cfg80211: implement APIs for dedicated radar detection HW
authorLorenzo Bianconi <lorenzo@kernel.org>
Sat, 23 Oct 2021 09:10:50 +0000 (11:10 +0200)
committerJohannes Berg <johannes.berg@intel.com>
Fri, 19 Nov 2021 08:38:49 +0000 (09:38 +0100)
If a dedicated (off-channel) radar detection hardware (chain)
is available in the hardware/driver, allow this to be used by
calling the NL80211_CMD_RADAR_DETECT command with a new flag
attribute requesting off-channel radar detection is used.

Offchannel CAC (channel availability check) avoids the CAC
downtime when switching to a radar channel or when turning on
the AP.

Drivers advertise support for this using the new feature flag
NL80211_EXT_FEATURE_RADAR_OFFCHAN.

Tested-by: Evelyn Tsai <evelyn.tsai@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/7468e291ef5d05d692c1738d25b8f778d8ea5c3f.1634979655.git.lorenzo@kernel.org
Link: https://lore.kernel.org/r/1e60e60fef00e14401adae81c3d49f3e5f307537.1634979655.git.lorenzo@kernel.org
Link: https://lore.kernel.org/r/85fa50f57fc3adb2934c8d9ca0be30394de6b7e8.1634979655.git.lorenzo@kernel.org
Link: https://lore.kernel.org/r/4b6c08671ad59aae0ac46fc94c02f31b1610eb72.1634979655.git.lorenzo@kernel.org
Link: https://lore.kernel.org/r/241849ccaf2c228873c6f8495bf87b19159ba458.1634979655.git.lorenzo@kernel.org
[remove offchan_mutex, fix cfg80211_stop_offchan_radar_detection(),
 remove gfp_t argument, fix documentation, fix tracing]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
include/net/cfg80211.h
include/uapi/linux/nl80211.h
net/wireless/core.c
net/wireless/core.h
net/wireless/mlme.c
net/wireless/nl80211.c
net/wireless/rdev-ops.h
net/wireless/trace.h

index 423f97b..db8866d 100644 (file)
@@ -4072,6 +4072,15 @@ struct mgmt_frame_regs {
  * @set_fils_aad: Set FILS AAD data to the AP driver so that the driver can use
  *     those to decrypt (Re)Association Request and encrypt (Re)Association
  *     Response frame.
+ *
+ * @set_radar_offchan: Configure dedicated offchannel chain available for
+ *     radar/CAC detection on some hw. This chain can't be used to transmit
+ *     or receive frames and it is bounded to a running wdev.
+ *     Offchannel radar/CAC detection allows to avoid the CAC downtime
+ *     switching to a different channel during CAC detection on the selected
+ *     radar channel.
+ *     The caller is expected to set chandef pointer to NULL in order to
+ *     disable offchannel CAC/radar detection.
  */
 struct cfg80211_ops {
        int     (*suspend)(struct wiphy *wiphy, struct cfg80211_wowlan *wow);
@@ -4404,6 +4413,8 @@ struct cfg80211_ops {
                                struct cfg80211_color_change_settings *params);
        int     (*set_fils_aad)(struct wiphy *wiphy, struct net_device *dev,
                                struct cfg80211_fils_aad *fils_aad);
+       int     (*set_radar_offchan)(struct wiphy *wiphy,
+                                    struct cfg80211_chan_def *chandef);
 };
 
 /*
@@ -7633,6 +7644,20 @@ void cfg80211_cac_event(struct net_device *netdev,
                        const struct cfg80211_chan_def *chandef,
                        enum nl80211_radar_event event, gfp_t gfp);
 
+/**
+ * cfg80211_offchan_cac_event - Channel Availability Check (CAC) offchan event
+ * @wiphy: the wiphy
+ * @chandef: chandef for the current channel
+ * @event: type of event
+ *
+ * This function is called when a Channel Availability Check (CAC) is finished,
+ * started or aborted by a offchannel dedicated chain.
+ *
+ * Note that this acquires the wiphy lock.
+ */
+void cfg80211_offchan_cac_event(struct wiphy *wiphy,
+                               const struct cfg80211_chan_def *chandef,
+                               enum nl80211_radar_event event);
 
 /**
  * cfg80211_gtk_rekey_notify - notify userspace about driver rekeying
index 61cab81..3e73482 100644 (file)
@@ -2639,6 +2639,13 @@ enum nl80211_commands {
  *     Mandatory parameter for the transmitting interface to enable MBSSID.
  *     Optional for the non-transmitting interfaces.
  *
+ * @NL80211_ATTR_RADAR_OFFCHAN: Configure dedicated offchannel chain available for
+ *     radar/CAC detection on some hw. This chain can't be used to transmit
+ *     or receive frames and it is bounded to a running wdev.
+ *     Offchannel radar/CAC detection allows to avoid the CAC downtime
+ *     switching on a different channel during CAC detection on the selected
+ *     radar channel.
+ *
  * @NUM_NL80211_ATTR: total number of nl80211_attrs available
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
@@ -3145,6 +3152,8 @@ enum nl80211_attrs {
        NL80211_ATTR_MBSSID_CONFIG,
        NL80211_ATTR_MBSSID_ELEMS,
 
+       NL80211_ATTR_RADAR_OFFCHAN,
+
        /* add attributes here, update the policy in nl80211.c */
 
        __NL80211_ATTR_AFTER_LAST,
@@ -6051,6 +6060,9 @@ enum nl80211_feature_flags {
  *     frames. Userspace has to share FILS AAD details to the driver by using
  *     @NL80211_CMD_SET_FILS_AAD.
  *
+ * @NL80211_EXT_FEATURE_RADAR_OFFCHAN: Device supports offchannel radar/CAC
+ *     detection.
+ *
  * @NUM_NL80211_EXT_FEATURES: number of extended features.
  * @MAX_NL80211_EXT_FEATURES: highest extended feature index.
  */
@@ -6117,6 +6129,7 @@ enum nl80211_ext_feature_index {
        NL80211_EXT_FEATURE_PROT_RANGE_NEGO_AND_MEASURE,
        NL80211_EXT_FEATURE_BSS_COLOR,
        NL80211_EXT_FEATURE_FILS_CRYPTO_OFFLOAD,
+       NL80211_EXT_FEATURE_RADAR_OFFCHAN,
 
        /* add new features before the definition below */
        NUM_NL80211_EXT_FEATURES,
index eb297e1..39b2d4a 100644 (file)
@@ -545,6 +545,7 @@ use_default_name:
        INIT_WORK(&rdev->rfkill_block, cfg80211_rfkill_block_work);
        INIT_WORK(&rdev->conn_work, cfg80211_conn_work);
        INIT_WORK(&rdev->event_work, cfg80211_event_work);
+       INIT_DELAYED_WORK(&rdev->offchan_cac_work, cfg80211_offchan_cac_work);
 
        init_waitqueue_head(&rdev->dev_wait);
 
@@ -1207,6 +1208,8 @@ void __cfg80211_leave(struct cfg80211_registered_device *rdev,
 
        cfg80211_pmsr_wdev_down(wdev);
 
+       cfg80211_stop_offchan_radar_detection(wdev);
+
        switch (wdev->iftype) {
        case NL80211_IFTYPE_ADHOC:
                __cfg80211_leave_ibss(rdev, dev, true);
index 1720abf..612d460 100644 (file)
@@ -84,6 +84,10 @@ struct cfg80211_registered_device {
 
        struct delayed_work dfs_update_channels_wk;
 
+       struct wireless_dev *offchan_radar_wdev;
+       struct cfg80211_chan_def offchan_radar_chandef;
+       struct delayed_work offchan_cac_work;
+
        /* netlink port which started critical protocol (0 means not started) */
        u32 crit_proto_nlportid;
 
@@ -491,6 +495,15 @@ cfg80211_chandef_dfs_cac_time(struct wiphy *wiphy,
 
 void cfg80211_sched_dfs_chan_update(struct cfg80211_registered_device *rdev);
 
+int
+cfg80211_start_offchan_radar_detection(struct cfg80211_registered_device *rdev,
+                                      struct wireless_dev *wdev,
+                                      struct cfg80211_chan_def *chandef);
+
+void cfg80211_stop_offchan_radar_detection(struct wireless_dev *wdev);
+
+void cfg80211_offchan_cac_work(struct work_struct *work);
+
 bool cfg80211_any_wiphy_oper_chan(struct wiphy *wiphy,
                                  struct ieee80211_channel *chan);
 
index 783acd2..46f2ec4 100644 (file)
@@ -970,3 +970,116 @@ void cfg80211_cac_event(struct net_device *netdev,
        nl80211_radar_notify(rdev, chandef, event, netdev, gfp);
 }
 EXPORT_SYMBOL(cfg80211_cac_event);
+
+void cfg80211_offchan_cac_work(struct work_struct *work)
+{
+       struct delayed_work *delayed_work = to_delayed_work(work);
+       struct cfg80211_registered_device *rdev;
+
+       rdev = container_of(delayed_work, struct cfg80211_registered_device,
+                           offchan_cac_work);
+       cfg80211_offchan_cac_event(&rdev->wiphy, &rdev->offchan_radar_chandef,
+                                  NL80211_RADAR_CAC_FINISHED);
+}
+
+static void
+__cfg80211_offchan_cac_event(struct cfg80211_registered_device *rdev,
+                            struct wireless_dev *wdev,
+                            const struct cfg80211_chan_def *chandef,
+                            enum nl80211_radar_event event)
+{
+       struct wiphy *wiphy = &rdev->wiphy;
+       struct net_device *netdev;
+
+       lockdep_assert_wiphy(&rdev->wiphy);
+
+       if (event != NL80211_RADAR_CAC_STARTED && !rdev->offchan_radar_wdev)
+               return;
+
+       switch (event) {
+       case NL80211_RADAR_CAC_FINISHED:
+               cfg80211_set_dfs_state(wiphy, chandef, NL80211_DFS_AVAILABLE);
+               memcpy(&rdev->cac_done_chandef, chandef, sizeof(*chandef));
+               queue_work(cfg80211_wq, &rdev->propagate_cac_done_wk);
+               cfg80211_sched_dfs_chan_update(rdev);
+               wdev = rdev->offchan_radar_wdev;
+               rdev->offchan_radar_wdev = NULL;
+               break;
+       case NL80211_RADAR_CAC_ABORTED:
+               cancel_delayed_work(&rdev->offchan_cac_work);
+               wdev = rdev->offchan_radar_wdev;
+               rdev->offchan_radar_wdev = NULL;
+               break;
+       case NL80211_RADAR_CAC_STARTED:
+               WARN_ON(!wdev);
+               rdev->offchan_radar_wdev = wdev;
+               break;
+       default:
+               return;
+       }
+
+       netdev = wdev ? wdev->netdev : NULL;
+       nl80211_radar_notify(rdev, chandef, event, netdev, GFP_KERNEL);
+}
+
+void cfg80211_offchan_cac_event(struct wiphy *wiphy,
+                               const struct cfg80211_chan_def *chandef,
+                               enum nl80211_radar_event event)
+{
+       struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
+
+       wiphy_lock(wiphy);
+       __cfg80211_offchan_cac_event(rdev, NULL, chandef, event);
+       wiphy_unlock(wiphy);
+}
+EXPORT_SYMBOL(cfg80211_offchan_cac_event);
+
+int
+cfg80211_start_offchan_radar_detection(struct cfg80211_registered_device *rdev,
+                                      struct wireless_dev *wdev,
+                                      struct cfg80211_chan_def *chandef)
+{
+       unsigned int cac_time_ms;
+       int err;
+
+       lockdep_assert_wiphy(&rdev->wiphy);
+
+       if (!wiphy_ext_feature_isset(&rdev->wiphy,
+                                    NL80211_EXT_FEATURE_RADAR_OFFCHAN))
+               return -EOPNOTSUPP;
+
+       if (rdev->offchan_radar_wdev)
+               return -EBUSY;
+
+       err = rdev_set_radar_offchan(rdev, chandef);
+       if (err)
+               return err;
+
+       cac_time_ms = cfg80211_chandef_dfs_cac_time(&rdev->wiphy, chandef);
+       if (!cac_time_ms)
+               cac_time_ms = IEEE80211_DFS_MIN_CAC_TIME_MS;
+
+       rdev->offchan_radar_chandef = *chandef;
+       __cfg80211_offchan_cac_event(rdev, wdev, chandef,
+                                    NL80211_RADAR_CAC_STARTED);
+       queue_delayed_work(cfg80211_wq, &rdev->offchan_cac_work,
+                          msecs_to_jiffies(cac_time_ms));
+
+       return 0;
+}
+
+void cfg80211_stop_offchan_radar_detection(struct wireless_dev *wdev)
+{
+       struct wiphy *wiphy = wdev->wiphy;
+       struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
+
+       lockdep_assert_wiphy(wiphy);
+
+       if (wdev != rdev->offchan_radar_wdev)
+               return;
+
+       rdev_set_radar_offchan(rdev, NULL);
+
+       __cfg80211_offchan_cac_event(rdev, NULL, NULL,
+                                    NL80211_RADAR_CAC_ABORTED);
+}
index a27b3b5..83a1ba9 100644 (file)
@@ -776,6 +776,7 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
        [NL80211_ATTR_MBSSID_CONFIG] =
                        NLA_POLICY_NESTED(nl80211_mbssid_config_policy),
        [NL80211_ATTR_MBSSID_ELEMS] = { .type = NLA_NESTED },
+       [NL80211_ATTR_RADAR_OFFCHAN] = { .type = NLA_FLAG },
 };
 
 /* policy for the key attributes */
@@ -9284,12 +9285,6 @@ static int nl80211_start_radar_detection(struct sk_buff *skb,
        if (err)
                return err;
 
-       if (netif_carrier_ok(dev))
-               return -EBUSY;
-
-       if (wdev->cac_started)
-               return -EBUSY;
-
        err = cfg80211_chandef_dfs_required(wiphy, &chandef, wdev->iftype);
        if (err < 0)
                return err;
@@ -9300,6 +9295,16 @@ static int nl80211_start_radar_detection(struct sk_buff *skb,
        if (!cfg80211_chandef_dfs_usable(wiphy, &chandef))
                return -EINVAL;
 
+       if (nla_get_flag(info->attrs[NL80211_ATTR_RADAR_OFFCHAN]))
+               return cfg80211_start_offchan_radar_detection(rdev, wdev,
+                                                             &chandef);
+
+       if (netif_carrier_ok(dev))
+               return -EBUSY;
+
+       if (wdev->cac_started)
+               return -EBUSY;
+
        /* CAC start is offloaded to HW and can't be started manually */
        if (wiphy_ext_feature_isset(wiphy, NL80211_EXT_FEATURE_DFS_OFFLOAD))
                return -EOPNOTSUPP;
index cc1efec..8672b3e 100644 (file)
@@ -1395,4 +1395,21 @@ rdev_set_fils_aad(struct cfg80211_registered_device *rdev,
        return ret;
 }
 
+static inline int
+rdev_set_radar_offchan(struct cfg80211_registered_device *rdev,
+                      struct cfg80211_chan_def *chandef)
+{
+       struct wiphy *wiphy = &rdev->wiphy;
+       int ret;
+
+       if (!rdev->ops->set_radar_offchan)
+               return -EOPNOTSUPP;
+
+       trace_rdev_set_radar_offchan(wiphy, chandef);
+       ret = rdev->ops->set_radar_offchan(wiphy, chandef);
+       trace_rdev_return_int(wiphy, ret);
+
+       return ret;
+}
+
 #endif /* __CFG80211_RDEV_OPS */
index ad6c16a..0b27eaa 100644 (file)
@@ -3674,6 +3674,25 @@ TRACE_EVENT(cfg80211_bss_color_notify,
                  __entry->color_bitmap)
 );
 
+TRACE_EVENT(rdev_set_radar_offchan,
+       TP_PROTO(struct wiphy *wiphy, struct cfg80211_chan_def *chandef),
+
+       TP_ARGS(wiphy, chandef),
+
+       TP_STRUCT__entry(
+               WIPHY_ENTRY
+               CHAN_DEF_ENTRY
+       ),
+
+       TP_fast_assign(
+               WIPHY_ASSIGN;
+               CHAN_DEF_ASSIGN(chandef)
+       ),
+
+       TP_printk(WIPHY_PR_FMT ", " CHAN_DEF_PR_FMT,
+                 WIPHY_PR_ARG, CHAN_DEF_PR_ARG)
+);
+
 #endif /* !__RDEV_OPS_TRACE || TRACE_HEADER_MULTI_READ */
 
 #undef TRACE_INCLUDE_PATH