--- /dev/null
+/*
+ * Scanning implementation
+ *
+ * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
+ * Copyright 2004, Instant802 Networks, Inc.
+ * Copyright 2005, Devicescape Software, Inc.
+ * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
+ * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
+ * Copyright 2013-2014 Intel Mobile Communications GmbH
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/if_arp.h>
+#include <linux/etherdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/pm_qos.h>
+#include <net/sch_generic.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <net/mac80211.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 / 9)
+
+void ieee80211_rx_bss_put(struct ieee80211_local *local,
+ struct ieee80211_bss *bss)
+{
+ if (!bss)
+ return;
+ cfg80211_put_bss(local->hw.wiphy,
+ container_of((void *)bss, struct cfg80211_bss, priv));
+}
+
+static bool is_uapsd_supported(struct ieee802_11_elems *elems)
+{
+ 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;
+}
+
+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 = ieee80211_is_beacon(mgmt->frame_control);
+ struct cfg80211_bss *cbss;
+ struct ieee80211_bss *bss;
+ int clen, srlen;
+ enum nl80211_bss_scan_width scan_width;
+ s32 signal = 0;
+
+ 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;
+
+ scan_width = NL80211_BSS_CHAN_WIDTH_20;
+ if (rx_status->flag & RX_FLAG_5MHZ)
+ scan_width = NL80211_BSS_CHAN_WIDTH_5;
+ if (rx_status->flag & RX_FLAG_10MHZ)
+ scan_width = NL80211_BSS_CHAN_WIDTH_10;
+
+ cbss = cfg80211_inform_bss_width_frame(local->hw.wiphy, channel,
+ scan_width, mgmt, len, signal,
+ GFP_ATOMIC);
+ if (!cbss)
+ return NULL;
+
+ bss = (void *)cbss->priv;
+
+ if (beacon)
+ bss->device_ts_beacon = rx_status->device_timestamp;
+ else
+ bss->device_ts_presp = rx_status->device_timestamp;
+
+ if (elems->parse_error) {
+ if (beacon)
+ bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
+ else
+ bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
+ } else {
+ if (beacon)
+ bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
+ else
+ bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
+ }
+
+ /* save the ERP value so that it is available at association time */
+ if (elems->erp_info && (!elems->parse_error ||
+ !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
+ bss->erp_value = elems->erp_info[0];
+ bss->has_erp_value = true;
+ if (!elems->parse_error)
+ bss->valid_data |= IEEE80211_BSS_VALID_ERP;
+ }
+
+ /* replace old supported rates if we get new values */
+ if (!elems->parse_error ||
+ !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
+ 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;
+ }
+ if (srlen) {
+ bss->supp_rates_len = srlen;
+ if (!elems->parse_error)
+ bss->valid_data |= IEEE80211_BSS_VALID_RATES;
+ }
+ }
+
+ if (!elems->parse_error ||
+ !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
+ bss->wmm_used = elems->wmm_param || elems->wmm_info;
+ bss->uapsd_supported = is_uapsd_supported(elems);
+ if (!elems->parse_error)
+ bss->valid_data |= IEEE80211_BSS_VALID_WMM;
+ }
+
+ if (beacon) {
+ struct ieee80211_supported_band *sband =
+ local->hw.wiphy->bands[rx_status->band];
+ if (!(rx_status->flag & RX_FLAG_HT) &&
+ !(rx_status->flag & RX_FLAG_VHT))
+ bss->beacon_rate =
+ &sband->bitrates[rx_status->rate_idx];
+ }
+
+ return bss;
+}
+
+void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
+{
+ struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
+ struct ieee80211_sub_if_data *sdata1, *sdata2;
+ struct ieee80211_mgmt *mgmt = (void *)skb->data;
+ struct ieee80211_bss *bss;
+ u8 *elements;
+ struct ieee80211_channel *channel;
+ size_t baselen;
+ struct ieee802_11_elems elems;
+
+ if (skb->len < 24 ||
+ (!ieee80211_is_probe_resp(mgmt->frame_control) &&
+ !ieee80211_is_beacon(mgmt->frame_control)))
+ return;
+
+ sdata1 = rcu_dereference(local->scan_sdata);
+ sdata2 = rcu_dereference(local->sched_scan_sdata);
+
+ if (likely(!sdata1 && !sdata2))
+ return;
+
+ if (ieee80211_is_probe_resp(mgmt->frame_control)) {
+ struct cfg80211_scan_request *scan_req;
+ struct cfg80211_sched_scan_request *sched_scan_req;
+
+ scan_req = rcu_dereference(local->scan_req);
+ sched_scan_req = rcu_dereference(local->sched_scan_req);
+
+ /* ignore ProbeResp to foreign address unless scanning
+ * with randomised address
+ */
+ if (!(sdata1 &&
+ (ether_addr_equal(mgmt->da, sdata1->vif.addr) ||
+ scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)) &&
+ !(sdata2 &&
+ (ether_addr_equal(mgmt->da, sdata2->vif.addr) ||
+ sched_scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)))
+ return;
+
+ elements = mgmt->u.probe_resp.variable;
+ baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
+ } else {
+ baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
+ elements = mgmt->u.beacon.variable;
+ }
+
+ if (baselen > skb->len)
+ return;
+
+ ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
+
+ channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
+
+ if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
+ return;
+
+ bss = ieee80211_bss_info_update(local, rx_status,
+ mgmt, skb->len, &elems,
+ channel);
+ if (bss)
+ ieee80211_rx_bss_put(local, bss);
+}
+
+static void
+ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
+ enum nl80211_bss_scan_width scan_width)
+{
+ memset(chandef, 0, sizeof(*chandef));
+ switch (scan_width) {
+ case NL80211_BSS_CHAN_WIDTH_5:
+ chandef->width = NL80211_CHAN_WIDTH_5;
+ break;
+ case NL80211_BSS_CHAN_WIDTH_10:
+ chandef->width = NL80211_CHAN_WIDTH_10;
+ break;
+ default:
+ chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
+ break;
+ }
+}
+
+/* return false if no more work */
+static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
+{
+ struct cfg80211_scan_request *req;
+ struct cfg80211_chan_def chandef;
+ u8 bands_used = 0;
+ int i, ielen, n_chans;
+
+ req = rcu_dereference_protected(local->scan_req,
+ lockdep_is_held(&local->mtx));
+
+ if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
+ return false;
+
+ if (local->hw.flags & IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS) {
+ for (i = 0; i < req->n_channels; i++) {
+ local->hw_scan_req->req.channels[i] = req->channels[i];
+ bands_used |= BIT(req->channels[i]->band);
+ }
+
+ n_chans = req->n_channels;
+ } else {
+ do {
+ if (local->hw_scan_band == IEEE80211_NUM_BANDS)
+ return false;
+
+ n_chans = 0;
+
+ for (i = 0; i < req->n_channels; i++) {
+ if (req->channels[i]->band !=
+ local->hw_scan_band)
+ continue;
+ local->hw_scan_req->req.channels[n_chans] =
+ req->channels[i];
+ n_chans++;
+ bands_used |= BIT(req->channels[i]->band);
+ }
+
+ local->hw_scan_band++;
+ } while (!n_chans);
+ }
+
+ local->hw_scan_req->req.n_channels = n_chans;
+ ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
+
+ ielen = ieee80211_build_preq_ies(local,
+ (u8 *)local->hw_scan_req->req.ie,
+ local->hw_scan_ies_bufsize,
+ &local->hw_scan_req->ies,
+ req->ie, req->ie_len,
+ bands_used, req->rates, &chandef);
+ local->hw_scan_req->req.ie_len = ielen;
+ local->hw_scan_req->req.no_cck = req->no_cck;
+ ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
+ ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
+ req->mac_addr_mask);
+
+ return true;
+}
+
+static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
+{
+ struct ieee80211_local *local = hw_to_local(hw);
+ bool hw_scan = local->ops->hw_scan;
+ bool was_scanning = local->scanning;
+ struct cfg80211_scan_request *scan_req;
+ struct ieee80211_sub_if_data *scan_sdata;
+
+ lockdep_assert_held(&local->mtx);
+
+ /*
+ * 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))
+ return;
+
+ if (hw_scan && !aborted &&
+ !(local->hw.flags & IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS) &&
+ ieee80211_prep_hw_scan(local)) {
+ int rc;
+
+ rc = drv_hw_scan(local,
+ rcu_dereference_protected(local->scan_sdata,
+ lockdep_is_held(&local->mtx)),
+ local->hw_scan_req);
+
+ if (rc == 0)
+ return;
+ }
+
+ kfree(local->hw_scan_req);
+ local->hw_scan_req = NULL;
+
+ scan_req = rcu_dereference_protected(local->scan_req,
+ lockdep_is_held(&local->mtx));
+
+ if (scan_req != local->int_scan_req)
+ cfg80211_scan_done(scan_req, aborted);
+ RCU_INIT_POINTER(local->scan_req, NULL);
+
+ scan_sdata = rcu_dereference_protected(local->scan_sdata,
+ lockdep_is_held(&local->mtx));
+ RCU_INIT_POINTER(local->scan_sdata, NULL);
+
+ local->scanning = 0;
+ local->scan_chandef.chan = NULL;
+
+ /* Set power back to normal operating levels. */
+ ieee80211_hw_config(local, 0);
+
+ if (!hw_scan) {
+ ieee80211_configure_filter(local);
+ drv_sw_scan_complete(local, scan_sdata);
+ ieee80211_offchannel_return(local);
+ }
+
+ ieee80211_recalc_idle(local);
+
+ ieee80211_mlme_notify_scan_completed(local);
+ ieee80211_ibss_notify_scan_completed(local);
+ ieee80211_mesh_notify_scan_completed(local);
+ if (was_scanning)
+ ieee80211_start_next_roc(local);
+}
+
+void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
+{
+ struct ieee80211_local *local = hw_to_local(hw);
+
+ trace_api_scan_completed(local, aborted);
+
+ set_bit(SCAN_COMPLETED, &local->scanning);
+ if (aborted)
+ set_bit(SCAN_ABORTED, &local->scanning);
+ ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
+}
+EXPORT_SYMBOL(ieee80211_scan_completed);
+
+static int ieee80211_start_sw_scan(struct ieee80211_local *local,
+ struct ieee80211_sub_if_data *sdata)
+{
+ /* Software scan is not supported in multi-channel cases */
+ if (local->use_chanctx)
+ return -EOPNOTSUPP;
+
+ /*
+ * 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, sdata, local->scan_addr);
+
+ local->leave_oper_channel_time = jiffies;
+ local->next_scan_state = SCAN_DECISION;
+ local->scan_channel_idx = 0;
+
+ ieee80211_offchannel_stop_vifs(local);
+
+ /* ensure nullfunc is transmitted before leaving operating channel */
+ ieee80211_flush_queues(local, NULL, false);
+
+ ieee80211_configure_filter(local);
+
+ /* We need to set power level at maximum rate for scanning. */
+ ieee80211_hw_config(local, 0);
+
+ ieee80211_queue_delayed_work(&local->hw,
+ &local->scan_work, 0);
+
+ return 0;
+}
+
+static bool ieee80211_can_scan(struct ieee80211_local *local,
+ struct ieee80211_sub_if_data *sdata)
+{
+ if (ieee80211_is_radar_required(local))
+ return false;
+
+ if (!list_empty(&local->roc_list))
+ return false;
+
+ if (sdata->vif.type == NL80211_IFTYPE_STATION &&
+ sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
+ return false;
+
+ return true;
+}
+
+void ieee80211_run_deferred_scan(struct ieee80211_local *local)
+{
+ lockdep_assert_held(&local->mtx);
+
+ if (!local->scan_req || local->scanning)
+ return;
+
+ if (!ieee80211_can_scan(local,
+ rcu_dereference_protected(
+ local->scan_sdata,
+ lockdep_is_held(&local->mtx))))
+ return;
+
+ ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
+ round_jiffies_relative(0));
+}
+
+static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
+ unsigned long *next_delay)
+{
+ int i;
+ struct ieee80211_sub_if_data *sdata;
+ struct cfg80211_scan_request *scan_req;
+ enum ieee80211_band band = local->hw.conf.chandef.chan->band;
+ u32 tx_flags;
+
+ scan_req = rcu_dereference_protected(local->scan_req,
+ lockdep_is_held(&local->mtx));
+
+ tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
+ if (scan_req->no_cck)
+ tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
+
+ sdata = rcu_dereference_protected(local->scan_sdata,
+ lockdep_is_held(&local->mtx));
+
+ for (i = 0; i < scan_req->n_ssids; i++)
+ ieee80211_send_probe_req(
+ sdata, local->scan_addr, NULL,
+ scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
+ scan_req->ie, scan_req->ie_len,
+ scan_req->rates[band], false,
+ tx_flags, local->hw.conf.chandef.chan, true);
+
+ /*
+ * After sending probe requests, wait for probe responses
+ * on the channel.
+ */
+ *next_delay = IEEE80211_CHANNEL_TIME;
+ local->next_scan_state = SCAN_DECISION;
+}
+
+static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
+ struct cfg80211_scan_request *req)
+{
+ struct ieee80211_local *local = sdata->local;
+ int rc;
+
+ lockdep_assert_held(&local->mtx);
+
+ if (local->scan_req || ieee80211_is_radar_required(local))
+ return -EBUSY;
+
+ if (!ieee80211_can_scan(local, sdata)) {
+ /* wait for the work to finish/time out */
+ rcu_assign_pointer(local->scan_req, req);
+ rcu_assign_pointer(local->scan_sdata, sdata);
+ return 0;
+ }
+
+ if (local->ops->hw_scan) {
+ u8 *ies;
+
+ local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
+
+ if (local->hw.flags & IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS) {
+ int i, n_bands = 0;
+ u8 bands_counted = 0;
+
+ for (i = 0; i < req->n_channels; i++) {
+ if (bands_counted & BIT(req->channels[i]->band))
+ continue;
+ bands_counted |= BIT(req->channels[i]->band);
+ n_bands++;
+ }
+
+ local->hw_scan_ies_bufsize *= n_bands;
+ }
+
+ local->hw_scan_req = kmalloc(
+ sizeof(*local->hw_scan_req) +
+ req->n_channels * sizeof(req->channels[0]) +
+ local->hw_scan_ies_bufsize, GFP_KERNEL);
+ if (!local->hw_scan_req)
+ return -ENOMEM;
+
+ local->hw_scan_req->req.ssids = req->ssids;
+ local->hw_scan_req->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->req.ie = ies;
+ local->hw_scan_req->req.flags = req->flags;
+
+ 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_assign_pointer(local->scan_req, req);
+ rcu_assign_pointer(local->scan_sdata, sdata);
+
+ if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
+ get_random_mask_addr(local->scan_addr,
+ req->mac_addr,
+ req->mac_addr_mask);
+ else
+ memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
+
+ if (local->ops->hw_scan) {
+ __set_bit(SCAN_HW_SCANNING, &local->scanning);
+ } else if ((req->n_channels == 1) &&
+ (req->channels[0] == local->_oper_chandef.chan)) {
+ /*
+ * If we are scanning only on the operating channel
+ * then we do not need to stop normal activities
+ */
+ unsigned long next_delay;
+
+ __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
+
+ ieee80211_recalc_idle(local);
+
+ /* Notify driver scan is starting, keep order of operations
+ * same as normal software scan, in case that matters. */
+ drv_sw_scan_start(local, sdata, local->scan_addr);
+
+ ieee80211_configure_filter(local); /* accept probe-responses */
+
+ /* We need to ensure power level is at max for scanning. */
+ ieee80211_hw_config(local, 0);
+
+ if ((req->channels[0]->flags &
+ IEEE80211_CHAN_NO_IR) ||
+ !req->n_ssids) {
+ next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
+ } else {
+ ieee80211_scan_state_send_probe(local, &next_delay);
+ next_delay = IEEE80211_CHANNEL_TIME;
+ }
+
+ /* Now, just wait a bit and we are all done! */
+ ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
+ next_delay);
+ return 0;
+ } else {
+ /* Do normal software scan */
+ __set_bit(SCAN_SW_SCANNING, &local->scanning);
+ }
+
+ ieee80211_recalc_idle(local);
+
+ if (local->ops->hw_scan) {
+ WARN_ON(!ieee80211_prep_hw_scan(local));
+ rc = drv_hw_scan(local, sdata, local->hw_scan_req);
+ } else {
+ rc = ieee80211_start_sw_scan(local, sdata);
+ }
+
+ if (rc) {
+ kfree(local->hw_scan_req);
+ local->hw_scan_req = NULL;
+ local->scanning = 0;
+
+ ieee80211_recalc_idle(local);
+
+ local->scan_req = NULL;
+ RCU_INIT_POINTER(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_NO_IR)
+ return IEEE80211_PASSIVE_CHANNEL_TIME;
+ return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
+}
+
+static void ieee80211_scan_state_decision(struct ieee80211_local *local,
+ unsigned long *next_delay)
+{
+ bool associated = false;
+ bool tx_empty = true;
+ bool bad_latency;
+ struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_channel *next_chan;
+ enum mac80211_scan_state next_scan_state;
+ struct cfg80211_scan_request *scan_req;
+
+ /*
+ * 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 (!qdisc_all_tx_empty(sdata->dev)) {
+ tx_empty = false;
+ break;
+ }
+ }
+ }
+ }
+ mutex_unlock(&local->iflist_mtx);
+
+ scan_req = rcu_dereference_protected(local->scan_req,
+ lockdep_is_held(&local->mtx));
+
+ next_chan = scan_req->channels[local->scan_channel_idx];
+
+ /*
+ * we're currently scanning a different channel, let's
+ * see if we can scan another channel without interfering
+ * with the current traffic situation.
+ *
+ * Keep good latency, do not stay off-channel more than 125 ms.
+ */
+
+ bad_latency = time_after(jiffies +
+ ieee80211_scan_get_channel_time(next_chan),
+ local->leave_oper_channel_time + HZ / 8);
+
+ if (associated && !tx_empty) {
+ if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
+ next_scan_state = SCAN_ABORT;
+ else
+ next_scan_state = SCAN_SUSPEND;
+ } else if (associated && bad_latency) {
+ next_scan_state = SCAN_SUSPEND;
+ } else {
+ next_scan_state = SCAN_SET_CHANNEL;
+ }
+
+ local->next_scan_state = next_scan_state;
+
+ *next_delay = 0;
+}
+
+static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
+ unsigned long *next_delay)
+{
+ int skip;
+ struct ieee80211_channel *chan;
+ enum nl80211_bss_scan_width oper_scan_width;
+ struct cfg80211_scan_request *scan_req;
+
+ scan_req = rcu_dereference_protected(local->scan_req,
+ lockdep_is_held(&local->mtx));
+
+ skip = 0;
+ chan = scan_req->channels[local->scan_channel_idx];
+
+ local->scan_chandef.chan = chan;
+ local->scan_chandef.center_freq1 = chan->center_freq;
+ local->scan_chandef.center_freq2 = 0;
+ switch (scan_req->scan_width) {
+ case NL80211_BSS_CHAN_WIDTH_5:
+ local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
+ break;
+ case NL80211_BSS_CHAN_WIDTH_10:
+ local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
+ break;
+ case NL80211_BSS_CHAN_WIDTH_20:
+ /* If scanning on oper channel, use whatever channel-type
+ * is currently in use.
+ */
+ oper_scan_width = cfg80211_chandef_to_scan_width(
+ &local->_oper_chandef);
+ if (chan == local->_oper_chandef.chan &&
+ oper_scan_width == scan_req->scan_width)
+ local->scan_chandef = local->_oper_chandef;
+ else
+ local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
+ break;
+ }
+
+ 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_NO_IR || !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_suspend(struct ieee80211_local *local,
+ unsigned long *next_delay)
+{
+ /* switch back to the operating channel */
+ local->scan_chandef.chan = NULL;
+ ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
+
+ /* disable PS */
+ ieee80211_offchannel_return(local);
+
+ *next_delay = HZ / 5;
+ /* afterwards, resume scan & go to next channel */
+ local->next_scan_state = SCAN_RESUME;
+}
+
+static void ieee80211_scan_state_resume(struct ieee80211_local *local,
+ unsigned long *next_delay)
+{
+ ieee80211_offchannel_stop_vifs(local);
+
+ if (local->ops->flush) {
+ ieee80211_flush_queues(local, NULL, false);
+ *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;
+}
+
+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;
+ struct cfg80211_scan_request *scan_req;
+ unsigned long next_delay = 0;
+ bool aborted;
+
+ mutex_lock(&local->mtx);
+
+ if (!ieee80211_can_run_worker(local)) {
+ aborted = true;
+ goto out_complete;
+ }
+
+ sdata = rcu_dereference_protected(local->scan_sdata,
+ lockdep_is_held(&local->mtx));
+ scan_req = rcu_dereference_protected(local->scan_req,
+ lockdep_is_held(&local->mtx));
+
+ /* When scanning on-channel, the first-callback means completed. */
+ if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
+ aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
+ goto out_complete;
+ }
+
+ if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
+ aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
+ goto out_complete;
+ }
+
+ if (!sdata || !scan_req)
+ goto out;
+
+ if (!local->scanning) {
+ int rc;
+
+ RCU_INIT_POINTER(local->scan_req, NULL);
+ RCU_INIT_POINTER(local->scan_sdata, NULL);
+
+ rc = __ieee80211_start_scan(sdata, scan_req);
+ if (rc) {
+ /* need to complete scan in cfg80211 */
+ rcu_assign_pointer(local->scan_req, scan_req);
+ aborted = true;
+ goto out_complete;
+ } else
+ goto out;
+ }
+
+ /*
+ * as long as no delay is required advance immediately
+ * without scheduling a new work
+ */
+ do {
+ if (!ieee80211_sdata_running(sdata)) {
+ aborted = true;
+ goto out_complete;
+ }
+
+ switch (local->next_scan_state) {
+ case SCAN_DECISION:
+ /* if no more bands/channels left, complete scan */
+ if (local->scan_channel_idx >= scan_req->n_channels) {
+ aborted = false;
+ goto out_complete;
+ }
+ ieee80211_scan_state_decision(local, &next_delay);
+ 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_SUSPEND:
+ ieee80211_scan_state_suspend(local, &next_delay);
+ break;
+ case SCAN_RESUME:
+ ieee80211_scan_state_resume(local, &next_delay);
+ break;
+ case SCAN_ABORT:
+ aborted = true;
+ goto out_complete;
+ }
+ } while (next_delay == 0);
+
+ ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
+ goto out;
+
+out_complete:
+ __ieee80211_scan_completed(&local->hw, aborted);
+out:
+ mutex_unlock(&local->mtx);
+}
+
+int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
+ struct cfg80211_scan_request *req)
+{
+ int res;
+
+ mutex_lock(&sdata->local->mtx);
+ res = __ieee80211_start_scan(sdata, req);
+ mutex_unlock(&sdata->local->mtx);
+
+ return res;
+}
+
+int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
+ const u8 *ssid, u8 ssid_len,
+ struct ieee80211_channel **channels,
+ unsigned int n_channels,
+ enum nl80211_bss_scan_width scan_width)
+{
+ struct ieee80211_local *local = sdata->local;
+ int ret = -EBUSY, i, n_ch = 0;
+ enum ieee80211_band band;
+
+ mutex_lock(&local->mtx);
+
+ /* busy scanning */
+ if (local->scan_req)
+ goto unlock;
+
+ /* fill internal scan request */
+ if (!channels) {
+ int max_n;
+
+ for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
+ if (!local->hw.wiphy->bands[band])
+ continue;
+
+ max_n = local->hw.wiphy->bands[band]->n_channels;
+ for (i = 0; i < max_n; i++) {
+ struct ieee80211_channel *tmp_ch =
+ &local->hw.wiphy->bands[band]->channels[i];
+
+ if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
+ IEEE80211_CHAN_DISABLED))
+ continue;
+
+ local->int_scan_req->channels[n_ch] = tmp_ch;
+ n_ch++;
+ }
+ }
+
+ if (WARN_ON_ONCE(n_ch == 0))
+ goto unlock;
+
+ local->int_scan_req->n_channels = n_ch;
+ } else {
+ for (i = 0; i < n_channels; i++) {
+ if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
+ IEEE80211_CHAN_DISABLED))
+ continue;
+
+ local->int_scan_req->channels[n_ch] = channels[i];
+ n_ch++;
+ }
+
+ if (WARN_ON_ONCE(n_ch == 0))
+ goto unlock;
+
+ local->int_scan_req->n_channels = n_ch;
+ }
+
+ local->int_scan_req->ssids = &local->scan_ssid;
+ local->int_scan_req->n_ssids = 1;
+ local->int_scan_req->scan_width = scan_width;
+ 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->mtx);
+ return ret;
+}
+
+/*
+ * Only call this function when a scan can't be queued -- under RTNL.
+ */
+void ieee80211_scan_cancel(struct ieee80211_local *local)
+{
+ /*
+ * We are canceling software scan, or deferred scan that was not
+ * yet really started (see __ieee80211_start_scan ).
+ *
+ * Regarding hardware scan:
+ * - we can not call __ieee80211_scan_completed() as when
+ * SCAN_HW_SCANNING bit is set this function change
+ * local->hw_scan_req to operate on 5G band, what race with
+ * driver which can use local->hw_scan_req
+ *
+ * - we can not cancel scan_work since driver can schedule it
+ * by ieee80211_scan_completed(..., true) to finish scan
+ *
+ * Hence we only call the cancel_hw_scan() callback, but the low-level
+ * driver is still responsible for calling ieee80211_scan_completed()
+ * after the scan was completed/aborted.
+ */
+
+ mutex_lock(&local->mtx);
+ if (!local->scan_req)
+ goto out;
+
+ /*
+ * We have a scan running and the driver already reported completion,
+ * but the worker hasn't run yet or is stuck on the mutex - mark it as
+ * cancelled.
+ */
+ if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
+ test_bit(SCAN_COMPLETED, &local->scanning)) {
+ set_bit(SCAN_HW_CANCELLED, &local->scanning);
+ goto out;
+ }
+
+ if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
+ /*
+ * Make sure that __ieee80211_scan_completed doesn't trigger a
+ * scan on another band.
+ */
+ set_bit(SCAN_HW_CANCELLED, &local->scanning);
+ if (local->ops->cancel_hw_scan)
+ drv_cancel_hw_scan(local,
+ rcu_dereference_protected(local->scan_sdata,
+ lockdep_is_held(&local->mtx)));
+ goto out;
+ }
+
+ /*
+ * If the work is currently running, it must be blocked on
+ * the mutex, but we'll set scan_sdata = NULL and it'll
+ * simply exit once it acquires the mutex.
+ */
+ cancel_delayed_work(&local->scan_work);
+ /* and clean up */
+ __ieee80211_scan_completed(&local->hw, true);
+out:
+ mutex_unlock(&local->mtx);
+}
+
+int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
+ struct cfg80211_sched_scan_request *req)
+{
+ struct ieee80211_local *local = sdata->local;
+ struct ieee80211_scan_ies sched_scan_ies = {};
+ struct cfg80211_chan_def chandef;
+ int ret, i, iebufsz, num_bands = 0;
+ u32 rate_masks[IEEE80211_NUM_BANDS] = {};
+ u8 bands_used = 0;
+ u8 *ie;
+ size_t len;
+
+ iebufsz = local->scan_ies_len + req->ie_len;
+
+ lockdep_assert_held(&local->mtx);
+
+ if (!local->ops->sched_scan_start)
+ return -ENOTSUPP;
+
+ for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
+ if (local->hw.wiphy->bands[i]) {
+ bands_used |= BIT(i);
+ rate_masks[i] = (u32) -1;
+ num_bands++;
+ }
+ }
+
+ ie = kzalloc(num_bands * iebufsz, GFP_KERNEL);
+ if (!ie) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
+
+ len = ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
+ &sched_scan_ies, req->ie,
+ req->ie_len, bands_used,
+ rate_masks, &chandef);
+
+ ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
+ if (ret == 0) {
+ rcu_assign_pointer(local->sched_scan_sdata, sdata);
+ rcu_assign_pointer(local->sched_scan_req, req);
+ }
+
+ kfree(ie);
+
+out:
+ if (ret) {
+ /* Clean in case of failure after HW restart or upon resume. */
+ RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
+ RCU_INIT_POINTER(local->sched_scan_req, NULL);
+ }
+
+ return ret;
+}
+
+int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
+ struct cfg80211_sched_scan_request *req)
+{
+ struct ieee80211_local *local = sdata->local;
+ int ret;
+
+ mutex_lock(&local->mtx);
+
+ if (rcu_access_pointer(local->sched_scan_sdata)) {
+ mutex_unlock(&local->mtx);
+ return -EBUSY;
+ }
+
+ ret = __ieee80211_request_sched_scan_start(sdata, req);
+
+ mutex_unlock(&local->mtx);
+ return ret;
+}
+
+int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
+{
+ struct ieee80211_local *local = sdata->local;
+ int ret = 0;
+
+ mutex_lock(&local->mtx);
+
+ if (!local->ops->sched_scan_stop) {
+ ret = -ENOTSUPP;
+ goto out;
+ }
+
+ /* We don't want to restart sched scan anymore. */
+ RCU_INIT_POINTER(local->sched_scan_req, NULL);
+
+ if (rcu_access_pointer(local->sched_scan_sdata)) {
+ ret = drv_sched_scan_stop(local, sdata);
+ if (!ret)
+ RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
+ }
+out:
+ mutex_unlock(&local->mtx);
+
+ return ret;
+}
+
+void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
+{
+ struct ieee80211_local *local = hw_to_local(hw);
+
+ trace_api_sched_scan_results(local);
+
+ cfg80211_sched_scan_results(hw->wiphy);
+}
+EXPORT_SYMBOL(ieee80211_sched_scan_results);
+
+void ieee80211_sched_scan_end(struct ieee80211_local *local)
+{
+ mutex_lock(&local->mtx);
+
+ if (!rcu_access_pointer(local->sched_scan_sdata)) {
+ mutex_unlock(&local->mtx);
+ return;
+ }
+
+ RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
+
+ /* If sched scan was aborted by the driver. */
+ RCU_INIT_POINTER(local->sched_scan_req, NULL);
+
+ mutex_unlock(&local->mtx);
+
+ cfg80211_sched_scan_stopped(local->hw.wiphy);
+}
+
+void ieee80211_sched_scan_stopped_work(struct work_struct *work)
+{
+ struct ieee80211_local *local =
+ container_of(work, struct ieee80211_local,
+ sched_scan_stopped_work);
+
+ ieee80211_sched_scan_end(local);
+}
+
+void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
+{
+ struct ieee80211_local *local = hw_to_local(hw);
+
+ trace_api_sched_scan_stopped(local);
+
+ schedule_work(&local->sched_scan_stopped_work);
+}
+EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
Code Review / kvmfornfv.git / blobdiff