| /* |
| * 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 (local->radar_detect_enabled) |
| 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) |
| 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); |
| |
| 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 *chan, |
| enum nl80211_bss_scan_width scan_width) |
| { |
| struct ieee80211_local *local = sdata->local; |
| int ret = -EBUSY; |
| enum ieee80211_band band; |
| |
| mutex_lock(&local->mtx); |
| |
| /* busy scanning */ |
| if (local->scan_req) |
| goto unlock; |
| |
| /* fill internal scan request */ |
| if (!chan) { |
| int i, max_n; |
| int n_ch = 0; |
| |
| 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 { |
| if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IR | |
| IEEE80211_CHAN_DISABLED))) |
| goto unlock; |
| |
| local->int_scan_req->channels[0] = chan; |
| local->int_scan_req->n_channels = 1; |
| } |
| |
| 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); |