Make firewall reload when unsafe networks in the cert changes

firewall.go

@@ -58,8 +58,9 @@ type Firewall struct {
 	routableNetworks *bart.Lite
 
 	// assignedNetworks is a list of vpn networks assigned to us in the certificate.
-	assignedNetworks  []netip.Prefix
-	hasUnsafeNetworks bool
+	assignedNetworks []netip.Prefix
+	// unsafeNetworks is the list of unsafe networks issued to us in the certificate
+	unsafeNetworks []netip.Prefix
 
 	rules        string
 	rulesVersion uint16
@@ -158,10 +159,9 @@ func NewFirewall(l *slog.Logger, tcpTimeout, UDPTimeout, defaultTimeout time.Dur
 		assignedNetworks = append(assignedNetworks, network)
 	}
 
-	hasUnsafeNetworks := false
-	for _, n := range c.UnsafeNetworks() {
+	unsafeNetworks := c.UnsafeNetworks()
+	for _, n := range unsafeNetworks {
 		routableNetworks.Insert(n)
-		hasUnsafeNetworks = true
 	}
 
 	return &Firewall{
@@ -169,15 +169,15 @@ func NewFirewall(l *slog.Logger, tcpTimeout, UDPTimeout, defaultTimeout time.Dur
 			Conns:      make(map[firewall.Packet]*conn),
 			TimerWheel: NewTimerWheel[firewall.Packet](tmin, tmax),
 		},
-		InRules:           newFirewallTable(),
-		OutRules:          newFirewallTable(),
-		TCPTimeout:        tcpTimeout,
-		UDPTimeout:        UDPTimeout,
-		DefaultTimeout:    defaultTimeout,
-		routableNetworks:  routableNetworks,
-		assignedNetworks:  assignedNetworks,
-		hasUnsafeNetworks: hasUnsafeNetworks,
-		l:                 l,
+		InRules:          newFirewallTable(),
+		OutRules:         newFirewallTable(),
+		TCPTimeout:       tcpTimeout,
+		UDPTimeout:       UDPTimeout,
+		DefaultTimeout:   defaultTimeout,
+		routableNetworks: routableNetworks,
+		assignedNetworks: assignedNetworks,
+		unsafeNetworks:   unsafeNetworks,
+		l:                l,
 
 		incomingMetrics: firewallMetrics{
 			droppedLocalAddr:  metrics.GetOrRegisterCounter("firewall.incoming.dropped.local_addr", nil),
@@ -897,7 +897,7 @@ func (flc *firewallLocalCIDR) addRule(f *Firewall, localCidr string) error {
 	}
 
 	if localCidr == "" {
-		if !f.hasUnsafeNetworks || f.defaultLocalCIDRAny {
+		if len(f.unsafeNetworks) == 0 || f.defaultLocalCIDRAny {
 			flc.Any = true
 			return nil
 		}