/*
* Copyright (c) 2009, 2010, 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.
*
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package sun.net.sdp;
import sun.net.NetHooks;
import java.net.InetAddress;
import java.net.Inet4Address;
import java.net.UnknownHostException;
import java.util.*;
import java.io.File;
import java.io.FileDescriptor;
import java.io.IOException;
import java.io.PrintStream;
import java.security.AccessController;
import sun.net.sdp.SdpSupport;
import sun.security.action.GetPropertyAction;
/**
* A NetHooks provider that converts sockets from the TCP to SDP protocol prior
* to binding or connecting.
*/
public class SdpProvider extends NetHooks.Provider {
// maximum port
private static final int MAX_PORT = 65535;
// indicates if SDP is enabled and the rules for when the protocol is used
private final boolean enabled;
private final List<Rule> rules;
// logging for debug purposes
private PrintStream log;
public SdpProvider() {
// if this property is not defined then there is nothing to do.
String file = AccessController.doPrivileged(
new GetPropertyAction("com.sun.sdp.conf"));
if (file == null) {
this.enabled = false;
this.rules = null;
return;
}
// load configuration file
List<Rule> list = null;
if (file != null) {
try {
list = loadRulesFromFile(file);
} catch (IOException e) {
fail("Error reading %s: %s", file, e.getMessage());
}
}
// check if debugging is enabled
PrintStream out = null;
String logfile = AccessController.doPrivileged(
new GetPropertyAction("com.sun.sdp.debug"));
if (logfile != null) {
out = System.out;
if (logfile.length() > 0) {
try {
out = new PrintStream(logfile);
} catch (IOException ignore) { }
}
}
this.enabled = !list.isEmpty();
this.rules = list;
this.log = out;
}
// supported actions
private static enum Action {
BIND,
CONNECT;
}
// a rule for matching a bind or connect request
private static interface Rule {
boolean match(Action action, InetAddress address, int port);
}
// rule to match port[-end]
private static class PortRangeRule implements Rule {
private final Action action;
private final int portStart;
private final int portEnd;
PortRangeRule(Action action, int portStart, int portEnd) {
this.action = action;
this.portStart = portStart;
this.portEnd = portEnd;
}
Action action() {
return action;
}
@Override
public boolean match(Action action, InetAddress address, int port) {
return (action == this.action &&
port >= this.portStart &&
port <= this.portEnd);
}
}
// rule to match address[/prefix] port[-end]
private static class AddressPortRangeRule extends PortRangeRule {
private final byte[] addressAsBytes;
private final int prefixByteCount;
private final byte mask;
AddressPortRangeRule(Action action, InetAddress address,
int prefix, int port, int end)
{
super(action, port, end);
this.addressAsBytes = address.getAddress();
this.prefixByteCount = prefix >> 3;
this.mask = (byte)(0xff << (8 - (prefix % 8)));
}
@Override
public boolean match(Action action, InetAddress address, int port) {
if (action != action())
return false;
byte[] candidate = address.getAddress();
// same address type?
if (candidate.length != addressAsBytes.length)
return false;
// check bytes
for (int i=0; i<prefixByteCount; i++) {
if (candidate[i] != addressAsBytes[i])
return false;
}
// check remaining bits
if ((prefixByteCount < addressAsBytes.length) &&
((candidate[prefixByteCount] & mask) !=
(addressAsBytes[prefixByteCount] & mask)))
return false;
return super.match(action, address, port);
}
}
// parses port:[-end]
private static int[] parsePortRange(String s) {
int pos = s.indexOf('-');
try {
int[] result = new int[2];
if (pos < 0) {
boolean all = s.equals("*");
result[0] = all ? 0 : Integer.parseInt(s);
result[1] = all ? MAX_PORT : result[0];
} else {
String low = s.substring(0, pos);
if (low.length() == 0) low = "*";
String high = s.substring(pos+1);
if (high.length() == 0) high = "*";
result[0] = low.equals("*") ? 0 : Integer.parseInt(low);
result[1] = high.equals("*") ? MAX_PORT : Integer.parseInt(high);
}
return result;
} catch (NumberFormatException e) {
return new int[0];
}
}
private static void fail(String msg, Object... args) {
Formatter f = new Formatter();
f.format(msg, args);
throw new RuntimeException(f.out().toString());
}
// loads rules from the given file
// Each non-blank/non-comment line must have the format:
// ("bind" | "connect") 1*LWSP-char (hostname | ipaddress["/" prefix])
// 1*LWSP-char ("*" | port) [ "-" ("*" | port) ]
private static List<Rule> loadRulesFromFile(String file)
throws IOException
{
Scanner scanner = new Scanner(new File(file));
try {
List<Rule> result = new ArrayList<Rule>();
while (scanner.hasNextLine()) {
String line = scanner.nextLine().trim();
// skip blank lines and comments
if (line.length() == 0 || line.charAt(0) == '#')
continue;
// must have 3 fields
String[] s = line.split("\\s+");
if (s.length != 3) {
fail("Malformed line '%s'", line);
continue;
}
// first field is the action ("bind" or "connect")
Action action = null;
for (Action a: Action.values()) {
if (s[0].equalsIgnoreCase(a.name())) {
action = a;
break;
}
}
if (action == null) {
fail("Action '%s' not recognized", s[0]);
continue;
}
// * port[-end]
int[] ports = parsePortRange(s[2]);
if (ports.length == 0) {
fail("Malformed port range '%s'", s[2]);
continue;
}
// match all addresses
if (s[1].equals("*")) {
result.add(new PortRangeRule(action, ports[0], ports[1]));
continue;
}
// hostname | ipaddress[/prefix]
int pos = s[1].indexOf('/');
try {
if (pos < 0) {
// hostname or ipaddress (no prefix)
InetAddress[] addresses = InetAddress.getAllByName(s[1]);
for (InetAddress address: addresses) {
int prefix =
(address instanceof Inet4Address) ? 32 : 128;
result.add(new AddressPortRangeRule(action, address,
prefix, ports[0], ports[1]));
}
} else {
// ipaddress/prefix
InetAddress address = InetAddress
.getByName(s[1].substring(0, pos));
int prefix = -1;
try {
prefix = Integer.parseInt(s[1].substring(pos+1));
if (address instanceof Inet4Address) {
// must be 1-31
if (prefix < 0 || prefix > 32) prefix = -1;
} else {
// must be 1-128
if (prefix < 0 || prefix > 128) prefix = -1;
}
} catch (NumberFormatException e) {
}
if (prefix > 0) {
result.add(new AddressPortRangeRule(action,
address, prefix, ports[0], ports[1]));
} else {
fail("Malformed prefix '%s'", s[1]);
continue;
}
}
} catch (UnknownHostException uhe) {
fail("Unknown host or malformed IP address '%s'", s[1]);
continue;
}
}
return result;
} finally {
scanner.close();
}
}
// converts unbound TCP socket to a SDP socket if it matches the rules
private void convertTcpToSdpIfMatch(FileDescriptor fdObj,
Action action,
InetAddress address,
int port)
throws IOException
{
boolean matched = false;
for (Rule rule: rules) {
if (rule.match(action, address, port)) {
SdpSupport.convertSocket(fdObj);
matched = true;
break;
}
}
if (log != null) {
String addr = (address instanceof Inet4Address) ?
address.getHostAddress() : "[" + address.getHostAddress() + "]";
if (matched) {
log.format("%s to %s:%d (socket converted to SDP protocol)\n", action, addr, port);
} else {
log.format("%s to %s:%d (no match)\n", action, addr, port);
}
}
}
@Override
public void implBeforeTcpBind(FileDescriptor fdObj,
InetAddress address,
int port)
throws IOException
{
if (enabled)
convertTcpToSdpIfMatch(fdObj, Action.BIND, address, port);
}
@Override
public void implBeforeTcpConnect(FileDescriptor fdObj,
InetAddress address,
int port)
throws IOException
{
if (enabled)
convertTcpToSdpIfMatch(fdObj, Action.CONNECT, address, port);
}
}