PcapFilter.h File Reference

#include <string>
#include <vector>
#include <memory>
#include "ProtocolType.h"
#include <stdint.h>
#include "ArpLayer.h"

Go to the source code of this file.

Classes
class	pcpp::GeneralFilter
class	pcpp::BPFStringFilter
class	pcpp::IFilterWithDirection
class	pcpp::IFilterWithOperator
class	pcpp::IPFilter
class	pcpp::IPv4IDFilter
class	pcpp::IPv4TotalLengthFilter
class	pcpp::PortFilter
class	pcpp::PortRangeFilter
class	pcpp::MacAddressFilter
class	pcpp::EtherTypeFilter
class	pcpp::AndFilter
class	pcpp::OrFilter
class	pcpp::NotFilter
class	pcpp::ProtoFilter
class	pcpp::ArpFilter
class	pcpp::VlanFilter
class	pcpp::TcpFlagsFilter
class	pcpp::TcpWindowSizeFilter
class	pcpp::UdpLengthFilter

Namespaces
	pcpp
	The main namespace for the PcapPlusPlus lib.

Enumerations
enum	pcpp::Direction { pcpp::SRC, pcpp::DST, pcpp::SRC_OR_DST }
enum	pcpp::FilterOperator {   pcpp::EQUALS, pcpp::NOT_EQUALS, pcpp::GREATER_THAN, pcpp::GREATER_OR_EQUAL,   pcpp::LESS_THAN, pcpp::LESS_OR_EQUAL }

Detailed Description

Most packet capture engines contain packet filtering capabilities. In order to set the filters there should be a known syntax user can use. The most popular syntax is Berkeley Packet Filter (BPF) - see more in here: http://en.wikipedia.org/wiki/Berkeley_Packet_Filter. Detailed explanation of the syntax can be found here: http://www.tcpdump.org/manpages/pcap-filter.7.html.
The problem with BPF is that, for my opinion, the syntax is too complicated and too poorly documented. In addition the BPF filter compilers may output syntax errors that are hard to understand. My experience with BPF was not good, so I decided to make the filters mechanism more structured, easier to understand and less error-prone by creating classes that represent filters. Each possible filter phrase is represented by a class. The filter, at the end, is that class.
For example: the filter "src host 1.1.1.1" will be represented by IPFilter instance; "dst port 80" will be represented by PortFilter, and so on.
So what about complex filters that involve "and", "or"? There are also 2 classes: AndFilter and OrFilter that can store more filters (in a composite idea) and connect them by "and" or "or". For example: "src host 1.1.1.1 and dst port 80" will be represented by an AndFilter that h olds IPFilter and PortFilter inside it