/* * IBSS mode implementation * Copyright 2003-2008, Jouni Malinen * Copyright 2004, Instant802 Networks, Inc. * Copyright 2005, Devicescape Software, Inc. * Copyright 2006-2007 Jiri Benc * Copyright 2007, Michael Wu * Copyright 2009, Johannes Berg * * 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 #include #include #include #include #include #include #include #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.enable_beacon = true; 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(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 && 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_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 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; 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) { struct sk_buff *skb; u32 changed = 0; skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom + 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) + params->ie_len); if (!skb) return -ENOMEM; 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.skb = skb; 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 sk_buff *skb; 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; 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); skb = rcu_dereference_protected(sdata->u.ibss.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; clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state); ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED | BSS_CHANGED_IBSS); synchronize_rcu(); kfree_skb(skb); skb_queue_purge(&sdata->skb_queue); del_timer_sync(&sdata->u.ibss.timer); mutex_unlock(&sdata->u.ibss.mtx); return 0; }