content: /*
   * Copyright (c) 2002, 2022, Oracle and/or its affiliates.
   *
   * This program is free software; you can redistribute it and/or modify it under
   * the terms of the GNU General Public License, version 2.0, as published by the
   * Free Software Foundation.
   *
   * This program is also distributed with certain software (including but not
   * limited to OpenSSL) that is licensed under separate terms, as designated in a
   * particular file or component or in included license documentation. The
   * authors of MySQL hereby grant you an additional permission to link the
   * program and your derivative works with the separately licensed software that
   * they have included with MySQL.
   *
   * Without limiting anything contained in the foregoing, this file, which is
   * part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
   * version 1.0, a copy of which can be found at
   * http://oss.oracle.com/licenses/universal-foss-exception.
   *
   * 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, version 2.0,
   * 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.,
   * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
   */
  
  package com.mysql.cj.protocol;
  
  import java.io.Closeable;
  import java.io.IOException;
  import java.net.InetAddress;
  import java.net.InetSocketAddress;
  import java.net.Socket;
  import java.net.SocketException;
  
  import com.mysql.cj.Messages;
  import com.mysql.cj.conf.PropertyKey;
  import com.mysql.cj.conf.PropertySet;
  import com.mysql.cj.log.Log;
  
  /**
   * Socket factory for vanilla TCP/IP sockets (the standard)
   */
  public class StandardSocketFactory implements SocketFactory {
  
      /** The hostname to connect to */
      protected String host = null;
  
      /** The port number to connect to */
      protected int port = 3306;
  
      /** The underlying TCP/IP socket to use */
      protected Socket rawSocket = null;
  
      /** The wrapper for underlying TCP/IP socket */
      protected Socket sslSocket = null;
  
      /** The remaining login time in milliseconds. Initial value set from defined DriverManager.setLoginTimeout() */
      protected int loginTimeoutCountdown = 0;
  
      /** Time when last Login Timeout check occurred */
      protected long loginTimeoutCheckTimestamp = System.currentTimeMillis();
  
      /** Backup original Socket timeout to be restored after handshake */
      protected int socketTimeoutBackup = 0;
  
      /**
       * Create the raw socket.
       *
       * @param props
       *            properties available to affect behaviour during socket creation.
       * @return socket
       */
      protected Socket createSocket(PropertySet props) {
          return new Socket();
      }
  
      /**
       * Configures socket properties based on properties from the connection
       * (tcpNoDelay, snd/rcv buf, traffic class, etc).
       * 
       * @param sock
       *            socket
       * @param pset
       *            properties
       * @throws SocketException
       *             if an error occurs
       * @throws IOException
       *             if an error occurs
       */
      protected void configureSocket(Socket sock, PropertySet pset) throws SocketException, IOException {
          sock.setTcpNoDelay(pset.getBooleanProperty(PropertyKey.tcpNoDelay).getValue());
          sock.setKeepAlive(pset.getBooleanProperty(PropertyKey.tcpKeepAlive).getValue());
  
          int receiveBufferSize = pset.getIntegerProperty(PropertyKey.tcpRcvBuf).getValue();
          if (receiveBufferSize > 0) {
              sock.setReceiveBufferSize(receiveBufferSize);
          }
  
          int sendBufferSize = pset.getIntegerProperty(PropertyKey.tcpSndBuf).getValue();
          if (sendBufferSize > 0) {
              sock.setSendBufferSize(sendBufferSize);
          }
  
          int trafficClass = pset.getIntegerProperty(PropertyKey.tcpTrafficClass).getValue();
          if (trafficClass > 0) {
              sock.setTrafficClass(trafficClass);
          }
      }
  
      @SuppressWarnings("unchecked")
      public <T extends Closeable> T connect(String hostname, int portNumber, PropertySet pset, int loginTimeout) throws IOException {
  
          this.loginTimeoutCountdown = loginTimeout;
  
          if (pset != null) {
              this.host = hostname;
              this.port = portNumber;
  
              String localSocketHostname = pset.getStringProperty(PropertyKey.localSocketAddress).getValue();
              InetSocketAddress localSockAddr = localSocketHostname != null && localSocketHostname.length() > 0
                      ? new InetSocketAddress(InetAddress.getByName(localSocketHostname), 0)
                      : null;
              int connectTimeout = pset.getIntegerProperty(PropertyKey.connectTimeout).getValue();
  
              if (this.host != null) {
                  InetAddress[] possibleAddresses = InetAddress.getAllByName(this.host);
  
                  if (possibleAddresses.length == 0) {
                      throw new SocketException("No addresses for host");
                  }
  
                  // save last exception to propagate to caller if connection fails
                  SocketException lastException = null;
  
                  // Need to loop through all possible addresses. Name lookup may return multiple addresses including IPv4 and IPv6 addresses. Some versions of
                  // MySQL don't listen on the IPv6 address so we try all addresses.
                  for (int i = 0; i < possibleAddresses.length; i++) {
                      try {
                          this.rawSocket = createSocket(pset);
  
                          configureSocket(this.rawSocket, pset);
  
                          InetSocketAddress sockAddr = new InetSocketAddress(possibleAddresses[i], this.port);
                          // bind to the local port if not using the ephemeral port
                          if (localSockAddr != null) {
                              this.rawSocket.bind(localSockAddr);
                          }
  
                          this.rawSocket.connect(sockAddr, getRealTimeout(connectTimeout));
  
                          break;
                      } catch (SocketException ex) {
                          lastException = ex;
                          resetLoginTimeCountdown();
                          this.rawSocket = null;
                      }
                  }
  
                  if (this.rawSocket == null && lastException != null) {
                      throw lastException;
                  }
  
                  resetLoginTimeCountdown();
  
                  this.sslSocket = this.rawSocket;
                  return (T) this.rawSocket;
              }
          }
  
          throw new SocketException("Unable to create socket");
      }
  
      public void beforeHandshake() throws IOException {
          resetLoginTimeCountdown();
          this.socketTimeoutBackup = this.rawSocket.getSoTimeout();
          this.rawSocket.setSoTimeout(getRealTimeout(this.socketTimeoutBackup));
      }
  
      @Override
      public <T extends Closeable> T performTlsHandshake(SocketConnection socketConnection, ServerSession serverSession) throws IOException {
          return performTlsHandshake(socketConnection, serverSession, null);
      }
  
      @SuppressWarnings("unchecked")
      @Override
      public <T extends Closeable> T performTlsHandshake(SocketConnection socketConnection, ServerSession serverSession, Log log) throws IOException {
          this.sslSocket = ExportControlled.performTlsHandshake(this.rawSocket, socketConnection, serverSession == null ? null : serverSession.getServerVersion(),
                  log);
          return (T) this.sslSocket;
      }
  
      public void afterHandshake() throws IOException {
          resetLoginTimeCountdown();
          this.rawSocket.setSoTimeout(this.socketTimeoutBackup);
      }
  
      /**
       * Decrements elapsed time since last reset from login timeout count down.
       * 
       * @throws SocketException
       *             If the login timeout is reached or exceeded.
       */
      protected void resetLoginTimeCountdown() throws SocketException {
          if (this.loginTimeoutCountdown > 0) {
              long now = System.currentTimeMillis();
              this.loginTimeoutCountdown -= now - this.loginTimeoutCheckTimestamp;
              if (this.loginTimeoutCountdown <= 0) {
                  throw new SocketException(Messages.getString("Connection.LoginTimeout"));
              }
              this.loginTimeoutCheckTimestamp = now;
          }
      }
  
      /**
       * Validates the connection/socket timeout that must really be used.
       * 
       * @param expectedTimeout
       *            The timeout to validate.
       * @return The timeout to be used.
       */
      protected int getRealTimeout(int expectedTimeout) {
          if (this.loginTimeoutCountdown > 0 && (expectedTimeout == 0 || expectedTimeout > this.loginTimeoutCountdown)) {
              return this.loginTimeoutCountdown;
          }
          return expectedTimeout;
      }
  }
  