- added react method to to_state<...> transitions

- s1 handover composite state simplified
- the eNB now starts a HO cancellation when it receives an invalid
Handover Command
- the FSM log now prints the current state when it receives an unhandled
event

lib/include/srslte/common/fsm.h

@@ -246,8 +246,10 @@ struct apply_first_guard_pass<FSM, type_list<> > {
   template <typename SrcState, typename Event>
   static bool trigger(FSM* f, SrcState& s, const Event& ev)
   {
-    otherfsmDebug(
-        static_cast<typename FSM::derived_t*>(f), "unhandled event caught: \"%s\"\n", get_type_name<Event>().c_str());
+    otherfsmDebug(static_cast<typename FSM::derived_t*>(f),
+                  "unhandled event caught in state \"%s\": \"%s\"\n",
+                  get_type_name<SrcState>().c_str(),
+                  get_type_name<Event>().c_str());
     return false;
   }
 };
@@ -348,16 +350,23 @@ public:
             bool (Derived::*GuardFn)(SrcState&, const Event&) = nullptr>
   using upd = row<SrcState, SrcState, Event, ReactFn, GuardFn>;
 
-  template <typename DestState, typename Event, bool (Derived::*GuardFn)(const Event&) = nullptr>
+  template <typename DestState,
+            typename Event,
+            void (Derived::*ReactFn)(const Event&) = nullptr,
+            bool (Derived::*GuardFn)(const Event&) = nullptr>
   struct to_state {
     using dest_state_t                                       = DestState;
     using event_t                                            = Event;
+    constexpr static void (Derived::*react_fn)(const Event&) = ReactFn;
     constexpr static bool (Derived::*guard_fn)(const Event&) = GuardFn;
 
     template <typename SrcState>
     static bool react(derived_view* f, SrcState& s, const event_t& ev)
     {
       if (guard_fn == nullptr or (f->*guard_fn)(ev)) {
+        if (react_fn != nullptr) {
+          (f->*react_fn)(ev);
+        }
         return true;
       }
       return false;

srsenb/hdr/stack/rrc/rrc_mobility.h

@@ -153,7 +153,7 @@ private:
   struct wait_recfg_comp {};
   struct s1_source_ho_st : public subfsm_t<s1_source_ho_st> {
     ho_meas_report_ev report;
-    using ho_cmd_msg = srslte::unique_byte_buffer_t;
+    using ho_cmd_msg = asn1::rrc::ho_cmd_r8_ies_s;
 
     struct wait_ho_req_ack_st {
       void enter(s1_source_ho_st* f, const ho_meas_report_ev& ev);
@@ -165,9 +165,8 @@ private:
     explicit s1_source_ho_st(rrc_mobility* parent_) : base_t(parent_) {}
 
   private:
-    bool send_ho_cmd(wait_ho_req_ack_st& s, const ho_cmd_msg& container);
-    void handle_ho_cancel(wait_ho_req_ack_st& s, const ho_cancel_ev& ev);
-    void handle_ho_cancel(status_transfer_st& s, const ho_cancel_ev& ev);
+    void send_ho_cmd(wait_ho_req_ack_st& s, const ho_cmd_msg& ho_cmd);
+    void handle_ho_cancel(const ho_cancel_ev& ev);
 
   protected:
     using fsm = s1_source_ho_st;
@@ -177,10 +176,8 @@ private:
     //           Start                 Target                   Event       Action                 Guard
     //      +-------------------+------------------+---------------------+-----------------------+---------------------+
     to_state<                     idle_st,            srslte::failure_ev                                               >,
-         row< wait_ho_req_ack_st, status_transfer_st, ho_cmd_msg,          nullptr,               &fsm::send_ho_cmd    >,
-         row< wait_ho_req_ack_st, idle_st,            ho_cmd_msg                                                       >,
-         row< wait_ho_req_ack_st, idle_st,            ho_cancel_ev,        &fsm::handle_ho_cancel                      >,
-         row< status_transfer_st, idle_st,            ho_cancel_ev,        &fsm::handle_ho_cancel                      >
+    to_state<                     idle_st,            ho_cancel_ev,        &fsm::handle_ho_cancel                      >,
+         row< wait_ho_req_ack_st, status_transfer_st, ho_cmd_msg,          &fsm::send_ho_cmd                           >
     //      +-------------------+------------------+---------------------+-----------------------+---------------------+
     >;
     // clang-format on

srsenb/src/stack/rrc/rrc_mobility.cc

@@ -774,7 +774,25 @@ void rrc::ue::rrc_mobility::handle_ho_preparation_complete(bool is_success, srsl
     trigger(srslte::failure_ev{});
     return;
   }
-  trigger(std::move(container));
+  /* unpack RRC HOCmd struct and perform sanity checks */
+  asn1::rrc::ho_cmd_s rrchocmd;
+  {
+    asn1::cbit_ref bref(container->msg, container->N_bytes);
+    if (rrchocmd.unpack(bref) != asn1::SRSASN_SUCCESS) {
+      get_log()->warning("Unpacking of RRC HOCommand was unsuccessful\n");
+      get_log()->warning_hex(container->msg, container->N_bytes, "Received container:\n");
+      trigger(ho_cancel_ev{});
+      return;
+    }
+  }
+  if (rrchocmd.crit_exts.type().value != c1_or_crit_ext_opts::c1 or
+      rrchocmd.crit_exts.c1().type().value != ho_cmd_s::crit_exts_c_::c1_c_::types_opts::ho_cmd_r8) {
+    get_log()->warning("Only handling r8 Handover Commands\n");
+    trigger(ho_cancel_ev{});
+    return;
+  }
+
+  trigger(rrchocmd.crit_exts.c1().ho_cmd_r8());
 }
 
 bool rrc::ue::rrc_mobility::start_s1_tenb_ho(
@@ -996,62 +1014,40 @@ void rrc::ue::rrc_mobility::s1_source_ho_st::wait_ho_req_ack_st::enter(s1_source
   }
 }
 
-bool rrc::ue::rrc_mobility::s1_source_ho_st::send_ho_cmd(wait_ho_req_ack_st&                 s,
-                                                         const srslte::unique_byte_buffer_t& container)
-{
-  /* unpack RRC HOCmd struct and perform sanity checks */
-  asn1::rrc::ho_cmd_s rrchocmd;
+void rrc::ue::rrc_mobility::s1_source_ho_st::send_ho_cmd(wait_ho_req_ack_st& s, const ho_cmd_r8_ies_s& ho_cmd)
 {
-    asn1::cbit_ref bref(container->msg, container->N_bytes);
-    if (rrchocmd.unpack(bref) != asn1::SRSASN_SUCCESS) {
-      get_log()->warning("Unpacking of RRC HOCommand was unsuccessful\n");
-      get_log()->warning_hex(container->msg, container->N_bytes, "Received container:\n");
-      return false;
-    }
-  }
-  if (rrchocmd.crit_exts.type().value != c1_or_crit_ext_opts::c1 or
-      rrchocmd.crit_exts.c1().type().value != ho_cmd_s::crit_exts_c_::c1_c_::types_opts::ho_cmd_r8) {
-    get_log()->warning("Only handling r8 Handover Commands\n");
-    return false;
-  }
-
   /* unpack DL-DCCH message containing the RRCRonnectionReconf (with MobilityInfo) to be sent to the UE */
   asn1::rrc::dl_dcch_msg_s dl_dcch_msg;
   {
-    asn1::cbit_ref bref(&rrchocmd.crit_exts.c1().ho_cmd_r8().ho_cmd_msg[0],
-                        rrchocmd.crit_exts.c1().ho_cmd_r8().ho_cmd_msg.size());
+    asn1::cbit_ref bref(&ho_cmd.ho_cmd_msg[0], ho_cmd.ho_cmd_msg.size());
     if (dl_dcch_msg.unpack(bref) != asn1::SRSASN_SUCCESS) {
       get_log()->warning("Unpacking of RRC DL-DCCH message with HO Command was unsuccessful.\n");
-      return false;
+      trigger(ho_cancel_ev{});
+      return;
     }
   }
   if (dl_dcch_msg.msg.type().value != dl_dcch_msg_type_c::types_opts::c1 or
       dl_dcch_msg.msg.c1().type().value != dl_dcch_msg_type_c::c1_c_::types_opts::rrc_conn_recfg) {
     get_log()->warning("HandoverCommand is expected to contain an RRC Connection Reconf message inside\n");
-    return false;
+    trigger(ho_cancel_ev{});
+    return;
   }
   asn1::rrc::rrc_conn_recfg_s& reconf = dl_dcch_msg.msg.c1().rrc_conn_recfg();
   if (not reconf.crit_exts.c1().rrc_conn_recfg_r8().mob_ctrl_info_present) {
     get_log()->warning("HandoverCommand is expected to have mobility control subfield\n");
-    return false;
+    trigger(ho_cancel_ev{});
+    return;
   }
 
   /* Send HO Command to UE */
   if (not parent_fsm()->rrc_ue->send_dl_dcch(&dl_dcch_msg)) {
-    return false;
-  }
-
-  return true;
+    trigger(ho_cancel_ev{});
+    return;
   }
-
-//! Called in Source ENB during S1-Handover when there was a Reestablishment Request
-void rrc::ue::rrc_mobility::s1_source_ho_st::handle_ho_cancel(wait_ho_req_ack_st& s, const ho_cancel_ev& ev)
-{
-  parent_fsm()->rrc_enb->s1ap->send_ho_cancel(parent_fsm()->rrc_ue->rnti);
 }
 
 //! Called in Source ENB during S1-Handover when there was a Reestablishment Request
-void rrc::ue::rrc_mobility::s1_source_ho_st::handle_ho_cancel(status_transfer_st& s, const ho_cancel_ev& ev)
+void rrc::ue::rrc_mobility::s1_source_ho_st::handle_ho_cancel(const ho_cancel_ev& ev)
 {
   parent_fsm()->rrc_enb->s1ap->send_ho_cancel(parent_fsm()->rrc_ue->rnti);
 }