wlan-ap-Telecominfraproject/feeds/qca/hostapd/patches/q05-006-hostapd-Remove-hard-coded-DFS-CAC-time-in-driver-off.patch

From 51a582a35b5d2d8e624d81bb965729b385644f1d Mon Sep 17 00:00:00 2001
From: Manish Dharanenthiran <quic_mdharane@quicinc.com>
Date: Fri, 31 Mar 2023 11:51:38 +0530
Subject: [PATCH] hostapd: Remove hard-coded DFS CAC time in driver offloaded
 cac

During driver offloaded CAC, CAC time is set to 60000
by default. Because of this, CAC time is wrongly depcited in
info debug, also getting saved in interface config which
may lead to wrong CAC time calculation.

Fix this by calculating CAC time based on the channel width
and channel number specified during CAC trigger.

Signed-off-by: Manish Dharanenthiran <quic_mdharane@quicinc.com>
---
 src/ap/dfs.c | 107 ++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 88 insertions(+), 19 deletions(-)

--- a/src/ap/dfs.c
+++ b/src/ap/dfs.c
@@ -21,6 +21,8 @@
 #include "eloop.h"
 #include "ieee802_11.h"
 
+#define IEEE80211_DFS_MIN_CAC_TIME_MS  60000
+
 enum dfs_channel_type {
 	DFS_ANY_CHANNEL,
 	DFS_AVAILABLE, /* non-radar or radar-available */
@@ -40,7 +42,8 @@ static bool dfs_use_radar_background(str
 		iface->conf->enable_background_radar;
 }
 
-static int dfs_get_used_n_chans(struct hostapd_iface *iface, int *seg1)
+static int dfs_get_used_n_chans(struct hostapd_iface *iface, int *seg1,
+				int chan_width)
 {
 	int n_chans = 1;
 
@@ -51,7 +54,7 @@ static int dfs_get_used_n_chans(struct h
 
 	if (iface->conf->ieee80211ac || iface->conf->ieee80211ax ||
 	    iface->conf->ieee80211be) {
-		switch (hostapd_get_oper_chwidth(iface->conf)) {
+		switch (chan_width) {
 		case CONF_OPER_CHWIDTH_USE_HT:
 			break;
 		case CONF_OPER_CHWIDTH_80MHZ:
@@ -319,7 +322,8 @@ static int dfs_find_channel(struct hosta
 	int i, channel_idx = 0, n_chans, n_chans1;
 
 	mode = iface->current_mode;
-	n_chans = dfs_get_used_n_chans(iface, &n_chans1);
+	n_chans = dfs_get_used_n_chans(iface, &n_chans1,
+				       hostapd_get_oper_chwidth(iface->conf));
 
 	wpa_printf(MSG_DEBUG, "DFS new chan checking %d channels", n_chans);
 	for (i = 0; i < mode->num_channels; i++) {
@@ -432,11 +436,11 @@ static void dfs_adjust_center_freq(struc
 
 
 /* Return start channel idx we will use for mode->channels[idx] */
-static int dfs_get_start_chan_idx(struct hostapd_iface *iface, int *seg1_start)
+static int dfs_get_start_chan_idx(struct hostapd_iface *iface, int *seg1_start,
+				  int chan_width, int channel_no, bool is_offloaded_cac)
 {
 	struct hostapd_hw_modes *mode;
 	struct hostapd_channel_data *chan;
-	int channel_no = iface->conf->channel;
 	int res = -1, i;
 	int chan_seg1 = -1;
 
@@ -447,9 +451,9 @@ static int dfs_get_start_chan_idx(struct
 		channel_no -= 4;
 
 	/* VHT/HE */
-	if (iface->conf->ieee80211ac || iface->conf->ieee80211ax ||
-	    iface->conf->ieee80211be) {
-		switch (hostapd_get_oper_chwidth(iface->conf)) {
+	if ((iface->conf->ieee80211ac || iface->conf->ieee80211ax ||
+	    iface->conf->ieee80211be) && !is_offloaded_cac) {
+		switch (chan_width) {
 		case CONF_OPER_CHWIDTH_USE_HT:
 			break;
 		case CONF_OPER_CHWIDTH_80MHZ:
@@ -836,11 +840,13 @@ static int dfs_are_channels_overlapped(s
 	int n_chans, n_chans1, i, j, frequency = freq, radar_n_chans = 1;
 	u8 radar_chan;
 	int res = 0;
+	int cur_chan_width = hostapd_get_oper_chwidth(iface->conf);
 
 	/* Our configuration */
 	mode = iface->current_mode;
-	start_chan_idx = dfs_get_start_chan_idx(iface, &start_chan_idx1);
-	n_chans = dfs_get_used_n_chans(iface, &n_chans1);
+	start_chan_idx = dfs_get_start_chan_idx(iface, &start_chan_idx1, cur_chan_width,
+						iface->conf->channel, false);
+	n_chans = dfs_get_used_n_chans(iface, &n_chans1, cur_chan_width);
 
 	/* Check we are on DFS channel(s) */
 	if (!dfs_check_chans_radar(iface, start_chan_idx, n_chans))
@@ -928,6 +934,7 @@ int hostapd_handle_dfs(struct hostapd_if
 {
 	int res, n_chans, n_chans1, start_chan_idx, start_chan_idx1;
 	int skip_radar = 0;
+	int chan_width = hostapd_get_oper_chwidth(iface->conf);
 
 	if (is_6ghz_freq(iface->freq))
 		return 1;
@@ -947,12 +954,13 @@ int hostapd_handle_dfs(struct hostapd_if
 	do {
 		/* Get start (first) channel for current configuration */
 		start_chan_idx = dfs_get_start_chan_idx(iface,
-							&start_chan_idx1);
+							&start_chan_idx1, chan_width,
+							iface->conf->channel, false);
 		if (start_chan_idx == -1)
 			return -1;
 
 		/* Get number of used channels, depend on width */
-		n_chans = dfs_get_used_n_chans(iface, &n_chans1);
+		n_chans = dfs_get_used_n_chans(iface, &n_chans1, chan_width);
 
 		/* Setup CAC time */
 		iface->dfs_cac_ms = dfs_get_cac_time(iface, start_chan_idx,
@@ -1047,14 +1055,17 @@ int hostapd_handle_dfs(struct hostapd_if
 int hostapd_is_dfs_chan_available(struct hostapd_iface *iface)
 {
 	int n_chans, n_chans1, start_chan_idx, start_chan_idx1;
+	int chan_width = hostapd_get_oper_chwidth(iface->conf);
 
 	/* Get the start (first) channel for current configuration */
-	start_chan_idx = dfs_get_start_chan_idx(iface, &start_chan_idx1);
+	start_chan_idx = dfs_get_start_chan_idx(iface, &start_chan_idx1,
+						chan_width,
+						iface->conf->channel, false);
 	if (start_chan_idx < 0)
 		return 0;
 
 	/* Get the number of used channels, depending on width */
-	n_chans = dfs_get_used_n_chans(iface, &n_chans1);
+	n_chans = dfs_get_used_n_chans(iface, &n_chans1, chan_width);
 
 	/* Check if all channels are DFS available */
 	return dfs_check_chans_available(iface, start_chan_idx, n_chans);
@@ -1806,6 +1817,7 @@ int hostapd_dfs_nop_finished(struct host
 int hostapd_is_dfs_required(struct hostapd_iface *iface)
 {
 	int n_chans, n_chans1, start_chan_idx, start_chan_idx1, res;
+	int chan_width = hostapd_get_oper_chwidth(iface->conf);
 
 	if ((!(iface->drv_flags & WPA_DRIVER_FLAGS_DFS_OFFLOAD) &&
 	     !iface->conf->ieee80211h) ||
@@ -1814,12 +1826,14 @@ int hostapd_is_dfs_required(struct hosta
 		return 0;
 
 	/* Get start (first) channel for current configuration */
-	start_chan_idx = dfs_get_start_chan_idx(iface, &start_chan_idx1);
+	start_chan_idx = dfs_get_start_chan_idx(iface, &start_chan_idx1,
+						chan_width,
+						iface->conf->channel, false);
 	if (start_chan_idx == -1)
 		return -1;
 
 	/* Get number of used channels, depend on width */
-	n_chans = dfs_get_used_n_chans(iface, &n_chans1);
+	n_chans = dfs_get_used_n_chans(iface, &n_chans1, chan_width);
 
 	/* Check if any of configured channels require DFS */
 	res = dfs_check_chans_radar(iface, start_chan_idx, n_chans);
@@ -1830,12 +1844,16 @@ int hostapd_is_dfs_required(struct hosta
 	return res;
 }
 
-
 int hostapd_dfs_start_cac(struct hostapd_iface *iface, int freq,
 			  int ht_enabled, int chan_offset, int chan_width,
 			  int cf1, int cf2, bool is_background)
 {
-	if (is_background || hostapd_dfs_is_background_event(iface, freq)) {
+	int n_chans, n_chans1, ch_idx, ch_idx_1, dfs_cac_ms;
+	int chwidth;
+	u8 channel_no, cf1_ch_no;
+	bool is_background_event = hostapd_dfs_is_background_event(iface, freq);
+
+	if (is_background || is_background_event) {
 		iface->radar_background.cac_started = 1;
 	} else {
 		/* This is called when the driver indicates that an offloaded
@@ -1843,13 +1861,73 @@ int hostapd_dfs_start_cac(struct hostapd
 		hostapd_set_state(iface, HAPD_IFACE_DFS);
 		iface->cac_started = 1;
 	}
-	/* TODO: How to check CAC time for ETSI weather channels? */
-	iface->dfs_cac_ms = 60000;
+
+	/* Get channel number */
+	ieee80211_freq_to_chan(freq, &channel_no);
+
+	/* Get seq1 channel number */
+	ieee80211_freq_to_chan(cf1, &cf1_ch_no);
+
+	switch (chan_width) {
+	case CHAN_WIDTH_80:
+		chwidth = CONF_OPER_CHWIDTH_80MHZ;
+		cf1_ch_no -= 6;
+		break;
+	case CHAN_WIDTH_80P80:
+		chwidth = CONF_OPER_CHWIDTH_80P80MHZ;
+		cf1_ch_no -= 6;
+		break;
+	case CHAN_WIDTH_160:
+		chwidth = CONF_OPER_CHWIDTH_160MHZ;
+		cf1_ch_no -= 14;
+		break;
+	case CHAN_WIDTH_320:
+		chwidth = CONF_OPER_CHWIDTH_320MHZ;
+		cf1_ch_no -= 30;
+		break;
+	case CHAN_WIDTH_20_NOHT:
+	case CHAN_WIDTH_20:
+	case CHAN_WIDTH_40:
+	default:
+		chwidth = CONF_OPER_CHWIDTH_USE_HT;
+		break;
+	}
+
+	/* Get idx */
+	ch_idx = dfs_get_start_chan_idx(iface,
+					&ch_idx_1, chwidth,
+					(chwidth == CHANWIDTH_USE_HT) ? channel_no :
+					cf1_ch_no, true);
+	if (ch_idx == -1)
+		return -1;
+
+	/* Get number of used channels, depend on width */
+	n_chans = dfs_get_used_n_chans(iface, &n_chans1,
+				       chwidth);
+	if (n_chans == -1)
+		return -1;
+
+	dfs_cac_ms = dfs_get_cac_time(iface, ch_idx, n_chans);
+	/* Set minimum cac millisecond it it's not configured for
+	 * the given channel from driver.
+	 */
+	if (!dfs_cac_ms) {
+		/* TODO: How to check CAC time for ETSI weather channels? */
+		dfs_cac_ms = IEEE80211_DFS_MIN_CAC_TIME_MS;
+	}
+
+	/* Save dfs cac time to current iface configonly when DFS
+	 * is offloaded and cac event is not a background event
+	 */
+	if (iface->drv_flags & WPA_DRIVER_FLAGS_DFS_OFFLOAD &&
+	    !is_background_event)
+		iface->dfs_cac_ms = dfs_cac_ms;
+
 	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_START
 		"freq=%d chan=%d chan_offset=%d width=%d seg0=%d "
 		"seg1=%d cac_time=%ds%s",
 		freq, (freq - 5000) / 5, chan_offset, chan_width, cf1, cf2,
-		iface->dfs_cac_ms / 1000,
+		dfs_cac_ms / 1000,
 		hostapd_dfs_is_background_event(iface, freq) ?
 		" (background)" : "");