link.h

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/*
 * This file is part of plptools.
 *
 *  Copyright (C) 1999 Philip Proudman <philip.proudman@btinternet.com>
 *  Copyright (C) 1999-2002 Fritz Elfert <felfert@to.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  along with this program; if not, see <https://www.gnu.org/licenses/>.
 *
 */
#pragma once
 
#include "config.h"
#include <pthread.h>
#include <sys/time.h>
 
#include "bufferstore.h"
#include "bufferarray.h"
#include "Enum.h"
#include <vector>
 
class DataLink;
class NCP;
 
typedef struct {
    int seq;
    int txcount;
    struct timeval stamp;
    BufferStore data;
} AckWaitQueueElement;
 
extern "C" {
    static void *expire_check(void *);
}
 
class Link {
public:
 
    enum link_type {
        LINK_TYPE_UNKNOWN = 0,
        LINK_TYPE_SIBO    = 1,
        LINK_TYPE_EPOC    = 2,
    };
 
    Link(const char *fname, int baud, NCP *ncp, bool noDSRCheck, unsigned short verbose, const int cancellationFd);
 
    ~Link();
 
    void send(const BufferStore &buff);
 
    bool stuffToSend();
 
    bool hasFailed();
 
    void reset();
 
    void purgeQueue(int channel);
 
    Enum<link_type> getLinkType();
 
    int getSpeed();
 
private:
    friend class DataLink;
    friend void * expire_check(void *);
 
    void receive(BufferStore buf);
    void transmit(BufferStore buf);
    void sendAck(int seq, Enum<link_type> linkType);
    void sendReqReq();
    void sendReqCon();
    void sendReq(Enum<link_type> linkType);
    void multiAck(struct timeval);
    void retransmit();
    void transmitHoldQueue(int channel);
    void transmitWaitQueue();
    void purgeAllQueues();
    unsigned long retransTimeout();
 
    pthread_t checkThreadId_;
    pthread_mutex_t queueMutex_;
 
    NCP * const ncp_;
    DataLink *dataLink_ = nullptr;
    int txSequence_ = 1;
    int rxSequence_ = -1;
    int seqMask_ = 7;
    int maxOutstanding_ = 1;
    unsigned long conMagic_;
    const unsigned short verbose_;
    bool failed_;
    Enum<link_type> linkType_;
 
    std::vector<AckWaitQueueElement> ackWaitQueue;
    std::vector<BufferStore> holdQueue_;
    std::vector<BufferStore> waitQueue_;
    bool xoff_[256];
 
    const int cancellationFd_;
};