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iwd/src/band.c

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/*
*
* Wireless daemon for Linux
*
* Copyright (C) 2021 Intel Corporation. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <stdbool.h>
#include <stdint.h>
#include <errno.h>
#include <ell/ell.h>
#include "ell/useful.h"
#include "src/band.h"
#include "src/netdev.h"
void band_free(struct band *band)
{
if (band->he_capabilities)
l_queue_destroy(band->he_capabilities, l_free);
l_free(band->freq_attrs);
l_free(band);
}
/*
* Rates are stored as they are encoded in the Supported Rates IE.
* This data was taken from 802.11 Section 17.3.10.2 Table 17-18 and
* Table 17-4. Together we have minimum RSSI required for a given data rate.
*/
static const struct {
int32_t rssi;
uint8_t rate;
} rate_rssi_map[] = {
{ -90, 2 }, /* Make something up for 11b rates */
{ -88, 4 },
{ -86, 11 },
{ -84, 22 },
{ -82, 12 },
{ -81, 18 },
{ -79, 24 },
{ -77, 36 },
{ -74, 48 },
{ -70, 72 },
{ -66, 96 },
{ -65, 108 },
};
static bool peer_supports_rate(const uint8_t *rates, uint8_t rate)
{
int i;
if (rates && rates[1]) {
for (i = 0; i < rates[1]; i++) {
uint8_t r = rates[i + 2] & 0x7f;
if (r == rate)
return true;
}
}
return false;
}
int band_estimate_nonht_rate(const struct band *band,
const uint8_t *supported_rates,
const uint8_t *ext_supported_rates,
int32_t rssi, uint64_t *out_data_rate)
{
int nrates = L_ARRAY_SIZE(rate_rssi_map);
uint8_t max_rate = 0;
int i;
if (!supported_rates && !ext_supported_rates)
return -EINVAL;
/*
* Start at the back of the array. Rates are generally given in
* ascending order, starting at 11b rates, then 11g rates. More often
* than not we'll pick the highest rate and avoid unneeded processing
*/
for (i = band->supported_rates_len - 1; i >= 0; i--) {
uint8_t rate = band->supported_rates[i];
int j;
if (max_rate >= rate)
continue;
/* Can this rate be used at the peer's RSSI? */
for (j = 0; j < nrates; j++)
if (rate_rssi_map[j].rate == rate)
break;
if (j == nrates)
continue;
if (rssi < rate_rssi_map[j].rssi)
continue;
if (peer_supports_rate(supported_rates, rate) ||
peer_supports_rate(ext_supported_rates, rate))
max_rate = rate;
}
if (!max_rate)
return -ENETUNREACH;
*out_data_rate = max_rate * 500000;
return 0;
}
/*
* Base RSSI values for 20MHz (HT, VHT and HE) channel. These values can be
* used to calculate the minimum RSSI values for all other channel widths. HT
* MCS indexes are grouped into ranges of 8 (per spatial stream), VHT in groups
* of 10 and HE in groups of 12. This just means HT will not use the last four
* index's of this array, and VHT won't use the last two.
*
* Note: The values here are not based on anything from 802.11 but data
* found elsewhere online (presumably from testing, we hope). The two
* indexes for HE (MCS 11/12) are not based on any data, but just
* increased by 3dB compared to the previous value. We consider this good
* enough for its purpose to estimate the date rate for network/BSS
* preference.
*/
static const int32_t ht_vht_he_base_rssi[] = {
-82, -79, -77, -74, -70, -66, -65, -64, -59, -57, -54, -51
};
/*
* Data Rate for HT/VHT is obtained according to this formula:
* Nsd * Nbpscs * R * Nss / (Tdft + Tgi)
*
* Where Nsd is [52, 108, 234, 468] for 20/40/80/160 Mhz respectively
* Nbpscs is [1, 2, 4, 6, 8] for BPSK/QPSK/16QAM/64QAM/256QAM
* R is [1/2, 2/3, 3/4, 5/6] depending on the MCS index
* Nss is the number of spatial streams
* Tdft = 3.2 us
* Tgi = Long/Short GI of 0.8/0.4 us
*
* Short GI rate can be easily obtained by multiplying by (10 / 9)
*
* The table was pre-computed using the following python snippet:
* rfactors = [ 1/2, 1/2, 3/4, 1/2, 3/4, 2/3, 3/4, 5/6, 3/4, 5/6 ]
* nbpscs = [1, 2, 2, 4, 4, 6, 6, 6, 8, 8 ]
* nsds = [52, 108, 234, 468]
*
* for nsd in nsds:
* rates = []
* for i in xrange(0, 10):
* data_rate = (nsd * rfactors[i] * nbpscs[i]) / 0.004
* rates.append(int(data_rate) * 1000)
* print('rates for nsd: ' + nsd + ': ' + rates)
*/
static const uint64_t ht_vht_rates[4][10] = {
[OFDM_CHANNEL_WIDTH_20MHZ] = {
6500000ULL, 13000000ULL, 19500000ULL, 26000000ULL,
39000000ULL, 52000000ULL, 58500000ULL, 65000000ULL,
78000000ULL, 86666000ULL },
[OFDM_CHANNEL_WIDTH_40MHZ] = {
13500000ULL, 27000000ULL, 40500000ULL, 54000000ULL,
81000000ULL, 108000000ULL, 121500000ULL, 135000000ULL,
162000000ULL, 180000000ULL, },
[OFDM_CHANNEL_WIDTH_80MHZ] = {
29250000ULL, 58500000ULL, 87750000ULL, 117000000ULL,
175500000ULL, 234000000ULL, 263250000ULL, 292500000ULL,
351000000ULL, 390000000ULL, },
[OFDM_CHANNEL_WIDTH_160MHZ] = {
58500000ULL, 117000000ULL, 175500000ULL, 234000000ULL,
351000000ULL, 468000000ULL, 526500000ULL, 585000000ULL,
702000000ULL, 780000000ULL,
}
};
/*
* Both HT and VHT rates are calculated in the same fashion. The only difference
* is a relative MCS index is used for HT since, for each NSS, the formula
* is the same with relative index's. This is why this is called with index % 8
* for HT, but not VHT.
*/
bool band_ofdm_rate(uint8_t index, enum ofdm_channel_width width,
int32_t rssi, uint8_t nss, bool sgi,
uint64_t *data_rate)
{
uint64_t rate;
int32_t width_adjust = width * 3;
if (rssi < ht_vht_he_base_rssi[index] + width_adjust)
return false;
rate = ht_vht_rates[width][index];
if (sgi)
rate = rate / 9 * 10;
rate *= nss;
*data_rate = rate;
return true;
}
static bool find_best_mcs_ht(const struct band *band,
const uint8_t *tx_mcs_set,
uint8_t max_mcs, enum ofdm_channel_width width,
int32_t rssi, bool sgi,
uint64_t *out_data_rate)
{
int i;
/*
* TODO: Support MCS values 32 - 76
*
* The MCS values > 31 use an unequal modulation, and the number of
* supported MCS indexes per NSS differs. We do not consider them
* here for now to keep things simple(r).
*/
for (i = max_mcs; i >= 0; i--) {
if (!test_bit(band->ht_mcs_set, i))
continue;
if (!test_bit(tx_mcs_set, i))
continue;
if (band_ofdm_rate(i % 8, width, rssi,
(i / 8) + 1, sgi, out_data_rate))
return true;
}
return false;
}
int band_estimate_ht_rx_rate(const struct band *band,
const uint8_t *htc, const uint8_t *hto,
int32_t rssi, uint64_t *out_data_rate)
{
uint8_t channel_offset;
int max_mcs = 31;
bool sgi;
uint8_t unequal_tx_mcs_set[16];
const uint8_t *tx_mcs_set;
if (!band->ht_supported)
return -ENOTSUP;
if (!htc || !hto)
return -ENOTSUP;
memset(unequal_tx_mcs_set, 0, sizeof(unequal_tx_mcs_set));
tx_mcs_set = htc + 5;
/*
* Check 'Tx MCS Set Defined' at bit 96 and 'Tx MCS Set Unequal' at
* bit 97 of the Supported MCS Set field. Also extract 'Tx Maximum
* Number of Spatial Streams Supported' field at bits 98 and 99.
*
* Note 44 on page 1662 of 802.11-2016 states:
* "How a non-AP STA determines an AP's HT MCS transmission support,
* if the Tx MCS Set subfield in the HT Capabilities element
* advertised by the AP is equal to 0 or if he Tx Rx MCS Set Not Equal
* subfield in that element is equal to 1, is implementation dependent.
* The non-AP STA might conservatively use the basic HT-MCS set, or it
* might use knowledge of past transmissions by the AP, or it might
* use other means.
*/
if (test_bit(tx_mcs_set, 96)) {
if (test_bit(tx_mcs_set, 97)) {
uint8_t max_nss = bit_field(tx_mcs_set[12], 2, 2);
max_mcs = max_nss * 4 + 7;
/*
* For purposes of finding the best MCS below, assume
* the AP can send any MCS up to max_nss (i.e 0-7 for
* 1 nss, 0-15 for 2 nss, 0-23 for 3 nss, 0-31 for 4
*/
memset(unequal_tx_mcs_set, 0xff, max_nss + 1);
tx_mcs_set = unequal_tx_mcs_set;
}
} else
max_mcs = 7;
/* Test for 40 Mhz operation */
channel_offset = bit_field(hto[3], 0, 2);
if (test_bit(hto + 3, 2) &&
(channel_offset == 1 || channel_offset == 3)) {
sgi = test_bit(band->ht_capabilities, 6) &&
test_bit(htc + 2, 6);
if (find_best_mcs_ht(band, tx_mcs_set, max_mcs,
OFDM_CHANNEL_WIDTH_40MHZ,
rssi, sgi, out_data_rate))
return 0;
}
sgi = test_bit(band->ht_capabilities, 5) && test_bit(htc + 2, 5);
if (find_best_mcs_ht(band, tx_mcs_set, max_mcs,
OFDM_CHANNEL_WIDTH_20MHZ,
rssi, sgi, out_data_rate))
return 0;
return -ENETUNREACH;
}
static bool find_best_mcs_vht(uint8_t max_index, enum ofdm_channel_width width,
int32_t rssi, uint8_t nss, bool sgi,
uint64_t *out_data_rate)
{
int i;
/*
* Iterate over all available MCS indexes to find the best one
* we can use. Note that band_ofdm_rate() will return false if a
* given combination cannot be used due to rssi being too low.
*
* Also, Certain MCS/Width/NSS combinations are not valid,
* refer to IEEE 802.11-2016 Section 21.5 for more details
*/
for (i = max_index; i >= 0; i--)
if (band_ofdm_rate(i, width, rssi, nss, sgi, out_data_rate))
return true;
return false;
}
static bool find_best_mcs_nss(const uint8_t *rx_map, const uint8_t *tx_map,
uint8_t value0, uint8_t value1, uint8_t value2,
uint32_t *mcs_out, uint32_t *nss_out)
{
uint32_t nss = 0;
uint32_t max_mcs = 0;
int bitoffset;
for (bitoffset = 14; bitoffset >= 0; bitoffset -= 2) {
uint8_t rx_val = bit_field(rx_map[bitoffset / 8],
bitoffset % 8, 2);
uint8_t tx_val = bit_field(tx_map[bitoffset / 8],
bitoffset % 8, 2);
/*
* 0 indicates support for MCS 0 - value0
* 1 indicates support for MCS 0 - value1
* 2 indicates support for MCS 0 - value2
* 3 indicates no support
*/
if (rx_val == 3 || tx_val == 3)
continue;
/* rx_val/tx_val tells us which value# to use */
max_mcs = minsize(rx_val, tx_val);
switch (max_mcs) {
case 0:
max_mcs = value0;
break;
case 1:
max_mcs = value1;
break;
case 2:
max_mcs = value2;
break;
}
nss = bitoffset / 2 + 1;
break;
}
if (!nss)
return false;
*nss_out = nss;
*mcs_out = max_mcs;
return true;
}
/*
* IEEE 802.11 - Table 9-250
*
* For simplicity, we are ignoring the Extended BSS BW support, per NOTE 11:
*
* NOTE 11-A receiving STA in which dot11VHTExtendedNSSCapable is false will
* ignore the Extended NSS BW Support subfield and effectively evaluate this
* table only at the entries where Extended NSS BW Support is 0.
*
* This also allows us to group the 160/80+80 widths together, since they are
* the same when Extended NSS BW is zero.
*/
int band_estimate_vht_rx_rate(const struct band *band,
const uint8_t *vhtc, const uint8_t *vhto,
const uint8_t *htc, const uint8_t *hto,
int32_t rssi, uint64_t *out_data_rate)
{
uint32_t nss = 0;
uint32_t max_mcs = 7; /* MCS 0-7 for NSS:1 is always supported */
const uint8_t *rx_mcs_map;
const uint8_t *tx_mcs_map;
uint8_t chan_width;
uint8_t channel_offset;
bool sgi;
if (!band->vht_supported || !band->ht_supported)
return -ENOTSUP;
if (!vhtc || !vhto || !htc || !hto)
return -ENOTSUP;
if (vhto[2] > 3)
return -EBADMSG;
/*
* Find the highest NSS/MCS index combination. Since this is used by
* STAs, we try to estimate our 'download' speed from the AP/peer.
* Hence we look at the TX MCS map of the peer and our own RX MCS map
* to find an overlapping combination that works
*/
rx_mcs_map = band->vht_mcs_set;
tx_mcs_map = vhtc + 2 + 8;
if (!find_best_mcs_nss(rx_mcs_map, tx_mcs_map, 7, 8, 9, &max_mcs, &nss))
return -EBADMSG;
/*
* There is no way to know whether a peer would send us packets using
* the short guard interval (SGI.) SGI capability is only used to
* indicate whether the peer can accept packets that we send this way.
* Here we make the assumption that if the peer has the capability to
* accept packets using SGI and we have the capability to do so, then
* SGI will be used
*
* Also, we assume that the highest bandwidth will result in the
* highest rate for any given rssi. Even accounting for invalid
* MCS/Width/NSS combinations, the higher channel width results
* in better data rate at [mcs index - 2] compared to [mcs index] of
* a next lower bandwidth.
*/
/* See if 160 Mhz operation is available */
chan_width = bit_field(band->vht_capabilities[0], 2, 2);
if (chan_width != 1 && chan_width != 2)
goto try_vht80;
/*
* Channel Width is set to 2 or 3, or 1 and
* channel center frequency segment 1 is non-zero
*/
if (vhto[2] == 2 || vhto[2] == 3 || (vhto[2] == 1 && vhto[4])) {
sgi = test_bit(band->vht_capabilities, 6) &&
test_bit(vhtc + 2, 6);
if (find_best_mcs_vht(max_mcs, OFDM_CHANNEL_WIDTH_160MHZ,
rssi, nss, sgi, out_data_rate))
return 0;
}
try_vht80:
if (vhto[2] == 1) {
sgi = test_bit(band->vht_capabilities, 5) &&
test_bit(vhtc + 2, 5);
if (find_best_mcs_vht(max_mcs, OFDM_CHANNEL_WIDTH_80MHZ,
rssi, nss, sgi, out_data_rate))
return 0;
} /* Otherwise, assume 20/40 Operation */
channel_offset = bit_field(hto[3], 0, 2);
/* Test for 40 Mhz operation */
if (test_bit(hto + 3, 2) &&
(channel_offset == 1 || channel_offset == 3)) {
sgi = test_bit(band->ht_capabilities, 6) &&
test_bit(htc + 2, 6);
if (find_best_mcs_vht(max_mcs, OFDM_CHANNEL_WIDTH_40MHZ,
rssi, nss, sgi, out_data_rate))
return 0;
}
sgi = test_bit(band->ht_capabilities, 5) && test_bit(htc + 2, 5);
if (find_best_mcs_vht(max_mcs, OFDM_CHANNEL_WIDTH_20MHZ,
rssi, nss, sgi, out_data_rate))
return 0;
return -ENETUNREACH;
}
/*
* Data Rate for HE is much the same as HT/VHT but some additional MCS indexes
* were added. This mean rfactors, and nbpscs will contain two additional
* values:
*
* rfactors.extend([3/4, 5/6])
* nbpscs.extend([10, 10])
*
* The guard interval also differs:
*
* Tdft = 12.8us
* Tgi = 0.8, 1.6 or 2.3us
*
* The Nsd values for HE are:
*
* Nsd = [234, 468, 980, 1960]
*
* The formula is identical to HT/VHT:
*
* Nsd * Nbpscs * R * Nss / (Tdft + Tgi)
*
* Note: The table below assumes a 0.8us GI. There isn't any way to know what
* GI will be used for an actual connection, so assume the best.
*/
static uint64_t he_rates[4][12] = {
[OFDM_CHANNEL_WIDTH_20MHZ] = {
8600000ULL, 17200000ULL, 25800000ULL, 34400000ULL,
51600000ULL, 68800000ULL, 77400000ULL, 86000000ULL,
103200000ULL, 114700000ULL, 129000000ULL, 143300000ULL,
},
[OFDM_CHANNEL_WIDTH_40MHZ] = {
17200000ULL, 34400000ULL, 51600000ULL, 68800000ULL,
103200000ULL, 137600000ULL, 154900000ULL, 172000000ULL,
206500000ULL, 229400000ULL, 258000000ULL, 286800000ULL,
},
[OFDM_CHANNEL_WIDTH_80MHZ] = {
36000000ULL, 72000000ULL, 108000000ULL, 144100000ULL,
216200000ULL, 288200000ULL, 324300000ULL, 360300000ULL,
432400000ULL, 480400000ULL, 540400000ULL, 600500000ULL,
},
[OFDM_CHANNEL_WIDTH_160MHZ] = {
72000000ULL, 144100000ULL, 216200000ULL, 288200000ULL,
432400000ULL, 576500000ULL, 648500000ULL, 720600000ULL,
864700000ULL, 960800000ULL, 1080900000ULL, 1201000000ULL,
},
};
static bool band_he_rate(uint8_t index, enum ofdm_channel_width width,
int32_t rssi, uint8_t nss, uint64_t *data_rate)
{
uint64_t rate;
int32_t width_adjust;
width_adjust = width * 3;
if (rssi < ht_vht_he_base_rssi[index] + width_adjust)
return false;
rate = he_rates[width][index];
rate *= nss;
*data_rate = rate;
return true;
}
static bool find_rate_he(const uint8_t *rx_map, const uint8_t *tx_map,
enum ofdm_channel_width width, int32_t rssi,
uint64_t *out_data_rate)
{
uint32_t nss;
uint32_t max_mcs;
int i;
if (!find_best_mcs_nss(rx_map, tx_map, 7, 9, 11,
&max_mcs, &nss))
return false;
for (i = max_mcs; i >= 0; i--)
if (band_he_rate(i, width, rssi, nss, out_data_rate))
return true;
return false;
}
/*
* HE data rate is calculated based on 802.11ax - Section 27.5
*/
int band_estimate_he_rx_rate(const struct band *band, const uint8_t *hec,
int32_t rssi, uint64_t *out_data_rate)
{
enum ofdm_channel_width width = OFDM_CHANNEL_WIDTH_20MHZ;
int i;
const struct band_he_capabilities *he_cap = NULL;
const struct l_queue_entry *entry;
const uint8_t *rx_map;
const uint8_t *tx_map;
uint64_t rate = 0;
uint64_t new_rate = 0;
uint8_t width_set;
if (!hec || !band->he_capabilities)
return -EBADMSG;
for (entry = l_queue_get_entries(band->he_capabilities);
entry; entry = entry->next) {
const struct band_he_capabilities *cap = entry->data;
/*
* TODO: Station type is assumed here since it is the only
* consumer of these data rate estimation APIs. If this
* changes the iftype would need to be passed in.
*/
if (cap->iftypes & (1 << NETDEV_IFTYPE_STATION)) {
he_cap = cap;
break;
}
}
if (!he_cap)
return -ENOTSUP;
/* AND the width sets, giving the widths supported by both */
width_set = bit_field(he_cap->he_phy_capa[0], 1, 7) &
bit_field((hec + 6)[0], 1, 7);
/*
* The HE-MCS maps are 17 bytes into the HE Capabilities IE, and
* alternate RX/TX every 2 bytes. Start the TX map 17 + 2 bytes
* into the MCS set. For each MCS set find the best data rate.
*/
rx_map = he_cap->he_mcs_set;
tx_map = hec + 19;
/*
* 802.11ax Table 9-322b
*
* B3 indicates support for 80+80MHz MCS set
*/
if (test_bit(&width_set, 3)) {
if (find_rate_he(rx_map + 8, tx_map + 8,
OFDM_CHANNEL_WIDTH_160MHZ,
rssi, &new_rate))
rate = new_rate;
}
/* B2 indicates support for 160MHz MCS set */
if (test_bit(&width_set, 2)) {
if (find_rate_he(rx_map + 4, tx_map + 4,
OFDM_CHANNEL_WIDTH_160MHZ,
rssi, &new_rate) && new_rate > rate)
rate = new_rate;
}
/* B1 indicates support for 80MHz */
if (test_bit(&width_set, 1))
width = OFDM_CHANNEL_WIDTH_80MHZ;
/* B0 indicates support for 40MHz */
if (test_bit(&width_set, 0))
width = OFDM_CHANNEL_WIDTH_40MHZ;
/* <= 80MHz MCS set */
for (i = width; i >= OFDM_CHANNEL_WIDTH_20MHZ; i--) {
if (find_rate_he(rx_map, tx_map, i, rssi, &new_rate)) {
if (new_rate > rate)
rate = new_rate;
break;
}
}
if (!rate)
return -EBADMSG;
*out_data_rate = rate;
return 0;
}
static int band_channel_info_get_bandwidth(const struct band_chandef *info)
{
switch (info->channel_width) {
case BAND_CHANDEF_WIDTH_20NOHT:
case BAND_CHANDEF_WIDTH_20:
return 20;
case BAND_CHANDEF_WIDTH_40:
return 40;
case BAND_CHANDEF_WIDTH_80:
return 80;
case BAND_CHANDEF_WIDTH_80P80:
case BAND_CHANDEF_WIDTH_160:
return 160;
default:
break;
}
return -ENOTSUP;
}
struct operating_class_info {
uint32_t starting_frequency;
uint32_t flags;
uint8_t channel_set[60];
uint8_t center_frequencies[30];
uint16_t channel_spacing;
uint8_t operating_class;
};
enum operating_class_flags {
PRIMARY_CHANNEL_UPPER = 0x1,
PRIMARY_CHANNEL_LOWER = 0x2,
PLUS80 = 0x4,
};
static const struct operating_class_info e4_operating_classes[] = {
{
.operating_class = 81,
.starting_frequency = 2407,
.channel_set = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 },
.channel_spacing = 20,
},
{
.operating_class = 82,
.starting_frequency = 2414,
.channel_set = { 14 },
.channel_spacing = 20,
},
{
.operating_class = 83,
.starting_frequency = 2407,
.channel_set = { 1, 2, 3, 4, 5, 6, 7, 8, 9 },
.channel_spacing = 40,
.flags = PRIMARY_CHANNEL_LOWER,
},
{
.operating_class = 84,
.starting_frequency = 2407,
.channel_set = { 5, 6, 7, 8, 9, 10, 11, 12, 13 },
.channel_spacing = 40,
.flags = PRIMARY_CHANNEL_UPPER,
},
{
.operating_class = 115,
.starting_frequency = 5000,
.channel_set = { 36, 40, 44, 48},
.channel_spacing = 20,
},
{
.operating_class = 116,
.starting_frequency = 5000,
.channel_set = { 36, 44 },
.channel_spacing = 40,
.flags = PRIMARY_CHANNEL_LOWER,
},
{
.operating_class = 117,
.starting_frequency = 5000,
.channel_set = { 40, 48 },
.channel_spacing = 40,
.flags = PRIMARY_CHANNEL_UPPER,
},
{
.operating_class = 118,
.starting_frequency = 5000,
.channel_set = { 52, 56, 60, 64},
.channel_spacing = 20,
},
{
.operating_class = 119,
.starting_frequency = 5000,
.channel_set = { 52, 60 },
.channel_spacing = 40,
.flags = PRIMARY_CHANNEL_LOWER,
},
{
.operating_class = 120,
.starting_frequency = 5000,
.channel_set = { 56, 64 },
.channel_spacing = 40,
.flags = PRIMARY_CHANNEL_UPPER,
},
{
.operating_class = 121,
.starting_frequency = 5000,
.channel_set = { 100, 104, 108, 112, 116, 120,
124, 128, 132, 136, 140, 144 },
.channel_spacing = 20,
},
{
.operating_class = 122,
.starting_frequency = 5000,
.channel_set = { 100, 108, 116, 124, 132, 140},
.channel_spacing = 40,
.flags = PRIMARY_CHANNEL_LOWER,
},
{
.operating_class = 123,
.starting_frequency = 5000,
.channel_set = { 104, 112, 120, 128, 136, 144 },
.channel_spacing = 40,
.flags = PRIMARY_CHANNEL_UPPER,
},
{
.operating_class = 124,
.starting_frequency = 5000,
.channel_set = { 149, 153, 157, 161 },
.channel_spacing = 20,
},
{
.operating_class = 125,
.starting_frequency = 5000,
.channel_set = { 149, 153, 157, 161, 165, 169, 173, 177 },
.channel_spacing = 20,
},
{
.operating_class = 126,
.starting_frequency = 5000,
.channel_set = { 149, 157, 165, 173 },
.channel_spacing = 40,
.flags = PRIMARY_CHANNEL_LOWER,
},
{
.operating_class = 127,
.starting_frequency = 5000,
.channel_set = { 153, 161, 169, 177 },
.channel_spacing = 40,
.flags = PRIMARY_CHANNEL_UPPER,
},
{
.operating_class = 128,
.starting_frequency = 5000,
.channel_spacing = 80,
.center_frequencies = { 42, 58, 106, 122, 138, 155, 171 },
},
{
.operating_class = 129,
.starting_frequency = 5000,
.channel_spacing = 160,
.center_frequencies = { 50, 114, 163 },
},
{
.operating_class = 130,
.starting_frequency = 5000,
.channel_spacing = 80,
.center_frequencies = { 42, 58, 106, 122, 138, 155, 171 },
.flags = PLUS80,
},
{
.operating_class = 131,
.starting_frequency = 5950,
.channel_spacing = 20,
.channel_set = { 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45,
49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93,
97, 101, 105, 109, 113, 117, 121, 125, 129, 133,
137, 141, 145, 149, 153, 157, 161, 165, 169,
173, 177, 181, 185, 189, 193, 197, 201, 205,
209, 213, 217, 221, 225, 229, 233 },
},
{
.operating_class = 132,
.starting_frequency = 5950,
.channel_spacing = 40,
.center_frequencies = { 3, 11, 19, 27, 35, 43, 51, 59, 67, 75,
83, 91, 99, 107, 115, 123, 131, 139,
147, 155, 163, 171, 179, 187, 195, 203,
211, 219, 227 },
},
{
.operating_class = 133,
.starting_frequency = 5950,
.channel_spacing = 80,
.center_frequencies = { 7, 23, 39, 55, 71, 87, 103, 119, 135,
151, 167, 183, 199, 215 },
},
{
.operating_class = 134,
.starting_frequency = 5950,
.channel_spacing = 160,
.center_frequencies = { 15, 47, 79, 111, 143, 175, 207 },
},
{
.operating_class = 135,
.starting_frequency = 5950,
.channel_spacing = 80,
.center_frequencies = { 7, 23, 39, 55, 71, 87, 102, 119, 135,
151, 167, 183, 199, 215 },
.flags = PLUS80,
},
{
.operating_class = 136,
.starting_frequency = 5950,
.channel_spacing = 20,
.center_frequencies = { 2 },
}
};
static const struct operating_class_info *e4_find_opclass(uint32_t opclass)
{
unsigned int i;
for (i = 0; i < L_ARRAY_SIZE(e4_operating_classes); i++) {
if (e4_operating_classes[i].operating_class != opclass)
continue;
return &e4_operating_classes[i];
}
return NULL;
}
static int e4_channel_to_frequency(const struct operating_class_info *info,
uint32_t channel)
{
unsigned int i;
unsigned int offset;
for (i = 0; info->channel_set[i] &&
i < L_ARRAY_SIZE(info->channel_set); i++) {
if (info->channel_set[i] != channel)
continue;
return channel * 5 + info->starting_frequency;
}
/*
* Only classes in Table E4 with center frequencies are 128-130,
* which use 20 Mhz wide channels. Since E4 gives a center frequency,
* calculate the channel offset based on channel spacing.
*
* Typically +/- 6 for 80 Mhz channels and +/- 14 for 160 Mhz channels
*/
offset = (info->channel_spacing - 20) / 5 / 2;
/*
* Check that the channel is in the frequency range given by one of
* the center frequencies listed for the operating class. The channel
* must be a valid channel for a lower operating class and spaced
* 20 mhz apart
*/
for (i = 0; info->center_frequencies[i] &&
i < L_ARRAY_SIZE(info->center_frequencies); i++) {
unsigned int upper = info->center_frequencies[i] + offset;
unsigned int j = info->center_frequencies[i] - offset;
while (j <= upper && channel >= j) {
if (channel == j)
return channel * 5 + info->starting_frequency;
j += 4;
}
}
return -EINVAL;
}
static int e4_frequency_to_channel(const struct operating_class_info *info,
uint32_t frequency)
{
return (frequency - info->starting_frequency) / 5;
}
static int e4_has_frequency(const struct operating_class_info *info,
uint32_t frequency)
{
unsigned int i;
unsigned int channel = e4_frequency_to_channel(info, frequency);
for (i = 0; info->channel_set[i] &&
i < L_ARRAY_SIZE(info->channel_set); i++) {
if (info->channel_set[i] != channel)
continue;
return 0;
}
return -ENOENT;
}
static int e4_has_ccfi(const struct operating_class_info *info,
uint32_t center_frequency)
{
unsigned int i;
unsigned int ccfi = e4_frequency_to_channel(info, center_frequency);
for (i = 0; info->center_frequencies[i] &&
i < L_ARRAY_SIZE(info->center_frequencies); i++) {
if (info->center_frequencies[i] != ccfi)
continue;
return 0;
}
return -ENOENT;
}
static int e4_class_matches(const struct operating_class_info *info,
const struct band_chandef *chandef)
{
int own_bandwidth = band_channel_info_get_bandwidth(chandef);
int r;
if (own_bandwidth < 0)
return own_bandwidth;
switch (chandef->channel_width) {
case BAND_CHANDEF_WIDTH_20NOHT:
case BAND_CHANDEF_WIDTH_20:
case BAND_CHANDEF_WIDTH_40:
if (own_bandwidth != info->channel_spacing)
return -ENOENT;
if (own_bandwidth == 40) {
uint32_t behavior;
if (chandef->center1_frequency > chandef->frequency)
behavior = PRIMARY_CHANNEL_LOWER;
else
behavior = PRIMARY_CHANNEL_UPPER;
if ((info->flags & behavior) != behavior)
return -ENOENT;
}
return e4_has_frequency(info, chandef->frequency);
case BAND_CHANDEF_WIDTH_80:
case BAND_CHANDEF_WIDTH_160:
if (info->flags & PLUS80)
return -ENOENT;
if (own_bandwidth != info->channel_spacing)
return -ENOENT;
return e4_has_ccfi(info, chandef->center1_frequency);
case BAND_CHANDEF_WIDTH_80P80:
if (!(info->flags & PLUS80))
return -ENOENT;
r = e4_has_ccfi(info, chandef->center1_frequency);
if (r < 0)
return r;
return e4_has_ccfi(info, chandef->center2_frequency);
default:
break;
}
return -ENOTSUP;
}
int oci_to_frequency(uint32_t operating_class, uint32_t channel)
{
const struct operating_class_info *info;
info = e4_find_opclass(operating_class);
if (!info)
return -ENOENT;
return e4_channel_to_frequency(info, channel);
}
int oci_verify(const uint8_t oci[static 3], const struct band_chandef *own)
{
const struct operating_class_info *info;
int oci_frequency;
int own_bandwidth;
int oci_bandwidth;
info = e4_find_opclass(oci[0]);
if (!info)
return -ENOENT;
/*
* 802.11-2020, 12.2.9:
* Verifying that the maximum bandwidth used by the STA to transmit or
* receive PPDUs to/from the peer STA from which the OCI was received
* is no greater than the bandwidth of the operating class specified
* in the Operating Class field of the received OCI
*/
own_bandwidth = band_channel_info_get_bandwidth(own);
if (own_bandwidth < 0)
return own_bandwidth;
oci_bandwidth = info->channel_spacing;
if (info->flags & PLUS80)
oci_bandwidth *= 2;
if (own_bandwidth > oci_bandwidth)
return -EPERM;
/*
* 802.11-2020, 12.2.9:
* Verifying that the primary channel used by the STA to transmit or
* receive PPDUs to/from the peer STA from which the OCI was received
* is equal to the Primary Channel Number field (for the corresponding
* operating class)
*/
oci_frequency = e4_channel_to_frequency(info, oci[1]);
if (oci_frequency < 0)
return oci_frequency;
if (oci_frequency != (int) own->frequency)
return -EPERM;
/*
* 802.11-2020, 12.2.9:
* Verifying that, when 40 MHz bandwidth is used by the STA to transmit
* or receive PPDUs to/from the peer STA from which the OCI was
* received, the nonprimary 20 MHz used matches the operating class
* (i.e., upper/lower behavior) specified in the Operating Class field
* of the received OCI
*
* NOTE: For now we only check this if the STA and peer are operating
* on 40 Mhz channels. If the STA is operating on 40 Mhz while the
* peer is operating on 80 or 160 Mhz wide channels, then only the
* primary channel validation is performed
*
* With 6GHz operating classes there is no concept of upper/lower 40mhz
* channels, therefore this special handling list not needed.
*/
if (own_bandwidth == 40 && oci_bandwidth == 40 &&
info->operating_class < 131) {
uint32_t behavior;
/*
* - Primary Channel Upper Behavior -> Secondary channel below
* primary channel. Or HT40MINUS.
* - Primary Channel Lower Behavior -> Secondary channel above
* primary channel. Or HT40PLUS.
*/
if (own->center1_frequency > own->frequency)
behavior = PRIMARY_CHANNEL_LOWER;
else
behavior = PRIMARY_CHANNEL_UPPER;
if ((info->flags & behavior) != behavior)
return -EPERM;
}
/*
* 802.11-2020, 12.2.9:
* Verifying that, if operating an 80+80 MHz operating class, the
* frequency segment 1 channel number used by the STA to transmit or
* receive PPDUs to/from the peer STA from which the OCI was received
* is equal to the Frequency Segment 1 Channel Number field of the OCI.
*/
if (own->channel_width == BAND_CHANDEF_WIDTH_80P80) {
uint32_t freq_segment1_chan_num;
if (!(info->flags & PLUS80))
return -EPERM;
freq_segment1_chan_num =
e4_frequency_to_channel(info, own->center2_frequency);
if (freq_segment1_chan_num != oci[2])
return -EPERM;
}
return 0;
}
int oci_from_chandef(const struct band_chandef *own, uint8_t oci[static 3])
{
unsigned int i;
for (i = 0; i < L_ARRAY_SIZE(e4_operating_classes); i++) {
const struct operating_class_info *info =
&e4_operating_classes[i];
if (e4_class_matches(info, own) < 0)
continue;
oci[0] = info->operating_class;
oci[1] = e4_frequency_to_channel(info, own->frequency);
if (own->center2_frequency)
oci[2] = e4_frequency_to_channel(info,
own->center2_frequency);
else
oci[2] = 0;
return 0;
}
return -ENOENT;
}
/* Find an HT chandef for the frequency */
int band_freq_to_ht_chandef(uint32_t freq, const struct band_freq_attrs *attr,
struct band_chandef *chandef)
{
enum band_freq band;
enum band_chandef_width width;
unsigned int i;
const struct operating_class_info *best = NULL;
if (attr->disabled || !attr->supported)
return -EINVAL;
if (!band_freq_to_channel(freq, &band))
return -EINVAL;
for (i = 0; i < L_ARRAY_SIZE(e4_operating_classes); i++) {
const struct operating_class_info *info =
&e4_operating_classes[i];
enum band_chandef_width w;
if (e4_has_frequency(info, freq) < 0)
continue;
/* Any restrictions for this channel width? */
switch (info->channel_spacing) {
case 20:
w = BAND_CHANDEF_WIDTH_20;
break;
case 40:
w = BAND_CHANDEF_WIDTH_40;
/* 6GHz remove the upper/lower 40mhz channel concept */
if (band == BAND_FREQ_6_GHZ)
break;
if (info->flags & PRIMARY_CHANNEL_LOWER &&
attr->no_ht40_plus)
continue;
if (info->flags & PRIMARY_CHANNEL_UPPER &&
attr->no_ht40_minus)
continue;
break;
default:
continue;
}
if (!best || best->channel_spacing < info->channel_spacing) {
best = info;
width = w;
}
}
if (!best)
return -ENOENT;
chandef->frequency = freq;
chandef->channel_width = width;
/*
* Choose a secondary channel frequency:
* - 20mhz no secondary
* - 40mhz we can base the selection off the channel flags, either
* higher or lower.
*/
_Pragma("GCC diagnostic push")
_Pragma("GCC diagnostic ignored \"-Wmaybe-uninitialized\"")
switch (width) {
_Pragma("GCC diagnostic pop")
case BAND_CHANDEF_WIDTH_20:
return 0;
case BAND_CHANDEF_WIDTH_40:
if (band == BAND_FREQ_6_GHZ)
return 0;
if (best->flags & PRIMARY_CHANNEL_UPPER)
chandef->center1_frequency = freq - 10;
else
chandef->center1_frequency = freq + 10;
return 0;
default:
/* Should never happen */
return -EINVAL;
}
return 0;
}
uint8_t band_freq_to_channel(uint32_t freq, enum band_freq *out_band)
{
unsigned int i;
enum band_freq band = 0;
uint32_t channel = 0;
if (freq >= 2412 && freq <= 2484) {
if (freq == 2484)
channel = 14;
else {
channel = freq - 2407;
if (channel % 5)
return 0;
channel /= 5;
}
band = BAND_FREQ_2_4_GHZ;
goto check_e4;
}
if (freq >= 5005 && freq < 5900) {
if (freq % 5)
return 0;
channel = (freq - 5000) / 5;
band = BAND_FREQ_5_GHZ;
goto check_e4;
}
if (freq >= 4905 && freq < 5000) {
if (freq % 5)
return 0;
channel = (freq - 4000) / 5;
band = BAND_FREQ_5_GHZ;
goto check_e4;
}
if (freq > 5950 && freq <= 7115) {
if (freq % 5)
return 0;
channel = (freq - 5950) / 5;
band = BAND_FREQ_6_GHZ;
goto check_e4;
}
if (freq == 5935) {
band = BAND_FREQ_6_GHZ;
channel = 2;
}
if (!band || !channel)
return 0;
check_e4:
for (i = 0; i < L_ARRAY_SIZE(e4_operating_classes); i++) {
const struct operating_class_info *info =
&e4_operating_classes[i];
if (e4_has_frequency(info, freq) == 0 ||
e4_has_ccfi(info, freq) == 0) {
if (out_band)
*out_band = band;
return channel;
}
}
return 0;
}
uint32_t band_channel_to_freq(uint8_t channel, enum band_freq band)
{
unsigned int i;
uint32_t freq = 0;
if (band == BAND_FREQ_2_4_GHZ) {
if (channel >= 1 && channel <= 13)
freq = 2407 + 5 * channel;
else if (channel == 14)
freq = 2484;
goto check_e4;
}
if (band == BAND_FREQ_5_GHZ) {
if (channel >= 1 && channel <= 179)
freq = 5000 + 5 * channel;
else if (channel >= 181 && channel <= 199)
freq = 4000 + 5 * channel;
goto check_e4;
}
if (band == BAND_FREQ_6_GHZ) {
/* operating class 136 */
if (channel == 2) {
freq = 5935;
goto check_e4;
}
/* Channels increment by 4, starting with 1 */
if (channel % 4 != 1)
return 0;
if (channel < 1 || channel > 233)
return 0;
/* operating classes 131, 132, 133, 134, 135 */
freq = 5950 + 5 * channel;
}
check_e4:
for (i = 0; i < L_ARRAY_SIZE(e4_operating_classes); i++) {
const struct operating_class_info *info =
&e4_operating_classes[i];
if (e4_has_frequency(info, freq) == 0 ||
e4_has_ccfi(info, freq) == 0)
return freq;
}
return 0;
}
static const char *const oper_class_us_codes[] = {
"US", "CA"
};
static const char *const oper_class_eu_codes[] = {
"AL", "AM", "AT", "AZ", "BA", "BE", "BG", "BY", "CH", "CY", "CZ", "DE",
"DK", "EE", "EL", "ES", "FI", "FR", "GE", "HR", "HU", "IE", "IS", "IT",
"LI", "LT", "LU", "LV", "MD", "ME", "MK", "MT", "NL", "NO", "PL", "PT",
"RO", "RS", "RU", "SE", "SI", "SK", "TR", "UA", "UK"
};
/* Annex E, table E-1 */
static const uint8_t oper_class_us_to_global[] = {
[1] = 115, [2] = 118, [3] = 124, [4] = 121,
[5] = 125, [6] = 103, [7] = 103, [8] = 102,
[9] = 102, [10] = 101, [11] = 101, [12] = 81,
[13] = 94, [14] = 95, [15] = 96, [22] = 116,
[23] = 119, [24] = 122, [25] = 126, [26] = 126,
[27] = 117, [28] = 120, [29] = 123, [30] = 127,
[31] = 127, [32] = 83, [33] = 84, [34] = 180,
/* 128 - 130 is a 1 to 1 mapping */
};
/* Annex E, table E-2 */
static const uint8_t oper_class_eu_to_global[] = {
[1] = 115, [2] = 118, [3] = 121, [4] = 81,
[5] = 116, [6] = 119, [7] = 122, [8] = 117,
[9] = 120, [10] = 123, [11] = 83, [12] = 84,
[17] = 125, [18] = 130,
/* 128 - 130 is a 1 to 1 mapping */
};
/* Annex E, table E-3 */
static const uint8_t oper_class_jp_to_global[] = {
[1] = 115, [2] = 112, [3] = 112, [4] = 112,
[5] = 112, [6] = 112, [7] = 109, [8] = 109,
[9] = 109, [10] = 109, [11] = 109, [12] = 113,
[13] = 113, [14] = 113, [15] = 113, [16] = 110,
[17] = 110, [18] = 110, [19] = 110, [20] = 110,
[21] = 114, [22] = 114, [23] = 114, [24] = 114,
[25] = 111, [26] = 111, [27] = 111, [28] = 111,
[29] = 111, [30] = 81, [31] = 82, [32] = 118,
[33] = 118, [34] = 121, [35] = 121, [36] = 116,
[37] = 119, [38] = 119, [39] = 122, [40] = 122,
[41] = 117, [42] = 120, [43] = 120, [44] = 123,
[45] = 123, [46] = 104, [47] = 104, [48] = 104,
[49] = 104, [50] = 104, [51] = 105, [52] = 105,
[53] = 105, [54] = 105, [55] = 105, [56] = 83,
[57] = 84, [58] = 121, [59] = 180,
/* 128 - 130 is a 1 to 1 mapping */
};
/* Annex E, table E-4 (only 2.4GHz, 4.9 / 5GHz, and 6GHz bands) */
static const enum band_freq oper_class_to_band_global[] = {
[81 ... 84] = BAND_FREQ_2_4_GHZ,
[104 ... 130] = BAND_FREQ_5_GHZ,
[131 ... 136] = BAND_FREQ_6_GHZ,
};
/* Annex E, table E-5 */
static const uint8_t oper_class_cn_to_global[] = {
[1] = 115, [2] = 118, [3] = 125, [4] = 116,
[5] = 119, [6] = 126, [7] = 81, [8] = 83,
[9] = 84,
/* 128 - 130 is a 1 to 1 mapping */
};
enum band_freq band_oper_class_to_band(const uint8_t *country,
uint8_t oper_class)
{
unsigned int i;
int table = 0;
if (country && country[2] >= 1 && country[2] <= 5)
table = country[2];
else if (country) {
for (i = 0; i < L_ARRAY_SIZE(oper_class_us_codes); i++)
if (!memcmp(oper_class_us_codes[i], country, 2)) {
/* Use table E-1 */
table = 1;
break;
}
for (i = 0; i < L_ARRAY_SIZE(oper_class_eu_codes); i++)
if (!memcmp(oper_class_eu_codes[i], country, 2)) {
/* Use table E-2 */
table = 2;
break;
}
if (!memcmp("JP", country, 2))
/* Use table E-3 */
table = 3;
if (!memcmp("CN", country, 2))
/* Use table E-5 */
table = 5;
}
switch (table) {
case 1:
if (oper_class < L_ARRAY_SIZE(oper_class_us_to_global))
oper_class = oper_class_us_to_global[oper_class];
break;
case 2:
if (oper_class < L_ARRAY_SIZE(oper_class_eu_to_global))
oper_class = oper_class_eu_to_global[oper_class];
break;
case 3:
if (oper_class < L_ARRAY_SIZE(oper_class_jp_to_global))
oper_class = oper_class_jp_to_global[oper_class];
break;
case 5:
if (oper_class < L_ARRAY_SIZE(oper_class_cn_to_global))
oper_class = oper_class_cn_to_global[oper_class];
break;
}
if (oper_class < L_ARRAY_SIZE(oper_class_to_band_global))
return oper_class_to_band_global[oper_class];
else
return 0;
}
const char *band_chandef_width_to_string(enum band_chandef_width width)
{
switch (width) {
case BAND_CHANDEF_WIDTH_20NOHT:
return "20MHz (no-HT)";
case BAND_CHANDEF_WIDTH_20:
return "20MHz";
case BAND_CHANDEF_WIDTH_40:
return "40MHz";
case BAND_CHANDEF_WIDTH_80:
return "80MHz";
case BAND_CHANDEF_WIDTH_80P80:
return "80+80MHz";
case BAND_CHANDEF_WIDTH_160:
return "160MHz";
}
return NULL;
}
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