diff options
Diffstat (limited to 'net/mac80211/tx.c')
| -rw-r--r-- | net/mac80211/tx.c | 1903 |
1 files changed, 1903 insertions, 0 deletions
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c new file mode 100644 index 0000000..1a53154 --- /dev/null +++ b/net/mac80211/tx.c @@ -0,0 +1,1903 @@ +/* + * 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 <linux/rcupdate.h> +#include <net/net_namespace.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; + DECLARE_MAC_BUF(mac); + + 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=%s", print_mac(mac, hdr->addr1)); + if (hdrlen >= 16) + printk(" A2=%s", print_mac(mac, hdr->addr2)); + if (hdrlen >= 24) + printk(" A3=%s", print_mac(mac, hdr->addr3)); + if (hdrlen >= 30) + printk(" A4=%s", print_mac(mac, 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, + tx->sdata->flags & IEEE80211_SDATA_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, + tx->sdata->flags & + IEEE80211_SDATA_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->flags & IEEE80211_TXRXD_TX_INJECTED)) + return TXRX_CONTINUE; + + 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->flags & IEEE80211_TXRXD_TXPS_BUFFERED) + return TXRX_CONTINUE; + + sta_flags = tx->sta ? tx->sta->flags : 0; + + if (likely(tx->flags & IEEE80211_TXRXD_TXUNICAST)) { + 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 + DECLARE_MAC_BUF(mac); + printk(KERN_DEBUG "%s: dropped data frame to not " + "associated station %s\n", + tx->dev->name, print_mac(mac, 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->sdata->type != IEEE80211_IF_TYPE_IBSS)) { + /* + * No associated STAs - no need to send multicast + * frames. + */ + return TXRX_DROP; + } + return TXRX_CONTINUE; + } + + if (unlikely(/* !injected && */ tx->sdata->ieee802_1x && + !(sta_flags & WLAN_STA_AUTHORIZED))) { +#ifdef CONFIG_MAC80211_VERBOSE_DEBUG + DECLARE_MAC_BUF(mac); + printk(KERN_DEBUG "%s: dropped frame to %s" + " (unauthorized port)\n", tx->dev->name, + print_mac(mac, 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; + + /* + * virtual interfaces are protected by RCU + */ + rcu_read_lock(); + + list_for_each_entry_rcu(sdata, &local->interfaces, 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); + } + rcu_read_unlock(); + + read_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); + } + read_unlock_bh(&local->sta_lock); + + local->total_ps_buffered = total; + printk(KERN_DEBUG "%s: PS buffers full - purged %d frames\n", + wiphy_name(local->hw.wiphy), 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; + DECLARE_MAC_BUF(mac); + + 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 %s aid %d: PS buffer (entries " + "before %d)\n", + print_mac(mac, 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 %s TX " + "buffer full - dropping oldest frame\n", + tx->dev->name, print_mac(mac, 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 %s in PS mode, but pspoll " + "set -> send frame\n", tx->dev->name, + print_mac(mac, 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->flags & IEEE80211_TXRXD_TXPS_BUFFERED)) + return TXRX_CONTINUE; + + if (tx->flags & IEEE80211_TXRXD_TXUNICAST) + 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) +{ + struct ieee80211_key *key; + + if (unlikely(tx->u.tx.control->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT)) + tx->key = NULL; + else if (tx->sta && (key = rcu_dereference(tx->sta->key))) + tx->key = key; + else if ((key = rcu_dereference(tx->sdata->default_key))) + tx->key = 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; + tx->u.tx.control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT; + } + + if (tx->key) { + tx->key->tx_rx_count++; + /* TODO: add threshold stuff again */ + } + + 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->flags & IEEE80211_TXRXD_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 = DIV_ROUND_UP(payload_len, 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 ieee80211_txrx_result +ieee80211_tx_h_encrypt(struct ieee80211_txrx_data *tx) +{ + if (!tx->key) + return TXRX_CONTINUE; + + switch (tx->key->conf.alg) { + case ALG_WEP: + return ieee80211_crypto_wep_encrypt(tx); + case ALG_TKIP: + return ieee80211_crypto_tkip_encrypt(tx); + case ALG_CCMP: + return ieee80211_crypto_ccmp_encrypt(tx); + } + + /* not reached */ + WARN_ON(1); + return TXRX_DROP; +} + +static ieee80211_txrx_result +ieee80211_tx_h_rate_ctrl(struct ieee80211_txrx_data *tx) +{ + struct rate_control_extra extra; + + if (likely(!tx->u.tx.rate)) { + memset(&extra, 0, sizeof(extra)); + extra.mode = tx->u.tx.mode; + 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->flags |= IEEE80211_TXRXD_TXPROBE_LAST_FRAG; + 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; + } else + tx->u.tx.control->alt_retry_rate = -1; + + if (tx->u.tx.mode->mode == MODE_IEEE80211G && + (tx->sdata->flags & IEEE80211_SDATA_USE_PROTECTION) && + (tx->flags & IEEE80211_TXRXD_FRAGMENTED) && extra.nonerp) { + tx->u.tx.last_frag_rate = tx->u.tx.rate; + if (extra.probe) + tx->flags &= ~IEEE80211_TXRXD_TXPROBE_LAST_FRAG; + else + tx->flags |= IEEE80211_TXRXD_TXPROBE_LAST_FRAG; + 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; + + 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 fc = le16_to_cpu(hdr->frame_control); + u16 dur; + struct ieee80211_tx_control *control = tx->u.tx.control; + struct ieee80211_hw_mode *mode = tx->u.tx.mode; + + if (!control->retry_limit) { + 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->flags |= + IEEE80211_TXCTL_LONG_RETRY_LIMIT; + control->retry_limit = + tx->local->long_retry_limit; + } else { + control->retry_limit = + tx->local->short_retry_limit; + } + } else { + control->retry_limit = 1; + } + } + + if (tx->flags & IEEE80211_TXRXD_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->flags & IEEE80211_TXRXD_TXUNICAST) && + (tx->sdata->flags & IEEE80211_SDATA_USE_PROTECTION) && + !(control->flags & IEEE80211_TXCTL_USE_RTS_CTS)) + control->flags |= IEEE80211_TXCTL_USE_CTS_PROTECT; + + /* Transmit data frames using short preambles if the driver supports + * short preambles at the selected rate and short preambles are + * available on the network at the current point in time. */ + if (((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) && + (tx->u.tx.rate->flags & IEEE80211_RATE_PREAMBLE2) && + (tx->sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE) && + (!tx->sta || (tx->sta->flags & WLAN_STA_SHORT_PREAMBLE))) { + tx->u.tx.control->tx_rate = tx->u.tx.rate->val2; + } + + /* 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->flags & IEEE80211_TXRXD_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; + } + } + } + + /* + * Tell hardware to not encrypt when we had sw crypto. + * Because we use the same flag to internally indicate that + * no (software) encryption should be done, we have to set it + * after all crypto handlers. + */ + if (tx->key && !(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) + tx->u.tx.control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT; + + 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_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_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) +{ + /* + * 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); + struct ieee80211_tx_control *control = tx->u.tx.control; + + control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT; + tx->flags |= IEEE80211_TXRXD_TX_INJECTED; + tx->flags &= ~IEEE80211_TXRXD_FRAGMENTED; + + /* + * 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) { + tx->u.tx.rate = r; + break; + } + } + 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); + } + if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP) + control->flags &= + ~IEEE80211_TXCTL_DO_NOT_ENCRYPT; + if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG) + tx->flags |= IEEE80211_TXRXD_FRAGMENTED; + break; + + /* + * Please update the file + * Documentation/networking/mac80211-injection.txt + * when parsing new fields here. + */ + + 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; +} + +/* + * initialises @tx + */ +static ieee80211_txrx_result +__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_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->u.tx.control = control; + /* + * Set this flag (used below to indicate "automatic fragmentation"), + * it will be cleared/left by radiotap as desired. + */ + tx->flags |= IEEE80211_TXRXD_FRAGMENTED; + + /* 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) == TXRX_DROP) + return TXRX_DROP; + + /* + * __ieee80211_parse_tx_radiotap has now removed + * the radiotap header that was present and pre-filled + * 'tx' with tx control information. + */ + } + + hdr = (struct ieee80211_hdr *) skb->data; + + tx->sta = sta_info_get(local, hdr->addr1); + tx->fc = le16_to_cpu(hdr->frame_control); + + if (is_multicast_ether_addr(hdr->addr1)) { + tx->flags &= ~IEEE80211_TXRXD_TXUNICAST; + control->flags |= IEEE80211_TXCTL_NO_ACK; + } else { + tx->flags |= IEEE80211_TXRXD_TXUNICAST; + control->flags &= ~IEEE80211_TXCTL_NO_ACK; + } + + if (tx->flags & IEEE80211_TXRXD_FRAGMENTED) { + if ((tx->flags & IEEE80211_TXRXD_TXUNICAST) && + skb->len + FCS_LEN > local->fragmentation_threshold && + !local->ops->set_frag_threshold) + tx->flags |= IEEE80211_TXRXD_FRAGMENTED; + else + tx->flags &= ~IEEE80211_TXRXD_FRAGMENTED; + } + + 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. + * + * NB: @tx is uninitialised when passed in here + */ +static int 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(&init_net, pkt_data->ifindex); + if (unlikely(dev && !is_ieee80211_device(dev, mdev))) { + dev_put(dev); + dev = NULL; + } + if (unlikely(!dev)) + return -ENODEV; + /* initialises tx with control */ + __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(wiphy_name(local->hw.wiphy), + "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->flags & IEEE80211_TXRXD_TXPROBE_LAST_FRAG) + control->flags |= + IEEE80211_TXCTL_RATE_CTRL_PROBE; + else + control->flags &= + ~IEEE80211_TXCTL_RATE_CTRL_PROBE; + } + + ieee80211_dump_frame(wiphy_name(local->hw.wiphy), + "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) +{ + 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; + } + + /* initialises tx */ + res_prepare = __ieee80211_tx_prepare(&tx, skb, dev, control); + + if (res_prepare == TXRX_DROP) { + dev_kfree_skb(skb); + return 0; + } + + /* + * key references are protected using RCU and this requires that + * we are in a read-site RCU section during receive processing + */ + rcu_read_lock(); + + sta = tx.sta; + tx.u.tx.mode = local->hw.conf.mode; + + 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); + rcu_read_unlock(); + 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.flags & IEEE80211_TXRXD_TXPROBE_LAST_FRAG); + } + rcu_read_unlock(); + 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); + rcu_read_unlock(); + 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(&init_net, 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->flags & IEEE80211_TXPD_REQ_TX_STATUS) + control.flags |= IEEE80211_TXCTL_REQ_TX_STATUS; + if (pkt_data->flags & IEEE80211_TXPD_DO_NOT_ENCRYPT) + control.flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT; + if (pkt_data->flags & IEEE80211_TXPD_REQUEUE) + control.flags |= IEEE80211_TXCTL_REQUEUE; + control.queue = pkt_data->queue; + + ret = ieee80211_tx(odev, skb, &control); + 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_rthdr; + + /* check for not even having the fixed radiotap header part */ + if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header))) + goto fail; /* too short to be possibly valid */ + + /* is it a header version we can trust to find length from? */ + if (unlikely(prthdr->it_version)) + goto fail; /* only version 0 is supported */ + + /* then there must be a radiotap header with a length we can use */ + len_rthdr = ieee80211_get_radiotap_len(skb->data); + + /* does the skb contain enough to deliver on the alleged length? */ + if (unlikely(skb->len < len_rthdr)) + goto fail; /* skb too short for claimed rt header extent */ + + skb->dev = local->mdev; + + pkt_data = (struct ieee80211_tx_packet_data *)skb->cb; + memset(pkt_data, 0, sizeof(*pkt_data)); + /* needed because we set skb device to master */ + pkt_data->ifindex = dev->ifindex; + + pkt_data->flags |= IEEE80211_TXPD_DO_NOT_ENCRYPT; + + /* + * 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 + */ + skb_set_mac_header(skb, len_rthdr); + /* + * these are just fixed to the end of the rt area since we + * don't have any better information and at this point, nobody cares + */ + skb_set_network_header(skb, len_rthdr); + skb_set_transport_header(skb, len_rthdr); + + /* pass the radiotap header up to the next stage intact */ + dev_queue_xmit(skb); + return NETDEV_TX_OK; + +fail: + dev_kfree_skb(skb); + return NETDEV_TX_OK; /* meaning, we dealt with the skb */ +} + +/** + * 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; + 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; + + switch (sdata->type) { + case IEEE80211_IF_TYPE_AP: + case 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; + break; + case 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; + break; + case 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; + break; + case 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; + break; + default: + 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; + } + + if (fc & IEEE80211_STYPE_QOS_DATA) { + __le16 *qos_control; + + qos_control = (__le16*) skb_push(skb, 2); + memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2); + /* + * Maybe we could actually set some fields here, for now just + * initialise to zero to indicate no special operation. + */ + *qos_control = 0; + } else + 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; + + skb->dev = local->mdev; + dev->stats.tx_packets++; + dev->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; + + 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->flags |= IEEE80211_TXPD_REQ_TX_STATUS; + fc &= ~BIT(1); + hdr->frame_control = cpu_to_le16(fc); + } + + if (!(fc & IEEE80211_FCTL_PROTECTED)) + pkt_data->flags |= IEEE80211_TXPD_DO_NOT_ENCRYPT; + + dev->stats.tx_packets++; + dev->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.flags = 0; + if (store->last_frag_rate_ctrl_probe) + tx.flags |= IEEE80211_TXRXD_TXPROBE_LAST_FRAG; + 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. */ + read_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 */ + } + read_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(&init_net, 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", wiphy_name(local->hw.wiphy)); + } + dev_kfree_skb(skb); + return NULL; + } + + control->tx_rate = + ((sdata->flags & IEEE80211_SDATA_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, int if_id, + 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, if_id, 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, int if_id, + 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, if_id, 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(&init_net, 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)) + break; + dev_kfree_skb_any(skb); + } + sta = tx.sta; + tx.flags |= IEEE80211_TXRXD_TXPS_BUFFERED; + tx.u.tx.mode = local->hw.conf.mode; + + 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); |
