2 * Copyright (C) 1997-2011 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file daemon.c Some helpers for programs that detach from the console. */
11 #include <sys/types.h> /* getgrnam() */
22 /** The internal state of the daemon. */
24 /** See \ref daemon_flags. */
26 /** Set by \ref daemon_set_logfile(). */
28 /** Current loglevel, see \ref daemon_set_loglevel(). */
30 /** Used by \ref server_uptime() and \ref uptime_str(). */
32 /** The file pointer if the logfile is open. */
34 /** Used by para_log() if \p DF_LOG_HOSTNAME is set. */
36 /** Used for colored log messages. */
37 char log_colors[NUM_LOGLEVELS][COLOR_MAXLEN];
40 static struct daemon the_daemon, *me = &the_daemon;
43 * Activate default log colors.
45 * This should be called early if color support is wanted.
47 void daemon_set_default_log_colors(void)
50 static const char *default_log_colors[NUM_LOGLEVELS] = {
51 [LL_DEBUG] = "normal",
53 [LL_NOTICE] = "normal",
54 [LL_WARNING] = "yellow",
56 [LL_CRIT] = "magenta bold",
57 [LL_EMERG] = "red bold",
59 for (i = 0; i < NUM_LOGLEVELS; i++)
60 color_parse_or_die(default_log_colors[i], me->log_colors[i]);
64 * Set the color for one loglevel.
66 * \param arg The loglevel/color specifier.
68 * \a arg must be of the form "ll:[fg [bg]] [attr]".
70 * \return 1 On success, -1 on errors.
72 void daemon_set_log_color_or_die(char const *arg)
74 char *p = strchr(arg, ':');
79 ret = get_loglevel_by_name(arg);
84 color_parse_or_die(p, me->log_colors[ll]);
87 PARA_EMERG_LOG("%s: color syntax error\n", arg);
92 * Init or change the name of the log file.
94 * \param logfile_name The full path of the logfile.
96 void daemon_set_logfile(char *logfile_name)
98 free(me->logfile_name);
99 me->logfile_name = NULL;
101 me->logfile_name = para_strdup(logfile_name);
105 * Suppress log messages with severity lower than the given loglevel.
107 * \param loglevel The smallest level that should be logged.
109 void daemon_set_loglevel(char *loglevel)
111 int ret = get_loglevel_by_name(loglevel);
118 * Set one of the daemon config flags.
120 * \param flag The flag to set.
122 * \sa \ref daemon_flags.
124 void daemon_set_flag(unsigned flag)
130 * Clear one of the daemon config flags.
132 * \param flag The flag to clear.
134 * \sa \ref daemon_flags.
136 void daemon_clear_flag(unsigned flag)
141 static bool daemon_test_flag(unsigned flag)
143 return me->flags & flag;
146 static void dummy_sighandler(__a_unused int s)
151 * Do the usual stuff to become a daemon.
153 * \param parent_waits Whether the parent process should pause before exit.
155 * Fork, become session leader, cd to /, and dup fd 0, 1, 2 to /dev/null. If \a
156 * parent_waits is false, the parent process terminates immediately.
157 * Otherwise, it calls pause() to sleep until it receives \p SIGTERM or \p
158 * SIGCHLD and exits successfully thereafter. This behaviour is useful if the
159 * daemon process should not detach from the console until the child process
160 * has completed its setup.
162 * \sa fork(2), setsid(2), dup(2), pause(2).
164 void daemonize(bool parent_waits)
169 PARA_INFO_LOG("daemonizing\n");
175 signal(SIGTERM, dummy_sighandler);
176 signal(SIGCHLD, dummy_sighandler);
179 exit(EXIT_SUCCESS); /* parent exits */
181 /* become session leader */
186 null = open("/dev/null", O_RDONLY);
189 if (dup2(null, STDIN_FILENO) < 0)
191 if (dup2(null, STDOUT_FILENO) < 0)
193 if (dup2(null, STDERR_FILENO) < 0)
198 PARA_EMERG_LOG("fatal: %s\n", strerror(errno));
203 * Close the log file of the daemon.
205 void daemon_close_log(void)
209 PARA_INFO_LOG("closing logfile\n");
215 * fopen() the logfile in append mode.
217 * \return Either succeeds or exits.
219 void daemon_open_log_or_die(void)
222 if (!me->logfile_name)
224 me->logfile = fopen(me->logfile_name, "a");
226 PARA_EMERG_LOG("can not open %s: %s\n", me->logfile_name,
230 setlinebuf(me->logfile);
234 * Log the startup message containing the paraslash version.
236 void log_welcome(const char *whoami)
238 PARA_INFO_LOG("welcome to %s " PACKAGE_VERSION " ("BUILD_DATE")\n",
243 * Give up superuser privileges.
245 * \param username The user to switch to.
246 * \param groupname The group to switch to.
248 * This function returns immediately if not invoked with EUID zero. Otherwise,
249 * it tries to obtain the GID of \a groupname and the UID of \a username. On
250 * success, effective and real GID/UID and the saved set-group-ID/set-user-ID
251 * are all set accordingly. On errors, an appropriate message is logged and
252 * exit() is called to terminate the process.
254 * \sa getpwnam(3), getuid(2), setuid(2), getgrnam(2), setgid(2)
256 void drop_privileges_or_die(const char *username, const char *groupname)
264 struct group *g = getgrnam(groupname);
266 PARA_EMERG_LOG("failed to get group %s: %s\n",
267 groupname, strerror(errno));
270 if (setgid(g->gr_gid) < 0) {
271 PARA_EMERG_LOG("failed to set group id %d: %s\n",
272 (int)g->gr_gid, strerror(errno));
277 PARA_EMERG_LOG("root privileges, but no user option given\n");
280 tmp = para_strdup(username);
284 PARA_EMERG_LOG("%s: no such user\n", username);
287 PARA_INFO_LOG("dropping root privileges\n");
288 if (setuid(p->pw_uid) < 0) {
289 PARA_EMERG_LOG("failed to set effective user ID (%s)",
293 PARA_DEBUG_LOG("uid: %d, euid: %d\n", (int)getuid(), (int)geteuid());
297 * Set the server startup time.
299 * \param startuptime The value to store as the server start time.
301 * This should be called once on startup with \a startuptime either NULL or a
302 * pointer to a struct timeval which contains the current time. If \a
303 * startuptime is NULL, the server start time is set to the current time.
305 * \sa time(2), difftime(3) \ref get_server_uptime(), \ref
306 * get_server_uptime_str().
308 void set_server_start_time(const struct timeval *startuptime)
311 me->startuptime = startuptime->tv_sec;
313 time(&me->startuptime);
317 * Get the server uptime.
319 * \param current_time The current time.
321 * The \a current_time pointer may be \p NULL. In this case the function
322 * obtains the current time from the system.
324 * \return This returns the server uptime in seconds, i.e. the difference
325 * between the current time and the value stored previously via \ref
326 * set_server_start_time().
328 time_t get_server_uptime(const struct timeval *current_time)
333 return current_time->tv_sec - me->startuptime;
335 return difftime(t, me->startuptime);
339 * Construct a string containing the current uptime.
341 * \param current_time See a \ref get_server_uptime().
343 * \return A dynamically allocated string of the form "days:hours:minutes".
347 __malloc char *get_server_uptime_str(const struct timeval *current_time)
349 long t = get_server_uptime(current_time);
350 return make_message("%li:%02li:%02li", t / 86400,
351 (t / 3600) % 24, (t / 60) % 60);
355 * The log function for para_server and para_audiod.
357 * \param ll The log level.
358 * \param fmt The format string describing the log message.
360 __printf_2_3 void para_log(int ll, const char* fmt,...)
366 bool log_time = daemon_test_flag(DF_LOG_TIME), log_timing =
367 daemon_test_flag(DF_LOG_TIMING);
369 ll = PARA_MIN(ll, NUM_LOGLEVELS - 1);
370 ll = PARA_MAX(ll, LL_DEBUG);
371 if (ll < me->loglevel)
374 fp = me->logfile? me->logfile : stderr;
375 color = daemon_test_flag(DF_COLOR_LOG)? me->log_colors[ll] : NULL;
377 fprintf(fp, "%s", color);
378 if (log_time || log_timing) {
380 gettimeofday(&tv, NULL);
381 if (daemon_test_flag(DF_LOG_TIME)) { /* print date and time */
382 time_t t1 = tv.tv_sec;
385 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
386 fprintf(fp, "%s%s", str, log_timing? ":" : " ");
388 if (log_timing) /* print milliseconds */
389 fprintf(fp, "%04lu ", (long unsigned)tv.tv_usec / 1000);
391 if (daemon_test_flag(DF_LOG_HOSTNAME)) {
393 me->hostname = para_hostname();
394 fprintf(fp, "%s ", me->hostname);
396 if (daemon_test_flag(DF_LOG_LL)) /* log loglevel */
397 fprintf(fp, "(%d) ", ll);
398 if (daemon_test_flag(DF_LOG_PID)) { /* log pid */
399 pid_t mypid = getpid();
400 fprintf(fp, "(%d) ", (int)mypid);
403 vfprintf(fp, fmt, argp);
406 fprintf(fp, "%s", COLOR_RESET);