From ad4c11aca17a09c80be86697c4cc5c0965937e57 Mon Sep 17 00:00:00 2001
From: Andrew Dunham <andrew@du.nham.ca>
Date: Tue, 12 Sep 2023 17:04:09 -0400
Subject: [PATCH] net/netmon: log when the gateway/self IP changes

This logs that the gateway/self IP address has changed if one of the new
values differs.

Updates #8992

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I0919424b68ad97fbe1204dd36317ed6f5915411f
---
 net/netmon/netmon.go | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/net/netmon/netmon.go b/net/netmon/netmon.go
index 64dffd26d..b0872034a 100644
--- a/net/netmon/netmon.go
+++ b/net/netmon/netmon.go
@@ -174,8 +174,14 @@ func (m *Monitor) GatewayAndSelfIP() (gw, myIP netip.Addr, ok bool) {
 		return m.gw, m.gwSelfIP, true
 	}
 	gw, myIP, ok = interfaces.LikelyHomeRouterIP()
+	changed := false
 	if ok {
-		m.gw, m.gwSelfIP, m.gwValid = gw, myIP, true
+		changed = m.gw != gw || m.gwSelfIP != myIP
+		m.gw, m.gwSelfIP = gw, myIP
+		m.gwValid = true
+	}
+	if changed {
+		m.logf("gateway and self IP changed: gw=%v self=%v", m.gw, m.gwSelfIP)
 	}
 	return gw, myIP, ok
 }