2 * Copyright (C) 1997-2009 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() */
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(). */
26 /** Used by \ref server_uptime() and \ref uptime_str(). */
28 /** The file pointer if the logfile is open. */
30 /** Used by para_log() if \p DF_LOG_HOSTNAME is set. */
32 /** Used for colored log messages. */
33 char log_colors[NUM_LOGLEVELS][COLOR_MAXLEN];
36 static struct daemon the_daemon, *me = &the_daemon;
39 * Activate default log colors.
41 * This should be called early if color support is wanted.
43 void daemon_set_default_log_colors(void)
46 static const char *default_log_colors[NUM_LOGLEVELS] = {
47 [LL_DEBUG] = "normal",
49 [LL_NOTICE] = "normal",
50 [LL_WARNING] = "yellow",
52 [LL_CRIT] = "magenta bold",
53 [LL_EMERG] = "red bold",
55 for (i = 0; i < NUM_LOGLEVELS; i++) {
56 int ret = color_parse(default_log_colors[i], me->log_colors[i]);
62 * Set the color for one loglevel.
64 * \param arg The loglevel/color specifier.
66 * \a arg must be of the form "ll:[fg [bg]] [attr]".
68 * \return 1 On success, -1 on errors.
70 int daemon_set_log_color(char const *arg)
72 char *p = strchr(arg, ':');
77 ret = get_loglevel_by_name(arg);
82 ret = color_parse(p, me->log_colors[ll]);
87 PARA_ERROR_LOG("%s: color syntax error\n", arg);
93 * Init or change the name of the log file.
95 * \param logfile_name The full path of the logfile.
97 void daemon_set_logfile(char *logfile_name)
99 free(me->logfile_name);
100 me->logfile_name = NULL;
102 me->logfile_name = para_strdup(logfile_name);
106 * Suppress log messages with severity lower than the given loglevel.
108 * \param loglevel The smallest level that should be logged.
110 void daemon_set_loglevel(char *loglevel)
112 int ret = get_loglevel_by_name(loglevel);
119 * Set one of the daemon config flags.
121 * \param flag The flag to set.
123 * \sa \ref daemon_flags.
125 void daemon_set_flag(unsigned flag)
131 * Clear one of the daemon config flags.
133 * \param flag The flag to clear.
135 * \sa \ref daemon_flags.
137 void daemon_clear_flag(unsigned flag)
142 static unsigned daemon_test_flag(unsigned flag)
144 return me->flags & flag;
148 * Do the usual stuff to become a daemon.
150 * Fork, become session leader, dup fd 0, 1, 2 to /dev/null.
152 * \sa fork(2), setsid(2), dup(2).
159 PARA_INFO_LOG("daemonizing\n");
164 exit(EXIT_SUCCESS); /* parent exits */
165 /* become session leader */
170 null = open("/dev/null", O_RDONLY);
173 if (dup2(null, STDIN_FILENO) < 0)
175 if (dup2(null, STDOUT_FILENO) < 0)
177 if (dup2(null, STDERR_FILENO) < 0)
182 PARA_EMERG_LOG("fatal: %s\n", strerror(errno));
187 * Close the log file of the daemon.
189 void daemon_close_log(void)
193 PARA_INFO_LOG("closing logfile\n");
199 * fopen() the logfile in append mode.
201 * \return Either succeeds or exits.
203 void daemon_open_log_or_die(void)
206 if (!me->logfile_name)
208 me->logfile = fopen(me->logfile_name, "a");
210 PARA_EMERG_LOG("can not open %s: %s\n", me->logfile_name,
214 setlinebuf(me->logfile);
218 * Log the startup message containing the paraslash version.
220 void log_welcome(const char *whoami)
222 PARA_INFO_LOG("welcome to %s " PACKAGE_VERSION " ("BUILD_DATE")\n",
227 * Give up superuser privileges.
229 * \param username The user to switch to.
230 * \param groupname The group to switch to.
232 * This function returns immediately if not invoked with EUID zero. Otherwise,
233 * it tries to obtain the GID of \a groupname and the UID of \a username. On
234 * success, effective and real GID/UID and the saved set-group-ID/set-user-ID
235 * are all set accordingly. On errors, an appropriate message is logged and
236 * exit() is called to terminate the process.
238 * \sa getpwnam(3), getuid(2), setuid(2), getgrnam(2), setgid(2)
240 void drop_privileges_or_die(const char *username, const char *groupname)
248 struct group *g = getgrnam(groupname);
250 PARA_EMERG_LOG("failed to get group %s: %s\n",
251 groupname, strerror(errno));
254 if (setgid(g->gr_gid) < 0) {
255 PARA_EMERG_LOG("failed to set group id %d: %s\n",
256 (int)g->gr_gid, strerror(errno));
261 PARA_EMERG_LOG("root privileges, but no user option given\n");
264 tmp = para_strdup(username);
268 PARA_EMERG_LOG("%s: no such user\n", username);
271 PARA_INFO_LOG("dropping root privileges\n");
272 if (setuid(p->pw_uid) < 0) {
273 PARA_EMERG_LOG("failed to set effective user ID (%s)",
277 PARA_DEBUG_LOG("uid: %d, euid: %d\n", (int)getuid(), (int)geteuid());
281 * Set/get the server uptime.
283 * \param set_or_get Chose one of the two modes.
285 * This should be called at startup time with \a set_or_get equal to \p
286 * UPTIME_SET which sets the uptime to zero. Subsequent calls with \a
287 * set_or_get equal to \p UPTIME_GET return the uptime.
289 * \return Zero if called with \a set_or_get equal to \p UPTIME_SET, the number
290 * of seconds elapsed since the last reset otherwise.
292 * \sa time(2), difftime(3).
294 time_t server_uptime(enum uptime set_or_get)
299 if (set_or_get == UPTIME_SET) {
300 time(&me->startuptime);
304 diff = difftime(now, me->startuptime);
305 return (time_t) diff;
309 * Construct string containing uptime.
311 * \return A dynamically allocated string of the form "days:hours:minutes".
315 __malloc char *uptime_str(void)
317 long t = server_uptime(UPTIME_GET);
318 return make_message("%li:%02li:%02li", t / 86400,
319 (t / 3600) % 24, (t / 60) % 60);
323 * The log function for para_server and para_audiod.
325 * \param ll The log level.
326 * \param fmt The format string describing the log message.
328 __printf_2_3 void para_log(int ll, const char* fmt,...)
336 ll = PARA_MIN(ll, NUM_LOGLEVELS - 1);
337 ll = PARA_MAX(ll, LL_DEBUG);
338 if (ll < me->loglevel)
341 fp = me->logfile? me->logfile : stderr;
342 color = daemon_test_flag(DF_COLOR_LOG)? me->log_colors[ll] : NULL;
344 fprintf(fp, "%s", color);
345 if (daemon_test_flag(DF_LOG_TIME)) { /* print date and time */
349 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
350 fprintf(fp, "%s ", str);
352 if (daemon_test_flag(DF_LOG_HOSTNAME)) {
354 me->hostname = para_hostname();
355 fprintf(fp, "%s ", me->hostname);
357 if (daemon_test_flag(DF_LOG_LL)) /* log loglevel */
358 fprintf(fp, "(%d) ", ll);
359 if (daemon_test_flag(DF_LOG_PID)) { /* log pid */
360 pid_t mypid = getpid();
361 fprintf(fp, "(%d) ", (int)mypid);
364 vfprintf(fp, fmt, argp);
367 fprintf(fp, "%s", COLOR_RESET);