Optimize qa_block_ip_match

qa-include/app/limits.php

@@ -185,25 +185,33 @@ function qa_block_ips_explode($blockipstring)
  */
 function qa_block_ip_match($ip, $blockipclause)
 {
-	// check if the input parameters use the same IP version
-	if ((strpos($ip, ".") !== false && strpos($blockipclause, ".") === false) ||
-		(strpos($ip, ".") === false && strpos($blockipclause, ".") !== false)
-	) {
+	$ipv4 = filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4) !== false;
+	$blockipv4 = filter_var($blockipclause, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4) !== false;
+
+	// allow faster return if IP and blocked IP are plain IPv4 strings (IPv6 requires expanding)
+	if ($ipv4 && $blockipv4) {
+		return $ip === $blockipclause;
+	}
+
+	// check if same IP version
+	if (($ipv4 && !$blockipv4) || (!$ipv4 && $blockipv4)) {
 		return false;
 	}
 
 	if (filter_var($ip, FILTER_VALIDATE_IP)) {
 		if (preg_match('/^(.*)\-(.*)$/', $blockipclause, $matches)) {
+			// match IP range
 			if (filter_var($matches[1], FILTER_VALIDATE_IP) && filter_var($matches[2], FILTER_VALIDATE_IP)) {
 				return qa_ip_between($ip, $matches[1], $matches[2]);
 			}
 		} elseif (strlen($blockipclause)) {
+			// normalize IPv6 addresses
 			if (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6)) {
 				$ip = qa_ipv6_expand($ip);
 				$blockipclause = qa_ipv6_expand($blockipclause);
 			}
 
-			// preg_quote misses hyphens but that is OK here
+			// expand wildcards; preg_quote misses hyphens but that is OK here
 			return preg_match('/^' . str_replace('\\*', '([0-9A-Fa-f]+)', preg_quote($blockipclause, '/')) . '$/', $ip) > 0;
 		}
 	}