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      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
     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
    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
    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
    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
    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
    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
    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
    371 alarmer(int s)
    372 {
    373 	/* nothing */
    374 }
    375 
    376 /*
    377  * Return 1 if the filename begins with 'cf'
    378  */
    379 int
    380 iscf(const struct dirent *d)
    381 {
    382 	return(d->d_name[0] == 'c' && d->d_name[1] == 'f');
    383 }
    384