From 80ce804e88247bb0409d131c5882808a0ce9bba4 Mon Sep 17 00:00:00 2001 From: Jouni Malinen Date: Fri, 5 Feb 2016 17:06:06 +0200 Subject: [PATCH] WNM: Workaround for broken AP operating class behavior Some APs do not advertise operating classes correctly for BSS Transition Management. Try to determine the most likely operating frequency based on the channel number (1..14 --> 2.4 GHz; 36..169 --> 5 GHz) if invalid op_class == 0 is received in a BSS Transition Management Request. This speeds up the following operating by avoiding a full scan due to an unknown channel. Signed-off-by: Jouni Malinen --- wpa_supplicant/wnm_sta.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/wpa_supplicant/wnm_sta.c b/wpa_supplicant/wnm_sta.c index e1596cbb8..ffc9052f4 100644 --- a/wpa_supplicant/wnm_sta.c +++ b/wpa_supplicant/wnm_sta.c @@ -429,6 +429,7 @@ static int wnm_nei_get_chan(struct wpa_supplicant *wpa_s, u8 op_class, u8 chan) { struct wpa_bss *bss = wpa_s->current_bss; const char *country = NULL; + int freq; if (bss) { const u8 *elem = wpa_bss_get_ie(bss, WLAN_EID_COUNTRY); @@ -437,7 +438,21 @@ static int wnm_nei_get_chan(struct wpa_supplicant *wpa_s, u8 op_class, u8 chan) country = (const char *) (elem + 2); } - return ieee80211_chan_to_freq(country, op_class, chan); + freq = ieee80211_chan_to_freq(country, op_class, chan); + if (freq <= 0 && op_class == 0) { + /* + * Some APs do not advertise correct operating class + * information. Try to determine the most likely operating + * frequency based on the channel number. + */ + if (chan >= 1 && chan <= 13) + freq = 2407 + chan * 5; + else if (chan == 14) + freq = 2484; + else if (chan >= 36 && chan <= 169) + freq = 5000 + chan * 5; + } + return freq; }