package org.jgroups.protocols;
import org.jgroups.Event;
import org.jgroups.Global;
import org.jgroups.Message;
import org.jgroups.annotations.LocalAddress;
import org.jgroups.annotations.Property;
import org.jgroups.conf.PropertyConverters;
import org.jgroups.util.*;
import java.io.*;
import java.net.*;
import java.util.*;
/**
* Uses its own IP multicast socket to send and receive discovery requests/responses. Can be used in
* conjuntion with a non-UDP transport, e.g. TCP.<p>
* The discovery is <em>asymmetric</em>: discovery requests are broadcast via the multicast socket, and received via the
* multicast socket by everyone in the group. However, the discovery responses are sent back via the regular transport
* (e.g. TCP) to the sender (discovery request contained sender's regular address, e.g. 192.168.0.2:7800).
* @author Bela Ban
*/
public class MPING extends PING implements Runnable {
protected static final boolean can_bind_to_mcast_addr; // are we running on Linux ?
static {
can_bind_to_mcast_addr=(Util.checkForLinux() && !Util.checkForAndroid())
|| Util.checkForSolaris() || Util.checkForHp();
}
/* ----------------------------------------- Properties -------------------------------------------------- */
@LocalAddress
@Property(description="Bind address for multicast socket. " +
"The following special values are also recognized: GLOBAL, SITE_LOCAL, LINK_LOCAL and NON_LOOPBACK",
systemProperty={Global.BIND_ADDR})
protected InetAddress bind_addr;
@Property(name="bind_interface", converter=PropertyConverters.BindInterface.class,
description="The interface (NIC) which should be used by this transport",dependsUpon="bind_addr")
protected String bind_interface_str;
@Property(description="Time to live for discovery packets. Default is 8", systemProperty=Global.MPING_IP_TTL)
protected int ip_ttl=8;
@Property(description="Multicast address to be used for discovery", name="mcast_addr", systemProperty=Global.MPING_MCAST_ADDR,
defaultValueIPv4="230.5.6.7", defaultValueIPv6="ff0e::5:6:7")
protected InetAddress mcast_addr;
@Property(description="Multicast port for discovery packets. Default is 7555", systemProperty=Global.MPING_MCAST_PORT)
protected int mcast_port=7555;
@Property(description="If true, the transport should use all available interfaces to receive multicast messages")
protected boolean receive_on_all_interfaces;
/**
* List<NetworkInterface> of interfaces to receive multicasts on. The
* multicast receive socket will listen on all of these interfaces. This is
* a comma-separated list of IP addresses or interface names. E.g.
* "192.168.5.1,eth1,127.0.0.1". Duplicates are discarded; we only bind to
* an interface once. If this property is set, it override
* receive_on_all_interfaces.
*/
@Property(converter=PropertyConverters.NetworkInterfaceList.class, description="List of interfaces to receive multicasts on")
protected List<NetworkInterface> receive_interfaces;
/**
* If true, the transport should use all available interfaces to send
* multicast messages. This means the same multicast message is sent N
* times, so use with care
*/
@Property(description="Whether send messages are sent on all interfaces. Default is false")
protected boolean send_on_all_interfaces;
/**
* List<NetworkInterface> of interfaces to send multicasts on. The multicast send socket will send the same multicast
* message on all of these interfaces. This is a comma-separated list of IP addresses or interface names.
* E.g. "192.168.5.1,eth1,127.0.0.1". Duplicates are discarded. If this property is set, it override send_on_all_interfaces.
*/
@Property(converter=PropertyConverters.NetworkInterfaceList.class, description="List of interfaces to send multicasts on")
protected List<NetworkInterface> send_interfaces;
/* --------------------------------------------- Fields ------------------------------------------------------ */
protected MulticastSocket mcast_sock;
/** If we have multiple mcast send sockets, e.g. send_interfaces or send_on_all_interfaces enabled */
protected MulticastSocket[] mcast_send_sockets;
protected volatile Thread receiver;
public MPING() {
}
public InetAddress getBindAddr() {
return bind_addr;
}
public void setBindAddr(InetAddress bind_addr) {
this.bind_addr=bind_addr;
}
public List<NetworkInterface> getReceiveInterfaces() {
return receive_interfaces;
}
public List<NetworkInterface> getSendInterfaces() {
return send_interfaces;
}
public boolean isReceiveOnAllInterfaces() {
return receive_on_all_interfaces;
}
public boolean isSendOnAllInterfaces() {
return send_on_all_interfaces;
}
public int getTTL() {
return ip_ttl;
}
public void setTTL(int ip_ttl) {
this.ip_ttl=ip_ttl;
}
public InetAddress getMcastAddr() {
return mcast_addr;
}
public void setMcastAddr(InetAddress mcast_addr) {
this.mcast_addr=mcast_addr;
}
public void setMulticastAddress(String addr) throws UnknownHostException {
mcast_addr=InetAddress.getByName(addr);
}
public int getMcastPort() {
return mcast_port;
}
public void setMcastPort(int mcast_port) {
this.mcast_port=mcast_port;
}
@SuppressWarnings("unchecked")
public Object up(Event evt) {
if(evt.getType() == Event.CONFIG) {
if(bind_addr == null) {
Map<String,Object> config=evt.getArg();
bind_addr=(InetAddress)config.get("bind_addr");
}
return up_prot.up(evt);
}
return super.up(evt);
}
public void init() throws Exception {
super.init();
log.debug("bind_addr=%s, mcast_addr=%s, mcast_port=%d", bind_addr, mcast_addr, mcast_port);
}
public void start() throws Exception {
if(can_bind_to_mcast_addr) // https://jira.jboss.org/jira/browse/JGRP-836 - prevent cross talking on Linux
mcast_sock=Util.createMulticastSocket(getSocketFactory(), "jgroups.mping.mcast_sock", mcast_addr, mcast_port, log);
else
mcast_sock=getSocketFactory().createMulticastSocket("jgroups.mping.mcast_sock", mcast_port);
mcast_sock.setTimeToLive(ip_ttl);
if(receive_on_all_interfaces || (receive_interfaces != null && !receive_interfaces.isEmpty())) {
List<NetworkInterface> interfaces;
if(receive_interfaces != null)
interfaces=receive_interfaces;
else
interfaces=Util.getAllAvailableInterfaces();
bindToInterfaces(interfaces, mcast_sock, mcast_addr);
}
else {
if(bind_addr != null)
mcast_sock.setInterface(bind_addr);
mcast_sock.joinGroup(mcast_addr);
}
// Create mcast sender socket
if(send_on_all_interfaces || (send_interfaces != null && !send_interfaces.isEmpty())) {
List interfaces;
if(send_interfaces != null)
interfaces=send_interfaces;
else
interfaces=Util.getAllAvailableInterfaces();
mcast_send_sockets=new MulticastSocket[interfaces.size()];
int index=0;
for(Iterator it=interfaces.iterator(); it.hasNext();) {
NetworkInterface intf=(NetworkInterface)it.next();
mcast_send_sockets[index]=new MulticastSocket();
mcast_send_sockets[index].setNetworkInterface(intf);
mcast_send_sockets[index].setTimeToLive(ip_ttl);
index++;
}
}
startReceiver();
super.start();
}
public void stop() {
receiver=null;
Util.close(mcast_sock);
mcast_sock=null;
super.stop();
}
public void run() {
final byte[] receive_buf=new byte[65535];
DatagramPacket packet=new DatagramPacket(receive_buf, receive_buf.length);
while(mcast_sock != null && receiver != null && Thread.currentThread().equals(receiver)) {
packet.setData(receive_buf, 0, receive_buf.length);
try {
mcast_sock.receive(packet);
DataInput inp=new ByteArrayDataInputStream(packet.getData(), packet.getOffset(), packet.getLength());
Message msg=new Message();
msg.readFrom(inp);
if(!Objects.equals(local_addr,msg.getSrc())) // discard discovery request from self
up(msg);
}
catch(SocketException socketEx) {
break;
}
catch(Throwable ex) {
log.error(Util.getMessage("FailedReceivingPacketFrom"), packet.getSocketAddress(), ex);
}
}
log.debug("receiver thread terminated");
}
protected void bindToInterfaces(List<NetworkInterface> interfaces, MulticastSocket s, InetAddress mcast_addr) throws IOException {
SocketAddress tmp_mcast_addr=new InetSocketAddress(mcast_addr, mcast_port);
for(Iterator it=interfaces.iterator(); it.hasNext();) {
NetworkInterface i=(NetworkInterface)it.next();
for(Enumeration en2=i.getInetAddresses(); en2.hasMoreElements();) {
InetAddress addr=(InetAddress)en2.nextElement();
if ((Util.getIpStackType() == StackType.IPv4 && addr instanceof Inet4Address)
|| (Util.getIpStackType() == StackType.IPv6 && addr instanceof Inet6Address)) {
s.joinGroup(tmp_mcast_addr, i);
log.trace("joined " + tmp_mcast_addr + " on " + i.getName() + " (" + addr + ")");
break;
}
}
}
}
protected void startReceiver() {
if(receiver == null || !receiver.isAlive()) {
ThreadFactory factory=getThreadFactory();
receiver=factory != null? factory.newThread(this, "MPING") : new Thread(this, "MPING)");
receiver.setDaemon(true);
receiver.start();
log.debug("receiver thread started");
}
}
@Override
protected void sendMcastDiscoveryRequest(Message msg) {
try {
if(msg.getSrc() == null)
msg.setSrc(local_addr);
ByteArrayDataOutputStream out=new ByteArrayDataOutputStream((int)(msg.size()+1));
msg.writeTo(out);
Buffer buf=out.getBuffer();
DatagramPacket packet=new DatagramPacket(buf.getBuf(), buf.getOffset(), buf.getLength(), mcast_addr, mcast_port);
if(mcast_send_sockets != null) {
MulticastSocket s;
for(int i=0; i < mcast_send_sockets.length; i++) {
s=mcast_send_sockets[i];
try {
s.send(packet);
}
catch(Exception e) {
log.error(Util.getMessage("FailedSendingPacketOnSocket"), s);
}
}
}
else { // DEFAULT path
if(mcast_sock != null)
mcast_sock.send(packet);
}
}
catch(Exception ex) {
log.error(Util.getMessage("FailedSendingDiscoveryRequest"), ex);
}
}
}