From cc8e3c5a4b4b68f13c55b2317e90acfa6aae1dbc Mon Sep 17 00:00:00 2001
From: Brion Vibber <brion@users.mediawiki.org>
Date: Tue, 24 Apr 2007 14:31:52 +0000
Subject: [PATCH] Reverting more fucked up untested code from r21448 and r21449

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

diff --git a/includes/ProxyTools.php b/includes/ProxyTools.php
index ad5b22c794..eff02682e8 100644
--- a/includes/ProxyTools.php
+++ b/includes/ProxyTools.php
@@ -32,22 +32,32 @@ function wfGetForwardedFor() {
 }
 
 /**
- * Locates the client IP within a given XFF string
- * @param string $xff
- * @return string
+ * @todo FUCKING DOCUMENT THIS FUCKING FUNCTION
  */
-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;
+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;
 	}
-	
-	return null;
+	return $xff_ip;
 }
 
 /**
-- 
2.20.1