ARCHITECTURE

SharpPcap Architecture
Chris Morgan <chmorgan@gmail.com>

Questions or comments about this or any other document, code file etc
can be directed to the SharpPcap project website, http://sharppcap.sf.net or to
chmorgan@gmail.com.

This document is intended to describe the high level architecture of
the SharpPcap assembly to provide some insight into the namespaces and
class layout of the project and how to use the various classes.

There are four major namespaces in SharpPcap:

SharpPcap
SharpPcap.LibPcap
SharpPcap.WinPcap
SharpPcap.AirPcap

These correspond to the directories:

SharpPcap/
    LibPcap/
    WinPcap/
    AirPcap/

While at the same level, these directories are a hierarchy of functionality

SharpPcap/ - Base level defines, interfaces to capture devices (ICaptureDevie)
             and high level classes for retrieving a list of ICaptureDevice entries
    LibPcap/ - libpcap functionality, background capture code etc
        WinPcap/ - WinPcap functionality. WinPcap adds several extension methods
                   that aren't present in libpcap. WinPcap adapters are inherited
                   from LibPcap adapters to add this functionality.
            AirPcap/ - AirPcap functionality. AirPcap adapters are inherited from
                       WinPcap adapters and have additional methods for retrieving
                       channel frequency, strength, etc that aren't present in
                       WinPcap or LibPcap adapters

Two usage cases.

1. You want to retrieve a list of all capture devices and maybe for specific
   types of capture devices you want to do something custom with them like
   adjusting the capture channel for AirPcap adapters

- You should use the CaptureDeviceList and in your code do something like:

  var captureDevices = SharpPcap.CaptureDeviceList.Instance;
  foreach(var dev in captureDevices)
  {
    if(dev is SharpPcap.AirPcap.AirPcapDevice)
    {
      var airPcapDevice = (SharpPcap.AirPcap.AirPcapDevice)dev;
      // Now you can use the AirPcap specific additions here
    }
 ...


2. You know you want to get a list of specific devices, say AirPcap adapters, and
   you don't want to see the other kinds of adapters

- You can use the technique in #1 and simply ignore the ones that aren't the type you want
or
- You can use the type specific lists such as SharpPcap.AirPcap.AirPcapDeviceList or
  SharpPcap.WinPcap.WinPcapDeviceList or SharpPcap.LibPcap.LibPcapDeviceList. These
  classes will return adapters of a specific type. Note that because
  AirPcap adapters are WinPcap adapters which are LibPcap adapters that LibPcapDeviceList
  WILL contain the available AirPcap adapters as those show up as pcap capture devices.