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 8.5 (Berkeley) 4/29/95"; 36 #endif /* LIBC_SCCS and not lint */ 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "namespace.h" 41 #include <sys/types.h> 42 #include <sys/socket.h> 43 #include <sys/syslog.h> 44 #include <sys/uio.h> 45 #include <sys/un.h> 46 #include <netdb.h> 47 48 #include <errno.h> 49 #include <fcntl.h> 50 #include <paths.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <time.h> 55 #include <unistd.h> 56 57 #include <stdarg.h> 58 #include "un-namespace.h" 59 60 #include "libc_private.h" 61 62 static int LogFile = -1; /* fd for log */ 63 static int connected; /* have done connect */ 64 static int opened; /* have done openlog() */ 65 static int LogStat = 0; /* status bits, set by openlog() */ 66 static const char *LogTag = NULL; /* string to tag the entry with */ 67 static int LogFacility = LOG_USER; /* default facility code */ 68 static int LogMask = 0xff; /* mask of priorities to be logged */ 69 70 static void disconnectlog(void); /* disconnect from syslogd */ 71 static void connectlog(void); /* (re)connect to syslogd */ 72 73 /* 74 * Format of the magic cookie passed through the stdio hook 75 */ 76 struct bufcookie { 77 char *base; /* start of buffer */ 78 int left; 79 }; 80 81 /* 82 * stdio write hook for writing to a static string buffer 83 * XXX: Maybe one day, dynamically allocate it so that the line length 84 * is `unlimited'. 85 */ 86 static 87 int writehook(cookie, buf, len) 88 void *cookie; /* really [struct bufcookie *] */ 89 char *buf; /* characters to copy */ 90 int len; /* length to copy */ 91 { 92 struct bufcookie *h; /* private `handle' */ 93 94 h = (struct bufcookie *)cookie; 95 if (len > h->left) { 96 /* clip in case of wraparound */ 97 len = h->left; 98 } 99 if (len > 0) { 100 (void)memcpy(h->base, buf, len); /* `write' it. */ 101 h->base += len; 102 h->left -= len; 103 } 104 return 0; 105 } 106 107 /* 108 * syslog, vsyslog -- 109 * print message on log file; output is intended for syslogd(8). 110 */ 111 void 112 syslog(int pri, const char *fmt, ...) 113 { 114 va_list ap; 115 116 va_start(ap, fmt); 117 vsyslog(pri, fmt, ap); 118 va_end(ap); 119 } 120 121 void 122 vsyslog(pri, fmt, ap) 123 int pri; 124 const char *fmt; 125 va_list ap; 126 { 127 int cnt; 128 char ch, *p; 129 time_t now; 130 int fd, saved_errno; 131 char *stdp, tbuf[2048], fmt_cpy[1024], timbuf[26]; 132 FILE *fp, *fmt_fp; 133 struct bufcookie tbuf_cookie; 134 struct bufcookie fmt_cookie; 135 136 #define INTERNALLOG LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID 137 /* Check for invalid bits. */ 138 if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) { 139 syslog(INTERNALLOG, 140 "syslog: unknown facility/priority: %x", pri); 141 pri &= LOG_PRIMASK|LOG_FACMASK; 142 } 143 144 /* Check priority against setlogmask values. */ 145 if (!(LOG_MASK(LOG_PRI(pri)) & LogMask)) 146 return; 147 148 saved_errno = errno; 149 150 /* Set default facility if none specified. */ 151 if ((pri & LOG_FACMASK) == 0) 152 pri |= LogFacility; 153 154 /* Create the primary stdio hook */ 155 tbuf_cookie.base = tbuf; 156 tbuf_cookie.left = sizeof(tbuf); 157 fp = fwopen(&tbuf_cookie, writehook); 158 if (fp == NULL) 159 return; 160 161 /* Build the message. */ 162 (void)time(&now); 163 (void)fprintf(fp, "<%d>", pri); 164 (void)fprintf(fp, "%.15s ", ctime_r(&now, timbuf) + 4); 165 if (LogStat & LOG_PERROR) { 166 /* Transfer to string buffer */ 167 (void)fflush(fp); 168 stdp = tbuf + (sizeof(tbuf) - tbuf_cookie.left); 169 } 170 if (LogTag == NULL) 171 LogTag = _getprogname(); 172 if (LogTag != NULL) 173 (void)fprintf(fp, "%s", LogTag); 174 if (LogStat & LOG_PID) 175 (void)fprintf(fp, "[%d]", getpid()); 176 if (LogTag != NULL) { 177 (void)fprintf(fp, ": "); 178 } 179 180 /* Check to see if we can skip expanding the %m */ 181 if (strstr(fmt, "%m")) { 182 183 /* Create the second stdio hook */ 184 fmt_cookie.base = fmt_cpy; 185 fmt_cookie.left = sizeof(fmt_cpy) - 1; 186 fmt_fp = fwopen(&fmt_cookie, writehook); 187 if (fmt_fp == NULL) { 188 fclose(fp); 189 return; 190 } 191 192 /* 193 * Substitute error message for %m. Be careful not to 194 * molest an escaped percent "%%m". We want to pass it 195 * on untouched as the format is later parsed by vfprintf. 196 */ 197 for ( ; (ch = *fmt); ++fmt) { 198 if (ch == '%' && fmt[1] == 'm') { 199 ++fmt; 200 fputs(strerror(saved_errno), fmt_fp); 201 } else if (ch == '%' && fmt[1] == '%') { 202 ++fmt; 203 fputc(ch, fmt_fp); 204 fputc(ch, fmt_fp); 205 } else { 206 fputc(ch, fmt_fp); 207 } 208 } 209 210 /* Null terminate if room */ 211 fputc(0, fmt_fp); 212 fclose(fmt_fp); 213 214 /* Guarantee null termination */ 215 fmt_cpy[sizeof(fmt_cpy) - 1] = '\0'; 216 217 fmt = fmt_cpy; 218 } 219 220 (void)vfprintf(fp, fmt, ap); 221 (void)fclose(fp); 222 223 cnt = sizeof(tbuf) - tbuf_cookie.left; 224 225 /* Output to stderr if requested. */ 226 if (LogStat & LOG_PERROR) { 227 struct iovec iov[2]; 228 struct iovec *v = iov; 229 230 v->iov_base = stdp; 231 v->iov_len = cnt - (stdp - tbuf); 232 ++v; 233 v->iov_base = "\n"; 234 v->iov_len = 1; 235 (void)_writev(STDERR_FILENO, iov, 2); 236 } 237 238 /* Get connected, output the message to the local logger. */ 239 if (!opened) 240 openlog(LogTag, LogStat | LOG_NDELAY, 0); 241 connectlog(); 242 if (send(LogFile, tbuf, cnt, 0) >= 0) 243 return; 244 245 /* 246 * If the send() failed, the odds are syslogd was restarted. 247 * Make one (only) attempt to reconnect to /dev/log. 248 */ 249 disconnectlog(); 250 connectlog(); 251 if (send(LogFile, tbuf, cnt, 0) >= 0) 252 return; 253 254 /* 255 * Output the message to the console; try not to block 256 * as a blocking console should not stop other processes. 257 * Make sure the error reported is the one from the syslogd failure. 258 */ 259 if (LogStat & LOG_CONS && 260 (fd = _open(_PATH_CONSOLE, O_WRONLY|O_NONBLOCK, 0)) >= 0) { 261 struct iovec iov[2]; 262 struct iovec *v = iov; 263 264 p = strchr(tbuf, '>') + 1; 265 v->iov_base = p; 266 v->iov_len = cnt - (p - tbuf); 267 ++v; 268 v->iov_base = "\r\n"; 269 v->iov_len = 2; 270 (void)_writev(fd, iov, 2); 271 (void)_close(fd); 272 } 273 } 274 static void 275 disconnectlog() 276 { 277 /* 278 * If the user closed the FD and opened another in the same slot, 279 * that's their problem. They should close it before calling on 280 * system services. 281 */ 282 if (LogFile != -1) { 283 _close(LogFile); 284 LogFile = -1; 285 } 286 connected = 0; /* retry connect */ 287 } 288 289 static void 290 connectlog() 291 { 292 struct sockaddr_un SyslogAddr; /* AF_UNIX address of local logger */ 293 294 if (LogFile == -1) { 295 if ((LogFile = _socket(AF_UNIX, SOCK_DGRAM, 0)) == -1) 296 return; 297 (void)_fcntl(LogFile, F_SETFD, 1); 298 } 299 if (LogFile != -1 && !connected) { 300 SyslogAddr.sun_len = sizeof(SyslogAddr); 301 SyslogAddr.sun_family = AF_UNIX; 302 (void)strncpy(SyslogAddr.sun_path, _PATH_LOG, 303 sizeof SyslogAddr.sun_path); 304 connected = _connect(LogFile, (struct sockaddr *)&SyslogAddr, 305 sizeof(SyslogAddr)) != -1; 306 307 if (!connected) { 308 /* 309 * Try the old "/dev/log" path, for backward 310 * compatibility. 311 */ 312 (void)strncpy(SyslogAddr.sun_path, _PATH_OLDLOG, 313 sizeof SyslogAddr.sun_path); 314 connected = _connect(LogFile, 315 (struct sockaddr *)&SyslogAddr, 316 sizeof(SyslogAddr)) != -1; 317 } 318 319 if (!connected) { 320 (void)_close(LogFile); 321 LogFile = -1; 322 } 323 } 324 } 325 326 void 327 openlog(ident, logstat, logfac) 328 const char *ident; 329 int logstat, logfac; 330 { 331 if (ident != NULL) 332 LogTag = ident; 333 LogStat = logstat; 334 if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0) 335 LogFacility = logfac; 336 337 if (LogStat & LOG_NDELAY) /* open immediately */ 338 connectlog(); 339 340 opened = 1; /* ident and facility has been set */ 341 } 342 343 void 344 closelog() 345 { 346 (void)_close(LogFile); 347 LogFile = -1; 348 LogTag = NULL; 349 connected = 0; 350 } 351 352 /* setlogmask -- set the log mask level */ 353 int 354 setlogmask(pmask) 355 int pmask; 356 { 357 int omask; 358 359 omask = LogMask; 360 if (pmask != 0) 361 LogMask = pmask; 362 return (omask); 363 } 364