[fc] Update ELS port IDs when receiving an ELS frame

The port ID assigned by the FLOGI response is implicit in the
destination ID used for the response (which will differ from the
source ID used for the corresponding request).

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/net/fcels.c

  */
 static int fc_els_rx ( struct fc_els *els,
 		       struct io_buffer *iobuf,
-		       struct xfer_metadata *meta __unused ) {
+		       struct xfer_metadata *meta ) {
 	struct fc_els_frame_common *frame = iobuf->data;
+	struct sockaddr_fc *src = ( ( struct sockaddr_fc * ) meta->src );
+	struct sockaddr_fc *dest = ( ( struct sockaddr_fc * ) meta->dest );
 	size_t len = iob_len ( iobuf );
 	int ( * rx ) ( struct fc_els *els, const void *data, size_t len );
 	int rc;
 		rc = -EINVAL;
 		goto done;
 	}
+	if ( ! src ) {
+		DBGC ( els, FCELS_FMT " received frame missing source "
+		       "address:\n", FCELS_ARGS ( els ) );
+		rc = -EINVAL;
+		goto done;
+	}
+	if ( ! dest ) {
+		DBGC ( els, FCELS_FMT " received frame missing destination "
+		       "address:\n", FCELS_ARGS ( els ) );
+		rc = -EINVAL;
+		goto done;
+	}
 
 	/* Check for rejection responses */
 	if ( fc_els_is_request ( els ) &&
 		goto done;
 	}
 
+	/* Update port IDs */
+	memcpy ( &els->port_id, &dest->sfc_port_id, sizeof ( els->port_id ) );
+	memcpy ( &els->peer_port_id, &src->sfc_port_id,
+		 sizeof ( els->peer_port_id ) );
+
 	/* Determine handler, if necessary */
 	if ( ! els->handler )
 		els->handler = fc_els_detect ( els, frame, len );
 	DBGC ( els, FCELS_FMT " has port %s\n", FCELS_ARGS ( els ),
 	       fc_ntoa ( &flogi->port_wwn ) );
 	if ( has_fabric ) {
-		DBGC ( els, FCELS_FMT " has fabric with local ID %s\n",
-		       FCELS_ARGS ( els ), fc_id_ntoa ( &els->port_id ) );
+		DBGC ( els, FCELS_FMT " has fabric with", FCELS_ARGS ( els ) );
+		DBGC ( els, " local ID %s\n", fc_id_ntoa ( &els->port_id ) );
 	} else {
 		DBGC ( els, FCELS_FMT " has point-to-point link\n",
 		       FCELS_ARGS ( els ) );