func NewIPAllocator(conf *IPAMConfig, store backend.Store) (*IPAllocator, error) {
var (
start net.IP
end net.IP
err error
)
start, end, err = networkRange((*net.IPNet)(&conf.Subnet))
if err != nil {
return nil, err
}
// skip the .0 address
start = ip.NextIP(start)
if conf.RangeStart != nil {
if err := validateRangeIP(conf.RangeStart, (*net.IPNet)(&conf.Subnet)); err != nil {
return nil, err
}
start = conf.RangeStart
}
if conf.RangeEnd != nil {
if err := validateRangeIP(conf.RangeEnd, (*net.IPNet)(&conf.Subnet)); err != nil {
return nil, err
}
// RangeEnd is inclusive
end = ip.NextIP(conf.RangeEnd)
}
return &IPAllocator{start, end, conf, store}, nil
}
// Returns newly allocated IP along with its config
func (a *IPAllocator) Get(id string) (*types.IPConfig, error) {
a.store.Lock()
defer a.store.Unlock()
gw := a.conf.Gateway
if gw == nil {
gw = ip.NextIP(a.conf.Subnet.IP)
}
var requestedIP net.IP
if a.conf.Args != nil {
requestedIP = a.conf.Args.IP
}
if requestedIP != nil {
if gw != nil && gw.Equal(a.conf.Args.IP) {
return nil, fmt.Errorf("requested IP must differ gateway IP")
}
subnet := net.IPNet{
IP: a.conf.Subnet.IP,
Mask: a.conf.Subnet.Mask,
}
err := validateRangeIP(requestedIP, &subnet)
if err != nil {
return nil, err
}
reserved, err := a.store.Reserve(id, requestedIP)
if err != nil {
return nil, err
}
if reserved {
return &types.IPConfig{
IP: net.IPNet{requestedIP, a.conf.Subnet.Mask},
Gateway: gw,
Routes: a.conf.Routes,
}, nil
}
return nil, fmt.Errorf("requested IP address %q is not available in network: %s", requestedIP, a.conf.Name)
}
for cur := a.start; !cur.Equal(a.end); cur = ip.NextIP(cur) {
// don't allocate gateway IP
if gw != nil && cur.Equal(gw) {
continue
}
reserved, err := a.store.Reserve(id, cur)
if err != nil {
return nil, err
}
if reserved {
return &types.IPConfig{
IP: net.IPNet{cur, a.conf.Subnet.Mask},
Gateway: gw,
Routes: a.conf.Routes,
}, nil
}
}
return nil, fmt.Errorf("no IP addresses available in network: %s", a.conf.Name)
}
func calcGatewayIP(ipn *net.IPNet) net.IP {
nid := ipn.IP.Mask(ipn.Mask)
return ip.NextIP(nid)
}