diff options
| -rw-r--r-- | net/mac80211/scan.c | 13 | ||||
| -rw-r--r-- | net/mac80211/tx.c | 14 |
2 files changed, 26 insertions, 1 deletions
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index 5030a3c87509..46f35dc6accb 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -409,6 +409,19 @@ int ieee80211_start_scan(struct ieee80211_sub_if_data *scan_sdata, return 0; } + /* + * Hardware/driver doesn't support hw_scan, so use software + * scanning instead. First send a nullfunc frame with power save + * bit on so that AP will buffer the frames for us while we are not + * listening, then send probe requests to each channel and wait for + * the responses. After all channels are scanned, tune back to the + * original channel and send a nullfunc frame with power save bit + * off to trigger the AP to send us all the buffered frames. + * + * Note that while local->sw_scanning is true everything else but + * nullfunc frames and probe requests will be dropped in + * ieee80211_tx_h_check_assoc(). + */ local->sw_scanning = true; if (local->ops->sw_scan_start) local->ops->sw_scan_start(local_to_hw(local)); diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 038460b0a48a..f3f240c69018 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -193,7 +193,19 @@ ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx) return TX_CONTINUE; if (unlikely(tx->local->sw_scanning) && - !ieee80211_is_probe_req(hdr->frame_control)) + !ieee80211_is_probe_req(hdr->frame_control) && + !ieee80211_is_nullfunc(hdr->frame_control)) + /* + * When software scanning only nullfunc frames (to notify + * the sleep state to the AP) and probe requests (for the + * active scan) are allowed, all other frames should not be + * sent and we should not get here, but if we do + * nonetheless, drop them to avoid sending them + * off-channel. See the link below and + * ieee80211_start_scan() for more. + * + * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089 + */ return TX_DROP; if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT) |