1 /* $OpenBSD: log.c,v 1.48 2016/07/15 05:01:58 dtucker Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * 7 * As far as I am concerned, the code I have written for this software 8 * can be used freely for any purpose. Any derived versions of this 9 * software must be clearly marked as such, and if the derived work is 10 * incompatible with the protocol description in the RFC file, it must be 11 * called by a name other than "ssh" or "Secure Shell". 12 */ 13 /* 14 * Copyright (c) 2000 Markus Friedl. All rights reserved. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 26 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 28 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 29 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 30 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 31 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 34 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 35 */ 36 37 #include "includes.h" 38 39 #include <sys/types.h> 40 41 #include <fcntl.h> 42 #include <stdarg.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <syslog.h> 47 #include <unistd.h> 48 #include <errno.h> 49 #if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) && !defined(BROKEN_STRNVIS) 50 # include <vis.h> 51 #endif 52 53 #include "log.h" 54 55 static LogLevel log_level = SYSLOG_LEVEL_INFO; 56 static int log_on_stderr = 1; 57 static int log_stderr_fd = STDERR_FILENO; 58 static int log_facility = LOG_AUTH; 59 static char *argv0; 60 static log_handler_fn *log_handler; 61 static void *log_handler_ctx; 62 63 extern char *__progname; 64 65 #define LOG_SYSLOG_VIS (VIS_CSTYLE|VIS_NL|VIS_TAB|VIS_OCTAL) 66 #define LOG_STDERR_VIS (VIS_SAFE|VIS_OCTAL) 67 68 /* textual representation of log-facilities/levels */ 69 70 static struct { 71 const char *name; 72 SyslogFacility val; 73 } log_facilities[] = { 74 { "DAEMON", SYSLOG_FACILITY_DAEMON }, 75 { "USER", SYSLOG_FACILITY_USER }, 76 { "AUTH", SYSLOG_FACILITY_AUTH }, 77 #ifdef LOG_AUTHPRIV 78 { "AUTHPRIV", SYSLOG_FACILITY_AUTHPRIV }, 79 #endif 80 { "LOCAL0", SYSLOG_FACILITY_LOCAL0 }, 81 { "LOCAL1", SYSLOG_FACILITY_LOCAL1 }, 82 { "LOCAL2", SYSLOG_FACILITY_LOCAL2 }, 83 { "LOCAL3", SYSLOG_FACILITY_LOCAL3 }, 84 { "LOCAL4", SYSLOG_FACILITY_LOCAL4 }, 85 { "LOCAL5", SYSLOG_FACILITY_LOCAL5 }, 86 { "LOCAL6", SYSLOG_FACILITY_LOCAL6 }, 87 { "LOCAL7", SYSLOG_FACILITY_LOCAL7 }, 88 { NULL, SYSLOG_FACILITY_NOT_SET } 89 }; 90 91 static struct { 92 const char *name; 93 LogLevel val; 94 } log_levels[] = 95 { 96 { "QUIET", SYSLOG_LEVEL_QUIET }, 97 { "FATAL", SYSLOG_LEVEL_FATAL }, 98 { "ERROR", SYSLOG_LEVEL_ERROR }, 99 { "INFO", SYSLOG_LEVEL_INFO }, 100 { "VERBOSE", SYSLOG_LEVEL_VERBOSE }, 101 { "DEBUG", SYSLOG_LEVEL_DEBUG1 }, 102 { "DEBUG1", SYSLOG_LEVEL_DEBUG1 }, 103 { "DEBUG2", SYSLOG_LEVEL_DEBUG2 }, 104 { "DEBUG3", SYSLOG_LEVEL_DEBUG3 }, 105 { NULL, SYSLOG_LEVEL_NOT_SET } 106 }; 107 108 SyslogFacility 109 log_facility_number(char *name) 110 { 111 int i; 112 113 if (name != NULL) 114 for (i = 0; log_facilities[i].name; i++) 115 if (strcasecmp(log_facilities[i].name, name) == 0) 116 return log_facilities[i].val; 117 return SYSLOG_FACILITY_NOT_SET; 118 } 119 120 const char * 121 log_facility_name(SyslogFacility facility) 122 { 123 u_int i; 124 125 for (i = 0; log_facilities[i].name; i++) 126 if (log_facilities[i].val == facility) 127 return log_facilities[i].name; 128 return NULL; 129 } 130 131 LogLevel 132 log_level_number(char *name) 133 { 134 int i; 135 136 if (name != NULL) 137 for (i = 0; log_levels[i].name; i++) 138 if (strcasecmp(log_levels[i].name, name) == 0) 139 return log_levels[i].val; 140 return SYSLOG_LEVEL_NOT_SET; 141 } 142 143 const char * 144 log_level_name(LogLevel level) 145 { 146 u_int i; 147 148 for (i = 0; log_levels[i].name != NULL; i++) 149 if (log_levels[i].val == level) 150 return log_levels[i].name; 151 return NULL; 152 } 153 154 /* Error messages that should be logged. */ 155 156 void 157 error(const char *fmt,...) 158 { 159 va_list args; 160 161 va_start(args, fmt); 162 do_log(SYSLOG_LEVEL_ERROR, fmt, args); 163 va_end(args); 164 } 165 166 void 167 sigdie(const char *fmt,...) 168 { 169 #ifdef DO_LOG_SAFE_IN_SIGHAND 170 va_list args; 171 172 va_start(args, fmt); 173 do_log(SYSLOG_LEVEL_FATAL, fmt, args); 174 va_end(args); 175 #endif 176 _exit(1); 177 } 178 179 void 180 logdie(const char *fmt,...) 181 { 182 va_list args; 183 184 va_start(args, fmt); 185 do_log(SYSLOG_LEVEL_INFO, fmt, args); 186 va_end(args); 187 cleanup_exit(255); 188 } 189 190 /* Log this message (information that usually should go to the log). */ 191 192 void 193 logit(const char *fmt,...) 194 { 195 va_list args; 196 197 va_start(args, fmt); 198 do_log(SYSLOG_LEVEL_INFO, fmt, args); 199 va_end(args); 200 } 201 202 /* More detailed messages (information that does not need to go to the log). */ 203 204 void 205 verbose(const char *fmt,...) 206 { 207 va_list args; 208 209 va_start(args, fmt); 210 do_log(SYSLOG_LEVEL_VERBOSE, fmt, args); 211 va_end(args); 212 } 213 214 /* Debugging messages that should not be logged during normal operation. */ 215 216 void 217 debug(const char *fmt,...) 218 { 219 va_list args; 220 221 va_start(args, fmt); 222 do_log(SYSLOG_LEVEL_DEBUG1, fmt, args); 223 va_end(args); 224 } 225 226 void 227 debug2(const char *fmt,...) 228 { 229 va_list args; 230 231 va_start(args, fmt); 232 do_log(SYSLOG_LEVEL_DEBUG2, fmt, args); 233 va_end(args); 234 } 235 236 void 237 debug3(const char *fmt,...) 238 { 239 va_list args; 240 241 va_start(args, fmt); 242 do_log(SYSLOG_LEVEL_DEBUG3, fmt, args); 243 va_end(args); 244 } 245 246 /* 247 * Initialize the log. 248 */ 249 250 void 251 log_init(char *av0, LogLevel level, SyslogFacility facility, int on_stderr) 252 { 253 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT) 254 struct syslog_data sdata = SYSLOG_DATA_INIT; 255 #endif 256 257 argv0 = av0; 258 259 switch (level) { 260 case SYSLOG_LEVEL_QUIET: 261 case SYSLOG_LEVEL_FATAL: 262 case SYSLOG_LEVEL_ERROR: 263 case SYSLOG_LEVEL_INFO: 264 case SYSLOG_LEVEL_VERBOSE: 265 case SYSLOG_LEVEL_DEBUG1: 266 case SYSLOG_LEVEL_DEBUG2: 267 case SYSLOG_LEVEL_DEBUG3: 268 log_level = level; 269 break; 270 default: 271 fprintf(stderr, "Unrecognized internal syslog level code %d\n", 272 (int) level); 273 exit(1); 274 } 275 276 log_handler = NULL; 277 log_handler_ctx = NULL; 278 279 log_on_stderr = on_stderr; 280 if (on_stderr) 281 return; 282 283 switch (facility) { 284 case SYSLOG_FACILITY_DAEMON: 285 log_facility = LOG_DAEMON; 286 break; 287 case SYSLOG_FACILITY_USER: 288 log_facility = LOG_USER; 289 break; 290 case SYSLOG_FACILITY_AUTH: 291 log_facility = LOG_AUTH; 292 break; 293 #ifdef LOG_AUTHPRIV 294 case SYSLOG_FACILITY_AUTHPRIV: 295 log_facility = LOG_AUTHPRIV; 296 break; 297 #endif 298 case SYSLOG_FACILITY_LOCAL0: 299 log_facility = LOG_LOCAL0; 300 break; 301 case SYSLOG_FACILITY_LOCAL1: 302 log_facility = LOG_LOCAL1; 303 break; 304 case SYSLOG_FACILITY_LOCAL2: 305 log_facility = LOG_LOCAL2; 306 break; 307 case SYSLOG_FACILITY_LOCAL3: 308 log_facility = LOG_LOCAL3; 309 break; 310 case SYSLOG_FACILITY_LOCAL4: 311 log_facility = LOG_LOCAL4; 312 break; 313 case SYSLOG_FACILITY_LOCAL5: 314 log_facility = LOG_LOCAL5; 315 break; 316 case SYSLOG_FACILITY_LOCAL6: 317 log_facility = LOG_LOCAL6; 318 break; 319 case SYSLOG_FACILITY_LOCAL7: 320 log_facility = LOG_LOCAL7; 321 break; 322 default: 323 fprintf(stderr, 324 "Unrecognized internal syslog facility code %d\n", 325 (int) facility); 326 exit(1); 327 } 328 329 /* 330 * If an external library (eg libwrap) attempts to use syslog 331 * immediately after reexec, syslog may be pointing to the wrong 332 * facility, so we force an open/close of syslog here. 333 */ 334 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT) 335 openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata); 336 closelog_r(&sdata); 337 #else 338 openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility); 339 closelog(); 340 #endif 341 } 342 343 void 344 log_change_level(LogLevel new_log_level) 345 { 346 /* no-op if log_init has not been called */ 347 if (argv0 == NULL) 348 return; 349 log_init(argv0, new_log_level, log_facility, log_on_stderr); 350 } 351 352 int 353 log_is_on_stderr(void) 354 { 355 return log_on_stderr && log_stderr_fd == STDERR_FILENO; 356 } 357 358 /* redirect what would usually get written to stderr to specified file */ 359 void 360 log_redirect_stderr_to(const char *logfile) 361 { 362 int fd; 363 364 if ((fd = open(logfile, O_WRONLY|O_CREAT|O_APPEND, 0600)) == -1) { 365 fprintf(stderr, "Couldn't open logfile %s: %s\n", logfile, 366 strerror(errno)); 367 exit(1); 368 } 369 log_stderr_fd = fd; 370 } 371 372 #define MSGBUFSIZ 1024 373 374 void 375 set_log_handler(log_handler_fn *handler, void *ctx) 376 { 377 log_handler = handler; 378 log_handler_ctx = ctx; 379 } 380 381 void 382 do_log2(LogLevel level, const char *fmt,...) 383 { 384 va_list args; 385 386 va_start(args, fmt); 387 do_log(level, fmt, args); 388 va_end(args); 389 } 390 391 void 392 do_log(LogLevel level, const char *fmt, va_list args) 393 { 394 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT) 395 struct syslog_data sdata = SYSLOG_DATA_INIT; 396 #endif 397 char msgbuf[MSGBUFSIZ]; 398 char fmtbuf[MSGBUFSIZ]; 399 char *txt = NULL; 400 int pri = LOG_INFO; 401 int saved_errno = errno; 402 log_handler_fn *tmp_handler; 403 404 if (level > log_level) 405 return; 406 407 switch (level) { 408 case SYSLOG_LEVEL_FATAL: 409 if (!log_on_stderr) 410 txt = "fatal"; 411 pri = LOG_CRIT; 412 break; 413 case SYSLOG_LEVEL_ERROR: 414 if (!log_on_stderr) 415 txt = "error"; 416 pri = LOG_ERR; 417 break; 418 case SYSLOG_LEVEL_INFO: 419 pri = LOG_INFO; 420 break; 421 case SYSLOG_LEVEL_VERBOSE: 422 pri = LOG_INFO; 423 break; 424 case SYSLOG_LEVEL_DEBUG1: 425 txt = "debug1"; 426 pri = LOG_DEBUG; 427 break; 428 case SYSLOG_LEVEL_DEBUG2: 429 txt = "debug2"; 430 pri = LOG_DEBUG; 431 break; 432 case SYSLOG_LEVEL_DEBUG3: 433 txt = "debug3"; 434 pri = LOG_DEBUG; 435 break; 436 default: 437 txt = "internal error"; 438 pri = LOG_ERR; 439 break; 440 } 441 if (txt != NULL && log_handler == NULL) { 442 snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt); 443 vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args); 444 } else { 445 vsnprintf(msgbuf, sizeof(msgbuf), fmt, args); 446 } 447 strnvis(fmtbuf, msgbuf, sizeof(fmtbuf), 448 log_on_stderr ? LOG_STDERR_VIS : LOG_SYSLOG_VIS); 449 if (log_handler != NULL) { 450 /* Avoid recursion */ 451 tmp_handler = log_handler; 452 log_handler = NULL; 453 tmp_handler(level, fmtbuf, log_handler_ctx); 454 log_handler = tmp_handler; 455 } else if (log_on_stderr) { 456 snprintf(msgbuf, sizeof msgbuf, "%s\r\n", fmtbuf); 457 (void)write(log_stderr_fd, msgbuf, strlen(msgbuf)); 458 } else { 459 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT) 460 openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata); 461 syslog_r(pri, &sdata, "%.500s", fmtbuf); 462 closelog_r(&sdata); 463 #else 464 openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility); 465 syslog(pri, "%.500s", fmtbuf); 466 closelog(); 467 #endif 468 } 469 errno = saved_errno; 470 } 471