/**
 * Returns a list of {@link NetworkData}.
 * 
 * This method iterates over all the network interfaces to return those that
 * are up and running.
 * 
 * NOTE: it may be VERY EXPENSIVE on Windows systems, because that OS
 * creates a lot of virtual network interfaces.
 * 
 * @return a list of {@link NetworkData}
 */
public static List<NetworkData> getNetworkDataList() {
	try {
		InetAddress inetAddress = InetAddress.getLocalHost();
		List<NetworkInterface> networkInterfaces = Collections.list(NetworkInterface.getNetworkInterfaces());

		HashSet<NetworkData> networkDataHashSet = new HashSet<>();
		for (NetworkInterface networkInterface : networkInterfaces) {
			NetworkData networkData = buildNetworkData(networkInterface, inetAddress);
			if (networkData != null) {
				networkDataHashSet.add(networkData);
			}
		}
		return new ArrayList<>(networkDataHashSet);
	} catch (SocketException | NullPointerException | UnknownHostException e) {
		return Collections.emptyList();
	}
}
 

/**
 * The following method, createSocket, is defined in NetworkClient
 * and overridden here so that the socket facroty is used to create
 * new sockets.
 */
@Override
protected Socket createSocket() throws IOException {
    try {
        return sslSocketFactory.createSocket();
    } catch (SocketException se) {
        //
        // bug 6771432
        // javax.net.SocketFactory throws a SocketException with an
        // UnsupportedOperationException as its cause to indicate that
        // unconnected sockets have not been implemented.
        //
        Throwable t = se.getCause();
        if (t != null && t instanceof UnsupportedOperationException) {
            return super.createSocket();
        } else {
            throw se;
        }
    }
}
 

private boolean populateNonce() {
  try {
    transaction.updateNonce();
    return true;
  } catch (final RuntimeException e) {
    LOG.warn("Unable to get nonce from web3j provider.", e);
    final Throwable cause = e.getCause();
    if (cause instanceof SocketException
        || cause instanceof SocketTimeoutException
        || cause instanceof TimeoutException) {
      routingContext.fail(
          GATEWAY_TIMEOUT.code(), new JsonRpcException(CONNECTION_TO_DOWNSTREAM_NODE_TIMED_OUT));
    } else if (cause instanceof SSLHandshakeException) {
      routingContext.fail(BAD_GATEWAY.code(), cause);
    } else {
      routingContext.fail(GATEWAY_TIMEOUT.code(), new JsonRpcException(INTERNAL_ERROR));
    }
  } catch (final Throwable thrown) {
    LOG.debug("Failed to encode/serialize transaction: {}", transaction, thrown);
    routingContext.fail(BAD_REQUEST.code(), new JsonRpcException(INTERNAL_ERROR));
  }
  return false;
}
 

public void setProperties(Socket socket) throws SocketException{
    if (rxBufSize != null)
        socket.setReceiveBufferSize(rxBufSize.intValue());
    if (txBufSize != null)
        socket.setSendBufferSize(txBufSize.intValue());
    if (ooBInline !=null)
        socket.setOOBInline(ooBInline.booleanValue());
    if (soKeepAlive != null)
        socket.setKeepAlive(soKeepAlive.booleanValue());
    if (performanceConnectionTime != null && performanceLatency != null &&
            performanceBandwidth != null)
        socket.setPerformancePreferences(
                performanceConnectionTime.intValue(),
                performanceLatency.intValue(),
                performanceBandwidth.intValue());
    if (soReuseAddress != null)
        socket.setReuseAddress(soReuseAddress.booleanValue());
    if (soLingerOn != null && soLingerTime != null)
        socket.setSoLinger(soLingerOn.booleanValue(),
                soLingerTime.intValue());
    if (soTimeout != null && soTimeout.intValue() >= 0)
        socket.setSoTimeout(soTimeout.intValue());
    if (tcpNoDelay != null)
        socket.setTcpNoDelay(tcpNoDelay.booleanValue());
}
 

@Override
public void receive(DatagramPacket p) throws IOException {
    // get temporary direct buffer with a capacity of p.bufLength
    int bufLength = DatagramPackets.getBufLength(p);
    ByteBuffer bb = Util.getTemporaryDirectBuffer(bufLength);
    try {
        long nanos = MILLISECONDS.toNanos(timeout);
        SocketAddress sender = dc.blockingReceive(bb, nanos);
        bb.flip();
        synchronized (p) {
            // copy bytes to the DatagramPacket and set length
            int len = Math.min(bb.limit(), DatagramPackets.getBufLength(p));
            bb.get(p.getData(), p.getOffset(), len);
            DatagramPackets.setLength(p, len);

            // sender address
            p.setSocketAddress(sender);
        }
    } catch (ClosedChannelException e) {
        var exc = new SocketException("Socket closed");
        exc.initCause(e);
        throw exc;
    } finally {
        Util.offerFirstTemporaryDirectBuffer(bb);
    }
}
 

/**
 * The following method, createSocket, is defined in NetworkClient
 * and overridden here so that the socket facroty is used to create
 * new sockets.
 */
@Override
protected Socket createSocket() throws IOException {
    try {
        return sslSocketFactory.createSocket();
    } catch (SocketException se) {
        //
        // bug 6771432
        // javax.net.SocketFactory throws a SocketException with an
        // UnsupportedOperationException as its cause to indicate that
        // unconnected sockets have not been implemented.
        //
        Throwable t = se.getCause();
        if (t != null && t instanceof UnsupportedOperationException) {
            return super.createSocket();
        } else {
            throw se;
        }
    }
}
 

/**
 * Returns a list of all the addresses on the system.
 * @param  inclLoopback
 *         if {@code true}, include the loopback addresses
 * @param  ipv4Only
 *         it {@code true}, only IPv4 addresses will be included
 */
static List<InetAddress> getAddresses(boolean inclLoopback,
                                      boolean ipv4Only)
    throws SocketException {
    ArrayList<InetAddress> list = new ArrayList<InetAddress>();
    Enumeration<NetworkInterface> nets =
             NetworkInterface.getNetworkInterfaces();
    for (NetworkInterface netInf : Collections.list(nets)) {
        Enumeration<InetAddress> addrs = netInf.getInetAddresses();
        for (InetAddress addr : Collections.list(addrs)) {
            if (!list.contains(addr) &&
                    (inclLoopback ? true : !addr.isLoopbackAddress()) &&
                    (ipv4Only ? (addr instanceof Inet4Address) : true)) {
                list.add(addr);
            }
        }
    }

    return list;
}
 

public String getLocalIpAddresses() {
    ArrayList<String> addresses = new ArrayList<String>();
    try {
        for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en
                .hasMoreElements();) {
            NetworkInterface intf = en.nextElement();
            for (Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); enumIpAddr
                    .hasMoreElements();) {
                InetAddress inetAddress = enumIpAddr.nextElement();
                if (!inetAddress.isLoopbackAddress()) {
                    addresses.add(inetAddress.getHostAddress().toString());
                }
            }
        }
    } catch (SocketException ex) {
        Log.e(THIS_FILE, "Impossible to get ip address", ex);
    }
    return TextUtils.join("\n", addresses);
}
 

public static String getPhoneIp(Context application) {
    WifiManager wifiManager = (WifiManager) application.getSystemService("wifi");
    if (wifiManager.isWifiEnabled()) {
        return intToIp(wifiManager.getConnectionInfo().getIpAddress());
    }
    try {
        Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces();
        while (en.hasMoreElements()) {
            Enumeration<InetAddress> enumIpAddr = ((NetworkInterface) en.nextElement()).getInetAddresses();
            while (enumIpAddr.hasMoreElements()) {
                InetAddress inetAddress = (InetAddress) enumIpAddr.nextElement();
                if (!inetAddress.isLoopbackAddress()) {
                    return inetAddress.getHostAddress().toString();
                }
            }
        }
    } catch (SocketException e) {
        e.printStackTrace();
    }
    return null;
}
 

/**
 * On systems with multiple network interfaces and mixed IPv6/IPv4 get a valid network
 * interface for binding to multicast
 *
 * @return a network interface suitable for multicast
 * @throws SocketException if a problem occurs while reading the network interfaces
 */
public static NetworkInterface getMulticastNetworkInterface() throws SocketException
{
    Enumeration<NetworkInterface> networkInterfaces = NetworkInterface.getNetworkInterfaces();
    while (networkInterfaces.hasMoreElements())
    {
        NetworkInterface networkInterface = networkInterfaces.nextElement();
        Enumeration<InetAddress> addressesFromNetworkInterface = networkInterface.getInetAddresses();
        while (addressesFromNetworkInterface.hasMoreElements())
        {
            InetAddress inetAddress = addressesFromNetworkInterface.nextElement();
            if (inetAddress.isSiteLocalAddress()
                    && !inetAddress.isAnyLocalAddress()
                    && !inetAddress.isLinkLocalAddress()
                    && !inetAddress.isLoopbackAddress()
                    && !inetAddress.isMulticastAddress())
            {
                return networkInterface;
            }
        }
    }

    return null;
}
 

/**
 * Layer SSL traffic over an existing connection, rather than
 * creating a new connection.
 *
 * The existing connection may be used only for SSL traffic (using this
 * SSLSocket) until the SSLSocket.close() call returns. However, if a
 * protocol error is detected, that existing connection is automatically
 * closed.
 * <p>
 * This particular constructor always uses the socket in the
 * role of an SSL client. It may be useful in cases which start
 * using SSL after some initial data transfers, for example in some
 * SSL tunneling applications or as part of some kinds of application
 * protocols which negotiate use of a SSL based security.
 */
SSLSocketImpl(SSLContextImpl sslContext, Socket sock,
        String peerHost, int port, boolean autoClose) throws IOException {
    super(sock);
    // We always layer over a connected socket
    if (!sock.isConnected()) {
        throw new SocketException("Underlying socket is not connected");
    }

    this.sslContext = sslContext;
    HandshakeHash handshakeHash = new HandshakeHash();
    this.conContext = new TransportContext(sslContext, this,
            new SSLSocketInputRecord(handshakeHash),
            new SSLSocketOutputRecord(handshakeHash), true);
    this.peerHost = peerHost;
    this.autoClose = autoClose;
    doneConnect();
}
 

/**
 * Load folder in a separate thread.
 *
 * @param folder       current folder
 * @param outputStream client connection
 * @throws InterruptedException on error
 * @throws IOException          on error
 */
public static void loadFolder(ExchangeSession.Folder folder, OutputStream outputStream) throws InterruptedException, IOException {
    FolderLoadThread folderLoadThread = new FolderLoadThread(currentThread().getName(), folder);
    folderLoadThread.start();
    while (!folderLoadThread.isComplete) {
        folderLoadThread.join(20000);
        LOGGER.debug("Still loading " + folder.folderPath + " (" + folder.count() + " messages)");
        if (Settings.getBooleanProperty("davmail.enableKeepAlive", false)) {
            try {
                outputStream.write(' ');
                outputStream.flush();
            } catch (SocketException e) {
                folderLoadThread.interrupt();
                throw e;
            }
        }
    }
    if (folderLoadThread.exception != null) {
        throw folderLoadThread.exception;
    }

}
 

public static String getMask(String intf){
    try {
        NetworkInterface ntwrk = NetworkInterface.getByName(intf);
        Iterator<InterfaceAddress> addrList = ntwrk.getInterfaceAddresses().iterator();
        while (addrList.hasNext()) {
            InterfaceAddress addr = addrList.next();
            InetAddress ip = addr.getAddress();
            if (ip instanceof Inet4Address) {
                String mask = ip.getHostAddress() + "/" +
                        addr.getNetworkPrefixLength();
                return mask;
            }
        }
    } catch (SocketException e) {
        e.printStackTrace();
    }
    return null;
}
 

@Test
public void testOutputStreamClosed() throws Exception {
	LogMessageAccumulator logMessages = new LogMessageAccumulator();
	try {
		logMessages.registerTo(RemoteEndpoint.class);
		
		TestEndpoint endp = new TestEndpoint();
		MessageConsumer consumer = new MessageConsumer() {
			@Override
			public void consume(Message message) throws JsonRpcException {
				throw new JsonRpcException(new SocketException("Socket closed"));
			}
		};
		RemoteEndpoint endpoint = new RemoteEndpoint(consumer, endp);
		endpoint.notify("foo", null);
		
		logMessages.await(Level.INFO, "Failed to send notification message.");
	} finally {
		logMessages.unregister();
	}
}
 

/**
 * 获取可用的端口号
 */
public void getMyUsefulPort()
{
	while(true)
	{
   		try
   		{
   			// 实例化一个DatagramSocket
   			socket = new DatagramSocket(myPort);
   			break;
   		}
   		catch (SocketException e)
   		{
   			myPort++;
   		}
	}
}
 

private static String getLinuxLocalIP() {
	String ip = "";
	try {
		Enumeration<NetworkInterface> e1 = (Enumeration<NetworkInterface>) NetworkInterface.getNetworkInterfaces();
		while (e1.hasMoreElements()) {
			NetworkInterface ni = e1.nextElement();
			if (netWorkCard.equals(ni.getName()) || NETWORK_CARD.equals(ni.getName())
					|| NETWORK_CARD_BAND.equals(ni.getName())) {
				Enumeration<InetAddress> e2 = ni.getInetAddresses();
				while (e2.hasMoreElements()) {
					InetAddress ia = e2.nextElement();
					if (ia instanceof Inet6Address) {
						continue;
					}
					ip = ia.getHostAddress();
				}
				break;
			} else {
				continue;
			}
		}
	} catch (SocketException e) {
		e.printStackTrace();
	}
	return ip;
}
 

/**
 * Send a DESCRIBE Message.
 * 
 * Call describe(MAX_RETRY = 5)
 * 
 * @return
 * @throws SocketException
 */
public String describe() throws SocketException
{
	String desc = null;
	
	try {
		desc = describe(3);
	} catch (RuntimeException rex) {
		
		if( desc == null ){
			//single retry
			desc = describe(3);
		}
		
	}
	
	return desc;
}
 

/**
 * Returns host address that can be targeted from the outside, like from a
 * test hub.
 *
 * @return host address
 * @throws RuntimeException
 *             if host name could not be determined or
 *             {@link SocketException} was caught during the determination.
 */
protected String getCurrentHostAddress() {
    try {
        Enumeration<NetworkInterface> interfaces = NetworkInterface
                .getNetworkInterfaces();
        while (interfaces.hasMoreElements()) {
            NetworkInterface nwInterface = interfaces.nextElement();
            if (!nwInterface.isUp() || nwInterface.isLoopback()
                    || nwInterface.isVirtual()) {
                continue;
            }
            Optional<String> address = getHostAddress(nwInterface);
            if (address.isPresent()) {
                return address.get();
            }
        }
    } catch (SocketException e) {
        throw new RuntimeException("Could not find the host name", e);
    }
    throw new RuntimeException(
            "No compatible (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) ip address found.");
}
 

/**
 * get ipv4 address of first matching network interface in the given list
 * network interface can not be loop back and it has to be up
 * @param interfaceNames
 * @return
 */
public static String getLocalIPFromNetworkInterfaces(List<String> interfaceNames) {

  try {
    for (String nwInterfaceName: interfaceNames) {
      NetworkInterface networkInterface = NetworkInterface.getByName(nwInterfaceName);
      if (networkInterface != null
          && !networkInterface.isLoopback()
          && networkInterface.isUp()) {
        List<InterfaceAddress> addressList = networkInterface.getInterfaceAddresses();
        for (InterfaceAddress adress: addressList) {
          if (isValidIPv4(adress.getAddress().getHostAddress())) {
            return adress.getAddress().getHostAddress();
          }
        }
      }
    }

  } catch (SocketException e) {
    LOG.log(Level.SEVERE, "Error retrieving network interface list", e);
  }

  return null;
}
 

@Override
public Set<SocketAddress> getRemoteAddresses()
        throws IOException {
    synchronized (stateLock) {
        if (!isOpen())
            throw new ClosedChannelException();
        if (!isConnected() || isShutdown)
            return Collections.emptySet();

        try {
            return SctpNet.getRemoteAddresses(fdVal, 0/*unused*/);
        } catch (SocketException unused) {
            /* an open connected channel should always have remote addresses */
            return remoteAddresses;
        }
    }
}
 

/**
 * Get local Ip address.
 */
public static InetAddress getLocalIPAddress() {
    Enumeration<NetworkInterface> enumeration = null;
    try {
        enumeration = NetworkInterface.getNetworkInterfaces();
    } catch (SocketException e) {
        e.printStackTrace();
    }
    if (enumeration != null) {
        while (enumeration.hasMoreElements()) {
            NetworkInterface nif = enumeration.nextElement();
            Enumeration<InetAddress> inetAddresses = nif.getInetAddresses();
            if (inetAddresses != null) {
                while (inetAddresses.hasMoreElements()) {
                    InetAddress inetAddress = inetAddresses.nextElement();
                    if (!inetAddress.isLoopbackAddress() && isIPv4Address(inetAddress.getHostAddress())) {
                        return inetAddress;
                    }
                }
            }
        }
    }
    return null;
}
 

public static void beforeUdpCreate() throws SocketException {
    if (System.getSecurityManager() != null) {
        if (numSockets.incrementAndGet() > maxSockets) {
            numSockets.decrementAndGet();
            throw new SocketException("maximum number of DatagramSockets reached");
        }
    }
}
 

protected void write(ByteBuffer buffer) throws IOException {

        while (buffer.hasRemaining()) {
            int written = channel().write(buffer);

            if (written < 0 || !isConnected()) {
                // indicator the socket was closed
                Closer.close(channel());
                throw new SocketException("Cannot write buffer to channel");
            }
        }
    }
 

/**
 * Manages refreshing the forests and hosts and retrying events after a host
 * becomes unavailable.
 * @param moveMgr the DataMovementManager (used to call readForestConfig to reset after black-listing an unavailable host)
 */
public HostAvailabilityListener(DataMovementManager moveMgr) {
  if (moveMgr == null) throw new IllegalArgumentException("moveMgr must not be null");
  this.moveMgr = moveMgr;
  if (moveMgr.getConnectionType() == DatabaseClient.ConnectionType.DIRECT) {
    hostUnavailableExceptions.add(SocketException.class);
    hostUnavailableExceptions.add(SSLException.class);
    hostUnavailableExceptions.add(UnknownHostException.class);
  }
}
 

/**
 * @see com.mysql.jdbc.SocketFactory#connect(String, Properties)
 */
public Socket connect(String host, int portNumber /* ignored */, Properties props) throws SocketException, IOException {
    String namedPipePath = props.getProperty(NAMED_PIPE_PROP_NAME);

    if (namedPipePath == null) {
        namedPipePath = "\\\\.\\pipe\\MySQL";
    } else if (namedPipePath.length() == 0) {
        throw new SocketException(Messages.getString("NamedPipeSocketFactory.2") + NAMED_PIPE_PROP_NAME + Messages.getString("NamedPipeSocketFactory.3"));
    }

    this.namedPipeSocket = new NamedPipeSocket(namedPipePath);

    return this.namedPipeSocket;
}
 

@Override
protected TSocket acceptImpl() throws TTransportException {
  TSocket ts = super.acceptImpl();
  try {
    ts.getSocket().setKeepAlive(true);
  } catch (SocketException e) {
    throw new TTransportException(e);
  }
  return ts;
}
 

private void setTimeout(int milliseconds) throws SQLException {
  // input and output protocol are identical in our usage
  TTransport socket = this.clientService.getInputProtocol().getTransport();
  if (socket instanceof SocketTimeout) {
    try {
      ((SocketTimeout)socket).setSoTimeout(milliseconds);
    } catch (SocketException se) {
      throw ThriftExceptionUtil.newSQLException(SQLState.SOCKET_EXCEPTION,
          se, se.getMessage());
    }
  }
}
 

/**
 * Open informSocket if it's not already done.
 */
synchronized void openInformSocketIfNeeded() throws SocketException {
    if (informSession == null) {
        informSession = new SnmpSession(this) ;
        if (SNMP_ADAPTOR_LOGGER.isLoggable(Level.FINER)) {
            SNMP_ADAPTOR_LOGGER.logp(Level.FINER, dbgTag,
               "openInformSocketIfNeeded",
                  "to send inform requests and receive inform responses");
        }
    }
}
 

/**
 * Accepts incoming connections and handles then with
 * <tt>TCPConnectionHandler</tt> instances.
 */
@Override
public void run() {
    try {
        /*
         * A server socket is opened with a connectivity queue of a size specified
         * in int floodProtection. Concurrent login handling under normal circumstances
         * should be allright, denial of service attacks via massive parallel
         * program logins can probably be prevented.
         */
        m_ServerSocket = new ServerSocket(m_Port, m_FloodProtection, m_Address);
        logger.debug("Listenening to {} (Port {})", m_ServerSocket.toString(), m_Port);

        // Infinite loop, taking care of resources in case of a lot of parallel logins
        do {
            Socket incoming = m_ServerSocket.accept();
            logger.debug("Making new connection {}", incoming.toString());
            if (m_Listening) {
                // FIXME: Replace with object pool due to resource issues
                m_ThreadPool.execute(new TCPConnectionHandler(m_ConnectionFactory.create(incoming)));
                count();
            } else {
                // just close the socket
                incoming.close();
            }
        } while (m_Listening);
    } catch (SocketException iex) {
        if (!m_Listening) {
            return;
        } else {
            iex.printStackTrace();
        }
    } catch (IOException e) {
        // FIXME: this is a major failure, how do we handle this
    }
}
 

@Override
public boolean isOobInline() {
	try {
		return getSocket().getOOBInline();
	} catch (SocketException e) {
		throw new RuntimeException(e);
	}
}