crypto/openssh/log.c

   1 /* $OpenBSD: log.c,v 1.50 2017/05/17 01:24:17 djm 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         if (log_change_level(level) != 0) {
 260                 fprintf(stderr, "Unrecognized internal syslog level code %d\n",
 261                     (int) level);
 262                 exit(1);
 263         }
 264
 265         log_handler = NULL;
 266         log_handler_ctx = NULL;
 267
 268         log_on_stderr = on_stderr;
 269         if (on_stderr)
 270                 return;
 271
 272         switch (facility) {
 273         case SYSLOG_FACILITY_DAEMON:
 274                 log_facility = LOG_DAEMON;
 275                 break;
 276         case SYSLOG_FACILITY_USER:
 277                 log_facility = LOG_USER;
 278                 break;
 279         case SYSLOG_FACILITY_AUTH:
 280                 log_facility = LOG_AUTH;
 281                 break;
 282 #ifdef LOG_AUTHPRIV
 283         case SYSLOG_FACILITY_AUTHPRIV:
 284                 log_facility = LOG_AUTHPRIV;
 285                 break;
 286 #endif
 287         case SYSLOG_FACILITY_LOCAL0:
 288                 log_facility = LOG_LOCAL0;
 289                 break;
 290         case SYSLOG_FACILITY_LOCAL1:
 291                 log_facility = LOG_LOCAL1;
 292                 break;
 293         case SYSLOG_FACILITY_LOCAL2:
 294                 log_facility = LOG_LOCAL2;
 295                 break;
 296         case SYSLOG_FACILITY_LOCAL3:
 297                 log_facility = LOG_LOCAL3;
 298                 break;
 299         case SYSLOG_FACILITY_LOCAL4:
 300                 log_facility = LOG_LOCAL4;
 301                 break;
 302         case SYSLOG_FACILITY_LOCAL5:
 303                 log_facility = LOG_LOCAL5;
 304                 break;
 305         case SYSLOG_FACILITY_LOCAL6:
 306                 log_facility = LOG_LOCAL6;
 307                 break;
 308         case SYSLOG_FACILITY_LOCAL7:
 309                 log_facility = LOG_LOCAL7;
 310                 break;
 311         default:
 312                 fprintf(stderr,
 313                     "Unrecognized internal syslog facility code %d\n",
 314                     (int) facility);
 315                 exit(1);
 316         }
 317
 318         /*
 319          * If an external library (eg libwrap) attempts to use syslog
 320          * immediately after reexec, syslog may be pointing to the wrong
 321          * facility, so we force an open/close of syslog here.
 322          */
 323 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
 324         openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
 325         closelog_r(&sdata);
 326 #else
 327         openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
 328         closelog();
 329 #endif
 330 }
 331
 332 int
 333 log_change_level(LogLevel new_log_level)
 334 {
 335         /* no-op if log_init has not been called */
 336         if (argv0 == NULL)
 337                 return 0;
 338
 339         switch (new_log_level) {
 340         case SYSLOG_LEVEL_QUIET:
 341         case SYSLOG_LEVEL_FATAL:
 342         case SYSLOG_LEVEL_ERROR:
 343         case SYSLOG_LEVEL_INFO:
 344         case SYSLOG_LEVEL_VERBOSE:
 345         case SYSLOG_LEVEL_DEBUG1:
 346         case SYSLOG_LEVEL_DEBUG2:
 347         case SYSLOG_LEVEL_DEBUG3:
 348                 log_level = new_log_level;
 349                 return 0;
 350         default:
 351                 return -1;
 352         }
 353 }
 354
 355 int
 356 log_is_on_stderr(void)
 357 {
 358         return log_on_stderr && log_stderr_fd == STDERR_FILENO;
 359 }
 360
 361 /* redirect what would usually get written to stderr to specified file */
 362 void
 363 log_redirect_stderr_to(const char *logfile)
 364 {
 365         int fd;
 366
 367         if ((fd = open(logfile, O_WRONLY|O_CREAT|O_APPEND, 0600)) == -1) {
 368                 fprintf(stderr, "Couldn't open logfile %s: %s\n", logfile,
 369                      strerror(errno));
 370                 exit(1);
 371         }
 372         log_stderr_fd = fd;
 373 }
 374
 375 #define MSGBUFSIZ 1024
 376
 377 void
 378 set_log_handler(log_handler_fn *handler, void *ctx)
 379 {
 380         log_handler = handler;
 381         log_handler_ctx = ctx;
 382 }
 383
 384 void
 385 do_log2(LogLevel level, const char *fmt,...)
 386 {
 387         va_list args;
 388
 389         va_start(args, fmt);
 390         do_log(level, fmt, args);
 391         va_end(args);
 392 }
 393
 394 void
 395 do_log(LogLevel level, const char *fmt, va_list args)
 396 {
 397 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
 398         struct syslog_data sdata = SYSLOG_DATA_INIT;
 399 #endif
 400         char msgbuf[MSGBUFSIZ];
 401         char fmtbuf[MSGBUFSIZ];
 402         char *txt = NULL;
 403         int pri = LOG_INFO;
 404         int saved_errno = errno;
 405         log_handler_fn *tmp_handler;
 406
 407         if (level > log_level)
 408                 return;
 409
 410         switch (level) {
 411         case SYSLOG_LEVEL_FATAL:
 412                 if (!log_on_stderr)
 413                         txt = "fatal";
 414                 pri = LOG_CRIT;
 415                 break;
 416         case SYSLOG_LEVEL_ERROR:
 417                 if (!log_on_stderr)
 418                         txt = "error";
 419                 pri = LOG_ERR;
 420                 break;
 421         case SYSLOG_LEVEL_INFO:
 422                 pri = LOG_INFO;
 423                 break;
 424         case SYSLOG_LEVEL_VERBOSE:
 425                 pri = LOG_INFO;
 426                 break;
 427         case SYSLOG_LEVEL_DEBUG1:
 428                 txt = "debug1";
 429                 pri = LOG_DEBUG;
 430                 break;
 431         case SYSLOG_LEVEL_DEBUG2:
 432                 txt = "debug2";
 433                 pri = LOG_DEBUG;
 434                 break;
 435         case SYSLOG_LEVEL_DEBUG3:
 436                 txt = "debug3";
 437                 pri = LOG_DEBUG;
 438                 break;
 439         default:
 440                 txt = "internal error";
 441                 pri = LOG_ERR;
 442                 break;
 443         }
 444         if (txt != NULL && log_handler == NULL) {
 445                 snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt);
 446                 vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args);
 447         } else {
 448                 vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
 449         }
 450         strnvis(fmtbuf, msgbuf, sizeof(fmtbuf),
 451             log_on_stderr ? LOG_STDERR_VIS : LOG_SYSLOG_VIS);
 452         if (log_handler != NULL) {
 453                 /* Avoid recursion */
 454                 tmp_handler = log_handler;
 455                 log_handler = NULL;
 456                 tmp_handler(level, fmtbuf, log_handler_ctx);
 457                 log_handler = tmp_handler;
 458         } else if (log_on_stderr) {
 459                 snprintf(msgbuf, sizeof msgbuf, "%.*s\r\n",
 460                     (int)sizeof msgbuf - 3, fmtbuf);
 461                 (void)write(log_stderr_fd, msgbuf, strlen(msgbuf));
 462         } else {
 463 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
 464                 openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
 465                 syslog_r(pri, &sdata, "%.500s", fmtbuf);
 466                 closelog_r(&sdata);
 467 #else
 468                 openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
 469                 syslog(pri, "%.500s", fmtbuf);
 470                 closelog();
 471 #endif
 472         }
 473         errno = saved_errno;
 474 }