all: sync with master; upd chlog

internal/dhcpd/migrate.go

@@ -0,0 +1,106 @@
+package dhcpd
+
+import (
+	"encoding/json"
+	"net"
+	"net/netip"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/AdguardTeam/golibs/errors"
+	"github.com/AdguardTeam/golibs/log"
+)
+
+const (
+	// leaseExpireStatic is used to define the Expiry field for static
+	// leases.
+	//
+	// Deprecated:  Remove it when migration of DHCP leases will be not needed.
+	leaseExpireStatic = 1
+
+	// dbFilename contains saved leases.
+	//
+	// Deprecated:  Use dataFilename.
+	dbFilename = "leases.db"
+)
+
+// leaseJSON is the structure of stored lease.
+//
+// Deprecated:  Use [Lease].
+type leaseJSON struct {
+	HWAddr   []byte `json:"mac"`
+	IP       []byte `json:"ip"`
+	Hostname string `json:"host"`
+	Expiry   int64  `json:"exp"`
+}
+
+func normalizeIP(ip net.IP) net.IP {
+	ip4 := ip.To4()
+	if ip4 != nil {
+		return ip4
+	}
+
+	return ip
+}
+
+// migrateDB migrates stored leases if necessary.
+func migrateDB(conf *ServerConfig) (err error) {
+	defer func() { err = errors.Annotate(err, "migrating db: %w") }()
+
+	oldLeasesPath := filepath.Join(conf.WorkDir, dbFilename)
+	dataDirPath := filepath.Join(conf.DataDir, dataFilename)
+
+	file, err := os.Open(oldLeasesPath)
+	if errors.Is(err, os.ErrNotExist) {
+		// Nothing to migrate.
+		return nil
+	} else if err != nil {
+		// Don't wrap the error since it's informative enough as is.
+		return err
+	}
+
+	ljs := []leaseJSON{}
+	err = json.NewDecoder(file).Decode(&ljs)
+	if err != nil {
+		// Don't wrap the error since it's informative enough as is.
+		return err
+	}
+
+	err = file.Close()
+	if err != nil {
+		// Don't wrap the error since it's informative enough as is.
+		return err
+	}
+
+	leases := []*Lease{}
+
+	for _, lj := range ljs {
+		lj.IP = normalizeIP(lj.IP)
+
+		ip, ok := netip.AddrFromSlice(lj.IP)
+		if !ok {
+			log.Info("dhcp: invalid IP: %s", lj.IP)
+
+			continue
+		}
+
+		lease := &Lease{
+			Expiry:   time.Unix(lj.Expiry, 0),
+			Hostname: lj.Hostname,
+			HWAddr:   lj.HWAddr,
+			IP:       ip,
+			IsStatic: lj.Expiry == leaseExpireStatic,
+		}
+
+		leases = append(leases, lease)
+	}
+
+	err = writeDB(dataDirPath, leases)
+	if err != nil {
+		// Don't wrap the error since it's informative enough as is.
+		return err
+	}
+
+	return os.Remove(oldLeasesPath)
+}