generate random ipv4 address in go

generate.go

func randomIPFromRange(cidr string) (net.IP, error) {

GENERATE:

	ip, ipnet, err := net.ParseCIDR(cidr)
	if err != nil {
		return nil, err
	}

	// The number of leading 1s in the mask
	ones, _ := ipnet.Mask.Size()
	quotient := ones / 8
	remainder := ones % 8

	// create random 4-byte byte slice
	r := make([]byte, 4)
	rand.Read(r)

	for i := 0; i <= quotient; i++ {
		if i == quotient {
			shifted := byte(r[i]) >> remainder
			r[i] = ^ipnet.IP[i] & shifted
		} else {
			r[i] = ipnet.IP[i]
		}
	}
	ip = net.IPv4(r[0], r[1], r[2], r[3])

	if ip.Equal(ipnet.IP) /*|| ip.Equal(broadcast) */ {
		// we got unlucky. The host portion of our ipv4 address was
		// either all 0s (the network address) or all 1s (the broadcast address)
		goto GENERATE
	}
	return ip, nil
}