/// <summary>
/// Constructor
/// </summary>
/// <param name="linkLayerType">
/// A <see cref="GodLesZ.Library.Network.Packet.LinkLayers"/>
/// </param>
/// <param name="snapshotLength">
/// A <see cref="System.Nullable<System.Int32>"/>
/// </param>
/// <param name="captureFilename">
/// A <see cref="System.String"/>
/// </param>
/// <param name="mode">
/// A <see cref="FileMode"/>
/// </param>
public CaptureFileWriterDevice(GodLesZ.Library.Network.Packet.LinkLayers linkLayerType,
int?snapshotLength,
string captureFilename,
FileMode mode)
{
m_pcapFile = captureFilename;
// append isn't possible without some difficulty and not implemented yet
if (mode == FileMode.Append)
{
throw new System.InvalidOperationException("FileMode.Append is not supported, please contact the developers if you are interested in helping to implementing it");
}
if (!snapshotLength.HasValue)
{
snapshotLength = Pcap.MAX_PACKET_SIZE;
}
else if (snapshotLength > Pcap.MAX_PACKET_SIZE)
{
throw new System.InvalidOperationException("snapshotLength > Pcap.MAX_PACKET_SIZE");
}
// set the device handle
PcapHandle = LibPcapSafeNativeMethods.pcap_open_dead((int)linkLayerType, snapshotLength.Value);
m_pcapDumpHandle = LibPcapSafeNativeMethods.pcap_dump_open(PcapHandle, captureFilename);
if (m_pcapDumpHandle == IntPtr.Zero)
{
throw new PcapException("Error opening dump file '" + LastError + "'");
}
}
/// <summary>
/// Returns true if the filter expression was able to be compiled into a
/// program without errors
/// </summary>
public static bool CheckFilter(string filterExpression,
out string errorString)
{
IntPtr bpfProgram;
IntPtr fakePcap = LibPcapSafeNativeMethods.pcap_open_dead((int)GodLesZ.Library.Network.Packet.LinkLayers.Ethernet, Pcap.MAX_PACKET_SIZE);
uint mask = 0;
if (!CompileFilter(fakePcap, filterExpression, mask, out bpfProgram, out errorString))
{
LibPcapSafeNativeMethods.pcap_close(fakePcap);
return(false);
}
FreeBpfProgram(bpfProgram);
LibPcapSafeNativeMethods.pcap_close(fakePcap);
return(true);
}