path: root/net/wireless/util.c

/*
 * 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 <linux/if_vlan.h>
#include <linux/mpls.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 == IEEE80211_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 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 (chan <= 0)
		return 0; /* not supported */
	switch (band) {
	case IEEE80211_BAND_2GHZ:
		if (chan == 14)
			return 2484;
		else if (chan < 14)
			return 2407 + chan * 5;
		break;
	case IEEE80211_BAND_5GHZ:
		if (chan >= 182 && chan <= 196)
			return 4000 + chan * 5;
		else
			return 5000 + chan * 5;
		break;
	case IEEE80211_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 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_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 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)
			retur