| /* |
| * 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; |
| } |
| |