From 3204795d7a43bcbda8b695dd96d11f3000de7340 Mon Sep 17 00:00:00 2001 From: Sergey Matyukevich Date: Tue, 19 Mar 2019 12:35:56 +0000 Subject: [PATCH] STA OBSS: Add check for overlapping BSSs In the previous implementation connected STA performs OBSS scan according to requests from its 20/40 MHz AP. However STA checks only 40 MHz intolerance subfield from HT Capabilities element in scan results. Meanwhile, as per IEEE Std 802.11-2016, 11.16.12, STA should check overlapping BSSs as well. Note that all the required code to check overlapping BSSs did already exist for AP mode since AP does those checks properly before operating as 20/40 MHz BSS in the 2.4 GHz band. Use that existing code by replace existing 40 MHz intolerance check in sme_proc_obss_scan() with the new shared helper function check_bss_coex_40mhz(). Signed-off-by: Sergey Matyukevich --- wpa_supplicant/events.c | 2 +- wpa_supplicant/sme.c | 42 ++++++++++++++++++++++++++++------------- wpa_supplicant/sme.h | 6 ++++-- 3 files changed, 34 insertions(+), 16 deletions(-) diff --git a/wpa_supplicant/events.c b/wpa_supplicant/events.c index 9d808c55d..f034e5040 100644 --- a/wpa_supplicant/events.c +++ b/wpa_supplicant/events.c @@ -1921,7 +1921,7 @@ static int _wpa_supplicant_event_scan_results(struct wpa_supplicant *wpa_s, if (wnm_scan_process(wpa_s, 1) > 0) goto scan_work_done; - if (sme_proc_obss_scan(wpa_s) > 0) + if (sme_proc_obss_scan(wpa_s, scan_res) > 0) goto scan_work_done; if (own_request && data && diff --git a/wpa_supplicant/sme.c b/wpa_supplicant/sme.c index 749802496..08d7e3ece 100644 --- a/wpa_supplicant/sme.c +++ b/wpa_supplicant/sme.c @@ -13,6 +13,7 @@ #include "common/ieee802_11_defs.h" #include "common/ieee802_11_common.h" #include "common/ocv.h" +#include "common/hw_features_common.h" #include "eapol_supp/eapol_supp_sm.h" #include "common/wpa_common.h" #include "common/sae.h" @@ -2214,13 +2215,14 @@ static void sme_send_2040_bss_coex(struct wpa_supplicant *wpa_s, } -int sme_proc_obss_scan(struct wpa_supplicant *wpa_s) +int sme_proc_obss_scan(struct wpa_supplicant *wpa_s, + struct wpa_scan_results *scan_res) { - struct wpa_bss *bss; const u8 *ie; - u16 ht_cap; u8 chan_list[P2P_MAX_CHANNELS], channel; u8 num_channels = 0, num_intol = 0, i; + size_t j; + int pri_freq, sec_freq; if (!wpa_s->sme.sched_obss_scan) return 0; @@ -2248,22 +2250,36 @@ int sme_proc_obss_scan(struct wpa_supplicant *wpa_s) os_memset(chan_list, 0, sizeof(chan_list)); - dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) { - /* Skip other band bss */ + pri_freq = wpa_s->assoc_freq; + + switch (wpa_s->sme.ht_sec_chan) { + case HT_SEC_CHAN_ABOVE: + sec_freq = pri_freq + 20; + break; + case HT_SEC_CHAN_BELOW: + sec_freq = pri_freq - 20; + break; + case HT_SEC_CHAN_UNKNOWN: + default: + wpa_msg(wpa_s, MSG_WARNING, + "Undefined secondary channel: drop OBSS scan results"); + return 1; + } + + for (j = 0; j < scan_res->num; j++) { + struct wpa_scan_res *bss = scan_res->res[j]; enum hostapd_hw_mode mode; + int res; + + /* Skip other band bss */ mode = ieee80211_freq_to_chan(bss->freq, &channel); if (mode != HOSTAPD_MODE_IEEE80211G && mode != HOSTAPD_MODE_IEEE80211B) continue; - ie = wpa_bss_get_ie(bss, WLAN_EID_HT_CAP); - ht_cap = (ie && (ie[1] == 26)) ? WPA_GET_LE16(ie + 2) : 0; - wpa_printf(MSG_DEBUG, "SME OBSS scan BSS " MACSTR - " freq=%u chan=%u ht_cap=0x%x", - MAC2STR(bss->bssid), bss->freq, channel, ht_cap); - - if (!ht_cap || (ht_cap & HT_CAP_INFO_40MHZ_INTOLERANT)) { - if (ht_cap & HT_CAP_INFO_40MHZ_INTOLERANT) + res = check_bss_coex_40mhz(bss, pri_freq, sec_freq); + if (res) { + if (res == 2) num_intol++; /* Check whether the channel is already considered */ diff --git a/wpa_supplicant/sme.h b/wpa_supplicant/sme.h index 1a7f9e832..42d5a8317 100644 --- a/wpa_supplicant/sme.h +++ b/wpa_supplicant/sme.h @@ -37,7 +37,8 @@ void sme_disassoc_while_authenticating(struct wpa_supplicant *wpa_s, void sme_clear_on_disassoc(struct wpa_supplicant *wpa_s); void sme_deinit(struct wpa_supplicant *wpa_s); -int sme_proc_obss_scan(struct wpa_supplicant *wpa_s); +int sme_proc_obss_scan(struct wpa_supplicant *wpa_s, + struct wpa_scan_results *scan_res); void sme_sched_obss_scan(struct wpa_supplicant *wpa_s, int enable); void sme_external_auth_trigger(struct wpa_supplicant *wpa_s, union wpa_event_data *data); @@ -112,7 +113,8 @@ static inline void sme_deinit(struct wpa_supplicant *wpa_s) { } -static inline int sme_proc_obss_scan(struct wpa_supplicant *wpa_s) +static inline int sme_proc_obss_scan(struct wpa_supplicant *wpa_s, + struct wpa_scan_results *scan_res) { return 0; }