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 void log_printf(enum log_levels level, const char *file, int line, const char *function, const char *format, ...)
  50 {
  51         static int count = 0;
  52         count++;
  53         va_list args;
  54         char buffer[512];
  55         log_callback_t *cb;
  56
  57         if (level > debug_level)
  58                 return;
  59
  60         va_start(args, format);
  61         vsnprintf(buffer, 512, format, args);
  62         va_end(args);
  63
  64         if (level == LOG_OUTPUT)
  65         {
  66                 /* do not prepend any headers, just print out what we were given and return */
  67                 fputs(buffer, log_output);
  68                 fflush(log_output);
  69                 return;
  70         }
  71
  72         char *f = strrchr(file, '/');
  73         if (f != NULL)
  74                 file = f + 1;
  75
  76         if (debug_level >= LOG_DEBUG)
  77         {
  78                 /* print with count and time information */
  79                 time_t t=time(NULL)-start;
  80                 fprintf(log_output, "%s %d %ld %s:%d %s(): %s\n", log_strings[level+1], count, t, file, line, function, buffer);
  81         }
  82         else
  83         {
  84                 /* do not print count and time */
  85                 fprintf(log_output, "%s %s:%d %s(): %s\n", log_strings[level+1], file, line, function, buffer);
  86         }
  87
  88         fflush(log_output);
  89
  90         /* Never forward LOG_DEBUG, too verbose and they can be found in the log if need be */
  91         if (level <= LOG_INFO)
  92         {
  93                 for (cb = log_callbacks; cb; cb = cb->next)
  94                 {
  95                         va_start(args, format);
  96                         cb->fn(cb->priv, file, line, function, format, args);
  97                         va_end(args);
  98                 }
  99         }
 100 }
 101
 102 /* change the current debug level on the fly
 103  * 0: only ERRORS
 104  * 1: + WARNINGS
 105  * 2: + INFORMATIONAL MSGS
 106  * 3: + DEBUG MSGS
 107  */
 108 int handle_debug_level_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 109 {
 110         if (argc == 0)
 111                 command_print(cmd_ctx, "debug_level: %i", debug_level);
 112
 113         if (argc > 0)
 114                 debug_level = strtoul(args[0], NULL, 0);
 115
 116         if (debug_level < 0)
 117                 debug_level = 0;
 118
 119         if (debug_level > 3)
 120                 debug_level = 3;
 121
 122         return ERROR_OK;
 123 }
 124
 125 int handle_log_output_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 126 {
 127         if (argc == 1)
 128         {
 129                 FILE* file = fopen(args[0], "w");
 130
 131                 if (file)
 132                 {
 133                         log_output = file;
 134                 }
 135         }
 136
 137         return ERROR_OK;
 138 }
 139
 140 int log_register_commands(struct command_context_s *cmd_ctx)
 141 {
 142         start = time(NULL);
 143         register_command(cmd_ctx, NULL, "log_output", handle_log_output_command,
 144                 COMMAND_ANY, "redirect logging to <file> (default: stderr)");
 145         register_command(cmd_ctx, NULL, "debug_level", handle_debug_level_command,
 146                 COMMAND_ANY, "adjust debug level <0-3>");
 147
 148         return ERROR_OK;
 149 }
 150
 151 int log_init(struct command_context_s *cmd_ctx)
 152 {
 153         /* set defaults for daemon configuration, if not set by cmdline or cfgfile */
 154         if (debug_level == -1)
 155                 debug_level = LOG_INFO;
 156
 157         if (log_output == NULL)
 158         {
 159                 log_output = stderr;
 160         }
 161
 162         return ERROR_OK;
 163 }
 164
 165 int set_log_output(struct command_context_s *cmd_ctx, FILE *output)
 166 {
 167         log_output = output;
 168         return ERROR_OK;
 169 }
 170
 171 /* add/remove log callback handler */
 172 int log_add_callback(log_callback_fn fn, void *priv)
 173 {
 174         log_callback_t *cb;
 175
 176         /* prevent the same callback to be registered more than once, just for sure */
 177         for (cb = log_callbacks; cb; cb = cb->next)
 178         {
 179                 if (cb->fn == fn && cb->priv == priv)
 180                         return ERROR_INVALID_ARGUMENTS;
 181         }
 182
 183         /* alloc memory, it is safe just to return in case of an error, no need for the caller to check this */
 184         if ((cb = malloc(sizeof(log_callback_t))) == NULL)
 185                 return ERROR_BUF_TOO_SMALL;
 186
 187         /* add item to the beginning of the linked list */
 188         cb->fn = fn;
 189         cb->priv = priv;
 190         cb->next = log_callbacks;
 191         log_callbacks = cb;
 192
 193         return ERROR_OK;
 194 }
 195
 196 int log_remove_callback(log_callback_fn fn, void *priv)
 197 {
 198         log_callback_t *cb, **p;
 199
 200         for (p = &log_callbacks; (cb = *p); p = &(*p)->next)
 201         {
 202             if (cb->fn == fn && cb->priv == priv)
 203             {
 204                 *p = cb->next;
 205                         free(cb);
 206                         return ERROR_OK;
 207                 }
 208         }
 209
 210         /* no such item */
 211         return ERROR_INVALID_ARGUMENTS;
 212 }
 213
 214 /* return allocated string w/printf() result */
 215 char *alloc_printf(const char *fmt, va_list ap)
 216 {
 217         char *string = NULL;
 218
 219         /* start by 0 to exercise all the code paths. Need minimum 2 bytes to
 220          * fit 1 char and 0 terminator. */
 221         int size = 0;
 222         int first = 1;
 223         for (;;)
 224         {
 225                 if ((string == NULL) || (!first))
 226                 {
 227                         size = size * 2 + 2;
 228                         char *t = string;
 229                         string = realloc(string, size);
 230                         if (string == NULL)
 231                         {
 232                                 if (t != NULL)
 233                                         free(t);
 234                                 return NULL;
 235                         }
 236                 }
 237
 238             int ret;
 239             ret = vsnprintf(string, size, fmt, ap);
 240             /* NB! The result of the vsnprintf() might be an *EMPTY* string! */
 241             if ((ret >= 0) && ((ret + 1) < size))
 242             {
 243                 return string;
 244             }
 245             /* there was just enough or not enough space, allocate more. */
 246             first = 0;
 247         }
 248 }