logger.c

Go to the documentation of this file.

/***************************************************************************
    begin       : Sun Dec 05 2003
    copyright   : (C) 2025 by Martin Preuss
    email       : martin@libchipcard.de

 ***************************************************************************
 *                                                                         *
 *   This library is free software; you can redistribute it and/or         *
 *   modify it under the terms of the GNU Lesser General Public            *
 *   License as published by the Free Software Foundation; either          *
 *   version 2.1 of the License, or (at your option) any later version.    *
 *                                                                         *
 *   This library is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU     *
 *   Lesser General Public License for more details.                       *
 *                                                                         *
 *   You should have received a copy of the GNU Lesser General Public      *
 *   License along with this library; if not, write to the Free Software   *
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 *                                                                         *
 ***************************************************************************/


#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <gwenhywfar/gwenhywfarapi.h>
#include <gwenhywfar/misc.h>
#include <gwenhywfar/buffer.h>
#include <gwenhywfar/gui.h>

#include "logger_p.h"

#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#ifdef HAVE_SYSLOG_H
# include <syslog.h>
#endif
#include <string.h>
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif

#include <time.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif



/* ------------------------------------------------------------------------------------------------
 * forward declarations
 * ------------------------------------------------------------------------------------------------
 */

static GWEN_LOGGER_DOMAIN *_loggerDomain_new(const char *name);
static void _loggerDomain_free(GWEN_LOGGER_DOMAIN *ld);
static GWEN_LOGGER_DOMAIN *_loggerDomain_Find(const char *name);
static void _loggerDomain_Add(GWEN_LOGGER_DOMAIN *ld);
static void _loggerDomain_Del(GWEN_LOGGER_DOMAIN *ld);
static GWEN_LOGGER *_loggerDomain_GetLogger(const char *name);

static int _createMessage(GWEN_LOGGER *lg, GWEN_LOGGER_LEVEL priority, const char *s, GWEN_BUFFER *mbuf);
static int _logMessage(GWEN_LOGGER *lg, GWEN_LOGGER_LEVEL priority, const char *s);
static int _logMessageToFile(GWEN_LOGGER *lg, GWEN_LOGGER_LEVEL priority, const char *s);
static int _logMessageToFunction(GWEN_LOGGER *lg, GWEN_LOGGER_LEVEL priority, const char *s);
static int _logMessageToConsole(GWEN_LOGGER *lg, GWEN_LOGGER_LEVEL priority, const char *s);
#ifdef HAVE_SYSLOG_H
static int _logMessageToSyslog(GWEN_LOGGER *lg, GWEN_LOGGER_LEVEL priority, const char *s);
#endif

static GWEN_LOGGER *GWEN_Logger_new(GWEN_LOGGER_DOMAIN *domain);
static void GWEN_Logger_free(GWEN_LOGGER *lg);
/* static void GWEN_Logger_Attach(GWEN_LOGGER *lg); */


#ifndef NO_DEPRECATED_SYMBOLS

GWENHYWFAR_API void GWEN_Logger_AddLogger(GWEN_LOGGER *oldLogger, GWEN_LOGGER *newLogger) GWEN_DEPRECATED;
#endif // ifndef NO_DEPRECATED_SYMBOLS


#ifndef NO_DEPRECATED_SYMBOLS

GWENHYWFAR_API void GWEN_Logger_SetDefaultLogger(GWEN_LOGGER *lg) GWEN_DEPRECATED ;
#endif // ifndef NO_DEPRECATED_SYMBOLS



/* ------------------------------------------------------------------------------------------------
 * global vars
 * ------------------------------------------------------------------------------------------------
 */

static GWEN_LOGGER_DOMAIN *gwen_loggerdomains=NULL;



/* ------------------------------------------------------------------------------------------------
 * implementations
 * ------------------------------------------------------------------------------------------------
 */

int GWEN_Logger_ModuleInit(void)
{
  const char *s;
  GWEN_LOGGER_LEVEL ll=GWEN_LoggerLevel_Warning;

  GWEN_Logger_Open(GWEN_LOGDOMAIN, "gwen", 0, GWEN_LoggerType_Console, GWEN_LoggerFacility_User);
  s=getenv("GWEN_LOGLEVEL");
  if (s) {
    ll=GWEN_Logger_Name2Level(s);
    if (ll==GWEN_LoggerLevel_Unknown)
      ll=GWEN_LoggerLevel_Warning;
  }
  GWEN_Logger_SetLevel(GWEN_LOGDOMAIN, ll);
  return 0;
}



int GWEN_Logger_ModuleFini(void)
{
  GWEN_LOGGER_DOMAIN *ld;

  while ((ld=gwen_loggerdomains)) {
    _loggerDomain_Del(ld);
    _loggerDomain_free(ld);
  }
  return 0;
}



GWEN_LOGGER_DOMAIN *_loggerDomain_new(const char *name)
{
  GWEN_LOGGER_DOMAIN *ld;

  assert(name);
  GWEN_NEW_OBJECT(GWEN_LOGGER_DOMAIN, ld);
  ld->name=strdup(name);
  return ld;
}



void _loggerDomain_free(GWEN_LOGGER_DOMAIN *ld)
{
  if (ld) {
    free(ld->name);
    GWEN_Logger_free(ld->logger);
    GWEN_FREE_OBJECT(ld);
  }
}


GWEN_LOGGER_DOMAIN *_loggerDomain_Find(const char *name)
{
  GWEN_LOGGER_DOMAIN *ld;

  assert(name);
  ld=gwen_loggerdomains;
  while (ld) {
    if (strcasecmp(ld->name, name)==0)
      break;
    ld=ld->next;
  }

  return ld;
}



void _loggerDomain_Add(GWEN_LOGGER_DOMAIN *ld)
{
  assert(ld);
  GWEN_LIST_INSERT(GWEN_LOGGER_DOMAIN, ld, &gwen_loggerdomains);
}



void _loggerDomain_Del(GWEN_LOGGER_DOMAIN *ld)
{
  assert(ld);
  GWEN_LIST_DEL(GWEN_LOGGER_DOMAIN, ld, &gwen_loggerdomains);
}



GWEN_LOGGER *_loggerDomain_GetLogger(const char *name)
{
  GWEN_LOGGER_DOMAIN *ld;

  if (!name)
    name="default";

  ld=_loggerDomain_Find(name);
  if (ld) {
    return ld->logger;
  }
  ld=_loggerDomain_new(name);
  ld->logger=GWEN_Logger_new(ld);

  _loggerDomain_Add(ld);
  return ld->logger;
}



GWEN_LOGGER *GWEN_Logger_new(GWEN_LOGGER_DOMAIN *domain)
{
  GWEN_LOGGER *lg;

  GWEN_NEW_OBJECT(GWEN_LOGGER, lg);
  lg->usage=1;
  lg->enabled=1;
  lg->logType=GWEN_LoggerType_Console;
  lg->logLevel=GWEN_LoggerLevel_Error;
  lg->domain=domain;
  return lg;
}



void GWEN_Logger_free(GWEN_LOGGER *lg)
{
  if (lg) {
    assert(lg->usage);
    if (--(lg->usage)==0) {
      free(lg->logFile);
      free(lg->logIdent);
      GWEN_FREE_OBJECT(lg);
    }
  }
}



/*
void GWEN_Logger_Attach(GWEN_LOGGER *lg)
{
  assert(lg);
  lg->usage++;
}
*/


#ifndef NO_DEPRECATED_SYMBOLS
void GWEN_Logger_AddLogger(GWEN_LOGGER *oldLogger, GWEN_LOGGER *newLogger)
{
  assert(newLogger);

  assert(oldLogger);
  GWEN_LIST_ADD(GWEN_LOGGER, newLogger, &(oldLogger->next));
}
#endif



#ifndef NO_DEPRECATED_SYMBOLS
void GWEN_Logger_SetDefaultLogger(GWEN_UNUSED GWEN_LOGGER *lg)
{
  fprintf(stderr, "GWEN_Logger_SetDefaultLogger: Deprecated function\n");
}
#endif // ifndef NO_DEPRECATED_SYMBOLS



int GWEN_Logger_Open(const char *logDomain,
                     const char *ident,
                     const char *file,
                     GWEN_LOGGER_LOGTYPE logtype,
                     GWEN_LOGGER_FACILITY facility)
{
  GWEN_LOGGER *lg;

  lg=_loggerDomain_GetLogger(logDomain);
  assert(lg);

  if (lg->open) {
    GWEN_Logger_Log(logDomain, GWEN_LoggerLevel_Debug, "Already open");
    return 0;
  }

  lg->logType=logtype;

  GWEN_Logger_SetIdent(logDomain, ident);
  GWEN_Logger_SetFilename(logDomain, file);

  if (logtype==GWEN_LoggerType_File) {
    /* logging to a file */
    if (file==0) {
      lg->logType=GWEN_LoggerType_Console;
      lg->enabled=1;
      fprintf(stderr, "LOGGER: No filename given, will log to console.\n");
    }
    else {
      lg->logType=GWEN_LoggerType_File;
      lg->enabled=1;
    }
  }
#ifdef HAVE_SYSLOG_H
  else if (logtype==GWEN_LoggerType_Syslog) {
    /* caller wants to log via syslog */
    int fac;

    switch (facility) {
    case GWEN_LoggerFacility_Auth:
      fac=LOG_AUTH;
      break;
    case GWEN_LoggerFacility_Daemon:
      fac=LOG_DAEMON;
      break;
    case GWEN_LoggerFacility_Mail:
      fac=LOG_MAIL;
      break;
    case GWEN_LoggerFacility_News:
      fac=LOG_NEWS;
      break;
    case GWEN_LoggerFacility_User:
    case GWEN_LoggerFacility_Unknown:
    default:
      fac=LOG_USER;
      break;
    }

    openlog(ident, LOG_CONS | LOG_PID, fac);
    lg->enabled=1;
  } /* if syslog */
#endif /* ifdef HAVE_SYSLOG_H */

  else {
    /* console or function */
    lg->enabled=1;
  }

  lg->open=1;

  GWEN_Logger_Log(logDomain, GWEN_LoggerLevel_Debug, "started");
  return 0;
}



void GWEN_Logger_Close(const char *logDomain)
{
  GWEN_LOGGER *lg;

  lg=_loggerDomain_GetLogger(logDomain);
  assert(lg);
  GWEN_Logger_Log(logDomain, GWEN_LoggerLevel_Debug, "stopped");
  lg->logType=GWEN_LoggerType_Console;
  lg->enabled=0;
#ifdef HAVE_SYSLOG_H
  closelog();
#endif
  lg->open=0;
  /* remove logdomain after it has been closed */
  _loggerDomain_Del(lg->domain);
  _loggerDomain_free(lg->domain);
}



int GWEN_Logger_IsOpen(const char *logDomain)
{
  GWEN_LOGGER_DOMAIN *ld;

  if (!logDomain)
    logDomain="default";
  ld=_loggerDomain_Find(logDomain);
  return ld?(ld->logger->open):0;
}



int GWEN_Logger_CreateLogMessage(const char *logDomain, GWEN_LOGGER_LEVEL priority, const char *s, GWEN_BUFFER *mbuf)
{
  GWEN_LOGGER *lg;

  lg=_loggerDomain_GetLogger(logDomain);
  assert(lg);

  return _createMessage(lg, priority, s, mbuf);
}



void GWEN_Logger_Log(const char *logDomain, GWEN_LOGGER_LEVEL priority, const char *s)
{
  if (s) {
    GWEN_LOGGER *lg;
  
    lg=_loggerDomain_GetLogger(logDomain);
    assert(lg);
  
    if (lg->enabled) {
      if (!GWEN_Gui_LogHook(logDomain, priority, s)) {
        if (priority<=lg->logLevel) {
          const char *p;
          int slen;
          unsigned int i;
          GWEN_BUFFER *mbuf;

          /* temporarily disable logging to avoid endless loops */
          lg->enabled=0;
          slen=strlen(s);
          /* copy buffer, exchange all newlines by 0 */
          mbuf=GWEN_Buffer_new(0, slen+1, 0, 1);
          for (i=0; i<slen+1; i++) {
            if (s[i]=='\n') {
              GWEN_Buffer_AppendByte(mbuf, 0);
            }
            else
              GWEN_Buffer_AppendByte(mbuf, s[i]);
          }

          /* now log each line */
          /*rv=0;*/
          p=GWEN_Buffer_GetStart(mbuf);
          while (*p) {
            _logMessage(lg, priority, p);
            while (*p)
              p++;
            p++;
          }
          GWEN_Buffer_free(mbuf);
          /* reenable logging */
          lg->enabled=1;
        }
      }
    }
  }
}



void GWEN_Logger_Enable(const char *logDomain, int f)
{
  GWEN_LOGGER *lg;

  lg=_loggerDomain_GetLogger(logDomain);
  assert(lg);
  lg->enabled=f;
}



int GWEN_Logger_IsEnabled(const char *logDomain)
{
  GWEN_LOGGER *lg;

  lg=_loggerDomain_GetLogger(logDomain);
  assert(lg);
  return lg->enabled;
}



void GWEN_Logger_SetLevel(const char *logDomain, GWEN_LOGGER_LEVEL l)
{
  GWEN_LOGGER *lg;

  lg=_loggerDomain_GetLogger(logDomain);
  assert(lg);
  lg->logLevel=l;
}



int GWEN_Logger_GetLevel(const char *logDomain)
{
  GWEN_LOGGER *lg;

  lg=_loggerDomain_GetLogger(logDomain);
  assert(lg);

  return lg->logLevel;
}



void GWEN_Logger_SetIdent(const char *logDomain, const char *id)
{
  GWEN_LOGGER *lg;

  lg=_loggerDomain_GetLogger(logDomain);
  assert(lg);

  free(lg->logIdent);
  if (id)
    lg->logIdent=strdup(id);
  else
    lg->logIdent=strdup("No ident, please adjust your program");
}



void GWEN_Logger_SetFilename(const char *logDomain, const char *name)
{
  GWEN_LOGGER *lg;

  lg=_loggerDomain_GetLogger(logDomain);
  assert(lg);

  free(lg->logFile);
  if (name)
    lg->logFile=strdup(name);
  else
    lg->logFile=strdup("");
}



GWEN_LOGGERFUNCTIONLOG GWEN_Logger_SetLogFunction(const char *logDomain,
                                                  GWEN_LOGGERFUNCTIONLOG fn)
{
  GWEN_LOGGER *lg;
  GWEN_LOGGERFUNCTIONLOG oldFn;

  lg=_loggerDomain_GetLogger(logDomain);
  assert(lg);
  oldFn=lg->logFunction;
  lg->logFunction=fn;
  return oldFn;
}



GWEN_LOGGER_LEVEL GWEN_Logger_Name2Level(const char *name)
{
  if (strcasecmp(name, "emergency")==0)
    return GWEN_LoggerLevel_Emergency;
  else if (strcasecmp(name, "alert")==0)
    return GWEN_LoggerLevel_Alert;
  else if (strcasecmp(name, "critical")==0)
    return GWEN_LoggerLevel_Critical;
  else if (strcasecmp(name, "error")==0)
    return GWEN_LoggerLevel_Error;
  else if (strcasecmp(name, "warning")==0)
    return GWEN_LoggerLevel_Warning;
  else if (strcasecmp(name, "notice")==0)
    return GWEN_LoggerLevel_Notice;
  else if (strcasecmp(name, "info")==0)
    return GWEN_LoggerLevel_Info;
  else if (strcasecmp(name, "debug")==0)
    return GWEN_LoggerLevel_Debug;
  else if (strcasecmp(name, "verbous")==0 || strcasecmp(name, "verbose")==0)
    return GWEN_LoggerLevel_Verbous;
  else {
    return GWEN_LoggerLevel_Unknown;
  }
}



const char *GWEN_Logger_Level2Name(GWEN_LOGGER_LEVEL level)
{
  const char *s;

  switch (level) {
  case GWEN_LoggerLevel_Emergency:
    s="emergency";
    break;
  case GWEN_LoggerLevel_Alert:
    s="alert";
    break;
  case GWEN_LoggerLevel_Critical:
    s="critical";
    break;
  case GWEN_LoggerLevel_Error:
    s="error";
    break;
  case GWEN_LoggerLevel_Warning:
    s="warning";
    break;
  case GWEN_LoggerLevel_Notice:
    s="notice";
    break;
  case GWEN_LoggerLevel_Info:
    s="info";
    break;
  case GWEN_LoggerLevel_Debug:
    s="debug";
    break;
  case GWEN_LoggerLevel_Verbous:
    /* yes, we know the spelling is wrong. But it's a historic bug, fixing it would make Gwen incompatible with previous versions. */
    s="verbous";
    break;
  case GWEN_LoggerLevel_Unknown:
  default:
    s="unknown";
    break;
  } /* switch */
  return s;
}



GWEN_LOGGER_LOGTYPE GWEN_Logger_Name2Logtype(const char *name)
{
  if (strcasecmp(name, "console")==0)
    return GWEN_LoggerType_Console;
  else if (strcasecmp(name, "file")==0)
    return GWEN_LoggerType_File;
  else if (strcasecmp(name, "syslog")==0)
    return GWEN_LoggerType_Syslog;
  else if (strcasecmp(name, "function")==0)
    return GWEN_LoggerType_Function;
  else {
    return GWEN_LoggerType_Unknown;
  }
}



const char *GWEN_Logger_Logtype2Name(GWEN_LOGGER_LOGTYPE lt)
{
  const char *s;

  switch (lt) {
  case GWEN_LoggerType_Console:
    s="console";
    break;
  case GWEN_LoggerType_File:
    s="file";
    break;
  case GWEN_LoggerType_Syslog:
    s="syslog";
    break;
  case GWEN_LoggerType_Function:
    s="function";
    break;
  case GWEN_LoggerType_Unknown:
  default:
    s="unknown";
    break;
  } /* switch */
  return s;
}



int GWEN_Logger_Exists(const char *logDomain)
{
  assert(logDomain);
  return (_loggerDomain_Find(logDomain)!=0);
}






int _logMessage(GWEN_LOGGER *lg, GWEN_LOGGER_LEVEL priority, const char *s)
{
  while (lg) {
    if (priority<=lg->logLevel) {
      int rv;

      switch (lg->logType) {
#ifdef HAVE_SYSLOG_H
      case GWEN_LoggerType_Syslog:   rv=_logMessageToSyslog(lg, priority, s);   break;
#endif /* HAVE_SYSLOG_H */
      case GWEN_LoggerType_File:     rv=_logMessageToFile(lg, priority, s);     break;
      case GWEN_LoggerType_Function: rv=_logMessageToFunction(lg, priority, s); break;
      case GWEN_LoggerType_Console:
      case GWEN_LoggerType_Unknown:
      default:                       rv=_logMessageToConsole(lg, priority, s);  break;
      break;
      } /* switch */
      if (rv<0) {
        lg->logType=GWEN_LoggerType_Console;
      }
    }
    lg=lg->next;
  } /* while lg */
  return 0;
}



int _logMessageToFile(GWEN_LOGGER *lg, GWEN_LOGGER_LEVEL priority, const char *s)
{
  FILE *f;
  GWEN_BUFFER *mbuf;
  int rv;

  mbuf=GWEN_Buffer_new(0, 256, 0, 1);
  rv=_createMessage(lg, priority, s, mbuf);
  if (rv) {
    GWEN_Buffer_free(mbuf);
    return rv;
  }

  f=fopen(lg->logFile, "a+");
  if (f==0) {
    fprintf(stderr, "LOGGER: Unable to open file \"%s\" (%s)\n", lg->logFile, strerror(errno));
    lg->logType=GWEN_LoggerType_Console;
    GWEN_Buffer_free(mbuf);
    return GWEN_ERROR_IO;
  }

  if (fwrite(GWEN_Buffer_GetStart(mbuf), GWEN_Buffer_GetUsedBytes(mbuf), 1, f)!=1) {
    fprintf(stderr, "LOGGER: Unable to write to file \"%s\" (%s)\n", lg->logFile, strerror(errno));
    fclose(f);
    lg->logType=GWEN_LoggerType_Console;
    GWEN_Buffer_free(mbuf);
    return GWEN_ERROR_IO;
  }
  if (fclose(f)) {
    fprintf(stderr, "LOGGER: Unable to close file \"%s\" (%s)\n", lg->logFile, strerror(errno));
    lg->logType=GWEN_LoggerType_Console;
    GWEN_Buffer_free(mbuf);
    return GWEN_ERROR_IO;
  }
  GWEN_Buffer_free(mbuf);

  return 0;
}



int _logMessageToConsole(GWEN_LOGGER *lg, GWEN_LOGGER_LEVEL priority, const char *s)
{
  GWEN_BUFFER *mbuf;
  int rv;

  mbuf=GWEN_Buffer_new(0, 256, 0, 1);
  rv=_createMessage(lg, priority, s, mbuf);
  if (rv) {
    GWEN_Buffer_free(mbuf);
    return rv;
  }
  fprintf(stderr, "%s", GWEN_Buffer_GetStart(mbuf));
  GWEN_Buffer_free(mbuf);

  return 0;
}



#ifdef HAVE_SYSLOG_H
int _logMessageToSyslog(GWEN_UNUSED GWEN_LOGGER *lg, GWEN_LOGGER_LEVEL priority, const char *s)
{
  int pri;

  switch (priority) {
  case GWEN_LoggerLevel_Emergency:
    pri=LOG_EMERG;
    break;
  case GWEN_LoggerLevel_Alert:
    pri=LOG_ALERT;
    break;
  case GWEN_LoggerLevel_Critical:
    pri=LOG_CRIT;
    break;
  case GWEN_LoggerLevel_Error:
    pri=LOG_ERR;
    break;
  case GWEN_LoggerLevel_Warning:
    pri=LOG_WARNING;
    break;
  case GWEN_LoggerLevel_Notice:
    pri=LOG_NOTICE;
    break;
  case GWEN_LoggerLevel_Info:
    pri=LOG_NOTICE;
    break;

  case GWEN_LoggerLevel_Debug:
  case GWEN_LoggerLevel_Verbous:
  case GWEN_LoggerLevel_Unknown:
  default:
    pri=LOG_DEBUG;
    break;
  } /* switch */
  syslog(pri, "%s", s);

  return 0;
}
#endif




int _logMessageToFunction(GWEN_LOGGER *lg, GWEN_LOGGER_LEVEL priority, const char *s)
{
  GWEN_BUFFER *mbuf;
  int rv;

  mbuf=GWEN_Buffer_new(0, 256, 0, 1);
  rv=_createMessage(lg, priority, s, mbuf);
  if (rv) {
    GWEN_Buffer_free(mbuf);
    return rv;
  }

  if (lg->logFunction==0) {
    fprintf(stderr, "LOGGER: Logtype is \"Function\", but no function is set.\n");
    GWEN_Buffer_free(mbuf);
    return GWEN_ERROR_NOT_IMPLEMENTED;
  }
  rv=_createMessage(lg, priority, s, mbuf);
  if (rv) {
    GWEN_Buffer_free(mbuf);
    return rv;
  }
  (lg->logFunction)(GWEN_Buffer_GetStart(mbuf));
  GWEN_Buffer_free(mbuf);
  return 0;
}



int _createMessage(GWEN_LOGGER *lg, GWEN_LOGGER_LEVEL priority, const char *s, GWEN_BUFFER *mbuf)
{
  struct tm *t;
  time_t tt;

  tt=time(0);
  t=localtime(&tt);

  /* priority and timestamp */
  GWEN_Buffer_AppendArgs(mbuf,
                         "%d:%04d/%02d/%02d %02d-%02d-%02d:",
                         priority, t->tm_year+1900, t->tm_mon+1, t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec);
  GWEN_Buffer_AppendString(mbuf, (lg->logIdent)?(lg->logIdent):"<empty>");
#ifdef HAVE_GETPID
  GWEN_Buffer_AppendArgs(mbuf, "(%d)", (int)getpid());
#else
  GWEN_Buffer_AppendArgs(mbuf, "(%d)", 0);
#endif
  GWEN_Buffer_AppendByte(mbuf, ':');

  GWEN_Buffer_AppendString(mbuf, s?s:"<no msg>");
  GWEN_Buffer_AppendByte(mbuf, '\n');
  return 0;
}