move logic for validating node names (#2127)

* move logic for validating node names

this commits moves the generation of "given names" of nodes
into the registration function, and adds validation of renames
to RenameNode using the same logic.

Fixes #2121

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

* fix double arg

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

---------

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

hscontrol/auth.go

@@ -66,7 +66,7 @@ func (h *Headscale) handleRegister(
 	regReq tailcfg.RegisterRequest,
 	machineKey key.MachinePublic,
 ) {
-	logInfo, logTrace, logErr := logAuthFunc(regReq, machineKey)
+	logInfo, logTrace, _ := logAuthFunc(regReq, machineKey)
 	now := time.Now().UTC()
 	logTrace("handleRegister called, looking up machine in DB")
 	node, err := h.db.GetNodeByAnyKey(machineKey, regReq.NodeKey, regReq.OldNodeKey)
@@ -105,16 +105,6 @@ func (h *Headscale) handleRegister(
 
 		logInfo("Node not found in database, creating new")
 
-		givenName, err := h.db.GenerateGivenName(
-			machineKey,
-			regReq.Hostinfo.Hostname,
-		)
-		if err != nil {
-			logErr(err, "Failed to generate given name for node")
-
-			return
-		}
-
 		// The node did not have a key to authenticate, which means
 		// that we rely on a method that calls back some how (OpenID or CLI)
 		// We create the node and then keep it around until a callback
@@ -122,7 +112,6 @@ func (h *Headscale) handleRegister(
 		newNode := types.Node{
 			MachineKey: machineKey,
 			Hostname:   regReq.Hostinfo.Hostname,
-			GivenName:  givenName,
 			NodeKey:    regReq.NodeKey,
 			LastSeen:   &now,
 			Expiry:     &time.Time{},
@@ -354,21 +343,8 @@ func (h *Headscale) handleAuthKey(
 	} else {
 		now := time.Now().UTC()
 
-		givenName, err := h.db.GenerateGivenName(machineKey, registerRequest.Hostinfo.Hostname)
-		if err != nil {
-			log.Error().
-				Caller().
-				Str("func", "RegistrationHandler").
-				Str("hostinfo.name", registerRequest.Hostinfo.Hostname).
-				Err(err).
-				Msg("Failed to generate given name for node")
-
-			return
-		}
-
 		nodeToRegister := types.Node{
 			Hostname:       registerRequest.Hostinfo.Hostname,
-			GivenName:      givenName,
 			UserID:         pak.User.ID,
 			User:           pak.User,
 			MachineKey:     machineKey,

hscontrol/db/node.go

@@ -90,20 +90,6 @@ func (hsdb *HSDatabase) ListEphemeralNodes() (types.Nodes, error) {
 	})
 }
 
-func listNodesByGivenName(tx *gorm.DB, givenName string) (types.Nodes, error) {
-	nodes := types.Nodes{}
-	if err := tx.
-		Preload("AuthKey").
-		Preload("AuthKey.User").
-		Preload("User").
-		Preload("Routes").
-		Where("given_name = ?", givenName).Find(&nodes).Error; err != nil {
-		return nil, err
-	}
-
-	return nodes, nil
-}
-
 func (hsdb *HSDatabase) getNode(user string, name string) (*types.Node, error) {
 	return Read(hsdb.DB, func(rx *gorm.DB) (*types.Node, error) {
 		return getNode(rx, user, name)
@@ -242,9 +228,9 @@ func SetTags(
 }
 
 // RenameNode takes a Node struct and a new GivenName for the nodes
-// and renames it.
+// and renames it. If the name is not unique, it will return an error.
 func RenameNode(tx *gorm.DB,
-	nodeID uint64, newName string,
+	nodeID types.NodeID, newName string,
 ) error {
 	err := util.CheckForFQDNRules(
 		newName,
@@ -253,6 +239,15 @@ func RenameNode(tx *gorm.DB,
 		return fmt.Errorf("renaming node: %w", err)
 	}
 
+	uniq, err := isUnqiueName(tx, newName)
+	if err != nil {
+		return fmt.Errorf("checking if name is unique: %w", err)
+	}
+
+	if !uniq {
+		return fmt.Errorf("name is not unique: %s", newName)
+	}
+
 	if err := tx.Model(&types.Node{}).Where("id = ?", nodeID).Update("given_name", newName).Error; err != nil {
 		return fmt.Errorf("failed to rename node in the database: %w", err)
 	}
@@ -415,6 +410,15 @@ func RegisterNode(tx *gorm.DB, node types.Node, ipv4 *netip.Addr, ipv6 *netip.Ad
 	node.IPv4 = ipv4
 	node.IPv6 = ipv6
 
+	if node.GivenName == "" {
+		givenName, err := ensureUniqueGivenName(tx, node.Hostname)
+		if err != nil {
+			return nil, fmt.Errorf("failed to ensure unique given name: %w", err)
+		}
+
+		node.GivenName = givenName
+	}
+
 	if err := tx.Save(&node).Error; err != nil {
 		return nil, fmt.Errorf("failed register(save) node in the database: %w", err)
 	}
@@ -642,40 +646,32 @@ func generateGivenName(suppliedName string, randomSuffix bool) (string, error) {
 	return normalizedHostname, nil
 }
 
-func (hsdb *HSDatabase) GenerateGivenName(
+func isUnqiueName(tx *gorm.DB, name string) (bool, error) {
-	mkey key.MachinePublic,
+	nodes := types.Nodes{}
-	suppliedName string,
+	if err := tx.
-) (string, error) {
+		Where("given_name = ?", name).Find(&nodes).Error; err != nil {
-	return Read(hsdb.DB, func(rx *gorm.DB) (string, error) {
+		return false, err
-		return GenerateGivenName(rx, mkey, suppliedName)
+	}
-	})
+
+	return len(nodes) == 0, nil
 }
 
-func GenerateGivenName(
+func ensureUniqueGivenName(
 	tx *gorm.DB,
-	mkey key.MachinePublic,
+	name string,
-	suppliedName string,
 ) (string, error) {
-	givenName, err := generateGivenName(suppliedName, false)
+	givenName, err := generateGivenName(name, false)
 	if err != nil {
 		return "", err
 	}
 
-	// Tailscale rules (may differ) https://tailscale.com/kb/1098/machine-names/
+	unique, err := isUnqiueName(tx, givenName)
-	nodes, err := listNodesByGivenName(tx, givenName)
 	if err != nil {
 		return "", err
 	}
 
-	var nodeFound *types.Node
+	if !unique {
-	for idx, node := range nodes {
+		postfixedName, err := generateGivenName(name, true)
-		if node.GivenName == givenName {
-			nodeFound = nodes[idx]
-		}
-	}
-
-	if nodeFound != nil && nodeFound.MachineKey.String() != mkey.String() {
-		postfixedName, err := generateGivenName(suppliedName, true)
 		if err != nil {
 			return "", err
 		}

hscontrol/db/node_test.go

@@ -19,6 +19,7 @@ import (
 	"github.com/puzpuzpuz/xsync/v3"
 	"github.com/stretchr/testify/assert"
 	"gopkg.in/check.v1"
+	"gorm.io/gorm"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/key"
 	"tailscale.com/types/ptr"
@@ -313,51 +314,6 @@ func (s *Suite) TestExpireNode(c *check.C) {
 	c.Assert(nodeFromDB.IsExpired(), check.Equals, true)
 }
 
-func (s *Suite) TestGenerateGivenName(c *check.C) {
-	user1, err := db.CreateUser("user-1")
-	c.Assert(err, check.IsNil)
-
-	pak, err := db.CreatePreAuthKey(user1.Name, false, false, nil, nil)
-	c.Assert(err, check.IsNil)
-
-	_, err = db.getNode("user-1", "testnode")
-	c.Assert(err, check.NotNil)
-
-	nodeKey := key.NewNode()
-	machineKey := key.NewMachine()
-
-	machineKey2 := key.NewMachine()
-
-	node := &types.Node{
-		ID:             0,
-		MachineKey:     machineKey.Public(),
-		NodeKey:        nodeKey.Public(),
-		Hostname:       "hostname-1",
-		GivenName:      "hostname-1",
-		UserID:         user1.ID,
-		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      ptr.To(pak.ID),
-	}
-
-	trx := db.DB.Save(node)
-	c.Assert(trx.Error, check.IsNil)
-
-	givenName, err := db.GenerateGivenName(machineKey2.Public(), "hostname-2")
-	comment := check.Commentf("Same user, unique nodes, unique hostnames, no conflict")
-	c.Assert(err, check.IsNil, comment)
-	c.Assert(givenName, check.Equals, "hostname-2", comment)
-
-	givenName, err = db.GenerateGivenName(machineKey.Public(), "hostname-1")
-	comment = check.Commentf("Same user, same node, same hostname, no conflict")
-	c.Assert(err, check.IsNil, comment)
-	c.Assert(givenName, check.Equals, "hostname-1", comment)
-
-	givenName, err = db.GenerateGivenName(machineKey2.Public(), "hostname-1")
-	comment = check.Commentf("Same user, unique nodes, same hostname, conflict")
-	c.Assert(err, check.IsNil, comment)
-	c.Assert(givenName, check.Matches, fmt.Sprintf("^hostname-1-[a-z0-9]{%d}$", NodeGivenNameHashLength), comment)
-}
-
 func (s *Suite) TestSetTags(c *check.C) {
 	user, err := db.CreateUser("test")
 	c.Assert(err, check.IsNil)
@@ -778,3 +734,100 @@ func TestListEphemeralNodes(t *testing.T) {
 	assert.Equal(t, nodeEph.UserID, ephemeralNodes[0].UserID)
 	assert.Equal(t, nodeEph.Hostname, ephemeralNodes[0].Hostname)
 }
+
+func TestRenameNode(t *testing.T) {
+	db, err := newTestDB()
+	if err != nil {
+		t.Fatalf("creating db: %s", err)
+	}
+
+	user, err := db.CreateUser("test")
+	assert.NoError(t, err)
+
+	user2, err := db.CreateUser("test2")
+	assert.NoError(t, err)
+
+	node := types.Node{
+		ID:             0,
+		MachineKey:     key.NewMachine().Public(),
+		NodeKey:        key.NewNode().Public(),
+		Hostname:       "test",
+		UserID:         user.ID,
+		RegisterMethod: util.RegisterMethodAuthKey,
+	}
+
+	node2 := types.Node{
+		ID:             0,
+		MachineKey:     key.NewMachine().Public(),
+		NodeKey:        key.NewNode().Public(),
+		Hostname:       "test",
+		UserID:         user2.ID,
+		RegisterMethod: util.RegisterMethodAuthKey,
+	}
+
+	err = db.DB.Save(&node).Error
+	assert.NoError(t, err)
+
+	err = db.DB.Save(&node2).Error
+	assert.NoError(t, err)
+
+	err = db.DB.Transaction(func(tx *gorm.DB) error {
+		_, err := RegisterNode(tx, node, nil, nil)
+		if err != nil {
+			return err
+		}
+		_, err = RegisterNode(tx, node2, nil, nil)
+		return err
+	})
+	assert.NoError(t, err)
+
+	nodes, err := db.ListNodes()
+	assert.NoError(t, err)
+
+	assert.Len(t, nodes, 2)
+
+	t.Logf("node1 %s %s", nodes[0].Hostname, nodes[0].GivenName)
+	t.Logf("node2 %s %s", nodes[1].Hostname, nodes[1].GivenName)
+
+	assert.Equal(t, nodes[0].Hostname, nodes[0].GivenName)
+	assert.NotEqual(t, nodes[1].Hostname, nodes[1].GivenName)
+	assert.Equal(t, nodes[0].Hostname, nodes[1].Hostname)
+	assert.NotEqual(t, nodes[0].Hostname, nodes[1].GivenName)
+	assert.Contains(t, nodes[1].GivenName, nodes[0].Hostname)
+	assert.Equal(t, nodes[0].GivenName, nodes[1].Hostname)
+	assert.Len(t, nodes[0].Hostname, 4)
+	assert.Len(t, nodes[1].Hostname, 4)
+	assert.Len(t, nodes[0].GivenName, 4)
+	assert.Len(t, nodes[1].GivenName, 13)
+
+	// Nodes can be renamed to a unique name
+	err = db.Write(func(tx *gorm.DB) error {
+		return RenameNode(tx, nodes[0].ID, "newname")
+	})
+	assert.NoError(t, err)
+
+	nodes, err = db.ListNodes()
+	assert.NoError(t, err)
+	assert.Len(t, nodes, 2)
+	assert.Equal(t, nodes[0].Hostname, "test")
+	assert.Equal(t, nodes[0].GivenName, "newname")
+
+	// Nodes can reuse name that is no longer used
+	err = db.Write(func(tx *gorm.DB) error {
+		return RenameNode(tx, nodes[1].ID, "test")
+	})
+	assert.NoError(t, err)
+
+	nodes, err = db.ListNodes()
+	assert.NoError(t, err)
+	assert.Len(t, nodes, 2)
+	assert.Equal(t, nodes[0].Hostname, "test")
+	assert.Equal(t, nodes[0].GivenName, "newname")
+	assert.Equal(t, nodes[1].GivenName, "test")
+
+	// Nodes cannot be renamed to used names
+	err = db.Write(func(tx *gorm.DB) error {
+		return RenameNode(tx, nodes[0].ID, "test")
+	})
+	assert.ErrorContains(t, err, "name is not unique")
+}

hscontrol/grpcv1.go

@@ -373,7 +373,7 @@ func (api headscaleV1APIServer) RenameNode(
 	node, err := db.Write(api.h.db.DB, func(tx *gorm.DB) (*types.Node, error) {
 		err := db.RenameNode(
 			tx,
-			request.GetNodeId(),
+			types.NodeID(request.GetNodeId()),
 			request.GetNewName(),
 		)
 		if err != nil {
@@ -802,18 +802,12 @@ func (api headscaleV1APIServer) DebugCreateNode(
 		return nil, err
 	}
 
-	givenName, err := api.h.db.GenerateGivenName(mkey, request.GetName())
-	if err != nil {
-		return nil, err
-	}
-
 	nodeKey := key.NewNode()
 
 	newNode := types.Node{
 		MachineKey: mkey,
 		NodeKey:    nodeKey.Public(),
 		Hostname:   request.GetName(),
-		GivenName:  givenName,
 		User:       *user,
 
 		Expiry:   &time.Time{},