daemon/log.c

   1 /* -*- Mode: C ; c-basic-offset: 2 -*- */
   2 /*
   3  * LADI Session Handler (ladish)
   4  *
   5  * Copyright (C) 2008, 2009, 2010 Nedko Arnaudov <nedko@arnaudov.name>
   6  * Copyright (C) 2008 Marc-Olivier Barre
   7  *
   8  **************************************************************************
   9  * This file contains code that implements logging functionality
  10  **************************************************************************
  11  *
  12  * LADI Session Handler is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * LADI Session Handler is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with LADI Session Handler. If not, see <http://www.gnu.org/licenses/>
  24  * or write to the Free Software Foundation, Inc.,
  25  * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  26  */
  27
  28 #include "../common.h"
  29
  30 #include <errno.h>
  31 #include <time.h>
  32 #include <stdarg.h>
  33 #include <sys/stat.h>
  34
  35 #include "../common/catdup.h"
  36 #include "../common/dirhelpers.h"
  37
  38 #define DEFAULT_XDG_LOG "/.log"
  39 #define LADISH_XDG_SUBDIR "/" BASE_NAME
  40 #define LADISH_XDG_LOG "/" BASE_NAME ".log"
  41
  42 static ino_t g_log_file_ino;
  43 static FILE * g_logfile;
  44 static char * g_log_filename;
  45
  46 static bool ladish_log_open(void)
  47 {
  48     struct stat st;
  49     int ret;
  50     int retry;
  51
  52     if (g_logfile != NULL)
  53     {
  54         ret = stat(g_log_filename, &st);
  55         if (ret != 0 || g_log_file_ino != st.st_ino)
  56         {
  57             fclose(g_logfile);
  58         }
  59         else
  60         {
  61             return true;
  62         }
  63     }
  64
  65     for (retry = 0; retry < 10; retry++)
  66     {
  67         g_logfile = fopen(g_log_filename, "a");
  68         if (g_logfile == NULL)
  69         {
  70             fprintf(stderr, "Cannot open ladishd log file \"%s\": %d (%s)\n", g_log_filename, errno, strerror(errno));
  71             return false;
  72         }
  73
  74         ret = stat(g_log_filename, &st);
  75         if (ret == 0)
  76         {
  77             g_log_file_ino = st.st_ino;
  78             return true;
  79         }
  80
  81         fclose(g_logfile);
  82         g_logfile = NULL;
  83     }
  84
  85     fprintf(stderr, "Cannot stat just opened ladishd log file \"%s\": %d (%s). %d retries\n", g_log_filename, errno, strerror(errno), retry);
  86     return false;
  87 }
  88
  89 void ladish_log_init() __attribute__ ((constructor));
  90 void ladish_log_init()
  91 {
  92   char * ladish_log_dir;
  93   const char * home_dir;
  94   char * xdg_log_home;
  95
  96   home_dir = getenv("HOME");
  97   if (home_dir == NULL)
  98   {
  99     log_error("Environment variable HOME not set");
 100     goto exit;
 101   }
 102
 103   xdg_log_home = catdup(home_dir, DEFAULT_XDG_LOG);
 104   if (xdg_log_home == NULL)
 105   {
 106     log_error("catdup failed for '%s' and '%s'", home_dir, DEFAULT_XDG_LOG);
 107     goto exit;
 108   }
 109
 110   ladish_log_dir = catdup(xdg_log_home, LADISH_XDG_SUBDIR);
 111   if (ladish_log_dir == NULL)
 112   {
 113     log_error("catdup failed for '%s' and '%s'", home_dir, LADISH_XDG_SUBDIR);
 114     goto free_log_home;
 115   }
 116
 117   if (!ensure_dir_exist(xdg_log_home, 0700))
 118   {
 119     goto free_log_dir;
 120   }
 121
 122   if (!ensure_dir_exist(ladish_log_dir, 0700))
 123   {
 124     goto free_log_dir;
 125   }
 126
 127   g_log_filename = catdup(ladish_log_dir, LADISH_XDG_LOG);
 128   if (g_log_filename == NULL)
 129   {
 130     log_error("Out of memory");
 131     goto free_log_dir;
 132   }
 133
 134   ladish_log_open();
 135
 136 free_log_dir:
 137   free(ladish_log_dir);
 138
 139 free_log_home:
 140   free(xdg_log_home);
 141
 142 exit:
 143   return;
 144 }
 145
 146 void ladish_log_uninit()  __attribute__ ((destructor));
 147 void ladish_log_uninit()
 148 {
 149   if (g_logfile != NULL)
 150   {
 151     fclose(g_logfile);
 152   }
 153
 154   free(g_log_filename);
 155 }
 156
 157 void
 158 ladish_log(
 159   unsigned int level,
 160   const char * format,
 161   ...)
 162 {
 163   va_list ap;
 164   FILE * stream;
 165   time_t timestamp;
 166   char timestamp_str[26];
 167
 168   if (g_logfile != NULL && ladish_log_open())
 169   {
 170     stream = g_logfile;
 171   }
 172   else
 173   {
 174     switch (level)
 175     {
 176     case LADISH_LOG_LEVEL_DEBUG:
 177     case LADISH_LOG_LEVEL_INFO:
 178       stream = stdout;
 179       break;
 180     case LADISH_LOG_LEVEL_WARN:
 181     case LADISH_LOG_LEVEL_ERROR:
 182     case LADISH_LOG_LEVEL_ERROR_PLAIN:
 183     default:
 184       stream = stderr;
 185     }
 186   }
 187
 188   time(&timestamp);
 189   ctime_r(&timestamp, timestamp_str);
 190   timestamp_str[24] = 0;
 191
 192   fprintf(stream, "%s: ", timestamp_str);
 193
 194   va_start(ap, format);
 195   vfprintf(stream, format, ap);
 196   fflush(stream);
 197   va_end(ap);
 198 }