src/log.c

   1 /* the Music Player Daemon (MPD)
   2  * Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com)
   3  * This project's homepage is: http://www.musicpd.org
   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  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17  */
  18
  19 #include "log.h"
  20
  21 #include "conf.h"
  22 #include "myfprintf.h"
  23 #include "utils.h"
  24
  25 #include <assert.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <stdarg.h>
  29 #include <time.h>
  30
  31 static unsigned int logLevel = LOG_LEVEL_LOW;
  32 static int warningFlushed;
  33 static int stdout_mode = 1;
  34 static char *warningBuffer;
  35 static int out_fd = -1;
  36 static int err_fd = -1;
  37 static const char *out_filename;
  38 static const char *err_filename;
  39
  40 /* redirect stdin to /dev/null to work around a libao bug */
  41 static void redirect_stdin(void)
  42 {
  43         int fd;
  44         if ((fd = open("/dev/null", O_RDONLY)) < 0)
  45                 FATAL("failed to open /dev/null %s\n", strerror(errno));
  46         if (dup2(fd, STDIN_FILENO) < 0)
  47                 FATAL("dup2 stdin: %s\n", strerror(errno));
  48 }
  49
  50 static void redirect_logs(void)
  51 {
  52         assert(out_fd > 0);
  53         assert(err_fd > 0);
  54         if (dup2(out_fd, STDOUT_FILENO) < 0)
  55                 FATAL("problems dup2 stdout : %s\n", strerror(errno));
  56         if (dup2(err_fd, STDERR_FILENO) < 0)
  57                 FATAL("problems dup2 stderr : %s\n", strerror(errno));
  58 }
  59
  60 static const char *log_date(void)
  61 {
  62         static char buf[16];
  63         time_t t = time(NULL);
  64         strftime(buf, 16, "%b %d %H:%M : ", localtime(&t));
  65         return buf;
  66 }
  67
  68 #define BUFFER_LENGTH   4096
  69 static void buffer_warning(const char *fmt, va_list args)
  70 {
  71         char buffer[BUFFER_LENGTH];
  72         char *tmp = buffer;
  73         size_t len = BUFFER_LENGTH;
  74
  75         if (!stdout_mode) {
  76                 memcpy(buffer, log_date(), 15);
  77                 tmp += 15;
  78                 len -= 15;
  79         }
  80
  81         vsnprintf(tmp, len, fmt, args);
  82         warningBuffer = appendToString(warningBuffer, buffer);
  83
  84         va_end(args);
  85 }
  86
  87 static void do_log(FILE *fp, const char *fmt, va_list args)
  88 {
  89         if (!stdout_mode)
  90                 fwrite(log_date(), 15, 1, fp);
  91         vfprintf(fp, fmt, args);
  92 }
  93
  94 void flushWarningLog(void)
  95 {
  96         char *s = warningBuffer;
  97
  98         DEBUG("flushing warning messages\n");
  99
 100         if (warningBuffer != NULL)
 101         {
 102                 while (s != NULL) {
 103                         char *next = strchr(s, '\n');
 104                         if (next == NULL) break;
 105                         *next = '\0';
 106                         next++;
 107                         fprintf(stderr, "%s\n", s);
 108                         s = next;
 109                 }
 110
 111                 warningBuffer = NULL;
 112         }
 113
 114         warningFlushed = 1;
 115
 116         DEBUG("done flushing warning messages\n");
 117 }
 118
 119 void initLog(const int verbose)
 120 {
 121         ConfigParam *param;
 122
 123         /* unbuffer stdout, stderr is unbuffered by default, leave it */
 124         setvbuf(stdout, (char *)NULL, _IONBF, 0);
 125
 126         if (verbose) {
 127                 logLevel = LOG_LEVEL_DEBUG;
 128                 return;
 129         }
 130         if (!(param = getConfigParam(CONF_LOG_LEVEL)))
 131                 return;
 132         if (0 == strcmp(param->value, "default")) {
 133                 logLevel = LOG_LEVEL_LOW;
 134         } else if (0 == strcmp(param->value, "secure")) {
 135                 logLevel = LOG_LEVEL_SECURE;
 136         } else if (0 == strcmp(param->value, "verbose")) {
 137                 logLevel = LOG_LEVEL_DEBUG;
 138         } else {
 139                 FATAL("unknown log level \"%s\" at line %i\n",
 140                       param->value, param->line);
 141         }
 142 }
 143
 144 void open_log_files(const int use_stdout)
 145 {
 146         mode_t prev;
 147         ConfigParam *param;
 148
 149         if (use_stdout) {
 150                 flushWarningLog();
 151                 return;
 152         }
 153
 154         prev = umask(0066);
 155         param = parseConfigFilePath(CONF_LOG_FILE, 1);
 156         out_filename = param->value;
 157         out_fd = open(out_filename, O_CREAT | O_WRONLY | O_APPEND, 0666);
 158         if (out_fd < 0)
 159                 FATAL("problem opening log file \"%s\" (config line %i) for "
 160                       "writing\n", param->value, param->line);
 161
 162         param = parseConfigFilePath(CONF_ERROR_FILE, 1);
 163         err_filename = param->value;
 164         err_fd = open(err_filename, O_CREAT | O_WRONLY | O_APPEND, 0666);
 165         if (err_fd < 0)
 166                 FATAL("problem opening error file \"%s\" (config line %i) for "
 167                       "writing\n", param->value, param->line);
 168
 169         umask(prev);
 170 }
 171
 172 void setup_log_output(const int use_stdout)
 173 {
 174         fflush(NULL);
 175         if (!use_stdout) {
 176                 redirect_logs();
 177                 stdout_mode = 0;
 178                 flushWarningLog();
 179         }
 180         redirect_stdin();
 181 }
 182
 183 #define log_func(func,level,fp) \
 184 mpd_printf void func(const char *fmt, ...) \
 185 { \
 186         if (logLevel >= level) { \
 187                 va_list args; \
 188                 va_start(args, fmt); \
 189                 do_log(fp, fmt, args); \
 190                 va_end(args); \
 191         } \
 192 }
 193
 194 log_func(ERROR, 0, stderr)
 195 log_func(LOG, 0, stdout)
 196 log_func(SECURE, LOG_LEVEL_SECURE, stdout)
 197 log_func(DEBUG, LOG_LEVEL_DEBUG, stdout)
 198
 199 #undef log_func
 200
 201 void WARNING(const char *fmt, ...)
 202 {
 203         va_list args;
 204         va_start(args, fmt);
 205         if (warningFlushed) {
 206                 do_log(stderr, fmt, args);
 207         } else
 208                 buffer_warning(fmt, args);
 209         va_end(args);
 210 }
 211
 212 mpd_printf mpd_noreturn void FATAL(const char *fmt, ...)
 213 {
 214         va_list args;
 215         va_start(args, fmt);
 216         do_log(stderr, fmt, args);
 217         va_end(args);
 218         exit(EXIT_FAILURE);
 219 }
 220
 221 int cycle_log_files(void)
 222 {
 223         mode_t prev;
 224
 225         if (stdout_mode)
 226                 return 0;
 227         assert(out_filename);
 228         assert(err_filename);
 229
 230         DEBUG("Cycling log files...\n");
 231         close_log_files();
 232
 233         prev = umask(0066);
 234
 235         out_fd = open(out_filename, O_CREAT | O_WRONLY | O_APPEND, 0666);
 236         if (out_fd < 0) {
 237                 ERROR("error re-opening log file: %s\n", out_filename);
 238                 return -1;
 239         }
 240
 241         err_fd = open(err_filename, O_CREAT | O_WRONLY | O_APPEND, 0666);
 242         if (err_fd < 0) {
 243                 ERROR("error re-opening error file: %s\n", err_filename);
 244                 return -1;
 245         }
 246
 247         umask(prev);
 248
 249         redirect_logs();
 250         DEBUG("Done cycling log files\n");
 251         return 0;
 252 }
 253
 254 void close_log_files(void)
 255 {
 256         if (stdout_mode)
 257                 return;
 258         assert(out_fd > 0);
 259         assert(err_fd > 0);
 260         xclose(out_fd);
 261         xclose(err_fd);
 262 }
 263