The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: 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/10.0/sys/net80211/ieee80211_tdma.c 254506 2013-08-18 23:40:30Z adrian $");
   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 #ifdef  IEEE80211_SUPPORT_TDMA
   40 
   41 #include <sys/param.h>
   42 #include <sys/systm.h> 
   43 #include <sys/mbuf.h>   
   44 #include <sys/malloc.h>
   45 #include <sys/kernel.h>
   46 
   47 #include <sys/socket.h>
   48 #include <sys/sockio.h>
   49 #include <sys/endian.h>
   50 #include <sys/errno.h>
   51 #include <sys/proc.h>
   52 #include <sys/sysctl.h>
   53 
   54 #include <net/if.h>
   55 #include <net/if_media.h>
   56 #include <net/if_llc.h>
   57 #include <net/ethernet.h>
   58 
   59 #include <net/bpf.h>
   60 
   61 #include <net80211/ieee80211_var.h>
   62 #include <net80211/ieee80211_tdma.h>
   63 #include <net80211/ieee80211_input.h>
   64 
   65 #ifndef TDMA_SLOTLEN_DEFAULT
   66 #define TDMA_SLOTLEN_DEFAULT    10*1000         /* 10ms */
   67 #endif
   68 #ifndef TDMA_SLOTCNT_DEFAULT
   69 #define TDMA_SLOTCNT_DEFAULT    2               /* 2x (pt-to-pt) */
   70 #endif
   71 #ifndef TDMA_BINTVAL_DEFAULT
   72 #define TDMA_BINTVAL_DEFAULT    5               /* 5x ~= 100TU beacon intvl */
   73 #endif
   74 #ifndef TDMA_TXRATE_11B_DEFAULT
   75 #define TDMA_TXRATE_11B_DEFAULT 2*11
   76 #endif
   77 #ifndef TDMA_TXRATE_11G_DEFAULT
   78 #define TDMA_TXRATE_11G_DEFAULT 2*24
   79 #endif
   80 #ifndef TDMA_TXRATE_11A_DEFAULT
   81 #define TDMA_TXRATE_11A_DEFAULT 2*24
   82 #endif
   83 #ifndef TDMA_TXRATE_TURBO_DEFAULT
   84 #define TDMA_TXRATE_TURBO_DEFAULT       2*24
   85 #endif
   86 #ifndef TDMA_TXRATE_HALF_DEFAULT
   87 #define TDMA_TXRATE_HALF_DEFAULT        2*12
   88 #endif
   89 #ifndef TDMA_TXRATE_QUARTER_DEFAULT
   90 #define TDMA_TXRATE_QUARTER_DEFAULT     2*6
   91 #endif
   92 #ifndef TDMA_TXRATE_11NA_DEFAULT
   93 #define TDMA_TXRATE_11NA_DEFAULT        (4 | IEEE80211_RATE_MCS)
   94 #endif
   95 #ifndef TDMA_TXRATE_11NG_DEFAULT
   96 #define TDMA_TXRATE_11NG_DEFAULT        (4 | IEEE80211_RATE_MCS)
   97 #endif
   98 
   99 #define TDMA_VERSION_VALID(_version) \
  100         (TDMA_VERSION_V2 <= (_version) && (_version) <= TDMA_VERSION)
  101 #define TDMA_SLOTCNT_VALID(_slotcnt) \
  102         (2 <= (_slotcnt) && (_slotcnt) <= TDMA_MAXSLOTS)
  103 /* XXX magic constants */
  104 #define TDMA_SLOTLEN_VALID(_slotlen) \
  105         (2*100 <= (_slotlen) && (unsigned)(_slotlen) <= 0xfffff)
  106 /* XXX probably should set a max */
  107 #define TDMA_BINTVAL_VALID(_bintval)    (1 <= (_bintval))
  108 
  109 /*
  110  * This code is not prepared to handle more than 2 slots.
  111  */
  112 CTASSERT(TDMA_MAXSLOTS == 2);
  113 
  114 static void tdma_vdetach(struct ieee80211vap *vap);
  115 static int tdma_newstate(struct ieee80211vap *, enum ieee80211_state, int);
  116 static void tdma_beacon_miss(struct ieee80211vap *vap);
  117 static void tdma_recv_mgmt(struct ieee80211_node *, struct mbuf *,
  118         int subtype, int rssi, int nf);
  119 static int tdma_update(struct ieee80211vap *vap,
  120         const struct ieee80211_tdma_param *tdma, struct ieee80211_node *ni,
  121         int pickslot);
  122 static int tdma_process_params(struct ieee80211_node *ni,
  123         const u_int8_t *ie, int rssi, int nf, const struct ieee80211_frame *wh);
  124 
  125 static void
  126 settxparms(struct ieee80211vap *vap, enum ieee80211_phymode mode, int rate)
  127 {
  128         vap->iv_txparms[mode].ucastrate = rate;
  129         vap->iv_txparms[mode].mcastrate = rate;
  130 }
  131 
  132 static void
  133 setackpolicy(struct ieee80211com *ic, int noack)
  134 {
  135         struct ieee80211_wme_state *wme = &ic->ic_wme;
  136         int ac;
  137 
  138         for (ac = 0; ac < WME_NUM_AC; ac++) {
  139                 wme->wme_chanParams.cap_wmeParams[ac].wmep_noackPolicy = noack;
  140                 wme->wme_wmeChanParams.cap_wmeParams[ac].wmep_noackPolicy = noack;
  141         }
  142 }
  143 
  144 void
  145 ieee80211_tdma_vattach(struct ieee80211vap *vap)
  146 {
  147         struct ieee80211_tdma_state *ts;
  148 
  149         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  150              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  151 
  152         ts = (struct ieee80211_tdma_state *) malloc(
  153              sizeof(struct ieee80211_tdma_state), M_80211_VAP, M_NOWAIT | M_ZERO);
  154         if (ts == NULL) {
  155                 printf("%s: cannot allocate TDMA state block\n", __func__);
  156                 /* NB: fall back to adhdemo mode */
  157                 vap->iv_caps &= ~IEEE80211_C_TDMA;
  158                 return;
  159         }
  160         /* NB: default configuration is passive so no beacons */
  161         ts->tdma_version = TDMA_VERSION;
  162         ts->tdma_slotlen = TDMA_SLOTLEN_DEFAULT;
  163         ts->tdma_slotcnt = TDMA_SLOTCNT_DEFAULT;
  164         ts->tdma_bintval = TDMA_BINTVAL_DEFAULT;
  165         ts->tdma_slot = 1;                      /* passive operation */
  166 
  167         /* setup default fixed rates */
  168         settxparms(vap, IEEE80211_MODE_11A, TDMA_TXRATE_11A_DEFAULT);
  169         settxparms(vap, IEEE80211_MODE_11B, TDMA_TXRATE_11B_DEFAULT);
  170         settxparms(vap, IEEE80211_MODE_11G, TDMA_TXRATE_11G_DEFAULT);
  171         settxparms(vap, IEEE80211_MODE_TURBO_A, TDMA_TXRATE_TURBO_DEFAULT);
  172         settxparms(vap, IEEE80211_MODE_TURBO_G, TDMA_TXRATE_TURBO_DEFAULT);
  173         settxparms(vap, IEEE80211_MODE_STURBO_A, TDMA_TXRATE_TURBO_DEFAULT);
  174         settxparms(vap, IEEE80211_MODE_11NA, TDMA_TXRATE_11NA_DEFAULT);
  175         settxparms(vap, IEEE80211_MODE_11NG, TDMA_TXRATE_11NG_DEFAULT);
  176         settxparms(vap, IEEE80211_MODE_HALF, TDMA_TXRATE_HALF_DEFAULT);
  177         settxparms(vap, IEEE80211_MODE_QUARTER, TDMA_TXRATE_QUARTER_DEFAULT);
  178 
  179         setackpolicy(vap->iv_ic, 1);    /* disable ACK's */
  180 
  181         ts->tdma_opdetach = vap->iv_opdetach;
  182         vap->iv_opdetach = tdma_vdetach;
  183         ts->tdma_newstate = vap->iv_newstate;
  184         vap->iv_newstate = tdma_newstate;
  185         vap->iv_bmiss = tdma_beacon_miss;
  186         ts->tdma_recv_mgmt = vap->iv_recv_mgmt;
  187         vap->iv_recv_mgmt = tdma_recv_mgmt;
  188 
  189         vap->iv_tdma = ts;
  190 }
  191 
  192 static void
  193 tdma_vdetach(struct ieee80211vap *vap)
  194 {
  195         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  196 
  197         if (ts == NULL) {
  198                 /* NB: should not have touched any ic state */
  199                 return;
  200         }
  201         ts->tdma_opdetach(vap);
  202         free(vap->iv_tdma, M_80211_VAP);
  203         vap->iv_tdma = NULL;
  204 
  205         setackpolicy(vap->iv_ic, 0);    /* enable ACK's */
  206 }
  207 
  208 static void
  209 sta_leave(void *arg, struct ieee80211_node *ni)
  210 {
  211         struct ieee80211vap *vap = arg;
  212 
  213         if (ni->ni_vap == vap && ni != vap->iv_bss)
  214                 ieee80211_node_leave(ni);
  215 }
  216 
  217 /*
  218  * TDMA state machine handler.
  219  */
  220 static int
  221 tdma_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
  222 {
  223         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  224         struct ieee80211com *ic = vap->iv_ic;
  225         enum ieee80211_state ostate;
  226         int status;
  227 
  228         IEEE80211_LOCK_ASSERT(ic);
  229 
  230         ostate = vap->iv_state;
  231         IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
  232             __func__, ieee80211_state_name[ostate],
  233             ieee80211_state_name[nstate], arg);
  234 
  235         if (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS)
  236                 callout_stop(&vap->iv_swbmiss);
  237         if (nstate == IEEE80211_S_SCAN &&
  238             (ostate == IEEE80211_S_INIT || ostate == IEEE80211_S_RUN) &&
  239             ts->tdma_slot != 0) {
  240                 /*
  241                  * Override adhoc behaviour when operating as a slave;
  242                  * we need to scan even if the channel is locked.
  243                  */
  244                 vap->iv_state = nstate;                 /* state transition */
  245                 ieee80211_cancel_scan(vap);             /* background scan */
  246                 if (ostate == IEEE80211_S_RUN) {
  247                         /* purge station table; entries are stale */
  248                         ieee80211_iterate_nodes(&ic->ic_sta, sta_leave, vap);
  249                 }
  250                 if (vap->iv_flags_ext & IEEE80211_FEXT_SCANREQ) {
  251                         ieee80211_check_scan(vap,
  252                             vap->iv_scanreq_flags,
  253                             vap->iv_scanreq_duration,
  254                             vap->iv_scanreq_mindwell,
  255                             vap->iv_scanreq_maxdwell,
  256                             vap->iv_scanreq_nssid, vap->iv_scanreq_ssid);
  257                         vap->iv_flags_ext &= ~IEEE80211_FEXT_SCANREQ;
  258                 } else
  259                         ieee80211_check_scan_current(vap);
  260                 status = 0;
  261         } else {
  262                 status = ts->tdma_newstate(vap, nstate, arg);
  263         }
  264         if (status == 0 && 
  265             nstate == IEEE80211_S_RUN && ostate != IEEE80211_S_RUN &&
  266             (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS) &&
  267             ts->tdma_slot != 0 &&
  268             vap->iv_des_chan == IEEE80211_CHAN_ANYC) {
  269                 /*
  270                  * Start s/w beacon miss timer for slave devices w/o
  271                  * hardware support.  Note we do this only if we're
  272                  * not locked to a channel (i.e. roam to follow the
  273                  * master). The 2x is a fudge for our doing this in
  274                  * software.
  275                  */
  276                 vap->iv_swbmiss_period = IEEE80211_TU_TO_TICKS(
  277                     2 * vap->iv_bmissthreshold * ts->tdma_bintval *
  278                     ((ts->tdma_slotcnt * ts->tdma_slotlen) / 1024));
  279                 vap->iv_swbmiss_count = 0;
  280                 callout_reset(&vap->iv_swbmiss, vap->iv_swbmiss_period,
  281                         ieee80211_swbmiss, vap);
  282         }
  283         return status;
  284 }
  285 
  286 static void
  287 tdma_beacon_miss(struct ieee80211vap *vap)
  288 {
  289         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  290 
  291         IEEE80211_LOCK_ASSERT(vap->iv_ic);
  292 
  293         KASSERT((vap->iv_ic->ic_flags & IEEE80211_F_SCAN) == 0, ("scanning"));
  294         KASSERT(vap->iv_state == IEEE80211_S_RUN,
  295             ("wrong state %d", vap->iv_state));
  296 
  297         IEEE80211_DPRINTF(vap,
  298                 IEEE80211_MSG_STATE | IEEE80211_MSG_TDMA | IEEE80211_MSG_DEBUG,
  299                 "beacon miss, mode %u state %s\n",
  300                 vap->iv_opmode, ieee80211_state_name[vap->iv_state]);
  301 
  302         callout_stop(&vap->iv_swbmiss);
  303 
  304         if (ts->tdma_peer != NULL) {    /* XXX? can this be null? */
  305                 ieee80211_notify_node_leave(vap->iv_bss);
  306                 ts->tdma_peer = NULL;
  307                 /*
  308                  * Treat beacon miss like an associate failure wrt the
  309                  * scan policy; this forces the entry in the scan cache
  310                  * to be ignored after several tries.
  311                  */
  312                 ieee80211_scan_assoc_fail(vap, vap->iv_bss->ni_macaddr,
  313                     IEEE80211_STATUS_TIMEOUT);
  314         }
  315 #if 0
  316         ts->tdma_inuse = 0;             /* clear slot usage */
  317 #endif
  318         ieee80211_new_state(vap, IEEE80211_S_SCAN, 0);
  319 }
  320 
  321 static void
  322 tdma_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
  323         int subtype, int rssi, int nf)
  324 {
  325         struct ieee80211com *ic = ni->ni_ic;
  326         struct ieee80211vap *vap = ni->ni_vap;
  327         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  328 
  329         if (subtype == IEEE80211_FC0_SUBTYPE_BEACON &&
  330             (ic->ic_flags & IEEE80211_F_SCAN) == 0) {
  331                 struct ieee80211_frame *wh = mtod(m0, struct ieee80211_frame *);
  332                 struct ieee80211_scanparams scan;
  333 
  334                 if (ieee80211_parse_beacon(ni, m0, &scan) != 0)
  335                         return;
  336                 if (scan.tdma == NULL) {
  337                         /*
  338                          * TDMA stations must beacon a TDMA ie; ignore
  339                          * any other station.
  340                          * XXX detect overlapping bss and change channel
  341                          */
  342                         IEEE80211_DISCARD(vap,
  343                             IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
  344                             wh, ieee80211_mgt_subtype_name[subtype >>
  345                                 IEEE80211_FC0_SUBTYPE_SHIFT],
  346                             "%s", "no TDMA ie");
  347                         vap->iv_stats.is_rx_mgtdiscard++;
  348                         return;
  349                 }
  350                 if (ni == vap->iv_bss &&
  351                     !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
  352                         /*
  353                          * Fake up a node for this newly
  354                          * discovered member of the IBSS.
  355                          */
  356                         ni = ieee80211_add_neighbor(vap, wh, &scan);
  357                         if (ni == NULL) {
  358                                 /* NB: stat kept for alloc failure */
  359                                 return;
  360                         }
  361                 }
  362                 /*
  363                  * Check for state updates.
  364                  */
  365                 if (IEEE80211_ADDR_EQ(wh->i_addr3, ni->ni_bssid)) {
  366                         /*
  367                          * Count frame now that we know it's to be processed.
  368                          */
  369                         vap->iv_stats.is_rx_beacon++;
  370                         IEEE80211_NODE_STAT(ni, rx_beacons);
  371                         /*
  372                          * Record tsf of last beacon.  NB: this must be
  373                          * done before calling tdma_process_params
  374                          * as deeper routines reference it.
  375                          */
  376                         memcpy(&ni->ni_tstamp.data, scan.tstamp,
  377                                 sizeof(ni->ni_tstamp.data));
  378                         /*
  379                          * Count beacon frame for s/w bmiss handling.
  380                          */
  381                         vap->iv_swbmiss_count++;
  382                         /*
  383                          * Process tdma ie.  The contents are used to sync
  384                          * the slot timing, reconfigure the bss, etc.
  385                          */
  386                         (void) tdma_process_params(ni, scan.tdma, rssi, nf, wh);
  387                         return;
  388                 }
  389                 /*
  390                  * NB: defer remaining work to the adhoc code; this causes
  391                  *     2x parsing of the frame but should happen infrequently
  392                  */
  393         }
  394         ts->tdma_recv_mgmt(ni, m0, subtype, rssi, nf);
  395 }
  396 
  397 /*
  398  * Update TDMA state on receipt of a beacon frame with
  399  * a TDMA information element.  The sender's identity
  400  * is provided so we can track who our peer is.  If pickslot
  401  * is non-zero we scan the slot allocation state in the ie
  402  * to locate a free slot for our use.
  403  */
  404 static int
  405 tdma_update(struct ieee80211vap *vap, const struct ieee80211_tdma_param *tdma,
  406         struct ieee80211_node *ni, int pickslot)
  407 {
  408         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  409         int slot, slotlen, update;
  410 
  411         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  412              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  413 
  414         update = 0;
  415         if (tdma->tdma_slotcnt != ts->tdma_slotcnt) {
  416                 if (!TDMA_SLOTCNT_VALID(tdma->tdma_slotcnt)) {
  417                         if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
  418                                 printf("%s: bad slot cnt %u\n",
  419                                     __func__, tdma->tdma_slotcnt);
  420                         return 0;
  421                 }
  422                 update |= TDMA_UPDATE_SLOTCNT;
  423         }
  424         slotlen = le16toh(tdma->tdma_slotlen) * 100;
  425         if (slotlen != ts->tdma_slotlen) {
  426                 if (!TDMA_SLOTLEN_VALID(slotlen)) {
  427                         if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
  428                                 printf("%s: bad slot len %u\n",
  429                                     __func__, slotlen);
  430                         return 0;
  431                 }
  432                 update |= TDMA_UPDATE_SLOTLEN;
  433         }
  434         if (tdma->tdma_bintval != ts->tdma_bintval) {
  435                 if (!TDMA_BINTVAL_VALID(tdma->tdma_bintval)) {
  436                         if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
  437                                 printf("%s: bad beacon interval %u\n",
  438                                     __func__, tdma->tdma_bintval);
  439                         return 0;
  440                 }
  441                 update |= TDMA_UPDATE_BINTVAL;
  442         }
  443         slot = ts->tdma_slot;
  444         if (pickslot) {
  445                 /*
  446                  * Pick unoccupied slot.  Note we never choose slot 0.
  447                  */
  448                 for (slot = tdma->tdma_slotcnt-1; slot > 0; slot--)
  449                         if (isclr(tdma->tdma_inuse, slot))
  450                                 break;
  451                 if (slot <= 0) {
  452                         printf("%s: no free slot, slotcnt %u inuse: 0x%x\n",
  453                                 __func__, tdma->tdma_slotcnt,
  454                                 tdma->tdma_inuse[0]);
  455                         /* XXX need to do something better */
  456                         return 0;
  457                 }
  458                 if (slot != ts->tdma_slot)
  459                         update |= TDMA_UPDATE_SLOT;
  460         }
  461         if (ni != ts->tdma_peer) {
  462                 /* update everything */
  463                 update = TDMA_UPDATE_SLOT
  464                        | TDMA_UPDATE_SLOTCNT
  465                        | TDMA_UPDATE_SLOTLEN
  466                        | TDMA_UPDATE_BINTVAL;
  467         }
  468 
  469         if (update) {
  470                 /*
  471                  * New/changed parameters; update runtime state.
  472                  */
  473                 /* XXX overwrites user parameters */
  474                 if (update & TDMA_UPDATE_SLOTCNT)
  475                         ts->tdma_slotcnt = tdma->tdma_slotcnt;
  476                 if (update & TDMA_UPDATE_SLOTLEN)
  477                         ts->tdma_slotlen = slotlen;
  478                 if (update & TDMA_UPDATE_SLOT)
  479                         ts->tdma_slot = slot;
  480                 if (update & TDMA_UPDATE_BINTVAL)
  481                         ts->tdma_bintval = tdma->tdma_bintval;
  482                 /* mark beacon to be updated before next xmit */
  483                 ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
  484 
  485                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
  486                     "%s: slot %u slotcnt %u slotlen %u us bintval %u\n",
  487                     __func__, ts->tdma_slot, ts->tdma_slotcnt,
  488                     ts->tdma_slotlen, ts->tdma_bintval);
  489         }
  490         /*
  491          * Notify driver.  Note we can be called before
  492          * entering RUN state if we scanned and are
  493          * joining an existing bss.  In that case do not
  494          * call the driver because not all necessary state
  495          * has been setup.  The next beacon will dtrt.
  496          */
  497         if (vap->iv_state == IEEE80211_S_RUN)
  498                 vap->iv_ic->ic_tdma_update(ni, tdma, update);
  499         /*
  500          * Dispatch join event on first beacon from new master.
  501          */
  502         if (ts->tdma_peer != ni) {
  503                 if (ts->tdma_peer != NULL)
  504                         ieee80211_notify_node_leave(vap->iv_bss);
  505                 ieee80211_notify_node_join(ni, 1);
  506                 /* NB: no reference, we just use the address */
  507                 ts->tdma_peer = ni;
  508         }
  509         return 1;
  510 }
  511 
  512 /*
  513  * Process received TDMA parameters.
  514  */
  515 static int
  516 tdma_process_params(struct ieee80211_node *ni, const u_int8_t *ie,
  517         int rssi, int nf, const struct ieee80211_frame *wh)
  518 {
  519         struct ieee80211vap *vap = ni->ni_vap;
  520         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  521         const struct ieee80211_tdma_param *tdma = 
  522                 (const struct ieee80211_tdma_param *) ie;
  523         u_int len = ie[1];
  524 
  525         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  526              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  527 
  528         if (len < sizeof(*tdma) - 2) {
  529                 IEEE80211_DISCARD_IE(vap,
  530                     IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
  531                     wh, "tdma", "too short, len %u", len);
  532                 return IEEE80211_REASON_IE_INVALID;
  533         }
  534         if (tdma->tdma_version != ts->tdma_version) {
  535                 IEEE80211_DISCARD_IE(vap,
  536                     IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
  537                     wh, "tdma", "bad version %u (ours %u)",
  538                     tdma->tdma_version, ts->tdma_version);
  539                 return IEEE80211_REASON_IE_INVALID;
  540         }
  541         /*
  542          * NB: ideally we'd check against tdma_slotcnt, but that
  543          * would require extra effort so do this easy check that
  544          * covers the work below; more stringent checks are done
  545          * before we make more extensive use of the ie contents.
  546          */
  547         if (tdma->tdma_slot >= TDMA_MAXSLOTS) {
  548                 IEEE80211_DISCARD_IE(vap,
  549                     IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
  550                     wh, "tdma", "invalid slot %u", tdma->tdma_slot);
  551                 return IEEE80211_REASON_IE_INVALID;
  552         }
  553         /*
  554          * Can reach here while scanning, update
  555          * operational state only in RUN state.
  556          */
  557         if (vap->iv_state == IEEE80211_S_RUN) {
  558                 if (tdma->tdma_slot != ts->tdma_slot &&
  559                     isclr(ts->tdma_inuse, tdma->tdma_slot)) {
  560                         IEEE80211_NOTE(vap, IEEE80211_MSG_TDMA, ni,
  561                             "discovered in slot %u", tdma->tdma_slot);
  562                         setbit(ts->tdma_inuse, tdma->tdma_slot);
  563                         /* XXX dispatch event only when operating as master */
  564                         if (ts->tdma_slot == 0)
  565                                 ieee80211_notify_node_join(ni, 1);
  566                 }
  567                 setbit(ts->tdma_active, tdma->tdma_slot);
  568                 if (tdma->tdma_slot == ts->tdma_slot-1) {
  569                         /*
  570                          * Slave tsf synchronization to station
  571                          * just before us in the schedule. The driver
  572                          * is responsible for copying the timestamp
  573                          * of the received beacon into our beacon
  574                          * frame so the sender can calculate round
  575                          * trip time.  We cannot do that here because
  576                          * we don't know how to update our beacon frame.
  577                          */
  578                         (void) tdma_update(vap, tdma, ni, 0);
  579                         /* XXX reschedule swbmiss timer on parameter change */
  580                 } else if (tdma->tdma_slot == ts->tdma_slot+1) {
  581                         uint64_t tstamp;
  582 #if 0
  583                         uint32_t rstamp = (uint32_t) le64toh(rs->tsf);
  584                         int32_t rtt;
  585 #endif
  586                         /*
  587                          * Use returned timstamp to calculate the
  588                          * roundtrip time.
  589                          */
  590                         memcpy(&tstamp, tdma->tdma_tstamp, 8);
  591 #if 0
  592                         /* XXX use only 15 bits of rstamp */
  593                         rtt = rstamp - (le64toh(tstamp) & 0x7fff);
  594                         if (rtt < 0)
  595                                 rtt += 0x7fff;
  596                         /* XXX hack to quiet normal use */
  597                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOT1X,
  598                             "tdma rtt %5u [rstamp %5u tstamp %llu]\n",
  599                             rtt, rstamp,
  600                             (unsigned long long) le64toh(tstamp));
  601 #endif
  602                 } else if (tdma->tdma_slot == ts->tdma_slot &&
  603                     le64toh(ni->ni_tstamp.tsf) > vap->iv_bss->ni_tstamp.tsf) {
  604                         /*
  605                          * Station using the same slot as us and has
  606                          * been around longer than us; we must move.
  607                          * Note this can happen if stations do not
  608                          * see each other while scanning.
  609                          */
  610                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
  611                             "slot %u collision rxtsf %llu tsf %llu\n",
  612                             tdma->tdma_slot,
  613                             (unsigned long long) le64toh(ni->ni_tstamp.tsf),
  614                             vap->iv_bss->ni_tstamp.tsf);
  615                         setbit(ts->tdma_inuse, tdma->tdma_slot);
  616 
  617                         (void) tdma_update(vap, tdma, ni, 1);
  618                 }
  619         }
  620         return 0;
  621 }
  622 
  623 int
  624 ieee80211_tdma_getslot(struct ieee80211vap *vap)
  625 {
  626         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  627 
  628         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  629              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  630         return ts->tdma_slot;
  631 }
  632 
  633 /*
  634  * Parse a TDMA ie on station join and use it to setup node state.
  635  */
  636 void
  637 ieee80211_parse_tdma(struct ieee80211_node *ni, const uint8_t *ie)
  638 {
  639         struct ieee80211vap *vap = ni->ni_vap;
  640 
  641         if (vap->iv_caps & IEEE80211_C_TDMA) {
  642                 const struct ieee80211_tdma_param *tdma =
  643                     (const struct ieee80211_tdma_param *)ie;
  644                 struct ieee80211_tdma_state *ts = vap->iv_tdma;
  645                 /*
  646                  * Adopt TDMA configuration when joining an
  647                  * existing network.
  648                  */
  649                 setbit(ts->tdma_inuse, tdma->tdma_slot);
  650                 (void) tdma_update(vap, tdma, ni, 1);
  651                 /*
  652                  * Propagate capabilities based on the local
  653                  * configuration and the remote station's advertised
  654                  * capabilities. In particular this permits us to
  655                  * enable use of QoS to disable ACK's.
  656                  */
  657                 if ((vap->iv_flags & IEEE80211_F_WME) &&
  658                     ni->ni_ies.wme_ie != NULL)
  659                         ni->ni_flags |= IEEE80211_NODE_QOS;
  660         }
  661 }
  662 
  663 #define TDMA_OUI_BYTES          0x00, 0x03, 0x7f
  664 /*
  665  * Add a TDMA parameters element to a frame.
  666  */
  667 uint8_t *
  668 ieee80211_add_tdma(uint8_t *frm, struct ieee80211vap *vap)
  669 {
  670 #define ADDSHORT(frm, v) do {                   \
  671         frm[0] = (v) & 0xff;                    \
  672         frm[1] = (v) >> 8;                      \
  673         frm += 2;                               \
  674 } while (0)
  675         static const struct ieee80211_tdma_param param = {
  676                 .tdma_id        = IEEE80211_ELEMID_VENDOR,
  677                 .tdma_len       = sizeof(struct ieee80211_tdma_param) - 2,
  678                 .tdma_oui       = { TDMA_OUI_BYTES },
  679                 .tdma_type      = TDMA_OUI_TYPE,
  680                 .tdma_subtype   = TDMA_SUBTYPE_PARAM,
  681                 .tdma_version   = TDMA_VERSION,
  682         };
  683         const struct ieee80211_tdma_state *ts = vap->iv_tdma;
  684         uint16_t slotlen;
  685 
  686         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  687              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  688 
  689         memcpy(frm, &param, sizeof(param));
  690         frm += __offsetof(struct ieee80211_tdma_param, tdma_slot);
  691         *frm++ = ts->tdma_slot;
  692         *frm++ = ts->tdma_slotcnt;
  693         /* NB: convert units to fit in 16-bits */
  694         slotlen = ts->tdma_slotlen / 100;       /* 100us units */
  695         ADDSHORT(frm, slotlen);
  696         *frm++ = ts->tdma_bintval;
  697         *frm++ = ts->tdma_inuse[0];
  698         frm += 10;                              /* pad+timestamp */
  699         return frm; 
  700 #undef ADDSHORT
  701 }
  702 #undef TDMA_OUI_BYTES
  703 
  704 /*
  705  * Update TDMA state at TBTT.
  706  */
  707 void
  708 ieee80211_tdma_update_beacon(struct ieee80211vap *vap,
  709         struct ieee80211_beacon_offsets *bo)
  710 {
  711         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  712 
  713         KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
  714              ("not a tdma vap, caps 0x%x", vap->iv_caps));
  715 
  716         if (isset(bo->bo_flags,  IEEE80211_BEACON_TDMA)) {
  717                 (void) ieee80211_add_tdma(bo->bo_tdma, vap);
  718                 clrbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
  719         }
  720         if (ts->tdma_slot != 0)         /* only on master */
  721                 return;
  722         if (ts->tdma_count <= 0) {
  723                 /*
  724                  * Time to update the mask of active/inuse stations.
  725                  * We track stations that we've received a beacon
  726                  * frame from and update this mask periodically.
  727                  * This allows us to miss a few beacons before marking
  728                  * a slot free for re-use.
  729                  */
  730                 ts->tdma_inuse[0] = ts->tdma_active[0];
  731                 ts->tdma_active[0] = 0x01;
  732                 /* update next time 'round */
  733                 /* XXX use notify framework */
  734                 setbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
  735                 /* NB: use s/w beacon miss threshold; may be too high */
  736                 ts->tdma_count = vap->iv_bmissthreshold-1;
  737         } else
  738                 ts->tdma_count--;
  739 }
  740 
  741 static int
  742 tdma_ioctl_get80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
  743 {
  744         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  745 
  746         if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
  747                 return ENOSYS;
  748 
  749         switch (ireq->i_type) {
  750         case IEEE80211_IOC_TDMA_SLOT:
  751                 ireq->i_val = ts->tdma_slot;
  752                 break;
  753         case IEEE80211_IOC_TDMA_SLOTCNT:
  754                 ireq->i_val = ts->tdma_slotcnt;
  755                 break;
  756         case IEEE80211_IOC_TDMA_SLOTLEN:
  757                 ireq->i_val = ts->tdma_slotlen;
  758                 break;
  759         case IEEE80211_IOC_TDMA_BINTERVAL:
  760                 ireq->i_val = ts->tdma_bintval;
  761                 break;
  762         default:
  763                 return ENOSYS;
  764         }
  765         return 0;
  766 }
  767 IEEE80211_IOCTL_GET(tdma, tdma_ioctl_get80211);
  768 
  769 static int
  770 tdma_ioctl_set80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
  771 {
  772         struct ieee80211_tdma_state *ts = vap->iv_tdma;
  773 
  774         if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
  775                 return ENOSYS;
  776 
  777         switch (ireq->i_type) {
  778         case IEEE80211_IOC_TDMA_SLOT:
  779                 if (!(0 <= ireq->i_val && ireq->i_val <= ts->tdma_slotcnt))
  780                         return EINVAL;
  781                 if (ireq->i_val != ts->tdma_slot) {
  782                         ts->tdma_slot = ireq->i_val;
  783                         goto restart;
  784                 }
  785                 break;
  786         case IEEE80211_IOC_TDMA_SLOTCNT:
  787                 if (!TDMA_SLOTCNT_VALID(ireq->i_val))
  788                         return EINVAL;
  789                 if (ireq->i_val != ts->tdma_slotcnt) {
  790                         ts->tdma_slotcnt = ireq->i_val;
  791                         goto restart;
  792                 }
  793                 break;
  794         case IEEE80211_IOC_TDMA_SLOTLEN:
  795                 /*
  796                  * XXX
  797                  * 150 insures at least 1/8 TU
  798                  * 0xfffff is the max duration for bursting
  799                  * (implict by way of 16-bit data type for i_val)
  800                  */
  801                 if (!TDMA_SLOTLEN_VALID(ireq->i_val))
  802                         return EINVAL;
  803                 if (ireq->i_val != ts->tdma_slotlen) {
  804                         ts->tdma_slotlen = ireq->i_val;
  805                         goto restart;
  806                 }
  807                 break;
  808         case IEEE80211_IOC_TDMA_BINTERVAL:
  809                 if (!TDMA_BINTVAL_VALID(ireq->i_val))
  810                         return EINVAL;
  811                 if (ireq->i_val != ts->tdma_bintval) {
  812                         ts->tdma_bintval = ireq->i_val;
  813                         goto restart;
  814                 }
  815                 break;
  816         default:
  817                 return ENOSYS;
  818         }
  819         return 0;
  820 restart:
  821         ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
  822         return ERESTART;
  823 }
  824 IEEE80211_IOCTL_SET(tdma, tdma_ioctl_set80211);
  825 
  826 #endif  /* IEEE80211_SUPPORT_TDMA */

Cache object: ab6d3bb8aea7aae4bf3cc226d4ad6f71


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