diff options
author | Bjørn Mork <bjorn@mork.no> | 2012-10-09 10:35:38 +0200 |
---|---|---|
committer | Bjørn Mork <bjorn@mork.no> | 2012-10-15 21:12:02 +0200 |
commit | 504c8fdf1fbd0ba2b8726ac098ed2f59022b2390 (patch) | |
tree | 054889d046fd60f43cbe2c6f85e22235dd6a62f0 | |
parent | ff48bcedaebc82bf52f5deb68997eef1b8a69cb8 (diff) |
net: cdc_ncm: do not bind to NCM compatible MBIM devices
The MBIM specification allows a MBIM device to disguise
itself as NCM for backwards compatibility, using additional
altsettings with different subclass (control) or protocol
(data):
C:* #Ifs= 2 Cfg#= 1 Atr=80 MxPwr=100mA
I: If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=0d Prot=00 Driver=cdc_mbim
E: Ad=81(I) Atr=03(Int.) MxPS= 64 Ivl=7ms
I:* If#= 0 Alt= 1 #EPs= 1 Cls=02(comm.) Sub=0e Prot=00 Driver=cdc_mbim
E: Ad=81(I) Atr=03(Int.) MxPS= 64 Ivl=7ms
I: If#= 1 Alt= 0 #EPs= 0 Cls=0a(data ) Sub=00 Prot=01 Driver=cdc_mbim
I: If#= 1 Alt= 1 #EPs= 2 Cls=0a(data ) Sub=00 Prot=01 Driver=cdc_mbim
E: Ad=81(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms
E: Ad=02(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms
I:* If#= 1 Alt= 2 #EPs= 2 Cls=0a(data ) Sub=00 Prot=02 Driver=cdc_mbim
E: Ad=81(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms
E: Ad=02(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms
If the MBIM driver is enabled then that should have priority
for devices providing such a NCM 1.0 backward compatibility
mode.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Suarez <gsuarez@smithmicro.com>
-rw-r--r-- | drivers/net/usb/cdc_ncm.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index 0c941ef23a1..a4d61a3e3d7 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -587,6 +587,33 @@ static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf) { int ret; + /* The MBIM spec defines a NCM compatible default altsetting, + * which we may have matched: + * + * "Functions that implement both NCM 1.0 and MBIM (an + * “NCM/MBIM function”) according to this recommendation + * shall provide two alternate settings for the + * Communication Interface. Alternate setting 0, and the + * associated class and endpoint descriptors, shall be + * constructed according to the rules given for the + * Communication Interface in section 5 of [USBNCM10]. + * Alternate setting 1, and the associated class and + * endpoint descriptors, shall be constructed according to + * the rules given in section 6 (USB Device Model) of this + * specification." + * + * Do not bind to such interfaces, allowing cdc_mbim to handle + * them + */ +#if IS_ENABLED(CONFIG_USB_NET_CDC_MBIM) + if ((intf->num_altsetting == 2) && + !usb_set_interface(dev->udev, + intf->cur_altsetting->desc.bInterfaceNumber, + CDC_NCM_COMM_ALTSETTING_MBIM) && + cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting)) + return -ENODEV; +#endif + /* NCM data altsetting is always 1 */ ret = cdc_ncm_bind_common(dev, intf, 1); |