syslog.c revision 35570
197403Sobrien/* 297403Sobrien * Copyright (c) 1983, 1988, 1993 397403Sobrien * The Regents of the University of California. All rights reserved. 497403Sobrien * 597403Sobrien * Redistribution and use in source and binary forms, with or without 697403Sobrien * modification, are permitted provided that the following conditions 797403Sobrien * are met: 897403Sobrien * 1. Redistributions of source code must retain the above copyright 997403Sobrien * notice, this list of conditions and the following disclaimer. 1097403Sobrien * 2. Redistributions in binary form must reproduce the above copyright 1197403Sobrien * notice, this list of conditions and the following disclaimer in the 1297403Sobrien * documentation and/or other materials provided with the distribution. 1397403Sobrien * 3. All advertising materials mentioning features or use of this software 1497403Sobrien * must display the following acknowledgement: 1597403Sobrien * This product includes software developed by the University of 1697403Sobrien * California, Berkeley and its contributors. 1797403Sobrien * 4. Neither the name of the University nor the names of its contributors 18169691Skan * may be used to endorse or promote products derived from this software 1997403Sobrien * without specific prior written permission. 2097403Sobrien * 2197403Sobrien * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2297403Sobrien * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2397403Sobrien * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2497403Sobrien * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2597403Sobrien * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2697403Sobrien * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2797403Sobrien * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2897403Sobrien * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2997403Sobrien * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3097403Sobrien * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3197403Sobrien * SUCH DAMAGE. 3297403Sobrien */ 3397403Sobrien 3497403Sobrien#if defined(LIBC_SCCS) && !defined(lint) 3597403Sobrien/* 3697403Sobrienstatic char sccsid[] = "@(#)syslog.c 8.5 (Berkeley) 4/29/95"; 3797403Sobrien*/ 3897403Sobrienstatic const char rcsid[] = 3997403Sobrien "$Id: syslog.c,v 1.16 1998/03/06 03:10:49 brian Exp $"; 4097403Sobrien#endif /* LIBC_SCCS and not lint */ 4197403Sobrien 4297403Sobrien#include <sys/types.h> 4397403Sobrien#include <sys/socket.h> 4497403Sobrien#include <sys/syslog.h> 4597403Sobrien#include <sys/uio.h> 4697403Sobrien#include <sys/un.h> 4797403Sobrien#include <netdb.h> 4897403Sobrien 4997403Sobrien#include <errno.h> 50132720Skan#include <fcntl.h> 5197403Sobrien#include <paths.h> 5297403Sobrien#include <stdio.h> 5397403Sobrien#include <string.h> 5497403Sobrien#include <time.h> 55132720Skan#include <unistd.h> 56132720Skan 5797403Sobrien#if __STDC__ 5897403Sobrien#include <stdarg.h> 5997403Sobrien#else 6097403Sobrien#include <varargs.h> 6197403Sobrien#endif 62132720Skan 63132720Skanstatic int LogFile = -1; /* fd for log */ 6497403Sobrienstatic int connected = -1; /* have done connect */ 6597403Sobrienstatic int opened; /* have done openlog() */ 6697403Sobrienstatic int LogStat = 0; /* status bits, set by openlog() */ 6797403Sobrienstatic const char *LogTag = NULL; /* string to tag the entry with */ 6897403Sobrienstatic int LogFacility = LOG_USER; /* default facility code */ 6997403Sobrienstatic int LogMask = 0xff; /* mask of priorities to be logged */ 7097403Sobrienextern char *__progname; /* Program name, from crt0. */ 7197403Sobrien 72132720Skanstatic void disconnectlog __P((void)); /* disconnect from syslogd */ 7397403Sobrienstatic void connectlog __P((void)); /* (re)connect to syslogd */ 7497403Sobrien 7597403Sobrien/* 7697403Sobrien * Format of the magic cookie passed through the stdio hook 7797403Sobrien */ 7897403Sobrienstruct bufcookie { 7997403Sobrien char *base; /* start of buffer */ 8097403Sobrien int left; 8197403Sobrien}; 8297403Sobrien 8397403Sobrien/* 8497403Sobrien * stdio write hook for writing to a static string buffer 8597403Sobrien * XXX: Maybe one day, dynamically allocate it so that the line length 8697403Sobrien * is `unlimited'. 8797403Sobrien */ 8897403Sobrienstatic 8997403Sobrienint writehook(cookie, buf, len) 9097403Sobrien void *cookie; /* really [struct bufcookie *] */ 9197403Sobrien char *buf; /* characters to copy */ 9297403Sobrien int len; /* length to copy */ 9397403Sobrien{ 94132720Skan struct bufcookie *h; /* private `handle' */ 9597403Sobrien 9697403Sobrien h = (struct bufcookie *)cookie; 9797403Sobrien if (len > h->left) { 9897403Sobrien /* clip in case of wraparound */ 99132720Skan len = h->left; 100132720Skan } 10197403Sobrien if (len > 0) { 102132720Skan (void)memcpy(h->base, buf, len); /* `write' it. */ 103132720Skan h->base += len; 10497403Sobrien h->left -= len; 105132720Skan } 106132720Skan return 0; 10797403Sobrien} 10897403Sobrien 10997403Sobrien/* 11097403Sobrien * syslog, vsyslog -- 11197403Sobrien * print message on log file; output is intended for syslogd(8). 11297403Sobrien */ 11397403Sobrienvoid 11497403Sobrien#if __STDC__ 11597403Sobriensyslog(int pri, const char *fmt, ...) 11697403Sobrien#else 117132720Skansyslog(pri, fmt, va_alist) 118 int pri; 119 char *fmt; 120 va_dcl 121#endif 122{ 123 va_list ap; 124 125#if __STDC__ 126 va_start(ap, fmt); 127#else 128 va_start(ap); 129#endif 130 vsyslog(pri, fmt, ap); 131 va_end(ap); 132} 133 134void 135vsyslog(pri, fmt, ap) 136 int pri; 137 register const char *fmt; 138 va_list ap; 139{ 140 register int cnt; 141 register char ch, *p; 142 time_t now; 143 int fd, saved_errno; 144 char *stdp, tbuf[2048], fmt_cpy[1024]; 145 FILE *fp, *fmt_fp; 146 struct bufcookie tbuf_cookie; 147 struct bufcookie fmt_cookie; 148 149#define INTERNALLOG LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID 150 /* Check for invalid bits. */ 151 if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) { 152 syslog(INTERNALLOG, 153 "syslog: unknown facility/priority: %x", pri); 154 pri &= LOG_PRIMASK|LOG_FACMASK; 155 } 156 157 /* Check priority against setlogmask values. */ 158 if (!(LOG_MASK(LOG_PRI(pri)) & LogMask)) 159 return; 160 161 saved_errno = errno; 162 163 /* Set default facility if none specified. */ 164 if ((pri & LOG_FACMASK) == 0) 165 pri |= LogFacility; 166 167 /* Create the primary stdio hook */ 168 tbuf_cookie.base = tbuf; 169 tbuf_cookie.left = sizeof(tbuf); 170 fp = fwopen(&tbuf_cookie, writehook); 171 if (fp == NULL) 172 return; 173 174 /* Build the message. */ 175 (void)time(&now); 176 (void)fprintf(fp, "<%d>", pri); 177 (void)fprintf(fp, "%.15s ", ctime(&now) + 4); 178 if (LogStat & LOG_PERROR) { 179 /* Transfer to string buffer */ 180 (void)fflush(fp); 181 stdp = tbuf + (sizeof(tbuf) - tbuf_cookie.left); 182 } 183 if (LogTag == NULL) 184 LogTag = __progname; 185 if (LogTag != NULL) 186 (void)fprintf(fp, "%s", LogTag); 187 if (LogStat & LOG_PID) 188 (void)fprintf(fp, "[%d]", getpid()); 189 if (LogTag != NULL) { 190 (void)fprintf(fp, ": "); 191 } 192 193 /* Check to see if we can skip expanding the %m */ 194 if (strstr(fmt, "%m")) { 195 196 /* Create the second stdio hook */ 197 fmt_cookie.base = fmt_cpy; 198 fmt_cookie.left = sizeof(fmt_cpy) - 1; 199 fmt_fp = fwopen(&fmt_cookie, writehook); 200 if (fmt_fp == NULL) { 201 fclose(fp); 202 return; 203 } 204 205 /* Substitute error message for %m. */ 206 for ( ; (ch = *fmt); ++fmt) 207 if (ch == '%' && fmt[1] == 'm') { 208 ++fmt; 209 fputs(strerror(saved_errno), fmt_fp); 210 } else 211 fputc(ch, fmt_fp); 212 213 /* Null terminate if room */ 214 fputc(0, fmt_fp); 215 fclose(fmt_fp); 216 217 /* Guarantee null termination */ 218 fmt_cpy[sizeof(fmt_cpy) - 1] = '\0'; 219 220 fmt = fmt_cpy; 221 } 222 223 (void)vfprintf(fp, fmt, ap); 224 (void)fclose(fp); 225 226 cnt = sizeof(tbuf) - tbuf_cookie.left; 227 228 /* Output to stderr if requested. */ 229 if (LogStat & LOG_PERROR) { 230 struct iovec iov[2]; 231 register struct iovec *v = iov; 232 233 v->iov_base = stdp; 234 v->iov_len = cnt - (stdp - tbuf); 235 ++v; 236 v->iov_base = "\n"; 237 v->iov_len = 1; 238 (void)writev(STDERR_FILENO, iov, 2); 239 } 240 241 /* Get connected, output the message to the local logger. */ 242 if (!opened) 243 openlog(LogTag, LogStat | LOG_NDELAY, 0); 244 connectlog(); 245 if (send(LogFile, tbuf, cnt, 0) >= 0) 246 return; 247 248 /* 249 * If the send() failed, the odds are syslogd was restarted. 250 * Make one (only) attempt to reconnect to /dev/log. 251 */ 252 disconnectlog(); 253 connectlog(); 254 if (send(LogFile, tbuf, cnt, 0) >= 0) 255 return; 256 257 /* 258 * Output the message to the console; don't worry about blocking, 259 * if console blocks everything will. Make sure the error reported 260 * is the one from the syslogd failure. 261 */ 262 if (LogStat & LOG_CONS && 263 (fd = open(_PATH_CONSOLE, O_WRONLY, 0)) >= 0) { 264 struct iovec iov[2]; 265 register struct iovec *v = iov; 266 267 p = strchr(tbuf, '>') + 1; 268 v->iov_base = p; 269 v->iov_len = cnt - (p - tbuf); 270 ++v; 271 v->iov_base = "\r\n"; 272 v->iov_len = 2; 273 (void)writev(fd, iov, 2); 274 (void)close(fd); 275 } 276} 277static void 278disconnectlog() 279{ 280 /* 281 * If the user closed the FD and opened another in the same slot, 282 * that's their problem. They should close it before calling on 283 * system services. 284 */ 285 if (LogFile != -1) { 286 close(LogFile); 287 LogFile = -1; 288 } 289 connected = -1; /* retry connect */ 290} 291 292static void 293connectlog() 294{ 295 struct sockaddr_un SyslogAddr; /* AF_UNIX address of local logger */ 296 297 if (LogFile == -1) { 298 if ((LogFile = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1) 299 return; 300 (void)fcntl(LogFile, F_SETFD, 1); 301 } 302 if (LogFile != -1 && connected == -1) { 303 SyslogAddr.sun_len = sizeof(SyslogAddr); 304 SyslogAddr.sun_family = AF_UNIX; 305 (void)strncpy(SyslogAddr.sun_path, _PATH_LOG, 306 sizeof SyslogAddr.sun_path); 307 connected = connect(LogFile, (struct sockaddr *)&SyslogAddr, 308 sizeof(SyslogAddr)) != -1; 309 310 if (connected == -1) { 311 /* 312 * Try the old "/dev/log" path, for backward 313 * compatibility. 314 */ 315 (void)strncpy(SyslogAddr.sun_path, _PATH_OLDLOG, 316 sizeof SyslogAddr.sun_path); 317 connected = connect(LogFile, 318 (struct sockaddr *)&SyslogAddr, 319 sizeof(SyslogAddr)) != -1; 320 } 321 322 if (connected == -1) { 323 (void)close(LogFile); 324 LogFile = -1; 325 } 326 } 327} 328 329void 330openlog(ident, logstat, logfac) 331 const char *ident; 332 int logstat, logfac; 333{ 334 if (ident != NULL) 335 LogTag = ident; 336 LogStat = logstat; 337 if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0) 338 LogFacility = logfac; 339 340 if (LogStat & LOG_NDELAY) /* open immediately */ 341 connectlog(); 342 343 opened = 1; /* ident and facility has been set */ 344} 345 346void 347closelog() 348{ 349 (void)close(LogFile); 350 LogFile = -1; 351 connected = -1; 352} 353 354/* setlogmask -- set the log mask level */ 355int 356setlogmask(pmask) 357 int pmask; 358{ 359 int omask; 360 361 omask = LogMask; 362 if (pmask != 0) 363 LogMask = pmask; 364 return (omask); 365} 366