CCats/daemon/src/Server.cpp

#include "../include/Server.h"
#include "../include/base64.h"

#include <iostream>
#include <json/json.h>

using namespace boost::asio;
using ip::tcp;

/***************
 * con_handler *
 ***************/

con_handler::con_handler(
    basic_socket_acceptor<ip::tcp>::executor_type &io_service)
    : sock(io_service) {}

con_handler::~con_handler() {}

con_handler::pointer
con_handler::create(basic_socket_acceptor<ip::tcp>::executor_type &io_service) {
  return pointer(new con_handler(io_service));
}

tcp::socket &con_handler::socket() { return sock; }

void con_handler::start() {

  sock.async_read_some(buffer(data, max_length),
                       boost::bind(&con_handler::handle_read_version,
                                   shared_from_this(), placeholders::error,
                                   placeholders::bytes_transferred));
}

void con_handler::handle_read(const boost::system::error_code &err,
                              size_t bytes_transferred) {
  if (!err) {
    std::cout << this->data << std::endl;
  } else {
    std::cerr << "error: " << err.message() << std::endl;
    sock.close();
  }
}

void con_handler::handle_read_version(const boost::system::error_code &err,
                                      size_t bytes_transferred) {
  if (!err) {
    // set up json stuff
    JSONCPP_STRING err;
    Json::Value root;
    Json::CharReaderBuilder builder;
    const std::unique_ptr<Json::CharReader> reader(builder.newCharReader());

    // parse data
    if (!reader->parse(this->data, this->data + bytes_transferred, &root,
                       &err)) {
      std::cerr << "Json error: " << err << std::endl << "data: " << this->data;
      sock.close();
    }

    // create answer
    Json::Value answer;
    Json::StreamWriterBuilder stringBuilder;

    answer["version"] = this->protocolVersion;

    // check version string
    if (root["version"].asString().compare(this->protocolVersion) == 0) {
      answer["accept"] = true;
      const std::string answerString = Json::writeString(stringBuilder, answer);

      // read next data
      sock.async_read_some(buffer(data, max_length),
                           boost::bind(&con_handler::handle_read_login,
                                       shared_from_this(), placeholders::error,
                                       placeholders::bytes_transferred));

      // send answer
      sock.async_write_some(buffer(answerString, max_length),
                            boost::bind(&con_handler::handle_write,
                                        shared_from_this(), placeholders::error,
                                        placeholders::bytes_transferred));
    } else {
      answer["accept"] = false;
      const std::string answerString = Json::writeString(stringBuilder, answer);

      // send answer
      sock.async_write_some(buffer(answerString, max_length),
                            boost::bind(&con_handler::handle_write,
                                        shared_from_this(), placeholders::error,
                                        placeholders::bytes_transferred));
      // close connection
      sock.close();
    }

  } else {
    std::cerr << "error: " << err.message() << std::endl;
    sock.close();
  }
}

void con_handler::handle_read_login(const boost::system::error_code &err,
                                    size_t bytes_transferred) {
  if (!err) {
    // set up json stuff
    JSONCPP_STRING err;
    Json::Value root;
    Json::CharReaderBuilder builder;
    const std::unique_ptr<Json::CharReader> reader(builder.newCharReader());

    // parse data
    if (!reader->parse(this->data, this->data + bytes_transferred, &root,
                       &err)) {
      std::cerr << "Json error: " << err << std::endl << "data: " << this->data;
      sock.close();
    }

    Json::Value answer;
    Json::StreamWriterBuilder stringBuilder;

    // user credentials
    // TODO check user credentials!!!
    if (root["user"].asString().compare("user") == 0 &&
        root["pass"].asString().compare("pass") == 0) {
      answer["accept"] = true;
      const std::string answerString = Json::writeString(stringBuilder, answer);

      // read next data
      sock.async_read_some(buffer(data, max_length),
                           boost::bind(&con_handler::handle_read_command,
                                       shared_from_this(), placeholders::error,
                                       placeholders::bytes_transferred));

      // send answer
      sock.async_write_some(buffer(answerString, max_length),
                            boost::bind(&con_handler::handle_write,
                                        shared_from_this(), placeholders::error,
                                        placeholders::bytes_transferred));
    } else {
      answer["accept"] = false;
      const std::string answerString = Json::writeString(stringBuilder, answer);

      // send answer
      sock.async_write_some(buffer(answerString, max_length),
                            boost::bind(&con_handler::handle_write,
                                        shared_from_this(), placeholders::error,
                                        placeholders::bytes_transferred));
      // close connection
      sock.close();
    }

  } else {
    std::cerr << "error: " << err.message() << std::endl;
    sock.close();
  }
}

void con_handler::handle_read_command(const boost::system::error_code &err,
                                      size_t bytes_transferred) {
  if (!err) {
    // set up json stuff
    JSONCPP_STRING err;
    Json::Value root;
    Json::CharReaderBuilder builder;
    const std::unique_ptr<Json::CharReader> reader(builder.newCharReader());

    // parse data
    if (!reader->parse(this->data, this->data + bytes_transferred, &root,
                       &err)) {
      std::cerr << "Json error: " << err << std::endl << "data: " << this->data;
      sock.close();
    }

    Json::Value answer;
    Json::StreamWriterBuilder stringBuilder;

    // check command
    if (root["command"].asString().compare("status") == 0) {
      // read next data
      sock.async_read_some(buffer(data, max_length),
                           boost::bind(&con_handler::handle_read_command,
                                       shared_from_this(), placeholders::error,
                                       placeholders::bytes_transferred));

      answer["command"] = "status";

      // TODO answer a real status message
      std::string response;
      if (this->getFile.is_open() && this->putFile.is_open()) {
        response = "download and upload running";
      } else if (this->putFile.is_open()) {
        response = "upload running";
      } else if (this->getFile.is_open()) {
        response = "download running";
      } else {
        response = "ok";
      }

      answer["response"] = response;
      const std::string answerString = Json::writeString(stringBuilder, answer);

      // send answer
      sock.async_write_some(buffer(answerString, max_length),
                            boost::bind(&con_handler::handle_write,
                                        shared_from_this(), placeholders::error,
                                        placeholders::bytes_transferred));
    } else if (root["command"].asString().compare("list") == 0) {
      // read next data
      sock.async_read_some(buffer(data, max_length),
                           boost::bind(&con_handler::handle_read_command,
                                       shared_from_this(), placeholders::error,
                                       placeholders::bytes_transferred));

      answer["command"] = "list";

      // TODO look for real data
      Json::Value array;
      array.append("some");
      array.append("important");
      array.append("data");
      answer["names"] = array;
      answer["remaining"] = 0;

      const std::string answerString = Json::writeString(stringBuilder, answer);
      // send answer
      sock.async_write_some(buffer(answerString, max_length),
                            boost::bind(&con_handler::handle_write,
                                        shared_from_this(), placeholders::error,
                                        placeholders::bytes_transferred));

    } else if (root["command"].asString().compare("put") == 0) {
      // read next data
      sock.async_read_some(buffer(data, max_length),
                           boost::bind(&con_handler::handle_read_command,
                                       shared_from_this(), placeholders::error,
                                       placeholders::bytes_transferred));

      answer["command"] = "put";

      if (this->putFile.is_open() && root["cancel"].asBool() == true) {
        // cancel upload
        this->putFile.close();
        std::remove(this->putFileName.c_str());

      } else if (this->putFile.is_open() &&
                 (this->putFile.tellp() == std::ios::beg ||
                  root["remaining"].asInt() == this->putFileReceived - 1)) {
        // upload chunks
        // decode base64 string
        const std::vector<char> data =
            base64::decodeVector(root["data"].asString());

        // write the vector data to the output file
        std::ostream_iterator<char> output_iterator(putFile);
        std::copy(data.begin(), data.end(), output_iterator);

        this->putFileReceived = root["remaining"].asInt();
        // close file if put sends remaining = 0
        if (this->putFileReceived == 0) {
          this->putFile.close();
        }

        answer["cancel"] = false;
        answer["received"] = this->putFileReceived;

        const std::string answerString =
            Json::writeString(stringBuilder, answer);
        // send answer
        sock.async_write_some(
            buffer(answerString, max_length),
            boost::bind(&con_handler::handle_write, shared_from_this(),
                        placeholders::error, placeholders::bytes_transferred));

      } else {
        // start upload
        const std::string filename = root["file"].asString();
        if (filename.find("/") != std::string::npos) {
          // slashes in file names are illegal
          answer["accept"] = false;

          const std::string answerString =
              Json::writeString(stringBuilder, answer);
          // send answer
          sock.async_write_some(buffer(answerString, max_length),
                                boost::bind(&con_handler::handle_write,
                                            shared_from_this(),
                                            placeholders::error,
                                            placeholders::bytes_transferred));
        } else {
          // build file path
          this->putFileName = this->fileDirectory;
          this->putFileName.append(filename);

          // open file and test if it already exists
          this->putFile.open(this->putFileName,
                             std::ios::app | std::ios::binary);
          if (this->putFile.tellp() != std::ios::beg &&
              root["file"].isString()) {
            // file already exists
            this->putFile.close();
            answer["accept"] = false;

            const std::string answerString =
                Json::writeString(stringBuilder, answer);
            // send answer
            sock.async_write_some(buffer(answerString, max_length),
                                  boost::bind(&con_handler::handle_write,
                                              shared_from_this(),
                                              placeholders::error,
                                              placeholders::bytes_transferred));
          } else {
            // accept file
            answer["accept"] = true;

            const std::string answerString =
                Json::writeString(stringBuilder, answer);
            // send answer
            sock.async_write_some(buffer(answerString, max_length),
                                  boost::bind(&con_handler::handle_write,
                                              shared_from_this(),
                                              placeholders::error,
                                              placeholders::bytes_transferred));
          }
        }
      }
    } else if (root["command"].asString().compare("get") == 0) {
      // read next data
      sock.async_read_some(buffer(data, max_length),
                           boost::bind(&con_handler::handle_read_command,
                                       shared_from_this(), placeholders::error,
                                       placeholders::bytes_transferred));

      answer["command"] = "get";

      if (this->getFile.is_open()) {
        // a get request is already being progressed
        if (root["received"].asInt() == this->getFileRemaining) {
          if (root["cancel"].asBool()) {
            // cancel get
            this->getFile.close();
          } else if (this->getFileRemaining > 0) {
            char fileBuffer[max_data_length];
            size_t read = this->getFile.readsome(fileBuffer, max_data_length);
            this->getFileRemaining--;

            // store binary data in vector because a string whould end with
            // '\0'
            std::vector<char> data;
            data.assign(fileBuffer, fileBuffer + read);

            answer["remaining"] = this->getFileRemaining;
            answer["cancel"] = false;
            answer["data"] = base64::encodeVector(data);

            const std::string answerString =
                Json::writeString(stringBuilder, answer);

            sock.async_write_some(buffer(answerString, max_length),
                                  boost::bind(&con_handler::handle_write,
                                              shared_from_this(),
                                              placeholders::error,
                                              placeholders::bytes_transferred));
          } else {
            // remaining 0 and received by client so you can close the file
            this->getFile.close();
          }
        } else {
          answer["accept"] = false;

          const std::string answerString =
              Json::writeString(stringBuilder, answer);
          // send answer
          sock.async_write_some(buffer(answerString, max_length),
                                boost::bind(&con_handler::handle_write,
                                            shared_from_this(),
                                            placeholders::error,
                                            placeholders::bytes_transferred));
        }
      } else {
        // open file
        const std::string filename = root["file"].asString();
        if (filename.find("/") != std::string::npos) {
          // slashes in file names are illegal
          answer["accept"] = false;

          const std::string answerString =
              Json::writeString(stringBuilder, answer);
          // send answer
          sock.async_write_some(buffer(answerString, max_length),
                                boost::bind(&con_handler::handle_write,
                                            shared_from_this(),
                                            placeholders::error,
                                            placeholders::bytes_transferred));
        } else {
          std::string file = this->fileDirectory;
          file.append(filename);

          this->getFile = std::ifstream(file, std::ios::ate | std::ios::binary);

          if (this->getFile.is_open() == 0) {
            // file does not exist or cannot be opened
            answer["accept"] = false;

            const std::string answerString =
                Json::writeString(stringBuilder, answer);
            // send answer
            sock.async_write_some(buffer(answerString, max_length),
                                  boost::bind(&con_handler::handle_write,
                                              shared_from_this(),
                                              placeholders::error,
                                              placeholders::bytes_transferred));
          } else {
            answer["accept"] = true;

            std::string answerString = Json::writeString(stringBuilder, answer);

            sock.async_write_some(buffer(answerString, max_length),
                                  boost::bind(&con_handler::handle_write,
                                              shared_from_this(),
                                              placeholders::error,
                                              placeholders::bytes_transferred));

            answer = Json::Value();
            answer["command"] = "get";

            // get size of file
            size_t size = this->getFile.tellg();
            this->getFile.seekg(std::ios::beg);

            char fileBuffer[max_data_length];
            size_t read = this->getFile.readsome(fileBuffer, max_data_length);
            size -= read;
            this->getFileRemaining =
                size / max_data_length + (size % max_data_length == 0 ? 0 : 1);

            // store binary data in vector because a string whould end with
            // '\0'
            std::vector<char> data;
            data.assign(fileBuffer, fileBuffer + read);

            answer["remaining"] = this->getFileRemaining;
            answer["cancel"] = false;
            answer["data"] = base64::encodeVector(data);

            answerString = Json::writeString(stringBuilder, answer);

            sock.async_write_some(buffer(answerString, max_length),
                                  boost::bind(&con_handler::handle_write,
                                              shared_from_this(),
                                              placeholders::error,
                                              placeholders::bytes_transferred));
          }
        }
      }
    } else if (root["command"].asString().compare("close") == 0) {
      answer["command"] = "close";
      answer["response"] = "bye";
      const std::string answerString = Json::writeString(stringBuilder, answer);

      // send answer
      sock.async_write_some(buffer(answerString, max_length),
                            boost::bind(&con_handler::handle_write,
                                        shared_from_this(), placeholders::error,
                                        placeholders::bytes_transferred));

      // close connection
      sock.close();
    } else {
      // TODO handle error

      // close connection
      sock.close();
    }

  } else {
    std::cerr << "error: " << err.message() << std::endl;
    sock.close();
  }
}

void con_handler::handle_write(const boost::system::error_code &err,
                               size_t bytes_transferred) {
  if (!err) {
    std::cout << "Hello World!" << std::endl;
  } else {
    std::cerr << "error: " << err.message() << std::endl;
    sock.close();
  }
}

/**********
 * Server *
 **********/

void Server::start_accept() {
  auto executor = acceptor_.get_executor();
  con_handler::pointer connection = con_handler::create(executor);
  acceptor_.async_accept(connection->socket(),
                         boost::bind(&Server::handle_accept, this, connection,
                                     placeholders::error));
}

Server::Server(io_service &io_service)
    : acceptor_(io_service, tcp::endpoint(tcp::v4(), 1234)) {
  start_accept();
}

Server::~Server() {}

void Server::handle_accept(con_handler::pointer connection,
                           const boost::system::error_code &err) {
  if (!err) {
    connection->start();
  }
  start_accept();
}