usb: gadget: composite: add req_match method to usb_function
Non-standard requests can encode the actual interface number in a
non-standard way. For example composite_setup() assumes
that it is w_index && 0xFF, but the printer function encodes the interface
number in a context-dependet way (either w_index or w_index >> 8).
This can lead to such requests being directed to wrong functions.
This patch adds req_match() method to usb_function. Its purpose is to
verify that a given request can be handled by a given function.
If any function within a configuration provides the method and it returns
true, then it is assumed that the right function is found.
If a function uses req_match(), it should try as hard as possible to
determine if the request is meant for it.
If no functions in a configuration provide req_match or none of them
returns true, then fall back to the usual approach.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index 3d87def..2511469 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -148,6 +148,7 @@
* @disable: (REQUIRED) Indicates the function should be disabled. Reasons
* include host resetting or reconfiguring the gadget, and disconnection.
* @setup: Used for interface-specific control requests.
+ * @req_match: Tests if a given class request can be handled by this function.
* @suspend: Notifies functions when the host stops sending USB traffic.
* @resume: Notifies functions when the host restarts USB traffic.
* @get_status: Returns function status as a reply to
@@ -213,6 +214,8 @@
void (*disable)(struct usb_function *);
int (*setup)(struct usb_function *,
const struct usb_ctrlrequest *);
+ bool (*req_match)(struct usb_function *,
+ const struct usb_ctrlrequest *);
void (*suspend)(struct usb_function *);
void (*resume)(struct usb_function *);