1 /* $NetBSD: utmp.c,v 1.10 2011/10/15 23:00:02 christos Exp $ */
2
3 /*-
4 * Copyright (c) 2002 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christos Zoulas.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31 #include <sys/cdefs.h>
32
33 #if defined(LIBC_SCCS) && !defined(lint)
34 __RCSID("$NetBSD: utmp.c,v 1.10 2011/10/15 23:00:02 christos Exp $");
35 #endif /* LIBC_SCCS and not lint */
36
37 #include "namespace.h"
38 #include <sys/types.h>
39 #include <sys/param.h>
40 #include <stdio.h>
41 #include <string.h>
42 #include <time.h>
43 #include <utmp.h>
44 #include <sys/stat.h>
45
46 static struct utmp utmp;
47 static FILE *ut;
48 static char utfile[MAXPATHLEN] = _PATH_UTMP;
49
50 void
setutent(void)51 setutent(void)
52 {
53 if (ut == NULL)
54 return;
55 (void)fseeko(ut, (off_t)0, SEEK_SET);
56 }
57
58 struct utmp *
getutent(void)59 getutent(void)
60 {
61 if (ut == NULL) {
62 struct stat st;
63 off_t numentries;
64 if ((ut = fopen(utfile, "re")) == NULL)
65 return NULL;
66 if (fstat(fileno(ut), &st) == -1)
67 goto out;
68 /*
69 * If we have a an old version utmp file bail.
70 */
71 numentries = st.st_size / sizeof(utmp);
72 if ((off_t)(numentries * sizeof(utmp)) != st.st_size)
73 goto out;
74 }
75 if (fread(&utmp, sizeof(utmp), 1, ut) == 1)
76 return &utmp;
77 out:
78 (void)fclose(ut);
79 return NULL;
80 }
81
82 void
endutent(void)83 endutent(void)
84 {
85 if (ut != NULL) {
86 (void)fclose(ut);
87 ut = NULL;
88 }
89 }
90
91 int
utmpname(const char * fname)92 utmpname(const char *fname)
93 {
94 size_t len = strlen(fname);
95
96 if (len >= sizeof(utfile))
97 return 0;
98
99 /* must not end in x! */
100 if (fname[len - 1] == 'x')
101 return 0;
102
103 (void)strlcpy(utfile, fname, sizeof(utfile));
104 endutent();
105 return 1;
106 }
107