decode() — netty Function Reference

Architecture documentation for the decode() function in Socks4ServerDecoder.java from the netty codebase.

Function java Buffer Allocators calls 1

Entity Profile

Buffer→ Allocators→ decode() — netty Function Reference

Dependency Diagram

graph TD
  1df22ec8_3801_784f_704d_e3f44d44002d["decode()"]
  f3549c11_8ef1_fde3_7585_cf97abbfa145["Socks4ServerDecoder"]
  1df22ec8_3801_784f_704d_e3f44d44002d -->|defined in| f3549c11_8ef1_fde3_7585_cf97abbfa145
  08d49857_8bf5_9ac9_75e1_2f034739ebb2["fail()"]
  1df22ec8_3801_784f_704d_e3f44d44002d -->|calls| 08d49857_8bf5_9ac9_75e1_2f034739ebb2
  style 1df22ec8_3801_784f_704d_e3f44d44002d fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

codec-socks/src/main/java/io/netty/handler/codec/socksx/v4/Socks4ServerDecoder.java lines 61–103

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
        try {
            switch (state()) {
            case START: {
                final int version = in.readUnsignedByte();
                if (version != SocksVersion.SOCKS4a.byteValue()) {
                    throw new DecoderException("unsupported protocol version: " + version);
                }

                type = Socks4CommandType.valueOf(in.readByte());
                dstPort = ByteBufUtil.readUnsignedShortBE(in);
                dstAddr = NetUtil.intToIpAddress(ByteBufUtil.readIntBE(in));
                checkpoint(State.READ_USERID);
            }
            case READ_USERID: {
                userId = readString("userid", in);
                checkpoint(State.READ_DOMAIN);
            }
            case READ_DOMAIN: {
                // Check for Socks4a protocol marker 0.0.0.x
                if (!"0.0.0.0".equals(dstAddr) && dstAddr.startsWith("0.0.0.")) {
                    dstAddr = readString("dstAddr", in);
                }
                out.add(new DefaultSocks4CommandRequest(type, dstAddr, dstPort, userId));
                checkpoint(State.SUCCESS);
            }
            case SUCCESS: {
                int readableBytes = actualReadableBytes();
                if (readableBytes > 0) {
                    out.add(in.readRetainedSlice(readableBytes));
                }
                break;
            }
            case FAILURE: {
                in.skipBytes(actualReadableBytes());
                break;
            }
            }
        } catch (Exception e) {
            fail(out, e);
        }
    }