return error when random port pool is empty

fixes #232

src/host/shd-host.c

@@ -664,22 +664,24 @@ static gboolean _host_isInterfaceAvailable(Host* host, in_addr_t interfaceIP,
 }
 
 
-static in_port_t _host_getRandomFreePort(Host* host, in_addr_t interfaceIP,
-		DescriptorType type) {
-	MAGIC_ASSERT(host);
-
-	in_port_t randomNetworkPort = 0;
-	gboolean available = FALSE;
+static in_port_t _host_getRandomFreePort(Host* host, in_addr_t interfaceIP, DescriptorType type) {
+    MAGIC_ASSERT(host);
 
-	while(!available) {
-		gdouble randomFraction = random_nextDouble(host->random);
-		in_port_t randomHostPort = (in_port_t) (randomFraction * (UINT16_MAX - MIN_RANDOM_PORT)) + MIN_RANDOM_PORT;
-		utility_assert(randomHostPort >= MIN_RANDOM_PORT);
-		randomNetworkPort = htons(randomHostPort);
-		available = _host_isInterfaceAvailable(host, interfaceIP, type, randomNetworkPort);
-	}
+    NetworkInterface* interface = host_lookupInterface(host, interfaceIP);
+    in_port_t randomNetworkPort = 0;
+
+    if (interface && networkinterface_hasFreePorts(interface)) {
+        gboolean freePortFound = FALSE;
+        while (!freePortFound) {
+            gdouble randomFraction = random_nextDouble(host->random);
+            in_port_t randomHostPort = (in_port_t) (randomFraction * (UINT16_MAX - MIN_RANDOM_PORT)) + MIN_RANDOM_PORT;
+            utility_assert(randomHostPort >= MIN_RANDOM_PORT);
+            randomNetworkPort = htons(randomHostPort);
+            freePortFound = _host_isInterfaceAvailable(host, interfaceIP, type, randomNetworkPort);
+        }
+    }
 
-	return randomNetworkPort;
+    return randomNetworkPort;
 }
 
 gint host_bindToInterface(Host* host, gint handle, const struct sockaddr* address) {
@@ -737,6 +739,9 @@ gint host_bindToInterface(Host* host, gint handle, const struct sockaddr* addres
 	if(bindPort == 0) {
 		/* we know it will be available */
 		bindPort = _host_getRandomFreePort(host, bindAddress, type);
+		if(!bindPort) {
+		    return EADDRNOTAVAIL;
+		}
 	} else {
 		/* make sure their port is available at that address for this protocol. */
 		if(!_host_isInterfaceAvailable(host, bindAddress, type, bindPort)) {
@@ -842,6 +847,9 @@ gint host_connectToPeer(Host* host, gint handle, const struct sockaddr* address)
 
 		in_addr_t bindAddress = loIP == peerIP ? loIP : defaultIP;
 		in_port_t bindPort = _host_getRandomFreePort(host, bindAddress, type);
+        if(!bindPort) {
+            return EADDRNOTAVAIL;
+        }
 
 		_host_associateInterface(host, socket, bindAddress, bindPort);
 	}
@@ -877,6 +885,9 @@ gint host_listenForPeer(Host* host, gint handle, gint backlog) {
 		/* implicit bind */
 		in_addr_t bindAddress = htonl(INADDR_ANY);
 		in_port_t bindPort = _host_getRandomFreePort(host, bindAddress, type);
+        if(!bindPort) {
+            return EADDRNOTAVAIL;
+        }
 
 		_host_associateInterface(host, socket, bindAddress, bindPort);
 	}
@@ -1059,6 +1070,9 @@ gint host_sendUserData(Host* host, gint handle, gconstpointer buffer, gsize nByt
 			in_addr_t bindAddress = ip == htonl(INADDR_LOOPBACK) ? htonl(INADDR_LOOPBACK) :
 					networkinterface_getIPAddress(host->defaultInterface);
 			in_port_t bindPort = _host_getRandomFreePort(host, bindAddress, type);
+	        if(!bindPort) {
+	            return EADDRNOTAVAIL;
+	        }
 
 			/* bind port and set associations */
 			_host_associateInterface(host, socket, bindAddress, bindPort);

src/host/shd-network-interface.c

@@ -224,6 +224,11 @@ gboolean networkinterface_isAssociated(NetworkInterface* interface, gint key) {
 	}
 }
 
+gboolean networkinterface_hasFreePorts(NetworkInterface* interface) {
+    MAGIC_ASSERT(interface);
+    return g_hash_table_size(interface->boundSockets) < (UINT16_MAX - MIN_RANDOM_PORT) ? TRUE : FALSE;
+}
+
 void networkinterface_associate(NetworkInterface* interface, Socket* socket) {
 	MAGIC_ASSERT(interface);
 

src/host/shd-network-interface.h

@@ -24,6 +24,7 @@ guint32 networkinterface_getSpeedDownKiBps(NetworkInterface* interface);
 gboolean networkinterface_isAssociated(NetworkInterface* interface, gint key);
 void networkinterface_associate(NetworkInterface* interface, Socket* transport);
 void networkinterface_disassociate(NetworkInterface* interface, Socket* transport);
+gboolean networkinterface_hasFreePorts(NetworkInterface* interface);
 
 void networkinterface_packetArrived(NetworkInterface* interface, Packet* packet);
 void networkinterface_packetDropped(NetworkInterface* interface, Packet* packet);