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 * @(#)syslog.c 8.5 (Berkeley) 4/29/95 34 * $FreeBSD: src/lib/libc/gen/syslog.c,v 1.21.2.3 2002/11/18 11:49:55 ru Exp $ 35 * $DragonFly: src/lib/libc/gen/syslog.c,v 1.3 2003/11/12 20:21:23 eirikn Exp $ 36 */ 37 38 #include <sys/types.h> 39 #include <sys/socket.h> 40 #include <sys/syslog.h> 41 #include <sys/uio.h> 42 #include <sys/un.h> 43 #include <netdb.h> 44 45 #include <errno.h> 46 #include <fcntl.h> 47 #include <paths.h> 48 #include <stdio.h> 49 #include <string.h> 50 #include <time.h> 51 #include <unistd.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 opened; /* have done openlog() */ 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 static void disconnectlog (void); /* disconnect from syslogd */ 69 static void connectlog (void); /* (re)connect to syslogd */ 70 71 /* 72 * Format of the magic cookie passed through the stdio hook 73 */ 74 struct bufcookie { 75 char *base; /* start of buffer */ 76 int left; 77 }; 78 79 /* 80 * stdio write hook for writing to a static string buffer 81 * XXX: Maybe one day, dynamically allocate it so that the line length 82 * is `unlimited'. 83 */ 84 static 85 int writehook(cookie, buf, len) 86 void *cookie; /* really [struct bufcookie *] */ 87 char *buf; /* characters to copy */ 88 int len; /* length to copy */ 89 { 90 struct bufcookie *h; /* private `handle' */ 91 92 h = (struct bufcookie *)cookie; 93 if (len > h->left) { 94 /* clip in case of wraparound */ 95 len = h->left; 96 } 97 if (len > 0) { 98 (void)memcpy(h->base, buf, len); /* `write' it. */ 99 h->base += len; 100 h->left -= len; 101 } 102 return 0; 103 } 104 105 /* 106 * syslog, vsyslog -- 107 * print message on log file; output is intended for syslogd(8). 108 */ 109 void 110 #if __STDC__ 111 syslog(int pri, const char *fmt, ...) 112 #else 113 syslog(pri, fmt, va_alist) 114 int pri; 115 char *fmt; 116 va_dcl 117 #endif 118 { 119 va_list ap; 120 121 #if __STDC__ 122 va_start(ap, fmt); 123 #else 124 va_start(ap); 125 #endif 126 vsyslog(pri, fmt, ap); 127 va_end(ap); 128 } 129 130 void 131 vsyslog(pri, fmt, ap) 132 int pri; 133 register const char *fmt; 134 va_list ap; 135 { 136 register int cnt; 137 register char ch, *p; 138 time_t now; 139 int fd, saved_errno; 140 char *stdp, tbuf[2048], fmt_cpy[1024], timbuf[26]; 141 FILE *fp, *fmt_fp; 142 struct bufcookie tbuf_cookie; 143 struct bufcookie fmt_cookie; 144 145 #define INTERNALLOG LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID 146 /* Check for invalid bits. */ 147 if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) { 148 syslog(INTERNALLOG, 149 "syslog: unknown facility/priority: %x", pri); 150 pri &= LOG_PRIMASK|LOG_FACMASK; 151 } 152 153 /* Check priority against setlogmask values. */ 154 if (!(LOG_MASK(LOG_PRI(pri)) & LogMask)) 155 return; 156 157 saved_errno = errno; 158 159 /* Set default facility if none specified. */ 160 if ((pri & LOG_FACMASK) == 0) 161 pri |= LogFacility; 162 163 /* Create the primary stdio hook */ 164 tbuf_cookie.base = tbuf; 165 tbuf_cookie.left = sizeof(tbuf); 166 fp = fwopen(&tbuf_cookie, writehook); 167 if (fp == NULL) 168 return; 169 170 /* Build the message. */ 171 (void)time(&now); 172 (void)fprintf(fp, "<%d>", pri); 173 (void)fprintf(fp, "%.15s ", ctime_r(&now, timbuf) + 4); 174 if (LogStat & LOG_PERROR) { 175 /* Transfer to string buffer */ 176 (void)fflush(fp); 177 stdp = tbuf + (sizeof(tbuf) - tbuf_cookie.left); 178 } 179 if (LogTag == NULL) 180 LogTag = __progname; 181 if (LogTag != NULL) 182 (void)fprintf(fp, "%s", LogTag); 183 if (LogStat & LOG_PID) 184 (void)fprintf(fp, "[%d]", getpid()); 185 if (LogTag != NULL) { 186 (void)fprintf(fp, ": "); 187 } 188 189 /* Check to see if we can skip expanding the %m */ 190 if (strstr(fmt, "%m")) { 191 192 /* Create the second stdio hook */ 193 fmt_cookie.base = fmt_cpy; 194 fmt_cookie.left = sizeof(fmt_cpy) - 1; 195 fmt_fp = fwopen(&fmt_cookie, writehook); 196 if (fmt_fp == NULL) { 197 fclose(fp); 198 return; 199 } 200 201 /* Substitute error message for %m. */ 202 for ( ; (ch = *fmt); ++fmt) 203 if (ch == '%' && fmt[1] == 'm') { 204 ++fmt; 205 fputs(strerror(saved_errno), fmt_fp); 206 } else 207 fputc(ch, fmt_fp); 208 209 /* Null terminate if room */ 210 fputc(0, fmt_fp); 211 fclose(fmt_fp); 212 213 /* Guarantee null termination */ 214 fmt_cpy[sizeof(fmt_cpy) - 1] = '\0'; 215 216 fmt = fmt_cpy; 217 } 218 219 (void)vfprintf(fp, fmt, ap); 220 (void)fclose(fp); 221 222 cnt = sizeof(tbuf) - tbuf_cookie.left; 223 224 /* Output to stderr if requested. */ 225 if (LogStat & LOG_PERROR) { 226 struct iovec iov[2]; 227 register struct iovec *v = iov; 228 229 v->iov_base = stdp; 230 v->iov_len = cnt - (stdp - tbuf); 231 ++v; 232 v->iov_base = "\n"; 233 v->iov_len = 1; 234 (void)writev(STDERR_FILENO, iov, 2); 235 } 236 237 /* Get connected, output the message to the local logger. */ 238 if (!opened) 239 openlog(LogTag, LogStat | LOG_NDELAY, 0); 240 connectlog(); 241 if (send(LogFile, tbuf, cnt, 0) >= 0) 242 return; 243 244 /* 245 * If the send() failed, the odds are syslogd was restarted. 246 * Make one (only) attempt to reconnect to /dev/log. 247 */ 248 disconnectlog(); 249 connectlog(); 250 if (send(LogFile, tbuf, cnt, 0) >= 0) 251 return; 252 253 /* 254 * Output the message to the console; try not to block 255 * as a blocking console should not stop other processes. 256 * Make sure the error reported is the one from the syslogd failure. 257 */ 258 if (LogStat & LOG_CONS && 259 (fd = _open(_PATH_CONSOLE, O_WRONLY|O_NONBLOCK, 0)) >= 0) { 260 struct iovec iov[2]; 261 register struct iovec *v = iov; 262 263 p = strchr(tbuf, '>') + 1; 264 v->iov_base = p; 265 v->iov_len = cnt - (p - tbuf); 266 ++v; 267 v->iov_base = "\r\n"; 268 v->iov_len = 2; 269 (void)writev(fd, iov, 2); 270 (void)_close(fd); 271 } 272 } 273 static void 274 disconnectlog() 275 { 276 /* 277 * If the user closed the FD and opened another in the same slot, 278 * that's their problem. They should close it before calling on 279 * system services. 280 */ 281 if (LogFile != -1) { 282 _close(LogFile); 283 LogFile = -1; 284 } 285 connected = 0; /* retry connect */ 286 } 287 288 static void 289 connectlog() 290 { 291 struct sockaddr_un SyslogAddr; /* AF_UNIX address of local logger */ 292 293 if (LogFile == -1) { 294 if ((LogFile = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1) 295 return; 296 (void)_fcntl(LogFile, F_SETFD, 1); 297 } 298 if (LogFile != -1 && !connected) { 299 SyslogAddr.sun_len = sizeof(SyslogAddr); 300 SyslogAddr.sun_family = AF_UNIX; 301 (void)strncpy(SyslogAddr.sun_path, _PATH_LOG, 302 sizeof SyslogAddr.sun_path); 303 connected = connect(LogFile, (struct sockaddr *)&SyslogAddr, 304 sizeof(SyslogAddr)) != -1; 305 306 if (!connected) { 307 /* 308 * Try the old "/dev/log" path, for backward 309 * compatibility. 310 */ 311 (void)strncpy(SyslogAddr.sun_path, _PATH_OLDLOG, 312 sizeof SyslogAddr.sun_path); 313 connected = connect(LogFile, 314 (struct sockaddr *)&SyslogAddr, 315 sizeof(SyslogAddr)) != -1; 316 } 317 318 if (!connected) { 319 (void)_close(LogFile); 320 LogFile = -1; 321 } 322 } 323 } 324 325 void 326 openlog(ident, logstat, logfac) 327 const char *ident; 328 int logstat, logfac; 329 { 330 if (ident != NULL) 331 LogTag = ident; 332 LogStat = logstat; 333 if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0) 334 LogFacility = logfac; 335 336 if (LogStat & LOG_NDELAY) /* open immediately */ 337 connectlog(); 338 339 opened = 1; /* ident and facility has been set */ 340 } 341 342 void 343 closelog() 344 { 345 (void)_close(LogFile); 346 LogFile = -1; 347 LogTag = NULL; 348 connected = 0; 349 } 350 351 /* setlogmask -- set the log mask level */ 352 int 353 setlogmask(pmask) 354 int pmask; 355 { 356 int omask; 357 358 omask = LogMask; 359 if (pmask != 0) 360 LogMask = pmask; 361 return (omask); 362 } 363