add cluster_mcast_ttl option

Changes

@@ -3,6 +3,8 @@
 - Increase size of PPP buffers to MAXETHER.
 - Bug fixes for CLI ringbuffer and tunnel HELLO from Yuri.
 - Restart rather than halt BGP on receipt of CEASE (Dominique Rousseau).
+- Add cluster_mcast_ttl option to allow a cluster to span multiple
+  subnets (suggested by Tim Devries).
 
 * Mon Aug 29 2005 Brendan O'Dea <bod@optus.net> 2.1.4
 - Drop level of "Unexpected CHAP message" log.

Docs/manual.html

@@ -335,6 +335,10 @@ on <A HREF="#Clustering">Clustering</A> for more information.
 Interface for cluster packets (default: eth0).
 </LI>
 
+<LI><B>cluster_mcast_ttl</B> (int)<BR>
+TTL for multicast packets (default: 1).
+</LI>
+
 <LI><B>cluster_hb_interval</B> (int)<BR>
 Interval in tenths of a second between cluster heartbeat/pings.
 </LI>

Docs/startup-config.5

@@ -2,7 +2,7 @@
 .de Id
 .ds Dt \\$4 \\$5
 ..
-.Id $Id: startup-config.5,v 1.12 2005-07-31 10:04:14 bodea Exp $
+.Id $Id: startup-config.5,v 1.13 2005-09-02 23:59:56 bodea Exp $
 .TH STARTUP-CONFIG 5 "\*(Dt" L2TPNS "File Formats and Conventions"
 .SH NAME
 startup\-config \- configuration file for l2tpns
@@ -194,6 +194,9 @@ Multicast cluster address (default: 239.192.13.13).
 .B cluster_interface
 Interface for cluster packets (default: eth0).
 .TP
+.B cluster_mcast_ttl
+TTL for multicast packets (default: 1).
+.TP
 .B cluster_hb_interval
 Interval in tenths of a second between cluster heartbeat/pings.
 .TP

THANKS

@@ -18,3 +18,4 @@ Jordan Hrycaj              <jordan@mjh.teddy-net.com>
 Vladislav Bjelic           <vladislav@gmail.com>
 Alex Kiernan               <alex.kiernan@gmail.com>
 Dominique Rousseau         <d.rousseau@nnx.com>
+Tim Devries                <tdevries@northrock.bm>

cluster.c

@@ -1,6 +1,6 @@
 // L2TPNS Clustering Stuff
 
-char const *cvs_id_cluster = "$Id: cluster.c,v 1.45 2005-07-31 10:04:09 bodea Exp $";
+char const *cvs_id_cluster = "$Id: cluster.c,v 1.46 2005-09-02 23:59:56 bodea Exp $";
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -127,6 +127,15 @@ int cluster_init()
 	opt = 0;	// Turn off multicast loopback.
 	setsockopt(cluster_sockfd, IPPROTO_IP, IP_MULTICAST_LOOP, &opt, sizeof(opt));
 
+	if (config->cluster_mcast_ttl != 1)
+	{
+		uint8_t ttl = 0;
+		if (config->cluster_mcast_ttl > 0)
+			ttl = config->cluster_mcast_ttl < 256 ? config->cluster_mcast_ttl : 255;
+
+		setsockopt(cluster_sockfd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl));
+	}
+
 	if (setsockopt(cluster_sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0)
 	{
 		LOG(0, 0, 0, "Failed to setsockopt (join mcast group): %s\n", strerror(errno));

l2tpns.c

@@ -4,7 +4,7 @@
 // Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced
 // vim: sw=8 ts=8
 
-char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.127 2005-09-01 06:59:06 bodea Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.128 2005-09-02 23:59:56 bodea Exp $";
 
 #include <arpa/inet.h>
 #include <assert.h>
@@ -135,6 +135,7 @@ config_descriptt config_values[] = {
 	CONFIG("packet_limit", max_packets, INT),
 	CONFIG("cluster_address", cluster_address, IPv4),
 	CONFIG("cluster_interface", cluster_interface, STRING),
+	CONFIG("cluster_mcast_ttl", cluster_mcast_ttl, INT),
 	CONFIG("cluster_hb_interval", cluster_hb_interval, INT),
 	CONFIG("cluster_hb_timeout", cluster_hb_timeout, INT),
  	CONFIG("cluster_master_min_adv", cluster_master_min_adv, INT),
@@ -3469,6 +3470,7 @@ static void initdata(int optdebug, char *optconfig)
 	config->debug = optdebug;
 	config->num_tbfs = MAXTBFS;
 	config->rl_rate = 28; // 28kbps
+	config->cluster_mcast_ttl = 1;
  	config->cluster_master_min_adv = 1;
 	config->ppp_restart_time = 3;
 	config->ppp_max_configure = 10;

l2tpns.h

@@ -1,5 +1,5 @@
 // L2TPNS Global Stuff
-// $Id: l2tpns.h,v 1.86 2005-08-31 12:38:38 bodea Exp $
+// $Id: l2tpns.h,v 1.87 2005-09-02 23:59:56 bodea Exp $
 
 #ifndef __L2TPNS_H__
 #define __L2TPNS_H__
@@ -570,6 +570,7 @@ typedef struct
 	int		cluster_last_hb_ver;		// Heartbeat version last seen from master
 	int		cluster_num_changes;		// Number of changes queued.
 
+	int		cluster_mcast_ttl;		// TTL for multicast packets
 	int		cluster_hb_interval;		// How often to send a heartbeat.
 	int		cluster_hb_timeout;		// How many missed heartbeats trigger an election.
 	uint64_t	cluster_table_version;		// # state changes processed by cluster