1/* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package libcore.net.spdy; 18 19import java.io.DataInputStream; 20import java.io.EOFException; 21import java.io.IOException; 22import java.io.InputStream; 23import java.io.UnsupportedEncodingException; 24import java.nio.charset.Charset; 25import java.util.ArrayList; 26import java.util.List; 27import java.util.logging.Logger; 28import java.util.zip.DataFormatException; 29import java.util.zip.Inflater; 30import java.util.zip.InflaterInputStream; 31import libcore.io.Streams; 32 33/** 34 * Read version 2 SPDY frames. 35 */ 36final class SpdyReader { 37 public static final Charset UTF_8 = Charset.forName("UTF-8"); 38 private static final String DICTIONARY_STRING = "" 39 + "optionsgetheadpostputdeletetraceacceptaccept-charsetaccept-encodingaccept-" 40 + "languageauthorizationexpectfromhostif-modified-sinceif-matchif-none-matchi" 41 + "f-rangeif-unmodifiedsincemax-forwardsproxy-authorizationrangerefererteuser" 42 + "-agent10010120020120220320420520630030130230330430530630740040140240340440" 43 + "5406407408409410411412413414415416417500501502503504505accept-rangesageeta" 44 + "glocationproxy-authenticatepublicretry-afterservervarywarningwww-authentic" 45 + "ateallowcontent-basecontent-encodingcache-controlconnectiondatetrailertran" 46 + "sfer-encodingupgradeviawarningcontent-languagecontent-lengthcontent-locati" 47 + "oncontent-md5content-rangecontent-typeetagexpireslast-modifiedset-cookieMo" 48 + "ndayTuesdayWednesdayThursdayFridaySaturdaySundayJanFebMarAprMayJunJulAugSe" 49 + "pOctNovDecchunkedtext/htmlimage/pngimage/jpgimage/gifapplication/xmlapplic" 50 + "ation/xhtmltext/plainpublicmax-agecharset=iso-8859-1utf-8gzipdeflateHTTP/1" 51 + ".1statusversionurl\0"; 52 public static final byte[] DICTIONARY; 53 static { 54 try { 55 DICTIONARY = DICTIONARY_STRING.getBytes("UTF-8"); 56 } catch (UnsupportedEncodingException e) { 57 throw new AssertionError(e); 58 } 59 } 60 61 public final DataInputStream in; 62 public int flags; 63 public int length; 64 public int streamId; 65 public int associatedStreamId; 66 public int version; 67 public int type; 68 public int priority; 69 public int statusCode; 70 71 public List<String> nameValueBlock; 72 private final DataInputStream nameValueBlockIn; 73 private int compressedLimit; 74 75 SpdyReader(InputStream in) { 76 this.in = new DataInputStream(in); 77 this.nameValueBlockIn = newNameValueBlockStream(); 78 } 79 80 /** 81 * Advance to the next frame in the source data. If the frame is of 82 * TYPE_DATA, it's the caller's responsibility to read length bytes from 83 * the input stream before the next call to nextFrame(). 84 */ 85 public int nextFrame() throws IOException { 86 int w1; 87 try { 88 w1 = in.readInt(); 89 } catch (EOFException e) { 90 return SpdyConnection.TYPE_EOF; 91 } 92 int w2 = in.readInt(); 93 94 boolean control = (w1 & 0x80000000) != 0; 95 flags = (w2 & 0xff000000) >>> 24; 96 length = (w2 & 0xffffff); 97 98 if (control) { 99 version = (w1 & 0x7fff0000) >>> 16; 100 type = (w1 & 0xffff); 101 102 switch (type) { 103 case SpdyConnection.TYPE_SYN_STREAM: 104 readSynStream(); 105 return SpdyConnection.TYPE_SYN_STREAM; 106 107 case SpdyConnection.TYPE_SYN_REPLY: 108 readSynReply(); 109 return SpdyConnection.TYPE_SYN_REPLY; 110 111 case SpdyConnection.TYPE_RST_STREAM: 112 readSynReset(); 113 return SpdyConnection.TYPE_RST_STREAM; 114 115 default: 116 readControlFrame(); 117 return type; 118 } 119 } else { 120 streamId = w1 & 0x7fffffff; 121 return SpdyConnection.TYPE_DATA; 122 } 123 } 124 125 private void readSynStream() throws IOException { 126 int w1 = in.readInt(); 127 int w2 = in.readInt(); 128 int s3 = in.readShort(); 129 streamId = w1 & 0x7fffffff; 130 associatedStreamId = w2 & 0x7fffffff; 131 priority = s3 & 0xc000 >> 14; 132 // int unused = s3 & 0x3fff; 133 nameValueBlock = readNameValueBlock(length - 10); 134 } 135 136 private void readSynReply() throws IOException { 137 int w1 = in.readInt(); 138 in.readShort(); // unused 139 streamId = w1 & 0x7fffffff; 140 nameValueBlock = readNameValueBlock(length - 6); 141 } 142 143 private void readSynReset() throws IOException { 144 streamId = in.readInt() & 0x7fffffff; 145 statusCode = in.readInt(); 146 } 147 148 private void readControlFrame() throws IOException { 149 Streams.skipByReading(in, length); 150 } 151 152 private DataInputStream newNameValueBlockStream() { 153 // Limit the inflater input stream to only those bytes in the Name/Value block. 154 final InputStream throttleStream = new InputStream() { 155 @Override public int read() throws IOException { 156 return Streams.readSingleByte(this); 157 } 158 159 @Override public int read(byte[] buffer, int offset, int byteCount) throws IOException { 160 byteCount = Math.min(byteCount, compressedLimit); 161 int consumed = in.read(buffer, offset, byteCount); 162 compressedLimit -= consumed; 163 return consumed; 164 } 165 166 @Override public void close() throws IOException { 167 in.close(); 168 } 169 }; 170 171 // Subclass inflater to install a dictionary when it's needed. 172 Inflater inflater = new Inflater() { 173 @Override 174 public int inflate(byte[] buffer, int offset, int count) throws DataFormatException { 175 int result = super.inflate(buffer, offset, count); 176 if (result == 0 && needsDictionary()) { 177 setDictionary(DICTIONARY); 178 result = super.inflate(buffer, offset, count); 179 } 180 return result; 181 } 182 }; 183 184 return new DataInputStream(new InflaterInputStream(throttleStream, inflater)); 185 } 186 187 private List<String> readNameValueBlock(int length) throws IOException { 188 this.compressedLimit += length; 189 try { 190 List<String> entries = new ArrayList<String>(); 191 192 int numberOfPairs = nameValueBlockIn.readShort(); 193 for (int i = 0; i < numberOfPairs; i++) { 194 String name = readString(); 195 String values = readString(); 196 if (name.length() == 0 || values.length() == 0) { 197 throw new IOException(); // TODO: PROTOCOL ERROR 198 } 199 entries.add(name); 200 entries.add(values); 201 } 202 203 if (compressedLimit != 0) { 204 Logger.getLogger(getClass().getName()) 205 .warning("compressedLimit > 0" + compressedLimit); 206 } 207 208 return entries; 209 } catch (DataFormatException e) { 210 throw new IOException(e); 211 } 212 } 213 214 private String readString() throws DataFormatException, IOException { 215 int length = nameValueBlockIn.readShort(); 216 byte[] bytes = new byte[length]; 217 Streams.readFully(nameValueBlockIn, bytes); 218 return new String(bytes, 0, length, "UTF-8"); 219 } 220} 221