xref: /hardware/qcom/gps/loc_api/libloc_api_50001/loc_eng_agps.h

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#ifndef __LOC_ENG_AGPS_H__
#define __LOC_ENG_AGPS_H__

#include <stdbool.h>
#include <ctype.h>
#include <string.h>
#include <arpa/inet.h>
#include <hardware/gps.h>
#include <linked_list.h>
#include <LocApiAdapter.h>

// forward declaration
class AgpsStateMachine;
class Subscriber;

// NIF resource events
typedef enum {
    RSRC_SUBSCRIBE,
    RSRC_UNSUBSCRIBE,
    RSRC_GRANTED,
    RSRC_RELEASED,
    RSRC_DENIED,
    RSRC_STATUS_MAX
} AgpsRsrcStatus;

// information bundle for subscribers
struct Notification {
    // goes to every subscriber
    static const int BROADCAST_ALL;
    // goes to every ACTIVE subscriber
    static const int BROADCAST_ACTIVE;
    // goes to every INACTIVE subscriber
    static const int BROADCAST_INACTIVE;

    // go to a specific subscriber
    const Subscriber* rcver;
    // broadcast
    const int groupID;
    // the new resource status event
    const AgpsRsrcStatus rsrcStatus;
    // should the subscriber be deleted after the notification
    const bool postNotifyDelete;

    // convenient constructor
    inline Notification(const int broadcast,
                        const AgpsRsrcStatus status,
                        const bool deleteAfterwards) :
        rcver(NULL), groupID(broadcast), rsrcStatus(status),
        postNotifyDelete(deleteAfterwards) {}

    // convenient constructor
    inline Notification(const Subscriber* subscriber,
                        const AgpsRsrcStatus status,
                        const bool deleteAfterwards) :
        rcver(subscriber), groupID(-1), rsrcStatus(status),
        postNotifyDelete(deleteAfterwards) {}

    // convenient constructor
    inline Notification(const int broadcast) :
        rcver(NULL), groupID(broadcast), rsrcStatus(RSRC_STATUS_MAX),
        postNotifyDelete(false) {}

    // convenient constructor
    inline Notification(const Subscriber* subscriber) :
        rcver(subscriber), groupID(-1), rsrcStatus(RSRC_STATUS_MAX),
        postNotifyDelete(false) {}
};

class AgpsState {
    // allows AgpsStateMachine to access private data
    // no class members are public.  We don't want
    // anyone but state machine to use state.
    friend class AgpsStateMachine;

    // state transitions are done here.
    // Each state implements its own transitions (of course).
    inline virtual AgpsState* onRsrcEvent(AgpsRsrcStatus event, void* data) = 0;

protected:
    // handle back to state machine
    const AgpsStateMachine* mStateMachine;
    // each state has pointers to all 3 states
    // one of which is to itself.
    AgpsState* mReleasedState;
    AgpsState* mAcquiredState;
    AgpsState* mPendingState;
    AgpsState* mReleasingState;

    inline AgpsState(const AgpsStateMachine *stateMachine) :
        mStateMachine(stateMachine),
        mReleasedState(NULL),
        mAcquiredState(NULL),
        mPendingState(NULL),
        mReleasingState(NULL) {}
    virtual ~AgpsState() {}

public:
    // for logging purpose
    inline virtual char* whoami() = 0;
};

class AgpsStateMachine {
    // allows AgpsState to access private data
    // each state is really internal data to the
    // state machine, so it should be able to
    // access anything within the state machine.
    friend class AgpsState;

    // handle to whoever provides the service
    void (* const mServicer)(AGpsStatus* status);
    // NIF type: AGNSS or INTERNET.
    const AGpsType mType;
    // pointer to the current state.
    AgpsState* mStatePtr;
    // a linked list of subscribers.
    void* mSubscribers;
    // apn to the NIF.  Each state machine tracks
    // resource state of a particular NIF.  For each
    // NIF, there is also an active APN.
    char* mAPN;
    // for convenience, we don't do strlen each time.
    unsigned int mAPNLen;
#ifdef QCOM_FEATURE_IPV6
    // bear
    AGpsBearerType mBearer;
#endif
    // ipv4 address for routing

public:
    AgpsStateMachine(void (*servicer)(AGpsStatus* status), AGpsType type);
    virtual ~AgpsStateMachine();

    // self explanatory methods below
    void setAPN(const char* apn, unsigned int len);
    inline const char* getAPN() const { return (const char*)mAPN; }
#ifdef QCOM_FEATURE_IPV6
    inline void setBearer(AGpsBearerType bearer) { mBearer = bearer; }
    inline AGpsBearerType getBearer() const { return mBearer; }
#endif
    inline AGpsType getType() const { return (AGpsType)mType; }

    // someone, a ATL client or BIT, is asking for NIF
    void subscribeRsrc(Subscriber *subscriber);

    // someone, a ATL client or BIT, is done with NIF
    bool unsubscribeRsrc(Subscriber *subscriber);

    // add a subscriber in the linked list, if not already there.
    void addSubscriber(Subscriber* subscriber) const;

    void onRsrcEvent(AgpsRsrcStatus event);

    // put the data together and send the FW
    void sendRsrcRequest(AGpsStatusValue action) const;

    inline bool hasSubscribers() const
    { return !linked_list_empty(mSubscribers); }

    bool hasActiveSubscribers() const;

    inline void dropAllSubscribers() const
    { linked_list_flush(mSubscribers); }

    // private. Only a state gets to call this.
    void notifySubscribers(Notification& notification) const;
};

// each subscriber is a AGPS client.  In the case of ATL, there could be
// multiple clients from modem.  In the case of BIT, there is only one
// cilent from BIT daemon.
struct Subscriber {
    const int ID;
    const AgpsStateMachine* mStateMachine;
    inline Subscriber(const int id,
                      const AgpsStateMachine* stateMachine) :
        ID(id), mStateMachine(stateMachine) {}
    inline virtual ~Subscriber() {}

    virtual void setIPAddresses(int &v4, char* v6) = 0;

    inline virtual bool equals(const Subscriber *s) const
    { return ID == s->ID; }

    // notifies a subscriber a new NIF resource status, usually
    // either GRANTE, DENIED, or RELEASED
    virtual bool notifyRsrcStatus(Notification &notification) = 0;

    virtual bool waitForCloseComplete() { return false; }
    virtual void setInactive() {}
    virtual bool isInactive() { return false; }

    virtual Subscriber* clone() = 0;
    // checks if this notification is for me, i.e.
    // either has my id, or has a broadcast id.
    bool forMe(Notification &notification);
};

// BITSubscriber, created with requests from BIT daemon
struct BITSubscriber : public Subscriber {
    inline BITSubscriber(const AgpsStateMachine* stateMachine,
                         unsigned int ipv4, char* ipv6) :
        Subscriber(ipv4, stateMachine)
    {
        if (NULL == ipv6) {
            ipv6Addr[0] = NULL;
        } else {
            memcpy(ipv6Addr, ipv6, sizeof(ipv6Addr));
        }
    }

    virtual bool notifyRsrcStatus(Notification &notification);

    inline virtual void setIPAddresses(int &v4, char* v6)
    { v4 = ID; memcpy(v6, ipv6Addr, sizeof(ipv6Addr)); }

    virtual Subscriber* clone()
    {
        return new BITSubscriber(mStateMachine, ID, ipv6Addr);
    }

    virtual bool equals(const Subscriber *s) const;

private:
    char ipv6Addr[16];
};

// ATLSubscriber, created with requests from ATL
struct ATLSubscriber : public Subscriber {
    const LocApiAdapter* mLocAdapter;
    inline ATLSubscriber(const int id,
                         const AgpsStateMachine* stateMachine,
                         const LocApiAdapter* adapter) :
        Subscriber(id, stateMachine), mLocAdapter(adapter) {}
    virtual bool notifyRsrcStatus(Notification &notification);

    inline virtual void setIPAddresses(int &v4, char* v6)
    { v4 = INADDR_NONE; v6[0] = 0; }

    inline virtual Subscriber* clone()
    {
        return new ATLSubscriber(ID, mStateMachine, mLocAdapter);
    }
};

#endif //__LOC_ENG_AGPS_H__