/*
 * Copyright 2003-2005, Haiku Inc.
 * Distributed under the terms of the MIT License.
 */

#ifndef _K_PPP_LAYER__H
#define _K_PPP_LAYER__H

#include <KPPPDefs.h>

#include <net_buffer.h>

class KPPPLayer {
        protected:
                //!     KPPPLayer must be subclassed
                KPPPLayer(const char *name, ppp_level level, uint32 overhead);

        public:
                virtual ~KPPPLayer();
                
                virtual status_t InitCheck() const;
                
                //!     Layer name.
                const char *Name() const
                        { return fName; }
                /*!     \brief Level of this layer (level is defined in enum: \c ppp_level).
                        
                        This should be \c PPP_PROTOCOL_LEVEL if this layer is not an encapsulator.
                */
                ppp_level Level() const
                        { return fLevel; }
                //!     Length of header that will be prepended to outgoing packets.
                uint32 Overhead() const
                        { return fOverhead; }
                
                //!     Sets the next layer. This will be the target of \c SendToNext().
                void SetNext(KPPPLayer *next)
                        { fNext = next; }
                //!     Next layer in chain.
                KPPPLayer *Next() const
                        { return fNext; }
                
                //!     Brings this layer up.
                virtual bool Up() = 0;
                //!     Brings this layer down.
                virtual bool Down() = 0;
                
                //!     Returns whether this layer is allowed to send packets.
                virtual bool IsAllowedToSend() const = 0;
                
                //!     Send a packet with the given protocol number.
                virtual status_t Send(net_buffer *packet, uint16 protocolNumber) = 0;
                //!     Receive a packet with the given protocol number.
                virtual status_t Receive(net_buffer *packet, uint16 protocolNumber) = 0;
                
                status_t SendToNext(net_buffer *packet, uint16 protocolNumber) const;
                        // send the packet to the next layer
                
                virtual void Pulse();

        protected:
                void SetName(const char *name);

        protected:
                status_t fInitStatus;
                uint32 fOverhead;

        private:
                char *fName;
                ppp_level fLevel;
                
                KPPPLayer *fNext;
};


#endif