xref: /netbsd-src/usr.sbin/lpr/common_source/rmjob.c (revision 7027866a09786f44d29080aa3a48badc640ddfe2)
1 /*	$NetBSD: rmjob.c,v 1.25 2009/07/13 19:05:41 roy 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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)rmjob.c	8.2 (Berkeley) 4/28/95";
36 #else
37 __RCSID("$NetBSD: rmjob.c,v 1.25 2009/07/13 19:05:41 roy Exp $");
38 #endif
39 #endif /* not lint */
40 
41 #include <sys/param.h>
42 
43 #include <signal.h>
44 #include <errno.h>
45 #include <dirent.h>
46 #include <unistd.h>
47 #include <stdlib.h>
48 #include <stdio.h>
49 #include <string.h>
50 #include <ctype.h>
51 #include "lp.h"
52 #include "lp.local.h"
53 #include "pathnames.h"
54 
55 /*
56  * rmjob - remove the specified jobs from the queue.
57  */
58 
59 /*
60  * Stuff for handling lprm specifications
61  */
62 extern char	*user[];		/* users to process */
63 extern int	users;			/* # of users in user array */
64 extern int	requ[];			/* job number of spool entries */
65 extern int	requests;		/* # of spool requests */
66 extern char	*person;		/* name of person doing lprm */
67 
68 static char	root[] = "root";
69 static int	all = 0;		/* eliminate all files (root only) */
70 static int	cur_daemon;		/* daemon's pid */
71 static char	current[40];		/* active control file name */
72 
73 extern uid_t	uid, euid;		/* real and effective user id's */
74 
75 static	void	do_unlink(const char *);
76 static	void	alarmer(int);
77 
78 void
rmjob(void)79 rmjob(void)
80 {
81 	int i, nitems;
82 	int assasinated = 0;
83 	struct dirent **files;
84 
85 	getprintcap(printer);
86 
87 	/*
88 	 * If the format was `lprm -' and the user isn't the super-user,
89 	 *  then fake things to look like he said `lprm user'.
90 	 */
91 	if (users < 0) {
92 		if (getuid() == 0)
93 			all = 1;	/* all files in local queue */
94 		else {
95 			user[0] = person;
96 			users = 1;
97 		}
98 	}
99 	if (!strcmp(person, "-all")) {
100 		if (from == host)
101 			fatal("The login name \"-all\" is reserved");
102 		all = 1;	/* all those from 'from' */
103 		person = root;
104 	}
105 
106 	seteuid(euid);
107 	if (chdir(SD) < 0)
108 		fatal("cannot chdir to spool directory");
109 	if ((nitems = scandir(".", &files, iscf, NULL)) < 0)
110 		fatal("cannot access spool directory");
111 	seteuid(uid);
112 
113 	if (nitems) {
114 		/*
115 		 * Check for an active printer daemon (in which case we
116 		 *  kill it if it is reading our file) then remove stuff
117 		 *  (after which we have to restart the daemon).
118 		 */
119 		if (lockchk(LO) && chk(current)) {
120 			seteuid(euid);
121 			assasinated = kill(cur_daemon, SIGINT) == 0;
122 			seteuid(uid);
123 			if (!assasinated)
124 				fatal("cannot kill printer daemon");
125 		}
126 		/*
127 		 * process the files
128 		 */
129 		for (i = 0; i < nitems; i++)
130 			process(files[i]->d_name);
131 	}
132 	rmremote();
133 	/*
134 	 * Restart the printer daemon if it was killed
135 	 */
136 	if (assasinated && !startdaemon(printer))
137 		fatal("cannot restart printer daemon\n");
138 	exit(0);
139 }
140 
141 /*
142  * Process a lock file: collect the pid of the active
143  *  daemon and the file name of the active spool entry.
144  * Return boolean indicating existence of a lock file.
145  */
146 int
lockchk(const char * s)147 lockchk(const char *s)
148 {
149 	FILE *fp;
150 	int i, n;
151 
152 	seteuid(euid);
153 	if ((fp = fopen(s, "r")) == NULL) {
154 		if (errno == EACCES)
155 			fatal("can't access lock file");
156 		else
157 			return(0);
158 	}
159 	seteuid(uid);
160 	if (!get_line(fp)) {
161 		(void)fclose(fp);
162 		return(0);		/* no daemon present */
163 	}
164 	cur_daemon = atoi(line);
165 	if (kill(cur_daemon, 0) < 0 && errno != EPERM) {
166 		(void)fclose(fp);
167 		return(0);		/* no daemon present */
168 	}
169 	for (i = 1; (n = fread(current, sizeof(char), sizeof(current), fp)) <= 0; i++) {
170 		if (i > 5) {
171 			n = 1;
172 			break;
173 		}
174 		sleep((size_t)i);
175 	}
176 	current[n-1] = '\0';
177 	(void)fclose(fp);
178 	return(1);
179 }
180 
181 /*
182  * Process a control file.
183  */
184 void
process(const char * file)185 process(const char *file)
186 {
187 	FILE *cfp;
188 
189 	if (!chk(file))
190 		return;
191 	seteuid(euid);
192 	if ((cfp = fopen(file, "r")) == NULL)
193 		fatal("cannot open %s", file);
194 	seteuid(uid);
195 	while (get_line(cfp)) {
196 		switch (line[0]) {
197 		case 'U':  /* unlink associated files */
198 			if (strchr(line+1, '/') || strncmp(line+1, "df", 2))
199 				break;
200 			do_unlink(line+1);
201 		}
202 	}
203 	(void)fclose(cfp);
204 	do_unlink(file);
205 }
206 
207 static void
do_unlink(const char * file)208 do_unlink(const char *file)
209 {
210 	int	ret;
211 
212 	if (from != host)
213 		printf("%s: ", host);
214 	seteuid(euid);
215 	ret = unlink(file);
216 	seteuid(uid);
217 	printf(ret ? "cannot dequeue %s\n" : "%s dequeued\n", file);
218 }
219 
220 /*
221  * Do the dirty work in checking
222  */
223 int
chk(const char * file)224 chk(const char *file)
225 {
226 	int *r, n;
227 	char **u;
228 	const char *cp;
229 	FILE *cfp;
230 
231 	/*
232 	 * Check for valid cf file name (mostly checking current).
233 	 */
234 	if (strlen(file) < 7 || file[0] != 'c' || file[1] != 'f')
235 		return(0);
236 
237 	if (all && (from == host || !strcmp(from, file+6)))
238 		return(1);
239 
240 	/*
241 	 * get the owner's name from the control file.
242 	 */
243 	seteuid(euid);
244 	if ((cfp = fopen(file, "r")) == NULL)
245 		return(0);
246 	seteuid(uid);
247 	while (get_line(cfp)) {
248 		if (line[0] == 'P')
249 			break;
250 	}
251 	(void)fclose(cfp);
252 	if (line[0] != 'P')
253 		return(0);
254 
255 	if (users == 0 && requests == 0)
256 		return(!strcmp(file, current) && isowner(line+1, file));
257 	/*
258 	 * Check the request list
259 	 */
260 	for (n = 0, cp = file+3; isdigit((unsigned char)*cp); )
261 		n = n * 10 + (*cp++ - '0');
262 	for (r = requ; r < &requ[requests]; r++)
263 		if (*r == n && isowner(line+1, file))
264 			return(1);
265 	/*
266 	 * Check to see if it's in the user list
267 	 */
268 	for (u = user; u < &user[users]; u++)
269 		if (!strcmp(*u, line+1) && isowner(line+1, file))
270 			return(1);
271 	return(0);
272 }
273 
274 /*
275  * If root is removing a file on the local machine, allow it.
276  * If root is removing a file from a remote machine, only allow
277  * files sent from the remote machine to be removed.
278  * Normal users can only remove the file from where it was sent.
279  */
280 int
isowner(const char * owner,const char * file)281 isowner(const char *owner, const char *file)
282 {
283 	if (!strcmp(person, root) && (from == host || !strcmp(from, file+6)))
284 		return(1);
285 	if (!strcmp(person, owner) && !strcmp(from, file+6))
286 		return(1);
287 	if (from != host)
288 		printf("%s: ", host);
289 	printf("%s: Permission denied\n", file);
290 	return(0);
291 }
292 
293 /*
294  * Check to see if we are sending files to a remote machine. If we are,
295  * then try removing files on the remote machine.
296  */
297 void
rmremote(void)298 rmremote(void)
299 {
300 	char *cp, *s;
301 	int i, rem;
302 	size_t len;
303 
304 	if (!remote)
305 		return;	/* not sending to a remote machine */
306 
307 	/*
308 	 * Flush stdout so the user can see what has been deleted
309 	 * while we wait (possibly) for the connection.
310 	 */
311 	fflush(stdout);
312 
313 	/* \5 RP space all */
314 	len = 1 + strlen(RP) + 1 + strlen(all ? "-all" : person);
315 	for (i = 0; i < users; i++) {
316 		len += strlen(user[i]) + 1;
317 	}
318 	for (i = 0; i < requests; i++) {
319 		len += snprintf(line, sizeof(line), " %d", requ[i]);
320 	}
321 	/* newline nul */
322 	len += 2;
323 	if (len > sizeof(line))
324 		s = malloc(len);
325 	else
326 		s = line;
327 	cp = s;
328 
329 	cp += snprintf(s, len, "\5%s %s", RP, all ? "-all" : person);
330 	for (i = 0; i < users; i++) {
331 		*cp++ = ' ';
332 		strncpy(cp, user[i], len - (cp - s) - 2);
333 		cp += strlen(cp);
334 	}
335 	for (i = 0; i < requests; i++) {
336 		(void)snprintf(cp, len - (cp - s) - 1, " %d", requ[i]);
337 		cp += strlen(cp);
338 	}
339 	cp[0] = '\n';
340 	cp[1] = '\0';
341 
342 	rem = getport(RM);
343 	if (rem < 0) {
344 		if (from != host)
345 			printf("%s: ", host);
346 		printf("connection to %s is down\n", RM);
347 	} else {
348 		struct sigaction osa, nsa;
349 
350 		if ((size_t)write(rem, s, len) != len)
351 			fatal("Lost connection");
352 		if (len > sizeof(line))
353 			(void)free(s);
354 		nsa.sa_handler = alarmer;
355 		sigemptyset(&nsa.sa_mask);
356 		sigaddset(&nsa.sa_mask, SIGALRM);
357 		nsa.sa_flags = 0;
358 		(void)sigaction(SIGALRM, &nsa, &osa);
359 		alarm(wait_time);
360 		while ((i = read(rem, line, sizeof(line))) > 0) {
361 			(void)fwrite(line, 1, (size_t)i, stdout);
362 			alarm(wait_time);
363 		}
364 		alarm(0);
365 		(void)sigaction(SIGALRM, &osa, NULL);
366 		(void)close(rem);
367 	}
368 }
369 
370 static void
alarmer(int s)371 alarmer(int s)
372 {
373 	/* nothing */
374 }
375 
376 /*
377  * Return 1 if the filename begins with 'cf'
378  */
379 int
iscf(const struct dirent * d)380 iscf(const struct dirent *d)
381 {
382 	return(d->d_name[0] == 'c' && d->d_name[1] == 'f');
383 }
384