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() */
21 /** The internal state of the daemon. */
23 /** See \ref daemon_flags. */
25 /** Set by \ref daemon_set_logfile(). */
27 /** 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 int ret = color_parse(default_log_colors[i], me->log_colors[i]);
66 * Set the color for one loglevel.
68 * \param arg The loglevel/color specifier.
70 * \a arg must be of the form "ll:[fg [bg]] [attr]".
72 * \return 1 On success, -1 on errors.
74 int daemon_set_log_color(char const *arg)
76 char *p = strchr(arg, ':');
81 ret = get_loglevel_by_name(arg);
86 ret = color_parse(p, me->log_colors[ll]);
91 PARA_ERROR_LOG("%s: color syntax error\n", arg);
97 * Init or change the name of the log file.
99 * \param logfile_name The full path of the logfile.
101 void daemon_set_logfile(char *logfile_name)
103 free(me->logfile_name);
104 me->logfile_name = NULL;
106 me->logfile_name = para_strdup(logfile_name);
110 * Suppress log messages with severity lower than the given loglevel.
112 * \param loglevel The smallest level that should be logged.
114 void daemon_set_loglevel(char *loglevel)
116 int ret = get_loglevel_by_name(loglevel);
123 * Set one of the daemon config flags.
125 * \param flag The flag to set.
127 * \sa \ref daemon_flags.
129 void daemon_set_flag(unsigned flag)
135 * Clear one of the daemon config flags.
137 * \param flag The flag to clear.
139 * \sa \ref daemon_flags.
141 void daemon_clear_flag(unsigned flag)
146 static bool daemon_test_flag(unsigned flag)
148 return me->flags & flag;
152 * Do the usual stuff to become a daemon.
154 * Fork, become session leader, dup fd 0, 1, 2 to /dev/null.
156 * \sa fork(2), setsid(2), dup(2).
163 PARA_INFO_LOG("daemonizing\n");
168 exit(EXIT_SUCCESS); /* parent exits */
169 /* become session leader */
174 null = open("/dev/null", O_RDONLY);
177 if (dup2(null, STDIN_FILENO) < 0)
179 if (dup2(null, STDOUT_FILENO) < 0)
181 if (dup2(null, STDERR_FILENO) < 0)
186 PARA_EMERG_LOG("fatal: %s\n", strerror(errno));
191 * Close the log file of the daemon.
193 void daemon_close_log(void)
197 PARA_INFO_LOG("closing logfile\n");
203 * fopen() the logfile in append mode.
205 * \return Either succeeds or exits.
207 void daemon_open_log_or_die(void)
210 if (!me->logfile_name)
212 me->logfile = fopen(me->logfile_name, "a");
214 PARA_EMERG_LOG("can not open %s: %s\n", me->logfile_name,
218 setlinebuf(me->logfile);
222 * Log the startup message containing the paraslash version.
224 void log_welcome(const char *whoami)
226 PARA_INFO_LOG("welcome to %s " PACKAGE_VERSION " ("BUILD_DATE")\n",
231 * Give up superuser privileges.
233 * \param username The user to switch to.
234 * \param groupname The group to switch to.
236 * This function returns immediately if not invoked with EUID zero. Otherwise,
237 * it tries to obtain the GID of \a groupname and the UID of \a username. On
238 * success, effective and real GID/UID and the saved set-group-ID/set-user-ID
239 * are all set accordingly. On errors, an appropriate message is logged and
240 * exit() is called to terminate the process.
242 * \sa getpwnam(3), getuid(2), setuid(2), getgrnam(2), setgid(2)
244 void drop_privileges_or_die(const char *username, const char *groupname)
252 struct group *g = getgrnam(groupname);
254 PARA_EMERG_LOG("failed to get group %s: %s\n",
255 groupname, strerror(errno));
258 if (setgid(g->gr_gid) < 0) {
259 PARA_EMERG_LOG("failed to set group id %d: %s\n",
260 (int)g->gr_gid, strerror(errno));
265 PARA_EMERG_LOG("root privileges, but no user option given\n");
268 tmp = para_strdup(username);
272 PARA_EMERG_LOG("%s: no such user\n", username);
275 PARA_INFO_LOG("dropping root privileges\n");
276 if (setuid(p->pw_uid) < 0) {
277 PARA_EMERG_LOG("failed to set effective user ID (%s)",
281 PARA_DEBUG_LOG("uid: %d, euid: %d\n", (int)getuid(), (int)geteuid());
285 * Set/get the server uptime.
287 * \param set_or_get Chose one of the two modes.
289 * This should be called at startup time with \a set_or_get equal to \p
290 * UPTIME_SET which sets the uptime to zero. Subsequent calls with \a
291 * set_or_get equal to \p UPTIME_GET return the uptime.
293 * \return Zero if called with \a set_or_get equal to \p UPTIME_SET, the number
294 * of seconds elapsed since the last reset otherwise.
296 * \sa time(2), difftime(3).
298 time_t server_uptime(enum uptime set_or_get)
303 if (set_or_get == UPTIME_SET) {
304 time(&me->startuptime);
308 diff = difftime(now, me->startuptime);
309 return (time_t) diff;
313 * Construct string containing uptime.
315 * \return A dynamically allocated string of the form "days:hours:minutes".
319 __malloc char *uptime_str(void)
321 long t = server_uptime(UPTIME_GET);
322 return make_message("%li:%02li:%02li", t / 86400,
323 (t / 3600) % 24, (t / 60) % 60);
327 * The log function for para_server and para_audiod.
329 * \param ll The log level.
330 * \param fmt The format string describing the log message.
332 __printf_2_3 void para_log(int ll, const char* fmt,...)
338 bool log_time = daemon_test_flag(DF_LOG_TIME), log_timing =
339 daemon_test_flag(DF_LOG_TIMING);
341 ll = PARA_MIN(ll, NUM_LOGLEVELS - 1);
342 ll = PARA_MAX(ll, LL_DEBUG);
343 if (ll < me->loglevel)
346 fp = me->logfile? me->logfile : stderr;
347 color = daemon_test_flag(DF_COLOR_LOG)? me->log_colors[ll] : NULL;
349 fprintf(fp, "%s", color);
350 if (log_time || log_timing) {
352 gettimeofday(&tv, NULL);
353 if (daemon_test_flag(DF_LOG_TIME)) { /* print date and time */
354 time_t t1 = tv.tv_sec;
357 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
358 fprintf(fp, "%s%s", str, log_timing? ":" : " ");
360 if (log_timing) /* print milliseconds */
361 fprintf(fp, "%04lu ", (long unsigned)tv.tv_usec / 1000);
363 if (daemon_test_flag(DF_LOG_HOSTNAME)) {
365 me->hostname = para_hostname();
366 fprintf(fp, "%s ", me->hostname);
368 if (daemon_test_flag(DF_LOG_LL)) /* log loglevel */
369 fprintf(fp, "(%d) ", ll);
370 if (daemon_test_flag(DF_LOG_PID)) { /* log pid */
371 pid_t mypid = getpid();
372 fprintf(fp, "(%d) ", (int)mypid);
375 vfprintf(fp, fmt, argp);
378 fprintf(fp, "%s", COLOR_RESET);