protected static int IPSecCreateFilterData(IntPtr hStore, IPSEC_FILTER_DATA ipsecFilterData)
{
IntPtr pExampleFilterData = Marshal.AllocHGlobal(Marshal.SizeOf(ipsecFilterData));
Marshal.StructureToPtr(ipsecFilterData, pExampleFilterData, false);
int hr = IPSecCreateFilterData(hStore, pExampleFilterData);
Marshal.FreeHGlobal(pExampleFilterData);
return(hr);
}
protected static int IPSecGetFilterData(IntPtr hStore, Guid filterGuid, out IPSEC_FILTER_DATA ipsecFilterData)
{
ipsecFilterData = new IPSEC_FILTER_DATA();
//Allocate memory for the struct pointer.
IntPtr ppIpsecFilterData = Marshal.AllocHGlobal(Marshal.SizeOf(new IntPtr()));
int hr = IPSecGetFilterData(hStore, filterGuid, ppIpsecFilterData);
if (hr != 0)
{
return(hr);
}
//Dereference the ppIpsecISAKMPData into a pointer.
IntPtr pIpsecFilterData = Marshal.ReadIntPtr(ppIpsecFilterData);
ipsecFilterData = (IPSEC_FILTER_DATA)Marshal.PtrToStructure(pIpsecFilterData, typeof(IPSEC_FILTER_DATA));
Marshal.FreeHGlobal(ppIpsecFilterData);
return(hr);
}
/// <summary>
/// Creates a filter with the specified ports.
/// </summary>
/// <param name="name">The name to give the filter .</param>
/// <param name="ports">The ports to use in the filter .</param>
/// <param name="ipsecFilterData">An out struct to return the data.</param>
/// <param name="description">The description to give the filter .</param>
/// <returns>>A WinError System Error Code.</returns>
private int CreatePortFilter(string name, Port[] ports, out IPSEC_FILTER_DATA ipsecFilterData, string description = "")
{
//Initialize.
ipsecFilterData = new IPSEC_FILTER_DATA()
{
pszIpsecName = name,
pszIpsecDescription = description,
dwNumFilterSpecs = ports.Length,
ppFilterSpecs = IntPtr.Zero,
dwWhenChanged = (int)new DateTimeOffset(DateTime.Now).ToUnixTimeSeconds(),
FilterIdentifier = Guid.NewGuid(),
};
//Create an array of filter specs for each specified port.
IPSEC_FILTER_SPEC[] filterSpecs = new IPSEC_FILTER_SPEC[ports.Length];
//Create an array of pointers to allocation.
IntPtr[] pFilterSpecs = new IntPtr[ports.Length];
for (int i = 0; i < ports.Length; i++)
{
//Initialize a spec.
filterSpecs[i] = new()
{
dwMirrorFlag = 0x0,
FilterSpecGUID = Guid.NewGuid(),
pszDescription = "",
pszSrcDNSName = "",
filter = new NativeMethods.Ipsec.IPSEC_FILTER
{
Flags = 0x0,
Pad = '\0',
TunnelAddr = 0,
TunnelFilter = false
}
};
if (ports[i].portType == PortType.TCP)
{
filterSpecs[i].filter.DstPort = ports[i].port;
filterSpecs[i].filter.Protocol = (int)PortType.TCP;
filterSpecs[i].filter.DstUnknownFlag1 = 0x1;
}
else
{
filterSpecs[i].filter.SrcPort = ports[i].port;
filterSpecs[i].filter.Protocol = (int)PortType.UDP;
filterSpecs[i].dwMirrorFlag = 0x1;
filterSpecs[i].filter.SrcUnknownFlag1 = 0x1;
}
//Marshal the struct to a pointer.
pFilterSpecs[i] = Marshal.AllocHGlobal(Marshal.SizeOf(filterSpecs[i]));
Marshal.StructureToPtr(filterSpecs[i], pFilterSpecs[i], false);
}
//Create the 2d pointer and write the struct pointers sequentially next to each other.
IntPtr ppFilterSpecs = Marshal.AllocHGlobal(IntPtr.Size * ports.Length);
IntPtr ptrCopy = ppFilterSpecs;
for (int i = 0; i < ports.Length; i++)
{
Marshal.WriteIntPtr(ptrCopy, pFilterSpecs[i]);
ptrCopy += IntPtr.Size;
}
ipsecFilterData.ppFilterSpecs = ppFilterSpecs;
//Call the FriendlyMethod native.
int hr = IPSecCreateFilterData(hStore, ipsecFilterData);
//Free unmanaged memory.
for (int i = 0; i < ports.Length; i++)
{
Marshal.FreeHGlobal(pFilterSpecs[i]);
}
Marshal.FreeHGlobal(ppFilterSpecs);
return(hr);
}
