ipn/ipnlocal,ipnserver: rename {,Set}CurrentUser to {,Set}CurrentUserID

Address comments from https://github.com/tailscale/tailscale/pull/6506#discussion_r1032454064

Signed-off-by: Maisem Ali <maisem@tailscale.com>

ipn/ipnlocal/local.go

@@ -2039,7 +2039,7 @@ func (b *LocalBackend) InServerMode() bool {
 func (b *LocalBackend) CheckIPNConnectionAllowed(ci *ipnauth.ConnIdentity) error {
 	b.mu.Lock()
 	defer b.mu.Unlock()
-	serverModeUid := b.pm.CurrentUser()
+	serverModeUid := b.pm.CurrentUserID()
 	if serverModeUid == "" {
 		// Either this platform isn't a "multi-user" platform or we're not yet
 		// running as one.
@@ -2053,11 +2053,21 @@ func (b *LocalBackend) CheckIPNConnectionAllowed(ci *ipnauth.ConnIdentity) error
 		return errors.New("empty user uid in connection identity")
 	}
 	if uid != serverModeUid {
-		return fmt.Errorf("Tailscale running in server mode (uid=%v); connection from %q not allowed", serverModeUid, uid)
+		return fmt.Errorf("Tailscale running in server mode (%q); connection from %q not allowed", b.tryLookupUserName(serverModeUid), b.tryLookupUserName(uid))
 	}
 	return nil
 }
 
+// tryLookupUserName tries to look up the username for the uid.
+// It returns the username on success, or the UID on failure.
+func (b *LocalBackend) tryLookupUserName(uid string) string {
+	u, err := ipnauth.LookupUserFromID(b.logf, uid)
+	if err != nil {
+		return uid
+	}
+	return u.Username
+}
+
 // Login implements Backend.
 // As of 2022-11-15, this is only exists for Android.
 func (b *LocalBackend) Login(token *tailcfg.Oauth2Token) {
@@ -2221,11 +2231,11 @@ func (b *LocalBackend) shouldUploadServices() bool {
 // On non-multi-user systems, the uid should be set to empty string.
 func (b *LocalBackend) SetCurrentUserID(uid string) {
 	b.mu.Lock()
-	if b.pm.CurrentUser() == uid {
+	if b.pm.CurrentUserID() == uid {
 		b.mu.Unlock()
 		return
 	}
-	if err := b.pm.SetCurrentUser(uid); err != nil {
+	if err := b.pm.SetCurrentUserID(uid); err != nil {
 		b.mu.Unlock()
 		return
 	}

ipn/ipnlocal/profiles.go

@@ -40,15 +40,15 @@ type profileManager struct {
 	isNewProfile bool
 }
 
-// CurrentUser returns the current user ID. It is only non-empty on
+// CurrentUserID returns the current user ID. It is only non-empty on
 // Windows where we have a multi-user system.
-func (pm *profileManager) CurrentUser() string {
+func (pm *profileManager) CurrentUserID() string {
 	return pm.currentUserID
 }
 
-// SetCurrentUser sets the current user ID. The uid is only non-empty
+// SetCurrentUserID sets the current user ID. The uid is only non-empty
 // on Windows where we have a multi-user system.
-func (pm *profileManager) SetCurrentUser(uid string) error {
+func (pm *profileManager) SetCurrentUserID(uid string) error {
 	if pm.currentUserID == uid {
 		return nil
 	}

ipn/ipnlocal/profiles_test.go

@@ -44,7 +44,7 @@ func TestProfileCurrentUserSwitch(t *testing.T) {
 		return p.View()
 	}
 
-	pm.SetCurrentUser("user1")
+	pm.SetCurrentUserID("user1")
 	newProfile(t, "user1")
 	cp := pm.currentProfile
 	pm.DeleteProfile(cp.ID)
@@ -61,7 +61,7 @@ func TestProfileCurrentUserSwitch(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	pm.SetCurrentUser("user1")
+	pm.SetCurrentUserID("user1")
 	if pm.currentProfile == nil {
 		t.Fatal("currentProfile is nil")
 	} else if pm.currentProfile.ID != "" {
@@ -112,18 +112,18 @@ func TestProfileList(t *testing.T) {
 		}
 	}
 
-	pm.SetCurrentUser("user1")
+	pm.SetCurrentUserID("user1")
 	newProfile(t, "alice")
 	newProfile(t, "bob")
 	checkProfiles(t, "alice", "bob")
 
-	pm.SetCurrentUser("user2")
+	pm.SetCurrentUserID("user2")
 	checkProfiles(t)
 	newProfile(t, "carol")
 	carol := pm.currentProfile
 	checkProfiles(t, "carol")
 
-	pm.SetCurrentUser("user1")
+	pm.SetCurrentUserID("user1")
 	checkProfiles(t, "alice", "bob")
 	if lp := pm.findProfileByKey(carol.Key); lp != nil {
 		t.Fatalf("found profile for user2 in user1's profile list")
@@ -138,7 +138,7 @@ func TestProfileList(t *testing.T) {
 		t.Fatalf("found profile for user2 in user1's profile list")
 	}
 
-	pm.SetCurrentUser("user2")
+	pm.SetCurrentUserID("user2")
 	checkProfiles(t, "carol")
 }
 
@@ -342,7 +342,7 @@ func TestProfileManagementWindows(t *testing.T) {
 
 	{
 		t.Logf("Set user1 as logged in user")
-		if err := pm.SetCurrentUser("user1"); err != nil {
+		if err := pm.SetCurrentUserID("user1"); err != nil {
 			t.Fatal(err)
 		}
 		checkProfiles(t)
@@ -378,7 +378,7 @@ func TestProfileManagementWindows(t *testing.T) {
 
 	{
 		t.Logf("Set user1 as current user")
-		if err := pm.SetCurrentUser("user1"); err != nil {
+		if err := pm.SetCurrentUserID("user1"); err != nil {
 			t.Fatal(err)
 		}
 		wantCurProfile = "test"
@@ -388,8 +388,8 @@ func TestProfileManagementWindows(t *testing.T) {
 		t.Logf("set unattended mode")
 		wantProfiles["test"] = setPrefs(t, "test", true)
 	}
-	if pm.CurrentUser() != "user1" {
+	if pm.CurrentUserID() != "user1" {
-		t.Fatalf("CurrentUserID = %q; want %q", pm.CurrentUser(), "user1")
+		t.Fatalf("CurrentUserID = %q; want %q", pm.CurrentUserID(), "user1")
 	}
 
 	// Recreate the profile manager to ensure that it starts with test profile.
@@ -398,7 +398,7 @@ func TestProfileManagementWindows(t *testing.T) {
 		t.Fatal(err)
 	}
 	checkProfiles(t)
-	if pm.CurrentUser() != "user1" {
+	if pm.CurrentUserID() != "user1" {
-		t.Fatalf("CurrentUserID = %q; want %q", pm.CurrentUser(), "user1")
+		t.Fatalf("CurrentUserID = %q; want %q", pm.CurrentUserID(), "user1")
 	}
 }