On 4/17/2012 11:03 PM, Bala Shanmugam wrote:
On 04/17/2012 07:29 PM, Johannes Berg wrote:
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@xxxxxxxxxxxxxxxx>
---
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
Good catch.
I didn't think of below configuration which is to specify empty legacy
rateset for 2.4 band.
sudo iw wlan0 set bitrates legacy-2.4
Correct me if I am wrong.
Anyway we need to reject invalid legacy rates and below additional check
will allow empty rateset
and block invalid rates
if (mask.control[band].legacy == 0 && nla_len(tb[NL80211_TXRATE_LEGACY]))
return -EINVAL;
But then you can still say
sudo iw wlan0 set bitrates legacy-2.4 1 2 3 4
and have it be accepted which is wrong as well.
You really should verify every single rate.
johannes
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