/* * Copyright 2002-2005, Instant802 Networks, Inc. * Copyright 2005-2006, Devicescape Software, Inc. * Copyright 2006-2007 Jiri Benc * Copyright 2007 Johannes Berg * * 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 #include #include #include #include #include #include #include #include #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, tx->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->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); 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", 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; 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 (!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->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; /* 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->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->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. */ 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(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 = (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(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);