package/kernel/mac80211/patches/subsys/320-cfg80211-allow-grace-period-for-DFS-available-after-.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Thu, 14 Sep 2023 13:17:16 +0200
   3 Subject: [PATCH] cfg80211: allow grace period for DFS available after beacon
   4  shutdown
   5
   6 Fixes reconfiguring an AP on a DFS channel in non-ETSI regdomain
   7
   8 Fixes: b35a51c7dd25 ("cfg80211: Make pre-CAC results valid only for ETSI domain")
   9 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  10 ---
  11
  12 --- a/include/net/cfg80211.h
  13 +++ b/include/net/cfg80211.h
  14 @@ -175,6 +175,8 @@ enum ieee80211_channel_flags {
  15   * @dfs_state: current state of this channel. Only relevant if radar is required
  16   *     on this channel.
  17   * @dfs_state_entered: timestamp (jiffies) when the dfs state was entered.
  18 + * @dfs_state_last_available: timestamp (jiffies) of the last time when the
  19 + *     channel was available.
  20   * @dfs_cac_ms: DFS CAC time in milliseconds, this is valid for DFS channels.
  21   */
  22  struct ieee80211_channel {
  23 @@ -191,6 +193,7 @@ struct ieee80211_channel {
  24         int orig_mag, orig_mpwr;
  25         enum nl80211_dfs_state dfs_state;
  26         unsigned long dfs_state_entered;
  27 +       unsigned long dfs_state_last_available;
  28         unsigned int dfs_cac_ms;
  29  };
  30
  31 --- a/net/wireless/ap.c
  32 +++ b/net/wireless/ap.c
  33 @@ -30,6 +30,9 @@ static int ___cfg80211_stop_ap(struct cf
  34         if (!wdev->links[link_id].ap.beacon_interval)
  35                 return -ENOENT;
  36
  37 +       cfg80211_update_last_available(wdev->wiphy,
  38 +                                      &wdev->links[link_id].ap.chandef);
  39 +
  40         err = rdev_stop_ap(rdev, dev, link_id);
  41         if (!err) {
  42                 wdev->conn_owner_nlportid = 0;
  43 @@ -41,9 +44,6 @@ static int ___cfg80211_stop_ap(struct cf
  44                 if (notify)
  45                         nl80211_send_ap_stopped(wdev, link_id);
  46
  47 -               /* Should we apply the grace period during beaconing interface
  48 -                * shutdown also?
  49 -                */
  50                 cfg80211_sched_dfs_chan_update(rdev);
  51         }
  52
  53 --- a/net/wireless/chan.c
  54 +++ b/net/wireless/chan.c
  55 @@ -461,6 +461,8 @@ static void cfg80211_set_chans_dfs_state
  56
  57                 c->dfs_state = dfs_state;
  58                 c->dfs_state_entered = jiffies;
  59 +               if (dfs_state == NL80211_DFS_AVAILABLE)
  60 +                       c->dfs_state_last_available = jiffies;
  61         }
  62  }
  63
  64 @@ -874,6 +876,49 @@ static bool cfg80211_get_chans_dfs_avail
  65         return true;
  66  }
  67
  68 +static void
  69 +__cfg80211_update_last_available(struct wiphy *wiphy,
  70 +                                        u32 center_freq,
  71 +                                        u32 bandwidth)
  72 +{
  73 +       struct ieee80211_channel *c;
  74 +       u32 freq, start_freq, end_freq;
  75 +
  76 +       start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
  77 +       end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
  78 +
  79 +       /*
  80 +        * Check entire range of channels for the bandwidth.
  81 +        * If any channel in between is disabled or has not
  82 +        * had gone through CAC return false
  83 +        */
  84 +       for (freq = start_freq; freq <= end_freq; freq += MHZ_TO_KHZ(20)) {
  85 +               c = ieee80211_get_channel_khz(wiphy, freq);
  86 +               if (!c)
  87 +                       return;
  88 +
  89 +               c->dfs_state_last_available = jiffies;
  90 +       }
  91 +}
  92 +
  93 +void cfg80211_update_last_available(struct wiphy *wiphy,
  94 +                                   const struct cfg80211_chan_def *chandef)
  95 +{
  96 +       int width;
  97 +
  98 +       width = cfg80211_chandef_get_width(chandef);
  99 +       if (width < 0)
 100 +               return;
 101 +
 102 +       __cfg80211_update_last_available(wiphy, MHZ_TO_KHZ(chandef->center_freq1),
 103 +                                                width);
 104 +       if (chandef->width != NL80211_CHAN_WIDTH_80P80)
 105 +           return;
 106 +
 107 +       __cfg80211_update_last_available(wiphy, MHZ_TO_KHZ(chandef->center_freq2),
 108 +                                                width);
 109 +}
 110 +
 111  static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
 112                                 const struct cfg80211_chan_def *chandef)
 113  {
 114 --- a/net/wireless/core.h
 115 +++ b/net/wireless/core.h
 116 @@ -481,6 +481,8 @@ void cfg80211_set_dfs_state(struct wiphy
 117                             enum nl80211_dfs_state dfs_state);
 118
 119  void cfg80211_dfs_channels_update_work(struct work_struct *work);
 120 +void cfg80211_update_last_available(struct wiphy *wiphy,
 121 +                                   const struct cfg80211_chan_def *chandef);
 122
 123  void cfg80211_sched_dfs_chan_update(struct cfg80211_registered_device *rdev);
 124
 125 --- a/net/wireless/mlme.c
 126 +++ b/net/wireless/mlme.c
 127 @@ -930,6 +930,8 @@ void cfg80211_dfs_channels_update_work(s
 128                         if (c->dfs_state == NL80211_DFS_UNAVAILABLE) {
 129                                 time_dfs_update = IEEE80211_DFS_MIN_NOP_TIME_MS;
 130                                 radar_event = NL80211_RADAR_NOP_FINISHED;
 131 +                               timeout = c->dfs_state_entered +
 132 +                                         msecs_to_jiffies(time_dfs_update);
 133                         } else {
 134                                 if (regulatory_pre_cac_allowed(wiphy) ||
 135                                     cfg80211_any_wiphy_oper_chan(wiphy, c))
 136 @@ -937,11 +939,10 @@ void cfg80211_dfs_channels_update_work(s
 137
 138                                 time_dfs_update = REG_PRE_CAC_EXPIRY_GRACE_MS;
 139                                 radar_event = NL80211_RADAR_PRE_CAC_EXPIRED;
 140 +                               timeout = c->dfs_state_last_available +
 141 +                                         msecs_to_jiffies(time_dfs_update);
 142                         }
 143
 144 -                       timeout = c->dfs_state_entered +
 145 -                                 msecs_to_jiffies(time_dfs_update);
 146 -
 147                         if (time_after_eq(jiffies, timeout)) {
 148                                 c->dfs_state = NL80211_DFS_USABLE;
 149                                 c->dfs_state_entered = jiffies;