Merge remote-tracking branch 'origin/nr-nas-issue-841' into integration_2024_w43 (!2980)

Refactor NAS 5GS PDU Session Establishment Accept handling

- Closes #841
- address minor code issues

openair3/NAS/COMMON/ESM/MSG/PduSessionEstablishmentAccept.c

@@ -124,18 +124,28 @@ void capture_pdu_session_establishment_accept_msg(uint8_t *buffer, uint32_t msg_
       case IEI_PDU_ADDRESS:
         LOG_T(NAS, "PDU SESSION ESTABLISHMENT ACCEPT - Received PDU Address IE\n");
         psea_msg.pdu_addr_ie.pdu_length = *curPtr++;
-        psea_msg.pdu_addr_ie.pdu_type = *curPtr++;
 
+        /* Octet 3 */
+        // PDU type (3 bits)
+        psea_msg.pdu_addr_ie.pdu_type = *curPtr & 0x07;
+        // SMF's IPv6 link local address (1 bit)
+        uint8_t si6lla = (*curPtr >> 3) & 0x01;
+        if (si6lla)
+          LOG_E(NAS, "SMF's IPv6 link local address is not handled\n");
+        curPtr++;
+
+        /* Octet 4 to n */
+        // PDU address information
         uint8_t *addr = psea_msg.pdu_addr_ie.pdu_addr_oct;
         if (psea_msg.pdu_addr_ie.pdu_type == PDU_SESSION_TYPE_IPV4) {
-          for (int i = 0; i < 4; ++i)
+          for (int i = 0; i < IPv4_ADDRESS_LENGTH; ++i)
             addr[i] = *curPtr++;
           char ip[20];
           capture_ipv4_addr(&addr[0], ip, sizeof(ip));
           tun_config(1, ip, NULL, "oaitun_ue");
           setup_ue_ipv4_route(1, ip, "oaitun_ue");
         } else if (psea_msg.pdu_addr_ie.pdu_type == PDU_SESSION_TYPE_IPV6) {
-          for (int i = 0; i < 8; ++i)
+          for (int i = 0; i < IPv6_INTERFACE_ID_LENGTH; ++i)
             addr[i] = *curPtr++;
           char ipv6[40];
           capture_ipv6_addr(addr, ipv6, sizeof(ipv6));
@@ -145,12 +155,12 @@ void capture_pdu_session_establishment_accept_msg(uint8_t *buffer, uint32_t msg_
           // IPv4v6, the PDU address information in octet 4 to octet 11
           // contains an interface identifier for the IPv6 link local address
           // and in octet 12 to octet 15 contains an IPv4 address."
-          for (int i = 0; i < 12; ++i)
+          for (int i = 0; i < IPv4_ADDRESS_LENGTH + IPv6_INTERFACE_ID_LENGTH; ++i)
             addr[i] = *curPtr++;
           char ipv6[40];
           capture_ipv6_addr(addr, ipv6, sizeof(ipv6));
           char ipv4[20];
-          capture_ipv4_addr(&addr[8], ipv4, sizeof(ipv4));
+          capture_ipv4_addr(&addr[IPv6_INTERFACE_ID_LENGTH], ipv4, sizeof(ipv4));
           tun_config(1, ipv4, ipv6, "oaitun_ue");
           setup_ue_ipv4_route(1, ipv4, "oaitun_ue");
         } else {
@@ -164,42 +174,47 @@ void capture_pdu_session_establishment_accept_msg(uint8_t *buffer, uint32_t msg_
         curPtr++; /* TS 24.008 10.5.7.3 */
         break;
 
-      case IEI_SNSSAI: /* Ommited */
+      case IEI_SNSSAI: {
         LOG_T(NAS, "PDU SESSION ESTABLISHMENT ACCEPT - Received S-NSSAI IE\n");
         uint8_t snssai_length = *curPtr;
         curPtr += (snssai_length + sizeof(snssai_length));
         break;
+      }
 
       case IEI_ALWAYSON_PDU: /* Ommited */
         LOG_T(NAS, "PDU SESSION ESTABLISHMENT ACCEPT - Received Always-on PDU Session indication IE\n");
         curPtr++;
         break;
 
-      case IEI_MAPPED_EPS: /* Ommited */
+      case IEI_MAPPED_EPS: {
         LOG_T(NAS, "PDU SESSION ESTABLISHMENT ACCEPT - Received Mapped EPS bearer context IE\n");
         uint16_t mapped_eps_length = getShort(curPtr);
         curPtr += mapped_eps_length;
         break;
+      }
 
-      case IEI_EAP_MSG: /* Ommited */
+      case IEI_EAP_MSG: {
         LOG_T(NAS, "PDU SESSION ESTABLISHMENT ACCEPT - Received EAP message IE\n");
         uint16_t eap_length = getShort(curPtr);
         curPtr += (eap_length + sizeof(eap_length));
         break;
+      }
 
-      case IEI_AUTH_QOS_DESC: /* Ommited */
+      case IEI_AUTH_QOS_DESC: {
         LOG_T(NAS, "PDU SESSION ESTABLISHMENT ACCEPT - Received Authorized QoS flow descriptions IE\n");
         psea_msg.qos_fd_ie.length = getShort(curPtr);
         curPtr += (psea_msg.qos_fd_ie.length + sizeof(psea_msg.qos_fd_ie.length));
         break;
+      }
 
-      case IEI_EXT_CONF_OPT: /* Ommited */
+      case IEI_EXT_CONF_OPT: {
         LOG_T(NAS, "PDU SESSION ESTABLISHMENT ACCEPT - Received Extended protocol configuration options IE\n");
         psea_msg.ext_pp_ie.length = getShort(curPtr);
         curPtr += (psea_msg.ext_pp_ie.length + sizeof(psea_msg.ext_pp_ie.length));
         break;
+      }
 
-      case IEI_DNN:
+      case IEI_DNN: {
         LOG_T(NAS, "PDU SESSION ESTABLISHMENT ACCEPT - Received DNN IE\n");
         psea_msg.dnn_ie.dnn_length = *curPtr++;
         char apn[APN_MAX_LEN];
@@ -213,6 +228,7 @@ void capture_pdu_session_establishment_accept_msg(uint8_t *buffer, uint32_t msg_
 
         curPtr = buffer + msg_length; // we force stop processing
         break;
+      }
 
       default:
         LOG_T(NAS, "PDU SESSION ESTABLISHMENT ACCEPT - Not known IE\n");

openair3/NAS/COMMON/ESM/MSG/PduSessionEstablishmentAccept.h

@@ -42,6 +42,9 @@
 #define PDU_SESSION_TYPE_IPV4   0b001
 #define PDU_SESSION_TYPE_IPV6   0b010
 #define PDU_SESSION_TYPE_IPV4V6 0b011
+#define IPv4_ADDRESS_LENGTH      4 // length of the IPv4 address associated with a PDU session
+#define IPv6_INTERFACE_ID_LENGTH 8 // interface identifier for the IPv6 link local address
+#define SMF_IPv6_LLA_LENGTH 16
 
 /* Rule operation codes - TS 24.501 Table 9.11.4.13.1 */
 
@@ -114,7 +117,8 @@ typedef struct pdu_address_s {
   uint8_t pdu_iei;        /* PDU Address IEI (0x29) */
   uint8_t pdu_length;     /* Length of PDU address contents */
   uint8_t pdu_type;       /* PDU session type value */
-  uint8_t pdu_addr_oct[12];  /* PDU address information (depending on type, up to 12 bytes)*/
+  /// PDU address information (depending on type, up to 12 bytes)
+  uint8_t pdu_addr_oct[IPv4_ADDRESS_LENGTH + IPv6_INTERFACE_ID_LENGTH];
 } pdu_address_t; /* TS 24.501 9.11.4.10 */
 
 typedef struct dnn_s {

openair3/NAS/NR_UE/nr_nas_msg.c

@@ -848,16 +848,15 @@ static void generateRegistrationComplete(nr_ue_nas_t *nas,
   }
 }
 
-void decodeDownlinkNASTransport(as_nas_info_t *initialNasMsg, uint8_t *pdu_buffer)
+/**
+ * @brief Handle DL NAS Transport and process piggybacked 5GSM messages
+ */
+static void handleDownlinkNASTransport(uint8_t *pdu_buffer, uint32_t msg_length)
 {
   uint8_t msg_type = *(pdu_buffer + 16);
   if (msg_type == FGS_PDU_SESSION_ESTABLISHMENT_ACC) {
-    uint8_t *ip_p = pdu_buffer + 39;
-    char ip[20];
-    sprintf(ip, "%d.%d.%d.%d", *(ip_p), *(ip_p + 1), *(ip_p + 2), *(ip_p + 3));
-    LOG_A(NAS, "Received PDU Session Establishment Accept\n");
-    tun_config(1, ip, NULL, "oaitun_ue");
-    setup_ue_ipv4_route(1, ip, "oaitun_ue");
+    LOG_A(NAS, "Received PDU Session Establishment Accept in DL NAS Transport\n");
+    capture_pdu_session_establishment_accept_msg(pdu_buffer, msg_length);
   } else {
     LOG_E(NAS, "Received unexpected message in DLinformationTransfer %d\n", msg_type);
   }
@@ -1415,7 +1414,7 @@ void *nas_nrue(void *args_p)
             handle_security_mode_command(nas, &initialNasMsg, pdu_buffer, pdu_length);
             break;
           case FGS_DOWNLINK_NAS_TRANSPORT:
-            decodeDownlinkNASTransport(&initialNasMsg, pdu_buffer);
+            handleDownlinkNASTransport(pdu_buffer, pdu_length);
             break;
           case REGISTRATION_ACCEPT:
             handle_registration_accept(nas, pdu_buffer, pdu_length);
@@ -1423,32 +1422,9 @@ void *nas_nrue(void *args_p)
           case FGS_DEREGISTRATION_ACCEPT_UE_ORIGINATING:
             LOG_I(NAS, "received deregistration accept\n");
             break;
-          case FGS_PDU_SESSION_ESTABLISHMENT_ACC: {
-            uint8_t offset = 0;
-            uint8_t *payload_container = pdu_buffer;
-            offset += SECURITY_PROTECTED_5GS_NAS_MESSAGE_HEADER_LENGTH;
-            uint32_t payload_container_length = htons(((dl_nas_transport_t *)(pdu_buffer + offset))->payload_container_length);
-            if ((payload_container_length >= PAYLOAD_CONTAINER_LENGTH_MIN)
-                && (payload_container_length <= PAYLOAD_CONTAINER_LENGTH_MAX))
-              offset += (PLAIN_5GS_NAS_MESSAGE_HEADER_LENGTH + 3);
-            if (offset < NAS_CONN_ESTABLI_CNF(msg_p).nasMsg.length)
-              payload_container = pdu_buffer + offset;
-
-            while (offset < payload_container_length) {
-              if (*(payload_container + offset) == 0x29) { // PDU address IEI
-                if ((*(payload_container + offset + 1) == 0x05) && (*(payload_container + offset + 2) == 0x01)) { // IPV4
-                  uint8_t *ip_p = payload_container + offset + 3;
-                  char ip[20];
-                  snprintf(ip, sizeof(ip), "%d.%d.%d.%d", *(ip_p), *(ip_p + 1), *(ip_p + 2), *(ip_p + 3));
-                  LOG_I(NAS, "Received PDU Session Establishment Accept, UE IP: %s\n", ip);
-                  tun_config(1, ip, NULL, "oaitun_ue");
-                  setup_ue_ipv4_route(1, ip, "oaitun_ue");
-                  break;
-                }
-              }
-              offset++;
-            }
-          } break;
+          case FGS_PDU_SESSION_ESTABLISHMENT_ACC:
+            capture_pdu_session_establishment_accept_msg(pdu_buffer, pdu_length);
+            break;
           case FGS_PDU_SESSION_ESTABLISHMENT_REJ:
             LOG_E(NAS, "Received PDU Session Establishment reject\n");
             break;