Add support for IPv6 networks (on Linux clients)

client/firewall/create.go

@@ -30,3 +30,7 @@ func NewFirewall(context context.Context, iface IFaceMapper) (firewall.Manager,
 	}
 	return fm, nil
 }
+
+func SupportsIPv6() bool {
+	return false
+}

client/firewall/create_linux.go

@@ -83,6 +83,10 @@ func NewFirewall(context context.Context, iface IFaceMapper) (firewall.Manager,
 	return fm, nil
 }
 
+func SupportsIPv6() bool {
+	return check() == NFTABLES
+}
+
 // check returns the firewall type based on common lib checks. It returns UNKNOWN if no firewall is found.
 func check() FWType {
 	nf := nftables.Conn{}

client/firewall/iface.go

@@ -6,6 +6,7 @@ import "github.com/netbirdio/netbird/iface"
 type IFaceMapper interface {
 	Name() string
 	Address() iface.WGAddress
+	Address6() *iface.WGAddress
 	IsUserspaceBind() bool
 	SetFilter(iface.PacketFilter) error
 }

client/firewall/iptables/manager_linux.go

@@ -24,6 +24,10 @@ type Manager struct {
 	router     *routerManager
 }
 
+func (m *Manager) ResetV6RulesAndAddr() error {
+	return nil
+}
+
 // iFaceMapper defines subset methods of interface required for manager
 type iFaceMapper interface {
 	Name() string

client/firewall/manager/firewall.go

@@ -76,6 +76,10 @@ type Manager interface {
 	// RemoveRoutingRules removes a routing firewall rule
 	RemoveRoutingRules(pair RouterPair) error
 
+	// UpdateV6Address makes changes to the firewall to adapt to the IP address changes.
+	// It is expected that after calling this method ApplyFiltering will be called to re-add the firewall rules.
+	ResetV6RulesAndAddr() error
+
 	// Reset firewall to the default state
 	Reset() error