From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mga18.intel.com ([134.134.136.126]:30107 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750711AbeEKQty (ORCPT ); Fri, 11 May 2018 12:49:54 -0400 From: Tim Kourt To: johannes@sipsolutions.net Cc: linux-wireless@vger.kernel.org, Tim Kourt Subject: [PATCH] cfg80211: Fix support for flushing old scan results Date: Fri, 11 May 2018 09:48:35 -0700 Message-Id: <20180511164835.40161-1-tim.a.kourt@linux.intel.com> (sfid-20180511_184957_723913_31CD95FE) Sender: linux-wireless-owner@vger.kernel.org List-ID: __cfg80211_bss_expire function was incorrectly used to flush the BSS entries from the previous scan results, causing NL80211_SCAN_FLAG_FLUSH flag to have no effect. This patch is addressing the described issue by changing the semantics of the function (__cfg80211_bss_expire) parameter from a confusing expire_time (jiffies - IEEE80211_SCAN_RESULT_EXPIRE) to a simple time_to_live interval and encapsulating the needed calculations inside of the function. The rest of the function usages were changed accordingly. Note: This patch enables flushing of the non-hidden BSSs. Signed-off-by: Tim Kourt --- net/wireless/scan.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/net/wireless/scan.c b/net/wireless/scan.c index d36c3eb..d459457 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -71,7 +71,7 @@ module_param(bss_entries_limit, int, 0644); MODULE_PARM_DESC(bss_entries_limit, "limit to number of scan BSS entries (per wiphy, default 1000)"); -#define IEEE80211_SCAN_RESULT_EXPIRE (30 * HZ) +#define IEEE80211_SCAN_RESULT_TIME_TO_LIVE (30 * HZ) static void bss_free(struct cfg80211_internal_bss *bss) { @@ -160,7 +160,7 @@ static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev, } static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev, - unsigned long expire_time) + unsigned long time_to_live) { struct cfg80211_internal_bss *bss, *tmp; bool expired = false; @@ -170,7 +170,8 @@ static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev, list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) { if (atomic_read(&bss->hold)) continue; - if (!time_after(expire_time, bss->ts)) + + if (!time_after(jiffies, bss->ts + time_to_live)) continue; if (__cfg80211_unlink_bss(rdev, bss)) @@ -181,6 +182,11 @@ static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev, rdev->bss_generation++; } +static void __cfg80211_bss_expire_all(struct cfg80211_registered_device *rdev) +{ + __cfg80211_bss_expire(rdev, 0); +} + static bool cfg80211_bss_expire_oldest(struct cfg80211_registered_device *rdev) { struct cfg80211_internal_bss *bss, *oldest = NULL; @@ -251,7 +257,7 @@ void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, request->flags & NL80211_SCAN_FLAG_FLUSH) { /* flush entries from previous scans */ spin_lock_bh(&rdev->bss_lock); - __cfg80211_bss_expire(rdev, request->scan_start); + __cfg80211_bss_expire_all(rdev); spin_unlock_bh(&rdev->bss_lock); } @@ -380,7 +386,7 @@ void cfg80211_sched_scan_results_wk(struct work_struct *work) if (req->flags & NL80211_SCAN_FLAG_FLUSH) { /* flush entries from previous scans */ spin_lock_bh(&rdev->bss_lock); - __cfg80211_bss_expire(rdev, req->scan_start); + __cfg80211_bss_expire_all(rdev); spin_unlock_bh(&rdev->bss_lock); req->scan_start = jiffies; } @@ -477,7 +483,7 @@ void cfg80211_bss_age(struct cfg80211_registered_device *rdev, void cfg80211_bss_expire(struct cfg80211_registered_device *rdev) { - __cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE); + __cfg80211_bss_expire(rdev, IEEE80211_SCAN_RESULT_TIME_TO_LIVE); } const u8 *cfg80211_find_ie_match(u8 eid, const u8 *ies, int len, @@ -738,7 +744,8 @@ struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy, if (!is_valid_ether_addr(bss->pub.bssid)) continue; /* Don't get expired BSS structs */ - if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) && + if (time_after(now, bss->ts + + IEEE80211_SCAN_RESULT_TIME_TO_LIVE) && !atomic_read(&bss->hold)) continue; if (is_bss(&bss->pub, bssid, ssid, ssid_len)) { -- 2.9.4