From f563d230903210acc2336af58e422216b68ded76 Mon Sep 17 00:00:00 2001 From: Andrzej Pietrasiewicz Date: Tue, 3 Mar 2015 10:52:23 +0100 Subject: [PATCH] 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 Signed-off-by: Felipe Balbi --- drivers/usb/gadget/composite.c | 6 +++++- include/linux/usb/composite.h | 3 +++ 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c index 9fb92310fb2b..4d25e11b1f72 100644 --- a/drivers/usb/gadget/composite.c +++ b/drivers/usb/gadget/composite.c @@ -1758,6 +1758,10 @@ unknown: * take such requests too, if that's ever needed: to work * in config 0, etc. */ + list_for_each_entry(f, &cdev->config->functions, list) + if (f->req_match && f->req_match(f, ctrl)) + goto try_fun_setup; + f = NULL; switch (ctrl->bRequestType & USB_RECIP_MASK) { case USB_RECIP_INTERFACE: if (!cdev->config || intf >= MAX_CONFIG_INTERFACES) @@ -1775,7 +1779,7 @@ unknown: f = NULL; break; } - +try_fun_setup: if (f && f->setup) value = f->setup(f, ctrl); else { diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h index 3d87defcc527..2511469a9904 100644 --- a/include/linux/usb/composite.h +++ b/include/linux/usb/composite.h @@ -148,6 +148,7 @@ struct usb_os_desc_table { * @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 @@ struct usb_function { 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 *); -- 2.20.1