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a31f3663 WJ |
1 | /* |
2 | * Copyright (c) 1983 Regents of the University of California. | |
3 | * All rights reserved. | |
4 | * | |
5 | * Redistribution and use in source and binary forms, with or without | |
6 | * modification, are permitted provided that the following conditions | |
7 | * are met: | |
8 | * 1. Redistributions of source code must retain the above copyright | |
9 | * notice, this list of conditions and the following disclaimer. | |
10 | * 2. Redistributions in binary form must reproduce the above copyright | |
11 | * notice, this list of conditions and the following disclaimer in the | |
12 | * documentation and/or other materials provided with the distribution. | |
13 | * 3. All advertising materials mentioning features or use of this software | |
14 | * must display the following acknowledgement: | |
15 | * This product includes software developed by the University of | |
16 | * California, Berkeley and its contributors. | |
17 | * 4. Neither the name of the University nor the names of its contributors | |
18 | * may be used to endorse or promote products derived from this software | |
19 | * without specific prior written permission. | |
20 | * | |
21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
31 | * SUCH DAMAGE. | |
32 | */ | |
33 | ||
34 | #ifndef lint | |
35 | char copyright[] = | |
36 | "@(#) Copyright (c) 1983 Regents of the University of California.\n\ | |
37 | All rights reserved.\n"; | |
38 | #endif /* not lint */ | |
39 | ||
40 | #ifndef lint | |
41 | static char sccsid[] = "@(#)lpd.c 5.12 (Berkeley) 3/7/91"; | |
42 | #endif /* not lint */ | |
43 | ||
44 | /* | |
45 | * lpd -- line printer daemon. | |
46 | * | |
47 | * Listen for a connection and perform the requested operation. | |
48 | * Operations are: | |
49 | * \1printer\n | |
50 | * check the queue for jobs and print any found. | |
51 | * \2printer\n | |
52 | * receive a job from another machine and queue it. | |
53 | * \3printer [users ...] [jobs ...]\n | |
54 | * return the current state of the queue (short form). | |
55 | * \4printer [users ...] [jobs ...]\n | |
56 | * return the current state of the queue (long form). | |
57 | * \5printer person [users ...] [jobs ...]\n | |
58 | * remove jobs from the queue. | |
59 | * | |
60 | * Strategy to maintain protected spooling area: | |
61 | * 1. Spooling area is writable only by daemon and spooling group | |
62 | * 2. lpr runs setuid root and setgrp spooling group; it uses | |
63 | * root to access any file it wants (verifying things before | |
64 | * with an access call) and group id to know how it should | |
65 | * set up ownership of files in the spooling area. | |
66 | * 3. Files in spooling area are owned by root, group spooling | |
67 | * group, with mode 660. | |
68 | * 4. lpd, lpq and lprm run setuid daemon and setgrp spooling group to | |
69 | * access files and printer. Users can't get to anything | |
70 | * w/o help of lpq and lprm programs. | |
71 | */ | |
72 | ||
73 | #include "lp.h" | |
74 | #include "pathnames.h" | |
75 | ||
76 | int lflag; /* log requests flag */ | |
77 | int from_remote; /* from remote socket */ | |
78 | ||
79 | void mcleanup(), reapchild(); | |
80 | ||
81 | main(argc, argv) | |
82 | int argc; | |
83 | char **argv; | |
84 | { | |
85 | int f, funix, finet, options = 0, defreadfds, fromlen; | |
86 | struct sockaddr_un sun, fromunix; | |
87 | struct sockaddr_in sin, frominet; | |
88 | int omask, lfd; | |
89 | ||
90 | gethostname(host, sizeof(host)); | |
91 | name = argv[0]; | |
92 | ||
93 | while (--argc > 0) { | |
94 | argv++; | |
95 | if (argv[0][0] == '-') | |
96 | switch (argv[0][1]) { | |
97 | case 'd': | |
98 | options |= SO_DEBUG; | |
99 | break; | |
100 | case 'l': | |
101 | lflag++; | |
102 | break; | |
103 | } | |
104 | } | |
105 | ||
106 | #ifndef DEBUG | |
107 | /* | |
108 | * Set up standard environment by detaching from the parent. | |
109 | */ | |
110 | daemon(0, 0); | |
111 | #endif | |
112 | ||
113 | openlog("lpd", LOG_PID, LOG_LPR); | |
114 | (void) umask(0); | |
115 | lfd = open(_PATH_MASTERLOCK, O_WRONLY|O_CREAT, 0644); | |
116 | if (lfd < 0) { | |
117 | syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK); | |
118 | exit(1); | |
119 | } | |
120 | if (flock(lfd, LOCK_EX|LOCK_NB) < 0) { | |
121 | if (errno == EWOULDBLOCK) /* active deamon present */ | |
122 | exit(0); | |
123 | syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK); | |
124 | exit(1); | |
125 | } | |
126 | ftruncate(lfd, 0); | |
127 | /* | |
128 | * write process id for others to know | |
129 | */ | |
130 | sprintf(line, "%u\n", getpid()); | |
131 | f = strlen(line); | |
132 | if (write(lfd, line, f) != f) { | |
133 | syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK); | |
134 | exit(1); | |
135 | } | |
136 | signal(SIGCHLD, reapchild); | |
137 | /* | |
138 | * Restart all the printers. | |
139 | */ | |
140 | startup(); | |
141 | (void) unlink(_PATH_SOCKETNAME); | |
142 | funix = socket(AF_UNIX, SOCK_STREAM, 0); | |
143 | if (funix < 0) { | |
144 | syslog(LOG_ERR, "socket: %m"); | |
145 | exit(1); | |
146 | } | |
147 | #define mask(s) (1 << ((s) - 1)) | |
148 | omask = sigblock(mask(SIGHUP)|mask(SIGINT)|mask(SIGQUIT)|mask(SIGTERM)); | |
149 | signal(SIGHUP, mcleanup); | |
150 | signal(SIGINT, mcleanup); | |
151 | signal(SIGQUIT, mcleanup); | |
152 | signal(SIGTERM, mcleanup); | |
153 | sun.sun_family = AF_UNIX; | |
154 | strcpy(sun.sun_path, _PATH_SOCKETNAME); | |
155 | if (bind(funix, | |
156 | (struct sockaddr *)&sun, strlen(sun.sun_path) + 2) < 0) { | |
157 | syslog(LOG_ERR, "ubind: %m"); | |
158 | exit(1); | |
159 | } | |
160 | sigsetmask(omask); | |
161 | defreadfds = 1 << funix; | |
162 | listen(funix, 5); | |
163 | finet = socket(AF_INET, SOCK_STREAM, 0); | |
164 | if (finet >= 0) { | |
165 | struct servent *sp; | |
166 | ||
167 | if (options & SO_DEBUG) | |
168 | if (setsockopt(finet, SOL_SOCKET, SO_DEBUG, 0, 0) < 0) { | |
169 | syslog(LOG_ERR, "setsockopt (SO_DEBUG): %m"); | |
170 | mcleanup(); | |
171 | } | |
172 | sp = getservbyname("printer", "tcp"); | |
173 | if (sp == NULL) { | |
174 | syslog(LOG_ERR, "printer/tcp: unknown service"); | |
175 | mcleanup(); | |
176 | } | |
177 | sin.sin_family = AF_INET; | |
178 | sin.sin_port = sp->s_port; | |
179 | if (bind(finet, (struct sockaddr *)&sin, sizeof(sin)) < 0) { | |
180 | syslog(LOG_ERR, "bind: %m"); | |
181 | mcleanup(); | |
182 | } | |
183 | defreadfds |= 1 << finet; | |
184 | listen(finet, 5); | |
185 | } | |
186 | /* | |
187 | * Main loop: accept, do a request, continue. | |
188 | */ | |
189 | for (;;) { | |
190 | int domain, nfds, s, readfds = defreadfds; | |
191 | ||
192 | nfds = select(20, &readfds, 0, 0, 0); | |
193 | if (nfds <= 0) { | |
194 | if (nfds < 0 && errno != EINTR) | |
195 | syslog(LOG_WARNING, "select: %m"); | |
196 | continue; | |
197 | } | |
198 | if (readfds & (1 << funix)) { | |
199 | domain = AF_UNIX, fromlen = sizeof(fromunix); | |
200 | s = accept(funix, | |
201 | (struct sockaddr *)&fromunix, &fromlen); | |
202 | } else if (readfds & (1 << finet)) { | |
203 | domain = AF_INET, fromlen = sizeof(frominet); | |
204 | s = accept(finet, | |
205 | (struct sockaddr *)&frominet, &fromlen); | |
206 | } | |
207 | if (s < 0) { | |
208 | if (errno != EINTR) | |
209 | syslog(LOG_WARNING, "accept: %m"); | |
210 | continue; | |
211 | } | |
212 | if (fork() == 0) { | |
213 | signal(SIGCHLD, SIG_IGN); | |
214 | signal(SIGHUP, SIG_IGN); | |
215 | signal(SIGINT, SIG_IGN); | |
216 | signal(SIGQUIT, SIG_IGN); | |
217 | signal(SIGTERM, SIG_IGN); | |
218 | (void) close(funix); | |
219 | (void) close(finet); | |
220 | dup2(s, 1); | |
221 | (void) close(s); | |
222 | if (domain == AF_INET) { | |
223 | from_remote = 1; | |
224 | chkhost(&frominet); | |
225 | } else | |
226 | from_remote = 0; | |
227 | doit(); | |
228 | exit(0); | |
229 | } | |
230 | (void) close(s); | |
231 | } | |
232 | } | |
233 | ||
234 | void | |
235 | reapchild() | |
236 | { | |
237 | union wait status; | |
238 | ||
239 | while (wait3((int *)&status, WNOHANG, 0) > 0) | |
240 | ; | |
241 | } | |
242 | ||
243 | void | |
244 | mcleanup() | |
245 | { | |
246 | if (lflag) | |
247 | syslog(LOG_INFO, "exiting"); | |
248 | unlink(_PATH_SOCKETNAME); | |
249 | exit(0); | |
250 | } | |
251 | ||
252 | /* | |
253 | * Stuff for handling job specifications | |
254 | */ | |
255 | char *user[MAXUSERS]; /* users to process */ | |
256 | int users; /* # of users in user array */ | |
257 | int requ[MAXREQUESTS]; /* job number of spool entries */ | |
258 | int requests; /* # of spool requests */ | |
259 | char *person; /* name of person doing lprm */ | |
260 | ||
261 | char fromb[32]; /* buffer for client's machine name */ | |
262 | char cbuf[BUFSIZ]; /* command line buffer */ | |
263 | char *cmdnames[] = { | |
264 | "null", | |
265 | "printjob", | |
266 | "recvjob", | |
267 | "displayq short", | |
268 | "displayq long", | |
269 | "rmjob" | |
270 | }; | |
271 | ||
272 | doit() | |
273 | { | |
274 | register char *cp; | |
275 | register int n; | |
276 | ||
277 | for (;;) { | |
278 | cp = cbuf; | |
279 | do { | |
280 | if (cp >= &cbuf[sizeof(cbuf) - 1]) | |
281 | fatal("Command line too long"); | |
282 | if ((n = read(1, cp, 1)) != 1) { | |
283 | if (n < 0) | |
284 | fatal("Lost connection"); | |
285 | return; | |
286 | } | |
287 | } while (*cp++ != '\n'); | |
288 | *--cp = '\0'; | |
289 | cp = cbuf; | |
290 | if (lflag) { | |
291 | if (*cp >= '\1' && *cp <= '\5') | |
292 | syslog(LOG_INFO, "%s requests %s %s", | |
293 | from, cmdnames[*cp], cp+1); | |
294 | else | |
295 | syslog(LOG_INFO, "bad request (%d) from %s", | |
296 | *cp, from); | |
297 | } | |
298 | switch (*cp++) { | |
299 | case '\1': /* check the queue and print any jobs there */ | |
300 | printer = cp; | |
301 | printjob(); | |
302 | break; | |
303 | case '\2': /* receive files to be queued */ | |
304 | if (!from_remote) { | |
305 | syslog(LOG_INFO, "illegal request (%d)", *cp); | |
306 | exit(1); | |
307 | } | |
308 | printer = cp; | |
309 | recvjob(); | |
310 | break; | |
311 | case '\3': /* display the queue (short form) */ | |
312 | case '\4': /* display the queue (long form) */ | |
313 | printer = cp; | |
314 | while (*cp) { | |
315 | if (*cp != ' ') { | |
316 | cp++; | |
317 | continue; | |
318 | } | |
319 | *cp++ = '\0'; | |
320 | while (isspace(*cp)) | |
321 | cp++; | |
322 | if (*cp == '\0') | |
323 | break; | |
324 | if (isdigit(*cp)) { | |
325 | if (requests >= MAXREQUESTS) | |
326 | fatal("Too many requests"); | |
327 | requ[requests++] = atoi(cp); | |
328 | } else { | |
329 | if (users >= MAXUSERS) | |
330 | fatal("Too many users"); | |
331 | user[users++] = cp; | |
332 | } | |
333 | } | |
334 | displayq(cbuf[0] - '\3'); | |
335 | exit(0); | |
336 | case '\5': /* remove a job from the queue */ | |
337 | if (!from_remote) { | |
338 | syslog(LOG_INFO, "illegal request (%d)", *cp); | |
339 | exit(1); | |
340 | } | |
341 | printer = cp; | |
342 | while (*cp && *cp != ' ') | |
343 | cp++; | |
344 | if (!*cp) | |
345 | break; | |
346 | *cp++ = '\0'; | |
347 | person = cp; | |
348 | while (*cp) { | |
349 | if (*cp != ' ') { | |
350 | cp++; | |
351 | continue; | |
352 | } | |
353 | *cp++ = '\0'; | |
354 | while (isspace(*cp)) | |
355 | cp++; | |
356 | if (*cp == '\0') | |
357 | break; | |
358 | if (isdigit(*cp)) { | |
359 | if (requests >= MAXREQUESTS) | |
360 | fatal("Too many requests"); | |
361 | requ[requests++] = atoi(cp); | |
362 | } else { | |
363 | if (users >= MAXUSERS) | |
364 | fatal("Too many users"); | |
365 | user[users++] = cp; | |
366 | } | |
367 | } | |
368 | rmjob(); | |
369 | break; | |
370 | } | |
371 | fatal("Illegal service request"); | |
372 | } | |
373 | } | |
374 | ||
375 | /* | |
376 | * Make a pass through the printcap database and start printing any | |
377 | * files left from the last time the machine went down. | |
378 | */ | |
379 | startup() | |
380 | { | |
381 | char buf[BUFSIZ]; | |
382 | register char *cp; | |
383 | int pid; | |
384 | ||
385 | printer = buf; | |
386 | ||
387 | /* | |
388 | * Restart the daemons. | |
389 | */ | |
390 | while (getprent(buf) > 0) { | |
391 | for (cp = buf; *cp; cp++) | |
392 | if (*cp == '|' || *cp == ':') { | |
393 | *cp = '\0'; | |
394 | break; | |
395 | } | |
396 | if ((pid = fork()) < 0) { | |
397 | syslog(LOG_WARNING, "startup: cannot fork"); | |
398 | mcleanup(); | |
399 | } | |
400 | if (!pid) { | |
401 | endprent(); | |
402 | printjob(); | |
403 | } | |
404 | } | |
405 | } | |
406 | ||
407 | #define DUMMY ":nobody::" | |
408 | ||
409 | /* | |
410 | * Check to see if the from host has access to the line printer. | |
411 | */ | |
412 | chkhost(f) | |
413 | struct sockaddr_in *f; | |
414 | { | |
415 | register struct hostent *hp; | |
416 | register FILE *hostf; | |
417 | register char *cp, *sp; | |
418 | char ahost[50]; | |
419 | int first = 1; | |
420 | extern char *inet_ntoa(); | |
421 | int baselen = -1; | |
422 | ||
423 | f->sin_port = ntohs(f->sin_port); | |
424 | if (f->sin_family != AF_INET || f->sin_port >= IPPORT_RESERVED) | |
425 | fatal("Malformed from address"); | |
426 | hp = gethostbyaddr((char *)&f->sin_addr, | |
427 | sizeof(struct in_addr), f->sin_family); | |
428 | if (hp == 0) | |
429 | fatal("Host name for your address (%s) unknown", | |
430 | inet_ntoa(f->sin_addr)); | |
431 | ||
432 | strcpy(fromb, hp->h_name); | |
433 | from = fromb; | |
434 | if (!strcmp(from, host)) | |
435 | return; | |
436 | ||
437 | sp = fromb; | |
438 | cp = ahost; | |
439 | while (*sp) { | |
440 | if (*sp == '.') { | |
441 | if (baselen == -1) | |
442 | baselen = sp - fromb; | |
443 | *cp++ = *sp++; | |
444 | } else { | |
445 | *cp++ = isupper(*sp) ? tolower(*sp++) : *sp++; | |
446 | } | |
447 | } | |
448 | *cp = '\0'; | |
449 | hostf = fopen(_PATH_HOSTSEQUIV, "r"); | |
450 | again: | |
451 | if (hostf) { | |
452 | if (!_validuser(hostf, ahost, DUMMY, DUMMY, baselen)) { | |
453 | (void) fclose(hostf); | |
454 | return; | |
455 | } | |
456 | (void) fclose(hostf); | |
457 | } | |
458 | if (first == 1) { | |
459 | first = 0; | |
460 | hostf = fopen(_PATH_HOSTSLPD, "r"); | |
461 | goto again; | |
462 | } | |
463 | fatal("Your host does not have line printer access"); | |
464 | } |