os_win32/syslog_win32.cpp

   1 /*
   2  * os_win32/syslog_win32.cpp
   3  *
   4  * Home page of code is: http://www.smartmontools.org
   5  *
   6  * Copyright (C) 2004-15 Christian Franke
   7  *
   8  * SPDX-License-Identifier: GPL-2.0-or-later
   9  */
  10
  11 // Win32 Emulation of syslog() for smartd
  12 // Writes to windows event log on NT4/2000/XP
  13 // (Register syslogevt.exe as event message file)
  14 // If facility is set to LOG_LOCAL[0-7], log is written to
  15 // file "<ident>.log", stdout, stderr, "<ident>[1-5].log".
  16
  17
  18 #include "syslog.h"
  19
  20 #include <stdlib.h>
  21 #include <stdio.h>
  22 #include <time.h>
  23 #include <errno.h>
  24 #include <process.h> // getpid()
  25
  26 #define WIN32_LEAN_AND_MEAN
  27 #include <windows.h> // RegisterEventSourceA(), ReportEventA(), ...
  28
  29 const char *syslog_win32_cpp_cvsid = "$Id: syslog_win32.cpp 4760 2018-08-19 18:45:53Z chrfranke $"
  30   SYSLOG_H_CVSID;
  31
  32 #ifdef _MSC_VER
  33 // MSVC
  34 #define snprintf _snprintf
  35 #define vsnprintf _vsnprintf
  36 #endif
  37
  38 #define ARGUSED(x) ((void)(x))
  39
  40
  41 #ifndef _MT
  42 //MT runtime not necessary, because thread uses no unsafe lib functions
  43 //#error Program must be linked with multithreaded runtime library
  44 #endif
  45
  46
  47 #ifdef TESTEVT
  48 // Redirect event log to stdout for testing
  49
  50 static BOOL Test_ReportEventA(HANDLE h, WORD type, WORD cat, DWORD id, PSID usid,
  51                                                 WORD nstrings, WORD datasize, LPCTSTR * strings, LPVOID data)
  52 {
  53         int i;
  54         printf("%u %lu:%s", type, id, nstrings != 1?"\n":"");
  55         for (i = 0; i < nstrings; i++)
  56                 printf(" \"%s\"\n", strings[i]);
  57         fflush(stdout);
  58         return TRUE;
  59 }
  60
  61 HANDLE Test_RegisterEventSourceA(LPCTSTR server, LPCTSTR source)
  62 {
  63         return (HANDLE)42;
  64 }
  65
  66 #define ReportEventA Test_ReportEventA
  67 #define RegisterEventSourceA Test_RegisterEventSourceA
  68 #endif // TESTEVT
  69
  70
  71 // Event message ids,
  72 // should be identical to MSG_SYSLOG* in "syslogevt.h"
  73 // (generated by "mc" from "syslogevt.mc")
  74 #define MSG_SYSLOG                       0x00000000L
  75 #define MSG_SYSLOG_01                    0x00000001L
  76 // ...
  77 #define MSG_SYSLOG_10                    0x0000000AL
  78
  79 static char sl_ident[100];
  80 static char sl_logpath[sizeof(sl_ident) + sizeof("0.log")-1];
  81 static FILE * sl_logfile;
  82 static char sl_pidstr[16];
  83 static HANDLE sl_hevtsrc;
  84
  85
  86 // Ring buffer for event log output via thread
  87 #define MAXLINES 10
  88 #define LINELEN 200
  89
  90 static HANDLE evt_hthread;
  91 static char evt_lines[MAXLINES][LINELEN+1];
  92 static int evt_priorities[MAXLINES];
  93 static volatile int evt_timeout;
  94 static int evt_index_in, evt_index_out;
  95 static HANDLE evt_wait_in, evt_wait_out;
  96
  97
  98 // Map syslog priority to event type
  99
 100 static WORD pri2evtype(int priority)
 101 {
 102         switch (priority) {
 103                 default:
 104                 case LOG_EMERG: case LOG_ALERT:
 105                 case LOG_CRIT:  case LOG_ERR:
 106                         return EVENTLOG_ERROR_TYPE;
 107                 case LOG_WARNING:
 108                         return EVENTLOG_WARNING_TYPE;
 109                 case LOG_NOTICE: case LOG_INFO:
 110                 case LOG_DEBUG:
 111                         return EVENTLOG_INFORMATION_TYPE;
 112         }
 113 }
 114
 115
 116 // Map syslog priority to string
 117
 118 static const char * pri2text(int priority)
 119 {
 120         switch (priority) {
 121                 case LOG_EMERG:   return "EMERG";
 122                 case LOG_ALERT:   return "ALERT";
 123                 case LOG_CRIT:    return "CRIT";
 124                 default:
 125                 case LOG_ERR:     return "ERROR";
 126                 case LOG_WARNING: return "Warn";
 127                 case LOG_NOTICE:  return "Note";
 128                 case LOG_INFO:    return "Info";
 129                 case LOG_DEBUG:   return "Debug";
 130         }
 131 }
 132
 133
 134 // Output cnt events from ring buffer
 135
 136 static void report_events(int cnt)
 137 {
 138         const char * msgs[3+MAXLINES];
 139
 140         int i, pri;
 141         if (cnt <= 0)
 142                 return;
 143         if (cnt > MAXLINES)
 144                 cnt = MAXLINES;
 145
 146         pri = evt_priorities[evt_index_out];
 147
 148         msgs[0] = sl_ident;
 149         msgs[1] = sl_pidstr;
 150         msgs[2] = pri2text(pri);
 151         for (i = 0; i < cnt; i++) {
 152                 //assert(evt_priorities[evt_index_out] == pri);
 153                 msgs[3+i] = evt_lines[evt_index_out];
 154                 if (++evt_index_out >= MAXLINES)
 155                         evt_index_out = 0;
 156         }
 157         ReportEventA(sl_hevtsrc,
 158                 pri2evtype(pri), // type
 159                 0, MSG_SYSLOG+cnt,    // category, message id
 160                 NULL,                 // no security id
 161                 (WORD)(3+cnt), 0,     // 3+cnt strings, ...
 162                 msgs, NULL);          // ...          , no data
 163 }
 164
 165
 166 // Thread to combine several syslog lines into one event log entry
 167
 168 static ULONG WINAPI event_logger_thread(LPVOID arg)
 169 {
 170         int cnt;
 171         ARGUSED(arg);
 172
 173         cnt = 0;
 174         for (;;) {
 175                 // Wait for first line ...
 176                 int prior, i, rest;
 177                 if (cnt == 0) {
 178                         if (WaitForSingleObject(evt_wait_out, (evt_timeout? INFINITE : 0)) != WAIT_OBJECT_0)
 179                                 break;
 180                         cnt = 1;
 181                 }
 182
 183                 // ... wait some time for more lines with same prior
 184                 i = evt_index_out;
 185                 prior = evt_priorities[i];
 186                 rest = 0;
 187                 while (cnt < MAXLINES) {
 188                         long timeout =
 189                                 evt_timeout * ((1000L * (MAXLINES-cnt+1))/MAXLINES);
 190                         if (WaitForSingleObject(evt_wait_out, timeout) != WAIT_OBJECT_0)
 191                                 break;
 192                         if (++i >= MAXLINES)
 193                                 i = 0;
 194                         if (evt_priorities[i] != prior) {
 195                                 rest = 1;
 196                                 break;
 197                         }
 198                         cnt++;
 199                 }
 200
 201                 // Output all in one event log entry
 202                 report_events(cnt);
 203
 204                 // Signal space
 205                 if (!ReleaseSemaphore(evt_wait_in, cnt, NULL))
 206                         break;
 207                 cnt = rest;
 208         }
 209         return 0;
 210 }
 211
 212
 213 static void on_exit_event_logger(void)
 214 {
 215         // Output lines immediate if exiting
 216         evt_timeout = 0;
 217         // Wait for thread to finish
 218         WaitForSingleObject(evt_hthread, 1000L);
 219         CloseHandle(evt_hthread);
 220 #if 0
 221         if (sl_hevtsrc) {
 222                 DeregisterEventSource(sl_hevtsrc); sl_hevtsrc = 0;
 223         }
 224 #else
 225         // Leave event message source open to prevent losing messages during shutdown
 226 #endif
 227 }
 228
 229
 230 static int start_event_logger()
 231 {
 232         DWORD tid;
 233         evt_timeout = 1;
 234         if (   !(evt_wait_in  = CreateSemaphore(NULL,  MAXLINES, MAXLINES, NULL))
 235                 || !(evt_wait_out = CreateSemaphore(NULL,         0, MAXLINES, NULL))) {
 236                 fprintf(stderr,"CreateSemaphore failed, Error=%ld\n", GetLastError());
 237                 return -1;
 238         }
 239         if (!(evt_hthread = CreateThread(NULL, 0, event_logger_thread, NULL, 0, &tid))) {
 240                 fprintf(stderr,"CreateThread failed, Error=%ld\n", GetLastError());
 241                 return -1;
 242         }
 243         atexit(on_exit_event_logger);
 244         return 0;
 245 }
 246
 247
 248 // Write lines to event log ring buffer
 249
 250 static void write_event_log(int priority, const char * lines)
 251 {
 252         int cnt = 0;
 253         int i;
 254         for (i = 0; lines[i]; i++) {
 255                 int len = 0;
 256                 while (lines[i+len] && lines[i+len] != '\n')
 257                         len++;
 258                         ;
 259                 if (len > 0) {
 260                         // Wait for space
 261                         if (WaitForSingleObject(evt_wait_in, INFINITE) != WAIT_OBJECT_0)
 262                                 return;
 263                         // Copy line
 264                         evt_priorities[evt_index_in] = priority;
 265                         memcpy(evt_lines[evt_index_in], lines+i, (len < LINELEN ? len : LINELEN));
 266                         if (len < LINELEN)
 267                                 evt_lines[evt_index_in][len] = 0;
 268                         if (++evt_index_in >= MAXLINES)
 269                                 evt_index_in = 0;
 270                         // Signal avail if ring buffer full
 271                         if (++cnt >= MAXLINES) {
 272                                 ReleaseSemaphore(evt_wait_out, cnt, NULL);
 273                                 cnt = 0;
 274                         }
 275                         i += len;
 276                 }
 277                 if (!lines[i])
 278                         break;
 279         }
 280
 281         // Signal avail
 282         if (cnt > 0)
 283                 ReleaseSemaphore(evt_wait_out, cnt, NULL);
 284         Sleep(1);
 285 }
 286
 287
 288 // Write lines to logfile
 289
 290 static void write_logfile(FILE * f, int priority, const char * lines)
 291 {
 292         time_t now; char stamp[sizeof("2004-04-04 10:00:00")+13];
 293         int i;
 294
 295         now = time((time_t*)0);
 296         if (!strftime(stamp, sizeof(stamp)-1, "%Y-%m-%d %H:%M:%S", localtime(&now)))
 297                 strcpy(stamp,"?");
 298
 299         for (i = 0; lines[i]; i++) {
 300                 int len = 0;
 301                 while (lines[i+len] && lines[i+len] != '\n')
 302                         len++;
 303                 if (len > 0) {
 304                         fprintf(f, "%s %s[%s]: %-5s: ",
 305                                 stamp, sl_ident, sl_pidstr, pri2text(priority));
 306                         fwrite(lines+i, len, 1, f);
 307                         fputc('\n', f);
 308                         i += len;
 309                 }
 310                 if (!lines[i])
 311                         break;
 312         }
 313 }
 314
 315
 316 void openlog(const char *ident, int logopt, int facility)
 317 {
 318         int pid;
 319         if (sl_logpath[0] || sl_logfile || sl_hevtsrc)
 320                 return; // Already open
 321
 322         strncpy(sl_ident, ident, sizeof(sl_ident)-1);
 323         // logopt==LOG_PID assumed
 324         ARGUSED(logopt);
 325         pid = getpid();
 326         if (snprintf(sl_pidstr, sizeof(sl_pidstr)-1, (pid >= 0 ? "%d" : "0x%X"), pid) < 0)
 327                 strcpy(sl_pidstr,"?");
 328
 329         if (facility == LOG_LOCAL0) // "ident.log"
 330                 strcat(strcpy(sl_logpath, sl_ident), ".log");
 331         else if (facility == LOG_LOCAL1) // stdout
 332                 sl_logfile = stdout;
 333         else if (facility == LOG_LOCAL2) // stderr
 334                 sl_logfile = stderr;
 335         else if (LOG_LOCAL2 < facility && facility <= LOG_LOCAL7) { // "ident[1-5].log"
 336                 snprintf(sl_logpath, sizeof(sl_logpath)-1, "%s%d.log",
 337                         sl_ident, LOG_FAC(facility)-LOG_FAC(LOG_LOCAL2));
 338         }
 339         else // Assume LOG_DAEMON, use event log if possible, else "ident.log"
 340         if (!(sl_hevtsrc = RegisterEventSourceA(NULL/*localhost*/, sl_ident))) {
 341                 // Cannot open => Use logfile
 342                 long err = GetLastError();
 343                 strcat(strcpy(sl_logpath, sl_ident), ".log");
 344                 fprintf(stderr, "%s: Cannot register event source (Error=%ld), writing to %s\n",
 345                         sl_ident, err, sl_logpath);
 346         }
 347         else {
 348                 // Start event log thread
 349                 start_event_logger();
 350         }
 351         //assert(sl_logpath[0] || sl_logfile || sl_hevtsrc);
 352
 353 }
 354
 355
 356 void closelog()
 357 {
 358 }
 359
 360
 361 void vsyslog(int priority, const char * message, va_list args)
 362 {
 363         char buffer[1000];
 364
 365         // Translation of %m to error text not supported yet
 366         if (strstr(message, "%m"))
 367                 message = "Internal error: \"%%m\" in log message";
 368
 369         // Format message
 370         if (vsnprintf(buffer, sizeof(buffer)-1, message, args) < 0)
 371                 strcpy(buffer, "Internal Error: buffer overflow");
 372
 373         if (sl_hevtsrc) {
 374                 // Write to event log
 375                 write_event_log(priority, buffer);
 376         }
 377         else if (sl_logfile) {
 378                 // Write to stdout/err
 379                 write_logfile(sl_logfile, priority, buffer);
 380                 fflush(sl_logfile);
 381         }
 382         else if (sl_logpath[0]) {
 383                 // Append to logfile
 384                 FILE * f;
 385                 if (!(f = fopen(sl_logpath, "a")))
 386                         return;
 387                 write_logfile(f, priority, buffer);
 388                 fclose(f);
 389         }
 390 }
 391
 392
 393 #ifdef TEST
 394 // Test program
 395
 396 void syslog(int priority, const char *message, ...)
 397 {
 398         va_list args;
 399         va_start(args, message);
 400         vsyslog(priority, message, args);
 401         va_end(args);
 402 }
 403
 404 int main(int argc, char* argv[])
 405 {
 406         int i;
 407         openlog(argc < 2 ? "test" : argv[1], LOG_PID, (argc < 3 ? LOG_DAEMON : LOG_LOCAL1));
 408         syslog(LOG_INFO,    "Info\n");
 409         syslog(LOG_WARNING, "Warning %d\n\n", 42);
 410         syslog(LOG_ERR,     "Error %s", "Fatal");
 411         for (i = 0; i < 100; i++) {
 412                 char buf[LINELEN];
 413                 if (i % 13 == 0)
 414                         Sleep(1000L);
 415                 sprintf(buf, "Log Line %d\n", i);
 416                 syslog((i % 17) ? LOG_INFO : LOG_ERR, buf);
 417         }
 418         closelog();
 419         return 0;
 420 }
 421
 422 #endif