recvjob.c revision 331722 
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
32static 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
39static 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: stable/11/usr.sbin/lpr/lpd/recvjob.c 331722 2018-03-29 02:50:57Z eadler $");
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
76static char	 dfname[NAME_MAX];	/* data files */
77static int	 minfree;       /* keep at least minfree blocks available */
78static const char	*sp = "";
79static char	 tfname[NAME_MAX];	/* tmp copy of cf before linking */
80
81static int	 chksize(int _size);
82static void	 frecverr(const char *_msg, ...) __printf0like(1, 2);
83static int	 noresponse(void);
84static void	 rcleanup(int _signo);
85static int	 read_number(const char *_fn);
86static int	 readfile(struct printer *_pp, char *_file, size_t _size);
87static int	 readjob(struct printer *_pp);
88
89
90void
91recvjob(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 */
145static int
146readjob(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 */
255static int
256readfile(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
307static int
308noresponse(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 */
325static int
326chksize(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
342static int
343read_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 */
361static void
362rcleanup(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
379static void
380frecverr(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