Fix/acl for forward (#1305)

Fix ACL on routed traffic and code refactor

client/firewall/nftables/manager_linux.go

@@ -2,90 +2,52 @@ package nftables
 
 import (
 	"bytes"
-	"encoding/binary"
+	"context"
 	"fmt"
 	"net"
-	"net/netip"
-	"strconv"
-	"strings"
 	"sync"
-	"time"
 
 	"github.com/google/nftables"
 	"github.com/google/nftables/expr"
 	log "github.com/sirupsen/logrus"
-	"golang.org/x/sys/unix"
 
-	fw "github.com/netbirdio/netbird/client/firewall"
-	"github.com/netbirdio/netbird/iface"
+	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 )
 
 const (
-	// FilterTableName is the name of the table that is used for filtering by the Netbird client
-	FilterTableName = "netbird-acl"
-
-	// FilterInputChainName is the name of the chain that is used for filtering incoming packets
-	FilterInputChainName = "netbird-acl-input-filter"
-
-	// FilterOutputChainName is the name of the chain that is used for filtering outgoing packets
-	FilterOutputChainName = "netbird-acl-output-filter"
-
-	AllowNetbirdInputRuleID = "allow Netbird incoming traffic"
+	// tableName is the name of the table that is used for filtering by the Netbird client
+	tableName = "netbird"
 )
 
-var anyIP = []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
-
 // Manager of iptables firewall
 type Manager struct {
-	mutex sync.Mutex
-
-	rConn     *nftables.Conn
-	sConn     *nftables.Conn
-	tableIPv4 *nftables.Table
-	tableIPv6 *nftables.Table
-
-	filterInputChainIPv4  *nftables.Chain
-	filterOutputChainIPv4 *nftables.Chain
-
-	filterInputChainIPv6  *nftables.Chain
-	filterOutputChainIPv6 *nftables.Chain
-
-	rulesetManager *rulesetManager
-	setRemovedIPs  map[string]struct{}
-	setRemoved     map[string]*nftables.Set
-
+	mutex   sync.Mutex
+	rConn   *nftables.Conn
 	wgIface iFaceMapper
-}
 
-// iFaceMapper defines subset methods of interface required for manager
-type iFaceMapper interface {
-	Name() string
-	Address() iface.WGAddress
+	router     *router
+	aclManager *AclManager
 }
 
 // Create nftables firewall manager
-func Create(wgIface iFaceMapper) (*Manager, error) {
-	// sConn is used for creating sets and adding/removing elements from them
-	// it's differ then rConn (which does create new conn for each flush operation)
-	// and is permanent. Using same connection for booth type of operations
-	// overloads netlink with high amount of rules ( > 10000)
-	sConn, err := nftables.New(nftables.AsLasting())
+func Create(context context.Context, wgIface iFaceMapper) (*Manager, error) {
+	m := &Manager{
+		rConn:   &nftables.Conn{},
+		wgIface: wgIface,
+	}
+
+	workTable, err := m.createWorkTable()
 	if err != nil {
 		return nil, err
 	}
 
-	m := &Manager{
-		rConn: &nftables.Conn{},
-		sConn: sConn,
-
-		rulesetManager: newRuleManager(),
-		setRemovedIPs:  map[string]struct{}{},
-		setRemoved:     map[string]*nftables.Set{},
-
-		wgIface: wgIface,
+	m.router, err = newRouter(context, workTable)
+	if err != nil {
+		return nil, err
 	}
 
-	if err := m.Reset(); err != nil {
+	m.aclManager, err = newAclManager(workTable, wgIface, m.router.RouteingFwChainName())
+	if err != nil {
 		return nil, err
 	}
 
@@ -98,649 +60,58 @@ func Create(wgIface iFaceMapper) (*Manager, error) {
 // 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,
+	proto firewall.Protocol,
+	sPort *firewall.Port,
+	dPort *firewall.Port,
+	direction firewall.RuleDirection,
+	action firewall.Action,
 	ipsetName string,
 	comment string,
-) (fw.Rule, error) {
+) ([]firewall.Rule, error) {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	var (
-		err   error
-		ipset *nftables.Set
-		table *nftables.Table
-		chain *nftables.Chain
-	)
-
-	if direction == fw.RuleDirectionOUT {
-		table, chain, err = m.chain(
-			ip,
-			FilterOutputChainName,
-			nftables.ChainHookOutput,
-			nftables.ChainPriorityFilter,
-			nftables.ChainTypeFilter)
-	} else {
-		table, chain, err = m.chain(
-			ip,
-			FilterInputChainName,
-			nftables.ChainHookInput,
-			nftables.ChainPriorityFilter,
-			nftables.ChainTypeFilter)
-	}
-	if err != nil {
-		return nil, err
-	}
-
 	rawIP := ip.To4()
 	if rawIP == nil {
-		rawIP = ip.To16()
+		return nil, fmt.Errorf("unsupported IP version: %s", ip.String())
 	}
 
-	rulesetID := m.getRulesetID(ip, proto, sPort, dPort, direction, action, ipsetName)
-
-	if ipsetName != "" {
-		// if we already have set with given name, just add ip to the set
-		// and return rule with new ID in other case let's create rule
-		// with fresh created set and set element
-
-		var isSetNew bool
-		ipset, err = m.rConn.GetSetByName(table, ipsetName)
-		if err != nil {
-			if ipset, err = m.createSet(table, rawIP, ipsetName); err != nil {
-				return nil, fmt.Errorf("get set name: %v", err)
-			}
-			isSetNew = true
-		}
-
-		if err := m.sConn.SetAddElements(ipset, []nftables.SetElement{{Key: rawIP}}); err != nil {
-			return nil, fmt.Errorf("add set element for the first time: %v", err)
-		}
-		if err := m.sConn.Flush(); err != nil {
-			return nil, fmt.Errorf("flush add elements: %v", err)
-		}
-
-		if !isSetNew {
-			// if we already have nftables rules with set for given direction
-			// just add new rule to the ruleset and return new fw.Rule object
-
-			if ruleset, ok := m.rulesetManager.getRuleset(rulesetID); ok {
-				return m.rulesetManager.addRule(ruleset, rawIP)
-			}
-			// if ipset exists but it is not linked to rule for given direction
-			// create new rule for direction and bind ipset to it later
-		}
-	}
-
-	ifaceKey := expr.MetaKeyIIFNAME
-	if direction == fw.RuleDirectionOUT {
-		ifaceKey = expr.MetaKeyOIFNAME
-	}
-	expressions := []expr.Any{
-		&expr.Meta{Key: ifaceKey, Register: 1},
-		&expr.Cmp{
-			Op:       expr.CmpOpEq,
-			Register: 1,
-			Data:     ifname(m.wgIface.Name()),
-		},
-	}
-
-	if proto != "all" {
-		expressions = append(expressions, &expr.Payload{
-			DestRegister: 1,
-			Base:         expr.PayloadBaseNetworkHeader,
-			Offset:       uint32(9),
-			Len:          uint32(1),
-		})
-
-		var protoData []byte
-		switch proto {
-		case fw.ProtocolTCP:
-			protoData = []byte{unix.IPPROTO_TCP}
-		case fw.ProtocolUDP:
-			protoData = []byte{unix.IPPROTO_UDP}
-		case fw.ProtocolICMP:
-			protoData = []byte{unix.IPPROTO_ICMP}
-		default:
-			return nil, fmt.Errorf("unsupported protocol: %s", proto)
-		}
-		expressions = append(expressions, &expr.Cmp{
-			Register: 1,
-			Op:       expr.CmpOpEq,
-			Data:     protoData,
-		})
-	}
-
-	// check if rawIP contains zeroed IPv4 0.0.0.0 or same IPv6 value
-	// in that case not add IP match expression into the rule definition
-	if !bytes.HasPrefix(anyIP, rawIP) {
-		// source address position
-		addrLen := uint32(len(rawIP))
-		addrOffset := uint32(12)
-		if addrLen == 16 {
-			addrOffset = 8
-		}
-
-		// change to destination address position if need
-		if direction == fw.RuleDirectionOUT {
-			addrOffset += addrLen
-		}
-
-		expressions = append(expressions,
-			&expr.Payload{
-				DestRegister: 1,
-				Base:         expr.PayloadBaseNetworkHeader,
-				Offset:       addrOffset,
-				Len:          addrLen,
-			},
-		)
-		// add individual IP for match if no ipset defined
-		if ipset == nil {
-			expressions = append(expressions,
-				&expr.Cmp{
-					Op:       expr.CmpOpEq,
-					Register: 1,
-					Data:     rawIP,
-				},
-			)
-		} else {
-			expressions = append(expressions,
-				&expr.Lookup{
-					SourceRegister: 1,
-					SetName:        ipsetName,
-					SetID:          ipset.ID,
-				},
-			)
-		}
-	}
-
-	if sPort != nil && len(sPort.Values) != 0 {
-		expressions = append(expressions,
-			&expr.Payload{
-				DestRegister: 1,
-				Base:         expr.PayloadBaseTransportHeader,
-				Offset:       0,
-				Len:          2,
-			},
-			&expr.Cmp{
-				Op:       expr.CmpOpEq,
-				Register: 1,
-				Data:     encodePort(*sPort),
-			},
-		)
-	}
-
-	if dPort != nil && len(dPort.Values) != 0 {
-		expressions = append(expressions,
-			&expr.Payload{
-				DestRegister: 1,
-				Base:         expr.PayloadBaseTransportHeader,
-				Offset:       2,
-				Len:          2,
-			},
-			&expr.Cmp{
-				Op:       expr.CmpOpEq,
-				Register: 1,
-				Data:     encodePort(*dPort),
-			},
-		)
-	}
-
-	if action == fw.ActionAccept {
-		expressions = append(expressions, &expr.Verdict{Kind: expr.VerdictAccept})
-	} else {
-		expressions = append(expressions, &expr.Verdict{Kind: expr.VerdictDrop})
-	}
-
-	userData := []byte(strings.Join([]string{rulesetID, comment}, " "))
-
-	rule := m.rConn.InsertRule(&nftables.Rule{
-		Table:    table,
-		Chain:    chain,
-		Position: 0,
-		Exprs:    expressions,
-		UserData: userData,
-	})
-	if err := m.rConn.Flush(); err != nil {
-		return nil, fmt.Errorf("flush insert rule: %v", err)
-	}
-
-	ruleset := m.rulesetManager.createRuleset(rulesetID, rule, ipset)
-	return m.rulesetManager.addRule(ruleset, rawIP)
-}
-
-// getRulesetID returns ruleset ID based on given parameters
-func (m *Manager) getRulesetID(
-	ip net.IP,
-	proto fw.Protocol,
-	sPort *fw.Port,
-	dPort *fw.Port,
-	direction fw.RuleDirection,
-	action fw.Action,
-	ipsetName string,
-) string {
-	rulesetID := ":" + strconv.Itoa(int(direction)) + ":"
-	if sPort != nil {
-		rulesetID += sPort.String()
-	}
-	rulesetID += ":"
-	if dPort != nil {
-		rulesetID += dPort.String()
-	}
-	rulesetID += ":"
-	rulesetID += strconv.Itoa(int(action))
-	if ipsetName == "" {
-		return "ip:" + ip.String() + rulesetID
-	}
-	return "set:" + ipsetName + rulesetID
-}
-
-// createSet in given table by name
-func (m *Manager) createSet(
-	table *nftables.Table,
-	rawIP []byte,
-	name string,
-) (*nftables.Set, error) {
-	keyType := nftables.TypeIPAddr
-	if len(rawIP) == 16 {
-		keyType = nftables.TypeIP6Addr
-	}
-	// else we create new ipset and continue creating rule
-	ipset := &nftables.Set{
-		Name:    name,
-		Table:   table,
-		Dynamic: true,
-		KeyType: keyType,
-	}
-
-	if err := m.rConn.AddSet(ipset, nil); err != nil {
-		return nil, fmt.Errorf("create set: %v", err)
-	}
-
-	if err := m.rConn.Flush(); err != nil {
-		return nil, fmt.Errorf("flush created set: %v", err)
-	}
-
-	return ipset, nil
-}
-
-// chain returns the chain for the given IP address with specific settings
-func (m *Manager) chain(
-	ip net.IP,
-	name string,
-	hook nftables.ChainHook,
-	priority nftables.ChainPriority,
-	cType nftables.ChainType,
-) (*nftables.Table, *nftables.Chain, error) {
-	var err error
-
-	getChain := func(c *nftables.Chain, tf nftables.TableFamily) (*nftables.Chain, error) {
-		if c != nil {
-			return c, nil
-		}
-		return m.createChainIfNotExists(tf, FilterTableName, name, hook, priority, cType)
-	}
-
-	if ip.To4() != nil {
-		if name == FilterInputChainName {
-			m.filterInputChainIPv4, err = getChain(m.filterInputChainIPv4, nftables.TableFamilyIPv4)
-			return m.tableIPv4, m.filterInputChainIPv4, err
-		}
-		m.filterOutputChainIPv4, err = getChain(m.filterOutputChainIPv4, nftables.TableFamilyIPv4)
-		return m.tableIPv4, m.filterOutputChainIPv4, err
-	}
-	if name == FilterInputChainName {
-		m.filterInputChainIPv6, err = getChain(m.filterInputChainIPv6, nftables.TableFamilyIPv6)
-		return m.tableIPv4, m.filterInputChainIPv6, err
-	}
-	m.filterOutputChainIPv6, err = getChain(m.filterOutputChainIPv6, nftables.TableFamilyIPv6)
-	return m.tableIPv4, m.filterOutputChainIPv6, err
-}
-
-// table returns the table for the given family of the IP address
-func (m *Manager) table(
-	family nftables.TableFamily, tableName string,
-) (*nftables.Table, error) {
-	// we cache access to Netbird ACL table only
-	if tableName != FilterTableName {
-		return m.createTableIfNotExists(nftables.TableFamilyIPv4, tableName)
-	}
-
-	if family == nftables.TableFamilyIPv4 {
-		if m.tableIPv4 != nil {
-			return m.tableIPv4, nil
-		}
-
-		table, err := m.createTableIfNotExists(nftables.TableFamilyIPv4, tableName)
-		if err != nil {
-			return nil, err
-		}
-		m.tableIPv4 = table
-		return m.tableIPv4, nil
-	}
-
-	if m.tableIPv6 != nil {
-		return m.tableIPv6, nil
-	}
-
-	table, err := m.createTableIfNotExists(nftables.TableFamilyIPv6, tableName)
-	if err != nil {
-		return nil, err
-	}
-	m.tableIPv6 = table
-	return m.tableIPv6, nil
-}
-
-func (m *Manager) createTableIfNotExists(
-	family nftables.TableFamily, tableName string,
-) (*nftables.Table, error) {
-	tables, err := m.rConn.ListTablesOfFamily(family)
-	if err != nil {
-		return nil, fmt.Errorf("list of tables: %w", err)
-	}
-
-	for _, t := range tables {
-		if t.Name == tableName {
-			return t, nil
-		}
-	}
-
-	table := m.rConn.AddTable(&nftables.Table{Name: tableName, Family: nftables.TableFamilyIPv4})
-	if err := m.rConn.Flush(); err != nil {
-		return nil, err
-	}
-	return table, nil
-}
-
-func (m *Manager) createChainIfNotExists(
-	family nftables.TableFamily,
-	tableName string,
-	name string,
-	hooknum nftables.ChainHook,
-	priority nftables.ChainPriority,
-	chainType nftables.ChainType,
-) (*nftables.Chain, error) {
-	table, err := m.table(family, tableName)
-	if err != nil {
-		return nil, err
-	}
-
-	chains, err := m.rConn.ListChainsOfTableFamily(family)
-	if err != nil {
-		return nil, fmt.Errorf("list of chains: %w", err)
-	}
-
-	for _, c := range chains {
-		if c.Name == name && c.Table.Name == table.Name {
-			return c, nil
-		}
-	}
-
-	polAccept := nftables.ChainPolicyAccept
-	chain := &nftables.Chain{
-		Name:     name,
-		Table:    table,
-		Hooknum:  hooknum,
-		Priority: priority,
-		Type:     chainType,
-		Policy:   &polAccept,
-	}
-
-	chain = m.rConn.AddChain(chain)
-
-	ifaceKey := expr.MetaKeyIIFNAME
-	shiftDSTAddr := 0
-	if name == FilterOutputChainName {
-		ifaceKey = expr.MetaKeyOIFNAME
-		shiftDSTAddr = 1
-	}
-
-	expressions := []expr.Any{
-		&expr.Meta{Key: ifaceKey, Register: 1},
-		&expr.Cmp{
-			Op:       expr.CmpOpEq,
-			Register: 1,
-			Data:     ifname(m.wgIface.Name()),
-		},
-	}
-
-	mask, _ := netip.AddrFromSlice(m.wgIface.Address().Network.Mask)
-	if m.wgIface.Address().IP.To4() == nil {
-		ip, _ := netip.AddrFromSlice(m.wgIface.Address().Network.IP.To16())
-		expressions = append(expressions,
-			&expr.Payload{
-				DestRegister: 2,
-				Base:         expr.PayloadBaseNetworkHeader,
-				Offset:       uint32(8 + (16 * shiftDSTAddr)),
-				Len:          16,
-			},
-			&expr.Bitwise{
-				SourceRegister: 2,
-				DestRegister:   2,
-				Len:            16,
-				Xor:            []byte{0x0, 0x0, 0x0, 0x0},
-				Mask:           mask.Unmap().AsSlice(),
-			},
-			&expr.Cmp{
-				Op:       expr.CmpOpNeq,
-				Register: 2,
-				Data:     ip.Unmap().AsSlice(),
-			},
-			&expr.Verdict{Kind: expr.VerdictAccept},
-		)
-	} else {
-		ip, _ := netip.AddrFromSlice(m.wgIface.Address().Network.IP.To4())
-		expressions = append(expressions,
-			&expr.Payload{
-				DestRegister: 2,
-				Base:         expr.PayloadBaseNetworkHeader,
-				Offset:       uint32(12 + (4 * shiftDSTAddr)),
-				Len:          4,
-			},
-			&expr.Bitwise{
-				SourceRegister: 2,
-				DestRegister:   2,
-				Len:            4,
-				Xor:            []byte{0x0, 0x0, 0x0, 0x0},
-				Mask:           m.wgIface.Address().Network.Mask,
-			},
-			&expr.Cmp{
-				Op:       expr.CmpOpNeq,
-				Register: 2,
-				Data:     ip.Unmap().AsSlice(),
-			},
-			&expr.Verdict{Kind: expr.VerdictAccept},
-		)
-	}
-
-	_ = m.rConn.AddRule(&nftables.Rule{
-		Table: table,
-		Chain: chain,
-		Exprs: expressions,
-	})
-
-	expressions = []expr.Any{
-		&expr.Meta{Key: ifaceKey, Register: 1},
-		&expr.Cmp{
-			Op:       expr.CmpOpEq,
-			Register: 1,
-			Data:     ifname(m.wgIface.Name()),
-		},
-		&expr.Verdict{Kind: expr.VerdictDrop},
-	}
-	_ = m.rConn.AddRule(&nftables.Rule{
-		Table: table,
-		Chain: chain,
-		Exprs: expressions,
-	})
-
-	if err := m.rConn.Flush(); err != nil {
-		return nil, err
-	}
-
-	return chain, nil
+	return m.aclManager.AddFiltering(ip, proto, sPort, dPort, direction, action, ipsetName, comment)
 }
 
 // DeleteRule from the firewall by rule definition
-func (m *Manager) DeleteRule(rule fw.Rule) error {
+func (m *Manager) DeleteRule(rule firewall.Rule) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	nativeRule, ok := rule.(*Rule)
-	if !ok {
-		return fmt.Errorf("invalid rule type")
-	}
-
-	if nativeRule.nftRule == nil {
-		return nil
-	}
-
-	if nativeRule.nftSet != nil {
-		// call twice of delete set element raises error
-		// so we need to check if element is already removed
-		key := fmt.Sprintf("%s:%v", nativeRule.nftSet.Name, nativeRule.ip)
-		if _, ok := m.setRemovedIPs[key]; !ok {
-			err := m.sConn.SetDeleteElements(nativeRule.nftSet, []nftables.SetElement{{Key: nativeRule.ip}})
-			if err != nil {
-				log.Errorf("delete elements for set %q: %v", nativeRule.nftSet.Name, err)
-			}
-			if err := m.sConn.Flush(); err != nil {
-				return err
-			}
-			m.setRemovedIPs[key] = struct{}{}
-		}
-	}
-
-	if m.rulesetManager.deleteRule(nativeRule) {
-		// deleteRule indicates that we still have IP in the ruleset
-		// it means we should not remove the nftables rule but need to update set
-		// so we prepare IP to be removed from set on the next flush call
-		return nil
-	}
-
-	// ruleset doesn't contain IP anymore (or contains only one), remove nft rule
-	if err := m.rConn.DelRule(nativeRule.nftRule); err != nil {
-		log.Errorf("failed to delete rule: %v", err)
-	}
-	if err := m.rConn.Flush(); err != nil {
-		return err
-	}
-	nativeRule.nftRule = nil
-
-	if nativeRule.nftSet != nil {
-		if _, ok := m.setRemoved[nativeRule.nftSet.Name]; !ok {
-			m.setRemoved[nativeRule.nftSet.Name] = nativeRule.nftSet
-		}
-		nativeRule.nftSet = nil
-	}
-
-	return nil
+	return m.aclManager.DeleteRule(rule)
 }
 
-// Reset firewall to the default state
-func (m *Manager) Reset() error {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-
-	chains, err := m.rConn.ListChains()
-	if err != nil {
-		return fmt.Errorf("list of chains: %w", err)
-	}
-	for _, c := range chains {
-		// delete Netbird allow input traffic rule if it exists
-		if c.Table.Name == "filter" && c.Name == "INPUT" {
-			rules, err := m.rConn.GetRules(c.Table, c)
-			if err != nil {
-				log.Errorf("get rules for chain %q: %v", c.Name, err)
-				continue
-			}
-			for _, r := range rules {
-				if bytes.Equal(r.UserData, []byte(AllowNetbirdInputRuleID)) {
-					if err := m.rConn.DelRule(r); err != nil {
-						log.Errorf("delete rule: %v", err)
-					}
-				}
-			}
-		}
-
-		if c.Name == FilterInputChainName || c.Name == FilterOutputChainName {
-			m.rConn.DelChain(c)
-		}
-	}
-
-	tables, err := m.rConn.ListTables()
-	if err != nil {
-		return fmt.Errorf("list of tables: %w", err)
-	}
-	for _, t := range tables {
-		if t.Name == FilterTableName {
-			m.rConn.DelTable(t)
-		}
-	}
-
-	return m.rConn.Flush()
+func (m *Manager) IsServerRouteSupported() bool {
+	return true
 }
 
-// Flush rule/chain/set operations from the buffer
-//
-// Method also get all rules after flush and refreshes handle values in the rulesets
-func (m *Manager) Flush() error {
+func (m *Manager) InsertRoutingRules(pair firewall.RouterPair) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	if err := m.flushWithBackoff(); err != nil {
-		return err
-	}
+	return m.router.InsertRoutingRules(pair)
+}
 
-	// set must be removed after flush rule changes
-	// otherwise we will get error
-	for _, s := range m.setRemoved {
-		m.rConn.FlushSet(s)
-		m.rConn.DelSet(s)
-	}
+func (m *Manager) RemoveRoutingRules(pair firewall.RouterPair) error {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
 
-	if len(m.setRemoved) > 0 {
-		if err := m.flushWithBackoff(); err != nil {
-			return err
-		}
-	}
-
-	m.setRemovedIPs = map[string]struct{}{}
-	m.setRemoved = map[string]*nftables.Set{}
-
-	if err := m.refreshRuleHandles(m.tableIPv4, m.filterInputChainIPv4); err != nil {
-		log.Errorf("failed to refresh rule handles ipv4 input chain: %v", err)
-	}
-
-	if err := m.refreshRuleHandles(m.tableIPv4, m.filterOutputChainIPv4); err != nil {
-		log.Errorf("failed to refresh rule handles IPv4 output chain: %v", err)
-	}
-
-	if err := m.refreshRuleHandles(m.tableIPv6, m.filterInputChainIPv6); err != nil {
-		log.Errorf("failed to refresh rule handles IPv6 input chain: %v", err)
-	}
-
-	if err := m.refreshRuleHandles(m.tableIPv6, m.filterOutputChainIPv6); err != nil {
-		log.Errorf("failed to refresh rule handles IPv6 output chain: %v", err)
-	}
-
-	return nil
+	return m.router.RemoveRoutingRules(pair)
 }
 
 // AllowNetbird allows netbird interface traffic
+// todo review this method usage
 func (m *Manager) AllowNetbird() error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	tf := nftables.TableFamilyIPv4
-	if m.wgIface.Address().IP.To4() == nil {
-		tf = nftables.TableFamilyIPv6
-	}
-
-	chains, err := m.rConn.ListChainsOfTableFamily(tf)
+	chains, err := m.rConn.ListChainsOfTableFamily(nftables.TableFamilyIPv4)
 	if err != nil {
 		return fmt.Errorf("list of chains: %w", err)
 	}
@@ -777,47 +148,75 @@ func (m *Manager) AllowNetbird() error {
 	return nil
 }
 
-func (m *Manager) flushWithBackoff() (err error) {
-	backoff := 4
-	backoffTime := 1000 * time.Millisecond
-	for i := 0; ; i++ {
-		err = m.rConn.Flush()
-		if err != nil {
-			if !strings.Contains(err.Error(), "busy") {
-				return
-			}
-			log.Error("failed to flush nftables, retrying...")
-			if i == backoff-1 {
-				return err
-			}
-			time.Sleep(backoffTime)
-			backoffTime *= 2
-			continue
-		}
-		break
+// Reset firewall to the default state
+func (m *Manager) Reset() error {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	chains, err := m.rConn.ListChains()
+	if err != nil {
+		return fmt.Errorf("list of chains: %w", err)
 	}
-	return
+
+	for _, c := range chains {
+		// delete Netbird allow input traffic rule if it exists
+		if c.Table.Name == "filter" && c.Name == "INPUT" {
+			rules, err := m.rConn.GetRules(c.Table, c)
+			if err != nil {
+				log.Errorf("get rules for chain %q: %v", c.Name, err)
+				continue
+			}
+			for _, r := range rules {
+				if bytes.Equal(r.UserData, []byte(allowNetbirdInputRuleID)) {
+					if err := m.rConn.DelRule(r); err != nil {
+						log.Errorf("delete rule: %v", err)
+					}
+				}
+			}
+		}
+	}
+
+	m.router.ResetForwardRules()
+
+	tables, err := m.rConn.ListTables()
+	if err != nil {
+		return fmt.Errorf("list of tables: %w", err)
+	}
+	for _, t := range tables {
+		if t.Name == tableName {
+			m.rConn.DelTable(t)
+		}
+	}
+
+	return m.rConn.Flush()
 }
 
-func (m *Manager) refreshRuleHandles(table *nftables.Table, chain *nftables.Chain) error {
-	if table == nil || chain == nil {
-		return nil
-	}
+// Flush rule/chain/set operations from the buffer
+//
+// Method also get all rules after flush and refreshes handle values in the rulesets
+// todo review this method usage
+func (m *Manager) Flush() error {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
 
-	list, err := m.rConn.GetRules(table, chain)
+	return m.aclManager.Flush()
+}
+
+func (m *Manager) createWorkTable() (*nftables.Table, error) {
+	tables, err := m.rConn.ListTablesOfFamily(nftables.TableFamilyIPv4)
 	if err != nil {
-		return err
+		return nil, fmt.Errorf("list of tables: %w", err)
 	}
 
-	for _, rule := range list {
-		if len(rule.UserData) != 0 {
-			if err := m.rulesetManager.setNftRuleHandle(rule); err != nil {
-				log.Errorf("failed to set rule handle: %v", err)
-			}
+	for _, t := range tables {
+		if t.Name == tableName {
+			m.rConn.DelTable(t)
 		}
 	}
 
-	return nil
+	table := m.rConn.AddTable(&nftables.Table{Name: tableName, Family: nftables.TableFamilyIPv4})
+	err = m.rConn.Flush()
+	return table, err
 }
 
 func (m *Manager) applyAllowNetbirdRules(chain *nftables.Chain) {
@@ -835,7 +234,7 @@ func (m *Manager) applyAllowNetbirdRules(chain *nftables.Chain) {
 				Kind: expr.VerdictAccept,
 			},
 		},
-		UserData: []byte(AllowNetbirdInputRuleID),
+		UserData: []byte(allowNetbirdInputRuleID),
 	}
 	_ = m.rConn.InsertRule(rule)
 }
@@ -857,15 +256,3 @@ func (m *Manager) detectAllowNetbirdRule(existedRules []*nftables.Rule) *nftable
 	}
 	return nil
 }
-
-func encodePort(port fw.Port) []byte {
-	bs := make([]byte, 2)
-	binary.BigEndian.PutUint16(bs, uint16(port.Values[0]))
-	return bs
-}
-
-func ifname(n string) []byte {
-	b := make([]byte, 16)
-	copy(b, []byte(n+"\x00"))
-	return b
-}