/*

 * Copyright (c) 1994, 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/**

 * FTP stream opener.

 */

package sun.net.www.protocol.ftp;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.BufferedInputStream;

import java.io.FilterInputStream;

import java.io.FilterOutputStream;

import java.io.FileNotFoundException;

import java.net.MalformedURLException;

import java.net.URL;

import java.net.SocketPermission;

import java.net.UnknownHostException;

import java.net.InetSocketAddress;

import java.net.URI;

import java.net.Proxy;

import java.net.ProxySelector;

import java.util.List;

import java.util.StringTokenizer;

import java.util.Iterator;

import java.security.Permission;

import java.util.Properties;

import sun.net.NetworkClient;

import sun.net.util.IPAddressUtil;

import sun.net.www.MessageHeader;

import sun.net.www.MeteredStream;

import sun.net.www.URLConnection;

import sun.net.www.protocol.http.HttpURLConnection;

import sun.net.ftp.FtpClient;

import sun.net.ftp.FtpProtocolException;

import sun.net.ProgressSource;

import sun.net.ProgressMonitor;

import sun.net.www.ParseUtil;

import sun.security.action.GetPropertyAction;

/**

 * This class Opens an FTP input (or output) stream given a URL.

 * It works as a one shot FTP transfer :

 * <UL>

 * <LI>Login</LI>

 * <LI>Get (or Put) the file</LI>

 * <LI>Disconnect</LI>

 * </UL>

 * You should not have to use it directly in most cases because all will be handled

 * in a abstract layer. Here is an example of how to use the class:

 * <pre>{@code

 * URL url = new URL("ftp://ftp.sun.com/pub/test.txt");

 * UrlConnection con = url.openConnection();

 * InputStream is = con.getInputStream();

 * ...

 * is.close();

 * }</pre>

 *

 * @see sun.net.ftp.FtpClient

 */

public class FtpURLConnection extends URLConnection {

    // In case we have to use proxies, we use HttpURLConnection

    HttpURLConnection http = null;

    private Proxy instProxy;

    InputStream is = null;

    OutputStream os = null;

    FtpClient ftp = null;

    Permission permission;

    String password;

    String user;

    String host;

    String pathname;

    String filename;

    String fullpath;

    int port;

    static final int NONE = 0;

    static final int ASCII = 1;

    static final int BIN = 2;

    static final int DIR = 3;

    int type = NONE;

    /* Redefine timeouts from java.net.URLConnection as we need -1 to mean

     * not set. This is to ensure backward compatibility.

     */

    private int connectTimeout = NetworkClient.DEFAULT_CONNECT_TIMEOUT;;

    private int readTimeout = NetworkClient.DEFAULT_READ_TIMEOUT;;

    /**

     * For FTP URLs we need to have a special InputStream because we

     * need to close 2 sockets after we're done with it :

     *  - The Data socket (for the file).

     *   - The command socket (FtpClient).

     * Since that's the only class that needs to see that, it is an inner class.

     */

    protected class FtpInputStream extends FilterInputStream {

        FtpClient ftp;

        FtpInputStream(FtpClient cl, InputStream fd) {

            super(new BufferedInputStream(fd));

            ftp = cl;

        }

        @Override

        public void close() throws IOException {

            super.close();

            if (ftp != null) {

                ftp.close();

            }

        }

    }

    /**

     * For FTP URLs we need to have a special OutputStream because we

     * need to close 2 sockets after we're done with it :

     *  - The Data socket (for the file).

     *   - The command socket (FtpClient).

     * Since that's the only class that needs to see that, it is an inner class.

     */

    protected class FtpOutputStream extends FilterOutputStream {

        FtpClient ftp;

        FtpOutputStream(FtpClient cl, OutputStream fd) {

            super(fd);

            ftp = cl;

        }

        @Override

        public void close() throws IOException {

            super.close();

            if (ftp != null) {

                ftp.close();

            }

        }

    }

    static URL checkURL(URL u) throws IllegalArgumentException {

        if (u != null) {

            if (u.toExternalForm().indexOf('\n') > -1) {

                Exception mfue = new MalformedURLException("Illegal character in URL");

                throw new IllegalArgumentException(mfue.getMessage(), mfue);

            }

        }

        String s = IPAddressUtil.checkAuthority(u);

        if (s != null) {

            Exception mfue = new MalformedURLException(s);

            throw new IllegalArgumentException(mfue.getMessage(), mfue);

        }

        return u;

    }

    /**

     * Creates an FtpURLConnection from a URL.

     *

     * @param   url     The {@code URL} to retrieve or store.

     */

    public FtpURLConnection(URL url) {

        this(url, null);

    }

    /**

     * Same as FtpURLconnection(URL) with a per connection proxy specified

     */

    FtpURLConnection(URL url, Proxy p) {

        super(checkURL(url));

        instProxy = p;

        host = url.getHost();

        port = url.getPort();

        String userInfo = url.getUserInfo();

        if (userInfo != null) { // get the user and password

            int delimiter = userInfo.indexOf(':');

            if (delimiter == -1) {

                user = ParseUtil.decode(userInfo);

                password = null;

            } else {

                user = ParseUtil.decode(userInfo.substring(0, delimiter++));

                password = ParseUtil.decode(userInfo.substring(delimiter));

            }

        }

    }

    private void setTimeouts() {

        if (ftp != null) {

            if (connectTimeout >= 0) {

                ftp.setConnectTimeout(connectTimeout);

            }

            if (readTimeout >= 0) {

                ftp.setReadTimeout(readTimeout);

            }

        }

    }

    /**

     * Connects to the FTP server and logs in.

     *

     * @throws  FtpLoginException if the login is unsuccessful

     * @throws  FtpProtocolException if an error occurs

     * @throws  UnknownHostException if trying to connect to an unknown host

     */

    public synchronized void connect() throws IOException {

        if (connected) {

            return;

        }

        Proxy p = null;

        if (instProxy == null) { // no per connection proxy specified

            /**

             * Do we have to use a proxy?

             */

            ProxySelector sel = java.security.AccessController.doPrivileged(

                    new java.security.PrivilegedAction<ProxySelector>() {

                        public ProxySelector run() {

                            return ProxySelector.getDefault();

                        }

                    });

            if (sel != null) {

                URI uri = sun.net.www.ParseUtil.toURI(url);

                final List<Proxy> proxies;

                try {

                    proxies = sel.select(uri);

                } catch (IllegalArgumentException iae) {

                    throw new IOException("Failed to select a proxy", iae);

                }

                final Iterator<Proxy> it = proxies.iterator();

                while (it.hasNext()) {

                    p = it.next();

                    if (p == null || p == Proxy.NO_PROXY ||

                        p.type() == Proxy.Type.SOCKS) {

                        break;

                    }

                    if (p.type() != Proxy.Type.HTTP ||

                            !(p.address() instanceof InetSocketAddress)) {

                        sel.connectFailed(uri, p.address(), new IOException("Wrong proxy type"));

                        continue;

                    }

                    // OK, we have an http proxy

                    InetSocketAddress paddr = (InetSocketAddress) p.address();

                    try {

                        http = new HttpURLConnection(url, p);

                        http.setDoInput(getDoInput());

                        http.setDoOutput(getDoOutput());

                        if (connectTimeout >= 0) {

                            http.setConnectTimeout(connectTimeout);

                        }

                        if (readTimeout >= 0) {

                            http.setReadTimeout(readTimeout);

                        }

                        http.connect();

                        connected = true;

                        return;

                    } catch (IOException ioe) {

                        sel.connectFailed(uri, paddr, ioe);

                        http = null;

                    }

                }

            }

        } else { // per connection proxy specified

            p = instProxy;

            if (p.type() == Proxy.Type.HTTP) {

                http = new HttpURLConnection(url, instProxy);

                http.setDoInput(getDoInput());

                http.setDoOutput(getDoOutput());

                if (connectTimeout >= 0) {

                    http.setConnectTimeout(connectTimeout);

                }

                if (readTimeout >= 0) {

                    http.setReadTimeout(readTimeout);

                }

                http.connect();

                connected = true;

                return;

            }

        }

        if (user == null) {

            user = "anonymous";

            Properties props = GetPropertyAction.privilegedGetProperties();

            String vers = props.getProperty("java.version");

            password = props.getProperty("ftp.protocol.user",

                    "Java" + vers + "@");

        }

        try {

            ftp = FtpClient.create();

            if (p != null) {

                ftp.setProxy(p);

            }

            setTimeouts();

            if (port != -1) {

                ftp.connect(new InetSocketAddress(host, port));

            } else {

                ftp.connect(new InetSocketAddress(host, FtpClient.defaultPort()));

            }

        } catch (UnknownHostException e) {

            // Maybe do something smart here, like use a proxy like iftp.

            // Just keep throwing for now.

            throw e;

        } catch (FtpProtocolException fe) {

            if (ftp != null) {

                try {

                    ftp.close();

                } catch (IOException ioe) {

                    fe.addSuppressed(ioe);

                }

            }

            throw new IOException(fe);

        }

        try {

            ftp.login(user, password == null ? null : password.toCharArray());

        } catch (sun.net.ftp.FtpProtocolException e) {

            ftp.close();

            // Backward compatibility

            throw new sun.net.ftp.FtpLoginException("Invalid username/password");

        }

        connected = true;

    }

    /*

     * Decodes the path as per the RFC-1738 specifications.

     */

    private void decodePath(String path) {

        int i = path.indexOf(";type=");

        if (i >= 0) {

            String s1 = path.substring(i + 6, path.length());

            if ("i".equalsIgnoreCase(s1)) {

                type = BIN;

            }

            if ("a".equalsIgnoreCase(s1)) {

                type = ASCII;

            }

            if ("d".equalsIgnoreCase(s1)) {

                type = DIR;

            }

            path = path.substring(0, i);

        }

        if (path != null && path.length() > 1 &&

                path.charAt(0) == '/') {

            path = path.substring(1);

        }

        if (path == null || path.isEmpty()) {

            path = "./";

        }

        if (!path.endsWith("/")) {

            i = path.lastIndexOf('/');

            if (i > 0) {

                filename = path.substring(i + 1, path.length());

                filename = ParseUtil.decode(filename);

                pathname = path.substring(0, i);

            } else {

                filename = ParseUtil.decode(path);

                pathname = null;

            }

        } else {

            pathname = path.substring(0, path.length() - 1);

            filename = null;

        }

        if (pathname != null) {

            fullpath = pathname + "/" + (filename != null ? filename : "");

        } else {

            fullpath = filename;

        }

    }

    /*

     * As part of RFC-1738 it is specified that the path should be

     * interpreted as a series of FTP CWD commands.

     * This is because, '/' is not necessarly the directory delimiter

     * on every systems.

     */

    private void cd(String path) throws FtpProtocolException, IOException {

        if (path == null || path.isEmpty()) {

            return;

        }

        if (path.indexOf('/') == -1) {

            ftp.changeDirectory(ParseUtil.decode(path));

            return;

        }

        StringTokenizer token = new StringTokenizer(path, "/");

        while (token.hasMoreTokens()) {

            ftp.changeDirectory(ParseUtil.decode(token.nextToken()));

        }

    }

    /**

     * Get the InputStream to retreive the remote file. It will issue the

     * "get" (or "dir") command to the ftp server.

     *

     * @return  the {@code InputStream} to the connection.

     *

     * @throws  IOException if already opened for output

     * @throws  FtpProtocolException if errors occur during the transfert.

     */

    @Override

    public InputStream getInputStream() throws IOException {

        if (!connected) {

            connect();

        }

        if (http != null) {

            return http.getInputStream();

        }

        if (os != null) {

            throw new IOException("Already opened for output");

        }

        if (is != null) {

            return is;

        }

        MessageHeader msgh = new MessageHeader();

        boolean isAdir = false;

        try {

            decodePath(url.getPath());

            if (filename == null || type == DIR) {

                ftp.setAsciiType();

                cd(pathname);

                if (filename == null) {

                    is = new FtpInputStream(ftp, ftp.list(null));

                } else {

                    is = new FtpInputStream(ftp, ftp.nameList(filename));

                }

            } else {

                if (type == ASCII) {

                    ftp.setAsciiType();

                } else {

                    ftp.setBinaryType();

                }

                cd(pathname);

                is = new FtpInputStream(ftp, ftp.getFileStream(filename));

            }

            /* Try to get the size of the file in bytes.  If that is

            successful, then create a MeteredStream. */

            try {

                long l = ftp.getLastTransferSize();

                msgh.add("content-length", Long.toString(l));

                if (l > 0) {

                    // Wrap input stream with MeteredStream to ensure read() will always return -1

                    // at expected length.

                    // Check if URL should be metered

                    boolean meteredInput = ProgressMonitor.getDefault().shouldMeterInput(url, "GET");

                    ProgressSource pi = null;

                    if (meteredInput) {

                        pi = new ProgressSource(url, "GET", l);

                        pi.beginTracking();

                    }

                    is = new MeteredStream(is, pi, l);

                }

            } catch (Exception e) {

                e.printStackTrace();

            /* do nothing, since all we were doing was trying to

            get the size in bytes of the file */

            }

            if (isAdir) {

                msgh.add("content-type", "text/plain");

                msgh.add("access-type", "directory");

            } else {

                msgh.add("access-type", "file");

                String ftype = guessContentTypeFromName(fullpath);

                if (ftype == null && is.markSupported()) {

                    ftype = guessContentTypeFromStream(is);

                }

                if (ftype != null) {

                    msgh.add("content-type", ftype);

                }

            }

        } catch (FileNotFoundException e) {

            try {

                cd(fullpath);

                /* if that worked, then make a directory listing