[SMF] Handle APCO IE in S2b GTPv2C CreateSessionRequest/Response

This IE is used by UEs registering through S2b interface (ePDG) to
obtain DNS and P-CSCF server address information.

lib/diameter/s6b/message.h

@@ -1,4 +1,4 @@
-/*
+/* 3GPP TS 29.273 section 9
  * Copyright (C) 2019 by Sukchan Lee <acetcom@gmail.com>
  *
  * This file is part of Open5GS.
@@ -35,7 +35,8 @@ extern struct dict_object *ogs_diam_s6b_application;
 extern struct dict_object *ogs_diam_s6b_mip6_feature_vector;
 
 typedef struct ogs_diam_s6b_message_s {
-#define OGS_DIAM_S6B_CMD_SESSION_TERMINATION                        1
+#define OGS_DIAM_S6B_CMD_AUTHENTICATION_AUTHORIZATION               1
+#define OGS_DIAM_S6B_CMD_SESSION_TERMINATION                        2
     uint16_t            cmd_code;
     uint32_t            result_code;
     uint32_t            *err;

src/smf/context.h

@@ -228,6 +228,8 @@ typedef struct smf_sess_s {
         uint32_t gx_cca_init_err; /* Gx CCA RXed error code */
         bool gy_ccr_init_in_flight; /* Waiting for Gy CCA */
         uint32_t gy_cca_init_err; /* Gy CCA RXed error code */
+        bool s6b_aar_in_flight; /* Waiting for S6B AAR */
+        uint32_t s6b_aaa_err; /* S6B AAA RXed error code */
         bool gx_ccr_term_in_flight; /* Waiting for Gx CCA */
         uint32_t gx_cca_term_err; /* Gx CCA RXed error code */
         bool gy_ccr_term_in_flight; /* Waiting for Gy CCA */
@@ -333,6 +335,7 @@ typedef struct smf_sess_s {
     struct {
         uint8_t version; /* GTPC version */
         ogs_tlv_octet_t ue_pco;
+        ogs_tlv_octet_t ue_apco;
         ogs_tlv_octet_t ue_epco;
         ogs_tlv_octet_t user_location_information;
         ogs_tlv_octet_t ue_timezone;

src/smf/gsm-sm.c

@@ -182,8 +182,10 @@ void smf_gsm_state_initial(ogs_fsm_t *s, smf_event_t *e)
     switch (e->h.id) {
     case OGS_FSM_ENTRY_SIG:
         /* reset state: */
+        sess->sm_data.s6b_aar_in_flight = false;
         sess->sm_data.gx_ccr_init_in_flight = false;
         sess->sm_data.gy_ccr_init_in_flight = false;
+        sess->sm_data.s6b_aaa_err = ER_DIAMETER_SUCCESS;
         sess->sm_data.gx_cca_init_err = ER_DIAMETER_SUCCESS;
         sess->sm_data.gy_cca_init_err = ER_DIAMETER_SUCCESS;
         break;
@@ -229,7 +231,9 @@ void smf_gsm_state_initial(ogs_fsm_t *s, smf_event_t *e)
                 break;
             case OGS_GTP2_RAT_TYPE_WLAN:
                 smf_s6b_send_aar(sess, e->gtp_xact);
+                sess->sm_data.s6b_aar_in_flight = true;
                 OGS_FSM_TRAN(s, smf_gsm_state_wait_epc_auth_initial);
+                /* Gx/Gy Init Req is done after s6b AAR + AAA */
                 break;
             default:
                 ogs_error("Unknown RAT Type [%d]", sess->gtp_rat_type);
@@ -327,6 +331,7 @@ void smf_gsm_state_wait_epc_auth_initial(ogs_fsm_t *s, smf_event_t *e)
 {
     smf_sess_t *sess = NULL;
 
+    ogs_diam_s6b_message_t *s6b_message = NULL;
     ogs_diam_gy_message_t *gy_message = NULL;
     ogs_diam_gx_message_t *gx_message = NULL;
     uint32_t diam_err;
@@ -340,6 +345,22 @@ void smf_gsm_state_wait_epc_auth_initial(ogs_fsm_t *s, smf_event_t *e)
     ogs_assert(sess);
 
     switch (e->h.id) {
+    case SMF_EVT_S6B_MESSAGE:
+        s6b_message = e->s6b_message;
+        ogs_assert(s6b_message);
+
+        switch(s6b_message->cmd_code) {
+        case OGS_DIAM_S6B_CMD_AUTHENTICATION_AUTHORIZATION:
+            sess->sm_data.s6b_aar_in_flight = false;
+            sess->sm_data.s6b_aaa_err = s6b_message->result_code;
+            if (s6b_message->result_code == ER_DIAMETER_SUCCESS) {
+                send_ccr_init_req_gx_gy(sess, e);
+                return;
+            }
+            goto test_can_proceed;
+        }
+        break;
+
     case SMF_EVT_GX_MESSAGE:
         gx_message = e->gx_message;
         ogs_assert(gx_message);
@@ -382,9 +403,12 @@ void smf_gsm_state_wait_epc_auth_initial(ogs_fsm_t *s, smf_event_t *e)
 
 test_can_proceed:
     /* First wait for both Gx and Gy requests to be done: */
-    if (!sess->sm_data.gx_ccr_init_in_flight &&
+    if (!sess->sm_data.s6b_aar_in_flight &&
+        !sess->sm_data.gx_ccr_init_in_flight &&
         !sess->sm_data.gy_ccr_init_in_flight) {
         diam_err = ER_DIAMETER_SUCCESS;
+        if (sess->sm_data.s6b_aaa_err != ER_DIAMETER_SUCCESS)
+            diam_err = sess->sm_data.s6b_aaa_err;
         if (sess->sm_data.gx_cca_init_err != ER_DIAMETER_SUCCESS)
             diam_err = sess->sm_data.gx_cca_init_err;
         if (sess->sm_data.gy_cca_init_err != ER_DIAMETER_SUCCESS)

src/smf/s5c-build.c

@@ -47,6 +47,8 @@ ogs_pkbuf_t *smf_s5c_build_create_session_response(
     int len;
     uint8_t pco_buf[OGS_MAX_PCO_LEN];
     int16_t pco_len;
+    uint8_t apco_buf[OGS_MAX_PCO_LEN];
+    int16_t apco_len;
     uint8_t *epco_buf = NULL;
     int16_t epco_len;
 
@@ -145,6 +147,17 @@ ogs_pkbuf_t *smf_s5c_build_create_session_response(
         rsp->protocol_configuration_options.len = pco_len;
     }
 
+    /* APCO */
+    if (sess->gtp.ue_apco.presence &&
+            sess->gtp.ue_apco.len && sess->gtp.ue_apco.data) {
+        apco_len = smf_pco_build(
+                apco_buf, sess->gtp.ue_apco.data, sess->gtp.ue_apco.len);
+        ogs_assert(apco_len > 0);
+        rsp->additional_protocol_configuration_options.presence = 1;
+        rsp->additional_protocol_configuration_options.data = apco_buf;
+        rsp->additional_protocol_configuration_options.len = apco_len;
+    }
+
     /* ePCO */
     if (sess->gtp.ue_epco.presence &&
             sess->gtp.ue_epco.len && sess->gtp.ue_epco.data) {

src/smf/s5c-handler.c

@@ -378,6 +378,12 @@ uint8_t smf_s5c_handle_create_session_request(
                 &req->protocol_configuration_options);
     }
 
+    /* APCO */
+    if (req->additional_protocol_configuration_options.presence) {
+        OGS_TLV_STORE_DATA(&sess->gtp.ue_apco,
+                &req->additional_protocol_configuration_options);
+    }
+
     /* Set User Location Information */
     if (req->user_location_information.presence) {
         OGS_TLV_STORE_DATA(&sess->gtp.user_location_information,
@@ -452,6 +458,8 @@ uint8_t smf_s5c_handle_delete_session_request(
         OGS_TLV_CLEAR_DATA(&sess->gtp.ue_pco);
     }
 
+    /* APCO not present in Session deletion procedure, hence no need to clear it here. */
+
     if (req->extended_protocol_configuration_options.presence) {
         OGS_TLV_STORE_DATA(&sess->gtp.ue_epco,
                 &req->extended_protocol_configuration_options);

src/smf/s6b-path.c

@@ -1,4 +1,4 @@
-/*
+/* 3GPP TS 29.273 section 9
  * Copyright (C) 2019 by Sukchan Lee <acetcom@gmail.com>
  *
  * This file is part of Open5GS.
@@ -344,11 +344,11 @@ static void smf_s6b_aaa_cb(void *data, struct msg **msg)
     unsigned long dur;
     int error = 0;
     int new;
-    int result_code = 0;
-    int exp_result_code = 0;
 
     smf_sess_t *sess = NULL;
     ogs_gtp_xact_t *xact = NULL;
+    smf_event_t *e = NULL;
+    ogs_diam_s6b_message_t *s6b_message = NULL;
 
     ogs_debug("[AA-Answer]");
 
@@ -374,15 +374,20 @@ static void smf_s6b_aaa_cb(void *data, struct msg **msg)
     xact = sess_data->xact;
     ogs_assert(xact);
 
+    s6b_message = ogs_calloc(1, sizeof(ogs_diam_s6b_message_t));
+    ogs_assert(s6b_message);
+    /* Set Session Termination Command */
+    s6b_message->cmd_code = OGS_DIAM_S6B_CMD_AUTHENTICATION_AUTHORIZATION;
+
     /* Value of Result Code */
     ret = fd_msg_search_avp(*msg, ogs_diam_result_code, &avp);
     ogs_assert(ret == 0);
     if (avp) {
         ret = fd_msg_avp_hdr(avp, &hdr);
         ogs_assert(ret == 0);
-        result_code = hdr->avp_value->i32;
-        if (result_code != ER_DIAMETER_SUCCESS) {
-            ogs_error("Result Code: %d", result_code);
+        s6b_message->result_code = hdr->avp_value->i32;
+        if (s6b_message->result_code != ER_DIAMETER_SUCCESS) {
+            ogs_error("Result Code: %d", s6b_message->result_code);
             error++;
         }
     } else {
@@ -397,8 +402,8 @@ static void smf_s6b_aaa_cb(void *data, struct msg **msg)
             if (avpch1) {
                 ret = fd_msg_avp_hdr(avpch1, &hdr);
                 ogs_assert(ret == 0);
-                exp_result_code = hdr->avp_value->i32;
-                ogs_error("Experimental Result Code: %d", exp_result_code);
+                s6b_message->result_code = hdr->avp_value->i32;
+                ogs_error("Experimental Result Code: %d", s6b_message->result_code);
             }
         } else {
             ogs_error("no Result-Code");
@@ -431,9 +436,22 @@ static void smf_s6b_aaa_cb(void *data, struct msg **msg)
         error++;
     }
 
-    if (!error) {
-        smf_gx_send_ccr(sess, xact,
-            OGS_DIAM_GX_CC_REQUEST_TYPE_INITIAL_REQUEST);
+    e = smf_event_new(SMF_EVT_S6B_MESSAGE);
+    ogs_assert(e);
+
+    if (error && s6b_message->result_code == ER_DIAMETER_SUCCESS)
+            s6b_message->result_code = error;
+
+    e->sess = sess;
+    e->gtp_xact = xact;
+    e->s6b_message = s6b_message;
+    ret = ogs_queue_push(ogs_app()->queue, e);
+    if (ret != OGS_OK) {
+        ogs_error("ogs_queue_push() failed:%d", (int)ret);
+        ogs_free(s6b_message);
+        ogs_event_free(e);
+    } else {
+        ogs_pollset_notify(ogs_app()->pollset);
     }
 
     /* Free the message */

src/smf/smf-sm.c

@@ -365,6 +365,7 @@ void smf_state_operational(ogs_fsm_t *s, smf_event_t *e)
         ogs_assert(sess);
 
         switch(s6b_message->cmd_code) {
+        case OGS_DIAM_S6B_CMD_AUTHENTICATION_AUTHORIZATION:
         case OGS_DIAM_S6B_CMD_SESSION_TERMINATION:
             ogs_fsm_dispatch(&sess->sm, e);
             break;