hostapd: Avoid channel selection across underlying hardware index

Currently, channel is selected from the current hw_mode. However, not
all channels under current hw_mode might be available for the current
operating underlying hardware.

Add logic to check if the selected channel falls under the current
operating hardware index and only if so, continue with the selected
channel.

Co-developed-by: Harshitha Prem <quic_hprem@quicinc.com>
Signed-off-by: Harshitha Prem <quic_hprem@quicinc.com>
Signed-off-by: Aditya Kumar Singh <quic_adisi@quicinc.com>

hostapd/ctrl_iface.c

@@ -2454,6 +2454,31 @@ static int hostapd_ctrl_register_frame(struct hostapd_data *hapd,
 
 
 #ifdef NEED_AP_MLME
+
+static bool
+hostapd_ctrl_is_freq_in_cmode(struct hostapd_hw_modes *mode,
+			      struct hostapd_multi_hw_info *current_hw_info,
+			      int freq)
+{
+	struct hostapd_channel_data *chan;
+	int i;
+
+	for (i = 0; i < mode->num_channels; i++) {
+		chan = &mode->channels[i];
+
+		if (chan->flag & HOSTAPD_CHAN_DISABLED)
+			continue;
+
+		if (!chan_in_current_hw_info(current_hw_info, chan))
+			continue;
+
+		if (chan->freq == freq)
+			return true;
+	}
+	return false;
+}
+
+
 static int hostapd_ctrl_check_freq_params(struct hostapd_freq_params *params,
 					  u16 punct_bitmap)
 {
@@ -2668,6 +2693,15 @@ static int hostapd_ctrl_iface_chan_switch(struct hostapd_iface *iface,
 		settings.link_id = iface->bss[0]->mld_link_id;
 #endif /* CONFIG_IEEE80211BE */
 
+	if (iface->num_hw_features > 1 &&
+	    !hostapd_ctrl_is_freq_in_cmode(iface->current_mode,
+					   iface->current_hw_info,
+					   settings.freq_params.freq)) {
+		wpa_printf(MSG_INFO,
+			   "chanswitch: Invalid frequency settings provided for multi band phy");
+		return -1;
+	}
+
 	ret = hostapd_ctrl_check_freq_params(&settings.freq_params,
 					     settings.punct_bitmap);
 	if (ret) {

src/ap/dfs.c

@@ -253,6 +253,13 @@ static int dfs_find_channel(struct hostapd_iface *iface,
 	for (i = 0; i < mode->num_channels; i++) {
 		chan = &mode->channels[i];
 
+		if (!chan_in_current_hw_info(iface->current_hw_info, chan)) {
+			wpa_printf(MSG_DEBUG,
+				   "DFS: channel %d (%d) is not under current hardware index",
+				   chan->freq, chan->chan);
+			continue;
+		}
+
 		/* Skip HT40/VHT incompatible channels */
 		if (iface->conf->ieee80211n &&
 		    iface->conf->secondary_channel &&

src/common/hw_features_common.c

@@ -1033,3 +1033,18 @@ bool is_punct_bitmap_valid(u16 bw, u16 pri_ch_bit_pos, u16 punct_bitmap)
 
 	return false;
 }
+
+
+bool chan_in_current_hw_info(struct hostapd_multi_hw_info *current_hw_info,
+			     struct hostapd_channel_data *chan)
+{
+	/* Assuming that if current_hw_info is not set full
+	 * iface->current_mode->channels[] can be used to scan for channels,
+	 * hence we return true.
+	 */
+	if (!current_hw_info)
+		return true;
+
+	return current_hw_info->start_freq <= chan->freq &&
+		current_hw_info->end_freq >= chan->freq;
+}

src/common/hw_features_common.h

@@ -58,5 +58,7 @@ int chan_bw_allowed(const struct hostapd_channel_data *chan, u32 bw,
 		    int ht40_plus, int pri);
 int chan_pri_allowed(const struct hostapd_channel_data *chan);
 bool is_punct_bitmap_valid(u16 bw, u16 pri_ch_bit_pos, u16 punct_bitmap);
+bool chan_in_current_hw_info(struct hostapd_multi_hw_info *current_hw_info,
+			     struct hostapd_channel_data *chan);
 
 #endif /* HW_FEATURES_COMMON_H */