socket_ops.hpp

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  (void)(buffer);
  (void)(buflength);
  (void)(ai_flags);
  if (af != AF_INET)
  {
    ec = asio::error::address_family_not_supported;
    return 0;
  }
  hostent* retval = error_wrapper(::gethostbyname(name), ec);
  if (!retval)
    return 0;
# if defined(UNDER_CE)
  clear_error(ec);
# endif
  *result = *retval;
  return result;
#elif defined(__sun) || defined(__QNX__)
  (void)(ai_flags);
  if (af != AF_INET)
  {
    ec = asio::error::address_family_not_supported;
    return 0;
  }
  int error = 0;
  hostent* retval = error_wrapper(::gethostbyname_r(name, result, buffer,
        buflength, &error), ec);
  if (error)
    ec = translate_netdb_error(error);
  return retval;
#elif defined(__MACH__) && defined(__APPLE__)
  (void)(buffer);
  (void)(buflength);
  int error = 0;
  hostent* retval = error_wrapper(::getipnodebyname(
        name, af, ai_flags, &error), ec);
  if (error)
    ec = translate_netdb_error(error);
  if (!retval)
    return 0;
  *result = *retval;
  return retval;
#else
  (void)(ai_flags);
  if (af != AF_INET)
  {
    ec = asio::error::address_family_not_supported;
    return 0;
  }
  hostent* retval = 0;
  int error = 0;
  error_wrapper(::gethostbyname_r(name, result,
        buffer, buflength, &retval, &error), ec);
  if (error)
    ec = translate_netdb_error(error);
  return retval;
#endif
}

inline void freehostent(hostent* h)
{
#if defined(__MACH__) && defined(__APPLE__)
  if (h)
    ::freehostent(h);
#else
  (void)(h);
#endif
}

// Emulation of getaddrinfo based on implementation in:
// Stevens, W. R., UNIX Network Programming Vol. 1, 2nd Ed., Prentice-Hall 1998.

struct gai_search
{
  const char* host;
  int family;
};

inline int gai_nsearch(const char* host,
    const addrinfo_type* hints, gai_search (&search)[2])
{
  int search_count = 0;
  if (host == 0 || host[0] == '\0')
  {
    if (hints->ai_flags & AI_PASSIVE)
    {
      // No host and AI_PASSIVE implies wildcard bind.
      switch (hints->ai_family)
      {
      case AF_INET:
        search[search_count].host = "0.0.0.0";
        search[search_count].family = AF_INET;
        ++search_count;
        break;
      case AF_INET6:
        search[search_count].host = "0::0";
        search[search_count].family = AF_INET6;
        ++search_count;
        break;
      case AF_UNSPEC:
        search[search_count].host = "0::0";
        search[search_count].family = AF_INET6;
        ++search_count;
        search[search_count].host = "0.0.0.0";
        search[search_count].family = AF_INET;
        ++search_count;
        break;
      default:
        break;
      }
    }
    else
    {
      // No host and not AI_PASSIVE means connect to local host.
      switch (hints->ai_family)
      {
      case AF_INET:
        search[search_count].host = "localhost";
        search[search_count].family = AF_INET;
        ++search_count;
        break;
      case AF_INET6:
        search[search_count].host = "localhost";
        search[search_count].family = AF_INET6;
        ++search_count;
        break;
      case AF_UNSPEC:
        search[search_count].host = "localhost";
        search[search_count].family = AF_INET6;
        ++search_count;
        search[search_count].host = "localhost";
        search[search_count].family = AF_INET;
        ++search_count;
        break;
      default:
        break;
      }
    }
  }
  else
  {
    // Host is specified.
    switch (hints->ai_family)
    {
    case AF_INET:
      search[search_count].host = host;
      search[search_count].family = AF_INET;
      ++search_count;
      break;
    case AF_INET6:
      search[search_count].host = host;
      search[search_count].family = AF_INET6;
      ++search_count;
      break;
    case AF_UNSPEC:
      search[search_count].host = host;
      search[search_count].family = AF_INET6;
      ++search_count;
      search[search_count].host = host;
      search[search_count].family = AF_INET;
      ++search_count;
      break;
    default:
      break;
    }
  }
  return search_count;
}

template <typename T>
inline T* gai_alloc(std::size_t size = sizeof(T))
{
  using namespace std;
  T* p = static_cast<T*>(::operator new(size, std::nothrow));
  if (p)
    memset(p, 0, size);
  return p;
}

inline void gai_free(void* p)
{
  ::operator delete(p);
}

inline void gai_strcpy(char* target, const char* source, std::size_t max_size)
{
  using namespace std;
#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400) && !defined(UNDER_CE)
  strcpy_s(target, max_size, source);
#else
  *target = 0;
  strncat(target, source, max_size);
#endif
}

enum { gai_clone_flag = 1 << 30 };

inline int gai_aistruct(addrinfo_type*** next, const addrinfo_type* hints,
    const void* addr, int family)
{
  using namespace std;

  addrinfo_type* ai = gai_alloc<addrinfo_type>();
  if (ai == 0)
    return EAI_MEMORY;

  ai->ai_next = 0;
  **next = ai;
  *next = &ai->ai_next;

  ai->ai_canonname = 0;
  ai->ai_socktype = hints->ai_socktype;
  if (ai->ai_socktype == 0)
    ai->ai_flags |= gai_clone_flag;
  ai->ai_protocol = hints->ai_protocol;
  ai->ai_family = family;

  switch (ai->ai_family)
  {
  case AF_INET:
    {
      sockaddr_in4_type* sinptr = gai_alloc<sockaddr_in4_type>();
      if (sinptr == 0)
        return EAI_MEMORY;
      sinptr->sin_family = AF_INET;
      memcpy(&sinptr->sin_addr, addr, sizeof(in4_addr_type));
      ai->ai_addr = reinterpret_cast<sockaddr*>(sinptr);
      ai->ai_addrlen = sizeof(sockaddr_in4_type);
      break;
    }
  case AF_INET6:
    {
      sockaddr_in6_type* sin6ptr = gai_alloc<sockaddr_in6_type>();
      if (sin6ptr == 0)
        return EAI_MEMORY;
      sin6ptr->sin6_family = AF_INET6;
      memcpy(&sin6ptr->sin6_addr, addr, sizeof(in6_addr_type));
      ai->ai_addr = reinterpret_cast<sockaddr*>(sin6ptr);
      ai->ai_addrlen = sizeof(sockaddr_in6_type);
      break;
    }
  default:
    break;
  }

  return 0;
}

inline addrinfo_type* gai_clone(addrinfo_type* ai)
{
  using namespace std;

  addrinfo_type* new_ai = gai_alloc<addrinfo_type>();
  if (new_ai == 0)
    return new_ai;

  new_ai->ai_next = ai->ai_next;
  ai->ai_next = new_ai;

  new_ai->ai_flags = 0;
  new_ai->ai_family = ai->ai_family;
  new_ai->ai_socktype = ai->ai_socktype;
  new_ai->ai_protocol = ai->ai_protocol;
  new_ai->ai_canonname = 0;
  new_ai->ai_addrlen = ai->ai_addrlen;
  new_ai->ai_addr = gai_alloc<sockaddr>(ai->ai_addrlen);
  memcpy(new_ai->ai_addr, ai->ai_addr, ai->ai_addrlen);

  return new_ai;
}

inline int gai_port(addrinfo_type* aihead, int port, int socktype)
{
  int num_found = 0;

  for (addrinfo_type* ai = aihead; ai; ai = ai->ai_next)
  {
    if (ai->ai_flags & gai_clone_flag)
    {
      if (ai->ai_socktype != 0)
      {
        ai = gai_clone(ai);
        if (ai == 0)
          return -1;
        // ai now points to newly cloned entry.
      }
    }
    else if (ai->ai_socktype != socktype)
    {
      // Ignore if mismatch on socket type.
      continue;
    }

    ai->ai_socktype = socktype;

    switch (ai->ai_family)
    {
    case AF_INET:
      {
        sockaddr_in4_type* sinptr =
          reinterpret_cast<sockaddr_in4_type*>(ai->ai_addr);
        sinptr->sin_port = port;
        ++num_found;
        break;
      }
    case AF_INET6:
      {
        sockaddr_in6_type* sin6ptr =
          reinterpret_cast<sockaddr_in6_type*>(ai->ai_addr);
        sin6ptr->sin6_port = port;
        ++num_found;
        break;
      }
    default:
      break;
    }
  }

  return num_found;
}

inline int gai_serv(addrinfo_type* aihead,
    const addrinfo_type* hints, const char* serv)
{
  using namespace std;

  int num_found = 0;

  if (
#if defined(AI_NUMERICSERV)
      (hints->ai_flags & AI_NUMERICSERV) ||
#endif
      isdigit(serv[0]))
  {
    int port = htons(atoi(serv));
    if (hints->ai_socktype)
    {
      // Caller specifies socket type.
      int rc = gai_port(aihead, port, hints->ai_socktype);
      if (rc < 0)
        return EAI_MEMORY;
      num_found += rc;
    }
    else
    {
      // Caller does not specify socket type.
      int rc = gai_port(aihead, port, SOCK_STREAM);
      if (rc < 0)
        return EAI_MEMORY;
      num_found += rc;
      rc = gai_port(aihead, port, SOCK_DGRAM);
      if (rc < 0)
        return EAI_MEMORY;
      num_found += rc;
    }
  }
  else
  {
    // Try service name with TCP first, then UDP.
    if (hints->ai_socktype == 0 || hints->ai_socktype == SOCK_STREAM)
    {
      servent* sptr = getservbyname(serv, "tcp");
      if (sptr != 0)
      {
        int rc = gai_port(aihead, sptr->s_port, SOCK_STREAM);
        if (rc < 0)
          return EAI_MEMORY;
        num_found += rc;
      }
    }
    if (hints->ai_socktype == 0 || hints->ai_socktype == SOCK_DGRAM)
    {
      servent* sptr = getservbyname(serv, "udp");
      if (sptr != 0)
      {
        int rc = gai_port(aihead, sptr->s_port, SOCK_DGRAM);
        if (rc < 0)
          return EAI_MEMORY;
        num_found += rc;
      }
    }
  }

  if (num_found == 0)
  {
    if (hints->ai_socktype == 0)
    {
      // All calls to getservbyname() failed.
      return EAI_NONAME;
    }
    else
    {
      // Service not supported for socket type.
      return EAI_SERVICE;
    }
  }

  return 0;
}

inline int gai_echeck(const char* host, const char* service,
    int flags, int family, int socktype, int protocol)
{
  (void)(flags);
  (void)(protocol);

  // Host or service must be specified.
  if (host == 0 || host[0] == '\0')
    if (service == 0 || service[0] == '\0')
      return EAI_NONAME;

  // Check combination of family and socket type.
  switch (family)
  {
  case AF_UNSPEC:
    break;
  case AF_INET:
  case AF_INET6:
    if (socktype != 0 && socktype != SOCK_STREAM && socktype != SOCK_DGRAM)
      return EAI_SOCKTYPE;
    break;
  default:
    return EAI_FAMILY;
  }

  return 0;
}

inline void freeaddrinfo_emulation(addrinfo_type* aihead)
{
  addrinfo_type* ai = aihead;
  while (ai)
  {
    gai_free(ai->ai_addr);
    gai_free(ai->ai_canonname);
    addrinfo_type* ainext = ai->ai_next;
    gai_free(ai);
    ai = ainext;
  }
}

inline int getaddrinfo_emulation(const char* host, const char* service,
    const addrinfo_type* hintsp, addrinfo_type** result)
{
  // Set up linked list of addrinfo structures.
  addrinfo_type* aihead = 0;
  addrinfo_type** ainext = &aihead;
  char* canon = 0;

  // Supply default hints if not specified by caller.
  addrinfo_type hints = addrinfo_type();
  hints.ai_family = AF_UNSPEC;
  if (hintsp)
    hints = *hintsp;

  // If the resolution is not specifically for AF_INET6, remove the AI_V4MAPPED
  // and AI_ALL flags.
#if defined(AI_V4MAPPED)
  if (hints.ai_family != AF_INET6)
    hints.ai_flags &= ~AI_V4MAPPED;
#endif
#if defined(AI_ALL)
  if (hints.ai_family != AF_INET6)
    hints.ai_flags &= ~AI_ALL;
#endif

  // Basic error checking.
  int rc = gai_echeck(host, service, hints.ai_flags, hints.ai_family,
      hints.ai_socktype, hints.ai_protocol);
  if (rc != 0)
  {