qcacmn: Handle non-inhertance IE scanning

The earlier logic for scanning non-inheritance IE fails if
non transmitted bssid profile has any extension element
such as MU EDCA before the extension element with
non-inheritance IE.

Since MU EDCA is also an extension element and it does not
have noninheritance element id in it, the logic used to fail
as the driver does not check further for any other extension
element ID in non transmitted bssid profile. Because of this
the IEs part of non-inheritance list used to get inherited,
causing disconnection issue.

With current fix, the scanning for non-inheritance IE has been
taken care properly. Driver will go through the non transmitted
bssid profile until it finds the extension element with
non-inheritance element ID in it.

Change-Id: Ib4346600a880a8390c6d023cf403ed18c62406d2
CRs-Fixed: 2935065

umac/scan/dispatcher/src/wlan_scan_utils_api.c

@@ -1875,6 +1875,37 @@ static bool util_is_noninh_ie(uint8_t elem_id,
 
 	return false;
 }
+
+/*
+ * util_scan_find_noninheritance_ie() - find noninheritance information element
+ * This block of code is to identify if there is any non-inheritance element
+ * present as part of the nontransmitted BSSID profile.
+ * @elem_id: element id
+ * @ies: pointer consisting of IEs
+ * @len: IE length
+ *
+ * Return: NULL if the element ID is not found or if IE pointer is NULL else
+ * pointer to the first byte of the requested element
+ */
+static uint8_t
+*util_scan_find_noninheritance_ie(uint8_t elem_id, uint8_t *ies,
+				  int32_t len)
+{
+	if (!ies)
+		return NULL;
+
+	while (len >= MIN_IE_LEN && len >= ies[TAG_LEN_POS] + MIN_IE_LEN) {
+		if ((ies[ID_POS] == elem_id) &&
+		    (ies[ELEM_ID_EXTN_POS] ==
+		     WLAN_EXTN_ELEMID_NONINHERITANCE)) {
+			return ies;
+		}
+		len -= ies[TAG_LEN_POS] + MIN_IE_LEN;
+		ies += ies[TAG_LEN_POS] + MIN_IE_LEN;
+	}
+
+	return NULL;
+}
 #endif
 
 /*
@@ -1920,11 +1951,10 @@ static void util_gen_new_bssid(uint8_t *bssid, uint8_t max_bssid,
 }
 
 /*
- * util_scan_noninheritance() - This block of code is to identify if
- * there is any non-inheritance element present as part of the nontransmitted
- * BSSID profile. If it is found then Host need not inherit those list of
- * element IDs and list of element ID extensions from the transmitted BSSID
- * profile.
+ * util_parse_noninheritance_list() - This block of code will be executed only
+ * if there is a valid non inheritance IE present in the nontx profile.
+ * Host need not inherit those list of element IDs and list of element ID
+ * extensions from the transmitted BSSID profile.
  * Since non-inheritance element is an element ID extension, it should
  * be part of extension element. So first we need to find if there are
  * any extension element present in the nontransmitted BSSID profile.
@@ -1953,15 +1983,14 @@ static void util_gen_new_bssid(uint8_t *bssid, uint8_t max_bssid,
  * @non_inheritance_ie: Non inheritance IE information
  */
 
-static void util_scan_noninheritance(uint8_t *extn_elem,
-				     uint8_t **elem_list,
-				     uint8_t **extn_elem_list,
-				     struct non_inheritance_ie *ninh)
+static void util_parse_noninheritance_list(uint8_t *extn_elem,
+					   uint8_t **elem_list,
+					   uint8_t **extn_elem_list,
+					   struct non_inheritance_ie *ninh)
 {
 	int8_t extn_rem_len = 0;
 
-	if ((extn_elem[ELEM_ID_EXTN_POS] == WLAN_EXTN_ELEMID_NONINHERITANCE) &&
-	    (extn_elem[ELEM_ID_LIST_LEN_POS] < extn_elem[TAG_LEN_POS])) {
+	if (extn_elem[ELEM_ID_LIST_LEN_POS] < extn_elem[TAG_LEN_POS]) {
 		/*
 		 * extn_rem_len represents the number of bytes after
 		 * the length subfield of list of Element IDs.
@@ -2070,12 +2099,12 @@ static uint32_t util_gen_new_ie(uint8_t *ie, uint32_t ielen,
 		}
 	}
 
-	extn_elem = util_scan_find_ie(WLAN_ELEMID_EXTN_ELEM,
-				      sub_copy, subie_len);
+	extn_elem = util_scan_find_noninheritance_ie(WLAN_ELEMID_EXTN_ELEM,
+						     sub_copy, subie_len);
 
 	if (extn_elem && extn_elem[TAG_LEN_POS]) {
-		util_scan_noninheritance(extn_elem, &elem_list,
-					 &extn_elem_list, &ninh);
+		util_parse_noninheritance_list(extn_elem, &elem_list,
+					       &extn_elem_list, &ninh);
 	}
 
 	/* go through IEs in ie (skip SSID) and subelement,