Merge remote-tracking branch 'origin/cleanup-pdu-session' into integration_2025_w26 (!3435)

Cleanup PDU Session Handling in RRC/NGAP

Currently, NGAP and RRC share the same structures and responsibilities when
handling PDU Session information: this creates tight coupling, redundancy, and
makes the code harder to maintain.

- NGAP should be responsible only for: Protocol-specific encoding/decoding
(3GPP TS 38.413)
- RRC should own: PDU Session handling and storage in the UE context

This MR is the first step in a broader refactoring of the PDU Session handling
code across NGAP and RRC layers, with the goal of splitting responsibilities
cleanly between both modules.

- Unified gtpu_tunnel_t for tunnel endpoint config (formerly f1u_tunnel_t)
- Refactored and relocated PDU Session struct definitions for better separation
  between NGAP and RRC
  - Moved pdusession_t for PDU Session handling out of NGAP, now defined and
    managed by RRC only
  - Defined 3GPP TS 38.413 message-specific structs in NGAP module
  - NGAP now decodes NGAP PDU Session Resource Setup/Modify IEs and transfers
    decoded data to RRC via ITTI
  - Add helper functions to copy from NGAP message to pdusession_t
- Introduced new encoders/decoders/helpers in NGAP for handling PDU Session
  Resource Setup/Modify procedures (e.g. decode_pdusession_transfer)
  - Migrated to NGAP and removed duplicated logic for QoS information decoding
    (fill_qos)
- Improved logging of GTP tunnel info
- Merged redundant functions (f1u_dl_gtp_update and f1u_ul_gtp_update)
- Removed unused code and obsolete types
- do free_func in seq_arr_erase_it on the provided range and updated unit test
- Other fixes and simplifications (e.g. simplified and clarified naming of
  tunnel/session parameters and structs)

This cleanup improves code readability, has a high code churn (the deletions are
~159.7% of the insertions) and prepares for better modularity before the
refactoring of PDU Session handling in RRC/NGAP.

common/5g_platform_types.h

@@ -45,6 +45,14 @@ typedef struct nr_guami_s {
   uint8_t amf_pointer;
 } nr_guami_t;
 
+typedef enum {
+  PDUSessionType_ipv4 = 0,
+  PDUSessionType_ipv6 = 1,
+  PDUSessionType_ipv4v6 = 2,
+  PDUSessionType_ethernet = 3,
+  PDUSessionType_unstructured = 4
+} pdu_session_type_t;
+
 typedef enum { NON_DYNAMIC, DYNAMIC } fiveQI_t;
 
 #endif

common/platform_types.h

@@ -218,25 +218,27 @@ typedef struct nr_lcid_rb_t {
 } nr_lcid_rb_t;
 
 typedef struct transport_layer_addr_s {
-  /**
-   * Transport Layer Address as a bitstring:
-   * - 32 bits for IPv4 (RFC 791),
-   * - 128 bits for IPv6 (RFC 2460),
-   * - 160 bits for both IPv4 and IPv6, with IPv4 in the first 32 bits.
-   * The S1AP/NGAP layer forwards this address (bitstring<1..160>)
-   * to S1-U/NG-U without interpreting it.
-   */
+  /** Transport Layer Address in bytes:
+   * - 4 bytes for IPv4 (RFC 791), 16 bytes for IPv6 (RFC 2460),
+   * - 20 bytes for both IPv4 and IPv6, with IPv4 in the first 4 bytes. */
   uint8_t length;
   /// Buffer: address in network byte order
   uint8_t buffer[20];
 } transport_layer_addr_t;
 
+/** @brief GTP tunnel configuration */
+typedef struct {
+  // Tunnel endpoint identifier
+  uint32_t teid;
+  // Transport layer address
+  transport_layer_addr_t addr;
+} gtpu_tunnel_t;
+
 //-----------------------------------------------------------------------------
 // GTPV1U TYPES
 //-----------------------------------------------------------------------------
 typedef uint32_t teid_t; // tunnel endpoint identifier
 typedef uint8_t ebi_t; // eps bearer id
-typedef uint8_t pdusessionid_t;
 
 //-----------------------------------------------------------------------------
 //

common/utils/ds/seq_arr.c

@@ -123,11 +123,10 @@ void seq_arr_erase_it(seq_arr_t* arr, void* start_it, void* end_it, void (*free_
     return;
 
   if (free_func != NULL) {
-    void* start_it = seq_arr_front(arr);
-    void* end_it = seq_arr_end(arr);
-    while (start_it != end_it) {
-      free_func(start_it);
-      start_it = seq_arr_next(arr, start_it);
+    void* it = start_it;
+    while (it != end_it) {
+      free_func(it);
+      it = seq_arr_next(arr, it);
     }
   }
 

common/utils/ds/tests/test_seq_array.c

@@ -36,6 +36,13 @@ static int compar(const void* m0, const void* m1)
   return 1;
 }
 
+static int free_func_call_count = 0;
+
+static void dummy_free_func(void* it)
+{
+  ++free_func_call_count;
+}
+
 int main()
 {
   seq_arr_t arr = {0};
@@ -83,6 +90,19 @@ int main()
   void* it = bsearch(&key, base, nmemb, size, compar);
   assert(seq_arr_dist(&arr, seq_arr_front(&arr), it) == 4);
 
+  // Regression test: erase a partial range only
+  // Erase 92, 93, 94 (i.e., indices 1 to 3)
+  int* start = seq_arr_at(&arr, 1);
+  int* end = seq_arr_at(&arr, 4);
+  seq_arr_erase_it(&arr, start, end, dummy_free_func);
+
+  // Now values should be: [91, 95, 96, 97, 98, 99]
+  assert(free_func_call_count == 3);
+  assert(seq_arr_size(&arr) == 6);
+  assert(*(int*)seq_arr_at(&arr, 0) == 91);
+  assert(*(int*)seq_arr_at(&arr, 1) == 95);
+  assert(*(int*)seq_arr_at(&arr, 5) == 99);
+
   // Free data structure
   seq_arr_free(&arr, NULL);