From: vamsi krishna <vamsin@xxxxxxxxxxxxxxxx>
Enhance sched scan to support option of finding a better BSS while in
connected state. Firmware scans the medium and reports when it finds a
known BSS which has better RSSI than the current connected BSS. New
attributes to specify the relative RSSI (compared to the current BSS)
are added to the sched scan to implement this.
Signed-off-by: vamsi krishna <vamsin@xxxxxxxxxxxxxxxx>
Signed-off-by: Jouni Malinen <jouni@xxxxxxxxxxxxxxxx>
---
include/net/cfg80211.h | 19 +++++++++++++++++++
include/uapi/linux/nl80211.h | 18 ++++++++++++++++++
net/wireless/nl80211.c | 29 +++++++++++++++++++++++++++--
3 files changed, 64 insertions(+), 2 deletions(-)
v2: address comments from Luca, Arend, and Johannes
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index ef42749..dcdd0c4 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1626,6 +1626,22 @@ struct cfg80211_sched_scan_plan {
* cycle. The driver may ignore this parameter and start
* immediately (or at any other time), if this feature is not
* supported.
+ * @relative_rssi: Relative RSSI threshold in dB to restrict scan result
+ * reporting in connected state to cases where a matching BSS is determined
+ * to have better RSSI than the current connected BSS. The relative RSSI
+ * threshold values are ignored in disconnected state.
+ * @relative_rssi_5g_pref: The amount of RSSI preference in dB that is given to
+ * a 5 GHz BSS over 2.4 GHz BSS while looking for better BSSs in connected
+ * state. A negative value can be passed if 2.4 GHz band should be given
+ * priority to 5 GHz band.
+ * If the current connected BSS is in the 2.4 GHz band, other BSSs in the
+ * 2.4 GHz band to be reported should have better RSSI by @relative_rssi
+ * and other BSSs in the 5 GHz band to be reported should have better RSSI
+ * by (@relative_rssi - @relative_rssi_5g_pref).
+ * If the current connected BSS is in the 5 GHz band, other BSSs in the
+ * 2.4 GHz band to be reported should have better RSSI by
+ * (@relative_rssi + @relative_rssi_5g_pref) and other BSSs in the 5 GHz
+ * band to be reported should have better RSSI by by @relative_rssi.
*/
struct cfg80211_sched_scan_request {
struct cfg80211_ssid *ssids;
@@ -1645,6 +1661,9 @@ struct cfg80211_sched_scan_request {
u8 mac_addr[ETH_ALEN] __aligned(2);
u8 mac_addr_mask[ETH_ALEN] __aligned(2);
+ s8 relative_rssi;
+ s8 relative_rssi_5g_pref;
+
/* internal */
struct wiphy *wiphy;
struct net_device *dev;
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 6b76e3b..fc29bdb 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -1980,6 +1980,17 @@ enum nl80211_commands {
* @NL80211_ATTR_BSSID: The BSSID of the AP. Note that %NL80211_ATTR_MAC is also
* used in various commands/events for specifying the BSSID.
*
+ * @NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI: Relative RSSI threshold by which
+ * other BSSs has to be better than the current connected BSS so that they
+ * get reported to user space. This will give an opportunity to userspace
+ * to consider connecting to other matching BSSs which have better RSSI
+ * than the current connected BSS by using an offloaded operation to avoid
+ * unnecessary wakeups.
+ *
+ * @NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI_5G_PREF: The amount of RSSI preference
+ * to be given to 5 GHz APs over 2.4 GHz APs while searching for better
+ * BSSs than the current connected BSS.
+ *
* @NUM_NL80211_ATTR: total number of nl80211_attrs available
* @NL80211_ATTR_MAX: highest attribute number currently defined
* @__NL80211_ATTR_AFTER_LAST: internal use
@@ -2386,6 +2397,9 @@ enum nl80211_attrs {
NL80211_ATTR_BSSID,
+ NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI,
+ NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI_5G_PREF,
+
/* add attributes here, update the policy in nl80211.c */
__NL80211_ATTR_AFTER_LAST,
@@ -4697,6 +4711,9 @@ enum nl80211_feature_flags {
* configuration (AP/mesh) with VHT rates.
* @NL80211_EXT_FEATURE_FILS_STA: This driver supports Fast Initial Link Setup
* with user space SME (NL80211_CMD_AUTHENTICATE) in station mode.
+ * @NL80211_EXT_FEATURE_SCHED_SCAN_RELATIVE_RSSI: The driver supports sched_scan
+ * for reporting BSSs with better RSSI than the current connected BSS
+ * (%NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI).
*
* @NUM_NL80211_EXT_FEATURES: number of extended features.
* @MAX_NL80211_EXT_FEATURES: highest extended feature index.
@@ -4712,6 +4729,7 @@ enum nl80211_ext_feature_index {
NL80211_EXT_FEATURE_BEACON_RATE_HT,
NL80211_EXT_FEATURE_BEACON_RATE_VHT,
NL80211_EXT_FEATURE_FILS_STA,
+ NL80211_EXT_FEATURE_SCHED_SCAN_RELATIVE_RSSI,
/* add new features before the definition below */
NUM_NL80211_EXT_FEATURES,
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 7762231..549f239 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -405,6 +405,8 @@ enum nl80211_multicast_groups {
[NL80211_ATTR_FILS_NONCES] = { .len = 2 * FILS_NONCE_LEN },
[NL80211_ATTR_MULTICAST_TO_UNICAST_ENABLED] = { .type = NLA_FLAG, },
[NL80211_ATTR_BSSID] = { .len = ETH_ALEN },
+ [NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI] = { .type = NLA_S8 },
+ [NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI_5G_PREF] = { .type = NLA_S8 },
};
/* policy for the key attributes */
@@ -6950,6 +6952,12 @@ static int nl80211_abort_scan(struct sk_buff *skb, struct genl_info *info)
if (!n_plans || n_plans > wiphy->max_sched_scan_plans)
return ERR_PTR(-EINVAL);
+ if (!wiphy_ext_feature_isset(
+ wiphy, NL80211_EXT_FEATURE_SCHED_SCAN_RELATIVE_RSSI) &&
+ (attrs[NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI] ||
+ attrs[NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI_5G_PREF]))
+ return ERR_PTR(-EINVAL);
+
request = kzalloc(sizeof(*request)
+ sizeof(*request->ssids) * n_ssids
+ sizeof(*request->match_sets) * n_match_sets
@@ -7156,6 +7164,14 @@ static int nl80211_abort_scan(struct sk_buff *skb, struct genl_info *info)
request->delay =
nla_get_u32(attrs[NL80211_ATTR_SCHED_SCAN_DELAY]);
+ if (attrs[NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI])
+ request->relative_rssi = nla_get_s8(
+ attrs[NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI]);
+
+ if (attrs[NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI_5G_PREF])
+ request->relative_rssi_5g_pref = nla_get_s8(
+ attrs[NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI_5G_PREF]);
+
err = nl80211_parse_sched_scan_plans(wiphy, n_plans, request, attrs);
if (err)
goto out_free;
@@ -9649,7 +9665,8 @@ static int nl80211_send_wowlan_tcp(struct sk_buff *msg,
return 0;
}
-static int nl80211_send_wowlan_nd(struct sk_buff *msg,
+static int nl80211_send_wowlan_nd(struct wiphy *wiphy,
+ struct sk_buff *msg,
struct cfg80211_sched_scan_request *req)
{
struct nlattr *nd, *freqs, *matches, *match, *scan_plans, *scan_plan;
@@ -9670,6 +9687,14 @@ static int nl80211_send_wowlan_nd(struct sk_buff *msg,
if (nla_put_u32(msg, NL80211_ATTR_SCHED_SCAN_DELAY, req->delay))
return -ENOBUFS;
+ if (wiphy_ext_feature_isset(
+ wiphy, NL80211_EXT_FEATURE_SCHED_SCAN_RELATIVE_RSSI) &&
+ (nla_put_s8(msg, NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI,
+ req->relative_rssi) ||
+ nla_put_s8(msg, NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI_5G_PREF,
+ req->relative_rssi_5g_pref)))
+ return -ENOBUFS;
+
freqs = nla_nest_start(msg, NL80211_ATTR_SCAN_FREQUENCIES);
if (!freqs)
return -ENOBUFS;
@@ -9783,7 +9808,7 @@ static int nl80211_get_wowlan(struct sk_buff *skb, struct genl_info *info)
goto nla_put_failure;
if (nl80211_send_wowlan_nd(
- msg,
+ &rdev->wiphy, msg,
rdev->wiphy.wowlan_config->nd_config))
goto nla_put_failure;
--
1.9.1
