/**************************************************************************** * wireless/ieee802154/mac802154_scan.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include "mac802154.h" #include "mac802154_internal.h" #include "mac802154_scan.h" #include /**************************************************************************** * Private Function Prototypes ****************************************************************************/ static void mac802154_scantimeout(FAR void *arg); /**************************************************************************** * Public MAC Functions ****************************************************************************/ /**************************************************************************** * Name: mac802154_req_scan * * Description: * The MLME-SCAN.request primitive is used to initiate a channel scan over * a given list of channels. A device can use a channel scan to measure the * energy on the channel, search for the coordinator with which it * associated, or search for all coordinators transmitting beacon frames * within the POS of the scanning device. Scan results are returned * via MULTIPLE calls to the struct mac802154_maccb_s->conf_scan callback. * This is a difference with the official 802.15.4 specification, * implemented here to save memory. * ****************************************************************************/ int mac802154_req_scan(MACHANDLE mac, FAR struct ieee802154_scan_req_s *req) { FAR struct ieee802154_privmac_s *priv = (FAR struct ieee802154_privmac_s *)mac; int ret; if (req->duration > 15 || req->numchan < 0 || req->numchan > 15) { ret = -EINVAL; goto errout; } wlinfo("MLME: SCAN.request received\n"); /* Need to get access to the ops semaphore since operations are serial. * This must be done before locking the MAC so that we don't hold the MAC */ ret = nxsem_wait_uninterruptible(&priv->opsem); if (ret < 0) { goto errout; } priv->curr_op = MAC802154_OP_SCAN; /* Get exclusive access to the MAC */ ret = nxmutex_lock(&priv->lock); if (ret < 0) { nxsem_post(&priv->opsem); goto errout; } /* Copy the request so we have a reference */ memcpy(&priv->currscan, req, sizeof(struct ieee802154_scan_req_s)); priv->scanindex = 0; priv->npandesc = 0; priv->scansymdur = IEEE802154_BASE_SUPERFRAME_DURATION * ((1 << req->duration) + 1); switch (req->type) { case IEEE802154_SCANTYPE_PASSIVE: { wlinfo("MLME: Starting Passive Scan\n"); /* Set the channel to the first channel in the list */ mac802154_setchannel(priv, req->channels[priv->scanindex]); mac802154_setchpage(priv, req->chpage); /* Before commencing an active or passive scan, the MAC sublayer * shall store the value of macPANId and then set it to 0xffff for * the duration of the scan. This enables the receive filter to * accept all beacons rather than just the beacons from its current * PAN, as described in 5.1.6.2. On completion of the scan, the MAC * sublayer shall restore the value of macPANId to the value stored * before the scan began. [1] pg. 24 */ IEEE802154_PANIDCOPY(priv->panidbeforescan, priv->addr.panid); mac802154_setpanid(priv, (const uint8_t *) & IEEE802154_PANID_UNSPEC); /* ...after switching to the channel for a passive scan, the device * shall enable its receiver for at most * [aBaseSuperframeDuration × (2 * n + 1)], * where n is the value of the ScanDuration parameter. [1] pg. 25 */ mac802154_rxenable(priv); mac802154_timerstart(priv, priv->scansymdur, mac802154_scantimeout); } break; case IEEE802154_SCANTYPE_ACTIVE: { ret = -ENOTTY; goto errout_with_lock; } break; case IEEE802154_SCANTYPE_ED: { wlinfo("MLME: Starting Energy Scan\n"); /* Set the channel to the first channel in the list, and trigger an * energy detect operation with the radio layer. */ mac802154_setchpage(priv, req->chpage); mac802154_setchannel(priv, req->channels[priv->scanindex]); priv->radio->energydetect(priv->radio, priv->scansymdur); } break; case IEEE802154_SCANTYPE_ORPHAN: { ret = -ENOTTY; goto errout_with_lock; } break; default: { ret = -EINVAL; goto errout_with_lock; } break; } nxmutex_unlock(&priv->lock); return OK; errout_with_lock: nxmutex_unlock(&priv->lock); nxsem_post(&priv->opsem); errout: return ret; } /**************************************************************************** * Internal MAC Functions ****************************************************************************/ void mac802154_scanfinish(FAR struct ieee802154_privmac_s *priv, enum ieee802154_status_e status) { FAR struct ieee802154_primitive_s * primitive; FAR struct ieee802154_scan_conf_s *scanconf; primitive = ieee802154_primitive_allocate(); scanconf = &primitive->u.scanconf; primitive->type = IEEE802154_PRIMITIVE_CONF_SCAN; scanconf->type = priv->currscan.type; scanconf->chpage = priv->currscan.chpage; if (priv->currscan.type == IEEE802154_SCANTYPE_ED) { /* "The list of energy measurements, one for each channel searched * during an ED scan. This parameter is null for active, passive, * and orphan scans." [1] */ memcpy(scanconf->edlist, priv->edlist, sizeof(scanconf->edlist)); memcpy(scanconf->chlist, priv->currscan.channels, sizeof(scanconf->chlist)); scanconf->numresults = priv->currscan.numchan; } else { /* "A list of the channels given in the request which were not * scanned. This parameter is not valid for ED scans." [1] */ scanconf->numunscanned = priv->currscan.numchan - priv->scanindex; if (scanconf->numunscanned) { memcpy(scanconf->chlist, &priv->currscan.channels[priv->scanindex], scanconf->numunscanned); } /* "The list of PAN descriptors, one for each beacon found during an * active or passive scan if macAutoRequest is set to TRUE. This * parameter is null for ED and orphan scans or when macAutoRequest * is set to FALSE during an active or passive scan." [1] */ if (priv->currscan.type != IEEE802154_SCANTYPE_ORPHAN && priv->autoreq) { memcpy(scanconf->pandescs, priv->pandescs, sizeof(struct ieee802154_pandesc_s) * priv->npandesc); scanconf->numresults = priv->npandesc; } if (priv->currscan.type == IEEE802154_SCANTYPE_PASSIVE) { /* Reset the PAN ID to the setting before the scan started */ mac802154_setpanid(priv, priv->panidbeforescan); } } scanconf->status = status; priv->curr_op = MAC802154_OP_NONE; nxsem_post(&priv->opsem); mac802154_notify(priv, primitive); } /**************************************************************************** * Name: mac802154_edscan_onresult * * Description: * Function indirectly called from the radio layer via the radiocb * edresult() call. * * Assumptions: * Called with the priv mac struct locked * ****************************************************************************/ void mac802154_edscan_onresult(FAR struct ieee802154_privmac_s *priv, uint8_t edval) { DEBUGASSERT(priv->curr_op == MAC802154_OP_SCAN && priv->currscan.type == IEEE802154_SCANTYPE_ED); /* Copy the energy value into our local list */ priv->edlist[priv->scanindex] = edval; /* If we got here it means we are done scanning that channel */ priv->scanindex++; /* Check to see if this was the last channel to scan */ if (priv->scanindex == priv->currscan.numchan) { mac802154_scanfinish(priv, IEEE802154_STATUS_SUCCESS); return; } /* Continue on with the next channel in the list */ mac802154_setchannel(priv, priv->currscan.channels[priv->scanindex]); /* ...after switching to the channel for a passive scan, the device * shall enable its receiver for at most * [aBaseSuperframeDuration × (2 * n + 1)], * where n is the value of the ScanDuration parameter. [1] pg. 25 */ priv->radio->energydetect(priv->radio, priv->scansymdur); } /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: mac802154_scantimeout * * Description: * Function registered with MAC timer that gets called via the work queue * to handle a timeout for performing a scan operation. * ****************************************************************************/ static void mac802154_scantimeout(FAR void *arg) { FAR struct ieee802154_privmac_s *priv = (FAR struct ieee802154_privmac_s *)arg; DEBUGASSERT(priv->curr_op == MAC802154_OP_SCAN); nxmutex_lock(&priv->lock); /* If we got here it means we are done scanning that channel */ mac802154_rxdisable(priv); priv->scanindex++; /* Check to see if this was the last channel to scan */ if (priv->scanindex == priv->currscan.numchan) { if (priv->npandesc > 0) { mac802154_scanfinish(priv, IEEE802154_STATUS_SUCCESS); } else { mac802154_scanfinish(priv, IEEE802154_STATUS_NO_BEACON); } nxmutex_unlock(&priv->lock); return; } mac802154_setchannel(priv, priv->currscan.channels[priv->scanindex]); /* ...after switching to the channel for a passive scan, the device * shall enable its receiver for at most * [aBaseSuperframeDuration × (2 * n + 1)], * where n is the value of the ScanDuration parameter. [1] pg. 25 */ mac802154_rxenable(priv); mac802154_timerstart(priv, priv->scansymdur, mac802154_scantimeout); nxmutex_unlock(&priv->lock); }