xref: /netbsd-src/usr.sbin/lpr/common_source/rmjob.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: rmjob.c,v 1.13 1997/10/05 15:12:04 mrg 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 #include <sys/cdefs.h>
37 #ifndef lint
38 #if 0
39 static char sccsid[] = "@(#)rmjob.c	8.2 (Berkeley) 4/28/95";
40 #else
41 __RCSID("$NetBSD: rmjob.c,v 1.13 1997/10/05 15:12:04 mrg Exp $");
42 #endif
43 #endif /* not lint */
44 
45 #include <sys/param.h>
46 
47 #include <signal.h>
48 #include <errno.h>
49 #include <dirent.h>
50 #include <unistd.h>
51 #include <stdlib.h>
52 #include <stdio.h>
53 #include <string.h>
54 #include <ctype.h>
55 #include "lp.h"
56 #include "lp.local.h"
57 #include "pathnames.h"
58 
59 /*
60  * rmjob - remove the specified jobs from the queue.
61  */
62 
63 /*
64  * Stuff for handling lprm specifications
65  */
66 extern char	*user[];		/* users to process */
67 extern int	users;			/* # of users in user array */
68 extern int	requ[];			/* job number of spool entries */
69 extern int	requests;		/* # of spool requests */
70 extern char	*person;		/* name of person doing lprm */
71 
72 static char	root[] = "root";
73 static int	all = 0;		/* eliminate all files (root only) */
74 static int	cur_daemon;		/* daemon's pid */
75 static char	current[40];		/* active control file name */
76 
77 extern uid_t	uid, euid;		/* real and effective user id's */
78 
79 static	void	do_unlink __P((char *));
80 
81 void
82 rmjob()
83 {
84 	int i, nitems;
85 	int assasinated = 0;
86 	struct dirent **files;
87 	char *cp;
88 
89 	if ((i = cgetent(&bp, printcapdb, printer)) == -2)
90 		fatal("can't open printer description file");
91 	else if (i == -1)
92 		fatal("unknown printer");
93 	else if (i == -3)
94 		fatal("potential reference loop detected in printcap file");
95 	if (cgetstr(bp, "lp", &LP) < 0)
96 		LP = _PATH_DEFDEVLP;
97 	if (cgetstr(bp, "rp", &RP) < 0)
98 		RP = DEFLP;
99 	if (cgetstr(bp, "sd", &SD) < 0)
100 		SD = _PATH_DEFSPOOL;
101 	if (cgetstr(bp,"lo", &LO) < 0)
102 		LO = DEFLOCK;
103 	cgetstr(bp, "rm", &RM);
104 	if ((cp = checkremote()) != NULL)
105 		printf("Warning: %s\n", cp);
106 
107 	/*
108 	 * If the format was `lprm -' and the user isn't the super-user,
109 	 *  then fake things to look like he said `lprm user'.
110 	 */
111 	if (users < 0) {
112 		if (getuid() == 0)
113 			all = 1;	/* all files in local queue */
114 		else {
115 			user[0] = person;
116 			users = 1;
117 		}
118 	}
119 	if (!strcmp(person, "-all")) {
120 		if (from == host)
121 			fatal("The login name \"-all\" is reserved");
122 		all = 1;	/* all those from 'from' */
123 		person = root;
124 	}
125 
126 	seteuid(euid);
127 	if (chdir(SD) < 0)
128 		fatal("cannot chdir to spool directory");
129 	if ((nitems = scandir(".", &files, iscf, NULL)) < 0)
130 		fatal("cannot access spool directory");
131 	seteuid(uid);
132 
133 	if (nitems) {
134 		/*
135 		 * Check for an active printer daemon (in which case we
136 		 *  kill it if it is reading our file) then remove stuff
137 		 *  (after which we have to restart the daemon).
138 		 */
139 		if (lockchk(LO) && chk(current)) {
140 			seteuid(euid);
141 			assasinated = kill(cur_daemon, SIGINT) == 0;
142 			seteuid(uid);
143 			if (!assasinated)
144 				fatal("cannot kill printer daemon");
145 		}
146 		/*
147 		 * process the files
148 		 */
149 		for (i = 0; i < nitems; i++)
150 			process(files[i]->d_name);
151 	}
152 	rmremote();
153 	/*
154 	 * Restart the printer daemon if it was killed
155 	 */
156 	if (assasinated && !startdaemon(printer))
157 		fatal("cannot restart printer daemon\n");
158 	exit(0);
159 }
160 
161 /*
162  * Process a lock file: collect the pid of the active
163  *  daemon and the file name of the active spool entry.
164  * Return boolean indicating existence of a lock file.
165  */
166 int
167 lockchk(s)
168 	char *s;
169 {
170 	FILE *fp;
171 	int i, n;
172 
173 	seteuid(euid);
174 	if ((fp = fopen(s, "r")) == NULL) {
175 		if (errno == EACCES)
176 			fatal("can't access lock file");
177 		else
178 			return(0);
179 	}
180 	seteuid(uid);
181 	if (!getline(fp)) {
182 		(void)fclose(fp);
183 		return(0);		/* no daemon present */
184 	}
185 	cur_daemon = atoi(line);
186 	if (kill(cur_daemon, 0) < 0 && errno != EPERM) {
187 		(void)fclose(fp);
188 		return(0);		/* no daemon present */
189 	}
190 	for (i = 1; (n = fread(current, sizeof(char), sizeof(current), fp)) <= 0; i++) {
191 		if (i > 5) {
192 			n = 1;
193 			break;
194 		}
195 		sleep(i);
196 	}
197 	current[n-1] = '\0';
198 	(void)fclose(fp);
199 	return(1);
200 }
201 
202 /*
203  * Process a control file.
204  */
205 void
206 process(file)
207 	char *file;
208 {
209 	FILE *cfp;
210 
211 	if (!chk(file))
212 		return;
213 	seteuid(euid);
214 	if ((cfp = fopen(file, "r")) == NULL)
215 		fatal("cannot open %s", file);
216 	seteuid(uid);
217 	while (getline(cfp)) {
218 		switch (line[0]) {
219 		case 'U':  /* unlink associated files */
220 			if (strchr(line+1, '/') || strncmp(line+1, "df", 2))
221 				break;
222 			do_unlink(line+1);
223 		}
224 	}
225 	(void)fclose(cfp);
226 	do_unlink(file);
227 }
228 
229 static void
230 do_unlink(file)
231 	char *file;
232 {
233 	int	ret;
234 
235 	if (from != host)
236 		printf("%s: ", host);
237 	seteuid(euid);
238 	ret = unlink(file);
239 	seteuid(uid);
240 	printf(ret ? "cannot dequeue %s\n" : "%s dequeued\n", file);
241 }
242 
243 /*
244  * Do the dirty work in checking
245  */
246 int
247 chk(file)
248 	char *file;
249 {
250 	int *r, n;
251 	char **u, *cp;
252 	FILE *cfp;
253 
254 	/*
255 	 * Check for valid cf file name (mostly checking current).
256 	 */
257 	if (strlen(file) < 7 || file[0] != 'c' || file[1] != 'f')
258 		return(0);
259 
260 	if (all && (from == host || !strcmp(from, file+6)))
261 		return(1);
262 
263 	/*
264 	 * get the owner's name from the control file.
265 	 */
266 	seteuid(euid);
267 	if ((cfp = fopen(file, "r")) == NULL)
268 		return(0);
269 	seteuid(uid);
270 	while (getline(cfp)) {
271 		if (line[0] == 'P')
272 			break;
273 	}
274 	(void)fclose(cfp);
275 	if (line[0] != 'P')
276 		return(0);
277 
278 	if (users == 0 && requests == 0)
279 		return(!strcmp(file, current) && isowner(line+1, file));
280 	/*
281 	 * Check the request list
282 	 */
283 	for (n = 0, cp = file+3; isdigit(*cp); )
284 		n = n * 10 + (*cp++ - '0');
285 	for (r = requ; r < &requ[requests]; r++)
286 		if (*r == n && isowner(line+1, file))
287 			return(1);
288 	/*
289 	 * Check to see if it's in the user list
290 	 */
291 	for (u = user; u < &user[users]; u++)
292 		if (!strcmp(*u, line+1) && isowner(line+1, file))
293 			return(1);
294 	return(0);
295 }
296 
297 /*
298  * If root is removing a file on the local machine, allow it.
299  * If root is removing a file from a remote machine, only allow
300  * files sent from the remote machine to be removed.
301  * Normal users can only remove the file from where it was sent.
302  */
303 int
304 isowner(owner, file)
305 	char *owner, *file;
306 {
307 	if (!strcmp(person, root) && (from == host || !strcmp(from, file+6)))
308 		return(1);
309 	if (!strcmp(person, owner) && !strcmp(from, file+6))
310 		return(1);
311 	if (from != host)
312 		printf("%s: ", host);
313 	printf("%s: Permission denied\n", file);
314 	return(0);
315 }
316 
317 /*
318  * Check to see if we are sending files to a remote machine. If we are,
319  * then try removing files on the remote machine.
320  */
321 void
322 rmremote()
323 {
324 	char *cp, *s;
325 	int i, rem, len;
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 	/* \5 RP space all */
337 	len = 1 + strlen(RP) + 1 + strlen(all ? "-all" : person);
338 	for (i = 0; i < users; i++) {
339 		len += strlen(user[i]) + 1;
340 	}
341 	for (i = 0; i < requests; i++) {
342 		len += snprintf(line, sizeof(line), " %d", requ[i]);
343 	}
344 	/* newline nul */
345 	len += 2;
346 	if (len > sizeof(line))
347 		s = malloc(len);
348 	else
349 		s = line;
350 	cp = s;
351 
352 	cp += snprintf(s, len, "\5%s %s", RP, all ? "-all" : person);
353 	for (i = 0; i < users; i++) {
354 		*cp++ = ' ';
355 		strncpy(cp, user[i], len - (cp - s) - 2);
356 		cp += strlen(cp);
357 	}
358 	for (i = 0; i < requests; i++) {
359 		(void)snprintf(cp, len - (cp - s) - 1, " %d", requ[i]);
360 		cp += strlen(cp);
361 	}
362 	cp[0] = '\n';
363 	cp[1] = '\0';
364 
365 	rem = getport(RM, 0);
366 	if (rem < 0) {
367 		if (from != host)
368 			printf("%s: ", host);
369 		printf("connection to %s is down\n", RM);
370 	} else {
371 		if (write(rem, s, len) != len)
372 			fatal("Lost connection");
373 		if (len > sizeof(line))
374 			(void)free(s);
375 		while ((i = read(rem, line, sizeof(line))) > 0)
376 			(void)fwrite(line, 1, i, stdout);
377 		(void)close(rem);
378 	}
379 }
380 
381 /*
382  * Return 1 if the filename begins with 'cf'
383  */
384 int
385 iscf(d)
386 	struct dirent *d;
387 {
388 	return(d->d_name[0] == 'c' && d->d_name[1] == 'f');
389 }
390