fd.o#22970: GibberUnixTransport: make credential-passing support optional and detectable

Our implementation only works for Linux so far, so we need to be able to
avoid advertising credential-passing on e.g. Darwin.

Patches to the implementation were copied from Gabble, fd.o #22968;
patches to the tests are new.

3 files changed, 66 insertions, 3 deletions

diff --git a/lib/gibber/gibber-unix-transport.c b/lib/gibber/gibber-unix-transport.c
index 244f4683..7c800d8c 100644
--- a/lib/gibber/gibber-unix-transport.c
+++ b/lib/gibber/gibber-unix-transport.c
@@ -194,6 +194,17 @@ gibber_unix_transport_new_from_fd (int fd)
   return transport;
 }
 
+/* Patches that reimplement these functions for non-Linux would be welcome
+ * (please file a bug) */
+
+#if defined(__linux__)
+
+gboolean
+gibber_unix_transport_supports_credentials (void)
+{
+  return TRUE;
+}
+
 gboolean
 gibber_unix_transport_send_credentials (GibberUnixTransport *transport,
     const guint8 *data,
@@ -356,3 +367,39 @@ gibber_unix_transport_recv_credentials (GibberUnixTransport *self,
   priv->recv_creds_data = user_data;
   return TRUE;
 }
+
+#else /* OSs where we have no implementation */
+
+gboolean
+gibber_unix_transport_supports_credentials (void)
+{
+  return FALSE;
+}
+
+gboolean
+gibber_unix_transport_recv_credentials (GibberUnixTransport *self,
+    GibberUnixTransportRecvCredentialsCb callback,
+    gpointer user_data)
+{
+  DEBUG ("stub implementation, failing");
+  return FALSE;
+}
+
+gboolean
+gibber_unix_transport_send_credentials (GibberUnixTransport *transport,
+    const guint8 *data,
+    gsize size)
+{
+  DEBUG ("stub implementation, failing");
+  return FALSE;
+}
+
+static GibberFdIOResult
+gibber_unix_transport_read (GibberFdTransport *transport,
+    GIOChannel *channel,
+    GError **error)
+{
+  return gibber_fd_transport_read (transport, channel, error);
+}
+
+#endif
diff --git a/lib/gibber/gibber-unix-transport.h b/lib/gibber/gibber-unix-transport.h
index b89a0dd5..3aad8d47 100644
--- a/lib/gibber/gibber-unix-transport.h
+++ b/lib/gibber/gibber-unix-transport.h
@@ -79,6 +79,8 @@ GType gibber_unix_transport_get_type (void);
   (G_TYPE_INSTANCE_GET_CLASS ((obj), GIBBER_TYPE_UNIX_TRANSPORT, \
    GibberUnixTransportClass))
 
+gboolean gibber_unix_transport_supports_credentials (void);
+
 GibberUnixTransport * gibber_unix_transport_new (void);
 
 GibberUnixTransport * gibber_unix_transport_new_from_fd (int fd);
diff --git a/lib/gibber/tests/check-gibber-unix-transport.c b/lib/gibber/tests/check-gibber-unix-transport.c
index 409b6e4b..6a048fef 100644
--- a/lib/gibber/tests/check-gibber-unix-transport.c
+++ b/lib/gibber/tests/check-gibber-unix-transport.c
@@ -50,6 +50,7 @@ new_connection_cb (GibberListener *listener,
                    guint size,
                    GMainLoop *loop)
 {
+#if defined(__linux__)
   int fd, opt, ret;
   struct iovec iov;
   struct msghdr msg;
@@ -58,12 +59,14 @@ new_connection_cb (GibberListener *listener,
   struct cmsghdr *ch;
   struct ucred *cred;
   gchar buffer[128];
+#endif
 
   got_connection = TRUE;
 
   /* Block receiving so the data won't be consummed by transport's GIOSource */
   gibber_transport_block_receiving (connection, TRUE);
 
+#if defined(__linux__)
   g_assert (gibber_unix_transport_send_credentials (unix_transport,
         (guint8 *) DATA, strlen (DATA) + 1));
 
@@ -96,6 +99,10 @@ new_connection_cb (GibberListener *listener,
   g_assert (cred->pid == getpid ());
   g_assert (cred->uid == getuid ());
   g_assert (cred->gid == getgid ());
+#else /* not Linux */
+  g_assert (!gibber_unix_transport_send_credentials (unix_transport,
+        (guint8 *) DATA, strlen (DATA) + 1));
+#endif
 
   g_main_loop_quit (loop);
 }
@@ -137,7 +144,6 @@ START_TEST (test_send_credentials)
   g_main_loop_unref (mainloop);
 } END_TEST
 
-
 static void
 get_credentials_cb (GibberUnixTransport *transport,
                     GibberBuffer *buffer,
@@ -165,11 +171,17 @@ receive_new_connection_cb (GibberListener *listener,
                            guint size,
                            GMainLoop *loop)
 {
-  gibber_unix_transport_recv_credentials (unix_transport,
+  gboolean ok;
+
+  ok = gibber_unix_transport_recv_credentials (unix_transport,
       get_credentials_cb, loop);
 
-  gibber_unix_transport_send_credentials (GIBBER_UNIX_TRANSPORT (connection),
+  g_assert (ok == gibber_unix_transport_supports_credentials ());
+
+  ok = gibber_unix_transport_send_credentials (GIBBER_UNIX_TRANSPORT (connection),
       (guint8 *) DATA, strlen (DATA));
+
+  g_assert (ok == gibber_unix_transport_supports_credentials ());
 }
 
 START_TEST (test_receive_credentials)
@@ -199,10 +211,12 @@ START_TEST (test_receive_credentials)
   ret = gibber_unix_transport_connect (unix_transport, path, &error);
   fail_if (ret != TRUE);
 
+#if defined(__linux__)
   if (!received_credentials)
     g_main_loop_run (mainloop);
 
   fail_if (!received_credentials, "Failed to receive credentials");
+#endif
 
   g_object_unref (listener_unix);
   g_object_unref (unix_transport);