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 1.9 2005/11/19 22:32:53 swildner 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 int 83 writehook(void *cookie, const char *buf, int len) 84 { 85 struct bufcookie *h; /* private `handle' */ 86 87 h = (struct bufcookie *)cookie; 88 if (len > h->left) { 89 /* clip in case of wraparound */ 90 len = h->left; 91 } 92 if (len > 0) { 93 memcpy(h->base, buf, len); /* `write' it. */ 94 h->base += len; 95 h->left -= len; 96 } 97 return 0; 98 } 99 100 /* 101 * syslog, vsyslog -- 102 * print message on log file; output is intended for syslogd(8). 103 */ 104 void 105 syslog(int pri, const char *fmt, ...) 106 { 107 va_list ap; 108 109 va_start(ap, fmt); 110 vsyslog(pri, fmt, ap); 111 va_end(ap); 112 } 113 114 void 115 vsyslog(int pri, const char *fmt, va_list ap) 116 { 117 int cnt; 118 char ch, *p; 119 time_t now; 120 int fd, saved_errno; 121 char *stdp, tbuf[2048], fmt_cpy[1024], timbuf[26]; 122 FILE *fp, *fmt_fp; 123 struct bufcookie tbuf_cookie; 124 struct bufcookie fmt_cookie; 125 126 stdp = NULL; 127 128 #define INTERNALLOG LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID 129 /* Check for invalid bits. */ 130 if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) { 131 syslog(INTERNALLOG, 132 "syslog: unknown facility/priority: %x", pri); 133 pri &= LOG_PRIMASK|LOG_FACMASK; 134 } 135 136 /* Check priority against setlogmask values. */ 137 if (!(LOG_MASK(LOG_PRI(pri)) & LogMask)) 138 return; 139 140 saved_errno = errno; 141 142 /* Set default facility if none specified. */ 143 if ((pri & LOG_FACMASK) == 0) 144 pri |= LogFacility; 145 146 /* Create the primary stdio hook */ 147 tbuf_cookie.base = tbuf; 148 tbuf_cookie.left = sizeof(tbuf); 149 fp = fwopen(&tbuf_cookie, writehook); 150 if (fp == NULL) 151 return; 152 153 /* Build the message. */ 154 time(&now); 155 fprintf(fp, "<%d>", pri); 156 fprintf(fp, "%.15s ", ctime_r(&now, timbuf) + 4); 157 if (LogStat & LOG_PERROR) { 158 /* Transfer to string buffer */ 159 fflush(fp); 160 stdp = tbuf + (sizeof(tbuf) - tbuf_cookie.left); 161 } 162 if (LogTag == NULL) 163 LogTag = getprogname(); 164 if (LogTag != NULL) 165 fprintf(fp, "%s", LogTag); 166 if (LogStat & LOG_PID) 167 fprintf(fp, "[%d]", getpid()); 168 if (LogTag != NULL) { 169 fprintf(fp, ": "); 170 } 171 172 /* Check to see if we can skip expanding the %m */ 173 if (strstr(fmt, "%m")) { 174 175 /* Create the second stdio hook */ 176 fmt_cookie.base = fmt_cpy; 177 fmt_cookie.left = sizeof(fmt_cpy) - 1; 178 fmt_fp = fwopen(&fmt_cookie, writehook); 179 if (fmt_fp == NULL) { 180 fclose(fp); 181 return; 182 } 183 184 /* Substitute error message for %m. */ 185 for ( ; (ch = *fmt); ++fmt) 186 if (ch == '%' && fmt[1] == 'm') { 187 ++fmt; 188 fputs(strerror(saved_errno), fmt_fp); 189 } else 190 fputc(ch, fmt_fp); 191 192 /* Null terminate if room */ 193 fputc(0, fmt_fp); 194 fclose(fmt_fp); 195 196 /* Guarantee null termination */ 197 fmt_cpy[sizeof(fmt_cpy) - 1] = '\0'; 198 199 fmt = fmt_cpy; 200 } 201 202 vfprintf(fp, fmt, ap); 203 fclose(fp); 204 205 cnt = sizeof(tbuf) - tbuf_cookie.left; 206 207 /* Output to stderr if requested. */ 208 if (LogStat & LOG_PERROR) { 209 struct iovec iov[2]; 210 struct iovec *v = iov; 211 212 v->iov_base = stdp; 213 v->iov_len = cnt - (stdp - tbuf); 214 ++v; 215 v->iov_base = "\n"; 216 v->iov_len = 1; 217 _writev(STDERR_FILENO, iov, 2); 218 } 219 220 /* Get connected, output the message to the local logger. */ 221 if (!opened) 222 openlog(LogTag, LogStat | LOG_NDELAY, 0); 223 connectlog(); 224 if (send(LogFile, tbuf, cnt, 0) >= 0) 225 return; 226 227 /* 228 * If the send() failed, the odds are syslogd was restarted. 229 * Make one (only) attempt to reconnect to /dev/log. 230 */ 231 disconnectlog(); 232 connectlog(); 233 if (send(LogFile, tbuf, cnt, 0) >= 0) 234 return; 235 236 /* 237 * Output the message to the console; try not to block 238 * as a blocking console should not stop other processes. 239 * Make sure the error reported is the one from the syslogd failure. 240 */ 241 if (LogStat & LOG_CONS && 242 (fd = _open(_PATH_CONSOLE, O_WRONLY|O_NONBLOCK, 0)) >= 0) { 243 struct iovec iov[2]; 244 struct iovec *v = iov; 245 246 p = strchr(tbuf, '>') + 1; 247 v->iov_base = p; 248 v->iov_len = cnt - (p - tbuf); 249 ++v; 250 v->iov_base = "\r\n"; 251 v->iov_len = 2; 252 _writev(fd, iov, 2); 253 _close(fd); 254 } 255 } 256 static void 257 disconnectlog(void) 258 { 259 /* 260 * If the user closed the FD and opened another in the same slot, 261 * that's their problem. They should close it before calling on 262 * system services. 263 */ 264 if (LogFile != -1) { 265 _close(LogFile); 266 LogFile = -1; 267 } 268 connected = 0; /* retry connect */ 269 } 270 271 static void 272 connectlog(void) 273 { 274 struct sockaddr_un SyslogAddr; /* AF_UNIX address of local logger */ 275 276 if (LogFile == -1) { 277 if ((LogFile = _socket(AF_UNIX, SOCK_DGRAM, 0)) == -1) 278 return; 279 _fcntl(LogFile, F_SETFD, 1); 280 } 281 if (LogFile != -1 && !connected) { 282 SyslogAddr.sun_len = sizeof(SyslogAddr); 283 SyslogAddr.sun_family = AF_UNIX; 284 strncpy(SyslogAddr.sun_path, _PATH_LOG, 285 sizeof SyslogAddr.sun_path); 286 connected = _connect(LogFile, (struct sockaddr *)&SyslogAddr, 287 sizeof(SyslogAddr)) != -1; 288 289 if (!connected) { 290 /* 291 * Try the old "/dev/log" path, for backward 292 * compatibility. 293 */ 294 strncpy(SyslogAddr.sun_path, _PATH_OLDLOG, 295 sizeof SyslogAddr.sun_path); 296 connected = _connect(LogFile, 297 (struct sockaddr *)&SyslogAddr, 298 sizeof(SyslogAddr)) != -1; 299 } 300 301 if (!connected) { 302 _close(LogFile); 303 LogFile = -1; 304 } 305 } 306 } 307 308 void 309 openlog(const char *ident, int logstat, int logfac) 310 { 311 if (ident != NULL) 312 LogTag = ident; 313 LogStat = logstat; 314 if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0) 315 LogFacility = logfac; 316 317 if (LogStat & LOG_NDELAY) /* open immediately */ 318 connectlog(); 319 320 opened = 1; /* ident and facility has been set */ 321 } 322 323 void 324 closelog(void) 325 { 326 _close(LogFile); 327 LogFile = -1; 328 LogTag = NULL; 329 connected = 0; 330 } 331 332 /* setlogmask -- set the log mask level */ 333 int 334 setlogmask(int pmask) 335 { 336 int omask; 337 338 omask = LogMask; 339 if (pmask != 0) 340 LogMask = pmask; 341 return (omask); 342 } 343