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
  52 static void log_puts(enum log_levels level, const char *file, int line, const char *function, const char *string)
  53 {
  54         log_callback_t *cb;
  55
  56         if (level == LOG_OUTPUT)
  57         {
  58                 /* do not prepend any headers, just print out what we were given and return */
  59                 fputs(string, log_output);
  60                 fflush(log_output);
  61                 return;
  62         }
  63
  64         char *f = strrchr(file, '/');
  65         if (f != NULL)
  66                 file = f + 1;
  67
  68         if (debug_level >= LOG_DEBUG)
  69         {
  70                 /* print with count and time information */
  71                 int t=(int)(time(NULL)-start);
  72                 fprintf(log_output, "%s %d %d %s:%d %s(): %s", log_strings[level+1], count, t, file, line, function, string);
  73         }
  74         else
  75         {
  76                 /* do not print count and time */
  77                 fprintf(log_output, "%s %s:%d %s(): %s", log_strings[level+1], file, line, function, string);
  78         }
  79
  80         fflush(log_output);
  81
  82         /* Never forward LOG_DEBUG, too verbose and they can be found in the log if need be */
  83         if (level <= LOG_INFO)
  84         {
  85                 log_callback_t *cb;
  86                 for (cb = log_callbacks; cb; cb = cb->next)
  87                 {
  88                         cb->fn(cb->priv, file, line, function, string);
  89                 }
  90         }
  91 }
  92
  93 void log_printf(enum log_levels level, const char *file, int line, const char *function, const char *format, ...)
  94 {
  95         char *string;
  96
  97         count++;
  98         if (level > debug_level)
  99                 return;
 100
 101         va_list ap;
 102         va_start(ap, format);
 103
 104         string = alloc_printf(format, ap);
 105         if (string != NULL)
 106         {
 107                 log_puts(level, file, line, function, string);
 108                 free(string);
 109         }
 110
 111         va_end(ap);
 112 }
 113
 114 void log_printf_lf(enum log_levels level, const char *file, int line, const char *function, const char *format, ...)
 115 {
 116         char *string;
 117
 118         count++;
 119         if (level > debug_level)
 120                 return;
 121
 122         va_list ap;
 123         va_start(ap, format);
 124
 125         string = alloc_printf(format, ap);
 126         if (string != NULL)
 127         {
 128                 strcat(string, "\n"); /* alloc_printf guaranteed the buffer to be at least one char longer */
 129                 log_puts(level, file, line, function, string);
 130                 free(string);
 131         }
 132
 133         va_end(ap);
 134 }
 135
 136 /* change the current debug level on the fly
 137  * 0: only ERRORS
 138  * 1: + WARNINGS
 139  * 2: + INFORMATIONAL MSGS
 140  * 3: + DEBUG MSGS
 141  */
 142 int handle_debug_level_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 143 {
 144         if (argc == 0)
 145                 command_print(cmd_ctx, "debug_level: %i", debug_level);
 146
 147         if (argc > 0)
 148                 debug_level = strtoul(args[0], NULL, 0);
 149
 150         if (debug_level < 0)
 151                 debug_level = 0;
 152
 153         if (debug_level > 3)
 154                 debug_level = 3;
 155
 156         return ERROR_OK;
 157 }
 158
 159 int handle_log_output_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 160 {
 161         if (argc == 1)
 162         {
 163                 FILE* file = fopen(args[0], "w");
 164
 165                 if (file)
 166                 {
 167                         log_output = file;
 168                 }
 169         }
 170
 171         return ERROR_OK;
 172 }
 173
 174 int log_register_commands(struct command_context_s *cmd_ctx)
 175 {
 176         start = time(NULL);
 177         register_command(cmd_ctx, NULL, "log_output", handle_log_output_command,
 178                 COMMAND_ANY, "redirect logging to <file> (default: stderr)");
 179         register_command(cmd_ctx, NULL, "debug_level", handle_debug_level_command,
 180                 COMMAND_ANY, "adjust debug level <0-3>");
 181
 182         return ERROR_OK;
 183 }
 184
 185 int log_init(struct command_context_s *cmd_ctx)
 186 {
 187         /* set defaults for daemon configuration, if not set by cmdline or cfgfile */
 188         if (debug_level == -1)
 189                 debug_level = LOG_INFO;
 190
 191         if (log_output == NULL)
 192         {
 193                 log_output = stderr;
 194         }
 195
 196         return ERROR_OK;
 197 }
 198
 199 int set_log_output(struct command_context_s *cmd_ctx, FILE *output)
 200 {
 201         log_output = output;
 202         return ERROR_OK;
 203 }
 204
 205 /* add/remove log callback handler */
 206 int log_add_callback(log_callback_fn fn, void *priv)
 207 {
 208         log_callback_t *cb;
 209
 210         /* prevent the same callback to be registered more than once, just for sure */
 211         for (cb = log_callbacks; cb; cb = cb->next)
 212         {
 213                 if (cb->fn == fn && cb->priv == priv)
 214                         return ERROR_INVALID_ARGUMENTS;
 215         }
 216
 217         /* alloc memory, it is safe just to return in case of an error, no need for the caller to check this */
 218         if ((cb = malloc(sizeof(log_callback_t))) == NULL)
 219                 return ERROR_BUF_TOO_SMALL;
 220
 221         /* add item to the beginning of the linked list */
 222         cb->fn = fn;
 223         cb->priv = priv;
 224         cb->next = log_callbacks;
 225         log_callbacks = cb;
 226
 227         return ERROR_OK;
 228 }
 229
 230 int log_remove_callback(log_callback_fn fn, void *priv)
 231 {
 232         log_callback_t *cb, **p;
 233
 234         for (p = &log_callbacks; (cb = *p); p = &(*p)->next)
 235         {
 236             if (cb->fn == fn && cb->priv == priv)
 237             {
 238                 *p = cb->next;
 239                         free(cb);
 240                         return ERROR_OK;
 241                 }
 242         }
 243
 244         /* no such item */
 245         return ERROR_INVALID_ARGUMENTS;
 246 }
 247
 248 /* return allocated string w/printf() result */
 249 char *alloc_printf(const char *fmt, va_list ap)
 250 {
 251         /* no buffer at the beginning, force realloc to do the job */
 252         char *string = NULL;
 253
 254         /* start with minimal length to exercise all the code paths */
 255         int size = 1;
 256
 257         for (;;)
 258         {
 259                 size *= 2; /* double the buffer size */
 260
 261                 char *t = string;
 262                 string = realloc(string, size);
 263                 if (string == NULL)
 264                 {
 265                         if (t != NULL)
 266                                 free(t);
 267                         return NULL;
 268                 }
 269
 270             int ret;
 271                 ret = vsnprintf(string, size, fmt, ap);
 272             /* NB! The result of the vsnprintf() might be an *EMPTY* string! */
 273             if ((ret >= 0) && ((ret + 1) < size))
 274                         break;
 275
 276             /* there was just enough or not enough space, allocate more in the next round */
 277         }
 278
 279         /* the returned buffer is by principle guaranteed to be at least one character longer */
 280         return string;
 281 }