X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=server.c;h=caeeba420eb55b8b2775f671b064dfb9b1dee181;hp=6f70d977d0814e0c7fa5a54581baf405397ea259;hb=2b471378b49c04db7bb84d1e75db981f91ad93db;hpb=8f2cf66189cc863c3af702f78bb68596f2f3ef12

diff --git a/server.c b/server.c
index 6f70d977..caeeba42 100644
--- a/server.c
+++ b/server.c
@@ -1,47 +1,91 @@
 /*
- * Copyright (C) 1997-2006 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 1997-2008 Andre Noll <maan@systemlinux.org>
  *
- *     This program is free software; you can redistribute it and/or modify
- *     it under the terms of the GNU General Public License as published by
- *     the Free Software Foundation; either version 2 of the License, or
- *     (at your option) any later version.
- *
- *     This program is distributed in the hope that it will be useful,
- *     but WITHOUT ANY WARRANTY; without even the implied warranty of
- *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *     GNU General Public License for more details.
- *
- *     You should have received a copy of the GNU General Public License
- *     along with this program; if not, write to the Free Software
- *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
+ * Licensed under the GPL v2. For licencing details see COPYING.
  */
 
-/** \file server.c Paraslash's main server */
+/** \file server.c Paraslash's main server. */
 
 
-/** \mainpage Paraslash API Reference
+/**
+ * \mainpage Paraslash API Reference
+ *
+ * Starting points for getting an overview are
+ *
+ * probably:
+ *
+ * 	- The main programs: \ref server.c, \ref audiod.c, \ref client.c,
+ *	  \ref audioc.c, \ref fsck.c,
+ *	- Server: \ref server_command, \ref sender,
+ *	- Audio file selector: \ref audio_format_handler, \ref mood, \ref afs_table,
+ *	- Client: \ref receiver, \ref receiver_node, \ref filter, \ref filter_node.
+ *
+ *
+ * The gory details, listed by topic:
+ *
+ * 	- Audio format handlers: \ref mp3_afh.c, \ref ogg_afh.c, \ref aac_afh.c,
+ * 	- Decoders: \ref mp3dec.c, \ref oggdec.c, \ref aacdec.c,
+ *	- Volume normalizer: \ref compress.c,
+ *	- Output: \ref alsa_write.c, \ref osx_write.c,
+ * 	- http: \ref http_recv.c, \ref http_send.c,
+ *	- ortp: \ref ortp_recv.c, \ref ortp_send.c,
+ *	- dccp: \ref dccp_recv.c, \ref dccp_send.c,
+ *	- Audio file selector: \ref afs.c, \ref aft.c, \ref mood.c,
+ *	- Afs structures: \ref afs_table, \ref audio_file_data,
+ *	  \ref afs_info \ref afh_info,
+ *	- Afs tables: \ref aft.c, \ref mood.c, \ref playlist.c,
+ *	  \ref attribute.c, \ref score.c,
+ *	- The virtual streaming system: \ref vss.c, \ref chunk_queue.c.
  *
- *  Good starting points for reading are probably \ref audio_file_selector,
- *  \ref sender, \ref receiver, \ref receiver_node, \ref filter, \ref
- *  filter_node.
+ * Lower levels:
+ *
+ *	- Scheduling: \ref sched.c, \ref sched.h,
+ * 	- Networking: \ref net.c,
+ *	- File descriptors: \ref fd.c,
+ *	- Signals: \ref signal.c,
+ *	- Daemons: \ref daemon.c,
+ *	- Strings: \ref string.c, \ref string.h,
+ *	- Time: \ref time.c,
+ *	- Spawning processes: \ref exec.c,
+ *	- Inter process communication: \ref ipc.c,
+ *	- The object storage layer: \ref osl.c,
+ *	- Blob tables: \ref blob.c,
+ *	- The error subssystem: \ref error.h.
+ *	- Access control for paraslash senders: \ref acl.c, \ref acl.h.
+ *
+ * Low-level data structures:
+ *
+ *	- Doubly linked lists: \ref list.h,
+ *	- Red-black trees: \ref rbtree.h, \ref rbtree.c,
+ *	- Ring buffer: \ref ringbuffer.c, \ref ringbuffer.h,
+ *	- Hashing: \ref hash.h, \ref sha1.h, \ref sha1.c,
+ *	- Crypto: \ref crypt.c.
  *
  */
 
+#include <signal.h>
+#include <sys/types.h>
+#include <dirent.h>
 
-
+#include "para.h"
+#include "error.h"
 #include "server.cmdline.h"
-#include "db.h"
-#include "server.h"
+#include "afh.h"
+#include "string.h"
 #include "afs.h"
+#include "server.h"
+#include "vss.h"
 #include "config.h"
 #include "close_on_fork.h"
+#include "list.h"
 #include "send.h"
-#include "error.h"
 #include "net.h"
 #include "daemon.h"
-#include "string.h"
 #include "ipc.h"
 #include "fd.h"
+#include "sched.h"
+#include "signal.h"
+#include "user_list.h"
 
 /** define the array of error lists needed by para_server */
 INIT_SERVER_ERRLISTS;
@@ -49,76 +93,40 @@ INIT_SERVER_ERRLISTS;
 /** shut down non-authorized connections after that many seconds */
 #define ALARM_TIMEOUT 10
 
-/* these are exported to afs.c. command.c and to all selectors */
+/**
+ * Pointer to shared memory area for communication between para_server
+ * and its children. Exported to vss.c. command.c and to afs.
+ */
 struct misc_meta_data *mmd;
-/** the configuration of para_server
- *
- * It also contains the options for all audio file selectors and all supported
- * senders.
-*/
-struct gengetopt_args_info conf;
-char *user_list = NULL;
-extern void dccp_send_init(struct sender *);
-extern void http_send_init(struct sender *);
-extern void ortp_send_init(struct sender *);
-extern struct audio_format afl[];
-
-/* TODO: This is better handled by autoconf */
-/** the list of supported audio file selectors */
-struct audio_file_selector selectors[] = {
-	{
-		.name = "random",
-		.init = random_selector_init,
-		.update_audio_file = NULL,
-	},
-	{
-		.name = "playlist",
-		.init = playlist_selector_init,
-		.update_audio_file = NULL,
-		.pre_select = NULL,
-		.post_select = NULL,
-	},
-#ifdef HAVE_MYSQL
-	{
-		.name = "mysql",
-		.init = mysql_selector_init,
-		.update_audio_file = NULL,
-		.pre_select = NULL,
-		.post_select = NULL,
-	},
-#endif
-	{
-		.name = NULL,
-	}
-};
 
-/** the list of supported senders */
-struct sender senders[] = {
-	{
-		.name = "http",
-		.init = http_send_init,
-	},
-	{
-		.name = "dccp",
-		.init = dccp_send_init,
-	},
-#ifdef HAVE_ORTP
-	{
-		.name = "ortp",
-		.init = ortp_send_init,
-	},
-#endif
-	{
-		.name = NULL,
-	}
-};
+/**
+ * the configuration of para_server
+ *
+ * It also contains the options for the audio file selector, audio format
+ * handler and all supported senders.
+ */
+struct server_args_info conf;
 
+/** the file containing user information (public key, permissions) */
+char *user_list_file = NULL;
 
 /* global variables for server-internal use */
 static FILE *logfile;
 static int mmd_mutex, mmd_shm_id;
 static int signal_pipe;
 
+struct server_command_task {
+	/** TCP port on which para_server listens for connections. */
+	int listen_fd;
+	/** Copied from para_server's main function. */
+	int argc;
+	/** Argument vector passed to para_server's main function. */
+	char **argv;
+	/** The command task structure for scheduling. */
+	//struct task task;
+	char dummy;
+};
+
 /**
  * para_server's log function
  *
@@ -145,7 +153,7 @@ void para_log(int ll, const char* fmt,...)
 		fprintf(outfd, "%i: ", ll);
 	mypid = getpid();
 	if (conf.loglevel_arg <= INFO)
-		fprintf(outfd, "(%d) ", mypid);
+		fprintf(outfd, "(%d) ", (int)mypid);
 	va_start(argp, fmt);
 	vfprintf(outfd, fmt, argp);
 	va_end(argp);
@@ -173,27 +181,23 @@ static void shm_init(void)
 		goto err_out;
 	mmd_mutex = ret;
 
-	mmd->selector_num = 0;
 	mmd->num_played = 0;
 	mmd->num_commands = 0;
 	mmd->events = 0;
 	mmd->num_connects = 0;
 	mmd->active_connections = 0;
-	strcpy(mmd->filename, "(none)");
-	mmd->audio_format = -1;
-	mmd->afs_status_flags = AFS_NEXT;
-	mmd->new_afs_status_flags = AFS_NEXT;
-	mmd->sender_cmd_data.cmd_num = -1;
+	mmd->vss_status_flags = VSS_NEXT;
+	mmd->new_vss_status_flags = VSS_NEXT;
 	return;
 err_out:
-	PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
+	PARA_EMERG_LOG("%s\n", para_strerror(-ret));
 	exit(EXIT_FAILURE);
 }
 
 /**
  * lock the shared memory area containing the mmd struct
  *
- * \sa semop(2), struct misc_meta_data
+ * \sa semop(2), struct misc_meta_data.
  */
 void mmd_lock(void)
 {
@@ -219,14 +223,14 @@ static void parse_config(int override)
 	char *cf;
 
 	if (conf.config_file_given)
-		cf = conf.config_file_arg;
+		cf = para_strdup(conf.config_file_arg);
 	else
 		cf = make_message("%s/.paraslash/server.conf", home);
-	free(user_list);
+	free(user_list_file);
 	if (!conf.user_list_given)
-		user_list = make_message("%s/.paraslash/server.users", home);
+		user_list_file = make_message("%s/.paraslash/server.users", home);
 	else
-		user_list = para_strdup(conf.user_list_arg);
+		user_list_file = para_strdup(conf.user_list_arg);
 	ret = stat(cf, &statbuf);
 	if (ret && conf.config_file_given) {
 		ret = -1;
@@ -235,15 +239,16 @@ static void parse_config(int override)
 	}
 	if (!ret) {
 		int tmp = conf.daemon_given;
-		cmdline_parser_configfile(cf, &conf, override, 0, 0);
+		struct server_cmdline_parser_params params = {
+			.override = override,
+			.initialize = 0,
+			.check_required = 1,
+			.check_ambiguity = 0,
+			.print_errors = 1
+		};
+		server_cmdline_parser_config_file(cf, &conf, &params);
 		conf.daemon_given = tmp;
 	}
-	/* logfile */
-	if (!conf.logfile_given && conf.daemon_given) {
-		ret = -1;
-		PARA_EMERG_LOG("%s", "daemon, but no log file\n");
-		goto out;
-	}
 	if (conf.logfile_given)
 		logfile = open_log(conf.logfile_arg);
 	ret = 1;
@@ -252,137 +257,146 @@ out:
 	free(home);
 	if (ret > 0)
 		return;
-	free(user_list);
-	user_list = NULL;
+	free(user_list_file);
+	user_list_file = NULL;
 	exit(EXIT_FAILURE);
 }
 
 static void setup_signal_handling(void)
 {
-	int ret = 0;
-
-	signal_pipe = para_signal_init();
-	PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
-	ret += para_install_sighandler(SIGINT);
-	ret += para_install_sighandler(SIGTERM);
-	ret += para_install_sighandler(SIGHUP);
-	ret += para_install_sighandler(SIGCHLD);
-	ret += para_install_sighandler(SIGUSR1);
-	signal(SIGPIPE, SIG_IGN);
-	if (ret != 5) {
-		PARA_EMERG_LOG("%s", "could not install signal handlers\n");
-		exit(EXIT_FAILURE);
-	}
-}
-
-static void init_selector(void)
-{
-	int i, ret;
-
-	mmd->selector_change = -1; /* no change nec., set to new num by com_chs */
-	if (!conf.selector_given)
-		goto random;
-	for (i = 0; selectors[i].name; i++) {
-		if (strcmp(selectors[i].name, conf.selector_arg))
-			continue;
-		PARA_NOTICE_LOG("initializing %s audio file selector\n",
-			selectors[i].name);
-		ret = selectors[i].init(&selectors[i]);
-		if (ret < 0) {
-			PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
-			break;
-		}
-		mmd->selector_num = i;
-		return;
-	}
-	PARA_WARNING_LOG("%s", "falling back to the random selector\n");
-random:
-	mmd->selector_num = 0;
-	selectors[0].init(&selectors[0]); /* always successful */
+	signal_pipe = para_signal_init(); /* always successful */
+
+	PARA_NOTICE_LOG("setting up signal handlers\n");
+	if (para_install_sighandler(SIGINT) < 0)
+		goto err;
+	if (para_install_sighandler(SIGTERM) < 0)
+		goto err;
+	if (para_install_sighandler(SIGHUP) < 0)
+		goto err;
+	if (para_install_sighandler(SIGCHLD) < 0)
+		goto err;
+	if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
+		goto err;
+	if (signal(SIGUSR1, SIG_IGN) == SIG_ERR)
+		goto err;
+	add_close_on_fork_list(signal_pipe);
+	return;
+err:
+	PARA_EMERG_LOG("could not install signal handlers\n");
+	exit(EXIT_FAILURE);
 }
 
-static unsigned init_network(void)
+static void init_command_task(struct server_command_task *sct)
 {
-	int sockfd = init_tcp_socket(conf.port_arg);
+	int ret;
 
-	if (sockfd < 0)
-		exit(EXIT_FAILURE);
-	return sockfd;
+	PARA_NOTICE_LOG("initializing tcp command socket\n");
+	ret = para_listen(AF_UNSPEC, IPPROTO_TCP, conf.port_arg);
+	if (ret < 0)
+		goto err;
+	sct->listen_fd = ret;
+	ret = mark_fd_nonblocking(sct->listen_fd);
+	if (ret < 0)
+		goto err;
+	add_close_on_fork_list(sct->listen_fd); /* child doesn't need the listener */
+	return;
+err:
+	PARA_EMERG_LOG("%s\n", para_strerror(-ret));
+	exit(EXIT_FAILURE);
 }
 
 static void init_random_seed(void)
 {
-	int fd, ret = -1, len = sizeof(unsigned int);
 	unsigned int seed;
+	int fd, ret = para_open("/dev/urandom", O_RDONLY, 0);
 
-	fd = open("/dev/urandom", O_RDONLY);
-	if (fd < 0)
+	if (ret < 0)
+		goto err;
+	fd = ret;
+	ret = read(fd, &seed, sizeof(seed));
+	if (ret < 0) {
+		ret = -ERRNO_TO_PARA_ERROR(errno);
 		goto out;
-	ret = -2;
-	if (read(fd, &seed, len) != len)
+	}
+	if (ret != sizeof(seed)) {
+		ret = -ERRNO_TO_PARA_ERROR(EIO);
 		goto out;
+	}
 	srandom(seed);
 	ret = 1;
 out:
-	if (fd >= 0)
-		close(fd);
-	if (ret > 0)
+	close(fd);
+	if (ret >= 0)
 		return;
-	PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
-		ret);
+err:
+	PARA_EMERG_LOG("can not seed pseudo random number generator: %s\n",
+		para_strerror(-ret));
 	exit(EXIT_FAILURE);
 }
 
-static unsigned do_inits(int argc, char **argv)
+uint32_t afs_socket_cookie;
+int afs_socket;
+static pid_t afs_pid;
+
+static void init_afs(void)
 {
-	/* connector's address information */
-	int sockfd;
+	int ret, afs_server_socket[2];
 
+	ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
+	if (ret < 0)
+		exit(EXIT_FAILURE);
+	afs_socket_cookie = para_random((uint32_t)-1);
+	afs_pid = fork();
+	if (afs_pid < 0)
+		exit(EXIT_FAILURE);
+	if (!afs_pid) { /* child (afs) */
+		close(afs_server_socket[0]);
+		afs_init(afs_socket_cookie, afs_server_socket[1]);
+	}
+	close(afs_server_socket[1]);
+	afs_socket = afs_server_socket[0];
+	ret = mark_fd_nonblocking(afs_socket);
+	if (ret < 0)
+		exit(EXIT_FAILURE);
+	add_close_on_fork_list(afs_socket);
+	PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n", afs_socket,
+		(unsigned) afs_socket_cookie);
+}
+
+static void server_init(int argc, char **argv)
+{
+	/* connector's address information */
+	struct server_cmdline_parser_params params = {
+		.override = 0,
+		.initialize = 1,
+		.check_required = 0,
+		.check_ambiguity = 0,
+		.print_errors = 1
+	};
 	init_random_seed();
 	/* parse command line options */
-	cmdline_parser(argc, argv, &conf);
+	server_cmdline_parser_ext(argc, argv, &conf, &params);
+	HANDLE_VERSION_FLAG("server", conf);
 	para_drop_privileges(conf.user_arg, conf.group_arg);
 	/* parse config file, open log and set defaults */
 	parse_config(0);
 	log_welcome("para_server", conf.loglevel_arg);
 	shm_init(); /* init mmd struct */
 	server_uptime(UPTIME_SET); /* reset server uptime */
+	init_user_list(user_list_file);
 	/* become daemon */
 	if (conf.daemon_given)
 		daemon_init();
-	init_selector();
-	PARA_NOTICE_LOG("%s", "initializing audio file sender\n");
-	/* audio file sender */
-	afs_init();
+	PARA_NOTICE_LOG("initializing audio format handlers\n");
+	afh_init();
 	mmd->server_pid = getpid();
 	setup_signal_handling();
+	PARA_NOTICE_LOG("initializing the audio file selector\n");
+	init_afs();
+	PARA_NOTICE_LOG("initializing virtual streaming system\n");
+	vss_init();
 	mmd_lock();
-	/* init network socket */
-	PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
-	sockfd = init_network();
-	if (conf.autoplay_given) {
-		mmd->afs_status_flags |= AFS_PLAYING;
-		mmd->new_afs_status_flags |= AFS_PLAYING;
-	}
-	PARA_NOTICE_LOG("%s", "init complete\n");
-	return sockfd;
-}
-
-static void change_selector(void)
-{
-	int ret, old = mmd->selector_num, new = mmd->selector_change;
-
-	selectors[old].shutdown();
-	ret = selectors[new].init(&selectors[new]);
-	mmd->selector_change = -1; /* reset */
-	if (ret >= 0) {
-		mmd->selector_num = new;
-		return;
-	}
-	/* init failed */
-	PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
-	selectors[0].init(&selectors[0]);
-	mmd->selector_num = 0;
+	PARA_NOTICE_LOG("server init complete\n");
 }
 
 /*
@@ -390,12 +404,13 @@ static void change_selector(void)
  */
 static void handle_sighup(void)
 {
-	PARA_NOTICE_LOG("%s", "SIGHUP\n");
+	PARA_NOTICE_LOG("SIGHUP\n");
 	close_log(logfile); /* gets reopened if necessary by parse_config */
 	logfile = NULL;
 	parse_config(1); /* reopens log */
-	mmd->selector_change = mmd->selector_num; /* do not change selector.. */
-	change_selector(); /* .. just reload */
+	init_user_list(user_list_file); /* reload user list */
+	if (afs_pid)
+		kill(afs_pid, SIGHUP);
 }
 
 static void status_refresh(void)
@@ -405,7 +420,7 @@ static void status_refresh(void)
 
 	if (prev_events != mmd->events)
 		goto out;
-	if (mmd->new_afs_status_flags != mmd->afs_status_flags)
+	if (mmd->new_vss_status_flags != mmd->vss_status_flags)
 		goto out;
 	if (uptime / 60 != prev_uptime / 60)
 		goto out;
@@ -413,135 +428,138 @@ static void status_refresh(void)
 out:
 	prev_uptime = uptime;
 	prev_events = mmd->events;
-	mmd->afs_status_flags = mmd->new_afs_status_flags;
+	mmd->vss_status_flags = mmd->new_vss_status_flags;
 	if (ret) {
-		PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
-			mmd->events, mmd->audio_format);
+		PARA_DEBUG_LOG("%d events, forcing status update\n",
+			mmd->events);
 		killpg(0, SIGUSR1);
 	}
 }
 
-/*
- * MAIN
+static int server_select(int max_fileno, fd_set *readfds, fd_set *writefds,
+		struct timeval *timeout_tv)
+{
+	int ret;
+
+	status_refresh();
+	mmd_unlock();
+	ret = para_select(max_fileno + 1, readfds, writefds, timeout_tv);
+	mmd_lock();
+	return ret;
+}
+
+static void command_pre_select(int *max_fileno, fd_set *rfds, char *dummy_ptr)
+{
+	struct server_command_task *sct = container_of(dummy_ptr, struct server_command_task, dummy);
+	para_fd_set(sct->listen_fd, rfds, max_fileno);
+}
+
+static void command_post_select(fd_set *rfds, char *dummy_ptr)
+{
+	struct server_command_task *sct = container_of(dummy_ptr, struct server_command_task, dummy);
+
+	int new_fd, ret;
+	char *peer_name;
+	pid_t child_pid;
+
+	if (!FD_ISSET(sct->listen_fd, rfds))
+		return;
+	ret = para_accept(sct->listen_fd, NULL, 0);
+	if (ret < 0)
+		goto out;
+	new_fd = ret;
+	peer_name = remote_name(new_fd);
+	PARA_INFO_LOG("got connection from %s, forking\n", peer_name);
+	mmd->num_connects++;
+	mmd->active_connections++;
+	random();
+	child_pid = fork();
+	if (child_pid < 0) {
+		ret = -ERRNO_TO_PARA_ERROR(errno);
+		goto out;
+	}
+	if (child_pid) {
+		close(new_fd);
+		/* parent keeps accepting connections */
+		return;
+	}
+	alarm(ALARM_TIMEOUT);
+	close_listed_fds();
+	para_signal_shutdown();
+	/*
+	 * put info on who we are serving into argv[0] to make
+	 * client ip visible in top/ps
+	 */
+//	for (i = argc - 1; i >= 0; i--)
+//		memset(argv[i], 0, strlen(argv[i]));
+//	sprintf(argv[0], "para_server (serving %s)", peer_name);
+	return handle_connect(new_fd, peer_name);
+out:
+	if (ret < 0)
+		PARA_CRIT_LOG("%s\n", para_strerror(-ret));
+}
+
+/**
+ * the main function of para_server
+ *
+ * \param argc usual argument count
+ * \param argv usual argument vector
+ *
+ * \return EXIT_SUCCESS or EXIT_FAILURE
+ *
  */
 int main(int argc, char *argv[])
 {
-	/* listen on sock_fd, new connection on new_fd */
-	int sockfd, new_fd;
-	struct sockaddr_in their_addr;
-	int i, max_fileno, ret;
-	pid_t chld_pid;
+	int max_fileno, ret;
 	fd_set rfds, wfds;
 	struct timeval *timeout;
+	struct server_command_task server_command_task_struct;
+
 
 	valid_fd_012();
-	sockfd = do_inits(argc, argv);
+	server_init(argc, argv);
+	init_command_task(&server_command_task_struct);
 repeat:
 	FD_ZERO(&rfds);
 	FD_ZERO(&wfds);
 	max_fileno = -1;
-	/* check socket and signal pipe in any case */
-	para_fd_set(sockfd, &rfds, &max_fileno);
+	command_pre_select(&max_fileno, &rfds, &server_command_task_struct.dummy);
 	para_fd_set(signal_pipe, &rfds, &max_fileno);
-	timeout = afs_preselect();
-	status_refresh();
-	for (i = 0; senders[i].name; i++) {
-		if (senders[i].status != SENDER_ON)
-			continue;
-		if (!senders[i].pre_select)
-			continue;
-		senders[i].pre_select(mmd->audio_format >= 0?
-			&afl[mmd->audio_format] : NULL,
-			&max_fileno,
-			&rfds, &wfds);
-	}
-	if (selectors[mmd->selector_num].pre_select) {
-		ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
-		max_fileno = PARA_MAX(max_fileno, ret);
-	}
-	mmd_unlock();
-	ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
-	mmd_lock();
-	if (mmd->selector_change >= 0)
-		change_selector();
-	if (selectors[mmd->selector_num].post_select)
-		selectors[mmd->selector_num].post_select(&rfds, &wfds);
-	if (ret < 0)
-		goto repeat;
-	for (i = 0; senders[i].name; i++) {
-		if (senders[i].status != SENDER_ON)
-			continue;
-		if (!senders[i].post_select)
-			continue;
-		senders[i].post_select(mmd->audio_format >= 0?
-			&afl[mmd->audio_format] : NULL,
-			&rfds, &wfds);
-	}
-	if (!ret) {
-		afs_send_chunk();
-		status_refresh();
-	}
+	timeout = vss_preselect(&rfds, &wfds, &max_fileno);
+	server_select(max_fileno + 1, &rfds, &wfds, timeout);
+	vss_post_select(&rfds, &wfds);
 	if (FD_ISSET(signal_pipe, &rfds)) {
 		int sig;
+		pid_t pid;
 		sig = para_next_signal();
 		switch (sig) {
 		case SIGHUP:
 			handle_sighup();
 			break;
 		case SIGCHLD:
-			para_reap_children();
+			for (;;) {
+				ret = para_reap_child(&pid);
+				if (ret <= 0)
+					break;
+				if (pid != afs_pid)
+					continue;
+				PARA_EMERG_LOG("fatal: afs died\n");
+				goto genocide;
+			}
 			break;
 		/* die on sigint/sigterm. Kill all children too. */
 		case SIGINT:
 		case SIGTERM:
 			PARA_EMERG_LOG("terminating on signal %d\n", sig);
+genocide:
 			kill(0, SIGTERM);
-			selectors[mmd->selector_num].shutdown();
 			mutex_destroy(mmd_mutex);
 			shm_detach(mmd);
 			shm_destroy(mmd_shm_id);
+
 			exit(EXIT_FAILURE);
 		}
 	}
-	if (mmd->sender_cmd_data.cmd_num >= 0) {
-		int num = mmd->sender_cmd_data.cmd_num,
-			s = mmd->sender_cmd_data.sender_num;
-
-		if (senders[s].client_cmds[num])
-			senders[s].client_cmds[num](&mmd->sender_cmd_data);
-		mmd->sender_cmd_data.cmd_num = -1;
-	}
-	if (!FD_ISSET(sockfd, &rfds))
-		goto repeat;
-
-	new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
-	if (new_fd < 0)
-		goto repeat;
-	PARA_INFO_LOG("got connection from %s, forking\n",
-		inet_ntoa(their_addr.sin_addr));
-	mmd->num_connects++;
-	mmd->active_connections++;
-	random();
-	chld_pid = fork();
-	if (chld_pid < 0) {
-		PARA_CRIT_LOG("%s", "fork failed\n");
-		goto repeat;
-	}
-	if (chld_pid) {
-		close(new_fd);
-		/* parent keeps accepting connections */
-		goto repeat;
-	}
-	alarm(ALARM_TIMEOUT);
-	close_listed_fds();
-	close(sockfd); /* child doesn't need the listener */
-	/*
-	 * put info on who we are serving into argv[0] to make
-	 * client ip visible in top/ps
-	 */
-	for (i = argc - 1; i >= 0; i--)
-		memset(argv[i], 0, strlen(argv[i]));
-	sprintf(argv[0], "para_server (serving %s)",
-		inet_ntoa(their_addr.sin_addr));
-	return handle_connect(new_fd, &their_addr);
+	command_post_select(&rfds, &server_command_task_struct.dummy);
+	goto repeat;
 }