From 9c75c3d4ba7c4e45507dbf57712b4aba8251735c Mon Sep 17 00:00:00 2001 From: Adrian Chadd Date: Thu, 18 Dec 2014 05:17:18 +0000 Subject: [PATCH] Fix the scan handling for 11b->11g upgrades in a world where, well, it's not just 11b/11g. The following was happening, and it's quite .. annoyingly grr-y. * create vap, setup wpa_supplicant with no bgscanning, etc - there's no call to ieee80211_media_change, so vap->iv_des_mode is IEEE80211_MODE_AUTO; * do ifconfig wlan0 scan - same thing, media_change doesn't get called, iv_des_mode stays as auto. * But then, run wpa_cli and do 'scan' - it'll do a media change. * if you're on 11ng, vap->iv_des_mode gets changed to IEEE80211_MODE_11NG * Then makescanlist() is called. There's a block of code that gets called if iv_des_mode != IEEE80211_MODE_AUTO, and it does this: if (vap->iv_des_mode != IEEE80211_MODE_11G || mode != IEEE80211_MODE_11B) continue; mode = IEEE80211_MODE_11G; /* upgrade */ * .. now, iv_des_mode is not IEEE80211_MODE_11G, so it always runs 'continue' * .. and thus the scan list stays empty and no further channel scans occur. Ever.(1) If you then disassociate and try associating to something, your scan table has likely been purged / aged out and you'll never see anything in the scan list. (1) You need to do 'ifconfig wlan0 mode auto' or just destroy/re-create the VAP to get working wireless again. Tested: * iwn(4) - intel 5300 wifi; STA mode; using wpa_supplicant; bgscan enabled -and- wpa_supplicant scanning. Thanks to: * Everyone who kept poking me about this and wondering why the hell their wifi would eventually stop seeing scan lists. Grr. I eventually snapped this evening and dug back into this code. --- sys/net80211/ieee80211_scan_sta.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/sys/net80211/ieee80211_scan_sta.c b/sys/net80211/ieee80211_scan_sta.c index 6da06fd1c4d..1e87e35245e 100644 --- a/sys/net80211/ieee80211_scan_sta.c +++ b/sys/net80211/ieee80211_scan_sta.c @@ -600,10 +600,12 @@ makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, * so if the desired mode is 11g, then use * the 11b channel list but upgrade the mode. */ - if (vap->iv_des_mode != IEEE80211_MODE_11G || - mode != IEEE80211_MODE_11B) - continue; - mode = IEEE80211_MODE_11G; /* upgrade */ + if (vap->iv_des_mode == IEEE80211_MODE_11G) { + if (mode == IEEE80211_MODE_11G) /* Skip the G check */ + continue; + else if (mode == IEEE80211_MODE_11B) + mode = IEEE80211_MODE_11G; /* upgrade */ + } } } else { /*