1 /* Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
3 /** \file daemon.c Some helpers for programs that detach from the console. */
7 #include <sys/types.h> /* getgrnam() */
10 #include <sys/resource.h>
17 /** The internal state of the daemon. */
19 /** See \ref daemon_flags. */
21 /** Set by \ref daemon_set_logfile(). */
23 /** Current loglevel, see \ref daemon_set_loglevel(). */
25 /** Used by \ref server_uptime() and \ref uptime_str(). */
27 /** The file pointer if the logfile is open. */
29 /** Used by para_log() if \p DF_LOG_HOSTNAME is set. */
31 /** Used for colored log messages. */
32 char log_colors[NUM_LOGLEVELS][COLOR_MAXLEN];
36 static struct daemon the_daemon, *me = &the_daemon;
38 static void daemon_set_default_log_colors(void)
41 static const char *default_log_colors[NUM_LOGLEVELS] = {
42 [LL_DEBUG] = "normal",
44 [LL_NOTICE] = "normal",
45 [LL_WARNING] = "yellow",
47 [LL_CRIT] = "magenta bold",
48 [LL_EMERG] = "red bold",
50 for (i = 0; i < NUM_LOGLEVELS; i++)
51 color_parse_or_die(default_log_colors[i], me->log_colors[i]);
55 * Set the color for one loglevel.
57 * \param arg Must be of the form "ll:[fg [bg]] [attr]".
59 void daemon_set_log_color_or_die(const char *arg)
61 char *p = strchr(arg, ':');
66 ret = get_loglevel_by_name(arg);
71 color_parse_or_die(p, me->log_colors[ll]);
74 PARA_EMERG_LOG("%s: invalid color argument\n", arg);
79 * Initialize color mode if necessary.
81 * \param color_arg The argument given to --color.
82 * \param color_arg_auto The value for automatic color detection.
83 * \param color_arg_no The value to disable colored log messages.
84 * \param logfile_given In auto mode colors are disabled if this value is true.
86 * If color_arg equals color_arg_no, color mode is disabled. That is, calls to
87 * para_log() will not produce colored output. If color_arg equals
88 * color_arg_auto, the function detects automatically whether to activate
89 * colors. Otherwise color mode is enabled.
91 * If color mode is to be enabled, the default colors are set for each
92 * loglevel. They can be overwritten by calling daemon_set_log_color_or_die().
94 * \return Whether colors have been enabled by the function.
96 bool daemon_init_colors_or_die(int color_arg, int color_arg_auto,
97 int color_arg_no, bool logfile_given)
99 if (color_arg == color_arg_no)
101 if (color_arg == color_arg_auto) {
104 if (!isatty(STDERR_FILENO))
107 daemon_set_flag(DF_COLOR_LOG);
108 daemon_set_default_log_colors();
113 * Init or change the name of the log file.
115 * \param logfile_name The full path of the logfile.
117 void daemon_set_logfile(const char *logfile_name)
119 free(me->logfile_name);
120 me->logfile_name = NULL;
123 if (me->old_cwd && logfile_name[0] != '/')
124 me->logfile_name = make_message("%s/%s", me->old_cwd,
127 me->logfile_name = para_strdup(logfile_name);
131 * Suppress log messages with severity lower than the given loglevel.
133 * \param loglevel The smallest level that should be logged.
135 void daemon_set_loglevel(const char *loglevel)
137 int ret = get_loglevel_by_name(loglevel);
144 * Set one of the daemon config flags.
146 * \param flag The flag to set.
148 * \sa \ref daemon_flags.
150 void daemon_set_flag(unsigned flag)
155 static bool daemon_test_flag(unsigned flag)
157 return me->flags & flag;
161 * Do the usual stuff to become a daemon.
163 * \param parent_waits Whether the parent process should pause before exit.
165 * Fork, become session leader, cd to /, and dup fd 0, 1, 2 to /dev/null. If \a
166 * parent_waits is false, the parent process terminates immediately.
167 * Otherwise, a pipe is created prior to the fork() and the parent tries to
168 * read a single byte from the reading end of the pipe. The child is supposed
169 * to write to the writing end of the pipe after it completed its setup
170 * procedure successfully. This behaviour is useful to let the parent process
171 * die with an error if the child process aborts early, since in this case the
172 * read() will return non-positive.
174 * \return This function either succeeds or calls exit(3). If parent_waits is
175 * true, the return value is the file descriptor of the writing end of the
176 * pipe. Otherwise the function returns zero.
178 * \sa fork(2), setsid(2), dup(2), pause(2).
180 int daemonize(bool parent_waits)
183 int null, pipe_fd[2];
185 if (parent_waits && pipe(pipe_fd) < 0)
187 PARA_INFO_LOG("subsequent log messages go to %s\n", me->logfile_name?
188 me->logfile_name : "/dev/null");
192 if (pid) { /* parent exits */
196 exit(read(pipe_fd[0], &c, 1) <= 0?
197 EXIT_FAILURE : EXIT_SUCCESS);
203 /* become session leader */
206 me->old_cwd = getcwd(NULL, 0);
209 null = open("/dev/null", O_RDWR);
212 if (dup2(null, STDIN_FILENO) < 0)
214 if (dup2(null, STDOUT_FILENO) < 0)
216 if (dup2(null, STDERR_FILENO) < 0)
219 return parent_waits? pipe_fd[1] : 0;
221 PARA_EMERG_LOG("fatal: %s\n", strerror(errno));
226 * Close the log file of the daemon.
228 void daemon_close_log(void)
232 PARA_INFO_LOG("closing logfile\n");
238 * fopen() the logfile in append mode.
240 * \return Either succeeds or exits.
242 void daemon_open_log_or_die(void)
246 if (!me->logfile_name)
248 new_log = fopen(me->logfile_name, "a");
250 PARA_EMERG_LOG("can not open %s: %s\n", me->logfile_name,
255 me->logfile = new_log;
256 /* equivalent to setlinebuf(), but portable */
257 setvbuf(me->logfile, NULL, _IOLBF, 0);
261 * Log the startup message containing the paraslash version.
263 * \param name The name of the executable.
265 * First the given \a name is prefixed with the string "para_". Next the git
266 * version is appended. The resulting string is logged with priority "INFO".
268 void daemon_log_welcome(const char *name)
270 PARA_INFO_LOG("welcome to para_%s-" PACKAGE_VERSION " \n", name);
274 * Renice the calling process.
276 * \param prio The priority value to set.
278 * Errors are not considered fatal, but a warning message is logged if the
279 * underlying call to setpriority(2) fails.
281 void daemon_set_priority(int prio)
283 if (setpriority(PRIO_PROCESS, 0, prio) < 0)
284 PARA_WARNING_LOG("could not set priority to %d: %s\n", prio,
289 * Give up superuser privileges.
291 * \param username The user to switch to.
292 * \param groupname The group to switch to.
294 * This function returns immediately if not invoked with EUID zero. Otherwise,
295 * it tries to obtain the GID of \a groupname and the UID of \a username. On
296 * success, effective and real GID/UID and the saved set-group-ID/set-user-ID
297 * are all set accordingly. On errors, an appropriate message is logged and
298 * exit() is called to terminate the process.
300 * \sa getpwnam(3), getuid(2), setuid(2), getgrnam(2), setgid(2)
302 void daemon_drop_privileges_or_die(const char *username, const char *groupname)
310 struct group *g = getgrnam(groupname);
312 PARA_EMERG_LOG("failed to get group %s: %s\n",
313 groupname, strerror(errno));
316 if (setgid(g->gr_gid) < 0) {
317 PARA_EMERG_LOG("failed to set group id %d: %s\n",
318 (int)g->gr_gid, strerror(errno));
323 PARA_EMERG_LOG("root privileges, but no user option given\n");
326 tmp = para_strdup(username);
330 PARA_EMERG_LOG("%s: no such user\n", username);
333 PARA_INFO_LOG("dropping root privileges\n");
334 if (setuid(p->pw_uid) < 0) {
335 PARA_EMERG_LOG("failed to set effective user ID (%s)",
339 PARA_DEBUG_LOG("uid: %d, euid: %d\n", (int)getuid(), (int)geteuid());
343 * Set the startup time.
345 * This should be called once on startup. It sets the start time to the
346 * current time. The stored time is used for retrieving the server uptime.
348 * \sa time(2), \ref daemon_get_uptime(), \ref daemon_get_uptime_str().
350 void daemon_set_start_time(void)
352 time(&me->startuptime);
358 * \param current_time The current time.
360 * The \a current_time pointer may be \p NULL. In this case the function
361 * obtains the current time from the system.
363 * \return This returns the server uptime in seconds, i.e. the difference
364 * between the current time and the value stored previously via \ref
365 * daemon_set_start_time().
367 time_t daemon_get_uptime(const struct timeval *current_time)
372 return current_time->tv_sec - me->startuptime;
374 return difftime(t, me->startuptime);
378 * Construct a string containing the current uptime.
380 * \param current_time See a \ref daemon_get_uptime().
382 * \return A dynamically allocated string of the form "days:hours:minutes".
384 __malloc char *daemon_get_uptime_str(const struct timeval *current_time)
386 long t = daemon_get_uptime(current_time);
387 return make_message("%li:%02li:%02li", t / 86400,
388 (t / 3600) % 24, (t / 60) % 60);
392 * The log function for para_server and para_audiod.
394 * \param ll The log level.
395 * \param fmt The format string describing the log message.
397 __printf_2_3 void daemon_log(int ll, const char* fmt,...)
403 bool log_time = daemon_test_flag(DF_LOG_TIME), log_timing =
404 daemon_test_flag(DF_LOG_TIMING);
406 ll = PARA_MIN(ll, NUM_LOGLEVELS - 1);
407 ll = PARA_MAX(ll, LL_DEBUG);
408 if (ll < me->loglevel)
411 fp = me->logfile? me->logfile : stderr;
412 color = daemon_test_flag(DF_COLOR_LOG)? me->log_colors[ll] : NULL;
414 fprintf(fp, "%s", color);
415 if (log_time || log_timing) {
417 clock_get_realtime(&tv);
418 if (daemon_test_flag(DF_LOG_TIME)) { /* print date and time */
419 time_t t1 = tv.tv_sec;
422 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
423 fprintf(fp, "%s%s", str, log_timing? ":" : " ");
425 if (log_timing) /* print milliseconds */
426 fprintf(fp, "%04lu ", (long unsigned)tv.tv_usec / 1000);
428 if (daemon_test_flag(DF_LOG_HOSTNAME)) {
430 me->hostname = para_hostname();
431 fprintf(fp, "%s ", me->hostname);
433 if (daemon_test_flag(DF_LOG_LL)) /* log loglevel */
434 fprintf(fp, "(%d) ", ll);
435 if (daemon_test_flag(DF_LOG_PID)) { /* log pid */
436 pid_t mypid = getpid();
437 fprintf(fp, "(%d) ", (int)mypid);
440 vfprintf(fp, fmt, argp);
443 fprintf(fp, "%s", COLOR_RESET);