path: root/ace/SOCK_Dgram_Mcast.cpp

// $Id$

#define ACE_BUILD_DLL
#include "ace/SOCK_Dgram_Mcast.h"
#include "ace/INET_Addr.h"

#if defined (ACE_LACKS_INLINE_FUNCTIONS)
#include "ace/SOCK_Dgram_Mcast.i"
#endif

ACE_RCSID(ace, SOCK_Dgram_Mcast, "$Id$")

ACE_ALLOC_HOOK_DEFINE(ACE_SOCK_Dgram_Mcast)

void
ACE_SOCK_Dgram_Mcast::dump (void) const
{
  ACE_TRACE ("ACE_SOCK_Dgram_Mcast::dump");
}

// Dummy default constructor...

ACE_SOCK_Dgram_Mcast::ACE_SOCK_Dgram_Mcast (void)
{
  ACE_TRACE ("ACE_SOCK_Dgram_Mcast::ACE_SOCK_Dgram_Mcast");
}

int
ACE_SOCK_Dgram_Mcast::subscribe (const ACE_INET_Addr &mcast_addr,
                                 int reuse_addr,
#if defined (ACE_PSOS)
                                 // pSOS supports numbers, not
                                 // names for network interfaces
                                 long net_if,
#else
                                 const ASYS_TCHAR *net_if,
#endif /* defined (ACE_PSOS) */
                                 int protocol_family,
                                 int protocol)
{
  ACE_TRACE ("ACE_SOCK_Dgram_Mcast::subscribe");

  // Make a local copy of address to use in sends.
  this->mcast_addr_.set (mcast_addr);

  // Only perform the open() initialization if we haven't been opened
  // previously.
  if (this->get_handle () == ACE_INVALID_HANDLE)
    {
      if (ACE_SOCK::open (SOCK_DGRAM, protocol_family,
                      protocol, reuse_addr) == -1)
        return -1;

      int one = 1;
      if (reuse_addr
          && this->ACE_SOCK::set_option (SOL_SOCKET,
                                         SO_REUSEADDR,
                                         &one,
                                         sizeof one) == -1)
        return -1;
#if defined (SO_REUSEPORT)
      if (this->ACE_SOCK::set_option (SOL_SOCKET,
                                      SO_REUSEPORT,
                                      &one,
                                      sizeof one) == -1)
        return -1;
#endif /* SO_REUSEPORT */

      // Create an address to bind the socket to.

      ACE_INET_Addr local;

      if (local.set (this->mcast_addr_.get_port_number ()) == -1)
        return -1;
      else if (ACE_SOCK_Dgram::shared_open (local, protocol_family) == -1)
        return -1;
    }
#if defined (ACE_WIN32)
  // Windows NT's winsock has trouble with multicast subscribes in the presence
  // of multiple network interfaces when the IP address is given as INADDR_ANY.
  // It will pick the first interface and only accept mcast there.  So, to work
  // around this, cycle through all of the interfaces known and subscribe to
  // all the non-loopback ones.
  // Note that this only needs to be done on NT, but there's no way to tell
  // at this point if the code will be running on NT - only if it is compiled
  // for NT-only or for NT/95, and that doesn't really help us.  It doesn't
  // hurt to do this on Win95, it's just a little slower than it normally
  // would be.
  //
  // NOTE - get_ip_interfaces doesn't always get all of the interfaces.  In
  // particular, it may not get a PPP interface.  This is a limitation of the
  // way get_ip_interfaces works with MSVC.  The reliable way of getting the
  // interface list is available only with MSVC 5.

  if (net_if == 0)
    {
      ACE_INET_Addr *if_addrs = 0;
      size_t         if_cnt, nr_subscribed;

      if (ACE::get_ip_interfaces(if_cnt, if_addrs) != 0)
        return -1;

      nr_subscribed = 0;

      if (if_cnt < 2)
        {
          if (this->subscribe(mcast_addr,
                              reuse_addr,
                              ASYS_WIDE_STRING ("0.0.0.0"),
                              protocol_family,
                              protocol) == 0)
            ++nr_subscribed;
        }
      else
        while (if_cnt > 0)
          {
            --if_cnt;    // Convert to 0-based for indexing, next loop check
            if (if_addrs[if_cnt].get_ip_address() == INADDR_LOOPBACK)
              continue;
            if (this->subscribe(mcast_addr,
                                reuse_addr,
                                ASYS_WIDE_STRING (if_addrs[if_cnt].get_host_addr()),
                                protocol_family,
                                protocol) == 0)
              ++nr_subscribed;
          }

      delete [] if_addrs;

      if (nr_subscribed == 0)
        {
          errno = ENODEV;
          return -1;
        }
      return 0;
    }
  // else do it like everyone else...
#endif /* ACE_WIN32 */

  // Create multicast request.
  if (this->make_multicast_address (this->mcast_addr_, net_if) == -1)
    return -1;

  // Tell network device driver to read datagrams with a
  // multicast_address address.
  else if (this->ACE_SOCK::set_option (IPPROTO_IP,
                                       IP_ADD_MEMBERSHIP,
                                       &multicast_address_,
                                       sizeof multicast_address_) == -1)
    return -1;
  return 0;
}

int
ACE_SOCK_Dgram_Mcast::unsubscribe (const ACE_INET_Addr &mcast_addr,
#if defined (ACE_PSOS)
                                   // pSOS supports numbers, not
                                   // names for network interfaces
                                   long net_if,
#else
                                   const ASYS_TCHAR *net_if,
#endif /* defined (ACE_PSOS) */
                                   int protocol_family,
                                   int protocol)
{
  ACE_TRACE ("ACE_SOCK_Dgram_Mcast::subscribe");

#if defined (ACE_WIN32)
  // Windows NT's winsock has trouble with multicast subscribes in the presence
  // of multiple network interfaces when the IP address is given as INADDR_ANY.
  // It will pick the first interface and only accept mcast there.  So, to work
  // around this, cycle through all of the interfaces known and subscribe to
  // all the non-loopback ones.
  // Note that this only needs to be done on NT, but there's no way to tell
  // at this point if the code will be running on NT - only if it is compiled
  // for NT-only or for NT/95, and that doesn't really help us.  It doesn't
  // hurt to do this on Win95, it's just a little slower than it normally
  // would be.
  //
  // NOTE - get_ip_interfaces doesn't always get all of the interfaces.  In
  // particular, it may not get a PPP interface.  This is a limitation of the
  // way get_ip_interfaces works with MSVC.  The reliable way of getting the
  // interface list is available only with MSVC 5.

  if (net_if == 0)
    {
      ACE_INET_Addr *if_addrs = 0;
      size_t         if_cnt;

      if (ACE::get_ip_interfaces(if_cnt, if_addrs) != 0)
        return -1;

      size_t nr_unsubscribed = 0;

      if (if_cnt < 2)
        {
          if (this->unsubscribe (mcast_addr,
                                 ASYS_WIDE_STRING ("0.0.0.0"),
                                 protocol_family,
                                 protocol) == 0)
            ++nr_unsubscribed;
        }
      else
        while (if_cnt > 0)
          {
            --if_cnt;    // Convert to 0-based for indexing, next loop check
            if (if_addrs[if_cnt].get_ip_address() == INADDR_LOOPBACK)
              continue;
            if (this->unsubscribe (mcast_addr,
                                   ASYS_WIDE_STRING (if_addrs[if_cnt].get_host_addr()),
                                   protocol_family,
                                   protocol) == 0)
              ++nr_unsubscribed;
          }

      delete [] if_addrs;

      if (nr_unsubscribed == 0)
        {
          errno = ENODEV;
          return -1;
        }
      return 0;
    }
  // else do it like everyone else...
#endif /* ACE_WIN32 */

  ACE_UNUSED_ARG (protocol_family);
  ACE_UNUSED_ARG (protocol);

  ip_mreq multicast_address;
  // Create multicast request.
  if (this->make_multicast_address_i (mcast_addr, multicast_address, net_if) == -1)
    return -1;

  // Tell network device driver to read datagrams with a
  // multicast_address address.
  else if (this->ACE_SOCK::set_option (IPPROTO_IP,
                                       IP_DROP_MEMBERSHIP,
                                       &multicast_address,
                                       sizeof multicast_address) == -1)
    return -1;
  return 0;
}

int
ACE_SOCK_Dgram_Mcast::unsubscribe (void)
{
  ACE_TRACE ("ACE_SOCK_Dgram_Mcast::unsubscribe");
  return this->ACE_SOCK::set_option (IPPROTO_IP,
                                     IP_DROP_MEMBERSHIP,
                                     &multicast_address_,
                                     sizeof multicast_address_);
}

int
ACE_SOCK_Dgram_Mcast::make_multicast_address (const ACE_INET_Addr &mcast_addr,
#if defined (ACE_PSOS)
                                              // pSOS supports numbers, not
                                              // names for network interfaces
                                              long net_if
#else
                                              const ASYS_TCHAR *net_if
#endif /* defined (ACE_PSOS) */
                                             )
{
  ACE_TRACE ("ACE_SOCK_Dgram_Mcast::make_multicast_address");

  return this->make_multicast_address_i (mcast_addr,
                                         this->multicast_address_,
                                         net_if );
}

int
ACE_SOCK_Dgram_Mcast::make_multicast_address_i (const ACE_INET_Addr &mcast_addr,
                                                ip_mreq &multicast_address ,
#if defined (ACE_PSOS)
                                                // pSOS supports numbers, not
                                                // names for network interfaces
                                                long net_if
#else
                                                const ASYS_TCHAR *net_if
#endif /* defined (ACE_PSOS) */
                                                )
{
  if (net_if != 0)
    {
#if !defined (ACE_WIN32)
      struct ifreq if_address;

#if defined (ACE_PSOS)
      // look up the interface by number, not name
      if_address.ifr_ifno = net_if;
#else
      ACE_OS::strcpy (if_address.ifr_name, net_if);
#endif /* defined (ACE_PSOS) */

      if (ACE_OS::ioctl (this->get_handle (), SIOCGIFADDR, &if_address) == -1)
        return -1;

      struct sockaddr_in *socket_address;
      socket_address = ACE_reinterpret_cast(sockaddr_in *,
                                            &if_address.ifr_addr);
      multicast_address.imr_interface.s_addr = socket_address->sin_addr.s_addr;
#else
      // This port number is not necessary, just convenient
      ACE_INET_Addr interface_addr;
      if (interface_addr.set (mcast_addr.get_port_number (),
                              net_if) == -1)
        return -1;
      multicast_address.imr_interface.s_addr =
        htonl (interface_addr.get_ip_address ());
#endif /* ACE_WIN32 */
    }
  else
    multicast_address.imr_interface.s_addr = INADDR_ANY;

#if defined (ACE_PSOS) && !defined (ACE_PSOS_TM)
  multicast_address.imr_mcastaddr.s_addr = htonl (mcast_addr.get_ip_address ());
#else
  multicast_address.imr_multiaddr.s_addr = htonl (mcast_addr.get_ip_address ());
#endif /* defined (ACE_PSOS) */
  return 0;
}