Modify Bearer response parsed ok. Starting to setup the user-plane tunnels

srsepc/hdr/mme/mme_gtpc.h

@@ -51,6 +51,7 @@ public:
   void send_create_session_request(uint64_t imsi, uint32_t mme_s1ap_id);
   void handle_create_session_response(srslte::gtpc_pdu *cs_resp_pdu);
   void send_modify_bearer_request(erab_ctx_t *bearer_ctx);
+  void handle_modify_bearer_response(srslte::gtpc_pdu *mb_resp_pdu);
 
 private:
 

srsepc/hdr/mme/s1ap.h

@@ -87,6 +87,8 @@ public:
   bool handle_initial_context_setup_response(LIBLTE_S1AP_MESSAGE_INITIALCONTEXTSETUPRESPONSE_STRUCT *in_ctxt_resp);
   bool handle_nas_attach_complete(srslte::byte_buffer_t *nas_msg, srslte::byte_buffer_t *reply_msg, ue_ctx_t *ue_ctx);
 
+  void activate_eps_bearer(uint32_t mme_s1ap_id, uint8_t ebi);
+
   void print_enb_ctx_info(const enb_ctx_t &enb_ctx);
 
 private:

srsepc/hdr/spgw/spgw.h

@@ -56,6 +56,7 @@ typedef struct {
 typedef struct spgw_tunnel_ctx {
   uint64_t imsi;
   in_addr_t ue_ipv4;
+  uint8_t ebi;
   struct srslte::gtpc_f_teid_ie up_ctrl_fteid;
   struct srslte::gtpc_f_teid_ie up_user_fteid;
   struct srslte::gtpc_f_teid_ie dw_ctrl_fteid;

srsepc/src/mme/mme_gtpc.cc

@@ -190,5 +190,26 @@ mme_gtpc::send_modify_bearer_request(erab_ctx_t *erab_ctx)
   //
   srslte::gtpc_pdu mb_resp_pdu;
   m_spgw->handle_modify_bearer_request(&mb_req_pdu,&mb_resp_pdu);
+  handle_modify_bearer_response(&mb_resp_pdu);
+  return;
+}
+
+void
+mme_gtpc::handle_modify_bearer_response(srslte::gtpc_pdu *mb_resp_pdu)
+{
+  uint32_t mme_ctrl_teid = mb_resp_pdu->header.teid;
+  std::map<uint32_t,uint32_t>::iterator mme_s1ap_id_it = m_teid_to_mme_s1ap_id.find(mme_ctrl_teid);
+  if(mme_s1ap_id_it == m_teid_to_mme_s1ap_id.end())
+  {
+    m_mme_gtpc_log->error("Could not find MME S1AP Id from control TEID\n");
+    return;
+  }
+
+  uint8_t ebi = mb_resp_pdu->choice.modify_bearer_response.eps_bearer_context_modified.ebi;
+  m_mme_gtpc_log->debug("Activating EPS bearer with id %d\n", ebi);
+  m_s1ap->activate_eps_bearer(mme_s1ap_id_it->second,ebi);
+
+  return;
 }
+
 } //namespace srsepc

srsepc/src/mme/s1ap.cc

@@ -823,6 +823,26 @@ s1ap::handle_ue_context_release_request(LIBLTE_S1AP_MESSAGE_UECONTEXTRELEASEREQU
   return true;
 }
 
+void
+s1ap::activate_eps_bearer(uint32_t mme_s1ap_id, uint8_t ebi)
+{
+  std::map<uint32_t,ue_ctx_t*>::iterator ue_ctx_it = m_active_ues.find(mme_s1ap_id);
+  if(ue_ctx_it == m_active_ues.end())
+  {
+    m_s1ap_log->error("Could not find UE context\n");
+    return;
+  }
+  ue_ctx_t * ue_ctx = ue_ctx_it->second;
+  if (ue_ctx->erabs_ctx[ebi].state != ERAB_CTX_REQUESTED)
+  {
+    m_s1ap_log->error("EPS Bearer could not be activated. EPS Bearer id %d\n",ebi);
+    return;
+  }
+
+  ue_ctx->erabs_ctx[ebi].state = ERAB_ACTIVE;
+  m_s1ap_log->info("Activated EPS Bearer\n");
+  return;
+}
 
 void
 s1ap::print_enb_ctx_info(const enb_ctx_t &enb_ctx)

srsepc/src/spgw/spgw.cc

@@ -323,9 +323,11 @@ spgw::handle_create_session_request(struct srslte::gtpc_create_session_request *
   //Allocate UE IP
   in_addr_t ue_ip = get_new_ue_ipv4();
 
+  uint8_t default_bearer_id = 5;
   //Save the UE IP to User TEID map //TODO!!!
   spgw_tunnel_ctx_t *tunnel_ctx = new spgw_tunnel_ctx_t;
   tunnel_ctx->imsi = cs_req->imsi;
+  tunnel_ctx->ebi = default_bearer_id;
   tunnel_ctx->up_user_fteid.teid = spgw_uplink_user_teid;
   tunnel_ctx->up_user_fteid.ipv4 = m_s1u_addr.sin_addr.s_addr;
   tunnel_ctx->dw_ctrl_fteid.teid = cs_req->sender_f_teid.teid;
@@ -349,7 +351,7 @@ spgw::handle_create_session_request(struct srslte::gtpc_create_session_request *
   cs_resp->sender_f_teid.teid = spgw_uplink_ctrl_teid;
   cs_resp->sender_f_teid.ipv4 = 0;//FIXME This is not relevant, as the GTP-C is not transmitted over sockets yet.
   //Bearer context created
-  cs_resp->eps_bearer_context_created.ebi = 5;
+  cs_resp->eps_bearer_context_created.ebi = default_bearer_id;
   cs_resp->eps_bearer_context_created.cause.cause_value = srslte::GTPC_CAUSE_VALUE_REQUEST_ACCEPTED;
   cs_resp->eps_bearer_context_created.s1_u_sgw_f_teid_present=true;
   cs_resp->eps_bearer_context_created.s1_u_sgw_f_teid.teid = spgw_uplink_user_teid;
@@ -402,13 +404,17 @@ spgw::handle_modify_bearer_request(struct srslte::gtpc_pdu *mb_req_pdu, struct s
 
   //Setting up Modify bearer response PDU
   //Header
-  srslte::gtpc_header *header = &mb_req_pdu->header;
+  srslte::gtpc_header *header = &mb_resp_pdu->header;
   header->piggyback = false;
   header->teid_present = true;
   header->teid = tunnel_ctx->dw_ctrl_fteid.teid;  //
   header->type = srslte::GTPC_MSG_TYPE_MODIFY_BEARER_RESPONSE;
 
   //PDU
-  srslte::gtpc_modify_bearer_response *mb_resp = &mb_req_pdu->choice.modify_bearer_response;
+  srslte::gtpc_modify_bearer_response *mb_resp = &mb_resp_pdu->choice.modify_bearer_response;
+  mb_resp->cause.cause_value = srslte::GTPC_CAUSE_VALUE_REQUEST_ACCEPTED;
+  mb_resp->eps_bearer_context_modified.ebi = tunnel_ctx->ebi;
+  printf("%d %d\n",mb_resp->eps_bearer_context_modified.ebi, tunnel_ctx->ebi);
+  mb_resp->eps_bearer_context_modified.cause.cause_value = srslte::GTPC_CAUSE_VALUE_REQUEST_ACCEPTED;
 }
 } //namespace srsepc