[client] Fix rule order for deny rules in peer ACLs (#4147)

client/firewall/iptables/acl_linux.go

@@ -85,7 +85,7 @@ func (m *aclManager) AddPeerFiltering(
 ) ([]firewall.Rule, error) {
 	chain := chainNameInputRules
 
-	ipsetName = transformIPsetName(ipsetName, sPort, dPort)
+	ipsetName = transformIPsetName(ipsetName, sPort, dPort, action)
 	specs := filterRuleSpecs(ip, string(protocol), sPort, dPort, action, ipsetName)
 
 	mangleSpecs := slices.Clone(specs)
@@ -135,7 +135,14 @@ func (m *aclManager) AddPeerFiltering(
 		return nil, fmt.Errorf("rule already exists")
 	}
 
-	if err := m.iptablesClient.Append(tableFilter, chain, specs...); err != nil {
+	// Insert DROP rules at the beginning, append ACCEPT rules at the end
+	if action == firewall.ActionDrop {
+		// Insert at the beginning of the chain (position 1)
+		err = m.iptablesClient.Insert(tableFilter, chain, 1, specs...)
+	} else {
+		err = m.iptablesClient.Append(tableFilter, chain, specs...)
+	}
+	if err != nil {
 		return nil, err
 	}
 
@@ -388,17 +395,25 @@ func actionToStr(action firewall.Action) string {
 	return "DROP"
 }
 
-func transformIPsetName(ipsetName string, sPort, dPort *firewall.Port) string {
-	switch {
-	case ipsetName == "":
+func transformIPsetName(ipsetName string, sPort, dPort *firewall.Port, action firewall.Action) string {
+	if ipsetName == "" {
 		return ""
+	}
+
+	// Include action in the ipset name to prevent squashing rules with different actions
+	actionSuffix := ""
+	if action == firewall.ActionDrop {
+		actionSuffix = "-drop"
+	}
+
+	switch {
 	case sPort != nil && dPort != nil:
-		return ipsetName + "-sport-dport"
+		return ipsetName + "-sport-dport" + actionSuffix
 	case sPort != nil:
-		return ipsetName + "-sport"
+		return ipsetName + "-sport" + actionSuffix
 	case dPort != nil:
-		return ipsetName + "-dport"
+		return ipsetName + "-dport" + actionSuffix
 	default:
-		return ipsetName
+		return ipsetName + actionSuffix
 	}
 }

client/firewall/iptables/manager_linux_test.go

@@ -3,6 +3,7 @@ package iptables
 import (
 	"fmt"
 	"net/netip"
+	"strings"
 	"testing"
 	"time"
 
@@ -15,7 +16,7 @@ import (
 
 var ifaceMock = &iFaceMock{
 	NameFunc: func() string {
-		return "lo"
+		return "wg-test"
 	},
 	AddressFunc: func() wgaddr.Address {
 		return wgaddr.Address{
@@ -109,10 +110,84 @@ func TestIptablesManager(t *testing.T) {
 	})
 }
 
+func TestIptablesManagerDenyRules(t *testing.T) {
+	ipv4Client, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
+	require.NoError(t, err)
+
+	manager, err := Create(ifaceMock)
+	require.NoError(t, err)
+	require.NoError(t, manager.Init(nil))
+
+	defer func() {
+		err := manager.Close(nil)
+		require.NoError(t, err)
+	}()
+
+	t.Run("add deny rule", func(t *testing.T) {
+		ip := netip.MustParseAddr("10.20.0.3")
+		port := &fw.Port{Values: []uint16{22}}
+
+		rule, err := manager.AddPeerFiltering(nil, ip.AsSlice(), "tcp", nil, port, fw.ActionDrop, "deny-ssh")
+		require.NoError(t, err, "failed to add deny rule")
+		require.NotEmpty(t, rule, "deny rule should not be empty")
+
+		// Verify the rule was added by checking iptables
+		for _, r := range rule {
+			rr := r.(*Rule)
+			checkRuleSpecs(t, ipv4Client, rr.chain, true, rr.specs...)
+		}
+	})
+
+	t.Run("deny rule precedence test", func(t *testing.T) {
+		ip := netip.MustParseAddr("10.20.0.4")
+		port := &fw.Port{Values: []uint16{80}}
+
+		// Add accept rule first
+		_, err := manager.AddPeerFiltering(nil, ip.AsSlice(), "tcp", nil, port, fw.ActionAccept, "accept-http")
+		require.NoError(t, err, "failed to add accept rule")
+
+		// Add deny rule second for same IP/port - this should take precedence
+		_, err = manager.AddPeerFiltering(nil, ip.AsSlice(), "tcp", nil, port, fw.ActionDrop, "deny-http")
+		require.NoError(t, err, "failed to add deny rule")
+
+		// Inspect the actual iptables rules to verify deny rule comes before accept rule
+		rules, err := ipv4Client.List("filter", chainNameInputRules)
+		require.NoError(t, err, "failed to list iptables rules")
+
+		// Debug: print all rules
+		t.Logf("All iptables rules in chain %s:", chainNameInputRules)
+		for i, rule := range rules {
+			t.Logf("  [%d] %s", i, rule)
+		}
+
+		var denyRuleIndex, acceptRuleIndex int = -1, -1
+		for i, rule := range rules {
+			if strings.Contains(rule, "DROP") {
+				t.Logf("Found DROP rule at index %d: %s", i, rule)
+				if strings.Contains(rule, "deny-http") && strings.Contains(rule, "80") {
+					denyRuleIndex = i
+				}
+			}
+			if strings.Contains(rule, "ACCEPT") {
+				t.Logf("Found ACCEPT rule at index %d: %s", i, rule)
+				if strings.Contains(rule, "accept-http") && strings.Contains(rule, "80") {
+					acceptRuleIndex = i
+				}
+			}
+		}
+
+		require.NotEqual(t, -1, denyRuleIndex, "deny rule should exist in iptables")
+		require.NotEqual(t, -1, acceptRuleIndex, "accept rule should exist in iptables")
+		require.Less(t, denyRuleIndex, acceptRuleIndex,
+			"deny rule should come before accept rule in iptables chain (deny at index %d, accept at index %d)",
+			denyRuleIndex, acceptRuleIndex)
+	})
+}
+
 func TestIptablesManagerIPSet(t *testing.T) {
 	mock := &iFaceMock{
 		NameFunc: func() string {
-			return "lo"
+			return "wg-test"
 		},
 		AddressFunc: func() wgaddr.Address {
 			return wgaddr.Address{
@@ -176,7 +251,7 @@ func checkRuleSpecs(t *testing.T, ipv4Client *iptables.IPTables, chainName strin
 func TestIptablesCreatePerformance(t *testing.T) {
 	mock := &iFaceMock{
 		NameFunc: func() string {
-			return "lo"
+			return "wg-test"
 		},
 		AddressFunc: func() wgaddr.Address {
 			return wgaddr.Address{

client/firewall/nftables/acl_linux.go

@@ -341,30 +341,38 @@ func (m *AclManager) addIOFiltering(
 	userData := []byte(ruleId)
 
 	chain := m.chainInputRules
-	nftRule := m.rConn.AddRule(&nftables.Rule{
+	rule := &nftables.Rule{
 		Table:    m.workTable,
 		Chain:    chain,
 		Exprs:    mainExpressions,
 		UserData: userData,
-	})
+	}
+
+	// Insert DROP rules at the beginning, append ACCEPT rules at the end
+	var nftRule *nftables.Rule
+	if action == firewall.ActionDrop {
+		nftRule = m.rConn.InsertRule(rule)
+	} else {
+		nftRule = m.rConn.AddRule(rule)
+	}
 
 	if err := m.rConn.Flush(); err != nil {
 		return nil, fmt.Errorf(flushError, err)
 	}
 
-	rule := &Rule{
+	ruleStruct := &Rule{
 		nftRule:    nftRule,
 		mangleRule: m.createPreroutingRule(expressions, userData),
 		nftSet:     ipset,
 		ruleID:     ruleId,
 		ip:         ip,
 	}
-	m.rules[ruleId] = rule
+	m.rules[ruleId] = ruleStruct
 	if ipset != nil {
 		m.ipsetStore.AddReferenceToIpset(ipset.Name)
 	}
 
-	return rule, nil
+	return ruleStruct, nil
 }
 
 func (m *AclManager) createPreroutingRule(expressions []expr.Any, userData []byte) *nftables.Rule {

client/firewall/nftables/manager_linux_test.go

@@ -2,6 +2,7 @@ package nftables
 
 import (
 	"bytes"
+	"encoding/binary"
 	"fmt"
 	"net/netip"
 	"os/exec"
@@ -20,7 +21,7 @@ import (
 
 var ifaceMock = &iFaceMock{
 	NameFunc: func() string {
-		return "lo"
+		return "wg-test"
 	},
 	AddressFunc: func() wgaddr.Address {
 		return wgaddr.Address{
@@ -103,9 +104,8 @@ func TestNftablesManager(t *testing.T) {
 			Kind: expr.VerdictAccept,
 		},
 	}
-	compareExprsIgnoringCounters(t, rules[0].Exprs, expectedExprs1)
-
-	expectedExprs2 := []expr.Any{
+	// Since DROP rules are inserted at position 0, the DROP rule comes first
+	expectedDropExprs := []expr.Any{
 		&expr.Payload{
 			DestRegister: 1,
 			Base:         expr.PayloadBaseNetworkHeader,
@@ -141,7 +141,12 @@ func TestNftablesManager(t *testing.T) {
 		},
 		&expr.Verdict{Kind: expr.VerdictDrop},
 	}
-	require.ElementsMatch(t, rules[1].Exprs, expectedExprs2, "expected the same expressions")
+
+	// Compare DROP rule at position 0 (inserted first due to InsertRule)
+	compareExprsIgnoringCounters(t, rules[0].Exprs, expectedDropExprs)
+
+	// Compare connection tracking rule at position 1 (pushed down by DROP rule insertion)
+	compareExprsIgnoringCounters(t, rules[1].Exprs, expectedExprs1)
 
 	for _, r := range rule {
 		err = manager.DeletePeerRule(r)
@@ -160,10 +165,90 @@ func TestNftablesManager(t *testing.T) {
 	require.NoError(t, err, "failed to reset")
 }
 
+func TestNftablesManagerRuleOrder(t *testing.T) {
+	// This test verifies rule insertion order in nftables peer ACLs
+	// We add accept rule first, then deny rule to test ordering behavior
+	manager, err := Create(ifaceMock)
+	require.NoError(t, err)
+	require.NoError(t, manager.Init(nil))
+
+	defer func() {
+		err = manager.Close(nil)
+		require.NoError(t, err)
+	}()
+
+	ip := netip.MustParseAddr("100.96.0.2").Unmap()
+	testClient := &nftables.Conn{}
+
+	// Add accept rule first
+	_, err = manager.AddPeerFiltering(nil, ip.AsSlice(), fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionAccept, "accept-http")
+	require.NoError(t, err, "failed to add accept rule")
+
+	// Add deny rule second for the same traffic
+	_, err = manager.AddPeerFiltering(nil, ip.AsSlice(), fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionDrop, "deny-http")
+	require.NoError(t, err, "failed to add deny rule")
+
+	err = manager.Flush()
+	require.NoError(t, err, "failed to flush")
+
+	rules, err := testClient.GetRules(manager.aclManager.workTable, manager.aclManager.chainInputRules)
+	require.NoError(t, err, "failed to get rules")
+
+	t.Logf("Found %d rules in nftables chain", len(rules))
+
+	// Find the accept and deny rules and verify deny comes before accept
+	var acceptRuleIndex, denyRuleIndex int = -1, -1
+	for i, rule := range rules {
+		hasAcceptHTTPSet := false
+		hasDenyHTTPSet := false
+		hasPort80 := false
+		var action string
+
+		for _, e := range rule.Exprs {
+			// Check for set lookup
+			if lookup, ok := e.(*expr.Lookup); ok {
+				if lookup.SetName == "accept-http" {
+					hasAcceptHTTPSet = true
+				} else if lookup.SetName == "deny-http" {
+					hasDenyHTTPSet = true
+				}
+			}
+			// Check for port 80
+			if cmp, ok := e.(*expr.Cmp); ok {
+				if cmp.Op == expr.CmpOpEq && len(cmp.Data) == 2 && binary.BigEndian.Uint16(cmp.Data) == 80 {
+					hasPort80 = true
+				}
+			}
+			// Check for verdict
+			if verdict, ok := e.(*expr.Verdict); ok {
+				if verdict.Kind == expr.VerdictAccept {
+					action = "ACCEPT"
+				} else if verdict.Kind == expr.VerdictDrop {
+					action = "DROP"
+				}
+			}
+		}
+
+		if hasAcceptHTTPSet && hasPort80 && action == "ACCEPT" {
+			t.Logf("Rule [%d]: accept-http set + Port 80 + ACCEPT", i)
+			acceptRuleIndex = i
+		} else if hasDenyHTTPSet && hasPort80 && action == "DROP" {
+			t.Logf("Rule [%d]: deny-http set + Port 80 + DROP", i)
+			denyRuleIndex = i
+		}
+	}
+
+	require.NotEqual(t, -1, acceptRuleIndex, "accept rule should exist in nftables")
+	require.NotEqual(t, -1, denyRuleIndex, "deny rule should exist in nftables")
+	require.Less(t, denyRuleIndex, acceptRuleIndex,
+		"deny rule should come before accept rule in nftables chain (deny at index %d, accept at index %d)",
+		denyRuleIndex, acceptRuleIndex)
+}
+
 func TestNFtablesCreatePerformance(t *testing.T) {
 	mock := &iFaceMock{
 		NameFunc: func() string {
-			return "lo"
+			return "wg-test"
 		},
 		AddressFunc: func() wgaddr.Address {
 			return wgaddr.Address{

client/firewall/uspfilter/allow_netbird.go

@@ -18,6 +18,7 @@ func (m *Manager) Close(stateManager *statemanager.Manager) error {
 	defer m.mutex.Unlock()
 
 	m.outgoingRules = make(map[netip.Addr]RuleSet)
+	m.incomingDenyRules = make(map[netip.Addr]RuleSet)
 	m.incomingRules = make(map[netip.Addr]RuleSet)
 
 	if m.udpTracker != nil {

client/firewall/uspfilter/allow_netbird_windows.go

@@ -27,6 +27,7 @@ func (m *Manager) Close(*statemanager.Manager) error {
 	defer m.mutex.Unlock()
 
 	m.outgoingRules = make(map[netip.Addr]RuleSet)
+	m.incomingDenyRules = make(map[netip.Addr]RuleSet)
 	m.incomingRules = make(map[netip.Addr]RuleSet)
 
 	if m.udpTracker != nil {

client/firewall/uspfilter/filter.go

@@ -70,14 +70,13 @@ func (r RouteRules) Sort() {
 
 // Manager userspace firewall manager
 type Manager struct {
-	// outgoingRules is used for hooks only
-	outgoingRules map[netip.Addr]RuleSet
-	// incomingRules is used for filtering and hooks
-	incomingRules  map[netip.Addr]RuleSet
-	routeRules     RouteRules
-	decoders       sync.Pool
-	wgIface        common.IFaceMapper
-	nativeFirewall firewall.Manager
+	outgoingRules     map[netip.Addr]RuleSet
+	incomingDenyRules map[netip.Addr]RuleSet
+	incomingRules     map[netip.Addr]RuleSet
+	routeRules        RouteRules
+	decoders          sync.Pool
+	wgIface           common.IFaceMapper
+	nativeFirewall    firewall.Manager
 
 	mutex sync.RWMutex
 
@@ -186,6 +185,7 @@ func create(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableSe
 		},
 		nativeFirewall:      nativeFirewall,
 		outgoingRules:       make(map[netip.Addr]RuleSet),
+		incomingDenyRules:   make(map[netip.Addr]RuleSet),
 		incomingRules:       make(map[netip.Addr]RuleSet),
 		wgIface:             iface,
 		localipmanager:      newLocalIPManager(),
@@ -417,10 +417,17 @@ func (m *Manager) AddPeerFiltering(
 	}
 
 	m.mutex.Lock()
-	if _, ok := m.incomingRules[r.ip]; !ok {
-		m.incomingRules[r.ip] = make(RuleSet)
+	var targetMap map[netip.Addr]RuleSet
+	if r.drop {
+		targetMap = m.incomingDenyRules
+	} else {
+		targetMap = m.incomingRules
 	}
-	m.incomingRules[r.ip][r.id] = r
+
+	if _, ok := targetMap[r.ip]; !ok {
+		targetMap[r.ip] = make(RuleSet)
+	}
+	targetMap[r.ip][r.id] = r
 	m.mutex.Unlock()
 	return []firewall.Rule{&r}, nil
 }
@@ -507,10 +514,24 @@ func (m *Manager) DeletePeerRule(rule firewall.Rule) error {
 		return fmt.Errorf("delete rule: invalid rule type: %T", rule)
 	}
 
-	if _, ok := m.incomingRules[r.ip][r.id]; !ok {
+	var sourceMap map[netip.Addr]RuleSet
+	if r.drop {
+		sourceMap = m.incomingDenyRules
+	} else {
+		sourceMap = m.incomingRules
+	}
+
+	if ruleset, ok := sourceMap[r.ip]; ok {
+		if _, exists := ruleset[r.id]; !exists {
+			return fmt.Errorf("delete rule: no rule with such id: %v", r.id)
+		}
+		delete(ruleset, r.id)
+		if len(ruleset) == 0 {
+			delete(sourceMap, r.ip)
+		}
+	} else {
 		return fmt.Errorf("delete rule: no rule with such id: %v", r.id)
 	}
-	delete(m.incomingRules[r.ip], r.id)
 
 	return nil
 }
@@ -572,7 +593,7 @@ func (m *Manager) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {
 	return nil
 }
 
-// FilterOutBound filters outgoing packets
+// FilterOutbound filters outgoing packets
 func (m *Manager) FilterOutbound(packetData []byte, size int) bool {
 	return m.filterOutbound(packetData, size)
 }
@@ -761,7 +782,7 @@ func (m *Manager) filterInbound(packetData []byte, size int) bool {
 // handleLocalTraffic handles local traffic.
 // If it returns true, the packet should be dropped.
 func (m *Manager) handleLocalTraffic(d *decoder, srcIP, dstIP netip.Addr, packetData []byte, size int) bool {
-	ruleID, blocked := m.peerACLsBlock(srcIP, packetData, m.incomingRules, d)
+	ruleID, blocked := m.peerACLsBlock(srcIP, d, packetData)
 	if blocked {
 		_, pnum := getProtocolFromPacket(d)
 		srcPort, dstPort := getPortsFromPacket(d)
@@ -971,26 +992,28 @@ func (m *Manager) isSpecialICMP(d *decoder) bool {
 		icmpType == layers.ICMPv4TypeTimeExceeded
 }
 
-func (m *Manager) peerACLsBlock(srcIP netip.Addr, packetData []byte, rules map[netip.Addr]RuleSet, d *decoder) ([]byte, bool) {
+func (m *Manager) peerACLsBlock(srcIP netip.Addr, d *decoder, packetData []byte) ([]byte, bool) {
 	m.mutex.RLock()
 	defer m.mutex.RUnlock()
+
 	if m.isSpecialICMP(d) {
 		return nil, false
 	}
 
-	if mgmtId, filter, ok := validateRule(srcIP, packetData, rules[srcIP], d); ok {
+	if mgmtId, filter, ok := validateRule(srcIP, packetData, m.incomingDenyRules[srcIP], d); ok {
 		return mgmtId, filter
 	}
 
-	if mgmtId, filter, ok := validateRule(srcIP, packetData, rules[netip.IPv4Unspecified()], d); ok {
+	if mgmtId, filter, ok := validateRule(srcIP, packetData, m.incomingRules[srcIP], d); ok {
+		return mgmtId, filter
+	}
+	if mgmtId, filter, ok := validateRule(srcIP, packetData, m.incomingRules[netip.IPv4Unspecified()], d); ok {
+		return mgmtId, filter
+	}
+	if mgmtId, filter, ok := validateRule(srcIP, packetData, m.incomingRules[netip.IPv6Unspecified()], d); ok {
 		return mgmtId, filter
 	}
 
-	if mgmtId, filter, ok := validateRule(srcIP, packetData, rules[netip.IPv6Unspecified()], d); ok {
-		return mgmtId, filter
-	}
-
-	// Default policy: DROP ALL
 	return nil, true
 }
 
@@ -1013,6 +1036,7 @@ func portsMatch(rulePort *firewall.Port, packetPort uint16) bool {
 
 func validateRule(ip netip.Addr, packetData []byte, rules map[string]PeerRule, d *decoder) ([]byte, bool, bool) {
 	payloadLayer := d.decoded[1]
+
 	for _, rule := range rules {
 		if rule.matchByIP && ip.Compare(rule.ip) != 0 {
 			continue
@@ -1045,6 +1069,7 @@ func validateRule(ip netip.Addr, packetData []byte, rules map[string]PeerRule, d
 			return rule.mgmtId, rule.drop, true
 		}
 	}
+
 	return nil, false, false
 }
 
@@ -1116,6 +1141,7 @@ func (m *Manager) AddUDPPacketHook(in bool, ip netip.Addr, dPort uint16, hook fu
 
 	m.mutex.Lock()
 	if in {
+		// Incoming UDP hooks are stored in allow rules map
 		if _, ok := m.incomingRules[r.ip]; !ok {
 			m.incomingRules[r.ip] = make(map[string]PeerRule)
 		}
@@ -1136,6 +1162,7 @@ func (m *Manager) RemovePacketHook(hookID string) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
+	// Check incoming hooks (stored in allow rules)
 	for _, arr := range m.incomingRules {
 		for _, r := range arr {
 			if r.id == hookID {
@@ -1144,6 +1171,7 @@ func (m *Manager) RemovePacketHook(hookID string) error {
 			}
 		}
 	}
+	// Check outgoing hooks
 	for _, arr := range m.outgoingRules {
 		for _, r := range arr {
 			if r.id == hookID {

client/firewall/uspfilter/filter_filter_test.go

@@ -458,6 +458,31 @@ func TestPeerACLFiltering(t *testing.T) {
 			ruleAction:      fw.ActionDrop,
 			shouldBeBlocked: true,
 		},
+		{
+			name:            "Peer ACL - Drop rule should override accept all rule",
+			srcIP:           "100.10.0.1",
+			dstIP:           "100.10.0.100",
+			proto:           fw.ProtocolTCP,
+			srcPort:         12345,
+			dstPort:         22,
+			ruleIP:          "100.10.0.1",
+			ruleProto:       fw.ProtocolTCP,
+			ruleDstPort:     &fw.Port{Values: []uint16{22}},
+			ruleAction:      fw.ActionDrop,
+			shouldBeBlocked: true,
+		},
+		{
+			name:            "Peer ACL - Drop all traffic from specific IP",
+			srcIP:           "100.10.0.99",
+			dstIP:           "100.10.0.100",
+			proto:           fw.ProtocolTCP,
+			srcPort:         12345,
+			dstPort:         80,
+			ruleIP:          "100.10.0.99",
+			ruleProto:       fw.ProtocolALL,
+			ruleAction:      fw.ActionDrop,
+			shouldBeBlocked: true,
+		},
 	}
 
 	t.Run("Implicit DROP (no rules)", func(t *testing.T) {
@@ -468,13 +493,11 @@ func TestPeerACLFiltering(t *testing.T) {
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
-
 			if tc.ruleAction == fw.ActionDrop {
-				// add general accept rule to test drop rule
-				// TODO: this only works because 0.0.0.0 is tested last, we need to implement order
+				// add general accept rule for the same IP to test drop rule precedence
 				rules, err := manager.AddPeerFiltering(
 					nil,
-					net.ParseIP("0.0.0.0"),
+					net.ParseIP(tc.ruleIP),
 					fw.ProtocolALL,
 					nil,
 					nil,

client/firewall/uspfilter/filter_test.go

@@ -136,9 +136,22 @@ func TestManagerDeleteRule(t *testing.T) {
 		return
 	}
 
+	// Check rules exist in appropriate maps
 	for _, r := range rule2 {
-		if _, ok := m.incomingRules[ip][r.ID()]; !ok {
-			t.Errorf("rule2 is not in the incomingRules")
+		peerRule, ok := r.(*PeerRule)
+		if !ok {
+			t.Errorf("rule should be a PeerRule")
+			continue
+		}
+		// Check if rule exists in deny or allow maps based on action
+		var found bool
+		if peerRule.drop {
+			_, found = m.incomingDenyRules[ip][r.ID()]
+		} else {
+			_, found = m.incomingRules[ip][r.ID()]
+		}
+		if !found {
+			t.Errorf("rule2 is not in the expected rules map")
 		}
 	}
 
@@ -150,9 +163,22 @@ func TestManagerDeleteRule(t *testing.T) {
 		}
 	}
 
+	// Check rules are removed from appropriate maps
 	for _, r := range rule2 {
-		if _, ok := m.incomingRules[ip][r.ID()]; ok {
-			t.Errorf("rule2 is not in the incomingRules")
+		peerRule, ok := r.(*PeerRule)
+		if !ok {
+			t.Errorf("rule should be a PeerRule")
+			continue
+		}
+		// Check if rule is removed from deny or allow maps based on action
+		var found bool
+		if peerRule.drop {
+			_, found = m.incomingDenyRules[ip][r.ID()]
+		} else {
+			_, found = m.incomingRules[ip][r.ID()]
+		}
+		if found {
+			t.Errorf("rule2 should be removed from the rules map")
 		}
 	}
 }
@@ -196,16 +222,17 @@ func TestAddUDPPacketHook(t *testing.T) {
 
 			var addedRule PeerRule
 			if tt.in {
+				// Incoming UDP hooks are stored in allow rules map
 				if len(manager.incomingRules[tt.ip]) != 1 {
-					t.Errorf("expected 1 incoming rule, got %d", len(manager.incomingRules))
+					t.Errorf("expected 1 incoming rule, got %d", len(manager.incomingRules[tt.ip]))
 					return
 				}
 				for _, rule := range manager.incomingRules[tt.ip] {
 					addedRule = rule
 				}
 			} else {
-				if len(manager.outgoingRules) != 1 {
-					t.Errorf("expected 1 outgoing rule, got %d", len(manager.outgoingRules))
+				if len(manager.outgoingRules[tt.ip]) != 1 {
+					t.Errorf("expected 1 outgoing rule, got %d", len(manager.outgoingRules[tt.ip]))
 					return
 				}
 				for _, rule := range manager.outgoingRules[tt.ip] {
@@ -261,8 +288,8 @@ func TestManagerReset(t *testing.T) {
 		return
 	}
 
-	if len(m.outgoingRules) != 0 || len(m.incomingRules) != 0 {
-		t.Errorf("rules is not empty")
+	if len(m.outgoingRules) != 0 || len(m.incomingRules) != 0 || len(m.incomingDenyRules) != 0 {
+		t.Errorf("rules are not empty")
 	}
 }
 

client/firewall/uspfilter/tracer.go

@@ -314,7 +314,7 @@ func (m *Manager) buildConntrackStateMessage(d *decoder) string {
 func (m *Manager) handleLocalDelivery(trace *PacketTrace, packetData []byte, d *decoder, srcIP, dstIP netip.Addr) bool {
 	trace.AddResult(StageRouting, "Packet destined for local delivery", true)
 
-	ruleId, blocked := m.peerACLsBlock(srcIP, packetData, m.incomingRules, d)
+	ruleId, blocked := m.peerACLsBlock(srcIP, d, packetData)
 
 	strRuleId := "<no id>"
 	if ruleId != nil {