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", 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", 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         free(t);
 123 }
 124
 125 /* change the current debug level on the fly
 126  * 0: only ERRORS
 127  * 1: + WARNINGS
 128  * 2: + INFORMATIONAL MSGS
 129  * 3: + DEBUG MSGS
 130  */
 131 int handle_debug_level_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 132 {
 133         if (argc == 0)
 134                 command_print(cmd_ctx, "debug_level: %i", debug_level);
 135
 136         if (argc > 0)
 137                 debug_level = strtoul(args[0], NULL, 0);
 138
 139         if (debug_level < 0)
 140                 debug_level = 0;
 141
 142         if (debug_level > 3)
 143                 debug_level = 3;
 144
 145         return ERROR_OK;
 146 }
 147
 148 int handle_log_output_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 149 {
 150         if (argc == 1)
 151         {
 152                 FILE* file = fopen(args[0], "w");
 153
 154                 if (file)
 155                 {
 156                         log_output = file;
 157                 }
 158         }
 159
 160         return ERROR_OK;
 161 }
 162
 163 int log_register_commands(struct command_context_s *cmd_ctx)
 164 {
 165         start = time(NULL);
 166         register_command(cmd_ctx, NULL, "log_output", handle_log_output_command,
 167                 COMMAND_ANY, "redirect logging to <file> (default: stderr)");
 168         register_command(cmd_ctx, NULL, "debug_level", handle_debug_level_command,
 169                 COMMAND_ANY, "adjust debug level <0-3>");
 170
 171         return ERROR_OK;
 172 }
 173
 174 int log_init(struct command_context_s *cmd_ctx)
 175 {
 176         /* set defaults for daemon configuration, if not set by cmdline or cfgfile */
 177         if (debug_level == -1)
 178                 debug_level = LOG_INFO;
 179
 180         if (log_output == NULL)
 181         {
 182                 log_output = stderr;
 183         }
 184
 185         return ERROR_OK;
 186 }
 187
 188 int set_log_output(struct command_context_s *cmd_ctx, FILE *output)
 189 {
 190         log_output = output;
 191         return ERROR_OK;
 192 }
 193
 194 /* add/remove log callback handler */
 195 int log_add_callback(log_callback_fn fn, void *priv)
 196 {
 197         log_callback_t *cb;
 198
 199         /* prevent the same callback to be registered more than once, just for sure */
 200         for (cb = log_callbacks; cb; cb = cb->next)
 201         {
 202                 if (cb->fn == fn && cb->priv == priv)
 203                         return ERROR_INVALID_ARGUMENTS;
 204         }
 205
 206         /* alloc memory, it is safe just to return in case of an error, no need for the caller to check this */
 207         if ((cb = malloc(sizeof(log_callback_t))) == NULL)
 208                 return ERROR_BUF_TOO_SMALL;
 209
 210         /* add item to the beginning of the linked list */
 211         cb->fn = fn;
 212         cb->priv = priv;
 213         cb->next = log_callbacks;
 214         log_callbacks = cb;
 215
 216         return ERROR_OK;
 217 }
 218
 219 int log_remove_callback(log_callback_fn fn, void *priv)
 220 {
 221         log_callback_t *cb, **p;
 222
 223         for (p = &log_callbacks; (cb = *p); p = &(*p)->next)
 224         {
 225             if (cb->fn == fn && cb->priv == priv)
 226             {
 227                 *p = cb->next;
 228                         free(cb);
 229                         return ERROR_OK;
 230                 }
 231         }
 232
 233         /* no such item */
 234         return ERROR_INVALID_ARGUMENTS;
 235 }
 236
 237 /* return allocated string w/printf() result */
 238 char *alloc_printf(const char *fmt, va_list ap)
 239 {
 240         char *string = NULL;
 241
 242         /* start by 0 to exercise all the code paths. Need minimum 2 bytes to
 243          * fit 1 char and 0 terminator. */
 244         int size = 0;
 245         int first = 1;
 246         for (;;)
 247         {
 248                 if ((string == NULL) || (!first))
 249                 {
 250                         size = size * 2 + 2;
 251                         char *t = string;
 252                         string = realloc(string, size);
 253                         if (string == NULL)
 254                         {
 255                                 if (t != NULL)
 256                                         free(t);
 257                                 return NULL;
 258                         }
 259                 }
 260
 261             int ret;
 262             ret = vsnprintf(string, size, fmt, ap);
 263             /* NB! The result of the vsnprintf() might be an *EMPTY* string! */
 264             if ((ret >= 0) && ((ret + 1) < size))
 265             {
 266                 return string;
 267             }
 268             /* there was just enough or not enough space, allocate more. */
 269             first = 0;
 270         }
 271 }