ieee80211_adhoc.c

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/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2007-2009 Sam Leffler, Errno Consulting
 * All rights reserved.
 *
 * 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 ``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 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.
 */
 
#include <sys/cdefs.h>
#ifdef __FreeBSD__
__FBSDID("$FreeBSD$");
#endif
 
/*
 * IEEE 802.11 IBSS mode support.
 */
#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_var.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_adhoc.h>
#include <net80211/ieee80211_input.h>
#ifdef IEEE80211_SUPPORT_SUPERG
#include <net80211/ieee80211_superg.h>
#endif
#ifdef IEEE80211_SUPPORT_TDMA
#include <net80211/ieee80211_tdma.h>
#endif
#include <net80211/ieee80211_sta.h>
 
#define IEEE80211_RATE2MBS(r)   (((r) & IEEE80211_RATE_VAL) / 2)
 
static  void adhoc_vattach(struct ieee80211vap *);
static  int adhoc_newstate(struct ieee80211vap *, enum ieee80211_state, int);
static int adhoc_input(struct ieee80211_node *, struct mbuf *,
            const struct ieee80211_rx_stats *, int, int);
static void adhoc_recv_mgmt(struct ieee80211_node *, struct mbuf *,
        int subtype, const struct ieee80211_rx_stats *, int, int);
static void ahdemo_recv_mgmt(struct ieee80211_node *, struct mbuf *,
            int subtype, const struct ieee80211_rx_stats *rxs, int, int);
static void adhoc_recv_ctl(struct ieee80211_node *, struct mbuf *, int subtype);
 
void
ieee80211_adhoc_attach(struct ieee80211com *ic)
{
        ic->ic_vattach[IEEE80211_M_IBSS] = adhoc_vattach;
        ic->ic_vattach[IEEE80211_M_AHDEMO] = adhoc_vattach;
}
 
void
ieee80211_adhoc_detach(struct ieee80211com *ic)
{
}
 
static void
adhoc_vdetach(struct ieee80211vap *vap)
{
}
 
static void
adhoc_vattach(struct ieee80211vap *vap)
{
        vap->iv_newstate = adhoc_newstate;
        vap->iv_input = adhoc_input;
        if (vap->iv_opmode == IEEE80211_M_IBSS)
                vap->iv_recv_mgmt = adhoc_recv_mgmt;
        else
                vap->iv_recv_mgmt = ahdemo_recv_mgmt;
        vap->iv_recv_ctl = adhoc_recv_ctl;
        vap->iv_opdetach = adhoc_vdetach;
#ifdef IEEE80211_SUPPORT_TDMA
        /*
         * Throw control to tdma support.  Note we do this
         * after setting up our callbacks so it can piggyback
         * on top of us.
         */
        if (vap->iv_caps & IEEE80211_C_TDMA)
                ieee80211_tdma_vattach(vap);
#endif
}
 
static void
sta_leave(void *arg, struct ieee80211_node *ni)
{
        struct ieee80211vap *vap = ni->ni_vap;
 
        if (ni != vap->iv_bss)
                ieee80211_node_leave(ni);
}
 
/*
 * IEEE80211_M_IBSS+IEEE80211_M_AHDEMO vap state machine handler.
 */
static int
adhoc_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
{
        struct ieee80211com *ic = vap->iv_ic;
        struct ieee80211_node *ni;
        enum ieee80211_state ostate;
 
        IEEE80211_LOCK_ASSERT(vap->iv_ic);
 
        ostate = vap->iv_state;
        IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
            __func__, ieee80211_state_name[ostate],
            ieee80211_state_name[nstate], arg);
        vap->iv_state = nstate;                 /* state transition */
        if (ostate != IEEE80211_S_SCAN)
                ieee80211_cancel_scan(vap);     /* background scan */
        ni = vap->iv_bss;                       /* NB: no reference held */
        switch (nstate) {
        case IEEE80211_S_INIT:
                switch (ostate) {
                case IEEE80211_S_SCAN:
                        ieee80211_cancel_scan(vap);
                        break;
                default:
                        break;
                }
                if (ostate != IEEE80211_S_INIT) {
                        /* NB: optimize INIT -> INIT case */
                        ieee80211_reset_bss(vap);
                }
                break;
        case IEEE80211_S_SCAN:
                switch (ostate) {
                case IEEE80211_S_RUN:           /* beacon miss */
                        /* purge station table; entries are stale */
                        ieee80211_iterate_nodes_vap(&ic->ic_sta, vap,
                            sta_leave, NULL);
                        /* fall thru... */
                case IEEE80211_S_INIT:
                        if (vap->iv_des_chan != IEEE80211_CHAN_ANYC &&
                            !IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
                                /*
                                 * Already have a channel; bypass the
                                 * scan and startup immediately.
                                 */
                                ieee80211_create_ibss(vap,
                                    ieee80211_ht_adjust_channel(ic,
                                    vap->iv_des_chan, vap->iv_flags_ht));
                                break;
                        }
                        /*
                         * Initiate a scan.  We can come here as a result
                         * of an IEEE80211_IOC_SCAN_REQ too in which case
                         * the vap will be marked with IEEE80211_FEXT_SCANREQ
                         * and the scan request parameters will be present
                         * in iv_scanreq.  Otherwise we do the default.
                         */
                        if (vap->iv_flags_ext & IEEE80211_FEXT_SCANREQ) {
                                ieee80211_check_scan(vap,
                                    vap->iv_scanreq_flags,
                                    vap->iv_scanreq_duration,
                                    vap->iv_scanreq_mindwell,
                                    vap->iv_scanreq_maxdwell,
                                    vap->iv_scanreq_nssid, vap->iv_scanreq_ssid);
                                vap->iv_flags_ext &= ~IEEE80211_FEXT_SCANREQ;
                        } else
                                ieee80211_check_scan_current(vap);
                        break;
                case IEEE80211_S_SCAN:
                        /*
                         * This can happen because of a change in state
                         * that requires a reset.  Trigger a new scan
                         * unless we're in manual roaming mode in which
                         * case an application must issue an explicit request.
                         */
                        if (vap->iv_roaming == IEEE80211_ROAMING_AUTO)
                                ieee80211_check_scan_current(vap);
                        break;
                default:
                        goto invalid;
                }
                break;
        case IEEE80211_S_RUN:
                if (vap->iv_flags & IEEE80211_F_WPA) {
                        /* XXX validate prerequisites */
                }
                switch (ostate) {
                case IEEE80211_S_INIT:
                        /*
                         * Already have a channel; bypass the
                         * scan and startup immediately.
                         * Note that ieee80211_create_ibss will call
                         * back to do a RUN->RUN state change.
                         */
                        ieee80211_create_ibss(vap,
                            ieee80211_ht_adjust_channel(ic,
                                ic->ic_curchan, vap->iv_flags_ht));
                        /* NB: iv_bss is changed on return */
                        ni = vap->iv_bss;
                        break;
                case IEEE80211_S_SCAN:
#ifdef IEEE80211_DEBUG
                        if (ieee80211_msg_debug(vap)) {
                                ieee80211_note(vap,
                                    "synchronized with %s ssid ",
                                    ether_sprintf(ni->ni_bssid));
                                ieee80211_print_essid(vap->iv_bss->ni_essid,
                                    ni->ni_esslen);
                                /* XXX MCS/HT */
                                printf(" channel %d start %uMb\n",
                                    ieee80211_chan2ieee(ic, ic->ic_curchan),
                                    IEEE80211_RATE2MBS(ni->ni_txrate));
                        }
#endif
                        break;
                case IEEE80211_S_RUN:   /* IBSS merge */
                        break;
                default:
                        goto invalid;
                }
                /*
                 * When 802.1x is not in use mark the port authorized
                 * at this point so traffic can flow.
                 */
                if (ni->ni_authmode != IEEE80211_AUTH_8021X)
                        ieee80211_node_authorize(ni);
                /*
                 * Fake association when joining an existing bss.
                 */
                if (!IEEE80211_ADDR_EQ(ni->ni_macaddr, vap->iv_myaddr) &&
                    ic->ic_newassoc != NULL)
                        ic->ic_newassoc(ni, ostate != IEEE80211_S_RUN);
                break;
        case IEEE80211_S_SLEEP:
                vap->iv_sta_ps(vap, 0);
                break;
        default:
        invalid:
                IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE,
                    "%s: unexpected state transition %s -> %s\n", __func__,
                    ieee80211_state_name[ostate], ieee80211_state_name[nstate]);
                break;
        }
        return 0;
}
 
/*
 * Decide if a received management frame should be
 * printed when debugging is enabled.  This filters some
 * of the less interesting frames that come frequently
 * (e.g. beacons).
 */
static __inline int
doprint(struct ieee80211vap *vap, int subtype)
{
        switch (subtype) {
        case IEEE80211_FC0_SUBTYPE_BEACON:
                return (vap->iv_ic->ic_flags & IEEE80211_F_SCAN);
        case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
                return 1;
        }
        return 1;
}
 
/*
 * Process a received frame.  The node associated with the sender
 * should be supplied.  If nothing was found in the node table then
 * the caller is assumed to supply a reference to iv_bss instead.
 * The RSSI and a timestamp are also supplied.  The RSSI data is used
 * during AP scanning to select a AP to associate with; it can have
 * any units so long as values have consistent units and higher values
 * mean ``better signal''.  The receive timestamp is currently not used
 * by the 802.11 layer.
 */
static int
adhoc_input(struct ieee80211_node *ni, struct mbuf *m,
    const struct ieee80211_rx_stats *rxs, int rssi, int nf)
{
        struct ieee80211vap *vap = ni->ni_vap;
        struct ieee80211com *ic = ni->ni_ic;
        struct ifnet *ifp = vap->iv_ifp;
        struct ieee80211_frame *wh;
        struct ieee80211_key *key;
        struct ether_header *eh;
        int hdrspace, need_tap = 1;     /* mbuf need to be tapped. */   
        uint8_t dir, type, subtype, qos;
        uint8_t *bssid;
        int is_hw_decrypted = 0;
        int has_decrypted = 0;
 
        /*
         * Some devices do hardware decryption all the way through
         * to pretending the frame wasn't encrypted in the first place.
         * So, tag it appropriately so it isn't discarded inappropriately.
         */
        if ((rxs != NULL) && (rxs->c_pktflags & IEEE80211_RX_F_DECRYPTED))
                is_hw_decrypted = 1;
 
        if (m->m_flags & M_AMPDU_MPDU) {
                /*
                 * Fastpath for A-MPDU reorder q resubmission.  Frames
                 * w/ M_AMPDU_MPDU marked have already passed through
                 * here but were received out of order and been held on
                 * the reorder queue.  When resubmitted they are marked
                 * with the M_AMPDU_MPDU flag and we can bypass most of
                 * the normal processing.
                 */
                wh = mtod(m, struct ieee80211_frame *);
                type = IEEE80211_FC0_TYPE_DATA;
                dir = wh->i_fc[1] & IEEE80211_FC1_DIR_MASK;
                subtype = IEEE80211_FC0_SUBTYPE_QOS;
                hdrspace = ieee80211_hdrspace(ic, wh);  /* XXX optimize? */
                goto resubmit_ampdu;
        }
 
        KASSERT(ni != NULL, ("null node"));
        ni->ni_inact = ni->ni_inact_reload;
 
        type = -1;                      /* undefined */
 
        if (m->m_pkthdr.len < sizeof(struct ieee80211_frame_min)) {
                IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
                    ni->ni_macaddr, NULL,
                    "too short (1): len %u", m->m_pkthdr.len);
                vap->iv_stats.is_rx_tooshort++;
                goto out;
        }
        /*
         * Bit of a cheat here, we use a pointer for a 3-address
         * frame format but don't reference fields past outside
         * ieee80211_frame_min w/o first validating the data is
         * present.
         */
        wh = mtod(m, struct ieee80211_frame *);
 
        if ((wh->i_fc[0] & IEEE80211_FC0_VERSION_MASK) !=
            IEEE80211_FC0_VERSION_0) {
                IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
                    ni->ni_macaddr, NULL, "wrong version, fc %02x:%02x",
                    wh->i_fc[0], wh->i_fc[1]);
                vap->iv_stats.is_rx_badversion++;
                goto err;
        }
 
        dir = wh->i_fc[1] & IEEE80211_FC1_DIR_MASK;
        type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
        subtype = wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK;
        if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
                if (dir != IEEE80211_FC1_DIR_NODS)
                        bssid = wh->i_addr1;
                else if (type == IEEE80211_FC0_TYPE_CTL)
                        bssid = wh->i_addr1;
                else {
                        if (m->m_pkthdr.len < sizeof(struct ieee80211_frame)) {
                                IEEE80211_DISCARD_MAC(vap,
                                    IEEE80211_MSG_ANY, ni->ni_macaddr,
                                    NULL, "too short (2): len %u",
                                    m->m_pkthdr.len);
                                vap->iv_stats.is_rx_tooshort++;
                                goto out;
                        }
                        bssid = wh->i_addr3;
                }
                /*
                 * Validate the bssid.
                 */
                if (!(type == IEEE80211_FC0_TYPE_MGT &&
                     (subtype == IEEE80211_FC0_SUBTYPE_BEACON ||
                      subtype == IEEE80211_FC0_SUBTYPE_PROBE_RESP)) &&
                    !IEEE80211_ADDR_EQ(bssid, vap->iv_bss->ni_bssid) &&
                    !IEEE80211_ADDR_EQ(bssid, ifp->if_broadcastaddr)) {
                        /* not interested in */
                        IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
                            bssid, NULL, "%s", "not to bss");
                        vap->iv_stats.is_rx_wrongbss++;
                        goto out;
                }
                /*
                 * Data frame, cons up a node when it doesn't
                 * exist. This should probably done after an ACL check.
                 */
                if (type == IEEE80211_FC0_TYPE_DATA &&
                    ni == vap->iv_bss &&
                    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
                        /*
                         * Beware of frames that come in too early; we
                         * can receive broadcast frames and creating sta
                         * entries will blow up because there is no bss
                         * channel yet.
                         */
                        if (vap->iv_state != IEEE80211_S_RUN) {
                                IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
                                    wh, "data", "not in RUN state (%s)",
                                    ieee80211_state_name[vap->iv_state]);
                                vap->iv_stats.is_rx_badstate++;
                                goto err;
                        }
                        /*
                         * Fake up a node for this newly discovered member
                         * of the IBSS.
                         *
                         * Note: This doesn't "upgrade" the node to 11n;
                         * that will happen after a probe request/response
                         * exchange.
                         */
                        ni = ieee80211_fakeup_adhoc_node(vap, wh->i_addr2);
                        if (ni == NULL) {
                                /* NB: stat kept for alloc failure */
                                goto err;
                        }
                }
                IEEE80211_RSSI_LPF(ni->ni_avgrssi, rssi);
                ni->ni_noise = nf;
                if (IEEE80211_HAS_SEQ(type, subtype) &&
                    IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
                        uint8_t tid = ieee80211_gettid(wh);
                        if (IEEE80211_QOS_HAS_SEQ(wh) &&
                            TID_TO_WME_AC(tid) >= WME_AC_VI)
                                ic->ic_wme.wme_hipri_traffic++;
                        if (! ieee80211_check_rxseq(ni, wh, bssid, rxs))
                                goto out;
                }
        }
 
        switch (type) {
        case IEEE80211_FC0_TYPE_DATA:
                hdrspace = ieee80211_hdrspace(ic, wh);
                if (m->m_len < hdrspace &&
                    (m = m_pullup(m, hdrspace)) == NULL) {
                        IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
                            ni->ni_macaddr, NULL,
                            "data too short: expecting %u", hdrspace);
                        vap->iv_stats.is_rx_tooshort++;
                        goto out;               /* XXX */
                }
                if (dir != IEEE80211_FC1_DIR_NODS) {
                        IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
                            wh, "data", "incorrect dir 0x%x", dir);
                        vap->iv_stats.is_rx_wrongdir++;
                        goto out;
                }
                /* XXX no power-save support */
 
                /*
                 * Handle A-MPDU re-ordering.  If the frame is to be
                 * processed directly then ieee80211_ampdu_reorder
                 * will return 0; otherwise it has consumed the mbuf
                 * and we should do nothing more with it.
                 */
                if ((m->m_flags & M_AMPDU) &&
                    ieee80211_ampdu_reorder(ni, m, rxs) != 0) {
                        m = NULL;
                        goto out;
                }
        resubmit_ampdu:
 
                /*
                 * Handle privacy requirements.  Note that we
                 * must not be preempted from here until after
                 * we (potentially) call ieee80211_crypto_demic;
                 * otherwise we may violate assumptions in the
                 * crypto cipher modules used to do delayed update
                 * of replay sequence numbers.
                 */
                if (is_hw_decrypted || wh->i_fc[1] & IEEE80211_FC1_PROTECTED) {
                        if ((vap->iv_flags & IEEE80211_F_PRIVACY) == 0) {
                                /*
                                 * Discard encrypted frames when privacy is off.
                                 */
                                IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
                                    wh, "WEP", "%s", "PRIVACY off");
                                vap->iv_stats.is_rx_noprivacy++;
                                IEEE80211_NODE_STAT(ni, rx_noprivacy);
                                goto out;
                        }
                        if (ieee80211_crypto_decap(ni, m, hdrspace, &key) == 0) {
                                /* NB: stats+msgs handled in crypto_decap */
                                IEEE80211_NODE_STAT(ni, rx_wepfail);
                                goto out;
                        }
                        wh = mtod(m, struct ieee80211_frame *);
                        wh->i_fc[1] &= ~IEEE80211_FC1_PROTECTED;
                        has_decrypted = 1;
                } else {
                        /* XXX M_WEP and IEEE80211_F_PRIVACY */
                        key = NULL;
                }
 
                /*
                 * Save QoS bits for use below--before we strip the header.
                 */
                if (subtype == IEEE80211_FC0_SUBTYPE_QOS)
                        qos = ieee80211_getqos(wh)[0];
                else
                        qos = 0;
 
                /*
                 * Next up, any fragmentation.
                 */
                if (!IEEE80211_IS_MULTICAST(wh->i_addr1)) {
                        m = ieee80211_defrag(ni, m, hdrspace, has_decrypted);
                        if (m == NULL) {
                                /* Fragment dropped or frame not complete yet */
                                goto out;
                        }
                }
                wh = NULL;              /* no longer valid, catch any uses */
 
                /*
                 * Next strip any MSDU crypto bits.
                 */
                if (!ieee80211_crypto_demic(vap, key, m, 0)) {
                        IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
                            ni->ni_macaddr, "data", "%s", "demic error");
                        vap->iv_stats.is_rx_demicfail++;
                        IEEE80211_NODE_STAT(ni, rx_demicfail);
                        goto out;
                }
 
                /* copy to listener after decrypt */
                if (ieee80211_radiotap_active_vap(vap))
                        ieee80211_radiotap_rx(vap, m);
                need_tap = 0;
 
                /*
                 * Finally, strip the 802.11 header.
                 */
                m = ieee80211_decap(vap, m, hdrspace, qos);
                if (m == NULL) {
                        /* XXX mask bit to check for both */
                        /* don't count Null data frames as errors */
                        if (subtype == IEEE80211_FC0_SUBTYPE_NODATA ||
                            subtype == IEEE80211_FC0_SUBTYPE_QOS_NULL)
                                goto out;
                        IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
                            ni->ni_macaddr, "data", "%s", "decap error");
                        vap->iv_stats.is_rx_decap++;
                        IEEE80211_NODE_STAT(ni, rx_decap);
                        goto err;
                }
                if (!(qos & IEEE80211_QOS_AMSDU))
                        eh = mtod(m, struct ether_header *);
                else
                        eh = NULL;
                if (!ieee80211_node_is_authorized(ni)) {
                        /*
                         * Deny any non-PAE frames received prior to
                         * authorization.  For open/shared-key
                         * authentication the port is mark authorized
                         * after authentication completes.  For 802.1x
                         * the port is not marked authorized by the
                         * authenticator until the handshake has completed.
                         */
                        if (eh == NULL ||
                            eh->ether_type != htons(ETHERTYPE_PAE)) {
                                IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
                                    ni->ni_macaddr, "data", "unauthorized or "
                                    "unknown port: ether type 0x%x len %u",
                                    eh == NULL ? -1 : eh->ether_type,
                                    m->m_pkthdr.len);
                                vap->iv_stats.is_rx_unauth++;
                                IEEE80211_NODE_STAT(ni, rx_unauth);
                                goto err;
                        }
                } else {
                        /*
                         * When denying unencrypted frames, discard
                         * any non-PAE frames received without encryption.
                         */
                        if ((vap->iv_flags & IEEE80211_F_DROPUNENC) &&
                            ((has_decrypted == 0) && (m->m_flags & M_WEP) == 0) &&
                            (is_hw_decrypted == 0) &&
                            (eh == NULL ||
                             eh->ether_type != htons(ETHERTYPE_PAE))) {
                                /*
                                 * Drop unencrypted frames.
                                 */
                                vap->iv_stats.is_rx_unencrypted++;
                                IEEE80211_NODE_STAT(ni, rx_unencrypted);
                                goto out;
                        }
                }
                /* XXX require HT? */
                if (qos & IEEE80211_QOS_AMSDU) {
                        m = ieee80211_decap_amsdu(ni, m);
                        if (m == NULL)
                                return IEEE80211_FC0_TYPE_DATA;
                } else {
#ifdef IEEE80211_SUPPORT_SUPERG
                        m = ieee80211_decap_fastframe(vap, ni, m);
                        if (m == NULL)
                                return IEEE80211_FC0_TYPE_DATA;
#endif
                }
                if (dir == IEEE80211_FC1_DIR_DSTODS && ni->ni_wdsvap != NULL)
                        ieee80211_deliver_data(ni->ni_wdsvap, ni, m);
                else
                        ieee80211_deliver_data(vap, ni, m);
                return IEEE80211_FC0_TYPE_DATA;
 
        case IEEE80211_FC0_TYPE_MGT:
                vap->iv_stats.is_rx_mgmt++;
                IEEE80211_NODE_STAT(ni, rx_mgmt);
                if (dir != IEEE80211_FC1_DIR_NODS) {
                        IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
                            wh, "data", "incorrect dir 0x%x", dir);
                        vap->iv_stats.is_rx_wrongdir++;
                        goto err;
                }
                if (m->m_pkthdr.len < sizeof(struct ieee80211_frame)) {
                        IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
                            ni->ni_macaddr, "mgt", "too short: len %u",
                            m->m_pkthdr.len);
                        vap->iv_stats.is_rx_tooshort++;
                        goto out;
                }
#ifdef IEEE80211_DEBUG
                if ((ieee80211_msg_debug(vap) && doprint(vap, subtype)) ||
                    ieee80211_msg_dumppkts(vap)) {
                        if_printf(ifp, "received %s from %s rssi %d\n",
                            ieee80211_mgt_subtype_name(subtype),
                            ether_sprintf(wh->i_addr2), rssi);
                }
#endif
                if (wh->i_fc[1] & IEEE80211_FC1_PROTECTED) {
                        IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
                            wh, NULL, "%s", "WEP set but not permitted");
                        vap->iv_stats.is_rx_mgtdiscard++; /* XXX */
                        goto out;
                }
                vap->iv_recv_mgmt(ni, m, subtype, rxs, rssi, nf);
                goto out;
 
        case IEEE80211_FC0_TYPE_CTL:
                vap->iv_stats.is_rx_ctl++;
                IEEE80211_NODE_STAT(ni, rx_ctrl);
                vap->iv_recv_ctl(ni, m, subtype);
                goto out;
 
        default:
                IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
                    wh, "bad", "frame type 0x%x", type);
                /* should not come here */
                break;
        }
err:
        if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
out:
        if (m != NULL) {
                if (need_tap && ieee80211_radiotap_active_vap(vap))
                        ieee80211_radiotap_rx(vap, m);
                m_freem(m);
        }
        return type;
}
 
static int
is11bclient(const uint8_t *rates, const uint8_t *xrates)
{
        static const uint32_t brates = (1<<2*1)|(1<<2*2)|(1<<11)|(1<<2*11);
        int i;
 
        /* NB: the 11b clients we care about will not have xrates */
        if (xrates != NULL || rates == NULL)
                return 0;
        for (i = 0; i < rates[1]; i++) {
                int r = rates[2+i] & IEEE80211_RATE_VAL;
                if (r > 2*11 || ((1<<r) & brates) == 0)
                        return 0;
        }
        return 1;
}
 
static void
adhoc_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
        int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf)
{
        struct ieee80211vap *vap = ni->ni_vap;
        struct ieee80211com *ic = ni->ni_ic;
        struct ieee80211_channel *rxchan = ic->ic_curchan;
        struct ieee80211_frame *wh;
        uint8_t *frm, *efrm;
        uint8_t *ssid, *rates, *xrates;
#if 0
        int ht_state_change = 0;
#endif
 
        wh = mtod(m0, struct ieee80211_frame *);
        frm = (uint8_t *)&wh[1];
        efrm = mtod(m0, uint8_t *) + m0->m_len;
 
        IEEE80211_DPRINTF(vap, IEEE80211_MSG_INPUT | IEEE80211_MSG_DEBUG,
            "%s: recv mgmt frame, addr2=%6D, ni=%p (%6D) fc=%.02x %.02x\n",
            __func__,
            wh->i_addr2, ":",
            ni,
            ni->ni_macaddr, ":",
            wh->i_fc[0],
            wh->i_fc[1]);
        switch (subtype) {
        case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
        case IEEE80211_FC0_SUBTYPE_BEACON: {
                struct ieee80211_scanparams scan;
                struct ieee80211_channel *c;
                /*
                 * We process beacon/probe response
                 * frames to discover neighbors.
                 */ 
                if (rxs != NULL) {
                        c = ieee80211_lookup_channel_rxstatus(vap, rxs);
                        if (c != NULL)
                                rxchan = c;
                }
                if (ieee80211_parse_beacon(ni, m0, rxchan, &scan) != 0)
                        return;
                /*
                 * Count frame now that we know it's to be processed.
                 */
                if (subtype == IEEE80211_FC0_SUBTYPE_BEACON) {
                        vap->iv_stats.is_rx_beacon++;           /* XXX remove */
                        IEEE80211_NODE_STAT(ni, rx_beacons);
                } else
                        IEEE80211_NODE_STAT(ni, rx_proberesp);
                /*
                 * If scanning, just pass information to the scan module.
                 */
                if (ic->ic_flags & IEEE80211_F_SCAN) {
                        if (ic->ic_flags_ext & IEEE80211_FEXT_PROBECHAN) {
                                /*
                                 * Actively scanning a channel marked passive;
                                 * send a probe request now that we know there
                                 * is 802.11 traffic present.
                                 *
                                 * XXX check if the beacon we recv'd gives
                                 * us what we need and suppress the probe req
                                 */
                                ieee80211_probe_curchan(vap, 1);
                                ic->ic_flags_ext &= ~IEEE80211_FEXT_PROBECHAN;
                        }
                        ieee80211_add_scan(vap, rxchan, &scan, wh,
                            subtype, rssi, nf);
                        return;
                }
                if (scan.capinfo & IEEE80211_CAPINFO_IBSS) {
                        if (!IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
                                /*
                                 * Create a new entry in the neighbor table.
                                 *
                                 * XXX TODO:
                                 *
                                 * Here we're not scanning; so if we have an
                                 * SSID then make sure it matches our SSID.
                                 * Otherwise this code will match on all IBSS
                                 * beacons/probe requests for all SSIDs,
                                 * filling the node table with nodes that
                                 * aren't ours.
                                 */
                                if (ieee80211_ibss_node_check_new(ni, &scan)) {
                                        ni = ieee80211_add_neighbor(vap, wh, &scan);
                                        /*
                                         * Send a probe request so we announce 11n
                                         * capabilities.
                                         */
                                        ieee80211_send_probereq(ni, /* node */
                                            vap->iv_myaddr, /* SA */
                                            ni->ni_macaddr, /* DA */
                                            vap->iv_bss->ni_bssid, /* BSSID */
                                            vap->iv_bss->ni_essid,
                                            vap->iv_bss->ni_esslen); /* SSID */
                                } else
                                        ni = NULL;
 
                                /*
                                 * Send a probe request so we announce 11n
                                 * capabilities.
                                 *
                                 * Don't do this if we're scanning.
                                 */
                                if (! (ic->ic_flags & IEEE80211_F_SCAN))
                                        ieee80211_send_probereq(ni, /* node */
                                                vap->iv_myaddr, /* SA */
                                                ni->ni_macaddr, /* DA */
                                                vap->iv_bss->ni_bssid, /* BSSID */
                                                vap->iv_bss->ni_essid,
                                                vap->iv_bss->ni_esslen); /* SSID */
 
                        } else if (ni->ni_capinfo == 0) {
                                /*
                                 * Update faked node created on transmit.
                                 * Note this also updates the tsf.
                                 */
                                ieee80211_init_neighbor(ni, wh, &scan);
 
                                /*
                                 * Send a probe request so we announce 11n
                                 * capabilities.
                                 */
                                ieee80211_send_probereq(ni, /* node */
                                        vap->iv_myaddr, /* SA */
                                        ni->ni_macaddr, /* DA */
                                        vap->iv_bss->ni_bssid, /* BSSID */
                                        vap->iv_bss->ni_essid,
                                        vap->iv_bss->ni_esslen); /* SSID */
                        } else {
                                /*
                                 * Record tsf for potential resync.
                                 */
                                memcpy(ni->ni_tstamp.data, scan.tstamp,
                                        sizeof(ni->ni_tstamp));
                        }
                        /*
                         * This isn't enabled yet - otherwise it would
                         * update the HT parameters and channel width
                         * from any node, which could lead to lots of
                         * strange behaviour if the 11n nodes aren't
                         * exactly configured to match.
                         */
#if 0
                        if (scan.htcap != NULL && scan.htinfo != NULL &&
                            (vap->iv_flags_ht & IEEE80211_FHT_HT)) {
                                ieee80211_ht_updateparams(ni,
                                    scan.htcap, scan.htinfo));
                                if (ieee80211_ht_updateparams_final(ni,
                                    scan.htcap, scan.htinfo))
                                        ht_state_change = 1;
                        }
 
                        /* XXX same for VHT? */
#endif
                        if (ni != NULL) {
                                IEEE80211_RSSI_LPF(ni->ni_avgrssi, rssi);
                                ni->ni_noise = nf;
                        }
                        /*
                         * Same here - the channel width change should
                         * be applied to the specific peer node, not
                         * to the ic.  Ie, the interface configuration
                         * should stay in its current channel width;
                         * but it should change the rate control and
                         * any queued frames for the given node only.
                         *
                         * Since there's no (current) way to inform
                         * the driver that a channel width change has
                         * occurred for a single node, just stub this
                         * out.
                         */
#if 0
                        if (ht_state_change)
                                ieee80211_update_chw(ic);
#endif
                }
                break;
        }
 
        case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
                if (vap->iv_state != IEEE80211_S_RUN) {
                        IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
                            wh, NULL, "wrong state %s",
                            ieee80211_state_name[vap->iv_state]);
                        vap->iv_stats.is_rx_mgtdiscard++;
                        return;
                }
                if (IEEE80211_IS_MULTICAST(wh->i_addr2)) {
                        /* frame must be directed */
                        IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
                            wh, NULL, "%s", "not unicast");
                        vap->iv_stats.is_rx_mgtdiscard++;       /* XXX stat */
                        return;
                }
 
                /*
                 * prreq frame format
                 *      [tlv] ssid
                 *      [tlv] supported rates
                 *      [tlv] extended supported rates
                 */
                ssid = rates = xrates = NULL;
                while (efrm - frm > 1) {
                        IEEE80211_VERIFY_LENGTH(efrm - frm, frm[1] + 2, return);
                        switch (*frm) {
                        case IEEE80211_ELEMID_SSID:
                                ssid = frm;
                                break;
                        case IEEE80211_ELEMID_RATES:
                                rates = frm;
                                break;
                        case IEEE80211_ELEMID_XRATES:
                                xrates = frm;
                                break;
                        }
                        frm += frm[1] + 2;
                }
                IEEE80211_VERIFY_ELEMENT(rates, IEEE80211_RATE_MAXSIZE, return);
                if (xrates != NULL)
                        IEEE80211_VERIFY_ELEMENT(xrates,
                                IEEE80211_RATE_MAXSIZE - rates[1], return);
                IEEE80211_VERIFY_ELEMENT(ssid, IEEE80211_NWID_LEN, return);
                IEEE80211_VERIFY_SSID(vap->iv_bss, ssid, return);
                if ((vap->iv_flags & IEEE80211_F_HIDESSID) && ssid[1] == 0) {
                        IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
                            wh, NULL,
                            "%s", "no ssid with ssid suppression enabled");
                        vap->iv_stats.is_rx_ssidmismatch++; /*XXX*/
                        return;
                }
 
                /* XXX find a better class or define it's own */
                IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_INPUT, wh->i_addr2,
                    "%s", "recv probe req");
                /*
                 * Some legacy 11b clients cannot hack a complete
                 * probe response frame.  When the request includes
                 * only a bare-bones rate set, communicate this to
                 * the transmit side.
                 */
                ieee80211_send_proberesp(vap, wh->i_addr2,
                    is11bclient(rates, xrates) ? IEEE80211_SEND_LEGACY_11B : 0);
 
                /*
                 * Note: we don't benefit from stashing the probe request
                 * IEs away to use for IBSS negotiation, because we
                 * typically don't get all of the IEs.
                 */
                break;
 
        case IEEE80211_FC0_SUBTYPE_ACTION:
        case IEEE80211_FC0_SUBTYPE_ACTION_NOACK:
                if ((ni == vap->iv_bss) &&
                    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
                        IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
                            wh, NULL, "%s", "unknown node");
                        vap->iv_stats.is_rx_mgtdiscard++;
                } else if (!IEEE80211_ADDR_EQ(vap->iv_myaddr, wh->i_addr1) &&
                    !IEEE80211_IS_MULTICAST(wh->i_addr1)) {
                        IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT | IEEE80211_MSG_DEBUG,
                            wh, NULL, "%s", "not for us");
                        vap->iv_stats.is_rx_mgtdiscard++;
                } else if (vap->iv_state != IEEE80211_S_RUN) {
                        IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT | IEEE80211_MSG_DEBUG,
                            wh, NULL, "wrong state %s",
                            ieee80211_state_name[vap->iv_state]);
                        vap->iv_stats.is_rx_mgtdiscard++;
                } else {
                        if (ieee80211_parse_action(ni, m0) == 0)
                                (void)ic->ic_recv_action(ni, wh, frm, efrm);
                }
                break;
 
        case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
        case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
        case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
        case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
        case IEEE80211_FC0_SUBTYPE_TIMING_ADV:
        case IEEE80211_FC0_SUBTYPE_ATIM:
        case IEEE80211_FC0_SUBTYPE_DISASSOC:
        case IEEE80211_FC0_SUBTYPE_AUTH:
        case IEEE80211_FC0_SUBTYPE_DEAUTH:
                IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
                    wh, NULL, "%s", "not handled");
                vap->iv_stats.is_rx_mgtdiscard++;
                break;
 
        default:
                IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
                    wh, "mgt", "subtype 0x%x not handled", subtype);
                vap->iv_stats.is_rx_badsubtype++;
                break;
        }
}
#undef IEEE80211_VERIFY_LENGTH
#undef IEEE80211_VERIFY_ELEMENT
 
static void
ahdemo_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
        int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf)
{
        struct ieee80211vap *vap = ni->ni_vap;
        struct ieee80211com *ic = ni->ni_ic;
 
        /*
         * Process management frames when scanning; useful for doing
         * a site-survey.
         */
        if (ic->ic_flags & IEEE80211_F_SCAN)
                adhoc_recv_mgmt(ni, m0, subtype, rxs, rssi, nf);
        else {
#ifdef IEEE80211_DEBUG
                struct ieee80211_frame *wh;
 
                wh = mtod(m0, struct ieee80211_frame *);
#endif
                switch (subtype) {
                case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
                case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
                case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
                case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
                case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
                case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
                case IEEE80211_FC0_SUBTYPE_TIMING_ADV:
                case IEEE80211_FC0_SUBTYPE_BEACON:
                case IEEE80211_FC0_SUBTYPE_ATIM:
                case IEEE80211_FC0_SUBTYPE_DISASSOC:
                case IEEE80211_FC0_SUBTYPE_AUTH:
                case IEEE80211_FC0_SUBTYPE_DEAUTH:
                case IEEE80211_FC0_SUBTYPE_ACTION:
                case IEEE80211_FC0_SUBTYPE_ACTION_NOACK:
                        IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
                             wh, NULL, "%s", "not handled");
                        vap->iv_stats.is_rx_mgtdiscard++;
                        break;
                default:
                        IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
                             wh, "mgt", "subtype 0x%x not handled", subtype);
                        vap->iv_stats.is_rx_badsubtype++;
                        break;
                }
        }
}
 
static void
adhoc_recv_ctl(struct ieee80211_node *ni, struct mbuf *m, int subtype)
{
 
        switch (subtype) {
        case IEEE80211_FC0_SUBTYPE_BAR:
                ieee80211_recv_bar(ni, m);
                break;
        }
}