802.11n-2009 extends the supported rates element with a
magic value which can be used to prevent legacy stations
from joining the BSS.
However, this magic value is not a rate like the others
and the magic can simply be ignored/skipped at this late
stage.
Signed-off-by: Christian Lamparter <chunkeey@xxxxxxxxxxxxxx>---
---
v2:
Jouni's comment... Although I'm still not sure what is
the difference between the membership and basic
rate flag at this point.
---
include/linux/ieee80211.h | 3 ++
net/mac80211/mlme.c | 75 +++++++++++++++++++++++++--------------------
2 files changed, 45 insertions(+), 33 deletions(-)
diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 48363c3..9789aed 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -770,6 +770,9 @@ struct ieee80211_mgmt {
} u;
} __attribute__ ((packed));
+/* Supported Rates value encodings in 802.11n-2009 7.3.2.2 */
+#define BSS_MEMBERSHIP_SELECTOR_HT_PHY 127
+
/* mgmt header + 1 byte category code */
#define IEEE80211_MIN_ACTION_SIZE offsetof(struct ieee80211_mgmt, u.action.u)
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 0e5d8da..c0e54c5 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1463,6 +1463,42 @@ ieee80211_rx_mgmt_disassoc(struct ieee80211_sub_if_data *sdata,
return RX_MGMT_CFG80211_DISASSOC;
}
+static void ieee80211_get_rates(struct ieee80211_supported_band *sband,
+ u8 *supp_rates, unsigned int supp_rates_len,
+ u32 *rates, u32 *basic_rates,
+ bool *have_higher_than_11mbit)
+{
+ int i, j;
+
+ for (i = 0; i < supp_rates_len; i++) {
+ int rate = (supp_rates[i] & 0x7f) * 5;
+ bool is_basic = !!(supp_rates[i] & 0x80);
+
+ if (rate > 110)
+ *have_higher_than_11mbit = true;
+
+ /*
+ * BSS_MEMBERSHIP_SELECTOR_HT_PHY is defined in 802.11n-2009
+ * 7.3.2.2 as a magic value instead of a rate. Hence, skip it.
+ *
+ * Note: Even through the membership selector and the basic
+ * rate flag share the same bit, they are not exactly
+ * the same.
+ */
+ if (!!(supp_rates[i] & 0x80) &&
+ (supp_rates[i] & 0x7f) == BSS_MEMBERSHIP_SELECTOR_HT_PHY)
+ continue;
+
+ for (j = 0; j < sband->n_bitrates; j++) {
+ if (sband->bitrates[j].bitrate == rate) {
+ *rates |= BIT(j);
+ if (is_basic)
+ *basic_rates |= BIT(j);
+ break;
+ }
+ }
+ }
+}
static bool ieee80211_assoc_success(struct ieee80211_work *wk,
struct ieee80211_mgmt *mgmt, size_t len)
@@ -1479,7 +1515,7 @@ static bool ieee80211_assoc_success(struct ieee80211_work *wk,
struct ieee802_11_elems elems;
struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
u32 changed = 0;
- int i, j, err;
+ int err;
bool have_higher_than_11mbit = false;
u16 ap_ht_cap_flags;
@@ -1525,39 +1561,12 @@ static bool ieee80211_assoc_success(struct ieee80211_work *wk,
basic_rates = 0;
sband = local->hw.wiphy->bands[wk->chan->band];
- for (i = 0; i < elems.supp_rates_len; i++) {
- int rate = (elems.supp_rates[i] & 0x7f) * 5;
- bool is_basic = !!(elems.supp_rates[i] & 0x80);
-
- if (rate > 110)
- have_higher_than_11mbit = true;
-
- for (j = 0; j < sband->n_bitrates; j++) {
- if (sband->bitrates[j].bitrate == rate) {
- rates |= BIT(j);
- if (is_basic)
- basic_rates |= BIT(j);
- break;
- }
- }
- }
-
- for (i = 0; i < elems.ext_supp_rates_len; i++) {
- int rate = (elems.ext_supp_rates[i] & 0x7f) * 5;
- bool is_basic = !!(elems.ext_supp_rates[i] & 0x80);
+ ieee80211_get_rates(sband, elems.supp_rates, elems.supp_rates_len,
+ &rates, &basic_rates, &have_higher_than_11mbit);
- if (rate > 110)
- have_higher_than_11mbit = true;
-
- for (j = 0; j < sband->n_bitrates; j++) {
- if (sband->bitrates[j].bitrate == rate) {
- rates |= BIT(j);
- if (is_basic)
- basic_rates |= BIT(j);
- break;
- }
- }
- }
+ ieee80211_get_rates(sband, elems.ext_supp_rates,
+ elems.ext_supp_rates_len, &rates, &basic_rates,
+ &have_higher_than_11mbit);
sta->sta.supp_rates[wk->chan->band] = rates;
sdata->vif.bss_conf.basic_rates = basic_rates;
--
1.7.6.3
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