ethernetPacketBackendLinux.cpp

Go to the documentation of this file.

 
 
#include <unistd.h>
 
#include <asio/posix/stream_descriptor.hpp>
#include <cerrno>
#include <cstring>
 
#include "profinet/ethernetPacketBackend.h"
#include "profinet/exceptions.h"
 
namespace profinet
{
void AsioEthernetSocket::EthernetPacketBackend::InitializePacketWait()
{
  const int selectableFd =
      pcap_get_selectable_fd(capture);
 
  if (selectableFd < 0)
  {
    usePolling = true;
    return;
  }
 
  const int duplicatedFd = ::dup(selectableFd);
 
  if (duplicatedFd < 0)
  {
    throw SocketError("Failed to duplicate libpcap selectable descriptor: " + std::string(std::strerror(errno)));
  }
 
  asio::error_code error;
 
  packetWait.assign(duplicatedFd, error);
 
  if (error)
  {
    ::close(duplicatedFd);
 
    throw SocketError("Failed to assign libpcap descriptor to Asio: " + error.message());
  }
 
  usePolling = false;
}
 
void AsioEthernetSocket::EthernetPacketBackend::AsyncWaitForPacket(const std::shared_ptr<ReceiveOperation>& operation)
{
  if (usePolling)
  {
    operation->pollTimer.expires_after(std::chrono::milliseconds(1));
 
    operation->pollTimer.async_wait([this, operation](const asio::error_code& error)
    {
      HandlePacketReady(operation, error);
    });
 
    return;
  }
 
  packetWait.async_wait(asio::posix::stream_descriptor::wait_read, [this, operation](const asio::error_code& error)
  {
    HandlePacketReady(operation, error);
  });
}
 
void AsioEthernetSocket::EthernetPacketBackend::CancelPacketWait(const std::shared_ptr<ReceiveOperation>& operation, asio::error_code& error)
{
  if (usePolling)
  {
    operation->pollTimer.cancel(error);
  }
  else
  {
    packetWait.cancel(error);
  }
}
 
} // namespace profinet