[SMF/UPF] Clarify FALLBACK SUBNET [#1128]

configs/open5gs/smf.yaml.in

@@ -122,6 +122,7 @@ logger:
 #
 #
 #  o Specific DNN/APN(e.g 'ims') uses 10.46.0.1/16, 2001:230:babe::1/48
+#    ; If the UE has unknown DNN/APN(not internet/ims), SMF/UPF will crash.
 #
 #    subnet:
 #      - addr: 10.45.0.1/16
@@ -133,6 +134,16 @@ logger:
 #      - addr: 2001:230:babe::1/48
 #        dnn: ims
 #
+#  o Specific DNN/APN with the FALLBACK SUBNET(10.47.0.1/16)
+#    ; Note that put the FALLBACK SUBNET last to avoid SMF/UPF crash.
+#
+#    subnet:
+#      - addr: 10.45.0.1/16
+#        dnn: internet
+#      - addr: 10.46.0.1/16
+#        dnn: ims
+#      - addr: 10.50.0.1/16 ## FALLBACK SUBNET
+#
 #  o Pool Range Sample
 #    subnet:
 #      - addr: 10.45.0.1/24

configs/open5gs/upf.yaml.in

@@ -107,6 +107,8 @@ logger:
 #    $ sudo ip addr add 2001:230:cafe::1/48 dev ogstun
 #    $ sudo ip addr add 2001:230:babe::1/48 dev ogstun
 #
+#    ; If the UE has unknown DNN/APN(not internet/ims), SMF/UPF will crash.
+#
 #    subnet:
 #      - addr: 10.45.0.1/16
 #        dnn: internet
@@ -117,6 +119,16 @@ logger:
 #      - addr: 2001:230:babe::1/48
 #        dnn: ims
 #
+#  o Specific DNN/APN with the FALLBACK SUBNET(10.47.0.1/16)
+#    ; Note that put the FALLBACK SUBNET last to avoid SMF/UPF crash.
+#
+#    subnet:
+#      - addr: 10.45.0.1/16
+#        dnn: internet
+#      - addr: 10.46.0.1/16
+#        dnn: ims
+#      - addr: 10.50.0.1/16 ## FALLBACK SUBNET
+#
 #  o Multiple Devices (default: ogstun)
 #    $ sudo ip addr add 10.45.0.1/16 dev ogstun
 #    $ sudo ip addr add 2001:230:cafe::1/48 dev ogstun2

lib/pfcp/context.c

@@ -1572,7 +1572,7 @@ int ogs_pfcp_ue_pool_generate(void)
 }
 
 ogs_pfcp_ue_ip_t *ogs_pfcp_ue_ip_alloc(
-        int family, const char *dnn, uint8_t *addr)
+        uint8_t *cause_value, int family, const char *dnn, uint8_t *addr)
 {
     ogs_pfcp_subnet_t *subnet = NULL;
     ogs_pfcp_ue_ip_t *ue_ip = NULL;
@@ -1587,6 +1587,7 @@ ogs_pfcp_ue_ip_t *ogs_pfcp_ue_ip_alloc(
         maxbytes = 16;
     } else {
         ogs_error("Invalid family[%d]", family);
+        ogs_assert_if_reached();
         return NULL;
     }
 
@@ -1598,27 +1599,36 @@ ogs_pfcp_ue_ip_t *ogs_pfcp_ue_ip_alloc(
     if (subnet == NULL) {
         ogs_error("CHECK CONFIGURATION: Cannot find subnet [family:%d, dnn:%s]",
                     family, dnn ? dnn : "No DNN");
-        ogs_error("smf");
+        ogs_error("Please add FALLBACK subnet as below.");
         ogs_error("    subnet:");
         if (family == AF_INET)
-            ogs_error("     - addr: 10.45.0.1/16");
+            ogs_error("     - addr: 10.50.0.1/16");
         else if (family == AF_INET6)
-            ogs_error("     - addr: 2001:230:cafe::1/48");
+            ogs_error("     - addr: 2001:230:abcd::1/48");
 
+        *cause_value = OGS_PFCP_CAUSE_SYSTEM_FAILURE;
         return NULL;
     }
 
     /* if assigning a static IP, do so. If not, assign dynamically! */
     if (memcmp(addr, zero, maxbytes) != 0) {
         ue_ip = ogs_calloc(1, sizeof(ogs_pfcp_ue_ip_t));
-        ogs_expect_or_return_val(ue_ip, NULL);
+        if (!ue_ip) {
+            ogs_error("All dynamic addresses are occupied");
+            *cause_value = OGS_PFCP_CAUSE_ALL_DYNAMIC_ADDRESS_ARE_OCCUPIED;
+            return NULL;
+        }
 
         ue_ip->subnet = subnet;
         ue_ip->static_ip = true;
         memcpy(ue_ip->addr, addr, maxbytes);
     } else {
         ogs_pool_alloc(&subnet->pool, &ue_ip);
-        ogs_expect(ue_ip);
+        if (!ue_ip) {
+            ogs_error("No resources avaiable");
+            *cause_value = OGS_PFCP_CAUSE_NO_RESOURCES_AVAILABLE;
+            return NULL;
+        }
     }
 
     return ue_ip;

lib/pfcp/context.h

@@ -421,7 +421,7 @@ void ogs_pfcp_rule_remove_all(ogs_pfcp_pdr_t *pdr);
 
 int ogs_pfcp_ue_pool_generate(void);
 ogs_pfcp_ue_ip_t *ogs_pfcp_ue_ip_alloc(
-        int family, const char *dnn, uint8_t *addr);
+        uint8_t *cause_value, int family, const char *dnn, uint8_t *addr);
 void ogs_pfcp_ue_ip_free(ogs_pfcp_ue_ip_t *ip);
 
 ogs_pfcp_dev_t *ogs_pfcp_dev_add(const char *ifname);

lib/pfcp/types.h

@@ -37,6 +37,7 @@ typedef uint32_t ogs_pfcp_qer_id_t;
 typedef uint8_t  ogs_pfcp_bar_id_t;
 
 #define OGS_PFCP_CAUSE_REQUEST_ACCEPTED                     1
+#define OGS_PFCP_CAUSE_MORE_USAGE_REPORT_TO_SEND            2
 #define OGS_PFCP_CAUSE_REQUEST_REJECTED                     64
 #define OGS_PFCP_CAUSE_SESSION_CONTEXT_NOT_FOUND            65
 #define OGS_PFCP_CAUSE_MANDATORY_IE_MISSING                 66
@@ -51,6 +52,8 @@ typedef uint8_t  ogs_pfcp_bar_id_t;
 #define OGS_PFCP_CAUSE_NO_RESOURCES_AVAILABLE               75
 #define OGS_PFCP_CAUSE_SERVICE_NOT_SUPPORTED                76
 #define OGS_PFCP_CAUSE_SYSTEM_FAILURE                       77
+#define OGS_PFCP_CAUSE_REDIRECTION_REQUESTED                78
+#define OGS_PFCP_CAUSE_ALL_DYNAMIC_ADDRESS_ARE_OCCUPIED     79
 
 const char *ogs_pfcp_cause_get_name(uint8_t cause);
 

src/mme/mme-context.c

@@ -2698,6 +2698,12 @@ mme_sess_t *mme_sess_next(mme_sess_t *sess)
     return ogs_list_next(sess);
 }
 
+bool mme_ue_in_attach(mme_ue_t *mme_ue)
+{
+    ogs_assert(mme_ue);
+    return (ogs_list_count(&mme_ue->sess_list) <= 1);
+}
+
 bool mme_sess_in_attach(mme_sess_t *sess)
 {
     mme_ue_t *mme_ue = NULL;
@@ -2706,7 +2712,7 @@ bool mme_sess_in_attach(mme_sess_t *sess)
     mme_ue = sess->mme_ue;
     ogs_assert(mme_ue);
 
-    return (ogs_list_count(&mme_ue->sess_list) <= 1);
+    return mme_ue_in_attach(mme_ue);
 }
 
 unsigned int mme_sess_count(mme_ue_t *mme_ue)

src/mme/mme-context.h

@@ -778,7 +778,9 @@ mme_sess_t *mme_sess_first(mme_ue_t *mme_ue);
 mme_sess_t *mme_sess_next(mme_sess_t *sess);
 unsigned int mme_sess_count(mme_ue_t *mme_ue);
 
+#define UE_CONTEXT_IN_ATTACH(__mME) mme_ue_in_attach(__mME)
 #define SESSION_CONTEXT_IN_ATTACH(__sESS) mme_sess_in_attach(__sESS)
+bool mme_ue_in_attach(mme_ue_t *mme_ue);
 bool mme_sess_in_attach(mme_sess_t *sess);
 
 mme_bearer_t *mme_bearer_add(mme_sess_t *sess);

src/mme/mme-s11-handler.c

@@ -166,7 +166,7 @@ void mme_s11_handle_create_session_response(
     }
 
     if (cause_value != OGS_GTP_CAUSE_REQUEST_ACCEPTED) {
-        if (sess && SESSION_CONTEXT_IN_ATTACH(sess)) {
+        if (mme_ue && UE_CONTEXT_IN_ATTACH(mme_ue)) {
             ogs_error("[%s] Attach reject", mme_ue->imsi_bcd);
             ogs_assert(OGS_OK ==
                 nas_eps_send_attach_reject(mme_ue,

src/smf/context.c

@@ -1184,11 +1184,13 @@ smf_sess_t *smf_sess_add_by_sbi_message(ogs_sbi_message_t *message)
     return sess;
 }
 
-void smf_sess_set_ue_ip(smf_sess_t *sess)
+uint8_t smf_sess_set_ue_ip(smf_sess_t *sess)
 {
     ogs_pfcp_subnet_t *subnet6 = NULL;
     smf_ue_t *smf_ue = NULL;
 
+    uint8_t cause_value = OGS_PFCP_CAUSE_REQUEST_ACCEPTED;
+
     ogs_assert(sess);
     smf_ue = sess->smf_ue;
     ogs_assert(smf_ue);
@@ -1235,16 +1237,24 @@ void smf_sess_set_ue_ip(smf_sess_t *sess)
     }
 
     if (sess->session.session_type == OGS_PDU_SESSION_TYPE_IPV4) {
-        sess->ipv4 = ogs_pfcp_ue_ip_alloc(AF_INET,
+        sess->ipv4 = ogs_pfcp_ue_ip_alloc(&cause_value, AF_INET,
                 sess->session.name, (uint8_t *)&sess->session.ue_ip.addr);
-        ogs_assert(sess->ipv4);
+        if (!sess->ipv4) {
+            ogs_error("ogs_pfcp_ue_ip_alloc() failed[%d]", cause_value);
+            ogs_assert(cause_value != OGS_PFCP_CAUSE_REQUEST_ACCEPTED);
+            return cause_value;
+        }
         sess->session.paa.addr = sess->ipv4->addr[0];
         ogs_hash_set(smf_self()->ipv4_hash,
                 sess->ipv4->addr, OGS_IPV4_LEN, sess);
     } else if (sess->session.session_type == OGS_PDU_SESSION_TYPE_IPV6) {
-        sess->ipv6 = ogs_pfcp_ue_ip_alloc(
+        sess->ipv6 = ogs_pfcp_ue_ip_alloc(&cause_value, AF_INET6,
-                AF_INET6, sess->session.name, sess->session.ue_ip.addr6);
+                sess->session.name, sess->session.ue_ip.addr6);
-        ogs_assert(sess->ipv6);
+        if (!sess->ipv6) {
+            ogs_error("ogs_pfcp_ue_ip_alloc() failed[%d]", cause_value);
+            ogs_assert(cause_value != OGS_PFCP_CAUSE_REQUEST_ACCEPTED);
+            return cause_value;
+        }
 
         subnet6 = sess->ipv6->subnet;
         ogs_assert(subnet6);
@@ -1254,12 +1264,26 @@ void smf_sess_set_ue_ip(smf_sess_t *sess)
         ogs_hash_set(smf_self()->ipv6_hash,
                 sess->ipv6->addr, OGS_IPV6_DEFAULT_PREFIX_LEN >> 3, sess);
     } else if (sess->session.session_type == OGS_PDU_SESSION_TYPE_IPV4V6) {
-        sess->ipv4 = ogs_pfcp_ue_ip_alloc(AF_INET,
+        sess->ipv4 = ogs_pfcp_ue_ip_alloc(&cause_value, AF_INET,
                 sess->session.name, (uint8_t *)&sess->session.ue_ip.addr);
-        ogs_assert(sess->ipv4);
+        if (!sess->ipv4) {
-        sess->ipv6 = ogs_pfcp_ue_ip_alloc(
+            ogs_error("ogs_pfcp_ue_ip_alloc() failed[%d]", cause_value);
-                AF_INET6, sess->session.name, sess->session.ue_ip.addr6);
+            ogs_assert(cause_value != OGS_PFCP_CAUSE_REQUEST_ACCEPTED);
-        ogs_assert(sess->ipv6);
+            return cause_value;
+        }
+        sess->ipv6 = ogs_pfcp_ue_ip_alloc(&cause_value, AF_INET6,
+                sess->session.name, sess->session.ue_ip.addr6);
+        if (!sess->ipv6) {
+            ogs_error("ogs_pfcp_ue_ip_alloc() failed[%d]", cause_value);
+            ogs_assert(cause_value != OGS_PFCP_CAUSE_REQUEST_ACCEPTED);
+            if (sess->ipv4) {
+                ogs_hash_set(smf_self()->ipv4_hash,
+                        sess->ipv4->addr, OGS_IPV4_LEN, NULL);
+                ogs_pfcp_ue_ip_free(sess->ipv4);
+                sess->ipv4 = NULL;
+            }
+            return cause_value;
+        }
 
         subnet6 = sess->ipv6->subnet;
         ogs_assert(subnet6);
@@ -1276,6 +1300,8 @@ void smf_sess_set_ue_ip(smf_sess_t *sess)
                 sess->session.session_type);
         ogs_assert_if_reached();
     }
+
+    return cause_value;
 }
 
 void smf_sess_set_paging_n1n2message_location(

src/smf/context.h

@@ -361,7 +361,7 @@ smf_sess_t *smf_sess_add_by_sbi_message(ogs_sbi_message_t *message);
 smf_sess_t *smf_sess_add_by_psi(smf_ue_t *smf_ue, uint8_t psi);
 
 void smf_sess_select_upf(smf_sess_t *sess);
-void smf_sess_set_ue_ip(smf_sess_t *sess);
+uint8_t smf_sess_set_ue_ip(smf_sess_t *sess);
 void smf_sess_set_paging_n1n2message_location(
         smf_sess_t *sess, char *n1n2message_location);
 

src/smf/n4-handler.c

@@ -58,6 +58,8 @@ static uint8_t gtp_cause_from_pfcp(uint8_t pfcp_cause)
         return OGS_GTP_CAUSE_SERVICE_NOT_SUPPORTED;
     case OGS_PFCP_CAUSE_SYSTEM_FAILURE:
         return OGS_GTP_CAUSE_SYSTEM_FAILURE;
+    case OGS_PFCP_CAUSE_ALL_DYNAMIC_ADDRESS_ARE_OCCUPIED:
+        return OGS_GTP_CAUSE_ALL_DYNAMIC_ADDRESSES_ARE_OCCUPIED;
     default:
         return OGS_GTP_CAUSE_SYSTEM_FAILURE;
     }

src/smf/nudm-handler.c

@@ -244,7 +244,7 @@ bool smf_nudm_sdm_handle_get(smf_sess_t *sess, ogs_sbi_stream_t *stream,
     }
 
     /* Set UE IP Address to the Default DL PDR */
-    smf_sess_set_ue_ip(sess);
+    ogs_assert(OGS_PFCP_CAUSE_REQUEST_ACCEPTED == smf_sess_set_ue_ip(sess));
 
     /*********************************************************************
      * Send HTTP_STATUS_CREATED(/nsmf-pdusession/v1/sm-context) to the AMF

src/smf/s5c-handler.c

@@ -216,7 +216,7 @@ void smf_s5c_handle_create_session_request(
     rv = ogs_gtp_paa_to_ip(paa, &sess->session.ue_ip);
     ogs_assert(rv == OGS_OK);
 
-    smf_sess_set_ue_ip(sess);
+    ogs_assert(OGS_PFCP_CAUSE_REQUEST_ACCEPTED == smf_sess_set_ue_ip(sess));
 
     ogs_info("UE IMSI[%s] APN[%s] IPv4[%s] IPv6[%s]",
 	    smf_ue->imsi_bcd,

src/upf/context.c

@@ -256,13 +256,15 @@ upf_sess_t *upf_sess_add_by_message(ogs_pfcp_message_t *message)
     return sess;
 }
 
-void upf_sess_set_ue_ip(upf_sess_t *sess,
+uint8_t upf_sess_set_ue_ip(upf_sess_t *sess,
         uint8_t session_type, ogs_pfcp_pdr_t *pdr)
 {
     ogs_pfcp_ue_ip_addr_t *ue_ip = NULL;
     char buf1[OGS_ADDRSTRLEN];
     char buf2[OGS_ADDRSTRLEN];
 
+    uint8_t cause_value = OGS_PFCP_CAUSE_REQUEST_ACCEPTED;
+
     ogs_assert(sess);
     ogs_assert(session_type);
     ogs_assert(pdr);
@@ -284,9 +286,13 @@ void upf_sess_set_ue_ip(upf_sess_t *sess,
     /* Set PDN-Type and UE IP Address */
     if (session_type == OGS_PDU_SESSION_TYPE_IPV4) {
         if (ue_ip->ipv4 || pdr->dnn) {
-            sess->ipv4 = ogs_pfcp_ue_ip_alloc(
+            sess->ipv4 = ogs_pfcp_ue_ip_alloc(&cause_value, AF_INET,
-                    AF_INET, pdr->dnn, (uint8_t *)&(ue_ip->addr));
+                            pdr->dnn, (uint8_t *)&(ue_ip->addr));
-            ogs_assert(sess->ipv4);
+            if (!sess->ipv4) {
+                ogs_error("ogs_pfcp_ue_ip_alloc() failed[%d]", cause_value);
+                ogs_assert(cause_value != OGS_PFCP_CAUSE_REQUEST_ACCEPTED);
+                return cause_value;
+            }
             ogs_hash_set(self.ipv4_hash, sess->ipv4->addr, OGS_IPV4_LEN, sess);
         } else {
             ogs_warn("Cannot support PDN-Type[%d], [IPv4:%d IPv6:%d DNN:%s]",
@@ -295,8 +301,13 @@ void upf_sess_set_ue_ip(upf_sess_t *sess,
         }
     } else if (session_type == OGS_PDU_SESSION_TYPE_IPV6) {
         if (ue_ip->ipv6 || pdr->dnn) {
-            sess->ipv6 = ogs_pfcp_ue_ip_alloc(AF_INET6, pdr->dnn, ue_ip->addr6);
+            sess->ipv6 = ogs_pfcp_ue_ip_alloc(&cause_value, AF_INET6,
-            ogs_assert(sess->ipv6);
+                            pdr->dnn, ue_ip->addr6);
+            if (!sess->ipv6) {
+                ogs_error("ogs_pfcp_ue_ip_alloc() failed[%d]", cause_value);
+                ogs_assert(cause_value != OGS_PFCP_CAUSE_REQUEST_ACCEPTED);
+                return cause_value;
+            }
             ogs_hash_set(self.ipv6_hash, sess->ipv6->addr,
                     OGS_IPV6_DEFAULT_PREFIX_LEN >> 3, sess);
         } else {
@@ -306,9 +317,13 @@ void upf_sess_set_ue_ip(upf_sess_t *sess,
         }
     } else if (session_type == OGS_PDU_SESSION_TYPE_IPV4V6) {
         if (ue_ip->ipv4 || pdr->dnn) {
-            sess->ipv4 = ogs_pfcp_ue_ip_alloc(
+            sess->ipv4 = ogs_pfcp_ue_ip_alloc(&cause_value, AF_INET,
-                    AF_INET, pdr->dnn, (uint8_t *)&(ue_ip->both.addr));
+                            pdr->dnn, (uint8_t *)&(ue_ip->both.addr));
-            ogs_assert(sess->ipv4);
+            if (!sess->ipv4) {
+                ogs_error("ogs_pfcp_ue_ip_alloc() failed[%d]", cause_value);
+                ogs_assert(cause_value != OGS_PFCP_CAUSE_REQUEST_ACCEPTED);
+                return cause_value;
+            }
             ogs_hash_set(self.ipv4_hash, sess->ipv4->addr, OGS_IPV4_LEN, sess);
         } else {
             ogs_warn("Cannot support PDN-Type[%d], [IPv4:%d IPv6:%d DNN:%s]",
@@ -317,9 +332,19 @@ void upf_sess_set_ue_ip(upf_sess_t *sess,
         }
 
         if (ue_ip->ipv6 || pdr->dnn) {
-            sess->ipv6 = ogs_pfcp_ue_ip_alloc(
+            sess->ipv6 = ogs_pfcp_ue_ip_alloc(&cause_value, AF_INET6,
-                    AF_INET6, pdr->dnn, ue_ip->both.addr6);
+                            pdr->dnn, ue_ip->both.addr6);
-            ogs_assert(sess->ipv6);
+            if (!sess->ipv6) {
+                ogs_error("ogs_pfcp_ue_ip_alloc() failed[%d]", cause_value);
+                ogs_assert(cause_value != OGS_PFCP_CAUSE_REQUEST_ACCEPTED);
+                if (sess->ipv4) {
+                    ogs_hash_set(self.ipv4_hash,
+                            sess->ipv4->addr, OGS_IPV4_LEN, NULL);
+                    ogs_pfcp_ue_ip_free(sess->ipv4);
+                    sess->ipv4 = NULL;
+                }
+                return cause_value;
+            }
             ogs_hash_set(self.ipv6_hash, sess->ipv6->addr,
                     OGS_IPV6_DEFAULT_PREFIX_LEN >> 3, sess);
         } else {
@@ -339,4 +364,6 @@ void upf_sess_set_ue_ip(upf_sess_t *sess,
         pdr->dnn, session_type,
         sess->ipv4 ? OGS_INET_NTOP(&sess->ipv4->addr, buf1) : "",
         sess->ipv6 ? OGS_INET6_NTOP(&sess->ipv6->addr, buf2) : "");
+
+    return cause_value;
 }

src/upf/context.h

@@ -88,7 +88,7 @@ upf_sess_t *upf_sess_find_by_up_seid(uint64_t seid);
 upf_sess_t *upf_sess_find_by_ipv4(uint32_t addr);
 upf_sess_t *upf_sess_find_by_ipv6(uint32_t *addr6);
 
-void upf_sess_set_ue_ip(upf_sess_t *sess,
+uint8_t upf_sess_set_ue_ip(upf_sess_t *sess,
         uint8_t session_type, ogs_pfcp_pdr_t *pdr);
 
 #ifdef __cplusplus

src/upf/n4-handler.c

@@ -93,7 +93,8 @@ void upf_n4_handle_session_establishment_request(
 
         /* Setup UE IP address */
         if (req->pdn_type.presence && pdr->ue_ip_addr_len) {
-            upf_sess_set_ue_ip(sess, req->pdn_type.u8, pdr);
+            ogs_assert(OGS_PFCP_CAUSE_REQUEST_ACCEPTED ==
+                    upf_sess_set_ue_ip(sess, req->pdn_type.u8, pdr));
         }
 
         /* Setup UPF-N3-TEID & QFI Hash */