Implemented IPsec policies restricted to given network interface

src/libcharon/config/child_cfg.c

@@ -138,6 +138,11 @@ struct private_child_cfg_t {
 	 */
 	uint32_t manual_prio;
 
+	/**
+	 * Optional restriction of IPsec policy to a given network interface
+	 */
+	char *interface;
+
 	/**
 	 * set up IPsec transport SA in MIPv6 proxy mode
 	 */
@@ -512,6 +517,12 @@ METHOD(child_cfg_t, get_manual_prio, uint32_t,
 	return this->manual_prio;
 }
 
+METHOD(child_cfg_t, get_interface, char*,
+	private_child_cfg_t *this)
+{
+	return this->interface;
+}
+
 METHOD(child_cfg_t, get_replay_window, uint32_t,
 	private_child_cfg_t *this)
 {
@@ -537,7 +548,7 @@ METHOD(child_cfg_t, install_policy, bool,
 }
 
 #define LT_PART_EQUALS(a, b) ({ a.life == b.life && a.rekey == b.rekey && a.jitter == b.jitter; })
-#define LIFETIME_EQUALS(a, b) ({  LT_PART_EQUALS(a.time, b.time) && LT_PART_EQUALS(a.bytes, b.bytes) && LT_PART_EQUALS(a.packets, b.packets); })
+#define LIFETIME_EQUALS(a, b) ({ LT_PART_EQUALS(a.time, b.time) && LT_PART_EQUALS(a.bytes, b.bytes) && LT_PART_EQUALS(a.packets, b.packets); })
 
 METHOD(child_cfg_t, equals, bool,
 	private_child_cfg_t *this, child_cfg_t *other_pub)
@@ -585,7 +596,8 @@ METHOD(child_cfg_t, equals, bool,
 		this->replay_window == other->replay_window &&
 		this->proxy_mode == other->proxy_mode &&
 		this->install_policy == other->install_policy &&
-		streq(this->updown, other->updown);
+		streq(this->updown, other->updown) &&
+		streq(this->interface, other->interface);
 }
 
 METHOD(child_cfg_t, get_ref, child_cfg_t*,
@@ -603,10 +615,8 @@ METHOD(child_cfg_t, destroy, void,
 		this->proposals->destroy_offset(this->proposals, offsetof(proposal_t, destroy));
 		this->my_ts->destroy_offset(this->my_ts, offsetof(traffic_selector_t, destroy));
 		this->other_ts->destroy_offset(this->other_ts, offsetof(traffic_selector_t, destroy));
-		if (this->updown)
-		{
-			free(this->updown);
-		}
+		free(this->updown);
+		free(this->interface);
 		free(this->name);
 		free(this);
 	}
@@ -641,6 +651,7 @@ child_cfg_t *child_cfg_create(char *name, child_cfg_create_t *data)
 			.get_mark = _get_mark,
 			.get_tfc = _get_tfc,
 			.get_manual_prio = _get_manual_prio,
+			.get_interface = _get_interface,
 			.get_replay_window = _get_replay_window,
 			.set_replay_window = _set_replay_window,
 			.use_proxy_mode = _use_proxy_mode,
@@ -665,6 +676,7 @@ child_cfg_t *child_cfg_create(char *name, child_cfg_create_t *data)
 		.use_ipcomp = data->ipcomp,
 		.tfc = data->tfc,
 		.manual_prio = data->priority,
+		.interface = strdupnull(data->interface),
 		.install_policy = !data->suppress_policies,
 		.refcount = 1,
 		.proposals = linked_list_create(),

src/libcharon/config/child_cfg.h

@@ -243,6 +243,13 @@ struct child_cfg_t {
 	 */
 	uint32_t (*get_manual_prio)(child_cfg_t *this);
 
+	/**
+	 * Get optional network interface restricting IPsec policy
+	 *
+	 * @return				network interface)
+	 */
+	char* (*get_interface)(child_cfg_t *this);
+
 	/**
 	 * Get anti-replay window size
 	 *
@@ -318,6 +325,8 @@ struct child_cfg_create_t {
 	uint32_t tfc;
 	/** Optional manually-set IPsec policy priority */
 	uint32_t priority;
+	/** Optional network interface restricting IPsec policy (cloned) */
+	char *interface;
 	/** lifetime_cfg_t for this child_cfg */
 	lifetime_cfg_t lifetime;
 	/** Inactivity timeout in s before closing a CHILD_SA */

src/libcharon/kernel/kernel_ipsec.h

@@ -69,6 +69,8 @@ struct kernel_ipsec_add_sa_t {
 	linked_list_t *src_ts;
 	/** List of destination traffic selectors */
 	linked_list_t *dst_ts;
+	/** Network interface restricting policy */
+	char *interface;
 	/** Lifetime configuration */
 	lifetime_cfg_t *lifetime;
 	/** Encryption algorithm */
@@ -142,6 +144,8 @@ struct kernel_ipsec_policy_id_t {
 	traffic_selector_t *dst_ts;
 	/** Optional mark */
 	mark_t mark;
+	/** Network interface restricting policy */
+	char *interface;
 };
 
 /**

src/libcharon/plugins/kernel_netlink/kernel_netlink_ipsec.c

@@ -26,6 +26,7 @@
 #include <linux/rtnetlink.h>
 #include <linux/xfrm.h>
 #include <linux/udp.h>
+#include <net/if.h>
 #include <unistd.h>
 #include <time.h>
 #include <errno.h>
@@ -739,7 +740,8 @@ static void ts2ports(traffic_selector_t* ts,
  * Convert a pair of traffic_selectors to an xfrm_selector
  */
 static struct xfrm_selector ts2selector(traffic_selector_t *src,
-										traffic_selector_t *dst)
+										traffic_selector_t *dst,
+										char *interface)
 {
 	struct xfrm_selector sel;
 	uint16_t port;
@@ -763,7 +765,7 @@ static struct xfrm_selector ts2selector(traffic_selector_t *src,
 		sel.dport = htons(traffic_selector_icmp_code(port));
 		sel.dport_mask = sel.dport ? ~0 : 0;
 	}
-	sel.ifindex = 0;
+	sel.ifindex = interface ? if_nametoindex(interface) : 0;
 	sel.user = 0;
 
 	return sel;
@@ -1279,7 +1281,8 @@ METHOD(kernel_ipsec_t, add_sa, status_t,
 				data->dst_ts->get_first(data->dst_ts,
 										(void**)&first_dst_ts) == SUCCESS)
 			{
-				sa->sel = ts2selector(first_src_ts, first_dst_ts);
+				sa->sel = ts2selector(first_src_ts, first_dst_ts,
+									  data->interface);
 				if (!this->proto_port_transport)
 				{
 					/* don't install proto/port on SA. This would break
@@ -2358,7 +2361,7 @@ METHOD(kernel_ipsec_t, add_policy, status_t,
 
 	/* create a policy */
 	INIT(policy,
-		.sel = ts2selector(id->src_ts, id->dst_ts),
+		.sel = ts2selector(id->src_ts, id->dst_ts, id->interface),
 		.mark = id->mark.value & id->mark.mask,
 		.direction = id->dir,
 		.reqid = data->sa->reqid,
@@ -2468,7 +2471,7 @@ METHOD(kernel_ipsec_t, query_policy, status_t,
 	hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_userpolicy_id));
 
 	policy_id = NLMSG_DATA(hdr);
-	policy_id->sel = ts2selector(id->src_ts, id->dst_ts);
+	policy_id->sel = ts2selector(id->src_ts, id->dst_ts, id->interface);
 	policy_id->dir = id->dir;
 
 	if (!add_mark(hdr, sizeof(request), id->mark))
@@ -2552,7 +2555,7 @@ METHOD(kernel_ipsec_t, del_policy, status_t,
 
 	/* create a policy */
 	memset(&policy, 0, sizeof(policy_entry_t));
-	policy.sel = ts2selector(id->src_ts, id->dst_ts);
+	policy.sel = ts2selector(id->src_ts, id->dst_ts, id->interface);
 	policy.mark = id->mark.value & id->mark.mask;
 	policy.direction = id->dir;
 

src/libcharon/plugins/vici/vici_config.c

@@ -462,6 +462,7 @@ static void log_child_data(child_data_t *data, char *name)
 	DBG2(DBG_CFG, "   reqid = %u", cfg->reqid);
 	DBG2(DBG_CFG, "   tfc = %d", cfg->tfc);
 	DBG2(DBG_CFG, "   priority = %d", cfg->priority);
+	DBG2(DBG_CFG, "   interface = %s", cfg->interface);
 	DBG2(DBG_CFG, "   mark_in = %u/%u",
 		 cfg->mark_in.value, cfg->mark_in.mask);
 	DBG2(DBG_CFG, "   mark_out = %u/%u",
@@ -484,6 +485,7 @@ static void free_child_data(child_data_t *data)
 	data->remote_ts->destroy_offset(data->remote_ts,
 									offsetof(traffic_selector_t, destroy));
 	free(data->cfg.updown);
+	free(data->cfg.interface);
 }
 
 /**
@@ -1342,6 +1344,7 @@ CALLBACK(child_kv, bool,
 		{ "mark_out",		parse_mark,			&child->cfg.mark_out				},
 		{ "tfc_padding",	parse_tfc,			&child->cfg.tfc						},
 		{ "priority",		parse_uint32,		&child->cfg.priority				},
+		{ "interface",		parse_string,		&child->cfg.interface				},
 	};
 
 	return parse_rules(rules, countof(rules), name, value,

src/libcharon/sa/child_sa.c

@@ -576,6 +576,7 @@ static bool update_usetime(private_child_sa_t *this, bool inbound)
 				.src_ts = my_ts,
 				.dst_ts = other_ts,
 				.mark = this->mark_out,
+				.interface = this->config->get_interface(this->config),
 			};
 			kernel_ipsec_query_policy_t query = {};
 
@@ -798,6 +799,7 @@ METHOD(child_sa_t, install, status_t,
 		.mode = this->mode,
 		.src_ts = src_ts,
 		.dst_ts = dst_ts,
+		.interface = inbound ? NULL : this->config->get_interface(this->config),
 		.lifetime = lifetime,
 		.enc_alg = enc_alg,
 		.enc_key = encr,
@@ -890,6 +892,7 @@ static status_t install_policies_internal(private_child_sa_t *this,
 		.src_ts = my_ts,
 		.dst_ts = other_ts,
 		.mark = this->mark_out,
+		.interface = this->config->get_interface(this->config),
 	}, in_id = {
 		.dir = POLICY_IN,
 		.src_ts = other_ts,
@@ -948,6 +951,7 @@ static void del_policies_internal(private_child_sa_t *this,
 		.src_ts = my_ts,
 		.dst_ts = other_ts,
 		.mark = this->mark_out,
+		.interface = this->config->get_interface(this->config),
 	}, in_id = {
 		.dir = POLICY_IN,
 		.src_ts = other_ts,

src/libcharon/sa/shunt_manager.c

@@ -68,6 +68,8 @@ static bool install_shunt_policy(child_cfg_t *child)
 	policy_type_t policy_type;
 	policy_priority_t policy_prio;
 	status_t status = SUCCESS;
+	uint32_t manual_prio;
+	char *interface;
 	ipsec_sa_cfg_t sa = { .mode = MODE_TRANSPORT };
 
 	switch (child->get_mode(child))
@@ -92,6 +94,9 @@ static bool install_shunt_policy(child_cfg_t *child)
 	other_ts_list = child->get_traffic_selectors(child, FALSE, NULL, hosts);
 	hosts->destroy(hosts);
 
+	manual_prio = child->get_manual_prio(child);
+	interface = child->get_interface(child);
+
 	/* enumerate pairs of traffic selectors */
 	e_my_ts = my_ts_list->create_enumerator(my_ts_list);
 	while (e_my_ts->enumerate(e_my_ts, &my_ts))
@@ -115,11 +120,12 @@ static bool install_shunt_policy(child_cfg_t *child)
 				.src_ts = my_ts,
 				.dst_ts = other_ts,
 				.mark = child->get_mark(child, FALSE),
+				.interface = interface,
 			};
 			kernel_ipsec_manage_policy_t policy = {
 				.type = policy_type,
 				.prio = policy_prio,
-				.manual_prio = child->get_manual_prio(child),
+				.manual_prio = manual_prio,
 				.src = host_any,
 				.dst = host_any,
 				.sa = &sa,
@@ -134,6 +140,7 @@ static bool install_shunt_policy(child_cfg_t *child)
 				.src_ts = other_ts,
 				.dst_ts = my_ts,
 				.mark = child->get_mark(child, TRUE),
+				.interface = interface,
 			};
 			status |= charon->kernel->add_policy(charon->kernel, &id, &policy);
 			/* install "inbound" forward policy */
@@ -215,6 +222,8 @@ static void uninstall_shunt_policy(child_cfg_t *child)
 	policy_type_t policy_type;
 	policy_priority_t policy_prio;
 	status_t status = SUCCESS;
+	uint32_t manual_prio;
+	char *interface;
 	ipsec_sa_cfg_t sa = { .mode = MODE_TRANSPORT };
 
 	switch (child->get_mode(child))
@@ -239,6 +248,9 @@ static void uninstall_shunt_policy(child_cfg_t *child)
 	other_ts_list = child->get_traffic_selectors(child, FALSE, NULL, hosts);
 	hosts->destroy(hosts);
 
+	manual_prio = child->get_manual_prio(child);
+	interface = child->get_interface(child);
+
 	/* enumerate pairs of traffic selectors */
 	e_my_ts = my_ts_list->create_enumerator(my_ts_list);
 	while (e_my_ts->enumerate(e_my_ts, &my_ts))
@@ -262,11 +274,12 @@ static void uninstall_shunt_policy(child_cfg_t *child)
 				.src_ts = my_ts,
 				.dst_ts = other_ts,
 				.mark = child->get_mark(child, FALSE),
+				.interface = interface,
 			};
 			kernel_ipsec_manage_policy_t policy = {
 				.type = policy_type,
 				.prio = policy_prio,
-				.manual_prio = child->get_manual_prio(child),
+				.manual_prio = manual_prio,
 				.src = host_any,
 				.dst = host_any,
 				.sa = &sa,
@@ -281,6 +294,7 @@ static void uninstall_shunt_policy(child_cfg_t *child)
 				.src_ts = other_ts,
 				.dst_ts = my_ts,
 				.mark = child->get_mark(child, TRUE),
+				.interface = interface,
 			};
 			status |= charon->kernel->del_policy(charon->kernel, &id, &policy);
 			/* uninstall "inbound" forward policy */

src/swanctl/swanctl.opt

@@ -691,6 +691,9 @@ connections.<conn>.children.<child>.priority = 0
 	high-priority drop policies.  The default of _0_ uses dynamically calculated
 	priorities based on the size of the traffic selectors.
 
+connections.<conn>.children.<child>.interface =
+	Optional interface name to restrict IPsec policies.
+
 connections.<conn>.children.<child>.mark_in = 0/0x00000000
 	Netfilter mark and mask for input traffic.