The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/net80211/ieee80211_ht.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * Copyright (c) 2007 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: releng/7.4/sys/net80211/ieee80211_ht.c 175962 2008-02-04 03:32:56Z sam $");
   29 #endif
   30 
   31 /*
   32  * IEEE 802.11n protocol support.
   33  */
   34 
   35 #include "opt_inet.h"
   36 
   37 #include <sys/param.h>
   38 #include <sys/kernel.h>
   39 #include <sys/systm.h> 
   40 #include <sys/endian.h>
   41  
   42 #include <sys/socket.h>
   43 
   44 #include <net/if.h>
   45 #include <net/if_media.h>
   46 #include <net/ethernet.h>
   47 
   48 #include <net80211/ieee80211_var.h>
   49 
   50 /* define here, used throughout file */
   51 #define MS(_v, _f)      (((_v) & _f) >> _f##_S)
   52 #define SM(_v, _f)      (((_v) << _f##_S) & _f)
   53 
   54 /* XXX need max array size */
   55 /* NB: these are for HT20 w/ long GI */
   56 const int ieee80211_htrates[16] = {
   57         13,             /* IFM_IEEE80211_MCS0 */
   58         26,             /* IFM_IEEE80211_MCS1 */
   59         39,             /* IFM_IEEE80211_MCS2 */
   60         52,             /* IFM_IEEE80211_MCS3 */
   61         78,             /* IFM_IEEE80211_MCS4 */
   62         104,            /* IFM_IEEE80211_MCS5 */
   63         117,            /* IFM_IEEE80211_MCS6 */
   64         130,            /* IFM_IEEE80211_MCS7 */
   65         26,             /* IFM_IEEE80211_MCS8 */
   66         52,             /* IFM_IEEE80211_MCS9 */
   67         78,             /* IFM_IEEE80211_MCS10 */
   68         104,            /* IFM_IEEE80211_MCS11 */
   69         156,            /* IFM_IEEE80211_MCS12 */
   70         208,            /* IFM_IEEE80211_MCS13 */
   71         234,            /* IFM_IEEE80211_MCS14 */
   72         260,            /* IFM_IEEE80211_MCS15 */
   73 };
   74 
   75 static const struct ieee80211_htrateset ieee80211_rateset_11n =
   76         { 16, {
   77         /* MCS: 6.5   13 19.5   26   39  52 58.5  65  13  26 */
   78                   0,   1,   2,   3,   4,  5,   6,  7,  8,  9,
   79         /*       39   52   78  104  117, 130 */
   80                  10,  11,  12,  13,  14,  15 }
   81         };
   82 
   83 #ifdef IEEE80211_AMPDU_AGE
   84 /* XXX public for sysctl hookup */
   85 int     ieee80211_ampdu_age = -1;       /* threshold for ampdu reorder q (ms) */
   86 #endif
   87 int     ieee80211_recv_bar_ena = 1;
   88 
   89 #define IEEE80211_AGGR_TIMEOUT  msecs_to_ticks(250)
   90 #define IEEE80211_AGGR_MINRETRY msecs_to_ticks(10*1000)
   91 #define IEEE80211_AGGR_MAXTRIES 3
   92 
   93 static int ieee80211_addba_request(struct ieee80211_node *ni,
   94         struct ieee80211_tx_ampdu *tap,
   95         int dialogtoken, int baparamset, int batimeout);
   96 static int ieee80211_addba_response(struct ieee80211_node *ni,
   97         struct ieee80211_tx_ampdu *tap,
   98         int code, int baparamset, int batimeout);
   99 static void ieee80211_addba_stop(struct ieee80211_node *ni,
  100         struct ieee80211_tx_ampdu *tap);
  101 static void ieee80211_aggr_recv_action(struct ieee80211_node *ni,
  102         const uint8_t *frm, const uint8_t *efrm);
  103 
  104 void
  105 ieee80211_ht_attach(struct ieee80211com *ic)
  106 {
  107 #ifdef IEEE80211_AMPDU_AGE
  108         if (ieee80211_ampdu_age == -1)
  109                 ieee80211_ampdu_age = msecs_to_ticks(500);
  110 #endif
  111 
  112         /* setup default aggregation policy */
  113         ic->ic_recv_action = ieee80211_aggr_recv_action;
  114         ic->ic_send_action = ieee80211_send_action;
  115         ic->ic_addba_request = ieee80211_addba_request;
  116         ic->ic_addba_response = ieee80211_addba_response;
  117         ic->ic_addba_stop = ieee80211_addba_stop;
  118 
  119         ic->ic_htprotmode = IEEE80211_PROT_RTSCTS;
  120         ic->ic_curhtprotmode = IEEE80211_HTINFO_OPMODE_PURE;
  121 
  122         /* XXX get from driver */
  123         ic->ic_ampdu_rxmax = IEEE80211_HTCAP_MAXRXAMPDU_8K;
  124         ic->ic_ampdu_density = IEEE80211_HTCAP_MPDUDENSITY_NA;
  125         ic->ic_ampdu_limit = ic->ic_ampdu_rxmax;
  126         ic->ic_amsdu_limit = IEEE80211_HTCAP_MAXAMSDU_3839;
  127 
  128         if (ic->ic_htcaps & IEEE80211_HTC_HT) {
  129                 /*
  130                  * Device is HT capable; enable all HT-related
  131                  * facilities by default.
  132                  * XXX these choices may be too aggressive.
  133                  */
  134                 ic->ic_flags_ext |= IEEE80211_FEXT_HT
  135                                  |  IEEE80211_FEXT_HTCOMPAT
  136                                  ;
  137                 if (ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI20)
  138                         ic->ic_flags_ext |= IEEE80211_FEXT_SHORTGI20;
  139                 /* XXX infer from channel list? */
  140                 if (ic->ic_htcaps & IEEE80211_HTCAP_CHWIDTH40) {
  141                         ic->ic_flags_ext |= IEEE80211_FEXT_USEHT40;
  142                         if (ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI40)
  143                                 ic->ic_flags_ext |= IEEE80211_FEXT_SHORTGI40;
  144                 }
  145                 /* NB: A-MPDU and A-MSDU rx are mandated, these are tx only */
  146                 ic->ic_flags_ext |= IEEE80211_FEXT_AMPDU_RX;
  147                 if (ic->ic_htcaps & IEEE80211_HTC_AMPDU)
  148                         ic->ic_flags_ext |= IEEE80211_FEXT_AMPDU_TX;
  149                 ic->ic_flags_ext |= IEEE80211_FEXT_AMSDU_RX;
  150                 if (ic->ic_htcaps & IEEE80211_HTC_AMSDU)
  151                         ic->ic_flags_ext |= IEEE80211_FEXT_AMSDU_TX;
  152         }
  153 }
  154 
  155 void
  156 ieee80211_ht_detach(struct ieee80211com *ic)
  157 {
  158 }
  159 
  160 static void
  161 ht_announce(struct ieee80211com *ic, int mode,
  162         const struct ieee80211_htrateset *rs)
  163 {
  164         struct ifnet *ifp = ic->ic_ifp;
  165         int i, rate, mword;
  166 
  167         if_printf(ifp, "%s MCS: ", ieee80211_phymode_name[mode]);
  168         for (i = 0; i < rs->rs_nrates; i++) {
  169                 mword = ieee80211_rate2media(ic,
  170                     rs->rs_rates[i] | IEEE80211_RATE_MCS, mode);
  171                 if (IFM_SUBTYPE(mword) != IFM_IEEE80211_MCS)
  172                         continue;
  173                 rate = ieee80211_htrates[rs->rs_rates[i]];
  174                 printf("%s%d%sMbps", (i != 0 ? " " : ""),
  175                     rate / 2, ((rate & 0x1) != 0 ? ".5" : ""));
  176         }
  177         printf("\n");
  178 }
  179 
  180 void
  181 ieee80211_ht_announce(struct ieee80211com *ic)
  182 {
  183         if (isset(ic->ic_modecaps, IEEE80211_MODE_11NA))
  184                 ht_announce(ic, IEEE80211_MODE_11NA, &ieee80211_rateset_11n);
  185         if (isset(ic->ic_modecaps, IEEE80211_MODE_11NG))
  186                 ht_announce(ic, IEEE80211_MODE_11NG, &ieee80211_rateset_11n);
  187 }
  188 
  189 const struct ieee80211_htrateset *
  190 ieee80211_get_suphtrates(struct ieee80211com *ic,
  191         const struct ieee80211_channel *c)
  192 {
  193         return &ieee80211_rateset_11n;
  194 }
  195 
  196 /*
  197  * Receive processing.
  198  */
  199 
  200 /*
  201  * Decap the encapsulated A-MSDU frames and dispatch all but
  202  * the last for delivery.  The last frame is returned for 
  203  * delivery via the normal path.
  204  */
  205 struct mbuf *
  206 ieee80211_decap_amsdu(struct ieee80211_node *ni, struct mbuf *m)
  207 {
  208         struct ieee80211com *ic = ni->ni_ic;
  209         int framelen;
  210         struct mbuf *n;
  211 
  212         /* discard 802.3 header inserted by ieee80211_decap */
  213         m_adj(m, sizeof(struct ether_header));
  214 
  215         ic->ic_stats.is_amsdu_decap++;
  216 
  217         for (;;) {
  218                 /*
  219                  * Decap the first frame, bust it apart from the
  220                  * remainder and deliver.  We leave the last frame
  221                  * delivery to the caller (for consistency with other
  222                  * code paths, could also do it here).
  223                  */
  224                 m = ieee80211_decap1(m, &framelen);
  225                 if (m == NULL) {
  226                         IEEE80211_DISCARD_MAC(ic, IEEE80211_MSG_ANY,
  227                             ni->ni_macaddr, "a-msdu", "%s", "decap failed");
  228                         ic->ic_stats.is_amsdu_tooshort++;
  229                         return NULL;
  230                 }
  231                 if (m->m_pkthdr.len == framelen)
  232                         break;
  233                 n = m_split(m, framelen, M_NOWAIT);
  234                 if (n == NULL) {
  235                         IEEE80211_DISCARD_MAC(ic, IEEE80211_MSG_ANY,
  236                             ni->ni_macaddr, "a-msdu",
  237                             "%s", "unable to split encapsulated frames");
  238                         ic->ic_stats.is_amsdu_split++;
  239                         m_freem(m);                     /* NB: must reclaim */
  240                         return NULL;
  241                 }
  242                 ieee80211_deliver_data(ic, ni, m);
  243 
  244                 /*
  245                  * Remove frame contents; each intermediate frame
  246                  * is required to be aligned to a 4-byte boundary.
  247                  */
  248                 m = n;
  249                 m_adj(m, roundup2(framelen, 4) - framelen);     /* padding */
  250         }
  251         return m;                               /* last delivered by caller */
  252 }
  253 
  254 /*
  255  * Start A-MPDU rx/re-order processing for the specified TID.
  256  */
  257 static void
  258 ampdu_rx_start(struct ieee80211_rx_ampdu *rap, int bufsiz, int start)
  259 {
  260         memset(rap, 0, sizeof(*rap));
  261         rap->rxa_wnd = (bufsiz == 0) ?
  262             IEEE80211_AGGR_BAWMAX : min(bufsiz, IEEE80211_AGGR_BAWMAX);
  263         rap->rxa_start = start;
  264         rap->rxa_flags |= IEEE80211_AGGR_XCHGPEND;
  265 }
  266 
  267 /*
  268  * Purge all frames in the A-MPDU re-order queue.
  269  */
  270 static void
  271 ampdu_rx_purge(struct ieee80211_rx_ampdu *rap)
  272 {
  273         struct mbuf *m;
  274         int i;
  275 
  276         for (i = 0; i < rap->rxa_wnd; i++) {
  277                 m = rap->rxa_m[i];
  278                 if (m != NULL) {
  279                         rap->rxa_m[i] = NULL;
  280                         rap->rxa_qbytes -= m->m_pkthdr.len;
  281                         m_freem(m);
  282                         if (--rap->rxa_qframes == 0)
  283                                 break;
  284                 }
  285         }
  286         KASSERT(rap->rxa_qbytes == 0 && rap->rxa_qframes == 0,
  287             ("lost %u data, %u frames on ampdu rx q",
  288             rap->rxa_qbytes, rap->rxa_qframes));
  289 }
  290 
  291 /*
  292  * Stop A-MPDU rx processing for the specified TID.
  293  */
  294 static void
  295 ampdu_rx_stop(struct ieee80211_rx_ampdu *rap)
  296 {
  297         rap->rxa_flags &= ~IEEE80211_AGGR_XCHGPEND;
  298         ampdu_rx_purge(rap);
  299 }
  300 
  301 /*
  302  * Dispatch a frame from the A-MPDU reorder queue.  The
  303  * frame is fed back into ieee80211_input marked with an
  304  * M_AMPDU flag so it doesn't come back to us (it also
  305  * permits ieee80211_input to optimize re-processing).
  306  */
  307 static __inline void
  308 ampdu_dispatch(struct ieee80211_node *ni, struct mbuf *m)
  309 {
  310         m->m_flags |= M_AMPDU;  /* bypass normal processing */
  311         /* NB: rssi, noise, and rstamp are ignored w/ M_AMPDU set */
  312         (void) ieee80211_input(ni->ni_ic, m, ni, 0, 0, 0);
  313 }
  314 
  315 /*
  316  * Dispatch as many frames as possible from the re-order queue.
  317  * Frames will always be "at the front"; we process all frames
  318  * up to the first empty slot in the window.  On completion we
  319  * cleanup state if there are still pending frames in the current
  320  * BA window.  We assume the frame at slot 0 is already handled
  321  * by the caller; we always start at slot 1.
  322  */
  323 static void
  324 ampdu_rx_dispatch(struct ieee80211_rx_ampdu *rap, struct ieee80211_node *ni)
  325 {
  326         struct ieee80211com *ic = ni->ni_ic;
  327         struct mbuf *m;
  328         int i;
  329 
  330         /* flush run of frames */
  331         for (i = 1; i < rap->rxa_wnd; i++) {
  332                 m = rap->rxa_m[i];
  333                 if (m == NULL)
  334                         break;
  335                 rap->rxa_m[i] = NULL;
  336                 rap->rxa_qbytes -= m->m_pkthdr.len;
  337                 rap->rxa_qframes--;
  338 
  339                 ampdu_dispatch(ni, m);
  340         }
  341         /*
  342          * If frames remain, copy the mbuf pointers down so
  343          * they correspond to the offsets in the new window.
  344          */
  345         if (rap->rxa_qframes != 0) {
  346                 int n = rap->rxa_qframes, j;
  347                 for (j = i+1; j < rap->rxa_wnd; j++) {
  348                         if (rap->rxa_m[j] != NULL) {
  349                                 rap->rxa_m[j-i] = rap->rxa_m[j];
  350                                 rap->rxa_m[j] = NULL;
  351                                 if (--n == 0)
  352                                         break;
  353                         }
  354                 }
  355                 KASSERT(n == 0, ("lost %d frames", n));
  356                 ic->ic_stats.is_ampdu_rx_copy += rap->rxa_qframes;
  357         }
  358         /*
  359          * Adjust the start of the BA window to
  360          * reflect the frames just dispatched.
  361          */
  362         rap->rxa_start = IEEE80211_SEQ_ADD(rap->rxa_start, i);
  363         ic->ic_stats.is_ampdu_rx_oor += i;
  364 }
  365 
  366 #ifdef IEEE80211_AMPDU_AGE
  367 /*
  368  * Dispatch all frames in the A-MPDU re-order queue.
  369  */
  370 static void
  371 ampdu_rx_flush(struct ieee80211_node *ni, struct ieee80211_rx_ampdu *rap)
  372 {
  373         struct ieee80211com *ic = ni->ni_ic;
  374         struct mbuf *m;
  375         int i;
  376 
  377         for (i = 0; i < rap->rxa_wnd; i++) {
  378                 m = rap->rxa_m[i];
  379                 if (m == NULL)
  380                         continue;
  381                 rap->rxa_m[i] = NULL;
  382                 rap->rxa_qbytes -= m->m_pkthdr.len;
  383                 rap->rxa_qframes--;
  384                 ic->ic_stats.is_ampdu_rx_oor++;
  385 
  386                 ampdu_dispatch(ni, m);
  387                 if (rap->rxa_qframes == 0)
  388                         break;
  389         }
  390 }
  391 #endif /* IEEE80211_AMPDU_AGE */
  392 
  393 /*
  394  * Dispatch all frames in the A-MPDU re-order queue
  395  * preceding the specified sequence number.  This logic
  396  * handles window moves due to a received MSDU or BAR.
  397  */
  398 static void
  399 ampdu_rx_flush_upto(struct ieee80211_node *ni,
  400         struct ieee80211_rx_ampdu *rap, ieee80211_seq winstart)
  401 {
  402         struct ieee80211com *ic = ni->ni_ic;
  403         struct mbuf *m;
  404         ieee80211_seq seqno;
  405         int i;
  406 
  407         /*
  408          * Flush any complete MSDU's with a sequence number lower
  409          * than winstart.  Gaps may exist.  Note that we may actually
  410          * dispatch frames past winstart if a run continues; this is
  411          * an optimization that avoids having to do a separate pass
  412          * to dispatch frames after moving the BA window start.
  413          */
  414         seqno = rap->rxa_start;
  415         for (i = 0; i < rap->rxa_wnd; i++) {
  416                 m = rap->rxa_m[i];
  417                 if (m != NULL) {
  418                         rap->rxa_m[i] = NULL;
  419                         rap->rxa_qbytes -= m->m_pkthdr.len;
  420                         rap->rxa_qframes--;
  421                         ic->ic_stats.is_ampdu_rx_oor++;
  422 
  423                         ampdu_dispatch(ni, m);
  424                 } else {
  425                         if (!IEEE80211_SEQ_BA_BEFORE(seqno, winstart))
  426                                 break;
  427                 }
  428                 seqno = IEEE80211_SEQ_INC(seqno);
  429         }
  430         /*
  431          * If frames remain, copy the mbuf pointers down so
  432          * they correspond to the offsets in the new window.
  433          */
  434         if (rap->rxa_qframes != 0) {
  435                 int n = rap->rxa_qframes, j;
  436                 for (j = i+1; j < rap->rxa_wnd; j++) {
  437                         if (rap->rxa_m[j] != NULL) {
  438                                 rap->rxa_m[j-i] = rap->rxa_m[j];
  439                                 rap->rxa_m[j] = NULL;
  440                                 if (--n == 0)
  441                                         break;
  442                         }
  443                 }
  444                 KASSERT(n == 0, ("%s: lost %d frames, qframes %d off %d "
  445                     "BA win <%d:%d> winstart %d",
  446                     __func__, n, rap->rxa_qframes, i, rap->rxa_start,
  447                     IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
  448                     winstart));
  449                 ic->ic_stats.is_ampdu_rx_copy += rap->rxa_qframes;
  450         }
  451         /*
  452          * Move the start of the BA window; we use the
  453          * sequence number of the last MSDU that was
  454          * passed up the stack+1 or winstart if stopped on
  455          * a gap in the reorder buffer.
  456          */
  457         rap->rxa_start = seqno;
  458 }
  459 
  460 /*
  461  * Process a received QoS data frame for an HT station.  Handle
  462  * A-MPDU reordering: if this frame is received out of order
  463  * and falls within the BA window hold onto it.  Otherwise if
  464  * this frame completes a run, flush any pending frames.  We
  465  * return 1 if the frame is consumed.  A 0 is returned if
  466  * the frame should be processed normally by the caller.
  467  */
  468 int
  469 ieee80211_ampdu_reorder(struct ieee80211_node *ni, struct mbuf *m)
  470 {
  471 #define IEEE80211_FC0_QOSDATA \
  472         (IEEE80211_FC0_TYPE_DATA|IEEE80211_FC0_SUBTYPE_QOS|IEEE80211_FC0_VERSION_0)
  473 #define PROCESS         0       /* caller should process frame */
  474 #define CONSUMED        1       /* frame consumed, caller does nothing */
  475         struct ieee80211com *ic = ni->ni_ic;
  476         struct ieee80211_qosframe *wh;
  477         struct ieee80211_rx_ampdu *rap;
  478         ieee80211_seq rxseq;
  479         uint8_t tid;
  480         int off;
  481 
  482         KASSERT(ni->ni_flags & IEEE80211_NODE_HT, ("not an HT sta"));
  483 
  484         /* NB: m_len known to be sufficient */
  485         wh = mtod(m, struct ieee80211_qosframe *);
  486         KASSERT(wh->i_fc[0] == IEEE80211_FC0_QOSDATA, ("not QoS data"));
  487 
  488         if ((wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) == IEEE80211_FC1_DIR_DSTODS)
  489                 tid = ((struct ieee80211_qosframe_addr4 *)wh)->i_qos[0];
  490         else
  491                 tid = wh->i_qos[0];
  492         tid &= IEEE80211_QOS_TID;
  493         rap = &ni->ni_rx_ampdu[tid];
  494         if ((rap->rxa_flags & IEEE80211_AGGR_XCHGPEND) == 0) {
  495                 /*
  496                  * No ADDBA request yet, don't touch.
  497                  */
  498                 return PROCESS;
  499         }
  500         rxseq = le16toh(*(uint16_t *)wh->i_seq) >> IEEE80211_SEQ_SEQ_SHIFT;
  501         rap->rxa_nframes++;
  502 again:
  503         if (rxseq == rap->rxa_start) {
  504                 /*
  505                  * First frame in window.
  506                  */
  507                 if (rap->rxa_qframes != 0) {
  508                         /*
  509                          * Dispatch as many packets as we can.
  510                          */
  511                         KASSERT(rap->rxa_m[0] == NULL, ("unexpected dup"));
  512                         ampdu_dispatch(ni, m);
  513                         ampdu_rx_dispatch(rap, ni);
  514                         return CONSUMED;
  515                 } else {
  516                         /*
  517                          * In order; advance window and notify
  518                          * caller to dispatch directly.
  519                          */
  520                         rap->rxa_start = IEEE80211_SEQ_INC(rxseq);
  521                         return PROCESS;
  522                 }
  523         }
  524         /*
  525          * Frame is out of order; store if in the BA window.
  526          */
  527         /* calculate offset in BA window */
  528         off = IEEE80211_SEQ_SUB(rxseq, rap->rxa_start);
  529         if (off < rap->rxa_wnd) {
  530                 /*
  531                  * Common case (hopefully): in the BA window.
  532                  * Sec 9.10.7.6 a) (D2.04 p.118 line 47)
  533                  */
  534 #ifdef IEEE80211_AMPDU_AGE
  535                 /* 
  536                  * Check for frames sitting too long in the reorder queue.
  537                  * This should only ever happen if frames are not delivered
  538                  * without the sender otherwise notifying us (e.g. with a
  539                  * BAR to move the window).  Typically this happens because
  540                  * of vendor bugs that cause the sequence number to jump.
  541                  * When this happens we get a gap in the reorder queue that
  542                  * leaves frame sitting on the queue until they get pushed
  543                  * out due to window moves.  When the vendor does not send
  544                  * BAR this move only happens due to explicit packet sends
  545                  *
  546                  * NB: we only track the time of the oldest frame in the
  547                  * reorder q; this means that if we flush we might push
  548                  * frames that still "new"; if this happens then subsequent
  549                  * frames will result in BA window moves which cost something
  550                  * but is still better than a big throughput dip.
  551                  */
  552                 if (rap->rxa_qframes != 0) {
  553                         /* XXX honor batimeout? */
  554                         if (ticks - rap->rxa_age > ieee80211_ampdu_age) {
  555                                 /*
  556                                  * Too long since we received the first
  557                                  * frame; flush the reorder buffer.
  558                                  */
  559                                 if (rap->rxa_qframes != 0) {
  560                                         ic->ic_stats.is_ampdu_rx_age +=
  561                                             rap->rxa_qframes;
  562                                         ampdu_rx_flush(ni, rap);
  563                                 }
  564                                 rap->rxa_start = IEEE80211_SEQ_INC(rxseq);
  565                                 return PROCESS;
  566                         }
  567                 } else {
  568                         /*
  569                          * First frame, start aging timer.
  570                          */
  571                         rap->rxa_age = ticks;
  572                 }
  573 #endif /* IEEE80211_AMPDU_AGE */
  574                 /* save packet */
  575                 if (rap->rxa_m[off] == NULL) {
  576                         rap->rxa_m[off] = m;
  577                         rap->rxa_qframes++;
  578                         rap->rxa_qbytes += m->m_pkthdr.len;
  579                         ic->ic_stats.is_ampdu_rx_reorder++;
  580                 } else {
  581                         IEEE80211_DISCARD_MAC(ic,
  582                             IEEE80211_MSG_INPUT | IEEE80211_MSG_11N,
  583                             ni->ni_macaddr, "a-mpdu duplicate",
  584                             "seqno %u tid %u BA win <%u:%u>",
  585                             rxseq, tid, rap->rxa_start,
  586                             IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1));
  587                         ic->ic_stats.is_rx_dup++;
  588                         IEEE80211_NODE_STAT(ni, rx_dup);
  589                         m_freem(m);
  590                 }
  591                 return CONSUMED;
  592         }
  593         if (off < IEEE80211_SEQ_BA_RANGE) {
  594                 /*
  595                  * Outside the BA window, but within range;
  596                  * flush the reorder q and move the window.
  597                  * Sec 9.10.7.6 b) (D2.04 p.118 line 60)
  598                  */
  599                 IEEE80211_NOTE(ic, IEEE80211_MSG_11N, ni,
  600                     "move BA win <%u:%u> (%u frames) rxseq %u tid %u",
  601                     rap->rxa_start,
  602                     IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
  603                     rap->rxa_qframes, rxseq, tid);
  604                 ic->ic_stats.is_ampdu_rx_move++;
  605 
  606                 /*
  607                  * The spec says to flush frames up to but not including:
  608                  *      WinStart_B = rxseq - rap->rxa_wnd + 1
  609                  * Then insert the frame or notify the caller to process
  610                  * it immediately.  We can safely do this by just starting
  611                  * over again because we know the frame will now be within
  612                  * the BA window.
  613                  */
  614                 /* NB: rxa_wnd known to be >0 */
  615                 ampdu_rx_flush_upto(ni, rap,
  616                     IEEE80211_SEQ_SUB(rxseq, rap->rxa_wnd-1));
  617                 goto again;
  618         } else {
  619                 /*
  620                  * Outside the BA window and out of range; toss.
  621                  * Sec 9.10.7.6 c) (D2.04 p.119 line 16)
  622                  */
  623                 IEEE80211_DISCARD_MAC(ic,
  624                     IEEE80211_MSG_INPUT | IEEE80211_MSG_11N, ni->ni_macaddr,
  625                     "MSDU", "BA win <%u:%u> (%u frames) rxseq %u tid %u%s",
  626                     rap->rxa_start,
  627                     IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
  628                     rap->rxa_qframes, rxseq, tid,
  629                     wh->i_fc[1] & IEEE80211_FC1_RETRY ? " (retransmit)" : "");
  630                 ic->ic_stats.is_ampdu_rx_drop++;
  631                 IEEE80211_NODE_STAT(ni, rx_drop);
  632                 m_freem(m);
  633                 return CONSUMED;
  634         }
  635 #undef CONSUMED
  636 #undef PROCESS
  637 #undef IEEE80211_FC0_QOSDATA
  638 }
  639 
  640 /*
  641  * Process a BAR ctl frame.  Dispatch all frames up to
  642  * the sequence number of the frame.  If this frame is
  643  * out of range it's discarded.
  644  */
  645 void
  646 ieee80211_recv_bar(struct ieee80211_node *ni, struct mbuf *m0)
  647 {
  648         struct ieee80211com *ic = ni->ni_ic;
  649         struct ieee80211_frame_bar *wh;
  650         struct ieee80211_rx_ampdu *rap;
  651         ieee80211_seq rxseq;
  652         int tid, off;
  653 
  654         if (!ieee80211_recv_bar_ena) {
  655 #if 0
  656                 IEEE80211_DISCARD_MAC(ic, IEEE80211_MSG_11N,
  657                     ni->ni_macaddr, "BAR", "%s", "processing disabled");
  658 #endif
  659                 ic->ic_stats.is_ampdu_bar_bad++;
  660                 return;
  661         }
  662         wh = mtod(m0, struct ieee80211_frame_bar *);
  663         /* XXX check basic BAR */
  664         tid = MS(le16toh(wh->i_ctl), IEEE80211_BAR_TID);
  665         rap = &ni->ni_rx_ampdu[tid];
  666         if ((rap->rxa_flags & IEEE80211_AGGR_XCHGPEND) == 0) {
  667                 /*
  668                  * No ADDBA request yet, don't touch.
  669                  */
  670                 IEEE80211_DISCARD_MAC(ic,
  671                     IEEE80211_MSG_INPUT | IEEE80211_MSG_11N,
  672                     ni->ni_macaddr, "BAR", "no BA stream, tid %u", tid);
  673                 ic->ic_stats.is_ampdu_bar_bad++;
  674                 return;
  675         }
  676         ic->ic_stats.is_ampdu_bar_rx++;
  677         rxseq = le16toh(wh->i_seq) >> IEEE80211_SEQ_SEQ_SHIFT;
  678         if (rxseq == rap->rxa_start)
  679                 return;
  680         /* calculate offset in BA window */
  681         off = IEEE80211_SEQ_SUB(rxseq, rap->rxa_start);
  682         if (off < IEEE80211_SEQ_BA_RANGE) {
  683                 /*
  684                  * Flush the reorder q up to rxseq and move the window.
  685                  * Sec 9.10.7.6 a) (D2.04 p.119 line 22)
  686                  */
  687                 IEEE80211_NOTE(ic, IEEE80211_MSG_11N, ni,
  688                     "BAR moves BA win <%u:%u> (%u frames) rxseq %u tid %u",
  689                     rap->rxa_start,
  690                     IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
  691                     rap->rxa_qframes, rxseq, tid);
  692                 ic->ic_stats.is_ampdu_bar_move++;
  693 
  694                 ampdu_rx_flush_upto(ni, rap, rxseq);
  695                 if (off >= rap->rxa_wnd) {
  696                         /*
  697                          * BAR specifies a window start to the right of BA
  698                          * window; we must move it explicitly since
  699                          * ampdu_rx_flush_upto will not.
  700                          */
  701                         rap->rxa_start = rxseq;
  702                 }
  703         } else {
  704                 /*
  705                  * Out of range; toss.
  706                  * Sec 9.10.7.6 b) (D2.04 p.119 line 41)
  707                  */
  708                 IEEE80211_DISCARD_MAC(ic,
  709                     IEEE80211_MSG_INPUT | IEEE80211_MSG_11N, ni->ni_macaddr,
  710                     "BAR", "BA win <%u:%u> (%u frames) rxseq %u tid %u%s",
  711                     rap->rxa_start,
  712                     IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
  713                     rap->rxa_qframes, rxseq, tid,
  714                     wh->i_fc[1] & IEEE80211_FC1_RETRY ? " (retransmit)" : "");
  715                 ic->ic_stats.is_ampdu_bar_oow++;
  716                 IEEE80211_NODE_STAT(ni, rx_drop);
  717         }
  718 }
  719 
  720 /*
  721  * Setup HT-specific state in a node.  Called only
  722  * when HT use is negotiated so we don't do extra
  723  * work for temporary and/or legacy sta's.
  724  */
  725 void
  726 ieee80211_ht_node_init(struct ieee80211_node *ni, const uint8_t *htcap)
  727 {
  728         struct ieee80211_tx_ampdu *tap;
  729         int ac;
  730 
  731         if (ni->ni_flags & IEEE80211_NODE_HT) {
  732                 /*
  733                  * Clean AMPDU state on re-associate.  This handles the case
  734                  * where a station leaves w/o notifying us and then returns
  735                  * before node is reaped for inactivity.
  736                  */
  737                 ieee80211_ht_node_cleanup(ni);
  738         }
  739         ieee80211_parse_htcap(ni, htcap);
  740         for (ac = 0; ac < WME_NUM_AC; ac++) {
  741                 tap = &ni->ni_tx_ampdu[ac];
  742                 tap->txa_ac = ac;
  743                 /* NB: further initialization deferred */
  744         }
  745         ni->ni_flags |= IEEE80211_NODE_HT | IEEE80211_NODE_AMPDU;
  746 }
  747 
  748 /*
  749  * Cleanup HT-specific state in a node.  Called only
  750  * when HT use has been marked.
  751  */
  752 void
  753 ieee80211_ht_node_cleanup(struct ieee80211_node *ni)
  754 {
  755         struct ieee80211com *ic = ni->ni_ic;
  756         int i;
  757 
  758         KASSERT(ni->ni_flags & IEEE80211_NODE_HT, ("not an HT node"));
  759 
  760         /* XXX optimize this */
  761         for (i = 0; i < WME_NUM_AC; i++) {
  762                 struct ieee80211_tx_ampdu *tap = &ni->ni_tx_ampdu[i];
  763                 if (tap->txa_flags & IEEE80211_AGGR_SETUP) {
  764                         /*
  765                          * Stop BA stream if setup so driver has a chance
  766                          * to reclaim any resources it might have allocated.
  767                          */
  768                         ic->ic_addba_stop(ni, &ni->ni_tx_ampdu[i]);
  769                         IEEE80211_TAPQ_DESTROY(tap);
  770                         /* NB: clearing NAK means we may re-send ADDBA */ 
  771                         tap->txa_flags &=
  772                             ~(IEEE80211_AGGR_SETUP | IEEE80211_AGGR_NAK);
  773                 }
  774         }
  775         for (i = 0; i < WME_NUM_TID; i++)
  776                 ampdu_rx_stop(&ni->ni_rx_ampdu[i]);
  777 
  778         ni->ni_htcap = 0;
  779         ni->ni_flags &= ~(IEEE80211_NODE_HT | IEEE80211_NODE_HTCOMPAT |
  780                 IEEE80211_NODE_AMPDU);
  781 }
  782 
  783 static struct ieee80211_channel *
  784 findhtchan(struct ieee80211com *ic, struct ieee80211_channel *c, int htflags)
  785 {
  786         return ieee80211_find_channel(ic, c->ic_freq,
  787             (c->ic_flags &~ IEEE80211_CHAN_HT) | htflags);
  788 }
  789 
  790 /*
  791  * Adjust a channel to be HT/non-HT according to the vap's configuration.
  792  */
  793 struct ieee80211_channel *
  794 ieee80211_ht_adjust_channel(struct ieee80211com *ic,
  795         struct ieee80211_channel *chan, int flags)
  796 {
  797         struct ieee80211_channel *c;
  798 
  799         if (flags & IEEE80211_FEXT_HT) {
  800                 /* promote to HT if possible */
  801                 if (flags & IEEE80211_FEXT_USEHT40) {
  802                         if (!IEEE80211_IS_CHAN_HT40(chan)) {
  803                                 /* NB: arbitrarily pick ht40+ over ht40- */
  804                                 c = findhtchan(ic, chan, IEEE80211_CHAN_HT40U);
  805                                 if (c == NULL)
  806                                         c = findhtchan(ic, chan,
  807                                                 IEEE80211_CHAN_HT40D);
  808                                 if (c == NULL)
  809                                         c = findhtchan(ic, chan,
  810                                                 IEEE80211_CHAN_HT20);
  811                                 if (c != NULL)
  812                                         chan = c;
  813                         }
  814                 } else if (!IEEE80211_IS_CHAN_HT20(chan)) {
  815                         c = findhtchan(ic, chan, IEEE80211_CHAN_HT20);
  816                         if (c != NULL)
  817                                 chan = c;
  818                 }
  819         } else if (IEEE80211_IS_CHAN_HT(chan)) {
  820                 /* demote to legacy, HT use is disabled */
  821                 c = ieee80211_find_channel(ic, chan->ic_freq,
  822                     chan->ic_flags &~ IEEE80211_CHAN_HT);
  823                 if (c != NULL)
  824                         chan = c;
  825         }
  826         return chan;
  827 }
  828 
  829 /*
  830  * Setup HT-specific state for a legacy WDS peer.
  831  */
  832 void
  833 ieee80211_ht_wds_init(struct ieee80211_node *ni)
  834 {
  835         struct ieee80211com *ic = ni->ni_ic;
  836         struct ieee80211_tx_ampdu *tap;
  837         int ac;
  838 
  839         KASSERT(ic->ic_flags_ext & IEEE80211_FEXT_HT, ("no HT requested"));
  840 
  841         /* XXX check scan cache in case peer has an ap and we have info */
  842         /*
  843          * If setup with a legacy channel; locate an HT channel.
  844          * Otherwise if the inherited channel (from a companion
  845          * AP) is suitable use it so we use the same location
  846          * for the extension channel).
  847          */
  848         ni->ni_chan = ieee80211_ht_adjust_channel(ic, ni->ni_chan,
  849             ic->ic_flags_ext);
  850 
  851         ni->ni_htcap = 0;
  852         if (ic->ic_flags_ext & IEEE80211_FEXT_SHORTGI20)
  853                 ni->ni_htcap |= IEEE80211_HTCAP_SHORTGI20;
  854         if (IEEE80211_IS_CHAN_HT40(ni->ni_chan)) {
  855                 ni->ni_htcap |= IEEE80211_HTCAP_CHWIDTH40;
  856                 ni->ni_chw = 40;
  857                 if (IEEE80211_IS_CHAN_HT40U(ni->ni_chan))
  858                         ni->ni_ht2ndchan = IEEE80211_HTINFO_2NDCHAN_ABOVE;
  859                 else if (IEEE80211_IS_CHAN_HT40D(ni->ni_chan))
  860                         ni->ni_ht2ndchan = IEEE80211_HTINFO_2NDCHAN_BELOW;
  861                 if (ic->ic_flags_ext & IEEE80211_FEXT_SHORTGI40)
  862                         ni->ni_htcap |= IEEE80211_HTCAP_SHORTGI40;
  863         } else {
  864                 ni->ni_chw = 20;
  865                 ni->ni_ht2ndchan = IEEE80211_HTINFO_2NDCHAN_NONE;
  866         }
  867         ni->ni_htctlchan = ni->ni_chan->ic_ieee;
  868 
  869         ni->ni_htopmode = 0;            /* XXX need protection state */
  870         ni->ni_htstbc = 0;              /* XXX need info */
  871 
  872         for (ac = 0; ac < WME_NUM_AC; ac++) {
  873                 tap = &ni->ni_tx_ampdu[ac];
  874                 tap->txa_ac = ac;
  875         }
  876         /* NB: AMPDU tx/rx governed by IEEE80211_FEXT_AMPDU_{TX,RX} */
  877         ni->ni_flags |= IEEE80211_NODE_HT | IEEE80211_NODE_AMPDU;
  878 }
  879 
  880 /*
  881  * Notify hostap vaps of a change in the HTINFO ie.
  882  */
  883 static void
  884 htinfo_notify(struct ieee80211com *ic)
  885 {
  886         if (ic->ic_opmode != IEEE80211_M_HOSTAP)
  887                 return;
  888         IEEE80211_NOTE(ic,
  889             IEEE80211_MSG_ASSOC | IEEE80211_MSG_11N,
  890             ic->ic_bss,
  891             "HT bss occupancy change: %d sta, %d ht, "
  892             "%d ht40%s, HT protmode now 0x%x"
  893             , ic->ic_sta_assoc
  894             , ic->ic_ht_sta_assoc
  895             , ic->ic_ht40_sta_assoc
  896             , (ic->ic_flags_ext & IEEE80211_FEXT_NONHT_PR) ?
  897                  ", non-HT sta present" : ""
  898             , ic->ic_curhtprotmode);
  899         ieee80211_beacon_notify(ic, IEEE80211_BEACON_HTINFO);
  900 }
  901 
  902 /*
  903  * Calculate HT protection mode from current
  904  * state and handle updates.
  905  */
  906 static void
  907 htinfo_update(struct ieee80211com *ic)
  908 {
  909         uint8_t protmode;
  910 
  911         if (ic->ic_flags_ext & IEEE80211_FEXT_NONHT_PR) {
  912                 protmode = IEEE80211_HTINFO_OPMODE_PROTOPT
  913                          | IEEE80211_HTINFO_NONHT_PRESENT;
  914         } else if (ic->ic_sta_assoc != ic->ic_ht_sta_assoc) {
  915                 protmode = IEEE80211_HTINFO_OPMODE_MIXED
  916                          | IEEE80211_HTINFO_NONHT_PRESENT;
  917         } else if (IEEE80211_IS_CHAN_HT40(ic->ic_bsschan) && 
  918             ic->ic_sta_assoc != ic->ic_ht40_sta_assoc) {
  919                 protmode = IEEE80211_HTINFO_OPMODE_HT20PR;
  920         } else {
  921                 protmode = IEEE80211_HTINFO_OPMODE_PURE;
  922         }
  923         if (protmode != ic->ic_curhtprotmode) {
  924                 ic->ic_curhtprotmode = protmode;
  925                 htinfo_notify(ic);
  926         }
  927 }
  928 
  929 /*
  930  * Handle an HT station joining a BSS.
  931  */
  932 void
  933 ieee80211_ht_node_join(struct ieee80211_node *ni)
  934 {
  935         struct ieee80211com *ic = ni->ni_ic;
  936 
  937         IEEE80211_LOCK_ASSERT(ic);
  938 
  939         if (ni->ni_flags & IEEE80211_NODE_HT) {
  940                 ic->ic_ht_sta_assoc++;
  941                 if (ni->ni_chw == 40)
  942                         ic->ic_ht40_sta_assoc++;
  943         }
  944         htinfo_update(ic);
  945 }
  946 
  947 /*
  948  * Handle an HT station leaving a BSS.
  949  */
  950 void
  951 ieee80211_ht_node_leave(struct ieee80211_node *ni)
  952 {
  953         struct ieee80211com *ic = ni->ni_ic;
  954 
  955         IEEE80211_LOCK_ASSERT(ic);
  956 
  957         if (ni->ni_flags & IEEE80211_NODE_HT) {
  958                 ic->ic_ht_sta_assoc--;
  959                 if (ni->ni_chw == 40)
  960                         ic->ic_ht40_sta_assoc--;
  961         }
  962         htinfo_update(ic);
  963 }
  964 
  965 /*
  966  * Public version of htinfo_update; used for processing
  967  * beacon frames from overlapping bss in hostap_recv_mgmt.
  968  */
  969 void
  970 ieee80211_htinfo_update(struct ieee80211com *ic, int protmode)
  971 {
  972         if (protmode != ic->ic_curhtprotmode) {
  973                 ic->ic_curhtprotmode = protmode;
  974                 htinfo_notify(ic);
  975         }
  976 }
  977 
  978 /*
  979  * Time out presence of an overlapping bss with non-HT
  980  * stations.  When operating in hostap mode we listen for
  981  * beacons from other stations and if we identify a non-HT
  982  * station is present we update the opmode field of the
  983  * HTINFO ie.  To identify when all non-HT stations are
  984  * gone we time out this condition.
  985  */
  986 void
  987 ieee80211_ht_timeout(struct ieee80211com *ic)
  988 {
  989         IEEE80211_LOCK_ASSERT(ic);
  990 
  991         if ((ic->ic_flags_ext & IEEE80211_FEXT_NONHT_PR) &&
  992             time_after(ticks, ic->ic_lastnonht + IEEE80211_NONHT_PRESENT_AGE)) {
  993 #if 0
  994                 IEEE80211_NOTE(ic, IEEE80211_MSG_11N, ni,
  995                     "%s", "time out non-HT STA present on channel");
  996 #endif
  997                 ic->ic_flags_ext &= ~IEEE80211_FEXT_NONHT_PR;
  998                 htinfo_update(ic);
  999         }
 1000 }
 1001 
 1002 /* unalligned little endian access */     
 1003 #define LE_READ_2(p)                                    \
 1004         ((uint16_t)                                     \
 1005          ((((const uint8_t *)(p))[0]      ) |           \
 1006           (((const uint8_t *)(p))[1] <<  8)))
 1007 
 1008 /*
 1009  * Process an 802.11n HT capabilities ie.
 1010  */
 1011 void
 1012 ieee80211_parse_htcap(struct ieee80211_node *ni, const uint8_t *ie)
 1013 {
 1014         struct ieee80211com *ic = ni->ni_ic;
 1015 
 1016         if (ie[0] == IEEE80211_ELEMID_VENDOR) {
 1017                 /*
 1018                  * Station used Vendor OUI ie to associate;
 1019                  * mark the node so when we respond we'll use
 1020                  * the Vendor OUI's and not the standard ie's.
 1021                  */
 1022                 ni->ni_flags |= IEEE80211_NODE_HTCOMPAT;
 1023                 ie += 4;
 1024         } else
 1025                 ni->ni_flags &= ~IEEE80211_NODE_HTCOMPAT;
 1026 
 1027         ni->ni_htcap = LE_READ_2(ie +
 1028                 __offsetof(struct ieee80211_ie_htcap, hc_cap));
 1029         ni->ni_htparam = ie[__offsetof(struct ieee80211_ie_htcap, hc_param)];
 1030         /* XXX needed or will ieee80211_parse_htinfo always be called? */
 1031         ni->ni_chw = (ni->ni_htcap & IEEE80211_HTCAP_CHWIDTH40) &&
 1032                      (ic->ic_flags_ext & IEEE80211_FEXT_USEHT40) ? 40 : 20;
 1033 }
 1034 
 1035 /*
 1036  * Process an 802.11n HT info ie and update the node state.
 1037  * Note that we handle use this information to identify the
 1038  * correct channel (HT20, HT40+, HT40-, legacy).  The caller
 1039  * is responsible for insuring any required channel change is
 1040  * done (e.g. in sta mode when parsing the contents of a
 1041  * beacon frame).
 1042  */
 1043 void
 1044 ieee80211_parse_htinfo(struct ieee80211_node *ni, const uint8_t *ie)
 1045 {
 1046         struct ieee80211com *ic = ni->ni_ic;
 1047         const struct ieee80211_ie_htinfo *htinfo;
 1048         struct ieee80211_channel *c;
 1049         uint16_t w;
 1050         int htflags, chanflags;
 1051 
 1052         if (ie[0] == IEEE80211_ELEMID_VENDOR)
 1053                 ie += 4;
 1054         htinfo = (const struct ieee80211_ie_htinfo *) ie;
 1055         ni->ni_htctlchan = htinfo->hi_ctrlchannel;
 1056         ni->ni_ht2ndchan = SM(htinfo->hi_byte1, IEEE80211_HTINFO_2NDCHAN);
 1057         w = LE_READ_2(&htinfo->hi_byte2);
 1058         ni->ni_htopmode = SM(w, IEEE80211_HTINFO_OPMODE);
 1059         w = LE_READ_2(&htinfo->hi_byte45);
 1060         ni->ni_htstbc = SM(w, IEEE80211_HTINFO_BASIC_STBCMCS);
 1061         /*
 1062          * Handle 11n channel switch.  Use the received HT ie's to
 1063          * identify the right channel to use.  If we cannot locate it
 1064          * in the channel table then fallback to legacy operation.
 1065          */
 1066         htflags = (ic->ic_flags_ext & IEEE80211_FEXT_HT) ?
 1067             IEEE80211_CHAN_HT20 : 0;
 1068         /* NB: honor operating mode constraint */
 1069         if ((htinfo->hi_byte1 & IEEE80211_HTINFO_TXWIDTH_2040) &&
 1070             (ic->ic_flags_ext & IEEE80211_FEXT_USEHT40)) {
 1071                 if (ni->ni_ht2ndchan == IEEE80211_HTINFO_2NDCHAN_ABOVE)
 1072                         htflags = IEEE80211_CHAN_HT40U;
 1073                 else if (ni->ni_ht2ndchan == IEEE80211_HTINFO_2NDCHAN_BELOW)
 1074                         htflags = IEEE80211_CHAN_HT40D;
 1075         }
 1076         chanflags = (ni->ni_chan->ic_flags &~ IEEE80211_CHAN_HT) | htflags;
 1077         if (chanflags != ni->ni_chan->ic_flags) {
 1078                 c = ieee80211_find_channel(ic, ni->ni_chan->ic_freq, chanflags);
 1079                 if (c == NULL && htflags != IEEE80211_CHAN_HT20) {
 1080                         /*
 1081                          * No HT40 channel entry in our table; fall back
 1082                          * to HT20 operation.  This should not happen.
 1083                          */
 1084                         c = findhtchan(ic, ni->ni_chan, IEEE80211_CHAN_HT20);
 1085                         IEEE80211_NOTE(ni->ni_ic,
 1086                             IEEE80211_MSG_ASSOC | IEEE80211_MSG_11N, ni,
 1087                             "no HT40 channel (freq %u), falling back to HT20",
 1088                             ni->ni_chan->ic_freq);
 1089                         /* XXX stat */
 1090                 }
 1091                 if (c != NULL && c != ni->ni_chan) {
 1092                         IEEE80211_NOTE(ni->ni_ic,
 1093                             IEEE80211_MSG_ASSOC | IEEE80211_MSG_11N, ni,
 1094                             "switch station to HT%d channel %u/0x%x",
 1095                             IEEE80211_IS_CHAN_HT40(c) ? 40 : 20,
 1096                             c->ic_freq, c->ic_flags);
 1097                         ni->ni_chan = c;
 1098                 }
 1099                 /* NB: caller responsible for forcing any channel change */
 1100         }
 1101         /* update node's tx channel width */
 1102         ni->ni_chw = IEEE80211_IS_CHAN_HT40(ni->ni_chan)? 40 : 20;
 1103 }
 1104 
 1105 /*
 1106  * Install received HT rate set by parsing the HT cap ie.
 1107  */
 1108 int
 1109 ieee80211_setup_htrates(struct ieee80211_node *ni, const uint8_t *ie, int flags)
 1110 {
 1111         struct ieee80211com *ic = ni->ni_ic;
 1112         const struct ieee80211_ie_htcap *htcap;
 1113         struct ieee80211_htrateset *rs;
 1114         int i;
 1115 
 1116         rs = &ni->ni_htrates;
 1117         memset(rs, 0, sizeof(*rs));
 1118         if (ie != NULL) {
 1119                 if (ie[0] == IEEE80211_ELEMID_VENDOR)
 1120                         ie += 4;
 1121                 htcap = (const struct ieee80211_ie_htcap *) ie;
 1122                 for (i = 0; i < IEEE80211_HTRATE_MAXSIZE; i++) {
 1123                         if (isclr(htcap->hc_mcsset, i))
 1124                                 continue;
 1125                         if (rs->rs_nrates == IEEE80211_HTRATE_MAXSIZE) {
 1126                                 IEEE80211_NOTE(ic,
 1127                                     IEEE80211_MSG_XRATE | IEEE80211_MSG_11N, ni,
 1128                                     "WARNING, HT rate set too large; only "
 1129                                     "using %u rates", IEEE80211_HTRATE_MAXSIZE);
 1130                                 ic->ic_stats.is_rx_rstoobig++;
 1131                                 break;
 1132                         }
 1133                         rs->rs_rates[rs->rs_nrates++] = i;
 1134                 }
 1135         }
 1136         return ieee80211_fix_rate(ni, (struct ieee80211_rateset *) rs, flags);
 1137 }
 1138 
 1139 /*
 1140  * Mark rates in a node's HT rate set as basic according
 1141  * to the information in the supplied HT info ie.
 1142  */
 1143 void
 1144 ieee80211_setup_basic_htrates(struct ieee80211_node *ni, const uint8_t *ie)
 1145 {
 1146         const struct ieee80211_ie_htinfo *htinfo;
 1147         struct ieee80211_htrateset *rs;
 1148         int i, j;
 1149 
 1150         if (ie[0] == IEEE80211_ELEMID_VENDOR)
 1151                 ie += 4;
 1152         htinfo = (const struct ieee80211_ie_htinfo *) ie;
 1153         rs = &ni->ni_htrates;
 1154         if (rs->rs_nrates == 0) {
 1155                 IEEE80211_NOTE(ni->ni_ic,
 1156                     IEEE80211_MSG_XRATE | IEEE80211_MSG_11N, ni,
 1157                     "%s", "WARNING, empty HT rate set");
 1158                 return;
 1159         }
 1160         for (i = 0; i < IEEE80211_HTRATE_MAXSIZE; i++) {
 1161                 if (isclr(htinfo->hi_basicmcsset, i))
 1162                         continue;
 1163                 for (j = 0; j < rs->rs_nrates; j++)
 1164                         if ((rs->rs_rates[j] & IEEE80211_RATE_VAL) == i)
 1165                                 rs->rs_rates[j] |= IEEE80211_RATE_BASIC;
 1166         }
 1167 }
 1168 
 1169 static void
 1170 addba_timeout(void *arg)
 1171 {
 1172         struct ieee80211_tx_ampdu *tap = arg;
 1173 
 1174         /* XXX ? */
 1175         tap->txa_flags &= ~IEEE80211_AGGR_XCHGPEND;
 1176         tap->txa_attempts++;
 1177 }
 1178 
 1179 static void
 1180 addba_start_timeout(struct ieee80211_tx_ampdu *tap)
 1181 {
 1182         /* XXX use CALLOUT_PENDING instead? */
 1183         callout_reset(&tap->txa_timer, IEEE80211_AGGR_TIMEOUT,
 1184             addba_timeout, tap);
 1185         tap->txa_flags |= IEEE80211_AGGR_XCHGPEND;
 1186         tap->txa_lastrequest = ticks;
 1187 }
 1188 
 1189 static void
 1190 addba_stop_timeout(struct ieee80211_tx_ampdu *tap)
 1191 {
 1192         /* XXX use CALLOUT_PENDING instead? */
 1193         if (tap->txa_flags & IEEE80211_AGGR_XCHGPEND) {
 1194                 callout_stop(&tap->txa_timer);
 1195                 tap->txa_flags &= ~IEEE80211_AGGR_XCHGPEND;
 1196         }
 1197 }
 1198 
 1199 /*
 1200  * Default method for requesting A-MPDU tx aggregation.
 1201  * We setup the specified state block and start a timer
 1202  * to wait for an ADDBA response frame.
 1203  */
 1204 static int
 1205 ieee80211_addba_request(struct ieee80211_node *ni,
 1206         struct ieee80211_tx_ampdu *tap,
 1207         int dialogtoken, int baparamset, int batimeout)
 1208 {
 1209         int bufsiz;
 1210 
 1211         /* XXX locking */
 1212         tap->txa_token = dialogtoken;
 1213         tap->txa_flags |= IEEE80211_AGGR_IMMEDIATE;
 1214         tap->txa_start = tap->txa_seqstart = 0;
 1215         bufsiz = MS(baparamset, IEEE80211_BAPS_BUFSIZ);
 1216         tap->txa_wnd = (bufsiz == 0) ?
 1217             IEEE80211_AGGR_BAWMAX : min(bufsiz, IEEE80211_AGGR_BAWMAX);
 1218         addba_start_timeout(tap);
 1219         return 1;
 1220 }
 1221 
 1222 /*
 1223  * Default method for processing an A-MPDU tx aggregation
 1224  * response.  We shutdown any pending timer and update the
 1225  * state block according to the reply.
 1226  */
 1227 static int
 1228 ieee80211_addba_response(struct ieee80211_node *ni,
 1229         struct ieee80211_tx_ampdu *tap,
 1230         int status, int baparamset, int batimeout)
 1231 {
 1232         int bufsiz;
 1233 
 1234         /* XXX locking */
 1235         addba_stop_timeout(tap);
 1236         if (status == IEEE80211_STATUS_SUCCESS) {
 1237                 bufsiz = MS(baparamset, IEEE80211_BAPS_BUFSIZ);
 1238                 /* XXX override our request? */
 1239                 tap->txa_wnd = (bufsiz == 0) ?
 1240                     IEEE80211_AGGR_BAWMAX : min(bufsiz, IEEE80211_AGGR_BAWMAX);
 1241                 tap->txa_flags |= IEEE80211_AGGR_RUNNING;
 1242         } else {
 1243                 /* mark tid so we don't try again */
 1244                 tap->txa_flags |= IEEE80211_AGGR_NAK;
 1245         }
 1246         return 1;
 1247 }
 1248 
 1249 /*
 1250  * Default method for stopping A-MPDU tx aggregation.
 1251  * Any timer is cleared and we drain any pending frames.
 1252  */
 1253 static void
 1254 ieee80211_addba_stop(struct ieee80211_node *ni, struct ieee80211_tx_ampdu *tap)
 1255 {
 1256         /* XXX locking */
 1257         addba_stop_timeout(tap);
 1258         if (tap->txa_flags & IEEE80211_AGGR_RUNNING) {
 1259                 /* clear aggregation queue */
 1260                 ieee80211_drain_ifq(&tap->txa_q);
 1261                 tap->txa_flags &= ~IEEE80211_AGGR_RUNNING;
 1262         }
 1263         tap->txa_attempts = 0;
 1264 }
 1265 
 1266 /*
 1267  * Process a received action frame using the default aggregation
 1268  * policy.  We intercept ADDBA-related frames and use them to
 1269  * update our aggregation state.  All other frames are passed up
 1270  * for processing by ieee80211_recv_action.
 1271  */
 1272 static void
 1273 ieee80211_aggr_recv_action(struct ieee80211_node *ni,
 1274         const uint8_t *frm, const uint8_t *efrm)
 1275 {
 1276         struct ieee80211com *ic = ni->ni_ic;
 1277         const struct ieee80211_action *ia;
 1278         struct ieee80211_rx_ampdu *rap;
 1279         struct ieee80211_tx_ampdu *tap;
 1280         uint8_t dialogtoken;
 1281         uint16_t baparamset, batimeout, baseqctl, code;
 1282         uint16_t args[4];
 1283         int tid, ac, bufsiz;
 1284 
 1285         ia = (const struct ieee80211_action *) frm;
 1286         switch (ia->ia_category) {
 1287         case IEEE80211_ACTION_CAT_BA:
 1288                 switch (ia->ia_action) {
 1289                 case IEEE80211_ACTION_BA_ADDBA_REQUEST:
 1290                         dialogtoken = frm[2];
 1291                         baparamset = LE_READ_2(frm+3);
 1292                         batimeout = LE_READ_2(frm+5);
 1293                         baseqctl = LE_READ_2(frm+7);
 1294 
 1295                         tid = MS(baparamset, IEEE80211_BAPS_TID);
 1296                         bufsiz = MS(baparamset, IEEE80211_BAPS_BUFSIZ);
 1297 
 1298                         IEEE80211_NOTE(ic,
 1299                             IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
 1300                             "recv ADDBA request: dialogtoken %u "
 1301                             "baparamset 0x%x (tid %d bufsiz %d) batimeout %d "
 1302                             "baseqctl %d:%d",
 1303                             dialogtoken, baparamset, tid, bufsiz, batimeout,
 1304                             MS(baseqctl, IEEE80211_BASEQ_START),
 1305                             MS(baseqctl, IEEE80211_BASEQ_FRAG));
 1306 
 1307                         rap = &ni->ni_rx_ampdu[tid];
 1308 
 1309                         /* Send ADDBA response */
 1310                         args[0] = dialogtoken;
 1311                         /*
 1312                          * NB: We ack only if the sta associated with HT and
 1313                          * the ap is configured to do AMPDU rx (the latter
 1314                          * violates the 11n spec and is mostly for testing).
 1315                          */
 1316                         if ((ni->ni_flags & IEEE80211_NODE_AMPDU_RX) &&
 1317                             (ic->ic_flags_ext & IEEE80211_FEXT_AMPDU_RX)) {
 1318                                 ampdu_rx_start(rap, bufsiz,
 1319                                     MS(baseqctl, IEEE80211_BASEQ_START));
 1320 
 1321                                 args[1] = IEEE80211_STATUS_SUCCESS;
 1322                         } else {
 1323                                 IEEE80211_NOTE(ic,
 1324                                     IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
 1325                                     ni, "reject ADDBA request: %s",
 1326                                     ni->ni_flags & IEEE80211_NODE_AMPDU_RX ?
 1327                                        "administratively disabled" :
 1328                                        "not negotiated for station");
 1329                                 ic->ic_stats.is_addba_reject++;
 1330                                 args[1] = IEEE80211_STATUS_UNSPECIFIED;
 1331                         }
 1332                         /* XXX honor rap flags? */
 1333                         args[2] = IEEE80211_BAPS_POLICY_IMMEDIATE
 1334                                 | SM(tid, IEEE80211_BAPS_TID)
 1335                                 | SM(rap->rxa_wnd, IEEE80211_BAPS_BUFSIZ)
 1336                                 ;
 1337                         args[3] = 0;
 1338                         ic->ic_send_action(ni, IEEE80211_ACTION_CAT_BA,
 1339                                 IEEE80211_ACTION_BA_ADDBA_RESPONSE, args);
 1340                         return;
 1341 
 1342                 case IEEE80211_ACTION_BA_ADDBA_RESPONSE:
 1343                         dialogtoken = frm[2];
 1344                         code = LE_READ_2(frm+3);
 1345                         baparamset = LE_READ_2(frm+5);
 1346                         tid = MS(baparamset, IEEE80211_BAPS_TID);
 1347                         bufsiz = MS(baparamset, IEEE80211_BAPS_BUFSIZ);
 1348                         batimeout = LE_READ_2(frm+7);
 1349 
 1350                         ac = TID_TO_WME_AC(tid);
 1351                         tap = &ni->ni_tx_ampdu[ac];
 1352                         if ((tap->txa_flags & IEEE80211_AGGR_XCHGPEND) == 0) {
 1353                                 IEEE80211_DISCARD_MAC(ic,
 1354                                     IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
 1355                                     ni->ni_macaddr, "ADDBA response",
 1356                                     "no pending ADDBA, tid %d dialogtoken %u "
 1357                                     "code %d", tid, dialogtoken, code);
 1358                                 ic->ic_stats.is_addba_norequest++;
 1359                                 return;
 1360                         }
 1361                         if (dialogtoken != tap->txa_token) {
 1362                                 IEEE80211_DISCARD_MAC(ic,
 1363                                     IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
 1364                                     ni->ni_macaddr, "ADDBA response",
 1365                                     "dialogtoken mismatch: waiting for %d, "
 1366                                     "received %d, tid %d code %d",
 1367                                     tap->txa_token, dialogtoken, tid, code);
 1368                                 ic->ic_stats.is_addba_badtoken++;
 1369                                 return;
 1370                         }
 1371 
 1372                         IEEE80211_NOTE(ic,
 1373                             IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
 1374                             "recv ADDBA response: dialogtoken %u code %d "
 1375                             "baparamset 0x%x (tid %d bufsiz %d) batimeout %d",
 1376                             dialogtoken, code, baparamset, tid, bufsiz,
 1377                             batimeout);
 1378                         ic->ic_addba_response(ni, tap,
 1379                                 code, baparamset, batimeout);
 1380                         return;
 1381 
 1382                 case IEEE80211_ACTION_BA_DELBA:
 1383                         baparamset = LE_READ_2(frm+2);
 1384                         code = LE_READ_2(frm+4);
 1385 
 1386                         tid = MS(baparamset, IEEE80211_DELBAPS_TID);
 1387 
 1388                         IEEE80211_NOTE(ic,
 1389                             IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
 1390                             "recv DELBA: baparamset 0x%x (tid %d initiator %d) "
 1391                             "code %d", baparamset, tid,
 1392                             MS(baparamset, IEEE80211_DELBAPS_INIT), code);
 1393 
 1394                         if ((baparamset & IEEE80211_DELBAPS_INIT) == 0) {
 1395                                 ac = TID_TO_WME_AC(tid);
 1396                                 tap = &ni->ni_tx_ampdu[ac];
 1397                                 ic->ic_addba_stop(ni, tap);
 1398                         } else {
 1399                                 rap = &ni->ni_rx_ampdu[tid];
 1400                                 ampdu_rx_stop(rap);
 1401                         }
 1402                         return;
 1403                 }
 1404                 break;
 1405         }
 1406         ieee80211_recv_action(ni, frm, efrm);
 1407 }
 1408 
 1409 /*
 1410  * Process a received 802.11n action frame.
 1411  * Aggregation-related frames are assumed to be handled
 1412  * already; we handle any other frames we can, otherwise
 1413  * complain about being unsupported (with debugging).
 1414  */
 1415 void
 1416 ieee80211_recv_action(struct ieee80211_node *ni,
 1417         const uint8_t *frm, const uint8_t *efrm)
 1418 {
 1419         struct ieee80211com *ic = ni->ni_ic;
 1420         const struct ieee80211_action *ia;
 1421         int chw;
 1422 
 1423         ia = (const struct ieee80211_action *) frm;
 1424         switch (ia->ia_category) {
 1425         case IEEE80211_ACTION_CAT_BA:
 1426                 IEEE80211_NOTE(ic,
 1427                     IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
 1428                     "%s: BA action %d not implemented", __func__,
 1429                     ia->ia_action);
 1430                 ic->ic_stats.is_rx_mgtdiscard++;
 1431                 break;
 1432         case IEEE80211_ACTION_CAT_HT:
 1433                 switch (ia->ia_action) {
 1434                 case IEEE80211_ACTION_HT_TXCHWIDTH:
 1435                         chw = frm[2] == IEEE80211_A_HT_TXCHWIDTH_2040 ? 40 : 20;
 1436                         if (chw != ni->ni_chw) {
 1437                                 ni->ni_chw = chw;
 1438                                 ni->ni_flags |= IEEE80211_NODE_CHWUPDATE;
 1439                         }
 1440                         IEEE80211_NOTE(ic,
 1441                             IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
 1442                             "%s: HT txchwidth, width %d (%s)",
 1443                             __func__, chw,
 1444                             ni->ni_flags & IEEE80211_NODE_CHWUPDATE ?
 1445                                 "new" : "no change");
 1446                         break;
 1447                 case IEEE80211_ACTION_HT_MIMOPWRSAVE:
 1448                         IEEE80211_NOTE(ic,
 1449                             IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
 1450                             "%s: HT MIMO PS", __func__);
 1451                         break;
 1452                 default:
 1453                         IEEE80211_NOTE(ic,
 1454                            IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
 1455                            "%s: HT action %d not implemented", __func__,
 1456                            ia->ia_action);
 1457                         ic->ic_stats.is_rx_mgtdiscard++;
 1458                         break;
 1459                 }
 1460                 break;
 1461         default:
 1462                 IEEE80211_NOTE(ic,
 1463                     IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
 1464                     "%s: category %d not implemented", __func__,
 1465                     ia->ia_category);
 1466                 ic->ic_stats.is_rx_mgtdiscard++;
 1467                 break;
 1468         }
 1469 }
 1470 
 1471 /*
 1472  * Transmit processing.
 1473  */
 1474 
 1475 /*
 1476  * Request A-MPDU tx aggregation.  Setup local state and
 1477  * issue an ADDBA request.  BA use will only happen after
 1478  * the other end replies with ADDBA response.
 1479  */
 1480 int
 1481 ieee80211_ampdu_request(struct ieee80211_node *ni,
 1482         struct ieee80211_tx_ampdu *tap)
 1483 {
 1484         struct ieee80211com *ic = ni->ni_ic;
 1485         uint16_t args[4];
 1486         int tid, dialogtoken;
 1487         static int tokens = 0;  /* XXX */
 1488 
 1489         /* XXX locking */
 1490         if ((tap->txa_flags & IEEE80211_AGGR_SETUP) == 0) {
 1491                 /* do deferred setup of state */
 1492                 IEEE80211_TAPQ_INIT(tap);
 1493                 callout_init(&tap->txa_timer, CALLOUT_MPSAFE);
 1494                 tap->txa_flags |= IEEE80211_AGGR_SETUP;
 1495         }
 1496         if (tap->txa_attempts >= IEEE80211_AGGR_MAXTRIES &&
 1497             (ticks - tap->txa_lastrequest) < IEEE80211_AGGR_MINRETRY) {
 1498                 /*
 1499                  * Don't retry too often; IEEE80211_AGGR_MINRETRY
 1500                  * defines the minimum interval we'll retry after
 1501                  * IEEE80211_AGGR_MAXTRIES failed attempts to
 1502                  * negotiate use.
 1503                  */
 1504                 return 0;
 1505         }
 1506         /* XXX hack for not doing proper locking */
 1507         tap->txa_flags &= ~IEEE80211_AGGR_NAK;
 1508 
 1509         dialogtoken = (tokens+1) % 63;          /* XXX */
 1510 
 1511         tid = WME_AC_TO_TID(tap->txa_ac);
 1512         args[0] = dialogtoken;
 1513         args[1] = IEEE80211_BAPS_POLICY_IMMEDIATE
 1514                 | SM(tid, IEEE80211_BAPS_TID)
 1515                 | SM(IEEE80211_AGGR_BAWMAX, IEEE80211_BAPS_BUFSIZ)
 1516                 ;
 1517         args[2] = 0;    /* batimeout */
 1518         args[3] = SM(0, IEEE80211_BASEQ_START)
 1519                 | SM(0, IEEE80211_BASEQ_FRAG)
 1520                 ;
 1521         /* NB: do first so there's no race against reply */
 1522         if (!ic->ic_addba_request(ni, tap, dialogtoken, args[1], args[2])) {
 1523                 /* unable to setup state, don't make request */
 1524                 IEEE80211_NOTE(ni->ni_ic, IEEE80211_MSG_11N,
 1525                     ni, "%s: could not setup BA stream for AC %d",
 1526                     __func__, tap->txa_ac);
 1527                 /* defer next try so we don't slam the driver with requests */
 1528                 tap->txa_attempts = IEEE80211_AGGR_MAXTRIES;
 1529                 tap->txa_lastrequest = ticks;
 1530                 return 0;
 1531         }
 1532         tokens = dialogtoken;                   /* allocate token */
 1533         return ic->ic_send_action(ni, IEEE80211_ACTION_CAT_BA,
 1534                 IEEE80211_ACTION_BA_ADDBA_REQUEST, args);
 1535 }
 1536 
 1537 /*
 1538  * Terminate an AMPDU tx stream.  State is reclaimed
 1539  * and the peer notified with a DelBA Action frame.
 1540  */
 1541 void
 1542 ieee80211_ampdu_stop(struct ieee80211_node *ni, struct ieee80211_tx_ampdu *tap)
 1543 {
 1544         struct ieee80211com *ic = ni->ni_ic;
 1545         uint16_t args[4];
 1546 
 1547         /* XXX locking */
 1548         if (IEEE80211_AMPDU_RUNNING(tap)) {
 1549                 IEEE80211_NOTE(ic, IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
 1550                     ni, "%s: stop BA stream for AC %d", __func__, tap->txa_ac);
 1551                 ic->ic_stats.is_ampdu_stop++;
 1552 
 1553                 ic->ic_addba_stop(ni, tap);
 1554                 args[0] = WME_AC_TO_TID(tap->txa_ac);
 1555                 args[1] = IEEE80211_DELBAPS_INIT;
 1556                 args[2] = 1;                            /* XXX reason code */
 1557                 ieee80211_send_action(ni, IEEE80211_ACTION_CAT_BA,
 1558                         IEEE80211_ACTION_BA_DELBA, args);
 1559         } else {
 1560                 IEEE80211_NOTE(ic, IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
 1561                     ni, "%s: BA stream for AC %d not running",
 1562                     __func__, tap->txa_ac);
 1563                 ic->ic_stats.is_ampdu_stop_failed++;
 1564         }
 1565 }
 1566 
 1567 /*
 1568  * Transmit a BAR frame to the specified node.  The
 1569  * BAR contents are drawn from the supplied aggregation
 1570  * state associated with the node.
 1571  */
 1572 int
 1573 ieee80211_send_bar(struct ieee80211_node *ni,
 1574         const struct ieee80211_tx_ampdu *tap)
 1575 {
 1576 #define senderr(_x, _v) do { ic->ic_stats._v++; ret = _x; goto bad; } while (0)
 1577 #define ADDSHORT(frm, v) do {                   \
 1578         frm[0] = (v) & 0xff;                    \
 1579         frm[1] = (v) >> 8;                      \
 1580         frm += 2;                               \
 1581 } while (0)
 1582         struct ieee80211com *ic = ni->ni_ic;
 1583         struct ifnet *ifp = ic->ic_ifp;
 1584         struct ieee80211_frame_min *wh;
 1585         struct mbuf *m;
 1586         uint8_t *frm;
 1587         uint16_t barctl, barseqctl;
 1588         int tid, ret;
 1589 
 1590         ieee80211_ref_node(ni);
 1591 
 1592         m = ieee80211_getmgtframe(&frm,
 1593                 ic->ic_headroom + sizeof(struct ieee80211_frame_min),
 1594                 sizeof(struct ieee80211_ba_request)
 1595         );
 1596         if (m == NULL)
 1597                 senderr(ENOMEM, is_tx_nobuf);
 1598 
 1599         wh = mtod(m, struct ieee80211_frame_min *);
 1600         wh->i_fc[0] = IEEE80211_FC0_VERSION_0 |
 1601                 IEEE80211_FC0_TYPE_CTL | IEEE80211_FC0_SUBTYPE_BAR;
 1602         wh->i_fc[1] = 0;
 1603         IEEE80211_ADDR_COPY(wh->i_addr1, ni->ni_macaddr);
 1604         IEEE80211_ADDR_COPY(wh->i_addr2, ic->ic_myaddr);
 1605 
 1606         tid = WME_AC_TO_TID(tap->txa_ac);
 1607         barctl  = (tap->txa_flags & IEEE80211_AGGR_IMMEDIATE ?
 1608                         IEEE80211_BAPS_POLICY_IMMEDIATE :
 1609                         IEEE80211_BAPS_POLICY_DELAYED)
 1610                 | SM(tid, IEEE80211_BAPS_TID)
 1611                 | SM(tap->txa_wnd, IEEE80211_BAPS_BUFSIZ)
 1612                 ;
 1613         barseqctl = SM(tap->txa_start, IEEE80211_BASEQ_START)
 1614                 | SM(0, IEEE80211_BASEQ_FRAG)
 1615                 ;
 1616         ADDSHORT(frm, barctl);
 1617         ADDSHORT(frm, barseqctl);
 1618         m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
 1619 
 1620         IEEE80211_NODE_STAT(ni, tx_mgmt);       /* XXX tx_ctl? */
 1621 
 1622         IEEE80211_NOTE(ic, IEEE80211_MSG_DEBUG | IEEE80211_MSG_DUMPPKTS,
 1623             ni, "send bar frame (tid %u start %u) on channel %u",
 1624             tid, tap->txa_start, ieee80211_chan2ieee(ic, ic->ic_curchan));
 1625 
 1626         m->m_pkthdr.rcvif = (void *)ni;
 1627         IF_ENQUEUE(&ic->ic_mgtq, m);            /* cheat */
 1628         if_start(ifp);
 1629 
 1630         return 0;
 1631 bad:
 1632         ieee80211_free_node(ni);
 1633         return ret;
 1634 #undef ADDSHORT
 1635 #undef senderr
 1636 }
 1637 
 1638 /*
 1639  * Send an action management frame.  The arguments are stuff
 1640  * into a frame without inspection; the caller is assumed to
 1641  * prepare them carefully (e.g. based on the aggregation state).
 1642  */
 1643 int
 1644 ieee80211_send_action(struct ieee80211_node *ni,
 1645         int category, int action, uint16_t args[4])
 1646 {
 1647 #define senderr(_x, _v) do { ic->ic_stats._v++; ret = _x; goto bad; } while (0)
 1648 #define ADDSHORT(frm, v) do {                   \
 1649         frm[0] = (v) & 0xff;                    \
 1650         frm[1] = (v) >> 8;                      \
 1651         frm += 2;                               \
 1652 } while (0)
 1653         struct ieee80211com *ic = ni->ni_ic;
 1654         struct mbuf *m;
 1655         uint8_t *frm;
 1656         uint16_t baparamset;
 1657         int ret;
 1658 
 1659         KASSERT(ni != NULL, ("null node"));
 1660 
 1661         /*
 1662          * Hold a reference on the node so it doesn't go away until after
 1663          * the xmit is complete all the way in the driver.  On error we
 1664          * will remove our reference.
 1665          */
 1666         IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
 1667                 "ieee80211_ref_node (%s:%u) %p<%s> refcnt %d\n",
 1668                 __func__, __LINE__,
 1669                 ni, ether_sprintf(ni->ni_macaddr),
 1670                 ieee80211_node_refcnt(ni)+1);
 1671         ieee80211_ref_node(ni);
 1672 
 1673         m = ieee80211_getmgtframe(&frm,
 1674                 ic->ic_headroom + sizeof(struct ieee80211_frame),
 1675                   sizeof(uint16_t)      /* action+category */
 1676                 /* XXX may action payload */
 1677                 + sizeof(struct ieee80211_action_ba_addbaresponse)
 1678         );
 1679         if (m == NULL)
 1680                 senderr(ENOMEM, is_tx_nobuf);
 1681 
 1682         *frm++ = category;
 1683         *frm++ = action;
 1684         switch (category) {
 1685         case IEEE80211_ACTION_CAT_BA:
 1686                 switch (action) {
 1687                 case IEEE80211_ACTION_BA_ADDBA_REQUEST:
 1688                         IEEE80211_NOTE(ic,
 1689                             IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
 1690                             "send ADDBA request: dialogtoken %d "
 1691                             "baparamset 0x%x (tid %d) batimeout 0x%x baseqctl 0x%x",
 1692                             args[0], args[1], MS(args[1], IEEE80211_BAPS_TID),
 1693                             args[2], args[3]);
 1694 
 1695                         *frm++ = args[0];       /* dialog token */
 1696                         ADDSHORT(frm, args[1]); /* baparamset */
 1697                         ADDSHORT(frm, args[2]); /* batimeout */
 1698                         ADDSHORT(frm, args[3]); /* baseqctl */
 1699                         break;
 1700                 case IEEE80211_ACTION_BA_ADDBA_RESPONSE:
 1701                         IEEE80211_NOTE(ic,
 1702                             IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
 1703                             "send ADDBA response: dialogtoken %d status %d "
 1704                             "baparamset 0x%x (tid %d) batimeout %d",
 1705                             args[0], args[1], args[2],
 1706                             MS(args[2], IEEE80211_BAPS_TID), args[3]);
 1707 
 1708                         *frm++ = args[0];       /* dialog token */
 1709                         ADDSHORT(frm, args[1]); /* statuscode */
 1710                         ADDSHORT(frm, args[2]); /* baparamset */
 1711                         ADDSHORT(frm, args[3]); /* batimeout */
 1712                         break;
 1713                 case IEEE80211_ACTION_BA_DELBA:
 1714                         /* XXX */
 1715                         baparamset = SM(args[0], IEEE80211_DELBAPS_TID)
 1716                                    | SM(args[1], IEEE80211_DELBAPS_INIT)
 1717                                    ;
 1718                         ADDSHORT(frm, baparamset);
 1719                         ADDSHORT(frm, args[2]); /* reason code */
 1720 
 1721                         IEEE80211_NOTE(ic,
 1722                             IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
 1723                             "send DELBA action: tid %d, initiator %d reason %d",
 1724                             args[0], args[1], args[2]);
 1725                         break;
 1726                 default:
 1727                         goto badaction;
 1728                 }
 1729                 break;
 1730         case IEEE80211_ACTION_CAT_HT:
 1731                 switch (action) {
 1732                 case IEEE80211_ACTION_HT_TXCHWIDTH:
 1733                         IEEE80211_NOTE(ic,
 1734                             IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
 1735                             ni, "send HT txchwidth: width %d",
 1736                             IEEE80211_IS_CHAN_HT40(ic->ic_bsschan) ? 40 : 20
 1737                         );
 1738                         *frm++ = IEEE80211_IS_CHAN_HT40(ic->ic_bsschan) ? 
 1739                                 IEEE80211_A_HT_TXCHWIDTH_2040 :
 1740                                 IEEE80211_A_HT_TXCHWIDTH_20;
 1741                         break;
 1742                 default:
 1743                         goto badaction;
 1744                 }
 1745                 break;
 1746         default:
 1747         badaction:
 1748                 IEEE80211_NOTE(ic,
 1749                     IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
 1750                     "%s: unsupported category %d action %d", __func__,
 1751                     category, action);
 1752                 senderr(EINVAL, is_tx_unknownmgt);
 1753                 /* NOTREACHED */
 1754         }
 1755         m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
 1756 
 1757         ret = ieee80211_mgmt_output(ic, ni, m, IEEE80211_FC0_SUBTYPE_ACTION);
 1758         if (ret != 0)
 1759                 goto bad;
 1760         return 0;
 1761 bad:
 1762         ieee80211_free_node(ni);
 1763         return ret;
 1764 #undef ADDSHORT
 1765 #undef senderr
 1766 }
 1767 
 1768 /*
 1769  * Construct the MCS bit mask for inclusion
 1770  * in an HT information element.
 1771  */
 1772 static void 
 1773 ieee80211_set_htrates(uint8_t *frm, const struct ieee80211_htrateset *rs)
 1774 {
 1775         int i;
 1776 
 1777         for (i = 0; i < rs->rs_nrates; i++) {
 1778                 int r = rs->rs_rates[i] & IEEE80211_RATE_VAL;
 1779                 if (r < IEEE80211_HTRATE_MAXSIZE) {     /* XXX? */
 1780                         /* NB: this assumes a particular implementation */
 1781                         setbit(frm, r);
 1782                 }
 1783         }
 1784 }
 1785 
 1786 /*
 1787  * Add body of an HTCAP information element.
 1788  */
 1789 static uint8_t *
 1790 ieee80211_add_htcap_body(uint8_t *frm, struct ieee80211_node *ni)
 1791 {
 1792 #define ADDSHORT(frm, v) do {                   \
 1793         frm[0] = (v) & 0xff;                    \
 1794         frm[1] = (v) >> 8;                      \
 1795         frm += 2;                               \
 1796 } while (0)
 1797         struct ieee80211com *ic = ni->ni_ic;
 1798         uint16_t caps;
 1799         int rxmax, density;
 1800 
 1801         /* HT capabilities */
 1802         caps = ic->ic_htcaps & 0xffff;
 1803         /*
 1804          * Note channel width depends on whether we are operating as
 1805          * a sta or not.  When operating as a sta we are generating
 1806          * a request based on our desired configuration.  Otherwise
 1807          * we are operational and the channel attributes identify
 1808          * how we've been setup (which might be different if a fixed
 1809          * channel is specified).
 1810          */
 1811         if (ic->ic_opmode == IEEE80211_M_STA) {
 1812                 /* override 20/40 use based on config */
 1813                 if (ic->ic_flags_ext & IEEE80211_FEXT_USEHT40)
 1814                         caps |= IEEE80211_HTCAP_CHWIDTH40;
 1815                 else
 1816                         caps &= ~IEEE80211_HTCAP_CHWIDTH40;
 1817                 /* use advertised setting (XXX locally constraint) */
 1818                 rxmax = MS(ni->ni_htparam, IEEE80211_HTCAP_MAXRXAMPDU);
 1819                 density = MS(ni->ni_htparam, IEEE80211_HTCAP_MPDUDENSITY);
 1820         } else {
 1821                 /* override 20/40 use based on current channel */
 1822                 if (IEEE80211_IS_CHAN_HT40(ic->ic_bsschan))
 1823                         caps |= IEEE80211_HTCAP_CHWIDTH40;
 1824                 else
 1825                         caps &= ~IEEE80211_HTCAP_CHWIDTH40;
 1826                 rxmax = ic->ic_ampdu_rxmax;
 1827                 density = ic->ic_ampdu_density;
 1828         }
 1829         /* adjust short GI based on channel and config */
 1830         if ((ic->ic_flags_ext & IEEE80211_FEXT_SHORTGI20) == 0)
 1831                 caps &= ~IEEE80211_HTCAP_SHORTGI20;
 1832         if ((ic->ic_flags_ext & IEEE80211_FEXT_SHORTGI40) == 0 ||
 1833             (caps & IEEE80211_HTCAP_CHWIDTH40) == 0)
 1834                 caps &= ~IEEE80211_HTCAP_SHORTGI40;
 1835         ADDSHORT(frm, caps);
 1836 
 1837         /* HT parameters */
 1838         *frm = SM(rxmax, IEEE80211_HTCAP_MAXRXAMPDU)
 1839              | SM(density, IEEE80211_HTCAP_MPDUDENSITY)
 1840              ;
 1841         frm++;
 1842 
 1843         /* pre-zero remainder of ie */
 1844         memset(frm, 0, sizeof(struct ieee80211_ie_htcap) - 
 1845                 __offsetof(struct ieee80211_ie_htcap, hc_mcsset));
 1846 
 1847         /* supported MCS set */
 1848         /*
 1849          * XXX it would better to get the rate set from ni_htrates
 1850          * so we can restrict it but for sta mode ni_htrates isn't
 1851          * setup when we're called to form an AssocReq frame so for
 1852          * now we're restricted to the default HT rate set.
 1853          */
 1854         ieee80211_set_htrates(frm, &ieee80211_rateset_11n);
 1855 
 1856         frm += sizeof(struct ieee80211_ie_htcap) -
 1857                 __offsetof(struct ieee80211_ie_htcap, hc_mcsset);
 1858         return frm;
 1859 #undef ADDSHORT
 1860 }
 1861 
 1862 /*
 1863  * Add 802.11n HT capabilities information element
 1864  */
 1865 uint8_t *
 1866 ieee80211_add_htcap(uint8_t *frm, struct ieee80211_node *ni)
 1867 {
 1868         frm[0] = IEEE80211_ELEMID_HTCAP;
 1869         frm[1] = sizeof(struct ieee80211_ie_htcap) - 2;
 1870         return ieee80211_add_htcap_body(frm + 2, ni);
 1871 }
 1872 
 1873 /*
 1874  * Add Broadcom OUI wrapped standard HTCAP ie; this is
 1875  * used for compatibility w/ pre-draft implementations.
 1876  */
 1877 uint8_t *
 1878 ieee80211_add_htcap_vendor(uint8_t *frm, struct ieee80211_node *ni)
 1879 {
 1880         frm[0] = IEEE80211_ELEMID_VENDOR;
 1881         frm[1] = 4 + sizeof(struct ieee80211_ie_htcap) - 2;
 1882         frm[2] = (BCM_OUI >> 0) & 0xff;
 1883         frm[3] = (BCM_OUI >> 8) & 0xff;
 1884         frm[4] = (BCM_OUI >> 16) & 0xff;
 1885         frm[5] = BCM_OUI_HTCAP;
 1886         return ieee80211_add_htcap_body(frm + 6, ni);
 1887 }
 1888 
 1889 /*
 1890  * Construct the MCS bit mask of basic rates
 1891  * for inclusion in an HT information element.
 1892  */
 1893 static void
 1894 ieee80211_set_basic_htrates(uint8_t *frm, const struct ieee80211_htrateset *rs)
 1895 {
 1896         int i;
 1897 
 1898         for (i = 0; i < rs->rs_nrates; i++) {
 1899                 int r = rs->rs_rates[i] & IEEE80211_RATE_VAL;
 1900                 if ((rs->rs_rates[i] & IEEE80211_RATE_BASIC) &&
 1901                     r < IEEE80211_HTRATE_MAXSIZE) {
 1902                         /* NB: this assumes a particular implementation */
 1903                         setbit(frm, r);
 1904                 }
 1905         }
 1906 }
 1907 
 1908 /*
 1909  * Update the HTINFO ie for a beacon frame.
 1910  */
 1911 void
 1912 ieee80211_ht_update_beacon(struct ieee80211com *ic,
 1913         struct ieee80211_beacon_offsets *bo)
 1914 {
 1915 #define PROTMODE        (IEEE80211_HTINFO_OPMODE|IEEE80211_HTINFO_NONHT_PRESENT)
 1916         struct ieee80211_ie_htinfo *ht =
 1917            (struct ieee80211_ie_htinfo *) bo->bo_htinfo;
 1918 
 1919         /* XXX only update on channel change */
 1920         ht->hi_ctrlchannel = ieee80211_chan2ieee(ic, ic->ic_bsschan);
 1921         ht->hi_byte1 = IEEE80211_HTINFO_RIFSMODE_PROH;
 1922         if (IEEE80211_IS_CHAN_HT40U(ic->ic_bsschan))
 1923                 ht->hi_byte1 |= IEEE80211_HTINFO_2NDCHAN_ABOVE;
 1924         else if (IEEE80211_IS_CHAN_HT40D(ic->ic_bsschan))
 1925                 ht->hi_byte1 |= IEEE80211_HTINFO_2NDCHAN_BELOW;
 1926         else
 1927                 ht->hi_byte1 |= IEEE80211_HTINFO_2NDCHAN_NONE;
 1928         if (IEEE80211_IS_CHAN_HT40(ic->ic_bsschan))
 1929                 ht->hi_byte1 |= IEEE80211_HTINFO_TXWIDTH_2040;
 1930 
 1931         /* protection mode */
 1932         ht->hi_byte2 = (ht->hi_byte2 &~ PROTMODE) | ic->ic_curhtprotmode;
 1933 
 1934         /* XXX propagate to vendor ie's */
 1935 #undef PROTMODE
 1936 }
 1937 
 1938 /*
 1939  * Add body of an HTINFO information element.
 1940  *
 1941  * NB: We don't use struct ieee80211_ie_htinfo because we can
 1942  * be called to fillin both a standard ie and a compat ie that
 1943  * has a vendor OUI at the front.
 1944  */
 1945 static uint8_t *
 1946 ieee80211_add_htinfo_body(uint8_t *frm, struct ieee80211_node *ni)
 1947 {
 1948         struct ieee80211com *ic = ni->ni_ic;
 1949 
 1950         /* pre-zero remainder of ie */
 1951         memset(frm, 0, sizeof(struct ieee80211_ie_htinfo) - 2);
 1952 
 1953         /* primary/control channel center */
 1954         *frm++ = ieee80211_chan2ieee(ic, ic->ic_bsschan);
 1955 
 1956         frm[0] = IEEE80211_HTINFO_RIFSMODE_PROH;
 1957         if (IEEE80211_IS_CHAN_HT40U(ic->ic_bsschan))
 1958                 frm[0] |= IEEE80211_HTINFO_2NDCHAN_ABOVE;
 1959         else if (IEEE80211_IS_CHAN_HT40D(ic->ic_bsschan))
 1960                 frm[0] |= IEEE80211_HTINFO_2NDCHAN_BELOW;
 1961         else
 1962                 frm[0] |= IEEE80211_HTINFO_2NDCHAN_NONE;
 1963         if (IEEE80211_IS_CHAN_HT40(ic->ic_bsschan))
 1964                 frm[0] |= IEEE80211_HTINFO_TXWIDTH_2040;
 1965 
 1966         frm[1] = ic->ic_curhtprotmode;
 1967 
 1968         frm += 5;
 1969 
 1970         /* basic MCS set */
 1971         ieee80211_set_basic_htrates(frm, &ni->ni_htrates);
 1972         frm += sizeof(struct ieee80211_ie_htinfo) -
 1973                 __offsetof(struct ieee80211_ie_htinfo, hi_basicmcsset);
 1974         return frm;
 1975 }
 1976 
 1977 /*
 1978  * Add 802.11n HT information information element.
 1979  */
 1980 uint8_t *
 1981 ieee80211_add_htinfo(uint8_t *frm, struct ieee80211_node *ni)
 1982 {
 1983         frm[0] = IEEE80211_ELEMID_HTINFO;
 1984         frm[1] = sizeof(struct ieee80211_ie_htinfo) - 2;
 1985         return ieee80211_add_htinfo_body(frm + 2, ni);
 1986 }
 1987 
 1988 /*
 1989  * Add Broadcom OUI wrapped standard HTINFO ie; this is
 1990  * used for compatibility w/ pre-draft implementations.
 1991  */
 1992 uint8_t *
 1993 ieee80211_add_htinfo_vendor(uint8_t *frm, struct ieee80211_node *ni)
 1994 {
 1995         frm[0] = IEEE80211_ELEMID_VENDOR;
 1996         frm[1] = 4 + sizeof(struct ieee80211_ie_htinfo) - 2;
 1997         frm[2] = (BCM_OUI >> 0) & 0xff;
 1998         frm[3] = (BCM_OUI >> 8) & 0xff;
 1999         frm[4] = (BCM_OUI >> 16) & 0xff;
 2000         frm[5] = BCM_OUI_HTINFO;
 2001         return ieee80211_add_htinfo_body(frm + 6, ni);
 2002 }

Cache object: 0d6b4515c490850ed8aacbb12c63cb6f


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.