mesh.c

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/*
 * 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 <linux/slab.h>
#include <asm/unaligned.h>
#include "ieee80211_i.h"
#include "mesh.h"

#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;

#ifdef CONFIG_MAC80211_MESH
bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt)
{
        return (mgmt->u.action.u.mesh_action.action_code ==
                        WLAN_MESH_ACTION_HWMP_PATH_SELECTION);
}
#else
bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt)
{ return false; }
#endif

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, &sdata->work);
}

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;
}

bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie)
{
        return (ie->mesh_config->meshconf_cap &
            MESHCONF_CAPAB_ACCEPT_PLINKS) != 0;
}

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);
}

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;
}

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)
                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;
}

int
mesh_add_meshconf_ie(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
        u8 *pos, neighbors;
        u8 meshconf_len = sizeof(struct ieee80211_meshconf_ie);

        if (skb_tailroom(skb) < 2 + meshconf_len)
                return -ENOMEM;

        pos = skb_put(skb, 2 + meshconf_len);
        *pos++ = WLAN_EID_MESH_CONFIG;
        *pos++ = meshconf_len;

        /* Active path selection protocol ID */
        *pos++ = ifmsh->mesh_pp_id;
        /* Active path selection metric ID   */
        *pos++ = ifmsh->mesh_pm_id;
        /* Congestion control mode identifier */
        *pos++ = ifmsh->mesh_cc_id;
        /* Synchronization protocol identifier */
        *pos++ = ifmsh->mesh_sp_id;
        /* Authentication Protocol identifier */
        *pos++ = ifmsh->mesh_auth_id;
        /* Mesh Formation Info - number of neighbors */
        neighbors = atomic_read(&ifmsh->mshstats.estab_plinks);
        /* Number of neighbor mesh STAs or 15 whichever is smaller */
        neighbors = (neighbors > 15) ? 15 : neighbors;
        *pos++ = neighbors << 1;
        /* Mesh capability */
        ifmsh->accepting_plinks = mesh_plink_availables(sdata);
        *pos = MESHCONF_CAPAB_FORWARDING;
        *pos++ |= ifmsh->accepting_plinks ?
            MESHCONF_CAPAB_ACCEPT_PLINKS : 0x00;
        *pos++ = 0x00;

        return 0;
}

int
mesh_add_meshid_ie(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
        u8 *pos;

        if (skb_tailroom(skb) < 2 + ifmsh->mesh_id_len)
                return -ENOMEM;

        pos = skb_put(skb, 2 + ifmsh->mesh_id_len);
        *pos++ = WLAN_EID_MESH_ID;
        *pos++ = ifmsh->mesh_id_len;
        if (ifmsh->mesh_id_len)
                memcpy(pos, ifmsh->mesh_id, ifmsh->mesh_id_len);

        return 0;
}

int
mesh_add_vendor_ies(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
        u8 offset, len;
        const u8 *data;

        if (!ifmsh->ie || !ifmsh->ie_len)
                return 0;

        /* fast-forward to vendor IEs */
        offset = ieee80211_ie_split_vendor(ifmsh->ie, ifmsh->ie_len, 0);

        if (offset) {
                len = ifmsh->ie_len - offset;
                data = ifmsh->ie + offset;
                if (skb_tailroom(skb) < len)
                        return -ENOMEM;
                memcpy(skb_put(skb, len), data, len);
        }

        return 0;
}

int
mesh_add_rsn_ie(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
        u8 len = 0;
        const u8 *data;

        if (!ifmsh->ie || !ifmsh->ie_len)
                return 0;

        /* find RSN IE */
        data = ifmsh->ie;
        while (data < ifmsh->ie + ifmsh->ie_len) {
                if (*data == WLAN_EID_RSN) {
                        len = data[1] + 2;
                        break;
                }
                data++;
        }

        if (len) {
                if (skb_tailroom(skb) < len)
                        return -ENOMEM;
                memcpy(skb_put(skb, len), data, len);
        }

        return 0;
}

int mesh_add_ds_params_ie(struct sk_buff *skb,
                          struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_supported_band *sband;
        u8 *pos;

        if (skb_tailroom(skb) < 3)
                return -ENOMEM;

        sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
        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);
        }

        return 0;
}

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, &sdata->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, &sdata->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);
        }
}

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;
        }
}

int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
                struct ieee80211_sub_if_data *sdata, char *addr4or5,
                char *addr6)
{
        int aelen = 0;
        BUG_ON(!addr4or5 && addr6);
        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 (addr4or5 && !addr6) {
                meshhdr->flags |= MESH_FLAGS_AE_A4;
                aelen += ETH_ALEN;
                memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
        } else if (addr4or5 && addr6) {
                meshhdr->flags |= MESH_FLAGS_AE_A5_A6;
                aelen += 2 * ETH_ALEN;
                memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
                memcpy(meshhdr->eaddr2, 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->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(TU_TO_EXP_TIME(
                                  ifmsh->mshcfg.dot11MeshHWMPRannInterval)));
}

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

        /* use atomic bitops in case all 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;

        local->fif_other_bss++;
        /* mesh ifaces must set allmulti to forward mcast traffic */
        atomic_inc(&local->iff_allmultis);
        ieee80211_configure_filter(local);

        ifmsh->mesh_cc_id = 0;  /* Disabled */
        ifmsh->mesh_sp_id = 0;  /* Neighbor Offset */
        ifmsh->mesh_auth_id = 0;        /* Disabled */
        set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
        ieee80211_mesh_root_setup(ifmsh);
        ieee80211_queue_work(&local->hw, &sdata->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)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

        ifmsh->mesh_id_len = 0;
        ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
        sta_info_flush(local, NULL);

        del_timer_sync(&sdata->u.mesh.housekeeping_timer);
        del_timer_sync(&sdata->u.mesh.mesh_path_root_timer);
        del_timer_sync(&sdata->u.mesh.mesh_path_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->work);

        local->fif_other_bss--;
        atomic_dec(&local->iff_allmultis);
        ieee80211_configure_filter(local);
}

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->vif.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);

        /* ignore beacons from secure mesh peers if our security is off */
        if (elems.rsn_len && sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE)
                return;

        if (elems.ds_params && elems.ds_params_len == 1)
                freq = ieee80211_channel_to_frequency(elems.ds_params[0], band);
        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, &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 WLAN_CATEGORY_SELF_PROTECTED:
                switch (mgmt->u.action.u.self_prot.action_code) {
                case WLAN_SP_MESH_PEERING_OPEN:
                case WLAN_SP_MESH_PEERING_CLOSE:
                case WLAN_SP_MESH_PEERING_CONFIRM:
                        mesh_rx_plink_frame(sdata, mgmt, len, rx_status);
                        break;
                }
                break;
        case WLAN_CATEGORY_MESH_ACTION:
                if (mesh_action_is_path_sel(mgmt))
                        mesh_rx_path_sel_frame(sdata, mgmt, len);
                break;
        }
}

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

        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;
        }
}

void ieee80211_mesh_work(struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

        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_MPP_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->work);
        rcu_read_unlock();
}

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

        setup_timer(&ifmsh->housekeeping_timer,
                    ieee80211_mesh_housekeeping_timer,
                    (unsigned long) sdata);

        ifmsh->accepting_plinks = true;
        ifmsh->preq_id = 0;
        ifmsh->sn = 0;
        ifmsh->num_gates = 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();
        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);
}