lib/util/debug.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Samba debug functions
   4    Copyright (C) Andrew Tridgell 2003
   5    Copyright (C) James J Myers   2003
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "system/filesys.h"
  23 #include "system/time.h"
  24 #include "dynconfig/dynconfig.h"
  25
  26 /**
  27  * @file
  28  * @brief Debug logging
  29  **/
  30
  31 /**
  32  * this global variable determines what messages are printed
  33  */
  34 int _debug_level = 0;
  35 _PUBLIC_ int *debug_level = &_debug_level;
  36 int *DEBUGLEVEL_CLASS = NULL; /* For samba 3 */
  37
  38 /* the registered mutex handlers */
  39 static struct {
  40         const char *name;
  41         struct debug_ops ops;
  42 } debug_handlers;
  43
  44 /* state variables for the debug system */
  45 static struct {
  46         int fd;
  47         enum debug_logtype logtype;
  48         const char *prog_name;
  49 } state;
  50
  51 static bool reopen_logs_scheduled;
  52 static bool check_reopen_logs(void)
  53 {
  54         if (state.fd == 0 || reopen_logs_scheduled) {
  55                 reopen_logs_scheduled = false;
  56                 reopen_logs();
  57         }
  58
  59         if (state.fd <= 0)
  60                 return false;
  61
  62         return true;
  63 }
  64
  65 _PUBLIC_ void debug_schedule_reopen_logs(void)
  66 {
  67         reopen_logs_scheduled = true;
  68 }
  69
  70 static void log_timestring(int level, const char *location, const char *func)
  71 {
  72         char *t = NULL;
  73         char *s = NULL;
  74
  75         if (!check_reopen_logs()) return;
  76
  77         if (state.logtype != DEBUG_FILE) return;
  78
  79         t = timestring(NULL, time(NULL));
  80         if (!t) return;
  81
  82         asprintf(&s, "[%s, %d %s:%s()]\n", t, level, location, func);
  83         talloc_free(t);
  84         if (!s) return;
  85
  86         write(state.fd, s, strlen(s));
  87         free(s);
  88 }
  89
  90 /**
  91   the backend for debug messages. Note that the DEBUG() macro has already
  92   ensured that the log level has been met before this is called
  93 */
  94 _PUBLIC_ void dbghdr(int level, const char *location, const char *func)
  95 {
  96         log_timestring(level, location, func);
  97         log_task_id();
  98 }
  99
 100
 101 _PUBLIC_ void dbghdrclass(int level, int class, const char *location, const char *func)
 102 {
 103         /* Simple wrapper, Samba 4 doesn't do debug classes */
 104         dbghdr(level, location, func);
 105 }
 106
 107 /**
 108   the backend for debug messages. Note that the DEBUG() macro has already
 109   ensured that the log level has been met before this is called
 110
 111   @note You should never have to call this function directly. Call the DEBUG()
 112   macro instead.
 113 */
 114 _PUBLIC_ void dbgtext(const char *format, ...)
 115 {
 116         va_list ap;
 117         char *s = NULL;
 118
 119         if (!check_reopen_logs()) return;
 120
 121         va_start(ap, format);
 122         vasprintf(&s, format, ap);
 123         va_end(ap);
 124
 125         write(state.fd, s, strlen(s));
 126         free(s);
 127 }
 128
 129 _PUBLIC_ const char *logfile = NULL;
 130
 131 /**
 132   reopen the log file (usually called because the log file name might have changed)
 133 */
 134 _PUBLIC_ void reopen_logs(void)
 135 {
 136         char *fname = NULL;
 137         int old_fd = state.fd;
 138
 139         switch (state.logtype) {
 140         case DEBUG_STDOUT:
 141                 state.fd = 1;
 142                 break;
 143
 144         case DEBUG_STDERR:
 145                 state.fd = 2;
 146                 break;
 147
 148         case DEBUG_FILE:
 149                 if (logfile && (*logfile) == '/') {
 150                         fname = strdup(logfile);
 151                 } else {
 152                         asprintf(&fname, "%s/%s.log", dyn_LOGFILEBASE, state.prog_name);
 153                 }
 154                 if (fname) {
 155                         int newfd = open(fname, O_CREAT|O_APPEND|O_WRONLY, 0600);
 156                         if (newfd == -1) {
 157                                 DEBUG(1, ("Failed to open new logfile: %s\n", fname));
 158                                 old_fd = -1;
 159                         } else {
 160                                 state.fd = newfd;
 161                         }
 162                         free(fname);
 163                 } else {
 164                         DEBUG(1, ("Failed to find name for file-based logfile!\n"));
 165                 }
 166
 167                 break;
 168         }
 169
 170         if (old_fd > 2) {
 171                 close(old_fd);
 172         }
 173 }
 174
 175 /**
 176   control the name of the logfile and whether logging will be to stdout, stderr
 177   or a file
 178 */
 179 _PUBLIC_ void setup_logging(const char *prog_name, enum debug_logtype new_logtype)
 180 {
 181         if (state.logtype < new_logtype) {
 182                 state.logtype = new_logtype;
 183         }
 184         if (prog_name) {
 185                 state.prog_name = prog_name;
 186         }
 187         reopen_logs();
 188 }
 189
 190 /**
 191   return a string constant containing n tabs
 192   no more than 10 tabs are returned
 193 */
 194 _PUBLIC_ const char *do_debug_tab(int n)
 195 {
 196         const char *tabs[] = {"", "\t", "\t\t", "\t\t\t", "\t\t\t\t", "\t\t\t\t\t",
 197                               "\t\t\t\t\t\t", "\t\t\t\t\t\t\t", "\t\t\t\t\t\t\t\t",
 198                               "\t\t\t\t\t\t\t\t\t", "\t\t\t\t\t\t\t\t\t\t"};
 199         return tabs[MIN(n, 10)];
 200 }
 201
 202
 203 /**
 204   log suspicious usage - print comments and backtrace
 205 */
 206 _PUBLIC_ void log_suspicious_usage(const char *from, const char *info)
 207 {
 208         if (!debug_handlers.ops.log_suspicious_usage) return;
 209
 210         debug_handlers.ops.log_suspicious_usage(from, info);
 211 }
 212
 213
 214 /**
 215   print suspicious usage - print comments and backtrace
 216 */
 217 _PUBLIC_ void print_suspicious_usage(const char* from, const char* info)
 218 {
 219         if (!debug_handlers.ops.print_suspicious_usage) return;
 220
 221         debug_handlers.ops.print_suspicious_usage(from, info);
 222 }
 223
 224 _PUBLIC_ uint32_t get_task_id(void)
 225 {
 226         if (debug_handlers.ops.get_task_id) {
 227                 return debug_handlers.ops.get_task_id();
 228         }
 229         return getpid();
 230 }
 231
 232 _PUBLIC_ void log_task_id(void)
 233 {
 234         if (!debug_handlers.ops.log_task_id) return;
 235
 236         if (!check_reopen_logs()) return;
 237
 238         debug_handlers.ops.log_task_id(state.fd);
 239 }
 240
 241 /**
 242   register a set of debug handlers.
 243 */
 244 _PUBLIC_ void register_debug_handlers(const char *name, struct debug_ops *ops)
 245 {
 246         debug_handlers.name = name;
 247         debug_handlers.ops = *ops;
 248 }