mac80211: allow scanning operating on DFS channels

Only for multi-radio configurations where the scan would not affect the radio
running DFS detection

Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/package/kernel/mac80211/patches/subsys/350-mac80211-allow-scanning-while-on-radar-channel.patch b/package/kernel/mac80211/patches/subsys/350-mac80211-allow-scanning-while-on-radar-channel.patch
new file mode 100644 (file)
index 0000000..d469955
--- /dev/null
+++ b/package/kernel/mac80211/patches/subsys/350-mac80211-allow-scanning-while-on-radar-channel.patch
@@ -0,0 +1,372 @@
+--- a/net/mac80211/cfg.c
++++ b/net/mac80211/cfg.c
+@@ -3473,6 +3473,27 @@ static int ieee80211_set_bitrate_mask(st
+       return 0;
+ }
+ 
++bool ieee80211_scanning_busy(struct ieee80211_local *local,
++                           struct cfg80211_chan_def *chandef)
++{
++      struct cfg80211_scan_request *scan_req;
++      struct wiphy *wiphy = local->hw.wiphy;
++      u32 mask;
++
++      if (list_empty(&local->roc_list) && !local->scanning)
++              return false;
++
++      if (!wiphy->n_radio)
++              return true;
++
++      mask = ieee80211_offchannel_radio_mask(local);
++      scan_req = wiphy_dereference(wiphy, local->scan_req);
++      if (scan_req)
++              mask |= ieee80211_scan_req_radio_mask(local, scan_req);
++
++      return mask & ieee80211_chandef_radio_mask(local, chandef);
++}
++
+ static int ieee80211_start_radar_detection(struct wiphy *wiphy,
+                                          struct net_device *dev,
+                                          struct cfg80211_chan_def *chandef,
+@@ -3486,7 +3507,7 @@ static int ieee80211_start_radar_detecti
+ 
+       lockdep_assert_wiphy(local->hw.wiphy);
+ 
+-      if (!list_empty(&local->roc_list) || local->scanning)
++      if (ieee80211_scanning_busy(local, chandef))
+               return -EBUSY;
+ 
+       link_data = sdata_dereference(sdata->link[link_id], sdata);
+@@ -3978,7 +3999,7 @@ __ieee80211_channel_switch(struct wiphy
+ 
+       lockdep_assert_wiphy(local->hw.wiphy);
+ 
+-      if (!list_empty(&local->roc_list) || local->scanning)
++      if (ieee80211_scanning_busy(local, &params->chandef))
+               return -EBUSY;
+ 
+       if (sdata->wdev.links[link_id].cac_started)
+--- a/net/mac80211/chan.c
++++ b/net/mac80211/chan.c
+@@ -629,14 +629,24 @@ ieee80211_find_chanctx(struct ieee80211_
+       return NULL;
+ }
+ 
+-bool ieee80211_is_radar_required(struct ieee80211_local *local)
++bool ieee80211_is_radar_required(struct ieee80211_local *local, u32 radio_mask)
+ {
++      struct ieee80211_chanctx_conf *conf;
+       struct ieee80211_link_data *link;
+ 
+       lockdep_assert_wiphy(local->hw.wiphy);
+ 
+       for_each_sdata_link(local, link) {
+-              if (link->radar_required)
++              if (!link->radar_required)
++                      continue;
++              if (!local->hw.wiphy->n_radio)
++                      return true;
++
++              conf = wiphy_dereference(local->hw.wiphy, link->conf->chanctx_conf);
++              if (!conf)
++                      continue;
++
++              if (conf->radio_idx >= 0 && (radio_mask & BIT(conf->radio_idx)))
+                       return true;
+       }
+ 
+--- a/net/mac80211/ieee80211_i.h
++++ b/net/mac80211/ieee80211_i.h
+@@ -1947,6 +1947,12 @@ int ieee80211_mesh_finish_csa(struct iee
+                             u64 *changed);
+ 
+ /* scan/BSS handling */
++u32 ieee80211_scan_req_radio_mask(struct ieee80211_local *local,
++                                struct cfg80211_scan_request *req);
++bool ieee80211_scanning_busy(struct ieee80211_local *local,
++                           struct cfg80211_chan_def *chandef);
++u32 ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata,
++                         u32 radio_mask);
+ void ieee80211_scan_work(struct wiphy *wiphy, struct wiphy_work *work);
+ int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
+                               const u8 *ssid, u8 ssid_len,
+@@ -1985,6 +1991,7 @@ void ieee80211_sched_scan_stopped_work(s
+ /* off-channel/mgmt-tx */
+ void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local);
+ void ieee80211_offchannel_return(struct ieee80211_local *local);
++u32 ieee80211_offchannel_radio_mask(struct ieee80211_local *local);
+ void ieee80211_roc_setup(struct ieee80211_local *local);
+ void ieee80211_start_next_roc(struct ieee80211_local *local);
+ void ieee80211_reconfig_roc(struct ieee80211_local *local);
+@@ -2629,6 +2636,8 @@ bool ieee80211_chandef_s1g_oper(const st
+                               struct cfg80211_chan_def *chandef);
+ void ieee80211_chandef_downgrade(struct cfg80211_chan_def *chandef,
+                                struct ieee80211_conn_settings *conn);
++u32 ieee80211_chandef_radio_mask(struct ieee80211_local *local,
++                               struct cfg80211_chan_def *chandef);
+ static inline void
+ ieee80211_chanreq_downgrade(struct ieee80211_chan_req *chanreq,
+                           struct ieee80211_conn_settings *conn)
+@@ -2685,7 +2694,7 @@ void ieee80211_recalc_chanctx_min_def(st
+                                     struct ieee80211_chanctx *ctx,
+                                     struct ieee80211_link_data *rsvd_for,
+                                     bool check_reserved);
+-bool ieee80211_is_radar_required(struct ieee80211_local *local);
++bool ieee80211_is_radar_required(struct ieee80211_local *local, u32 radio_mask);
+ 
+ void ieee80211_dfs_cac_timer_work(struct wiphy *wiphy, struct wiphy_work *work);
+ void ieee80211_dfs_cac_cancel(struct ieee80211_local *local,
+--- a/net/mac80211/offchannel.c
++++ b/net/mac80211/offchannel.c
+@@ -168,6 +168,35 @@ void ieee80211_offchannel_return(struct
+                                       false);
+ }
+ 
++u32 ieee80211_offchannel_radio_mask(struct ieee80211_local *local)
++{
++      const struct wiphy_radio *radio;
++      struct ieee80211_roc_work *roc;
++      u32 mask = 0;
++      int r;
++
++      for (r = 0; r < local->hw.wiphy->n_radio; r++) {
++              radio = &local->hw.wiphy->radio[r];
++
++              list_for_each_entry(roc, &local->roc_list, list) {
++                      struct cfg80211_chan_def chandef = {};
++
++                      if (!roc->started)
++                              continue;
++
++                      cfg80211_chandef_create(&chandef, roc->chan,
++                                              NL80211_CHAN_NO_HT);
++                      if (!cfg80211_radio_chandef_valid(radio, &chandef))
++                              continue;
++
++                      mask |= BIT(r);
++                      break;
++              }
++      }
++
++      return mask;
++}
++
+ static void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
+ {
+       /* was never transmitted */
+@@ -566,7 +595,9 @@ static int ieee80211_start_roc_work(stru
+                                   enum ieee80211_roc_type type)
+ {
+       struct ieee80211_roc_work *roc, *tmp;
++      struct cfg80211_chan_def chandef = {};
+       bool queued = false, combine_started = true;
++      u32 radio_mask;
+       int ret;
+ 
+       lockdep_assert_wiphy(local->hw.wiphy);
+@@ -578,6 +609,12 @@ static int ieee80211_start_roc_work(stru
+       if (!local->emulate_chanctx && !local->ops->remain_on_channel)
+               return -EOPNOTSUPP;
+ 
++      cfg80211_chandef_create(&chandef, channel, NL80211_CHAN_NO_HT);
++      radio_mask = ieee80211_chandef_radio_mask(local, &chandef);
++      if (!ieee80211_can_leave_ch(sdata, radio_mask) &&
++          !ieee80211_scanning_busy(local, &chandef))
++              return -EBUSY;
++
+       roc = kzalloc(sizeof(*roc), GFP_KERNEL);
+       if (!roc)
+               return -ENOMEM;
+@@ -613,8 +650,7 @@ static int ieee80211_start_roc_work(stru
+       }
+ 
+       /* if there's no need to queue, handle it immediately */
+-      if (list_empty(&local->roc_list) &&
+-          !local->scanning && !ieee80211_is_radar_required(local)) {
++      if (list_empty(&local->roc_list) && !local->scanning) {
+               /* if not HW assist, just queue & schedule work */
+               if (!local->ops->remain_on_channel) {
+                       list_add_tail(&roc->list, &local->roc_list);
+--- a/net/mac80211/scan.c
++++ b/net/mac80211/scan.c
+@@ -571,36 +571,83 @@ static int ieee80211_start_sw_scan(struc
+       return 0;
+ }
+ 
+-static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
++u32 ieee80211_scan_req_radio_mask(struct ieee80211_local *local,
++                                struct cfg80211_scan_request *req)
++{
++      const struct wiphy_radio *radio;
++      u32 mask = 0;
++      int i, r;
++
++      for (r = 0; r < local->hw.wiphy->n_radio; r++) {
++              radio = &local->hw.wiphy->radio[r];
++
++              for (i = 0; i < req->n_channels; i++) {
++                      struct cfg80211_chan_def chandef = {};
++
++                      chandef.chan = req->channels[i];
++                      cfg80211_chandef_create(&chandef, req->channels[i],
++                                              NL80211_CHAN_NO_HT);
++                      if (!cfg80211_radio_chandef_valid(radio, &chandef))
++                              continue;
++
++                      mask |= BIT(r);
++                      break;
++              }
++      }
++
++      return mask;
++}
++
++u32 ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata,
++                         u32 radio_mask)
+ {
+       struct ieee80211_local *local = sdata->local;
+       struct ieee80211_sub_if_data *sdata_iter;
++      struct wiphy *wiphy = local->hw.wiphy;
++      struct ieee80211_chanctx_conf *conf;
++      struct ieee80211_link_data *link;
+       unsigned int link_id;
+ 
+       lockdep_assert_wiphy(local->hw.wiphy);
+ 
+-      if (!ieee80211_is_radar_required(local))
++      if (!ieee80211_is_radar_required(local, radio_mask))
+               return true;
+ 
+       if (!regulatory_pre_cac_allowed(local->hw.wiphy))
+               return false;
+ 
+       list_for_each_entry(sdata_iter, &local->interfaces, list) {
+-              for_each_valid_link(&sdata_iter->wdev, link_id)
+-                      if (sdata_iter->wdev.links[link_id].cac_started)
++              for_each_valid_link(&sdata_iter->wdev, link_id) {
++                      if (!sdata_iter->wdev.links[link_id].cac_started)
++                              continue;
++
++                      if (!wiphy->n_radio)
+                               return false;
++
++                      link = sdata_dereference(sdata->link[link_id], sdata);
++                      if (!link)
++                              continue;
++
++                      conf = wiphy_dereference(wiphy, link->conf->chanctx_conf);
++                      if (!conf)
++                              continue;
++
++                      if (conf->radio_idx >= 0 &&
++                          (radio_mask & BIT(conf->radio_idx)))
++                              return false;
++              }
+       }
+ 
+       return true;
+ }
+ 
+ static bool ieee80211_can_scan(struct ieee80211_local *local,
+-                             struct ieee80211_sub_if_data *sdata)
++                             struct ieee80211_sub_if_data *sdata,
++                             u32 radio_mask)
+ {
+-      if (!__ieee80211_can_leave_ch(sdata))
+-              return false;
+-
+-      if (!list_empty(&local->roc_list))
++      if (!list_empty(&local->roc_list) &&
++          (!local->hw.wiphy->n_radio ||
++           (radio_mask & ieee80211_offchannel_radio_mask(local))))
+               return false;
+ 
+       if (sdata->vif.type == NL80211_IFTYPE_STATION &&
+@@ -612,15 +659,22 @@ static bool ieee80211_can_scan(struct ie
+ 
+ void ieee80211_run_deferred_scan(struct ieee80211_local *local)
+ {
++      struct ieee80211_sub_if_data *sdata;
++      struct cfg80211_scan_request *req;
++      u32 radio_mask;
++
+       lockdep_assert_wiphy(local->hw.wiphy);
+ 
+-      if (!local->scan_req || local->scanning)
++      req = wiphy_dereference(local->hw.wiphy, local->scan_req);
++      if (!req || local->scanning)
++              return;
++
++      radio_mask = ieee80211_scan_req_radio_mask(local, req);
++      sdata = wiphy_dereference(local->hw.wiphy, local->scan_sdata);
++      if (!ieee80211_can_leave_ch(sdata, radio_mask))
+               return;
+ 
+-      if (!ieee80211_can_scan(local,
+-                              rcu_dereference_protected(
+-                                      local->scan_sdata,
+-                                      lockdep_is_held(&local->hw.wiphy->mtx))))
++      if (!ieee80211_can_scan(local, sdata, radio_mask))
+               return;
+ 
+       wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
+@@ -703,6 +757,7 @@ static int __ieee80211_start_scan(struct
+ {
+       struct ieee80211_local *local = sdata->local;
+       bool hw_scan = local->ops->hw_scan;
++      u32 radio_mask;
+       int rc;
+ 
+       lockdep_assert_wiphy(local->hw.wiphy);
+@@ -717,10 +772,11 @@ static int __ieee80211_start_scan(struct
+           !(sdata->vif.active_links & BIT(req->tsf_report_link_id)))
+               return -EINVAL;
+ 
+-      if (!__ieee80211_can_leave_ch(sdata))
++      radio_mask = ieee80211_scan_req_radio_mask(local, req);
++      if (!ieee80211_can_leave_ch(sdata, radio_mask))
+               return -EBUSY;
+ 
+-      if (!ieee80211_can_scan(local, sdata)) {
++      if (!ieee80211_can_scan(local, sdata, radio_mask)) {
+               /* wait for the work to finish/time out */
+               rcu_assign_pointer(local->scan_req, req);
+               rcu_assign_pointer(local->scan_sdata, sdata);
+--- a/net/mac80211/util.c
++++ b/net/mac80211/util.c
+@@ -3644,6 +3644,23 @@ again:
+       WARN_ON_ONCE(!cfg80211_chandef_valid(c));
+ }
+ 
++u32 ieee80211_chandef_radio_mask(struct ieee80211_local *local,
++                               struct cfg80211_chan_def *chandef)
++{
++      struct wiphy *wiphy = local->hw.wiphy;
++      const struct wiphy_radio *radio;
++      u32 mask = 0;
++      int i;
++
++      for (i = 0; i < wiphy->n_radio; i++) {
++              radio = &wiphy->radio[i];
++              if (cfg80211_radio_chandef_valid(radio, chandef))
++                      mask |= BIT(i);
++      }
++
++      return mask;
++}
++
+ /*
+  * Returns true if smps_mode_new is strictly more restrictive than
+  * smps_mode_old.
+--- a/net/wireless/util.c
++++ b/net/wireless/util.c
+@@ -2911,6 +2911,9 @@ bool cfg80211_radio_chandef_valid(const
+ {
+       u32 freq, width;
+ 
++      if (!cfg80211_chandef_valid(chandef))
++              return false;
++
+       freq = ieee80211_chandef_to_khz(chandef);
+       width = nl80211_chan_width_to_mhz(chandef->width);
+       if (!ieee80211_radio_freq_range_valid(radio, freq, width))