inet::ieee80211::Ieee80211MgmtAP Class Reference

Used in 802.11 infrastructure mode: handles management frames for an access point (AP). More...

#include <Ieee80211MgmtAP.h>

Inheritance diagram for inet::ieee80211::Ieee80211MgmtAP:

Classes
struct	MAC_compare
class	NotificationInfoSta
struct	STAInfo
	Describes a STA. More...

Public Types
enum	STAStatus { NOT_AUTHENTICATED, AUTHENTICATED, ASSOCIATED }
	State of a STA. More...
typedef std::map< MACAddress, STAInfo, MAC_compare >	STAList
Public Types inherited from inet::ieee80211::Ieee80211MgmtAPBase
enum	EncapDecap { ENCAP_DECAP_TRUE = 1, ENCAP_DECAP_FALSE, ENCAP_DECAP_ETH }

Public Member Functions
	Ieee80211MgmtAP ()
virtual	~Ieee80211MgmtAP ()
Public Member Functions inherited from inet::ieee80211::Ieee80211MgmtBase
virtual bool	handleOperationStage (LifecycleOperation *operation, int stage, IDoneCallback *doneCallback) override
	Perform one stage of a lifecycle operation. More...
Public Member Functions inherited from inet::ILifecycle
virtual	~ILifecycle ()

Protected Member Functions
virtual int	numInitStages () const override
virtual void	initialize (int) override
virtual void	handleTimer (cMessage *msg) override
	Implements abstract Ieee80211MgmtBase method. More...
virtual void	handleUpperMessage (cPacket *msg) override
	Implements abstract Ieee80211MgmtBase method. More...
virtual void	handleCommand (int msgkind, cObject *ctrl) override
	Implements abstract Ieee80211MgmtBase method – throws an error (no commands supported) More...
virtual void	receiveSignal (cComponent *source, simsignal_t signalID, long value, cObject *details) override
	Called by the signal handler whenever a change occurs we're interested in. More...
virtual STAInfo *	lookupSenderSTA (Ieee80211ManagementFrame *frame)
	Utility function: return sender STA's entry from our STA list, or nullptr if not in there. More...
virtual void	sendManagementFrame (Ieee80211ManagementFrame *frame, const MACAddress &destAddr)
	Utility function: set fields in the given frame and send it out to the address. More...
virtual void	sendBeacon ()
	Utility function: creates and sends a beacon frame. More...
void	sendAssocNotification (const MACAddress &addr)
void	sendDisAssocNotification (const MACAddress &addr)
Processing of different frame types
virtual void	handleDataFrame (Ieee80211DataFrame *frame) override
virtual void	handleAuthenticationFrame (Ieee80211AuthenticationFrame *frame) override
virtual void	handleDeauthenticationFrame (Ieee80211DeauthenticationFrame *frame) override
virtual void	handleAssociationRequestFrame (Ieee80211AssociationRequestFrame *frame) override
virtual void	handleAssociationResponseFrame (Ieee80211AssociationResponseFrame *frame) override
virtual void	handleReassociationRequestFrame (Ieee80211ReassociationRequestFrame *frame) override
virtual void	handleReassociationResponseFrame (Ieee80211ReassociationResponseFrame *frame) override
virtual void	handleDisassociationFrame (Ieee80211DisassociationFrame *frame) override
virtual void	handleBeaconFrame (Ieee80211BeaconFrame *frame) override
virtual void	handleProbeRequestFrame (Ieee80211ProbeRequestFrame *frame) override
virtual void	handleProbeResponseFrame (Ieee80211ProbeResponseFrame *frame) override
virtual void	start () override
	lifecycle support More...
virtual void	stop () override
Protected Member Functions inherited from inet::ieee80211::Ieee80211MgmtAPBase
virtual void	distributeReceivedDataFrame (Ieee80211DataFrame *frame)
	Utility function for APs: sends back a data frame we received from a STA to the wireless LAN, after tweaking fromDS/toDS bits and shuffling addresses as needed. More...
virtual Ieee80211DataFrame *	encapsulate (cPacket *msg)
	Utility function for handleUpperMessage() More...
virtual Ieee80211DataFrame *	convertFromEtherFrame (EtherFrame *ethframe)
	Utility function: converts EtherFrame to Ieee80211Frame. More...
virtual EtherFrame *	convertToEtherFrame (Ieee80211DataFrame *frame)
	Utility function: converts Ieee80211Frame to EtherFrame. More...
virtual void	sendToUpperLayer (Ieee80211DataFrame *frame)
	Utility function: send a frame to upperLayerOut. More...
Protected Member Functions inherited from inet::ieee80211::Ieee80211MgmtBase
virtual void	handleMessage (cMessage *msg) override
	Dispatches incoming messages to handleTimer(), handleUpperMessage() or processFrame(). More...
virtual void	sendDown (cPacket *frame)
	Utility method for implementing handleUpperMessage(): send message to MAC. More...
virtual void	dropManagementFrame (Ieee80211ManagementFrame *frame)
	Utility method to dispose of an unhandled frame. More...
virtual void	sendUp (cMessage *msg)
	Utility method: sends the packet to the upper layer. More...
virtual void	processFrame (Ieee80211DataOrMgmtFrame *frame)
	Dispatch to frame processing methods according to frame type. More...

Protected Attributes
std::string	ssid
int	channelNumber = -1
simtime_t	beaconInterval
int	numAuthSteps = 0
Ieee80211SupportedRatesElement	supportedRates
STAList	staList
	list of STAs More...
cMessage *	beaconTimer = nullptr
Protected Attributes inherited from inet::ieee80211::Ieee80211MgmtAPBase
bool	isConnectedToHL
EncapDecap	encapDecap
Protected Attributes inherited from inet::ieee80211::Ieee80211MgmtBase
MACAddress	myAddress
bool	isOperational
long	numDataFramesReceived
long	numMgmtFramesReceived
long	numMgmtFramesDropped

Detailed Description

Used in 802.11 infrastructure mode: handles management frames for an access point (AP).

See corresponding NED file for a detailed description.

Author

Andras Varga

Member Typedef Documentation

typedef std::map<MACAddress, STAInfo, MAC_compare> inet::ieee80211::Ieee80211MgmtAP::STAList

Member Enumeration Documentation

enum inet::ieee80211::Ieee80211MgmtAP::STAStatus

State of a STA.

Enumerator
NOT_AUTHENTICATED
AUTHENTICATED
ASSOCIATED

{ NOT_AUTHENTICATED, AUTHENTICATED, ASSOCIATED };

Constructor & Destructor Documentation

inet::ieee80211::Ieee80211MgmtAP::Ieee80211MgmtAP ( )

inline

{}

inet::ieee80211::Ieee80211MgmtAP::~Ieee80211MgmtAP ( )

virtual

{
    cancelAndDelete(beaconTimer);
}

Member Function Documentation

void inet::ieee80211::Ieee80211MgmtAP::handleAssociationRequestFrame ( Ieee80211AssociationRequestFrame *  frame )

overrideprotectedvirtual

Implements inet::ieee80211::Ieee80211MgmtBase.

{
    EV << "Processing AssociationRequest frame\n";

    // "11.3.2 AP association procedures"
    STAInfo *sta = lookupSenderSTA(frame);
    if (!sta || sta->status == NOT_AUTHENTICATED) {
        // STA not authenticated: send error and return
        Ieee80211DeauthenticationFrame *resp = new Ieee80211DeauthenticationFrame("Deauth");
        resp->getBody().setReasonCode(RC_NONAUTH_ASS_REQUEST);
        sendManagementFrame(resp, frame->getTransmitterAddress());
        delete frame;
        return;
    }

    delete frame;

    // mark STA as associated
    if (sta->status != ASSOCIATED)
        sendAssocNotification(sta->address);
    sta->status = ASSOCIATED;    // XXX this should only take place when MAC receives the ACK for the response

    // send OK response
    Ieee80211AssociationResponseFrame *resp = new Ieee80211AssociationResponseFrame("AssocResp-OK");
    Ieee80211AssociationResponseFrameBody& body = resp->getBody();
    body.setStatusCode(SC_SUCCESSFUL);
    body.setAid(0);    //XXX
    body.setSupportedRates(supportedRates);
    sendManagementFrame(resp, sta->address);
}

void inet::ieee80211::Ieee80211MgmtAP::handleAssociationResponseFrame ( Ieee80211AssociationResponseFrame *  frame )

overrideprotectedvirtual

Implements inet::ieee80211::Ieee80211MgmtBase.

{
    dropManagementFrame(frame);
}

void inet::ieee80211::Ieee80211MgmtAP::handleAuthenticationFrame ( Ieee80211AuthenticationFrame *  frame )

overrideprotectedvirtual

Implements inet::ieee80211::Ieee80211MgmtBase.

{
    int frameAuthSeq = frame->getBody().getSequenceNumber();
    EV << "Processing Authentication frame, seqNum=" << frameAuthSeq << "\n";

    // create STA entry if needed
    STAInfo *sta = lookupSenderSTA(frame);
    if (!sta) {
        MACAddress staAddress = frame->getTransmitterAddress();
        sta = &staList[staAddress];    // this implicitly creates a new entry
        sta->address = staAddress;
        sta->status = NOT_AUTHENTICATED;
        sta->authSeqExpected = 1;
    }

    // reset authentication status, when starting a new auth sequence
    // The statements below are added because the L2 handover time was greater than before when
    // a STA wants to re-connect to an AP with which it was associated before. When the STA wants to
    // associate again with the previous AP, then since the AP is already having an entry of the STA
    // because of old association, and thus it is expecting an authentication frame number 3 but it
    // receives authentication frame number 1 from STA, which will cause the AP to return an Auth-Error
    // making the MN STA to start the handover process all over again.
    if (frameAuthSeq == 1) {
        if (sta->status == ASSOCIATED)
            sendDisAssocNotification(sta->address);
        sta->status = NOT_AUTHENTICATED;
        sta->authSeqExpected = 1;
    }

    // check authentication sequence number is OK
    if (frameAuthSeq != sta->authSeqExpected) {
        // wrong sequence number: send error and return
        EV << "Wrong sequence number, " << sta->authSeqExpected << " expected\n";
        Ieee80211AuthenticationFrame *resp = new Ieee80211AuthenticationFrame("Auth-ERROR");
        resp->getBody().setStatusCode(SC_AUTH_OUT_OF_SEQ);
        sendManagementFrame(resp, frame->getTransmitterAddress());
        delete frame;
        sta->authSeqExpected = 1;    // go back to start square
        return;
    }

    // station is authenticated if it made it through the required number of steps
    bool isLast = (frameAuthSeq + 1 == numAuthSteps);

    // send OK response (we don't model the cryptography part, just assume
    // successful authentication every time)
    EV << "Sending Authentication frame, seqNum=" << (frameAuthSeq + 1) << "\n";
    Ieee80211AuthenticationFrame *resp = new Ieee80211AuthenticationFrame(isLast ? "Auth-OK" : "Auth");
    resp->getBody().setSequenceNumber(frameAuthSeq + 1);
    resp->getBody().setStatusCode(SC_SUCCESSFUL);
    resp->getBody().setIsLast(isLast);
    // XXX frame length could be increased to account for challenge text length etc.
    sendManagementFrame(resp, frame->getTransmitterAddress());

    delete frame;

    // update status
    if (isLast) {
        if (sta->status == ASSOCIATED)
            sendDisAssocNotification(sta->address);
        sta->status = AUTHENTICATED;    // XXX only when ACK of this frame arrives
        EV << "STA authenticated\n";
    }
    else {
        sta->authSeqExpected += 2;
        EV << "Expecting Authentication frame " << sta->authSeqExpected << "\n";
    }
}

void inet::ieee80211::Ieee80211MgmtAP::handleBeaconFrame ( Ieee80211BeaconFrame *  frame )

overrideprotectedvirtual

Implements inet::ieee80211::Ieee80211MgmtBase.

{
    dropManagementFrame(frame);
}

void inet::ieee80211::Ieee80211MgmtAP::handleCommand ( int  msgkind, cObject *  ctrl  )

overrideprotectedvirtual

Implements abstract Ieee80211MgmtBase method – throws an error (no commands supported)

Implements inet::ieee80211::Ieee80211MgmtBase.

{
    throw cRuntimeError("handleCommand(): no commands supported");
}

void inet::ieee80211::Ieee80211MgmtAP::handleDataFrame ( Ieee80211DataFrame *  frame )

overrideprotectedvirtual

Implements inet::ieee80211::Ieee80211MgmtBase.

{
    // check toDS bit
    if (!frame->getToDS()) {
        // looks like this is not for us - discard
        EV << "Frame is not for us (toDS=false) -- discarding\n";
        delete frame;
        return;
    }

    // handle broadcast/multicast frames
    if (frame->getAddress3().isMulticast()) {
        EV << "Handling multicast frame\n";

        if (isConnectedToHL)
            sendToUpperLayer(frame->dup());

        distributeReceivedDataFrame(frame);
        return;
    }

    // look up destination address in our STA list
    auto it = staList.find(frame->getAddress3());
    if (it == staList.end()) {
        // not our STA -- pass up frame to relayUnit for LAN bridging if we have one
        if (isConnectedToHL) {
            sendToUpperLayer(frame);
        }
        else {
            EV << "Frame's destination address is not in our STA list -- dropping frame\n";
            delete frame;
        }
    }
    else {
        // dest address is our STA, but is it already associated?
        if (it->second.status == ASSOCIATED)
            distributeReceivedDataFrame(frame); // send it out to the destination STA
        else {
            EV << "Frame's destination STA is not in associated state -- dropping frame\n";
            delete frame;
        }
    }
}

void inet::ieee80211::Ieee80211MgmtAP::handleDeauthenticationFrame ( Ieee80211DeauthenticationFrame *  frame )

overrideprotectedvirtual

Implements inet::ieee80211::Ieee80211MgmtBase.

{
    EV << "Processing Deauthentication frame\n";

    STAInfo *sta = lookupSenderSTA(frame);
    delete frame;

    if (sta) {
        // mark STA as not authenticated; alternatively, it could also be removed from staList
        if (sta->status == ASSOCIATED)
            sendDisAssocNotification(sta->address);
        sta->status = NOT_AUTHENTICATED;
        sta->authSeqExpected = 1;
    }
}

void inet::ieee80211::Ieee80211MgmtAP::handleDisassociationFrame ( Ieee80211DisassociationFrame *  frame )

overrideprotectedvirtual

Implements inet::ieee80211::Ieee80211MgmtBase.

{
    STAInfo *sta = lookupSenderSTA(frame);
    delete frame;

    if (sta) {
        if (sta->status == ASSOCIATED)
            sendDisAssocNotification(sta->address);
        sta->status = AUTHENTICATED;
    }
}

void inet::ieee80211::Ieee80211MgmtAP::handleProbeRequestFrame ( Ieee80211ProbeRequestFrame *  frame )

overrideprotectedvirtual

Implements inet::ieee80211::Ieee80211MgmtBase.

{
    EV << "Processing ProbeRequest frame\n";

    if (strcmp(frame->getBody().getSSID(), "") != 0 && strcmp(frame->getBody().getSSID(), ssid.c_str()) != 0) {
        EV << "SSID `" << frame->getBody().getSSID() << "' does not match, ignoring frame\n";
        dropManagementFrame(frame);
        return;
    }

    MACAddress staAddress = frame->getTransmitterAddress();
    delete frame;

    EV << "Sending ProbeResponse frame\n";
    Ieee80211ProbeResponseFrame *resp = new Ieee80211ProbeResponseFrame("ProbeResp");
    Ieee80211ProbeResponseFrameBody& body = resp->getBody();
    body.setSSID(ssid.c_str());
    body.setSupportedRates(supportedRates);
    body.setBeaconInterval(beaconInterval);
    body.setChannelNumber(channelNumber);
    sendManagementFrame(resp, staAddress);
}

void inet::ieee80211::Ieee80211MgmtAP::handleProbeResponseFrame ( Ieee80211ProbeResponseFrame *  frame )

overrideprotectedvirtual

Implements inet::ieee80211::Ieee80211MgmtBase.

{
    dropManagementFrame(frame);
}

void inet::ieee80211::Ieee80211MgmtAP::handleReassociationRequestFrame ( Ieee80211ReassociationRequestFrame *  frame )

overrideprotectedvirtual

Implements inet::ieee80211::Ieee80211MgmtBase.

{
    EV << "Processing ReassociationRequest frame\n";

    // "11.3.4 AP reassociation procedures" -- almost the same as AssociationRequest processing
    STAInfo *sta = lookupSenderSTA(frame);
    if (!sta || sta->status == NOT_AUTHENTICATED) {
        // STA not authenticated: send error and return
        Ieee80211DeauthenticationFrame *resp = new Ieee80211DeauthenticationFrame("Deauth");
        resp->getBody().setReasonCode(RC_NONAUTH_ASS_REQUEST);
        sendManagementFrame(resp, frame->getTransmitterAddress());
        delete frame;
        return;
    }

    delete frame;

    // mark STA as associated
    sta->status = ASSOCIATED;    // XXX this should only take place when MAC receives the ACK for the response

    // send OK response
    Ieee80211ReassociationResponseFrame *resp = new Ieee80211ReassociationResponseFrame("ReassocResp-OK");
    Ieee80211ReassociationResponseFrameBody& body = resp->getBody();
    body.setStatusCode(SC_SUCCESSFUL);
    body.setAid(0);    //XXX
    body.setSupportedRates(supportedRates);
    sendManagementFrame(resp, sta->address);
}

void inet::ieee80211::Ieee80211MgmtAP::handleReassociationResponseFrame ( Ieee80211ReassociationResponseFrame *  frame )

overrideprotectedvirtual

Implements inet::ieee80211::Ieee80211MgmtBase.

{
    dropManagementFrame(frame);
}

void inet::ieee80211::Ieee80211MgmtAP::handleTimer ( cMessage *  msg )

overrideprotectedvirtual

Implements abstract Ieee80211MgmtBase method.

Implements inet::ieee80211::Ieee80211MgmtBase.

{
    if (msg == beaconTimer) {
        sendBeacon();
        scheduleAt(simTime() + beaconInterval, beaconTimer);
    }
    else {
        throw cRuntimeError("internal error: unrecognized timer '%s'", msg->getName());
    }
}

void inet::ieee80211::Ieee80211MgmtAP::handleUpperMessage ( cPacket *  msg )

overrideprotectedvirtual

Implements abstract Ieee80211MgmtBase method.

Implements inet::ieee80211::Ieee80211MgmtBase.

{
    Ieee80211DataFrame *frame = encapsulate(msg);
    MACAddress macAddr = frame->getReceiverAddress();
    if (!macAddr.isMulticast()) {
        auto it = staList.find(macAddr);
        if (it == staList.end() || it->second.status != ASSOCIATED) {
            EV << "STA with MAC address " << macAddr << " not associated with this AP, dropping frame\n";
            delete frame;    // XXX count drops?
            return;
        }
    }

    sendDown(frame);
}

void inet::ieee80211::Ieee80211MgmtAP::initialize ( int  stage )

overrideprotectedvirtual

Reimplemented from inet::ieee80211::Ieee80211MgmtAPBase.

{
    Ieee80211MgmtAPBase::initialize(stage);

    if (stage == INITSTAGE_LOCAL) {
        // read params and init vars
        ssid = par("ssid").stringValue();
        beaconInterval = par("beaconInterval");
        numAuthSteps = par("numAuthSteps");
        if (numAuthSteps != 2 && numAuthSteps != 4)
            throw cRuntimeError("parameter 'numAuthSteps' (number of frames exchanged during authentication) must be 2 or 4, not %d", numAuthSteps);
        channelNumber = -1;    // value will arrive from physical layer in receiveChangeNotification()
        WATCH(ssid);
        WATCH(channelNumber);
        WATCH(beaconInterval);
        WATCH(numAuthSteps);
        WATCH_MAP(staList);

        //TBD fill in supportedRates

        // subscribe for notifications
        cModule *radioModule = getModuleFromPar<cModule>(par("radioModule"), this);
        radioModule->subscribe(Ieee80211Radio::radioChannelChangedSignal, this);

        // start beacon timer (randomize startup time)
        beaconTimer = new cMessage("beaconTimer");
    }
    else if (stage == INITSTAGE_LINK_LAYER) {
        if (isOperational)
            scheduleAt(simTime() + uniform(0, beaconInterval), beaconTimer);
    }
}

Ieee80211MgmtAP::STAInfo * inet::ieee80211::Ieee80211MgmtAP::lookupSenderSTA ( Ieee80211ManagementFrame *  frame )

protectedvirtual

Utility function: return sender STA's entry from our STA list, or nullptr if not in there.

{
    auto it = staList.find(frame->getTransmitterAddress());
    return it == staList.end() ? nullptr : &(it->second);
}

virtual int inet::ieee80211::Ieee80211MgmtAP::numInitStages ( ) const

inlineoverrideprotectedvirtual

Reimplemented from inet::ieee80211::Ieee80211MgmtAPBase.

{ return NUM_INIT_STAGES; }

void inet::ieee80211::Ieee80211MgmtAP::receiveSignal ( cComponent *  source, simsignal_t  signalID, long  value, cObject *  details  )

overrideprotectedvirtual

Called by the signal handler whenever a change occurs we're interested in.

{
    Enter_Method_Silent();
    if (signalID == Ieee80211Radio::radioChannelChangedSignal) {
        EV << "updating channel number\n";
        channelNumber = value;
    }
}

void inet::ieee80211::Ieee80211MgmtAP::sendAssocNotification ( const MACAddress &  addr )

protected

{
    NotificationInfoSta notif;
    notif.setApAddress(myAddress);
    notif.setStaAddress(addr);
    emit(NF_L2_AP_ASSOCIATED, &notif);
}

void inet::ieee80211::Ieee80211MgmtAP::sendBeacon ( )

protectedvirtual

Utility function: creates and sends a beacon frame.

{
    EV << "Sending beacon\n";
    Ieee80211BeaconFrame *frame = new Ieee80211BeaconFrame("Beacon");
    Ieee80211BeaconFrameBody& body = frame->getBody();
    body.setSSID(ssid.c_str());
    body.setSupportedRates(supportedRates);
    body.setBeaconInterval(beaconInterval);
    body.setChannelNumber(channelNumber);
    body.setBodyLength(8 + 2 + 2 + (2 + ssid.length()) + (2 + supportedRates.numRates));

    frame->setByteLength(28 + body.getBodyLength());
    frame->setReceiverAddress(MACAddress::BROADCAST_ADDRESS);
    frame->setFromDS(true);

    sendDown(frame);
}

void inet::ieee80211::Ieee80211MgmtAP::sendDisAssocNotification ( const MACAddress &  addr )

protected

{
    NotificationInfoSta notif;
    notif.setApAddress(myAddress);
    notif.setStaAddress(addr);
    emit(NF_L2_AP_DISASSOCIATED, &notif);
}

void inet::ieee80211::Ieee80211MgmtAP::sendManagementFrame ( Ieee80211ManagementFrame *  frame, const MACAddress &  destAddr  )

protectedvirtual

Utility function: set fields in the given frame and send it out to the address.

{
    frame->setFromDS(true);
    frame->setReceiverAddress(destAddr);
    frame->setAddress3(myAddress);
    sendDown(frame);
}

void inet::ieee80211::Ieee80211MgmtAP::start ( )

overrideprotectedvirtual

lifecycle support

Reimplemented from inet::ieee80211::Ieee80211MgmtBase.

{
    Ieee80211MgmtAPBase::start();
    scheduleAt(simTime() + uniform(0, beaconInterval), beaconTimer);
}

void inet::ieee80211::Ieee80211MgmtAP::stop ( )

overrideprotectedvirtual

Reimplemented from inet::ieee80211::Ieee80211MgmtBase.

{
    cancelEvent(beaconTimer);
    staList.clear();
    Ieee80211MgmtAPBase::stop();
}

Member Data Documentation

simtime_t inet::ieee80211::Ieee80211MgmtAP::beaconInterval

protected

cMessage* inet::ieee80211::Ieee80211MgmtAP::beaconTimer = nullptr

protected

int inet::ieee80211::Ieee80211MgmtAP::channelNumber = -1

protected

int inet::ieee80211::Ieee80211MgmtAP::numAuthSteps = 0

protected

std::string inet::ieee80211::Ieee80211MgmtAP::ssid

protected

STAList inet::ieee80211::Ieee80211MgmtAP::staList

protected

list of STAs

Ieee80211SupportedRatesElement inet::ieee80211::Ieee80211MgmtAP::supportedRates

protected

---

The documentation for this class was generated from the following files:

• Ieee80211MgmtAP.h
• Ieee80211MgmtAP.cc