Revert "[client] Skip engine restart when default route is unchanged"

This reverts commit a071b55f35.

client/internal/engine.go

@@ -1066,7 +1066,7 @@ func (e *Engine) updateChecksIfNew(checks []*mgmProto.Checks) error {
 	}
 	e.checks = checks
 
-	info, err := system.GetInfoWithChecks(e.ctx, checks)
+	info, err := system.GetInfoWithChecks(e.ctx, checks, e.overlayAddresses()...)
 	if err != nil {
 		log.Warnf("failed to get system info with checks: %v", err)
 		info = system.GetInfo(e.ctx)
@@ -1097,6 +1097,20 @@ func (e *Engine) updateChecksIfNew(checks []*mgmProto.Checks) error {
 	return nil
 }
 
+// overlayAddresses returns our own WireGuard overlay address (v4 and v6) so it
+// can be excluded from the reported network addresses; the interface coming and
+// going otherwise churns the peer meta on the management server.
+func (e *Engine) overlayAddresses() []netip.Addr {
+	var ips []netip.Addr
+	if e.config.WgAddr.IP.IsValid() {
+		ips = append(ips, e.config.WgAddr.IP)
+	}
+	if e.config.WgAddr.HasIPv6() {
+		ips = append(ips, e.config.WgAddr.IPv6)
+	}
+	return ips
+}
+
 func (e *Engine) updateConfig(conf *mgmProto.PeerConfig) error {
 	if e.wgInterface == nil {
 		return errors.New("wireguard interface is not initialized")
@@ -1240,7 +1254,7 @@ func (e *Engine) receiveManagementEvents() {
 	e.shutdownWg.Add(1)
 	go func() {
 		defer e.shutdownWg.Done()
-		info, err := system.GetInfoWithChecks(e.ctx, e.checks)
+		info, err := system.GetInfoWithChecks(e.ctx, e.checks, e.overlayAddresses()...)
 		if err != nil {
 			log.Warnf("failed to get system info with checks: %v", err)
 			info = system.GetInfo(e.ctx)

client/system/info.go

@@ -3,6 +3,7 @@ package system
 import (
 	"context"
 	"net/netip"
+	"slices"
 	"strings"
 
 	log "github.com/sirupsen/logrus"
@@ -121,6 +122,23 @@ func (i *Info) SetFlags(
 	}
 }
 
+// removeAddresses drops network addresses whose IP matches any of the given
+// addresses, regardless of prefix length. Used to exclude the NetBird overlay
+// address, which otherwise churns the meta as the interface comes and goes.
+func (i *Info) removeAddresses(ips ...netip.Addr) {
+	if len(ips) == 0 {
+		return
+	}
+	filtered := i.NetworkAddresses[:0]
+	for _, addr := range i.NetworkAddresses {
+		if slices.Contains(ips, addr.NetIP.Addr()) {
+			continue
+		}
+		filtered = append(filtered, addr)
+	}
+	i.NetworkAddresses = filtered
+}
+
 // extractUserAgent extracts Netbird's agent (client) name and version from the outgoing context
 func extractUserAgent(ctx context.Context) string {
 	md, hasMeta := metadata.FromOutgoingContext(ctx)
@@ -147,7 +165,9 @@ func extractDeviceName(ctx context.Context, defaultName string) string {
 }
 
 // GetInfoWithChecks retrieves and parses the system information with applied checks.
-func GetInfoWithChecks(ctx context.Context, checks []*proto.Checks) (*Info, error) {
+// excludeIPs are dropped from the reported network addresses (e.g. our own
+// WireGuard overlay address, which otherwise churns the peer meta).
+func GetInfoWithChecks(ctx context.Context, checks []*proto.Checks, excludeIPs ...netip.Addr) (*Info, error) {
 	log.Debugf("gathering system information with checks: %d", len(checks))
 	processCheckPaths := make([]string, 0)
 	for _, check := range checks {
@@ -162,6 +182,7 @@ func GetInfoWithChecks(ctx context.Context, checks []*proto.Checks) (*Info, erro
 
 	info := GetInfo(ctx)
 	info.Files = files
+	info.removeAddresses(excludeIPs...)
 
 	log.Debugf("all system information gathered successfully")
 	return info, nil

client/system/info_test.go

@@ -2,6 +2,7 @@ package system
 
 import (
 	"context"
+	"net/netip"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -43,3 +44,42 @@ func Test_NetAddresses(t *testing.T) {
 		t.Errorf("no network addresses found")
 	}
 }
+
+func TestInfo_RemoveAddresses(t *testing.T) {
+	addr := func(cidr string) NetworkAddress {
+		return NetworkAddress{NetIP: netip.MustParsePrefix(cidr)}
+	}
+
+	info := &Info{
+		NetworkAddresses: []NetworkAddress{
+			addr("192.168.1.7/24"),
+			addr("100.76.70.97/32"),                          // overlay v4 (host mask /32)
+			addr("2001:818:c51b:4800:845:a65d:ae6f:623f/64"), // real global v6
+			addr("fd00:1234::1/64"),                          // overlay v6
+		},
+	}
+
+	// Overlay addresses as the engine knows them, with a different mask (/16, /64).
+	info.removeAddresses(
+		netip.MustParseAddr("100.76.70.97"),
+		netip.MustParseAddr("fd00:1234::1"),
+	)
+
+	want := []string{"192.168.1.7/24", "2001:818:c51b:4800:845:a65d:ae6f:623f/64"}
+	if len(info.NetworkAddresses) != len(want) {
+		t.Fatalf("got %d addresses, want %d: %v", len(info.NetworkAddresses), len(want), info.NetworkAddresses)
+	}
+	for i, w := range want {
+		if got := info.NetworkAddresses[i].NetIP.String(); got != w {
+			t.Errorf("address[%d] = %s, want %s", i, got, w)
+		}
+	}
+}
+
+func TestInfo_RemoveAddresses_NoOp(t *testing.T) {
+	info := &Info{NetworkAddresses: []NetworkAddress{{NetIP: netip.MustParsePrefix("10.0.0.1/24")}}}
+	info.removeAddresses()
+	if len(info.NetworkAddresses) != 1 {
+		t.Errorf("expected no change with empty input, got %v", info.NetworkAddresses)
+	}
+}

client/system/network_addr.go

@@ -46,7 +46,9 @@ func toNetworkAddress(address net.Addr, mac string) (NetworkAddress, bool) {
 	if !ok {
 		return NetworkAddress{}, false
 	}
-	if ipNet.IP.IsLoopback() {
+	// Skip link-local and multicast: they carry no routable peer info and the
+	// IPv6 link-local of a flapping NIC churns the meta on every up/down.
+	if ipNet.IP.IsLoopback() || ipNet.IP.IsLinkLocalUnicast() || ipNet.IP.IsMulticast() {
 		return NetworkAddress{}, false
 	}
 	prefix, err := netip.ParsePrefix(ipNet.String())

client/system/network_addr_test.go

@@ -0,0 +1,45 @@
+//go:build !ios
+
+package system
+
+import (
+	"net"
+	"testing"
+)
+
+func mustIPNet(t *testing.T, cidr string) *net.IPNet {
+	t.Helper()
+	ip, ipNet, err := net.ParseCIDR(cidr)
+	if err != nil {
+		t.Fatalf("parse %q: %v", cidr, err)
+	}
+	ipNet.IP = ip
+	return ipNet
+}
+
+func TestToNetworkAddress_Filtering(t *testing.T) {
+	const mac = "c8:4b:d6:b6:04:ac"
+
+	tests := []struct {
+		name string
+		cidr string
+		want bool
+	}{
+		{"ipv4 global", "10.65.16.181/23", true},
+		{"ipv6 global", "2620:52:0:4110:102d:6a98:ee75:8b92/64", true},
+		{"ipv4 loopback", "127.0.0.1/8", false},
+		{"ipv6 loopback", "::1/128", false},
+		{"ipv6 link-local", "fe80::871:4c25:23d7:2529/64", false},
+		{"ipv4 link-local", "169.254.1.2/16", false},
+		{"ipv6 multicast", "ff02::1/128", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_, got := toNetworkAddress(mustIPNet(t, tt.cidr), mac)
+			if got != tt.want {
+				t.Errorf("toNetworkAddress(%s) ok = %v, want %v", tt.cidr, got, tt.want)
+			}
+		})
+	}
+}