xref: /freebsd/usr.sbin/lpr/lpd/recvjob.c (revision 18849b5da0c5eaa88500b457be05b038813b51b1)
1 /*
2  * Copyright (c) 1983, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 4. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #ifndef lint
32 static const char copyright[] =
33 "@(#) Copyright (c) 1983, 1993\n\
34 	The Regents of the University of California.  All rights reserved.\n";
35 #endif /* not lint */
36 
37 #if 0
38 #ifndef lint
39 static char sccsid[] = "@(#)recvjob.c	8.2 (Berkeley) 4/27/95";
40 #endif /* not lint */
41 #endif
42 
43 #include "lp.cdefs.h"		/* A cross-platform version of <sys/cdefs.h> */
44 __FBSDID("$FreeBSD$");
45 
46 /*
47  * Receive printer jobs from the network, queue them and
48  * start the printer daemon.
49  */
50 #include <sys/param.h>
51 #include <sys/mount.h>
52 #include <sys/stat.h>
53 
54 #include <unistd.h>
55 #include <signal.h>
56 #include <fcntl.h>
57 #include <dirent.h>
58 #include <errno.h>
59 #include <syslog.h>
60 #include <stdio.h>
61 #include <stdlib.h>
62 #include <string.h>
63 #include "lp.h"
64 #include "lp.local.h"
65 #include "ctlinfo.h"
66 #include "extern.h"
67 #include "pathnames.h"
68 
69 #define ack()	(void) write(STDOUT_FILENO, sp, (size_t)1);
70 
71 /*
72  * The buffer size to use when reading/writing spool files.
73  */
74 #define	SPL_BUFSIZ	BUFSIZ
75 
76 static char	 dfname[NAME_MAX];	/* data files */
77 static int	 minfree;       /* keep at least minfree blocks available */
78 static const char	*sp = "";
79 static char	 tfname[NAME_MAX];	/* tmp copy of cf before linking */
80 
81 static int	 chksize(int _size);
82 static void	 frecverr(const char *_msg, ...) __printf0like(1, 2);
83 static int	 noresponse(void);
84 static void	 rcleanup(int _signo);
85 static int	 read_number(const char *_fn);
86 static int	 readfile(struct printer *_pp, char *_file, size_t _size);
87 static int	 readjob(struct printer *_pp);
88 
89 
90 void
91 recvjob(const char *printer)
92 {
93 	struct stat stb;
94 	int status;
95 	struct printer myprinter, *pp = &myprinter;
96 
97 	/*
98 	 * Perform lookup for printer name or abbreviation
99 	 */
100 	init_printer(pp);
101 	status = getprintcap(printer, pp);
102 	switch (status) {
103 	case PCAPERR_OSERR:
104 		frecverr("cannot open printer description file");
105 		break;
106 	case PCAPERR_NOTFOUND:
107 		frecverr("unknown printer %s", printer);
108 		break;
109 	case PCAPERR_TCLOOP:
110 		fatal(pp, "potential reference loop detected in printcap file");
111 	default:
112 		break;
113 	}
114 
115 	(void) close(STDERR_FILENO);			/* set up log file */
116 	if (open(pp->log_file, O_WRONLY|O_APPEND, 0664) < 0) {
117 		syslog(LOG_ERR, "%s: %m", pp->log_file);
118 		(void) open(_PATH_DEVNULL, O_WRONLY);
119 	}
120 
121 	if (chdir(pp->spool_dir) < 0)
122 		frecverr("%s: chdir(%s): %s", pp->printer, pp->spool_dir,
123 		    strerror(errno));
124 	if (stat(pp->lock_file, &stb) == 0) {
125 		if (stb.st_mode & 010) {
126 			/* queue is disabled */
127 			putchar('\1');		/* return error code */
128 			exit(1);
129 		}
130 	} else if (stat(pp->spool_dir, &stb) < 0)
131 		frecverr("%s: stat(%s): %s", pp->printer, pp->spool_dir,
132 		    strerror(errno));
133 	minfree = 2 * read_number("minfree");	/* scale KB to 512 blocks */
134 	signal(SIGTERM, rcleanup);
135 	signal(SIGPIPE, rcleanup);
136 
137 	if (readjob(pp))
138 		printjob(pp);
139 }
140 
141 /*
142  * Read printer jobs sent by lpd and copy them to the spooling directory.
143  * Return the number of jobs successfully transferred.
144  */
145 static int
146 readjob(struct printer *pp)
147 {
148 	register int size;
149 	int cfcnt, dfcnt;
150 	char *cp, *clastp, *errmsg;
151 	char givenid[32], givenhost[MAXHOSTNAMELEN];
152 
153 	ack();
154 	cfcnt = 0;
155 	dfcnt = 0;
156 	for (;;) {
157 		/*
158 		 * Read a command to tell us what to do
159 		 */
160 		cp = line;
161 		clastp = line + sizeof(line) - 1;
162 		do {
163 			size = read(STDOUT_FILENO, cp, (size_t)1);
164 			if (size != (ssize_t)1) {
165 				if (size < (ssize_t)0) {
166 					frecverr("%s: lost connection",
167 					    pp->printer);
168 					/*NOTREACHED*/
169 				}
170 				return (cfcnt);
171 			}
172 		} while ((*cp++ != '\n') && (cp <= clastp));
173 		if (cp > clastp) {
174 			frecverr("%s: readjob overflow", pp->printer);
175 			/*NOTREACHED*/
176 		}
177 		*--cp = '\0';
178 		cp = line;
179 		switch (*cp++) {
180 		case '\1':	/* cleanup because data sent was bad */
181 			rcleanup(0);
182 			continue;
183 
184 		case '\2':	/* read cf file */
185 			size = 0;
186 			dfcnt = 0;
187 			while (*cp >= '0' && *cp <= '9')
188 				size = size * 10 + (*cp++ - '0');
189 			if (*cp++ != ' ')
190 				break;
191 			/*
192 			 * host name has been authenticated, we use our
193 			 * view of the host name since we may be passed
194 			 * something different than what gethostbyaddr()
195 			 * returns
196 			 */
197 			strlcpy(cp + 6, from_host, sizeof(line)
198 			    + (size_t)(line - cp - 6));
199 			if (strchr(cp, '/')) {
200 				frecverr("readjob: %s: illegal path name", cp);
201 				/*NOTREACHED*/
202 			}
203 			strlcpy(tfname, cp, sizeof(tfname));
204 			tfname[sizeof (tfname) - 1] = '\0';
205 			tfname[0] = 't';
206 			if (!chksize(size)) {
207 				(void) write(STDOUT_FILENO, "\2", (size_t)1);
208 				continue;
209 			}
210 			if (!readfile(pp, tfname, (size_t)size)) {
211 				rcleanup(0);
212 				continue;
213 			}
214 			errmsg = ctl_renametf(pp->printer, tfname);
215 			tfname[0] = '\0';
216 			if (errmsg != NULL) {
217 				frecverr("%s: %s", pp->printer, errmsg);
218 				/*NOTREACHED*/
219 			}
220 			cfcnt++;
221 			continue;
222 
223 		case '\3':	/* read df file */
224 			*givenid = '\0';
225 			*givenhost = '\0';
226 			size = 0;
227 			while (*cp >= '0' && *cp <= '9')
228 				size = size * 10 + (*cp++ - '0');
229 			if (*cp++ != ' ')
230 				break;
231 			if (strchr(cp, '/')) {
232 				frecverr("readjob: %s: illegal path name", cp);
233 				/*NOTREACHED*/
234 			}
235 			if (!chksize(size)) {
236 				(void) write(STDOUT_FILENO, "\2", (size_t)1);
237 				continue;
238 			}
239 			strlcpy(dfname, cp, sizeof(dfname));
240 			dfcnt++;
241 			trstat_init(pp, dfname, dfcnt);
242 			(void) readfile(pp, dfname, (size_t)size);
243 			trstat_write(pp, TR_RECVING, (size_t)size, givenid,
244 			    from_host, givenhost);
245 			continue;
246 		}
247 		frecverr("protocol screwup: %s", line);
248 		/*NOTREACHED*/
249 	}
250 }
251 
252 /*
253  * Read files send by lpd and copy them to the spooling directory.
254  */
255 static int
256 readfile(struct printer *pp, char *file, size_t size)
257 {
258 	register char *cp;
259 	char buf[SPL_BUFSIZ];
260 	size_t amt, i;
261 	int err, fd, j;
262 
263 	fd = open(file, O_CREAT|O_EXCL|O_WRONLY, FILMOD);
264 	if (fd < 0) {
265 		frecverr("%s: readfile: error on open(%s): %s",
266 			 pp->printer, file, strerror(errno));
267 		/*NOTREACHED*/
268 	}
269 	ack();
270 	err = 0;
271 	for (i = 0; i < size; i += SPL_BUFSIZ) {
272 		amt = SPL_BUFSIZ;
273 		cp = buf;
274 		if (i + amt > size)
275 			amt = size - i;
276 		do {
277 			j = read(STDOUT_FILENO, cp, amt);
278 			if (j <= 0) {
279 				frecverr("%s: lost connection", pp->printer);
280 				/*NOTREACHED*/
281 			}
282 			amt -= j;
283 			cp += j;
284 		} while (amt > 0);
285 		amt = SPL_BUFSIZ;
286 		if (i + amt > size)
287 			amt = size - i;
288 		if (write(fd, buf, amt) != (ssize_t)amt) {
289 			err++;
290 			break;
291 		}
292 	}
293 	(void) close(fd);
294 	if (err) {
295 		frecverr("%s: write error on close(%s)", pp->printer, file);
296 		/*NOTREACHED*/
297 	}
298 	if (noresponse()) {		/* file sent had bad data in it */
299 		if (strchr(file, '/') == NULL)
300 			(void) unlink(file);
301 		return (0);
302 	}
303 	ack();
304 	return (1);
305 }
306 
307 static int
308 noresponse(void)
309 {
310 	char resp;
311 
312 	if (read(STDOUT_FILENO, &resp, (size_t)1) != 1) {
313 		frecverr("lost connection in noresponse()");
314 		/*NOTREACHED*/
315 	}
316 	if (resp == '\0')
317 		return(0);
318 	return(1);
319 }
320 
321 /*
322  * Check to see if there is enough space on the disk for size bytes.
323  * 1 == OK, 0 == Not OK.
324  */
325 static int
326 chksize(int size)
327 {
328 	int64_t spacefree;
329 	struct statfs sfb;
330 
331 	if (statfs(".", &sfb) < 0) {
332 		syslog(LOG_ERR, "%s: %m", "statfs(\".\")");
333 		return (1);
334 	}
335 	spacefree = sfb.f_bavail * (sfb.f_bsize / 512);
336 	size = (size + 511) / 512;
337 	if (minfree + size > spacefree)
338 		return(0);
339 	return(1);
340 }
341 
342 static int
343 read_number(const char *fn)
344 {
345 	char lin[80];
346 	register FILE *fp;
347 
348 	if ((fp = fopen(fn, "r")) == NULL)
349 		return (0);
350 	if (fgets(lin, sizeof(lin), fp) == NULL) {
351 		fclose(fp);
352 		return (0);
353 	}
354 	fclose(fp);
355 	return (atoi(lin));
356 }
357 
358 /*
359  * Remove all the files associated with the current job being transferred.
360  */
361 static void
362 rcleanup(int signo __unused)
363 {
364 	if (tfname[0] && strchr(tfname, '/') == NULL)
365 		(void) unlink(tfname);
366 	if (dfname[0] && strchr(dfname, '/') == NULL) {
367 		do {
368 			do
369 				(void) unlink(dfname);
370 			while (dfname[2]-- != 'A');
371 			dfname[2] = 'z';
372 		} while (dfname[0]-- != 'd');
373 	}
374 	dfname[0] = '\0';
375 }
376 
377 #include <stdarg.h>
378 
379 static void
380 frecverr(const char *msg, ...)
381 {
382 	va_list ap;
383 	va_start(ap, msg);
384 	syslog(LOG_ERR, "Error receiving job from %s:", from_host);
385 	vsyslog(LOG_ERR, msg, ap);
386 	va_end(ap);
387 	/*
388 	 * rcleanup is not called until AFTER logging the error message,
389 	 * because rcleanup will zap some variables which may have been
390 	 * supplied as parameters for that msg...
391 	 */
392 	rcleanup(0);
393 	/*
394 	 * Add a minimal delay before returning the final error code to
395 	 * the sending host.  This just in case that machine responds
396 	 * this error by INSTANTLY retrying (and instantly re-failing...).
397 	 * It would be stupid of the sending host to do that, but if there
398 	 * was a broken implementation which did it, the result might be
399 	 * obscure performance problems and a flood of syslog messages on
400 	 * the receiving host.
401 	 */
402 	sleep(2);		/* a paranoid throttling measure */
403 	putchar('\1');		/* return error code */
404 	exit(1);
405 }
406