[PATCH 15/50] common: Support parsing link specific association request

[Andrei Otcheretianski]

From: Ilan Peer <ilan.peer at intel.com>

An association request in the context of an MLO connection can
contain an ML element that holds the per station profile for
the additional links negotiated. To support this, add a function
to parse the per station profile.

Signed-off-by: Ilan Peer <ilan.peer at intel.com>
Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski at intel.com>
---
 src/common/ieee802_11_common.c | 147 +++++++++++++++++++++++++++++++++
 src/common/ieee802_11_common.h |   4 +
 2 files changed, 151 insertions(+)

diff --git a/src/common/ieee802_11_common.c b/src/common/ieee802_11_common.c
index f55eddf62e..0941cb9afe 100644
--- a/src/common/ieee802_11_common.c
+++ b/src/common/ieee802_11_common.c
@@ -950,6 +950,153 @@ void ieee802_11_elems_clear_ext_ids(struct ieee802_11_elems *elems,
 }
 
 
+ParseRes ieee802_11_parse_link_assoc_req(const u8 *start, size_t len,
+					 struct ieee802_11_elems *elems,
+					 struct wpabuf *mlbuf,
+					 u8 link_id, int show_errors)
+{
+	struct ieee80211_eht_ml *ml;
+	const u8 *pos;
+	ParseRes res = ParseFailed;
+
+	pos = wpabuf_head(mlbuf);
+	len = wpabuf_len(mlbuf);
+
+	/* must have control and common info length */
+	if (len < sizeof(*ml) + 1 || len < sizeof(*ml) + pos[sizeof(*ml)])
+		goto out;
+
+	ml = (struct ieee80211_eht_ml *)pos;
+
+	/* As we are interested with the Per-Sta profile, ignore other types */
+	if ((le_to_host16(ml->ml_control) & MULTI_LINK_CONTROL_TYPE_MASK) !=
+	     MULTI_LINK_CONTROL_TYPE_BASIC)
+		goto out;
+
+	/* skip the common info */
+	len -= sizeof(*ml) + pos[sizeof(*ml)];
+	pos += sizeof(*ml) + pos[sizeof(*ml)];
+
+	while (len > 2) {
+		size_t sub_elem_len = *(pos + 1);
+		size_t sta_info_len;
+		u16 link_info_control;
+		const u8 *non_inherit;
+
+		wpa_printf(MSG_DEBUG,
+			   "MLD: sub element: len=%zu, sub_elem_len=%zu",
+			   len, sub_elem_len);
+
+		if (2 + sub_elem_len > len) {
+			if (show_errors)
+				wpa_printf(MSG_DEBUG,
+					   "MLD: error: len=%zu, sub_elem_len=%zu",
+					   len, sub_elem_len);
+			goto out;
+		}
+
+		if (*pos != 0) {
+			pos += 2 + sub_elem_len;
+			len -= 2 + sub_elem_len;
+			continue;
+		}
+
+		if (sub_elem_len < 3) {
+			if (show_errors)
+				wpa_printf(MSG_DEBUG,
+					   "MLD: error: sub_elem_len=%zu < 5",
+					   sub_elem_len);
+			goto out;
+		}
+
+		link_info_control = WPA_GET_LE16(pos + 2);
+		if ((link_info_control & BASIC_MLE_STA_CTRL_LINK_ID_MASK) !=
+		    link_id) {
+			pos += 2 + sub_elem_len;
+			len -= 2 + sub_elem_len;
+			continue;
+		}
+
+		sta_info_len = *(pos + 4);
+		if (sub_elem_len < sta_info_len + 3) {
+			if (show_errors)
+				wpa_printf(MSG_DEBUG,
+					   "MLD: error: sub_elem_len=%zu, sta_info_len=%zu",
+					   sub_elem_len, sta_info_len);
+			goto out;
+		}
+
+		pos += sta_info_len + 4;
+		sub_elem_len -= sta_info_len + 2;
+
+		if (sub_elem_len < 2) {
+			if (show_errors)
+				wpa_printf(MSG_DEBUG,
+					   "MLD: missing capability info");
+			goto out;
+		}
+
+		pos += 2;
+		sub_elem_len -= 2;
+
+		/* handle none inheritance */
+		non_inherit = get_ie_ext(pos, sub_elem_len,
+					 WLAN_EID_EXT_NON_INHERITANCE);
+		if (non_inherit && non_inherit[1] > 1) {
+			u8 non_inherit_len = non_inherit[1] - 1;
+
+			/*
+			 * Do not include the none inheritance element when
+			 * parsing below. It should be the last element in the
+			 * sub element.
+			 */
+			sub_elem_len -= 3 + non_inherit_len;
+
+			/* skip the ID, length and extension ID */
+			non_inherit += 3;
+
+			if (non_inherit_len < 1UL + non_inherit[0]) {
+				if (show_errors)
+					wpa_printf(MSG_DEBUG,
+						   "MLD: invalid inheritance");
+				goto out;
+			}
+
+			ieee802_11_elems_clear_ids(elems,
+						   &non_inherit[1],
+						   non_inherit[0]);
+
+			non_inherit_len -= 1 + non_inherit[0];
+			non_inherit += 1 + non_inherit[0];
+
+			if (non_inherit_len < 1UL + non_inherit[0]) {
+				if (show_errors)
+					wpa_printf(MSG_DEBUG,
+						   "MLD: invalid inheritance");
+				goto out;
+			}
+
+			ieee802_11_elems_clear_ext_ids(elems,
+						       &non_inherit[1],
+						       non_inherit[0]);
+		}
+
+		wpa_printf(MSG_DEBUG, "MLD: link: sub_elem_len=%zu",
+			   sub_elem_len);
+
+		if (sub_elem_len)
+			res = __ieee802_11_parse_elems(pos, sub_elem_len,
+						       elems, show_errors);
+		else
+			res = ParseOK;
+		break;
+	}
+
+out:
+	return res;
+}
+
+
 int ieee802_11_ie_count(const u8 *ies, size_t ies_len)
 {
 	const struct element *elem;
diff --git a/src/common/ieee802_11_common.h b/src/common/ieee802_11_common.h
index f4b17a55fb..949cab73d6 100644
--- a/src/common/ieee802_11_common.h
+++ b/src/common/ieee802_11_common.h
@@ -190,6 +190,10 @@ void ieee802_11_elems_clear_ids(struct ieee802_11_elems *elems,
 				const u8 *ids, size_t num);
 void ieee802_11_elems_clear_ext_ids(struct ieee802_11_elems *elems,
 				    const u8 *ids, size_t num);
+ParseRes ieee802_11_parse_link_assoc_req(const u8 *start, size_t len,
+					 struct ieee802_11_elems *elems,
+					 struct wpabuf *mlbuf,
+					 u8 link_id, int show_errors);
 int ieee802_11_ie_count(const u8 *ies, size_t ies_len);
 struct wpabuf * ieee802_11_vendor_ie_concat(const u8 *ies, size_t ies_len,
 					    u32 oui_type);
-- 
2.38.1