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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * @(#)startdaemon.c	8.2 (Berkeley) 4/17/94
30  * $FreeBSD: src/usr.sbin/lpr/common_source/startdaemon.c,v 1.8.2.2 2002/04/26 18:24:40 gad Exp $
31  * $DragonFly: src/usr.sbin/lpr/common_source/startdaemon.c,v 1.4 2004/12/18 22:48:03 swildner Exp $
32  */
33 
34 #include <sys/param.h>
35 #include <sys/socket.h>
36 #include <sys/uio.h>
37 #include <sys/un.h>
38 
39 #include <dirent.h>
40 #include <err.h>
41 #include <stdio.h>
42 #include <string.h>
43 #include <unistd.h>
44 #include "lp.h"
45 #include "pathnames.h"
46 
47 extern uid_t	uid, euid;
48 
49 /*
50  * Tell the printer daemon that there are new files in the spool directory.
51  */
52 
53 int
54 startdaemon(const struct printer *pp)
55 {
56 	struct sockaddr_un un;
57 	int s, n;
58 	int connectres;
59 	char c;
60 
61 	s = socket(PF_LOCAL, SOCK_STREAM, 0);
62 	if (s < 0) {
63 		warn("socket");
64 		return(0);
65 	}
66 	memset(&un, 0, sizeof(un));
67 	un.sun_family = AF_LOCAL;
68 	strcpy(un.sun_path, _PATH_SOCKETNAME);
69 #ifndef SUN_LEN
70 #define SUN_LEN(unp) (strlen((unp)->sun_path) + 2)
71 #endif
72 	seteuid(euid);
73 	connectres = connect(s, (struct sockaddr *)&un, SUN_LEN(&un));
74 	seteuid(uid);
75 	if (connectres < 0) {
76 		warn("Unable to connect to %s", _PATH_SOCKETNAME);
77 		warnx("Check to see if the master 'lpd' process is running.");
78 		close(s);
79 		return(0);
80 	}
81 
82 	/*
83 	 * Avoid overruns without putting artificial limitations on
84 	 * the length.
85 	 */
86 	if (writel(s, "\1", pp->printer, "\n", NULL) <= 0) {
87 		warn("write");
88 		close(s);
89 		return(0);
90 	}
91 	if (read(s, &c, 1) == 1) {
92 		if (c == '\0') {		/* everything is OK */
93 			close(s);
94 			return(1);
95 		}
96 		putchar(c);
97 	}
98 	while ((n = read(s, &c, 1)) > 0)
99 		putchar(c);
100 	close(s);
101 	return(0);
102 }
103