[client] Replace the eBPF WireGuard proxy with loopback endpoint addressing (#7316)

client/firewall/iptables/family_linux.go

@@ -24,6 +24,7 @@ const (
 	tableFilter = "filter"
 	tableNat    = "nat"
 	tableMangle = "mangle"
+	tableRaw    = "raw"
 
 	// chainACLInput is the peer ACL chain that holds installed
 	// peer-filtering rules.
@@ -34,6 +35,7 @@ const (
 	mangleForwardKey chainKey = "MANGLE-FORWARD"
 
 	chainInput       = "INPUT"
+	chainOutput      = "OUTPUT"
 	chainPostrouting = "POSTROUTING"
 	chainPrerouting  = "PREROUTING"
 	chainForward     = "FORWARD"

client/firewall/iptables/manager_linux.go

@@ -25,9 +25,8 @@ type Manager struct {
 
 	wgIface iFaceMapper
 
-	ipv4Client   *iptables.IPTables
-	family4      *family
-	rawSupported bool
+	ipv4Client *iptables.IPTables
+	family4    *family
 
 	// IPv6 counterparts, nil when no v6 overlay
 	ipv6Client *iptables.IPTables
@@ -108,10 +107,6 @@ func (m *Manager) Init(stateManager *statemanager.Manager) error {
 		return err
 	}
 
-	if err := m.initNoTrackChain(); err != nil {
-		log.Warnf("raw table not available, notrack rules will be disabled: %v", err)
-	}
-
 	// Trust after all fatal init steps so a later failure doesn't leave the
 	// interface in firewalld's trusted zone without a corresponding Close.
 	if err := firewalld.TrustInterface(m.wgIface.Name()); err != nil {
@@ -285,10 +280,6 @@ func (m *Manager) Close(stateManager *statemanager.Manager) error {
 
 	var merr *multierror.Error
 
-	if err := m.cleanupNoTrackChain(); err != nil {
-		merr = multierror.Append(merr, fmt.Errorf("cleanup notrack chain: %w", err))
-	}
-
 	if m.hasIPv6() {
 		if err := m.family6.Reset(); err != nil {
 			merr = multierror.Append(merr, fmt.Errorf("reset v6 family: %w", err))
@@ -440,134 +431,6 @@ func (m *Manager) RemoveOutputDNAT(localAddr netip.Addr, protocol firewall.Proto
 	return m.family4.RemoveOutputDNAT(localAddr, protocol, originalPort, translatedPort)
 }
 
-const (
-	chainNameRaw = "NETBIRD-RAW"
-	chainOutput  = "OUTPUT"
-	tableRaw     = "raw"
-)
-
-// SetupEBPFProxyNoTrack creates notrack rules for eBPF proxy loopback traffic.
-// This prevents conntrack from tracking WireGuard proxy traffic on loopback, which
-// can interfere with MASQUERADE rules (e.g., from container runtimes like Podman/netavark).
-//
-// Traffic flows that need NOTRACK:
-//
-//  1. Egress: WireGuard -> fake endpoint (before eBPF rewrite)
-//     src=127.0.0.1:wgPort -> dst=127.0.0.1:fakePort
-//     Matched by: sport=wgPort
-//
-//  2. Egress: Proxy -> WireGuard (via raw socket)
-//     src=127.0.0.1:fakePort -> dst=127.0.0.1:wgPort
-//     Matched by: dport=wgPort
-//
-//  3. Ingress: Packets to WireGuard
-//     dst=127.0.0.1:wgPort
-//     Matched by: dport=wgPort
-//
-//  4. Ingress: Packets to proxy (after eBPF rewrite)
-//     dst=127.0.0.1:proxyPort
-//     Matched by: dport=proxyPort
-//
-// Rules are cleaned up when the firewall manager is closed.
-func (m *Manager) SetupEBPFProxyNoTrack(proxyPort, wgPort uint16) error {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-
-	if !m.rawSupported {
-		return fmt.Errorf("raw table not available")
-	}
-
-	wgPortStr := fmt.Sprintf("%d", wgPort)
-	proxyPortStr := fmt.Sprintf("%d", proxyPort)
-
-	// Egress rules: match outgoing loopback UDP packets
-	outputRuleSport := []string{"-o", "lo", "-s", "127.0.0.1", "-d", "127.0.0.1", "-p", "udp", "--sport", wgPortStr, "-j", "NOTRACK"}
-	if err := m.ipv4Client.AppendUnique(tableRaw, chainNameRaw, outputRuleSport...); err != nil {
-		return fmt.Errorf("add output sport notrack rule: %w", err)
-	}
-
-	outputRuleDport := []string{"-o", "lo", "-s", "127.0.0.1", "-d", "127.0.0.1", "-p", "udp", "--dport", wgPortStr, "-j", "NOTRACK"}
-	if err := m.ipv4Client.AppendUnique(tableRaw, chainNameRaw, outputRuleDport...); err != nil {
-		return fmt.Errorf("add output dport notrack rule: %w", err)
-	}
-
-	// Ingress rules: match incoming loopback UDP packets
-	preroutingRuleWg := []string{"-i", "lo", "-s", "127.0.0.1", "-d", "127.0.0.1", "-p", "udp", "--dport", wgPortStr, "-j", "NOTRACK"}
-	if err := m.ipv4Client.AppendUnique(tableRaw, chainNameRaw, preroutingRuleWg...); err != nil {
-		return fmt.Errorf("add prerouting wg notrack rule: %w", err)
-	}
-
-	preroutingRuleProxy := []string{"-i", "lo", "-s", "127.0.0.1", "-d", "127.0.0.1", "-p", "udp", "--dport", proxyPortStr, "-j", "NOTRACK"}
-	if err := m.ipv4Client.AppendUnique(tableRaw, chainNameRaw, preroutingRuleProxy...); err != nil {
-		return fmt.Errorf("add prerouting proxy notrack rule: %w", err)
-	}
-
-	log.Debugf("set up ebpf proxy notrack rules for ports %d,%d", proxyPort, wgPort)
-	return nil
-}
-
-func (m *Manager) initNoTrackChain() error {
-	if err := m.cleanupNoTrackChain(); err != nil {
-		log.Debugf("cleanup notrack chain: %v", err)
-	}
-
-	if err := m.ipv4Client.NewChain(tableRaw, chainNameRaw); err != nil {
-		return fmt.Errorf("create chain: %w", err)
-	}
-
-	jumpRule := []string{"-j", chainNameRaw}
-
-	if err := m.ipv4Client.InsertUnique(tableRaw, chainOutput, 1, jumpRule...); err != nil {
-		if delErr := m.ipv4Client.DeleteChain(tableRaw, chainNameRaw); delErr != nil {
-			log.Debugf("delete orphan chain: %v", delErr)
-		}
-		return fmt.Errorf("add output jump rule: %w", err)
-	}
-
-	if err := m.ipv4Client.InsertUnique(tableRaw, chainPrerouting, 1, jumpRule...); err != nil {
-		if delErr := m.ipv4Client.DeleteIfExists(tableRaw, chainOutput, jumpRule...); delErr != nil {
-			log.Debugf("delete output jump rule: %v", delErr)
-		}
-		if delErr := m.ipv4Client.DeleteChain(tableRaw, chainNameRaw); delErr != nil {
-			log.Debugf("delete orphan chain: %v", delErr)
-		}
-		return fmt.Errorf("add prerouting jump rule: %w", err)
-	}
-
-	m.rawSupported = true
-	return nil
-}
-
-func (m *Manager) cleanupNoTrackChain() error {
-	exists, err := m.ipv4Client.ChainExists(tableRaw, chainNameRaw)
-	if err != nil {
-		if !m.rawSupported {
-			return nil
-		}
-		return fmt.Errorf("check chain exists: %w", err)
-	}
-	if !exists {
-		return nil
-	}
-
-	jumpRule := []string{"-j", chainNameRaw}
-
-	if err := m.ipv4Client.DeleteIfExists(tableRaw, chainOutput, jumpRule...); err != nil {
-		return fmt.Errorf("remove output jump rule: %w", err)
-	}
-
-	if err := m.ipv4Client.DeleteIfExists(tableRaw, chainPrerouting, jumpRule...); err != nil {
-		return fmt.Errorf("remove prerouting jump rule: %w", err)
-	}
-
-	if err := m.ipv4Client.ClearAndDeleteChain(tableRaw, chainNameRaw); err != nil {
-		return fmt.Errorf("clear and delete chain: %w", err)
-	}
-
-	m.rawSupported = false
-	return nil
-}
-
 func getConntrackEstablished() []string {
 	return []string{"-m", "conntrack", "--ctstate", "RELATED,ESTABLISHED", "-j", "ACCEPT"}
 }

client/firewall/manager/firewall.go

@@ -192,10 +192,6 @@ type Manager interface {
 
 	// RemoveOutputDNAT removes an OUTPUT chain DNAT rule.
 	RemoveOutputDNAT(localAddr netip.Addr, protocol Protocol, originalPort, translatedPort uint16) error
-
-	// SetupEBPFProxyNoTrack creates static notrack rules for eBPF proxy loopback traffic.
-	// This prevents conntrack from interfering with WireGuard proxy communication.
-	SetupEBPFProxyNoTrack(proxyPort, wgPort uint16) error
 }
 
 // GenKey builds the rule id for this pair from the given format.

client/firewall/nftables/manager_linux.go

@@ -12,7 +12,6 @@ import (
 	"github.com/google/nftables/expr"
 	"github.com/hashicorp/go-multierror"
 	log "github.com/sirupsen/logrus"
-	"golang.org/x/sys/unix"
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
@@ -55,9 +54,6 @@ type Manager struct {
 	// IPv6 counterpart, nil when no v6 overlay.
 	family6 *family
 
-	notrackOutputChain     *nftables.Chain
-	notrackPreroutingChain *nftables.Chain
-
 	extMonitor *externalChainMonitor
 }
 
@@ -170,10 +166,6 @@ func (m *Manager) initFirewall() (err error) {
 		}
 	}
 
-	if err := m.initNoTrackChains(workTable); err != nil {
-		log.Warnf("raw priority chains not available, notrack rules will be disabled: %v", err)
-	}
-
 	return nil
 }
 
@@ -455,10 +447,6 @@ func (m *Manager) Flush() error {
 		}
 	}
 
-	if err := m.refreshNoTrackChains(); err != nil {
-		log.Errorf("failed to refresh notrack chains: %v", err)
-	}
-
 	return nil
 }
 
@@ -571,176 +559,6 @@ func (m *Manager) RemoveOutputDNAT(localAddr netip.Addr, protocol firewall.Proto
 	return m.family4.RemoveOutputDNAT(localAddr, protocol, originalPort, translatedPort)
 }
 
-const (
-	chainNameRawOutput     = "netbird-raw-out"
-	chainNameRawPrerouting = "netbird-raw-pre"
-)
-
-// SetupEBPFProxyNoTrack creates notrack rules for eBPF proxy loopback traffic.
-// This prevents conntrack from tracking WireGuard proxy traffic on loopback, which
-// can interfere with MASQUERADE rules (e.g., from container runtimes like Podman/netavark).
-//
-// Traffic flows that need NOTRACK:
-//
-//  1. Egress: WireGuard -> fake endpoint (before eBPF rewrite)
-//     src=127.0.0.1:wgPort -> dst=127.0.0.1:fakePort
-//     Matched by: sport=wgPort
-//
-//  2. Egress: Proxy -> WireGuard (via raw socket)
-//     src=127.0.0.1:fakePort -> dst=127.0.0.1:wgPort
-//     Matched by: dport=wgPort
-//
-//  3. Ingress: Packets to WireGuard
-//     dst=127.0.0.1:wgPort
-//     Matched by: dport=wgPort
-//
-//  4. Ingress: Packets to proxy (after eBPF rewrite)
-//     dst=127.0.0.1:proxyPort
-//     Matched by: dport=proxyPort
-//
-// Rules are cleaned up when the firewall manager is closed.
-func (m *Manager) SetupEBPFProxyNoTrack(proxyPort, wgPort uint16) error {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-
-	if m.notrackOutputChain == nil || m.notrackPreroutingChain == nil {
-		return fmt.Errorf("notrack chains not initialized")
-	}
-
-	proxyPortBytes := binaryutil.BigEndian.PutUint16(proxyPort)
-	wgPortBytes := binaryutil.BigEndian.PutUint16(wgPort)
-	loopback := []byte{127, 0, 0, 1}
-
-	// Egress rules: match outgoing loopback UDP packets
-	m.rConn.AddRule(&nftables.Rule{
-		Table: m.notrackOutputChain.Table,
-		Chain: m.notrackOutputChain,
-		Exprs: []expr.Any{
-			&expr.Meta{Key: expr.MetaKeyOIFNAME, Register: 1},
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: ifname("lo")},
-			&expr.Payload{DestRegister: 1, Base: expr.PayloadBaseNetworkHeader, Offset: 12, Len: 4}, // saddr
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: loopback},
-			&expr.Payload{DestRegister: 1, Base: expr.PayloadBaseNetworkHeader, Offset: 16, Len: 4}, // daddr
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: loopback},
-			&expr.Meta{Key: expr.MetaKeyL4PROTO, Register: 1},
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: []byte{unix.IPPROTO_UDP}},
-			&expr.Payload{DestRegister: 1, Base: expr.PayloadBaseTransportHeader, Offset: 0, Len: 2},
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: wgPortBytes}, // sport=wgPort
-			&expr.Counter{},
-			&expr.Notrack{},
-		},
-	})
-	m.rConn.AddRule(&nftables.Rule{
-		Table: m.notrackOutputChain.Table,
-		Chain: m.notrackOutputChain,
-		Exprs: []expr.Any{
-			&expr.Meta{Key: expr.MetaKeyOIFNAME, Register: 1},
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: ifname("lo")},
-			&expr.Payload{DestRegister: 1, Base: expr.PayloadBaseNetworkHeader, Offset: 12, Len: 4}, // saddr
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: loopback},
-			&expr.Payload{DestRegister: 1, Base: expr.PayloadBaseNetworkHeader, Offset: 16, Len: 4}, // daddr
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: loopback},
-			&expr.Meta{Key: expr.MetaKeyL4PROTO, Register: 1},
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: []byte{unix.IPPROTO_UDP}},
-			&expr.Payload{DestRegister: 1, Base: expr.PayloadBaseTransportHeader, Offset: 2, Len: 2},
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: wgPortBytes}, // dport=wgPort
-			&expr.Counter{},
-			&expr.Notrack{},
-		},
-	})
-
-	// Ingress rules: match incoming loopback UDP packets
-	m.rConn.AddRule(&nftables.Rule{
-		Table: m.notrackPreroutingChain.Table,
-		Chain: m.notrackPreroutingChain,
-		Exprs: []expr.Any{
-			&expr.Meta{Key: expr.MetaKeyIIFNAME, Register: 1},
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: ifname("lo")},
-			&expr.Payload{DestRegister: 1, Base: expr.PayloadBaseNetworkHeader, Offset: 12, Len: 4}, // saddr
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: loopback},
-			&expr.Payload{DestRegister: 1, Base: expr.PayloadBaseNetworkHeader, Offset: 16, Len: 4}, // daddr
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: loopback},
-			&expr.Meta{Key: expr.MetaKeyL4PROTO, Register: 1},
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: []byte{unix.IPPROTO_UDP}},
-			&expr.Payload{DestRegister: 1, Base: expr.PayloadBaseTransportHeader, Offset: 2, Len: 2},
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: wgPortBytes}, // dport=wgPort
-			&expr.Counter{},
-			&expr.Notrack{},
-		},
-	})
-	m.rConn.AddRule(&nftables.Rule{
-		Table: m.notrackPreroutingChain.Table,
-		Chain: m.notrackPreroutingChain,
-		Exprs: []expr.Any{
-			&expr.Meta{Key: expr.MetaKeyIIFNAME, Register: 1},
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: ifname("lo")},
-			&expr.Payload{DestRegister: 1, Base: expr.PayloadBaseNetworkHeader, Offset: 12, Len: 4}, // saddr
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: loopback},
-			&expr.Payload{DestRegister: 1, Base: expr.PayloadBaseNetworkHeader, Offset: 16, Len: 4}, // daddr
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: loopback},
-			&expr.Meta{Key: expr.MetaKeyL4PROTO, Register: 1},
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: []byte{unix.IPPROTO_UDP}},
-			&expr.Payload{DestRegister: 1, Base: expr.PayloadBaseTransportHeader, Offset: 2, Len: 2},
-			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: proxyPortBytes}, // dport=proxyPort
-			&expr.Counter{},
-			&expr.Notrack{},
-		},
-	})
-
-	if err := m.rConn.Flush(); err != nil {
-		return fmt.Errorf("flush notrack rules: %w", err)
-	}
-
-	log.Debugf("set up ebpf proxy notrack rules for ports %d,%d", proxyPort, wgPort)
-	return nil
-}
-
-func (m *Manager) initNoTrackChains(table *nftables.Table) error {
-	m.notrackOutputChain = m.rConn.AddChain(&nftables.Chain{
-		Name:     chainNameRawOutput,
-		Table:    table,
-		Type:     nftables.ChainTypeFilter,
-		Hooknum:  nftables.ChainHookOutput,
-		Priority: nftables.ChainPriorityRaw,
-	})
-
-	m.notrackPreroutingChain = m.rConn.AddChain(&nftables.Chain{
-		Name:     chainNameRawPrerouting,
-		Table:    table,
-		Type:     nftables.ChainTypeFilter,
-		Hooknum:  nftables.ChainHookPrerouting,
-		Priority: nftables.ChainPriorityRaw,
-	})
-
-	if err := m.rConn.Flush(); err != nil {
-		return fmt.Errorf("flush chain creation: %w", err)
-	}
-
-	return nil
-}
-
-func (m *Manager) refreshNoTrackChains() error {
-	chains, err := m.rConn.ListChainsOfTableFamily(nftables.TableFamilyIPv4)
-	if err != nil {
-		return fmt.Errorf("list chains: %w", err)
-	}
-
-	tableName := getTableName()
-	for _, c := range chains {
-		if c.Table.Name != tableName {
-			continue
-		}
-		switch c.Name {
-		case chainNameRawOutput:
-			m.notrackOutputChain = c
-		case chainNameRawPrerouting:
-			m.notrackPreroutingChain = c
-		}
-	}
-
-	return nil
-}
-
 func (m *Manager) createWorkTable() (*nftables.Table, error) {
 	return m.createWorkTableFamily(nftables.TableFamilyIPv4)
 }

client/firewall/nftables/routing_linux.go

@@ -192,7 +192,7 @@ func (r *family) addPostroutingRules() {
 			Data:     binaryutil.NativeEndian.PutUint32(nbnet.PreroutingFwmarkMasquerade),
 		},
 
-		// We need to exclude the loopback interface as this changes the ebpf proxy port
+		// We need to exclude the loopback interface as this changes the wg proxy port
 		&expr.Meta{
 			Key:      expr.MetaKeyOIFNAME,
 			Register: 1,

client/firewall/uspfilter/filter.go

@@ -879,12 +879,6 @@ func (m *Manager) resetState() {
 	}
 }
 
-// SetupEBPFProxyNoTrack is not supported by the userspace firewall: eBPF isn't
-// used in userspace mode, so this should never be called.
-func (m *Manager) SetupEBPFProxyNoTrack(uint16, uint16) error {
-	return errNotSupported
-}
-
 // UpdateSet updates the rule destinations associated with the given set
 // by merging the existing prefixes with the new ones, then deduplicating.
 func (m *Manager) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {