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#include "stdafx.h"
SYNC_COUNTER Q931SyncCounter;ASYNC_ACCEPT Q931AsyncAccept;SOCKADDR_IN Q931ListenSocketAddress;HANDLE Q931LoopbackRedirectHandle;
staticHRESULTQ931AsyncAcceptFunctionInternal ( IN PVOID Context, IN SOCKET Socket, IN SOCKADDR_IN * LocalAddress, IN SOCKADDR_IN * RemoteAddress );
voidQ931AsyncAcceptFunction ( IN PVOID Context, IN SOCKET Socket, IN SOCKADDR_IN * LocalAddress, IN SOCKADDR_IN * RemoteAddress ){ HRESULT Result;
Result = Q931AsyncAcceptFunctionInternal ( Context, Socket, LocalAddress, RemoteAddress );
if (S_OK != Result) {
if (INVALID_SOCKET != Socket) {
closesocket (Socket);
Socket = INVALID_SOCKET;
} }} staticHRESULTQ931AsyncAcceptFunctionInternal ( IN PVOID Context, IN SOCKET Socket, IN SOCKADDR_IN * LocalAddress, IN SOCKADDR_IN * RemoteAddress ){ CALL_BRIDGE * CallBridge; HRESULT Result; NAT_KEY_SESSION_MAPPING_EX_INFORMATION RedirectInformation; ULONG RedirectInformationLength; ULONG Error; DWORD BestInterfaceAddress;
DebugF (_T("Q931: ----------------------------------------------------------------------\n"));
#if DBG
ExposeTimingWindow ();#endif
// a new Q.931 connection has been accepted from the network.
// first, we determine the original addresses of the transport connection.
// if the connection was redirected to our socket (due to NAT),
// then the query of the NAT redirect table will yield the original transport addresses.
// if an errant client has connected to our service, well, we really didn't
// intend for that to happen, so we just immediately close the socket.
assert (NatHandle);
RedirectInformationLength = sizeof (RedirectInformation);
Result = NatLookupAndQueryInformationSessionMapping ( NatHandle, IPPROTO_TCP, LocalAddress -> sin_addr.s_addr, LocalAddress -> sin_port, RemoteAddress -> sin_addr.s_addr, RemoteAddress -> sin_port, &RedirectInformation, &RedirectInformationLength, NatKeySessionMappingExInformation);
if (STATUS_SUCCESS != STATUS_SUCCESS) {
DebugError (Result, _T("Q931: New connection was accepted, but it is not in the NAT redirect table -- connection will be rejected.\n"));
return Result; }
Error = GetBestInterfaceAddress (ntohl (RedirectInformation.DestinationAddress), &BestInterfaceAddress);
if (ERROR_SUCCESS != Error) {
if (WSAEHOSTUNREACH == Error) { Error = RasAutoDialSharedConnection (); if (ERROR_SUCCESS != Error) { DebugF (_T("Q931: RasAutoDialSharedConnection failed. Error=%d\n"), Error); } } else { DebugError (Error, _T("LDAP: Failed to get interface address for the destination.\n")); return HRESULT_FROM_WIN32 (Error); }
} // based on the source address of the socket, we decide whether the connection
// came from an internal or external client. this will govern later decisions
// on how the call is routed.
#if DBG
BOOL IsPrivateOrLocalSource; BOOL IsPublicDestination;
Result = ::IsPrivateAddress (ntohl (RedirectInformation.SourceAddress), &IsPrivateOrLocalSource);
if (S_OK != Result) {
return Result; }
IsPrivateOrLocalSource = IsPrivateOrLocalSource || ::NhIsLocalAddress (RedirectInformation.SourceAddress);
Result = ::IsPublicAddress (ntohl (RedirectInformation.DestinationAddress), &IsPublicDestination);
if (S_OK != Result) {
return Result;
}
if (::NhIsLocalAddress (RedirectInformation.SourceAddress) && ::NhIsLocalAddress (RedirectInformation.DestinationAddress)) {
Debug (_T("Q931: New LOCAL connection.\n"));
} else {
if (IsPrivateOrLocalSource && IsPublicDestination) {
Debug (_T("Q931: New OUTBOUND connection.\n"));
} else {
Debug (_T("Q931: New INBOUND connection.\n")); } }#endif // DBG
DebugF (_T("Q931: Connection redirected: (%08X:%04X -> %08X:%04X) => (%08X:%04X -> %08X:%04X).\n"), ntohl (RedirectInformation.SourceAddress), ntohs (RedirectInformation.SourcePort), ntohl (RedirectInformation.DestinationAddress), ntohs (RedirectInformation.DestinationPort), ntohl (RedirectInformation.NewSourceAddress), ntohs (RedirectInformation.NewSourcePort), ntohl (RedirectInformation.NewDestinationAddress), ntohs (RedirectInformation.NewDestinationPort));
CallBridge = new CALL_BRIDGE (&RedirectInformation);
if (!CallBridge) {
DebugF (_T("Q931: Failed to allocate CALL_BRIDGE.\n"));
return E_OUTOFMEMORY; }
CallBridge -> AddRef ();
// Add the call-bridge to the list. Doing so makes an additional reference
// to the object, which is retained until the object is destroyed by calling
// RemoveCallBridge.
if (CallBridgeList.InsertCallBridge (CallBridge) == S_OK) {
// should we check the local address or the caller's address ?
// The problem is that if someone tries to connect to the
// external IP address from inside, they will still probably succeed
Result = CallBridge -> Initialize ( Socket, LocalAddress, RemoteAddress, &RedirectInformation ); if (Result != S_OK) {
CallBridge -> TerminateExternal ();
DebugF (_T("Q931: 0x%x accepted new client, but failed to initialize.\n"), CallBridge);
// Probably there was something wrong with just this
// Init failure. Continue to accept more Q.931 connections.
} }
CallBridge -> Release ();
return Result;}
HRESULTQ931CreateBindSocket ( void ){ HRESULT Result; SOCKADDR_IN SocketAddress;
SocketAddress.sin_family = AF_INET; SocketAddress.sin_addr.s_addr = htonl (INADDR_LOOPBACK); SocketAddress.sin_port = htons (0); // request dynamic port
Result = Q931AsyncAccept.StartIo ( &SocketAddress, Q931AsyncAcceptFunction, NULL );
if (Result != S_OK) {
DebugError (Result, _T("Q931: Failed to create and bind socket.\n"));
return Result; }
DebugF (_T("Q931: Asynchronous Accept started.\n"));
Result = Q931AsyncAccept.GetListenSocketAddress (&Q931ListenSocketAddress);
if (Result != S_OK) {
DebugError (Result, _T("Q931: Failed to get listen socket address.\n"));
return Result;
}
return S_OK;}
void Q931CloseSocket ( void ){ ZeroMemory ((PVOID)&Q931ListenSocketAddress, sizeof (SOCKADDR_IN));
Q931AsyncAccept.StopWait (); }
HRESULT Q931StartLoopbackRedirect ( void ) { NTSTATUS Status;
Status = NatCreateDynamicAdapterRestrictedPortRedirect ( NatRedirectFlagLoopback | NatRedirectFlagSendOnly, IPPROTO_TCP, htons (Q931_TSAP_IP_TCP), Q931ListenSocketAddress.sin_addr.s_addr, Q931ListenSocketAddress.sin_port, ::NhMapAddressToAdapter (htonl (INADDR_LOOPBACK)), MAX_LISTEN_BACKLOG, &Q931LoopbackRedirectHandle);
if (Status != STATUS_SUCCESS) {
Q931LoopbackRedirectHandle = NULL;
DebugError (Status, _T("Q931: Failed to create local dynamic redirect.\n")); return (HRESULT)Status; }
DebugF (_T("Q931: Connections traversing loopback interface to port %04X will be redirected to %08X:%04X.\n"), Q931_TSAP_IP_TCP, SOCKADDR_IN_PRINTF (&Q931ListenSocketAddress));
return (HRESULT) Status;}
void Q931StopLoopbackRedirect ( void ) { if (Q931LoopbackRedirectHandle) {
NatCancelDynamicRedirect (Q931LoopbackRedirectHandle);
Q931LoopbackRedirectHandle = NULL; }}
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