As TKIP is not updated to new security needs which arise when
TKIP is used to encrypt A-MPDU aggregated data frames, IEEE802.11n
does not allow any cipher other than CCMP (Which has new extensions
defined) as pairwise cipher between HT peers.
When such configuration (TKIP/WEP in HT) is forced, we still
associate in non-HT mode (11a/b/g).
Signed-off-by: Vasanthakumar Thiagarajan <[email protected]>
---
net/mac80211/ieee80211_i.h | 1 +
net/mac80211/iface.c | 3 ++-
net/mac80211/mlme.c | 9 ++++++++-
net/mac80211/wext.c | 12 +++++++++++-
4 files changed, 22 insertions(+), 3 deletions(-)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index a7dabae..dcc0d18 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -258,6 +258,7 @@ struct mesh_preq_queue {
#define IEEE80211_STA_AUTO_BSSID_SEL BIT(11)
#define IEEE80211_STA_AUTO_CHANNEL_SEL BIT(12)
#define IEEE80211_STA_PRIVACY_INVOKED BIT(13)
+#define IEEE80211_STA_TKIP_WEP_USED BIT(14)
/* flags for MLME request */
#define IEEE80211_STA_REQ_SCAN 0
#define IEEE80211_STA_REQ_DIRECT_PROBE 1
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 5abbc3f..19cfc0a 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -459,7 +459,8 @@ static int ieee80211_stop(struct net_device *dev)
synchronize_rcu();
skb_queue_purge(&sdata->u.sta.skb_queue);
- sdata->u.sta.flags &= ~IEEE80211_STA_PRIVACY_INVOKED;
+ sdata->u.sta.flags &= ~(IEEE80211_STA_PRIVACY_INVOKED |
+ IEEE80211_STA_TKIP_WEP_USED);
kfree(sdata->u.sta.extra_ie);
sdata->u.sta.extra_ie = NULL;
sdata->u.sta.extra_ie_len = 0;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 829cdf8..6f69eee 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -391,10 +391,17 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata,
}
/* wmm support is a must to HT */
+ /*
+ * IEEE802.11n does not allow TKIP/WEP as pairwise
+ * ciphers in HT mode. We still associate in non-ht
+ * mode (11a/b/g) if any one of these ciphers is
+ * configured as pairwise.
+ */
if (wmm && (ifsta->flags & IEEE80211_STA_WMM_ENABLED) &&
sband->ht_cap.ht_supported &&
(ht_ie = ieee80211_bss_get_ie(bss, WLAN_EID_HT_INFORMATION)) &&
- ht_ie[1] >= sizeof(struct ieee80211_ht_info)) {
+ ht_ie[1] >= sizeof(struct ieee80211_ht_info) &&
+ (!(ifsta->flags & IEEE80211_STA_TKIP_WEP_USED))) {
struct ieee80211_ht_info *ht_info =
(struct ieee80211_ht_info *)(ht_ie + 2);
u16 cap = sband->ht_cap.cap;
diff --git a/net/mac80211/wext.c b/net/mac80211/wext.c
index 1542804..ce089e7 100644
--- a/net/mac80211/wext.c
+++ b/net/mac80211/wext.c
@@ -873,12 +873,22 @@ static int ieee80211_ioctl_siwauth(struct net_device *dev,
switch (data->flags & IW_AUTH_INDEX) {
case IW_AUTH_WPA_VERSION:
- case IW_AUTH_CIPHER_PAIRWISE:
case IW_AUTH_CIPHER_GROUP:
case IW_AUTH_WPA_ENABLED:
case IW_AUTH_RX_UNENCRYPTED_EAPOL:
case IW_AUTH_KEY_MGMT:
break;
+ case IW_AUTH_CIPHER_PAIRWISE:
+ if (sdata->vif.type == NL80211_IFTYPE_STATION) {
+ if (data->value & (IW_AUTH_CIPHER_WEP40 |
+ IW_AUTH_CIPHER_WEP104 | IW_AUTH_CIPHER_TKIP))
+ sdata->u.sta.flags |=
+ IEEE80211_STA_TKIP_WEP_USED;
+ else
+ sdata->u.sta.flags &=
+ ~IEEE80211_STA_TKIP_WEP_USED;
+ }
+ break;
case IW_AUTH_DROP_UNENCRYPTED:
sdata->drop_unencrypted = !!data->value;
break;
--
1.5.5.1
On Mon, 2008-12-22 at 12:01 +0530, Vasanthakumar Thiagarajan wrote:
> As TKIP is not updated to new security needs which arise when
> TKIP is used to encrypt A-MPDU aggregated data frames, IEEE802.11n
> does not allow any cipher other than CCMP (Which has new extensions
> defined) as pairwise cipher between HT peers.
>
> When such configuration (TKIP/WEP in HT) is forced, we still
> associate in non-HT mode (11a/b/g).
> --- a/net/mac80211/wext.c
> +++ b/net/mac80211/wext.c
> @@ -873,12 +873,22 @@ static int ieee80211_ioctl_siwauth(struct net_device *dev,
>
> switch (data->flags & IW_AUTH_INDEX) {
> case IW_AUTH_WPA_VERSION:
> - case IW_AUTH_CIPHER_PAIRWISE:
> case IW_AUTH_CIPHER_GROUP:
> case IW_AUTH_WPA_ENABLED:
> case IW_AUTH_RX_UNENCRYPTED_EAPOL:
> case IW_AUTH_KEY_MGMT:
> break;
> + case IW_AUTH_CIPHER_PAIRWISE:
> + if (sdata->vif.type == NL80211_IFTYPE_STATION) {
> + if (data->value & (IW_AUTH_CIPHER_WEP40 |
> + IW_AUTH_CIPHER_WEP104 | IW_AUTH_CIPHER_TKIP))
> + sdata->u.sta.flags |=
> + IEEE80211_STA_TKIP_WEP_USED;
> + else
> + sdata->u.sta.flags &=
> + ~IEEE80211_STA_TKIP_WEP_USED;
> + }
> + break;
I still think you might need to put something into cfg.c. Can't we check
the key algorithm for the pairwise key associated with the AP's sta_info
directly in _send_assoc?
johannes
On Mon, 2008-12-22 at 13:40 +0530, Vasanthakumar Thiagarajan wrote:
> On Mon, Dec 22, 2008 at 12:19:45PM +0530, Johannes Berg wrote:
> > > + case IW_AUTH_CIPHER_PAIRWISE:
> > > + if (sdata->vif.type == NL80211_IFTYPE_STATION) {
> > > + if (data->value & (IW_AUTH_CIPHER_WEP40 |
> > > + IW_AUTH_CIPHER_WEP104 | IW_AUTH_CIPHER_TKIP))
> > > + sdata->u.sta.flags |=
> > > + IEEE80211_STA_TKIP_WEP_USED;
> > > + else
> > > + sdata->u.sta.flags &=
> > > + ~IEEE80211_STA_TKIP_WEP_USED;
> > > + }
> > > + break;
> >
> > Can't we check
> > the key algorithm for the pairwise key associated with the AP's sta_info
> > directly in _send_assoc?
>
> AP's sta_info will not have the negotiated pirwise cipher before association.
Ok. I guess this patch is the way to go then, and we'll figure out how
to make it work with nl80211/cfg80211 when we actually push all the key
operations there.
johannes
On Mon, Dec 22, 2008 at 12:19:45PM +0530, Johannes Berg wrote:
> > + case IW_AUTH_CIPHER_PAIRWISE:
> > + if (sdata->vif.type == NL80211_IFTYPE_STATION) {
> > + if (data->value & (IW_AUTH_CIPHER_WEP40 |
> > + IW_AUTH_CIPHER_WEP104 | IW_AUTH_CIPHER_TKIP))
> > + sdata->u.sta.flags |=
> > + IEEE80211_STA_TKIP_WEP_USED;
> > + else
> > + sdata->u.sta.flags &=
> > + ~IEEE80211_STA_TKIP_WEP_USED;
> > + }
> > + break;
>
> I still think you might need to put something into cfg.c.
I could not find a hook in cfg.c which is meant for configuring negotiated
pairwise cipher into driver. You mean add_key() ?, which configures
the key after the association.
> Can't we check the key algorithm for the pairwise key associated
> with the AP's sta_info directly in _send_assoc?
In that case, I might need to introduce one more entry in
enum ieee80211_key_alg called ALG_NONE. When we have a new
entry in enum, we might end up handling that in all the case
statements wherever this enum is used (quite a few places in
mac80211 and almost all the drivers) to
mute compilation warnings.
Vasanth
On Mon, Dec 22, 2008 at 12:19:45PM +0530, Johannes Berg wrote:
> > + case IW_AUTH_CIPHER_PAIRWISE:
> > + if (sdata->vif.type == NL80211_IFTYPE_STATION) {
> > + if (data->value & (IW_AUTH_CIPHER_WEP40 |
> > + IW_AUTH_CIPHER_WEP104 | IW_AUTH_CIPHER_TKIP))
> > + sdata->u.sta.flags |=
> > + IEEE80211_STA_TKIP_WEP_USED;
> > + else
> > + sdata->u.sta.flags &=
> > + ~IEEE80211_STA_TKIP_WEP_USED;
> > + }
> > + break;
>
> Can't we check
> the key algorithm for the pairwise key associated with the AP's sta_info
> directly in _send_assoc?
AP's sta_info will not have the negotiated pirwise cipher before association.
Vasanth