/*==========================================================================
 *
 *  Copyright (C) 2001 Microsoft Corporation.  All Rights Reserved.
 *
 *  File:       nathelp.c
 *  Content:   usage for nat helper DLL
 *
 *  History:
 *  Date			By		Reason
 *  ====			==		======
 *  02/22/2001		aarono	Original
 *  04/16/2001		vanceo	Use one of the split DirectPlayNATHelp interfaces only.
 *
 *  Notes:
 *   
 ***************************************************************************/


#define INCL_WINSOCK_API_TYPEDEFS 1 // includes winsock 2 fn proto's, for getprocaddress
#define FD_SETSIZE 1
#include <winsock2.h>
#include "dpsp.h"
#include "mmsystem.h"
#if USE_NATHELP

#include "dpnathlp.h"

BOOL natGetCapsUpdate(LPGLOBALDATA pgd)
{
	HRESULT hr;
	//
	// Get Nat Capabilities - may block for a second.
	//
	
	memset(&pgd->NatHelpCaps,0,sizeof(DPNHCAPS));
	pgd->NatHelpCaps.dwSize=sizeof(DPNHCAPS);
	hr=IDirectPlayNATHelp_GetCaps(pgd->pINatHelp, &pgd->NatHelpCaps, DPNHGETCAPS_UPDATESERVERSTATUS);
	
	if(FAILED(hr))
	{
		DPF(0,"NatHelp failed to GetCaps, hr=%x\n",hr);
		return FALSE;
	}

	if (hr == DPNHSUCCESS_ADDRESSESCHANGED)
	{
		DPF(1,"NAT Help reports addresses changed, possible connection problems may occur.");
	}

	return TRUE;

}

/*=============================================================================

	natInit	- Initialize nat helper i/f
	
    Description:


    Parameters:

    	pgd  - Service Provider's global data blob for this instance

    Return Values:


-----------------------------------------------------------------------------*/
BOOL natInit(LPGLOBALDATA pgd,LPGUID lpguidSP)
{
	HRESULT hr;
	char szNATHelpPath[256];
	PFN_DIRECTPLAYNATHELPCREATE pfnNatHelpCreate = NULL;
	char *apszNATHelps[3];
	HMODULE ahNatHelps[3];
	IDirectPlayNATHelp *apINatHelps[3];
	DPNHCAPS adpnhcNatHelpCaps[3];
	DWORD dwNumNatHelps = 0;
	DWORD dwCurrentNatHelp;


	pgd->hNatHelp = NULL;
	pgd->pINatHelp = NULL;

	pgd->hNatHelpTCP = 0;
	pgd->hNatHelpUDP = 0;

    // build an internet INADDRANY
    memset(&pgd->INADDRANY,0,sizeof(SOCKADDR));
    pgd->INADDRANY.sa_family=AF_INET;


	memset(ahNatHelps, 0, sizeof(ahNatHelps));
	memset(apINatHelps, 0, sizeof(apINatHelps));

	//
	// See if there's a registry setting.
	//
	hr = GetNATHelpDLLFromRegistry((LPGUID) (&DPSPGUID_TCPIP), szNATHelpPath, 256);
	if (hr == S_OK)
	{
		DPF(1, "Got NAT Help DLL \"%s\" from registry.\n", szNATHelpPath);
		apszNATHelps[dwNumNatHelps++] = szNATHelpPath;
	}
	else
	{
		DPF(4, "Couldn't get NAT Help DLL from registry, hr=%x.\n", hr);
	}

	//
	// Add the default entries if the registry didn't already specify them.
	//
	if (_strnicmp(szNATHelpPath + strlen(szNATHelpPath) - strlen("dpnhupnp.dll"), "dpnhupnp.dll", strlen("dpnhupnp.dll")) != 0)
	{
		apszNATHelps[dwNumNatHelps++] = "dpnhupnp.dll";
	}
	if (_strnicmp(szNATHelpPath + strlen(szNATHelpPath) - strlen("dpnhpast.dll"), "dpnhpast.dll", strlen("dpnhpast.dll")) != 0)
	{
		apszNATHelps[dwNumNatHelps++] = "dpnhpast.dll";
	}

	//
	// Loop through the registry specified and default NAT Helpers and attempt
	// to load them.
	//
	for(dwCurrentNatHelp = 0; dwCurrentNatHelp < dwNumNatHelps; dwCurrentNatHelp++)
	{
		pgd->hNatHelp = LoadLibrary(apszNATHelps[dwCurrentNatHelp]);
		if (pgd->hNatHelp != NULL)
		{
			pfnNatHelpCreate = (PFN_DIRECTPLAYNATHELPCREATE) GetProcAddress(pgd->hNatHelp,
																		"DirectPlayNATHelpCreate");
			if (pfnNatHelpCreate != NULL)
			{
				hr = pfnNatHelpCreate(&IID_IDirectPlayNATHelp, (void **) (&pgd->pINatHelp));
				if (hr == DP_OK)
				{
					//
					// Initialize the NAT Helper interface.
					//		
					hr = IDirectPlayNATHelp_Initialize(pgd->pINatHelp, 0);
					if (hr == DP_OK)
					{
						//
						// Get the capabilities.  If it succeeds, remember the information and move on.
						//
						if (natGetCapsUpdate(pgd))
						{
							DPF(3, "Successfully retrieved caps for NAT Help \"%s\", flags = 0x%x.",
								apszNATHelps[dwCurrentNatHelp], pgd->NatHelpCaps.dwFlags);
							ahNatHelps[dwCurrentNatHelp] = pgd->hNatHelp;
							pgd->hNatHelp = NULL;
							apINatHelps[dwCurrentNatHelp] = pgd->pINatHelp;
							pgd->pINatHelp = NULL;
							memcpy(&adpnhcNatHelpCaps[dwCurrentNatHelp], &pgd->NatHelpCaps, sizeof(DPNHCAPS));
							continue;
						}
						else
						{
							DPF(0, "Couldn't get NAT Help \"%s\" caps, hr=%x!", apszNATHelps[dwCurrentNatHelp], hr);
						}
						
						IDirectPlayNATHelp_Close(pgd->pINatHelp, 0);
					}
					else
					{
						DPF(0, "NAT Help \"%s\" failed to initialize, hr=%x!", apszNATHelps[dwCurrentNatHelp], hr);
					}
					
					IDirectPlayNATHelp_Release(pgd->pINatHelp);
					pgd->pINatHelp = NULL;
				}
				else
				{
					DPF(0, "Couldn't create NAT Help \"%s\" interface, hr = %x!", apszNATHelps[dwCurrentNatHelp], hr);
				}
			}
			else
			{
				DPF(0, "Couldn't get NAT Help DLL \"%s\" entry point!", apszNATHelps[dwCurrentNatHelp]);
			}
			
			FreeLibrary(pgd->hNatHelp);
			pgd->hNatHelp = NULL;
		}
		else
		{
			DPF(0, "Couldn't load NAT Help DLL \"%s\"!", apszNATHelps[dwCurrentNatHelp]);
		}
	}


	//
	// Now go through and pick the first helper that detected a NAT.
	//
	for(dwCurrentNatHelp = 0; dwCurrentNatHelp < dwNumNatHelps; dwCurrentNatHelp++)
	{
		if ((apINatHelps[dwCurrentNatHelp] != NULL) &&
			(adpnhcNatHelpCaps[dwCurrentNatHelp].dwFlags & DPNHCAPSFLAG_GATEWAYPRESENT))
		{
			DPF(2, "Gateway detected by NAT Help \"%s\", flags = 0x%x.",
				apszNATHelps[dwCurrentNatHelp], adpnhcNatHelpCaps[dwCurrentNatHelp].dwFlags);
			pgd->hNatHelp = ahNatHelps[dwCurrentNatHelp];
			ahNatHelps[dwCurrentNatHelp] = NULL;
			pgd->pINatHelp = apINatHelps[dwCurrentNatHelp];
			apINatHelps[dwCurrentNatHelp] = NULL;
			memcpy(&pgd->NatHelpCaps, &adpnhcNatHelpCaps[dwCurrentNatHelp], sizeof(DPNHCAPS));
			break;
		}
	}

	//
	// If we didn't get a helper that way, pick the first one that detected a firewall.
	//
	if (pgd->pINatHelp != NULL)
	{
		for(dwCurrentNatHelp = 0; dwCurrentNatHelp < dwNumNatHelps; dwCurrentNatHelp++)
		{
			if ((apINatHelps[dwCurrentNatHelp] != NULL) &&
				(adpnhcNatHelpCaps[dwCurrentNatHelp].dwFlags & DPNHCAPSFLAG_LOCALFIREWALLPRESENT))
			{
				DPF(2, "Firewall detected by NAT Help \"%s\", flags = 0x%x.",
					apszNATHelps[dwCurrentNatHelp], adpnhcNatHelpCaps[dwCurrentNatHelp].dwFlags);
				pgd->hNatHelp = ahNatHelps[dwCurrentNatHelp];
				ahNatHelps[dwCurrentNatHelp] = NULL;
				pgd->pINatHelp = apINatHelps[dwCurrentNatHelp];
				apINatHelps[dwCurrentNatHelp] = NULL;
				memcpy(&pgd->NatHelpCaps, &adpnhcNatHelpCaps[dwCurrentNatHelp], sizeof(DPNHCAPS));
				break;
			}
		}
	}

	//
	// Now go through and release all the other NAT helpers, or pick the first one that
	// successfully loaded if we didn't pick one already.
	//
	for(dwCurrentNatHelp = 0; dwCurrentNatHelp < dwNumNatHelps; dwCurrentNatHelp++)
	{
		if (apINatHelps[dwCurrentNatHelp] != NULL)
		{
			if (pgd->pINatHelp == NULL)
			{
				DPF(2, "Using first loaded NAT Help \"%s\", flags = 0x%x.",
					apszNATHelps[dwCurrentNatHelp], adpnhcNatHelpCaps[dwCurrentNatHelp].dwFlags);
				pgd->hNatHelp = ahNatHelps[dwCurrentNatHelp];
				ahNatHelps[dwCurrentNatHelp] = NULL;
				pgd->pINatHelp = apINatHelps[dwCurrentNatHelp];
				apINatHelps[dwCurrentNatHelp] = NULL;
				memcpy(&pgd->NatHelpCaps, &adpnhcNatHelpCaps[dwCurrentNatHelp], sizeof(DPNHCAPS));
			}
			else
			{
				IDirectPlayNATHelp_Close(apINatHelps[dwCurrentNatHelp], 0);
				IDirectPlayNATHelp_Release(apINatHelps[dwCurrentNatHelp]);
				apINatHelps[dwCurrentNatHelp] = NULL;
				FreeLibrary(ahNatHelps[dwCurrentNatHelp]);
				ahNatHelps[dwCurrentNatHelp] = NULL;
			}
		}
	}

	if (pgd->pINatHelp == NULL)
	{
		DPF(1, "No NAT Help loaded.");
		pgd->NatHelpCaps.dwRecommendedGetCapsInterval = INFINITE;
		return FALSE;
	}

#ifdef DEBUG
	if (! (pgd->NatHelpCaps.dwFlags & DPNHCAPSFLAG_PUBLICADDRESSAVAILABLE))
	{
		DPF(1, "NAT Help loaded, no NAT/firewall detected, or it doesn't currently have a public address (flags = 0x%x).",
			pgd->NatHelpCaps.dwFlags);
	}
#endif // DEBUG

	return TRUE;
}

/*=============================================================================

	natFini - Shut down NATHELP support
	
	
    Description:


    Parameters:

    	pgd  - Service Provider's global data blob for this instance

    Return Values:

		None.

-----------------------------------------------------------------------------*/
VOID natFini(LPGLOBALDATA pgd)
{

	// natDeregisterPorts(pgd); - vance says we don't need to do this.
	if(pgd->pINatHelp)
	{
        IDirectPlayNATHelp_Close(pgd->pINatHelp, 0);
    	pgd->hNatHelpTCP = 0;
	    pgd->hNatHelpUDP = 0;
		IDirectPlayNATHelp_Release(pgd->pINatHelp);
		pgd->pINatHelp=NULL;
	}	

	if(pgd->hNatHelp)
	{
		FreeLibrary(pgd->hNatHelp);
		pgd->hNatHelp=NULL;
	}
		
}

/*=============================================================================

	natRegisterPort - Get a port mapping.
	
	
    Description:

		Note only one mapping each for TCP and UDP are supported (for simplicity).

    Parameters:

    	pgd  - Service Provider's global data blob for this instance

    Return Values:

		None.

-----------------------------------------------------------------------------*/
HRESULT natRegisterPort(LPGLOBALDATA pgd, BOOL ftcp_udp, WORD port)
{
	SOCKADDR_IN 	sockaddr_in, sockaddr_inpublic;
	DWORD			dwFlags, dwSize;
	DPNHHANDLE		hPortMapping;
	HRESULT 		hr=DP_OK;
	
	memset(&sockaddr_in , 0 ,sizeof(sockaddr_in));
	sockaddr_in.sin_family          = AF_INET;
	sockaddr_in.sin_addr.S_un.S_addr= INADDR_ANY;
	sockaddr_in.sin_port            = htons(port);

	if (ftcp_udp)
	{
		dwFlags = DPNHREGISTERPORTS_TCP;
	}
	else
	{
		dwFlags = 0;
	}

	hr=IDirectPlayNATHelp_RegisterPorts(pgd->pINatHelp, (SOCKADDR *)&sockaddr_in, sizeof(sockaddr_in), 1, 15*60000, &hPortMapping, dwFlags);
	if (hr != DPNH_OK)
	{
		DPF(0,"NATHelp_RegisterPorts registration failed, hr=%x",hr);
		hr = DPERR_GENERIC;
	}
	else
	{
		dwSize=sizeof(sockaddr_inpublic);
		hr = IDirectPlayNATHelp_GetRegisteredAddresses(pgd->pINatHelp, hPortMapping, (SOCKADDR *)&sockaddr_inpublic, &dwSize, NULL, NULL, 0);
		switch (hr)
		{
			case DPNH_OK:
			{
	      		DPF(2, "NATHelp successfully mapped port to %s:%u.",
	      			inet_ntoa(sockaddr_inpublic.sin_addr), ntohs(sockaddr_inpublic.sin_port) );
	      		
				if (ftcp_udp)
				{
					ASSERT(!pgd->hNatHelpTCP);
					if(pgd->hNatHelpTCP)
					{
						DPF(0,"WARNING: trying to map a TCP connection when one is already mapped?\n");
					}
					pgd->hNatHelpTCP=hPortMapping;
					
					memcpy(&pgd->saddrpubSystemStreamSocket, &sockaddr_inpublic, sizeof(SOCKADDR_IN));
				}
				else
				{
					ASSERT(!pgd->hNatHelpUDP);
					if (pgd->hNatHelpUDP)
					{
						DPF(0,"WARNING: trying to map a UDP connection when one is already mapped?\n");
					}
					pgd->hNatHelpUDP=hPortMapping;
					
					memcpy(&pgd->saddrpubSystemDGramSocket, &sockaddr_inpublic, sizeof(SOCKADDR_IN));
				}
				break;
			}
			
			case DPNHERR_PORTUNAVAILABLE:
			{
	      		DPF(0, "NATHelp reported port %u is unavailable!", port);
		    		
				hr=IDirectPlayNATHelp_DeregisterPorts(pgd->pINatHelp, hPortMapping, 0);
				if (hr != DP_OK)
				{
					DPF(0,"NATHelp_DeregisterPorts returned %x\n",hr);
				}
				
				hr = DPNHERR_PORTUNAVAILABLE;
				break;
			}
			
			default:
			{
		    	DPF(1, "NATHelp couldn't map port %u, (err = 0x%lx).", port, hr);
		    	
				if (ftcp_udp)
				{
					ASSERT(!pgd->hNatHelpTCP);
					if(pgd->hNatHelpTCP)
					{
						DPF(0,"WARNING: trying to map a TCP connection when one is already mapped?\n");
					}
					pgd->hNatHelpTCP=hPortMapping;
				}
				else
				{
					ASSERT(!pgd->hNatHelpUDP);
					if (pgd->hNatHelpUDP)
					{
						DPF(0,"WARNING: trying to map a UDP connection when one is already mapped?\n");
					}
					pgd->hNatHelpUDP=hPortMapping;
				}

				hr = DPERR_GENERIC;
				break;
			}
		}
	}
	
	return hr;
}


/*=============================================================================

	natDeregisterPort - Get rid of either UDP or TCP port mappings
	
	
    Description:


    Parameters:

    	pgd  - Service Provider's global data blob for this instance

    Return Values:

		None.

-----------------------------------------------------------------------------*/
VOID natDeregisterPort(LPGLOBALDATA pgd, BOOL ftcp_udp)
{
	HRESULT hr;

	if(ftcp_udp && pgd->hNatHelpTCP){
	    DPF(8,"Deregister TCP port\n");
		hr=IDirectPlayNATHelp_DeregisterPorts(pgd->pINatHelp, pgd->hNatHelpTCP, 0);
		if(hr!=DP_OK){
			DPF(0,"NATHelp_DeRegisterPorts returned %x\n",hr);
		}
		pgd->hNatHelpTCP=0;

		memset(&pgd->saddrpubSystemStreamSocket, 0, sizeof(SOCKADDR_IN));
	}
	if(!ftcp_udp && pgd->hNatHelpUDP){
	    DPF(8,"Deregistering UDP port\n");
		hr=IDirectPlayNATHelp_DeregisterPorts(pgd->pINatHelp, pgd->hNatHelpUDP, 0);
		if(hr!=DP_OK){
			DPF(0,"NATHelp_DeRegisterPorts returned %x\n",hr);
		}
		pgd->hNatHelpUDP=0;

		memset(&pgd->saddrpubSystemDGramSocket, 0, sizeof(SOCKADDR_IN));
	}	
}




/*=============================================================================

	natIsICSMachine - Return TRUE if this machine is a Windows ICS machine, FALSE otherwise
	
	
    Description:


    Parameters:

    	pgd  - Service Provider's global data blob for this instance

    Return Values:

		None.

-----------------------------------------------------------------------------*/
BOOL natIsICSMachine(LPGLOBALDATA pgd)
{
	if (pgd->pINatHelp != NULL)
	{
		if ((pgd->NatHelpCaps.dwFlags & DPNHCAPSFLAG_GATEWAYPRESENT) &&
			(pgd->NatHelpCaps.dwFlags & DPNHCAPSFLAG_GATEWAYISLOCAL))
		{
			DPF(1, "Local internet gateway present, flags = 0x%x.", pgd->NatHelpCaps.dwFlags);
			return TRUE;
		}
		else
		{
			DPF(1, "No local internet gateway present, flags = 0x%x.", pgd->NatHelpCaps.dwFlags);
		}
	}
	else
	{
		DPF(1, "NAT Help not loaded.");
	}

	return FALSE;
}

#endif