lokinet/llarp/util/bencode.cpp

#include <util/bencode.h>
#include <util/logging/logger.hpp>
#include <cstdlib>
#include <cinttypes>
#include <cstdio>

bool
bencode_read_integer(struct llarp_buffer_t* buffer, uint64_t* result)
{
  size_t len;
  if(*buffer->cur != 'i')
    return false;

  char numbuf[32];

  buffer->cur++;

  len = buffer->read_until('e', (byte_t*)numbuf, sizeof(numbuf) - 1);
  if(!len)
  {
    return false;
  }

  buffer->cur++;

  numbuf[len] = '\0';
  *result     = std::strtoull(numbuf, nullptr, 10);
  return true;
}

bool
bencode_read_string(llarp_buffer_t* buffer, llarp_buffer_t* result)
{
  char numbuf[10];

  size_t len = buffer->read_until(':', (byte_t*)numbuf, sizeof(numbuf) - 1);
  if(!len)
    return false;

  numbuf[len]   = '\0';
  const int num = atoi(numbuf);
  if(num < 0)
  {
    return false;
  }

  const size_t slen = num;

  buffer->cur++;

  len = buffer->size_left();
  if(len < slen)
  {
    return false;
  }

  result->base = buffer->cur;
  result->cur  = buffer->cur;
  result->sz   = slen;
  buffer->cur += slen;
  return true;
}

bool
bencode_write_bytestring(llarp_buffer_t* buff, const void* data, size_t sz)
{
  if(!buff->writef("%zu:", sz))
  {
    return false;
  }
  return buff->write(reinterpret_cast< const char* >(data),
                     reinterpret_cast< const char* >(data) + sz);
}

bool
bencode_write_uint64(llarp_buffer_t* buff, uint64_t i)
{
// NetBSDs also do this shit in long mode, wouldn't be surprised
// if all the BSDs do by default
#if !defined(__LP64__) || (__APPLE__ && __MACH__) || (__NetBSD__) \
    || (__OpenBSD__)
  if(!buff->writef("i%llu", i))
#else
  if(!buff->writef("i%lu", i))
#endif
  {
    return false;
  }

  static const char letter[1] = {'e'};
  assert(std::distance(std::begin(letter), std::end(letter)) == 1);
  return buff->write(std::begin(letter), std::end(letter));
}

bool
bencode_write_version_entry(llarp_buffer_t* buff)
{
  return buff->writef("1:vi%de", LLARP_PROTO_VERSION);
}

bool
bencode_start_list(llarp_buffer_t* buff)
{
  static const char letter[1] = {'l'};
  assert(std::distance(std::begin(letter), std::end(letter)) == 1);
  return buff->write(std::begin(letter), std::end(letter));
}

bool
bencode_start_dict(llarp_buffer_t* buff)
{
  static const char letter[1] = {'d'};
  assert(std::distance(std::begin(letter), std::end(letter)) == 1);
  return buff->write(std::begin(letter), std::end(letter));
}

bool
bencode_end(llarp_buffer_t* buff)
{
  static const char letter[1] = {'e'};
  assert(std::distance(std::begin(letter), std::end(letter)) == 1);
  return buff->write(std::begin(letter), std::end(letter));
}