packet-filter.h

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/*
 * Copyright (c) 2016 Universita' degli Studi di Napoli Federico II
 *
 * SPDX-License-Identifier: GPL-2.0-only
 */
 
#ifndef PACKET_FILTER_H
#define PACKET_FILTER_H
 
#include "ns3/object.h"
 
namespace ns3
{
 
class QueueDiscItem;
 
/**
 * \ingroup traffic-control
 *
 * PacketFilter is the abstract base class for filters used by queue discs
 * to classify packets.
 */
class PacketFilter : public Object
{
  public:
    /**
     * \brief Get the type ID.
     * \return the object TypeId
     */
    static TypeId GetTypeId();
 
    PacketFilter();
    ~PacketFilter() override;
 
    /**
     * Standard value used by packet filters to indicate that no match was possible.
     */
    static const int PF_NO_MATCH = -1;
 
    /**
     * \brief Classify a packet.
     *
     * \param item the packet to classify.
     *
     * \return -1 if this filter is not able to classify packets of the same protocol
     * as item or the item does not match the filter conditions, the configured return
     * value otherwise.
     */
    int32_t Classify(Ptr<QueueDiscItem> item) const;
 
  private:
    /**
     * \brief Checks if the filter is able to classify a kind of items.
     *
     * \param item an example item to check.
     * \return true if this filter is able to classify packets.
     */
    virtual bool CheckProtocol(Ptr<QueueDiscItem> item) const = 0;
 
    /**
     * \brief Classify a packet.
     *
     * \param item the packet to classify.
     *
     * \return -1 if the item does not match the filter conditions, or the configured
     * return value otherwise.
     */
    virtual int32_t DoClassify(Ptr<QueueDiscItem> item) const = 0;
};
 
} // namespace ns3
 
#endif /* PACKET_FILTER */