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 #include "time_support.h"
  27
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <stdarg.h>
  32 #include <malloc.h>
  33
  34 int debug_level = -1;
  35
  36 static FILE* log_output;
  37 static log_callback_t *log_callbacks = NULL;
  38
  39 static long long start;
  40
  41 static char *log_strings[5] =
  42 {
  43         "User:   ",
  44         "Error:  ",
  45         "Warning:",
  46         "Info:   ",
  47         "Debug:  "
  48 };
  49
  50 static int count = 0;
  51
  52 /* The log_puts() serves to somewhat different goals:
  53  *
  54  * - logging
  55  * - feeding low-level info to the user in GDB or Telnet
  56  *
  57  * The latter dictates that strings without newline are not logged, lest there
  58  * will be *MANY log lines when sending one char at the time(e.g.
  59  * target_request.c).
  60  *
  61  */
  62 static void log_puts(enum log_levels level, const char *file, int line, const char *function, const char *string)
  63 {
  64         char *f;
  65         if (level == LOG_LVL_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         f = strrchr(file, '/');
  74         if (f != NULL)
  75                 file = f + 1;
  76
  77         if (strchr(string, '\n')!=NULL)
  78         {
  79                 if (debug_level >= LOG_LVL_DEBUG)
  80                 {
  81                         /* print with count and time information */
  82                         int t=(int)(timeval_ms()-start);
  83
  84                         struct mallinfo info;
  85                         info = mallinfo();
  86
  87                         fprintf(log_output, "%s %d %d %s:%d %s() %d: %s", log_strings[level+1], count, t, file, line, function, info.fordblks, string);
  88                 }
  89                 else
  90                 {
  91                         /* do not print count and time */
  92                         fprintf(log_output, "%s %s:%d %s(): %s", log_strings[level+1], file, line, function, string);
  93                 }
  94         } else
  95         {
  96                 /* only entire lines are logged. Otherwise it's
  97                  * single chars intended for the log callbacks. */
  98         }
  99
 100         fflush(log_output);
 101
 102         /* Never forward LOG_LVL_DEBUG, too verbose and they can be found in the log if need be */
 103         if (level <= LOG_LVL_INFO)
 104         {
 105                 log_callback_t *cb, *next;
 106                 cb = log_callbacks;
 107                 /* DANGER!!!! the log callback can remove itself!!!! */
 108                 while (cb)
 109                 {
 110                         next=cb->next;
 111                         cb->fn(cb->priv, file, line, function, string);
 112                         cb=next;
 113                 }
 114         }
 115 }
 116
 117 void log_printf(enum log_levels level, const char *file, int line, const char *function, const char *format, ...)
 118 {
 119         char *string;
 120         va_list ap;
 121
 122         count++;
 123         if (level > debug_level)
 124                 return;
 125
 126         va_start(ap, format);
 127
 128         string = alloc_vprintf(format, ap);
 129         if (string != NULL)
 130         {
 131                 log_puts(level, file, line, function, string);
 132                 free(string);
 133         }
 134
 135         va_end(ap);
 136 }
 137
 138 void log_printf_lf(enum log_levels level, const char *file, int line, const char *function, const char *format, ...)
 139 {
 140         char *string;
 141         va_list ap;
 142
 143         count++;
 144         if (level > debug_level)
 145                 return;
 146
 147         va_start(ap, format);
 148
 149         string = alloc_vprintf(format, ap);
 150         if (string != NULL)
 151         {
 152                 strcat(string, "\n"); /* alloc_vprintf guaranteed the buffer to be at least one char longer */
 153                 log_puts(level, file, line, function, string);
 154                 free(string);
 155         }
 156
 157         va_end(ap);
 158 }
 159
 160 /* change the current debug level on the fly
 161  * 0: only ERRORS
 162  * 1: + WARNINGS
 163  * 2: + INFORMATIONAL MSGS
 164  * 3: + DEBUG MSGS
 165  */
 166 int handle_debug_level_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 167 {
 168         if (argc == 0)
 169                 command_print(cmd_ctx, "debug_level: %i", debug_level);
 170
 171         if (argc > 0)
 172                 debug_level = strtoul(args[0], NULL, 0);
 173
 174         if (debug_level < 0)
 175                 debug_level = 0;
 176
 177         if (debug_level > 3)
 178                 debug_level = 3;
 179
 180         return ERROR_OK;
 181 }
 182
 183 int handle_log_output_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 184 {
 185         if (argc == 1)
 186         {
 187                 FILE* file = fopen(args[0], "w");
 188
 189                 if (file)
 190                 {
 191                         log_output = file;
 192                 }
 193         }
 194
 195         return ERROR_OK;
 196 }
 197
 198 int log_register_commands(struct command_context_s *cmd_ctx)
 199 {
 200         start = timeval_ms();
 201         register_command(cmd_ctx, NULL, "log_output", handle_log_output_command,
 202                 COMMAND_ANY, "redirect logging to <file> (default: stderr)");
 203         register_command(cmd_ctx, NULL, "debug_level", handle_debug_level_command,
 204                 COMMAND_ANY, "adjust debug level <0-3>");
 205
 206         return ERROR_OK;
 207 }
 208
 209 int log_init(struct command_context_s *cmd_ctx)
 210 {
 211         /* set defaults for daemon configuration, if not set by cmdline or cfgfile */
 212         if (debug_level == -1)
 213                 debug_level = LOG_LVL_INFO;
 214
 215         if (log_output == NULL)
 216         {
 217                 log_output = stderr;
 218         }
 219
 220         return ERROR_OK;
 221 }
 222
 223 int set_log_output(struct command_context_s *cmd_ctx, FILE *output)
 224 {
 225         log_output = output;
 226         return ERROR_OK;
 227 }
 228
 229 /* add/remove log callback handler */
 230 int log_add_callback(log_callback_fn fn, void *priv)
 231 {
 232         log_callback_t *cb;
 233
 234         /* prevent the same callback to be registered more than once, just for sure */
 235         for (cb = log_callbacks; cb; cb = cb->next)
 236         {
 237                 if (cb->fn == fn && cb->priv == priv)
 238                         return ERROR_INVALID_ARGUMENTS;
 239         }
 240
 241         /* alloc memory, it is safe just to return in case of an error, no need for the caller to check this */
 242         if ((cb = malloc(sizeof(log_callback_t))) == NULL)
 243                 return ERROR_BUF_TOO_SMALL;
 244
 245         /* add item to the beginning of the linked list */
 246         cb->fn = fn;
 247         cb->priv = priv;
 248         cb->next = log_callbacks;
 249         log_callbacks = cb;
 250
 251         return ERROR_OK;
 252 }
 253
 254 int log_remove_callback(log_callback_fn fn, void *priv)
 255 {
 256         log_callback_t *cb, **p;
 257
 258         for (p = &log_callbacks; (cb = *p); p = &(*p)->next)
 259         {
 260                 if (cb->fn == fn && cb->priv == priv)
 261                 {
 262                         *p = cb->next;
 263                         free(cb);
 264                         return ERROR_OK;
 265                 }
 266         }
 267
 268         /* no such item */
 269         return ERROR_INVALID_ARGUMENTS;
 270 }
 271
 272 /* return allocated string w/printf() result */
 273 char *alloc_vprintf(const char *fmt, va_list ap)
 274 {
 275         /* no buffer at the beginning, force realloc to do the job */
 276         char *string = NULL;
 277
 278         /* start with buffer size suitable for typical messages */
 279         int size = 128;
 280
 281         for (;;)
 282         {
 283                 char *t = string;
 284                 va_list ap_copy;
 285                 int ret;
 286                 string = realloc(string, size);
 287                 if (string == NULL)
 288                 {
 289                         if (t != NULL)
 290                                 free(t);
 291                         return NULL;
 292                 }
 293
 294                 va_copy(ap_copy, ap);
 295
 296                 ret = vsnprintf(string, size, fmt, ap_copy);
 297                 /* NB! The result of the vsnprintf() might be an *EMPTY* string! */
 298                 if ((ret >= 0) && ((ret + 1) < size))
 299                         break;
 300
 301                 /* there was just enough or not enough space, allocate more in the next round */
 302                 size *= 2; /* double the buffer size */
 303         }
 304
 305         /* the returned buffer is by principle guaranteed to be at least one character longer */
 306         return string;
 307 }
 308
 309 char *alloc_printf(const char *format, ...)
 310 {
 311         char *string;
 312         va_list ap;
 313         va_start(ap, format);
 314         string = alloc_vprintf(format, ap);
 315         va_end(ap);
 316         return string;
 317 }