xref: /freebsd/usr.sbin/lpr/common_source/rmjob.c (revision 9a14aa017b21c292740c00ee098195cd46642730)
1 /*
2  * Copyright (c) 1983, 1993
3  *	The Regents of the University of California.  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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if 0
31 #ifndef lint
32 static char sccsid[] = "@(#)rmjob.c	8.2 (Berkeley) 4/28/95";
33 #endif /* not lint */
34 #endif
35 
36 #include "lp.cdefs.h"		/* A cross-platform version of <sys/cdefs.h> */
37 __FBSDID("$FreeBSD$");
38 
39 #include <sys/param.h>
40 #include <sys/uio.h>
41 
42 #include <ctype.h>
43 #include <dirent.h>
44 #include <errno.h>
45 #include <signal.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #define psignal foil_gcc_psignal
50 #define	sys_siglist foil_gcc_siglist
51 #include <unistd.h>
52 #undef psignal
53 #undef sys_siglist
54 
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 static char	root[] = "root";
67 static int	all = 0;		/* eliminate all files (root only) */
68 static int	cur_daemon;		/* daemon's pid */
69 static char	current[7+MAXHOSTNAMELEN];  /* active control file name */
70 
71 extern uid_t	uid, euid;		/* real and effective user id's */
72 
73 static	void	alarmhandler(int _signo);
74 static	void	do_unlink(char *_file);
75 static int	 isowner(char *_owner, char *_file, const char *_cfhost);
76 
77 void
78 rmjob(const char *printer)
79 {
80 	register int i, nitems;
81 	int assassinated = 0;
82 	struct dirent **files;
83 	char *cp;
84 	struct printer myprinter, *pp = &myprinter;
85 
86 	init_printer(pp);
87 	if ((i = getprintcap(printer, pp)) < 0)
88 		fatal(pp, "getprintcap: %s", pcaperr(i));
89 	if ((cp = checkremote(pp))) {
90 		printf("Warning: %s\n", cp);
91 		free(cp);
92 	}
93 
94 	/*
95 	 * If the format was `lprm -' and the user isn't the super-user,
96 	 *  then fake things to look like he said `lprm user'.
97 	 */
98 	if (users < 0) {
99 		if (getuid() == 0)
100 			all = 1;	/* all files in local queue */
101 		else {
102 			user[0] = person;
103 			users = 1;
104 		}
105 	}
106 	if (!strcmp(person, "-all")) {
107 		if (from_host == local_host)
108 			fatal(pp, "The login name \"-all\" is reserved");
109 		all = 1;	/* all those from 'from_host' */
110 		person = root;
111 	}
112 
113 	seteuid(euid);
114 	if (chdir(pp->spool_dir) < 0)
115 		fatal(pp, "cannot chdir to spool directory");
116 	if ((nitems = scandir(".", &files, iscf, NULL)) < 0)
117 		fatal(pp, "cannot access spool directory");
118 	seteuid(uid);
119 
120 	if (nitems) {
121 		/*
122 		 * Check for an active printer daemon (in which case we
123 		 *  kill it if it is reading our file) then remove stuff
124 		 *  (after which we have to restart the daemon).
125 		 */
126 		if (lockchk(pp, pp->lock_file) && chk(current)) {
127 			seteuid(euid);
128 			assassinated = kill(cur_daemon, SIGINT) == 0;
129 			seteuid(uid);
130 			if (!assassinated)
131 				fatal(pp, "cannot kill printer daemon");
132 		}
133 		/*
134 		 * process the files
135 		 */
136 		for (i = 0; i < nitems; i++)
137 			process(pp, files[i]->d_name);
138 	}
139 	rmremote(pp);
140 	/*
141 	 * Restart the printer daemon if it was killed
142 	 */
143 	if (assassinated && !startdaemon(pp))
144 		fatal(pp, "cannot restart printer daemon\n");
145 	exit(0);
146 }
147 
148 /*
149  * Process a lock file: collect the pid of the active
150  *  daemon and the file name of the active spool entry.
151  * Return boolean indicating existence of a lock file.
152  */
153 int
154 lockchk(struct printer *pp, char *slockf)
155 {
156 	register FILE *fp;
157 	register int i, n;
158 
159 	seteuid(euid);
160 	if ((fp = fopen(slockf, "r")) == NULL) {
161 		if (errno == EACCES)
162 			fatal(pp, "%s: %s", slockf, strerror(errno));
163 		else
164 			return(0);
165 	}
166 	seteuid(uid);
167 	if (!getline(fp)) {
168 		(void) fclose(fp);
169 		return(0);		/* no daemon present */
170 	}
171 	cur_daemon = atoi(line);
172 	if (kill(cur_daemon, 0) < 0 && errno != EPERM) {
173 		(void) fclose(fp);
174 		return(0);		/* no daemon present */
175 	}
176 	for (i = 1; (n = fread(current, sizeof(char), sizeof(current), fp)) <= 0; i++) {
177 		if (i > 5) {
178 			n = 1;
179 			break;
180 		}
181 		sleep(i);
182 	}
183 	current[n-1] = '\0';
184 	(void) fclose(fp);
185 	return(1);
186 }
187 
188 /*
189  * Process a control file.
190  */
191 void
192 process(const struct printer *pp, char *file)
193 {
194 	FILE *cfp;
195 
196 	if (!chk(file))
197 		return;
198 	seteuid(euid);
199 	if ((cfp = fopen(file, "r")) == NULL)
200 		fatal(pp, "cannot open %s", file);
201 	seteuid(uid);
202 	while (getline(cfp)) {
203 		switch (line[0]) {
204 		case 'U':  /* unlink associated files */
205 			if (strchr(line+1, '/') || strncmp(line+1, "df", 2))
206 				break;
207 			do_unlink(line+1);
208 		}
209 	}
210 	(void) fclose(cfp);
211 	do_unlink(file);
212 }
213 
214 static void
215 do_unlink(char *file)
216 {
217 	int	ret;
218 
219 	if (from_host != local_host)
220 		printf("%s: ", local_host);
221 	seteuid(euid);
222 	ret = unlink(file);
223 	seteuid(uid);
224 	printf(ret ? "cannot dequeue %s\n" : "%s dequeued\n", file);
225 }
226 
227 /*
228  * Do the dirty work in checking
229  */
230 int
231 chk(char *file)
232 {
233 	int *r, jnum;
234 	char **u;
235 	const char *cfhost;
236 	FILE *cfp;
237 
238 	/*
239 	 * Check for valid cf file name (mostly checking current).
240 	 */
241 	if (strlen(file) < 7 || file[0] != 'c' || file[1] != 'f')
242 		return(0);
243 
244 	jnum = calc_jobnum(file, &cfhost);
245 	if (all && (from_host == local_host || !strcmp(from_host, cfhost)))
246 		return(1);
247 
248 	/*
249 	 * get the owner's name from the control file.
250 	 */
251 	seteuid(euid);
252 	if ((cfp = fopen(file, "r")) == NULL)
253 		return(0);
254 	seteuid(uid);
255 	while (getline(cfp)) {
256 		if (line[0] == 'P')
257 			break;
258 	}
259 	(void) fclose(cfp);
260 	if (line[0] != 'P')
261 		return(0);
262 
263 	if (users == 0 && requests == 0)
264 		return(!strcmp(file, current) && isowner(line+1, file, cfhost));
265 	/*
266 	 * Check the request list
267 	 */
268 	for (r = requ; r < &requ[requests]; r++)
269 		if (*r == jnum && isowner(line+1, file, cfhost))
270 			return(1);
271 	/*
272 	 * Check to see if it's in the user list
273 	 */
274 	for (u = user; u < &user[users]; u++)
275 		if (!strcmp(*u, line+1) && isowner(line+1, file, cfhost))
276 			return(1);
277 	return(0);
278 }
279 
280 /*
281  * If root is removing a file on the local machine, allow it.
282  * If root is removing a file from a remote machine, only allow
283  * files sent from the remote machine to be removed.
284  * Normal users can only remove the file from where it was sent.
285  */
286 static int
287 isowner(char *owner, char *file, const char *cfhost)
288 {
289 	if (!strcmp(person, root) && (from_host == local_host ||
290 	    !strcmp(from_host, cfhost)))
291 		return (1);
292 	if (!strcmp(person, owner) && !strcmp(from_host, cfhost))
293 		return (1);
294 	if (from_host != local_host)
295 		printf("%s: ", local_host);
296 	printf("%s: Permission denied\n", file);
297 	return(0);
298 }
299 
300 /*
301  * Check to see if we are sending files to a remote machine. If we are,
302  * then try removing files on the remote machine.
303  */
304 void
305 rmremote(const struct printer *pp)
306 {
307 	int i, elem, firstreq, niov, rem, totlen;
308 	char buf[BUFSIZ];
309 	void (*savealrm)(int);
310 	struct iovec *iov;
311 
312 	if (!pp->remote)
313 		return;	/* not sending to a remote machine */
314 
315 	/*
316 	 * Flush stdout so the user can see what has been deleted
317 	 * while we wait (possibly) for the connection.
318 	 */
319 	fflush(stdout);
320 
321 	/*
322 	 * Counting:
323 	 *	4 == "\5" + remote_queue + " " + person
324 	 *	2 * users == " " + user[i] for each user
325 	 *	requests == asprintf results for each request
326 	 *	1 == "\n"
327 	 * Although laborious, doing it this way makes it possible for
328 	 * us to process requests of indeterminate length without
329 	 * applying an arbitrary limit.  Arbitrary Limits Are Bad (tm).
330 	 */
331 	if (users > 0)
332 		niov = 4 + 2 * users + requests + 1;
333 	else
334 		niov = 4 + requests + 1;
335 	iov = malloc(niov * sizeof *iov);
336 	if (iov == 0)
337 		fatal(pp, "out of memory in rmremote()");
338 	iov[0].iov_base = "\5";
339 	iov[1].iov_base = pp->remote_queue;
340 	iov[2].iov_base = " ";
341 	iov[3].iov_base = all ? "-all" : person;
342 	elem = 4;
343 	for (i = 0; i < users; i++) {
344 		iov[elem].iov_base = " ";
345 		iov[elem + 1].iov_base = user[i];
346 		elem += 2;
347 	}
348 	firstreq = elem;
349 	for (i = 0; i < requests; i++) {
350 		asprintf((char **)&iov[elem].iov_base, " %d", requ[i]);
351 		if (iov[elem].iov_base == 0)
352 			fatal(pp, "out of memory in rmremote()");
353 		elem++;
354 	}
355 	iov[elem++].iov_base = "\n";
356 	for (totlen = i = 0; i < niov; i++)
357 		totlen += (iov[i].iov_len = strlen(iov[i].iov_base));
358 
359 	savealrm = signal(SIGALRM, alarmhandler);
360 	alarm(pp->conn_timeout);
361 	rem = getport(pp, pp->remote_host, 0);
362 	(void)signal(SIGALRM, savealrm);
363 	if (rem < 0) {
364 		if (from_host != local_host)
365 			printf("%s: ", local_host);
366 		printf("connection to %s is down\n", pp->remote_host);
367 	} else {
368 		if (writev(rem, iov, niov) != totlen)
369 			fatal(pp, "Lost connection");
370 		while ((i = read(rem, buf, sizeof(buf))) > 0)
371 			(void) fwrite(buf, 1, i, stdout);
372 		(void) close(rem);
373 	}
374 	for (i = 0; i < requests; i++)
375 		free(iov[firstreq + i].iov_base);
376 	free(iov);
377 }
378 
379 /*
380  * Return 1 if the filename begins with 'cf'
381  */
382 int
383 iscf(const struct dirent *d)
384 {
385 	return(d->d_name[0] == 'c' && d->d_name[1] == 'f');
386 }
387 
388 void
389 alarmhandler(int signo __unused)
390 {
391 	/* the signal is ignored */
392 	/* (the '__unused' is just to avoid a compile-time warning) */
393 }
394