From 1d958bef45030acfc5578263e9de3bb07032b8da Mon Sep 17 00:00:00 2001 From: Stefan Koch Date: Sat, 8 Aug 2015 11:32:51 +0200 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hcd.c | 47 ++++++++++++++++++++++++++++++++++++++ drivers/usb/core/message.c | 1 + include/linux/usb/hcd.h | 9 ++++++++ 3 files changed, 57 insertions(+) diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 4d64e5c499e1..83df1dde9c08 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -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.) diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index f368d2053da5..3d25d89671d7 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1807,6 +1807,7 @@ free_interfaces: 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); diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h index d2784c10bfe2..36ce3d215cad 100644 --- a/include/linux/usb/hcd.h +++ b/include/linux/usb/hcd.h @@ -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? */