gen/syslog.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Copyright (c) 1993
  27  *      The Regents of the University of California.  All rights reserved.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 3. All advertising materials mentioning features or use of this software
  38  *    must display the following acknowledgement:
  39  *      This product includes software developed by the University of
  40  *      California, Berkeley and its contributors.
  41  * 4. Neither the name of the University nor the names of its contributors
  42  *    may be used to endorse or promote products derived from this software
  43  *    without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  55  * SUCH DAMAGE.
  56  */
  57
  58 #include <sys/types.h>
  59 #include <sys/socket.h>
  60 #include <sys/syslog.h>
  61 #include <sys/uio.h>
  62 #include <sys/un.h>
  63 #include <netdb.h>
  64
  65 #include <errno.h>
  66 #include <fcntl.h>
  67 #include <paths.h>
  68 #include <stdio.h>
  69 #include <string.h>
  70 #include <time.h>
  71 #include <unistd.h>
  72
  73 #ifdef __STDC__
  74 #include <stdarg.h>
  75 #else
  76 #include <varargs.h>
  77 #endif
  78
  79 #include <crt_externs.h>
  80
  81 static int      LogFile = -1;           /* fd for log */
  82 static int      connected;              /* have done connect */
  83 static int      LogStat = 0;            /* status bits, set by openlog() */
  84 static const char *LogTag = NULL;       /* string to tag the entry with */
  85 static int      LogFacility = LOG_USER; /* default facility code */
  86 static int      LogMask = 0xff;         /* mask of priorities to be logged */
  87
  88 /*
  89  * syslog, vsyslog --
  90  *      print message on log file; output is intended for syslogd(8).
  91  */
  92 void
  93 #ifdef __STDC__
  94 syslog(int pri, const char *fmt, ...)
  95 #else
  96 syslog(pri, fmt, va_alist)
  97         int pri;
  98         char *fmt;
  99         va_dcl
 100 #endif
 101 {
 102         va_list ap;
 103
 104 #ifdef __STDC__
 105         va_start(ap, fmt);
 106 #else
 107         va_start(ap);
 108 #endif
 109         vsyslog(pri, fmt, ap);
 110         va_end(ap);
 111 }
 112
 113 void
 114 vsyslog(pri, fmt, ap)
 115         int pri;
 116         register const char *fmt;
 117         va_list ap;
 118 {
 119         register int cnt;
 120         register char ch, *p, *t;
 121         time_t now;
 122         int fd, saved_errno;
 123 #define TBUF_LEN        2048
 124 #define FMT_LEN         1024
 125         char *stdp, tbuf[TBUF_LEN], fmt_cpy[FMT_LEN];
 126         int tbuf_left, fmt_left, prlen;
 127
 128 #define INTERNALLOG     LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID
 129         /* Check for invalid bits. */
 130         if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) {
 131                 syslog(INTERNALLOG,
 132                     "syslog: unknown facility/priority: %x", pri);
 133                 pri &= LOG_PRIMASK|LOG_FACMASK;
 134         }
 135
 136         /* Check priority against setlogmask values. */
 137         if (!(LOG_MASK(LOG_PRI(pri)) & LogMask))
 138                 return;
 139
 140         saved_errno = errno;
 141
 142         /* Set default facility if none specified. */
 143         if ((pri & LOG_FACMASK) == 0)
 144                 pri |= LogFacility;
 145
 146         /* Build the message. */
 147
 148         /*
 149          * Although it's tempting, we can't ignore the possibility of
 150          * overflowing the buffer when assembling the "fixed" portion
 151          * of the message.  Strftime's "%h" directive expands to the
 152          * locale's abbreviated month name, but if the user has the
 153          * ability to construct to his own locale files, it may be
 154          * arbitrarily long.
 155          */
 156         (void)time(&now);
 157
 158         p = tbuf;
 159         tbuf_left = TBUF_LEN;
 160
 161 #define DEC()   \
 162         do {                                    \
 163                 if (prlen >= tbuf_left)         \
 164                         prlen = tbuf_left - 1;  \
 165                 p += prlen;                     \
 166                 tbuf_left -= prlen;             \
 167         } while (0)
 168
 169         prlen = snprintf(p, tbuf_left, "<%d>", pri);
 170         DEC();
 171
 172         prlen = strftime(p, tbuf_left, "%h %e %T ", localtime(&now));
 173         DEC();
 174
 175         if (LogStat & LOG_PERROR)
 176                 stdp = p;
 177         if (LogTag == NULL)
 178                 LogTag = *(*_NSGetArgv());
 179         if (LogTag != NULL) {
 180                 prlen = snprintf(p, tbuf_left, "%s", LogTag);
 181                 DEC();
 182         }
 183         if (LogStat & LOG_PID) {
 184                 prlen = snprintf(p, tbuf_left, "[%d]", getpid());
 185                 DEC();
 186         }
 187         if (LogTag != NULL) {
 188                 if (tbuf_left > 1) {
 189                         *p++ = ':';
 190                         tbuf_left--;
 191                 }
 192                 if (tbuf_left > 1) {
 193                         *p++ = ' ';
 194                         tbuf_left--;
 195                 }
 196         }
 197
 198         /*
 199          * We wouldn't need this mess if printf handled %m, or if
 200          * strerror() had been invented before syslog().
 201          */
 202         for (t = fmt_cpy, fmt_left = FMT_LEN; (ch = *fmt); ++fmt) {
 203                 if (ch == '%' && fmt[1] == 'm') {
 204                         ++fmt;
 205                         prlen = snprintf(t, fmt_left, "%s",
 206                             strerror(saved_errno));
 207                         if (prlen >= fmt_left)
 208                                 prlen = fmt_left - 1;
 209                         t += prlen;
 210                         fmt_left -= prlen;
 211                 } else {
 212                         if (fmt_left > 1) {
 213                                 *t++ = ch;
 214                                 fmt_left--;
 215                         }
 216                 }
 217         }
 218         *t = '\0';
 219
 220         prlen = vsnprintf(p, tbuf_left, fmt_cpy, ap);
 221         DEC();
 222         cnt = p - tbuf;
 223
 224         /* Output to stderr if requested. */
 225         if (LogStat & LOG_PERROR) {
 226                 struct iovec iov[2];
 227
 228                 iov[0].iov_base = stdp;
 229                 iov[0].iov_len = cnt - (stdp - tbuf);
 230                 iov[1].iov_base = "\n";
 231                 iov[1].iov_len = 1;
 232                 (void)writev(STDERR_FILENO, iov, 2);
 233         }
 234
 235         /* Get connected, output the message to the local logger. */
 236         if (!connected)
 237                 openlog(LogTag, LogStat | LOG_NDELAY, 0);
 238         if (send(LogFile, tbuf, cnt, 0) >= 0)
 239                 return;
 240
 241         /*
 242          * Output the message to the console; don't worry about blocking,
 243          * if console blocks everything will.  Make sure the error reported
 244          * is the one from the syslogd failure.
 245          */
 246         if (LogStat & LOG_CONS &&
 247             (fd = open(_PATH_CONSOLE, O_WRONLY, 0)) >= 0) {
 248                 struct iovec iov[2];
 249
 250                 p = strchr(tbuf, '>') + 1;
 251                 iov[0].iov_base = p;
 252                 iov[0].iov_len = cnt - (p - tbuf);
 253                 iov[1].iov_base = "\r\n";
 254                 iov[1].iov_len = 2;
 255                 (void)writev(fd, iov, 2);
 256                 (void)close(fd);
 257         }
 258 }
 259
 260 static struct sockaddr_un SyslogAddr;   /* AF_UNIX address of local logger */
 261
 262 void
 263 openlog(ident, logstat, logfac)
 264         const char *ident;
 265         int logstat, logfac;
 266 {
 267         if (ident != NULL)
 268                 LogTag = ident;
 269         LogStat = logstat;
 270         if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
 271                 LogFacility = logfac;
 272
 273         if (LogFile == -1) {
 274                 SyslogAddr.sun_family = AF_UNIX;
 275                 (void)strncpy(SyslogAddr.sun_path, _PATH_LOG,
 276                     sizeof(SyslogAddr.sun_path));
 277                 if (LogStat & LOG_NDELAY) {
 278                         if ((LogFile = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1)
 279                                 return;
 280                         (void)fcntl(LogFile, F_SETFD, 1);
 281                 }
 282         }
 283         if (LogFile != -1 && !connected)
 284                 if (connect(LogFile, (struct sockaddr *)&SyslogAddr, sizeof(SyslogAddr)) == -1) {
 285                         (void)close(LogFile);
 286                         LogFile = -1;
 287                 } else
 288                         connected = 1;
 289 }
 290
 291 void
 292 closelog()
 293 {
 294         (void)close(LogFile);
 295         LogFile = -1;
 296         connected = 0;
 297 }
 298
 299 /* setlogmask -- set the log mask level */
 300 int
 301 setlogmask(pmask)
 302         int pmask;
 303 {
 304         int omask;
 305
 306         omask = LogMask;
 307         if (pmask != 0)
 308                 LogMask = pmask;
 309         return (omask);
 310 }