From 299cef4e996fbaced5408883b63a794133112e49 Mon Sep 17 00:00:00 2001
From: Andrey Bobelev <andrey@bobelev.com>
Date: Tue, 28 Oct 2025 11:19:14 +0200
Subject: [PATCH] fix: free ips from usedIps ipset on DeleteNode

---
 hscontrol/db/ip.go       | 9 +++++++++
 hscontrol/state/state.go | 2 ++
 2 files changed, 11 insertions(+)

diff --git a/hscontrol/db/ip.go b/hscontrol/db/ip.go
index 244bb3db..972d8e72 100644
--- a/hscontrol/db/ip.go
+++ b/hscontrol/db/ip.go
@@ -341,3 +341,12 @@ func (db *HSDatabase) BackfillNodeIPs(i *IPAllocator) ([]string, error) {
 
 	return ret, err
 }
+
+func (i *IPAllocator) FreeIPs(ips []netip.Addr) {
+	i.mu.Lock()
+	defer i.mu.Unlock()
+
+	for _, ip := range ips {
+		i.usedIPs.Remove(ip)
+	}
+}
diff --git a/hscontrol/state/state.go b/hscontrol/state/state.go
index 297004fc..6ef11f54 100644
--- a/hscontrol/state/state.go
+++ b/hscontrol/state/state.go
@@ -429,6 +429,8 @@ func (s *State) DeleteNode(node types.NodeView) (change.ChangeSet, error) {
 		return change.EmptySet, err
 	}
 
+	s.ipAlloc.FreeIPs(node.IPs())
+
 	c := change.NodeRemoved(node.ID())
 
 	// Check if policy manager needs updating after node deletion