Re: SLP in MFC

From:

"AliR $VC++ MVP$" <AliR@online.nospam>

Newsgroups:

microsoft.public.vc.mfc

Date:

Mon, 15 Oct 2007 13:51:37 -0500

Message-ID:

<YIOQi.4714$sm6.1747@nlpi069.nbdc.sbc.com>

(I don't anything about the SLP protocal.) But as far as the multicast
socket goes, you will also have to use SetSocketOpt to join the multicast
group.

Something like this
BOOL LSSocket::CreateReceivingMulticastSocket(LPCTSTR strGroupIP, UINT
nGroupPort,DWORD &Error)
{
   /* Create socket for receiving packets from multicast group */
   if(!CAsyncSocket::Create(nGroupPort, SOCK_DGRAM,FD_READ))
   {
      Error = GetLastError();
      return FALSE;
   }

   m_UDP = TRUE;

   BOOL bMultipleApps = TRUE; /* allow reuse of local port if needed */
   SetSockOpt(SO_REUSEADDR, (void*)&bMultipleApps, sizeof(BOOL),
SOL_SOCKET);

   /* Join the multicast group */
   m_mrMReq.imr_multiaddr.s_addr = inet_addr(strGroupIP); /* group addr */
   m_mrMReq.imr_interface.s_addr = htons(INADDR_ANY); /* use default */
   setsockopt(m_hSocket, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char FAR
*)&m_mrMReq, sizeof(m_mrMReq));
   return TRUE;
}

AliR.

"Joseph M. Newcomer" <newcomer@flounder.com> wrote in message
news:8u87h3paloji1p3uhcj296gia0ai4d4s7f@4ax.com...

Thanks for the pointer. According to the page
http://www.openslp.org/doc/rfc/rfc2608.txt
section 6.1, it appears that SLP can run over UDP or TCP, and as UDP then
it would (and
servers are expected to) support UDP Multicast. So it is a layer built on
top of both UDP
and TCP/IP. The issue being that if a packet would exceed the maximum UDP
packet size,
then a TCP connection has to be established, but this is apparently
detectable because an
"overflow" bit is set for the response. So the bottom line is that using
CAsyncSocket
with a UDP connection should satisfy the requirments of multicasting, at
least as far as I
have been able to infer in a quick read of the material.
joe

On Mon, 15 Oct 2007 10:33:48 -0500, "AliR $VC++ MVP$"
<AliR@online.nospam> wrote:

http://www.openslp.org/doc/html/IntroductionToSLP/index.html

"Joseph M. Newcomer" <newcomer@flounder.com> wrote in message
news:50p6h3tujl6tdlojtdspk6mmj2nfriefih@4ax.com...

If I knew what SLP was, I might have a chance to answer the question.
Is
it some protocol
implemented using UDP? If it involves UDP, I'd use CAsyncSocket. If
not,
since I don't
recognize the acronym, I'm otherwise at a loss.
joe

On Sun, 14 Oct 2007 21:43:51 -0700, "doublemaster007@gmail.com"
<doublemaster007@gmail.com> wrote:

Hi all,

Could any one please explain me how to multicast SLP packet in MFC? Is
there any sample code for this?

Nas

Joseph M. Newcomer [MVP]
email: newcomer@flounder.com
Web: http://www.flounder.com
MVP Tips: http://www.flounder.com/mvp_tips.htm