startdaemon.c revision 31492 
1/*
2 * Copyright (c) 1983, 1993, 1994
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 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35#if 0
36static char sccsid[] = "@(#)startdaemon.c	8.2 (Berkeley) 4/17/94";
37#endif
38static const char rcsid[] =
39	"$Id: startdaemon.c,v 1.6 1997/09/24 06:47:32 charnier Exp $";
40#endif /* not lint */
41
42
43#include <sys/param.h>
44#include <sys/socket.h>
45#include <sys/uio.h>
46#include <sys/un.h>
47
48#include <dirent.h>
49#include <err.h>
50#include <stdio.h>
51#include <string.h>
52#include <unistd.h>
53#include "lp.h"
54#include "pathnames.h"
55
56extern uid_t	uid, euid;
57
58/*
59 * Tell the printer daemon that there are new files in the spool directory.
60 */
61
62int
63startdaemon(pp)
64	const struct printer *pp;
65{
66	struct sockaddr_un un;
67	register int s, n;
68	char c;
69
70	s = socket(PF_LOCAL, SOCK_STREAM, 0);
71	if (s < 0) {
72		warn("socket");
73		return(0);
74	}
75	memset(&un, 0, sizeof(un));
76	un.sun_family = AF_LOCAL;
77	strcpy(un.sun_path, _PATH_SOCKETNAME);
78#ifndef SUN_LEN
79#define SUN_LEN(unp) (strlen((unp)->sun_path) + 2)
80#endif
81	seteuid(euid);
82	if (connect(s, (struct sockaddr *)&un, SUN_LEN(&un)) < 0) {
83		seteuid(uid);
84		warn("connect");
85		(void) close(s);
86		return(0);
87	}
88	seteuid(uid);
89
90	/*
91	 * Avoid overruns without putting artificial limitations on
92	 * the length.
93	 */
94	if (writel(s, "\1", pp->printer, "\n", (char *)0) <= 0) {
95		warn("write");
96		(void) close(s);
97		return(0);
98	}
99	if (read(s, &c, 1) == 1) {
100		if (c == '\0') {		/* everything is OK */
101			(void) close(s);
102			return(1);
103		}
104		putchar(c);
105	}
106	while ((n = read(s, &c, 1)) > 0)
107		putchar(c);
108	(void) close(s);
109	return(0);
110}
111