add packing for CCCH over UL-SCH for MAC NR

lib/include/srslte/common/mac_nr_pdu.h

@@ -37,6 +37,7 @@ public:
   // 3GPP 38.321 v15.3.0 Combined Tables 6.2.1-1, 6.2.1-2
   typedef enum {
     // Values for DL-SCH
+    CCCH       = 0b000000,
     DRX_CMD    = 0b111100,
     TA_CMD     = 0b111101,
     CON_RES_ID = 0b111110,
@@ -45,12 +46,13 @@ public:
     CRNTI           = 0b111010,
     SHORT_TRUNC_BSR = 0b111011,
     LONG_TRUNC_BSR  = 0b111100,
+    CCCH_SIZE_48    = 0b110100,
+    CCCH_SIZE_64    = 0b000000,
 
     SHORT_BSR = 0b111101,
     LONG_BSR  = 0b111110,
 
     // Common
-    CCCH    = 0b000000,
     PADDING = 0b111111,
   } nr_lcid_sch_t;
 
@@ -59,6 +61,7 @@ public:
   nr_lcid_sch_t get_type();
   bool          is_sdu();
   bool          is_var_len_ce();
+  bool          is_ul_ccch();
 
   uint32_t read_subheader(const uint8_t* ptr);
   uint32_t get_total_length();
@@ -103,7 +106,7 @@ public:
   uint32_t get_remaing_len();
 
 private:
-  uint32_t size_header_sdu(const uint32_t nbytes);
+  uint32_t size_header_sdu(const uint32_t lcid_, const uint32_t nbytes);
 
   bool                                              ulsch = false;
   std::vector<mac_nr_sch_subpdu>                    subpdus;

lib/src/common/mac_nr_pdu.cc

@@ -53,7 +53,7 @@ uint32_t mac_nr_sch_subpdu::read_subheader(const uint8_t* ptr)
   ptr++;
   header_length = 1;
 
-  if (is_sdu() || is_var_len_ce()) {
+  if ((is_sdu() || is_var_len_ce()) && not is_ul_ccch()) {
     // Read first length byte
     sdu_length = (uint32_t)*ptr;
     ptr++;
@@ -76,8 +76,15 @@ void mac_nr_sch_subpdu::set_sdu(const uint32_t lcid_, const uint8_t* payload_, c
 {
   lcid          = lcid_;
   sdu           = const_cast<uint8_t*>(payload_);
+  header_length = is_ul_ccch() ? 1 : 2;
   sdu_length    = len_;
-  header_length = 2;
+  if (is_ul_ccch()) {
+    F_bit      = false;
+    sdu_length = sizeof_ce(lcid, parent->is_ulsch());
+    if (len_ != static_cast<uint32_t>(sdu_length)) {
+      fprintf(stderr, "Invalid SDU length of UL-SCH SDU (%d != %d)\n", len_, sdu_length);
+    }
+  }
 
   if (sdu_length >= 256) {
     F_bit = true;
@@ -155,6 +162,10 @@ uint32_t mac_nr_sch_subpdu::sizeof_ce(uint32_t lcid, bool is_ul)
 {
   if (is_ul) {
     switch (lcid) {
+      case CCCH_SIZE_48:
+        return 6;
+      case CCCH_SIZE_64:
+        return 8;
       case CRNTI:
         return 2;
       case SHORT_TRUNC_BSR:
@@ -179,6 +190,11 @@ uint32_t mac_nr_sch_subpdu::sizeof_ce(uint32_t lcid, bool is_ul)
   return 0;
 }
 
+inline bool mac_nr_sch_subpdu::is_ul_ccch()
+{
+  return (parent->is_ulsch() && (lcid == CCCH_SIZE_48 || lcid == CCCH_SIZE_64));
+}
+
 void mac_nr_sch_pdu::pack()
 {
   // SDUs are written in place, only add padding if needed
@@ -231,13 +247,17 @@ void mac_nr_sch_pdu::init_tx(byte_buffer_t* buffer_, uint32_t pdu_len_, bool uls
   ulsch         = ulsch_;
 }
 
-uint32_t mac_nr_sch_pdu::size_header_sdu(const uint32_t nbytes)
+uint32_t mac_nr_sch_pdu::size_header_sdu(const uint32_t lcid, const uint32_t nbytes)
 {
+  if (ulsch && (lcid == mac_nr_sch_subpdu::CCCH_SIZE_48 || lcid == mac_nr_sch_subpdu::CCCH_SIZE_64)) {
+    return 1;
+  } else {
     if (nbytes < 256) {
       return 2;
     } else {
       return 3;
     }
+  }
 }
 
 uint32_t mac_nr_sch_pdu::get_remaing_len()
@@ -247,7 +267,7 @@ uint32_t mac_nr_sch_pdu::get_remaing_len()
 
 uint32_t mac_nr_sch_pdu::add_sdu(const uint32_t lcid_, const uint8_t* payload_, const uint32_t len_)
 {
-  int header_size = size_header_sdu(len_);
+  int header_size = size_header_sdu(lcid_, len_);
 
   if (header_size + len_ > remaining_len) {
     printf("Header and SDU exceed space in PDU (%d > %d).\n", header_size + len_, remaining_len);

lib/test/common/mac_nr_pdu_test.cc

@@ -289,6 +289,54 @@ int mac_ul_sch_pdu_unpack_test1()
   return SRSLTE_SUCCESS;
 }
 
+int mac_ul_sch_pdu_unpack_and_pack_test2()
+{
+  // MAC PDU with UL-SCH (for UL-CCCH) subheader
+  // Bit 1-8
+  // |   |   |   |   |   |   |   |   |
+  // | R | R |         LCID          |  Octet 1
+
+  // TV1 - MAC PDU with short subheader for CCCH, MAC SDU length is 8 B, total PDU is 10 B
+  uint8_t mac_ul_sch_pdu_1[] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88};
+
+  if (pcap_handle) {
+    pcap_handle->write_ul_crnti(mac_ul_sch_pdu_1, sizeof(mac_ul_sch_pdu_1), PCAP_CRNTI, true, PCAP_TTI);
+  }
+
+  srslte::mac_nr_sch_pdu pdu(true);
+  pdu.unpack(mac_ul_sch_pdu_1, sizeof(mac_ul_sch_pdu_1));
+  TESTASSERT(pdu.get_num_subpdus() == 1);
+
+  mac_nr_sch_subpdu subpdu = pdu.get_subpdu(0);
+  TESTASSERT(subpdu.get_total_length() == 9);
+  TESTASSERT(subpdu.get_sdu_length() == 8);
+  TESTASSERT(subpdu.get_lcid() == 0);
+
+  // pack PDU again
+  byte_buffer_t tx_buffer;
+
+  srslte::mac_nr_sch_pdu tx_pdu;
+  tx_pdu.init_tx(&tx_buffer, sizeof(mac_ul_sch_pdu_1), true);
+
+  // Add SDU part of TV from above
+  tx_pdu.add_sdu(0, &mac_ul_sch_pdu_1[1], 8);
+
+  TESTASSERT(tx_pdu.get_remaing_len() == 0);
+  TESTASSERT(tx_buffer.N_bytes == sizeof(mac_ul_sch_pdu_1));
+  TESTASSERT(memcmp(tx_buffer.msg, mac_ul_sch_pdu_1, tx_buffer.N_bytes) == 0);
+
+  if (pcap_handle) {
+    pcap_handle->write_ul_crnti(tx_buffer.msg, tx_buffer.N_bytes, PCAP_CRNTI, true, PCAP_TTI);
+  }
+
+  srslte::log_filter log("MAC");
+  log.set_level(srslte::LOG_LEVEL_DEBUG);
+  log.set_hex_limit(100000);
+  log.info_hex(tx_buffer.msg, tx_buffer.N_bytes, "Generated MAC PDU (%d B)\n", tx_buffer.N_bytes);
+
+  return SRSLTE_SUCCESS;
+}
+
 int main(int argc, char** argv)
 {
 #if PCAP
@@ -326,5 +374,10 @@ int main(int argc, char** argv)
     return SRSLTE_ERROR;
   }
 
+  if (mac_ul_sch_pdu_unpack_and_pack_test2()) {
+    fprintf(stderr, "mac_ul_sch_pdu_unpack_and_pack_test2() failed.\n");
+    return SRSLTE_ERROR;
+  }
+
   return SRSLTE_SUCCESS;
 }