From 3aa891b29c1d108ee395df9c4b3bbb5a42d87c52 Mon Sep 17 00:00:00 2001
From: abhishek9686 <abhi281342@gmail.com>
Date: Sat, 20 Jun 2026 17:40:43 +0530
Subject: [PATCH] NM-363: prevent restart loop on repeated IPv6 endpoint
 detection

---
 functions/daemon.go       |  6 ++++++
 functions/mqpublish.go    | 40 +++++++++++++++++++++++++++++++--------
 ncutils/netclientutils.go | 15 +++++++++++++++
 3 files changed, 53 insertions(+), 8 deletions(-)

diff --git a/functions/daemon.go b/functions/daemon.go
index 3ffacbbf..ee9dd3d3 100644
--- a/functions/daemon.go
+++ b/functions/daemon.go
@@ -212,6 +212,12 @@ func startGoRoutines(wg *sync.WaitGroup) context.CancelFunc {
 	}
 
 	if !netclientCfg.IsStatic {
+		if netclientCfg.EndpointIP != nil {
+			config.HostPublicIP = netclientCfg.EndpointIP
+		}
+		if netclientCfg.EndpointIPv6 != nil {
+			config.HostPublicIP6 = netclientCfg.EndpointIPv6
+		}
 		// IPV4
 		config.HostPublicIP, config.WgPublicListenPort, config.HostNatType = holePunchWgPort(4, netclientCfg.ListenPort)
 		slog.Info("wireguard public listen port: ", "port", config.WgPublicListenPort)
diff --git a/functions/mqpublish.go b/functions/mqpublish.go
index 4649ab3d..4960c5ef 100644
--- a/functions/mqpublish.go
+++ b/functions/mqpublish.go
@@ -66,6 +66,14 @@ func Checkin(ctx context.Context, wg *sync.WaitGroup) {
 
 	ipTicker = time.NewTicker(time.Second * time.Duration(ipTickerIntervalSec))
 	defer ipTicker.Stop()
+	if !config.Netclient().IsStatic && config.Netclient().CurrGwNmIP == nil {
+		if config.HostPublicIP == nil && config.Netclient().EndpointIP != nil {
+			config.HostPublicIP = config.Netclient().EndpointIP
+		}
+		if config.HostPublicIP6 == nil && config.Netclient().EndpointIPv6 != nil {
+			config.HostPublicIP6 = config.Netclient().EndpointIPv6
+		}
+	}
 	err := hostServerUpdate(models.HostUpdate{Action: models.UpdateHost})
 	if err != nil {
 		logger.Log(0, "could not publish endpoint change", err.Error())
@@ -102,20 +110,36 @@ func Checkin(ctx context.Context, wg *sync.WaitGroup) {
 				if ip4 == nil && ip6 == nil {
 					continue
 				}
-				if ip4 != nil && ip4.To4() != nil && !ip4.IsUnspecified() && !config.HostPublicIP.Equal(ip4) {
-					slog.Debug("IP CHECKIN 1", "ipv4", ip4, "HostPublicIP", config.HostPublicIP)
-					config.HostPublicIP = ip4
-					restart = true
+				knownIP4 := config.HostPublicIP
+				if knownIP4 == nil {
+					knownIP4 = config.Netclient().EndpointIP
+				}
+				if ip4 != nil && ip4.To4() != nil && !ip4.IsUnspecified() {
+					if !ncutils.IPsEqual(knownIP4, ip4) {
+						slog.Debug("IP CHECKIN 1", "ipv4", ip4, "HostPublicIP", config.HostPublicIP)
+						config.HostPublicIP = ip4
+						restart = true
+					} else if config.HostPublicIP == nil {
+						config.HostPublicIP = ip4
+					}
 				} else if ip4 == nil && config.HostPublicIP != nil {
 					slog.Debug("IP CHECKIN 2", "ipv4", ip4, "HostPublicIP", config.HostPublicIP)
 					config.HostPublicIP = nil
 					restart = true
 				}
 
-				if ip6 != nil && ip6.To16() != nil && !ip6.IsUnspecified() && !config.HostPublicIP6.Equal(ip6) {
-					slog.Debug("IP CHECKIN 1", "ipv6", ip6, "HostPublicIP6", config.HostPublicIP6)
-					config.HostPublicIP6 = ip6
-					restart = true
+				knownIP6 := config.HostPublicIP6
+				if knownIP6 == nil {
+					knownIP6 = config.Netclient().EndpointIPv6
+				}
+				if ip6 != nil && ip6.To16() != nil && !ip6.IsUnspecified() {
+					if !ncutils.IPsEqual(knownIP6, ip6) {
+						slog.Debug("IP CHECKIN 1", "ipv6", ip6, "HostPublicIP6", config.HostPublicIP6)
+						config.HostPublicIP6 = ip6
+						restart = true
+					} else if config.HostPublicIP6 == nil {
+						config.HostPublicIP6 = ip6
+					}
 				} else if ip6 == nil && config.HostPublicIP6 != nil {
 					slog.Debug("IP CHECKIN 2", "ipv6", ip6, "HostPublicIP6", config.HostPublicIP6)
 					config.HostPublicIP6 = nil
diff --git a/ncutils/netclientutils.go b/ncutils/netclientutils.go
index eaeca687..57400469 100644
--- a/ncutils/netclientutils.go
+++ b/ncutils/netclientutils.go
@@ -360,6 +360,21 @@ func SetVerbosity(logLevel int) {
 
 }
 
+// IPsEqual compares two IP addresses, normalizing IPv4 and IPv6 representations.
+func IPsEqual(a, b net.IP) bool {
+	if a == nil && b == nil {
+		return true
+	}
+	if a == nil || b == nil {
+		return false
+	}
+	a16, b16 := a.To16(), b.To16()
+	if a16 == nil || b16 == nil {
+		return a.Equal(b)
+	}
+	return a16.Equal(b16)
+}
+
 func TraceCaller() {
 	// Skip 1 frame to get the caller of this function
 	pc, file, line, ok := runtime.Caller(2)