/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2009 The FreeBSD Foundation
 *
 * This software was developed by Rui Paulo under sponsorship from the
 * FreeBSD Foundation.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * IEEE 802.11s Hybrid Wireless Mesh Protocol, HWMP.
 *
 * Based on March 2009, D3.0 802.11s draft spec.
 */
#include "opt_inet.h"
#include "opt_wlan.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/kernel.h>

#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/endian.h>
#include <sys/errno.h>
#include <sys/proc.h>
#include <sys/sysctl.h>

#include <net/if.h>
#include <net/if_media.h>
#include <net/if_llc.h>
#include <net/ethernet.h>

#include <net/bpf.h>

#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_action.h>
#include <net80211/ieee80211_input.h>
#include <net80211/ieee80211_mesh.h>

static void     hwmp_vattach(struct ieee80211vap *);
static void     hwmp_vdetach(struct ieee80211vap *);
static int      hwmp_newstate(struct ieee80211vap *,
                    enum ieee80211_state, int);
static int      hwmp_send_action(struct ieee80211vap *,
                    const uint8_t [IEEE80211_ADDR_LEN],
                    uint8_t *, size_t);
static uint8_t * hwmp_add_meshpreq(uint8_t *,
                    const struct ieee80211_meshpreq_ie *);
static uint8_t * hwmp_add_meshprep(uint8_t *,
                    const struct ieee80211_meshprep_ie *);
static uint8_t * hwmp_add_meshperr(uint8_t *,
                    const struct ieee80211_meshperr_ie *);
static uint8_t * hwmp_add_meshrann(uint8_t *,
                    const struct ieee80211_meshrann_ie *);
static void     hwmp_rootmode_setup(struct ieee80211vap *);
static void     hwmp_rootmode_cb(void *);
static void     hwmp_rootmode_rann_cb(void *);
static void     hwmp_recv_preq(struct ieee80211vap *, struct ieee80211_node *,
                    const struct ieee80211_frame *,
                    const struct ieee80211_meshpreq_ie *);
static int      hwmp_send_preq(struct ieee80211vap *,
                    const uint8_t [IEEE80211_ADDR_LEN],
                    struct ieee80211_meshpreq_ie *,
                    struct timeval *, struct timeval *);
static void     hwmp_recv_prep(struct ieee80211vap *, struct ieee80211_node *,
                    const struct ieee80211_frame *,
                    const struct ieee80211_meshprep_ie *);
static int      hwmp_send_prep(struct ieee80211vap *,
                    const uint8_t [IEEE80211_ADDR_LEN],
                    struct ieee80211_meshprep_ie *);
static void     hwmp_recv_perr(struct ieee80211vap *, struct ieee80211_node *,
                    const struct ieee80211_frame *,
                    const struct ieee80211_meshperr_ie *);
static int      hwmp_send_perr(struct ieee80211vap *,
                    const uint8_t [IEEE80211_ADDR_LEN],
                    struct ieee80211_meshperr_ie *);
static void     hwmp_senderror(struct ieee80211vap *,
                    const uint8_t [IEEE80211_ADDR_LEN],
                    struct ieee80211_mesh_route *, int);
static void     hwmp_recv_rann(struct ieee80211vap *, struct ieee80211_node *,
                   const struct ieee80211_frame *,
                   const struct ieee80211_meshrann_ie *);
static int      hwmp_send_rann(struct ieee80211vap *,
                    const uint8_t [IEEE80211_ADDR_LEN],
                    struct ieee80211_meshrann_ie *);
static struct ieee80211_node *
                hwmp_discover(struct ieee80211vap *,
                    const uint8_t [IEEE80211_ADDR_LEN], struct mbuf *);
static void     hwmp_peerdown(struct ieee80211_node *);

static struct timeval ieee80211_hwmp_preqminint = { 0, 100000 };
static struct timeval ieee80211_hwmp_perrminint = { 0, 100000 };

/* NB: the Target Address set in a Proactive PREQ is the broadcast address. */
static const uint8_t    broadcastaddr[IEEE80211_ADDR_LEN] =
        { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };

typedef uint32_t ieee80211_hwmp_seq;
#define HWMP_SEQ_LT(a, b)       ((int32_t)((a)-(b)) < 0)
#define HWMP_SEQ_LEQ(a, b)      ((int32_t)((a)-(b)) <= 0)
#define HWMP_SEQ_EQ(a, b)       ((int32_t)((a)-(b)) == 0)
#define HWMP_SEQ_GT(a, b)       ((int32_t)((a)-(b)) > 0)

#define HWMP_SEQ_MAX(a, b)      (a > b ? a : b)

/*
 * Private extension of ieee80211_mesh_route.
 */
struct ieee80211_hwmp_route {
        ieee80211_hwmp_seq      hr_seq;         /* last HWMP seq seen from dst*/
        ieee80211_hwmp_seq      hr_preqid;      /* last PREQ ID seen from dst */
        ieee80211_hwmp_seq      hr_origseq;     /* seq. no. on our latest PREQ*/
        struct timeval          hr_lastpreq;    /* last time we sent a PREQ */
        struct timeval          hr_lastrootconf; /* last sent PREQ root conf */
        int                     hr_preqretries; /* number of discoveries */
        int                     hr_lastdiscovery; /* last discovery in ticks */
};
struct ieee80211_hwmp_state {
        ieee80211_hwmp_seq      hs_seq;         /* next seq to be used */
        ieee80211_hwmp_seq      hs_preqid;      /* next PREQ ID to be used */
        int                     hs_rootmode;    /* proactive HWMP */
        struct timeval          hs_lastperr;    /* last time we sent a PERR */
        struct callout          hs_roottimer;
        uint8_t                 hs_maxhops;     /* max hop count */
};

static SYSCTL_NODE(_net_wlan, OID_AUTO, hwmp, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
    "IEEE 802.11s HWMP parameters");
static int      ieee80211_hwmp_targetonly = 0;
SYSCTL_INT(_net_wlan_hwmp, OID_AUTO, targetonly, CTLFLAG_RW,
    &ieee80211_hwmp_targetonly, 0, "Set TO bit on generated PREQs");
static int      ieee80211_hwmp_pathtimeout = -1;
SYSCTL_PROC(_net_wlan_hwmp, OID_AUTO, pathlifetime,
    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
    &ieee80211_hwmp_pathtimeout, 0, ieee80211_sysctl_msecs_ticks, "I",
    "path entry lifetime (ms)");
static int      ieee80211_hwmp_maxpreq_retries = -1;
SYSCTL_PROC(_net_wlan_hwmp, OID_AUTO, maxpreq_retries,
    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
    &ieee80211_hwmp_maxpreq_retries, 0, ieee80211_sysctl_msecs_ticks, "I",
    "maximum number of preq retries");
static int      ieee80211_hwmp_net_diameter_traversaltime = -1;
SYSCTL_PROC(_net_wlan_hwmp, OID_AUTO, net_diameter_traversal_time,
    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
    &ieee80211_hwmp_net_diameter_traversaltime, 0,
    ieee80211_sysctl_msecs_ticks, "I",
    "estimate traversal time across the MBSS (ms)");
static int      ieee80211_hwmp_roottimeout = -1;
SYSCTL_PROC(_net_wlan_hwmp, OID_AUTO, roottimeout,
    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
    &ieee80211_hwmp_roottimeout, 0, ieee80211_sysctl_msecs_ticks, "I",
    "root PREQ timeout (ms)");
static int      ieee80211_hwmp_rootint = -1;
SYSCTL_PROC(_net_wlan_hwmp, OID_AUTO, rootint,
    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
    &ieee80211_hwmp_rootint, 0, ieee80211_sysctl_msecs_ticks, "I",
    "root interval (ms)");
static int      ieee80211_hwmp_rannint = -1;
SYSCTL_PROC(_net_wlan_hwmp, OID_AUTO, rannint,
    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
    &ieee80211_hwmp_rannint, 0, ieee80211_sysctl_msecs_ticks, "I",
    "root announcement interval (ms)");
static struct timeval ieee80211_hwmp_rootconfint = { 0, 0 };
static int      ieee80211_hwmp_rootconfint_internal = -1;
SYSCTL_PROC(_net_wlan_hwmp, OID_AUTO, rootconfint,
    CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
    &ieee80211_hwmp_rootconfint_internal, 0, ieee80211_sysctl_msecs_ticks, "I",
    "root confirmation interval (ms) (read-only)");

#define IEEE80211_HWMP_DEFAULT_MAXHOPS  31

static  ieee80211_recv_action_func hwmp_recv_action_meshpath;

static struct ieee80211_mesh_proto_path mesh_proto_hwmp = {
        .mpp_descr      = "HWMP",
        .mpp_ie         = IEEE80211_MESHCONF_PATH_HWMP,
        .mpp_discover   = hwmp_discover,
        .mpp_peerdown   = hwmp_peerdown,
        .mpp_senderror  = hwmp_senderror,
        .mpp_vattach    = hwmp_vattach,
        .mpp_vdetach    = hwmp_vdetach,
        .mpp_newstate   = hwmp_newstate,
        .mpp_privlen    = sizeof(struct ieee80211_hwmp_route),
};
SYSCTL_PROC(_net_wlan_hwmp, OID_AUTO, inact,
    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
    &mesh_proto_hwmp.mpp_inact, 0, ieee80211_sysctl_msecs_ticks, "I",
    "mesh route inactivity timeout (ms)");

static void
ieee80211_hwmp_init(void *dummy __unused)
{
        /* Default values as per amendment */
        ieee80211_hwmp_pathtimeout = msecs_to_ticks(5*1000);
        ieee80211_hwmp_roottimeout = msecs_to_ticks(5*1000);
        ieee80211_hwmp_rootint = msecs_to_ticks(2*1000);
        ieee80211_hwmp_rannint = msecs_to_ticks(1*1000);
        ieee80211_hwmp_rootconfint_internal = msecs_to_ticks(2*1000);
        ieee80211_hwmp_maxpreq_retries = 3;
        /*
         * (TU): A measurement of time equal to 1024 μs,
         * 500 TU is 512 ms.
         */
        ieee80211_hwmp_net_diameter_traversaltime = msecs_to_ticks(512);

        /*
         * NB: I dont know how to make SYSCTL_PROC that calls ms to ticks
         * and return a struct timeval...
         */
        ieee80211_hwmp_rootconfint.tv_usec =
            ieee80211_hwmp_rootconfint_internal * 1000;

        /*
         * Register action frame handler.
         */
        ieee80211_recv_action_register(IEEE80211_ACTION_CAT_MESH,
            IEEE80211_ACTION_MESH_HWMP, hwmp_recv_action_meshpath);

        /* NB: default is 5 secs per spec */
        mesh_proto_hwmp.mpp_inact = msecs_to_ticks(5*1000);

        /*
         * Register HWMP.
         */
        ieee80211_mesh_register_proto_path(&mesh_proto_hwmp);
}
SYSINIT(wlan_hwmp, SI_SUB_DRIVERS, SI_ORDER_SECOND, ieee80211_hwmp_init, NULL);

static void
hwmp_vattach(struct ieee80211vap *vap)
{
        struct ieee80211_hwmp_state *hs;

        KASSERT(vap->iv_opmode == IEEE80211_M_MBSS,
            ("not a mesh vap, opmode %d", vap->iv_opmode));

        hs = IEEE80211_MALLOC(sizeof(struct ieee80211_hwmp_state), M_80211_VAP,
            IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
        if (hs == NULL) {
                net80211_vap_printf(vap, "%s: couldn't alloc HWMP state\n",
                    __func__);
                return;
        }
        hs->hs_maxhops = IEEE80211_HWMP_DEFAULT_MAXHOPS;
        callout_init(&hs->hs_roottimer, 1);
        vap->iv_hwmp = hs;
}

static void
hwmp_vdetach(struct ieee80211vap *vap)
{
        struct ieee80211_hwmp_state *hs = vap->iv_hwmp;

        callout_drain(&hs->hs_roottimer);
        IEEE80211_FREE(vap->iv_hwmp, M_80211_VAP);
        vap->iv_hwmp = NULL;
}

static int
hwmp_newstate(struct ieee80211vap *vap, enum ieee80211_state ostate, int arg)
{
        enum ieee80211_state nstate = vap->iv_state;
        struct ieee80211_hwmp_state *hs = vap->iv_hwmp;

        IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
            __func__, ieee80211_state_name[ostate],
            ieee80211_state_name[nstate], arg);

        if (nstate != IEEE80211_S_RUN && ostate == IEEE80211_S_RUN)
                callout_drain(&hs->hs_roottimer);
        if (nstate == IEEE80211_S_RUN)
                hwmp_rootmode_setup(vap);
        return 0;
}

/*
 * Verify the length of an HWMP PREQ and return the number
 * of destinations >= 1, if verification fails -1 is returned.
 */
static int
verify_mesh_preq_len(struct ieee80211vap *vap,
    const struct ieee80211_frame *wh, const uint8_t *iefrm)
{
        int alloc_sz = -1;
        int ndest = -1;
        if (iefrm[2] & IEEE80211_MESHPREQ_FLAGS_AE) {
                /* Originator External Address  present */
                alloc_sz =  IEEE80211_MESHPREQ_BASE_SZ_AE;
                ndest = iefrm[IEEE80211_MESHPREQ_TCNT_OFFSET_AE];
        } else {
                /* w/o Originator External Address */
                alloc_sz =  IEEE80211_MESHPREQ_BASE_SZ;
                ndest = iefrm[IEEE80211_MESHPREQ_TCNT_OFFSET];
        }
        alloc_sz += ndest * IEEE80211_MESHPREQ_TRGT_SZ;

        if(iefrm[1] != (alloc_sz)) {
                IEEE80211_DISCARD(vap,
                    IEEE80211_MSG_ACTION | IEEE80211_MSG_HWMP,
                    wh, NULL, "PREQ (AE=%s) with wrong len",
                    iefrm[2] & IEEE80211_MESHPREQ_FLAGS_AE ? "1" : "0");
                return (-1);
        }
        return ndest;
}

/*
 * Verify the length of an HWMP PREP and returns 1 on success,
 * otherwise -1.
 */
static int
verify_mesh_prep_len(struct ieee80211vap *vap,
    const struct ieee80211_frame *wh, const uint8_t *iefrm)
{
        int alloc_sz = -1;
        if (iefrm[2] & IEEE80211_MESHPREP_FLAGS_AE) {
                if (iefrm[1] == IEEE80211_MESHPREP_BASE_SZ_AE)
                        alloc_sz = IEEE80211_MESHPREP_BASE_SZ_AE;
        } else if (iefrm[1] == IEEE80211_MESHPREP_BASE_SZ)
                alloc_sz = IEEE80211_MESHPREP_BASE_SZ;
        if(alloc_sz < 0) {
                IEEE80211_DISCARD(vap,
                    IEEE80211_MSG_ACTION | IEEE80211_MSG_HWMP,
                    wh, NULL, "PREP (AE=%s) with wrong len",
                    iefrm[2] & IEEE80211_MESHPREP_FLAGS_AE ? "1" : "0");
                return (-1);
        }
        return (1);
}

/*
 * Verify the length of an HWMP PERR and return the number
 * of destinations >= 1, if verification fails -1 is returned.
 */
static int
verify_mesh_perr_len(struct ieee80211vap *vap,
    const struct ieee80211_frame *wh, const uint8_t *iefrm)
{
        int alloc_sz = -1;
        const uint8_t *iefrm_t = iefrm;
        uint8_t ndest = iefrm_t[IEEE80211_MESHPERR_NDEST_OFFSET];
        int i;

        if(ndest > IEEE80211_MESHPERR_MAXDEST) {
                IEEE80211_DISCARD(vap,
                    IEEE80211_MSG_ACTION | IEEE80211_MSG_HWMP,
                    wh, NULL, "PERR with wrong number of destionat (>19), %u",
                    ndest);
                return (-1);
        }

        iefrm_t += IEEE80211_MESHPERR_NDEST_OFFSET + 1; /* flag is next field */
        /* We need to check each destination flag to know size */
        for(i = 0; i<ndest; i++) {
                if ((*iefrm_t) & IEEE80211_MESHPERR_FLAGS_AE)
                        iefrm_t += IEEE80211_MESHPERR_DEST_SZ_AE;
                else
                        iefrm_t += IEEE80211_MESHPERR_DEST_SZ;
        }

        alloc_sz = (iefrm_t - iefrm) - 2; /* action + code */
        if(alloc_sz !=  iefrm[1]) {
                IEEE80211_DISCARD(vap,
                    IEEE80211_MSG_ACTION | IEEE80211_MSG_HWMP,
                    wh, NULL, "%s", "PERR with wrong len");
                return (-1);
        }
        return ndest;
}

static int
hwmp_recv_action_meshpath(struct ieee80211_node *ni,
        const struct ieee80211_frame *wh,
        const uint8_t *frm, const uint8_t *efrm)
{
        struct ieee80211vap *vap = ni->ni_vap;
        struct ieee80211_meshpreq_ie *preq;
        struct ieee80211_meshprep_ie *prep;
        struct ieee80211_meshperr_ie *perr;
        struct ieee80211_meshrann_ie rann;
        const uint8_t *iefrm = frm + 2; /* action + code */
        const uint8_t *iefrm_t = iefrm; /* temporary pointer */
        int ndest = -1;
        int found = 0;

        while (efrm - iefrm > 1) {
                IEEE80211_VERIFY_LENGTH(efrm - iefrm, iefrm[1] + 2, return 0);
                switch (*iefrm) {
                case IEEE80211_ELEMID_MESHPREQ:
                {
                        int i = 0;

                        iefrm_t = iefrm;
                        ndest = verify_mesh_preq_len(vap, wh, iefrm_t);
                        if (ndest < 0) {
                                vap->iv_stats.is_rx_mgtdiscard++;
                                break;
                        }
                        preq = IEEE80211_MALLOC(sizeof(*preq) +
                            (ndest - 1) * sizeof(*preq->preq_targets),
                            M_80211_MESH_PREQ,
                            IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
                        KASSERT(preq != NULL, ("preq == NULL"));

                        preq->preq_ie = *iefrm_t++;
                        preq->preq_len = *iefrm_t++;
                        preq->preq_flags = *iefrm_t++;
                        preq->preq_hopcount = *iefrm_t++;
                        preq->preq_ttl = *iefrm_t++;
                        preq->preq_id = le32dec(iefrm_t); iefrm_t += 4;
                        IEEE80211_ADDR_COPY(preq->preq_origaddr, iefrm_t);
                        iefrm_t += 6;
                        preq->preq_origseq = le32dec(iefrm_t); iefrm_t += 4;
                        /* NB: may have Originator Proxied Address */
                        if (preq->preq_flags & IEEE80211_MESHPREQ_FLAGS_AE)  {
                                IEEE80211_ADDR_COPY(
                                    preq->preq_orig_ext_addr, iefrm_t);
                                iefrm_t += 6;
                        }
                        preq->preq_lifetime = le32dec(iefrm_t); iefrm_t += 4;
                        preq->preq_metric = le32dec(iefrm_t); iefrm_t += 4;
                        preq->preq_tcount = *iefrm_t++;

                        for (i = 0; i < preq->preq_tcount; i++) {
                                preq->preq_targets[i].target_flags = *iefrm_t++;
                                IEEE80211_ADDR_COPY(
                                    preq->preq_targets[i].target_addr, iefrm_t);
                                iefrm_t += 6;
                                preq->preq_targets[i].target_seq =
                                    le32dec(iefrm_t);
                                iefrm_t += 4;
                        }

                        hwmp_recv_preq(vap, ni, wh, preq);
                        IEEE80211_FREE(preq, M_80211_MESH_PREQ);
                        found++;
                        break;
                }
                case IEEE80211_ELEMID_MESHPREP:
                {
                        iefrm_t = iefrm;
                        ndest = verify_mesh_prep_len(vap, wh, iefrm_t);
                        if (ndest < 0) {
                                vap->iv_stats.is_rx_mgtdiscard++;
                                break;
                        }
                        prep = IEEE80211_MALLOC(sizeof(*prep),
                            M_80211_MESH_PREP,
                            IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
                        KASSERT(prep != NULL, ("prep == NULL"));

                        prep->prep_ie = *iefrm_t++;
                        prep->prep_len = *iefrm_t++;
                        prep->prep_flags = *iefrm_t++;
                        prep->prep_hopcount = *iefrm_t++;
                        prep->prep_ttl = *iefrm_t++;
                        IEEE80211_ADDR_COPY(prep->prep_targetaddr, iefrm_t);
                        iefrm_t += 6;
                        prep->prep_targetseq = le32dec(iefrm_t); iefrm_t += 4;
                        /* NB: May have Target Proxied Address */
                        if (prep->prep_flags & IEEE80211_MESHPREP_FLAGS_AE)  {
                                IEEE80211_ADDR_COPY(
                                    prep->prep_target_ext_addr, iefrm_t);
                                iefrm_t += 6;
                        }
                        prep->prep_lifetime = le32dec(iefrm_t); iefrm_t += 4;
                        prep->prep_metric = le32dec(iefrm_t); iefrm_t += 4;
                        IEEE80211_ADDR_COPY(prep->prep_origaddr, iefrm_t);
                        iefrm_t += 6;
                        prep->prep_origseq = le32dec(iefrm_t); iefrm_t += 4;

                        hwmp_recv_prep(vap, ni, wh, prep);
                        IEEE80211_FREE(prep, M_80211_MESH_PREP);
                        found++;
                        break;
                }
                case IEEE80211_ELEMID_MESHPERR:
                {
                        int i = 0;

                        iefrm_t = iefrm;
                        ndest = verify_mesh_perr_len(vap, wh, iefrm_t);
                        if (ndest < 0) {
                                vap->iv_stats.is_rx_mgtdiscard++;
                                break;
                        }
                        perr = IEEE80211_MALLOC(sizeof(*perr) +
                            (ndest - 1) * sizeof(*perr->perr_dests),
                            M_80211_MESH_PERR,
                            IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
                        KASSERT(perr != NULL, ("perr == NULL"));

                        perr->perr_ie = *iefrm_t++;
                        perr->perr_len = *iefrm_t++;
                        perr->perr_ttl = *iefrm_t++;
                        perr->perr_ndests = *iefrm_t++;

                        for (i = 0; i<perr->perr_ndests; i++) {
                                perr->perr_dests[i].dest_flags = *iefrm_t++;
                                IEEE80211_ADDR_COPY(
                                    perr->perr_dests[i].dest_addr, iefrm_t);
                                iefrm_t += 6;
                                perr->perr_dests[i].dest_seq = le32dec(iefrm_t);
                                iefrm_t += 4;
                                /* NB: May have Target Proxied Address */
                                if (perr->perr_dests[i].dest_flags &
                                    IEEE80211_MESHPERR_FLAGS_AE) {
                                        IEEE80211_ADDR_COPY(
                                            perr->perr_dests[i].dest_ext_addr,
                                            iefrm_t);
                                        iefrm_t += 6;
                                }
                                perr->perr_dests[i].dest_rcode =
                                    le16dec(iefrm_t);
                                iefrm_t += 2;
                        }

                        hwmp_recv_perr(vap, ni, wh, perr);
                        IEEE80211_FREE(perr, M_80211_MESH_PERR);
                        found++;
                        break;
                }
                case IEEE80211_ELEMID_MESHRANN:
                {
                        const struct ieee80211_meshrann_ie *mrann =
                            (const struct ieee80211_meshrann_ie *) iefrm;
                        if (mrann->rann_len !=
                            sizeof(struct ieee80211_meshrann_ie) - 2) {
                                IEEE80211_DISCARD(vap,
                                    IEEE80211_MSG_ACTION | IEEE80211_MSG_HWMP,
                                    wh, NULL, "%s", "RAN with wrong len");
                                    vap->iv_stats.is_rx_mgtdiscard++;
                                return 1;
                        }
                        memcpy(&rann, mrann, sizeof(rann));
                        rann.rann_seq = le32dec(&mrann->rann_seq);
                        rann.rann_interval = le32dec(&mrann->rann_interval);
                        rann.rann_metric = le32dec(&mrann->rann_metric);
                        hwmp_recv_rann(vap, ni, wh, &rann);
                        found++;
                        break;
                }
                }
                iefrm += iefrm[1] + 2;
        }
        if (!found) {
                IEEE80211_DISCARD(vap,
                    IEEE80211_MSG_ACTION | IEEE80211_MSG_HWMP,
                    wh, NULL, "%s", "PATH SEL action without IE");
                vap->iv_stats.is_rx_mgtdiscard++;
        }
        return 0;
}

static int
hwmp_send_action(struct ieee80211vap *vap,
    const uint8_t da[IEEE80211_ADDR_LEN],
    uint8_t *ie, size_t len)
{
        struct ieee80211_node *ni;
        struct ieee80211com *ic;
        struct ieee80211_bpf_params params;
        struct mbuf *m;
        uint8_t *frm;
        int ret;

        if (IEEE80211_IS_MULTICAST(da)) {
                ni = ieee80211_ref_node(vap->iv_bss);
#ifdef IEEE80211_DEBUG_REFCNT
                IEEE80211_DPRINTF(vap, IEEE80211_MSG_NODE,
                "ieee80211_ref_node (%s:%u) %p<%s> refcnt %d\n",
                __func__, __LINE__,
                ni, ether_sprintf(ni->ni_macaddr),
                ieee80211_node_refcnt(ni)+1);
#endif
                ieee80211_ref_node(ni);
        }
        else
                ni = ieee80211_mesh_find_txnode(vap, da);

        if (vap->iv_state == IEEE80211_S_CAC) {
                IEEE80211_NOTE(vap, IEEE80211_MSG_OUTPUT, ni,
                    "block %s frame in CAC state", "HWMP action");
                vap->iv_stats.is_tx_badstate++;
                return EIO;     /* XXX */
        }

        KASSERT(ni != NULL, ("null node"));
        ic = ni->ni_ic;

        m = ieee80211_getmgtframe(&frm,
            ic->ic_headroom + sizeof(struct ieee80211_frame),
            sizeof(struct ieee80211_action) + len
        );
        if (m == NULL) {
                ieee80211_free_node(ni);
                vap->iv_stats.is_tx_nobuf++;
                return ENOMEM;
        }
        *frm++ = IEEE80211_ACTION_CAT_MESH;
        *frm++ = IEEE80211_ACTION_MESH_HWMP;
        switch (*ie) {
        case IEEE80211_ELEMID_MESHPREQ:
                frm = hwmp_add_meshpreq(frm,
                    (struct ieee80211_meshpreq_ie *)ie);
                break;
        case IEEE80211_ELEMID_MESHPREP:
                frm = hwmp_add_meshprep(frm,
                    (struct ieee80211_meshprep_ie *)ie);
                break;
        case IEEE80211_ELEMID_MESHPERR:
                frm = hwmp_add_meshperr(frm,
                    (struct ieee80211_meshperr_ie *)ie);
                break;
        case IEEE80211_ELEMID_MESHRANN:
                frm = hwmp_add_meshrann(frm,
                    (struct ieee80211_meshrann_ie *)ie);
                break;
        }

        m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
        M_PREPEND(m, sizeof(struct ieee80211_frame), IEEE80211_M_NOWAIT);
        if (m == NULL) {
                ieee80211_free_node(ni);
                vap->iv_stats.is_tx_nobuf++;
                return ENOMEM;
        }

        IEEE80211_TX_LOCK(ic);

        ieee80211_send_setup(ni, m,
            IEEE80211_FC0_TYPE_MGT | IEEE80211_FC0_SUBTYPE_ACTION,
            IEEE80211_NONQOS_TID, vap->iv_myaddr, da, vap->iv_myaddr);

        m->m_flags |= M_ENCAP;          /* mark encapsulated */
        IEEE80211_NODE_STAT(ni, tx_mgmt);

        memset(&params, 0, sizeof(params));
        params.ibp_pri = WME_AC_VO;
        params.ibp_rate0 = ni->ni_txparms->mgmtrate;
        if (IEEE80211_IS_MULTICAST(da))
                params.ibp_try0 = 1;
        else
                params.ibp_try0 = ni->ni_txparms->maxretry;
        params.ibp_power = ni->ni_txpower;
        ret = ieee80211_raw_output(vap, ni, m, &params);
        IEEE80211_TX_UNLOCK(ic);
        return (ret);
}

#define ADDSHORT(frm, v) do {           \
        le16enc(frm, v);                \
        frm += 2;                       \
} while (0)
#define ADDWORD(frm, v) do {            \
        le32enc(frm, v);                \
        frm += 4;                       \
} while (0)
/*
 * Add a Mesh Path Request IE to a frame.
 */
#define PREQ_TFLAGS(n)  preq->preq_targets[n].target_flags
#define PREQ_TADDR(n)   preq->preq_targets[n].target_addr
#define PREQ_TSEQ(n)    preq->preq_targets[n].target_seq
static uint8_t *
hwmp_add_meshpreq(uint8_t *frm, const struct ieee80211_meshpreq_ie *preq)
{
        int i;

        *frm++ = IEEE80211_ELEMID_MESHPREQ;
        *frm++ = preq->preq_len;        /* len already calculated */
        *frm++ = preq->preq_flags;
        *frm++ = preq->preq_hopcount;
        *frm++ = preq->preq_ttl;
        ADDWORD(frm, preq->preq_id);
        IEEE80211_ADDR_COPY(frm, preq->preq_origaddr); frm += 6;
        ADDWORD(frm, preq->preq_origseq);
        if (preq->preq_flags & IEEE80211_MESHPREQ_FLAGS_AE) {
                IEEE80211_ADDR_COPY(frm, preq->preq_orig_ext_addr);
                frm += 6;
        }
        ADDWORD(frm, preq->preq_lifetime);
        ADDWORD(frm, preq->preq_metric);
        *frm++ = preq->preq_tcount;
        for (i = 0; i < preq->preq_tcount; i++) {
                *frm++ = PREQ_TFLAGS(i);
                IEEE80211_ADDR_COPY(frm, PREQ_TADDR(i));
                frm += 6;
                ADDWORD(frm, PREQ_TSEQ(i));
        }
        return frm;
}
#undef  PREQ_TFLAGS
#undef  PREQ_TADDR
#undef  PREQ_TSEQ

/*
 * Add a Mesh Path Reply IE to a frame.
 */
static uint8_t *
hwmp_add_meshprep(uint8_t *frm, const struct ieee80211_meshprep_ie *prep)
{
        *frm++ = IEEE80211_ELEMID_MESHPREP;
        *frm++ = prep->prep_len;        /* len already calculated */
        *frm++ = prep->prep_flags;
        *frm++ = prep->prep_hopcount;
        *frm++ = prep->prep_ttl;
        IEEE80211_ADDR_COPY(frm, prep->prep_targetaddr); frm += 6;
        ADDWORD(frm, prep->prep_targetseq);
        if (prep->prep_flags & IEEE80211_MESHPREP_FLAGS_AE) {
                IEEE80211_ADDR_COPY(frm, prep->prep_target_ext_addr);
                frm += 6;
        }
        ADDWORD(frm, prep->prep_lifetime);
        ADDWORD(frm, prep->prep_metric);
        IEEE80211_ADDR_COPY(frm, prep->prep_origaddr); frm += 6;
        ADDWORD(frm, prep->prep_origseq);
        return frm;
}

/*
 * Add a Mesh Path Error IE to a frame.
 */
#define PERR_DFLAGS(n)  perr->perr_dests[n].dest_flags
#define PERR_DADDR(n)   perr->perr_dests[n].dest_addr
#define PERR_DSEQ(n)    perr->perr_dests[n].dest_seq
#define PERR_EXTADDR(n) perr->perr_dests[n].dest_ext_addr
#define PERR_DRCODE(n)  perr->perr_dests[n].dest_rcode
static uint8_t *
hwmp_add_meshperr(uint8_t *frm, const struct ieee80211_meshperr_ie *perr)
{
        int i;

        *frm++ = IEEE80211_ELEMID_MESHPERR;
        *frm++ = perr->perr_len;        /* len already calculated */
        *frm++ = perr->perr_ttl;
        *frm++ = perr->perr_ndests;
        for (i = 0; i < perr->perr_ndests; i++) {
                *frm++ = PERR_DFLAGS(i);
                IEEE80211_ADDR_COPY(frm, PERR_DADDR(i));
                frm += 6;
                ADDWORD(frm, PERR_DSEQ(i));
                if (PERR_DFLAGS(i) & IEEE80211_MESHPERR_FLAGS_AE) {
                        IEEE80211_ADDR_COPY(frm, PERR_EXTADDR(i));
                        frm += 6;
                }
                ADDSHORT(frm, PERR_DRCODE(i));
        }
        return frm;
}
#undef  PERR_DFLAGS
#undef  PERR_DADDR
#undef  PERR_DSEQ
#undef  PERR_EXTADDR
#undef  PERR_DRCODE

/*
 * Add a Root Annoucement IE to a frame.
 */
static uint8_t *
hwmp_add_meshrann(uint8_t *frm, const struct ieee80211_meshrann_ie *rann)
{
        *frm++ = IEEE80211_ELEMID_MESHRANN;
        *frm++ = rann->rann_len;
        *frm++ = rann->rann_flags;
        *frm++ = rann->rann_hopcount;
        *frm++ = rann->rann_ttl;
        IEEE80211_ADDR_COPY(frm, rann->rann_addr); frm += 6;
        ADDWORD(frm, rann->rann_seq);
        ADDWORD(frm, rann->rann_interval);
        ADDWORD(frm, rann->rann_metric);
        return frm;
}

static void
hwmp_rootmode_setup(struct ieee80211vap *vap)
{
        struct ieee80211_hwmp_state *hs = vap->iv_hwmp;
        struct ieee80211_mesh_state *ms = vap->iv_mesh;

        switch (hs->hs_rootmode) {
        case IEEE80211_HWMP_ROOTMODE_DISABLED:
                callout_drain(&hs->hs_roottimer);
                ms->ms_flags &= ~IEEE80211_MESHFLAGS_ROOT;
                break;
        case IEEE80211_HWMP_ROOTMODE_NORMAL:
        case IEEE80211_HWMP_ROOTMODE_PROACTIVE:
                callout_reset(&hs->hs_roottimer, ieee80211_hwmp_rootint,
                    hwmp_rootmode_cb, vap);
                ms->ms_flags |= IEEE80211_MESHFLAGS_ROOT;
                break;
        case IEEE80211_HWMP_ROOTMODE_RANN:
                callout_reset(&hs->hs_roottimer, ieee80211_hwmp_rannint,
                    hwmp_rootmode_rann_cb, vap);
                ms->ms_flags |= IEEE80211_MESHFLAGS_ROOT;
                break;
        }
}

/*
 * Send a broadcast Path Request to find all nodes on the mesh. We are
 * called when the vap is configured as a HWMP root node.
 */
#define PREQ_TFLAGS(n)  preq.preq_targets[n].target_flags
#define PREQ_TADDR(n)   preq.preq_targets[n].target_addr
#define PREQ_TSEQ(n)    preq.preq_targets[n].target_seq
static void
hwmp_rootmode_cb(void *arg)
{
        struct ieee80211vap *vap = (struct ieee80211vap *)arg;
        struct ieee80211_hwmp_state *hs = vap->iv_hwmp;
        struct ieee80211_mesh_state *ms = vap->iv_mesh;
        struct ieee80211_meshpreq_ie preq;

        IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, vap->iv_bss,
            "%s", "send broadcast PREQ");

        preq.preq_flags = 0;
        if (ms->ms_flags & IEEE80211_MESHFLAGS_GATE)
                preq.preq_flags |= IEEE80211_MESHPREQ_FLAGS_GATE;
        if (hs->hs_rootmode == IEEE80211_HWMP_ROOTMODE_PROACTIVE)
                preq.preq_flags |= IEEE80211_MESHPREQ_FLAGS_PP;
        preq.preq_hopcount = 0;
        preq.preq_ttl = ms->ms_ttl;
        preq.preq_id = ++hs->hs_preqid;
        IEEE80211_ADDR_COPY(preq.preq_origaddr, vap->iv_myaddr);
        preq.preq_origseq = ++hs->hs_seq;
        preq.preq_lifetime = ticks_to_msecs(ieee80211_hwmp_roottimeout);
        preq.preq_metric = IEEE80211_MESHLMETRIC_INITIALVAL;
        preq.preq_tcount = 1;
        IEEE80211_ADDR_COPY(PREQ_TADDR(0), broadcastaddr);
        PREQ_TFLAGS(0) = IEEE80211_MESHPREQ_TFLAGS_TO |
            IEEE80211_MESHPREQ_TFLAGS_USN;
        PREQ_TSEQ(0) = 0;
        vap->iv_stats.is_hwmp_rootreqs++;
        /* NB: we enforce rate check ourself */
        hwmp_send_preq(vap, broadcastaddr, &preq, NULL, NULL);
        hwmp_rootmode_setup(vap);
}
#undef  PREQ_TFLAGS
#undef  PREQ_TADDR
#undef  PREQ_TSEQ

/*
 * Send a Root Annoucement (RANN) to find all the nodes on the mesh. We are
 * called when the vap is configured as a HWMP RANN root node.
 */
static void
hwmp_rootmode_rann_cb(void *arg)
{
        struct ieee80211vap *vap = (struct ieee80211vap *)arg;
        struct ieee80211_hwmp_state *hs = vap->iv_hwmp;
        struct ieee80211_mesh_state *ms = vap->iv_mesh;
        struct ieee80211_meshrann_ie rann;

        IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, vap->iv_bss,
            "%s", "send broadcast RANN");

        rann.rann_flags = 0;
        if (ms->ms_flags & IEEE80211_MESHFLAGS_GATE)
                rann.rann_flags |= IEEE80211_MESHFLAGS_GATE;
        rann.rann_hopcount = 0;
        rann.rann_ttl = ms->ms_ttl;
        IEEE80211_ADDR_COPY(rann.rann_addr, vap->iv_myaddr);
        rann.rann_seq = ++hs->hs_seq;
        rann.rann_interval = ieee80211_hwmp_rannint;
        rann.rann_metric = IEEE80211_MESHLMETRIC_INITIALVAL;

        vap->iv_stats.is_hwmp_rootrann++;
        hwmp_send_rann(vap, broadcastaddr, &rann);
        hwmp_rootmode_setup(vap);
}

/*
 * Update forwarding information to TA if metric improves.
 */
static void
hwmp_update_transmitter(struct ieee80211vap *vap, struct ieee80211_node *ni,
    const char *hwmp_frame)
{
        struct ieee80211_mesh_state *ms = vap->iv_mesh;
        struct ieee80211_mesh_route *rttran = NULL;     /* Transmitter */
        int metric = 0;

        rttran = ieee80211_mesh_rt_find(vap, ni->ni_macaddr);
        if (rttran == NULL) {
                rttran = ieee80211_mesh_rt_add(vap, ni->ni_macaddr);
                if (rttran == NULL) {
                        IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                            "unable to add path to transmitter %6D of %s",
                            ni->ni_macaddr, ":", hwmp_frame);
                        vap->iv_stats.is_mesh_rtaddfailed++;
                        return;
                }
        }
        metric = ms->ms_pmetric->mpm_metric(ni);
        if (!(rttran->rt_flags & IEEE80211_MESHRT_FLAGS_VALID) ||
            rttran->rt_metric > metric)
        {
                IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                    "%s path to transmitter %6D of %s, metric %d:%d",
                    rttran->rt_flags & IEEE80211_MESHRT_FLAGS_VALID ?
                    "prefer" : "update", ni->ni_macaddr, ":", hwmp_frame,
                    rttran->rt_metric, metric);
                IEEE80211_ADDR_COPY(rttran->rt_nexthop, ni->ni_macaddr);
                rttran->rt_metric = metric;
                rttran->rt_nhops  = 1;
                ieee80211_mesh_rt_update(rttran, ms->ms_ppath->mpp_inact);
                rttran->rt_flags = IEEE80211_MESHRT_FLAGS_VALID;
        }
}

#define PREQ_TFLAGS(n)  preq->preq_targets[n].target_flags
#define PREQ_TADDR(n)   preq->preq_targets[n].target_addr
#define PREQ_TSEQ(n)    preq->preq_targets[n].target_seq
static void
hwmp_recv_preq(struct ieee80211vap *vap, struct ieee80211_node *ni,
    const struct ieee80211_frame *wh, const struct ieee80211_meshpreq_ie *preq)
{
        struct ieee80211_mesh_state *ms = vap->iv_mesh;
        struct ieee80211_mesh_route *rtorig = NULL;
        struct ieee80211_mesh_route *rtorig_ext = NULL;
        struct ieee80211_mesh_route *rttarg = NULL;
        struct ieee80211_hwmp_route *hrorig = NULL;
        struct ieee80211_hwmp_route *hrtarg = NULL;
        struct ieee80211_hwmp_state *hs = vap->iv_hwmp;
        ieee80211_hwmp_seq preqid;      /* last seen preqid for orig */
        uint32_t metric = 0;

        /*
         * Ignore PREQs from us. Could happen because someone forward it
         * back to us.
         */
        if (IEEE80211_ADDR_EQ(vap->iv_myaddr, preq->preq_origaddr))
                return;

        IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
            "received PREQ, orig %6D, targ(0) %6D", preq->preq_origaddr, ":",
            PREQ_TADDR(0), ":");

        /*
         * Acceptance criteria: (if the PREQ is not for us or not broadcast,
         * or an external mac address not proxied by us),
         * AND forwarding is disabled, discard this PREQ.
         */
        rttarg = ieee80211_mesh_rt_find(vap, PREQ_TADDR(0));
        if (!(ms->ms_flags & IEEE80211_MESHFLAGS_FWD) &&
            (!IEEE80211_ADDR_EQ(vap->iv_myaddr, PREQ_TADDR(0)) ||
            !IEEE80211_IS_MULTICAST(PREQ_TADDR(0)) ||
            (rttarg != NULL &&
            rttarg->rt_flags & IEEE80211_MESHRT_FLAGS_PROXY &&
            IEEE80211_ADDR_EQ(vap->iv_myaddr, rttarg->rt_mesh_gate)))) {
                IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_HWMP,
                    preq->preq_origaddr, NULL, "%s", "not accepting PREQ");
                return;
        }
        /*
         * Acceptance criteria: if unicast addressed
         * AND no valid forwarding for Target of PREQ, discard this PREQ.
         */
        if(rttarg != NULL)
                hrtarg = IEEE80211_MESH_ROUTE_PRIV(rttarg,
                    struct ieee80211_hwmp_route);
        /* Address mode: ucast */
        if(preq->preq_flags & IEEE80211_MESHPREQ_FLAGS_AM &&
            rttarg == NULL &&
            !IEEE80211_ADDR_EQ(vap->iv_myaddr, PREQ_TADDR(0))) {
                IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_HWMP,
                    preq->preq_origaddr, NULL,
                    "unicast addressed PREQ of unknown target %6D",
                    PREQ_TADDR(0), ":");
                return;
        }

        /* PREQ ACCEPTED */

        rtorig = ieee80211_mesh_rt_find(vap, preq->preq_origaddr);
        if (rtorig == NULL) {
                rtorig = ieee80211_mesh_rt_add(vap, preq->preq_origaddr);
                if (rtorig == NULL) {
                        IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                            "unable to add orig path to %6D",
                            preq->preq_origaddr, ":");
                        vap->iv_stats.is_mesh_rtaddfailed++;
                        return;
                }
                IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                    "adding originator %6D", preq->preq_origaddr, ":");
        }
        hrorig = IEEE80211_MESH_ROUTE_PRIV(rtorig, struct ieee80211_hwmp_route);

        /* record last seen preqid */
        preqid = hrorig->hr_preqid;
        hrorig->hr_preqid = HWMP_SEQ_MAX(hrorig->hr_preqid, preq->preq_id);

        /* Data creation and update of forwarding information
         * according to Table 11C-8 for originator mesh STA.
         */
        metric = preq->preq_metric + ms->ms_pmetric->mpm_metric(ni);
        if (HWMP_SEQ_GT(preq->preq_origseq, hrorig->hr_seq) ||
            (HWMP_SEQ_EQ(preq->preq_origseq, hrorig->hr_seq) &&
            metric < rtorig->rt_metric)) {
                hrorig->hr_seq = preq->preq_origseq;
                IEEE80211_ADDR_COPY(rtorig->rt_nexthop, wh->i_addr2);
                rtorig->rt_metric = metric;
                rtorig->rt_nhops  = preq->preq_hopcount + 1;
                ieee80211_mesh_rt_update(rtorig, preq->preq_lifetime);
                /* Path to orig is valid now.
                 * NB: we know it can't be Proxy, and if it is GATE
                 * it will be marked below.
                 */
                rtorig->rt_flags = IEEE80211_MESHRT_FLAGS_VALID;
        } else if ((hrtarg != NULL &&
            !HWMP_SEQ_EQ(hrtarg->hr_seq, PREQ_TSEQ(0))) ||
            (rtorig->rt_flags & IEEE80211_MESHRT_FLAGS_VALID &&
            preqid >= preq->preq_id)) {
                IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                    "discard PREQ from %6D, old seqno %u <= %u,"
                    " or old preqid %u < %u",
                    preq->preq_origaddr, ":",
                    preq->preq_origseq, hrorig->hr_seq,
                    preq->preq_id, preqid);
                return;
        }

        /* Update forwarding information to TA if metric improves. */
        hwmp_update_transmitter(vap, ni, "PREQ");

        /*
         * Check if the PREQ is addressed to us.
         * or a Proxy currently gated by us.
         */
        if (IEEE80211_ADDR_EQ(vap->iv_myaddr, PREQ_TADDR(0)) ||
            (ms->ms_flags & IEEE80211_MESHFLAGS_GATE &&
            rttarg != NULL &&
            IEEE80211_ADDR_EQ(vap->iv_myaddr, rttarg->rt_mesh_gate) &&
            rttarg->rt_flags & IEEE80211_MESHRT_FLAGS_PROXY &&
            rttarg->rt_flags & IEEE80211_MESHRT_FLAGS_VALID)) {
                struct ieee80211_meshprep_ie prep;

                /*
                 * When we are the target we shall update our own HWMP seq
                 * number with max of (current and preq->seq) + 1
                 */
                hs->hs_seq = HWMP_SEQ_MAX(hs->hs_seq, PREQ_TSEQ(0)) + 1;

                prep.prep_flags = 0;
                prep.prep_hopcount = 0;
                prep.prep_metric = IEEE80211_MESHLMETRIC_INITIALVAL;
                IEEE80211_ADDR_COPY(prep.prep_targetaddr, vap->iv_myaddr);
                if (rttarg != NULL && /* if NULL it means we are the target */
                    rttarg->rt_flags & IEEE80211_MESHRT_FLAGS_PROXY) {
                        IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                            "reply for proxy %6D", rttarg->rt_dest, ":");
                        prep.prep_flags |= IEEE80211_MESHPREP_FLAGS_AE;
                        IEEE80211_ADDR_COPY(prep.prep_target_ext_addr,
                            rttarg->rt_dest);
                        /* update proxy seqno to HWMP seqno */
                        rttarg->rt_ext_seq = hs->hs_seq;
                        prep.prep_hopcount = rttarg->rt_nhops;
                        prep.prep_metric = rttarg->rt_metric;
                        IEEE80211_ADDR_COPY(prep.prep_targetaddr, rttarg->rt_mesh_gate);
                }
                /*
                 * Build and send a PREP frame.
                 */
                prep.prep_ttl = ms->ms_ttl;
                prep.prep_targetseq = hs->hs_seq;
                prep.prep_lifetime = preq->preq_lifetime;
                IEEE80211_ADDR_COPY(prep.prep_origaddr, preq->preq_origaddr);
                prep.prep_origseq = preq->preq_origseq;

                IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                    "reply to %6D", preq->preq_origaddr, ":");
                hwmp_send_prep(vap, wh->i_addr2, &prep);
                return;
        }
        /* we may update our proxy information for the orig external */
        else if (preq->preq_flags & IEEE80211_MESHPREQ_FLAGS_AE) {
                rtorig_ext =
                    ieee80211_mesh_rt_find(vap, preq->preq_orig_ext_addr);
                if (rtorig_ext == NULL) {
                        rtorig_ext = ieee80211_mesh_rt_add(vap,
                            preq->preq_orig_ext_addr);
                        if (rtorig_ext == NULL) {
                                IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                                    "unable to add orig ext proxy to %6D",
                                    preq->preq_orig_ext_addr, ":");
                                vap->iv_stats.is_mesh_rtaddfailed++;
                                return;
                        }
                        IEEE80211_ADDR_COPY(rtorig_ext->rt_mesh_gate,
                            preq->preq_origaddr);
                }
                rtorig_ext->rt_ext_seq = preq->preq_origseq;
                ieee80211_mesh_rt_update(rtorig_ext, preq->preq_lifetime);
        }
        /*
         * Proactive PREQ: reply with a proactive PREP to the
         * root STA if requested.
         */
        if (IEEE80211_ADDR_EQ(PREQ_TADDR(0), broadcastaddr) &&
            (PREQ_TFLAGS(0) & IEEE80211_MESHPREQ_TFLAGS_TO)) {
                IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                    "root mesh station @ %6D", preq->preq_origaddr, ":");

                /* Check if root is a mesh gate, mark it */
                if (preq->preq_flags & IEEE80211_MESHPREQ_FLAGS_GATE) {
                        struct ieee80211_mesh_gate_route *gr;

                        rtorig->rt_flags |= IEEE80211_MESHRT_FLAGS_GATE;
                        gr = ieee80211_mesh_mark_gate(vap, preq->preq_origaddr,
                            rtorig);
                        gr->gr_lastseq = 0; /* NOT GANN */
                }

                /*
                 * Reply with a PREP if we don't have a path to the root
                 * or if the root sent us a proactive PREQ.
                 */
                if ((rtorig->rt_flags & IEEE80211_MESHRT_FLAGS_VALID) == 0 ||
                    (preq->preq_flags & IEEE80211_MESHPREQ_FLAGS_PP)) {
                        struct ieee80211_meshprep_ie prep;

                        prep.prep_flags = 0;
                        prep.prep_hopcount = 0;
                        prep.prep_ttl = ms->ms_ttl;
                        IEEE80211_ADDR_COPY(prep.prep_origaddr,
                            preq->preq_origaddr);
                        prep.prep_origseq = preq->preq_origseq;
                        prep.prep_lifetime = preq->preq_lifetime;
                        prep.prep_metric = IEEE80211_MESHLMETRIC_INITIALVAL;
                        IEEE80211_ADDR_COPY(prep.prep_targetaddr,
                            vap->iv_myaddr);
                        prep.prep_targetseq = ++hs->hs_seq;
                        hwmp_send_prep(vap, rtorig->rt_nexthop, &prep);
                }
        }

        /*
         * Forwarding and Intermediate reply for PREQs with 1 target.
         */
        if ((preq->preq_tcount == 1) && (preq->preq_ttl > 1) &&
            (ms->ms_flags & IEEE80211_MESHFLAGS_FWD)) {
                struct ieee80211_meshpreq_ie ppreq; /* propagated PREQ */

                memcpy(&ppreq, preq, sizeof(ppreq));

                /*
                 * We have a valid route to this node.
                 * NB: if target is proxy dont reply.
                 */
                if (rttarg != NULL &&
                    rttarg->rt_flags & IEEE80211_MESHRT_FLAGS_VALID &&
                    !(rttarg->rt_flags & IEEE80211_MESHRT_FLAGS_PROXY)) {
                        /*
                         * Check if we can send an intermediate Path Reply,
                         * i.e., Target Only bit is not set and target is not
                         * the MAC broadcast address.
                         */
                        if (!(PREQ_TFLAGS(0) & IEEE80211_MESHPREQ_TFLAGS_TO) &&
                            !IEEE80211_ADDR_EQ(PREQ_TADDR(0), broadcastaddr)) {
                                struct ieee80211_meshprep_ie prep;

                                IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                                    "intermediate reply for PREQ from %6D",
                                    preq->preq_origaddr, ":");
                                prep.prep_flags = 0;
                                prep.prep_hopcount = rttarg->rt_nhops;
                                prep.prep_ttl = ms->ms_ttl;
                                IEEE80211_ADDR_COPY(&prep.prep_targetaddr,
                                    PREQ_TADDR(0));
                                prep.prep_targetseq = hrtarg->hr_seq;
                                prep.prep_lifetime = preq->preq_lifetime;
                                prep.prep_metric =rttarg->rt_metric;
                                IEEE80211_ADDR_COPY(&prep.prep_origaddr,
                                    preq->preq_origaddr);
                                prep.prep_origseq = hrorig->hr_seq;
                                hwmp_send_prep(vap, rtorig->rt_nexthop, &prep);

                                /*
                                 * Set TO and unset RF bits because we have
                                 * sent a PREP.
                                 */
                                ppreq.preq_targets[0].target_flags |=
                                    IEEE80211_MESHPREQ_TFLAGS_TO;
                        }
                }

                IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                    "forward PREQ from %6D",
                    preq->preq_origaddr, ":");
                ppreq.preq_hopcount += 1;
                ppreq.preq_ttl -= 1;
                ppreq.preq_metric += ms->ms_pmetric->mpm_metric(ni);

                /* don't do PREQ ratecheck when we propagate */
                hwmp_send_preq(vap, broadcastaddr, &ppreq, NULL, NULL);
        }
}
#undef  PREQ_TFLAGS
#undef  PREQ_TADDR
#undef  PREQ_TSEQ

static int
hwmp_send_preq(struct ieee80211vap *vap,
    const uint8_t da[IEEE80211_ADDR_LEN],
    struct ieee80211_meshpreq_ie *preq,
    struct timeval *last, struct timeval *minint)
{

        /*
         * Enforce PREQ interval.
         * NB: Proactive ROOT PREQs rate is handled by cb task.
         */
        if (last != NULL && minint != NULL) {
                if (ratecheck(last, minint) == 0)
                        return EALREADY; /* XXX: we should postpone */
                getmicrouptime(last);
        }

        /*
         * mesh preq action frame format
         *     [6] da
         *     [6] sa
         *     [6] addr3 = sa
         *     [1] action
         *     [1] category
         *     [tlv] mesh path request
         */
        preq->preq_ie = IEEE80211_ELEMID_MESHPREQ;
        preq->preq_len = (preq->preq_flags & IEEE80211_MESHPREQ_FLAGS_AE ?
            IEEE80211_MESHPREQ_BASE_SZ_AE : IEEE80211_MESHPREQ_BASE_SZ) +
            preq->preq_tcount * IEEE80211_MESHPREQ_TRGT_SZ;
        return hwmp_send_action(vap, da, (uint8_t *)preq, preq->preq_len+2);
}

static void
hwmp_recv_prep(struct ieee80211vap *vap, struct ieee80211_node *ni,
    const struct ieee80211_frame *wh, const struct ieee80211_meshprep_ie *prep)
{
#define IS_PROXY(rt)    (rt->rt_flags & IEEE80211_MESHRT_FLAGS_PROXY)
#define PROXIED_BY_US(rt)               \
    (IEEE80211_ADDR_EQ(vap->iv_myaddr, rt->rt_mesh_gate))
        struct ieee80211_mesh_state *ms = vap->iv_mesh;
        struct ieee80211_hwmp_state *hs = vap->iv_hwmp;
        struct ieee80211_mesh_route *rt = NULL;
        struct ieee80211_mesh_route *rtorig = NULL;
        struct ieee80211_mesh_route *rtext = NULL;
        struct ieee80211_hwmp_route *hr;
        struct ieee80211com *ic = vap->iv_ic;
        struct mbuf *m, *next;
        uint32_t metric = 0;
        const uint8_t *addr;

        IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
            "received PREP, orig %6D, targ %6D", prep->prep_origaddr, ":",
            prep->prep_targetaddr, ":");

        /*
         * Acceptance criteria: (If the corresponding PREP was not generated
         * by us OR not generated by an external mac that is not proxied by us)
         * AND forwarding is disabled, discard this PREP.
         */
        rtorig = ieee80211_mesh_rt_find(vap, prep->prep_origaddr);
        if ((!IEEE80211_ADDR_EQ(vap->iv_myaddr, prep->prep_origaddr) ||
            (rtorig != NULL && IS_PROXY(rtorig) && !PROXIED_BY_US(rtorig))) &&
            !(ms->ms_flags & IEEE80211_MESHFLAGS_FWD)){
                IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                    "discard PREP, orig(%6D) not proxied or generated by us",
                    prep->prep_origaddr, ":");
                return;
        }

        /* PREP ACCEPTED */

        /*
         * If accepted shall create or update the active forwarding information
         * it maintains for the target mesh STA of the PREP (according to the
         * rules defined in 13.10.8.4). If the conditions for creating or
         * updating the forwarding information have not been met in those
         * rules, no further steps are applied to the PREP.
         */
        rt = ieee80211_mesh_rt_find(vap, prep->prep_targetaddr);
        if (rt == NULL) {
                rt = ieee80211_mesh_rt_add(vap, prep->prep_targetaddr);
                if (rt == NULL) {
                        IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                            "unable to add PREP path to %6D",
                            prep->prep_targetaddr, ":");
                        vap->iv_stats.is_mesh_rtaddfailed++;
                        return;
                }
                IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                    "adding target %6D", prep->prep_targetaddr, ":");
        }
        hr = IEEE80211_MESH_ROUTE_PRIV(rt, struct ieee80211_hwmp_route);
        /* update path metric */
        metric = prep->prep_metric + ms->ms_pmetric->mpm_metric(ni);
        if ((rt->rt_flags & IEEE80211_MESHRT_FLAGS_VALID)) {
                if (HWMP_SEQ_LT(prep->prep_targetseq, hr->hr_seq)) {
                        IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                            "discard PREP from %6D, old seq no %u < %u",
                            prep->prep_targetaddr, ":",
                            prep->prep_targetseq, hr->hr_seq);
                        return;
                } else if (HWMP_SEQ_LEQ(prep->prep_targetseq, hr->hr_seq) &&
                    metric > rt->rt_metric) {
                        IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                            "discard PREP from %6D, new metric %u > %u",
                            prep->prep_targetaddr, ":",
                            metric, rt->rt_metric);
                        return;
                }
        }

        IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
            "%s path to %6D, hopcount %d:%d metric %d:%d",
            rt->rt_flags & IEEE80211_MESHRT_FLAGS_VALID ?
            "prefer" : "update",
            prep->prep_targetaddr, ":",
            rt->rt_nhops, prep->prep_hopcount + 1,
            rt->rt_metric, metric);

        hr->hr_seq = prep->prep_targetseq;
        hr->hr_preqretries = 0;
        IEEE80211_ADDR_COPY(rt->rt_nexthop, ni->ni_macaddr);
        rt->rt_metric = metric;
        rt->rt_nhops = prep->prep_hopcount + 1;
        ieee80211_mesh_rt_update(rt, prep->prep_lifetime);
        if (rt->rt_flags & IEEE80211_MESHRT_FLAGS_DISCOVER) {
                /* discovery complete */
                rt->rt_flags &= ~IEEE80211_MESHRT_FLAGS_DISCOVER;
        }
        rt->rt_flags |= IEEE80211_MESHRT_FLAGS_VALID; /* mark valid */

        /* Update forwarding information to TA if metric improves */
        hwmp_update_transmitter(vap, ni, "PREP");

        /*
         * If it's NOT for us, propagate the PREP
         */
        if (!IEEE80211_ADDR_EQ(vap->iv_myaddr, prep->prep_origaddr) &&
            prep->prep_ttl > 1 &&
            prep->prep_hopcount < hs->hs_maxhops) {
                struct ieee80211_meshprep_ie pprep; /* propagated PREP */
                /*
                 * NB: We should already have setup the path to orig
                 * mesh STA when we propagated PREQ to target mesh STA,
                 * no PREP is generated without a corresponding PREQ.
                 * XXX: for now just ignore.
                 */
                if (rtorig == NULL) {
                        IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                            "received PREP for an unknown orig(%6D)",
                            prep->prep_origaddr, ":");
                        return;
                }

                IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                    "propagate PREP from %6D",
                    prep->prep_targetaddr, ":");

                memcpy(&pprep, prep, sizeof(pprep));
                pprep.prep_hopcount += 1;
                pprep.prep_ttl -= 1;
                pprep.prep_metric += ms->ms_pmetric->mpm_metric(ni);
                hwmp_send_prep(vap, rtorig->rt_nexthop, &pprep);

                /* precursor list for the Target Mesh STA Address is updated */
        }

        /*
         * Check if we received a PREP w/ AE and store target external address.
         * We may store target external address if received PREP w/ AE
         * and we are not final destination
         */
        if (prep->prep_flags & IEEE80211_MESHPREP_FLAGS_AE) {
                rtext = ieee80211_mesh_rt_find(vap,
                        prep->prep_target_ext_addr);
                if (rtext == NULL) {
                        rtext = ieee80211_mesh_rt_add(vap,
                                prep->prep_target_ext_addr);
                        if (rtext == NULL) {
                                IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                                    "unable to add PREP path to proxy %6D",
                                    prep->prep_targetaddr, ":");
                                vap->iv_stats.is_mesh_rtaddfailed++;
                                return;
                        }
                }
                IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                    "%s path to %6D, hopcount %d:%d metric %d:%d",
                    rtext->rt_flags & IEEE80211_MESHRT_FLAGS_VALID ?
                    "prefer" : "update",
                    prep->prep_target_ext_addr, ":",
                    rtext->rt_nhops, prep->prep_hopcount + 1,
                    rtext->rt_metric, metric);

                rtext->rt_flags = IEEE80211_MESHRT_FLAGS_PROXY |
                        IEEE80211_MESHRT_FLAGS_VALID;
                IEEE80211_ADDR_COPY(rtext->rt_dest,
                    prep->prep_target_ext_addr);
                IEEE80211_ADDR_COPY(rtext->rt_mesh_gate,
                    prep->prep_targetaddr);
                IEEE80211_ADDR_COPY(rtext->rt_nexthop, wh->i_addr2);
                rtext->rt_metric = metric;
                rtext->rt_lifetime = prep->prep_lifetime;
                rtext->rt_nhops = prep->prep_hopcount + 1;
                rtext->rt_ext_seq = prep->prep_origseq; /* new proxy seq */
                /*
                 * XXX: proxy entries have no HWMP priv data,
                 * nullify them to be sure?
                 */
        }
        /*
         * Check for frames queued awaiting path discovery.
         * XXX probably can tell exactly and avoid remove call
         * NB: hash may have false matches, if so they will get
         *     stuck back on the stageq because there won't be
         *     a path.
         */
        addr = prep->prep_flags & IEEE80211_MESHPREP_FLAGS_AE ?
            prep->prep_target_ext_addr : prep->prep_targetaddr;
        m = ieee80211_ageq_remove(&ic->ic_stageq,
            (struct ieee80211_node *)(uintptr_t)
            ieee80211_mac_hash(ic, addr)); /* either dest or ext_dest */

        /*
         * All frames in the stageq here should be non-M_ENCAP; or things
         * will get very unhappy.
         */
        for (; m != NULL; m = next) {
                next = m->m_nextpkt;
                m->m_nextpkt = NULL;
                IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                    "flush queued frame %p len %d", m, m->m_pkthdr.len);
                /*
                 * If the mbuf has M_ENCAP set, ensure we free it.
                 * Note that after if_transmit() is called, m is invalid.
                 */
                (void) ieee80211_vap_xmitpkt(vap, m);
        }
#undef  IS_PROXY
#undef  PROXIED_BY_US
}

static int
hwmp_send_prep(struct ieee80211vap *vap,
    const uint8_t da[IEEE80211_ADDR_LEN],
    struct ieee80211_meshprep_ie *prep)
{
        /* NB: there's no PREP minimum interval. */

        /*
         * mesh prep action frame format
         *     [6] da
         *     [6] sa
         *     [6] addr3 = sa
         *     [1] action
         *     [1] category
         *     [tlv] mesh path reply
         */
        prep->prep_ie = IEEE80211_ELEMID_MESHPREP;
        prep->prep_len = prep->prep_flags & IEEE80211_MESHPREP_FLAGS_AE ?
            IEEE80211_MESHPREP_BASE_SZ_AE : IEEE80211_MESHPREP_BASE_SZ;
        return hwmp_send_action(vap, da, (uint8_t *)prep, prep->prep_len + 2);
}

#define PERR_DFLAGS(n)  perr.perr_dests[n].dest_flags
#define PERR_DADDR(n)   perr.perr_dests[n].dest_addr
#define PERR_DSEQ(n)    perr.perr_dests[n].dest_seq
#define PERR_DRCODE(n)  perr.perr_dests[n].dest_rcode
static void
hwmp_peerdown(struct ieee80211_node *ni)
{
        struct ieee80211vap *vap = ni->ni_vap;
        struct ieee80211_mesh_state *ms = vap->iv_mesh;
        struct ieee80211_meshperr_ie perr;
        struct ieee80211_mesh_route *rt;
        struct ieee80211_hwmp_route *hr;

        rt = ieee80211_mesh_rt_find(vap, ni->ni_macaddr);
        if (rt == NULL)
                return;
        hr = IEEE80211_MESH_ROUTE_PRIV(rt, struct ieee80211_hwmp_route);
        IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
            "%s", "delete route entry");
        perr.perr_ttl = ms->ms_ttl;
        perr.perr_ndests = 1;
        PERR_DFLAGS(0) = 0;
        if (hr->hr_seq == 0)
                PERR_DFLAGS(0) |= IEEE80211_MESHPERR_DFLAGS_USN;
        PERR_DFLAGS(0) |= IEEE80211_MESHPERR_DFLAGS_RC;
        IEEE80211_ADDR_COPY(PERR_DADDR(0), rt->rt_dest);
        PERR_DSEQ(0) = ++hr->hr_seq;
        PERR_DRCODE(0) = IEEE80211_REASON_MESH_PERR_DEST_UNREACH;
        /* NB: flush everything passing through peer */
        ieee80211_mesh_rt_flush_peer(vap, ni->ni_macaddr);
        hwmp_send_perr(vap, broadcastaddr, &perr);
}
#undef  PERR_DFLAGS
#undef  PERR_DADDR
#undef  PERR_DSEQ
#undef  PERR_DRCODE

#define PERR_DFLAGS(n)          perr->perr_dests[n].dest_flags
#define PERR_DADDR(n)           perr->perr_dests[n].dest_addr
#define PERR_DSEQ(n)            perr->perr_dests[n].dest_seq
#define PERR_DEXTADDR(n)        perr->perr_dests[n].dest_ext_addr
static void
hwmp_recv_perr(struct ieee80211vap *vap, struct ieee80211_node *ni,
    const struct ieee80211_frame *wh, const struct ieee80211_meshperr_ie *perr)
{
        struct ieee80211_mesh_state *ms = vap->iv_mesh;
        struct ieee80211_mesh_route *rt = NULL;
        struct ieee80211_mesh_route *rt_ext = NULL;
        struct ieee80211_hwmp_route *hr;
        struct ieee80211_meshperr_ie *pperr = NULL;
        int i, j = 0, forward = 0;

        IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
            "received PERR from %6D", wh->i_addr2, ":");

        /*
         * if forwarding is true, prepare pperr
         */
        if (ms->ms_flags & IEEE80211_MESHFLAGS_FWD) {
                forward = 1;
                pperr = IEEE80211_MALLOC(sizeof(*perr) + 31*sizeof(*perr->perr_dests),
                    M_80211_MESH_PERR, IEEE80211_M_NOWAIT); /* XXX: magic number, 32 err dests */
        }

        /*
         * Acceptance criteria: check if we have forwarding information
         * stored about destination, and that nexthop == TA of this PERR.
         * NB: we also build a new PERR to propagate in case we should forward.
         */
        for (i = 0; i < perr->perr_ndests; i++) {
                rt = ieee80211_mesh_rt_find(vap, PERR_DADDR(i));
                if (rt == NULL)
                        continue;
                if (!IEEE80211_ADDR_EQ(rt->rt_nexthop, wh->i_addr2))
                        continue;

                /* found and accepted a PERR ndest element, process it... */
                if (forward)
                        memcpy(&pperr->perr_dests[j], &perr->perr_dests[i],
                            sizeof(*perr->perr_dests));
                hr = IEEE80211_MESH_ROUTE_PRIV(rt, struct ieee80211_hwmp_route);
                switch(PERR_DFLAGS(i)) {
                case (IEEE80211_REASON_MESH_PERR_NO_FI):
                        if (PERR_DSEQ(i) == 0) {
                                hr->hr_seq++;
                                if (forward) {
                                        pperr->perr_dests[j].dest_seq =
                                            hr->hr_seq;
                                }
                        } else {
                                hr->hr_seq = PERR_DSEQ(i);
                        }
                        rt->rt_flags &= ~IEEE80211_MESHRT_FLAGS_VALID;
                        j++;
                        break;
                case (IEEE80211_REASON_MESH_PERR_DEST_UNREACH):
                        if(HWMP_SEQ_GT(PERR_DSEQ(i), hr->hr_seq)) {
                                hr->hr_seq = PERR_DSEQ(i);
                                rt->rt_flags &= ~IEEE80211_MESHRT_FLAGS_VALID;
                                j++;
                        }
                        break;
                case (IEEE80211_REASON_MESH_PERR_NO_PROXY):
                        rt_ext = ieee80211_mesh_rt_find(vap, PERR_DEXTADDR(i));
                        if (rt_ext != NULL) {
                                rt_ext->rt_flags &=
                                    ~IEEE80211_MESHRT_FLAGS_VALID;
                                j++;
                        }
                        break;
                default:
                        IEEE80211_DISCARD(vap, IEEE80211_MSG_HWMP, wh, NULL,
                            "PERR, unknown reason code %u\n", PERR_DFLAGS(i));
                        goto done; /* XXX: stats?? */
                }
                ieee80211_mesh_rt_flush_peer(vap, PERR_DADDR(i));
                KASSERT(j < 32, ("PERR, error ndest >= 32 (%u)", j));
        }
        if (j == 0) {
                IEEE80211_DISCARD(vap, IEEE80211_MSG_HWMP, wh, NULL, "%s",
                    "PERR not accepted");
                goto done; /* XXX: stats?? */
        }

        /*
         * Propagate the PERR if we previously found it on our routing table.
         */
        if (forward && perr->perr_ttl > 1) {
                IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
                    "propagate PERR from %6D", wh->i_addr2, ":");
                pperr->perr_ndests = j;
                pperr->perr_ttl--;
                hwmp_send_perr(vap, broadcastaddr, pperr);
        }
done:
        if (pperr != NULL)
                IEEE80211_FREE(pperr, M_80211_MESH_PERR);
}
#undef  PERR_DFLAGS
#undef  PERR_DADDR
#undef  PERR_DSEQ
#undef  PERR_DEXTADDR

static int
hwmp_send_perr(struct ieee80211vap *vap,
    const uint8_t da[IEEE80211_ADDR_LEN],
    struct ieee80211_meshperr_ie *perr)
{
        struct ieee80211_hwmp_state *hs = vap->iv_hwmp;
        int i;
        uint8_t length = 0;

        /*
         * Enforce PERR interval.
         */
        if (ratecheck(&hs->hs_lastperr, &ieee80211_hwmp_perrminint) == 0)
                return EALREADY;
        getmicrouptime(&hs->hs_lastperr);

        /*
         * mesh perr action frame format
         *     [6] da
         *     [6] sa
         *     [6] addr3 = sa
         *     [1] action
         *     [1] category
         *     [tlv] mesh path error
         */
        perr->perr_ie = IEEE80211_ELEMID_MESHPERR;
        length = IEEE80211_MESHPERR_BASE_SZ;
        for (i = 0; i<perr->perr_ndests; i++) {
                if (perr->perr_dests[i].dest_flags &
                    IEEE80211_MESHPERR_FLAGS_AE) {
                        length += IEEE80211_MESHPERR_DEST_SZ_AE;
                        continue ;
                }
                length += IEEE80211_MESHPERR_DEST_SZ;
        }
        perr->perr_len =length;
        return hwmp_send_action(vap, da, (uint8_t *)perr, perr->perr_len+2);
}

/*
 * Called from the rest of the net80211 code (mesh code for example).
 * NB: IEEE80211_REASON_MESH_PERR_DEST_UNREACH can be trigger by the fact that
 * a mesh STA is unable to forward an MSDU/MMPDU to a next-hop mesh STA.
 */
#define PERR_DFLAGS(n)          perr.perr_dests[n].dest_flags
#define PERR_DADDR(n)           perr.perr_dests[n].dest_addr
#define PERR_DSEQ(n)            perr.perr_dests[n].dest_seq
#define PERR_DEXTADDR(n)        perr.perr_dests[n].dest_ext_addr
#define PERR_DRCODE(n)          perr.perr_dests[n].dest_rcode
static void
hwmp_senderror(struct ieee80211vap *vap,
    const uint8_t addr[IEEE80211_ADDR_LEN],
    struct ieee80211_mesh_route *rt, int rcode)
{
        struct ieee80211_mesh_state *ms = vap->iv_mesh;
        struct ieee80211_hwmp_route *hr = NULL;
        struct ieee80211_meshperr_ie perr;

        if (rt != NULL)
                hr = IEEE80211_MESH_ROUTE_PRIV(rt,
                    struct ieee80211_hwmp_route);

        perr.perr_ndests = 1;
        perr.perr_ttl = ms->ms_ttl;
        PERR_DFLAGS(0) = 0;
        PERR_DRCODE(0) = rcode;

        switch (rcode) {
        case IEEE80211_REASON_MESH_PERR_NO_FI:
                IEEE80211_ADDR_COPY(PERR_DADDR(0), addr);
                PERR_DSEQ(0) = 0; /* reserved */
                break;
        case IEEE80211_REASON_MESH_PERR_NO_PROXY:
                KASSERT(rt != NULL, ("no proxy info for sending PERR"));
                KASSERT(rt->rt_flags & IEEE80211_MESHRT_FLAGS_PROXY,
                    ("route is not marked proxy"));
                PERR_DFLAGS(0) |= IEEE80211_MESHPERR_FLAGS_AE;
                IEEE80211_ADDR_COPY(PERR_DADDR(0), vap->iv_myaddr);
                PERR_DSEQ(0) = rt->rt_ext_seq;
                IEEE80211_ADDR_COPY(PERR_DEXTADDR(0), addr);
                break;
        case IEEE80211_REASON_MESH_PERR_DEST_UNREACH:
                KASSERT(rt != NULL, ("no route info for sending PERR"));
                IEEE80211_ADDR_COPY(PERR_DADDR(0), addr);
                PERR_DSEQ(0) = hr->hr_seq;
                break;
        default:
                KASSERT(0, ("unknown reason code for HWMP PERR (%u)", rcode));
        }
        hwmp_send_perr(vap, broadcastaddr, &perr);
}
#undef  PERR_DFLAGS
#undef  PEER_DADDR
#undef  PERR_DSEQ
#undef  PERR_DEXTADDR
#undef  PERR_DRCODE

static void
hwmp_recv_rann(struct ieee80211vap *vap, struct ieee80211_node *ni,
    const struct ieee80211_frame *wh, const struct ieee80211_meshrann_ie *rann)
{
        struct ieee80211_mesh_state *ms = vap->iv_mesh;
        struct ieee80211_hwmp_state *hs = vap->iv_hwmp;
        struct ieee80211_mesh_route *rt = NULL;
        struct ieee80211_hwmp_route *hr;
        struct ieee80211_meshpreq_ie preq;
        struct ieee80211_meshrann_ie prann;

        if (IEEE80211_ADDR_EQ(rann->rann_addr, vap->iv_myaddr))
                return;

        rt = ieee80211_mesh_rt_find(vap, rann->rann_addr);
        if (rt != NULL && rt->rt_flags & IEEE80211_MESHRT_FLAGS_VALID) {
                hr = IEEE80211_MESH_ROUTE_PRIV(rt, struct ieee80211_hwmp_route);

                /* Acceptance criteria: if RANN.seq < stored seq, discard RANN */
                if (HWMP_SEQ_LT(rann->rann_seq, hr->hr_seq)) {
                        IEEE80211_DISCARD(vap, IEEE80211_MSG_HWMP, wh, NULL,
                        "RANN seq %u < %u", rann->rann_seq, hr->hr_seq);
                        return;
                }

                /* Acceptance criteria: if RANN.seq == stored seq AND
                * RANN.metric > stored metric, discard RANN */
                if (HWMP_SEQ_EQ(rann->rann_seq, hr->hr_seq) &&
                rann->rann_metric > rt->rt_metric) {
                        IEEE80211_DISCARD(vap, IEEE80211_MSG_HWMP, wh, NULL,
                        "RANN metric %u > %u", rann->rann_metric, rt->rt_metric);
                        return;
                }
        }

        /* RANN ACCEPTED */

        ieee80211_hwmp_rannint = rann->rann_interval; /* XXX: mtx lock? */

        if (rt == NULL) {
                rt = ieee80211_mesh_rt_add(vap, rann->rann_addr);
                if (rt == NULL) {
                        IEEE80211_DISCARD(vap, IEEE80211_MSG_HWMP, wh, NULL,
                            "unable to add mac for RANN root %6D",
                            rann->rann_addr, ":");
                            vap->iv_stats.is_mesh_rtaddfailed++;
                        return;
                }
        }
        hr = IEEE80211_MESH_ROUTE_PRIV(rt, struct ieee80211_hwmp_route);
        /* Check if root is a mesh gate, mark it */
        if (rann->rann_flags & IEEE80211_MESHRANN_FLAGS_GATE) {
                struct ieee80211_mesh_gate_route *gr;

                rt->rt_flags |= IEEE80211_MESHRT_FLAGS_GATE;
                gr = ieee80211_mesh_mark_gate(vap, rann->rann_addr,
                        rt);
                gr->gr_lastseq = 0; /* NOT GANN */
        }
        /* discovery timeout */
        ieee80211_mesh_rt_update(rt,
            ticks_to_msecs(ieee80211_hwmp_roottimeout));

        preq.preq_flags = IEEE80211_MESHPREQ_FLAGS_AM;
        preq.preq_hopcount = 0;
        preq.preq_ttl = ms->ms_ttl;
        preq.preq_id = 0; /* reserved */
        IEEE80211_ADDR_COPY(preq.preq_origaddr, vap->iv_myaddr);
        preq.preq_origseq = ++hs->hs_seq;
        preq.preq_lifetime = ieee80211_hwmp_roottimeout;
        preq.preq_metric = IEEE80211_MESHLMETRIC_INITIALVAL;
        preq.preq_tcount = 1;
        preq.preq_targets[0].target_flags = IEEE80211_MESHPREQ_TFLAGS_TO;
        /* NB: IEEE80211_MESHPREQ_TFLAGS_USN = 0 implicitly implied */
        IEEE80211_ADDR_COPY(preq.preq_targets[0].target_addr, rann->rann_addr);
        preq.preq_targets[0].target_seq = rann->rann_seq;
        /* XXX: if rootconfint have not passed, we built this preq in vain */
        hwmp_send_preq(vap, wh->i_addr2, &preq, &hr->hr_lastrootconf,
            &ieee80211_hwmp_rootconfint);

        /* propagate a RANN */
        if (rt->rt_flags & IEEE80211_MESHRT_FLAGS_VALID &&
            rann->rann_ttl > 1 &&
            ms->ms_flags & IEEE80211_MESHFLAGS_FWD) {
                hr->hr_seq = rann->rann_seq;
                memcpy(&prann, rann, sizeof(prann));
                prann.rann_hopcount += 1;
                prann.rann_ttl -= 1;
                prann.rann_metric += ms->ms_pmetric->mpm_metric(ni);
                hwmp_send_rann(vap, broadcastaddr, &prann);
        }
}

static int
hwmp_send_rann(struct ieee80211vap *vap,
    const uint8_t da[IEEE80211_ADDR_LEN],
    struct ieee80211_meshrann_ie *rann)
{
        /*
         * mesh rann action frame format
         *     [6] da
         *     [6] sa
         *     [6] addr3 = sa
         *     [1] action
         *     [1] category
         *     [tlv] root announcement
         */
        rann->rann_ie = IEEE80211_ELEMID_MESHRANN;
        rann->rann_len = IEEE80211_MESHRANN_BASE_SZ;
        return hwmp_send_action(vap, da, (uint8_t *)rann, rann->rann_len + 2);
}

#define PREQ_TFLAGS(n)  preq.preq_targets[n].target_flags
#define PREQ_TADDR(n)   preq.preq_targets[n].target_addr
#define PREQ_TSEQ(n)    preq.preq_targets[n].target_seq
static void
hwmp_rediscover_cb(void *arg)
{
        struct ieee80211_mesh_route *rt = arg;
        struct ieee80211vap *vap = rt->rt_vap;
        struct ieee80211_hwmp_state *hs = vap->iv_hwmp;
        struct ieee80211_mesh_state *ms = vap->iv_mesh;
        struct ieee80211_hwmp_route *hr;
        struct ieee80211_meshpreq_ie preq; /* Optimize: storing first preq? */

        if ((rt->rt_flags & IEEE80211_MESHRT_FLAGS_VALID))
                return ; /* nothing to do */

        hr = IEEE80211_MESH_ROUTE_PRIV(rt, struct ieee80211_hwmp_route);
        if (hr->hr_preqretries >=
                ieee80211_hwmp_maxpreq_retries) {
                IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_ANY,
                        rt->rt_dest, "%s",
                        "max number of discovery, send queued frames to GATE");
                ieee80211_mesh_forward_to_gates(vap, rt);
                vap->iv_stats.is_mesh_fwd_nopath++;
                return ; /* XXX: flush queue? */
        }

        hr->hr_preqretries++;

        IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_HWMP, rt->rt_dest,
            "start path rediscovery , target seq %u", hr->hr_seq);
        /*
         * Try to discover the path for this node.
         * Group addressed PREQ Case A
         */
        preq.preq_flags = 0;
        preq.preq_hopcount = 0;
        preq.preq_ttl = ms->ms_ttl;
        preq.preq_id = ++hs->hs_preqid;
        IEEE80211_ADDR_COPY(preq.preq_origaddr, vap->iv_myaddr);
        preq.preq_origseq = hr->hr_origseq;
        preq.preq_lifetime = ticks_to_msecs(ieee80211_hwmp_pathtimeout);
        preq.preq_metric = IEEE80211_MESHLMETRIC_INITIALVAL;
        preq.preq_tcount = 1;
        IEEE80211_ADDR_COPY(PREQ_TADDR(0), rt->rt_dest);
        PREQ_TFLAGS(0) = 0;
        if (ieee80211_hwmp_targetonly)
                PREQ_TFLAGS(0) |= IEEE80211_MESHPREQ_TFLAGS_TO;
        PREQ_TFLAGS(0) |= IEEE80211_MESHPREQ_TFLAGS_USN;
        PREQ_TSEQ(0) = 0; /* RESERVED when USN flag is set */
        /* XXX check return value */
        hwmp_send_preq(vap, broadcastaddr, &preq, &hr->hr_lastpreq,
            &ieee80211_hwmp_preqminint);
        callout_reset(&rt->rt_discovery,
                ieee80211_hwmp_net_diameter_traversaltime * 2,
                hwmp_rediscover_cb, rt);
}

static struct ieee80211_node *
hwmp_discover(struct ieee80211vap *vap,
    const uint8_t dest[IEEE80211_ADDR_LEN], struct mbuf *m)
{
        struct ieee80211_hwmp_state *hs = vap->iv_hwmp;
        struct ieee80211_mesh_state *ms = vap->iv_mesh;
        struct ieee80211_mesh_route *rt = NULL;
        struct ieee80211_hwmp_route *hr;
        struct ieee80211_meshpreq_ie preq;
        struct ieee80211_node *ni;
        int sendpreq = 0;

        KASSERT(vap->iv_opmode == IEEE80211_M_MBSS,
            ("not a mesh vap, opmode %d", vap->iv_opmode));

        KASSERT(!IEEE80211_ADDR_EQ(vap->iv_myaddr, dest),
            ("%s: discovering self!", __func__));

        ni = NULL;
        if (!IEEE80211_IS_MULTICAST(dest)) {
                rt = ieee80211_mesh_rt_find(vap, dest);
                if (rt == NULL) {
                        rt = ieee80211_mesh_rt_add(vap, dest);
                        if (rt == NULL) {
                                IEEE80211_DPRINTF(vap, IEEE80211_MSG_HWMP,
                                    "unable to add discovery path to %6D",
                                    dest, ":");
                                vap->iv_stats.is_mesh_rtaddfailed++;
                                goto done;
                        }
                }
                hr = IEEE80211_MESH_ROUTE_PRIV(rt,
                    struct ieee80211_hwmp_route);
                if (rt->rt_flags & IEEE80211_MESHRT_FLAGS_DISCOVER) {
                        IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_HWMP, dest,
                            "%s", "already discovering queue frame until path found");
                        sendpreq = 1;
                        goto done;
                }
                if ((rt->rt_flags & IEEE80211_MESHRT_FLAGS_VALID) == 0) {
                        if (hr->hr_lastdiscovery != 0 &&
                            (ticks - hr->hr_lastdiscovery <
                            (ieee80211_hwmp_net_diameter_traversaltime * 2))) {
                                IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
                                    dest, NULL, "%s",
                                    "too frequent discovery requeust");
                                sendpreq = 1;
                                goto done;
                        }
                        hr->hr_lastdiscovery = ticks;
                        if (hr->hr_preqretries >=
                            ieee80211_hwmp_maxpreq_retries) {
                                IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
                                    dest, NULL, "%s",
                                    "no valid path , max number of discovery");
                                vap->iv_stats.is_mesh_fwd_nopath++;
                                goto done;
                        }
                        rt->rt_flags = IEEE80211_MESHRT_FLAGS_DISCOVER;
                        hr->hr_preqretries++;
                        if (hr->hr_origseq == 0)
                                hr->hr_origseq = ++hs->hs_seq;
                        rt->rt_metric = IEEE80211_MESHLMETRIC_INITIALVAL;
                        sendpreq = 1;
                        IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_HWMP, dest,
                            "start path discovery (src %s), target seq %u",
                            m == NULL ? "<none>" : ether_sprintf(
                            mtod(m, struct ether_header *)->ether_shost),
                            hr->hr_seq);
                        /*
                         * Try to discover the path for this node.
                         * Group addressed PREQ Case A
                         */
                        preq.preq_flags = 0;
                        preq.preq_hopcount = 0;
                        preq.preq_ttl = ms->ms_ttl;
                        preq.preq_id = ++hs->hs_preqid;
                        IEEE80211_ADDR_COPY(preq.preq_origaddr, vap->iv_myaddr);
                        preq.preq_origseq = hr->hr_origseq;
                        preq.preq_lifetime =
                            ticks_to_msecs(ieee80211_hwmp_pathtimeout);
                        preq.preq_metric = IEEE80211_MESHLMETRIC_INITIALVAL;
                        preq.preq_tcount = 1;
                        IEEE80211_ADDR_COPY(PREQ_TADDR(0), dest);
                        PREQ_TFLAGS(0) = 0;
                        if (ieee80211_hwmp_targetonly)
                                PREQ_TFLAGS(0) |= IEEE80211_MESHPREQ_TFLAGS_TO;
                        PREQ_TFLAGS(0) |= IEEE80211_MESHPREQ_TFLAGS_USN;
                        PREQ_TSEQ(0) = 0; /* RESERVED when USN flag is set */
                        /* XXX check return value */
                        hwmp_send_preq(vap, broadcastaddr, &preq,
                            &hr->hr_lastpreq, &ieee80211_hwmp_preqminint);
                        callout_reset(&rt->rt_discovery,
                            ieee80211_hwmp_net_diameter_traversaltime * 2,
                            hwmp_rediscover_cb, rt);
                }
                if (rt->rt_flags & IEEE80211_MESHRT_FLAGS_VALID)
                        ni = ieee80211_find_txnode(vap, rt->rt_nexthop);
        } else {
                ni = ieee80211_find_txnode(vap, dest);
                /* NB: if null then we leak mbuf */
                KASSERT(ni != NULL, ("leak mcast frame"));
                return ni;
        }
done:
        if (ni == NULL && m != NULL) {
                if (sendpreq) {
                        struct ieee80211com *ic = vap->iv_ic;
                        /*
                         * Queue packet for transmit when path discovery
                         * completes.  If discovery never completes the
                         * frame will be flushed by way of the aging timer.
                         */
                        IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_HWMP, dest,
                            "%s", "queue frame until path found");
                        MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
                        m->m_pkthdr.rcvif = (void *)(uintptr_t)
                            ieee80211_mac_hash(ic, dest);
                        /* XXX age chosen randomly */
                        ieee80211_ageq_append(&ic->ic_stageq, m,
                            IEEE80211_INACT_WAIT);
                } else {
                        IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_HWMP,
                            dest, NULL, "%s", "no valid path to this node");
                        m_freem(m);
                }
        }
        return ni;
}
#undef  PREQ_TFLAGS
#undef  PREQ_TADDR
#undef  PREQ_TSEQ

static int
hwmp_ioctl_get80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
{
        struct ieee80211_hwmp_state *hs = vap->iv_hwmp;
        int error;

        if (vap->iv_opmode != IEEE80211_M_MBSS)
                return ENOSYS;
        error = 0;
        switch (ireq->i_type) {
        case IEEE80211_IOC_HWMP_ROOTMODE:
                ireq->i_val = hs->hs_rootmode;
                break;
        case IEEE80211_IOC_HWMP_MAXHOPS:
                ireq->i_val = hs->hs_maxhops;
                break;
        default:
                return ENOSYS;
        }
        return error;
}
IEEE80211_IOCTL_GET(hwmp, hwmp_ioctl_get80211);

static int
hwmp_ioctl_set80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
{
        struct ieee80211_hwmp_state *hs = vap->iv_hwmp;
        int error;

        if (vap->iv_opmode != IEEE80211_M_MBSS)
                return ENOSYS;
        error = 0;
        switch (ireq->i_type) {
        case IEEE80211_IOC_HWMP_ROOTMODE:
                if (ireq->i_val < 0 || ireq->i_val > 3)
                        return EINVAL;
                hs->hs_rootmode = ireq->i_val;
                hwmp_rootmode_setup(vap);
                break;
        case IEEE80211_IOC_HWMP_MAXHOPS:
                if (ireq->i_val <= 0 || ireq->i_val > 255)
                        return EINVAL;
                hs->hs_maxhops = ireq->i_val;
                break;
        default:
                return ENOSYS;
        }
        return error;
}
IEEE80211_IOCTL_SET(hwmp, hwmp_ioctl_set80211);