Imported Upstream version 5.1.0

1 files changed, 16 insertions, 2 deletions

diff --git a/src/libcharon/sa/ikev1/tasks/isakmp_natd.c b/src/libcharon/sa/ikev1/tasks/isakmp_natd.c
index 5a779ff62..fc6ac0771 100644
--- a/src/libcharon/sa/ikev1/tasks/isakmp_natd.c
+++ b/src/libcharon/sa/ikev1/tasks/isakmp_natd.c
@@ -97,6 +97,20 @@ struct private_isakmp_natd_t {
 };
 
 /**
+ * Check if UDP encapsulation has to be forced either by config or required
+ * by the kernel interface
+ */
+static bool force_encap(ike_cfg_t *ike_cfg)
+{
+	if (!ike_cfg->force_encap(ike_cfg))
+	{
+		return hydra->kernel_interface->get_features(hydra->kernel_interface) &
+					KERNEL_REQUIRE_UDP_ENCAPSULATION;
+	}
+	return TRUE;
+}
+
+/**
  * Get NAT-D payload type (RFC 3947 or RFC 3947 drafts).
  */
 static payload_type_t get_nat_d_payload_type(ike_sa_t *ike_sa)
@@ -183,7 +197,7 @@ static hash_payload_t *build_natd_payload(private_isakmp_natd_t *this, bool src,
 	chunk_t hash;
 
 	config = this->ike_sa->get_ike_cfg(this->ike_sa);
-	if (src && config->force_encap(config))
+	if (src && force_encap(config))
 	{
 		hash = generate_natd_hash_faked(this);
 	}
@@ -297,7 +311,7 @@ static void process_payloads(private_isakmp_natd_t *this, message_t *message)
 									!this->src_matched);
 		config = this->ike_sa->get_ike_cfg(this->ike_sa);
 		if (this->dst_matched && this->src_matched &&
-			config->force_encap(config))
+			force_encap(config))
 		{
 			this->ike_sa->set_condition(this->ike_sa, COND_NAT_FAKE, TRUE);
 		}