From b30bf261f4601d0e029f64c858bb8d010ca5ca82 Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aaron@users.mediawiki.org>
Date: Sat, 21 Apr 2007 16:45:36 +0000
Subject: [PATCH] *Remove wfGetLastIPfromXFF(), add a new
 wfGetClientIPfromXFF(), which was removed in r21353

---
 includes/ProxyTools.php | 38 ++++++++++++++------------------------
 1 file changed, 14 insertions(+), 24 deletions(-)

diff --git a/includes/ProxyTools.php b/includes/ProxyTools.php
index 840c580e23..aaf2ee163e 100644
--- a/includes/ProxyTools.php
+++ b/includes/ProxyTools.php
@@ -26,32 +26,22 @@ function wfGetForwardedFor() {
 }
 
 /**
- * @todo FUCKING DOCUMENT THIS FUCKING FUNCTION
+ * Locates the client IP within a given XFF string
+ * @param string $xff
+ * @return string
  */
-function wfGetLastIPfromXFF( $xff ) {
-	if ( $xff ) {
-	// Avoid annoyingly long xff hacks
-		$xff = substr( $xff, 0, 255 );
-		// Look for the last IP, assuming they are separated by commas or spaces
-		$n = ( strrpos($xff, ',') ) ? strrpos($xff, ',') : strrpos($xff, ' ');
-		if ( $n !== false ) {
-			$last = trim( substr( $xff, $n + 1 ) );
-			// Make sure it is an IP
-			$m = preg_match('#^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$#', $last);
-			$n = preg_match('#^:(:[0-9A-Fa-f]{1,4}){1,7}|[0-9A-Fa-f]{1,4}(:{1,2}[0-9A-Fa-f]{1,4}|::$){1,7}$#', $last);
-			if ( $m > 0 )
-				$xff_ip = $last;
-			else if ( $n > 0 ) 
-				$xff_ip = $last;
-			else 
-				$xff_ip = null;
-		} else {
-			$xff_ip = null;
-		} 
-	} else {
-		$xff_ip = null;
+function wfGetClientIPfromXFF( $xff ) {
+	if ( !$xff ) return null;
+	$xff = substr( $xff, 0, 511 );
+	// Just look for the first IP match
+	// We might have a mix of IPv4/IPv6
+	if ( preg_match('#\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}|:(:[0-9A-Fa-f]{1,4}){1,7}|[0-9A-Fa-f]{1,4}(:{1,2}[0-9A-Fa-f]{1,4}|::$){1,7}#', $xff, $ip) ) {	 
+	   	// Check if the numbers are valid
+		if ( IP::isIPAddress($ip) )
+		   return $ip;
 	}
-	return $xff_ip;
+	
+	return null;
 }
 
 function wfGetAgent() {
-- 
2.20.1