WNM: Extend the discovery of the 6 GHz candidates

Candidates on 6 GHz channels might be collocated ones, and thus, in
order to discover them need to include the frequencies on the 2.4/5 GHz
bands.

Extend the WNM scan frequency channels to include the 2.4/5 GHz channels
in case the WNM neighbor list included candidates on the 6 GHz band.
Since such a scan can be long, optimize the case of a single channel and
instead force passive scanning.

In addition, in case the candidate validity interval is too short,
ignore the validity interval, and set it to 5 seconds, as we are
increasing the discovery time so results might not be valid once we get
them.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Reviewed-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>

diff --git a/wpa_supplicant/wnm_sta.c b/wpa_supplicant/wnm_sta.c
index 8c8f243d5ad33a797530aaf06fc481b3c9f47dd8..9c8f37aeb9e794fa3a5e7f27bccab6dee18986bc 100644 (file)
--- a/wpa_supplicant/wnm_sta.c
+++ b/wpa_supplicant/wnm_sta.c
@@ -1339,6 +1339,7 @@ static int chan_supported(struct wpa_supplicant *wpa_s, int freq)
 static void wnm_set_scan_freqs(struct wpa_supplicant *wpa_s)
 {
        unsigned int i;
+       bool has_6ghz = false;
 
        if (!wpa_s->wnm_neighbor_report_elements)
                return;
@@ -1369,6 +1370,7 @@ static void wnm_set_scan_freqs(struct wpa_supplicant *wpa_s)
                if (chan_supported(wpa_s, nei->freq))
                        int_array_add_unique(&wpa_s->next_scan_freqs,
                                             nei->freq);
+               has_6ghz |= is_6ghz_freq(nei->freq);
        }
 
        if (!wpa_s->next_scan_freqs)
@@ -1377,6 +1379,70 @@ static void wnm_set_scan_freqs(struct wpa_supplicant *wpa_s)
        wpa_printf(MSG_DEBUG,
                   "WNM: Scan %zu frequencies based on transition candidate list",
                   int_array_len(wpa_s->next_scan_freqs));
+
+       /*
+        * Candidates on 6 GHz channels might be collocated ones, and thus, in
+        * order to discover them need to include the frequencies on the 2.4
+        * and 5 GHz bands. Since the scan time can be long, optimize the case
+        * of a single channel by forcing passive scan instead of doing a
+        * collocated scan.
+        */
+       if (has_6ghz) {
+               struct hostapd_channel_data *chan;
+               struct os_reltime now;
+
+               /* In case the candidate validity time is too short, force it
+                * to be long enough to account for the longer scan time.
+                */
+               os_get_reltime(&now);
+               now.sec += 5;
+
+               if (os_reltime_initialized(&wpa_s->wnm_cand_valid_until) &&
+                   !os_reltime_before(&wpa_s->wnm_cand_valid_until, &now)) {
+                       wpa_printf(MSG_DEBUG,
+                                  "WNM: Scan: 6 GHz: update validity time");
+
+                       os_memcpy(&wpa_s->wnm_cand_valid_until, &now,
+                                 sizeof(now));
+               }
+
+               if (int_array_len(wpa_s->next_scan_freqs) == 1) {
+                       wpa_printf(MSG_DEBUG,
+                                  "WNM: Scan: Single 6 GHz channel: passive");
+
+                       wpa_s->scan_req = MANUAL_SCAN_REQ;
+                       wpa_s->manual_scan_passive = 1;
+                       return;
+               }
+
+               wpa_printf(MSG_DEBUG,
+                          "WNM: Scan: Add 2.4/5 GHz channels as well for 6 GHz discovery");
+
+               for (i = 0; i < wpa_s->hw.num_modes; i++) {
+                       struct hostapd_hw_modes *mode = &wpa_s->hw.modes[i];
+                       int j;
+
+                       /* skip all the irrelevant modes */
+                       if ((mode->mode != HOSTAPD_MODE_IEEE80211B &&
+                            mode->mode != HOSTAPD_MODE_IEEE80211G &&
+                            mode->mode != HOSTAPD_MODE_IEEE80211A) ||
+                           mode->is_6ghz)
+                               continue;
+
+                       for (j = 0; j < mode->num_channels; j++) {
+                               chan = &mode->channels[j];
+                               if (chan->flag & HOSTAPD_CHAN_DISABLED)
+                                       continue;
+
+                               int_array_add_unique(&wpa_s->next_scan_freqs,
+                                                    chan->freq);
+                       }
+               }
+
+               wpa_printf(MSG_DEBUG,
+                          "WNM: Scan %zu frequencies (including collocated)",
+                          int_array_len(wpa_s->next_scan_freqs));
+       }
 }