diff options
| author | Tao Ren <rentao.bupt@gmail.com> | 2020-03-15 12:16:28 -0700 |
|---|---|---|
| committer | Felipe Balbi <balbi@kernel.org> | 2020-05-05 10:58:51 +0300 |
| commit | 17309a6a43561bd7f4d4b51d7987225eb2b13d05 (patch) | |
| tree | ac43215c4142fe3e783955d1af712f340fddf4c0 /drivers/usb/gadget/usbstring.c | |
| parent | 5cc0710f23689455d40d590ebbcbcd21b0d84c77 (diff) | |
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 <rentao.bupt@gmail.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Diffstat (limited to 'drivers/usb/gadget/usbstring.c')
| -rw-r--r-- | drivers/usb/gadget/usbstring.c | 24 |
1 files changed, 24 insertions, 0 deletions
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); |