SKE: When failure is received mark SKE always failed

[silc.git] / lib / silcske / silcske.c

diff --git a/lib/silcske/silcske.c b/lib/silcske/silcske.c
index 00d393229239f3a2bba9520c8c4e1bfcd6f153d1..df641f61c8feda7d621c1c1b749f2ac18a79712c 100644 (file)
--- a/lib/silcske/silcske.c
+++ b/lib/silcske/silcske.c
@@ -73,6 +73,41 @@ static SilcBool silc_ske_packet_send(SilcSKE ske,
                                     const unsigned char *data,
                                     SilcUInt32 data_len);
 
+/*
+ * Notify the owner of the ske that we failed.  Ensures that we don't make the
+ * same callout twice, as the notification callback routines are not designed
+ * to handle that case.
+ */
+static void silc_ske_notify_failure(SilcSKE ske)
+{
+  SILC_LOG_DEBUG(("Notifying SKE %p owner of failure (failure_notified = %d)",
+                 ske, ske->failure_notified));
+
+  /*
+   * First, check if we have already made a failure callout.  If so, then we
+   * will stop here.
+   */
+  if (ske->failure_notified)
+    return;
+
+  /*
+   * Mark ourselves as having already sent the failure notification here and
+   * now.
+   */
+  ske->failure_notified = TRUE;
+
+  SILC_LOG_DEBUG(("Deliver failure notification for SKE %p (%s)",
+                 ske, ske->responder ? "responder" : "initiator"));
+
+  /*
+   * Finally, make the call to the owner's registered failure callback.
+   */
+  if (ske->responder)
+    silc_fsm_next(&ske->fsm, silc_ske_st_responder_failure);
+  else
+    silc_fsm_next(&ske->fsm, silc_ske_st_initiator_failure);
+}
+
 /* Packet callback */
 
 static SilcBool silc_ske_packet_receive(SilcPacketEngine engine,
@@ -107,12 +142,8 @@ static SilcBool silc_ske_packet_receive(SilcPacketEngine engine,
   }
 
   /* See if received failure from remote */
-  if (packet->type == SILC_PACKET_FAILURE) {
-    if (ske->responder)
-      silc_fsm_next(&ske->fsm, silc_ske_st_responder_failure);
-    else
-      silc_fsm_next(&ske->fsm, silc_ske_st_initiator_failure);
-  }
+  if (packet->type == SILC_PACKET_FAILURE)
+    silc_ske_notify_failure(ske);
 
   /* Handle rekey and SUCCESS packets synchronously.  After SUCCESS packets
      they keys are taken into use immediately, hence the synchronous
@@ -895,10 +926,7 @@ SILC_TASK_CALLBACK(silc_ske_packet_send_retry)
     silc_free(ske->retrans.data);
     ske->retrans.data = NULL;
     ske->status = SILC_SKE_STATUS_TIMEOUT;
-    if (ske->responder)
-      silc_fsm_next(&ske->fsm, silc_ske_st_responder_failure);
-    else
-      silc_fsm_next(&ske->fsm, silc_ske_st_initiator_failure);
+        silc_ske_notify_failure(ske);
     silc_fsm_continue_sync(&ske->fsm);
     return;
   }
@@ -973,7 +1001,7 @@ static void silc_ske_finished(SilcFSM fsm, void *fsm_context,
                              void *destructor_context)
 {
   SilcSKE ske = fsm_context;
-    silc_ske_free(ske);
+  silc_ske_free(ske);
 }
 
 /* Key exchange timeout task callback */
@@ -986,10 +1014,7 @@ SILC_TASK_CALLBACK(silc_ske_timeout)
 
   ske->packet = NULL;
   ske->status = SILC_SKE_STATUS_TIMEOUT;
-  if (ske->responder)
-    silc_fsm_next(&ske->fsm, silc_ske_st_responder_failure);
-  else
-    silc_fsm_next(&ske->fsm, silc_ske_st_initiator_failure);
+  silc_ske_notify_failure(ske);
 
   silc_fsm_continue_sync(&ske->fsm);
 }
@@ -1037,18 +1062,28 @@ void silc_ske_free(SilcSKE ske)
   if (!ske)
     return;
 
-  SILC_LOG_DEBUG(("Freeing Key Exchange object %p: aborted=%u refcount=%hu", ske, ske->aborted, ske->refcnt));
+  SILC_LOG_DEBUG(("Freeing Key Exchange object %p: aborted=%u refcount=%hu",
+                 ske, ske->aborted, ske->refcnt));
 
-    if (ske->aborted) {
-      /* If already aborted, destroy the session immediately */
-      ske->packet = NULL;
-      ske->status = SILC_SKE_STATUS_ERROR;
-      if (ske->responder)
-       silc_fsm_next(&ske->fsm, silc_ske_st_responder_failure);
-      else
-       silc_fsm_next(&ske->fsm, silc_ske_st_initiator_failure);
+  if (ske->aborted) {
+    /*
+     * If already aborted, destroy the session immediately.  Only do the
+     * notification work if we have not already though, as doing so twice
+     * results in memory corruption.  We may have silc_ske_free called
+     * twice, once when the abort is requested, and then again when the
+     * FSM finish routine is called.  We have to be prepared to handle
+     * that case.
+     */
+    ske->packet         = NULL;
+    ske->status         = SILC_SKE_STATUS_ERROR;
+
+    silc_ske_notify_failure(ske);
+
+    if (silc_fsm_is_started(&ske->fsm))
       silc_fsm_continue_sync(&ske->fsm);
-    }
+    else
+      SILC_LOG_DEBUG(("Not continuing FSM as it's finished for SKE %p", ske));
+  }
 
   ske->refcnt--;
   if (ske->refcnt > 0)
@@ -1774,10 +1809,10 @@ SILC_FSM_STATE(silc_ske_st_initiator_failure)
 
   if (ske->packet && silc_buffer_len(&ske->packet->buffer) == 4) {
     SILC_GET32_MSB(error, ske->packet->buffer.data);
-    ske->status = error;
     silc_packet_free(ske->packet);
     ske->packet = NULL;
   }
+  ske->status = error;
 
   SILC_LOG_DEBUG(("Error %s (%d) received during key exchange",
                  silc_ske_map_status(ske->status), ske->status));
@@ -1798,7 +1833,8 @@ SilcAsyncOperation silc_ske_initiator(SilcSKE ske,
                                      SilcSKEParams params,
                                      SilcSKEStartPayload start_payload)
 {
-  SILC_LOG_DEBUG(("Start SKE %p as initiator; stream=%p; params=%p; start_payload=%p", ske, stream, params, start_payload));
+  SILC_LOG_DEBUG(("Start SKE %p as initiator; stream=%p; params=%p; "
+                 "start_payload=%p", ske, stream, params, start_payload));
 
   if (!ske || !stream || !params || !params->version)
     return NULL;
@@ -2347,10 +2383,10 @@ SILC_FSM_STATE(silc_ske_st_responder_failure)
 
   if (ske->packet && silc_buffer_len(&ske->packet->buffer) == 4) {
     SILC_GET32_MSB(error, ske->packet->buffer.data);
-    ske->status = error;
     silc_packet_free(ske->packet);
     ske->packet = NULL;
   }
+  ske->status = error;
 
   silc_packet_stream_unlink(ske->stream, &silc_ske_stream_cbs, ske);
   silc_schedule_task_del_by_context(ske->schedule, ske);