diff options
| author | Bjørn Mork <bjorn@mork.no> | 2012-10-22 10:56:38 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-10-23 02:40:11 -0400 |
| commit | bd329e1284bc5fa6adaddd2ee9ca15328749a7a6 (patch) | |
| tree | a061e39f09ebf0526d1e69ae3888e6dfb7e6bd0d /drivers/net/usb/cdc_ncm.c | |
| parent | 9084ccf9f7f96302bdcbd5d7707e3ec8b8e1bf53 (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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/usb/cdc_ncm.c')
| -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 17b4ba03cb5..0ed03b1ba39 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -563,6 +563,33 @@ 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); |