From 9f7ae7a2b2e5472261007dbf6ae490095c40e4d4 Mon Sep 17 00:00:00 2001
From: Pedro Alvarez <pedro.alvarez@softwareradiosystems.com>
Date: Fri, 26 Nov 2021 11:38:00 +0000
Subject: [PATCH] gnb,ngap: Added simple allocation of lcids to
 ngap_ue_bearer_manager.

---
 .../hdr/stack/ngap/ngap_ue_bearer_manager.h   | 19 +++++++++++--------
 .../src/stack/ngap/ngap_ue_bearer_manager.cc  | 13 ++++++++++++-
 srsgnb/src/stack/ngap/ngap_ue_proc.cc         |  4 ++--
 3 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/srsgnb/hdr/stack/ngap/ngap_ue_bearer_manager.h b/srsgnb/hdr/stack/ngap/ngap_ue_bearer_manager.h
index 91f2d9855..361e4f46f 100644
--- a/srsgnb/hdr/stack/ngap/ngap_ue_bearer_manager.h
+++ b/srsgnb/hdr/stack/ngap/ngap_ue_bearer_manager.h
@@ -61,13 +61,16 @@ private:
   std::map<uint8_t, pdu_session_t> pdu_session_list;
   srslog::basic_logger&            logger;
 
-  int  add_gtpu_bearer(uint16_t                                    rnti,
-                       uint32_t                                    pdu_session_id,
-                       uint32_t                                    teid_out,
-                       asn1::bounded_bitstring<1, 160, true, true> address,
-                       pdu_session_t::gtpu_tunnel&                 tunnel, // out parameter
-                       const gtpu_interface_rrc::bearer_props*     props = nullptr);
-  void rem_gtpu_bearer(uint16_t rnti, uint32_t pdu_session_id);
+  std::map<uint32_t, uint32_t> next_lcid_list; // Map RNTI to next LCID to be allocated
+
+  int     add_gtpu_bearer(uint16_t                                    rnti,
+                          uint32_t                                    pdu_session_id,
+                          uint32_t                                    teid_out,
+                          asn1::bounded_bitstring<1, 160, true, true> address,
+                          pdu_session_t::gtpu_tunnel&                 tunnel, // out parameter
+                          const gtpu_interface_rrc::bearer_props*     props = nullptr);
+  void    rem_gtpu_bearer(uint16_t rnti, uint32_t pdu_session_id);
+  uint8_t allocate_lcid(uint32_t rnti);
 };
 } // namespace srsenb
-#endif // SRSENB_NGAP_UE_BEARER_MANAGER_H
\ No newline at end of file
+#endif // SRSENB_NGAP_UE_BEARER_MANAGER_H
diff --git a/srsgnb/src/stack/ngap/ngap_ue_bearer_manager.cc b/srsgnb/src/stack/ngap/ngap_ue_bearer_manager.cc
index ad336df4c..0f1c0ac4d 100644
--- a/srsgnb/src/stack/ngap/ngap_ue_bearer_manager.cc
+++ b/srsgnb/src/stack/ngap/ngap_ue_bearer_manager.cc
@@ -37,6 +37,8 @@ int ngap_ue_bearer_manager::add_pdu_session(uint16_t
     return SRSRAN_ERROR;
   }
 
+  lcid = allocate_lcid(rnti);
+
   // TODO: remove lcid and just use pdu_session_id and rnti as id for GTP tunnel
   int rtn = add_gtpu_bearer(rnti, pdu_session_id, teid_out, addr_out, tunnel);
   if (rtn != SRSRAN_SUCCESS) {
@@ -62,6 +64,7 @@ int ngap_ue_bearer_manager::reset_pdu_sessions(uint16_t rnti)
     auto pdu_session_id = iter->first;
     rem_gtpu_bearer(pdu_session_id, rnti);
   }
+  next_lcid_list.erase(rnti);
   return true;
 }
 
@@ -110,4 +113,12 @@ void ngap_ue_bearer_manager::rem_gtpu_bearer(uint16_t rnti, uint32_t pdu_session
   gtpu->rem_bearer(rnti, it->second.lcid);
 }
 
-} // namespace srsenb
\ No newline at end of file
+uint8_t ngap_ue_bearer_manager::allocate_lcid(uint32_t rnti)
+{
+  if (next_lcid_list.find(rnti) == next_lcid_list.end()) {
+    next_lcid_list[rnti] = 4;
+  }
+  return next_lcid_list[rnti]++;
+}
+
+} // namespace srsenb
diff --git a/srsgnb/src/stack/ngap/ngap_ue_proc.cc b/srsgnb/src/stack/ngap/ngap_ue_proc.cc
index 31f7b6247..e1e820f91 100644
--- a/srsgnb/src/stack/ngap/ngap_ue_proc.cc
+++ b/srsgnb/src/stack/ngap/ngap_ue_proc.cc
@@ -143,8 +143,8 @@ proc_outcome_t ngap_ue_pdu_session_res_setup_proc::init(const asn1::ngap_nr::pdu
 
   // TODO: Check cause
   asn1::ngap_nr::cause_c                      cause;
-  uint32_t                                    teid_in;
-  uint16_t                                    lcid;
+  uint32_t                                    teid_in = {};
+  uint16_t                                    lcid    = {};
   asn1::bounded_bitstring<1, 160, true, true> addr_in;
 
   if (bearer_manager->add_pdu_session(