From 4ca43c68045edd83d2e3a482b9d06daa130fb303 Mon Sep 17 00:00:00 2001
From: Andre Puschmann <andre@softwareradiosystems.com>
Date: Wed, 3 Feb 2021 17:24:47 +0100
Subject: [PATCH] mac_sch_pdu_nr: add unpacking helpers for CRNTI, SBSR and PHR
 CEs

* unpackers for CEs
* testcase with TV
---
 lib/include/srslte/mac/mac_sch_pdu_nr.h | 15 ++++++++
 lib/src/mac/mac_sch_pdu_nr.cc           | 36 +++++++++++++++++++
 lib/test/mac/mac_pdu_nr_test.cc         | 47 +++++++++++++++++++++++++
 3 files changed, 98 insertions(+)

diff --git a/lib/include/srslte/mac/mac_sch_pdu_nr.h b/lib/include/srslte/mac/mac_sch_pdu_nr.h
index 1fdd324f3..488dfc9e0 100644
--- a/lib/include/srslte/mac/mac_sch_pdu_nr.h
+++ b/lib/include/srslte/mac/mac_sch_pdu_nr.h
@@ -42,6 +42,7 @@ public:
     LONG_TRUNC_BSR  = 0b111100,
     CCCH_SIZE_48    = 0b110100,
     CCCH_SIZE_64    = 0b000000,
+    SE_PHR          = 0b111001, // Single Entry PHR
 
     SHORT_BSR = 0b111101,
     LONG_BSR  = 0b111110,
@@ -63,6 +64,20 @@ public:
   uint32_t get_sdu_length();
   uint32_t get_lcid();
   uint8_t* get_sdu();
+  uint16_t get_c_rnti();
+
+  // both return the reported values as per TS 38.321, mapping to dB according to TS 38.133 Sec 10.1.17 not done here
+  uint8_t get_phr();
+  uint8_t get_pcmax();
+
+  // BSR
+  struct lcg_bsr_t {
+    uint8_t lcg_id;
+    uint8_t buffer_size;
+  };
+  lcg_bsr_t                               get_sbsr();
+  static const uint8_t                    max_num_lcg_lbsr = 8;
+  std::array<lcg_bsr_t, max_num_lcg_lbsr> get_lbsr();
 
   void set_sdu(const uint32_t lcid_, const uint8_t* payload_, const uint32_t len_);
 
diff --git a/lib/src/mac/mac_sch_pdu_nr.cc b/lib/src/mac/mac_sch_pdu_nr.cc
index c6a8afda0..1404c048d 100644
--- a/lib/src/mac/mac_sch_pdu_nr.cc
+++ b/lib/src/mac/mac_sch_pdu_nr.cc
@@ -163,6 +163,40 @@ uint8_t* mac_sch_subpdu_nr::get_sdu()
   return sdu;
 }
 
+uint16_t mac_sch_subpdu_nr::get_c_rnti()
+{
+  if (parent->is_ulsch() && lcid == CRNTI) {
+    return le16toh((uint16_t)sdu[0] << 8 | sdu[1]);
+  }
+  return 0;
+}
+
+uint8_t mac_sch_subpdu_nr::get_phr()
+{
+  if (parent->is_ulsch() && lcid == SE_PHR) {
+    return sdu[0] & 0x3f;
+  }
+  return 0;
+}
+
+uint8_t mac_sch_subpdu_nr::get_pcmax()
+{
+  if (parent->is_ulsch() && lcid == SE_PHR) {
+    return sdu[1] & 0x3f;
+  }
+  return 0;
+}
+
+mac_sch_subpdu_nr::lcg_bsr_t mac_sch_subpdu_nr::get_sbsr()
+{
+  lcg_bsr_t sbsr = {};
+  if (parent->is_ulsch() && lcid == SHORT_BSR) {
+    sbsr.lcg_id      = (sdu[0] & 0xe0) >> 5;
+    sbsr.buffer_size = sdu[0] & 0x1f;
+  }
+  return sbsr;
+}
+
 uint32_t mac_sch_subpdu_nr::sizeof_ce(uint32_t lcid, bool is_ul)
 {
   if (is_ul) {
@@ -177,6 +211,8 @@ uint32_t mac_sch_subpdu_nr::sizeof_ce(uint32_t lcid, bool is_ul)
         return 1;
       case SHORT_BSR:
         return 1;
+      case SE_PHR:
+        return 2;
       case PADDING:
         return 0;
     }
diff --git a/lib/test/mac/mac_pdu_nr_test.cc b/lib/test/mac/mac_pdu_nr_test.cc
index dea16c575..778a6394e 100644
--- a/lib/test/mac/mac_pdu_nr_test.cc
+++ b/lib/test/mac/mac_pdu_nr_test.cc
@@ -523,6 +523,48 @@ int mac_ul_sch_pdu_unpack_test5()
   return SRSLTE_SUCCESS;
 }
 
+int mac_ul_sch_pdu_unpack_test6()
+{
+  // MAC PDU with UL-SCH: CRNTI, SE PHR, SBDR and padding
+
+  // CRNTI:4601 SE PHR:ph=63 pc=52 SBSR: lcg=6 bs=0 PAD: len=0
+  uint8_t tv[] = {0x3a, 0x46, 0x01, 0x39, 0x3f, 0x34, 0x3d, 0xc0, 0x3f};
+
+  if (pcap_handle) {
+    pcap_handle->write_ul_crnti_nr(tv, sizeof(tv), PCAP_CRNTI, true, PCAP_TTI);
+  }
+
+  srslte::mac_sch_pdu_nr pdu(true);
+  pdu.unpack(tv, sizeof(tv));
+  TESTASSERT(pdu.get_num_subpdus() == 4);
+
+  // 1st C-RNTI
+  mac_sch_subpdu_nr subpdu = pdu.get_subpdu(0);
+  TESTASSERT(subpdu.get_total_length() == 3);
+  TESTASSERT(subpdu.get_sdu_length() == 2);
+  TESTASSERT(subpdu.get_lcid() == mac_sch_subpdu_nr::CRNTI);
+  TESTASSERT(subpdu.get_c_rnti() == 0x4601);
+
+  // 2nd subPDU is SE PHR
+  subpdu = pdu.get_subpdu(1);
+  TESTASSERT(subpdu.get_lcid() == mac_sch_subpdu_nr::SE_PHR);
+  TESTASSERT(subpdu.get_phr() == 63);
+  TESTASSERT(subpdu.get_pcmax() == 52);
+
+  // 3rd subPDU is SBSR
+  subpdu = pdu.get_subpdu(2);
+  TESTASSERT(subpdu.get_lcid() == mac_sch_subpdu_nr::SHORT_BSR);
+  mac_sch_subpdu_nr::lcg_bsr_t sbsr = subpdu.get_sbsr();
+  TESTASSERT(sbsr.lcg_id == 6);
+  TESTASSERT(sbsr.buffer_size == 0);
+
+  // 4th is padding
+  subpdu = pdu.get_subpdu(3);
+  TESTASSERT(subpdu.get_lcid() == mac_sch_subpdu_nr::PADDING);
+
+  return SRSLTE_SUCCESS;
+}
+
 int main(int argc, char** argv)
 {
 #if PCAP
@@ -601,6 +643,11 @@ int main(int argc, char** argv)
     return SRSLTE_ERROR;
   }
 
+  if (mac_ul_sch_pdu_unpack_test6()) {
+    fprintf(stderr, "mac_ul_sch_pdu_unpack_test6() failed.\n");
+    return SRSLTE_ERROR;
+  }
+
   if (pcap_handle) {
     pcap_handle->close();
   }