Merge remote-tracking branch 'origin/add-support-eth-pdu-sess' into integration_2026_w05 (!3769)

Add Ethernet PDU session support and make PDU session request configurable

This MR adds support for Ethernet PDU sessions, and makes PDU sessions
configurable: per-PDU session ID, type (IPv4/IPv4v6/IPv6/Ethernet [1]),
DNN, NSSAI.

Concretely, it adds a new configuration file section pdu_sessions below
uicc0 that looks like this if everything is specified (default values
are shown):

    uicc0:
      [...]
      pdu_sessions:
        - id: 1
          type: "IPv4"
          nssai_sst: 1
          nssai_sd: 0xffffff
          dnn: "oai"

It is possible to list multiple PDU sessions (add new line   - id: 2 to
request a second PDU session). It is backwards-compatible to the current
PDU session configuration (uicc0.dnn/nssai_sst/etc), the idea being that
either legacy or new configuration could be used, but (1) if
pdu_sessions exist, it will overwrite the legacy configuration, and (2)
multiple PDU sessions, and type, can only be configured using the new
config. The old parameters --extra-pdu-id and --default-pdu-id are not
accepted anymore. Documentation has been added to the UE tutorial.

It is possible to test an Ethernet PDU session [1]. It is possible to
test the PDU session inside the UE by verifying it has an TAP interface
oaitap_ue1, and ARPing the data network (arping has been added to
oai-nr-ue container for that purpose):

    ip addr add 192.168.72.140/26 dev oaitap_ue1  # same subnet as data network!
    ip link set dev oaitap_ue1 up
    arping -c 20 -I oaitap_ue1 192.168.72.135     # will send ARP request in Ethernet frame to get IP address of data network

[1] See description MR !3769 for more information. On the UE side, only
the type has to be changed to "Ethernet".

openair2/COMMON/as_message.h

@@ -474,6 +474,7 @@ typedef struct nas_pdu_session_req_s {
   int pdusession_type;
   int sst;
   int sd;
+  char dnn[103]; /* 24.501 §9.11.2.1A: max length 102 + 0-byte */
 } nas_pdu_session_req_t;
 
 /*

openair2/LAYER2/PDCP_v10.1.0/pdcp.c

@@ -49,7 +49,7 @@
 #include "common/ngran_types.h"
 #include "common/openairinterface5g_limits.h"
 #include "executables/lte-softmodem.h"
-#include "common/utils/tun_if.h"
+#include "common/utils/tuntap_if.h"
 #include "intertask_interface.h"
 #include "openair3/S1AP/s1ap_eNB.h"
 #include <pthread.h>

openair2/LAYER2/nr_pdcp/nr_pdcp_oai_api.c

@@ -46,7 +46,7 @@
 #include "common/platform_constants.h"
 #include "common/ran_context.h"
 #include "common/utils/T/T.h"
-#include "common/utils/tun_if.h"
+#include "common/utils/tuntap_if.h"
 #include "cuup_cucp_if.h"
 #include "executables/lte-softmodem.h"
 #include "executables/softmodem-common.h"
@@ -405,7 +405,7 @@ void nr_pdcp_layer_init(void)
 
 #include "nfapi/oai_integration/vendor_ext.h"
 #include "executables/lte-softmodem.h"
-#include "common/utils/tun_if.h"
+#include "common/utils/tuntap_if.h"
 #include "openair2/SDAP/nr_sdap/nr_sdap.h"
 
 static void deliver_sdu_drb(void *_ue, nr_pdcp_entity_t *entity,

openair2/RRC/LTE/rrc_UE.c

@@ -64,7 +64,7 @@
 #include "LTE_UECapabilityEnquiry.h"
 #include "LTE_UE-CapabilityRequest.h"
 
-#include "common/utils/tun_if.h"
+#include "common/utils/tuntap_if.h"
 #if ENABLE_RAL
   #include "rrc_UE_ral.h"
 #endif

openair2/RRC/LTE/rrc_eNB.c

@@ -79,7 +79,7 @@
 #include "T.h"
 #include "LTE_MeasResults.h"
 
-#include "common/utils/tun_if.h"
+#include "common/utils/tuntap_if.h"
 
 #include "rrc_eNB_S1AP.h"
 #include "rrc_eNB_GTPV1U.h"

openair2/RRC/NR/rrc_gNB_nsa.c

@@ -201,7 +201,7 @@ void rrc_add_nsa_user(gNB_RRC_INST *rrc, x2ap_ENDC_sgnb_addition_req_t *m, sctp_
   byte_array_t cgci = {0};
   if (get_softmodem_params()->phy_test == 1 || get_softmodem_params()->do_ra == 1) {
     DevAssert(m == NULL);
-    UE->rb_config = get_default_rbconfig(10 /* EPS bearer ID */, 1 /* drb ID */, NR_CipheringAlgorithm_nea0, NR_SecurityConfig__keyToUse_master, &rrc->pdcp_config);
+    UE->rb_config = get_default_rbconfig(DEFAULT_NOS1_PDU_ID, 1 /* drb ID */, NR_CipheringAlgorithm_nea0, NR_SecurityConfig__keyToUse_master, &rrc->pdcp_config);
     int len = cg_config_info_from_ue_cap_file(sizeof tmp, tmp);
     DevAssert(len > 0);
     cgci = create_byte_array(len, tmp);

openair2/SDAP/nr_sdap/nr_sdap.c

@@ -29,7 +29,7 @@
 #include "common/utils/LOG/log.h"
 #include "errno.h"
 #include "rlc.h"
-#include "tun_if.h"
+#include "tuntap_if.h"
 #include "system.h"
 
 static void reblock_tun_socket(int fd)
@@ -157,25 +157,27 @@ static void *sdap_tun_read_thread(void *arg)
   return NULL;
 }
 
-void start_sdap_tun_gnb_first_ue_default_pdu_session(ue_id_t ue_id)
+void start_sdap_tun_gnb_first_ue_default_pdu_session(ue_id_t ue_id, int pdu_session_id)
 {
-  nr_sdap_entity_t *entity = nr_sdap_get_entity(ue_id, get_softmodem_params()->default_pdu_session_id);
+  nr_sdap_entity_t *entity = nr_sdap_get_entity(ue_id, pdu_session_id);
   DevAssert(entity != NULL);
   DevAssert(entity->is_gnb);
   char *ifprefix = get_softmodem_params()->nsa ? "oaitun_gnb" : "oaitun_enb";
   char ifname[IFNAMSIZ];
   tun_generate_ifname(ifname, ifprefix, ue_id - 1);
-  entity->pdusession_sock = tun_alloc(ifname);
+  entity->pdusession_sock = tuntap_alloc(IFF_TUN, ifname);
+  entity->pdusession_if_name = strdup(ifname);
   tun_config(ifname, "10.0.1.1", NULL);
   threadCreate(&entity->pdusession_thread, sdap_tun_read_thread, entity, "gnb_tun_read_thread", -1, OAI_PRIORITY_RT_LOW);
 }
 
-void start_sdap_tun_ue(ue_id_t ue_id, int pdu_session_id, int sock)
+static void start_sdap_tun_ue(ue_id_t ue_id, int pdu_session_id, int sock, const char *ifname)
 {
   nr_sdap_entity_t *entity = nr_sdap_get_entity(ue_id, pdu_session_id);
   DevAssert(entity != NULL);
   DevAssert(!entity->is_gnb);
   entity->pdusession_sock = sock;
+  entity->pdusession_if_name = strdup(ifname);
   entity->stop_thread = false;
   char thread_name[64];
   snprintf(thread_name, sizeof(thread_name), "ue_tun_read_%ld_p%d", ue_id, pdu_session_id);
@@ -183,22 +185,32 @@ void start_sdap_tun_ue(ue_id_t ue_id, int pdu_session_id, int sock)
 }
 
 
-void create_ue_ip_if(const char *ipv4, const char *ipv6, int ue_id, int pdu_session_id)
+void create_ue_ip_if(const char *ipv4, const char *ipv6, int ue_id, int pdu_session_id, bool is_default)
 {
-  int default_pdu = get_softmodem_params()->default_pdu_session_id;
   char ifname[IFNAMSIZ];
-  tun_generate_ue_ifname(ifname, ue_id, pdu_session_id != default_pdu ? pdu_session_id : -1);
-  const int sock = tun_alloc(ifname);
+  tuntap_generate_ue_ifname(ifname, IFF_TUN, ue_id, is_default ? -1 : pdu_session_id);
+  const int sock = tuntap_alloc(IFF_TUN, ifname);
   tun_config(ifname, ipv4, ipv6);
   if (ipv4) {
     setup_ue_ipv4_route(ifname, ue_id, ipv4);
   }
-  start_sdap_tun_ue(ue_id, pdu_session_id, sock); // interface name suffix is ue_id+1
+  start_sdap_tun_ue(ue_id, pdu_session_id, sock, ifname); // interface name suffix is ue_id+1
+}
+
+void create_ue_eth_if(int ue_id, int pdu_session_id, bool is_default)
+{
+  char ifname[IFNAMSIZ];
+  tuntap_generate_ue_ifname(ifname, IFF_TAP, ue_id, is_default ? -1 : pdu_session_id);
+  const int sock = tuntap_alloc(IFF_TAP, ifname);
+  tap_config(ifname); // brings the interface up
+  start_sdap_tun_ue(ue_id, pdu_session_id, sock, ifname);
 }
 
 void remove_ip_if(nr_sdap_entity_t *entity)
 {
   DevAssert(entity != NULL);
+  DevAssert(entity->pdusession_if_name != NULL);
+
   // Stop the read thread
   entity->stop_thread = true;
 
@@ -208,13 +220,7 @@ void remove_ip_if(nr_sdap_entity_t *entity)
   int ret = pthread_join(entity->pdusession_thread, NULL);
   AssertFatal(ret == 0, "pthread_join() failed, errno: %d, %s\n", errno, strerror(errno));
   // Bring down the IP interface
-  int default_pdu = get_softmodem_params()->default_pdu_session_id;
-  char ifname[IFNAMSIZ];
-  if (entity->is_gnb) {
-    char *ifprefix = get_softmodem_params()->nsa ? "oaitun_gnb" : "oaitun_enb";
-    tun_generate_ifname(ifname, ifprefix, entity->ue_id - 1);
-  } else {
-    tun_generate_ue_ifname(ifname, entity->ue_id, entity->pdusession_id != default_pdu ? entity->pdusession_id : -1);
-  }
-  tun_destroy(ifname);
+  tuntap_destroy(entity->pdusession_if_name);
+  free(entity->pdusession_if_name);
+  entity->pdusession_if_name = NULL;
 }

openair2/SDAP/nr_sdap/nr_sdap.h

@@ -60,8 +60,8 @@ void sdap_data_ind(int pdcp_entity,
                    char *buf,
                    int size);
 
-void start_sdap_tun_ue(ue_id_t ue_id, int pdu_session_id, int sock);
-void start_sdap_tun_gnb_first_ue_default_pdu_session(ue_id_t ue_id);
-void create_ue_ip_if(const char *ipv4, const char *ipv6, int ue_id, int pdu_session_id);
+void start_sdap_tun_gnb_first_ue_default_pdu_session(ue_id_t ue_id, int pdu_session_id);
+void create_ue_ip_if(const char *ipv4, const char *ipv6, int ue_id, int pdu_session_id, bool is_default);
+void create_ue_eth_if(int ue_id, int pdu_session_id, bool is_default);
 
 #endif

openair2/SDAP/nr_sdap/nr_sdap_entity.c

@@ -31,7 +31,7 @@
 #include "gtpv1_u_messages_types.h"
 #include "intertask_interface.h"
 #include "rlc.h"
-#include "tun_if.h"
+#include "tuntap_if.h"
 #include "nr_sdap.h"
 
 #define NO_SDAP_HEADER 0
@@ -534,7 +534,7 @@ static void nr_sdap_add_entity(const int is_gnb, const ue_id_t ue_id, const sdap
   if (IS_SOFTMODEM_NOS1 && is_gnb) {
     // In NOS1 mode, terminate SDAP for the first UE on the gNB. This allows injecting/receiving
     // PDCP SDUs to/from the TUN interface.
-    start_sdap_tun_gnb_first_ue_default_pdu_session(ue_id);
+    start_sdap_tun_gnb_first_ue_default_pdu_session(ue_id, sdap_entity->pdusession_id);
   }
 }
 

openair2/SDAP/nr_sdap/nr_sdap_entity.h

@@ -102,6 +102,7 @@ typedef struct nr_sdap_entity_s {
   bool enable_sdap;
   int pdusession_id;
   int pdusession_sock;
+  char *pdusession_if_name;
   pthread_t pdusession_thread;
   bool stop_thread;
   int qfi;