sys/net80211/ieee80211_adhoc.c

   1 /*-
   2  * Copyright (c) 2007-2009 Sam Leffler, Errno Consulting
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include <sys/cdefs.h>
  27 #ifdef __FreeBSD__
  28 __FBSDID("$FreeBSD$");
  29 #endif
  30
  31 /*
  32  * IEEE 802.11 IBSS mode support.
  33  */
  34 #include "opt_inet.h"
  35 #include "opt_wlan.h"
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/mbuf.h>
  40 #include <sys/malloc.h>
  41 #include <sys/kernel.h>
  42
  43 #include <sys/socket.h>
  44 #include <sys/sockio.h>
  45 #include <sys/endian.h>
  46 #include <sys/errno.h>
  47 #include <sys/proc.h>
  48 #include <sys/sysctl.h>
  49
  50 #include <net/if.h>
  51 #include <net/if_media.h>
  52 #include <net/if_llc.h>
  53 #include <net/ethernet.h>
  54
  55 #include <net/bpf.h>
  56
  57 #include <net80211/ieee80211_var.h>
  58 #include <net80211/ieee80211_adhoc.h>
  59 #include <net80211/ieee80211_input.h>
  60 #ifdef IEEE80211_SUPPORT_SUPERG
  61 #include <net80211/ieee80211_superg.h>
  62 #endif
  63 #ifdef IEEE80211_SUPPORT_TDMA
  64 #include <net80211/ieee80211_tdma.h>
  65 #endif
  66
  67 #define IEEE80211_RATE2MBS(r)   (((r) & IEEE80211_RATE_VAL) / 2)
  68
  69 static  void adhoc_vattach(struct ieee80211vap *);
  70 static  int adhoc_newstate(struct ieee80211vap *, enum ieee80211_state, int);
  71 static int adhoc_input(struct ieee80211_node *, struct mbuf *, int, int);
  72 static void adhoc_recv_mgmt(struct ieee80211_node *, struct mbuf *,
  73         int subtype, int, int);
  74 static void ahdemo_recv_mgmt(struct ieee80211_node *, struct mbuf *,
  75         int subtype, int, int);
  76 static void adhoc_recv_ctl(struct ieee80211_node *, struct mbuf *, int subtype);
  77
  78 void
  79 ieee80211_adhoc_attach(struct ieee80211com *ic)
  80 {
  81         ic->ic_vattach[IEEE80211_M_IBSS] = adhoc_vattach;
  82         ic->ic_vattach[IEEE80211_M_AHDEMO] = adhoc_vattach;
  83 }
  84
  85 void
  86 ieee80211_adhoc_detach(struct ieee80211com *ic)
  87 {
  88 }
  89
  90 static void
  91 adhoc_vdetach(struct ieee80211vap *vap)
  92 {
  93 }
  94
  95 static void
  96 adhoc_vattach(struct ieee80211vap *vap)
  97 {
  98         vap->iv_newstate = adhoc_newstate;
  99         vap->iv_input = adhoc_input;
 100         if (vap->iv_opmode == IEEE80211_M_IBSS)
 101                 vap->iv_recv_mgmt = adhoc_recv_mgmt;
 102         else
 103                 vap->iv_recv_mgmt = ahdemo_recv_mgmt;
 104         vap->iv_recv_ctl = adhoc_recv_ctl;
 105         vap->iv_opdetach = adhoc_vdetach;
 106 #ifdef IEEE80211_SUPPORT_TDMA
 107         /*
 108          * Throw control to tdma support.  Note we do this
 109          * after setting up our callbacks so it can piggyback
 110          * on top of us.
 111          */
 112         if (vap->iv_caps & IEEE80211_C_TDMA)
 113                 ieee80211_tdma_vattach(vap);
 114 #endif
 115 }
 116
 117 static void
 118 sta_leave(void *arg, struct ieee80211_node *ni)
 119 {
 120         struct ieee80211vap *vap = arg;
 121
 122         if (ni->ni_vap == vap && ni != vap->iv_bss)
 123                 ieee80211_node_leave(ni);
 124 }
 125
 126 /*
 127  * IEEE80211_M_IBSS+IEEE80211_M_AHDEMO vap state machine handler.
 128  */
 129 static int
 130 adhoc_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
 131 {
 132         struct ieee80211com *ic = vap->iv_ic;
 133         struct ieee80211_node *ni;
 134         enum ieee80211_state ostate;
 135
 136         IEEE80211_LOCK_ASSERT(vap->iv_ic);
 137
 138         ostate = vap->iv_state;
 139         IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
 140             __func__, ieee80211_state_name[ostate],
 141             ieee80211_state_name[nstate], arg);
 142         vap->iv_state = nstate;                 /* state transition */
 143         if (ostate != IEEE80211_S_SCAN)
 144                 ieee80211_cancel_scan(vap);     /* background scan */
 145         ni = vap->iv_bss;                       /* NB: no reference held */
 146         switch (nstate) {
 147         case IEEE80211_S_INIT:
 148                 switch (ostate) {
 149                 case IEEE80211_S_SCAN:
 150                         ieee80211_cancel_scan(vap);
 151                         break;
 152                 default:
 153                         break;
 154                 }
 155                 if (ostate != IEEE80211_S_INIT) {
 156                         /* NB: optimize INIT -> INIT case */
 157                         ieee80211_reset_bss(vap);
 158                 }
 159                 break;
 160         case IEEE80211_S_SCAN:
 161                 switch (ostate) {
 162                 case IEEE80211_S_RUN:           /* beacon miss */
 163                         /* purge station table; entries are stale */
 164                         ieee80211_iterate_nodes(&ic->ic_sta, sta_leave, vap);
 165                         /* fall thru... */
 166                 case IEEE80211_S_INIT:
 167                         if (vap->iv_des_chan != IEEE80211_CHAN_ANYC &&
 168                             !IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
 169                                 /*
 170                                  * Already have a channel; bypass the
 171                                  * scan and startup immediately.
 172                                  */
 173                                 ieee80211_create_ibss(vap, vap->iv_des_chan);
 174                                 break;
 175                         }
 176                         /*
 177                          * Initiate a scan.  We can come here as a result
 178                          * of an IEEE80211_IOC_SCAN_REQ too in which case
 179                          * the vap will be marked with IEEE80211_FEXT_SCANREQ
 180                          * and the scan request parameters will be present
 181                          * in iv_scanreq.  Otherwise we do the default.
 182                          */
 183                         if (vap->iv_flags_ext & IEEE80211_FEXT_SCANREQ) {
 184                                 ieee80211_check_scan(vap,
 185                                     vap->iv_scanreq_flags,
 186                                     vap->iv_scanreq_duration,
 187                                     vap->iv_scanreq_mindwell,
 188                                     vap->iv_scanreq_maxdwell,
 189                                     vap->iv_scanreq_nssid, vap->iv_scanreq_ssid);
 190                                 vap->iv_flags_ext &= ~IEEE80211_FEXT_SCANREQ;
 191                         } else
 192                                 ieee80211_check_scan_current(vap);
 193                         break;
 194                 case IEEE80211_S_SCAN:
 195                         /*
 196                          * This can happen because of a change in state
 197                          * that requires a reset.  Trigger a new scan
 198                          * unless we're in manual roaming mode in which
 199                          * case an application must issue an explicit request.
 200                          */
 201                         if (vap->iv_roaming == IEEE80211_ROAMING_AUTO)
 202                                 ieee80211_check_scan_current(vap);
 203                         break;
 204                 default:
 205                         goto invalid;
 206                 }
 207                 break;
 208         case IEEE80211_S_RUN:
 209                 if (vap->iv_flags & IEEE80211_F_WPA) {
 210                         /* XXX validate prerequisites */
 211                 }
 212                 switch (ostate) {
 213                 case IEEE80211_S_SCAN:
 214 #ifdef IEEE80211_DEBUG
 215                         if (ieee80211_msg_debug(vap)) {
 216                                 ieee80211_note(vap,
 217                                     "synchronized with %s ssid ",
 218                                     ether_sprintf(ni->ni_bssid));
 219                                 ieee80211_print_essid(vap->iv_bss->ni_essid,
 220                                     ni->ni_esslen);
 221                                 /* XXX MCS/HT */
 222                                 printf(" channel %d start %uMb\n",
 223                                     ieee80211_chan2ieee(ic, ic->ic_curchan),
 224                                     IEEE80211_RATE2MBS(ni->ni_txrate));
 225                         }
 226 #endif
 227                         break;
 228                 default:
 229                         goto invalid;
 230                 }
 231                 /*
 232                  * When 802.1x is not in use mark the port authorized
 233                  * at this point so traffic can flow.
 234                  */
 235                 if (ni->ni_authmode != IEEE80211_AUTH_8021X)
 236                         ieee80211_node_authorize(ni);
 237                 /*
 238                  * Fake association when joining an existing bss.
 239                  */
 240                 if (!IEEE80211_ADDR_EQ(ni->ni_macaddr, vap->iv_myaddr) &&
 241                     ic->ic_newassoc != NULL)
 242                         ic->ic_newassoc(ni, ostate != IEEE80211_S_RUN);
 243                 break;
 244         case IEEE80211_S_SLEEP:
 245                 ieee80211_sta_pwrsave(vap, 0);
 246                 break;
 247         default:
 248         invalid:
 249                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE,
 250                     "%s: unexpected state transition %s -> %s\n", __func__,
 251                     ieee80211_state_name[ostate], ieee80211_state_name[nstate]);
 252                 break;
 253         }
 254         return 0;
 255 }
 256
 257 /*
 258  * Decide if a received management frame should be
 259  * printed when debugging is enabled.  This filters some
 260  * of the less interesting frames that come frequently
 261  * (e.g. beacons).
 262  */
 263 static __inline int
 264 doprint(struct ieee80211vap *vap, int subtype)
 265 {
 266         switch (subtype) {
 267         case IEEE80211_FC0_SUBTYPE_BEACON:
 268                 return (vap->iv_ic->ic_flags & IEEE80211_F_SCAN);
 269         case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
 270                 return 1;
 271         }
 272         return 1;
 273 }
 274
 275 /*
 276  * Process a received frame.  The node associated with the sender
 277  * should be supplied.  If nothing was found in the node table then
 278  * the caller is assumed to supply a reference to iv_bss instead.
 279  * The RSSI and a timestamp are also supplied.  The RSSI data is used
 280  * during AP scanning to select a AP to associate with; it can have
 281  * any units so long as values have consistent units and higher values
 282  * mean ``better signal''.  The receive timestamp is currently not used
 283  * by the 802.11 layer.
 284  */
 285 static int
 286 adhoc_input(struct ieee80211_node *ni, struct mbuf *m, int rssi, int nf)
 287 {
 288 #define HAS_SEQ(type)   ((type & 0x4) == 0)
 289         struct ieee80211vap *vap = ni->ni_vap;
 290         struct ieee80211com *ic = ni->ni_ic;
 291         struct ifnet *ifp = vap->iv_ifp;
 292         struct ieee80211_frame *wh;
 293         struct ieee80211_key *key;
 294         struct ether_header *eh;
 295         int hdrspace, need_tap = 1;     /* mbuf need to be tapped. */
 296         uint8_t dir, type, subtype, qos;
 297         uint8_t *bssid;
 298         uint16_t rxseq;
 299
 300         if (m->m_flags & M_AMPDU_MPDU) {
 301                 /*
 302                  * Fastpath for A-MPDU reorder q resubmission.  Frames
 303                  * w/ M_AMPDU_MPDU marked have already passed through
 304                  * here but were received out of order and been held on
 305                  * the reorder queue.  When resubmitted they are marked
 306                  * with the M_AMPDU_MPDU flag and we can bypass most of
 307                  * the normal processing.
 308                  */
 309                 wh = mtod(m, struct ieee80211_frame *);
 310                 type = IEEE80211_FC0_TYPE_DATA;
 311                 dir = wh->i_fc[1] & IEEE80211_FC1_DIR_MASK;
 312                 subtype = IEEE80211_FC0_SUBTYPE_QOS;
 313                 hdrspace = ieee80211_hdrspace(ic, wh);  /* XXX optimize? */
 314                 goto resubmit_ampdu;
 315         }
 316
 317         KASSERT(ni != NULL, ("null node"));
 318         ni->ni_inact = ni->ni_inact_reload;
 319
 320         type = -1;                      /* undefined */
 321
 322         if (m->m_pkthdr.len < sizeof(struct ieee80211_frame_min)) {
 323                 IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
 324                     ni->ni_macaddr, NULL,
 325                     "too short (1): len %u", m->m_pkthdr.len);
 326                 vap->iv_stats.is_rx_tooshort++;
 327                 goto out;
 328         }
 329         /*
 330          * Bit of a cheat here, we use a pointer for a 3-address
 331          * frame format but don't reference fields past outside
 332          * ieee80211_frame_min w/o first validating the data is
 333          * present.
 334          */
 335         wh = mtod(m, struct ieee80211_frame *);
 336
 337         if ((wh->i_fc[0] & IEEE80211_FC0_VERSION_MASK) !=
 338             IEEE80211_FC0_VERSION_0) {
 339                 IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
 340                     ni->ni_macaddr, NULL, "wrong version, fc %02x:%02x",
 341                     wh->i_fc[0], wh->i_fc[1]);
 342                 vap->iv_stats.is_rx_badversion++;
 343                 goto err;
 344         }
 345
 346         dir = wh->i_fc[1] & IEEE80211_FC1_DIR_MASK;
 347         type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
 348         subtype = wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK;
 349         if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
 350                 if (dir != IEEE80211_FC1_DIR_NODS)
 351                         bssid = wh->i_addr1;
 352                 else if (type == IEEE80211_FC0_TYPE_CTL)
 353                         bssid = wh->i_addr1;
 354                 else {
 355                         if (m->m_pkthdr.len < sizeof(struct ieee80211_frame)) {
 356                                 IEEE80211_DISCARD_MAC(vap,
 357                                     IEEE80211_MSG_ANY, ni->ni_macaddr,
 358                                     NULL, "too short (2): len %u",
 359                                     m->m_pkthdr.len);
 360                                 vap->iv_stats.is_rx_tooshort++;
 361                                 goto out;
 362                         }
 363                         bssid = wh->i_addr3;
 364                 }
 365                 /*
 366                  * Validate the bssid.
 367                  */
 368                 if (!IEEE80211_ADDR_EQ(bssid, vap->iv_bss->ni_bssid) &&
 369                     !IEEE80211_ADDR_EQ(bssid, ifp->if_broadcastaddr)) {
 370                         /* not interested in */
 371                         IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
 372                             bssid, NULL, "%s", "not to bss");
 373                         vap->iv_stats.is_rx_wrongbss++;
 374                         goto out;
 375                 }
 376                 /*
 377                  * Data frame, cons up a node when it doesn't
 378                  * exist. This should probably done after an ACL check.
 379                  */
 380                 if (type == IEEE80211_FC0_TYPE_DATA &&
 381                     ni == vap->iv_bss &&
 382                     !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
 383                         /*
 384                          * Beware of frames that come in too early; we
 385                          * can receive broadcast frames and creating sta
 386                          * entries will blow up because there is no bss
 387                          * channel yet.
 388                          */
 389                         if (vap->iv_state != IEEE80211_S_RUN) {
 390                                 IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
 391                                     wh, "data", "not in RUN state (%s)",
 392                                     ieee80211_state_name[vap->iv_state]);
 393                                 vap->iv_stats.is_rx_badstate++;
 394                                 goto err;
 395                         }
 396                         /*
 397                          * Fake up a node for this newly
 398                          * discovered member of the IBSS.
 399                          */
 400                         ni = ieee80211_fakeup_adhoc_node(vap, wh->i_addr2);
 401                         if (ni == NULL) {
 402                                 /* NB: stat kept for alloc failure */
 403                                 goto err;
 404                         }
 405                 }
 406                 IEEE80211_RSSI_LPF(ni->ni_avgrssi, rssi);
 407                 ni->ni_noise = nf;
 408                 if (HAS_SEQ(type)) {
 409                         uint8_t tid = ieee80211_gettid(wh);
 410                         if (IEEE80211_QOS_HAS_SEQ(wh) &&
 411                             TID_TO_WME_AC(tid) >= WME_AC_VI)
 412                                 ic->ic_wme.wme_hipri_traffic++;
 413                         rxseq = le16toh(*(uint16_t *)wh->i_seq);
 414                         if (! ieee80211_check_rxseq(ni, wh)) {
 415                                 /* duplicate, discard */
 416                                 IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
 417                                     bssid, "duplicate",
 418                                     "seqno <%u,%u> fragno <%u,%u> tid %u",
 419                                     rxseq >> IEEE80211_SEQ_SEQ_SHIFT,
 420                                     ni->ni_rxseqs[tid] >>
 421                                         IEEE80211_SEQ_SEQ_SHIFT,
 422                                     rxseq & IEEE80211_SEQ_FRAG_MASK,
 423                                     ni->ni_rxseqs[tid] &
 424                                         IEEE80211_SEQ_FRAG_MASK,
 425                                     tid);
 426                                 vap->iv_stats.is_rx_dup++;
 427                                 IEEE80211_NODE_STAT(ni, rx_dup);
 428                                 goto out;
 429                         }
 430                         ni->ni_rxseqs[tid] = rxseq;
 431                 }
 432         }
 433
 434         switch (type) {
 435         case IEEE80211_FC0_TYPE_DATA:
 436                 hdrspace = ieee80211_hdrspace(ic, wh);
 437                 if (m->m_len < hdrspace &&
 438                     (m = m_pullup(m, hdrspace)) == NULL) {
 439                         IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
 440                             ni->ni_macaddr, NULL,
 441                             "data too short: expecting %u", hdrspace);
 442                         vap->iv_stats.is_rx_tooshort++;
 443                         goto out;               /* XXX */
 444                 }
 445                 if (dir != IEEE80211_FC1_DIR_NODS) {
 446                         IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
 447                             wh, "data", "incorrect dir 0x%x", dir);
 448                         vap->iv_stats.is_rx_wrongdir++;
 449                         goto out;
 450                 }
 451                 /* XXX no power-save support */
 452
 453                 /*
 454                  * Handle A-MPDU re-ordering.  If the frame is to be
 455                  * processed directly then ieee80211_ampdu_reorder
 456                  * will return 0; otherwise it has consumed the mbuf
 457                  * and we should do nothing more with it.
 458                  */
 459                 if ((m->m_flags & M_AMPDU) &&
 460                     ieee80211_ampdu_reorder(ni, m) != 0) {
 461                         m = NULL;
 462                         goto out;
 463                 }
 464         resubmit_ampdu:
 465
 466                 /*
 467                  * Handle privacy requirements.  Note that we
 468                  * must not be preempted from here until after
 469                  * we (potentially) call ieee80211_crypto_demic;
 470                  * otherwise we may violate assumptions in the
 471                  * crypto cipher modules used to do delayed update
 472                  * of replay sequence numbers.
 473                  */
 474                 if (wh->i_fc[1] & IEEE80211_FC1_WEP) {
 475                         if ((vap->iv_flags & IEEE80211_F_PRIVACY) == 0) {
 476                                 /*
 477                                  * Discard encrypted frames when privacy is off.
 478                                  */
 479                                 IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
 480                                     wh, "WEP", "%s", "PRIVACY off");
 481                                 vap->iv_stats.is_rx_noprivacy++;
 482                                 IEEE80211_NODE_STAT(ni, rx_noprivacy);
 483                                 goto out;
 484                         }
 485                         key = ieee80211_crypto_decap(ni, m, hdrspace);
 486                         if (key == NULL) {
 487                                 /* NB: stats+msgs handled in crypto_decap */
 488                                 IEEE80211_NODE_STAT(ni, rx_wepfail);
 489                                 goto out;
 490                         }
 491                         wh = mtod(m, struct ieee80211_frame *);
 492                         wh->i_fc[1] &= ~IEEE80211_FC1_WEP;
 493                 } else {
 494                         /* XXX M_WEP and IEEE80211_F_PRIVACY */
 495                         key = NULL;
 496                 }
 497
 498                 /*
 499                  * Save QoS bits for use below--before we strip the header.
 500                  */
 501                 if (subtype == IEEE80211_FC0_SUBTYPE_QOS) {
 502                         qos = (dir == IEEE80211_FC1_DIR_DSTODS) ?
 503                             ((struct ieee80211_qosframe_addr4 *)wh)->i_qos[0] :
 504                             ((struct ieee80211_qosframe *)wh)->i_qos[0];
 505                 } else
 506                         qos = 0;
 507
 508                 /*
 509                  * Next up, any fragmentation.
 510                  */
 511                 if (!IEEE80211_IS_MULTICAST(wh->i_addr1)) {
 512                         m = ieee80211_defrag(ni, m, hdrspace);
 513                         if (m == NULL) {
 514                                 /* Fragment dropped or frame not complete yet */
 515                                 goto out;
 516                         }
 517                 }
 518                 wh = NULL;              /* no longer valid, catch any uses */
 519
 520                 /*
 521                  * Next strip any MSDU crypto bits.
 522                  */
 523                 if (key != NULL && !ieee80211_crypto_demic(vap, key, m, 0)) {
 524                         IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
 525                             ni->ni_macaddr, "data", "%s", "demic error");
 526                         vap->iv_stats.is_rx_demicfail++;
 527                         IEEE80211_NODE_STAT(ni, rx_demicfail);
 528                         goto out;
 529                 }
 530
 531                 /* copy to listener after decrypt */
 532                 if (ieee80211_radiotap_active_vap(vap))
 533                         ieee80211_radiotap_rx(vap, m);
 534                 need_tap = 0;
 535
 536                 /*
 537                  * Finally, strip the 802.11 header.
 538                  */
 539                 m = ieee80211_decap(vap, m, hdrspace);
 540                 if (m == NULL) {
 541                         /* XXX mask bit to check for both */
 542                         /* don't count Null data frames as errors */
 543                         if (subtype == IEEE80211_FC0_SUBTYPE_NODATA ||
 544                             subtype == IEEE80211_FC0_SUBTYPE_QOS_NULL)
 545                                 goto out;
 546                         IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
 547                             ni->ni_macaddr, "data", "%s", "decap error");
 548                         vap->iv_stats.is_rx_decap++;
 549                         IEEE80211_NODE_STAT(ni, rx_decap);
 550                         goto err;
 551                 }
 552                 eh = mtod(m, struct ether_header *);
 553                 if (!ieee80211_node_is_authorized(ni)) {
 554                         /*
 555                          * Deny any non-PAE frames received prior to
 556                          * authorization.  For open/shared-key
 557                          * authentication the port is mark authorized
 558                          * after authentication completes.  For 802.1x
 559                          * the port is not marked authorized by the
 560                          * authenticator until the handshake has completed.
 561                          */
 562                         if (eh->ether_type != htons(ETHERTYPE_PAE)) {
 563                                 IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
 564                                     eh->ether_shost, "data",
 565                                     "unauthorized port: ether type 0x%x len %u",
 566                                     eh->ether_type, m->m_pkthdr.len);
 567                                 vap->iv_stats.is_rx_unauth++;
 568                                 IEEE80211_NODE_STAT(ni, rx_unauth);
 569                                 goto err;
 570                         }
 571                 } else {
 572                         /*
 573                          * When denying unencrypted frames, discard
 574                          * any non-PAE frames received without encryption.
 575                          */
 576                         if ((vap->iv_flags & IEEE80211_F_DROPUNENC) &&
 577                             (key == NULL && (m->m_flags & M_WEP) == 0) &&
 578                             eh->ether_type != htons(ETHERTYPE_PAE)) {
 579                                 /*
 580                                  * Drop unencrypted frames.
 581                                  */
 582                                 vap->iv_stats.is_rx_unencrypted++;
 583                                 IEEE80211_NODE_STAT(ni, rx_unencrypted);
 584                                 goto out;
 585                         }
 586                 }
 587                 /* XXX require HT? */
 588                 if (qos & IEEE80211_QOS_AMSDU) {
 589                         m = ieee80211_decap_amsdu(ni, m);
 590                         if (m == NULL)
 591                                 return IEEE80211_FC0_TYPE_DATA;
 592                 } else {
 593 #ifdef IEEE80211_SUPPORT_SUPERG
 594                         m = ieee80211_decap_fastframe(vap, ni, m);
 595                         if (m == NULL)
 596                                 return IEEE80211_FC0_TYPE_DATA;
 597 #endif
 598                 }
 599                 if (dir == IEEE80211_FC1_DIR_DSTODS && ni->ni_wdsvap != NULL)
 600                         ieee80211_deliver_data(ni->ni_wdsvap, ni, m);
 601                 else
 602                         ieee80211_deliver_data(vap, ni, m);
 603                 return IEEE80211_FC0_TYPE_DATA;
 604
 605         case IEEE80211_FC0_TYPE_MGT:
 606                 vap->iv_stats.is_rx_mgmt++;
 607                 IEEE80211_NODE_STAT(ni, rx_mgmt);
 608                 if (dir != IEEE80211_FC1_DIR_NODS) {
 609                         IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
 610                             wh, "data", "incorrect dir 0x%x", dir);
 611                         vap->iv_stats.is_rx_wrongdir++;
 612                         goto err;
 613                 }
 614                 if (m->m_pkthdr.len < sizeof(struct ieee80211_frame)) {
 615                         IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
 616                             ni->ni_macaddr, "mgt", "too short: len %u",
 617                             m->m_pkthdr.len);
 618                         vap->iv_stats.is_rx_tooshort++;
 619                         goto out;
 620                 }
 621 #ifdef IEEE80211_DEBUG
 622                 if ((ieee80211_msg_debug(vap) && doprint(vap, subtype)) ||
 623                     ieee80211_msg_dumppkts(vap)) {
 624                         if_printf(ifp, "received %s from %s rssi %d\n",
 625                             ieee80211_mgt_subtype_name[subtype >>
 626                                 IEEE80211_FC0_SUBTYPE_SHIFT],
 627                             ether_sprintf(wh->i_addr2), rssi);
 628                 }
 629 #endif
 630                 if (wh->i_fc[1] & IEEE80211_FC1_WEP) {
 631                         IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
 632                             wh, NULL, "%s", "WEP set but not permitted");
 633                         vap->iv_stats.is_rx_mgtdiscard++; /* XXX */
 634                         goto out;
 635                 }
 636                 vap->iv_recv_mgmt(ni, m, subtype, rssi, nf);
 637                 goto out;
 638
 639         case IEEE80211_FC0_TYPE_CTL:
 640                 vap->iv_stats.is_rx_ctl++;
 641                 IEEE80211_NODE_STAT(ni, rx_ctrl);
 642                 vap->iv_recv_ctl(ni, m, subtype);
 643                 goto out;
 644
 645         default:
 646                 IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
 647                     wh, "bad", "frame type 0x%x", type);
 648                 /* should not come here */
 649                 break;
 650         }
 651 err:
 652         ifp->if_ierrors++;
 653 out:
 654         if (m != NULL) {
 655                 if (need_tap && ieee80211_radiotap_active_vap(vap))
 656                         ieee80211_radiotap_rx(vap, m);
 657                 m_freem(m);
 658         }
 659         return type;
 660 }
 661
 662 static int
 663 is11bclient(const uint8_t *rates, const uint8_t *xrates)
 664 {
 665         static const uint32_t brates = (1<<2*1)|(1<<2*2)|(1<<11)|(1<<2*11);
 666         int i;
 667
 668         /* NB: the 11b clients we care about will not have xrates */
 669         if (xrates != NULL || rates == NULL)
 670                 return 0;
 671         for (i = 0; i < rates[1]; i++) {
 672                 int r = rates[2+i] & IEEE80211_RATE_VAL;
 673                 if (r > 2*11 || ((1<<r) & brates) == 0)
 674                         return 0;
 675         }
 676         return 1;
 677 }
 678
 679 static void
 680 adhoc_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
 681         int subtype, int rssi, int nf)
 682 {
 683         struct ieee80211vap *vap = ni->ni_vap;
 684         struct ieee80211com *ic = ni->ni_ic;
 685         struct ieee80211_frame *wh;
 686         uint8_t *frm, *efrm, *sfrm;
 687         uint8_t *ssid, *rates, *xrates;
 688
 689         wh = mtod(m0, struct ieee80211_frame *);
 690         frm = (uint8_t *)&wh[1];
 691         efrm = mtod(m0, uint8_t *) + m0->m_len;
 692         switch (subtype) {
 693         case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
 694         case IEEE80211_FC0_SUBTYPE_BEACON: {
 695                 struct ieee80211_scanparams scan;
 696                 /*
 697                  * We process beacon/probe response
 698                  * frames to discover neighbors.
 699                  */
 700                 if (ieee80211_parse_beacon(ni, m0, &scan) != 0)
 701                         return;
 702                 /*
 703                  * Count frame now that we know it's to be processed.
 704                  */
 705                 if (subtype == IEEE80211_FC0_SUBTYPE_BEACON) {
 706                         vap->iv_stats.is_rx_beacon++;           /* XXX remove */
 707                         IEEE80211_NODE_STAT(ni, rx_beacons);
 708                 } else
 709                         IEEE80211_NODE_STAT(ni, rx_proberesp);
 710                 /*
 711                  * If scanning, just pass information to the scan module.
 712                  */
 713                 if (ic->ic_flags & IEEE80211_F_SCAN) {
 714                         if (ic->ic_flags_ext & IEEE80211_FEXT_PROBECHAN) {
 715                                 /*
 716                                  * Actively scanning a channel marked passive;
 717                                  * send a probe request now that we know there
 718                                  * is 802.11 traffic present.
 719                                  *
 720                                  * XXX check if the beacon we recv'd gives
 721                                  * us what we need and suppress the probe req
 722                                  */
 723                                 ieee80211_probe_curchan(vap, 1);
 724                                 ic->ic_flags_ext &= ~IEEE80211_FEXT_PROBECHAN;
 725                         }
 726                         ieee80211_add_scan(vap, &scan, wh, subtype, rssi, nf);
 727                         return;
 728                 }
 729                 if (scan.capinfo & IEEE80211_CAPINFO_IBSS) {
 730                         if (!IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
 731                                 /*
 732                                  * Create a new entry in the neighbor table.
 733                                  */
 734                                 ni = ieee80211_add_neighbor(vap, wh, &scan);
 735                         } else if (ni->ni_capinfo == 0) {
 736                                 /*
 737                                  * Update faked node created on transmit.
 738                                  * Note this also updates the tsf.
 739                                  */
 740                                 ieee80211_init_neighbor(ni, wh, &scan);
 741                         } else {
 742                                 /*
 743                                  * Record tsf for potential resync.
 744                                  */
 745                                 memcpy(ni->ni_tstamp.data, scan.tstamp,
 746                                         sizeof(ni->ni_tstamp));
 747                         }
 748                         if (ni != NULL) {
 749                                 IEEE80211_RSSI_LPF(ni->ni_avgrssi, rssi);
 750                                 ni->ni_noise = nf;
 751                         }
 752                 }
 753                 break;
 754         }
 755
 756         case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
 757                 if (vap->iv_state != IEEE80211_S_RUN) {
 758                         IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
 759                             wh, NULL, "wrong state %s",
 760                             ieee80211_state_name[vap->iv_state]);
 761                         vap->iv_stats.is_rx_mgtdiscard++;
 762                         return;
 763                 }
 764                 if (IEEE80211_IS_MULTICAST(wh->i_addr2)) {
 765                         /* frame must be directed */
 766                         IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
 767                             wh, NULL, "%s", "not unicast");
 768                         vap->iv_stats.is_rx_mgtdiscard++;       /* XXX stat */
 769                         return;
 770                 }
 771
 772                 /*
 773                  * prreq frame format
 774                  *      [tlv] ssid
 775                  *      [tlv] supported rates
 776                  *      [tlv] extended supported rates
 777                  */
 778                 ssid = rates = xrates = NULL;
 779                 sfrm = frm;
 780                 while (efrm - frm > 1) {
 781                         IEEE80211_VERIFY_LENGTH(efrm - frm, frm[1] + 2, return);
 782                         switch (*frm) {
 783                         case IEEE80211_ELEMID_SSID:
 784                                 ssid = frm;
 785                                 break;
 786                         case IEEE80211_ELEMID_RATES:
 787                                 rates = frm;
 788                                 break;
 789                         case IEEE80211_ELEMID_XRATES:
 790                                 xrates = frm;
 791                                 break;
 792                         }
 793                         frm += frm[1] + 2;
 794                 }
 795                 IEEE80211_VERIFY_ELEMENT(rates, IEEE80211_RATE_MAXSIZE, return);
 796                 if (xrates != NULL)
 797                         IEEE80211_VERIFY_ELEMENT(xrates,
 798                                 IEEE80211_RATE_MAXSIZE - rates[1], return);
 799                 IEEE80211_VERIFY_ELEMENT(ssid, IEEE80211_NWID_LEN, return);
 800                 IEEE80211_VERIFY_SSID(vap->iv_bss, ssid, return);
 801                 if ((vap->iv_flags & IEEE80211_F_HIDESSID) && ssid[1] == 0) {
 802                         IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
 803                             wh, NULL,
 804                             "%s", "no ssid with ssid suppression enabled");
 805                         vap->iv_stats.is_rx_ssidmismatch++; /*XXX*/
 806                         return;
 807                 }
 808
 809                 /* XXX find a better class or define it's own */
 810                 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_INPUT, wh->i_addr2,
 811                     "%s", "recv probe req");
 812                 /*
 813                  * Some legacy 11b clients cannot hack a complete
 814                  * probe response frame.  When the request includes
 815                  * only a bare-bones rate set, communicate this to
 816                  * the transmit side.
 817                  */
 818                 ieee80211_send_proberesp(vap, wh->i_addr2,
 819                     is11bclient(rates, xrates) ? IEEE80211_SEND_LEGACY_11B : 0);
 820                 break;
 821
 822         case IEEE80211_FC0_SUBTYPE_ACTION:
 823         case IEEE80211_FC0_SUBTYPE_ACTION_NOACK:
 824                 if (ni == vap->iv_bss) {
 825                         IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
 826                             wh, NULL, "%s", "unknown node");
 827                         vap->iv_stats.is_rx_mgtdiscard++;
 828                 } else if (!IEEE80211_ADDR_EQ(vap->iv_myaddr, wh->i_addr1) &&
 829                     !IEEE80211_IS_MULTICAST(wh->i_addr1)) {
 830                         IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
 831                             wh, NULL, "%s", "not for us");
 832                         vap->iv_stats.is_rx_mgtdiscard++;
 833                 } else if (vap->iv_state != IEEE80211_S_RUN) {
 834                         IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
 835                             wh, NULL, "wrong state %s",
 836                             ieee80211_state_name[vap->iv_state]);
 837                         vap->iv_stats.is_rx_mgtdiscard++;
 838                 } else {
 839                         if (ieee80211_parse_action(ni, m0) == 0)
 840                                 (void)ic->ic_recv_action(ni, wh, frm, efrm);
 841                 }
 842                 break;
 843
 844         case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
 845         case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
 846         case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
 847         case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
 848         case IEEE80211_FC0_SUBTYPE_ATIM:
 849         case IEEE80211_FC0_SUBTYPE_DISASSOC:
 850         case IEEE80211_FC0_SUBTYPE_AUTH:
 851         case IEEE80211_FC0_SUBTYPE_DEAUTH:
 852                 IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
 853                     wh, NULL, "%s", "not handled");
 854                 vap->iv_stats.is_rx_mgtdiscard++;
 855                 break;
 856
 857         default:
 858                 IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
 859                     wh, "mgt", "subtype 0x%x not handled", subtype);
 860                 vap->iv_stats.is_rx_badsubtype++;
 861                 break;
 862         }
 863 }
 864 #undef IEEE80211_VERIFY_LENGTH
 865 #undef IEEE80211_VERIFY_ELEMENT
 866
 867 static void
 868 ahdemo_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
 869         int subtype, int rssi, int nf)
 870 {
 871         struct ieee80211vap *vap = ni->ni_vap;
 872         struct ieee80211com *ic = ni->ni_ic;
 873         struct ieee80211_frame *wh;
 874
 875         /*
 876          * Process management frames when scanning; useful for doing
 877          * a site-survey.
 878          */
 879         if (ic->ic_flags & IEEE80211_F_SCAN)
 880                 adhoc_recv_mgmt(ni, m0, subtype, rssi, nf);
 881         else {
 882                 wh = mtod(m0, struct ieee80211_frame *);
 883                 switch (subtype) {
 884                 case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
 885                 case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
 886                 case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
 887                 case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
 888                 case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
 889                 case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
 890                 case IEEE80211_FC0_SUBTYPE_BEACON:
 891                 case IEEE80211_FC0_SUBTYPE_ATIM:
 892                 case IEEE80211_FC0_SUBTYPE_DISASSOC:
 893                 case IEEE80211_FC0_SUBTYPE_AUTH:
 894                 case IEEE80211_FC0_SUBTYPE_DEAUTH:
 895                 case IEEE80211_FC0_SUBTYPE_ACTION:
 896                 case IEEE80211_FC0_SUBTYPE_ACTION_NOACK:
 897                         IEEE80211_DISCARD(vap, IEEE80211_MSG_INPUT,
 898                              wh, NULL, "%s", "not handled");
 899                         vap->iv_stats.is_rx_mgtdiscard++;
 900                         break;
 901                 default:
 902                         IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
 903                              wh, "mgt", "subtype 0x%x not handled", subtype);
 904                         vap->iv_stats.is_rx_badsubtype++;
 905                         break;
 906                 }
 907         }
 908 }
 909
 910 static void
 911 adhoc_recv_ctl(struct ieee80211_node *ni, struct mbuf *m, int subtype)
 912 {
 913
 914         switch (subtype) {
 915         case IEEE80211_FC0_SUBTYPE_BAR:
 916                 ieee80211_recv_bar(ni, m);
 917                 break;
 918         }
 919 }