From af88b9078d4aa31d667d2d82601ede9cae3bac37 Mon Sep 17 00:00:00 2001 From: Helmut Schaa Date: Mon, 9 Mar 2009 15:47:08 +0100 Subject: [PATCH] mac80211: handle failed scan requests in STA mode If cfg80211 requests a scan it awaits either a return code != 0 from the scan function or the cfg80211_scan_done to be called. In case of a STA mac80211's scan function ever returns 0 and queues the scan request. If ieee80211_sta_work is executed and ieee80211_start_scan fails for some reason cfg80211_scan_done will never be called but cfg80211 still thinks the scan was triggered successfully and will refuse any future scan requests due to drv->scan_req not being cleaned up. If a scan is triggered from within the MLME a similar problem appears. If ieee80211_start_scan returns an error, local->scan_req will not be reset and mac80211 will refuse any future scan requests. Hence, in both cases call ieee80211_scan_failed (which notifies cfg80211 and resets local->scan_req) if ieee80211_start_scan returns an error. Signed-off-by: Helmut Schaa Signed-off-by: John W. Linville --- net/mac80211/ieee80211_i.h | 1 + net/mac80211/mlme.c | 14 ++++++++++++-- net/mac80211/scan.c | 12 ++++++++++++ 3 files changed, 25 insertions(+), 2 deletions(-) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index ecbc8e0cb3e7..fbb91f1aebb2 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -972,6 +972,7 @@ int ieee80211_sta_set_extra_ie(struct ieee80211_sub_if_data *sdata, char *ie, size_t len); void ieee80211_mlme_notify_scan_completed(struct ieee80211_local *local); +void ieee80211_scan_failed(struct ieee80211_local *local); int ieee80211_start_scan(struct ieee80211_sub_if_data *scan_sdata, struct cfg80211_scan_request *req); struct ieee80211_bss * diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index eeb6da8505c6..841b8450b3de 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -1720,7 +1720,10 @@ static int ieee80211_sta_config_auth(struct ieee80211_sub_if_data *sdata) local->int_scan_req.ssids[0].ssid_len = 0; else local->int_scan_req.ssids[0].ssid_len = ifmgd->ssid_len; - ieee80211_start_scan(sdata, &local->int_scan_req); + + if (ieee80211_start_scan(sdata, &local->int_scan_req)) + ieee80211_scan_failed(local); + ifmgd->state = IEEE80211_STA_MLME_AUTHENTICATE; set_bit(IEEE80211_STA_REQ_AUTH, &ifmgd->request); } else { @@ -1757,7 +1760,14 @@ static void ieee80211_sta_work(struct work_struct *work) ifmgd->state != IEEE80211_STA_MLME_AUTHENTICATE && ifmgd->state != IEEE80211_STA_MLME_ASSOCIATE && test_and_clear_bit(IEEE80211_STA_REQ_SCAN, &ifmgd->request)) { - ieee80211_start_scan(sdata, local->scan_req); + /* + * The call to ieee80211_start_scan can fail but ieee80211_request_scan + * (which queued ieee80211_sta_work) did not return an error. Thus, call + * ieee80211_scan_failed here if ieee80211_start_scan fails in order to + * notify the scan requester. + */ + if (ieee80211_start_scan(sdata, local->scan_req)) + ieee80211_scan_failed(local); return; } diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index 0e81e1633a66..5030a3c87509 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -202,6 +202,18 @@ ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb, return RX_QUEUED; } +void ieee80211_scan_failed(struct ieee80211_local *local) +{ + if (WARN_ON(!local->scan_req)) + return; + + /* notify cfg80211 about the failed scan */ + if (local->scan_req != &local->int_scan_req) + cfg80211_scan_done(local->scan_req, true); + + local->scan_req = NULL; +} + void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) { struct ieee80211_local *local = hw_to_local(hw);