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: Stefan Koch <skoch@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Stefan Koch 2015-08-08 11:32:51 +02:00 committed by Greg Kroah-Hartman
parent 484ebaedec
commit 1d958bef45
3 changed files with 57 additions and 0 deletions

View file

@ -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.)

View file

@ -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);

View file

@ -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? */