rtorrent/rak/address_info.h

// Wrapper for addrinfo with focus on zero-copy conversion to and from
// the c-type and wrapper.
//
// Do use the wrapper on a pre-existing struct addrinfo, cast the
// pointer rather than the base type.

#ifndef RAK_ADDRESS_INFO_H
#define RAK_ADDRESS_INFO_H

#include <netdb.h>
#include <cstring>

namespace rak {

class address_info {
public:
  void                clear()                       { std::memset(this, 0, sizeof(address_info)); }

  int                 flags() const                 { return m_addrinfo.ai_flags; }
  void                set_flags(int f)              { m_addrinfo.ai_flags = f; }

  int                 family() const                { return m_addrinfo.ai_family; }
  void                set_family(int f)             { m_addrinfo.ai_family = f; }

  int                 socket_type() const           { return m_addrinfo.ai_socktype; }
  void                set_socket_type(int t)        { m_addrinfo.ai_socktype = t; }

  int                 protocol() const              { return m_addrinfo.ai_protocol; }
  void                set_protocol(int p)           { m_addrinfo.ai_protocol = p; }

  size_t              length() const                { return m_addrinfo.ai_addrlen; }

  addrinfo*           c_addrinfo()                  { return &m_addrinfo; }
  const addrinfo*     c_addrinfo() const            { return &m_addrinfo; }

  address_info*       next()                        { return reinterpret_cast<address_info*>(m_addrinfo.ai_next); }

  static int          get_address_info(const char* node, int domain, int type, address_info** ai);

  static void         free_address_info(address_info* ai) { ::freeaddrinfo(ai->c_addrinfo()); }

  static const char*  strerror(int err)                   { return gai_strerror(err); }

private:
  addrinfo            m_addrinfo;
};

inline int
address_info::get_address_info(const char* node, int pfamily, int stype, address_info** ai) {
  address_info hints;
  hints.clear();
  hints.set_family(pfamily);
  hints.set_socket_type(stype);

  return ::getaddrinfo(node, NULL, hints.c_addrinfo(), reinterpret_cast<addrinfo**>(ai));
}

}

#endif