Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit bd65f623 authored by Max Vozeler's avatar Max Vozeler Committed by Greg Kroah-Hartman
Browse files

staging: usbip: vhci: handle EAGAIN from SO_RCVTIMEO 



If there is a receive timeout without any active
requests, we can tell the connection was idle and
ignore the timeout.

If there are active requests for which we expect
to receive a reply we close the connection.

This makes it possible to set an upper bound on
the time a usbip device may be unresponsive.

This is a workaround for the lack of heart-beat
messages in the USBIP protocol.

Extending the protocol would break compatibility
with all previous stub versions, so this seems like
the lesser evil.

Signed-off-by: default avatarMax Vozeler <max@vozeler.com>
Tested-by: default avatarMark Wehby <MWehby@luxotticaRetail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 7e249c8b

drivers/staging/usbip/vhci_rx.c

+20 −1
Original line number Diff line number Diff line
@@ -193,6 +193,19 @@ static void vhci_recv_ret_unlink(struct vhci_device *vdev, 
	return;

}



static int vhci_priv_tx_empty(struct vhci_device *vdev)

{

	int empty = 0;



	spin_lock(&vdev->priv_lock);



	empty = list_empty(&vdev->priv_rx);



	spin_unlock(&vdev->priv_lock);



	return empty;

}



/* recv a pdu */

static void vhci_rx_pdu(struct usbip_device *ud)

{
@@ -210,8 +223,14 @@ static void vhci_rx_pdu(struct usbip_device *ud) 
	if (ret < 0) {

		if (ret == -ECONNRESET)

			usbip_uinfo("connection reset by peer\n");

		else if (ret != -ERESTARTSYS)

		else if (ret == -EAGAIN) {

			/* ignore if connection was idle */

			if (vhci_priv_tx_empty(vdev))

				return;

			usbip_uinfo("connection timed out with pending urbs\n");

		} else if (ret != -ERESTARTSYS)

			usbip_uinfo("xmit failed %d\n", ret);



		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);

		return;

	}