Mostly from an energy consumption and cpu load perspective,
it can be useful to stop a triggered scan earlier, when one
finds the desired scan results.
Adding the ability to stop a scan from user space by exposing
new NL80211_CMD_SCAN_CANCEL API.
Signed-off-by: Victor Goldenshtein <victorg@xxxxxx>
---
include/linux/nl80211.h | 6 ++++++
include/net/cfg80211.h | 2 ++
net/wireless/core.h | 1 +
net/wireless/nl80211.c | 13 +++++++++++++
net/wireless/scan.c | 15 +++++++++++++++
5 files changed, 37 insertions(+), 0 deletions(-)
diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 3ec2f94..3468789 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -491,6 +491,11 @@
* this command may also be sent by the driver as an MLME event to
* inform userspace of the new replay counter.
*
+ * @NL80211_CMD_SCAN_CANCEL: Stop currently running scan (both sw and hw).
+ * This will eventually call ieee80211_scan_cancel() in mac80211 which
+ * will clean up scan_req resources. If we try to stop a not running
+ * scan it will return -ENOENT.
+ *
* @NL80211_CMD_MAX: highest used command number
* @__NL80211_CMD_AFTER_LAST: internal use
*/
@@ -615,6 +620,7 @@ enum nl80211_commands {
NL80211_CMD_SET_REKEY_OFFLOAD,
+ NL80211_CMD_SCAN_CANCEL,
/* add new commands above here */
/* used to define NL80211_CMD_MAX below */
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 4bf101b..0d619b9 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1334,6 +1334,7 @@ struct cfg80211_gtk_rekey_data {
* @set_ringparam: Set tx and rx ring sizes.
*
* @get_ringparam: Get tx and rx ring current and maximum sizes.
+ * @scan_cancel: Stop triggered scan, return 0 if successful.
*/
struct cfg80211_ops {
int (*suspend)(struct wiphy *wiphy, struct cfg80211_wowlan *wow);
@@ -1516,6 +1517,7 @@ struct cfg80211_ops {
int (*set_rekey_data)(struct wiphy *wiphy, struct net_device *dev,
struct cfg80211_gtk_rekey_data *data);
+ void (*scan_cancel)(struct wiphy *wiphy, struct net_device *dev);
};
/*
diff --git a/net/wireless/core.h b/net/wireless/core.h
index a570ff9..bd3a780 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -421,6 +421,7 @@ void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak);
void __cfg80211_sched_scan_results(struct work_struct *wk);
int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
bool driver_initiated);
+int cfg80211_scan_cancel(struct cfg80211_registered_device *rdev);
void cfg80211_upload_connect_keys(struct wireless_dev *wdev);
int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
struct net_device *dev, enum nl80211_iftype ntype,
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 6a82c89..023e749 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3641,6 +3641,11 @@ static int nl80211_stop_sched_scan(struct sk_buff *skb,
return err;
}
+static int nl80211_scan_cancel(struct sk_buff *skb, struct genl_info *info)
+{
+ return cfg80211_scan_cancel(info->user_ptr[0]);
+}
+
static int nl80211_send_bss(struct sk_buff *msg, struct netlink_callback *cb,
u32 seq, int flags,
struct cfg80211_registered_device *rdev,
@@ -5759,6 +5764,14 @@ static struct genl_ops nl80211_ops[] = {
NL80211_FLAG_NEED_RTNL,
},
{
+ .cmd = NL80211_CMD_SCAN_CANCEL,
+ .doit = nl80211_scan_cancel,
+ .policy = nl80211_policy,
+ .flags = GENL_ADMIN_PERM,
+ .internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
+ NL80211_FLAG_NEED_RTNL,
+ },
+ {
.cmd = NL80211_CMD_GET_SCAN,
.policy = nl80211_policy,
.dumpit = nl80211_dump_scan,
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 2cc9d4a..69259b1 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -155,6 +155,21 @@ int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
return 0;
}
+int cfg80211_scan_cancel(struct cfg80211_registered_device *rdev)
+{
+ struct net_device *dev;
+
+ ASSERT_RDEV_LOCK(rdev);
+
+ if (!rdev->ops->scan_cancel)
+ return -EOPNOTSUPP;
+ if (!rdev->scan_req)
+ return -ENOENT;
+
+ dev = rdev->scan_req->dev;
+ rdev->ops->scan_cancel(&rdev->wiphy, dev);
+ return 0;
+}
static void bss_release(struct kref *ref)
{
struct cfg80211_internal_bss *bss;
--
1.7.0.4
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