mac80211: generalise work handling

In order to use auth/assoc for different purposes
other than MLME, it needs to be split up. For other
purposes, a generic work handling (potentially on
another channel) will be useful.

To achieve that, this patch moves much of the MLME
work handling out of mlme into a new work API. The
API can currently handle probing a specific AP,
authentication and association. The MLME previously
handled probe/authentication as one step and will
continue to do so, but they are separate in the new
work handling.

Work items are RCU-managed to be able to check for
existence of an item for a specific frame in the RX
path, but they can be re-used which the MLME right
now will do for its combined probe/auth step.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 902 insertions, 0 deletions

diff --git a/net/mac80211/work.c b/net/mac80211/work.c
new file mode 100644
index 000000000000..8b8961d806ab
--- /dev/null
+++ b/net/mac80211/work.c
@@ -0,0 +1,902 @@
+/*
+ * mac80211 work implementation
+ *
+ * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
+ * Copyright 2004, Instant802 Networks, Inc.
+ * Copyright 2005, Devicescape Software, Inc.
+ * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
+ * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
+ * Copyright 2009, 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.
+ */
+
+#include <linux/delay.h>
+#include <linux/if_ether.h>
+#include <linux/skbuff.h>
+#include <linux/if_arp.h>
+#include <linux/etherdevice.h>
+#include <linux/crc32.h>
+#include <net/mac80211.h>
+#include <asm/unaligned.h>
+
+#include "ieee80211_i.h"
+#include "rate.h"
+
+#define IEEE80211_AUTH_TIMEOUT (HZ / 5)
+#define IEEE80211_AUTH_MAX_TRIES 3
+#define IEEE80211_ASSOC_TIMEOUT (HZ / 5)
+#define IEEE80211_ASSOC_MAX_TRIES 3
+#define IEEE80211_MAX_PROBE_TRIES 5
+
+enum work_action {
+	WORK_ACT_NONE,
+	WORK_ACT_TIMEOUT,
+	WORK_ACT_DONE,
+};
+
+
+/* utils */
+static inline void ASSERT_WORK_MTX(struct ieee80211_local *local)
+{
+	WARN_ON(!mutex_is_locked(&local->work_mtx));
+}
+
+/*
+ * We can have multiple work items (and connection probing)
+ * scheduling this timer, but we need to take care to only
+ * reschedule it when it should fire _earlier_ than it was
+ * asked for before, or if it's not pending right now. This
+ * function ensures that. Note that it then is required to
+ * run this function for all timeouts after the first one
+ * has happened -- the work that runs from this timer will
+ * do that.
+ */
+static void run_again(struct ieee80211_local *local,
+		      unsigned long timeout)
+{
+	ASSERT_WORK_MTX(local);
+
+	if (!timer_pending(&local->work_timer) ||
+	    time_before(timeout, local->work_timer.expires))
+		mod_timer(&local->work_timer, timeout);
+}
+
+static void work_free_rcu(struct rcu_head *head)
+{
+	struct ieee80211_work *wk =
+		container_of(head, struct ieee80211_work, rcu_head);
+
+	kfree(wk);
+}
+
+void free_work(struct ieee80211_work *wk)
+{
+	call_rcu(&wk->rcu_head, work_free_rcu);
+}
+
+static int ieee80211_compatible_rates(const u8 *supp_rates, int supp_rates_len,
+				      struct ieee80211_supported_band *sband,
+				      u32 *rates)
+{
+	int i, j, count;
+	*rates = 0;
+	count = 0;
+	for (i = 0; i < supp_rates_len; i++) {
+		int rate = (supp_rates[i] & 0x7F) * 5;
+
+		for (j = 0; j < sband->n_bitrates; j++)
+			if (sband->bitrates[j].bitrate == rate) {
+				*rates |= BIT(j);
+				count++;
+				break;
+			}
+	}
+
+	return count;
+}
+
+/* frame sending functions */
+
+static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata,
+				 struct ieee80211_work *wk)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct sk_buff *skb;
+	struct ieee80211_mgmt *mgmt;
+	u8 *pos;
+	const u8 *ies, *ht_ie;
+	int i, len, count, rates_len, supp_rates_len;
+	u16 capab;
+	struct ieee80211_supported_band *sband;
+	u32 rates = 0;
+
+	skb = dev_alloc_skb(local->hw.extra_tx_headroom +
+			    sizeof(*mgmt) + 200 + wk->ie_len +
+			    wk->assoc.ssid_len);
+	if (!skb) {
+		printk(KERN_DEBUG "%s: failed to allocate buffer for assoc "
+		       "frame\n", sdata->name);
+		return;
+	}
+	skb_reserve(skb, local->hw.extra_tx_headroom);
+
+	sband = local->hw.wiphy->bands[wk->chan->band];
+
+	capab = WLAN_CAPABILITY_ESS;
+
+	if (sband->band == IEEE80211_BAND_2GHZ) {
+		if (!(local->hw.flags & IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE))
+			capab |= WLAN_CAPABILITY_SHORT_SLOT_TIME;
+		if (!(local->hw.flags & IEEE80211_HW_2GHZ_SHORT_PREAMBLE_INCAPABLE))
+			capab |= WLAN_CAPABILITY_SHORT_PREAMBLE;
+	}
+
+	if (wk->assoc.capability & WLAN_CAPABILITY_PRIVACY)
+		capab |= WLAN_CAPABILITY_PRIVACY;
+
+	/*
+	 * Get all rates supported by the device and the AP as
+	 * some APs don't like getting a superset of their rates
+	 * in the association request (e.g. D-Link DAP 1353 in
+	 * b-only mode)...
+	 */
+	rates_len = ieee80211_compatible_rates(wk->assoc.supp_rates,
+					       wk->assoc.supp_rates_len,
+					       sband, &rates);
+
+	if ((wk->assoc.capability & WLAN_CAPABILITY_SPECTRUM_MGMT) &&
+	    (local->hw.flags & IEEE80211_HW_SPECTRUM_MGMT))
+		capab |= WLAN_CAPABILITY_SPECTRUM_MGMT;
+
+	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
+	memset(mgmt, 0, 24);
+	memcpy(mgmt->da, wk->filter_ta, ETH_ALEN);
+	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
+	memcpy(mgmt->bssid, wk->filter_ta, ETH_ALEN);
+
+	if (!is_zero_ether_addr(wk->assoc.prev_bssid)) {
+		skb_put(skb, 10);
+		mgmt->frame_control = cpu_to_le16(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(local->hw.conf.listen_interval);
+		memcpy(mgmt->u.reassoc_req.current_ap, wk->assoc.prev_bssid,
+		       ETH_ALEN);
+	} else {
+		skb_put(skb, 4);
+		mgmt->frame_control = cpu_to_le16(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(local->hw.conf.listen_interval);
+	}
+
+	/* SSID */
+	ies = pos = skb_put(skb, 2 + wk->assoc.ssid_len);
+	*pos++ = WLAN_EID_SSID;
+	*pos++ = wk->assoc.ssid_len;
+	memcpy(pos, wk->assoc.ssid, wk->assoc.ssid_len);
+
+	/* add all rates which were marked to be used above */
+	supp_rates_len = rates_len;
+	if (supp_rates_len > 8)
+		supp_rates_len = 8;
+
+	len = sband->n_bitrates;
+	pos = skb_put(skb, supp_rates_len + 2);
+	*pos++ = WLAN_EID_SUPP_RATES;
+	*pos++ = supp_rates_len;
+
+	count = 0;
+	for (i = 0; i < sband->n_bitrates; i++) {
+		if (BIT(i) & rates) {
+			int rate = sband->bitrates[i].bitrate;
+			*pos++ = (u8) (rate / 5);
+			if (++count == 8)
+				break;
+		}
+	}
+
+	if (rates_len > count) {
+		pos = skb_put(skb, rates_len - count + 2);
+		*pos++ = WLAN_EID_EXT_SUPP_RATES;
+		*pos++ = rates_len - count;
+
+		for (i++; i < sband->n_bitrates; i++) {
+			if (BIT(i) & rates) {
+				int rate = sband->bitrates[i].bitrate;
+				*pos++ = (u8) (rate / 5);
+			}
+		}
+	}
+
+	if (capab & WLAN_CAPABILITY_SPECTRUM_MGMT) {
+		/* 1. power capabilities */
+		pos = skb_put(skb, 4);
+		*pos++ = WLAN_EID_PWR_CAPABILITY;
+		*pos++ = 2;
+		*pos++ = 0; /* min tx power */
+		*pos++ = local->hw.conf.channel->max_power; /* max tx power */
+
+		/* 2. supported channels */
+		/* TODO: get this in reg domain format */
+		pos = skb_put(skb, 2 * sband->n_channels + 2);
+		*pos++ = WLAN_EID_SUPPORTED_CHANNELS;
+		*pos++ = 2 * sband->n_channels;
+		for (i = 0; i < sband->n_channels; i++) {
+			*pos++ = ieee80211_frequency_to_channel(
+					sband->channels[i].center_freq);
+			*pos++ = 1; /* one channel in the subband*/
+		}
+	}
+
+	if (wk->ie_len && wk->ie) {
+		pos = skb_put(skb, wk->ie_len);
+		memcpy(pos, wk->ie, wk->ie_len);
+	}
+
+	if (wk->assoc.wmm_used && local->hw.queues >= 4) {
+		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;
+	}
+
+	/* wmm support is a must to HT */
+	/*
+	 * IEEE802.11n does not allow TKIP/WEP as pairwise
+	 * ciphers in HT mode. We still associate in non-ht
+	 * mode (11a/b/g) if any one of these ciphers is
+	 * configured as pairwise.
+	 */
+	if (wk->assoc.use_11n && wk->assoc.wmm_used &&
+	    (local->hw.queues >= 4) &&
+	    sband->ht_cap.ht_supported &&
+	    (ht_ie = wk->assoc.ht_information_ie) &&
+	    ht_ie[1] >= sizeof(struct ieee80211_ht_info)) {
+		struct ieee80211_ht_info *ht_info =
+			(struct ieee80211_ht_info *)(ht_ie + 2);
+		u16 cap = sband->ht_cap.cap;
+		__le16 tmp;
+		u32 flags = local->hw.conf.channel->flags;
+
+		/* determine capability flags */
+
+		if (ieee80211_disable_40mhz_24ghz &&
+		    sband->band == IEEE80211_BAND_2GHZ) {
+			cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
+			cap &= ~IEEE80211_HT_CAP_SGI_40;
+		}
+
+		switch (ht_info->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
+		case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
+			if (flags & IEEE80211_CHAN_NO_HT40PLUS) {
+				cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
+				cap &= ~IEEE80211_HT_CAP_SGI_40;
+			}
+			break;
+		case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
+			if (flags & IEEE80211_CHAN_NO_HT40MINUS) {
+				cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
+				cap &= ~IEEE80211_HT_CAP_SGI_40;
+			}
+			break;
+		}
+
+		/* set SM PS mode properly */
+		cap &= ~IEEE80211_HT_CAP_SM_PS;
+		switch (wk->assoc.smps) {
+		case IEEE80211_SMPS_AUTOMATIC:
+		case IEEE80211_SMPS_NUM_MODES:
+			WARN_ON(1);
+		case IEEE80211_SMPS_OFF:
+			cap |= WLAN_HT_CAP_SM_PS_DISABLED <<
+				IEEE80211_HT_CAP_SM_PS_SHIFT;
+			break;
+		case IEEE80211_SMPS_STATIC:
+			cap |= WLAN_HT_CAP_SM_PS_STATIC <<
+				IEEE80211_HT_CAP_SM_PS_SHIFT;
+			break;
+		case IEEE80211_SMPS_DYNAMIC:
+			cap |= WLAN_HT_CAP_SM_PS_DYNAMIC <<
+				IEEE80211_HT_CAP_SM_PS_SHIFT;
+			break;
+		}
+
+		/* reserve and fill IE */
+
+		pos = skb_put(skb, sizeof(struct ieee80211_ht_cap) + 2);
+		*pos++ = WLAN_EID_HT_CAPABILITY;
+		*pos++ = sizeof(struct ieee80211_ht_cap);
+		memset(pos, 0, sizeof(struct ieee80211_ht_cap));
+
+		/* capability flags */
+		tmp = cpu_to_le16(cap);
+		memcpy(pos, &tmp, sizeof(u16));
+		pos += sizeof(u16);
+
+		/* AMPDU parameters */
+		*pos++ = sband->ht_cap.ampdu_factor |
+			 (sband->ht_cap.ampdu_density <<
+				IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT);
+
+		/* MCS set */
+		memcpy(pos, &sband->ht_cap.mcs, sizeof(sband->ht_cap.mcs));
+		pos += sizeof(sband->ht_cap.mcs);
+
+		/* extended capabilities */
+		pos += sizeof(__le16);
+
+		/* BF capabilities */
+		pos += sizeof(__le32);
+
+		/* antenna selection */
+		pos += sizeof(u8);
+	}
+
+	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
+	ieee80211_tx_skb(sdata, skb);
+}
+
+static void ieee80211_remove_auth_bss(struct ieee80211_local *local,
+				      struct ieee80211_work *wk)
+{
+	struct cfg80211_bss *cbss;
+	u16 capa_val = WLAN_CAPABILITY_ESS;
+
+	if (wk->probe_auth.privacy)
+		capa_val |= WLAN_CAPABILITY_PRIVACY;
+
+	cbss = cfg80211_get_bss(local->hw.wiphy, wk->chan, wk->filter_ta,
+				wk->probe_auth.ssid, wk->probe_auth.ssid_len,
+				WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_PRIVACY,
+				capa_val);
+	if (!cbss)
+		return;
+
+	cfg80211_unlink_bss(local->hw.wiphy, cbss);
+	cfg80211_put_bss(cbss);
+}
+
+static enum work_action __must_check
+ieee80211_direct_probe(struct ieee80211_work *wk)
+{
+	struct ieee80211_sub_if_data *sdata = wk->sdata;
+	struct ieee80211_local *local = sdata->local;
+
+	wk->probe_auth.tries++;
+	if (wk->probe_auth.tries > IEEE80211_AUTH_MAX_TRIES) {
+		printk(KERN_DEBUG "%s: direct probe to AP %pM timed out\n",
+		       sdata->name, wk->filter_ta);
+
+		/*
+		 * Most likely AP is not in the range so remove the
+		 * bss struct for that AP.
+		 */
+		ieee80211_remove_auth_bss(local, wk);
+
+		/*
+		 * We might have a pending scan which had no chance to run yet
+		 * due to work needing to be done. Hence, queue the STAs work
+		 * again for that.
+		 */
+		ieee80211_queue_work(&local->hw, &local->work_work);
+		return WORK_ACT_TIMEOUT;
+	}
+
+	printk(KERN_DEBUG "%s: direct probe to AP %pM (try %d)\n",
+			sdata->name, wk->filter_ta, wk->probe_auth.tries);
+
+	/*
+	 * Direct probe is sent to broadcast address as some APs
+	 * will not answer to direct packet in unassociated state.
+	 */
+	ieee80211_send_probe_req(sdata, NULL, wk->probe_auth.ssid,
+				 wk->probe_auth.ssid_len, NULL, 0);
+
+	wk->timeout = jiffies + IEEE80211_AUTH_TIMEOUT;
+	run_again(local, wk->timeout);
+
+	return WORK_ACT_NONE;
+}
+
+
+static enum work_action __must_check
+ieee80211_authenticate(struct ieee80211_work *wk)
+{
+	struct ieee80211_sub_if_data *sdata = wk->sdata;
+	struct ieee80211_local *local = sdata->local;
+
+	wk->probe_auth.tries++;
+	if (wk->probe_auth.tries > IEEE80211_AUTH_MAX_TRIES) {
+		printk(KERN_DEBUG "%s: authentication with AP %pM"
+		       " timed out\n", sdata->name, wk->filter_ta);
+
+		/*
+		 * Most likely AP is not in the range so remove the
+		 * bss struct for that AP.
+		 */
+		ieee80211_remove_auth_bss(local, wk);
+
+		/*
+		 * We might have a pending scan which had no chance to run yet
+		 * due to work needing to be done. Hence, queue the STAs work
+		 * again for that.
+		 */
+		ieee80211_queue_work(&local->hw, &local->work_work);
+		return WORK_ACT_TIMEOUT;
+	}
+
+	printk(KERN_DEBUG "%s: authenticate with AP %pM (try %d)\n",
+	       sdata->name, wk->filter_ta, wk->probe_auth.tries);
+
+	ieee80211_send_auth(sdata, 1, wk->probe_auth.algorithm, wk->ie,
+			    wk->ie_len, wk->filter_ta, NULL, 0, 0);
+	wk->probe_auth.transaction = 2;
+
+	wk->timeout = jiffies + IEEE80211_AUTH_TIMEOUT;
+	run_again(local, wk->timeout);
+
+	return WORK_ACT_NONE;
+}
+
+static enum work_action __must_check
+ieee80211_associate(struct ieee80211_work *wk)
+{
+	struct ieee80211_sub_if_data *sdata = wk->sdata;
+	struct ieee80211_local *local = sdata->local;
+
+	wk->assoc.tries++;
+	if (wk->assoc.tries > IEEE80211_ASSOC_MAX_TRIES) {
+		printk(KERN_DEBUG "%s: association with AP %pM"
+		       " timed out\n",
+		       sdata->name, wk->filter_ta);
+
+		/*
+		 * Most likely AP is not in the range so remove the
+		 * bss struct for that AP.
+		 */
+		if (wk->assoc.bss)
+			cfg80211_unlink_bss(local->hw.wiphy,
+					    &wk->assoc.bss->cbss);
+
+		/*
+		 * We might have a pending scan which had no chance to run yet
+		 * due to work needing to be done. Hence, queue the STAs work
+		 * again for that.
+		 */
+		ieee80211_queue_work(&local->hw, &local->work_work);
+		return WORK_ACT_TIMEOUT;
+	}
+
+	printk(KERN_DEBUG "%s: associate with AP %pM (try %d)\n",
+	       sdata->name, wk->filter_ta, wk->assoc.tries);
+	ieee80211_send_assoc(sdata, wk);
+
+	wk->timeout = jiffies + IEEE80211_ASSOC_TIMEOUT;
+	run_again(local, wk->timeout);
+
+	return WORK_ACT_NONE;
+}
+
+static void ieee80211_auth_challenge(struct ieee80211_work *wk,
+				     struct ieee80211_mgmt *mgmt,
+				     size_t len)
+{
+	struct ieee80211_sub_if_data *sdata = wk->sdata;
+	u8 *pos;
+	struct ieee802_11_elems elems;
+
+	pos = mgmt->u.auth.variable;
+	ieee802_11_parse_elems(pos, len - (pos - (u8 *) mgmt), &elems);
+	if (!elems.challenge)
+		return;
+	ieee80211_send_auth(sdata, 3, wk->probe_auth.algorithm,
+			    elems.challenge - 2, elems.challenge_len + 2,
+			    wk->filter_ta, wk->probe_auth.key,
+			    wk->probe_auth.key_len, wk->probe_auth.key_idx);
+	wk->probe_auth.transaction = 4;
+}
+
+static enum work_action __must_check
+ieee80211_rx_mgmt_auth(struct ieee80211_work *wk,
+		       struct ieee80211_mgmt *mgmt, size_t len)
+{
+	u16 auth_alg, auth_transaction, status_code;
+
+	if (wk->type != IEEE80211_WORK_AUTH)
+		return WORK_ACT_NONE;
+
+	if (len < 24 + 6)
+		return WORK_ACT_NONE;
+
+	auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
+	auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
+	status_code = le16_to_cpu(mgmt->u.auth.status_code);
+
+	if (auth_alg != wk->probe_auth.algorithm ||
+	    auth_transaction != wk->probe_auth.transaction)
+		return WORK_ACT_NONE;
+
+	if (status_code != WLAN_STATUS_SUCCESS) {
+		printk(KERN_DEBUG "%s: %pM denied authentication (status %d)\n",
+		       wk->sdata->name, mgmt->sa, status_code);
+		return WORK_ACT_DONE;
+	}
+
+	switch (wk->probe_auth.algorithm) {
+	case WLAN_AUTH_OPEN:
+	case WLAN_AUTH_LEAP:
+	case WLAN_AUTH_FT:
+		break;
+	case WLAN_AUTH_SHARED_KEY:
+		if (wk->probe_auth.transaction != 4) {
+			ieee80211_auth_challenge(wk, mgmt, len);
+			/* need another frame */
+			return WORK_ACT_NONE;
+		}
+		break;
+	default:
+		WARN_ON(1);
+		return WORK_ACT_NONE;
+	}
+
+	printk(KERN_DEBUG "%s: authenticated\n", wk->sdata->name);
+	return WORK_ACT_DONE;
+}
+
+static enum work_action __must_check
+ieee80211_rx_mgmt_assoc_resp(struct ieee80211_work *wk,
+			     struct ieee80211_mgmt *mgmt, size_t len,
+			     bool reassoc)
+{
+	struct ieee80211_sub_if_data *sdata = wk->sdata;
+	struct ieee80211_local *local = sdata->local;
+	u16 capab_info, status_code, aid;
+	struct ieee802_11_elems elems;
+	u8 *pos;
+
+	/*
+	 * AssocResp and ReassocResp have identical structure, so process both
+	 * of them in this function.
+	 */
+
+	if (len < 24 + 6)
+		return WORK_ACT_NONE;
+
+	capab_info = le16_to_cpu(mgmt->u.assoc_resp.capab_info);
+	status_code = le16_to_cpu(mgmt->u.assoc_resp.status_code);
+	aid = le16_to_cpu(mgmt->u.assoc_resp.aid);
+
+	printk(KERN_DEBUG "%s: RX %sssocResp from %pM (capab=0x%x "
+	       "status=%d aid=%d)\n",
+	       sdata->name, reassoc ? "Rea" : "A", mgmt->sa,
+	       capab_info, status_code, (u16)(aid & ~(BIT(15) | BIT(14))));
+
+	pos = mgmt->u.assoc_resp.variable;
+	ieee802_11_parse_elems(pos, len - (pos - (u8 *) mgmt), &elems);
+
+	if (status_code == WLAN_STATUS_ASSOC_REJECTED_TEMPORARILY &&
+	    elems.timeout_int && elems.timeout_int_len == 5 &&
+	    elems.timeout_int[0] == WLAN_TIMEOUT_ASSOC_COMEBACK) {
+		u32 tu, ms;
+		tu = get_unaligned_le32(elems.timeout_int + 1);
+		ms = tu * 1024 / 1000;
+		printk(KERN_DEBUG "%s: AP rejected association temporarily; "
+		       "comeback duration %u TU (%u ms)\n",
+		       sdata->name, tu, ms);
+		wk->timeout = jiffies + msecs_to_jiffies(ms);
+		if (ms > IEEE80211_ASSOC_TIMEOUT)
+			run_again(local, wk->timeout);
+		return WORK_ACT_NONE;
+	}
+
+	if (status_code != WLAN_STATUS_SUCCESS)
+		printk(KERN_DEBUG "%s: AP denied association (code=%d)\n",
+		       sdata->name, status_code);
+	else
+		printk(KERN_DEBUG "%s: associated\n", sdata->name);
+
+	return WORK_ACT_DONE;
+}
+
+static enum work_action __must_check
+ieee80211_rx_mgmt_probe_resp(struct ieee80211_work *wk,
+			     struct ieee80211_mgmt *mgmt, size_t len,
+			     struct ieee80211_rx_status *rx_status)
+{
+	struct ieee80211_sub_if_data *sdata = wk->sdata;
+	struct ieee80211_local *local = sdata->local;
+	size_t baselen;
+
+	ASSERT_WORK_MTX(local);
+
+	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
+	if (baselen > len)
+		return WORK_ACT_NONE;
+
+	printk(KERN_DEBUG "%s: direct probe responded\n", sdata->name);
+	return WORK_ACT_DONE;
+}
+
+static void ieee80211_work_rx_queued_mgmt(struct ieee80211_local *local,
+					  struct sk_buff *skb)
+{
+	struct ieee80211_rx_status *rx_status;
+	struct ieee80211_mgmt *mgmt;
+	struct ieee80211_work *wk;
+	enum work_action rma = WORK_ACT_NONE;
+	u16 fc;
+
+	rx_status = (struct ieee80211_rx_status *) skb->cb;
+	mgmt = (struct ieee80211_mgmt *) skb->data;
+	fc = le16_to_cpu(mgmt->frame_control);
+
+	mutex_lock(&local->work_mtx);
+
+	list_for_each_entry(wk, &local->work_list, list) {
+		const u8 *bssid = NULL;
+
+		switch (wk->type) {
+		case IEEE80211_WORK_DIRECT_PROBE:
+		case IEEE80211_WORK_AUTH:
+		case IEEE80211_WORK_ASSOC:
+			bssid = wk->filter_ta;
+			break;
+		default:
+			continue;
+		}
+
+		/*
+		 * Before queuing, we already verified mgmt->sa,
+		 * so this is needed just for matching.
+		 */
+		if (compare_ether_addr(bssid, mgmt->bssid))
+			continue;
+
+		switch (fc & IEEE80211_FCTL_STYPE) {
+		case IEEE80211_STYPE_PROBE_RESP:
+			rma = ieee80211_rx_mgmt_probe_resp(wk, mgmt, skb->len,
+							   rx_status);
+			break;
+		case IEEE80211_STYPE_AUTH:
+			rma = ieee80211_rx_mgmt_auth(wk, mgmt, skb->len);
+			break;
+		case IEEE80211_STYPE_ASSOC_RESP:
+			rma = ieee80211_rx_mgmt_assoc_resp(wk, mgmt,
+							   skb->len, false);
+			break;
+		case IEEE80211_STYPE_REASSOC_RESP:
+			rma = ieee80211_rx_mgmt_assoc_resp(wk, mgmt,
+							   skb->len, true);
+			break;
+		default:
+			WARN_ON(1);
+		}
+		/*
+		 * We've processed this frame for that work, so it can't
+		 * belong to another work struct.
+		 * NB: this is also required for correctness for 'rma'!
+		 */
+		break;
+	}
+
+	switch (rma) {
+	case WORK_ACT_NONE:
+		break;
+	case WORK_ACT_DONE:
+		list_del_rcu(&wk->list);
+		break;
+	default:
+		WARN(1, "unexpected: %d", rma);
+	}
+
+	mutex_unlock(&local->work_mtx);
+
+	if (rma != WORK_ACT_DONE)
+		goto out;
+
+	switch (wk->done(wk, skb)) {
+	case WORK_DONE_DESTROY:
+		free_work(wk);
+		break;
+	case WORK_DONE_REQUEUE:
+		synchronize_rcu();
+		wk->timeout = jiffies; /* run again directly */
+		mutex_lock(&local->work_mtx);
+		list_add_tail(&wk->list, &local->work_list);
+		mutex_unlock(&local->work_mtx);
+	}
+
+ out:
+	kfree_skb(skb);
+}
+
+static void ieee80211_work_timer(unsigned long data)
+{
+	struct ieee80211_local *local = (void *) data;
+
+	if (local->quiescing)
+		return;
+
+	ieee80211_queue_work(&local->hw, &local->work_work);
+}
+
+static void ieee80211_work_work(struct work_struct *work)
+{
+	struct ieee80211_local *local =
+		container_of(work, struct ieee80211_local, work_work);
+	struct sk_buff *skb;
+	struct ieee80211_work *wk, *tmp;
+	LIST_HEAD(free_work);
+	enum work_action rma;
+
+	if (local->scanning)
+		return;
+
+	/*
+	 * ieee80211_queue_work() should have picked up most cases,
+	 * here we'll pick the the rest.
+	 */
+	if (WARN(local->suspended, "work scheduled while going to suspend\n"))
+		return;
+
+	/* first process frames to avoid timing out while a frame is pending */
+	while ((skb = skb_dequeue(&local->work_skb_queue)))
+		ieee80211_work_rx_queued_mgmt(local, skb);
+
+	ieee80211_recalc_idle(local);
+
+	mutex_lock(&local->work_mtx);
+
+	list_for_each_entry_safe(wk, tmp, &local->work_list, list) {
+		if (time_is_after_jiffies(wk->timeout)) {
+			/*
+			 * This work item isn't supposed to be worked on
+			 * right now, but take care to adjust the timer
+			 * properly.
+			 */
+			run_again(local, wk->timeout);
+			continue;
+		}
+
+		switch (wk->type) {
+		default:
+			WARN_ON(1);
+			/* nothing */
+			rma = WORK_ACT_NONE;
+			break;
+		case IEEE80211_WORK_DIRECT_PROBE:
+			rma = ieee80211_direct_probe(wk);
+			break;
+		case IEEE80211_WORK_AUTH:
+			rma = ieee80211_authenticate(wk);
+			break;
+		case IEEE80211_WORK_ASSOC:
+			rma = ieee80211_associate(wk);
+			break;
+		}
+
+		switch (rma) {
+		case WORK_ACT_NONE:
+			/* no action required */
+			break;
+		case WORK_ACT_TIMEOUT:
+			list_del_rcu(&wk->list);
+			synchronize_rcu();
+			list_add(&wk->list, &free_work);
+			break;
+		default:
+			WARN(1, "unexpected: %d", rma);
+		}
+	}
+
+	if (list_empty(&local->work_list) && local->scan_req)
+		ieee80211_queue_delayed_work(&local->hw,
+					     &local->scan_work,
+					     round_jiffies_relative(0));
+
+	mutex_unlock(&local->work_mtx);
+
+	list_for_each_entry_safe(wk, tmp, &free_work, list) {
+		wk->done(wk, NULL);
+		list_del(&wk->list);
+		kfree(wk);
+	}
+}
+
+void ieee80211_add_work(struct ieee80211_work *wk)
+{
+	struct ieee80211_local *local;
+
+	if (WARN_ON(!wk->chan))
+		return;
+
+	if (WARN_ON(!wk->sdata))
+		return;
+
+	if (WARN_ON(!wk->done))
+		return;
+
+	wk->timeout = jiffies;
+
+	local = wk->sdata->local;
+	mutex_lock(&local->work_mtx);
+	list_add_tail(&wk->list, &local->work_list);
+	mutex_unlock(&local->work_mtx);
+
+	ieee80211_queue_work(&local->hw, &local->work_work);
+}
+
+void ieee80211_work_init(struct ieee80211_local *local)
+{
+	mutex_init(&local->work_mtx);
+	INIT_LIST_HEAD(&local->work_list);
+	setup_timer(&local->work_timer, ieee80211_work_timer,
+		    (unsigned long)local);
+	INIT_WORK(&local->work_work, ieee80211_work_work);
+	skb_queue_head_init(&local->work_skb_queue);
+}
+
+void ieee80211_work_purge(struct ieee80211_sub_if_data *sdata)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_work *wk, *tmp;
+
+	mutex_lock(&local->work_mtx);
+	list_for_each_entry_safe(wk, tmp, &local->work_list, list) {
+		if (wk->sdata != sdata)
+			continue;
+		list_del(&wk->list);
+		free_work(wk);
+	}
+	mutex_unlock(&local->work_mtx);
+}
+
+ieee80211_rx_result ieee80211_work_rx_mgmt(struct ieee80211_sub_if_data *sdata,
+					   struct sk_buff *skb)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_mgmt *mgmt;
+	struct ieee80211_work *wk;
+	u16 fc;
+
+	if (skb->len < 24)
+		return RX_DROP_MONITOR;
+
+	mgmt = (struct ieee80211_mgmt *) skb->data;
+	fc = le16_to_cpu(mgmt->frame_control);
+
+	list_for_each_entry_rcu(wk, &local->work_list, list) {
+		if (sdata != wk->sdata)
+			continue;
+		if (compare_ether_addr(wk->filter_ta, mgmt->sa))
+			continue;
+		if (compare_ether_addr(wk->filter_ta, mgmt->bssid))
+			continue;
+
+		switch (fc & IEEE80211_FCTL_STYPE) {
+		case IEEE80211_STYPE_AUTH:
+		case IEEE80211_STYPE_PROBE_RESP:
+		case IEEE80211_STYPE_ASSOC_RESP:
+		case IEEE80211_STYPE_REASSOC_RESP:
+		case IEEE80211_STYPE_DEAUTH:
+		case IEEE80211_STYPE_DISASSOC:
+			skb_queue_tail(&local->work_skb_queue, skb);
+			ieee80211_queue_work(&local->hw, &local->work_work);
+			return RX_QUEUED;
+		}
+	}
+
+	return RX_CONTINUE;
+}