SPEC-3723: restructure meta-agl

Goal is to reach a minimal meta-agl-core as base for IVI and IC work at the same time.
Trim dependencies and move most 'demo' related recipes to meta-agl-demo.

v2: changed to bbapend + .inc , added description
v3: testbuild of all images
v4: restore -test packagegroup and -qa images, compare manifests and adapt packagegroups.
v5: rebased
v6: merged meta-agl-distro into meta-agl-core,
    due to dependency on meta-oe, moved -test packagegroup and -qa images
      to own layer meta-agl-core-test
v7: Fixed comments from Paul Barker
v8: Update the markdown files
v9: restore wayland/weston/agl-compositor recipes/appends, reworked to
    move app f/w specific changes to bbappends in meta-app-framework and
    only demo specific weston-init changes to meta-agl-demo
v10: fix s/agldemo/aglcore/ missed in weston-init.bbappend

Description:

This patch is part 1 out of 2 large patches that implement the layer rework
discussed during the previous workshop. Essentially meta-agl-core is the
small but versatile new core layer of AGL serving as basis for
the work done by the IC and IVI EGs.
All demo related work is moved to meta-agl-demo in the 2nd patchset.
This should be applied together as atomic change.

The resulting meta-agl/* follows these guidelines:
- only bsp adaptations in meta-agl-bsp
- remove the agl-profile-* layers for simplicity
-- the packagegroup-agl(-profile)-graphical and so on
   have been kept in meta-agl-demo
- meta-agl-profile-core is now meta-agl-core
- meta-agl-core does pass yocto-check-layer
-- therefore use the bbappend + conditional + .inc file
   construct found in meta-virtualization
- meta-agl/meta-security has been merged into meta-agl/meta-app-framework
- meta-netboot does pass yocto-check-layer
- meta-pipewire does pass yocto-check-layer

Migration:
All packagegroups are preserved but they're now enabled by 'agl-demo'.

Bug-AGL: SPEC-3723

Signed-off-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>
Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Change-Id: Ia6c6e5e6ce2b4ffa69ea94959cdc57c310ba7c53
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl/+/25769

1 files changed, 967 insertions, 0 deletions

diff --git a/meta-app-framework/recipes-core/dbus-cynagora/dbus-cynagora/0002-Disable-message-dispatching-when-send-rule-result-is.patch b/meta-app-framework/recipes-core/dbus-cynagora/dbus-cynagora/0002-Disable-message-dispatching-when-send-rule-result-is.patch
new file mode 100644
index 000000000..bac8cf97f
--- /dev/null
+++ b/meta-app-framework/recipes-core/dbus-cynagora/dbus-cynagora/0002-Disable-message-dispatching-when-send-rule-result-is.patch
@@ -0,0 +1,967 @@
+From c2f4ba585c777b731df6b6b8a165b6cc4dc5d639 Mon Sep 17 00:00:00 2001
+From: Jacek Bukarewicz <j.bukarewicz@samsung.com>
+Date: Fri, 28 Nov 2014 12:07:39 +0100
+Subject: [PATCH 2/8] Disable message dispatching when send rule result is not
+ known
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+When unicast message is sent to addressed recipient and policy result
+is not available message dispatch from the sender is disabled.
+This also means that any further messages from the given connection are
+put into the incoming queue without being processed. If response is received
+message dispatching is resumed. This time answer is attached to the message
+which is now processed synchronously.
+Receive rule result unavailability is not yet handled - such messages are
+rejected. Also, if message is sent to non-addressed recipient and policy result
+is unknown, message is silently dropped.
+
+Cherry-picked from b1b87ad9f20b2052c28431b48e81073078a745ce
+by Jose Bollo.
+
+Updated for dbus 1.10.20 by Scott Murray and José Bollo
+
+Signed-off-by: José Bollo <jose.bollo@iot.bzh>
+Signed-off-by: Scott Murray <scott.murray@konsulko.com>
+---
+ bus/activation.c                |  76 +++++++++++--
+ bus/check.c                     | 109 +++++++++++++++++--
+ bus/check.h                     |  10 ++
+ bus/cynara.c                    |   1 -
+ bus/dispatch.c                  | 184 ++++++++++++++++++++++++++++----
+ bus/dispatch.h                  |   2 +-
+ bus/driver.c                    |  12 ++-
+ dbus/dbus-connection-internal.h |  15 +++
+ dbus/dbus-connection.c          | 125 +++++++++++++++++++++-
+ dbus/dbus-list.c                |  29 +++++
+ dbus/dbus-list.h                |   3 +
+ dbus/dbus-shared.h              |   3 +-
+ 12 files changed, 528 insertions(+), 41 deletions(-)
+
+diff --git a/bus/activation.c b/bus/activation.c
+index f9c6c62..8301b59 100644
+--- a/bus/activation.c
++++ b/bus/activation.c
+@@ -32,6 +32,7 @@
+ #include "services.h"
+ #include "test.h"
+ #include "utils.h"
++#include <dbus/dbus-connection-internal.h>
+ #include <dbus/dbus-internals.h>
+ #include <dbus/dbus-hash.h>
+ #include <dbus/dbus-list.h>
+@@ -94,6 +95,8 @@ struct BusPendingActivationEntry
+   DBusConnection *connection;
+ 
+   dbus_bool_t auto_activation;
++
++  dbus_bool_t is_put_back;
+ };
+ 
+ typedef struct
+@@ -1241,20 +1244,23 @@ bus_activation_send_pending_auto_activation_messages (BusActivation  *activation
+       BusPendingActivationEntry *entry = link->data;
+       DBusList *next = _dbus_list_get_next_link (&pending_activation->entries, link);
+ 
+-      if (entry->auto_activation && (entry->connection == NULL || dbus_connection_get_is_connected (entry->connection)))
++      if (entry->auto_activation && !entry->is_put_back &&
++          (entry->connection == NULL || dbus_connection_get_is_connected (entry->connection)))
+         {
+           DBusConnection *addressed_recipient;
+           DBusError error;
++          BusResult res;
+ 
+           dbus_error_init (&error);
+ 
+           addressed_recipient = bus_service_get_primary_owners_connection (service);
+ 
+           /* Resume dispatching where we left off in bus_dispatch() */
+-          if (!bus_dispatch_matches (transaction,
+-                                     entry->connection,
+-                                     addressed_recipient,
+-                                     entry->activation_message, &error))
++          res = bus_dispatch_matches (transaction,
++                                      entry->connection,
++                                      addressed_recipient,
++                                      entry->activation_message, &error);
++          if (res == BUS_RESULT_FALSE)
+             {
+               /* If permission is denied, we just want to return the error
+                * to the original method invoker; in particular, we don't
+@@ -1266,11 +1272,44 @@ bus_activation_send_pending_auto_activation_messages (BusActivation  *activation
+                   bus_connection_send_oom_error (entry->connection,
+                                                  entry->activation_message);
+                 }
+-
+               dbus_error_free (&error);
+               link = next;
+               continue;
+             }
++          else if (res == BUS_RESULT_LATER)
++            {
++              DBusList *putback_message_link = link;
++              DBusMessage *last_inserted_message = NULL;
++
++              /* NULL entry->connection implies sending pending ActivationRequest message to systemd */
++              if (entry->connection == NULL)
++                {
++                  _dbus_assert_not_reached ("bus_dispatch_matches returned BUS_RESULT_LATER unexpectedly when sender is NULL");
++                  link = next;
++                  continue;
++                }
++
++              /**
++               * Getting here means that policy check result is not yet available and dispatching
++               * messages from entry->connection has been disabled.
++               * Let's put back all messages for the given connection in the incoming queue and mark
++               * this entry as put back so they are not handled twice.
++               */
++              while (putback_message_link != NULL)
++                {
++                  BusPendingActivationEntry *putback_message = putback_message_link->data;
++                  if (putback_message->connection == entry->connection)
++                    {
++                      if (!_dbus_connection_putback_message (putback_message->connection, last_inserted_message,
++                            putback_message->activation_message, &error))
++                        goto error;
++                      last_inserted_message = putback_message->activation_message;
++                      putback_message->is_put_back = TRUE;
++                    }
++
++                  putback_message_link = _dbus_list_get_next_link(&pending_activation->entries, putback_message_link);
++                }
++            }
+         }
+ 
+       link = next;
+@@ -1287,6 +1326,19 @@ bus_activation_send_pending_auto_activation_messages (BusActivation  *activation
+   return TRUE;
+ 
+  error:
++  /* remove all messages that have been put to connections' incoming queues */
++  link = _dbus_list_get_first_link (&pending_activation->entries);
++  while (link != NULL)
++    {
++      BusPendingActivationEntry *entry = link->data;
++      if (entry->is_put_back)
++        {
++          _dbus_connection_remove_message(entry->connection, entry->activation_message);
++          entry->is_put_back = FALSE;
++        }
++      link = _dbus_list_get_next_link(&pending_activation->entries, link);
++    }
++
+   return FALSE;
+ }
+ 
+@@ -2079,6 +2131,7 @@ bus_activation_activate_service (BusActivation  *activation,
+ 
+           if (service != NULL)
+             {
++              BusResult res;
+               bus_context_log (activation->context,
+                                DBUS_SYSTEM_LOG_INFO, "Activating via systemd: service name='%s' unit='%s' requested by '%s' (%s)",
+                                service_name,
+@@ -2086,8 +2139,17 @@ bus_activation_activate_service (BusActivation  *activation,
+                                bus_connection_get_name (connection),
+                                bus_connection_get_loginfo (connection));
+               /* Wonderful, systemd is connected, let's just send the msg */
+-              retval = bus_dispatch_matches (activation_transaction, NULL,
++              res = bus_dispatch_matches (activation_transaction, NULL,
+                                              systemd, message, error);
++
++              if (res == BUS_RESULT_TRUE)
++                retval = TRUE;
++              else
++                {
++                  retval = FALSE;
++                  if (res == BUS_RESULT_LATER)
++                    _dbus_verbose("Unexpectedly need time to check message from bus driver to systemd - dropping the message.\n");
++                }
+             }
+           else
+             {
+diff --git a/bus/check.c b/bus/check.c
+index 5b72d31..4b8a699 100644
+--- a/bus/check.c
++++ b/bus/check.c
+@@ -55,6 +55,8 @@ typedef struct BusDeferredMessage
+   BusCheckResponseFunc response_callback;
+ } BusDeferredMessage;
+ 
++static dbus_int32_t deferred_message_data_slot = -1;
++
+ BusCheck *
+ bus_check_new (BusContext *context, DBusError *error)
+ {
+@@ -67,11 +69,19 @@ bus_check_new (BusContext *context, DBusError *error)
+       return NULL;
+     }
+ 
++  if (!dbus_message_allocate_data_slot(&deferred_message_data_slot))
++    {
++      dbus_free(check);
++      BUS_SET_OOM(error);
++      return NULL;
++    }
++
+   check->refcount = 1;
+   check->context = context;
+   check->cynara = bus_cynara_new(check, error);
+   if (dbus_error_is_set(error))
+     {
++      dbus_message_free_data_slot(&deferred_message_data_slot);
+       dbus_free(check);
+       return NULL;
+     }
+@@ -98,6 +108,7 @@ bus_check_unref (BusCheck *check)
+   if (check->refcount == 0)
+     {
+       bus_cynara_unref(check->cynara);
++      dbus_message_free_data_slot(&deferred_message_data_slot);
+       dbus_free(check);
+     }
+ }
+@@ -114,6 +125,45 @@ bus_check_get_cynara (BusCheck *check)
+   return check->cynara;
+ }
+ 
++static void
++bus_check_enable_dispatch_callback (BusDeferredMessage *deferred_message,
++                                    BusResult result)
++{
++  _dbus_verbose("bus_check_enable_dispatch_callback called deferred_message=%p\n", deferred_message);
++
++  deferred_message->response = result;
++  _dbus_connection_enable_dispatch(deferred_message->sender);
++}
++
++static void
++deferred_message_free_function(void *data)
++{
++  BusDeferredMessage *deferred_message = (BusDeferredMessage *)data;
++  bus_deferred_message_unref(deferred_message);
++}
++
++void
++bus_deferred_message_disable_sender (BusDeferredMessage *deferred_message)
++{
++  _dbus_assert(deferred_message != NULL);
++  _dbus_assert(deferred_message->sender != NULL);
++
++  if (dbus_message_get_data(deferred_message->message, deferred_message_data_slot) == NULL)
++    {
++      if (dbus_message_set_data(deferred_message->message, deferred_message_data_slot, deferred_message,
++          deferred_message_free_function))
++        bus_deferred_message_ref(deferred_message);
++    }
++
++  _dbus_connection_disable_dispatch(deferred_message->sender);
++  deferred_message->response_callback = bus_check_enable_dispatch_callback;
++}
++
++#ifdef DBUS_ENABLE_EMBEDDED_TESTS
++BusResult (*bus_check_test_override) (DBusConnection *connection,
++                                        const char *privilege);
++#endif
++
+ BusResult
+ bus_check_privilege (BusCheck *check,
+                      DBusMessage *message,
+@@ -124,6 +174,7 @@ bus_check_privilege (BusCheck *check,
+                      BusDeferredMessageStatus check_type,
+                      BusDeferredMessage **deferred_message)
+ {
++  BusDeferredMessage *previous_deferred_message;
+   BusResult result = BUS_RESULT_FALSE;
+ #ifdef DBUS_ENABLE_CYNARA
+   BusCynara *cynara;
+@@ -137,16 +188,54 @@ bus_check_privilege (BusCheck *check,
+       return BUS_RESULT_FALSE;
+     }
+ 
+-  /* ask policy checkers */
+-#ifdef DBUS_ENABLE_CYNARA
+-  cynara = bus_check_get_cynara(check);
+-  result = bus_cynara_check_privilege(cynara, message, sender, addressed_recipient,
+-      proposed_recipient, privilege, check_type, deferred_message);
++#ifdef DBUS_ENABLE_EMBEDDED_TESTS
++  if (bus_check_test_override)
++    return bus_check_test_override (connection, privilege);
+ #endif
+ 
+-  if (result == BUS_RESULT_LATER && deferred_message != NULL)
++  previous_deferred_message = dbus_message_get_data(message, deferred_message_data_slot);
++  /* check if message blocked at sender's queue is being processed */
++  if (previous_deferred_message != NULL)
++    {
++      if ((check_type & BUS_DEFERRED_MESSAGE_CHECK_SEND) &&
++          !(previous_deferred_message->status & BUS_DEFERRED_MESSAGE_CHECK_SEND))
++        {
++          /**
++           * Message has been deferred due to receive or own rule which means that sending this message
++           * is allowed - it must have been checked previously.
++           * This might happen when client calls RequestName method which depending on security
++           * policy might result in both "can_send" and "can_own" Cynara checks.
++           */
++          result = BUS_RESULT_TRUE;
++        }
++      else
++        {
++          result = previous_deferred_message->response;
++          if (result == BUS_RESULT_LATER)
++            {
++              /* result is still not known - reuse deferred message object */
++              if (deferred_message != NULL)
++                *deferred_message = previous_deferred_message;
++            }
++          else
++            {
++              /* result is available - we can remove deferred message from the processed message */
++              dbus_message_set_data(message, deferred_message_data_slot, NULL, NULL);
++            }
++        }
++    }
++  else
+     {
+-      (*deferred_message)->status |= check_type;
++      /* ask policy checkers */
++#ifdef DBUS_ENABLE_CYNARA
++      cynara = bus_check_get_cynara(check);
++      result = bus_cynara_check_privilege(cynara, message, sender, addressed_recipient,
++          proposed_recipient, privilege, check_type, deferred_message);
++#endif
++      if (result == BUS_RESULT_LATER && deferred_message != NULL)
++        {
++          (*deferred_message)->status |= check_type;
++        }
+     }
+   return result;
+ }
+@@ -206,6 +295,12 @@ bus_deferred_message_unref (BusDeferredMessage *deferred_message)
+      }
+ }
+ 
++BusDeferredMessageStatus
++bus_deferred_message_get_status (BusDeferredMessage *deferred_message)
++{
++  return deferred_message->status;
++}
++
+ void
+ bus_deferred_message_response_received (BusDeferredMessage *deferred_message,
+                                         BusResult result)
+diff --git a/bus/check.h b/bus/check.h
+index c3fcaf9..d177549 100644
+--- a/bus/check.h
++++ b/bus/check.h
+@@ -55,6 +55,7 @@ BusResult   bus_check_privilege   (BusCheck *check,
+                                    BusDeferredMessageStatus check_type,
+                                    BusDeferredMessage **deferred_message);
+ 
++
+ BusDeferredMessage *bus_deferred_message_new                (DBusMessage *message,
+                                                              DBusConnection *sender,
+                                                              DBusConnection *addressed_recipient,
+@@ -65,4 +66,13 @@ BusDeferredMessage *bus_deferred_message_ref                (BusDeferredMessage
+ void                bus_deferred_message_unref              (BusDeferredMessage *deferred_message);
+ void                bus_deferred_message_response_received  (BusDeferredMessage *deferred_message,
+                                                              BusResult result);
++void                bus_deferred_message_disable_sender     (BusDeferredMessage *deferred_message);
++
++BusDeferredMessageStatus  bus_deferred_message_get_status   (BusDeferredMessage *deferred_message);
++
++#ifdef DBUS_ENABLE_EMBEDDED_TESTS
++extern BusResult (*bus_check_test_override) (DBusConnection *connection,
++                                               const char *privilege);
++#endif
++
+ #endif /* BUS_CHECK_H */
+diff --git a/bus/cynara.c b/bus/cynara.c
+index 57a4c45..77aed62 100644
+--- a/bus/cynara.c
++++ b/bus/cynara.c
+@@ -36,7 +36,6 @@
+ #include <cynara-client-async.h>
+ #endif
+ 
+-
+ #ifdef DBUS_ENABLE_CYNARA
+ typedef struct BusCynara
+ {
+diff --git a/bus/dispatch.c b/bus/dispatch.c
+index d3867f7..50a22a3 100644
+--- a/bus/dispatch.c
++++ b/bus/dispatch.c
+@@ -35,6 +35,7 @@
+ #include "signals.h"
+ #include "test.h"
+ #include <dbus/dbus-internals.h>
++#include <dbus/dbus-connection-internal.h>
+ #include <dbus/dbus-misc.h>
+ #include <string.h>
+ 
+@@ -122,7 +123,7 @@ send_one_message (DBusConnection *connection,
+   return TRUE;
+ }
+ 
+-dbus_bool_t
++BusResult
+ bus_dispatch_matches (BusTransaction *transaction,
+                       DBusConnection *sender,
+                       DBusConnection *addressed_recipient,
+@@ -158,13 +159,29 @@ bus_dispatch_matches (BusTransaction *transaction,
+                                                message, NULL, error,
+                                                &deferred_message);
+       if (res == BUS_RESULT_FALSE)
+-        return FALSE;
++        return BUS_RESULT_FALSE;
+       else if (res == BUS_RESULT_LATER)
+         {
+-          dbus_set_error (error,
+-                          DBUS_ERROR_ACCESS_DENIED,
+-                          "Rejecting message because time is needed to check security policy");
+-          return FALSE;
++          BusDeferredMessageStatus status;
++          status = bus_deferred_message_get_status(deferred_message);
++
++          if (status & BUS_DEFERRED_MESSAGE_CHECK_SEND)
++            {
++              /* send rule result not available - disable dispatching messages from the sender */
++              bus_deferred_message_disable_sender(deferred_message);
++              return BUS_RESULT_LATER;
++            }
++          else if (status & BUS_DEFERRED_MESSAGE_CHECK_RECEIVE)
++            {
++              dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
++                              "Rejecting message because time is needed to check security policy");
++              return BUS_RESULT_FALSE;
++            }
++          else
++            {
++              _dbus_verbose("deferred message has no status field set to send or receive unexpectedly\n");
++              return BUS_RESULT_FALSE;
++            }
+         }
+ 
+       if (dbus_message_contains_unix_fds (message) &&
+@@ -175,14 +192,14 @@ bus_dispatch_matches (BusTransaction *transaction,
+                           DBUS_ERROR_NOT_SUPPORTED,
+                           "Tried to send message with Unix file descriptors"
+                           "to a client that doesn't support that.");
+-          return FALSE;
+-      }
++          return BUS_RESULT_FALSE;
++        }
+ 
+       /* Dispatch the message */
+       if (!bus_transaction_send (transaction, addressed_recipient, message))
+         {
+           BUS_SET_OOM (error);
+-          return FALSE;
++          return BUS_RESULT_FALSE;
+         }
+     }
+ 
+@@ -197,7 +214,7 @@ bus_dispatch_matches (BusTransaction *transaction,
+                                       &recipients))
+     {
+       BUS_SET_OOM (error);
+-      return FALSE;
++      return BUS_RESULT_FALSE;
+     }
+ 
+   link = _dbus_list_get_first_link (&recipients);
+@@ -219,10 +236,10 @@ bus_dispatch_matches (BusTransaction *transaction,
+   if (dbus_error_is_set (&tmp_error))
+     {
+       dbus_move_error (&tmp_error, error);
+-      return FALSE;
++      return BUS_RESULT_FALSE;
+     }
+   else
+-    return TRUE;
++    return BUS_RESULT_TRUE;
+ }
+ 
+ static DBusHandlerResult
+@@ -409,10 +426,12 @@ bus_dispatch (DBusConnection *connection,
+         }
+       else if (res == BUS_RESULT_LATER)
+         {
+-          dbus_set_error (&error,
+-                          DBUS_ERROR_ACCESS_DENIED,
+-                          "Rejecting message because time is needed to check security policy");
+-          _dbus_verbose ("Security policy needs time to check policy. Dropping message\n");
++          /* Disable dispatching messages from the sender,
++           * roll back and dispatch the message once the policy result is available */
++          bus_deferred_message_disable_sender(deferred_message);
++          bus_transaction_cancel_and_free (transaction);
++          transaction = NULL;
++          result = DBUS_HANDLER_RESULT_LATER;
+           goto out;
+         }
+ 
+@@ -514,8 +533,14 @@ bus_dispatch (DBusConnection *connection,
+    * addressed_recipient == NULL), and match it against other connections'
+    * match rules.
+    */
+-  if (!bus_dispatch_matches (transaction, connection, addressed_recipient, message, &error))
+-    goto out;
++  if (BUS_RESULT_LATER == bus_dispatch_matches (transaction, connection, addressed_recipient,
++                                                message, &error))
++    {
++      /* Roll back and dispatch the message once the policy result is available */
++      bus_transaction_cancel_and_free (transaction);
++      transaction = NULL;
++      result = DBUS_HANDLER_RESULT_LATER;
++    }
+ 
+  out:
+   if (dbus_error_is_set (&error))
+@@ -5060,9 +5085,132 @@ bus_dispatch_test_conf_fail (const DBusString *test_data_dir,
+ }
+ #endif
+ 
++typedef struct {
++  DBusTimeout *timeout;
++  DBusConnection *connection;
++  dbus_bool_t timedout;
++  int check_counter;
++} BusTestCheckData;
++
++static BusTestCheckData *cdata;
++
++static dbus_bool_t
++bus_dispatch_test_check_timeout (void *data)
++{
++  _dbus_verbose ("timeout triggered - pretend that privilege check result is available\n");
++
++  /* should only happen once during the test */
++  _dbus_assert (!cdata->timedout);
++  cdata->timedout = TRUE;
++  _dbus_connection_enable_dispatch (cdata->connection);
++
++  /* don't call this again */
++  _dbus_loop_remove_timeout (bus_connection_get_loop (cdata->connection),
++                             cdata->timeout);
++  dbus_connection_unref (cdata->connection);
++  cdata->connection = NULL;
++  return TRUE;
++}
++
++static BusResult
++bus_dispatch_test_check_override (DBusConnection *connection,
++                                  const char *privilege)
++{
++  _dbus_verbose ("overriding privilege check %s #%d\n", privilege, cdata->check_counter);
++  cdata->check_counter++;
++  if (!cdata->timedout)
++    {
++      dbus_bool_t added;
++
++      /* Should be the first privilege check for the "Echo" method. */
++      _dbus_assert (cdata->check_counter == 1);
++      cdata->timeout = _dbus_timeout_new (1, bus_dispatch_test_check_timeout,
++                                          NULL, NULL);
++      _dbus_assert (cdata->timeout);
++      added = _dbus_loop_add_timeout (bus_connection_get_loop (connection),
++                                      cdata->timeout);
++      _dbus_assert (added);
++      cdata->connection = connection;
++      dbus_connection_ref (connection);
++      _dbus_connection_disable_dispatch (connection);
++      return BUS_RESULT_LATER;
++    }
++  else
++    {
++      /* Should only be checked one more time, and this time succeeds. */
++      _dbus_assert (cdata->check_counter == 2);
++      return BUS_RESULT_TRUE;
++    }
++}
++
++static dbus_bool_t
++bus_dispatch_test_check (const DBusString *test_data_dir)
++{
++  const char *filename = "valid-config-files/debug-check-some.conf";
++  BusContext *context;
++  DBusConnection *foo;
++  DBusError error;
++  dbus_bool_t result = TRUE;
++  BusTestCheckData data;
++
++  /* save the config name for the activation helper */
++  if (!setenv_TEST_LAUNCH_HELPER_CONFIG (test_data_dir, filename))
++    _dbus_assert_not_reached ("no memory setting TEST_LAUNCH_HELPER_CONFIG");
++
++  dbus_error_init (&error);
++
++  context = bus_context_new_test (test_data_dir, filename);
++  if (context == NULL)
++    return FALSE;
++
++  foo = dbus_connection_open_private (TEST_DEBUG_PIPE, &error);
++  if (foo == NULL)
++    _dbus_assert_not_reached ("could not alloc connection");
++
++  if (!bus_setup_debug_client (foo))
++    _dbus_assert_not_reached ("could not set up connection");
++
++  spin_connection_until_authenticated (context, foo);
++
++  if (!check_hello_message (context, foo))
++    _dbus_assert_not_reached ("hello message failed");
++
++  if (!check_double_hello_message (context, foo))
++    _dbus_assert_not_reached ("double hello message failed");
++
++  if (!check_add_match (context, foo, ""))
++    _dbus_assert_not_reached ("AddMatch message failed");
++
++  /*
++   * Cause bus_check_send_privilege() to return BUS_RESULT_LATER in the
++   * first call, then BUS_RESULT_TRUE.
++   */
++  cdata = &data;
++  memset (cdata, 0, sizeof(*cdata));
++  bus_check_test_override = bus_dispatch_test_check_override;
++
++  result = check_existent_service_auto_start (context, foo);
++
++  _dbus_assert (cdata->check_counter == 2);
++  _dbus_assert (cdata->timedout);
++  _dbus_assert (cdata->timeout);
++  _dbus_assert (!cdata->connection);
++  _dbus_timeout_unref (cdata->timeout);
++
++  kill_client_connection_unchecked (foo);
++
++  bus_context_unref (context);
++
++  return result;
++}
++
+ dbus_bool_t
+ bus_dispatch_test (const DBusString *test_data_dir)
+ {
++  _dbus_verbose ("<check> tests\n");
++  if (!bus_dispatch_test_check (test_data_dir))
++    return FALSE;
++
+   /* run normal activation tests */
+   _dbus_verbose ("Normal activation tests\n");
+   if (!bus_dispatch_test_conf (test_data_dir,
+diff --git a/bus/dispatch.h b/bus/dispatch.h
+index fb5ba7a..afba6a2 100644
+--- a/bus/dispatch.h
++++ b/bus/dispatch.h
+@@ -29,7 +29,7 @@
+ 
+ dbus_bool_t bus_dispatch_add_connection    (DBusConnection *connection);
+ void        bus_dispatch_remove_connection (DBusConnection *connection);
+-dbus_bool_t bus_dispatch_matches           (BusTransaction *transaction,
++BusResult   bus_dispatch_matches           (BusTransaction *transaction,
+                                             DBusConnection *sender,
+                                             DBusConnection *recipient,
+                                             DBusMessage    *message,
+diff --git a/bus/driver.c b/bus/driver.c
+index cd0a714..f414f64 100644
+--- a/bus/driver.c
++++ b/bus/driver.c
+@@ -218,6 +218,7 @@ bus_driver_send_service_owner_changed (const char     *service_name,
+ {
+   DBusMessage *message;
+   dbus_bool_t retval;
++  BusResult res;
+   const char *null_service;
+ 
+   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
+@@ -253,7 +254,16 @@ bus_driver_send_service_owner_changed (const char     *service_name,
+   if (!bus_transaction_capture (transaction, NULL, NULL, message))
+     goto oom;
+ 
+-  retval = bus_dispatch_matches (transaction, NULL, NULL, message, error);
++  res = bus_dispatch_matches (transaction, NULL, NULL, message, error);
++  if (res == BUS_RESULT_TRUE)
++    retval = TRUE;
++  else
++    {
++      retval = FALSE;
++      if (res == BUS_RESULT_LATER)
++        /* should never happen */
++        _dbus_assert_not_reached ("bus_dispatch_matches returned BUS_RESULT_LATER unexpectedly");
++    }
+   dbus_message_unref (message);
+ 
+   return retval;
+diff --git a/dbus/dbus-connection-internal.h b/dbus/dbus-connection-internal.h
+index 4835732..94b1c95 100644
+--- a/dbus/dbus-connection-internal.h
++++ b/dbus/dbus-connection-internal.h
+@@ -118,6 +118,21 @@ DBUS_PRIVATE_EXPORT
+ dbus_bool_t       _dbus_connection_get_linux_security_label       (DBusConnection  *connection,
+                                                                    char           **label_p);
+ 
++DBUS_PRIVATE_EXPORT
++void              _dbus_connection_enable_dispatch                (DBusConnection *connection);
++DBUS_PRIVATE_EXPORT
++void              _dbus_connection_disable_dispatch               (DBusConnection *connection);
++
++DBUS_PRIVATE_EXPORT
++dbus_bool_t       _dbus_connection_putback_message                (DBusConnection *connection,
++                                                                   DBusMessage    *after_message,
++                                                                   DBusMessage    *message,
++                                                                   DBusError      *error);
++
++DBUS_PRIVATE_EXPORT
++dbus_bool_t       _dbus_connection_remove_message                 (DBusConnection *connection,
++                                                                   DBusMessage    *message);
++
+ /* if DBUS_ENABLE_STATS */
+ DBUS_PRIVATE_EXPORT
+ void _dbus_connection_get_stats (DBusConnection *connection,
+diff --git a/dbus/dbus-connection.c b/dbus/dbus-connection.c
+index c525b6d..958968c 100644
+--- a/dbus/dbus-connection.c
++++ b/dbus/dbus-connection.c
+@@ -311,7 +311,8 @@ struct DBusConnection
+    */
+   dbus_bool_t dispatch_acquired; /**< Someone has dispatch path (can drain incoming queue) */
+   dbus_bool_t io_path_acquired;  /**< Someone has transport io path (can use the transport to read/write messages) */
+-  
++
++  unsigned int dispatch_disabled : 1;  /**< if true, then dispatching incoming messages is stopped until enabled again */
+   unsigned int shareable : 1; /**< #TRUE if libdbus owns a reference to the connection and can return it from dbus_connection_open() more than once */
+   
+   unsigned int exit_on_disconnect : 1; /**< If #TRUE, exit after handling disconnect signal */
+@@ -439,6 +440,39 @@ _dbus_connection_wakeup_mainloop (DBusConnection *connection)
+     (*connection->wakeup_main_function) (connection->wakeup_main_data);
+ }
+ 
++static void
++_dbus_connection_set_dispatch(DBusConnection *connection,
++                              dbus_bool_t disabled)
++{
++  CONNECTION_LOCK (connection);
++  if (connection->dispatch_disabled != disabled)
++    {
++      DBusDispatchStatus status;
++
++      connection->dispatch_disabled = disabled;
++      status = _dbus_connection_get_dispatch_status_unlocked (connection);
++      _dbus_connection_update_dispatch_status_and_unlock (connection, status);
++    }
++  else
++    {
++      CONNECTION_UNLOCK (connection);
++    }
++}
++
++
++void
++_dbus_connection_enable_dispatch (DBusConnection *connection)
++{
++  _dbus_connection_set_dispatch (connection, FALSE);
++}
++
++void
++ _dbus_connection_disable_dispatch (DBusConnection *connection)
++{
++  _dbus_connection_set_dispatch (connection, TRUE);
++}
++
++
+ #ifdef DBUS_ENABLE_EMBEDDED_TESTS
+ /**
+  * Gets the locks so we can examine them
+@@ -4069,6 +4103,82 @@ _dbus_connection_putback_message_link_unlocked (DBusConnection *connection,
+       "_dbus_connection_putback_message_link_unlocked");
+ }
+ 
++dbus_bool_t
++_dbus_connection_putback_message (DBusConnection *connection,
++                                  DBusMessage    *after_message,
++                                  DBusMessage    *message,
++                                  DBusError      *error)
++{
++  DBusDispatchStatus status;
++  DBusList *message_link = _dbus_list_alloc_link (message);
++  DBusList *after_link;
++  if (message_link == NULL)
++    {
++      _DBUS_SET_OOM (error);
++      return FALSE;
++    }
++  dbus_message_ref (message);
++
++  CONNECTION_LOCK (connection);
++  _dbus_connection_acquire_dispatch (connection);
++  HAVE_LOCK_CHECK (connection);
++
++  after_link = _dbus_list_find_first(&connection->incoming_messages, after_message);
++  _dbus_list_insert_after_link (&connection->incoming_messages, after_link, message_link);
++  connection->n_incoming += 1;
++
++  _dbus_verbose ("Message %p (%s %s %s '%s') put back into queue %p, %d incoming\n",
++                 message_link->data,
++                 dbus_message_type_to_string (dbus_message_get_type (message_link->data)),
++                 dbus_message_get_interface (message_link->data) ?
++                 dbus_message_get_interface (message_link->data) :
++                 "no interface",
++                 dbus_message_get_member (message_link->data) ?
++                 dbus_message_get_member (message_link->data) :
++                 "no member",
++                 dbus_message_get_signature (message_link->data),
++                 connection, connection->n_incoming);
++
++  _dbus_message_trace_ref (message_link->data, -1, -1,
++      "_dbus_connection_putback_message");
++
++  _dbus_connection_release_dispatch (connection);
++
++  status = _dbus_connection_get_dispatch_status_unlocked (connection);
++  _dbus_connection_update_dispatch_status_and_unlock (connection, status);
++
++  return TRUE;
++}
++
++dbus_bool_t
++_dbus_connection_remove_message (DBusConnection *connection,
++                                 DBusMessage *message)
++{
++  DBusDispatchStatus status;
++  dbus_bool_t removed;
++
++  CONNECTION_LOCK (connection);
++  _dbus_connection_acquire_dispatch (connection);
++  HAVE_LOCK_CHECK (connection);
++
++  removed = _dbus_list_remove(&connection->incoming_messages, message);
++
++  if (removed)
++    {
++      connection->n_incoming -= 1;
++      dbus_message_unref(message);
++      _dbus_verbose ("Message %p removed from incoming queue\n", message);
++    }
++  else
++      _dbus_verbose ("Message %p not found in the incoming queue\n", message);
++
++  _dbus_connection_release_dispatch (connection);
++
++  status = _dbus_connection_get_dispatch_status_unlocked (connection);
++  _dbus_connection_update_dispatch_status_and_unlock (connection, status);
++  return removed;
++}
++
+ /**
+  * Returns the first-received message from the incoming message queue,
+  * removing it from the queue. The caller owns a reference to the
+@@ -4252,8 +4362,9 @@ static DBusDispatchStatus
+ _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection)
+ {
+   HAVE_LOCK_CHECK (connection);
+-  
+-  if (connection->n_incoming > 0)
++  if (connection->dispatch_disabled && _dbus_connection_get_is_connected_unlocked(connection))
++    return DBUS_DISPATCH_COMPLETE;
++  else if (connection->n_incoming > 0)
+     return DBUS_DISPATCH_DATA_REMAINS;
+   else if (!_dbus_transport_queue_messages (connection->transport))
+     return DBUS_DISPATCH_NEED_MEMORY;
+@@ -4716,6 +4827,8 @@ dbus_connection_dispatch (DBusConnection *connection)
+   
+   CONNECTION_LOCK (connection);
+ 
++  if (result == DBUS_HANDLER_RESULT_LATER)
++      goto out;
+   if (result == DBUS_HANDLER_RESULT_NEED_MEMORY)
+     {
+       _dbus_verbose ("No memory\n");
+@@ -4838,9 +4951,11 @@ dbus_connection_dispatch (DBusConnection *connection)
+                  connection);
+   
+  out:
+-  if (result == DBUS_HANDLER_RESULT_NEED_MEMORY)
++  if (result == DBUS_HANDLER_RESULT_LATER ||
++      result == DBUS_HANDLER_RESULT_NEED_MEMORY)
+     {
+-      _dbus_verbose ("out of memory\n");
++      if (result == DBUS_HANDLER_RESULT_NEED_MEMORY)
++        _dbus_verbose ("out of memory\n");
+       
+       /* Put message back, and we'll start over.
+        * Yes this means handlers must be idempotent if they
+diff --git a/dbus/dbus-list.c b/dbus/dbus-list.c
+index 8e713c0..32ea871 100644
+--- a/dbus/dbus-list.c
++++ b/dbus/dbus-list.c
+@@ -458,6 +458,35 @@ _dbus_list_remove_last (DBusList **list,
+     return FALSE;
+ }
+ 
++/**
++ * Finds a value in the list. Returns the first link
++ * with value equal to the given data pointer.
++ * This is a linear-time operation.
++ * Returns #NULL if no value found that matches.
++ *
++ * @param list address of the list head.
++ * @param data the value to find.
++ * @returns the link if found
++ */
++DBusList*
++_dbus_list_find_first (DBusList **list,
++                       void      *data)
++{
++  DBusList *link;
++
++  link = _dbus_list_get_first_link (list);
++
++  while (link != NULL)
++    {
++      if (link->data == data)
++        return link;
++
++      link = _dbus_list_get_next_link (list, link);
++    }
++
++  return NULL;
++}
++
+ /**
+  * Finds a value in the list. Returns the last link
+  * with value equal to the given data pointer.
+diff --git a/dbus/dbus-list.h b/dbus/dbus-list.h
+index 9350a0d..fee9f1b 100644
+--- a/dbus/dbus-list.h
++++ b/dbus/dbus-list.h
+@@ -68,6 +68,9 @@ DBUS_PRIVATE_EXPORT
+ void        _dbus_list_remove_link        (DBusList **list,
+                                            DBusList  *link);
+ DBUS_PRIVATE_EXPORT
++DBusList*   _dbus_list_find_first         (DBusList **list,
++                                           void      *data);
++DBUS_PRIVATE_EXPORT
+ DBusList*   _dbus_list_find_last          (DBusList **list,
+                                            void      *data);
+ DBUS_PRIVATE_EXPORT
+diff --git a/dbus/dbus-shared.h b/dbus/dbus-shared.h
+index 7ab9103..e5bfbed 100644
+--- a/dbus/dbus-shared.h
++++ b/dbus/dbus-shared.h
+@@ -67,7 +67,8 @@ typedef enum
+ {
+   DBUS_HANDLER_RESULT_HANDLED,         /**< Message has had its effect - no need to run more handlers. */ 
+   DBUS_HANDLER_RESULT_NOT_YET_HANDLED, /**< Message has not had any effect - see if other handlers want it. */
+-  DBUS_HANDLER_RESULT_NEED_MEMORY      /**< Need more memory in order to return #DBUS_HANDLER_RESULT_HANDLED or #DBUS_HANDLER_RESULT_NOT_YET_HANDLED. Please try again later with more memory. */
++  DBUS_HANDLER_RESULT_NEED_MEMORY,     /**< Need more memory in order to return #DBUS_HANDLER_RESULT_HANDLED or #DBUS_HANDLER_RESULT_NOT_YET_HANDLED. Please try again later with more memory. */
++  DBUS_HANDLER_RESULT_LATER            /**< Message dispatch deferred due to pending policy check */
+ } DBusHandlerResult;
+ 
+ /* Bus names */
+-- 
+2.21.1
+