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ibss.c
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/*
* 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_MAX_STA_ENTRIES 128
static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
const u8 *bssid, const int beacon_int,
struct ieee80211_channel *chan,
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;
int rates, i;
struct sk_buff *skb;
struct ieee80211_mgmt *mgmt;
u8 *pos;
struct ieee80211_supported_band *sband;
struct cfg80211_bss *bss;
u32 bss_change;
u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
struct cfg80211_chan_def chandef;
lockdep_assert_held(&ifibss->mtx);
/* Reset own TSF to allow time synchronization work. */
drv_reset_tsf(local, sdata);
skb = ifibss->skb;
RCU_INIT_POINTER(ifibss->presp, NULL);
synchronize_rcu();
skb->data = skb->head;
skb->len = 0;
skb_reset_tail_pointer(skb);
skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
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;
netif_carrier_off(sdata->dev);
ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS);
}
sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
cfg80211_chandef_create(&chandef, chan, ifibss->channel_type);
if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef)) {
chandef.width = NL80211_CHAN_WIDTH_20;
chandef.center_freq1 = chan->center_freq;
}
ieee80211_vif_release_channel(sdata);
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");
return;
}
memcpy(ifibss->bssid, bssid, ETH_ALEN);
sband = local->hw.wiphy->bands[chan->band];
/* build supported rates array */
pos = supp_rates;
for (i = 0; i < sband->n_bitrates; i++) {
int rate = sband->bitrates[i].bitrate;
u8 basic = 0;
if (basic_rates & BIT(i))
basic = 0x80;
*pos++ = basic | (u8) (rate / 5);
}
/* Build IBSS probe response */
mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
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 = skb_put(skb, 2 + ifibss->ssid_len);
*pos++ = WLAN_EID_SSID;
*pos++ = ifibss->ssid_len;
memcpy(pos, ifibss->ssid, ifibss->ssid_len);
rates = sband->n_bitrates;
if (rates > 8)
rates = 8;
pos = skb_put(skb, 2 + rates);
*pos++ = WLAN_EID_SUPP_RATES;
*pos++ = rates;
memcpy(pos, supp_rates, rates);
if (sband->band == IEEE80211_BAND_2GHZ) {
pos = skb_put(skb, 2 + 1);
*pos++ = WLAN_EID_DS_PARAMS;
*pos++ = 1;
*pos++ = ieee80211_frequency_to_channel(chan->center_freq);
}
pos = skb_put(skb, 2 + 2);
*pos++ = WLAN_EID_IBSS_PARAMS;
*pos++ = 2;
/* FIX: set ATIM window based on scan results */
*pos++ = 0;
*pos++ = 0;
if (sband->n_bitrates > 8) {
rates = sband->n_bitrates - 8;
pos = skb_put(skb, 2 + rates);
*pos++ = WLAN_EID_EXT_SUPP_RATES;
*pos++ = rates;
memcpy(pos, &supp_rates[8], rates);
}
if (ifibss->ie_len)
memcpy(skb_put(skb, ifibss->ie_len),
ifibss->ie, ifibss->ie_len);
/* add HT capability and information IEs */
if (chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
sband->ht_cap.ht_supported) {
pos = skb_put(skb, 4 +
sizeof(struct ieee80211_ht_cap) +
sizeof(struct ieee80211_ht_operation));
pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap,
sband->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 = skb_put(skb, 9);
*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 */
}
rcu_assign_pointer(ifibss->presp, skb);
sdata->vif.bss_conf.beacon_int = beacon_int;
sdata->vif.bss_conf.basic_rates = basic_rates;
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;
/*
* 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;
sdata->vif.bss_conf.ibss_joined = true;
sdata->vif.bss_conf.ibss_creator = creator;
ieee80211_bss_info_change_notify(sdata, bss_change);
ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
ifibss->state = IEEE80211_IBSS_MLME_JOINED;
mod_timer(&ifibss->timer,
round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
bss = cfg80211_inform_bss_frame(local->hw.wiphy, chan,
mgmt, skb->len, 0, GFP_KERNEL);
cfg80211_put_bss(bss);
netif_carrier_on(sdata->dev);
cfg80211_ibss_joined(sdata->dev, ifibss->bssid, 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;
u32 basic_rates;
int i, j;
u16 beacon_int = cbss->beacon_interval;
lockdep_assert_held(&sdata->u.ibss.mtx);
if (beacon_int < 10)
beacon_int = 10;
sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
basic_rates = 0;
for (i = 0; i < bss->supp_rates_len; i++) {
int rate = (bss->supp_rates[i] & 0x7f) * 5;
bool is_basic = !!(bss->supp_rates[i] & 0x80);
for (j = 0; j < sband->n_bitrates; j++) {
if (sband->bitrates[j].bitrate == rate) {
if (is_basic)
basic_rates |= BIT(j);
break;
}
}
}
__ieee80211_sta_join_ibss(sdata, cbss->bssid,
beacon_int,
cbss->channel,
basic_rates,
cbss->capability,
cbss->tsf,
false);
}
static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta,
bool auth)
__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);
if (auth && !sdata->u.ibss.auth_frame_registrations) {
ibss_dbg(sdata,
"TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=1)\n",
sdata->vif.addr, addr, sdata->u.ibss.bssid);
ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, 0, NULL, 0,
addr, sdata->u.ibss.bssid, NULL, 0, 0);
}
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, bool auth)
__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;
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;
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 */
sta->sta.supp_rates[band] = supp_rates |
ieee80211_mandatory_rates(local, band);
return ieee80211_ibss_finish_sta(sta, auth);
}
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;
struct sta_info *sta;
u8 deauth_frame_buf[IEEE80211_DEAUTH_FRAME_LEN];
lockdep_assert_held(&sdata->u.ibss.mtx);
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;
sta_info_destroy_addr(sdata, mgmt->sa);
sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false);
rcu_read_unlock();
/*
* if we have any problem in allocating the new station, we reply with a
* DEAUTH frame to tell the other end that we had a problem
*/
if (!sta) {
ieee80211_send_deauth_disassoc(sdata, sdata->u.ibss.bssid,
IEEE80211_STYPE_DEAUTH,
WLAN_REASON_UNSPECIFIED, true,
deauth_frame_buf);
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);
}
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;
int freq;
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;
struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
bool rates_updated = false;
if (elems->ds_params && elems->ds_params_len == 1)
freq = ieee80211_channel_to_frequency(elems->ds_params[0],
band);
else
freq = rx_status->freq;
channel = ieee80211_get_channel(local->hw.wiphy, freq);
if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
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(local, elems,
band, NULL);
if (sta) {
u32 prev_rates;
prev_rates = sta->sta.supp_rates[band];
/* make sure mandatory rates are always added */
sta->sta.supp_rates[band] = supp_rates |
ieee80211_mandatory_rates(local, band);
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, true);
}
}
if (sta && elems->wmm_info)
set_sta_flag(sta, WLAN_STA_WME);
if (sta && elems->ht_operation && elems->ht_cap_elem &&
sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) {
/* we both use HT */
struct ieee80211_sta_ht_cap sta_ht_cap_new;
struct cfg80211_chan_def chandef;
ieee80211_ht_oper_to_chandef(channel,
elems->ht_operation,
&chandef);
ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
elems->ht_cap_elem,
&sta_ht_cap_new);
/*
* fall back to HT20 if we don't use or use
* the other extension channel
*/
if (chandef.width != NL80211_CHAN_WIDTH_40 ||
cfg80211_get_chandef_type(&chandef) !=
sdata->u.ibss.channel_type)
sta_ht_cap_new.cap &=
~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new,
sizeof(sta_ht_cap_new))) {
memcpy(&sta->sta.ht_cap, &sta_ht_cap_new,
sizeof(sta_ht_cap_new));
rates_updated = true;
}
}
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);
/* was just updated in ieee80211_bss_info_update */
beacon_timestamp = cbss->tsf;
/* check if we need to merge IBSS */
/* we use a fixed BSSID */
if (sdata->u.ibss.fixed_bssid)
goto put_bss;
/* not an IBSS */
if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
goto put_bss;
/* different channel */
if (sdata->u.ibss.fixed_channel &&
sdata->u.ibss.channel != 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;
/* same BSSID */
if (ether_addr_equal(cbss->bssid, sdata->u.ibss.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(local, elems, band, NULL);
ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
supp_rates, true);
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;
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;
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 */
sta->sta.supp_rates[band] = supp_rates |
ieee80211_mandatory_rates(local, band);
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 int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_local *local = sdata->local;
int active = 0;
struct sta_info *sta;
lockdep_assert_held(&sdata->u.ibss.mtx);
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;
}
/*
* 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;
lockdep_assert_held(&ifibss->mtx);
mod_timer(&ifibss->timer,
round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
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");
ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
NULL);
}
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;
lockdep_assert_held(&ifibss->mtx);
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->channel, 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;
int active_ibss;
u16 capability;
lockdep_assert_held(&ifibss->mtx);
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->channel;
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;
}
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");
ieee80211_request_ibss_scan(sdata, ifibss->ssid,
ifibss->ssid_len, chan);
} 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 ieee80211_mgmt *resp;
struct sk_buff *presp;
u8 *pos, *end;
lockdep_assert_held(&ifibss->mtx);
presp = rcu_dereference_protected(ifibss->presp,
lockdep_is_held(&ifibss->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 = skb_copy(presp, GFP_KERNEL);
if (!skb)
return;
resp = (struct ieee80211_mgmt *) skb->data;
memcpy(resp->da, mgmt->sa, ETH_ALEN);
ibss_dbg(sdata, "Sending ProbeResp to %pM\n", resp->da);
IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
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,
&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;
rx_status = IEEE80211_SKB_RXCB(skb);
mgmt = (struct ieee80211_mgmt *) skb->data;
fc = le16_to_cpu(mgmt->frame_control);
mutex_lock(&sdata->u.ibss.mtx);
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;
}
mgmt_out:
mutex_unlock(&sdata->u.ibss.mtx);
}
void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct sta_info *sta;
mutex_lock(&ifibss->mtx);
/*
* 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, true);
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:
mutex_unlock(&ifibss->mtx);
}
static void ieee80211_ibss_timer(unsigned long data)
{
struct ieee80211_sub_if_data *sdata =
(struct ieee80211_sub_if_data *) data;
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
if (local->quiescing) {
ifibss->timer_running = true;
return;
}
ieee80211_queue_work(&local->hw, &sdata->work);
}
#ifdef CONFIG_PM
void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)