// SPDX-License-Identifier: GPL-2.0

  /*
   * Wireless utility functions
   *

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

   * Copyright 2013-2014  Intel Mobile Communications GmbH

   */

  #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 <linux/if_vlan.h>

  #include <linux/mpls.h>

  #include <linux/gcd.h>

  #include "core.h"

  #include "rdev-ops.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);

  u32 ieee80211_mandatory_rates(struct ieee80211_supported_band *sband,
  			      enum nl80211_bss_scan_width scan_width)

  {
  	struct ieee80211_rate *bitrates;
  	u32 mandatory_rates = 0;
  	enum ieee80211_rate_flags mandatory_flag;
  	int i;
  
  	if (WARN_ON(!sband))
  		return 1;

  	if (sband->band == NL80211_BAND_2GHZ) {

  		if (scan_width == NL80211_BSS_CHAN_WIDTH_5 ||
  		    scan_width == NL80211_BSS_CHAN_WIDTH_10)
  			mandatory_flag = IEEE80211_RATE_MANDATORY_G;
  		else
  			mandatory_flag = IEEE80211_RATE_MANDATORY_B;
  	} else {

  		mandatory_flag = IEEE80211_RATE_MANDATORY_A;

  	}

  
  	bitrates = sband->bitrates;
  	for (i = 0; i < sband->n_bitrates; i++)
  		if (bitrates[i].flags & mandatory_flag)
  			mandatory_rates |= BIT(i);
  	return mandatory_rates;
  }
  EXPORT_SYMBOL(ieee80211_mandatory_rates);

  int ieee80211_channel_to_frequency(int chan, enum nl80211_band band)

  {

  	/* see 802.11 17.3.8.3.2 and Annex J
  	 * there are overlapping channel numbers in 5GHz and 2GHz bands */

  	if (chan <= 0)
  		return 0; /* not supported */
  	switch (band) {

  	case NL80211_BAND_2GHZ:

  		if (chan == 14)
  			return 2484;
  		else if (chan < 14)
  			return 2407 + chan * 5;

  		break;

  	case NL80211_BAND_5GHZ:

  		if (chan >= 182 && chan <= 196)
  			return 4000 + chan * 5;

  		else

  			return 5000 + chan * 5;
  		break;

  	case NL80211_BAND_60GHZ:

  		if (chan < 5)
  			return 56160 + chan * 2160;
  		break;
  	default:
  		;

  	}

  	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 if (freq <= 45000) /* DMG band lower limit */

  		return (freq - 5000) / 5;

  	else if (freq >= 58320 && freq <= 64800)
  		return (freq - 56160) / 2160;
  	else
  		return 0;

  }
  EXPORT_SYMBOL(ieee80211_frequency_to_channel);

  struct ieee80211_channel *ieee80211_get_channel(struct wiphy *wiphy, int freq)

  {

  	enum nl80211_band band;

  	struct ieee80211_supported_band *sband;
  	int i;

  	for (band = 0; band < NUM_NL80211_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)

  {
  	int i, want;

  	switch (sband->band) {

  	case NL80211_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 NL80211_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 NL80211_BAND_60GHZ:

  		/* check for mandatory HT MCS 1..4 */
  		WARN_ON(!sband->ht_cap.ht_supported);
  		WARN_ON((sband->ht_cap.mcs.rx_mask[0] & 0x1e) != 0x1e);
  		break;

  	case NUM_NL80211_BANDS:

  	default:

  		WARN_ON(1);
  		break;
  	}
  }
  
  void ieee80211_set_bitrate_flags(struct wiphy *wiphy)
  {

  	enum nl80211_band band;

  	for (band = 0; band < NUM_NL80211_BANDS; band++)

  		if (wiphy->bands[band])

  			set_mandatory_flags_band(wiphy->bands[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 < 0 || key_idx > 5)

  		return -EINVAL;

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

  	switch (params->cipher) {
  	case WLAN_CIPHER_SUITE_TKIP:
  	case WLAN_CIPHER_SUITE_CCMP:

  	case WLAN_CIPHER_SUITE_CCMP_256:
  	case WLAN_CIPHER_SUITE_GCMP:
  	case WLAN_CIPHER_SUITE_GCMP_256:

  		/* 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)
  			return -EINVAL;
  		break;
  	case WLAN_CIPHER_SUITE_AES_CMAC:

  	case WLAN_CIPHER_SUITE_BIP_CMAC_256:
  	case WLAN_CIPHER_SUITE_BIP_GMAC_128:
  	case WLAN_CIPHER_SUITE_BIP_GMAC_256:

  		/* Disallow BIP (group-only) cipher as pairwise cipher */
  		if (pairwise)
  			return -EINVAL;

  		if (key_idx < 4)
  			return -EINVAL;

  		break;

  	case WLAN_CIPHER_SUITE_WEP40:
  	case WLAN_CIPHER_SUITE_WEP104:
  		if (key_idx > 3)
  			return -EINVAL;

  	default:
  		break;
  	}

  	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_CCMP_256:
  		if (params->key_len != WLAN_KEY_LEN_CCMP_256)
  			return -EINVAL;
  		break;
  	case WLAN_CIPHER_SUITE_GCMP:
  		if (params->key_len != WLAN_KEY_LEN_GCMP)
  			return -EINVAL;
  		break;
  	case WLAN_CIPHER_SUITE_GCMP_256:
  		if (params->key_len != WLAN_KEY_LEN_GCMP_256)
  			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;

  	case WLAN_CIPHER_SUITE_BIP_CMAC_256:
  		if (params->key_len != WLAN_KEY_LEN_BIP_CMAC_256)
  			return -EINVAL;
  		break;
  	case WLAN_CIPHER_SUITE_BIP_GMAC_128:
  		if (params->key_len != WLAN_KEY_LEN_BIP_GMAC_128)
  			return -EINVAL;
  		break;
  	case WLAN_CIPHER_SUITE_BIP_GMAC_256:
  		if (params->key_len != WLAN_KEY_LEN_BIP_GMAC_256)
  			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_CCMP_256:
  		case WLAN_CIPHER_SUITE_GCMP:
  		case WLAN_CIPHER_SUITE_GCMP_256:

  		case WLAN_CIPHER_SUITE_AES_CMAC:

  		case WLAN_CIPHER_SUITE_BIP_CMAC_256:
  		case WLAN_CIPHER_SUITE_BIP_GMAC_128:
  		case WLAN_CIPHER_SUITE_BIP_GMAC_256:

  			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_mgmt(fc)) {
  		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 unsigned int __ieee80211_get_mesh_hdrlen(u8 flags)

  {

  	int ae = flags & MESH_FLAGS_AE;

  	/* 802.11-2012, 8.2.4.7.3 */

  	switch (ae) {

  	default:

  	case 0:
  		return 6;

  	case MESH_FLAGS_AE_A4:

  		return 12;

  	case MESH_FLAGS_AE_A5_A6:

  		return 18;

  	}
  }

  
  unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
  {
  	return __ieee80211_get_mesh_hdrlen(meshhdr->flags);
  }

  EXPORT_SYMBOL(ieee80211_get_mesh_hdrlen);

  int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
  				  const u8 *addr, enum nl80211_iftype iftype)

  {
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;

  	struct {
  		u8 hdr[ETH_ALEN] __aligned(2);
  		__be16 proto;
  	} payload;
  	struct ethhdr tmp;
  	u16 hdrlen;
  	u8 mesh_flags = 0;

  
  	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
  		return -1;
  
  	hdrlen = ieee80211_hdrlen(hdr->frame_control);

  	if (skb->len < hdrlen + 8)
  		return -1;

  
  	/* 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(tmp.h_dest, ieee80211_get_DA(hdr), ETH_ALEN);
  	memcpy(tmp.h_source, ieee80211_get_SA(hdr), ETH_ALEN);
  
  	if (iftype == NL80211_IFTYPE_MESH_POINT)
  		skb_copy_bits(skb, hdrlen, &mesh_flags, 1);

  	mesh_flags &= MESH_FLAGS_AE;

  	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) {

  			if (mesh_flags == MESH_FLAGS_AE_A4)

  				return -1;

  			if (mesh_flags == MESH_FLAGS_AE_A5_A6) {

  				skb_copy_bits(skb, hdrlen +
  					offsetof(struct ieee80211s_hdr, eaddr1),

  					tmp.h_dest, 2 * ETH_ALEN);

  			}

  			hdrlen += __ieee80211_get_mesh_hdrlen(mesh_flags);

  		}
  		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(tmp.h_dest) &&
  		     ether_addr_equal(tmp.h_source, addr)))

  			return -1;

  		if (iftype == NL80211_IFTYPE_MESH_POINT) {

  			if (mesh_flags == MESH_FLAGS_AE_A5_A6)

  				return -1;

  			if (mesh_flags == MESH_FLAGS_AE_A4)

  				skb_copy_bits(skb, hdrlen +
  					offsetof(struct ieee80211s_hdr, eaddr1),

  					tmp.h_source, ETH_ALEN);
  			hdrlen += __ieee80211_get_mesh_hdrlen(mesh_flags);

  		}

  		break;
  	case cpu_to_le16(0):

  		if (iftype != NL80211_IFTYPE_ADHOC &&

  		    iftype != NL80211_IFTYPE_STATION &&
  		    iftype != NL80211_IFTYPE_OCB)

  				return -1;

  		break;
  	}

  	skb_copy_bits(skb, hdrlen, &payload, sizeof(payload));
  	tmp.h_proto = payload.proto;

  	if (likely((ether_addr_equal(payload.hdr, rfc1042_header) &&
  		    tmp.h_proto != htons(ETH_P_AARP) &&
  		    tmp.h_proto != htons(ETH_P_IPX)) ||
  		   ether_addr_equal(payload.hdr, bridge_tunnel_header)))

  		/* remove RFC1042 or Bridge-Tunnel encapsulation and
  		 * replace EtherType */

  		hdrlen += ETH_ALEN + 2;
  	else

  		tmp.h_proto = htons(skb->len - hdrlen);

  
  	pskb_pull(skb, hdrlen);

  	if (!ehdr)

  		ehdr = skb_push(skb, sizeof(struct ethhdr));

  	memcpy(ehdr, &tmp, sizeof(tmp));

  	return 0;
  }

  EXPORT_SYMBOL(ieee80211_data_to_8023_exthdr);

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

  			     enum nl80211_iftype iftype,
  			     const 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_OCB:

  	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 >= ETH_P_802_3_MIN) {

  		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;

  	}
  
  	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_reset_mac_header(skb);

  	skb_set_network_header(skb, nh_pos);
  	skb_set_transport_header(skb, h_pos);
  
  	return 0;
  }
  EXPORT_SYMBOL(ieee80211_data_from_8023);

  static void
  __frame_add_frag(struct sk_buff *skb, struct page *page,
  		 void *ptr, int len, int size)
  {
  	struct skb_shared_info *sh = skb_shinfo(skb);
  	int page_offset;

  	page_ref_inc(page);

  	page_offset = ptr - page_address(page);
  	skb_add_rx_frag(skb, sh->nr_frags, page, page_offset, len, size);
  }
  
  static void
  __ieee80211_amsdu_copy_frag(struct sk_buff *skb, struct sk_buff *frame,
  			    int offset, int len)
  {
  	struct skb_shared_info *sh = skb_shinfo(skb);

  	const skb_frag_t *frag = &sh->frags[0];

  	struct page *frag_page;
  	void *frag_ptr;
  	int frag_len, frag_size;
  	int head_size = skb->len - skb->data_len;
  	int cur_len;
  
  	frag_page = virt_to_head_page(skb->head);
  	frag_ptr = skb->data;
  	frag_size = head_size;
  
  	while (offset >= frag_size) {
  		offset -= frag_size;

  		frag_page = skb_frag_page(frag);
  		frag_ptr = skb_frag_address(frag);
  		frag_size = skb_frag_size(frag);

  		frag++;

  	}
  
  	frag_ptr += offset;
  	frag_len = frag_size - offset;
  
  	cur_len = min(len, frag_len);
  
  	__frame_add_frag(frame, frag_page, frag_ptr, cur_len, frag_size);
  	len -= cur_len;
  
  	while (len > 0) {

  		frag_len = skb_frag_size(frag);
  		cur_len = min(len, frag_len);
  		__frame_add_frag(frame, skb_frag_page(frag),
  				 skb_frag_address(frag), cur_len, frag_len);
  		len -= cur_len;

  		frag++;

  	}
  }

  static struct sk_buff *
  __ieee80211_amsdu_copy(struct sk_buff *skb, unsigned int hlen,

  		       int offset, int len, bool reuse_frag)

  {
  	struct sk_buff *frame;

  	int cur_len = len;

  
  	if (skb->len - offset < len)
  		return NULL;
  
  	/*

  	 * When reusing framents, copy some data to the head to simplify
  	 * ethernet header handling and speed up protocol header processing
  	 * in the stack later.
  	 */
  	if (reuse_frag)
  		cur_len = min_t(int, len, 32);
  
  	/*

  	 * Allocate and reserve two bytes more for payload
  	 * alignment since sizeof(struct ethhdr) is 14.
  	 */

  	frame = dev_alloc_skb(hlen + sizeof(struct ethhdr) + 2 + cur_len);

  	if (!frame)
  		return NULL;

  
  	skb_reserve(frame, hlen + sizeof(struct ethhdr) + 2);

  	skb_copy_bits(skb, offset, skb_put(frame, cur_len), cur_len);
  
  	len -= cur_len;
  	if (!len)
  		return frame;
  
  	offset += cur_len;
  	__ieee80211_amsdu_copy_frag(skb, frame, offset, len);

  
  	return frame;
  }

  
  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,

  			      const u8 *check_da, const u8 *check_sa)

  {

  	unsigned int hlen = ALIGN(extra_headroom, 4);

  	struct sk_buff *frame = NULL;
  	u16 ethertype;
  	u8 *payload;

  	int offset = 0, remaining;

  	struct ethhdr eth;

  	bool reuse_frag = skb->head_frag && !skb_has_frag_list(skb);

  	bool reuse_skb = false;

  	bool last = false;

  	while (!last) {
  		unsigned int subframe_len;
  		int len;

  		u8 padding;

  		skb_copy_bits(skb, offset, &eth, sizeof(eth));
  		len = ntohs(eth.h_proto);
  		subframe_len = sizeof(struct ethhdr) + len;

  		padding = (4 - subframe_len) & 0x3;

  		/* the last MSDU has no padding */

  		remaining = skb->len - offset;

  		if (subframe_len > remaining)
  			goto purge;

  		offset += sizeof(struct ethhdr);

  		last = remaining <= subframe_len + padding;

  
  		/* FIXME: should we really accept multicast DA? */
  		if ((check_da && !is_multicast_ether_addr(eth.h_dest) &&
  		     !ether_addr_equal(check_da, eth.h_dest)) ||
  		    (check_sa && !ether_addr_equal(check_sa, eth.h_source))) {
  			offset += len + padding;
  			continue;
  		}
  
  		/* reuse skb for the last subframe */

  		if (!skb_is_nonlinear(skb) && !reuse_frag && last) {

  			skb_pull(skb, offset);

  			frame = skb;

  			reuse_skb = true;
  		} else {

  			frame = __ieee80211_amsdu_copy(skb, hlen, offset, len,
  						       reuse_frag);

  			if (!frame)
  				goto purge;

  			offset += len + padding;

  		}
  
  		skb_reset_network_header(frame);
  		frame->dev = skb->dev;
  		frame->priority = skb->priority;
  
  		payload = frame->data;
  		ethertype = (payload[6] << 8) | payload[7];

  		if (likely((ether_addr_equal(payload, rfc1042_header) &&

  			    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||

  			   ether_addr_equal(payload, bridge_tunnel_header))) {

  			eth.h_proto = htons(ethertype);
  			skb_pull(frame, ETH_ALEN + 2);

  		}

  
  		memcpy(skb_push(frame, sizeof(eth)), &eth, sizeof(eth));

  		__skb_queue_tail(list, frame);
  	}

  	if (!reuse_skb)
  		dev_kfree_skb(skb);

  	return;
  
   purge:
  	__skb_queue_purge(list);

  	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,
  				    struct cfg80211_qos_map *qos_map)

  {
  	unsigned int dscp;

  	unsigned char vlan_priority;

  
  	/* 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;

  	if (skb_vlan_tag_present(skb)) {
  		vlan_priority = (skb_vlan_tag_get(skb) & VLAN_PRIO_MASK)

  			>> VLAN_PRIO_SHIFT;
  		if (vlan_priority > 0)
  			return vlan_priority;
  	}

  	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;

  	case htons(ETH_P_MPLS_UC):
  	case htons(ETH_P_MPLS_MC): {
  		struct mpls_label mpls_tmp, *mpls;
  
  		mpls = skb_header_pointer(skb, sizeof(struct ethhdr),
  					  sizeof(*mpls), &mpls_tmp);
  		if (!mpls)
  			return 0;
  
  		return (ntohl(mpls->entry) & MPLS_LS_TC_MASK)
  			>> MPLS_LS_TC_SHIFT;
  	}
  	case htons(ETH_P_80221):
  		/* 802.21 is always network control traffic */
  		return 7;

  	default:
  		return 0;
  	}

  	if (qos_map) {
  		unsigned int i, tmp_dscp = dscp >> 2;
  
  		for (i = 0; i < qos_map->num_des; i++) {
  			if (tmp_dscp == qos_map->dscp_exception[i].dscp)
  				return qos_map->dscp_exception[i].up;
  		}
  
  		for (i = 0; i < 8; i++) {
  			if (tmp_dscp >= qos_map->up[i].low &&
  			    tmp_dscp <= qos_map->up[i].high)
  				return i;
  		}
  	}

  	return dscp >> 5;
  }
  EXPORT_SYMBOL(cfg80211_classify8021d);

  
  const u8 *ieee80211_bss_get_ie(struct cfg80211_bss *bss, u8 ie)
  {

  	const struct cfg80211_bss_ies *ies;
  
  	ies = rcu_dereference(bss->ies);
  	if (!ies)

  		return NULL;

  
  	return cfg80211_find_ie(ie, ies->data, ies->len);

  }
  EXPORT_SYMBOL(ieee80211_bss_get_ie);

  
  void cfg80211_upload_connect_keys(struct wireless_dev *wdev)
  {

  	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);

  	struct net_device *dev = wdev->netdev;
  	int i;
  
  	if (!wdev->connect_keys)
  		return;

  	for (i = 0; i < CFG80211_MAX_WEP_KEYS; i++) {

  		if (!wdev->connect_keys->params[i].cipher)
  			continue;

  		if (rdev_add_key(rdev, 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 &&
  		    rdev_set_default_key(rdev, dev, i, true, true)) {
  			netdev_err(dev, "failed to set defkey %d
  ", i);
  			continue;
  		}

  	}

  	kzfree(wdev->connect_keys);

  	wdev->connect_keys = NULL;
  }

  void cfg80211_process_wdev_events(struct wireless_dev *wdev)

  {
  	struct cfg80211_event *ev;
  	unsigned long flags;

  
  	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:

  			__cfg80211_connect_result(

  				wdev->netdev,
  				&ev->cr,
  				ev->cr.status == WLAN_STATUS_SUCCESS);

  			break;
  		case EVENT_ROAMED:

  			__cfg80211_roamed(wdev, &ev->rm);

  			break;
  		case EVENT_DISCONNECTED:
  			__cfg80211_disconnected(wdev->netdev,
  						ev->dc.ie, ev->dc.ie_len,

  						ev->dc.reason,
  						!ev->dc.locally_generated);

  			break;
  		case EVENT_IBSS_JOINED:

  			__cfg80211_ibss_joined(wdev->netdev, ev->ij.bssid,
  					       ev->ij.channel);

  			break;

  		case EVENT_STOPPED:
  			__cfg80211_leave(wiphy_to_rdev(wdev->wiphy), wdev);
  			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();

  	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list)

  		cfg80211_process_wdev_events(wdev);

  }
  
  int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
  			  struct net_device *dev, enum nl80211_iftype ntype,

  			  struct vif_params *params)

  {
  	int err;
  	enum nl80211_iftype otype = dev->ieee80211_ptr->iftype;

  	ASSERT_RTNL();

  
  	/* don't support changing VLANs, you just re-create them */
  	if (otype == NL80211_IFTYPE_AP_VLAN)
  		return -EOPNOTSUPP;

  	/* cannot change into P2P device or NAN */
  	if (ntype == NL80211_IFTYPE_P2P_DEVICE ||
  	    ntype == NL80211_IFTYPE_NAN)

  		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) {

  		dev->ieee80211_ptr->use_4addr = false;

  		dev->ieee80211_ptr->mesh_id_up_len = 0;

  		wdev_lock(dev->ieee80211_ptr);

  		rdev_set_qos_map(rdev, dev, NULL);

  		wdev_unlock(dev->ieee80211_ptr);

  		switch (otype) {

  		case NL80211_IFTYPE_AP:

  			cfg80211_stop_ap(rdev, dev, true);

  			break;

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

  		case NL80211_IFTYPE_P2P_CLIENT:

  			wdev_lock(dev->ieee80211_ptr);

  			cfg80211_disconnect(rdev, dev,
  					    WLAN_REASON_DEAUTH_LEAVING, true);

  			wdev_unlock(dev->ieee80211_ptr);

  			break;
  		case NL80211_IFTYPE_MESH_POINT:
  			/* mesh should be handled? */
  			break;
  		default:
  			break;
  		}
  
  		cfg80211_process_rdev_events(rdev);
  	}

  	err = rdev_change_virtual_intf(rdev, dev, ntype, 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_OCB:

  		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;

  		case NL80211_IFTYPE_P2P_DEVICE:

  		case NL80211_IFTYPE_NAN:

  			WARN_ON(1);
  			break;

  		}
  	}

  	if (!err && ntype != otype && netif_running(dev)) {
  		cfg80211_update_iface_num(rdev, ntype, 1);
  		cfg80211_update_iface_num(rdev, otype, -1);
  	}

  	return err;
  }

  static u32 cfg80211_calculate_bitrate_ht(struct rate_info *rate)
  {
  	int modulation, streams, bitrate;
  
  	/* the formula below does only work for MCS values smaller than 32 */
  	if (WARN_ON_ONCE(rate->mcs >= 32))
  		return 0;
  
  	modulation = rate->mcs & 7;
  	streams = (rate->mcs >> 3) + 1;
  
  	bitrate = (rate->bw == RATE_INFO_BW_40) ? 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;
  }

  static u32 cfg80211_calculate_bitrate_60g(struct rate_info *rate)
  {
  	static const u32 __mcs2bitrate[] = {
  		/* control PHY */
  		[0] =   275,
  		/* SC PHY */
  		[1] =  3850,
  		[2] =  7700,
  		[3] =  9625,
  		[4] = 11550,
  		[5] = 12512, /* 1251.25 mbps */
  		[6] = 15400,
  		[7] = 19250,
  		[8] = 23100,
  		[9] = 25025,
  		[10] = 30800,
  		[11] = 38500,
  		[12] = 46200,
  		/* OFDM PHY */
  		[13] =  6930,
  		[14] =  8662, /* 866.25 mbps */
  		[15] = 13860,
  		[16] = 17325,
  		[17] = 20790,
  		[18] = 27720,
  		[19] = 34650,
  		[20] = 41580,
  		[21] = 45045,
  		[22] = 51975,
  		[23] = 62370,
  		[24] = 67568, /* 6756.75 mbps */
  		/* LP-SC PHY */
  		[25] =  6260,
  		[26] =  8340,
  		[27] = 11120,
  		[28] = 12510,
  		[29] = 16680,
  		[30] = 22240,
  		[31] = 25030,
  	};
  
  	if (WARN_ON_ONCE(rate->mcs >= ARRAY_SIZE(__mcs2bitrate)))
  		return 0;
  
  	return __mcs2bitrate[rate->mcs];
  }

  static u32 cfg80211_calculate_bitrate_vht(struct rate_info *rate)
  {
  	static const u32 base[4][10] = {
  		{   6500000,
  		   13000000,
  		   19500000,
  		   26000000,
  		   39000000,
  		   52000000,
  		   58500000,
  		   65000000,
  		   78000000,

  		/* not in the spec, but some devices use this: */
  		   86500000,

  		},
  		{  13500000,
  		   27000000,
  		   40500000,
  		   54000000,
  		   81000000,
  		  108000000,
  		  121500000,
  		  135000000,
  		  162000000,
  		  180000000,
  		},
  		{  29300000,
  		   58500000,
  		   87800000,
  		  117000000,
  		  175500000,
  		  234000000,
  		  263300000,
  		  292500000,
  		  351000000,
  		  390000000,
  		},
  		{  58500000,
  		  117000000,
  		  175500000,
  		  234000000,
  		  351000000,
  		  468000000,
  		  526500000,
  		  585000000,
  		  702000000,
  		  780000000,
  		},
  	};
  	u32 bitrate;
  	int idx;

  	if (rate->mcs > 9)
  		goto warn;

  	switch (rate->bw) {
  	case RATE_INFO_BW_160:
  		idx = 3;
  		break;
  	case RATE_INFO_BW_80:
  		idx = 2;
  		break;
  	case RATE_INFO_BW_40:
  		idx = 1;
  		break;
  	case RATE_INFO_BW_5:
  	case RATE_INFO_BW_10:
  	default:

  		goto warn;

  	case RATE_INFO_BW_20:
  		idx = 0;
  	}

  
  	bitrate = base[idx][rate->mcs];
  	bitrate *= rate->nss;
  
  	if (rate->flags & RATE_INFO_FLAGS_SHORT_GI)
  		bitrate = (bitrate / 9) * 10;
  
  	/* do NOT round down here */
  	return (bitrate + 50000) / 100000;

   warn:
  	WARN_ONCE(1, "invalid rate bw=%d, mcs=%d, nss=%d
  ",
  		  rate->bw, rate->mcs, rate->nss);
  	return 0;

  }

  u32 cfg80211_calculate_bitrate(struct rate_info *rate)

  {

  	if (rate->flags & RATE_INFO_FLAGS_MCS)
  		return cfg80211_calculate_bitrate_ht(rate);

  	if (rate->flags & RATE_INFO_FLAGS_60G)
  		return cfg80211_calculate_bitrate_60g(rate);

  	if (rate->flags & RATE_INFO_FLAGS_VHT_MCS)
  		return cfg80211_calculate_bitrate_vht(rate);

  	return rate->legacy;

  }

  EXPORT_SYMBOL(cfg80211_calculate_bitrate);

  int cfg80211_get_p2p_attr(const u8 *ies, unsigned int len,
  			  enum ieee80211_p2p_attr_id attr,
  			  u8 *buf, unsigned int bufsize)

  {
  	u8 *out = buf;
  	u16 attr_remaining = 0;
  	bool desired_attr = false;
  	u16 desired_len = 0;
  
  	while (len > 0) {
  		unsigned int iedatalen;
  		unsigned int copy;
  		const u8 *iedata;
  
  		if (len < 2)
  			return -EILSEQ;
  		iedatalen = ies[1];
  		if (iedatalen + 2 > len)
  			return -EILSEQ;
  
  		if (ies[0] != WLAN_EID_VENDOR_SPECIFIC)
  			goto cont;
  
  		if (iedatalen < 4)
  			goto cont;
  
  		iedata = ies + 2;
  
  		/* check WFA OUI, P2P subtype */
  		if (iedata[0] != 0x50 || iedata[1] != 0x6f ||
  		    iedata[2] != 0x9a || iedata[3] != 0x09)
  			goto cont;
  
  		iedatalen -= 4;
  		iedata += 4;
  
  		/* check attribute continuation into this IE */
  		copy = min_t(unsigned int, attr_remaining, iedatalen);
  		if (copy && desired_attr) {
  			desired_len += copy;
  			if (out) {
  				memcpy(out, iedata, min(bufsize, copy));
  				out += min(bufsize, copy);
  				bufsize -= min(bufsize, copy);
  			}
  
  
  			if (copy == attr_remaining)
  				return desired_len;
  		}
  
  		attr_remaining -= copy;
  		if (attr_remaining)
  			goto cont;
  
  		iedatalen -= copy;
  		iedata += copy;
  
  		while (iedatalen > 0) {
  			u16 attr_len;
  
  			/* P2P attribute ID & size must fit */
  			if (iedatalen < 3)
  				return -EILSEQ;
  			desired_attr = iedata[0] == attr;
  			attr_len = get_unaligned_le16(iedata + 1);
  			iedatalen -= 3;
  			iedata += 3;
  
  			copy = min_t(unsigned int, attr_len, iedatalen);
  
  			if (desired_attr) {
  				desired_len += copy;
  				if (out) {
  					memcpy(out, iedata, min(bufsize, copy));
  					out += min(bufsize, copy);
  					bufsize -= min(bufsize, copy);
  				}
  
  				if (copy == attr_len)
  					return desired_len;
  			}
  
  			iedata += copy;
  			iedatalen -= copy;
  			attr_remaining = attr_len - copy;
  		}
  
   cont:
  		len -= ies[1] + 2;
  		ies += ies[1] + 2;
  	}
  
  	if (attr_remaining && desired_attr)
  		return -EILSEQ;
  
  	return -ENOENT;
  }
  EXPORT_SYMBOL(cfg80211_get_p2p_attr);

  static bool ieee80211_id_in_list(const u8 *ids, int n_ids, u8 id)
  {
  	int i;
  
  	for (i = 0; i < n_ids; i++)
  		if (ids[i] == id)
  			return true;
  	return false;
  }

  static size_t skip_ie(const u8 *ies, size_t ielen, size_t pos)
  {
  	/* we assume a validly formed IEs buffer */
  	u8 len = ies[pos + 1];
  
  	pos += 2 + len;
  
  	/* the IE itself must have 255 bytes for fragments to follow */
  	if (len < 255)
  		return pos;
  
  	while (pos < ielen && ies[pos] == WLAN_EID_FRAGMENT) {
  		len = ies[pos + 1];
  		pos += 2 + len;
  	}
  
  	return pos;
  }

  size_t ieee80211_ie_split_ric(const u8 *ies, size_t ielen,
  			      const u8 *ids, int n_ids,
  			      const u8 *after_ric, int n_after_ric,
  			      size_t offset)
  {
  	size_t pos = offset;
  
  	while (pos < ielen && ieee80211_id_in_list(ids, n_ids, ies[pos])) {
  		if (ies[pos] == WLAN_EID_RIC_DATA && n_after_ric) {

  			pos = skip_ie(ies, ielen, pos);

  
  			while (pos < ielen &&
  			       !ieee80211_id_in_list(after_ric, n_after_ric,
  						     ies[pos]))

  				pos = skip_ie(ies, ielen, pos);

  		} else {

  			pos = skip_ie(ies, ielen, pos);

  		}
  	}
  
  	return pos;
  }
  EXPORT_SYMBOL(ieee80211_ie_split_ric);

  bool ieee80211_operating_class_to_band(u8 operating_class,

  				       enum nl80211_band *band)

  {
  	switch (operating_class) {
  	case 112:
  	case 115 ... 127:

  	case 128 ... 130:

  		*band = NL80211_BAND_5GHZ;

  		return true;
  	case 81:
  	case 82:
  	case 83:
  	case 84:

  		*band = NL80211_BAND_2GHZ;

  		return true;

  	case 180:

  		*band = NL80211_BAND_60GHZ;

  		return true;

  	}
  
  	return false;
  }
  EXPORT_SYMBOL(ieee80211_operating_class_to_band);

  bool ieee80211_chandef_to_operating_class(struct cfg80211_chan_def *chandef,
  					  u8 *op_class)
  {
  	u8 vht_opclass;

  	u32 freq = chandef->center_freq1;

  
  	if (freq >= 2412 && freq <= 2472) {
  		if (chandef->width > NL80211_CHAN_WIDTH_40)
  			return false;
  
  		/* 2.407 GHz, channels 1..13 */
  		if (chandef->width == NL80211_CHAN_WIDTH_40) {
  			if (freq > chandef->chan->center_freq)
  				*op_class = 83; /* HT40+ */
  			else
  				*op_class = 84; /* HT40- */
  		} else {
  			*op_class = 81;
  		}
  
  		return true;
  	}
  
  	if (freq == 2484) {
  		if (chandef->width > NL80211_CHAN_WIDTH_40)
  			return false;
  
  		*op_class = 82; /* channel 14 */
  		return true;
  	}
  
  	switch (chandef->width) {
  	case NL80211_CHAN_WIDTH_80:
  		vht_opclass = 128;
  		break;
  	case NL80211_CHAN_WIDTH_160:
  		vht_opclass = 129;
  		break;
  	case NL80211_CHAN_WIDTH_80P80:
  		vht_opclass = 130;
  		break;
  	case NL80211_CHAN_WIDTH_10:
  	case NL80211_CHAN_WIDTH_5:
  		return false; /* unsupported for now */
  	default:
  		vht_opclass = 0;
  		break;
  	}
  
  	/* 5 GHz, channels 36..48 */
  	if (freq >= 5180 && freq <= 5240) {
  		if (vht_opclass) {
  			*op_class = vht_opclass;
  		} else if (chandef->width == NL80211_CHAN_WIDTH_40) {
  			if (freq > chandef->chan->center_freq)
  				*op_class = 116;
  			else
  				*op_class = 117;
  		} else {
  			*op_class = 115;
  		}
  
  		return true;
  	}
  
  	/* 5 GHz, channels 52..64 */
  	if (freq >= 5260 && freq <= 5320) {
  		if (vht_opclass) {
  			*op_class = vht_opclass;
  		} else if (chandef->width == NL80211_CHAN_WIDTH_40) {
  			if (freq > chandef->chan->center_freq)
  				*op_class = 119;
  			else
  				*op_class = 120;
  		} else {
  			*op_class = 118;
  		}
  
  		return true;
  	}
  
  	/* 5 GHz, channels 100..144 */
  	if (freq >= 5500 && freq <= 5720) {
  		if (vht_opclass) {
  			*op_class = vht_opclass;
  		} else if (chandef->width == NL80211_CHAN_WIDTH_40) {
  			if (freq > chandef->chan->center_freq)
  				*op_class = 122;
  			else
  				*op_class = 123;
  		} else {
  			*op_class = 121;
  		}
  
  		return true;
  	}
  
  	/* 5 GHz, channels 149..169 */
  	if (freq >= 5745 && freq <= 5845) {
  		if (vht_opclass) {
  			*op_class = vht_opclass;
  		} else if (chandef->width == NL80211_CHAN_WIDTH_40) {
  			if (freq > chandef->chan->center_freq)
  				*op_class = 126;
  			else
  				*op_class = 127;
  		} else if (freq <= 5805) {
  			*op_class = 124;
  		} else {
  			*op_class = 125;
  		}
  
  		return true;
  	}
  
  	/* 56.16 GHz, channel 1..4 */
  	if (freq >= 56160 + 2160 * 1 && freq <= 56160 + 2160 * 4) {
  		if (chandef->width >= NL80211_CHAN_WIDTH_40)
  			return false;
  
  		*op_class = 180;
  		return true;
  	}
  
  	/* not supported yet */
  	return false;
  }
  EXPORT_SYMBOL(ieee80211_chandef_to_operating_class);

  static void cfg80211_calculate_bi_data(struct wiphy *wiphy, u32 new_beacon_int,
  				       u32 *beacon_int_gcd,
  				       bool *beacon_int_different)

  {
  	struct wireless_dev *wdev;

  	*beacon_int_gcd = 0;
  	*beacon_int_different = false;

  	list_for_each_entry(wdev, &wiphy->wdev_list, list) {

  		if (!wdev->beacon_interval)
  			continue;

  		if (!*beacon_int_gcd) {
  			*beacon_int_gcd = wdev->beacon_interval;

  			continue;

  		}

  		if (wdev->beacon_interval == *beacon_int_gcd)

  			continue;

  		*beacon_int_different = true;
  		*beacon_int_gcd = gcd(*beacon_int_gcd, wdev->beacon_interval);
  	}

  	if (new_beacon_int && *beacon_int_gcd != new_beacon_int) {
  		if (*beacon_int_gcd)
  			*beacon_int_different = true;
  		*beacon_int_gcd = gcd(*beacon_int_gcd, new_beacon_int);

  	}

  }

  int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
  				 enum nl80211_iftype iftype, u32 beacon_int)
  {
  	/*
  	 * This is just a basic pre-condition check; if interface combinations
  	 * are possible the driver must already be checking those with a call
  	 * to cfg80211_check_combinations(), in which case we'll validate more
  	 * through the cfg80211_calculate_bi_data() call and code in
  	 * cfg80211_iter_combinations().
  	 */
  
  	if (beacon_int < 10 || beacon_int > 10000)
  		return -EINVAL;
  
  	return 0;

  }

  int cfg80211_iter_combinations(struct wiphy *wiphy,

  			       struct iface_combination_params *params,

  			       void (*iter)(const struct ieee80211_iface_combination *c,
  					    void *data),
  			       void *data)

  {

  	const struct ieee80211_regdomain *regdom;
  	enum nl80211_dfs_regions region = 0;

  	int i, j, iftype;
  	int num_interfaces = 0;
  	u32 used_iftypes = 0;

  	u32 beacon_int_gcd;
  	bool beacon_int_different;
  
  	/*
  	 * This is a bit strange, since the iteration used to rely only on
  	 * the data given by the driver, but here it now relies on context,
  	 * in form of the currently operating interfaces.
  	 * This is OK for all current users, and saves us from having to
  	 * push the GCD calculations into all the drivers.
  	 * In the future, this should probably rely more on data that's in
  	 * cfg80211 already - the only thing not would appear to be any new
  	 * interfaces (while being brought up) and channel/radar data.
  	 */
  	cfg80211_calculate_bi_data(wiphy, params->new_beacon_int,
  				   &beacon_int_gcd, &beacon_int_different);

  	if (params->radar_detect) {

  		rcu_read_lock();
  		regdom = rcu_dereference(cfg80211_regdomain);
  		if (regdom)
  			region = regdom->dfs_region;
  		rcu_read_unlock();
  	}

  	for (iftype = 0; iftype < NUM_NL80211_IFTYPES; iftype++) {

  		num_interfaces += params->iftype_num[iftype];
  		if (params->iftype_num[iftype] > 0 &&

  		    !(wiphy->software_iftypes & BIT(iftype)))
  			used_iftypes |= BIT(iftype);
  	}
  
  	for (i = 0; i < wiphy->n_iface_combinations; i++) {
  		const struct ieee80211_iface_combination *c;
  		struct ieee80211_iface_limit *limits;
  		u32 all_iftypes = 0;
  
  		c = &wiphy->iface_combinations[i];
  
  		if (num_interfaces > c->max_interfaces)
  			continue;

  		if (params->num_different_channels > c->num_different_channels)

  			continue;
  
  		limits = kmemdup(c->limits, sizeof(limits[0]) * c->n_limits,
  				 GFP_KERNEL);
  		if (!limits)
  			return -ENOMEM;
  
  		for (iftype = 0; iftype < NUM_NL80211_IFTYPES; iftype++) {
  			if (wiphy->software_iftypes & BIT(iftype))
  				continue;
  			for (j = 0; j < c->n_limits; j++) {
  				all_iftypes |= limits[j].types;
  				if (!(limits[j].types & BIT(iftype)))
  					continue;

  				if (limits[j].max < params->iftype_num[iftype])

  					goto cont;

  				limits[j].max -= params->iftype_num[iftype];

  			}
  		}

  		if (params->radar_detect !=
  			(c->radar_detect_widths & params->radar_detect))

  			goto cont;

  		if (params->radar_detect && c->radar_detect_regions &&

  		    !(c->radar_detect_regions & BIT(region)))
  			goto cont;

  		/* Finally check that all iftypes that we're currently
  		 * using are actually part of this combination. If they
  		 * aren't then we can't use this combination and have
  		 * to continue to the next.
  		 */
  		if ((all_iftypes & used_iftypes) != used_iftypes)
  			goto cont;

  		if (beacon_int_gcd) {

  			if (c->beacon_int_min_gcd &&

  			    beacon_int_gcd < c->beacon_int_min_gcd)

  				goto cont;

  			if (!c->beacon_int_min_gcd && beacon_int_different)

  				goto cont;
  		}

  		/* This combination covered all interface types and
  		 * supported the requested numbers, so we're good.
  		 */

  
  		(*iter)(c, data);

   cont:
  		kfree(limits);
  	}

  	return 0;
  }
  EXPORT_SYMBOL(cfg80211_iter_combinations);
  
  static void
  cfg80211_iter_sum_ifcombs(const struct ieee80211_iface_combination *c,
  			  void *data)
  {
  	int *num = data;
  	(*num)++;
  }
  
  int cfg80211_check_combinations(struct wiphy *wiphy,

  				struct iface_combination_params *params)

  {
  	int err, num = 0;

  	err = cfg80211_iter_combinations(wiphy, params,

  					 cfg80211_iter_sum_ifcombs, &num);
  	if (err)
  		return err;
  	if (num == 0)
  		return -EBUSY;
  
  	return 0;

  }
  EXPORT_SYMBOL(cfg80211_check_combinations);

  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;
  }

  unsigned int ieee80211_get_num_supported_channels(struct wiphy *wiphy)
  {

  	enum nl80211_band band;

  	unsigned int n_channels = 0;

  	for (band = 0; band < NUM_NL80211_BANDS; band++)

  		if (wiphy->bands[band])
  			n_channels += wiphy->bands[band]->n_channels;
  
  	return n_channels;
  }
  EXPORT_SYMBOL(ieee80211_get_num_supported_channels);

  int cfg80211_get_station(struct net_device *dev, const u8 *mac_addr,
  			 struct station_info *sinfo)
  {
  	struct cfg80211_registered_device *rdev;
  	struct wireless_dev *wdev;
  
  	wdev = dev->ieee80211_ptr;
  	if (!wdev)
  		return -EOPNOTSUPP;
  
  	rdev = wiphy_to_rdev(wdev->wiphy);
  	if (!rdev->ops->get_station)
  		return -EOPNOTSUPP;
  
  	return rdev_get_station(rdev, dev, mac_addr, sinfo);
  }
  EXPORT_SYMBOL(cfg80211_get_station);

  void cfg80211_free_nan_func(struct cfg80211_nan_func *f)
  {
  	int i;
  
  	if (!f)
  		return;
  
  	kfree(f->serv_spec_info);
  	kfree(f->srf_bf);
  	kfree(f->srf_macs);
  	for (i = 0; i < f->num_rx_filters; i++)
  		kfree(f->rx_filters[i].filter);
  
  	for (i = 0; i < f->num_tx_filters; i++)
  		kfree(f->tx_filters[i].filter);
  
  	kfree(f->rx_filters);
  	kfree(f->tx_filters);
  	kfree(f);
  }
  EXPORT_SYMBOL(cfg80211_free_nan_func);

  bool cfg80211_does_bw_fit_range(const struct ieee80211_freq_range *freq_range,
  				u32 center_freq_khz, u32 bw_khz)
  {
  	u32 start_freq_khz, end_freq_khz;
  
  	start_freq_khz = center_freq_khz - (bw_khz / 2);
  	end_freq_khz = center_freq_khz + (bw_khz / 2);
  
  	if (start_freq_khz >= freq_range->start_freq_khz &&
  	    end_freq_khz <= freq_range->end_freq_khz)
  		return true;
  
  	return false;
  }

  /* 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);

  
  bool cfg80211_is_gratuitous_arp_unsolicited_na(struct sk_buff *skb)
  {
      const struct ethhdr *eth = (void *)skb->data;
      const struct {
          struct arphdr hdr;
          u8 ar_sha[ETH_ALEN];
          u8 ar_sip[4];
          u8 ar_tha[ETH_ALEN];
          u8 ar_tip[4];
      } __packed *arp;
      const struct ipv6hdr *ipv6;
      const struct icmp6hdr *icmpv6;
  
      switch (eth->h_proto) {
      case cpu_to_be16(ETH_P_ARP):
          /* can't say - but will probably be dropped later anyway */
          if (!pskb_may_pull(skb, sizeof(*eth) + sizeof(*arp)))
              return false;
  
          arp = (void *)(eth + 1);
  
          if ((arp->hdr.ar_op == cpu_to_be16(ARPOP_REPLY) ||
               arp->hdr.ar_op == cpu_to_be16(ARPOP_REQUEST)) &&
              !memcmp(arp->ar_sip, arp->ar_tip, sizeof(arp->ar_sip)))
              return true;
          break;
      case cpu_to_be16(ETH_P_IPV6):
          /* can't say - but will probably be dropped later anyway */
          if (!pskb_may_pull(skb, sizeof(*eth) + sizeof(*ipv6) +
                      sizeof(*icmpv6)))
              return false;
  
          ipv6 = (void *)(eth + 1);
          icmpv6 = (void *)(ipv6 + 1);
  
          if (icmpv6->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT &&
              !memcmp(&ipv6->saddr, &ipv6->daddr, sizeof(ipv6->saddr)))
              return true;
          break;
      default:
          /*
           * no need to support other protocols, proxy service isn't
           * specified for any others
           */
          break;
      }
  
      return false;
  }
  EXPORT_SYMBOL(cfg80211_is_gratuitous_arp_unsolicited_na);