|
|
|
// Package rings provides logic to work with the four rings
|
|
|
|
// of a cluster
|
|
|
|
package rings
|
|
|
|
|
|
|
|
import (
|
|
|
|
"net/netip"
|
|
|
|
"syscall"
|
|
|
|
|
|
|
|
"darvaza.org/core"
|
|
|
|
)
|
|
|
|
|
|
|
|
const (
|
|
|
|
// RegionMax indicates the highest number that can be used for a [RegionID].
|
|
|
|
RegionMax = (1 << 4) - 1
|
|
|
|
// ZoneMax indicates the highest number that can be used for a [ZoneID].
|
|
|
|
ZoneMax = (1 << 4) - 1
|
|
|
|
// NodeMax indicates the highest number that can be used for a [NodeID].
|
|
|
|
NodeMax = (1 << 12) - 1
|
|
|
|
// NodeZeroMax indicates the highest number that can be used for a [NodeID]
|
|
|
|
// when its a gateway connected to Ring 0 (backbone).
|
|
|
|
NodeZeroMax = (1 << 8) - 1
|
|
|
|
|
|
|
|
// RingOneBits indicates the size of the prefix on the ring 1 (lan) network.
|
|
|
|
RingOneBits = 20
|
|
|
|
)
|
|
|
|
|
|
|
|
// RegionID is the identifier of a region, valid between 1 and [RegionMax].
|
|
|
|
type RegionID int
|
|
|
|
|
|
|
|
// Valid tells a [RegionID] is within the valid range.
|
|
|
|
func (n RegionID) Valid() bool { return n > 0 && n <= RegionMax }
|
|
|
|
|
|
|
|
// ZoneID is the identifier of a zone within a region, valid between 1 and [ZoneMax].
|
|
|
|
type ZoneID int
|
|
|
|
|
|
|
|
// Valid tells a [ZoneID] is within the valid range.
|
|
|
|
func (n ZoneID) Valid() bool { return n > 0 && n <= ZoneMax }
|
|
|
|
|
|
|
|
// NodeID is the identifier of a machine within a zone of a region, valid between
|
|
|
|
// 1 and [NodeMax], but between 1 and [NodeZeroMax] if it will be a zone gateway.
|
|
|
|
type NodeID int
|
|
|
|
|
|
|
|
// Valid tells a [NodeID] is within the valid range.
|
|
|
|
func (n NodeID) Valid() bool { return n > 0 && n <= NodeMax }
|
|
|
|
|
|
|
|
// ValidZero tells a [NodeID] is within the valid range for a gateway.
|
|
|
|
func (n NodeID) ValidZero() bool { return n > 0 && n <= NodeZeroMax }
|
|
|
|
|
|
|
|
// ErrOutOfRange is an error indicating the value of a field
|
|
|
|
// is out of range.
|
|
|
|
func ErrOutOfRange[T ~int | ~uint32](value T, field string) error {
|
|
|
|
return core.Wrap(syscall.EINVAL, "%s out of range (%v)", field, value)
|
|
|
|
}
|
|
|
|
|
|
|
|
// 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 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)
|
|
|
|
}
|