C OID handling in Go

gistfile1.go

type OID []uint32

// Create a new OID
func NewOID(num ...uint32) OID {
    return num
}

// Create an OID from the C representation
func NewOIDFromCArray(coid *C.oid, oid_length C.int) (OID, error) {
    // See http://stackoverflow.com/questions/14826319/go-cgo-how-do-you-use-a-c-array-passed-as-a-pointer
    var (
        o      OID
        err    error
        buf    *bytes.Reader
        result = make([]uint32, int(oid_length))
        size   = C.int(unsafe.Sizeof(*coid))
        b      = C.GoBytes(unsafe.Pointer(coid), size*oid_length)
    )

    // Read a single uint32 from the buffer
    // Each OID is 4 little-endian, with 4 bytes of padding between them
    for i := 0; i < int(size*oid_length); i += 8 {
        var out uint32
        buf = bytes.NewReader(b[i : i+8])
        if err = binary.Read(buf, binary.LittleEndian, &out); err != nil {
            return o, BadOID
        }

        // Append the number to the result
        result[i/8] = out
    }

    return NewOID(result...), nil
}