From 17309a6a43561bd7f4d4b51d7987225eb2b13d05 Mon Sep 17 00:00:00 2001 From: Tao Ren Date: Sun, 15 Mar 2020 12:16:28 -0700 Subject: usb: gadget: add "usb_validate_langid" function The USB LANGID validation code in "check_user_usb_string" function is moved to "usb_validate_langid" function which can be used by other usb gadget drivers. Signed-off-by: Tao Ren Signed-off-by: Felipe Balbi --- drivers/usb/gadget/usbstring.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'drivers/usb/gadget/usbstring.c') diff --git a/drivers/usb/gadget/usbstring.c b/drivers/usb/gadget/usbstring.c index 7c24d1ce1088..58a4d3325090 100644 --- a/drivers/usb/gadget/usbstring.c +++ b/drivers/usb/gadget/usbstring.c @@ -65,3 +65,27 @@ usb_gadget_get_string (const struct usb_gadget_strings *table, int id, u8 *buf) return buf [0]; } EXPORT_SYMBOL_GPL(usb_gadget_get_string); + +/** + * usb_validate_langid - validate usb language identifiers + * @lang: usb language identifier + * + * Returns true for valid language identifier, otherwise false. + */ +bool usb_validate_langid(u16 langid) +{ + u16 primary_lang = langid & 0x3ff; /* bit [9:0] */ + u16 sub_lang = langid >> 10; /* bit [15:10] */ + + switch (primary_lang) { + case 0: + case 0x62 ... 0xfe: + case 0x100 ... 0x3ff: + return false; + } + if (!sub_lang) + return false; + + return true; +} +EXPORT_SYMBOL_GPL(usb_validate_langid); -- cgit v1.2.3