Beispiel #1
0
/**
 * hwmp_route_info_get - Update routing info to originator and transmitter
 *
 * @sdata: local mesh subif
 * @mgmt: mesh management frame
 * @hwmp_ie: hwmp information element (PREP or PREQ)
 *
 * This function updates the path routing information to the originator and the
 * transmitter of a HWMP PREQ or PREP fram.
 *
 * Returns: metric to frame originator or 0 if the frame should not be further
 * processed
 *
 * Notes: this function is the only place (besides user-provided info) where
 * path routing information is updated.
 */
static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
			    struct ieee80211_mgmt *mgmt,
			    u8 *hwmp_ie)
{
	struct ieee80211_local *local = sdata->local;
	struct mesh_path *mpath;
	struct sta_info *sta;
	bool fresh_info;
	u8 *orig_addr, *ta;
	u32 orig_dsn, orig_metric;
	unsigned long orig_lifetime, exp_time;
	u32 last_hop_metric, new_metric;
	bool process = true;
	u8 action = mgmt->u.action.u.mesh_action.action_code;

	rcu_read_lock();
	sta = sta_info_get(local, mgmt->sa);
	if (!sta) {
		rcu_read_unlock();
		return 0;
	}

	last_hop_metric = airtime_link_metric_get(local, sta);
	/* Update and check originator routing info */
	fresh_info = true;

	switch (action) {
	case MPATH_PREQ:
		orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
		orig_dsn = PREQ_IE_ORIG_DSN(hwmp_ie);
		orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
		orig_metric = PREQ_IE_METRIC(hwmp_ie);
		break;
	case MPATH_PREP:
		/* Originator here refers to the MP that was the destination in
		 * the Path Request. The draft refers to that MP as the
		 * destination address, even though usually it is the origin of
		 * the PREP frame. We divert from the nomenclature in the draft
		 * so that we can easily use a single function to gather path
		 * information from both PREQ and PREP frames.
		 */
		orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie);
		orig_dsn = PREP_IE_ORIG_DSN(hwmp_ie);
		orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
		orig_metric = PREP_IE_METRIC(hwmp_ie);
		break;
	default:
		rcu_read_unlock();
		return 0;
	}
	new_metric = orig_metric + last_hop_metric;
	if (new_metric < orig_metric)
		new_metric = MAX_METRIC;
	exp_time = TU_TO_EXP_TIME(orig_lifetime);

	if (memcmp(orig_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) {
		/* This MP is the originator, we are not interested in this
		 * frame, except for updating transmitter's path info.
		 */
		process = false;
		fresh_info = false;
	} else {
		mpath = mesh_path_lookup(orig_addr, sdata);
		if (mpath) {
			spin_lock_bh(&mpath->state_lock);
			if (mpath->flags & MESH_PATH_FIXED)
				fresh_info = false;
			else if ((mpath->flags & MESH_PATH_ACTIVE) &&
			    (mpath->flags & MESH_PATH_DSN_VALID)) {
				if (DSN_GT(mpath->dsn, orig_dsn) ||
				    (mpath->dsn == orig_dsn &&
				     action == MPATH_PREQ &&
				     new_metric > mpath->metric)) {
					process = false;
					fresh_info = false;
				}
			}
		} else {
			mesh_path_add(orig_addr, sdata);
			mpath = mesh_path_lookup(orig_addr, sdata);
			if (!mpath) {
				rcu_read_unlock();
				return 0;
			}
			spin_lock_bh(&mpath->state_lock);
		}

		if (fresh_info) {
			mesh_path_assign_nexthop(mpath, sta);
			mpath->flags |= MESH_PATH_DSN_VALID;
			mpath->metric = new_metric;
			mpath->dsn = orig_dsn;
			mpath->exp_time = time_after(mpath->exp_time, exp_time)
					  ?  mpath->exp_time : exp_time;
			mesh_path_activate(mpath);
			spin_unlock_bh(&mpath->state_lock);
			mesh_path_tx_pending(mpath);
			/* draft says preq_id should be saved to, but there does
			 * not seem to be any use for it, skipping by now
			 */
		} else
			spin_unlock_bh(&mpath->state_lock);
	}

	/* Update and check transmitter routing info */
	ta = mgmt->sa;
	if (memcmp(orig_addr, ta, ETH_ALEN) == 0)
		fresh_info = false;
	else {
		fresh_info = true;

		mpath = mesh_path_lookup(ta, sdata);
		if (mpath) {
			spin_lock_bh(&mpath->state_lock);
			if ((mpath->flags & MESH_PATH_FIXED) ||
				((mpath->flags & MESH_PATH_ACTIVE) &&
					(last_hop_metric > mpath->metric)))
				fresh_info = false;
		} else {
			mesh_path_add(ta, sdata);
			mpath = mesh_path_lookup(ta, sdata);
			if (!mpath) {
				rcu_read_unlock();
				return 0;
			}
			spin_lock_bh(&mpath->state_lock);
		}

		if (fresh_info) {
			mesh_path_assign_nexthop(mpath, sta);
			mpath->flags &= ~MESH_PATH_DSN_VALID;
			mpath->metric = last_hop_metric;
			mpath->exp_time = time_after(mpath->exp_time, exp_time)
					  ?  mpath->exp_time : exp_time;
			mesh_path_activate(mpath);
			spin_unlock_bh(&mpath->state_lock);
			mesh_path_tx_pending(mpath);
		} else
			spin_unlock_bh(&mpath->state_lock);
	}

	rcu_read_unlock();

	return process ? new_metric : 0;
}
Beispiel #2
0
/**
 * hwmp_route_info_get - Update routing info to originator and transmitter
 *
 * @sdata: local mesh subif
 * @mgmt: mesh management frame
 * @hwmp_ie: hwmp information element (PREP or PREQ)
 * @action: type of hwmp ie
 *
 * This function updates the path routing information to the originator and the
 * transmitter of a HWMP PREQ or PREP frame.
 *
 * Returns: metric to frame originator or 0 if the frame should not be further
 * processed
 *
 * Notes: this function is the only place (besides user-provided info) where
 * path routing information is updated.
 */
static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
			       struct ieee80211_mgmt *mgmt,
			       const u8 *hwmp_ie, enum mpath_frame_type action)
{
	struct ieee80211_local *local = sdata->local;
	struct mesh_path *mpath;
	struct sta_info *sta;
	bool fresh_info;
	const u8 *orig_addr, *ta;
	u32 orig_sn, orig_metric;
	unsigned long orig_lifetime, exp_time;
	u32 last_hop_metric, new_metric;
	bool process = true;

	rcu_read_lock();
	sta = sta_info_get(sdata, mgmt->sa);
	if (!sta) {
		rcu_read_unlock();
		return 0;
	}

	last_hop_metric = airtime_link_metric_get(local, sta);
	/* Update and check originator routing info */
	fresh_info = true;

	switch (action) {
	case MPATH_PREQ:
		orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
		orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
		orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
		orig_metric = PREQ_IE_METRIC(hwmp_ie);
		break;
	case MPATH_PREP:
		/* Originator here refers to the MP that was the target in the
		 * Path Request. We divert from the nomenclature in the draft
		 * so that we can easily use a single function to gather path
		 * information from both PREQ and PREP frames.
		 */
		orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie);
		orig_sn = PREP_IE_TARGET_SN(hwmp_ie);
		orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
		orig_metric = PREP_IE_METRIC(hwmp_ie);
		break;
	default:
		rcu_read_unlock();
		return 0;
	}
	new_metric = orig_metric + last_hop_metric;
	if (new_metric < orig_metric)
		new_metric = MAX_METRIC;
	exp_time = TU_TO_EXP_TIME(orig_lifetime);

	if (ether_addr_equal(orig_addr, sdata->vif.addr)) {
		/* This MP is the originator, we are not interested in this
		 * frame, except for updating transmitter's path info.
		 */
		process = false;
		fresh_info = false;
	} else {
		mpath = mesh_path_lookup(sdata, orig_addr);
		if (mpath) {
			spin_lock_bh(&mpath->state_lock);
			if (mpath->flags & MESH_PATH_FIXED)
				fresh_info = false;
			else if ((mpath->flags & MESH_PATH_ACTIVE) &&
			    (mpath->flags & MESH_PATH_SN_VALID)) {
				if (SN_GT(mpath->sn, orig_sn) ||
				    (mpath->sn == orig_sn &&
				     new_metric >= mpath->metric)) {
					process = false;
					fresh_info = false;
				}
			} else if (!(mpath->flags & MESH_PATH_ACTIVE)) {
				bool have_sn, newer_sn, bounced;

				have_sn = mpath->flags & MESH_PATH_SN_VALID;
				newer_sn = have_sn && SN_GT(orig_sn, mpath->sn);
				bounced = have_sn &&
					  (SN_DELTA(orig_sn, mpath->sn) >
							MAX_SANE_SN_DELTA);

				if (!have_sn || newer_sn) {
					/* if SN is newer than what we had
					 * then we can take it */;
				} else if (bounced) {
					/* if SN is way different than what
					 * we had then assume the other side
					 * rebooted or restarted */;
				} else {
					process = false;
					fresh_info = false;
				}
			}
		} else {
			mpath = mesh_path_add(sdata, orig_addr);
			if (IS_ERR(mpath)) {
				rcu_read_unlock();
				return 0;
			}
			spin_lock_bh(&mpath->state_lock);
		}

		if (fresh_info) {
			mesh_path_assign_nexthop(mpath, sta);
			mpath->flags |= MESH_PATH_SN_VALID;
			mpath->metric = new_metric;
			mpath->sn = orig_sn;
			mpath->exp_time = time_after(mpath->exp_time, exp_time)
					  ?  mpath->exp_time : exp_time;
			mesh_path_activate(mpath);
			spin_unlock_bh(&mpath->state_lock);
			ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
			/* init it at a low value - 0 start is tricky */
			ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
			mesh_path_tx_pending(mpath);
			/* draft says preq_id should be saved to, but there does
			 * not seem to be any use for it, skipping by now
			 */
		} else
			spin_unlock_bh(&mpath->state_lock);
	}

	/* Update and check transmitter routing info */
	ta = mgmt->sa;
	if (ether_addr_equal(orig_addr, ta))
		fresh_info = false;
	else {
		fresh_info = true;

		mpath = mesh_path_lookup(sdata, ta);
		if (mpath) {
			spin_lock_bh(&mpath->state_lock);
			if ((mpath->flags & MESH_PATH_FIXED) ||
				((mpath->flags & MESH_PATH_ACTIVE) &&
					(last_hop_metric > mpath->metric)))
				fresh_info = false;
		} else {
			mpath = mesh_path_add(sdata, ta);
			if (IS_ERR(mpath)) {
				rcu_read_unlock();
				return 0;
			}
			spin_lock_bh(&mpath->state_lock);
		}

		if (fresh_info) {
			mesh_path_assign_nexthop(mpath, sta);
			mpath->metric = last_hop_metric;
			mpath->exp_time = time_after(mpath->exp_time, exp_time)
					  ?  mpath->exp_time : exp_time;
			mesh_path_activate(mpath);
			spin_unlock_bh(&mpath->state_lock);
			ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
			/* init it at a low value - 0 start is tricky */
			ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
			mesh_path_tx_pending(mpath);
		} else
			spin_unlock_bh(&mpath->state_lock);
	}

	rcu_read_unlock();

	return process ? new_metric : 0;
}