Add default firewall rules and fix tests in the github flow.

.github/workflows/golang-test-linux.yml

@@ -72,7 +72,7 @@ jobs:
         run: go test -c -o routemanager-testing.bin ./client/internal/routemanager/...
 
       - name: Generate Engine Test bin
-        run: go test -c -o engine-testing.bin ./client/internal/*.go
+        run: go test -c -o engine-testing.bin ./client/internal
 
       - name: Generate Peer Test bin
         run: go test -c -o peer-testing.bin ./client/internal/peer/...
@@ -89,4 +89,4 @@ jobs:
         run: docker run -t --cap-add=NET_ADMIN --privileged --rm -v $PWD:/ci -w /ci/client/internal --entrypoint /busybox/sh gcr.io/distroless/base:debug -c /ci/engine-testing.bin  -test.timeout 5m -test.parallel 1
 
       - name: Run Peer tests in docker
-        run: docker run -t --cap-add=NET_ADMIN --privileged --rm -v $PWD:/ci -w /ci/client/internal/peer  --entrypoint /busybox/sh gcr.io/distroless/base:debug -c /ci/peer-testing.bin  -test.timeout 5m -test.parallel 1
+        run: docker run -t --cap-add=NET_ADMIN --privileged --rm -v $PWD:/ci -w /ci/client/internal/peer  --entrypoint /busybox/sh gcr.io/distroless/base:debug -c /ci/peer-testing.bin  -test.timeout 5m -test.parallel 1

client/firewall/iptables/manager_linux.go

@@ -10,6 +10,7 @@ import (
 	"github.com/google/uuid"
 
 	fw "github.com/netbirdio/netbird/client/firewall"
+	log "github.com/sirupsen/logrus"
 )
 
 const (
@@ -17,17 +18,30 @@ const (
 	ChainFilterName = "NETBIRD-ACL"
 )
 
+// jumpNetbirdDefaultRule always added by manager to the input chain for all trafic from the Netbird interface
+var jumpNetbirdDefaultRule = []string{
+	"-j", ChainFilterName, "-m", "comment", "--comment", "Netbird traffic chain jump"}
+
+// pingSupportDefaultRule always added by the manager to the Netbird ACL chain
+var pingSupportDefaultRule = []string{
+	"-p", "icmp", "--icmp-type", "echo-request", "-j",
+	"ACCEPT", "-m", "comment", "--comment", "Allow pings from the Netbird Devices"}
+
 // Manager of iptables firewall
 type Manager struct {
 	mutex sync.Mutex
 
 	ipv4Client *iptables.IPTables
 	ipv6Client *iptables.IPTables
+
+	wgIfaceName string
 }
 
 // Create iptables firewall manager
-func Create() (*Manager, error) {
+func Create(wgIfaceName string) (*Manager, error) {
-	m := &Manager{}
+	m := &Manager{
+		wgIfaceName: wgIfaceName,
+	}
 
 	// init clients for booth ipv4 and ipv6
 	ipv4Client, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
@@ -38,14 +52,14 @@ func Create() (*Manager, error) {
 
 	ipv6Client, err := iptables.NewWithProtocol(iptables.ProtocolIPv6)
 	if err != nil {
-		return nil, fmt.Errorf("ip6tables is not installed in the system or not supported")
+		log.Errorf("ip6tables is not installed in the system or not supported")
+	} else {
+		m.ipv6Client = ipv6Client
 	}
-	m.ipv6Client = ipv6Client
 
 	if err := m.Reset(); err != nil {
-		return nil, fmt.Errorf("failed to reset firewall: %s", err)
+		return nil, fmt.Errorf("failed to reset firewall: %v", err)
 	}
-
 	return m, nil
 }
 
@@ -63,7 +77,7 @@ func (m *Manager) AddFiltering(
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	client, err := m.clientWithChain(ip)
+	client, err := m.client(ip)
 	if err != nil {
 		return nil, err
 	}
@@ -89,7 +103,16 @@ func (m *Manager) AddFiltering(
 		action,
 		comment,
 	)
-	if err := client.AppendUnique("filter", ChainFilterName, specs...); err != nil {
+
+	ok, err := client.Exists("filter", ChainFilterName, specs...)
+	if err != nil {
+		return nil, fmt.Errorf("check is rule already exists: %w", err)
+	}
+	if ok {
+		return nil, fmt.Errorf("rule already exists")
+	}
+
+	if err := client.Insert("filter", ChainFilterName, 1, specs...); err != nil {
 		return nil, err
 	}
 
@@ -100,12 +123,17 @@ func (m *Manager) AddFiltering(
 func (m *Manager) DeleteRule(rule fw.Rule) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
+
 	r, ok := rule.(*Rule)
 	if !ok {
 		return fmt.Errorf("invalid rule type")
 	}
+
 	client := m.ipv4Client
 	if r.v6 {
+		if m.ipv6Client == nil {
+			return fmt.Errorf("ipv6 is not supported")
+		}
 		client = m.ipv6Client
 	}
 	return client.Delete("filter", ChainFilterName, r.specs...)
@@ -115,11 +143,14 @@ func (m *Manager) DeleteRule(rule fw.Rule) error {
 func (m *Manager) Reset() error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
+
 	if err := m.reset(m.ipv4Client, "filter", ChainFilterName); err != nil {
 		return fmt.Errorf("clean ipv4 firewall ACL chain: %w", err)
 	}
-	if err := m.reset(m.ipv6Client, "filter", ChainFilterName); err != nil {
+	if m.ipv6Client != nil {
-		return fmt.Errorf("clean ipv6 firewall ACL chain: %w", err)
+		if err := m.reset(m.ipv6Client, "filter", ChainFilterName); err != nil {
+			return fmt.Errorf("clean ipv6 firewall ACL chain: %w", err)
+		}
 	}
 	return nil
 }
@@ -133,10 +164,13 @@ func (m *Manager) reset(client *iptables.IPTables, table, chain string) error {
 	if !ok {
 		return nil
 	}
-	if err := client.ClearChain(table, ChainFilterName); err != nil {
+
-		return fmt.Errorf("failed to clear chain: %w", err)
+	specs := append([]string{"-i", m.wgIfaceName}, jumpNetbirdDefaultRule...)
+	if err := client.Delete("filter", "INPUT", specs...); err != nil {
+		return fmt.Errorf("failed to delete default rule: %w", err)
 	}
-	return client.DeleteChain(table, ChainFilterName)
+
+	return client.ClearAndDeleteChain(table, chain)
 }
 
 // filterRuleSpecs returns the specs of a filtering rule
@@ -158,31 +192,43 @@ func (m *Manager) filterRuleSpecs(
 	return append(specs, "-m", "comment", "--comment", comment)
 }
 
-// client returns corresponding iptables client for the given ip
+// rawClient returns corresponding iptables client for the given ip
-func (m *Manager) client(ip net.IP) *iptables.IPTables {
+func (m *Manager) rawClient(ip net.IP) (*iptables.IPTables, error) {
 	if ip.To4() != nil {
-		return m.ipv4Client
+		return m.ipv4Client, nil
 	}
-	return m.ipv6Client
+	if m.ipv6Client == nil {
+		return nil, fmt.Errorf("ipv6 is not supported")
+	}
+	return m.ipv6Client, nil
 }
 
-// clientWithChain returns client with initialized chain and default rules
+// client returns client with initialized chain and default rules
-func (m *Manager) clientWithChain(ip net.IP) (*iptables.IPTables, error) {
+func (m *Manager) client(ip net.IP) (*iptables.IPTables, error) {
-	client := m.client(ip)
+	client, err := m.rawClient(ip)
+	if err != nil {
+		return nil, err
+	}
+
 	ok, err := client.ChainExists("filter", ChainFilterName)
 	if err != nil {
-		return nil, fmt.Errorf("failed to check if chain exists: %s", err)
+		return nil, fmt.Errorf("failed to check if chain exists: %w", err)
 	}
 
 	if !ok {
 		if err := client.NewChain("filter", ChainFilterName); err != nil {
-			return nil, fmt.Errorf("failed to create chain: %s", err)
+			return nil, fmt.Errorf("failed to create chain: %w", err)
 		}
 
-		specs := []string{"-p", "icmp", "--icmp-type", "echo-request", "-j", "ACCEPT"}
+		if err := client.AppendUnique("filter", ChainFilterName, pingSupportDefaultRule...); err != nil {
-		if err := client.Insert("input", ChainFilterName, 1, specs...); err != nil {
+			return nil, fmt.Errorf("failed to create default ping allow rule: %w", err)
-			return nil, fmt.Errorf("failed to create chain: %s", err)
 		}
+
+		specs := append([]string{"-i", m.wgIfaceName}, jumpNetbirdDefaultRule...)
+		if err := client.AppendUnique("filter", "INPUT", specs...); err != nil {
+			return nil, fmt.Errorf("failed to create chain: %w", err)
+		}
+
 	}
 	return client, nil
 }

client/firewall/iptables/manager_linux_test.go

@@ -14,7 +14,8 @@ func TestNewManager(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	manager, err := Create()
+	// just check on the local interface
+	manager, err := Create("lo")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -26,6 +27,7 @@ func TestNewManager(t *testing.T) {
 		rule1, err = manager.AddFiltering(ip, "tcp", port, fw.DirectionDst, fw.ActionAccept, "accept HTTP traffic")
 		if err != nil {
 			t.Errorf("failed to add rule: %v", err)
+			return
 		}
 
 		checkRuleSpecs(t, ipv4Client, true, rule1.(*Rule).specs...)
@@ -41,6 +43,7 @@ func TestNewManager(t *testing.T) {
 			ip, "tcp", port, fw.DirectionDst, fw.ActionAccept, "accept HTTPS traffic from ports range")
 		if err != nil {
 			t.Errorf("failed to add rule: %v", err)
+			return
 		}
 
 		checkRuleSpecs(t, ipv4Client, true, rule2.(*Rule).specs...)
@@ -57,6 +60,7 @@ func TestNewManager(t *testing.T) {
 	t.Run("delete second rule", func(t *testing.T) {
 		if err := manager.DeleteRule(rule2); err != nil {
 			t.Errorf("failed to delete rule: %v", err)
+			return
 		}
 
 		checkRuleSpecs(t, ipv4Client, false, rule2.(*Rule).specs...)
@@ -69,15 +73,18 @@ func TestNewManager(t *testing.T) {
 		_, err = manager.AddFiltering(ip, "udp", port, fw.DirectionDst, fw.ActionAccept, "accept Fake DNS traffic")
 		if err != nil {
 			t.Errorf("failed to add rule: %v", err)
+			return
 		}
 
 		if err := manager.Reset(); err != nil {
 			t.Errorf("failed to reset: %v", err)
+			return
 		}
 
 		ok, err := ipv4Client.ChainExists("filter", ChainFilterName)
 		if err != nil {
 			t.Errorf("failed to drop chain: %v", err)
+			return
 		}
 
 		if ok {

client/internal/engine.go

@@ -223,7 +223,7 @@ func (e *Engine) Start() error {
 
 	e.routeManager = routemanager.NewManager(e.ctx, e.config.WgPrivateKey.PublicKey().String(), e.wgInterface, e.statusRecorder)
 
-	e.firewallManager, err = buildFirewallManager()
+	e.firewallManager, err = buildFirewallManager(wgIfaceName)
 	if err != nil {
 		log.Errorf("failed to create firewall manager, ACL policy will not work: %s", err.Error())
 	} else {

client/internal/engine_test.go

@@ -6,6 +6,7 @@ import (
 	"net"
 	"net/netip"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"runtime"
 	"strings"
@@ -945,6 +946,12 @@ func TestEngine_firewallManager(t *testing.T) {
 	if runtime.GOOS != "linux" {
 		t.Skipf("firewall manager not supported in the: %s", runtime.GOOS)
 		return
+	} else {
+		_, err := exec.LookPath("iptables")
+		if err != nil {
+			t.Skipf("iptables not found: %v", err)
+			return
+		}
 	}
 
 	ctx, cancel := context.WithTimeout(CtxInitState(context.Background()), 10*time.Second)

client/internal/firewall.go

@@ -1,3 +1,5 @@
+//go:build !linux
+
 package internal
 
 import (
@@ -5,15 +7,8 @@ import (
 	"runtime"
 
 	"github.com/netbirdio/netbird/client/firewall"
-	"github.com/netbirdio/netbird/client/firewall/iptables"
 )
 
-func buildFirewallManager() (fw firewall.Manager, err error) {
+func buildFirewallManager(wgIfaceName string) (fw firewall.Manager, err error) {
-	switch runtime.GOOS {
+	return nil, fmt.Errorf("not implemented for this OS: %s", runtime.GOOS)
-	case "linux":
-		return iptables.Create()
-
-	default:
-		return nil, fmt.Errorf("not implemented for this OS: %s", runtime.GOOS)
-	}
 }

client/internal/firewall_linux.go

@@ -0,0 +1,18 @@
+package internal
+
+import (
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/client/firewall"
+	"github.com/netbirdio/netbird/client/firewall/iptables"
+)
+
+// buildFirewallManager creates a firewall manager instance for the Linux
+func buildFirewallManager(wgIfaceName string) (firewall.Manager, error) {
+	fw, err := iptables.Create(wgIfaceName)
+	if err != nil {
+		log.Debugf("failed to create iptables manager: %s", err)
+		return nil, err
+	}
+	return fw, nil
+}