/*
- * BSS client mode implementation
+ * Scanning implementation
+ *
* Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
* Copyright 2004, Instant802 Networks, Inc.
* Copyright 2005, Devicescape Software, Inc.
* published by the Free Software Foundation.
*/
-#include <linux/wireless.h>
#include <linux/if_arp.h>
+#include <linux/rtnetlink.h>
+#include <linux/pm_qos_params.h>
+#include <net/sch_generic.h>
+#include <linux/slab.h>
#include <net/mac80211.h>
-#include <net/iw_handler.h>
#include "ieee80211_i.h"
+#include "driver-ops.h"
+#include "mesh.h"
#define IEEE80211_PROBE_DELAY (HZ / 33)
#define IEEE80211_CHANNEL_TIME (HZ / 33)
-#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 5)
+#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 8)
+struct ieee80211_bss *
+ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq,
+ u8 *ssid, u8 ssid_len)
+{
+ struct cfg80211_bss *cbss;
+
+ cbss = cfg80211_get_bss(local->hw.wiphy,
+ ieee80211_get_channel(local->hw.wiphy, freq),
+ bssid, ssid, ssid_len, 0, 0);
+ if (!cbss)
+ return NULL;
+ return (void *)cbss->priv;
+}
-static void ieee80211_send_nullfunc(struct ieee80211_local *local,
- struct ieee80211_sub_if_data *sdata,
- int powersave)
+static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss)
{
- struct sk_buff *skb;
- struct ieee80211_hdr *nullfunc;
- __le16 fc;
+ struct ieee80211_bss *bss = (void *)cbss->priv;
- skb = dev_alloc_skb(local->hw.extra_tx_headroom + 24);
- if (!skb) {
- printk(KERN_DEBUG "%s: failed to allocate buffer for nullfunc "
- "frame\n", sdata->dev->name);
+ kfree(bss_mesh_id(bss));
+ kfree(bss_mesh_cfg(bss));
+}
+
+void ieee80211_rx_bss_put(struct ieee80211_local *local,
+ struct ieee80211_bss *bss)
+{
+ if (!bss)
return;
- }
- skb_reserve(skb, local->hw.extra_tx_headroom);
-
- nullfunc = (struct ieee80211_hdr *) skb_put(skb, 24);
- memset(nullfunc, 0, 24);
- fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_NULLFUNC |
- IEEE80211_FCTL_TODS);
- if (powersave)
- fc |= cpu_to_le16(IEEE80211_FCTL_PM);
- nullfunc->frame_control = fc;
- memcpy(nullfunc->addr1, sdata->u.sta.bssid, ETH_ALEN);
- memcpy(nullfunc->addr2, sdata->dev->dev_addr, ETH_ALEN);
- memcpy(nullfunc->addr3, sdata->u.sta.bssid, ETH_ALEN);
-
- ieee80211_sta_tx(sdata, skb, 0);
+ cfg80211_put_bss(container_of((void *)bss, struct cfg80211_bss, priv));
}
-static void ieee80211_restart_sta_timer(struct ieee80211_sub_if_data *sdata)
+static bool is_uapsd_supported(struct ieee802_11_elems *elems)
{
- if (sdata->vif.type == IEEE80211_IF_TYPE_STA ||
- ieee80211_vif_is_mesh(&sdata->vif))
- ieee80211_sta_timer((unsigned long)sdata);
+ u8 qos_info;
+
+ if (elems->wmm_info && elems->wmm_info_len == 7
+ && elems->wmm_info[5] == 1)
+ qos_info = elems->wmm_info[6];
+ else if (elems->wmm_param && elems->wmm_param_len == 24
+ && elems->wmm_param[5] == 1)
+ qos_info = elems->wmm_param[6];
+ else
+ /* no valid wmm information or parameter element found */
+ return false;
+
+ return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
}
-void ieee80211_scan_completed(struct ieee80211_hw *hw)
+struct ieee80211_bss *
+ieee80211_bss_info_update(struct ieee80211_local *local,
+ struct ieee80211_rx_status *rx_status,
+ struct ieee80211_mgmt *mgmt,
+ size_t len,
+ struct ieee802_11_elems *elems,
+ struct ieee80211_channel *channel,
+ bool beacon)
{
- struct ieee80211_local *local = hw_to_local(hw);
- struct ieee80211_sub_if_data *sdata;
- union iwreq_data wrqu;
-
- local->last_scan_completed = jiffies;
- memset(&wrqu, 0, sizeof(wrqu));
- wireless_send_event(local->scan_sdata->dev, SIOCGIWSCAN, &wrqu, NULL);
-
- if (local->sta_hw_scanning) {
- local->sta_hw_scanning = 0;
- if (ieee80211_hw_config(local))
- printk(KERN_DEBUG "%s: failed to restore operational "
- "channel after scan\n", wiphy_name(local->hw.wiphy));
- /* Restart STA timer for HW scan case */
- rcu_read_lock();
- list_for_each_entry_rcu(sdata, &local->interfaces, list)
- ieee80211_restart_sta_timer(sdata);
- rcu_read_unlock();
+ struct cfg80211_bss *cbss;
+ struct ieee80211_bss *bss;
+ int clen, srlen;
+ s32 signal = 0;
- goto done;
+ if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
+ signal = rx_status->signal * 100;
+ else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
+ signal = (rx_status->signal * 100) / local->hw.max_signal;
+
+ cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel,
+ mgmt, len, signal, GFP_ATOMIC);
+
+ if (!cbss)
+ return NULL;
+
+ cbss->free_priv = ieee80211_rx_bss_free;
+ bss = (void *)cbss->priv;
+
+ /* save the ERP value so that it is available at association time */
+ if (elems->erp_info && elems->erp_info_len >= 1) {
+ bss->erp_value = elems->erp_info[0];
+ bss->has_erp_value = 1;
}
- local->sta_sw_scanning = 0;
- if (ieee80211_hw_config(local))
- printk(KERN_DEBUG "%s: failed to restore operational "
- "channel after scan\n", wiphy_name(local->hw.wiphy));
-
-
- netif_tx_lock_bh(local->mdev);
- netif_addr_lock(local->mdev);
- local->filter_flags &= ~FIF_BCN_PRBRESP_PROMISC;
- local->ops->configure_filter(local_to_hw(local),
- FIF_BCN_PRBRESP_PROMISC,
- &local->filter_flags,
- local->mdev->mc_count,
- local->mdev->mc_list);
-
- netif_addr_unlock(local->mdev);
- netif_tx_unlock_bh(local->mdev);
-
- rcu_read_lock();
- list_for_each_entry_rcu(sdata, &local->interfaces, list) {
- /* Tell AP we're back */
- if (sdata->vif.type == IEEE80211_IF_TYPE_STA) {
- if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
- ieee80211_send_nullfunc(local, sdata, 0);
- netif_tx_wake_all_queues(sdata->dev);
- }
- } else
- netif_tx_wake_all_queues(sdata->dev);
+ if (elems->tim) {
+ struct ieee80211_tim_ie *tim_ie =
+ (struct ieee80211_tim_ie *)elems->tim;
+ bss->dtim_period = tim_ie->dtim_period;
+ }
- ieee80211_restart_sta_timer(sdata);
+ /* replace old supported rates if we get new values */
+ srlen = 0;
+ if (elems->supp_rates) {
+ clen = IEEE80211_MAX_SUPP_RATES;
+ if (clen > elems->supp_rates_len)
+ clen = elems->supp_rates_len;
+ memcpy(bss->supp_rates, elems->supp_rates, clen);
+ srlen += clen;
+ }
+ if (elems->ext_supp_rates) {
+ clen = IEEE80211_MAX_SUPP_RATES - srlen;
+ if (clen > elems->ext_supp_rates_len)
+ clen = elems->ext_supp_rates_len;
+ memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, clen);
+ srlen += clen;
}
- rcu_read_unlock();
+ if (srlen)
+ bss->supp_rates_len = srlen;
- done:
- ieee80211_mlme_notify_scan_completed(local);
-}
-EXPORT_SYMBOL(ieee80211_scan_completed);
+ bss->wmm_used = elems->wmm_param || elems->wmm_info;
+ bss->uapsd_supported = is_uapsd_supported(elems);
+ if (!beacon)
+ bss->last_probe_resp = jiffies;
-void ieee80211_sta_scan_work(struct work_struct *work)
+ return bss;
+}
+
+ieee80211_rx_result
+ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
{
- struct ieee80211_local *local =
- container_of(work, struct ieee80211_local, scan_work.work);
- struct ieee80211_sub_if_data *sdata = local->scan_sdata;
- struct ieee80211_supported_band *sband;
- struct ieee80211_channel *chan;
- int skip;
- unsigned long next_delay = 0;
+ struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
+ struct ieee80211_mgmt *mgmt;
+ struct ieee80211_bss *bss;
+ u8 *elements;
+ struct ieee80211_channel *channel;
+ size_t baselen;
+ int freq;
+ __le16 fc;
+ bool presp, beacon = false;
+ struct ieee802_11_elems elems;
- if (!local->sta_sw_scanning)
- return;
+ if (skb->len < 2)
+ return RX_DROP_UNUSABLE;
- switch (local->scan_state) {
- case SCAN_SET_CHANNEL:
- /*
- * Get current scan band. scan_band may be IEEE80211_NUM_BANDS
- * after we successfully scanned the last channel of the last
- * band (and the last band is supported by the hw)
- */
- if (local->scan_band < IEEE80211_NUM_BANDS)
- sband = local->hw.wiphy->bands[local->scan_band];
- else
- sband = NULL;
+ mgmt = (struct ieee80211_mgmt *) skb->data;
+ fc = mgmt->frame_control;
- /*
- * If we are at an unsupported band and have more bands
- * left to scan, advance to the next supported one.
- */
- while (!sband && local->scan_band < IEEE80211_NUM_BANDS - 1) {
- local->scan_band++;
- sband = local->hw.wiphy->bands[local->scan_band];
- local->scan_channel_idx = 0;
- }
+ if (ieee80211_is_ctl(fc))
+ return RX_CONTINUE;
- /* if no more bands/channels left, complete scan */
- if (!sband || local->scan_channel_idx >= sband->n_channels) {
- ieee80211_scan_completed(local_to_hw(local));
- return;
- }
- skip = 0;
- chan = &sband->channels[local->scan_channel_idx];
-
- if (chan->flags & IEEE80211_CHAN_DISABLED ||
- (sdata->vif.type == IEEE80211_IF_TYPE_IBSS &&
- chan->flags & IEEE80211_CHAN_NO_IBSS))
- skip = 1;
-
- if (!skip) {
- local->scan_channel = chan;
- if (ieee80211_hw_config(local)) {
- printk(KERN_DEBUG "%s: failed to set freq to "
- "%d MHz for scan\n", wiphy_name(local->hw.wiphy),
- chan->center_freq);
- skip = 1;
- }
- }
+ if (skb->len < 24)
+ return RX_DROP_MONITOR;
- /* advance state machine to next channel/band */
- local->scan_channel_idx++;
- if (local->scan_channel_idx >= sband->n_channels) {
- /*
- * scan_band may end up == IEEE80211_NUM_BANDS, but
- * we'll catch that case above and complete the scan
- * if that is the case.
- */
- local->scan_band++;
- local->scan_channel_idx = 0;
- }
+ presp = ieee80211_is_probe_resp(fc);
+ if (presp) {
+ /* ignore ProbeResp to foreign address */
+ if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
+ return RX_DROP_MONITOR;
- if (skip)
- break;
+ presp = true;
+ elements = mgmt->u.probe_resp.variable;
+ baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
+ } else {
+ beacon = ieee80211_is_beacon(fc);
+ baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
+ elements = mgmt->u.beacon.variable;
+ }
- next_delay = IEEE80211_PROBE_DELAY +
- usecs_to_jiffies(local->hw.channel_change_time);
- local->scan_state = SCAN_SEND_PROBE;
- break;
- case SCAN_SEND_PROBE:
- next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
- local->scan_state = SCAN_SET_CHANNEL;
+ if (!presp && !beacon)
+ return RX_CONTINUE;
- if (local->scan_channel->flags & IEEE80211_CHAN_PASSIVE_SCAN)
- break;
- ieee80211_send_probe_req(sdata, NULL, local->scan_ssid,
- local->scan_ssid_len);
- next_delay = IEEE80211_CHANNEL_TIME;
- break;
- }
+ if (baselen > skb->len)
+ return RX_DROP_MONITOR;
- if (local->sta_sw_scanning)
- queue_delayed_work(local->hw.workqueue, &local->scan_work,
- next_delay);
+ ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
+
+ if (elems.ds_params && elems.ds_params_len == 1)
+ freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
+ else
+ freq = rx_status->freq;
+
+ channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq);
+
+ if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
+ return RX_DROP_MONITOR;
+
+ bss = ieee80211_bss_info_update(sdata->local, rx_status,
+ mgmt, skb->len, &elems,
+ channel, beacon);
+ if (bss)
+ ieee80211_rx_bss_put(sdata->local, bss);
+
+ dev_kfree_skb(skb);
+ return RX_QUEUED;
}
+/* return false if no more work */
+static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
+{
+ struct cfg80211_scan_request *req = local->scan_req;
+ enum ieee80211_band band;
+ int i, ielen, n_chans;
+
+ do {
+ if (local->hw_scan_band == IEEE80211_NUM_BANDS)
+ return false;
+
+ band = local->hw_scan_band;
+ n_chans = 0;
+ for (i = 0; i < req->n_channels; i++) {
+ if (req->channels[i]->band == band) {
+ local->hw_scan_req->channels[n_chans] =
+ req->channels[i];
+ n_chans++;
+ }
+ }
+
+ local->hw_scan_band++;
+ } while (!n_chans);
+
+ local->hw_scan_req->n_channels = n_chans;
+
+ ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie,
+ req->ie, req->ie_len, band);
+ local->hw_scan_req->ie_len = ielen;
+
+ return true;
+}
-int ieee80211_sta_start_scan(struct ieee80211_sub_if_data *scan_sdata,
- u8 *ssid, size_t ssid_len)
+void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
{
- struct ieee80211_local *local = scan_sdata->local;
- struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_local *local = hw_to_local(hw);
+ bool was_hw_scan;
+
+ trace_api_scan_completed(local, aborted);
+
+ mutex_lock(&local->scan_mtx);
- if (ssid_len > IEEE80211_MAX_SSID_LEN)
- return -EINVAL;
-
- /* MLME-SCAN.request (page 118) page 144 (11.1.3.1)
- * BSSType: INFRASTRUCTURE, INDEPENDENT, ANY_BSS
- * BSSID: MACAddress
- * SSID
- * ScanType: ACTIVE, PASSIVE
- * ProbeDelay: delay (in microseconds) to be used prior to transmitting
- * a Probe frame during active scanning
- * ChannelList
- * MinChannelTime (>= ProbeDelay), in TU
- * MaxChannelTime: (>= MinChannelTime), in TU
+ /*
+ * It's ok to abort a not-yet-running scan (that
+ * we have one at all will be verified by checking
+ * local->scan_req next), but not to complete it
+ * successfully.
*/
+ if (WARN_ON(!local->scanning && !aborted))
+ aborted = true;
+
+ if (WARN_ON(!local->scan_req)) {
+ mutex_unlock(&local->scan_mtx);
+ return;
+ }
+
+ was_hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
+ if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) {
+ ieee80211_queue_delayed_work(&local->hw,
+ &local->scan_work, 0);
+ mutex_unlock(&local->scan_mtx);
+ return;
+ }
+
+ kfree(local->hw_scan_req);
+ local->hw_scan_req = NULL;
+
+ if (local->scan_req != local->int_scan_req)
+ cfg80211_scan_done(local->scan_req, aborted);
+ local->scan_req = NULL;
+ local->scan_sdata = NULL;
+
+ local->scanning = 0;
+ local->scan_channel = NULL;
- /* MLME-SCAN.confirm
- * BSSDescriptionSet
- * ResultCode: SUCCESS, INVALID_PARAMETERS
+ /* we only have to protect scan_req and hw/sw scan */
+ mutex_unlock(&local->scan_mtx);
+
+ ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
+ if (was_hw_scan)
+ goto done;
+
+ ieee80211_configure_filter(local);
+
+ drv_sw_scan_complete(local);
+
+ ieee80211_offchannel_return(local, true);
+
+ done:
+ ieee80211_recalc_idle(local);
+ ieee80211_mlme_notify_scan_completed(local);
+ ieee80211_ibss_notify_scan_completed(local);
+ ieee80211_mesh_notify_scan_completed(local);
+ ieee80211_queue_work(&local->hw, &local->work_work);
+}
+EXPORT_SYMBOL(ieee80211_scan_completed);
+
+static int ieee80211_start_sw_scan(struct ieee80211_local *local)
+{
+ /*
+ * 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().
*/
+ drv_sw_scan_start(local);
+
+ ieee80211_offchannel_stop_beaconing(local);
- if (local->sta_sw_scanning || local->sta_hw_scanning) {
- if (local->scan_sdata == scan_sdata)
- return 0;
+ local->leave_oper_channel_time = 0;
+ local->next_scan_state = SCAN_DECISION;
+ local->scan_channel_idx = 0;
+
+ drv_flush(local, false);
+
+ ieee80211_configure_filter(local);
+
+ ieee80211_queue_delayed_work(&local->hw,
+ &local->scan_work,
+ IEEE80211_CHANNEL_TIME);
+
+ return 0;
+}
+
+
+static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
+ struct cfg80211_scan_request *req)
+{
+ struct ieee80211_local *local = sdata->local;
+ int rc;
+
+ if (local->scan_req)
return -EBUSY;
+
+ if (!list_empty(&local->work_list)) {
+ /* wait for the work to finish/time out */
+ local->scan_req = req;
+ local->scan_sdata = sdata;
+ return 0;
}
if (local->ops->hw_scan) {
- int rc = local->ops->hw_scan(local_to_hw(local),
- ssid, ssid_len);
- if (!rc) {
- local->sta_hw_scanning = 1;
- local->scan_sdata = scan_sdata;
- }
- return rc;
- }
+ u8 *ies;
- local->sta_sw_scanning = 1;
+ local->hw_scan_req = kmalloc(
+ sizeof(*local->hw_scan_req) +
+ req->n_channels * sizeof(req->channels[0]) +
+ 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len +
+ req->ie_len, GFP_KERNEL);
+ if (!local->hw_scan_req)
+ return -ENOMEM;
- rcu_read_lock();
- list_for_each_entry_rcu(sdata, &local->interfaces, list) {
- if (sdata->vif.type == IEEE80211_IF_TYPE_STA) {
- if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
- netif_tx_stop_all_queues(sdata->dev);
- ieee80211_send_nullfunc(local, sdata, 1);
- }
- } else
- netif_tx_stop_all_queues(sdata->dev);
+ local->hw_scan_req->ssids = req->ssids;
+ local->hw_scan_req->n_ssids = req->n_ssids;
+ ies = (u8 *)local->hw_scan_req +
+ sizeof(*local->hw_scan_req) +
+ req->n_channels * sizeof(req->channels[0]);
+ local->hw_scan_req->ie = ies;
+
+ local->hw_scan_band = 0;
+
+ /*
+ * After allocating local->hw_scan_req, we must
+ * go through until ieee80211_prep_hw_scan(), so
+ * anything that might be changed here and leave
+ * this function early must not go after this
+ * allocation.
+ */
}
- rcu_read_unlock();
- if (ssid) {
- local->scan_ssid_len = ssid_len;
- memcpy(local->scan_ssid, ssid, ssid_len);
+ local->scan_req = req;
+ local->scan_sdata = sdata;
+
+ if (local->ops->hw_scan)
+ __set_bit(SCAN_HW_SCANNING, &local->scanning);
+ else
+ __set_bit(SCAN_SW_SCANNING, &local->scanning);
+
+ /*
+ * Kicking off the scan need not be protected,
+ * only the scan variable stuff, since now
+ * local->scan_req is assigned and other callers
+ * will abort their scan attempts.
+ *
+ * This avoids too many locking dependencies
+ * so that the scan completed calls have more
+ * locking freedom.
+ */
+
+ ieee80211_recalc_idle(local);
+ mutex_unlock(&local->scan_mtx);
+
+ if (local->ops->hw_scan) {
+ WARN_ON(!ieee80211_prep_hw_scan(local));
+ rc = drv_hw_scan(local, sdata, local->hw_scan_req);
} else
- local->scan_ssid_len = 0;
- local->scan_state = SCAN_SET_CHANNEL;
- local->scan_channel_idx = 0;
- local->scan_band = IEEE80211_BAND_2GHZ;
- local->scan_sdata = scan_sdata;
-
- netif_addr_lock_bh(local->mdev);
- local->filter_flags |= FIF_BCN_PRBRESP_PROMISC;
- local->ops->configure_filter(local_to_hw(local),
- FIF_BCN_PRBRESP_PROMISC,
- &local->filter_flags,
- local->mdev->mc_count,
- local->mdev->mc_list);
- netif_addr_unlock_bh(local->mdev);
-
- /* TODO: start scan as soon as all nullfunc frames are ACKed */
- queue_delayed_work(local->hw.workqueue, &local->scan_work,
- IEEE80211_CHANNEL_TIME);
+ rc = ieee80211_start_sw_scan(local);
- return 0;
+ mutex_lock(&local->scan_mtx);
+
+ if (rc) {
+ kfree(local->hw_scan_req);
+ local->hw_scan_req = NULL;
+ local->scanning = 0;
+
+ ieee80211_recalc_idle(local);
+
+ local->scan_req = NULL;
+ local->scan_sdata = NULL;
+ }
+
+ return rc;
}
+static unsigned long
+ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
+{
+ /*
+ * TODO: channel switching also consumes quite some time,
+ * add that delay as well to get a better estimation
+ */
+ if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN)
+ return IEEE80211_PASSIVE_CHANNEL_TIME;
+ return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
+}
-int ieee80211_sta_req_scan(struct ieee80211_sub_if_data *sdata, u8 *ssid, size_t ssid_len)
+static int ieee80211_scan_state_decision(struct ieee80211_local *local,
+ unsigned long *next_delay)
{
- struct ieee80211_if_sta *ifsta = &sdata->u.sta;
- struct ieee80211_local *local = sdata->local;
+ bool associated = false;
+ bool tx_empty = true;
+ bool bad_latency;
+ bool listen_int_exceeded;
+ unsigned long min_beacon_int = 0;
+ struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_channel *next_chan;
- if (sdata->vif.type != IEEE80211_IF_TYPE_STA)
- return ieee80211_sta_start_scan(sdata, ssid, ssid_len);
+ /* 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;
+ }
- if (local->sta_sw_scanning || local->sta_hw_scanning) {
- if (local->scan_sdata == sdata)
- return 0;
- return -EBUSY;
+ /*
+ * check if at least one STA interface is associated,
+ * check if at least one STA interface has pending tx frames
+ * and grab the lowest used beacon interval
+ */
+ mutex_lock(&local->iflist_mtx);
+ list_for_each_entry(sdata, &local->interfaces, list) {
+ if (!ieee80211_sdata_running(sdata))
+ continue;
+
+ if (sdata->vif.type == NL80211_IFTYPE_STATION) {
+ if (sdata->u.mgd.associated) {
+ associated = true;
+
+ if (sdata->vif.bss_conf.beacon_int <
+ min_beacon_int || min_beacon_int == 0)
+ min_beacon_int =
+ sdata->vif.bss_conf.beacon_int;
+
+ if (!qdisc_all_tx_empty(sdata->dev)) {
+ tx_empty = false;
+ break;
+ }
+ }
+ }
+ }
+ mutex_unlock(&local->iflist_mtx);
+
+ if (local->scan_channel) {
+ /*
+ * we're currently scanning a different channel, let's
+ * see if we can scan another channel without interfering
+ * with the current traffic situation.
+ *
+ * Since we don't know if the AP has pending frames for us
+ * we can only check for our tx queues and use the current
+ * pm_qos requirements for rx. Hence, if no tx traffic occurs
+ * at all we will scan as many channels in a row as the pm_qos
+ * latency allows us to. Additionally we also check for the
+ * currently negotiated listen interval to prevent losing
+ * frames unnecessarily.
+ *
+ * Otherwise switch back to the operating channel.
+ */
+ next_chan = local->scan_req->channels[local->scan_channel_idx];
+
+ bad_latency = time_after(jiffies +
+ ieee80211_scan_get_channel_time(next_chan),
+ local->leave_oper_channel_time +
+ usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY)));
+
+ listen_int_exceeded = time_after(jiffies +
+ ieee80211_scan_get_channel_time(next_chan),
+ local->leave_oper_channel_time +
+ usecs_to_jiffies(min_beacon_int * 1024) *
+ local->hw.conf.listen_interval);
+
+ if (associated && ( !tx_empty || bad_latency ||
+ listen_int_exceeded))
+ 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;
}
- ifsta->scan_ssid_len = ssid_len;
- if (ssid_len)
- memcpy(ifsta->scan_ssid, ssid, ssid_len);
- set_bit(IEEE80211_STA_REQ_SCAN, &ifsta->request);
- queue_work(local->hw.workqueue, &ifsta->work);
+ *next_delay = 0;
return 0;
}
-
-static void ieee80211_sta_add_scan_ies(struct iw_request_info *info,
- struct ieee80211_sta_bss *bss,
- char **current_ev, char *end_buf)
+static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local,
+ unsigned long *next_delay)
{
- u8 *pos, *end, *next;
- struct iw_event iwe;
+ ieee80211_offchannel_stop_station(local);
- if (bss == NULL || bss->ies == NULL)
- return;
+ __set_bit(SCAN_OFF_CHANNEL, &local->scanning);
+
+ /*
+ * What if the nullfunc frames didn't arrive?
+ */
+ drv_flush(local, false);
+ if (local->ops->flush)
+ *next_delay = 0;
+ else
+ *next_delay = HZ / 10;
+
+ /* remember when we left the operating channel */
+ local->leave_oper_channel_time = jiffies;
+
+ /* advance to the next channel to be scanned */
+ local->next_scan_state = SCAN_SET_CHANNEL;
+}
+
+static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local,
+ unsigned long *next_delay)
+{
+ /* switch back to the operating channel */
+ local->scan_channel = NULL;
+ ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
/*
- * If needed, fragment the IEs buffer (at IE boundaries) into short
- * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
+ * Only re-enable station mode interface now; beaconing will be
+ * re-enabled once the full scan has been completed.
*/
- pos = bss->ies;
- end = pos + bss->ies_len;
+ ieee80211_offchannel_return(local, false);
+
+ __clear_bit(SCAN_OFF_CHANNEL, &local->scanning);
+
+ *next_delay = HZ / 5;
+ local->next_scan_state = SCAN_DECISION;
+}
- while (end - pos > IW_GENERIC_IE_MAX) {
- next = pos + 2 + pos[1];
- while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
- next = next + 2 + next[1];
+static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
+ unsigned long *next_delay)
+{
+ int skip;
+ struct ieee80211_channel *chan;
+
+ skip = 0;
+ chan = local->scan_req->channels[local->scan_channel_idx];
- memset(&iwe, 0, sizeof(iwe));
- iwe.cmd = IWEVGENIE;
- iwe.u.data.length = next - pos;
- *current_ev = iwe_stream_add_point(info, *current_ev,
- end_buf, &iwe, pos);
+ local->scan_channel = chan;
+ if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
+ skip = 1;
- pos = next;
+ /* 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;
}
- if (end > pos) {
- memset(&iwe, 0, sizeof(iwe));
- iwe.cmd = IWEVGENIE;
- iwe.u.data.length = end - pos;
- *current_ev = iwe_stream_add_point(info, *current_ev,
- end_buf, &iwe, pos);
+ /*
+ * 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;
+}
-static char *
-ieee80211_sta_scan_result(struct ieee80211_local *local,
- struct iw_request_info *info,
- struct ieee80211_sta_bss *bss,
- char *current_ev, char *end_buf)
+void ieee80211_scan_work(struct work_struct *work)
{
- struct iw_event iwe;
- char *buf;
-
- if (time_after(jiffies,
- bss->last_update + IEEE80211_SCAN_RESULT_EXPIRE))
- return current_ev;
-
- memset(&iwe, 0, sizeof(iwe));
- iwe.cmd = SIOCGIWAP;
- iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
- memcpy(iwe.u.ap_addr.sa_data, bss->bssid, ETH_ALEN);
- current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
- IW_EV_ADDR_LEN);
-
- memset(&iwe, 0, sizeof(iwe));
- iwe.cmd = SIOCGIWESSID;
- if (bss_mesh_cfg(bss)) {
- iwe.u.data.length = bss_mesh_id_len(bss);
- iwe.u.data.flags = 1;
- current_ev = iwe_stream_add_point(info, current_ev, end_buf,
- &iwe, bss_mesh_id(bss));
- } else {
- iwe.u.data.length = bss->ssid_len;
- iwe.u.data.flags = 1;
- current_ev = iwe_stream_add_point(info, current_ev, end_buf,
- &iwe, bss->ssid);
+ struct ieee80211_local *local =
+ container_of(work, struct ieee80211_local, scan_work.work);
+ struct ieee80211_sub_if_data *sdata = local->scan_sdata;
+ unsigned long next_delay = 0;
+
+ mutex_lock(&local->scan_mtx);
+ if (!sdata || !local->scan_req) {
+ mutex_unlock(&local->scan_mtx);
+ return;
}
- if (bss->capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
- || bss_mesh_cfg(bss)) {
- memset(&iwe, 0, sizeof(iwe));
- iwe.cmd = SIOCGIWMODE;
- if (bss_mesh_cfg(bss))
- iwe.u.mode = IW_MODE_MESH;
- else if (bss->capability & WLAN_CAPABILITY_ESS)
- iwe.u.mode = IW_MODE_MASTER;
- else
- iwe.u.mode = IW_MODE_ADHOC;
- current_ev = iwe_stream_add_event(info, current_ev, end_buf,
- &iwe, IW_EV_UINT_LEN);
+ if (local->hw_scan_req) {
+ int rc = drv_hw_scan(local, sdata, local->hw_scan_req);
+ mutex_unlock(&local->scan_mtx);
+ if (rc)
+ ieee80211_scan_completed(&local->hw, true);
+ return;
}
- memset(&iwe, 0, sizeof(iwe));
- iwe.cmd = SIOCGIWFREQ;
- iwe.u.freq.m = ieee80211_frequency_to_channel(bss->freq);
- iwe.u.freq.e = 0;
- current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
- IW_EV_FREQ_LEN);
-
- memset(&iwe, 0, sizeof(iwe));
- iwe.cmd = SIOCGIWFREQ;
- iwe.u.freq.m = bss->freq;
- iwe.u.freq.e = 6;
- current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
- IW_EV_FREQ_LEN);
- memset(&iwe, 0, sizeof(iwe));
- iwe.cmd = IWEVQUAL;
- iwe.u.qual.qual = bss->qual;
- iwe.u.qual.level = bss->signal;
- iwe.u.qual.noise = bss->noise;
- iwe.u.qual.updated = local->wstats_flags;
- current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
- IW_EV_QUAL_LEN);
-
- memset(&iwe, 0, sizeof(iwe));
- iwe.cmd = SIOCGIWENCODE;
- if (bss->capability & WLAN_CAPABILITY_PRIVACY)
- iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
- else
- iwe.u.data.flags = IW_ENCODE_DISABLED;
- iwe.u.data.length = 0;
- current_ev = iwe_stream_add_point(info, current_ev, end_buf,
- &iwe, "");
-
- ieee80211_sta_add_scan_ies(info, bss, ¤t_ev, end_buf);
-
- if (bss->supp_rates_len > 0) {
- /* display all supported rates in readable format */
- char *p = current_ev + iwe_stream_lcp_len(info);
- int i;
-
- memset(&iwe, 0, sizeof(iwe));
- iwe.cmd = SIOCGIWRATE;
- /* Those two flags are ignored... */
- iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
-
- for (i = 0; i < bss->supp_rates_len; i++) {
- iwe.u.bitrate.value = ((bss->supp_rates[i] &
- 0x7f) * 500000);
- p = iwe_stream_add_value(info, current_ev, p,
- end_buf, &iwe, IW_EV_PARAM_LEN);
- }
- current_ev = p;
+ if (local->scan_req && !local->scanning) {
+ struct cfg80211_scan_request *req = local->scan_req;
+ int rc;
+
+ local->scan_req = NULL;
+ local->scan_sdata = NULL;
+
+ rc = __ieee80211_start_scan(sdata, req);
+ mutex_unlock(&local->scan_mtx);
+
+ if (rc)
+ ieee80211_scan_completed(&local->hw, true);
+ return;
}
- buf = kmalloc(30, GFP_ATOMIC);
- if (buf) {
- memset(&iwe, 0, sizeof(iwe));
- iwe.cmd = IWEVCUSTOM;
- sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->timestamp));
- iwe.u.data.length = strlen(buf);
- current_ev = iwe_stream_add_point(info, current_ev, end_buf,
- &iwe, buf);
- memset(&iwe, 0, sizeof(iwe));
- iwe.cmd = IWEVCUSTOM;
- sprintf(buf, " Last beacon: %dms ago",
- jiffies_to_msecs(jiffies - bss->last_update));
- iwe.u.data.length = strlen(buf);
- current_ev = iwe_stream_add_point(info, current_ev,
- end_buf, &iwe, buf);
- kfree(buf);
+ mutex_unlock(&local->scan_mtx);
+
+ /*
+ * Avoid re-scheduling when the sdata is going away.
+ */
+ if (!ieee80211_sdata_running(sdata)) {
+ ieee80211_scan_completed(&local->hw, true);
+ return;
}
- if (bss_mesh_cfg(bss)) {
- u8 *cfg = bss_mesh_cfg(bss);
- buf = kmalloc(50, GFP_ATOMIC);
- if (buf) {
- memset(&iwe, 0, sizeof(iwe));
- iwe.cmd = IWEVCUSTOM;
- sprintf(buf, "Mesh network (version %d)", cfg[0]);
- iwe.u.data.length = strlen(buf);
- current_ev = iwe_stream_add_point(info, current_ev,
- end_buf,
- &iwe, buf);
- sprintf(buf, "Path Selection Protocol ID: "
- "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
- cfg[4]);
- iwe.u.data.length = strlen(buf);
- current_ev = iwe_stream_add_point(info, current_ev,
- end_buf,
- &iwe, buf);
- sprintf(buf, "Path Selection Metric ID: "
- "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
- cfg[8]);
- iwe.u.data.length = strlen(buf);
- current_ev = iwe_stream_add_point(info, current_ev,
- end_buf,
- &iwe, buf);
- sprintf(buf, "Congestion Control Mode ID: "
- "0x%02X%02X%02X%02X", cfg[9], cfg[10],
- cfg[11], cfg[12]);
- iwe.u.data.length = strlen(buf);
- current_ev = iwe_stream_add_point(info, current_ev,
- end_buf,
- &iwe, buf);
- sprintf(buf, "Channel Precedence: "
- "0x%02X%02X%02X%02X", cfg[13], cfg[14],
- cfg[15], cfg[16]);
- iwe.u.data.length = strlen(buf);
- current_ev = iwe_stream_add_point(info, current_ev,
- end_buf,
- &iwe, buf);
- kfree(buf);
+ /*
+ * 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;
+ 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;
}
- }
+ } while (next_delay == 0);
- return current_ev;
+ ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
}
+int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
+ struct cfg80211_scan_request *req)
+{
+ int res;
+
+ mutex_lock(&sdata->local->scan_mtx);
+ res = __ieee80211_start_scan(sdata, req);
+ mutex_unlock(&sdata->local->scan_mtx);
-int ieee80211_sta_scan_results(struct ieee80211_local *local,
- struct iw_request_info *info,
- char *buf, size_t len)
+ return res;
+}
+
+int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
+ const u8 *ssid, u8 ssid_len,
+ struct ieee80211_channel *chan)
{
- char *current_ev = buf;
- char *end_buf = buf + len;
- struct ieee80211_sta_bss *bss;
-
- spin_lock_bh(&local->sta_bss_lock);
- list_for_each_entry(bss, &local->sta_bss_list, list) {
- if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
- spin_unlock_bh(&local->sta_bss_lock);
- return -E2BIG;
+ struct ieee80211_local *local = sdata->local;
+ int ret = -EBUSY;
+ enum nl80211_band band;
+
+ mutex_lock(&local->scan_mtx);
+
+ /* busy scanning */
+ if (local->scan_req)
+ goto unlock;
+
+ /* fill internal scan request */
+ if (!chan) {
+ int i, nchan = 0;
+
+ for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
+ if (!local->hw.wiphy->bands[band])
+ continue;
+ for (i = 0;
+ i < local->hw.wiphy->bands[band]->n_channels;
+ i++) {
+ local->int_scan_req->channels[nchan] =
+ &local->hw.wiphy->bands[band]->channels[i];
+ nchan++;
+ }
}
- current_ev = ieee80211_sta_scan_result(local, info, bss,
- current_ev, end_buf);
+
+ local->int_scan_req->n_channels = nchan;
+ } else {
+ local->int_scan_req->channels[0] = chan;
+ local->int_scan_req->n_channels = 1;
}
- spin_unlock_bh(&local->sta_bss_lock);
- return current_ev - buf;
+
+ local->int_scan_req->ssids = &local->scan_ssid;
+ local->int_scan_req->n_ssids = 1;
+ memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
+ local->int_scan_req->ssids[0].ssid_len = ssid_len;
+
+ ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
+ unlock:
+ mutex_unlock(&local->scan_mtx);
+ return ret;
+}
+
+void ieee80211_scan_cancel(struct ieee80211_local *local)
+{
+ bool abortscan;
+
+ cancel_delayed_work_sync(&local->scan_work);
+
+ /*
+ * Only call this function when a scan can't be
+ * queued -- mostly at suspend under RTNL.
+ */
+ mutex_lock(&local->scan_mtx);
+ abortscan = test_bit(SCAN_SW_SCANNING, &local->scanning) ||
+ (!local->scanning && local->scan_req);
+ mutex_unlock(&local->scan_mtx);
+
+ if (abortscan)
+ ieee80211_scan_completed(&local->hw, true);
}