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 long long 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 /* The log_puts() serves to somewhat different goals:
  52  *
  53  * - logging
  54  * - feeding low-level info to the user in GDB or Telnet
  55  *
  56  * The latter dictates that strings without newline are not logged, lest there
  57  * will be *MANY log lines when sending one char at the time(e.g.
  58  * target_request.c).
  59  *
  60  */
  61 static void log_puts(enum log_levels level, const char *file, int line, const char *function, const char *string)
  62 {
  63         if (level == LOG_OUTPUT)
  64         {
  65                 /* do not prepend any headers, just print out what we were given and return */
  66                 fputs(string, log_output);
  67                 fflush(log_output);
  68                 return;
  69         }
  70
  71         char *f = strrchr(file, '/');
  72         if (f != NULL)
  73                 file = f + 1;
  74
  75         if (strchr(string, '\n')!=NULL)
  76         {
  77                 if (debug_level >= LOG_DEBUG)
  78                 {
  79                         /* print with count and time information */
  80                         int t=(int)(timeval_ms()-start);
  81                         fprintf(log_output, "%s %d %d %s:%d %s(): %s", log_strings[level+1], count, t, file, line, function, string);
  82                 }
  83                 else
  84                 {
  85                         /* do not print count and time */
  86                         fprintf(log_output, "%s %s:%d %s(): %s", log_strings[level+1], file, line, function, string);
  87                 }
  88         } else
  89         {
  90                 /* only entire lines are logged. Otherwise it's
  91                  * single chars intended for the log callbacks. */
  92         }
  93
  94         fflush(log_output);
  95
  96         /* Never forward LOG_DEBUG, too verbose and they can be found in the log if need be */
  97         if (level <= LOG_INFO)
  98         {
  99                 log_callback_t *cb, *next;
 100                 cb = log_callbacks;
 101                 /* DANGER!!!! the log callback can remove itself!!!! */
 102                 while (cb)
 103                 {
 104                         next=cb->next;
 105                         cb->fn(cb->priv, file, line, function, string);
 106                         cb=next;
 107                 }
 108         }
 109 }
 110
 111 void log_printf(enum log_levels level, const char *file, int line, const char *function, const char *format, ...)
 112 {
 113         char *string;
 114
 115         count++;
 116         if (level > debug_level)
 117                 return;
 118
 119         va_list ap;
 120         va_start(ap, format);
 121
 122         string = alloc_vprintf(format, ap);
 123         if (string != NULL)
 124         {
 125                 log_puts(level, file, line, function, string);
 126                 free(string);
 127         }
 128
 129         va_end(ap);
 130 }
 131
 132 void log_printf_lf(enum log_levels level, const char *file, int line, const char *function, const char *format, ...)
 133 {
 134         char *string;
 135
 136         count++;
 137         if (level > debug_level)
 138                 return;
 139
 140         va_list ap;
 141         va_start(ap, format);
 142
 143         string = alloc_vprintf(format, ap);
 144         if (string != NULL)
 145         {
 146                 strcat(string, "\n"); /* alloc_vprintf guaranteed the buffer to be at least one char longer */
 147                 log_puts(level, file, line, function, string);
 148                 free(string);
 149         }
 150
 151         va_end(ap);
 152 }
 153
 154 /* change the current debug level on the fly
 155  * 0: only ERRORS
 156  * 1: + WARNINGS
 157  * 2: + INFORMATIONAL MSGS
 158  * 3: + DEBUG MSGS
 159  */
 160 int handle_debug_level_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 161 {
 162         if (argc == 0)
 163                 command_print(cmd_ctx, "debug_level: %i", debug_level);
 164
 165         if (argc > 0)
 166                 debug_level = strtoul(args[0], NULL, 0);
 167
 168         if (debug_level < 0)
 169                 debug_level = 0;
 170
 171         if (debug_level > 3)
 172                 debug_level = 3;
 173
 174         return ERROR_OK;
 175 }
 176
 177 int handle_log_output_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 178 {
 179         if (argc == 1)
 180         {
 181                 FILE* file = fopen(args[0], "w");
 182
 183                 if (file)
 184                 {
 185                         log_output = file;
 186                 }
 187         }
 188
 189         return ERROR_OK;
 190 }
 191
 192 int log_register_commands(struct command_context_s *cmd_ctx)
 193 {
 194         start = timeval_ms();
 195         register_command(cmd_ctx, NULL, "log_output", handle_log_output_command,
 196                 COMMAND_ANY, "redirect logging to <file> (default: stderr)");
 197         register_command(cmd_ctx, NULL, "debug_level", handle_debug_level_command,
 198                 COMMAND_ANY, "adjust debug level <0-3>");
 199
 200         return ERROR_OK;
 201 }
 202
 203 int log_init(struct command_context_s *cmd_ctx)
 204 {
 205         /* set defaults for daemon configuration, if not set by cmdline or cfgfile */
 206         if (debug_level == -1)
 207                 debug_level = LOG_INFO;
 208
 209         if (log_output == NULL)
 210         {
 211                 log_output = stderr;
 212         }
 213
 214         return ERROR_OK;
 215 }
 216
 217 int set_log_output(struct command_context_s *cmd_ctx, FILE *output)
 218 {
 219         log_output = output;
 220         return ERROR_OK;
 221 }
 222
 223 /* add/remove log callback handler */
 224 int log_add_callback(log_callback_fn fn, void *priv)
 225 {
 226         log_callback_t *cb;
 227
 228         /* prevent the same callback to be registered more than once, just for sure */
 229         for (cb = log_callbacks; cb; cb = cb->next)
 230         {
 231                 if (cb->fn == fn && cb->priv == priv)
 232                         return ERROR_INVALID_ARGUMENTS;
 233         }
 234
 235         /* alloc memory, it is safe just to return in case of an error, no need for the caller to check this */
 236         if ((cb = malloc(sizeof(log_callback_t))) == NULL)
 237                 return ERROR_BUF_TOO_SMALL;
 238
 239         /* add item to the beginning of the linked list */
 240         cb->fn = fn;
 241         cb->priv = priv;
 242         cb->next = log_callbacks;
 243         log_callbacks = cb;
 244
 245         return ERROR_OK;
 246 }
 247
 248 int log_remove_callback(log_callback_fn fn, void *priv)
 249 {
 250         log_callback_t *cb, **p;
 251
 252         for (p = &log_callbacks; (cb = *p); p = &(*p)->next)
 253         {
 254                 if (cb->fn == fn && cb->priv == priv)
 255                 {
 256                         *p = cb->next;
 257                         free(cb);
 258                         return ERROR_OK;
 259                 }
 260         }
 261
 262         /* no such item */
 263         return ERROR_INVALID_ARGUMENTS;
 264 }
 265
 266 /* return allocated string w/printf() result */
 267 char *alloc_vprintf(const char *fmt, va_list ap)
 268 {
 269         /* no buffer at the beginning, force realloc to do the job */
 270         char *string = NULL;
 271
 272         /* start with buffer size suitable for typical messages */
 273         int size = 128;
 274
 275         for (;;)
 276         {
 277                 char *t = string;
 278                 string = realloc(string, size);
 279                 if (string == NULL)
 280                 {
 281                         if (t != NULL)
 282                                 free(t);
 283                         return NULL;
 284                 }
 285
 286                 va_list ap_copy;
 287                 va_copy(ap_copy, ap);
 288
 289                 int ret;
 290                 ret = vsnprintf(string, size, fmt, ap_copy);
 291                 /* NB! The result of the vsnprintf() might be an *EMPTY* string! */
 292                 if ((ret >= 0) && ((ret + 1) < size))
 293                         break;
 294
 295                 /* there was just enough or not enough space, allocate more in the next round */
 296                 size *= 2; /* double the buffer size */
 297         }
 298
 299         /* the returned buffer is by principle guaranteed to be at least one character longer */
 300         return string;
 301 }
 302
 303 char *alloc_printf(const char *format, ...)
 304 {
 305         char *string;
 306         va_list ap;
 307         va_start(ap, format);
 308         string = alloc_vprintf(format, ap);
 309         va_end(ap);
 310         return string;
 311 }