xref: /openbsd-src/usr.sbin/lpr/common_source/rmjob.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: rmjob.c,v 1.9 1998/04/22 14:44:08 deraadt Exp $	*/
2 
3 /*
4  * Copyright (c) 1983, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)rmjob.c	8.2 (Berkeley) 4/28/95";
39 #else
40 static char rcsid[] = "$OpenBSD: rmjob.c,v 1.9 1998/04/22 14:44:08 deraadt Exp $";
41 #endif
42 #endif /* not lint */
43 
44 #include <sys/param.h>
45 
46 #include <signal.h>
47 #include <errno.h>
48 #include <dirent.h>
49 #include <unistd.h>
50 #include <stdlib.h>
51 #include <stdio.h>
52 #include <string.h>
53 #include <ctype.h>
54 #include "lp.h"
55 #include "lp.local.h"
56 #include "pathnames.h"
57 
58 /*
59  * rmjob - remove the specified jobs from the queue.
60  */
61 
62 /*
63  * Stuff for handling lprm specifications
64  */
65 extern char	*user[];		/* users to process */
66 extern int	users;			/* # of users in user array */
67 extern int	requ[];			/* job number of spool entries */
68 extern int	requests;		/* # of spool requests */
69 extern char	*person;		/* name of person doing lprm */
70 
71 static char	root[] = "root";
72 static int	all = 0;		/* eliminate all files (root only) */
73 static int	cur_daemon;		/* daemon's pid */
74 static char	current[40];		/* active control file name */
75 
76 extern uid_t	uid, euid;		/* real and effective user id's */
77 
78 static	void	do_unlink __P((char *));
79 
80 void
81 rmjob()
82 {
83 	register int i, nitems;
84 	int assasinated = 0;
85 	struct dirent **files;
86 	char *cp;
87 
88 	if ((i = cgetent(&bp, printcapdb, printer)) == -2)
89 		fatal("can't open printer description file");
90 	else if (i == -1)
91 		fatal("unknown printer");
92 	else if (i == -3)
93 		fatal("potential reference loop detected in printcap file");
94 	if (cgetstr(bp, "lp", &LP) < 0)
95 		LP = _PATH_DEFDEVLP;
96 	if (cgetstr(bp, "rp", &RP) < 0)
97 		RP = DEFLP;
98 	if (cgetstr(bp, "sd", &SD) < 0)
99 		SD = _PATH_DEFSPOOL;
100 	if (cgetstr(bp,"lo", &LO) < 0)
101 		LO = DEFLOCK;
102 	cgetstr(bp, "rm", &RM);
103 	if ((cp = checkremote()))
104 		printf("Warning: %s\n", cp);
105 
106 	/*
107 	 * If the format was `lprm -' and the user isn't the super-user,
108 	 *  then fake things to look like he said `lprm user'.
109 	 */
110 	if (users < 0) {
111 		if (getuid() == 0)
112 			all = 1;	/* all files in local queue */
113 		else {
114 			user[0] = person;
115 			users = 1;
116 		}
117 	}
118 	if (!strcmp(person, "-all")) {
119 		if (from == host)
120 			fatal("The login name \"-all\" is reserved");
121 		all = 1;	/* all those from 'from' */
122 		person = root;
123 	}
124 
125 	seteuid(euid);
126 	if (chdir(SD) < 0)
127 		fatal("cannot chdir to spool directory");
128 	if ((nitems = scandir(".", &files, iscf, NULL)) < 0)
129 		fatal("cannot access spool directory");
130 	seteuid(uid);
131 
132 	if (nitems) {
133 		/*
134 		 * Check for an active printer daemon (in which case we
135 		 *  kill it if it is reading our file) then remove stuff
136 		 *  (after which we have to restart the daemon).
137 		 */
138 		if (lockchk(LO) && chk(current)) {
139 			seteuid(euid);
140 			assasinated = kill(cur_daemon, SIGINT) == 0;
141 			seteuid(uid);
142 			if (!assasinated)
143 				fatal("cannot kill printer daemon");
144 		}
145 		/*
146 		 * process the files
147 		 */
148 		for (i = 0; i < nitems; i++)
149 			process(files[i]->d_name);
150 	}
151 	rmremote();
152 	/*
153 	 * Restart the printer daemon if it was killed
154 	 */
155 	if (assasinated && !startdaemon(printer))
156 		fatal("cannot restart printer daemon\n");
157 	exit(0);
158 }
159 
160 /*
161  * Process a lock file: collect the pid of the active
162  *  daemon and the file name of the active spool entry.
163  * Return boolean indicating existence of a lock file.
164  */
165 int
166 lockchk(s)
167 	char *s;
168 {
169 	register FILE *fp;
170 	register int i, n;
171 
172 	seteuid(euid);
173 	if ((fp = fopen(s, "r")) == NULL) {
174 		if (errno == EACCES)
175 			fatal("can't access lock file");
176 		else
177 			return(0);
178 	}
179 	seteuid(uid);
180 	if (!getline(fp)) {
181 		(void) fclose(fp);
182 		return(0);		/* no daemon present */
183 	}
184 	cur_daemon = atoi(line);
185 	if (kill(cur_daemon, 0) < 0 && errno != EPERM) {
186 		(void) fclose(fp);
187 		return(0);		/* no daemon present */
188 	}
189 	for (i = 1; (n = fread(current, sizeof(char), sizeof(current), fp)) <= 0; i++) {
190 		if (i > 5) {
191 			n = 1;
192 			break;
193 		}
194 		sleep(i);
195 	}
196 	current[n-1] = '\0';
197 	(void) fclose(fp);
198 	return(1);
199 }
200 
201 /*
202  * Process a control file.
203  */
204 void
205 process(file)
206 	char *file;
207 {
208 	FILE *cfp;
209 
210 	if (!chk(file))
211 		return;
212 	seteuid(euid);
213 	if ((cfp = fopen(file, "r")) == NULL)
214 		fatal("cannot open %s", file);
215 	seteuid(uid);
216 	while (getline(cfp)) {
217 		switch (line[0]) {
218 		case 'U':  /* unlink associated files */
219 			if (strchr(line+1, '/') || strncmp(line+1, "df", 2))
220 				break;
221 			do_unlink(line+1);
222 		}
223 	}
224 	(void) fclose(cfp);
225 	do_unlink(file);
226 }
227 
228 static void
229 do_unlink(file)
230 	char *file;
231 {
232 	int	ret;
233 
234 	if (from != host)
235 		printf("%s: ", host);
236 	seteuid(euid);
237 	ret = unlink(file);
238 	seteuid(uid);
239 	printf(ret ? "cannot dequeue %s\n" : "%s dequeued\n", file);
240 }
241 
242 /*
243  * Do the dirty work in checking
244  */
245 int
246 chk(file)
247 	char *file;
248 {
249 	register int *r, n;
250 	register char **u, *cp;
251 	FILE *cfp;
252 
253 	/*
254 	 * Check for valid cf file name (mostly checking current).
255 	 */
256 	if (strlen(file) < 7 || file[0] != 'c' || file[1] != 'f')
257 		return(0);
258 
259 	if (all && (from == host || !strcmp(from, file+6)))
260 		return(1);
261 
262 	/*
263 	 * get the owner's name from the control file.
264 	 */
265 	seteuid(euid);
266 	if ((cfp = fopen(file, "r")) == NULL)
267 		return(0);
268 	seteuid(uid);
269 	while (getline(cfp)) {
270 		if (line[0] == 'P')
271 			break;
272 	}
273 	(void) fclose(cfp);
274 	if (line[0] != 'P')
275 		return(0);
276 
277 	if (users == 0 && requests == 0)
278 		return(!strcmp(file, current) && isowner(line+1, file));
279 	/*
280 	 * Check the request list
281 	 */
282 	for (n = 0, cp = file+3; isdigit(*cp); )
283 		n = n * 10 + (*cp++ - '0');
284 	for (r = requ; r < &requ[requests]; r++)
285 		if (*r == n && isowner(line+1, file))
286 			return(1);
287 	/*
288 	 * Check to see if it's in the user list
289 	 */
290 	for (u = user; u < &user[users]; u++)
291 		if (!strcmp(*u, line+1) && isowner(line+1, file))
292 			return(1);
293 	return(0);
294 }
295 
296 /*
297  * If root is removing a file on the local machine, allow it.
298  * If root is removing a file from a remote machine, only allow
299  * files sent from the remote machine to be removed.
300  * Normal users can only remove the file from where it was sent.
301  */
302 int
303 isowner(owner, file)
304 	char *owner, *file;
305 {
306 	if (!strcmp(person, root) && (from == host || !strcmp(from, file+6)))
307 		return(1);
308 	if (!strcmp(person, owner) && !strcmp(from, file+6))
309 		return(1);
310 	if (from != host)
311 		printf("%s: ", host);
312 	printf("%s: Permission denied\n", file);
313 	return(0);
314 }
315 
316 /*
317  * Check to see if we are sending files to a remote machine. If we are,
318  * then try removing files on the remote machine.
319  */
320 void
321 rmremote()
322 {
323 	register char *cp;
324 	register int i, rem;
325 	char buf[BUFSIZ];
326 
327 	if (!remote)
328 		return;	/* not sending to a remote machine */
329 
330 	/*
331 	 * Flush stdout so the user can see what has been deleted
332 	 * while we wait (possibly) for the connection.
333 	 */
334 	fflush(stdout);
335 
336 	(void)snprintf(buf, sizeof(buf)-2, "\5%s %s", RP, all ? "-all" : person);
337 	cp = buf + strlen(buf);
338 	for (i = 0; i < users && cp-buf+1+strlen(user[i]) < sizeof buf - 2; i++) {
339 		cp += strlen(cp);
340 		*cp++ = ' ';
341 		strcpy(cp, user[i]);
342 	}
343 	for (i = 0; i < requests && cp-buf+10 < sizeof(buf) - 2; i++) {
344 		cp += strlen(cp);
345 		(void) sprintf(cp, " %d", requ[i]);
346 	}
347 	strcat(cp, "\n");
348 	rem = getport(RM, 0);
349 	if (rem < 0) {
350 		if (from != host)
351 			printf("%s: ", host);
352 		printf("connection to %s is down\n", RM);
353 	} else {
354 		i = strlen(buf);
355 		if (write(rem, buf, i) != i)
356 			fatal("Lost connection");
357 		while ((i = read(rem, buf, sizeof(buf))) > 0)
358 			(void) fwrite(buf, 1, i, stdout);
359 		(void) close(rem);
360 	}
361 }
362 
363 /*
364  * Return 1 if the filename begins with 'cf'
365  */
366 int
367 iscf(d)
368 	struct dirent *d;
369 {
370 	return(d->d_name[0] == 'c' && d->d_name[1] == 'f');
371 }
372