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.Header;
36 import org.apache.hc.core5.http.HttpException;
37 import org.apache.hc.core5.http.HttpMessage;
38 import org.apache.hc.core5.http.MessageConstraintException;
39 import org.apache.hc.core5.http.config.Http1Config;
40 import org.apache.hc.core5.http.io.HttpMessageParser;
41 import org.apache.hc.core5.http.io.SessionInputBuffer;
42 import org.apache.hc.core5.http.message.LazyLineParser;
43 import org.apache.hc.core5.http.message.LineParser;
44 import org.apache.hc.core5.util.Args;
45 import org.apache.hc.core5.util.CharArrayBuffer;
46
47 /**
48 * Abstract base class for HTTP message parsers that obtain input from
49 * an instance of {@link org.apache.hc.core5.http.io.SessionInputBuffer}.
50 *
51 * @since 4.0
52 */
53 public abstract class AbstractMessageParser<T extends HttpMessage> implements HttpMessageParser<T> {
54
55 private static final int HEAD_LINE = 0;
56 private static final int HEADERS = 1;
57
58 private final Http1Config http1Config;
59 private final List<CharArrayBuffer> headerLines;
60 private final CharArrayBuffer headLine;
61 private final LineParser lineParser;
62
63 private int state;
64 private T message;
65
66 /**
67 * Creates new instance of AbstractMessageParser.
68 *
69 * @param lineParser the line parser. If {@code null}
70 * {@link org.apache.hc.core5.http.message.LazyLineParser#INSTANCE} will be used.
71 * @param http1Config the message http1Config. If {@code null}
72 * {@link Http1Config#DEFAULT} will be used.
73 *
74 * @since 4.3
75 */
76 public AbstractMessageParser(final LineParser lineParser, final Http1Config http1Config) {
77 super();
78 this.lineParser = lineParser != null ? lineParser : LazyLineParser.INSTANCE;
79 this.http1Config = http1Config != null ? http1Config : Http1Config.DEFAULT;
80 this.headerLines = new ArrayList<>();
81 this.headLine = new CharArrayBuffer(128);
82 this.state = HEAD_LINE;
83 }
84
85 LineParser getLineParser() {
86 return this.lineParser;
87 }
88
89 /**
90 * Parses HTTP headers from the data receiver stream according to the generic
91 * format as specified by the HTTP/1.1 protocol specification.
92 *
93 * @param inBuffer Session input buffer
94 * @param inputStream Input stream
95 * @param maxHeaderCount maximum number of headers allowed. If the number
96 * of headers received from the data stream exceeds maxCount value, an
97 * IOException will be thrown. Setting this parameter to a negative value
98 * or zero will disable the check.
99 * @param maxLineLen maximum number of characters for a header line,
100 * including the continuation lines. Setting this parameter to a negative
101 * value or zero will disable the check.
102 * @return array of HTTP headers
103 * @param lineParser the line parser. If {@code null}
104 * {@link org.apache.hc.core5.http.message.LazyLineParser#INSTANCE} will be used
105 *
106 * @throws IOException in case of an I/O error
107 * @throws HttpException in case of HTTP protocol violation
108 */
109 public static Header[] parseHeaders(
110 final SessionInputBuffer inBuffer,
111 final InputStream inputStream,
112 final int maxHeaderCount,
113 final int maxLineLen,
114 final LineParser lineParser) throws HttpException, IOException {
115 final List<CharArrayBuffer> headerLines = new ArrayList<>();
116 return parseHeaders(inBuffer, inputStream, maxHeaderCount, maxLineLen,
117 lineParser != null ? lineParser : LazyLineParser.INSTANCE, headerLines);
118 }
119
120 /**
121 * Parses HTTP headers from the data receiver stream according to the generic
122 * format as specified by the HTTP/1.1 protocol specification.
123 *
124 * @param inBuffer Session input buffer
125 * @param inputStream Input stream
126 * @param maxHeaderCount maximum number of headers allowed. If the number
127 * of headers received from the data stream exceeds maxCount value, an
128 * IOException will be thrown. Setting this parameter to a negative value
129 * or zero will disable the check.
130 * @param maxLineLen maximum number of characters for a header line,
131 * including the continuation lines. Setting this parameter to a negative
132 * value or zero will disable the check.
133 * @param parser line parser to use.
134 * @param headerLines List of header lines. This list will be used to store
135 * intermediate results. This makes it possible to resume parsing of
136 * headers in case of a {@link java.io.InterruptedIOException}.
137 *
138 * @return array of HTTP headers
139 *
140 * @throws IOException in case of an I/O error
141 * @throws HttpException in case of HTTP protocol violation
142 *
143 * @since 4.1
144 */
145 public static Header[] parseHeaders(
146 final SessionInputBuffer inBuffer,
147 final InputStream inputStream,
148 final int maxHeaderCount,
149 final int maxLineLen,
150 final LineParser parser,
151 final List<CharArrayBuffer> headerLines) throws HttpException, IOException {
152 Args.notNull(inBuffer, "Session input buffer");
153 Args.notNull(inputStream, "Input stream");
154 Args.notNull(parser, "Line parser");
155 Args.notNull(headerLines, "Header line list");
156
157 CharArrayBuffer current = null;
158 CharArrayBuffer previous = null;
159 for (;;) {
160 if (current == null) {
161 current = new CharArrayBuffer(64);
162 } else {
163 current.clear();
164 }
165 final int readLen = inBuffer.readLine(current, inputStream);
166 if (readLen == -1 || current.length() < 1) {
167 break;
168 }
169 // Parse the header name and value
170 // Check for folded headers first
171 // Detect LWS-char see HTTP/1.0 or HTTP/1.1 Section 2.2
172 // discussion on folded headers
173 if ((current.charAt(0) == ' ' || current.charAt(0) == '\t') && previous != null) {
174 // we have continuation folded header
175 // so append value
176 int i = 0;
177 while (i < current.length()) {
178 final char ch = current.charAt(i);
179 if (ch != ' ' && ch != '\t') {
180 break;
181 }
182 i++;
183 }
184 if (maxLineLen > 0
185 && previous.length() + 1 + current.length() - i > maxLineLen) {
186 throw new MessageConstraintException("Maximum line length limit exceeded");
187 }
188 previous.append(' ');
189 previous.append(current, i, current.length() - i);
190 } else {
191 headerLines.add(current);
192 previous = current;
193 current = null;
194 }
195 if (maxHeaderCount > 0 && headerLines.size() >= maxHeaderCount) {
196 throw new MessageConstraintException("Maximum header count exceeded");
197 }
198 }
199 final Headertp/Header.html#Header">Header[] headers = new Header[headerLines.size()];
200 for (int i = 0; i < headerLines.size(); i++) {
201 final CharArrayBuffer buffer = headerLines.get(i);
202 headers[i] = parser.parseHeader(buffer);
203 }
204 return headers;
205 }
206
207 /**
208 * Subclasses must override this method to generate an instance of
209 * {@link HttpMessage} based on the initial input from the session buffer.
210 * <p>
211 * Usually this method is expected to read just the very first line or
212 * the very first valid from the data stream and based on the input generate
213 * an appropriate instance of {@link HttpMessage}.
214 *
215 * @param buffer the session input buffer.
216 * @return HTTP message based on the input from the session buffer.
217 * @throws IOException in case of an I/O error.
218 * @throws HttpException in case of HTTP protocol violation.
219 *
220 * @since 5.0
221 */
222 protected abstract T createMessage(CharArrayBuffer buffer) throws IOException, HttpException;
223
224 /**
225 * Subclasses must override this method to generate an appropriate exception
226 * in case of unexpected connection termination by the peer endpoint.
227 *
228 * @since 5.0
229 */
230 protected abstract IOException createConnectionClosedException();
231
232 @Override
233 public T parse(final SessionInputBuffer buffer, final InputStream inputStream) throws IOException, HttpException {
234 Args.notNull(buffer, "Session input buffer");
235 Args.notNull(inputStream, "Input stream");
236 final int st = this.state;
237 switch (st) {
238 case HEAD_LINE:
239 for (int n = 0; n < this.http1Config.getMaxEmptyLineCount(); n++) {
240 this.headLine.clear();
241 final int i = buffer.readLine(this.headLine, inputStream);
242 if (i == -1) {
243 throw createConnectionClosedException();
244 }
245 if (this.headLine.length() > 0) {
246 this.message = createMessage(this.headLine);
247 if (this.message != null) {
248 break;
249 }
250 }
251 }
252 if (this.message == null) {
253 throw new MessageConstraintException("Maximum empty line limit exceeded");
254 }
255 this.state = HEADERS;
256 //$FALL-THROUGH$
257 case HEADERS:
258 final Header[] headers = AbstractMessageParser.parseHeaders(
259 buffer,
260 inputStream,
261 this.http1Config.getMaxHeaderCount(),
262 this.http1Config.getMaxLineLength(),
263 this.lineParser,
264 this.headerLines);
265 this.message.setHeaders(headers);
266 final T result = this.message;
267 this.message = null;
268 this.headerLines.clear();
269 this.state = HEAD_LINE;
270 return result;
271 default:
272 throw new IllegalStateException("Inconsistent parser state");
273 }
274 }
275
276 }