Add userspace flow implementation (#3393)

client/firewall/create.go

@@ -10,17 +10,18 @@ import (
 
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/firewall/uspfilter"
+	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 )
 
 // NewFirewall creates a firewall manager instance
-func NewFirewall(iface IFaceMapper, _ *statemanager.Manager, disableServerRoutes bool) (firewall.Manager, error) {
+func NewFirewall(iface IFaceMapper, _ *statemanager.Manager, flowLogger nftypes.FlowLogger, disableServerRoutes bool) (firewall.Manager, error) {
 	if !iface.IsUserspaceBind() {
 		return nil, fmt.Errorf("not implemented for this OS: %s", runtime.GOOS)
 	}
 
 	// use userspace packet filtering firewall
-	fm, err := uspfilter.Create(iface, disableServerRoutes)
+	fm, err := uspfilter.Create(iface, disableServerRoutes, flowLogger)
 	if err != nil {
 		return nil, err
 	}

client/firewall/create_linux.go

@@ -15,6 +15,7 @@ import (
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	nbnftables "github.com/netbirdio/netbird/client/firewall/nftables"
 	"github.com/netbirdio/netbird/client/firewall/uspfilter"
+	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 )
 
@@ -33,7 +34,7 @@ const SKIP_NFTABLES_ENV = "NB_SKIP_NFTABLES_CHECK"
 // FWType is the type for the firewall type
 type FWType int
 
-func NewFirewall(iface IFaceMapper, stateManager *statemanager.Manager, disableServerRoutes bool) (firewall.Manager, error) {
+func NewFirewall(iface IFaceMapper, stateManager *statemanager.Manager, flowLogger nftypes.FlowLogger, disableServerRoutes bool) (firewall.Manager, error) {
 	// on the linux system we try to user nftables or iptables
 	// in any case, because we need to allow netbird interface traffic
 	// so we use AllowNetbird traffic from these firewall managers
@@ -47,7 +48,7 @@ func NewFirewall(iface IFaceMapper, stateManager *statemanager.Manager, disableS
 	if err != nil {
 		log.Warnf("failed to create native firewall: %v. Proceeding with userspace", err)
 	}
-	return createUserspaceFirewall(iface, fm, disableServerRoutes)
+	return createUserspaceFirewall(iface, fm, disableServerRoutes, flowLogger)
 }
 
 func createNativeFirewall(iface IFaceMapper, stateManager *statemanager.Manager, routes bool) (firewall.Manager, error) {
@@ -77,12 +78,12 @@ func createFW(iface IFaceMapper) (firewall.Manager, error) {
 	}
 }
 
-func createUserspaceFirewall(iface IFaceMapper, fm firewall.Manager, disableServerRoutes bool) (firewall.Manager, error) {
+func createUserspaceFirewall(iface IFaceMapper, fm firewall.Manager, disableServerRoutes bool, flowLogger nftypes.FlowLogger) (firewall.Manager, error) {
 	var errUsp error
 	if fm != nil {
-		fm, errUsp = uspfilter.CreateWithNativeFirewall(iface, fm, disableServerRoutes)
+		fm, errUsp = uspfilter.CreateWithNativeFirewall(iface, fm, disableServerRoutes, flowLogger)
 	} else {
-		fm, errUsp = uspfilter.Create(iface, disableServerRoutes)
+		fm, errUsp = uspfilter.Create(iface, disableServerRoutes, flowLogger)
 	}
 
 	if errUsp != nil {

client/firewall/uspfilter/allow_netbird.go

@@ -22,17 +22,17 @@ func (m *Manager) Reset(stateManager *statemanager.Manager) error {
 
 	if m.udpTracker != nil {
 		m.udpTracker.Close()
-		m.udpTracker = conntrack.NewUDPTracker(conntrack.DefaultUDPTimeout, m.logger)
+		m.udpTracker = conntrack.NewUDPTracker(conntrack.DefaultUDPTimeout, m.logger, m.flowLogger)
 	}
 
 	if m.icmpTracker != nil {
 		m.icmpTracker.Close()
-		m.icmpTracker = conntrack.NewICMPTracker(conntrack.DefaultICMPTimeout, m.logger)
+		m.icmpTracker = conntrack.NewICMPTracker(conntrack.DefaultICMPTimeout, m.logger, m.flowLogger)
 	}
 
 	if m.tcpTracker != nil {
 		m.tcpTracker.Close()
-		m.tcpTracker = conntrack.NewTCPTracker(conntrack.DefaultTCPTimeout, m.logger)
+		m.tcpTracker = conntrack.NewTCPTracker(conntrack.DefaultTCPTimeout, m.logger, m.flowLogger)
 	}
 
 	if m.forwarder != nil {

client/firewall/uspfilter/allow_netbird_windows.go

@@ -31,17 +31,17 @@ func (m *Manager) Reset(*statemanager.Manager) error {
 
 	if m.udpTracker != nil {
 		m.udpTracker.Close()
-		m.udpTracker = conntrack.NewUDPTracker(conntrack.DefaultUDPTimeout, m.logger)
+		m.udpTracker = conntrack.NewUDPTracker(conntrack.DefaultUDPTimeout, m.logger, m.flowLogger)
 	}
 
 	if m.icmpTracker != nil {
 		m.icmpTracker.Close()
-		m.icmpTracker = conntrack.NewICMPTracker(conntrack.DefaultICMPTimeout, m.logger)
+		m.icmpTracker = conntrack.NewICMPTracker(conntrack.DefaultICMPTimeout, m.logger, m.flowLogger)
 	}
 
 	if m.tcpTracker != nil {
 		m.tcpTracker.Close()
-		m.tcpTracker = conntrack.NewTCPTracker(conntrack.DefaultTCPTimeout, m.logger)
+		m.tcpTracker = conntrack.NewTCPTracker(conntrack.DefaultTCPTimeout, m.logger, m.flowLogger)
 	}
 
 	if m.forwarder != nil {

client/firewall/uspfilter/conntrack/common.go

@@ -1,20 +1,26 @@
-// common.go
 package conntrack
 
 import (
+	"fmt"
 	"net"
-	"sync"
+	"net/netip"
 	"sync/atomic"
 	"time"
+
+	"github.com/google/uuid"
+
+	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
 )
 
 // BaseConnTrack provides common fields and locking for all connection types
 type BaseConnTrack struct {
-	SourceIP   net.IP
+	FlowId     uuid.UUID
-	DestIP     net.IP
+	Direction  nftypes.Direction
+	SourceIP   netip.Addr
+	DestIP     netip.Addr
 	SourcePort uint16
 	DestPort   uint16
-	lastSeen   atomic.Int64 // Unix nano for atomic access
+	lastSeen   atomic.Int64
 }
 
 // these small methods will be inlined by the compiler
@@ -35,92 +41,27 @@ func (b *BaseConnTrack) timeoutExceeded(timeout time.Duration) bool {
 	return time.Since(lastSeen) > timeout
 }
 
-// IPAddr is a fixed-size IP address to avoid allocations
-type IPAddr [16]byte
-
-// MakeIPAddr creates an IPAddr from net.IP
-func MakeIPAddr(ip net.IP) (addr IPAddr) {
-	// Optimization: check for v4 first as it's more common
-	if ip4 := ip.To4(); ip4 != nil {
-		copy(addr[12:], ip4)
-	} else {
-		copy(addr[:], ip.To16())
-	}
-	return addr
-}
-
 // ConnKey uniquely identifies a connection
 type ConnKey struct {
-	SrcIP   IPAddr
+	SrcIP   netip.Addr
-	DstIP   IPAddr
+	DstIP   netip.Addr
 	SrcPort uint16
 	DstPort uint16
 }
 
+func (c ConnKey) String() string {
+	return fmt.Sprintf("%s:%d -> %s:%d", c.SrcIP.Unmap(), c.SrcPort, c.DstIP.Unmap(), c.DstPort)
+}
+
 // makeConnKey creates a connection key
 func makeConnKey(srcIP net.IP, dstIP net.IP, srcPort uint16, dstPort uint16) ConnKey {
+	srcAddr, _ := netip.AddrFromSlice(srcIP)
+	dstAddr, _ := netip.AddrFromSlice(dstIP)
+
 	return ConnKey{
-		SrcIP:   MakeIPAddr(srcIP),
+		SrcIP:   srcAddr,
-		DstIP:   MakeIPAddr(dstIP),
+		DstIP:   dstAddr,
 		SrcPort: srcPort,
 		DstPort: dstPort,
 	}
 }
-
-// ValidateIPs checks if IPs match without allocation
-func ValidateIPs(connIP IPAddr, pktIP net.IP) bool {
-	if ip4 := pktIP.To4(); ip4 != nil {
-		// Compare IPv4 addresses (last 4 bytes)
-		for i := 0; i < 4; i++ {
-			if connIP[12+i] != ip4[i] {
-				return false
-			}
-		}
-		return true
-	}
-	// Compare full IPv6 addresses
-	ip6 := pktIP.To16()
-	for i := 0; i < 16; i++ {
-		if connIP[i] != ip6[i] {
-			return false
-		}
-	}
-	return true
-}
-
-// PreallocatedIPs is a pool of IP byte slices to reduce allocations
-type PreallocatedIPs struct {
-	sync.Pool
-}
-
-// NewPreallocatedIPs creates a new IP pool
-func NewPreallocatedIPs() *PreallocatedIPs {
-	return &PreallocatedIPs{
-		Pool: sync.Pool{
-			New: func() interface{} {
-				ip := make(net.IP, 16)
-				return &ip
-			},
-		},
-	}
-}
-
-// Get retrieves an IP from the pool
-func (p *PreallocatedIPs) Get() net.IP {
-	return *p.Pool.Get().(*net.IP)
-}
-
-// Put returns an IP to the pool
-func (p *PreallocatedIPs) Put(ip net.IP) {
-	p.Pool.Put(&ip)
-}
-
-// copyIP copies an IP address efficiently
-func copyIP(dst, src net.IP) {
-	if len(src) == 16 {
-		copy(dst, src)
-	} else {
-		// Handle IPv4
-		copy(dst[12:], src.To4())
-	}
-}

client/firewall/uspfilter/conntrack/common_test.go

@@ -1,50 +1,23 @@
 package conntrack
 
 import (
+	"context"
 	"net"
 	"testing"
 
 	"github.com/sirupsen/logrus"
 
 	"github.com/netbirdio/netbird/client/firewall/uspfilter/log"
+	"github.com/netbirdio/netbird/client/internal/netflow"
 )
 
 var logger = log.NewFromLogrus(logrus.StandardLogger())
-
+var flowLogger = netflow.NewManager(context.Background()).GetLogger()
-func BenchmarkIPOperations(b *testing.B) {
-	b.Run("MakeIPAddr", func(b *testing.B) {
-		ip := net.ParseIP("192.168.1.1")
-		b.ResetTimer()
-		for i := 0; i < b.N; i++ {
-			_ = MakeIPAddr(ip)
-		}
-	})
-
-	b.Run("ValidateIPs", func(b *testing.B) {
-		ip1 := net.ParseIP("192.168.1.1")
-		ip2 := net.ParseIP("192.168.1.1")
-		addr := MakeIPAddr(ip1)
-		b.ResetTimer()
-		for i := 0; i < b.N; i++ {
-			_ = ValidateIPs(addr, ip2)
-		}
-	})
-
-	b.Run("IPPool", func(b *testing.B) {
-		pool := NewPreallocatedIPs()
-		b.ResetTimer()
-		for i := 0; i < b.N; i++ {
-			ip := pool.Get()
-			pool.Put(ip)
-		}
-	})
-
-}
 
 // Memory pressure tests
 func BenchmarkMemoryPressure(b *testing.B) {
 	b.Run("TCPHighLoad", func(b *testing.B) {
-		tracker := NewTCPTracker(DefaultTCPTimeout, logger)
+		tracker := NewTCPTracker(DefaultTCPTimeout, logger, flowLogger)
 		defer tracker.Close()
 
 		// Generate different IPs
@@ -69,7 +42,7 @@ func BenchmarkMemoryPressure(b *testing.B) {
 	})
 
 	b.Run("UDPHighLoad", func(b *testing.B) {
-		tracker := NewUDPTracker(DefaultUDPTimeout, logger)
+		tracker := NewUDPTracker(DefaultUDPTimeout, logger, flowLogger)
 		defer tracker.Close()
 
 		// Generate different IPs

client/firewall/uspfilter/conntrack/icmp.go

@@ -1,13 +1,17 @@
 package conntrack
 
 import (
+	"fmt"
 	"net"
+	"net/netip"
 	"sync"
 	"time"
 
 	"github.com/google/gopacket/layers"
+	"github.com/google/uuid"
 
 	nblog "github.com/netbirdio/netbird/client/firewall/uspfilter/log"
+	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
 )
 
 const (
@@ -19,18 +23,19 @@ const (
 
 // ICMPConnKey uniquely identifies an ICMP connection
 type ICMPConnKey struct {
-	// Supports both IPv4 and IPv6
+	SrcIP    netip.Addr
-	SrcIP    [16]byte
+	DstIP    netip.Addr
-	DstIP    [16]byte
+	Sequence uint16
-	Sequence uint16 // ICMP sequence number
+	ID       uint16
-	ID       uint16 // ICMP identifier
+}
+
+func (i *ICMPConnKey) String() string {
+	return fmt.Sprintf("%s -> %s (%d/%d)", i.SrcIP, i.DstIP, i.Sequence, i.ID)
 }
 
 // ICMPConnTrack represents an ICMP connection state
 type ICMPConnTrack struct {
 	BaseConnTrack
-	Sequence uint16
-	ID       uint16
 }
 
 // ICMPTracker manages ICMP connection states
@@ -41,11 +46,11 @@ type ICMPTracker struct {
 	cleanupTicker *time.Ticker
 	mutex         sync.RWMutex
 	done          chan struct{}
-	ipPool        *PreallocatedIPs
+	flowLogger    nftypes.FlowLogger
 }
 
 // NewICMPTracker creates a new ICMP connection tracker
-func NewICMPTracker(timeout time.Duration, logger *nblog.Logger) *ICMPTracker {
+func NewICMPTracker(timeout time.Duration, logger *nblog.Logger, flowLogger nftypes.FlowLogger) *ICMPTracker {
 	if timeout == 0 {
 		timeout = DefaultICMPTimeout
 	}
@@ -56,41 +61,65 @@ func NewICMPTracker(timeout time.Duration, logger *nblog.Logger) *ICMPTracker {
 		timeout:       timeout,
 		cleanupTicker: time.NewTicker(ICMPCleanupInterval),
 		done:          make(chan struct{}),
-		ipPool:        NewPreallocatedIPs(),
+		flowLogger:    flowLogger,
 	}
 
 	go tracker.cleanupRoutine()
 	return tracker
 }
 
-// TrackOutbound records an outbound ICMP Echo Request
+func (t *ICMPTracker) updateIfExists(srcIP net.IP, dstIP net.IP, id uint16, seq uint16) (ICMPConnKey, bool) {
-func (t *ICMPTracker) TrackOutbound(srcIP net.IP, dstIP net.IP, id uint16, seq uint16) {
 	key := makeICMPKey(srcIP, dstIP, id, seq)
 
-	t.mutex.Lock()
+	t.mutex.RLock()
 	conn, exists := t.connections[key]
-	if !exists {
+	t.mutex.RUnlock()
-		srcIPCopy := t.ipPool.Get()
-		dstIPCopy := t.ipPool.Get()
-		copyIP(srcIPCopy, srcIP)
-		copyIP(dstIPCopy, dstIP)
 
-		conn = &ICMPConnTrack{
+	if exists {
-			BaseConnTrack: BaseConnTrack{
-				SourceIP: srcIPCopy,
-				DestIP:   dstIPCopy,
-			},
-			ID:       id,
-			Sequence: seq,
-		}
 		conn.UpdateLastSeen()
-		t.connections[key] = conn
 
-		t.logger.Trace("New ICMP connection %v", key)
+		return key, true
 	}
+
+	return key, false
+}
+
+// TrackOutbound records an outbound ICMP connection
+func (t *ICMPTracker) TrackOutbound(srcIP net.IP, dstIP net.IP, id uint16, seq uint16) {
+	if _, exists := t.updateIfExists(dstIP, srcIP, id, seq); !exists {
+		// if (inverted direction) conn is not tracked, track this direction
+		t.track(srcIP, dstIP, id, seq, nftypes.Egress)
+	}
+}
+
+// TrackInbound records an inbound ICMP Echo Request
+func (t *ICMPTracker) TrackInbound(srcIP net.IP, dstIP net.IP, id uint16, seq uint16) {
+	t.track(srcIP, dstIP, id, seq, nftypes.Ingress)
+}
+
+// track is the common implementation for tracking both inbound and outbound ICMP connections
+func (t *ICMPTracker) track(srcIP net.IP, dstIP net.IP, id uint16, seq uint16, direction nftypes.Direction) {
+	key, exists := t.updateIfExists(srcIP, dstIP, id, seq)
+	if exists {
+		return
+	}
+
+	conn := &ICMPConnTrack{
+		BaseConnTrack: BaseConnTrack{
+			FlowId:    uuid.New(),
+			Direction: direction,
+			SourceIP:  key.SrcIP,
+			DestIP:    key.DstIP,
+		},
+	}
+	conn.UpdateLastSeen()
+
+	t.mutex.Lock()
+	t.connections[key] = conn
 	t.mutex.Unlock()
 
-	conn.UpdateLastSeen()
+	t.logger.Trace("New %s ICMP connection %s", conn.Direction, key)
+	t.sendEvent(nftypes.TypeStart, key, conn)
 }
 
 // IsValidInbound checks if an inbound ICMP Echo Reply matches a tracked request
@@ -105,18 +134,13 @@ func (t *ICMPTracker) IsValidInbound(srcIP net.IP, dstIP net.IP, id uint16, seq
 	conn, exists := t.connections[key]
 	t.mutex.RUnlock()
 
-	if !exists {
+	if !exists || conn.timeoutExceeded(t.timeout) {
 		return false
 	}
 
-	if conn.timeoutExceeded(t.timeout) {
+	conn.UpdateLastSeen()
-		return false
-	}
 
-	return ValidateIPs(MakeIPAddr(srcIP), conn.DestIP) &&
+	return true
-		ValidateIPs(MakeIPAddr(dstIP), conn.SourceIP) &&
-		conn.ID == id &&
-		conn.Sequence == seq
 }
 
 func (t *ICMPTracker) cleanupRoutine() {
@@ -129,17 +153,17 @@ func (t *ICMPTracker) cleanupRoutine() {
 		}
 	}
 }
+
 func (t *ICMPTracker) cleanup() {
 	t.mutex.Lock()
 	defer t.mutex.Unlock()
 
 	for key, conn := range t.connections {
 		if conn.timeoutExceeded(t.timeout) {
-			t.ipPool.Put(conn.SourceIP)
-			t.ipPool.Put(conn.DestIP)
 			delete(t.connections, key)
 
-			t.logger.Debug("Removed ICMP connection %v (timeout)", key)
+			t.logger.Debug("Removed ICMP connection %s (timeout)", &key)
+			t.sendEvent(nftypes.TypeEnd, key, conn)
 		}
 	}
 }
@@ -150,19 +174,29 @@ func (t *ICMPTracker) Close() {
 	close(t.done)
 
 	t.mutex.Lock()
-	for _, conn := range t.connections {
-		t.ipPool.Put(conn.SourceIP)
-		t.ipPool.Put(conn.DestIP)
-	}
 	t.connections = nil
 	t.mutex.Unlock()
 }
 
+func (t *ICMPTracker) sendEvent(typ nftypes.Type, key ICMPConnKey, conn *ICMPConnTrack) {
+	t.flowLogger.StoreEvent(nftypes.EventFields{
+		FlowID:    conn.FlowId,
+		Type:      typ,
+		Direction: conn.Direction,
+		Protocol:  nftypes.ICMP, // TODO: adjust for IPv6/icmpv6
+		SourceIP:  key.SrcIP,
+		DestIP:    key.DstIP,
+		// TODO: add icmp code/type,
+	})
+}
+
 // makeICMPKey creates an ICMP connection key
 func makeICMPKey(srcIP net.IP, dstIP net.IP, id uint16, seq uint16) ICMPConnKey {
+	srcAddr, _ := netip.AddrFromSlice(srcIP)
+	dstAddr, _ := netip.AddrFromSlice(dstIP)
 	return ICMPConnKey{
-		SrcIP:    MakeIPAddr(srcIP),
+		SrcIP:    srcAddr,
-		DstIP:    MakeIPAddr(dstIP),
+		DstIP:    dstAddr,
 		ID:       id,
 		Sequence: seq,
 	}

client/firewall/uspfilter/conntrack/icmp_test.go

@@ -7,7 +7,7 @@ import (
 
 func BenchmarkICMPTracker(b *testing.B) {
 	b.Run("TrackOutbound", func(b *testing.B) {
-		tracker := NewICMPTracker(DefaultICMPTimeout, logger)
+		tracker := NewICMPTracker(DefaultICMPTimeout, logger, flowLogger)
 		defer tracker.Close()
 
 		srcIP := net.ParseIP("192.168.1.1")
@@ -20,7 +20,7 @@ func BenchmarkICMPTracker(b *testing.B) {
 	})
 
 	b.Run("IsValidInbound", func(b *testing.B) {
-		tracker := NewICMPTracker(DefaultICMPTimeout, logger)
+		tracker := NewICMPTracker(DefaultICMPTimeout, logger, flowLogger)
 		defer tracker.Close()
 
 		srcIP := net.ParseIP("192.168.1.1")

client/firewall/uspfilter/conntrack/tcp.go

@@ -8,7 +8,10 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/google/uuid"
+
 	nblog "github.com/netbirdio/netbird/client/firewall/uspfilter/log"
+	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
 )
 
 const (
@@ -39,6 +42,35 @@ const (
 // TCPState represents the state of a TCP connection
 type TCPState int
 
+func (s TCPState) String() string {
+	switch s {
+	case TCPStateNew:
+		return "New"
+	case TCPStateSynSent:
+		return "SYN Sent"
+	case TCPStateSynReceived:
+		return "SYN Received"
+	case TCPStateEstablished:
+		return "Established"
+	case TCPStateFinWait1:
+		return "FIN Wait 1"
+	case TCPStateFinWait2:
+		return "FIN Wait 2"
+	case TCPStateClosing:
+		return "Closing"
+	case TCPStateTimeWait:
+		return "Time Wait"
+	case TCPStateCloseWait:
+		return "Close Wait"
+	case TCPStateLastAck:
+		return "Last ACK"
+	case TCPStateClosed:
+		return "Closed"
+	default:
+		return "Unknown"
+	}
+}
+
 const (
 	TCPStateNew TCPState = iota
 	TCPStateSynSent
@@ -53,19 +85,12 @@ const (
 	TCPStateClosed
 )
 
-// TCPConnKey uniquely identifies a TCP connection
-type TCPConnKey struct {
-	SrcIP   [16]byte
-	DstIP   [16]byte
-	SrcPort uint16
-	DstPort uint16
-}
-
 // TCPConnTrack represents a TCP connection state
 type TCPConnTrack struct {
 	BaseConnTrack
 	State       TCPState
 	established atomic.Bool
+	tombstone   atomic.Bool
 	sync.RWMutex
 }
 
@@ -79,6 +104,16 @@ func (t *TCPConnTrack) SetEstablished(state bool) {
 	t.established.Store(state)
 }
 
+// IsTombstone safely checks if the connection is marked for deletion
+func (t *TCPConnTrack) IsTombstone() bool {
+	return t.tombstone.Load()
+}
+
+// SetTombstone safely marks the connection for deletion
+func (t *TCPConnTrack) SetTombstone() {
+	t.tombstone.Store(true)
+}
+
 // TCPTracker manages TCP connection states
 type TCPTracker struct {
 	logger        *nblog.Logger
@@ -87,68 +122,94 @@ type TCPTracker struct {
 	cleanupTicker *time.Ticker
 	done          chan struct{}
 	timeout       time.Duration
-	ipPool        *PreallocatedIPs
+	flowLogger    nftypes.FlowLogger
 }
 
 // NewTCPTracker creates a new TCP connection tracker
-func NewTCPTracker(timeout time.Duration, logger *nblog.Logger) *TCPTracker {
+func NewTCPTracker(timeout time.Duration, logger *nblog.Logger, flowLogger nftypes.FlowLogger) *TCPTracker {
+	if timeout == 0 {
+		timeout = DefaultTCPTimeout
+	}
+
 	tracker := &TCPTracker{
 		logger:        logger,
 		connections:   make(map[ConnKey]*TCPConnTrack),
 		cleanupTicker: time.NewTicker(TCPCleanupInterval),
 		done:          make(chan struct{}),
 		timeout:       timeout,
-		ipPool:        NewPreallocatedIPs(),
+		flowLogger:    flowLogger,
 	}
 
 	go tracker.cleanupRoutine()
 	return tracker
 }
 
-// TrackOutbound processes an outbound TCP packet and updates connection state
+func (t *TCPTracker) updateIfExists(srcIP net.IP, dstIP net.IP, srcPort uint16, dstPort uint16, flags uint8) (ConnKey, bool) {
-func (t *TCPTracker) TrackOutbound(srcIP net.IP, dstIP net.IP, srcPort uint16, dstPort uint16, flags uint8) {
-	// Create key before lock
 	key := makeConnKey(srcIP, dstIP, srcPort, dstPort)
 
-	t.mutex.Lock()
+	t.mutex.RLock()
 	conn, exists := t.connections[key]
-	if !exists {
+	t.mutex.RUnlock()
-		// Use preallocated IPs
-		srcIPCopy := t.ipPool.Get()
-		dstIPCopy := t.ipPool.Get()
-		copyIP(srcIPCopy, srcIP)
-		copyIP(dstIPCopy, dstIP)
 
-		conn = &TCPConnTrack{
+	if exists {
-			BaseConnTrack: BaseConnTrack{
+		conn.Lock()
-				SourceIP:   srcIPCopy,
+		t.updateState(key, conn, flags, conn.Direction == nftypes.Egress)
-				DestIP:     dstIPCopy,
-				SourcePort: srcPort,
-				DestPort:   dstPort,
-			},
-			State: TCPStateNew,
-		}
 		conn.UpdateLastSeen()
-		conn.established.Store(false)
+		conn.Unlock()
-		t.connections[key] = conn
 
-		t.logger.Trace("New TCP connection: %s:%d -> %s:%d", srcIP, srcPort, dstIP, dstPort)
+		return key, true
 	}
+
+	return key, false
+}
+
+// TrackOutbound records an outbound TCP connection
+func (t *TCPTracker) TrackOutbound(srcIP net.IP, dstIP net.IP, srcPort uint16, dstPort uint16, flags uint8) {
+	if _, exists := t.updateIfExists(dstIP, srcIP, dstPort, srcPort, flags); !exists {
+		// if (inverted direction) conn is not tracked, track this direction
+		t.track(srcIP, dstIP, srcPort, dstPort, flags, nftypes.Egress)
+	}
+}
+
+// TrackInbound processes an inbound TCP packet and updates connection state
+func (t *TCPTracker) TrackInbound(srcIP net.IP, dstIP net.IP, srcPort uint16, dstPort uint16, flags uint8) {
+	t.track(srcIP, dstIP, srcPort, dstPort, flags, nftypes.Ingress)
+}
+
+// track is the common implementation for tracking both inbound and outbound connections
+func (t *TCPTracker) track(srcIP net.IP, dstIP net.IP, srcPort uint16, dstPort uint16, flags uint8, direction nftypes.Direction) {
+	key, exists := t.updateIfExists(srcIP, dstIP, srcPort, dstPort, flags)
+	if exists {
+		return
+	}
+
+	conn := &TCPConnTrack{
+		BaseConnTrack: BaseConnTrack{
+			FlowId:     uuid.New(),
+			Direction:  direction,
+			SourceIP:   key.SrcIP,
+			DestIP:     key.DstIP,
+			SourcePort: srcPort,
+			DestPort:   dstPort,
+		},
+	}
+
+	conn.UpdateLastSeen()
+	conn.established.Store(false)
+	conn.tombstone.Store(false)
+
+	t.logger.Trace("New %s TCP connection: %s", direction, key)
+	t.updateState(key, conn, flags, direction == nftypes.Egress)
+
+	t.mutex.Lock()
+	t.connections[key] = conn
 	t.mutex.Unlock()
 
-	// Lock individual connection for state update
+	t.sendEvent(nftypes.TypeStart, key, conn)
-	conn.Lock()
-	t.updateState(conn, flags, true)
-	conn.Unlock()
-	conn.UpdateLastSeen()
 }
 
 // IsValidInbound checks if an inbound TCP packet matches a tracked connection
 func (t *TCPTracker) IsValidInbound(srcIP net.IP, dstIP net.IP, srcPort uint16, dstPort uint16, flags uint8) bool {
-	if !isValidFlagCombination(flags) {
-		return false
-	}
-
 	key := makeConnKey(dstIP, srcIP, dstPort, srcPort)
 
 	t.mutex.RLock()
@@ -159,21 +220,25 @@ func (t *TCPTracker) IsValidInbound(srcIP net.IP, dstIP net.IP, srcPort uint16,
 		return false
 	}
 
-	// Handle RST packets
+	// Handle RST flag specially - it always causes transition to closed
 	if flags&TCPRst != 0 {
-		conn.Lock()
+		if conn.IsTombstone() {
-		if conn.IsEstablished() || conn.State == TCPStateSynSent || conn.State == TCPStateSynReceived {
-			conn.State = TCPStateClosed
-			conn.SetEstablished(false)
-			conn.Unlock()
 			return true
 		}
+
+		conn.Lock()
+		conn.SetTombstone()
+		conn.State = TCPStateClosed
+		conn.SetEstablished(false)
 		conn.Unlock()
-		return false
+
+		t.logger.Trace("TCP connection reset: %s", key)
+		t.sendEvent(nftypes.TypeEnd, key, conn)
+		return true
 	}
 
 	conn.Lock()
-	t.updateState(conn, flags, false)
+	t.updateState(key, conn, flags, false)
 	conn.UpdateLastSeen()
 	isEstablished := conn.IsEstablished()
 	isValidState := t.isValidStateForFlags(conn.State, flags)
@@ -183,18 +248,15 @@ func (t *TCPTracker) IsValidInbound(srcIP net.IP, dstIP net.IP, srcPort uint16,
 }
 
 // updateState updates the TCP connection state based on flags
-func (t *TCPTracker) updateState(conn *TCPConnTrack, flags uint8, isOutbound bool) {
+func (t *TCPTracker) updateState(key ConnKey, conn *TCPConnTrack, flags uint8, isOutbound bool) {
-	// Handle RST flag specially - it always causes transition to closed
+	state := conn.State
-	if flags&TCPRst != 0 {
+	defer func() {
-		conn.State = TCPStateClosed
+		if state != conn.State {
-		conn.SetEstablished(false)
+			t.logger.Trace("TCP connection %s transitioned from %s to %s", key, state, conn.State)
+		}
+	}()
 
-		t.logger.Trace("TCP connection reset: %s:%d -> %s:%d",
+	switch state {
-			conn.SourceIP, conn.SourcePort, conn.DestIP, conn.DestPort)
-		return
-	}
-
-	switch conn.State {
 	case TCPStateNew:
 		if flags&TCPSyn != 0 && flags&TCPAck == 0 {
 			conn.State = TCPStateSynSent
@@ -241,6 +303,9 @@ func (t *TCPTracker) updateState(conn *TCPConnTrack, flags uint8, isOutbound boo
 	case TCPStateFinWait2:
 		if flags&TCPFin != 0 {
 			conn.State = TCPStateTimeWait
+
+			t.logger.Trace("TCP connection %s completed", key)
+			t.sendEvent(nftypes.TypeEnd, key, conn)
 		}
 
 	case TCPStateClosing:
@@ -248,8 +313,8 @@ func (t *TCPTracker) updateState(conn *TCPConnTrack, flags uint8, isOutbound boo
 			conn.State = TCPStateTimeWait
 			// Keep established = false from previous state
 
-			t.logger.Trace("TCP connection closed (simultaneous) - %s:%d -> %s:%d",
+			t.logger.Trace("TCP connection %s closed (simultaneous)", key)
-				conn.SourceIP, conn.SourcePort, conn.DestIP, conn.DestPort)
+			t.sendEvent(nftypes.TypeEnd, key, conn)
 		}
 
 	case TCPStateCloseWait:
@@ -260,17 +325,12 @@ func (t *TCPTracker) updateState(conn *TCPConnTrack, flags uint8, isOutbound boo
 	case TCPStateLastAck:
 		if flags&TCPAck != 0 {
 			conn.State = TCPStateClosed
+			conn.SetTombstone()
 
-			t.logger.Trace("TCP connection gracefully closed: %s:%d -> %s:%d",
+			// Send close event for gracefully closed connections
-				conn.SourceIP, conn.SourcePort, conn.DestIP, conn.DestPort)
+			t.sendEvent(nftypes.TypeEnd, key, conn)
+			t.logger.Trace("TCP connection %s closed gracefully", key)
 		}
-
-	case TCPStateTimeWait:
-		// Stay in TIME-WAIT for 2MSL before transitioning to closed
-		// This is handled by the cleanup routine
-
-		t.logger.Trace("TCP connection completed - %s:%d -> %s:%d",
-			conn.SourceIP, conn.SourcePort, conn.DestIP, conn.DestPort)
 	}
 }
 
@@ -331,6 +391,12 @@ func (t *TCPTracker) cleanup() {
 	defer t.mutex.Unlock()
 
 	for key, conn := range t.connections {
+		if conn.IsTombstone() {
+			// Clean up tombstoned connections without sending an event
+			delete(t.connections, key)
+			continue
+		}
+
 		var timeout time.Duration
 		switch {
 		case conn.State == TCPStateTimeWait:
@@ -341,14 +407,16 @@ func (t *TCPTracker) cleanup() {
 			timeout = TCPHandshakeTimeout
 		}
 
-		lastSeen := conn.GetLastSeen()
+		if conn.timeoutExceeded(timeout) {
-		if time.Since(lastSeen) > timeout {
 			// Return IPs to pool
-			t.ipPool.Put(conn.SourceIP)
-			t.ipPool.Put(conn.DestIP)
 			delete(t.connections, key)
 
-			t.logger.Trace("Cleaned up TCP connection: %s:%d -> %s:%d", conn.SourceIP, conn.SourcePort, conn.DestIP, conn.DestPort)
+			t.logger.Trace("Cleaned up timed-out TCP connection %s", &key)
+
+			// event already handled by state change
+			if conn.State != TCPStateTimeWait {
+				t.sendEvent(nftypes.TypeEnd, key, conn)
+			}
 		}
 	}
 }
@@ -360,10 +428,6 @@ func (t *TCPTracker) Close() {
 
 	// Clean up all remaining IPs
 	t.mutex.Lock()
-	for _, conn := range t.connections {
-		t.ipPool.Put(conn.SourceIP)
-		t.ipPool.Put(conn.DestIP)
-	}
 	t.connections = nil
 	t.mutex.Unlock()
 }
@@ -381,3 +445,16 @@ func isValidFlagCombination(flags uint8) bool {
 
 	return true
 }
+
+func (t *TCPTracker) sendEvent(typ nftypes.Type, key ConnKey, conn *TCPConnTrack) {
+	t.flowLogger.StoreEvent(nftypes.EventFields{
+		FlowID:     conn.FlowId,
+		Type:       typ,
+		Direction:  conn.Direction,
+		Protocol:   nftypes.TCP,
+		SourceIP:   key.SrcIP,
+		DestIP:     key.DstIP,
+		SourcePort: key.SrcPort,
+		DestPort:   key.DstPort,
+	})
+}

client/firewall/uspfilter/conntrack/tcp_test.go

@@ -9,7 +9,7 @@ import (
 )
 
 func TestTCPStateMachine(t *testing.T) {
-	tracker := NewTCPTracker(DefaultTCPTimeout, logger)
+	tracker := NewTCPTracker(DefaultTCPTimeout, logger, flowLogger)
 	defer tracker.Close()
 
 	srcIP := net.ParseIP("100.64.0.1")
@@ -154,7 +154,7 @@ func TestTCPStateMachine(t *testing.T) {
 			t.Run(tt.name, func(t *testing.T) {
 				t.Helper()
 
-				tracker = NewTCPTracker(DefaultTCPTimeout, logger)
+				tracker = NewTCPTracker(DefaultTCPTimeout, logger, flowLogger)
 				tt.test(t)
 			})
 		}
@@ -162,7 +162,7 @@ func TestTCPStateMachine(t *testing.T) {
 }
 
 func TestRSTHandling(t *testing.T) {
-	tracker := NewTCPTracker(DefaultTCPTimeout, logger)
+	tracker := NewTCPTracker(DefaultTCPTimeout, logger, flowLogger)
 	defer tracker.Close()
 
 	srcIP := net.ParseIP("100.64.0.1")
@@ -233,7 +233,7 @@ func establishConnection(t *testing.T, tracker *TCPTracker, srcIP, dstIP net.IP,
 
 func BenchmarkTCPTracker(b *testing.B) {
 	b.Run("TrackOutbound", func(b *testing.B) {
-		tracker := NewTCPTracker(DefaultTCPTimeout, logger)
+		tracker := NewTCPTracker(DefaultTCPTimeout, logger, flowLogger)
 		defer tracker.Close()
 
 		srcIP := net.ParseIP("192.168.1.1")
@@ -246,7 +246,7 @@ func BenchmarkTCPTracker(b *testing.B) {
 	})
 
 	b.Run("IsValidInbound", func(b *testing.B) {
-		tracker := NewTCPTracker(DefaultTCPTimeout, logger)
+		tracker := NewTCPTracker(DefaultTCPTimeout, logger, flowLogger)
 		defer tracker.Close()
 
 		srcIP := net.ParseIP("192.168.1.1")
@@ -264,7 +264,7 @@ func BenchmarkTCPTracker(b *testing.B) {
 	})
 
 	b.Run("ConcurrentAccess", func(b *testing.B) {
-		tracker := NewTCPTracker(DefaultTCPTimeout, logger)
+		tracker := NewTCPTracker(DefaultTCPTimeout, logger, flowLogger)
 		defer tracker.Close()
 
 		srcIP := net.ParseIP("192.168.1.1")
@@ -287,7 +287,7 @@ func BenchmarkTCPTracker(b *testing.B) {
 // Benchmark connection cleanup
 func BenchmarkCleanup(b *testing.B) {
 	b.Run("TCPCleanup", func(b *testing.B) {
-		tracker := NewTCPTracker(100*time.Millisecond, logger) // Short timeout for testing
+		tracker := NewTCPTracker(100*time.Millisecond, logger, flowLogger) // Short timeout for testing
 		defer tracker.Close()
 
 		// Pre-populate with expired connections

client/firewall/uspfilter/conntrack/udp.go

@@ -5,7 +5,10 @@ import (
 	"sync"
 	"time"
 
+	"github.com/google/uuid"
+
 	nblog "github.com/netbirdio/netbird/client/firewall/uspfilter/log"
+	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
 )
 
 const (
@@ -28,11 +31,11 @@ type UDPTracker struct {
 	cleanupTicker *time.Ticker
 	mutex         sync.RWMutex
 	done          chan struct{}
-	ipPool        *PreallocatedIPs
+	flowLogger    nftypes.FlowLogger
 }
 
 // NewUDPTracker creates a new UDP connection tracker
-func NewUDPTracker(timeout time.Duration, logger *nblog.Logger) *UDPTracker {
+func NewUDPTracker(timeout time.Duration, logger *nblog.Logger, flowLogger nftypes.FlowLogger) *UDPTracker {
 	if timeout == 0 {
 		timeout = DefaultUDPTimeout
 	}
@@ -43,7 +46,7 @@ func NewUDPTracker(timeout time.Duration, logger *nblog.Logger) *UDPTracker {
 		timeout:       timeout,
 		cleanupTicker: time.NewTicker(UDPCleanupInterval),
 		done:          make(chan struct{}),
-		ipPool:        NewPreallocatedIPs(),
+		flowLogger:    flowLogger,
 	}
 
 	go tracker.cleanupRoutine()
@@ -52,32 +55,57 @@ func NewUDPTracker(timeout time.Duration, logger *nblog.Logger) *UDPTracker {
 
 // TrackOutbound records an outbound UDP connection
 func (t *UDPTracker) TrackOutbound(srcIP net.IP, dstIP net.IP, srcPort uint16, dstPort uint16) {
+	if _, exists := t.updateIfExists(dstIP, srcIP, dstPort, srcPort); !exists {
+		// if (inverted direction) conn is not tracked, track this direction
+		t.track(srcIP, dstIP, srcPort, dstPort, nftypes.Egress)
+	}
+}
+
+// TrackInbound records an inbound UDP connection
+func (t *UDPTracker) TrackInbound(srcIP net.IP, dstIP net.IP, srcPort uint16, dstPort uint16) {
+	t.track(srcIP, dstIP, srcPort, dstPort, nftypes.Ingress)
+}
+
+func (t *UDPTracker) updateIfExists(srcIP net.IP, dstIP net.IP, srcPort uint16, dstPort uint16) (ConnKey, bool) {
 	key := makeConnKey(srcIP, dstIP, srcPort, dstPort)
 
-	t.mutex.Lock()
+	t.mutex.RLock()
 	conn, exists := t.connections[key]
-	if !exists {
+	t.mutex.RUnlock()
-		srcIPCopy := t.ipPool.Get()
-		dstIPCopy := t.ipPool.Get()
-		copyIP(srcIPCopy, srcIP)
-		copyIP(dstIPCopy, dstIP)
 
-		conn = &UDPConnTrack{
+	if exists {
-			BaseConnTrack: BaseConnTrack{
-				SourceIP:   srcIPCopy,
-				DestIP:     dstIPCopy,
-				SourcePort: srcPort,
-				DestPort:   dstPort,
-			},
-		}
 		conn.UpdateLastSeen()
-		t.connections[key] = conn
+		return key, true
-
-		t.logger.Trace("New UDP connection: %v", conn)
 	}
+
+	return key, false
+}
+
+// track is the common implementation for tracking both inbound and outbound connections
+func (t *UDPTracker) track(srcIP net.IP, dstIP net.IP, srcPort uint16, dstPort uint16, direction nftypes.Direction) {
+	key, exists := t.updateIfExists(srcIP, dstIP, srcPort, dstPort)
+	if exists {
+		return
+	}
+
+	conn := &UDPConnTrack{
+		BaseConnTrack: BaseConnTrack{
+			FlowId:     uuid.New(),
+			Direction:  direction,
+			SourceIP:   key.SrcIP,
+			DestIP:     key.DstIP,
+			SourcePort: srcPort,
+			DestPort:   dstPort,
+		},
+	}
+	conn.UpdateLastSeen()
+
+	t.mutex.Lock()
+	t.connections[key] = conn
 	t.mutex.Unlock()
 
-	conn.UpdateLastSeen()
+	t.logger.Trace("New %s UDP connection: %s", direction, key)
+	t.sendEvent(nftypes.TypeStart, key, conn)
 }
 
 // IsValidInbound checks if an inbound packet matches a tracked connection
@@ -88,18 +116,13 @@ func (t *UDPTracker) IsValidInbound(srcIP net.IP, dstIP net.IP, srcPort uint16,
 	conn, exists := t.connections[key]
 	t.mutex.RUnlock()
 
-	if !exists {
+	if !exists || conn.timeoutExceeded(t.timeout) {
 		return false
 	}
 
-	if conn.timeoutExceeded(t.timeout) {
+	conn.UpdateLastSeen()
-		return false
-	}
 
-	return ValidateIPs(MakeIPAddr(srcIP), conn.DestIP) &&
+	return true
-		ValidateIPs(MakeIPAddr(dstIP), conn.SourceIP) &&
-		conn.DestPort == srcPort &&
-		conn.SourcePort == dstPort
 }
 
 // cleanupRoutine periodically removes stale connections
@@ -120,11 +143,10 @@ func (t *UDPTracker) cleanup() {
 
 	for key, conn := range t.connections {
 		if conn.timeoutExceeded(t.timeout) {
-			t.ipPool.Put(conn.SourceIP)
-			t.ipPool.Put(conn.DestIP)
 			delete(t.connections, key)
 
-			t.logger.Trace("Removed UDP connection %v (timeout)", conn)
+			t.logger.Trace("Removed UDP connection %s (timeout)", key)
+			t.sendEvent(nftypes.TypeEnd, key, conn)
 		}
 	}
 }
@@ -135,10 +157,6 @@ func (t *UDPTracker) Close() {
 	close(t.done)
 
 	t.mutex.Lock()
-	for _, conn := range t.connections {
-		t.ipPool.Put(conn.SourceIP)
-		t.ipPool.Put(conn.DestIP)
-	}
 	t.connections = nil
 	t.mutex.Unlock()
 }
@@ -150,14 +168,23 @@ func (t *UDPTracker) GetConnection(srcIP net.IP, srcPort uint16, dstIP net.IP, d
 
 	key := makeConnKey(srcIP, dstIP, srcPort, dstPort)
 	conn, exists := t.connections[key]
-	if !exists {
+	return conn, exists
-		return nil, false
-	}
-
-	return conn, true
 }
 
 // Timeout returns the configured timeout duration for the tracker
 func (t *UDPTracker) Timeout() time.Duration {
 	return t.timeout
 }
+
+func (t *UDPTracker) sendEvent(typ nftypes.Type, key ConnKey, conn *UDPConnTrack) {
+	t.flowLogger.StoreEvent(nftypes.EventFields{
+		FlowID:     conn.FlowId,
+		Type:       typ,
+		Direction:  conn.Direction,
+		Protocol:   nftypes.UDP,
+		SourceIP:   key.SrcIP,
+		DestIP:     key.DstIP,
+		SourcePort: key.SrcPort,
+		DestPort:   key.DstPort,
+	})
+}

client/firewall/uspfilter/conntrack/udp_test.go

@@ -2,6 +2,7 @@ package conntrack
 
 import (
 	"net"
+	"net/netip"
 	"testing"
 	"time"
 
@@ -29,7 +30,7 @@ func TestNewUDPTracker(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			tracker := NewUDPTracker(tt.timeout, logger)
+			tracker := NewUDPTracker(tt.timeout, logger, flowLogger)
 			assert.NotNil(t, tracker)
 			assert.Equal(t, tt.wantTimeout, tracker.timeout)
 			assert.NotNil(t, tracker.connections)
@@ -40,29 +41,29 @@ func TestNewUDPTracker(t *testing.T) {
 }
 
 func TestUDPTracker_TrackOutbound(t *testing.T) {
-	tracker := NewUDPTracker(DefaultUDPTimeout, logger)
+	tracker := NewUDPTracker(DefaultUDPTimeout, logger, flowLogger)
 	defer tracker.Close()
 
-	srcIP := net.ParseIP("192.168.1.2")
+	srcIP := netip.MustParseAddr("192.168.1.2")
-	dstIP := net.ParseIP("192.168.1.3")
+	dstIP := netip.MustParseAddr("192.168.1.3")
 	srcPort := uint16(12345)
 	dstPort := uint16(53)
 
-	tracker.TrackOutbound(srcIP, dstIP, srcPort, dstPort)
+	tracker.TrackOutbound(srcIP.AsSlice(), dstIP.AsSlice(), srcPort, dstPort)
 
 	// Verify connection was tracked
-	key := makeConnKey(srcIP, dstIP, srcPort, dstPort)
+	key := makeConnKey(srcIP.AsSlice(), dstIP.AsSlice(), srcPort, dstPort)
 	conn, exists := tracker.connections[key]
 	require.True(t, exists)
-	assert.True(t, conn.SourceIP.Equal(srcIP))
+	assert.True(t, conn.SourceIP.Compare(srcIP) == 0)
-	assert.True(t, conn.DestIP.Equal(dstIP))
+	assert.True(t, conn.DestIP.Compare(dstIP) == 0)
 	assert.Equal(t, srcPort, conn.SourcePort)
 	assert.Equal(t, dstPort, conn.DestPort)
 	assert.WithinDuration(t, time.Now(), conn.GetLastSeen(), 1*time.Second)
 }
 
 func TestUDPTracker_IsValidInbound(t *testing.T) {
-	tracker := NewUDPTracker(1*time.Second, logger)
+	tracker := NewUDPTracker(1*time.Second, logger, flowLogger)
 	defer tracker.Close()
 
 	srcIP := net.ParseIP("192.168.1.2")
@@ -160,8 +161,8 @@ func TestUDPTracker_Cleanup(t *testing.T) {
 		timeout:       timeout,
 		cleanupTicker: time.NewTicker(cleanupInterval),
 		done:          make(chan struct{}),
-		ipPool:        NewPreallocatedIPs(),
 		logger:        logger,
+		flowLogger:    flowLogger,
 	}
 
 	// Start cleanup routine
@@ -211,7 +212,7 @@ func TestUDPTracker_Cleanup(t *testing.T) {
 
 func BenchmarkUDPTracker(b *testing.B) {
 	b.Run("TrackOutbound", func(b *testing.B) {
-		tracker := NewUDPTracker(DefaultUDPTimeout, logger)
+		tracker := NewUDPTracker(DefaultUDPTimeout, logger, flowLogger)
 		defer tracker.Close()
 
 		srcIP := net.ParseIP("192.168.1.1")
@@ -224,7 +225,7 @@ func BenchmarkUDPTracker(b *testing.B) {
 	})
 
 	b.Run("IsValidInbound", func(b *testing.B) {
-		tracker := NewUDPTracker(DefaultUDPTimeout, logger)
+		tracker := NewUDPTracker(DefaultUDPTimeout, logger, flowLogger)
 		defer tracker.Close()
 
 		srcIP := net.ParseIP("192.168.1.1")

client/firewall/uspfilter/forwarder/forwarder.go

@@ -18,6 +18,7 @@ import (
 
 	"github.com/netbirdio/netbird/client/firewall/uspfilter/common"
 	nblog "github.com/netbirdio/netbird/client/firewall/uspfilter/log"
+	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
 )
 
 const (
@@ -29,6 +30,7 @@ const (
 
 type Forwarder struct {
 	logger       *nblog.Logger
+	flowLogger   nftypes.FlowLogger
 	stack        *stack.Stack
 	endpoint     *endpoint
 	udpForwarder *udpForwarder
@@ -38,7 +40,7 @@ type Forwarder struct {
 	netstack     bool
 }
 
-func New(iface common.IFaceMapper, logger *nblog.Logger, netstack bool) (*Forwarder, error) {
+func New(iface common.IFaceMapper, logger *nblog.Logger, flowLogger nftypes.FlowLogger, netstack bool) (*Forwarder, error) {
 	s := stack.New(stack.Options{
 		NetworkProtocols: []stack.NetworkProtocolFactory{ipv4.NewProtocol},
 		TransportProtocols: []stack.TransportProtocolFactory{
@@ -102,9 +104,10 @@ func New(iface common.IFaceMapper, logger *nblog.Logger, netstack bool) (*Forwar
 	ctx, cancel := context.WithCancel(context.Background())
 	f := &Forwarder{
 		logger:       logger,
+		flowLogger:   flowLogger,
 		stack:        s,
 		endpoint:     endpoint,
-		udpForwarder: newUDPForwarder(mtu, logger),
+		udpForwarder: newUDPForwarder(mtu, logger, flowLogger),
 		ctx:          ctx,
 		cancel:       cancel,
 		netstack:     netstack,

client/firewall/uspfilter/forwarder/icmp.go

@@ -3,14 +3,21 @@ package forwarder
 import (
 	"context"
 	"net"
+	"net/netip"
 	"time"
 
+	"github.com/google/uuid"
 	"gvisor.dev/gvisor/pkg/tcpip/header"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
+
+	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
 )
 
 // handleICMP handles ICMP packets from the network stack
 func (f *Forwarder) handleICMP(id stack.TransportEndpointID, pkt stack.PacketBufferPtr) bool {
+	flowID := uuid.New()
+	f.sendICMPEvent(nftypes.TypeStart, flowID, id)
+
 	ctx, cancel := context.WithTimeout(f.ctx, 5*time.Second)
 	defer cancel()
 
@@ -20,6 +27,8 @@ func (f *Forwarder) handleICMP(id stack.TransportEndpointID, pkt stack.PacketBuf
 	if err != nil {
 		f.logger.Error("Failed to create ICMP socket for %v: %v", id, err)
 
+		f.sendICMPEvent(nftypes.TypeEnd, flowID, id)
+
 		// This will make netstack reply on behalf of the original destination, that's ok for now
 		return false
 	}
@@ -27,6 +36,8 @@ func (f *Forwarder) handleICMP(id stack.TransportEndpointID, pkt stack.PacketBuf
 		if err := conn.Close(); err != nil {
 			f.logger.Debug("Failed to close ICMP socket: %v", err)
 		}
+
+		f.sendICMPEvent(nftypes.TypeEnd, flowID, id)
 	}()
 
 	dstIP := f.determineDialAddr(id.LocalAddress)
@@ -101,9 +112,25 @@ func (f *Forwarder) handleEchoResponse(icmpHdr header.ICMPv4, payload []byte, ds
 
 	if err := f.InjectIncomingPacket(fullPacket); err != nil {
 		f.logger.Error("Failed to inject ICMP response: %v", err)
+
 		return true
 	}
 
 	f.logger.Trace("Forwarded ICMP echo reply for %v", id)
 	return true
 }
+
+// sendICMPEvent stores flow events for ICMP packets
+func (f *Forwarder) sendICMPEvent(typ nftypes.Type, flowID uuid.UUID, id stack.TransportEndpointID) {
+	f.flowLogger.StoreEvent(nftypes.EventFields{
+		FlowID:    flowID,
+		Type:      typ,
+		Direction: nftypes.Ingress,
+		Protocol:  1,
+		// TODO: handle ipv6
+		SourceIP:   netip.AddrFrom4(id.LocalAddress.As4()),
+		DestIP:     netip.AddrFrom4(id.RemoteAddress.As4()),
+		SourcePort: id.LocalPort,
+		DestPort:   id.RemotePort,
+	})
+}

client/firewall/uspfilter/forwarder/tcp.go

@@ -5,18 +5,25 @@ import (
 	"fmt"
 	"io"
 	"net"
+	"net/netip"
 
+	"github.com/google/uuid"
 	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
 	"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
 	"gvisor.dev/gvisor/pkg/waiter"
+
+	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
 )
 
 // handleTCP is called by the TCP forwarder for new connections.
 func (f *Forwarder) handleTCP(r *tcp.ForwarderRequest) {
 	id := r.ID()
 
+	flowID := uuid.New()
+	f.sendTCPEvent(nftypes.TypeStart, flowID, id)
+
 	dialAddr := fmt.Sprintf("%s:%d", f.determineDialAddr(id.LocalAddress), id.LocalPort)
 
 	outConn, err := (&net.Dialer{}).DialContext(f.ctx, "tcp", dialAddr)
@@ -46,10 +53,10 @@ func (f *Forwarder) handleTCP(r *tcp.ForwarderRequest) {
 
 	f.logger.Trace("forwarder: established TCP connection %v", id)
 
-	go f.proxyTCP(id, inConn, outConn, ep)
+	go f.proxyTCP(id, inConn, outConn, ep, flowID)
 }
 
-func (f *Forwarder) proxyTCP(id stack.TransportEndpointID, inConn *gonet.TCPConn, outConn net.Conn, ep tcpip.Endpoint) {
+func (f *Forwarder) proxyTCP(id stack.TransportEndpointID, inConn *gonet.TCPConn, outConn net.Conn, ep tcpip.Endpoint, flowID uuid.UUID) {
 	defer func() {
 		if err := inConn.Close(); err != nil {
 			f.logger.Debug("forwarder: inConn close error: %v", err)
@@ -58,6 +65,8 @@ func (f *Forwarder) proxyTCP(id stack.TransportEndpointID, inConn *gonet.TCPConn
 			f.logger.Debug("forwarder: outConn close error: %v", err)
 		}
 		ep.Close()
+
+		f.sendTCPEvent(nftypes.TypeEnd, flowID, id)
 	}()
 
 	// Create context for managing the proxy goroutines
@@ -88,3 +97,18 @@ func (f *Forwarder) proxyTCP(id stack.TransportEndpointID, inConn *gonet.TCPConn
 		return
 	}
 }
+
+func (f *Forwarder) sendTCPEvent(typ nftypes.Type, flowID uuid.UUID, id stack.TransportEndpointID) {
+
+	f.flowLogger.StoreEvent(nftypes.EventFields{
+		FlowID:    flowID,
+		Type:      typ,
+		Direction: nftypes.Ingress,
+		Protocol:  6,
+		// TODO: handle ipv6
+		SourceIP:   netip.AddrFrom4(id.LocalAddress.As4()),
+		DestIP:     netip.AddrFrom4(id.RemoteAddress.As4()),
+		SourcePort: id.LocalPort,
+		DestPort:   id.RemotePort,
+	})
+}

client/firewall/uspfilter/forwarder/udp.go

@@ -5,10 +5,12 @@ import (
 	"errors"
 	"fmt"
 	"net"
+	"net/netip"
 	"sync"
 	"sync/atomic"
 	"time"
 
+	"github.com/google/uuid"
 	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
@@ -16,6 +18,7 @@ import (
 	"gvisor.dev/gvisor/pkg/waiter"
 
 	nblog "github.com/netbirdio/netbird/client/firewall/uspfilter/log"
+	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
 )
 
 const (
@@ -28,15 +31,17 @@ type udpPacketConn struct {
 	lastSeen atomic.Int64
 	cancel   context.CancelFunc
 	ep       tcpip.Endpoint
+	flowID   uuid.UUID
 }
 
 type udpForwarder struct {
 	sync.RWMutex
-	logger  *nblog.Logger
+	logger     *nblog.Logger
-	conns   map[stack.TransportEndpointID]*udpPacketConn
+	flowLogger nftypes.FlowLogger
-	bufPool sync.Pool
+	conns      map[stack.TransportEndpointID]*udpPacketConn
-	ctx     context.Context
+	bufPool    sync.Pool
-	cancel  context.CancelFunc
+	ctx        context.Context
+	cancel     context.CancelFunc
 }
 
 type idleConn struct {
@@ -44,13 +49,14 @@ type idleConn struct {
 	conn *udpPacketConn
 }
 
-func newUDPForwarder(mtu int, logger *nblog.Logger) *udpForwarder {
+func newUDPForwarder(mtu int, logger *nblog.Logger, flowLogger nftypes.FlowLogger) *udpForwarder {
 	ctx, cancel := context.WithCancel(context.Background())
 	f := &udpForwarder{
-		logger: logger,
+		logger:     logger,
-		conns:  make(map[stack.TransportEndpointID]*udpPacketConn),
+		flowLogger: flowLogger,
-		ctx:    ctx,
+		conns:      make(map[stack.TransportEndpointID]*udpPacketConn),
-		cancel: cancel,
+		ctx:        ctx,
+		cancel:     cancel,
 		bufPool: sync.Pool{
 			New: func() any {
 				b := make([]byte, mtu)
@@ -83,6 +89,21 @@ func (f *udpForwarder) Stop() {
 	}
 }
 
+// sendUDPEvent stores flow events for UDP connections
+func (f *udpForwarder) sendUDPEvent(typ nftypes.Type, flowID uuid.UUID, id stack.TransportEndpointID) {
+	f.flowLogger.StoreEvent(nftypes.EventFields{
+		FlowID:    flowID,
+		Type:      typ,
+		Direction: nftypes.Ingress,
+		Protocol:  17,
+		// TODO: handle ipv6
+		SourceIP:   netip.AddrFrom4(id.LocalAddress.As4()),
+		DestIP:     netip.AddrFrom4(id.RemoteAddress.As4()),
+		SourcePort: id.LocalPort,
+		DestPort:   id.RemotePort,
+	})
+}
+
 // cleanup periodically removes idle UDP connections
 func (f *udpForwarder) cleanup() {
 	ticker := time.NewTicker(time.Minute)
@@ -119,6 +140,8 @@ func (f *udpForwarder) cleanup() {
 				f.Unlock()
 
 				f.logger.Trace("forwarder: cleaned up idle UDP connection %v", idle.id)
+
+				f.sendUDPEvent(nftypes.TypeEnd, idle.conn.flowID, idle.id)
 			}
 		}
 	}
@@ -141,10 +164,14 @@ func (f *Forwarder) handleUDP(r *udp.ForwarderRequest) {
 		return
 	}
 
+	flowID := uuid.New()
+	f.sendUDPEvent(nftypes.TypeStart, flowID, id)
+
 	dstAddr := fmt.Sprintf("%s:%d", f.determineDialAddr(id.LocalAddress), id.LocalPort)
 	outConn, err := (&net.Dialer{}).DialContext(f.ctx, "udp", dstAddr)
 	if err != nil {
 		f.logger.Debug("forwarder: UDP dial error for %v: %v", id, err)
+		f.sendUDPEvent(nftypes.TypeEnd, flowID, id)
 		// TODO: Send ICMP error message
 		return
 	}
@@ -157,6 +184,7 @@ func (f *Forwarder) handleUDP(r *udp.ForwarderRequest) {
 		if err := outConn.Close(); err != nil {
 			f.logger.Debug("forwarder: UDP outConn close error for %v: %v", id, err)
 		}
+		f.sendUDPEvent(nftypes.TypeEnd, flowID, id)
 		return
 	}
 
@@ -168,6 +196,7 @@ func (f *Forwarder) handleUDP(r *udp.ForwarderRequest) {
 		outConn: outConn,
 		cancel:  connCancel,
 		ep:      ep,
+		flowID:  flowID,
 	}
 	pConn.updateLastSeen()
 
@@ -182,6 +211,8 @@ func (f *Forwarder) handleUDP(r *udp.ForwarderRequest) {
 		if err := outConn.Close(); err != nil {
 			f.logger.Debug("forwarder: UDP outConn close error for %v: %v", id, err)
 		}
+
+		f.sendUDPEvent(nftypes.TypeEnd, flowID, id)
 		return
 	}
 	f.udpForwarder.conns[id] = pConn
@@ -206,6 +237,8 @@ func (f *Forwarder) proxyUDP(ctx context.Context, pConn *udpPacketConn, id stack
 		f.udpForwarder.Lock()
 		delete(f.udpForwarder.conns, id)
 		f.udpForwarder.Unlock()
+
+		f.sendUDPEvent(nftypes.TypeEnd, pConn.flowID, id)
 	}()
 
 	errChan := make(chan error, 2)
@@ -231,6 +264,21 @@ func (f *Forwarder) proxyUDP(ctx context.Context, pConn *udpPacketConn, id stack
 	}
 }
 
+// sendUDPEvent stores flow events for UDP connections, mirrors the TCP version
+func (f *Forwarder) sendUDPEvent(typ nftypes.Type, flowID uuid.UUID, id stack.TransportEndpointID) {
+	f.flowLogger.StoreEvent(nftypes.EventFields{
+		FlowID:    flowID,
+		Type:      typ,
+		Direction: nftypes.Ingress,
+		Protocol:  17, // UDP protocol number
+		// TODO: handle ipv6
+		SourceIP:   netip.AddrFrom4(id.LocalAddress.As4()),
+		DestIP:     netip.AddrFrom4(id.RemoteAddress.As4()),
+		SourcePort: id.LocalPort,
+		DestPort:   id.RemotePort,
+	})
+}
+
 func (c *udpPacketConn) updateLastSeen() {
 	c.lastSeen.Store(time.Now().UnixNano())
 }

client/firewall/uspfilter/log/log.go

@@ -1,4 +1,4 @@
-// Package logger provides a high-performance, non-blocking logger for userspace networking
+// Package log provides a high-performance, non-blocking logger for userspace networking
 package log
 
 import (
@@ -13,13 +13,12 @@ import (
 )
 
 const (
-	maxBatchSize         = 1024 * 16  // 16KB max batch size
+	maxBatchSize         = 1024 * 16
-	maxMessageSize       = 1024 * 2   // 2KB per message
+	maxMessageSize       = 1024 * 2
-	bufferSize           = 1024 * 256 // 256KB ring buffer
 	defaultFlushInterval = 2 * time.Second
+	logChannelSize       = 1000
 )
 
-// Level represents log severity
 type Level uint32
 
 const (
@@ -42,32 +41,37 @@ var levelStrings = map[Level]string{
 	LevelTrace: "TRAC",
 }
 
-// Logger is a high-performance, non-blocking logger
+type logMessage struct {
-type Logger struct {
+	level  Level
-	output    io.Writer
+	format string
-	level     atomic.Uint32
+	args   []any
-	buffer    *ringBuffer
-	shutdown  chan struct{}
-	closeOnce sync.Once
-	wg        sync.WaitGroup
-
-	// Reusable buffer pool for formatting messages
-	bufPool sync.Pool
 }
 
+// Logger is a high-performance, non-blocking logger
+type Logger struct {
+	output     io.Writer
+	level      atomic.Uint32
+	msgChannel chan logMessage
+	shutdown   chan struct{}
+	closeOnce  sync.Once
+	wg         sync.WaitGroup
+	bufPool    sync.Pool
+}
+
+// NewFromLogrus creates a new Logger that writes to the same output as the given logrus logger
 func NewFromLogrus(logrusLogger *log.Logger) *Logger {
 	l := &Logger{
-		output:   logrusLogger.Out,
+		output:     logrusLogger.Out,
-		buffer:   newRingBuffer(bufferSize),
+		msgChannel: make(chan logMessage, logChannelSize),
-		shutdown: make(chan struct{}),
+		shutdown:   make(chan struct{}),
 		bufPool: sync.Pool{
-			New: func() interface{} {
+			New: func() any {
-				// Pre-allocate buffer for message formatting
 				b := make([]byte, 0, maxMessageSize)
 				return &b
 			},
 		},
 	}
+
 	logrusLevel := logrusLogger.GetLevel()
 	l.level.Store(uint32(logrusLevel))
 	level := levelStrings[Level(logrusLevel)]
@@ -79,97 +83,149 @@ func NewFromLogrus(logrusLogger *log.Logger) *Logger {
 	return l
 }
 
+// SetLevel sets the logging level
 func (l *Logger) SetLevel(level Level) {
 	l.level.Store(uint32(level))
-
 	log.Debugf("Set uspfilter logger loglevel to %v", levelStrings[level])
 }
 
-func (l *Logger) formatMessage(buf *[]byte, level Level, format string, args ...interface{}) {
+func (l *Logger) log(level Level, format string, args ...any) {
-	*buf = (*buf)[:0]
+	select {
-
+	case l.msgChannel <- logMessage{level: level, format: format, args: args}:
-	// Timestamp
+	default:
-	*buf = time.Now().AppendFormat(*buf, "2006-01-02T15:04:05-07:00")
-	*buf = append(*buf, ' ')
-
-	// Level
-	*buf = append(*buf, levelStrings[level]...)
-	*buf = append(*buf, ' ')
-
-	// Message
-	if len(args) > 0 {
-		*buf = append(*buf, fmt.Sprintf(format, args...)...)
-	} else {
-		*buf = append(*buf, format...)
 	}
-
-	*buf = append(*buf, '\n')
 }
 
-func (l *Logger) log(level Level, format string, args ...interface{}) {
+// Error logs a message at error level
-	bufp := l.bufPool.Get().(*[]byte)
+func (l *Logger) Error(format string, args ...any) {
-	l.formatMessage(bufp, level, format, args...)
-
-	if len(*bufp) > maxMessageSize {
-		*bufp = (*bufp)[:maxMessageSize]
-	}
-	_, _ = l.buffer.Write(*bufp)
-
-	l.bufPool.Put(bufp)
-}
-
-func (l *Logger) Error(format string, args ...interface{}) {
 	if l.level.Load() >= uint32(LevelError) {
 		l.log(LevelError, format, args...)
 	}
 }
 
-func (l *Logger) Warn(format string, args ...interface{}) {
+// Warn logs a message at warning level
+func (l *Logger) Warn(format string, args ...any) {
 	if l.level.Load() >= uint32(LevelWarn) {
 		l.log(LevelWarn, format, args...)
 	}
 }
 
-func (l *Logger) Info(format string, args ...interface{}) {
+// Info logs a message at info level
+func (l *Logger) Info(format string, args ...any) {
 	if l.level.Load() >= uint32(LevelInfo) {
 		l.log(LevelInfo, format, args...)
 	}
 }
 
-func (l *Logger) Debug(format string, args ...interface{}) {
+// Debug logs a message at debug level
+func (l *Logger) Debug(format string, args ...any) {
 	if l.level.Load() >= uint32(LevelDebug) {
 		l.log(LevelDebug, format, args...)
 	}
 }
 
-func (l *Logger) Trace(format string, args ...interface{}) {
+// Trace logs a message at trace level
+func (l *Logger) Trace(format string, args ...any) {
 	if l.level.Load() >= uint32(LevelTrace) {
 		l.log(LevelTrace, format, args...)
 	}
 }
 
-// worker periodically flushes the buffer
+func (l *Logger) formatMessage(buf *[]byte, level Level, format string, args ...any) {
+	*buf = (*buf)[:0]
+	*buf = time.Now().AppendFormat(*buf, "2006-01-02T15:04:05.000-07:00")
+	*buf = append(*buf, ' ')
+	*buf = append(*buf, levelStrings[level]...)
+	*buf = append(*buf, ' ')
+
+	var msg string
+	if len(args) > 0 {
+		msg = fmt.Sprintf(format, args...)
+	} else {
+		msg = format
+	}
+	*buf = append(*buf, msg...)
+	*buf = append(*buf, '\n')
+
+	if len(*buf) > maxMessageSize {
+		*buf = (*buf)[:maxMessageSize]
+	}
+}
+
+// processMessage handles a single log message and adds it to the buffer
+func (l *Logger) processMessage(msg logMessage, buffer *[]byte) {
+	bufp := l.bufPool.Get().(*[]byte)
+	defer l.bufPool.Put(bufp)
+
+	l.formatMessage(bufp, msg.level, msg.format, msg.args...)
+
+	if len(*buffer)+len(*bufp) > maxBatchSize {
+		_, _ = l.output.Write(*buffer)
+		*buffer = (*buffer)[:0]
+	}
+	*buffer = append(*buffer, *bufp...)
+}
+
+// flushBuffer writes the accumulated buffer to output
+func (l *Logger) flushBuffer(buffer *[]byte) {
+	if len(*buffer) > 0 {
+		_, _ = l.output.Write(*buffer)
+		*buffer = (*buffer)[:0]
+	}
+}
+
+// processBatch processes as many messages as possible without blocking
+func (l *Logger) processBatch(buffer *[]byte) {
+	for len(*buffer) < maxBatchSize {
+		select {
+		case msg := <-l.msgChannel:
+			l.processMessage(msg, buffer)
+		default:
+			return
+		}
+	}
+}
+
+// handleShutdown manages the graceful shutdown sequence with timeout
+func (l *Logger) handleShutdown(buffer *[]byte) {
+	ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
+	defer cancel()
+
+	for {
+		select {
+		case msg := <-l.msgChannel:
+			l.processMessage(msg, buffer)
+		case <-ctx.Done():
+			l.flushBuffer(buffer)
+			return
+		}
+
+		if len(l.msgChannel) == 0 {
+			l.flushBuffer(buffer)
+			return
+		}
+	}
+}
+
+// worker is the main goroutine that processes log messages
 func (l *Logger) worker() {
 	defer l.wg.Done()
 
 	ticker := time.NewTicker(defaultFlushInterval)
 	defer ticker.Stop()
 
-	buf := make([]byte, 0, maxBatchSize)
+	buffer := make([]byte, 0, maxBatchSize)
 
 	for {
 		select {
 		case <-l.shutdown:
+			l.handleShutdown(&buffer)
 			return
 		case <-ticker.C:
-			// Read accumulated messages
+			l.flushBuffer(&buffer)
-			n, _ := l.buffer.Read(buf[:cap(buf)])
+		case msg := <-l.msgChannel:
-			if n == 0 {
+			l.processMessage(msg, &buffer)
-				continue
+			l.processBatch(&buffer)
-			}
-
-			// Write batch
-			_, _ = l.output.Write(buf[:n])
 		}
 	}
 }

client/firewall/uspfilter/log/log_test.go

@@ -0,0 +1,121 @@
+package log_test
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/client/firewall/uspfilter/log"
+)
+
+type discard struct{}
+
+func (d *discard) Write(p []byte) (n int, err error) {
+	return len(p), nil
+}
+
+func BenchmarkLogger(b *testing.B) {
+	simpleMessage := "Connection established"
+
+	conntrackMessage := "TCP connection %s:%d -> %s:%d state changed to %d"
+	srcIP := "192.168.1.1"
+	srcPort := uint16(12345)
+	dstIP := "10.0.0.1"
+	dstPort := uint16(443)
+	state := 4 // TCPStateEstablished
+
+	complexMessage := "Packet inspection result: protocol=%s, direction=%s, flags=0x%x, sequence=%d, acknowledged=%d, payload_size=%d, fragmented=%v, connection_id=%s"
+	protocol := "TCP"
+	direction := "outbound"
+	flags := uint16(0x18) // ACK + PSH
+	sequence := uint32(123456789)
+	acknowledged := uint32(987654321)
+	payloadSize := 1460
+	fragmented := false
+	connID := "f7a12b3e-c456-7890-d123-456789abcdef"
+
+	b.Run("SimpleMessage", func(b *testing.B) {
+		logger := createTestLogger()
+		defer cleanupLogger(logger)
+
+		b.ResetTimer()
+		for i := 0; i < b.N; i++ {
+			logger.Trace(simpleMessage)
+		}
+	})
+
+	b.Run("ConntrackMessage", func(b *testing.B) {
+		logger := createTestLogger()
+		defer cleanupLogger(logger)
+
+		b.ResetTimer()
+		for i := 0; i < b.N; i++ {
+			logger.Trace(conntrackMessage, srcIP, srcPort, dstIP, dstPort, state)
+		}
+	})
+
+	b.Run("ComplexMessage", func(b *testing.B) {
+		logger := createTestLogger()
+		defer cleanupLogger(logger)
+
+		b.ResetTimer()
+		for i := 0; i < b.N; i++ {
+			logger.Trace(complexMessage, protocol, direction, flags, sequence, acknowledged, payloadSize, fragmented, connID)
+		}
+	})
+}
+
+// BenchmarkLoggerParallel tests the logger under concurrent load
+func BenchmarkLoggerParallel(b *testing.B) {
+	logger := createTestLogger()
+	defer cleanupLogger(logger)
+
+	conntrackMessage := "TCP connection %s:%d -> %s:%d state changed to %d"
+	srcIP := "192.168.1.1"
+	srcPort := uint16(12345)
+	dstIP := "10.0.0.1"
+	dstPort := uint16(443)
+	state := 4
+
+	b.ResetTimer()
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			logger.Trace(conntrackMessage, srcIP, srcPort, dstIP, dstPort, state)
+		}
+	})
+}
+
+// BenchmarkLoggerBurst tests how the logger handles bursts of messages
+func BenchmarkLoggerBurst(b *testing.B) {
+	logger := createTestLogger()
+	defer cleanupLogger(logger)
+
+	conntrackMessage := "TCP connection %s:%d -> %s:%d state changed to %d"
+	srcIP := "192.168.1.1"
+	srcPort := uint16(12345)
+	dstIP := "10.0.0.1"
+	dstPort := uint16(443)
+	state := 4
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		for j := 0; j < 100; j++ {
+			logger.Trace(conntrackMessage, srcIP, srcPort, dstIP, dstPort, state)
+		}
+	}
+}
+
+func createTestLogger() *log.Logger {
+	logrusLogger := logrus.New()
+	logrusLogger.SetOutput(&discard{})
+	logrusLogger.SetLevel(logrus.TraceLevel)
+	return log.NewFromLogrus(logrusLogger)
+}
+
+func cleanupLogger(logger *log.Logger) {
+	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
+	defer cancel()
+	_ = logger.Stop(ctx)
+}

client/firewall/uspfilter/log/ringbuffer.go

@@ -1,85 +0,0 @@
-package log
-
-import "sync"
-
-// ringBuffer is a simple ring buffer implementation
-type ringBuffer struct {
-	buf  []byte
-	size int
-	r, w int64 // Read and write positions
-	mu   sync.Mutex
-}
-
-func newRingBuffer(size int) *ringBuffer {
-	return &ringBuffer{
-		buf:  make([]byte, size),
-		size: size,
-	}
-}
-
-func (r *ringBuffer) Write(p []byte) (n int, err error) {
-	if len(p) == 0 {
-		return 0, nil
-	}
-
-	r.mu.Lock()
-	defer r.mu.Unlock()
-
-	if len(p) > r.size {
-		p = p[:r.size]
-	}
-
-	n = len(p)
-
-	// Write data, handling wrap-around
-	pos := int(r.w % int64(r.size))
-	writeLen := min(len(p), r.size-pos)
-	copy(r.buf[pos:], p[:writeLen])
-
-	// If we have more data and need to wrap around
-	if writeLen < len(p) {
-		copy(r.buf, p[writeLen:])
-	}
-
-	// Update write position
-	r.w += int64(n)
-
-	return n, nil
-}
-
-func (r *ringBuffer) Read(p []byte) (n int, err error) {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-
-	if r.w == r.r {
-		return 0, nil
-	}
-
-	// Calculate available data accounting for wraparound
-	available := int(r.w - r.r)
-	if available < 0 {
-		available += r.size
-	}
-	available = min(available, r.size)
-
-	// Limit read to buffer size
-	toRead := min(available, len(p))
-	if toRead == 0 {
-		return 0, nil
-	}
-
-	// Read data, handling wrap-around
-	pos := int(r.r % int64(r.size))
-	readLen := min(toRead, r.size-pos)
-	n = copy(p, r.buf[pos:pos+readLen])
-
-	// If we need more data and need to wrap around
-	if readLen < toRead {
-		n += copy(p[readLen:toRead], r.buf[:toRead-readLen])
-	}
-
-	// Update read position
-	r.r += int64(n)
-
-	return n, nil
-}

client/firewall/uspfilter/uspfilter.go

@@ -22,6 +22,7 @@ import (
 	"github.com/netbirdio/netbird/client/firewall/uspfilter/forwarder"
 	nblog "github.com/netbirdio/netbird/client/firewall/uspfilter/log"
 	"github.com/netbirdio/netbird/client/iface/netstack"
+	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 )
 
@@ -96,6 +97,7 @@ type Manager struct {
 	tcpTracker  *conntrack.TCPTracker
 	forwarder   *forwarder.Forwarder
 	logger      *nblog.Logger
+	flowLogger  nftypes.FlowLogger
 }
 
 // decoder for packages
@@ -112,16 +114,16 @@ type decoder struct {
 }
 
 // Create userspace firewall manager constructor
-func Create(iface common.IFaceMapper, disableServerRoutes bool) (*Manager, error) {
+func Create(iface common.IFaceMapper, disableServerRoutes bool, flowLogger nftypes.FlowLogger) (*Manager, error) {
-	return create(iface, nil, disableServerRoutes)
+	return create(iface, nil, disableServerRoutes, flowLogger)
 }
 
-func CreateWithNativeFirewall(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableServerRoutes bool) (*Manager, error) {
+func CreateWithNativeFirewall(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableServerRoutes bool, flowLogger nftypes.FlowLogger) (*Manager, error) {
 	if nativeFirewall == nil {
 		return nil, errors.New("native firewall is nil")
 	}
 
-	mgr, err := create(iface, nativeFirewall, disableServerRoutes)
+	mgr, err := create(iface, nativeFirewall, disableServerRoutes, flowLogger)
 	if err != nil {
 		return nil, err
 	}
@@ -148,7 +150,7 @@ func parseCreateEnv() (bool, bool) {
 	return disableConntrack, enableLocalForwarding
 }
 
-func create(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableServerRoutes bool) (*Manager, error) {
+func create(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableServerRoutes bool, flowLogger nftypes.FlowLogger) (*Manager, error) {
 	disableConntrack, enableLocalForwarding := parseCreateEnv()
 
 	m := &Manager{
@@ -174,6 +176,7 @@ func create(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableSe
 		routingEnabled:      false,
 		stateful:            !disableConntrack,
 		logger:              nblog.NewFromLogrus(log.StandardLogger()),
+		flowLogger:          flowLogger,
 		netstack:            netstack.IsEnabled(),
 		localForwarding:     enableLocalForwarding,
 	}
@@ -185,9 +188,9 @@ func create(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableSe
 	if disableConntrack {
 		log.Info("conntrack is disabled")
 	} else {
-		m.udpTracker = conntrack.NewUDPTracker(conntrack.DefaultUDPTimeout, m.logger)
+		m.udpTracker = conntrack.NewUDPTracker(conntrack.DefaultUDPTimeout, m.logger, flowLogger)
-		m.icmpTracker = conntrack.NewICMPTracker(conntrack.DefaultICMPTimeout, m.logger)
+		m.icmpTracker = conntrack.NewICMPTracker(conntrack.DefaultICMPTimeout, m.logger, flowLogger)
-		m.tcpTracker = conntrack.NewTCPTracker(conntrack.DefaultTCPTimeout, m.logger)
+		m.tcpTracker = conntrack.NewTCPTracker(conntrack.DefaultTCPTimeout, m.logger, flowLogger)
 	}
 
 	// netstack needs the forwarder for local traffic
@@ -304,7 +307,7 @@ func (m *Manager) initForwarder() error {
 		return errors.New("forwarding not supported")
 	}
 
-	forwarder, err := forwarder.New(m.wgIface, m.logger, m.netstack)
+	forwarder, err := forwarder.New(m.wgIface, m.logger, m.flowLogger, m.netstack)
 	if err != nil {
 		m.routingEnabled = false
 		return fmt.Errorf("create forwarder: %w", err)
@@ -533,14 +536,7 @@ func (m *Manager) processOutgoingHooks(packetData []byte) bool {
 
 	// Track all protocols if stateful mode is enabled
 	if m.stateful {
-		switch d.decoded[1] {
+		m.trackOutbound(d, srcIP, dstIP)
-		case layers.LayerTypeUDP:
-			m.trackUDPOutbound(d, srcIP, dstIP)
-		case layers.LayerTypeTCP:
-			m.trackTCPOutbound(d, srcIP, dstIP)
-		case layers.LayerTypeICMPv4:
-			m.trackICMPOutbound(d, srcIP, dstIP)
-		}
 	}
 
 	// Process UDP hooks even if stateful mode is disabled
@@ -562,17 +558,6 @@ func (m *Manager) extractIPs(d *decoder) (srcIP, dstIP net.IP) {
 	}
 }
 
-func (m *Manager) trackTCPOutbound(d *decoder, srcIP, dstIP net.IP) {
-	flags := getTCPFlags(&d.tcp)
-	m.tcpTracker.TrackOutbound(
-		srcIP,
-		dstIP,
-		uint16(d.tcp.SrcPort),
-		uint16(d.tcp.DstPort),
-		flags,
-	)
-}
-
 func getTCPFlags(tcp *layers.TCP) uint8 {
 	var flags uint8
 	if tcp.SYN {
@@ -596,13 +581,34 @@ func getTCPFlags(tcp *layers.TCP) uint8 {
 	return flags
 }
 
-func (m *Manager) trackUDPOutbound(d *decoder, srcIP, dstIP net.IP) {
+func (m *Manager) trackOutbound(d *decoder, srcIP, dstIP net.IP) {
-	m.udpTracker.TrackOutbound(
+	transport := d.decoded[1]
-		srcIP,
+	switch transport {
-		dstIP,
+	case layers.LayerTypeUDP:
-		uint16(d.udp.SrcPort),
+		m.udpTracker.TrackOutbound(srcIP, dstIP, uint16(d.udp.SrcPort), uint16(d.udp.DstPort))
-		uint16(d.udp.DstPort),
+	case layers.LayerTypeTCP:
-	)
+		flags := getTCPFlags(&d.tcp)
+		m.tcpTracker.TrackOutbound(srcIP, dstIP, uint16(d.tcp.SrcPort), uint16(d.tcp.DstPort), flags)
+	case layers.LayerTypeICMPv4:
+		if d.icmp4.TypeCode.Type() == layers.ICMPv4TypeEchoRequest {
+			m.icmpTracker.TrackOutbound(srcIP, dstIP, d.icmp4.Id, d.icmp4.Seq)
+		}
+	}
+}
+
+func (m *Manager) trackInbound(d *decoder, srcIP, dstIP net.IP) {
+	transport := d.decoded[1]
+	switch transport {
+	case layers.LayerTypeUDP:
+		m.udpTracker.TrackInbound(srcIP, dstIP, uint16(d.udp.SrcPort), uint16(d.udp.DstPort))
+	case layers.LayerTypeTCP:
+		flags := getTCPFlags(&d.tcp)
+		m.tcpTracker.TrackInbound(srcIP, dstIP, uint16(d.tcp.SrcPort), uint16(d.tcp.DstPort), flags)
+	case layers.LayerTypeICMPv4:
+		if d.icmp4.TypeCode.Type() == layers.ICMPv4TypeEchoRequest {
+			m.icmpTracker.TrackInbound(srcIP, dstIP, d.icmp4.Id, d.icmp4.Seq)
+		}
+	}
 }
 
 func (m *Manager) checkUDPHooks(d *decoder, dstIP net.IP, packetData []byte) bool {
@@ -618,17 +624,6 @@ func (m *Manager) checkUDPHooks(d *decoder, dstIP net.IP, packetData []byte) boo
 	return false
 }
 
-func (m *Manager) trackICMPOutbound(d *decoder, srcIP, dstIP net.IP) {
-	if d.icmp4.TypeCode.Type() == layers.ICMPv4TypeEchoRequest {
-		m.icmpTracker.TrackOutbound(
-			srcIP,
-			dstIP,
-			d.icmp4.Id,
-			d.icmp4.Seq,
-		)
-	}
-}
-
 // dropFilter implements filtering logic for incoming packets.
 // If it returns true, the packet should be dropped.
 func (m *Manager) dropFilter(packetData []byte) bool {
@@ -675,6 +670,9 @@ func (m *Manager) handleLocalTraffic(d *decoder, srcIP, dstIP net.IP, packetData
 		return m.handleNetstackLocalTraffic(packetData)
 	}
 
+	// track inbound packets to get the correct direction and session id for flows
+	m.trackInbound(d, srcIP, dstIP)
+
 	return false
 }
 

client/firewall/uspfilter/uspfilter_bench_test.go

@@ -158,7 +158,7 @@ func BenchmarkCoreFiltering(b *testing.B) {
 				// Create manager and basic setup
 				manager, _ := Create(&IFaceMock{
 					SetFilterFunc: func(device.PacketFilter) error { return nil },
-				}, false)
+				}, false, flowLogger)
 				defer b.Cleanup(func() {
 					require.NoError(b, manager.Reset(nil))
 				})
@@ -203,7 +203,7 @@ func BenchmarkStateScaling(b *testing.B) {
 		b.Run(fmt.Sprintf("conns_%d", count), func(b *testing.B) {
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false)
+			}, false, flowLogger)
 			b.Cleanup(func() {
 				require.NoError(b, manager.Reset(nil))
 			})
@@ -251,7 +251,7 @@ func BenchmarkEstablishmentOverhead(b *testing.B) {
 		b.Run(sc.name, func(b *testing.B) {
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false)
+			}, false, flowLogger)
 			b.Cleanup(func() {
 				require.NoError(b, manager.Reset(nil))
 			})
@@ -450,7 +450,7 @@ func BenchmarkRoutedNetworkReturn(b *testing.B) {
 		b.Run(sc.name, func(b *testing.B) {
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false)
+			}, false, flowLogger)
 			b.Cleanup(func() {
 				require.NoError(b, manager.Reset(nil))
 			})
@@ -577,7 +577,7 @@ func BenchmarkLongLivedConnections(b *testing.B) {
 
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false)
+			}, false, flowLogger)
 			defer b.Cleanup(func() {
 				require.NoError(b, manager.Reset(nil))
 			})
@@ -668,7 +668,7 @@ func BenchmarkShortLivedConnections(b *testing.B) {
 
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false)
+			}, false, flowLogger)
 			defer b.Cleanup(func() {
 				require.NoError(b, manager.Reset(nil))
 			})
@@ -787,7 +787,7 @@ func BenchmarkParallelLongLivedConnections(b *testing.B) {
 
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false)
+			}, false, flowLogger)
 			defer b.Cleanup(func() {
 				require.NoError(b, manager.Reset(nil))
 			})
@@ -875,7 +875,7 @@ func BenchmarkParallelShortLivedConnections(b *testing.B) {
 
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false)
+			}, false, flowLogger)
 			defer b.Cleanup(func() {
 				require.NoError(b, manager.Reset(nil))
 			})

client/firewall/uspfilter/uspfilter_filter_test.go

@@ -34,7 +34,7 @@ func TestPeerACLFiltering(t *testing.T) {
 		},
 	}
 
-	manager, err := Create(ifaceMock, false)
+	manager, err := Create(ifaceMock, false, flowLogger)
 	require.NoError(t, err)
 	require.NotNil(t, manager)
 
@@ -302,7 +302,7 @@ func setupRoutedManager(tb testing.TB, network string) *Manager {
 		},
 	}
 
-	manager, err := Create(ifaceMock, false)
+	manager, err := Create(ifaceMock, false, flowLogger)
 	require.NoError(tb, manager.EnableRouting())
 	require.NoError(tb, err)
 	require.NotNil(tb, manager)

client/firewall/uspfilter/uspfilter_test.go

@@ -1,8 +1,10 @@
 package uspfilter
 
 import (
+	"context"
 	"fmt"
 	"net"
+	"net/netip"
 	"sync"
 	"testing"
 	"time"
@@ -18,9 +20,11 @@ import (
 	"github.com/netbirdio/netbird/client/firewall/uspfilter/log"
 	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/device"
+	"github.com/netbirdio/netbird/client/internal/netflow"
 )
 
 var logger = log.NewFromLogrus(logrus.StandardLogger())
+var flowLogger = netflow.NewManager(context.Background()).GetLogger()
 
 type IFaceMock struct {
 	SetFilterFunc   func(device.PacketFilter) error
@@ -62,7 +66,7 @@ func TestManagerCreate(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	m, err := Create(ifaceMock, false)
+	m, err := Create(ifaceMock, false, flowLogger)
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -82,7 +86,7 @@ func TestManagerAddPeerFiltering(t *testing.T) {
 		},
 	}
 
-	m, err := Create(ifaceMock, false)
+	m, err := Create(ifaceMock, false, flowLogger)
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -116,7 +120,7 @@ func TestManagerDeleteRule(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	m, err := Create(ifaceMock, false)
+	m, err := Create(ifaceMock, false, flowLogger)
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -187,7 +191,7 @@ func TestAddUDPPacketHook(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			manager, err := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false)
+			}, false, flowLogger)
 			require.NoError(t, err)
 
 			manager.AddUDPPacketHook(tt.in, tt.ip, tt.dPort, tt.hook)
@@ -236,7 +240,7 @@ func TestManagerReset(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	m, err := Create(ifaceMock, false)
+	m, err := Create(ifaceMock, false, flowLogger)
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -279,7 +283,7 @@ func TestNotMatchByIP(t *testing.T) {
 		},
 	}
 
-	m, err := Create(ifaceMock, false)
+	m, err := Create(ifaceMock, false, flowLogger)
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -347,7 +351,7 @@ func TestRemovePacketHook(t *testing.T) {
 	}
 
 	// creating manager instance
-	manager, err := Create(iface, false)
+	manager, err := Create(iface, false, flowLogger)
 	if err != nil {
 		t.Fatalf("Failed to create Manager: %s", err)
 	}
@@ -393,7 +397,7 @@ func TestRemovePacketHook(t *testing.T) {
 func TestProcessOutgoingHooks(t *testing.T) {
 	manager, err := Create(&IFaceMock{
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false)
+	}, false, flowLogger)
 	require.NoError(t, err)
 
 	manager.wgNetwork = &net.IPNet{
@@ -401,7 +405,7 @@ func TestProcessOutgoingHooks(t *testing.T) {
 		Mask: net.CIDRMask(16, 32),
 	}
 	manager.udpTracker.Close()
-	manager.udpTracker = conntrack.NewUDPTracker(100*time.Millisecond, logger)
+	manager.udpTracker = conntrack.NewUDPTracker(100*time.Millisecond, logger, flowLogger)
 	defer func() {
 		require.NoError(t, manager.Reset(nil))
 	}()
@@ -479,7 +483,7 @@ func TestUSPFilterCreatePerformance(t *testing.T) {
 			ifaceMock := &IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
 			}
-			manager, err := Create(ifaceMock, false)
+			manager, err := Create(ifaceMock, false, flowLogger)
 			require.NoError(t, err)
 			time.Sleep(time.Second)
 
@@ -506,7 +510,7 @@ func TestUSPFilterCreatePerformance(t *testing.T) {
 func TestStatefulFirewall_UDPTracking(t *testing.T) {
 	manager, err := Create(&IFaceMock{
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false)
+	}, false, flowLogger)
 	require.NoError(t, err)
 
 	manager.wgNetwork = &net.IPNet{
@@ -515,7 +519,7 @@ func TestStatefulFirewall_UDPTracking(t *testing.T) {
 	}
 
 	manager.udpTracker.Close() // Close the existing tracker
-	manager.udpTracker = conntrack.NewUDPTracker(200*time.Millisecond, logger)
+	manager.udpTracker = conntrack.NewUDPTracker(200*time.Millisecond, logger, flowLogger)
 	manager.decoders = sync.Pool{
 		New: func() any {
 			d := &decoder{
@@ -534,8 +538,8 @@ func TestStatefulFirewall_UDPTracking(t *testing.T) {
 	}()
 
 	// Set up packet parameters
-	srcIP := net.ParseIP("100.10.0.1")
+	srcIP := netip.MustParseAddr("100.10.0.1")
-	dstIP := net.ParseIP("100.10.0.100")
+	dstIP := netip.MustParseAddr("100.10.0.100")
 	srcPort := uint16(51334)
 	dstPort := uint16(53)
 
@@ -543,8 +547,8 @@ func TestStatefulFirewall_UDPTracking(t *testing.T) {
 	outboundIPv4 := &layers.IPv4{
 		TTL:      64,
 		Version:  4,
-		SrcIP:    srcIP,
+		SrcIP:    srcIP.AsSlice(),
-		DstIP:    dstIP,
+		DstIP:    dstIP.AsSlice(),
 		Protocol: layers.IPProtocolUDP,
 	}
 	outboundUDP := &layers.UDP{
@@ -573,11 +577,11 @@ func TestStatefulFirewall_UDPTracking(t *testing.T) {
 	require.False(t, drop, "Initial outbound packet should not be dropped")
 
 	// Verify connection was tracked
-	conn, exists := manager.udpTracker.GetConnection(srcIP, srcPort, dstIP, dstPort)
+	conn, exists := manager.udpTracker.GetConnection(srcIP.AsSlice(), srcPort, dstIP.AsSlice(), dstPort)
 
 	require.True(t, exists, "Connection should be tracked after outbound packet")
-	require.True(t, conntrack.ValidateIPs(conntrack.MakeIPAddr(srcIP), conn.SourceIP), "Source IP should match")
+	require.True(t, srcIP.Compare(conn.SourceIP) == 0, "Source IP should match")
-	require.True(t, conntrack.ValidateIPs(conntrack.MakeIPAddr(dstIP), conn.DestIP), "Destination IP should match")
+	require.True(t, dstIP.Compare(conn.DestIP) == 0, "Destination IP should match")
 	require.Equal(t, srcPort, conn.SourcePort, "Source port should match")
 	require.Equal(t, dstPort, conn.DestPort, "Destination port should match")
 
@@ -585,8 +589,8 @@ func TestStatefulFirewall_UDPTracking(t *testing.T) {
 	inboundIPv4 := &layers.IPv4{
 		TTL:      64,
 		Version:  4,
-		SrcIP:    dstIP, // Original destination is now source
+		SrcIP:    dstIP.AsSlice(), // Original destination is now source
-		DstIP:    srcIP, // Original source is now destination
+		DstIP:    srcIP.AsSlice(), // Original source is now destination
 		Protocol: layers.IPProtocolUDP,
 	}
 	inboundUDP := &layers.UDP{
@@ -641,7 +645,7 @@ func TestStatefulFirewall_UDPTracking(t *testing.T) {
 
 		// If the connection should still be valid, verify it exists
 		if cp.shouldAllow {
-			conn, exists := manager.udpTracker.GetConnection(srcIP, srcPort, dstIP, dstPort)
+			conn, exists := manager.udpTracker.GetConnection(srcIP.AsSlice(), srcPort, dstIP.AsSlice(), dstPort)
 			require.True(t, exists, "Connection should still exist during valid window")
 			require.True(t, time.Since(conn.GetLastSeen()) < manager.udpTracker.Timeout(),
 				"LastSeen should be updated for valid responses")

client/internal/acl/manager_test.go

@@ -1,6 +1,7 @@
 package acl
 
 import (
+	"context"
 	"net"
 	"testing"
 
@@ -10,9 +11,12 @@ import (
 	"github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/internal/acl/mocks"
+	"github.com/netbirdio/netbird/client/internal/netflow"
 	mgmProto "github.com/netbirdio/netbird/management/proto"
 )
 
+var flowLogger = netflow.NewManager(context.Background()).GetLogger()
+
 func TestDefaultManager(t *testing.T) {
 	networkMap := &mgmProto.NetworkMap{
 		FirewallRules: []*mgmProto.FirewallRule{
@@ -52,7 +56,7 @@ func TestDefaultManager(t *testing.T) {
 	ifaceMock.EXPECT().GetWGDevice().Return(nil).AnyTimes()
 
 	// we receive one rule from the management so for testing purposes ignore it
-	fw, err := firewall.NewFirewall(ifaceMock, nil, false)
+	fw, err := firewall.NewFirewall(ifaceMock, nil, flowLogger, false)
 	if err != nil {
 		t.Errorf("create firewall: %v", err)
 		return
@@ -346,7 +350,7 @@ func TestDefaultManagerEnableSSHRules(t *testing.T) {
 	ifaceMock.EXPECT().GetWGDevice().Return(nil).AnyTimes()
 
 	// we receive one rule from the management so for testing purposes ignore it
-	fw, err := firewall.NewFirewall(ifaceMock, nil, false)
+	fw, err := firewall.NewFirewall(ifaceMock, nil, flowLogger, false)
 	if err != nil {
 		t.Errorf("create firewall: %v", err)
 		return

client/internal/dns/server_test.go

@@ -22,6 +22,7 @@ import (
 	"github.com/netbirdio/netbird/client/iface/configurer"
 	"github.com/netbirdio/netbird/client/iface/device"
 	pfmock "github.com/netbirdio/netbird/client/iface/mocks"
+	"github.com/netbirdio/netbird/client/internal/netflow"
 	"github.com/netbirdio/netbird/client/internal/peer"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 	"github.com/netbirdio/netbird/client/internal/stdnet"
@@ -29,6 +30,8 @@ import (
 	"github.com/netbirdio/netbird/formatter"
 )
 
+var flowLogger = netflow.NewManager(context.Background()).GetLogger()
+
 type mocWGIface struct {
 	filter device.PacketFilter
 }
@@ -916,7 +919,7 @@ func createWgInterfaceWithBind(t *testing.T) (*iface.WGIface, error) {
 		return nil, err
 	}
 
-	pf, err := uspfilter.Create(wgIface, false)
+	pf, err := uspfilter.Create(wgIface, false, flowLogger)
 	if err != nil {
 		t.Fatalf("failed to create uspfilter: %v", err)
 		return nil, err

client/internal/engine.go

@@ -35,7 +35,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/dnsfwd"
 	"github.com/netbirdio/netbird/client/internal/ingressgw"
 	"github.com/netbirdio/netbird/client/internal/netflow"
-	"github.com/netbirdio/netbird/client/internal/netflow/types"
+	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
 	"github.com/netbirdio/netbird/client/internal/networkmonitor"
 	"github.com/netbirdio/netbird/client/internal/peer"
 	"github.com/netbirdio/netbird/client/internal/peer/guard"
@@ -191,7 +191,7 @@ type Engine struct {
 	persistNetworkMap bool
 	latestNetworkMap  *mgmProto.NetworkMap
 	connSemaphore     *semaphoregroup.SemaphoreGroup
-	flowManager       types.FlowManager
+	flowManager       nftypes.FlowManager
 }
 
 // Peer is an instance of the Connection Peer
@@ -454,7 +454,7 @@ func (e *Engine) createFirewall() error {
 	}
 
 	var err error
-	e.firewall, err = firewall.NewFirewall(e.wgInterface, e.stateManager, e.config.DisableServerRoutes)
+	e.firewall, err = firewall.NewFirewall(e.wgInterface, e.stateManager, e.flowManager.GetLogger(), e.config.DisableServerRoutes)
 	if err != nil || e.firewall == nil {
 		log.Errorf("failed creating firewall manager: %s", err)
 		return nil
@@ -721,11 +721,11 @@ func (e *Engine) handleFlowUpdate(config *mgmProto.FlowConfig) error {
 	return e.flowManager.Update(flowConfig)
 }
 
-func toFlowLoggerConfig(config *mgmProto.FlowConfig) (*types.FlowConfig, error) {
+func toFlowLoggerConfig(config *mgmProto.FlowConfig) (*nftypes.FlowConfig, error) {
 	if config.GetInterval() == nil {
 		return nil, errors.New("flow interval is nil")
 	}
-	return &types.FlowConfig{
+	return &nftypes.FlowConfig{
 		Enabled:        config.GetEnabled(),
 		URL:            config.GetUrl(),
 		TokenPayload:   config.GetTokenPayload(),

client/internal/netflow/types/types.go

@@ -7,17 +7,52 @@ import (
 	"github.com/google/uuid"
 )
 
+type Protocol uint8
+
+const (
+	ProtocolUnknown = 0
+	ICMP            = 1
+	TCP             = 6
+	UDP             = 17
+)
+
+func (p Protocol) String() string {
+	switch p {
+	case 1:
+		return "ICMP"
+	case 6:
+		return "TCP"
+	case 17:
+		return "UDP"
+	default:
+		return "unknown"
+	}
+}
+
 type Type int
 
 const (
-	TypeStart = iota
+	TypeUnknown = iota
+	TypeStart
 	TypeEnd
 )
 
 type Direction int
 
+func (d Direction) String() string {
+	switch d {
+	case Ingress:
+		return "ingress"
+	case Egress:
+		return "egress"
+	default:
+		return "unknown"
+	}
+}
+
 const (
-	Ingress = iota
+	DirectionUnknown = iota
+	Ingress
 	Egress
 )