ieee80211_node.c

Linux下wifi实现

			IEEE80211_NODE_UNLOCK(nt);
			(*f)(arg, ni);
			ieee80211_free_node(ni);
			goto restart;
		}
	}
	IEEE80211_NODE_UNLOCK(nt);

	IEEE80211_SCAN_UNLOCK_IRQ(nt);
}
EXPORT_SYMBOL(ieee80211_iterate_nodes);

void
ieee80211_dump_node(struct ieee80211_node_table *nt, struct ieee80211_node *ni)
{
	int i;

	printf("0x%p: mac %s refcnt %d\n", ni,
		ether_sprintf(ni->ni_macaddr), ieee80211_node_refcnt(ni));
	printf("\tscangen %u authmode %u flags 0x%x\n",
		ni->ni_scangen, ni->ni_authmode, ni->ni_flags);
	printf("\tassocid 0x%x txpower %u vlan %u\n",
		ni->ni_associd, ni->ni_txpower, ni->ni_vlan);
	printf ("rxfragstamp %u\n", ni->ni_rxfragstamp);
	for (i = 0; i < 17; i++) {
		printf("\t%d: txseq %u rxseq %u fragno %u\n", i, 
		       ni->ni_txseqs[i],
		       ni->ni_rxseqs[i] >> IEEE80211_SEQ_SEQ_SHIFT,
		       ni->ni_rxseqs[i] & IEEE80211_SEQ_FRAG_MASK);
	}
	printf("\trstamp %u rssi %u intval %u capinfo 0x%x\n",
		ni->ni_rstamp, ni->ni_rssi, ni->ni_intval, ni->ni_capinfo);
	printf("\tbssid %s essid \"%.*s\" channel %u:0x%x\n",
		ether_sprintf(ni->ni_bssid),
		ni->ni_esslen, ni->ni_essid,
		ni->ni_chan != IEEE80211_CHAN_ANYC ?
			ni->ni_chan->ic_freq : IEEE80211_CHAN_ANY,
		ni->ni_chan != IEEE80211_CHAN_ANYC ? ni->ni_chan->ic_flags : 0);
	printf("\tinact %u txrate %u\n",
		ni->ni_inact, ni->ni_txrate);
}

void
ieee80211_dump_nodes(struct ieee80211_node_table *nt)
{
	ieee80211_iterate_nodes(nt,
		(ieee80211_iter_func *) ieee80211_dump_node, nt);
}

/*
 * Handle a station joining an 11g network.
 */
static void
ieee80211_node_join_11g(struct ieee80211_node *ni)
{
	struct ieee80211com *ic = ni->ni_ic;
	struct ieee80211vap *vap = ni->ni_vap;

	IEEE80211_LOCK_ASSERT(ic);

	KASSERT(IEEE80211_IS_CHAN_ANYG(ic->ic_bsschan),
	     ("not in 11g, bss %u:0x%x, curmode %u", ic->ic_bsschan->ic_freq,
	      ic->ic_bsschan->ic_flags, ic->ic_curmode));

	/*
	 * Station isn't capable of short slot time.  Bump
	 * the count of long slot time stations and disable
	 * use of short slot time.  Note that the actual switch
	 * over to long slot time use may not occur until the
	 * next beacon transmission (per sec. 7.3.1.4 of 11g).
	 */
	if ((ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME) == 0) {
		ic->ic_longslotsta++;
		IEEE80211_NOTE(vap, IEEE80211_MSG_ASSOC, ni,
			"station needs long slot time, count %d",
			ic->ic_longslotsta);
		/* XXX vap's w/ conflicting needs won't work */
		if (!IEEE80211_IS_CHAN_108G(ic->ic_bsschan)) {
			/*
			 * Don't force slot time when switched to turbo
			 * mode as non-ERP stations won't be present; this
			 * need only be done when on the normal G channel.
			 */
			ieee80211_set_shortslottime(ic, 0);
		}
	}
	/*
	 * If the new station is not an ERP station
	 * then bump the counter and enable protection
	 * if configured.
	 */
	if (!ieee80211_iserp_rateset(ic, &ni->ni_rates)) {
		ic->ic_nonerpsta++;
		IEEE80211_NOTE(vap, IEEE80211_MSG_ASSOC, ni,
			"station is !ERP, %d non-ERP stations associated",
			ic->ic_nonerpsta);
		/*
		 * If protection is configured, enable it.
		 */
		if (ic->ic_protmode != IEEE80211_PROT_NONE) {
			IEEE80211_DPRINTF(vap, IEEE80211_MSG_ASSOC,
				"%s: enable use of protection\n", __func__);
			ic->ic_flags |= IEEE80211_F_USEPROT;
		}
		/*
		 * If station does not support short preamble
		 * then we must enable use of Barker preamble.
		 */
		if ((ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_PREAMBLE) == 0) {
			IEEE80211_NOTE(vap, IEEE80211_MSG_ASSOC, ni,
				"%s", "station needs long preamble");
			ic->ic_flags |= IEEE80211_F_USEBARKER;
			ic->ic_flags &= ~IEEE80211_F_SHPREAMBLE;
		}

		/* Update ERP element if this is first non ERP station */
		if (ic->ic_nonerpsta == 1)
			ic->ic_flags_ext |= IEEE80211_FEXT_ERPUPDATE;
	} else
		ni->ni_flags |= IEEE80211_NODE_ERP;
}

void
ieee80211_node_join(struct ieee80211_node *ni, int resp)
{
	struct ieee80211com *ic = ni->ni_ic;
	struct ieee80211vap *vap = ni->ni_vap;
	int newassoc;

	if (ni->ni_associd == 0) {
		u_int16_t aid;

		KASSERT(vap->iv_aid_bitmap != NULL, ("no aid bitmap"));
		/*
		 * It would be good to search the bitmap
		 * more efficiently, but this will do for now.
		 */
		for (aid = 1; aid < vap->iv_max_aid; aid++)
			if (!IEEE80211_AID_ISSET(vap, aid))
				break;
		if (aid >= vap->iv_max_aid) {
			IEEE80211_SEND_MGMT(ni, resp,
				IEEE80211_REASON_ASSOC_TOOMANY);
			ieee80211_node_leave(ni);
			return;
		}
		ni->ni_associd = aid | 0xc000;

		IEEE80211_LOCK_IRQ(ic);
		IEEE80211_AID_SET(vap, ni->ni_associd);
		vap->iv_sta_assoc++;
		ic->ic_sta_assoc++;
#ifdef ATH_SUPERG_XR
		if (ni->ni_vap->iv_flags & IEEE80211_F_XR)
			ic->ic_xr_sta_assoc++;
#endif
		if (IEEE80211_ATH_CAP(vap, ni, IEEE80211_ATHC_TURBOP))
			ic->ic_dt_sta_assoc++;

		if (IEEE80211_IS_CHAN_ANYG(ic->ic_bsschan))
			ieee80211_node_join_11g(ni);
		IEEE80211_UNLOCK_IRQ(ic);

		newassoc = 1;
	} else
		newassoc = 0;

	IEEE80211_NOTE(vap, IEEE80211_MSG_ASSOC | IEEE80211_MSG_DEBUG, ni,
		"station %sassociated at aid %d: %s preamble, %s slot time"
		"%s%s%s%s%s%s%s",
		newassoc ? "" : "re",
		IEEE80211_NODE_AID(ni),
		ic->ic_flags & IEEE80211_F_SHPREAMBLE ? "short" : "long",
		ic->ic_flags & IEEE80211_F_SHSLOT ? "short" : "long",
		ic->ic_flags & IEEE80211_F_USEPROT ? ", protection" : "",
		ni->ni_flags & IEEE80211_NODE_QOS ? ", QoS" : "",
		IEEE80211_ATH_CAP(vap, ni, IEEE80211_NODE_TURBOP) ?
			", turbo" : "",
		IEEE80211_ATH_CAP(vap, ni, IEEE80211_NODE_COMP) ?
			", compression" : "",
		IEEE80211_ATH_CAP(vap, ni, IEEE80211_NODE_FF) ?
			", fast-frames" : "",
		IEEE80211_ATH_CAP(vap, ni, IEEE80211_NODE_XR) ? ", XR" : "",
		IEEE80211_ATH_CAP(vap, ni, IEEE80211_NODE_AR) ? ", AR" : ""
	);

	/* give driver a chance to setup state like ni_txrate */
	if (ic->ic_newassoc != NULL)
		ic->ic_newassoc(ni, newassoc);
	ni->ni_inact_reload = vap->iv_inact_auth;
	ni->ni_inact = ni->ni_inact_reload;
	IEEE80211_SEND_MGMT(ni, resp, IEEE80211_STATUS_SUCCESS);
	/* tell the authenticator about new station */
	if (vap->iv_auth->ia_node_join != NULL)
		vap->iv_auth->ia_node_join(ni);
	ieee80211_notify_node_join(ni, newassoc);
}

/*
 * Handle a station leaving an 11g network.
 */
static void
ieee80211_node_leave_11g(struct ieee80211_node *ni)
{
	struct ieee80211com *ic = ni->ni_ic;
	struct ieee80211vap *vap = ni->ni_vap;

	IEEE80211_LOCK_ASSERT(ic);

	KASSERT(IEEE80211_IS_CHAN_ANYG(ic->ic_bsschan),
		("not in 11g, bss %u:0x%x, curmode %u",
		ic->ic_bsschan->ic_freq, ic->ic_bsschan->ic_flags,
		ic->ic_curmode));

	/*
	 * If a long slot station do the slot time bookkeeping.
	 */
	if ((ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME) == 0) {
		/* this can be 0 on mode changes from B -> G */
		if (ic->ic_longslotsta > 0)
			ic->ic_longslotsta--;
		IEEE80211_NOTE(vap, IEEE80211_MSG_ASSOC, ni,
			"long slot time station leaves, count now %d",
			ic->ic_longslotsta);
		if (ic->ic_longslotsta == 0) {
			/*
			 * Re-enable use of short slot time if supported
			 * and not operating in IBSS mode (per spec).
			 */
			if ((ic->ic_caps & IEEE80211_C_SHSLOT) &&
			    vap->iv_opmode != IEEE80211_M_IBSS) {
				IEEE80211_DPRINTF(vap, IEEE80211_MSG_ASSOC,
					"%s: re-enable use of short slot time\n",
					__func__);
				ieee80211_set_shortslottime(ic, 1);
			}
		}
	}
	/*
	 * If a non-ERP station do the protection-related bookkeeping.
	 */
	if ((ni->ni_flags & IEEE80211_NODE_ERP) == 0) {
		/* this can be 0 on mode changes from B -> G */
		if (ic->ic_nonerpsta > 0)
			ic->ic_nonerpsta--;
		IEEE80211_NOTE(vap, IEEE80211_MSG_ASSOC, ni,
			"non-ERP station leaves, count now %d", ic->ic_nonerpsta);
		if (ic->ic_nonerpsta == 0) {
			IEEE80211_DPRINTF(vap, IEEE80211_MSG_ASSOC,
				"%s: disable use of protection\n", __func__);
			ic->ic_flags &= ~IEEE80211_F_USEPROT;
			/* XXX verify mode? */
			if (ic->ic_caps & IEEE80211_C_SHPREAMBLE) {
				IEEE80211_DPRINTF(vap, IEEE80211_MSG_ASSOC,
					"%s: re-enable use of short preamble\n",
					__func__);
				ic->ic_flags |= IEEE80211_F_SHPREAMBLE;
				ic->ic_flags &= ~IEEE80211_F_USEBARKER;
			}
			ic->ic_flags_ext |= IEEE80211_FEXT_ERPUPDATE;
		}
	}
}

/*
 * Handle bookkeeping for a station/neighbor leaving
 * the bss when operating in ap or adhoc modes.
 */
void
ieee80211_node_leave(struct ieee80211_node *ni)
{
	struct ieee80211com *ic = ni->ni_ic;
	struct ieee80211vap *vap = ni->ni_vap;
	struct ieee80211_node_table *nt = ni->ni_table;

	IEEE80211_NOTE(vap, IEEE80211_MSG_ASSOC | IEEE80211_MSG_DEBUG, ni,
		"station with aid %d leaves (refcnt %u)",
		IEEE80211_NODE_AID(ni), ieee80211_node_refcnt(ni));

	/*
	 * If node wasn't previously associated all
	 * we need to do is reclaim the reference.
	 */
	/* XXX ibss mode bypasses 11g and notification */
	if (ni->ni_associd == 0)
		goto done;
	/*
	 * Tell the authenticator the station is leaving.
	 * Note that we must do this before yanking the
	 * association id as the authenticator uses the
	 * associd to locate it's state block.
	 */
	if (vap->iv_auth->ia_node_leave != NULL)
		vap->iv_auth->ia_node_leave(ni);

	IEEE80211_LOCK_IRQ(ic);
	if (vap->iv_aid_bitmap != NULL)
		IEEE80211_AID_CLR(vap, ni->ni_associd);
	ni->ni_associd = 0;
	vap->iv_sta_assoc--;
	ic->ic_sta_assoc--;
#ifdef ATH_SUPERG_XR
	if (ni->ni_vap->iv_flags & IEEE80211_F_XR)
		ic->ic_xr_sta_assoc--;
#endif
	if (IEEE80211_ATH_CAP(vap, ni, IEEE80211_ATHC_TURBOP))
		ic->ic_dt_sta_assoc--;

	if (IEEE80211_IS_CHAN_ANYG(ic->ic_bsschan))
		ieee80211_node_leave_11g(ni);
	IEEE80211_UNLOCK_IRQ(ic);
	/*
	 * Cleanup station state.  In particular clear various
	 * state that might otherwise be reused if the node
	 * is reused before the reference count goes to zero
	 * (and memory is reclaimed).
	 */
	ieee80211_sta_leave(ni);
done:
	/*
	 * Remove the node from any table it's recorded in and
	 * drop the caller's reference.  Removal from the table
	 * is important to ensure the node is not reprocessed
	 * for inactivity.
	 */
	if (nt != NULL) {
		IEEE80211_NODE_LOCK_IRQ(nt);
		node_reclaim(nt, ni);
		IEEE80211_NODE_UNLOCK_IRQ(nt);
		ieee80211_remove_wds_addr(nt,ni->ni_macaddr);
		ieee80211_del_wds_node(nt,ni);
	} else
		ieee80211_free_node(ni);
}
EXPORT_SYMBOL(ieee80211_node_leave);

u_int8_t
ieee80211_getrssi(struct ieee80211com *ic)
{
#define	NZ(x)	((x) == 0 ? 1 : (x))
	struct ieee80211_node_table *nt = &ic->ic_sta;
	struct ieee80211vap *vap;
	u_int32_t rssi_samples, rssi_total;
	struct ieee80211_node *ni;

	rssi_total = 0;
	rssi_samples = 0;
	switch (ic->ic_opmode) {
	case IEEE80211_M_IBSS:		/* average of all ibss neighbors */
		/* XXX locking */
		TAILQ_FOREACH(ni, &nt->nt_node, ni_list)
			if (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) {
				rssi_samples++;
				rssi_total += ic->ic_node_getrssi(ni);
			}
		break;
	case IEEE80211_M_AHDEMO:	/* average of all neighbors */
		/* XXX locking */
		TAILQ_FOREACH(ni, &nt->nt_node, ni_list) {
			if (memcmp(ni->ni_vap->iv_myaddr, ni->ni_macaddr, 
						IEEE80211_ADDR_LEN)!=0) {
				rssi_samples++;
				rssi_total += ic->ic_node_getrssi(ni);
			}
		}
		break;
	case IEEE80211_M_HOSTAP:	/* average of all associated stations */
		/* XXX locking */
		TAILQ_FOREACH(ni, &nt->nt_node, ni_list)
			if (IEEE80211_AID(ni->ni_associd) != 0) {
				rssi_samples++;
				rssi_total += ic->ic_node_getrssi(ni);
			}
		break;
	case IEEE80211_M_MONITOR:	/* XXX */
	case IEEE80211_M_STA:		/* use stats from associated ap */
	default:
		TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next)
			if (vap->iv_bss != NULL) {
				rssi_samples++;
				rssi_total += ic->ic_node_getrssi(vap->iv_bss);
			}
		break;
	}
	return rssi_total / NZ(rssi_samples);
#undef NZ
}
EXPORT_SYMBOL(ieee80211_getrssi);

void
ieee80211_node_reset(struct ieee80211_node *ni, struct ieee80211vap *vap)
{
	if (ni != NULL) {
		struct ieee80211_node_table *nt = ni->ni_table;
		if (!nt)
			nt = &vap->iv_ic->ic_sta;
		IEEE80211_ADDR_COPY(ni->ni_bssid, vap->iv_bss->ni_bssid);
		ni->ni_prev_vap = ni->ni_vap;
		ni->ni_vap = vap;
		ni->ni_ic = vap->iv_ic;
		/* 
		 * if node not found in the node table
		 * add it to the node table .
		 */
		if(nt && ieee80211_find_node(nt, ni->ni_macaddr) != ni) {
			int hash = IEEE80211_NODE_HASH(ni->ni_macaddr);
			IEEE80211_NODE_LOCK_IRQ(nt);
			TAILQ_INSERT_TAIL(&nt->nt_node, ni, ni_list);
			LIST_INSERT_HEAD(&nt->nt_hash[hash], ni, ni_hash);
			ni->ni_table = nt;
			IEEE80211_NODE_UNLOCK_IRQ(nt);
		}
	}
}