adnl-proxy.cpp

/*
    This file is part of TON Blockchain source code.

    TON Blockchain is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License
    as published by the Free Software Foundation; either version 2
    of the License, or (at your option) any later version.

    TON Blockchain 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 TON Blockchain.  If not, see <http://www.gnu.org/licenses/>.

    In addition, as a special exception, the copyright holders give permission
    to link the code of portions of this program with the OpenSSL library.
    You must obey the GNU General Public License in all respects for all
    of the code used other than OpenSSL. If you modify file(s) with this
    exception, you may extend this exception to your version of the file(s),
    but you are not obligated to do so. If you do not wish to do so, delete this
    exception statement from your version. If you delete this exception statement
    from all source files in the program, then also delete it here.

    Copyright 2017-2020 Telegram Systems LLP
*/
#include "td/actor/actor.h"
#include "td/utils/buffer.h"
#include "td/utils/port/IPAddress.h"
#include "td/net/UdpServer.h"
#include "td/utils/port/signals.h"
#include "td/utils/OptionParser.h"
#include "td/utils/FileLog.h"
#include "td/utils/port/path.h"
#include "td/utils/port/user.h"
#include "td/utils/filesystem.h"
#include "td/utils/overloaded.h"
#include "common/checksum.h"
#include "common/errorcode.h"
#include "tl-utils/tl-utils.hpp"
#include "auto/tl/ton_api_json.h"
#include "adnl-proxy-types.h"
#include "adnl-received-mask.h"
#include <map>
#include "git.h"

#if TD_DARWIN || TD_LINUX
#include <unistd.h>
#endif

namespace ton {

namespace adnl {

namespace {
td::int32 start_time() {
  static td::int32 t = static_cast<td::int32>(td::Clocks::system());
  return t;
}
}  // namespace

class Receiver : public td::actor::Actor {
 public:
  void start_up() override;
  void receive_common(td::IPAddress addr, td::BufferSlice data);
  void receive_from_client(td::IPAddress addr, td::BufferSlice data);
  void receive_to_client(td::IPAddress addr, td::BufferSlice data);

  Receiver(td::uint16 in_port, td::uint16 out_port, std::shared_ptr<AdnlProxy> proxy, td::IPAddress client_addr)
      : in_port_(in_port), out_port_(out_port), proxy_(std::move(proxy)), addr_(client_addr) {
  }

 private:
  td::uint16 in_port_;
  td::uint16 out_port_;
  std::shared_ptr<ton::adnl::AdnlProxy> proxy_;
  td::IPAddress addr_;
  td::actor::ActorOwn<td::UdpServer> out_udp_server_;
  td::actor::ActorOwn<td::UdpServer> in_udp_server_;

  td::int32 client_start_time_{0};
  td::uint64 out_seqno_{0};
  AdnlReceivedMaskVersion received_;
};

void Receiver::start_up() {
  class Callback : public td::UdpServer::Callback {
   public:
    Callback(td::actor::ActorId<Receiver> manager, td::uint32 mode) : manager_(std::move(manager)), mode_(mode) {
    }

   private:
    td::actor::ActorId<Receiver> manager_;
    const td::uint32 mode_;
    void on_udp_message(td::UdpMessage udp_message) override {
      if (udp_message.error.is_error()) {
        LOG(INFO) << "receifed udp message with error: " << udp_message.error;
        return;
      }
      if (mode_ == 0) {
        td::actor::send_closure_later(manager_, &Receiver::receive_common, udp_message.address,
                                      std::move(udp_message.data));
      } else if (mode_ == 1) {
        td::actor::send_closure_later(manager_, &Receiver::receive_from_client, udp_message.address,
                                      std::move(udp_message.data));
      } else {
        td::actor::send_closure_later(manager_, &Receiver::receive_to_client, udp_message.address,
                                      std::move(udp_message.data));
      }
    }
  };

  if (in_port_ == out_port_) {
    auto X = td::UdpServer::create("udp server", in_port_, std::make_unique<Callback>(actor_id(this), 0));
    X.ensure();
    in_udp_server_ = X.move_as_ok();
  } else {
    auto X = td::UdpServer::create("udp server", in_port_, std::make_unique<Callback>(actor_id(this), 1));
    X.ensure();
    in_udp_server_ = X.move_as_ok();
    X = td::UdpServer::create("udp server", out_port_, std::make_unique<Callback>(actor_id(this), 2));
    X.ensure();
    out_udp_server_ = X.move_as_ok();
  }
}

void Receiver::receive_common(td::IPAddress addr, td::BufferSlice data) {
  if (data.size() <= 32) {
    LOG(INFO) << "dropping too short packet: size=" << data.size();
    return;
  }

  if (proxy_->id().as_slice() == data.as_slice().truncate(32)) {
    receive_from_client(addr, std::move(data));
  } else {
    receive_to_client(addr, std::move(data));
  }
}

void Receiver::receive_from_client(td::IPAddress addr, td::BufferSlice data) {
  auto F = proxy_->decrypt(std::move(data));
  if (F.is_error()) {
    LOG(INFO) << "proxy: failed to decrypt message from client: " << F.move_as_error();
    return;
  }
  auto f = F.move_as_ok();
  if (f.flags & (1 << 16)) {
    LOG(INFO) << "proxy: dropping message from client: flag 16 is set";
    return;
  }

  if (f.date) {
    if (f.date + 60.0 < td::Clocks::system() || f.date - 60.0 > td::Clocks::system()) {
      LOG(INFO) << "proxy: dropping message from client: date mismatch";
      return;
    }
  }

  if ((f.flags & 6) == 6) {
    if (received_.packet_is_delivered(f.adnl_start_time, f.seqno)) {
      LOG(INFO) << "proxy: dropping message from client: duplicate packet (or old seqno/start_time)";
      return;
    }
    received_.deliver_packet(f.adnl_start_time, f.seqno);
  }

  if (f.flags & (1 << 17)) {
    auto F = fetch_tl_object<ton_api::adnl_ProxyControlPacket>(std::move(f.data), true);
    if (F.is_error()) {
      LOG(INFO) << this << ": dropping proxy packet: bad control packet: " << F.move_as_error();
      return;
    }
    ton_api::downcast_call(*F.move_as_ok().get(),
                           td::overloaded(
                               [&](const ton_api::adnl_proxyControlPacketPing &f) {
                                 auto data = create_serialize_tl_object<ton_api::adnl_proxyControlPacketPong>(f.id_);
                                 AdnlProxy::Packet p;
                                 p.flags = 6 | (1 << 16) | (1 << 17);
                                 if (addr.is_valid() && addr.is_ipv4()) {
                                   p.flags |= 1;
                                   p.ip = addr.get_ipv4();
                                   p.port = static_cast<td::uint16>(addr.get_port());
                                 } else {
                                   p.ip = 0;
                                   p.port = 0;
                                 }
                                 p.data = std::move(data);
                                 p.adnl_start_time = start_time();
                                 p.seqno = out_seqno_;

                                 auto enc = proxy_->encrypt(std::move(p));

                                 td::UdpMessage M;
                                 M.address = addr;
                                 M.data = std::move(enc);

                                 td::actor::send_closure(
                                     in_udp_server_.empty() ? out_udp_server_.get() : in_udp_server_.get(),
                                     &td::UdpServer::send, std::move(M));
                               },
                               [&](const ton_api::adnl_proxyControlPacketPong &f) {},
                               [&](const ton_api::adnl_proxyControlPacketRegister &f) {
                                 if (f.ip_ == 0 && f.port_ == 0) {
                                   if (addr.is_valid() && addr.is_ipv4()) {
                                     addr_ = addr;
                                   }
                                 } else {
                                   td::IPAddress a;
                                   auto S = a.init_host_port(td::IPAddress::ipv4_to_str(f.ip_), f.port_);
                                   if (S.is_ok()) {
                                     addr_ = a;
                                   } else {
                                     LOG(INFO) << "failed to init remote addr: " << S.move_as_error();
                                   }
                                 }
                               }));
    return;
  }

  if (!(f.flags & 1)) {
    LOG(INFO) << this << ": dropping proxy packet: no destination";
    return;
  }

  td::IPAddress a;
  if (a.init_ipv4_port(td::IPAddress::ipv4_to_str(f.ip), f.port).is_error()) {
    LOG(INFO) << this << ": dropping proxy packet: invalid destination";
    return;
  }
  if (!a.is_valid()) {
    LOG(INFO) << this << ": dropping proxy packet: invalid destination";
    return;
  }

  td::UdpMessage M;
  M.address = a;
  M.data = std::move(f.data);
  LOG(DEBUG) << this << ": proxying DOWN packet of length " << M.data.size() << " to " << a;

  td::actor::send_closure(out_udp_server_.empty() ? in_udp_server_.get() : out_udp_server_.get(), &td::UdpServer::send,
                          std::move(M));
}

void Receiver::receive_to_client(td::IPAddress addr, td::BufferSlice data) {
  LOG(DEBUG) << "proxying to " << addr_;
  if (!addr_.is_valid() || !addr_.is_ipv4() || !addr_.get_ipv4()) {
    LOG(INFO) << this << ": dropping external packet: client not inited";
    return;
  }

  AdnlProxy::Packet p;
  p.flags = (1 << 16);
  if (addr.is_valid() && addr.is_ipv4()) {
    p.flags |= 1;
    p.ip = addr.get_ipv4();
    p.port = static_cast<td::uint16>(addr.get_port());
  } else {
    p.ip = 0;
    p.port = 0;
  }
  p.flags |= 2;
  p.adnl_start_time = start_time();
  p.flags |= 4;
  p.seqno = ++out_seqno_;
  p.data = std::move(data);

  LOG(DEBUG) << this << ": proxying UP packet of length " << p.data.size() << " to " << addr_;

  td::UdpMessage M;
  M.address = addr_;
  M.data = proxy_->encrypt(std::move(p));

  td::actor::send_closure(in_udp_server_.empty() ? out_udp_server_.get() : in_udp_server_.get(), &td::UdpServer::send,
                          std::move(M));
}

}  // namespace adnl

}  // namespace ton

std::atomic<bool> rotate_logs_flags{false};
void force_rotate_logs(int sig) {
  rotate_logs_flags.store(true);
}

int main(int argc, char *argv[]) {
  SET_VERBOSITY_LEVEL(verbosity_INFO);

  td::set_default_failure_signal_handler().ensure();

  std::vector<td::actor::ActorOwn<ton::adnl::Receiver>> x;
  std::unique_ptr<td::LogInterface> logger_;
  SCOPE_EXIT {
    td::log_interface = td::default_log_interface;
  };

  std::string config = "/var/ton-work/etc/adnl-proxy.conf.json";

  td::OptionParser p;
  p.set_description("validator or full node for TON network");
  p.add_option('v', "verbosity", "set verbosity level", [&](td::Slice arg) {
    int v = VERBOSITY_NAME(FATAL) + (td::to_integer<int>(arg));
    SET_VERBOSITY_LEVEL(v);
  });
  p.add_option('V', "version", "shows adnl-proxy build information", [&]() {
    std::cout << "adnl-proxy build information: [ Commit: " << GitMetadata::CommitSHA1() << ", Date: " << GitMetadata::CommitDate() << "]\n";
    std::exit(0);
  });
  p.add_option('h', "help", "prints_help", [&]() {
    char b[10240];
    td::StringBuilder sb(td::MutableSlice{b, 10000});
    sb << p;
    std::cout << sb.as_cslice().c_str();
    std::exit(2);
  });
  p.add_option('c', "config", "config file", [&](td::Slice arg) { config = arg.str(); });
  p.add_option('d', "daemonize", "set SIGHUP", [&]() {
#if TD_DARWIN || TD_LINUX
    close(0);
    setsid();
#endif
    td::set_signal_handler(td::SignalType::HangUp, force_rotate_logs).ensure();
  });
  p.add_checked_option('l', "logname", "log to file", [&](td::Slice fname) {
    auto F = std::make_unique<td::FileLog>();
    TRY_STATUS(F->init(fname.str(), std::numeric_limits<td::int64>::max(), true));
    logger_ = std::move(F);
    td::log_interface = logger_.get();
    return td::Status::OK();
  });
  td::uint32 threads = 7;
  p.add_checked_option(
      't', "threads", PSTRING() << "number of threads (default=" << threads << ")", [&](td::Slice fname) {
        td::int32 v;
        try {
          v = std::stoi(fname.str());
        } catch (...) {
          return td::Status::Error(ton::ErrorCode::error, "bad value for --threads: not a number");
        }
        if (v < 1 || v > 256) {
          return td::Status::Error(ton::ErrorCode::error, "bad value for --threads: should be in range [1..256]");
        }
        threads = v;
        return td::Status::OK();
      });
  p.add_checked_option('u', "user", "change user", [&](td::Slice user) { return td::change_user(user.str()); });

  p.run(argc, argv).ensure();

  td::actor::Scheduler scheduler({threads});

  auto R = [&]() -> td::Status {
    TRY_RESULT_PREFIX(conf_data, td::read_file(config), "failed to read: ");
    TRY_RESULT_PREFIX(conf_json, td::json_decode(conf_data.as_slice()), "failed to parse json: ");

    ton::ton_api::engine_adnlProxy_config conf;
    TRY_STATUS_PREFIX(ton::ton_api::from_json(conf, conf_json.get_object()), "json does not fit TL scheme: ");

    if (!conf.ports_.size()) {
      return td::Status::Error("empty config");
    }

    for (auto &y : conf.ports_) {
      auto in_port = static_cast<td::uint16>(y->in_port_);
      auto out_port = static_cast<td::uint16>(y->out_port_);
      if (!y->proxy_type_) {
        return td::Status::Error("empty proxy type");
      }
      TRY_RESULT(proxy, ton::adnl::AdnlProxy::create(*y->proxy_type_.get()));
      td::IPAddress a;
      if (y->dst_ip_ || y->dst_port_) {
        a.init_ipv4_port(td::IPAddress::ipv4_to_str(y->dst_ip_), static_cast<td::uint16>(y->dst_port_)).ensure();
      }

      scheduler.run_in_context([&] {
        x.push_back(td::actor::create_actor<ton::adnl::Receiver>("adnl-proxy", in_port, out_port, std::move(proxy), a));
      });
    }

    return td::Status::OK();
  }();

  if (R.is_error()) {
    LOG(FATAL) << "bad config: " << R.move_as_error();
  }

  while (scheduler.run(1)) {
    if (rotate_logs_flags.exchange(false)) {
      if (td::log_interface) {
        td::log_interface->rotate();
      }
    }
  }
}