Re: [PATCH v3 2/4] wifi: libertas: only add RSN/WPA IE in lbs_add_wpa_tlv

[Simon Horman <simon.horman@corigine.com>]

On Mon, Jan 16, 2023 at 12:21:24PM -0800, Doug Brown wrote:
> [You don't often get email from doug@schmorgal.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
> 
> The existing code only converts the first IE to a TLV, but it returns a
> value that takes the length of all IEs into account. When there is more
> than one IE (which happens with modern wpa_supplicant versions for
> example), the returned length is too long and extra junk TLVs get sent
> to the firmware, resulting in an association failure.
> 
> Fix this by finding the first RSN or WPA IE and only adding that. This
> has the extra benefit of working properly if the RSN/WPA IE isn't the
> first one in the IE buffer.
> 
> While we're at it, clean up the code to use the available structs like
> the other lbs_add_* functions instead of directly manipulating the TLV
> buffer.
> 
> Signed-off-by: Doug Brown <doug@schmorgal.com>
> ---
>  drivers/net/wireless/marvell/libertas/cfg.c | 28 +++++++++++++--------
>  1 file changed, 18 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/net/wireless/marvell/libertas/cfg.c b/drivers/net/wireless/marvell/libertas/cfg.c
> index 3e065cbb0af9..3f35dc7a1d7d 100644
> --- a/drivers/net/wireless/marvell/libertas/cfg.c
> +++ b/drivers/net/wireless/marvell/libertas/cfg.c

...

> @@ -428,14 +438,12 @@ static int lbs_add_wpa_tlv(u8 *tlv, const u8 *ie, u8 ie_len)
>          *   __le16  len
>          *   u8[]    data
>          */
> -       *tlv++ = *ie++;
> -       *tlv++ = 0;
> -       tlv_len = *tlv++ = *ie++;
> -       *tlv++ = 0;
> -       while (tlv_len--)
> -               *tlv++ = *ie++;
> -       /* the TLV is two bytes larger than the IE */
> -       return ie_len + 2;
> +       wpatlv->header.type = cpu_to_le16(wpaie->id);
> +       wpatlv->header.len = cpu_to_le16(wpaie->datalen);
> +       memcpy(wpatlv->data, wpaie->data, wpaie->datalen);

Hi Doug,

Thanks for fixing the endiness issues with cpu_to_le16()
This part looks good to me now. Likewise for patch 4/4.

One suggestion I have, which is probably taking things to far,
is a helper for what seems to be repeated code-pattern.
But I don't feel strongly about that.

> +
> +       /* Return the total number of bytes added to the TLV buffer */
> +       return sizeof(struct mrvl_ie_header) + wpaie->datalen;
>  }
> 
>  /*
> --
> 2.34.1
>