diff options
Diffstat (limited to 'net/mac80211/util.c')
-rw-r--r-- | net/mac80211/util.c | 463 |
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); |