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 a significantly better RSSI than the current
connected BSS.
Signed-off-by: vamsi krishna <vamsin@xxxxxxxxxxxxxxxx>
Signed-off-by: Jouni Malinen <jouni@xxxxxxxxxxxxxxxx>
---
include/net/cfg80211.h | 17 +++++++++++++++++
include/uapi/linux/nl80211.h | 17 +++++++++++++++++
net/wireless/nl80211.c | 32 ++++++++++++++++++++++++++++++--
3 files changed, 64 insertions(+), 2 deletions(-)
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index ef42749..c62c42a 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1626,6 +1626,20 @@ 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 to restrict scan result reporting in
+ * connected state to cases where a matching BSS is determined to have a
+ * significantly better RSSI than the current connected BSS.
+ * @relative_rssi_5g_pref: The amount of RSSI preference that is given to a
+ * 5 GHz BSS over 2.4 GHz BSS while looking for better BSSs in connected
+ * state.
+ * 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 +1659,9 @@ struct cfg80211_sched_scan_request {
u8 mac_addr[ETH_ALEN] __aligned(2);
u8 mac_addr_mask[ETH_ALEN] __aligned(2);
+ int relative_rssi;
+ int 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 984a35ac..34b16a4 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -1981,6 +1981,16 @@ enum nl80211_commands {
* %NL80211_ATTR_MAC has also been 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.
+ *
+ * @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
@@ -2387,6 +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,
@@ -4698,6 +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_BETTER_BSS: 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.
@@ -4713,6 +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_BETTER_BSS,
/* add new features before the definition below */
NUM_NL80211_EXT_FEATURES,
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 8db5cb1..af018a5 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_U32 },
+ [NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI_5G_PREF] = { .type = NLA_U32 },
};
/* policy for the key attributes */
@@ -6856,6 +6858,7 @@ static int nl80211_abort_scan(struct sk_buff *skb, struct genl_info *info)
size_t ie_len;
struct nlattr *tb[NL80211_SCHED_SCAN_MATCH_ATTR_MAX + 1];
s32 default_match_rssi = NL80211_SCAN_RSSI_THOLD_OFF;
+ int bbr;
if (!is_valid_ie_attr(attrs[NL80211_ATTR_IE]))
return ERR_PTR(-EINVAL);
@@ -6950,6 +6953,13 @@ 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);
+ bbr = wiphy_ext_feature_isset(
+ wiphy, NL80211_EXT_FEATURE_SCHED_SCAN_BETTER_BSS);
+ if (!bbr &&
+ (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 +7166,14 @@ 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_s32(
+ attrs[NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI]);
+
+ if (attrs[NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI_5G_PREF])
+ request->relative_rssi_5g_pref = nla_get_s32(
+ 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 +9667,8 @@ 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 +9689,15 @@ 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_BETTER_BSS) &&
+ (nla_put_u32(msg, NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI,
+ req->relative_rssi) ||
+ nla_put_u32(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 +9811,7 @@ 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
