前言

该RPC反对 TCP KCP UNIX 所以咱们要对协定进行设计

https://github.com/dollarkill...

定义握手协定

握手逻辑:

1. 建设链接 通过非对称加密 传输 aes 密钥给服务端 (携带token)
2. 服务端 验证 token 并记录 aes 密钥 前面与客户端交互 都采纳对称加密

type Handshake struct {    Key   []byte  // aes 加密 KEY    Token []byte  // AUTH 校验应用    Error []byte  // 谬误填充}

编码

func EncodeHandshake(key, token, err []byte) []byte {    buf := make([]byte, 13+len(key)+len(token)+len(err))    buf[0] = LightHandshakeSt    binary.LittleEndian.PutUint32(buf[1:5], uint32(len(key)))    binary.LittleEndian.PutUint32(buf[5:9], uint32(len(token)))    binary.LittleEndian.PutUint32(buf[9:13], uint32(len(err)))    st := 13    endI := st + len(key)    copy(buf[st:endI], key)    st = endI    endI = st + len(token)    copy(buf[st:endI], token)    st = endI    endI = st + len(err)    copy(buf[st:endI], err)    return buf}

解码

func (h *Handshake) Handshake(r io.Reader) error {    headerByte := make([]byte, 13)    // 读取标记位    _, err := io.ReadFull(r, headerByte[:1])    if err != nil {        return err    }    if headerByte[0] != LightHandshakeSt {        return errors.New("NO Light Handshake")    }    // 读取剩下的    _, err = io.ReadFull(r, headerByte[1:])    if err != nil {        return err    }    // 解析头    keySize := binary.LittleEndian.Uint32(headerByte[1:5])    tokenSize := binary.LittleEndian.Uint32(headerByte[5:9])    errorSize := binary.LittleEndian.Uint32(headerByte[9:13])    bodyData := make([]byte, keySize+tokenSize+errorSize)    _, err = io.ReadFull(r, bodyData)    if err != nil {        return err    }    var st uint32 = 0    endIdx := keySize    key := make([]byte, keySize)    copy(key, bodyData[st:endIdx])    h.Key = key    st = endIdx    endIdx = st + tokenSize    token := make([]byte, tokenSize)    copy(token, bodyData[st:endIdx])    h.Token = token    st = endIdx    endIdx = st + errorSize    errStr := make([]byte, errorSize)    copy(errStr, bodyData[st:endIdx])    h.Error = errStr    return nil}

定义传输协定

/**    协定设计    起始符 :  版本号 :  crc32校验 :   magicNumberSize:    serverNameSize :   serverMethodSize :  metaDataSize : payloadSize:  respType :   compressorType :    serializationType :    magicNumber :  serverName :   serverMethod :  metaData :  payload        0x05  :  0x01  :     4     :        4         :         4         :         4          :       4       :      4     :      1    :          1       :           1          :        xxx     :       xxx   :        xxx     :    xxx    :    xxx*/type Message struct {    Header        *Header    MagicNumber   string    ServiceName   string    ServiceMethod string    MetaData      []byte    Payload       []byte}type Header struct {    St                byte    Version           byte    Crc32             uint32    MagicNumberSize   uint32    ServerNameSize    uint32    ServerMethodSize  uint32    MetaDataSize      uint32    PayloadSize       uint32    RespType          byte    CompressorType    byte    SerializationType byte}

编码

// EncodeMessage 根底编码func EncodeMessage(magicStr string, server, method, metaData []byte, respType, compressorType, serializationType byte, payload []byte) (magic string, data []byte, err error) {    var magicNumber = []byte(magicStr)    if magicStr == "" {        magicNumber = []byte(xid.New().String())    }    bufSize := HeadSize + len(server) + len(method) + len(metaData) + len(payload) + len(magicNumber)    buf := make([]byte, bufSize)    buf[0] = LightSt    buf[1] = byte(V1)    binary.LittleEndian.PutUint32(buf[6:10], uint32(len(magicNumber)))    binary.LittleEndian.PutUint32(buf[10:14], uint32(len(server)))    binary.LittleEndian.PutUint32(buf[14:18], uint32(len(method)))    binary.LittleEndian.PutUint32(buf[18:22], uint32(len(metaData)))    binary.LittleEndian.PutUint32(buf[22:26], uint32(len(payload)))    buf[26] = respType    buf[27] = compressorType    buf[28] = serializationType    st := HeadSize    endI := st + len(magicNumber)    copy(buf[st:endI], magicNumber)    st = endI    endI = st + len(server)    copy(buf[st:endI], server)    st = endI    endI = st + len(method)    copy(buf[st:endI], method)    st = endI    endI = st + len(metaData)    copy(buf[st:endI], metaData)    st = endI    endI = st + len(payload)    copy(buf[st:endI], payload)    if Crc32 {        u := crc32.ChecksumIEEE(buf[6:])        binary.LittleEndian.PutUint32(buf[2:6], u)    }    return string(magicNumber), buf, nil}

解码

func (m *Protocol) IODecode(r io.Reader) (*Message, error) {    headerByte := make([]byte, HeadSize)    // 读取标记位    _, err := io.ReadFull(r, headerByte[:1])    if err != nil {        return nil, err    }    if headerByte[0] != LightSt {        log.Println(headerByte)        return nil, errors.New("NO Light")    }    // 读取剩下的    _, err = io.ReadFull(r, headerByte[1:])    if err != nil {        return nil, err    }    // 解析 header    header, err := DecodeHeader(headerByte)    if err != nil {        return nil, err    }    bodyLen := header.MagicNumberSize + header.ServerNameSize + header.ServerMethodSize + header.MetaDataSize + header.PayloadSize    bodyData := make([]byte, bodyLen)    _, err = io.ReadFull(r, bodyData)    if err != nil {        return nil, err    }    msg, err := DecodeMessageV2(bodyData, header, 0)    if err != nil {        return nil, err    }    return msg, nil}func DecodeHeader(data []byte) (*Header, error) {    var header Header    header.St = data[0]    header.Version = data[1]    header.Crc32 = binary.LittleEndian.Uint32(data[2:6])    if Crc32 {        u := crc32.ChecksumIEEE(data[6:])        if header.Crc32 != u {            return nil, errors.New("CRC Calibration")        }    }    header.MagicNumberSize = binary.LittleEndian.Uint32(data[6:10])    header.ServerNameSize = binary.LittleEndian.Uint32(data[10:14])    header.ServerMethodSize = binary.LittleEndian.Uint32(data[14:18])    header.MetaDataSize = binary.LittleEndian.Uint32(data[18:22])    header.PayloadSize = binary.LittleEndian.Uint32(data[22:26])    header.RespType = data[26]    header.CompressorType = data[27]    header.SerializationType = data[28]    return &header, nil}// DecodeMessage 残缺Decodefunc DecodeMessage(data []byte) (*Message, error) {    header, err := DecodeHeader(data)    if err != nil {        return nil, err    }    return DecodeMessageV2(data, header, HeadSize)}func DecodeMessageV2(data []byte, header *Header, headSize uint32) (*Message, error) {    var result Message    result.Header = header    var st uint32 = headSize    endI := st + header.MagicNumberSize    les := endI - st    magicNumber := make([]byte, les)    copy(magicNumber, data[st:endI])    result.MagicNumber = string(magicNumber)    st = endI    endI = st + header.ServerNameSize    les = endI - st    serverName := make([]byte, les)    copy(serverName, data[st:endI])    result.ServiceName = string(serverName)    st = endI    endI = st + header.ServerMethodSize    les = endI - st    serverMethodSize := make([]byte, les)    copy(serverMethodSize, data[st:endI])    result.ServiceMethod = string(serverMethodSize)    st = endI    endI = st + header.MetaDataSize    les = endI - st    metaDataSize := make([]byte, les)    copy(metaDataSize, data[st:endI])    result.MetaData = metaDataSize    st = endI    endI = st + header.PayloadSize    les = endI - st    payloadSize := make([]byte, les)    copy(payloadSize, data[st:endI])    result.Payload = payloadSize    return &result, nil}