From f2d9d270c15ae0139b54a7e7466d738327e97e03 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 22 Nov 2012 14:11:39 +0100 Subject: [PATCH] mac80211: support VHT association 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 --- include/linux/ieee80211.h | 15 ++ net/mac80211/ieee80211_i.h | 2 + net/mac80211/mlme.c | 368 +++++++++++++++++++++++++++++-------- 3 files changed, 313 insertions(+), 72 deletions(-) diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h index f9c5a787d35..8f690e53dd8 100644 --- a/include/linux/ieee80211.h +++ b/include/linux/ieee80211.h @@ -1212,6 +1212,21 @@ struct ieee80211_vht_cap { struct ieee80211_vht_mcs_info supp_mcs; } __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 * diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 0a8f83d142f..8d8bf713638 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 d2a4f78b4b0..35d8cffc973 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 +3197,270 @@ 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 +3468,45 @@ 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; + ifmgd->flags |= ieee80211_determine_chantype(sdata, sband, + cbss->channel, + ht_oper, vht_oper, + &chandef); - 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; - } - } - - 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,