use sync trace to track mutexes to make deadlock analysis easier

.vscode/settings.json

@@ -3,5 +3,11 @@
     "cva",
     "cx"
   ],
+  "gopls": {
+    "build.buildFlags": [
+      "-tags",
+      "synctrace"
+    ]
+  },
   "git.ignoreLimitWarning": true
 }

internal/network/types/type.go

@@ -45,6 +45,8 @@ type IPv6StaticConfig struct {
 
 // NetworkConfig represents the complete network configuration for an interface
 type NetworkConfig struct {
+	DHCPClient null.String `json:"dhcp_client,omitempty" one_of:"jetdhcpc,udhcpc" default:"jetdhcpc"`
+
 	Hostname  null.String `json:"hostname,omitempty" validate_type:"hostname"`
 	HTTPProxy null.String `json:"http_proxy,omitempty" validate_type:"proxy"`
 	Domain    null.String `json:"domain,omitempty" validate_type:"hostname"`
@@ -145,6 +147,7 @@ type DHCPLease struct {
 	LeaseExpiry       *time.Time    `json:"lease_expiry,omitempty"`                    // The expiry time of the lease
 
 	InterfaceName string `json:"interface_name,omitempty"` // The name of the interface
+	DHCPClient    string `json:"dhcp_client,omitempty"`    // The DHCP client that obtained the lease
 }
 
 // InterfaceState represents the current state of a network interface
@@ -173,6 +176,31 @@ type NetworkConfigInterface interface {
 	IPv6Addresses() []IPAddress
 }
 
+// IsIPv6 returns true if the DHCP lease is for an IPv6 address
 func (d *DHCPLease) IsIPv6() bool {
 	return d.IPAddress.To4() == nil
 }
+
+// IPMask returns the IP mask for the DHCP lease
+func (d *DHCPLease) IPMask() net.IPMask {
+	if d.IsIPv6() {
+		// TODO: not implemented
+		return nil
+	}
+
+	mask := net.ParseIP(d.Netmask.String())
+	return net.IPv4Mask(mask[12], mask[13], mask[14], mask[15])
+}
+
+// IPNet returns the IP net for the DHCP lease
+func (d *DHCPLease) IPNet() *net.IPNet {
+	if d.IsIPv6() {
+		// TODO: not implemented
+		return nil
+	}
+
+	return &net.IPNet{
+		IP:   d.IPAddress,
+		Mask: d.IPMask(),
+	}
+}

internal/timesync/ntp.go

@@ -62,6 +62,7 @@ func (t *TimeSync) filterNTPServers(ntpServers []string) ([]string, error) {
 		if ip == nil {
 			continue
 		}
+
 		if hasIPv4 && ip.To4() != nil {
 			filteredServers = append(filteredServers, server)
 		}

internal/timesync/timesync.go

@@ -169,6 +169,9 @@ func (t *TimeSync) doTimeSync() {
 }
 
 func (t *TimeSync) Sync() error {
+	t.syncLock.Lock()
+	defer t.syncLock.Unlock()
+
 	var (
 		now    *time.Time
 		offset *time.Duration

pkg/nmlite/dhcp.go

@@ -18,21 +18,19 @@ type DHCPClient struct {
 	ifaceName  string
 	logger     *zerolog.Logger
 	client     types.DHCPClient
+	clientType string
 	link       netlink.Link
 
 	// Configuration
 	ipv4Enabled bool
 	ipv6Enabled bool
 
-	// State management
-	// stateManager *DHCPStateManager
-
 	// Callbacks
 	onLeaseChange func(lease *types.DHCPLease)
 }
 
 // NewDHCPClient creates a new DHCP client
-func NewDHCPClient(ctx context.Context, ifaceName string, logger *zerolog.Logger) (*DHCPClient, error) {
+func NewDHCPClient(ctx context.Context, ifaceName string, logger *zerolog.Logger, clientType string) (*DHCPClient, error) {
 	if ifaceName == "" {
 		return nil, fmt.Errorf("interface name cannot be empty")
 	}
@@ -45,6 +43,7 @@ func NewDHCPClient(ctx context.Context, ifaceName string, logger *zerolog.Logger
 		ctx:        ctx,
 		ifaceName:  ifaceName,
 		logger:     logger,
+		clientType: clientType,
 	}, nil
 }
 
@@ -70,10 +69,13 @@ func (dc *DHCPClient) SetOnLeaseChange(callback func(lease *types.DHCPLease)) {
 }
 
 func (dc *DHCPClient) initClient() (types.DHCPClient, error) {
-	if false {
+	switch dc.clientType {
+	case "jetdhcpc":
 		return dc.initJetDHCPC()
-	} else {
+	case "udhcpc":
 		return dc.initUDHCPC()
+	default:
+		return nil, fmt.Errorf("invalid client type: %s", dc.clientType)
 	}
 }
 
@@ -204,8 +206,11 @@ func (dc *DHCPClient) handleLeaseChange(lease *types.DHCPLease, isIPv6 bool) {
 		Str("ip", lease.IPAddress.String()).
 		Msg("DHCP lease changed")
 
+	// copy the lease to avoid race conditions
+	leaseCopy := *lease
+
 	// Notify callback
 	if dc.onLeaseChange != nil {
-		dc.onLeaseChange(lease)
+		dc.onLeaseChange(&leaseCopy)
 	}
 }

pkg/nmlite/hostname.go

@@ -6,7 +6,8 @@ import (
 	"os"
 	"os/exec"
 	"strings"
-	"sync"
+
+	"github.com/jetkvm/kvm/internal/sync"
 
 	"github.com/rs/zerolog"
 	"golang.org/x/net/idna"

pkg/nmlite/interface.go

@@ -4,9 +4,11 @@ import (
 	"context"
 	"fmt"
 	"net"
-	"sync"
+
 	"time"
 
+	"github.com/jetkvm/kvm/internal/sync"
+
 	"github.com/jetkvm/kvm/internal/confparser"
 	"github.com/jetkvm/kvm/internal/logging"
 	"github.com/jetkvm/kvm/internal/network/types"
@@ -78,7 +80,7 @@ func NewInterfaceManager(ctx context.Context, ifaceName string, config *types.Ne
 	}
 
 	// create the dhcp client
-	im.dhcpClient, err = NewDHCPClient(ctx, ifaceName, &scopedLogger)
+	im.dhcpClient, err = NewDHCPClient(ctx, ifaceName, &scopedLogger, config.DHCPClient.String)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create DHCP client: %w", err)
 	}
@@ -562,7 +564,6 @@ func (im *InterfaceManager) monitorInterfaceState() {
 	defer im.wg.Done()
 
 	im.logger.Debug().Msg("monitoring interface state")
-
 	// TODO: use netlink subscription instead of polling
 	ticker := time.NewTicker(5 * time.Second)
 	defer ticker.Stop()
@@ -574,7 +575,6 @@ func (im *InterfaceManager) monitorInterfaceState() {
 		case <-im.stopCh:
 			return
 		case <-ticker.C:
-			im.logger.Debug().Msg("checking interface state")
 			if err := im.updateInterfaceState(); err != nil {
 				im.logger.Error().Err(err).Msg("failed to update interface state")
 			}
@@ -727,12 +727,9 @@ func (im *InterfaceManager) applyDHCPLease(lease *types.DHCPLease) error {
 
 // convertDHCPLeaseToIPv4Config converts a DHCP lease to IPv4Config
 func (im *InterfaceManager) convertDHCPLeaseToIPv4Config(lease *types.DHCPLease) *types.IPAddress {
-	mask := lease.Netmask
-
-	// Create IPNet from IP and netmask
-	ipNet := &net.IPNet{
-		IP:   lease.IPAddress,
-		Mask: net.IPv4Mask(mask[12], mask[13], mask[14], mask[15]),
+	ipNet := lease.IPNet()
+	if ipNet == nil {
+		return nil
 	}
 
 	// Create IPv4Address

pkg/nmlite/jetdhcpc/client.go

@@ -6,9 +6,11 @@ import (
 	"fmt"
 	"net"
 	"slices"
-	"sync"
+
 	"time"
 
+	"github.com/jetkvm/kvm/internal/sync"
+
 	"github.com/go-co-op/gocron/v2"
 	"github.com/insomniacslk/dhcp/dhcpv4"
 	"github.com/insomniacslk/dhcp/dhcpv6"

pkg/nmlite/jetdhcpc/lease.go

@@ -33,7 +33,9 @@ type Lease struct {
 
 // ToDHCPLease converts a lease to a DHCP lease.
 func (l *Lease) ToDHCPLease() *types.DHCPLease {
-	return &l.DHCPLease
+	lease := &l.DHCPLease
+	lease.DHCPClient = "jetdhcpc"
+	return lease
 }
 
 // fromNclient4Lease creates a lease from a nclient4.Lease.
@@ -45,9 +47,9 @@ func fromNclient4Lease(l *nclient4.Lease, iface string) *Lease {
 	// only the fields that we need are set
 	lease.Routers = l.ACK.Router()
 	lease.IPAddress = l.ACK.YourIPAddr
+
 	lease.Netmask = net.IP(l.ACK.SubnetMask())
 	lease.Broadcast = l.ACK.BroadcastAddress()
-	// lease.MTU = int(resp.Options.Get(dhcpv4.OptionInterfaceMTU))
 
 	lease.NTPServers = l.ACK.NTPServers()
 

pkg/nmlite/link/netlink.go

@@ -10,9 +10,10 @@ import (
 	"path"
 	"strconv"
 	"strings"
-	"sync"
 	"time"
 
+	"github.com/jetkvm/kvm/internal/sync"
+
 	"github.com/jetkvm/kvm/internal/network/types"
 	"github.com/rs/zerolog"
 	"github.com/vishvananda/netlink"

pkg/nmlite/manager.go

@@ -6,7 +6,8 @@ package nmlite
 import (
 	"context"
 	"fmt"
-	"sync"
+
+	"github.com/jetkvm/kvm/internal/sync"
 
 	"github.com/jetkvm/kvm/internal/logging"
 	"github.com/jetkvm/kvm/internal/network/types"

pkg/nmlite/udhcpc/parser.go

@@ -40,7 +40,9 @@ func (l *Lease) ToJSON() string {
 
 // ToDHCPLease converts a lease to a DHCP lease.
 func (l *Lease) ToDHCPLease() *types.DHCPLease {
-	return &l.DHCPLease
+	lease := &l.DHCPLease
+	lease.DHCPClient = "udhcpc"
+	return lease
 }
 
 // SetLeaseExpiry sets the lease expiry time.

pkg/nmlite/udhcpc/udhcpc.go

@@ -6,9 +6,11 @@ import (
 	"os"
 	"path/filepath"
 	"reflect"
-	"sync"
+
 	"time"
 
+	"github.com/jetkvm/kvm/internal/sync"
+
 	"github.com/fsnotify/fsnotify"
 	"github.com/jetkvm/kvm/internal/network/types"
 	"github.com/rs/zerolog"

ui/src/components/DhcpLeaseCard.tsx

@@ -221,6 +221,13 @@ export default function DhcpLeaseCard({
                   </span>
                 </div>
               )}
+
+              {networkState?.dhcp_lease?.dhcp_client && (
+                <div className="flex justify-between border-t border-slate-800/10 pt-2 dark:border-slate-300/20">
+                  <span className="text-sm text-slate-600 dark:text-slate-400">DHCP Client</span>
+                  <span className="text-sm font-medium">{networkState?.dhcp_lease?.dhcp_client}</span>
+                </div>
+              )}
             </div>
           </div>
         </div>

ui/src/hooks/stores.ts

@@ -690,6 +690,7 @@ export interface DhcpLease {
   message?: string;
   tftp?: string;
   bootfile?: string;
+  dhcp_client?: string;
 }
 
 export interface IPv6Address {