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 1.5 2004/07/27 07:59:10 asmodai 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 #include <stdarg.h> 54 55 static int LogFile = -1; /* fd for log */ 56 static int connected; /* have done connect */ 57 static int opened; /* have done openlog() */ 58 static int LogStat = 0; /* status bits, set by openlog() */ 59 static const char *LogTag = NULL; /* string to tag the entry with */ 60 static int LogFacility = LOG_USER; /* default facility code */ 61 static int LogMask = 0xff; /* mask of priorities to be logged */ 62 extern char *__progname; /* Program name, from crt0. */ 63 64 static void disconnectlog (void); /* disconnect from syslogd */ 65 static void connectlog (void); /* (re)connect to syslogd */ 66 67 /* 68 * Format of the magic cookie passed through the stdio hook 69 */ 70 struct bufcookie { 71 char *base; /* start of buffer */ 72 int left; 73 }; 74 75 /* 76 * stdio write hook for writing to a static string buffer 77 * XXX: Maybe one day, dynamically allocate it so that the line length 78 * is `unlimited'. 79 */ 80 static 81 int writehook(cookie, buf, len) 82 void *cookie; /* really [struct bufcookie *] */ 83 char *buf; /* characters to copy */ 84 int len; /* length to copy */ 85 { 86 struct bufcookie *h; /* private `handle' */ 87 88 h = (struct bufcookie *)cookie; 89 if (len > h->left) { 90 /* clip in case of wraparound */ 91 len = h->left; 92 } 93 if (len > 0) { 94 (void)memcpy(h->base, buf, len); /* `write' it. */ 95 h->base += len; 96 h->left -= len; 97 } 98 return 0; 99 } 100 101 /* 102 * syslog, vsyslog -- 103 * print message on log file; output is intended for syslogd(8). 104 */ 105 void 106 syslog(int pri, const char *fmt, ...) 107 { 108 va_list ap; 109 110 va_start(ap, fmt); 111 vsyslog(pri, fmt, ap); 112 va_end(ap); 113 } 114 115 void 116 vsyslog(pri, fmt, ap) 117 int pri; 118 const char *fmt; 119 va_list ap; 120 { 121 int cnt; 122 char ch, *p; 123 time_t now; 124 int fd, saved_errno; 125 char *stdp, tbuf[2048], fmt_cpy[1024], timbuf[26]; 126 FILE *fp, *fmt_fp; 127 struct bufcookie tbuf_cookie; 128 struct bufcookie fmt_cookie; 129 130 #define INTERNALLOG LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID 131 /* Check for invalid bits. */ 132 if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) { 133 syslog(INTERNALLOG, 134 "syslog: unknown facility/priority: %x", pri); 135 pri &= LOG_PRIMASK|LOG_FACMASK; 136 } 137 138 /* Check priority against setlogmask values. */ 139 if (!(LOG_MASK(LOG_PRI(pri)) & LogMask)) 140 return; 141 142 saved_errno = errno; 143 144 /* Set default facility if none specified. */ 145 if ((pri & LOG_FACMASK) == 0) 146 pri |= LogFacility; 147 148 /* Create the primary stdio hook */ 149 tbuf_cookie.base = tbuf; 150 tbuf_cookie.left = sizeof(tbuf); 151 fp = fwopen(&tbuf_cookie, writehook); 152 if (fp == NULL) 153 return; 154 155 /* Build the message. */ 156 (void)time(&now); 157 (void)fprintf(fp, "<%d>", pri); 158 (void)fprintf(fp, "%.15s ", ctime_r(&now, timbuf) + 4); 159 if (LogStat & LOG_PERROR) { 160 /* Transfer to string buffer */ 161 (void)fflush(fp); 162 stdp = tbuf + (sizeof(tbuf) - tbuf_cookie.left); 163 } 164 if (LogTag == NULL) 165 LogTag = __progname; 166 if (LogTag != NULL) 167 (void)fprintf(fp, "%s", LogTag); 168 if (LogStat & LOG_PID) 169 (void)fprintf(fp, "[%d]", getpid()); 170 if (LogTag != NULL) { 171 (void)fprintf(fp, ": "); 172 } 173 174 /* Check to see if we can skip expanding the %m */ 175 if (strstr(fmt, "%m")) { 176 177 /* Create the second stdio hook */ 178 fmt_cookie.base = fmt_cpy; 179 fmt_cookie.left = sizeof(fmt_cpy) - 1; 180 fmt_fp = fwopen(&fmt_cookie, writehook); 181 if (fmt_fp == NULL) { 182 fclose(fp); 183 return; 184 } 185 186 /* Substitute error message for %m. */ 187 for ( ; (ch = *fmt); ++fmt) 188 if (ch == '%' && fmt[1] == 'm') { 189 ++fmt; 190 fputs(strerror(saved_errno), fmt_fp); 191 } else 192 fputc(ch, fmt_fp); 193 194 /* Null terminate if room */ 195 fputc(0, fmt_fp); 196 fclose(fmt_fp); 197 198 /* Guarantee null termination */ 199 fmt_cpy[sizeof(fmt_cpy) - 1] = '\0'; 200 201 fmt = fmt_cpy; 202 } 203 204 (void)vfprintf(fp, fmt, ap); 205 (void)fclose(fp); 206 207 cnt = sizeof(tbuf) - tbuf_cookie.left; 208 209 /* Output to stderr if requested. */ 210 if (LogStat & LOG_PERROR) { 211 struct iovec iov[2]; 212 struct iovec *v = iov; 213 214 v->iov_base = stdp; 215 v->iov_len = cnt - (stdp - tbuf); 216 ++v; 217 v->iov_base = "\n"; 218 v->iov_len = 1; 219 (void)writev(STDERR_FILENO, iov, 2); 220 } 221 222 /* Get connected, output the message to the local logger. */ 223 if (!opened) 224 openlog(LogTag, LogStat | LOG_NDELAY, 0); 225 connectlog(); 226 if (send(LogFile, tbuf, cnt, 0) >= 0) 227 return; 228 229 /* 230 * If the send() failed, the odds are syslogd was restarted. 231 * Make one (only) attempt to reconnect to /dev/log. 232 */ 233 disconnectlog(); 234 connectlog(); 235 if (send(LogFile, tbuf, cnt, 0) >= 0) 236 return; 237 238 /* 239 * Output the message to the console; try not to block 240 * as a blocking console should not stop other processes. 241 * Make sure the error reported is the one from the syslogd failure. 242 */ 243 if (LogStat & LOG_CONS && 244 (fd = _open(_PATH_CONSOLE, O_WRONLY|O_NONBLOCK, 0)) >= 0) { 245 struct iovec iov[2]; 246 struct iovec *v = iov; 247 248 p = strchr(tbuf, '>') + 1; 249 v->iov_base = p; 250 v->iov_len = cnt - (p - tbuf); 251 ++v; 252 v->iov_base = "\r\n"; 253 v->iov_len = 2; 254 (void)writev(fd, iov, 2); 255 (void)_close(fd); 256 } 257 } 258 static void 259 disconnectlog() 260 { 261 /* 262 * If the user closed the FD and opened another in the same slot, 263 * that's their problem. They should close it before calling on 264 * system services. 265 */ 266 if (LogFile != -1) { 267 _close(LogFile); 268 LogFile = -1; 269 } 270 connected = 0; /* retry connect */ 271 } 272 273 static void 274 connectlog() 275 { 276 struct sockaddr_un SyslogAddr; /* AF_UNIX address of local logger */ 277 278 if (LogFile == -1) { 279 if ((LogFile = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1) 280 return; 281 (void)_fcntl(LogFile, F_SETFD, 1); 282 } 283 if (LogFile != -1 && !connected) { 284 SyslogAddr.sun_len = sizeof(SyslogAddr); 285 SyslogAddr.sun_family = AF_UNIX; 286 (void)strncpy(SyslogAddr.sun_path, _PATH_LOG, 287 sizeof SyslogAddr.sun_path); 288 connected = connect(LogFile, (struct sockaddr *)&SyslogAddr, 289 sizeof(SyslogAddr)) != -1; 290 291 if (!connected) { 292 /* 293 * Try the old "/dev/log" path, for backward 294 * compatibility. 295 */ 296 (void)strncpy(SyslogAddr.sun_path, _PATH_OLDLOG, 297 sizeof SyslogAddr.sun_path); 298 connected = connect(LogFile, 299 (struct sockaddr *)&SyslogAddr, 300 sizeof(SyslogAddr)) != -1; 301 } 302 303 if (!connected) { 304 (void)_close(LogFile); 305 LogFile = -1; 306 } 307 } 308 } 309 310 void 311 openlog(ident, logstat, logfac) 312 const char *ident; 313 int logstat, logfac; 314 { 315 if (ident != NULL) 316 LogTag = ident; 317 LogStat = logstat; 318 if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0) 319 LogFacility = logfac; 320 321 if (LogStat & LOG_NDELAY) /* open immediately */ 322 connectlog(); 323 324 opened = 1; /* ident and facility has been set */ 325 } 326 327 void 328 closelog() 329 { 330 (void)_close(LogFile); 331 LogFile = -1; 332 LogTag = NULL; 333 connected = 0; 334 } 335 336 /* setlogmask -- set the log mask level */ 337 int 338 setlogmask(pmask) 339 int pmask; 340 { 341 int omask; 342 343 omask = LogMask; 344 if (pmask != 0) 345 LogMask = pmask; 346 return (omask); 347 } 348