xref: /dflybsd-src/lib/libc/gen/utmp.c (revision 59a92d1877d6bb6c4fc9d7be5e51943661e50c2f)
1*59a92d18SAlex Hornung /*	$NetBSD: utmp.c,v 1.8 2009/01/11 02:46:27 christos Exp $	 */
2*59a92d18SAlex Hornung 
3*59a92d18SAlex Hornung /*-
4*59a92d18SAlex Hornung  * Copyright (c) 2002 The NetBSD Foundation, Inc.
5*59a92d18SAlex Hornung  * All rights reserved.
6*59a92d18SAlex Hornung  *
7*59a92d18SAlex Hornung  * This code is derived from software contributed to The NetBSD Foundation
8*59a92d18SAlex Hornung  * by Christos Zoulas.
9*59a92d18SAlex Hornung  *
10*59a92d18SAlex Hornung  * Redistribution and use in source and binary forms, with or without
11*59a92d18SAlex Hornung  * modification, are permitted provided that the following conditions
12*59a92d18SAlex Hornung  * are met:
13*59a92d18SAlex Hornung  * 1. Redistributions of source code must retain the above copyright
14*59a92d18SAlex Hornung  *    notice, this list of conditions and the following disclaimer.
15*59a92d18SAlex Hornung  * 2. Redistributions in binary form must reproduce the above copyright
16*59a92d18SAlex Hornung  *    notice, this list of conditions and the following disclaimer in the
17*59a92d18SAlex Hornung  *    documentation and/or other materials provided with the distribution.
18*59a92d18SAlex Hornung  *
19*59a92d18SAlex Hornung  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20*59a92d18SAlex Hornung  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21*59a92d18SAlex Hornung  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22*59a92d18SAlex Hornung  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23*59a92d18SAlex Hornung  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24*59a92d18SAlex Hornung  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25*59a92d18SAlex Hornung  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26*59a92d18SAlex Hornung  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27*59a92d18SAlex Hornung  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28*59a92d18SAlex Hornung  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29*59a92d18SAlex Hornung  * POSSIBILITY OF SUCH DAMAGE.
30*59a92d18SAlex Hornung  */
31*59a92d18SAlex Hornung #include <sys/cdefs.h>
32*59a92d18SAlex Hornung 
33*59a92d18SAlex Hornung #include "namespace.h"
34*59a92d18SAlex Hornung #include <sys/types.h>
35*59a92d18SAlex Hornung #include <sys/param.h>
36*59a92d18SAlex Hornung #include <stdio.h>
37*59a92d18SAlex Hornung #include <string.h>
38*59a92d18SAlex Hornung #include <time.h>
39*59a92d18SAlex Hornung #include <utmp.h>
40*59a92d18SAlex Hornung #include <sys/stat.h>
41*59a92d18SAlex Hornung 
42*59a92d18SAlex Hornung static struct utmp utmp;
43*59a92d18SAlex Hornung static FILE *ut;
44*59a92d18SAlex Hornung static char utfile[MAXPATHLEN] = _PATH_UTMP;
45*59a92d18SAlex Hornung 
46*59a92d18SAlex Hornung void
47*59a92d18SAlex Hornung setutent(void)
48*59a92d18SAlex Hornung {
49*59a92d18SAlex Hornung 	if (ut == NULL)
50*59a92d18SAlex Hornung 		return;
51*59a92d18SAlex Hornung 	(void)fseeko(ut, (off_t)0, SEEK_SET);
52*59a92d18SAlex Hornung }
53*59a92d18SAlex Hornung 
54*59a92d18SAlex Hornung struct utmp *
55*59a92d18SAlex Hornung getutent(void)
56*59a92d18SAlex Hornung {
57*59a92d18SAlex Hornung 	if (ut == NULL) {
58*59a92d18SAlex Hornung 		struct stat st;
59*59a92d18SAlex Hornung 		off_t numentries;
60*59a92d18SAlex Hornung 		if ((ut = fopen(utfile, "r")) == NULL)
61*59a92d18SAlex Hornung 			return NULL;
62*59a92d18SAlex Hornung 		if (fstat(fileno(ut), &st) == -1)
63*59a92d18SAlex Hornung 			goto out;
64*59a92d18SAlex Hornung 		/*
65*59a92d18SAlex Hornung 		 * If we have a an old version utmp file bail.
66*59a92d18SAlex Hornung 		 */
67*59a92d18SAlex Hornung 		numentries = st.st_size / sizeof(utmp);
68*59a92d18SAlex Hornung 		if ((off_t)(numentries * sizeof(utmp)) != st.st_size)
69*59a92d18SAlex Hornung 			goto out;
70*59a92d18SAlex Hornung 	}
71*59a92d18SAlex Hornung 	if (fread(&utmp, sizeof(utmp), 1, ut) == 1)
72*59a92d18SAlex Hornung 		return &utmp;
73*59a92d18SAlex Hornung out:
74*59a92d18SAlex Hornung 	(void)fclose(ut);
75*59a92d18SAlex Hornung 	return NULL;
76*59a92d18SAlex Hornung }
77*59a92d18SAlex Hornung 
78*59a92d18SAlex Hornung void
79*59a92d18SAlex Hornung endutent(void)
80*59a92d18SAlex Hornung {
81*59a92d18SAlex Hornung 	if (ut != NULL) {
82*59a92d18SAlex Hornung 		(void)fclose(ut);
83*59a92d18SAlex Hornung 		ut = NULL;
84*59a92d18SAlex Hornung 	}
85*59a92d18SAlex Hornung }
86*59a92d18SAlex Hornung 
87*59a92d18SAlex Hornung int
88*59a92d18SAlex Hornung utmpname(const char *fname)
89*59a92d18SAlex Hornung {
90*59a92d18SAlex Hornung 	size_t len = strlen(fname);
91*59a92d18SAlex Hornung 
92*59a92d18SAlex Hornung 	if (len >= sizeof(utfile))
93*59a92d18SAlex Hornung 		return 0;
94*59a92d18SAlex Hornung 
95*59a92d18SAlex Hornung 	/* must not end in x! */
96*59a92d18SAlex Hornung 	if (fname[len - 1] == 'x')
97*59a92d18SAlex Hornung 		return 0;
98*59a92d18SAlex Hornung 
99*59a92d18SAlex Hornung 	(void)strlcpy(utfile, fname, sizeof(utfile));
100*59a92d18SAlex Hornung 	endutent();
101*59a92d18SAlex Hornung 	return 1;
102*59a92d18SAlex Hornung }
103