Problem sending/receiving radius accounting UDP packet using winsock
Posted on 2010-08-24
I'm trying to send a radius auth start/stop message using winsock in a C++ program.
I have all the values inc. shared secret, and I believe I am forming a valid radius packet inc. MD5 hash but I can't be 100% sure.
I don't control the radius server I'm trying to hit...
NTRadPing 1.5 works fine, but on the same machine, my app doesn't (i.e. the packet never gets there or is ignored). My packet length is the same length as the one that ntradping is sending, with what I believe are all the same parameters.
Assuming my radius packet is correctly set up, how do I make my winsock code work properly to read a response?
The "recv()" call hangs - perhaps because the radius server is ignoring or not receiving the message.
I'm having trouble reading the response. Here is what I'm trying to do with winsock (leaving out error handling and such):
SOCKET sendSocket = NULL;
DWORD dwPort = 1813;
char * szHostIP = "220.127.116.11"; // real IP hidden
WSAStartup(MAKEWORD(1, 1), &wsadata);
sendSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
recvAddr.sin_family = AF_INET;
recvAddr.sin_port = htons((u_short)dwPort);
recvAddr.sin_addr.s_addr = inet_addr(szHostIP);
connect(sendSocket, (SOCKADDR *)&recvAddr, sizeof(recvAddr));
send(sendSocket, (const char *)rgbBuf, cbLen, 0);
recv(sendSocket, achBufRecv, min(20, sizeof(achBufRecv)), 0);