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 1.7 2005/03/09 18:52:21 joerg Exp $ 36 */ 37 38 #include "namespace.h" 39 #include <sys/types.h> 40 #include <sys/socket.h> 41 #include <sys/syslog.h> 42 #include <sys/uio.h> 43 #include <sys/un.h> 44 #include <netdb.h> 45 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <paths.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <time.h> 53 #include <unistd.h> 54 #include "un-namespace.h" 55 56 #include <stdarg.h> 57 58 static int LogFile = -1; /* fd for log */ 59 static int connected; /* have done connect */ 60 static int opened; /* have done openlog() */ 61 static int LogStat = 0; /* status bits, set by openlog() */ 62 static const char *LogTag = NULL; /* string to tag the entry with */ 63 static int LogFacility = LOG_USER; /* default facility code */ 64 static int LogMask = 0xff; /* mask of priorities to be logged */ 65 66 static void disconnectlog (void); /* disconnect from syslogd */ 67 static void connectlog (void); /* (re)connect to syslogd */ 68 69 /* 70 * Format of the magic cookie passed through the stdio hook 71 */ 72 struct bufcookie { 73 char *base; /* start of buffer */ 74 int left; 75 }; 76 77 /* 78 * stdio write hook for writing to a static string buffer 79 * XXX: Maybe one day, dynamically allocate it so that the line length 80 * is `unlimited'. 81 */ 82 static 83 int writehook(cookie, buf, len) 84 void *cookie; /* really [struct bufcookie *] */ 85 char *buf; /* characters to copy */ 86 int len; /* length to copy */ 87 { 88 struct bufcookie *h; /* private `handle' */ 89 90 h = (struct bufcookie *)cookie; 91 if (len > h->left) { 92 /* clip in case of wraparound */ 93 len = h->left; 94 } 95 if (len > 0) { 96 (void)memcpy(h->base, buf, len); /* `write' it. */ 97 h->base += len; 98 h->left -= len; 99 } 100 return 0; 101 } 102 103 /* 104 * syslog, vsyslog -- 105 * print message on log file; output is intended for syslogd(8). 106 */ 107 void 108 syslog(int pri, const char *fmt, ...) 109 { 110 va_list ap; 111 112 va_start(ap, fmt); 113 vsyslog(pri, fmt, ap); 114 va_end(ap); 115 } 116 117 void 118 vsyslog(pri, fmt, ap) 119 int pri; 120 const char *fmt; 121 va_list ap; 122 { 123 int cnt; 124 char ch, *p; 125 time_t now; 126 int fd, saved_errno; 127 char *stdp, tbuf[2048], fmt_cpy[1024], timbuf[26]; 128 FILE *fp, *fmt_fp; 129 struct bufcookie tbuf_cookie; 130 struct bufcookie fmt_cookie; 131 132 #define INTERNALLOG LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID 133 /* Check for invalid bits. */ 134 if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) { 135 syslog(INTERNALLOG, 136 "syslog: unknown facility/priority: %x", pri); 137 pri &= LOG_PRIMASK|LOG_FACMASK; 138 } 139 140 /* Check priority against setlogmask values. */ 141 if (!(LOG_MASK(LOG_PRI(pri)) & LogMask)) 142 return; 143 144 saved_errno = errno; 145 146 /* Set default facility if none specified. */ 147 if ((pri & LOG_FACMASK) == 0) 148 pri |= LogFacility; 149 150 /* Create the primary stdio hook */ 151 tbuf_cookie.base = tbuf; 152 tbuf_cookie.left = sizeof(tbuf); 153 fp = fwopen(&tbuf_cookie, writehook); 154 if (fp == NULL) 155 return; 156 157 /* Build the message. */ 158 (void)time(&now); 159 (void)fprintf(fp, "<%d>", pri); 160 (void)fprintf(fp, "%.15s ", ctime_r(&now, timbuf) + 4); 161 if (LogStat & LOG_PERROR) { 162 /* Transfer to string buffer */ 163 (void)fflush(fp); 164 stdp = tbuf + (sizeof(tbuf) - tbuf_cookie.left); 165 } 166 if (LogTag == NULL) 167 LogTag = getprogname(); 168 if (LogTag != NULL) 169 (void)fprintf(fp, "%s", LogTag); 170 if (LogStat & LOG_PID) 171 (void)fprintf(fp, "[%d]", getpid()); 172 if (LogTag != NULL) { 173 (void)fprintf(fp, ": "); 174 } 175 176 /* Check to see if we can skip expanding the %m */ 177 if (strstr(fmt, "%m")) { 178 179 /* Create the second stdio hook */ 180 fmt_cookie.base = fmt_cpy; 181 fmt_cookie.left = sizeof(fmt_cpy) - 1; 182 fmt_fp = fwopen(&fmt_cookie, writehook); 183 if (fmt_fp == NULL) { 184 fclose(fp); 185 return; 186 } 187 188 /* Substitute error message for %m. */ 189 for ( ; (ch = *fmt); ++fmt) 190 if (ch == '%' && fmt[1] == 'm') { 191 ++fmt; 192 fputs(strerror(saved_errno), fmt_fp); 193 } else 194 fputc(ch, fmt_fp); 195 196 /* Null terminate if room */ 197 fputc(0, fmt_fp); 198 fclose(fmt_fp); 199 200 /* Guarantee null termination */ 201 fmt_cpy[sizeof(fmt_cpy) - 1] = '\0'; 202 203 fmt = fmt_cpy; 204 } 205 206 (void)vfprintf(fp, fmt, ap); 207 (void)fclose(fp); 208 209 cnt = sizeof(tbuf) - tbuf_cookie.left; 210 211 /* Output to stderr if requested. */ 212 if (LogStat & LOG_PERROR) { 213 struct iovec iov[2]; 214 struct iovec *v = iov; 215 216 v->iov_base = stdp; 217 v->iov_len = cnt - (stdp - tbuf); 218 ++v; 219 v->iov_base = "\n"; 220 v->iov_len = 1; 221 (void)_writev(STDERR_FILENO, iov, 2); 222 } 223 224 /* Get connected, output the message to the local logger. */ 225 if (!opened) 226 openlog(LogTag, LogStat | LOG_NDELAY, 0); 227 connectlog(); 228 if (send(LogFile, tbuf, cnt, 0) >= 0) 229 return; 230 231 /* 232 * If the send() failed, the odds are syslogd was restarted. 233 * Make one (only) attempt to reconnect to /dev/log. 234 */ 235 disconnectlog(); 236 connectlog(); 237 if (send(LogFile, tbuf, cnt, 0) >= 0) 238 return; 239 240 /* 241 * Output the message to the console; try not to block 242 * as a blocking console should not stop other processes. 243 * Make sure the error reported is the one from the syslogd failure. 244 */ 245 if (LogStat & LOG_CONS && 246 (fd = _open(_PATH_CONSOLE, O_WRONLY|O_NONBLOCK, 0)) >= 0) { 247 struct iovec iov[2]; 248 struct iovec *v = iov; 249 250 p = strchr(tbuf, '>') + 1; 251 v->iov_base = p; 252 v->iov_len = cnt - (p - tbuf); 253 ++v; 254 v->iov_base = "\r\n"; 255 v->iov_len = 2; 256 (void)_writev(fd, iov, 2); 257 (void)_close(fd); 258 } 259 } 260 static void 261 disconnectlog() 262 { 263 /* 264 * If the user closed the FD and opened another in the same slot, 265 * that's their problem. They should close it before calling on 266 * system services. 267 */ 268 if (LogFile != -1) { 269 _close(LogFile); 270 LogFile = -1; 271 } 272 connected = 0; /* retry connect */ 273 } 274 275 static void 276 connectlog() 277 { 278 struct sockaddr_un SyslogAddr; /* AF_UNIX address of local logger */ 279 280 if (LogFile == -1) { 281 if ((LogFile = _socket(AF_UNIX, SOCK_DGRAM, 0)) == -1) 282 return; 283 (void)_fcntl(LogFile, F_SETFD, 1); 284 } 285 if (LogFile != -1 && !connected) { 286 SyslogAddr.sun_len = sizeof(SyslogAddr); 287 SyslogAddr.sun_family = AF_UNIX; 288 (void)strncpy(SyslogAddr.sun_path, _PATH_LOG, 289 sizeof SyslogAddr.sun_path); 290 connected = _connect(LogFile, (struct sockaddr *)&SyslogAddr, 291 sizeof(SyslogAddr)) != -1; 292 293 if (!connected) { 294 /* 295 * Try the old "/dev/log" path, for backward 296 * compatibility. 297 */ 298 (void)strncpy(SyslogAddr.sun_path, _PATH_OLDLOG, 299 sizeof SyslogAddr.sun_path); 300 connected = _connect(LogFile, 301 (struct sockaddr *)&SyslogAddr, 302 sizeof(SyslogAddr)) != -1; 303 } 304 305 if (!connected) { 306 (void)_close(LogFile); 307 LogFile = -1; 308 } 309 } 310 } 311 312 void 313 openlog(ident, logstat, logfac) 314 const char *ident; 315 int logstat, logfac; 316 { 317 if (ident != NULL) 318 LogTag = ident; 319 LogStat = logstat; 320 if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0) 321 LogFacility = logfac; 322 323 if (LogStat & LOG_NDELAY) /* open immediately */ 324 connectlog(); 325 326 opened = 1; /* ident and facility has been set */ 327 } 328 329 void 330 closelog() 331 { 332 (void)_close(LogFile); 333 LogFile = -1; 334 LogTag = NULL; 335 connected = 0; 336 } 337 338 /* setlogmask -- set the log mask level */ 339 int 340 setlogmask(pmask) 341 int pmask; 342 { 343 int omask; 344 345 omask = LogMask; 346 if (pmask != 0) 347 LogMask = pmask; 348 return (omask); 349 } 350