// Functionality:
// Send a packet to the given address.
// Parameters:
// 0) [in] addr: pointer to the destination address.
// 1) [in] packet: reference to a CPacket entity.
// Returned value:
// Actual size of data sent.
public int sendto(IPEndPoint addr, CPacket packet)
{
// convert control information into network order
if (packet.getFlag() > 0)
for (int i = 0, n = packet.getLength() / 4; i < n; ++ i)
*((uint *)packet.m_pcData + i) = htonl(*((uint *)packet.m_pcData + i));
// convert packet header into network order
//for (int j = 0; j < 4; ++ j)
// packet.m_nHeader[j] = htonl(packet.m_nHeader[j]);
uint* p = packet.m_nHeader;
for (int j = 0; j < 4; ++ j)
{
*p = htonl(*p);
++ p;
}
DWORD size = CPacket.m_iPktHdrSize + packet.getLength();
//int addrsize = (AF_INET == m_iIPversion) ? sizeof(sockaddr_in) : sizeof(sockaddr_in6);
//int res = WSASendTo(m_iSocket, (LPWSABUF)packet.m_PacketVector, 2, &size, 0, addr, addrsize, null, null);
//int res = m_iSocket.SendTo(Buffer, addr);
int res = m_iSocket.SendTo(Buffer, 0, size, SocketFlags.None, addr);
res = (0 == res) ? size : -1;
// convert back into local host order
//for (int k = 0; k < 4; ++ k)
// packet.m_nHeader[k] = ntohl(packet.m_nHeader[k]);
p = packet.m_nHeader;
for (int k = 0; k < 4; ++ k)
{
*p = ntohl(*p);
++ p;
}
if (packet.getFlag() > 0)
for (int l = 0, n = packet.getLength() / 4; l < n; ++ l)
packet.m_pcData[l] = ntohl(packet.m_pcData[l]);
return res;
}
// Functionality:
// Receive a packet from the channel and record the source address.
// Parameters:
// 0) [in] addr: pointer to the source address.
// 1) [in] packet: reference to a CPacket entity.
// Returned value:
// Actual size of data received.
public int recvfrom(IPAddress addr, CPacket packet)
{
DWORD size = CPacket.m_iPktHdrSize + packet.getLength();
DWORD flag = 0;
int addrsize = (AF_INET == m_iIPversion) ? sizeof(sockaddr_in) : sizeof(sockaddr_in6);
int res = WSARecvFrom(m_iSocket, (LPWSABUF)packet.m_PacketVector, 2, &size, &flag, addr, &addrsize, null, null);
res = (0 == res) ? size : -1;
if (res <= 0)
{
packet.setLength(-1);
return -1;
}
packet.setLength(res - CPacket.m_iPktHdrSize);
// convert back into local host order
//for (int i = 0; i < 4; ++ i)
// packet.m_nHeader[i] = ntohl(packet.m_nHeader[i]);
uint* p = packet.m_nHeader;
for (int i = 0; i < 4; ++ i)
{
*p = ntohl(*p);
++ p;
}
if (packet.getFlag())
for (int j = 0, n = packet.getLength() / 4; j < n; ++ j)
*((uint *)packet.m_pcData + j) = ntohl(*((uint *)packet.m_pcData + j));
return packet.getLength();
}
public static int listen(IPAddress addr, out CPacket packet)
{
CGuard cg = new CGuard(m_ConnectionLock);
if (m_bClosing)
return 1002;
CHandShake hs = (CHandShake )packet.m_pcData;
// SYN cookie
byte[] clienthost = new byte[NI_MAXHOST];
byte[] clientport = new byte[NI_MAXSERV];
getnameinfo(addr, (AF_INET == m_iVersion) ? sizeof(sockaddr_in) : sizeof(sockaddr_in6), clienthost, sizeof(clienthost), clientport, sizeof(clientport), NI_NUMERICHOST|NI_NUMERICSERV);
Int64 timestamp = (CClock.getTime() - m_StartTime) / 60000000; // secret changes every one minute
//byte[] cookiestr = new byte[1024];
//sprintf(cookiestr, "%s:%s:%lld", clienthost, clientport, (long long int)timestamp);
string cookiestr = string.Format("{0}:{1}:{2}", clienthost, clientport, timestamp);
byte[] cookie = new byte[16];
CMD5.compute(cookiestr, cookie);
if (1 == hs.m_iReqType)
{
hs.m_iCookie = *(int*)cookie;
packet.m_iID = hs.m_iID;
m_pSndQueue.sendto(addr, packet);
return 0;
}
else
{
if (hs.m_iCookie != *(int*)cookie)
{
timestamp --;
cookiestr = string.Format("{0}:{1}:{2}", clienthost, clientport, timestamp);
CMD5.compute(cookiestr, out cookie);
if (hs.m_iCookie != *(int*)cookie)
return -1;
}
}
Int32 id = hs.m_iID;
// When a peer side connects in...
if ((1 == packet.getFlag()) && (0 == packet.getType()))
{
if ((hs.m_iVersion != m_iVersion) || (hs.m_iType != m_iSockType) || (-1 == s_UDTUnited.newConnection(m_SocketID, addr, hs)))
{
// couldn't create a new connection, reject the request
hs.m_iReqType = 1002;
}
packet.m_iID = id;
m_pSndQueue.sendto(addr, packet);
}
return hs.m_iReqType;
}
