mac80211: select and adjust bitrates according to channel mode

The various components accessing the bitrates table must use consider
the used channel bandwidth to select only available rates or calculate
the bitrate correctly.

There are some rates in reduced bandwidth modes which can't be
represented as multiples of 500kbps, like 2.25 MBit/s in 5 MHz mode. The
standard suggests to round up to the next multiple of 500kbps, just do
that in mac80211 as well.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
[make rate unsigned in ieee80211_add_tx_radiotap_header(), squash fix]
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>

1 files changed, 129 insertions, 30 deletions

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 61856e17a1e..1e45891ca21 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -141,14 +141,18 @@ int ieee80211_frame_duration(enum ieee80211_band band, size_t len,
 		dur = 16; /* SIFS + signal ext */
 		dur += 16; /* IEEE 802.11-2012 18.3.2.4: T_PREAMBLE = 16 usec */
 		dur += 4; /* IEEE 802.11-2012 18.3.2.4: T_SIGNAL = 4 usec */
-		dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10,
-					4 * rate); /* T_SYM x N_SYM */
 
 		/* IEEE 802.11-2012 18.3.2.4: all values above are:
 		 *  * times 4 for 5 MHz
 		 *  * times 2 for 10 MHz
 		 */
 		dur *= 1 << shift;
+
+		/* rates should already consider the channel bandwidth,
+		 * don't apply divisor again.
+		 */
+		dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10,
+					4 * rate); /* T_SYM x N_SYM */
 	} else {
 		/*
 		 * 802.11b or 802.11g with 802.11b compatibility:
@@ -205,7 +209,7 @@ __le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
 	struct ieee80211_rate *rate;
 	struct ieee80211_sub_if_data *sdata;
 	bool short_preamble;
-	int erp, shift = 0;
+	int erp, shift = 0, bitrate;
 	u16 dur;
 	struct ieee80211_supported_band *sband;
 
@@ -224,14 +228,16 @@ __le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
 		shift = ieee80211_vif_get_shift(vif);
 	}
 
+	bitrate = DIV_ROUND_UP(rate->bitrate, 1 << shift);
+
 	/* CTS duration */
-	dur = ieee80211_frame_duration(sband->band, 10, rate->bitrate,
+	dur = ieee80211_frame_duration(sband->band, 10, bitrate,
 				       erp, short_preamble, shift);
 	/* Data frame duration */
-	dur += ieee80211_frame_duration(sband->band, frame_len, rate->bitrate,
+	dur += ieee80211_frame_duration(sband->band, frame_len, bitrate,
 					erp, short_preamble, shift);
 	/* ACK duration */
-	dur += ieee80211_frame_duration(sband->band, 10, rate->bitrate,
+	dur += ieee80211_frame_duration(sband->band, 10, bitrate,
 					erp, short_preamble, shift);
 
 	return cpu_to_le16(dur);
@@ -247,7 +253,7 @@ __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
 	struct ieee80211_rate *rate;
 	struct ieee80211_sub_if_data *sdata;
 	bool short_preamble;
-	int erp, shift = 0;
+	int erp, shift = 0, bitrate;
 	u16 dur;
 	struct ieee80211_supported_band *sband;
 
@@ -265,12 +271,14 @@ __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
 		shift = ieee80211_vif_get_shift(vif);
 	}
 
+	bitrate = DIV_ROUND_UP(rate->bitrate, 1 << shift);
+
 	/* Data frame duration */
-	dur = ieee80211_frame_duration(sband->band, frame_len, rate->bitrate,
+	dur = ieee80211_frame_duration(sband->band, frame_len, bitrate,
 				       erp, short_preamble, shift);
 	if (!(frame_txctl->flags & IEEE80211_TX_CTL_NO_ACK)) {
 		/* ACK duration */
-		dur += ieee80211_frame_duration(sband->band, 10, rate->bitrate,
+		dur += ieee80211_frame_duration(sband->band, 10, bitrate,
 						erp, short_preamble, shift);
 	}
 
@@ -1175,7 +1183,7 @@ void ieee80211_send_deauth_disassoc(struct ieee80211_sub_if_data *sdata,
 int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer,
 			     size_t buffer_len, const u8 *ie, size_t ie_len,
 			     enum ieee80211_band band, u32 rate_mask,
-			     u8 channel)
+			     struct cfg80211_chan_def *chandef)
 {
 	struct ieee80211_supported_band *sband;
 	u8 *pos = buffer, *end = buffer + buffer_len;
@@ -1184,16 +1192,26 @@ int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer,
 	u8 rates[32];
 	int num_rates;
 	int ext_rates_len;
+	int shift;
+	u32 rate_flags;
 
 	sband = local->hw.wiphy->bands[band];
 	if (WARN_ON_ONCE(!sband))
 		return 0;
 
+	rate_flags = ieee80211_chandef_rate_flags(chandef);
+	shift = ieee80211_chandef_get_shift(chandef);
+
 	num_rates = 0;
 	for (i = 0; i < sband->n_bitrates; i++) {
 		if ((BIT(i) & rate_mask) == 0)
 			continue; /* skip rate */
-		rates[num_rates++] = (u8) (sband->bitrates[i].bitrate / 5);
+		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
+			continue;
+
+		rates[num_rates++] =
+			(u8) DIV_ROUND_UP(sband->bitrates[i].bitrate,
+					  (1 << shift) * 5);
 	}
 
 	supp_rates_len = min_t(int, num_rates, 8);
@@ -1233,12 +1251,13 @@ int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer,
 		pos += ext_rates_len;
 	}
 
-	if (channel && sband->band == IEEE80211_BAND_2GHZ) {
+	if (chandef->chan && sband->band == IEEE80211_BAND_2GHZ) {
 		if (end - pos < 3)
 			goto out_err;
 		*pos++ = WLAN_EID_DS_PARAMS;
 		*pos++ = 1;
-		*pos++ = channel;
+		*pos++ = ieee80211_frequency_to_channel(
+				chandef->chan->center_freq);
 	}
 
 	/* insert custom IEs that go before HT */
@@ -1303,9 +1322,9 @@ struct sk_buff *ieee80211_build_probe_req(struct ieee80211_sub_if_data *sdata,
 					  bool directed)
 {
 	struct ieee80211_local *local = sdata->local;
+	struct cfg80211_chan_def chandef;
 	struct sk_buff *skb;
 	struct ieee80211_mgmt *mgmt;
-	u8 chan_no;
 	int ies_len;
 
 	/*
@@ -1313,10 +1332,11 @@ struct sk_buff *ieee80211_build_probe_req(struct ieee80211_sub_if_data *sdata,
 	 * in order to maximize the chance that we get a response.  Some
 	 * badly-behaved APs don't respond when this parameter is included.
 	 */
+	chandef.width = sdata->vif.bss_conf.chandef.width;
 	if (directed)
-		chan_no = 0;
+		chandef.chan = NULL;
 	else
-		chan_no = ieee80211_frequency_to_channel(chan->center_freq);
+		chandef.chan = chan;
 
 	skb = ieee80211_probereq_get(&local->hw, &sdata->vif,
 				     ssid, ssid_len, 100 + ie_len);
@@ -1326,7 +1346,7 @@ struct sk_buff *ieee80211_build_probe_req(struct ieee80211_sub_if_data *sdata,
 	ies_len = ieee80211_build_preq_ies(local, skb_tail_pointer(skb),
 					   skb_tailroom(skb),
 					   ie, ie_len, chan->band,
-					   ratemask, chan_no);
+					   ratemask, &chandef);
 	skb_put(skb, ies_len);
 
 	if (dst) {
@@ -1360,16 +1380,19 @@ void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst,
 	}
 }
 
-u32 ieee80211_sta_get_rates(struct ieee80211_local *local,
+u32 ieee80211_sta_get_rates(struct ieee80211_sub_if_data *sdata,
 			    struct ieee802_11_elems *elems,
 			    enum ieee80211_band band, u32 *basic_rates)
 {
 	struct ieee80211_supported_band *sband;
 	struct ieee80211_rate *bitrates;
 	size_t num_rates;
-	u32 supp_rates;
-	int i, j;
-	sband = local->hw.wiphy->bands[band];
+	u32 supp_rates, rate_flags;
+	int i, j, shift;
+	sband = sdata->local->hw.wiphy->bands[band];
+
+	rate_flags = ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
+	shift = ieee80211_vif_get_shift(&sdata->vif);
 
 	if (WARN_ON(!sband))
 		return 1;
@@ -1394,7 +1417,15 @@ u32 ieee80211_sta_get_rates(struct ieee80211_local *local,
 			continue;
 
 		for (j = 0; j < num_rates; j++) {
-			if (bitrates[j].bitrate == own_rate) {
+			int brate;
+			if ((rate_flags & sband->bitrates[j].flags)
+			    != rate_flags)
+				continue;
+
+			brate = DIV_ROUND_UP(sband->bitrates[j].bitrate,
+					     1 << shift);
+
+			if (brate == own_rate) {
 				supp_rates |= BIT(j);
 				if (basic_rates && is_basic)
 					*basic_rates |= BIT(j);
@@ -2017,18 +2048,56 @@ void ieee80211_ht_oper_to_chandef(struct ieee80211_channel *control_chan,
 	cfg80211_chandef_create(chandef, control_chan, channel_type);
 }
 
+int ieee80211_parse_bitrates(struct cfg80211_chan_def *chandef,
+			     const struct ieee80211_supported_band *sband,
+			     const u8 *srates, int srates_len, u32 *rates)
+{
+	u32 rate_flags = ieee80211_chandef_rate_flags(chandef);
+	int shift = ieee80211_chandef_get_shift(chandef);
+	struct ieee80211_rate *br;
+	int brate, rate, i, j, count = 0;
+
+	*rates = 0;
+
+	for (i = 0; i < srates_len; i++) {
+		rate = srates[i] & 0x7f;
+
+		for (j = 0; j < sband->n_bitrates; j++) {
+			br = &sband->bitrates[j];
+			if ((rate_flags & br->flags) != rate_flags)
+				continue;
+
+			brate = DIV_ROUND_UP(br->bitrate, (1 << shift) * 5);
+			if (brate == rate) {
+				*rates |= BIT(j);
+				count++;
+				break;
+			}
+		}
+	}
+	return count;
+}
+
 int ieee80211_add_srates_ie(struct ieee80211_sub_if_data *sdata,
 			    struct sk_buff *skb, bool need_basic,
 			    enum ieee80211_band band)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_supported_band *sband;
-	int rate;
+	int rate, shift;
 	u8 i, rates, *pos;
 	u32 basic_rates = sdata->vif.bss_conf.basic_rates;
+	u32 rate_flags;
 
+	shift = ieee80211_vif_get_shift(&sdata->vif);
+	rate_flags = ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
 	sband = local->hw.wiphy->bands[band];
-	rates = sband->n_bitrates;
+	rates = 0;
+	for (i = 0; i < sband->n_bitrates; i++) {
+		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
+			continue;
+		rates++;
+	}
 	if (rates > 8)
 		rates = 8;
 
@@ -2040,10 +2109,15 @@ int ieee80211_add_srates_ie(struct ieee80211_sub_if_data *sdata,
 	*pos++ = rates;
 	for (i = 0; i < rates; i++) {
 		u8 basic = 0;
+		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
+			continue;
+
 		if (need_basic && basic_rates & BIT(i))
 			basic = 0x80;
 		rate = sband->bitrates[i].bitrate;
-		*pos++ = basic | (u8) (rate / 5);
+		rate = DIV_ROUND_UP(sband->bitrates[i].bitrate,
+				    5 * (1 << shift));
+		*pos++ = basic | (u8) rate;
 	}
 
 	return 0;
@@ -2055,12 +2129,22 @@ int ieee80211_add_ext_srates_ie(struct ieee80211_sub_if_data *sdata,
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_supported_band *sband;
-	int rate;
+	int rate, skip, shift;
 	u8 i, exrates, *pos;
 	u32 basic_rates = sdata->vif.bss_conf.basic_rates;
+	u32 rate_flags;
+
+	rate_flags = ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
+	shift = ieee80211_vif_get_shift(&sdata->vif);
 
 	sband = local->hw.wiphy->bands[band];
-	exrates = sband->n_bitrates;
+	exrates = 0;
+	for (i = 0; i < sband->n_bitrates; i++) {
+		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
+			continue;
+		exrates++;
+	}
+
 	if (exrates > 8)
 		exrates -= 8;
 	else
@@ -2073,12 +2157,19 @@ int ieee80211_add_ext_srates_ie(struct ieee80211_sub_if_data *sdata,
 		pos = skb_put(skb, exrates + 2);
 		*pos++ = WLAN_EID_EXT_SUPP_RATES;
 		*pos++ = exrates;
+		skip = 0;
 		for (i = 8; i < sband->n_bitrates; i++) {
 			u8 basic = 0;
+			if ((rate_flags & sband->bitrates[i].flags)
+			    != rate_flags)
+				continue;
+			if (skip++ < 8)
+				continue;
 			if (need_basic && basic_rates & BIT(i))
 				basic = 0x80;
-			rate = sband->bitrates[i].bitrate;
-			*pos++ = basic | (u8) (rate / 5);
+			rate = DIV_ROUND_UP(sband->bitrates[i].bitrate,
+					    5 * (1 << shift));
+			*pos++ = basic | (u8) rate;
 		}
 	}
 	return 0;
@@ -2162,9 +2253,17 @@ u64 ieee80211_calculate_rx_timestamp(struct ieee80211_local *local,
 			ri.flags |= RATE_INFO_FLAGS_SHORT_GI;
 	} else {
 		struct ieee80211_supported_band *sband;
+		int shift = 0;
+		int bitrate;
+
+		if (status->flag & RX_FLAG_10MHZ)
+			shift = 1;
+		if (status->flag & RX_FLAG_5MHZ)
+			shift = 2;
 
 		sband = local->hw.wiphy->bands[status->band];
-		ri.legacy = sband->bitrates[status->rate_idx].bitrate;
+		bitrate = sband->bitrates[status->rate_idx].bitrate;
+		ri.legacy = DIV_ROUND_UP(bitrate, (1 << shift));
 	}
 
 	rate = cfg80211_calculate_bitrate(&ri);