initial attempt

.gitignore

@@ -12,4 +12,4 @@
 *.out
 
 # Dependency directories (remove the comment below to include it)
-# vendor/
+# vendor/

go.mod

@@ -0,0 +1,5 @@
+module github.com/monoxane/nk
+
+go 1.19
+
+require github.com/pkg/errors v0.9.1 

go.sum

@@ -0,0 +1,2 @@
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=

model.go

@@ -0,0 +1,46 @@
+package nk
+
+import "net"
+
+// Aliases
+
+type Model = string
+type TBusAddress = uint8
+type Destination = uint16
+type Source = uint16
+type Level = uint32
+
+// Structs
+
+type Router struct {
+	IP           string
+	Address      TBusAddress
+	Destinations uint16
+	Sources      uint16
+	Level        Level
+	Conn         net.Conn
+}
+
+type TBusPacketPayload struct {
+	NK2Header   uint32
+	RTRAddress  TBusAddress
+	UNKNB       uint16
+	Destination Destination
+	Source      Source
+	LevelMask   Level
+	UNKNC       uint8
+}
+
+type TBusPacket struct {
+	HeaderA uint32
+	HeaderB uint16
+	Payload TBusPacketPayload
+	CRC     uint16
+}
+
+type CrosspointRequest struct {
+	Source      Source
+	Destination Destination
+	Level       Level
+	Address     TBusAddress
+}

nk.go

@@ -0,0 +1,127 @@
+package nk
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"log"
+	"net"
+	"strings"
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+const (
+	LVL_MDVID uint32 = 1
+
+	MODEL_NK_3G72      Model = "NK-3G72"
+	MODEL_NK_3G64      Model = "NK-3G64"
+	MODEL_NK_3G34      Model = "NK-3G34"
+	MODEL_NK_3G16      Model = "NK-3G16"
+	MODEL_NK_3G16_RCP  Model = "NK-3G16-RCP"
+	MODEL_NK_3G164     Model = "NK-3G164"
+	MODEL_NK_3G164_RCP Model = "NK-3G164-RCP"
+)
+
+func New(IP string, RTRAddress uint8, model Model) *Router {
+	rtr := &Router{
+		IP:      IP,
+		Address: RTRAddress,
+	}
+
+	switch model {
+	case MODEL_NK_3G72:
+		rtr.Destinations = 72
+		rtr.Sources = 72
+		rtr.Level = LVL_MDVID
+	case MODEL_NK_3G64:
+		rtr.Destinations = 64
+		rtr.Sources = 64
+		rtr.Level = LVL_MDVID
+	case MODEL_NK_3G34:
+		rtr.Destinations = 34
+		rtr.Sources = 34
+		rtr.Level = LVL_MDVID
+	case MODEL_NK_3G16, MODEL_NK_3G16_RCP:
+		rtr.Destinations = 16
+		rtr.Sources = 16
+		rtr.Level = LVL_MDVID
+	case MODEL_NK_3G164, MODEL_NK_3G164_RCP:
+		rtr.Destinations = 4
+		rtr.Sources = 16
+		rtr.Level = LVL_MDVID
+	}
+
+	return rtr
+}
+
+func (rtr *Router) Connect() {
+	conn, err := net.Dial("tcp", rtr.IP+":5000")
+	if err != nil {
+		log.Fatalln(err)
+	}
+	rtr.Conn = conn
+	defer rtr.Conn.Close()
+
+	serverReader := bufio.NewReader(rtr.Conn)
+
+	openConnStr := strings.TrimSpace("PHEONIX-DB")
+	if _, err = rtr.Conn.Write([]byte(openConnStr + "\n")); err != nil {
+		log.Printf("failed to send the client request: %v\n", err)
+	}
+
+	go func() {
+		for range time.Tick(10 * time.Second) {
+			rtr.Conn.Write([]byte("HI"))
+		}
+	}()
+
+	for {
+
+		serverResponse, err := serverReader.ReadString('\n')
+		switch err {
+		case nil:
+			log.Println(strings.TrimSpace(serverResponse))
+		case io.EOF:
+			log.Println("server closed the connection")
+			return
+		default:
+			log.Printf("server error: %v\n", err)
+			return
+		}
+	}
+}
+
+func (rtr *Router) SetCrosspoint(level Level, destination Destination, source Source) error {
+	if level != rtr.Level {
+		return fmt.Errorf("requested level is not possible on this router")
+	}
+
+	if destination <= 0 || destination > rtr.Destinations {
+		return fmt.Errorf("requested destination is outside the range available on this router model")
+	}
+
+	if source <= 0 || source > rtr.Sources {
+		return fmt.Errorf("requested source is outside the range available on this router model")
+	}
+
+	xptreq := CrosspointRequest{
+		Source:      source,
+		Destination: destination,
+		Level:       level,
+		Address:     rtr.Address,
+	}
+
+	packet, err := xptreq.GeneratePacket()
+	if err != nil {
+		return errors.Wrap(err, "unable to generate crosspoint route request")
+	}
+
+	_, err = rtr.Conn.Write(packet)
+	if err != nil {
+		return errors.Wrap(err, "unable to send route request to router")
+	}
+
+	return nil
+}

routing.go

@@ -0,0 +1,44 @@
+package nk
+
+import (
+	"bytes"
+	"encoding/binary"
+	"log"
+)
+
+// GenerateXPTRequest Just returns payload to send to router to close xpt
+func (xpt *CrosspointRequest) GeneratePacket() ([]byte, error) {
+	destination := xpt.Destination - 1
+	source := xpt.Source - 1
+
+	payload := TBusPacketPayload{
+		NK2Header:   0x4e4b3200,
+		RTRAddress:  xpt.Address,
+		UNKNB:       0x0409,
+		Destination: destination,
+		Source:      source,
+		LevelMask:   xpt.Level,
+		UNKNC:       0x00,
+	}
+
+	payloadBuffer := new(bytes.Buffer)
+	err := binary.Write(payloadBuffer, binary.BigEndian, payload)
+	if err != nil {
+		log.Println("TBusPacketPayload binary.Write failed:", err)
+	}
+
+	packet := TBusPacket{
+		HeaderA: 0x50415332,
+		HeaderB: 0x0012,
+		Payload: payload,
+		CRC:     crc16(payloadBuffer.Bytes()),
+	}
+
+	packetBuffer := new(bytes.Buffer)
+	err = binary.Write(packetBuffer, binary.BigEndian, packet)
+	if err != nil {
+		log.Println("TBustPacket binary.Write failed:", err)
+	}
+
+	return packetBuffer.Bytes(), nil
+}

utils.go

@@ -0,0 +1,22 @@
+package nk
+
+// Simple 2 byte CRC for XPT payload
+func crc16(buffer []byte) uint16 {
+	var crc = 0xFFFF
+	var odd = 0x0000
+
+	for i := 0; i < len(buffer); i++ {
+		crc = crc ^ int(buffer[i])
+
+		for j := 0; j < 8; j++ {
+			odd = crc & 0x0001
+			crc = crc >> 1
+			if odd == 1 {
+				crc = crc ^ 0xA001
+			}
+		}
+	}
+
+	crc = ((crc & 0xFF) << 8) | ((crc & 0xFF00) >> 8)
+	return uint16(crc)
+}