/jdk/src/share/classes/sun/net/spi/DefaultProxySelector.java

/*
 * Copyright (c) 2003, 2004, 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
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package sun.net.spi;

import sun.net.www.http.*;
import sun.net.NetProperties;
import java.net.*;
import java.util.*;
import java.util.regex.*;
import java.io.*;
import sun.misc.RegexpPool;
import java.security.AccessController;
import java.security.PrivilegedAction;

/**
 * Supports proxy settings using system properties This proxy selector
 * provides backward compatibility with the old http protocol handler
 * as far as how proxy is set
 *
 * Most of the implementation copied from the old http protocol handler
 *
 * Supports http/https/ftp.proxyHost, http/https/ftp.proxyPort,
 * proxyHost, proxyPort, and http/https/ftp.nonProxyHost, and socks.
 * NOTE: need to do gopher as well
 */
public class DefaultProxySelector extends ProxySelector {

    /**
     * This is where we define all the valid System Properties we have to
     * support for each given protocol.
     * The format of this 2 dimensional array is :
     * - 1 row per protocol (http, ftp, ...)
     * - 1st element of each row is the protocol name
     * - subsequent elements are prefixes for Host & Port properties
     *   listed in order of priority.
     * Example:
     * {"ftp", "ftp.proxy", "ftpProxy", "proxy", "socksProxy"},
     * means for FTP we try in that oder:
     *          + ftp.proxyHost & ftp.proxyPort
     *          + ftpProxyHost & ftpProxyPort
     *          + proxyHost & proxyPort
     *          + socksProxyHost & socksProxyPort
     *
     * Note that the socksProxy should *always* be the last on the list
     */
    final static String[][] props = {
        /*
         * protocol, Property prefix 1, Property prefix 2, ...
         */
        {"http", "http.proxy", "proxy", "socksProxy"},
        {"https", "https.proxy", "proxy", "socksProxy"},
        {"ftp", "ftp.proxy", "ftpProxy", "proxy", "socksProxy"},
        {"gopher", "gopherProxy", "socksProxy"},
        {"socket", "socksProxy"}
    };

    private static boolean hasSystemProxies = false;
    private static Properties defprops = new Properties();

    static {
        final String key = "java.net.useSystemProxies";
        Boolean b = (Boolean) AccessController.doPrivileged(
            new PrivilegedAction() {
                public Object run() {
                    return NetProperties.getBoolean(key);
                }});
        if (b != null && b.booleanValue()) {
            java.security.AccessController.doPrivileged(
                      new sun.security.action.LoadLibraryAction("net"));
            hasSystemProxies = init();
        }
    }

    /**
     * How to deal with "non proxy hosts":
     * since we do have to generate a RegexpPool we don't want to do that if
     * it's not necessary. Therefore we do cache the result, on a per-protocol
     * basis, and change it only when the "source", i.e. the system property,
     * did change.
     */

    static class NonProxyInfo {
        String hostsSource;
        RegexpPool hostsPool;
        String property;

        NonProxyInfo(String p, String s, RegexpPool pool) {
            property = p;
            hostsSource = s;
            hostsPool = pool;
        }
    }

    private static NonProxyInfo ftpNonProxyInfo = new NonProxyInfo("ftp.nonProxyHosts", null, null);
    private static NonProxyInfo httpNonProxyInfo = new NonProxyInfo("http.nonProxyHosts", null, null);

    /**
     * select() method. Where all the hard work is done.
     * Build a list of proxies depending on URI.
     * Since we're only providing compatibility with the system properties
     * from previous releases (see list above), that list will always
     * contain 1 single proxy, default being NO_PROXY.
     */
    public java.util.List<Proxy> select(URI uri) {
        if (uri == null) {
            throw new IllegalArgumentException("URI can't be null.");
        }
        String protocol = uri.getScheme();
        String host = uri.getHost();
        int port = uri.getPort();

        if (host == null) {
            // This is a hack to ensure backward compatibility in two
            // cases: 1. hostnames contain non-ascii characters,
            // internationalized domain names. in which case, URI will
            // return null, see BugID 4957669; 2. Some hostnames can
            // contain '_' chars even though it's not supposed to be
            // legal, in which case URI will return null for getHost,
            // but not for getAuthority() See BugID 4913253
            String auth = uri.getAuthority();
            if (auth != null) {
                int i;
                i = auth.indexOf('@');
                if (i >= 0) {
                    auth = auth.substring(i+1);
                }
                i = auth.lastIndexOf(':');
                if (i >= 0) {
                    try {
                        port = Integer.parseInt(auth.substring(i+1));
                    } catch (NumberFormatException e) {
                        port = -1;
                    }
                    auth = auth.substring(0,i);
                }
                host = auth;
            }
        }

        if (protocol == null || host == null) {
            throw new IllegalArgumentException("protocol = "+protocol+" host = "+host);
        }
        List<Proxy> proxyl = new ArrayList<Proxy>(1);

        // special case localhost and loopback addresses to
        // not go through proxy
        if (isLoopback(host)) {
            proxyl.add(Proxy.NO_PROXY);
            return proxyl;
        }

        NonProxyInfo pinfo = null;

        if ("http".equalsIgnoreCase(protocol)) {
            pinfo = httpNonProxyInfo;
        } else if ("https".equalsIgnoreCase(protocol)) {
            // HTTPS uses the same property as HTTP, for backward
            // compatibility
            pinfo = httpNonProxyInfo;
        } else if ("ftp".equalsIgnoreCase(protocol)) {
            pinfo = ftpNonProxyInfo;
        }

        /**
         * Let's check the System properties for that protocol
         */
        final String proto = protocol;
        final NonProxyInfo nprop = pinfo;
        final String urlhost = host.toLowerCase();

        /**
         * This is one big doPrivileged call, but we're trying to optimize
         * the code as much as possible. Since we're checking quite a few
         * System properties it does help having only 1 call to doPrivileged.
         * Be mindful what you do in here though!
         */
        Proxy p = (Proxy) AccessController.doPrivileged(
            new PrivilegedAction() {
                public Object run() {
                    int i, j;
                    String phost =  null;
                    int pport = 0;
                    String nphosts =  null;
                    InetSocketAddress saddr = null;

                    // Then let's walk the list of protocols in our array
                    for (i=0; i<props.length; i++) {
                        if (props[i][0].equalsIgnoreCase(proto)) {
                            for (j = 1; j < props[i].length; j++) {
                                /* System.getProp() will give us an empty
                                 * String, "" for a defined but "empty"
                                 * property.
                                 */
                                phost =  NetProperties.get(props[i][j]+"Host");
                                if (phost != null && phost.length() != 0)
                                    break;
                            }
                            if (phost == null || phost.length() == 0) {
                                /**
                                 * No system property defined for that
                                 * protocol. Let's check System Proxy
                                 * settings (Gnome & Windows) if we were
                                 * instructed to.
                                 */
                                if (hasSystemProxies) {
                                    String sproto;
                                    if (proto.equalsIgnoreCase("socket"))
                                        sproto = "socks";
                                    else
                                        sproto = proto;
                                    Proxy sproxy = getSystemProxy(sproto, urlhost);
                                    if (sproxy != null) {
                                        return sproxy;
                                    }
                                }
                                return Proxy.NO_PROXY;
                            }
                            // If a Proxy Host is defined for that protocol
                            // Let's get the NonProxyHosts property
                            if (nprop != null) {
                                nphosts = NetProperties.get(nprop.property);
                                synchronized (nprop) {
                                    if (nphosts == null) {
                                        nprop.hostsSource = null;
                                        nprop.hostsPool = null;
                                    } else {
                                        if (!nphosts.equals(nprop.hostsSource)) {
                                            RegexpPool pool = new RegexpPool();
                                            StringTokenizer st = new StringTokenizer(nphosts, "|", false);
                                            try {
                                                while (st.hasMoreTokens()) {
                                                    pool.add(st.nextToken().toLowerCase(), Boolean.TRUE);
                                                }
                                            } catch (sun.misc.REException ex) {
                                            }
                                            nprop.hostsPool = pool;
                                            nprop.hostsSource = nphosts;
                                        }
                                    }
                                    if (nprop.hostsPool != null &&
                                        nprop.hostsPool.match(urlhost) != null) {
                                        return Proxy.NO_PROXY;
                                    }
                                }
                            }
                            // We got a host, let's check for port

                            pport = NetProperties.getInteger(props[i][j]+"Port", 0).intValue();
                            if (pport == 0 && j < (props[i].length - 1)) {
                                // Can't find a port with same prefix as Host
                                // AND it's not a SOCKS proxy
                                // Let's try the other prefixes for that proto
                                for (int k = 1; k < (props[i].length - 1); k++) {
                                    if ((k != j) && (pport == 0))
                                        pport = NetProperties.getInteger(props[i][k]+"Port", 0).intValue();
                                }
                            }

                            // Still couldn't find a port, let's use default
                            if (pport == 0) {
                                if (j == (props[i].length - 1)) // SOCKS
                                    pport = defaultPort("socket");
                                else
                                    pport = defaultPort(proto);
                            }
                            // We did find a proxy definition.
                            // Let's create the address, but don't resolve it
                            // as this will be done at connection time
                            saddr = InetSocketAddress.createUnresolved(phost, pport);
                            // Socks is *always* the last on the list.
                            if (j == (props[i].length - 1)) {
                                return new Proxy(Proxy.Type.SOCKS, saddr);
                            } else {
                                return new Proxy(Proxy.Type.HTTP, saddr);
                            }
                        }
                    }
                    return Proxy.NO_PROXY;
                }});

        proxyl.add(p);

        /*
         * If no specific property was set for that URI, we should be
         * returning an iterator to an empty List.
         */
        return proxyl;
    }

    public void connectFailed(URI uri, SocketAddress sa, IOException ioe) {
        if (uri == null || sa == null || ioe == null) {
            throw new IllegalArgumentException("Arguments can't be null.");
        }
        // ignored
    }


    private int defaultPort(String protocol) {
        if ("http".equalsIgnoreCase(protocol)) {
            return 80;
        } else if ("https".equalsIgnoreCase(protocol)) {
            return 443;
        } else if ("ftp".equalsIgnoreCase(protocol)) {
            return 80;
        } else if ("socket".equalsIgnoreCase(protocol)) {
            return 1080;
        } else if ("gopher".equalsIgnoreCase(protocol)) {
            return 80;
        } else {
            return -1;
        }
    }

    private static final Pattern p6 = Pattern.compile("::1|(0:){7}1|(0:){1,6}:1");
    private boolean isLoopback(String host) {
        if (host == null || host.length() == 0)
            return false;

        if (host.equalsIgnoreCase("localhost"))
            return true;

        /* The string could represent a numerical IP address.
         * For IPv4 addresses, check whether it starts with 127.
         * For IPv6 addresses, check whether it is ::1 or its equivalent.
         * Don't check IPv4-mapped or IPv4-compatible addresses
         */

        if (host.startsWith("127.")) {
            // possible IPv4 loopback address
            int p = 4;
            int q;
            int n = host.length();
            // Per RFC2732: At most three digits per byte
            // Further constraint: Each element fits in a byte
            if ((q = scanByte(host, p, n)) <= p) return false;   p = q;
            if ((q = scan(host, p, n, '.')) <= p) return q == n && number > 0;  p = q;
            if ((q = scanByte(host, p, n)) <= p) return false;   p = q;
            if ((q = scan(host, p, n, '.')) <= p) return q == n && number > 0;  p = q;
            if ((q = scanByte(host, p, n)) <= p) return false;
            return q == n && number > 0;
        }

        if (host.endsWith(":1")) {
            return p6.matcher(host).matches();
        }
        return false;
    }

    // Character-class masks, in reverse order from RFC2396 because
    // initializers for static fields cannot make forward references.

    // Compute a low-order mask for the characters
    // between first and last, inclusive
    private static long lowMask(char first, char last) {
        long m = 0;
        int f = Math.max(Math.min(first, 63), 0);
        int l = Math.max(Math.min(last, 63), 0);
        for (int i = f; i <= l; i++)
            m |= 1L << i;
        return m;
    }
    // digit    = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" |
    //            "8" | "9"
    private static final long L_DIGIT = lowMask('0', '9');
    private static final long H_DIGIT = 0L;

    // Scan a string of decimal digits whose value fits in a byte
    //
    private int number;
    private int scanByte(String input, int start, int n)
    {
        int p = start;
        int q = scan(input, p, n, L_DIGIT, H_DIGIT);
        if (q <= p) return q;
        number = Integer.parseInt(input.substring(p, q));
        if (number > 255) return p;
        return q;
    }

    // Scan a specific char: If the char at the given start position is
    // equal to c, return the index of the next char; otherwise, return the
    // start position.
    //
    private int scan(String input, int start, int end, char c) {
        if ((start < end) && (input.charAt(start) == c))
            return start + 1;
        return start;
    }

    // Scan chars that match the given mask pair
    //
    private int scan(String input, int start, int n, long lowMask, long highMask)
    {
        int p = start;
        while (p < n) {
            char c = input.charAt(p);
            if (match(c, lowMask, highMask)) {
                p++;
                continue;
            }
            break;
        }
        return p;
    }

    // Tell whether the given character is permitted by the given mask pair
    private boolean match(char c, long lowMask, long highMask) {
        if (c < 64)
            return ((1L << c) & lowMask) != 0;
        if (c < 128)
            return ((1L << (c - 64)) & highMask) != 0;
        return false;
    }

    private native static boolean init();
    private native Proxy getSystemProxy(String protocol, String host);
}