wlan-ap-Telecominfraproject/feeds/qca/hostapd/patches/r02-006-hostapd-add-channel-switch-support-with-MLO.patch

From 01689b1b95b1fc8880abfbde6c56f45e8e5b5c91 Mon Sep 17 00:00:00 2001
From: Aditya Kumar Singh <quic_adisi@quicinc.com>
Date: Fri, 13 Oct 2023 17:18:55 +0530
Subject: [PATCH] hostapd: add channel switch support with MLO

During channel switch, if its a multi-link operation, there is a requirement
to send link_id on which channel switch should take place. Also, once CSA
related events are received, it needs to be passed to appropriate link BSS
and hence hostapd_data context.

Add support for the above and hence enable channel switch with MLO.

Signed-off-by: Aditya Kumar Singh <quic_adisi@quicinc.com>
---
 src/ap/hostapd.c                   |  7 ++++
 src/drivers/driver_nl80211.c       | 36 +++++++++++++++++---
 src/drivers/driver_nl80211.h       |  1 +
 src/drivers/driver_nl80211_event.c | 54 ++++++++++++++++++------------
 4 files changed, 73 insertions(+), 25 deletions(-)

--- a/src/ap/hostapd.c
+++ b/src/ap/hostapd.c
@@ -4308,6 +4308,13 @@ static int hostapd_fill_csa_settings(str
 	settings->counter_offset_beacon[1] = hapd->cs_c_off_ecsa_beacon;
 	settings->counter_offset_presp[1] = hapd->cs_c_off_ecsa_proberesp;
 
+	settings->freq_params.link_id = -1;
+
+#ifdef CONFIG_IEEE80211BE
+	if (hapd->conf->mld_ap)
+		settings->freq_params.link_id = hapd->mld_link_id;
+#endif /* CONFIG_IEEE80211BE */
+
 	return 0;
 }
 
--- a/src/drivers/driver_nl80211.c
+++ b/src/drivers/driver_nl80211.c
@@ -4153,6 +4153,22 @@ struct i802_link * nl80211_get_link(stru
 	return bss->flink;
 }
 
+struct i802_link * nl80211_get_link_or_null(struct i802_bss *bss, u8 link_id)
+{
+	unsigned int i;
+
+	if (link_id > MAX_NUM_MLD_LINKS)
+		return NULL;
+
+	for (i = 0; i < bss->n_links; i++) {
+		if (bss->links[i].link_id != link_id)
+			continue;
+
+		return &bss->links[i];
+	}
+
+	return NULL;
+}
 
 static void nl80211_link_set_freq(struct i802_bss *bss, s8 link_id, int freq)
 {
@@ -11241,6 +11257,17 @@ static int nl80211_switch_channel(void *
 	if (settings->handle_dfs && nla_put_flag(msg, NL80211_ATTR_HANDLE_DFS))
 		goto fail;
 
+	if (nl80211_link_valid(bss, settings->freq_params.link_id)) {
+		wpa_printf(MSG_DEBUG, "nl80211: Channel switch request on link_id=%d",
+			   settings->freq_params.link_id);
+
+		if (nla_put_u8(msg, NL80211_ATTR_MLO_LINK_ID,
+			       settings->freq_params.link_id)) {
+			nlmsg_free(msg);
+			return -1;
+		}
+	}
+
 	ret = send_and_recv_msgs(drv, msg, NULL, NULL, NULL, NULL);
 	if (ret) {
 		wpa_printf(MSG_DEBUG, "nl80211: switch_channel failed err=%d (%s)",
--- a/src/drivers/driver_nl80211.h
+++ b/src/drivers/driver_nl80211.h
@@ -326,6 +326,7 @@ const char * nl80211_iftype_str(enum nl8
 
 void nl80211_restore_ap_mode(struct i802_bss *bss);
 struct i802_link * nl80211_get_link(struct i802_bss *bss, s8 link_id);
+struct i802_link * nl80211_get_link_or_null(struct i802_bss *bss, u8 link_id);
 int nl80211_valid_link(struct i802_bss *bss, s8 link_id);
 
 #ifdef ANDROID
--- a/src/drivers/driver_nl80211_event.c
+++ b/src/drivers/driver_nl80211_event.c
@@ -194,7 +194,6 @@ static const char * nl80211_command_to_s
 	return "NL80211_CMD_UNKNOWN";
 }
 
-
 static void mlme_event_auth(struct wpa_driver_nl80211_data *drv,
 			    const u8 *frame, size_t len)
 {
@@ -1198,7 +1197,7 @@ static int calculate_chan_offset(int wid
 }
 
 
-static void mlme_event_ch_switch(struct wpa_driver_nl80211_data *drv,
+static void mlme_event_ch_switch(struct i802_bss *bss,
 				 struct nlattr *ifindex, struct nlattr *link,
 				 struct nlattr *freq, struct nlattr *type,
 				 struct nlattr *bw, struct nlattr *cf1,
@@ -1209,24 +1208,34 @@ static void mlme_event_ch_switch(struct
 				 struct nlattr *ru_punct_ofdma,
 				 int finished)
 {
-	struct i802_bss *bss;
+	struct wpa_driver_nl80211_data *drv = bss->drv;
 	union wpa_event_data data;
 	int ht_enabled = 1;
 	int chan_offset = 0;
-	int ifidx;
+	int link_id = -1;
+	struct i802_link *mld_link = bss->flink;
+	void *ctx = bss->ctx;
 
-	wpa_printf(MSG_DEBUG, "nl80211: Channel switch%s event",
-		   finished ? "" : " started");
+	wpa_printf(MSG_DEBUG, "nl80211: Channel switch%s event for %s",
+		   finished ? "" : " started", bss->ifname);
 
 	if (!freq)
 		return;
 
-	ifidx = nla_get_u32(ifindex);
-	bss = get_bss_ifindex(drv, ifidx);
-	if (bss == NULL) {
-		wpa_printf(MSG_WARNING, "nl80211: Unknown ifindex (%d) for channel switch, ignoring",
-			   ifidx);
-		return;
+	if (link) {
+		link_id = nla_get_u8(link);
+		mld_link = nl80211_get_link_or_null(bss, link_id);
+		if (!mld_link) {
+			wpa_printf(MSG_DEBUG,
+				   "nl80211: Ignoring Channel switch%s event on invalid link id %d",
+				   finished ? "" : " started", link_id);
+			return;
+		}
+
+		wpa_printf(MSG_DEBUG,
+			   "nl80211: Channel switch%s event for link %d",
+			   finished ? "" : " started", link_id);
+		ctx = mld_link->ctx;
 	}
 
 	if (type) {
@@ -1280,13 +1289,10 @@ static void mlme_event_ch_switch(struct
 	}
 
 	if (finished)
-		bss->flink->freq = data.ch_switch.freq;
-
-	if (link) {
-		u8 link_id = nla_get_u8(link);
+		mld_link->freq = data.ch_switch.freq;
 
-		if (link_id < MAX_NUM_MLD_LINKS &&
-		    drv->sta_mlo_info.valid_links & BIT(link_id)) {
+	if (link_id != -1 && is_sta_interface(drv->nlmode)) {
+		if (drv->sta_mlo_info.valid_links & BIT(link_id)) {
 			data.ch_switch.link_id = link_id;
 			drv->sta_mlo_info.links[link_id].freq =
 				data.ch_switch.freq;
@@ -1302,7 +1308,13 @@ static void mlme_event_ch_switch(struct
 
 	drv->assoc_freq = data.ch_switch.freq;
 
-	wpa_supplicant_event(bss->ctx, finished ?
+	if (is_ap_interface(drv->nlmode)) {
+		wpa_supplicant_event(ctx, finished ?
+				     EVENT_CH_SWITCH : EVENT_CH_SWITCH_STARTED, &data);
+		return;
+	}
+
+	wpa_supplicant_event(ctx, finished ?
 			     EVENT_CH_SWITCH : EVENT_CH_SWITCH_STARTED, &data);
 }
 
@@ -3944,7 +3956,7 @@ static void do_process_drv_event(struct
 				   tb[NL80211_ATTR_MLO_LINKS]);
 		break;
 	case NL80211_CMD_CH_SWITCH_STARTED_NOTIFY:
-		mlme_event_ch_switch(drv,
+		mlme_event_ch_switch(bss,
 				     tb[NL80211_ATTR_IFINDEX],
 				     tb[NL80211_ATTR_MLO_LINK_ID],
 				     tb[NL80211_ATTR_WIPHY_FREQ],
@@ -3959,7 +3971,7 @@ static void do_process_drv_event(struct
 				     0);
 		break;
 	case NL80211_CMD_CH_SWITCH_NOTIFY:
-		mlme_event_ch_switch(drv,
+		mlme_event_ch_switch(bss,
 				     tb[NL80211_ATTR_IFINDEX],
 				     tb[NL80211_ATTR_MLO_LINK_ID],
 				     tb[NL80211_ATTR_WIPHY_FREQ],