);
sigaddset(&nmask, SIGINT);
sigaddset(&nmask, SIGQUIT);
sigaddset(&nmask, SIGTERM);
sigprocmask(SIG_BLOCK, &nmask, &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_UNIX;
strcpy(un.sun_path, _PATH_SOCKETNAME);
#ifndef SUN_LEN
#define SUN_LEN(unp) (strlen((unp)->sun_path) + 2)
#endif
if (bind(funix, (struct sockaddr *)&un, SUN_LEN(&un)) < 0) {
syslog(LOG_ERR, "ubind: %m");
exit(1);
}
(void) umask(0);
sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
FD_ZERO(&defreadfds);
FD_SET(funix, &defreadfds);
listen(funix, 5);
finet = -1;
if (pflag == 0) {
finet = socket(AF_INET, SOCK_STREAM, 0);
if (finet >= 0) {
i = 1;
if (setsockopt(finet, SOL_SOCKET, SO_REUSEADDR, &i,
sizeof i) < 0) {
syslog(LOG_ERR, "setsockopt(SO_REUSEADDR): %m");
mcleanup(0);
}
if (socket_debug &&
setsockopt(finet, SOL_SOCKET, SO_DEBUG,
&socket_debug, sizeof(socket_debug)) < 0) {
syslog(LOG_ERR, "setsockopt (SO_DEBUG): %m");
mcleanup(0);
}
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_port = sp->s_port;
if (bind(finet, (struct sockaddr *)&sin,
sizeof(sin)) < 0) {
syslog(LOG_ERR, "bind: %m");
mcleanup(0);
}
FD_SET(finet, &defreadfds);
listen(finet, 5);
}
}
/*
* Main loop: accept, do a request, continue.
*/
memset(&frominet, 0, sizeof(frominet));
memset(&fromunix, 0, sizeof(fromunix));
if (lflag)
syslog(LOG_INFO, "lpd startup: ready to accept requests");
/*
* XXX - should be redone for multi-protocol
*/
for (;;) {
int domain, nfds, s;
fd_set readfds;
FD_COPY(&defreadfds, &readfds);
nfds = select(20, &readfds, 0, 0, 0);
if (nfds <= 0) {
if (nfds < 0 && errno != EINTR)
syslog(LOG_WARNING, "select: %m");
continue;
}
domain = 0; /* avoid compile-time warning */
s = 0; /* avoid compile-time warning */
if (FD_ISSET(funix, &readfds)) {
domain = AF_UNIX, fromlen = sizeof(fromunix);
s = accept(funix,
(struct sockaddr *)&fromunix, &fromlen);
} else if (pflag == 0) /* if (FD_ISSET(finet, &readfds)) */ {
domain = AF_INET, fromlen = sizeof(frominet);
s = accept(finet,
(struct sockaddr *)&frominet, &fromlen);
if (frominet.sin_port == htons(20)) {
close(s);
continue;
}
}
if (s < 0) {
if (errno != EINTR)
syslog(LOG_WARNING, "accept: %m");
continue;
}
if (fork() == 0) {
signal(SIGCHLD, SIG_IGN);
signal(SIGHUP, SIG_IGN);
signal(SIGINT, SIG_IGN);
signal(SIGQUIT, SIG_IGN);
signal(SIGTERM, SIG_IGN);
(void) close(funix);
if (pflag == 0) {
(void) close(finet);
}
dup2(s, 1);
(void) close(s);
if (domain == AF_INET) {
from_remote = 1;
chkhost(&frominet);
} else
from_remote = 0;
doit();
exit(0);
}
(void) close(s);
}
}
static void
reapchild(signo)
int signo;
{
union wait status;
while (wait3((int *)&status, WNOHANG, 0) > 0)
;
}
static void
mcleanup(signo)
int signo;
{
/*
* XXX syslog(3) is not signal-safe.
*/
if (lflag) {
if (signo)
syslog(LOG_INFO, "exiting on signal %d", signo);
else
syslog(LOG_INFO, "exiting");
}
unlink(_PATH_SOCKETNAME);
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[MAXHOSTNAMELEN]; /* 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()
{
char *cp, *printer;
int n;
int status;
struct printer myprinter, *pp = &myprinter;
init_printer(&myprinter);
for (;;) {
cp = cbuf;
do {
if (cp >= &cbuf[sizeof(cbuf) - 1])
fatal(0, "Command line too long");
if ((n = read(1, cp, 1)) != 1) {
if (n < 0)
fatal(0, "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[(u_char)*cp], cp+1);
else
syslog(LOG_INFO, "bad request (%d) from %s",
*cp, from);
}
switch (*cp++) {
case CMD_CHECK_QUE: /* check the queue, print any jobs there */
startprinting(cp);
break;
case CMD_TAKE_THIS: /* receive files to be queued */
if (!from_remote) {
syslog(LOG_INFO, "illegal request (%d)", *cp);
exit(1);
}
recvjob(cp);
break;
case CMD_SHOWQ_SHORT: /* display the queue (short form) */
case CMD_SHOWQ_LONG: /* display the queue (long form) */
/* XXX - this all needs to be redone. */
printer = cp;
while (*cp) {
if (*cp != ' ') {
cp++;
continue;
}
*cp++ = '\0';
while (isspace(*cp))
cp++;
if (*cp == '\0')
break;
if (isdigit(*cp)) {
if (requests >= MAXREQUESTS)
fatal(0, "Too many requests");
requ[requests++] = atoi(cp);
} else {
if (users >= MAXUSERS)
fatal(0, "Too many users");
user[users++] = cp;
}
}
status = getprintcap(printer, pp);
if (status < 0)
fatal(pp, pcaperr(status));
displayq(pp, cbuf[0] == CMD_SHOWQ_LONG);
exit(0);
case CMD_RMJOB: /* remove a job from the queue */
if (!from_remote) {
syslog(LOG_INFO, "illegal request (%d)", *cp);
exit(1);
}
printer = cp;
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(0, "Too many requests");
requ[requests++] = atoi(cp);
} else {
if (users >= MAXUSERS)
fatal(0, "Too many users");
user[users++] = cp;
}
}
rmjob(printer);
break;
}
fatal(0, "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()
{
int pid, status, more;
struct printer myprinter, *pp = &myprinter;
more = firstprinter(pp, &status);
if (status)
goto errloop;
while (more) {
if (ckqueue(pp) <= 0) {
goto next;
}
if (lflag)
syslog(LOG_INFO, "lpd startup: work for %s",
pp->printer);
if ((pid = fork()) < 0) {
syslog(LOG_WARNING, "lpd startup: cannot fork for %s",
pp->printer);
mcleanup(0);
}
if (pid == 0) {
lastprinter();
printjob(pp);
/* NOTREACHED */
}
do {
next:
more = nextprinter(pp, &status);
errloop:
if (status)
syslog(LOG_WARNING,
"lpd startup: printcap entry for %s has errors, skipping",
pp->printer ? pp->printer : "<???>");
} while (more && status);
}
}
/*
* Make sure there's some work to do before forking off a child
*/
static int
ckqueue(pp)
struct printer *pp;
{
register struct dirent *d;
DIR *dirp;
char *spooldir;
spooldir = pp->spool_dir;
if ((dirp = opendir(spooldir)) == NULL)
return (-1);
while ((d = readdir(dirp)) != NULL) {
if (d->d_name[0] != 'c' || d->d_name[1] != 'f')
continue; /* daemon control files only */
closedir(dirp);
return (1); /* found something */
}
closedir(dirp);
return (0);
}
#define DUMMY ":nobody::"
/*
* Check to see if the from host has access to the line printer.
*/
static void
chkhost(f)
struct sockaddr_in *f;
{
register struct hostent *hp;
register FILE *hostf;
int first = 1;
int good = 0;
/* Need real hostname for temporary filenames */
hp = gethostbyaddr((char *)&f->sin_addr,
sizeof(struct in_addr), f->sin_family);
if (hp == NULL)
fatal(0, "Host name for your address (%s) unknown",
inet_ntoa(f->sin_addr));
(void) strncpy(fromb, hp->h_name, sizeof(fromb) - 1);
fromb[sizeof(fromb) - 1] = '\0';
from = fromb;
strncpy(from_ip, inet_ntoa(f->sin_addr), MAXIPSTRLEN);
from_ip[sizeof(from_ip) - 1] = '\0';
/* Check for spoof, ala rlogind */
hp = gethostbyname(fromb);
if (!hp)
fatal(0, "hostname for your address (%s) unknown", from_ip);
for (; good == 0 && hp->h_addr_list[0] != NULL; hp->h_addr_list++) {
if (!bcmp(hp->h_addr_list[0], (caddr_t)&f->sin_addr,
sizeof(f->sin_addr)))
good = 1;
}
if (good == 0)
fatal(0, "address for your hostname (%s) not matched",
from_ip);
hostf = fopen(_PATH_HOSTSEQUIV, "r");
again:
if (hostf) {
if (__ivaliduser(hostf, f->sin_addr.s_addr,
DUMMY, DUMMY) == 0) {
(void) fclose(hostf);
return;
}
(void) fclose(hostf);
}
if (first == 1) {
first = 0;
hostf = fopen(_PATH_HOSTSLPD, "r");
goto again;
}
fatal(0, "Your host does not have line printer access");
/*NOTREACHED*/
}
static void
usage()
{
fprintf(stderr, "usage: lpd [-dlp] [port#]\n");
exit(EX_USAGE);
}
|