decode() — netty Function Reference

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

Function java Buffer Allocators

Entity Profile

Buffer→ Allocators→ decode() — netty Function Reference

Dependency Diagram

graph TD
  7f156ba5_0a17_3c8d_259d_a318222f13f3["decode()"]
  fc217319_ea26_738e_cb17_c96d845bfede["SocksCmdResponseDecoder"]
  7f156ba5_0a17_3c8d_259d_a318222f13f3 -->|defined in| fc217319_ea26_738e_cb17_c96d845bfede
  style 7f156ba5_0a17_3c8d_259d_a318222f13f3 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

codec-socks/src/main/java/io/netty/handler/codec/socks/SocksCmdResponseDecoder.java lines 42–96

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf byteBuf, List<Object> out) throws Exception {
        switch (state()) {
            case CHECK_PROTOCOL_VERSION: {
                if (byteBuf.readByte() != SocksProtocolVersion.SOCKS5.byteValue()) {
                    out.add(SocksCommonUtils.UNKNOWN_SOCKS_RESPONSE);
                    break;
                }
                checkpoint(State.READ_CMD_HEADER);
            }
            case READ_CMD_HEADER: {
                cmdStatus = SocksCmdStatus.valueOf(byteBuf.readByte());
                byteBuf.skipBytes(1); // reserved
                addressType = SocksAddressType.valueOf(byteBuf.readByte());
                checkpoint(State.READ_CMD_ADDRESS);
            }
            case READ_CMD_ADDRESS: {
                switch (addressType) {
                    case IPv4: {
                        String host = NetUtil.intToIpAddress(ByteBufUtil.readIntBE(byteBuf));
                        int port = ByteBufUtil.readUnsignedShortBE(byteBuf);
                        out.add(new SocksCmdResponse(cmdStatus, addressType, host, port));
                        break;
                    }
                    case DOMAIN: {
                        int fieldLength = byteBuf.readByte();
                        String host = byteBuf.readString(fieldLength, CharsetUtil.US_ASCII);
                        int port = ByteBufUtil.readUnsignedShortBE(byteBuf);
                        out.add(new SocksCmdResponse(cmdStatus, addressType, host, port));
                        break;
                    }
                    case IPv6: {
                        byte[] bytes = new byte[16];
                        byteBuf.readBytes(bytes);
                        String host = SocksCommonUtils.ipv6toStr(bytes);
                        int port = ByteBufUtil.readUnsignedShortBE(byteBuf);
                        out.add(new SocksCmdResponse(cmdStatus, addressType, host, port));
                        break;
                    }
                    case UNKNOWN: {
                        out.add(SocksCommonUtils.UNKNOWN_SOCKS_RESPONSE);
                        break;
                    }
                    default: {
                        throw new Error("Unexpected address type: " + addressType);
                    }
                }
                break;
            }
            default: {
                throw new Error("Unexpected response decoder type: " + state());
            }
        }
        ctx.pipeline().remove(this);
    }