nattypes.h

本人收集整理的一份c/c++跨平台网络库

#ifndef UTILS_BASE_NATTYPE_H_
#define UTILS_BASE_NATTYPE_H_

namespace utils_base {

/* Identifies each type of NAT that can be simulated. */
enum NATType {
  NAT_OPEN_CONE,
  NAT_ADDR_RESTRICTED,
  NAT_PORT_RESTRICTED,
  NAT_SYMMETRIC
};

// Implements the rules for each specific type of NAT.
class NAT {
public:
  // Determines whether this NAT uses both source and destination address when
  // checking whether a mapping already exists.
  virtual bool IsSymmetric() = 0;

  // Determines whether this NAT drops packets received from a different IP
  // the one last sent to.
  virtual bool FiltersIP() = 0;

  // Determines whether this NAT drops packets received from a different port
  // the one last sent to.
  virtual bool FiltersPort() = 0;

  // Returns an implementation of the given type of NAT.
  static NAT* Create(NATType type);
};

} // namespace utils_base

#endif // UTILS_BASE_NATTYPE_H_