gen/syslog.c

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