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Commit 6b2bd3c8 authored by Stefan Koch's avatar Stefan Koch Committed by Greg Kroah-Hartman
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usb: interface authorization: Introduces the default interface authorization 



Interfaces are allowed per default.
This can disabled or enabled (again) by writing 0 or 1 to
/sys/bus/usb/devices/usbX/interface_authorized_default

Signed-off-by: default avatarStefan Koch <stefan.koch10@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4ad2ddce

drivers/usb/core/hcd.c

+47 −0
Original line number Diff line number Diff line
@@ -882,9 +882,53 @@ static ssize_t authorized_default_store(struct device *dev, 
}

static DEVICE_ATTR_RW(authorized_default);



/*

 * interface_authorized_default_show - show default authorization status

 * for USB interfaces

 *

 * note: interface_authorized_default is the default value

 *       for initializing the authorized attribute of interfaces

 */

static ssize_t interface_authorized_default_show(struct device *dev,

		struct device_attribute *attr, char *buf)

{

	struct usb_device *usb_dev = to_usb_device(dev);

	struct usb_hcd *hcd = bus_to_hcd(usb_dev->bus);



	return sprintf(buf, "%u\n", !!HCD_INTF_AUTHORIZED(hcd));

}



/*

 * interface_authorized_default_store - store default authorization status

 * for USB interfaces

 *

 * note: interface_authorized_default is the default value

 *       for initializing the authorized attribute of interfaces

 */

static ssize_t interface_authorized_default_store(struct device *dev,

		struct device_attribute *attr, const char *buf, size_t count)

{

	struct usb_device *usb_dev = to_usb_device(dev);

	struct usb_hcd *hcd = bus_to_hcd(usb_dev->bus);

	int rc = count;

	bool val;



	if (strtobool(buf, &val) != 0)

		return -EINVAL;



	if (val)

		set_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);

	else

		clear_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);



	return rc;

}

static DEVICE_ATTR_RW(interface_authorized_default);



/* Group all the USB bus attributes */

static struct attribute *usb_bus_attrs[] = {

		&dev_attr_authorized_default.attr,

		&dev_attr_interface_authorized_default.attr,

		NULL,

};
@@ -2682,6 +2726,9 @@ int usb_add_hcd(struct usb_hcd *hcd, 
		hcd->authorized_default = authorized_default;

	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);



	/* per default all interfaces are authorized */

	set_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);



	/* HC is in reset state, but accessible.  Now do the one-time init,

	 * bottom up so that hcds can customize the root hubs before hub_wq

	 * starts talking to them.  (Note, bus id is assigned early too.)

drivers/usb/core/message.c

+1 −0
Original line number Diff line number Diff line
@@ -1807,6 +1807,7 @@ int usb_set_configuration(struct usb_device *dev, int configuration) 
		intfc = cp->intf_cache[i];

		intf->altsetting = intfc->altsetting;

		intf->num_altsetting = intfc->num_altsetting;

		intf->authorized = !!HCD_INTF_AUTHORIZED(hcd);

		kref_get(&intfc->ref);



		alt = usb_altnum_to_altsetting(intf, 0);

include/linux/usb/hcd.h

+9 −0
Original line number Diff line number Diff line
@@ -120,6 +120,7 @@ struct usb_hcd { 
#define HCD_FLAG_WAKEUP_PENDING		4	/* root hub is resuming? */

#define HCD_FLAG_RH_RUNNING		5	/* root hub is running? */

#define HCD_FLAG_DEAD			6	/* controller has died? */

#define HCD_FLAG_INTF_AUTHORIZED	7	/* authorize interfaces? */



	/* The flags can be tested using these macros; they are likely to

	 * be slightly faster than test_bit().
@@ -131,6 +132,14 @@ struct usb_hcd { 
#define HCD_RH_RUNNING(hcd)	((hcd)->flags & (1U << HCD_FLAG_RH_RUNNING))

#define HCD_DEAD(hcd)		((hcd)->flags & (1U << HCD_FLAG_DEAD))



	/*

	 * Specifies if interfaces are authorized by default

	 * or they require explicit user space authorization; this bit is

	 * settable through /sys/class/usb_host/X/interface_authorized_default

	 */

#define HCD_INTF_AUTHORIZED(hcd) \

	((hcd)->flags & (1U << HCD_FLAG_INTF_AUTHORIZED))



	/* Flags that get set only during HCD registration or removal. */

	unsigned		rh_registered:1;/* is root hub registered? */

	unsigned		rh_pollable:1;	/* may we poll the root hub? */