attempting at fixing RRC

RRC does not work very well when one UE goes away and comes
back in some situations.

This commit is an attempt at making things work better.

It is probably not the end of the story.

openair2/RRC/LITE/rrc_eNB.c

@@ -4191,9 +4191,11 @@ rrc_eNB_decode_ccch(
              * the current one must be removed from MAC/PHY (zombie UE)
              */
             if ((ue_context_p = rrc_eNB_ue_context_random_exist(ctxt_pP, random_value))) {
-//#warning "TODO: random_exist: remove UE from MAC/PHY (how?)"
-	      //              AssertFatal(0 == 1, "TODO: remove UE from MAC/PHY (how?)");
+              LOG_W(RRC, "new UE rnti %x (coming with random value) is already there as UE %x, removing %x from MAC/PHY\n",
+                    ctxt_pP->rnti, ue_context_p->ue_context.rnti, ctxt_pP->rnti);
+	      rrc_mac_remove_ue(ctxt_pP->module_id, ctxt_pP->rnti);
               ue_context_p = NULL;
+              return 0;
             } else {
               ue_context_p = rrc_eNB_get_next_free_ue_context(ctxt_pP, random_value);
             }
@@ -4204,9 +4206,8 @@ rrc_eNB_decode_ccch(
             m_tmsi_t   m_tmsi   = BIT_STRING_to_uint32(&s_TMSI.m_TMSI);
             random_value = (((uint64_t)mme_code) << 32) | m_tmsi;
             if ((ue_context_p = rrc_eNB_ue_context_stmsi_exist(ctxt_pP, mme_code, m_tmsi))) {
-
-		//#warning "TODO: stmsi_exist: remove UE from MAC/PHY (how?)"
 	      LOG_I(RRC," S-TMSI exists, ue_context_p %p, old rnti %x => %x\n",ue_context_p,ue_context_p->ue_context.rnti,ctxt_pP->rnti);
+	      rrc_mac_remove_ue(ctxt_pP->module_id, ue_context_p->ue_context.rnti);
 	      stmsi_received=1;
               /* replace rnti in the context */
               /* for that, remove the context from the RB tree */
@@ -4218,8 +4219,6 @@ rrc_eNB_decode_ccch(
               /* reset timers */
               ue_context_p->ue_context.ul_failure_timer = 0;
               ue_context_p->ue_context.ue_release_timer = 0;
-	      //   AssertFatal(0 == 1, "TODO: remove UE from MAC/PHY (how?)");
-	      //              ue_context_p = NULL;
             } else {
 	      LOG_I(RRC," S-TMSI doesn't exist, setting Initialue_identity_s_TMSI.m_tmsi to %p => %x\n",ue_context_p,m_tmsi);
               ue_context_p = rrc_eNB_get_next_free_ue_context(ctxt_pP, NOT_A_RANDOM_UE_IDENTITY);
@@ -4230,7 +4229,8 @@ rrc_eNB_decode_ccch(
 	        ue_context_p->ue_context.Initialue_identity_s_TMSI.mme_code = mme_code;
 	        ue_context_p->ue_context.Initialue_identity_s_TMSI.m_tmsi = m_tmsi;
               } else {
-                break;
+                /* TODO: do we have to break here? */
+                //break;
               }
             }