From: Guus Sliepen <guus@tinc-vpn.org>
Date: Tue, 2 Mar 2010 21:55:24 +0000 (+0100)
Subject: Add the DirectOnly option.
X-Git-Tag: import-tinc-1.1~558^2~5
X-Git-Url: https://git.meshlink.io/?a=commitdiff_plain;h=3e4829e78a3c7f7e19017d05611e5b69d5268119;p=meshlink

Add the DirectOnly option.

When this option is enabled, packets that cannot be sent directly to the destination node,
but which would have to be forwarded by an intermediate node, are dropped instead.
When combined with the IndirectData option,
packets for nodes for which we do not have a meta connection with are also dropped.
---

diff --git a/doc/tinc.conf.5.in b/doc/tinc.conf.5.in
index 797ca522..8f5237f7 100644
--- a/doc/tinc.conf.5.in
+++ b/doc/tinc.conf.5.in
@@ -199,6 +199,12 @@ Tinc will expect packets read from the virtual network device
 to start with an Ethernet header.
 .El
 
+.It Va DirectOnly Li = yes | no Pq no
+When this option is enabled, packets that cannot be sent directly to the destination node,
+but which would have to be forwarded by an intermediate node, are dropped instead.
+When combined with the IndirectData option,
+packets for nodes for which we do not have a meta connection with are also dropped.
+
 .It Va Forwarding Li = off | internal | kernel Pq internal
 This option selects the way indirect packets are forwarded.
 .Bl -tag -width indent
diff --git a/doc/tinc.texi b/doc/tinc.texi
index 091b5e7a..0ea421e3 100644
--- a/doc/tinc.texi
+++ b/doc/tinc.texi
@@ -818,6 +818,13 @@ Tinc will expect packets read from the virtual network device
 to start with an Ethernet header.
 @end table
 
+@cindex DirectOnly
+@item DirectOnly = <yes|no> (no)
+When this option is enabled, packets that cannot be sent directly to the destination node,
+but which would have to be forwarded by an intermediate node, are dropped instead.
+When combined with the IndirectData option,
+packets for nodes for which we do not have a meta connection with are also dropped.
+
 @cindex Forwarding
 @item Forwarding = <off|internal|kernel> (internal)
 This option selects the way indirect packets are forwarded.
diff --git a/src/net_setup.c b/src/net_setup.c
index 6e51b2e2..867fef94 100644
--- a/src/net_setup.c
+++ b/src/net_setup.c
@@ -339,6 +339,7 @@ bool setup_myself(void) {
 	if(myself->options & OPTION_TCPONLY)
 		myself->options |= OPTION_INDIRECT;
 
+	get_config_bool(lookup_config(config_tree, "DirectOnly"), &directonly);
 	get_config_bool(lookup_config(config_tree, "StrictSubnets"), &strictsubnets);
 	get_config_bool(lookup_config(config_tree, "TunnelServer"), &tunnelserver);
 	strictsubnets |= tunnelserver;
diff --git a/src/route.c b/src/route.c
index 1f91db97..4e7f7e58 100644
--- a/src/route.c
+++ b/src/route.c
@@ -34,6 +34,7 @@
 
 rmode_t routing_mode = RMODE_ROUTER;
 fmode_t forwarding_mode = FMODE_INTERNAL;
+bool directonly = false;
 bool priorityinheritance = false;
 int macexpire = 600;
 bool overwrite_mac = false;
@@ -394,6 +395,9 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) {
 
 	via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via;
 	
+	if(directonly && subnet->owner != via)
+		return route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+
 	if(via && packet->len > max(via->mtu, 590) && via != myself) {
 		ifdebug(TRAFFIC) logger(LOG_INFO, "Packet for %s (%s) length %d larger than MTU %d", subnet->owner->name, subnet->owner->hostname, packet->len, via->mtu);
 		if(packet->data[20] & 0x40) {
@@ -542,6 +546,9 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) {
 
 	via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via;
 	
+	if(directonly && subnet->owner != via)
+		return route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
+
 	if(via && packet->len > max(via->mtu, 1294) && via != myself) {
 		ifdebug(TRAFFIC) logger(LOG_INFO, "Packet for %s (%s) length %d larger than MTU %d", subnet->owner->name, subnet->owner->hostname, packet->len, via->mtu);
 		packet->len = max(via->mtu, 1294);
@@ -809,6 +816,9 @@ static void route_mac(node_t *source, vpn_packet_t *packet) {
 	// Handle packets larger than PMTU
 
 	node_t *via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via;
+
+	if(directonly && subnet->owner != via)
+		return;
 	
 	if(via && packet->len > via->mtu && via != myself) {
 		ifdebug(TRAFFIC) logger(LOG_INFO, "Packet for %s (%s) length %d larger than MTU %d", subnet->owner->name, subnet->owner->hostname, packet->len, via->mtu);
diff --git a/src/route.h b/src/route.h
index aa25dcf5..49431f20 100644
--- a/src/route.h
+++ b/src/route.h
@@ -38,6 +38,7 @@ typedef enum fmode_t {
 
 extern rmode_t routing_mode;
 extern fmode_t forwarding_mode;
+extern bool directonly;
 extern bool overwrite_mac;
 extern bool priorityinheritance;
 extern int macexpire;