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 #include <stdlib.h>
  52
  53 #if __STDC__
  54 #include <stdarg.h>
  55 #else
  56 #include <varargs.h>
  57 #endif
  58
  59 static int      LogFile = -1;           /* fd for log */
  60 static int      connected;              /* have done connect */
  61 static int      LogStat = 0;            /* status bits, set by openlog() */
  62 static const char *LogTag = NULL;       /* string to tag the entry with */
  63 static int      LogFacility = LOG_USER; /* default facility code */
  64 static int      LogMask = 0xff;         /* mask of priorities to be logged */
  65 extern char     *__progname;            /* Program name, from crt0. */
  66
  67 /*
  68  * syslog, vsyslog --
  69  *      print message on log file; output is intended for syslogd(8).
  70  */
  71 void
  72 #if __STDC__
  73 syslog(int pri, const char *fmt, ...)
  74 #else
  75 syslog(pri, fmt, va_alist)
  76         int pri;
  77         char *fmt;
  78         va_dcl
  79 #endif
  80 {
  81         va_list ap;
  82
  83 #if __STDC__
  84         va_start(ap, fmt);
  85 #else
  86         va_start(ap);
  87 #endif
  88         vsyslog(pri, fmt, ap);
  89         va_end(ap);
  90 }
  91
  92 void
  93 vsyslog(pri, fmt, ap)
  94         int pri;
  95         register const char *fmt;
  96         va_list ap;
  97 {
  98         time_t now;
  99         int fd;
 100         FILE *f;
 101         char *buf = 0;
 102         size_t bufsize = 0;
 103         size_t prioff, msgoff;
 104
 105 #define INTERNALLOG     LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID
 106         /* Check for invalid bits. */
 107         if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) {
 108                 syslog(INTERNALLOG,
 109                     "syslog: unknown facility/priority: %x", pri);
 110                 pri &= LOG_PRIMASK|LOG_FACMASK;
 111         }
 112
 113         /* Check priority against setlogmask values. */
 114         if (!LOG_MASK(LOG_PRI(pri)) & LogMask)
 115                 return;
 116
 117         /* Set default facility if none specified. */
 118         if ((pri & LOG_FACMASK) == 0)
 119                 pri |= LogFacility;
 120
 121         /* Build the message in a memory-buffer stream.  */
 122         f = open_memstream (&buf, &bufsize);
 123         prioff = fprintf (f, "<%d>", pri);
 124         (void) time (&now);
 125         f->__bufp += strftime (f->__bufp, f->__put_limit - f->__bufp,
 126                                "%h %e %T ", localtime (&now));
 127         msgoff = ftell (f);
 128         if (LogTag == NULL)
 129           LogTag = __progname;
 130         if (LogTag != NULL)
 131           fputs (LogTag, f);
 132         if (LogStat & LOG_PID)
 133           fprintf (f, "[%d]", getpid ());
 134         if (LogTag != NULL)
 135           putc (':', f), putc (' ', f);
 136
 137         /* We have the header.  Print the user's format into the buffer.  */
 138         vfprintf (f, fmt, ap);
 139
 140         /* Close the memory stream; this will finalize the data
 141            into a malloc'd buffer in BUF.  */
 142         fclose (f);
 143
 144         /* Output to stderr if requested. */
 145         if (LogStat & LOG_PERROR) {
 146                 struct iovec iov[2];
 147                 register struct iovec *v = iov;
 148
 149                 v->iov_base = buf + msgoff;
 150                 v->iov_len = bufsize - msgoff;
 151                 ++v;
 152                 v->iov_base = (char *) "\n";
 153                 v->iov_len = 1;
 154                 (void)writev(STDERR_FILENO, iov, 2);
 155         }
 156
 157         /* Get connected, output the message to the local logger. */
 158         if (!connected)
 159                 openlog(LogTag, LogStat | LOG_NDELAY, 0);
 160         if (send(LogFile, buf, bufsize, 0) < 0)
 161           {
 162             /*
 163              * Output the message to the console; don't worry about blocking,
 164              * if console blocks everything will.  Make sure the error reported
 165              * is the one from the syslogd failure.
 166              */
 167             if (LogStat & LOG_CONS &&
 168                 (fd = open(_PATH_CONSOLE, O_WRONLY, 0)) >= 0)
 169               {
 170                 dprintf (fd, "%s\r\n", buf + msgoff);
 171                 (void)close(fd);
 172               }
 173           }
 174
 175         free (buf);
 176 }
 177
 178 static struct sockaddr SyslogAddr;      /* AF_UNIX address of local logger */
 179
 180 void
 181 openlog(ident, logstat, logfac)
 182         const char *ident;
 183         int logstat, logfac;
 184 {
 185         if (ident != NULL)
 186                 LogTag = ident;
 187         LogStat = logstat;
 188         if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
 189                 LogFacility = logfac;
 190
 191         if (LogFile == -1) {
 192                 SyslogAddr.sa_family = AF_UNIX;
 193                 (void)strncpy(SyslogAddr.sa_data, _PATH_LOG,
 194                     sizeof(SyslogAddr.sa_data));
 195                 if (LogStat & LOG_NDELAY) {
 196                         if ((LogFile = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1)
 197                                 return;
 198                         (void)fcntl(LogFile, F_SETFD, 1);
 199                 }
 200         }
 201         if (LogFile != -1 && !connected)
 202                 if (connect(LogFile, &SyslogAddr, sizeof(SyslogAddr)) == -1) {
 203                         (void)close(LogFile);
 204                         LogFile = -1;
 205                 } else
 206                         connected = 1;
 207 }
 208
 209 void
 210 closelog()
 211 {
 212         (void)close(LogFile);
 213         LogFile = -1;
 214         connected = 0;
 215 }
 216
 217 /* setlogmask -- set the log mask level */
 218 int
 219 setlogmask(pmask)
 220         int pmask;
 221 {
 222         int omask;
 223
 224         omask = LogMask;
 225         if (pmask != 0)
 226                 LogMask = pmask;
 227         return (omask);
 228 }