The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/net80211/ieee80211_tdma.c

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    1 /*-
    2  * Copyright (c) 2007-2009 Sam Leffler, Errno Consulting
    3  * Copyright (c) 2007-2009 Intel Corporation
    4  * All rights reserved.
    5  *
    6  * Redistribution and use in source and binary forms, with or without
    7  * modification, are permitted provided that the following conditions
    8  * are met:
    9  * 1. Redistributions of source code must retain the above copyright
   10  *    notice, this list of conditions and the following disclaimer.
   11  * 2. Redistributions in binary form must reproduce the above copyright
   12  *    notice, this list of conditions and the following disclaimer in the
   13  *    documentation and/or other materials provided with the distribution.
   14  *
   15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   25  */
   26 
   27 #include <sys/cdefs.h>
   28 #ifdef __FreeBSD__
   29 __FBSDID("$FreeBSD: releng/8.0/sys/net80211/ieee80211_tdma.c 193114 2009-05-30 19:57:31Z sam $");
   30 #endif
   31 
   32 /*
   33  * IEEE 802.11 TDMA mode support.
   34  */
   35 #include "opt_inet.h"
   36 #include "opt_tdma.h"
   37 #include "opt_wlan.h"
   38 
   39 #include <sys/param.h>
   40 #include <sys/systm.h> 
   41 #include <sys/mbuf.h>   
   42 #include <sys/malloc.h>
   43 #include <sys/kernel.h>
   44 
   45 #include <sys/socket.h>
   46 #include <sys/sockio.h>
   47 #include <sys/endian.h>
   48 #include <sys/errno.h>
   49 #include <sys/proc.h>
   50 #include <sys/sysctl.h>
   51 
   52 #include <net/if.h>
   53 #include <net/if_media.h>
   54 #include <net/if_llc.h>
   55 #include <net/ethernet.h>
   56 
   57 #include <net/bpf.h>
   58 
   59 #include <net80211/ieee80211_var.h>
   60 #include <net80211/ieee80211_tdma.h>
   61 #include <net80211/ieee80211_input.h>
   62 
   63 #ifndef TDMA_SLOTLEN_DEFAULT
   64 #define TDMA_SLOTLEN_DEFAULT    10*1000         /* 10ms */
   65 #endif
   66 #ifndef TDMA_SLOTCNT_DEFAULT
   67 #define TDMA_SLOTCNT_DEFAULT    2               /* 2x (pt-to-pt) */
   68 #endif
   69 #ifndef TDMA_BINTVAL_DEFAULT
   70 #define TDMA_BINTVAL_DEFAULT    5               /* 5x ~= 100TU beacon intvl */
   71 #endif
   72 #ifndef TDMA_TXRATE_11B_DEFAULT
   73 #define TDMA_TXRATE_11B_DEFAULT 2*11
   74 #endif
   75 #ifndef TDMA_TXRATE_11G_DEFAULT
   76 #define TDMA_TXRATE_11G_DEFAULT 2*24
   77 #endif
   78 #ifndef TDMA_TXRATE_11A_DEFAULT
   79 #define TDMA_TXRATE_11A_DEFAULT 2*24
   80 #endif
   81 #ifndef TDMA_TXRATE_TURBO_DEFAULT
   82 #define TDMA_TXRATE_TURBO_DEFAULT       2*24
   83 #endif
   84 #ifndef TDMA_TXRATE_HALF_DEFAULT
   85 #define TDMA_TXRATE_HALF_DEFAULT        2*12
   86 #endif
   87 #ifndef TDMA_TXRATE_QUARTER_DEFAULT
   88 #define TDMA_TXRATE_QUARTER_DEFAULT     2*6
   89 #endif
   90 #ifndef TDMA_TXRATE_11NA_DEFAULT
   91 #define TDMA_TXRATE_11NA_DEFAULT        (4 | IEEE80211_RATE_MCS)
   92 #endif
   93 #ifndef TDMA_TXRATE_11NG_DEFAULT
   94 #define TDMA_TXRATE_11NG_DEFAULT        (4 | IEEE80211_RATE_MCS)
   95 #endif
   96 
   97 #define TDMA_VERSION_VALID(_version) \
   98         (TDMA_VERSION_V2 <= (_version) && (_version) <= TDMA_VERSION)
   99 #define TDMA_SLOTCNT_VALID(_slotcnt) \
  100         (2 <= (_slotcnt) && (_slotcnt) <= TDMA_MAXSLOTS)
  101 /* XXX magic constants */
  102 #define TDMA_SLOTLEN_VALID(_slotlen) \
  103         (2*100 <= (_slotlen) && (unsigned)(_slotlen) <= 0xfffff)
  104 /* XXX probably should set a max */
  105 #define TDMA_BINTVAL_VALID(_bintval)    (1 <= (_bintval))
  106 
  107 /*
  108  * This code is not prepared to handle more than 2 slots.
  109  */
  110 CTASSERT(TDMA_MAXSLOTS == 2);
  111 
  112 static void tdma_vdetach(struct ieee80211vap *vap);
  113 static int tdma_newstate(struct ieee80211vap *, enum ieee80211_state, int);
  114 static void tdma_beacon_miss(struct ieee80211vap *vap);
  115 static void tdma_recv_mgmt(struct ieee80211_node *, struct mbuf *,
  116         int subtype, int rssi, int nf);
  117 static int tdma_update(struct ieee80211vap *vap,
  118         const struct ieee80211_tdma_param *tdma, struct ieee80211_node *ni,
  119         int pickslot);
  120 static int tdma_process_params(struct ieee80211_node *ni,
  121         const u_int8_t *ie, int rssi, int nf, const struct ieee80211_frame *wh);
  122 
  123 static void
  124 settxparms(struct ieee80211vap *vap, enum ieee80211_phymode mode, int rate)
  125 {
  126         vap->iv_txparms[mode].ucastrate = rate;
  127         vap->iv_txparms[mode].mcastrate = rate;
  128 }
  129 
  130 static void
  131 setackpolicy(struct ieee80211com *ic, int noack)
  132 {
  133         struct ieee80211_wme_state *wme = &ic->ic_wme;
  134         int ac;
  135 
  136         for (ac = 0; ac < WME_NUM_AC; ac++) {
  137                 wme->wme_chanParams.cap_wmeParams[ac].wmep_noackPolicy = noack;
  138                 wme->wme_wmeChanParams.cap_wmeParams[ac].wmep_noackPolicy = noack;
  139         }
  140 }
  141 
  142 void
  143 ieee80211_tdma_vattach(struct ieee80211vap *vap)
  144 {
  145         struct ieee80211_tdma_state *ts;
  146 
  147         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  148              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  149 
  150         ts = (struct ieee80211_tdma_state *) malloc(
  151              sizeof(struct ieee80211_tdma_state), M_80211_VAP, M_NOWAIT | M_ZERO);
  152         if (ts == NULL) {
  153                 printf("%s: cannot allocate TDMA state block\n", __func__);
  154                 /* NB: fall back to adhdemo mode */
  155                 vap->iv_caps &= ~IEEE80211_C_TDMA;
  156                 return;
  157         }
  158         /* NB: default configuration is passive so no beacons */
  159         ts->tdma_version = TDMA_VERSION;
  160         ts->tdma_slotlen = TDMA_SLOTLEN_DEFAULT;
  161         ts->tdma_slotcnt = TDMA_SLOTCNT_DEFAULT;
  162         ts->tdma_bintval = TDMA_BINTVAL_DEFAULT;
  163         ts->tdma_slot = 1;                      /* passive operation */
  164 
  165         /* setup default fixed rates */
  166         settxparms(vap, IEEE80211_MODE_11A, TDMA_TXRATE_11A_DEFAULT);
  167         settxparms(vap, IEEE80211_MODE_11B, TDMA_TXRATE_11B_DEFAULT);
  168         settxparms(vap, IEEE80211_MODE_11G, TDMA_TXRATE_11G_DEFAULT);
  169         settxparms(vap, IEEE80211_MODE_TURBO_A, TDMA_TXRATE_TURBO_DEFAULT);
  170         settxparms(vap, IEEE80211_MODE_TURBO_G, TDMA_TXRATE_TURBO_DEFAULT);
  171         settxparms(vap, IEEE80211_MODE_STURBO_A, TDMA_TXRATE_TURBO_DEFAULT);
  172         settxparms(vap, IEEE80211_MODE_11NA, TDMA_TXRATE_11NA_DEFAULT);
  173         settxparms(vap, IEEE80211_MODE_11NG, TDMA_TXRATE_11NG_DEFAULT);
  174         settxparms(vap, IEEE80211_MODE_HALF, TDMA_TXRATE_HALF_DEFAULT);
  175         settxparms(vap, IEEE80211_MODE_QUARTER, TDMA_TXRATE_QUARTER_DEFAULT);
  176 
  177         setackpolicy(vap->iv_ic, 1);    /* disable ACK's */
  178 
  179         ts->tdma_opdetach = vap->iv_opdetach;
  180         vap->iv_opdetach = tdma_vdetach;
  181         ts->tdma_newstate = vap->iv_newstate;
  182         vap->iv_newstate = tdma_newstate;
  183         vap->iv_bmiss = tdma_beacon_miss;
  184         ts->tdma_recv_mgmt = vap->iv_recv_mgmt;
  185         vap->iv_recv_mgmt = tdma_recv_mgmt;
  186 
  187         vap->iv_tdma = ts;
  188 }
  189 
  190 static void
  191 tdma_vdetach(struct ieee80211vap *vap)
  192 {
  193         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  194 
  195         if (ts == NULL) {
  196                 /* NB: should not have touched any ic state */
  197                 return;
  198         }
  199         ts->tdma_opdetach(vap);
  200         free(vap->iv_tdma, M_80211_VAP);
  201         vap->iv_tdma = NULL;
  202 
  203         setackpolicy(vap->iv_ic, 0);    /* enable ACK's */
  204 }
  205 
  206 static void
  207 sta_leave(void *arg, struct ieee80211_node *ni)
  208 {
  209         struct ieee80211vap *vap = arg;
  210 
  211         if (ni->ni_vap == vap && ni != vap->iv_bss)
  212                 ieee80211_node_leave(ni);
  213 }
  214 
  215 /*
  216  * TDMA state machine handler.
  217  */
  218 static int
  219 tdma_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
  220 {
  221         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  222         struct ieee80211com *ic = vap->iv_ic;
  223         enum ieee80211_state ostate;
  224         int status;
  225 
  226         IEEE80211_LOCK_ASSERT(ic);
  227 
  228         ostate = vap->iv_state;
  229         IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
  230             __func__, ieee80211_state_name[ostate],
  231             ieee80211_state_name[nstate], arg);
  232 
  233         if (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS)
  234                 callout_stop(&vap->iv_swbmiss);
  235         if (nstate == IEEE80211_S_SCAN &&
  236             (ostate == IEEE80211_S_INIT || ostate == IEEE80211_S_RUN) &&
  237             ts->tdma_slot != 0) {
  238                 /*
  239                  * Override adhoc behaviour when operating as a slave;
  240                  * we need to scan even if the channel is locked.
  241                  */
  242                 vap->iv_state = nstate;                 /* state transition */
  243                 ieee80211_cancel_scan(vap);             /* background scan */
  244                 if (ostate == IEEE80211_S_RUN) {
  245                         /* purge station table; entries are stale */
  246                         ieee80211_iterate_nodes(&ic->ic_sta, sta_leave, vap);
  247                 }
  248                 if (vap->iv_flags_ext & IEEE80211_FEXT_SCANREQ) {
  249                         ieee80211_check_scan(vap,
  250                             vap->iv_scanreq_flags,
  251                             vap->iv_scanreq_duration,
  252                             vap->iv_scanreq_mindwell,
  253                             vap->iv_scanreq_maxdwell,
  254                             vap->iv_scanreq_nssid, vap->iv_scanreq_ssid);
  255                         vap->iv_flags_ext &= ~IEEE80211_FEXT_SCANREQ;
  256                 } else
  257                         ieee80211_check_scan_current(vap);
  258                 status = 0;
  259         } else {
  260                 status = ts->tdma_newstate(vap, nstate, arg);
  261         }
  262         if (status == 0 && 
  263             nstate == IEEE80211_S_RUN && ostate != IEEE80211_S_RUN &&
  264             (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS) &&
  265             ts->tdma_slot != 0 &&
  266             vap->iv_des_chan == IEEE80211_CHAN_ANYC) {
  267                 /*
  268                  * Start s/w beacon miss timer for slave devices w/o
  269                  * hardware support.  Note we do this only if we're
  270                  * not locked to a channel (i.e. roam to follow the
  271                  * master). The 2x is a fudge for our doing this in
  272                  * software.
  273                  */
  274                 vap->iv_swbmiss_period = IEEE80211_TU_TO_TICKS(
  275                     2 * vap->iv_bmissthreshold * ts->tdma_bintval *
  276                     ((ts->tdma_slotcnt * ts->tdma_slotlen) / 1024));
  277                 vap->iv_swbmiss_count = 0;
  278                 callout_reset(&vap->iv_swbmiss, vap->iv_swbmiss_period,
  279                         ieee80211_swbmiss, vap);
  280         }
  281         return status;
  282 }
  283 
  284 static void
  285 tdma_beacon_miss(struct ieee80211vap *vap)
  286 {
  287         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  288 
  289         KASSERT((vap->iv_ic->ic_flags & IEEE80211_F_SCAN) == 0, ("scanning"));
  290         KASSERT(vap->iv_state == IEEE80211_S_RUN,
  291             ("wrong state %d", vap->iv_state));
  292 
  293         IEEE80211_DPRINTF(vap,
  294                 IEEE80211_MSG_STATE | IEEE80211_MSG_TDMA | IEEE80211_MSG_DEBUG,
  295                 "beacon miss, mode %u state %s\n",
  296                 vap->iv_opmode, ieee80211_state_name[vap->iv_state]);
  297 
  298         if (ts->tdma_peer != NULL) {    /* XXX? can this be null? */
  299                 ieee80211_notify_node_leave(vap->iv_bss);
  300                 ts->tdma_peer = NULL;
  301                 /*
  302                  * Treat beacon miss like an associate failure wrt the
  303                  * scan policy; this forces the entry in the scan cache
  304                  * to be ignored after several tries.
  305                  */
  306                 ieee80211_scan_assoc_fail(vap, vap->iv_bss->ni_macaddr,
  307                     IEEE80211_STATUS_TIMEOUT);
  308         }
  309 #if 0
  310         ts->tdma_inuse = 0;             /* clear slot usage */
  311 #endif
  312         ieee80211_new_state(vap, IEEE80211_S_SCAN, 0);
  313 }
  314 
  315 static void
  316 tdma_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
  317         int subtype, int rssi, int nf)
  318 {
  319         struct ieee80211com *ic = ni->ni_ic;
  320         struct ieee80211vap *vap = ni->ni_vap;
  321         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  322 
  323         if (subtype == IEEE80211_FC0_SUBTYPE_BEACON &&
  324             (ic->ic_flags & IEEE80211_F_SCAN) == 0) {
  325                 struct ieee80211_frame *wh = mtod(m0, struct ieee80211_frame *);
  326                 struct ieee80211_scanparams scan;
  327 
  328                 if (ieee80211_parse_beacon(ni, m0, &scan) != 0)
  329                         return;
  330                 if (scan.tdma == NULL) {
  331                         /*
  332                          * TDMA stations must beacon a TDMA ie; ignore
  333                          * any other station.
  334                          * XXX detect overlapping bss and change channel
  335                          */
  336                         IEEE80211_DISCARD(vap,
  337                             IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
  338                             wh, ieee80211_mgt_subtype_name[subtype >>
  339                                 IEEE80211_FC0_SUBTYPE_SHIFT],
  340                             "%s", "no TDMA ie");
  341                         vap->iv_stats.is_rx_mgtdiscard++;
  342                         return;
  343                 }
  344                 if (ni == vap->iv_bss &&
  345                     !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
  346                         /*
  347                          * Fake up a node for this newly
  348                          * discovered member of the IBSS.
  349                          */
  350                         ni = ieee80211_add_neighbor(vap, wh, &scan);
  351                         if (ni == NULL) {
  352                                 /* NB: stat kept for alloc failure */
  353                                 return;
  354                         }
  355                 }
  356                 /*
  357                  * Check for state updates.
  358                  */
  359                 if (IEEE80211_ADDR_EQ(wh->i_addr3, ni->ni_bssid)) {
  360                         /*
  361                          * Count frame now that we know it's to be processed.
  362                          */
  363                         vap->iv_stats.is_rx_beacon++;
  364                         IEEE80211_NODE_STAT(ni, rx_beacons);
  365                         /*
  366                          * Record tsf of last beacon.  NB: this must be
  367                          * done before calling tdma_process_params
  368                          * as deeper routines reference it.
  369                          */
  370                         memcpy(&ni->ni_tstamp.data, scan.tstamp,
  371                                 sizeof(ni->ni_tstamp.data));
  372                         /*
  373                          * Count beacon frame for s/w bmiss handling.
  374                          */
  375                         vap->iv_swbmiss_count++;
  376                         /*
  377                          * Process tdma ie.  The contents are used to sync
  378                          * the slot timing, reconfigure the bss, etc.
  379                          */
  380                         (void) tdma_process_params(ni, scan.tdma, rssi, nf, wh);
  381                         return;
  382                 }
  383                 /*
  384                  * NB: defer remaining work to the adhoc code; this causes
  385                  *     2x parsing of the frame but should happen infrequently
  386                  */
  387         }
  388         ts->tdma_recv_mgmt(ni, m0, subtype, rssi, nf);
  389 }
  390 
  391 /*
  392  * Update TDMA state on receipt of a beacon frame with
  393  * a TDMA information element.  The sender's identity
  394  * is provided so we can track who our peer is.  If pickslot
  395  * is non-zero we scan the slot allocation state in the ie
  396  * to locate a free slot for our use.
  397  */
  398 static int
  399 tdma_update(struct ieee80211vap *vap, const struct ieee80211_tdma_param *tdma,
  400         struct ieee80211_node *ni, int pickslot)
  401 {
  402         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  403         int slot, slotlen, update;
  404 
  405         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  406              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  407 
  408         update = 0;
  409         if (tdma->tdma_slotcnt != ts->tdma_slotcnt) {
  410                 if (!TDMA_SLOTCNT_VALID(tdma->tdma_slotcnt)) {
  411                         if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
  412                                 printf("%s: bad slot cnt %u\n",
  413                                     __func__, tdma->tdma_slotcnt);
  414                         return 0;
  415                 }
  416                 update |= TDMA_UPDATE_SLOTCNT;
  417         }
  418         slotlen = le16toh(tdma->tdma_slotlen) * 100;
  419         if (slotlen != ts->tdma_slotlen) {
  420                 if (!TDMA_SLOTLEN_VALID(slotlen)) {
  421                         if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
  422                                 printf("%s: bad slot len %u\n",
  423                                     __func__, slotlen);
  424                         return 0;
  425                 }
  426                 update |= TDMA_UPDATE_SLOTLEN;
  427         }
  428         if (tdma->tdma_bintval != ts->tdma_bintval) {
  429                 if (!TDMA_BINTVAL_VALID(tdma->tdma_bintval)) {
  430                         if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
  431                                 printf("%s: bad beacon interval %u\n",
  432                                     __func__, tdma->tdma_bintval);
  433                         return 0;
  434                 }
  435                 update |= TDMA_UPDATE_BINTVAL;
  436         }
  437         slot = ts->tdma_slot;
  438         if (pickslot) {
  439                 /*
  440                  * Pick unoccupied slot.  Note we never choose slot 0.
  441                  */
  442                 for (slot = tdma->tdma_slotcnt-1; slot > 0; slot--)
  443                         if (isclr(tdma->tdma_inuse, slot))
  444                                 break;
  445                 if (slot <= 0) {
  446                         printf("%s: no free slot, slotcnt %u inuse: 0x%x\n",
  447                                 __func__, tdma->tdma_slotcnt,
  448                                 tdma->tdma_inuse[0]);
  449                         /* XXX need to do something better */
  450                         return 0;
  451                 }
  452                 if (slot != ts->tdma_slot)
  453                         update |= TDMA_UPDATE_SLOT;
  454         }
  455         if (ni != ts->tdma_peer) {
  456                 /* update everything */
  457                 update = TDMA_UPDATE_SLOT
  458                        | TDMA_UPDATE_SLOTCNT
  459                        | TDMA_UPDATE_SLOTLEN
  460                        | TDMA_UPDATE_BINTVAL;
  461         }
  462 
  463         if (update) {
  464                 /*
  465                  * New/changed parameters; update runtime state.
  466                  */
  467                 /* XXX overwrites user parameters */
  468                 if (update & TDMA_UPDATE_SLOTCNT)
  469                         ts->tdma_slotcnt = tdma->tdma_slotcnt;
  470                 if (update & TDMA_UPDATE_SLOTLEN)
  471                         ts->tdma_slotlen = slotlen;
  472                 if (update & TDMA_UPDATE_SLOT)
  473                         ts->tdma_slot = slot;
  474                 if (update & TDMA_UPDATE_BINTVAL)
  475                         ts->tdma_bintval = tdma->tdma_bintval;
  476                 /* mark beacon to be updated before next xmit */
  477                 ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
  478 
  479                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
  480                     "%s: slot %u slotcnt %u slotlen %u us bintval %u\n",
  481                     __func__, ts->tdma_slot, ts->tdma_slotcnt,
  482                     ts->tdma_slotlen, ts->tdma_bintval);
  483         }
  484         /*
  485          * Notify driver.  Note we can be called before
  486          * entering RUN state if we scanned and are
  487          * joining an existing bss.  In that case do not
  488          * call the driver because not all necessary state
  489          * has been setup.  The next beacon will dtrt.
  490          */
  491         if (vap->iv_state == IEEE80211_S_RUN)
  492                 vap->iv_ic->ic_tdma_update(ni, tdma, update);
  493         /*
  494          * Dispatch join event on first beacon from new master.
  495          */
  496         if (ts->tdma_peer != ni) {
  497                 if (ts->tdma_peer != NULL)
  498                         ieee80211_notify_node_leave(vap->iv_bss);
  499                 ieee80211_notify_node_join(ni, 1);
  500                 /* NB: no reference, we just use the address */
  501                 ts->tdma_peer = ni;
  502         }
  503         return 1;
  504 }
  505 
  506 /*
  507  * Process received TDMA parameters.
  508  */
  509 static int
  510 tdma_process_params(struct ieee80211_node *ni, const u_int8_t *ie,
  511         int rssi, int nf, const struct ieee80211_frame *wh)
  512 {
  513         struct ieee80211vap *vap = ni->ni_vap;
  514         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  515         const struct ieee80211_tdma_param *tdma = 
  516                 (const struct ieee80211_tdma_param *) ie;
  517         u_int len = ie[1];
  518 
  519         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  520              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  521 
  522         if (len < sizeof(*tdma) - 2) {
  523                 IEEE80211_DISCARD_IE(vap,
  524                     IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
  525                     wh, "tdma", "too short, len %u", len);
  526                 return IEEE80211_REASON_IE_INVALID;
  527         }
  528         if (tdma->tdma_version != ts->tdma_version) {
  529                 IEEE80211_DISCARD_IE(vap,
  530                     IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
  531                     wh, "tdma", "bad version %u (ours %u)",
  532                     tdma->tdma_version, ts->tdma_version);
  533                 return IEEE80211_REASON_IE_INVALID;
  534         }
  535         /*
  536          * NB: ideally we'd check against tdma_slotcnt, but that
  537          * would require extra effort so do this easy check that
  538          * covers the work below; more stringent checks are done
  539          * before we make more extensive use of the ie contents.
  540          */
  541         if (tdma->tdma_slot >= TDMA_MAXSLOTS) {
  542                 IEEE80211_DISCARD_IE(vap,
  543                     IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
  544                     wh, "tdma", "invalid slot %u", tdma->tdma_slot);
  545                 return IEEE80211_REASON_IE_INVALID;
  546         }
  547         /*
  548          * Can reach here while scanning, update
  549          * operational state only in RUN state.
  550          */
  551         if (vap->iv_state == IEEE80211_S_RUN) {
  552                 if (tdma->tdma_slot != ts->tdma_slot &&
  553                     isclr(ts->tdma_inuse, tdma->tdma_slot)) {
  554                         IEEE80211_NOTE(vap, IEEE80211_MSG_TDMA, ni,
  555                             "discovered in slot %u", tdma->tdma_slot);
  556                         setbit(ts->tdma_inuse, tdma->tdma_slot);
  557                         /* XXX dispatch event only when operating as master */
  558                         if (ts->tdma_slot == 0)
  559                                 ieee80211_notify_node_join(ni, 1);
  560                 }
  561                 setbit(ts->tdma_active, tdma->tdma_slot);
  562                 if (tdma->tdma_slot == ts->tdma_slot-1) {
  563                         /*
  564                          * Slave tsf synchronization to station
  565                          * just before us in the schedule. The driver
  566                          * is responsible for copying the timestamp
  567                          * of the received beacon into our beacon
  568                          * frame so the sender can calculate round
  569                          * trip time.  We cannot do that here because
  570                          * we don't know how to update our beacon frame.
  571                          */
  572                         (void) tdma_update(vap, tdma, ni, 0);
  573                         /* XXX reschedule swbmiss timer on parameter change */
  574                 } else if (tdma->tdma_slot == ts->tdma_slot+1) {
  575                         uint64_t tstamp;
  576 #if 0
  577                         uint32_t rstamp = (uint32_t) le64toh(rs->tsf);
  578                         int32_t rtt;
  579 #endif
  580                         /*
  581                          * Use returned timstamp to calculate the
  582                          * roundtrip time.
  583                          */
  584                         memcpy(&tstamp, tdma->tdma_tstamp, 8);
  585 #if 0
  586                         /* XXX use only 15 bits of rstamp */
  587                         rtt = rstamp - (le64toh(tstamp) & 0x7fff);
  588                         if (rtt < 0)
  589                                 rtt += 0x7fff;
  590                         /* XXX hack to quiet normal use */
  591                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOT1X,
  592                             "tdma rtt %5u [rstamp %5u tstamp %llu]\n",
  593                             rtt, rstamp,
  594                             (unsigned long long) le64toh(tstamp));
  595 #endif
  596                 } else if (tdma->tdma_slot == ts->tdma_slot &&
  597                     le64toh(ni->ni_tstamp.tsf) > vap->iv_bss->ni_tstamp.tsf) {
  598                         /*
  599                          * Station using the same slot as us and has
  600                          * been around longer than us; we must move.
  601                          * Note this can happen if stations do not
  602                          * see each other while scanning.
  603                          */
  604                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
  605                             "slot %u collision rxtsf %llu tsf %llu\n",
  606                             tdma->tdma_slot,
  607                             (unsigned long long) le64toh(ni->ni_tstamp.tsf),
  608                             vap->iv_bss->ni_tstamp.tsf);
  609                         setbit(ts->tdma_inuse, tdma->tdma_slot);
  610 
  611                         (void) tdma_update(vap, tdma, ni, 1);
  612                 }
  613         }
  614         return 0;
  615 }
  616 
  617 int
  618 ieee80211_tdma_getslot(struct ieee80211vap *vap)
  619 {
  620         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  621 
  622         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  623              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  624         return ts->tdma_slot;
  625 }
  626 
  627 /*
  628  * Parse a TDMA ie on station join and use it to setup node state.
  629  */
  630 void
  631 ieee80211_parse_tdma(struct ieee80211_node *ni, const uint8_t *ie)
  632 {
  633         struct ieee80211vap *vap = ni->ni_vap;
  634 
  635         if (vap->iv_caps & IEEE80211_C_TDMA) {
  636                 const struct ieee80211_tdma_param *tdma =
  637                     (const struct ieee80211_tdma_param *)ie;
  638                 struct ieee80211_tdma_state *ts = vap->iv_tdma;
  639                 /*
  640                  * Adopt TDMA configuration when joining an
  641                  * existing network.
  642                  */
  643                 setbit(ts->tdma_inuse, tdma->tdma_slot);
  644                 (void) tdma_update(vap, tdma, ni, 1);
  645                 /*
  646                  * Propagate capabilities based on the local
  647                  * configuration and the remote station's advertised
  648                  * capabilities. In particular this permits us to
  649                  * enable use of QoS to disable ACK's.
  650                  */
  651                 if ((vap->iv_flags & IEEE80211_F_WME) &&
  652                     ni->ni_ies.wme_ie != NULL)
  653                         ni->ni_flags |= IEEE80211_NODE_QOS;
  654         }
  655 }
  656 
  657 #define TDMA_OUI_BYTES          0x00, 0x03, 0x7f
  658 /*
  659  * Add a TDMA parameters element to a frame.
  660  */
  661 uint8_t *
  662 ieee80211_add_tdma(uint8_t *frm, struct ieee80211vap *vap)
  663 {
  664 #define ADDSHORT(frm, v) do {                   \
  665         frm[0] = (v) & 0xff;                    \
  666         frm[1] = (v) >> 8;                      \
  667         frm += 2;                               \
  668 } while (0)
  669         static const struct ieee80211_tdma_param param = {
  670                 .tdma_id        = IEEE80211_ELEMID_VENDOR,
  671                 .tdma_len       = sizeof(struct ieee80211_tdma_param) - 2,
  672                 .tdma_oui       = { TDMA_OUI_BYTES },
  673                 .tdma_type      = TDMA_OUI_TYPE,
  674                 .tdma_subtype   = TDMA_SUBTYPE_PARAM,
  675                 .tdma_version   = TDMA_VERSION,
  676         };
  677         const struct ieee80211_tdma_state *ts = vap->iv_tdma;
  678         uint16_t slotlen;
  679 
  680         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  681              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  682 
  683         memcpy(frm, &param, sizeof(param));
  684         frm += __offsetof(struct ieee80211_tdma_param, tdma_slot);
  685         *frm++ = ts->tdma_slot;
  686         *frm++ = ts->tdma_slotcnt;
  687         /* NB: convert units to fit in 16-bits */
  688         slotlen = ts->tdma_slotlen / 100;       /* 100us units */
  689         ADDSHORT(frm, slotlen);
  690         *frm++ = ts->tdma_bintval;
  691         *frm++ = ts->tdma_inuse[0];
  692         frm += 10;                              /* pad+timestamp */
  693         return frm; 
  694 #undef ADDSHORT
  695 }
  696 #undef TDMA_OUI_BYTES
  697 
  698 /*
  699  * Update TDMA state at TBTT.
  700  */
  701 void
  702 ieee80211_tdma_update_beacon(struct ieee80211vap *vap,
  703         struct ieee80211_beacon_offsets *bo)
  704 {
  705         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  706 
  707         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  708              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  709 
  710         if (isset(bo->bo_flags,  IEEE80211_BEACON_TDMA)) {
  711                 (void) ieee80211_add_tdma(bo->bo_tdma, vap);
  712                 clrbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
  713         }
  714         if (ts->tdma_slot != 0)         /* only on master */
  715                 return;
  716         if (ts->tdma_count <= 0) {
  717                 /*
  718                  * Time to update the mask of active/inuse stations.
  719                  * We track stations that we've received a beacon
  720                  * frame from and update this mask periodically.
  721                  * This allows us to miss a few beacons before marking
  722                  * a slot free for re-use.
  723                  */
  724                 ts->tdma_inuse[0] = ts->tdma_active[0];
  725                 ts->tdma_active[0] = 0x01;
  726                 /* update next time 'round */
  727                 /* XXX use notify framework */
  728                 setbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
  729                 /* NB: use s/w beacon miss threshold; may be too high */
  730                 ts->tdma_count = vap->iv_bmissthreshold-1;
  731         } else
  732                 ts->tdma_count--;
  733 }
  734 
  735 static int
  736 tdma_ioctl_get80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
  737 {
  738         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  739 
  740         if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
  741                 return EOPNOTSUPP;
  742 
  743         switch (ireq->i_type) {
  744         case IEEE80211_IOC_TDMA_SLOT:
  745                 ireq->i_val = ts->tdma_slot;
  746                 break;
  747         case IEEE80211_IOC_TDMA_SLOTCNT:
  748                 ireq->i_val = ts->tdma_slotcnt;
  749                 break;
  750         case IEEE80211_IOC_TDMA_SLOTLEN:
  751                 ireq->i_val = ts->tdma_slotlen;
  752                 break;
  753         case IEEE80211_IOC_TDMA_BINTERVAL:
  754                 ireq->i_val = ts->tdma_bintval;
  755                 break;
  756         default:
  757                 return ENOSYS;
  758         }
  759         return 0;
  760 }
  761 IEEE80211_IOCTL_GET(tdma, tdma_ioctl_get80211);
  762 
  763 static int
  764 tdma_ioctl_set80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
  765 {
  766         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  767 
  768         if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
  769                 return EOPNOTSUPP;
  770 
  771         switch (ireq->i_type) {
  772         case IEEE80211_IOC_TDMA_SLOT:
  773                 if (!(0 <= ireq->i_val && ireq->i_val <= ts->tdma_slotcnt))
  774                         return EINVAL;
  775                 if (ireq->i_val != ts->tdma_slot) {
  776                         ts->tdma_slot = ireq->i_val;
  777                         goto restart;
  778                 }
  779                 break;
  780         case IEEE80211_IOC_TDMA_SLOTCNT:
  781                 if (!TDMA_SLOTCNT_VALID(ireq->i_val))
  782                         return EINVAL;
  783                 if (ireq->i_val != ts->tdma_slotcnt) {
  784                         ts->tdma_slotcnt = ireq->i_val;
  785                         goto restart;
  786                 }
  787                 break;
  788         case IEEE80211_IOC_TDMA_SLOTLEN:
  789                 /*
  790                  * XXX
  791                  * 150 insures at least 1/8 TU
  792                  * 0xfffff is the max duration for bursting
  793                  * (implict by way of 16-bit data type for i_val)
  794                  */
  795                 if (!TDMA_SLOTLEN_VALID(ireq->i_val))
  796                         return EINVAL;
  797                 if (ireq->i_val != ts->tdma_slotlen) {
  798                         ts->tdma_slotlen = ireq->i_val;
  799                         goto restart;
  800                 }
  801                 break;
  802         case IEEE80211_IOC_TDMA_BINTERVAL:
  803                 if (!TDMA_BINTVAL_VALID(ireq->i_val))
  804                         return EINVAL;
  805                 if (ireq->i_val != ts->tdma_bintval) {
  806                         ts->tdma_bintval = ireq->i_val;
  807                         goto restart;
  808                 }
  809                 break;
  810         default:
  811                 return ENOSYS;
  812         }
  813         return 0;
  814 restart:
  815         ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
  816         return ERESTART;
  817 }
  818 IEEE80211_IOCTL_SET(tdma, tdma_ioctl_set80211);

Cache object: 0955eb110e037fb929be293f5c9d0ca4


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