[PATCH] hostapd: fix opclass during CSA with DFS channels

[marek at mazekey.pl]

During CSA with DFS channels, disable, enable interface
is a part of the algorithm.
When interface was enabled old operating class before switch
and new channel were used causing mismatch in
configured_fixed_chan_to_freq function.

Example of log when switch from channel 157 to 108 was triggered:
"Could not convert op_class 124 channel 108 to operating frequency"

Fixes: bb781c763 ("AP: Populate iface->freq before starting AP")

Signed-off-by: Marek Kwaczynski <marek at mazekey.pl>
---
  src/ap/hostapd.c | 7 +++++++
  1 file changed, 7 insertions(+)

diff --git a/src/ap/hostapd.c b/src/ap/hostapd.c
index 130b6ebc6..8d0601e6a 100644
--- a/src/ap/hostapd.c
+++ b/src/ap/hostapd.c
@@ -4466,6 +4466,8 @@ hostapd_switch_channel_fallback(struct 
hostapd_iface *iface,
  {
         u8 seg0_idx = 0, seg1_idx = 0;
         enum oper_chan_width bw = CONF_OPER_CHWIDTH_USE_HT;
+       u8 op_class;
+       u8 chan;

         wpa_printf(MSG_DEBUG, "Restarting all CSA-related BSSes");

@@ -4505,6 +4507,11 @@ hostapd_switch_channel_fallback(struct 
hostapd_iface *iface,
         iface->freq = freq_params->freq;
         iface->conf->channel = freq_params->channel;
         iface->conf->secondary_channel = 
freq_params->sec_channel_offset;
+       ieee80211_freq_to_channel_ext(freq_params->freq, 
freq_params->sec_channel_offset, bw, &op_class, &chan);
+       if (chan != freq_params->channel)
+               wpa_printf(MSG_ERROR, "Channel mismatch: %d -> %d", 
freq_params->channel, chan);
+
+       iface->conf->op_class = op_class;
         hostapd_set_oper_centr_freq_seg0_idx(iface->conf, seg0_idx);
         hostapd_set_oper_centr_freq_seg1_idx(iface->conf, seg1_idx);
         hostapd_set_oper_chwidth(iface->conf, bw);
-- 
2.34.1