static void tb_ctl_rx_callback()

in ctl.c [427:501]

• 58 lines of code
• 18 McCabe index (conditional complexity)

static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame,
			       bool canceled)
{
	struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
	struct tb_cfg_request *req;
	__be32 crc32;

	if (canceled)
		return; /*
			 * ring is stopped, packet is referenced from
			 * ctl->rx_packets.
			 */

	if (frame->size < 4 || frame->size % 4 != 0) {
		tb_ctl_err(pkg->ctl, "RX: invalid size %#x, dropping packet\n",
			   frame->size);
		goto rx;
	}

	frame->size -= 4; /* remove checksum */
	crc32 = tb_crc(pkg->buffer, frame->size);
	be32_to_cpu_array(pkg->buffer, pkg->buffer, frame->size / 4);

	switch (frame->eof) {
	case TB_CFG_PKG_READ:
	case TB_CFG_PKG_WRITE:
	case TB_CFG_PKG_ERROR:
	case TB_CFG_PKG_OVERRIDE:
	case TB_CFG_PKG_RESET:
		if (*(__be32 *)(pkg->buffer + frame->size) != crc32) {
			tb_ctl_err(pkg->ctl,
				   "RX: checksum mismatch, dropping packet\n");
			goto rx;
		}
		if (tb_async_error(pkg)) {
			tb_ctl_handle_event(pkg->ctl, frame->eof,
					    pkg, frame->size);
			goto rx;
		}
		break;

	case TB_CFG_PKG_EVENT:
	case TB_CFG_PKG_XDOMAIN_RESP:
	case TB_CFG_PKG_XDOMAIN_REQ:
		if (*(__be32 *)(pkg->buffer + frame->size) != crc32) {
			tb_ctl_err(pkg->ctl,
				   "RX: checksum mismatch, dropping packet\n");
			goto rx;
		}
		fallthrough;
	case TB_CFG_PKG_ICM_EVENT:
		if (tb_ctl_handle_event(pkg->ctl, frame->eof, pkg, frame->size))
			goto rx;
		break;

	default:
		break;
	}

	/*
	 * The received packet will be processed only if there is an
	 * active request and that the packet is what is expected. This
	 * prevents packets such as replies coming after timeout has
	 * triggered from messing with the active requests.
	 */
	req = tb_cfg_request_find(pkg->ctl, pkg);
	if (req) {
		if (req->copy(req, pkg))
			schedule_work(&req->work);
		tb_cfg_request_put(req);
	}

rx:
	tb_ctl_rx_submit(pkg);
}