SocketCan in Golang

socketcan-golang.go

package main

import "fmt"
import "golang.org/x/sys/unix"
import "net"
import "log"
import "encoding/binary"
import "flag"

// CANMsg almacena un mensaje de la red CAN
type CANMsg struct {
    id  uint32
    dlc uint8
    ext uint8
    rtr uint8
    //padding uint8
    //res0 uint8
    //res1 uint8
    data []byte
}

func byteArrayToCANMsg(array []byte, canmsg *CANMsg) {
    canmsg.id = binary.LittleEndian.Uint32(array[0:4])

    if canmsg.id & unix.CAN_RTR_FLAG != 0 {
        canmsg.rtr = 1
    }
    if canmsg.id&unix.CAN_EFF_FLAG != 0 {
        canmsg.ext = 1
        canmsg.id = canmsg.id & unix.CAN_EFF_MASK
    } else {
        canmsg.ext = 0
        canmsg.id = canmsg.id & unix.CAN_SFF_MASK
    }

    canmsg.dlc = array[4]
    canmsg.data = array[8 : 8+array[4]]
}

func main() {
    canIface := flag.String("canif", "can0", "The CAN interface")

    flag.Parse()
    iface, err := net.InterfaceByName(*canIface)
    if err != nil {
        log.Fatal(err)
    }

    fd, _ := unix.Socket(unix.AF_CAN, unix.SOCK_RAW, unix.CAN_RAW)
    addr := &unix.SockaddrCAN{Ifindex: iface.Index}
    unix.Bind(fd, addr)
    frame := make([]byte, 16)
    // frame[0:3]: ID (LSB primero)
    // frame[4]: largo
    // frame[5]: padding
    // frame[6:7]: reserved
    // frame[8:15]: data

	canmsg := new(CANMsg)

    fmt.Println("Hola")
    for {
        unix.Read(fd, frame)
        byteArrayToCANMsg(frame, canmsg)
        fmt.Printf("%+v\n", *canmsg)
    }
}