hi...my friend and i are writing a game that we would like to use udp networking with...but we're having some trouble getting started with just sending simple text messages back and forth. our send function is printing out 'sent' but our receiver isn't getting anything. here is the header file for our class and the code: struct myaddrT { int port; char* ip; }; class CUDPConnection { public: CUDPConnection(); CUDPConnection(int port); ~CUDPConnection(); bool m_send(char* dat); bool m_recieve(char* dat); bool m_sendaddr(char* dat, myaddrT addr); bool m_sendaddr(char* dat, char* ip, int port); void m_setaddr(char* ip, int port); void m_setaddr(myaddrT addr); void m_setmsglen(int len); bool m_checkrecieve(); void m_closeconnection(); private: sockaddr_in m_myaddr; sockaddr_in m_remoteaddr; sockaddr_in m_recaddr; SOCKET m_recsocket; SOCKET m_sensocket; timeval m_to; int m_msglen; }; CUDPConnection::CUDPConnection() { CUDPConnection(5555); } CUDPConnection::CUDPConnection(int port) { m_to.tv_sec = 0; m_to.tv_usec = 0; memset((char*)&m_myaddr, 0,sizeof(m_myaddr)); m_myaddr.sin_family = AF_INET; m_myaddr.sin_addr.s_addr = htonl(INADDR_ANY); m_myaddr.sin_port = htons(port); m_recsocket = socket(AF_INET, SOCK_DGRAM, 0); m_sensocket = socket(AF_INET, SOCK_DGRAM, 0); bind( m_recsocket, (sockaddr*)&m_myaddr, sizeof(m_myaddr)); m_msglen = 0; } CUDPConnection::~CUDPConnection() { m_closeconnection(); } bool CUDPConnection::m_recieve(char* dat) { memset((char*)&m_recaddr,0,sizeof(m_recaddr)); int sockaddrlen = sizeof(SOCKADDR_IN); int status = recvfrom(m_recsocket, dat, m_msglen, 0, (sockaddr*)&m_recaddr, &sockaddrlen); if(status == SOCKET_ERROR) return false; return true; } bool CUDPConnection::m_send(char* dat) { int status = sendto(m_sensocket, dat, m_msglen, 0, (sockaddr*)&m_remoteaddr, sizeof(m_remoteaddr)); if(status == SOCKET_ERROR) return false; return true; } bool CUDPConnection::m_sendaddr(char* dat, myaddrT addr) { m_setaddr(addr); return m_send(dat); } bool CUDPConnection::m_sendaddr(char* dat, char* ip, int port) { m_setaddr(ip, port); return m_send(dat); } void CUDPConnection::m_setaddr(char* ip, int port) { memset((char*)&m_remoteaddr,0,sizeof(m_remoteaddr)); m_remoteaddr.sin_addr.s_addr = inet_addr(ip); m_remoteaddr.sin_family = AF_INET; m_remoteaddr.sin_port = port; } void CUDPConnection::m_setaddr(myaddrT addr) { memset((char*)&m_remoteaddr,0,sizeof(m_remoteaddr)); m_remoteaddr.sin_addr.s_addr = inet_addr(addr.ip); m_remoteaddr.sin_family = AF_INET; m_remoteaddr.sin_port = addr.port; } void CUDPConnection::m_setmsglen(int len) { m_msglen = len; } void CUDPConnection::m_closeconnection() { closesocket(m_recsocket); closesocket(m_sensocket); } void send_msg(CUDPConnection* sender) { sender->m_setmsglen(32); if(sender->m_sendaddr("b","10.13.30.203",5555)) //hardcoded in for now cout << "sent\n"; } void receive_msg(CUDPConnection* receiver) { receiver->m_setmsglen(32); char data[32]; if(receiver->m_recieve(data)) { cout << "I'm receiving!!!!! " << data << endl; } } thanks [edited by - MrShmoo on May 5, 2003 5:28:14 PM]

Hi, we fixed our original problem! But we have some questions about the code you posted, x33.

unsigned int addr_size = sizeof (struct sockaddr_in);
// WARNING!!! Buffer overflow!!!!!!
if ((recvfrom (sd, message, message_length, 0, (struct sockaddr*)addr, &addr_size)) < 0)

We were wondering what you mean in your comments "Buffer overflow!!!!!!".

Also we noticed that you are using a void* in your recvfrom function, but not your send function. Why can you do that?

Thanks a bunch!

[edited by - mrshmoo on May 6, 2003 7:51:25 PM]

Pointers are just integers once the front end is done parsing them.

Thanks you guys. This helps a lot.