wifi: mac80211: add support for parsing TID to Link mapping element

Add the relevant definitions for TID to Link mapping element
according to the P802.11be_D4.0.

Signed-off-by: Ayala Beker <ayala.beker@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230920211508.9ea9b0b4412a.I2281ab2c70e8b43a39032dc115db6a80f1f0b3f4@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Author: AyalaBkr

include/linux/ieee80211.h

@@ -1246,6 +1246,30 @@ struct ieee80211_twt_setup {
 	u8 params[];
 } __packed;
 
+#define IEEE80211_TTLM_MAX_CNT				2
+#define IEEE80211_TTLM_CONTROL_DIRECTION		0x03
+#define IEEE80211_TTLM_CONTROL_DEF_LINK_MAP		0x04
+#define IEEE80211_TTLM_CONTROL_SWITCH_TIME_PRESENT	0x08
+#define IEEE80211_TTLM_CONTROL_EXPECTED_DUR_PRESENT	0x10
+#define IEEE80211_TTLM_CONTROL_LINK_MAP_SIZE		0x20
+
+#define IEEE80211_TTLM_DIRECTION_DOWN		0
+#define IEEE80211_TTLM_DIRECTION_UP		1
+#define IEEE80211_TTLM_DIRECTION_BOTH		2
+
+/**
+ * struct ieee80211_ttlm_elem - TID-To-Link Mapping element
+ *
+ * Defined in section 9.4.2.314 in P802.11be_D4
+ *
+ * @control: the first part of control field
+ * @optional: the second part of control field
+ */
+struct ieee80211_ttlm_elem {
+	u8 control;
+	u8 optional[];
+} __packed;
+
 struct ieee80211_mgmt {
 	__le16 frame_control;
 	__le16 duration;
@@ -3618,6 +3642,7 @@ enum ieee80211_eid_ext {
 	WLAN_EID_EXT_EHT_OPERATION = 106,
 	WLAN_EID_EXT_EHT_MULTI_LINK = 107,
 	WLAN_EID_EXT_EHT_CAPABILITY = 108,
+	WLAN_EID_EXT_TID_TO_LINK_MAPPING = 109,
 	WLAN_EID_EXT_BANDWIDTH_INDICATION = 135,
 };
 
@@ -5155,6 +5180,39 @@ static inline bool ieee80211_mle_reconf_sta_prof_size_ok(const u8 *data,
 	       fixed + prof->sta_info_len - 1 <= len;
 }
 
+static inline bool ieee80211_tid_to_link_map_size_ok(const u8 *data, size_t len)
+{
+	const struct ieee80211_ttlm_elem *t2l = (const void *)data;
+	u8 control, fixed = sizeof(*t2l), elem_len = 0;
+
+	if (len < fixed)
+		return false;
+
+	control = t2l->control;
+
+	if (control & IEEE80211_TTLM_CONTROL_SWITCH_TIME_PRESENT)
+		elem_len += 2;
+	if (control & IEEE80211_TTLM_CONTROL_EXPECTED_DUR_PRESENT)
+		elem_len += 3;
+
+	if (!(control & IEEE80211_TTLM_CONTROL_DEF_LINK_MAP)) {
+		u8 bm_size;
+
+		elem_len += 1;
+		if (len < fixed + elem_len)
+			return false;
+
+		if (control & IEEE80211_TTLM_CONTROL_LINK_MAP_SIZE)
+			bm_size = 1;
+		else
+			bm_size = 2;
+
+		elem_len += hweight8(t2l->optional[0]) * bm_size;
+	}
+
+	return len >= fixed + elem_len;
+}
+
 #define for_each_mle_subelement(_elem, _data, _len)			\
 	if (ieee80211_mle_size_ok(_data, _len))				\
 		for_each_element(_elem,					\

net/mac80211/ieee80211_i.h

@@ -1678,6 +1678,7 @@ struct ieee802_11_elems {
 	const struct ieee80211_multi_link_elem *ml_basic;
 	const struct ieee80211_multi_link_elem *ml_reconf;
 	const struct ieee80211_bandwidth_indication *bandwidth_indication;
+	const struct ieee80211_ttlm_elem *ttlm[IEEE80211_TTLM_MAX_CNT];
 
 	/* length of them, respectively */
 	u8 ext_capab_len;
@@ -1711,6 +1712,8 @@ struct ieee802_11_elems {
 	/* The reconfiguration Multi-Link element in the original IEs */
 	const struct element *ml_reconf_elem;
 
+	u8 ttlm_num;
+
 	/*
 	 * store the per station profile pointer and length in case that the
 	 * parsing also handled Multi-Link element parsing for a specific link

net/mac80211/util.c

@@ -995,6 +995,14 @@ ieee80211_parse_extension_element(u32 *crc,
 			elems->bandwidth_indication = data;
 		calc_crc = true;
 		break;
+	case WLAN_EID_EXT_TID_TO_LINK_MAPPING:
+		calc_crc = true;
+		if (ieee80211_tid_to_link_map_size_ok(data, len) &&
+		    elems->ttlm_num < ARRAY_SIZE(elems->ttlm)) {
+			elems->ttlm[elems->ttlm_num] = (void *)data;
+			elems->ttlm_num++;
+		}
+		break;
 	}
 
 	if (crc && calc_crc)