qcacmn: Introduce wlan_is_ie_valid()

In change "qcacld-3.0: Validate Scan Default IEs" in the qcacld-3.0
project (Change-Id: Ifd8739c96a9990f01ff159eb59a7e904f7b8c592) the
utility API hdd_is_ie_valid() was introduced. One review comment was
that this should be a converged API, so rename and relocate the API.

Change-Id: I8d2a520ea70645ab54b450de83452c0035653485
CRs-Fixed: 2169420

umac/cmn_services/utils/inc/wlan_utility.h

@@ -62,6 +62,21 @@ bool wlan_is_dsrc_channel(uint16_t center_freq);
  */
 uint8_t wlan_freq_to_chan(uint32_t freq);
 
+/**
+ * wlan_is_ie_valid() - Determine if an IE sequence is valid
+ * @ie: Pointer to the IE buffer
+ * @ie_len: Length of the IE buffer @ie
+ *
+ * This function validates that the IE sequence is valid by verifying
+ * that the sum of the lengths of the embedded elements match the
+ * length of the sequence.
+ *
+ * Note well that a 0-length IE sequence is considered valid.
+ *
+ * Return: true if the IE sequence is valid, false if it is invalid
+ */
+bool wlan_is_ie_valid(const uint8_t *ie, size_t ie_len);
+
 /**
  * wlan_get_ie_ptr_from_eid() - Find out ie from eid
  * @eid: element id

umac/cmn_services/utils/src/wlan_utility.c

@@ -72,6 +72,27 @@ uint8_t wlan_freq_to_chan(uint32_t freq)
 	return chan;
 }
 
+bool wlan_is_ie_valid(const uint8_t *ie, size_t ie_len)
+{
+	uint8_t elen;
+
+	while (ie_len) {
+		if (ie_len < 2)
+			return false;
+
+		elen = ie[1];
+		ie_len -= 2;
+		ie += 2;
+		if (elen > ie_len)
+			return false;
+
+		ie_len -= elen;
+		ie += elen;
+	}
+
+	return true;
+}
+
 static const uint8_t *wlan_get_ie_ptr_from_eid_n_oui(uint8_t eid,
 						     const uint8_t *oui,
 						     uint8_t oui_size,