controlportservice.cc

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/*
 * Copyright (c) 2015,2017 - Adjacent Link LLC, Bridgewater, New Jersey
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in
 *   the documentation and/or other materials provided with the
 *   distribution.
 * * Neither the name of Adjacent Link LLC nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "controlportservice.h"
#include "controlportsession.h"
#include "socketexception.h"

#include <cstring>
#include <map>
#include <algorithm>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/eventfd.h>


EMANE::ControlPort::Service::Service():
  iSignalEvent_{},
  iSock_{},
  thread_{}{}

void EMANE::ControlPort::Service::open(const INETAddr & endpoint)
{
  iSignalEvent_ = eventfd(0,0);

  if((iSock_ = socket(endpoint.getFamily(),
                      SOCK_STREAM,
                      0)) == -1)
    {
      throw SocketException(strerror(errno));
    }

  int iOption{1};

  if(setsockopt(iSock_,
                SOL_SOCKET,
                SO_REUSEADDR,
                reinterpret_cast<void*>(&iOption),
                sizeof(iOption)) < 0)
    {
      throw makeException<SocketException>("setsockopt SO_REUSEADDR: %s",
                                           strerror(errno));

    }

  if(bind(iSock_,endpoint.getSockAddr(),endpoint.getAddrLength()) < 0)
    {
      throw makeException<SocketException>("bind: %s",
                                           strerror(errno));
    }


  if(listen(iSock_,10) < 0)
    {
      throw makeException<SocketException>("listen: %s",
                                           strerror(errno));
    }

  thread_ = std::thread(&Service::process,this);
}

EMANE::ControlPort::Service::~Service()
{
  if(thread_.joinable())
    {
      close();
    }
}

void EMANE::ControlPort::Service::close()
{
  eventfd_write(iSignalEvent_,1);
  thread_.join();
  ::close(iSock_);
  ::close(iSignalEvent_);
}

void EMANE::ControlPort::Service::process()
{
  std::map<int,std::unique_ptr<Session>> sessionMap;

  while(1)
    {
      int nfds{iSignalEvent_};

      fd_set rfds;

      FD_ZERO(&rfds);
      FD_SET(iSignalEvent_,&rfds);
      FD_SET(iSock_,&rfds);

      nfds = std::max(iSock_,nfds);

      for(const auto & entry : sessionMap)
        {
          FD_SET(entry.first,&rfds);
          nfds = std::max(entry.first,nfds);
        }

      auto result = select(nfds+1,&rfds,nullptr,nullptr,nullptr);

      if(result == -1)
        {
          if(errno == EINTR)
            {
              continue;
            }
          else
            {
              break;
            }
        }

      if(FD_ISSET(iSignalEvent_,&rfds))
        {
          break;
        }

      if(FD_ISSET(iSock_,&rfds))
        {
          int iNewFd{};

          if((iNewFd = accept(iSock_,nullptr,nullptr)) > 0)
            {
              sessionMap.insert(std::make_pair(iNewFd,std::unique_ptr<Session>{new Session{}}));
            }
        }

      auto iter = sessionMap.begin();

      while(iter !=  sessionMap.end())
        {
          if(FD_ISSET(iter->first,&rfds))
            {
              // process the session data
              if(iter->second->process(iter->first))
                {
                  ::close(iter->first);
                  sessionMap.erase(iter++);
                }
              else
                {
                  ++iter;
                }
            }
          else
            {
              ++iter;
            }
        }
    }

  for(const auto & entry : sessionMap)
    {
      ::close(entry.first);
    }
}