1 /*

     2  * Copyright (c) 2015, 2016, 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 java.net.http;

    27 

    28 import java.io.IOException;

    29 import java.nio.ByteBuffer;

    30 

    31 /**

    32  * When sending a frame, the length field must be set in sub-class

    33  * by calling computeLength()

    34  */

    35 abstract class Http2Frame {

    36 

    37     int length = -1;

    38     int type;

    39     int streamid;

    40     int flags;

    41 

    42     // called when reading in only

    43     void initCommon(int length, int type, int streamid, int flags) {

    44         this.length = length;

    45         this.type = type;

    46         this.streamid = streamid;

    47         this.flags = flags;

    48     }

    49 

    50     public int length() {

    51         return length;

    52     }

    53 

    54     public int type() {

    55         return type;

    56     }

    57 

    58     public int streamid() {

    59         return streamid;

    60     }

    61 

    62     public void setFlag(int flag) {

    63         flags |= flag;

    64     }

    65 

    66     public void setFlags(int flags) {

    67         this.flags = flags;

    68     }

    69 

    70     public int getFlags() {

    71         return flags;

    72     }

    73 

    74     public boolean getFlag(int flag) {

    75         return (flags & flag) != 0;

    76     }

    77 

    78     public void clearFlag(int flag) {

    79         flags &= 0xffffffff ^ flag;

    80     }

    81 

    82     public void streamid(int streamid) {

    83         this.streamid = streamid;

    84     }

    85 

    86     abstract void readIncomingImpl(ByteBufferConsumer bc) throws IOException;

    87 

    88     /**

    89      * assume given array contains at least one complete frame.

    90      */

    91     static Http2Frame readIncoming(ByteBufferConsumer bc) throws IOException {

    92         int x = bc.getInt();

    93         int length = x >> 8;

    94         int type = x & 0xff;

    95         int flags = bc.getByte();

    96         int streamid = bc.getInt();

    97         Http2Frame f = null;

    98         switch (type) {

    99           case DataFrame.TYPE:

   100             f = new DataFrame();

   101             break;

   102           case HeadersFrame.TYPE:

   103             f = new HeadersFrame();

   104             break;

   105           case ContinuationFrame.TYPE:

   106             f = new ContinuationFrame();

   107             break;

   108           case ResetFrame.TYPE:

   109             f = new ResetFrame();

   110             break;

   111           case PriorityFrame.TYPE:

   112             f = new PriorityFrame();

   113             break;

   114           case SettingsFrame.TYPE:

   115             f = new SettingsFrame();

   116             break;

   117           case GoAwayFrame.TYPE:

   118             f = new GoAwayFrame();

   119             break;

   120           case PingFrame.TYPE:

   121             f = new PingFrame();

   122             break;

   123           case PushPromiseFrame.TYPE:

   124             f = new PushPromiseFrame();

   125             break;

   126           case WindowUpdateFrame.TYPE:

   127             f = new WindowUpdateFrame();

   128             break;

   129           default:

   130             String msg = Integer.toString(type);

   131             throw new IOException("unknown frame type " + msg);

   132         }

   133         f.initCommon(length, type, streamid, flags);

   134         f.readIncomingImpl(bc);

   135         return f;

   136     }

   137 

   138     public String typeAsString() {

   139         return asString(this.type);

   140     }

   141 

   142     public static String asString(int type) {

   143         switch (type) {

   144           case DataFrame.TYPE:

   145             return "DATA";

   146           case HeadersFrame.TYPE:

   147             return "HEADERS";

   148           case ContinuationFrame.TYPE:

   149             return "CONTINUATION";

   150           case ResetFrame.TYPE:

   151             return "RESET";

   152           case PriorityFrame.TYPE:

   153             return "PRIORITY";

   154           case SettingsFrame.TYPE:

   155             return "SETTINGS";

   156           case GoAwayFrame.TYPE:

   157             return "GOAWAY";

   158           case PingFrame.TYPE:

   159             return "PING";

   160           case PushPromiseFrame.TYPE:

   161             return "PUSH_PROMISE";

   162           case WindowUpdateFrame.TYPE:

   163             return "WINDOW_UPDATE";

   164           default:

   165             return "UNKNOWN";

   166         }

   167     }

   168 

   169     @Override

   170     public String toString() {

   171         StringBuilder sb = new StringBuilder();

   172         sb.append(typeAsString())

   173                 .append(": length=")

   174                 .append(Integer.toString(length))

   175                 .append(", streamid=")

   176                 .append(streamid)

   177                 .append(", flags=");

   178 

   179         int f = flags;

   180         int i = 0;

   181         if (f == 0) {

   182             sb.append("0 ");

   183         } else {

   184             while (f != 0) {

   185                 if ((f & 1) == 1) {

   186                     sb.append(flagAsString(1 << i))

   187                       .append(' ');

   188                 }

   189                 f = f >> 1;

   190                 i++;

   191             }

   192         }

   193         return sb.toString();

   194     }

   195 

   196     // Override

   197     String flagAsString(int f) {

   198         return "unknown";

   199     }

   200 

   201     abstract void computeLength();

   202 

   203     void writeOutgoing(ByteBufferGenerator bg) {

   204         if (length == -1) {

   205             throw new InternalError("Length not set on outgoing frame");

   206         }

   207         ByteBuffer buf = bg.getBuffer(9);

   208         int x = (length << 8) + type;

   209         buf.putInt(x);

   210         buf.put((byte)flags);

   211         buf.putInt(streamid);

   212     }

   213 }