From: Christian Lamparter <chunkeey@xxxxxxxxxxxxxx>
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>---
Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx>
---
This is the version I've merged. The v2 version conflicted with
"mac80211: use min rate as basic rate for buggy APs" (commit
3432f9233704a66e6067944339a311744243707d).
Please take a close look to make sure I didn't mess it up!
include/linux/ieee80211.h | 3 +
net/mac80211/mlme.c | 90 ++++++++++++++++++++++++--------------------
2 files changed, 52 insertions(+), 41 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 d3b408c..b25567a 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1466,6 +1466,47 @@ 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 *min_rate, int *min_rate_index)
+{
+ 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);
+ if (rate < *min_rate) {
+ *min_rate = rate;
+ *min_rate_index = j;
+ }
+ break;
+ }
+ }
+ }
+}
static bool ieee80211_assoc_success(struct ieee80211_work *wk,
struct ieee80211_mgmt *mgmt, size_t len)
@@ -1482,7 +1523,7 @@ 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;
int min_rate = INT_MAX, min_rate_index = -1;
@@ -1540,47 +1581,14 @@ 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;
+ ieee80211_get_rates(sband, elems.supp_rates, elems.supp_rates_len,
+ &rates, &basic_rates, &have_higher_than_11mbit,
+ &min_rate, &min_rate_index);
- for (j = 0; j < sband->n_bitrates; j++) {
- if (sband->bitrates[j].bitrate == rate) {
- rates |= BIT(j);
- if (is_basic)
- basic_rates |= BIT(j);
- if (rate < min_rate) {
- min_rate = rate;
- min_rate_index = 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);
-
- 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);
- if (rate < min_rate) {
- min_rate = rate;
- min_rate_index = j;
- }
- break;
- }
- }
- }
+ ieee80211_get_rates(sband, elems.ext_supp_rates,
+ elems.ext_supp_rates_len, &rates, &basic_rates,
+ &have_higher_than_11mbit,
+ &min_rate, &min_rate_index);
/*
* some buggy APs don't advertise basic_rates. use the lowest
--
1.7.4.4
--
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