fix handling of empty network map during decode and encode

management/internals/shared/grpc/components_encoder.go

@@ -61,6 +61,8 @@ func EncodeNetworkMapEnvelope(in ComponentsEnvelopeInput) *proto.NetworkMapEnvel
 		return &proto.NetworkMapEnvelope{
 			Payload: &proto.NetworkMapEnvelope_Full{
 				Full: &proto.NetworkMapComponentsFull{
+					Serial:     networkSerial(c.Network),
+					Network:    toAccountNetwork(c.Network),
 					PeerConfig: in.PeerConfig,
 					// components.Peers always contains the target peer
 					Peers:            []*proto.PeerCompact{toPeerCompact(c.Peers[c.PeerID])},

management/internals/shared/grpc/components_encoder_test.go

@@ -758,6 +758,9 @@ func TestEncodeNetworkMapEnvelope_NilComponentsGracefulDegrade(t *testing.T) {
 	assert.Equal(t, "netbird.cloud", full.DnsDomain)
 	assert.Len(t, full.Peers, 1)
 	assert.Empty(t, full.Policies)
+	require.NotNil(t, full.Network, "client runs Calculate() over the envelope and dereferences Network unconditionally; a nil here would crash the receiver")
+	assert.Equal(t, "net-empty", full.Network.Identifier)
+	assert.Equal(t, uint64(9), full.Serial)
 }
 
 func TestEncodeNetworkMapEnvelope_AccountSettingsAlwaysEmitted(t *testing.T) {
@@ -776,6 +779,12 @@ func TestEncodeNetworkMapEnvelope_AccountSettingsAlwaysEmitted(t *testing.T) {
 func emptyNetworkMapComponents() *types.NetworkMapComponents {
 	return types.EmptyNetworkMapComponents(
 		&types.NetworkMapComponents{
-			PeerID: "peer-id", Peers: map[string]*types.ComponentPeer{"peer-id": {}}},
+			PeerID: "peer-id", Peers: map[string]*types.ComponentPeer{"peer-id": {}},
+			Network: &types.Network{
+				Identifier: "net-empty",
+				Net:        net.IPNet{IP: net.IP{100, 64, 0, 0}, Mask: net.CIDRMask(10, 32)},
+				Serial:     9,
+			},
+		},
 	)
 }

shared/management/networkmap/decode.go

@@ -228,15 +228,17 @@ func DecodeEnvelope(env *proto.NetworkMapEnvelope) (*types.NetworkMapComponents,
 	return c, nil
 }
 
+// decodeAccountNetwork never returns nil — Calculate() dereferences
+// c.Network unconditionally, and servers that predate the fix omit the field
+// entirely from the empty-components envelope.
 func decodeAccountNetwork(an *proto.AccountNetwork) *types.Network {
+	n := &types.Network{}
 	if an == nil {
-		return nil
-	}
-	n := &types.Network{
-		Identifier: an.Identifier,
-		Dns:        an.Dns,
-		Serial:     an.Serial,
+		return n
 	}
+	n.Identifier = an.Identifier
+	n.Dns = an.Dns
+	n.Serial = an.Serial
 	if an.NetCidr != "" {
 		if _, ipnet, err := net.ParseCIDR(an.NetCidr); err == nil && ipnet != nil {
 			n.Net = *ipnet

shared/management/networkmap/envelope_test.go

@@ -221,6 +221,66 @@ func TestEnvelopeRoundTrip_AllGroupShortCircuitParity(t *testing.T) {
 		"client-side Calculate must connect the same remote peers as the server")
 }
 
+// TestEnvelopeToNetworkMap_EmptyComponents covers the graceful-degrade path
+// the server takes for a peer that is missing from the account or absent from
+// the validated-peers map. The legacy server short-circuited before
+// Calculate() and shipped a NetworkMap carrying only the account Network; the
+// components path runs Calculate() on the client instead, so the envelope must
+// carry Network or the client panics dereferencing a nil *types.Network.
+func TestEnvelopeToNetworkMap_EmptyComponents(t *testing.T) {
+	localPeerKey := randomWgKey(t)
+	c := types.EmptyNetworkMapComponents(&types.NetworkMapComponents{
+		PeerID: "peer-A",
+		Network: &types.Network{
+			Identifier: "net-empty",
+			Net:        net.IPNet{IP: net.IP{100, 64, 0, 0}, Mask: net.CIDRMask(10, 32)},
+			Serial:     7,
+		},
+		Peers: map[string]*types.ComponentPeer{
+			"peer-A": {ID: "peer-A", Key: localPeerKey, IP: netip.AddrFrom4([4]byte{100, 64, 0, 1})},
+		},
+	})
+
+	envelope := mgmtgrpc.EncodeNetworkMapEnvelope(mgmtgrpc.ComponentsEnvelopeInput{
+		Components: c,
+		DNSDomain:  "netbird.cloud",
+	})
+	require.NotNil(t, envelope.GetFull().Network, "empty envelope must carry the account Network")
+
+	wire, err := goproto.Marshal(envelope)
+	require.NoError(t, err, "marshal envelope")
+	var decoded proto.NetworkMapEnvelope
+	require.NoError(t, goproto.Unmarshal(wire, &decoded), "unmarshal envelope")
+
+	result, err := nbnetworkmap.EnvelopeToNetworkMap(context.Background(), &decoded, localPeerKey, "netbird.cloud")
+	require.NoError(t, err, "EnvelopeToNetworkMap must degrade gracefully on empty components")
+	require.Equal(t, uint64(7), result.NetworkMap.Serial)
+	require.Empty(t, result.NetworkMap.RemotePeers, "unvalidated peer connects to nobody")
+}
+
+// TestEnvelopeToNetworkMap_MissingNetwork simulates a server that omits
+// AccountNetwork from the envelope. Clients must degrade rather than panic, so
+// they survive talking to a management server that predates the encoder fix.
+func TestEnvelopeToNetworkMap_MissingNetwork(t *testing.T) {
+	c, localPeerKey := buildSmokeComponents(t)
+
+	envelope := mgmtgrpc.EncodeNetworkMapEnvelope(mgmtgrpc.ComponentsEnvelopeInput{
+		Components: c,
+		DNSDomain:  "netbird.cloud",
+	})
+	envelope.GetFull().Network = nil
+
+	wire, err := goproto.Marshal(envelope)
+	require.NoError(t, err, "marshal envelope")
+	var decoded proto.NetworkMapEnvelope
+	require.NoError(t, goproto.Unmarshal(wire, &decoded), "unmarshal envelope")
+
+	result, err := nbnetworkmap.EnvelopeToNetworkMap(context.Background(), &decoded, localPeerKey, "netbird.cloud")
+	require.NoError(t, err, "a missing AccountNetwork must not panic the client")
+	require.NotNil(t, result.Components.Network)
+	require.NotEmpty(t, result.NetworkMap.RemotePeers, "the rest of the snapshot stays usable")
+}
+
 // buildSmokeComponents returns a minimal NetworkMapComponents (2 peers, 1
 // group, 1 allow policy) plus the receiving peer's WG public key. Sufficient
 // to validate the encode → marshal → decode → Calculate pipeline produces