diff options
Diffstat (limited to 'net/mac80211/scan.c')
-rw-r--r-- | net/mac80211/scan.c | 304 |
1 files changed, 221 insertions, 83 deletions
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index 7482065..4573100 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -18,7 +18,6 @@ #include <linux/if_arp.h> #include <linux/rtnetlink.h> #include <net/mac80211.h> -#include <net/iw_handler.h> #include "ieee80211_i.h" #include "driver-ops.h" @@ -265,7 +264,7 @@ void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) mutex_lock(&local->scan_mtx); - if (WARN_ON(!local->hw_scanning && !local->sw_scanning)) { + if (WARN_ON(!local->scanning)) { mutex_unlock(&local->scan_mtx); return; } @@ -275,16 +274,15 @@ void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) return; } - if (local->hw_scanning) + if (test_bit(SCAN_HW_SCANNING, &local->scanning)) ieee80211_restore_scan_ies(local); if (local->scan_req != &local->int_scan_req) cfg80211_scan_done(local->scan_req, aborted); local->scan_req = NULL; - was_hw_scan = local->hw_scanning; - local->hw_scanning = false; - local->sw_scanning = false; + was_hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); + local->scanning = 0; local->scan_channel = NULL; /* we only have to protect scan_req and hw/sw scan */ @@ -366,17 +364,16 @@ static int ieee80211_start_sw_scan(struct ieee80211_local *local) ieee80211_bss_info_change_notify( sdata, BSS_CHANGED_BEACON_ENABLED); - if (sdata->vif.type == NL80211_IFTYPE_STATION) { - if (sdata->u.mgd.associated) { - netif_tx_stop_all_queues(sdata->dev); - ieee80211_scan_ps_enable(sdata); - } - } else + /* + * only handle non-STA interfaces here, STA interfaces + * are handled in the scan state machine + */ + if (sdata->vif.type != NL80211_IFTYPE_STATION) netif_tx_stop_all_queues(sdata->dev); } mutex_unlock(&local->iflist_mtx); - local->scan_state = SCAN_SET_CHANNEL; + local->next_scan_state = SCAN_DECISION; local->scan_channel_idx = 0; spin_lock_bh(&local->filter_lock); @@ -434,9 +431,9 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, } if (local->ops->hw_scan) - local->hw_scanning = true; + __set_bit(SCAN_HW_SCANNING, &local->scanning); else - local->sw_scanning = true; + __set_bit(SCAN_SW_SCANNING, &local->scanning); /* * Kicking off the scan need not be protected, * only the scan variable stuff, since now @@ -459,11 +456,9 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, mutex_lock(&local->scan_mtx); if (rc) { - if (local->ops->hw_scan) { - local->hw_scanning = false; + if (local->ops->hw_scan) ieee80211_restore_scan_ies(local); - } else - local->sw_scanning = false; + local->scanning = 0; ieee80211_recalc_idle(local); @@ -474,13 +469,195 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, return rc; } +static int ieee80211_scan_state_decision(struct ieee80211_local *local, + unsigned long *next_delay) +{ + bool associated = false; + struct ieee80211_sub_if_data *sdata; + + /* if no more bands/channels left, complete scan and advance to the idle state */ + if (local->scan_channel_idx >= local->scan_req->n_channels) { + ieee80211_scan_completed(&local->hw, false); + return 1; + } + + /* check if at least one STA interface is associated */ + mutex_lock(&local->iflist_mtx); + list_for_each_entry(sdata, &local->interfaces, list) { + if (!netif_running(sdata->dev)) + continue; + + if (sdata->vif.type == NL80211_IFTYPE_STATION) { + if (sdata->u.mgd.associated) { + associated = true; + break; + } + } + } + mutex_unlock(&local->iflist_mtx); + + if (local->scan_channel) { + /* + * we're currently scanning a different channel, let's + * switch back to the operating channel now if at least + * one interface is associated. Otherwise just scan the + * next channel + */ + if (associated) + local->next_scan_state = SCAN_ENTER_OPER_CHANNEL; + else + local->next_scan_state = SCAN_SET_CHANNEL; + } else { + /* + * we're on the operating channel currently, let's + * leave that channel now to scan another one + */ + local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL; + } + + *next_delay = 0; + return 0; +} + +static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local, + unsigned long *next_delay) +{ + struct ieee80211_sub_if_data *sdata; + + /* + * notify the AP about us leaving the channel and stop all STA interfaces + */ + mutex_lock(&local->iflist_mtx); + list_for_each_entry(sdata, &local->interfaces, list) { + if (!netif_running(sdata->dev)) + continue; + + if (sdata->vif.type == NL80211_IFTYPE_STATION) { + netif_tx_stop_all_queues(sdata->dev); + if (sdata->u.mgd.associated) + ieee80211_scan_ps_enable(sdata); + } + } + mutex_unlock(&local->iflist_mtx); + + __set_bit(SCAN_OFF_CHANNEL, &local->scanning); + + /* advance to the next channel to be scanned */ + *next_delay = HZ / 10; + local->next_scan_state = SCAN_SET_CHANNEL; +} + +static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local, + unsigned long *next_delay) +{ + struct ieee80211_sub_if_data *sdata = local->scan_sdata; + + /* switch back to the operating channel */ + local->scan_channel = NULL; + ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); + + /* + * notify the AP about us being back and restart all STA interfaces + */ + mutex_lock(&local->iflist_mtx); + list_for_each_entry(sdata, &local->interfaces, list) { + if (!netif_running(sdata->dev)) + continue; + + /* Tell AP we're back */ + if (sdata->vif.type == NL80211_IFTYPE_STATION) { + if (sdata->u.mgd.associated) + ieee80211_scan_ps_disable(sdata); + netif_tx_wake_all_queues(sdata->dev); + } + } + mutex_unlock(&local->iflist_mtx); + + __clear_bit(SCAN_OFF_CHANNEL, &local->scanning); + + *next_delay = HZ / 5; + local->next_scan_state = SCAN_DECISION; +} + +static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, + unsigned long *next_delay) +{ + int skip; + struct ieee80211_channel *chan; + struct ieee80211_sub_if_data *sdata = local->scan_sdata; + + skip = 0; + chan = local->scan_req->channels[local->scan_channel_idx]; + + if (chan->flags & IEEE80211_CHAN_DISABLED || + (sdata->vif.type == NL80211_IFTYPE_ADHOC && + chan->flags & IEEE80211_CHAN_NO_IBSS)) + skip = 1; + + if (!skip) { + local->scan_channel = chan; + if (ieee80211_hw_config(local, + IEEE80211_CONF_CHANGE_CHANNEL)) + skip = 1; + } + + /* advance state machine to next channel/band */ + local->scan_channel_idx++; + + if (skip) { + /* if we skip this channel return to the decision state */ + local->next_scan_state = SCAN_DECISION; + return; + } + + /* + * Probe delay is used to update the NAV, cf. 11.1.3.2.2 + * (which unfortunately doesn't say _why_ step a) is done, + * but it waits for the probe delay or until a frame is + * received - and the received frame would update the NAV). + * For now, we do not support waiting until a frame is + * received. + * + * In any case, it is not necessary for a passive scan. + */ + if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || + !local->scan_req->n_ssids) { + *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; + local->next_scan_state = SCAN_DECISION; + return; + } + + /* active scan, send probes */ + *next_delay = IEEE80211_PROBE_DELAY; + local->next_scan_state = SCAN_SEND_PROBE; +} + +static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, + unsigned long *next_delay) +{ + int i; + struct ieee80211_sub_if_data *sdata = local->scan_sdata; + + for (i = 0; i < local->scan_req->n_ssids; i++) + ieee80211_send_probe_req( + sdata, NULL, + local->scan_req->ssids[i].ssid, + local->scan_req->ssids[i].ssid_len, + local->scan_req->ie, local->scan_req->ie_len); + + /* + * After sending probe requests, wait for probe responses + * on the channel. + */ + *next_delay = IEEE80211_CHANNEL_TIME; + local->next_scan_state = SCAN_DECISION; +} + void ieee80211_scan_work(struct work_struct *work) { struct ieee80211_local *local = container_of(work, struct ieee80211_local, scan_work.work); struct ieee80211_sub_if_data *sdata = local->scan_sdata; - struct ieee80211_channel *chan; - int skip, i; unsigned long next_delay = 0; mutex_lock(&local->scan_mtx); @@ -489,7 +666,7 @@ void ieee80211_scan_work(struct work_struct *work) return; } - if (local->scan_req && !(local->sw_scanning || local->hw_scanning)) { + if (local->scan_req && !local->scanning) { struct cfg80211_scan_request *req = local->scan_req; int rc; @@ -513,69 +690,30 @@ void ieee80211_scan_work(struct work_struct *work) return; } - switch (local->scan_state) { - case SCAN_SET_CHANNEL: - /* if no more bands/channels left, complete scan */ - if (local->scan_channel_idx >= local->scan_req->n_channels) { - ieee80211_scan_completed(&local->hw, false); - return; - } - skip = 0; - chan = local->scan_req->channels[local->scan_channel_idx]; - - if (chan->flags & IEEE80211_CHAN_DISABLED || - (sdata->vif.type == NL80211_IFTYPE_ADHOC && - chan->flags & IEEE80211_CHAN_NO_IBSS)) - skip = 1; - - if (!skip) { - local->scan_channel = chan; - if (ieee80211_hw_config(local, - IEEE80211_CONF_CHANGE_CHANNEL)) - skip = 1; - } - - /* advance state machine to next channel/band */ - local->scan_channel_idx++; - - if (skip) + /* + * as long as no delay is required advance immediately + * without scheduling a new work + */ + do { + switch (local->next_scan_state) { + case SCAN_DECISION: + if (ieee80211_scan_state_decision(local, &next_delay)) + return; break; - - /* - * Probe delay is used to update the NAV, cf. 11.1.3.2.2 - * (which unfortunately doesn't say _why_ step a) is done, - * but it waits for the probe delay or until a frame is - * received - and the received frame would update the NAV). - * For now, we do not support waiting until a frame is - * received. - * - * In any case, it is not necessary for a passive scan. - */ - if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || - !local->scan_req->n_ssids) { - next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; + case SCAN_SET_CHANNEL: + ieee80211_scan_state_set_channel(local, &next_delay); + break; + case SCAN_SEND_PROBE: + ieee80211_scan_state_send_probe(local, &next_delay); + break; + case SCAN_LEAVE_OPER_CHANNEL: + ieee80211_scan_state_leave_oper_channel(local, &next_delay); + break; + case SCAN_ENTER_OPER_CHANNEL: + ieee80211_scan_state_enter_oper_channel(local, &next_delay); break; } - - next_delay = IEEE80211_PROBE_DELAY; - local->scan_state = SCAN_SEND_PROBE; - break; - case SCAN_SEND_PROBE: - for (i = 0; i < local->scan_req->n_ssids; i++) - ieee80211_send_probe_req( - sdata, NULL, - local->scan_req->ssids[i].ssid, - local->scan_req->ssids[i].ssid_len, - local->scan_req->ie, local->scan_req->ie_len); - - /* - * After sending probe requests, wait for probe responses - * on the channel. - */ - next_delay = IEEE80211_CHANNEL_TIME; - local->scan_state = SCAN_SET_CHANNEL; - break; - } + } while (next_delay == 0); queue_delayed_work(local->hw.workqueue, &local->scan_work, next_delay); @@ -625,7 +763,7 @@ void ieee80211_scan_cancel(struct ieee80211_local *local) * queued -- mostly at suspend under RTNL. */ mutex_lock(&local->scan_mtx); - swscan = local->sw_scanning; + swscan = test_bit(SCAN_SW_SCANNING, &local->scanning); mutex_unlock(&local->scan_mtx); if (swscan) |