s1ap - handle invalid or repeated erab ids in s1ap erab release command

lib/include/srsran/adt/circular_map.h

@@ -233,7 +233,7 @@ public:
 
   iterator       begin() { return iterator(this, 0); }
   iterator       end() { return iterator(this, N); }
-  const_iterator begin() const { return iterator(this, 0); }
+  const_iterator begin() const { return const_iterator(this, 0); }
   const_iterator end() const { return const_iterator(this, N); }
 
   iterator find(K id)

lib/include/srsran/interfaces/enb_rrc_interfaces.h

@@ -34,9 +34,8 @@ public:
   virtual bool has_erab(uint16_t rnti, uint32_t erab_id) const                              = 0;
   virtual bool release_erabs(uint32_t rnti)                                                 = 0;
   virtual void release_erabs(uint32_t                               rnti,
-                             const asn1::s1ap::erab_release_cmd_s& msg,
-                             std::vector<uint16_t>*                erabs_released,
-                             std::vector<uint16_t>*                erabs_failed_to_release)                = 0;
+                             srsran::const_span<uint16_t>           erabs_to_release,
+                             const asn1::unbounded_octstring<true>* nas_pdu)                = 0;
   virtual void add_paging_id(uint32_t ueid, const asn1::s1ap::ue_paging_id_c& ue_paging_id) = 0;
 
   /**

srsenb/hdr/common/common_enb.h

@@ -26,6 +26,8 @@ namespace srsenb {
 
 #define SRSENB_N_SRB 3
 #define SRSENB_MAX_UES 64
+const uint32_t MAX_ERAB_ID   = 15;
+const uint32_t MAX_NOF_ERABS = 16;
 
 using srsran::lte_drb;
 using srsran::lte_srb;

srsenb/hdr/stack/rrc/rrc.h

@@ -92,9 +92,8 @@ public:
                       const asn1::unbounded_octstring<true>*     nas_pdu);
   bool release_erabs(uint32_t rnti) override;
   void release_erabs(uint32_t                               rnti,
-                     const asn1::s1ap::erab_release_cmd_s& msg,
-                     std::vector<uint16_t>*                erabs_released,
-                     std::vector<uint16_t>*                erabs_failed_to_release) override;
+                     srsran::const_span<uint16_t>           erabs_to_release,
+                     const asn1::unbounded_octstring<true>* nas_pdu) override;
   void add_paging_id(uint32_t ueid, const asn1::s1ap::ue_paging_id_c& UEPagingID) override;
   void ho_preparation_complete(uint16_t                     rnti,
                                bool                         is_success,

srsenb/hdr/stack/upper/s1ap.h

@@ -16,6 +16,7 @@
 #include <map>
 
 #include "srsenb/hdr/common/common_enb.h"
+#include "srsran/adt/circular_map.h"
 #include "srsran/common/buffer_pool.h"
 #include "srsran/common/common.h"
 #include "srsran/common/s1ap_pcap.h"
@@ -237,8 +238,9 @@ private:
     bool send_initial_ctxt_setup_response(const asn1::s1ap::init_context_setup_resp_s& res_);
     bool send_initial_ctxt_setup_failure();
     bool send_erab_setup_response(const asn1::s1ap::erab_setup_resp_s& res_);
-    bool send_erab_release_response(const std::vector<uint16_t>& erabs_successfully_released,
-                                    const std::vector<uint16_t>& erabs_failed_to_release);
+    bool send_erab_release_response(
+        const srsran::bounded_vector<uint16_t, MAX_NOF_ERABS>&                               erabs_released,
+        const srsran::static_circular_map<uint16_t, asn1::s1ap::erab_item_s, MAX_NOF_ERABS>& erabs_failed_to_release);
     bool send_erab_modify_response(
         srsran::const_span<const asn1::s1ap::erab_to_be_modified_item_bearer_mod_req_s*> erabs_modified,
         srsran::const_span<std::pair<uint16_t, asn1::s1ap::cause_c> >                    erabs_failed_to_modify);

srsenb/src/stack/rrc/rrc.cc

@@ -359,9 +359,8 @@ bool rrc::release_erabs(uint32_t rnti)
 }
 
 void rrc::release_erabs(uint32_t                               rnti,
-                        const asn1::s1ap::erab_release_cmd_s& msg,
-                        std::vector<uint16_t>*                erabs_released,
-                        std::vector<uint16_t>*                erabs_failed_to_release)
+                        srsran::const_span<uint16_t>           erabs_to_release,
+                        const asn1::unbounded_octstring<true>* nas_pdu)
 {
   logger.info("Releasing E-RAB for 0x%x", rnti);
   auto user_it = users.find(rnti);
@@ -371,18 +370,10 @@ void rrc::release_erabs(uint32_t                              rnti,
     return;
   }
 
-  for (uint32_t i = 0; i < msg.protocol_ies.erab_to_be_released_list.value.size(); i++) {
-    const asn1::s1ap::erab_item_s& erab_to_release =
-        msg.protocol_ies.erab_to_be_released_list.value[i].value.erab_item();
-    bool ret = user_it->second->release_erab(erab_to_release.erab_id);
-    if (ret) {
-      erabs_released->push_back(erab_to_release.erab_id);
-    } else {
-      erabs_failed_to_release->push_back(erab_to_release.erab_id);
-    }
+  for (uint16_t erab_id : erabs_to_release) {
+    bool ret = user_it->second->release_erab(erab_id);
+    srsran_expect(ret, "E-RAB id=%d not found", erab_id);
   }
-  const asn1::unbounded_octstring<true>* nas_pdu =
-      msg.protocol_ies.nas_pdu_present ? &msg.protocol_ies.nas_pdu.value : nullptr;
   user_it->second->send_connection_reconf(nullptr, false, nas_pdu);
 }
 

srsenb/src/stack/upper/s1ap.cc

@@ -735,15 +735,18 @@ bool s1ap::handle_erabmodifyrequest(const erab_modify_request_s& msg)
     return false;
   }
 
-  // make a copy, sort by ERAB ID
   using erab_t        = erab_to_be_modified_item_bearer_mod_req_s;
   using failed_erab_t = std::pair<uint16_t, cause_c>;
-  srsran::bounded_vector<const erab_t*, 256> erab_mod_list;
-  std::vector<failed_erab_t>                 erabs_failed_to_modify;
-  auto&                                      msg_erabs = msg.protocol_ies.erab_to_be_modified_list_bearer_mod_req.value;
+  srsran::bounded_vector<const erab_t*, MAX_ERAB_ID + 1> erab_mod_list;
+  srsran::bounded_vector<failed_erab_t, MAX_ERAB_ID + 1> erabs_failed_to_modify;
+  const auto& msg_erabs = msg.protocol_ies.erab_to_be_modified_list_bearer_mod_req.value;
 
-  for (const auto& msg_erab : msg_erabs) {
-    const erab_t& e = msg_erab.value.erab_to_be_modified_item_bearer_mod_req();
+  if (msg_erabs.size() > erab_mod_list.capacity()) {
+    logger.warning("Not handling more than %d E-RABs per modify request message.", erab_mod_list.capacity());
+  }
+
+  for (size_t i = 0; i < SRSRAN_MIN(msg_erabs.size(), erab_mod_list.capacity()); ++i) {
+    const erab_t& e = msg_erabs[i].value.erab_to_be_modified_item_bearer_mod_req();
 
     // Check if E-RAB exists. If not, add to "erabs_failed_to_modify" with "unknown_erab_id" cause
     if (not rrc->has_erab(u->ctxt.rnti, e.erab_id)) {
@@ -757,7 +760,7 @@ bool s1ap::handle_erabmodifyrequest(const erab_modify_request_s& msg)
     // with cause "multiple_erab_id_instances"
     for (const auto& msg_erab2 : msg_erabs) {
       const erab_t& e2 = msg_erab2.value.erab_to_be_modified_item_bearer_mod_req();
-      if (&msg_erab2 != &msg_erab and e2.erab_id == e.erab_id) {
+      if (&e2 != &e and e2.erab_id == e.erab_id) {
         cause_c cause;
         cause.set_radio_network().value = cause_radio_network_opts::multiple_erab_id_instances;
         erabs_failed_to_modify.emplace_back(e.erab_id, cause);
@@ -802,9 +805,6 @@ bool s1ap::handle_erabmodifyrequest(const erab_modify_request_s& msg)
  */
 bool s1ap::handle_erabreleasecommand(const erab_release_cmd_s& msg)
 {
-  std::vector<uint16_t> erab_successful_release = {};
-  std::vector<uint16_t> erab_failed_to_release  = {};
-
   if (msg.ext) {
     logger.warning("Not handling S1AP message extension");
   }
@@ -814,11 +814,56 @@ bool s1ap::handle_erabreleasecommand(const erab_release_cmd_s& msg)
     return false;
   }
 
+  srsran::bounded_vector<uint16_t, MAX_NOF_ERABS>                   erabs_to_release;
+  srsran::static_circular_map<uint16_t, erab_item_s, MAX_NOF_ERABS> erabs_failed_to_release;
+  const auto& msg_erabs = msg.protocol_ies.erab_to_be_released_list.value;
+
+  for (const auto& msg_erab : msg_erabs) {
+    const erab_item_s& e = msg_erab.value.erab_item();
+    if (e.erab_id >= erabs_failed_to_release.capacity()) {
+      logger.warning("Not handling E-RAB Ids above %zd", erabs_to_release.capacity());
+      continue;
+    }
+    if (erabs_to_release.full()) {
+      logger.warning("Not handling more than %zd releases per ERAB release request message",
+                     erabs_to_release.capacity());
+      break;
+    }
+
+    // Check if E-RAB exists. If not, add to "erabs_failed_to_modify" with "unknown_erab_id" cause
+    if (not rrc->has_erab(u->ctxt.rnti, e.erab_id)) {
+      erabs_failed_to_release.overwrite(e.erab_id, erab_item_s());
+      erabs_failed_to_release[e.erab_id].cause.set_radio_network().value = cause_radio_network_opts::unknown_erab_id;
+      continue;
+    }
+
+    // Check Repeated E-RABs in the modification list. If repeated, add to the list of "erabs_failed_to_modify"
+    // with cause "multiple_erab_id_instances"
+    for (const auto& msg_erab2 : msg_erabs) {
+      const erab_item_s& e2 = msg_erab2.value.erab_item();
+      if (&e2 != &e and e2.erab_id == e.erab_id) {
+        erabs_failed_to_release.overwrite(e.erab_id, erab_item_s());
+        erabs_failed_to_release[e.erab_id].cause.set_radio_network().value =
+            cause_radio_network_opts::multiple_erab_id_instances;
+        break;
+      }
+    }
+    if (erabs_failed_to_release.has_space(e.erab_id)) {
+      continue;
+    }
+
+    // Add to the list to modify
+    erabs_to_release.push_back(e.erab_id);
+  }
+
   // Release E-RABs from RRC
-  rrc->release_erabs(u->ctxt.rnti, msg, &erab_successful_release, &erab_failed_to_release);
+  std::sort(erabs_to_release.begin(), erabs_to_release.end());
+  erabs_to_release.erase(std::unique(erabs_to_release.begin(), erabs_to_release.end()), erabs_to_release.end());
+  rrc->release_erabs(
+      u->ctxt.rnti, erabs_to_release, msg.protocol_ies.nas_pdu_present ? &msg.protocol_ies.nas_pdu.value : nullptr);
 
   // Send E-RAB release response back to the MME
-  if (not u->send_erab_release_response(erab_successful_release, erab_failed_to_release)) {
+  if (not u->send_erab_release_response(erabs_to_release, erabs_failed_to_release)) {
     logger.info("Failed to send ERABReleaseResponse");
     return false;
   }
@@ -1391,8 +1436,9 @@ bool s1ap::ue::send_uectxtmodifyfailure(const cause_c& cause)
  * @param erabs_failed_to_release
  * @return true if message was sent
  */
-bool s1ap::ue::send_erab_release_response(const std::vector<uint16_t>& erabs_successfully_released,
-                                          const std::vector<uint16_t>& erabs_failed_to_release)
+bool s1ap::ue::send_erab_release_response(
+    const srsran::bounded_vector<uint16_t, MAX_NOF_ERABS>&                               erabs_released,
+    const srsran::static_circular_map<uint16_t, asn1::s1ap::erab_item_s, MAX_NOF_ERABS>& erabs_failed_to_release)
 {
   if (not s1ap_ptr->mme_connected) {
     return false;
@@ -1406,14 +1452,14 @@ bool s1ap::ue::send_erab_release_response(const std::vector<uint16_t>& erabs_suc
   container.mme_ue_s1ap_id.value = ctxt.mme_ue_s1ap_id.value();
 
   // Fill in which E-RABs were successfully released
-  if (not erabs_successfully_released.empty()) {
+  if (not erabs_released.empty()) {
     container.erab_release_list_bearer_rel_comp_present = true;
-    container.erab_release_list_bearer_rel_comp.value.resize(erabs_successfully_released.size());
-    for (uint32_t i = 0; i < container.erab_release_list_bearer_rel_comp.value.size(); i++) {
+    container.erab_release_list_bearer_rel_comp.value.resize(erabs_released.size());
+    for (size_t i = 0; i < erabs_released.size(); ++i) {
       container.erab_release_list_bearer_rel_comp.value[i].load_info_obj(
           ASN1_S1AP_ID_ERAB_RELEASE_ITEM_BEARER_REL_COMP);
       container.erab_release_list_bearer_rel_comp.value[i].value.erab_release_item_bearer_rel_comp().erab_id =
-          erabs_successfully_released[i];
+          erabs_released[i];
     }
   }
 
@@ -1421,12 +1467,11 @@ bool s1ap::ue::send_erab_release_response(const std::vector<uint16_t>& erabs_suc
   if (not erabs_failed_to_release.empty()) {
     container.erab_failed_to_release_list_present = true;
     container.erab_failed_to_release_list.value.resize(erabs_failed_to_release.size());
-    for (uint32_t i = 0; i < container.erab_failed_to_release_list.value.size(); i++) {
-      container.erab_failed_to_release_list.value[i].load_info_obj(ASN1_S1AP_ID_ERAB_ITEM);
-      container.erab_failed_to_release_list.value[i].value.erab_item().erab_id = erabs_failed_to_release[i];
-      container.erab_failed_to_release_list.value[i].value.erab_item().cause.set(asn1::s1ap::cause_c::types::misc);
-      container.erab_failed_to_release_list.value[i].value.erab_item().cause.misc() =
-          asn1::s1ap::cause_misc_opts::unspecified;
+    size_t count = 0;
+    for (const auto& erab : erabs_failed_to_release) {
+      container.erab_failed_to_release_list.value[count].load_info_obj(ASN1_S1AP_ID_ERAB_ITEM);
+      container.erab_failed_to_release_list.value[count].value.erab_item() = erab->second;
+      count++;
     }
   }
 

srsenb/test/common/dummy_classes.h

@@ -175,9 +175,8 @@ public:
   bool has_erab(uint16_t rnti, uint32_t erab_id) const override { return true; }
   bool release_erabs(uint32_t rnti) override { return true; }
   void release_erabs(uint32_t                               rnti,
-                     const asn1::s1ap::erab_release_cmd_s& msg,
-                     std::vector<uint16_t>*                erabs_released,
-                     std::vector<uint16_t>*                erabs_failed_to_release) override
+                     srsran::const_span<uint16_t>           erabs_to_release,
+                     const asn1::unbounded_octstring<true>* nas_pdu) override
   {}
   void add_paging_id(uint32_t ueid, const asn1::s1ap::ue_paging_id_c& ue_paging_id) override {}
   void ho_preparation_complete(uint16_t                     rnti,