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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #if defined(LIBC_SCCS) && !defined(lint) 31 static char rcsid[] = "$OpenBSD: syslog.c,v 1.26 2004/05/18 02:05:52 jfb Exp $"; 32 #endif /* LIBC_SCCS and not lint */ 33 34 #include <sys/types.h> 35 #include <sys/socket.h> 36 #include <sys/syslog.h> 37 #include <sys/uio.h> 38 #include <sys/un.h> 39 #include <netdb.h> 40 41 #include <errno.h> 42 #include <fcntl.h> 43 #include <paths.h> 44 #include <stdio.h> 45 #include <string.h> 46 #include <time.h> 47 #include <unistd.h> 48 #include <stdarg.h> 49 50 static struct syslog_data sdata = SYSLOG_DATA_INIT; 51 52 extern char *__progname; /* Program name, from crt0. */ 53 54 static void disconnectlog_r(struct syslog_data *); /* disconnect from syslogd */ 55 static void connectlog_r(struct syslog_data *); /* (re)connect to syslogd */ 56 57 /* 58 * syslog, vsyslog -- 59 * print message on log file; output is intended for syslogd(8). 60 */ 61 void 62 syslog(int pri, const char *fmt, ...) 63 { 64 va_list ap; 65 66 va_start(ap, fmt); 67 vsyslog(pri, fmt, ap); 68 va_end(ap); 69 } 70 71 void 72 vsyslog(int pri, const char *fmt, va_list ap) 73 { 74 vsyslog_r(pri, &sdata, fmt, ap); 75 } 76 77 void 78 openlog(const char *ident, int logstat, int logfac) 79 { 80 openlog_r(ident, logstat, logfac, &sdata); 81 } 82 83 void 84 closelog(void) 85 { 86 closelog_r(&sdata); 87 } 88 89 /* setlogmask -- set the log mask level */ 90 int 91 setlogmask(int pmask) 92 { 93 return setlogmask_r(pmask, &sdata); 94 } 95 96 /* Reentrant version of syslog, i.e. syslog_r() */ 97 98 void 99 syslog_r(int pri, struct syslog_data *data, const char *fmt, ...) 100 { 101 va_list ap; 102 103 va_start(ap, fmt); 104 vsyslog_r(pri, data, fmt, ap); 105 va_end(ap); 106 } 107 108 void 109 vsyslog_r(int pri, struct syslog_data *data, const char *fmt, va_list ap) 110 { 111 int cnt; 112 char ch, *p, *t; 113 time_t now; 114 int fd, saved_errno, error; 115 #define TBUF_LEN 2048 116 #define FMT_LEN 1024 117 char *stdp, tbuf[TBUF_LEN], fmt_cpy[FMT_LEN]; 118 int tbuf_left, fmt_left, prlen; 119 120 #define INTERNALLOG LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID 121 /* Check for invalid bits. */ 122 if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) { 123 if (data == &sdata) { 124 syslog(INTERNALLOG, 125 "syslog: unknown facility/priority: %x", pri); 126 } else { 127 syslog_r(INTERNALLOG, data, 128 "syslog_r: unknown facility/priority: %x", pri); 129 } 130 pri &= LOG_PRIMASK|LOG_FACMASK; 131 } 132 133 /* Check priority against setlogmask values. */ 134 if (!(LOG_MASK(LOG_PRI(pri)) & data->log_mask)) 135 return; 136 137 saved_errno = errno; 138 139 /* Set default facility if none specified. */ 140 if ((pri & LOG_FACMASK) == 0) 141 pri |= data->log_fac; 142 143 /* If we have been called through syslog(), no need for reentrancy. */ 144 if (data == &sdata) 145 (void)time(&now); 146 147 p = tbuf; 148 tbuf_left = TBUF_LEN; 149 150 #define DEC() \ 151 do { \ 152 if (prlen < 0) \ 153 prlen = 0; \ 154 if (prlen >= tbuf_left) \ 155 prlen = tbuf_left - 1; \ 156 p += prlen; \ 157 tbuf_left -= prlen; \ 158 } while (0) 159 160 prlen = snprintf(p, tbuf_left, "<%d>", pri); 161 DEC(); 162 163 /* 164 * syslogd will expand time automagically for reentrant case, and 165 * for normal case, just do like before 166 */ 167 if (data == &sdata) { 168 prlen = strftime(p, tbuf_left, "%h %e %T ", localtime(&now)); 169 DEC(); 170 } 171 172 if (data->log_stat & LOG_PERROR) 173 stdp = p; 174 if (data->log_tag == NULL) 175 data->log_tag = __progname; 176 if (data->log_tag != NULL) { 177 prlen = snprintf(p, tbuf_left, "%s", data->log_tag); 178 DEC(); 179 } 180 if (data->log_stat & LOG_PID) { 181 prlen = snprintf(p, tbuf_left, "[%ld]", (long)getpid()); 182 DEC(); 183 } 184 if (data->log_tag != NULL) { 185 if (tbuf_left > 1) { 186 *p++ = ':'; 187 tbuf_left--; 188 } 189 if (tbuf_left > 1) { 190 *p++ = ' '; 191 tbuf_left--; 192 } 193 } 194 195 /* strerror() is not reentrant */ 196 197 for (t = fmt_cpy, fmt_left = FMT_LEN; (ch = *fmt); ++fmt) { 198 if (ch == '%' && fmt[1] == 'm') { 199 ++fmt; 200 if (data == &sdata) { 201 prlen = snprintf(t, fmt_left, "%s", 202 strerror(saved_errno)); 203 } else { 204 prlen = snprintf(t, fmt_left, "Error %d", 205 saved_errno); 206 } 207 if (prlen >= fmt_left) 208 prlen = fmt_left - 1; 209 t += prlen; 210 fmt_left -= prlen; 211 } else if (ch == '%' && fmt[1] == '%' && fmt_left > 2) { 212 *t++ = '%'; 213 *t++ = '%'; 214 fmt++; 215 fmt_left -= 2; 216 } else { 217 if (fmt_left > 1) { 218 *t++ = ch; 219 fmt_left--; 220 } 221 } 222 } 223 *t = '\0'; 224 225 prlen = vsnprintf(p, tbuf_left, fmt_cpy, ap); 226 DEC(); 227 cnt = p - tbuf; 228 229 /* Output to stderr if requested. */ 230 if (data->log_stat & LOG_PERROR) { 231 struct iovec iov[2]; 232 233 iov[0].iov_base = stdp; 234 iov[0].iov_len = cnt - (stdp - tbuf); 235 iov[1].iov_base = "\n"; 236 iov[1].iov_len = 1; 237 (void)writev(STDERR_FILENO, iov, 2); 238 } 239 240 /* Get connected, output the message to the local logger. */ 241 if (!data->opened) 242 openlog_r(data->log_tag, data->log_stat, 0, data); 243 connectlog_r(data); 244 245 /* 246 * If the send() failed, there are two likely scenarios: 247 * 1) syslogd was restarted 248 * 2) /dev/log is out of socket buffer space 249 * We attempt to reconnect to /dev/log to take care of 250 * case #1 and keep send()ing data to cover case #2 251 * to give syslogd a chance to empty its socket buffer. 252 */ 253 if ((error = send(data->log_file, tbuf, cnt, 0)) < 0) { 254 if (errno != ENOBUFS) { 255 disconnectlog_r(data); 256 connectlog_r(data); 257 } 258 do { 259 usleep(1); 260 if ((error = send(data->log_file, tbuf, cnt, 0)) >= 0) 261 break; 262 } while (errno == ENOBUFS); 263 } 264 265 /* 266 * Output the message to the console; try not to block 267 * as a blocking console should not stop other processes. 268 * Make sure the error reported is the one from the syslogd failure. 269 */ 270 if (error == -1 && (data->log_stat & LOG_CONS) && 271 (fd = open(_PATH_CONSOLE, O_WRONLY|O_NONBLOCK, 0)) >= 0) { 272 struct iovec iov[2]; 273 274 p = strchr(tbuf, '>') + 1; 275 iov[0].iov_base = p; 276 iov[0].iov_len = cnt - (p - tbuf); 277 iov[1].iov_base = "\r\n"; 278 iov[1].iov_len = 2; 279 (void)writev(fd, iov, 2); 280 (void)close(fd); 281 } 282 283 if (data != &sdata) 284 closelog_r(data); 285 } 286 287 static void 288 disconnectlog_r(struct syslog_data *data) 289 { 290 /* 291 * If the user closed the FD and opened another in the same slot, 292 * that's their problem. They should close it before calling on 293 * system services. 294 */ 295 if (data->log_file != -1) { 296 close(data->log_file); 297 data->log_file = -1; 298 } 299 data->connected = 0; /* retry connect */ 300 } 301 302 static void 303 connectlog_r(struct syslog_data *data) 304 { 305 struct sockaddr_un SyslogAddr; /* AF_UNIX address of local logger */ 306 307 if (data->log_file == -1) { 308 if ((data->log_file = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1) 309 return; 310 (void)fcntl(data->log_file, F_SETFD, 1); 311 } 312 if (data->log_file != -1 && !data->connected) { 313 memset(&SyslogAddr, '\0', sizeof(SyslogAddr)); 314 SyslogAddr.sun_len = sizeof(SyslogAddr); 315 SyslogAddr.sun_family = AF_UNIX; 316 strlcpy(SyslogAddr.sun_path, _PATH_LOG, 317 sizeof(SyslogAddr.sun_path)); 318 if (connect(data->log_file, (struct sockaddr *)&SyslogAddr, 319 sizeof(SyslogAddr)) == -1) { 320 (void)close(data->log_file); 321 data->log_file = -1; 322 } else 323 data->connected = 1; 324 } 325 } 326 327 void 328 openlog_r(const char *ident, int logstat, int logfac, struct syslog_data *data) 329 { 330 if (ident != NULL) 331 data->log_tag = ident; 332 data->log_stat = logstat; 333 if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0) 334 data->log_fac = logfac; 335 336 if (data->log_stat & LOG_NDELAY) /* open immediately */ 337 connectlog_r(data); 338 339 data->opened = 1; /* ident and facility has been set */ 340 } 341 342 void 343 closelog_r(struct syslog_data *data) 344 { 345 (void)close(data->log_file); 346 data->log_file = -1; 347 data->connected = 0; 348 data->log_tag = NULL; 349 } 350 351 /* setlogmask -- set the log mask level */ 352 int 353 setlogmask_r(int pmask, struct syslog_data *data) 354 { 355 int omask; 356 357 omask = data->log_mask; 358 if (pmask != 0) 359 data->log_mask = pmask; 360 return (omask); 361 } 362