From dc968d4dc965bcf753635f9d8f82360774e5fcdf Mon Sep 17 00:00:00 2001
From: Robert Schmidt <robert.schmidt@openairinterface.org>
Date: Wed, 7 Jan 2026 17:27:51 +0100
Subject: [PATCH] Handle PDU session type Ethernet in NAS and SDAP

---
 openair2/SDAP/nr_sdap/nr_sdap.c |  9 +++++++++
 openair2/SDAP/nr_sdap/nr_sdap.h |  1 +
 openair3/NAS/NR_UE/nr_nas_msg.c | 11 +++++++----
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/openair2/SDAP/nr_sdap/nr_sdap.c b/openair2/SDAP/nr_sdap/nr_sdap.c
index a38550f993..29e5dc93db 100644
--- a/openair2/SDAP/nr_sdap/nr_sdap.c
+++ b/openair2/SDAP/nr_sdap/nr_sdap.c
@@ -197,6 +197,15 @@ void create_ue_ip_if(const char *ipv4, const char *ipv6, int ue_id, int pdu_sess
   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);
diff --git a/openair2/SDAP/nr_sdap/nr_sdap.h b/openair2/SDAP/nr_sdap/nr_sdap.h
index 682c97b6fc..bb85fdf249 100644
--- a/openair2/SDAP/nr_sdap/nr_sdap.h
+++ b/openair2/SDAP/nr_sdap/nr_sdap.h
@@ -62,5 +62,6 @@ void sdap_data_ind(int pdcp_entity,
 
 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
diff --git a/openair3/NAS/NR_UE/nr_nas_msg.c b/openair3/NAS/NR_UE/nr_nas_msg.c
index 3add94a549..1e6c98b744 100644
--- a/openair3/NAS/NR_UE/nr_nas_msg.c
+++ b/openair3/NAS/NR_UE/nr_nas_msg.c
@@ -1568,11 +1568,14 @@ static void handle_pdu_session_accept(const nr_ue_nas_t *nas, uint8_t *pdu_buffe
 
   // process PDU Session: pass ID -1 to not append PDU ID to interface
   bool is_default = idx == 0;
-  if (msg.pdu_addr_ie.pdu_length)
+  if (msg.pdu_type == PDU_SESSION_TYPE_ETHER) {
+    create_ue_eth_if(instance, sm_header.pdu_session_id, is_default);
+  } else if (msg.pdu_addr_ie.pdu_length) {
     process_pdu_session_addr(&msg, instance, sm_header.pdu_session_id, is_default);
-  else
-    LOG_W(NAS, "Optional PDU Address IE was not provided\n");
-  
+  } else {
+    LOG_W(NAS, "Unhandled PDU session type %d, ignoring PDU session ID %d\n", msg.pdu_type, sm_header.pdu_session_id);
+  }
+
   set_qfi(msg.qos_rules.rule->qfi, sm_header.pdu_session_id, instance);
 }