ieee80211_sta.c

linux 内核源代码

	struct ieee80211_mgmt *mgmt;

	skb = dev_alloc_skb(local->hw.extra_tx_headroom +
			    sizeof(*mgmt) + 6 + extra_len);
	if (!skb) {
		printk(KERN_DEBUG "%s: failed to allocate buffer for auth "
		       "frame\n", dev->name);
		return;
	}
	skb_reserve(skb, local->hw.extra_tx_headroom);

	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24 + 6);
	memset(mgmt, 0, 24 + 6);
	mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT,
					   IEEE80211_STYPE_AUTH);
	if (encrypt)
		mgmt->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
	memcpy(mgmt->da, ifsta->bssid, ETH_ALEN);
	memcpy(mgmt->sa, dev->dev_addr, ETH_ALEN);
	memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
	mgmt->u.auth.auth_alg = cpu_to_le16(ifsta->auth_alg);
	mgmt->u.auth.auth_transaction = cpu_to_le16(transaction);
	ifsta->auth_transaction = transaction + 1;
	mgmt->u.auth.status_code = cpu_to_le16(0);
	if (extra)
		memcpy(skb_put(skb, extra_len), extra, extra_len);

	ieee80211_sta_tx(dev, skb, encrypt);
}


static void ieee80211_authenticate(struct net_device *dev,
				   struct ieee80211_if_sta *ifsta)
{
	DECLARE_MAC_BUF(mac);

	ifsta->auth_tries++;
	if (ifsta->auth_tries > IEEE80211_AUTH_MAX_TRIES) {
		printk(KERN_DEBUG "%s: authentication with AP %s"
		       " timed out\n",
		       dev->name, print_mac(mac, ifsta->bssid));
		ifsta->state = IEEE80211_DISABLED;
		return;
	}

	ifsta->state = IEEE80211_AUTHENTICATE;
	printk(KERN_DEBUG "%s: authenticate with AP %s\n",
	       dev->name, print_mac(mac, ifsta->bssid));

	ieee80211_send_auth(dev, ifsta, 1, NULL, 0, 0);

	mod_timer(&ifsta->timer, jiffies + IEEE80211_AUTH_TIMEOUT);
}


static void ieee80211_send_assoc(struct net_device *dev,
				 struct ieee80211_if_sta *ifsta)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_hw_mode *mode;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	u8 *pos, *ies;
	int i, len;
	u16 capab;
	struct ieee80211_sta_bss *bss;
	int wmm = 0;

	skb = dev_alloc_skb(local->hw.extra_tx_headroom +
			    sizeof(*mgmt) + 200 + ifsta->extra_ie_len +
			    ifsta->ssid_len);
	if (!skb) {
		printk(KERN_DEBUG "%s: failed to allocate buffer for assoc "
		       "frame\n", dev->name);
		return;
	}
	skb_reserve(skb, local->hw.extra_tx_headroom);

	mode = local->oper_hw_mode;
	capab = ifsta->capab;
	if (mode->mode == MODE_IEEE80211G) {
		capab |= WLAN_CAPABILITY_SHORT_SLOT_TIME |
			WLAN_CAPABILITY_SHORT_PREAMBLE;
	}
	bss = ieee80211_rx_bss_get(dev, ifsta->bssid, local->hw.conf.channel,
				   ifsta->ssid, ifsta->ssid_len);
	if (bss) {
		if (bss->capability & WLAN_CAPABILITY_PRIVACY)
			capab |= WLAN_CAPABILITY_PRIVACY;
		if (bss->wmm_ie) {
			wmm = 1;
		}
		ieee80211_rx_bss_put(dev, bss);
	}

	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
	memset(mgmt, 0, 24);
	memcpy(mgmt->da, ifsta->bssid, ETH_ALEN);
	memcpy(mgmt->sa, dev->dev_addr, ETH_ALEN);
	memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);

	if (ifsta->flags & IEEE80211_STA_PREV_BSSID_SET) {
		skb_put(skb, 10);
		mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT,
						   IEEE80211_STYPE_REASSOC_REQ);
		mgmt->u.reassoc_req.capab_info = cpu_to_le16(capab);
		mgmt->u.reassoc_req.listen_interval = cpu_to_le16(1);
		memcpy(mgmt->u.reassoc_req.current_ap, ifsta->prev_bssid,
		       ETH_ALEN);
	} else {
		skb_put(skb, 4);
		mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT,
						   IEEE80211_STYPE_ASSOC_REQ);
		mgmt->u.assoc_req.capab_info = cpu_to_le16(capab);
		mgmt->u.assoc_req.listen_interval = cpu_to_le16(1);
	}

	/* SSID */
	ies = pos = skb_put(skb, 2 + ifsta->ssid_len);
	*pos++ = WLAN_EID_SSID;
	*pos++ = ifsta->ssid_len;
	memcpy(pos, ifsta->ssid, ifsta->ssid_len);

	len = mode->num_rates;
	if (len > 8)
		len = 8;
	pos = skb_put(skb, len + 2);
	*pos++ = WLAN_EID_SUPP_RATES;
	*pos++ = len;
	for (i = 0; i < len; i++) {
		int rate = mode->rates[i].rate;
		*pos++ = (u8) (rate / 5);
	}

	if (mode->num_rates > len) {
		pos = skb_put(skb, mode->num_rates - len + 2);
		*pos++ = WLAN_EID_EXT_SUPP_RATES;
		*pos++ = mode->num_rates - len;
		for (i = len; i < mode->num_rates; i++) {
			int rate = mode->rates[i].rate;
			*pos++ = (u8) (rate / 5);
		}
	}

	if (ifsta->extra_ie) {
		pos = skb_put(skb, ifsta->extra_ie_len);
		memcpy(pos, ifsta->extra_ie, ifsta->extra_ie_len);
	}

	if (wmm && (ifsta->flags & IEEE80211_STA_WMM_ENABLED)) {
		pos = skb_put(skb, 9);
		*pos++ = WLAN_EID_VENDOR_SPECIFIC;
		*pos++ = 7; /* len */
		*pos++ = 0x00; /* Microsoft OUI 00:50:F2 */
		*pos++ = 0x50;
		*pos++ = 0xf2;
		*pos++ = 2; /* WME */
		*pos++ = 0; /* WME info */
		*pos++ = 1; /* WME ver */
		*pos++ = 0;
	}

	kfree(ifsta->assocreq_ies);
	ifsta->assocreq_ies_len = (skb->data + skb->len) - ies;
	ifsta->assocreq_ies = kmalloc(ifsta->assocreq_ies_len, GFP_KERNEL);
	if (ifsta->assocreq_ies)
		memcpy(ifsta->assocreq_ies, ies, ifsta->assocreq_ies_len);

	ieee80211_sta_tx(dev, skb, 0);
}


static void ieee80211_send_deauth(struct net_device *dev,
				  struct ieee80211_if_sta *ifsta, u16 reason)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;

	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*mgmt));
	if (!skb) {
		printk(KERN_DEBUG "%s: failed to allocate buffer for deauth "
		       "frame\n", dev->name);
		return;
	}
	skb_reserve(skb, local->hw.extra_tx_headroom);

	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
	memset(mgmt, 0, 24);
	memcpy(mgmt->da, ifsta->bssid, ETH_ALEN);
	memcpy(mgmt->sa, dev->dev_addr, ETH_ALEN);
	memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
	mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT,
					   IEEE80211_STYPE_DEAUTH);
	skb_put(skb, 2);
	mgmt->u.deauth.reason_code = cpu_to_le16(reason);

	ieee80211_sta_tx(dev, skb, 0);
}


static void ieee80211_send_disassoc(struct net_device *dev,
				    struct ieee80211_if_sta *ifsta, u16 reason)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;

	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*mgmt));
	if (!skb) {
		printk(KERN_DEBUG "%s: failed to allocate buffer for disassoc "
		       "frame\n", dev->name);
		return;
	}
	skb_reserve(skb, local->hw.extra_tx_headroom);

	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
	memset(mgmt, 0, 24);
	memcpy(mgmt->da, ifsta->bssid, ETH_ALEN);
	memcpy(mgmt->sa, dev->dev_addr, ETH_ALEN);
	memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
	mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT,
					   IEEE80211_STYPE_DISASSOC);
	skb_put(skb, 2);
	mgmt->u.disassoc.reason_code = cpu_to_le16(reason);

	ieee80211_sta_tx(dev, skb, 0);
}


static int ieee80211_privacy_mismatch(struct net_device *dev,
				      struct ieee80211_if_sta *ifsta)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_sta_bss *bss;
	int bss_privacy;
	int wep_privacy;
	int privacy_invoked;

	if (!ifsta || (ifsta->flags & IEEE80211_STA_MIXED_CELL))
		return 0;

	bss = ieee80211_rx_bss_get(dev, ifsta->bssid, local->hw.conf.channel,
				   ifsta->ssid, ifsta->ssid_len);
	if (!bss)
		return 0;

	bss_privacy = !!(bss->capability & WLAN_CAPABILITY_PRIVACY);
	wep_privacy = !!ieee80211_sta_wep_configured(dev);
	privacy_invoked = !!(ifsta->flags & IEEE80211_STA_PRIVACY_INVOKED);

	ieee80211_rx_bss_put(dev, bss);

	if ((bss_privacy == wep_privacy) || (bss_privacy == privacy_invoked))
		return 0;

	return 1;
}


static void ieee80211_associate(struct net_device *dev,
				struct ieee80211_if_sta *ifsta)
{
	DECLARE_MAC_BUF(mac);

	ifsta->assoc_tries++;
	if (ifsta->assoc_tries > IEEE80211_ASSOC_MAX_TRIES) {
		printk(KERN_DEBUG "%s: association with AP %s"
		       " timed out\n",
		       dev->name, print_mac(mac, ifsta->bssid));
		ifsta->state = IEEE80211_DISABLED;
		return;
	}

	ifsta->state = IEEE80211_ASSOCIATE;
	printk(KERN_DEBUG "%s: associate with AP %s\n",
	       dev->name, print_mac(mac, ifsta->bssid));
	if (ieee80211_privacy_mismatch(dev, ifsta)) {
		printk(KERN_DEBUG "%s: mismatch in privacy configuration and "
		       "mixed-cell disabled - abort association\n", dev->name);
		ifsta->state = IEEE80211_DISABLED;
		return;
	}

	ieee80211_send_assoc(dev, ifsta);

	mod_timer(&ifsta->timer, jiffies + IEEE80211_ASSOC_TIMEOUT);
}


static void ieee80211_associated(struct net_device *dev,
				 struct ieee80211_if_sta *ifsta)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct sta_info *sta;
	int disassoc;
	DECLARE_MAC_BUF(mac);

	/* TODO: start monitoring current AP signal quality and number of
	 * missed beacons. Scan other channels every now and then and search
	 * for better APs. */
	/* TODO: remove expired BSSes */

	ifsta->state = IEEE80211_ASSOCIATED;

	sta = sta_info_get(local, ifsta->bssid);
	if (!sta) {
		printk(KERN_DEBUG "%s: No STA entry for own AP %s\n",
		       dev->name, print_mac(mac, ifsta->bssid));
		disassoc = 1;
	} else {
		disassoc = 0;
		if (time_after(jiffies,
			       sta->last_rx + IEEE80211_MONITORING_INTERVAL)) {
			if (ifsta->flags & IEEE80211_STA_PROBEREQ_POLL) {
				printk(KERN_DEBUG "%s: No ProbeResp from "
				       "current AP %s - assume out of "
				       "range\n",
				       dev->name, print_mac(mac, ifsta->bssid));
				disassoc = 1;
				sta_info_free(sta);
			} else
				ieee80211_send_probe_req(dev, ifsta->bssid,
							 local->scan_ssid,
							 local->scan_ssid_len);
			ifsta->flags ^= IEEE80211_STA_PROBEREQ_POLL;
		} else {
			ifsta->flags &= ~IEEE80211_STA_PROBEREQ_POLL;
			if (time_after(jiffies, ifsta->last_probe +
				       IEEE80211_PROBE_INTERVAL)) {
				ifsta->last_probe = jiffies;
				ieee80211_send_probe_req(dev, ifsta->bssid,
							 ifsta->ssid,
							 ifsta->ssid_len);
			}
		}
		sta_info_put(sta);
	}
	if (disassoc) {
		ifsta->state = IEEE80211_DISABLED;
		ieee80211_set_associated(dev, ifsta, 0);
	} else {
		mod_timer(&ifsta->timer, jiffies +
				      IEEE80211_MONITORING_INTERVAL);
	}
}


static void ieee80211_send_probe_req(struct net_device *dev, u8 *dst,
				     u8 *ssid, size_t ssid_len)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_hw_mode *mode;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	u8 *pos, *supp_rates, *esupp_rates = NULL;
	int i;

	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*mgmt) + 200);
	if (!skb) {
		printk(KERN_DEBUG "%s: failed to allocate buffer for probe "
		       "request\n", dev->name);
		return;
	}
	skb_reserve(skb, local->hw.extra_tx_headroom);

	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
	memset(mgmt, 0, 24);
	mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT,
					   IEEE80211_STYPE_PROBE_REQ);
	memcpy(mgmt->sa, dev->dev_addr, ETH_ALEN);
	if (dst) {
		memcpy(mgmt->da, dst, ETH_ALEN);
		memcpy(mgmt->bssid, dst, ETH_ALEN);
	} else {
		memset(mgmt->da, 0xff, ETH_ALEN);
		memset(mgmt->bssid, 0xff, ETH_ALEN);
	}
	pos = skb_put(skb, 2 + ssid_len);
	*pos++ = WLAN_EID_SSID;
	*pos++ = ssid_len;
	memcpy(pos, ssid, ssid_len);

	supp_rates = skb_put(skb, 2);
	supp_rates[0] = WLAN_EID_SUPP_RATES;
	supp_rates[1] = 0;
	mode = local->oper_hw_mode;
	for (i = 0; i < mode->num_rates; i++) {
		struct ieee80211_rate *rate = &mode->rates[i];
		if (!(rate->flags & IEEE80211_RATE_SUPPORTED))
			continue;
		if (esupp_rates) {
			pos = skb_put(skb, 1);
			esupp_rates[1]++;
		} else if (supp_rates[1] == 8) {
			esupp_rates = skb_put(skb, 3);
			esupp_rates[0] = WLAN_EID_EXT_SUPP_RATES;
			esupp_rates[1] = 1;
			pos = &esupp_rates[2];
		} else {
			pos = skb_put(skb, 1);
			supp_rates[1]++;
		}
		*pos = rate->rate / 5;
	}

	ieee80211_sta_tx(dev, skb, 0);
}


static int ieee80211_sta_wep_configured(struct net_device *dev)
{
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	if (!sdata || !sdata->default_key ||
	    sdata->default_key->conf.alg != ALG_WEP)
		return 0;
	return 1;
}


static void ieee80211_auth_completed(struct net_device *dev,
				     struct ieee80211_if_sta *ifsta)
{
	printk(KERN_DEBUG "%s: authenticated\n", dev->name);
	ifsta->flags |= IEEE80211_STA_AUTHENTICATED;
	ieee80211_associate(dev, ifsta);
}


static void ieee80211_auth_challenge(struct net_device *dev,
				     struct ieee80211_if_sta *ifsta,
				     struct ieee80211_mgmt *mgmt,
				     size_t len)
{
	u8 *pos;
	struct ieee802_11_elems elems;

	printk(KERN_DEBUG "%s: replying to auth challenge\n", dev->name);
	pos = mgmt->u.auth.variable;
	ieee802_11_parse_elems(pos, len - (pos - (u8 *) mgmt), &elems);
	if (!elems.challenge) {
		printk(KERN_DEBUG "%s: no challenge IE in shared key auth "
		       "frame\n", dev->name);
		return;
	}
	ieee80211_send_auth(dev, ifsta, 3, elems.challenge - 2,
			    elems.challenge_len + 2, 1);
}


static void ieee80211_rx_mgmt_auth(struct net_device *dev,
				   struct ieee80211_if_sta *ifsta,
				   struct ieee80211_mgmt *mgmt,
				   size_t len)
{
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	u16 auth_alg, auth_transaction, status_code;
	DECLARE_MAC_BUF(mac);

	if (ifsta->state != IEEE80211_AUTHENTICATE &&
	    sdata->type != IEEE80211_IF_TYPE_IBSS) {
		printk(KERN_DEBUG "%s: authentication frame received from "
		       "%s, but not in authenticate state - ignored\n",
		       dev->name, print_mac(mac, mgmt->sa));
		return;
	}

	if (len < 24 + 6) {
		printk(KERN_DEBUG "%s: too short (%zd) authentication frame "
		       "received from %s - ignored\n",
		       dev->name, len, print_mac(mac, mgmt->sa));