[MAC80211]: introduce util.c

Introduce a new file util.c and move a whole bunch of functions into it.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 463 insertions, 0 deletions

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
new file mode 100644
index 00000000000..c4565830947
--- /dev/null
+++ b/net/mac80211/util.c
@@ -0,0 +1,463 @@
+/*
+ * 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/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_ATHEROS_TURBO:
+			if (rate->rate == 120 || rate->rate == 240 ||
+			    rate->rate == 480)
+				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;
+		}
+
+		/* 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_ATHEROS_TURBO:
+			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;
+		}
+		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 ||
+	    local->hw.conf.phymode == MODE_ATHEROS_TURBO) {
+		/*
+		 * 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
+		 */
+		/* FIX: Atheros Turbo may have different (shorter) duration? */
+		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,
+					size_t frame_len, int rate)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+	u16 dur;
+	int erp;
+
+	erp = ieee80211_is_erp_rate(hw->conf.phymode, rate);
+	dur = ieee80211_frame_duration(local, frame_len, rate,
+				       erp, local->short_preamble);
+
+	return cpu_to_le16(dur);
+}
+EXPORT_SYMBOL(ieee80211_generic_frame_duration);
+
+__le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
+			      size_t frame_len,
+			      const struct ieee80211_tx_control *frame_txctl)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+	struct ieee80211_rate *rate;
+	int short_preamble = local->short_preamble;
+	int erp;
+	u16 dur;
+
+	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);
+
+	return cpu_to_le16(dur);
+}
+EXPORT_SYMBOL(ieee80211_rts_duration);
+
+__le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
+				    size_t frame_len,
+				    const struct ieee80211_tx_control *frame_txctl)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+	struct ieee80211_rate *rate;
+	int short_preamble = local->short_preamble;
+	int erp;
+	u16 dur;
+
+	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);
+	}
+
+	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);