X-Git-Url: http://git.jankratochvil.net/?a=blobdiff_plain;f=src%2Fnetwork.c;h=40c2bf87cffd2e3b3e93d464ee02feb9d17545c3;hb=bc907812a9679456dd5947b61f4358b3b8e386ce;hp=e39dfc18a538264362f06179ec8f4160261d5219;hpb=75d48312f938ebe055459e9be96cdd1c3c4279be;p=udpgate.git

diff --git a/src/network.c b/src/network.c
index e39dfc1..40c2bf8 100644
--- a/src/network.c
+++ b/src/network.c
@@ -35,38 +35,66 @@
 #include <glib/galloca.h>
 #include <glib/gprintf.h>
 #include <glib/grand.h>
+#include <glib/gutils.h>
 
 #include "network.h"
 #include "packet.h"
+#include "main.h"	/* for optarg_verbose */
+#include "pathname.h"
 
 
 /* Config: */
-#define NETWORK_PATHNAME_PID "/var/run/udpgate.pid"
-#define SOCK_SOURCE_CHECK_EVENTS (G_IO_IN)	/* |G_IO_PRI */
-#define SOCK_SOURCE_CHECK_REVENTS (SOCK_SOURCE_CHECK_EVENTS)	/* |G_IO_ERR|G_IO_HUP|G_IO_NVAL */
-#define SERVER_INADDR 0x511F02EA	/* paulina.vellum.cz = 81.31.2.234; host order */
+#define SOCK_SOURCE_CHECK_REVENTS (G_IO_IN|G_IO_OUT)	/* |G_IO_ERR|G_IO_HUP|G_IO_NVAL */
+#define SERVER_INADDR 0xC37AD054	/* mms2.org = 195.122.208.84; host order */
 #define SERVER_PORT   9201	/* host order */
 #define PROBE_INADDR  SERVER_INADDR	/* host order */
 #define PROBE_PORT    8201	/* host order */
 #define CLIENT_TIMEOUT_SEC (5*60)
-#define PROBE_TIMEOUT_SEC (5)
+#define PROBE_TIMEOUT_SEC_BASE 5
+#define PROBE_TIMEOUT_SEC_MAX 3500
+#define TCP_BACKLOG 5
+#define GSTRING_TO_SEND_MAX 1500*6	/* maximum data buffered per TCP client */
 
 
-void (*network_notify_hostip)(guint32 hostip_guint32,const gchar *hostip_string);
+void (*network_notify_hostip)(guint32 hostip_guint32);
+
+
+static G_CONST_RETURN gchar *pid_pathname(void)
+{
+static const gchar *static_pathname;
+static const char *user_val;
+
+	if (!static_pathname)
+		user_val=g_get_user_name();
+	return pathname_find(&static_pathname,
+			G_STRINGIFY(LOCALSTATEDIR) "/run",PACKAGE ".pid",
+			(!user_val ? NULL : g_get_tmp_dir()),
+					(!user_val ? NULL : udpgate_printf_alloca(".%s-%s.pid",user_val,PACKAGE)),
+			NULL);
+}
 
 
 struct client {
 	GPollFD gpollfd;
 	struct sockaddr_in sockaddr_in_from;
 	guint timeout_id;
+	struct client *bound;
+	unsigned connect_pending:1;	/* for TCP connection to the server; activated by: G_IO_OUT */
+	unsigned server_only:1;	/* nonimportant connect - the server side */
+	unsigned done:1;	/* temporary marker */
+	GString *gstring_to_send;	/* for TCP connections; data to be sent to this socket */
 	};
 
 static GSource *sock_gsource;
 
 static GList *sock_client_list;	/* of 'struct client *', incl. 'master' and 'probe' */
-static struct client *master;	/* no 'timeout' permitted */
+static struct client *master_udp;	/* no 'timeout' permitted */
+static struct client *master_tcp;	/* no 'timeout' permitted */
 static struct client *probe;	/* 'timeout' permitted */
 static guint32 probe_unique;
+static guint probe_timeout_sec_now;
+guint probe_timeout_sec_max=G_MAXUINT;
+static gint port_local;	/* for 'probe' resends */
 
 static gboolean write_daemon_running(pid_t pid);
 
@@ -79,7 +107,7 @@ int pid_int;
 	if (sock_gsource)
 		return getpid();
 
-	if (!(f=fopen(NETWORK_PATHNAME_PID,"r")))
+	if (!(f=fopen(pid_pathname(),"r")))
 		goto err;
 	got=fgets(buf,sizeof(buf),f);
 	fclose(f);	/* FIXME: error ignored */
@@ -105,15 +133,20 @@ static gboolean write_daemon_running(pid_t pid)
 FILE *f;
 
 	if (pid==(pid_t)-1) {
-		if (unlink(NETWORK_PATHNAME_PID)) {
+		if (unlink(pid_pathname())) {
 			if (errno!=ENOENT)
-				g_warning(_("Error removing PID file \"%s\": %m"),NETWORK_PATHNAME_PID);
+				g_warning(_("Error removing PID file \"%s\": %m"),pid_pathname());
 			return FALSE;
 			}
 		return TRUE;
 		}
-	if (!(f=fopen(NETWORK_PATHNAME_PID,"w"))) {
-		g_warning(_("Error writing PID %d to \"%s\": %m"),(int)pid,NETWORK_PATHNAME_PID);
+	if (!(f=fopen(pid_pathname(),"w"))) {
+static gboolean once=TRUE;
+
+		if (once) {
+			once=FALSE;
+			g_warning(_("Error writing PID %d to \"%s\": %m"),(int)pid,pid_pathname());
+			}
 		return FALSE;
 		}
 	fprintf(f,"%d\n",(int)pid);	/* errors ignored */
@@ -124,11 +157,14 @@ FILE *f;
 static void client_timeout_remove(struct client *client)
 {
 	g_return_if_fail(client!=NULL);
-	g_return_if_fail(client!=master);
+	g_return_if_fail(client!=master_udp);
+	g_return_if_fail(client!=master_tcp);
 
 	if (client->timeout_id) {
 gboolean errgboolean;
 
+		if (optarg_verbose)
+			g_message(_("Client fd %d removed timeout id %d"),client->gpollfd.fd,client->timeout_id);
 		errgboolean=g_source_remove(client->timeout_id);
 		g_assert(errgboolean==TRUE);
 		client->timeout_id=0;
@@ -137,66 +173,187 @@ gboolean errgboolean;
 
 static gboolean client_touch_timeout(struct client *client);
 
-static void client_touch(struct client *client)
+static void client_touch(struct client *client,guint timeout_sec)
 {
 	g_return_if_fail(client!=NULL);
-	g_return_if_fail(client!=master);
+	g_return_if_fail(client!=master_udp);
+	g_return_if_fail(client!=master_tcp);
+	g_return_if_fail(timeout_sec>0);
 
 	client_timeout_remove(client);
 	client->timeout_id=g_timeout_add(
-			(client==probe ? PROBE_TIMEOUT_SEC*1000 : CLIENT_TIMEOUT_SEC*1000),	/* interval; msec */
+			timeout_sec*1000,	/* interval; msec */
 			(GSourceFunc)client_touch_timeout,	/* function */
 			client);	/* data */
+	if (optarg_verbose)
+		g_message(_("Client fd %d new timeout id %d"),client->gpollfd.fd,client->timeout_id);
 	g_assert(client->timeout_id!=0);
 }
 
 static void client_destroy(struct client *client);
+static gboolean probe_send(struct client *probe,gint port_local);
 
 static gboolean client_touch_timeout(struct client *client)
 {
 	g_return_val_if_fail(client!=NULL,FALSE);	/* FALSE=>should be removed */
-	g_return_val_if_fail(client!=master,FALSE);	/* FALSE=>should be removed */
+	g_return_val_if_fail(client!=master_udp,FALSE);	/* FALSE=>should be removed */
+	g_return_val_if_fail(client!=master_tcp,FALSE);	/* FALSE=>should be removed */
+
+	if (optarg_verbose)
+		g_message(_("Client fd %d timeout id %d occured/entered"),client->gpollfd.fd,client->timeout_id);
+
+	/* Do not destroy the timeout in client_destroy().
+	 * It would crash GLib - we remove it be returning FALSE from here.
+	 */
+	g_assert(client->timeout_id!=0);
+	client->timeout_id=0;
 
 	if (client==probe) {
+		if (probe_timeout_sec_now<probe_timeout_sec_max) {
+			probe_timeout_sec_now*=PROBE_TIMEOUT_SEC_BASE;
+			g_assert(probe_timeout_sec_max==G_MAXUINT || probe_timeout_sec_max<PROBE_TIMEOUT_SEC_MAX);
+			probe_timeout_sec_now=MIN(probe_timeout_sec_now,probe_timeout_sec_max);
+			probe_timeout_sec_now=MIN(probe_timeout_sec_now,PROBE_TIMEOUT_SEC_MAX);
+			if (probe_send(probe,port_local)) {
+				client_touch(probe,probe_timeout_sec_now);	/* timeout */
+				return FALSE;	/* GSource should be removed */
+				}
+			/* failure FALLTHRU */
+			}
 		network_stop();
-		if (network_notify_hostip)
-			(*network_notify_hostip)(0,NULL);
+		/* Never destroy 'client' now - it has been destroyed by network_stop()! */
+		g_warning(_("No probe response from the server, stopping the daemon. Please check your public Internet connectivity."));
+		}
+	else {
+		client_destroy(client);
 		}
 
-	client_destroy(client);
+	if (optarg_verbose)
+		g_message(_("Client timeout occurance finish"));
 
 	return FALSE;	/* GSource should be removed */
 }
 
-static struct client *client_new(void);
+static void handle_master_probe(const void *packet,size_t gotlen,const struct sockaddr_in *sockaddr_in_from)
+{
+GHashTable *got_hash;
+gpointer got_unique_gpointer;
+gpointer hostip_gpointer;
+guint32 hostip_guint32;
+
+	g_return_if_fail(packet!=NULL);
+	g_return_if_fail(sockaddr_in_from!=NULL);
+
+	if (!probe)
+		return;
+
+	if (!(got_hash=packet_disassembly(packet,gotlen)))
+		return;
+	if (!(g_hash_table_lookup_extended(
+			got_hash,	/* hash_table */
+			GUINT_TO_POINTER(PACKET_ELEM_TYPE_DATA_GUINT32),	/* lookup_key */
+			NULL,	/* orig_key */
+			&got_unique_gpointer))) {
+err_packet_disassembly_destroy_got_hash:
+		packet_disassembly_destroy(got_hash);
+		return;
+		}
+	if (GPOINTER_TO_UINT(got_unique_gpointer)!=probe_unique)
+		goto err_packet_disassembly_destroy_got_hash;
+	if (!(g_hash_table_lookup_extended(
+			got_hash,	/* hash_table */
+			GUINT_TO_POINTER(PACKET_ELEM_TYPE_CLIENT_INADDR),	/* lookup_key */
+			NULL,	/* orig_key */
+			&hostip_gpointer)))
+		goto err_packet_disassembly_destroy_got_hash;
+	hostip_guint32=GPOINTER_TO_UINT(hostip_gpointer);
+	packet_disassembly_destroy(got_hash);
+
+	client_destroy(probe);
+	if (network_notify_hostip)
+		(*network_notify_hostip)(hostip_guint32);
+}
+
+enum client_new_type {
+	CLIENT_NEW_TYPE_UDP,
+	CLIENT_NEW_TYPE_TCP,
+	};
+
+static struct client *client_new(enum client_new_type type);
+static struct client *client_new_from_sock(int sock);
+
+static void clients_bind(struct client *client0,struct client *client1)
+{
+	g_return_if_fail(client0!=NULL);
+	g_return_if_fail(client0->bound==NULL);
+	g_return_if_fail(client0->gstring_to_send==NULL);
+	g_return_if_fail(client1!=NULL);
+	g_return_if_fail(client1->bound==NULL);
+	g_return_if_fail(client1->gstring_to_send==NULL);
+	g_return_if_fail(client0!=client1);
+
+	client0->bound=client1;
+	client1->bound=client0;
+
+	client0->gstring_to_send=g_string_sized_new(GSTRING_TO_SEND_MAX);
+	client1->gstring_to_send=g_string_sized_new(GSTRING_TO_SEND_MAX);
+}
+
+static void client_split(struct client *client)
+{
+	g_return_if_fail(client!=NULL);
+	g_return_if_fail(client->bound!=NULL);
+	g_return_if_fail(client->bound!=client);
+	g_return_if_fail(client->bound->bound==client);
+	g_return_if_fail(client->gstring_to_send!=NULL);
+
+	client->bound->bound=NULL;
+	client->bound=NULL;
+}
 
-static void handle_master(struct client *master)
+static struct sockaddr_in sockaddr_in_server;
+
+static void handle_master_udp(struct client *master_udp)
 {
+	g_return_if_fail(master_udp!=NULL);
+
+	for (;;) {
+char packet[0x10000];
 ssize_t gotlen;
 struct sockaddr_in sockaddr_in_from;
-char packet[0x10000];
-struct client *client;
-struct sockaddr_in sockaddr_in_server;
+struct client *client=NULL	/* Prevent false positive: might be used uninitialized */;
 socklen_t sockaddr_in_from_length;
-
-	g_return_if_fail(master!=NULL);
-
-	sockaddr_in_from_length=sizeof(sockaddr_in_from);
-	while (-1!=(gotlen=recvfrom(
-			master->gpollfd.fd,	/* s */
-			packet,	/* buf */
-			sizeof(packet),	/* len */
-			0,	/* flags */
-			(struct sockaddr *)&sockaddr_in_from,	/* from */
-			&sockaddr_in_from_length))) {	/* fromlen */
 GList *clientl;
 
+		sockaddr_in_from_length=sizeof(sockaddr_in_from);
+		if (-1==(gotlen=recvfrom(
+				master_udp->gpollfd.fd,	/* s */
+				packet,	/* buf */
+				sizeof(packet),	/* len */
+				0,	/* flags */
+				(struct sockaddr *)&sockaddr_in_from,	/* from */
+				&sockaddr_in_from_length)))	/* fromlen */
+			break;
+
 		if (sockaddr_in_from_length!=sizeof(sockaddr_in_from))	/* FIXME: errors reporting */
 			continue;
+
+		if (packet_recognized(packet,gotlen)) {
+			handle_master_probe(packet,gotlen,&sockaddr_in_from);
+			continue;
+			}
+		/* Not yet initialized by 'probe' reply - drop it. */
+		if (probe) {
+			if (optarg_verbose)
+				g_message(_("Data packet received from %s but no probe reply yet; dropping packet."),
+						SOCKADDR_IN_TO_STRING(&sockaddr_in_from));
+			continue;
+			}
+
 		/* FIXME: Performance: Ugly search... */
 		for (clientl=sock_client_list;clientl;clientl=clientl->next) {
 			client=clientl->data;
-			if (client==master)
+			if (client==master_udp)
 				continue;
 			if (1
 					&& client->sockaddr_in_from.sin_family     ==sockaddr_in_from.sin_family
@@ -205,14 +362,10 @@ GList *clientl;
 				break;
 			}
 		if (!clientl) {
-			client=client_new();
+			client=client_new(CLIENT_NEW_TYPE_UDP);
 			client->sockaddr_in_from=sockaddr_in_from;
 			}
-		client_touch(client);
-		UDPGATE_MEMZERO(&sockaddr_in_server);
-		sockaddr_in_server.sin_family=AF_INET;
-		sockaddr_in_server.sin_port=htons(SERVER_PORT);
-		sockaddr_in_server.sin_addr.s_addr=htonl(SERVER_INADDR);
+		client_touch(client,CLIENT_TIMEOUT_SEC);
 		/* FIXME: errors checking */
 		sendto(
 				client->gpollfd.fd,	/* s */
@@ -224,86 +377,117 @@ GList *clientl;
 		}
 }
 
-static void handle_probe(struct client *probe)
+static void handle_master_tcp(struct client *master_tcp)
 {
-ssize_t gotlen;
+	g_return_if_fail(master_tcp!=NULL);
+
+	for (;;) {
+int sock_new;
 struct sockaddr_in sockaddr_in_from;
-char packet[0x10000];
+struct client *client=NULL	/* Prevent false positive: might be used uninitialized */;
 socklen_t sockaddr_in_from_length;
+int connect_got;
+struct client *server;
 
-	g_return_if_fail(probe!=NULL);
-
-	sockaddr_in_from_length=sizeof(sockaddr_in_from);
-	while (-1!=(gotlen=recvfrom(
-			master->gpollfd.fd,	/* s */
-			packet,	/* buf */
-			sizeof(packet),	/* len */
-			0,	/* flags */
-			(struct sockaddr *)&sockaddr_in_from,	/* from */
-			&sockaddr_in_from_length))) {	/* fromlen */
-static GHashTable *got_hash;
-static gpointer got_unique_gpointer;
-static gpointer hostip_gpointer;
-static guint32 hostip_guint32;
+		sockaddr_in_from_length=sizeof(sockaddr_in_from);
+		if (-1==(sock_new=accept(
+				master_tcp->gpollfd.fd,	/* s */
+				(struct sockaddr *)&sockaddr_in_from,	/* from */
+				&sockaddr_in_from_length)))	/* fromlen */
+			break;
 
 		if (sockaddr_in_from_length!=sizeof(sockaddr_in_from))	/* FIXME: errors reporting */
 			continue;
-		if (!(got_hash=packet_disassembly(packet,gotlen)))
-			continue;
-		if (!(g_hash_table_lookup_extended(
-				got_hash,	/* hash_table */
-				GUINT_TO_POINTER(PACKET_ELEM_TYPE_DATA_GUINT32),	/* lookup_key */
-				NULL,	/* orig_key */
-				&got_unique_gpointer))) {
-err_packet_disassembly_destroy_got_hash:
-			packet_disassembly_destroy(got_hash);
+
+		/* Not yet initialized by 'probe' reply - drop it. */
+		if (probe) {
+			if (optarg_verbose)
+				g_message(_("Incoming connection received from %s but no probe reply yet; dropping connection."),
+						SOCKADDR_IN_TO_STRING(&sockaddr_in_from));
+			close(sock_new);	/* FIXME: errors reporting */
 			continue;
 			}
-		if (GPOINTER_TO_UINT(got_unique_gpointer)!=probe_unique)
-			goto err_packet_disassembly_destroy_got_hash;
-		if (!(g_hash_table_lookup_extended(
-				got_hash,	/* hash_table */
-				GUINT_TO_POINTER(PACKET_ELEM_TYPE_CLIENT_INADDR),	/* lookup_key */
-				NULL,	/* orig_key */
-				&hostip_gpointer)))
-			goto err_packet_disassembly_destroy_got_hash;
-		hostip_guint32=GPOINTER_TO_UINT(hostip_gpointer);
-		packet_disassembly_destroy(got_hash);
 
-		client_destroy(probe);
-		if (network_notify_hostip)
-			(*network_notify_hostip)(hostip_guint32,
-					udpgate_printf_alloca("%d.%d.%d.%d",
-							(hostip_guint32>>24U)&0xFFU,
-							(hostip_guint32>>16U)&0xFFU,
-							(hostip_guint32>> 8U)&0xFFU,
-							(hostip_guint32>> 0U)&0xFFU));
+		if (!(client=client_new_from_sock(sock_new)))
+			continue;
+		client->sockaddr_in_from=sockaddr_in_from;
+
+		if (!(server=client_new(CLIENT_NEW_TYPE_TCP))) {
+			client_destroy(client);
+			continue;
+			}
+		server->server_only=1;
+		server->sockaddr_in_from=sockaddr_in_server;
+		clients_bind(client,server);
+		/* Currently only one of 'client' or 'server' needs to be destroyed. */
+
+		errno=0;
+		connect_got=connect(
+				server->gpollfd.fd,	/* sockfd */
+				(struct sockaddr *)&sockaddr_in_server,	/* to */
+				sizeof(sockaddr_in_server));	/* tolen */
+		if (connect_got!=-1 || errno!=EINPROGRESS) {
+			g_warning(_("Error establishing server TCP connection: %m"));
+			client_destroy(server);
+			continue;
+			}
+		g_assert(!server->connect_pending);
+		server->connect_pending=1;
 		}
 }
 
-static void handle_client(struct client *client)
+static void handle_probe(struct client *probe)
 {
+	g_return_if_fail(probe!=NULL);
+
+	for (;;) {
 ssize_t gotlen;
 struct sockaddr_in sockaddr_in_from;
-char packet [0x10000];
+char packet[0x10000];
 socklen_t sockaddr_in_from_length;
 
+		sockaddr_in_from_length=sizeof(sockaddr_in_from);
+		if (-1==(gotlen=recvfrom(
+				master_udp->gpollfd.fd,	/* s */
+				packet,	/* buf */
+				sizeof(packet),	/* len */
+				0,	/* flags */
+				(struct sockaddr *)&sockaddr_in_from,	/* from */
+				&sockaddr_in_from_length)))	/* fromlen */
+			break;
+		if (sockaddr_in_from_length!=sizeof(sockaddr_in_from))	/* FIXME: errors reporting */
+			continue;
+
+		/* Probe socket should have no response; maybe some ICMP errors - ignored. */
+		}
+}
+
+static void handle_client_udp(struct client *client)
+{
 	g_return_if_fail(client!=NULL);
-	g_return_if_fail(master!=NULL);
+	g_return_if_fail(master_udp!=NULL);
 
-	while (-1!=(gotlen=recvfrom(
-			client->gpollfd.fd,	/* s */
-			packet,	/* buf */
-			sizeof(packet),	/* len */
-			0,	/* flags */
-			(struct sockaddr *)&sockaddr_in_from,	/* from */
-			&sockaddr_in_from_length))) {	/* fromlen */
+	for (;;) {
+ssize_t gotlen;
+struct sockaddr_in sockaddr_in_from;
+char packet[0x10000];
+socklen_t sockaddr_in_from_length;
+
+		sockaddr_in_from_length=sizeof(sockaddr_in_from);
+		if (-1==(gotlen=recvfrom(
+				client->gpollfd.fd,	/* s */
+				packet,	/* buf */
+				sizeof(packet),	/* len */
+				0,	/* flags */
+				(struct sockaddr *)&sockaddr_in_from,	/* from */
+				&sockaddr_in_from_length)))	/* fromlen */
+			break;
 		if (sockaddr_in_from_length!=sizeof(sockaddr_in_from))	/* FIXME: errors reporting */
 			continue;
-		client_touch(client);
+		client_touch(client,CLIENT_TIMEOUT_SEC);
 		/* FIXME: errors checking */
 		sendto(
-				master->gpollfd.fd,	/* s */
+				master_udp->gpollfd.fd,	/* s */
 				packet,	/* msg */
 				gotlen,	/* len */
 				0,	/* flags */
@@ -312,21 +496,156 @@ socklen_t sockaddr_in_from_length;
 		}
 }
 
+static void handle_client_tcp_connect(struct client *server)
+{
+	g_return_if_fail(server!=NULL);
+	g_return_if_fail(server->connect_pending);
+	g_return_if_fail(master_tcp!=NULL);
+
+	errno=0;
+	if (connect(
+			server->gpollfd.fd,	/* sockfd */
+			(struct sockaddr *)&sockaddr_in_server,	/* to */
+			sizeof(sockaddr_in_server))) {	/* tolen */
+		g_warning(_("Error establishing server TCP connection: %m"));
+		client_destroy(server);
+		return;
+		}
+	g_assert(server->connect_pending);
+	server->connect_pending=0;
+}
+
+/* Read from client->gpollfd.fd the data for client->bound->gstring_to_send. */
+static void handle_client_tcp_read(struct client *client)
+{
+	g_return_if_fail(client!=NULL);
+	g_return_if_fail(client->bound!=NULL);
+	g_return_if_fail(!client->connect_pending);
+	g_return_if_fail(master_tcp!=NULL);
+
+	for (;;) {
+ssize_t gotlen;
+size_t read_max;
+char buf[GSTRING_TO_SEND_MAX];
+
+		read_max=sizeof(buf)-client->bound->gstring_to_send->len;
+		g_assert(read_max>=0);
+		if (read_max<=0)	/* In fact it initially should not happen, there would be no: G_IO_IN */
+			break;
+		gotlen=read(client->gpollfd.fd,buf,read_max);
+		if (gotlen==-1) {
+			if (errno==EAGAIN)
+				break;
+			g_warning(_("Error reading data from %s"),SOCKADDR_IN_TO_STRING(&client->sockaddr_in_from));
+			client_destroy(client);
+			return;
+			}
+		if (gotlen==0) {
+			/* Successful close; leave the bound peer's 'gstring_to_send' to be written there. */
+			if (client->server_only && client->bound->gstring_to_send->len)
+				client_split(client);
+			client_destroy(client);
+			return;
+			}
+		g_assert(gotlen>0);
+		g_assert((size_t)gotlen<=read_max);
+		g_string_append_len(client->bound->gstring_to_send,buf,gotlen);
+		}
+}
+
+/* Write to client->gpollfd.fd the data from client->gstring_to_send. */
+static void handle_client_tcp_write(struct client *client)
+{
+	g_return_if_fail(client!=NULL);
+	g_return_if_fail(!client->connect_pending);
+	g_return_if_fail(master_tcp!=NULL);
+
+	for (;;) {
+ssize_t gotlen;
+
+		if (client->gstring_to_send->len<=0)	/* In fact it initially should not happen, there would be no: G_IO_OUT */
+			break;
+		gotlen=write(client->gpollfd.fd,client->gstring_to_send->str,client->gstring_to_send->len);
+		if (gotlen==-1) {
+			if (errno==EAGAIN)
+				break;
+			g_warning(_("Error writing data to %s"),SOCKADDR_IN_TO_STRING(&client->sockaddr_in_from));
+			client_destroy(client);
+			return;
+			}
+		if (gotlen<=0)
+			break;
+		g_assert((size_t)gotlen<=client->gstring_to_send->len);
+		g_string_erase(client->gstring_to_send,0,gotlen);
+		}
+
+	/* Nothing left to do for such client. */
+	if (!client->gstring_to_send->len && !client->bound)
+		client_destroy(client);
+}
+
 static gboolean sock_source_callback(gpointer data /* unused */)
 {
 GList *clientl;
 
+	/* FIXME: Quadratic 'done' marking to not to stick on stale entry! */
+
 	for (clientl=sock_client_list;clientl;clientl=clientl->next) {
 struct client *client=clientl->data;
 
-		if (client->gpollfd.revents&SOCK_SOURCE_CHECK_REVENTS) {
-			/**/ if (client==master)
-				handle_master(client);
+		client->done=0;
+		}
+retry_in:
+	for (clientl=sock_client_list;clientl;clientl=clientl->next) {
+struct client *client=clientl->data;
+
+		if (client->done)
+			continue;
+		client->done=1;
+		if (client->gpollfd.revents&G_IO_IN) {
+			/**/ if (client==master_udp)
+				handle_master_udp(client);
+			else if (client==master_tcp)
+				handle_master_tcp(client);
 			else if (client==probe)
 				handle_probe(client);
+			else if (client->connect_pending)
+				g_assert_not_reached();
+			else if (client->bound)
+				handle_client_tcp_read(client);
 			else
-				handle_client(client);
+				handle_client_udp(client);
 			}
+		goto retry_in;
+		}
+
+	for (clientl=sock_client_list;clientl;clientl=clientl->next) {
+struct client *client=clientl->data;
+
+		client->done=0;
+		}
+retry_out:
+	for (clientl=sock_client_list;clientl;clientl=clientl->next) {
+struct client *client=clientl->data;
+
+		if (client->done)
+			continue;
+		client->done=1;
+		if (client->gpollfd.revents&G_IO_OUT) {
+			/**/ if (client==master_udp)
+				g_assert_not_reached();
+			else if (client==master_tcp)
+				g_assert_not_reached();
+			else if (client==probe)
+				g_assert_not_reached();
+			else if (client->connect_pending)
+				handle_client_tcp_connect(client);
+			else if (client->gstring_to_send)
+				handle_client_tcp_write(client);
+			else
+				g_assert_not_reached();
+			}
+		goto retry_out;
 		}
 
 	return TRUE; /* the source should be kept active */
@@ -334,8 +653,28 @@ struct client *client=clientl->data;
 
 static gboolean sock_source_prepare(GSource *source,gint *timeout)
 {
+GList *clientl;
+
 	*timeout=-1;
 
+	for (clientl=sock_client_list;clientl;clientl=clientl->next) {
+struct client *client=clientl->data;
+
+		client->gpollfd.events=G_IO_IN;
+		if (!client->bound && client->gstring_to_send)
+			client->gpollfd.events&=~G_IO_IN;
+		if (client->bound && client->bound->gstring_to_send->len>=GSTRING_TO_SEND_MAX)
+			client->gpollfd.events&=~G_IO_IN;
+		if (client->connect_pending)
+			client->gpollfd.events&=~G_IO_IN;
+		if (client->bound && client->bound->connect_pending)
+			client->gpollfd.events&=~G_IO_IN;
+		if (client->connect_pending)
+			client->gpollfd.events|=G_IO_OUT;
+		if (client->gstring_to_send && client->gstring_to_send->len>0)
+			client->gpollfd.events|=G_IO_OUT;
+		g_assert(!(client->gpollfd.events&~SOCK_SOURCE_CHECK_REVENTS));
+		}
 	return FALSE;
 }
 
@@ -370,14 +709,16 @@ static void sock_gsource_destroy(void)
 	while (sock_client_list)
 		client_destroy(sock_client_list->data);
 
-	g_assert(master==NULL);
+	g_assert(master_udp==NULL);
+	g_assert(master_tcp==NULL);
+	g_assert(probe==NULL);
 
 	if (sock_gsource) {
 		g_source_destroy(sock_gsource);
 		sock_gsource=NULL;
 		}
 
-	write_daemon_running((pid_t)-1);	/* unlink */
+	write_daemon_running((pid_t)-1);	/* unlink; errors ignored */
 }
 
 static gboolean sock_gsource_new(void)
@@ -409,19 +750,16 @@ static gboolean sock_gsource_new(void)
 	return TRUE;
 }
 
-static struct client *client_new(void)
+static struct client *client_new_from_sock(int sock)
 {
 struct client *client;
 static unsigned long oneul=1;
-int sock;
+
+	g_return_val_if_fail(sock>=0,NULL);
 
 	if (!sock_gsource_new())
 		return FALSE;
 
-	if (-1==(sock=socket(AF_INET,SOCK_DGRAM,0))) {
-		g_warning("socket(AF_INET,SOCK_DGRAM): %m");
-		return NULL;
-		}
 	if (ioctl(sock,FIONBIO,&oneul)) {	/* non-blocking mode */
 		g_warning("ioctl(sock,FIONBIO,&1): %m");
 		close(sock);	/* errors ignored */
@@ -430,24 +768,63 @@ int sock;
 
 	udpgate_new(client);
 	client->gpollfd.fd=sock;
-	client->gpollfd.events=SOCK_SOURCE_CHECK_EVENTS;
-	client->gpollfd.revents=0;
+	client->gpollfd.events=0;	/* Initialized later. */
+	client->gpollfd.revents=0;	/* Probably does not need to be initialized. */
 	client->timeout_id=0;
+	client->bound=NULL;
+	client->connect_pending=0;
+	client->server_only=0;
+	client->gstring_to_send=0;
 	sock_client_list=g_list_prepend(sock_client_list,client);
 	g_source_add_poll(sock_gsource,&client->gpollfd);
 
+	if (optarg_verbose)
+		g_message(_("Client fd %d created"),client->gpollfd.fd);
+
 	return client;
 }
 
+static struct client *client_new(enum client_new_type type)
+{
+int sock;
+
+	switch (type) {
+		case CLIENT_NEW_TYPE_UDP:
+			if (-1==(sock=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP))) {
+				g_warning("socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP): %m");
+				return NULL;
+				}
+			break;
+		case CLIENT_NEW_TYPE_TCP:
+			if (-1==(sock=socket(PF_INET,SOCK_STREAM,IPPROTO_TCP))) {
+				g_warning("socket(PF_INET,SOCK_STREAM,IPPROTO_TCP): %m");
+				return NULL;
+				}
+			break;
+		default: g_assert_not_reached();
+		}
+
+	return client_new_from_sock(sock);
+}
+
 static void client_destroy(struct client *client)
 {
+struct client *bound;
+
 	g_return_if_fail(client!=NULL);
 
 	if (!sock_gsource_new())
 		return;
 
-	if (client==master) {
-		master=NULL;
+	if (optarg_verbose)
+		g_message(_("Client fd %d timeout id %d destroy enter"),client->gpollfd.fd,client->timeout_id);
+
+	if (client==master_udp) {
+		master_udp=NULL;
+		g_assert(client->timeout_id==0);
+		}
+	else if (client==master_tcp) {
+		master_tcp=NULL;
 		g_assert(client->timeout_id==0);
 		}
 	else {
@@ -459,12 +836,28 @@ static void client_destroy(struct client *client)
 	g_source_remove_poll(sock_gsource,&client->gpollfd);
 	sock_client_list=g_list_remove(sock_client_list,client);
 	close(client->gpollfd.fd);	/* errors ignored */
+
+	if (client->gstring_to_send)
+		g_string_free(client->gstring_to_send,TRUE);
+
+	if (optarg_verbose)
+		g_message(_("Client fd %d timeout id %d destroy finish"),client->gpollfd.fd,client->timeout_id);
+
+	bound=client->bound;
 	g_free(client);
+
+	if (bound) {
+		g_assert(bound!=client);
+		g_assert(bound->bound==client);
+		client->bound=NULL;
+		bound->bound=NULL;
+		client_destroy(bound);
+		}
 }
 
 static gboolean probe_send(struct client *probe,gint port_local)
 {
-struct sockaddr_in sockaddr_in_server;
+struct sockaddr_in sockaddr_in_probe;
 GHashTable *probe_hash;
 gpointer packet;
 size_t packet_length;
@@ -474,8 +867,8 @@ size_t packet_length;
 	probe_unique=g_random_int();
 
 	probe_hash=g_hash_table_new(
-			g_int_hash,	/* hash_func */
-			g_int_equal);	/* key_equal_func */
+			g_direct_hash,	/* hash_func */
+			g_direct_equal);	/* key_equal_func */
 	g_hash_table_insert(probe_hash,GUINT_TO_POINTER(PACKET_ELEM_TYPE_CLIENT_PORT) ,GUINT_TO_POINTER(port_local));
 	g_hash_table_insert(probe_hash,GUINT_TO_POINTER(PACKET_ELEM_TYPE_DATA_GUINT32),GUINT_TO_POINTER(probe_unique));
 	packet=packet_assembly(&packet_length,probe_hash);
@@ -483,56 +876,150 @@ size_t packet_length;
 	if (!packet)
 		return FALSE;
 
-	UDPGATE_MEMZERO(&sockaddr_in_server);
-	sockaddr_in_server.sin_family=AF_INET;
-	sockaddr_in_server.sin_port=htons(PROBE_PORT);
-	sockaddr_in_server.sin_addr.s_addr=htonl(PROBE_INADDR);
+	UDPGATE_MEMZERO(&sockaddr_in_probe);
+	sockaddr_in_probe.sin_family=AF_INET;
+	sockaddr_in_probe.sin_port=htons(PROBE_PORT);
+	sockaddr_in_probe.sin_addr.s_addr=htonl(PROBE_INADDR);
 	/* FIXME: errors checking */
 	sendto(
 			probe->gpollfd.fd,	/* s */
 			packet,	/* msg */
 			packet_length,	/* len */
 			0,	/* flags */
-			(struct sockaddr *)&sockaddr_in_server,	/* to */
-			sizeof(sockaddr_in_server));	/* tolen */
+			(struct sockaddr *)&sockaddr_in_probe,	/* to */
+			sizeof(sockaddr_in_probe));	/* tolen */
+
+	return TRUE;
+}
+
+static gboolean master_udp_start(gint port,const struct sockaddr_in *sockaddr_in_pointer)
+{
+	g_return_val_if_fail(master_udp==NULL,FALSE);
+
+	if (!(master_udp=client_new(CLIENT_NEW_TYPE_UDP)))
+		return FALSE;
+	if (bind(master_udp->gpollfd.fd,(struct sockaddr *)sockaddr_in_pointer,sizeof(*sockaddr_in_pointer))) {
+		g_warning("bind(sock_udp,{AF_INET,INADDR_ANY:%d}): %m",(int)port);
+		return FALSE;
+		}
+	return TRUE;
+}
+
+static gboolean master_tcp_start(gint port,const struct sockaddr_in *sockaddr_in_pointer)
+{
+static int onei=1;
+
+	g_return_val_if_fail(master_tcp==NULL,FALSE);
+
+	if (!(master_tcp=client_new(CLIENT_NEW_TYPE_TCP)))
+		return FALSE;
+	if (setsockopt(master_tcp->gpollfd.fd,SOL_SOCKET,SO_REUSEADDR,&onei,sizeof(onei))) {
+		g_warning("setsockopt(sock_tcp,SOL_SOCKET,SO_REUSEADDR,1): %m");
+		return FALSE;
+		}
+	if (bind(master_tcp->gpollfd.fd,(struct sockaddr *)sockaddr_in_pointer,sizeof(*sockaddr_in_pointer))) {
+		g_warning("bind(sock_tcp,{AF_INET,INADDR_ANY:%d}): %m",(int)port);
+		return FALSE;
+		}
+	if (listen(master_tcp->gpollfd.fd,TCP_BACKLOG)) {
+		g_warning("listen(sock_tcp,%d): %m",TCP_BACKLOG);
+		return FALSE;
+		}
+	return TRUE;
+}
+
+static gboolean master_start(gint port)
+{
+struct sockaddr_in sockaddr_in;
+uint16_t port_use;
+
+	g_return_val_if_fail(port>=0,FALSE);
+	g_return_val_if_fail(master_udp==NULL,FALSE);
+	g_return_val_if_fail(master_tcp==NULL,FALSE);
+
+	port_use=port;
+	if (port < 0 || port_use != port) {
+		g_warning(_("Port value %d is not valid for IPv4!"),(int)port);
+		return FALSE;
+		}
+	UDPGATE_MEMZERO(&sockaddr_in);
+	sockaddr_in.sin_family=AF_INET;
+	sockaddr_in.sin_port=htons(port_use);
+	sockaddr_in.sin_addr.s_addr=htonl(INADDR_ANY);
+
+	if (!master_udp_start(port,&sockaddr_in))
+		return FALSE;
+	if (!master_tcp_start(port,&sockaddr_in)) {
+		client_destroy(master_udp);
+		return FALSE;
+		}
+	return TRUE;
+}
 
+static gboolean probe_start(gint port)
+{
+	g_return_val_if_fail(port>=0,FALSE);
+	g_return_val_if_fail(probe==NULL,FALSE);
+
+	/* Setup 'probe': */
+	if (!(probe=client_new(CLIENT_NEW_TYPE_UDP)))
+		return FALSE;
+	port_local=port;
+	if (!probe_send(probe,port)) {
+		client_destroy(probe);
+		return FALSE;
+		}
+	probe_timeout_sec_now=PROBE_TIMEOUT_SEC_BASE;
+	client_touch(probe,probe_timeout_sec_now);	/* timeout */
 	return TRUE;
 }
 
 gboolean network_start(gint port)
 {
 pid_t daemon_pid;
-struct sockaddr_in sockaddr_in;
 
 	g_return_val_if_fail(port>=0,FALSE);
 
+	UDPGATE_MEMZERO(&sockaddr_in_server);
+	sockaddr_in_server.sin_family=AF_INET;
+	sockaddr_in_server.sin_port=htons(SERVER_PORT);
+	sockaddr_in_server.sin_addr.s_addr=htonl(SERVER_INADDR);
+
 	if ((pid_t)-1!=(daemon_pid=is_daemon_running())) {
 		g_warning(_("Cannot start network daemon: Daemon is already running on PID %d"),(int)daemon_pid);
 		return FALSE;
 		}
-
-	/* Setup 'master': */
-	g_assert(master==NULL);
-	if (!(master=client_new()))
+	if (!master_start(port)) {
+		sock_gsource_destroy();
 		return FALSE;
-	UDPGATE_MEMZERO(&sockaddr_in);
-	sockaddr_in.sin_family=AF_INET;
-	sockaddr_in.sin_port=htons(port);
-	sockaddr_in.sin_addr.s_addr=INADDR_ANY;
-	if (bind(master->gpollfd.fd,(struct sockaddr *)&sockaddr_in,sizeof(sockaddr_in))) {
-		g_warning("bind(sock,{AF_INET,INADDR_ANY:%d}): %m",(int)port);
-err_sock_gsource_destroy:
+		}
+	if (!probe_start(port)) {
 		sock_gsource_destroy();
 		return FALSE;
 		}
+	write_daemon_running(getpid());	/* errors ignored */
+	if (network_notify_hostip)
+		(*network_notify_hostip)(0);
+	return TRUE;
+}
 
-	/* Setup 'probe': */
-	if (!(probe=client_new()))
-		goto err_sock_gsource_destroy;
-	probe_send(probe,port);
-	client_touch(probe);	/* timeout */
+gboolean optarg_port_set_string(const gchar *port_string)
+{
+char *endp;
+long port_long;
+
+	g_return_val_if_fail(port_string!=NULL,FALSE);
 
-	write_daemon_running(getpid());
+	port_long=strtol(port_string,&endp,0);
+	if (endp && *endp) {
+		g_warning(_("Invalid port specification, offending string: %s"),endp);
+		return FALSE;
+		}
+	if (port_long<1 || port_long>=G_MAXINT || (endp && *endp)) {
+		g_warning(_("Invalid port integer number specification (%ld)"),port_long);
+		return FALSE;
+		}
+	optarg_port=port_long;
 	return TRUE;
 }
 
@@ -547,15 +1034,61 @@ int errno_save;
 		}
 	if (daemon_pid==getpid()) {
 		sock_gsource_destroy();
-		return TRUE;
+		goto ok;
 		}
 	errno=0;
 	kill(daemon_pid,SIGKILL);
 	errno_save=errno;
+	write_daemon_running((pid_t)-1);	/* unlink; errors ignored */
 	if (errno_save)  {
 		g_warning(udpgate_printf_alloca(_("Unable to stop the daemon at PID %d: %s"),
 				(int)daemon_pid,strerror(errno_save)));
 		return FALSE;
 		}
+ok:
+	if (network_notify_hostip)
+		(*network_notify_hostip)(0);
 	return TRUE;
 }
+
+static GMainLoop *gmainloop;
+static void network_detach_network_notify_hostip(guint32 hostip_guint32)
+{
+	if (!hostip_guint32)
+		g_main_loop_quit(gmainloop);
+}
+
+gboolean network_detach(void)
+{
+pid_t daemon_pid,forked_pid;
+
+	if ((pid_t)-1==(daemon_pid=is_daemon_running()))
+		return TRUE;
+	if (getpid()!=daemon_pid)
+		return TRUE;
+	if (!optarg_no_fork) {
+		if ((pid_t)-1==(forked_pid=fork())) {
+			g_warning("fork(2): %m");
+			return FALSE;
+			}
+		if (forked_pid) {
+			/* parent */
+			return TRUE;
+			}
+		write_daemon_running(getpid());	/* errors ignored */
+		optarg_verbose=0;
+		close(STDIN_FILENO);
+		close(STDOUT_FILENO);
+		close(STDERR_FILENO);
+		setpgrp();
+		setsid();
+		}
+
+	network_notify_hostip=network_detach_network_notify_hostip;
+	gmainloop=g_main_loop_new(
+			NULL,	/* context */
+			TRUE);	/* is_running; ignored */
+	g_main_loop_run(gmainloop);	/* loop */
+	/* Unable to contact the server, aborting. */
+	return FALSE;
+}