/* * 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 limRoamingAlgo.cc contains the code for LIM * algorithms. * Author: Chandra Modumudi * Date: 03/01/02 * History:- * Date Modified by Modification Information * -------------------------------------------------------------------- * */ #include "wniCfg.h" #include "cfgApi.h" #include "limTypes.h" #include "limTimerUtils.h" #include "limTrace.h" /** ---------------------------------------------------------------------- \fn limSelectsBackgroundScanMode() \brief This function is called by limIsBackgroundScanAllowed(). \ Here LIM decides whether we shall enforce this background \ scan or let HAL decide whether to proceed with the background \ scan as HAL sees fits. LIM shall enforce background scan if: \ 1) station is not in link established state \ 2) station is in link established state, but there has been \ max number of consecutive background scan failure. \ \param tpAniSirGlobal pMac \return none \ ------------------------------------------------------------------------- */ tSirBackgroundScanMode limSelectsBackgroundScanMode(tpAniSirGlobal pMac) { tANI_U32 cfgVal; if (wlan_cfgGetInt(pMac, WNI_CFG_MAX_CONSECUTIVE_BACKGROUND_SCAN_FAILURE, &cfgVal) != eSIR_SUCCESS) { limLog(pMac, LOGP, FL("Fail to get WNI_CFG_MAX_CONSECUTIVE_BACKGROUND_SCAN_FAILURE value")); return eSIR_NORMAL_BACKGROUND_SCAN; } if (cfgVal == 0) return eSIR_NORMAL_BACKGROUND_SCAN; /* If the "number of consecutive background scan failure" * exceeds the maximum allowed, then LIM shall trigger an * aggressive background scan. */ if (pMac->lim.gLimNumOfConsecutiveBkgndScanFailure >= cfgVal) { pMac->lim.gLimNumOfForcedBkgndScan += 1; limLog(pMac, LOGE, FL("Had %d consec scan fail(when expect < %d). Trigger AGGRESSIVE bkgnd scan."), pMac->lim.gLimNumOfConsecutiveBkgndScanFailure, cfgVal); return eSIR_AGGRESSIVE_BACKGROUND_SCAN; } return eSIR_NORMAL_BACKGROUND_SCAN; } /** ----------------------------------------------------------- \fn limIsBackgroundScanAllowed \brief This function determines if background scan should be \ allowed. It is called by limTriggerBackgroundScan(). \param tpAniSirGlobal pMac \return none \ ------------------------------------------------------------- */ static tANI_U8 limIsBackgroundScanAllowed(tpAniSirGlobal pMac) { // if we are in the middle of a scan already, skip the background scan if (limIsSystemInScanState(pMac) || (pMac->lim.gLimBackgroundScanDisable) || (pMac->lim.gLimForceBackgroundScanDisable) || (pMac->lim.gLimBackgroundScanTerminate)) return false; //need to do background scan in IBSS mode. if (pMac->lim.gLimSystemRole == eLIM_STA_IN_IBSS_ROLE) { if (pMac->lim.gLimSmeState != eLIM_SME_NORMAL_STATE) return false; return true; } // If station is not in link established state, then skip background scan if ( (pMac->lim.gLimSystemRole == eLIM_STA_ROLE) && (pMac->lim.gLimSmeState != eLIM_SME_LINK_EST_STATE) ) return false; /* now that we have checked for scan state, check for other transitional * states which should not be interrupted by scans */ if ((! (pMac->lim.gLimSmeState == eLIM_SME_IDLE_STATE) ) && (! (pMac->lim.gLimSmeState == eLIM_SME_JOIN_FAILURE_STATE) ) && (! (pMac->lim.gLimSmeState == eLIM_SME_LINK_EST_STATE) ) ) return false; return true; } /** --------------------------------------------------------------- \fn limTriggerBackgroundScan() \brief This function is called upon background scan interval \ when there is an exisiting link with an AP. \ SME_SCAN_REQ is issued to SME state machine with Active \ scanning is performed on one channel at a time. \ \ Assumptions: \ Valid channel list at CFG is either populated by Roaming \ algorithm upon determining/selecting a regulatory domain \ or by default has all 36 possible channels. \ \param tpAniSirGlobal pMac \return none \ ----------------------------------------------------------------- */ void limTriggerBackgroundScan(tpAniSirGlobal pMac) { tANI_U32 len = WNI_CFG_BG_SCAN_CHANNEL_LIST_LEN; tANI_U32 ssidLen = SIR_MAC_MAX_SSID_LENGTH; tSirMacChanNum bgScanChannelList[WNI_CFG_BG_SCAN_CHANNEL_LIST_LEN]; tSirSmeScanReq smeScanReq; tSirMacAddr bcAddr = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}; tSirBackgroundScanMode backgroundScan; limLog(pMac, LOG1, FL("Background Scan: %d success, %d consec fail "), pMac->lim.gLimNumOfBackgroundScanSuccess, pMac->lim.gLimNumOfConsecutiveBkgndScanFailure); if (! limIsBackgroundScanAllowed(pMac)) { PELOG1(limLog(pMac, LOG1, FL("Skipping Background Scan "));) return; } // Get background scan channel list from CFG if (wlan_cfgGetStr(pMac, WNI_CFG_BG_SCAN_CHANNEL_LIST, (tANI_U8 *) bgScanChannelList, (tANI_U32 *) &len) != eSIR_SUCCESS) { /** * Could not get Valid channel list from CFG. * Log error. */ PELOGE(limLog(pMac, LOGE, FL("could not retrieve valid channel list"));) return; } // Time to perform background scan. Prepare and issue // SME_SCAN_REQ to SME State machine smeScanReq.messageType = eWNI_SME_SCAN_REQ; smeScanReq.length = sizeof(tSirSmeScanReq); smeScanReq.bssType = eSIR_INFRASTRUCTURE_MODE; vos_mem_copy( (tANI_U8 *) smeScanReq.bssId, (tANI_U8 *) &bcAddr, sizeof(tSirMacAddr)); if (wlan_cfgGetStr(pMac, WNI_CFG_SSID, (tANI_U8 *) (smeScanReq.ssId[0].ssId), (tANI_U32 *) &ssidLen) != eSIR_SUCCESS) { /// Could not get SSID from CFG. Log error. limLog(pMac, LOGP, FL("could not retrieve SSID")); } smeScanReq.ssId[0].length = (tANI_U8) ssidLen; smeScanReq.numSsid = 1; smeScanReq.scanType = eSIR_ACTIVE_SCAN; smeScanReq.sessionId = 0; if (wlan_cfgGetInt(pMac, WNI_CFG_ACTIVE_MINIMUM_CHANNEL_TIME, &smeScanReq.minChannelTime) != eSIR_SUCCESS) { /// Could not get minChlTime value from CFG. Log error. PELOGE(limLog(pMac, LOGE, FL("could not retrieve minChlTime value"));) return; } if (wlan_cfgGetInt(pMac, WNI_CFG_ACTIVE_MAXIMUM_CHANNEL_TIME, &smeScanReq.maxChannelTime) != eSIR_SUCCESS) { /// Could not get maxChlTime value from CFG. Log error. PELOGE(limLog(pMac, LOGE, FL("could not retrieve maxChlTime value"));) return; } smeScanReq.returnAfterFirstMatch = 0; smeScanReq.returnUniqueResults = 1; //At the first channel scan, clear the cached results if(pMac->lim.gLimBackgroundScanChannelId == 0) { smeScanReq.returnFreshResults = SIR_BG_SCAN_PURGE_RESUTLS|SIR_BG_SCAN_RETURN_FRESH_RESULTS; } else { smeScanReq.returnFreshResults = SIR_BG_SCAN_RETURN_FRESH_RESULTS; } smeScanReq.channelList.numChannels = 1; if (pMac->lim.gLimBackgroundScanChannelId >= len) { pMac->lim.gLimBackgroundScanChannelId = 0; PELOGE(limLog(pMac, LOGE, FL("Skipping Background Scan since the channel list is exhausted."));) PELOGE(limLog(pMac, LOGE, FL("SME should send WNI_CFG_BACKGROUND_SCAN_PERIOD indication to start the background scan again."));) /* Stop the BG scan timer here. SME should send WNI_CFG_BACKGROUND_SCAN_PERIOD * indication to start the background scan again. */ if (TX_TIMER_VALID(pMac->lim.limTimers.gLimBackgroundScanTimer)) { MTRACE(macTrace(pMac, TRACE_CODE_TIMER_DEACTIVATE, NO_SESSION, eLIM_BACKGROUND_SCAN_TIMER)); if (tx_timer_deactivate(&pMac->lim.limTimers.gLimBackgroundScanTimer) != TX_SUCCESS) { // Could not deactivate BackgroundScanTimer timer. // Log error limLog(pMac, LOGP, FL("unable to deactivate BackgroundScanTimer timer")); } } pMac->lim.gLimBackgroundScanTerminate = TRUE; PELOGE(limLog(pMac, LOGE, FL("Send dummy scan with returnFreshResults as 0 to report BG scan results to SME."));) return; } smeScanReq.channelList.channelNumber[0] = bgScanChannelList[pMac->lim.gLimBackgroundScanChannelId++]; smeScanReq.uIEFieldLen = 0; smeScanReq.uIEFieldOffset = sizeof(tSirSmeScanReq); backgroundScan = limSelectsBackgroundScanMode(pMac); PELOG1(limLog(pMac, LOG1, FL("Performing (mode %s (%d)) Background Scan"), lim_BackgroundScanModetoString(backgroundScan), backgroundScan);) smeScanReq.backgroundScanMode = backgroundScan; //determine whether to send the results or not, If so, notify the BG scan results to SME if (pMac->lim.gLimBackgroundScanChannelId >= len) { pMac->lim.gLimReportBackgroundScanResults = TRUE; } limPostSmeMessage(pMac, eWNI_SME_SCAN_REQ, (tANI_U32 *) &smeScanReq); } /*** limTriggerBackgroundScan() ***/ /** ---------------------------------------------------------------------- \fn limAbortBackgroundScan \brief This function aborts background scan and send scan \ response to SME. \param tpAniSirGlobal pMac \return none \ ------------------------------------------------------------------------- */ void limAbortBackgroundScan(tpAniSirGlobal pMac) { tANI_U16 scanRspLen = 8; if(pMac->lim.gLimBackgroundScanTerminate == FALSE) { limLog(pMac, LOGE, FL("Abort Background Scan ")); if (TX_TIMER_VALID(pMac->lim.limTimers.gLimBackgroundScanTimer)) { limDeactivateAndChangeTimer(pMac, eLIM_BACKGROUND_SCAN_TIMER); } pMac->lim.gLimBackgroundScanTerminate = TRUE; pMac->lim.gLimBackgroundScanStarted = FALSE; if (pMac->lim.gLimSmeScanResultLength == 0) limSendSmeScanRsp(pMac, scanRspLen, eSIR_SME_SUCCESS, 0, 0); else { scanRspLen = sizeof(tSirSmeScanRsp) + pMac->lim.gLimSmeScanResultLength - sizeof(tSirBssDescription); limSendSmeScanRsp(pMac, scanRspLen, eSIR_SME_SUCCESS, 0, 0); } } // reset background scan variables pMac->lim.gLimBackgroundScanChannelId = 0; return; }