ieee80211_input.c

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/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2001 Atsushi Onoe
 * Copyright (c) 2002-2009 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>
__FBSDID("$FreeBSD$");
 
#include "opt_wlan.h"
 
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>   
#include <sys/malloc.h>
#include <sys/endian.h>
#include <sys/kernel.h>
 
#include <sys/socket.h>
 
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_llc.h>
#include <net/if_media.h>
#include <net/if_vlan_var.h>
 
#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_input.h>
#ifdef IEEE80211_SUPPORT_MESH
#include <net80211/ieee80211_mesh.h>
#endif
 
#include <net/bpf.h>
 
#ifdef INET
#include <netinet/in.h>
#include <net/ethernet.h>
#endif
 
static void
ieee80211_process_mimo(struct ieee80211_node *ni, struct ieee80211_rx_stats *rx)
{
        int i;
 
        /* Verify the required MIMO bits are set */
        if ((rx->r_flags & (IEEE80211_R_C_CHAIN | IEEE80211_R_C_NF | IEEE80211_R_C_RSSI)) !=
            (IEEE80211_R_C_CHAIN | IEEE80211_R_C_NF | IEEE80211_R_C_RSSI))
                return;
 
        /* XXX This assumes the MIMO radios have both ctl and ext chains */
        for (i = 0; i < MIN(rx->c_chain, IEEE80211_MAX_CHAINS); i++) {
                IEEE80211_RSSI_LPF(ni->ni_mimo_rssi_ctl[i], rx->c_rssi_ctl[i]);
                IEEE80211_RSSI_LPF(ni->ni_mimo_rssi_ext[i], rx->c_rssi_ext[i]);
        }
 
        /* XXX This also assumes the MIMO radios have both ctl and ext chains */
        for(i = 0; i < MIN(rx->c_chain, IEEE80211_MAX_CHAINS); i++) {
                ni->ni_mimo_noise_ctl[i] = rx->c_nf_ctl[i];
                ni->ni_mimo_noise_ext[i] = rx->c_nf_ext[i];
        }
        ni->ni_mimo_chains = rx->c_chain;
}
 
int
ieee80211_input_mimo(struct ieee80211_node *ni, struct mbuf *m)
{
        struct ieee80211_rx_stats rxs;
 
        /* try to read stats from mbuf */
        bzero(&rxs, sizeof(rxs));
        if (ieee80211_get_rx_params(m, &rxs) != 0)
                return (-1);
 
        /* XXX should assert IEEE80211_R_NF and IEEE80211_R_RSSI are set */
        ieee80211_process_mimo(ni, &rxs);
 
        //return ieee80211_input(ni, m, rx->rssi, rx->nf);
        return ni->ni_vap->iv_input(ni, m, &rxs, rxs.c_rssi, rxs.c_nf);
}
 
int
ieee80211_input_all(struct ieee80211com *ic, struct mbuf *m, int rssi, int nf)
{
        struct ieee80211_rx_stats rx;
 
        rx.r_flags = IEEE80211_R_NF | IEEE80211_R_RSSI;
        rx.c_nf = nf;
        rx.c_rssi = rssi;
 
        if (!ieee80211_add_rx_params(m, &rx))
                return (-1);
 
        return ieee80211_input_mimo_all(ic, m);
}
 
int
ieee80211_input_mimo_all(struct ieee80211com *ic, struct mbuf *m)
{
        struct ieee80211vap *vap;
        int type = -1;
 
        m->m_flags |= M_BCAST;          /* NB: mark for bpf tap'ing */
 
        /* XXX locking */
        TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
                struct ieee80211_node *ni;
                struct mbuf *mcopy;
 
                /* NB: could check for IFF_UP but this is cheaper */
                if (vap->iv_state == IEEE80211_S_INIT)
                        continue;
                /*
                 * WDS vap's only receive directed traffic from the
                 * station at the ``far end''.  That traffic should
                 * be passed through the AP vap the station is associated
                 * to--so don't spam them with mcast frames.
                 */
                if (vap->iv_opmode == IEEE80211_M_WDS)
                        continue;
                if (TAILQ_NEXT(vap, iv_next) != NULL) {
                        /*
                         * Packet contents are changed by ieee80211_decap
                         * so do a deep copy of the packet.
                         * NB: tags are copied too.
                         */
                        mcopy = m_dup(m, M_NOWAIT);
                        if (mcopy == NULL) {
                                /* XXX stat+msg */
                                continue;
                        }
                } else {
                        mcopy = m;
                        m = NULL;
                }
                ni = ieee80211_ref_node(vap->iv_bss);
                type = ieee80211_input_mimo(ni, mcopy);
                ieee80211_free_node(ni);
        }
        if (m != NULL)                  /* no vaps, reclaim mbuf */
                m_freem(m);
        return type;
}
 
/*
 * This function reassembles fragments.
 *
 * XXX should handle 3 concurrent reassemblies per-spec.
 */
struct mbuf *
ieee80211_defrag(struct ieee80211_node *ni, struct mbuf *m, int hdrspace,
        int has_decrypted)
{
        struct ieee80211vap *vap = ni->ni_vap;
        struct ieee80211_frame *wh = mtod(m, struct ieee80211_frame *);
        struct ieee80211_frame *lwh;
        uint16_t rxseq;
        uint8_t fragno;
        uint8_t more_frag = wh->i_fc[1] & IEEE80211_FC1_MORE_FRAG;
        struct mbuf *mfrag;
 
        KASSERT(!IEEE80211_IS_MULTICAST(wh->i_addr1), ("multicast fragm?"));
 
        rxseq = le16toh(*(uint16_t *)wh->i_seq);
        fragno = rxseq & IEEE80211_SEQ_FRAG_MASK;
 
        /* Quick way out, if there's nothing to defragment */
        if (!more_frag && fragno == 0 && ni->ni_rxfrag[0] == NULL)
                return m;
 
        /* Temporarily set flag to remember if fragment was encrypted. */
        /* XXX use a non-packet altering storage for this in the future. */
        if (has_decrypted)
                wh->i_fc[1] |= IEEE80211_FC1_PROTECTED;
 
        /*
         * Remove frag to insure it doesn't get reaped by timer.
         */
        if (ni->ni_table == NULL) {
                /*
                 * Should never happen.  If the node is orphaned (not in
                 * the table) then input packets should not reach here.
                 * Otherwise, a concurrent request that yanks the table
                 * should be blocked by other interlocking and/or by first
                 * shutting the driver down.  Regardless, be defensive
                 * here and just bail
                 */
                /* XXX need msg+stat */
                m_freem(m);
                return NULL;
        }
        IEEE80211_NODE_LOCK(ni->ni_table);
        mfrag = ni->ni_rxfrag[0];
        ni->ni_rxfrag[0] = NULL;
        IEEE80211_NODE_UNLOCK(ni->ni_table);
 
        /*
         * Validate new fragment is in order and
         * related to the previous ones.
         */
        if (mfrag != NULL) {
                uint16_t last_rxseq;
 
                lwh = mtod(mfrag, struct ieee80211_frame *);
                last_rxseq = le16toh(*(uint16_t *)lwh->i_seq);
                /*
                 * NB: check seq # and frag together. Also check that both
                 * fragments are plaintext or that both are encrypted.
                 */
                if (rxseq == last_rxseq+1 &&
                    IEEE80211_ADDR_EQ(wh->i_addr1, lwh->i_addr1) &&
                    IEEE80211_ADDR_EQ(wh->i_addr2, lwh->i_addr2) &&
                    !((wh->i_fc[1] ^ lwh->i_fc[1]) & IEEE80211_FC1_PROTECTED)) {
                        /* XXX clear MORE_FRAG bit? */
                        /* track last seqnum and fragno */
                        *(uint16_t *) lwh->i_seq = *(uint16_t *) wh->i_seq;
 
                        m_adj(m, hdrspace);             /* strip header */
                        m_catpkt(mfrag, m);             /* concatenate */
                } else {
                        /*
                         * Unrelated fragment or no space for it,
                         * clear current fragments.
                         */
                        m_freem(mfrag);
                        mfrag = NULL;
                }
        }
 
        if (mfrag == NULL) {
                if (fragno != 0) {              /* !first fragment, discard */
                        vap->iv_stats.is_rx_defrag++;
                        IEEE80211_NODE_STAT(ni, rx_defrag);
                        m_freem(m);
                        return NULL;
                }
                mfrag = m;
        }
        if (more_frag) {                        /* more to come, save */
                ni->ni_rxfragstamp = ticks;
                ni->ni_rxfrag[0] = mfrag;
                mfrag = NULL;
        }
        /* Remember to clear protected flag that was temporarily set. */
        if (mfrag != NULL) {
                wh = mtod(mfrag, struct ieee80211_frame *);
                wh->i_fc[1] &= ~IEEE80211_FC1_PROTECTED;
        }
        return mfrag;
}
 
void
ieee80211_deliver_data(struct ieee80211vap *vap,
        struct ieee80211_node *ni, struct mbuf *m)
{
        struct ether_header *eh = mtod(m, struct ether_header *);
        struct ifnet *ifp = vap->iv_ifp;
 
        /* clear driver/net80211 flags before passing up */
        m->m_flags &= ~(M_MCAST | M_BCAST);
        m_clrprotoflags(m);
 
        /* NB: see hostap_deliver_data, this path doesn't handle hostap */
        KASSERT(vap->iv_opmode != IEEE80211_M_HOSTAP, ("gack, hostap"));
        /*
         * Do accounting.
         */
        if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
        IEEE80211_NODE_STAT(ni, rx_data);
        IEEE80211_NODE_STAT_ADD(ni, rx_bytes, m->m_pkthdr.len);
        if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
                if (ETHER_IS_BROADCAST(eh->ether_dhost))
                        m->m_flags |= M_BCAST;
                else
                        m->m_flags |= M_MCAST;
                IEEE80211_NODE_STAT(ni, rx_mcast);
        } else
                IEEE80211_NODE_STAT(ni, rx_ucast);
        m->m_pkthdr.rcvif = ifp;
 
        if (ni->ni_vlan != 0) {
                /* attach vlan tag */
                m->m_pkthdr.ether_vtag = ni->ni_vlan;
                m->m_flags |= M_VLANTAG;
        }
        ifp->if_input(ifp, m);
}
 
struct mbuf *
ieee80211_decap(struct ieee80211vap *vap, struct mbuf *m, int hdrlen,
        uint8_t qos)
{
        struct ieee80211_qosframe_addr4 wh;
        struct ether_header *eh;
        struct llc *llc;
 
        KASSERT(hdrlen <= sizeof(wh),
            ("hdrlen %d > max %zd", hdrlen, sizeof(wh)));
 
        if (m->m_len < hdrlen + sizeof(*llc) &&
            (m = m_pullup(m, hdrlen + sizeof(*llc))) == NULL) {
                vap->iv_stats.is_rx_tooshort++;
                /* XXX msg */
                return NULL;
        }
        memcpy(&wh, mtod(m, caddr_t), hdrlen);
        llc = (struct llc *)(mtod(m, caddr_t) + hdrlen);
        if (llc->llc_dsap == LLC_SNAP_LSAP && llc->llc_ssap == LLC_SNAP_LSAP &&
            llc->llc_control == LLC_UI && llc->llc_snap.org_code[0] == 0 &&
            llc->llc_snap.org_code[1] == 0 && llc->llc_snap.org_code[2] == 0 &&
            /* NB: preserve AppleTalk frames that have a native SNAP hdr */
            !(llc->llc_snap.ether_type == htons(ETHERTYPE_AARP) ||
              llc->llc_snap.ether_type == htons(ETHERTYPE_IPX)) &&
            /* Do not want to touch A-MSDU frames. */
            !(qos & IEEE80211_QOS_AMSDU)) {
                m_adj(m, hdrlen + sizeof(struct llc) - sizeof(*eh));
                llc = NULL;
        } else {
                m_adj(m, hdrlen - sizeof(*eh));
        }
        eh = mtod(m, struct ether_header *);
        switch (wh.i_fc[1] & IEEE80211_FC1_DIR_MASK) {
        case IEEE80211_FC1_DIR_NODS:
                IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr1);
                IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr2);
                break;
        case IEEE80211_FC1_DIR_TODS:
                IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr3);
                IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr2);
                break;
        case IEEE80211_FC1_DIR_FROMDS:
                IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr1);
                IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr3);
                break;
        case IEEE80211_FC1_DIR_DSTODS:
                IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr3);
                IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr4);
                break;
        }
#ifndef __NO_STRICT_ALIGNMENT
        if (!ALIGNED_POINTER(mtod(m, caddr_t) + sizeof(*eh), uint32_t)) {
                m = ieee80211_realign(vap, m, sizeof(*eh));
                if (m == NULL)
                        return NULL;
        }
#endif /* !__NO_STRICT_ALIGNMENT */
        if (llc != NULL) {
                eh = mtod(m, struct ether_header *);
                eh->ether_type = htons(m->m_pkthdr.len - sizeof(*eh));
        }
        return m;
}
 
/*
 * Decap a frame encapsulated in a fast-frame/A-MSDU.
 */
struct mbuf *
ieee80211_decap1(struct mbuf *m, int *framelen)
{
#define FF_LLC_SIZE     (sizeof(struct ether_header) + sizeof(struct llc))
        struct ether_header *eh;
        struct llc *llc;
        const uint8_t llc_hdr_mac[ETHER_ADDR_LEN] = {
                /* MAC address matching the 802.2 LLC header */
                LLC_SNAP_LSAP, LLC_SNAP_LSAP, LLC_UI, 0, 0, 0
        };
 
        /*
         * The frame has an 802.3 header followed by an 802.2
         * LLC header.  The encapsulated frame length is in the
         * first header type field; save that and overwrite it 
         * with the true type field found in the second.  Then
         * copy the 802.3 header up to where it belongs and
         * adjust the mbuf contents to remove the void.
         */
        if (m->m_len < FF_LLC_SIZE && (m = m_pullup(m, FF_LLC_SIZE)) == NULL)
                return NULL;
        eh = mtod(m, struct ether_header *);    /* 802.3 header is first */
 
        /*
         * Detect possible attack where a single 802.11 frame is processed
         * as an A-MSDU frame due to an adversary setting the A-MSDU present
         * bit in the 802.11 QoS header. [FragAttacks]
         */
        if (memcmp(eh->ether_dhost, llc_hdr_mac, ETHER_ADDR_LEN) == 0)
                return NULL;
 
        llc = (struct llc *)&eh[1];             /* 802.2 header follows */
        *framelen = ntohs(eh->ether_type)       /* encap'd frame size */
                  + sizeof(struct ether_header) - sizeof(struct llc);
        eh->ether_type = llc->llc_un.type_snap.ether_type;
        ovbcopy(eh, mtod(m, uint8_t *) + sizeof(struct llc),
                sizeof(struct ether_header));
        m_adj(m, sizeof(struct llc));
        return m;
#undef FF_LLC_SIZE
}
 
/*
 * Install received rate set information in the node's state block.
 */
int
ieee80211_setup_rates(struct ieee80211_node *ni,
        const uint8_t *rates, const uint8_t *xrates, int flags)
{
        struct ieee80211vap *vap = ni->ni_vap;
        struct ieee80211_rateset *rs = &ni->ni_rates;
 
        memset(rs, 0, sizeof(*rs));
        rs->rs_nrates = rates[1];
        memcpy(rs->rs_rates, rates + 2, rs->rs_nrates);
        if (xrates != NULL) {
                uint8_t nxrates;
                /*
                 * Tack on 11g extended supported rate element.
                 */
                nxrates = xrates[1];
                if (rs->rs_nrates + nxrates > IEEE80211_RATE_MAXSIZE) {
                        nxrates = IEEE80211_RATE_MAXSIZE - rs->rs_nrates;
                        IEEE80211_NOTE(vap, IEEE80211_MSG_XRATE, ni,
                            "extended rate set too large; only using "
                            "%u of %u rates", nxrates, xrates[1]);
                        vap->iv_stats.is_rx_rstoobig++;
                }
                memcpy(rs->rs_rates + rs->rs_nrates, xrates+2, nxrates);
                rs->rs_nrates += nxrates;
        }
        return ieee80211_fix_rate(ni, rs, flags);
}
 
/*
 * Send a management frame error response to the specified
 * station.  If ni is associated with the station then use
 * it; otherwise allocate a temporary node suitable for
 * transmitting the frame and then free the reference so
 * it will go away as soon as the frame has been transmitted.
 */
void
ieee80211_send_error(struct ieee80211_node *ni,
        const uint8_t mac[IEEE80211_ADDR_LEN], int subtype, int arg)
{
        struct ieee80211vap *vap = ni->ni_vap;
        int istmp;
 
        if (ni == vap->iv_bss) {
                if (vap->iv_state != IEEE80211_S_RUN) {
                        /*
                         * XXX hack until we get rid of this routine.
                         * We can be called prior to the vap reaching
                         * run state under certain conditions in which
                         * case iv_bss->ni_chan will not be setup.
                         * Check for this explicitly and and just ignore
                         * the request.
                         */
                        return;
                }
                ni = ieee80211_tmp_node(vap, mac);
                if (ni == NULL) {
                        /* XXX msg */
                        return;
                }
                istmp = 1;
        } else
                istmp = 0;
        IEEE80211_SEND_MGMT(ni, subtype, arg);
        if (istmp)
                ieee80211_free_node(ni);
}
 
int
ieee80211_alloc_challenge(struct ieee80211_node *ni)
{
        if (ni->ni_challenge == NULL)
                ni->ni_challenge = (uint32_t *)
                    IEEE80211_MALLOC(IEEE80211_CHALLENGE_LEN,
                      M_80211_NODE, IEEE80211_M_NOWAIT);
        if (ni->ni_challenge == NULL) {
                IEEE80211_NOTE(ni->ni_vap,
                    IEEE80211_MSG_DEBUG | IEEE80211_MSG_AUTH, ni,
                    "%s", "shared key challenge alloc failed");
                /* XXX statistic */
        }
        return (ni->ni_challenge != NULL);
}
 
/*
 * Parse a Beacon or ProbeResponse frame and return the
 * useful information in an ieee80211_scanparams structure.
 * Status is set to 0 if no problems were found; otherwise
 * a bitmask of IEEE80211_BPARSE_* items is returned that
 * describes the problems detected.
 */
int
ieee80211_parse_beacon(struct ieee80211_node *ni, struct mbuf *m,
        struct ieee80211_channel *rxchan, struct ieee80211_scanparams *scan)
{
        struct ieee80211vap *vap = ni->ni_vap;
        struct ieee80211com *ic = ni->ni_ic;
        struct ieee80211_frame *wh;
        uint8_t *frm, *efrm;
 
        wh = mtod(m, struct ieee80211_frame *);
        frm = (uint8_t *)&wh[1];
        efrm = mtod(m, uint8_t *) + m->m_len;
        scan->status = 0;
        /*
         * beacon/probe response frame format
         *
         * XXX Update from 802.11-2012 - eg where HT is
         *      [8] time stamp
         *      [2] beacon interval
         *      [2] capability information
         *      [tlv] ssid
         *      [tlv] supported rates
         *      [tlv] country information
         *      [tlv] channel switch announcement (CSA)
         *      [tlv] parameter set (FH/DS)
         *      [tlv] erp information
         *      [tlv] extended supported rates
         *      [tlv] WME
         *      [tlv] WPA or RSN
         *      [tlv] HT capabilities
         *      [tlv] HT information
         *      [tlv] VHT capabilities
         *      [tlv] VHT information
         *      [tlv] Atheros capabilities
         *      [tlv] Mesh ID
         *      [tlv] Mesh Configuration
         */
        IEEE80211_VERIFY_LENGTH(efrm - frm, 12,
            return (scan->status = IEEE80211_BPARSE_BADIELEN));
        memset(scan, 0, sizeof(*scan));
        scan->tstamp  = frm;                            frm += 8;
        scan->bintval = le16toh(*(uint16_t *)frm);      frm += 2;
        scan->capinfo = le16toh(*(uint16_t *)frm);      frm += 2;
        scan->bchan = ieee80211_chan2ieee(ic, rxchan);
        scan->chan = scan->bchan;
        scan->ies = frm;
        scan->ies_len = efrm - frm;
 
        while (efrm - frm > 1) {
                IEEE80211_VERIFY_LENGTH(efrm - frm, frm[1] + 2,
                    return (scan->status = IEEE80211_BPARSE_BADIELEN));
                switch (*frm) {
                case IEEE80211_ELEMID_SSID:
                        scan->ssid = frm;
                        break;
                case IEEE80211_ELEMID_RATES:
                        scan->rates = frm;
                        break;
                case IEEE80211_ELEMID_COUNTRY:
                        scan->country = frm;
                        break;
                case IEEE80211_ELEMID_CSA:
                        scan->csa = frm;
                        break;
                case IEEE80211_ELEMID_QUIET:
                        scan->quiet = frm;
                        break;
                case IEEE80211_ELEMID_FHPARMS:
                        if (ic->ic_phytype == IEEE80211_T_FH) {
                                scan->fhdwell = le16dec(&frm[2]);
                                scan->chan = IEEE80211_FH_CHAN(frm[4], frm[5]);
                                scan->fhindex = frm[6];
                        }
                        break;
                case IEEE80211_ELEMID_DSPARMS:
                        /*
                         * XXX hack this since depending on phytype
                         * is problematic for multi-mode devices.
                         */
                        if (ic->ic_phytype != IEEE80211_T_FH)
                                scan->chan = frm[2];
                        break;
                case IEEE80211_ELEMID_TIM:
                        /* XXX ATIM? */
                        scan->tim = frm;
                        scan->timoff = frm - mtod(m, uint8_t *);
                        break;
                case IEEE80211_ELEMID_IBSSPARMS:
                case IEEE80211_ELEMID_CFPARMS:
                case IEEE80211_ELEMID_PWRCNSTR:
                case IEEE80211_ELEMID_BSSLOAD:
                case IEEE80211_ELEMID_APCHANREP:
                        /* NB: avoid debugging complaints */
                        break;
                case IEEE80211_ELEMID_XRATES:
                        scan->xrates = frm;
                        break;
                case IEEE80211_ELEMID_ERP:
                        if (frm[1] != 1) {
                                IEEE80211_DISCARD_IE(vap,
                                    IEEE80211_MSG_ELEMID, wh, "ERP",
                                    "bad len %u", frm[1]);
                                vap->iv_stats.is_rx_elem_toobig++;
                                break;
                        }
                        scan->erp = frm[2] | 0x100;
                        break;
                case IEEE80211_ELEMID_HTCAP:
                        scan->htcap = frm;
                        break;
                case IEEE80211_ELEMID_VHT_CAP:
                        scan->vhtcap = frm;
                        break;
                case IEEE80211_ELEMID_VHT_OPMODE:
                        scan->vhtopmode = frm;
                        break;
                case IEEE80211_ELEMID_RSN:
                        scan->rsn = frm;
                        break;
                case IEEE80211_ELEMID_HTINFO:
                        scan->htinfo = frm;
                        break;
#ifdef IEEE80211_SUPPORT_MESH
                case IEEE80211_ELEMID_MESHID:
                        scan->meshid = frm;
                        break;
                case IEEE80211_ELEMID_MESHCONF:
                        scan->meshconf = frm;
                        break;
#endif
                /* Extended capabilities; nothing handles it for now */
                case IEEE80211_ELEMID_EXTCAP:
                        break;
                case IEEE80211_ELEMID_VENDOR:
                        if (iswpaoui(frm))
                                scan->wpa = frm;
                        else if (iswmeparam(frm) || iswmeinfo(frm))
                                scan->wme = frm;
#ifdef IEEE80211_SUPPORT_SUPERG
                        else if (isatherosoui(frm))
                                scan->ath = frm;
#endif
#ifdef IEEE80211_SUPPORT_TDMA
                        else if (istdmaoui(frm))
                                scan->tdma = frm;
#endif
                        else if (vap->iv_flags_ht & IEEE80211_FHT_HTCOMPAT) {
                                /*
                                 * Accept pre-draft HT ie's if the
                                 * standard ones have not been seen.
                                 */
                                if (ishtcapoui(frm)) {
                                        if (scan->htcap == NULL)
                                                scan->htcap = frm;
                                } else if (ishtinfooui(frm)) {
                                        if (scan->htinfo == NULL)
                                                scan->htcap = frm;
                                }
                        }
                        break;
                default:
                        IEEE80211_DISCARD_IE(vap, IEEE80211_MSG_ELEMID,
                            wh, "unhandled",
                            "id %u, len %u", *frm, frm[1]);
                        vap->iv_stats.is_rx_elem_unknown++;
                        break;
                }
                frm += frm[1] + 2;
        }
        IEEE80211_VERIFY_ELEMENT(scan->rates, IEEE80211_RATE_MAXSIZE,
            scan->status |= IEEE80211_BPARSE_RATES_INVALID);
        if (scan->rates != NULL && scan->xrates != NULL) {
                /*
                 * NB: don't process XRATES if RATES is missing.  This
                 * avoids a potential null ptr deref and should be ok
                 * as the return code will already note RATES is missing
                 * (so callers shouldn't otherwise process the frame).
                 */
                IEEE80211_VERIFY_ELEMENT(scan->xrates,
                    IEEE80211_RATE_MAXSIZE - scan->rates[1],
                    scan->status |= IEEE80211_BPARSE_XRATES_INVALID);
        }
        IEEE80211_VERIFY_ELEMENT(scan->ssid, IEEE80211_NWID_LEN,
            scan->status |= IEEE80211_BPARSE_SSID_INVALID);
        if (scan->chan != scan->bchan && ic->ic_phytype != IEEE80211_T_FH) {
                /*
                 * Frame was received on a channel different from the
                 * one indicated in the DS params element id;
                 * silently discard it.
                 *
                 * NB: this can happen due to signal leakage.
                 *     But we should take it for FH phy because
                 *     the rssi value should be correct even for
                 *     different hop pattern in FH.
                 */
                IEEE80211_DISCARD(vap,
                    IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
                    wh, NULL, "for off-channel %u (bchan=%u)",
                    scan->chan, scan->bchan);
                vap->iv_stats.is_rx_chanmismatch++;
                scan->status |= IEEE80211_BPARSE_OFFCHAN;
        }
        if (!(IEEE80211_BINTVAL_MIN <= scan->bintval &&
              scan->bintval <= IEEE80211_BINTVAL_MAX)) {
                IEEE80211_DISCARD(vap,
                    IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
                    wh, NULL, "bogus beacon interval (%d TU)",
                    (int) scan->bintval);
                vap->iv_stats.is_rx_badbintval++;
                scan->status |= IEEE80211_BPARSE_BINTVAL_INVALID;
        }
        if (scan->country != NULL) {
                /*
                 * Validate we have at least enough data to extract
                 * the country code.  Not sure if we should return an
                 * error instead of discarding the IE; consider this
                 * being lenient as we don't depend on the data for
                 * correct operation.
                 */
                IEEE80211_VERIFY_LENGTH(scan->country[1], 3 * sizeof(uint8_t),
                    scan->country = NULL);
        }
        if (scan->csa != NULL) {
                /*
                 * Validate Channel Switch Announcement; this must
                 * be the correct length or we toss the frame.
                 */
                IEEE80211_VERIFY_LENGTH(scan->csa[1], 3 * sizeof(uint8_t),
                    scan->status |= IEEE80211_BPARSE_CSA_INVALID);
        }
        /*
         * Process HT ie's.  This is complicated by our
         * accepting both the standard ie's and the pre-draft
         * vendor OUI ie's that some vendors still use/require.
         */
        if (scan->htcap != NULL) {
                IEEE80211_VERIFY_LENGTH(scan->htcap[1],
                     scan->htcap[0] == IEEE80211_ELEMID_VENDOR ?
                         4 + sizeof(struct ieee80211_ie_htcap)-2 :
                         sizeof(struct ieee80211_ie_htcap)-2,
                     scan->htcap = NULL);
        }
        if (scan->htinfo != NULL) {
                IEEE80211_VERIFY_LENGTH(scan->htinfo[1],
                     scan->htinfo[0] == IEEE80211_ELEMID_VENDOR ?
                         4 + sizeof(struct ieee80211_ie_htinfo)-2 :
                         sizeof(struct ieee80211_ie_htinfo)-2,
                     scan->htinfo = NULL);
        }
 
        /* Process VHT IEs */
        if (scan->vhtcap != NULL) {
                IEEE80211_VERIFY_LENGTH(scan->vhtcap[1],
                    sizeof(struct ieee80211_ie_vhtcap) - 2,
                    scan->vhtcap = NULL);
        }
        if (scan->vhtopmode != NULL) {
                IEEE80211_VERIFY_LENGTH(scan->vhtopmode[1],
                    sizeof(struct ieee80211_ie_vht_operation) - 2,
                    scan->vhtopmode = NULL);
        }
 
        return scan->status;
}
 
/*
 * Parse an Action frame.  Return 0 on success, non-zero on failure.
 */
int
ieee80211_parse_action(struct ieee80211_node *ni, struct mbuf *m)
{
        struct ieee80211vap *vap = ni->ni_vap;
        const struct ieee80211_action *ia;
        struct ieee80211_frame *wh;
        uint8_t *frm, *efrm;
 
        /*
         * action frame format:
         *      [1] category
         *      [1] action
         *      [tlv] parameters
         */
        wh = mtod(m, struct ieee80211_frame *);
        frm = (u_int8_t *)&wh[1];
        efrm = mtod(m, u_int8_t *) + m->m_len;
        IEEE80211_VERIFY_LENGTH(efrm - frm,
                sizeof(struct ieee80211_action), return EINVAL);
        ia = (const struct ieee80211_action *) frm;
 
        vap->iv_stats.is_rx_action++;
        IEEE80211_NODE_STAT(ni, rx_action);
 
        /* verify frame payloads but defer processing */
        switch (ia->ia_category) {
        case IEEE80211_ACTION_CAT_BA:
                switch (ia->ia_action) {
                case IEEE80211_ACTION_BA_ADDBA_REQUEST:
                        IEEE80211_VERIFY_LENGTH(efrm - frm,
                            sizeof(struct ieee80211_action_ba_addbarequest),
                            return EINVAL);
                        break;
                case IEEE80211_ACTION_BA_ADDBA_RESPONSE:
                        IEEE80211_VERIFY_LENGTH(efrm - frm,
                            sizeof(struct ieee80211_action_ba_addbaresponse),
                            return EINVAL);
                        break;
                case IEEE80211_ACTION_BA_DELBA:
                        IEEE80211_VERIFY_LENGTH(efrm - frm,
                            sizeof(struct ieee80211_action_ba_delba),
                            return EINVAL);
                        break;
                }
                break;
        case IEEE80211_ACTION_CAT_HT:
                switch (ia->ia_action) {
                case IEEE80211_ACTION_HT_TXCHWIDTH:
                        IEEE80211_VERIFY_LENGTH(efrm - frm,
                            sizeof(struct ieee80211_action_ht_txchwidth),
                            return EINVAL);
                        break;
                case IEEE80211_ACTION_HT_MIMOPWRSAVE:
                        IEEE80211_VERIFY_LENGTH(efrm - frm,
                            sizeof(struct ieee80211_action_ht_mimopowersave),
                            return EINVAL);
                        break;
                }
                break;
#ifdef IEEE80211_SUPPORT_MESH
        case IEEE80211_ACTION_CAT_MESH:
                switch (ia->ia_action) {
                case IEEE80211_ACTION_MESH_LMETRIC:
                        /*
                         * XXX: verification is true only if we are using
                         * Airtime link metric (default)
                         */
                        IEEE80211_VERIFY_LENGTH(efrm - frm,
                            sizeof(struct ieee80211_meshlmetric_ie),
                            return EINVAL);
                        break;
                case IEEE80211_ACTION_MESH_HWMP:
                        /* verify something */
                        break;
                case IEEE80211_ACTION_MESH_GANN:
                        IEEE80211_VERIFY_LENGTH(efrm - frm,
                            sizeof(struct ieee80211_meshgann_ie),
                            return EINVAL);
                        break;
                case IEEE80211_ACTION_MESH_CC:
                case IEEE80211_ACTION_MESH_MCCA_SREQ:
                case IEEE80211_ACTION_MESH_MCCA_SREP:
                case IEEE80211_ACTION_MESH_MCCA_AREQ:
                case IEEE80211_ACTION_MESH_MCCA_ADVER:
                case IEEE80211_ACTION_MESH_MCCA_TRDOWN:
                case IEEE80211_ACTION_MESH_TBTT_REQ:
                case IEEE80211_ACTION_MESH_TBTT_RES:
                        /* reject these early on, not implemented */
                        IEEE80211_DISCARD(vap,
                            IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
                            wh, NULL, "not implemented yet, act=0x%02X",
                            ia->ia_action);
                        return EINVAL;
                }
                break;
        case IEEE80211_ACTION_CAT_SELF_PROT:
                /* If TA or RA group address discard silently */
                if (IEEE80211_IS_MULTICAST(wh->i_addr1) ||
                        IEEE80211_IS_MULTICAST(wh->i_addr2))
                        return EINVAL;
                /*
                 * XXX: Should we verify complete length now or it is
                 * to varying in sizes?
                 */
                switch (ia->ia_action) {
                case IEEE80211_ACTION_MESHPEERING_CONFIRM:
                case IEEE80211_ACTION_MESHPEERING_CLOSE:
                        /* is not a peering candidate (yet) */
                        if (ni == vap->iv_bss)
                                return EINVAL;
                        break;
                }
                break;
#endif
        case IEEE80211_ACTION_CAT_VHT:
                printf("%s: TODO: VHT handling!\n", __func__);
                break;
        }
        return 0;
}
 
#ifdef IEEE80211_DEBUG
/*
 * Debugging support.
 */
void
ieee80211_ssid_mismatch(struct ieee80211vap *vap, const char *tag,
        uint8_t mac[IEEE80211_ADDR_LEN], uint8_t *ssid)
{
        printf("[%s] discard %s frame, ssid mismatch: ",
                ether_sprintf(mac), tag);
        ieee80211_print_essid(ssid + 2, ssid[1]);
        printf("\n");
}
 
/*
 * Return the bssid of a frame.
 */
static const uint8_t *
ieee80211_getbssid(const struct ieee80211vap *vap,
        const struct ieee80211_frame *wh)
{
        if (vap->iv_opmode == IEEE80211_M_STA)
                return wh->i_addr2;
        if ((wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) != IEEE80211_FC1_DIR_NODS)
                return wh->i_addr1;
        if ((wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) == IEEE80211_FC0_SUBTYPE_PS_POLL)
                return wh->i_addr1;
        return wh->i_addr3;
}
 
#include <machine/stdarg.h>
 
void
ieee80211_note(const struct ieee80211vap *vap, const char *fmt, ...)
{
        char buf[256];          /* XXX */
        va_list ap;
        int len;
 
        va_start(ap, fmt);
        len = vsnprintf(buf, sizeof(buf), fmt, ap);
        va_end(ap);
 
        if_printf(vap->iv_ifp, "%s", buf);      /* NB: no \n */
 
        if (len >= sizeof(buf))
                printf("%s: XXX buffer too small: len = %d\n", __func__, len);
}
 
void
ieee80211_note_frame(const struct ieee80211vap *vap,
        const struct ieee80211_frame *wh,
        const char *fmt, ...)
{
        char buf[256];          /* XXX */
        va_list ap;
        int len;
 
        va_start(ap, fmt);
        len = vsnprintf(buf, sizeof(buf), fmt, ap);
        va_end(ap);
        if_printf(vap->iv_ifp, "[%s] %s\n",
                ether_sprintf(ieee80211_getbssid(vap, wh)), buf);
 
        if (len >= sizeof(buf))
                printf("%s: XXX buffer too small: len = %d\n", __func__, len);
}
 
void
ieee80211_note_mac(const struct ieee80211vap *vap,
        const uint8_t mac[IEEE80211_ADDR_LEN],
        const char *fmt, ...)
{
        char buf[256];          /* XXX */
        va_list ap;
        int len;
 
        va_start(ap, fmt);
        len = vsnprintf(buf, sizeof(buf), fmt, ap);
        va_end(ap);
        if_printf(vap->iv_ifp, "[%s] %s\n", ether_sprintf(mac), buf);
 
        if (len >= sizeof(buf))
                printf("%s: XXX buffer too small: len = %d\n", __func__, len);
}
 
void
ieee80211_discard_frame(const struct ieee80211vap *vap,
        const struct ieee80211_frame *wh,
        const char *type, const char *fmt, ...)
{
        char buf[256];          /* XXX */
        va_list ap;
        int len;
 
        va_start(ap, fmt);
        len = vsnprintf(buf, sizeof(buf), fmt, ap);
        va_end(ap);
 
        if_printf(vap->iv_ifp, "[%s] discard %s frame, %s\n",
            ether_sprintf(ieee80211_getbssid(vap, wh)),
            type != NULL ? type : ieee80211_mgt_subtype_name(wh->i_fc[0]),
            buf);
 
        if (len >= sizeof(buf))
                printf("%s: XXX buffer too small: len = %d\n", __func__, len);
}
 
void
ieee80211_discard_ie(const struct ieee80211vap *vap,
        const struct ieee80211_frame *wh,
        const char *type, const char *fmt, ...)
{
        char buf[256];          /* XXX */
        va_list ap;
        int len;
 
        va_start(ap, fmt);
        len = vsnprintf(buf, sizeof(buf), fmt, ap);
        va_end(ap);
 
        if_printf(vap->iv_ifp, "[%s] discard%s%s information element, %s\n",
            ether_sprintf(ieee80211_getbssid(vap, wh)),
            type != NULL ? " " : "", type != NULL ? type : "", buf);
 
        if (len >= sizeof(buf))
                printf("%s: XXX buffer too small: len = %d\n", __func__, len);
}
 
void
ieee80211_discard_mac(const struct ieee80211vap *vap,
        const uint8_t mac[IEEE80211_ADDR_LEN],
        const char *type, const char *fmt, ...)
{
        char buf[256];          /* XXX */
        va_list ap;
        int len;
 
        va_start(ap, fmt);
        len = vsnprintf(buf, sizeof(buf), fmt, ap);
        va_end(ap);
 
        if_printf(vap->iv_ifp, "[%s] discard%s%s frame, %s\n",
            ether_sprintf(mac),
            type != NULL ? " " : "", type != NULL ? type : "", buf);
 
        if (len >= sizeof(buf))
                printf("%s: XXX buffer too small: len = %d\n", __func__, len);
}
#endif /* IEEE80211_DEBUG */