From dcf5a727f2c18189b0f3177a2d387383131a3a2b Mon Sep 17 00:00:00 2001
From: Francisco Paisana <francisco.paisana@softwareradiosystems.com>
Date: Tue, 22 Sep 2020 15:07:24 +0200
Subject: [PATCH] do not send RRC release in case the eNB receives a S1AP
 UEContextRelease command and the UE is doing handover. Handle GTPU end marker

---
 lib/include/srslte/upper/gtpu.h |  2 +-
 srsenb/src/stack/rrc/rrc.cc     | 18 +++++++++++-------
 srsenb/src/stack/upper/gtpu.cc  |  6 ++++++
 3 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/lib/include/srslte/upper/gtpu.h b/lib/include/srslte/upper/gtpu.h
index 9ade8d6ce..31daf6966 100644
--- a/lib/include/srslte/upper/gtpu.h
+++ b/lib/include/srslte/upper/gtpu.h
@@ -106,7 +106,7 @@ inline bool gtpu_supported_msg_type_check(gtpu_header_t* header, srslte::log_ref
 {
   // msg_tpye
   if (header->message_type != GTPU_MSG_DATA_PDU && header->message_type != GTPU_MSG_ECHO_REQUEST &&
-      header->message_type != GTPU_MSG_ECHO_RESPONSE) {
+      header->message_type != GTPU_MSG_ECHO_RESPONSE && header->message_type != GTPU_MSG_END_MARKER) {
     gtpu_log->error("gtpu_header - Unhandled message type: 0x%x\n", header->message_type);
     return false;
   }
diff --git a/srsenb/src/stack/rrc/rrc.cc b/srsenb/src/stack/rrc/rrc.cc
index ba6a25edf..3aeb3461c 100644
--- a/srsenb/src/stack/rrc/rrc.cc
+++ b/srsenb/src/stack/rrc/rrc.cc
@@ -538,15 +538,19 @@ void rrc::process_release_complete(uint16_t rnti)
 {
   rrc_log->info("Received Release Complete rnti=0x%x\n", rnti);
   auto user_it = users.find(rnti);
-  if (user_it != users.end()) {
-    if (!user_it->second->is_idle()) {
-      rlc->clear_buffer(rnti);
-      user_it->second->send_connection_release();
-    }
+  if (user_it == users.end()) {
+    rrc_log->error("Received ReleaseComplete for unknown rnti=0x%x\n", rnti);
+    return;
+  }
+  ue* u = user_it->second.get();
+
+  if (u->is_idle() or u->mobility_handler->is_ho_running()) {
+    rem_user_thread(rnti);
+  } else if (not u->is_idle()) {
+    rlc->clear_buffer(rnti);
+    user_it->second->send_connection_release();
     // delay user deletion for ~50 TTI (until RRC release is sent)
     task_sched.defer_callback(50, [this, rnti]() { rem_user_thread(rnti); });
-  } else {
-    rrc_log->error("Received ReleaseComplete for unknown rnti=0x%x\n", rnti);
   }
 }
 
diff --git a/srsenb/src/stack/upper/gtpu.cc b/srsenb/src/stack/upper/gtpu.cc
index ef7b8e264..3f82424e4 100644
--- a/srsenb/src/stack/upper/gtpu.cc
+++ b/srsenb/src/stack/upper/gtpu.cc
@@ -280,6 +280,12 @@ void gtpu::handle_gtpu_s1u_rx_packet(srslte::unique_byte_buffer_t pdu, const soc
       }
       pdcp->write_sdu(rnti, lcid, std::move(pdu));
     } break;
+    case GTPU_MSG_END_MARKER: {
+      rnti_lcid_t rnti_lcid = teidin_to_rntilcid(header.teid);
+      uint16_t    rnti      = rnti_lcid.rnti;
+      gtpu_log->info("Received GTPU End Marker for rnti=0x%x.\n", rnti);
+      break;
+    }
     default:
       break;
   }