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 /* The log_printfv() 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         log_callback_t *cb;
  64
  65         if (level == LOG_OUTPUT)
  66         {
  67                 /* do not prepend any headers, just print out what we were given and return */
  68                 fputs(string, log_output);
  69                 fflush(log_output);
  70                 return;
  71         }
  72
  73         char *f = strrchr(file, '/');
  74         if (f != NULL)
  75                 file = f + 1;
  76
  77         if (strchr(buffer, '\n')!=NULL)
  78         {
  79                 if (debug_level >= LOG_DEBUG)
  80                 {
  81                         /* print with count and time information */
  82                         int t=(int)(time(NULL)-start);
  83                 fprintf(log_output, "%s %d %d %s:%d %s(): %s", log_strings[level+1], count, t, file, line, function, string);
  84                 }
  85                 else
  86                 {
  87                         /* do not print count and time */
  88                         fprintf(log_output, "%s %s:%d %s(): %s", log_strings[level+1], file, line, function, string);
  89                 }
  90         } else
  91         {
  92                 /* only entire lines are logged. Otherwise it's
  93                  * single chars intended for the log callbacks. */
  94         }
  95
  96         fflush(log_output);
  97
  98         /* Never forward LOG_DEBUG, too verbose and they can be found in the log if need be */
  99         if (level <= LOG_INFO)
 100         {
 101                 log_callback_t *cb;
 102                 for (cb = log_callbacks; cb; cb = cb->next)
 103                 {
 104                         cb->fn(cb->priv, file, line, function, string);
 105                 }
 106         }
 107 }
 108
 109 void log_printf(enum log_levels level, const char *file, int line, const char *function, const char *format, ...)
 110 {
 111         char *string;
 112
 113         count++;
 114         if (level > debug_level)
 115                 return;
 116
 117         va_list ap;
 118         va_start(ap, format);
 119
 120         string = alloc_printf(format, ap);
 121         if (string != NULL)
 122         {
 123                 log_puts(level, file, line, function, string);
 124                 free(string);
 125         }
 126
 127         va_end(ap);
 128 }
 129
 130 void log_printf_lf(enum log_levels level, const char *file, int line, const char *function, const char *format, ...)
 131 {
 132         char *string;
 133
 134         count++;
 135         if (level > debug_level)
 136                 return;
 137
 138         va_list ap;
 139         va_start(ap, format);
 140
 141         string = alloc_printf(format, ap);
 142         if (string != NULL)
 143         {
 144                 strcat(string, "\n"); /* alloc_printf guaranteed the buffer to be at least one char longer */
 145                 log_puts(level, file, line, function, string);
 146                 free(string);
 147         }
 148
 149         va_end(ap);
 150 }
 151
 152 /* change the current debug level on the fly
 153  * 0: only ERRORS
 154  * 1: + WARNINGS
 155  * 2: + INFORMATIONAL MSGS
 156  * 3: + DEBUG MSGS
 157  */
 158 int handle_debug_level_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 159 {
 160         if (argc == 0)
 161                 command_print(cmd_ctx, "debug_level: %i", debug_level);
 162
 163         if (argc > 0)
 164                 debug_level = strtoul(args[0], NULL, 0);
 165
 166         if (debug_level < 0)
 167                 debug_level = 0;
 168
 169         if (debug_level > 3)
 170                 debug_level = 3;
 171
 172         return ERROR_OK;
 173 }
 174
 175 int handle_log_output_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 176 {
 177         if (argc == 1)
 178         {
 179                 FILE* file = fopen(args[0], "w");
 180
 181                 if (file)
 182                 {
 183                         log_output = file;
 184                 }
 185         }
 186
 187         return ERROR_OK;
 188 }
 189
 190 int log_register_commands(struct command_context_s *cmd_ctx)
 191 {
 192         start = time(NULL);
 193         register_command(cmd_ctx, NULL, "log_output", handle_log_output_command,
 194                 COMMAND_ANY, "redirect logging to <file> (default: stderr)");
 195         register_command(cmd_ctx, NULL, "debug_level", handle_debug_level_command,
 196                 COMMAND_ANY, "adjust debug level <0-3>");
 197
 198         return ERROR_OK;
 199 }
 200
 201 int log_init(struct command_context_s *cmd_ctx)
 202 {
 203         /* set defaults for daemon configuration, if not set by cmdline or cfgfile */
 204         if (debug_level == -1)
 205                 debug_level = LOG_INFO;
 206
 207         if (log_output == NULL)
 208         {
 209                 log_output = stderr;
 210         }
 211
 212         return ERROR_OK;
 213 }
 214
 215 int set_log_output(struct command_context_s *cmd_ctx, FILE *output)
 216 {
 217         log_output = output;
 218         return ERROR_OK;
 219 }
 220
 221 /* add/remove log callback handler */
 222 int log_add_callback(log_callback_fn fn, void *priv)
 223 {
 224         log_callback_t *cb;
 225
 226         /* prevent the same callback to be registered more than once, just for sure */
 227         for (cb = log_callbacks; cb; cb = cb->next)
 228         {
 229                 if (cb->fn == fn && cb->priv == priv)
 230                         return ERROR_INVALID_ARGUMENTS;
 231         }
 232
 233         /* alloc memory, it is safe just to return in case of an error, no need for the caller to check this */
 234         if ((cb = malloc(sizeof(log_callback_t))) == NULL)
 235                 return ERROR_BUF_TOO_SMALL;
 236
 237         /* add item to the beginning of the linked list */
 238         cb->fn = fn;
 239         cb->priv = priv;
 240         cb->next = log_callbacks;
 241         log_callbacks = cb;
 242
 243         return ERROR_OK;
 244 }
 245
 246 int log_remove_callback(log_callback_fn fn, void *priv)
 247 {
 248         log_callback_t *cb, **p;
 249
 250         for (p = &log_callbacks; (cb = *p); p = &(*p)->next)
 251         {
 252             if (cb->fn == fn && cb->priv == priv)
 253             {
 254                 *p = cb->next;
 255                         free(cb);
 256                         return ERROR_OK;
 257                 }
 258         }
 259
 260         /* no such item */
 261         return ERROR_INVALID_ARGUMENTS;
 262 }
 263
 264 /* return allocated string w/printf() result */
 265 char *alloc_printf(const char *fmt, va_list ap)
 266 {
 267         /* no buffer at the beginning, force realloc to do the job */
 268         char *string = NULL;
 269
 270         /* start with minimal length to exercise all the code paths */
 271         int size = 1;
 272
 273         for (;;)
 274         {
 275                 size *= 2; /* double the buffer size */
 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             int ret;
 287             ret = vsnprintf(string, size, fmt, ap);
 288             /* NB! The result of the vsnprintf() might be an *EMPTY* string! */
 289             if ((ret >= 0) && ((ret + 1) < size))
 290                         break;
 291
 292             /* there was just enough or not enough space, allocate more in the next round */
 293         }
 294
 295         /* the returned buffer is by principle guaranteed to be at least one character longer */
 296                 return string;
 297 }