wifi: nl80211: Add NAN Discovery Window (DW) notification

This notification will be used by the device to inform user space
about upcoming DW. When received, user space will be able to prepare
multicast Service Discovery Frames (SDFs) to be transmitted during the
next DW using %NL80211_CMD_FRAME command on the NAN management interface.
The device/driver will take care to transmit the frames in the correct
timing. This allows to implement a synchronized Discovery Engine (DE)
in user space, if the device doesn't support DE offload.
Note that this notification can be sent before the actual DW starts as
long as the driver/device handles the actual timing of the SDF
transmission.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250908140015.0e1d15031bab.I5b1721e61b63910452b3c5cdcdc1e94cb094d4c9@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index e2f4ca500ea31c9b9aa9567d4c40f44baff9e40d..0c1311d254be12d3b5da59b2a43b30321f2a97cd 100644 (file)
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -3959,6 +3959,8 @@ struct cfg80211_nan_band_config {
  * @scan_period: period (in seconds) between NAN scans.
  * @scan_dwell_time: dwell time (in milliseconds) for NAN scans.
  * @discovery_beacon_interval: interval (in TUs) for discovery beacons.
+ * @enable_dw_notification: flag to enable/disable discovery window
+ *     notifications.
  * @band_cfgs: array of band specific configurations, indexed by
  *     &enum nl80211_band values.
  * @extra_nan_attrs: pointer to additional NAN attributes.
@@ -3973,6 +3975,7 @@ struct cfg80211_nan_conf {
        u16 scan_period;
        u16 scan_dwell_time;
        u8 discovery_beacon_interval;
+       bool enable_dw_notification;
        struct cfg80211_nan_band_config band_cfgs[NUM_NL80211_BANDS];
        const u8 *extra_nan_attrs;
        u16 extra_nan_attrs_len;
@@ -10062,6 +10065,15 @@ void cfg80211_schedule_channels_check(struct wireless_dev *wdev);
  */
 void cfg80211_epcs_changed(struct net_device *netdev, bool enabled);
 
+/**
+ * cfg80211_next_nan_dw_notif - Notify about the next NAN Discovery Window (DW)
+ * @wdev: Pointer to the wireless device structure
+ * @chan: DW channel (6, 44 or 149)
+ * @gfp: Memory allocation flags
+ */
+void cfg80211_next_nan_dw_notif(struct wireless_dev *wdev,
+                               struct ieee80211_channel *chan, gfp_t gfp);
+
 #ifdef CONFIG_CFG80211_DEBUGFS
 /**
  * wiphy_locked_debugfs_read - do a locked read in debugfs

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 20b8202a3d58bff602131cacc9504337e3116eb7..d674608e2635df1f879fa6ea695031df050453a2 100644 (file)
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -1349,6 +1349,15 @@
  *     control EPCS configuration. Used to notify userland on the current state
  *     of EPCS.
  *
+ * @NL80211_CMD_NAN_NEXT_DW_NOTIFICATION: This command is used to notify
+ *     user space about the next NAN Discovery Window (DW). User space may use
+ *     it to prepare frames to be sent in the next DW.
+ *     %NL80211_ATTR_WIPHY_FREQ is used to indicate the frequency of the next
+ *     DW. SDF transmission should be requested with %NL80211_CMD_FRAME and
+ *     the device/driver shall take care of the actual transmission timing.
+ *     This notification is only sent to the NAN interface owning socket
+ *     (see %NL80211_ATTR_SOCKET_OWNER flag).
+ *
  * @NL80211_CMD_MAX: highest used command number
  * @__NL80211_CMD_AFTER_LAST: internal use
  */
@@ -1609,6 +1618,8 @@ enum nl80211_commands {
        NL80211_CMD_ASSOC_MLO_RECONF,
        NL80211_CMD_EPCS_CFG,
 
+       NL80211_CMD_NAN_NEXT_DW_NOTIFICATION,
+
        /* add new commands above here */
 
        /* used to define NL80211_CMD_MAX below */
@@ -7409,6 +7420,10 @@ enum nl80211_nan_band_conf_attributes {
  * @NL80211_NAN_CONF_DISCOVERY_BEACON_INTERVAL: Discovery beacon interval
  *     in TUs. Valid range is 50-200 TUs. If not configured the device default
  *     value is used. This is u8 (optional)
+ * @NL80211_NAN_CONF_NOTIFY_DW: If set, the driver will notify userspace about
+ *     the upcoming discovery window with
+ *     %NL80211_CMD_NAN_NEXT_DW_NOTIFICATION.
+ *     This is a flag attribute.
  * @NUM_NL80211_NAN_CONF_ATTR: Internal.
  * @NL80211_NAN_CONF_ATTR_MAX: Highest NAN configuration attribute.
  *
@@ -7423,6 +7438,7 @@ enum nl80211_nan_conf_attributes {
        NL80211_NAN_CONF_SCAN_PERIOD,
        NL80211_NAN_CONF_SCAN_DWELL_TIME,
        NL80211_NAN_CONF_DISCOVERY_BEACON_INTERVAL,
+       NL80211_NAN_CONF_NOTIFY_DW,
 
        /* keep last */
        NUM_NL80211_NAN_CONF_ATTR,

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 04679acc81352e85c231f072fbbff75c158ba14c..d64145746b65d6691cc049f024f8aa0ae6d5e62e 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -547,6 +547,7 @@ nl80211_nan_conf_policy[NL80211_NAN_CONF_ATTR_MAX + 1] = {
        [NL80211_NAN_CONF_SCAN_DWELL_TIME] = NLA_POLICY_RANGE(NLA_U16, 50, 512),
        [NL80211_NAN_CONF_DISCOVERY_BEACON_INTERVAL] =
                NLA_POLICY_RANGE(NLA_U8, 50, 200),
+       [NL80211_NAN_CONF_NOTIFY_DW] = { .type = NLA_FLAG },
 };
 
 static const struct netlink_range_validation nl80211_punct_bitmap_range = {
@@ -15627,6 +15628,11 @@ static int nl80211_parse_nan_conf(struct wiphy *wiphy,
        if (attrs[NL80211_NAN_CONF_DISCOVERY_BEACON_INTERVAL])
                conf->discovery_beacon_interval =
                        nla_get_u8(attrs[NL80211_NAN_CONF_DISCOVERY_BEACON_INTERVAL]);
+
+       if (attrs[NL80211_NAN_CONF_NOTIFY_DW])
+               conf->enable_dw_notification =
+                       nla_get_flag(attrs[NL80211_NAN_CONF_NOTIFY_DW]);
+
 out:
        if (!conf->band_cfgs[NL80211_BAND_5GHZ].chan &&
            (!conf->bands || conf->bands & BIT(NL80211_BAND_5GHZ))) {
@@ -21764,6 +21770,45 @@ void cfg80211_epcs_changed(struct net_device *netdev, bool enabled)
 }
 EXPORT_SYMBOL(cfg80211_epcs_changed);
 
+void cfg80211_next_nan_dw_notif(struct wireless_dev *wdev,
+                               struct ieee80211_channel *chan, gfp_t gfp)
+{
+       struct wiphy *wiphy = wdev->wiphy;
+       struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
+       struct sk_buff *msg;
+       void *hdr;
+
+       trace_cfg80211_next_nan_dw_notif(wdev, chan);
+
+       if (!wdev->owner_nlportid)
+               return;
+
+       msg = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
+       if (!msg)
+               return;
+
+       hdr = nl80211hdr_put(msg, 0, 0, 0,
+                            NL80211_CMD_NAN_NEXT_DW_NOTIFICATION);
+       if (!hdr)
+               goto nla_put_failure;
+
+       if (nla_put_u32(msg, NL80211_ATTR_WIPHY, rdev->wiphy_idx) ||
+           nla_put_u64_64bit(msg, NL80211_ATTR_WDEV, wdev_id(wdev),
+                             NL80211_ATTR_PAD) ||
+           nla_put_u32(msg, NL80211_ATTR_WIPHY_FREQ, chan->center_freq))
+               goto nla_put_failure;
+
+       genlmsg_end(msg, hdr);
+
+       genlmsg_unicast(wiphy_net(wiphy), msg, wdev->owner_nlportid);
+
+       return;
+
+ nla_put_failure:
+       nlmsg_free(msg);
+}
+EXPORT_SYMBOL(cfg80211_next_nan_dw_notif);
+
 /* initialisation/exit functions */
 
 int __init nl80211_init(void)

diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index 9b6074155d59daf403f92efaff6f2d528d1181ce..ff47e9bffd4fb5fb10deffa965102a017d719014 100644 (file)
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -4166,6 +4166,22 @@ TRACE_EVENT(cfg80211_epcs_changed,
                  WDEV_PR_ARG, __entry->enabled)
 );
 
+TRACE_EVENT(cfg80211_next_nan_dw_notif,
+       TP_PROTO(struct wireless_dev *wdev,
+                struct ieee80211_channel *chan),
+       TP_ARGS(wdev, chan),
+       TP_STRUCT__entry(
+               WDEV_ENTRY
+               CHAN_ENTRY
+       ),
+       TP_fast_assign(
+               WDEV_ASSIGN;
+               CHAN_ASSIGN(chan);
+       ),
+       TP_printk(WDEV_PR_FMT " " CHAN_PR_FMT,
+                 WDEV_PR_ARG, CHAN_PR_ARG)
+);
+
 #endif /* !__RDEV_OPS_TRACE || TRACE_HEADER_MULTI_READ */
 
 #undef TRACE_INCLUDE_PATH