From: Sam Leffler <sleffler@xxxxxxxxxxxx>
Add an NL80211_SCAN_FLAG_FLUSH flag that causes old bss cache
entries to be flushed on scan completion. This is useful for
collecting guaranteed fresh scan/survey result (e.g. on resume).
For normal scan, flushing only happens on successful completion
of a scan; i.e. it does not happen if the scan is aborted.
For scheduled scan, previous scan results are flushed everytime
when we get new scan results.
Signed-off-by: Sam Leffler <sleffler@xxxxxxxxxxxx>
Tested-by: Amitkumar Karwar <akarwar@xxxxxxxxxxx>
Signed-off-by: Amitkumar Karwar <akarwar@xxxxxxxxxxx>
Signed-off-by: Bing Zhao <bzhao@xxxxxxxxxxx>
---
v3: avoid static forward declaration (Johannes Berg)
include/linux/nl80211.h | 2 +
include/net/cfg80211.h | 3 ++
net/wireless/nl80211.c | 2 +
net/wireless/scan.c | 65 ++++++++++++++++++++++++++++++++--------------
net/wireless/sme.c | 1 +
5 files changed, 53 insertions(+), 20 deletions(-)
diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index a1d5704..df1b04a 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -3092,9 +3092,11 @@ enum nl80211_connect_failed_reason {
* requests.
*
* @NL80211_SCAN_FLAG_LOW_PRIORITY: scan request has low priority
+ * @NL80211_SCAN_FLAG_FLUSH: flush cache before scanning
*/
enum nl80211_scan_flags {
NL80211_SCAN_FLAG_LOW_PRIORITY = 1<<0,
+ NL80211_SCAN_FLAG_FLUSH = 1<<1,
};
#endif /* __LINUX_NL80211_H */
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index dcad5cd..dc54c0f 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1003,6 +1003,7 @@ struct cfg80211_ssid {
* @flags: bit field of flags controlling operation
* @rates: bitmap of rates to advertise for each band
* @wiphy: the wiphy this was for
+ * @scan_start: time (in jiffies) when the scan started
* @wdev: the wireless device to scan for
* @aborted: (internal) scan request was notified as aborted
* @no_cck: used to send probe requests at non CCK rate in 2GHz band
@@ -1021,6 +1022,7 @@ struct cfg80211_scan_request {
/* internal */
struct wiphy *wiphy;
+ unsigned long scan_start;
bool aborted;
bool no_cck;
@@ -1072,6 +1074,7 @@ struct cfg80211_sched_scan_request {
/* internal */
struct wiphy *wiphy;
struct net_device *dev;
+ unsigned long scan_start;
/* keep last */
struct ieee80211_channel *channels[0];
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index b26b7f7..c562d8e 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -4376,6 +4376,7 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
request->wdev = wdev;
request->wiphy = &rdev->wiphy;
+ request->scan_start = jiffies;
rdev->scan_req = request;
err = rdev->ops->scan(&rdev->wiphy, request);
@@ -4613,6 +4614,7 @@ static int nl80211_start_sched_scan(struct sk_buff *skb,
request->dev = dev;
request->wiphy = &rdev->wiphy;
request->interval = interval;
+ request->scan_start = jiffies;
err = rdev->ops->sched_scan_start(&rdev->wiphy, dev, request);
if (!err) {
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 2005096..646a64f 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -47,6 +47,27 @@ static void __cfg80211_unlink_bss(struct cfg80211_registered_device *dev,
kref_put(&bss->ref, bss_release);
}
+/* must hold dev->bss_lock! */
+static void __cfg80211_bss_expire(struct cfg80211_registered_device *dev,
+ unsigned long expire_time)
+{
+ struct cfg80211_internal_bss *bss, *tmp;
+ bool expired = false;
+
+ list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
+ if (atomic_read(&bss->hold))
+ continue;
+ if (!time_after(expire_time, bss->ts))
+ continue;
+
+ __cfg80211_unlink_bss(dev, bss);
+ expired = true;
+ }
+
+ if (expired)
+ dev->bss_generation++;
+}
+
void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
{
struct cfg80211_scan_request *request;
@@ -72,10 +93,17 @@ void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
if (wdev->netdev)
cfg80211_sme_scan_done(wdev->netdev);
- if (request->aborted)
+ if (request->aborted) {
nl80211_send_scan_aborted(rdev, wdev);
- else
+ } else {
+ if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
+ /* flush entries from previous scans */
+ spin_lock_bh(&rdev->bss_lock);
+ __cfg80211_bss_expire(rdev, request->scan_start);
+ spin_unlock_bh(&rdev->bss_lock);
+ }
nl80211_send_scan_done(rdev, wdev);
+ }
#ifdef CONFIG_CFG80211_WEXT
if (wdev->netdev && !request->aborted) {
@@ -126,16 +154,26 @@ EXPORT_SYMBOL(cfg80211_scan_done);
void __cfg80211_sched_scan_results(struct work_struct *wk)
{
struct cfg80211_registered_device *rdev;
+ struct cfg80211_sched_scan_request *request;
rdev = container_of(wk, struct cfg80211_registered_device,
sched_scan_results_wk);
+ request = rdev->sched_scan_req;
+
mutex_lock(&rdev->sched_scan_mtx);
/* we don't have sched_scan_req anymore if the scan is stopping */
- if (rdev->sched_scan_req)
- nl80211_send_sched_scan_results(rdev,
- rdev->sched_scan_req->dev);
+ if (request) {
+ if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
+ /* flush entries from previous scans */
+ spin_lock_bh(&rdev->bss_lock);
+ __cfg80211_bss_expire(rdev, request->scan_start);
+ spin_unlock_bh(&rdev->bss_lock);
+ request->scan_start = jiffies + request->interval;
+ }
+ nl80211_send_sched_scan_results(rdev, request->dev);
+ }
mutex_unlock(&rdev->sched_scan_mtx);
}
@@ -197,23 +235,9 @@ void cfg80211_bss_age(struct cfg80211_registered_device *dev,
}
}
-/* must hold dev->bss_lock! */
void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
{
- struct cfg80211_internal_bss *bss, *tmp;
- bool expired = false;
-
- list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
- if (atomic_read(&bss->hold))
- continue;
- if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
- continue;
- __cfg80211_unlink_bss(dev, bss);
- expired = true;
- }
-
- if (expired)
- dev->bss_generation++;
+ __cfg80211_bss_expire(dev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
}
const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
@@ -962,6 +986,7 @@ int cfg80211_wext_siwscan(struct net_device *dev,
creq->ssids = (void *)&creq->channels[n_channels];
creq->n_channels = n_channels;
creq->n_ssids = 1;
+ creq->scan_start = jiffies;
/* translate "Scan on frequencies" request */
i = 0;
diff --git a/net/wireless/sme.c b/net/wireless/sme.c
index 055d596..07d717e 100644
--- a/net/wireless/sme.c
+++ b/net/wireless/sme.c
@@ -138,6 +138,7 @@ static int cfg80211_conn_scan(struct wireless_dev *wdev)
request->wdev = wdev;
request->wiphy = &rdev->wiphy;
+ request->scan_start = jiffies;
rdev->scan_req = request;
--
1.7.0.4
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