From 3bbaa148f73a1ab246050781f5ae9be29f267fe3 Mon Sep 17 00:00:00 2001
From: Simon McVittie <smcv@collabora.com>
Date: Fri, 11 May 2018 18:49:48 +0100
Subject: [PATCH 19/39] containers test: Monitor observer name-ownership

We can use this after disconnecting the observer, as a way to work out
when a confined connection that might not be allowed to see the
observer would have seen NameOwnerChanged for the observer if it
was ever going to: if the unconfined connection has seen the observer
disappear, and the confined connection has seen a message that the
unconfined connection only sent after it saw the observer disappear,
then causal ordering means the confined connection would also have
seen NameOwnerChanged (if it was going to).

Signed-off-by: Simon McVittie <smcv@collabora.com>
---
 test/containers.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/test/containers.c b/test/containers.c
index 611a0dc6..495a9e88 100644
--- a/test/containers.c
+++ b/test/containers.c
@@ -46,6 +46,13 @@
 
 #include "test-utils-glib.h"
 
+typedef enum
+{
+  NAME_TRISTATE_MAYBE_OWNED = '?',
+  NAME_TRISTATE_OWNED = '+',
+  NAME_TRISTATE_NOT_OWNED = '-'
+} NameTristate;
+
 typedef struct {
     TestMainContext *ctx;
     gboolean skip;
@@ -65,10 +72,18 @@ typedef struct {
 
     GDBusConnection *observer_conn;
     GDBusProxy *observer_proxy;
+    gchar *observer_unique_name;
     GHashTable *containers_removed;
     guint removed_sub;
     DBusConnection *libdbus_observer;
     DBusMessage *latest_shout;
+
+    /* These watch the observer, from the perspective of the unconfined
+     * connection. */
+    NameTristate observer_unique_name_owned;
+    NameTristate observer_well_known_name_owned;
+    guint observer_unique_name_watch;
+    guint observer_well_known_name_watch;
 } Fixture;
 
 typedef struct
@@ -160,6 +175,18 @@ instance_removed_cb (GDBusConnection *observer,
 static void
 fixture_disconnect_unconfined (Fixture *f)
 {
+  if (f->observer_unique_name_watch != 0)
+    {
+      g_bus_unwatch_name (f->observer_unique_name_watch);
+      f->observer_unique_name_watch = 0;
+    }
+
+  if (f->observer_well_known_name_watch != 0)
+    {
+      g_bus_unwatch_name (f->observer_well_known_name_watch);
+      f->observer_well_known_name_watch = 0;
+    }
+
   if (f->unconfined_conn != NULL)
     {
       GError *error = NULL;
@@ -238,6 +265,33 @@ fixture_disconnect_confined (Fixture *f,
   g_clear_object (&f->confined_conns[i]);
 }
 
+static void
+observer_appeared_cb (GDBusConnection *connection,
+                      const gchar *name,
+                      const gchar *name_owner,
+                      gpointer user_data)
+{
+  NameTristate *tristate = user_data;
+
+  g_test_message ("Unconfined connection saw unconfined observer "
+                  "connection \"%s\" appear, owned by \"%s\"",
+                  name, name_owner);
+  *tristate = NAME_TRISTATE_OWNED;
+}
+
+static void
+observer_vanished_cb (GDBusConnection *connection,
+                      const gchar *name,
+                      gpointer user_data)
+{
+  NameTristate *tristate = user_data;
+
+  g_test_message ("Unconfined connection saw unconfined observer "
+                  "connection \"%s\" disappear",
+                  name);
+  *tristate = NAME_TRISTATE_NOT_OWNED;
+}
+
 static void
 setup (Fixture *f,
        gconstpointer context)
@@ -273,6 +327,11 @@ setup (Fixture *f,
        G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT),
       NULL, NULL, &f->error);
   g_assert_no_error (f->error);
+  f->observer_unique_name = g_strdup (
+      g_dbus_connection_get_unique_name (f->observer_conn));
+  g_test_message ("Unconfined observer connection: \"%s\"",
+                  f->observer_unique_name);
+
   f->containers_removed = g_hash_table_new_full (g_str_hash, g_str_equal,
                                                  g_free, NULL);
   f->removed_sub = g_dbus_connection_signal_subscribe (f->observer_conn,
@@ -293,6 +352,21 @@ setup (Fixture *f,
   if (!dbus_connection_add_filter (f->libdbus_observer, observe_shouting_cb, f,
                                    NULL))
     g_error ("OOM");
+
+  f->observer_unique_name_owned = NAME_TRISTATE_MAYBE_OWNED;
+  f->observer_unique_name_watch = g_bus_watch_name_on_connection (
+      f->unconfined_conn, f->observer_unique_name,
+      G_BUS_NAME_WATCHER_FLAGS_NONE,
+      observer_appeared_cb, observer_vanished_cb,
+      &f->observer_unique_name_owned,
+      NULL);
+  f->observer_well_known_name_owned = NAME_TRISTATE_MAYBE_OWNED;
+  f->observer_well_known_name_watch = g_bus_watch_name_on_connection (
+      f->unconfined_conn, "com.example.Observer",
+      G_BUS_NAME_WATCHER_FLAGS_NONE,
+      observer_appeared_cb, observer_vanished_cb,
+      &f->observer_well_known_name_owned,
+      NULL);
 }
 
 /*
-- 
2.17.0