X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=daemon.c;h=20cdc6ae605a99f56f35bf41f0abeff7d508936d;hp=b7a0a3267b68df5b020159f90c56337073463244;hb=0b6e7a20c19d642f9d8e65683e1525c91dd3de39;hpb=65542c43361ce4168f185b4c05835f5f5d09a043 diff --git a/daemon.c b/daemon.c index b7a0a326..20cdc6ae 100644 --- a/daemon.c +++ b/daemon.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 1997-2011 Andre Noll + * Copyright (C) 1997 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ @@ -10,8 +10,8 @@ #include #include /* getgrnam() */ #include -#include -#include +#include +#include #include "para.h" #include "daemon.h" @@ -26,7 +26,6 @@ struct daemon { 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. */ @@ -39,12 +38,7 @@ struct daemon { static struct daemon the_daemon, *me = &the_daemon; -/** - * Activate default log colors. - * - * This should be called early if color support is wanted. - */ -void daemon_set_default_log_colors(void) +static void daemon_set_default_log_colors(void) { int i; static const char *default_log_colors[NUM_LOGLEVELS] = { @@ -63,13 +57,9 @@ void daemon_set_default_log_colors(void) /** * Set the color for one loglevel. * - * \param arg The loglevel/color specifier. - * - * \a arg must be of the form "ll:[fg [bg]] [attr]". - * - * \return 1 On success, -1 on errors. + * \param arg Must be of the form "ll:[fg [bg]] [attr]". */ -void daemon_set_log_color_or_die(char const *arg) +void daemon_set_log_color_or_die(const char *arg) { char *p = strchr(arg, ':'); int ret, ll; @@ -84,16 +74,50 @@ void daemon_set_log_color_or_die(char const *arg) color_parse_or_die(p, me->log_colors[ll]); return; err: - PARA_EMERG_LOG("%s: color syntax error\n", arg); + 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(char *logfile_name) +void daemon_set_logfile(const char *logfile_name) { free(me->logfile_name); me->logfile_name = NULL; @@ -106,7 +130,7 @@ void daemon_set_logfile(char *logfile_name) * * \param loglevel The smallest level that should be logged. */ -void daemon_set_loglevel(char *loglevel) +void daemon_set_loglevel(const char *loglevel) { int ret = get_loglevel_by_name(loglevel); @@ -126,18 +150,6 @@ void daemon_set_flag(unsigned flag) me->flags |= flag; } -/** - * Clear one of the daemon config flags. - * - * \param flag The flag to clear. - * - * \sa \ref daemon_flags. - */ -void daemon_clear_flag(unsigned flag) -{ - me->flags &= ~flag; -} - static bool daemon_test_flag(unsigned flag) { return me->flags & flag; @@ -146,27 +158,52 @@ static bool daemon_test_flag(unsigned 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. * - * \sa fork(2), setsid(2), dup(2). + * 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. + * + * \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 daemonize(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; if (chdir("/") < 0) goto err; - null = open("/dev/null", O_RDONLY); + null = open("/dev/null", O_RDWR); if (null < 0) goto err; if (dup2(null, STDIN_FILENO) < 0) @@ -176,7 +213,7 @@ void daemonize(void) 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); @@ -210,16 +247,36 @@ void daemon_open_log_or_die(void) strerror(errno)); exit(EXIT_FAILURE); } - setlinebuf(me->logfile); + /* equivalent to setlinebuf(), but portable */ + setvbuf(me->logfile, NULL, _IOLBF, 0); } /** * Log the startup message containing the paraslash version. + * + * \param name The name of the executable. + * + * 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 daemon_log_welcome(const char *name) +{ + PARA_INFO_LOG("welcome to para_%s-" PACKAGE_VERSION " \n", name); +} + +/** + * 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) +void daemon_set_priority(int prio) { - PARA_INFO_LOG("welcome to %s " PACKAGE_VERSION " ("BUILD_DATE")\n", - whoami); + if (setpriority(PRIO_PROCESS, 0, prio) < 0) + PARA_WARNING_LOG("could not set priority to %d: %s\n", prio, + strerror(errno)); } /** @@ -236,7 +293,7 @@ void log_welcome(const char *whoami) * * \sa getpwnam(3), getuid(2), setuid(2), getgrnam(2), setgid(2) */ -void drop_privileges_or_die(const char *username, const char *groupname) +void daemon_drop_privileges_or_die(const char *username, const char *groupname) { struct passwd *p; char *tmp; @@ -277,43 +334,52 @@ void drop_privileges_or_die(const char *username, const char *groupname) } /** - * 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 elapsed 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) { - time_t now; - double diff; + time_t t; - if (set_or_get == UPTIME_SET) { - time(&me->startuptime); - return 0; - } - time(&now); - diff = difftime(now, me->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. + * + * \param current_time See a \ref daemon_get_uptime(). * * \return A dynamically allocated string of the form "days:hours:minutes". * * \sa server_uptime. */ -__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); } @@ -324,7 +390,7 @@ __malloc char *uptime_str(void) * \param ll The log level. * \param fmt The format string describing the log message. */ -__printf_2_3 void para_log(int ll, const char* fmt,...) +__printf_2_3 void daemon_log(int ll, const char* fmt,...) { va_list argp; FILE *fp; @@ -344,7 +410,7 @@ __printf_2_3 void para_log(int ll, const char* fmt,...) fprintf(fp, "%s", color); if (log_time || log_timing) { struct timeval tv; - gettimeofday(&tv, NULL); + clock_get_realtime(&tv); if (daemon_test_flag(DF_LOG_TIME)) { /* print date and time */ time_t t1 = tv.tv_sec; char str[100];