321 lines
7.1 KiB
Go
321 lines
7.1 KiB
Go
package message
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import (
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"encoding/binary"
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"fmt"
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"strings"
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)
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//RSSP-1 V1.0 铁路信号安全通信协议
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// RsspHead rssp报文头
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type RsspHead struct {
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//报文头-协议交互类别(1Byte)
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Pic byte
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//报文头-报文类别(1Byte)
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Mc byte
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//报文头-源地址(2Byte)
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Sa uint16
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//报文头-目地址(2Byte)
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Da uint16
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}
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func (h *RsspHead) Parse(buf []byte) bool {
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if len(buf) < 6 {
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return false
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}
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h.decode(buf)
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return true
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}
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func (h *RsspHead) Type() RsspType {
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return h.Mc
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}
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func (h *RsspHead) decode(buf []byte) {
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ri := 0
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//报文头
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h.Pic = buf[ri]
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ri++
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h.Mc = buf[ri]
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ri++
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h.Sa = binary.LittleEndian.Uint16(buf[ri : ri+2])
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ri += 2
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h.Da = binary.LittleEndian.Uint16(buf[ri : ri+2])
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ri += 2
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}
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func (h *RsspHead) encode() []byte {
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data := make([]byte, 0, 6)
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//报文头
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data = append(data, h.Pic)
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data = append(data, h.Mc)
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data = binary.LittleEndian.AppendUint16(data, h.Sa)
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data = binary.LittleEndian.AppendUint16(data, h.Da)
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//
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return data
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}
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/////////////////////////////////////////////////
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// RsspPackCrc16Check RSSP报文CRC16校验
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func RsspPackCrc16Check(pack []byte) bool {
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if len(pack) <= 2 { //报文长度不够，校验不通过
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return false
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}
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//
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pack16 := binary.LittleEndian.Uint16(pack[len(pack)-2:])
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crc16 := RsspCrc16(pack[:len(pack)-2])
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//
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return crc16 == pack16
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}
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/////////////////////////////////////////////////
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// RsspRsd 实时安全数据包
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type RsspRsd struct {
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RsspHead
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//安全校验域-序列号(4Byte),可以是一个随时间周期变化的计数器
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Sn uint32
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//安全校验域-安全数据长度(2Byte)
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Sdl uint16
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//安全校验域-安全校验通道1(4Byte)
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Svc1 uint32
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//安全校验域-安全校验通道2(4Byte)
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Svc2 uint32
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//用户数据包-安全应用数据(总字节数480)
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Sad []byte
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//报文尾-CRC16(2Byte)
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Crc16 uint16
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}
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func (r *RsspRsd) Encode() []byte {
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data := make([]byte, 0, 6+14+len(r.Sad)+2)
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//报文头
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data = append(data, r.RsspHead.encode()...)
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//安全校验域
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data = binary.LittleEndian.AppendUint32(data, r.Sn)
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data = binary.LittleEndian.AppendUint16(data, r.Sdl)
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data = binary.LittleEndian.AppendUint32(data, r.Svc1)
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data = binary.LittleEndian.AppendUint32(data, r.Svc2)
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//用户数据包
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data = append(data, r.Sad...)
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//报文尾-CRC16
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r.Crc16 = RsspCrc16(data)
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data = binary.LittleEndian.AppendUint16(data, r.Crc16)
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//
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return data
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}
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func (r *RsspRsd) Decode(buf []byte) error {
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//报文头
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r.RsspHead.decode(buf)
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ri := 6
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//安全校验域
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r.Sn = binary.LittleEndian.Uint32(buf[ri : ri+4])
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ri += 4
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r.Sdl = binary.LittleEndian.Uint16(buf[ri : ri+2])
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ri += 2
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r.Svc1 = binary.LittleEndian.Uint32(buf[ri : ri+4])
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ri += 4
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r.Svc2 = binary.LittleEndian.Uint32(buf[ri : ri+4])
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ri += 4
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//用户数据
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sadLen := int(r.Sdl) - 8
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r.Sad = buf[ri : ri+sadLen]
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ri += sadLen
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//报文尾
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r.Crc16 = binary.LittleEndian.Uint16(buf[ri : ri+2])
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//
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return nil
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}
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///////////////////////////////////////////////////////////////
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// RsspSse 时序校正请求包
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type RsspSse struct {
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RsspHead
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//安全校验域-序列号(4Byte)
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Sn uint32
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//安全校验域-时序校正请求通道1(4Byte)
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SeqEnq1 uint32
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//安全校验域-时序校正请求通道2(4Byte)
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SeqEnq2 uint32
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//报文尾-CRC16(2Byte)
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Crc16 uint16
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}
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func (r *RsspSse) Encode() []byte {
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data := make([]byte, 0, 20)
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//报文头
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data = append(data, r.RsspHead.encode()...)
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//安全校验域
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data = binary.LittleEndian.AppendUint32(data, r.Sn)
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data = binary.LittleEndian.AppendUint32(data, r.SeqEnq1)
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data = binary.LittleEndian.AppendUint32(data, r.SeqEnq2)
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//报文尾-CRC16
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r.Crc16 = RsspCrc16(data)
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data = binary.LittleEndian.AppendUint16(data, r.Crc16)
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return data
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}
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func (r *RsspSse) Decode(buf []byte) error {
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//报文头
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r.RsspHead.decode(buf)
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//安全校验域
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ri := 6
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r.Sn = binary.LittleEndian.Uint32(buf[ri : ri+4])
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ri += 4
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r.SeqEnq1 = binary.LittleEndian.Uint32(buf[ri : ri+4])
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ri += 4
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r.SeqEnq2 = binary.LittleEndian.Uint32(buf[ri : ri+4])
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ri += 4
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//报文尾
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r.Crc16 = binary.LittleEndian.Uint16(buf[ri : ri+2])
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//
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return nil
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}
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/////////////////////////////////////////////////////////
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// RsspSsr 时序校正应答包，用于回应SSE
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type RsspSsr struct {
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RsspHead
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//安全校验域-应答方的序列号(4Byte)
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SrSn uint32
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//安全校验域-请求方的序列号(4Byte)
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SeSn uint32
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//安全校验域-时序初始化通道1(4Byte)
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Tic1 uint32
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//安全校验域-时序初始化通道2(4Byte)
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Tic2 uint32
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//安全校验域-数据版本号(1Byte)
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Dvn byte
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//报文尾-CRC16(2Byte)
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Crc16 uint16
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}
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func (r *RsspSsr) Encode() []byte {
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data := make([]byte, 0, 25)
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//报文头
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data = append(data, r.RsspHead.encode()...)
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//安全校验域
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data = binary.LittleEndian.AppendUint32(data, r.SrSn)
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data = binary.LittleEndian.AppendUint32(data, r.SeSn)
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data = binary.LittleEndian.AppendUint32(data, r.Tic1)
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data = binary.LittleEndian.AppendUint32(data, r.Tic2)
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data = append(data, r.Dvn)
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//报文尾-CRC16
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r.Crc16 = RsspCrc16(data)
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data = binary.LittleEndian.AppendUint16(data, r.Crc16)
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return data
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}
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func (r *RsspSsr) Decode(buf []byte) error {
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//报文头
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r.RsspHead.decode(buf)
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//安全校验域
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ri := 6
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r.SrSn = binary.LittleEndian.Uint32(buf[ri : ri+4])
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ri += 4
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r.SeSn = binary.LittleEndian.Uint32(buf[ri : ri+4])
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ri += 4
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r.Tic1 = binary.LittleEndian.Uint32(buf[ri : ri+4])
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ri += 4
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r.Tic2 = binary.LittleEndian.Uint32(buf[ri : ri+4])
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ri += 4
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r.Dvn = buf[ri]
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ri += 1
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//报文尾
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r.Crc16 = binary.LittleEndian.Uint16(buf[ri : ri+2])
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//
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return nil
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}
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//////////////////////////////////////////////////////////////
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type RsspCodec interface {
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Encode() []byte
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Decode(buf []byte) error
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}
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type Rssper interface {
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Type() RsspType
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}
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type RsspType = byte
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const ( //报文类型
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RSD_A = RsspType(0x80)
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RSD_B = RsspType(0x81)
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SSE = RsspType(0x90)
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SSR = RsspType(0x91)
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)
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// RsspHeadMcCheck 报文类型检测
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func RsspHeadMcCheck(head *RsspHead) bool {
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switch head.Mc {
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case RSD_A:
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return true
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case RSD_B:
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return true
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case SSR:
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return true
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case SSE:
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return true
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default:
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return false
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}
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}
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type PicType = byte
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const ( //协议交互类别
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PIC_MASTER = PicType(0x01) //主机发送的安全数据
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PIC_SLAVE = PicType(0x02) //备机发送的安全数据
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)
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// RsspHeadPicCheck 协议交互类别检测
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func RsspHeadPicCheck(head *RsspHead) bool {
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switch head.Pic {
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case PIC_MASTER:
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return true
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case PIC_SLAVE:
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return true
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default:
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return false
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}
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}
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// ParseRsspPack 解析已经校验的RSSP数据包
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func ParseRsspPack(ph *RsspHead, pack []byte) Rssper {
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//
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var codec RsspCodec
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switch ph.Mc {
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case RSD_A:
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fallthrough
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case RSD_B:
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codec = &RsspRsd{}
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case SSE:
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codec = &RsspSse{}
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case SSR:
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codec = &RsspSsr{}
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default:
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return nil
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}
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//
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if codec.Decode(pack) == nil {
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return codec.(Rssper)
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}
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return nil
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}
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// PackToString 字节数组转换为16进制字节字符串
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func PackToString(pack []byte) string {
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b := &strings.Builder{}
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first := true
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for _, d := range pack {
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if first {
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b.WriteString(fmt.Sprintf("0x%0X", d))
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first = false
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} else {
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b.WriteString(fmt.Sprintf(",0x%0X", d))
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}
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}
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return b.String()
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}
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////////////////////////////////////////////////////////////////////
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