xref: /freebsd/usr.sbin/lpr/lpd/recvjob.c (revision f540a43052c12c76d3453ead881248d5467a1ab0)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1983, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 static const char copyright[] =
35 "@(#) Copyright (c) 1983, 1993\n\
36 	The Regents of the University of California.  All rights reserved.\n";
37 #endif /* not lint */
38 
39 #if 0
40 #ifndef lint
41 static char sccsid[] = "@(#)recvjob.c	8.2 (Berkeley) 4/27/95";
42 #endif /* not lint */
43 #endif
44 
45 #include "lp.cdefs.h"		/* A cross-platform version of <sys/cdefs.h> */
46 __FBSDID("$FreeBSD$");
47 
48 /*
49  * Receive printer jobs from the network, queue them and
50  * start the printer daemon.
51  */
52 #include <sys/param.h>
53 #include <sys/mount.h>
54 #include <sys/stat.h>
55 
56 #include <unistd.h>
57 #include <signal.h>
58 #include <fcntl.h>
59 #include <dirent.h>
60 #include <errno.h>
61 #include <syslog.h>
62 #include <stdio.h>
63 #include <stdlib.h>
64 #include <string.h>
65 #include "lp.h"
66 #include "lp.local.h"
67 #include "ctlinfo.h"
68 #include "extern.h"
69 #include "pathnames.h"
70 
71 #define ack()	(void) write(STDOUT_FILENO, sp, (size_t)1)
72 
73 /*
74  * The buffer size to use when reading/writing spool files.
75  */
76 #define	SPL_BUFSIZ	BUFSIZ
77 
78 static char	 dfname[NAME_MAX];	/* data files */
79 static int	 minfree;       /* keep at least minfree blocks available */
80 static const char	*sp = "";
81 static char	 tfname[NAME_MAX];	/* tmp copy of cf before linking */
82 
83 static int	 chksize(int _size);
84 static void	 frecverr(const char *_msg, ...) __printf0like(1, 2);
85 static int	 noresponse(void);
86 static void	 rcleanup(int _signo);
87 static int	 read_number(const char *_fn);
88 static int	 readfile(struct printer *_pp, char *_file, size_t _size);
89 static int	 readjob(struct printer *_pp);
90 
91 
92 void
93 recvjob(const char *printer)
94 {
95 	struct stat stb;
96 	int status;
97 	struct printer myprinter, *pp = &myprinter;
98 
99 	/*
100 	 * Perform lookup for printer name or abbreviation
101 	 */
102 	init_printer(pp);
103 	status = getprintcap(printer, pp);
104 	switch (status) {
105 	case PCAPERR_OSERR:
106 		frecverr("cannot open printer description file");
107 		break;
108 	case PCAPERR_NOTFOUND:
109 		frecverr("unknown printer %s", printer);
110 		break;
111 	case PCAPERR_TCLOOP:
112 		fatal(pp, "potential reference loop detected in printcap file");
113 	default:
114 		break;
115 	}
116 
117 	(void) close(STDERR_FILENO);			/* set up log file */
118 	if (open(pp->log_file, O_WRONLY|O_APPEND, 0664) < 0) {
119 		syslog(LOG_ERR, "%s: %m", pp->log_file);
120 		(void) open(_PATH_DEVNULL, O_WRONLY);
121 	}
122 
123 	if (chdir(pp->spool_dir) < 0)
124 		frecverr("%s: chdir(%s): %s", pp->printer, pp->spool_dir,
125 		    strerror(errno));
126 	if (stat(pp->lock_file, &stb) == 0) {
127 		if (stb.st_mode & 010) {
128 			/* queue is disabled */
129 			putchar('\1');		/* return error code */
130 			exit(1);
131 		}
132 	} else if (stat(pp->spool_dir, &stb) < 0)
133 		frecverr("%s: stat(%s): %s", pp->printer, pp->spool_dir,
134 		    strerror(errno));
135 	minfree = 2 * read_number("minfree");	/* scale KB to 512 blocks */
136 	signal(SIGTERM, rcleanup);
137 	signal(SIGPIPE, rcleanup);
138 
139 	if (readjob(pp))
140 		printjob(pp);
141 }
142 
143 /*
144  * Read printer jobs sent by lpd and copy them to the spooling directory.
145  * Return the number of jobs successfully transferred.
146  */
147 static int
148 readjob(struct printer *pp)
149 {
150 	register int size;
151 	int cfcnt, dfcnt;
152 	char *cp, *clastp, *errmsg;
153 	char givenid[32], givenhost[MAXHOSTNAMELEN];
154 
155 	ack();
156 	cfcnt = 0;
157 	dfcnt = 0;
158 	for (;;) {
159 		/*
160 		 * Read a command to tell us what to do
161 		 */
162 		cp = line;
163 		clastp = line + sizeof(line) - 1;
164 		do {
165 			size = read(STDOUT_FILENO, cp, (size_t)1);
166 			if (size != (ssize_t)1) {
167 				if (size < (ssize_t)0) {
168 					frecverr("%s: lost connection",
169 					    pp->printer);
170 					/*NOTREACHED*/
171 				}
172 				return (cfcnt);
173 			}
174 		} while ((*cp++ != '\n') && (cp <= clastp));
175 		if (cp > clastp) {
176 			frecverr("%s: readjob overflow", pp->printer);
177 			/*NOTREACHED*/
178 		}
179 		*--cp = '\0';
180 		cp = line;
181 		switch (*cp++) {
182 		case '\1':	/* cleanup because data sent was bad */
183 			rcleanup(0);
184 			continue;
185 
186 		case '\2':	/* read cf file */
187 			size = 0;
188 			dfcnt = 0;
189 			while (*cp >= '0' && *cp <= '9')
190 				size = size * 10 + (*cp++ - '0');
191 			if (*cp++ != ' ')
192 				break;
193 			/*
194 			 * host name has been authenticated, we use our
195 			 * view of the host name since we may be passed
196 			 * something different than what gethostbyaddr()
197 			 * returns
198 			 */
199 			strlcpy(cp + 6, from_host, sizeof(line)
200 			    + (size_t)(line - cp - 6));
201 			if (strchr(cp, '/')) {
202 				frecverr("readjob: %s: illegal path name", cp);
203 				/*NOTREACHED*/
204 			}
205 			strlcpy(tfname, cp, sizeof(tfname));
206 			tfname[sizeof (tfname) - 1] = '\0';
207 			tfname[0] = 't';
208 			if (!chksize(size)) {
209 				(void) write(STDOUT_FILENO, "\2", (size_t)1);
210 				continue;
211 			}
212 			if (!readfile(pp, tfname, (size_t)size)) {
213 				rcleanup(0);
214 				continue;
215 			}
216 			errmsg = ctl_renametf(pp->printer, tfname);
217 			tfname[0] = '\0';
218 			if (errmsg != NULL) {
219 				frecverr("%s: %s", pp->printer, errmsg);
220 				/*NOTREACHED*/
221 			}
222 			cfcnt++;
223 			continue;
224 
225 		case '\3':	/* read df file */
226 			*givenid = '\0';
227 			*givenhost = '\0';
228 			size = 0;
229 			while (*cp >= '0' && *cp <= '9')
230 				size = size * 10 + (*cp++ - '0');
231 			if (*cp++ != ' ')
232 				break;
233 			if (strchr(cp, '/')) {
234 				frecverr("readjob: %s: illegal path name", cp);
235 				/*NOTREACHED*/
236 			}
237 			if (!chksize(size)) {
238 				(void) write(STDOUT_FILENO, "\2", (size_t)1);
239 				continue;
240 			}
241 			strlcpy(dfname, cp, sizeof(dfname));
242 			dfcnt++;
243 			trstat_init(pp, dfname, dfcnt);
244 			(void) readfile(pp, dfname, (size_t)size);
245 			trstat_write(pp, TR_RECVING, (size_t)size, givenid,
246 			    from_host, givenhost);
247 			continue;
248 		}
249 		frecverr("protocol screwup: %s", line);
250 		/*NOTREACHED*/
251 	}
252 }
253 
254 /*
255  * Read files send by lpd and copy them to the spooling directory.
256  */
257 static int
258 readfile(struct printer *pp, char *file, size_t size)
259 {
260 	register char *cp;
261 	char buf[SPL_BUFSIZ];
262 	size_t amt, i;
263 	int err, fd, j;
264 
265 	fd = open(file, O_CREAT|O_EXCL|O_WRONLY, FILMOD);
266 	if (fd < 0) {
267 		frecverr("%s: readfile: error on open(%s): %s",
268 			 pp->printer, file, strerror(errno));
269 		/*NOTREACHED*/
270 	}
271 	ack();
272 	err = 0;
273 	for (i = 0; i < size; i += SPL_BUFSIZ) {
274 		amt = SPL_BUFSIZ;
275 		cp = buf;
276 		if (i + amt > size)
277 			amt = size - i;
278 		do {
279 			j = read(STDOUT_FILENO, cp, amt);
280 			if (j <= 0) {
281 				frecverr("%s: lost connection", pp->printer);
282 				/*NOTREACHED*/
283 			}
284 			amt -= j;
285 			cp += j;
286 		} while (amt > 0);
287 		amt = SPL_BUFSIZ;
288 		if (i + amt > size)
289 			amt = size - i;
290 		if (write(fd, buf, amt) != (ssize_t)amt) {
291 			err++;
292 			break;
293 		}
294 	}
295 	(void) close(fd);
296 	if (err) {
297 		frecverr("%s: write error on close(%s)", pp->printer, file);
298 		/*NOTREACHED*/
299 	}
300 	if (noresponse()) {		/* file sent had bad data in it */
301 		if (strchr(file, '/') == NULL)
302 			(void) unlink(file);
303 		return (0);
304 	}
305 	ack();
306 	return (1);
307 }
308 
309 static int
310 noresponse(void)
311 {
312 	char resp;
313 
314 	if (read(STDOUT_FILENO, &resp, (size_t)1) != 1) {
315 		frecverr("lost connection in noresponse()");
316 		/*NOTREACHED*/
317 	}
318 	if (resp == '\0')
319 		return(0);
320 	return(1);
321 }
322 
323 /*
324  * Check to see if there is enough space on the disk for size bytes.
325  * 1 == OK, 0 == Not OK.
326  */
327 static int
328 chksize(int size)
329 {
330 	int64_t spacefree;
331 	struct statfs sfb;
332 
333 	if (statfs(".", &sfb) < 0) {
334 		syslog(LOG_ERR, "%s: %m", "statfs(\".\")");
335 		return (1);
336 	}
337 	spacefree = sfb.f_bavail * (sfb.f_bsize / 512);
338 	size = (size + 511) / 512;
339 	if (minfree + size > spacefree)
340 		return(0);
341 	return(1);
342 }
343 
344 static int
345 read_number(const char *fn)
346 {
347 	char lin[80];
348 	register FILE *fp;
349 
350 	if ((fp = fopen(fn, "r")) == NULL)
351 		return (0);
352 	if (fgets(lin, sizeof(lin), fp) == NULL) {
353 		fclose(fp);
354 		return (0);
355 	}
356 	fclose(fp);
357 	return (atoi(lin));
358 }
359 
360 /*
361  * Remove all the files associated with the current job being transferred.
362  */
363 static void
364 rcleanup(int signo __unused)
365 {
366 	if (tfname[0] && strchr(tfname, '/') == NULL)
367 		(void) unlink(tfname);
368 	if (dfname[0] && strchr(dfname, '/') == NULL) {
369 		do {
370 			do
371 				(void) unlink(dfname);
372 			while (dfname[2]-- != 'A');
373 			dfname[2] = 'z';
374 		} while (dfname[0]-- != 'd');
375 	}
376 	dfname[0] = '\0';
377 }
378 
379 #include <stdarg.h>
380 
381 static void
382 frecverr(const char *msg, ...)
383 {
384 	va_list ap;
385 	va_start(ap, msg);
386 	syslog(LOG_ERR, "Error receiving job from %s:", from_host);
387 	vsyslog(LOG_ERR, msg, ap);
388 	va_end(ap);
389 	/*
390 	 * rcleanup is not called until AFTER logging the error message,
391 	 * because rcleanup will zap some variables which may have been
392 	 * supplied as parameters for that msg...
393 	 */
394 	rcleanup(0);
395 	/*
396 	 * Add a minimal delay before returning the final error code to
397 	 * the sending host.  This just in case that machine responds
398 	 * this error by INSTANTLY retrying (and instantly re-failing...).
399 	 * It would be stupid of the sending host to do that, but if there
400 	 * was a broken implementation which did it, the result might be
401 	 * obscure performance problems and a flood of syslog messages on
402 	 * the receiving host.
403 	 */
404 	sleep(2);		/* a paranoid throttling measure */
405 	putchar('\1');		/* return error code */
406 	exit(1);
407 }
408