misc/syslog.c

   1 /*
   2  * Copyright (c) 1983, 1988, 1993
   3  *      The Regents of the University of California.  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  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #if defined(LIBC_SCCS) && !defined(lint)
  35 static char sccsid[] = "@(#)syslog.c    8.4 (Berkeley) 3/18/94";
  36 #endif /* LIBC_SCCS and not lint */
  37
  38 #include <sys/types.h>
  39 #include <sys/socket.h>
  40 #include <sys/syslog.h>
  41 #include <sys/uio.h>
  42 #include <netdb.h>
  43
  44 #include <errno.h>
  45 #include <fcntl.h>
  46 #include <paths.h>
  47 #include <stdio.h>
  48 #include <string.h>
  49 #include <time.h>
  50 #include <unistd.h>
  51
  52 #if __STDC__
  53 #include <stdarg.h>
  54 #else
  55 #include <varargs.h>
  56 #endif
  57
  58 static int      LogFile = -1;           /* fd for log */
  59 static int      connected;              /* have done connect */
  60 static int      LogStat = 0;            /* status bits, set by openlog() */
  61 static const char *LogTag = NULL;       /* string to tag the entry with */
  62 static int      LogFacility = LOG_USER; /* default facility code */
  63 static int      LogMask = 0xff;         /* mask of priorities to be logged */
  64 extern char     *__progname;            /* Program name, from crt0. */
  65
  66 /*
  67  * syslog, vsyslog --
  68  *      print message on log file; output is intended for syslogd(8).
  69  */
  70 void
  71 #if __STDC__
  72 syslog(int pri, const char *fmt, ...)
  73 #else
  74 syslog(pri, fmt, va_alist)
  75         int pri;
  76         char *fmt;
  77         va_dcl
  78 #endif
  79 {
  80         va_list ap;
  81
  82 #if __STDC__
  83         va_start(ap, fmt);
  84 #else
  85         va_start(ap);
  86 #endif
  87         vsyslog(pri, fmt, ap);
  88         va_end(ap);
  89 }
  90
  91 void
  92 vsyslog(pri, fmt, ap)
  93         int pri;
  94         register const char *fmt;
  95         va_list ap;
  96 {
  97         register int cnt;
  98         register char ch, *p, *t;
  99         time_t now;
 100         int fd, saved_errno;
 101         char *stdp, tbuf[2048], fmt_cpy[1024];
 102
 103 #define INTERNALLOG     LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID
 104         /* Check for invalid bits. */
 105         if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) {
 106                 syslog(INTERNALLOG,
 107                     "syslog: unknown facility/priority: %x", pri);
 108                 pri &= LOG_PRIMASK|LOG_FACMASK;
 109         }
 110
 111         /* Check priority against setlogmask values. */
 112         if (!LOG_MASK(LOG_PRI(pri)) & LogMask)
 113                 return;
 114
 115         saved_errno = errno;
 116
 117         /* Set default facility if none specified. */
 118         if ((pri & LOG_FACMASK) == 0)
 119                 pri |= LogFacility;
 120
 121         /* Build the message. */
 122         (void)time(&now);
 123         p = tbuf + sprintf(tbuf, "<%d>", pri);
 124         p += strftime(p, sizeof (tbuf) - (p - tbuf), "%h %e %T ",
 125             localtime(&now));
 126         if (LogStat & LOG_PERROR)
 127                 stdp = p;
 128         if (LogTag == NULL)
 129                 LogTag = __progname;
 130         if (LogTag != NULL)
 131                 p += sprintf(p, "%s", LogTag);
 132         if (LogStat & LOG_PID)
 133                 p += sprintf(p, "[%d]", getpid());
 134         if (LogTag != NULL) {
 135                 *p++ = ':';
 136                 *p++ = ' ';
 137         }
 138
 139         /* Substitute error message for %m. */
 140         for (t = fmt_cpy; ch = *fmt; ++fmt)
 141                 if (ch == '%' && fmt[1] == 'm') {
 142                         ++fmt;
 143                         t += sprintf(t, "%s", strerror(saved_errno));
 144                 } else
 145                         *t++ = ch;
 146         *t = '\0';
 147
 148         p += vsprintf(p, fmt_cpy, ap);
 149         cnt = p - tbuf;
 150
 151         /* Output to stderr if requested. */
 152         if (LogStat & LOG_PERROR) {
 153                 struct iovec iov[2];
 154                 register struct iovec *v = iov;
 155
 156                 v->iov_base = stdp;
 157                 v->iov_len = cnt - (stdp - tbuf);
 158                 ++v;
 159                 v->iov_base = "\n";
 160                 v->iov_len = 1;
 161                 (void)writev(STDERR_FILENO, iov, 2);
 162         }
 163
 164         /* Get connected, output the message to the local logger. */
 165         if (!connected)
 166                 openlog(LogTag, LogStat | LOG_NDELAY, 0);
 167         if (send(LogFile, tbuf, cnt, 0) >= 0)
 168                 return;
 169
 170         /*
 171          * Output the message to the console; don't worry about blocking,
 172          * if console blocks everything will.  Make sure the error reported
 173          * is the one from the syslogd failure.
 174          */
 175         if (LogStat & LOG_CONS &&
 176             (fd = open(_PATH_CONSOLE, O_WRONLY, 0)) >= 0) {
 177                 (void)strcat(tbuf, "\r\n");
 178                 cnt += 2;
 179                 p = index(tbuf, '>') + 1;
 180                 (void)write(fd, p, cnt - (p - tbuf));
 181                 (void)close(fd);
 182         }
 183 }
 184
 185 static struct sockaddr SyslogAddr;      /* AF_UNIX address of local logger */
 186
 187 void
 188 openlog(ident, logstat, logfac)
 189         const char *ident;
 190         int logstat, logfac;
 191 {
 192         if (ident != NULL)
 193                 LogTag = ident;
 194         LogStat = logstat;
 195         if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
 196                 LogFacility = logfac;
 197
 198         if (LogFile == -1) {
 199                 SyslogAddr.sa_family = AF_UNIX;
 200                 (void)strncpy(SyslogAddr.sa_data, _PATH_LOG,
 201                     sizeof(SyslogAddr.sa_data));
 202                 if (LogStat & LOG_NDELAY) {
 203                         if ((LogFile = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1)
 204                                 return;
 205                         (void)fcntl(LogFile, F_SETFD, 1);
 206                 }
 207         }
 208         if (LogFile != -1 && !connected)
 209                 if (connect(LogFile, &SyslogAddr, sizeof(SyslogAddr)) == -1) {
 210                         (void)close(LogFile);
 211                         LogFile = -1;
 212                 } else
 213                         connected = 1;
 214 }
 215
 216 void
 217 closelog()
 218 {
 219         (void)close(LogFile);
 220         LogFile = -1;
 221         connected = 0;
 222 }
 223
 224 /* setlogmask -- set the log mask level */
 225 int
 226 setlogmask(pmask)
 227         int pmask;
 228 {
 229         int omask;
 230
 231         omask = LogMask;
 232         if (pmask != 0)
 233                 LogMask = pmask;
 234         return (omask);
 235 }