pw/pw_log.c

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