[Spice-devel] [usbredir PATCH] usbredirfilter_check: block device if all its interfaces skipped

[Hans de Goede]

Hi,

On 08-07-15 15:26, Uri Lublin wrote:
> See usbredirfilter.h for when interfaces are skipped.
>
> Fixes rhbz#1179210

Sigh, the kvm in question is really messed up as it uses non bootclass hid interfaces,
that means it won't work in many BIOS' etc. What a mess ...

> ---
>   usbredirparser/usbredirfilter.c | 11 ++++++++---
>   1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/usbredirparser/usbredirfilter.c b/usbredirparser/usbredirfilter.c
> index ef9c63a..5cbbfbf 100644
> --- a/usbredirparser/usbredirfilter.c
> +++ b/usbredirparser/usbredirfilter.c
> @@ -172,7 +172,7 @@ int usbredirfilter_check(
>       uint16_t vendor_id, uint16_t product_id, uint16_t device_version_bcd,
>       int flags)
>   {
> -    int i, rc;
> +    int i, rc, num_skipped=0;
>
>       if (usbredirfilter_verify(rules, rules_count))
>           return -EINVAL;
> @@ -190,9 +190,10 @@ int usbredirfilter_check(
>       for (i = 0; i < interface_count; i++) {
>           if (!(flags & usbredirfilter_fl_dont_skip_non_boot_hid) &&
>                   interface_count > 1 && interface_class[i] == 0x03 &&
> -                interface_subclass[i] == 0x00 && interface_protocol[i] == 0x00)
> +                interface_subclass[i] == 0x00 && interface_protocol[i] == 0x00) {
> +            num_skipped++;
>               continue;
> -
> +	}
>           rc = usbredirfilter_check1(rules, rules_count, interface_class[i],
>                                      vendor_id, product_id, device_version_bcd,
>                                      flags & usbredirfilter_fl_default_allow);
> @@ -200,6 +201,10 @@ int usbredirfilter_check(
>               return rc;
>       }
>
> +    /* If all interfaces were skipped, block the device */
> +    if (num_skipped == interface_count)
> +	return -ENOENT;
> +
>       return 0;
>   }

This seems wrong, this means that if a user wants to redirect some custom hid device,
with just a single hid interface that it will always be blocked because of this.

I suggest instead adding a vid/pid based list of devices on which to not skip non
boot compliant hid devices. This way if hid devices are allowed to be redirected
by the filter, the device can still be redirected, and in the default case where
hid devices are not allowed, we will skip the non-boot-hid skipping, do the regular
hid check, and block the device based on that.

Regards,

Hans