ikev2: Add a new state to track rekeyed IKE_SAs

This makes handling such IKE_SAs more specifically compared to keeping them
in state IKE_CONNECTING or IKE_ESTABLISHED (which we did when we lost a
collision - even triggering the ike_updown event), or using IKE_REKEYING for
them, which would also be ambiguous.

For instance, we can now reject anything but DELETES for such SAs.

src/libcharon/sa/ike_sa.c

@@ -71,6 +71,7 @@ ENUM(ike_sa_state_names, IKE_CREATED, IKE_DESTROYING,
 	"ESTABLISHED",
 	"PASSIVE",
 	"REKEYING",
+	"REKEYED",
 	"DELETING",
 	"DESTROYING",
 );
@@ -2356,7 +2357,8 @@ METHOD(ike_sa_t, retransmit, status_t,
 				reestablish(this);
 				break;
 		}
-		if (this->state != IKE_CONNECTING)
+		if (this->state != IKE_CONNECTING &&
+			this->state != IKE_REKEYED)
 		{
 			charon->bus->ike_updown(charon->bus, &this->public, FALSE);
 		}
@@ -2508,6 +2510,7 @@ METHOD(ike_sa_t, roam, status_t,
 		case IKE_DELETING:
 		case IKE_DESTROYING:
 		case IKE_PASSIVE:
+		case IKE_REKEYED:
 			return SUCCESS;
 		default:
 			break;