Commit 4656d5de authored by David Vrabel's avatar David Vrabel
Browse files

wusb: reset WUSB devices with SetAddress(0) 



Using a Reset Device IE to reset a WUSB device is too heavyweight as it
causes the devcie to disconnect (which the USB stack does not expect and
cannot handle).  Instead, do a SetAddress(0); SetAddress(AuthAddr) for
authenticated devices.

Unauthenticated devices will not be reset and the stack will have to rely
on the device timing out after TrustTimeout and disconnecting.

Signed-off-by: default avatarDavid Vrabel <david.vrabel@csr.com>
parent 1cde7f68

drivers/usb/wusbcore/devconnect.c

+1 −99
Original line number Diff line number Diff line
@@ -57,9 +57,6 @@ 
 *                              Called by notif.c:wusb_handle_dn_connect()

 *                              when a DN_Connect is received.

 *

 *   wusbhc_devconnect_auth()   Called by rh.c:wusbhc_rh_port_reset() when

 *                              doing the device connect sequence.

 *

 *     wusb_devconnect_acked()  Ack done, release resources.

 *

 *   wusb_handle_dn_alive()     Called by notif.c:wusb_handle_dn()
@@ -69,9 +66,6 @@ 
 *                              process a disconenct request from a

 *                              device.

 *

 *   wusb_dev_reset()           Called by rh.c:wusbhc_rh_port_reset() when

 *                              resetting a device.

 *

 *   __wusb_dev_disable()       Called by rh.c:wusbhc_rh_clear_port_feat() when

 *                              disabling a port.

 *
@@ -366,12 +360,10 @@ void wusbhc_devconnect_ack(struct wusbhc *wusbhc, struct wusb_dn_connect *dnc, 
	port->wusb_dev = wusb_dev;

	port->status |= USB_PORT_STAT_CONNECTION;

	port->change |= USB_PORT_STAT_C_CONNECTION;

	port->reset_count = 0;

	/* Now the port status changed to connected; khubd will

	 * pick the change up and try to reset the port to bring it to

	 * the enabled state--so this process returns up to the stack

	 * and it calls back into wusbhc_rh_port_reset() who will call

	 * devconnect_auth().

	 * and it calls back into wusbhc_rh_port_reset().

	 */

error_unlock:

	mutex_unlock(&wusbhc->mutex);
@@ -413,9 +405,6 @@ static void __wusbhc_dev_disconnect(struct wusbhc *wusbhc, 
		wusb_dev_put(wusb_dev);

	}

	port->wusb_dev = NULL;

	/* don't reset the reset_count to zero or wusbhc_rh_port_reset will get

	 * confused! We only reset to zero when we connect a new device.

	 */



	/* After a device disconnects, change the GTK (see [WUSB]

	 * section 6.2.11.2). */
@@ -428,39 +417,6 @@ static void __wusbhc_dev_disconnect(struct wusbhc *wusbhc, 
	 */

}



/*

 * Authenticate a device into the WUSB Cluster

 *

 * Called from the Root Hub code (rh.c:wusbhc_rh_port_reset()) when

 * asking for a reset on a port that is not enabled (ie: first connect

 * on the port).

 *

 * Performs the 4way handshake to allow the device to comunicate w/ the

 * WUSB Cluster securely; once done, issue a request to the device for

 * it to change to address 0.

 *

 * This mimics the reset step of Wired USB that once resetting a

 * device, leaves the port in enabled state and the dev with the

 * default address (0).

 *

 * WUSB1.0[7.1.2]

 *

 * @port_idx: port where the change happened--This is the index into

 *            the wusbhc port array, not the USB port number.

 */

int wusbhc_devconnect_auth(struct wusbhc *wusbhc, u8 port_idx)

{

	struct device *dev = wusbhc->dev;

	struct wusb_port *port = wusb_port_by_idx(wusbhc, port_idx);



	d_fnstart(3, dev, "(%p, %u)\n", wusbhc, port_idx);

	port->status &= ~USB_PORT_STAT_RESET;

	port->status |= USB_PORT_STAT_ENABLE;

	port->change |= USB_PORT_STAT_C_RESET | USB_PORT_STAT_C_ENABLE;

	d_fnend(3, dev, "(%p, %u) = 0\n", wusbhc, port_idx);

	return 0;

}



/*

 * Refresh the list of keep alives to emit in the MMC

 *
@@ -661,60 +617,6 @@ static void wusbhc_handle_dn_disconnect(struct wusbhc *wusbhc, struct wusb_dev * 
	mutex_unlock(&wusbhc->mutex);

}



/*

 * Reset a WUSB device on a HWA

 *

 * @wusbhc

 * @port_idx   Index of the port where the device is

 *

 * In Wireless USB, a reset is more or less equivalent to a full

 * disconnect; so we just do a full disconnect and send the device a

 * Device Reset IE (WUSB1.0[7.5.11]) giving it a few millisecs (6 MMCs).

 *

 * @wusbhc should be refcounted and unlocked

 */

int wusbhc_dev_reset(struct wusbhc *wusbhc, u8 port_idx)

{

	int result;

	struct device *dev = wusbhc->dev;

	struct wusb_dev *wusb_dev;

	struct wuie_reset *ie;



	d_fnstart(3, dev, "(%p, %u)\n", wusbhc, port_idx);

	mutex_lock(&wusbhc->mutex);

	result = 0;

	wusb_dev = wusb_port_by_idx(wusbhc, port_idx)->wusb_dev;

	if (wusb_dev == NULL) {

		/* reset no device? ignore */

		dev_dbg(dev, "RESET: no device at port %u, ignoring\n",

			port_idx);

		goto error_unlock;

	}

	result = -ENOMEM;

	ie = kzalloc(sizeof(*ie), GFP_KERNEL);

	if (ie == NULL)

		goto error_unlock;

	ie->hdr.bLength = sizeof(ie->hdr) + sizeof(ie->CDID);

	ie->hdr.bIEIdentifier = WUIE_ID_RESET_DEVICE;

	ie->CDID = wusb_dev->cdid;

	result = wusbhc_mmcie_set(wusbhc, 0xff, 6, &ie->hdr);

	if (result < 0) {

		dev_err(dev, "RESET: cant's set MMC: %d\n", result);

		goto error_kfree;

	}

	__wusbhc_dev_disconnect(wusbhc, wusb_port_by_idx(wusbhc, port_idx));



	/* 120ms, hopefully 6 MMCs (FIXME) */

	msleep(120);

	wusbhc_mmcie_rm(wusbhc, &ie->hdr);

error_kfree:

	kfree(ie);

error_unlock:

	mutex_unlock(&wusbhc->mutex);

	d_fnend(3, dev, "(%p, %u) = %d\n", wusbhc, port_idx, result);

	return result;

}



/*

 * Handle a Device Notification coming a host

 *

drivers/usb/wusbcore/rh.c

+22 −18
Original line number Diff line number Diff line
@@ -77,13 +77,17 @@ 
/*

 * Reset a fake port

 *

 * This can be called to reset a port from any other state or to reset

 * it when connecting. In Wireless USB they are different; when doing

 * a new connect that involves going over the authentication. When

 * just reseting, its a different story.

 * Using a Reset Device IE is too heavyweight as it causes the device

 * to enter the UnConnected state and leave the cluster, this can mean

 * that when the device reconnects it is connected to a different fake

 * port.

 *

 * The Linux USB stack resets a port twice before it considers it

 * enabled, so we have to detect and ignore that.

 * Instead, reset authenticated devices with a SetAddress(0), followed

 * by a SetAddresss(AuthAddr).

 *

 * For unauthenticated devices just pretend to reset but do nothing.

 * If the device initialization continues to fail it will eventually

 * time out after TrustTimeout and enter the UnConnected state.

 *

 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.

 *
@@ -97,20 +101,20 @@ static int wusbhc_rh_port_reset(struct wusbhc *wusbhc, u8 port_idx) 
{

	int result = 0;

	struct wusb_port *port = wusb_port_by_idx(wusbhc, port_idx);

	struct wusb_dev *wusb_dev = port->wusb_dev;



	port->status |= USB_PORT_STAT_RESET;

	port->change |= USB_PORT_STAT_C_RESET;



	d_fnstart(3, wusbhc->dev, "(wusbhc %p port_idx %u)\n",

		  wusbhc, port_idx);

	if (port->reset_count == 0) {

		wusbhc_devconnect_auth(wusbhc, port_idx);

		port->reset_count++;

	} else if (port->reset_count == 1)

		/* see header */

		d_printf(2, wusbhc->dev, "Ignoring second reset on port_idx "

			"%u\n", port_idx);

	if (wusb_dev->addr & WUSB_DEV_ADDR_UNAUTH)

		result = 0;

	else

		result = wusbhc_dev_reset(wusbhc, port_idx);

	d_fnend(3, wusbhc->dev, "(wusbhc %p port_idx %u) = %d\n",

		wusbhc, port_idx, result);

		result = wusb_dev_update_address(wusbhc, wusb_dev);



	port->status &= ~USB_PORT_STAT_RESET;

	port->status |= USB_PORT_STAT_ENABLE;

	port->change |= USB_PORT_STAT_C_RESET | USB_PORT_STAT_C_ENABLE;	



	return result;

}

drivers/usb/wusbcore/security.c

+1 −2
Original line number Diff line number Diff line
@@ -338,8 +338,7 @@ static void hs_printk(unsigned level, struct device *dev, 
 * Before the device's address (as known by it) was usb_dev->devnum |

 * 0x80 (unauthenticated address). With this we update it to usb_dev->devnum.

 */

static int wusb_dev_update_address(struct wusbhc *wusbhc,

				   struct wusb_dev *wusb_dev)

int wusb_dev_update_address(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev)

{

	int result = -ENOMEM;

	struct usb_device *usb_dev = wusb_dev->usb_dev;

drivers/usb/wusbcore/wusbhc.h

+1 −3
Original line number Diff line number Diff line
@@ -154,7 +154,6 @@ struct wusb_port { 
	u16 status;

	u16 change;

	struct wusb_dev *wusb_dev;	/* connected device's info */

	unsigned reset_count;

	u32 ptk_tkid;

};
@@ -387,10 +386,8 @@ extern void wusbhc_devconnect_destroy(struct wusbhc *); 
extern int wusbhc_devconnect_start(struct wusbhc *wusbhc,

				   const struct wusb_ckhdid *chid);

extern void wusbhc_devconnect_stop(struct wusbhc *wusbhc);

extern int wusbhc_devconnect_auth(struct wusbhc *, u8);

extern void wusbhc_handle_dn(struct wusbhc *, u8 srcaddr,

			     struct wusb_dn_hdr *dn_hdr, size_t size);

extern int wusbhc_dev_reset(struct wusbhc *wusbhc, u8 port);

extern void __wusbhc_dev_disable(struct wusbhc *wusbhc, u8 port);

extern int wusb_usb_ncb(struct notifier_block *nb, unsigned long val,

			void *priv);
@@ -436,6 +433,7 @@ extern void wusb_dev_sec_rm(struct wusb_dev *) ; 
extern int wusb_dev_4way_handshake(struct wusbhc *, struct wusb_dev *,

				   struct wusb_ckhdid *ck);

void wusbhc_gtk_rekey(struct wusbhc *wusbhc);

int wusb_dev_update_address(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev);





/* WUSB Cluster ID handling */

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