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iwd/src/band.c
James Prestwood d0b9fc84b5 band: check the operating class band before checking e4 
After the band is established we check the e4 table for the channel
that matches. The problem here is we will end up checking all the
operating classes, even those that are not within the band that was
determined. This could result in false positives and return a
channel that doesn't make sense.
2024-10-24 12:11:31 -05:00

1620 lines
41 KiB
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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 -ENOTSUP;
/*
* 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 -ENOTSUP;
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 -ENETUNREACH;
*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 = 5925,
.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 (band != band_oper_class_to_band(NULL,
info->operating_class))
continue;
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", "GB"
};
/* 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 */
};
/*
* Annex C describes the country string encoding.
*
* If it is a country, the first two octets of this string is the two character
* country code as described in document ISO 3166-1. The third octet is one of
* the following:
* 1. an ASCII space character, if the regulations under which the station is
* operating encompass all environments for the current frequency band in
* the country,
* 2. an ASCII 'O' character, if the regulations under which the station is
* operating are for an outdoor environment only, or
* 3. an ASCII 'I' character, if the regulations under which the station is
* operating are for an indoor environment only.
* 4. an ASCII 'X' character, if the station is operating under a noncountry
* entity. The first two octets of the noncountry entity is two ASCII 'XX'
* characters.
* 5. the hexadecimal representation of the Operating Class table number
* currently in use, from the set of tables defined in Annex E, e.g.,
* Table E-1 is represented as x'01'.
*/
static enum band_freq oper_class_to_band(const uint8_t *country,
uint8_t oper_class,
bool ignore_country3)
{
unsigned int i;
int table = 0;
/*
* If a country is set, and the 3rd byte maps to some E-* table in the
* spec use that (case 5). Only caveat here is some APs erroneously set
* this 3rd byte. To work around we can fall back to case 1, where only
* the first two characters are used to lookup the table.
*/
if (!ignore_country3 && country && country[2] >= 1 && country[2] <= 5)
table = country[2];
else if (country) {
/*
* Assuming case 1, although its unlikely you would handle
* cases 2 (O) or 3 (I) any differently. Case 4 (X) is unlikely
* and we really wouldn't have enough information to correctly
* determine the band in some obscure non-country domain.
*/
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;
}
enum band_freq band_oper_class_to_band(const uint8_t *country,
uint8_t oper_class)
{
enum band_freq band = oper_class_to_band(country, oper_class, false);
if (!band) {
/* Fallback with no country string won't change anything */
if (!country)
return 0;
l_warn("Failed to find band with country string '%c%c %u' and "
"oper class %u, trying fallback",
country[0], country[1], country[2], oper_class);
return oper_class_to_band(country, oper_class, true);
}
return band;
}
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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