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 results (e.g. on resume).
Flushing only happens on successful completion of a scan;
i.e. it does not happen if the scan is aborted/canceled.
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>
---
include/linux/nl80211.h | 2 ++
include/net/cfg80211.h | 4 ++++
net/wireless/nl80211.c | 1 +
net/wireless/scan.c | 31 +++++++++++++++++++++++++++----
net/wireless/sme.c | 1 +
5 files changed, 35 insertions(+), 4 deletions(-)
diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index e512baf..71400e7 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -3081,9 +3081,11 @@ 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 ed659db..cc63a3a 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -995,9 +995,11 @@ struct cfg80211_ssid {
* enum cfg80211_scan_flags - scan request control flags
*
* @CFG80211_SCAN_FLAG_LOW_PRIORITY: scan request has low priority
+ * @CFG80211_SCAN__FLAG_FLUSH: flush cache before scanning
*/
enum cfg80211_scan_flags {
CFG80211_SCAN_FLAG_LOW_PRIORITY = NL80211_SCAN_FLAG_LOW_PRIORITY,
+ CFG80211_SCAN_FLAG_FLUSH = NL80211_SCAN_FLAG_FLUSH,
};
/**
@@ -1012,6 +1014,7 @@ enum cfg80211_scan_flags {
* @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
@@ -1030,6 +1033,7 @@ struct cfg80211_scan_request {
/* internal */
struct wiphy *wiphy;
+ unsigned long scan_start;
bool aborted;
bool no_cck;
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index e4312f6..7133477 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -4347,6 +4347,7 @@ 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);
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 9730c98..392e5a9 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -20,6 +20,9 @@
#define IEEE80211_SCAN_RESULT_EXPIRE (30 * HZ)
+static void __cfg80211_bss_expire(struct cfg80211_registered_device *dev,
+ int maxage, unsigned long expire_time);
+
void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
{
struct cfg80211_scan_request *request;
@@ -47,8 +50,15 @@ void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
if (request->aborted)
nl80211_send_scan_aborted(rdev, wdev);
- else
+ else {
+ if (request->flags & CFG80211_SCAN_FLAG_FLUSH) {
+ /* flush entries from previous scans */
+ spin_lock_bh(&rdev->bss_lock);
+ __cfg80211_bss_expire(rdev, 0, request->scan_start);
+ spin_unlock_bh(&rdev->bss_lock);
+ }
nl80211_send_scan_done(rdev, wdev);
+ }
#ifdef CONFIG_CFG80211_WEXT
if (wdev->netdev && !request->aborted) {
@@ -198,7 +208,8 @@ static void __cfg80211_unlink_bss(struct cfg80211_registered_device *dev,
}
/* must hold dev->bss_lock! */
-void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
+static void __cfg80211_bss_expire(struct cfg80211_registered_device *dev,
+ int maxage, unsigned long expire_time)
{
struct cfg80211_internal_bss *bss, *tmp;
bool expired = false;
@@ -206,8 +217,14 @@ void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
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;
+ if (maxage) {
+ if (!time_after(jiffies, bss->ts + maxage))
+ continue;
+ } else {
+ if (!time_after(expire_time, bss->ts))
+ continue;
+ }
+
__cfg80211_unlink_bss(dev, bss);
expired = true;
}
@@ -216,6 +233,11 @@ void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
dev->bss_generation++;
}
+void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
+{
+ __cfg80211_bss_expire(dev, IEEE80211_SCAN_RESULT_EXPIRE, 0);
+}
+
const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
{
while (len > 2 && ies[0] != eid) {
@@ -962,6 +984,7 @@ 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 6f39cb8..dde1d47 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;
--
1.7.0.2
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