ieee80211.c

linux 内核源代码

	dev->stop = ieee80211_stop;
	dev->destructor = ieee80211_if_free;
}

/* WDS specialties */

int ieee80211_if_update_wds(struct net_device *dev, u8 *remote_addr)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	struct sta_info *sta;
	DECLARE_MAC_BUF(mac);

	if (compare_ether_addr(remote_addr, sdata->u.wds.remote_addr) == 0)
		return 0;

	/* Create STA entry for the new peer */
	sta = sta_info_add(local, dev, remote_addr, GFP_KERNEL);
	if (!sta)
		return -ENOMEM;
	sta_info_put(sta);

	/* Remove STA entry for the old peer */
	sta = sta_info_get(local, sdata->u.wds.remote_addr);
	if (sta) {
		sta_info_free(sta);
		sta_info_put(sta);
	} else {
		printk(KERN_DEBUG "%s: could not find STA entry for WDS link "
		       "peer %s\n",
		       dev->name, print_mac(mac, sdata->u.wds.remote_addr));
	}

	/* Update WDS link data */
	memcpy(&sdata->u.wds.remote_addr, remote_addr, ETH_ALEN);

	return 0;
}

/* everything else */

static int __ieee80211_if_config(struct net_device *dev,
				 struct sk_buff *beacon,
				 struct ieee80211_tx_control *control)
{
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_if_conf conf;

	if (!local->ops->config_interface || !netif_running(dev))
		return 0;

	memset(&conf, 0, sizeof(conf));
	conf.type = sdata->type;
	if (sdata->type == IEEE80211_IF_TYPE_STA ||
	    sdata->type == IEEE80211_IF_TYPE_IBSS) {
		conf.bssid = sdata->u.sta.bssid;
		conf.ssid = sdata->u.sta.ssid;
		conf.ssid_len = sdata->u.sta.ssid_len;
	} else if (sdata->type == IEEE80211_IF_TYPE_AP) {
		conf.ssid = sdata->u.ap.ssid;
		conf.ssid_len = sdata->u.ap.ssid_len;
		conf.beacon = beacon;
		conf.beacon_control = control;
	}
	return local->ops->config_interface(local_to_hw(local),
					   dev->ifindex, &conf);
}

int ieee80211_if_config(struct net_device *dev)
{
	return __ieee80211_if_config(dev, NULL, NULL);
}

int ieee80211_if_config_beacon(struct net_device *dev)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_tx_control control;
	struct sk_buff *skb;

	if (!(local->hw.flags & IEEE80211_HW_HOST_GEN_BEACON_TEMPLATE))
		return 0;
	skb = ieee80211_beacon_get(local_to_hw(local), dev->ifindex, &control);
	if (!skb)
		return -ENOMEM;
	return __ieee80211_if_config(dev, skb, &control);
}

int ieee80211_hw_config(struct ieee80211_local *local)
{
	struct ieee80211_hw_mode *mode;
	struct ieee80211_channel *chan;
	int ret = 0;

	if (local->sta_scanning) {
		chan = local->scan_channel;
		mode = local->scan_hw_mode;
	} else {
		chan = local->oper_channel;
		mode = local->oper_hw_mode;
	}

	local->hw.conf.channel = chan->chan;
	local->hw.conf.channel_val = chan->val;
	if (!local->hw.conf.power_level) {
		local->hw.conf.power_level = chan->power_level;
	} else {
		local->hw.conf.power_level = min(chan->power_level,
						 local->hw.conf.power_level);
	}
	local->hw.conf.freq = chan->freq;
	local->hw.conf.phymode = mode->mode;
	local->hw.conf.antenna_max = chan->antenna_max;
	local->hw.conf.chan = chan;
	local->hw.conf.mode = mode;

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
	printk(KERN_DEBUG "HW CONFIG: channel=%d freq=%d "
	       "phymode=%d\n", local->hw.conf.channel, local->hw.conf.freq,
	       local->hw.conf.phymode);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */

	if (local->open_count)
		ret = local->ops->config(local_to_hw(local), &local->hw.conf);

	return ret;
}

void ieee80211_erp_info_change_notify(struct net_device *dev, u8 changes)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	if (local->ops->erp_ie_changed)
		local->ops->erp_ie_changed(local_to_hw(local), changes,
			!!(sdata->flags & IEEE80211_SDATA_USE_PROTECTION),
			!(sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE));
}

void ieee80211_reset_erp_info(struct net_device *dev)
{
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

	sdata->flags &= ~(IEEE80211_SDATA_USE_PROTECTION |
			IEEE80211_SDATA_SHORT_PREAMBLE);
	ieee80211_erp_info_change_notify(dev,
					 IEEE80211_ERP_CHANGE_PROTECTION |
					 IEEE80211_ERP_CHANGE_PREAMBLE);
}

void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
				 struct sk_buff *skb,
				 struct ieee80211_tx_status *status)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_tx_status *saved;
	int tmp;

	skb->dev = local->mdev;
	saved = kmalloc(sizeof(struct ieee80211_tx_status), GFP_ATOMIC);
	if (unlikely(!saved)) {
		if (net_ratelimit())
			printk(KERN_WARNING "%s: Not enough memory, "
			       "dropping tx status", skb->dev->name);
		/* should be dev_kfree_skb_irq, but due to this function being
		 * named _irqsafe instead of just _irq we can't be sure that
		 * people won't call it from non-irq contexts */
		dev_kfree_skb_any(skb);
		return;
	}
	memcpy(saved, status, sizeof(struct ieee80211_tx_status));
	/* copy pointer to saved status into skb->cb for use by tasklet */
	memcpy(skb->cb, &saved, sizeof(saved));

	skb->pkt_type = IEEE80211_TX_STATUS_MSG;
	skb_queue_tail(status->control.flags & IEEE80211_TXCTL_REQ_TX_STATUS ?
		       &local->skb_queue : &local->skb_queue_unreliable, skb);
	tmp = skb_queue_len(&local->skb_queue) +
		skb_queue_len(&local->skb_queue_unreliable);
	while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
	       (skb = skb_dequeue(&local->skb_queue_unreliable))) {
		memcpy(&saved, skb->cb, sizeof(saved));
		kfree(saved);
		dev_kfree_skb_irq(skb);
		tmp--;
		I802_DEBUG_INC(local->tx_status_drop);
	}
	tasklet_schedule(&local->tasklet);
}
EXPORT_SYMBOL(ieee80211_tx_status_irqsafe);

static void ieee80211_tasklet_handler(unsigned long data)
{
	struct ieee80211_local *local = (struct ieee80211_local *) data;
	struct sk_buff *skb;
	struct ieee80211_rx_status rx_status;
	struct ieee80211_tx_status *tx_status;

	while ((skb = skb_dequeue(&local->skb_queue)) ||
	       (skb = skb_dequeue(&local->skb_queue_unreliable))) {
		switch (skb->pkt_type) {
		case IEEE80211_RX_MSG:
			/* status is in skb->cb */
			memcpy(&rx_status, skb->cb, sizeof(rx_status));
			/* Clear skb->type in order to not confuse kernel
			 * netstack. */
			skb->pkt_type = 0;
			__ieee80211_rx(local_to_hw(local), skb, &rx_status);
			break;
		case IEEE80211_TX_STATUS_MSG:
			/* get pointer to saved status out of skb->cb */
			memcpy(&tx_status, skb->cb, sizeof(tx_status));
			skb->pkt_type = 0;
			ieee80211_tx_status(local_to_hw(local),
					    skb, tx_status);
			kfree(tx_status);
			break;
		default: /* should never get here! */
			printk(KERN_ERR "%s: Unknown message type (%d)\n",
			       wiphy_name(local->hw.wiphy), skb->pkt_type);
			dev_kfree_skb(skb);
			break;
		}
	}
}

/* Remove added headers (e.g., QoS control), encryption header/MIC, etc. to
 * make a prepared TX frame (one that has been given to hw) to look like brand
 * new IEEE 802.11 frame that is ready to go through TX processing again.
 * Also, tx_packet_data in cb is restored from tx_control. */
static void ieee80211_remove_tx_extra(struct ieee80211_local *local,
				      struct ieee80211_key *key,
				      struct sk_buff *skb,
				      struct ieee80211_tx_control *control)
{
	int hdrlen, iv_len, mic_len;
	struct ieee80211_tx_packet_data *pkt_data;

	pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
	pkt_data->ifindex = control->ifindex;
	pkt_data->flags = 0;
	if (control->flags & IEEE80211_TXCTL_REQ_TX_STATUS)
		pkt_data->flags |= IEEE80211_TXPD_REQ_TX_STATUS;
	if (control->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT)
		pkt_data->flags |= IEEE80211_TXPD_DO_NOT_ENCRYPT;
	if (control->flags & IEEE80211_TXCTL_REQUEUE)
		pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
	pkt_data->queue = control->queue;

	hdrlen = ieee80211_get_hdrlen_from_skb(skb);

	if (!key)
		goto no_key;

	switch (key->conf.alg) {
	case ALG_WEP:
		iv_len = WEP_IV_LEN;
		mic_len = WEP_ICV_LEN;
		break;
	case ALG_TKIP:
		iv_len = TKIP_IV_LEN;
		mic_len = TKIP_ICV_LEN;
		break;
	case ALG_CCMP:
		iv_len = CCMP_HDR_LEN;
		mic_len = CCMP_MIC_LEN;
		break;
	default:
		goto no_key;
	}

	if (skb->len >= mic_len &&
	    !(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
		skb_trim(skb, skb->len - mic_len);
	if (skb->len >= iv_len && skb->len > hdrlen) {
		memmove(skb->data + iv_len, skb->data, hdrlen);
		skb_pull(skb, iv_len);
	}

no_key:
	{
		struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
		u16 fc = le16_to_cpu(hdr->frame_control);
		if ((fc & 0x8C) == 0x88) /* QoS Control Field */ {
			fc &= ~IEEE80211_STYPE_QOS_DATA;
			hdr->frame_control = cpu_to_le16(fc);
			memmove(skb->data + 2, skb->data, hdrlen - 2);
			skb_pull(skb, 2);
		}
	}
}

void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb,
			 struct ieee80211_tx_status *status)
{
	struct sk_buff *skb2;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	struct ieee80211_local *local = hw_to_local(hw);
	u16 frag, type;
	struct ieee80211_tx_status_rtap_hdr *rthdr;
	struct ieee80211_sub_if_data *sdata;
	int monitors;

	if (!status) {
		printk(KERN_ERR
		       "%s: ieee80211_tx_status called with NULL status\n",
		       wiphy_name(local->hw.wiphy));
		dev_kfree_skb(skb);
		return;
	}

	if (status->excessive_retries) {
		struct sta_info *sta;
		sta = sta_info_get(local, hdr->addr1);
		if (sta) {
			if (sta->flags & WLAN_STA_PS) {
				/* The STA is in power save mode, so assume
				 * that this TX packet failed because of that.
				 */
				status->excessive_retries = 0;
				status->flags |= IEEE80211_TX_STATUS_TX_FILTERED;
			}
			sta_info_put(sta);
		}
	}

	if (status->flags & IEEE80211_TX_STATUS_TX_FILTERED) {
		struct sta_info *sta;
		sta = sta_info_get(local, hdr->addr1);
		if (sta) {
			sta->tx_filtered_count++;

			/* Clear the TX filter mask for this STA when sending
			 * the next packet. If the STA went to power save mode,
			 * this will happen when it is waking up for the next
			 * time. */
			sta->clear_dst_mask = 1;

			/* TODO: Is the WLAN_STA_PS flag always set here or is
			 * the race between RX and TX status causing some
			 * packets to be filtered out before 80211.o gets an
			 * update for PS status? This seems to be the case, so
			 * no changes are likely to be needed. */
			if (sta->flags & WLAN_STA_PS &&
			    skb_queue_len(&sta->tx_filtered) <
			    STA_MAX_TX_BUFFER) {
				ieee80211_remove_tx_extra(local, sta->key,
							  skb,
							  &status->control);
				skb_queue_tail(&sta->tx_filtered, skb);
			} else if (!(sta->flags & WLAN_STA_PS) &&
				   !(status->control.flags & IEEE80211_TXCTL_REQUEUE)) {
				/* Software retry the packet once */
				status->control.flags |= IEEE80211_TXCTL_REQUEUE;
				ieee80211_remove_tx_extra(local, sta->key,
							  skb,
							  &status->control);
				dev_queue_xmit(skb);
			} else {
				if (net_ratelimit()) {
					printk(KERN_DEBUG "%s: dropped TX "
					       "filtered frame queue_len=%d "
					       "PS=%d @%lu\n",
					       wiphy_name(local->hw.wiphy),
					       skb_queue_len(
						       &sta->tx_filtered),
					       !!(sta->flags & WLAN_STA_PS),
					       jiffies);
				}
				dev_kfree_skb(skb);
			}
			sta_info_put(sta);
			return;
		}
	} else {
		/* FIXME: STUPID to call this with both local and local->mdev */
		rate_control_tx_status(local, local->mdev, skb, status);
	}

	ieee80211_led_tx(local, 0);

	/* SNMP counters
	 * Fragments are passed to low-level drivers as separate skbs, so these
	 * are actually fragments, not frames. Update frame counters only for
	 * the first fragment of the frame. */

	frag = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG;
	type = le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_FTYPE;

	if (status->flags & IEEE80211_TX_STATUS_ACK) {
		if (frag == 0) {
			local->dot11TransmittedFrameCount++;
			if (is_multicast_ether_addr(hdr->addr1))
				local->dot11MulticastTransmittedFrameCount++;
			if (status->retry_count > 0)
				local->dot11RetryCount++;
			if (status->retry_count > 1)
				local->dot11MultipleRetryCount++;
		}

		/* This counter shall be incremented for an acknowledged MPDU
		 * with an individual address in the address 1 field or an MPDU
		 * with a multicast address in the address 1 field of type Data
		 * or Management. */
		if (!is_multicast_ether_addr(hdr->addr1) ||
		    type == IEEE80211_FTYPE_DATA ||
		    type == IEEE80211_FTYPE_MGMT)
			local->dot11TransmittedFragmentCount++;
	} else {
		if (frag == 0)
			local->dot11FailedCount++;
	}

	/* this was a transmitted frame, but now we want to reuse it */
	skb_orphan(skb);

	if (!local->monitors) {
		dev_kfree_skb(skb);
		return;
	}

	/* send frame to monitor interfaces now */

	if (skb_headroom(skb) < sizeof(*rthdr)) {
		printk(KERN_ERR "ieee80211_tx_status: headroom too small\n");
		dev_kfree_skb(skb);
		return;
	}

	rthdr = (struct ieee80211_tx_status_rtap_hdr*)
				skb_push(skb, sizeof(*rthdr));

	memset(rthdr, 0, sizeof(*rthdr));
	rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
	rthdr->hdr.it_present =