1 /* $OpenBSD: log.c,v 1.51 2018/07/27 12:03:17 markus 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 LogLevel 109 log_level_get(void) 110 { 111 return log_level; 112 } 113 114 SyslogFacility 115 log_facility_number(char *name) 116 { 117 int i; 118 119 if (name != NULL) 120 for (i = 0; log_facilities[i].name; i++) 121 if (strcasecmp(log_facilities[i].name, name) == 0) 122 return log_facilities[i].val; 123 return SYSLOG_FACILITY_NOT_SET; 124 } 125 126 const char * 127 log_facility_name(SyslogFacility facility) 128 { 129 u_int i; 130 131 for (i = 0; log_facilities[i].name; i++) 132 if (log_facilities[i].val == facility) 133 return log_facilities[i].name; 134 return NULL; 135 } 136 137 LogLevel 138 log_level_number(char *name) 139 { 140 int i; 141 142 if (name != NULL) 143 for (i = 0; log_levels[i].name; i++) 144 if (strcasecmp(log_levels[i].name, name) == 0) 145 return log_levels[i].val; 146 return SYSLOG_LEVEL_NOT_SET; 147 } 148 149 const char * 150 log_level_name(LogLevel level) 151 { 152 u_int i; 153 154 for (i = 0; log_levels[i].name != NULL; i++) 155 if (log_levels[i].val == level) 156 return log_levels[i].name; 157 return NULL; 158 } 159 160 /* Error messages that should be logged. */ 161 162 void 163 error(const char *fmt,...) 164 { 165 va_list args; 166 167 va_start(args, fmt); 168 do_log(SYSLOG_LEVEL_ERROR, fmt, args); 169 va_end(args); 170 } 171 172 void 173 sigdie(const char *fmt,...) 174 { 175 #ifdef DO_LOG_SAFE_IN_SIGHAND 176 va_list args; 177 178 va_start(args, fmt); 179 do_log(SYSLOG_LEVEL_FATAL, fmt, args); 180 va_end(args); 181 #endif 182 _exit(1); 183 } 184 185 void 186 logdie(const char *fmt,...) 187 { 188 va_list args; 189 190 va_start(args, fmt); 191 do_log(SYSLOG_LEVEL_INFO, fmt, args); 192 va_end(args); 193 cleanup_exit(255); 194 } 195 196 /* Log this message (information that usually should go to the log). */ 197 198 void 199 logit(const char *fmt,...) 200 { 201 va_list args; 202 203 va_start(args, fmt); 204 do_log(SYSLOG_LEVEL_INFO, fmt, args); 205 va_end(args); 206 } 207 208 /* More detailed messages (information that does not need to go to the log). */ 209 210 void 211 verbose(const char *fmt,...) 212 { 213 va_list args; 214 215 va_start(args, fmt); 216 do_log(SYSLOG_LEVEL_VERBOSE, fmt, args); 217 va_end(args); 218 } 219 220 /* Debugging messages that should not be logged during normal operation. */ 221 222 void 223 debug(const char *fmt,...) 224 { 225 va_list args; 226 227 va_start(args, fmt); 228 do_log(SYSLOG_LEVEL_DEBUG1, fmt, args); 229 va_end(args); 230 } 231 232 void 233 debug2(const char *fmt,...) 234 { 235 va_list args; 236 237 va_start(args, fmt); 238 do_log(SYSLOG_LEVEL_DEBUG2, fmt, args); 239 va_end(args); 240 } 241 242 void 243 debug3(const char *fmt,...) 244 { 245 va_list args; 246 247 va_start(args, fmt); 248 do_log(SYSLOG_LEVEL_DEBUG3, fmt, args); 249 va_end(args); 250 } 251 252 /* 253 * Initialize the log. 254 */ 255 256 void 257 log_init(char *av0, LogLevel level, SyslogFacility facility, int on_stderr) 258 { 259 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT) 260 struct syslog_data sdata = SYSLOG_DATA_INIT; 261 #endif 262 263 argv0 = av0; 264 265 if (log_change_level(level) != 0) { 266 fprintf(stderr, "Unrecognized internal syslog level code %d\n", 267 (int) level); 268 exit(1); 269 } 270 271 log_handler = NULL; 272 log_handler_ctx = NULL; 273 274 log_on_stderr = on_stderr; 275 if (on_stderr) 276 return; 277 278 switch (facility) { 279 case SYSLOG_FACILITY_DAEMON: 280 log_facility = LOG_DAEMON; 281 break; 282 case SYSLOG_FACILITY_USER: 283 log_facility = LOG_USER; 284 break; 285 case SYSLOG_FACILITY_AUTH: 286 log_facility = LOG_AUTH; 287 break; 288 #ifdef LOG_AUTHPRIV 289 case SYSLOG_FACILITY_AUTHPRIV: 290 log_facility = LOG_AUTHPRIV; 291 break; 292 #endif 293 case SYSLOG_FACILITY_LOCAL0: 294 log_facility = LOG_LOCAL0; 295 break; 296 case SYSLOG_FACILITY_LOCAL1: 297 log_facility = LOG_LOCAL1; 298 break; 299 case SYSLOG_FACILITY_LOCAL2: 300 log_facility = LOG_LOCAL2; 301 break; 302 case SYSLOG_FACILITY_LOCAL3: 303 log_facility = LOG_LOCAL3; 304 break; 305 case SYSLOG_FACILITY_LOCAL4: 306 log_facility = LOG_LOCAL4; 307 break; 308 case SYSLOG_FACILITY_LOCAL5: 309 log_facility = LOG_LOCAL5; 310 break; 311 case SYSLOG_FACILITY_LOCAL6: 312 log_facility = LOG_LOCAL6; 313 break; 314 case SYSLOG_FACILITY_LOCAL7: 315 log_facility = LOG_LOCAL7; 316 break; 317 default: 318 fprintf(stderr, 319 "Unrecognized internal syslog facility code %d\n", 320 (int) facility); 321 exit(1); 322 } 323 324 /* 325 * If an external library (eg libwrap) attempts to use syslog 326 * immediately after reexec, syslog may be pointing to the wrong 327 * facility, so we force an open/close of syslog here. 328 */ 329 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT) 330 openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata); 331 closelog_r(&sdata); 332 #else 333 openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility); 334 closelog(); 335 #endif 336 } 337 338 int 339 log_change_level(LogLevel new_log_level) 340 { 341 /* no-op if log_init has not been called */ 342 if (argv0 == NULL) 343 return 0; 344 345 switch (new_log_level) { 346 case SYSLOG_LEVEL_QUIET: 347 case SYSLOG_LEVEL_FATAL: 348 case SYSLOG_LEVEL_ERROR: 349 case SYSLOG_LEVEL_INFO: 350 case SYSLOG_LEVEL_VERBOSE: 351 case SYSLOG_LEVEL_DEBUG1: 352 case SYSLOG_LEVEL_DEBUG2: 353 case SYSLOG_LEVEL_DEBUG3: 354 log_level = new_log_level; 355 return 0; 356 default: 357 return -1; 358 } 359 } 360 361 int 362 log_is_on_stderr(void) 363 { 364 return log_on_stderr && log_stderr_fd == STDERR_FILENO; 365 } 366 367 /* redirect what would usually get written to stderr to specified file */ 368 void 369 log_redirect_stderr_to(const char *logfile) 370 { 371 int fd; 372 373 if ((fd = open(logfile, O_WRONLY|O_CREAT|O_APPEND, 0600)) == -1) { 374 fprintf(stderr, "Couldn't open logfile %s: %s\n", logfile, 375 strerror(errno)); 376 exit(1); 377 } 378 log_stderr_fd = fd; 379 } 380 381 #define MSGBUFSIZ 1024 382 383 void 384 set_log_handler(log_handler_fn *handler, void *ctx) 385 { 386 log_handler = handler; 387 log_handler_ctx = ctx; 388 } 389 390 void 391 do_log2(LogLevel level, const char *fmt,...) 392 { 393 va_list args; 394 395 va_start(args, fmt); 396 do_log(level, fmt, args); 397 va_end(args); 398 } 399 400 void 401 do_log(LogLevel level, const char *fmt, va_list args) 402 { 403 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT) 404 struct syslog_data sdata = SYSLOG_DATA_INIT; 405 #endif 406 char msgbuf[MSGBUFSIZ]; 407 char fmtbuf[MSGBUFSIZ]; 408 char *txt = NULL; 409 int pri = LOG_INFO; 410 int saved_errno = errno; 411 log_handler_fn *tmp_handler; 412 413 if (level > log_level) 414 return; 415 416 switch (level) { 417 case SYSLOG_LEVEL_FATAL: 418 if (!log_on_stderr) 419 txt = "fatal"; 420 pri = LOG_CRIT; 421 break; 422 case SYSLOG_LEVEL_ERROR: 423 if (!log_on_stderr) 424 txt = "error"; 425 pri = LOG_ERR; 426 break; 427 case SYSLOG_LEVEL_INFO: 428 pri = LOG_INFO; 429 break; 430 case SYSLOG_LEVEL_VERBOSE: 431 pri = LOG_INFO; 432 break; 433 case SYSLOG_LEVEL_DEBUG1: 434 txt = "debug1"; 435 pri = LOG_DEBUG; 436 break; 437 case SYSLOG_LEVEL_DEBUG2: 438 txt = "debug2"; 439 pri = LOG_DEBUG; 440 break; 441 case SYSLOG_LEVEL_DEBUG3: 442 txt = "debug3"; 443 pri = LOG_DEBUG; 444 break; 445 default: 446 txt = "internal error"; 447 pri = LOG_ERR; 448 break; 449 } 450 if (txt != NULL && log_handler == NULL) { 451 snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt); 452 vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args); 453 } else { 454 vsnprintf(msgbuf, sizeof(msgbuf), fmt, args); 455 } 456 strnvis(fmtbuf, msgbuf, sizeof(fmtbuf), 457 log_on_stderr ? LOG_STDERR_VIS : LOG_SYSLOG_VIS); 458 if (log_handler != NULL) { 459 /* Avoid recursion */ 460 tmp_handler = log_handler; 461 log_handler = NULL; 462 tmp_handler(level, fmtbuf, log_handler_ctx); 463 log_handler = tmp_handler; 464 } else if (log_on_stderr) { 465 snprintf(msgbuf, sizeof msgbuf, "%.*s\r\n", 466 (int)sizeof msgbuf - 3, fmtbuf); 467 (void)write(log_stderr_fd, msgbuf, strlen(msgbuf)); 468 } else { 469 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT) 470 openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata); 471 syslog_r(pri, &sdata, "%.500s", fmtbuf); 472 closelog_r(&sdata); 473 #else 474 openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility); 475 syslog(pri, "%.500s", fmtbuf); 476 closelog(); 477 #endif 478 } 479 errno = saved_errno; 480 } 481