vmalloc: remove BUG_ON due to racy counting of VM_LAZY_FREE

[linux-2.6/linux-2.6-openrd.git] / net / mac80211 / mesh.c

/*
 * Copyright (c) 2008, 2009 open80211s Ltd.
 * Authors:    Luis Carlos Cobo <luisca@cozybit.com>
 *             Javier Cardona <javier@cozybit.com>
 *
 * 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 <asm/unaligned.h>
#include "ieee80211_i.h"
#include "mesh.h"

#define IEEE80211_MESH_PEER_INACTIVITY_LIMIT (1800 * HZ)
#define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ)
#define IEEE80211_MESH_RANN_INTERVAL         (1 * HZ)

#define MESHCONF_CAPAB_ACCEPT_PLINKS 0x01
#define MESHCONF_CAPAB_FORWARDING    0x08

#define TMR_RUNNING_HK  0
#define TMR_RUNNING_MP  1
#define TMR_RUNNING_MPR 2

int mesh_allocated;
static struct kmem_cache *rm_cache;

void ieee80211s_init(void)
{
        mesh_pathtbl_init();
        mesh_allocated = 1;
        rm_cache = kmem_cache_create("mesh_rmc", sizeof(struct rmc_entry),
                                     0, 0, NULL);
}

void ieee80211s_stop(void)
{
        mesh_pathtbl_unregister();
        kmem_cache_destroy(rm_cache);
}

static void ieee80211_mesh_housekeeping_timer(unsigned long data)
{
        struct ieee80211_sub_if_data *sdata = (void *) data;
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

        set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);

        if (local->quiescing) {
                set_bit(TMR_RUNNING_HK, &ifmsh->timers_running);
                return;
        }

        ieee80211_queue_work(&local->hw, &ifmsh->work);
}

/**
 * mesh_matches_local - check if the config of a mesh point matches ours
 *
 * @ie: information elements of a management frame from the mesh peer
 * @sdata: local mesh subif
 *
 * This function checks if the mesh configuration of a mesh point matches the
 * local mesh configuration, i.e. if both nodes belong to the same mesh network.
 */
bool mesh_matches_local(struct ieee802_11_elems *ie, struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

        /*
         * As support for each feature is added, check for matching
         * - On mesh config capabilities
         *   - Power Save Support En
         *   - Sync support enabled
         *   - Sync support active
         *   - Sync support required from peer
         *   - MDA enabled
         * - Power management control on fc
         */
        if (ifmsh->mesh_id_len == ie->mesh_id_len &&
                memcmp(ifmsh->mesh_id, ie->mesh_id, ie->mesh_id_len) == 0 &&
                (ifmsh->mesh_pp_id == ie->mesh_config->meshconf_psel) &&
                (ifmsh->mesh_pm_id == ie->mesh_config->meshconf_pmetric) &&
                (ifmsh->mesh_cc_id == ie->mesh_config->meshconf_congest) &&
                (ifmsh->mesh_sp_id == ie->mesh_config->meshconf_synch) &&
                (ifmsh->mesh_auth_id == ie->mesh_config->meshconf_auth))
                return true;

        return false;
}

/**
 * mesh_peer_accepts_plinks - check if an mp is willing to establish peer links
 *
 * @ie: information elements of a management frame from the mesh peer
 */
bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie)
{
        return (ie->mesh_config->meshconf_cap &
            MESHCONF_CAPAB_ACCEPT_PLINKS) != 0;
}

/**
 * mesh_accept_plinks_update: update accepting_plink in local mesh beacons
 *
 * @sdata: mesh interface in which mesh beacons are going to be updated
 */
void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata)
{
        bool free_plinks;

        /* In case mesh_plink_free_count > 0 and mesh_plinktbl_capacity == 0,
         * the mesh interface might be able to establish plinks with peers that
         * are already on the table but are not on PLINK_ESTAB state. However,
         * in general the mesh interface is not accepting peer link requests
         * from new peers, and that must be reflected in the beacon
         */
        free_plinks = mesh_plink_availables(sdata);

        if (free_plinks != sdata->u.mesh.accepting_plinks)
                ieee80211_mesh_housekeeping_timer((unsigned long) sdata);
}

void mesh_ids_set_default(struct ieee80211_if_mesh *sta)
{
        sta->mesh_pp_id = 0;    /* HWMP */
        sta->mesh_pm_id = 0;    /* Airtime */
        sta->mesh_cc_id = 0;    /* Disabled */
        sta->mesh_sp_id = 0;    /* Neighbor Offset */
        sta->mesh_auth_id = 0;  /* Disabled */
}

int mesh_rmc_init(struct ieee80211_sub_if_data *sdata)
{
        int i;

        sdata->u.mesh.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL);
        if (!sdata->u.mesh.rmc)
                return -ENOMEM;
        sdata->u.mesh.rmc->idx_mask = RMC_BUCKETS - 1;
        for (i = 0; i < RMC_BUCKETS; i++)
                INIT_LIST_HEAD(&sdata->u.mesh.rmc->bucket[i].list);
        return 0;
}

void mesh_rmc_free(struct ieee80211_sub_if_data *sdata)
{
        struct mesh_rmc *rmc = sdata->u.mesh.rmc;
        struct rmc_entry *p, *n;
        int i;

        if (!sdata->u.mesh.rmc)
                return;

        for (i = 0; i < RMC_BUCKETS; i++)
                list_for_each_entry_safe(p, n, &rmc->bucket[i].list, list) {
                        list_del(&p->list);
                        kmem_cache_free(rm_cache, p);
                }

        kfree(rmc);
        sdata->u.mesh.rmc = NULL;
}

/**
 * mesh_rmc_check - Check frame in recent multicast cache and add if absent.
 *
 * @sa:         source address
 * @mesh_hdr:   mesh_header
 *
 * Returns: 0 if the frame is not in the cache, nonzero otherwise.
 *
 * Checks using the source address and the mesh sequence number if we have
 * received this frame lately. If the frame is not in the cache, it is added to
 * it.
 */
int mesh_rmc_check(u8 *sa, struct ieee80211s_hdr *mesh_hdr,
                   struct ieee80211_sub_if_data *sdata)
{
        struct mesh_rmc *rmc = sdata->u.mesh.rmc;
        u32 seqnum = 0;
        int entries = 0;
        u8 idx;
        struct rmc_entry *p, *n;

        /* Don't care about endianness since only match matters */
        memcpy(&seqnum, &mesh_hdr->seqnum, sizeof(mesh_hdr->seqnum));
        idx = le32_to_cpu(mesh_hdr->seqnum) & rmc->idx_mask;
        list_for_each_entry_safe(p, n, &rmc->bucket[idx].list, list) {
                ++entries;
                if (time_after(jiffies, p->exp_time) ||
                                (entries == RMC_QUEUE_MAX_LEN)) {
                        list_del(&p->list);
                        kmem_cache_free(rm_cache, p);
                        --entries;
                } else if ((seqnum == p->seqnum) &&
                           (memcmp(sa, p->sa, ETH_ALEN) == 0))
                        return -1;
        }

        p = kmem_cache_alloc(rm_cache, GFP_ATOMIC);
        if (!p) {
                printk(KERN_DEBUG "o11s: could not allocate RMC entry\n");
                return 0;
        }
        p->seqnum = seqnum;
        p->exp_time = jiffies + RMC_TIMEOUT;
        memcpy(p->sa, sa, ETH_ALEN);
        list_add(&p->list, &rmc->bucket[idx].list);
        return 0;
}

void mesh_mgmt_ies_add(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_supported_band *sband;
        u8 *pos;
        int len, i, rate;
        u8 neighbors;

        sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
        len = sband->n_bitrates;
        if (len > 8)
                len = 8;
        pos = skb_put(skb, len + 2);
        *pos++ = WLAN_EID_SUPP_RATES;
        *pos++ = len;
        for (i = 0; i < len; i++) {
                rate = sband->bitrates[i].bitrate;
                *pos++ = (u8) (rate / 5);
        }

        if (sband->n_bitrates > len) {
                pos = skb_put(skb, sband->n_bitrates - len + 2);
                *pos++ = WLAN_EID_EXT_SUPP_RATES;
                *pos++ = sband->n_bitrates - len;
                for (i = len; i < sband->n_bitrates; i++) {
                        rate = sband->bitrates[i].bitrate;
                        *pos++ = (u8) (rate / 5);
                }
        }

        if (sband->band == IEEE80211_BAND_2GHZ) {
                pos = skb_put(skb, 2 + 1);
                *pos++ = WLAN_EID_DS_PARAMS;
                *pos++ = 1;
                *pos++ = ieee80211_frequency_to_channel(local->hw.conf.channel->center_freq);
        }

        pos = skb_put(skb, 2 + sdata->u.mesh.mesh_id_len);
        *pos++ = WLAN_EID_MESH_ID;
        *pos++ = sdata->u.mesh.mesh_id_len;
        if (sdata->u.mesh.mesh_id_len)
                memcpy(pos, sdata->u.mesh.mesh_id, sdata->u.mesh.mesh_id_len);

        pos = skb_put(skb, 2 + sizeof(struct ieee80211_meshconf_ie));
        *pos++ = WLAN_EID_MESH_CONFIG;
        *pos++ = sizeof(struct ieee80211_meshconf_ie);

        /* Active path selection protocol ID */
        *pos++ = sdata->u.mesh.mesh_pp_id;

        /* Active path selection metric ID   */
        *pos++ = sdata->u.mesh.mesh_pm_id;

        /* Congestion control mode identifier */
        *pos++ = sdata->u.mesh.mesh_cc_id;

        /* Synchronization protocol identifier */
        *pos++ = sdata->u.mesh.mesh_sp_id;

        /* Authentication Protocol identifier */
        *pos++ = sdata->u.mesh.mesh_auth_id;

        /* Mesh Formation Info - number of neighbors */
        neighbors = atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
        /* Number of neighbor mesh STAs or 15 whichever is smaller */
        neighbors = (neighbors > 15) ? 15 : neighbors;
        *pos++ = neighbors << 1;

        /* Mesh capability */
        sdata->u.mesh.accepting_plinks = mesh_plink_availables(sdata);
        *pos = MESHCONF_CAPAB_FORWARDING;
        *pos++ |= sdata->u.mesh.accepting_plinks ?
            MESHCONF_CAPAB_ACCEPT_PLINKS : 0x00;
        *pos++ = 0x00;

        return;
}

u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata, struct mesh_table *tbl)
{
        /* Use last four bytes of hw addr and interface index as hash index */
        return jhash_2words(*(u32 *)(addr+2), sdata->dev->ifindex, tbl->hash_rnd)
                & tbl->hash_mask;
}

struct mesh_table *mesh_table_alloc(int size_order)
{
        int i;
        struct mesh_table *newtbl;

        newtbl = kmalloc(sizeof(struct mesh_table), GFP_KERNEL);
        if (!newtbl)
                return NULL;

        newtbl->hash_buckets = kzalloc(sizeof(struct hlist_head) *
                        (1 << size_order), GFP_KERNEL);

        if (!newtbl->hash_buckets) {
                kfree(newtbl);
                return NULL;
        }

        newtbl->hashwlock = kmalloc(sizeof(spinlock_t) *
                        (1 << size_order), GFP_KERNEL);
        if (!newtbl->hashwlock) {
                kfree(newtbl->hash_buckets);
                kfree(newtbl);
                return NULL;
        }

        newtbl->size_order = size_order;
        newtbl->hash_mask = (1 << size_order) - 1;
        atomic_set(&newtbl->entries,  0);
        get_random_bytes(&newtbl->hash_rnd,
                        sizeof(newtbl->hash_rnd));
        for (i = 0; i <= newtbl->hash_mask; i++)
                spin_lock_init(&newtbl->hashwlock[i]);

        return newtbl;
}


static void ieee80211_mesh_path_timer(unsigned long data)
{
        struct ieee80211_sub_if_data *sdata =
                (struct ieee80211_sub_if_data *) data;
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
        struct ieee80211_local *local = sdata->local;

        if (local->quiescing) {
                set_bit(TMR_RUNNING_MP, &ifmsh->timers_running);
                return;
        }

        ieee80211_queue_work(&local->hw, &ifmsh->work);
}

static void ieee80211_mesh_path_root_timer(unsigned long data)
{
        struct ieee80211_sub_if_data *sdata =
                (struct ieee80211_sub_if_data *) data;
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
        struct ieee80211_local *local = sdata->local;

        set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);

        if (local->quiescing) {
                set_bit(TMR_RUNNING_MPR, &ifmsh->timers_running);
                return;
        }

        ieee80211_queue_work(&local->hw, &ifmsh->work);
}

void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh)
{
        if (ifmsh->mshcfg.dot11MeshHWMPRootMode)
                set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
        else {
                clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
                /* stop running timer */
                del_timer_sync(&ifmsh->mesh_path_root_timer);
        }
}

/**
 * ieee80211_fill_mesh_addresses - fill addresses of a locally originated mesh frame
 * @hdr:        802.11 frame header
 * @fc:         frame control field
 * @meshda:     destination address in the mesh
 * @meshsa:     source address address in the mesh.  Same as TA, as frame is
 *              locally originated.
 *
 * Return the length of the 802.11 (does not include a mesh control header)
 */
int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
                                  const u8 *meshda, const u8 *meshsa)
{
        if (is_multicast_ether_addr(meshda)) {
                *fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
                /* DA TA SA */
                memcpy(hdr->addr1, meshda, ETH_ALEN);
                memcpy(hdr->addr2, meshsa, ETH_ALEN);
                memcpy(hdr->addr3, meshsa, ETH_ALEN);
                return 24;
        } else {
                *fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
                                IEEE80211_FCTL_TODS);
                /* RA TA DA SA */
                memset(hdr->addr1, 0, ETH_ALEN);   /* RA is resolved later */
                memcpy(hdr->addr2, meshsa, ETH_ALEN);
                memcpy(hdr->addr3, meshda, ETH_ALEN);
                memcpy(hdr->addr4, meshsa, ETH_ALEN);
                return 30;
        }
}

/**
 * ieee80211_new_mesh_header - create a new mesh header
 * @meshhdr:    uninitialized mesh header
 * @sdata:      mesh interface to be used
 * @addr4:      addr4 of the mesh frame (1st in ae header)
 *              may be NULL
 * @addr5:      addr5 of the mesh frame (1st or 2nd in ae header)
 *              may be NULL unless addr6 is present
 * @addr6:      addr6 of the mesh frame (2nd or 3rd in ae header)
 *              may be NULL unless addr5 is present
 *
 * Return the header length.
 */
int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
                struct ieee80211_sub_if_data *sdata, char *addr4,
                char *addr5, char *addr6)
{
        int aelen = 0;
        memset(meshhdr, 0, sizeof(*meshhdr));
        meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
        put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);
        sdata->u.mesh.mesh_seqnum++;
        if (addr4) {
                meshhdr->flags |= MESH_FLAGS_AE_A4;
                aelen += ETH_ALEN;
                memcpy(meshhdr->eaddr1, addr4, ETH_ALEN);
        }
        if (addr5 && addr6) {
                meshhdr->flags |= MESH_FLAGS_AE_A5_A6;
                aelen += 2 * ETH_ALEN;
                if (!addr4) {
                        memcpy(meshhdr->eaddr1, addr5, ETH_ALEN);
                        memcpy(meshhdr->eaddr2, addr6, ETH_ALEN);
                } else {
                        memcpy(meshhdr->eaddr2, addr5, ETH_ALEN);
                        memcpy(meshhdr->eaddr3, addr6, ETH_ALEN);
                }
        }
        return 6 + aelen;
}

static void ieee80211_mesh_housekeeping(struct ieee80211_sub_if_data *sdata,
                           struct ieee80211_if_mesh *ifmsh)
{
        bool free_plinks;

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
        printk(KERN_DEBUG "%s: running mesh housekeeping\n",
               sdata->dev->name);
#endif

        ieee80211_sta_expire(sdata, IEEE80211_MESH_PEER_INACTIVITY_LIMIT);
        mesh_path_expire(sdata);

        free_plinks = mesh_plink_availables(sdata);
        if (free_plinks != sdata->u.mesh.accepting_plinks)
                ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);

        mod_timer(&ifmsh->housekeeping_timer,
                  round_jiffies(jiffies + IEEE80211_MESH_HOUSEKEEPING_INTERVAL));
}

static void ieee80211_mesh_rootpath(struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

        mesh_path_tx_root_frame(sdata);
        mod_timer(&ifmsh->mesh_path_root_timer,
                  round_jiffies(jiffies + IEEE80211_MESH_RANN_INTERVAL));
}

#ifdef CONFIG_PM
void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

        /* might restart the timer but that doesn't matter */
        cancel_work_sync(&ifmsh->work);

        /* use atomic bitops in case both timers fire at the same time */

        if (del_timer_sync(&ifmsh->housekeeping_timer))
                set_bit(TMR_RUNNING_HK, &ifmsh->timers_running);
        if (del_timer_sync(&ifmsh->mesh_path_timer))
                set_bit(TMR_RUNNING_MP, &ifmsh->timers_running);
        if (del_timer_sync(&ifmsh->mesh_path_root_timer))
                set_bit(TMR_RUNNING_MPR, &ifmsh->timers_running);
}

void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

        if (test_and_clear_bit(TMR_RUNNING_HK, &ifmsh->timers_running))
                add_timer(&ifmsh->housekeeping_timer);
        if (test_and_clear_bit(TMR_RUNNING_MP, &ifmsh->timers_running))
                add_timer(&ifmsh->mesh_path_timer);
        if (test_and_clear_bit(TMR_RUNNING_MPR, &ifmsh->timers_running))
                add_timer(&ifmsh->mesh_path_root_timer);
        ieee80211_mesh_root_setup(ifmsh);
}
#endif

void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
        struct ieee80211_local *local = sdata->local;

        set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
        ieee80211_mesh_root_setup(ifmsh);
        ieee80211_queue_work(&local->hw, &ifmsh->work);
        sdata->vif.bss_conf.beacon_int = MESH_DEFAULT_BEACON_INTERVAL;
        ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON |
                                                BSS_CHANGED_BEACON_ENABLED |
                                                BSS_CHANGED_BEACON_INT);
}

void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
{
        del_timer_sync(&sdata->u.mesh.housekeeping_timer);
        del_timer_sync(&sdata->u.mesh.mesh_path_root_timer);
        /*
         * If the timer fired while we waited for it, it will have
         * requeued the work. Now the work will be running again
         * but will not rearm the timer again because it checks
         * whether the interface is running, which, at this point,
         * it no longer is.
         */
        cancel_work_sync(&sdata->u.mesh.work);

        /*
         * 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.
         */
        rcu_barrier(); /* Wait for RX path and call_rcu()'s */
        skb_queue_purge(&sdata->u.mesh.skb_queue);
}

static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
                                        u16 stype,
                                        struct ieee80211_mgmt *mgmt,
                                        size_t len,
                                        struct ieee80211_rx_status *rx_status)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee802_11_elems elems;
        struct ieee80211_channel *channel;
        u32 supp_rates = 0;
        size_t baselen;
        int freq;
        enum ieee80211_band band = rx_status->band;

        /* ignore ProbeResp to foreign address */
        if (stype == IEEE80211_STYPE_PROBE_RESP &&
            compare_ether_addr(mgmt->da, sdata->dev->dev_addr))
                return;

        baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
        if (baselen > len)
                return;

        ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
                               &elems);

        if (elems.ds_params && elems.ds_params_len == 1)
                freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
        else
                freq = rx_status->freq;

        channel = ieee80211_get_channel(local->hw.wiphy, freq);

        if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
                return;

        if (elems.mesh_id && elems.mesh_config &&
            mesh_matches_local(&elems, sdata)) {
                supp_rates = ieee80211_sta_get_rates(local, &elems, band);

                mesh_neighbour_update(mgmt->sa, supp_rates, sdata,
                                      mesh_peer_accepts_plinks(&elems));
        }
}

static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
                                          struct ieee80211_mgmt *mgmt,
                                          size_t len,
                                          struct ieee80211_rx_status *rx_status)
{
        switch (mgmt->u.action.category) {
        case MESH_PLINK_CATEGORY:
                mesh_rx_plink_frame(sdata, mgmt, len, rx_status);
                break;
        case MESH_PATH_SEL_CATEGORY:
                mesh_rx_path_sel_frame(sdata, mgmt, len);
                break;
        }
}

static void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
                                          struct sk_buff *skb)
{
        struct ieee80211_rx_status *rx_status;
        struct ieee80211_if_mesh *ifmsh;
        struct ieee80211_mgmt *mgmt;
        u16 stype;

        ifmsh = &sdata->u.mesh;

        rx_status = IEEE80211_SKB_RXCB(skb);
        mgmt = (struct ieee80211_mgmt *) skb->data;
        stype = le16_to_cpu(mgmt->frame_control) & IEEE80211_FCTL_STYPE;

        switch (stype) {
        case IEEE80211_STYPE_PROBE_RESP:
        case IEEE80211_STYPE_BEACON:
                ieee80211_mesh_rx_bcn_presp(sdata, stype, mgmt, skb->len,
                                            rx_status);
                break;
        case IEEE80211_STYPE_ACTION:
                ieee80211_mesh_rx_mgmt_action(sdata, mgmt, skb->len, rx_status);
                break;
        }

        kfree_skb(skb);
}

static void ieee80211_mesh_work(struct work_struct *work)
{
        struct ieee80211_sub_if_data *sdata =
                container_of(work, struct ieee80211_sub_if_data, u.mesh.work);
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
        struct sk_buff *skb;

        if (!netif_running(sdata->dev))
                return;

        if (local->scanning)
                return;

        while ((skb = skb_dequeue(&ifmsh->skb_queue)))
                ieee80211_mesh_rx_queued_mgmt(sdata, skb);

        if (ifmsh->preq_queue_len &&
            time_after(jiffies,
                       ifmsh->last_preq + msecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval)))
                mesh_path_start_discovery(sdata);

        if (test_and_clear_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags))
                mesh_mpath_table_grow();

        if (test_and_clear_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags))
                mesh_mpp_table_grow();

        if (test_and_clear_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags))
                ieee80211_mesh_housekeeping(sdata, ifmsh);

        if (test_and_clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags))
                ieee80211_mesh_rootpath(sdata);
}

void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local)
{
        struct ieee80211_sub_if_data *sdata;

        rcu_read_lock();
        list_for_each_entry_rcu(sdata, &local->interfaces, list)
                if (ieee80211_vif_is_mesh(&sdata->vif))
                        ieee80211_queue_work(&local->hw, &sdata->u.mesh.work);
        rcu_read_unlock();
}

void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

        INIT_WORK(&ifmsh->work, ieee80211_mesh_work);
        setup_timer(&ifmsh->housekeeping_timer,
                    ieee80211_mesh_housekeeping_timer,
                    (unsigned long) sdata);
        skb_queue_head_init(&sdata->u.mesh.skb_queue);

        ifmsh->mshcfg.dot11MeshRetryTimeout = MESH_RET_T;
        ifmsh->mshcfg.dot11MeshConfirmTimeout = MESH_CONF_T;
        ifmsh->mshcfg.dot11MeshHoldingTimeout = MESH_HOLD_T;
        ifmsh->mshcfg.dot11MeshMaxRetries = MESH_MAX_RETR;
        ifmsh->mshcfg.dot11MeshTTL = MESH_TTL;
        ifmsh->mshcfg.auto_open_plinks = true;
        ifmsh->mshcfg.dot11MeshMaxPeerLinks =
                MESH_MAX_ESTAB_PLINKS;
        ifmsh->mshcfg.dot11MeshHWMPactivePathTimeout =
                MESH_PATH_TIMEOUT;
        ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval =
                MESH_PREQ_MIN_INT;
        ifmsh->mshcfg.dot11MeshHWMPnetDiameterTraversalTime =
                MESH_DIAM_TRAVERSAL_TIME;
        ifmsh->mshcfg.dot11MeshHWMPmaxPREQretries =
                MESH_MAX_PREQ_RETRIES;
        ifmsh->mshcfg.path_refresh_time =
                MESH_PATH_REFRESH_TIME;
        ifmsh->mshcfg.min_discovery_timeout =
                MESH_MIN_DISCOVERY_TIMEOUT;
        ifmsh->accepting_plinks = true;
        ifmsh->preq_id = 0;
        ifmsh->sn = 0;
        atomic_set(&ifmsh->mpaths, 0);
        mesh_rmc_init(sdata);
        ifmsh->last_preq = jiffies;
        /* Allocate all mesh structures when creating the first mesh interface. */
        if (!mesh_allocated)
                ieee80211s_init();
        mesh_ids_set_default(ifmsh);
        setup_timer(&ifmsh->mesh_path_timer,
                    ieee80211_mesh_path_timer,
                    (unsigned long) sdata);
        setup_timer(&ifmsh->mesh_path_root_timer,
                    ieee80211_mesh_path_root_timer,
                    (unsigned long) sdata);
        INIT_LIST_HEAD(&ifmsh->preq_queue.list);
        spin_lock_init(&ifmsh->mesh_preq_queue_lock);
}

ieee80211_rx_result
ieee80211_mesh_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
        struct ieee80211_mgmt *mgmt;
        u16 fc;

        if (skb->len < 24)
                return RX_DROP_MONITOR;

        mgmt = (struct ieee80211_mgmt *) skb->data;
        fc = le16_to_cpu(mgmt->frame_control);

        switch (fc & IEEE80211_FCTL_STYPE) {
        case IEEE80211_STYPE_ACTION:
                if (skb->len < IEEE80211_MIN_ACTION_SIZE)
                        return RX_DROP_MONITOR;
                /* fall through */
        case IEEE80211_STYPE_PROBE_RESP:
        case IEEE80211_STYPE_BEACON:
                skb_queue_tail(&ifmsh->skb_queue, skb);
                ieee80211_queue_work(&local->hw, &ifmsh->work);
                return RX_QUEUED;
        }

        return RX_CONTINUE;
}