Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-06 20:21:57 +00:00
Code Issues Packages Projects Releases Wiki Activity
fde0133b9c
linux/net/mac80211/ibss.c
Emmanuel Grumbach 3afc2167f6 cfg80211/mac80211: ignore signal if the frame was heard on wrong channel 
On 2.4Ghz band, the channels overlap since the delta
between different channels is 5Mhz while the width of the
receiver is 20Mhz (at least).

This means that we can hear beacons or probe responses from
adjacent channels. These frames will have a significant
lower RSSI which will feed all kinds of logic with inaccurate
data. An obvious example is the roaming algorithm that will
think our AP is getting weak and will try to move to another
AP.

In order to avoid this, update the signal only if the frame
has been heard on the same channel as the one advertised by
the AP in its DS / HT IEs.
We refrain from updating the values only if the AP is
already in the BSS list so that we will still have a valid
(but inaccurate) value if the AP was heard on an adjacent
channel only.

To achieve this, stop taking the channel from DS / HT IEs
in mac80211. The DS / HT IEs is taken into account to
discard the frame if it was received on a disabled channel.
This can happen due to the same phenomenon: the frame is
sent on channel 12, but heard on channel 11 while channel
12 can be disabled on certain devices. Since this check
is done in cfg80211, stop even checking this in mac80211.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
[remove unused rx_freq variable]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2014-03-19 21:29:56 +01:00

1733 lines
47 KiB
C
Raw Blame History

/*
* IBSS mode implementation
* Copyright 2003-2008, Jouni Malinen <j@w1.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 2009, Johannes Berg <johannes@sipsolutions.net>
*
* 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/delay.h>
#include <linux/slab.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "driver-ops.h"
#include "rate.h"
#define IEEE80211_SCAN_INTERVAL (2 * HZ)
#define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
#define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
#define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
#define IEEE80211_IBSS_RSN_INACTIVITY_LIMIT (10 * HZ)
#define IEEE80211_IBSS_MAX_STA_ENTRIES 128
static struct beacon_data *
ieee80211_ibss_build_presp(struct ieee80211_sub_if_data *sdata,
const int beacon_int, const u32 basic_rates,
const u16 capability, u64 tsf,
struct cfg80211_chan_def *chandef,
bool *have_higher_than_11mbit,
struct cfg80211_csa_settings *csa_settings)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
int rates_n = 0, i, ri;
struct ieee80211_mgmt *mgmt;
u8 *pos;
struct ieee80211_supported_band *sband;
u32 rate_flags, rates = 0, rates_added = 0;
struct beacon_data *presp;
int frame_len;
int shift;
/* Build IBSS probe response */
frame_len = sizeof(struct ieee80211_hdr_3addr) +
12 /* struct ieee80211_mgmt.u.beacon */ +
2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
2 + 8 /* max Supported Rates */ +
3 /* max DS params */ +
4 /* IBSS params */ +
5 /* Channel Switch Announcement */ +
2 + (IEEE80211_MAX_SUPP_RATES - 8) +
2 + sizeof(struct ieee80211_ht_cap) +
2 + sizeof(struct ieee80211_ht_operation) +
ifibss->ie_len;
presp = kzalloc(sizeof(*presp) + frame_len, GFP_KERNEL);
if (!presp)
return NULL;
presp->head = (void *)(presp + 1);
mgmt = (void *) presp->head;
mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
IEEE80211_STYPE_PROBE_RESP);
eth_broadcast_addr(mgmt->da);
memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
mgmt->u.beacon.capab_info = cpu_to_le16(capability);
pos = (u8 *)mgmt + offsetof(struct ieee80211_mgmt, u.beacon.variable);
*pos++ = WLAN_EID_SSID;
*pos++ = ifibss->ssid_len;
memcpy(pos, ifibss->ssid, ifibss->ssid_len);
pos += ifibss->ssid_len;
sband = local->hw.wiphy->bands[chandef->chan->band];
rate_flags = ieee80211_chandef_rate_flags(chandef);
shift = ieee80211_chandef_get_shift(chandef);
rates_n = 0;
if (have_higher_than_11mbit)
*have_higher_than_11mbit = false;
for (i = 0; i < sband->n_bitrates; i++) {
if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
continue;
if (sband->bitrates[i].bitrate > 110 &&
have_higher_than_11mbit)
*have_higher_than_11mbit = true;
rates |= BIT(i);
rates_n++;
}
*pos++ = WLAN_EID_SUPP_RATES;
*pos++ = min_t(int, 8, rates_n);
for (ri = 0; ri < sband->n_bitrates; ri++) {
int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate,
5 * (1 << shift));
u8 basic = 0;
if (!(rates & BIT(ri)))
continue;
if (basic_rates & BIT(ri))
basic = 0x80;
*pos++ = basic | (u8) rate;
if (++rates_added == 8) {
ri++; /* continue at next rate for EXT_SUPP_RATES */
break;
}
}
if (sband->band == IEEE80211_BAND_2GHZ) {
*pos++ = WLAN_EID_DS_PARAMS;
*pos++ = 1;
*pos++ = ieee80211_frequency_to_channel(
chandef->chan->center_freq);
}
*pos++ = WLAN_EID_IBSS_PARAMS;
*pos++ = 2;
/* FIX: set ATIM window based on scan results */
*pos++ = 0;
*pos++ = 0;
if (csa_settings) {
*pos++ = WLAN_EID_CHANNEL_SWITCH;
*pos++ = 3;
*pos++ = csa_settings->block_tx ? 1 : 0;
*pos++ = ieee80211_frequency_to_channel(
csa_settings->chandef.chan->center_freq);
sdata->csa_counter_offset_beacon = (pos - presp->head);
*pos++ = csa_settings->count;
}
/* put the remaining rates in WLAN_EID_EXT_SUPP_RATES */
if (rates_n > 8) {
*pos++ = WLAN_EID_EXT_SUPP_RATES;
*pos++ = rates_n - 8;
for (; ri < sband->n_bitrates; ri++) {
int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate,
5 * (1 << shift));
u8 basic = 0;
if (!(rates & BIT(ri)))
continue;
if (basic_rates & BIT(ri))
basic = 0x80;
*pos++ = basic | (u8) rate;
}
}
if (ifibss->ie_len) {
memcpy(pos, ifibss->ie, ifibss->ie_len);
pos += ifibss->ie_len;
}
/* add HT capability and information IEs */
if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT &&
chandef->width != NL80211_CHAN_WIDTH_5 &&
chandef->width != NL80211_CHAN_WIDTH_10 &&
sband->ht_cap.ht_supported) {
struct ieee80211_sta_ht_cap ht_cap;
memcpy(&ht_cap, &sband->ht_cap, sizeof(ht_cap));
ieee80211_apply_htcap_overrides(sdata, &ht_cap);
pos = ieee80211_ie_build_ht_cap(pos, &ht_cap, ht_cap.cap);
/*
* Note: According to 802.11n-2009 9.13.3.1, HT Protection
* field and RIFS Mode are reserved in IBSS mode, therefore
* keep them at 0
*/
pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
chandef, 0);
}
if (local->hw.queues >= IEEE80211_NUM_ACS) {
*pos++ = WLAN_EID_VENDOR_SPECIFIC;
*pos++ = 7; /* len */
*pos++ = 0x00; /* Microsoft OUI 00:50:F2 */
*pos++ = 0x50;
*pos++ = 0xf2;
*pos++ = 2; /* WME */
*pos++ = 0; /* WME info */
*pos++ = 1; /* WME ver */
*pos++ = 0; /* U-APSD no in use */
}
presp->head_len = pos - presp->head;
if (WARN_ON(presp->head_len > frame_len))
goto error;
return presp;
error:
kfree(presp);
return NULL;
}
static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
const u8 *bssid, const int beacon_int,
struct cfg80211_chan_def *req_chandef,
const u32 basic_rates,
const u16 capability, u64 tsf,
bool creator)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
struct ieee80211_mgmt *mgmt;
struct cfg80211_bss *bss;
u32 bss_change;
struct cfg80211_chan_def chandef;
struct ieee80211_channel *chan;
struct beacon_data *presp;
enum nl80211_bss_scan_width scan_width;
bool have_higher_than_11mbit;
bool radar_required = false;
int err;
sdata_assert_lock(sdata);
/* Reset own TSF to allow time synchronization work. */
drv_reset_tsf(local, sdata);
if (!ether_addr_equal(ifibss->bssid, bssid))
sta_info_flush(sdata);
/* if merging, indicate to driver that we leave the old IBSS */
if (sdata->vif.bss_conf.ibss_joined) {
sdata->vif.bss_conf.ibss_joined = false;
sdata->vif.bss_conf.ibss_creator = false;
sdata->vif.bss_conf.enable_beacon = false;
netif_carrier_off(sdata->dev);
ieee80211_bss_info_change_notify(sdata,
BSS_CHANGED_IBSS |
BSS_CHANGED_BEACON_ENABLED);
drv_leave_ibss(local, sdata);
}
presp = rcu_dereference_protected(ifibss->presp,
lockdep_is_held(&sdata->wdev.mtx));
rcu_assign_pointer(ifibss->presp, NULL);
if (presp)
kfree_rcu(presp, rcu_head);
sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
/* make a copy of the chandef, it could be modified below. */
chandef = *req_chandef;
chan = chandef.chan;
if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef)) {
if (chandef.width == NL80211_CHAN_WIDTH_5 ||
chandef.width == NL80211_CHAN_WIDTH_10 ||
chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
chandef.width == NL80211_CHAN_WIDTH_20) {
sdata_info(sdata,
"Failed to join IBSS, beacons forbidden\n");
return;
}
chandef.width = NL80211_CHAN_WIDTH_20;
chandef.center_freq1 = chan->center_freq;
/* check again for downgraded chandef */
if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef)) {
sdata_info(sdata,
"Failed to join IBSS, beacons forbidden\n");
return;
}
}
err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
&chandef);
if (err < 0) {
sdata_info(sdata,
"Failed to join IBSS, invalid chandef\n");
return;
}
if (err > 0) {
if (!ifibss->userspace_handles_dfs) {
sdata_info(sdata,
"Failed to join IBSS, DFS channel without control program\n");
return;
}
radar_required = true;
}
mutex_lock(&local->mtx);
if (ieee80211_vif_use_channel(sdata, &chandef,
ifibss->fixed_channel ?
IEEE80211_CHANCTX_SHARED :
IEEE80211_CHANCTX_EXCLUSIVE)) {
sdata_info(sdata, "Failed to join IBSS, no channel context\n");
mutex_unlock(&local->mtx);
return;
}
sdata->radar_required = radar_required;
mutex_unlock(&local->mtx);
memcpy(ifibss->bssid, bssid, ETH_ALEN);
presp = ieee80211_ibss_build_presp(sdata, beacon_int, basic_rates,
capability, tsf, &chandef,
&have_higher_than_11mbit, NULL);
if (!presp)
return;
rcu_assign_pointer(ifibss->presp, presp);
mgmt = (void *)presp->head;
sdata->vif.bss_conf.enable_beacon = true;
sdata->vif.bss_conf.beacon_int = beacon_int;
sdata->vif.bss_conf.basic_rates = basic_rates;
sdata->vif.bss_conf.ssid_len = ifibss->ssid_len;
memcpy(sdata->vif.bss_conf.ssid, ifibss->ssid, ifibss->ssid_len);
bss_change = BSS_CHANGED_BEACON_INT;
bss_change |= ieee80211_reset_erp_info(sdata);
bss_change |= BSS_CHANGED_BSSID;
bss_change |= BSS_CHANGED_BEACON;
bss_change |= BSS_CHANGED_BEACON_ENABLED;
bss_change |= BSS_CHANGED_BASIC_RATES;
bss_change |= BSS_CHANGED_HT;
bss_change |= BSS_CHANGED_IBSS;
bss_change |= BSS_CHANGED_SSID;
/*
* In 5 GHz/802.11a, we can always use short slot time.
* (IEEE 802.11-2012 18.3.8.7)
*
* In 2.4GHz, we must always use long slots in IBSS for compatibility
* reasons.
* (IEEE 802.11-2012 19.4.5)
*
* HT follows these specifications (IEEE 802.11-2012 20.3.18)
*/
sdata->vif.bss_conf.use_short_slot = chan->band == IEEE80211_BAND_5GHZ;
bss_change |= BSS_CHANGED_ERP_SLOT;
/* cf. IEEE 802.11 9.2.12 */
if (chan->band == IEEE80211_BAND_2GHZ && have_higher_than_11mbit)
sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
else
sdata->flags &= ~IEEE80211_SDATA_OPERATING_GMODE;
ieee80211_set_wmm_default(sdata, true);
sdata->vif.bss_conf.ibss_joined = true;
sdata->vif.bss_conf.ibss_creator = creator;
err = drv_join_ibss(local, sdata);
if (err) {
sdata->vif.bss_conf.ibss_joined = false;
sdata->vif.bss_conf.ibss_creator = false;
sdata->vif.bss_conf.enable_beacon = false;
sdata->vif.bss_conf.ssid_len = 0;
RCU_INIT_POINTER(ifibss->presp, NULL);
kfree_rcu(presp, rcu_head);
mutex_lock(&local->mtx);
ieee80211_vif_release_channel(sdata);
mutex_unlock(&local->mtx);
sdata_info(sdata, "Failed to join IBSS, driver failure: %d\n",
err);
return;
}
ieee80211_bss_info_change_notify(sdata, bss_change);
ifibss->state = IEEE80211_IBSS_MLME_JOINED;
mod_timer(&ifibss->timer,
round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
scan_width = cfg80211_chandef_to_scan_width(&chandef);
bss = cfg80211_inform_bss_width_frame(local->hw.wiphy, chan,
scan_width, mgmt,
presp->head_len, 0, GFP_KERNEL);
cfg80211_put_bss(local->hw.wiphy, bss);
netif_carrier_on(sdata->dev);
cfg80211_ibss_joined(sdata->dev, ifibss->bssid, chan, GFP_KERNEL);
}
static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
struct ieee80211_bss *bss)
{
struct cfg80211_bss *cbss =
container_of((void *)bss, struct cfg80211_bss, priv);
struct ieee80211_supported_band *sband;
struct cfg80211_chan_def chandef;
u32 basic_rates;
int i, j;
u16 beacon_int = cbss->beacon_interval;
const struct cfg80211_bss_ies *ies;
enum nl80211_channel_type chan_type;
u64 tsf;
u32 rate_flags;
int shift;
sdata_assert_lock(sdata);
if (beacon_int < 10)
beacon_int = 10;
switch (sdata->u.ibss.chandef.width) {
case NL80211_CHAN_WIDTH_20_NOHT:
case NL80211_CHAN_WIDTH_20:
case NL80211_CHAN_WIDTH_40:
chan_type = cfg80211_get_chandef_type(&sdata->u.ibss.chandef);
cfg80211_chandef_create(&chandef, cbss->channel, chan_type);
break;
case NL80211_CHAN_WIDTH_5:
case NL80211_CHAN_WIDTH_10:
cfg80211_chandef_create(&chandef, cbss->channel,
NL80211_CHAN_WIDTH_20_NOHT);
chandef.width = sdata->u.ibss.chandef.width;
break;
default:
/* fall back to 20 MHz for unsupported modes */
cfg80211_chandef_create(&chandef, cbss->channel,
NL80211_CHAN_WIDTH_20_NOHT);
break;
}
sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
rate_flags = ieee80211_chandef_rate_flags(&sdata->u.ibss.chandef);
shift = ieee80211_vif_get_shift(&sdata->vif);
basic_rates = 0;
for (i = 0; i < bss->supp_rates_len; i++) {
int rate = bss->supp_rates[i] & 0x7f;
bool is_basic = !!(bss->supp_rates[i] & 0x80);
for (j = 0; j < sband->n_bitrates; j++) {
int brate;
if ((rate_flags & sband->bitrates[j].flags)
!= rate_flags)
continue;
brate = DIV_ROUND_UP(sband->bitrates[j].bitrate,
5 * (1 << shift));
if (brate == rate) {
if (is_basic)
basic_rates |= BIT(j);
break;
}
}
}
rcu_read_lock();
ies = rcu_dereference(cbss->ies);
tsf = ies->tsf;
rcu_read_unlock();
__ieee80211_sta_join_ibss(sdata, cbss->bssid,
beacon_int,
&chandef,
basic_rates,
cbss->capability,
tsf, false);
}
int ieee80211_ibss_csa_beacon(struct ieee80211_sub_if_data *sdata,
struct cfg80211_csa_settings *csa_settings)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct beacon_data *presp, *old_presp;
struct cfg80211_bss *cbss;
const struct cfg80211_bss_ies *ies;
u16 capability;
u64 tsf;
int ret = 0;
sdata_assert_lock(sdata);
capability = WLAN_CAPABILITY_IBSS;
if (ifibss->privacy)
capability |= WLAN_CAPABILITY_PRIVACY;
cbss = cfg80211_get_bss(sdata->local->hw.wiphy, ifibss->chandef.chan,
ifibss->bssid, ifibss->ssid,
ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
WLAN_CAPABILITY_PRIVACY,
capability);
if (WARN_ON(!cbss)) {
ret = -EINVAL;
goto out;
}
rcu_read_lock();
ies = rcu_dereference(cbss->ies);
tsf = ies->tsf;
rcu_read_unlock();
cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
old_presp = rcu_dereference_protected(ifibss->presp,
lockdep_is_held(&sdata->wdev.mtx));
presp = ieee80211_ibss_build_presp(sdata,
sdata->vif.bss_conf.beacon_int,
sdata->vif.bss_conf.basic_rates,
capability, tsf, &ifibss->chandef,
NULL, csa_settings);
if (!presp) {
ret = -ENOMEM;
goto out;
}
rcu_assign_pointer(ifibss->presp, presp);
if (old_presp)
kfree_rcu(old_presp, rcu_head);
return BSS_CHANGED_BEACON;
out:
return ret;
}
int ieee80211_ibss_finish_csa(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct cfg80211_bss *cbss;
int err, changed = 0;
u16 capability;
sdata_assert_lock(sdata);
/* update cfg80211 bss information with the new channel */
if (!is_zero_ether_addr(ifibss->bssid)) {
capability = WLAN_CAPABILITY_IBSS;
if (ifibss->privacy)
capability |= WLAN_CAPABILITY_PRIVACY;
cbss = cfg80211_get_bss(sdata->local->hw.wiphy,
ifibss->chandef.chan,
ifibss->bssid, ifibss->ssid,
ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
WLAN_CAPABILITY_PRIVACY,
capability);
/* XXX: should not really modify cfg80211 data */
if (cbss) {
cbss->channel = sdata->csa_chandef.chan;
cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
}
}
ifibss->chandef = sdata->csa_chandef;
/* generate the beacon */
err = ieee80211_ibss_csa_beacon(sdata, NULL);
if (err < 0)
return err;
changed |= err;
return changed;
}
void ieee80211_ibss_stop(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
cancel_work_sync(&ifibss->csa_connection_drop_work);
}
static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta)
__acquires(RCU)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
u8 addr[ETH_ALEN];
memcpy(addr, sta->sta.addr, ETH_ALEN);
ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
/* authorize the station only if the network is not RSN protected. If
* not wait for the userspace to authorize it */
if (!sta->sdata->u.ibss.control_port)
sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
rate_control_rate_init(sta);
/* If it fails, maybe we raced another insertion? */
if (sta_info_insert_rcu(sta))
return sta_info_get(sdata, addr);
return sta;
}
static struct sta_info *
ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, const u8 *bssid,
const u8 *addr, u32 supp_rates)
__acquires(RCU)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
struct ieee80211_chanctx_conf *chanctx_conf;
struct ieee80211_supported_band *sband;
enum nl80211_bss_scan_width scan_width;
int band;
/*
* XXX: Consider removing the least recently used entry and
* allow new one to be added.
*/
if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
sdata->name, addr);
rcu_read_lock();
return NULL;
}
if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
rcu_read_lock();
return NULL;
}
if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
rcu_read_lock();
return NULL;
}
rcu_read_lock();
chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
if (WARN_ON_ONCE(!chanctx_conf))
return NULL;
band = chanctx_conf->def.chan->band;
scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
rcu_read_unlock();
sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
if (!sta) {
rcu_read_lock();
return NULL;
}
sta->last_rx = jiffies;
/* make sure mandatory rates are always added */
sband = local->hw.wiphy->bands[band];
sta->sta.supp_rates[band] = supp_rates |
ieee80211_mandatory_rates(sband, scan_width);
return ieee80211_ibss_finish_sta(sta);
}
static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_local *local = sdata->local;
int active = 0;
struct sta_info *sta;
sdata_assert_lock(sdata);
rcu_read_lock();
list_for_each_entry_rcu(sta, &local->sta_list, list) {
if (sta->sdata == sdata &&
time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
jiffies)) {
active++;
break;
}
}
rcu_read_unlock();
return active;
}
static void ieee80211_ibss_disconnect(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
struct cfg80211_bss *cbss;
struct beacon_data *presp;
struct sta_info *sta;
u16 capability;
if (!is_zero_ether_addr(ifibss->bssid)) {
capability = WLAN_CAPABILITY_IBSS;
if (ifibss->privacy)
capability |= WLAN_CAPABILITY_PRIVACY;
cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->chandef.chan,
ifibss->bssid, ifibss->ssid,
ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
WLAN_CAPABILITY_PRIVACY,
capability);
if (cbss) {
cfg80211_unlink_bss(local->hw.wiphy, cbss);
cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
}
}
ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
sta_info_flush(sdata);
spin_lock_bh(&ifibss->incomplete_lock);
while (!list_empty(&ifibss->incomplete_stations)) {
sta = list_first_entry(&ifibss->incomplete_stations,
struct sta_info, list);
list_del(&sta->list);
spin_unlock_bh(&ifibss->incomplete_lock);
sta_info_free(local, sta);
spin_lock_bh(&ifibss->incomplete_lock);
}
spin_unlock_bh(&ifibss->incomplete_lock);
netif_carrier_off(sdata->dev);
sdata->vif.bss_conf.ibss_joined = false;
sdata->vif.bss_conf.ibss_creator = false;
sdata->vif.bss_conf.enable_beacon = false;
sdata->vif.bss_conf.ssid_len = 0;
/* remove beacon */
presp = rcu_dereference_protected(ifibss->presp,
lockdep_is_held(&sdata->wdev.mtx));
RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
if (presp)
kfree_rcu(presp, rcu_head);
clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
BSS_CHANGED_IBSS);
drv_leave_ibss(local, sdata);
mutex_lock(&local->mtx);
ieee80211_vif_release_channel(sdata);
mutex_unlock(&local->mtx);
}
static void ieee80211_csa_connection_drop_work(struct work_struct *work)
{
struct ieee80211_sub_if_data *sdata =
container_of(work, struct ieee80211_sub_if_data,
u.ibss.csa_connection_drop_work);
sdata_lock(sdata);
ieee80211_ibss_disconnect(sdata);
synchronize_rcu();
skb_queue_purge(&sdata->skb_queue);
/* trigger a scan to find another IBSS network to join */
ieee80211_queue_work(&sdata->local->hw, &sdata->work);
sdata_unlock(sdata);
}
static void ieee80211_ibss_csa_mark_radar(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
int err;
/* if the current channel is a DFS channel, mark the channel as
* unavailable.
*/
err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
&ifibss->chandef);
if (err > 0)
cfg80211_radar_event(sdata->local->hw.wiphy, &ifibss->chandef,
GFP_ATOMIC);
}
static bool
ieee80211_ibss_process_chanswitch(struct ieee80211_sub_if_data *sdata,
struct ieee802_11_elems *elems,
bool beacon)
{
struct cfg80211_csa_settings params;
struct ieee80211_csa_ie csa_ie;
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
enum nl80211_channel_type ch_type;
int err;
u32 sta_flags;
sdata_assert_lock(sdata);
sta_flags = IEEE80211_STA_DISABLE_VHT;
switch (ifibss->chandef.width) {
case NL80211_CHAN_WIDTH_5:
case NL80211_CHAN_WIDTH_10:
case NL80211_CHAN_WIDTH_20_NOHT:
sta_flags |= IEEE80211_STA_DISABLE_HT;
/* fall through */
case NL80211_CHAN_WIDTH_20:
sta_flags |= IEEE80211_STA_DISABLE_40MHZ;
break;
default:
break;
}
memset(&params, 0, sizeof(params));
memset(&csa_ie, 0, sizeof(csa_ie));
err = ieee80211_parse_ch_switch_ie(sdata, elems, beacon,
ifibss->chandef.chan->band,
sta_flags, ifibss->bssid, &csa_ie);
/* can't switch to destination channel, fail */
if (err < 0)
goto disconnect;
/* did not contain a CSA */
if (err)
return false;
/* channel switch is not supported, disconnect */
if (!(sdata->local->hw.wiphy->flags & WIPHY_FLAG_HAS_CHANNEL_SWITCH))
goto disconnect;
params.count = csa_ie.count;
params.chandef = csa_ie.chandef;
switch (ifibss->chandef.width) {
case NL80211_CHAN_WIDTH_20_NOHT:
case NL80211_CHAN_WIDTH_20:
case NL80211_CHAN_WIDTH_40:
/* keep our current HT mode (HT20/HT40+/HT40-), even if
* another mode has been announced. The mode is not adopted
* within the beacon while doing CSA and we should therefore
* keep the mode which we announce.
*/
ch_type = cfg80211_get_chandef_type(&ifibss->chandef);
cfg80211_chandef_create(&params.chandef, params.chandef.chan,
ch_type);
break;
case NL80211_CHAN_WIDTH_5:
case NL80211_CHAN_WIDTH_10:
if (params.chandef.width != ifibss->chandef.width) {
sdata_info(sdata,
"IBSS %pM received channel switch from incompatible channel width (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
ifibss->bssid,
params.chandef.chan->center_freq,
params.chandef.width,
params.chandef.center_freq1,
params.chandef.center_freq2);
goto disconnect;
}
break;
default:
/* should not happen, sta_flags should prevent VHT modes. */
WARN_ON(1);
goto disconnect;
}
if (!cfg80211_reg_can_beacon(sdata->local->hw.wiphy, &params.chandef)) {
sdata_info(sdata,
"IBSS %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
ifibss->bssid,
params.chandef.chan->center_freq,
params.chandef.width,
params.chandef.center_freq1,
params.chandef.center_freq2);
goto disconnect;
}
err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
&params.chandef);
if (err < 0)
goto disconnect;
if (err) {
/* IBSS-DFS only allowed with a control program */
if (!ifibss->userspace_handles_dfs)
goto disconnect;
params.radar_required = true;
}
if (cfg80211_chandef_identical(&params.chandef,
&sdata->vif.bss_conf.chandef)) {
ibss_dbg(sdata,
"received csa with an identical chandef, ignoring\n");
return true;
}
/* all checks done, now perform the channel switch. */
ibss_dbg(sdata,
"received channel switch announcement to go to channel %d MHz\n",
params.chandef.chan->center_freq);
params.block_tx = !!csa_ie.mode;
if (ieee80211_channel_switch(sdata->local->hw.wiphy, sdata->dev,
&params))
goto disconnect;
ieee80211_ibss_csa_mark_radar(sdata);
return true;
disconnect:
ibss_dbg(sdata, "Can't handle channel switch, disconnect\n");
ieee80211_queue_work(&sdata->local->hw,
&ifibss->csa_connection_drop_work);
ieee80211_ibss_csa_mark_radar(sdata);
return true;
}
static void
ieee80211_rx_mgmt_spectrum_mgmt(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt, size_t len,
struct ieee80211_rx_status *rx_status,
struct ieee802_11_elems *elems)
{
int required_len;
if (len < IEEE80211_MIN_ACTION_SIZE + 1)
return;
/* CSA is the only action we handle for now */
if (mgmt->u.action.u.measurement.action_code !=
WLAN_ACTION_SPCT_CHL_SWITCH)
return;
required_len = IEEE80211_MIN_ACTION_SIZE +
sizeof(mgmt->u.action.u.chan_switch);
if (len < required_len)
return;
if (!sdata->vif.csa_active)
ieee80211_ibss_process_chanswitch(sdata, elems, false);
}
static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
size_t len)
{
u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code);
if (len < IEEE80211_DEAUTH_FRAME_LEN)
return;
ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n",
mgmt->sa, mgmt->da, mgmt->bssid, reason);
sta_info_destroy_addr(sdata, mgmt->sa);
}
static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
size_t len)
{
u16 auth_alg, auth_transaction;
sdata_assert_lock(sdata);
if (len < 24 + 6)
return;
auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
ibss_dbg(sdata,
"RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n",
mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction);
if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
return;
/*
* IEEE 802.11 standard does not require authentication in IBSS
* networks and most implementations do not seem to use it.
* However, try to reply to authentication attempts if someone
* has actually implemented this.
*/
ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0,
mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0, 0);
}
static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt, size_t len,
struct ieee80211_rx_status *rx_status,
struct ieee802_11_elems *elems)
{
struct ieee80211_local *local = sdata->local;
struct cfg80211_bss *cbss;
struct ieee80211_bss *bss;
struct sta_info *sta;
struct ieee80211_channel *channel;
u64 beacon_timestamp, rx_timestamp;
u32 supp_rates = 0;
enum ieee80211_band band = rx_status->band;
enum nl80211_bss_scan_width scan_width;
struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
bool rates_updated = false;
channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
if (!channel)
return;
if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) {
rcu_read_lock();
sta = sta_info_get(sdata, mgmt->sa);
if (elems->supp_rates) {
supp_rates = ieee80211_sta_get_rates(sdata, elems,
band, NULL);
if (sta) {
u32 prev_rates;
prev_rates = sta->sta.supp_rates[band];
/* make sure mandatory rates are always added */
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;
sta->sta.supp_rates[band] = supp_rates |
ieee80211_mandatory_rates(sband,
scan_width);
if (sta->sta.supp_rates[band] != prev_rates) {
ibss_dbg(sdata,
"updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n",
sta->sta.addr, prev_rates,
sta->sta.supp_rates[band]);
rates_updated = true;
}
} else {
rcu_read_unlock();
sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
mgmt->sa, supp_rates);
}
}
if (sta && elems->wmm_info)
set_sta_flag(sta, WLAN_STA_WME);
if (sta && elems->ht_operation && elems->ht_cap_elem &&
sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_5 &&
sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_10) {
/* we both use HT */
struct ieee80211_ht_cap htcap_ie;
struct cfg80211_chan_def chandef;
ieee80211_ht_oper_to_chandef(channel,
elems->ht_operation,
&chandef);
memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie));
/*
* fall back to HT20 if we don't use or use
* the other extension channel
*/
if (chandef.center_freq1 !=
sdata->u.ibss.chandef.center_freq1)
htcap_ie.cap_info &=
cpu_to_le16(~IEEE80211_HT_CAP_SUP_WIDTH_20_40);
rates_updated |= ieee80211_ht_cap_ie_to_sta_ht_cap(
sdata, sband, &htcap_ie, sta);
}
if (sta && rates_updated) {
drv_sta_rc_update(local, sdata, &sta->sta,
IEEE80211_RC_SUPP_RATES_CHANGED);
rate_control_rate_init(sta);
}
rcu_read_unlock();
}
bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
channel);
if (!bss)
return;
cbss = container_of((void *)bss, struct cfg80211_bss, priv);
/* same for beacon and probe response */
beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
/* check if we need to merge IBSS */
/* not an IBSS */
if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
goto put_bss;
/* different channel */
if (sdata->u.ibss.fixed_channel &&
sdata->u.ibss.chandef.chan != cbss->channel)
goto put_bss;
/* different SSID */
if (elems->ssid_len != sdata->u.ibss.ssid_len ||
memcmp(elems->ssid, sdata->u.ibss.ssid,
sdata->u.ibss.ssid_len))
goto put_bss;
/* process channel switch */
if (sdata->vif.csa_active ||
ieee80211_ibss_process_chanswitch(sdata, elems, true))
goto put_bss;
/* same BSSID */
if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
goto put_bss;
/* we use a fixed BSSID */
if (sdata->u.ibss.fixed_bssid)
goto put_bss;
if (ieee80211_have_rx_timestamp(rx_status)) {
/* time when timestamp field was received */
rx_timestamp =
ieee80211_calculate_rx_timestamp(local, rx_status,
len + FCS_LEN, 24);
} else {
/*
* second best option: get current TSF
* (will return -1 if not supported)
*/
rx_timestamp = drv_get_tsf(local, sdata);
}
ibss_dbg(sdata,
"RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
mgmt->sa, mgmt->bssid,
(unsigned long long)rx_timestamp,
(unsigned long long)beacon_timestamp,
(unsigned long long)(rx_timestamp - beacon_timestamp),
jiffies);
if (beacon_timestamp > rx_timestamp) {
ibss_dbg(sdata,
"beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
mgmt->bssid);
ieee80211_sta_join_ibss(sdata, bss);
supp_rates = ieee80211_sta_get_rates(sdata, elems, band, NULL);
ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
supp_rates);
rcu_read_unlock();
}
put_bss:
ieee80211_rx_bss_put(local, bss);
}
void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
const u8 *bssid, const u8 *addr,
u32 supp_rates)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
struct ieee80211_chanctx_conf *chanctx_conf;
struct ieee80211_supported_band *sband;
enum nl80211_bss_scan_width scan_width;
int band;
/*
* XXX: Consider removing the least recently used entry and
* allow new one to be added.
*/
if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
sdata->name, addr);
return;
}
if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
return;
if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
return;
rcu_read_lock();
chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
if (WARN_ON_ONCE(!chanctx_conf)) {
rcu_read_unlock();
return;
}
band = chanctx_conf->def.chan->band;
scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
rcu_read_unlock();
sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
if (!sta)
return;
sta->last_rx = jiffies;
/* make sure mandatory rates are always added */
sband = local->hw.wiphy->bands[band];
sta->sta.supp_rates[band] = supp_rates |
ieee80211_mandatory_rates(sband, scan_width);
spin_lock(&ifibss->incomplete_lock);
list_add(&sta->list, &ifibss->incomplete_stations);
spin_unlock(&ifibss->incomplete_lock);
ieee80211_queue_work(&local->hw, &sdata->work);
}
static void ieee80211_ibss_sta_expire(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_local *local = sdata->local;
struct sta_info *sta, *tmp;
unsigned long exp_time = IEEE80211_IBSS_INACTIVITY_LIMIT;
unsigned long exp_rsn_time = IEEE80211_IBSS_RSN_INACTIVITY_LIMIT;
mutex_lock(&local->sta_mtx);
list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
if (sdata != sta->sdata)
continue;
if (time_after(jiffies, sta->last_rx + exp_time) ||
(time_after(jiffies, sta->last_rx + exp_rsn_time) &&
sta->sta_state != IEEE80211_STA_AUTHORIZED)) {
sta_dbg(sta->sdata, "expiring inactive %sSTA %pM\n",
sta->sta_state != IEEE80211_STA_AUTHORIZED ?
"not authorized " : "", sta->sta.addr);
WARN_ON(__sta_info_destroy(sta));
}
}
mutex_unlock(&local->sta_mtx);
}
/*
* This function is called with state == IEEE80211_IBSS_MLME_JOINED
*/
static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
enum nl80211_bss_scan_width scan_width;
sdata_assert_lock(sdata);
mod_timer(&ifibss->timer,
round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
ieee80211_ibss_sta_expire(sdata);
if (time_before(jiffies, ifibss->last_scan_completed +
IEEE80211_IBSS_MERGE_INTERVAL))
return;
if (ieee80211_sta_active_ibss(sdata))
return;
if (ifibss->fixed_channel)
return;
sdata_info(sdata,
"No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
NULL, scan_width);
}
static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
u8 bssid[ETH_ALEN];
u16 capability;
int i;
sdata_assert_lock(sdata);
if (ifibss->fixed_bssid) {
memcpy(bssid, ifibss->bssid, ETH_ALEN);
} else {
/* Generate random, not broadcast, locally administered BSSID. Mix in
* own MAC address to make sure that devices that do not have proper
* random number generator get different BSSID. */
get_random_bytes(bssid, ETH_ALEN);
for (i = 0; i < ETH_ALEN; i++)
bssid[i] ^= sdata->vif.addr[i];
bssid[0] &= ~0x01;
bssid[0] |= 0x02;
}
sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);
capability = WLAN_CAPABILITY_IBSS;
if (ifibss->privacy)
capability |= WLAN_CAPABILITY_PRIVACY;
else
sdata->drop_unencrypted = 0;
__ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
&ifibss->chandef, ifibss->basic_rates,
capability, 0, true);
}
/*
* This function is called with state == IEEE80211_IBSS_MLME_SEARCH
*/
static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
struct cfg80211_bss *cbss;
struct ieee80211_channel *chan = NULL;
const u8 *bssid = NULL;
enum nl80211_bss_scan_width scan_width;
int active_ibss;
u16 capability;
sdata_assert_lock(sdata);
active_ibss = ieee80211_sta_active_ibss(sdata);
ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);
if (active_ibss)
return;
capability = WLAN_CAPABILITY_IBSS;
if (ifibss->privacy)
capability |= WLAN_CAPABILITY_PRIVACY;
if (ifibss->fixed_bssid)
bssid = ifibss->bssid;
if (ifibss->fixed_channel)
chan = ifibss->chandef.chan;
if (!is_zero_ether_addr(ifibss->bssid))
bssid = ifibss->bssid;
cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
ifibss->ssid, ifibss->ssid_len,
WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
capability);
if (cbss) {
struct ieee80211_bss *bss;
bss = (void *)cbss->priv;
ibss_dbg(sdata,
"sta_find_ibss: selected %pM current %pM\n",
cbss->bssid, ifibss->bssid);
sdata_info(sdata,
"Selected IBSS BSSID %pM based on configured SSID\n",
cbss->bssid);
ieee80211_sta_join_ibss(sdata, bss);
ieee80211_rx_bss_put(local, bss);
return;
}
/* if a fixed bssid and a fixed freq have been provided create the IBSS
* directly and do not waste time scanning
*/
if (ifibss->fixed_bssid && ifibss->fixed_channel) {
sdata_info(sdata, "Created IBSS using preconfigured BSSID %pM\n",
bssid);
ieee80211_sta_create_ibss(sdata);
return;
}
ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");
/* Selected IBSS not found in current scan results - try to scan */
if (time_after(jiffies, ifibss->last_scan_completed +
IEEE80211_SCAN_INTERVAL)) {
sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
ieee80211_request_ibss_scan(sdata, ifibss->ssid,
ifibss->ssid_len, chan,
scan_width);
} else {
int interval = IEEE80211_SCAN_INTERVAL;
if (time_after(jiffies, ifibss->ibss_join_req +
IEEE80211_IBSS_JOIN_TIMEOUT))
ieee80211_sta_create_ibss(sdata);
mod_timer(&ifibss->timer,
round_jiffies(jiffies + interval));
}
}
static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
struct sk_buff *req)
{
struct ieee80211_mgmt *mgmt = (void *)req->data;
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
int tx_last_beacon, len = req->len;
struct sk_buff *skb;
struct beacon_data *presp;
u8 *pos, *end;
sdata_assert_lock(sdata);
presp = rcu_dereference_protected(ifibss->presp,
lockdep_is_held(&sdata->wdev.mtx));
if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
len < 24 + 2 || !presp)
return;
tx_last_beacon = drv_tx_last_beacon(local);
ibss_dbg(sdata,
"RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n",
mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon);
if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
return;
if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
!is_broadcast_ether_addr(mgmt->bssid))
return;
end = ((u8 *) mgmt) + len;
pos = mgmt->u.probe_req.variable;
if (pos[0] != WLAN_EID_SSID ||
pos + 2 + pos[1] > end) {
ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
mgmt->sa);
return;
}
if (pos[1] != 0 &&
(pos[1] != ifibss->ssid_len ||
memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
/* Ignore ProbeReq for foreign SSID */
return;
}
/* Reply with ProbeResp */
skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
if (!skb)
return;
skb_reserve(skb, local->tx_headroom);
memcpy(skb_put(skb, presp->head_len), presp->head, presp->head_len);
memcpy(((struct ieee80211_mgmt *) skb->data)->da, mgmt->sa, ETH_ALEN);
ibss_dbg(sdata, "Sending ProbeResp to %pM\n", mgmt->sa);
IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
/* avoid excessive retries for probe request to wildcard SSIDs */
if (pos[1] == 0)
IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_NO_ACK;
ieee80211_tx_skb(sdata, skb);
}
static
void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt, size_t len,
struct ieee80211_rx_status *rx_status)
{
size_t baselen;
struct ieee802_11_elems elems;
BUILD_BUG_ON(offsetof(typeof(mgmt->u.probe_resp), variable) !=
offsetof(typeof(mgmt->u.beacon), variable));
/*
* either beacon or probe_resp but the variable field is at the
* same offset
*/
baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
if (baselen > len)
return;
ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
false, &elems);
ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems);
}
void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb)
{
struct ieee80211_rx_status *rx_status;
struct ieee80211_mgmt *mgmt;
u16 fc;
struct ieee802_11_elems elems;
int ies_len;
rx_status = IEEE80211_SKB_RXCB(skb);
mgmt = (struct ieee80211_mgmt *) skb->data;
fc = le16_to_cpu(mgmt->frame_control);
sdata_lock(sdata);
if (!sdata->u.ibss.ssid_len)
goto mgmt_out; /* not ready to merge yet */
switch (fc & IEEE80211_FCTL_STYPE) {
case IEEE80211_STYPE_PROBE_REQ:
ieee80211_rx_mgmt_probe_req(sdata, skb);
break;
case IEEE80211_STYPE_PROBE_RESP:
case IEEE80211_STYPE_BEACON:
ieee80211_rx_mgmt_probe_beacon(sdata, mgmt, skb->len,
rx_status);
break;
case IEEE80211_STYPE_AUTH:
ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
break;
case IEEE80211_STYPE_DEAUTH:
ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len);
break;
case IEEE80211_STYPE_ACTION:
switch (mgmt->u.action.category) {
case WLAN_CATEGORY_SPECTRUM_MGMT:
ies_len = skb->len -
offsetof(struct ieee80211_mgmt,
u.action.u.chan_switch.variable);
if (ies_len < 0)
break;
ieee802_11_parse_elems(
mgmt->u.action.u.chan_switch.variable,
ies_len, true, &elems);
if (elems.parse_error)
break;
ieee80211_rx_mgmt_spectrum_mgmt(sdata, mgmt, skb->len,
rx_status, &elems);
break;
}
}
mgmt_out:
sdata_unlock(sdata);
}
void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct sta_info *sta;
sdata_lock(sdata);
/*
* Work could be scheduled after scan or similar
* when we aren't even joined (or trying) with a
* network.
*/
if (!ifibss->ssid_len)
goto out;
spin_lock_bh(&ifibss->incomplete_lock);
while (!list_empty(&ifibss->incomplete_stations)) {
sta = list_first_entry(&ifibss->incomplete_stations,
struct sta_info, list);
list_del(&sta->list);
spin_unlock_bh(&ifibss->incomplete_lock);
ieee80211_ibss_finish_sta(sta);
rcu_read_unlock();
spin_lock_bh(&ifibss->incomplete_lock);
}
spin_unlock_bh(&ifibss->incomplete_lock);
switch (ifibss->state) {
case IEEE80211_IBSS_MLME_SEARCH:
ieee80211_sta_find_ibss(sdata);
break;
case IEEE80211_IBSS_MLME_JOINED:
ieee80211_sta_merge_ibss(sdata);
break;
default:
WARN_ON(1);
break;
}
out:
sdata_unlock(sdata);
}
static void ieee80211_ibss_timer(unsigned long data)
{
struct ieee80211_sub_if_data *sdata =
(struct ieee80211_sub_if_data *) data;
ieee80211_queue_work(&sdata->local->hw, &sdata->work);
}
void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
setup_timer(&ifibss->timer, ieee80211_ibss_timer,
(unsigned long) sdata);
INIT_LIST_HEAD(&ifibss->incomplete_stations);
spin_lock_init(&ifibss->incomplete_lock);
INIT_WORK(&ifibss->csa_connection_drop_work,
ieee80211_csa_connection_drop_work);
}
/* scan finished notification */
void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
{
struct ieee80211_sub_if_data *sdata;
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_ADHOC)
continue;
sdata->u.ibss.last_scan_completed = jiffies;
ieee80211_queue_work(&local->hw, &sdata->work);
}
mutex_unlock(&local->iflist_mtx);
}
int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
struct cfg80211_ibss_params *params)
{
u32 changed = 0;
u32 rate_flags;
struct ieee80211_supported_band *sband;
int i;
if (params->bssid) {
memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
sdata->u.ibss.fixed_bssid = true;
} else
sdata->u.ibss.fixed_bssid = false;
sdata->u.ibss.privacy = params->privacy;
sdata->u.ibss.control_port = params->control_port;
sdata->u.ibss.userspace_handles_dfs = params->userspace_handles_dfs;
sdata->u.ibss.basic_rates = params->basic_rates;
/* fix basic_rates if channel does not support these rates */
rate_flags = ieee80211_chandef_rate_flags(&params->chandef);
sband = sdata->local->hw.wiphy->bands[params->chandef.chan->band];
for (i = 0; i < sband->n_bitrates; i++) {
if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
sdata->u.ibss.basic_rates &= ~BIT(i);
}
memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
sizeof(params->mcast_rate));
sdata->vif.bss_conf.beacon_int = params->beacon_interval;
sdata->u.ibss.chandef = params->chandef;
sdata->u.ibss.fixed_channel = params->channel_fixed;
if (params->ie) {
sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
GFP_KERNEL);
if (sdata->u.ibss.ie)
sdata->u.ibss.ie_len = params->ie_len;
}
sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
sdata->u.ibss.ibss_join_req = jiffies;
memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len);
sdata->u.ibss.ssid_len = params->ssid_len;
memcpy(&sdata->u.ibss.ht_capa, &params->ht_capa,
sizeof(sdata->u.ibss.ht_capa));
memcpy(&sdata->u.ibss.ht_capa_mask, &params->ht_capa_mask,
sizeof(sdata->u.ibss.ht_capa_mask));
/*
* 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
* reserved, but an HT STA shall protect HT transmissions as though
* the HT Protection field were set to non-HT mixed mode.
*
* In an IBSS, the RIFS Mode field of the HT Operation element is
* also reserved, but an HT STA shall operate as though this field
* were set to 1.
*/
sdata->vif.bss_conf.ht_operation_mode |=
IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
| IEEE80211_HT_PARAM_RIFS_MODE;
changed |= BSS_CHANGED_HT;
ieee80211_bss_info_change_notify(sdata, changed);
sdata->smps_mode = IEEE80211_SMPS_OFF;
sdata->needed_rx_chains = sdata->local->rx_chains;
ieee80211_queue_work(&sdata->local->hw, &sdata->work);
return 0;
}
int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
ieee80211_ibss_disconnect(sdata);
ifibss->ssid_len = 0;
memset(ifibss->bssid, 0, ETH_ALEN);
/* remove beacon */
kfree(sdata->u.ibss.ie);
/* on the next join, re-program HT parameters */
memset(&ifibss->ht_capa, 0, sizeof(ifibss->ht_capa));
memset(&ifibss->ht_capa_mask, 0, sizeof(ifibss->ht_capa_mask));
synchronize_rcu();
skb_queue_purge(&sdata->skb_queue);
del_timer_sync(&sdata->u.ibss.timer);
return 0;
}
Reference in New Issue View Git Blame Copy Permalink