xref: /openbsd-src/usr.sbin/lpr/common_source/rmjob.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*	$OpenBSD: rmjob.c,v 1.17 2007/04/07 21:12:12 stevesk Exp $	*/
2 /*	$NetBSD: rmjob.c,v 1.16 2000/04/16 14:43:58 mrg Exp $	*/
3 
4 /*
5  * Copyright (c) 1983, 1993
6  *	The Regents of the University of California.  All rights reserved.
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 #ifndef lint
34 #if 0
35 static const char sccsid[] = "@(#)rmjob.c	8.2 (Berkeley) 4/28/95";
36 #else
37 static const char rcsid[] = "$OpenBSD: rmjob.c,v 1.17 2007/04/07 21:12:12 stevesk Exp $";
38 #endif
39 #endif /* not lint */
40 
41 #include <sys/param.h>
42 
43 #include <signal.h>
44 #include <errno.h>
45 #include <fcntl.h>
46 #include <dirent.h>
47 #include <unistd.h>
48 #include <stdlib.h>
49 #include <stdio.h>
50 #include <string.h>
51 #include <ctype.h>
52 #include "lp.h"
53 #include "lp.local.h"
54 #include "pathnames.h"
55 
56 /*
57  * rmjob - remove the specified jobs from the queue.
58  */
59 
60 /*
61  * Stuff for handling lprm specifications
62  */
63 extern char	*user[];		/* users to process */
64 extern int	users;			/* # of users in user array */
65 extern int	requ[];			/* job number of spool entries */
66 extern int	requests;		/* # of spool requests */
67 extern char	*person;		/* name of person doing lprm */
68 
69 static char	root[] = "root";
70 static int	all = 0;		/* eliminate all files (root only) */
71 static int	cur_daemon;		/* daemon's pid */
72 static char	current[NAME_MAX];	/* active control file name */
73 
74 static	void	do_unlink(char *);
75 static	void	alarmer(int);
76 static	int	lockchk(char *);
77 
78 void
79 rmjob(void)
80 {
81 	int i, nitems;
82 	int assasinated = 0;
83 	struct dirent **files;
84 	char *cp;
85 
86 	if ((i = cgetent(&bp, printcapdb, printer)) == -2)
87 		fatal("can't open printer description file");
88 	else if (i == -1)
89 		fatal("unknown printer");
90 	else if (i == -3)
91 		fatal("potential reference loop detected in printcap file");
92 	if (cgetstr(bp, DEFLP, &LP) < 0)
93 		LP = _PATH_DEFDEVLP;
94 	if (cgetstr(bp, "rp", &RP) < 0)
95 		RP = DEFLP;
96 	if (cgetstr(bp, "sd", &SD) < 0)
97 		SD = _PATH_DEFSPOOL;
98 	if (cgetstr(bp,"lo", &LO) < 0)
99 		LO = DEFLOCK;
100 	cgetstr(bp, "rm", &RM);
101 	if ((cp = checkremote()) != NULL)
102 		printf("Warning: %s\n", cp);
103 
104 	/*
105 	 * If the format was `lprm -' and the user isn't the super-user,
106 	 *  then fake things to look like he said `lprm user'.
107 	 */
108 	if (users < 0) {
109 		if (getuid() == 0)
110 			all = 1;	/* all files in local queue */
111 		else {
112 			user[0] = person;
113 			users = 1;
114 		}
115 	}
116 	if (!strcmp(person, "-all")) {
117 		if (from == host)
118 			fatal("The login name \"-all\" is reserved");
119 		all = 1;	/* all those from 'from' */
120 		person = root;
121 	}
122 
123 	PRIV_START;
124 	if (chdir(SD) < 0)
125 		fatal("cannot chdir to spool directory");
126 	if ((nitems = scandir(".", &files, iscf, NULL)) < 0)
127 		fatal("cannot access spool directory");
128 	PRIV_END;
129 
130 	if (nitems) {
131 		/*
132 		 * Check for an active printer daemon.  If one is running
133 		 * and it is reading our file, kill it, then remove stuff.
134 		 * Lastly, restart the daemon if it is not (or no longer)
135 		 * running.
136 		 */
137 		if (lockchk(LO) && chk(current)) {
138 			PRIV_START;
139 			assasinated = kill(cur_daemon, SIGINT) == 0;
140 			PRIV_END;
141 			if (!assasinated)
142 				fatal("cannot kill printer daemon");
143 		}
144 		/*
145 		 * process the files
146 		 */
147 		for (i = 0; i < nitems; i++)
148 			process(files[i]->d_name);
149 	}
150 	rmremote();
151 	/*
152 	 * Restart the printer daemon if it was killed
153 	 */
154 	if (assasinated && !startdaemon(printer))
155 		fatal("cannot restart printer daemon");
156 	exit(0);
157 }
158 
159 /*
160  * Process a lock file: collect the pid of the active
161  * daemon and the file name of the active spool entry.
162  * Return boolean indicating existence of a lock file.
163  */
164 static int
165 lockchk(char *s)
166 {
167 	FILE *fp = NULL;
168 	int fd, i, n;
169 
170 	/* NOTE: lock file is owned by root, not the user. */
171 	PRIV_START;
172 	fd = safe_open(s, O_RDONLY|O_NOFOLLOW, 0);
173 	PRIV_END;
174 	if (fd < 0 || (fp = fdopen(fd, "r")) == NULL) {
175 		if (fd >= 0)
176 			close(fd);
177 		if (errno == EACCES)
178 			fatal("can't access lock file");
179 		else
180 			return(0);
181 	}
182 	if (!getline(fp)) {
183 		(void)fclose(fp);
184 		return(0);		/* no daemon present */
185 	}
186 	cur_daemon = atoi(line);
187 	if (kill(cur_daemon, 0) < 0 && errno != EPERM) {
188 		(void)fclose(fp);
189 		return(0);		/* no daemon present */
190 	}
191 	for (i = 1; (n = fread(current, sizeof(char), sizeof(current), fp)) <= 0; i++) {
192 		if (i > 5) {
193 			n = 1;
194 			break;
195 		}
196 		sleep(i);
197 	}
198 	current[n-1] = '\0';
199 	(void)fclose(fp);
200 	return(1);
201 }
202 
203 /*
204  * Process a control file.
205  */
206 void
207 process(char *file)
208 {
209 	FILE *cfp = NULL;
210 	int fd;
211 
212 	if (!chk(file))
213 		return;
214 	PRIV_START;
215 	fd = safe_open(file, O_RDONLY|O_NOFOLLOW, 0);
216 	PRIV_END;
217 	if (fd < 0 || (cfp = fdopen(fd, "r")) == NULL) {
218 		if (fd >= 0)
219 			close(fd);
220 		fatal("cannot open %s", file);
221 	}
222 	while (getline(cfp)) {
223 		switch (line[0]) {
224 		case 'U':  /* unlink associated files */
225 			if (strchr(line+1, '/') || strncmp(line+1, "df", 2))
226 				break;
227 			do_unlink(line+1);
228 		}
229 	}
230 	(void)fclose(cfp);
231 	do_unlink(file);
232 }
233 
234 static void
235 do_unlink(char *file)
236 {
237 	int	ret;
238 
239 	if (from != host)
240 		printf("%s: ", host);
241 	PRIV_START;
242 	ret = unlink(file);
243 	PRIV_END;
244 	printf(ret ? "cannot dequeue %s\n" : "%s dequeued\n", file);
245 }
246 
247 /*
248  * Do the dirty work in checking
249  */
250 int
251 chk(char *file)
252 {
253 	int *r, n, fd;
254 	char **u, *cp;
255 	FILE *cfp = NULL;
256 
257 	/*
258 	 * Check for valid cf file name (mostly checking current).
259 	 */
260 	if (strlen(file) < 7 || file[0] != 'c' || file[1] != 'f')
261 		return(0);
262 
263 	if (all && (from == host || !strcmp(from, file+6)))
264 		return(1);
265 
266 	/*
267 	 * get the owner's name from the control file.
268 	 */
269 	PRIV_START;
270 	fd = safe_open(file, O_RDONLY|O_NOFOLLOW, 0);
271 	PRIV_END;
272 	if (fd < 0 || (cfp = fdopen(fd, "r")) == NULL) {
273 		if (fd >= 0)
274 			close(fd);
275 		return(0);
276 	}
277 	while (getline(cfp)) {
278 		if (line[0] == 'P')
279 			break;
280 	}
281 	(void)fclose(cfp);
282 	if (line[0] != 'P')
283 		return(0);
284 
285 	if (users == 0 && requests == 0)
286 		return(!strcmp(file, current) && isowner(line+1, file));
287 	/*
288 	 * Check the request list
289 	 */
290 	for (n = 0, cp = file+3; isdigit(*cp); )
291 		n = n * 10 + (*cp++ - '0');
292 	for (r = requ; r < &requ[requests]; r++)
293 		if (*r == n && isowner(line+1, file))
294 			return(1);
295 	/*
296 	 * Check to see if it's in the user list
297 	 */
298 	for (u = user; u < &user[users]; u++)
299 		if (!strcmp(*u, line+1) && isowner(line+1, file))
300 			return(1);
301 	return(0);
302 }
303 
304 /*
305  * If root is removing a file on the local machine, allow it.
306  * If root is removing a file from a remote machine, only allow
307  * files sent from the remote machine to be removed.
308  * Normal users can only remove the file from where it was sent.
309  */
310 int
311 isowner(char *owner, char *file)
312 {
313 	if (!strcmp(person, root) && (from == host || !strcmp(from, file+6)))
314 		return(1);
315 	if (!strcmp(person, owner) && !strcmp(from, file+6))
316 		return(1);
317 	if (from != host)
318 		printf("%s: ", host);
319 	printf("%s: Permission denied\n", file);
320 	return(0);
321 }
322 
323 /*
324  * Check to see if we are sending files to a remote machine. If we are,
325  * then try removing files on the remote machine.
326  */
327 void
328 rmremote(void)
329 {
330 	char *cp;
331 	int i, rem;
332 	size_t n;
333 	char buf[BUFSIZ];
334 
335 	if (!remote)
336 		return;	/* not sending to a remote machine */
337 
338 	/*
339 	 * Flush stdout so the user can see what has been deleted
340 	 * while we wait (possibly) for the connection.
341 	 */
342 	fflush(stdout);
343 
344 	/* the trailing space will be replaced with a newline later */
345 	n = snprintf(buf, sizeof(buf), "\5%s %s ", RP, all ? "-all" : person);
346 	if (n == -1 || n >= sizeof(buf))
347 		goto bad;
348 	cp = buf + n;
349 	for (i = 0; i < users; i++) {
350 		n = strlcpy(cp, user[i], sizeof(buf) - (cp - buf + 1));
351 		if (n >= sizeof(buf) - (cp - buf + 1))
352 			goto bad;
353 		cp += n;
354 		*cp++ = ' ';
355 	}
356 	*cp = '\0';
357 	for (i = 0; i < requests; i++) {
358 		n = snprintf(cp, sizeof(buf) - (cp - buf), "%d ", requ[i]);
359 		if (n == -1 || n >= sizeof(buf) - (cp - buf))
360 			goto bad;
361 		cp += n;
362 	}
363 	cp[-1] = '\n';		/* replace space with newline, leave the NUL */
364 	rem = getport(RM, 0);
365 	if (rem < 0) {
366 		if (from != host)
367 			printf("%s: ", host);
368 		printf("connection to %s is down\n", RM);
369 	} else {
370 		struct sigaction osa, nsa;
371 
372 		memset(&nsa, 0, sizeof(nsa));
373 		nsa.sa_handler = alarmer;
374 		sigemptyset(&nsa.sa_mask);
375 		nsa.sa_flags = 0;
376 		(void)sigaction(SIGALRM, &nsa, &osa);
377 		alarm(wait_time);
378 
379 		i = strlen(buf);
380 		if (write(rem, buf, i) != i)
381 			fatal("Lost connection");
382 		while ((i = read(rem, buf, sizeof(buf))) > 0)
383 			(void)fwrite(buf, 1, i, stdout);
384 		alarm(0);
385 		(void)sigaction(SIGALRM, &osa, NULL);
386 		(void)close(rem);
387 	}
388 	return;
389 bad:
390 	printf("remote buffer too large\n");
391 	return;
392 }
393 
394 static void
395 alarmer(int s)
396 {
397 	/* nothing */
398 }
399 
400 /*
401  * Return 1 if the filename begins with 'cf'
402  */
403 int
404 iscf(struct dirent *d)
405 {
406 	return(d->d_name[0] == 'c' && d->d_name[1] == 'f');
407 }
408