- Modified forking. Child will now signal parent when it has started up OK. Only after that (or error) parent dies.

- Modified startup order of LCDd parts.
- Moved code for starting up the socket from main.c to sock.c
- Variable daemon_mode renamed to foreground_mode, consistent with command line.
- Variable lcd_port renamed to bind_port.
- Modified the constant stay_in_foreground for drivers hd44780 and sed1330. They don't need to stay in foreground anymore.

server/drivers/hd44780.c

@@ -111,7 +111,7 @@ static int parse_span_list (int *spanListArray[], int *spLsize, int *dispOffsets
 
 // Vars for the server core
 MODULE_EXPORT char * api_version = API_VERSION;
-MODULE_EXPORT int stay_in_foreground = 1; // because of port access problems
+MODULE_EXPORT int stay_in_foreground = 0;
 MODULE_EXPORT int supports_multiple = 1; // yes, we have no global variables (except for constants)
 MODULE_EXPORT char *symbol_prefix = "HD44780_";
 

server/drivers/sed1330.c

@@ -294,7 +294,7 @@ static char *defaultKeyMapMatrix[KEYPAD_MAXY][KEYPAD_MAXX] = {
 
 // Vars for the server core
 MODULE_EXPORT char * api_version = API_VERSION;
-MODULE_EXPORT int stay_in_foreground = 1;
+MODULE_EXPORT int stay_in_foreground = 0;
 MODULE_EXPORT int supports_multiple = 1; // yes, we have no global variables (except for constants)
 MODULE_EXPORT char *symbol_prefix = "sed1330_";
 

server/main.c

@@ -37,6 +37,8 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <fcntl.h>
+#include <sys/types.h>
+#include <sys/wait.h>
 
 #ifdef HAVE_SYS_TIME_H
 # include <sys/time.h>
@@ -69,7 +71,7 @@ extern int optind, optopt, opterr;
 #define DEFAULT_DRIVER "curses"
 #define DEFAULT_DRIVER_PATH
 #define MAX_DRIVERS 8
-#define DEFAULT_DAEMON_MODE 1
+#define DEFAULT_FOREGROUND_MODE 0
 #define DEFAULT_ROTATE_SERVER_SCREEN 1
 #define DEFAULT_REPORTTOSYSLOG 0
 #define DEFAULT_REPORTLEVEL RPT_WARNING
@@ -97,21 +99,19 @@ char *build_date = __DATE__;
 /* Some variables are settable on the command line. This are variables that
  * change the mode of operation. This includes settings that you can use to
  * enable debugging: driver selection, report settings, bind address etc.
+ * These variables should be in main.h and main.c (below).
+ *
  * All other settings do not need to be settable from the command line. They
  * also do not necesarily need to be read in main.c but can better be read in
  * in the file concerned.
  */
 
-/* All variables are set to 'unset' values*/
+unsigned int bind_port = UNSET_INT;
-#define UNSET_INT -1
-#define UNSET_STR "\01"
-
-int lcd_port = UNSET_INT;
 char bind_addr[64];	/* Do not preinit these strings as they will occupy */
 char configfile[256];	/* a lot of space in the executable. */
 char user[64];		/* The values will be overwritten anyway... */
 
-int daemon_mode = UNSET_INT;
+int foreground_mode = UNSET_INT;
 
 static int report_level = UNSET_INT;
 static int report_to_syslog = UNSET_INT;
@@ -119,10 +119,15 @@ static int report_to_syslog = UNSET_INT;
 /* The drivers and their driver parameters */
 char *drivernames[MAX_DRIVERS];
 int num_drivers = 0;
+
+/* End of configuration variables */
+
+/* Local variables */
 int stored_argc;
 char **stored_argv;
 short got_reload_signal = 0;
 
+/* Local exported variables */
 long int timer = 0;
 
 /**** Local functions ****/
@@ -130,8 +135,10 @@ void clear_settings();
 int process_command_line (int argc, char **argv);
 int process_configfile (char *cfgfile);
 void set_default_settings();
-int daemonize();
+void install_signal_handlers (int allow_reload);
-int init_sockets();
+void child_ok_func (int signal);
+pid_t daemonize();
+int wave_to_parent (pid_t parent_pid);
 int init_drivers();
 int drop_privs(char *user);
 int init_screens();
@@ -150,17 +157,11 @@ int
 main (int argc, char **argv)
 {
 	int e = 0;
+	pid_t parent_pid = 0;
 
 	stored_argc = argc;
 	stored_argv = argv;
 
-	signal (SIGINT, exit_program);		/* Ctrl-C will cause a clean exit...*/
-	signal (SIGTERM, exit_program);		/* and "kill"...*/
-	signal (SIGKILL, exit_program);		/* and just in case, "kill -KILL" (which cannot be trapped; but oh well)*/
-
-	signal (SIGHUP, catch_reload_signal);	/* On SIGHUP reread config and restart the drivers ! */
-	/* Let's see if we can actually get this to work ;) */
-
 	/*
 	 * Settings in order of preference:
 	 *
@@ -205,27 +206,35 @@ main (int argc, char **argv)
  	report( RPT_INFO, "Set report level to %d, output to %s", report_level, (report_to_syslog?"syslog":"stderr") );
 	CHAIN_END( e, "Critical error while processing settings, abort." );
 
-	/* Startup the server*/
+	/* Now, go into daemon mode (if we should)...
-	CHAIN( e, screenlist_init() );
+	 * We wait for the child to report it is running OK. This mechanism
-	CHAIN( e, init_drivers() );
+	 * is used because forking after starting the drivers causes the
-	CHAIN( e, init_sockets() );
+	 * child to loose the (LPT) port access. */
-	CHAIN( e, input_init() );
+	if (!foreground_mode) {
-	CHAIN( e, menuscreens_init() );
-	CHAIN( e, server_screen_init() );
-	CHAIN( e, drop_privs(user) );
-	CHAIN_END( e, "Critical error while initializing, abort." );
-
-	/* Now, go into daemon mode...*/
-	/* TODO: do this earlier and let parent process wait until
-	 * child has fully started or reported its errors. */
-	if (daemon_mode) {
 		report(RPT_INFO, "Server forking to background");
-		CHAIN( e, daemonize() );
+		CHAIN( e, parent_pid = daemonize() );
 	} else {
 		output_GPL_notice();
 		report(RPT_INFO, "Server running in foreground");
 	}
+	install_signal_handlers (!foreground_mode);
+		/* Only catch SIGHUP if not in foreground mode */
+
+	/* Startup the subparts of the server */
+	CHAIN( e, sock_init() );
+	CHAIN( e, screenlist_init() );
+	CHAIN( e, init_drivers() );
+	CHAIN( e, clients_init() );
+	CHAIN( e, input_init() );
+	CHAIN( e, menuscreens_init() );
+	CHAIN( e, server_screen_init() );
 	CHAIN_END( e, "Critical error while initializing, abort." );
+	if (!foreground_mode) {
+		/* Tell to parent that startup went OK. */
+		wave_to_parent (parent_pid);
+	}
+	drop_privs(user); /* This can't be done before, because sending a
+			signal to a process of a different user will fail */
 
 	do_mainloop();
 	/* This loop never stops; we'll get out only with a signal...*/
@@ -241,11 +250,11 @@ clear_settings ()
 
 	debug( RPT_DEBUG, "%s()", __FUNCTION__ );
 
-	lcd_port = UNSET_INT;
+	bind_port = UNSET_INT;
 	strncpy( bind_addr, UNSET_STR, sizeof(bind_addr) );
 	strncpy( configfile, UNSET_STR, sizeof(configfile) );
 	strncpy( user, UNSET_STR, sizeof(user) );
-	daemon_mode = UNSET_INT;
+	foreground_mode = UNSET_INT;
 	rotate_server_screen = UNSET_INT;
 	backlight = UNSET_INT;
 
@@ -303,7 +312,7 @@ process_command_line (int argc, char **argv)
 					report( RPT_ERR, "Not a boolean value: '%s'", optarg );
 					e = -1;
 				} else {
-					daemon_mode = !b;
+					foreground_mode = b;
 				}
 				break;
 			case 'a':
@@ -311,7 +320,7 @@ process_command_line (int argc, char **argv)
 				bind_addr[sizeof(bind_addr)-1] = 0; /* Terminate string */
 				break;
 			case 'p':
-				lcd_port = atoi(optarg);
+				bind_port = atoi(optarg);
 				break;
 			case 'u':
 				strncpy(user, optarg, sizeof(user));
@@ -385,8 +394,8 @@ process_configfile ( char *configfile )
 		report( RPT_WARNING, "Could not read config file: %s", configfile );
 	}
 
-	if( lcd_port == UNSET_INT )
+	if( bind_port == UNSET_INT )
-		lcd_port = config_get_int( "server", "port", 0, UNSET_INT );
+		bind_port = config_get_int( "server", "port", 0, UNSET_INT );
 
 	if( strcmp( bind_addr, UNSET_STR ) == 0 )
 		strncpy( bind_addr, config_get_string( "server", "bind", 0, UNSET_STR ), sizeof(bind_addr));
@@ -404,11 +413,11 @@ process_configfile ( char *configfile )
 		}
 	}
 
-	if( daemon_mode == UNSET_INT ) {
+	if( foreground_mode == UNSET_INT ) {
 		int fg;
 		fg = config_get_bool( "server", "foreground", 0, UNSET_INT );
 		if( fg != UNSET_INT )
-			daemon_mode = !fg;
+			foreground_mode = fg;
 	}
 
 	if( rotate_server_screen == UNSET_INT ) {
@@ -470,15 +479,15 @@ set_default_settings()
 
 	/* Set defaults into unfilled variables....*/
 
-	if (lcd_port == UNSET_INT)
+	if (bind_port == UNSET_INT)
-		lcd_port = DEFAULT_BIND_PORT;
+		bind_port = DEFAULT_BIND_PORT;
 	if (strcmp( bind_addr, UNSET_STR ) == 0)
 		strncpy (bind_addr, DEFAULT_BIND_ADDR, sizeof(bind_addr));
 	if (strcmp( user, UNSET_STR ) == 0)
 		strncpy(user, DEFAULT_USER, sizeof(user));
 
-	if (daemon_mode == UNSET_INT)
+	if (foreground_mode == UNSET_INT)
-		daemon_mode = DEFAULT_DAEMON_MODE;
+		foreground_mode = DEFAULT_FOREGROUND_MODE;
 	if (rotate_server_screen == UNSET_INT)
 		rotate_server_screen = DEFAULT_ROTATE_SERVER_SCREEN;
 
@@ -502,52 +511,112 @@ set_default_settings()
 }
 
 
-int
+void
+install_signal_handlers (int allow_reload)
+{
+	/* Installs signal handlers so that the program does clean exit and
+	 * can also receive a reload signal.
+	 * sigaction() is favoured over signal() */
+
+	struct sigaction sa;
+
+	debug( RPT_DEBUG, "%s( allow_reload=%d )", __FUNCTION__, allow_reload );
+
+	sa.sa_handler = exit_program;
+	sigemptyset ( &(sa.sa_mask) );
+	sa.sa_flags = SA_RESTART;
+
+	sigaction (SIGINT, &sa, NULL);		/* Ctrl-C will cause a clean exit...*/
+	sigaction (SIGTERM, &sa, NULL);		/* and "kill"...*/
+
+	if (allow_reload) {
+		sa.sa_handler = catch_reload_signal;
+		/* On SIGHUP reread config and restart the drivers ! */
+	}
+	else {
+		/* Treat this signal just like INT and TERM */
+	}
+	sigaction (SIGHUP, &sa, NULL);
+}
+
+
+void
+child_ok_func (int signal) {
+	/* We only catch this signal to be sure the child runs OK. */
+
+	debug( RPT_INFO, "%s( signal=%d )", __FUNCTION__, signal );
+
+	/* Exit now !    because of bug? in wait() */
+	_exit( 0 ); /* Parent exits normally. */
+}
+
+
+pid_t
 daemonize()
 {
-	int child;
+	pid_t child;
+	pid_t parent;
+	int child_status;
+	struct sigaction sa;
 
 	debug( RPT_DEBUG, "%s()", __FUNCTION__ );
 
+	parent = getpid();
+	debug( RPT_INFO, "parent = %d", parent );
+
+	/* Install handler at parent for child's signal */
+	/* sigaction should be more portable than signal, but it does not
+	 * work for some reason. */
+	sa.sa_handler = child_ok_func;
+	sigemptyset ( &(sa.sa_mask) );
+	sa.sa_flags = SA_RESTART;
+	sigaction (SIGUSR1, &sa, NULL);
+
+	/* Do the fork */
 	switch ((child = fork ()) ) {
 	  case -1:
-		report(RPT_ERR, "Could not fork");
+		report( RPT_ERR, "Could not fork" );
 		return -1;
-	  case 0: /* We are the child*/
+	  case 0: /* We are the child */
 		break;
-	  default: /* We are the parent*/
+	  default: /* We are the parent */
-		usleep (1500000);		  /* Wait for child to initialize*/
+		debug( RPT_INFO, "child = %d", child );
-		exit (0);				  /* PARENT EXITS */
+		wait( &child_status );
+		/* BUG? According to the man page wait() should also return
+		 * when a signal comes in that is caught. Instead it
+		 * continues to wait. */
+
+		if( WIFEXITED(child_status) ) {
+			/* Child exited normally, probably because of some
+			 * error. */
+			debug( RPT_INFO, "Child has terminated!" );
+			exit( WEXITSTATUS(child_status) );
+			/* Parent exits with same status as child did... */
+		}
+		/* Child is still running and has signalled it's OK.
+		 * This means the parent can now rest in peace. */
+		debug( RPT_INFO, "Got OK signal from child." );
+		exit( 0 ); /* Parent exits normally. */
 	}
-	/* This line removed because it eats error messages...
+	/* At this point we are always the child. */
-	 * setsid();*/                                       /* RELEASE TTY */
+	/* Reset signal handler */
-	/*
+	sa.sa_handler = SIG_DFL;
-	 * After this point, as a daemon, no error messages should
+	sigaction (SIGUSR1, &sa, NULL);
-	 * go to the console unless drastic; rather, they should go to syslog
+
-	 *
+	setsid();	/* Create a new session because otherwise we'll
-	 * However, option processing is not yet done, nor is any initialization (!)
+			 * catch a SIGHUP when the shell is closed. */
-	 * So we must wait until the main loop.
+
-	 */
+	return parent;
-	return 0;
 }
 
 
 int
-init_sockets ()
+wave_to_parent (pid_t parent_pid)
 {
-	debug( RPT_DEBUG, "%s()", __FUNCTION__ );
+	debug( RPT_DEBUG, "%s( parent_pid=%d )", __FUNCTION__, parent_pid );
 
-	if (sock_create_server (&bind_addr, lcd_port) <= 0) {
+	kill( parent_pid, SIGUSR1 );
-		report(RPT_ERR, "Error opening socket");
-		return -1;
-	}
 
-	/* Now init a bunch of required stuff...*/
-
-	if (clients_init () < 0) {
-		report(RPT_ERR, "Error initializing client list");
-		return -1;
-	}
 	return 0;
 }
 
@@ -574,9 +643,7 @@ init_drivers()
 			  	output_loaded = 1;
 			  	break;
 			  case 2: /* Driver does output in foreground (don't daemonize) */
-			  	if ( !output_loaded ) {
+			  	foreground_mode = 1;
-			  		daemon_mode = 0;
-			  	}
 			  	output_loaded = 1;
 			  	break;
 			}
@@ -782,6 +849,7 @@ exit_program (int val)
 	screenlist_shutdown ();		/* shutdown screens (must come after client_shutdown) */
 	input_shutdown ();		/* shutdown key input part */
 
+	report( RPT_INFO, "Exiting." );
 	_exit (0);
 }
 

server/main.h

@@ -42,4 +42,29 @@ extern long int timer;
  * If you get an overflow, please mail us and we will fix this personally
  * for you ! */
 
+/**** Configuration variables ****/
+/* Only configuration items that are settable from the command line should
+ * be mentioned here. See main.c.
+ */
+
+extern unsigned int bind_port;
+extern char bind_addr[];	/* Do not preinit these strings as they will occupy */
+extern char configfile[];	/* a lot of space in the executable. */
+extern char user[];		/* The values will be overwritten anyway... */
+
+extern int foreground_mode;
+
+extern int report_level;
+extern int report_to_syslog;
+
+/* The drivers and their driver parameters */
+extern char *drivernames[];
+extern int num_drivers;
+
+/* End of configuration variables */
+
+/* Defines for having 'unset' values*/
+#define UNSET_INT -1
+#define UNSET_STR "\01"
+
 #endif

server/sock.c

@@ -32,6 +32,7 @@
 #include <string.h>
 
 #include "shared/sockets.h"
+#include "main.h"
 #include "sock.h"
 #include "client.h"
 #include "clients.h"
@@ -39,19 +40,57 @@
 #include "shared/report.h"
 #include "screenlist.h"
 
-extern char bind_addr[64];
-extern int lcd_port;
-
 
 fd_set active_fd_set, read_fd_set;
-int orig_sock;
+int listening_fd;
 
 /* Length of longest transmission allowed at once...*/
 #define MAXMSG 8192
 
-int read_from_client (int filedes);
+int sock_read_from_client (int filedes);
 
-/* Creates a socket in internet space*/
+
+int
+sock_init ()
+{
+	debug (RPT_DEBUG, "%s( bind_addr=\"%s\", port=%d )", __FUNCTION__, bind_addr, bind_port);
+
+	/* Create the socket and set it up to accept connections. */
+	listening_fd = sock_create_inet_socket (bind_addr, bind_port);
+	if (listening_fd < 0) {
+		report (RPT_ERR, "%s: Error creating socket", __FUNCTION__);
+		return -1;
+	}
+	return 0;
+}
+
+/*
+This code gets the send and receive buffer sizes.
+  {
+     int val, len, sock;
+     sock = new;
+
+     len = sizeof(int);
+     getsockopt(sock, SOL_SOCKET, SO_SNDBUF, &val, &len);
+     debug(RPT_DEBUG, "SEND buffer: %i bytes", val);
+
+     len = sizeof(int);
+     getsockopt(sock, SOL_SOCKET, SO_RCVBUF, &val, &len);
+     debug(RPT_DEBUG, "RECV buffer: %i bytes", val);
+  }
+*/
+
+
+int
+sock_shutdown ()
+{
+	debug( RPT_DEBUG, "%s()", __FUNCTION__ );
+
+	close( listening_fd );
+}
+
+
+/* Creates a socket in internet space */
 int
 sock_create_inet_socket (char * addr, unsigned int port)
 {
@@ -61,7 +100,6 @@ sock_create_inet_socket (char * addr, unsigned int port)
 	debug (RPT_DEBUG, "%s( addr=\"%s\", port=%i )", __FUNCTION__, addr, port);
 
 	/* Create the socket. */
-	/*debug(RPT_DEBUG, "Creating Inet Socket");*/
 	sock = socket (PF_INET, SOCK_STREAM, 0);
 	if (sock < 0) {
 		report(RPT_ERR, "%s: Could not create socket", __FUNCTION__);
@@ -86,25 +124,6 @@ sock_create_inet_socket (char * addr, unsigned int port)
 		report(RPT_NOTICE, "Listening for queries on %s:%d", addr, port);
 	}
 
-	return sock;
-
-}
-
-/*int StartSocketServer()*/
-int
-sock_create_server (char *bind_addr, int lcd_port)
-{
-	int sock;
-
-	debug (RPT_DEBUG, "%s( bind_addr=\"%s\", port=%d )", __FUNCTION__, bind_addr, lcd_port);
-
-	/* Create the socket and set it up to accept connections. */
-	sock = sock_create_inet_socket (bind_addr, lcd_port);
-	if (sock < 0) {
-		report (RPT_ERR, "%s: Error creating socket", __FUNCTION__);
-		return -1;
-	}
-
 	if (listen (sock, 1) < 0) {
 		report(RPT_ERR, "%s: error in attempting to listen to port", __FUNCTION__);
 		return -1;
@@ -114,28 +133,11 @@ sock_create_server (char *bind_addr, int lcd_port)
 	FD_ZERO (&active_fd_set);
 	FD_SET (sock, &active_fd_set);
 
-	orig_sock = sock;
-
-/*
-  {
-     int val, len, sock;
-     sock = new;
-
-     len = sizeof(int);
-     getsockopt(sock, SOL_SOCKET, SO_SNDBUF, &val, &len);
-     debug(RPT_DEBUG, "SEND buffer: %i bytes", val);
-
-     len = sizeof(int);
-     getsockopt(sock, SOL_SOCKET, SO_RCVBUF, &val, &len);
-     debug(RPT_DEBUG, "RECV buffer: %i bytes", val);
-  }
-*/
-
 	return sock;
 }
 
-/* Service all clients with input pending...*/
 
+/* Service all clients with input pending...*/
 int
 sock_poll_clients ()
 {
@@ -162,11 +164,11 @@ sock_poll_clients ()
 	/* Service all the sockets with input pending. */
 	for (i = 0; i < FD_SETSIZE; ++i) {
 		if (FD_ISSET (i, &read_fd_set)) {
-			if (i == orig_sock) {
+			if (i == listening_fd) {
 				/* Connection request on original socket. */
 				int new_sock;
 				size = sizeof (clientname);
-				new_sock = accept (orig_sock, (struct sockaddr *) &clientname, &size);
+				new_sock = accept (listening_fd, (struct sockaddr *) &clientname, &size);
 				if (new_sock < 0) {
 					report (RPT_ERR, "%s: Accept error", __FUNCTION__);
 					return -1;
@@ -191,7 +193,7 @@ sock_poll_clients ()
 				err = 0;
 				do {
 					debug (RPT_DEBUG, "%s: reading...", __FUNCTION__);
-					err = read_from_client (i);
+					err = sock_read_from_client (i);
 					debug (RPT_DEBUG, "%s: ...done", __FUNCTION__);
 					if (err < 0) {
 						/* Client disconnected, destroy client data */
@@ -203,8 +205,9 @@ sock_poll_clients ()
 							clients_remove_client (c);
 							close (i);
 							FD_CLR (i, &active_fd_set);
-						} else
+						} else {
 							report (RPT_ERR, "%s: Can't find client of socket %i", __FUNCTION__, i);
+						}
 					}
 				} while (err > 0);
 			}
@@ -214,7 +217,7 @@ sock_poll_clients ()
 }
 
 int
-read_from_client (int filedes)
+sock_read_from_client (int filedes)
 {
 	char buffer[MAXMSG];
 	int nbytes, i;

server/sock.h

@@ -9,17 +9,17 @@
  *
  */
 
-#ifndef SOCKETS_H
+#ifndef SOCK_H
-#define SOCKETS_H
+#define SOCK_H
 
 #include "shared/sockets.h"
 
 typedef struct sockaddr_in sockaddr_in;
 
 /* Server functions...*/
-int sock_create_server ();
+int sock_init ();
-int sock_create_inet_socket (unsigned short int port);
+int sock_shutdown ();
+int sock_create_inet_socket (char * addr, unsigned int port);
 int sock_poll_clients ();
-int read_from_client (int filedes);
 
 #endif