DFS: More debug prints on channel selection after radar detection

This makes it easier to understand what is happening when a new channel
needs to be selected based on a radar detection event.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>

diff --git a/src/ap/dfs.c b/src/ap/dfs.c
index d0b448e2958fcd4dc894d27f27ac01211bb2e982..6c8cd6cac07fbe65a76984aed74e3eeb731f8d8a 100644 (file)
--- a/src/ap/dfs.c
+++ b/src/ap/dfs.c
@@ -144,30 +144,44 @@ static int dfs_chan_range_available(struct hostapd_hw_modes *mode,
        int i;
        u32 bw = num_chan_to_bw(num_chans);
 
-       if (first_chan_idx + num_chans > mode->num_channels)
+       if (first_chan_idx + num_chans > mode->num_channels) {
+               wpa_printf(MSG_DEBUG,
+                          "DFS: some channels in range not defined");
                return 0;
+       }
 
        first_chan = &mode->channels[first_chan_idx];
 
        /* hostapd DFS implementation assumes the first channel as primary.
         * If it's not allowed to use the first channel as primary, decline the
         * whole channel range. */
-       if (!chan_pri_allowed(first_chan))
+       if (!chan_pri_allowed(first_chan)) {
+               wpa_printf(MSG_DEBUG, "DFS: primary chanenl not allowed");
                return 0;
+       }
 
        for (i = 0; i < num_chans; i++) {
                chan = dfs_get_chan_data(mode, first_chan->freq + i * 20,
                                         first_chan_idx);
-               if (!chan)
+               if (!chan) {
+                       wpa_printf(MSG_DEBUG, "DFS: no channel data for %d",
+                                  first_chan->freq + i * 20);
                        return 0;
+               }
 
                /* HT 40 MHz secondary channel availability checked only for
                 * primary channel */
-               if (!chan_bw_allowed(chan, bw, 1, !i))
+               if (!chan_bw_allowed(chan, bw, 1, !i)) {
+                       wpa_printf(MSG_DEBUG, "DFS: bw now allowed for %d",
+                                  first_chan->freq + i * 20);
                        return 0;
+               }
 
-               if (!dfs_channel_available(chan, skip_radar))
+               if (!dfs_channel_available(chan, skip_radar)) {
+                       wpa_printf(MSG_DEBUG, "DFS: channel not available %d",
+                                  first_chan->freq + i * 20);
                        return 0;
+               }
        }
 
        return 1;
@@ -210,22 +224,36 @@ static int dfs_find_channel(struct hostapd_iface *iface,
                if (iface->conf->ieee80211n &&
                    iface->conf->secondary_channel &&
                    (!dfs_is_chan_allowed(chan, n_chans) ||
-                    !(chan->allowed_bw & HOSTAPD_CHAN_WIDTH_40P)))
+                    !(chan->allowed_bw & HOSTAPD_CHAN_WIDTH_40P))) {
+                       wpa_printf(MSG_DEBUG,
+                                  "DFS: channel %d (%d) is incompatible",
+                                  chan->freq, chan->chan);
                        continue;
+               }
 
                /* Skip incompatible chandefs */
-               if (!dfs_chan_range_available(mode, i, n_chans, skip_radar))
+               if (!dfs_chan_range_available(mode, i, n_chans, skip_radar)) {
+                       wpa_printf(MSG_DEBUG,
+                                  "DFS: range not available for %d (%d)",
+                                  chan->freq, chan->chan);
                        continue;
+               }
 
-               if (!is_in_chanlist(iface, chan))
+               if (!is_in_chanlist(iface, chan)) {
+                       wpa_printf(MSG_DEBUG,
+                                  "DFS: channel %d (%d) not in chanlist",
+                                  chan->freq, chan->chan);
                        continue;
+               }
 
                if (ret_chan && idx == channel_idx) {
-                       wpa_printf(MSG_DEBUG, "Selected ch. #%d", chan->chan);
+                       wpa_printf(MSG_DEBUG, "Selected channel %d (%d)",
+                                  chan->freq, chan->chan);
                        *ret_chan = chan;
                        return idx;
                }
-               wpa_printf(MSG_DEBUG, "Adding channel: %d", chan->chan);
+               wpa_printf(MSG_DEBUG, "Adding channel %d (%d)",
+                          chan->freq, chan->chan);
                channel_idx++;
        }
        return channel_idx;
@@ -459,6 +487,8 @@ dfs_get_valid_channel(struct hostapd_iface *iface,
 
        /* Get the count first */
        num_available_chandefs = dfs_find_channel(iface, NULL, 0, skip_radar);
+       wpa_printf(MSG_DEBUG, "DFS: num_available_chandefs=%d",
+                  num_available_chandefs);
        if (num_available_chandefs == 0)
                return NULL;
 
@@ -466,6 +496,11 @@ dfs_get_valid_channel(struct hostapd_iface *iface,
                return NULL;
        chan_idx = _rand % num_available_chandefs;
        dfs_find_channel(iface, &chan, chan_idx, skip_radar);
+       if (chan)
+               wpa_printf(MSG_DEBUG, "DFS: got random channel %d (%d)",
+                          chan->freq, chan->chan);
+       else
+               wpa_printf(MSG_DEBUG, "DFS: no random channel found");
 
        /* dfs_find_channel() calculations assume HT40+ */
        if (iface->conf->secondary_channel)