ikev2: Don't increase expected MID after handling MID sync message

If the responder never sent a message the expected MID is 0.  While
the sent MID (M1) SHOULD be increased beyond the known value, it's
not necessarily the case.
Since M2 - 1 would then equal UINT_MAX setting that MID would get ignored
and while we'd return 0 in the notify we'd actually expect 1 afterwards.

diff --git a/src/libcharon/sa/ikev2/task_manager_v2.c b/src/libcharon/sa/ikev2/task_manager_v2.c
index debfe23fae917cd3e1dc21e74e30f568f0f496cf..778349c08bd0c890d7c9a00d36c8a306d31c3772 100644 (file)
--- a/src/libcharon/sa/ikev2/task_manager_v2.c
+++ b/src/libcharon/sa/ikev2/task_manager_v2.c
@@ -918,6 +918,9 @@ static status_t build_response(private_task_manager_t *this, message_t *request)
                /* we don't want to resend messages to sync MIDs if requests with the
                 * previous MID arrive */
                clear_packets(this->responding.packets);
+               /* avoid increasing the expected message ID after handling a message
+                * to sync MIDs with MID 0 */
+               return NEED_MORE;
        }
 
        array_compress(this->passive_tasks);

diff --git a/src/libcharon/sa/ikev2/tasks/ike_mid_sync.c b/src/libcharon/sa/ikev2/tasks/ike_mid_sync.c
index 9967697dd30f42e0a3969f0d3227f460cc3e23a8..d7de113036f744424c937c4ad2022a028a2299a7 100644 (file)
--- a/src/libcharon/sa/ikev2/tasks/ike_mid_sync.c
+++ b/src/libcharon/sa/ikev2/tasks/ike_mid_sync.c
@@ -180,9 +180,7 @@ METHOD(task_t, process, status_t,
        m2 = max(this->send, resp);
        if (resp != m2)
        {
-               /* after responding to this message the expected message ID is increased
-                * by one so we reduce it here */
-               this->ike_sa->set_message_id(this->ike_sa, FALSE, m2 - 1);
+               this->ike_sa->set_message_id(this->ike_sa, FALSE, m2);
        }
        init = this->ike_sa->get_message_id(this->ike_sa, TRUE);
        p2 = max(this->recv, has_active_tasks(this) ? init + 1 : init);