asn1: use byte buffer pool for temporary variable length field generation instead of stack array

lib/include/srsran/asn1/asn1_utils.h

@@ -13,6 +13,7 @@
 #ifndef SRSASN_COMMON_UTILS_H
 #define SRSASN_COMMON_UTILS_H
 
+#include "srsran/common/buffer_pool.h"
 #include "srsran/srslog/srslog.h"
 #include "srsran/support/srsran_assert.h"
 #include <algorithm>
@@ -21,7 +22,6 @@
 #include <cstdint>
 #include <cstring>
 #include <limits>
-#include <map>
 #include <string>
 #include <vector>
 
@@ -1320,10 +1320,12 @@ public:
   ~varlength_field_pack_guard();
 
 private:
+  using byte_array_t   = std::array<uint8_t, srsran::byte_buffer_pool::BLOCK_SIZE>;
+  using byte_array_ptr = srsran::any_pool_ptr<byte_array_t>;
+
   bit_ref        brefstart;
-  //  bit_ref  bref0;
   bit_ref*       bref_tracker;
-  uint8_t  buffer[4096];
+  byte_array_ptr buffer_ptr;
   bool           align;
 };
 

lib/include/srsran/common/buffer_pool.h

@@ -157,8 +157,10 @@ private:
   uint32_t               capacity;
 };
 
+/// Type of global byte buffer pool
 using byte_buffer_pool = concurrent_fixed_memory_pool<sizeof(byte_buffer_t)>;
 
+/// Function used to generate unique byte buffers
 inline unique_byte_buffer_t make_byte_buffer() noexcept
 {
   return std::unique_ptr<byte_buffer_t>(new (std::nothrow) byte_buffer_t());
@@ -197,12 +199,30 @@ inline unique_byte_buffer_t make_byte_buffer(const uint8_t* payload, uint32_t le
 
 namespace detail {
 
+template <typename T>
 struct byte_buffer_pool_deleter {
-  void operator()(void* ptr) { byte_buffer_pool::get_instance()->deallocate_node(ptr); }
+  void operator()(T* ptr) const { byte_buffer_pool::get_instance()->deallocate_node(ptr); }
 };
 
 } // namespace detail
 
+/// Unique ptr to global byte buffer pool
+template <typename T>
+using buffer_pool_ptr = std::unique_ptr<T, detail::byte_buffer_pool_deleter<T> >;
+
+/// Method to create unique_ptrs of type T allocated in global byte buffer pool
+template <typename T, typename... CtorArgs>
+buffer_pool_ptr<T> make_buffer_pool_obj(CtorArgs&&... args) noexcept
+{
+  static_assert(sizeof(T) <= byte_buffer_pool::BLOCK_SIZE, "pool_bounded_vector does not fit buffer pool block size");
+  void* memblock = byte_buffer_pool::get_instance()->allocate_node(sizeof(T));
+  if (memblock == nullptr) {
+    return buffer_pool_ptr<T>();
+  }
+  new (memblock) T(std::forward<CtorArgs>(args)...);
+  return buffer_pool_ptr<T>(static_cast<T*>(memblock), detail::byte_buffer_pool_deleter<T>());
+}
+
 /**
  * Class to wrap objects of type T which get allocated/deallocated using the byte_buffer_pool
  * @tparam T type of the object being allocated
@@ -230,21 +250,19 @@ public:
   template <typename... CtorArgs>
   static byte_buffer_pool_ptr<T> make(CtorArgs&&... args)
   {
-    void* memblock = byte_buffer_pool::get_instance()->allocate_node(sizeof(T));
-    if (memblock == nullptr) {
-      return byte_buffer_pool_ptr<T>();
-    }
-    new (memblock) T(std::forward<CtorArgs>(args)...);
     byte_buffer_pool_ptr<T> ret;
-    ret.ptr = std::unique_ptr<T, detail::byte_buffer_pool_deleter>(static_cast<T*>(memblock),
+    ret.ptr = make_buffer_pool_obj<T>(std::forward<CtorArgs>(args)...);
-                                                                   detail::byte_buffer_pool_deleter());
     return ret;
   };
 
 private:
-  std::unique_ptr<T, detail::byte_buffer_pool_deleter> ptr;
+  buffer_pool_ptr<T> ptr;
 };
 
+/// unique_ptr with virtual deleter, so it can be used by any pool
+template <typename T>
+using any_pool_ptr = std::unique_ptr<T, std::function<void(T*)> >;
+
 } // namespace srsran
 
 #endif // SRSRAN_BUFFER_POOL_H

lib/src/asn1/asn1_utils.cc

@@ -1412,10 +1412,15 @@ SRSASN_CODE ext_groups_unpacker_guard::unpack(cbit_ref& bref)
      Open Field
 *********************/
 
-varlength_field_pack_guard::varlength_field_pack_guard(bit_ref& bref, bool align_)
+varlength_field_pack_guard::varlength_field_pack_guard(bit_ref& bref, bool align_) :
+  buffer_ptr(srsran::make_buffer_pool_obj<byte_array_t>())
 {
+  if (buffer_ptr == nullptr) {
+    // failed to allocate from global byte buffer pool. Fallback to malloc
+    buffer_ptr = std::unique_ptr<byte_array_t>(new byte_array_t());
+  }
   brefstart    = bref;
-  bref         = bit_ref(&buffer[0], sizeof(buffer));
+  bref         = bit_ref(buffer_ptr->data(), buffer_ptr->size());
   bref_tracker = &bref;
   align        = align_;
 }
@@ -1423,16 +1428,15 @@ varlength_field_pack_guard::varlength_field_pack_guard(bit_ref& bref, bool align
 varlength_field_pack_guard::~varlength_field_pack_guard()
 {
   // fill the spare bits
-  const bit_ref bref0    = bit_ref(&buffer[0], sizeof(buffer));
+  uint32_t leftover = 7 - ((bref_tracker->distance() - (uint32_t)1) % (uint32_t)8);
-  uint32_t      leftover = 7 - ((bref_tracker->distance(bref0) - (uint32_t)1) % (uint32_t)8);
   bref_tracker->pack(0, leftover);
 
   // check how many bytes were written in total
-  uint32_t nof_bytes = bref_tracker->distance(bref0) / (uint32_t)8;
+  uint32_t nof_bytes = bref_tracker->distance() / (uint32_t)8;
-  if (nof_bytes > sizeof(buffer)) {
+  if (nof_bytes > buffer_ptr->size()) {
     log_error("The packed variable sized field is too long for the reserved buffer (%zd > %zd)",
               (size_t)nof_bytes,
-              sizeof(buffer));
+              buffer_ptr->size());
   }
 
   // go back in time to pack length
@@ -1440,7 +1444,7 @@ varlength_field_pack_guard::~varlength_field_pack_guard()
 
   // pack encoded bytes
   for (uint32_t i = 0; i < nof_bytes; ++i) {
-    brefstart.pack(buffer[i], 8);
+    brefstart.pack((*buffer_ptr)[i], 8);
   }
   *bref_tracker = brefstart;
 }

lib/test/asn1/asn1_utils_test.cc

@@ -644,6 +644,21 @@ int test_big_integers()
   return 0;
 }
 
+void test_varlength_field_pack()
+{
+  uint8_t buffer[128];
+  bit_ref bref(&buffer[0], sizeof(buffer));
+  TESTASSERT_EQ(SRSRAN_SUCCESS, bref.pack(0, 1));
+  TESTASSERT_EQ(1, bref.distance());
+  {
+    varlength_field_pack_guard guard(bref);
+    TESTASSERT_EQ(0, bref.distance());
+    bref.pack(0, 8);
+    TESTASSERT_EQ(1, bref.distance_bytes());
+  }
+  TESTASSERT_EQ(17, bref.distance()); // accounts for length determinant and 1 byte of data
+}
+
 int main()
 {
   // Setup the log spy to intercept error and warning log entries.
@@ -672,6 +687,7 @@ int main()
   TESTASSERT(test_copy_ptr() == 0);
   TESTASSERT(test_enum() == 0);
   TESTASSERT(test_big_integers() == 0);
+  test_varlength_field_pack();
   //  TESTASSERT(test_json_writer()==0);
 
   srslog::flush();