1 /*

     2  * Copyright (c) 2017, 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 jdk.incubator.http;

    27 

    28 import java.net.ProtocolException;

    29 import java.nio.ByteBuffer;

    30 import java.util.ArrayList;

    31 import java.util.HashMap;

    32 import java.util.List;

    33 import java.util.Locale;

    34 import java.util.Map;

    35 import static java.lang.String.format;

    36 import static java.util.Objects.requireNonNull;

    37 

    38 class Http1HeaderParser {

    39 

    40     private static final char CR = '\r';

    41     private static final char LF = '\n';

    42     private static final char HT = '\t';

    43     private static final char SP = ' ';

    44 

    45     private StringBuilder sb = new StringBuilder();

    46     private String statusLine;

    47     private int responseCode;

    48     private HttpHeaders headers;

    49     private Map<String,List<String>> privateMap = new HashMap<>();

    50 

    51     enum State { STATUS_LINE,

    52                  STATUS_LINE_FOUND_CR,

    53                  STATUS_LINE_END,

    54                  STATUS_LINE_END_CR,

    55                  HEADER,

    56                  HEADER_FOUND_CR,

    57                  HEADER_FOUND_LF,

    58                  HEADER_FOUND_CR_LF,

    59                  HEADER_FOUND_CR_LF_CR,

    60                  FINISHED }

    61 

    62     private State state = State.STATUS_LINE;

    63 

    64     /** Returns the status-line. */

    65     String statusLine() { return statusLine; }

    66 

    67     /** Returns the response code. */

    68     int responseCode() { return responseCode; }

    69 

    70     /** Returns the headers, possibly empty. */

    71     HttpHeaders headers() { assert state == State.FINISHED; return headers; }

    72 

    73     /**

    74      * Parses HTTP/1.X status-line and headers from the given bytes. Must be

    75      * called successive times, with additional data, until returns true.

    76      *

    77      * All given ByteBuffers will be consumed, until ( possibly ) the last one

    78      * ( when true is returned ), which may not be fully consumed.

    79      *

    80      * @param input the ( partial ) header data

    81      * @return true iff the end of the headers block has been reached

    82      */

    83     boolean parse(ByteBuffer input) throws ProtocolException {

    84         requireNonNull(input, "null input");

    85 

    86         while (input.hasRemaining() && state != State.FINISHED) {

    87             switch (state) {

    88                 case STATUS_LINE:

    89                     readResumeStatusLine(input);

    90                     break;

    91                 case STATUS_LINE_FOUND_CR:

    92                     readStatusLineFeed(input);

    93                     break;

    94                 case STATUS_LINE_END:

    95                     maybeStartHeaders(input);

    96                     break;

    97                 case STATUS_LINE_END_CR:

    98                     maybeEndHeaders(input);

    99                     break;

   100                 case HEADER:

   101                     readResumeHeader(input);

   102                     break;

   103                 // fallthrough

   104                 case HEADER_FOUND_CR:

   105                 case HEADER_FOUND_LF:

   106                     resumeOrLF(input);

   107                     break;

   108                 case HEADER_FOUND_CR_LF:

   109                     resumeOrSecondCR(input);

   110                     break;

   111                 case HEADER_FOUND_CR_LF_CR:

   112                     resumeOrEndHeaders(input);

   113                     break;

   114                 default:

   115                     throw new InternalError(

   116                             "Unexpected state: " + String.valueOf(state));

   117             }

   118         }

   119 

   120         return state == State.FINISHED;

   121     }

   122 

   123     private void readResumeStatusLine(ByteBuffer input) {

   124         char c = 0;

   125         while (input.hasRemaining() && (c =(char)input.get()) != CR) {

   126             sb.append(c);

   127         }

   128 

   129         if (c == CR) {

   130             state = State.STATUS_LINE_FOUND_CR;

   131         }

   132     }

   133 

   134     private void readStatusLineFeed(ByteBuffer input) throws ProtocolException {

   135         char c = (char)input.get();

   136         if (c != LF) {

   137             throw protocolException("Bad trailing char, \"%s\", when parsing status-line, \"%s\"",

   138                                     c, sb.toString());

   139         }

   140 

   141         statusLine = sb.toString();

   142         sb = new StringBuilder();

   143         if (!statusLine.startsWith("HTTP/1.")) {

   144             throw protocolException("Invalid status line: \"%s\"", statusLine);

   145         }

   146         if (statusLine.length() < 12) {

   147             throw protocolException("Invalid status line: \"%s\"", statusLine);

   148         }

   149         responseCode = Integer.parseInt(statusLine.substring(9, 12));

   150 

   151         state = State.STATUS_LINE_END;

   152     }

   153 

   154     private void maybeStartHeaders(ByteBuffer input) {

   155         assert state == State.STATUS_LINE_END;

   156         assert sb.length() == 0;

   157         char c = (char)input.get();

   158         if (c == CR) {

   159             state = State.STATUS_LINE_END_CR;

   160         } else {

   161             sb.append(c);

   162             state = State.HEADER;

   163         }

   164     }

   165 

   166     private void maybeEndHeaders(ByteBuffer input) throws ProtocolException {

   167         assert state == State.STATUS_LINE_END_CR;

   168         assert sb.length() == 0;

   169         char c = (char)input.get();

   170         if (c == LF) {

   171             headers = ImmutableHeaders.of(privateMap);

   172             privateMap = null;

   173             state = State.FINISHED;  // no headers

   174         } else {

   175             throw protocolException("Unexpected \"%s\", after status-line CR", c);

   176         }

   177     }

   178 

   179     private void readResumeHeader(ByteBuffer input) {

   180         assert state == State.HEADER;

   181         assert input.hasRemaining();

   182         while (input.hasRemaining()) {

   183             char c = (char)input.get();

   184             if (c == CR) {

   185                 state = State.HEADER_FOUND_CR;

   186                 break;

   187             } else if (c == LF) {

   188                 state = State.HEADER_FOUND_LF;

   189                 break;

   190             }

   191 

   192             if (c == HT)

   193                 c = SP;

   194             sb.append(c);

   195         }

   196     }

   197 

   198     private void addHeaderFromString(String headerString) {

   199         assert sb.length() == 0;

   200         int idx = headerString.indexOf(':');

   201         if (idx == -1)

   202             return;

   203         String name = headerString.substring(0, idx).trim();

   204         if (name.isEmpty())

   205             return;

   206         String value = headerString.substring(idx + 1, headerString.length()).trim();

   207 

   208         privateMap.computeIfAbsent(name.toLowerCase(Locale.US),

   209                                    k -> new ArrayList<>()).add(value);

   210     }

   211 

   212     private void resumeOrLF(ByteBuffer input) {

   213         assert state == State.HEADER_FOUND_CR || state == State.HEADER_FOUND_LF;

   214         char c = (char)input.get();

   215         if (c == LF && state == State.HEADER_FOUND_CR) {

   216             String headerString = sb.toString();

   217             sb = new StringBuilder();

   218             addHeaderFromString(headerString);

   219             state = State.HEADER_FOUND_CR_LF;

   220         } else if (c == SP || c == HT) {

   221             sb.append(SP); // parity with MessageHeaders

   222             state = State.HEADER;

   223         } else {

   224             sb = new StringBuilder();

   225             sb.append(c);

   226             state = State.HEADER;

   227         }

   228     }

   229 

   230     private void resumeOrSecondCR(ByteBuffer input) {

   231         assert state == State.HEADER_FOUND_CR_LF;

   232         assert sb.length() == 0;

   233         char c = (char)input.get();

   234         if (c == CR) {

   235             state = State.HEADER_FOUND_CR_LF_CR;

   236         } else {

   237             sb.append(c);

   238             state = State.HEADER;

   239         }

   240     }

   241 

   242     private void resumeOrEndHeaders(ByteBuffer input) throws ProtocolException {

   243         assert state == State.HEADER_FOUND_CR_LF_CR;

   244         char c = (char)input.get();

   245         if (c == LF) {

   246             state = State.FINISHED;

   247             headers = ImmutableHeaders.of(privateMap);

   248             privateMap = null;

   249         } else {

   250             throw protocolException("Unexpected \"%s\", after CR LF CR", c);

   251         }

   252     }

   253 

   254     private ProtocolException protocolException(String format, Object... args) {

   255         return new ProtocolException(format(format, args));

   256     }

   257 }