all: sync with master

internal/dhcpsvc/interface.go

@@ -0,0 +1,66 @@
+package dhcpsvc
+
+import (
+	"fmt"
+	"slices"
+	"time"
+)
+
+// netInterface is a common part of any network interface within the DHCP
+// server.
+//
+// TODO(e.burkov):  Add other methods as [DHCPServer] evolves.
+type netInterface struct {
+	// name is the name of the network interface.
+	name string
+
+	// leases is a set of leases sorted by hardware address.
+	leases []*Lease
+
+	// leaseTTL is the default Time-To-Live value for leases.
+	leaseTTL time.Duration
+}
+
+// reset clears all the slices in iface for reuse.
+func (iface *netInterface) reset() {
+	iface.leases = iface.leases[:0]
+}
+
+// insertLease inserts the given lease into iface.  It returns an error if the
+// lease can't be inserted.
+func (iface *netInterface) insertLease(l *Lease) (err error) {
+	i, found := slices.BinarySearchFunc(iface.leases, l, compareLeaseMAC)
+	if found {
+		return fmt.Errorf("lease for mac %s already exists", l.HWAddr)
+	}
+
+	iface.leases = slices.Insert(iface.leases, i, l)
+
+	return nil
+}
+
+// updateLease replaces an existing lease within iface with the given one.  It
+// returns an error if there is no lease with such hardware address.
+func (iface *netInterface) updateLease(l *Lease) (prev *Lease, err error) {
+	i, found := slices.BinarySearchFunc(iface.leases, l, compareLeaseMAC)
+	if !found {
+		return nil, fmt.Errorf("no lease for mac %s", l.HWAddr)
+	}
+
+	prev, iface.leases[i] = iface.leases[i], l
+
+	return prev, nil
+}
+
+// removeLease removes an existing lease from iface.  It returns an error if
+// there is no lease equal to l.
+func (iface *netInterface) removeLease(l *Lease) (err error) {
+	i, found := slices.BinarySearchFunc(iface.leases, l, compareLeaseMAC)
+	if !found {
+		return fmt.Errorf("no lease for mac %s", l.HWAddr)
+	}
+
+	iface.leases = slices.Delete(iface.leases, i, i+1)
+
+	return nil
+}