if_wlp_wavelan_roam.c

WaveLAN无线网卡Linux驱动程序

		else {
			if (sc->sc_rs.rs_apreg) {
#ifdef WLP_DEBUG
				printf("Aborting Registration!\n");
#endif
				SendRECReq(a->ap_softc);	/* XXX */
			}
			sc->sc_rs.rs_apreg = a;

			/* NWID Promisc Mode */
			SetNWID(sc, a->ap_beacon.snwid, 1);

			SendSOReq(sc, a);	/* Send a Sign-on Request */
			sc->sc_rs.rs_roam_mode = MODE_REG_CELL;
		}

		break;		/* switch() */

	case MODE_STOP_CELL:

		if (sc->sc_rs.rs_ap == 0)
			panic("Stop Cell Search Mode && ap == 0");
		if (sc->sc_rs.rs_apreg)
			panic("Stop Cell Search Mode && apreq != 0");

		if (SNR(sc->sc_rs.rs_ap) > REG_CELL(sc->sc_rs.rs_ap)) {
			goto done;
		} else if (SNR(sc->sc_rs.rs_ap) < FAST_CELL(sc->sc_rs.rs_ap)) {
			sc->sc_rs.rs_roam_mode = MODE_FAST_CELL;
			goto start;
		} else {
			sc->sc_rs.rs_roam_mode = MODE_REG_CELL;
			goto start;
		}

		break;

	default:
		panic("roam_timer(): RoamMode is invalid");
	}

done:

	timeout(roam_timer, (void *) sc, 2 * hz);	/* 2 seconds */

quit:

	splx(s);
}


static void
PurgeAccessPointList(sc)
	struct wlp_softc *sc;
{
	struct accesspoint *a, *an;

	for (a = sc->sc_rs.rs_aplist.lh_first; a;) {
		an = a->ap_link.le_next;

		if (AP_EXPIRED(a)) {
#ifdef WLP_DEBUG
			printf("NWID: %x expired at %ld.%ld\n",
			       a->ap_beacon.snwid,
			       a->ap_expire.tv_sec, a->ap_expire.tv_usec);
#endif
			if (a == sc->sc_rs.rs_ap) {
				sc->sc_rs.rs_ap = 0;
				sc->sc_rs.rs_roam_mode = MODE_FAST_CELL;
			}
			if (a == sc->sc_rs.rs_apreg) {
				SendRECReq(sc);	/* XXX */
				sc->sc_rs.rs_apreg = 0;
				sc->sc_rs.rs_roam_mode = MODE_FAST_CELL;
				sc->sc_rs.rs_SOReqRetrans = 0;
			}
			LIST_REMOVE(a, ap_link);
			free(a, M_TEMP);
		}
		a = an;
	}
}


struct accesspoint *
BestAccessPoint1(sc)
	struct wlp_softc *sc;
{
	struct accesspoint *a;
	struct accesspoint *maxa = 0;
	int             maxsnr = -1;

	for (a = sc->sc_rs.rs_aplist.lh_first; a; a = a->ap_link.le_next) {
		if (maxsnr < 0) {
			maxsnr = SNR(a);
			maxa = a;
		} else if (SNR(a) > maxsnr) {
			maxsnr = SNR(a);
			maxa = a;
		}
	}
#ifdef WLP_DEBUG
      if(maxa == 0)
              printf("%s: no Access Point found...\n", __FUNCTION__);
#endif
	return maxa;
}



static struct accesspoint *
BestAccessPoint2(X, Y)
	struct accesspoint *X;
	struct accesspoint *Y;
{
	int             x = 0;
	int             y = 0;

	if (Y == 0)
		return X;	/* X has prescedence */
	if (X == 0)
		return Y;

	if (SNR(X) < FAST_CELL(X))
		x = 1;
	else if (SNR(X) < REG_CELL(X))
		x = 2;
	else if (SNR(X) < STOP_CELL(X))
		x = 3;
	else
		x = 4;

	if (SNR(Y) < FAST_CELL(Y))
		y = 1;
	else if (SNR(Y) < REG_CELL(Y))
		y = 2;
	else if (SNR(Y) < STOP_CELL(Y))
		y = 3;
	else
		y = 4;

	return (x >= y ? X : Y);
}


/*
 * ======================================================================
 * Packet Processing Functions
 * ======================================================================
 */
static void
ProcessBeacon(eh, m, sigstat)
	struct ether_header *eh;
	struct mbuf    *m;
	int             sigstat;
{
	struct arpcom  *ac = (struct arpcom *) m->m_pkthdr.rcvif;
	struct wlp_softc *sc;
	struct pkt_beacon *p;
	struct accesspoint *a;

	if (ac == 0)
		panic("ProcessBeacon(): ac = 0");

	sc = (struct wlp_softc *) ac->ac_if.if_softc;
	p = mtod(m, struct pkt_beacon *);

	sc->sc_rs.rs_BeaconCount++;

	if (sc->sc_rs.rs_domid && sc->sc_rs.rs_domid != ntohs(p->domid)) {
		return;
	}
	p->snwid ^= htons(sc->sc_rs.rs_beaconkey);

	for (a = sc->sc_rs.rs_aplist.lh_first; a; a = a->ap_link.le_next) {
		if (a->ap_beacon.snwid == ntohs(p->snwid))
			break;
	}

	/*
	 * If this is a beacon from a new access point...
	 */
	if (a == 0) {
		/*
		 * Discard the Beacon if the SNR is < Fast Cell Search
		 * Threshold
		 */
		if ((min((sigstat >> 16) & 0xFF, 36) -
		     min((sigstat >> 8) & 0xFF, 36)) < p->fcell) {
			return;
		}
		a = (struct accesspoint *)
			malloc(sizeof(*a), M_TEMP, M_DONTWAIT);
		if (!a) return;
		bzero(a, sizeof(*a));

		a->ap_beacon.pdutype = p->pdutype;
		/* a->ap_beacon.sequence = p->sequence; */
		a->ap_beacon.domid = ntohs(p->domid);
		a->ap_beacon.snwid = ntohs(p->snwid);
		/* a->ap_beacon.rfnoise = p->rfnoise; */
		a->ap_beacon.threshold = p->threshold;
		a->ap_beacon.scell = p->scell;
		a->ap_beacon.rcell = p->rcell;
		a->ap_beacon.fcell = p->fcell;
		*((u_int16_t *) & a->ap_beacon.interval)
			= ntohs(*((u_int16_t *) & p->interval));
		*((u_int16_t *) & a->ap_beacon.timeout)
			= ntohs(*((u_int16_t *) & p->timeout));
		strncpy(a->ap_beacon.apname, p->apname, sizeof(p->apname));

		/*
		 * Save MAC Address and ifp
		 */
		bcopy(eh->ether_shost, a->ap_macaddr, ETHER_ADDR_LEN);
		a->ap_softc = (struct wlp_softc *)
			((struct ifnet *) m->m_pkthdr.rcvif)->if_softc;

		LIST_INSERT_HEAD(&sc->sc_rs.rs_aplist, a, ap_link);
#ifdef WLP_DEBUG
		printf("%s: added %p to the AP list\n", __FUNCTION__, a);
#endif
	}
	a->ap_beacon.sequence = p->sequence;
	a->ap_beacon.rfnoise = p->rfnoise;

#define sigavg(x, y)	( (x) ? (((x) + (y)) >> 1) : (y) )

	a->ap_siglevel =
		sigavg(a->ap_siglevel, min((sigstat >> 16) & 0xFF, 36));
	a->ap_sillevel =
		sigavg(a->ap_sillevel, min((sigstat >> 8) & 0xFF, 36));
	a->ap_sigqual = sigstat & 0x0F;

	AP_SET_EXPIRE(a);

	sc->sc_rs.rs_BeaconKept++;
}


static void
ProcessSORsp(eh, m)
	struct ether_header *eh;
	struct mbuf    *m;
{
	struct ifnet   *ifp = (struct ifnet *) m->m_pkthdr.rcvif;
	struct wlp_softc *sc;
	struct pkt_sorsp *p;

	if (ifp == 0)
		panic("ProcessSORsp(): ifp = 0");

	sc = (struct wlp_softc *) ifp->if_softc;
	p = mtod(m, struct pkt_sorsp *);

	if (sc->sc_rs.rs_apreg == 0) {
#ifdef WLP_DEBUG
		printf("wlp%d: Received a SIGN-ON Response, but not registering\n",
		       ifp->if_unit);
#endif
		return;
	}
	if (p->seq != (sc->sc_rs.rs_SOReqCnt - 1)) {
#ifdef WLP_DEBUG
		printf("\tERROR: Invalid Sequence Number %d (expected %d)\n",
		       p->seq, sc->sc_rs.rs_SOReqCnt);
#endif
		return;
	}
	if (p->status != 0) {
#ifdef WLP_DEBUG
		printf("\tERROR: Sign-on Request Rejected (status = %d)\n",
		       p->status);
#endif
		return;
	}
	/*
	 * Save the Access Point Information...
	 */
	if (p->infoblock[0] > SORSP_INFOBLOCK_MAX_LEN - 1) {
#ifdef WLP_DEBUG
		printf("\tERROR: Sign-on Request has invalid infoblock length (%d)\n",
		       p->infoblock[0]);
#endif
		return;
	}
	bcopy(p->infoblock, sc->sc_rs.rs_apreg->ap_infoblock, p->infoblock[0] + 1);

	/* NWID Promisc Mode */
	SetNWID(sc, sc->sc_rs.rs_apreg->ap_beacon.snwid, 1);
	EnableTX(ifp);
	sc->sc_rs.rs_SOReqRetrans = 0;

	if (sc->sc_rs.rs_ap == 0 && sc->sc_rs.rs_SOReqFailed) {
		/* Initial Sign-ON */
		SendRECReq(sc);	/* XXX */
	}
	sc->sc_rs.rs_ap = sc->sc_rs.rs_apreg;
	sc->sc_rs.rs_apreg = 0;

#ifdef WLP_DEBUG
	printf("-------------------- New Access Point --------------------\n");
	dump_ap(sc->sc_rs.rs_ap);
#endif

}


/*
 * ======================================================================
 * Packet Building Functions...
 * ======================================================================
 */
static void
SendSOReq(sc, a)
	struct wlp_softc *sc;
	struct accesspoint *a;
{
	struct mbuf *m;
	struct ether_header *eh;
	struct pkt_soreq *p;

	MGETHDR(m, M_DONTWAIT, MT_HEADER);
	if (!m) return;

	eh = mtod(m, struct ether_header *);
	bzero((caddr_t) eh, MHLEN);

	/*
	 * Insert the SNAP goop...
	 */
	bcopy(ether_wavelan_snaphdr, (caddr_t) (eh + 1),
	      sizeof(ether_wavelan_snaphdr));

	/*
	 * Insert the Sign On Request stuff...
	 */
	p = (struct pkt_soreq *)
		(((caddr_t) (eh + 1)) + sizeof(ether_wavelan_snaphdr));
	p->pdutype = PDUTYPE_SOREQ;	/* Sign-On Request */
	p->seq = sc->sc_rs.rs_SOReqCnt++;	/* Not used by base station */
	p->numaps = 0x00;	/* Not Presently Used */
	p->roamstate = 0x00;	/* Not Presently Used */
	p->reserved = 0x00;	/* SHOULD be 0x00 */

	m->m_len = sizeof(*eh) + sizeof(ether_wavelan_snaphdr) +
		sizeof(struct pkt_soreq);

	if (sc->sc_rs.rs_ap && sc->sc_rs.rs_ap->ap_infoblock[0]) {
		bcopy(sc->sc_rs.rs_ap->ap_infoblock,
		      p->infoblock,
		      sc->sc_rs.rs_ap->ap_infoblock[0]);
		m->m_len += sc->sc_rs.rs_ap->ap_infoblock[0];
	}
	/*
	 * Fill in the Ethernet header...
	 */
	bcopy(a->ap_softc->sc_ac.ac_enaddr, eh->ether_shost, ETHER_ADDR_LEN);
	bcopy(a->ap_macaddr, eh->ether_dhost, ETHER_ADDR_LEN);
	eh->ether_type = htons(m->m_len - sizeof(*eh));

	m->m_pkthdr.len = m->m_len =
		BEACON_MIN_LEN + sizeof(ether_wavelan_snaphdr);

	sc->sc_rs.rs_SOReqRetrans++;	/* Increment Sign-ON Counter */

	wlptransmit(sc, m);
	m_freem(m);

#ifdef WLP_DEBUG
	printf("-------------------- Registering --------------------\n");
	dump_ap(a);
#endif
}


static void
SendRECReq(sc)
	struct wlp_softc *sc;
{
	struct mbuf *m;
	struct ether_header *eh;
	struct pkt_recreq *p;

	MGETHDR(m, M_DONTWAIT, MT_HEADER);
	if (m == 0)
		return;

	eh = mtod(m, struct ether_header *);
	p = (struct pkt_recreq *)
		(((caddr_t) (eh + 1)) + sizeof(ether_wavelan_snaphdr));
	bzero((caddr_t) eh, MHLEN);

	/* Ethernet Header */
	bcopy(sc->sc_ac.ac_enaddr, eh->ether_shost, ETHER_ADDR_LEN);
	bcopy(ether_bridge_multiaddr, eh->ether_dhost, ETHER_ADDR_LEN);
	eh->ether_type = htons(sizeof(ether_wavelan_snaphdr) +
			       sizeof(struct pkt_recreq));

	/* SNAP Header */
	bcopy(ether_wavelan_snaphdr, (caddr_t) (eh + 1),
	      sizeof(ether_wavelan_snaphdr));

	/* WaveLAN Stuff */
	p->pdutype = PDUTYPE_RECREQ;

	m->m_pkthdr.len = m->m_len = sizeof(*eh) +
		sizeof(ether_wavelan_snaphdr) + sizeof(struct pkt_recreq) +
		RECREQ_PADDING_LEN;

	wlptransmit(sc, m);
	m_freem(m);

	sc->sc_rs.rs_SOReqFailed = 0;
}

/* ====================================================================== */

#ifdef WLP_DEBUG

static void
dump_ap(a)
	struct accesspoint *a;
{
	if (!a)
		return;

	printf("NAME: %s, MAC ADDR: %02x:%02x:%02x:%02x:%02x:%02x, NWID: %x\n",
	       a->ap_beacon.apname, ETHER_ADDR_FORMAT(a->ap_macaddr),
	       a->ap_beacon.snwid);
	printf("\tEXPIRE: %ld.%ld, INTERVAL: %d, TIMEOUT: %d\n",
	       a->ap_expire.tv_sec, a->ap_expire.tv_usec,
               *((u_int16_t*) a->ap_beacon.interval),
	       *((u_int16_t*) a->ap_beacon.timeout));
	printf("\tSIGNAL: %2d %2d %2d %2d, THRESHOLD: %2d %2d %2d\n",
	a->ap_siglevel, a->ap_sillevel, a->ap_sigqual, a->ap_beacon.rfnoise,
	       a->ap_beacon.scell, a->ap_beacon.rcell, a->ap_beacon.fcell);
}

static void
dump_aplist(sc)
	struct wlp_softc *sc;
{
	struct accesspoint *a;

	printf("----------------------------------------\n");
	for (a = sc->sc_rs.rs_aplist.lh_first; a; a = a->ap_link.le_next)
		dump_ap(a);

	printf("********* Current Base Station (mode: %s, time: %ld.%ld)\n",
	       RoamModeString[sc->sc_rs.rs_roam_mode],
	       time.tv_sec, time.tv_usec);
	dump_ap(sc->sc_rs.rs_ap);
	printf("----------------------------------------\n");
}

#endif /* WLP_DEBUG */

#endif /* NCARD > 0 */

#endif /* WAVELAN_ROAMING */