diff options
Diffstat (limited to 'net/mac80211/ibss.c')
| -rw-r--r-- | net/mac80211/ibss.c | 1180 |
1 files changed, 1180 insertions, 0 deletions
diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c new file mode 100644 index 0000000..3052672 --- /dev/null +++ b/net/mac80211/ibss.c @@ -0,0 +1,1180 @@ +/* + * 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 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; + struct beacon_data *presp; + int frame_len; + + lockdep_assert_held(&ifibss->mtx); + + /* 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); + } + + presp = rcu_dereference_protected(ifibss->presp, + lockdep_is_held(&ifibss->mtx)); + rcu_assign_pointer(ifibss->presp, NULL); + if (presp) + kfree_rcu(presp, rcu_head); + + 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 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 */ + + 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; + + 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; + + rates = min_t(int, 8, sband->n_bitrates); + *pos++ = WLAN_EID_SUPP_RATES; + *pos++ = rates; + for (i = 0; i < rates; i++) { + int rate = sband->bitrates[i].bitrate; + u8 basic = 0; + if (basic_rates & BIT(i)) + basic = 0x80; + *pos++ = basic | (u8) (rate / 5); + } + + if (sband->band == IEEE80211_BAND_2GHZ) { + *pos++ = WLAN_EID_DS_PARAMS; + *pos++ = 1; + *pos++ = ieee80211_frequency_to_channel(chan->center_freq); + } + + *pos++ = WLAN_EID_IBSS_PARAMS; + *pos++ = 2; + /* FIX: set ATIM window based on scan results */ + *pos++ = 0; + *pos++ = 0; + + if (sband->n_bitrates > 8) { + *pos++ = WLAN_EID_EXT_SUPP_RATES; + *pos++ = sband->n_bitrates - 8; + for (i = 8; 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); + } + } + + 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 && + sband->ht_cap.ht_supported) { + 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++ = 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)) + return; + + rcu_assign_pointer(ifibss->presp, presp); + + 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; + + 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, 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, 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; + const struct cfg80211_bss_ies *ies; + u64 tsf; + + 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; + } + } + } + + rcu_read_lock(); + ies = rcu_dereference(cbss->ies); + tsf = ies->tsf; + rcu_read_unlock(); + + __ieee80211_sta_join_ibss(sdata, cbss->bssid, + beacon_int, + cbss->channel, + basic_rates, + cbss->capability, + 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, 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, 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) + 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_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 (cfg80211_get_chandef_type(&chandef) != + sdata->u.ibss.channel_type) + 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 */ + + /* 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 beacon_data *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 = 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; + 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; + + 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; + + 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); + mutex_init(&ifibss->mtx); + INIT_LIST_HEAD(&ifibss->incomplete_stations); + spin_lock_init(&ifibss->incomplete_lock); +} + +/* 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; + + mutex_lock(&sdata->u.ibss.mtx); + + 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.basic_rates = params->basic_rates; + 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.channel = params->chandef.chan; + sdata->u.ibss.channel_type = + cfg80211_get_chandef_type(¶ms->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; + + mutex_unlock(&sdata->u.ibss.mtx); + + /* + * 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; + struct ieee80211_local *local = sdata->local; + struct cfg80211_bss *cbss; + u16 capability; + int active_ibss; + struct sta_info *sta; + struct beacon_data *presp; + + mutex_lock(&sdata->u.ibss.mtx); + + active_ibss = ieee80211_sta_active_ibss(sdata); + + if (!active_ibss && !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->channel, + 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(local->hw.wiphy, cbss); + } + } + + ifibss->state = IEEE80211_IBSS_MLME_SEARCH; + memset(ifibss->bssid, 0, ETH_ALEN); + ifibss->ssid_len = 0; + + 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); + + /* remove beacon */ + kfree(sdata->u.ibss.ie); + presp = rcu_dereference_protected(ifibss->presp, + lockdep_is_held(&sdata->u.ibss.mtx)); + RCU_INIT_POINTER(sdata->u.ibss.presp, NULL); + 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; + clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state); + ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED | + BSS_CHANGED_IBSS); + ieee80211_vif_release_channel(sdata); + synchronize_rcu(); + kfree(presp); + + skb_queue_purge(&sdata->skb_queue); + + del_timer_sync(&sdata->u.ibss.timer); + + mutex_unlock(&sdata->u.ibss.mtx); + + return 0; +} |