142 lines
3.6 KiB
Go
142 lines
3.6 KiB
Go
package dhcpsvc
|
|
|
|
import (
|
|
"fmt"
|
|
"net/netip"
|
|
"slices"
|
|
"strings"
|
|
)
|
|
|
|
// leaseIndex is the set of leases indexed by their identifiers for quick
|
|
// lookup.
|
|
type leaseIndex struct {
|
|
// byAddr is a lookup shortcut for leases by their IP addresses.
|
|
byAddr map[netip.Addr]*Lease
|
|
|
|
// byName is a lookup shortcut for leases by their hostnames.
|
|
//
|
|
// TODO(e.burkov): Use a slice of leases with the same hostname?
|
|
byName map[string]*Lease
|
|
}
|
|
|
|
// newLeaseIndex returns a new index for [Lease]s.
|
|
func newLeaseIndex() *leaseIndex {
|
|
return &leaseIndex{
|
|
byAddr: map[netip.Addr]*Lease{},
|
|
byName: map[string]*Lease{},
|
|
}
|
|
}
|
|
|
|
// leaseByAddr returns a lease by its IP address.
|
|
func (idx *leaseIndex) leaseByAddr(addr netip.Addr) (l *Lease, ok bool) {
|
|
l, ok = idx.byAddr[addr]
|
|
|
|
return l, ok
|
|
}
|
|
|
|
// leaseByName returns a lease by its hostname.
|
|
func (idx *leaseIndex) leaseByName(name string) (l *Lease, ok bool) {
|
|
// TODO(e.burkov): Probably, use a case-insensitive comparison and store in
|
|
// slice. This would require a benchmark.
|
|
l, ok = idx.byName[strings.ToLower(name)]
|
|
|
|
return l, ok
|
|
}
|
|
|
|
// clear removes all leases from idx.
|
|
func (idx *leaseIndex) clear() {
|
|
clear(idx.byAddr)
|
|
clear(idx.byName)
|
|
}
|
|
|
|
// add adds l into idx and into iface. l must be valid, iface should be
|
|
// responsible for l's IP. It returns an error if l duplicates at least a
|
|
// single value of another lease.
|
|
func (idx *leaseIndex) add(l *Lease, iface *netInterface) (err error) {
|
|
loweredName := strings.ToLower(l.Hostname)
|
|
|
|
if _, ok := idx.byAddr[l.IP]; ok {
|
|
return fmt.Errorf("lease for ip %s already exists", l.IP)
|
|
} else if _, ok = idx.byName[loweredName]; ok {
|
|
return fmt.Errorf("lease for hostname %s already exists", l.Hostname)
|
|
}
|
|
|
|
err = iface.addLease(l)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
idx.byAddr[l.IP] = l
|
|
idx.byName[loweredName] = l
|
|
|
|
return nil
|
|
}
|
|
|
|
// remove removes l from idx and from iface. l must be valid, iface should
|
|
// contain the same lease or the lease itself. It returns an error if the lease
|
|
// not found.
|
|
func (idx *leaseIndex) remove(l *Lease, iface *netInterface) (err error) {
|
|
loweredName := strings.ToLower(l.Hostname)
|
|
|
|
if _, ok := idx.byAddr[l.IP]; !ok {
|
|
return fmt.Errorf("no lease for ip %s", l.IP)
|
|
} else if _, ok = idx.byName[loweredName]; !ok {
|
|
return fmt.Errorf("no lease for hostname %s", l.Hostname)
|
|
}
|
|
|
|
err = iface.removeLease(l)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
delete(idx.byAddr, l.IP)
|
|
delete(idx.byName, loweredName)
|
|
|
|
return nil
|
|
}
|
|
|
|
// update updates l in idx and in iface. l must be valid, iface should be
|
|
// responsible for l's IP. It returns an error if l duplicates at least a
|
|
// single value of another lease, except for the updated lease itself.
|
|
func (idx *leaseIndex) update(l *Lease, iface *netInterface) (err error) {
|
|
loweredName := strings.ToLower(l.Hostname)
|
|
|
|
existing, ok := idx.byAddr[l.IP]
|
|
if ok && !slices.Equal(l.HWAddr, existing.HWAddr) {
|
|
return fmt.Errorf("lease for ip %s already exists", l.IP)
|
|
}
|
|
|
|
existing, ok = idx.byName[loweredName]
|
|
if ok && !slices.Equal(l.HWAddr, existing.HWAddr) {
|
|
return fmt.Errorf("lease for hostname %s already exists", l.Hostname)
|
|
}
|
|
|
|
prev, err := iface.updateLease(l)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
delete(idx.byAddr, prev.IP)
|
|
delete(idx.byName, strings.ToLower(prev.Hostname))
|
|
|
|
idx.byAddr[l.IP] = l
|
|
idx.byName[loweredName] = l
|
|
|
|
return nil
|
|
}
|
|
|
|
// rangeLeases calls f for each lease in idx in an unspecified order until f
|
|
// returns false.
|
|
func (idx *leaseIndex) rangeLeases(f func(l *Lease) (cont bool)) {
|
|
for _, l := range idx.byName {
|
|
if !f(l) {
|
|
break
|
|
}
|
|
}
|
|
}
|
|
|
|
// len returns the number of leases in idx.
|
|
func (idx *leaseIndex) len() (l uint) {
|
|
return uint(len(idx.byAddr))
|
|
}
|