core: make sure objects retrieved with g_object_get() are valid in the ifaces

The interfaces usually retrieve objects (e.g. skeletons) from the Modem object
using g_object_get(), but we didn't make sure that these objects were actually
valid before using them.

This should clean up errors happening when the modem gets unplugged and still
some actions are ongoing.

Should fix https://bugzilla.gnome.org/show_bug.cgi?id=685933

1 files changed, 64 insertions, 90 deletions

diff --git a/src/mm-iface-modem-cdma.c b/src/mm-iface-modem-cdma.c
index ab4ea4ce..8478df52 100644
--- a/src/mm-iface-modem-cdma.c
+++ b/src/mm-iface-modem-cdma.c
@@ -45,6 +45,8 @@ mm_iface_modem_cdma_bind_simple_status (MMIfaceModemCdma *self,
     g_object_get (self,
                   MM_IFACE_MODEM_CDMA_DBUS_SKELETON, &skeleton,
                   NULL);
+    if (!skeleton)
+        return;
 
     g_object_bind_property (skeleton, "cdma1x-registration-state",
                             status, MM_SIMPLE_PROPERTY_CDMA_CDMA1X_REGISTRATION_STATE,
@@ -1189,35 +1191,14 @@ struct _DisablingContext {
     MmGdbusModemCdma *skeleton;
 };
 
-static DisablingContext *
-disabling_context_new (MMIfaceModemCdma *self,
-                       GAsyncReadyCallback callback,
-                       gpointer user_data)
-{
-    DisablingContext *ctx;
-
-    ctx = g_new0 (DisablingContext, 1);
-    ctx->self = g_object_ref (self);
-    ctx->result = g_simple_async_result_new (G_OBJECT (self),
-                                             callback,
-                                             user_data,
-                                             disabling_context_new);
-    ctx->step = DISABLING_STEP_FIRST;
-    g_object_get (ctx->self,
-                  MM_IFACE_MODEM_CDMA_DBUS_SKELETON, &ctx->skeleton,
-                  NULL);
-    g_assert (ctx->skeleton != NULL);
-
-    return ctx;
-}
-
 static void
 disabling_context_complete_and_free (DisablingContext *ctx)
 {
     g_simple_async_result_complete_in_idle (ctx->result);
     g_object_unref (ctx->self);
     g_object_unref (ctx->result);
-    g_object_unref (ctx->skeleton);
+    if (ctx->skeleton)
+        g_object_unref (ctx->skeleton);
     g_free (ctx);
 }
 
@@ -1317,9 +1298,28 @@ mm_iface_modem_cdma_disable (MMIfaceModemCdma *self,
                              GAsyncReadyCallback callback,
                              gpointer user_data)
 {
-    interface_disabling_step (disabling_context_new (self,
-                                                     callback,
-                                                     user_data));
+    DisablingContext *ctx;
+
+    ctx = g_new0 (DisablingContext, 1);
+    ctx->self = g_object_ref (self);
+    ctx->result = g_simple_async_result_new (G_OBJECT (self),
+                                             callback,
+                                             user_data,
+                                             mm_iface_modem_cdma_disable);
+    ctx->step = DISABLING_STEP_FIRST;
+    g_object_get (ctx->self,
+                  MM_IFACE_MODEM_CDMA_DBUS_SKELETON, &ctx->skeleton,
+                  NULL);
+    if (!ctx->skeleton) {
+        g_simple_async_result_set_error (ctx->result,
+                                         MM_CORE_ERROR,
+                                         MM_CORE_ERROR_FAILED,
+                                         "Couldn't get interface skeleton");
+        disabling_context_complete_and_free (ctx);
+        return;
+    }
+
+    interface_disabling_step (ctx);
 }
 
 /*****************************************************************************/
@@ -1344,30 +1344,6 @@ struct _EnablingContext {
     MmGdbusModemCdma *skeleton;
 };
 
-static EnablingContext *
-enabling_context_new (MMIfaceModemCdma *self,
-                      GCancellable *cancellable,
-                      GAsyncReadyCallback callback,
-                      gpointer user_data)
-{
-    EnablingContext *ctx;
-
-    ctx = g_new0 (EnablingContext, 1);
-    ctx->self = g_object_ref (self);
-    ctx->cancellable = g_object_ref (cancellable);
-    ctx->result = g_simple_async_result_new (G_OBJECT (self),
-                                             callback,
-                                             user_data,
-                                             enabling_context_new);
-    ctx->step = ENABLING_STEP_FIRST;
-    g_object_get (ctx->self,
-                  MM_IFACE_MODEM_CDMA_DBUS_SKELETON, &ctx->skeleton,
-                  NULL);
-    g_assert (ctx->skeleton != NULL);
-
-    return ctx;
-}
-
 static void
 enabling_context_complete_and_free (EnablingContext *ctx)
 {
@@ -1375,7 +1351,8 @@ enabling_context_complete_and_free (EnablingContext *ctx)
     g_object_unref (ctx->self);
     g_object_unref (ctx->result);
     g_object_unref (ctx->cancellable);
-    g_object_unref (ctx->skeleton);
+    if (ctx->skeleton)
+        g_object_unref (ctx->skeleton);
     g_free (ctx);
 }
 
@@ -1520,10 +1497,29 @@ mm_iface_modem_cdma_enable (MMIfaceModemCdma *self,
                             GAsyncReadyCallback callback,
                             gpointer user_data)
 {
-    interface_enabling_step (enabling_context_new (self,
-                                                   cancellable,
-                                                   callback,
-                                                   user_data));
+    EnablingContext *ctx;
+
+    ctx = g_new0 (EnablingContext, 1);
+    ctx->self = g_object_ref (self);
+    ctx->cancellable = g_object_ref (cancellable);
+    ctx->result = g_simple_async_result_new (G_OBJECT (self),
+                                             callback,
+                                             user_data,
+                                             mm_iface_modem_cdma_enable);
+    ctx->step = ENABLING_STEP_FIRST;
+    g_object_get (ctx->self,
+                  MM_IFACE_MODEM_CDMA_DBUS_SKELETON, &ctx->skeleton,
+                  NULL);
+    if (!ctx->skeleton) {
+        g_simple_async_result_set_error (ctx->result,
+                                         MM_CORE_ERROR,
+                                         MM_CORE_ERROR_FAILED,
+                                         "Couldn't get interface skeleton");
+        enabling_context_complete_and_free (ctx);
+        return;
+    }
+
+    interface_enabling_step (ctx);
 }
 
 /*****************************************************************************/
@@ -1546,29 +1542,6 @@ struct _InitializationContext {
     InitializationStep step;
 };
 
-static InitializationContext *
-initialization_context_new (MMIfaceModemCdma *self,
-                            GCancellable *cancellable,
-                            GAsyncReadyCallback callback,
-                            gpointer user_data)
-{
-    InitializationContext *ctx;
-
-    ctx = g_new0 (InitializationContext, 1);
-    ctx->self = g_object_ref (self);
-    ctx->cancellable = g_object_ref (cancellable);
-    ctx->result = g_simple_async_result_new (G_OBJECT (self),
-                                             callback,
-                                             user_data,
-                                             initialization_context_new);
-    ctx->step = INITIALIZATION_STEP_FIRST;
-    g_object_get (ctx->self,
-                  MM_IFACE_MODEM_CDMA_DBUS_SKELETON, &ctx->skeleton,
-                  NULL);
-    g_assert (ctx->skeleton != NULL);
-    return ctx;
-}
-
 static void
 initialization_context_complete_and_free (InitializationContext *ctx)
 {
@@ -1695,9 +1668,6 @@ mm_iface_modem_cdma_initialize_finish (MMIfaceModemCdma *self,
                                        GAsyncResult *res,
                                        GError **error)
 {
-    g_return_val_if_fail (MM_IS_IFACE_MODEM_CDMA (self), FALSE);
-    g_return_val_if_fail (G_IS_ASYNC_RESULT (res), FALSE);
-
     return !g_simple_async_result_propagate_error (G_SIMPLE_ASYNC_RESULT (res), error);
 }
 
@@ -1707,10 +1677,9 @@ mm_iface_modem_cdma_initialize (MMIfaceModemCdma *self,
                                 GAsyncReadyCallback callback,
                                 gpointer user_data)
 {
+    InitializationContext *ctx;
     MmGdbusModemCdma *skeleton = NULL;
 
-    g_return_if_fail (MM_IS_IFACE_MODEM_CDMA (self));
-
     /* Did we already create it? */
     g_object_get (self,
                   MM_IFACE_MODEM_CDMA_DBUS_SKELETON, &skeleton,
@@ -1738,18 +1707,23 @@ mm_iface_modem_cdma_initialize (MMIfaceModemCdma *self,
     }
 
     /* Perform async initialization here */
-    interface_initialization_step (initialization_context_new (self,
-                                                               cancellable,
-                                                               callback,
-                                                               user_data));
-    g_object_unref (skeleton);
+
+    ctx = g_new0 (InitializationContext, 1);
+    ctx->self = g_object_ref (self);
+    ctx->cancellable = g_object_ref (cancellable);
+    ctx->result = g_simple_async_result_new (G_OBJECT (self),
+                                             callback,
+                                             user_data,
+                                             mm_iface_modem_cdma_initialize);
+    ctx->step = INITIALIZATION_STEP_FIRST;
+    ctx->skeleton = skeleton;
+
+    interface_initialization_step (ctx);
 }
 
 void
 mm_iface_modem_cdma_shutdown (MMIfaceModemCdma *self)
 {
-    g_return_if_fail (MM_IS_IFACE_MODEM_CDMA (self));
-
     /* Remove RegistrationCheckContext object to make sure any pending
      * invocation of periodic_registration_check is cancelled before the
      * DBus skeleton is removed. */