]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blobdiff - net/mac80211/ibss.c
mac80211: fix scan races and rework scanning
[mirror_ubuntu-bionic-kernel.git] / net / mac80211 / ibss.c
index 3201e1f96365649a5c1ad56f898afa20af9ddf0a..25ff583612ef5d34a2b6e6c5c12ae3841b61f530 100644 (file)
@@ -59,74 +59,59 @@ static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
                                    sdata->u.ibss.bssid, 0);
 }
 
-static int __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
-                                    const u8 *bssid, const int beacon_int,
-                                    const int freq,
-                                    const size_t supp_rates_len,
-                                    const u8 *supp_rates,
-                                    const u16 capability, u64 tsf)
+static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
+                                     const u8 *bssid, const int beacon_int,
+                                     struct ieee80211_channel *chan,
+                                     const size_t supp_rates_len,
+                                     const u8 *supp_rates,
+                                     const u16 capability, u64 tsf)
 {
        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
        struct ieee80211_local *local = sdata->local;
-       int res = 0, rates, i, j;
+       int rates, i, j;
        struct sk_buff *skb;
        struct ieee80211_mgmt *mgmt;
        u8 *pos;
        struct ieee80211_supported_band *sband;
-       union iwreq_data wrqu;
 
        if (local->ops->reset_tsf) {
                /* Reset own TSF to allow time synchronization work. */
                local->ops->reset_tsf(local_to_hw(local));
        }
 
-       if ((ifibss->flags & IEEE80211_IBSS_PREV_BSSID_SET) &&
-          memcmp(ifibss->bssid, bssid, ETH_ALEN) == 0)
-               return res;
+       skb = ifibss->skb;
+       rcu_assign_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);
 
-       skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
-       if (!skb) {
-               printk(KERN_DEBUG "%s: failed to allocate buffer for probe "
-                      "response\n", sdata->dev->name);
-               return -ENOMEM;
-       }
-
-       if (!(ifibss->flags & IEEE80211_IBSS_PREV_BSSID_SET)) {
-               /* Remove possible STA entries from other IBSS networks. */
-               sta_info_flush_delayed(sdata);
-       }
+       if (memcmp(ifibss->bssid, bssid, ETH_ALEN))
+               sta_info_flush(sdata->local, sdata);
 
        memcpy(ifibss->bssid, bssid, ETH_ALEN);
-       res = ieee80211_if_config(sdata, IEEE80211_IFCC_BSSID);
-       if (res)
-               return res;
 
        local->hw.conf.beacon_int = beacon_int >= 10 ? beacon_int : 10;
 
-       sdata->drop_unencrypted = capability &
-               WLAN_CAPABILITY_PRIVACY ? 1 : 0;
+       sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
 
-       res = ieee80211_set_freq(sdata, freq);
+       ieee80211_if_config(sdata, IEEE80211_IFCC_BSSID);
 
-       if (res)
-               return res;
-
-       sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
+       local->oper_channel = chan;
+       local->oper_channel_type = NL80211_CHAN_NO_HT;
+       ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
+       sband = local->hw.wiphy->bands[chan->band];
 
        /* Build IBSS probe response */
-
-       skb_reserve(skb, local->hw.extra_tx_headroom);
-
-       mgmt = (struct ieee80211_mgmt *)
-               skb_put(skb, 24 + sizeof(mgmt->u.beacon));
+       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);
        memset(mgmt->da, 0xff, ETH_ALEN);
        memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
        memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
-       mgmt->u.beacon.beacon_int =
-               cpu_to_le16(local->hw.conf.beacon_int);
+       mgmt->u.beacon.beacon_int = cpu_to_le16(local->hw.conf.beacon_int);
        mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
        mgmt->u.beacon.capab_info = cpu_to_le16(capability);
 
@@ -147,7 +132,7 @@ static int __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
                pos = skb_put(skb, 2 + 1);
                *pos++ = WLAN_EID_DS_PARAMS;
                *pos++ = 1;
-               *pos++ = ieee80211_frequency_to_channel(freq);
+               *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
        }
 
        pos = skb_put(skb, 2 + 2);
@@ -165,12 +150,15 @@ static int __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
                memcpy(pos, &supp_rates[8], rates);
        }
 
-       ifibss->probe_resp = skb;
+       if (ifibss->ie_len)
+               memcpy(skb_put(skb, ifibss->ie_len),
+                      ifibss->ie, ifibss->ie_len);
+
+       rcu_assign_pointer(ifibss->presp, skb);
 
        ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON |
                                   IEEE80211_IFCC_BEACON_ENABLED);
 
-
        rates = 0;
        for (i = 0; i < supp_rates_len; i++) {
                int bitrate = (supp_rates[i] & 0x7f) * 5;
@@ -181,27 +169,24 @@ static int __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 
        ieee80211_sta_def_wmm_params(sdata, supp_rates_len, supp_rates);
 
-       ifibss->flags |= IEEE80211_IBSS_PREV_BSSID_SET;
        ifibss->state = IEEE80211_IBSS_MLME_JOINED;
-       mod_timer(&ifibss->timer, jiffies + IEEE80211_IBSS_MERGE_INTERVAL);
-
-       memset(&wrqu, 0, sizeof(wrqu));
-       memcpy(wrqu.ap_addr.sa_data, bssid, ETH_ALEN);
-       wireless_send_event(sdata->dev, SIOCGIWAP, &wrqu, NULL);
+       mod_timer(&ifibss->timer,
+                 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 
-       return res;
+       cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
+                                 mgmt, skb->len, 0, GFP_KERNEL);
+       cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 }
 
-static int ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
-                                  struct ieee80211_bss *bss)
+static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
+                                   struct ieee80211_bss *bss)
 {
-       return __ieee80211_sta_join_ibss(sdata,
-                                        bss->cbss.bssid,
-                                        bss->cbss.beacon_interval,
-                                        bss->cbss.channel->center_freq,
-                                        bss->supp_rates_len, bss->supp_rates,
-                                        bss->cbss.capability,
-                                        bss->cbss.tsf);
+       __ieee80211_sta_join_ibss(sdata, bss->cbss.bssid,
+                                 bss->cbss.beacon_interval,
+                                 bss->cbss.channel,
+                                 bss->supp_rates_len, bss->supp_rates,
+                                 bss->cbss.capability,
+                                 bss->cbss.tsf);
 }
 
 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
@@ -277,7 +262,7 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
                goto put_bss;
 
        /* we use a fixed BSSID */
-       if (sdata->u.ibss.flags & IEEE80211_IBSS_BSSID_SET)
+       if (sdata->u.ibss.bssid)
                goto put_bss;
 
        /* not an IBSS */
@@ -369,13 +354,14 @@ struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
        struct sta_info *sta;
        int band = local->hw.conf.channel->band;
 
-       /* TODO: Could consider removing the least recently used entry and
-        * allow new one to be added. */
+       /*
+        * XXX: Consider removing the least recently used entry and
+        *      allow new one to be added.
+        */
        if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
-               if (net_ratelimit()) {
-                       printk(KERN_DEBUG "%s: No room for a new IBSS STA "
-                              "entry %pM\n", sdata->dev->name, addr);
-               }
+               if (net_ratelimit())
+                       printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
+                              sdata->dev->name, addr);
                return NULL;
        }
 
@@ -432,30 +418,24 @@ static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 {
        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 
-       mod_timer(&ifibss->timer, jiffies + IEEE80211_IBSS_MERGE_INTERVAL);
+       mod_timer(&ifibss->timer,
+                 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 
        ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
+
        if (ieee80211_sta_active_ibss(sdata))
                return;
 
-       if ((ifibss->flags & IEEE80211_IBSS_BSSID_SET) &&
-           (!(ifibss->flags & IEEE80211_IBSS_AUTO_CHANNEL_SEL)))
+       if (ifibss->fixed_channel)
                return;
 
        printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
               "IBSS networks with same SSID (merge)\n", sdata->dev->name);
 
-       /* XXX maybe racy? */
-       if (sdata->local->scan_req)
-               return;
-
-       memcpy(sdata->local->int_scan_req.ssids[0].ssid,
-              ifibss->ssid, IEEE80211_MAX_SSID_LEN);
-       sdata->local->int_scan_req.ssids[0].ssid_len = ifibss->ssid_len;
-       ieee80211_request_scan(sdata, &sdata->local->int_scan_req);
+       ieee80211_request_internal_scan(sdata, ifibss->ssid, ifibss->ssid_len);
 }
 
-static int ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
+static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 {
        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
        struct ieee80211_local *local = sdata->local;
@@ -466,7 +446,7 @@ static int ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
        u16 capability;
        int i;
 
-       if (ifibss->flags & IEEE80211_IBSS_BSSID_SET) {
+       if (ifibss->fixed_bssid) {
                memcpy(bssid, ifibss->bssid, ETH_ALEN);
        } else {
                /* Generate random, not broadcast, locally administered BSSID. Mix in
@@ -482,7 +462,7 @@ static int ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
        printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
               sdata->dev->name, bssid);
 
-       sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
+       sband = local->hw.wiphy->bands[ifibss->channel->band];
 
        if (local->hw.conf.beacon_int == 0)
                local->hw.conf.beacon_int = 100;
@@ -500,24 +480,20 @@ static int ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
                *pos++ = (u8) (rate / 5);
        }
 
-       return __ieee80211_sta_join_ibss(sdata,
-                                        bssid, local->hw.conf.beacon_int,
-                                        local->hw.conf.channel->center_freq,
-                                        sband->n_bitrates, supp_rates,
-                                        capability, 0);
+       __ieee80211_sta_join_ibss(sdata, bssid, local->hw.conf.beacon_int,
+                                 ifibss->channel, sband->n_bitrates,
+                                 supp_rates, capability, 0);
 }
 
-static int ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
+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 ieee80211_bss *bss;
+       struct ieee80211_channel *chan = NULL;
        const u8 *bssid = NULL;
        int active_ibss;
 
-       if (ifibss->ssid_len == 0)
-               return -EINVAL;
-
        active_ibss = ieee80211_sta_active_ibss(sdata);
 #ifdef CONFIG_MAC80211_IBSS_DEBUG
        printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
@@ -525,11 +501,15 @@ static int ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 
        if (active_ibss)
-               return 0;
+               return;
 
-       if (ifibss->flags & IEEE80211_IBSS_BSSID_SET)
+       if (ifibss->fixed_bssid)
+               bssid = ifibss->bssid;
+       if (ifibss->fixed_channel)
+               chan = ifibss->channel;
+       if (!is_zero_ether_addr(ifibss->bssid))
                bssid = ifibss->bssid;
-       bss = (void *)cfg80211_get_bss(local->hw.wiphy, NULL, bssid,
+       bss = (void *)cfg80211_get_bss(local->hw.wiphy, chan, bssid,
                                       ifibss->ssid, ifibss->ssid_len,
                                       WLAN_CAPABILITY_IBSS,
                                       WLAN_CAPABILITY_IBSS);
@@ -540,18 +520,14 @@ static int ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
                       "%pM\n", bss->cbss.bssid, ifibss->bssid);
 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 
-       if (bss &&
-           (!(ifibss->flags & IEEE80211_IBSS_PREV_BSSID_SET) ||
-            memcmp(ifibss->bssid, bss->cbss.bssid, ETH_ALEN))) {
-               int ret;
-
+       if (bss && memcmp(ifibss->bssid, bss->cbss.bssid, ETH_ALEN)) {
                printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
                       " based on configured SSID\n",
                       sdata->dev->name, bss->cbss.bssid);
 
-               ret = ieee80211_sta_join_ibss(sdata, bss);
+               ieee80211_sta_join_ibss(sdata, bss);
                ieee80211_rx_bss_put(local, bss);
-               return ret;
+               return;
        } else if (bss)
                ieee80211_rx_bss_put(local, bss);
 
@@ -562,29 +538,24 @@ static int ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
        /* Selected IBSS not found in current scan results - try to scan */
        if (ifibss->state == IEEE80211_IBSS_MLME_JOINED &&
            !ieee80211_sta_active_ibss(sdata)) {
-               mod_timer(&ifibss->timer, jiffies +
-                                         IEEE80211_IBSS_MERGE_INTERVAL);
-       } else if (time_after(jiffies, local->last_scan_completed +
+               mod_timer(&ifibss->timer,
+                         round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
+       } else if (time_after(jiffies, ifibss->last_scan_completed +
                                        IEEE80211_SCAN_INTERVAL)) {
                printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
                       "join\n", sdata->dev->name);
 
-               /* XXX maybe racy? */
-               if (local->scan_req)
-                       return -EBUSY;
-
-               memcpy(local->int_scan_req.ssids[0].ssid,
-                      ifibss->ssid, IEEE80211_MAX_SSID_LEN);
-               local->int_scan_req.ssids[0].ssid_len = ifibss->ssid_len;
-               return ieee80211_request_scan(sdata, &local->int_scan_req);
+               ieee80211_request_internal_scan(sdata, ifibss->ssid,
+                                               ifibss->ssid_len);
        } else if (ifibss->state != IEEE80211_IBSS_MLME_JOINED) {
                int interval = IEEE80211_SCAN_INTERVAL;
 
                if (time_after(jiffies, ifibss->ibss_join_req +
                               IEEE80211_IBSS_JOIN_TIMEOUT)) {
-                       if (!(local->oper_channel->flags &
-                                               IEEE80211_CHAN_NO_IBSS))
-                               return ieee80211_sta_create_ibss(sdata);
+                       if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
+                               ieee80211_sta_create_ibss(sdata);
+                               return;
+                       }
                        printk(KERN_DEBUG "%s: IBSS not allowed on"
                               " %d MHz\n", sdata->dev->name,
                               local->hw.conf.channel->center_freq);
@@ -595,11 +566,9 @@ static int ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
                }
 
                ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
-               mod_timer(&ifibss->timer, jiffies + interval);
-               return 0;
+               mod_timer(&ifibss->timer,
+                         round_jiffies(jiffies + interval));
        }
-
-       return 0;
 }
 
 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
@@ -614,7 +583,7 @@ static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
        u8 *pos, *end;
 
        if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
-           len < 24 + 2 || !ifibss->probe_resp)
+           len < 24 + 2 || !ifibss->presp)
                return;
 
        if (local->ops->tx_last_beacon)
@@ -649,13 +618,13 @@ static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
        }
        if (pos[1] != 0 &&
            (pos[1] != ifibss->ssid_len ||
-            memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len) != 0)) {
+            !memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
                /* Ignore ProbeReq for foreign SSID */
                return;
        }
 
        /* Reply with ProbeResp */
-       skb = skb_copy(ifibss->probe_resp, GFP_KERNEL);
+       skb = skb_copy(ifibss->presp, GFP_KERNEL);
        if (!skb)
                return;
 
@@ -794,89 +763,25 @@ void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
        setup_timer(&ifibss->timer, ieee80211_ibss_timer,
                    (unsigned long) sdata);
        skb_queue_head_init(&ifibss->skb_queue);
-
-       ifibss->flags |= IEEE80211_IBSS_AUTO_BSSID_SEL |
-                       IEEE80211_IBSS_AUTO_CHANNEL_SEL;
-}
-
-int ieee80211_ibss_commit(struct ieee80211_sub_if_data *sdata)
-{
-       struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
-
-       ifibss->flags &= ~IEEE80211_IBSS_PREV_BSSID_SET;
-
-       if (ifibss->ssid_len)
-               ifibss->flags |= IEEE80211_IBSS_SSID_SET;
-       else
-               ifibss->flags &= ~IEEE80211_IBSS_SSID_SET;
-
-       ifibss->ibss_join_req = jiffies;
-       ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
-       set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
-
-       return 0;
-}
-
-int ieee80211_ibss_set_ssid(struct ieee80211_sub_if_data *sdata, char *ssid, size_t len)
-{
-       struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
-
-       if (len > IEEE80211_MAX_SSID_LEN)
-               return -EINVAL;
-
-       if (ifibss->ssid_len != len || memcmp(ifibss->ssid, ssid, len) != 0) {
-               memset(ifibss->ssid, 0, sizeof(ifibss->ssid));
-               memcpy(ifibss->ssid, ssid, len);
-               ifibss->ssid_len = len;
-       }
-
-       return ieee80211_ibss_commit(sdata);
-}
-
-int ieee80211_ibss_get_ssid(struct ieee80211_sub_if_data *sdata, char *ssid, size_t *len)
-{
-       struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
-
-       memcpy(ssid, ifibss->ssid, ifibss->ssid_len);
-       *len = ifibss->ssid_len;
-
-       return 0;
-}
-
-int ieee80211_ibss_set_bssid(struct ieee80211_sub_if_data *sdata, u8 *bssid)
-{
-       struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
-
-       if (is_valid_ether_addr(bssid)) {
-               memcpy(ifibss->bssid, bssid, ETH_ALEN);
-               ifibss->flags |= IEEE80211_IBSS_BSSID_SET;
-       } else {
-               memset(ifibss->bssid, 0, ETH_ALEN);
-               ifibss->flags &= ~IEEE80211_IBSS_BSSID_SET;
-       }
-
-       if (netif_running(sdata->dev)) {
-               if (ieee80211_if_config(sdata, IEEE80211_IFCC_BSSID)) {
-                       printk(KERN_DEBUG "%s: Failed to config new BSSID to "
-                              "the low-level driver\n", sdata->dev->name);
-               }
-       }
-
-       return ieee80211_ibss_commit(sdata);
 }
 
 /* scan finished notification */
 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 {
-       struct ieee80211_sub_if_data *sdata = local->scan_sdata;
-       struct ieee80211_if_ibss *ifibss;
-
-       if (sdata && sdata->vif.type == NL80211_IFTYPE_ADHOC) {
-               ifibss = &sdata->u.ibss;
-               if ((!(ifibss->flags & IEEE80211_IBSS_PREV_BSSID_SET)) ||
-                   !ieee80211_sta_active_ibss(sdata))
-                       ieee80211_sta_find_ibss(sdata);
+       struct ieee80211_sub_if_data *sdata;
+
+       mutex_lock(&local->iflist_mtx);
+       list_for_each_entry(sdata, &local->interfaces, list) {
+               if (!netif_running(sdata->dev))
+                       continue;
+               if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
+                       continue;
+               if (!sdata->u.ibss.ssid_len)
+                       continue;
+               sdata->u.ibss.last_scan_completed = jiffies;
+               ieee80211_sta_find_ibss(sdata);
        }
+       mutex_unlock(&local->iflist_mtx);
 }
 
 ieee80211_rx_result
@@ -906,3 +811,79 @@ ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
 
        return RX_DROP_MONITOR;
 }
+
+int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
+                       struct cfg80211_ibss_params *params)
+{
+       struct sk_buff *skb;
+
+       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.channel = params->channel;
+       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;
+       }
+
+       skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
+                           36 /* bitrates */ +
+                           34 /* SSID */ +
+                           3  /* DS params */ +
+                           4  /* IBSS params */ +
+                           params->ie_len);
+       if (!skb)
+               return -ENOMEM;
+
+       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, IEEE80211_MAX_SSID_LEN);
+
+       /*
+        * The ssid_len setting below is used to see whether
+        * we are active, and we need all other settings
+        * before that may get visible.
+        */
+       mb();
+
+       sdata->u.ibss.ssid_len = params->ssid_len;
+
+       set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
+       queue_work(sdata->local->hw.workqueue, &sdata->u.ibss.work);
+
+       return 0;
+}
+
+int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
+{
+       struct sk_buff *skb;
+
+       del_timer_sync(&sdata->u.ibss.timer);
+       clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
+       cancel_work_sync(&sdata->u.ibss.work);
+       clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
+
+       sta_info_flush(sdata->local, sdata);
+
+       /* remove beacon */
+       kfree(sdata->u.ibss.ie);
+       skb = sdata->u.ibss.presp;
+       rcu_assign_pointer(sdata->u.ibss.presp, NULL);
+       ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON_ENABLED);
+       synchronize_rcu();
+       kfree_skb(skb);
+
+       skb_queue_purge(&sdata->u.ibss.skb_queue);
+       memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
+
+       return 0;
+}