From: Mark Bergsma <mark@users.mediawiki.org>
Date: Wed, 6 Apr 2005 17:14:43 +0000 (+0000)
Subject: HTCP Multicast Squid purging support
X-Git-Tag: 1.5.0alpha1~381
X-Git-Url: http://git.cyclocoop.org/%28?a=commitdiff_plain;h=e2bf8490320c4a3bda8296fddee25be4257acffb;p=lhc%2Fweb%2Fwiklou.git

HTCP Multicast Squid purging support
Uses (UDP) HTCP packets to send 'CLR' (purge) requests to Squids,
using a multicast group address. Needs a patched Squid (Squid doesn't
support HTCP CLR):
http://www.nedworks.org/~mark/patches/squid-htcp-clr.diff
---

diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index da27ddaf88..fadfd72412 100644
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -662,6 +662,10 @@ $wgSquidServersNoPurge = array();
 /** Maximum number of titles to purge in any one client operation */
 $wgMaxSquidPurgeTitles = 400;
 
+/** HTCP multicast purging */
+$wgHTCPPort = 4827;
+$wgHTCPMulticastTTL = 1;
+# $wgHTCPMulticastAddress = "224.0.0.85";
 
 # Cookie settings:
 #
diff --git a/includes/SquidUpdate.php b/includes/SquidUpdate.php
index 294fca4e43..d971d0a63b 100644
--- a/includes/SquidUpdate.php
+++ b/includes/SquidUpdate.php
@@ -91,13 +91,16 @@ class SquidUpdate {
 	XXX report broken Squids per mail or log */
 
 	/* static */ function purge( $urlArr ) {
-		global  $wgSquidServers;
+		global $wgSquidServers, $wgHTCPMulticastAddress, $wgHTCPPort;
 
 		if ( $wgSquidServers == 'echo' ) {
 			echo implode("<br />\n", $urlArr);
 			return;
 		}
 
+		if ( $wgHTCPMulticastAddress && $wgHTCPPort )
+			SquidUpdate::HTCPPurge( $urlArr );
+
 		$fname = 'SquidUpdate::purge';
 		wfProfileIn( $fname );
 		
@@ -200,6 +203,59 @@ class SquidUpdate {
 		wfProfileOut( $fname );
 	}
 
+	/* static */ function HTCPPurge( $urlArr ) {
+		global $wgHTCPMulticastAddress, $wgHTCPMulticastTTL, $wgHTCPPort;
+		$fname = 'SquidUpdate::HTCPPurge';
+		wfProfileIn( $fname );
+
+		$htcpOpCLR = 4;                 // HTCP CLR
+
+		// FIXME PHP doesn't support these socket constants (include/linux/in.h)
+		define( "IPPROTO_IP", 0 );
+		define( "IP_MULTICAST_LOOP", 34 );
+		define( "IP_MULTICAST_TTL", 33 );
+
+		// pfsockopen doesn't work because we need set_sock_opt
+	        $conn = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
+		if ( $conn ) {
+			// Set socket options
+			socket_set_option( $conn, IPPROTO_IP, IP_MULTICAST_LOOP, 0 );
+			if ( $wgHTCPMulticastTTL != 1 )
+				socket_set_option( $conn, IPPROTO_IP, IP_MULTICAST_TTL,
+					$wgHTCPMulticastTTL );
+
+			foreach ( $urlArr as $url ) {
+				// Construct a minimal HTCP request diagram
+				// as per RFC 2756
+				// Opcode 'CLR', no response desired, no auth
+				$htcpTransID = rand();
+
+				$htcpSpecifier = pack( 'na4na*na8n',
+					4, 'NONE', strlen( $url ), $url,
+					8, 'HTTP/1.0', 0 );
+
+				$htcpDataLen = 8 + 2 + strlen( $htcpSpecifier );
+				$htcpLen = 4 + $htcpDataLen + 2;
+
+				// Note! Squid gets the bit order of the first
+				// word wrong, wrt the RFC. Apparently no other
+				// implementation exists, so adapt to Squid
+				$htcpPacket = pack( 'nxxnCxNxxa*n',
+					$htcpLen, $htcpDataLen, $htcpOpCLR,
+					$htcpTransID, $htcpSpecifier, 2);
+
+				// Send out
+				debug( "Purging URL $url via HTCP\n" );
+				socket_sendto( $conn, $htcpPacket, $htcpLen, 0,
+					$wgHTCPMulticastAddress, $wgHTCPPort );
+			}
+		} else {
+			$errstr = socket_strerror( socket_last_error() );
+			debug( "SquidUpdate::HTCPPurge(): Error opening UDP socket: $errstr\n" );
+		}
+		wfProfileOut( $fname );
+	}
+
 	function debug( $text ) {
 		global $wgDebugSquid;
 		if ( $wgDebugSquid ) {