[client] Add IPv6 support to ACL manager, USP filter, and forwarder (#5688)

client/firewall/iptables/acl_linux.go

@@ -36,6 +36,7 @@ type aclManager struct {
 	entries         aclEntries
 	optionalEntries map[string][]entry
 	ipsetStore      *ipsetStore
+	v6              bool
 
 	stateManager *statemanager.Manager
 }
@@ -47,6 +48,7 @@ func newAclManager(iptablesClient *iptables.IPTables, wgIface iFaceMapper) (*acl
 		entries:         make(map[string][][]string),
 		optionalEntries: make(map[string][]entry),
 		ipsetStore:      newIpsetStore(),
+		v6:              iptablesClient.Proto() == iptables.ProtocolIPv6,
 	}, nil
 }
 
@@ -81,7 +83,11 @@ func (m *aclManager) AddPeerFiltering(
 	chain := chainNameInputRules
 
 	ipsetName = transformIPsetName(ipsetName, sPort, dPort, action)
-	specs := filterRuleSpecs(ip, string(protocol), sPort, dPort, action, ipsetName)
+	if m.v6 && ipsetName != "" {
+		ipsetName += "-v6"
+	}
+	proto := protoForFamily(protocol, m.v6)
+	specs := filterRuleSpecs(ip, proto, sPort, dPort, action, ipsetName)
 
 	mangleSpecs := slices.Clone(specs)
 	mangleSpecs = append(mangleSpecs,
@@ -105,6 +111,7 @@ func (m *aclManager) AddPeerFiltering(
 				ip:        ip.String(),
 				chain:     chain,
 				specs:     specs,
+				v6:        m.v6,
 			}}, nil
 		}
 
@@ -157,6 +164,7 @@ func (m *aclManager) AddPeerFiltering(
 		ipsetName:   ipsetName,
 		ip:          ip.String(),
 		chain:       chain,
+		v6:          m.v6,
 	}
 
 	m.updateState()
@@ -376,8 +384,13 @@ func (m *aclManager) updateState() {
 	currentState.Lock()
 	defer currentState.Unlock()
 
-	currentState.ACLEntries = m.entries
-	currentState.ACLIPsetStore = m.ipsetStore
+	if m.v6 {
+		currentState.ACLEntries6 = m.entries
+		currentState.ACLIPsetStore6 = m.ipsetStore
+	} else {
+		currentState.ACLEntries = m.entries
+		currentState.ACLIPsetStore = m.ipsetStore
+	}
 
 	if err := m.stateManager.UpdateState(currentState); err != nil {
 		log.Errorf("failed to update state: %v", err)
@@ -385,6 +398,15 @@ func (m *aclManager) updateState() {
 }
 
 // filterRuleSpecs returns the specs of a filtering rule
+// protoForFamily translates ICMP to ICMPv6 for ip6tables.
+// ip6tables requires "ipv6-icmp" (or "icmpv6") instead of "icmp".
+func protoForFamily(protocol firewall.Protocol, v6 bool) string {
+	if v6 && protocol == firewall.ProtocolICMP {
+		return "ipv6-icmp"
+	}
+	return string(protocol)
+}
+
 func filterRuleSpecs(ip net.IP, protocol string, sPort, dPort *firewall.Port, action firewall.Action, ipsetName string) (specs []string) {
 	// don't use IP matching if IP is 0.0.0.0
 	matchByIP := !ip.IsUnspecified()
@@ -437,6 +459,9 @@ func (m *aclManager) createIPSet(name string) error {
 	opts := ipset.CreateOptions{
 		Replace: true,
 	}
+	if m.v6 {
+		opts.Family = ipset.FamilyIPV6
+	}
 
 	if err := ipset.Create(name, ipset.TypeHashNet, opts); err != nil {
 		return fmt.Errorf("create ipset %s: %w", name, err)