/*
   * Wireless utility functions
   *

   * Copyright 2007-2009	Johannes Berg <johannes@sipsolutions.net>

   */

  #include <linux/export.h>

  #include <linux/bitops.h>

  #include <linux/etherdevice.h>

  #include <linux/slab.h>

  #include <net/cfg80211.h>

  #include <net/ip.h>

  #include <net/dsfield.h>

  #include "core.h"

  struct ieee80211_rate *
  ieee80211_get_response_rate(struct ieee80211_supported_band *sband,

  			    u32 basic_rates, int bitrate)

  {
  	struct ieee80211_rate *result = &sband->bitrates[0];
  	int i;
  
  	for (i = 0; i < sband->n_bitrates; i++) {
  		if (!(basic_rates & BIT(i)))
  			continue;
  		if (sband->bitrates[i].bitrate > bitrate)
  			continue;
  		result = &sband->bitrates[i];
  	}
  
  	return result;
  }
  EXPORT_SYMBOL(ieee80211_get_response_rate);

  int ieee80211_channel_to_frequency(int chan, enum ieee80211_band band)

  {

  	/* see 802.11 17.3.8.3.2 and Annex J
  	 * there are overlapping channel numbers in 5GHz and 2GHz bands */
  	if (band == IEEE80211_BAND_5GHZ) {
  		if (chan >= 182 && chan <= 196)
  			return 4000 + chan * 5;
  		else
  			return 5000 + chan * 5;
  	} else { /* IEEE80211_BAND_2GHZ */
  		if (chan == 14)
  			return 2484;
  		else if (chan < 14)
  			return 2407 + chan * 5;
  		else
  			return 0; /* not supported */
  	}

  }
  EXPORT_SYMBOL(ieee80211_channel_to_frequency);
  
  int ieee80211_frequency_to_channel(int freq)
  {

  	/* see 802.11 17.3.8.3.2 and Annex J */

  	if (freq == 2484)
  		return 14;

  	else if (freq < 2484)

  		return (freq - 2407) / 5;

  	else if (freq >= 4910 && freq <= 4980)
  		return (freq - 4000) / 5;
  	else
  		return (freq - 5000) / 5;

  }
  EXPORT_SYMBOL(ieee80211_frequency_to_channel);

  struct ieee80211_channel *__ieee80211_get_channel(struct wiphy *wiphy,
  						  int freq)

  {
  	enum ieee80211_band band;
  	struct ieee80211_supported_band *sband;
  	int i;
  
  	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
  		sband = wiphy->bands[band];
  
  		if (!sband)
  			continue;
  
  		for (i = 0; i < sband->n_channels; i++) {
  			if (sband->channels[i].center_freq == freq)
  				return &sband->channels[i];
  		}
  	}
  
  	return NULL;
  }

  EXPORT_SYMBOL(__ieee80211_get_channel);

  static void set_mandatory_flags_band(struct ieee80211_supported_band *sband,
  				     enum ieee80211_band band)
  {
  	int i, want;
  
  	switch (band) {
  	case IEEE80211_BAND_5GHZ:
  		want = 3;
  		for (i = 0; i < sband->n_bitrates; i++) {
  			if (sband->bitrates[i].bitrate == 60 ||
  			    sband->bitrates[i].bitrate == 120 ||
  			    sband->bitrates[i].bitrate == 240) {
  				sband->bitrates[i].flags |=
  					IEEE80211_RATE_MANDATORY_A;
  				want--;
  			}
  		}
  		WARN_ON(want);
  		break;
  	case IEEE80211_BAND_2GHZ:
  		want = 7;
  		for (i = 0; i < sband->n_bitrates; i++) {
  			if (sband->bitrates[i].bitrate == 10) {
  				sband->bitrates[i].flags |=
  					IEEE80211_RATE_MANDATORY_B |
  					IEEE80211_RATE_MANDATORY_G;
  				want--;
  			}
  
  			if (sband->bitrates[i].bitrate == 20 ||
  			    sband->bitrates[i].bitrate == 55 ||
  			    sband->bitrates[i].bitrate == 110 ||
  			    sband->bitrates[i].bitrate == 60 ||
  			    sband->bitrates[i].bitrate == 120 ||
  			    sband->bitrates[i].bitrate == 240) {
  				sband->bitrates[i].flags |=
  					IEEE80211_RATE_MANDATORY_G;
  				want--;
  			}

  			if (sband->bitrates[i].bitrate != 10 &&
  			    sband->bitrates[i].bitrate != 20 &&
  			    sband->bitrates[i].bitrate != 55 &&
  			    sband->bitrates[i].bitrate != 110)

  				sband->bitrates[i].flags |=
  					IEEE80211_RATE_ERP_G;
  		}

  		WARN_ON(want != 0 && want != 3 && want != 6);

  		break;
  	case IEEE80211_NUM_BANDS:
  		WARN_ON(1);
  		break;
  	}
  }
  
  void ieee80211_set_bitrate_flags(struct wiphy *wiphy)
  {
  	enum ieee80211_band band;
  
  	for (band = 0; band < IEEE80211_NUM_BANDS; band++)
  		if (wiphy->bands[band])
  			set_mandatory_flags_band(wiphy->bands[band], band);
  }

  bool cfg80211_supported_cipher_suite(struct wiphy *wiphy, u32 cipher)
  {
  	int i;
  	for (i = 0; i < wiphy->n_cipher_suites; i++)
  		if (cipher == wiphy->cipher_suites[i])
  			return true;
  	return false;
  }

  int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,
  				   struct key_params *params, int key_idx,

  				   bool pairwise, const u8 *mac_addr)

  {
  	if (key_idx > 5)
  		return -EINVAL;

  	if (!pairwise && mac_addr && !(rdev->wiphy.flags & WIPHY_FLAG_IBSS_RSN))
  		return -EINVAL;
  
  	if (pairwise && !mac_addr)
  		return -EINVAL;

  	/*
  	 * Disallow pairwise keys with non-zero index unless it's WEP

  	 * or a vendor specific cipher (because current deployments use
  	 * pairwise WEP keys with non-zero indices and for vendor specific
  	 * ciphers this should be validated in the driver or hardware level
  	 * - but 802.11i clearly specifies to use zero)

  	 */

  	if (pairwise && key_idx &&

  	    ((params->cipher == WLAN_CIPHER_SUITE_TKIP) ||
  	     (params->cipher == WLAN_CIPHER_SUITE_CCMP) ||
  	     (params->cipher == WLAN_CIPHER_SUITE_AES_CMAC)))

  		return -EINVAL;

  	switch (params->cipher) {
  	case WLAN_CIPHER_SUITE_WEP40:

  		if (params->key_len != WLAN_KEY_LEN_WEP40)

  			return -EINVAL;
  		break;
  	case WLAN_CIPHER_SUITE_TKIP:

  		if (params->key_len != WLAN_KEY_LEN_TKIP)

  			return -EINVAL;
  		break;
  	case WLAN_CIPHER_SUITE_CCMP:

  		if (params->key_len != WLAN_KEY_LEN_CCMP)

  			return -EINVAL;
  		break;
  	case WLAN_CIPHER_SUITE_WEP104:

  		if (params->key_len != WLAN_KEY_LEN_WEP104)

  			return -EINVAL;
  		break;
  	case WLAN_CIPHER_SUITE_AES_CMAC:

  		if (params->key_len != WLAN_KEY_LEN_AES_CMAC)

  			return -EINVAL;
  		break;
  	default:

  		/*
  		 * We don't know anything about this algorithm,
  		 * allow using it -- but the driver must check
  		 * all parameters! We still check below whether
  		 * or not the driver supports this algorithm,
  		 * of course.
  		 */
  		break;

  	}

  	if (params->seq) {
  		switch (params->cipher) {
  		case WLAN_CIPHER_SUITE_WEP40:
  		case WLAN_CIPHER_SUITE_WEP104:
  			/* These ciphers do not use key sequence */
  			return -EINVAL;
  		case WLAN_CIPHER_SUITE_TKIP:
  		case WLAN_CIPHER_SUITE_CCMP:
  		case WLAN_CIPHER_SUITE_AES_CMAC:
  			if (params->seq_len != 6)
  				return -EINVAL;
  			break;
  		}
  	}

  	if (!cfg80211_supported_cipher_suite(&rdev->wiphy, params->cipher))

  		return -EINVAL;

  	return 0;
  }

  unsigned int __attribute_const__ 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;

  			if (ieee80211_has_order(fc))
  				hdrlen += IEEE80211_HT_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);

  static int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)

  {
  	int ae = meshhdr->flags & MESH_FLAGS_AE;
  	/* 7.1.3.5a.2 */
  	switch (ae) {
  	case 0:
  		return 6;

  	case MESH_FLAGS_AE_A4:

  		return 12;

  	case MESH_FLAGS_AE_A5_A6:

  		return 18;

  	case (MESH_FLAGS_AE_A4 | MESH_FLAGS_AE_A5_A6):

  		return 24;
  	default:
  		return 6;
  	}
  }

  int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,

  			   enum nl80211_iftype iftype)
  {
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
  	u16 hdrlen, ethertype;
  	u8 *payload;
  	u8 dst[ETH_ALEN];
  	u8 src[ETH_ALEN] __aligned(2);
  
  	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
  		return -1;
  
  	hdrlen = ieee80211_hdrlen(hdr->frame_control);
  
  	/* convert IEEE 802.11 header + possible LLC headers into Ethernet
  	 * header
  	 * IEEE 802.11 address fields:
  	 * ToDS FromDS Addr1 Addr2 Addr3 Addr4
  	 *   0     0   DA    SA    BSSID n/a
  	 *   0     1   DA    BSSID SA    n/a
  	 *   1     0   BSSID SA    DA    n/a
  	 *   1     1   RA    TA    DA    SA
  	 */
  	memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
  	memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
  
  	switch (hdr->frame_control &
  		cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
  	case cpu_to_le16(IEEE80211_FCTL_TODS):
  		if (unlikely(iftype != NL80211_IFTYPE_AP &&

  			     iftype != NL80211_IFTYPE_AP_VLAN &&
  			     iftype != NL80211_IFTYPE_P2P_GO))

  			return -1;
  		break;
  	case cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
  		if (unlikely(iftype != NL80211_IFTYPE_WDS &&

  			     iftype != NL80211_IFTYPE_MESH_POINT &&
  			     iftype != NL80211_IFTYPE_AP_VLAN &&
  			     iftype != NL80211_IFTYPE_STATION))

  			return -1;
  		if (iftype == NL80211_IFTYPE_MESH_POINT) {
  			struct ieee80211s_hdr *meshdr =
  				(struct ieee80211s_hdr *) (skb->data + hdrlen);

  			/* make sure meshdr->flags is on the linear part */
  			if (!pskb_may_pull(skb, hdrlen + 1))
  				return -1;

  			if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {

  				skb_copy_bits(skb, hdrlen +
  					offsetof(struct ieee80211s_hdr, eaddr1),
  				       	dst, ETH_ALEN);
  				skb_copy_bits(skb, hdrlen +
  					offsetof(struct ieee80211s_hdr, eaddr2),
  				        src, ETH_ALEN);

  			}

  			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);

  		}
  		break;
  	case cpu_to_le16(IEEE80211_FCTL_FROMDS):

  		if ((iftype != NL80211_IFTYPE_STATION &&

  		     iftype != NL80211_IFTYPE_P2P_CLIENT &&
  		     iftype != NL80211_IFTYPE_MESH_POINT) ||

  		    (is_multicast_ether_addr(dst) &&
  		     !compare_ether_addr(src, addr)))
  			return -1;

  		if (iftype == NL80211_IFTYPE_MESH_POINT) {
  			struct ieee80211s_hdr *meshdr =
  				(struct ieee80211s_hdr *) (skb->data + hdrlen);

  			/* make sure meshdr->flags is on the linear part */
  			if (!pskb_may_pull(skb, hdrlen + 1))
  				return -1;

  			if (meshdr->flags & MESH_FLAGS_AE_A4)

  				skb_copy_bits(skb, hdrlen +
  					offsetof(struct ieee80211s_hdr, eaddr1),
  					src, ETH_ALEN);
  			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);

  		}

  		break;
  	case cpu_to_le16(0):

  		if (iftype != NL80211_IFTYPE_ADHOC &&
  		    iftype != NL80211_IFTYPE_STATION)
  				return -1;

  		break;
  	}

  	if (!pskb_may_pull(skb, hdrlen + 8))

  		return -1;
  
  	payload = skb->data + hdrlen;
  	ethertype = (payload[6] << 8) | payload[7];
  
  	if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
  		    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
  		   compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
  		/* remove RFC1042 or Bridge-Tunnel encapsulation and
  		 * replace EtherType */
  		skb_pull(skb, hdrlen + 6);
  		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
  		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
  	} else {
  		struct ethhdr *ehdr;
  		__be16 len;
  
  		skb_pull(skb, hdrlen);
  		len = htons(skb->len);
  		ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
  		memcpy(ehdr->h_dest, dst, ETH_ALEN);
  		memcpy(ehdr->h_source, src, ETH_ALEN);
  		ehdr->h_proto = len;
  	}
  	return 0;
  }
  EXPORT_SYMBOL(ieee80211_data_to_8023);

  int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr,

  			     enum nl80211_iftype iftype, u8 *bssid, bool qos)
  {
  	struct ieee80211_hdr hdr;
  	u16 hdrlen, ethertype;
  	__le16 fc;
  	const u8 *encaps_data;
  	int encaps_len, skip_header_bytes;
  	int nh_pos, h_pos;
  	int head_need;
  
  	if (unlikely(skb->len < ETH_HLEN))
  		return -EINVAL;
  
  	nh_pos = skb_network_header(skb) - skb->data;
  	h_pos = skb_transport_header(skb) - skb->data;
  
  	/* convert Ethernet header to proper 802.11 header (based on
  	 * operation mode) */
  	ethertype = (skb->data[12] << 8) | skb->data[13];
  	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
  
  	switch (iftype) {
  	case NL80211_IFTYPE_AP:
  	case NL80211_IFTYPE_AP_VLAN:

  	case NL80211_IFTYPE_P2P_GO:

  		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
  		/* DA BSSID SA */
  		memcpy(hdr.addr1, skb->data, ETH_ALEN);
  		memcpy(hdr.addr2, addr, ETH_ALEN);
  		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
  		hdrlen = 24;
  		break;
  	case NL80211_IFTYPE_STATION:

  	case NL80211_IFTYPE_P2P_CLIENT:

  		fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
  		/* BSSID SA DA */
  		memcpy(hdr.addr1, bssid, ETH_ALEN);
  		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
  		memcpy(hdr.addr3, skb->data, ETH_ALEN);
  		hdrlen = 24;
  		break;
  	case NL80211_IFTYPE_ADHOC:
  		/* DA SA BSSID */
  		memcpy(hdr.addr1, skb->data, ETH_ALEN);
  		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
  		memcpy(hdr.addr3, bssid, ETH_ALEN);
  		hdrlen = 24;
  		break;
  	default:
  		return -EOPNOTSUPP;
  	}
  
  	if (qos) {
  		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
  		hdrlen += 2;
  	}
  
  	hdr.frame_control = fc;
  	hdr.duration_id = 0;
  	hdr.seq_ctrl = 0;
  
  	skip_header_bytes = ETH_HLEN;
  	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
  		encaps_data = bridge_tunnel_header;
  		encaps_len = sizeof(bridge_tunnel_header);
  		skip_header_bytes -= 2;
  	} else if (ethertype > 0x600) {
  		encaps_data = rfc1042_header;
  		encaps_len = sizeof(rfc1042_header);
  		skip_header_bytes -= 2;
  	} else {
  		encaps_data = NULL;
  		encaps_len = 0;
  	}
  
  	skb_pull(skb, skip_header_bytes);
  	nh_pos -= skip_header_bytes;
  	h_pos -= skip_header_bytes;
  
  	head_need = hdrlen + encaps_len - skb_headroom(skb);
  
  	if (head_need > 0 || skb_cloned(skb)) {
  		head_need = max(head_need, 0);
  		if (head_need)
  			skb_orphan(skb);

  		if (pskb_expand_head(skb, head_need, 0, GFP_ATOMIC))

  			return -ENOMEM;

  		skb->truesize += head_need;
  	}
  
  	if (encaps_data) {
  		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
  		nh_pos += encaps_len;
  		h_pos += encaps_len;
  	}
  
  	memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
  
  	nh_pos += hdrlen;
  	h_pos += hdrlen;
  
  	/* Update skb pointers to various headers since this modified frame
  	 * is going to go through Linux networking code that may potentially
  	 * need things like pointer to IP header. */
  	skb_set_mac_header(skb, 0);
  	skb_set_network_header(skb, nh_pos);
  	skb_set_transport_header(skb, h_pos);
  
  	return 0;
  }
  EXPORT_SYMBOL(ieee80211_data_from_8023);

  
  void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list,
  			      const u8 *addr, enum nl80211_iftype iftype,

  			      const unsigned int extra_headroom,
  			      bool has_80211_header)

  {
  	struct sk_buff *frame = NULL;
  	u16 ethertype;
  	u8 *payload;
  	const struct ethhdr *eth;
  	int remaining, err;
  	u8 dst[ETH_ALEN], src[ETH_ALEN];

  	if (has_80211_header) {
  		err = ieee80211_data_to_8023(skb, addr, iftype);
  		if (err)
  			goto out;

  		/* skip the wrapping header */
  		eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
  		if (!eth)
  			goto out;
  	} else {
  		eth = (struct ethhdr *) skb->data;
  	}

  
  	while (skb != frame) {
  		u8 padding;
  		__be16 len = eth->h_proto;
  		unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
  
  		remaining = skb->len;
  		memcpy(dst, eth->h_dest, ETH_ALEN);
  		memcpy(src, eth->h_source, ETH_ALEN);
  
  		padding = (4 - subframe_len) & 0x3;
  		/* the last MSDU has no padding */
  		if (subframe_len > remaining)
  			goto purge;
  
  		skb_pull(skb, sizeof(struct ethhdr));
  		/* reuse skb for the last subframe */
  		if (remaining <= subframe_len + padding)
  			frame = skb;
  		else {
  			unsigned int hlen = ALIGN(extra_headroom, 4);
  			/*
  			 * Allocate and reserve two bytes more for payload
  			 * alignment since sizeof(struct ethhdr) is 14.
  			 */
  			frame = dev_alloc_skb(hlen + subframe_len + 2);
  			if (!frame)
  				goto purge;
  
  			skb_reserve(frame, hlen + sizeof(struct ethhdr) + 2);
  			memcpy(skb_put(frame, ntohs(len)), skb->data,
  				ntohs(len));
  
  			eth = (struct ethhdr *)skb_pull(skb, ntohs(len) +
  							padding);
  			if (!eth) {
  				dev_kfree_skb(frame);
  				goto purge;
  			}
  		}
  
  		skb_reset_network_header(frame);
  		frame->dev = skb->dev;
  		frame->priority = skb->priority;
  
  		payload = frame->data;
  		ethertype = (payload[6] << 8) | payload[7];
  
  		if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
  			    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
  			   compare_ether_addr(payload,
  					      bridge_tunnel_header) == 0)) {
  			/* remove RFC1042 or Bridge-Tunnel
  			 * encapsulation and replace EtherType */
  			skb_pull(frame, 6);
  			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
  			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
  		} else {
  			memcpy(skb_push(frame, sizeof(__be16)), &len,
  				sizeof(__be16));
  			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
  			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
  		}
  		__skb_queue_tail(list, frame);
  	}
  
  	return;
  
   purge:
  	__skb_queue_purge(list);
   out:
  	dev_kfree_skb(skb);
  }
  EXPORT_SYMBOL(ieee80211_amsdu_to_8023s);

  /* Given a data frame determine the 802.1p/1d tag to use. */
  unsigned int cfg80211_classify8021d(struct sk_buff *skb)
  {
  	unsigned int dscp;
  
  	/* skb->priority values from 256->263 are magic values to
  	 * directly indicate a specific 802.1d priority.  This is used
  	 * to allow 802.1d priority to be passed directly in from VLAN
  	 * tags, etc.
  	 */
  	if (skb->priority >= 256 && skb->priority <= 263)
  		return skb->priority - 256;
  
  	switch (skb->protocol) {
  	case htons(ETH_P_IP):

  		dscp = ipv4_get_dsfield(ip_hdr(skb)) & 0xfc;
  		break;
  	case htons(ETH_P_IPV6):
  		dscp = ipv6_get_dsfield(ipv6_hdr(skb)) & 0xfc;

  		break;
  	default:
  		return 0;
  	}
  
  	return dscp >> 5;
  }
  EXPORT_SYMBOL(cfg80211_classify8021d);

  
  const u8 *ieee80211_bss_get_ie(struct cfg80211_bss *bss, u8 ie)
  {
  	u8 *end, *pos;
  
  	pos = bss->information_elements;
  	if (pos == NULL)
  		return NULL;
  	end = pos + bss->len_information_elements;
  
  	while (pos + 1 < end) {
  		if (pos + 2 + pos[1] > end)
  			break;
  		if (pos[0] == ie)
  			return pos;
  		pos += 2 + pos[1];
  	}
  
  	return NULL;
  }
  EXPORT_SYMBOL(ieee80211_bss_get_ie);

  
  void cfg80211_upload_connect_keys(struct wireless_dev *wdev)
  {
  	struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
  	struct net_device *dev = wdev->netdev;
  	int i;
  
  	if (!wdev->connect_keys)
  		return;
  
  	for (i = 0; i < 6; i++) {
  		if (!wdev->connect_keys->params[i].cipher)
  			continue;

  		if (rdev->ops->add_key(wdev->wiphy, dev, i, false, NULL,

  					&wdev->connect_keys->params[i])) {

  			netdev_err(dev, "failed to set key %d
  ", i);

  			continue;
  		}

  		if (wdev->connect_keys->def == i)

  			if (rdev->ops->set_default_key(wdev->wiphy, dev,
  						       i, true, true)) {

  				netdev_err(dev, "failed to set defkey %d
  ", i);

  				continue;
  			}

  		if (wdev->connect_keys->defmgmt == i)
  			if (rdev->ops->set_default_mgmt_key(wdev->wiphy, dev, i))

  				netdev_err(dev, "failed to set mgtdef %d
  ", i);

  	}
  
  	kfree(wdev->connect_keys);
  	wdev->connect_keys = NULL;
  }

  
  static void cfg80211_process_wdev_events(struct wireless_dev *wdev)
  {
  	struct cfg80211_event *ev;
  	unsigned long flags;
  	const u8 *bssid = NULL;
  
  	spin_lock_irqsave(&wdev->event_lock, flags);
  	while (!list_empty(&wdev->event_list)) {
  		ev = list_first_entry(&wdev->event_list,
  				      struct cfg80211_event, list);
  		list_del(&ev->list);
  		spin_unlock_irqrestore(&wdev->event_lock, flags);
  
  		wdev_lock(wdev);
  		switch (ev->type) {
  		case EVENT_CONNECT_RESULT:
  			if (!is_zero_ether_addr(ev->cr.bssid))
  				bssid = ev->cr.bssid;
  			__cfg80211_connect_result(
  				wdev->netdev, bssid,
  				ev->cr.req_ie, ev->cr.req_ie_len,
  				ev->cr.resp_ie, ev->cr.resp_ie_len,
  				ev->cr.status,
  				ev->cr.status == WLAN_STATUS_SUCCESS,
  				NULL);
  			break;
  		case EVENT_ROAMED:

  			__cfg80211_roamed(wdev, ev->rm.bss, ev->rm.req_ie,
  					  ev->rm.req_ie_len, ev->rm.resp_ie,
  					  ev->rm.resp_ie_len);

  			break;
  		case EVENT_DISCONNECTED:
  			__cfg80211_disconnected(wdev->netdev,
  						ev->dc.ie, ev->dc.ie_len,
  						ev->dc.reason, true);
  			break;
  		case EVENT_IBSS_JOINED:
  			__cfg80211_ibss_joined(wdev->netdev, ev->ij.bssid);
  			break;
  		}
  		wdev_unlock(wdev);
  
  		kfree(ev);
  
  		spin_lock_irqsave(&wdev->event_lock, flags);
  	}
  	spin_unlock_irqrestore(&wdev->event_lock, flags);
  }
  
  void cfg80211_process_rdev_events(struct cfg80211_registered_device *rdev)
  {
  	struct wireless_dev *wdev;
  
  	ASSERT_RTNL();
  	ASSERT_RDEV_LOCK(rdev);
  
  	mutex_lock(&rdev->devlist_mtx);
  
  	list_for_each_entry(wdev, &rdev->netdev_list, list)
  		cfg80211_process_wdev_events(wdev);
  
  	mutex_unlock(&rdev->devlist_mtx);
  }
  
  int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
  			  struct net_device *dev, enum nl80211_iftype ntype,
  			  u32 *flags, struct vif_params *params)
  {
  	int err;
  	enum nl80211_iftype otype = dev->ieee80211_ptr->iftype;
  
  	ASSERT_RDEV_LOCK(rdev);
  
  	/* don't support changing VLANs, you just re-create them */
  	if (otype == NL80211_IFTYPE_AP_VLAN)
  		return -EOPNOTSUPP;
  
  	if (!rdev->ops->change_virtual_intf ||
  	    !(rdev->wiphy.interface_modes & (1 << ntype)))
  		return -EOPNOTSUPP;

  	/* if it's part of a bridge, reject changing type to station/ibss */

  	if ((dev->priv_flags & IFF_BRIDGE_PORT) &&

  	    (ntype == NL80211_IFTYPE_ADHOC ||
  	     ntype == NL80211_IFTYPE_STATION ||
  	     ntype == NL80211_IFTYPE_P2P_CLIENT))

  		return -EBUSY;

  	if (ntype != otype) {

  		err = cfg80211_can_change_interface(rdev, dev->ieee80211_ptr,
  						    ntype);
  		if (err)
  			return err;

  		dev->ieee80211_ptr->use_4addr = false;

  		dev->ieee80211_ptr->mesh_id_up_len = 0;

  		switch (otype) {
  		case NL80211_IFTYPE_ADHOC:
  			cfg80211_leave_ibss(rdev, dev, false);
  			break;
  		case NL80211_IFTYPE_STATION:

  		case NL80211_IFTYPE_P2P_CLIENT:

  			cfg80211_disconnect(rdev, dev,
  					    WLAN_REASON_DEAUTH_LEAVING, true);
  			break;
  		case NL80211_IFTYPE_MESH_POINT:
  			/* mesh should be handled? */
  			break;
  		default:
  			break;
  		}
  
  		cfg80211_process_rdev_events(rdev);
  	}
  
  	err = rdev->ops->change_virtual_intf(&rdev->wiphy, dev,
  					     ntype, flags, params);
  
  	WARN_ON(!err && dev->ieee80211_ptr->iftype != ntype);

  	if (!err && params && params->use_4addr != -1)
  		dev->ieee80211_ptr->use_4addr = params->use_4addr;

  	if (!err) {
  		dev->priv_flags &= ~IFF_DONT_BRIDGE;
  		switch (ntype) {
  		case NL80211_IFTYPE_STATION:
  			if (dev->ieee80211_ptr->use_4addr)
  				break;
  			/* fall through */

  		case NL80211_IFTYPE_P2P_CLIENT:

  		case NL80211_IFTYPE_ADHOC:
  			dev->priv_flags |= IFF_DONT_BRIDGE;
  			break;

  		case NL80211_IFTYPE_P2P_GO:

  		case NL80211_IFTYPE_AP:
  		case NL80211_IFTYPE_AP_VLAN:
  		case NL80211_IFTYPE_WDS:
  		case NL80211_IFTYPE_MESH_POINT:
  			/* bridging OK */
  			break;
  		case NL80211_IFTYPE_MONITOR:
  			/* monitor can't bridge anyway */
  			break;
  		case NL80211_IFTYPE_UNSPECIFIED:

  		case NUM_NL80211_IFTYPES:

  			/* not happening */
  			break;
  		}
  	}

  	return err;
  }

  
  u16 cfg80211_calculate_bitrate(struct rate_info *rate)
  {
  	int modulation, streams, bitrate;
  
  	if (!(rate->flags & RATE_INFO_FLAGS_MCS))
  		return rate->legacy;
  
  	/* the formula below does only work for MCS values smaller than 32 */
  	if (rate->mcs >= 32)
  		return 0;
  
  	modulation = rate->mcs & 7;
  	streams = (rate->mcs >> 3) + 1;
  
  	bitrate = (rate->flags & RATE_INFO_FLAGS_40_MHZ_WIDTH) ?
  			13500000 : 6500000;
  
  	if (modulation < 4)
  		bitrate *= (modulation + 1);
  	else if (modulation == 4)
  		bitrate *= (modulation + 2);
  	else
  		bitrate *= (modulation + 3);
  
  	bitrate *= streams;
  
  	if (rate->flags & RATE_INFO_FLAGS_SHORT_GI)
  		bitrate = (bitrate / 9) * 10;
  
  	/* do NOT round down here */
  	return (bitrate + 50000) / 100000;
  }

  
  int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
  				 u32 beacon_int)
  {
  	struct wireless_dev *wdev;
  	int res = 0;
  
  	if (!beacon_int)
  		return -EINVAL;
  
  	mutex_lock(&rdev->devlist_mtx);
  
  	list_for_each_entry(wdev, &rdev->netdev_list, list) {
  		if (!wdev->beacon_interval)
  			continue;
  		if (wdev->beacon_interval != beacon_int) {
  			res = -EINVAL;
  			break;
  		}
  	}
  
  	mutex_unlock(&rdev->devlist_mtx);
  
  	return res;
  }

  
  int cfg80211_can_change_interface(struct cfg80211_registered_device *rdev,
  				  struct wireless_dev *wdev,
  				  enum nl80211_iftype iftype)
  {
  	struct wireless_dev *wdev_iter;
  	int num[NUM_NL80211_IFTYPES];
  	int total = 1;
  	int i, j;
  
  	ASSERT_RTNL();
  
  	/* Always allow software iftypes */
  	if (rdev->wiphy.software_iftypes & BIT(iftype))
  		return 0;
  
  	/*
  	 * Drivers will gradually all set this flag, until all
  	 * have it we only enforce for those that set it.
  	 */
  	if (!(rdev->wiphy.flags & WIPHY_FLAG_ENFORCE_COMBINATIONS))
  		return 0;
  
  	memset(num, 0, sizeof(num));
  
  	num[iftype] = 1;
  
  	mutex_lock(&rdev->devlist_mtx);
  	list_for_each_entry(wdev_iter, &rdev->netdev_list, list) {
  		if (wdev_iter == wdev)
  			continue;
  		if (!netif_running(wdev_iter->netdev))
  			continue;
  
  		if (rdev->wiphy.software_iftypes & BIT(wdev_iter->iftype))
  			continue;
  
  		num[wdev_iter->iftype]++;
  		total++;
  	}
  	mutex_unlock(&rdev->devlist_mtx);
  
  	for (i = 0; i < rdev->wiphy.n_iface_combinations; i++) {
  		const struct ieee80211_iface_combination *c;
  		struct ieee80211_iface_limit *limits;
  
  		c = &rdev->wiphy.iface_combinations[i];
  
  		limits = kmemdup(c->limits, sizeof(limits[0]) * c->n_limits,
  				 GFP_KERNEL);
  		if (!limits)
  			return -ENOMEM;
  		if (total > c->max_interfaces)
  			goto cont;
  
  		for (iftype = 0; iftype < NUM_NL80211_IFTYPES; iftype++) {
  			if (rdev->wiphy.software_iftypes & BIT(iftype))
  				continue;
  			for (j = 0; j < c->n_limits; j++) {
  				if (!(limits[j].types & iftype))
  					continue;
  				if (limits[j].max < num[iftype])
  					goto cont;
  				limits[j].max -= num[iftype];
  			}
  		}
  		/* yay, it fits */
  		kfree(limits);
  		return 0;
   cont:
  		kfree(limits);
  	}
  
  	return -EBUSY;
  }

  
  int ieee80211_get_ratemask(struct ieee80211_supported_band *sband,
  			   const u8 *rates, unsigned int n_rates,
  			   u32 *mask)
  {
  	int i, j;

  	if (!sband)
  		return -EINVAL;

  	if (n_rates == 0 || n_rates > NL80211_MAX_SUPP_RATES)
  		return -EINVAL;
  
  	*mask = 0;
  
  	for (i = 0; i < n_rates; i++) {
  		int rate = (rates[i] & 0x7f) * 5;
  		bool found = false;
  
  		for (j = 0; j < sband->n_bitrates; j++) {
  			if (sband->bitrates[j].bitrate == rate) {
  				found = true;
  				*mask |= BIT(j);
  				break;
  			}
  		}
  		if (!found)
  			return -EINVAL;
  	}
  
  	/*
  	 * mask must have at least one bit set here since we
  	 * didn't accept a 0-length rates array nor allowed
  	 * entries in the array that didn't exist
  	 */
  
  	return 0;
  }

  
  /* 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 };
  EXPORT_SYMBOL(rfc1042_header);
  
  /* 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 };
  EXPORT_SYMBOL(bridge_tunnel_header);