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 /* Substitute error message for %m. */ 193 for ( ; (ch = *fmt); ++fmt) 194 if (ch == '%' && fmt[1] == 'm') { 195 ++fmt; 196 fputs(strerror(saved_errno), fmt_fp); 197 } else 198 fputc(ch, fmt_fp); 199 200 /* Null terminate if room */ 201 fputc(0, fmt_fp); 202 fclose(fmt_fp); 203 204 /* Guarantee null termination */ 205 fmt_cpy[sizeof(fmt_cpy) - 1] = '\0'; 206 207 fmt = fmt_cpy; 208 } 209 210 (void)vfprintf(fp, fmt, ap); 211 (void)fclose(fp); 212 213 cnt = sizeof(tbuf) - tbuf_cookie.left; 214 215 /* Output to stderr if requested. */ 216 if (LogStat & LOG_PERROR) { 217 struct iovec iov[2]; 218 struct iovec *v = iov; 219 220 v->iov_base = stdp; 221 v->iov_len = cnt - (stdp - tbuf); 222 ++v; 223 v->iov_base = "\n"; 224 v->iov_len = 1; 225 (void)_writev(STDERR_FILENO, iov, 2); 226 } 227 228 /* Get connected, output the message to the local logger. */ 229 if (!opened) 230 openlog(LogTag, LogStat | LOG_NDELAY, 0); 231 connectlog(); 232 if (send(LogFile, tbuf, cnt, 0) >= 0) 233 return; 234 235 /* 236 * If the send() failed, the odds are syslogd was restarted. 237 * Make one (only) attempt to reconnect to /dev/log. 238 */ 239 disconnectlog(); 240 connectlog(); 241 if (send(LogFile, tbuf, cnt, 0) >= 0) 242 return; 243 244 /* 245 * Output the message to the console; try not to block 246 * as a blocking console should not stop other processes. 247 * Make sure the error reported is the one from the syslogd failure. 248 */ 249 if (LogStat & LOG_CONS && 250 (fd = _open(_PATH_CONSOLE, O_WRONLY|O_NONBLOCK, 0)) >= 0) { 251 struct iovec iov[2]; 252 struct iovec *v = iov; 253 254 p = strchr(tbuf, '>') + 1; 255 v->iov_base = p; 256 v->iov_len = cnt - (p - tbuf); 257 ++v; 258 v->iov_base = "\r\n"; 259 v->iov_len = 2; 260 (void)_writev(fd, iov, 2); 261 (void)_close(fd); 262 } 263 } 264 static void 265 disconnectlog() 266 { 267 /* 268 * If the user closed the FD and opened another in the same slot, 269 * that's their problem. They should close it before calling on 270 * system services. 271 */ 272 if (LogFile != -1) { 273 _close(LogFile); 274 LogFile = -1; 275 } 276 connected = 0; /* retry connect */ 277 } 278 279 static void 280 connectlog() 281 { 282 struct sockaddr_un SyslogAddr; /* AF_UNIX address of local logger */ 283 284 if (LogFile == -1) { 285 if ((LogFile = _socket(AF_UNIX, SOCK_DGRAM, 0)) == -1) 286 return; 287 (void)_fcntl(LogFile, F_SETFD, 1); 288 } 289 if (LogFile != -1 && !connected) { 290 SyslogAddr.sun_len = sizeof(SyslogAddr); 291 SyslogAddr.sun_family = AF_UNIX; 292 (void)strncpy(SyslogAddr.sun_path, _PATH_LOG, 293 sizeof SyslogAddr.sun_path); 294 connected = _connect(LogFile, (struct sockaddr *)&SyslogAddr, 295 sizeof(SyslogAddr)) != -1; 296 297 if (!connected) { 298 /* 299 * Try the old "/dev/log" path, for backward 300 * compatibility. 301 */ 302 (void)strncpy(SyslogAddr.sun_path, _PATH_OLDLOG, 303 sizeof SyslogAddr.sun_path); 304 connected = _connect(LogFile, 305 (struct sockaddr *)&SyslogAddr, 306 sizeof(SyslogAddr)) != -1; 307 } 308 309 if (!connected) { 310 (void)_close(LogFile); 311 LogFile = -1; 312 } 313 } 314 } 315 316 void 317 openlog(ident, logstat, logfac) 318 const char *ident; 319 int logstat, logfac; 320 { 321 if (ident != NULL) 322 LogTag = ident; 323 LogStat = logstat; 324 if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0) 325 LogFacility = logfac; 326 327 if (LogStat & LOG_NDELAY) /* open immediately */ 328 connectlog(); 329 330 opened = 1; /* ident and facility has been set */ 331 } 332 333 void 334 closelog() 335 { 336 (void)_close(LogFile); 337 LogFile = -1; 338 connected = 0; 339 } 340 341 /* setlogmask -- set the log mask level */ 342 int 343 setlogmask(pmask) 344 int pmask; 345 { 346 int omask; 347 348 omask = LogMask; 349 if (pmask != 0) 350 LogMask = pmask; 351 return (omask); 352 } 353