func newAllocatedMap(network *net.IPNet) *allocatedMap {
firstIP, lastIP := netutils.NetworkRange(network)
begin := big.NewInt(0).Add(ipToBigInt(firstIP), big.NewInt(1))
end := big.NewInt(0).Sub(ipToBigInt(lastIP), big.NewInt(1))
return &allocatedMap{
p: make(map[string]struct{}),
begin: begin,
end: end,
last: big.NewInt(0).Sub(begin, big.NewInt(1)), // so first allocated will be begin
}
}
// RegisterSubnet registers network in global allocator with bounds
// defined by subnet. If you want to use network range you must call
// this method before first RequestIP, otherwise full network range will be used
func (a *IPAllocator) RegisterSubnet(network *net.IPNet, subnet *net.IPNet) error {
a.mutex.Lock()
defer a.mutex.Unlock()
key := network.String()
if _, ok := a.allocatedIPs[key]; ok {
return ErrNetworkAlreadyRegistered
}
// Check that subnet is within network
beginIP, endIP := netutils.NetworkRange(subnet)
if !(network.Contains(beginIP) && network.Contains(endIP)) {
return ErrBadSubnet
}
n := newAllocatedMap(subnet)
a.allocatedIPs[key] = n
return nil
}