From 2392f23d7f829c9e2ca9ce95bd9c0471967f888f Mon Sep 17 00:00:00 2001
From: Sukchan Lee <acetcom@gmail.com>
Date: Wed, 16 Dec 2020 22:44:32 -0500
Subject: [PATCH] fix: the unexpected PDN type error (#721)

---
 lib/core/ogs-3gpp-types.h |  6 ++++++
 src/mme/esm-build.c       |  4 ++--
 src/mme/esm-handler.c     | 20 ++------------------
 src/mme/mme-s11-handler.c | 15 +++++++++++++++
 4 files changed, 25 insertions(+), 20 deletions(-)

diff --git a/lib/core/ogs-3gpp-types.h b/lib/core/ogs-3gpp-types.h
index 88a3501a7..89dd2cd62 100644
--- a/lib/core/ogs-3gpp-types.h
+++ b/lib/core/ogs-3gpp-types.h
@@ -228,6 +228,12 @@ ED2(uint8_t spare:5;,
 #define OGS_PFCP_PDN_TYPE_IPV6                  OGS_PDU_SESSION_TYPE_IPV6
 #define OGS_PFCP_PDN_TYPE_IPV4V6                OGS_PDU_SESSION_TYPE_IPV4V6
 #define OGS_PFCP_PDN_TYPE_NONIP                 OGS_PDU_SESSION_TYPE_NONIP
+
+#define OGS_GTP_PDN_TYPE_IS_VALID(x) \
+        ((x) == OGS_GTP_PDN_TYPE_IPV4 || \
+         (x) == OGS_GTP_PDN_TYPE_IPV6 || \
+         (x) == OGS_GTP_PDN_TYPE_IPV4V6) \
+
     uint8_t pdn_type:3;)
     union {
         /* GTP_PDN_TYPE_IPV4 */
diff --git a/src/mme/esm-build.c b/src/mme/esm-build.c
index b1e50b913..97ef477a7 100644
--- a/src/mme/esm-build.c
+++ b/src/mme/esm-build.c
@@ -213,8 +213,8 @@ ogs_pkbuf_t *esm_build_activate_default_bearer_context_request(
         pdn_address->length = OGS_NAS_PDU_ADDRESS_IPV4V6_LEN;
         ogs_debug("    IPv4v6");
     } else {
-        ogs_error("Unexpected PDN Type %u", pdn_address->pdn_type);
-        return NULL;
+        ogs_fatal("Unexpected PDN Type %u", pdn_address->pdn_type);
+        ogs_assert_if_reached();
     }
 
     if (pdn->ambr.downlink || pdn->ambr.uplink) {
diff --git a/src/mme/esm-handler.c b/src/mme/esm-handler.c
index 5a4771f1b..fd2ce84a4 100644
--- a/src/mme/esm-handler.c
+++ b/src/mme/esm-handler.c
@@ -148,30 +148,14 @@ int esm_handle_information_response(mme_sess_t *sess,
     if (sess->pdn) {
         ogs_debug("    APN[%s]", sess->pdn->apn);
 
-        if (SESSION_CONTEXT_IS_AVAILABLE(mme_ue)) {
+        if (SESSION_CONTEXT_IS_AVAILABLE(mme_ue) &&
+            OGS_GTP_PDN_TYPE_IS_VALID(sess->pdn->paa.pdn_type)) {
             mme_csmap_t *csmap = mme_csmap_find_by_tai(&mme_ue->tai);
             mme_ue->csmap = csmap;
 
             if (csmap) {
                 sgsap_send_location_update_request(mme_ue);
             } else {
-
-                if (sess->pdn->paa.pdn_type == OGS_GTP_PDN_TYPE_IPV4) {
-                    /* Nothing */
-                } else if (sess->pdn->paa.pdn_type == OGS_GTP_PDN_TYPE_IPV6) {
-                    /* Nothing */
-                } else if (sess->pdn->paa.pdn_type == OGS_GTP_PDN_TYPE_IPV4V6) {
-                    /* Nothing */
-                } else {
-                    ogs_error("Unknown PDN[%s] Type %u:%u",
-                            sess->pdn->apn,
-                            sess->pdn->pdn_type,
-                            sess->pdn->paa.pdn_type);
-                    nas_eps_send_pdn_connectivity_reject(
-                            sess, ESM_CAUSE_UNKNOWN_PDN_TYPE);
-                    return OGS_ERROR;
-                }
-
                 nas_eps_send_attach_accept(mme_ue);
             }
         } else {
diff --git a/src/mme/mme-s11-handler.c b/src/mme/mme-s11-handler.c
index 0d5c77c48..ac19d78a3 100644
--- a/src/mme/mme-s11-handler.c
+++ b/src/mme/mme-s11-handler.c
@@ -126,6 +126,18 @@ void mme_s11_handle_create_session_response(
         cause_value = OGS_GTP_CAUSE_MANDATORY_IE_MISSING;
     }
 
+    if (rsp->pdn_address_allocation.presence) {
+        ogs_paa_t paa;
+
+        memcpy(&paa, rsp->pdn_address_allocation.data,
+                rsp->pdn_address_allocation.len);
+
+        if (!OGS_GTP_PDN_TYPE_IS_VALID(paa.pdn_type)) {
+            ogs_error("Unknown PDN Type[%u]", paa.pdn_type);
+            cause_value = OGS_GTP_CAUSE_MANDATORY_IE_INCORRECT;
+        }
+    }
+
     if (cause_value != OGS_GTP_CAUSE_REQUEST_ACCEPTED) {
         if (sess && SESSION_CONTEXT_IN_ATTACH(sess)) {
             ogs_error("[%s] Attach reject", mme_ue->imsi_bcd);
@@ -195,12 +207,15 @@ void mme_s11_handle_create_session_response(
         mme_ue->csmap = csmap;
 
         if (csmap) {
+            ogs_assert(OGS_GTP_PDN_TYPE_IS_VALID(pdn->paa.pdn_type));
             sgsap_send_location_update_request(mme_ue);
         } else {
+            ogs_assert(OGS_GTP_PDN_TYPE_IS_VALID(pdn->paa.pdn_type));
             nas_eps_send_attach_accept(mme_ue);
         }
 
     } else {
+        ogs_assert(OGS_GTP_PDN_TYPE_IS_VALID(pdn->paa.pdn_type));
         nas_eps_send_activate_default_bearer_context_request(bearer);
     }
 }