[client, management] Add port forwarding (#3275)

Add initial support to ingress ports on the client code.

- new types where added
- new protocol messages and controller

client/firewall/iptables/acl_linux.go

@@ -30,10 +30,8 @@ type entry struct {
 }
 
 type aclManager struct {
-	iptablesClient     *iptables.IPTables
-	wgIface            iFaceMapper
-	routingFwChainName string
-
+	iptablesClient  *iptables.IPTables
+	wgIface         iFaceMapper
 	entries         aclEntries
 	optionalEntries map[string][]entry
 	ipsetStore      *ipsetStore
@@ -41,12 +39,10 @@ type aclManager struct {
 	stateManager *statemanager.Manager
 }
 
-func newAclManager(iptablesClient *iptables.IPTables, wgIface iFaceMapper, routingFwChainName string) (*aclManager, error) {
+func newAclManager(iptablesClient *iptables.IPTables, wgIface iFaceMapper) (*aclManager, error) {
 	m := &aclManager{
-		iptablesClient:     iptablesClient,
-		wgIface:            wgIface,
-		routingFwChainName: routingFwChainName,
-
+		iptablesClient:  iptablesClient,
+		wgIface:         wgIface,
 		entries:         make(map[string][][]string),
 		optionalEntries: make(map[string][]entry),
 		ipsetStore:      newIpsetStore(),
@@ -314,9 +310,12 @@ func (m *aclManager) seedInitialEntries() {
 	m.appendToEntries("INPUT", []string{"-i", m.wgIface.Name(), "-j", chainNameInputRules})
 	m.appendToEntries("INPUT", append([]string{"-i", m.wgIface.Name()}, established...))
 
+	// Inbound is handled by our ACLs, the rest is dropped.
+	// For outbound we respect the FORWARD policy. However, we need to allow established/related traffic for inbound rules.
 	m.appendToEntries("FORWARD", []string{"-i", m.wgIface.Name(), "-j", "DROP"})
-	m.appendToEntries("FORWARD", []string{"-i", m.wgIface.Name(), "-j", m.routingFwChainName})
-	m.appendToEntries("FORWARD", append([]string{"-o", m.wgIface.Name()}, established...))
+
+	m.appendToEntries("FORWARD", []string{"-o", m.wgIface.Name(), "-j", chainRTFWDOUT})
+	m.appendToEntries("FORWARD", []string{"-i", m.wgIface.Name(), "-j", chainRTFWDIN})
 }
 
 func (m *aclManager) seedInitialOptionalEntries() {

client/firewall/iptables/manager_linux.go

@@ -52,7 +52,7 @@ func Create(wgIface iFaceMapper) (*Manager, error) {
 		return nil, fmt.Errorf("create router: %w", err)
 	}
 
-	m.aclMgr, err = newAclManager(iptablesClient, wgIface, chainRTFWD)
+	m.aclMgr, err = newAclManager(iptablesClient, wgIface)
 	if err != nil {
 		return nil, fmt.Errorf("create acl manager: %w", err)
 	}
@@ -226,6 +226,22 @@ func (m *Manager) DisableRouting() error {
 	return nil
 }
 
+// AddDNATRule adds a DNAT rule
+func (m *Manager) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error) {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	return m.router.AddDNATRule(rule)
+}
+
+// DeleteDNATRule deletes a DNAT rule
+func (m *Manager) DeleteDNATRule(rule firewall.Rule) error {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	return m.router.DeleteDNATRule(rule)
+}
+
 func getConntrackEstablished() []string {
 	return []string{"-m", "conntrack", "--ctstate", "RELATED,ESTABLISHED", "-j", "ACCEPT"}
 }

client/firewall/iptables/router_linux.go

@@ -16,6 +16,7 @@ import (
 	nberrors "github.com/netbirdio/netbird/client/errors"
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/internal/acl/id"
+	"github.com/netbirdio/netbird/client/internal/routemanager/ipfwdstate"
 	"github.com/netbirdio/netbird/client/internal/routemanager/refcounter"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 	nbnet "github.com/netbirdio/netbird/util/net"
@@ -23,22 +24,36 @@ import (
 
 // constants needed to manage and create iptable rules
 const (
-	tableFilter             = "filter"
-	tableNat                = "nat"
-	tableMangle             = "mangle"
+	tableFilter = "filter"
+	tableNat    = "nat"
+	tableMangle = "mangle"
+
 	chainPOSTROUTING        = "POSTROUTING"
 	chainPREROUTING         = "PREROUTING"
 	chainRTNAT              = "NETBIRD-RT-NAT"
-	chainRTFWD              = "NETBIRD-RT-FWD"
+	chainRTFWDIN            = "NETBIRD-RT-FWD-IN"
+	chainRTFWDOUT           = "NETBIRD-RT-FWD-OUT"
 	chainRTPRE              = "NETBIRD-RT-PRE"
+	chainRTRDR              = "NETBIRD-RT-RDR"
 	routingFinalForwardJump = "ACCEPT"
 	routingFinalNatJump     = "MASQUERADE"
 
-	jumpPre  = "jump-pre"
-	jumpNat  = "jump-nat"
-	matchSet = "--match-set"
+	jumpManglePre = "jump-mangle-pre"
+	jumpNatPre    = "jump-nat-pre"
+	jumpNatPost   = "jump-nat-post"
+	matchSet      = "--match-set"
+
+	dnatSuffix = "_dnat"
+	snatSuffix = "_snat"
+	fwdSuffix  = "_fwd"
 )
 
+type ruleInfo struct {
+	chain string
+	table string
+	rule  []string
+}
+
 type routeFilteringRuleParams struct {
 	Sources     []netip.Prefix
 	Destination netip.Prefix
@@ -62,6 +77,7 @@ type router struct {
 	legacyManagement bool
 
 	stateManager *statemanager.Manager
+	ipFwdState   *ipfwdstate.IPForwardingState
 }
 
 func newRouter(iptablesClient *iptables.IPTables, wgIface iFaceMapper) (*router, error) {
@@ -69,6 +85,7 @@ func newRouter(iptablesClient *iptables.IPTables, wgIface iFaceMapper) (*router,
 		iptablesClient: iptablesClient,
 		rules:          make(map[string][]string),
 		wgIface:        wgIface,
+		ipFwdState:     ipfwdstate.NewIPForwardingState(),
 	}
 
 	r.ipsetCounter = refcounter.New(
@@ -139,9 +156,9 @@ func (r *router) AddRouteFiltering(
 	var err error
 	if action == firewall.ActionDrop {
 		// after the established rule
-		err = r.iptablesClient.Insert(tableFilter, chainRTFWD, 2, rule...)
+		err = r.iptablesClient.Insert(tableFilter, chainRTFWDIN, 2, rule...)
 	} else {
-		err = r.iptablesClient.Append(tableFilter, chainRTFWD, rule...)
+		err = r.iptablesClient.Append(tableFilter, chainRTFWDIN, rule...)
 	}
 
 	if err != nil {
@@ -156,12 +173,12 @@ func (r *router) AddRouteFiltering(
 }
 
 func (r *router) DeleteRouteRule(rule firewall.Rule) error {
-	ruleKey := rule.GetRuleID()
+	ruleKey := rule.ID()
 
 	if rule, exists := r.rules[ruleKey]; exists {
 		setName := r.findSetNameInRule(rule)
 
-		if err := r.iptablesClient.Delete(tableFilter, chainRTFWD, rule...); err != nil {
+		if err := r.iptablesClient.Delete(tableFilter, chainRTFWDIN, rule...); err != nil {
 			return fmt.Errorf("delete route rule: %v", err)
 		}
 		delete(r.rules, ruleKey)
@@ -212,6 +229,10 @@ func (r *router) deleteIpSet(setName string) error {
 
 // AddNatRule inserts an iptables rule pair into the nat chain
 func (r *router) AddNatRule(pair firewall.RouterPair) error {
+	if err := r.ipFwdState.RequestForwarding(); err != nil {
+		return err
+	}
+
 	if r.legacyManagement {
 		log.Warnf("This peer is connected to a NetBird Management service with an older version. Allowing all traffic for %s", pair.Destination)
 		if err := r.addLegacyRouteRule(pair); err != nil {
@@ -238,6 +259,10 @@ func (r *router) AddNatRule(pair firewall.RouterPair) error {
 
 // RemoveNatRule removes an iptables rule pair from forwarding and nat chains
 func (r *router) RemoveNatRule(pair firewall.RouterPair) error {
+	if err := r.ipFwdState.ReleaseForwarding(); err != nil {
+		log.Errorf("%v", err)
+	}
+
 	if err := r.removeNatRule(pair); err != nil {
 		return fmt.Errorf("remove nat rule: %w", err)
 	}
@@ -264,7 +289,7 @@ func (r *router) addLegacyRouteRule(pair firewall.RouterPair) error {
 	}
 
 	rule := []string{"-s", pair.Source.String(), "-d", pair.Destination.String(), "-j", routingFinalForwardJump}
-	if err := r.iptablesClient.Append(tableFilter, chainRTFWD, rule...); err != nil {
+	if err := r.iptablesClient.Append(tableFilter, chainRTFWDIN, rule...); err != nil {
 		return fmt.Errorf("add legacy forwarding rule %s -> %s: %v", pair.Source, pair.Destination, err)
 	}
 
@@ -277,7 +302,7 @@ func (r *router) removeLegacyRouteRule(pair firewall.RouterPair) error {
 	ruleKey := firewall.GenKey(firewall.ForwardingFormat, pair)
 
 	if rule, exists := r.rules[ruleKey]; exists {
-		if err := r.iptablesClient.DeleteIfExists(tableFilter, chainRTFWD, rule...); err != nil {
+		if err := r.iptablesClient.DeleteIfExists(tableFilter, chainRTFWDIN, rule...); err != nil {
 			return fmt.Errorf("remove legacy forwarding rule %s -> %s: %v", pair.Source, pair.Destination, err)
 		}
 		delete(r.rules, ruleKey)
@@ -305,7 +330,7 @@ func (r *router) RemoveAllLegacyRouteRules() error {
 		if !strings.HasPrefix(k, firewall.ForwardingFormatPrefix) {
 			continue
 		}
-		if err := r.iptablesClient.DeleteIfExists(tableFilter, chainRTFWD, rule...); err != nil {
+		if err := r.iptablesClient.DeleteIfExists(tableFilter, chainRTFWDIN, rule...); err != nil {
 			merr = multierror.Append(merr, fmt.Errorf("remove legacy forwarding rule: %v", err))
 		} else {
 			delete(r.rules, k)
@@ -343,9 +368,11 @@ func (r *router) cleanUpDefaultForwardRules() error {
 		chain string
 		table string
 	}{
-		{chainRTFWD, tableFilter},
-		{chainRTNAT, tableNat},
+		{chainRTFWDIN, tableFilter},
+		{chainRTFWDOUT, tableFilter},
 		{chainRTPRE, tableMangle},
+		{chainRTNAT, tableNat},
+		{chainRTRDR, tableNat},
 	} {
 		ok, err := r.iptablesClient.ChainExists(chainInfo.table, chainInfo.chain)
 		if err != nil {
@@ -365,16 +392,22 @@ func (r *router) createContainers() error {
 		chain string
 		table string
 	}{
-		{chainRTFWD, tableFilter},
+		{chainRTFWDIN, tableFilter},
+		{chainRTFWDOUT, tableFilter},
 		{chainRTPRE, tableMangle},
 		{chainRTNAT, tableNat},
+		{chainRTRDR, tableNat},
 	} {
-		if err := r.createAndSetupChain(chainInfo.chain); err != nil {
+		if err := r.iptablesClient.NewChain(chainInfo.table, chainInfo.chain); err != nil {
 			return fmt.Errorf("create chain %s in table %s: %w", chainInfo.chain, chainInfo.table, err)
 		}
 	}
 
-	if err := r.insertEstablishedRule(chainRTFWD); err != nil {
+	if err := r.insertEstablishedRule(chainRTFWDIN); err != nil {
+		return fmt.Errorf("insert established rule: %w", err)
+	}
+
+	if err := r.insertEstablishedRule(chainRTFWDOUT); err != nil {
 		return fmt.Errorf("insert established rule: %w", err)
 	}
 
@@ -415,27 +448,6 @@ func (r *router) addPostroutingRules() error {
 	return nil
 }
 
-func (r *router) createAndSetupChain(chain string) error {
-	table := r.getTableForChain(chain)
-
-	if err := r.iptablesClient.NewChain(table, chain); err != nil {
-		return fmt.Errorf("failed creating chain %s, error: %v", chain, err)
-	}
-
-	return nil
-}
-
-func (r *router) getTableForChain(chain string) string {
-	switch chain {
-	case chainRTNAT:
-		return tableNat
-	case chainRTPRE:
-		return tableMangle
-	default:
-		return tableFilter
-	}
-}
-
 func (r *router) insertEstablishedRule(chain string) error {
 	establishedRule := getConntrackEstablished()
 
@@ -454,28 +466,43 @@ func (r *router) addJumpRules() error {
 	// Jump to NAT chain
 	natRule := []string{"-j", chainRTNAT}
 	if err := r.iptablesClient.Insert(tableNat, chainPOSTROUTING, 1, natRule...); err != nil {
-		return fmt.Errorf("add nat jump rule: %v", err)
+		return fmt.Errorf("add nat postrouting jump rule: %v", err)
 	}
-	r.rules[jumpNat] = natRule
+	r.rules[jumpNatPost] = natRule
 
-	// Jump to prerouting chain
+	// Jump to mangle prerouting chain
 	preRule := []string{"-j", chainRTPRE}
 	if err := r.iptablesClient.Insert(tableMangle, chainPREROUTING, 1, preRule...); err != nil {
-		return fmt.Errorf("add prerouting jump rule: %v", err)
+		return fmt.Errorf("add mangle prerouting jump rule: %v", err)
 	}
-	r.rules[jumpPre] = preRule
+	r.rules[jumpManglePre] = preRule
+
+	// Jump to nat prerouting chain
+	rdrRule := []string{"-j", chainRTRDR}
+	if err := r.iptablesClient.Insert(tableNat, chainPREROUTING, 1, rdrRule...); err != nil {
+		return fmt.Errorf("add nat prerouting jump rule: %v", err)
+	}
+	r.rules[jumpNatPre] = rdrRule
 
 	return nil
 }
 
 func (r *router) cleanJumpRules() error {
-	for _, ruleKey := range []string{jumpNat, jumpPre} {
+	for _, ruleKey := range []string{jumpNatPost, jumpManglePre, jumpNatPre} {
 		if rule, exists := r.rules[ruleKey]; exists {
-			table := tableNat
-			chain := chainPOSTROUTING
-			if ruleKey == jumpPre {
+			var table, chain string
+			switch ruleKey {
+			case jumpNatPost:
+				table = tableNat
+				chain = chainPOSTROUTING
+			case jumpManglePre:
 				table = tableMangle
 				chain = chainPREROUTING
+			case jumpNatPre:
+				table = tableNat
+				chain = chainPREROUTING
+			default:
+				return fmt.Errorf("unknown jump rule: %s", ruleKey)
 			}
 
 			if err := r.iptablesClient.DeleteIfExists(table, chain, rule...); err != nil {
@@ -520,6 +547,8 @@ func (r *router) addNatRule(pair firewall.RouterPair) error {
 	}
 
 	r.rules[ruleKey] = rule
+
+	r.updateState()
 	return nil
 }
 
@@ -535,6 +564,7 @@ func (r *router) removeNatRule(pair firewall.RouterPair) error {
 		log.Debugf("marking rule %s not found", ruleKey)
 	}
 
+	r.updateState()
 	return nil
 }
 
@@ -564,6 +594,137 @@ func (r *router) updateState() {
 	}
 }
 
+func (r *router) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error) {
+	if err := r.ipFwdState.RequestForwarding(); err != nil {
+		return nil, err
+	}
+
+	ruleKey := rule.ID()
+	if _, exists := r.rules[ruleKey+dnatSuffix]; exists {
+		return rule, nil
+	}
+
+	toDestination := rule.TranslatedAddress.String()
+	switch {
+	case len(rule.TranslatedPort.Values) == 0:
+		// no translated port, use original port
+	case len(rule.TranslatedPort.Values) == 1:
+		toDestination += fmt.Sprintf(":%d", rule.TranslatedPort.Values[0])
+	case rule.TranslatedPort.IsRange && len(rule.TranslatedPort.Values) == 2:
+		// need the "/originalport" suffix to avoid dnat port randomization
+		toDestination += fmt.Sprintf(":%d-%d/%d", rule.TranslatedPort.Values[0], rule.TranslatedPort.Values[1], rule.DestinationPort.Values[0])
+	default:
+		return nil, fmt.Errorf("invalid translated port: %v", rule.TranslatedPort)
+	}
+
+	proto := strings.ToLower(string(rule.Protocol))
+
+	rules := make(map[string]ruleInfo, 3)
+
+	// DNAT rule
+	dnatRule := []string{
+		"!", "-i", r.wgIface.Name(),
+		"-p", proto,
+		"-j", "DNAT",
+		"--to-destination", toDestination,
+	}
+	dnatRule = append(dnatRule, applyPort("--dport", &rule.DestinationPort)...)
+	rules[ruleKey+dnatSuffix] = ruleInfo{
+		table: tableNat,
+		chain: chainRTRDR,
+		rule:  dnatRule,
+	}
+
+	// SNAT rule
+	snatRule := []string{
+		"-o", r.wgIface.Name(),
+		"-p", proto,
+		"-d", rule.TranslatedAddress.String(),
+		"-j", "MASQUERADE",
+	}
+	snatRule = append(snatRule, applyPort("--dport", &rule.TranslatedPort)...)
+	rules[ruleKey+snatSuffix] = ruleInfo{
+		table: tableNat,
+		chain: chainRTNAT,
+		rule:  snatRule,
+	}
+
+	// Forward filtering rule, if fwd policy is DROP
+	forwardRule := []string{
+		"-o", r.wgIface.Name(),
+		"-p", proto,
+		"-d", rule.TranslatedAddress.String(),
+		"-j", "ACCEPT",
+	}
+	forwardRule = append(forwardRule, applyPort("--dport", &rule.TranslatedPort)...)
+	rules[ruleKey+fwdSuffix] = ruleInfo{
+		table: tableFilter,
+		chain: chainRTFWDOUT,
+		rule:  forwardRule,
+	}
+
+	for key, ruleInfo := range rules {
+		if err := r.iptablesClient.Append(ruleInfo.table, ruleInfo.chain, ruleInfo.rule...); err != nil {
+			if rollbackErr := r.rollbackRules(rules); rollbackErr != nil {
+				log.Errorf("rollback failed: %v", rollbackErr)
+			}
+			return nil, fmt.Errorf("add rule %s: %w", key, err)
+		}
+		r.rules[key] = ruleInfo.rule
+	}
+
+	r.updateState()
+	return rule, nil
+}
+
+func (r *router) rollbackRules(rules map[string]ruleInfo) error {
+	var merr *multierror.Error
+	for key, ruleInfo := range rules {
+		if err := r.iptablesClient.DeleteIfExists(ruleInfo.table, ruleInfo.chain, ruleInfo.rule...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("rollback rule %s: %w", key, err))
+			// On rollback error, add to rules map for next cleanup
+			r.rules[key] = ruleInfo.rule
+		}
+	}
+	if merr != nil {
+		r.updateState()
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *router) DeleteDNATRule(rule firewall.Rule) error {
+	if err := r.ipFwdState.ReleaseForwarding(); err != nil {
+		log.Errorf("%v", err)
+	}
+
+	ruleKey := rule.ID()
+
+	var merr *multierror.Error
+	if dnatRule, exists := r.rules[ruleKey+dnatSuffix]; exists {
+		if err := r.iptablesClient.Delete(tableNat, chainRTRDR, dnatRule...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete DNAT rule: %w", err))
+		}
+		delete(r.rules, ruleKey+dnatSuffix)
+	}
+
+	if snatRule, exists := r.rules[ruleKey+snatSuffix]; exists {
+		if err := r.iptablesClient.Delete(tableNat, chainRTNAT, snatRule...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete SNAT rule: %w", err))
+		}
+		delete(r.rules, ruleKey+snatSuffix)
+	}
+
+	if fwdRule, exists := r.rules[ruleKey+fwdSuffix]; exists {
+		if err := r.iptablesClient.Delete(tableFilter, chainRTFWDIN, fwdRule...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete forward rule: %w", err))
+		}
+		delete(r.rules, ruleKey+fwdSuffix)
+	}
+
+	r.updateState()
+	return nberrors.FormatErrorOrNil(merr)
+}
+
 func genRouteFilteringRuleSpec(params routeFilteringRuleParams) []string {
 	var rule []string
 

client/firewall/iptables/router_linux_test.go

@@ -39,12 +39,14 @@ func TestIptablesManager_RestoreOrCreateContainers(t *testing.T) {
 	}()
 
 	// Now 5 rules:
-	// 1. established rule in forward chain
-	// 2. jump rule to NAT chain
-	// 3. jump rule to PRE chain
-	// 4. static outbound masquerade rule
-	// 5. static return masquerade rule
-	require.Len(t, manager.rules, 5, "should have created rules map")
+	// 1. established rule forward in
+	// 2. estbalished rule forward out
+	// 3. jump rule to POST nat chain
+	// 4. jump rule to PRE mangle chain
+	// 5. jump rule to PRE nat chain
+	// 6. static outbound masquerade rule
+	// 7. static return masquerade rule
+	require.Len(t, manager.rules, 7, "should have created rules map")
 
 	exists, err := manager.iptablesClient.Exists(tableNat, chainPOSTROUTING, "-j", chainRTNAT)
 	require.NoError(t, err, "should be able to query the iptables %s table and %s chain", tableNat, chainPOSTROUTING)
@@ -332,14 +334,14 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 			require.NoError(t, err, "AddRouteFiltering failed")
 
 			// Check if the rule is in the internal map
-			rule, ok := r.rules[ruleKey.GetRuleID()]
+			rule, ok := r.rules[ruleKey.ID()]
 			assert.True(t, ok, "Rule not found in internal map")
 
 			// Log the internal rule
 			t.Logf("Internal rule: %v", rule)
 
 			// Check if the rule exists in iptables
-			exists, err := iptablesClient.Exists(tableFilter, chainRTFWD, rule...)
+			exists, err := iptablesClient.Exists(tableFilter, chainRTFWDIN, rule...)
 			assert.NoError(t, err, "Failed to check rule existence")
 			assert.True(t, exists, "Rule not found in iptables")
 

client/firewall/iptables/rule.go

@@ -12,6 +12,6 @@ type Rule struct {
 }
 
 // GetRuleID returns the rule id
-func (r *Rule) GetRuleID() string {
+func (r *Rule) ID() string {
 	return r.ruleID
 }

client/firewall/manager/firewall.go

@@ -26,8 +26,8 @@ const (
 // Each firewall type for different OS can use different type
 // of the properties to hold data of the created rule
 type Rule interface {
-	// GetRuleID returns the rule id
-	GetRuleID() string
+	// ID returns the rule id
+	ID() string
 }
 
 // RuleDirection is the traffic direction which a rule is applied
@@ -105,6 +105,12 @@ type Manager interface {
 	EnableRouting() error
 
 	DisableRouting() error
+
+	// AddDNATRule adds a DNAT rule
+	AddDNATRule(ForwardRule) (Rule, error)
+
+	// DeleteDNATRule deletes a DNAT rule
+	DeleteDNATRule(Rule) error
 }
 
 func GenKey(format string, pair RouterPair) string {

client/firewall/manager/forward_rule.go

@@ -0,0 +1,27 @@
+package manager
+
+import (
+	"fmt"
+	"net/netip"
+)
+
+// ForwardRule todo figure out better place to this to avoid circular imports
+type ForwardRule struct {
+	Protocol          Protocol
+	DestinationPort   Port
+	TranslatedAddress netip.Addr
+	TranslatedPort    Port
+}
+
+func (r ForwardRule) ID() string {
+	id := fmt.Sprintf("%s;%s;%s;%s",
+		r.Protocol,
+		r.DestinationPort.String(),
+		r.TranslatedAddress.String(),
+		r.TranslatedPort.String())
+	return id
+}
+
+func (r ForwardRule) String() string {
+	return fmt.Sprintf("protocol: %s, destinationPort: %s, translatedAddress: %s, translatedPort: %s", r.Protocol, r.DestinationPort.String(), r.TranslatedAddress.String(), r.TranslatedPort.String())
+}

client/firewall/manager/port.go

@@ -1,30 +1,12 @@
 package manager
 
 import (
+	"fmt"
 	"strconv"
 )
 
-// Protocol is the protocol of the port
-type Protocol string
-
-const (
-	// ProtocolTCP is the TCP protocol
-	ProtocolTCP Protocol = "tcp"
-
-	// ProtocolUDP is the UDP protocol
-	ProtocolUDP Protocol = "udp"
-
-	// ProtocolICMP is the ICMP protocol
-	ProtocolICMP Protocol = "icmp"
-
-	// ProtocolALL cover all supported protocols
-	ProtocolALL Protocol = "all"
-
-	// ProtocolUnknown unknown protocol
-	ProtocolUnknown Protocol = "unknown"
-)
-
 // Port of the address for firewall rule
+// todo Move Protocol and Port and RouterPair to the Firwall package or a separate package
 type Port struct {
 	// IsRange is true Values contains two values, the first is the start port, the second is the end port
 	IsRange bool
@@ -33,6 +15,25 @@ type Port struct {
 	Values []uint16
 }
 
+func NewPort(ports ...int) (*Port, error) {
+	if len(ports) == 0 {
+		return nil, fmt.Errorf("no port provided")
+	}
+
+	ports16 := make([]uint16, len(ports))
+	for i, port := range ports {
+		if port < 1 || port > 65535 {
+			return nil, fmt.Errorf("invalid port number: %d (must be between 1-65535)", port)
+		}
+		ports16[i] = uint16(port)
+	}
+
+	return &Port{
+		IsRange: len(ports) > 1,
+		Values:  ports16,
+	}, nil
+}
+
 // String interface implementation
 func (p *Port) String() string {
 	var ports string

client/firewall/manager/protocol.go

@@ -0,0 +1,19 @@
+package manager
+
+// Protocol is the protocol of the port
+// todo Move Protocol and Port and RouterPair to the Firwall package or a separate package
+type Protocol string
+
+const (
+	// ProtocolTCP is the TCP protocol
+	ProtocolTCP Protocol = "tcp"
+
+	// ProtocolUDP is the UDP protocol
+	ProtocolUDP Protocol = "udp"
+
+	// ProtocolICMP is the ICMP protocol
+	ProtocolICMP Protocol = "icmp"
+
+	// ProtocolALL cover all supported protocols
+	ProtocolALL Protocol = "all"
+)

client/firewall/nftables/acl_linux.go

@@ -127,7 +127,7 @@ func (m *AclManager) DeletePeerRule(rule firewall.Rule) error {
 				log.Errorf("failed to delete mangle rule: %v", err)
 			}
 		}
-		delete(m.rules, r.GetRuleID())
+		delete(m.rules, r.ID())
 		return m.rConn.Flush()
 	}
 
@@ -141,7 +141,7 @@ func (m *AclManager) DeletePeerRule(rule firewall.Rule) error {
 				log.Errorf("failed to delete mangle rule: %v", err)
 			}
 		}
-		delete(m.rules, r.GetRuleID())
+		delete(m.rules, r.ID())
 		return m.rConn.Flush()
 	}
 
@@ -176,7 +176,7 @@ func (m *AclManager) DeletePeerRule(rule firewall.Rule) error {
 		return err
 	}
 
-	delete(m.rules, r.GetRuleID())
+	delete(m.rules, r.ID())
 	m.ipsetStore.DeleteReferenceFromIpSet(r.nftSet.Name)
 
 	if m.ipsetStore.HasReferenceToSet(r.nftSet.Name) {

client/firewall/nftables/manager_linux.go

@@ -342,6 +342,22 @@ func (m *Manager) Flush() error {
 	return m.aclManager.Flush()
 }
 
+// AddDNATRule adds a DNAT rule
+func (m *Manager) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error) {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	return m.router.AddDNATRule(rule)
+}
+
+// DeleteDNATRule deletes a DNAT rule
+func (m *Manager) DeleteDNATRule(rule firewall.Rule) error {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	return m.router.DeleteDNATRule(rule)
+}
+
 func (m *Manager) createWorkTable() (*nftables.Table, error) {
 	tables, err := m.rConn.ListTablesOfFamily(nftables.TableFamilyIPv4)
 	if err != nil {

client/firewall/nftables/router_linux.go

@@ -14,23 +14,31 @@ import (
 	"github.com/google/nftables"
 	"github.com/google/nftables/binaryutil"
 	"github.com/google/nftables/expr"
+	"github.com/google/nftables/xt"
 	"github.com/hashicorp/go-multierror"
 	log "github.com/sirupsen/logrus"
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/internal/acl/id"
+	"github.com/netbirdio/netbird/client/internal/routemanager/ipfwdstate"
 	"github.com/netbirdio/netbird/client/internal/routemanager/refcounter"
 	nbnet "github.com/netbirdio/netbird/util/net"
 )
 
 const (
-	chainNameRoutingFw  = "netbird-rt-fwd"
-	chainNameRoutingNat = "netbird-rt-postrouting"
-	chainNameForward    = "FORWARD"
+	tableNat               = "nat"
+	chainNameNatPrerouting = "PREROUTING"
+	chainNameRoutingFw     = "netbird-rt-fwd"
+	chainNameRoutingNat    = "netbird-rt-postrouting"
+	chainNameRoutingRdr    = "netbird-rt-redirect"
+	chainNameForward       = "FORWARD"
 
 	userDataAcceptForwardRuleIif = "frwacceptiif"
 	userDataAcceptForwardRuleOif = "frwacceptoif"
+
+	dnatSuffix = "_dnat"
+	snatSuffix = "_snat"
 )
 
 const refreshRulesMapError = "refresh rules map: %w"
@@ -49,16 +57,18 @@ type router struct {
 	ipsetCounter *refcounter.Counter[string, []netip.Prefix, *nftables.Set]
 
 	wgIface          iFaceMapper
+	ipFwdState       *ipfwdstate.IPForwardingState
 	legacyManagement bool
 }
 
 func newRouter(workTable *nftables.Table, wgIface iFaceMapper) (*router, error) {
 	r := &router{
-		conn:      &nftables.Conn{},
-		workTable: workTable,
-		chains:    make(map[string]*nftables.Chain),
-		rules:     make(map[string]*nftables.Rule),
-		wgIface:   wgIface,
+		conn:       &nftables.Conn{},
+		workTable:  workTable,
+		chains:     make(map[string]*nftables.Chain),
+		rules:      make(map[string]*nftables.Rule),
+		wgIface:    wgIface,
+		ipFwdState: ipfwdstate.NewIPForwardingState(),
 	}
 
 	r.ipsetCounter = refcounter.New(
@@ -98,7 +108,52 @@ func (r *router) Reset() error {
 	// clear without deleting the ipsets, the nf table will be deleted by the caller
 	r.ipsetCounter.Clear()
 
-	return r.removeAcceptForwardRules()
+	var merr *multierror.Error
+
+	if err := r.removeAcceptForwardRules(); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("remove accept forward rules: %w", err))
+	}
+
+	if err := r.removeNatPreroutingRules(); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("remove filter prerouting rules: %w", err))
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *router) removeNatPreroutingRules() error {
+	table := &nftables.Table{
+		Name:   tableNat,
+		Family: nftables.TableFamilyIPv4,
+	}
+	chain := &nftables.Chain{
+		Name:     chainNameNatPrerouting,
+		Table:    table,
+		Hooknum:  nftables.ChainHookPrerouting,
+		Priority: nftables.ChainPriorityNATDest,
+		Type:     nftables.ChainTypeNAT,
+	}
+	rules, err := r.conn.GetRules(table, chain)
+	if err != nil {
+		return fmt.Errorf("get rules from nat table: %w", err)
+	}
+
+	var merr *multierror.Error
+
+	// Delete rules that have our UserData suffix
+	for _, rule := range rules {
+		if len(rule.UserData) == 0 || !strings.HasSuffix(string(rule.UserData), dnatSuffix) {
+			continue
+		}
+		if err := r.conn.DelRule(rule); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete rule %s: %w", rule.UserData, err))
+		}
+	}
+
+	if err := r.conn.Flush(); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf(flushError, err))
+	}
+	return nberrors.FormatErrorOrNil(merr)
 }
 
 func (r *router) loadFilterTable() (*nftables.Table, error) {
@@ -133,14 +188,22 @@ func (r *router) createContainers() error {
 		Type:     nftables.ChainTypeNAT,
 	})
 
+	r.chains[chainNameRoutingRdr] = r.conn.AddChain(&nftables.Chain{
+		Name:     chainNameRoutingRdr,
+		Table:    r.workTable,
+		Hooknum:  nftables.ChainHookPrerouting,
+		Priority: nftables.ChainPriorityNATDest,
+		Type:     nftables.ChainTypeNAT,
+	})
+
 	// Chain is created by acl manager
 	// TODO: move creation to a common place
 	r.chains[chainNamePrerouting] = &nftables.Chain{
 		Name:     chainNamePrerouting,
 		Table:    r.workTable,
-		Type:     nftables.ChainTypeFilter,
 		Hooknum:  nftables.ChainHookPrerouting,
 		Priority: nftables.ChainPriorityMangle,
+		Type:     nftables.ChainTypeFilter,
 	}
 
 	// Add the single NAT rule that matches on mark
@@ -281,7 +344,7 @@ func (r *router) DeleteRouteRule(rule firewall.Rule) error {
 		return fmt.Errorf(refreshRulesMapError, err)
 	}
 
-	ruleKey := rule.GetRuleID()
+	ruleKey := rule.ID()
 	nftRule, exists := r.rules[ruleKey]
 	if !exists {
 		log.Debugf("route rule %s not found", ruleKey)
@@ -410,6 +473,10 @@ func (r *router) deleteNftRule(rule *nftables.Rule, ruleKey string) error {
 
 // AddNatRule appends a nftables rule pair to the nat chain
 func (r *router) AddNatRule(pair firewall.RouterPair) error {
+	if err := r.ipFwdState.RequestForwarding(); err != nil {
+		return err
+	}
+
 	if err := r.refreshRulesMap(); err != nil {
 		return fmt.Errorf(refreshRulesMapError, err)
 	}
@@ -836,6 +903,10 @@ func (r *router) removeAcceptForwardRulesIptables(ipt *iptables.IPTables) error
 
 // RemoveNatRule removes the prerouting mark rule
 func (r *router) RemoveNatRule(pair firewall.RouterPair) error {
+	if err := r.ipFwdState.ReleaseForwarding(); err != nil {
+		log.Errorf("%v", err)
+	}
+
 	if err := r.refreshRulesMap(); err != nil {
 		return fmt.Errorf(refreshRulesMapError, err)
 	}
@@ -896,6 +967,269 @@ func (r *router) refreshRulesMap() error {
 	return nil
 }
 
+func (r *router) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error) {
+	if err := r.ipFwdState.RequestForwarding(); err != nil {
+		return nil, err
+	}
+
+	ruleKey := rule.ID()
+	if _, exists := r.rules[ruleKey+dnatSuffix]; exists {
+		return rule, nil
+	}
+
+	protoNum, err := protoToInt(rule.Protocol)
+	if err != nil {
+		return nil, fmt.Errorf("convert protocol to number: %w", err)
+	}
+
+	if err := r.addDnatRedirect(rule, protoNum, ruleKey); err != nil {
+		return nil, err
+	}
+
+	r.addDnatMasq(rule, protoNum, ruleKey)
+
+	// Unlike iptables, there's no point in adding "out" rules in the forward chain here as our policy is ACCEPT.
+	// To overcome DROP policies in other chains, we'd have to add rules to the chains there.
+	// We also cannot just add "oif <iface> accept" there and filter in our own table as we don't know what is supposed to be allowed.
+	// TODO: find chains with drop policies and add rules there
+
+	if err := r.conn.Flush(); err != nil {
+		return nil, fmt.Errorf("flush rules: %w", err)
+	}
+
+	return &rule, nil
+}
+
+func (r *router) addDnatRedirect(rule firewall.ForwardRule, protoNum uint8, ruleKey string) error {
+	dnatExprs := []expr.Any{
+		&expr.Meta{Key: expr.MetaKeyIIFNAME, Register: 1},
+		&expr.Cmp{
+			Op:       expr.CmpOpNeq,
+			Register: 1,
+			Data:     ifname(r.wgIface.Name()),
+		},
+		&expr.Meta{Key: expr.MetaKeyL4PROTO, Register: 1},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     []byte{protoNum},
+		},
+		&expr.Payload{
+			DestRegister: 1,
+			Base:         expr.PayloadBaseTransportHeader,
+			Offset:       2,
+			Len:          2,
+		},
+	}
+	dnatExprs = append(dnatExprs, applyPort(&rule.DestinationPort, false)...)
+
+	// shifted translated port is not supported in nftables, so we hand this over to xtables
+	if rule.TranslatedPort.IsRange && len(rule.TranslatedPort.Values) == 2 {
+		if rule.TranslatedPort.Values[0] != rule.DestinationPort.Values[0] ||
+			rule.TranslatedPort.Values[1] != rule.DestinationPort.Values[1] {
+			return r.addXTablesRedirect(dnatExprs, ruleKey, rule)
+		}
+	}
+
+	additionalExprs, regProtoMin, regProtoMax, err := r.handleTranslatedPort(rule)
+	if err != nil {
+		return err
+	}
+	dnatExprs = append(dnatExprs, additionalExprs...)
+
+	dnatExprs = append(dnatExprs,
+		&expr.NAT{
+			Type:        expr.NATTypeDestNAT,
+			Family:      uint32(nftables.TableFamilyIPv4),
+			RegAddrMin:  1,
+			RegProtoMin: regProtoMin,
+			RegProtoMax: regProtoMax,
+		},
+	)
+
+	dnatRule := &nftables.Rule{
+		Table:    r.workTable,
+		Chain:    r.chains[chainNameRoutingRdr],
+		Exprs:    dnatExprs,
+		UserData: []byte(ruleKey + dnatSuffix),
+	}
+	r.conn.AddRule(dnatRule)
+	r.rules[ruleKey+dnatSuffix] = dnatRule
+
+	return nil
+}
+
+func (r *router) handleTranslatedPort(rule firewall.ForwardRule) ([]expr.Any, uint32, uint32, error) {
+	switch {
+	case rule.TranslatedPort.IsRange && len(rule.TranslatedPort.Values) == 2:
+		return r.handlePortRange(rule)
+	case len(rule.TranslatedPort.Values) == 0:
+		return r.handleAddressOnly(rule)
+	case len(rule.TranslatedPort.Values) == 1:
+		return r.handleSinglePort(rule)
+	default:
+		return nil, 0, 0, fmt.Errorf("invalid translated port: %v", rule.TranslatedPort)
+	}
+}
+
+func (r *router) handlePortRange(rule firewall.ForwardRule) ([]expr.Any, uint32, uint32, error) {
+	exprs := []expr.Any{
+		&expr.Immediate{
+			Register: 1,
+			Data:     rule.TranslatedAddress.AsSlice(),
+		},
+		&expr.Immediate{
+			Register: 2,
+			Data:     binaryutil.BigEndian.PutUint16(rule.TranslatedPort.Values[0]),
+		},
+		&expr.Immediate{
+			Register: 3,
+			Data:     binaryutil.BigEndian.PutUint16(rule.TranslatedPort.Values[1]),
+		},
+	}
+	return exprs, 2, 3, nil
+}
+
+func (r *router) handleAddressOnly(rule firewall.ForwardRule) ([]expr.Any, uint32, uint32, error) {
+	exprs := []expr.Any{
+		&expr.Immediate{
+			Register: 1,
+			Data:     rule.TranslatedAddress.AsSlice(),
+		},
+	}
+	return exprs, 0, 0, nil
+}
+
+func (r *router) handleSinglePort(rule firewall.ForwardRule) ([]expr.Any, uint32, uint32, error) {
+	exprs := []expr.Any{
+		&expr.Immediate{
+			Register: 1,
+			Data:     rule.TranslatedAddress.AsSlice(),
+		},
+		&expr.Immediate{
+			Register: 2,
+			Data:     binaryutil.BigEndian.PutUint16(rule.TranslatedPort.Values[0]),
+		},
+	}
+	return exprs, 2, 0, nil
+}
+
+func (r *router) addXTablesRedirect(dnatExprs []expr.Any, ruleKey string, rule firewall.ForwardRule) error {
+	dnatExprs = append(dnatExprs,
+		&expr.Counter{},
+		&expr.Target{
+			Name: "DNAT",
+			Rev:  2,
+			Info: &xt.NatRange2{
+				NatRange: xt.NatRange{
+					Flags:   uint(xt.NatRangeMapIPs | xt.NatRangeProtoSpecified | xt.NatRangeProtoOffset),
+					MinIP:   rule.TranslatedAddress.AsSlice(),
+					MaxIP:   rule.TranslatedAddress.AsSlice(),
+					MinPort: rule.TranslatedPort.Values[0],
+					MaxPort: rule.TranslatedPort.Values[1],
+				},
+				BasePort: rule.DestinationPort.Values[0],
+			},
+		},
+	)
+
+	dnatRule := &nftables.Rule{
+		Table: &nftables.Table{
+			Name:   tableNat,
+			Family: nftables.TableFamilyIPv4,
+		},
+		Chain: &nftables.Chain{
+			Name:     chainNameNatPrerouting,
+			Table:    r.filterTable,
+			Type:     nftables.ChainTypeNAT,
+			Hooknum:  nftables.ChainHookPrerouting,
+			Priority: nftables.ChainPriorityNATDest,
+		},
+		Exprs:    dnatExprs,
+		UserData: []byte(ruleKey + dnatSuffix),
+	}
+	r.conn.AddRule(dnatRule)
+	r.rules[ruleKey+dnatSuffix] = dnatRule
+
+	return nil
+}
+
+func (r *router) addDnatMasq(rule firewall.ForwardRule, protoNum uint8, ruleKey string) {
+	masqExprs := []expr.Any{
+		&expr.Meta{Key: expr.MetaKeyOIFNAME, Register: 1},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     ifname(r.wgIface.Name()),
+		},
+		&expr.Meta{Key: expr.MetaKeyL4PROTO, Register: 1},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     []byte{protoNum},
+		},
+		&expr.Payload{
+			DestRegister: 1,
+			Base:         expr.PayloadBaseNetworkHeader,
+			Offset:       16,
+			Len:          4,
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     rule.TranslatedAddress.AsSlice(),
+		},
+	}
+
+	masqExprs = append(masqExprs, applyPort(&rule.TranslatedPort, false)...)
+	masqExprs = append(masqExprs, &expr.Masq{})
+
+	masqRule := &nftables.Rule{
+		Table:    r.workTable,
+		Chain:    r.chains[chainNameRoutingNat],
+		Exprs:    masqExprs,
+		UserData: []byte(ruleKey + snatSuffix),
+	}
+	r.conn.AddRule(masqRule)
+	r.rules[ruleKey+snatSuffix] = masqRule
+}
+
+func (r *router) DeleteDNATRule(rule firewall.Rule) error {
+	if err := r.ipFwdState.ReleaseForwarding(); err != nil {
+		log.Errorf("%v", err)
+	}
+
+	ruleKey := rule.ID()
+
+	if err := r.refreshRulesMap(); err != nil {
+		return fmt.Errorf(refreshRulesMapError, err)
+	}
+
+	var merr *multierror.Error
+	if dnatRule, exists := r.rules[ruleKey+dnatSuffix]; exists {
+		if err := r.conn.DelRule(dnatRule); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete dnat rule: %w", err))
+		}
+	}
+
+	if masqRule, exists := r.rules[ruleKey+snatSuffix]; exists {
+		if err := r.conn.DelRule(masqRule); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete snat rule: %w", err))
+		}
+	}
+
+	if err := r.conn.Flush(); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf(flushError, err))
+	}
+
+	if merr == nil {
+		delete(r.rules, ruleKey+dnatSuffix)
+		delete(r.rules, ruleKey+snatSuffix)
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
 // generateCIDRMatcherExpressions generates nftables expressions that matches a CIDR
 func generateCIDRMatcherExpressions(source bool, prefix netip.Prefix) []expr.Any {
 	var offset uint32
@@ -959,15 +1293,11 @@ func applyPort(port *firewall.Port, isSource bool) []expr.Any {
 	if port.IsRange && len(port.Values) == 2 {
 		// Handle port range
 		exprs = append(exprs,
-			&expr.Cmp{
-				Op:       expr.CmpOpGte,
+			&expr.Range{
+				Op:       expr.CmpOpEq,
 				Register: 1,
-				Data:     binaryutil.BigEndian.PutUint16(port.Values[0]),
-			},
-			&expr.Cmp{
-				Op:       expr.CmpOpLte,
-				Register: 1,
-				Data:     binaryutil.BigEndian.PutUint16(port.Values[1]),
+				FromData: binaryutil.BigEndian.PutUint16(port.Values[0]),
+				ToData:   binaryutil.BigEndian.PutUint16(port.Values[1]),
 			},
 		)
 	} else {

client/firewall/nftables/router_linux_test.go

@@ -319,7 +319,7 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 			})
 
 			// Check if the rule is in the internal map
-			rule, ok := r.rules[ruleKey.GetRuleID()]
+			rule, ok := r.rules[ruleKey.ID()]
 			assert.True(t, ok, "Rule not found in internal map")
 
 			t.Log("Internal rule expressions:")
@@ -336,7 +336,7 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 
 			var nftRule *nftables.Rule
 			for _, rule := range rules {
-				if string(rule.UserData) == ruleKey.GetRuleID() {
+				if string(rule.UserData) == ruleKey.ID() {
 					nftRule = rule
 					break
 				}
@@ -595,16 +595,20 @@ func containsPort(exprs []expr.Any, port *firewall.Port, isSource bool) bool {
 			if ex.Base == expr.PayloadBaseTransportHeader && ex.Offset == offset && ex.Len == 2 {
 				payloadFound = true
 			}
-		case *expr.Cmp:
-			if port.IsRange {
-				if ex.Op == expr.CmpOpGte || ex.Op == expr.CmpOpLte {
+		case *expr.Range:
+			if port.IsRange && len(port.Values) == 2 {
+				fromPort := binary.BigEndian.Uint16(ex.FromData)
+				toPort := binary.BigEndian.Uint16(ex.ToData)
+				if fromPort == port.Values[0] && toPort == port.Values[1] {
 					portMatchFound = true
 				}
-			} else {
+			}
+		case *expr.Cmp:
+			if !port.IsRange {
 				if ex.Op == expr.CmpOpEq && len(ex.Data) == 2 {
 					portValue := binary.BigEndian.Uint16(ex.Data)
 					for _, p := range port.Values {
-						if uint16(p) == portValue {
+						if p == portValue {
 							portMatchFound = true
 							break
 						}

client/firewall/nftables/rule_linux.go

@@ -16,6 +16,6 @@ type Rule struct {
 }
 
 // GetRuleID returns the rule id
-func (r *Rule) GetRuleID() string {
+func (r *Rule) ID() string {
 	return r.ruleID
 }

client/firewall/uspfilter/rule.go

@@ -24,8 +24,8 @@ type PeerRule struct {
 	udpHook func([]byte) bool
 }
 
-// GetRuleID returns the rule id
-func (r *PeerRule) GetRuleID() string {
+// ID returns the rule id
+func (r *PeerRule) ID() string {
 	return r.id
 }
 
@@ -39,7 +39,7 @@ type RouteRule struct {
 	action      firewall.Action
 }
 
-// GetRuleID returns the rule id
-func (r *RouteRule) GetRuleID() string {
+// ID returns the rule id
+func (r *RouteRule) ID() string {
 	return r.id
 }

client/firewall/uspfilter/uspfilter.go

@@ -42,6 +42,8 @@ const (
 	EnvEnableNetstackLocalForwarding = "NB_ENABLE_NETSTACK_LOCAL_FORWARDING"
 )
 
+var errNatNotSupported = errors.New("nat not supported with userspace firewall")
+
 // RuleSet is a set of rules grouped by a string key
 type RuleSet map[string]PeerRule
 
@@ -437,7 +439,7 @@ func (m *Manager) DeleteRouteRule(rule firewall.Rule) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	ruleID := rule.GetRuleID()
+	ruleID := rule.ID()
 	idx := slices.IndexFunc(m.routeRules, func(r RouteRule) bool {
 		return r.id == ruleID
 	})
@@ -478,6 +480,22 @@ func (m *Manager) SetLegacyManagement(isLegacy bool) error {
 // Flush doesn't need to be implemented for this manager
 func (m *Manager) Flush() error { return nil }
 
+// AddDNATRule adds a DNAT rule
+func (m *Manager) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error) {
+	if m.nativeFirewall == nil {
+		return nil, errNatNotSupported
+	}
+	return m.nativeFirewall.AddDNATRule(rule)
+}
+
+// DeleteDNATRule deletes a DNAT rule
+func (m *Manager) DeleteDNATRule(rule firewall.Rule) error {
+	if m.nativeFirewall == nil {
+		return errNatNotSupported
+	}
+	return m.nativeFirewall.DeleteDNATRule(rule)
+}
+
 // DropOutgoing filter outgoing packets
 func (m *Manager) DropOutgoing(packetData []byte) bool {
 	return m.processOutgoingHooks(packetData)

client/firewall/uspfilter/uspfilter_test.go

@@ -135,7 +135,7 @@ func TestManagerDeleteRule(t *testing.T) {
 	}
 
 	for _, r := range rule2 {
-		if _, ok := m.incomingRules[ip.String()][r.GetRuleID()]; !ok {
+		if _, ok := m.incomingRules[ip.String()][r.ID()]; !ok {
 			t.Errorf("rule2 is not in the incomingRules")
 		}
 	}
@@ -149,7 +149,7 @@ func TestManagerDeleteRule(t *testing.T) {
 	}
 
 	for _, r := range rule2 {
-		if _, ok := m.incomingRules[ip.String()][r.GetRuleID()]; ok {
+		if _, ok := m.incomingRules[ip.String()][r.ID()]; ok {
 			t.Errorf("rule2 is not in the incomingRules")
 		}
 	}