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      LogType = SOCK_DGRAM;   /* type of socket connection */
  60 static int      LogFile = -1;           /* fd for log */
  61 static int      connected;              /* have done connect */
  62 static int      LogStat = 0;            /* status bits, set by openlog() */
  63 static const char *LogTag = NULL;       /* string to tag the entry with */
  64 static int      LogFacility = LOG_USER; /* default facility code */
  65 static int      LogMask = 0xff;         /* mask of priorities to be logged */
  66 extern char     *__progname;            /* Program name, from crt0. */
  67
  68 /*
  69  * syslog, vsyslog --
  70  *      print message on log file; output is intended for syslogd(8).
  71  */
  72 void
  73 #if __STDC__
  74 syslog(int pri, const char *fmt, ...)
  75 #else
  76 syslog(pri, fmt, va_alist)
  77         int pri;
  78         char *fmt;
  79         va_dcl
  80 #endif
  81 {
  82         va_list ap;
  83
  84 #if __STDC__
  85         va_start(ap, fmt);
  86 #else
  87         va_start(ap);
  88 #endif
  89         vsyslog(pri, fmt, ap);
  90         va_end(ap);
  91 }
  92
  93 void
  94 vsyslog(pri, fmt, ap)
  95         int pri;
  96         register const char *fmt;
  97         va_list ap;
  98 {
  99         struct tm now_tm;
 100         time_t now;
 101         int fd;
 102         FILE *f;
 103         char *buf = 0;
 104         size_t bufsize = 0;
 105         size_t prioff, msgoff;
 106
 107 #define INTERNALLOG     LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID
 108         /* Check for invalid bits. */
 109         if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) {
 110                 syslog(INTERNALLOG,
 111                     "syslog: unknown facility/priority: %x", pri);
 112                 pri &= LOG_PRIMASK|LOG_FACMASK;
 113         }
 114
 115         /* Check priority against setlogmask values. */
 116         if (!LOG_MASK(LOG_PRI(pri)) & LogMask)
 117                 return;
 118
 119         /* Set default facility if none specified. */
 120         if ((pri & LOG_FACMASK) == 0)
 121                 pri |= LogFacility;
 122
 123         /* Build the message in a memory-buffer stream.  */
 124         f = open_memstream (&buf, &bufsize);
 125         prioff = fprintf (f, "<%d>", pri);
 126         (void) time (&now);
 127 #ifdef USE_IN_LIBIO
 128         f->_IO_write_ptr += strftime (f->_IO_write_ptr,
 129                                       f->_IO_write_end - f->_IO_write_ptr,
 130                                       "%h %e %T ",
 131                                       __localtime_r (&now, &now_tm));
 132 #else
 133         f->__bufp += strftime (f->__bufp, f->__put_limit - f->__bufp,
 134                                "%h %e %T ", __localtime_r (&now, &now_tm));
 135 #endif
 136         msgoff = ftell (f);
 137         if (LogTag == NULL)
 138           LogTag = __progname;
 139         if (LogTag != NULL)
 140           fputs (LogTag, f);
 141         if (LogStat & LOG_PID)
 142           fprintf (f, "[%d]", getpid ());
 143         if (LogTag != NULL)
 144           putc (':', f), putc (' ', f);
 145
 146         /* We have the header.  Print the user's format into the buffer.  */
 147         vfprintf (f, fmt, ap);
 148
 149         /* Close the memory stream; this will finalize the data
 150            into a malloc'd buffer in BUF.  */
 151         fclose (f);
 152
 153         /* Output to stderr if requested. */
 154         if (LogStat & LOG_PERROR) {
 155                 struct iovec iov[2];
 156                 register struct iovec *v = iov;
 157
 158                 v->iov_base = buf + msgoff;
 159                 v->iov_len = bufsize - msgoff;
 160                 ++v;
 161                 v->iov_base = (char *) "\n";
 162                 v->iov_len = 1;
 163                 (void)writev(STDERR_FILENO, iov, 2);
 164         }
 165
 166         /* Get connected, output the message to the local logger. */
 167         if (!connected)
 168                 openlog(LogTag, LogStat | LOG_NDELAY, 0);
 169
 170         /* If we have a SOCK_STREAM connection, also send ASCII NUL as
 171            a record terminator.  */
 172         if (LogType == SOCK_STREAM)
 173           ++bufsize;
 174
 175         if (__send(LogFile, buf, bufsize, 0) < 0)
 176           {
 177             closelog ();        /* attempt re-open next time */
 178             /*
 179              * Output the message to the console; don't worry about blocking,
 180              * if console blocks everything will.  Make sure the error reported
 181              * is the one from the syslogd failure.
 182              */
 183             if (LogStat & LOG_CONS &&
 184                 (fd = open(_PATH_CONSOLE, O_WRONLY, 0)) >= 0)
 185               {
 186                 dprintf (fd, "%s\r\n", buf + msgoff);
 187                 (void)close(fd);
 188               }
 189           }
 190
 191         free (buf);
 192 }
 193
 194 static struct sockaddr SyslogAddr;      /* AF_UNIX address of local logger */
 195
 196 void
 197 openlog(ident, logstat, logfac)
 198         const char *ident;
 199         int logstat, logfac;
 200 {
 201         if (ident != NULL)
 202                 LogTag = ident;
 203         LogStat = logstat;
 204         if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
 205                 LogFacility = logfac;
 206
 207         while (1) {
 208                 if (LogFile == -1) {
 209                         SyslogAddr.sa_family = AF_UNIX;
 210                         (void)strncpy(SyslogAddr.sa_data, _PATH_LOG,
 211                                       sizeof(SyslogAddr.sa_data));
 212                         if (LogStat & LOG_NDELAY) {
 213                                 if ((LogFile = socket(AF_UNIX, LogType, 0))
 214                                     == -1)
 215                                         return;
 216                                 (void)fcntl(LogFile, F_SETFD, 1);
 217                         }
 218                 }
 219                 if (LogFile != -1 && !connected)
 220                         if (__connect(LogFile, &SyslogAddr, sizeof(SyslogAddr))
 221                             == -1)
 222                         {
 223                                 int saved_errno = errno;
 224                                 (void)close(LogFile);
 225                                 LogFile = -1;
 226                                 if (LogType == SOCK_DGRAM
 227                                     && saved_errno == EPROTOTYPE)
 228                                 {
 229                                         /* retry with next SOCK_STREAM: */
 230                                         LogType = SOCK_STREAM;
 231                                         continue;
 232                                 }
 233                         } else
 234                                 connected = 1;
 235                 break;
 236         }
 237 }
 238
 239 void
 240 closelog()
 241 {
 242         (void)close(LogFile);
 243         LogFile = -1;
 244         connected = 0;
 245 }
 246
 247 /* setlogmask -- set the log mask level */
 248 int
 249 setlogmask(pmask)
 250         int pmask;
 251 {
 252         int omask;
 253
 254         omask = LogMask;
 255         if (pmask != 0)
 256                 LogMask = pmask;
 257         return (omask);
 258 }