mobike: try to keep existing source address before switching to another

src/charon/kernel/kernel_interface.c

@@ -160,9 +160,10 @@ static status_t del_policy(private_kernel_interface_t *this,
 /**
  * Implementation of kernel_interface_t.get_source_addr
  */
-static host_t *get_source_addr(private_kernel_interface_t *this, host_t *dest)
+static host_t *get_source_addr(private_kernel_interface_t *this,
+							   host_t *dest, host_t *src)
 {
-	return this->net->get_source_addr(this->net, dest);
+	return this->net->get_source_addr(this->net, dest, src);
 }
 
 /**
@@ -329,7 +330,7 @@ kernel_interface_t *kernel_interface_create()
 	this->public.query_policy = (status_t(*)(kernel_interface_t*,traffic_selector_t*,traffic_selector_t*,policy_dir_t,u_int32_t*))query_policy;
 	this->public.del_policy = (status_t(*)(kernel_interface_t*,traffic_selector_t*,traffic_selector_t*,policy_dir_t))del_policy;
 	
-	this->public.get_source_addr = (host_t*(*)(kernel_interface_t*, host_t *dest))get_source_addr;
+	this->public.get_source_addr = (host_t*(*)(kernel_interface_t*, host_t *dest, host_t *src))get_source_addr;
 	this->public.get_nexthop = (host_t*(*)(kernel_interface_t*, host_t *dest))get_nexthop;
 	this->public.get_interface = (char*(*)(kernel_interface_t*,host_t*))get_interface;
 	this->public.create_address_enumerator = (enumerator_t*(*)(kernel_interface_t*,bool,bool))create_address_enumerator;

src/charon/kernel/kernel_interface.h

@@ -235,11 +235,15 @@ struct kernel_interface_t {
 	 *
 	 * Does a route lookup to get the source address used to reach dest.
 	 * The returned host is allocated and must be destroyed.
+	 * An optional src address can be used to check if a route is available
+	 * for given source to dest.
 	 *
 	 * @param dest			target destination address
+	 * @param src			source address to check, or NULL
 	 * @return				outgoing source address, NULL if unreachable
 	 */
-	host_t* (*get_source_addr)(kernel_interface_t *this, host_t *dest);
+	host_t* (*get_source_addr)(kernel_interface_t *this,
+							   host_t *dest, host_t *src);
 	
 	/**
 	 * Get the next hop for a destination.

src/charon/kernel/kernel_net.h

@@ -42,11 +42,14 @@ struct kernel_net_t {
 	 *
 	 * Does a route lookup to get the source address used to reach dest.
 	 * The returned host is allocated and must be destroyed.
+	 * An optional src address can be used to check if a route is available
+	 * for given source to dest.
 	 *
 	 * @param dest			target destination address
+	 * @param src			source address to check, or NULL
 	 * @return				outgoing source address, NULL if unreachable
 	 */
-	host_t* (*get_source_addr)(kernel_net_t *this, host_t *dest);
+	host_t* (*get_source_addr)(kernel_net_t *this, host_t *dest, host_t *src);
 	
 	/**
 	 * Get the next hop for a destination.

src/charon/plugins/kernel_netlink/kernel_netlink_net.c

@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2008 Tobias Brunner
+ * Copyright (C) 2005-2008 Martin Willi
  * Hochschule fuer Technik Rapperswil
  *
  * This program is free software; you can redistribute it and/or modify it
@@ -720,7 +721,7 @@ static bool addr_in_subnet(chunk_t addr, chunk_t net, int net_len)
  * Get a route: If "nexthop", the nexthop is returned. source addr otherwise.
  */
 static host_t *get_route(private_kernel_netlink_net_t *this, host_t *dest,
-						 bool nexthop)
+						 bool nexthop, host_t *candidate)
 {
 	unsigned char request[NETLINK_BUFFER_SIZE];
 	struct nlmsghdr *hdr, *out, *current;
@@ -744,7 +745,12 @@ static host_t *get_route(private_kernel_netlink_net_t *this, host_t *dest,
 	
 	chunk = dest->get_address(dest);
 	netlink_add_attribute(hdr, RTA_DST, chunk, sizeof(request));
-			
+	if (candidate)
+	{
+		chunk = candidate->get_address(candidate);
+		netlink_add_attribute(hdr, RTA_PREFSRC, chunk, sizeof(request));
+	}
+	
 	if (this->socket->send(this->socket, hdr, &out, &len) != SUCCESS)
 	{
 		DBG1(DBG_KNL, "getting address to %H failed", dest);
@@ -878,9 +884,10 @@ static host_t *get_route(private_kernel_netlink_net_t *this, host_t *dest,
 /**
  * Implementation of kernel_net_t.get_source_addr.
  */
-static host_t* get_source_addr(private_kernel_netlink_net_t *this, host_t *dest)
+static host_t* get_source_addr(private_kernel_netlink_net_t *this,
+							   host_t *dest, host_t *src)
 {
-	return get_route(this, dest, FALSE);
+	return get_route(this, dest, FALSE, src);
 }
 
 /**
@@ -888,7 +895,7 @@ static host_t* get_source_addr(private_kernel_netlink_net_t *this, host_t *dest)
  */
 static host_t* get_nexthop(private_kernel_netlink_net_t *this, host_t *dest)
 {
-	return get_route(this, dest, TRUE);
+	return get_route(this, dest, TRUE, NULL);
 }
 
 /**
@@ -1284,7 +1291,7 @@ kernel_netlink_net_t *kernel_netlink_net_create()
 	/* public functions */
 	this->public.interface.get_interface = (char*(*)(kernel_net_t*,host_t*))get_interface_name;
 	this->public.interface.create_address_enumerator = (enumerator_t*(*)(kernel_net_t*,bool,bool))create_address_enumerator;
-	this->public.interface.get_source_addr = (host_t*(*)(kernel_net_t*, host_t *dest))get_source_addr;
+	this->public.interface.get_source_addr = (host_t*(*)(kernel_net_t*, host_t *dest, host_t *src))get_source_addr;
 	this->public.interface.get_nexthop = (host_t*(*)(kernel_net_t*, host_t *dest))get_nexthop;
 	this->public.interface.add_ip = (status_t(*)(kernel_net_t*,host_t*,host_t*)) add_ip;
 	this->public.interface.del_ip = (status_t(*)(kernel_net_t*,host_t*)) del_ip;

src/charon/sa/ike_sa.c

@@ -1098,7 +1098,7 @@ static void resolve_hosts(private_ike_sa_t *this)
 	{
 		host->destroy(host);
 		host = charon->kernel_interface->get_source_addr(
-								charon->kernel_interface, this->other_host);
+							charon->kernel_interface, this->other_host, NULL);
 		if (host)
 		{
 			host->set_port(host, IKEV2_UDP_PORT);
@@ -2206,7 +2206,7 @@ static void set_auth_lifetime(private_ike_sa_t *this, u_int32_t lifetime)
  */
 static status_t roam(private_ike_sa_t *this, bool address)
 {
-	host_t *me, *other;
+	host_t *src;
 	ike_mobike_t *mobike;
 	
 	switch (this->state)
@@ -2230,21 +2230,21 @@ static status_t roam(private_ike_sa_t *this, bool address)
 		return SUCCESS;
 	}
 	
-	/* get best address pair to use */
+	/* keep existing path if possible */
-	other = this->other_host;
+	src = charon->kernel_interface->get_source_addr(charon->kernel_interface,
-	me = charon->kernel_interface->get_source_addr(charon->kernel_interface,
+											this->other_host, this->my_host);
-												   other);
+	if (src)
-	
-	if (me)
 	{
-		if (me->ip_equals(me, this->my_host) &&
+		if (src->ip_equals(src, this->my_host))
-			other->ip_equals(other, this->other_host))
 		{
-			DBG2(DBG_IKE, "keeping connection path %H - %H", this->other_host, me);
+			DBG2(DBG_IKE, "keeping connection path %H - %H",
-			me->destroy(me);
+				 src, this->other_host);
+			src->destroy(src);
 			return SUCCESS;
 		}
-		me->destroy(me);
+		/* old address is not valid anymore, try with new one */
+		src->set_port(src, this->my_host->get_port(this->my_host));
+		set_my_host(this, src);
 	}
 	
 	/* update addresses with mobike, if supported ... */

src/charon/sa/tasks/ike_mobike.c

@@ -277,7 +277,7 @@ static void transmit(private_ike_mobike_t *this, packet_t *packet)
 	other_old = this->ike_sa->get_other_host(this->ike_sa);
 	
 	me = charon->kernel_interface->get_source_addr(
-										charon->kernel_interface, other_old);
+									charon->kernel_interface, other_old, NULL);
 	if (me)
 	{
 		me->set_port(me, me->ip_equals(me, me_old) ?
@@ -289,7 +289,7 @@ static void transmit(private_ike_mobike_t *this, packet_t *packet)
 	while (iterator->iterate(iterator, (void**)&other))
 	{
 		me = charon->kernel_interface->get_source_addr(
-											charon->kernel_interface, other);
+										charon->kernel_interface, other, NULL);
 		if (me)
 		{
 			if (me->get_family(me) != other->get_family(other))

src/charon/sa/tasks/ike_natd.c

@@ -341,9 +341,8 @@ static status_t build_i(private_ike_natd_t *this, message_t *message)
 	}
 	else
 	{
-		host = charon->kernel_interface->get_source_addr(
+		host = charon->kernel_interface->get_source_addr(charon->kernel_interface,
-									charon->kernel_interface,
+							this->ike_sa->get_other_host(this->ike_sa), NULL);
-									this->ike_sa->get_other_host(this->ike_sa));
 		if (host)
 		{	/* 2. */
 			host->set_port(host, IKEV2_UDP_PORT);