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() */
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(). */
29 /** Used by \ref server_uptime() and \ref uptime_str(). */
31 /** The file pointer if the logfile is open. */
33 /** Used by para_log() if \p DF_LOG_HOSTNAME is set. */
35 /** Used for colored log messages. */
36 char log_colors
[NUM_LOGLEVELS
][COLOR_MAXLEN
];
39 static struct daemon the_daemon
, *me
= &the_daemon
;
42 * Activate default log colors.
44 * This should be called early if color support is wanted.
46 void daemon_set_default_log_colors(void)
49 static const char *default_log_colors
[NUM_LOGLEVELS
] = {
50 [LL_DEBUG
] = "normal",
52 [LL_NOTICE
] = "normal",
53 [LL_WARNING
] = "yellow",
55 [LL_CRIT
] = "magenta bold",
56 [LL_EMERG
] = "red bold",
58 for (i
= 0; i
< NUM_LOGLEVELS
; i
++)
59 color_parse_or_die(default_log_colors
[i
], me
->log_colors
[i
]);
63 * Set the color for one loglevel.
65 * \param arg The loglevel/color specifier.
67 * \a arg must be of the form "ll:[fg [bg]] [attr]".
69 * \return 1 On success, -1 on errors.
71 void daemon_set_log_color_or_die(char const *arg
)
73 char *p
= strchr(arg
, ':');
78 ret
= get_loglevel_by_name(arg
);
83 color_parse_or_die(p
, me
->log_colors
[ll
]);
86 PARA_EMERG_LOG("%s: color syntax error\n", arg
);
91 * Init or change the name of the log file.
93 * \param logfile_name The full path of the logfile.
95 void daemon_set_logfile(char *logfile_name
)
97 free(me
->logfile_name
);
98 me
->logfile_name
= NULL
;
100 me
->logfile_name
= para_strdup(logfile_name
);
104 * Suppress log messages with severity lower than the given loglevel.
106 * \param loglevel The smallest level that should be logged.
108 void daemon_set_loglevel(char *loglevel
)
110 int ret
= get_loglevel_by_name(loglevel
);
117 * Set one of the daemon config flags.
119 * \param flag The flag to set.
121 * \sa \ref daemon_flags.
123 void daemon_set_flag(unsigned flag
)
129 * Clear one of the daemon config flags.
131 * \param flag The flag to clear.
133 * \sa \ref daemon_flags.
135 void daemon_clear_flag(unsigned flag
)
140 static bool daemon_test_flag(unsigned flag
)
142 return me
->flags
& flag
;
146 * Do the usual stuff to become a daemon.
148 * Fork, become session leader, dup fd 0, 1, 2 to /dev/null.
150 * \sa fork(2), setsid(2), dup(2).
157 PARA_INFO_LOG("daemonizing\n");
162 exit(EXIT_SUCCESS
); /* parent exits */
163 /* become session leader */
168 null
= open("/dev/null", O_RDONLY
);
171 if (dup2(null
, STDIN_FILENO
) < 0)
173 if (dup2(null
, STDOUT_FILENO
) < 0)
175 if (dup2(null
, STDERR_FILENO
) < 0)
180 PARA_EMERG_LOG("fatal: %s\n", strerror(errno
));
185 * Close the log file of the daemon.
187 void daemon_close_log(void)
191 PARA_INFO_LOG("closing logfile\n");
197 * fopen() the logfile in append mode.
199 * \return Either succeeds or exits.
201 void daemon_open_log_or_die(void)
204 if (!me
->logfile_name
)
206 me
->logfile
= fopen(me
->logfile_name
, "a");
208 PARA_EMERG_LOG("can not open %s: %s\n", me
->logfile_name
,
212 setlinebuf(me
->logfile
);
216 * Log the startup message containing the paraslash version.
218 void log_welcome(const char *whoami
)
220 PARA_INFO_LOG("welcome to %s " PACKAGE_VERSION
" ("BUILD_DATE
")\n",
225 * Give up superuser privileges.
227 * \param username The user to switch to.
228 * \param groupname The group to switch to.
230 * This function returns immediately if not invoked with EUID zero. Otherwise,
231 * it tries to obtain the GID of \a groupname and the UID of \a username. On
232 * success, effective and real GID/UID and the saved set-group-ID/set-user-ID
233 * are all set accordingly. On errors, an appropriate message is logged and
234 * exit() is called to terminate the process.
236 * \sa getpwnam(3), getuid(2), setuid(2), getgrnam(2), setgid(2)
238 void drop_privileges_or_die(const char *username
, const char *groupname
)
246 struct group
*g
= getgrnam(groupname
);
248 PARA_EMERG_LOG("failed to get group %s: %s\n",
249 groupname
, strerror(errno
));
252 if (setgid(g
->gr_gid
) < 0) {
253 PARA_EMERG_LOG("failed to set group id %d: %s\n",
254 (int)g
->gr_gid
, strerror(errno
));
259 PARA_EMERG_LOG("root privileges, but no user option given\n");
262 tmp
= para_strdup(username
);
266 PARA_EMERG_LOG("%s: no such user\n", username
);
269 PARA_INFO_LOG("dropping root privileges\n");
270 if (setuid(p
->pw_uid
) < 0) {
271 PARA_EMERG_LOG("failed to set effective user ID (%s)",
275 PARA_DEBUG_LOG("uid: %d, euid: %d\n", (int)getuid(), (int)geteuid());
279 * Set the server startup time.
281 * \param startuptime The value to store as the server start time.
283 * This should be called once on startup with \a startuptime either NULL or a
284 * pointer to a struct timeval which contains the current time. If \a
285 * startuptime is NULL, the server start time is set to the current time.
287 * \sa time(2), difftime(3) \ref get_server_uptime(), \ref
288 * get_server_uptime_str().
290 void set_server_start_time(const struct timeval
*startuptime
)
293 me
->startuptime
= startuptime
->tv_sec
;
295 time(&me
->startuptime
);
299 * Get the server uptime.
301 * \param current_time The current time.
303 * The \a current_time pointer may be \p NULL. In this case the function
304 * obtains the current time from the system.
306 * \return This returns the server uptime in seconds, i.e. the difference
307 * between the current time and the value stored previously via \ref
308 * set_server_start_time().
310 time_t get_server_uptime(const struct timeval
*current_time
)
315 return current_time
->tv_sec
- me
->startuptime
;
317 return difftime(t
, me
->startuptime
);
321 * Construct a string containing the current uptime.
323 * \param current_time See a \ref get_server_uptime().
325 * \return A dynamically allocated string of the form "days:hours:minutes".
329 __malloc
char *get_server_uptime_str(const struct timeval
*current_time
)
331 long t
= get_server_uptime(current_time
);
332 return make_message("%li:%02li:%02li", t
/ 86400,
333 (t
/ 3600) % 24, (t
/ 60) % 60);
337 * The log function for para_server and para_audiod.
339 * \param ll The log level.
340 * \param fmt The format string describing the log message.
342 __printf_2_3
void para_log(int ll
, const char* fmt
,...)
348 bool log_time
= daemon_test_flag(DF_LOG_TIME
), log_timing
=
349 daemon_test_flag(DF_LOG_TIMING
);
351 ll
= PARA_MIN(ll
, NUM_LOGLEVELS
- 1);
352 ll
= PARA_MAX(ll
, LL_DEBUG
);
353 if (ll
< me
->loglevel
)
356 fp
= me
->logfile
? me
->logfile
: stderr
;
357 color
= daemon_test_flag(DF_COLOR_LOG
)? me
->log_colors
[ll
] : NULL
;
359 fprintf(fp
, "%s", color
);
360 if (log_time
|| log_timing
) {
362 gettimeofday(&tv
, NULL
);
363 if (daemon_test_flag(DF_LOG_TIME
)) { /* print date and time */
364 time_t t1
= tv
.tv_sec
;
367 strftime(str
, sizeof(str
), "%b %d %H:%M:%S", tm
);
368 fprintf(fp
, "%s%s", str
, log_timing
? ":" : " ");
370 if (log_timing
) /* print milliseconds */
371 fprintf(fp
, "%04lu ", (long unsigned)tv
.tv_usec
/ 1000);
373 if (daemon_test_flag(DF_LOG_HOSTNAME
)) {
375 me
->hostname
= para_hostname();
376 fprintf(fp
, "%s ", me
->hostname
);
378 if (daemon_test_flag(DF_LOG_LL
)) /* log loglevel */
379 fprintf(fp
, "(%d) ", ll
);
380 if (daemon_test_flag(DF_LOG_PID
)) { /* log pid */
381 pid_t mypid
= getpid();
382 fprintf(fp
, "(%d) ", (int)mypid
);
385 vfprintf(fp
, fmt
, argp
);
388 fprintf(fp
, "%s", COLOR_RESET
);