summaryrefslogtreecommitdiff
path: root/includes/ProxyTools.php
blob: 99cd65c54380a49505a22d7b72018f3028ed8896 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
<?php
/**
 * Functions for dealing with proxies
 *
 * @file
 */

/**
 * Extracts the XFF string from the request header
 * Checks first for "X-Forwarded-For", then "Client-ip"
 * Note: headers are spoofable
 * @return string
 */
function wfGetForwardedFor() {
	$apacheHeaders = function_exists( 'apache_request_headers' ) ? apache_request_headers() : null;
	if( is_array( $apacheHeaders ) ) {
		// More reliable than $_SERVER due to case and -/_ folding
		$set = array();
		foreach ( $apacheHeaders as $tempName => $tempValue ) {
			$set[ strtoupper( $tempName ) ] = $tempValue;
		}
		$index = strtoupper ( 'X-Forwarded-For' );
		$index2 = strtoupper ( 'Client-ip' );
	} else {
		// Subject to spoofing with headers like X_Forwarded_For
		$set = $_SERVER;
		$index = 'HTTP_X_FORWARDED_FOR';
		$index2 = 'CLIENT-IP';
	}

	#Try a couple of headers
	if( isset( $set[$index] ) ) {
		return $set[$index];
	} elseif( isset( $set[$index2] ) ) {
		return $set[$index2];
	} else {
		return null;
	}
}

/**
 * Returns the browser/OS data from the request header
 * Note: headers are spoofable
 *
 * @deprecated in 1.18; use $wgRequest->getHeader( 'User-Agent' ) instead.
 * @return string
 */
function wfGetAgent() {
	wfDeprecated( __FUNCTION__ );
	if( function_exists( 'apache_request_headers' ) ) {
		// More reliable than $_SERVER due to case and -/_ folding
		$set = array();
		foreach ( apache_request_headers() as $tempName => $tempValue ) {
			$set[ strtoupper( $tempName ) ] = $tempValue;
		}
		$index = strtoupper ( 'User-Agent' );
	} else {
		// Subject to spoofing with headers like X_Forwarded_For
		$set = $_SERVER;
		$index = 'HTTP_USER_AGENT';
	}
	if( isset( $set[$index] ) ) {
		return $set[$index];
	} else {
		return '';
	}
}

/**
 * Work out the IP address based on various globals
 * For trusted proxies, use the XFF client IP (first of the chain)
 * @return string
 */
function wfGetIP() {
	global $wgUsePrivateIPs, $wgCommandLineMode;
	static $ip = false;

	# Return cached result
	if ( !empty( $ip ) ) {
		return $ip;
	}

	/* collect the originating ips */
	# Client connecting to this webserver
	if ( isset( $_SERVER['REMOTE_ADDR'] ) ) {
		$ip = IP::canonicalize( $_SERVER['REMOTE_ADDR'] );
	} elseif( $wgCommandLineMode ) {
		$ip = '127.0.0.1';
	}

	# Append XFF
	$forwardedFor = wfGetForwardedFor();
	if ( $forwardedFor !== null ) {
		$ipchain = array_map( 'trim', explode( ',', $forwardedFor ) );
		$ipchain = array_reverse( $ipchain );
		if ( $ip ) {
			array_unshift( $ipchain, $ip );
		}

		# Step through XFF list and find the last address in the list which is a trusted server
		# Set $ip to the IP address given by that trusted server, unless the address is not sensible (e.g. private)
		foreach ( $ipchain as $i => $curIP ) {
			$curIP = IP::canonicalize( $curIP );
			if ( wfIsTrustedProxy( $curIP ) ) {
				if ( isset( $ipchain[$i + 1] ) ) {
					if( $wgUsePrivateIPs || IP::isPublic( $ipchain[$i + 1 ] ) ) {
						$ip = $ipchain[$i + 1];
					}
				}
			} else {
				break;
			}
		}
	}

	# Allow extensions to improve our guess
	wfRunHooks( 'GetIP', array( &$ip ) );

	if( !$ip ) {
		throw new MWException( "Unable to determine IP" );
	}

	wfDebug( "IP: $ip\n" );
	return $ip;
}

/**
 * Checks if an IP is a trusted proxy providor
 * Useful to tell if X-Fowarded-For data is possibly bogus
 * Squid cache servers for the site and AOL are whitelisted
 * @param $ip String
 * @return bool
 */
function wfIsTrustedProxy( $ip ) {
	global $wgSquidServers, $wgSquidServersNoPurge;

	$trusted = in_array( $ip, $wgSquidServers ) ||
		in_array( $ip, $wgSquidServersNoPurge );
	wfRunHooks( 'IsTrustedProxy', array( &$ip, &$trusted ) );
	return $trusted;
}

/**
 * Forks processes to scan the originating IP for an open proxy server
 * MemCached can be used to skip IPs that have already been scanned
 */
function wfProxyCheck() {
	global $wgBlockOpenProxies, $wgProxyPorts, $wgProxyScriptPath;
	global $wgMemc, $wgProxyMemcExpiry;
	global $wgProxyKey;

	if ( !$wgBlockOpenProxies ) {
		return;
	}

	$ip = wfGetIP();

	# Get MemCached key
	$mcKey = wfMemcKey( 'proxy', 'ip', $ip );
	$mcValue = $wgMemc->get( $mcKey );
	$skip = (bool)$mcValue;

	# Fork the processes
	if ( !$skip ) {
		$title = SpecialPage::getTitleFor( 'Blockme' );
		$iphash = md5( $ip . $wgProxyKey );
		$url = wfExpandUrl( $title->getFullURL( 'ip='.$iphash ), PROTO_HTTP );

		foreach ( $wgProxyPorts as $port ) {
			$params = implode( ' ', array(
						escapeshellarg( $wgProxyScriptPath ),
						escapeshellarg( $ip ),
						escapeshellarg( $port ),
						escapeshellarg( $url )
						));
			exec( "php $params >" . wfGetNull() . " 2>&1 &" );
		}
		# Set MemCached key
		$wgMemc->set( $mcKey, 1, $wgProxyMemcExpiry );
	}
}