src/helper/log.c

   1 /***************************************************************************
   2  *   Copyright (C) 2005 by Dominic Rath                                    *
   3  *   Dominic.Rath@gmx.de                                                   *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program; if not, write to the                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  19  ***************************************************************************/
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #include "log.h"
  25 #include "configuration.h"
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <stdarg.h>
  31 #include <time.h>
  32
  33 int debug_level = -1;
  34
  35 static FILE* log_output;
  36 static log_callback_t *log_callbacks = NULL;
  37
  38 static time_t start;
  39
  40 static char *log_strings[5] =
  41 {
  42         "User:   ",
  43         "Error:  ",
  44         "Warning:",
  45         "Info:   ",
  46         "Debug:  "
  47 };
  48
  49 static int count = 0;
  50
  51 static void log_printfv(enum log_levels level, const char *file, int line, const char *function, const char *format, va_list args)
  52 {
  53         char buffer[512];
  54         log_callback_t *cb;
  55
  56         vsnprintf(buffer, 512, format, args);
  57
  58         if (level == LOG_OUTPUT)
  59         {
  60                 /* do not prepend any headers, just print out what we were given and return */
  61                 fputs(buffer, log_output);
  62                 fflush(log_output);
  63                 return;
  64         }
  65
  66         char *f = strrchr(file, '/');
  67         if (f != NULL)
  68                 file = f + 1;
  69
  70         if (debug_level >= LOG_DEBUG)
  71         {
  72                 /* print with count and time information */
  73                 int t=(int)(time(NULL)-start);
  74                 fprintf(log_output, "%s %d %d %s:%d %s(): %s\n", log_strings[level+1], count, t, file, line, function, buffer);
  75         }
  76         else
  77         {
  78                 /* do not print count and time */
  79                 fprintf(log_output, "%s %s:%d %s(): %s\n", log_strings[level+1], file, line, function, buffer);
  80         }
  81
  82         fflush(log_output);
  83
  84         /* Never forward LOG_DEBUG, too verbose and they can be found in the log if need be */
  85         if (level <= LOG_INFO)
  86         {
  87                 for (cb = log_callbacks; cb; cb = cb->next)
  88                 {
  89                         cb->fn(cb->priv, file, line, function, format, args);
  90                 }
  91         }
  92 }
  93
  94 void log_printf(enum log_levels level, const char *file, int line, const char *function, const char *format, ...)
  95 {
  96         count++;
  97         if (level > debug_level)
  98                 return;
  99
 100         va_list args;
 101         va_start(args, format);
 102         log_printfv(level, file, line, function, format, args);
 103         va_end(args);
 104
 105 }
 106
 107 void log_printfnl(enum log_levels level, const char *file, int line, const char *function, const char *format, ...)
 108 {
 109         count++;
 110         if (level > debug_level)
 111                 return;
 112
 113         char *t=malloc(strlen(format)+2);
 114         strcpy(t, format);
 115         strcat(t, "\n");
 116
 117         va_list args;
 118         va_start(args, format);
 119         log_printfv(level, file, line, function, t, args);
 120         va_end(args);
 121 }
 122
 123 /* change the current debug level on the fly
 124  * 0: only ERRORS
 125  * 1: + WARNINGS
 126  * 2: + INFORMATIONAL MSGS
 127  * 3: + DEBUG MSGS
 128  */
 129 int handle_debug_level_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 130 {
 131         if (argc == 0)
 132                 command_print(cmd_ctx, "debug_level: %i", debug_level);
 133
 134         if (argc > 0)
 135                 debug_level = strtoul(args[0], NULL, 0);
 136
 137         if (debug_level < 0)
 138                 debug_level = 0;
 139
 140         if (debug_level > 3)
 141                 debug_level = 3;
 142
 143         return ERROR_OK;
 144 }
 145
 146 int handle_log_output_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 147 {
 148         if (argc == 1)
 149         {
 150                 FILE* file = fopen(args[0], "w");
 151
 152                 if (file)
 153                 {
 154                         log_output = file;
 155                 }
 156         }
 157
 158         return ERROR_OK;
 159 }
 160
 161 int log_register_commands(struct command_context_s *cmd_ctx)
 162 {
 163         start = time(NULL);
 164         register_command(cmd_ctx, NULL, "log_output", handle_log_output_command,
 165                 COMMAND_ANY, "redirect logging to <file> (default: stderr)");
 166         register_command(cmd_ctx, NULL, "debug_level", handle_debug_level_command,
 167                 COMMAND_ANY, "adjust debug level <0-3>");
 168
 169         return ERROR_OK;
 170 }
 171
 172 int log_init(struct command_context_s *cmd_ctx)
 173 {
 174         /* set defaults for daemon configuration, if not set by cmdline or cfgfile */
 175         if (debug_level == -1)
 176                 debug_level = LOG_INFO;
 177
 178         if (log_output == NULL)
 179         {
 180                 log_output = stderr;
 181         }
 182
 183         return ERROR_OK;
 184 }
 185
 186 int set_log_output(struct command_context_s *cmd_ctx, FILE *output)
 187 {
 188         log_output = output;
 189         return ERROR_OK;
 190 }
 191
 192 /* add/remove log callback handler */
 193 int log_add_callback(log_callback_fn fn, void *priv)
 194 {
 195         log_callback_t *cb;
 196
 197         /* prevent the same callback to be registered more than once, just for sure */
 198         for (cb = log_callbacks; cb; cb = cb->next)
 199         {
 200                 if (cb->fn == fn && cb->priv == priv)
 201                         return ERROR_INVALID_ARGUMENTS;
 202         }
 203
 204         /* alloc memory, it is safe just to return in case of an error, no need for the caller to check this */
 205         if ((cb = malloc(sizeof(log_callback_t))) == NULL)
 206                 return ERROR_BUF_TOO_SMALL;
 207
 208         /* add item to the beginning of the linked list */
 209         cb->fn = fn;
 210         cb->priv = priv;
 211         cb->next = log_callbacks;
 212         log_callbacks = cb;
 213
 214         return ERROR_OK;
 215 }
 216
 217 int log_remove_callback(log_callback_fn fn, void *priv)
 218 {
 219         log_callback_t *cb, **p;
 220
 221         for (p = &log_callbacks; (cb = *p); p = &(*p)->next)
 222         {
 223             if (cb->fn == fn && cb->priv == priv)
 224             {
 225                 *p = cb->next;
 226                         free(cb);
 227                         return ERROR_OK;
 228                 }
 229         }
 230
 231         /* no such item */
 232         return ERROR_INVALID_ARGUMENTS;
 233 }
 234
 235 /* return allocated string w/printf() result */
 236 char *alloc_printf(const char *fmt, va_list ap)
 237 {
 238         char *string = NULL;
 239
 240         /* start by 0 to exercise all the code paths. Need minimum 2 bytes to
 241          * fit 1 char and 0 terminator. */
 242         int size = 0;
 243         int first = 1;
 244         for (;;)
 245         {
 246                 if ((string == NULL) || (!first))
 247                 {
 248                         size = size * 2 + 2;
 249                         char *t = string;
 250                         string = realloc(string, size);
 251                         if (string == NULL)
 252                         {
 253                                 if (t != NULL)
 254                                         free(t);
 255                                 return NULL;
 256                         }
 257                 }
 258
 259             int ret;
 260             ret = vsnprintf(string, size, fmt, ap);
 261             /* NB! The result of the vsnprintf() might be an *EMPTY* string! */
 262             if ((ret >= 0) && ((ret + 1) < size))
 263             {
 264                 return string;
 265             }
 266             /* there was just enough or not enough space, allocate more. */
 267             first = 0;
 268         }
 269 }