1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (C) 1996 5 * David L. Nugent. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY DAVID L. NUGENT AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL DAVID L. NUGENT OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #ifndef lint 30 static const char rcsid[] = 31 "$FreeBSD$"; 32 #endif /* not lint */ 33 34 #include <ctype.h> 35 #include <err.h> 36 #include <fcntl.h> 37 #include <string.h> 38 #include <stdarg.h> 39 40 #include "pw.h" 41 42 static FILE *logfile = NULL; 43 44 void 45 pw_log(struct userconf * cnf, int mode, int which, char const * fmt,...) 46 { 47 va_list argp; 48 time_t now; 49 const char *cp, *name; 50 struct tm *t; 51 int fd, i, rlen; 52 char nfmt[256], sname[32]; 53 54 if (cnf->logfile == NULL || cnf->logfile[0] == '\0') { 55 return; 56 } 57 58 if (logfile == NULL) { 59 /* With umask==0 we need to control file access modes on create */ 60 fd = open(cnf->logfile, O_WRONLY | O_CREAT | O_APPEND, 0600); 61 if (fd == -1) { 62 return; 63 } 64 logfile = fdopen(fd, "a"); 65 if (logfile == NULL) { 66 return; 67 } 68 } 69 70 if ((name = getenv("LOGNAME")) == NULL && 71 (name = getenv("USER")) == NULL) { 72 strcpy(sname, "unknown"); 73 } else { 74 /* 75 * Since "name" will be embedded in a printf-like format, 76 * we must sanitize it: 77 * 78 * Limit its length so other information in the message 79 * is not truncated 80 * 81 * Squeeze out embedded whitespace for the benefit of 82 * log file parsers 83 * 84 * Escape embedded % characters with another % 85 */ 86 for (i = 0, cp = name; 87 *cp != '\0' && i < (int)sizeof(sname) - 1; cp++) { 88 if (*cp == '%') { 89 if (i < (int)sizeof(sname) - 2) { 90 sname[i++] = '%'; 91 sname[i++] = '%'; 92 } else { 93 break; 94 } 95 } else if (!isspace(*cp)) { 96 sname[i++] = *cp; 97 } /* else do nothing */ 98 } 99 if (i == 0) { 100 strcpy(sname, "unknown"); 101 } else { 102 sname[i] = '\0'; 103 } 104 } 105 now = time(NULL); 106 t = localtime(&now); 107 /* ISO 8601 International Standard Date format */ 108 strftime(nfmt, sizeof nfmt, "%Y-%m-%d %T ", t); 109 rlen = sizeof(nfmt) - strlen(nfmt); 110 if (rlen <= 0 || snprintf(nfmt + strlen(nfmt), rlen, 111 "[%s:%s%s] %s\n", sname, Which[which], Modes[mode], 112 fmt) >= rlen) { 113 warnx("log format overflow, user name=%s", sname); 114 } else { 115 va_start(argp, fmt); 116 vfprintf(logfile, nfmt, argp); 117 va_end(argp); 118 fflush(logfile); 119 } 120 } 121