1 /*
2 * Copyright (c) 1996, 2012, 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 package sun.rmi.transport.proxy;
26
27 import java.io.*;
28
29 import sun.rmi.runtime.Log;
30
31 /**
32 * The HttpInputStream class assists the HttpSendSocket and HttpReceiveSocket
33 * classes by filtering out the header for the message as well as any
34 * data after its proper content length.
35 */
36 class HttpInputStream extends FilterInputStream {
37
38 /** bytes remaining to be read from proper content of message */
39 protected int bytesLeft;
40
41 /** bytes remaining to be read at time of last mark */
42 protected int bytesLeftAtMark;
43
44 /**
45 * Create new filter on a given input stream.
46 * @param in the InputStream to filter from
47 */
48 public HttpInputStream(InputStream in) throws IOException
49 {
50 super(in);
51
52 if (in.markSupported())
53 in.mark(0); // prevent resetting back to old marks
54
55 // pull out header, looking for content length
56
57 DataInputStream dis = new DataInputStream(in);
58 String key = "Content-length:".toLowerCase();
59 boolean contentLengthFound = false;
60 String line;
61 do {
62 line = dis.readLine();
63
64 if (RMIMasterSocketFactory.proxyLog.isLoggable(Log.VERBOSE)) {
65 RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
66 "received header line: \"" + line + "\"");
67 }
68
69 if (line == null)
70 throw new EOFException();
71
72 if (line.toLowerCase().startsWith(key)) {
73 if (contentLengthFound) {
74 throw new IOException(
75 "Multiple Content-length entries found.");
76 } else {
77 bytesLeft =
78 Integer.parseInt(line.substring(key.length()).trim());
79 contentLengthFound = true;
80 }
81 }
82
83 // The idea here is to go past the first blank line.
84 // Some DataInputStream.readLine() documentation specifies that
85 // it does include the line-terminating character(s) in the
86 // returned string, but it actually doesn't, so we'll cover
87 // all cases here...
88 } while ((line.length() != 0) &&
89 (line.charAt(0) != '\r') && (line.charAt(0) != '\n'));
90
91 if (!contentLengthFound || bytesLeft < 0) {
92 // This really shouldn't happen, but if it does, shoud we fail??
93 // For now, just give up and let a whole lot of bytes through...
94 bytesLeft = Integer.MAX_VALUE;
95 }
96 bytesLeftAtMark = bytesLeft;
97
98 if (RMIMasterSocketFactory.proxyLog.isLoggable(Log.VERBOSE)) {
99 RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
100 "content length: " + bytesLeft);
101 }
102 }
103
104 /**
105 * Returns the number of bytes that can be read with blocking.
106 * Make sure that this does not exceed the number of bytes remaining
107 * in the proper content of the message.
108 */
109 public int available() throws IOException
110 {
111 int bytesAvailable = in.available();
112 if (bytesAvailable > bytesLeft)
113 bytesAvailable = bytesLeft;
114
115 return bytesAvailable;
116 }
117
118 /**
119 * Read a byte of data from the stream. Make sure that one is available
120 * from the proper content of the message, else -1 is returned to
121 * indicate to the user that the end of the stream has been reached.
122 */
123 public int read() throws IOException
124 {
125 if (bytesLeft > 0) {
126 int data = in.read();
127 if (data != -1)
128 -- bytesLeft;
129
130 if (RMIMasterSocketFactory.proxyLog.isLoggable(Log.VERBOSE)) {
131 RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
132 "received byte: '" +
133 ((data & 0x7F) < ' ' ? " " : String.valueOf((char) data)) +
134 "' " + data);
135 }
136
137 return data;
138 }
139 else {
140 RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
141 "read past content length");
142
143 return -1;
144 }
145 }
146
147 public int read(byte b[], int off, int len) throws IOException
148 {
149 if (bytesLeft == 0 && len > 0) {
150 RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
151 "read past content length");
152
153 return -1;
154 }
155 if (len > bytesLeft)
156 len = bytesLeft;
157 int bytesRead = in.read(b, off, len);
158 bytesLeft -= bytesRead;
159
160 if (RMIMasterSocketFactory.proxyLog.isLoggable(Log.VERBOSE)) {
161 RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
162 "read " + bytesRead + " bytes, " + bytesLeft + " remaining");
163 }
164
165 return bytesRead;
166 }
167
168 /**
169 * Mark the current position in the stream (for future calls to reset).
170 * Remember where we are within the proper content of the message, so
171 * that a reset method call can recreate our state properly.
172 * @param readlimit how many bytes can be read before mark becomes invalid
173 */
174 public void mark(int readlimit)
175 {
176 in.mark(readlimit);
177 if (in.markSupported())
178 bytesLeftAtMark = bytesLeft;
179 }
180
181 /**
182 * Repositions the stream to the last marked position. Make sure to
183 * adjust our position within the proper content accordingly.
184 */
185 public void reset() throws IOException
186 {
187 in.reset();
188 bytesLeft = bytesLeftAtMark;
189 }
190
191 /**
192 * Skips bytes of the stream. Make sure to adjust our
193 * position within the proper content accordingly.
194 * @param n number of bytes to be skipped
195 */
196 public long skip(long n) throws IOException
197 {
198 if (n > bytesLeft)
199 n = bytesLeft;
200 long bytesSkipped = in.skip(n);
201 bytesLeft -= bytesSkipped;
202 return bytesSkipped;
203 }
204 }