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() */
19 /** The internal state of the daemon. */
21 /** See \ref daemon_flags. */
23 /** Set by \ref daemon_set_logfile(). */
25 /** Current loglevel, see \ref daemon_set_loglevel(). */
28 /** Used by \ref server_uptime() and \ref uptime_str(). */
30 /** The file pointer if the logfile is open. */
32 /** Used by para_log() if \p DF_LOG_HOSTNAME is set. */
34 /** Used for colored log messages. */
35 char log_colors[NUM_LOGLEVELS][COLOR_MAXLEN];
38 static struct daemon the_daemon, *me = &the_daemon;
41 * Activate default log colors.
43 * This should be called early if color support is wanted.
45 void daemon_set_default_log_colors(void)
48 static const char *default_log_colors[NUM_LOGLEVELS] = {
49 [LL_DEBUG] = "normal",
51 [LL_NOTICE] = "normal",
52 [LL_WARNING] = "yellow",
54 [LL_CRIT] = "magenta bold",
55 [LL_EMERG] = "red bold",
57 for (i = 0; i < NUM_LOGLEVELS; i++) {
58 int ret = color_parse(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 int daemon_set_log_color(char const *arg)
74 char *p = strchr(arg, ':');
79 ret = get_loglevel_by_name(arg);
84 ret = color_parse(p, me->log_colors[ll]);
89 PARA_ERROR_LOG("%s: color syntax error\n", arg);
95 * Init or change the name of the log file.
97 * \param logfile_name The full path of the logfile.
99 void daemon_set_logfile(char *logfile_name)
101 free(me->logfile_name);
102 me->logfile_name = NULL;
104 me->logfile_name = para_strdup(logfile_name);
108 * Suppress log messages with severity lower than the given loglevel.
110 * \param loglevel The smallest level that should be logged.
112 void daemon_set_loglevel(char *loglevel)
114 int ret = get_loglevel_by_name(loglevel);
121 * Set one of the daemon config flags.
123 * \param flag The flag to set.
125 * \sa \ref daemon_flags.
127 void daemon_set_flag(unsigned flag)
133 * Clear one of the daemon config flags.
135 * \param flag The flag to clear.
137 * \sa \ref daemon_flags.
139 void daemon_clear_flag(unsigned flag)
144 static unsigned daemon_test_flag(unsigned flag)
146 return me->flags & flag;
150 * Do the usual stuff to become a daemon.
152 * Fork, become session leader, dup fd 0, 1, 2 to /dev/null.
154 * \sa fork(2), setsid(2), dup(2).
161 PARA_INFO_LOG("daemonizing\n");
166 exit(EXIT_SUCCESS); /* parent exits */
167 /* become session leader */
172 null = open("/dev/null", O_RDONLY);
175 if (dup2(null, STDIN_FILENO) < 0)
177 if (dup2(null, STDOUT_FILENO) < 0)
179 if (dup2(null, STDERR_FILENO) < 0)
184 PARA_EMERG_LOG("fatal: %s\n", strerror(errno));
189 * Close the log file of the daemon.
191 void daemon_close_log(void)
195 PARA_INFO_LOG("closing logfile\n");
201 * fopen() the logfile in append mode.
203 * \return Either succeeds or exits.
205 void daemon_open_log_or_die(void)
208 if (!me->logfile_name)
210 me->logfile = fopen(me->logfile_name, "a");
212 PARA_EMERG_LOG("can not open %s: %s\n", me->logfile_name,
216 setlinebuf(me->logfile);
220 * Log the startup message containing the paraslash version.
222 void log_welcome(const char *whoami)
224 PARA_INFO_LOG("welcome to %s " PACKAGE_VERSION " ("BUILD_DATE")\n",
229 * Give up superuser privileges.
231 * \param username The user to switch to.
232 * \param groupname The group to switch to.
234 * This function returns immediately if not invoked with EUID zero. Otherwise,
235 * it tries to obtain the GID of \a groupname and the UID of \a username. On
236 * success, effective and real GID/UID and the saved set-group-ID/set-user-ID
237 * are all set accordingly. On errors, an appropriate message is logged and
238 * exit() is called to terminate the process.
240 * \sa getpwnam(3), getuid(2), setuid(2), getgrnam(2), setgid(2)
242 void drop_privileges_or_die(const char *username, const char *groupname)
250 struct group *g = getgrnam(groupname);
252 PARA_EMERG_LOG("failed to get group %s: %s\n",
253 groupname, strerror(errno));
256 if (setgid(g->gr_gid) < 0) {
257 PARA_EMERG_LOG("failed to set group id %d: %s\n",
258 (int)g->gr_gid, strerror(errno));
263 PARA_EMERG_LOG("root privileges, but no user option given\n");
266 tmp = para_strdup(username);
270 PARA_EMERG_LOG("%s: no such user\n", username);
273 PARA_INFO_LOG("dropping root privileges\n");
274 if (setuid(p->pw_uid) < 0) {
275 PARA_EMERG_LOG("failed to set effective user ID (%s)",
279 PARA_DEBUG_LOG("uid: %d, euid: %d\n", (int)getuid(), (int)geteuid());
283 * Set/get the server uptime.
285 * \param set_or_get Chose one of the two modes.
287 * This should be called at startup time with \a set_or_get equal to \p
288 * UPTIME_SET which sets the uptime to zero. Subsequent calls with \a
289 * set_or_get equal to \p UPTIME_GET return the uptime.
291 * \return Zero if called with \a set_or_get equal to \p UPTIME_SET, the number
292 * of seconds elapsed since the last reset otherwise.
294 * \sa time(2), difftime(3).
296 time_t server_uptime(enum uptime set_or_get)
301 if (set_or_get == UPTIME_SET) {
302 time(&me->startuptime);
306 diff = difftime(now, me->startuptime);
307 return (time_t) diff;
311 * Construct string containing uptime.
313 * \return A dynamically allocated string of the form "days:hours:minutes".
317 __malloc char *uptime_str(void)
319 long t = server_uptime(UPTIME_GET);
320 return make_message("%li:%02li:%02li", t / 86400,
321 (t / 3600) % 24, (t / 60) % 60);
325 * The log function for para_server and para_audiod.
327 * \param ll The log level.
328 * \param fmt The format string describing the log message.
330 __printf_2_3 void para_log(int ll, const char* fmt,...)
338 ll = PARA_MIN(ll, NUM_LOGLEVELS - 1);
339 ll = PARA_MAX(ll, LL_DEBUG);
340 if (ll < me->loglevel)
343 fp = me->logfile? me->logfile : stderr;
344 color = daemon_test_flag(DF_COLOR_LOG)? me->log_colors[ll] : NULL;
346 fprintf(fp, "%s", color);
347 if (daemon_test_flag(DF_LOG_TIME)) { /* print date and time */
351 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
352 fprintf(fp, "%s ", str);
354 if (daemon_test_flag(DF_LOG_HOSTNAME)) {
356 me->hostname = para_hostname();
357 fprintf(fp, "%s ", me->hostname);
359 if (daemon_test_flag(DF_LOG_LL)) /* log loglevel */
360 fprintf(fp, "(%d) ", ll);
361 if (daemon_test_flag(DF_LOG_PID)) { /* log pid */
362 pid_t mypid = getpid();
363 fprintf(fp, "(%d) ", (int)mypid);
366 vfprintf(fp, fmt, argp);
369 fprintf(fp, "%s", COLOR_RESET);