Added NAS identity request/response.

master
Pedro Alvarez 7 years ago
parent 4634d13a3b
commit 3984e1d9db

@ -51,6 +51,7 @@ public:
bool handle_nas_security_mode_complete(srslte::byte_buffer_t *nas_msg, ue_ctx_t *ue_ctx, srslte::byte_buffer_t *reply_buffer, bool *reply_flag);
bool handle_nas_attach_complete(srslte::byte_buffer_t *nas_msg, ue_ctx_t *ue_ctx, srslte::byte_buffer_t *reply_buffer, bool *reply_flag);
bool handle_esm_information_response(srslte::byte_buffer_t *nas_msg, ue_ctx_t* ue_ctx, srslte::byte_buffer_t *reply_msg, bool *reply_flag);
bool handle_identity_response(srslte::byte_buffer_t *nas_msg, ue_ctx_t* ue_ctx, srslte::byte_buffer_t *reply_msg, bool *reply_flag);
bool unpack_initial_ue_message(LIBLTE_S1AP_MESSAGE_INITIALUEMESSAGE_STRUCT *init_ue, LIBLTE_MME_ATTACH_REQUEST_MSG_STRUCT *attach_req, LIBLTE_MME_PDN_CONNECTIVITY_REQUEST_MSG_STRUCT *pdn_con_req);
@ -62,6 +63,7 @@ public:
bool pack_esm_information_request(srslte::byte_buffer_t *reply_msg, ue_ctx_t *ue_ctx);
bool pack_attach_accept(ue_ctx_t *ue_ctx, LIBLTE_S1AP_E_RABTOBESETUPITEMCTXTSUREQ_STRUCT *erab_ctxt, struct srslte::gtpc_pdn_address_allocation_ie *paa, srslte::byte_buffer_t *nas_buffer);
bool pack_identity_request(srslte::byte_buffer_t *reply_msg, uint32_t enb_ue_s1ap_id, uint32_t mme_ue_s1ap_id);
void log_unhandled_attach_request_ies(const LIBLTE_MME_ATTACH_REQUEST_MSG_STRUCT *attach_req);
void log_unhandled_pdn_con_request_ies(const LIBLTE_MME_PDN_CONNECTIVITY_REQUEST_MSG_STRUCT *pdn_con_req);

@ -106,7 +106,35 @@ s1ap_nas_transport::handle_initial_ue_message(LIBLTE_S1AP_MESSAGE_INITIALUEMESSA
return false;
}
//Create basic UE Ctx
ue_ctx.imsi = 0;
ue_ctx.mme_ue_s1ap_id = m_s1ap->get_next_mme_ue_s1ap_id();
//Get UE network capabilities
memcpy(&ue_ctx.ue_network_cap, &attach_req.ue_network_cap, sizeof(LIBLTE_MME_UE_NETWORK_CAPABILITY_STRUCT));
ue_ctx.ms_network_cap_present = attach_req.ms_network_cap_present;
if(attach_req.ms_network_cap_present)
{
memcpy(&ue_ctx.ms_network_cap, &attach_req.ms_network_cap, sizeof(LIBLTE_MME_MS_NETWORK_CAPABILITY_STRUCT));
}
uint8_t eps_bearer_id = pdn_con_req.eps_bearer_id; //TODO: Unused
ue_ctx.procedure_transaction_id = pdn_con_req.proc_transaction_id;
//Save whether ESM information transfer is necessary
ue_ctx.eit = pdn_con_req.esm_info_transfer_flag_present;
m_s1ap_log->console("EPS Bearer id: %d\n", eps_bearer_id);
//Initialize NAS count
ue_ctx.security_ctxt.ul_nas_count = 0;
ue_ctx.security_ctxt.dl_nas_count = 0;
//Add eNB info to UE ctxt
memcpy(&ue_ctx.enb_sri, enb_sri, sizeof(struct sctp_sndrcvinfo));
//Initialize E-RABs
for(uint i = 0 ; i< MAX_ERABS_PER_UE; i++)
{
ue_ctx.erabs_ctx[i].state = ERAB_DEACTIVATED;
ue_ctx.erabs_ctx[i].erab_id = i;
}
//Get UE Identity
if(attach_req.eps_mobile_id.type_of_id == LIBLTE_MME_EPS_MOBILE_ID_TYPE_IMSI)
{
//IMSI style attach
@ -125,8 +153,12 @@ s1ap_nas_transport::handle_initial_ue_message(LIBLTE_S1AP_MESSAGE_INITIALUEMESSA
if(it == m_s1ap->m_tmsi_to_s1ap_id.end())
{
//FIXME Send Id request
m_s1ap_log->console("Could not find M-TMSI in attach request\n");
return false;
m_s1ap_log->console("Could not find M-TMSI in attach request. Sending ID request\n");
m_s1ap_log->info("Could not find M-TMSI in attach request. Sending Id Request\n");
m_s1ap->add_new_ue_ctx(ue_ctx);
pack_identity_request(reply_buffer, ue_ctx.mme_ue_s1ap_id, ue_ctx.enb_ue_s1ap_id);
*reply_flag = true;
return true;
}
m_s1ap_log->console("Found M-TMSI: %d\n",m_tmsi);
ue_ctx_t *tmp = m_s1ap->find_ue_ctx(it->second);
@ -139,27 +171,7 @@ s1ap_nas_transport::handle_initial_ue_message(LIBLTE_S1AP_MESSAGE_INITIALUEMESSA
m_s1ap_log->console("Attach request from IMSI: %015lu\n", imsi);
m_s1ap_log->info("Attach request from IMSI: %015lu\n", imsi);
//Get UE network capabilities
memcpy(&ue_ctx.ue_network_cap, &attach_req.ue_network_cap, sizeof(LIBLTE_MME_UE_NETWORK_CAPABILITY_STRUCT));
ue_ctx.ms_network_cap_present = attach_req.ms_network_cap_present;
if(attach_req.ms_network_cap_present)
{
memcpy(&ue_ctx.ms_network_cap, &attach_req.ms_network_cap, sizeof(LIBLTE_MME_MS_NETWORK_CAPABILITY_STRUCT));
}
//FIXME use this info
uint8_t eps_bearer_id = pdn_con_req.eps_bearer_id; //TODO: Unused
ue_ctx.procedure_transaction_id = pdn_con_req.proc_transaction_id;
//Save whether ESM information transfer is necessary
ue_ctx.eit = pdn_con_req.esm_info_transfer_flag_present;
m_s1ap_log->console("EPS Bearer id: %d\n", eps_bearer_id);
//Initialize NAS count
ue_ctx.security_ctxt.ul_nas_count = 0;
ue_ctx.security_ctxt.dl_nas_count = 0;
//Add eNB info to UE ctxt
memcpy(&ue_ctx.enb_sri, enb_sri, sizeof(struct sctp_sndrcvinfo));
//Get Authentication Vectors from HSS
if(!m_hss->gen_auth_info_answer(imsi, ue_ctx.security_ctxt.k_asme, autn, rand, ue_ctx.security_ctxt.xres))
{
@ -172,12 +184,6 @@ s1ap_nas_transport::handle_initial_ue_message(LIBLTE_S1AP_MESSAGE_INITIALUEMESSA
ue_ctx.imsi = imsi;
ue_ctx.mme_ue_s1ap_id = m_s1ap->get_next_mme_ue_s1ap_id();
for(uint i = 0 ; i< MAX_ERABS_PER_UE; i++)
{
ue_ctx.erabs_ctx[i].state = ERAB_DEACTIVATED;
ue_ctx.erabs_ctx[i].erab_id = i;
}
if(attach_req.eps_mobile_id.type_of_id == LIBLTE_MME_EPS_MOBILE_ID_TYPE_IMSI)
{
//IMSI attach requeires new UE ctxt
@ -244,6 +250,11 @@ s1ap_nas_transport::handle_uplink_nas_transport(LIBLTE_S1AP_MESSAGE_UPLINKNASTRA
handle_esm_information_response(nas_msg, ue_ctx, reply_buffer, reply_flag);
ue_ctx->security_ctxt.ul_nas_count++;
return true;
case LIBLTE_MME_MSG_TYPE_IDENTITY_RESPONSE:
m_s1ap_log->info("UL NAS: Received ID Response\n");
handle_identity_response(nas_msg, ue_ctx, reply_buffer, reply_flag);
//ue_ctx->security_ctxt.ul_nas_count++;
return true;
default:
m_s1ap_log->warning("Unhandled NAS message 0x%x\n", msg_type );
m_s1ap_log->console("Unhandled NAS message 0x%x\n", msg_type );
@ -407,7 +418,47 @@ s1ap_nas_transport::handle_esm_information_response(srslte::byte_buffer_t *nas_m
return true;
}
bool
s1ap_nas_transport::handle_identity_response(srslte::byte_buffer_t *nas_msg, ue_ctx_t* ue_ctx, srslte::byte_buffer_t *reply_msg, bool *reply_flag)
{
uint8_t autn[16];
uint8_t rand[6];
uint8_t xres[8];
LIBLTE_MME_ID_RESPONSE_MSG_STRUCT id_resp;
LIBLTE_ERROR_ENUM err = liblte_mme_unpack_identity_response_msg((LIBLTE_BYTE_MSG_STRUCT *) nas_msg, &id_resp);
if(err != LIBLTE_SUCCESS){
m_s1ap_log->error("Error unpacking NAS authentication response. Error: %s\n", liblte_error_text[err]);
return false;
}
uint64_t imsi = 0;
for(int i=0;i<=14;i++){
imsi += id_resp.mobile_id.imsi[i]*std::pow(10,14-i);
}
m_s1ap_log->info("Id Response IMSI: %015lu\n", imsi);
ue_ctx->imsi = imsi;
//Get Authentication Vectors from HSS
if(!m_hss->gen_auth_info_answer(imsi, ue_ctx->security_ctxt.k_asme, autn, rand, ue_ctx->security_ctxt.xres))
{
m_s1ap_log->console("User not found. IMSI %015lu\n",imsi);
m_s1ap_log->info("User not found. IMSI %015lu\n",imsi);
return false;
}
//Pack NAS Authentication Request in Downlink NAS Transport msg
pack_authentication_request(reply_msg, ue_ctx->enb_ue_s1ap_id, ue_ctx->mme_ue_s1ap_id, autn, rand);
//Send reply to eNB
*reply_flag = true;
m_s1ap_log->info("DL NAS: Sent Athentication Request\n");
//TODO Start T3460 Timer!
return true;
return true;
}
/*Packing/Unpacking helper functions*/
bool
s1ap_nas_transport::unpack_initial_ue_message(LIBLTE_S1AP_MESSAGE_INITIALUEMESSAGE_STRUCT *init_ue,
@ -870,7 +921,56 @@ s1ap_nas_transport::pack_attach_accept(ue_ctx_t *ue_ctx, LIBLTE_S1AP_E_RABTOBESE
return true;
}
bool
s1ap_nas_transport::pack_identity_request(srslte::byte_buffer_t *reply_msg, uint32_t enb_ue_s1ap_id, uint32_t mme_ue_s1ap_id)
{
srslte::byte_buffer_t *nas_buffer = m_pool->allocate();
//Setup initiating message
LIBLTE_S1AP_S1AP_PDU_STRUCT tx_pdu;
bzero(&tx_pdu, sizeof(LIBLTE_S1AP_S1AP_PDU_STRUCT));
tx_pdu.ext = false;
tx_pdu.choice_type = LIBLTE_S1AP_S1AP_PDU_CHOICE_INITIATINGMESSAGE;
LIBLTE_S1AP_INITIATINGMESSAGE_STRUCT *init = &tx_pdu.choice.initiatingMessage;
init->procedureCode = LIBLTE_S1AP_PROC_ID_DOWNLINKNASTRANSPORT;
init->choice_type = LIBLTE_S1AP_INITIATINGMESSAGE_CHOICE_DOWNLINKNASTRANSPORT;
//Setup Dw NAS structure
LIBLTE_S1AP_MESSAGE_DOWNLINKNASTRANSPORT_STRUCT *dw_nas = &init->choice.DownlinkNASTransport;
dw_nas->ext=false;
dw_nas->MME_UE_S1AP_ID.MME_UE_S1AP_ID = mme_ue_s1ap_id;//FIXME Change name
dw_nas->eNB_UE_S1AP_ID.ENB_UE_S1AP_ID = enb_ue_s1ap_id;
dw_nas->HandoverRestrictionList_present=false;
dw_nas->SubscriberProfileIDforRFP_present=false;
LIBLTE_MME_ID_REQUEST_MSG_STRUCT id_req;
id_req.id_type = LIBLTE_MME_EPS_MOBILE_ID_TYPE_IMSI;
LIBLTE_ERROR_ENUM err = liblte_mme_pack_identity_request_msg(&id_req, (LIBLTE_BYTE_MSG_STRUCT *) nas_buffer);
if(err != LIBLTE_SUCCESS)
{
m_s1ap_log->error("Error packing Identity Request\n");
m_s1ap_log->console("Error packing Identity REquest\n");
return false;
}
//Copy NAS PDU to Downlink NAS Trasport message buffer
memcpy(dw_nas->NAS_PDU.buffer, nas_buffer->msg, nas_buffer->N_bytes);
dw_nas->NAS_PDU.n_octets = nas_buffer->N_bytes;
//Pack Downlink NAS Transport Message
err = liblte_s1ap_pack_s1ap_pdu(&tx_pdu, (LIBLTE_BYTE_MSG_STRUCT *) reply_msg);
if(err != LIBLTE_SUCCESS)
{
m_s1ap_log->error("Error packing Dw NAS Transport: Athentication Reject\n");
m_s1ap_log->console("Error packing Downlink NAS Transport: Athentication Reject\n");
return false;
}
m_pool->deallocate(nas_buffer);
return true;
}
/*Helper functions*/
void

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