From: Johannes Berg <johannes.berg@xxxxxxxxx>
Determine the VHT channel from the AP's VHT operation IE
(if present) and configure the hardware to that channel
if it is supported. If channel contexts cause a channel
to not be usable, try a smaller bandwidth.
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
include/linux/ieee80211.h | 15 ++
net/mac80211/ieee80211_i.h | 2 +
net/mac80211/mlme.c | 370 ++++++++++++++++++++++++++++++++++++---------
3 files changed, 315 insertions(+), 72 deletions(-)
diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index f9c5a78..8f690e5 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -1213,6 +1213,21 @@ struct ieee80211_vht_cap {
} __packed;
/**
+ * enum ieee80211_vht_chanwidth - VHT channel width
+ * @IEEE80211_VHT_CHANWIDTH_USE_HT: use the HT operation IE to
+ * determine the channel width (20 or 40 MHz)
+ * @IEEE80211_VHT_CHANWIDTH_80MHZ: 80 MHz bandwidth
+ * @IEEE80211_VHT_CHANWIDTH_160MHZ: 160 MHz bandwidth
+ * @IEEE80211_VHT_CHANWIDTH_80P80MHZ: 80+80 MHz bandwidth
+ */
+enum ieee80211_vht_chanwidth {
+ IEEE80211_VHT_CHANWIDTH_USE_HT = 0,
+ IEEE80211_VHT_CHANWIDTH_80MHZ = 1,
+ IEEE80211_VHT_CHANWIDTH_160MHZ = 2,
+ IEEE80211_VHT_CHANWIDTH_80P80MHZ = 3,
+};
+
+/**
* struct ieee80211_vht_operation - VHT operation IE
*
* This structure is the "VHT operation element" as
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 0a8f83d..8d8bf71 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -371,6 +371,8 @@ enum ieee80211_sta_flags {
IEEE80211_STA_RESET_SIGNAL_AVE = BIT(9),
IEEE80211_STA_DISABLE_40MHZ = BIT(10),
IEEE80211_STA_DISABLE_VHT = BIT(11),
+ IEEE80211_STA_DISABLE_80P80MHZ = BIT(12),
+ IEEE80211_STA_DISABLE_160MHZ = BIT(13),
};
struct ieee80211_mgd_auth_data {
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index d2a4f78..e15977f 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -354,6 +354,16 @@ static void ieee80211_add_vht_ie(struct ieee80211_sub_if_data *sdata,
/* determine capability flags */
cap = vht_cap.cap;
+ if (sdata->u.mgd.flags & IEEE80211_STA_DISABLE_80P80MHZ) {
+ cap &= ~IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ;
+ cap |= IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ;
+ }
+
+ if (sdata->u.mgd.flags & IEEE80211_STA_DISABLE_160MHZ) {
+ cap &= ~IEEE80211_VHT_CAP_SHORT_GI_160;
+ cap &= ~IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ;
+ }
+
/* reserve and fill IE */
pos = skb_put(skb, sizeof(struct ieee80211_vht_cap) + 2);
ieee80211_ie_build_vht_cap(pos, &vht_cap, cap);
@@ -543,6 +553,10 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
offset = noffset;
}
+ if (WARN_ON_ONCE((ifmgd->flags & IEEE80211_STA_DISABLE_HT) &&
+ !(ifmgd->flags & IEEE80211_STA_DISABLE_VHT)))
+ ifmgd->flags |= IEEE80211_STA_DISABLE_VHT;
+
if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT))
ieee80211_add_ht_ie(sdata, skb, assoc_data->ap_ht_param,
sband, chan, sdata->smps_mode);
@@ -3183,23 +3197,272 @@ int ieee80211_max_network_latency(struct notifier_block *nb,
return 0;
}
+static u32 chandef_downgrade(struct cfg80211_chan_def *c)
+{
+ u32 ret;
+ int tmp;
+
+ switch (c->width) {
+ case NL80211_CHAN_WIDTH_20:
+ c->width = NL80211_CHAN_WIDTH_20_NOHT;
+ ret = IEEE80211_STA_DISABLE_HT | IEEE80211_STA_DISABLE_VHT;
+ break;
+ case NL80211_CHAN_WIDTH_40:
+ c->width = NL80211_CHAN_WIDTH_20;
+ c->center_freq1 = c->chan->center_freq;
+ ret = IEEE80211_STA_DISABLE_40MHZ |
+ IEEE80211_STA_DISABLE_VHT;
+ break;
+ case NL80211_CHAN_WIDTH_80:
+ tmp = (30 + c->chan->center_freq - c->center_freq1)/20;
+ /* n_P40 */
+ tmp /= 2;
+ /* freq_P40 */
+ c->center_freq1 = c->center_freq1 - 20 + 40 * tmp;
+ c->width = NL80211_CHAN_WIDTH_40;
+ ret = IEEE80211_STA_DISABLE_VHT;
+ break;
+ case NL80211_CHAN_WIDTH_80P80:
+ c->center_freq2 = 0;
+ c->width = NL80211_CHAN_WIDTH_80;
+ ret = IEEE80211_STA_DISABLE_80P80MHZ |
+ IEEE80211_STA_DISABLE_160MHZ;
+ break;
+ case NL80211_CHAN_WIDTH_160:
+ /* n_P20 */
+ tmp = (70 + c->chan->center_freq - c->center_freq1)/20;
+ /* n_P80 */
+ tmp /= 4;
+ c->center_freq1 = c->center_freq1 - 40 + 80 * tmp;
+ c->width = NL80211_CHAN_WIDTH_80;
+ ret = IEEE80211_STA_DISABLE_80P80MHZ |
+ IEEE80211_STA_DISABLE_160MHZ;
+ break;
+ default:
+ case NL80211_CHAN_WIDTH_20_NOHT:
+ WARN_ON_ONCE(1);
+ c->width = NL80211_CHAN_WIDTH_20_NOHT;
+ ret = IEEE80211_STA_DISABLE_HT | IEEE80211_STA_DISABLE_VHT;
+ break;
+ }
+
+ WARN_ON_ONCE(!cfg80211_chandef_valid(c));
+
+ return ret;
+}
+
+static u32
+ieee80211_determine_chantype(struct ieee80211_sub_if_data *sdata,
+ struct ieee80211_supported_band *sband,
+ struct ieee80211_channel *channel,
+ const struct ieee80211_ht_operation *ht_oper,
+ const struct ieee80211_vht_operation *vht_oper,
+ struct cfg80211_chan_def *chandef)
+{
+ struct cfg80211_chan_def vht_chandef;
+ u32 ht_cfreq, ret;
+
+ chandef->chan = channel;
+ chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
+ chandef->center_freq1 = channel->center_freq;
+ chandef->center_freq2 = 0;
+
+ if (!ht_oper || !sband->ht_cap.ht_supported) {
+ ret = IEEE80211_STA_DISABLE_HT | IEEE80211_STA_DISABLE_VHT;
+ goto out;
+ }
+
+ chandef->width = NL80211_CHAN_WIDTH_20;
+
+ ht_cfreq = ieee80211_channel_to_frequency(ht_oper->primary_chan,
+ channel->band);
+ /* check that channel matches the right operating channel */
+ if (channel->center_freq != ht_cfreq) {
+ /*
+ * It's possible that some APs are confused here;
+ * Netgear WNDR3700 sometimes reports 4 higher than
+ * the actual channel in association responses, but
+ * since we look at probe response/beacon data here
+ * it should be OK.
+ */
+ sdata_info(sdata,
+ "Wrong control channel: center-freq: %d ht-cfreq: %d ht->primary_chan: %d band: %d - Disabling HT\n",
+ channel->center_freq, ht_cfreq,
+ ht_oper->primary_chan, channel->band);
+ ret = IEEE80211_STA_DISABLE_HT | IEEE80211_STA_DISABLE_VHT;
+ goto out;
+ }
+
+ /* check 40 MHz support, if we have it */
+ if (sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) {
+ switch (ht_oper->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
+ case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
+ chandef->width = NL80211_CHAN_WIDTH_40;
+ chandef->center_freq1 += 10;
+ break;
+ case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
+ chandef->width = NL80211_CHAN_WIDTH_40;
+ chandef->center_freq1 -= 10;
+ break;
+ }
+ } else {
+ /* 40 MHz (and 80 MHz) must be supported for VHT */
+ ret = IEEE80211_STA_DISABLE_VHT;
+ goto out;
+ }
+
+ if (!vht_oper || !sband->vht_cap.vht_supported) {
+ ret = IEEE80211_STA_DISABLE_VHT;
+ goto out;
+ }
+
+ vht_chandef.chan = channel;
+ vht_chandef.center_freq1 =
+ ieee80211_channel_to_frequency(vht_oper->center_freq_seg1_idx,
+ channel->band);
+ vht_chandef.center_freq2 = 0;
+
+ if (vht_oper->center_freq_seg2_idx)
+ vht_chandef.center_freq2 =
+ ieee80211_channel_to_frequency(
+ vht_oper->center_freq_seg2_idx,
+ channel->band);
+
+ switch (vht_oper->chan_width) {
+ case IEEE80211_VHT_CHANWIDTH_USE_HT:
+ vht_chandef.width = chandef->width;
+ break;
+ case IEEE80211_VHT_CHANWIDTH_80MHZ:
+ vht_chandef.width = NL80211_CHAN_WIDTH_80;
+ break;
+ case IEEE80211_VHT_CHANWIDTH_160MHZ:
+ vht_chandef.width = NL80211_CHAN_WIDTH_160;
+ break;
+ case IEEE80211_VHT_CHANWIDTH_80P80MHZ:
+ vht_chandef.width = NL80211_CHAN_WIDTH_80P80;
+ break;
+ default:
+ sdata_info(sdata,
+ "AP VHT operation IE has invalid channel width (%d), disable VHT\n",
+ vht_oper->chan_width);
+ ret = IEEE80211_STA_DISABLE_VHT;
+ goto out;
+ }
+
+ if (!cfg80211_chandef_valid(&vht_chandef)) {
+ sdata_info(sdata,
+ "AP VHT information is invalid, disable VHT\n");
+ ret = IEEE80211_STA_DISABLE_VHT;
+ goto out;
+ }
+
+ if (cfg80211_chandef_identical(chandef, &vht_chandef)) {
+ ret = 0;
+ goto out;
+ }
+
+ if (!cfg80211_chandef_compatible(chandef, &vht_chandef)) {
+ sdata_info(sdata,
+ "AP VHT information doesn't match HT, disable VHT\n");
+ ret = IEEE80211_STA_DISABLE_VHT;
+ goto out;
+ }
+
+ *chandef = vht_chandef;
+
+ ret = 0;
+
+ while (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
+ IEEE80211_CHAN_DISABLED)) {
+ if (WARN_ON(chandef->width == NL80211_CHAN_WIDTH_20_NOHT)) {
+ ret = IEEE80211_STA_DISABLE_HT |
+ IEEE80211_STA_DISABLE_VHT;
+ goto out;
+ }
+
+ ret = chandef_downgrade(chandef);
+ }
+
+ if (chandef->width != vht_chandef.width)
+ sdata_info(sdata,
+ "local regulatory prevented using AP HT/VHT configuration, downgraded\n");
+
+out:
+ WARN_ON_ONCE(!cfg80211_chandef_valid(chandef));
+ return ret;
+}
+
+static u8 ieee80211_ht_vht_rx_chains(struct ieee80211_sub_if_data *sdata,
+ struct cfg80211_bss *cbss)
+{
+ struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
+ const u8 *ht_cap_ie, *vht_cap_ie;
+ const struct ieee80211_ht_cap *ht_cap;
+ const struct ieee80211_vht_cap *vht_cap;
+ u8 chains = 1;
+
+ if (ifmgd->flags & IEEE80211_STA_DISABLE_HT)
+ return chains;
+
+ ht_cap_ie = cfg80211_find_ie(WLAN_EID_HT_CAPABILITY,
+ cbss->information_elements,
+ cbss->len_information_elements);
+ if (ht_cap_ie && ht_cap_ie[1] >= sizeof(*ht_cap)) {
+ ht_cap = (void *)(ht_cap_ie + 2);
+ chains = ieee80211_mcs_to_chains(&ht_cap->mcs);
+ /*
+ * TODO: use "Tx Maximum Number Spatial Streams Supported" and
+ * "Tx Unequal Modulation Supported" fields.
+ */
+
+ }
+
+ if (ifmgd->flags & IEEE80211_STA_DISABLE_VHT)
+ return chains;
+
+
+ vht_cap_ie = cfg80211_find_ie(WLAN_EID_VHT_CAPABILITY,
+ cbss->information_elements,
+ cbss->len_information_elements);
+ if (vht_cap_ie && vht_cap_ie[1] >= sizeof(*vht_cap)) {
+ u8 nss;
+ u16 tx_mcs_map;
+
+ vht_cap = (void *)(vht_cap_ie + 2);
+ tx_mcs_map = le16_to_cpu(vht_cap->supp_mcs.tx_mcs_map);
+ for (nss = 8; nss > 0; nss--) {
+ if (((tx_mcs_map >> (2 * (nss - 1))) & 3) !=
+ IEEE80211_VHT_MCS_NOT_SUPPORTED)
+ break;
+ }
+ /* TODO: use "Tx Highest Supported Long GI Data Rate" field? */
+ chains = max(chains, nss);
+ }
+
+ return chains;
+}
+
static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
struct cfg80211_bss *cbss)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
- int ht_cfreq;
- enum nl80211_channel_type channel_type = NL80211_CHAN_NO_HT;
- const u8 *ht_oper_ie;
const struct ieee80211_ht_operation *ht_oper = NULL;
+ const struct ieee80211_vht_operation *vht_oper = NULL;
struct ieee80211_supported_band *sband;
struct cfg80211_chan_def chandef;
+ int ret;
sband = local->hw.wiphy->bands[cbss->channel->band];
- ifmgd->flags &= ~IEEE80211_STA_DISABLE_40MHZ;
+ ifmgd->flags &= ~(IEEE80211_STA_DISABLE_40MHZ |
+ IEEE80211_STA_DISABLE_80P80MHZ |
+ IEEE80211_STA_DISABLE_160MHZ);
+
+ if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT) &&
+ sband->ht_cap.ht_supported) {
+ const u8 *ht_oper_ie;
- if (sband->ht_cap.ht_supported) {
ht_oper_ie = cfg80211_find_ie(WLAN_EID_HT_OPERATION,
cbss->information_elements,
cbss->len_information_elements);
@@ -3207,82 +3470,45 @@ static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
ht_oper = (void *)(ht_oper_ie + 2);
}
- if (ht_oper) {
- ht_cfreq = ieee80211_channel_to_frequency(ht_oper->primary_chan,
- cbss->channel->band);
- /* check that channel matches the right operating channel */
- if (cbss->channel->center_freq != ht_cfreq) {
- /*
- * It's possible that some APs are confused here;
- * Netgear WNDR3700 sometimes reports 4 higher than
- * the actual channel in association responses, but
- * since we look at probe response/beacon data here
- * it should be OK.
- */
+ if (!(ifmgd->flags & IEEE80211_STA_DISABLE_VHT) &&
+ sband->vht_cap.vht_supported) {
+ const u8 *vht_oper_ie;
+
+ vht_oper_ie = cfg80211_find_ie(WLAN_EID_VHT_OPERATION,
+ cbss->information_elements,
+ cbss->len_information_elements);
+ if (vht_oper_ie && vht_oper_ie[1] >= sizeof(*vht_oper))
+ vht_oper = (void *)(vht_oper_ie + 2);
+ if (vht_oper && !ht_oper) {
+ vht_oper = NULL;
sdata_info(sdata,
- "Wrong control channel: center-freq: %d ht-cfreq: %d ht->primary_chan: %d band: %d - Disabling HT\n",
- cbss->channel->center_freq,
- ht_cfreq, ht_oper->primary_chan,
- cbss->channel->band);
- ht_oper = NULL;
+ "AP advertised VHT without HT, disabling both\n");
+ sdata->flags |= IEEE80211_STA_DISABLE_HT;
+ sdata->flags |= IEEE80211_STA_DISABLE_VHT;
}
}
- if (ht_oper) {
- /*
- * cfg80211 already verified that the channel itself can
- * be used, but it didn't check that we can do the right
- * HT type, so do that here as well. If HT40 isn't allowed
- * on this channel, disable 40 MHz operation.
- */
- const u8 *ht_cap_ie;
- const struct ieee80211_ht_cap *ht_cap;
- u8 chains = 1;
-
- channel_type = NL80211_CHAN_HT20;
-
- if (sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) {
- switch (ht_oper->ht_param &
- IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
- case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
- if (cbss->channel->flags &
- IEEE80211_CHAN_NO_HT40PLUS)
- ifmgd->flags |=
- IEEE80211_STA_DISABLE_40MHZ;
- else
- channel_type = NL80211_CHAN_HT40PLUS;
- break;
- case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
- if (cbss->channel->flags &
- IEEE80211_CHAN_NO_HT40MINUS)
- ifmgd->flags |=
- IEEE80211_STA_DISABLE_40MHZ;
- else
- channel_type = NL80211_CHAN_HT40MINUS;
- break;
- }
- }
+ ifmgd->flags |= ieee80211_determine_chantype(sdata, sband,
+ cbss->channel,
+ ht_oper, vht_oper,
+ &chandef);
- ht_cap_ie = cfg80211_find_ie(WLAN_EID_HT_CAPABILITY,
- cbss->information_elements,
- cbss->len_information_elements);
- if (ht_cap_ie && ht_cap_ie[1] >= sizeof(*ht_cap)) {
- ht_cap = (void *)(ht_cap_ie + 2);
- chains = ieee80211_mcs_to_chains(&ht_cap->mcs);
- }
- sdata->needed_rx_chains = min(chains, local->rx_chains);
- } else {
- sdata->needed_rx_chains = 1;
- sdata->u.mgd.flags |= IEEE80211_STA_DISABLE_HT;
- }
+ sdata->needed_rx_chains = min(ieee80211_ht_vht_rx_chains(sdata, cbss),
+ local->rx_chains);
/* will change later if needed */
sdata->smps_mode = IEEE80211_SMPS_OFF;
- ieee80211_vif_release_channel(sdata);
- cfg80211_chandef_create(&chandef, cbss->channel, channel_type);
- return ieee80211_vif_use_channel(sdata, &chandef,
- IEEE80211_CHANCTX_SHARED);
+ /*
+ * If this fails (possibly due to channel context sharing
+ * on incompatible channels, e.g. 80+80 and 160 sharing the
+ * same control channel) try to use a smaller bandwidth.
+ */
+ ret = ieee80211_vif_use_channel(sdata, &chandef,
+ IEEE80211_CHANCTX_SHARED);
+ while (ret && chandef.width != NL80211_CHAN_WIDTH_20_NOHT)
+ ifmgd->flags |= chandef_downgrade(&chandef);
+ return ret;
}
static int ieee80211_prep_connection(struct ieee80211_sub_if_data *sdata,
--
1.8.0
--
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