-/*
- * Copyright (C) 1997-2008 Andre Noll <maan@systemlinux.org>
- *
- * Licensed under the GPL v2. For licencing details see COPYING.
- */
+/* Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
/** \file daemon.c Some helpers for programs that detach from the console. */
-#include "para.h"
-#include "daemon.h"
-#include <pwd.h>
-/* getgrnam() */
-#include <sys/types.h>
+#include <regex.h>
+#include <pwd.h>
+#include <sys/types.h> /* getgrnam() */
#include <grp.h>
+#include <signal.h>
+#include <sys/resource.h>
+#include "para.h"
+#include "daemon.h"
#include "string.h"
+#include "color.h"
+
+/** The internal state of the daemon. */
+struct daemon {
+ /** See \ref daemon_flags. */
+ unsigned flags;
+ /** Set by \ref daemon_set_logfile(). */
+ char *logfile_name;
+ /** Current loglevel, see \ref daemon_set_loglevel(). */
+ int loglevel;
+ /** Used by \ref server_uptime() and \ref uptime_str(). */
+ time_t startuptime;
+ /** The file pointer if the logfile is open. */
+ FILE *logfile;
+ /** Used by para_log() if \p DF_LOG_HOSTNAME is set. */
+ char *hostname;
+ /** Used for colored log messages. */
+ char log_colors[NUM_LOGLEVELS][COLOR_MAXLEN];
+ char *old_cwd;
+ /*
+ * If these pointers are non-NULL, the functions are called from
+ * daemon_log() before and after writing each log message.
+ */
+ void (*pre_log_hook)(void);
+ void (*post_log_hook)(void);
+};
+
+static struct daemon the_daemon, *me = &the_daemon;
+
+static void daemon_set_default_log_colors(void)
+{
+ int i;
+ static const char *default_log_colors[NUM_LOGLEVELS] = {
+ [LL_DEBUG] = "normal",
+ [LL_INFO] = "normal",
+ [LL_NOTICE] = "normal",
+ [LL_WARNING] = "yellow",
+ [LL_ERROR] = "red",
+ [LL_CRIT] = "magenta bold",
+ [LL_EMERG] = "red bold",
+ };
+ for (i = 0; i < NUM_LOGLEVELS; i++)
+ color_parse_or_die(default_log_colors[i], me->log_colors[i]);
+}
+
+/**
+ * Set the color for one loglevel.
+ *
+ * \param arg Must be of the form "ll:[fg [bg]] [attr]".
+ */
+void daemon_set_log_color_or_die(const char *arg)
+{
+ char *p = strchr(arg, ':');
+ int ret, ll;
+
+ if (!p)
+ goto err;
+ ret = get_loglevel_by_name(arg);
+ if (ret < 0)
+ goto err;
+ ll = ret;
+ p++;
+ color_parse_or_die(p, me->log_colors[ll]);
+ return;
+err:
+ PARA_EMERG_LOG("%s: invalid color argument\n", arg);
+ exit(EXIT_FAILURE);
+}
+
+/**
+ * Initialize color mode if necessary.
+ *
+ * \param color_arg The argument given to --color.
+ * \param color_arg_auto The value for automatic color detection.
+ * \param color_arg_no The value to disable colored log messages.
+ * \param logfile_given In auto mode colors are disabled if this value is true.
+ *
+ * If color_arg equals color_arg_no, color mode is disabled. That is, calls to
+ * para_log() will not produce colored output. If color_arg equals
+ * color_arg_auto, the function detects automatically whether to activate
+ * colors. Otherwise color mode is enabled.
+ *
+ * If color mode is to be enabled, the default colors are set for each
+ * loglevel. They can be overwritten by calling daemon_set_log_color_or_die().
+ *
+ * \return Whether colors have been enabled by the function.
+ */
+bool daemon_init_colors_or_die(int color_arg, int color_arg_auto,
+ int color_arg_no, bool logfile_given)
+{
+ if (color_arg == color_arg_no)
+ return false;
+ if (color_arg == color_arg_auto) {
+ if (logfile_given)
+ return false;
+ if (!isatty(STDERR_FILENO))
+ return false;
+ }
+ daemon_set_flag(DF_COLOR_LOG);
+ daemon_set_default_log_colors();
+ return true;
+}
+
+/**
+ * Init or change the name of the log file.
+ *
+ * \param logfile_name The full path of the logfile.
+ */
+void daemon_set_logfile(const char *logfile_name)
+{
+ free(me->logfile_name);
+ me->logfile_name = NULL;
+ if (!logfile_name)
+ return;
+ if (me->old_cwd && logfile_name[0] != '/')
+ me->logfile_name = make_message("%s/%s", me->old_cwd,
+ logfile_name);
+ else
+ me->logfile_name = para_strdup(logfile_name);
+}
+
+/**
+ * Suppress log messages with severity lower than the given loglevel.
+ *
+ * \param loglevel The smallest level that should be logged.
+ */
+void daemon_set_loglevel(const char *loglevel)
+{
+ int ret = get_loglevel_by_name(loglevel);
+
+ assert(ret >= 0);
+ me->loglevel = ret;
+}
+
+/**
+ * Register functions to be called before and after a message is logged.
+ *
+ * \param pre_log_hook Called before the message is logged.
+ * \param post_log_hook Called after the message is logged.
+ *
+ * The purpose of this function is to provide a primitive for multi-threaded
+ * applications to serialize the access to the log facility, preventing
+ * interleaving log messages. This can be achieved by having the pre-log hook
+ * acquire a lock which blocks the other threads on the attempt to log a
+ * message at the same time. The post-log hook is responsible for releasing
+ * the lock.
+ *
+ * If these hooks are unnecessary, for example because the application is
+ * single-threaded, this function does not need to be called.
+ */
+void daemon_set_hooks(void (*pre_log_hook)(void), void (*post_log_hook)(void))
+{
+ me->pre_log_hook = pre_log_hook;
+ me->post_log_hook = post_log_hook;
+}
+
+/**
+ * Set one of the daemon config flags.
+ *
+ * \param flag The flag to set.
+ *
+ * \sa \ref daemon_flags.
+ */
+void daemon_set_flag(unsigned flag)
+{
+ me->flags |= flag;
+}
+
+static bool daemon_test_flag(unsigned flag)
+{
+ return me->flags & flag;
+}
/**
* Do the usual stuff to become a daemon.
*
- * Fork, become session leader, dup fd 0, 1, 2 to /dev/null.
+ * \param parent_waits Whether the parent process should pause before exit.
+ *
+ * Fork, become session leader, cd to /, and dup fd 0, 1, 2 to /dev/null. If \a
+ * parent_waits is false, the parent process terminates immediately.
+ * Otherwise, a pipe is created prior to the fork() and the parent tries to
+ * read a single byte from the reading end of the pipe. The child is supposed
+ * to write to the writing end of the pipe after it completed its setup
+ * procedure successfully. This behaviour is useful to let the parent process
+ * die with an error if the child process aborts early, since in this case the
+ * read() will return non-positive.
*
- * \sa fork(2), setsid(2), dup(2).
+ * \return This function either succeeds or calls exit(3). If parent_waits is
+ * true, the return value is the file descriptor of the writing end of the
+ * pipe. Otherwise the function returns zero.
+ *
+ * \sa fork(2), setsid(2), dup(2), pause(2).
*/
-void daemon_init(void)
+int daemonize(bool parent_waits)
{
pid_t pid;
- int null;
+ int null, pipe_fd[2];
- PARA_INFO_LOG("daemonizing\n");
+ if (parent_waits && pipe(pipe_fd) < 0)
+ goto err;
+ PARA_INFO_LOG("subsequent log messages go to %s\n", me->logfile_name?
+ me->logfile_name : "/dev/null");
pid = fork();
if (pid < 0)
goto err;
- if (pid)
- exit(EXIT_SUCCESS); /* parent exits */
+ if (pid) { /* parent exits */
+ if (parent_waits) {
+ char c;
+ close(pipe_fd[1]);
+ exit(read(pipe_fd[0], &c, 1) <= 0?
+ EXIT_FAILURE : EXIT_SUCCESS);
+ }
+ exit(EXIT_SUCCESS);
+ }
+ if (parent_waits)
+ close(pipe_fd[0]);
/* become session leader */
if (setsid() < 0)
goto err;
+ me->old_cwd = getcwd(NULL, 0);
if (chdir("/") < 0)
goto err;
- umask(0);
- null = open("/dev/null", O_RDONLY);
+ null = open("/dev/null", O_RDWR);
if (null < 0)
goto err;
if (dup2(null, STDIN_FILENO) < 0)
if (dup2(null, STDERR_FILENO) < 0)
goto err;
close(null);
- return;
+ return parent_waits? pipe_fd[1] : 0;
err:
PARA_EMERG_LOG("fatal: %s\n", strerror(errno));
exit(EXIT_FAILURE);
}
/**
- * fopen() the given file in append mode.
- *
- * \param logfile_name The name of the file to open.
+ * Close the log file of the daemon.
+ */
+void daemon_close_log(void)
+{
+ if (!me->logfile)
+ return;
+ PARA_INFO_LOG("closing logfile\n");
+ fclose(me->logfile);
+ me->logfile = NULL;
+}
+
+/**
+ * fopen() the logfile in append mode.
*
- * \return Either calls exit() or returns a valid file handle.
+ * \return Either succeeds or exits.
*/
-FILE *open_log(const char *logfile_name)
+void daemon_open_log_or_die(void)
{
- FILE *logfile;
+ FILE *new_log;
- assert(logfile_name);
- logfile = fopen(logfile_name, "a");
- if (!logfile) {
- PARA_EMERG_LOG("can not open %s: %s\n", logfile_name,
+ if (!me->logfile_name)
+ return;
+ new_log = fopen(me->logfile_name, "a");
+ if (!new_log) {
+ PARA_EMERG_LOG("can not open %s: %s\n", me->logfile_name,
strerror(errno));
exit(EXIT_FAILURE);
}
- setlinebuf(logfile);
- return logfile;
+ daemon_close_log();
+ me->logfile = new_log;
+ /* equivalent to setlinebuf(), but portable */
+ setvbuf(me->logfile, NULL, _IOLBF, 0);
}
/**
- * Close the log file of the daemon.
+ * Log the startup message containing the paraslash version.
*
- * \param logfile The log file handle.
+ * \param name The name of the executable.
*
- * It's OK to call this with logfile == \p NULL.
+ * First the given \a name is prefixed with the string "para_". Next the git
+ * version is appended. The resulting string is logged with priority "INFO".
*/
-void close_log(FILE* logfile)
+void daemon_log_welcome(const char *name)
{
- if (!logfile)
- return;
- PARA_INFO_LOG("closing logfile\n");
- fclose(logfile);
+ PARA_INFO_LOG("welcome to para_%s-" PACKAGE_VERSION " \n", name);
}
/**
- * Log the startup message containing the paraslash version.
+ * Renice the calling process.
+ *
+ * \param prio The priority value to set.
+ *
+ * Errors are not considered fatal, but a warning message is logged if the
+ * underlying call to setpriority(2) fails.
*/
-void log_welcome(const char *whoami, int loglevel)
+void daemon_set_priority(int prio)
{
- PARA_INFO_LOG("welcome to %s " PACKAGE_VERSION " ("BUILD_DATE")\n",
- whoami);
- PARA_DEBUG_LOG("using loglevel %d\n", loglevel);
+ if (setpriority(PRIO_PROCESS, 0, prio) < 0)
+ PARA_WARNING_LOG("could not set priority to %d: %s\n", prio,
+ strerror(errno));
}
/**
*
* \sa getpwnam(3), getuid(2), setuid(2), getgrnam(2), setgid(2)
*/
-void para_drop_privileges(const char *username, const char *groupname)
+void daemon_drop_privileges_or_die(const char *username, const char *groupname)
{
struct passwd *p;
char *tmp;
exit(EXIT_FAILURE);
}
PARA_INFO_LOG("dropping root privileges\n");
- setuid(p->pw_uid);
+ if (setuid(p->pw_uid) < 0) {
+ PARA_EMERG_LOG("failed to set effective user ID (%s)",
+ strerror(errno));
+ exit(EXIT_FAILURE);
+ }
PARA_DEBUG_LOG("uid: %d, euid: %d\n", (int)getuid(), (int)geteuid());
}
/**
- * Set/get the server uptime.
+ * Set the startup time.
*
- * \param set_or_get Chose one of the two modes.
+ * This should be called once on startup. It sets the start time to the
+ * current time. The stored time is used for retrieving the server uptime.
*
- * This should be called at startup time with \a set_or_get equal to \p
- * UPTIME_SET which sets the uptime to zero. Subsequent calls with \a
- * set_or_get equal to \p UPTIME_GET return the uptime.
+ * \sa time(2), \ref daemon_get_uptime(), \ref daemon_get_uptime_str().
+ */
+void daemon_set_start_time(void)
+{
+ time(&me->startuptime);
+}
- * \return Zero if called with \a set_or_get equal to \p UPTIME_SET, the number
- * of seconds ellapsed since the last reset otherwise.
+/**
+ * Get the uptime.
+ *
+ * \param current_time The current time.
*
- * \sa time(2), difftime(3).
+ * The \a current_time pointer may be \p NULL. In this case the function
+ * obtains the current time from the system.
+ *
+ * \return This returns the server uptime in seconds, i.e. the difference
+ * between the current time and the value stored previously via \ref
+ * daemon_set_start_time().
*/
-time_t server_uptime(enum uptime set_or_get)
+time_t daemon_get_uptime(const struct timeval *current_time)
{
- static time_t startuptime;
- time_t now;
- double diff;
+ time_t t;
- if (set_or_get == UPTIME_SET) {
- time(&startuptime);
- return 0;
- }
- time(&now);
- diff = difftime(now, startuptime);
- return (time_t) diff;
+ if (current_time)
+ return current_time->tv_sec - me->startuptime;
+ time(&t);
+ return difftime(t, me->startuptime);
}
/**
- * Construct string containing uptime.
+ * Construct a string containing the current uptime.
*
- * \return A dynamically allocated string of the form "days:hours:minutes".
+ * \param current_time See a \ref daemon_get_uptime().
*
- * \sa server_uptime.
+ * \return A dynamically allocated string of the form "days:hours:minutes".
*/
-__malloc char *uptime_str(void)
+__malloc char *daemon_get_uptime_str(const struct timeval *current_time)
{
- long t = server_uptime(UPTIME_GET);
+ long t = daemon_get_uptime(current_time);
return make_message("%li:%02li:%02li", t / 86400,
(t / 3600) % 24, (t / 60) % 60);
}
+
+/**
+ * The log function for para_server and para_audiod.
+ *
+ * \param ll The log level.
+ * \param fmt The format string describing the log message.
+ */
+__printf_2_3 void daemon_log(int ll, const char* fmt,...)
+{
+ va_list argp;
+ FILE *fp;
+ struct tm *tm;
+ char *color;
+ bool log_time = daemon_test_flag(DF_LOG_TIME), log_timing =
+ daemon_test_flag(DF_LOG_TIMING);
+
+ ll = PARA_MIN(ll, NUM_LOGLEVELS - 1);
+ ll = PARA_MAX(ll, LL_DEBUG);
+ if (ll < me->loglevel)
+ return;
+
+ fp = me->logfile? me->logfile : stderr;
+ if (me->pre_log_hook)
+ me->pre_log_hook();
+ color = daemon_test_flag(DF_COLOR_LOG)? me->log_colors[ll] : NULL;
+ if (color)
+ fprintf(fp, "%s", color);
+ if (log_time || log_timing) {
+ struct timeval tv;
+ clock_get_realtime(&tv);
+ if (daemon_test_flag(DF_LOG_TIME)) { /* print date and time */
+ time_t t1 = tv.tv_sec;
+ char str[100];
+ tm = localtime(&t1);
+ strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
+ fprintf(fp, "%s%s", str, log_timing? ":" : " ");
+ }
+ if (log_timing) /* print milliseconds */
+ fprintf(fp, "%04lu ", (long unsigned)tv.tv_usec / 1000);
+ }
+ if (daemon_test_flag(DF_LOG_HOSTNAME)) {
+ if (!me->hostname)
+ me->hostname = para_hostname();
+ fprintf(fp, "%s ", me->hostname);
+ }
+ if (daemon_test_flag(DF_LOG_LL)) /* log loglevel */
+ fprintf(fp, "(%d) ", ll);
+ if (daemon_test_flag(DF_LOG_PID)) { /* log pid */
+ pid_t mypid = getpid();
+ fprintf(fp, "(%d) ", (int)mypid);
+ }
+ va_start(argp, fmt);
+ vfprintf(fp, fmt, argp);
+ va_end(argp);
+ if (color)
+ fprintf(fp, "%s", COLOR_RESET);
+ if (me->post_log_hook)
+ me->post_log_hook();
+}
projects / paraslash.git / blobdiff