Re: [PATCH] cfg80211: Validate legacy rateset.

[Johannes Berg <johannes@sipsolutions.net>]

On 4/17/2012 1:07 AM, Bala Shanmugam wrote:
> On 04/16/2012 11:01 PM, Johannes Berg wrote:
>> On 4/12/2012 11:22 PM, Bala Shanmugam wrote:
>>> Legacy rates are not validated while configuring
>>> tx rateset using iw. So below cmd is accepted by nl80211.
>>> sudo iw wlan2 set bitrates legacy-2.4 3
>>>
>>> Validate legacy rates and return
>>> error while configuring improper rates.
>>>
>>> Signed-off-by: Bala Shanmugam<bkamatch@qca.qualcomm.com>
>>> ---
>>> net/wireless/nl80211.c | 2 ++
>>> 1 files changed, 2 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
>>> index e49da27..cc7bef7 100644
>>> --- a/net/wireless/nl80211.c
>>> +++ b/net/wireless/nl80211.c
>>> @@ -5540,6 +5540,8 @@ static int nl80211_set_tx_bitrate_mask(struct
>>> sk_buff *skb,
>>> sband,
>>> nla_data(tb[NL80211_TXRATE_LEGACY]),
>>> nla_len(tb[NL80211_TXRATE_LEGACY]));
>>> + if (mask.control[band].legacy == 0)
>>> + return -EINVAL;
>>
>> I don't think this is right since it would also reject an
>> intentionally empty set.

> This check comes into picture only when legacy rates are configured.
> For intentionally empty set "if (tb[NL80211_TXRATE_LEGACY])" condition
> will fail and control will not come here. I tested the same.
> With this patch
> "sudo iw wlan0 set bitrates mcs-5 6" executes without any error message.

However, that means "don't change legacy settings", not "empty legacy 
rateset".

johannes