net/mac80211/util.c - LeafOS-Devices/android_kernel_realme_mt6785 - Gitiles

 /*
  * Copyright 2002-2005, Instant802 Networks, Inc.
  * Copyright 2005-2006, Devicescape Software, Inc.
  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
  * Copyright 2007	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.
  *
  * utilities for mac80211
  */

 #include <net/mac80211.h>
 #include <linux/netdevice.h>
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/skbuff.h>
 #include <linux/etherdevice.h>
 #include <linux/if_arp.h>
 #include <linux/wireless.h>
 #include <linux/bitmap.h>
 #include <net/net_namespace.h>
 #include <net/cfg80211.h>
 #include <net/rtnetlink.h>

 #include "ieee80211_i.h"
 #include "rate.h"
 #include "mesh.h"
 #include "wme.h"

 /* privid for wiphys to determine whether they belong to us or not */
 void *mac80211_wiphy_privid = &mac80211_wiphy_privid;

 /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
 /* Ethernet-II snap header (RFC1042 for most EtherTypes) */
 const unsigned char rfc1042_header[] __aligned(2) =
 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };

 /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
 const unsigned char bridge_tunnel_header[] __aligned(2) =
 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };


 u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len,
 			enum nl80211_iftype type)
 {
 	__le16 fc = hdr->frame_control;

 	 /* drop ACK/CTS frames and incorrect hdr len (ctrl) */
 	if (len < 16)
 		return NULL;

 	if (ieee80211_is_data(fc)) {
 		if (len < 24) /* drop incorrect hdr len (data) */
 			return NULL;

 		if (ieee80211_has_a4(fc))
 			return NULL;
 		if (ieee80211_has_tods(fc))
 			return hdr->addr1;
 		if (ieee80211_has_fromds(fc))
 			return hdr->addr2;

 		return hdr->addr3;
 	}

 	if (ieee80211_is_mgmt(fc)) {
 		if (len < 24) /* drop incorrect hdr len (mgmt) */
 			return NULL;
 		return hdr->addr3;
 	}

 	if (ieee80211_is_ctl(fc)) {
 		if(ieee80211_is_pspoll(fc))
 			return hdr->addr1;

 		if (ieee80211_is_back_req(fc)) {
 			switch (type) {
 			case NL80211_IFTYPE_STATION:
 				return hdr->addr2;
 			case NL80211_IFTYPE_AP:
 			case NL80211_IFTYPE_AP_VLAN:
 				return hdr->addr1;
 			default:
 				break; /* fall through to the return */
 			}
 		}
 	}

 	return NULL;
 }

 unsigned int ieee80211_hdrlen(__le16 fc)
 {
 	unsigned int hdrlen = 24;

 	if (ieee80211_is_data(fc)) {
 		if (ieee80211_has_a4(fc))
 			hdrlen = 30;
 		if (ieee80211_is_data_qos(fc))
 			hdrlen += IEEE80211_QOS_CTL_LEN;
 		goto out;
 	}

 	if (ieee80211_is_ctl(fc)) {
 		/*
 		 * ACK and CTS are 10 bytes, all others 16. To see how
 		 * to get this condition consider
 		 *   subtype mask:   0b0000000011110000 (0x00F0)
 		 *   ACK subtype:    0b0000000011010000 (0x00D0)
 		 *   CTS subtype:    0b0000000011000000 (0x00C0)
 		 *   bits that matter:         ^^^      (0x00E0)
 		 *   value of those: 0b0000000011000000 (0x00C0)
 		 */
 		if ((fc & cpu_to_le16(0x00E0)) == cpu_to_le16(0x00C0))
 			hdrlen = 10;
 		else
 			hdrlen = 16;
 	}
 out:
 	return hdrlen;
 }
 EXPORT_SYMBOL(ieee80211_hdrlen);

 unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
 {
 	const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *)skb->data;
 	unsigned int hdrlen;

 	if (unlikely(skb->len < 10))
 		return 0;
 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
 	if (unlikely(hdrlen > skb->len))
 		return 0;
 	return hdrlen;
 }
 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);

 int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
 {
 	int ae = meshhdr->flags & IEEE80211S_FLAGS_AE;
 	/* 7.1.3.5a.2 */
 	switch (ae) {
 	case 0:
 		return 6;
 	case 1:
 		return 12;
 	case 2:
 		return 18;
 	case 3:
 		return 24;
 	default:
 		return 6;
 	}
 }

 void ieee80211_tx_set_protected(struct ieee80211_tx_data *tx)
 {
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;

 	hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
 	if (tx->extra_frag) {
 		struct ieee80211_hdr *fhdr;
 		int i;
 		for (i = 0; i < tx->num_extra_frag; i++) {
 			fhdr = (struct ieee80211_hdr *)
 				tx->extra_frag[i]->data;
 			fhdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
 		}
 	}
 }

 int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
 			     int rate, int erp, int short_preamble)
 {
 	int dur;

 	/* calculate duration (in microseconds, rounded up to next higher
 	 * integer if it includes a fractional microsecond) to send frame of
 	 * len bytes (does not include FCS) at the given rate. Duration will
 	 * also include SIFS.
 	 *
 	 * rate is in 100 kbps, so divident is multiplied by 10 in the
 	 * DIV_ROUND_UP() operations.
 	 */

 	if (local->hw.conf.channel->band == IEEE80211_BAND_5GHZ || erp) {
 		/*
 		 * OFDM:
 		 *
 		 * N_DBPS = DATARATE x 4
 		 * N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS)
 		 *	(16 = SIGNAL time, 6 = tail bits)
 		 * TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext
 		 *
 		 * T_SYM = 4 usec
 		 * 802.11a - 17.5.2: aSIFSTime = 16 usec
 		 * 802.11g - 19.8.4: aSIFSTime = 10 usec +
 		 *	signal ext = 6 usec
 		 */
 		dur = 16; /* SIFS + signal ext */
 		dur += 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */
 		dur += 4; /* 17.3.2.3: T_SIGNAL = 4 usec */
 		dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10,
 					4 * rate); /* T_SYM x N_SYM */
 	} else {
 		/*
 		 * 802.11b or 802.11g with 802.11b compatibility:
 		 * 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime +
 		 * Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0.
 		 *
 		 * 802.11 (DS): 15.3.3, 802.11b: 18.3.4
 		 * aSIFSTime = 10 usec
 		 * aPreambleLength = 144 usec or 72 usec with short preamble
 		 * aPLCPHeaderLength = 48 usec or 24 usec with short preamble
 		 */
 		dur = 10; /* aSIFSTime = 10 usec */
 		dur += short_preamble ? (72 + 24) : (144 + 48);

 		dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate);
 	}

 	return dur;
 }

 /* Exported duration function for driver use */
 __le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw,
 					struct ieee80211_vif *vif,
 					size_t frame_len,
 					struct ieee80211_rate *rate)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
 	struct ieee80211_sub_if_data *sdata;
 	u16 dur;
 	int erp;
 	bool short_preamble = false;

 	erp = 0;
 	if (vif) {
 		sdata = vif_to_sdata(vif);
 		short_preamble = sdata->bss_conf.use_short_preamble;
 		if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
 			erp = rate->flags & IEEE80211_RATE_ERP_G;
 	}

 	dur = ieee80211_frame_duration(local, frame_len, rate->bitrate, erp,
 				       short_preamble);

 	return cpu_to_le16(dur);
 }
 EXPORT_SYMBOL(ieee80211_generic_frame_duration);

 __le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
 			      struct ieee80211_vif *vif, size_t frame_len,
 			      const struct ieee80211_tx_info *frame_txctl)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
 	struct ieee80211_rate *rate;
 	struct ieee80211_sub_if_data *sdata;
 	bool short_preamble;
 	int erp;
 	u16 dur;
 	struct ieee80211_supported_band *sband;

 	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];

 	short_preamble = false;

 	rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];

 	erp = 0;
 	if (vif) {
 		sdata = vif_to_sdata(vif);
 		short_preamble = sdata->bss_conf.use_short_preamble;
 		if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
 			erp = rate->flags & IEEE80211_RATE_ERP_G;
 	}

 	/* CTS duration */
 	dur = ieee80211_frame_duration(local, 10, rate->bitrate,
 				       erp, short_preamble);
 	/* Data frame duration */
 	dur += ieee80211_frame_duration(local, frame_len, rate->bitrate,
 					erp, short_preamble);
 	/* ACK duration */
 	dur += ieee80211_frame_duration(local, 10, rate->bitrate,
 					erp, short_preamble);

 	return cpu_to_le16(dur);
 }
 EXPORT_SYMBOL(ieee80211_rts_duration);

 __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
 				    struct ieee80211_vif *vif,
 				    size_t frame_len,
 				    const struct ieee80211_tx_info *frame_txctl)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
 	struct ieee80211_rate *rate;
 	struct ieee80211_sub_if_data *sdata;
 	bool short_preamble;
 	int erp;
 	u16 dur;
 	struct ieee80211_supported_band *sband;

 	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];

 	short_preamble = false;

 	rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];
 	erp = 0;
 	if (vif) {
 		sdata = vif_to_sdata(vif);
 		short_preamble = sdata->bss_conf.use_short_preamble;
 		if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
 			erp = rate->flags & IEEE80211_RATE_ERP_G;
 	}

 	/* Data frame duration */
 	dur = ieee80211_frame_duration(local, frame_len, rate->bitrate,
 				       erp, short_preamble);
 	if (!(frame_txctl->flags & IEEE80211_TX_CTL_NO_ACK)) {
 		/* ACK duration */
 		dur += ieee80211_frame_duration(local, 10, rate->bitrate,
 						erp, short_preamble);
 	}

 	return cpu_to_le16(dur);
 }
 EXPORT_SYMBOL(ieee80211_ctstoself_duration);

 void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue)
 {
 	struct ieee80211_local *local = hw_to_local(hw);

 	if (test_bit(queue, local->queues_pending)) {
 		set_bit(queue, local->queues_pending_run);
 		tasklet_schedule(&local->tx_pending_tasklet);
 	} else {
 		netif_wake_subqueue(local->mdev, queue);
 	}
 }
 EXPORT_SYMBOL(ieee80211_wake_queue);

 void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue)
 {
 	struct ieee80211_local *local = hw_to_local(hw);

 	netif_stop_subqueue(local->mdev, queue);
 }
 EXPORT_SYMBOL(ieee80211_stop_queue);

 void ieee80211_stop_queues(struct ieee80211_hw *hw)
 {
 	int i;

 	for (i = 0; i < ieee80211_num_queues(hw); i++)
 		ieee80211_stop_queue(hw, i);
 }
 EXPORT_SYMBOL(ieee80211_stop_queues);

 int ieee80211_queue_stopped(struct ieee80211_hw *hw, int queue)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
 	return __netif_subqueue_stopped(local->mdev, queue);
 }
 EXPORT_SYMBOL(ieee80211_queue_stopped);

 void ieee80211_wake_queues(struct ieee80211_hw *hw)
 {
 	int i;

 	for (i = 0; i < hw->queues + hw->ampdu_queues; i++)
 		ieee80211_wake_queue(hw, i);
 }
 EXPORT_SYMBOL(ieee80211_wake_queues);

 void ieee80211_iterate_active_interfaces(
 	struct ieee80211_hw *hw,
 	void (*iterator)(void *data, u8 *mac,
 			 struct ieee80211_vif *vif),
 	void *data)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
 	struct ieee80211_sub_if_data *sdata;

 	rtnl_lock();

 	list_for_each_entry(sdata, &local->interfaces, list) {
 		switch (sdata->vif.type) {
 		case __NL80211_IFTYPE_AFTER_LAST:
 		case NL80211_IFTYPE_UNSPECIFIED:
 		case NL80211_IFTYPE_MONITOR:
 		case NL80211_IFTYPE_AP_VLAN:
 			continue;
 		case NL80211_IFTYPE_AP:
 		case NL80211_IFTYPE_STATION:
 		case NL80211_IFTYPE_ADHOC:
 		case NL80211_IFTYPE_WDS:
 		case NL80211_IFTYPE_MESH_POINT:
 			break;
 		}
 		if (netif_running(sdata->dev))
 			iterator(data, sdata->dev->dev_addr,
 				 &sdata->vif);
 	}

 	rtnl_unlock();
 }
 EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);

 void ieee80211_iterate_active_interfaces_atomic(
 	struct ieee80211_hw *hw,
 	void (*iterator)(void *data, u8 *mac,
 			 struct ieee80211_vif *vif),
 	void *data)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
 	struct ieee80211_sub_if_data *sdata;

 	rcu_read_lock();

 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 		switch (sdata->vif.type) {
 		case __NL80211_IFTYPE_AFTER_LAST:
 		case NL80211_IFTYPE_UNSPECIFIED:
 		case NL80211_IFTYPE_MONITOR:
 		case NL80211_IFTYPE_AP_VLAN:
 			continue;
 		case NL80211_IFTYPE_AP:
 		case NL80211_IFTYPE_STATION:
 		case NL80211_IFTYPE_ADHOC:
 		case NL80211_IFTYPE_WDS:
 		case NL80211_IFTYPE_MESH_POINT:
 			break;
 		}
 		if (netif_running(sdata->dev))
 			iterator(data, sdata->dev->dev_addr,
 				 &sdata->vif);
 	}

 	rcu_read_unlock();
 }
 EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces_atomic);

 void ieee802_11_parse_elems(u8 *start, size_t len,
 			    struct ieee802_11_elems *elems)
 {
 	size_t left = len;
 	u8 *pos = start;

 	memset(elems, 0, sizeof(*elems));
 	elems->ie_start = start;
 	elems->total_len = len;

 	while (left >= 2) {
 		u8 id, elen;

 		id = *pos++;
 		elen = *pos++;
 		left -= 2;

 		if (elen > left)
 			return;

 		switch (id) {
 		case WLAN_EID_SSID:
 			elems->ssid = pos;
 			elems->ssid_len = elen;
 			break;
 		case WLAN_EID_SUPP_RATES:
 			elems->supp_rates = pos;
 			elems->supp_rates_len = elen;
 			break;
 		case WLAN_EID_FH_PARAMS:
 			elems->fh_params = pos;
 			elems->fh_params_len = elen;
 			break;
 		case WLAN_EID_DS_PARAMS:
 			elems->ds_params = pos;
 			elems->ds_params_len = elen;
 			break;
 		case WLAN_EID_CF_PARAMS:
 			elems->cf_params = pos;
 			elems->cf_params_len = elen;
 			break;
 		case WLAN_EID_TIM:
 			elems->tim = pos;
 			elems->tim_len = elen;
 			break;
 		case WLAN_EID_IBSS_PARAMS:
 			elems->ibss_params = pos;
 			elems->ibss_params_len = elen;
 			break;
 		case WLAN_EID_CHALLENGE:
 			elems->challenge = pos;
 			elems->challenge_len = elen;
 			break;
 		case WLAN_EID_WPA:
 			if (elen >= 4 && pos[0] == 0x00 && pos[1] == 0x50 &&
 			    pos[2] == 0xf2) {
 				/* Microsoft OUI (00:50:F2) */
 				if (pos[3] == 1) {
 					/* OUI Type 1 - WPA IE */
 					elems->wpa = pos;
 					elems->wpa_len = elen;
 				} else if (elen >= 5 && pos[3] == 2) {
 					if (pos[4] == 0) {
 						elems->wmm_info = pos;
 						elems->wmm_info_len = elen;
 					} else if (pos[4] == 1) {
 						elems->wmm_param = pos;
 						elems->wmm_param_len = elen;
 					}
 				}
 			}
 			break;
 		case WLAN_EID_RSN:
 			elems->rsn = pos;
 			elems->rsn_len = elen;
 			break;
 		case WLAN_EID_ERP_INFO:
 			elems->erp_info = pos;
 			elems->erp_info_len = elen;
 			break;
 		case WLAN_EID_EXT_SUPP_RATES:
 			elems->ext_supp_rates = pos;
 			elems->ext_supp_rates_len = elen;
 			break;
 		case WLAN_EID_HT_CAPABILITY:
 			elems->ht_cap_elem = pos;
 			elems->ht_cap_elem_len = elen;
 			break;
 		case WLAN_EID_HT_EXTRA_INFO:
 			elems->ht_info_elem = pos;
 			elems->ht_info_elem_len = elen;
 			break;
 		case WLAN_EID_MESH_ID:
 			elems->mesh_id = pos;
 			elems->mesh_id_len = elen;
 			break;
 		case WLAN_EID_MESH_CONFIG:
 			elems->mesh_config = pos;
 			elems->mesh_config_len = elen;
 			break;
 		case WLAN_EID_PEER_LINK:
 			elems->peer_link = pos;
 			elems->peer_link_len = elen;
 			break;
 		case WLAN_EID_PREQ:
 			elems->preq = pos;
 			elems->preq_len = elen;
 			break;
 		case WLAN_EID_PREP:
 			elems->prep = pos;
 			elems->prep_len = elen;
 			break;
 		case WLAN_EID_PERR:
 			elems->perr = pos;
 			elems->perr_len = elen;
 			break;
 		case WLAN_EID_CHANNEL_SWITCH:
 			elems->ch_switch_elem = pos;
 			elems->ch_switch_elem_len = elen;
 			break;
 		case WLAN_EID_QUIET:
 			if (!elems->quiet_elem) {
 				elems->quiet_elem = pos;
 				elems->quiet_elem_len = elen;
 			}
 			elems->num_of_quiet_elem++;
 			break;
 		case WLAN_EID_COUNTRY:
 			elems->country_elem = pos;
 			elems->country_elem_len = elen;
 			break;
 		case WLAN_EID_PWR_CONSTRAINT:
 			elems->pwr_constr_elem = pos;
 			elems->pwr_constr_elem_len = elen;
 			break;
 		default:
 			break;
 		}

 		left -= elen;
 		pos += elen;
 	}
 }

 void ieee80211_set_wmm_default(struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_tx_queue_params qparam;
 	int i;

 	if (!local->ops->conf_tx)
 		return;

 	memset(&qparam, 0, sizeof(qparam));

 	qparam.aifs = 2;

 	if (local->hw.conf.channel->band == IEEE80211_BAND_2GHZ &&
 	    !(sdata->flags & IEEE80211_SDATA_OPERATING_GMODE))
 		qparam.cw_min = 31;
 	else
 		qparam.cw_min = 15;

 	qparam.cw_max = 1023;
 	qparam.txop = 0;

 	for (i = 0; i < local_to_hw(local)->queues; i++)
 		local->ops->conf_tx(local_to_hw(local), i, &qparam);
 }

 void ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
 		      int encrypt)
 {
 	skb->dev = sdata->local->mdev;
 	skb_set_mac_header(skb, 0);
 	skb_set_network_header(skb, 0);
 	skb_set_transport_header(skb, 0);

 	skb->iif = sdata->dev->ifindex;
 	skb->do_not_encrypt = !encrypt;

 	dev_queue_xmit(skb);
 }

 int ieee80211_set_freq(struct ieee80211_sub_if_data *sdata, int freqMHz)
 {
 	int ret = -EINVAL;
 	struct ieee80211_channel *chan;
 	struct ieee80211_local *local = sdata->local;

 	chan = ieee80211_get_channel(local->hw.wiphy, freqMHz);

 	if (chan && !(chan->flags & IEEE80211_CHAN_DISABLED)) {
 		if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
 		    chan->flags & IEEE80211_CHAN_NO_IBSS) {
 			printk(KERN_DEBUG "%s: IBSS not allowed on frequency "
 				"%d MHz\n", sdata->dev->name, chan->center_freq);
 			return ret;
 		}
 		local->oper_channel = chan;

 		if (local->sw_scanning || local->hw_scanning)
 			ret = 0;
 		else
 			ret = ieee80211_hw_config(local);

 		rate_control_clear(local);
 	}

 	return ret;
 }

 u64 ieee80211_mandatory_rates(struct ieee80211_local *local,
 			      enum ieee80211_band band)
 {
 	struct ieee80211_supported_band *sband;
 	struct ieee80211_rate *bitrates;
 	u64 mandatory_rates;
 	enum ieee80211_rate_flags mandatory_flag;
 	int i;

 	sband = local->hw.wiphy->bands[band];
 	if (!sband) {
 		WARN_ON(1);
 		sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
 	}

 	if (band == IEEE80211_BAND_2GHZ)
 		mandatory_flag = IEEE80211_RATE_MANDATORY_B;
 	else
 		mandatory_flag = IEEE80211_RATE_MANDATORY_A;

 	bitrates = sband->bitrates;
 	mandatory_rates = 0;
 	for (i = 0; i < sband->n_bitrates; i++)
 		if (bitrates[i].flags & mandatory_flag)
 			mandatory_rates |= BIT(i);
 	return mandatory_rates;
 }
	/*
	* Copyright 2002-2005, Instant802 Networks, Inc.
	* Copyright 2005-2006, Devicescape Software, Inc.
	* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
	* Copyright 2007 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.
	*
	* utilities for mac80211
	*/

	#include <net/mac80211.h>
	#include <linux/netdevice.h>
	#include <linux/types.h>
	#include <linux/slab.h>
	#include <linux/skbuff.h>
	#include <linux/etherdevice.h>
	#include <linux/if_arp.h>
	#include <linux/wireless.h>
	#include <linux/bitmap.h>
	#include <net/net_namespace.h>
	#include <net/cfg80211.h>
	#include <net/rtnetlink.h>

	#include "ieee80211_i.h"
	#include "rate.h"
	#include "mesh.h"
	#include "wme.h"

	/* privid for wiphys to determine whether they belong to us or not */
	void *mac80211_wiphy_privid = &mac80211_wiphy_privid;

	/* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
	/* Ethernet-II snap header (RFC1042 for most EtherTypes) */
	const unsigned char rfc1042_header[] __aligned(2) =
	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };

	/* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
	const unsigned char bridge_tunnel_header[] __aligned(2) =
	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };


	u8 ieee80211_get_bssid(struct ieee80211_hdr hdr, size_t len,
	enum nl80211_iftype type)
	{
	__le16 fc = hdr->frame_control;

	/* drop ACK/CTS frames and incorrect hdr len (ctrl) */
	if (len < 16)
	return NULL;

	if (ieee80211_is_data(fc)) {
	if (len < 24) /* drop incorrect hdr len (data) */
	return NULL;

	if (ieee80211_has_a4(fc))
	return NULL;
	if (ieee80211_has_tods(fc))
	return hdr->addr1;
	if (ieee80211_has_fromds(fc))
	return hdr->addr2;

	return hdr->addr3;
	}

	if (ieee80211_is_mgmt(fc)) {
	if (len < 24) /* drop incorrect hdr len (mgmt) */
	return NULL;
	return hdr->addr3;
	}

	if (ieee80211_is_ctl(fc)) {
	if(ieee80211_is_pspoll(fc))
	return hdr->addr1;

	if (ieee80211_is_back_req(fc)) {
	switch (type) {
	case NL80211_IFTYPE_STATION:
	return hdr->addr2;
	case NL80211_IFTYPE_AP:
	case NL80211_IFTYPE_AP_VLAN:
	return hdr->addr1;
	default:
	break; /* fall through to the return */
	}
	}
	}

	return NULL;
	}

	unsigned int ieee80211_hdrlen(__le16 fc)
	{
	unsigned int hdrlen = 24;

	if (ieee80211_is_data(fc)) {
	if (ieee80211_has_a4(fc))
	hdrlen = 30;
	if (ieee80211_is_data_qos(fc))
	hdrlen += IEEE80211_QOS_CTL_LEN;
	goto out;
	}

	if (ieee80211_is_ctl(fc)) {
	/*
	* ACK and CTS are 10 bytes, all others 16. To see how
	* to get this condition consider
	* subtype mask: 0b0000000011110000 (0x00F0)
	* ACK subtype: 0b0000000011010000 (0x00D0)
	* CTS subtype: 0b0000000011000000 (0x00C0)
	* bits that matter: ^^^ (0x00E0)
	* value of those: 0b0000000011000000 (0x00C0)
	*/
	if ((fc & cpu_to_le16(0x00E0)) == cpu_to_le16(0x00C0))
	hdrlen = 10;
	else
	hdrlen = 16;
	}
	out:
	return hdrlen;
	}
	EXPORT_SYMBOL(ieee80211_hdrlen);

	unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
	{
	const struct ieee80211_hdr hdr = (const struct ieee80211_hdr )skb->data;
	unsigned int hdrlen;

	if (unlikely(skb->len < 10))
	return 0;
	hdrlen = ieee80211_hdrlen(hdr->frame_control);
	if (unlikely(hdrlen > skb->len))
	return 0;
	return hdrlen;
	}
	EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);

	int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
	{
	int ae = meshhdr->flags & IEEE80211S_FLAGS_AE;
	/* 7.1.3.5a.2 */
	switch (ae) {
	case 0:
	return 6;
	case 1:
	return 12;
	case 2:
	return 18;
	case 3:
	return 24;
	default:
	return 6;
	}
	}

	void ieee80211_tx_set_protected(struct ieee80211_tx_data *tx)
	{
	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) tx->skb->data;

	hdr->frame_control \|= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
	if (tx->extra_frag) {
	struct ieee80211_hdr *fhdr;
	int i;
	for (i = 0; i < tx->num_extra_frag; i++) {
	fhdr = (struct ieee80211_hdr *)
	tx->extra_frag[i]->data;
	fhdr->frame_control \|= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
	}
	}
	}

	int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
	int rate, int erp, int short_preamble)
	{
	int dur;

	/* calculate duration (in microseconds, rounded up to next higher
	* integer if it includes a fractional microsecond) to send frame of
	* len bytes (does not include FCS) at the given rate. Duration will
	* also include SIFS.
	*
	* rate is in 100 kbps, so divident is multiplied by 10 in the
	* DIV_ROUND_UP() operations.
	*/

	if (local->hw.conf.channel->band == IEEE80211_BAND_5GHZ \|\| erp) {
	/*
	* OFDM:
	*
	* N_DBPS = DATARATE x 4
	* N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS)
	* (16 = SIGNAL time, 6 = tail bits)
	* TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext
	*
	* T_SYM = 4 usec
	* 802.11a - 17.5.2: aSIFSTime = 16 usec
	* 802.11g - 19.8.4: aSIFSTime = 10 usec +
	* signal ext = 6 usec
	*/
	dur = 16; /* SIFS + signal ext */
	dur += 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */
	dur += 4; /* 17.3.2.3: T_SIGNAL = 4 usec */
	dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10,
	4 * rate); /* T_SYM x N_SYM */
	} else {
	/*
	* 802.11b or 802.11g with 802.11b compatibility:
	* 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime +
	* Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0.
	*
	* 802.11 (DS): 15.3.3, 802.11b: 18.3.4
	* aSIFSTime = 10 usec
	* aPreambleLength = 144 usec or 72 usec with short preamble
	* aPLCPHeaderLength = 48 usec or 24 usec with short preamble
	*/
	dur = 10; /* aSIFSTime = 10 usec */
	dur += short_preamble ? (72 + 24) : (144 + 48);

	dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate);
	}

	return dur;
	}

	/* Exported duration function for driver use */
	__le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw,
	struct ieee80211_vif *vif,
	size_t frame_len,
	struct ieee80211_rate *rate)
	{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_sub_if_data *sdata;
	u16 dur;
	int erp;
	bool short_preamble = false;

	erp = 0;
	if (vif) {
	sdata = vif_to_sdata(vif);
	short_preamble = sdata->bss_conf.use_short_preamble;
	if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
	erp = rate->flags & IEEE80211_RATE_ERP_G;
	}

	dur = ieee80211_frame_duration(local, frame_len, rate->bitrate, erp,
	short_preamble);

	return cpu_to_le16(dur);
	}
	EXPORT_SYMBOL(ieee80211_generic_frame_duration);

	__le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
	struct ieee80211_vif *vif, size_t frame_len,
	const struct ieee80211_tx_info *frame_txctl)
	{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_rate *rate;
	struct ieee80211_sub_if_data *sdata;
	bool short_preamble;
	int erp;
	u16 dur;
	struct ieee80211_supported_band *sband;

	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];

	short_preamble = false;

	rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];

	erp = 0;
	if (vif) {
	sdata = vif_to_sdata(vif);
	short_preamble = sdata->bss_conf.use_short_preamble;
	if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
	erp = rate->flags & IEEE80211_RATE_ERP_G;
	}

	/* CTS duration */
	dur = ieee80211_frame_duration(local, 10, rate->bitrate,
	erp, short_preamble);
	/* Data frame duration */
	dur += ieee80211_frame_duration(local, frame_len, rate->bitrate,
	erp, short_preamble);
	/* ACK duration */
	dur += ieee80211_frame_duration(local, 10, rate->bitrate,
	erp, short_preamble);

	return cpu_to_le16(dur);
	}
	EXPORT_SYMBOL(ieee80211_rts_duration);

	__le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
	struct ieee80211_vif *vif,
	size_t frame_len,
	const struct ieee80211_tx_info *frame_txctl)
	{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_rate *rate;
	struct ieee80211_sub_if_data *sdata;
	bool short_preamble;
	int erp;
	u16 dur;
	struct ieee80211_supported_band *sband;

	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];

	short_preamble = false;

	rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];
	erp = 0;
	if (vif) {
	sdata = vif_to_sdata(vif);
	short_preamble = sdata->bss_conf.use_short_preamble;
	if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
	erp = rate->flags & IEEE80211_RATE_ERP_G;
	}

	/* Data frame duration */
	dur = ieee80211_frame_duration(local, frame_len, rate->bitrate,
	erp, short_preamble);
	if (!(frame_txctl->flags & IEEE80211_TX_CTL_NO_ACK)) {
	/* ACK duration */
	dur += ieee80211_frame_duration(local, 10, rate->bitrate,
	erp, short_preamble);
	}

	return cpu_to_le16(dur);
	}
	EXPORT_SYMBOL(ieee80211_ctstoself_duration);

	void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue)
	{
	struct ieee80211_local *local = hw_to_local(hw);

	if (test_bit(queue, local->queues_pending)) {
	set_bit(queue, local->queues_pending_run);
	tasklet_schedule(&local->tx_pending_tasklet);
	} else {
	netif_wake_subqueue(local->mdev, queue);
	}
	}
	EXPORT_SYMBOL(ieee80211_wake_queue);

	void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue)
	{
	struct ieee80211_local *local = hw_to_local(hw);

	netif_stop_subqueue(local->mdev, queue);
	}
	EXPORT_SYMBOL(ieee80211_stop_queue);

	void ieee80211_stop_queues(struct ieee80211_hw *hw)
	{
	int i;

	for (i = 0; i < ieee80211_num_queues(hw); i++)
	ieee80211_stop_queue(hw, i);
	}
	EXPORT_SYMBOL(ieee80211_stop_queues);

	int ieee80211_queue_stopped(struct ieee80211_hw *hw, int queue)
	{
	struct ieee80211_local *local = hw_to_local(hw);
	return __netif_subqueue_stopped(local->mdev, queue);
	}
	EXPORT_SYMBOL(ieee80211_queue_stopped);

	void ieee80211_wake_queues(struct ieee80211_hw *hw)
	{
	int i;

	for (i = 0; i < hw->queues + hw->ampdu_queues; i++)
	ieee80211_wake_queue(hw, i);
	}
	EXPORT_SYMBOL(ieee80211_wake_queues);

	void ieee80211_iterate_active_interfaces(
	struct ieee80211_hw *hw,
	void (iterator)(void data, u8 *mac,
	struct ieee80211_vif *vif),
	void *data)
	{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_sub_if_data *sdata;

	rtnl_lock();

	list_for_each_entry(sdata, &local->interfaces, list) {
	switch (sdata->vif.type) {
	case __NL80211_IFTYPE_AFTER_LAST:
	case NL80211_IFTYPE_UNSPECIFIED:
	case NL80211_IFTYPE_MONITOR:
	case NL80211_IFTYPE_AP_VLAN:
	continue;
	case NL80211_IFTYPE_AP:
	case NL80211_IFTYPE_STATION:
	case NL80211_IFTYPE_ADHOC:
	case NL80211_IFTYPE_WDS:
	case NL80211_IFTYPE_MESH_POINT:
	break;
	}
	if (netif_running(sdata->dev))
	iterator(data, sdata->dev->dev_addr,
	&sdata->vif);
	}

	rtnl_unlock();
	}
	EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);

	void ieee80211_iterate_active_interfaces_atomic(
	struct ieee80211_hw *hw,
	void (iterator)(void data, u8 *mac,
	struct ieee80211_vif *vif),
	void *data)
	{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_sub_if_data *sdata;

	rcu_read_lock();

	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
	switch (sdata->vif.type) {
	case __NL80211_IFTYPE_AFTER_LAST:
	case NL80211_IFTYPE_UNSPECIFIED:
	case NL80211_IFTYPE_MONITOR:
	case NL80211_IFTYPE_AP_VLAN:
	continue;
	case NL80211_IFTYPE_AP:
	case NL80211_IFTYPE_STATION:
	case NL80211_IFTYPE_ADHOC:
	case NL80211_IFTYPE_WDS:
	case NL80211_IFTYPE_MESH_POINT:
	break;
	}
	if (netif_running(sdata->dev))
	iterator(data, sdata->dev->dev_addr,
	&sdata->vif);
	}

	rcu_read_unlock();
	}
	EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces_atomic);

	void ieee802_11_parse_elems(u8 *start, size_t len,
	struct ieee802_11_elems *elems)
	{
	size_t left = len;
	u8 *pos = start;

	memset(elems, 0, sizeof(*elems));
	elems->ie_start = start;
	elems->total_len = len;

	while (left >= 2) {
	u8 id, elen;

	id = *pos++;
	elen = *pos++;
	left -= 2;

	if (elen > left)
	return;

	switch (id) {
	case WLAN_EID_SSID:
	elems->ssid = pos;
	elems->ssid_len = elen;
	break;
	case WLAN_EID_SUPP_RATES:
	elems->supp_rates = pos;
	elems->supp_rates_len = elen;
	break;
	case WLAN_EID_FH_PARAMS:
	elems->fh_params = pos;
	elems->fh_params_len = elen;
	break;
	case WLAN_EID_DS_PARAMS:
	elems->ds_params = pos;
	elems->ds_params_len = elen;
	break;
	case WLAN_EID_CF_PARAMS:
	elems->cf_params = pos;
	elems->cf_params_len = elen;
	break;
	case WLAN_EID_TIM:
	elems->tim = pos;
	elems->tim_len = elen;
	break;
	case WLAN_EID_IBSS_PARAMS:
	elems->ibss_params = pos;
	elems->ibss_params_len = elen;
	break;
	case WLAN_EID_CHALLENGE:
	elems->challenge = pos;
	elems->challenge_len = elen;
	break;
	case WLAN_EID_WPA:
	if (elen >= 4 && pos[0] == 0x00 && pos[1] == 0x50 &&
	pos[2] == 0xf2) {
	/* Microsoft OUI (00:50:F2) */
	if (pos[3] == 1) {
	/* OUI Type 1 - WPA IE */
	elems->wpa = pos;
	elems->wpa_len = elen;
	} else if (elen >= 5 && pos[3] == 2) {
	if (pos[4] == 0) {
	elems->wmm_info = pos;
	elems->wmm_info_len = elen;
	} else if (pos[4] == 1) {
	elems->wmm_param = pos;
	elems->wmm_param_len = elen;
	}
	}
	}
	break;
	case WLAN_EID_RSN:
	elems->rsn = pos;
	elems->rsn_len = elen;
	break;
	case WLAN_EID_ERP_INFO:
	elems->erp_info = pos;
	elems->erp_info_len = elen;
	break;
	case WLAN_EID_EXT_SUPP_RATES:
	elems->ext_supp_rates = pos;
	elems->ext_supp_rates_len = elen;
	break;
	case WLAN_EID_HT_CAPABILITY:
	elems->ht_cap_elem = pos;
	elems->ht_cap_elem_len = elen;
	break;
	case WLAN_EID_HT_EXTRA_INFO:
	elems->ht_info_elem = pos;
	elems->ht_info_elem_len = elen;
	break;
	case WLAN_EID_MESH_ID:
	elems->mesh_id = pos;
	elems->mesh_id_len = elen;
	break;
	case WLAN_EID_MESH_CONFIG:
	elems->mesh_config = pos;
	elems->mesh_config_len = elen;
	break;
	case WLAN_EID_PEER_LINK:
	elems->peer_link = pos;
	elems->peer_link_len = elen;
	break;
	case WLAN_EID_PREQ:
	elems->preq = pos;
	elems->preq_len = elen;
	break;
	case WLAN_EID_PREP:
	elems->prep = pos;
	elems->prep_len = elen;
	break;
	case WLAN_EID_PERR:
	elems->perr = pos;
	elems->perr_len = elen;
	break;
	case WLAN_EID_CHANNEL_SWITCH:
	elems->ch_switch_elem = pos;
	elems->ch_switch_elem_len = elen;
	break;
	case WLAN_EID_QUIET:
	if (!elems->quiet_elem) {
	elems->quiet_elem = pos;
	elems->quiet_elem_len = elen;
	}
	elems->num_of_quiet_elem++;
	break;
	case WLAN_EID_COUNTRY:
	elems->country_elem = pos;
	elems->country_elem_len = elen;
	break;
	case WLAN_EID_PWR_CONSTRAINT:
	elems->pwr_constr_elem = pos;
	elems->pwr_constr_elem_len = elen;
	break;
	default:
	break;
	}

	left -= elen;
	pos += elen;
	}
	}

	void ieee80211_set_wmm_default(struct ieee80211_sub_if_data *sdata)
	{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_tx_queue_params qparam;
	int i;

	if (!local->ops->conf_tx)
	return;

	memset(&qparam, 0, sizeof(qparam));

	qparam.aifs = 2;

	if (local->hw.conf.channel->band == IEEE80211_BAND_2GHZ &&
	!(sdata->flags & IEEE80211_SDATA_OPERATING_GMODE))
	qparam.cw_min = 31;
	else
	qparam.cw_min = 15;

	qparam.cw_max = 1023;
	qparam.txop = 0;

	for (i = 0; i < local_to_hw(local)->queues; i++)
	local->ops->conf_tx(local_to_hw(local), i, &qparam);
	}

	void ieee80211_tx_skb(struct ieee80211_sub_if_data sdata, struct sk_buff skb,
	int encrypt)
	{
	skb->dev = sdata->local->mdev;
	skb_set_mac_header(skb, 0);
	skb_set_network_header(skb, 0);
	skb_set_transport_header(skb, 0);

	skb->iif = sdata->dev->ifindex;
	skb->do_not_encrypt = !encrypt;

	dev_queue_xmit(skb);
	}

	int ieee80211_set_freq(struct ieee80211_sub_if_data *sdata, int freqMHz)
	{
	int ret = -EINVAL;
	struct ieee80211_channel *chan;
	struct ieee80211_local *local = sdata->local;

	chan = ieee80211_get_channel(local->hw.wiphy, freqMHz);

	if (chan && !(chan->flags & IEEE80211_CHAN_DISABLED)) {
	if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
	chan->flags & IEEE80211_CHAN_NO_IBSS) {
	printk(KERN_DEBUG "%s: IBSS not allowed on frequency "
	"%d MHz\n", sdata->dev->name, chan->center_freq);
	return ret;
	}
	local->oper_channel = chan;

	if (local->sw_scanning \|\| local->hw_scanning)
	ret = 0;
	else
	ret = ieee80211_hw_config(local);

	rate_control_clear(local);
	}

	return ret;
	}

	u64 ieee80211_mandatory_rates(struct ieee80211_local *local,
	enum ieee80211_band band)
	{
	struct ieee80211_supported_band *sband;
	struct ieee80211_rate *bitrates;
	u64 mandatory_rates;
	enum ieee80211_rate_flags mandatory_flag;
	int i;

	sband = local->hw.wiphy->bands[band];
	if (!sband) {
	WARN_ON(1);
	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
	}

	if (band == IEEE80211_BAND_2GHZ)
	mandatory_flag = IEEE80211_RATE_MANDATORY_B;
	else
	mandatory_flag = IEEE80211_RATE_MANDATORY_A;

	bitrates = sband->bitrates;
	mandatory_rates = 0;
	for (i = 0; i < sband->n_bitrates; i++)
	if (bitrates[i].flags & mandatory_flag)
	mandatory_rates \|= BIT(i);
	return mandatory_rates;
	}