CCats/daemon/include/CovertChannel.h

#ifndef SNIFFER_H
#define SNIFFER_H

#include <tins/tins.h>

/**
 * @class Sniffer
 *
 * Sniffs the network.
 *
 * Sniffer class which will sniff on a network interface. It is supposed to
 * forward the packets to an analyzer or modifyer so we can hide data in the
 * traffic.
 */
class CovertChannel {
public:
	/**
	 * Creates a Sniffer.
	 *
	 * Creates a Sniffer and sets the network interface for sniffing.
	 *
	 * @param interface name of the interface for sniffing
	 */
	CovertChannel(const std::string &innerInterface, const std::string &outerInterface);

	/**
	 * Destroys the Sniffer.
	 *
	 * Destructor of the Sniffer.
	 */
	virtual ~CovertChannel();

	/**
	 * Start sniffing on the interface.
	 *
	 * Starts a sniffing loop which calls handle. The loop will only be stopped if
	 * handle returns false.
	 */
	void startSniffing();

	/**
	 * Sets a filter for the sniffer.
	 *
	 * Sets the filter for a sniffer with a pcap filter string. E.g. "ip
	 * dst 8.8.8.8".
	 *
	 * @param filterString pcap filter string
	 */
	void setFilter(const std::string &filterString);

protected:
	/**
	 * Handler for sniffed packets.
	 *
	 * Handles incoming connections and provides data for the package analyzer and
	 * modifyer.
	 *
	 * @param pdu sniffed packet
	 *
	 * @return false = stop loop | true = continue loop
	 */
	// bool handle(Tins::PDU &pdu);

	bool handleForwardToInner(Tins::PDU &pdu);
	bool handleForwardToOuter(Tins::PDU &pdu);
	virtual bool handleRedirectToInner(Tins::PDU &pdu) = 0;
	virtual bool handleRedirectToOuter(Tins::PDU &pdu) = 0;

	void startInnerSniffing();
	void startOuterSniffing();

	/**
	 * Tins sniffer object.
	 */
	Tins::Sniffer *innerSniffer;
	Tins::Sniffer *outerSniffer;
	Tins::PacketSender innerSender;
	Tins::PacketSender outerSender;
};

#endif