gtp_ext_hdr_qfi_1.patch

This patch was created for UPG-VPP v1.13.0 based on the following OAI patch.
It is a temporary patch with QFI fixed to 1.

https://gitlab.eurecom.fr/oai/cn5g/oai-cn5g-upf-vpp/-/commit/d9909c42e7c70029c3d6b39ebf5132d99032c231

diff -urN upg-vpp.orig/upf/upf_gtpu_encap.c upg-vpp/upf/upf_gtpu_encap.c
--- upg-vpp.orig/upf/upf_gtpu_encap.c	2024-05-04 23:55:50.000000000 +0900
+++ upg-vpp/upf/upf_gtpu_encap.c	2024-06-04 19:35:06.000000000 +0900
@@ -874,6 +874,8 @@
           ip6_header_t *ip6_0;
           udp_header_t *udp0;
           gtpu_header_t *gtpu0;
+          gtpu_ext_header_t *gtpu0_ext;
+          bool ext_hdr_present;
           u64 *copy_src0, *copy_dst0;
           u32 *copy_src_last0, *copy_dst_last0;
           u16 new_l0;
@@ -907,6 +909,17 @@
           next0 = peer0->next_dpo.dpoi_next_node;
           vnet_buffer (b0)->ip.adj_index[VLIB_TX] = peer0->next_dpo.dpoi_index;
 
+          gtpu_ext_header_t *gtpu0_tmp;
+          gtpu0_tmp = vlib_buffer_get_current (b0) - 4;
+          ext_hdr_present = false;
+          if (gtpu0_tmp->type ==  0x01 & gtpu0_tmp->pad == GTPU_QFI)
+            ext_hdr_present = true;
+
+          if (far0->forward.dst_intf == PFCP_DST_INTF_ACCESS & !ext_hdr_present) {
+            upf_buffer_opaque (b0)->gtpu.ext_hdr_len = 0x08;
+            vlib_buffer_advance (b0, -upf_buffer_opaque (b0)->gtpu.ext_hdr_len);      
+          }
+
           if (PREDICT_FALSE ((upf_buffer_opaque (b0)->gtpu.hdr_flags &
                               GTPU_E_S_PN_BIT) != 0))
             vlib_buffer_advance (b0,
@@ -953,8 +966,19 @@
                 vlib_buffer_length_in_chain (vm, b0) - sizeof (*ip4_0) -
                 sizeof (*udp0) - GTPU_V1_HDR_LEN);
               gtpu0->length = new_l0;
-              gtpu0->ver_flags |=
-                (upf_buffer_opaque (b0)->gtpu.hdr_flags & GTPU_E_S_PN_BIT);
+              if (far0->forward.dst_intf == PFCP_DST_INTF_ACCESS & !ext_hdr_present) {
+                gtpu0->ver_flags = GTPU_EXT_HDR_PRESENT;
+                gtpu0->pdu_number = 0x00;
+                gtpu0->sequence = 0x00;
+                gtpu0->next_ext_type = GTPU_EXT_HDR_PDU_SESSION_CONTAINER;
+
+                gtpu0_ext = (gtpu_ext_header_t *) (gtpu0 + 1);
+                gtpu0_ext->type = 0x01;
+                gtpu0_ext->len = 0x00;
+                gtpu0_ext->pad = GTPU_QFI;
+              }
+              else
+                gtpu0->ver_flags |= (upf_buffer_opaque (b0)->gtpu.hdr_flags & GTPU_E_S_PN_BIT);
             }
 
           else /* ip6 path */
diff -urN upg-vpp.orig/upf/upf.h upg-vpp/upf/upf.h
--- upg-vpp.orig/upf/upf.h	2024-05-04 23:55:50.000000000 +0900
+++ upg-vpp/upf/upf.h	2024-06-04 19:35:31.000000000 +0900
@@ -115,6 +115,7 @@
 /* clang-format on */
 
 #define GTPU_V1_HDR_LEN 8
+#define GTPU_V1_EXT_HDR_LEN 8
 
 #define GTPU_VER_MASK   (7 << 5)
 #define GTPU_PT_BIT     (1 << 4)
@@ -143,6 +144,11 @@
 #define GTPU_IE_TEID_I      16
 #define GTPU_IE_GSN_ADDRESS 133
 
+#define GTPU_EXT_HDR_PRESENT 52
+#define GTPU_EXT_HDR_PDU_SESSION_CONTAINER 133
+#define GTPU_NO_MORE_EXT_HDR 0
+#define GTPU_QFI 1
+
 /* clang-format off */
 typedef CLIB_PACKED(struct
 {