Feat linux firewall support (#805)

Update the client's engine to apply firewall rules received from the manager (results of ACL policy).

client/firewall/uspfilter/rule.go

@@ -0,0 +1,27 @@
+package uspfilter
+
+import (
+	"net"
+
+	"github.com/google/gopacket"
+
+	fw "github.com/netbirdio/netbird/client/firewall"
+)
+
+// Rule to handle management of rules
+type Rule struct {
+	id         string
+	ip         net.IP
+	ipLayer    gopacket.LayerType
+	protoLayer gopacket.LayerType
+	direction  fw.RuleDirection
+	sPort      uint16
+	dPort      uint16
+	drop       bool
+	comment    string
+}
+
+// GetRuleID returns the rule id
+func (r *Rule) GetRuleID() string {
+	return r.id
+}

client/firewall/uspfilter/uspfilter.go

@@ -0,0 +1,291 @@
+package uspfilter
+
+import (
+	"fmt"
+	"net"
+	"sync"
+
+	"github.com/google/gopacket"
+	"github.com/google/gopacket/layers"
+	"github.com/google/uuid"
+	log "github.com/sirupsen/logrus"
+
+	fw "github.com/netbirdio/netbird/client/firewall"
+	"github.com/netbirdio/netbird/iface"
+)
+
+const layerTypeAll = 0
+
+// IFaceMapper defines subset methods of interface required for manager
+type IFaceMapper interface {
+	SetFiltering(iface.PacketFilter) error
+}
+
+// Manager userspace firewall manager
+type Manager struct {
+	outgoingRules []Rule
+	incomingRules []Rule
+	rulesIndex    map[string]int
+	wgNetwork     *net.IPNet
+	decoders      sync.Pool
+
+	mutex sync.RWMutex
+}
+
+// decoder for packages
+type decoder struct {
+	eth     layers.Ethernet
+	ip4     layers.IPv4
+	ip6     layers.IPv6
+	tcp     layers.TCP
+	udp     layers.UDP
+	icmp4   layers.ICMPv4
+	icmp6   layers.ICMPv6
+	decoded []gopacket.LayerType
+	parser  *gopacket.DecodingLayerParser
+}
+
+// Create userspace firewall manager constructor
+func Create(iface IFaceMapper) (*Manager, error) {
+	m := &Manager{
+		rulesIndex: make(map[string]int),
+		decoders: sync.Pool{
+			New: func() any {
+				d := &decoder{
+					decoded: []gopacket.LayerType{},
+				}
+				d.parser = gopacket.NewDecodingLayerParser(
+					layers.LayerTypeIPv4,
+					&d.eth, &d.ip4, &d.ip6, &d.icmp4, &d.icmp6, &d.tcp, &d.udp,
+				)
+				d.parser.IgnoreUnsupported = true
+				return d
+			},
+		},
+	}
+
+	if err := iface.SetFiltering(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+// AddFiltering rule to the firewall
+//
+// If comment argument is empty firewall manager should set
+// rule ID as comment for the rule
+func (m *Manager) AddFiltering(
+	ip net.IP,
+	proto fw.Protocol,
+	sPort *fw.Port,
+	dPort *fw.Port,
+	direction fw.RuleDirection,
+	action fw.Action,
+	comment string,
+) (fw.Rule, error) {
+	r := Rule{
+		id:        uuid.New().String(),
+		ip:        ip,
+		ipLayer:   layers.LayerTypeIPv6,
+		direction: direction,
+		drop:      action == fw.ActionDrop,
+		comment:   comment,
+	}
+	if ipNormalized := ip.To4(); ipNormalized != nil {
+		r.ipLayer = layers.LayerTypeIPv4
+		r.ip = ipNormalized
+	}
+
+	if sPort != nil && len(sPort.Values) == 1 {
+		r.sPort = uint16(sPort.Values[0])
+	}
+
+	if dPort != nil && len(dPort.Values) == 1 {
+		r.dPort = uint16(dPort.Values[0])
+	}
+
+	switch proto {
+	case fw.ProtocolTCP:
+		r.protoLayer = layers.LayerTypeTCP
+	case fw.ProtocolUDP:
+		r.protoLayer = layers.LayerTypeUDP
+	case fw.ProtocolICMP:
+		r.protoLayer = layers.LayerTypeICMPv4
+		if r.ipLayer == layers.LayerTypeIPv6 {
+			r.protoLayer = layers.LayerTypeICMPv6
+		}
+	case fw.ProtocolALL:
+		r.protoLayer = layerTypeAll
+	}
+
+	m.mutex.Lock()
+	var p int
+	if direction == fw.RuleDirectionIN {
+		m.incomingRules = append(m.incomingRules, r)
+		p = len(m.incomingRules) - 1
+	} else {
+		m.outgoingRules = append(m.outgoingRules, r)
+		p = len(m.outgoingRules) - 1
+	}
+	m.rulesIndex[r.id] = p
+	m.mutex.Unlock()
+
+	return &r, nil
+}
+
+// DeleteRule from the firewall by rule definition
+func (m *Manager) DeleteRule(rule fw.Rule) error {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	r, ok := rule.(*Rule)
+	if !ok {
+		return fmt.Errorf("delete rule: invalid rule type: %T", rule)
+	}
+
+	p, ok := m.rulesIndex[r.id]
+	if !ok {
+		return fmt.Errorf("delete rule: no rule with such id: %v", r.id)
+	}
+	delete(m.rulesIndex, r.id)
+
+	var toUpdate []Rule
+	if r.direction == fw.RuleDirectionIN {
+		m.incomingRules = append(m.incomingRules[:p], m.incomingRules[p+1:]...)
+		toUpdate = m.incomingRules
+	} else {
+		m.outgoingRules = append(m.outgoingRules[:p], m.outgoingRules[p+1:]...)
+		toUpdate = m.outgoingRules
+	}
+
+	for i := 0; i < len(toUpdate); i++ {
+		m.rulesIndex[toUpdate[i].id] = i
+	}
+	return nil
+}
+
+// Reset firewall to the default state
+func (m *Manager) Reset() error {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	m.outgoingRules = m.outgoingRules[:0]
+	m.incomingRules = m.incomingRules[:0]
+	m.rulesIndex = make(map[string]int)
+
+	return nil
+}
+
+// DropOutgoing filter outgoing packets
+func (m *Manager) DropOutgoing(packetData []byte) bool {
+	return m.dropFilter(packetData, m.outgoingRules, false)
+}
+
+// DropIncoming filter incoming packets
+func (m *Manager) DropIncoming(packetData []byte) bool {
+	return m.dropFilter(packetData, m.incomingRules, true)
+}
+
+// dropFilter imlements same logic for booth direction of the traffic
+func (m *Manager) dropFilter(packetData []byte, rules []Rule, isIncomingPacket bool) bool {
+	m.mutex.RLock()
+	defer m.mutex.RUnlock()
+
+	d := m.decoders.Get().(*decoder)
+	defer m.decoders.Put(d)
+
+	if err := d.parser.DecodeLayers(packetData, &d.decoded); err != nil {
+		log.Tracef("couldn't decode layer, err: %s", err)
+		return true
+	}
+
+	if len(d.decoded) < 2 {
+		log.Tracef("not enough levels in network packet")
+		return true
+	}
+
+	ipLayer := d.decoded[0]
+
+	switch ipLayer {
+	case layers.LayerTypeIPv4:
+		if !m.wgNetwork.Contains(d.ip4.SrcIP) || !m.wgNetwork.Contains(d.ip4.DstIP) {
+			return false
+		}
+	case layers.LayerTypeIPv6:
+		if !m.wgNetwork.Contains(d.ip6.SrcIP) || !m.wgNetwork.Contains(d.ip6.DstIP) {
+			return false
+		}
+	default:
+		log.Errorf("unknown layer: %v", d.decoded[0])
+		return true
+	}
+	payloadLayer := d.decoded[1]
+
+	// check if IP address match by IP
+	for _, rule := range rules {
+		switch ipLayer {
+		case layers.LayerTypeIPv4:
+			if isIncomingPacket {
+				if !d.ip4.SrcIP.Equal(rule.ip) {
+					continue
+				}
+			} else {
+				if !d.ip4.DstIP.Equal(rule.ip) {
+					continue
+				}
+			}
+		case layers.LayerTypeIPv6:
+			if isIncomingPacket {
+				if !d.ip6.SrcIP.Equal(rule.ip) {
+					continue
+				}
+			} else {
+				if !d.ip6.DstIP.Equal(rule.ip) {
+					continue
+				}
+			}
+		}
+
+		if rule.protoLayer == layerTypeAll {
+			return rule.drop
+		}
+
+		if payloadLayer != rule.protoLayer {
+			continue
+		}
+
+		switch payloadLayer {
+		case layers.LayerTypeTCP:
+			if rule.sPort == 0 && rule.dPort == 0 {
+				return rule.drop
+			}
+			if rule.sPort != 0 && rule.sPort == uint16(d.tcp.SrcPort) {
+				return rule.drop
+			}
+			if rule.dPort != 0 && rule.dPort == uint16(d.tcp.DstPort) {
+				return rule.drop
+			}
+		case layers.LayerTypeUDP:
+			if rule.sPort == 0 && rule.dPort == 0 {
+				return rule.drop
+			}
+			if rule.sPort != 0 && rule.sPort == uint16(d.udp.SrcPort) {
+				return rule.drop
+			}
+			if rule.dPort != 0 && rule.dPort == uint16(d.udp.DstPort) {
+				return rule.drop
+			}
+			return rule.drop
+		case layers.LayerTypeICMPv4, layers.LayerTypeICMPv6:
+			return rule.drop
+		}
+	}
+
+	// default policy is DROP ALL
+	return true
+}
+
+// SetNetwork of the wireguard interface to which filtering applied
+func (m *Manager) SetNetwork(network *net.IPNet) {
+	m.wgNetwork = network
+}

client/firewall/uspfilter/uspfilter_test.go

@@ -0,0 +1,207 @@
+package uspfilter
+
+import (
+	"fmt"
+	"net"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+
+	fw "github.com/netbirdio/netbird/client/firewall"
+	"github.com/netbirdio/netbird/iface"
+)
+
+type IFaceMock struct {
+	SetFilteringFunc func(iface.PacketFilter) error
+}
+
+func (i *IFaceMock) SetFiltering(iface iface.PacketFilter) error {
+	if i.SetFilteringFunc == nil {
+		return fmt.Errorf("not implemented")
+	}
+	return i.SetFilteringFunc(iface)
+}
+
+func TestManagerCreate(t *testing.T) {
+	ifaceMock := &IFaceMock{
+		SetFilteringFunc: func(iface.PacketFilter) error { return nil },
+	}
+
+	m, err := Create(ifaceMock)
+	if err != nil {
+		t.Errorf("failed to create Manager: %v", err)
+		return
+	}
+
+	if m == nil {
+		t.Error("Manager is nil")
+	}
+}
+
+func TestManagerAddFiltering(t *testing.T) {
+	isSetFilteringCalled := false
+	ifaceMock := &IFaceMock{
+		SetFilteringFunc: func(iface.PacketFilter) error {
+			isSetFilteringCalled = true
+			return nil
+		},
+	}
+
+	m, err := Create(ifaceMock)
+	if err != nil {
+		t.Errorf("failed to create Manager: %v", err)
+		return
+	}
+
+	ip := net.ParseIP("192.168.1.1")
+	proto := fw.ProtocolTCP
+	port := &fw.Port{Values: []int{80}}
+	direction := fw.RuleDirectionOUT
+	action := fw.ActionDrop
+	comment := "Test rule"
+
+	rule, err := m.AddFiltering(ip, proto, nil, port, direction, action, comment)
+	if err != nil {
+		t.Errorf("failed to add filtering: %v", err)
+		return
+	}
+
+	if rule == nil {
+		t.Error("Rule is nil")
+		return
+	}
+
+	if !isSetFilteringCalled {
+		t.Error("SetFiltering was not called")
+		return
+	}
+}
+
+func TestManagerDeleteRule(t *testing.T) {
+	ifaceMock := &IFaceMock{
+		SetFilteringFunc: func(iface.PacketFilter) error { return nil },
+	}
+
+	m, err := Create(ifaceMock)
+	if err != nil {
+		t.Errorf("failed to create Manager: %v", err)
+		return
+	}
+
+	ip := net.ParseIP("192.168.1.1")
+	proto := fw.ProtocolTCP
+	port := &fw.Port{Values: []int{80}}
+	direction := fw.RuleDirectionOUT
+	action := fw.ActionDrop
+	comment := "Test rule"
+
+	rule, err := m.AddFiltering(ip, proto, nil, port, direction, action, comment)
+	if err != nil {
+		t.Errorf("failed to add filtering: %v", err)
+		return
+	}
+
+	ip = net.ParseIP("192.168.1.1")
+	proto = fw.ProtocolTCP
+	port = &fw.Port{Values: []int{80}}
+	direction = fw.RuleDirectionIN
+	action = fw.ActionDrop
+	comment = "Test rule 2"
+
+	rule2, err := m.AddFiltering(ip, proto, nil, port, direction, action, comment)
+	if err != nil {
+		t.Errorf("failed to add filtering: %v", err)
+		return
+	}
+
+	err = m.DeleteRule(rule)
+	if err != nil {
+		t.Errorf("failed to delete rule: %v", err)
+		return
+	}
+
+	if idx, ok := m.rulesIndex[rule2.GetRuleID()]; !ok || len(m.incomingRules) != 1 || idx != 0 {
+		t.Errorf("rule2 is not in the rulesIndex")
+	}
+
+	err = m.DeleteRule(rule2)
+	if err != nil {
+		t.Errorf("failed to delete rule: %v", err)
+		return
+	}
+
+	if len(m.rulesIndex) != 0 || len(m.incomingRules) != 0 {
+		t.Errorf("rule1 still in the rulesIndex")
+	}
+}
+
+func TestManagerReset(t *testing.T) {
+	ifaceMock := &IFaceMock{
+		SetFilteringFunc: func(iface.PacketFilter) error { return nil },
+	}
+
+	m, err := Create(ifaceMock)
+	if err != nil {
+		t.Errorf("failed to create Manager: %v", err)
+		return
+	}
+
+	ip := net.ParseIP("192.168.1.1")
+	proto := fw.ProtocolTCP
+	port := &fw.Port{Values: []int{80}}
+	direction := fw.RuleDirectionOUT
+	action := fw.ActionDrop
+	comment := "Test rule"
+
+	_, err = m.AddFiltering(ip, proto, nil, port, direction, action, comment)
+	if err != nil {
+		t.Errorf("failed to add filtering: %v", err)
+		return
+	}
+
+	err = m.Reset()
+	if err != nil {
+		t.Errorf("failed to reset Manager: %v", err)
+		return
+	}
+
+	if len(m.rulesIndex) != 0 || len(m.outgoingRules) != 0 || len(m.incomingRules) != 0 {
+		t.Errorf("rules is not empty")
+	}
+}
+
+func TestUSPFilterCreatePerformance(t *testing.T) {
+	for _, testMax := range []int{10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000} {
+		t.Run(fmt.Sprintf("Testing %d rules", testMax), func(t *testing.T) {
+			// just check on the local interface
+			ifaceMock := &IFaceMock{
+				SetFilteringFunc: func(iface.PacketFilter) error { return nil },
+			}
+			manager, err := Create(ifaceMock)
+			require.NoError(t, err)
+			time.Sleep(time.Second)
+
+			defer func() {
+				if err := manager.Reset(); err != nil {
+					t.Errorf("clear the manager state: %v", err)
+				}
+				time.Sleep(time.Second)
+			}()
+
+			ip := net.ParseIP("10.20.0.100")
+			start := time.Now()
+			for i := 0; i < testMax; i++ {
+				port := &fw.Port{Values: []int{1000 + i}}
+				if i%2 == 0 {
+					_, err = manager.AddFiltering(ip, "tcp", nil, port, fw.RuleDirectionOUT, fw.ActionAccept, "accept HTTP traffic")
+				} else {
+					_, err = manager.AddFiltering(ip, "tcp", nil, port, fw.RuleDirectionIN, fw.ActionAccept, "accept HTTP traffic")
+				}
+
+				require.NoError(t, err, "failed to add rule")
+			}
+			t.Logf("execution avg per rule: %s", time.Since(start)/time.Duration(testMax))
+		})
+	}
+}