Ejemplo n.º 1
0
func TestgetRandomDevAddr(t *testing.T) {
	conf := getConfig()

	Convey("Given a Redis database and NetID 010203", t, func() {
		p := NewRedisPool(conf.RedisURL)
		netID := lorawan.NetID{1, 2, 3}

		Convey("When calling getRandomDevAddr many times, it should always return an unique DevAddr", func() {
			log := make(map[lorawan.DevAddr]struct{})
			for i := 0; i < 1000; i++ {
				devAddr, err := getRandomDevAddr(p, netID)
				if err != nil {
					t.Fatal(err)
				}
				if devAddr.NwkID() != netID.NwkID() {
					t.Fatalf("%b must equal %b", devAddr.NwkID(), netID.NwkID())
				}
				if len(log) != i {
					t.Fatalf("%d must equal %d", len(log), i)
				}
				log[devAddr] = struct{}{}
			}
		})
	})
}
Ejemplo n.º 2
0
// getRandomDevAddr returns a random free DevAddr. Note that the 7 MSB will be
// set to the NwkID (based on the configured NetID).
// TODO: handle collission with retry?
func getRandomDevAddr(p *redis.Pool, netID lorawan.NetID) (lorawan.DevAddr, error) {
	var d lorawan.DevAddr
	b := make([]byte, len(d))
	if _, err := rand.Read(b); err != nil {
		return d, fmt.Errorf("could not read from random reader: %s", err)
	}
	copy(d[:], b)
	d[0] = d[0] & 1                    // zero out 7 msb
	d[0] = d[0] ^ (netID.NwkID() << 1) // set 7 msb to NwkID

	c := p.Get()
	defer c.Close()

	key := "node_session_" + d.String()
	val, err := redis.Int(c.Do("EXISTS", key))
	if err != nil {
		return lorawan.DevAddr{}, fmt.Errorf("test DevAddr %s exist error: %s", d, err)
	}
	if val == 1 {
		return lorawan.DevAddr{}, fmt.Errorf("DevAddr %s already exists", d)
	}
	return d, nil
}