cregit-Linux how code gets into the kernel

Release 4.8 net/mac80211/scan.c

Directory: net/mac80211
/*
 * 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 2013-2015  Intel Mobile Communications GmbH
 * Copyright 2016  Intel Deutschland 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 <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)); }

Contributors

PersonTokensPropCommitsCommitProp
johannes bergjohannes berg44100.00%5100.00%
Total44100.00%5100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
kalle valokalle valo85100.00%1100.00%
Total85100.00%1100.00%


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; struct cfg80211_inform_bss bss_meta = { .boottime_ns = rx_status->boottime_ns, }; bool signal_valid; struct ieee80211_sub_if_data *scan_sdata; if (ieee80211_hw_check(&local->hw, SIGNAL_DBM)) bss_meta.signal = rx_status->signal * 100; else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC)) bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal; bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20; if (rx_status->flag & RX_FLAG_5MHZ) bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5; if (rx_status->flag & RX_FLAG_10MHZ) bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10; bss_meta.chan = channel; rcu_read_lock(); scan_sdata = rcu_dereference(local->scan_sdata); if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION && scan_sdata->vif.bss_conf.assoc && ieee80211_have_rx_timestamp(rx_status)) { bss_meta.parent_tsf = ieee80211_calculate_rx_timestamp(local, rx_status, len + FCS_LEN, 24); ether_addr_copy(bss_meta.parent_bssid, scan_sdata->vif.bss_conf.bssid); } rcu_read_unlock(); cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta, mgmt, len, GFP_ATOMIC); if (!cbss) return NULL; /* In case the signal is invalid update the status */ signal_valid = abs(channel->center_freq - cbss->channel->center_freq) <= local->hw.wiphy->max_adj_channel_rssi_comp; if (!signal_valid) rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL; 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; }

Contributors

PersonTokensPropCommitsCommitProp
johannes bergjohannes berg31645.47%1052.63%
paul stewartpaul stewart13619.57%15.26%
avraham sternavraham stern7911.37%15.26%
alexander bondaralexander bondar588.35%15.26%
sara sharonsara sharon385.47%15.26%
simon wunderlichsimon wunderlich294.17%15.26%
stanislaw gruszkastanislaw gruszka192.73%15.26%
emmanuel grumbachemmanuel grumbach101.44%15.26%
kalle valokalle valo91.29%15.26%
rusty russellrusty russell10.14%15.26%
Total695100.00%19100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
johannes bergjohannes berg34898.58%981.82%
jouni malinenjouni malinen41.13%19.09%
joe perchesjoe perches10.28%19.09%
Total353100.00%11100.00%


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; } }

Contributors

PersonTokensPropCommitsCommitProp
simon wunderlichsimon wunderlich62100.00%1100.00%
Total62100.00%1100.00%

/* 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 (ieee80211_hw_check(&local->hw, SINGLE_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 == NUM_NL80211_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); ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid); return true; }

Contributors

PersonTokensPropCommitsCommitProp
johannes bergjohannes berg21558.11%960.00%
david spinadeldavid spinadel10728.92%16.67%
jouni malinenjouni malinen174.59%320.00%
simon wunderlichsimon wunderlich164.32%16.67%
emmanuel grumbachemmanuel grumbach154.05%16.67%
Total370100.00%15100.00%


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; struct ieee80211_sub_if_data *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 && !ieee80211_hw_check(&local->hw, SINGLE_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; /* HW scan failed and is going to be reported as aborted, * so clear old scan info. */ memset(&local->scan_info, 0, sizeof(local->scan_info)); aborted = true; } 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) { local->scan_info.aborted = aborted; cfg80211_scan_done(scan_req, &local->scan_info); } 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); /* Requeue all the work that might have been ignored while * the scan was in progress; if there was none this will * just be a no-op for the particular interface. */ list_for_each_entry_rcu(sdata, &local->interfaces, list) { if (ieee80211_sdata_running(sdata)) ieee80211_queue_work(&sdata->local->hw, &sdata->work); } if (was_scanning) ieee80211_start_next_roc(local); }

Contributors

PersonTokensPropCommitsCommitProp
johannes bergjohannes berg24164.96%2564.10%
sachin kulkarnisachin kulkarni349.16%12.56%
avraham sternavraham stern318.36%25.13%
eliad pellereliad peller225.93%25.13%
stanislaw gruszkastanislaw gruszka164.31%25.13%
ben greearben greear102.70%25.13%
david spinadeldavid spinadel51.35%12.56%
luis r. rodriguezluis r. rodriguez51.35%12.56%
helmut schaahelmut schaa30.81%12.56%
simon wunderlichsimon wunderlich30.81%12.56%
monam agarwalmonam agarwal10.27%12.56%
Total371100.00%39100.00%


void ieee80211_scan_completed(struct ieee80211_hw *hw, struct cfg80211_scan_info *info) { struct ieee80211_local *local = hw_to_local(hw); trace_api_scan_completed(local, info); set_bit(SCAN_COMPLETED, &local->scanning); if (info->aborted) set_bit(SCAN_ABORTED, &local->scanning); memcpy(&local->scan_info, info, sizeof(*info)); ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); }

Contributors

PersonTokensPropCommitsCommitProp
johannes bergjohannes berg6674.16%150.00%
avraham sternavraham stern2325.84%150.00%
Total89100.00%2100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
johannes bergjohannes berg7774.76%1055.56%
ben greearben greear87.77%15.56%
helmut schaahelmut schaa76.80%316.67%
seth forsheeseth forshee65.83%15.56%
luis r. rodriguezluis r. rodriguez21.94%15.56%
emmanuel grumbachemmanuel grumbach21.94%15.56%
rajkumar manoharanrajkumar manoharan10.97%15.56%
Total103100.00%18100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
stanislaw gruszkastanislaw gruszka5583.33%125.00%
simon wunderlichsimon wunderlich710.61%125.00%
eliad pellereliad peller34.55%125.00%
johannes bergjohannes berg11.52%125.00%
Total66100.00%4100.00%


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)); }

Contributors

PersonTokensPropCommitsCommitProp
stanislaw gruszkastanislaw gruszka6184.72%150.00%
johannes bergjohannes berg1115.28%150.00%
Total72100.00%2100.00%


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 nl80211_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, scan_req->bssid, 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; }

Contributors

PersonTokensPropCommitsCommitProp
ben greearben greear10556.76%110.00%
johannes bergjohannes berg5328.65%660.00%
seth forsheeseth forshee189.73%110.00%
karl beldankarl beldan63.24%110.00%
jouni malinenjouni malinen31.62%110.00%
Total185100.00%10100.00%


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 (ieee80211_hw_check(&local->hw, SINGLE_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; eth_broadcast_addr(local->hw_scan_req->req.bssid); local->hw_scan_req->req.duration = req->duration; local->hw_scan_req->req.duration_mandatory = req->duration_mandatory; 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