fix(amf): handle and proper response the error code from subscriberdb…

… during authentication

Signed-off-by: RahulKalsangra <rahul.kalsangra@wavelabs.ai>

lte/gateway/c/core/oai/include/amf_config.h

@@ -31,6 +31,8 @@
 #define MAX_APN_CORRECTION_MAP_LIST 10
 #define AMF_S_NSSAI_ST_DEFAULT_VALUE 1
 #define AMF_S_NSSAI_SD_INVALID_VALUE 0xffffff
+#define AUTHENTICATION_COUNTER_MAX_RETRY "AUTHENTICATION_MAX_RETRY"
+#define AUTHENTICATION_RETRY_TIMER_EXPIRY_MSECS "AUTHENTICATION_TIMER_EXPIRY"
 
 #define AMF_CONFIG_STRING_AMF_CONFIG "AMF"
 #define AMF_CONFIG_STRING_DEFAULT_DNS_IPV4_ADDRESS "DEFAULT_DNS_IPV4_ADDRESS"
@@ -179,6 +181,8 @@ typedef struct amf_config_s {
   } ipv4;
   bstring amf_name;
   bstring default_dnn;
+  uint32_t auth_retry_interval;
+  uint32_t auth_retry_max_count;
 } amf_config_t;
 
 int amf_app_init(amf_config_t*);

lte/gateway/c/core/oai/tasks/amf/amf_app_ue_context_and_proc.h

@@ -105,7 +105,7 @@ struct amf_procedures_t;
 #define PDU_ADDR_IPV4_LEN 0x4
 #define GNB_IPV4_ADDR_LEN 4
 #define GNB_TEID_LEN 4
-
+#define DIAMETER_TOO_BUSY 3004
 #define NON_AMF_3GPP_ACCESS 2
 #define AMF_3GPP_ACCESS_AND_NON_AMF_3GPP_ACCESS 3
 
@@ -350,6 +350,8 @@ typedef struct amf_context_s {
   apn_config_profile_t apn_config_profile;
 
   amf_nas_message_decode_status_t decode_status;
+  nas5g_timer_t auth_retry_timer;
+  int auth_retry_count = 0;
 } amf_context_t;
 
 // Amf-Map Declarations:

lte/gateway/c/core/oai/tasks/amf/amf_authentication.cpp

@@ -100,8 +100,6 @@ static int start_authentication_information_procedure(
   OAILOG_FUNC_IN(LOG_NAS_AMF);
 
   int rc = RETURNerror;
-  char imsi_str[IMSI_BCD_DIGITS_MAX + 1];
-  uint8_t snni[40] = {0};
 
   amf_ue_ngap_id_t ue_id =
       PARENT_STRUCT(amf_context, ue_m5gmm_context_s, amf_context)
@@ -121,30 +119,61 @@ static int start_authentication_information_procedure(
   auth_info_proc->ue_id = ue_id;
   auth_info_proc->resync = auth_info_proc->request_sent;
 
-  bool is_initial_req = !(auth_info_proc->request_sent);
-  auth_info_proc->request_sent = true;
+  auth_proc->auts = auts;
+
+  rc = amf_authentication_request_sent(ue_id);
+  if (rc != RETURNok) {
+    OAILOG_FUNC_RETURN(LOG_NAS_AMF, rc);
+  }
 
+  OAILOG_FUNC_RETURN(LOG_NAS_AMF, RETURNok);
+}
+
+int amf_authentication_request_sent(amf_ue_ngap_id_t ue_id) {
+  ue_m5gmm_context_s* ue_mm_context = NULL;
+  amf_context_t* amf_context = NULL;
+  char imsi_str[IMSI_BCD_DIGITS_MAX + 1];
+  int rc = RETURNerror;
+  ue_mm_context = amf_ue_context_exists_amf_ue_ngap_id(ue_id);
+  uint8_t snni[40] = {0};
+  if (!ue_mm_context) {
+    OAILOG_WARNING(LOG_NAS_AMF,
+                   "AMF-PROC - Failed authentication request the UE due to NULL"
+                   "ue_context\n");
+    OAILOG_FUNC_RETURN(LOG_NAS_AMF, rc);
+  }
+  amf_context = &ue_mm_context->amf_context;
+  nas5g_amf_auth_proc_t* auth_proc =
+      get_nas5g_common_procedure_authentication(amf_context);
+
+  if (!auth_proc) {
+    OAILOG_WARNING(LOG_NAS_AMF, "authentication procedure not present\n");
+    OAILOG_FUNC_RETURN(LOG_NAS_AMF, rc);
+  }
   IMSI64_TO_STRING(amf_context->imsi64, imsi_str, IMSI_LENGTH);
 
   rc = calculate_amf_serving_network_name(amf_context, snni);
   if (rc != RETURNok) {
     OAILOG_FUNC_RETURN(LOG_NAS_AMF, rc);
   }
 
-  if (is_initial_req) {
+  nas5g_auth_info_proc_t* auth_info_proc =
+      get_nas5g_cn_procedure_auth_info(amf_context);
+  auth_info_proc->request_sent = true;
+  if (!auth_proc->auts) {
     OAILOG_INFO(LOG_AMF_APP,
                 "Sending msg(grpc) to :[subscriberdb] for ue: [%s] auth-info\n",
                 imsi_str);
     AMFClientServicer::getInstance().get_subs_auth_info(
         imsi_str, IMSI_LENGTH, reinterpret_cast<const char*>(snni), ue_id);
-  } else if (auts->data) {
+  } else if (auth_proc->auts) {
     OAILOG_INFO(
         LOG_AMF_APP,
         "Sending msg(grpc) to :[subscriberdb] for ue: [%s] auth-info-resync\n",
         imsi_str);
     AMFClientServicer::getInstance().get_subs_auth_info_resync(
-        imsi_str, IMSI_LENGTH, reinterpret_cast<const char*>(snni), auts->data,
-        RAND_LENGTH_OCTETS + AUTS_LENGTH, ue_id);
+        imsi_str, IMSI_LENGTH, reinterpret_cast<const char*>(snni),
+        auth_proc->auts->data, RAND_LENGTH_OCTETS + AUTS_LENGTH, ue_id);
   }
 
   OAILOG_FUNC_RETURN(LOG_NAS_AMF, RETURNok);

lte/gateway/c/core/oai/tasks/amf/amf_authentication.h

@@ -33,6 +33,7 @@ typedef struct nas5g_amf_auth_proc_s {
   int amf_cause;
   int retry_sync_failure;
 #define MAX_SYNC_FAILURES 2
+  const_bstring auts;
 } nas5g_amf_auth_proc_t;
 
 typedef struct nas5g_auth_info_proc_s {
@@ -77,7 +78,7 @@ int amf_send_authentication_request(amf_context_t* amf_context,
 
 // To be called when authentication is successful from subscriberdb
 int amf_authentication_proc_success(amf_context_t* amf_context);
-
+int amf_authentication_request_sent(amf_ue_ngap_id_t ue_id);
 int amf_nas_proc_authentication_info_answer(itti_amf_subs_auth_info_ans_t* aia);
 nas5g_amf_auth_proc_t* get_nas5g_common_procedure_authentication(
     const amf_context_t* const ctxt);

lte/gateway/c/core/oai/tasks/amf/amf_config.c

@@ -233,6 +233,17 @@ int amf_config_parse_file(amf_config_t* config_pP,
                                      (const char**)&astring)) {
       config_pP->default_dnn = bfromcstr(astring);
     }
+    // DEFAULT AUTH MAX RETRY COUNT
+    if (config_setting_lookup_string(
+            setting_amf, AUTHENTICATION_COUNTER_MAX_RETRY, &astring)) {
+      config_pP->auth_retry_max_count = (uint32_t)atoi(astring);
+    }
+
+    // DEFAULT AUTH RETRY TIMER EXPIRES MSECS
+    if (config_setting_lookup_string(
+            setting_amf, AUTHENTICATION_RETRY_TIMER_EXPIRY_MSECS, &astring)) {
+      config_pP->auth_retry_interval = (uint32_t)atoi(astring);
+    }
 
     // AMF_PLMN_SUPPORT SETTING
     setting = config_setting_get_member(setting_amf,

lte/gateway/c/core/oai/tasks/amf/nas_proc.cpp

@@ -42,6 +42,7 @@ extern task_zmq_ctx_s amf_app_task_zmq_ctx;
 AmfMsg amf_msg_obj;
 extern std::unordered_map<imsi64_t, guti_and_amf_id_t> amf_supi_guti_map;
 static int identification_t3570_handler(zloop_t* loop, int timer_id, void* arg);
+static int subs_auth_retry(zloop_t* loop, int timer_id, void* output);
 int nas_proc_establish_ind(const amf_ue_ngap_id_t ue_id,
                            const bool is_mm_ctx_new,
                            const tai_t originating_tai, const ecgi_t ecgi,
@@ -411,10 +412,54 @@ int amf_nas_proc_auth_param_res(amf_ue_ngap_id_t amf_ue_ngap_id,
   OAILOG_FUNC_RETURN(LOG_NAS_AMF, rc);
 }
 
+static int subs_auth_retry(zloop_t* loop, int timer_id, void* arg) {
+  amf_ue_ngap_id_t ue_id = 0;
+  amf_context_t* amf_ctxt_p = NULL;
+  int amf_cause = -1;
+  nas5g_auth_info_proc_t* auth_info_proc = NULL;
+  int rc = RETURNerror;
+  ue_m5gmm_context_s* ue_mm_context = NULL;
+  if (!amf_pop_timer_arg(timer_id, &ue_id)) {
+    OAILOG_WARNING(
+        LOG_AMF_APP,
+        "auth_retry_timer: Invalid Timer Id expiration, Timer Id: %d \n",
+        timer_id);
+    OAILOG_FUNC_RETURN(LOG_NAS_AMF, RETURNok);
+  }
+  ue_mm_context = amf_ue_context_exists_amf_ue_ngap_id(ue_id);
+  amf_ctxt_p = &ue_mm_context->amf_context;
+  if (amf_ctxt_p->auth_retry_count < amf_config.auth_retry_max_count) {
+    amf_ctxt_p->auth_retry_count++;
+    OAILOG_INFO(LOG_AMF_APP,
+                "auth_retry_timer: Incrementing auth_retry_count to %d\n",
+                amf_ctxt_p->auth_retry_count);
+    rc = amf_authentication_request_sent(ue_id);
+    amf_ctxt_p->auth_retry_timer.id =
+        amf_app_start_timer(amf_config.auth_retry_interval, TIMER_REPEAT_ONCE,
+                            subs_auth_retry, ue_id);
+  } else {
+    auth_info_proc = get_nas5g_cn_procedure_auth_info(amf_ctxt_p);
+    OAILOG_ERROR(
+        LOG_NAS_AMF,
+        "auth_retry_timer is expired . Authentication reject with cause "
+        "AMF_UE_ILLEGAL\n");
+    amf_cause = AMF_UE_ILLEGAL;
+
+    rc = amf_proc_registration_reject(ue_id, amf_cause);
+    if (auth_info_proc) {
+      nas5g_delete_cn_procedure(amf_ctxt_p, &auth_info_proc->cn_proc);
+    }
+
+    amf_free_ue_context(ue_mm_context);
+  }
+
+  return rc;
+}
+
 int amf_nas_proc_authentication_info_answer(
     itti_amf_subs_auth_info_ans_t* aia) {
   imsi64_t imsi64 = INVALID_IMSI64;
-  int rc = RETURNerror;
+  int rc = RETURNok;
   amf_context_t* amf_ctxt_p = NULL;
   ue_m5gmm_context_s* ue_5gmm_context_p = NULL;
   int amf_cause = -1;
@@ -444,8 +489,13 @@ int amf_nas_proc_authentication_info_answer(
       "Received Authentication Information Answer from Subscriberdb for"
       " UE ID = " AMF_UE_NGAP_ID_FMT,
       amf_ue_ngap_id);
-
   if (aia->auth_info.nb_of_vectors) {
+    if ((NAS5G_TIMER_INACTIVE_ID != amf_ctxt_p->auth_retry_timer.id) &&
+        (0 != amf_ctxt_p->auth_retry_timer.id)) {
+      OAILOG_DEBUG(LOG_NAS_AMF, "Stopping: Timer auth_retry_timer.\n");
+      amf_app_stop_timer(amf_ctxt_p->auth_retry_timer.id);
+      amf_ctxt_p->auth_retry_timer.id = NAS5G_TIMER_INACTIVE_ID;
+    }
     /*
      * Check that list is not empty and contain at most MAX_EPS_AUTH_VECTORS
      * elements
@@ -466,17 +516,32 @@ int amf_nas_proc_authentication_info_answer(
   } else {
     /* Get Auth Info Pro */
     auth_info_proc = get_nas5g_cn_procedure_auth_info(amf_ctxt_p);
-    OAILOG_ERROR(LOG_NAS_AMF,
-                 "result=%d, nb_of_vectors received is zero from subscriberdb",
-                 aia->result);
-    amf_cause = AMF_UE_ILLEGAL;
-    rc = amf_proc_registration_reject(amf_ue_ngap_id, amf_cause);
-    if (auth_info_proc) {
-      nas5g_delete_cn_procedure(amf_ctxt_p, &auth_info_proc->cn_proc);
+    amf_ctxt_p->auth_retry_count = 0;
+    if (aia->result != DIAMETER_TOO_BUSY) {
+      if ((NAS5G_TIMER_INACTIVE_ID != amf_ctxt_p->auth_retry_timer.id) &&
+          (0 != amf_ctxt_p->auth_retry_timer.id)) {
+        OAILOG_DEBUG(LOG_NAS_AMF, "Stopping: Timer auth_retry_timer.\n");
+        amf_app_stop_timer(amf_ctxt_p->auth_retry_timer.id);
+        amf_ctxt_p->auth_retry_timer.id = NAS5G_TIMER_INACTIVE_ID;
+      }
+      OAILOG_ERROR(
+          LOG_NAS_AMF,
+          "result=%d, nb_of_vectors received is zero from subscriberdb",
+          aia->result);
+      amf_cause = AMF_UE_ILLEGAL;
+      rc = amf_proc_registration_reject(amf_ue_ngap_id, amf_cause);
+      if (auth_info_proc) {
+        nas5g_delete_cn_procedure(amf_ctxt_p, &auth_info_proc->cn_proc);
+      }
+      amf_free_ue_context(ue_5gmm_context_p);
+      return rc;
+    } else {
+      amf_ctxt_p->auth_retry_timer.id =
+          amf_app_start_timer(amf_config.auth_retry_interval, TIMER_REPEAT_ONCE,
+                              subs_auth_retry, aia->ue_id);
+      rc = RETURNok;
     }
-    amf_free_ue_context(ue_5gmm_context_p);
   }
-
   OAILOG_FUNC_RETURN(LOG_NAS_AMF, rc);
 }
 

lte/gateway/c/core/oai/tasks/ngap/ngap_amf_decoder.c.orig

@@ -0,0 +1,47 @@
+/**
+ * Copyright 2020 The Magma Authors.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/****************************************************************************
+  Subsystem   Access and Mobility Management Function
+  Description Defines NG Application Protocol Messages
+*****************************************************************************/
+
+#include <stdbool.h>
+#include <string.h>
+
+#include "lte/gateway/c/core/oai/tasks/ngap/ngap_amf_decoder.h"
+#include "lte/gateway/c/core/oai/lib/bstr/bstrlib.h"
+#include "lte/gateway/c/core/oai/common/log.h"
+#include "lte/gateway/c/core/oai/common/assertions.h"
+#include "lte/gateway/c/core/oai/common/common_defs.h"
+#include "Ngap_NGAP-PDU.h"
+#include "Ngap_InitiatingMessage.h"
+#include "Ngap_ProcedureCode.h"
+#include "Ngap_SuccessfulOutcome.h"
+#include "Ngap_UnsuccessfulOutcome.h"
+#include "asn_codecs.h"
+#include "constr_TYPE.h"
+#include "per_decoder.h"
+
+int ngap_amf_decode_pdu(Ngap_NGAP_PDU_t* pdu, const_bstring const raw) {
+  asn_dec_rval_t dec_ret;
+  DevAssert(pdu != NULL);
+  DevAssert(blength(raw) != 0);
+  dec_ret = aper_decode(NULL, &asn_DEF_Ngap_NGAP_PDU, (void**)&pdu, bdata(raw),
+                        blength(raw), 0, 0);
+
+  if (dec_ret.code != RC_OK) {
+    OAILOG_ERROR(LOG_NGAP, "Failed to decode PDU\n");
+    return -1;
+  }
+  return 0;
+}

lte/gateway/c/core/oai/test/amf/test_amf_procedures.cpp

@@ -1292,4 +1292,39 @@ TEST_F(AMFAppProcedureTest, ServiceRequestMTWithPDU) {
 
   EXPECT_TRUE(expected_Ids == AMFClientServicer::getInstance().msgtype_stack);
 }
+
+TEST_F(AMFAppProcedureTest, TestAuthFailureFromSubscribeDbLock) {
+  amf_ue_ngap_id_t ue_id = 0;
+  amf_context_t* amf_ctxt_p = NULL;
+  nas5g_auth_info_proc_t* auth_info_proc = NULL;
+  ue_m5gmm_context_s* ue_context_p = nullptr;
+  std::vector<MessagesIds> expected_Ids{
+      AMF_APP_NGAP_AMF_UE_ID_NOTIFICATION,  // new registration notification
+                                            // indication to ngap
+      NGAP_NAS_DL_DATA_REQ,                 // Registration Reject
+      NGAP_UE_CONTEXT_RELEASE_COMMAND       // UEContextReleaseCommand
+  };
+
+  /* Send the initial UE message */
+  imsi64_t imsi64 = 0;
+  imsi64 = send_initial_ue_message_no_tmsi(amf_app_desc_p, 36, 1, 1, 0, plmn,
+                                           initial_ue_message_hexbuf,
+                                           sizeof(initial_ue_message_hexbuf));
+  /* Check if UE Context is created with correct imsi */
+  EXPECT_TRUE(get_ue_id_from_imsi(amf_app_desc_p, imsi64, &ue_id));
+
+  /* Send the authentication response message from subscriberdb */
+  itti_amf_subs_auth_info_ans_t aia_itti_msg = {};
+  strncpy(aia_itti_msg.imsi, imsi.c_str(), imsi.size());
+  aia_itti_msg.imsi_length = imsi.size();
+  aia_itti_msg.result = DIAMETER_TOO_BUSY;
+  int rc = RETURNerror;
+  rc = amf_nas_proc_authentication_info_answer(&aia_itti_msg);
+  EXPECT_TRUE(rc == RETURNok);
+  ue_context_p = amf_ue_context_exists_amf_ue_ngap_id(ue_id);
+  amf_ctxt_p = &ue_context_p->amf_context;
+  auth_info_proc = get_nas5g_cn_procedure_auth_info(amf_ctxt_p);
+  nas5g_delete_cn_procedure(amf_ctxt_p, &auth_info_proc->cn_proc);
+  amf_free_ue_context(ue_context_p);
+}
 }  // namespace magma5g

lte/gateway/configs/templates/mme.conf.template

@@ -343,6 +343,8 @@ AMF :
     DEFAULT_DNS_SEC_IPV4_ADDRESS = "{{ ipv4_sec_dns }}";
     AMF_NAME = "{{ amf_name }}";
     DEFAULT_DNN = "{{ default_dnn }}";
+    AUTHENTICATION_MAX_RETRY = "{{ auth_retry_max_count }}";
+    AUTHENTICATION_TIMER_EXPIRY = "{{ auth_retry_interval }}";
     PLMN_SUPPORT_LIST = (
        { MCC="{{ mcc }}" ; MNC="{{ mnc }}"; AMF_DEFAULT_SLICE_SERVICE_TYPE="{{ amf_default_slice_service_type }}" ; AMF_DEFAULT_SLICE_DIFFERENTIATOR="{{ amf_default_slice_differentiator }}"; }
     );