/*

 * This file is part of PowerDNS or dnsdist.

 * Copyright -- PowerDNS.COM B.V. and its contributors

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of version 2 of the GNU General Public License as

 * published by the Free Software Foundation.

 *

 * In addition, for the avoidance of any doubt, permission is granted to

 * link this program with OpenSSL and to (re)distribute the binaries

 * produced as the result of such linking.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#include "dnsdist-dynbpf.hh"

std::vector<std::shared_ptr<DynBPFFilter>> g_dynBPFFilters;

bool DynBPFFilter::block(const ComboAddress& addr, const struct timespec& until)

{

  bool inserted = false;

  auto data = d_data.lock();

  if (data->d_excludedSubnets.match(addr)) {

    /* do not add a block for excluded subnets */

    return inserted;

  }

  auto entriesIt = data->d_entries.find(addr);

  if (entriesIt != data->d_entries.end()) {

    if (entriesIt->d_until < until) {

      data->d_entries.replace(entriesIt, BlockEntry(addr, until));

    }

  }

  else {

    data->d_bpf->block(addr, BPFFilter::MatchAction::Drop);

    data->d_entries.insert(BlockEntry(addr, until));

    inserted = true;

  }

  return inserted;

}

void DynBPFFilter::purgeExpired(const struct timespec& now)

{

  auto data = d_data.lock();

  using ordered_until = boost::multi_index::nth_index<container_t, 1>::type;

  ordered_until& orderedUntilIndex = boost::multi_index::get<1>(data->d_entries);

  for (auto orderedUntilIt = orderedUntilIndex.begin(); orderedUntilIt != orderedUntilIndex.end();) {

    if (orderedUntilIt->d_until < now) {

      ComboAddress addr = orderedUntilIt->d_addr;

      orderedUntilIt = orderedUntilIndex.erase(orderedUntilIt);

      data->d_bpf->unblock(addr);

    }

    else {

      break;

    }

  }

}

std::vector<std::tuple<ComboAddress, uint64_t, struct timespec>> DynBPFFilter::getAddrStats()

{

  std::vector<std::tuple<ComboAddress, uint64_t, struct timespec>> result;

  auto data = d_data.lock();

  if (!data->d_bpf) {

    return result;

  }

  const auto& stats = data->d_bpf->getAddrStats();

  result.reserve(stats.size());

  for (const auto& stat : stats) {

    const auto entriesIt = data->d_entries.find(stat.first);

    if (entriesIt != data->d_entries.end()) {

      result.emplace_back(stat.first, stat.second, entriesIt->d_until);

    }

  }

  return result;

}