1 /* $NetBSD: utmp.c,v 1.8 2009/01/11 02:46:27 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 #include "namespace.h" 34 #include <sys/types.h> 35 #include <sys/param.h> 36 #include <stdio.h> 37 #include <string.h> 38 #include <time.h> 39 #include <utmp.h> 40 #include <sys/stat.h> 41 42 static struct utmp utmp; 43 static FILE *ut; 44 static char utfile[MAXPATHLEN] = _PATH_UTMP; 45 46 void 47 setutent(void) 48 { 49 if (ut == NULL) 50 return; 51 (void)fseeko(ut, (off_t)0, SEEK_SET); 52 } 53 54 struct utmp * 55 getutent(void) 56 { 57 if (ut == NULL) { 58 struct stat st; 59 off_t numentries; 60 if ((ut = fopen(utfile, "r")) == NULL) 61 return NULL; 62 if (fstat(fileno(ut), &st) == -1) 63 goto out; 64 /* 65 * If we have a an old version utmp file bail. 66 */ 67 numentries = st.st_size / sizeof(utmp); 68 if ((off_t)(numentries * sizeof(utmp)) != st.st_size) 69 goto out; 70 } 71 if (fread(&utmp, sizeof(utmp), 1, ut) == 1) 72 return &utmp; 73 out: 74 (void)fclose(ut); 75 return NULL; 76 } 77 78 void 79 endutent(void) 80 { 81 if (ut != NULL) { 82 (void)fclose(ut); 83 ut = NULL; 84 } 85 } 86 87 int 88 utmpname(const char *fname) 89 { 90 size_t len = strlen(fname); 91 92 if (len >= sizeof(utfile)) 93 return 0; 94 95 /* must not end in x! */ 96 if (fname[len - 1] == 'x') 97 return 0; 98 99 (void)strlcpy(utfile, fname, sizeof(utfile)); 100 endutent(); 101 return 1; 102 } 103