[MAC80211]: split TX path into own file
authorJohannes Berg <johannes@sipsolutions.net>
Fri, 27 Jul 2007 13:43:22 +0000 (15:43 +0200)
committerDavid S. Miller <davem@sunset.davemloft.net>
Wed, 10 Oct 2007 23:47:33 +0000 (16:47 -0700)
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>
net/mac80211/Makefile
net/mac80211/ieee80211.c
net/mac80211/ieee80211_i.h
net/mac80211/tx.c [new file with mode: 0644]

index 0353e75..8482602 100644 (file)
@@ -19,4 +19,5 @@ mac80211-objs := \
        aes_ccm.o \
        ieee80211_cfg.o \
        rx.o \
+       tx.o \
        $(mac80211-objs-y)
index c009420..a35e3a9 100644 (file)
@@ -24,7 +24,6 @@
 #include <linux/compiler.h>
 #include <linux/bitmap.h>
 #include <net/cfg80211.h>
-#include <asm/unaligned.h>
 
 #include "ieee80211_common.h"
 #include "ieee80211_i.h"
@@ -68,16 +67,6 @@ struct ieee80211_tx_status_rtap_hdr {
 } __attribute__ ((packed));
 
 
-static inline void ieee80211_include_sequence(struct ieee80211_sub_if_data *sdata,
-                                             struct ieee80211_hdr *hdr)
-{
-       /* Set the sequence number for this frame. */
-       hdr->seq_ctrl = cpu_to_le16(sdata->sequence);
-
-       /* Increase the sequence number. */
-       sdata->sequence = (sdata->sequence + 0x10) & IEEE80211_SCTL_SEQ;
-}
-
 struct ieee80211_key_conf *
 ieee80211_key_data2conf(struct ieee80211_local *local,
                        const struct ieee80211_key *data)
@@ -286,1833 +275,181 @@ u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len)
                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);
-
-
-#ifdef CONFIG_MAC80211_LOWTX_FRAME_DUMP
-static void ieee80211_dump_frame(const char *ifname, const char *title,
-                                const struct sk_buff *skb)
-{
-       const struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
-       u16 fc;
-       int hdrlen;
-
-       printk(KERN_DEBUG "%s: %s (len=%d)", ifname, title, skb->len);
-       if (skb->len < 4) {
-               printk("\n");
-               return;
-       }
-
-       fc = le16_to_cpu(hdr->frame_control);
-       hdrlen = ieee80211_get_hdrlen(fc);
-       if (hdrlen > skb->len)
-               hdrlen = skb->len;
-       if (hdrlen >= 4)
-               printk(" FC=0x%04x DUR=0x%04x",
-                      fc, le16_to_cpu(hdr->duration_id));
-       if (hdrlen >= 10)
-               printk(" A1=" MAC_FMT, MAC_ARG(hdr->addr1));
-       if (hdrlen >= 16)
-               printk(" A2=" MAC_FMT, MAC_ARG(hdr->addr2));
-       if (hdrlen >= 24)
-               printk(" A3=" MAC_FMT, MAC_ARG(hdr->addr3));
-       if (hdrlen >= 30)
-               printk(" A4=" MAC_FMT, MAC_ARG(hdr->addr4));
-       printk("\n");
-}
-#else /* CONFIG_MAC80211_LOWTX_FRAME_DUMP */
-static inline void ieee80211_dump_frame(const char *ifname, const char *title,
-                                       struct sk_buff *skb)
-{
-}
-#endif /* CONFIG_MAC80211_LOWTX_FRAME_DUMP */
-
-
-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;
-}
-
-
-static ieee80211_txrx_result
-ieee80211_tx_h_rate_ctrl(struct ieee80211_txrx_data *tx)
-{
-       struct rate_control_extra extra;
-
-       memset(&extra, 0, sizeof(extra));
-       extra.mode = tx->u.tx.mode;
-       extra.mgmt_data = tx->sdata &&
-               tx->sdata->type == IEEE80211_IF_TYPE_MGMT;
-       extra.ethertype = tx->ethertype;
-
-       tx->u.tx.rate = rate_control_get_rate(tx->local, tx->dev, tx->skb,
-                                             &extra);
-       if (unlikely(extra.probe != NULL)) {
-               tx->u.tx.control->flags |= IEEE80211_TXCTL_RATE_CTRL_PROBE;
-               tx->u.tx.probe_last_frag = 1;
-               tx->u.tx.control->alt_retry_rate = tx->u.tx.rate->val;
-               tx->u.tx.rate = extra.probe;
-       } else {
-               tx->u.tx.control->alt_retry_rate = -1;
-       }
-       if (!tx->u.tx.rate)
-               return TXRX_DROP;
-       if (tx->u.tx.mode->mode == MODE_IEEE80211G &&
-           tx->sdata->use_protection && tx->fragmented &&
-           extra.nonerp) {
-               tx->u.tx.last_frag_rate = tx->u.tx.rate;
-               tx->u.tx.probe_last_frag = extra.probe ? 1 : 0;
-
-               tx->u.tx.rate = extra.nonerp;
-               tx->u.tx.control->rate = extra.nonerp;
-               tx->u.tx.control->flags &= ~IEEE80211_TXCTL_RATE_CTRL_PROBE;
-       } else {
-               tx->u.tx.last_frag_rate = tx->u.tx.rate;
-               tx->u.tx.control->rate = tx->u.tx.rate;
-       }
-       tx->u.tx.control->tx_rate = tx->u.tx.rate->val;
-       if ((tx->u.tx.rate->flags & IEEE80211_RATE_PREAMBLE2) &&
-           tx->local->short_preamble &&
-           (!tx->sta || (tx->sta->flags & WLAN_STA_SHORT_PREAMBLE))) {
-               tx->u.tx.short_preamble = 1;
-               tx->u.tx.control->tx_rate = tx->u.tx.rate->val2;
-       }
-
-       return TXRX_CONTINUE;
-}
-
-
-static ieee80211_txrx_result
-ieee80211_tx_h_select_key(struct ieee80211_txrx_data *tx)
-{
-       if (tx->sta)
-               tx->u.tx.control->key_idx = tx->sta->key_idx_compression;
-       else
-               tx->u.tx.control->key_idx = HW_KEY_IDX_INVALID;
-
-       if (unlikely(tx->u.tx.control->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT))
-               tx->key = NULL;
-       else if (tx->sta && tx->sta->key)
-               tx->key = tx->sta->key;
-       else if (tx->sdata->default_key)
-               tx->key = tx->sdata->default_key;
-       else if (tx->sdata->drop_unencrypted &&
-                !(tx->sdata->eapol && ieee80211_is_eapol(tx->skb))) {
-               I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
-               return TXRX_DROP;
-       } else
-               tx->key = NULL;
-
-       if (tx->key) {
-               tx->key->tx_rx_count++;
-               if (unlikely(tx->local->key_tx_rx_threshold &&
-                            tx->key->tx_rx_count >
-                            tx->local->key_tx_rx_threshold)) {
-                       ieee80211_key_threshold_notify(tx->dev, tx->key,
-                                                      tx->sta);
-               }
-       }
-
-       return TXRX_CONTINUE;
-}
-
-
-static ieee80211_txrx_result
-ieee80211_tx_h_fragment(struct ieee80211_txrx_data *tx)
-{
-       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
-       size_t hdrlen, per_fragm, num_fragm, payload_len, left;
-       struct sk_buff **frags, *first, *frag;
-       int i;
-       u16 seq;
-       u8 *pos;
-       int frag_threshold = tx->local->fragmentation_threshold;
-
-       if (!tx->fragmented)
-               return TXRX_CONTINUE;
-
-       first = tx->skb;
-
-       hdrlen = ieee80211_get_hdrlen(tx->fc);
-       payload_len = first->len - hdrlen;
-       per_fragm = frag_threshold - hdrlen - FCS_LEN;
-       num_fragm = (payload_len + per_fragm - 1) / per_fragm;
-
-       frags = kzalloc(num_fragm * sizeof(struct sk_buff *), GFP_ATOMIC);
-       if (!frags)
-               goto fail;
-
-       hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
-       seq = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_SEQ;
-       pos = first->data + hdrlen + per_fragm;
-       left = payload_len - per_fragm;
-       for (i = 0; i < num_fragm - 1; i++) {
-               struct ieee80211_hdr *fhdr;
-               size_t copylen;
-
-               if (left <= 0)
-                       goto fail;
-
-               /* reserve enough extra head and tail room for possible
-                * encryption */
-               frag = frags[i] =
-                       dev_alloc_skb(tx->local->tx_headroom +
-                                     frag_threshold +
-                                     IEEE80211_ENCRYPT_HEADROOM +
-                                     IEEE80211_ENCRYPT_TAILROOM);
-               if (!frag)
-                       goto fail;
-               /* Make sure that all fragments use the same priority so
-                * that they end up using the same TX queue */
-               frag->priority = first->priority;
-               skb_reserve(frag, tx->local->tx_headroom +
-                                 IEEE80211_ENCRYPT_HEADROOM);
-               fhdr = (struct ieee80211_hdr *) skb_put(frag, hdrlen);
-               memcpy(fhdr, first->data, hdrlen);
-               if (i == num_fragm - 2)
-                       fhdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREFRAGS);
-               fhdr->seq_ctrl = cpu_to_le16(seq | ((i + 1) & IEEE80211_SCTL_FRAG));
-               copylen = left > per_fragm ? per_fragm : left;
-               memcpy(skb_put(frag, copylen), pos, copylen);
-
-               pos += copylen;
-               left -= copylen;
-       }
-       skb_trim(first, hdrlen + per_fragm);
-
-       tx->u.tx.num_extra_frag = num_fragm - 1;
-       tx->u.tx.extra_frag = frags;
-
-       return TXRX_CONTINUE;
-
- fail:
-       printk(KERN_DEBUG "%s: failed to fragment frame\n", tx->dev->name);
-       if (frags) {
-               for (i = 0; i < num_fragm - 1; i++)
-                       if (frags[i])
-                               dev_kfree_skb(frags[i]);
-               kfree(frags);
-       }
-       I802_DEBUG_INC(tx->local->tx_handlers_drop_fragment);
-       return TXRX_DROP;
-}
-
-
-static int wep_encrypt_skb(struct ieee80211_txrx_data *tx, struct sk_buff *skb)
-{
-       if (tx->key->force_sw_encrypt) {
-               if (ieee80211_wep_encrypt(tx->local, skb, tx->key))
-                       return -1;
-       } else {
-               tx->u.tx.control->key_idx = tx->key->hw_key_idx;
-               if (tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) {
-                       if (ieee80211_wep_add_iv(tx->local, skb, tx->key) ==
-                           NULL)
-                               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);
-               }
-       }
-}
-
-
-static ieee80211_txrx_result
-ieee80211_tx_h_wep_encrypt(struct ieee80211_txrx_data *tx)
-{
-       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
-       u16 fc;
-
-       fc = le16_to_cpu(hdr->frame_control);
-
-       if (!tx->key || tx->key->alg != ALG_WEP ||
-           ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
-            ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
-             (fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)))
-               return TXRX_CONTINUE;
-
-       tx->u.tx.control->iv_len = WEP_IV_LEN;
-       tx->u.tx.control->icv_len = WEP_ICV_LEN;
-       ieee80211_tx_set_iswep(tx);
-
-       if (wep_encrypt_skb(tx, tx->skb) < 0) {
-               I802_DEBUG_INC(tx->local->tx_handlers_drop_wep);
-               return TXRX_DROP;
-       }
-
-       if (tx->u.tx.extra_frag) {
-               int i;
-               for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
-                       if (wep_encrypt_skb(tx, tx->u.tx.extra_frag[i]) < 0) {
-                               I802_DEBUG_INC(tx->local->
-                                              tx_handlers_drop_wep);
-                               return TXRX_DROP;
-                       }
-               }
-       }
-
-       return TXRX_CONTINUE;
-}
-
-
-static 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);
-
-
-static u16 ieee80211_duration(struct ieee80211_txrx_data *tx, int group_addr,
-                             int next_frag_len)
-{
-       int rate, mrate, erp, dur, i;
-       struct ieee80211_rate *txrate = tx->u.tx.rate;
-       struct ieee80211_local *local = tx->local;
-       struct ieee80211_hw_mode *mode = tx->u.tx.mode;
-
-       erp = txrate->flags & IEEE80211_RATE_ERP;
-
-       /*
-        * data and mgmt (except PS Poll):
-        * - during CFP: 32768
-        * - during contention period:
-        *   if addr1 is group address: 0
-        *   if more fragments = 0 and addr1 is individual address: time to
-        *      transmit one ACK plus SIFS
-        *   if more fragments = 1 and addr1 is individual address: time to
-        *      transmit next fragment plus 2 x ACK plus 3 x SIFS
-        *
-        * IEEE 802.11, 9.6:
-        * - control response frame (CTS or ACK) shall be transmitted using the
-        *   same rate as the immediately previous frame in the frame exchange
-        *   sequence, if this rate belongs to the PHY mandatory rates, or else
-        *   at the highest possible rate belonging to the PHY rates in the
-        *   BSSBasicRateSet
-        */
-
-       if ((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL) {
-               /* TODO: These control frames are not currently sent by
-                * 80211.o, but should they be implemented, this function
-                * needs to be updated to support duration field calculation.
-                *
-                * RTS: time needed to transmit pending data/mgmt frame plus
-                *    one CTS frame plus one ACK frame plus 3 x SIFS
-                * CTS: duration of immediately previous RTS minus time
-                *    required to transmit CTS and its SIFS
-                * ACK: 0 if immediately previous directed data/mgmt had
-                *    more=0, with more=1 duration in ACK frame is duration
-                *    from previous frame minus time needed to transmit ACK
-                *    and its SIFS
-                * PS Poll: BIT(15) | BIT(14) | aid
-                */
-               return 0;
-       }
-
-       /* data/mgmt */
-       if (0 /* FIX: data/mgmt during CFP */)
-               return 32768;
-
-       if (group_addr) /* Group address as the destination - no ACK */
-               return 0;
-
-       /* Individual destination address:
-        * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
-        * CTS and ACK frames shall be transmitted using the highest rate in
-        * basic rate set that is less than or equal to the rate of the
-        * immediately previous frame and that is using the same modulation
-        * (CCK or OFDM). If no basic rate set matches with these requirements,
-        * the highest mandatory rate of the PHY that is less than or equal to
-        * the rate of the previous frame is used.
-        * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
-        */
-       rate = -1;
-       mrate = 10; /* use 1 Mbps if everything fails */
-       for (i = 0; i < mode->num_rates; i++) {
-               struct ieee80211_rate *r = &mode->rates[i];
-               if (r->rate > txrate->rate)
-                       break;
-
-               if (IEEE80211_RATE_MODULATION(txrate->flags) !=
-                   IEEE80211_RATE_MODULATION(r->flags))
-                       continue;
-
-               if (r->flags & IEEE80211_RATE_BASIC)
-                       rate = r->rate;
-               else if (r->flags & IEEE80211_RATE_MANDATORY)
-                       mrate = r->rate;
-       }
-       if (rate == -1) {
-               /* No matching basic rate found; use highest suitable mandatory
-                * PHY rate */
-               rate = mrate;
-       }
-
-       /* Time needed to transmit ACK
-        * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
-        * to closest integer */
-
-       dur = ieee80211_frame_duration(local, 10, rate, erp,
-                                      local->short_preamble);
-
-       if (next_frag_len) {
-               /* Frame is fragmented: duration increases with time needed to
-                * transmit next fragment plus ACK and 2 x SIFS. */
-               dur *= 2; /* ACK + SIFS */
-               /* next fragment */
-               dur += ieee80211_frame_duration(local, next_frag_len,
-                                               txrate->rate, erp,
-                                               local->short_preamble);
-       }
-
-       return dur;
-}
-
-
-static ieee80211_txrx_result
-ieee80211_tx_h_misc(struct ieee80211_txrx_data *tx)
-{
-       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
-       u16 dur;
-       struct ieee80211_tx_control *control = tx->u.tx.control;
-       struct ieee80211_hw_mode *mode = tx->u.tx.mode;
-
-       if (!is_multicast_ether_addr(hdr->addr1)) {
-               if (tx->skb->len + FCS_LEN > tx->local->rts_threshold &&
-                   tx->local->rts_threshold < IEEE80211_MAX_RTS_THRESHOLD) {
-                       control->flags |= IEEE80211_TXCTL_USE_RTS_CTS;
-                       control->retry_limit =
-                               tx->local->long_retry_limit;
-               } else {
-                       control->retry_limit =
-                               tx->local->short_retry_limit;
-               }
-       } else {
-               control->retry_limit = 1;
-       }
-
-       if (tx->fragmented) {
-               /* Do not use multiple retry rates when sending fragmented
-                * frames.
-                * TODO: The last fragment could still use multiple retry
-                * rates. */
-               control->alt_retry_rate = -1;
-       }
-
-       /* Use CTS protection for unicast frames sent using extended rates if
-        * there are associated non-ERP stations and RTS/CTS is not configured
-        * for the frame. */
-       if (mode->mode == MODE_IEEE80211G &&
-           (tx->u.tx.rate->flags & IEEE80211_RATE_ERP) &&
-           tx->u.tx.unicast && tx->sdata->use_protection &&
-           !(control->flags & IEEE80211_TXCTL_USE_RTS_CTS))
-               control->flags |= IEEE80211_TXCTL_USE_CTS_PROTECT;
-
-       /* Setup duration field for the first fragment of the frame. Duration
-        * for remaining fragments will be updated when they are being sent
-        * to low-level driver in ieee80211_tx(). */
-       dur = ieee80211_duration(tx, is_multicast_ether_addr(hdr->addr1),
-                                tx->fragmented ? tx->u.tx.extra_frag[0]->len :
-                                0);
-       hdr->duration_id = cpu_to_le16(dur);
-
-       if ((control->flags & IEEE80211_TXCTL_USE_RTS_CTS) ||
-           (control->flags & IEEE80211_TXCTL_USE_CTS_PROTECT)) {
-               struct ieee80211_rate *rate;
-
-               /* Do not use multiple retry rates when using RTS/CTS */
-               control->alt_retry_rate = -1;
-
-               /* Use min(data rate, max base rate) as CTS/RTS rate */
-               rate = tx->u.tx.rate;
-               while (rate > mode->rates &&
-                      !(rate->flags & IEEE80211_RATE_BASIC))
-                       rate--;
-
-               control->rts_cts_rate = rate->val;
-               control->rts_rate = rate;
-       }
-
-       if (tx->sta) {
-               tx->sta->tx_packets++;
-               tx->sta->tx_fragments++;
-               tx->sta->tx_bytes += tx->skb->len;
-               if (tx->u.tx.extra_frag) {
-                       int i;
-                       tx->sta->tx_fragments += tx->u.tx.num_extra_frag;
-                       for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
-                               tx->sta->tx_bytes +=
-                                       tx->u.tx.extra_frag[i]->len;
-                       }
-               }
-       }
-
-       return TXRX_CONTINUE;
-}
-
-
-static ieee80211_txrx_result
-ieee80211_tx_h_check_assoc(struct ieee80211_txrx_data *tx)
-{
-#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
-       struct sk_buff *skb = tx->skb;
-       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
-#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
-       u32 sta_flags;
-
-       if (unlikely(tx->local->sta_scanning != 0) &&
-           ((tx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
-            (tx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PROBE_REQ))
-               return TXRX_DROP;
-
-       if (tx->u.tx.ps_buffered)
-               return TXRX_CONTINUE;
-
-       sta_flags = tx->sta ? tx->sta->flags : 0;
-
-       if (likely(tx->u.tx.unicast)) {
-               if (unlikely(!(sta_flags & WLAN_STA_ASSOC) &&
-                            tx->sdata->type != IEEE80211_IF_TYPE_IBSS &&
-                            (tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)) {
-#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
-                       printk(KERN_DEBUG "%s: dropped data frame to not "
-                              "associated station " MAC_FMT "\n",
-                              tx->dev->name, MAC_ARG(hdr->addr1));
-#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
-                       I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
-                       return TXRX_DROP;
-               }
-       } else {
-               if (unlikely((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
-                            tx->local->num_sta == 0 &&
-                            !tx->local->allow_broadcast_always &&
-                            tx->sdata->type != IEEE80211_IF_TYPE_IBSS)) {
-                       /*
-                        * No associated STAs - no need to send multicast
-                        * frames.
-                        */
-                       return TXRX_DROP;
-               }
-               return TXRX_CONTINUE;
-       }
-
-       if (unlikely(!tx->u.tx.mgmt_interface && tx->sdata->ieee802_1x &&
-                    !(sta_flags & WLAN_STA_AUTHORIZED))) {
-#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
-               printk(KERN_DEBUG "%s: dropped frame to " MAC_FMT
-                      " (unauthorized port)\n", tx->dev->name,
-                      MAC_ARG(hdr->addr1));
-#endif
-               I802_DEBUG_INC(tx->local->tx_handlers_drop_unauth_port);
-               return TXRX_DROP;
-       }
-
-       return TXRX_CONTINUE;
-}
-
-static ieee80211_txrx_result
-ieee80211_tx_h_sequence(struct ieee80211_txrx_data *tx)
-{
-       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
-
-       if (ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control)) >= 24)
-               ieee80211_include_sequence(tx->sdata, hdr);
-
-       return TXRX_CONTINUE;
-}
-
-/* This function is called whenever the AP is about to exceed the maximum limit
- * of buffered frames for power saving STAs. This situation should not really
- * happen often during normal operation, so dropping the oldest buffered packet
- * from each queue should be OK to make some room for new frames. */
-static void purge_old_ps_buffers(struct ieee80211_local *local)
-{
-       int total = 0, purged = 0;
-       struct sk_buff *skb;
-       struct ieee80211_sub_if_data *sdata;
-       struct sta_info *sta;
-
-       read_lock(&local->sub_if_lock);
-       list_for_each_entry(sdata, &local->sub_if_list, list) {
-               struct ieee80211_if_ap *ap;
-               if (sdata->dev == local->mdev ||
-                   sdata->type != IEEE80211_IF_TYPE_AP)
-                       continue;
-               ap = &sdata->u.ap;
-               skb = skb_dequeue(&ap->ps_bc_buf);
-               if (skb) {
-                       purged++;
-                       dev_kfree_skb(skb);
-               }
-               total += skb_queue_len(&ap->ps_bc_buf);
-       }
-       read_unlock(&local->sub_if_lock);
-
-       spin_lock_bh(&local->sta_lock);
-       list_for_each_entry(sta, &local->sta_list, list) {
-               skb = skb_dequeue(&sta->ps_tx_buf);
-               if (skb) {
-                       purged++;
-                       dev_kfree_skb(skb);
-               }
-               total += skb_queue_len(&sta->ps_tx_buf);
-       }
-       spin_unlock_bh(&local->sta_lock);
-
-       local->total_ps_buffered = total;
-       printk(KERN_DEBUG "%s: PS buffers full - purged %d frames\n",
-              local->mdev->name, purged);
-}
-
-
-static inline ieee80211_txrx_result
-ieee80211_tx_h_multicast_ps_buf(struct ieee80211_txrx_data *tx)
-{
-       /* broadcast/multicast frame */
-       /* If any of the associated stations is in power save mode,
-        * the frame is buffered to be sent after DTIM beacon frame */
-       if ((tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING) &&
-           tx->sdata->type != IEEE80211_IF_TYPE_WDS &&
-           tx->sdata->bss && atomic_read(&tx->sdata->bss->num_sta_ps) &&
-           !(tx->fc & IEEE80211_FCTL_ORDER)) {
-               if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
-                       purge_old_ps_buffers(tx->local);
-               if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >=
-                   AP_MAX_BC_BUFFER) {
-                       if (net_ratelimit()) {
-                               printk(KERN_DEBUG "%s: BC TX buffer full - "
-                                      "dropping the oldest frame\n",
-                                      tx->dev->name);
-                       }
-                       dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
-               } else
-                       tx->local->total_ps_buffered++;
-               skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
-               return TXRX_QUEUED;
-       }
-
-       return TXRX_CONTINUE;
-}
-
-
-static inline ieee80211_txrx_result
-ieee80211_tx_h_unicast_ps_buf(struct ieee80211_txrx_data *tx)
-{
-       struct sta_info *sta = tx->sta;
-
-       if (unlikely(!sta ||
-                    ((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT &&
-                     (tx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PROBE_RESP)))
-               return TXRX_CONTINUE;
-
-       if (unlikely((sta->flags & WLAN_STA_PS) && !sta->pspoll)) {
-               struct ieee80211_tx_packet_data *pkt_data;
-#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
-               printk(KERN_DEBUG "STA " MAC_FMT " aid %d: PS buffer (entries "
-                      "before %d)\n",
-                      MAC_ARG(sta->addr), sta->aid,
-                      skb_queue_len(&sta->ps_tx_buf));
-#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
-               sta->flags |= WLAN_STA_TIM;
-               if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
-                       purge_old_ps_buffers(tx->local);
-               if (skb_queue_len(&sta->ps_tx_buf) >= STA_MAX_TX_BUFFER) {
-                       struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf);
-                       if (net_ratelimit()) {
-                               printk(KERN_DEBUG "%s: STA " MAC_FMT " TX "
-                                      "buffer full - dropping oldest frame\n",
-                                      tx->dev->name, MAC_ARG(sta->addr));
-                       }
-                       dev_kfree_skb(old);
-               } else
-                       tx->local->total_ps_buffered++;
-               /* Queue frame to be sent after STA sends an PS Poll frame */
-               if (skb_queue_empty(&sta->ps_tx_buf)) {
-                       if (tx->local->ops->set_tim)
-                               tx->local->ops->set_tim(local_to_hw(tx->local),
-                                                      sta->aid, 1);
-                       if (tx->sdata->bss)
-                               bss_tim_set(tx->local, tx->sdata->bss, sta->aid);
-               }
-               pkt_data = (struct ieee80211_tx_packet_data *)tx->skb->cb;
-               pkt_data->jiffies = jiffies;
-               skb_queue_tail(&sta->ps_tx_buf, tx->skb);
-               return TXRX_QUEUED;
-       }
-#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
-       else if (unlikely(sta->flags & WLAN_STA_PS)) {
-               printk(KERN_DEBUG "%s: STA " MAC_FMT " in PS mode, but pspoll "
-                      "set -> send frame\n", tx->dev->name,
-                      MAC_ARG(sta->addr));
-       }
-#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
-       sta->pspoll = 0;
-
-       return TXRX_CONTINUE;
-}
-
-
-static ieee80211_txrx_result
-ieee80211_tx_h_ps_buf(struct ieee80211_txrx_data *tx)
-{
-       if (unlikely(tx->u.tx.ps_buffered))
-               return TXRX_CONTINUE;
-
-       if (tx->u.tx.unicast)
-               return ieee80211_tx_h_unicast_ps_buf(tx);
-       else
-               return ieee80211_tx_h_multicast_ps_buf(tx);
-}
-
-
-/*
- * deal with packet injection down monitor interface
- * with Radiotap Header -- only called for monitor mode interface
- */
-
-static ieee80211_txrx_result
-__ieee80211_parse_tx_radiotap(
-       struct ieee80211_txrx_data *tx,
-       struct sk_buff *skb, struct ieee80211_tx_control *control)
-{
-       /*
-        * this is the moment to interpret and discard the radiotap header that
-        * must be at the start of the packet injected in Monitor mode
-        *
-        * Need to take some care with endian-ness since radiotap
-        * args are little-endian
-        */
-
-       struct ieee80211_radiotap_iterator iterator;
-       struct ieee80211_radiotap_header *rthdr =
-               (struct ieee80211_radiotap_header *) skb->data;
-       struct ieee80211_hw_mode *mode = tx->local->hw.conf.mode;
-       int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len);
-
-       /*
-        * default control situation for all injected packets
-        * FIXME: this does not suit all usage cases, expand to allow control
-        */
-
-       control->retry_limit = 1; /* no retry */
-       control->key_idx = -1; /* no encryption key */
-       control->flags &= ~(IEEE80211_TXCTL_USE_RTS_CTS |
-                           IEEE80211_TXCTL_USE_CTS_PROTECT);
-       control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT |
-                         IEEE80211_TXCTL_NO_ACK;
-       control->antenna_sel_tx = 0; /* default to default antenna */
-
-       /*
-        * for every radiotap entry that is present
-        * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
-        * entries present, or -EINVAL on error)
-        */
-
-       while (!ret) {
-               int i, target_rate;
-
-               ret = ieee80211_radiotap_iterator_next(&iterator);
-
-               if (ret)
-                       continue;
-
-               /* see if this argument is something we can use */
-               switch (iterator.this_arg_index) {
-               /*
-                * You must take care when dereferencing iterator.this_arg
-                * for multibyte types... the pointer is not aligned.  Use
-                * get_unaligned((type *)iterator.this_arg) to dereference
-                * iterator.this_arg for type "type" safely on all arches.
-               */
-               case IEEE80211_RADIOTAP_RATE:
-                       /*
-                        * radiotap rate u8 is in 500kbps units eg, 0x02=1Mbps
-                        * ieee80211 rate int is in 100kbps units eg, 0x0a=1Mbps
-                        */
-                       target_rate = (*iterator.this_arg) * 5;
-                       for (i = 0; i < mode->num_rates; i++) {
-                               struct ieee80211_rate *r = &mode->rates[i];
-
-                               if (r->rate > target_rate)
-                                       continue;
-
-                               control->rate = r;
-
-                               if (r->flags & IEEE80211_RATE_PREAMBLE2)
-                                       control->tx_rate = r->val2;
-                               else
-                                       control->tx_rate = r->val;
-
-                               /* end on exact match */
-                               if (r->rate == target_rate)
-                                       i = mode->num_rates;
-                       }
-                       break;
-
-               case IEEE80211_RADIOTAP_ANTENNA:
-                       /*
-                        * radiotap uses 0 for 1st ant, mac80211 is 1 for
-                        * 1st ant
-                        */
-                       control->antenna_sel_tx = (*iterator.this_arg) + 1;
-                       break;
-
-               case IEEE80211_RADIOTAP_DBM_TX_POWER:
-                       control->power_level = *iterator.this_arg;
-                       break;
-
-               case IEEE80211_RADIOTAP_FLAGS:
-                       if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
-                               /*
-                                * this indicates that the skb we have been
-                                * handed has the 32-bit FCS CRC at the end...
-                                * we should react to that by snipping it off
-                                * because it will be recomputed and added
-                                * on transmission
-                                */
-                               if (skb->len < (iterator.max_length + FCS_LEN))
-                                       return TXRX_DROP;
-
-                               skb_trim(skb, skb->len - FCS_LEN);
-                       }
-                       break;
-
-               default:
-                       break;
-               }
-       }
-
-       if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
-               return TXRX_DROP;
-
-       /*
-        * remove the radiotap header
-        * iterator->max_length was sanity-checked against
-        * skb->len by iterator init
-        */
-       skb_pull(skb, iterator.max_length);
-
-       return TXRX_CONTINUE;
-}
-
-
-static ieee80211_txrx_result inline
-__ieee80211_tx_prepare(struct ieee80211_txrx_data *tx,
-                      struct sk_buff *skb,
-                      struct net_device *dev,
-                      struct ieee80211_tx_control *control)
-{
-       struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
-       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
-       struct ieee80211_sub_if_data *sdata;
-       ieee80211_txrx_result res = TXRX_CONTINUE;
-
-       int hdrlen;
-
-       memset(tx, 0, sizeof(*tx));
-       tx->skb = skb;
-       tx->dev = dev; /* use original interface */
-       tx->local = local;
-       tx->sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-       tx->sta = sta_info_get(local, hdr->addr1);
-       tx->fc = le16_to_cpu(hdr->frame_control);
-
-       /*
-        * set defaults for things that can be set by
-        * injected radiotap headers
-        */
-       control->power_level = local->hw.conf.power_level;
-       control->antenna_sel_tx = local->hw.conf.antenna_sel_tx;
-       if (local->sta_antenna_sel != STA_ANTENNA_SEL_AUTO && tx->sta)
-               control->antenna_sel_tx = tx->sta->antenna_sel_tx;
-
-       /* process and remove the injection radiotap header */
-       sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-       if (unlikely(sdata->type == IEEE80211_IF_TYPE_MNTR)) {
-               if (__ieee80211_parse_tx_radiotap(tx, skb, control) ==
-                                                               TXRX_DROP) {
-                       return TXRX_DROP;
-               }
-               /*
-                * we removed the radiotap header after this point,
-                * we filled control with what we could use
-                * set to the actual ieee header now
-                */
-               hdr = (struct ieee80211_hdr *) skb->data;
-               res = TXRX_QUEUED; /* indication it was monitor packet */
-       }
-
-       tx->u.tx.control = control;
-       tx->u.tx.unicast = !is_multicast_ether_addr(hdr->addr1);
-       if (is_multicast_ether_addr(hdr->addr1))
-               control->flags |= IEEE80211_TXCTL_NO_ACK;
-       else
-               control->flags &= ~IEEE80211_TXCTL_NO_ACK;
-       tx->fragmented = local->fragmentation_threshold <
-               IEEE80211_MAX_FRAG_THRESHOLD && tx->u.tx.unicast &&
-               skb->len + FCS_LEN > local->fragmentation_threshold &&
-               (!local->ops->set_frag_threshold);
-       if (!tx->sta)
-               control->flags |= IEEE80211_TXCTL_CLEAR_DST_MASK;
-       else if (tx->sta->clear_dst_mask) {
-               control->flags |= IEEE80211_TXCTL_CLEAR_DST_MASK;
-               tx->sta->clear_dst_mask = 0;
-       }
-       hdrlen = ieee80211_get_hdrlen(tx->fc);
-       if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
-               u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
-               tx->ethertype = (pos[0] << 8) | pos[1];
-       }
-       control->flags |= IEEE80211_TXCTL_FIRST_FRAGMENT;
-
-       return res;
-}
-
-static int inline is_ieee80211_device(struct net_device *dev,
-                                     struct net_device *master)
-{
-       return (wdev_priv(dev->ieee80211_ptr) ==
-               wdev_priv(master->ieee80211_ptr));
-}
-
-/* Device in tx->dev has a reference added; use dev_put(tx->dev) when
- * finished with it. */
-static int inline ieee80211_tx_prepare(struct ieee80211_txrx_data *tx,
-                                      struct sk_buff *skb,
-                                      struct net_device *mdev,
-                                      struct ieee80211_tx_control *control)
-{
-       struct ieee80211_tx_packet_data *pkt_data;
-       struct net_device *dev;
-
-       pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
-       dev = dev_get_by_index(pkt_data->ifindex);
-       if (unlikely(dev && !is_ieee80211_device(dev, mdev))) {
-               dev_put(dev);
-               dev = NULL;
-       }
-       if (unlikely(!dev))
-               return -ENODEV;
-       __ieee80211_tx_prepare(tx, skb, dev, control);
-       return 0;
-}
-
-static inline int __ieee80211_queue_stopped(const struct ieee80211_local *local,
-                                           int queue)
-{
-       return test_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]);
-}
-
-static inline int __ieee80211_queue_pending(const struct ieee80211_local *local,
-                                           int queue)
-{
-       return test_bit(IEEE80211_LINK_STATE_PENDING, &local->state[queue]);
-}
-
-#define IEEE80211_TX_OK                0
-#define IEEE80211_TX_AGAIN     1
-#define IEEE80211_TX_FRAG_AGAIN        2
-
-static int __ieee80211_tx(struct ieee80211_local *local, struct sk_buff *skb,
-                         struct ieee80211_txrx_data *tx)
-{
-       struct ieee80211_tx_control *control = tx->u.tx.control;
-       int ret, i;
-
-       if (!ieee80211_qdisc_installed(local->mdev) &&
-           __ieee80211_queue_stopped(local, 0)) {
-               netif_stop_queue(local->mdev);
-               return IEEE80211_TX_AGAIN;
-       }
-       if (skb) {
-               ieee80211_dump_frame(local->mdev->name, "TX to low-level driver", skb);
-               ret = local->ops->tx(local_to_hw(local), skb, control);
-               if (ret)
-                       return IEEE80211_TX_AGAIN;
-               local->mdev->trans_start = jiffies;
-               ieee80211_led_tx(local, 1);
-       }
-       if (tx->u.tx.extra_frag) {
-               control->flags &= ~(IEEE80211_TXCTL_USE_RTS_CTS |
-                                   IEEE80211_TXCTL_USE_CTS_PROTECT |
-                                   IEEE80211_TXCTL_CLEAR_DST_MASK |
-                                   IEEE80211_TXCTL_FIRST_FRAGMENT);
-               for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
-                       if (!tx->u.tx.extra_frag[i])
-                               continue;
-                       if (__ieee80211_queue_stopped(local, control->queue))
-                               return IEEE80211_TX_FRAG_AGAIN;
-                       if (i == tx->u.tx.num_extra_frag) {
-                               control->tx_rate = tx->u.tx.last_frag_hwrate;
-                               control->rate = tx->u.tx.last_frag_rate;
-                               if (tx->u.tx.probe_last_frag)
-                                       control->flags |=
-                                               IEEE80211_TXCTL_RATE_CTRL_PROBE;
-                               else
-                                       control->flags &=
-                                               ~IEEE80211_TXCTL_RATE_CTRL_PROBE;
-                       }
-
-                       ieee80211_dump_frame(local->mdev->name,
-                                            "TX to low-level driver",
-                                            tx->u.tx.extra_frag[i]);
-                       ret = local->ops->tx(local_to_hw(local),
-                                           tx->u.tx.extra_frag[i],
-                                           control);
-                       if (ret)
-                               return IEEE80211_TX_FRAG_AGAIN;
-                       local->mdev->trans_start = jiffies;
-                       ieee80211_led_tx(local, 1);
-                       tx->u.tx.extra_frag[i] = NULL;
-               }
-               kfree(tx->u.tx.extra_frag);
-               tx->u.tx.extra_frag = NULL;
-       }
-       return IEEE80211_TX_OK;
-}
-
-static int ieee80211_tx(struct net_device *dev, struct sk_buff *skb,
-                       struct ieee80211_tx_control *control, int mgmt)
-{
-       struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
-       struct sta_info *sta;
-       ieee80211_tx_handler *handler;
-       struct ieee80211_txrx_data tx;
-       ieee80211_txrx_result res = TXRX_DROP, res_prepare;
-       int ret, i;
-
-       WARN_ON(__ieee80211_queue_pending(local, control->queue));
-
-       if (unlikely(skb->len < 10)) {
-               dev_kfree_skb(skb);
-               return 0;
-       }
-
-       res_prepare = __ieee80211_tx_prepare(&tx, skb, dev, control);
-
-       if (res_prepare == TXRX_DROP) {
-               dev_kfree_skb(skb);
-               return 0;
-       }
-
-       sta = tx.sta;
-       tx.u.tx.mgmt_interface = mgmt;
-       tx.u.tx.mode = local->hw.conf.mode;
-
-       if (res_prepare == TXRX_QUEUED) { /* if it was an injected packet */
-               res = TXRX_CONTINUE;
-       } else {
-               for (handler = local->tx_handlers; *handler != NULL;
-                    handler++) {
-                       res = (*handler)(&tx);
-                       if (res != TXRX_CONTINUE)
-                               break;
-               }
-       }
-
-       skb = tx.skb; /* handlers are allowed to change skb */
-
-       if (sta)
-               sta_info_put(sta);
-
-       if (unlikely(res == TXRX_DROP)) {
-               I802_DEBUG_INC(local->tx_handlers_drop);
-               goto drop;
-       }
-
-       if (unlikely(res == TXRX_QUEUED)) {
-               I802_DEBUG_INC(local->tx_handlers_queued);
-               return 0;
-       }
-
-       if (tx.u.tx.extra_frag) {
-               for (i = 0; i < tx.u.tx.num_extra_frag; i++) {
-                       int next_len, dur;
-                       struct ieee80211_hdr *hdr =
-                               (struct ieee80211_hdr *)
-                               tx.u.tx.extra_frag[i]->data;
-
-                       if (i + 1 < tx.u.tx.num_extra_frag) {
-                               next_len = tx.u.tx.extra_frag[i + 1]->len;
-                       } else {
-                               next_len = 0;
-                               tx.u.tx.rate = tx.u.tx.last_frag_rate;
-                               tx.u.tx.last_frag_hwrate = tx.u.tx.rate->val;
-                       }
-                       dur = ieee80211_duration(&tx, 0, next_len);
-                       hdr->duration_id = cpu_to_le16(dur);
-               }
-       }
-
-retry:
-       ret = __ieee80211_tx(local, skb, &tx);
-       if (ret) {
-               struct ieee80211_tx_stored_packet *store =
-                       &local->pending_packet[control->queue];
-
-               if (ret == IEEE80211_TX_FRAG_AGAIN)
-                       skb = NULL;
-               set_bit(IEEE80211_LINK_STATE_PENDING,
-                       &local->state[control->queue]);
-               smp_mb();
-               /* When the driver gets out of buffers during sending of
-                * fragments and calls ieee80211_stop_queue, there is
-                * a small window between IEEE80211_LINK_STATE_XOFF and
-                * IEEE80211_LINK_STATE_PENDING flags are set. If a buffer
-                * gets available in that window (i.e. driver calls
-                * ieee80211_wake_queue), we would end up with ieee80211_tx
-                * called with IEEE80211_LINK_STATE_PENDING. Prevent this by
-                * continuing transmitting here when that situation is
-                * possible to have happened. */
-               if (!__ieee80211_queue_stopped(local, control->queue)) {
-                       clear_bit(IEEE80211_LINK_STATE_PENDING,
-                                 &local->state[control->queue]);
-                       goto retry;
-               }
-               memcpy(&store->control, control,
-                      sizeof(struct ieee80211_tx_control));
-               store->skb = skb;
-               store->extra_frag = tx.u.tx.extra_frag;
-               store->num_extra_frag = tx.u.tx.num_extra_frag;
-               store->last_frag_hwrate = tx.u.tx.last_frag_hwrate;
-               store->last_frag_rate = tx.u.tx.last_frag_rate;
-               store->last_frag_rate_ctrl_probe = tx.u.tx.probe_last_frag;
-       }
-       return 0;
-
- drop:
-       if (skb)
-               dev_kfree_skb(skb);
-       for (i = 0; i < tx.u.tx.num_extra_frag; i++)
-               if (tx.u.tx.extra_frag[i])
-                       dev_kfree_skb(tx.u.tx.extra_frag[i]);
-       kfree(tx.u.tx.extra_frag);
-       return 0;
-}
-
-static void ieee80211_tx_pending(unsigned long data)
-{
-       struct ieee80211_local *local = (struct ieee80211_local *)data;
-       struct net_device *dev = local->mdev;
-       struct ieee80211_tx_stored_packet *store;
-       struct ieee80211_txrx_data tx;
-       int i, ret, reschedule = 0;
-
-       netif_tx_lock_bh(dev);
-       for (i = 0; i < local->hw.queues; i++) {
-               if (__ieee80211_queue_stopped(local, i))
-                       continue;
-               if (!__ieee80211_queue_pending(local, i)) {
-                       reschedule = 1;
-                       continue;
-               }
-               store = &local->pending_packet[i];
-               tx.u.tx.control = &store->control;
-               tx.u.tx.extra_frag = store->extra_frag;
-               tx.u.tx.num_extra_frag = store->num_extra_frag;
-               tx.u.tx.last_frag_hwrate = store->last_frag_hwrate;
-               tx.u.tx.last_frag_rate = store->last_frag_rate;
-               tx.u.tx.probe_last_frag = store->last_frag_rate_ctrl_probe;
-               ret = __ieee80211_tx(local, store->skb, &tx);
-               if (ret) {
-                       if (ret == IEEE80211_TX_FRAG_AGAIN)
-                               store->skb = NULL;
-               } else {
-                       clear_bit(IEEE80211_LINK_STATE_PENDING,
-                                 &local->state[i]);
-                       reschedule = 1;
-               }
-       }
-       netif_tx_unlock_bh(dev);
-       if (reschedule) {
-               if (!ieee80211_qdisc_installed(dev)) {
-                       if (!__ieee80211_queue_stopped(local, 0))
-                               netif_wake_queue(dev);
-               } else
-                       netif_schedule(dev);
-       }
-}
-
-static void ieee80211_clear_tx_pending(struct ieee80211_local *local)
-{
-       int i, j;
-       struct ieee80211_tx_stored_packet *store;
-
-       for (i = 0; i < local->hw.queues; i++) {
-               if (!__ieee80211_queue_pending(local, i))
-                       continue;
-               store = &local->pending_packet[i];
-               kfree_skb(store->skb);
-               for (j = 0; j < store->num_extra_frag; j++)
-                       kfree_skb(store->extra_frag[j]);
-               kfree(store->extra_frag);
-               clear_bit(IEEE80211_LINK_STATE_PENDING, &local->state[i]);
-       }
-}
-
-static int ieee80211_master_start_xmit(struct sk_buff *skb,
-                                      struct net_device *dev)
-{
-       struct ieee80211_tx_control control;
-       struct ieee80211_tx_packet_data *pkt_data;
-       struct net_device *odev = NULL;
-       struct ieee80211_sub_if_data *osdata;
-       int headroom;
-       int ret;
-
-       /*
-        * copy control out of the skb so other people can use skb->cb
-        */
-       pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
-       memset(&control, 0, sizeof(struct ieee80211_tx_control));
-
-       if (pkt_data->ifindex)
-               odev = dev_get_by_index(pkt_data->ifindex);
-       if (unlikely(odev && !is_ieee80211_device(odev, dev))) {
-               dev_put(odev);
-               odev = NULL;
-       }
-       if (unlikely(!odev)) {
-#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
-               printk(KERN_DEBUG "%s: Discarded packet with nonexistent "
-                      "originating device\n", dev->name);
-#endif
-               dev_kfree_skb(skb);
-               return 0;
-       }
-       osdata = IEEE80211_DEV_TO_SUB_IF(odev);
-
-       headroom = osdata->local->tx_headroom + IEEE80211_ENCRYPT_HEADROOM;
-       if (skb_headroom(skb) < headroom) {
-               if (pskb_expand_head(skb, headroom, 0, GFP_ATOMIC)) {
-                       dev_kfree_skb(skb);
-                       dev_put(odev);
-                       return 0;
-               }
-       }
-
-       control.ifindex = odev->ifindex;
-       control.type = osdata->type;
-       if (pkt_data->req_tx_status)
-               control.flags |= IEEE80211_TXCTL_REQ_TX_STATUS;
-       if (pkt_data->do_not_encrypt)
-               control.flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
-       if (pkt_data->requeue)
-               control.flags |= IEEE80211_TXCTL_REQUEUE;
-       control.queue = pkt_data->queue;
-
-       ret = ieee80211_tx(odev, skb, &control,
-                          control.type == IEEE80211_IF_TYPE_MGMT);
-       dev_put(odev);
-
-       return ret;
-}
-
-
-int ieee80211_monitor_start_xmit(struct sk_buff *skb,
-                                struct net_device *dev)
-{
-       struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
-       struct ieee80211_tx_packet_data *pkt_data;
-       struct ieee80211_radiotap_header *prthdr =
-               (struct ieee80211_radiotap_header *)skb->data;
-       u16 len;
-
-       /*
-        * there must be a radiotap header at the
-        * start in this case
-        */
-       if (unlikely(prthdr->it_version)) {
-               /* only version 0 is supported */
-               dev_kfree_skb(skb);
-               return NETDEV_TX_OK;
-       }
-
-       skb->dev = local->mdev;
-
-       pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
-       memset(pkt_data, 0, sizeof(*pkt_data));
-       pkt_data->ifindex = dev->ifindex;
-       pkt_data->mgmt_iface = 0;
-       pkt_data->do_not_encrypt = 1;
-
-       /* above needed because we set skb device to master */
-
-       /*
-        * fix up the pointers accounting for the radiotap
-        * header still being in there.  We are being given
-        * a precooked IEEE80211 header so no need for
-        * normal processing
-        */
-       len = le16_to_cpu(get_unaligned(&prthdr->it_len));
-       skb_set_mac_header(skb, len);
-       skb_set_network_header(skb, len + sizeof(struct ieee80211_hdr));
-       skb_set_transport_header(skb, len + sizeof(struct ieee80211_hdr));
-
-       /*
-        * pass the radiotap header up to
-        * the next stage intact
-        */
-       dev_queue_xmit(skb);
-
-       return NETDEV_TX_OK;
-}
-
-
-/**
- * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
- * subinterfaces (wlan#, WDS, and VLAN interfaces)
- * @skb: packet to be sent
- * @dev: incoming interface
- *
- * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
- * not be freed, and caller is responsible for either retrying later or freeing
- * skb).
- *
- * This function takes in an Ethernet header and encapsulates it with suitable
- * IEEE 802.11 header based on which interface the packet is coming in. The
- * encapsulated packet will then be passed to master interface, wlan#.11, for
- * transmission (through low-level driver).
- */
-int ieee80211_subif_start_xmit(struct sk_buff *skb,
-                              struct net_device *dev)
-{
-       struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
-       struct ieee80211_tx_packet_data *pkt_data;
-       struct ieee80211_sub_if_data *sdata;
-       int ret = 1, head_need;
-       u16 ethertype, hdrlen, fc;
-       struct ieee80211_hdr hdr;
-       const u8 *encaps_data;
-       int encaps_len, skip_header_bytes;
-       int nh_pos, h_pos, no_encrypt = 0;
-       struct sta_info *sta;
-
-       sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-       if (unlikely(skb->len < ETH_HLEN)) {
-               printk(KERN_DEBUG "%s: short skb (len=%d)\n",
-                      dev->name, skb->len);
-               ret = 0;
-               goto fail;
-       }
-
-       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];
-       /* TODO: handling for 802.1x authorized/unauthorized port */
-       fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA;
-
-       if (likely(sdata->type == IEEE80211_IF_TYPE_AP ||
-                  sdata->type == IEEE80211_IF_TYPE_VLAN)) {
-               fc |= IEEE80211_FCTL_FROMDS;
-               /* DA BSSID SA */
-               memcpy(hdr.addr1, skb->data, ETH_ALEN);
-               memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
-               memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
-               hdrlen = 24;
-       } else if (sdata->type == IEEE80211_IF_TYPE_WDS) {
-               fc |= IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS;
-               /* RA TA DA SA */
-               memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
-               memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
-               memcpy(hdr.addr3, skb->data, ETH_ALEN);
-               memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
-               hdrlen = 30;
-       } else if (sdata->type == IEEE80211_IF_TYPE_STA) {
-               fc |= IEEE80211_FCTL_TODS;
-               /* BSSID SA DA */
-               memcpy(hdr.addr1, sdata->u.sta.bssid, ETH_ALEN);
-               memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
-               memcpy(hdr.addr3, skb->data, ETH_ALEN);
-               hdrlen = 24;
-       } else if (sdata->type == IEEE80211_IF_TYPE_IBSS) {
-               /* DA SA BSSID */
-               memcpy(hdr.addr1, skb->data, ETH_ALEN);
-               memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
-               memcpy(hdr.addr3, sdata->u.sta.bssid, ETH_ALEN);
-               hdrlen = 24;
-       } else {
-               ret = 0;
-               goto fail;
-       }
-
-       /* receiver is QoS enabled, use a QoS type frame */
-       sta = sta_info_get(local, hdr.addr1);
-       if (sta) {
-               if (sta->flags & WLAN_STA_WME) {
-                       fc |= IEEE80211_STYPE_QOS_DATA;
-                       hdrlen += 2;
-               }
-               sta_info_put(sta);
-       }
-
-       hdr.frame_control = cpu_to_le16(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 >= 0x600) {
-               encaps_data = rfc1042_header;
-               encaps_len = sizeof(rfc1042_header);
-               skip_header_bytes -= 2;
-       } else {
-               encaps_data = NULL;
-               encaps_len = 0;
+                       return NULL;
        }
 
-       skb_pull(skb, skip_header_bytes);
-       nh_pos -= skip_header_bytes;
-       h_pos -= skip_header_bytes;
-
-       /* TODO: implement support for fragments so that there is no need to
-        * reallocate and copy payload; it might be enough to support one
-        * extra fragment that would be copied in the beginning of the frame
-        * data.. anyway, it would be nice to include this into skb structure
-        * somehow
-        *
-        * There are few options for this:
-        * use skb->cb as an extra space for 802.11 header
-        * allocate new buffer if not enough headroom
-        * make sure that there is enough headroom in every skb by increasing
-        * build in headroom in __dev_alloc_skb() (linux/skbuff.h) and
-        * alloc_skb() (net/core/skbuff.c)
-        */
-       head_need = hdrlen + encaps_len + local->tx_headroom;
-       head_need -= skb_headroom(skb);
-
-       /* We are going to modify skb data, so make a copy of it if happens to
-        * be cloned. This could happen, e.g., with Linux bridge code passing
-        * us broadcast frames. */
+       return NULL;
+}
 
-       if (head_need > 0 || skb_cloned(skb)) {
-#if 0
-               printk(KERN_DEBUG "%s: need to reallocate buffer for %d bytes "
-                      "of headroom\n", dev->name, head_need);
-#endif
+int ieee80211_get_hdrlen(u16 fc)
+{
+       int hdrlen = 24;
 
-               if (skb_cloned(skb))
-                       I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
+       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
-                       I802_DEBUG_INC(local->tx_expand_skb_head);
-               /* Since we have to reallocate the buffer, make sure that there
-                * is enough room for possible WEP IV/ICV and TKIP (8 bytes
-                * before payload and 12 after). */
-               if (pskb_expand_head(skb, (head_need > 0 ? head_need + 8 : 8),
-                                    12, GFP_ATOMIC)) {
-                       printk(KERN_DEBUG "%s: failed to reallocate TX buffer"
-                              "\n", dev->name);
-                       goto fail;
-               }
-       }
-
-       if (encaps_data) {
-               memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
-               nh_pos += encaps_len;
-               h_pos += encaps_len;
+                       hdrlen = 16;
+               break;
        }
-       memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
-       nh_pos += hdrlen;
-       h_pos += hdrlen;
-
-       pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
-       memset(pkt_data, 0, sizeof(struct ieee80211_tx_packet_data));
-       pkt_data->ifindex = dev->ifindex;
-       pkt_data->mgmt_iface = (sdata->type == IEEE80211_IF_TYPE_MGMT);
-       pkt_data->do_not_encrypt = no_encrypt;
-
-       skb->dev = local->mdev;
-       sdata->stats.tx_packets++;
-       sdata->stats.tx_bytes += skb->len;
-
-       /* 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_set_mac_header(skb, 0);
-       skb_set_network_header(skb, nh_pos);
-       skb_set_transport_header(skb, h_pos);
-
-       dev->trans_start = jiffies;
-       dev_queue_xmit(skb);
 
-       return 0;
+       return hdrlen;
+}
+EXPORT_SYMBOL(ieee80211_get_hdrlen);
 
- fail:
-       if (!ret)
-               dev_kfree_skb(skb);
+int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
+{
+       const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *) skb->data;
+       int hdrlen;
 
-       return ret;
+       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);
 
 
-/*
- * This is the transmit routine for the 802.11 type interfaces
- * called by upper layers of the linux networking
- * stack when it has a frame to transmit
- */
-static int
-ieee80211_mgmt_start_xmit(struct sk_buff *skb, struct net_device *dev)
+int ieee80211_is_eapol(const struct sk_buff *skb)
 {
-       struct ieee80211_sub_if_data *sdata;
-       struct ieee80211_tx_packet_data *pkt_data;
-       struct ieee80211_hdr *hdr;
+       const struct ieee80211_hdr *hdr;
        u16 fc;
+       int hdrlen;
 
-       sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-
-       if (skb->len < 10) {
-               dev_kfree_skb(skb);
+       if (unlikely(skb->len < 10))
                return 0;
-       }
-
-       if (skb_headroom(skb) < sdata->local->tx_headroom) {
-               if (pskb_expand_head(skb, sdata->local->tx_headroom,
-                                    0, GFP_ATOMIC)) {
-                       dev_kfree_skb(skb);
-                       return 0;
-               }
-       }
 
-       hdr = (struct ieee80211_hdr *) skb->data;
+       hdr = (const struct ieee80211_hdr *) skb->data;
        fc = le16_to_cpu(hdr->frame_control);
 
-       pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
-       memset(pkt_data, 0, sizeof(struct ieee80211_tx_packet_data));
-       pkt_data->ifindex = sdata->dev->ifindex;
-       pkt_data->mgmt_iface = (sdata->type == IEEE80211_IF_TYPE_MGMT);
-
-       skb->priority = 20; /* use hardcoded priority for mgmt TX queue */
-       skb->dev = sdata->local->mdev;
-
-       /*
-        * We're using the protocol field of the the frame control header
-        * to request TX callback for hostapd. BIT(1) is checked.
-        */
-       if ((fc & BIT(1)) == BIT(1)) {
-               pkt_data->req_tx_status = 1;
-               fc &= ~BIT(1);
-               hdr->frame_control = cpu_to_le16(fc);
-       }
-
-       pkt_data->do_not_encrypt = !(fc & IEEE80211_FCTL_PROTECTED);
+       if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
+               return 0;
 
-       sdata->stats.tx_packets++;
-       sdata->stats.tx_bytes += skb->len;
+       hdrlen = ieee80211_get_hdrlen(fc);
 
-       dev_queue_xmit(skb);
+       if (unlikely(skb->len >= hdrlen + sizeof(eapol_header) &&
+                    memcmp(skb->data + hdrlen, eapol_header,
+                           sizeof(eapol_header)) == 0))
+               return 1;
 
        return 0;
 }
 
 
-static void ieee80211_beacon_add_tim(struct ieee80211_local *local,
-                                    struct ieee80211_if_ap *bss,
-                                    struct sk_buff *skb)
+void ieee80211_tx_set_iswep(struct ieee80211_txrx_data *tx)
 {
-       u8 *pos, *tim;
-       int aid0 = 0;
-       int i, have_bits = 0, n1, n2;
+       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
 
-       /* Generate bitmap for TIM only if there are any STAs in power save
-        * mode. */
-       spin_lock_bh(&local->sta_lock);
-       if (atomic_read(&bss->num_sta_ps) > 0)
-               /* in the hope that this is faster than
-                * checking byte-for-byte */
-               have_bits = !bitmap_empty((unsigned long*)bss->tim,
-                                         IEEE80211_MAX_AID+1);
-
-       if (bss->dtim_count == 0)
-               bss->dtim_count = bss->dtim_period - 1;
-       else
-               bss->dtim_count--;
-
-       tim = pos = (u8 *) skb_put(skb, 6);
-       *pos++ = WLAN_EID_TIM;
-       *pos++ = 4;
-       *pos++ = bss->dtim_count;
-       *pos++ = bss->dtim_period;
-
-       if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
-               aid0 = 1;
-
-       if (have_bits) {
-               /* Find largest even number N1 so that bits numbered 1 through
-                * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
-                * (N2 + 1) x 8 through 2007 are 0. */
-               n1 = 0;
-               for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
-                       if (bss->tim[i]) {
-                               n1 = i & 0xfe;
-                               break;
-                       }
-               }
-               n2 = n1;
-               for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
-                       if (bss->tim[i]) {
-                               n2 = i;
-                               break;
-                       }
+       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);
                }
-
-               /* Bitmap control */
-               *pos++ = n1 | aid0;
-               /* Part Virt Bitmap */
-               memcpy(pos, bss->tim + n1, n2 - n1 + 1);
-
-               tim[1] = n2 - n1 + 4;
-               skb_put(skb, n2 - n1);
-       } else {
-               *pos++ = aid0; /* Bitmap control */
-               *pos++ = 0; /* Part Virt Bitmap */
        }
-       spin_unlock_bh(&local->sta_lock);
 }
 
 
-struct sk_buff * ieee80211_beacon_get(struct ieee80211_hw *hw, int if_id,
-                                     struct ieee80211_tx_control *control)
+static int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
+                                   int rate, int erp, int short_preamble)
 {
-       struct ieee80211_local *local = hw_to_local(hw);
-       struct sk_buff *skb;
-       struct net_device *bdev;
-       struct ieee80211_sub_if_data *sdata = NULL;
-       struct ieee80211_if_ap *ap = NULL;
-       struct ieee80211_rate *rate;
-       struct rate_control_extra extra;
-       u8 *b_head, *b_tail;
-       int bh_len, bt_len;
-
-       bdev = dev_get_by_index(if_id);
-       if (bdev) {
-               sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
-               ap = &sdata->u.ap;
-               dev_put(bdev);
-       }
-
-       if (!ap || sdata->type != IEEE80211_IF_TYPE_AP ||
-           !ap->beacon_head) {
-#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
-               if (net_ratelimit())
-                       printk(KERN_DEBUG "no beacon data avail for idx=%d "
-                              "(%s)\n", if_id, bdev ? bdev->name : "N/A");
-#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
-               return NULL;
-       }
-
-       /* Assume we are generating the normal beacon locally */
-       b_head = ap->beacon_head;
-       b_tail = ap->beacon_tail;
-       bh_len = ap->beacon_head_len;
-       bt_len = ap->beacon_tail_len;
-
-       skb = dev_alloc_skb(local->tx_headroom +
-               bh_len + bt_len + 256 /* maximum TIM len */);
-       if (!skb)
-               return NULL;
-
-       skb_reserve(skb, local->tx_headroom);
-       memcpy(skb_put(skb, bh_len), b_head, bh_len);
+       int dur;
 
-       ieee80211_include_sequence(sdata, (struct ieee80211_hdr *)skb->data);
+       /* 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.
+        */
 
-       ieee80211_beacon_add_tim(local, ap, skb);
+       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);
 
-       if (b_tail) {
-               memcpy(skb_put(skb, bt_len), b_tail, bt_len);
+               dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate);
        }
 
-       if (control) {
-               memset(&extra, 0, sizeof(extra));
-               extra.mode = local->oper_hw_mode;
+       return dur;
+}
 
-               rate = rate_control_get_rate(local, local->mdev, skb, &extra);
-               if (!rate) {
-                       if (net_ratelimit()) {
-                               printk(KERN_DEBUG "%s: ieee80211_beacon_get: no rate "
-                                      "found\n", local->mdev->name);
-                       }
-                       dev_kfree_skb(skb);
-                       return NULL;
-               }
 
-               control->tx_rate = (local->short_preamble &&
-                                   (rate->flags & IEEE80211_RATE_PREAMBLE2)) ?
-                       rate->val2 : rate->val;
-               control->antenna_sel_tx = local->hw.conf.antenna_sel_tx;
-               control->power_level = local->hw.conf.power_level;
-               control->flags |= IEEE80211_TXCTL_NO_ACK;
-               control->retry_limit = 1;
-               control->flags |= IEEE80211_TXCTL_CLEAR_DST_MASK;
-       }
+/* 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);
 
-       ap->num_beacons++;
-       return skb;
+       return cpu_to_le16(dur);
 }
-EXPORT_SYMBOL(ieee80211_beacon_get);
+EXPORT_SYMBOL(ieee80211_generic_frame_duration);
+
 
 __le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
                              size_t frame_len,
@@ -2168,110 +505,6 @@ __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
 }
 EXPORT_SYMBOL(ieee80211_ctstoself_duration);
 
-void ieee80211_rts_get(struct ieee80211_hw *hw,
-                      const void *frame, size_t frame_len,
-                      const struct ieee80211_tx_control *frame_txctl,
-                      struct ieee80211_rts *rts)
-{
-       const struct ieee80211_hdr *hdr = frame;
-       u16 fctl;
-
-       fctl = IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS;
-       rts->frame_control = cpu_to_le16(fctl);
-       rts->duration = ieee80211_rts_duration(hw, frame_len, frame_txctl);
-       memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
-       memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
-}
-EXPORT_SYMBOL(ieee80211_rts_get);
-
-void ieee80211_ctstoself_get(struct ieee80211_hw *hw,
-                            const void *frame, size_t frame_len,
-                            const struct ieee80211_tx_control *frame_txctl,
-                            struct ieee80211_cts *cts)
-{
-       const struct ieee80211_hdr *hdr = frame;
-       u16 fctl;
-
-       fctl = IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS;
-       cts->frame_control = cpu_to_le16(fctl);
-       cts->duration = ieee80211_ctstoself_duration(hw, frame_len, frame_txctl);
-       memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
-}
-EXPORT_SYMBOL(ieee80211_ctstoself_get);
-
-struct sk_buff *
-ieee80211_get_buffered_bc(struct ieee80211_hw *hw, int if_id,
-                         struct ieee80211_tx_control *control)
-{
-       struct ieee80211_local *local = hw_to_local(hw);
-       struct sk_buff *skb;
-       struct sta_info *sta;
-       ieee80211_tx_handler *handler;
-       struct ieee80211_txrx_data tx;
-       ieee80211_txrx_result res = TXRX_DROP;
-       struct net_device *bdev;
-       struct ieee80211_sub_if_data *sdata;
-       struct ieee80211_if_ap *bss = NULL;
-
-       bdev = dev_get_by_index(if_id);
-       if (bdev) {
-               sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
-               bss = &sdata->u.ap;
-               dev_put(bdev);
-       }
-       if (!bss || sdata->type != IEEE80211_IF_TYPE_AP || !bss->beacon_head)
-               return NULL;
-
-       if (bss->dtim_count != 0)
-               return NULL; /* send buffered bc/mc only after DTIM beacon */
-       memset(control, 0, sizeof(*control));
-       while (1) {
-               skb = skb_dequeue(&bss->ps_bc_buf);
-               if (!skb)
-                       return NULL;
-               local->total_ps_buffered--;
-
-               if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
-                       struct ieee80211_hdr *hdr =
-                               (struct ieee80211_hdr *) skb->data;
-                       /* more buffered multicast/broadcast frames ==> set
-                        * MoreData flag in IEEE 802.11 header to inform PS
-                        * STAs */
-                       hdr->frame_control |=
-                               cpu_to_le16(IEEE80211_FCTL_MOREDATA);
-               }
-
-               if (ieee80211_tx_prepare(&tx, skb, local->mdev, control) == 0)
-                       break;
-               dev_kfree_skb_any(skb);
-       }
-       sta = tx.sta;
-       tx.u.tx.ps_buffered = 1;
-
-       for (handler = local->tx_handlers; *handler != NULL; handler++) {
-               res = (*handler)(&tx);
-               if (res == TXRX_DROP || res == TXRX_QUEUED)
-                       break;
-       }
-       dev_put(tx.dev);
-       skb = tx.skb; /* handlers are allowed to change skb */
-
-       if (res == TXRX_DROP) {
-               I802_DEBUG_INC(local->tx_handlers_drop);
-               dev_kfree_skb(skb);
-               skb = NULL;
-       } else if (res == TXRX_QUEUED) {
-               I802_DEBUG_INC(local->tx_handlers_queued);
-               skb = NULL;
-       }
-
-       if (sta)
-               sta_info_put(sta);
-
-       return skb;
-}
-EXPORT_SYMBOL(ieee80211_get_buffered_bc);
-
 static int __ieee80211_if_config(struct net_device *dev,
                                 struct sk_buff *beacon,
                                 struct ieee80211_tx_control *control)
@@ -2912,64 +1145,6 @@ int ieee80211_radar_status(struct ieee80211_hw *hw, int channel,
 EXPORT_SYMBOL(ieee80211_radar_status);
 
 
-static ieee80211_txrx_result
-ieee80211_tx_h_load_stats(struct ieee80211_txrx_data *tx)
-{
-       struct ieee80211_local *local = tx->local;
-       struct ieee80211_hw_mode *mode = tx->u.tx.mode;
-       struct sk_buff *skb = tx->skb;
-       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
-       u32 load = 0, hdrtime;
-
-       /* TODO: this could be part of tx_status handling, so that the number
-        * of retries would be known; TX rate should in that case be stored
-        * somewhere with the packet */
-
-       /* Estimate total channel use caused by this frame */
-
-       /* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
-        * 1 usec = 1/8 * (1080 / 10) = 13.5 */
-
-       if (mode->mode == MODE_IEEE80211A ||
-           mode->mode == MODE_ATHEROS_TURBO ||
-           mode->mode == MODE_ATHEROS_TURBOG ||
-           (mode->mode == MODE_IEEE80211G &&
-            tx->u.tx.rate->flags & IEEE80211_RATE_ERP))
-               hdrtime = CHAN_UTIL_HDR_SHORT;
-       else
-               hdrtime = CHAN_UTIL_HDR_LONG;
-
-       load = hdrtime;
-       if (!is_multicast_ether_addr(hdr->addr1))
-               load += hdrtime;
-
-       if (tx->u.tx.control->flags & IEEE80211_TXCTL_USE_RTS_CTS)
-               load += 2 * hdrtime;
-       else if (tx->u.tx.control->flags & IEEE80211_TXCTL_USE_CTS_PROTECT)
-               load += hdrtime;
-
-       load += skb->len * tx->u.tx.rate->rate_inv;
-
-       if (tx->u.tx.extra_frag) {
-               int i;
-               for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
-                       load += 2 * hdrtime;
-                       load += tx->u.tx.extra_frag[i]->len *
-                               tx->u.tx.rate->rate;
-               }
-       }
-
-       /* Divide channel_use by 8 to avoid wrapping around the counter */
-       load >>= CHAN_UTIL_SHIFT;
-       local->channel_use_raw += load;
-       if (tx->sta)
-               tx->sta->channel_use_raw += load;
-       tx->sdata->channel_use_raw += load;
-
-       return TXRX_CONTINUE;
-}
-
-
 static void ieee80211_stat_refresh(unsigned long data)
 {
        struct ieee80211_local *local = (struct ieee80211_local *) data;
@@ -3365,26 +1540,6 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb,
 }
 EXPORT_SYMBOL(ieee80211_tx_status);
 
-/* TODO: implement register/unregister functions for adding TX/RX handlers
- * into ordered list */
-
-static ieee80211_tx_handler ieee80211_tx_handlers[] =
-{
-       ieee80211_tx_h_check_assoc,
-       ieee80211_tx_h_sequence,
-       ieee80211_tx_h_ps_buf,
-       ieee80211_tx_h_select_key,
-       ieee80211_tx_h_michael_mic_add,
-       ieee80211_tx_h_fragment,
-       ieee80211_tx_h_tkip_encrypt,
-       ieee80211_tx_h_ccmp_encrypt,
-       ieee80211_tx_h_wep_encrypt,
-       ieee80211_tx_h_rate_ctrl,
-       ieee80211_tx_h_misc,
-       ieee80211_tx_h_load_stats,
-       NULL
-};
-
 
 int ieee80211_if_update_wds(struct net_device *dev, u8 *remote_addr)
 {
index 35e2ce5..9d3401d 100644 (file)
@@ -731,8 +731,6 @@ void ieee80211_prepare_rates(struct ieee80211_local *local,
                             struct ieee80211_hw_mode *mode);
 void ieee80211_tx_set_iswep(struct ieee80211_txrx_data *tx);
 int ieee80211_if_update_wds(struct net_device *dev, u8 *remote_addr);
-int ieee80211_monitor_start_xmit(struct sk_buff *skb, struct net_device *dev);
-int ieee80211_subif_start_xmit(struct sk_buff *skb, struct net_device *dev);
 void ieee80211_if_setup(struct net_device *dev);
 void ieee80211_if_mgmt_setup(struct net_device *dev);
 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
@@ -746,8 +744,11 @@ void ieee80211_key_threshold_notify(struct net_device *dev,
 u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len);
 int ieee80211_is_eapol(const struct sk_buff *skb);
 
-extern const unsigned char rfc1042_header[];
-extern const unsigned char bridge_tunnel_header[];
+extern const unsigned char rfc1042_header[6];
+extern const unsigned char bridge_tunnel_header[6];
+
+int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
+                            int rate, int erp, int short_preamble);
 
 /* ieee80211_ioctl.c */
 extern const struct iw_handler_def ieee80211_iw_handler_def;
@@ -823,6 +824,15 @@ void ieee80211_set_default_regdomain(struct ieee80211_hw_mode *mode);
 extern ieee80211_rx_handler ieee80211_rx_pre_handlers[];
 extern ieee80211_rx_handler ieee80211_rx_handlers[];
 
+/* tx handling */
+extern ieee80211_tx_handler ieee80211_tx_handlers[];
+void ieee80211_clear_tx_pending(struct ieee80211_local *local);
+void ieee80211_tx_pending(unsigned long data);
+int ieee80211_master_start_xmit(struct sk_buff *skb, struct net_device *dev);
+int ieee80211_monitor_start_xmit(struct sk_buff *skb, struct net_device *dev);
+int ieee80211_subif_start_xmit(struct sk_buff *skb, struct net_device *dev);
+int ieee80211_mgmt_start_xmit(struct sk_buff *skb, struct net_device *dev);
+
 /* for wiphy privid */
 extern void *mac80211_wiphy_privid;
 
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
new file mode 100644 (file)
index 0000000..dc128b4
--- /dev/null
@@ -0,0 +1,1869 @@
+/*
+ * 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.
+ *
+ *
+ * Transmit and frame generation functions.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/skbuff.h>
+#include <linux/etherdevice.h>
+#include <linux/bitmap.h>
+#include <net/ieee80211_radiotap.h>
+#include <net/cfg80211.h>
+#include <net/mac80211.h>
+#include <asm/unaligned.h>
+
+#include "ieee80211_i.h"
+#include "ieee80211_led.h"
+#include "wep.h"
+#include "wpa.h"
+#include "wme.h"
+#include "ieee80211_rate.h"
+
+#define IEEE80211_TX_OK                0
+#define IEEE80211_TX_AGAIN     1
+#define IEEE80211_TX_FRAG_AGAIN        2
+
+/* misc utils */
+
+static inline void ieee80211_include_sequence(struct ieee80211_sub_if_data *sdata,
+                                             struct ieee80211_hdr *hdr)
+{
+       /* Set the sequence number for this frame. */
+       hdr->seq_ctrl = cpu_to_le16(sdata->sequence);
+
+       /* Increase the sequence number. */
+       sdata->sequence = (sdata->sequence + 0x10) & IEEE80211_SCTL_SEQ;
+}
+
+#ifdef CONFIG_MAC80211_LOWTX_FRAME_DUMP
+static void ieee80211_dump_frame(const char *ifname, const char *title,
+                                const struct sk_buff *skb)
+{
+       const struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+       u16 fc;
+       int hdrlen;
+
+       printk(KERN_DEBUG "%s: %s (len=%d)", ifname, title, skb->len);
+       if (skb->len < 4) {
+               printk("\n");
+               return;
+       }
+
+       fc = le16_to_cpu(hdr->frame_control);
+       hdrlen = ieee80211_get_hdrlen(fc);
+       if (hdrlen > skb->len)
+               hdrlen = skb->len;
+       if (hdrlen >= 4)
+               printk(" FC=0x%04x DUR=0x%04x",
+                      fc, le16_to_cpu(hdr->duration_id));
+       if (hdrlen >= 10)
+               printk(" A1=" MAC_FMT, MAC_ARG(hdr->addr1));
+       if (hdrlen >= 16)
+               printk(" A2=" MAC_FMT, MAC_ARG(hdr->addr2));
+       if (hdrlen >= 24)
+               printk(" A3=" MAC_FMT, MAC_ARG(hdr->addr3));
+       if (hdrlen >= 30)
+               printk(" A4=" MAC_FMT, MAC_ARG(hdr->addr4));
+       printk("\n");
+}
+#else /* CONFIG_MAC80211_LOWTX_FRAME_DUMP */
+static inline void ieee80211_dump_frame(const char *ifname, const char *title,
+                                       struct sk_buff *skb)
+{
+}
+#endif /* CONFIG_MAC80211_LOWTX_FRAME_DUMP */
+
+static u16 ieee80211_duration(struct ieee80211_txrx_data *tx, int group_addr,
+                             int next_frag_len)
+{
+       int rate, mrate, erp, dur, i;
+       struct ieee80211_rate *txrate = tx->u.tx.rate;
+       struct ieee80211_local *local = tx->local;
+       struct ieee80211_hw_mode *mode = tx->u.tx.mode;
+
+       erp = txrate->flags & IEEE80211_RATE_ERP;
+
+       /*
+        * data and mgmt (except PS Poll):
+        * - during CFP: 32768
+        * - during contention period:
+        *   if addr1 is group address: 0
+        *   if more fragments = 0 and addr1 is individual address: time to
+        *      transmit one ACK plus SIFS
+        *   if more fragments = 1 and addr1 is individual address: time to
+        *      transmit next fragment plus 2 x ACK plus 3 x SIFS
+        *
+        * IEEE 802.11, 9.6:
+        * - control response frame (CTS or ACK) shall be transmitted using the
+        *   same rate as the immediately previous frame in the frame exchange
+        *   sequence, if this rate belongs to the PHY mandatory rates, or else
+        *   at the highest possible rate belonging to the PHY rates in the
+        *   BSSBasicRateSet
+        */
+
+       if ((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL) {
+               /* TODO: These control frames are not currently sent by
+                * 80211.o, but should they be implemented, this function
+                * needs to be updated to support duration field calculation.
+                *
+                * RTS: time needed to transmit pending data/mgmt frame plus
+                *    one CTS frame plus one ACK frame plus 3 x SIFS
+                * CTS: duration of immediately previous RTS minus time
+                *    required to transmit CTS and its SIFS
+                * ACK: 0 if immediately previous directed data/mgmt had
+                *    more=0, with more=1 duration in ACK frame is duration
+                *    from previous frame minus time needed to transmit ACK
+                *    and its SIFS
+                * PS Poll: BIT(15) | BIT(14) | aid
+                */
+               return 0;
+       }
+
+       /* data/mgmt */
+       if (0 /* FIX: data/mgmt during CFP */)
+               return 32768;
+
+       if (group_addr) /* Group address as the destination - no ACK */
+               return 0;
+
+       /* Individual destination address:
+        * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
+        * CTS and ACK frames shall be transmitted using the highest rate in
+        * basic rate set that is less than or equal to the rate of the
+        * immediately previous frame and that is using the same modulation
+        * (CCK or OFDM). If no basic rate set matches with these requirements,
+        * the highest mandatory rate of the PHY that is less than or equal to
+        * the rate of the previous frame is used.
+        * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
+        */
+       rate = -1;
+       mrate = 10; /* use 1 Mbps if everything fails */
+       for (i = 0; i < mode->num_rates; i++) {
+               struct ieee80211_rate *r = &mode->rates[i];
+               if (r->rate > txrate->rate)
+                       break;
+
+               if (IEEE80211_RATE_MODULATION(txrate->flags) !=
+                   IEEE80211_RATE_MODULATION(r->flags))
+                       continue;
+
+               if (r->flags & IEEE80211_RATE_BASIC)
+                       rate = r->rate;
+               else if (r->flags & IEEE80211_RATE_MANDATORY)
+                       mrate = r->rate;
+       }
+       if (rate == -1) {
+               /* No matching basic rate found; use highest suitable mandatory
+                * PHY rate */
+               rate = mrate;
+       }
+
+       /* Time needed to transmit ACK
+        * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
+        * to closest integer */
+
+       dur = ieee80211_frame_duration(local, 10, rate, erp,
+                                      local->short_preamble);
+
+       if (next_frag_len) {
+               /* Frame is fragmented: duration increases with time needed to
+                * transmit next fragment plus ACK and 2 x SIFS. */
+               dur *= 2; /* ACK + SIFS */
+               /* next fragment */
+               dur += ieee80211_frame_duration(local, next_frag_len,
+                                               txrate->rate, erp,
+                                               local->short_preamble);
+       }
+
+       return dur;
+}
+
+static inline int __ieee80211_queue_stopped(const struct ieee80211_local *local,
+                                           int queue)
+{
+       return test_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]);
+}
+
+static inline int __ieee80211_queue_pending(const struct ieee80211_local *local,
+                                           int queue)
+{
+       return test_bit(IEEE80211_LINK_STATE_PENDING, &local->state[queue]);
+}
+
+static int inline is_ieee80211_device(struct net_device *dev,
+                                     struct net_device *master)
+{
+       return (wdev_priv(dev->ieee80211_ptr) ==
+               wdev_priv(master->ieee80211_ptr));
+}
+
+/* tx handlers */
+
+static ieee80211_txrx_result
+ieee80211_tx_h_check_assoc(struct ieee80211_txrx_data *tx)
+{
+#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
+       struct sk_buff *skb = tx->skb;
+       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
+       u32 sta_flags;
+
+       if (unlikely(tx->local->sta_scanning != 0) &&
+           ((tx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
+            (tx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PROBE_REQ))
+               return TXRX_DROP;
+
+       if (tx->u.tx.ps_buffered)
+               return TXRX_CONTINUE;
+
+       sta_flags = tx->sta ? tx->sta->flags : 0;
+
+       if (likely(tx->u.tx.unicast)) {
+               if (unlikely(!(sta_flags & WLAN_STA_ASSOC) &&
+                            tx->sdata->type != IEEE80211_IF_TYPE_IBSS &&
+                            (tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)) {
+#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
+                       printk(KERN_DEBUG "%s: dropped data frame to not "
+                              "associated station " MAC_FMT "\n",
+                              tx->dev->name, MAC_ARG(hdr->addr1));
+#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
+                       I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
+                       return TXRX_DROP;
+               }
+       } else {
+               if (unlikely((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
+                            tx->local->num_sta == 0 &&
+                            !tx->local->allow_broadcast_always &&
+                            tx->sdata->type != IEEE80211_IF_TYPE_IBSS)) {
+                       /*
+                        * No associated STAs - no need to send multicast
+                        * frames.
+                        */
+                       return TXRX_DROP;
+               }
+               return TXRX_CONTINUE;
+       }
+
+       if (unlikely(!tx->u.tx.mgmt_interface && tx->sdata->ieee802_1x &&
+                    !(sta_flags & WLAN_STA_AUTHORIZED))) {
+#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
+               printk(KERN_DEBUG "%s: dropped frame to " MAC_FMT
+                      " (unauthorized port)\n", tx->dev->name,
+                      MAC_ARG(hdr->addr1));
+#endif
+               I802_DEBUG_INC(tx->local->tx_handlers_drop_unauth_port);
+               return TXRX_DROP;
+       }
+
+       return TXRX_CONTINUE;
+}
+
+static ieee80211_txrx_result
+ieee80211_tx_h_sequence(struct ieee80211_txrx_data *tx)
+{
+       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
+
+       if (ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control)) >= 24)
+               ieee80211_include_sequence(tx->sdata, hdr);
+
+       return TXRX_CONTINUE;
+}
+
+/* This function is called whenever the AP is about to exceed the maximum limit
+ * of buffered frames for power saving STAs. This situation should not really
+ * happen often during normal operation, so dropping the oldest buffered packet
+ * from each queue should be OK to make some room for new frames. */
+static void purge_old_ps_buffers(struct ieee80211_local *local)
+{
+       int total = 0, purged = 0;
+       struct sk_buff *skb;
+       struct ieee80211_sub_if_data *sdata;
+       struct sta_info *sta;
+
+       read_lock(&local->sub_if_lock);
+       list_for_each_entry(sdata, &local->sub_if_list, list) {
+               struct ieee80211_if_ap *ap;
+               if (sdata->dev == local->mdev ||
+                   sdata->type != IEEE80211_IF_TYPE_AP)
+                       continue;
+               ap = &sdata->u.ap;
+               skb = skb_dequeue(&ap->ps_bc_buf);
+               if (skb) {
+                       purged++;
+                       dev_kfree_skb(skb);
+               }
+               total += skb_queue_len(&ap->ps_bc_buf);
+       }
+       read_unlock(&local->sub_if_lock);
+
+       spin_lock_bh(&local->sta_lock);
+       list_for_each_entry(sta, &local->sta_list, list) {
+               skb = skb_dequeue(&sta->ps_tx_buf);
+               if (skb) {
+                       purged++;
+                       dev_kfree_skb(skb);
+               }
+               total += skb_queue_len(&sta->ps_tx_buf);
+       }
+       spin_unlock_bh(&local->sta_lock);
+
+       local->total_ps_buffered = total;
+       printk(KERN_DEBUG "%s: PS buffers full - purged %d frames\n",
+              local->mdev->name, purged);
+}
+
+static inline ieee80211_txrx_result
+ieee80211_tx_h_multicast_ps_buf(struct ieee80211_txrx_data *tx)
+{
+       /* broadcast/multicast frame */
+       /* If any of the associated stations is in power save mode,
+        * the frame is buffered to be sent after DTIM beacon frame */
+       if ((tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING) &&
+           tx->sdata->type != IEEE80211_IF_TYPE_WDS &&
+           tx->sdata->bss && atomic_read(&tx->sdata->bss->num_sta_ps) &&
+           !(tx->fc & IEEE80211_FCTL_ORDER)) {
+               if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
+                       purge_old_ps_buffers(tx->local);
+               if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >=
+                   AP_MAX_BC_BUFFER) {
+                       if (net_ratelimit()) {
+                               printk(KERN_DEBUG "%s: BC TX buffer full - "
+                                      "dropping the oldest frame\n",
+                                      tx->dev->name);
+                       }
+                       dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
+               } else
+                       tx->local->total_ps_buffered++;
+               skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
+               return TXRX_QUEUED;
+       }
+
+       return TXRX_CONTINUE;
+}
+
+static inline ieee80211_txrx_result
+ieee80211_tx_h_unicast_ps_buf(struct ieee80211_txrx_data *tx)
+{
+       struct sta_info *sta = tx->sta;
+
+       if (unlikely(!sta ||
+                    ((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT &&
+                     (tx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PROBE_RESP)))
+               return TXRX_CONTINUE;
+
+       if (unlikely((sta->flags & WLAN_STA_PS) && !sta->pspoll)) {
+               struct ieee80211_tx_packet_data *pkt_data;
+#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
+               printk(KERN_DEBUG "STA " MAC_FMT " aid %d: PS buffer (entries "
+                      "before %d)\n",
+                      MAC_ARG(sta->addr), sta->aid,
+                      skb_queue_len(&sta->ps_tx_buf));
+#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
+               sta->flags |= WLAN_STA_TIM;
+               if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
+                       purge_old_ps_buffers(tx->local);
+               if (skb_queue_len(&sta->ps_tx_buf) >= STA_MAX_TX_BUFFER) {
+                       struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf);
+                       if (net_ratelimit()) {
+                               printk(KERN_DEBUG "%s: STA " MAC_FMT " TX "
+                                      "buffer full - dropping oldest frame\n",
+                                      tx->dev->name, MAC_ARG(sta->addr));
+                       }
+                       dev_kfree_skb(old);
+               } else
+                       tx->local->total_ps_buffered++;
+               /* Queue frame to be sent after STA sends an PS Poll frame */
+               if (skb_queue_empty(&sta->ps_tx_buf)) {
+                       if (tx->local->ops->set_tim)
+                               tx->local->ops->set_tim(local_to_hw(tx->local),
+                                                      sta->aid, 1);
+                       if (tx->sdata->bss)
+                               bss_tim_set(tx->local, tx->sdata->bss, sta->aid);
+               }
+               pkt_data = (struct ieee80211_tx_packet_data *)tx->skb->cb;
+               pkt_data->jiffies = jiffies;
+               skb_queue_tail(&sta->ps_tx_buf, tx->skb);
+               return TXRX_QUEUED;
+       }
+#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
+       else if (unlikely(sta->flags & WLAN_STA_PS)) {
+               printk(KERN_DEBUG "%s: STA " MAC_FMT " in PS mode, but pspoll "
+                      "set -> send frame\n", tx->dev->name,
+                      MAC_ARG(sta->addr));
+       }
+#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
+       sta->pspoll = 0;
+
+       return TXRX_CONTINUE;
+}
+
+
+static ieee80211_txrx_result
+ieee80211_tx_h_ps_buf(struct ieee80211_txrx_data *tx)
+{
+       if (unlikely(tx->u.tx.ps_buffered))
+               return TXRX_CONTINUE;
+
+       if (tx->u.tx.unicast)
+               return ieee80211_tx_h_unicast_ps_buf(tx);
+       else
+               return ieee80211_tx_h_multicast_ps_buf(tx);
+}
+
+
+
+
+static ieee80211_txrx_result
+ieee80211_tx_h_select_key(struct ieee80211_txrx_data *tx)
+{
+       if (tx->sta)
+               tx->u.tx.control->key_idx = tx->sta->key_idx_compression;
+       else
+               tx->u.tx.control->key_idx = HW_KEY_IDX_INVALID;
+
+       if (unlikely(tx->u.tx.control->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT))
+               tx->key = NULL;
+       else if (tx->sta && tx->sta->key)
+               tx->key = tx->sta->key;
+       else if (tx->sdata->default_key)
+               tx->key = tx->sdata->default_key;
+       else if (tx->sdata->drop_unencrypted &&
+                !(tx->sdata->eapol && ieee80211_is_eapol(tx->skb))) {
+               I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
+               return TXRX_DROP;
+       } else
+               tx->key = NULL;
+
+       if (tx->key) {
+               tx->key->tx_rx_count++;
+               if (unlikely(tx->local->key_tx_rx_threshold &&
+                            tx->key->tx_rx_count >
+                            tx->local->key_tx_rx_threshold)) {
+                       ieee80211_key_threshold_notify(tx->dev, tx->key,
+                                                      tx->sta);
+               }
+       }
+
+       return TXRX_CONTINUE;
+}
+
+static ieee80211_txrx_result
+ieee80211_tx_h_fragment(struct ieee80211_txrx_data *tx)
+{
+       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
+       size_t hdrlen, per_fragm, num_fragm, payload_len, left;
+       struct sk_buff **frags, *first, *frag;
+       int i;
+       u16 seq;
+       u8 *pos;
+       int frag_threshold = tx->local->fragmentation_threshold;
+
+       if (!tx->fragmented)
+               return TXRX_CONTINUE;
+
+       first = tx->skb;
+
+       hdrlen = ieee80211_get_hdrlen(tx->fc);
+       payload_len = first->len - hdrlen;
+       per_fragm = frag_threshold - hdrlen - FCS_LEN;
+       num_fragm = (payload_len + per_fragm - 1) / per_fragm;
+
+       frags = kzalloc(num_fragm * sizeof(struct sk_buff *), GFP_ATOMIC);
+       if (!frags)
+               goto fail;
+
+       hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
+       seq = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_SEQ;
+       pos = first->data + hdrlen + per_fragm;
+       left = payload_len - per_fragm;
+       for (i = 0; i < num_fragm - 1; i++) {
+               struct ieee80211_hdr *fhdr;
+               size_t copylen;
+
+               if (left <= 0)
+                       goto fail;
+
+               /* reserve enough extra head and tail room for possible
+                * encryption */
+               frag = frags[i] =
+                       dev_alloc_skb(tx->local->tx_headroom +
+                                     frag_threshold +
+                                     IEEE80211_ENCRYPT_HEADROOM +
+                                     IEEE80211_ENCRYPT_TAILROOM);
+               if (!frag)
+                       goto fail;
+               /* Make sure that all fragments use the same priority so
+                * that they end up using the same TX queue */
+               frag->priority = first->priority;
+               skb_reserve(frag, tx->local->tx_headroom +
+                                 IEEE80211_ENCRYPT_HEADROOM);
+               fhdr = (struct ieee80211_hdr *) skb_put(frag, hdrlen);
+               memcpy(fhdr, first->data, hdrlen);
+               if (i == num_fragm - 2)
+                       fhdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREFRAGS);
+               fhdr->seq_ctrl = cpu_to_le16(seq | ((i + 1) & IEEE80211_SCTL_FRAG));
+               copylen = left > per_fragm ? per_fragm : left;
+               memcpy(skb_put(frag, copylen), pos, copylen);
+
+               pos += copylen;
+               left -= copylen;
+       }
+       skb_trim(first, hdrlen + per_fragm);
+
+       tx->u.tx.num_extra_frag = num_fragm - 1;
+       tx->u.tx.extra_frag = frags;
+
+       return TXRX_CONTINUE;
+
+ fail:
+       printk(KERN_DEBUG "%s: failed to fragment frame\n", tx->dev->name);
+       if (frags) {
+               for (i = 0; i < num_fragm - 1; i++)
+                       if (frags[i])
+                               dev_kfree_skb(frags[i]);
+               kfree(frags);
+       }
+       I802_DEBUG_INC(tx->local->tx_handlers_drop_fragment);
+       return TXRX_DROP;
+}
+
+static int wep_encrypt_skb(struct ieee80211_txrx_data *tx, struct sk_buff *skb)
+{
+       if (tx->key->force_sw_encrypt) {
+               if (ieee80211_wep_encrypt(tx->local, skb, tx->key))
+                       return -1;
+       } else {
+               tx->u.tx.control->key_idx = tx->key->hw_key_idx;
+               if (tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) {
+                       if (ieee80211_wep_add_iv(tx->local, skb, tx->key) ==
+                           NULL)
+                               return -1;
+               }
+       }
+       return 0;
+}
+
+static ieee80211_txrx_result
+ieee80211_tx_h_wep_encrypt(struct ieee80211_txrx_data *tx)
+{
+       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
+       u16 fc;
+
+       fc = le16_to_cpu(hdr->frame_control);
+
+       if (!tx->key || tx->key->alg != ALG_WEP ||
+           ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
+            ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
+             (fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)))
+               return TXRX_CONTINUE;
+
+       tx->u.tx.control->iv_len = WEP_IV_LEN;
+       tx->u.tx.control->icv_len = WEP_ICV_LEN;
+       ieee80211_tx_set_iswep(tx);
+
+       if (wep_encrypt_skb(tx, tx->skb) < 0) {
+               I802_DEBUG_INC(tx->local->tx_handlers_drop_wep);
+               return TXRX_DROP;
+       }
+
+       if (tx->u.tx.extra_frag) {
+               int i;
+               for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
+                       if (wep_encrypt_skb(tx, tx->u.tx.extra_frag[i]) < 0) {
+                               I802_DEBUG_INC(tx->local->
+                                              tx_handlers_drop_wep);
+                               return TXRX_DROP;
+                       }
+               }
+       }
+
+       return TXRX_CONTINUE;
+}
+
+static ieee80211_txrx_result
+ieee80211_tx_h_rate_ctrl(struct ieee80211_txrx_data *tx)
+{
+       struct rate_control_extra extra;
+
+       memset(&extra, 0, sizeof(extra));
+       extra.mode = tx->u.tx.mode;
+       extra.mgmt_data = tx->sdata &&
+               tx->sdata->type == IEEE80211_IF_TYPE_MGMT;
+       extra.ethertype = tx->ethertype;
+
+       tx->u.tx.rate = rate_control_get_rate(tx->local, tx->dev, tx->skb,
+                                             &extra);
+       if (unlikely(extra.probe != NULL)) {
+               tx->u.tx.control->flags |= IEEE80211_TXCTL_RATE_CTRL_PROBE;
+               tx->u.tx.probe_last_frag = 1;
+               tx->u.tx.control->alt_retry_rate = tx->u.tx.rate->val;
+               tx->u.tx.rate = extra.probe;
+       } else {
+               tx->u.tx.control->alt_retry_rate = -1;
+       }
+       if (!tx->u.tx.rate)
+               return TXRX_DROP;
+       if (tx->u.tx.mode->mode == MODE_IEEE80211G &&
+           tx->sdata->use_protection && tx->fragmented &&
+           extra.nonerp) {
+               tx->u.tx.last_frag_rate = tx->u.tx.rate;
+               tx->u.tx.probe_last_frag = extra.probe ? 1 : 0;
+
+               tx->u.tx.rate = extra.nonerp;
+               tx->u.tx.control->rate = extra.nonerp;
+               tx->u.tx.control->flags &= ~IEEE80211_TXCTL_RATE_CTRL_PROBE;
+       } else {
+               tx->u.tx.last_frag_rate = tx->u.tx.rate;
+               tx->u.tx.control->rate = tx->u.tx.rate;
+       }
+       tx->u.tx.control->tx_rate = tx->u.tx.rate->val;
+       if ((tx->u.tx.rate->flags & IEEE80211_RATE_PREAMBLE2) &&
+           tx->local->short_preamble &&
+           (!tx->sta || (tx->sta->flags & WLAN_STA_SHORT_PREAMBLE))) {
+               tx->u.tx.short_preamble = 1;
+               tx->u.tx.control->tx_rate = tx->u.tx.rate->val2;
+       }
+
+       return TXRX_CONTINUE;
+}
+
+static ieee80211_txrx_result
+ieee80211_tx_h_misc(struct ieee80211_txrx_data *tx)
+{
+       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
+       u16 dur;
+       struct ieee80211_tx_control *control = tx->u.tx.control;
+       struct ieee80211_hw_mode *mode = tx->u.tx.mode;
+
+       if (!is_multicast_ether_addr(hdr->addr1)) {
+               if (tx->skb->len + FCS_LEN > tx->local->rts_threshold &&
+                   tx->local->rts_threshold < IEEE80211_MAX_RTS_THRESHOLD) {
+                       control->flags |= IEEE80211_TXCTL_USE_RTS_CTS;
+                       control->retry_limit =
+                               tx->local->long_retry_limit;
+               } else {
+                       control->retry_limit =
+                               tx->local->short_retry_limit;
+               }
+       } else {
+               control->retry_limit = 1;
+       }
+
+       if (tx->fragmented) {
+               /* Do not use multiple retry rates when sending fragmented
+                * frames.
+                * TODO: The last fragment could still use multiple retry
+                * rates. */
+               control->alt_retry_rate = -1;
+       }
+
+       /* Use CTS protection for unicast frames sent using extended rates if
+        * there are associated non-ERP stations and RTS/CTS is not configured
+        * for the frame. */
+       if (mode->mode == MODE_IEEE80211G &&
+           (tx->u.tx.rate->flags & IEEE80211_RATE_ERP) &&
+           tx->u.tx.unicast && tx->sdata->use_protection &&
+           !(control->flags & IEEE80211_TXCTL_USE_RTS_CTS))
+               control->flags |= IEEE80211_TXCTL_USE_CTS_PROTECT;
+
+       /* Setup duration field for the first fragment of the frame. Duration
+        * for remaining fragments will be updated when they are being sent
+        * to low-level driver in ieee80211_tx(). */
+       dur = ieee80211_duration(tx, is_multicast_ether_addr(hdr->addr1),
+                                tx->fragmented ? tx->u.tx.extra_frag[0]->len :
+                                0);
+       hdr->duration_id = cpu_to_le16(dur);
+
+       if ((control->flags & IEEE80211_TXCTL_USE_RTS_CTS) ||
+           (control->flags & IEEE80211_TXCTL_USE_CTS_PROTECT)) {
+               struct ieee80211_rate *rate;
+
+               /* Do not use multiple retry rates when using RTS/CTS */
+               control->alt_retry_rate = -1;
+
+               /* Use min(data rate, max base rate) as CTS/RTS rate */
+               rate = tx->u.tx.rate;
+               while (rate > mode->rates &&
+                      !(rate->flags & IEEE80211_RATE_BASIC))
+                       rate--;
+
+               control->rts_cts_rate = rate->val;
+               control->rts_rate = rate;
+       }
+
+       if (tx->sta) {
+               tx->sta->tx_packets++;
+               tx->sta->tx_fragments++;
+               tx->sta->tx_bytes += tx->skb->len;
+               if (tx->u.tx.extra_frag) {
+                       int i;
+                       tx->sta->tx_fragments += tx->u.tx.num_extra_frag;
+                       for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
+                               tx->sta->tx_bytes +=
+                                       tx->u.tx.extra_frag[i]->len;
+                       }
+               }
+       }
+
+       return TXRX_CONTINUE;
+}
+
+static ieee80211_txrx_result
+ieee80211_tx_h_load_stats(struct ieee80211_txrx_data *tx)
+{
+       struct ieee80211_local *local = tx->local;
+       struct ieee80211_hw_mode *mode = tx->u.tx.mode;
+       struct sk_buff *skb = tx->skb;
+       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+       u32 load = 0, hdrtime;
+
+       /* TODO: this could be part of tx_status handling, so that the number
+        * of retries would be known; TX rate should in that case be stored
+        * somewhere with the packet */
+
+       /* Estimate total channel use caused by this frame */
+
+       /* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
+        * 1 usec = 1/8 * (1080 / 10) = 13.5 */
+
+       if (mode->mode == MODE_IEEE80211A ||
+           mode->mode == MODE_ATHEROS_TURBO ||
+           mode->mode == MODE_ATHEROS_TURBOG ||
+           (mode->mode == MODE_IEEE80211G &&
+            tx->u.tx.rate->flags & IEEE80211_RATE_ERP))
+               hdrtime = CHAN_UTIL_HDR_SHORT;
+       else
+               hdrtime = CHAN_UTIL_HDR_LONG;
+
+       load = hdrtime;
+       if (!is_multicast_ether_addr(hdr->addr1))
+               load += hdrtime;
+
+       if (tx->u.tx.control->flags & IEEE80211_TXCTL_USE_RTS_CTS)
+               load += 2 * hdrtime;
+       else if (tx->u.tx.control->flags & IEEE80211_TXCTL_USE_CTS_PROTECT)
+               load += hdrtime;
+
+       load += skb->len * tx->u.tx.rate->rate_inv;
+
+       if (tx->u.tx.extra_frag) {
+               int i;
+               for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
+                       load += 2 * hdrtime;
+                       load += tx->u.tx.extra_frag[i]->len *
+                               tx->u.tx.rate->rate;
+               }
+       }
+
+       /* Divide channel_use by 8 to avoid wrapping around the counter */
+       load >>= CHAN_UTIL_SHIFT;
+       local->channel_use_raw += load;
+       if (tx->sta)
+               tx->sta->channel_use_raw += load;
+       tx->sdata->channel_use_raw += load;
+
+       return TXRX_CONTINUE;
+}
+
+/* TODO: implement register/unregister functions for adding TX/RX handlers
+ * into ordered list */
+
+ieee80211_tx_handler ieee80211_tx_handlers[] =
+{
+       ieee80211_tx_h_check_assoc,
+       ieee80211_tx_h_sequence,
+       ieee80211_tx_h_ps_buf,
+       ieee80211_tx_h_select_key,
+       ieee80211_tx_h_michael_mic_add,
+       ieee80211_tx_h_fragment,
+       ieee80211_tx_h_tkip_encrypt,
+       ieee80211_tx_h_ccmp_encrypt,
+       ieee80211_tx_h_wep_encrypt,
+       ieee80211_tx_h_rate_ctrl,
+       ieee80211_tx_h_misc,
+       ieee80211_tx_h_load_stats,
+       NULL
+};
+
+/* actual transmit path */
+
+/*
+ * deal with packet injection down monitor interface
+ * with Radiotap Header -- only called for monitor mode interface
+ */
+static ieee80211_txrx_result
+__ieee80211_parse_tx_radiotap(
+       struct ieee80211_txrx_data *tx,
+       struct sk_buff *skb, struct ieee80211_tx_control *control)
+{
+       /*
+        * this is the moment to interpret and discard the radiotap header that
+        * must be at the start of the packet injected in Monitor mode
+        *
+        * Need to take some care with endian-ness since radiotap
+        * args are little-endian
+        */
+
+       struct ieee80211_radiotap_iterator iterator;
+       struct ieee80211_radiotap_header *rthdr =
+               (struct ieee80211_radiotap_header *) skb->data;
+       struct ieee80211_hw_mode *mode = tx->local->hw.conf.mode;
+       int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len);
+
+       /*
+        * default control situation for all injected packets
+        * FIXME: this does not suit all usage cases, expand to allow control
+        */
+
+       control->retry_limit = 1; /* no retry */
+       control->key_idx = -1; /* no encryption key */
+       control->flags &= ~(IEEE80211_TXCTL_USE_RTS_CTS |
+                           IEEE80211_TXCTL_USE_CTS_PROTECT);
+       control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT |
+                         IEEE80211_TXCTL_NO_ACK;
+       control->antenna_sel_tx = 0; /* default to default antenna */
+
+       /*
+        * for every radiotap entry that is present
+        * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
+        * entries present, or -EINVAL on error)
+        */
+
+       while (!ret) {
+               int i, target_rate;
+
+               ret = ieee80211_radiotap_iterator_next(&iterator);
+
+               if (ret)
+                       continue;
+
+               /* see if this argument is something we can use */
+               switch (iterator.this_arg_index) {
+               /*
+                * You must take care when dereferencing iterator.this_arg
+                * for multibyte types... the pointer is not aligned.  Use
+                * get_unaligned((type *)iterator.this_arg) to dereference
+                * iterator.this_arg for type "type" safely on all arches.
+               */
+               case IEEE80211_RADIOTAP_RATE:
+                       /*
+                        * radiotap rate u8 is in 500kbps units eg, 0x02=1Mbps
+                        * ieee80211 rate int is in 100kbps units eg, 0x0a=1Mbps
+                        */
+                       target_rate = (*iterator.this_arg) * 5;
+                       for (i = 0; i < mode->num_rates; i++) {
+                               struct ieee80211_rate *r = &mode->rates[i];
+
+                               if (r->rate > target_rate)
+                                       continue;
+
+                               control->rate = r;
+
+                               if (r->flags & IEEE80211_RATE_PREAMBLE2)
+                                       control->tx_rate = r->val2;
+                               else
+                                       control->tx_rate = r->val;
+
+                               /* end on exact match */
+                               if (r->rate == target_rate)
+                                       i = mode->num_rates;
+                       }
+                       break;
+
+               case IEEE80211_RADIOTAP_ANTENNA:
+                       /*
+                        * radiotap uses 0 for 1st ant, mac80211 is 1 for
+                        * 1st ant
+                        */
+                       control->antenna_sel_tx = (*iterator.this_arg) + 1;
+                       break;
+
+               case IEEE80211_RADIOTAP_DBM_TX_POWER:
+                       control->power_level = *iterator.this_arg;
+                       break;
+
+               case IEEE80211_RADIOTAP_FLAGS:
+                       if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
+                               /*
+                                * this indicates that the skb we have been
+                                * handed has the 32-bit FCS CRC at the end...
+                                * we should react to that by snipping it off
+                                * because it will be recomputed and added
+                                * on transmission
+                                */
+                               if (skb->len < (iterator.max_length + FCS_LEN))
+                                       return TXRX_DROP;
+
+                               skb_trim(skb, skb->len - FCS_LEN);
+                       }
+                       break;
+
+               default:
+                       break;
+               }
+       }
+
+       if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
+               return TXRX_DROP;
+
+       /*
+        * remove the radiotap header
+        * iterator->max_length was sanity-checked against
+        * skb->len by iterator init
+        */
+       skb_pull(skb, iterator.max_length);
+
+       return TXRX_CONTINUE;
+}
+
+static ieee80211_txrx_result inline
+__ieee80211_tx_prepare(struct ieee80211_txrx_data *tx,
+                      struct sk_buff *skb,
+                      struct net_device *dev,
+                      struct ieee80211_tx_control *control)
+{
+       struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+       struct ieee80211_sub_if_data *sdata;
+       ieee80211_txrx_result res = TXRX_CONTINUE;
+
+       int hdrlen;
+
+       memset(tx, 0, sizeof(*tx));
+       tx->skb = skb;
+       tx->dev = dev; /* use original interface */
+       tx->local = local;
+       tx->sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+       tx->sta = sta_info_get(local, hdr->addr1);
+       tx->fc = le16_to_cpu(hdr->frame_control);
+
+       /*
+        * set defaults for things that can be set by
+        * injected radiotap headers
+        */
+       control->power_level = local->hw.conf.power_level;
+       control->antenna_sel_tx = local->hw.conf.antenna_sel_tx;
+       if (local->sta_antenna_sel != STA_ANTENNA_SEL_AUTO && tx->sta)
+               control->antenna_sel_tx = tx->sta->antenna_sel_tx;
+
+       /* process and remove the injection radiotap header */
+       sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+       if (unlikely(sdata->type == IEEE80211_IF_TYPE_MNTR)) {
+               if (__ieee80211_parse_tx_radiotap(tx, skb, control) ==
+                                                               TXRX_DROP) {
+                       return TXRX_DROP;
+               }
+               /*
+                * we removed the radiotap header after this point,
+                * we filled control with what we could use
+                * set to the actual ieee header now
+                */
+               hdr = (struct ieee80211_hdr *) skb->data;
+               res = TXRX_QUEUED; /* indication it was monitor packet */
+       }
+
+       tx->u.tx.control = control;
+       tx->u.tx.unicast = !is_multicast_ether_addr(hdr->addr1);
+       if (is_multicast_ether_addr(hdr->addr1))
+               control->flags |= IEEE80211_TXCTL_NO_ACK;
+       else
+               control->flags &= ~IEEE80211_TXCTL_NO_ACK;
+       tx->fragmented = local->fragmentation_threshold <
+               IEEE80211_MAX_FRAG_THRESHOLD && tx->u.tx.unicast &&
+               skb->len + FCS_LEN > local->fragmentation_threshold &&
+               (!local->ops->set_frag_threshold);
+       if (!tx->sta)
+               control->flags |= IEEE80211_TXCTL_CLEAR_DST_MASK;
+       else if (tx->sta->clear_dst_mask) {
+               control->flags |= IEEE80211_TXCTL_CLEAR_DST_MASK;
+               tx->sta->clear_dst_mask = 0;
+       }
+       hdrlen = ieee80211_get_hdrlen(tx->fc);
+       if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
+               u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
+               tx->ethertype = (pos[0] << 8) | pos[1];
+       }
+       control->flags |= IEEE80211_TXCTL_FIRST_FRAGMENT;
+
+       return res;
+}
+
+/* Device in tx->dev has a reference added; use dev_put(tx->dev) when
+ * finished with it. */
+static int inline ieee80211_tx_prepare(struct ieee80211_txrx_data *tx,
+                                      struct sk_buff *skb,
+                                      struct net_device *mdev,
+                                      struct ieee80211_tx_control *control)
+{
+       struct ieee80211_tx_packet_data *pkt_data;
+       struct net_device *dev;
+
+       pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
+       dev = dev_get_by_index(pkt_data->ifindex);
+       if (unlikely(dev && !is_ieee80211_device(dev, mdev))) {
+               dev_put(dev);
+               dev = NULL;
+       }
+       if (unlikely(!dev))
+               return -ENODEV;
+       __ieee80211_tx_prepare(tx, skb, dev, control);
+       return 0;
+}
+
+static int __ieee80211_tx(struct ieee80211_local *local, struct sk_buff *skb,
+                         struct ieee80211_txrx_data *tx)
+{
+       struct ieee80211_tx_control *control = tx->u.tx.control;
+       int ret, i;
+
+       if (!ieee80211_qdisc_installed(local->mdev) &&
+           __ieee80211_queue_stopped(local, 0)) {
+               netif_stop_queue(local->mdev);
+               return IEEE80211_TX_AGAIN;
+       }
+       if (skb) {
+               ieee80211_dump_frame(local->mdev->name, "TX to low-level driver", skb);
+               ret = local->ops->tx(local_to_hw(local), skb, control);
+               if (ret)
+                       return IEEE80211_TX_AGAIN;
+               local->mdev->trans_start = jiffies;
+               ieee80211_led_tx(local, 1);
+       }
+       if (tx->u.tx.extra_frag) {
+               control->flags &= ~(IEEE80211_TXCTL_USE_RTS_CTS |
+                                   IEEE80211_TXCTL_USE_CTS_PROTECT |
+                                   IEEE80211_TXCTL_CLEAR_DST_MASK |
+                                   IEEE80211_TXCTL_FIRST_FRAGMENT);
+               for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
+                       if (!tx->u.tx.extra_frag[i])
+                               continue;
+                       if (__ieee80211_queue_stopped(local, control->queue))
+                               return IEEE80211_TX_FRAG_AGAIN;
+                       if (i == tx->u.tx.num_extra_frag) {
+                               control->tx_rate = tx->u.tx.last_frag_hwrate;
+                               control->rate = tx->u.tx.last_frag_rate;
+                               if (tx->u.tx.probe_last_frag)
+                                       control->flags |=
+                                               IEEE80211_TXCTL_RATE_CTRL_PROBE;
+                               else
+                                       control->flags &=
+                                               ~IEEE80211_TXCTL_RATE_CTRL_PROBE;
+                       }
+
+                       ieee80211_dump_frame(local->mdev->name,
+                                            "TX to low-level driver",
+                                            tx->u.tx.extra_frag[i]);
+                       ret = local->ops->tx(local_to_hw(local),
+                                           tx->u.tx.extra_frag[i],
+                                           control);
+                       if (ret)
+                               return IEEE80211_TX_FRAG_AGAIN;
+                       local->mdev->trans_start = jiffies;
+                       ieee80211_led_tx(local, 1);
+                       tx->u.tx.extra_frag[i] = NULL;
+               }
+               kfree(tx->u.tx.extra_frag);
+               tx->u.tx.extra_frag = NULL;
+       }
+       return IEEE80211_TX_OK;
+}
+
+static int ieee80211_tx(struct net_device *dev, struct sk_buff *skb,
+                       struct ieee80211_tx_control *control, int mgmt)
+{
+       struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+       struct sta_info *sta;
+       ieee80211_tx_handler *handler;
+       struct ieee80211_txrx_data tx;
+       ieee80211_txrx_result res = TXRX_DROP, res_prepare;
+       int ret, i;
+
+       WARN_ON(__ieee80211_queue_pending(local, control->queue));
+
+       if (unlikely(skb->len < 10)) {
+               dev_kfree_skb(skb);
+               return 0;
+       }
+
+       res_prepare = __ieee80211_tx_prepare(&tx, skb, dev, control);
+
+       if (res_prepare == TXRX_DROP) {
+               dev_kfree_skb(skb);
+               return 0;
+       }
+
+       sta = tx.sta;
+       tx.u.tx.mgmt_interface = mgmt;
+       tx.u.tx.mode = local->hw.conf.mode;
+
+       if (res_prepare == TXRX_QUEUED) { /* if it was an injected packet */
+               res = TXRX_CONTINUE;
+       } else {
+               for (handler = local->tx_handlers; *handler != NULL;
+                    handler++) {
+                       res = (*handler)(&tx);
+                       if (res != TXRX_CONTINUE)
+                               break;
+               }
+       }
+
+       skb = tx.skb; /* handlers are allowed to change skb */
+
+       if (sta)
+               sta_info_put(sta);
+
+       if (unlikely(res == TXRX_DROP)) {
+               I802_DEBUG_INC(local->tx_handlers_drop);
+               goto drop;
+       }
+
+       if (unlikely(res == TXRX_QUEUED)) {
+               I802_DEBUG_INC(local->tx_handlers_queued);
+               return 0;
+       }
+
+       if (tx.u.tx.extra_frag) {
+               for (i = 0; i < tx.u.tx.num_extra_frag; i++) {
+                       int next_len, dur;
+                       struct ieee80211_hdr *hdr =
+                               (struct ieee80211_hdr *)
+                               tx.u.tx.extra_frag[i]->data;
+
+                       if (i + 1 < tx.u.tx.num_extra_frag) {
+                               next_len = tx.u.tx.extra_frag[i + 1]->len;
+                       } else {
+                               next_len = 0;
+                               tx.u.tx.rate = tx.u.tx.last_frag_rate;
+                               tx.u.tx.last_frag_hwrate = tx.u.tx.rate->val;
+                       }
+                       dur = ieee80211_duration(&tx, 0, next_len);
+                       hdr->duration_id = cpu_to_le16(dur);
+               }
+       }
+
+retry:
+       ret = __ieee80211_tx(local, skb, &tx);
+       if (ret) {
+               struct ieee80211_tx_stored_packet *store =
+                       &local->pending_packet[control->queue];
+
+               if (ret == IEEE80211_TX_FRAG_AGAIN)
+                       skb = NULL;
+               set_bit(IEEE80211_LINK_STATE_PENDING,
+                       &local->state[control->queue]);
+               smp_mb();
+               /* When the driver gets out of buffers during sending of
+                * fragments and calls ieee80211_stop_queue, there is
+                * a small window between IEEE80211_LINK_STATE_XOFF and
+                * IEEE80211_LINK_STATE_PENDING flags are set. If a buffer
+                * gets available in that window (i.e. driver calls
+                * ieee80211_wake_queue), we would end up with ieee80211_tx
+                * called with IEEE80211_LINK_STATE_PENDING. Prevent this by
+                * continuing transmitting here when that situation is
+                * possible to have happened. */
+               if (!__ieee80211_queue_stopped(local, control->queue)) {
+                       clear_bit(IEEE80211_LINK_STATE_PENDING,
+                                 &local->state[control->queue]);
+                       goto retry;
+               }
+               memcpy(&store->control, control,
+                      sizeof(struct ieee80211_tx_control));
+               store->skb = skb;
+               store->extra_frag = tx.u.tx.extra_frag;
+               store->num_extra_frag = tx.u.tx.num_extra_frag;
+               store->last_frag_hwrate = tx.u.tx.last_frag_hwrate;
+               store->last_frag_rate = tx.u.tx.last_frag_rate;
+               store->last_frag_rate_ctrl_probe = tx.u.tx.probe_last_frag;
+       }
+       return 0;
+
+ drop:
+       if (skb)
+               dev_kfree_skb(skb);
+       for (i = 0; i < tx.u.tx.num_extra_frag; i++)
+               if (tx.u.tx.extra_frag[i])
+                       dev_kfree_skb(tx.u.tx.extra_frag[i]);
+       kfree(tx.u.tx.extra_frag);
+       return 0;
+}
+
+/* device xmit handlers */
+
+int ieee80211_master_start_xmit(struct sk_buff *skb,
+                               struct net_device *dev)
+{
+       struct ieee80211_tx_control control;
+       struct ieee80211_tx_packet_data *pkt_data;
+       struct net_device *odev = NULL;
+       struct ieee80211_sub_if_data *osdata;
+       int headroom;
+       int ret;
+
+       /*
+        * copy control out of the skb so other people can use skb->cb
+        */
+       pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
+       memset(&control, 0, sizeof(struct ieee80211_tx_control));
+
+       if (pkt_data->ifindex)
+               odev = dev_get_by_index(pkt_data->ifindex);
+       if (unlikely(odev && !is_ieee80211_device(odev, dev))) {
+               dev_put(odev);
+               odev = NULL;
+       }
+       if (unlikely(!odev)) {
+#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
+               printk(KERN_DEBUG "%s: Discarded packet with nonexistent "
+                      "originating device\n", dev->name);
+#endif
+               dev_kfree_skb(skb);
+               return 0;
+       }
+       osdata = IEEE80211_DEV_TO_SUB_IF(odev);
+
+       headroom = osdata->local->tx_headroom + IEEE80211_ENCRYPT_HEADROOM;
+       if (skb_headroom(skb) < headroom) {
+               if (pskb_expand_head(skb, headroom, 0, GFP_ATOMIC)) {
+                       dev_kfree_skb(skb);
+                       dev_put(odev);
+                       return 0;
+               }
+       }
+
+       control.ifindex = odev->ifindex;
+       control.type = osdata->type;
+       if (pkt_data->req_tx_status)
+               control.flags |= IEEE80211_TXCTL_REQ_TX_STATUS;
+       if (pkt_data->do_not_encrypt)
+               control.flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
+       if (pkt_data->requeue)
+               control.flags |= IEEE80211_TXCTL_REQUEUE;
+       control.queue = pkt_data->queue;
+
+       ret = ieee80211_tx(odev, skb, &control,
+                          control.type == IEEE80211_IF_TYPE_MGMT);
+       dev_put(odev);
+
+       return ret;
+}
+
+int ieee80211_monitor_start_xmit(struct sk_buff *skb,
+                                struct net_device *dev)
+{
+       struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+       struct ieee80211_tx_packet_data *pkt_data;
+       struct ieee80211_radiotap_header *prthdr =
+               (struct ieee80211_radiotap_header *)skb->data;
+       u16 len;
+
+       /*
+        * there must be a radiotap header at the
+        * start in this case
+        */
+       if (unlikely(prthdr->it_version)) {
+               /* only version 0 is supported */
+               dev_kfree_skb(skb);
+               return NETDEV_TX_OK;
+       }
+
+       skb->dev = local->mdev;
+
+       pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
+       memset(pkt_data, 0, sizeof(*pkt_data));
+       pkt_data->ifindex = dev->ifindex;
+       pkt_data->mgmt_iface = 0;
+       pkt_data->do_not_encrypt = 1;
+
+       /* above needed because we set skb device to master */
+
+       /*
+        * fix up the pointers accounting for the radiotap
+        * header still being in there.  We are being given
+        * a precooked IEEE80211 header so no need for
+        * normal processing
+        */
+       len = le16_to_cpu(get_unaligned(&prthdr->it_len));
+       skb_set_mac_header(skb, len);
+       skb_set_network_header(skb, len + sizeof(struct ieee80211_hdr));
+       skb_set_transport_header(skb, len + sizeof(struct ieee80211_hdr));
+
+       /*
+        * pass the radiotap header up to
+        * the next stage intact
+        */
+       dev_queue_xmit(skb);
+
+       return NETDEV_TX_OK;
+}
+
+/**
+ * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
+ * subinterfaces (wlan#, WDS, and VLAN interfaces)
+ * @skb: packet to be sent
+ * @dev: incoming interface
+ *
+ * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
+ * not be freed, and caller is responsible for either retrying later or freeing
+ * skb).
+ *
+ * This function takes in an Ethernet header and encapsulates it with suitable
+ * IEEE 802.11 header based on which interface the packet is coming in. The
+ * encapsulated packet will then be passed to master interface, wlan#.11, for
+ * transmission (through low-level driver).
+ */
+int ieee80211_subif_start_xmit(struct sk_buff *skb,
+                              struct net_device *dev)
+{
+       struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+       struct ieee80211_tx_packet_data *pkt_data;
+       struct ieee80211_sub_if_data *sdata;
+       int ret = 1, head_need;
+       u16 ethertype, hdrlen, fc;
+       struct ieee80211_hdr hdr;
+       const u8 *encaps_data;
+       int encaps_len, skip_header_bytes;
+       int nh_pos, h_pos, no_encrypt = 0;
+       struct sta_info *sta;
+
+       sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+       if (unlikely(skb->len < ETH_HLEN)) {
+               printk(KERN_DEBUG "%s: short skb (len=%d)\n",
+                      dev->name, skb->len);
+               ret = 0;
+               goto fail;
+       }
+
+       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];
+       /* TODO: handling for 802.1x authorized/unauthorized port */
+       fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA;
+
+       if (likely(sdata->type == IEEE80211_IF_TYPE_AP ||
+                  sdata->type == IEEE80211_IF_TYPE_VLAN)) {
+               fc |= IEEE80211_FCTL_FROMDS;
+               /* DA BSSID SA */
+               memcpy(hdr.addr1, skb->data, ETH_ALEN);
+               memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
+               memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
+               hdrlen = 24;
+       } else if (sdata->type == IEEE80211_IF_TYPE_WDS) {
+               fc |= IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS;
+               /* RA TA DA SA */
+               memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
+               memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
+               memcpy(hdr.addr3, skb->data, ETH_ALEN);
+               memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
+               hdrlen = 30;
+       } else if (sdata->type == IEEE80211_IF_TYPE_STA) {
+               fc |= IEEE80211_FCTL_TODS;
+               /* BSSID SA DA */
+               memcpy(hdr.addr1, sdata->u.sta.bssid, ETH_ALEN);
+               memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
+               memcpy(hdr.addr3, skb->data, ETH_ALEN);
+               hdrlen = 24;
+       } else if (sdata->type == IEEE80211_IF_TYPE_IBSS) {
+               /* DA SA BSSID */
+               memcpy(hdr.addr1, skb->data, ETH_ALEN);
+               memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
+               memcpy(hdr.addr3, sdata->u.sta.bssid, ETH_ALEN);
+               hdrlen = 24;
+       } else {
+               ret = 0;
+               goto fail;
+       }
+
+       /* receiver is QoS enabled, use a QoS type frame */
+       sta = sta_info_get(local, hdr.addr1);
+       if (sta) {
+               if (sta->flags & WLAN_STA_WME) {
+                       fc |= IEEE80211_STYPE_QOS_DATA;
+                       hdrlen += 2;
+               }
+               sta_info_put(sta);
+       }
+
+       hdr.frame_control = cpu_to_le16(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 >= 0x600) {
+               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;
+
+       /* TODO: implement support for fragments so that there is no need to
+        * reallocate and copy payload; it might be enough to support one
+        * extra fragment that would be copied in the beginning of the frame
+        * data.. anyway, it would be nice to include this into skb structure
+        * somehow
+        *
+        * There are few options for this:
+        * use skb->cb as an extra space for 802.11 header
+        * allocate new buffer if not enough headroom
+        * make sure that there is enough headroom in every skb by increasing
+        * build in headroom in __dev_alloc_skb() (linux/skbuff.h) and
+        * alloc_skb() (net/core/skbuff.c)
+        */
+       head_need = hdrlen + encaps_len + local->tx_headroom;
+       head_need -= skb_headroom(skb);
+
+       /* We are going to modify skb data, so make a copy of it if happens to
+        * be cloned. This could happen, e.g., with Linux bridge code passing
+        * us broadcast frames. */
+
+       if (head_need > 0 || skb_cloned(skb)) {
+#if 0
+               printk(KERN_DEBUG "%s: need to reallocate buffer for %d bytes "
+                      "of headroom\n", dev->name, head_need);
+#endif
+
+               if (skb_cloned(skb))
+                       I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
+               else
+                       I802_DEBUG_INC(local->tx_expand_skb_head);
+               /* Since we have to reallocate the buffer, make sure that there
+                * is enough room for possible WEP IV/ICV and TKIP (8 bytes
+                * before payload and 12 after). */
+               if (pskb_expand_head(skb, (head_need > 0 ? head_need + 8 : 8),
+                                    12, GFP_ATOMIC)) {
+                       printk(KERN_DEBUG "%s: failed to reallocate TX buffer"
+                              "\n", dev->name);
+                       goto fail;
+               }
+       }
+
+       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;
+
+       pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
+       memset(pkt_data, 0, sizeof(struct ieee80211_tx_packet_data));
+       pkt_data->ifindex = dev->ifindex;
+       pkt_data->mgmt_iface = (sdata->type == IEEE80211_IF_TYPE_MGMT);
+       pkt_data->do_not_encrypt = no_encrypt;
+
+       skb->dev = local->mdev;
+       sdata->stats.tx_packets++;
+       sdata->stats.tx_bytes += skb->len;
+
+       /* 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_set_mac_header(skb, 0);
+       skb_set_network_header(skb, nh_pos);
+       skb_set_transport_header(skb, h_pos);
+
+       dev->trans_start = jiffies;
+       dev_queue_xmit(skb);
+
+       return 0;
+
+ fail:
+       if (!ret)
+               dev_kfree_skb(skb);
+
+       return ret;
+}
+
+/*
+ * This is the transmit routine for the 802.11 type interfaces
+ * called by upper layers of the linux networking
+ * stack when it has a frame to transmit
+ */
+int ieee80211_mgmt_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+       struct ieee80211_sub_if_data *sdata;
+       struct ieee80211_tx_packet_data *pkt_data;
+       struct ieee80211_hdr *hdr;
+       u16 fc;
+
+       sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+       if (skb->len < 10) {
+               dev_kfree_skb(skb);
+               return 0;
+       }
+
+       if (skb_headroom(skb) < sdata->local->tx_headroom) {
+               if (pskb_expand_head(skb, sdata->local->tx_headroom,
+                                    0, GFP_ATOMIC)) {
+                       dev_kfree_skb(skb);
+                       return 0;
+               }
+       }
+
+       hdr = (struct ieee80211_hdr *) skb->data;
+       fc = le16_to_cpu(hdr->frame_control);
+
+       pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
+       memset(pkt_data, 0, sizeof(struct ieee80211_tx_packet_data));
+       pkt_data->ifindex = sdata->dev->ifindex;
+       pkt_data->mgmt_iface = (sdata->type == IEEE80211_IF_TYPE_MGMT);
+
+       skb->priority = 20; /* use hardcoded priority for mgmt TX queue */
+       skb->dev = sdata->local->mdev;
+
+       /*
+        * We're using the protocol field of the the frame control header
+        * to request TX callback for hostapd. BIT(1) is checked.
+        */
+       if ((fc & BIT(1)) == BIT(1)) {
+               pkt_data->req_tx_status = 1;
+               fc &= ~BIT(1);
+               hdr->frame_control = cpu_to_le16(fc);
+       }
+
+       pkt_data->do_not_encrypt = !(fc & IEEE80211_FCTL_PROTECTED);
+
+       sdata->stats.tx_packets++;
+       sdata->stats.tx_bytes += skb->len;
+
+       dev_queue_xmit(skb);
+
+       return 0;
+}
+
+/* helper functions for pending packets for when queues are stopped */
+
+void ieee80211_clear_tx_pending(struct ieee80211_local *local)
+{
+       int i, j;
+       struct ieee80211_tx_stored_packet *store;
+
+       for (i = 0; i < local->hw.queues; i++) {
+               if (!__ieee80211_queue_pending(local, i))
+                       continue;
+               store = &local->pending_packet[i];
+               kfree_skb(store->skb);
+               for (j = 0; j < store->num_extra_frag; j++)
+                       kfree_skb(store->extra_frag[j]);
+               kfree(store->extra_frag);
+               clear_bit(IEEE80211_LINK_STATE_PENDING, &local->state[i]);
+       }
+}
+
+void ieee80211_tx_pending(unsigned long data)
+{
+       struct ieee80211_local *local = (struct ieee80211_local *)data;
+       struct net_device *dev = local->mdev;
+       struct ieee80211_tx_stored_packet *store;
+       struct ieee80211_txrx_data tx;
+       int i, ret, reschedule = 0;
+
+       netif_tx_lock_bh(dev);
+       for (i = 0; i < local->hw.queues; i++) {
+               if (__ieee80211_queue_stopped(local, i))
+                       continue;
+               if (!__ieee80211_queue_pending(local, i)) {
+                       reschedule = 1;
+                       continue;
+               }
+               store = &local->pending_packet[i];
+               tx.u.tx.control = &store->control;
+               tx.u.tx.extra_frag = store->extra_frag;
+               tx.u.tx.num_extra_frag = store->num_extra_frag;
+               tx.u.tx.last_frag_hwrate = store->last_frag_hwrate;
+               tx.u.tx.last_frag_rate = store->last_frag_rate;
+               tx.u.tx.probe_last_frag = store->last_frag_rate_ctrl_probe;
+               ret = __ieee80211_tx(local, store->skb, &tx);
+               if (ret) {
+                       if (ret == IEEE80211_TX_FRAG_AGAIN)
+                               store->skb = NULL;
+               } else {
+                       clear_bit(IEEE80211_LINK_STATE_PENDING,
+                                 &local->state[i]);
+                       reschedule = 1;
+               }
+       }
+       netif_tx_unlock_bh(dev);
+       if (reschedule) {
+               if (!ieee80211_qdisc_installed(dev)) {
+                       if (!__ieee80211_queue_stopped(local, 0))
+                               netif_wake_queue(dev);
+               } else
+                       netif_schedule(dev);
+       }
+}
+
+/* functions for drivers to get certain frames */
+
+static void ieee80211_beacon_add_tim(struct ieee80211_local *local,
+                                    struct ieee80211_if_ap *bss,
+                                    struct sk_buff *skb)
+{
+       u8 *pos, *tim;
+       int aid0 = 0;
+       int i, have_bits = 0, n1, n2;
+
+       /* Generate bitmap for TIM only if there are any STAs in power save
+        * mode. */
+       spin_lock_bh(&local->sta_lock);
+       if (atomic_read(&bss->num_sta_ps) > 0)
+               /* in the hope that this is faster than
+                * checking byte-for-byte */
+               have_bits = !bitmap_empty((unsigned long*)bss->tim,
+                                         IEEE80211_MAX_AID+1);
+
+       if (bss->dtim_count == 0)
+               bss->dtim_count = bss->dtim_period - 1;
+       else
+               bss->dtim_count--;
+
+       tim = pos = (u8 *) skb_put(skb, 6);
+       *pos++ = WLAN_EID_TIM;
+       *pos++ = 4;
+       *pos++ = bss->dtim_count;
+       *pos++ = bss->dtim_period;
+
+       if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
+               aid0 = 1;
+
+       if (have_bits) {
+               /* Find largest even number N1 so that bits numbered 1 through
+                * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
+                * (N2 + 1) x 8 through 2007 are 0. */
+               n1 = 0;
+               for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
+                       if (bss->tim[i]) {
+                               n1 = i & 0xfe;
+                               break;
+                       }
+               }
+               n2 = n1;
+               for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
+                       if (bss->tim[i]) {
+                               n2 = i;
+                               break;
+                       }
+               }
+
+               /* Bitmap control */
+               *pos++ = n1 | aid0;
+               /* Part Virt Bitmap */
+               memcpy(pos, bss->tim + n1, n2 - n1 + 1);
+
+               tim[1] = n2 - n1 + 4;
+               skb_put(skb, n2 - n1);
+       } else {
+               *pos++ = aid0; /* Bitmap control */
+               *pos++ = 0; /* Part Virt Bitmap */
+       }
+       spin_unlock_bh(&local->sta_lock);
+}
+
+struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw, int if_id,
+                                    struct ieee80211_tx_control *control)
+{
+       struct ieee80211_local *local = hw_to_local(hw);
+       struct sk_buff *skb;
+       struct net_device *bdev;
+       struct ieee80211_sub_if_data *sdata = NULL;
+       struct ieee80211_if_ap *ap = NULL;
+       struct ieee80211_rate *rate;
+       struct rate_control_extra extra;
+       u8 *b_head, *b_tail;
+       int bh_len, bt_len;
+
+       bdev = dev_get_by_index(if_id);
+       if (bdev) {
+               sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
+               ap = &sdata->u.ap;
+               dev_put(bdev);
+       }
+
+       if (!ap || sdata->type != IEEE80211_IF_TYPE_AP ||
+           !ap->beacon_head) {
+#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
+               if (net_ratelimit())
+                       printk(KERN_DEBUG "no beacon data avail for idx=%d "
+                              "(%s)\n", if_id, bdev ? bdev->name : "N/A");
+#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
+               return NULL;
+       }
+
+       /* Assume we are generating the normal beacon locally */
+       b_head = ap->beacon_head;
+       b_tail = ap->beacon_tail;
+       bh_len = ap->beacon_head_len;
+       bt_len = ap->beacon_tail_len;
+
+       skb = dev_alloc_skb(local->tx_headroom +
+               bh_len + bt_len + 256 /* maximum TIM len */);
+       if (!skb)
+               return NULL;
+
+       skb_reserve(skb, local->tx_headroom);
+       memcpy(skb_put(skb, bh_len), b_head, bh_len);
+
+       ieee80211_include_sequence(sdata, (struct ieee80211_hdr *)skb->data);
+
+       ieee80211_beacon_add_tim(local, ap, skb);
+
+       if (b_tail) {
+               memcpy(skb_put(skb, bt_len), b_tail, bt_len);
+       }
+
+       if (control) {
+               memset(&extra, 0, sizeof(extra));
+               extra.mode = local->oper_hw_mode;
+
+               rate = rate_control_get_rate(local, local->mdev, skb, &extra);
+               if (!rate) {
+                       if (net_ratelimit()) {
+                               printk(KERN_DEBUG "%s: ieee80211_beacon_get: no rate "
+                                      "found\n", local->mdev->name);
+                       }
+                       dev_kfree_skb(skb);
+                       return NULL;
+               }
+
+               control->tx_rate = (local->short_preamble &&
+                                   (rate->flags & IEEE80211_RATE_PREAMBLE2)) ?
+                       rate->val2 : rate->val;
+               control->antenna_sel_tx = local->hw.conf.antenna_sel_tx;
+               control->power_level = local->hw.conf.power_level;
+               control->flags |= IEEE80211_TXCTL_NO_ACK;
+               control->retry_limit = 1;
+               control->flags |= IEEE80211_TXCTL_CLEAR_DST_MASK;
+       }
+
+       ap->num_beacons++;
+       return skb;
+}
+EXPORT_SYMBOL(ieee80211_beacon_get);
+
+void ieee80211_rts_get(struct ieee80211_hw *hw,
+                      const void *frame, size_t frame_len,
+                      const struct ieee80211_tx_control *frame_txctl,
+                      struct ieee80211_rts *rts)
+{
+       const struct ieee80211_hdr *hdr = frame;
+       u16 fctl;
+
+       fctl = IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS;
+       rts->frame_control = cpu_to_le16(fctl);
+       rts->duration = ieee80211_rts_duration(hw, frame_len, frame_txctl);
+       memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
+       memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
+}
+EXPORT_SYMBOL(ieee80211_rts_get);
+
+void ieee80211_ctstoself_get(struct ieee80211_hw *hw,
+                            const void *frame, size_t frame_len,
+                            const struct ieee80211_tx_control *frame_txctl,
+                            struct ieee80211_cts *cts)
+{
+       const struct ieee80211_hdr *hdr = frame;
+       u16 fctl;
+
+       fctl = IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS;
+       cts->frame_control = cpu_to_le16(fctl);
+       cts->duration = ieee80211_ctstoself_duration(hw, frame_len, frame_txctl);
+       memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
+}
+EXPORT_SYMBOL(ieee80211_ctstoself_get);
+
+struct sk_buff *
+ieee80211_get_buffered_bc(struct ieee80211_hw *hw, int if_id,
+                         struct ieee80211_tx_control *control)
+{
+       struct ieee80211_local *local = hw_to_local(hw);
+       struct sk_buff *skb;
+       struct sta_info *sta;
+       ieee80211_tx_handler *handler;
+       struct ieee80211_txrx_data tx;
+       ieee80211_txrx_result res = TXRX_DROP;
+       struct net_device *bdev;
+       struct ieee80211_sub_if_data *sdata;
+       struct ieee80211_if_ap *bss = NULL;
+
+       bdev = dev_get_by_index(if_id);
+       if (bdev) {
+               sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
+               bss = &sdata->u.ap;
+               dev_put(bdev);
+       }
+       if (!bss || sdata->type != IEEE80211_IF_TYPE_AP || !bss->beacon_head)
+               return NULL;
+
+       if (bss->dtim_count != 0)
+               return NULL; /* send buffered bc/mc only after DTIM beacon */
+       memset(control, 0, sizeof(*control));
+       while (1) {
+               skb = skb_dequeue(&bss->ps_bc_buf);
+               if (!skb)
+                       return NULL;
+               local->total_ps_buffered--;
+
+               if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
+                       struct ieee80211_hdr *hdr =
+                               (struct ieee80211_hdr *) skb->data;
+                       /* more buffered multicast/broadcast frames ==> set
+                        * MoreData flag in IEEE 802.11 header to inform PS
+                        * STAs */
+                       hdr->frame_control |=
+                               cpu_to_le16(IEEE80211_FCTL_MOREDATA);
+               }
+
+               if (ieee80211_tx_prepare(&tx, skb, local->mdev, control) == 0)
+                       break;
+               dev_kfree_skb_any(skb);
+       }
+       sta = tx.sta;
+       tx.u.tx.ps_buffered = 1;
+
+       for (handler = local->tx_handlers; *handler != NULL; handler++) {
+               res = (*handler)(&tx);
+               if (res == TXRX_DROP || res == TXRX_QUEUED)
+                       break;
+       }
+       dev_put(tx.dev);
+       skb = tx.skb; /* handlers are allowed to change skb */
+
+       if (res == TXRX_DROP) {
+               I802_DEBUG_INC(local->tx_handlers_drop);
+               dev_kfree_skb(skb);
+               skb = NULL;
+       } else if (res == TXRX_QUEUED) {
+               I802_DEBUG_INC(local->tx_handlers_queued);
+               skb = NULL;
+       }
+
+       if (sta)
+               sta_info_put(sta);
+
+       return skb;
+}
+EXPORT_SYMBOL(ieee80211_get_buffered_bc);