1 /*
2 * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package sun.net.sdp;
27
28 import sun.net.NetHooks;
29 import java.net.InetAddress;
30 import java.net.Inet4Address;
31 import java.net.UnknownHostException;
32 import java.util.*;
33 import java.io.File;
34 import java.io.FileDescriptor;
35 import java.io.IOException;
36 import java.io.PrintStream;
37
38 import sun.net.sdp.SdpSupport;
39 import sun.security.action.GetPropertyAction;
40
41 /**
42 * A NetHooks provider that converts sockets from the TCP to SDP protocol prior
43 * to binding or connecting.
44 */
45
46 public class SdpProvider extends NetHooks.Provider {
47 // maximum port
48 private static final int MAX_PORT = 65535;
49
50 // indicates if SDP is enabled and the rules for when the protocol is used
51 private final boolean enabled;
52 private final List<Rule> rules;
53
54 // logging for debug purposes
55 private PrintStream log;
56
57 public SdpProvider() {
58 // if this property is not defined then there is nothing to do.
59 String file = GetPropertyAction.getProperty("com.sun.sdp.conf");
60 if (file == null) {
61 this.enabled = false;
62 this.rules = null;
63 return;
64 }
65
66 // load configuration file
67 List<Rule> list = null;
68 if (file != null) {
69 try {
70 list = loadRulesFromFile(file);
71 } catch (IOException e) {
72 fail("Error reading %s: %s", file, e.getMessage());
73 }
74 }
75
76 // check if debugging is enabled
77 PrintStream out = null;
78 String logfile = GetPropertyAction.getProperty("com.sun.sdp.debug");
79 if (logfile != null) {
80 out = System.out;
81 if (logfile.length() > 0) {
82 try {
83 out = new PrintStream(logfile);
84 } catch (IOException ignore) { }
85 }
86 }
87
88 this.enabled = !list.isEmpty();
89 this.rules = list;
90 this.log = out;
91 }
92
93 // supported actions
94 private static enum Action {
95 BIND,
96 CONNECT;
97 }
98
99 // a rule for matching a bind or connect request
100 private static interface Rule {
101 boolean match(Action action, InetAddress address, int port);
102 }
103
104 // rule to match port[-end]
105 private static class PortRangeRule implements Rule {
106 private final Action action;
107 private final int portStart;
108 private final int portEnd;
109 PortRangeRule(Action action, int portStart, int portEnd) {
110 this.action = action;
111 this.portStart = portStart;
112 this.portEnd = portEnd;
113 }
114 Action action() {
115 return action;
116 }
117 @Override
118 public boolean match(Action action, InetAddress address, int port) {
119 return (action == this.action &&
120 port >= this.portStart &&
121 port <= this.portEnd);
122 }
123 }
124
125 // rule to match address[/prefix] port[-end]
126 private static class AddressPortRangeRule extends PortRangeRule {
127 private final byte[] addressAsBytes;
128 private final int prefixByteCount;
129 private final byte mask;
130 AddressPortRangeRule(Action action, InetAddress address,
131 int prefix, int port, int end)
132 {
133 super(action, port, end);
134 this.addressAsBytes = address.getAddress();
135 this.prefixByteCount = prefix >> 3;
136 this.mask = (byte)(0xff << (8 - (prefix % 8)));
137 }
138 @Override
139 public boolean match(Action action, InetAddress address, int port) {
140 if (action != action())
141 return false;
142 byte[] candidate = address.getAddress();
143 // same address type?
144 if (candidate.length != addressAsBytes.length)
145 return false;
146 // check bytes
147 for (int i=0; i<prefixByteCount; i++) {
148 if (candidate[i] != addressAsBytes[i])
149 return false;
150 }
151 // check remaining bits
152 if ((prefixByteCount < addressAsBytes.length) &&
153 ((candidate[prefixByteCount] & mask) !=
154 (addressAsBytes[prefixByteCount] & mask)))
155 return false;
156 return super.match(action, address, port);
157 }
158 }
159
160 // parses port:[-end]
161 private static int[] parsePortRange(String s) {
162 int pos = s.indexOf('-');
163 try {
164 int[] result = new int[2];
165 if (pos < 0) {
166 boolean all = s.equals("*");
167 result[0] = all ? 0 : Integer.parseInt(s);
168 result[1] = all ? MAX_PORT : result[0];
169 } else {
170 String low = s.substring(0, pos);
171 if (low.length() == 0) low = "*";
172 String high = s.substring(pos+1);
173 if (high.length() == 0) high = "*";
174 result[0] = low.equals("*") ? 0 : Integer.parseInt(low);
175 result[1] = high.equals("*") ? MAX_PORT : Integer.parseInt(high);
176 }
177 return result;
178 } catch (NumberFormatException e) {
179 return new int[0];
180 }
181 }
182
183 private static void fail(String msg, Object... args) {
184 Formatter f = new Formatter();
185 f.format(msg, args);
186 throw new RuntimeException(f.out().toString());
187 }
188
189 // loads rules from the given file
190 // Each non-blank/non-comment line must have the format:
191 // ("bind" | "connect") 1*LWSP-char (hostname | ipaddress["/" prefix])
192 // 1*LWSP-char ("*" | port) [ "-" ("*" | port) ]
193 private static List<Rule> loadRulesFromFile(String file)
194 throws IOException
195 {
196 Scanner scanner = new Scanner(new File(file));
197 try {
198 List<Rule> result = new ArrayList<>();
199 while (scanner.hasNextLine()) {
200 String line = scanner.nextLine().trim();
201
202 // skip blank lines and comments
203 if (line.length() == 0 || line.charAt(0) == '#')
204 continue;
205
206 // must have 3 fields
207 String[] s = line.split("\\s+");
208 if (s.length != 3) {
209 fail("Malformed line '%s'", line);
210 continue;
211 }
212
213 // first field is the action ("bind" or "connect")
214 Action action = null;
215 for (Action a: Action.values()) {
216 if (s[0].equalsIgnoreCase(a.name())) {
217 action = a;
218 break;
219 }
220 }
221 if (action == null) {
222 fail("Action '%s' not recognized", s[0]);
223 continue;
224 }
225
226 // * port[-end]
227 int[] ports = parsePortRange(s[2]);
228 if (ports.length == 0) {
229 fail("Malformed port range '%s'", s[2]);
230 continue;
231 }
232
233 // match all addresses
234 if (s[1].equals("*")) {
235 result.add(new PortRangeRule(action, ports[0], ports[1]));
236 continue;
237 }
238
239 // hostname | ipaddress[/prefix]
240 int pos = s[1].indexOf('/');
241 try {
242 if (pos < 0) {
243 // hostname or ipaddress (no prefix)
244 InetAddress[] addresses = InetAddress.getAllByName(s[1]);
245 for (InetAddress address: addresses) {
246 int prefix =
247 (address instanceof Inet4Address) ? 32 : 128;
248 result.add(new AddressPortRangeRule(action, address,
249 prefix, ports[0], ports[1]));
250 }
251 } else {
252 // ipaddress/prefix
253 InetAddress address = InetAddress
254 .getByName(s[1].substring(0, pos));
255 int prefix = -1;
256 try {
257 prefix = Integer.parseInt(s[1], pos + 1,
258 s[1].length(), 10);
259 if (address instanceof Inet4Address) {
260 // must be 1-31
261 if (prefix < 0 || prefix > 32) prefix = -1;
262 } else {
263 // must be 1-128
264 if (prefix < 0 || prefix > 128) prefix = -1;
265 }
266 } catch (NumberFormatException e) {
267 }
268
269 if (prefix > 0) {
270 result.add(new AddressPortRangeRule(action,
271 address, prefix, ports[0], ports[1]));
272 } else {
273 fail("Malformed prefix '%s'", s[1]);
274 continue;
275 }
276 }
277 } catch (UnknownHostException uhe) {
278 fail("Unknown host or malformed IP address '%s'", s[1]);
279 continue;
280 }
281 }
282 return result;
283 } finally {
284 scanner.close();
285 }
286 }
287
288 // converts unbound TCP socket to a SDP socket if it matches the rules
289 private void convertTcpToSdpIfMatch(FileDescriptor fdObj,
290 Action action,
291 InetAddress address,
292 int port)
293 throws IOException
294 {
295 boolean matched = false;
296 for (Rule rule: rules) {
297 if (rule.match(action, address, port)) {
298 SdpSupport.convertSocket(fdObj);
299 matched = true;
300 break;
301 }
302 }
303 if (log != null) {
304 String addr = (address instanceof Inet4Address) ?
305 address.getHostAddress() : "[" + address.getHostAddress() + "]";
306 if (matched) {
307 log.format("%s to %s:%d (socket converted to SDP protocol)\n", action, addr, port);
308 } else {
309 log.format("%s to %s:%d (no match)\n", action, addr, port);
310 }
311 }
312 }
313
314 @Override
315 public void implBeforeTcpBind(FileDescriptor fdObj,
316 InetAddress address,
317 int port)
318 throws IOException
319 {
320 if (enabled)
321 convertTcpToSdpIfMatch(fdObj, Action.BIND, address, port);
322 }
323
324 @Override
325 public void implBeforeTcpConnect(FileDescriptor fdObj,
326 InetAddress address,
327 int port)
328 throws IOException
329 {
330 if (enabled)
331 convertTcpToSdpIfMatch(fdObj, Action.CONNECT, address, port);
332 }
333 }