From cf70643818c9a71d83907cce361a6b89f1285a26 Mon Sep 17 00:00:00 2001
From: Nils Enkelmann <nils.enkelmann@tngtech.com>
Date: Mon, 7 Apr 2025 10:52:51 +0200
Subject: [PATCH] query for all nodes in ListNodes if no parameter is given

---
 hscontrol/db/node.go       | 17 +++++++----------
 hscontrol/db/node_test.go  | 14 ++++++++------
 hscontrol/mapper/mapper.go | 15 ++++++++++-----
 3 files changed, 25 insertions(+), 21 deletions(-)

diff --git a/hscontrol/db/node.go b/hscontrol/db/node.go
index 75f55dac..6bfe657c 100644
--- a/hscontrol/db/node.go
+++ b/hscontrol/db/node.go
@@ -58,26 +58,23 @@ func ListPeers(tx *gorm.DB, nodeID types.NodeID) (types.Nodes, error) {
 	return nodes, nil
 }
 
-func (hsdb *HSDatabase) ListNodes(nodeIDs ...types.NodeIDs) (types.Nodes, error) {
+// ListNodes queries the database for either all nodes if no parameters are given
+// or for the given nodes if at least one node ID is given as parameter
+func (hsdb *HSDatabase) ListNodes(nodeIDs ...types.NodeID) (types.Nodes, error) {
 	return Read(hsdb.DB, func(rx *gorm.DB) (types.Nodes, error) {
 		return ListNodes(rx, nodeIDs...)
 	})
 }
 
-func ListNodes(tx *gorm.DB, nodeIDs ...types.NodeIDs) (types.Nodes, error) {
-	if len(nodeIDs) > 0 && len(nodeIDs[0]) == 0 {
-		return types.Nodes{}, nil
-	}
-	var nodeFilter types.NodeIDs = nil
-	if len(nodeIDs) > 0 {
-		nodeFilter = nodeIDs[0]
-	}
+// ListNodes queries the database for either all nodes if no parameters are given
+// or for the given nodes if at least one node ID is given as parameter
+func ListNodes(tx *gorm.DB, nodeIDs ...types.NodeID) (types.Nodes, error) {
 	nodes := types.Nodes{}
 	if err := tx.
 		Preload("AuthKey").
 		Preload("AuthKey.User").
 		Preload("User").
-		Where(nodeFilter).Find(&nodes).Error; err != nil {
+		Where(nodeIDs).Find(&nodes).Error; err != nil {
 		return nil, err
 	}
 
diff --git a/hscontrol/db/node_test.go b/hscontrol/db/node_test.go
index 4a51e70b..73650663 100644
--- a/hscontrol/db/node_test.go
+++ b/hscontrol/db/node_test.go
@@ -814,24 +814,26 @@ func TestListNodes(t *testing.T) {
 	assert.Equal(t, "test1", nodes[0].Hostname)
 	assert.Equal(t, "test2", nodes[1].Hostname)
 
-	// Empty node list should return empty list
-	nodes, err = db.ListNodes(types.NodeIDs{})
+	// Empty node list should return all nodes
+	nodes, err = db.ListNodes(types.NodeIDs{}...)
 	require.NoError(t, err)
-	assert.Equal(t, len(nodes), 0)
+	assert.Equal(t, len(nodes), 2)
+	assert.Equal(t, "test1", nodes[0].Hostname)
+	assert.Equal(t, "test2", nodes[1].Hostname)
 
 	// No match in IDs should return empty list and no error
-	nodes, err = db.ListNodes(types.NodeIDs{3, 4, 5})
+	nodes, err = db.ListNodes(types.NodeIDs{3, 4, 5}...)
 	require.NoError(t, err)
 	assert.Equal(t, len(nodes), 0)
 
 	// Partial match in IDs
-	nodes, err = db.ListNodes(types.NodeIDs{2, 3})
+	nodes, err = db.ListNodes(types.NodeIDs{2, 3}...)
 	require.NoError(t, err)
 	assert.Equal(t, len(nodes), 1)
 	assert.Equal(t, "test2", nodes[0].Hostname)
 
 	// Several matched IDs
-	nodes, err = db.ListNodes(types.NodeIDs{1, 2, 3})
+	nodes, err = db.ListNodes(types.NodeIDs{1, 2, 3}...)
 	require.NoError(t, err)
 	assert.Equal(t, len(nodes), 2)
 	assert.Equal(t, "test1", nodes[0].Hostname)
diff --git a/hscontrol/mapper/mapper.go b/hscontrol/mapper/mapper.go
index b24e9577..0b5d5d93 100644
--- a/hscontrol/mapper/mapper.go
+++ b/hscontrol/mapper/mapper.go
@@ -255,6 +255,7 @@ func (m *Mapper) PeerChangedResponse(
 	patches []*tailcfg.PeerChange,
 	messages ...string,
 ) ([]byte, error) {
+	var err error
 	resp := m.baseMapResponse()
 
 	var removedIDs []tailcfg.NodeID
@@ -268,10 +269,12 @@ func (m *Mapper) PeerChangedResponse(
 			removedIDs = append(removedIDs, nodeID.NodeID())
 		}
 	}
-
-	changedNodes, err := m.ListNodes(changedIDs)
-	if err != nil {
-		return nil, err
+	changedNodes := types.Nodes{}
+	if len(changedIDs) > 0 {
+		changedNodes, err = m.ListNodes(changedIDs...)
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	err = appendPeerChanges(
@@ -491,7 +494,9 @@ func (m *Mapper) ListPeers(nodeID types.NodeID) (types.Nodes, error) {
 	return peers, nil
 }
 
-func (m *Mapper) ListNodes(nodeIDs ...types.NodeIDs) (types.Nodes, error) {
+// ListNodes queries the database for either all nodes if no parameters are given
+// or for the given nodes if at least one node ID is given as parameter
+func (m *Mapper) ListNodes(nodeIDs ...types.NodeID) (types.Nodes, error) {
 	nodes, err := m.db.ListNodes(nodeIDs...)
 	if err != nil {
 		return nil, err