1 /* $OpenBSD: logwtmp.c,v 1.11 2019/06/28 13:32:43 deraadt Exp $ */ 2 /* 3 * Copyright (c) 1988, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/types.h> 32 #include <sys/time.h> 33 #include <sys/stat.h> 34 35 #include <fcntl.h> 36 #include <string.h> 37 #include <unistd.h> 38 #include <utmp.h> 39 40 #include "util.h" 41 42 void 43 logwtmp(const char *line, const char *name, const char *host) 44 { 45 struct stat buf; 46 struct utmp ut; 47 int fd; 48 49 if ((fd = open(_PATH_WTMP, O_WRONLY|O_APPEND|O_CLOEXEC)) == -1) 50 return; 51 if (fstat(fd, &buf) == 0) { 52 (void) strncpy(ut.ut_line, line, sizeof(ut.ut_line)); 53 (void) strncpy(ut.ut_name, name, sizeof(ut.ut_name)); 54 (void) strncpy(ut.ut_host, host, sizeof(ut.ut_host)); 55 (void) time(&ut.ut_time); 56 if (write(fd, &ut, sizeof(struct utmp)) != 57 sizeof(struct utmp)) 58 (void) ftruncate(fd, buf.st_size); 59 } 60 (void) close(fd); 61 } 62