trap-manager: Add option to ignore traffic selectors from acquire events

The specific traffic selectors from the acquire events, which are derived
from the triggering packet, are usually prepended to those from the
config.  Some implementations might not be able to handle these properly.

References #860.

src/libcharon/sa/trap_manager.c

@@ -65,6 +65,11 @@ struct private_trap_manager_t {
 	 * listener to track acquiring IKE_SAs
 	 */
 	trap_listener_t listener;
+
+	/**
+	 * Whether to ignore traffic selectors from acquires
+	 */
+	bool ignore_acquire_ts;
 };
 
 /**
@@ -353,7 +358,7 @@ METHOD(trap_manager_t, acquire, void,
 		{
 			ike_sa->set_peer_cfg(ike_sa, peer);
 		}
-		if (ike_sa->get_version(ike_sa) == IKEV1)
+		if (this->ignore_acquire_ts || ike_sa->get_version(ike_sa) == IKEV1)
 		{	/* in IKEv1, don't prepend the acquiring packet TS, as we only
 			 * have a single TS that we can establish in a Quick Mode. */
 			src = dst = NULL;
@@ -484,6 +489,8 @@ trap_manager_t *trap_manager_create(void)
 		},
 		.traps = linked_list_create(),
 		.lock = rwlock_create(RWLOCK_TYPE_DEFAULT),
+		.ignore_acquire_ts = lib->settings->get_bool(lib->settings,
+										"%s.ignore_acquire_ts", FALSE, lib->ns),
 	);
 	charon->bus->add_listener(charon->bus, &this->listener.listener);