renew dhcp lease on link up

pkg/nmlite/dhcp.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/jetkvm/kvm/internal/network/types"
 	"github.com/jetkvm/kvm/pkg/nmlite/jetdhcpc"
+	"github.com/jetkvm/kvm/pkg/nmlite/udhcpc"
 	"github.com/rs/zerolog"
 	"github.com/vishvananda/netlink"
 )
@@ -68,17 +69,16 @@ func (dc *DHCPClient) SetOnLeaseChange(callback func(lease *types.DHCPLease)) {
 	dc.onLeaseChange = callback
 }
 
-// Start starts the DHCP client
-func (dc *DHCPClient) Start() error {
-	if dc.client != nil {
-		dc.logger.Warn().Msg("DHCP client already started")
-		return nil
+func (dc *DHCPClient) initClient() (types.DHCPClient, error) {
+	if false {
+		return dc.initJetDHCPC()
+	} else {
+		return dc.initUDHCPC()
 	}
+}
 
-	dc.logger.Info().Msg("starting DHCP client")
-
-	// Create the underlying DHCP client
-	client, err := jetdhcpc.NewClient(dc.ctx, []string{dc.ifaceName}, &jetdhcpc.Config{
+func (dc *DHCPClient) initJetDHCPC() (types.DHCPClient, error) {
+	return jetdhcpc.NewClient(dc.ctx, []string{dc.ifaceName}, &jetdhcpc.Config{
 		IPv4: dc.ipv4Enabled,
 		IPv6: dc.ipv6Enabled,
 		OnLease4Change: func(lease *types.DHCPLease) {
@@ -95,6 +95,31 @@ func (dc *DHCPClient) Start() error {
 			return nil
 		},
 	}, dc.logger)
+}
+
+func (dc *DHCPClient) initUDHCPC() (types.DHCPClient, error) {
+	c := udhcpc.NewDHCPClient(&udhcpc.DHCPClientOptions{
+		InterfaceName: dc.ifaceName,
+		PidFile:       "",
+		Logger:        dc.logger,
+		OnLeaseChange: func(lease *types.DHCPLease) {
+			dc.handleLeaseChange(lease, false)
+		},
+	})
+	return c, nil
+}
+
+// Start starts the DHCP client
+func (dc *DHCPClient) Start() error {
+	if dc.client != nil {
+		dc.logger.Warn().Msg("DHCP client already started")
+		return nil
+	}
+
+	dc.logger.Info().Msg("starting DHCP client")
+
+	// Create the underlying DHCP client
+	client, err := dc.initClient()
 
 	if err != nil {
 		return fmt.Errorf("failed to create DHCP client: %w", err)

pkg/nmlite/interface.go

@@ -493,6 +493,10 @@ func (im *InterfaceManager) handleLinkUp() {
 	im.logger.Info().Msg("link up")
 
 	im.applyConfiguration()
+
+	if im.config.IPv4Mode.String == "dhcp" {
+		im.dhcpClient.Renew()
+	}
 }
 
 func (im *InterfaceManager) handleLinkDown() {

pkg/nmlite/udhcpc/parser.go

@@ -38,6 +38,11 @@ func (l *Lease) ToJSON() string {
 	return string(json)
 }
 
+// ToDHCPLease converts a lease to a DHCP lease.
+func (l *Lease) ToDHCPLease() *types.DHCPLease {
+	return &l.DHCPLease
+}
+
 // SetLeaseExpiry sets the lease expiry time.
 func (l *Lease) SetLeaseExpiry() (time.Time, error) {
 	if l.Uptime == 0 || l.LeaseTime == 0 {

pkg/nmlite/udhcpc/udhcpc.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"path/filepath"
 	"reflect"
+	"sync"
 	"time"
 
 	"github.com/fsnotify/fsnotify"
@@ -26,14 +27,15 @@ type DHCPClient struct {
 	lease         *Lease
 	logger        *zerolog.Logger
 	process       *os.Process
-	onLeaseChange func(lease *Lease)
+	runOnce       sync.Once
+	onLeaseChange func(lease *types.DHCPLease)
 }
 
 type DHCPClientOptions struct {
 	InterfaceName string
 	PidFile       string
 	Logger        *zerolog.Logger
-	OnLeaseChange func(lease *Lease)
+	OnLeaseChange func(lease *types.DHCPLease)
 }
 
 var defaultLogger = zerolog.New(os.Stdout).Level(zerolog.InfoLevel)
@@ -69,8 +71,8 @@ func (c *DHCPClient) getWatchPaths() []string {
 }
 
 // Run starts the DHCP client and watches the lease file for changes.
-// this isn't a blocking call, and the lease file is reloaded when a change is detected.
-func (c *DHCPClient) Run() error {
+// this is a blocking call.
+func (c *DHCPClient) run() error {
 	err := c.loadLeaseFile()
 	if err != nil && !errors.Is(err, os.ErrNotExist) {
 		return err
@@ -127,7 +129,7 @@ func (c *DHCPClient) Run() error {
 	// 	c.logger.Error().Msg("udhcpc process not found")
 	// }
 
-	// block the goroutine until the lease file is updated
+	// block the goroutine
 	<-make(chan struct{})
 
 	return nil
@@ -184,7 +186,7 @@ func (c *DHCPClient) loadLeaseFile() error {
 			Msg("current dhcp lease expiry time calculated")
 	}
 
-	c.onLeaseChange(lease)
+	c.onLeaseChange(lease.ToDHCPLease())
 
 	c.logger.Info().
 		Str("ip", lease.IPAddress.String()).
@@ -203,12 +205,16 @@ func (c *DHCPClient) Domain() string {
 	return c.lease.Domain
 }
 
-func (c *DHCPClient) Lease4() *Lease {
-	return c.lease
+func (c *DHCPClient) Lease4() *types.DHCPLease {
+	if c.lease == nil {
+		return nil
+	}
+	return c.lease.ToDHCPLease()
 }
 
-func (c *DHCPClient) Lease6() *Lease {
-	return c.lease
+func (c *DHCPClient) Lease6() *types.DHCPLease {
+	// TODO: implement
+	return nil
 }
 
 func (c *DHCPClient) SetIPv4(enabled bool) {
@@ -219,12 +225,20 @@ func (c *DHCPClient) SetIPv6(enabled bool) {
 	// TODO: implement
 }
 
-func (c *DHCPClient) SetOnLeaseChange(callback func(lease *Lease)) {
+func (c *DHCPClient) SetOnLeaseChange(callback func(lease *types.DHCPLease)) {
 	c.onLeaseChange = callback
 }
 
 func (c *DHCPClient) Start() error {
-	return c.Run() // udhcpc already has Run()
+	c.runOnce.Do(func() {
+		go func() {
+			err := c.run()
+			if err != nil {
+				c.logger.Error().Err(err).Msg("failed to run udhcpc")
+			}
+		}()
+	})
+	return nil
 }
 
 func (c *DHCPClient) Stop() error {