Merge remote-tracking branch 'origin/e1-patch-merge2' into integration_2022_wk39

executables/nr-softmodem.c

@@ -313,12 +313,12 @@ int create_gNB_tasks(uint32_t gnb_nb) {
     }
   }
 
-  if (AMF_MODE_ENABLED) {
+  if (get_softmodem_params()->sa) {
 
-   char*             gnb_ipv4_address_for_NGU      = NULL;
-   uint32_t          gnb_port_for_NGU              = 0;
-   char*             gnb_ipv4_address_for_S1U      = NULL;
-   uint32_t          gnb_port_for_S1U              = 0;
+    char*             gnb_ipv4_address_for_NGU      = NULL;
+    uint32_t          gnb_port_for_NGU              = 0;
+    char*             gnb_ipv4_address_for_S1U      = NULL;
+    uint32_t          gnb_port_for_S1U              = 0;
     paramdef_t NETParams[]  =  GNBNETPARAMS_DESC;
     char aprefix[MAX_OPTNAME_SIZE*2 + 8];
     sprintf(aprefix,"%s.[%i].%s",GNB_CONFIG_STRING_GNB_LIST,0,GNB_CONFIG_STRING_NETWORK_INTERFACES_CONFIG);
@@ -326,23 +326,17 @@ int create_gNB_tasks(uint32_t gnb_nb) {
     
     for(int i = GNB_INTERFACE_NAME_FOR_NG_AMF_IDX; i <= GNB_IPV4_ADDRESS_FOR_NG_AMF_IDX; i++) {
       if( NETParams[i].strptr == NULL) {
-	LOG_E(NGAP, "No configuration in the file.\n");
-	NGAP_CONF_MODE = 0;
+	LOG_E(NGAP, "No AMF configuration in the file.\n");
       } else {
 	LOG_D(NGAP, "Configuration in the file: %s.\n",*NETParams[i].strptr);
       }
     }
-
+    
     if (gnb_nb > 0) {
-      if(NGAP_CONF_MODE) {
-        if (itti_create_task (TASK_NGAP, ngap_gNB_task, NULL) < 0) {
-          LOG_E(NGAP, "Create task for NGAP failed\n");
-          return -1;
-        }
-      } else {
-        LOG_I(NGAP, "Ngap task not created\n");
+      if (itti_create_task (TASK_NGAP, ngap_gNB_task, NULL) < 0) {
+        LOG_E(NGAP, "Create task for NGAP failed\n");
+        return -1;
       }
-
     }
   }
 
@@ -359,8 +353,8 @@ int create_gNB_tasks(uint32_t gnb_nb) {
       return -1;
     }
 
-    //Use check on x2ap to consider the NSA scenario and check on AMF_MODE_ENABLED for the SA scenario
-    if(is_x2ap_enabled() || AMF_MODE_ENABLED) {
+    //Use check on x2ap to consider the NSA scenario and check for SA scenario
+    if(is_x2ap_enabled() || get_softmodem_params()->sa) {
       if (itti_create_task (TASK_GTPV1_U, &gtpv1uTask, NULL) < 0) {
         LOG_E(GTPU, "Create task for GTPV1U failed\n");
         return -1;
@@ -630,8 +624,6 @@ int main( int argc, char **argv ) {
   }
 
   openair0_cfg[0].threequarter_fs = threequarter_fs;
-  AMF_MODE_ENABLED = get_softmodem_params()->sa;
-  NGAP_CONF_MODE   = get_softmodem_params()->sa;
 
   if (get_softmodem_params()->do_ra)
     AssertFatal(get_softmodem_params()->phy_test == 0,"RA and phy_test are mutually exclusive\n");

openair1/SIMULATION/NR_PHY/nr_unitary_defs.h

@@ -63,7 +63,6 @@ void fill_scc_sim(NR_ServingCellConfigCommon_t *scc,uint64_t *ssb_bitmap,int N_R
 void fix_scc(NR_ServingCellConfigCommon_t *scc,uint64_t ssbmap);
 void prepare_scc(NR_ServingCellConfigCommon_t *scc);
 void prepare_scd(NR_ServingCellConfig_t *scd);
-ngap_gNB_config_t ngap_config;
 uint32_t ngap_generate_gNB_id(void) {return 0;}
 void configure_nfapi_pnf(char *vnf_ip_addr, int vnf_p5_port, char *pnf_ip_addr, int pnf_p7_port, int vnf_p7_port) { return;}
 void configure_nfapi_vnf(char *vnf_addr, int vnf_p5_port) { return;}

openair2/GNB_APP/gnb_app.c

@@ -88,7 +88,7 @@ static uint32_t gNB_app_register(uint32_t gnb_id_start, uint32_t gnb_id_end)//,
 
   for (gnb_id = gnb_id_start; (gnb_id < gnb_id_end) ; gnb_id++) {
     {
-      if(NGAP_CONF_MODE){
+      if(get_softmodem_params()->sa){
         ngap_register_gnb_req_t *ngap_register_gNB; //Type Temporarily reuse
           
         // note:  there is an implicit relationship between the data structure and the message name
@@ -187,7 +187,7 @@ void *gNB_app_task(void *args_p)
 
   /* For the CU case the gNB registration with the AMF might have to take place after the F1 setup, as the PLMN info
      * can originate from the DU. Add check on whether x2ap is enabled to account for ENDC NSA scenario.*/
-  if ((AMF_MODE_ENABLED || is_x2ap_enabled()) && !NODE_IS_DU(RC.nrrrc[0]->node_type) ) { //&& !NODE_IS_CU(RC.nrrrc[0]->node_type)) {
+  if ((get_softmodem_params()->sa || is_x2ap_enabled()) && !NODE_IS_DU(RC.nrrrc[0]->node_type) ) { //&& !NODE_IS_CU(RC.nrrrc[0]->node_type)) {
     /* Try to register each gNB */
     //registered_gnb = 0;
     __attribute__((unused)) uint32_t register_gnb_pending = gNB_app_register (gnb_id_start, gnb_id_end);

openair2/GNB_APP/gnb_config.c

@@ -34,6 +34,7 @@
 #include "common/utils/nr/nr_common.h"
 #include "common/utils/LOG/log_extern.h"
 #include "assertions.h"
+#include "executables/softmodem-common.h"
 #include "gnb_config.h"
 #include "gnb_paramdef.h"
 #include "enb_paramdef.h"
@@ -639,7 +640,7 @@ void RCconfig_nr_flexran()
     /* gNB ID from configuration, as read in by RCconfig_RRC() */
     if (!GNBParamList.paramarray[i][GNB_GNB_ID_IDX].uptr) {
       // Calculate a default gNB ID
-    if (AMF_MODE_ENABLED) 
+    if (get_softmodem_params()->sa) 
       gnb_id = i + (ngap_generate_gNB_id () & 0xFFFFFF8);
     else
       gnb_id = i;
@@ -1065,24 +1066,6 @@ void RCconfig_NRRRC(MessageDef *msg_p, uint32_t i, gNB_RRC_INST *rrc) {
   num_gnbs = GNBSParams[GNB_ACTIVE_GNBS_IDX].numelt;
   AssertFatal (i<num_gnbs,"Failed to parse config file no %ith element in %s \n",i, GNB_CONFIG_STRING_ACTIVE_GNBS);
 
-  /*
-  if (AMF_MODE_ENABLED) {
-    if (strcasecmp( *(GNBSParams[GNB_ASN1_VERBOSITY_IDX].strptr), GNB_CONFIG_STRING_ASN1_VERBOSITY_NONE) == 0) {
-      asn_debug      = 0;
-      asn1_xer_print = 0;
-    } else if (strcasecmp( *(GNBSParams[GNB_ASN1_VERBOSITY_IDX].strptr), GNB_CONFIG_STRING_ASN1_VERBOSITY_INFO) == 0) {
-      asn_debug      = 1;
-      asn1_xer_print = 1;
-    } else if (strcasecmp(*(GNBSParams[GNB_ASN1_VERBOSITY_IDX].strptr) , GNB_CONFIG_STRING_ASN1_VERBOSITY_ANNOYING) == 0) {
-      asn_debug      = 1;
-      asn1_xer_print = 2;
-    } else {
-      asn_debug      = 0;
-      asn1_xer_print = 0;
-    }
-  }
-  */
-
   if (num_gnbs>0) {
 
     // Output a list of all gNBs. ////////// Identification parameters
@@ -1090,7 +1073,7 @@ void RCconfig_NRRRC(MessageDef *msg_p, uint32_t i, gNB_RRC_INST *rrc) {
     
     if (GNBParamList.paramarray[i][GNB_GNB_ID_IDX].uptr == NULL) {
     // Calculate a default gNB ID
-      if (AMF_MODE_ENABLED) { 
+      if (get_softmodem_params()->sa) { 
         uint32_t hash;
         hash = ngap_generate_gNB_id ();
         gnb_id = i + (hash & 0xFFFFFF8);
@@ -1350,26 +1333,8 @@ int RCconfig_NR_NG(MessageDef *msg_p, uint32_t i) {
 
   /* get global parameters, defined outside any section in the config file */
   config_get( GNBSParams,sizeof(GNBSParams)/sizeof(paramdef_t),NULL); 
-
-  /*
-  if (AMF_MODE_ENABLED) {
-    if (strcasecmp( *(GNBSParams[GNB_ASN1_VERBOSITY_IDX].strptr), GNB_CONFIG_STRING_ASN1_VERBOSITY_NONE) == 0) {
-      asn_debug      = 0;
-      asn1_xer_print = 0;
-    } else if (strcasecmp( *(GNBSParams[GNB_ASN1_VERBOSITY_IDX].strptr), GNB_CONFIG_STRING_ASN1_VERBOSITY_INFO) == 0) {
-      asn_debug      = 1;
-      asn1_xer_print = 1;
-    } else if (strcasecmp(*(GNBSParams[GNB_ASN1_VERBOSITY_IDX].strptr) , GNB_CONFIG_STRING_ASN1_VERBOSITY_ANNOYING) == 0) {
-      asn_debug      = 1;
-      asn1_xer_print = 2;
-    } else {
-      asn_debug      = 0;
-      asn1_xer_print = 0;
-    }
-  }
-  */
   
-    AssertFatal (i<GNBSParams[GNB_ACTIVE_GNBS_IDX].numelt,
+  AssertFatal (i<GNBSParams[GNB_ACTIVE_GNBS_IDX].numelt,
      "Failed to parse config file %s, %uth attribute %s \n",
      RC.config_file_name, i, GNB_CONFIG_STRING_ACTIVE_GNBS);
     
@@ -1381,7 +1346,7 @@ int RCconfig_NR_NG(MessageDef *msg_p, uint32_t i) {
       for (k = 0; k < GNBParamList.numelt; k++) {
         if (GNBParamList.paramarray[k][GNB_GNB_ID_IDX].uptr == NULL) {
           // Calculate a default gNB ID
-          if (AMF_MODE_ENABLED) {
+          if (get_softmodem_params()->sa) {
             uint32_t hash;
           
           hash = ngap_generate_gNB_id ();
@@ -1537,7 +1502,7 @@ int RCconfig_NR_NG(MessageDef *msg_p, uint32_t i) {
             // SCTP SETTING
             NGAP_REGISTER_GNB_REQ (msg_p).sctp_out_streams = SCTP_OUT_STREAMS;
             NGAP_REGISTER_GNB_REQ (msg_p).sctp_in_streams  = SCTP_IN_STREAMS;
-            if (AMF_MODE_ENABLED) {
+            if (get_softmodem_params()->sa) {
               sprintf(aprefix,"%s.[%i].%s",GNB_CONFIG_STRING_GNB_LIST,k,GNB_CONFIG_STRING_SCTP_CONFIG);
               config_get( SCTPParams,sizeof(SCTPParams)/sizeof(paramdef_t),aprefix); 
               NGAP_REGISTER_GNB_REQ (msg_p).sctp_in_streams = (uint16_t)*(SCTPParams[GNB_SCTP_INSTREAMS_IDX].uptr);
@@ -1661,7 +1626,7 @@ int RCconfig_NR_X2(MessageDef *msg_p, uint32_t i) {
       for (k = 0; k < GNBParamList.numelt; k++) {
         if (GNBParamList.paramarray[k][GNB_GNB_ID_IDX].uptr == NULL) {
           // Calculate a default eNB ID
-          if (AMF_MODE_ENABLED) {
+          if (get_softmodem_params()->sa) {
             uint32_t hash;
             hash = ngap_generate_gNB_id ();
             gnb_id = k + (hash & 0xFFFFFF8);
@@ -1804,7 +1769,7 @@ int RCconfig_NR_X2(MessageDef *msg_p, uint32_t i) {
             X2AP_REGISTER_ENB_REQ (msg_p).sctp_out_streams = SCTP_OUT_STREAMS;
             X2AP_REGISTER_ENB_REQ (msg_p).sctp_in_streams  = SCTP_IN_STREAMS;
 
-            if (AMF_MODE_ENABLED) {
+            if (get_softmodem_params()->sa) {
               sprintf(aprefix,"%s.[%i].%s",GNB_CONFIG_STRING_GNB_LIST,k,GNB_CONFIG_STRING_SCTP_CONFIG);
               config_get( SCTPParams,sizeof(SCTPParams)/sizeof(paramdef_t),aprefix);
               X2AP_REGISTER_ENB_REQ (msg_p).sctp_in_streams = (uint16_t)*(SCTPParams[GNB_SCTP_INSTREAMS_IDX].uptr);

openair2/LAYER2/RLC/rlc.c

@@ -590,7 +590,7 @@ void rlc_data_ind     (
     T(T_ENB_RLC_UL, T_INT(ctxt_pP->module_id), T_INT(ctxt_pP->rnti), T_INT(rb_idP), T_INT(sdu_sizeP));
 #endif
     const ngran_node_t type = RC.rrc[ctxt_pP->module_id]->node_type;
-    AssertFatal(type != ngran_eNB_CU && type != ngran_ng_eNB_CU && type != ngran_gNB_CU,
+    AssertFatal(!NODE_IS_CU(type),
                 "Can't be CU, bad node type %d\n", type);
 
     if (NODE_IS_DU(type) && srb_flagP == 1) {

openair2/LAYER2/nr_rlc/nr_rlc_oai_api.c

@@ -514,7 +514,7 @@ rb_found:
       T_INT(ue->rnti), T_INT(rb_id), T_INT(size));
 
     const ngran_node_t type = RC.nrrrc[0 /*ctxt_pP->module_id*/]->node_type;
-    AssertFatal(type != ngran_eNB_CU && type != ngran_ng_eNB_CU && type != ngran_gNB_CU,
+    AssertFatal(!NODE_IS_CU(type),
                 "Can't be CU, bad node type %d\n", type);
 
     // if (NODE_IS_DU(type) && is_srb == 0) {

openair2/LAYER2/rlc_v2/rlc_oai_api.c

@@ -415,7 +415,7 @@ rb_found:
       T_INT(ue->rnti), T_INT(rb_id), T_INT(size));
 
     const ngran_node_t type = RC.rrc[0 /*ctxt_pP->module_id*/]->node_type;
-    AssertFatal(type != ngran_eNB_CU && type != ngran_ng_eNB_CU && type != ngran_gNB_CU,
+    AssertFatal(!NODE_IS_CU(type),
                 "Can't be CU, bad node type %d\n", type);
 
     if (NODE_IS_DU(type)) {

openair2/RRC/LTE/rrc_eNB_S1AP.c

@@ -1004,9 +1004,7 @@ int rrc_eNB_process_S1AP_INITIAL_CONTEXT_SETUP_REQ(MessageDef *msg_p, const char
     }
 
     
-    if ((RC.rrc[ctxt.module_id]->node_type == ngran_eNB_CU) ||
-	(RC.rrc[ctxt.module_id]->node_type == ngran_ng_eNB_CU) ||
-	(RC.rrc[ctxt.module_id]->node_type == ngran_gNB_CU) ){
+    if (NODE_IS_CU(RC.rrc[ctxt.module_id]->node_type)) {
       struct eNB_RRC_INST_s *rrc= RC.rrc[0];
       MessageDef *message_p = itti_alloc_new_message (TASK_RRC_ENB, 0, F1AP_UE_CONTEXT_SETUP_REQ);
       f1ap_ue_context_setup_t *req=&F1AP_UE_CONTEXT_SETUP_REQ (message_p);

openair2/RRC/NR/rrc_gNB.c

@@ -524,7 +524,7 @@ rrc_gNB_process_RRCSetupComplete(
   ue_context_pP->ue_context.Srb1.Srb_info.Srb_id = 1;
   ue_context_pP->ue_context.StatusRrc = NR_RRC_CONNECTED;
 
-  if (AMF_MODE_ENABLED) {
+  if (get_softmodem_params()->sa) {
     rrc_gNB_send_NGAP_NAS_FIRST_REQ(ctxt_pP, ue_context_pP, rrcSetupComplete);
   } else {
     rrc_gNB_generate_SecurityModeCommand(ctxt_pP, ue_context_pP);
@@ -1617,7 +1617,7 @@ rrc_gNB_process_RRCConnectionReestablishmentComplete(
   ue_context_pP->ue_context.Srb1.Active = 1;
   //ue_context_pP->ue_context.Srb2.Srb_info.Srb_id = 2;
 
-  if (AMF_MODE_ENABLED) {
+  if (get_softmodem_params()->sa) {
     hashtable_rc_t    h_rc;
     int               j;
     rrc_ue_ngap_ids_t *rrc_ue_ngap_ids_p = NULL;
@@ -1694,13 +1694,13 @@ rrc_gNB_process_RRCConnectionReestablishmentComplete(
       ue_context_pP->ue_context.ul_failure_timer = 0;
       return;
     }
-  } /* AMF_MODE_ENABLED */
+  } 
 
   /* Update RNTI in ue_context */
   ue_context_pP->ue_id_rnti                    = ctxt_pP->rnti; // here ue_id_rnti is just a key, may be something else
   ue_context_pP->ue_context.rnti               = ctxt_pP->rnti;
 
-  if (AMF_MODE_ENABLED) {
+  if (get_softmodem_params()->sa) {
     uint8_t send_security_mode_command = false;
     nr_rrc_pdcp_config_security(
       ctxt_pP,
@@ -2343,7 +2343,7 @@ rrc_gNB_decode_dcch(
                 ul_dcch_msg->message.choice.c1->choice.rrcReconfigurationComplete->rrc_TransactionIdentifier);
         }
 
-        if (AMF_MODE_ENABLED) {
+        if (get_softmodem_params()->sa) {
           if(ue_context_p->ue_context.pdu_session_release_command_flag == 1) {
             xid = ul_dcch_msg->message.choice.c1->choice.rrcReconfigurationComplete->rrc_TransactionIdentifier;
             ue_context_p->ue_context.pdu_session_release_command_flag = 0;
@@ -2476,7 +2476,7 @@ rrc_gNB_decode_dcch(
             LOG_DUMPMSG(RRC,DEBUG_RRC,(char *)Rx_sdu,sdu_sizeP,
                         "[MSG] RRC UL Information Transfer \n");
 
-            if (AMF_MODE_ENABLED == 1) {
+            if (get_softmodem_params()->sa) {
                 rrc_gNB_send_NGAP_UPLINK_NAS(ctxt_pP,
                                           ue_context_p,
                                           ul_dcch_msg);
@@ -2624,7 +2624,7 @@ rrc_gNB_decode_dcch(
           if(eutra_index == -1)
           break;
       }
-      if (AMF_MODE_ENABLED == 1) {
+      if (get_softmodem_params()->sa) {
           rrc_gNB_send_NGAP_UE_CAPABILITIES_IND(ctxt_pP,
                                     ue_context_p,
                                     ul_dcch_msg);

openair2/RRC/NR_UE/rrc_UE.c

@@ -152,7 +152,7 @@ static int nr_rrc_set_state (module_id_t ue_mod_idP, Rrc_State_NR_t state) {
 }
 
 static int nr_rrc_set_sub_state( module_id_t ue_mod_idP, Rrc_Sub_State_NR_t subState ) {
-  if (AMF_MODE_ENABLED) {
+  if (get_softmodem_params()->sa) {
     switch (NR_UE_rrc_inst[ue_mod_idP].nrRrcState) {
       case RRC_STATE_INACTIVE_NR:
         AssertFatal ((RRC_SUB_STATE_INACTIVE_FIRST_NR <= subState) && (subState <= RRC_SUB_STATE_INACTIVE_LAST_NR),
@@ -835,7 +835,7 @@ int nr_decode_SI( const protocol_ctxt_t *const ctxt_pP, const uint8_t gNB_index
 
           // After SI is received, prepare RRCConnectionRequest
           if (NR_UE_rrc_inst[ctxt_pP->module_id].MBMS_flag < 3) // see -Q option
-            if (AMF_MODE_ENABLED) {
+            if (get_softmodem_params()->sa) {
               nr_rrc_ue_generate_RRCSetupRequest( ctxt_pP->module_id, gNB_index );
             }
 
@@ -1341,20 +1341,16 @@ static void rrc_ue_generate_RRCSetupComplete(
   const char *nas_msg;
   int   nas_msg_length;
 
- if (AMF_MODE_ENABLED) {
-    if (get_softmodem_params()->sa) {
-      as_nas_info_t initialNasMsg;
-      generateRegistrationRequest(&initialNasMsg, ctxt_pP->module_id);
-      nas_msg = (char*)initialNasMsg.data;
-      nas_msg_length = initialNasMsg.length;
-    } else {
-      nas_msg         = (char *) NR_UE_rrc_inst[ctxt_pP->module_id].initialNasMsg.data;
-      nas_msg_length  = NR_UE_rrc_inst[ctxt_pP->module_id].initialNasMsg.length;
-    }
+  if (get_softmodem_params()->sa) {
+    as_nas_info_t initialNasMsg;
+    generateRegistrationRequest(&initialNasMsg, ctxt_pP->module_id);
+    nas_msg = (char*)initialNasMsg.data;
+    nas_msg_length = initialNasMsg.length;
   } else {
     nas_msg         = nr_nas_attach_req_imsi;
     nas_msg_length  = sizeof(nr_nas_attach_req_imsi);
   }
+
   size = do_RRCSetupComplete(ctxt_pP->module_id, buffer, sizeof(buffer),
                              Transaction_id, sel_plmn_id, nas_msg_length, nas_msg);
   LOG_I(NR_RRC,"[UE %d][RAPROC] Frame %d : Logical Channel UL-DCCH (SRB1), Generating RRCSetupComplete (bytes%d, gNB %d)\n",
@@ -1708,9 +1704,6 @@ int8_t nr_rrc_ue_decode_ccch( const protocol_ctxt_t *const ctxt_pP, const NR_SRB
  void nr_rrc_ue_generate_RRCSetupRequest(module_id_t module_id, const uint8_t gNB_index) {
    uint8_t i=0,rv[6];
 
-   if(get_softmodem_params()->sa) {
-     AMF_MODE_ENABLED = 1;
-   }
    if(NR_UE_rrc_inst[module_id].Srb0[gNB_index].Tx_buffer.payload_size ==0) {
      // Get RRCConnectionRequest, fill random for now
      // Generate random byte stream for contention resolution
@@ -1802,7 +1795,7 @@ nr_rrc_ue_establish_srb2(
    LOG_I(NR_RRC,"[UE %d] Frame %d: processing RRCReconfiguration: reconfiguring DRB %ld\n",
 	 ue_mod_idP, frameP, DRB_config->drb_Identity);
 
-  if(!AMF_MODE_ENABLED) {
+  if(!get_softmodem_params()->sa) {
     ip_addr_offset3 = 0;
     ip_addr_offset4 = 1;
     LOG_I(OIP, "[UE %d] trying to bring up the OAI interface %d, IP X.Y.%d.%d\n", ue_mod_idP, ip_addr_offset3+ue_mod_idP,

openair3/NGAP/ngap_gNB.c

@@ -64,8 +64,6 @@
   #include "oaisim_amf_test_s1c.h"
 #endif
 
-ngap_gNB_config_t ngap_config;
-
 static int ngap_gNB_generate_ng_setup_request(
   ngap_gNB_instance_t *instance_p, ngap_gNB_amf_data_t *ngap_amf_data_p);
 

openair3/NGAP/ngap_gNB.h

@@ -39,18 +39,6 @@
 #ifndef NGAP_GNB_H_
 #define NGAP_GNB_H_
 
-typedef struct ngap_gNB_config_s {
-  // MME related params
-  unsigned char amf_enabled;          ///< AMF enabled ?
-  unsigned char ngap_enabled;          ///< NGAP enabled ?
-} ngap_gNB_config_t;
-
-extern ngap_gNB_config_t ngap_config;
-
-#define AMF_MODE_ENABLED       ngap_config.amf_enabled
-#define NGAP_CONF_MODE         ngap_config.ngap_enabled
-
-
 void *ngap_gNB_process_itti_msg(void*);
 void  ngap_gNB_init(void);
 void *ngap_gNB_task(void *arg);