mac80211: convert S1G beacon to scan results

This commit finds the correct offset for Information
Elements in S1G beacon frames so they can be reported in
scan results.

Signed-off-by: Thomas Pedersen <thomas@adapt-ip.com>
Link: https://lore.kernel.org/r/20200922022818.15855-8-thomas@adapt-ip.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Author: twpedersen

net/mac80211/ieee80211_i.h

@@ -1535,6 +1535,9 @@ struct ieee802_11_elems {
 	u8 dtim_count;
 	u8 dtim_period;
 	const struct ieee80211_addba_ext_ie *addba_ext_ie;
+	const struct ieee80211_s1g_cap *s1g_capab;
+	const struct ieee80211_s1g_oper_ie *s1g_oper;
+	const struct ieee80211_s1g_bcn_compat_ie *s1g_bcn_compat;
 
 	/* length of them, respectively */
 	u8 ext_capab_len;

net/mac80211/rx.c

@@ -4578,7 +4578,8 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 	ieee80211_verify_alignment(&rx);
 
 	if (unlikely(ieee80211_is_probe_resp(hdr->frame_control) ||
-		     ieee80211_is_beacon(hdr->frame_control)))
+		     ieee80211_is_beacon(hdr->frame_control) ||
+		     ieee80211_is_s1g_beacon(hdr->frame_control)))
 		ieee80211_scan_rx(local, skb);
 
 	if (ieee80211_is_data(fc)) {

net/mac80211/scan.c

@@ -146,7 +146,8 @@ ieee80211_bss_info_update(struct ieee80211_local *local,
 			  struct ieee80211_mgmt *mgmt, size_t len,
 			  struct ieee80211_channel *channel)
 {
-	bool beacon = ieee80211_is_beacon(mgmt->frame_control);
+	bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
+		      ieee80211_is_s1g_beacon(mgmt->frame_control);
 	struct cfg80211_bss *cbss, *non_tx_cbss;
 	struct ieee80211_bss *bss, *non_tx_bss;
 	struct cfg80211_inform_bss bss_meta = {
@@ -195,6 +196,11 @@ ieee80211_bss_info_update(struct ieee80211_local *local,
 		elements = mgmt->u.probe_resp.variable;
 		baselen = offsetof(struct ieee80211_mgmt,
 				   u.probe_resp.variable);
+	} else if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
+		struct ieee80211_ext *ext = (void *) mgmt;
+
+		baselen = offsetof(struct ieee80211_ext, u.s1g_beacon.variable);
+		elements = ext->u.s1g_beacon.variable;
 	} else {
 		baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
 		elements = mgmt->u.beacon.variable;
@@ -246,9 +252,12 @@ void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
 	struct ieee80211_bss *bss;
 	struct ieee80211_channel *channel;
 
-	if (skb->len < 24 ||
-	    (!ieee80211_is_probe_resp(mgmt->frame_control) &&
-	     !ieee80211_is_beacon(mgmt->frame_control)))
+	if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
+		if (skb->len < 15)
+			return;
+	} else if (skb->len < 24 ||
+		 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
+		  !ieee80211_is_beacon(mgmt->frame_control)))
 		return;
 
 	sdata1 = rcu_dereference(local->scan_sdata);

net/mac80211/util.c

@@ -1003,6 +1003,10 @@ _ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action,
 		case WLAN_EID_LINK_ID:
 		case WLAN_EID_BSS_MAX_IDLE_PERIOD:
 		case WLAN_EID_RSNX:
+		case WLAN_EID_S1G_BCN_COMPAT:
+		case WLAN_EID_S1G_CAPABILITIES:
+		case WLAN_EID_S1G_OPERATION:
+		case WLAN_EID_S1G_SHORT_BCN_INTERVAL:
 		/*
 		 * not listing WLAN_EID_CHANNEL_SWITCH_WRAPPER -- it seems possible
 		 * that if the content gets bigger it might be needed more than once
@@ -1288,6 +1292,24 @@ _ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action,
 								&crc : NULL,
 							  elem, elems);
 			break;
+		case WLAN_EID_S1G_CAPABILITIES:
+			if (elen == sizeof(*elems->s1g_capab))
+				elems->s1g_capab = (void *)pos;
+			else
+				elem_parse_failed = true;
+			break;
+		case WLAN_EID_S1G_OPERATION:
+			if (elen == sizeof(*elems->s1g_oper))
+				elems->s1g_oper = (void *)pos;
+			else
+				elem_parse_failed = true;
+			break;
+		case WLAN_EID_S1G_BCN_COMPAT:
+			if (elen == sizeof(*elems->s1g_bcn_compat))
+				elems->s1g_bcn_compat = (void *)pos;
+			else
+				elem_parse_failed = true;
+			break;
 		default:
 			break;
 		}