1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 #include <ctype.h> 30 #include <err.h> 31 #include <fcntl.h> 32 #include <string.h> 33 #include <stdarg.h> 34 35 #include "pw.h" 36 37 static FILE *logfile = NULL; 38 39 void 40 pw_log(struct userconf * cnf, int mode, int which, char const * fmt,...) 41 { 42 va_list argp; 43 time_t now; 44 const char *cp, *name; 45 struct tm *t; 46 int fd, i, rlen; 47 char nfmt[256], sname[32]; 48 49 if (cnf->logfile == NULL || cnf->logfile[0] == '\0') { 50 return; 51 } 52 53 if (logfile == NULL) { 54 /* With umask==0 we need to control file access modes on create */ 55 fd = open(cnf->logfile, O_WRONLY | O_CREAT | O_APPEND, 0600); 56 if (fd == -1) { 57 return; 58 } 59 logfile = fdopen(fd, "a"); 60 if (logfile == NULL) { 61 return; 62 } 63 } 64 65 if ((name = getenv("LOGNAME")) == NULL && 66 (name = getenv("USER")) == NULL) { 67 strcpy(sname, "unknown"); 68 } else { 69 /* 70 * Since "name" will be embedded in a printf-like format, 71 * we must sanitize it: 72 * 73 * Limit its length so other information in the message 74 * is not truncated 75 * 76 * Squeeze out embedded whitespace for the benefit of 77 * log file parsers 78 * 79 * Escape embedded % characters with another % 80 */ 81 for (i = 0, cp = name; 82 *cp != '\0' && i < (int)sizeof(sname) - 1; cp++) { 83 if (*cp == '%') { 84 if (i < (int)sizeof(sname) - 2) { 85 sname[i++] = '%'; 86 sname[i++] = '%'; 87 } else { 88 break; 89 } 90 } else if (!isspace(*cp)) { 91 sname[i++] = *cp; 92 } /* else do nothing */ 93 } 94 if (i == 0) { 95 strcpy(sname, "unknown"); 96 } else { 97 sname[i] = '\0'; 98 } 99 } 100 now = time(NULL); 101 t = localtime(&now); 102 /* ISO 8601 International Standard Date format */ 103 strftime(nfmt, sizeof nfmt, "%Y-%m-%d %T ", t); 104 rlen = sizeof(nfmt) - strlen(nfmt); 105 if (rlen <= 0 || snprintf(nfmt + strlen(nfmt), rlen, 106 "[%s:%s%s] %s\n", sname, Which[which], Modes[mode], 107 fmt) >= rlen) { 108 warnx("log format overflow, user name=%s", sname); 109 } else { 110 va_start(argp, fmt); 111 vfprintf(logfile, nfmt, argp); 112 va_end(argp); 113 fflush(logfile); 114 } 115 } 116