Re: How can I extract the destination IP address from incoming req

Dear Arkady,
I am afraid that you couldn't understand my post. However, the clientAddress
contains all the information of the source peer (the client), while I am
looking for the information of the destination peer.

My code is on a multihomed server, and I want to know the destination
address that sent by the client in order to know on which interface or
destiantion IP the request has been made by the client. In otherword, by
which interface the request has been received.

regards
Bassam

"Arkady Frenkel" wrote:

From clientAddress. It's of type
struct sockaddr_in {
short sin_family;
u_short sin_port;
struct in_addr sin_addr;
char sin_zero[8];
} where sin_addr struct include IPArkady
Arkady
"Bassam" <Bassam@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:B5EB246F-A4DA-406E-AF7D-EE80133A8F26@xxxxxxxxxxxxxxxx
Dear All,
I am writing a Radius server using winsock2 with win32 C++ on visual C++
2005 express edition on windows xp pro.

My application is listening for all the UDP packets on all the interfaces
on
a multihomed machin. However, I am trying to add a feature to my server
where
I can reject requests incoming from or sent to a specific interface(s).

My question is that how to extract the destination IP address of all the
request targeted to my server so that I can decide whether to further
process
the request or just ignore it.

A snippet pf my code:
------------------------------------------------
ADDRINFO addressHints;
LPADDRINFO radiusResult = NULL, pointerResult = NULL;

//some code here

SecureZeroMemory(&addressHints, sizeof(addressHints));

addressHints.ai_flags = AI_PASSIVE;
addressHints.ai_family = AF_UNSPEC;
addressHints.ai_socktype = SOCK_DGRAM;
addressHints.ai_protocol = IPPROTO_UDP;

//Listen to all the interfaces
if(getaddrinfo(NULL, "1812", &addressHints, &radiusResult) != 0)
{
cerr << "\n\n\nError no." << WSAGetLastError() << ": check getaddrinfo()"
<< endl;
exit(EXIT_FAILURE);
}


//create IPv4 and IPv6 sockets for radius (authentication and
authorization)
//and then bind it to the socket address structures
count = 0;
pointerResult = radiusResult;

while(pointerResult)
{

//create the authentication and authorization sockets for both IPv4 and
IPv6
if((radiusSocket[count] = WSASocket(pointerResult->ai_family,
pointerResult->ai_socktype, pointerResult->ai_protocol, NULL, 0, NULL)) ==
INVALID_SOCKET)
{
cerr << "\n\n\nError no." << WSAGetLastError() << ": check WSASocket()" <<
endl;
exit(EXIT_FAILURE);
}

if(bind(radiusSocket[count], pointerResult->ai_addr,
pointerResult->ai_addrlen)== SOCKET_ERROR)
{
cerr << "\n\n\nError no." << WSAGetLastError() << ": check bind()" <<
endl;
exit(EXIT_FAILURE);
}

count++;
//get the next entry of the winsock cataloge
pointerResult = pointerResult->ai_next;
}

while(true)
{
FD_ZERO(&fdReadSockets);

//Add all the socket handlers to all fd_set
for (count = 0; count < MAX_SOCKETS_ARRAY_SIZE; count++)
{
FD_SET(radiusSocket[count], &fdReadSockets);
FD_SET(accountSocket[count], &fdReadSockets);
}

if ((functionReturnValue = select(0, &fdReadSockets, NULL, NULL,
&selectTimeOut)) == SOCKET_ERROR)
{
cerr << "\n\n\nError no." << WSAGetLastError() << ": check select()" <<
endl;
exit(EXIT_FAILURE);
}

if (functionReturnValue > 0)
{
for (count = 0; count < MAX_SOCKETS_ARRAY_SIZE; count++)
{
//check the data received for authentication and authorization
if (FD_ISSET(radiusSocket[count], &fdReadSockets))
{
//some code here
flags = 0;
clientAddressSize = sizeof(clientAddress);
if ((WSARecvFrom(radiusSocket[count], radiusPacketData,
RADIUS_PACKET_FIELDS, &bytesReceived, &flags,
reinterpret_cast<PSOCKADDR>(&clientAddress), &clientAddressSize, NULL,
NULL)
== SOCKET_ERROR) && (WSAGetLastError() != WSAECONNRESET))
{
cerr << "\n\n\nError no." << WSAGetLastError() << ": check WSARecvFrom()"
<< endl;
exit(EXIT_FAILURE);
}



if (WSASendTo(radiusSocket[count], radiusPacketData, RADIUS_PACKET_FIELDS,
&bytesSent, flags, reinterpret_cast<PSOCKADDR>(&clientAddress),
clientAddressSize, NULL, NULL) == SOCKET_ERROR)
{
cerr << "\n\n\nError no." << WSAGetLastError() << ": check WSASendTo()"
<< endl;
exit(EXIT_FAILURE);
}
}

}

//house keeping stuff

------------------------------------------


Your help is much appreciated

Regards
Bassam



.

Relevant Pages
Loading