A new attribute NL80211_ATTR_SCAN_SOCKET_OWNER can be set by the
scan initiator. If present, the attribute will cause the scan to
be stopped if the client dies.
Signed-off-by: Jukka Rissanen <[email protected]>
---
include/net/cfg80211.h | 2 ++
include/uapi/linux/nl80211.h | 8 ++++++++
net/wireless/nl80211.c | 35 +++++++++++++++++++++++++++++++++++
3 files changed, 45 insertions(+)
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 220d5f5..84378bf 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1512,6 +1512,8 @@ struct cfg80211_sched_scan_request {
struct wiphy *wiphy;
struct net_device *dev;
unsigned long scan_start;
+ u32 owner_nlportid;
+ struct work_struct sched_scan_stop_wk;
/* keep last */
struct ieee80211_channel *channels[0];
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 442369f..2731a04 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -1669,6 +1669,11 @@ enum nl80211_commands {
* @NL80211_ATTR_SMPS_MODE: SMPS mode to use (ap mode). see
* &enum nl80211_smps_mode.
*
+ * @NL80211_ATTR_SCAN_SOCKET_OWNER: flag attribute, if set during scheduled
+ * scan start then the new scan req will be owned by the netlink socket
+ * that created it and the pending scan will be stopped when the socket
+ * is closed.
+ *
* @NL80211_ATTR_MAX: highest attribute number currently defined
* @__NL80211_ATTR_AFTER_LAST: internal use
*/
@@ -2021,6 +2026,8 @@ enum nl80211_attrs {
NL80211_ATTR_SMPS_MODE,
+ NL80211_ATTR_SCAN_SOCKET_OWNER,
+
/* add attributes here, update the policy in nl80211.c */
__NL80211_ATTR_AFTER_LAST,
@@ -2056,6 +2063,7 @@ enum nl80211_attrs {
#define NL80211_ATTR_KEY NL80211_ATTR_KEY
#define NL80211_ATTR_KEYS NL80211_ATTR_KEYS
#define NL80211_ATTR_FEATURE_FLAGS NL80211_ATTR_FEATURE_FLAGS
+#define NL80211_ATTR_SCAN_SOCKET_OWNER NL80211_ATTR_SCAN_SOCKET_OWNER
#define NL80211_MAX_SUPP_RATES 32
#define NL80211_MAX_SUPP_HT_RATES 77
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index d0a8361..653f649 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -395,6 +395,7 @@ static const struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] = {
[NL80211_ATTR_USER_PRIO] = { .type = NLA_U8 },
[NL80211_ATTR_ADMITTED_TIME] = { .type = NLA_U16 },
[NL80211_ATTR_SMPS_MODE] = { .type = NLA_U8 },
+ [NL80211_ATTR_SCAN_SOCKET_OWNER] = { .type = NLA_FLAG },
};
/* policy for the key attributes */
@@ -5681,6 +5682,21 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
return err;
}
+static void nl80211_sched_scan_stop_wk(struct work_struct *work)
+{
+ struct cfg80211_sched_scan_request *req;
+ struct cfg80211_registered_device *rdev;
+
+ req = container_of(work, struct cfg80211_sched_scan_request,
+ sched_scan_stop_wk);
+
+ rdev = wiphy_to_rdev(req->wiphy);
+
+ rtnl_lock();
+ __cfg80211_stop_sched_scan(rdev, false);
+ rtnl_unlock();
+}
+
static int nl80211_start_sched_scan(struct sk_buff *skb,
struct genl_info *info)
{
@@ -5955,6 +5971,13 @@ static int nl80211_start_sched_scan(struct sk_buff *skb,
err = rdev_sched_scan_start(rdev, dev, request);
if (!err) {
+ if (info->attrs[NL80211_ATTR_SCAN_SOCKET_OWNER]) {
+ INIT_WORK(&request->sched_scan_stop_wk,
+ nl80211_sched_scan_stop_wk);
+
+ request->owner_nlportid = info->snd_portid;
+ }
+
rdev->sched_scan_req = request;
nl80211_send_sched_scan(rdev, dev,
NL80211_CMD_START_SCHED_SCAN);
@@ -12127,6 +12150,12 @@ static int nl80211_netlink_notify(struct notifier_block * nb,
list_for_each_entry_rcu(rdev, &cfg80211_rdev_list, list) {
bool schedule_destroy_work = false;
+ bool schedule_scan_stop = false;
+ struct cfg80211_sched_scan_request *req = rdev->sched_scan_req;
+
+ if (req && req->owner_nlportid == notify->portid &&
+ notify->portid)
+ schedule_scan_stop = true;
list_for_each_entry_rcu(wdev, &rdev->wdev_list, list) {
cfg80211_mlme_unregister_socket(wdev, notify->portid);
@@ -12157,6 +12186,12 @@ static int nl80211_netlink_notify(struct notifier_block * nb,
spin_unlock(&rdev->destroy_list_lock);
schedule_work(&rdev->destroy_work);
}
+ } else if (schedule_scan_stop) {
+ req->owner_nlportid = 0;
+
+ if (rdev->ops->sched_scan_stop &&
+ rdev->wiphy.flags & WIPHY_FLAG_SUPPORTS_SCHED_SCAN)
+ schedule_work(&req->sched_scan_stop_wk);
}
}
--
1.8.3.1
On Tue, 2014-11-11 at 16:27 +0200, Jukka Rissanen wrote:
> +static void nl80211_sched_scan_stop_wk(struct work_struct *work)
> +{
> + struct cfg80211_sched_scan_request *req;
> + struct cfg80211_registered_device *rdev;
> +
> + req = container_of(work, struct cfg80211_sched_scan_request,
> + sched_scan_stop_wk);
> +
> + rdev = wiphy_to_rdev(req->wiphy);
> +
> + rtnl_lock();
> + __cfg80211_stop_sched_scan(rdev, false);
> + rtnl_unlock();
> +}
I think you'll need to do something like flush this (which probably
isn't possible due to RTNL usage) when the interface disappears?
Otherwise interface going down and socket closure could race, ifdown
causing the request to be aborted by socket closure having scheduled the
work ... that'd be troubling.
johannes
On Tue, 2014-11-11 at 16:27 +0200, Jukka Rissanen wrote:
> A new attribute NL80211_ATTR_SCAN_SOCKET_OWNER can be set by the
> scan initiator. If present, the attribute will cause the scan to
> be stopped if the client dies.
We already have NL80211_ATTR_IFACE_SOCKET_OWNER, maybe we can repurpose
this flag to a more general "owner" flag?
Of course we need to keep ABI (same attribute number) and API (a
#define) but that's not an issue.
johannes