91 lines
3.2 KiB
Java
Executable File
91 lines
3.2 KiB
Java
Executable File
/*
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* Copyright 2012 The Netty Project
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*
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* The Netty Project licenses this file to you under the Apache License,
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* version 2.0 (the "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*/
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package io.netty.handler.codec.socksx.v4;
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import io.netty.buffer.ByteBuf;
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import io.netty.channel.ChannelHandlerContext;
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import io.netty.handler.codec.DecoderException;
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import io.netty.handler.codec.DecoderResult;
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import io.netty.handler.codec.ReplayingDecoder;
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import io.netty.handler.codec.socksx.v4.Socks4ClientDecoder.State;
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import io.netty.util.NetUtil;
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/**
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* Decodes a single {@link Socks4CommandResponse} from the inbound {@link ByteBuf}s.
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* On successful decode, this decoder will forward the received data to the next handler, so that
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* other handler can remove this decoder later. On failed decode, this decoder will discard the
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* received data, so that other handler closes the connection later.
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*/
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public class Socks4ClientDecoder extends ReplayingDecoder<State> {
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enum State {
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START,
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SUCCESS,
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FAILURE
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}
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public Socks4ClientDecoder() {
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super(State.START);
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setSingleDecode(true);
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}
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@Override
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protected void decode(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
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try {
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switch (state()) {
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case START: {
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final int version = in.readUnsignedByte();
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if (version != 0) {
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throw new DecoderException("unsupported reply version: " + version + " (expected: 0)");
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}
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final Socks4CommandStatus status = Socks4CommandStatus.valueOf(in.readByte());
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final int dstPort = in.readUnsignedShort();
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final String dstAddr = NetUtil.intToIpAddress(in.readInt());
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ctx.fireChannelRead(new DefaultSocks4CommandResponse(status, dstAddr, dstPort));
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checkpoint(State.SUCCESS);
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}
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case SUCCESS: {
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int readableBytes = actualReadableBytes();
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if (readableBytes > 0) {
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ctx.fireChannelRead(in.readRetainedSlice(readableBytes));
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}
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break;
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}
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case FAILURE: {
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in.skipBytes(actualReadableBytes());
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break;
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}
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}
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} catch (Exception e) {
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fail(ctx, e);
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}
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}
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private void fail(ChannelHandlerContext ctx, Exception cause) {
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if (!(cause instanceof DecoderException)) {
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cause = new DecoderException(cause);
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}
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Socks4CommandResponse m = new DefaultSocks4CommandResponse(Socks4CommandStatus.REJECTED_OR_FAILED);
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m.setDecoderResult(DecoderResult.failure(cause));
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ctx.fireChannelRead(m);
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checkpoint(State.FAILURE);
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}
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}
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