text: // SPDX-License-Identifier: GPL-2.0
  /*
   * Some IBSS support code for cfg80211.
   *
   * Copyright 2009	Johannes Berg <johannes@sipsolutions.net>
   */
  
  #include <linux/etherdevice.h>
  #include <linux/if_arp.h>
  #include <linux/slab.h>
  #include <linux/export.h>
  #include <net/cfg80211.h>
  #include "wext-compat.h"
  #include "nl80211.h"
  #include "rdev-ops.h"
  
  
  void __cfg80211_ibss_joined(struct net_device *dev, const u8 *bssid,
  			    struct ieee80211_channel *channel)
  {
  	struct wireless_dev *wdev = dev->ieee80211_ptr;
  	struct cfg80211_bss *bss;
  #ifdef CONFIG_CFG80211_WEXT
  	union iwreq_data wrqu;
  #endif
  
  	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
  		return;
  
  	if (!wdev->ssid_len)
  		return;
  
  	bss = cfg80211_get_bss(wdev->wiphy, channel, bssid, NULL, 0,
  			       IEEE80211_BSS_TYPE_IBSS, IEEE80211_PRIVACY_ANY);
  
  	if (WARN_ON(!bss))
  		return;
  
  	if (wdev->current_bss) {
  		cfg80211_unhold_bss(wdev->current_bss);
  		cfg80211_put_bss(wdev->wiphy, &wdev->current_bss->pub);
  	}
  
  	cfg80211_hold_bss(bss_from_pub(bss));
  	wdev->current_bss = bss_from_pub(bss);
  
  	if (!(wdev->wiphy->flags & WIPHY_FLAG_HAS_STATIC_WEP))
  		cfg80211_upload_connect_keys(wdev);
  
  	nl80211_send_ibss_bssid(wiphy_to_rdev(wdev->wiphy), dev, bssid,
  				GFP_KERNEL);
  #ifdef CONFIG_CFG80211_WEXT
  	memset(&wrqu, 0, sizeof(wrqu));
  	memcpy(wrqu.ap_addr.sa_data, bssid, ETH_ALEN);
  	wireless_send_event(dev, SIOCGIWAP, &wrqu, NULL);
  #endif
  }
  
  void cfg80211_ibss_joined(struct net_device *dev, const u8 *bssid,
  			  struct ieee80211_channel *channel, gfp_t gfp)
  {
  	struct wireless_dev *wdev = dev->ieee80211_ptr;
  	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
  	struct cfg80211_event *ev;
  	unsigned long flags;
  
  	trace_cfg80211_ibss_joined(dev, bssid, channel);
  
  	if (WARN_ON(!channel))
  		return;
  
  	ev = kzalloc(sizeof(*ev), gfp);
  	if (!ev)
  		return;
  
  	ev->type = EVENT_IBSS_JOINED;
  	memcpy(ev->ij.bssid, bssid, ETH_ALEN);
  	ev->ij.channel = channel;
  
  	spin_lock_irqsave(&wdev->event_lock, flags);
  	list_add_tail(&ev->list, &wdev->event_list);
  	spin_unlock_irqrestore(&wdev->event_lock, flags);
  	queue_work(cfg80211_wq, &rdev->event_work);
  }
  EXPORT_SYMBOL(cfg80211_ibss_joined);
  
  int __cfg80211_join_ibss(struct cfg80211_registered_device *rdev,
  			 struct net_device *dev,
  			 struct cfg80211_ibss_params *params,
  			 struct cfg80211_cached_keys *connkeys)
  {
  	struct wireless_dev *wdev = dev->ieee80211_ptr;
  	int err;
  
  	ASSERT_RTNL();
  	ASSERT_WDEV_LOCK(wdev);
  
  	if (wdev->ssid_len)
  		return -EALREADY;
  
  	if (!params->basic_rates) {
  		/*
  		* If no rates were explicitly configured,
  		* use the mandatory rate set for 11b or
  		* 11a for maximum compatibility.
  		*/
  		struct ieee80211_supported_band *sband =
  			rdev->wiphy.bands[params->chandef.chan->band];
  		int j;
  		u32 flag = params->chandef.chan->band == NL80211_BAND_5GHZ ?
  			IEEE80211_RATE_MANDATORY_A :
  			IEEE80211_RATE_MANDATORY_B;
  
  		for (j = 0; j < sband->n_bitrates; j++) {
  			if (sband->bitrates[j].flags & flag)
  				params->basic_rates |= BIT(j);
  		}
  	}
  
  	if (WARN_ON(connkeys && connkeys->def < 0))
  		return -EINVAL;
  
  	if (WARN_ON(wdev->connect_keys))
  		kzfree(wdev->connect_keys);
  	wdev->connect_keys = connkeys;
  
  	wdev->ibss_fixed = params->channel_fixed;
  	wdev->ibss_dfs_possible = params->userspace_handles_dfs;
  	wdev->chandef = params->chandef;
  	if (connkeys) {
  		params->wep_keys = connkeys->params;
  		params->wep_tx_key = connkeys->def;
  	}
  
  #ifdef CONFIG_CFG80211_WEXT
  	wdev->wext.ibss.chandef = params->chandef;
  #endif
  	err = rdev_join_ibss(rdev, dev, params);
  	if (err) {
  		wdev->connect_keys = NULL;
  		return err;
  	}
  
  	memcpy(wdev->ssid, params->ssid, params->ssid_len);
  	wdev->ssid_len = params->ssid_len;
  
  	return 0;
  }
  
  static void __cfg80211_clear_ibss(struct net_device *dev, bool nowext)
  {
  	struct wireless_dev *wdev = dev->ieee80211_ptr;
  	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
  	int i;
  
  	ASSERT_WDEV_LOCK(wdev);
  
  	kzfree(wdev->connect_keys);
  	wdev->connect_keys = NULL;
  
  	rdev_set_qos_map(rdev, dev, NULL);
  
  	/*
  	 * Delete all the keys ... pairwise keys can't really
  	 * exist any more anyway, but default keys might.
  	 */
  	if (rdev->ops->del_key)
  		for (i = 0; i < 6; i++)
  			rdev_del_key(rdev, dev, i, false, NULL);
  
  	if (wdev->current_bss) {
  		cfg80211_unhold_bss(wdev->current_bss);
  		cfg80211_put_bss(wdev->wiphy, &wdev->current_bss->pub);
  	}
  
  	wdev->current_bss = NULL;
  	wdev->ssid_len = 0;
  	memset(&wdev->chandef, 0, sizeof(wdev->chandef));
  #ifdef CONFIG_CFG80211_WEXT
  	if (!nowext)
  		wdev->wext.ibss.ssid_len = 0;
  #endif
  	cfg80211_sched_dfs_chan_update(rdev);
  }
  
  void cfg80211_clear_ibss(struct net_device *dev, bool nowext)
  {
  	struct wireless_dev *wdev = dev->ieee80211_ptr;
  
  	wdev_lock(wdev);
  	__cfg80211_clear_ibss(dev, nowext);
  	wdev_unlock(wdev);
  }
  
  int __cfg80211_leave_ibss(struct cfg80211_registered_device *rdev,
  			  struct net_device *dev, bool nowext)
  {
  	struct wireless_dev *wdev = dev->ieee80211_ptr;
  	int err;
  
  	ASSERT_WDEV_LOCK(wdev);
  
  	if (!wdev->ssid_len)
  		return -ENOLINK;
  
  	err = rdev_leave_ibss(rdev, dev);
  
  	if (err)
  		return err;
  
  	wdev->conn_owner_nlportid = 0;
  	__cfg80211_clear_ibss(dev, nowext);
  
  	return 0;
  }
  
  int cfg80211_leave_ibss(struct cfg80211_registered_device *rdev,
  			struct net_device *dev, bool nowext)
  {
  	struct wireless_dev *wdev = dev->ieee80211_ptr;
  	int err;
  
  	wdev_lock(wdev);
  	err = __cfg80211_leave_ibss(rdev, dev, nowext);
  	wdev_unlock(wdev);
  
  	return err;
  }
  
  #ifdef CONFIG_CFG80211_WEXT
  int cfg80211_ibss_wext_join(struct cfg80211_registered_device *rdev,
  			    struct wireless_dev *wdev)
  {
  	struct cfg80211_cached_keys *ck = NULL;
  	enum nl80211_band band;
  	int i, err;
  
  	ASSERT_WDEV_LOCK(wdev);
  
  	if (!wdev->wext.ibss.beacon_interval)
  		wdev->wext.ibss.beacon_interval = 100;
  
  	/* try to find an IBSS channel if none requested ... */
  	if (!wdev->wext.ibss.chandef.chan) {
  		struct ieee80211_channel *new_chan = NULL;
  
  		for (band = 0; band < NUM_NL80211_BANDS; band++) {
  			struct ieee80211_supported_band *sband;
  			struct ieee80211_channel *chan;
  
  			sband = rdev->wiphy.bands[band];
  			if (!sband)
  				continue;
  
  			for (i = 0; i < sband->n_channels; i++) {
  				chan = &sband->channels[i];
  				if (chan->flags & IEEE80211_CHAN_NO_IR)
  					continue;
  				if (chan->flags & IEEE80211_CHAN_DISABLED)
  					continue;
  				new_chan = chan;
  				break;
  			}
  
  			if (new_chan)
  				break;
  		}
  
  		if (!new_chan)
  			return -EINVAL;
  
  		cfg80211_chandef_create(&wdev->wext.ibss.chandef, new_chan,
  					NL80211_CHAN_NO_HT);
  	}
  
  	/* don't join -- SSID is not there */
  	if (!wdev->wext.ibss.ssid_len)
  		return 0;
  
  	if (!netif_running(wdev->netdev))
  		return 0;
  
  	if (wdev->wext.keys)
  		wdev->wext.keys->def = wdev->wext.default_key;
  
  	wdev->wext.ibss.privacy = wdev->wext.default_key != -1;
  
  	if (wdev->wext.keys && wdev->wext.keys->def != -1) {
  		ck = kmemdup(wdev->wext.keys, sizeof(*ck), GFP_KERNEL);
  		if (!ck)
  			return -ENOMEM;
  		for (i = 0; i < CFG80211_MAX_WEP_KEYS; i++)
  			ck->params[i].key = ck->data[i];
  	}
  	err = __cfg80211_join_ibss(rdev, wdev->netdev,
  				   &wdev->wext.ibss, ck);
  	if (err)
  		kfree(ck);
  
  	return err;
  }
  
  int cfg80211_ibss_wext_siwfreq(struct net_device *dev,
  			       struct iw_request_info *info,
  			       struct iw_freq *wextfreq, char *extra)
  {
  	struct wireless_dev *wdev = dev->ieee80211_ptr;
  	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
  	struct ieee80211_channel *chan = NULL;
  	int err, freq;
  
  	/* call only for ibss! */
  	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
  		return -EINVAL;
  
  	if (!rdev->ops->join_ibss)
  		return -EOPNOTSUPP;
  
  	freq = cfg80211_wext_freq(wextfreq);
  	if (freq < 0)
  		return freq;
  
  	if (freq) {
  		chan = ieee80211_get_channel(wdev->wiphy, freq);
  		if (!chan)
  			return -EINVAL;
  		if (chan->flags & IEEE80211_CHAN_NO_IR ||
  		    chan->flags & IEEE80211_CHAN_DISABLED)
  			return -EINVAL;
  	}
  
  	if (wdev->wext.ibss.chandef.chan == chan)
  		return 0;
  
  	wdev_lock(wdev);
  	err = 0;
  	if (wdev->ssid_len)
  		err = __cfg80211_leave_ibss(rdev, dev, true);
  	wdev_unlock(wdev);
  
  	if (err)
  		return err;
  
  	if (chan) {
  		cfg80211_chandef_create(&wdev->wext.ibss.chandef, chan,
  					NL80211_CHAN_NO_HT);
  		wdev->wext.ibss.channel_fixed = true;
  	} else {
  		/* cfg80211_ibss_wext_join will pick one if needed */
  		wdev->wext.ibss.channel_fixed = false;
  	}
  
  	wdev_lock(wdev);
  	err = cfg80211_ibss_wext_join(rdev, wdev);
  	wdev_unlock(wdev);
  
  	return err;
  }
  
  int cfg80211_ibss_wext_giwfreq(struct net_device *dev,
  			       struct iw_request_info *info,
  			       struct iw_freq *freq, char *extra)
  {
  	struct wireless_dev *wdev = dev->ieee80211_ptr;
  	struct ieee80211_channel *chan = NULL;
  
  	/* call only for ibss! */
  	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
  		return -EINVAL;
  
  	wdev_lock(wdev);
  	if (wdev->current_bss)
  		chan = wdev->current_bss->pub.channel;
  	else if (wdev->wext.ibss.chandef.chan)
  		chan = wdev->wext.ibss.chandef.chan;
  	wdev_unlock(wdev);
  
  	if (chan) {
  		freq->m = chan->center_freq;
  		freq->e = 6;
  		return 0;
  	}
  
  	/* no channel if not joining */
  	return -EINVAL;
  }
  
  int cfg80211_ibss_wext_siwessid(struct net_device *dev,
  				struct iw_request_info *info,
  				struct iw_point *data, char *ssid)
  {
  	struct wireless_dev *wdev = dev->ieee80211_ptr;
  	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
  	size_t len = data->length;
  	int err;
  
  	/* call only for ibss! */
  	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
  		return -EINVAL;
  
  	if (!rdev->ops->join_ibss)
  		return -EOPNOTSUPP;
  
  	wdev_lock(wdev);
  	err = 0;
  	if (wdev->ssid_len)
  		err = __cfg80211_leave_ibss(rdev, dev, true);
  	wdev_unlock(wdev);
  
  	if (err)
  		return err;
  
  	/* iwconfig uses nul termination in SSID.. */
  	if (len > 0 && ssid[len - 1] == '\0')
  		len--;
  
  	memcpy(wdev->ssid, ssid, len);
  	wdev->wext.ibss.ssid = wdev->ssid;
  	wdev->wext.ibss.ssid_len = len;
  
  	wdev_lock(wdev);
  	err = cfg80211_ibss_wext_join(rdev, wdev);
  	wdev_unlock(wdev);
  
  	return err;
  }
  
  int cfg80211_ibss_wext_giwessid(struct net_device *dev,
  				struct iw_request_info *info,
  				struct iw_point *data, char *ssid)
  {
  	struct wireless_dev *wdev = dev->ieee80211_ptr;
  
  	/* call only for ibss! */
  	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
  		return -EINVAL;
  
  	data->flags = 0;
  
  	wdev_lock(wdev);
  	if (wdev->ssid_len) {
  		data->flags = 1;
  		data->length = wdev->ssid_len;
  		memcpy(ssid, wdev->ssid, data->length);
  	} else if (wdev->wext.ibss.ssid && wdev->wext.ibss.ssid_len) {
  		data->flags = 1;
  		data->length = wdev->wext.ibss.ssid_len;
  		memcpy(ssid, wdev->wext.ibss.ssid, data->length);
  	}
  	wdev_unlock(wdev);
  
  	return 0;
  }
  
  int cfg80211_ibss_wext_siwap(struct net_device *dev,
  			     struct iw_request_info *info,
  			     struct sockaddr *ap_addr, char *extra)
  {
  	struct wireless_dev *wdev = dev->ieee80211_ptr;
  	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
  	u8 *bssid = ap_addr->sa_data;
  	int err;
  
  	/* call only for ibss! */
  	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
  		return -EINVAL;
  
  	if (!rdev->ops->join_ibss)
  		return -EOPNOTSUPP;
  
  	if (ap_addr->sa_family != ARPHRD_ETHER)
  		return -EINVAL;
  
  	/* automatic mode */
  	if (is_zero_ether_addr(bssid) || is_broadcast_ether_addr(bssid))
  		bssid = NULL;
  
  	if (bssid && !is_valid_ether_addr(bssid))
  		return -EINVAL;
  
  	/* both automatic */
  	if (!bssid && !wdev->wext.ibss.bssid)
  		return 0;
  
  	/* fixed already - and no change */
  	if (wdev->wext.ibss.bssid && bssid &&
  	    ether_addr_equal(bssid, wdev->wext.ibss.bssid))
  		return 0;
  
  	wdev_lock(wdev);
  	err = 0;
  	if (wdev->ssid_len)
  		err = __cfg80211_leave_ibss(rdev, dev, true);
  	wdev_unlock(wdev);
  
  	if (err)
  		return err;
  
  	if (bssid) {
  		memcpy(wdev->wext.bssid, bssid, ETH_ALEN);
  		wdev->wext.ibss.bssid = wdev->wext.bssid;
  	} else
  		wdev->wext.ibss.bssid = NULL;
  
  	wdev_lock(wdev);
  	err = cfg80211_ibss_wext_join(rdev, wdev);
  	wdev_unlock(wdev);
  
  	return err;
  }
  
  int cfg80211_ibss_wext_giwap(struct net_device *dev,
  			     struct iw_request_info *info,
  			     struct sockaddr *ap_addr, char *extra)
  {
  	struct wireless_dev *wdev = dev->ieee80211_ptr;
  
  	/* call only for ibss! */
  	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
  		return -EINVAL;
  
  	ap_addr->sa_family = ARPHRD_ETHER;
  
  	wdev_lock(wdev);
  	if (wdev->current_bss)
  		memcpy(ap_addr->sa_data, wdev->current_bss->pub.bssid, ETH_ALEN);
  	else if (wdev->wext.ibss.bssid)
  		memcpy(ap_addr->sa_data, wdev->wext.ibss.bssid, ETH_ALEN);
  	else
  		eth_zero_addr(ap_addr->sa_data);
  
  	wdev_unlock(wdev);
  
  	return 0;
  }
  #endif
  