Hi,
I'm looking for a way to enable userspace to receive RSSI updates
without polling and waking up only as often as needed, for use in a
wifi daemon oriented for low power. Userspace tends to display a wifi
icon with the rssi shown as a number of "signal bars", usually 4, 5,
or 6. This patch adds an nl80211 CQM command and an event to report
exactly this information and nothing more. The
NL80211_ATTR_CQM_ROUNDED_RSSI_STEPS attribute is used to set how many
bars are used and assumes -100dbm to be the minimum. It's not very
flexible. It may be better, for example to accept a list of thresholds
and a hysteresis value to be used in the same way as with the
NL80211_ATTR_CQM_RSSI_THOLD attribute, or even modify it to allow
multiple thresholds to be given but that would need a problematic
driver api change. What would be the best way to do that?
The assumption is that you can't simulate the same behavior with just
the current NL80211_ATTR_CQM_RSSI_THOLD attribute.
Best regards
---
include/net/cfg80211.h | 21 ++++++++++++++++++
include/net/mac80211.h | 4 ++++
include/uapi/linux/nl80211.h | 10 +++++++++
net/mac80211/cfg.c | 18 +++++++++++++++
net/mac80211/ieee80211_i.h | 11 ++++++++--
net/mac80211/mlme.c | 27 +++++++++++++++++++++++
net/wireless/nl80211.c | 52 ++++++++++++++++++++++++++++++++++++++++++++
net/wireless/rdev-ops.h | 11 ++++++++++
net/wireless/trace.h | 33 ++++++++++++++++++++++++++++
9 files changed, 185 insertions(+), 2 deletions(-)
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index bd19faa..3487b3f 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2606,6 +2606,10 @@ struct cfg80211_nan_func {
* disabled.)
* @set_cqm_txe_config: Configure connection quality monitor TX error
* thresholds.
+ * @set_cqm_rssi_steps: Configure number of RSSI levels for the connection
+ * quality monitor to use in deciding when to send rounded RSSI change
+ * events. After configuration, the driver should (soon) send an event
+ * indicating the current level out of the number of levels set.
* @sched_scan_start: Tell the driver to start a scheduled scan.
* @sched_scan_stop: Tell the driver to stop an ongoing scheduled scan. This
* call must stop the scheduled scan and be ready for starting a new one
@@ -2891,6 +2895,9 @@ struct cfg80211_ops {
struct net_device *dev,
u32 rate, u32 pkts, u32 intvl);
+ int (*set_cqm_rssi_steps)(struct wiphy *wiphy,
+ struct net_device *dev, u32 steps);
+
void (*mgmt_frame_register)(struct wiphy *wiphy,
struct wireless_dev *wdev,
u16 frame_type, bool reg);
@@ -5213,6 +5220,20 @@ void cfg80211_cqm_txe_notify(struct net_device *dev, const u8 *peer,
void cfg80211_cqm_beacon_loss_notify(struct net_device *dev, gfp_t gfp);
/**
+ * cfg80211_cqm_rounded_rssi_notify - connection quality monitoring rssi event
+ * @dev: network device
+ * @signal_level: the signal level in the range of 0 to (steps - 1)
+ * @gfp: context flags
+ *
+ * This function is called when the RSSI level, rounded to the resolution
+ * set by cfg80211_ops::set_cqm_rssi_steps, has changed. In other words
+ * the RSSI value has gone from one of the equally sized intervals, covering
+ * the range of -100dBm to 0, to another.
+ */
+void cfg80211_cqm_rounded_rssi_notify(struct net_device *dev,
+ u32 signal_level, gfp_t gfp);
+
+/**
* cfg80211_radar_event - radar detection event
* @wiphy: the wiphy
* @chandef: chandef for the current channel
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index a810dfc..5fbe275 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -503,6 +503,9 @@ struct ieee80211_mu_group_data {
* cause an event to be sent indicating where the current value is in
* relation to the newly configured threshold.
* @cqm_rssi_hyst: Connection quality monitor RSSI hysteresis
+ * @cqm_rssi_steps: Connection quality monitor's number of RSSI levels to
+ * use when sending rounded RSSI change events. A zero value implies this
+ * event is disabled.
* @arp_addr_list: List of IPv4 addresses for hardware ARP filtering. The
* may filter ARP queries targeted for other addresses than listed here.
* The driver must allow ARP queries targeted for all address listed here
@@ -554,6 +557,7 @@ struct ieee80211_bss_conf {
u16 ht_operation_mode;
s32 cqm_rssi_thold;
u32 cqm_rssi_hyst;
+ u32 cqm_rssi_steps;
struct cfg80211_chan_def chandef;
struct ieee80211_mu_group_data mu_group;
__be32 arp_addr_list[IEEE80211_BSS_ARP_ADDR_LIST_LEN];
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 56368e9..a2c8817 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -3859,6 +3859,14 @@ enum nl80211_ps_state {
* %NL80211_CMD_NOTIFY_CQM. Set to 0 to turn off TX error reporting.
* @NL80211_ATTR_CQM_BEACON_LOSS_EVENT: flag attribute that's set in a beacon
* loss event
+ * @NL80211_ATTR_CQM_ROUNDED_RSSI_STEPS: number of evenly spaced RSSI ranges
+ * to be distinguished between -100 dBm and 0. %NL80211_CMD_NOTIFY_CQM
+ * events will be sent when the RSSI value crosses from one range of
+ * values to another. Set to 0 to disable
+ * %NL80211_ATTR_CQM_ROUNDED_RSSI_EVENT reporting.
+ * @NL80211_ATTR_CQM_ROUNDED_RSSI_EVENT: the RSSI level with range reduced to
+ * 0 to steps - 1 as configured in %NL80211_ATTR_CQM_ROUNDED_RSSI_STEPS
+ * value.
* @__NL80211_ATTR_CQM_AFTER_LAST: internal
* @NL80211_ATTR_CQM_MAX: highest key attribute
*/
@@ -3872,6 +3880,8 @@ enum nl80211_attr_cqm {
NL80211_ATTR_CQM_TXE_PKTS,
NL80211_ATTR_CQM_TXE_INTVL,
NL80211_ATTR_CQM_BEACON_LOSS_EVENT,
+ NL80211_ATTR_CQM_ROUNDED_RSSI_STEPS,
+ NL80211_ATTR_CQM_ROUNDED_RSSI_EVENT,
/* keep last */
__NL80211_ATTR_CQM_AFTER_LAST,
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index fd6541f..73550a7 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2657,6 +2657,23 @@ static int ieee80211_set_cqm_rssi_config(struct wiphy *wiphy,
return 0;
}
+static int ieee80211_set_cqm_rssi_steps(struct wiphy *wiphy,
+ struct net_device *dev,
+ u32 steps)
+{
+ struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+ struct ieee80211_vif *vif = &sdata->vif;
+ struct ieee80211_bss_conf *bss_conf = &vif->bss_conf;
+
+ if (sdata->vif.driver_flags & IEEE80211_VIF_BEACON_FILTER)
+ return -EOPNOTSUPP;
+
+ bss_conf->cqm_rssi_steps = steps;
+ sdata->u.mgd.last_cqm_event_rounded_rssi = 0;
+
+ return 0;
+}
+
static int ieee80211_set_bitrate_mask(struct wiphy *wiphy,
struct net_device *dev,
const u8 *addr,
@@ -3645,6 +3662,7 @@ const struct cfg80211_ops mac80211_config_ops = {
.mgmt_tx = ieee80211_mgmt_tx,
.mgmt_tx_cancel_wait = ieee80211_mgmt_tx_cancel_wait,
.set_cqm_rssi_config = ieee80211_set_cqm_rssi_config,
+ .set_cqm_rssi_steps = ieee80211_set_cqm_rssi_steps,
.mgmt_frame_register = ieee80211_mgmt_frame_register,
.set_antenna = ieee80211_set_antenna,
.get_antenna = ieee80211_get_antenna,
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 34c2add..1c04c21 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -507,12 +507,19 @@ struct ieee80211_if_managed {
/*
* Last Beacon frame signal strength average (ave_beacon_signal / 16)
- * that triggered a cqm event. 0 indicates that no event has been
- * generated for the current association.
+ * that triggered a cqm RSSI threshold-crossed event. 0 indicates
+ * that no event has been generated for the current association.
*/
int last_cqm_event_signal;
/*
+ * Last Beacon frame signal strength average (ave_beacon_signal / 16)
+ * that triggered a cqm rounded RSSI level event. 0 indicates that no
+ * event has been generated for the current association.
+ */
+ int last_cqm_event_rounded_rssi;
+
+ /*
* State variables for keeping track of RSSI of the AP currently
* connected to and informing driver when RSSI has gone
* below/above a certain threshold.
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 7486f2d..a87422b 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -3253,6 +3253,14 @@ static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
ieee80211_reset_ap_probe(sdata);
}
+static void ieee80211_cqm_rounded_rssi_notify(struct ieee80211_vif *vif,
+ u32 signal_level, gfp_t gfp)
+{
+ struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+
+ cfg80211_cqm_rounded_rssi_notify(sdata->dev, signal_level, gfp);
+}
+
/*
* This is the canonical list of information elements we care about,
* the filter code also gives us all changes to the Microsoft OUI
@@ -3416,6 +3424,25 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
}
}
+ if (bss_conf->cqm_rssi_steps &&
+ ifmgd->count_beacon_signal >= IEEE80211_SIGNAL_AVE_MIN_COUNT) {
+ int sig = -ewma_beacon_signal_read(&ifmgd->ave_beacon_signal);
+ int last_event = ifmgd->last_cqm_event_rounded_rssi;
+ int steps = bss_conf->cqm_rssi_steps;
+ int last_level = (last_event + 100) * steps / 100;
+ int cur_level = (sig + 100) * steps / 100;
+ /* Use a threshold of 1/4th of the step size (100dBm / steps) */
+ int thold = 25 / steps;
+
+ if (last_event == 0 ||
+ (cur_level < last_level && sig < last_event - thold) ||
+ (cur_level > last_level && sig > last_event + thold)) {
+ ifmgd->last_cqm_event_rounded_rssi = sig;
+ ieee80211_cqm_rounded_rssi_notify(
+ &sdata->vif, cur_level, GFP_KERNEL);
+ }
+ }
+
if (ifmgd->flags & IEEE80211_STA_CONNECTION_POLL) {
mlme_dbg_ratelimited(sdata,
"cancelling AP probe due to a received beacon\n");
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index c510810..5bfc853 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -9278,6 +9278,8 @@ nl80211_attr_cqm_policy[NL80211_ATTR_CQM_MAX + 1] = {
[NL80211_ATTR_CQM_TXE_RATE] = { .type = NLA_U32 },
[NL80211_ATTR_CQM_TXE_PKTS] = { .type = NLA_U32 },
[NL80211_ATTR_CQM_TXE_INTVL] = { .type = NLA_U32 },
+ [NL80211_ATTR_CQM_ROUNDED_RSSI_STEPS] = { .type = NLA_U32 },
+ [NL80211_ATTR_CQM_ROUNDED_RSSI_EVENT] = { .type = NLA_U32 },
};
static int nl80211_set_cqm_txe(struct genl_info *info,
@@ -9324,6 +9326,25 @@ static int nl80211_set_cqm_rssi(struct genl_info *info,
return rdev_set_cqm_rssi_config(rdev, dev, threshold, hysteresis);
}
+static int nl80211_set_cqm_rounded_rssi_steps(struct genl_info *info, u32 steps)
+{
+ struct cfg80211_registered_device *rdev = info->user_ptr[0];
+ struct net_device *dev = info->user_ptr[1];
+ struct wireless_dev *wdev = dev->ieee80211_ptr;
+
+ if (steps == 1)
+ return -EINVAL;
+
+ if (!rdev->ops->set_cqm_rssi_steps)
+ return -EOPNOTSUPP;
+
+ if (wdev->iftype != NL80211_IFTYPE_STATION &&
+ wdev->iftype != NL80211_IFTYPE_P2P_CLIENT)
+ return -EOPNOTSUPP;
+
+ return rdev_set_cqm_rssi_steps(rdev, dev, steps);
+}
+
static int nl80211_set_cqm(struct sk_buff *skb, struct genl_info *info)
{
struct nlattr *attrs[NL80211_ATTR_CQM_MAX + 1];
@@ -9357,6 +9378,13 @@ static int nl80211_set_cqm(struct sk_buff *skb, struct genl_info *info)
return nl80211_set_cqm_txe(info, rate, pkts, intvl);
}
+ if (attrs[NL80211_ATTR_CQM_ROUNDED_RSSI_STEPS]) {
+ u32 steps = nla_get_u32(
+ attrs[NL80211_ATTR_CQM_ROUNDED_RSSI_STEPS]);
+
+ return nl80211_set_cqm_rounded_rssi_steps(info, steps);
+ }
+
return -EINVAL;
}
@@ -13832,6 +13860,30 @@ void cfg80211_cqm_beacon_loss_notify(struct net_device *dev, gfp_t gfp)
}
EXPORT_SYMBOL(cfg80211_cqm_beacon_loss_notify);
+void cfg80211_cqm_rounded_rssi_notify(struct net_device *dev,
+ u32 signal_level, gfp_t gfp)
+{
+ struct sk_buff *msg;
+
+ trace_cfg80211_cqm_rounded_rssi_notify(dev, signal_level);
+
+ msg = cfg80211_prepare_cqm(dev, NULL, gfp);
+ if (!msg)
+ return;
+
+ if (nla_put_u32(msg, NL80211_ATTR_CQM_ROUNDED_RSSI_EVENT,
+ signal_level))
+ goto nla_put_failure;
+
+ cfg80211_send_cqm(msg, gfp);
+
+ return;
+
+ nla_put_failure:
+ nlmsg_free(msg);
+}
+EXPORT_SYMBOL(cfg80211_cqm_rounded_rssi_notify);
+
static void nl80211_gtk_rekey_notify(struct cfg80211_registered_device *rdev,
struct net_device *netdev, const u8 *bssid,
const u8 *replay_ctr, gfp_t gfp)
diff --git a/net/wireless/rdev-ops.h b/net/wireless/rdev-ops.h
index 11cf83c..3521a2f 100644
--- a/net/wireless/rdev-ops.h
+++ b/net/wireless/rdev-ops.h
@@ -737,6 +737,17 @@ rdev_set_cqm_txe_config(struct cfg80211_registered_device *rdev,
return ret;
}
+static inline int
+rdev_set_cqm_rssi_steps(struct cfg80211_registered_device *rdev,
+ struct net_device *dev, u32 steps)
+{
+ int ret;
+ trace_rdev_set_cqm_rssi_steps(&rdev->wiphy, dev, steps);
+ ret = rdev->ops->set_cqm_rssi_steps(&rdev->wiphy, dev, steps);
+ trace_rdev_return_int(&rdev->wiphy, ret);
+ return ret;
+}
+
static inline void
rdev_mgmt_frame_register(struct cfg80211_registered_device *rdev,
struct wireless_dev *wdev, u16 frame_type, bool reg)
diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index a3d0a91..dbc2450 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -1327,6 +1327,24 @@ TRACE_EVENT(rdev_set_cqm_txe_config,
__entry->intvl)
);
+TRACE_EVENT(rdev_set_cqm_rssi_steps,
+ TP_PROTO(struct wiphy *wiphy,
+ struct net_device *netdev, u32 steps),
+ TP_ARGS(wiphy, netdev, steps),
+ TP_STRUCT__entry(
+ WIPHY_ENTRY
+ NETDEV_ENTRY
+ __field(u32, steps)
+ ),
+ TP_fast_assign(
+ WIPHY_ASSIGN;
+ NETDEV_ASSIGN;
+ __entry->steps = steps;
+ ),
+ TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", steps: %u ",
+ WIPHY_PR_ARG, NETDEV_PR_ARG, __entry->steps)
+);
+
TRACE_EVENT(rdev_disconnect,
TP_PROTO(struct wiphy *wiphy, struct net_device *netdev,
u16 reason_code),
@@ -2486,6 +2504,21 @@ TRACE_EVENT(cfg80211_cqm_rssi_notify,
NETDEV_PR_ARG, __entry->rssi_event)
);
+TRACE_EVENT(cfg80211_cqm_rounded_rssi_notify,
+ TP_PROTO(struct net_device *netdev, u32 signal_level),
+ TP_ARGS(netdev, signal_level),
+ TP_STRUCT__entry(
+ NETDEV_ENTRY
+ __field(u32 signal_level)
+ ),
+ TP_fast_assign(
+ NETDEV_ASSIGN;
+ __entry->signal_level = signal_level;
+ ),
+ TP_printk(NETDEV_PR_FMT ", signal_level: %d",
+ NETDEV_PR_ARG, __entry->signal_level)
+);
+
TRACE_EVENT(cfg80211_reg_can_beacon,
TP_PROTO(struct wiphy *wiphy, struct cfg80211_chan_def *chandef,
enum nl80211_iftype iftype, bool check_no_ir),
--
2.7.4
