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/8.4/sys/net80211/ieee80211_tdma.c 206780 2010-04-17 23:48:07Z weongyo $");
   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         callout_stop(&vap->iv_swbmiss);
  299 
  300         if (ts->tdma_peer != NULL) {    /* XXX? can this be null? */
  301                 ieee80211_notify_node_leave(vap->iv_bss);
  302                 ts->tdma_peer = NULL;
  303                 /*
  304                  * Treat beacon miss like an associate failure wrt the
  305                  * scan policy; this forces the entry in the scan cache
  306                  * to be ignored after several tries.
  307                  */
  308                 ieee80211_scan_assoc_fail(vap, vap->iv_bss->ni_macaddr,
  309                     IEEE80211_STATUS_TIMEOUT);
  310         }
  311 #if 0
  312         ts->tdma_inuse = 0;             /* clear slot usage */
  313 #endif
  314         ieee80211_new_state(vap, IEEE80211_S_SCAN, 0);
  315 }
  316 
  317 static void
  318 tdma_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
  319         int subtype, int rssi, int nf)
  320 {
  321         struct ieee80211com *ic = ni->ni_ic;
  322         struct ieee80211vap *vap = ni->ni_vap;
  323         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  324 
  325         if (subtype == IEEE80211_FC0_SUBTYPE_BEACON &&
  326             (ic->ic_flags & IEEE80211_F_SCAN) == 0) {
  327                 struct ieee80211_frame *wh = mtod(m0, struct ieee80211_frame *);
  328                 struct ieee80211_scanparams scan;
  329 
  330                 if (ieee80211_parse_beacon(ni, m0, &scan) != 0)
  331                         return;
  332                 if (scan.tdma == NULL) {
  333                         /*
  334                          * TDMA stations must beacon a TDMA ie; ignore
  335                          * any other station.
  336                          * XXX detect overlapping bss and change channel
  337                          */
  338                         IEEE80211_DISCARD(vap,
  339                             IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
  340                             wh, ieee80211_mgt_subtype_name[subtype >>
  341                                 IEEE80211_FC0_SUBTYPE_SHIFT],
  342                             "%s", "no TDMA ie");
  343                         vap->iv_stats.is_rx_mgtdiscard++;
  344                         return;
  345                 }
  346                 if (ni == vap->iv_bss &&
  347                     !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
  348                         /*
  349                          * Fake up a node for this newly
  350                          * discovered member of the IBSS.
  351                          */
  352                         ni = ieee80211_add_neighbor(vap, wh, &scan);
  353                         if (ni == NULL) {
  354                                 /* NB: stat kept for alloc failure */
  355                                 return;
  356                         }
  357                 }
  358                 /*
  359                  * Check for state updates.
  360                  */
  361                 if (IEEE80211_ADDR_EQ(wh->i_addr3, ni->ni_bssid)) {
  362                         /*
  363                          * Count frame now that we know it's to be processed.
  364                          */
  365                         vap->iv_stats.is_rx_beacon++;
  366                         IEEE80211_NODE_STAT(ni, rx_beacons);
  367                         /*
  368                          * Record tsf of last beacon.  NB: this must be
  369                          * done before calling tdma_process_params
  370                          * as deeper routines reference it.
  371                          */
  372                         memcpy(&ni->ni_tstamp.data, scan.tstamp,
  373                                 sizeof(ni->ni_tstamp.data));
  374                         /*
  375                          * Count beacon frame for s/w bmiss handling.
  376                          */
  377                         vap->iv_swbmiss_count++;
  378                         /*
  379                          * Process tdma ie.  The contents are used to sync
  380                          * the slot timing, reconfigure the bss, etc.
  381                          */
  382                         (void) tdma_process_params(ni, scan.tdma, rssi, nf, wh);
  383                         return;
  384                 }
  385                 /*
  386                  * NB: defer remaining work to the adhoc code; this causes
  387                  *     2x parsing of the frame but should happen infrequently
  388                  */
  389         }
  390         ts->tdma_recv_mgmt(ni, m0, subtype, rssi, nf);
  391 }
  392 
  393 /*
  394  * Update TDMA state on receipt of a beacon frame with
  395  * a TDMA information element.  The sender's identity
  396  * is provided so we can track who our peer is.  If pickslot
  397  * is non-zero we scan the slot allocation state in the ie
  398  * to locate a free slot for our use.
  399  */
  400 static int
  401 tdma_update(struct ieee80211vap *vap, const struct ieee80211_tdma_param *tdma,
  402         struct ieee80211_node *ni, int pickslot)
  403 {
  404         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  405         int slot, slotlen, update;
  406 
  407         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  408              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  409 
  410         update = 0;
  411         if (tdma->tdma_slotcnt != ts->tdma_slotcnt) {
  412                 if (!TDMA_SLOTCNT_VALID(tdma->tdma_slotcnt)) {
  413                         if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
  414                                 printf("%s: bad slot cnt %u\n",
  415                                     __func__, tdma->tdma_slotcnt);
  416                         return 0;
  417                 }
  418                 update |= TDMA_UPDATE_SLOTCNT;
  419         }
  420         slotlen = le16toh(tdma->tdma_slotlen) * 100;
  421         if (slotlen != ts->tdma_slotlen) {
  422                 if (!TDMA_SLOTLEN_VALID(slotlen)) {
  423                         if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
  424                                 printf("%s: bad slot len %u\n",
  425                                     __func__, slotlen);
  426                         return 0;
  427                 }
  428                 update |= TDMA_UPDATE_SLOTLEN;
  429         }
  430         if (tdma->tdma_bintval != ts->tdma_bintval) {
  431                 if (!TDMA_BINTVAL_VALID(tdma->tdma_bintval)) {
  432                         if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
  433                                 printf("%s: bad beacon interval %u\n",
  434                                     __func__, tdma->tdma_bintval);
  435                         return 0;
  436                 }
  437                 update |= TDMA_UPDATE_BINTVAL;
  438         }
  439         slot = ts->tdma_slot;
  440         if (pickslot) {
  441                 /*
  442                  * Pick unoccupied slot.  Note we never choose slot 0.
  443                  */
  444                 for (slot = tdma->tdma_slotcnt-1; slot > 0; slot--)
  445                         if (isclr(tdma->tdma_inuse, slot))
  446                                 break;
  447                 if (slot <= 0) {
  448                         printf("%s: no free slot, slotcnt %u inuse: 0x%x\n",
  449                                 __func__, tdma->tdma_slotcnt,
  450                                 tdma->tdma_inuse[0]);
  451                         /* XXX need to do something better */
  452                         return 0;
  453                 }
  454                 if (slot != ts->tdma_slot)
  455                         update |= TDMA_UPDATE_SLOT;
  456         }
  457         if (ni != ts->tdma_peer) {
  458                 /* update everything */
  459                 update = TDMA_UPDATE_SLOT
  460                        | TDMA_UPDATE_SLOTCNT
  461                        | TDMA_UPDATE_SLOTLEN
  462                        | TDMA_UPDATE_BINTVAL;
  463         }
  464 
  465         if (update) {
  466                 /*
  467                  * New/changed parameters; update runtime state.
  468                  */
  469                 /* XXX overwrites user parameters */
  470                 if (update & TDMA_UPDATE_SLOTCNT)
  471                         ts->tdma_slotcnt = tdma->tdma_slotcnt;
  472                 if (update & TDMA_UPDATE_SLOTLEN)
  473                         ts->tdma_slotlen = slotlen;
  474                 if (update & TDMA_UPDATE_SLOT)
  475                         ts->tdma_slot = slot;
  476                 if (update & TDMA_UPDATE_BINTVAL)
  477                         ts->tdma_bintval = tdma->tdma_bintval;
  478                 /* mark beacon to be updated before next xmit */
  479                 ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
  480 
  481                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
  482                     "%s: slot %u slotcnt %u slotlen %u us bintval %u\n",
  483                     __func__, ts->tdma_slot, ts->tdma_slotcnt,
  484                     ts->tdma_slotlen, ts->tdma_bintval);
  485         }
  486         /*
  487          * Notify driver.  Note we can be called before
  488          * entering RUN state if we scanned and are
  489          * joining an existing bss.  In that case do not
  490          * call the driver because not all necessary state
  491          * has been setup.  The next beacon will dtrt.
  492          */
  493         if (vap->iv_state == IEEE80211_S_RUN)
  494                 vap->iv_ic->ic_tdma_update(ni, tdma, update);
  495         /*
  496          * Dispatch join event on first beacon from new master.
  497          */
  498         if (ts->tdma_peer != ni) {
  499                 if (ts->tdma_peer != NULL)
  500                         ieee80211_notify_node_leave(vap->iv_bss);
  501                 ieee80211_notify_node_join(ni, 1);
  502                 /* NB: no reference, we just use the address */
  503                 ts->tdma_peer = ni;
  504         }
  505         return 1;
  506 }
  507 
  508 /*
  509  * Process received TDMA parameters.
  510  */
  511 static int
  512 tdma_process_params(struct ieee80211_node *ni, const u_int8_t *ie,
  513         int rssi, int nf, const struct ieee80211_frame *wh)
  514 {
  515         struct ieee80211vap *vap = ni->ni_vap;
  516         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  517         const struct ieee80211_tdma_param *tdma = 
  518                 (const struct ieee80211_tdma_param *) ie;
  519         u_int len = ie[1];
  520 
  521         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  522              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  523 
  524         if (len < sizeof(*tdma) - 2) {
  525                 IEEE80211_DISCARD_IE(vap,
  526                     IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
  527                     wh, "tdma", "too short, len %u", len);
  528                 return IEEE80211_REASON_IE_INVALID;
  529         }
  530         if (tdma->tdma_version != ts->tdma_version) {
  531                 IEEE80211_DISCARD_IE(vap,
  532                     IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
  533                     wh, "tdma", "bad version %u (ours %u)",
  534                     tdma->tdma_version, ts->tdma_version);
  535                 return IEEE80211_REASON_IE_INVALID;
  536         }
  537         /*
  538          * NB: ideally we'd check against tdma_slotcnt, but that
  539          * would require extra effort so do this easy check that
  540          * covers the work below; more stringent checks are done
  541          * before we make more extensive use of the ie contents.
  542          */
  543         if (tdma->tdma_slot >= TDMA_MAXSLOTS) {
  544                 IEEE80211_DISCARD_IE(vap,
  545                     IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
  546                     wh, "tdma", "invalid slot %u", tdma->tdma_slot);
  547                 return IEEE80211_REASON_IE_INVALID;
  548         }
  549         /*
  550          * Can reach here while scanning, update
  551          * operational state only in RUN state.
  552          */
  553         if (vap->iv_state == IEEE80211_S_RUN) {
  554                 if (tdma->tdma_slot != ts->tdma_slot &&
  555                     isclr(ts->tdma_inuse, tdma->tdma_slot)) {
  556                         IEEE80211_NOTE(vap, IEEE80211_MSG_TDMA, ni,
  557                             "discovered in slot %u", tdma->tdma_slot);
  558                         setbit(ts->tdma_inuse, tdma->tdma_slot);
  559                         /* XXX dispatch event only when operating as master */
  560                         if (ts->tdma_slot == 0)
  561                                 ieee80211_notify_node_join(ni, 1);
  562                 }
  563                 setbit(ts->tdma_active, tdma->tdma_slot);
  564                 if (tdma->tdma_slot == ts->tdma_slot-1) {
  565                         /*
  566                          * Slave tsf synchronization to station
  567                          * just before us in the schedule. The driver
  568                          * is responsible for copying the timestamp
  569                          * of the received beacon into our beacon
  570                          * frame so the sender can calculate round
  571                          * trip time.  We cannot do that here because
  572                          * we don't know how to update our beacon frame.
  573                          */
  574                         (void) tdma_update(vap, tdma, ni, 0);
  575                         /* XXX reschedule swbmiss timer on parameter change */
  576                 } else if (tdma->tdma_slot == ts->tdma_slot+1) {
  577                         uint64_t tstamp;
  578 #if 0
  579                         uint32_t rstamp = (uint32_t) le64toh(rs->tsf);
  580                         int32_t rtt;
  581 #endif
  582                         /*
  583                          * Use returned timstamp to calculate the
  584                          * roundtrip time.
  585                          */
  586                         memcpy(&tstamp, tdma->tdma_tstamp, 8);
  587 #if 0
  588                         /* XXX use only 15 bits of rstamp */
  589                         rtt = rstamp - (le64toh(tstamp) & 0x7fff);
  590                         if (rtt < 0)
  591                                 rtt += 0x7fff;
  592                         /* XXX hack to quiet normal use */
  593                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOT1X,
  594                             "tdma rtt %5u [rstamp %5u tstamp %llu]\n",
  595                             rtt, rstamp,
  596                             (unsigned long long) le64toh(tstamp));
  597 #endif
  598                 } else if (tdma->tdma_slot == ts->tdma_slot &&
  599                     le64toh(ni->ni_tstamp.tsf) > vap->iv_bss->ni_tstamp.tsf) {
  600                         /*
  601                          * Station using the same slot as us and has
  602                          * been around longer than us; we must move.
  603                          * Note this can happen if stations do not
  604                          * see each other while scanning.
  605                          */
  606                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
  607                             "slot %u collision rxtsf %llu tsf %llu\n",
  608                             tdma->tdma_slot,
  609                             (unsigned long long) le64toh(ni->ni_tstamp.tsf),
  610                             vap->iv_bss->ni_tstamp.tsf);
  611                         setbit(ts->tdma_inuse, tdma->tdma_slot);
  612 
  613                         (void) tdma_update(vap, tdma, ni, 1);
  614                 }
  615         }
  616         return 0;
  617 }
  618 
  619 int
  620 ieee80211_tdma_getslot(struct ieee80211vap *vap)
  621 {
  622         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  623 
  624         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  625              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  626         return ts->tdma_slot;
  627 }
  628 
  629 /*
  630  * Parse a TDMA ie on station join and use it to setup node state.
  631  */
  632 void
  633 ieee80211_parse_tdma(struct ieee80211_node *ni, const uint8_t *ie)
  634 {
  635         struct ieee80211vap *vap = ni->ni_vap;
  636 
  637         if (vap->iv_caps & IEEE80211_C_TDMA) {
  638                 const struct ieee80211_tdma_param *tdma =
  639                     (const struct ieee80211_tdma_param *)ie;
  640                 struct ieee80211_tdma_state *ts = vap->iv_tdma;
  641                 /*
  642                  * Adopt TDMA configuration when joining an
  643                  * existing network.
  644                  */
  645                 setbit(ts->tdma_inuse, tdma->tdma_slot);
  646                 (void) tdma_update(vap, tdma, ni, 1);
  647                 /*
  648                  * Propagate capabilities based on the local
  649                  * configuration and the remote station's advertised
  650                  * capabilities. In particular this permits us to
  651                  * enable use of QoS to disable ACK's.
  652                  */
  653                 if ((vap->iv_flags & IEEE80211_F_WME) &&
  654                     ni->ni_ies.wme_ie != NULL)
  655                         ni->ni_flags |= IEEE80211_NODE_QOS;
  656         }
  657 }
  658 
  659 #define TDMA_OUI_BYTES          0x00, 0x03, 0x7f
  660 /*
  661  * Add a TDMA parameters element to a frame.
  662  */
  663 uint8_t *
  664 ieee80211_add_tdma(uint8_t *frm, struct ieee80211vap *vap)
  665 {
  666 #define ADDSHORT(frm, v) do {                   \
  667         frm[0] = (v) & 0xff;                    \
  668         frm[1] = (v) >> 8;                      \
  669         frm += 2;                               \
  670 } while (0)
  671         static const struct ieee80211_tdma_param param = {
  672                 .tdma_id        = IEEE80211_ELEMID_VENDOR,
  673                 .tdma_len       = sizeof(struct ieee80211_tdma_param) - 2,
  674                 .tdma_oui       = { TDMA_OUI_BYTES },
  675                 .tdma_type      = TDMA_OUI_TYPE,
  676                 .tdma_subtype   = TDMA_SUBTYPE_PARAM,
  677                 .tdma_version   = TDMA_VERSION,
  678         };
  679         const struct ieee80211_tdma_state *ts = vap->iv_tdma;
  680         uint16_t slotlen;
  681 
  682         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  683              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  684 
  685         memcpy(frm, &param, sizeof(param));
  686         frm += __offsetof(struct ieee80211_tdma_param, tdma_slot);
  687         *frm++ = ts->tdma_slot;
  688         *frm++ = ts->tdma_slotcnt;
  689         /* NB: convert units to fit in 16-bits */
  690         slotlen = ts->tdma_slotlen / 100;       /* 100us units */
  691         ADDSHORT(frm, slotlen);
  692         *frm++ = ts->tdma_bintval;
  693         *frm++ = ts->tdma_inuse[0];
  694         frm += 10;                              /* pad+timestamp */
  695         return frm; 
  696 #undef ADDSHORT
  697 }
  698 #undef TDMA_OUI_BYTES
  699 
  700 /*
  701  * Update TDMA state at TBTT.
  702  */
  703 void
  704 ieee80211_tdma_update_beacon(struct ieee80211vap *vap,
  705         struct ieee80211_beacon_offsets *bo)
  706 {
  707         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  708 
  709         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  710              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  711 
  712         if (isset(bo->bo_flags,  IEEE80211_BEACON_TDMA)) {
  713                 (void) ieee80211_add_tdma(bo->bo_tdma, vap);
  714                 clrbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
  715         }
  716         if (ts->tdma_slot != 0)         /* only on master */
  717                 return;
  718         if (ts->tdma_count <= 0) {
  719                 /*
  720                  * Time to update the mask of active/inuse stations.
  721                  * We track stations that we've received a beacon
  722                  * frame from and update this mask periodically.
  723                  * This allows us to miss a few beacons before marking
  724                  * a slot free for re-use.
  725                  */
  726                 ts->tdma_inuse[0] = ts->tdma_active[0];
  727                 ts->tdma_active[0] = 0x01;
  728                 /* update next time 'round */
  729                 /* XXX use notify framework */
  730                 setbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
  731                 /* NB: use s/w beacon miss threshold; may be too high */
  732                 ts->tdma_count = vap->iv_bmissthreshold-1;
  733         } else
  734                 ts->tdma_count--;
  735 }
  736 
  737 static int
  738 tdma_ioctl_get80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
  739 {
  740         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  741 
  742         if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
  743                 return EOPNOTSUPP;
  744 
  745         switch (ireq->i_type) {
  746         case IEEE80211_IOC_TDMA_SLOT:
  747                 ireq->i_val = ts->tdma_slot;
  748                 break;
  749         case IEEE80211_IOC_TDMA_SLOTCNT:
  750                 ireq->i_val = ts->tdma_slotcnt;
  751                 break;
  752         case IEEE80211_IOC_TDMA_SLOTLEN:
  753                 ireq->i_val = ts->tdma_slotlen;
  754                 break;
  755         case IEEE80211_IOC_TDMA_BINTERVAL:
  756                 ireq->i_val = ts->tdma_bintval;
  757                 break;
  758         default:
  759                 return ENOSYS;
  760         }
  761         return 0;
  762 }
  763 IEEE80211_IOCTL_GET(tdma, tdma_ioctl_get80211);
  764 
  765 static int
  766 tdma_ioctl_set80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
  767 {
  768         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  769 
  770         if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
  771                 return EOPNOTSUPP;
  772 
  773         switch (ireq->i_type) {
  774         case IEEE80211_IOC_TDMA_SLOT:
  775                 if (!(0 <= ireq->i_val && ireq->i_val <= ts->tdma_slotcnt))
  776                         return EINVAL;
  777                 if (ireq->i_val != ts->tdma_slot) {
  778                         ts->tdma_slot = ireq->i_val;
  779                         goto restart;
  780                 }
  781                 break;
  782         case IEEE80211_IOC_TDMA_SLOTCNT:
  783                 if (!TDMA_SLOTCNT_VALID(ireq->i_val))
  784                         return EINVAL;
  785                 if (ireq->i_val != ts->tdma_slotcnt) {
  786                         ts->tdma_slotcnt = ireq->i_val;
  787                         goto restart;
  788                 }
  789                 break;
  790         case IEEE80211_IOC_TDMA_SLOTLEN:
  791                 /*
  792                  * XXX
  793                  * 150 insures at least 1/8 TU
  794                  * 0xfffff is the max duration for bursting
  795                  * (implict by way of 16-bit data type for i_val)
  796                  */
  797                 if (!TDMA_SLOTLEN_VALID(ireq->i_val))
  798                         return EINVAL;
  799                 if (ireq->i_val != ts->tdma_slotlen) {
  800                         ts->tdma_slotlen = ireq->i_val;
  801                         goto restart;
  802                 }
  803                 break;
  804         case IEEE80211_IOC_TDMA_BINTERVAL:
  805                 if (!TDMA_BINTVAL_VALID(ireq->i_val))
  806                         return EINVAL;
  807                 if (ireq->i_val != ts->tdma_bintval) {
  808                         ts->tdma_bintval = ireq->i_val;
  809                         goto restart;
  810                 }
  811                 break;
  812         default:
  813                 return ENOSYS;
  814         }
  815         return 0;
  816 restart:
  817         ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
  818         return ERESTART;
  819 }
  820 IEEE80211_IOCTL_SET(tdma, tdma_ioctl_set80211);

Cache object: 160e2d99b764fd1a3c7791dcc09c806b


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