1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27
28 package org.apache.hc.core5.http.impl.io;
29
30 import java.io.IOException;
31 import java.io.InputStream;
32 import java.util.ArrayList;
33 import java.util.List;
34
35 import org.apache.hc.core5.http.ConnectionClosedException;
36 import org.apache.hc.core5.http.Header;
37 import org.apache.hc.core5.http.HttpException;
38 import org.apache.hc.core5.http.HttpMessage;
39 import org.apache.hc.core5.http.MessageConstraintException;
40 import org.apache.hc.core5.http.config.Http1Config;
41 import org.apache.hc.core5.http.io.HttpMessageParser;
42 import org.apache.hc.core5.http.io.SessionInputBuffer;
43 import org.apache.hc.core5.http.message.LazyLineParser;
44 import org.apache.hc.core5.http.message.LineParser;
45 import org.apache.hc.core5.util.Args;
46 import org.apache.hc.core5.util.CharArrayBuffer;
47
48 /**
49 * Abstract base class for HTTP message parsers that obtain input from
50 * an instance of {@link org.apache.hc.core5.http.io.SessionInputBuffer}.
51 *
52 * @since 4.0
53 */
54 public abstract class AbstractMessageParser<T extends HttpMessage> implements HttpMessageParser<T> {
55
56 private static final int HEAD_LINE = 0;
57 private static final int HEADERS = 1;
58
59 private final Http1Config http1Config;
60 private final List<CharArrayBuffer> headerLines;
61 private final CharArrayBuffer headLine;
62 private final LineParser lineParser;
63
64 private int state;
65 private T message;
66
67 /**
68 * Creates new instance of AbstractMessageParser.
69 *
70 * @param lineParser the line parser. If {@code null}
71 * {@link org.apache.hc.core5.http.message.LazyLineParser#INSTANCE} will be used.
72 * @param http1Config the message http1Config. If {@code null}
73 * {@link Http1Config#DEFAULT} will be used.
74 *
75 * @since 4.3
76 */
77 public AbstractMessageParser(final LineParser lineParser, final Http1Config http1Config) {
78 super();
79 this.lineParser = lineParser != null ? lineParser : LazyLineParser.INSTANCE;
80 this.http1Config = http1Config != null ? http1Config : Http1Config.DEFAULT;
81 this.headerLines = new ArrayList<>();
82 this.headLine = new CharArrayBuffer(128);
83 this.state = HEAD_LINE;
84 }
85
86 LineParser getLineParser() {
87 return this.lineParser;
88 }
89
90 /**
91 * Parses HTTP headers from the data receiver stream according to the generic
92 * format as specified by the HTTP/1.1 protocol specification.
93 *
94 * @param inBuffer Session input buffer
95 * @param inputStream Input stream
96 * @param maxHeaderCount maximum number of headers allowed. If the number
97 * of headers received from the data stream exceeds maxCount value, an
98 * IOException will be thrown. Setting this parameter to a negative value
99 * or zero will disable the check.
100 * @param maxLineLen maximum number of characters for a header line,
101 * including the continuation lines. Setting this parameter to a negative
102 * value or zero will disable the check.
103 * @return array of HTTP headers
104 * @param lineParser the line parser. If {@code null}
105 * {@link org.apache.hc.core5.http.message.LazyLineParser#INSTANCE} will be used
106 *
107 * @throws IOException in case of an I/O error
108 * @throws HttpException in case of HTTP protocol violation
109 */
110 public static Header[] parseHeaders(
111 final SessionInputBuffer inBuffer,
112 final InputStream inputStream,
113 final int maxHeaderCount,
114 final int maxLineLen,
115 final LineParser lineParser) throws HttpException, IOException {
116 final List<CharArrayBuffer> headerLines = new ArrayList<>();
117 return parseHeaders(inBuffer, inputStream, maxHeaderCount, maxLineLen,
118 lineParser != null ? lineParser : LazyLineParser.INSTANCE, headerLines);
119 }
120
121 /**
122 * Parses HTTP headers from the data receiver stream according to the generic
123 * format as specified by the HTTP/1.1 protocol specification.
124 *
125 * @param inBuffer Session input buffer
126 * @param inputStream Input stream
127 * @param maxHeaderCount maximum number of headers allowed. If the number
128 * of headers received from the data stream exceeds maxCount value, an
129 * IOException will be thrown. Setting this parameter to a negative value
130 * or zero will disable the check.
131 * @param maxLineLen maximum number of characters for a header line,
132 * including the continuation lines. Setting this parameter to a negative
133 * value or zero will disable the check.
134 * @param parser line parser to use.
135 * @param headerLines List of header lines. This list will be used to store
136 * intermediate results. This makes it possible to resume parsing of
137 * headers in case of a {@link java.io.InterruptedIOException}.
138 *
139 * @return array of HTTP headers
140 *
141 * @throws IOException in case of an I/O error
142 * @throws HttpException in case of HTTP protocol violation
143 *
144 * @since 4.1
145 */
146 public static Header[] parseHeaders(
147 final SessionInputBuffer inBuffer,
148 final InputStream inputStream,
149 final int maxHeaderCount,
150 final int maxLineLen,
151 final LineParser parser,
152 final List<CharArrayBuffer> headerLines) throws HttpException, IOException {
153 Args.notNull(inBuffer, "Session input buffer");
154 Args.notNull(inputStream, "Input stream");
155 Args.notNull(parser, "Line parser");
156 Args.notNull(headerLines, "Header line list");
157
158 CharArrayBuffer current = null;
159 CharArrayBuffer previous = null;
160 for (;;) {
161 if (current == null) {
162 current = new CharArrayBuffer(64);
163 } else {
164 current.clear();
165 }
166 final int readLen = inBuffer.readLine(current, inputStream);
167 if (readLen == -1 || current.length() < 1) {
168 break;
169 }
170 // Parse the header name and value
171 // Check for folded headers first
172 // Detect LWS-char see HTTP/1.0 or HTTP/1.1 Section 2.2
173 // discussion on folded headers
174 if ((current.charAt(0) == ' ' || current.charAt(0) == '\t') && previous != null) {
175 // we have continuation folded header
176 // so append value
177 int i = 0;
178 while (i < current.length()) {
179 final char ch = current.charAt(i);
180 if (ch != ' ' && ch != '\t') {
181 break;
182 }
183 i++;
184 }
185 if (maxLineLen > 0
186 && previous.length() + 1 + current.length() - i > maxLineLen) {
187 throw new MessageConstraintException("Maximum line length limit exceeded");
188 }
189 previous.append(' ');
190 previous.append(current, i, current.length() - i);
191 } else {
192 headerLines.add(current);
193 previous = current;
194 current = null;
195 }
196 if (maxHeaderCount > 0 && headerLines.size() >= maxHeaderCount) {
197 throw new MessageConstraintException("Maximum header count exceeded");
198 }
199 }
200 final Header[] headers = new Header[headerLines.size()];
201 for (int i = 0; i < headerLines.size(); i++) {
202 final CharArrayBuffer buffer = headerLines.get(i);
203 headers[i] = parser.parseHeader(buffer);
204 }
205 return headers;
206 }
207
208 /**
209 * Subclasses must override this method to generate an instance of
210 * {@link HttpMessage} based on the initial input from the session buffer.
211 * <p>
212 * Usually this method is expected to read just the very first line or
213 * the very first valid from the data stream and based on the input generate
214 * an appropriate instance of {@link HttpMessage}.
215 *
216 * @param buffer the session input buffer.
217 * @return HTTP message based on the input from the session buffer.
218 * @throws IOException in case of an I/O error.
219 * @throws HttpException in case of HTTP protocol violation.
220 *
221 * @since 5.0
222 */
223 protected abstract T createMessage(CharArrayBuffer buffer) throws IOException, HttpException;
224
225 /**
226 * Subclasses must override this method to generate an appropriate exception
227 * in case of unexpected connection termination by the peer endpoint.
228 *
229 * @since 5.0
230 *
231 * @deprecated do not use.
232 */
233 @Deprecated
234 protected IOException createConnectionClosedException() {
235 return new ConnectionClosedException();
236 }
237
238 @Override
239 public T parse(final SessionInputBuffer buffer, final InputStream inputStream) throws IOException, HttpException {
240 Args.notNull(buffer, "Session input buffer");
241 Args.notNull(inputStream, "Input stream");
242 final int st = this.state;
243 switch (st) {
244 case HEAD_LINE:
245 for (int n = 0; n < this.http1Config.getMaxEmptyLineCount(); n++) {
246 this.headLine.clear();
247 final int i = buffer.readLine(this.headLine, inputStream);
248 if (i == -1) {
249 return null;
250 }
251 if (this.headLine.length() > 0) {
252 this.message = createMessage(this.headLine);
253 if (this.message != null) {
254 break;
255 }
256 }
257 }
258 if (this.message == null) {
259 throw new MessageConstraintException("Maximum empty line limit exceeded");
260 }
261 this.state = HEADERS;
262 //$FALL-THROUGH$
263 case HEADERS:
264 final Header[] headers = AbstractMessageParser.parseHeaders(
265 buffer,
266 inputStream,
267 this.http1Config.getMaxHeaderCount(),
268 this.http1Config.getMaxLineLength(),
269 this.lineParser,
270 this.headerLines);
271 this.message.setHeaders(headers);
272 final T result = this.message;
273 this.message = null;
274 this.headerLines.clear();
275 this.state = HEAD_LINE;
276 return result;
277 default:
278 throw new IllegalStateException("Inconsistent parser state");
279 }
280 }
281
282 }