package rings import "net/netip" // RingZeroPrefix represents the backbone that connects gateways // of the different Ring 1 networks. // // The ring 0 network corresponds to what would be ring 2 for region_id 0. // 10.0.0.0-10.0.255.255 func RingZeroPrefix(region RegionID, zone ZoneID) (cidr netip.Prefix, err error) { switch { case !region.Valid(): err = ErrOutOfRange(region, "region") case !zone.Valid(): err = ErrOutOfRange(zone, "zone") default: addr := unsafeRingZeroAddress(region, zone, 0) cidr = netip.PrefixFrom(addr, RingZeroBits) } return cidr, err } // RingZeroAddress returns a Ring 0 address for a particular node. // // A ring 0 address looks like 10.0.(region_id << 4 + zone_id).(node_id)/20 func RingZeroAddress(region RegionID, zone ZoneID, node NodeID) (addr netip.Addr, err error) { switch { case !region.Valid(): err = ErrOutOfRange(region, "region") case !zone.Valid(): err = ErrOutOfRange(zone, "zone") case !node.ValidZero(): err = ErrOutOfRange(node, "node") default: addr = unsafeRingZeroAddress(region, zone, node) } return addr, err } // RingOnePrefix represents a (virtual) local network of a zone. // // Ring 1 is `10.(region_id).(zone_id << 4).(node_id)/20` network // grouped under what would be Ring 2 for region_id 0. // There are 12 bits worth of nodes but nodes under 255 are special // as they also get a slot on Ring 0. func RingOnePrefix(region RegionID, zone ZoneID) (cidr netip.Prefix, err error) { switch { case !region.Valid(): err = ErrOutOfRange(region, "region") case !zone.Valid(): err = ErrOutOfRange(zone, "zone") default: addr := unsafeRingOneAddress(region, zone, 0) cidr = netip.PrefixFrom(addr, RingOneBits) } return cidr, err } // RingOneAddress returns a Ring 1 address for a particular node. // // A ring 1 address is `10.(region_id).(zone_id << 4).(node_id)/20` // but the node_id can take up to 12 bits. func RingOneAddress(region RegionID, zone ZoneID, node NodeID) (addr netip.Addr, err error) { switch { case !region.Valid(): err = ErrOutOfRange(region, "region") case !zone.Valid(): err = ErrOutOfRange(zone, "zone") case !node.Valid(): err = ErrOutOfRange(node, "node") default: addr = unsafeRingOneAddress(region, zone, node) } return addr, err } func unsafeRingZeroAddress(region RegionID, zone ZoneID, node NodeID) netip.Addr { r := uint(region) z := uint(zone) n := uint(node) return AddrFrom4(10, 0, r<<4+z, n) } func unsafeRingOneAddress(region RegionID, zone ZoneID, node NodeID) netip.Addr { r := uint(region) z := uint(zone) n := uint(node) n1 := n >> 8 n0 := n >> 0 return AddrFrom4(10, r, z<<4+n1, n0) }