crypto/openssh/log.c

   1 /* $OpenBSD: log.c,v 1.60 2021/09/16 15:11:19 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 #include "match.h"
  55
  56 static LogLevel log_level = SYSLOG_LEVEL_INFO;
  57 static int log_on_stderr = 1;
  58 static int log_stderr_fd = STDERR_FILENO;
  59 static int log_facility = LOG_AUTH;
  60 static const char *argv0;
  61 static log_handler_fn *log_handler;
  62 static void *log_handler_ctx;
  63 static char **log_verbose;
  64 static size_t nlog_verbose;
  65
  66 extern char *__progname;
  67
  68 #define LOG_SYSLOG_VIS  (VIS_CSTYLE|VIS_NL|VIS_TAB|VIS_OCTAL)
  69 #define LOG_STDERR_VIS  (VIS_SAFE|VIS_OCTAL)
  70
  71 /* textual representation of log-facilities/levels */
  72
  73 static struct {
  74         const char *name;
  75         SyslogFacility val;
  76 } log_facilities[] = {
  77         { "DAEMON",     SYSLOG_FACILITY_DAEMON },
  78         { "USER",       SYSLOG_FACILITY_USER },
  79         { "AUTH",       SYSLOG_FACILITY_AUTH },
  80 #ifdef LOG_AUTHPRIV
  81         { "AUTHPRIV",   SYSLOG_FACILITY_AUTHPRIV },
  82 #endif
  83         { "LOCAL0",     SYSLOG_FACILITY_LOCAL0 },
  84         { "LOCAL1",     SYSLOG_FACILITY_LOCAL1 },
  85         { "LOCAL2",     SYSLOG_FACILITY_LOCAL2 },
  86         { "LOCAL3",     SYSLOG_FACILITY_LOCAL3 },
  87         { "LOCAL4",     SYSLOG_FACILITY_LOCAL4 },
  88         { "LOCAL5",     SYSLOG_FACILITY_LOCAL5 },
  89         { "LOCAL6",     SYSLOG_FACILITY_LOCAL6 },
  90         { "LOCAL7",     SYSLOG_FACILITY_LOCAL7 },
  91         { NULL,         SYSLOG_FACILITY_NOT_SET }
  92 };
  93
  94 static struct {
  95         const char *name;
  96         LogLevel val;
  97 } log_levels[] =
  98 {
  99         { "QUIET",      SYSLOG_LEVEL_QUIET },
 100         { "FATAL",      SYSLOG_LEVEL_FATAL },
 101         { "ERROR",      SYSLOG_LEVEL_ERROR },
 102         { "INFO",       SYSLOG_LEVEL_INFO },
 103         { "VERBOSE",    SYSLOG_LEVEL_VERBOSE },
 104         { "DEBUG",      SYSLOG_LEVEL_DEBUG1 },
 105         { "DEBUG1",     SYSLOG_LEVEL_DEBUG1 },
 106         { "DEBUG2",     SYSLOG_LEVEL_DEBUG2 },
 107         { "DEBUG3",     SYSLOG_LEVEL_DEBUG3 },
 108         { NULL,         SYSLOG_LEVEL_NOT_SET }
 109 };
 110
 111 LogLevel
 112 log_level_get(void)
 113 {
 114         return log_level;
 115 }
 116
 117 SyslogFacility
 118 log_facility_number(char *name)
 119 {
 120         int i;
 121
 122         if (name != NULL)
 123                 for (i = 0; log_facilities[i].name; i++)
 124                         if (strcasecmp(log_facilities[i].name, name) == 0)
 125                                 return log_facilities[i].val;
 126         return SYSLOG_FACILITY_NOT_SET;
 127 }
 128
 129 const char *
 130 log_facility_name(SyslogFacility facility)
 131 {
 132         u_int i;
 133
 134         for (i = 0;  log_facilities[i].name; i++)
 135                 if (log_facilities[i].val == facility)
 136                         return log_facilities[i].name;
 137         return NULL;
 138 }
 139
 140 LogLevel
 141 log_level_number(char *name)
 142 {
 143         int i;
 144
 145         if (name != NULL)
 146                 for (i = 0; log_levels[i].name; i++)
 147                         if (strcasecmp(log_levels[i].name, name) == 0)
 148                                 return log_levels[i].val;
 149         return SYSLOG_LEVEL_NOT_SET;
 150 }
 151
 152 const char *
 153 log_level_name(LogLevel level)
 154 {
 155         u_int i;
 156
 157         for (i = 0; log_levels[i].name != NULL; i++)
 158                 if (log_levels[i].val == level)
 159                         return log_levels[i].name;
 160         return NULL;
 161 }
 162
 163 void
 164 log_verbose_add(const char *s)
 165 {
 166         char **tmp;
 167
 168         /* Ignore failures here */
 169         if ((tmp = recallocarray(log_verbose, nlog_verbose, nlog_verbose + 1,
 170             sizeof(*log_verbose))) != NULL) {
 171                 log_verbose = tmp;
 172                 if ((log_verbose[nlog_verbose] = strdup(s)) != NULL)
 173                         nlog_verbose++;
 174         }
 175 }
 176
 177 void
 178 log_verbose_reset(void)
 179 {
 180         size_t i;
 181
 182         for (i = 0; i < nlog_verbose; i++)
 183                 free(log_verbose[i]);
 184         free(log_verbose);
 185         log_verbose = NULL;
 186         nlog_verbose = 0;
 187 }
 188
 189 /*
 190  * Initialize the log.
 191  */
 192
 193 void
 194 log_init(const char *av0, LogLevel level, SyslogFacility facility,
 195     int on_stderr)
 196 {
 197 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
 198         struct syslog_data sdata = SYSLOG_DATA_INIT;
 199 #endif
 200
 201         argv0 = av0;
 202
 203         if (log_change_level(level) != 0) {
 204                 fprintf(stderr, "Unrecognized internal syslog level code %d\n",
 205                     (int) level);
 206                 exit(1);
 207         }
 208
 209         log_handler = NULL;
 210         log_handler_ctx = NULL;
 211
 212         log_on_stderr = on_stderr;
 213         if (on_stderr)
 214                 return;
 215
 216         switch (facility) {
 217         case SYSLOG_FACILITY_DAEMON:
 218                 log_facility = LOG_DAEMON;
 219                 break;
 220         case SYSLOG_FACILITY_USER:
 221                 log_facility = LOG_USER;
 222                 break;
 223         case SYSLOG_FACILITY_AUTH:
 224                 log_facility = LOG_AUTH;
 225                 break;
 226 #ifdef LOG_AUTHPRIV
 227         case SYSLOG_FACILITY_AUTHPRIV:
 228                 log_facility = LOG_AUTHPRIV;
 229                 break;
 230 #endif
 231         case SYSLOG_FACILITY_LOCAL0:
 232                 log_facility = LOG_LOCAL0;
 233                 break;
 234         case SYSLOG_FACILITY_LOCAL1:
 235                 log_facility = LOG_LOCAL1;
 236                 break;
 237         case SYSLOG_FACILITY_LOCAL2:
 238                 log_facility = LOG_LOCAL2;
 239                 break;
 240         case SYSLOG_FACILITY_LOCAL3:
 241                 log_facility = LOG_LOCAL3;
 242                 break;
 243         case SYSLOG_FACILITY_LOCAL4:
 244                 log_facility = LOG_LOCAL4;
 245                 break;
 246         case SYSLOG_FACILITY_LOCAL5:
 247                 log_facility = LOG_LOCAL5;
 248                 break;
 249         case SYSLOG_FACILITY_LOCAL6:
 250                 log_facility = LOG_LOCAL6;
 251                 break;
 252         case SYSLOG_FACILITY_LOCAL7:
 253                 log_facility = LOG_LOCAL7;
 254                 break;
 255         default:
 256                 fprintf(stderr,
 257                     "Unrecognized internal syslog facility code %d\n",
 258                     (int) facility);
 259                 exit(1);
 260         }
 261
 262         /*
 263          * If an external library (eg libwrap) attempts to use syslog
 264          * immediately after reexec, syslog may be pointing to the wrong
 265          * facility, so we force an open/close of syslog here.
 266          */
 267 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
 268         openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
 269         closelog_r(&sdata);
 270 #else
 271         openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
 272         closelog();
 273 #endif
 274 }
 275
 276 int
 277 log_change_level(LogLevel new_log_level)
 278 {
 279         /* no-op if log_init has not been called */
 280         if (argv0 == NULL)
 281                 return 0;
 282
 283         switch (new_log_level) {
 284         case SYSLOG_LEVEL_QUIET:
 285         case SYSLOG_LEVEL_FATAL:
 286         case SYSLOG_LEVEL_ERROR:
 287         case SYSLOG_LEVEL_INFO:
 288         case SYSLOG_LEVEL_VERBOSE:
 289         case SYSLOG_LEVEL_DEBUG1:
 290         case SYSLOG_LEVEL_DEBUG2:
 291         case SYSLOG_LEVEL_DEBUG3:
 292                 log_level = new_log_level;
 293                 return 0;
 294         default:
 295                 return -1;
 296         }
 297 }
 298
 299 int
 300 log_is_on_stderr(void)
 301 {
 302         return log_on_stderr && log_stderr_fd == STDERR_FILENO;
 303 }
 304
 305 /* redirect what would usually get written to stderr to specified file */
 306 void
 307 log_redirect_stderr_to(const char *logfile)
 308 {
 309         int fd;
 310
 311         if (logfile == NULL) {
 312                 if (log_stderr_fd != STDERR_FILENO) {
 313                         close(log_stderr_fd);
 314                         log_stderr_fd = STDERR_FILENO;
 315                 }
 316                 return;
 317         }
 318
 319         if ((fd = open(logfile, O_WRONLY|O_CREAT|O_APPEND, 0600)) == -1) {
 320                 fprintf(stderr, "Couldn't open logfile %s: %s\n", logfile,
 321                     strerror(errno));
 322                 exit(1);
 323         }
 324         log_stderr_fd = fd;
 325 }
 326
 327 #define MSGBUFSIZ 1024
 328
 329 void
 330 set_log_handler(log_handler_fn *handler, void *ctx)
 331 {
 332         log_handler = handler;
 333         log_handler_ctx = ctx;
 334 }
 335
 336 static void
 337 do_log(LogLevel level, int force, const char *suffix, const char *fmt,
 338     va_list args)
 339 {
 340 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
 341         struct syslog_data sdata = SYSLOG_DATA_INIT;
 342 #endif
 343         char msgbuf[MSGBUFSIZ];
 344         char fmtbuf[MSGBUFSIZ];
 345         char *txt = NULL;
 346         int pri = LOG_INFO;
 347         int saved_errno = errno;
 348         log_handler_fn *tmp_handler;
 349         const char *progname = argv0 != NULL ? argv0 : __progname;
 350
 351         if (!force && level > log_level)
 352                 return;
 353
 354         switch (level) {
 355         case SYSLOG_LEVEL_FATAL:
 356                 if (!log_on_stderr)
 357                         txt = "fatal";
 358                 pri = LOG_CRIT;
 359                 break;
 360         case SYSLOG_LEVEL_ERROR:
 361                 if (!log_on_stderr)
 362                         txt = "error";
 363                 pri = LOG_ERR;
 364                 break;
 365         case SYSLOG_LEVEL_INFO:
 366                 pri = LOG_INFO;
 367                 break;
 368         case SYSLOG_LEVEL_VERBOSE:
 369                 pri = LOG_INFO;
 370                 break;
 371         case SYSLOG_LEVEL_DEBUG1:
 372                 txt = "debug1";
 373                 pri = LOG_DEBUG;
 374                 break;
 375         case SYSLOG_LEVEL_DEBUG2:
 376                 txt = "debug2";
 377                 pri = LOG_DEBUG;
 378                 break;
 379         case SYSLOG_LEVEL_DEBUG3:
 380                 txt = "debug3";
 381                 pri = LOG_DEBUG;
 382                 break;
 383         default:
 384                 txt = "internal error";
 385                 pri = LOG_ERR;
 386                 break;
 387         }
 388         if (txt != NULL && log_handler == NULL) {
 389                 snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt);
 390                 vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args);
 391         } else {
 392                 vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
 393         }
 394         if (suffix != NULL) {
 395                 snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", msgbuf, suffix);
 396                 strlcpy(msgbuf, fmtbuf, sizeof(msgbuf));
 397         }
 398         strnvis(fmtbuf, msgbuf, sizeof(fmtbuf),
 399             log_on_stderr ? LOG_STDERR_VIS : LOG_SYSLOG_VIS);
 400         if (log_handler != NULL) {
 401                 /* Avoid recursion */
 402                 tmp_handler = log_handler;
 403                 log_handler = NULL;
 404                 tmp_handler(level, force, fmtbuf, log_handler_ctx);
 405                 log_handler = tmp_handler;
 406         } else if (log_on_stderr) {
 407                 snprintf(msgbuf, sizeof msgbuf, "%s%s%.*s\r\n",
 408                     (log_on_stderr > 1) ? progname : "",
 409                     (log_on_stderr > 1) ? ": " : "",
 410                     (int)sizeof msgbuf - 3, fmtbuf);
 411                 (void)write(log_stderr_fd, msgbuf, strlen(msgbuf));
 412         } else {
 413 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
 414                 openlog_r(progname, LOG_PID, log_facility, &sdata);
 415                 syslog_r(pri, &sdata, "%.500s", fmtbuf);
 416                 closelog_r(&sdata);
 417 #else
 418                 openlog(progname, LOG_PID, log_facility);
 419                 syslog(pri, "%.500s", fmtbuf);
 420                 closelog();
 421 #endif
 422         }
 423         errno = saved_errno;
 424 }
 425
 426 void
 427 sshlog(const char *file, const char *func, int line, int showfunc,
 428     LogLevel level, const char *suffix, const char *fmt, ...)
 429 {
 430         va_list args;
 431
 432         va_start(args, fmt);
 433         sshlogv(file, func, line, showfunc, level, suffix, fmt, args);
 434         va_end(args);
 435 }
 436
 437 void
 438 sshlogdie(const char *file, const char *func, int line, int showfunc,
 439     LogLevel level, const char *suffix, const char *fmt, ...)
 440 {
 441         va_list args;
 442
 443         va_start(args, fmt);
 444         sshlogv(file, func, line, showfunc, SYSLOG_LEVEL_INFO,
 445             suffix, fmt, args);
 446         va_end(args);
 447         cleanup_exit(255);
 448 }
 449
 450 void
 451 sshsigdie(const char *file, const char *func, int line, int showfunc,
 452     LogLevel level, const char *suffix, const char *fmt, ...)
 453 {
 454         va_list args;
 455
 456         va_start(args, fmt);
 457         sshlogv(file, func, line, showfunc, SYSLOG_LEVEL_FATAL,
 458             suffix, fmt, args);
 459         va_end(args);
 460         _exit(1);
 461 }
 462
 463 void
 464 sshlogv(const char *file, const char *func, int line, int showfunc,
 465     LogLevel level, const char *suffix, const char *fmt, va_list args)
 466 {
 467         char tag[128], fmt2[MSGBUFSIZ + 128];
 468         int forced = 0;
 469         const char *cp;
 470         size_t i;
 471
 472         snprintf(tag, sizeof(tag), "%.48s:%.48s():%d (pid=%ld)",
 473             (cp = strrchr(file, '/')) == NULL ? file : cp + 1, func, line,
 474             (long)getpid());
 475         for (i = 0; i < nlog_verbose; i++) {
 476                 if (match_pattern_list(tag, log_verbose[i], 0) == 1) {
 477                         forced = 1;
 478                         break;
 479                 }
 480         }
 481
 482         if (forced)
 483                 snprintf(fmt2, sizeof(fmt2), "%s: %s", tag, fmt);
 484         else if (showfunc)
 485                 snprintf(fmt2, sizeof(fmt2), "%s: %s", func, fmt);
 486         else
 487                 strlcpy(fmt2, fmt, sizeof(fmt2));
 488
 489         do_log(level, forced, suffix, fmt2, args);
 490 }
 491
 492 void
 493 sshlogdirect(LogLevel level, int forced, const char *fmt, ...)
 494 {
 495         va_list args;
 496
 497         va_start(args, fmt);
 498         do_log(level, forced, NULL, fmt, args);
 499         va_end(args);
 500 }