int check_40mhz_2g4(struct hostapd_hw_modes *mode,
struct wpa_scan_results *scan_res, int pri_chan,
int sec_chan)
{
int pri_freq, sec_freq;
int affected_start, affected_end;
size_t i;
if (!mode || !scan_res || !pri_chan || !sec_chan ||
pri_chan == sec_chan)
return 0;
pri_freq = hw_get_freq(mode, pri_chan);
sec_freq = hw_get_freq(mode, sec_chan);
affected_start = (pri_freq + sec_freq) / 2 - 25;
affected_end = (pri_freq + sec_freq) / 2 + 25;
wpa_printf(MSG_DEBUG, "40 MHz affected channel range: [%d,%d] MHz",
affected_start, affected_end);
for (i = 0; i < scan_res->num; i++) {
struct wpa_scan_res *bss = scan_res->res[i];
int pri = bss->freq;
int sec = pri;
struct ieee802_11_elems elems;
/* Check for overlapping 20 MHz BSS */
if (check_20mhz_bss(bss, pri_freq, affected_start,
affected_end)) {
wpa_printf(MSG_DEBUG,
"Overlapping 20 MHz BSS is found");
return 0;
}
get_pri_sec_chan(bss, &pri_chan, &sec_chan);
if (sec_chan) {
if (sec_chan < pri_chan)
sec = pri - 20;
else
sec = pri + 20;
}
if ((pri < affected_start || pri > affected_end) &&
(sec < affected_start || sec > affected_end))
continue; /* not within affected channel range */
wpa_printf(MSG_DEBUG, "Neighboring BSS: " MACSTR
" freq=%d pri=%d sec=%d",
MAC2STR(bss->bssid), bss->freq, pri_chan, sec_chan);
if (sec_chan) {
if (pri_freq != pri || sec_freq != sec) {
wpa_printf(MSG_DEBUG,
"40 MHz pri/sec mismatch with BSS "
MACSTR
" <%d,%d> (chan=%d%c) vs. <%d,%d>",
MAC2STR(bss->bssid),
pri, sec, pri_chan,
sec > pri ? '+' : '-',
pri_freq, sec_freq);
return 0;
}
}
ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems,
0);
if (elems.ht_capabilities) {
struct ieee80211_ht_capabilities *ht_cap =
(struct ieee80211_ht_capabilities *)
elems.ht_capabilities;
if (le_to_host16(ht_cap->ht_capabilities_info) &
HT_CAP_INFO_40MHZ_INTOLERANT) {
wpa_printf(MSG_DEBUG,
"40 MHz Intolerant is set on channel %d in BSS "
MACSTR, pri, MAC2STR(bss->bssid));
return 0;
}
}
}
return 1;
}
int hostapd_hw_get_freq(struct hostapd_data *hapd, int chan)
{
return hw_get_freq(hapd->iface->current_mode, chan);
}
int check_40mhz_5g(struct hostapd_hw_modes *mode,
struct wpa_scan_results *scan_res, int pri_chan,
int sec_chan)
{
int pri_freq, sec_freq, pri_bss, sec_bss;
int bss_pri_chan, bss_sec_chan;
size_t i;
int match;
if (!mode || !scan_res || !pri_chan || !sec_chan ||
pri_chan == sec_chan)
return 0;
pri_freq = hw_get_freq(mode, pri_chan);
sec_freq = hw_get_freq(mode, sec_chan);
/*
* Switch PRI/SEC channels if Beacons were detected on selected SEC
* channel, but not on selected PRI channel.
*/
pri_bss = sec_bss = 0;
for (i = 0; i < scan_res->num; i++) {
struct wpa_scan_res *bss = scan_res->res[i];
if (bss->freq == pri_freq)
pri_bss++;
else if (bss->freq == sec_freq)
sec_bss++;
}
if (sec_bss && !pri_bss) {
wpa_printf(MSG_INFO,
"Switch own primary and secondary channel to get secondary channel with no Beacons from other BSSes");
return 2;
}
/*
* Match PRI/SEC channel with any existing HT40 BSS on the same
* channels that we are about to use (if already mixed order in
* existing BSSes, use own preference).
*/
match = 0;
for (i = 0; i < scan_res->num; i++) {
struct wpa_scan_res *bss = scan_res->res[i];
get_pri_sec_chan(bss, &bss_pri_chan, &bss_sec_chan);
if (pri_chan == bss_pri_chan &&
sec_chan == bss_sec_chan) {
match = 1;
break;
}
}
if (!match) {
for (i = 0; i < scan_res->num; i++) {
struct wpa_scan_res *bss = scan_res->res[i];
get_pri_sec_chan(bss, &bss_pri_chan, &bss_sec_chan);
if (pri_chan == bss_sec_chan &&
sec_chan == bss_pri_chan) {
wpa_printf(MSG_INFO, "Switch own primary and "
"secondary channel due to BSS "
"overlap with " MACSTR,
MAC2STR(bss->bssid));
return 2;
}
}
}
return 1;
}
