/*

   log.c - logging funtions

   Copyright (C) 2002, 2003, 2008, 2010, 2011, 2012, 2013 Arthur de Jong

   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., 51 Franklin Street, Fifth Floor, Boston, MA

   02110-1301 USA

*/

#include "config.h"

#include <stdio.h>

#include <stdlib.h>

#include <sys/types.h>

#include <unistd.h>

#include <syslog.h>

#include <stdarg.h>

#include <errno.h>

#include <string.h>

#include <time.h>

#include <pthread.h>

#include <strings.h>

#include "log.h"

/* set the logname */

#undef PACKAGE

#define PACKAGE "nslcd"

/* storage for logging modes */

static struct log_cfg {

  int loglevel;

  const char *scheme;

  FILE *fp; /* NULL == syslog */

  struct log_cfg *next;

} *loglist = NULL;

/* default loglevel when no logging is configured */

static int prelogging_loglevel = LOG_INFO;

#define MAX_REQUESTID_LENGTH 40

#ifdef TLS

/* the session id that is set for this thread */

static TLS char *sessionid = NULL;

/* the request identifier that is set for this thread */

static TLS char *requestid = NULL;

#else /* no TLS, use pthreads */

static pthread_once_t tls_init_once = PTHREAD_ONCE_INIT;

static pthread_key_t sessionid_key;

static pthread_key_t requestid_key;

static void tls_init_keys(void)

{

  pthread_key_create(&sessionid_key, NULL);

  pthread_key_create(&requestid_key, NULL);

}

#endif /* no TLS, use pthreads */

/* set loglevel when no logging is configured */

void log_setdefaultloglevel(int loglevel)

{

  prelogging_loglevel = loglevel;

}

/* add logging method to configuration list */

static void addlogging(int loglevel, const char *scheme, FILE *fp)

{

  struct log_cfg *tmp, *lst;

  /* create new logstruct */

  tmp = (struct log_cfg *)malloc(sizeof(struct log_cfg));

  if (tmp == NULL)

  {

    log_log(LOG_CRIT, "malloc() returned NULL");

    exit(EXIT_FAILURE);

  }

  tmp->loglevel = loglevel;

  tmp->scheme = scheme;

  tmp->fp = fp;

  tmp->next = NULL;

  /* save the struct in the list */

  if (loglist == NULL)

    loglist = tmp;

  else

  {

    for (lst = loglist; lst->next != NULL; lst = lst->next);

    lst->next = tmp;

  }

}

/* configure logging to a file */

void log_addlogging_file(int loglevel, const char *filename)

{

  FILE *fp;

  filename = strdup(filename);

  if (filename == NULL)

  {

    log_log(LOG_CRIT, "strdup() returned NULL");

    exit(EXIT_FAILURE);

  }

  fp = fopen(filename, "a");

  if (fp == NULL)

  {

    log_log(LOG_ERR, "cannot open logfile (%s) for appending: %s",

            filename, strerror(errno));

    exit(1);

  }

  addlogging(loglevel, filename, fp);

}

/* configure logging to syslog */

void log_addlogging_syslog(int loglevel)

{

  openlog(PACKAGE, LOG_PID, LOG_DAEMON);

  addlogging(loglevel, "syslog", NULL);

}

/* configure a null logging mode (no logging) */

void log_addlogging_none()

{

  /* this is a hack, but it's so easy */

  addlogging(LOG_EMERG, "none", NULL);

}

/* start the logging with the configured logging methods

   if no method is configured yet, logging is done to syslog */

void log_startlogging(void)

{

  if (loglist == NULL)

    log_addlogging_syslog(LOG_INFO);

  prelogging_loglevel = -1;

}

/* indicate that we should clear any session identifiers set by

   log_newsession */

void log_clearsession(void)

{

#ifndef TLS

  char *sessionid, *requestid;

  pthread_once(&tls_init_once, tls_init_keys);

  sessionid = pthread_getspecific(sessionid_key);

  requestid = pthread_getspecific(requestid_key);

#endif /* no TLS */

  /* set the session id to empty */

  if (sessionid != NULL)

    sessionid[0] = '\0';

  /* set the request id to empty */

  if (requestid != NULL)

    requestid[0] = '\0';

}

/* indicate that a session id should be included in the output

   and set it to a new value */

void log_newsession(void)

{

#ifndef TLS

  char *sessionid, *requestid;

  pthread_once(&tls_init_once, tls_init_keys);

  sessionid = pthread_getspecific(sessionid_key);

  requestid = pthread_getspecific(requestid_key);

#endif /* no TLS */

  /* ensure that sessionid can hold a string */

  if (sessionid == NULL)

  {

    sessionid = (char *)malloc(7);

    if (sessionid == NULL)

    {

      fprintf(stderr, "malloc() failed: %s", strerror(errno));

      return; /* silently fail */

    }

#ifndef TLS

    pthread_setspecific(sessionid_key, sessionid);

#endif /* no TLS */

  }

  sprintf(sessionid, "%06x", (int)(rand() & 0xffffff));

  /* set the request id to empty */

  if (requestid != NULL)

    requestid[0] = '\0';

}

/* indicate that a request identifier should be included in the output

   from this point on, until log_newsession() is called */

void log_setrequest(const char *format, ...)

{

  va_list ap;

#ifndef TLS

  char *requestid;

  pthread_once(&tls_init_once, tls_init_keys);

  requestid = pthread_getspecific(requestid_key);

#endif /* no TLS */

  /* ensure that requestid can hold a string */

  if (requestid == NULL)

  {

    requestid = (char *)malloc(MAX_REQUESTID_LENGTH);

    if (requestid == NULL)

    {

      fprintf(stderr, "malloc() failed: %s", strerror(errno));

      return; /* silently fail */

    }

#ifndef TLS

    pthread_setspecific(requestid_key, requestid);

#endif /* no TLS */

  }

  /* make the message */

  va_start(ap, format);

  vsnprintf(requestid, MAX_REQUESTID_LENGTH, format, ap);

  requestid[MAX_REQUESTID_LENGTH - 1] = '\0';

  va_end(ap);

}

/* log the given message using the configured logging method */

void log_log(int pri, const char *format, ...)

{

  int res;

  struct log_cfg *lst;

  char buffer[200];

  va_list ap;

#ifndef TLS

  char *sessionid, *requestid;

  pthread_once(&tls_init_once, tls_init_keys);

  sessionid = pthread_getspecific(sessionid_key);

  requestid = pthread_getspecific(requestid_key);

#endif /* no TLS */

  /* make the message */

  va_start(ap, format);

  res = vsnprintf(buffer, sizeof(buffer), format, ap);

  if ((res < 0) || (res >= (int)sizeof(buffer)))

  {

    /* truncate with "..." */

    buffer[sizeof(buffer) - 2] = '.';

    buffer[sizeof(buffer) - 3] = '.';

    buffer[sizeof(buffer) - 4] = '.';

  }

  buffer[sizeof(buffer) - 1] = '\0';

  va_end(ap);

  /* do the logging */

  if (prelogging_loglevel >= 0)

  {

    /* if logging is not yet defined, log to stderr */

    if (pri <= prelogging_loglevel)

    {

      if ((requestid != NULL) && (requestid[0] != '\0'))

        fprintf(stderr, "%s: [%s] <%s> %s%s\n", PACKAGE, sessionid, requestid,

                pri == LOG_DEBUG ? "DEBUG: " : "", buffer);

      else if ((sessionid != NULL) && (sessionid[0] != '\0'))

        fprintf(stderr, "%s: [%s] %s%s\n", PACKAGE, sessionid,

                pri == LOG_DEBUG ? "DEBUG: " : "", buffer);

      else

        fprintf(stderr, "%s: %s%s\n", PACKAGE,

                pri == LOG_DEBUG ? "DEBUG: " : "", buffer);

    }

  }

  else

  {

    for (lst = loglist; lst != NULL; lst = lst->next)

    {

      if (pri <= lst->loglevel)

      {

        if (lst->fp == NULL)

        {

          if ((requestid != NULL) && (requestid[0] != '\0'))

            syslog(pri, "[%s] <%s> %s%s", sessionid, requestid,

                   pri == LOG_DEBUG ? "DEBUG: " : "", buffer);

          else if ((sessionid != NULL) && (sessionid[0] != '\0'))

            syslog(pri, "[%s] %s%s", sessionid,

                   pri == LOG_DEBUG ? "DEBUG: " : "", buffer);

          else

            syslog(pri, "%s%s",

                   pri == LOG_DEBUG ? "DEBUG: " : "", buffer);

        }

        else

        {

          if ((requestid != NULL) && (requestid[0] != '\0'))

            fprintf(lst->fp, "%s: [%s] <%s> %s%s\n", PACKAGE, sessionid, requestid,

                    pri == LOG_DEBUG ? "DEBUG: " : "", buffer);

          else if ((sessionid != NULL) && (sessionid[0] != '\0'))

            fprintf(lst->fp, "%s: [%s] %s%s\n", PACKAGE, sessionid,

                    pri == LOG_DEBUG ? "DEBUG: " : "", buffer);

          else

            fprintf(lst->fp, "%s: %s%s\n", PACKAGE,

                    pri == LOG_DEBUG ? "DEBUG: " : "", buffer);

          fflush(lst->fp);

        }

      }

    }

  }

}

static const char *loglevel2str(int loglevel)

{

  switch (loglevel)

  {

    case LOG_CRIT:    return "crit";

    case LOG_ERR:     return "error";

    case LOG_WARNING: return "warning";

    case LOG_NOTICE:  return "notice";

    case LOG_INFO:    return "info";

    case LOG_DEBUG:   return "debug";

    default:          return "???";

  }

}

/* log the logging configuration on DEBUG loglevel */

void log_log_config(void)

{

  struct log_cfg *lst;

  for (lst = loglist; lst != NULL; lst = lst->next)

  {

    if (lst->loglevel == LOG_EMERG)

      log_log(LOG_DEBUG, "CFG: log %s", lst->scheme);

    else

      log_log(LOG_DEBUG, "CFG: log %s %s", lst->scheme,

              loglevel2str(lst->loglevel));

  }

}