ieee80211.c

linux 内核源代码

/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <[e-mail]>
 *
 * 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.
 */

#include <net/mac80211.h>
#include <net/ieee80211_radiotap.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/wireless.h>
#include <linux/rtnetlink.h>
#include <linux/bitmap.h>
#include <net/net_namespace.h>
#include <net/cfg80211.h>

#include "ieee80211_i.h"
#include "ieee80211_rate.h"
#include "wep.h"
#include "wme.h"
#include "aes_ccm.h"
#include "ieee80211_led.h"
#include "cfg.h"
#include "debugfs.h"
#include "debugfs_netdev.h"

/*
 * For seeing transmitted packets on monitor interfaces
 * we have a radiotap header too.
 */
struct ieee80211_tx_status_rtap_hdr {
	struct ieee80211_radiotap_header hdr;
	__le16 tx_flags;
	u8 data_retries;
} __attribute__ ((packed));

/* common interface routines */

static int header_parse_80211(const struct sk_buff *skb, unsigned char *haddr)
{
	memcpy(haddr, skb_mac_header(skb) + 10, ETH_ALEN); /* addr2 */
	return ETH_ALEN;
}

/* must be called under mdev tx lock */
static void ieee80211_configure_filter(struct ieee80211_local *local)
{
	unsigned int changed_flags;
	unsigned int new_flags = 0;

	if (atomic_read(&local->iff_promiscs))
		new_flags |= FIF_PROMISC_IN_BSS;

	if (atomic_read(&local->iff_allmultis))
		new_flags |= FIF_ALLMULTI;

	if (local->monitors)
		new_flags |= FIF_CONTROL |
			     FIF_OTHER_BSS |
			     FIF_BCN_PRBRESP_PROMISC;

	changed_flags = local->filter_flags ^ new_flags;

	/* be a bit nasty */
	new_flags |= (1<<31);

	local->ops->configure_filter(local_to_hw(local),
				     changed_flags, &new_flags,
				     local->mdev->mc_count,
				     local->mdev->mc_list);

	WARN_ON(new_flags & (1<<31));

	local->filter_flags = new_flags & ~(1<<31);
}

/* master interface */

static int ieee80211_master_open(struct net_device *dev)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_sub_if_data *sdata;
	int res = -EOPNOTSUPP;

	/* we hold the RTNL here so can safely walk the list */
	list_for_each_entry(sdata, &local->interfaces, list) {
		if (sdata->dev != dev && netif_running(sdata->dev)) {
			res = 0;
			break;
		}
	}
	return res;
}

static int ieee80211_master_stop(struct net_device *dev)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_sub_if_data *sdata;

	/* we hold the RTNL here so can safely walk the list */
	list_for_each_entry(sdata, &local->interfaces, list)
		if (sdata->dev != dev && netif_running(sdata->dev))
			dev_close(sdata->dev);

	return 0;
}

static void ieee80211_master_set_multicast_list(struct net_device *dev)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);

	ieee80211_configure_filter(local);
}

/* regular interfaces */

static int ieee80211_change_mtu(struct net_device *dev, int new_mtu)
{
	/* FIX: what would be proper limits for MTU?
	 * This interface uses 802.3 frames. */
	if (new_mtu < 256 || new_mtu > IEEE80211_MAX_DATA_LEN - 24 - 6) {
		printk(KERN_WARNING "%s: invalid MTU %d\n",
		       dev->name, new_mtu);
		return -EINVAL;
	}

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
	printk(KERN_DEBUG "%s: setting MTU %d\n", dev->name, new_mtu);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
	dev->mtu = new_mtu;
	return 0;
}

static inline int identical_mac_addr_allowed(int type1, int type2)
{
	return (type1 == IEEE80211_IF_TYPE_MNTR ||
		type2 == IEEE80211_IF_TYPE_MNTR ||
		(type1 == IEEE80211_IF_TYPE_AP &&
		 type2 == IEEE80211_IF_TYPE_WDS) ||
		(type1 == IEEE80211_IF_TYPE_WDS &&
		 (type2 == IEEE80211_IF_TYPE_WDS ||
		  type2 == IEEE80211_IF_TYPE_AP)) ||
		(type1 == IEEE80211_IF_TYPE_AP &&
		 type2 == IEEE80211_IF_TYPE_VLAN) ||
		(type1 == IEEE80211_IF_TYPE_VLAN &&
		 (type2 == IEEE80211_IF_TYPE_AP ||
		  type2 == IEEE80211_IF_TYPE_VLAN)));
}

static int ieee80211_open(struct net_device *dev)
{
	struct ieee80211_sub_if_data *sdata, *nsdata;
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_if_init_conf conf;
	int res;

	sdata = IEEE80211_DEV_TO_SUB_IF(dev);

	/* we hold the RTNL here so can safely walk the list */
	list_for_each_entry(nsdata, &local->interfaces, list) {
		struct net_device *ndev = nsdata->dev;

		if (ndev != dev && ndev != local->mdev && netif_running(ndev) &&
		    compare_ether_addr(dev->dev_addr, ndev->dev_addr) == 0) {
			/*
			 * check whether it may have the same address
			 */
			if (!identical_mac_addr_allowed(sdata->type,
							nsdata->type))
				return -ENOTUNIQ;

			/*
			 * can only add VLANs to enabled APs
			 */
			if (sdata->type == IEEE80211_IF_TYPE_VLAN &&
			    nsdata->type == IEEE80211_IF_TYPE_AP &&
			    netif_running(nsdata->dev))
				sdata->u.vlan.ap = nsdata;
		}
	}

	switch (sdata->type) {
	case IEEE80211_IF_TYPE_WDS:
		if (is_zero_ether_addr(sdata->u.wds.remote_addr))
			return -ENOLINK;
		break;
	case IEEE80211_IF_TYPE_VLAN:
		if (!sdata->u.vlan.ap)
			return -ENOLINK;
		break;
	case IEEE80211_IF_TYPE_AP:
	case IEEE80211_IF_TYPE_STA:
	case IEEE80211_IF_TYPE_MNTR:
	case IEEE80211_IF_TYPE_IBSS:
		/* no special treatment */
		break;
	case IEEE80211_IF_TYPE_INVALID:
		/* cannot happen */
		WARN_ON(1);
		break;
	}

	if (local->open_count == 0) {
		res = 0;
		if (local->ops->start)
			res = local->ops->start(local_to_hw(local));
		if (res)
			return res;
		ieee80211_hw_config(local);
	}

	switch (sdata->type) {
	case IEEE80211_IF_TYPE_VLAN:
		list_add(&sdata->u.vlan.list, &sdata->u.vlan.ap->u.ap.vlans);
		/* no need to tell driver */
		break;
	case IEEE80211_IF_TYPE_MNTR:
		/* must be before the call to ieee80211_configure_filter */
		local->monitors++;
		if (local->monitors == 1) {
			netif_tx_lock_bh(local->mdev);
			ieee80211_configure_filter(local);
			netif_tx_unlock_bh(local->mdev);

			local->hw.conf.flags |= IEEE80211_CONF_RADIOTAP;
		}
		break;
	case IEEE80211_IF_TYPE_STA:
	case IEEE80211_IF_TYPE_IBSS:
		sdata->u.sta.flags &= ~IEEE80211_STA_PREV_BSSID_SET;
		/* fall through */
	default:
		conf.if_id = dev->ifindex;
		conf.type = sdata->type;
		conf.mac_addr = dev->dev_addr;
		res = local->ops->add_interface(local_to_hw(local), &conf);
		if (res && !local->open_count && local->ops->stop)
			local->ops->stop(local_to_hw(local));
		if (res)
			return res;

		ieee80211_if_config(dev);
		ieee80211_reset_erp_info(dev);
		ieee80211_enable_keys(sdata);

		if (sdata->type == IEEE80211_IF_TYPE_STA &&
		    !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME))
			netif_carrier_off(dev);
		else
			netif_carrier_on(dev);
	}

	if (local->open_count == 0) {
		res = dev_open(local->mdev);
		WARN_ON(res);
		tasklet_enable(&local->tx_pending_tasklet);
		tasklet_enable(&local->tasklet);
	}

	/*
	 * set_multicast_list will be invoked by the networking core
	 * which will check whether any increments here were done in
	 * error and sync them down to the hardware as filter flags.
	 */
	if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
		atomic_inc(&local->iff_allmultis);

	if (sdata->flags & IEEE80211_SDATA_PROMISC)
		atomic_inc(&local->iff_promiscs);

	local->open_count++;

	netif_start_queue(dev);

	return 0;
}

static int ieee80211_stop(struct net_device *dev)
{
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_if_init_conf conf;

	sdata = IEEE80211_DEV_TO_SUB_IF(dev);

	netif_stop_queue(dev);

	/*
	 * Don't count this interface for promisc/allmulti while it
	 * is down. dev_mc_unsync() will invoke set_multicast_list
	 * on the master interface which will sync these down to the
	 * hardware as filter flags.
	 */
	if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
		atomic_dec(&local->iff_allmultis);

	if (sdata->flags & IEEE80211_SDATA_PROMISC)
		atomic_dec(&local->iff_promiscs);

	dev_mc_unsync(local->mdev, dev);

	/* down all dependent devices, that is VLANs */
	if (sdata->type == IEEE80211_IF_TYPE_AP) {
		struct ieee80211_sub_if_data *vlan, *tmp;

		list_for_each_entry_safe(vlan, tmp, &sdata->u.ap.vlans,
					 u.vlan.list)
			dev_close(vlan->dev);
		WARN_ON(!list_empty(&sdata->u.ap.vlans));
	}

	local->open_count--;

	switch (sdata->type) {
	case IEEE80211_IF_TYPE_VLAN:
		list_del(&sdata->u.vlan.list);
		sdata->u.vlan.ap = NULL;
		/* no need to tell driver */
		break;
	case IEEE80211_IF_TYPE_MNTR:
		local->monitors--;
		if (local->monitors == 0) {
			netif_tx_lock_bh(local->mdev);
			ieee80211_configure_filter(local);
			netif_tx_unlock_bh(local->mdev);

			local->hw.conf.flags &= ~IEEE80211_CONF_RADIOTAP;
		}
		break;
	case IEEE80211_IF_TYPE_STA:
	case IEEE80211_IF_TYPE_IBSS:
		sdata->u.sta.state = IEEE80211_DISABLED;
		del_timer_sync(&sdata->u.sta.timer);
		/*
		 * When we get here, the interface is marked down.
		 * Call synchronize_rcu() to wait for the RX path
		 * should it be using the interface and enqueuing
		 * frames at this very time on another CPU.
		 */
		synchronize_rcu();
		skb_queue_purge(&sdata->u.sta.skb_queue);

		if (!local->ops->hw_scan &&
		    local->scan_dev == sdata->dev) {
			local->sta_scanning = 0;
			cancel_delayed_work(&local->scan_work);
		}
		flush_workqueue(local->hw.workqueue);

		sdata->u.sta.flags &= ~IEEE80211_STA_PRIVACY_INVOKED;
		kfree(sdata->u.sta.extra_ie);
		sdata->u.sta.extra_ie = NULL;
		sdata->u.sta.extra_ie_len = 0;
		/* fall through */
	default:
		conf.if_id = dev->ifindex;
		conf.type = sdata->type;
		conf.mac_addr = dev->dev_addr;
		/* disable all keys for as long as this netdev is down */
		ieee80211_disable_keys(sdata);
		local->ops->remove_interface(local_to_hw(local), &conf);
	}

	if (local->open_count == 0) {
		if (netif_running(local->mdev))
			dev_close(local->mdev);

		if (local->ops->stop)
			local->ops->stop(local_to_hw(local));

		tasklet_disable(&local->tx_pending_tasklet);
		tasklet_disable(&local->tasklet);
	}

	return 0;
}

static void ieee80211_set_multicast_list(struct net_device *dev)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	int allmulti, promisc, sdata_allmulti, sdata_promisc;

	allmulti = !!(dev->flags & IFF_ALLMULTI);
	promisc = !!(dev->flags & IFF_PROMISC);
	sdata_allmulti = !!(sdata->flags & IEEE80211_SDATA_ALLMULTI);
	sdata_promisc = !!(sdata->flags & IEEE80211_SDATA_PROMISC);

	if (allmulti != sdata_allmulti) {
		if (dev->flags & IFF_ALLMULTI)
			atomic_inc(&local->iff_allmultis);
		else
			atomic_dec(&local->iff_allmultis);
		sdata->flags ^= IEEE80211_SDATA_ALLMULTI;
	}

	if (promisc != sdata_promisc) {
		if (dev->flags & IFF_PROMISC)
			atomic_inc(&local->iff_promiscs);
		else
			atomic_dec(&local->iff_promiscs);
		sdata->flags ^= IEEE80211_SDATA_PROMISC;
	}

	dev_mc_sync(local->mdev, dev);
}

static const struct header_ops ieee80211_header_ops = {
	.create		= eth_header,
	.parse		= header_parse_80211,
	.rebuild	= eth_rebuild_header,
	.cache		= eth_header_cache,
	.cache_update	= eth_header_cache_update,
};

/* Must not be called for mdev */
void ieee80211_if_setup(struct net_device *dev)
{
	ether_setup(dev);
	dev->hard_start_xmit = ieee80211_subif_start_xmit;
	dev->wireless_handlers = &ieee80211_iw_handler_def;
	dev->set_multicast_list = ieee80211_set_multicast_list;
	dev->change_mtu = ieee80211_change_mtu;
	dev->open = ieee80211_open;