core/mac/src/pe/lim/lim_scan_result_utils.c

/*
 * Copyright (c) 2011-2015 The Linux Foundation. All rights reserved.
 *
 * Previously licensed under the ISC license by Qualcomm Atheros, Inc.
 *
 *
 * Permission to use, copy, modify, and/or distribute this software for
 * any purpose with or without fee is hereby granted, provided that the
 * above copyright notice and this permission notice appear in all
 * copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
 * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * This file was originally distributed by Qualcomm Atheros, Inc.
 * under proprietary terms before Copyright ownership was assigned
 * to the Linux Foundation.
 */

/*
 * This file lim_scan_result_utils.cc contains the utility functions
 * LIM uses for maintaining and accessing scan results on STA.
 * Author:        Chandra Modumudi
 * Date:          02/13/02
 * History:-
 * Date           Modified by    Modification Information
 * --------------------------------------------------------------------
 */

#include "lim_types.h"
#include "lim_utils.h"
#include "lim_ser_des_utils.h"
#include "lim_api.h"
#ifdef WLAN_FEATURE_VOWIFI_11R
#include "lim_ft_defs.h"
#endif
#include "lim_session.h"
#if defined WLAN_FEATURE_VOWIFI
#include "rrm_api.h"
#endif
#include "cds_utils.h"


/**
 * lim_collect_bss_description()
 *
 ***FUNCTION:
 * This function is called during scan upon receiving
 * Beacon/Probe Response frame to check if the received
 * frame matches scan criteria, collect BSS description
 * and add it to cached scan results.
 *
 ***LOGIC:
 *
 ***ASSUMPTIONS:
 * NA
 *
 ***NOTE:
 * NA
 *
 * @param  pMac - Pointer to Global MAC structure
 * @param  pBPR - Pointer to parsed Beacon/Probe Response structure
 * @param  pRxPacketInfo  - Pointer to Received frame's BD
 * ---------if defined WLAN_FEATURE_VOWIFI------
 * @param  fScanning - flag to indicate if it is during scan.
 * ---------------------------------------------
 *
 * @return None
 */
#if defined WLAN_FEATURE_VOWIFI
CDF_STATUS
lim_collect_bss_description(tpAniSirGlobal pMac,
			    tSirBssDescription *pBssDescr,
			    tpSirProbeRespBeacon pBPR,
			    uint8_t *pRxPacketInfo, uint8_t fScanning)
#else
CDF_STATUS
lim_collect_bss_description(tpAniSirGlobal pMac,
			    tSirBssDescription *pBssDescr,
			    tpSirProbeRespBeacon pBPR, uint8_t *pRxPacketInfo)
#endif
{
	uint8_t *pBody;
	uint32_t ieLen = 0;
	tpSirMacMgmtHdr pHdr;
	uint8_t channelNum;
	uint8_t rxChannel;
	uint8_t rfBand = 0;

	pHdr = WMA_GET_RX_MAC_HEADER(pRxPacketInfo);

	if (SIR_MAC_B_PR_SSID_OFFSET > WMA_GET_RX_PAYLOAD_LEN(pRxPacketInfo)) {
		CDF_ASSERT(WMA_GET_RX_PAYLOAD_LEN(pRxPacketInfo) >=
			   SIR_MAC_B_PR_SSID_OFFSET);
		return CDF_STATUS_E_FAILURE;
	}
	ieLen =
		WMA_GET_RX_PAYLOAD_LEN(pRxPacketInfo) - SIR_MAC_B_PR_SSID_OFFSET;
	rxChannel = WMA_GET_RX_CH(pRxPacketInfo);
	pBody = WMA_GET_RX_MPDU_DATA(pRxPacketInfo);
	rfBand = WMA_GET_RX_RFBAND(pRxPacketInfo);

	/**
	 * Length of BSS desription is without length of
	 * length itself and length of pointer that holds ieFields.
	 *
	 * tSirBssDescription
	 * +--------+---------------------------------+---------------+
	 * | length | other fields                    | pointer to IEs|
	 * +--------+---------------------------------+---------------+
	 *                                            ^
	 *                                            ieFields
	 */
	pBssDescr->length = (uint16_t)(offsetof(tSirBssDescription, ieFields[0])
					- sizeof(pBssDescr->length) + ieLen);

	/* Copy BSS Id */
	cdf_mem_copy((uint8_t *) &pBssDescr->bssId,
		     (uint8_t *) pHdr->bssId, sizeof(tSirMacAddr));

	/* Copy Timestamp, Beacon Interval and Capability Info */
	pBssDescr->scanSysTimeMsec = cdf_mc_timer_get_system_time();

	pBssDescr->timeStamp[0] = pBPR->timeStamp[0];
	pBssDescr->timeStamp[1] = pBPR->timeStamp[1];
	pBssDescr->beaconInterval = pBPR->beaconInterval;
	pBssDescr->capabilityInfo =
		lim_get_u16((uint8_t *) &pBPR->capabilityInfo);

	if (!pBssDescr->beaconInterval) {
		lim_log(pMac, LOGW,
			FL("Beacon Interval is ZERO, making it to default 100 "
			   MAC_ADDRESS_STR), MAC_ADDR_ARRAY(pHdr->bssId));
		pBssDescr->beaconInterval = 100;
	}
	/*
	 * There is a narrow window after Channel Switch msg is sent to HAL and before the AGC is shut
	 * down and beacons/Probe Rsps can trickle in and we may report the incorrect channel in 5Ghz
	 * band, so not relying on the 'last Scanned Channel' stored in LIM.
	 * Instead use the value returned by RXP in BD. This the the same value which HAL programs into
	 * RXP before every channel switch.
	 * Right now there is a problem in 5Ghz, where we are receiving beacons from a channel different from
	 * the currently scanned channel. so incorrect channel is reported to CSR and association does not happen.
	 * So for now we keep on looking for the channel info in the beacon (DSParamSet IE OR HT Info IE), and only if it
	 * is not present in the beacon, we go for the channel info present in RXP.
	 * This fix will work for 5Ghz 11n devices, but for 11a devices, we have to rely on RXP routing flag to get the correct channel.
	 * So The problem of incorrect channel reporting in 5Ghz will still remain for 11a devices.
	 */
	pBssDescr->channelId = lim_get_channel_from_beacon(pMac, pBPR);

	if (pBssDescr->channelId == 0) {
		/* If the channel Id is not retrieved from Beacon, extract the channel from BD */
		if (!rxChannel) {
			rxChannel = pMac->lim.gLimCurrentScanChannelId;
		}
		pBssDescr->channelId = rxChannel;
	}

	pBssDescr->channelIdSelf = pBssDescr->channelId;
	/* set the network type in bss description */
	channelNum = pBssDescr->channelId;
	pBssDescr->nwType =
		lim_get_nw_type(pMac, channelNum, SIR_MAC_MGMT_FRAME, pBPR);

	/* Copy RSSI & SINR from BD */

	lim_log(pMac, LOG4, "*********BSS Description for BSSID:********* ");
	sir_dump_buf(pMac, SIR_LIM_MODULE_ID, LOG4, pBssDescr->bssId, 6);
	sir_dump_buf(pMac, SIR_LIM_MODULE_ID, LOG4,
		(uint8_t *) pRxPacketInfo, 36);

	pBssDescr->rssi = (int8_t) WMA_GET_RX_RSSI_DB(pRxPacketInfo);

	/* SINR no longer reported by HW */
	pBssDescr->sinr = 0;

	pBssDescr->nReceivedTime = (uint32_t) cdf_mc_timer_get_system_ticks();
	pBssDescr->tsf_delta = WMA_GET_RX_TSF_DELTA(pRxPacketInfo);

	lim_log(pMac, LOG1, FL("BSSID: "MAC_ADDRESS_STR " tsf_delta = %u"),
			    MAC_ADDR_ARRAY(pHdr->bssId), pBssDescr->tsf_delta);

#if defined WLAN_FEATURE_VOWIFI
	if (fScanning) {
		rrm_get_start_tsf(pMac, pBssDescr->startTSF);
		pBssDescr->parentTSF = WMA_GET_RX_TIMESTAMP(pRxPacketInfo);
	}
#endif

#ifdef WLAN_FEATURE_VOWIFI_11R
	/* MobilityDomain */
	pBssDescr->mdie[0] = 0;
	pBssDescr->mdie[1] = 0;
	pBssDescr->mdie[2] = 0;
	pBssDescr->mdiePresent = false;
	/* If mdie is present in the probe resp we */
	/* fill it in the bss description */
	if (pBPR->mdiePresent) {
		pBssDescr->mdiePresent = true;
		pBssDescr->mdie[0] = pBPR->mdie[0];
		pBssDescr->mdie[1] = pBPR->mdie[1];
		pBssDescr->mdie[2] = pBPR->mdie[2];
	}
#endif

#ifdef FEATURE_WLAN_ESE
	pBssDescr->QBSSLoad_present = false;
	pBssDescr->QBSSLoad_avail = 0;
	if (pBPR->QBSSLoad.present) {
		pBssDescr->QBSSLoad_present = true;
		pBssDescr->QBSSLoad_avail = pBPR->QBSSLoad.avail;
	}
#endif
	/* Copy IE fields */
	cdf_mem_copy((uint8_t *) &pBssDescr->ieFields,
		     pBody + SIR_MAC_B_PR_SSID_OFFSET, ieLen);

	/*set channel number in beacon in case it is not present */
	pBPR->channelNumber = pBssDescr->channelId;

	lim_log(pMac, LOG3,
		FL("Collected BSS Description for Channel(%1d), length(%u), IE Fields(%u)"),
		pBssDescr->channelId, pBssDescr->length, ieLen);

	return CDF_STATUS_SUCCESS;
} /*** end lim_collect_bss_description() ***/

/**
 * lim_is_scan_requested_ssid()
 *
 ***FUNCTION:
 * This function is called during scan upon receiving
 * Beacon/Probe Response frame to check if the received
 * SSID is present in the list of requested SSIDs in scan
 *
 ***LOGIC:
 *
 ***ASSUMPTIONS:
 * NA
 *
 ***NOTE:
 * NA
 *
 * @param  pMac - Pointer to Global MAC structure
 * @param  ssId - SSID Received in beacons/Probe responses that is compared against the
                            requeusted SSID in scan list
 * ---------------------------------------------
 *
 * @return bool - true if SSID is present in requested list, false otherwise
 */

bool lim_is_scan_requested_ssid(tpAniSirGlobal pMac, tSirMacSSid *ssId)
{
	uint8_t i = 0;

	for (i = 0; i < pMac->lim.gpLimMlmScanReq->numSsid; i++) {
		if (true == cdf_mem_compare((uint8_t *) ssId,
					    (uint8_t *) &pMac->lim.
					    gpLimMlmScanReq->ssId[i],
					    (uint8_t) (pMac->lim.
						       gpLimMlmScanReq->ssId[i].
						       length + 1))) {
			return true;
		}
	}
	return false;
}

/**
 * lim_check_and_add_bss_description()
 * @mac_ctx: Pointer to Global MAC structure
 * @bpr: Pointer to parsed Beacon/Probe Response structure
 * @rx_packet_info: Pointer to Received frame's BD
 * @scanning: bool to indicate whether the BSS is from current scan
 *             or just happens to receive a beacon
 *
 * FUNCTION:
 * This function is called during scan upon receiving
 * Beacon/Probe Response frame to check if the received
 * frame matches scan criteria, collect BSS description
 * and add it to cached scan results.
 *
 * Return: None
 */

void
lim_check_and_add_bss_description(tpAniSirGlobal mac_ctx,
	tpSirProbeRespBeacon bpr, uint8_t *rx_packet_info,
	bool scanning, uint8_t fProbeRsp)
{
	tSirBssDescription *bssdescr = NULL;
	uint32_t frame_len, ie_len = 0;
	uint8_t rx_chan_in_beacon = 0;
	CDF_STATUS status;
	uint8_t dont_update_all = 0;
	uint8_t rf_band = 0;
	uint8_t rx_chan_bd = 0;

	tSirMacAddr bssid_zero =  {0x0, 0x0, 0x0, 0x0, 0x0, 0x0};
	tpSirMacDataHdr3a hdr;

	hdr = WMA_GET_RX_MPDUHEADER3A((uint8_t *) rx_packet_info);

	/*  Check For Null BSSID and Skip in case of P2P */
	if (cdf_mem_compare(bssid_zero, &hdr->addr3, 6))
		return;

	/*
	 * SSID/BSSID policy:
	 * Accept beacons/probe responses with any SSID or BSSID because
	 * multiple scan requests may be running at the same time and
	 * firmware may forward results to CLD from scans requested through a
	 * different path.
	 *
	 * CSA Policy:
	 * There is no point in caching & reporting the scan results for APs
	 * which are in the process of switching the channel. So, we are not
	 * caching the scan results for APs which are adverzing the
	 * channel-switch element in their beacons and probe responses.
	 */
	if (bpr->channelSwitchPresent)
		return;

	/*
	 * If beacon/probe resp DS param channel does not match with
	 * RX BD channel then don't save the results. It might be a beacon
	 * from another channel heard as noise on the current scanning channel
	 */

	if ((bpr->dsParamsPresent) || (bpr->HTInfo.present)) {
		/* This means that we are in 2.4GHz mode or 5GHz 11n mode */
		rx_chan_in_beacon = lim_get_channel_from_beacon(mac_ctx, bpr);
		rf_band = WMA_GET_RX_RFBAND(rx_packet_info);
		rx_chan_bd = WMA_GET_RX_CH(rx_packet_info);

		if (rx_chan_bd != rx_chan_in_beacon) {
			/* BCAST Frame, if CH do not match, Drop */
			if (WMA_IS_RX_BCAST(rx_packet_info)) {
				lim_log(mac_ctx, LOG3,
					FL("Beacon/Probe Rsp dropped. Channel in BD %d. Channel in beacon %d"),
					WMA_GET_RX_CH(rx_packet_info),
					lim_get_channel_from_beacon(mac_ctx,
						bpr));
				return;
			}
			/* Unit cast frame, Probe RSP, do not drop */
			else {
				dont_update_all = 1;
				lim_log(mac_ctx, LOG3,
					FL("SSID %s, CH in ProbeRsp %d, CH in BD %d, mismatch, Do Not Drop"),
					bpr->ssId.ssId, rx_chan_in_beacon,
					WMA_GET_RX_CH(rx_packet_info));
				WMA_GET_RX_CH(rx_packet_info) =
					rx_chan_in_beacon;
			}
		}
	}

	/*
	 * Allocate buffer to hold BSS description from
	 * received Beacon frame.
	 * Include size of fixed fields and IEs length
	 */

	ie_len = WMA_GET_RX_PAYLOAD_LEN(rx_packet_info);
	if (ie_len <= SIR_MAC_B_PR_SSID_OFFSET) {
		lim_log(mac_ctx, LOGP,
			FL("RX packet has invalid length %d"), ie_len);
		return;
	}

	ie_len -= SIR_MAC_B_PR_SSID_OFFSET;

	/* IEs will be overlap ieFields field. Adjust the length accordingly */
	frame_len = sizeof(*bssdescr) + ie_len - sizeof(bssdescr->ieFields[1]);
	bssdescr = (tSirBssDescription *) cdf_mem_malloc(frame_len);

	if (NULL == bssdescr) {
		/* Log error */
		lim_log(mac_ctx, LOGE,
			FL("cdf_mem_malloc(length=%d) failed"), frame_len);
		return;
	}
	/* In scan state, store scan result. */
#if defined WLAN_FEATURE_VOWIFI
	status = lim_collect_bss_description(mac_ctx, bssdescr,
					     bpr, rx_packet_info, scanning);
	if (CDF_STATUS_SUCCESS != status)
		goto last;
#else
	status = lim_collect_bss_description(mac_ctx, bssdescr,
					     bpr, rx_packet_info);
	if (CDF_STATUS_SUCCESS != status)
		goto last;
#endif
	bssdescr->fProbeRsp = fProbeRsp;

	/*
	 * Send the beacon to CSR with registered callback routine.
	 * scan_id and flags parameters are currently unused and set to 0.
	 */
	if (mac_ctx->lim.add_bssdescr_callback) {
		(mac_ctx->lim.add_bssdescr_callback) (mac_ctx, bssdescr, 0, 0);
	} else {
		lim_log(mac_ctx, LOGE,
			FL("No CSR callback routine to send beacons"));
		status = CDF_STATUS_E_INVAL;
	}
last:
	cdf_mem_free(bssdescr);
	return;
}