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;
+}