| /* | 
 |  * 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 "ieee80211_i.h" | 
 | #include "ieee80211_rate.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[] = | 
 | 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 }; | 
 |  | 
 | /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */ | 
 | const unsigned char bridge_tunnel_header[] = | 
 | 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 }; | 
 |  | 
 | /* No encapsulation header if EtherType < 0x600 (=length) */ | 
 | static const unsigned char eapol_header[] = | 
 | 	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x88, 0x8e }; | 
 |  | 
 |  | 
 | static int rate_list_match(const int *rate_list, int rate) | 
 | { | 
 | 	int i; | 
 |  | 
 | 	if (!rate_list) | 
 | 		return 0; | 
 |  | 
 | 	for (i = 0; rate_list[i] >= 0; i++) | 
 | 		if (rate_list[i] == rate) | 
 | 			return 1; | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | void ieee80211_prepare_rates(struct ieee80211_local *local, | 
 | 			     struct ieee80211_hw_mode *mode) | 
 | { | 
 | 	int i; | 
 |  | 
 | 	for (i = 0; i < mode->num_rates; i++) { | 
 | 		struct ieee80211_rate *rate = &mode->rates[i]; | 
 |  | 
 | 		rate->flags &= ~(IEEE80211_RATE_SUPPORTED | | 
 | 				 IEEE80211_RATE_BASIC); | 
 |  | 
 | 		if (local->supp_rates[mode->mode]) { | 
 | 			if (!rate_list_match(local->supp_rates[mode->mode], | 
 | 					     rate->rate)) | 
 | 				continue; | 
 | 		} | 
 |  | 
 | 		rate->flags |= IEEE80211_RATE_SUPPORTED; | 
 |  | 
 | 		/* Use configured basic rate set if it is available. If not, | 
 | 		 * use defaults that are sane for most cases. */ | 
 | 		if (local->basic_rates[mode->mode]) { | 
 | 			if (rate_list_match(local->basic_rates[mode->mode], | 
 | 					    rate->rate)) | 
 | 				rate->flags |= IEEE80211_RATE_BASIC; | 
 | 		} else switch (mode->mode) { | 
 | 		case MODE_IEEE80211A: | 
 | 			if (rate->rate == 60 || rate->rate == 120 || | 
 | 			    rate->rate == 240) | 
 | 				rate->flags |= IEEE80211_RATE_BASIC; | 
 | 			break; | 
 | 		case MODE_IEEE80211B: | 
 | 			if (rate->rate == 10 || rate->rate == 20) | 
 | 				rate->flags |= IEEE80211_RATE_BASIC; | 
 | 			break; | 
 | 		case MODE_IEEE80211G: | 
 | 			if (rate->rate == 10 || rate->rate == 20 || | 
 | 			    rate->rate == 55 || rate->rate == 110) | 
 | 				rate->flags |= IEEE80211_RATE_BASIC; | 
 | 			break; | 
 | 		case NUM_IEEE80211_MODES: | 
 | 			/* not useful */ | 
 | 			break; | 
 | 		} | 
 |  | 
 | 		/* Set ERP and MANDATORY flags based on phymode */ | 
 | 		switch (mode->mode) { | 
 | 		case MODE_IEEE80211A: | 
 | 			if (rate->rate == 60 || rate->rate == 120 || | 
 | 			    rate->rate == 240) | 
 | 				rate->flags |= IEEE80211_RATE_MANDATORY; | 
 | 			break; | 
 | 		case MODE_IEEE80211B: | 
 | 			if (rate->rate == 10) | 
 | 				rate->flags |= IEEE80211_RATE_MANDATORY; | 
 | 			break; | 
 | 		case MODE_IEEE80211G: | 
 | 			if (rate->rate == 10 || rate->rate == 20 || | 
 | 			    rate->rate == 55 || rate->rate == 110 || | 
 | 			    rate->rate == 60 || rate->rate == 120 || | 
 | 			    rate->rate == 240) | 
 | 				rate->flags |= IEEE80211_RATE_MANDATORY; | 
 | 			break; | 
 | 		case NUM_IEEE80211_MODES: | 
 | 			/* not useful */ | 
 | 			break; | 
 | 		} | 
 | 		if (ieee80211_is_erp_rate(mode->mode, rate->rate)) | 
 | 			rate->flags |= IEEE80211_RATE_ERP; | 
 | 	} | 
 | } | 
 |  | 
 | u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len) | 
 | { | 
 | 	u16 fc; | 
 |  | 
 | 	if (len < 24) | 
 | 		return NULL; | 
 |  | 
 | 	fc = le16_to_cpu(hdr->frame_control); | 
 |  | 
 | 	switch (fc & IEEE80211_FCTL_FTYPE) { | 
 | 	case IEEE80211_FTYPE_DATA: | 
 | 		switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) { | 
 | 		case IEEE80211_FCTL_TODS: | 
 | 			return hdr->addr1; | 
 | 		case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS): | 
 | 			return NULL; | 
 | 		case IEEE80211_FCTL_FROMDS: | 
 | 			return hdr->addr2; | 
 | 		case 0: | 
 | 			return hdr->addr3; | 
 | 		} | 
 | 		break; | 
 | 	case IEEE80211_FTYPE_MGMT: | 
 | 		return hdr->addr3; | 
 | 	case IEEE80211_FTYPE_CTL: | 
 | 		if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL) | 
 | 			return hdr->addr1; | 
 | 		else | 
 | 			return NULL; | 
 | 	} | 
 |  | 
 | 	return NULL; | 
 | } | 
 |  | 
 | int ieee80211_get_hdrlen(u16 fc) | 
 | { | 
 | 	int hdrlen = 24; | 
 |  | 
 | 	switch (fc & IEEE80211_FCTL_FTYPE) { | 
 | 	case IEEE80211_FTYPE_DATA: | 
 | 		if ((fc & IEEE80211_FCTL_FROMDS) && (fc & IEEE80211_FCTL_TODS)) | 
 | 			hdrlen = 30; /* Addr4 */ | 
 | 		/* | 
 | 		 * The QoS Control field is two bytes and its presence is | 
 | 		 * indicated by the IEEE80211_STYPE_QOS_DATA bit. Add 2 to | 
 | 		 * hdrlen if that bit is set. | 
 | 		 * This works by masking out the bit and shifting it to | 
 | 		 * bit position 1 so the result has the value 0 or 2. | 
 | 		 */ | 
 | 		hdrlen += (fc & IEEE80211_STYPE_QOS_DATA) | 
 | 				>> (ilog2(IEEE80211_STYPE_QOS_DATA)-1); | 
 | 		break; | 
 | 	case IEEE80211_FTYPE_CTL: | 
 | 		/* | 
 | 		 * 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 & 0xE0) == 0xC0) | 
 | 			hdrlen = 10; | 
 | 		else | 
 | 			hdrlen = 16; | 
 | 		break; | 
 | 	} | 
 |  | 
 | 	return hdrlen; | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_get_hdrlen); | 
 |  | 
 | int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb) | 
 | { | 
 | 	const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *) skb->data; | 
 | 	int hdrlen; | 
 |  | 
 | 	if (unlikely(skb->len < 10)) | 
 | 		return 0; | 
 | 	hdrlen = ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control)); | 
 | 	if (unlikely(hdrlen > skb->len)) | 
 | 		return 0; | 
 | 	return hdrlen; | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb); | 
 |  | 
 | int ieee80211_is_eapol(const struct sk_buff *skb) | 
 | { | 
 | 	const struct ieee80211_hdr *hdr; | 
 | 	u16 fc; | 
 | 	int hdrlen; | 
 |  | 
 | 	if (unlikely(skb->len < 10)) | 
 | 		return 0; | 
 |  | 
 | 	hdr = (const struct ieee80211_hdr *) skb->data; | 
 | 	fc = le16_to_cpu(hdr->frame_control); | 
 |  | 
 | 	if (unlikely(!WLAN_FC_DATA_PRESENT(fc))) | 
 | 		return 0; | 
 |  | 
 | 	hdrlen = ieee80211_get_hdrlen(fc); | 
 |  | 
 | 	if (unlikely(skb->len >= hdrlen + sizeof(eapol_header) && | 
 | 		     memcmp(skb->data + hdrlen, eapol_header, | 
 | 			    sizeof(eapol_header)) == 0)) | 
 | 		return 1; | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | void ieee80211_tx_set_iswep(struct ieee80211_txrx_data *tx) | 
 | { | 
 | 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data; | 
 |  | 
 | 	hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); | 
 | 	if (tx->u.tx.extra_frag) { | 
 | 		struct ieee80211_hdr *fhdr; | 
 | 		int i; | 
 | 		for (i = 0; i < tx->u.tx.num_extra_frag; i++) { | 
 | 			fhdr = (struct ieee80211_hdr *) | 
 | 				tx->u.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.phymode == MODE_IEEE80211A || 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, int if_id, | 
 | 					size_t frame_len, int rate) | 
 | { | 
 | 	struct ieee80211_local *local = hw_to_local(hw); | 
 | 	struct net_device *bdev = dev_get_by_index(&init_net, if_id); | 
 | 	struct ieee80211_sub_if_data *sdata; | 
 | 	u16 dur; | 
 | 	int erp; | 
 |  | 
 | 	if (unlikely(!bdev)) | 
 | 		return 0; | 
 |  | 
 | 	sdata = IEEE80211_DEV_TO_SUB_IF(bdev); | 
 | 	erp = ieee80211_is_erp_rate(hw->conf.phymode, rate); | 
 | 	dur = ieee80211_frame_duration(local, frame_len, rate, | 
 | 		       erp, sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE); | 
 |  | 
 | 	dev_put(bdev); | 
 | 	return cpu_to_le16(dur); | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_generic_frame_duration); | 
 |  | 
 | __le16 ieee80211_rts_duration(struct ieee80211_hw *hw, int if_id, | 
 | 			      size_t frame_len, | 
 | 			      const struct ieee80211_tx_control *frame_txctl) | 
 | { | 
 | 	struct ieee80211_local *local = hw_to_local(hw); | 
 | 	struct ieee80211_rate *rate; | 
 | 	struct net_device *bdev = dev_get_by_index(&init_net, if_id); | 
 | 	struct ieee80211_sub_if_data *sdata; | 
 | 	int short_preamble; | 
 | 	int erp; | 
 | 	u16 dur; | 
 |  | 
 | 	if (unlikely(!bdev)) | 
 | 		return 0; | 
 |  | 
 | 	sdata = IEEE80211_DEV_TO_SUB_IF(bdev); | 
 | 	short_preamble = sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE; | 
 |  | 
 | 	rate = frame_txctl->rts_rate; | 
 | 	erp = !!(rate->flags & IEEE80211_RATE_ERP); | 
 |  | 
 | 	/* CTS duration */ | 
 | 	dur = ieee80211_frame_duration(local, 10, rate->rate, | 
 | 				       erp, short_preamble); | 
 | 	/* Data frame duration */ | 
 | 	dur += ieee80211_frame_duration(local, frame_len, rate->rate, | 
 | 					erp, short_preamble); | 
 | 	/* ACK duration */ | 
 | 	dur += ieee80211_frame_duration(local, 10, rate->rate, | 
 | 					erp, short_preamble); | 
 |  | 
 | 	dev_put(bdev); | 
 | 	return cpu_to_le16(dur); | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_rts_duration); | 
 |  | 
 | __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw, int if_id, | 
 | 				    size_t frame_len, | 
 | 				    const struct ieee80211_tx_control *frame_txctl) | 
 | { | 
 | 	struct ieee80211_local *local = hw_to_local(hw); | 
 | 	struct ieee80211_rate *rate; | 
 | 	struct net_device *bdev = dev_get_by_index(&init_net, if_id); | 
 | 	struct ieee80211_sub_if_data *sdata; | 
 | 	int short_preamble; | 
 | 	int erp; | 
 | 	u16 dur; | 
 |  | 
 | 	if (unlikely(!bdev)) | 
 | 		return 0; | 
 |  | 
 | 	sdata = IEEE80211_DEV_TO_SUB_IF(bdev); | 
 | 	short_preamble = sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE; | 
 |  | 
 | 	rate = frame_txctl->rts_rate; | 
 | 	erp = !!(rate->flags & IEEE80211_RATE_ERP); | 
 |  | 
 | 	/* Data frame duration */ | 
 | 	dur = ieee80211_frame_duration(local, frame_len, rate->rate, | 
 | 				       erp, short_preamble); | 
 | 	if (!(frame_txctl->flags & IEEE80211_TXCTL_NO_ACK)) { | 
 | 		/* ACK duration */ | 
 | 		dur += ieee80211_frame_duration(local, 10, rate->rate, | 
 | 						erp, short_preamble); | 
 | 	} | 
 |  | 
 | 	dev_put(bdev); | 
 | 	return cpu_to_le16(dur); | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_ctstoself_duration); | 
 |  | 
 | struct ieee80211_rate * | 
 | ieee80211_get_rate(struct ieee80211_local *local, int phymode, int hw_rate) | 
 | { | 
 | 	struct ieee80211_hw_mode *mode; | 
 | 	int r; | 
 |  | 
 | 	list_for_each_entry(mode, &local->modes_list, list) { | 
 | 		if (mode->mode != phymode) | 
 | 			continue; | 
 | 		for (r = 0; r < mode->num_rates; r++) { | 
 | 			struct ieee80211_rate *rate = &mode->rates[r]; | 
 | 			if (rate->val == hw_rate || | 
 | 			    (rate->flags & IEEE80211_RATE_PREAMBLE2 && | 
 | 			     rate->val2 == hw_rate)) | 
 | 				return rate; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	return NULL; | 
 | } | 
 |  | 
 | void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue) | 
 | { | 
 | 	struct ieee80211_local *local = hw_to_local(hw); | 
 |  | 
 | 	if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF, | 
 | 			       &local->state[queue])) { | 
 | 		if (test_bit(IEEE80211_LINK_STATE_PENDING, | 
 | 			     &local->state[queue])) | 
 | 			tasklet_schedule(&local->tx_pending_tasklet); | 
 | 		else | 
 | 			if (!ieee80211_qdisc_installed(local->mdev)) { | 
 | 				if (queue == 0) | 
 | 					netif_wake_queue(local->mdev); | 
 | 			} else | 
 | 				__netif_schedule(local->mdev); | 
 | 	} | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_wake_queue); | 
 |  | 
 | void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue) | 
 | { | 
 | 	struct ieee80211_local *local = hw_to_local(hw); | 
 |  | 
 | 	if (!ieee80211_qdisc_installed(local->mdev) && queue == 0) | 
 | 		netif_stop_queue(local->mdev); | 
 | 	set_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]); | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_stop_queue); | 
 |  | 
 | void ieee80211_start_queues(struct ieee80211_hw *hw) | 
 | { | 
 | 	struct ieee80211_local *local = hw_to_local(hw); | 
 | 	int i; | 
 |  | 
 | 	for (i = 0; i < local->hw.queues; i++) | 
 | 		clear_bit(IEEE80211_LINK_STATE_XOFF, &local->state[i]); | 
 | 	if (!ieee80211_qdisc_installed(local->mdev)) | 
 | 		netif_start_queue(local->mdev); | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_start_queues); | 
 |  | 
 | void ieee80211_stop_queues(struct ieee80211_hw *hw) | 
 | { | 
 | 	int i; | 
 |  | 
 | 	for (i = 0; i < hw->queues; i++) | 
 | 		ieee80211_stop_queue(hw, i); | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_stop_queues); | 
 |  | 
 | void ieee80211_wake_queues(struct ieee80211_hw *hw) | 
 | { | 
 | 	int i; | 
 |  | 
 | 	for (i = 0; i < hw->queues; i++) | 
 | 		ieee80211_wake_queue(hw, i); | 
 | } | 
 | EXPORT_SYMBOL(ieee80211_wake_queues); |