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


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

FreeBSD/Linux Kernel Cross Reference
sys/net80211/ieee80211_node.c

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

    1 /*      $NetBSD: ieee80211_node.c,v 1.38 2005/02/26 22:45:09 perry Exp $        */
    2 /*-
    3  * Copyright (c) 2001 Atsushi Onoe
    4  * Copyright (c) 2002-2004 Sam Leffler, Errno Consulting
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 3. The name of the author may not be used to endorse or promote products
   16  *    derived from this software without specific prior written permission.
   17  *
   18  * Alternatively, this software may be distributed under the terms of the
   19  * GNU General Public License ("GPL") version 2 as published by the Free
   20  * Software Foundation.
   21  *
   22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   32  */
   33 
   34 #include <sys/cdefs.h>
   35 #ifdef __FreeBSD__
   36 __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_node.c,v 1.22 2004/04/05 04:15:55 sam Exp $");
   37 #else
   38 __KERNEL_RCSID(0, "$NetBSD: ieee80211_node.c,v 1.38 2005/02/26 22:45:09 perry Exp $");
   39 #endif
   40 
   41 #include "opt_inet.h"
   42 
   43 #include <sys/param.h>
   44 #include <sys/systm.h>
   45 #include <sys/mbuf.h>
   46 #include <sys/malloc.h>
   47 #include <sys/kernel.h>
   48 #include <sys/socket.h>
   49 #include <sys/sockio.h>
   50 #include <sys/endian.h>
   51 #include <sys/errno.h>
   52 #ifdef __FreeBSD__
   53 #include <sys/bus.h>
   54 #endif
   55 #include <sys/proc.h>
   56 #include <sys/sysctl.h>
   57 
   58 #ifdef __FreeBSD__
   59 #include <machine/atomic.h>
   60 #endif
   61 
   62 #include <net/if.h>
   63 #include <net/if_dl.h>
   64 #include <net/if_media.h>
   65 #include <net/if_arp.h>
   66 #ifdef __FreeBSD__
   67 #include <net/ethernet.h>
   68 #else
   69 #include <net/if_ether.h>
   70 #endif
   71 #include <net/if_llc.h>
   72 
   73 #include <net80211/ieee80211_var.h>
   74 #include <net80211/ieee80211_compat.h>
   75 
   76 #include <net/bpf.h>
   77 
   78 #ifdef INET
   79 #include <netinet/in.h>
   80 #ifdef __FreeBSD__
   81 #include <netinet/if_ether.h>
   82 #else
   83 #include <net/if_ether.h>
   84 #endif
   85 #endif
   86 
   87 static struct ieee80211_node *ieee80211_node_alloc(struct ieee80211com *);
   88 static void ieee80211_node_free(struct ieee80211com *, struct ieee80211_node *);
   89 static void ieee80211_node_copy(struct ieee80211com *,
   90                 struct ieee80211_node *, const struct ieee80211_node *);
   91 static u_int8_t ieee80211_node_getrssi(struct ieee80211com *,
   92                 struct ieee80211_node *);
   93 
   94 static void ieee80211_setup_node(struct ieee80211com *ic,
   95                 struct ieee80211_node *ni, u_int8_t *macaddr);
   96 static void ieee80211_free_node(struct ieee80211com *,
   97                 struct ieee80211_node *);
   98 
   99 MALLOC_DEFINE(M_80211_NODE, "80211node", "802.11 node state");
  100 
  101 void
  102 ieee80211_node_attach(struct ieee80211com *ic)
  103 {
  104 
  105         /* XXX need unit */
  106         IEEE80211_NODE_LOCK_INIT(ic, ic->ic_ifp->if_xname);
  107         TAILQ_INIT(&ic->ic_node);
  108         ic->ic_node_alloc = ieee80211_node_alloc;
  109         ic->ic_node_free = ieee80211_node_free;
  110         ic->ic_node_copy = ieee80211_node_copy;
  111         ic->ic_node_getrssi = ieee80211_node_getrssi;
  112         ic->ic_scangen = 1;
  113         ic->ic_max_nnodes = ieee80211_cache_size;
  114 
  115         if (ic->ic_max_aid == 0)
  116                 ic->ic_max_aid = IEEE80211_AID_DEF;
  117         else if (ic->ic_max_aid > IEEE80211_AID_MAX)
  118                 ic->ic_max_aid = IEEE80211_AID_MAX;
  119         MALLOC(ic->ic_aid_bitmap, u_int32_t *,
  120                 howmany(ic->ic_max_aid, 32) * sizeof(u_int32_t),
  121                 M_DEVBUF, M_NOWAIT | M_ZERO);
  122         if (ic->ic_aid_bitmap == NULL) {
  123                 /* XXX no way to recover */
  124                 printf("%s: no memory for AID bitmap!\n", __func__);
  125                 ic->ic_max_aid = 0;
  126         }
  127 }
  128 
  129 static struct ieee80211_node *
  130 ieee80211_alloc_node_helper(struct ieee80211com *ic)
  131 {
  132         struct ieee80211_node *ni;
  133         if (ic->ic_nnodes >= ic->ic_max_nnodes)
  134                 ieee80211_clean_nodes(ic);
  135         if (ic->ic_nnodes >= ic->ic_max_nnodes)
  136                 return NULL;
  137         ni = (*ic->ic_node_alloc)(ic);
  138         if (ni != NULL)
  139                 ic->ic_nnodes++;
  140         return ni;
  141 }
  142 
  143 void
  144 ieee80211_node_lateattach(struct ieee80211com *ic)
  145 {
  146         struct ieee80211_node *ni;
  147 
  148         ni = ieee80211_alloc_node_helper(ic);
  149         IASSERT(ni != NULL, ("unable to setup inital BSS node"));
  150         ni->ni_chan = IEEE80211_CHAN_ANYC;
  151         ic->ic_bss = ieee80211_ref_node(ni);
  152         ic->ic_txpower = IEEE80211_TXPOWER_MAX;
  153 }
  154 
  155 void
  156 ieee80211_node_detach(struct ieee80211com *ic)
  157 {
  158 
  159         if (ic->ic_bss != NULL) {
  160                 (*ic->ic_node_free)(ic, ic->ic_bss);
  161                 ic->ic_bss = NULL;
  162         }
  163         ieee80211_free_allnodes(ic);
  164         IEEE80211_NODE_LOCK_DESTROY(ic);
  165         if (ic->ic_aid_bitmap != NULL)
  166                 FREE(ic->ic_aid_bitmap, M_DEVBUF);
  167 }
  168 
  169 /*
  170  * AP scanning support.
  171  */
  172 
  173 /*
  174  * Initialize the active channel set based on the set
  175  * of available channels and the current PHY mode.
  176  */
  177 static void
  178 ieee80211_reset_scan(struct ieee80211com *ic)
  179 {
  180 
  181         memcpy(ic->ic_chan_scan, ic->ic_chan_active,
  182                 sizeof(ic->ic_chan_active));
  183         /* NB: hack, setup so next_scan starts with the first channel */
  184         if (ic->ic_bss->ni_chan == IEEE80211_CHAN_ANYC)
  185                 ic->ic_bss->ni_chan = &ic->ic_channels[IEEE80211_CHAN_MAX];
  186 }
  187 
  188 /*
  189  * Begin an active scan.
  190  */
  191 void
  192 ieee80211_begin_scan(struct ieee80211com *ic)
  193 {
  194 
  195         /*
  196          * In all but hostap mode scanning starts off in
  197          * an active mode before switching to passive.
  198          */
  199         if (ic->ic_opmode != IEEE80211_M_HOSTAP) {
  200                 ic->ic_flags |= IEEE80211_F_ASCAN;
  201                 ic->ic_stats.is_scan_active++;
  202         } else
  203                 ic->ic_stats.is_scan_passive++;
  204         IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN, ("begin %s scan\n",
  205                 (ic->ic_flags & IEEE80211_F_ASCAN) ?  "active" : "passive"));
  206         /*
  207          * Clear scan state and flush any previously seen
  208          * AP's.  Note that the latter assumes we don't act
  209          * as both an AP and a station, otherwise we'll
  210          * potentially flush state of stations associated
  211          * with us.
  212          */
  213         ieee80211_reset_scan(ic);
  214         ieee80211_free_allnodes(ic);
  215 
  216         /* Scan the next channel. */
  217         ieee80211_next_scan(ic);
  218 }
  219 
  220 /*
  221  * Switch to the next channel marked for scanning.
  222  */
  223 void
  224 ieee80211_next_scan(struct ieee80211com *ic)
  225 {
  226         struct ieee80211_channel *chan;
  227 
  228         chan = ic->ic_bss->ni_chan;
  229         for (;;) {
  230                 if (++chan > &ic->ic_channels[IEEE80211_CHAN_MAX])
  231                         chan = &ic->ic_channels[0];
  232                 if (isset(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan))) {
  233                         /*
  234                          * Honor channels marked passive-only
  235                          * during an active scan.
  236                          */
  237                         if ((ic->ic_flags & IEEE80211_F_ASCAN) == 0 ||
  238                             (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0)
  239                                 break;
  240                 }
  241                 if (chan == ic->ic_bss->ni_chan) {
  242                         ieee80211_end_scan(ic);
  243                         return;
  244                 }
  245         }
  246         clrbit(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan));
  247         IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN,
  248                 ("%s: chan %d->%d\n", __func__,
  249                 ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan),
  250                 ieee80211_chan2ieee(ic, chan)));
  251         ic->ic_bss->ni_chan = chan;
  252         ieee80211_new_state(ic, IEEE80211_S_SCAN, -1);
  253 }
  254 
  255 void
  256 ieee80211_create_ibss(struct ieee80211com* ic, struct ieee80211_channel *chan)
  257 {
  258         struct ieee80211_node *ni;
  259 
  260         ni = ic->ic_bss;
  261         ic->ic_flags |= IEEE80211_F_SIBSS;
  262         ni->ni_chan = chan;
  263         ni->ni_rates = ic->ic_sup_rates[ieee80211_chan2mode(ic, ni->ni_chan)];
  264         IEEE80211_ADDR_COPY(ni->ni_macaddr, ic->ic_myaddr);
  265         IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_myaddr);
  266         if (ic->ic_opmode == IEEE80211_M_IBSS) {
  267                 if ((ic->ic_flags & IEEE80211_F_DESBSSID) != 0)
  268                         IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_des_bssid);
  269                 else
  270                         ni->ni_bssid[0] |= 0x02;        /* local bit for IBSS */
  271         }
  272         if_printf(&ic->ic_if, "creating bss %s\n", ether_sprintf(ni->ni_bssid));
  273         ni->ni_esslen = ic->ic_des_esslen;
  274         memcpy(ni->ni_essid, ic->ic_des_essid, ni->ni_esslen);
  275         ni->ni_rssi = 0;
  276         ni->ni_rstamp = 0;
  277         memset(ni->ni_tstamp, 0, sizeof(ni->ni_tstamp));
  278         ni->ni_intval = ic->ic_lintval;
  279         ni->ni_capinfo = IEEE80211_CAPINFO_IBSS;
  280         if (ic->ic_flags & IEEE80211_F_PRIVACY)
  281                 ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY;
  282         if (ic->ic_phytype == IEEE80211_T_FH) {
  283                 ni->ni_fhdwell = 200;   /* XXX */
  284                 ni->ni_fhindex = 1;
  285         }
  286         ieee80211_new_state(ic, IEEE80211_S_RUN, -1);
  287 }
  288 
  289 int
  290 ieee80211_match_bss(struct ieee80211com *ic, struct ieee80211_node *ni)
  291 {
  292         u_int8_t rate;
  293         int fail;
  294 
  295         fail = 0;
  296         if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan)))
  297                 fail |= 0x01;
  298         if (ic->ic_des_chan != IEEE80211_CHAN_ANYC &&
  299             ni->ni_chan != ic->ic_des_chan)
  300                 fail |= 0x01;
  301         if (ic->ic_opmode == IEEE80211_M_IBSS) {
  302                 if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
  303                         fail |= 0x02;
  304         } else {
  305                 if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0)
  306                         fail |= 0x02;
  307         }
  308         if (ic->ic_flags & IEEE80211_F_PRIVACY) {
  309                 if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
  310                         fail |= 0x04;
  311         } else {
  312                 /* XXX does this mean privacy is supported or required? */
  313                 if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY)
  314                         fail |= 0x04;
  315         }
  316         rate = ieee80211_fix_rate(ic, ni, IEEE80211_F_DONEGO);
  317         if (rate & IEEE80211_RATE_BASIC)
  318                 fail |= 0x08;
  319         if (ic->ic_des_esslen != 0 &&
  320             (ni->ni_esslen != ic->ic_des_esslen ||
  321              memcmp(ni->ni_essid, ic->ic_des_essid, ic->ic_des_esslen) != 0))
  322                 fail |= 0x10;
  323         if ((ic->ic_flags & IEEE80211_F_DESBSSID) &&
  324             !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid))
  325                 fail |= 0x20;
  326 #ifdef IEEE80211_DEBUG
  327         if (ic->ic_if.if_flags & IFF_DEBUG) {
  328                 printf(" %c %s", fail ? '-' : '+',
  329                     ether_sprintf(ni->ni_macaddr));
  330                 printf(" %s%c", ether_sprintf(ni->ni_bssid),
  331                     fail & 0x20 ? '!' : ' ');
  332                 printf(" %3d%c", ieee80211_chan2ieee(ic, ni->ni_chan),
  333                         fail & 0x01 ? '!' : ' ');
  334                 printf(" %+4d", ni->ni_rssi);
  335                 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
  336                     fail & 0x08 ? '!' : ' ');
  337                 printf(" %4s%c",
  338                     (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
  339                     (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" :
  340                     "????",
  341                     fail & 0x02 ? '!' : ' ');
  342                 printf(" %3s%c ",
  343                     (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ?
  344                     "wep" : "no",
  345                     fail & 0x04 ? '!' : ' ');
  346                 ieee80211_print_essid(ni->ni_essid, ni->ni_esslen);
  347                 printf("%s\n", fail & 0x10 ? "!" : "");
  348         }
  349 #endif
  350         return fail;
  351 }
  352 
  353 /*
  354  * Complete a scan of potential channels.
  355  */
  356 void
  357 ieee80211_end_scan(struct ieee80211com *ic)
  358 {
  359         struct ieee80211_node *ni, *nextbs, *selbs;
  360         int i, fail;
  361 
  362         IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN, ("end %s scan\n",
  363                 (ic->ic_flags & IEEE80211_F_ASCAN) ?  "active" : "passive"));
  364 
  365         ic->ic_flags &= ~IEEE80211_F_ASCAN;
  366         ni = TAILQ_FIRST(&ic->ic_node);
  367 
  368         if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
  369                 /* XXX off stack? */
  370                 u_char occupied[roundup(IEEE80211_CHAN_MAX, NBBY)];
  371                 /*
  372                  * The passive scan to look for existing AP's completed,
  373                  * select a channel to camp on.  Identify the channels
  374                  * that already have one or more AP's and try to locate
  375                  * an unnoccupied one.  If that fails, pick a random
  376                  * channel from the active set.
  377                  */
  378                 for (; ni != NULL; ni = nextbs) {
  379                         nextbs = TAILQ_NEXT(ni, ni_list);
  380                         setbit(occupied, ieee80211_chan2ieee(ic, ni->ni_chan));
  381                 }
  382                 for (i = 0; i < IEEE80211_CHAN_MAX; i++)
  383                         if (isset(ic->ic_chan_active, i) && isclr(occupied, i))
  384                                 break;
  385                 if (i == IEEE80211_CHAN_MAX) {
  386                         fail = arc4random() & 3;        /* random 0-3 */
  387                         for (i = 0; i < IEEE80211_CHAN_MAX; i++)
  388                                 if (isset(ic->ic_chan_active, i) && fail-- == 0)
  389                                         break;
  390                 }
  391                 ieee80211_create_ibss(ic, &ic->ic_channels[i]);
  392                 return;
  393         }
  394         if (ni == NULL) {
  395                 IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN,
  396                         ("%s: no scan candidate\n", __func__));
  397   notfound:
  398                 if (ic->ic_opmode == IEEE80211_M_IBSS &&
  399                     (ic->ic_flags & IEEE80211_F_IBSSON) &&
  400                     ic->ic_des_esslen != 0) {
  401                         ieee80211_create_ibss(ic, ic->ic_ibss_chan);
  402                         return;
  403                 }
  404                 /*
  405                  * Reset the list of channels to scan and start again.
  406                  */
  407                 ieee80211_reset_scan(ic);
  408                 ieee80211_next_scan(ic);
  409                 return;
  410         }
  411         selbs = NULL;
  412         IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN,
  413                 ("\tmacaddr          bssid         chan  rssi rate flag  wep  essid\n"));
  414         for (; ni != NULL; ni = nextbs) {
  415                 nextbs = TAILQ_NEXT(ni, ni_list);
  416                 if (ni->ni_fails) {
  417                         /*
  418                          * The configuration of the access points may change
  419                          * during my scan.  So delete the entry for the AP
  420                          * and retry to associate if there is another beacon.
  421                          */
  422                         if (ni->ni_fails++ > 2)
  423                                 ieee80211_free_node(ic, ni);
  424                         continue;
  425                 }
  426                 if (ieee80211_match_bss(ic, ni) == 0) {
  427                         if (selbs == NULL)
  428                                 selbs = ni;
  429                         else if (ni->ni_rssi > selbs->ni_rssi)
  430                                 selbs = ni;
  431                 }
  432         }
  433         if (selbs == NULL)
  434                 goto notfound;
  435         (*ic->ic_node_copy)(ic, ic->ic_bss, selbs);
  436         ieee80211_node_newstate(ic->ic_bss, IEEE80211_STA_BSS);
  437         if (ic->ic_opmode == IEEE80211_M_IBSS) {
  438                 ieee80211_fix_rate(ic, ic->ic_bss, IEEE80211_F_DOFRATE |
  439                     IEEE80211_F_DONEGO | IEEE80211_F_DODEL);
  440                 if (ic->ic_bss->ni_rates.rs_nrates == 0)
  441                         goto notfound;
  442                 ieee80211_new_state(ic, IEEE80211_S_RUN, -1);
  443         } else {
  444                 ieee80211_new_state(ic, IEEE80211_S_AUTH, -1);
  445         }
  446 }
  447 
  448 int
  449 ieee80211_get_rate(struct ieee80211com *ic)
  450 {
  451         u_int8_t (*rates)[IEEE80211_RATE_MAXSIZE];
  452         int rate;
  453 
  454         rates = &ic->ic_bss->ni_rates.rs_rates;
  455 
  456         if (ic->ic_fixed_rate != -1)
  457                 rate = (*rates)[ic->ic_fixed_rate];
  458         else if (ic->ic_state == IEEE80211_S_RUN)
  459                 rate = (*rates)[ic->ic_bss->ni_txrate];
  460         else
  461                 rate = 0;
  462 
  463         return rate & IEEE80211_RATE_VAL;
  464 }
  465 
  466 static struct ieee80211_node *
  467 ieee80211_node_alloc(struct ieee80211com *ic)
  468 {
  469         struct ieee80211_node *ni;
  470         MALLOC(ni, struct ieee80211_node *, sizeof(struct ieee80211_node),
  471                 M_80211_NODE, M_NOWAIT | M_ZERO);
  472         return ni;
  473 }
  474 
  475 static void
  476 node_cleanup(struct ieee80211com *ic, struct ieee80211_node *ni)
  477 {
  478         if (ni->ni_challenge != NULL) {
  479                 FREE(ni->ni_challenge, M_DEVBUF);
  480                 ni->ni_challenge = NULL;
  481         }
  482 }
  483 
  484 static void
  485 ieee80211_node_free(struct ieee80211com *ic, struct ieee80211_node *ni)
  486 {
  487         node_cleanup(ic, ni);
  488         FREE(ni, M_80211_NODE);
  489 }
  490 
  491 static void
  492 ieee80211_node_copy(struct ieee80211com *ic,
  493         struct ieee80211_node *dst, const struct ieee80211_node *src)
  494 {
  495         node_cleanup(ic, dst);
  496         *dst = *src;
  497         dst->ni_challenge = NULL;
  498 }
  499 
  500 static u_int8_t
  501 ieee80211_node_getrssi(struct ieee80211com *ic, struct ieee80211_node *ni)
  502 {
  503         return ni->ni_rssi;
  504 }
  505 
  506 static void
  507 ieee80211_setup_node(struct ieee80211com *ic,
  508         struct ieee80211_node *ni, u_int8_t *macaddr)
  509 {
  510         int hash;
  511 
  512         IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
  513                 ("%s %s\n", __func__, ether_sprintf(macaddr)));
  514         IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr);
  515         hash = IEEE80211_NODE_HASH(macaddr);
  516         ieee80211_node_newstate(ni, IEEE80211_STA_CACHE);
  517 
  518         IEEE80211_NODE_LOCK_BH(ic);
  519         /*
  520          * Note we don't enable the inactive timer when acting
  521          * as a station.  Nodes created in this mode represent
  522          * AP's identified while scanning.  If we time them out
  523          * then several things happen: we can't return the data
  524          * to users to show the list of AP's we encountered, and
  525          * more importantly, we'll incorrectly deauthenticate
  526          * ourself because the inactivity timer will kick us off.
  527          */
  528         if (ic->ic_opmode != IEEE80211_M_STA &&
  529             TAILQ_EMPTY(&ic->ic_node))
  530                 ic->ic_inact_timer = IEEE80211_INACT_WAIT;
  531         TAILQ_INSERT_TAIL(&ic->ic_node, ni, ni_list);
  532         LIST_INSERT_HEAD(&ic->ic_hash[hash], ni, ni_hash);
  533         IEEE80211_NODE_UNLOCK_BH(ic);
  534 }
  535 
  536 struct ieee80211_node *
  537 ieee80211_alloc_node(struct ieee80211com *ic, u_int8_t *macaddr)
  538 {
  539         struct ieee80211_node *ni = ieee80211_alloc_node_helper(ic);
  540         if (ni != NULL) {
  541                 ieee80211_setup_node(ic, ni, macaddr);
  542         } else
  543                 ic->ic_stats.is_rx_nodealloc++;
  544         return ni;
  545 }
  546 
  547 struct ieee80211_node *
  548 ieee80211_dup_bss(struct ieee80211com *ic, u_int8_t *macaddr)
  549 {
  550         struct ieee80211_node *ni = ieee80211_alloc_node_helper(ic);
  551         if (ni != NULL) {
  552                 ieee80211_setup_node(ic, ni, macaddr);
  553                 /*
  554                  * Inherit from ic_bss.
  555                  */
  556                 IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_bss->ni_bssid);
  557                 ni->ni_chan = ic->ic_bss->ni_chan;
  558         } else
  559                 ic->ic_stats.is_rx_nodealloc++;
  560         return ni;
  561 }
  562 
  563 static struct ieee80211_node *
  564 _ieee80211_find_node(struct ieee80211com *ic, u_int8_t *macaddr)
  565 {
  566         struct ieee80211_node *ni;
  567         int hash;
  568 
  569         IEEE80211_NODE_LOCK_ASSERT(ic);
  570 
  571         hash = IEEE80211_NODE_HASH(macaddr);
  572         LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) {
  573                 if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr)) {
  574                         /* least-recently used is at tail */
  575                         TAILQ_REMOVE(&ic->ic_node, ni, ni_list);
  576                         TAILQ_INSERT_TAIL(&ic->ic_node, ni, ni_list);
  577                         return ni;
  578                 }
  579         }
  580         return NULL;
  581 }
  582 
  583 struct ieee80211_node *
  584 ieee80211_find_node(struct ieee80211com *ic, u_int8_t *macaddr)
  585 {
  586         struct ieee80211_node *ni;
  587 
  588         IEEE80211_NODE_LOCK(ic);
  589         ni = _ieee80211_find_node(ic, macaddr);
  590         IEEE80211_NODE_UNLOCK(ic);
  591         return ni;
  592 }
  593 
  594 /*
  595  * Return a reference to the appropriate node for sending
  596  * a data frame.  This handles node discovery in adhoc networks.
  597  *
  598  * Drivers will call this, so increase the reference count before
  599  * returning the node.
  600  */
  601 struct ieee80211_node *
  602 ieee80211_find_txnode(struct ieee80211com *ic, u_int8_t *macaddr)
  603 {
  604         struct ieee80211_node *ni;
  605 
  606         /*
  607          * The destination address should be in the node table
  608          * unless we are operating in station mode or this is a
  609          * multicast/broadcast frame.
  610          */
  611         if (ic->ic_opmode == IEEE80211_M_STA || IEEE80211_IS_MULTICAST(macaddr))
  612                 return ieee80211_ref_node(ic->ic_bss);
  613 
  614         /* XXX can't hold lock across dup_bss 'cuz of recursive locking */
  615         IEEE80211_NODE_LOCK(ic);
  616         ni = _ieee80211_find_node(ic, macaddr);
  617         IEEE80211_NODE_UNLOCK(ic);
  618         if (ni == NULL) {
  619                 if (ic->ic_opmode != IEEE80211_M_IBSS &&
  620                     ic->ic_opmode != IEEE80211_M_AHDEMO)
  621                         return NULL;
  622                 /*
  623                  * Fake up a node; this handles node discovery in
  624                  * adhoc mode.  Note that for the driver's benefit
  625                  * we we treat this like an association so the driver
  626                  * has an opportunity to setup it's private state.
  627                  *
  628                  * XXX need better way to handle this; issue probe
  629                  *     request so we can deduce rate set, etc.
  630                  */
  631                 if ((ni = ieee80211_dup_bss(ic, macaddr)) == NULL)
  632                         return NULL;
  633                 /* XXX no rate negotiation; just dup */
  634                 ni->ni_rates = ic->ic_bss->ni_rates;
  635                 if (ic->ic_newassoc)
  636                         (*ic->ic_newassoc)(ic, ni, 1);
  637         }
  638         return ieee80211_ref_node(ni);
  639 }
  640 
  641 /*
  642  * It is usually desirable to process a Rx packet using its sender's
  643  * node-record instead of the BSS record.
  644  *
  645  *  - AP mode: keep a node-record for every authenticated/associated
  646  *    station *in the BSS*. For future use, we also track neighboring
  647  *    APs, since they might belong to the same ESS.  APs in the same
  648  *    ESS may bridge packets to each other, forming a Wireless
  649  *    Distribution System (WDS).
  650  *
  651  * - IBSS mode: keep a node-record for every station *in the BSS*.
  652  *   Also track neighboring stations by their beacons/probe responses.
  653  *
  654  * - monitor mode: keep a node-record for every sender, regardless
  655  *   of BSS.
  656  *
  657  * - STA mode: the only available node-record is the BSS record,
  658  *   ic->ic_bss.
  659  *
  660  * Of all the 802.11 Control packets, only the node-records for
  661  * RTS packets node-record can be looked up.
  662  *
  663  * Return non-zero if the packet's node-record is kept, zero
  664  * otherwise.
  665  */
  666 static __inline int
  667 ieee80211_needs_rxnode(struct ieee80211com *ic, struct ieee80211_frame *wh,
  668     u_int8_t **bssid)
  669 {
  670         struct ieee80211_node *bss = ic->ic_bss;
  671         int monitor, rc = 0;
  672 
  673         monitor = (ic->ic_opmode == IEEE80211_M_MONITOR);
  674 
  675         *bssid = NULL;
  676 
  677         switch (wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) {
  678         case IEEE80211_FC0_TYPE_CTL:
  679                 if (!monitor)
  680                         break;
  681                 return (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) ==
  682                     IEEE80211_FC0_SUBTYPE_RTS;
  683         case IEEE80211_FC0_TYPE_MGT:
  684                 *bssid = wh->i_addr3;
  685                 switch (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) {
  686                 case IEEE80211_FC0_SUBTYPE_BEACON:
  687                 case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
  688                         rc = 1;
  689                         break;
  690                 default:
  691                         if (ic->ic_opmode == IEEE80211_M_STA)
  692                                 break;
  693                         rc = IEEE80211_ADDR_EQ(*bssid, bss->ni_bssid) ||
  694                              IEEE80211_ADDR_EQ(*bssid, etherbroadcastaddr);
  695                         break;
  696                 }
  697                 break;
  698         case IEEE80211_FC0_TYPE_DATA:
  699                 switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) {
  700                 case IEEE80211_FC1_DIR_NODS:
  701                         *bssid = wh->i_addr3;
  702                         if (ic->ic_opmode == IEEE80211_M_IBSS ||
  703                             ic->ic_opmode == IEEE80211_M_AHDEMO)
  704                                 rc = IEEE80211_ADDR_EQ(*bssid, bss->ni_bssid);
  705                         break;
  706                 case IEEE80211_FC1_DIR_TODS:
  707                         *bssid = wh->i_addr1;
  708                         if (ic->ic_opmode == IEEE80211_M_HOSTAP)
  709                                 rc = IEEE80211_ADDR_EQ(*bssid, bss->ni_bssid);
  710                         break;
  711                 case IEEE80211_FC1_DIR_FROMDS:
  712                 case IEEE80211_FC1_DIR_DSTODS:
  713                         *bssid = wh->i_addr2;
  714                         rc = (ic->ic_opmode == IEEE80211_M_HOSTAP);
  715                         break;
  716                 }
  717                 break;
  718         }
  719         return monitor || rc;
  720 }
  721 
  722 /* Drivers call this, so increase the reference count before returning
  723  * the node.
  724  */
  725 struct ieee80211_node *
  726 ieee80211_find_rxnode(struct ieee80211com *ic, struct ieee80211_frame *wh)
  727 {
  728         struct ieee80211_node *ni;
  729         const static u_int8_t zero[IEEE80211_ADDR_LEN];
  730         u_int8_t *bssid;
  731 
  732         if (!ieee80211_needs_rxnode(ic, wh, &bssid))
  733                 return ieee80211_ref_node(ic->ic_bss);
  734 
  735         IEEE80211_NODE_LOCK(ic);
  736         ni = _ieee80211_find_node(ic, wh->i_addr2);
  737         IEEE80211_NODE_UNLOCK(ic);
  738 
  739         if (ni != NULL)
  740                 return ieee80211_ref_node(ni);
  741 
  742         if (ic->ic_opmode == IEEE80211_M_HOSTAP)
  743                 return ieee80211_ref_node(ic->ic_bss);
  744 
  745         /* XXX see remarks in ieee80211_find_txnode */
  746         /* XXX no rate negotiation; just dup */
  747         if ((ni = ieee80211_dup_bss(ic, wh->i_addr2)) == NULL)
  748                 return ieee80211_ref_node(ic->ic_bss);
  749 
  750         IEEE80211_ADDR_COPY(ni->ni_bssid, (bssid != NULL) ? bssid : zero);
  751 
  752         ni->ni_rates = ic->ic_bss->ni_rates;
  753         if (ic->ic_newassoc)
  754                 (*ic->ic_newassoc)(ic, ni, 1);
  755 
  756         IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
  757                 ("%s: faked-up node %p for %s\n", __func__, ni,
  758                 ether_sprintf(wh->i_addr2)));
  759 
  760         return ieee80211_ref_node(ni);
  761 }
  762 
  763 /*
  764  * Like find but search based on the channel too.
  765  *
  766  * Note that ieee80211_find_node_for_beacon does not increase the
  767  * reference count before returning the node, because drivers are not
  768  * expected to call it.
  769  */
  770 struct ieee80211_node *
  771 ieee80211_find_node_for_beacon(struct ieee80211com *ic, u_int8_t *macaddr,
  772         struct ieee80211_channel *chan, char *ssid)
  773 {
  774         struct ieee80211_node *ni, *best;
  775         int hash;
  776         int best_score, score;
  777 
  778         best = NULL;
  779         best_score = -1;
  780 
  781         hash = IEEE80211_NODE_HASH(macaddr);
  782         IEEE80211_NODE_LOCK(ic);
  783         LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) {
  784                 if (!IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr))
  785                         continue;
  786 
  787                 score = (ni->ni_chan == chan) ? 1 : 0;
  788 
  789                 if (ssid[1] == 0 || ni->ni_esslen == 0)
  790                         score++;
  791                 else if (ssid[1] != ni->ni_esslen ||
  792                      memcmp(ssid + 2, ni->ni_essid, ssid[1]) != 0)
  793                         continue;
  794 
  795                 if (score > best_score) {
  796                         best = ni;
  797                         best_score = score;
  798                 }
  799         }
  800         IEEE80211_NODE_UNLOCK(ic);
  801         return best;
  802 }
  803 
  804 static void
  805 ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni)
  806 {
  807         IASSERT(ni != ic->ic_bss, ("freeing bss node"));
  808 
  809         IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
  810                 ("%s %s\n", __func__, ether_sprintf(ni->ni_macaddr)));
  811         IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap);
  812         TAILQ_REMOVE(&ic->ic_node, ni, ni_list);
  813         LIST_REMOVE(ni, ni_hash);
  814         ic->ic_nnodes--;
  815         if (!IF_IS_EMPTY(&ni->ni_savedq)) {
  816                 IF_PURGE(&ni->ni_savedq);
  817                 if (ic->ic_set_tim)
  818                         (*ic->ic_set_tim)(ic, ni->ni_associd, 0);
  819         }
  820         if (TAILQ_EMPTY(&ic->ic_node))
  821                 ic->ic_inact_timer = 0;
  822         (*ic->ic_node_free)(ic, ni);
  823         /* TBD indicate to drivers that a new node can be allocated */
  824 }
  825 
  826 void
  827 ieee80211_release_node(struct ieee80211com *ic, struct ieee80211_node *ni)
  828 {
  829         IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
  830                 ("%s %s refcnt %d\n", __func__,
  831                  ether_sprintf(ni->ni_macaddr), ni->ni_refcnt));
  832         if (ieee80211_node_decref(ni) == 0 &&
  833             ni->ni_state == IEEE80211_STA_COLLECT) {
  834                 IEEE80211_NODE_LOCK_BH(ic);
  835                 ieee80211_free_node(ic, ni);
  836                 IEEE80211_NODE_UNLOCK_BH(ic);
  837         }
  838 }
  839 
  840 void
  841 ieee80211_free_allnodes(struct ieee80211com *ic)
  842 {
  843         struct ieee80211_node *ni;
  844 
  845         IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE, ("free all nodes\n"));
  846         IEEE80211_NODE_LOCK_BH(ic);
  847         while ((ni = TAILQ_FIRST(&ic->ic_node)) != NULL)
  848                 ieee80211_free_node(ic, ni);
  849         IEEE80211_NODE_UNLOCK_BH(ic);
  850 
  851         if (ic->ic_bss != NULL)
  852                 node_cleanup(ic, ic->ic_bss);   /* for station mode */
  853 }
  854 
  855 /*
  856  * Timeout inactive nodes.  Note that we cannot hold the node
  857  * lock while sending a frame as this would lead to a LOR.
  858  * Instead we use a generation number to mark nodes that we've
  859  * scanned and drop the lock and restart a scan if we have to
  860  * time out a node.  Since we are single-threaded by virtue of
  861  * controlling the inactivity timer we can be sure this will
  862  * process each node only once.
  863  */
  864 void
  865 ieee80211_clean_nodes(struct ieee80211com *ic)
  866 {
  867         struct ieee80211_node *ni;
  868         u_int gen = ic->ic_scangen++;           /* NB: ok 'cuz single-threaded*/
  869 
  870 restart:
  871         IEEE80211_NODE_LOCK(ic);
  872         TAILQ_FOREACH(ni, &ic->ic_node, ni_list) {
  873                 if (ic->ic_nnodes <= ic->ic_max_nnodes)
  874                         break;
  875                 if (ni->ni_scangen == gen)      /* previously handled */
  876                         continue;
  877                 ni->ni_scangen = gen;
  878                 if (ni->ni_refcnt > 0)
  879                         continue;
  880                 IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
  881                     ("station %s purged from LRU cache\n",
  882                     ether_sprintf(ni->ni_macaddr)));
  883                 /*
  884                  * Send a deauthenticate frame.
  885                  *
  886                  * Drop the node lock before sending the
  887                  * deauthentication frame in case the driver takes
  888                  * a lock, as this will result in a LOR between the
  889                  * node lock and the driver lock.
  890                  */
  891                 IEEE80211_NODE_UNLOCK(ic);
  892                 if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
  893                         IEEE80211_SEND_MGMT(ic, ni,
  894                             IEEE80211_FC0_SUBTYPE_DEAUTH,
  895                             IEEE80211_REASON_AUTH_EXPIRE);
  896                         ieee80211_node_leave(ic, ni);
  897                 } else
  898                         ieee80211_free_node(ic, ni);
  899                 ic->ic_stats.is_node_timeout++;
  900                 goto restart;
  901         }
  902         IEEE80211_NODE_UNLOCK(ic);
  903 }
  904 
  905 void
  906 ieee80211_iterate_nodes(struct ieee80211com *ic, ieee80211_iter_func *f, void *arg)
  907 {
  908         struct ieee80211_node *ni;
  909 
  910         IEEE80211_NODE_LOCK(ic);
  911         TAILQ_FOREACH(ni, &ic->ic_node, ni_list)
  912                 (*f)(arg, ni);
  913         IEEE80211_NODE_UNLOCK(ic);
  914 }
  915 
  916 void
  917 ieee80211_node_join(struct ieee80211com *ic, struct ieee80211_node *ni, int resp)
  918 {
  919         int newassoc;
  920 
  921         if (ni->ni_associd == 0) {
  922                 u_int16_t aid;
  923 
  924                 /*
  925                  * It would be clever to search the bitmap
  926                  * more efficiently, but this will do for now.
  927                  */
  928                 for (aid = 1; aid < ic->ic_max_aid; aid++) {
  929                         if (!IEEE80211_AID_ISSET(aid,
  930                             ic->ic_aid_bitmap))
  931                                 break;
  932                 }
  933                 if (aid >= ic->ic_max_aid) {
  934                         IEEE80211_SEND_MGMT(ic, ni, resp,
  935                             IEEE80211_REASON_ASSOC_TOOMANY);
  936                         ieee80211_node_leave(ic, ni);
  937                         return;
  938                 }
  939                 ni->ni_associd = aid | 0xc000;
  940                 IEEE80211_AID_SET(ni->ni_associd, ic->ic_aid_bitmap);
  941                 newassoc = 1;
  942                 /* XXX for 11g must turn off short slot time if long
  943                    slot time sta associates */
  944         } else
  945                 newassoc = 0;
  946 
  947         IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC | IEEE80211_MSG_DEBUG,
  948                 ("station %s %s associated at aid %d\n",
  949                 ether_sprintf(ni->ni_macaddr),
  950                 (newassoc ? "newly" : "already"),
  951                 ni->ni_associd & ~0xc000));
  952 
  953         /* give driver a chance to setup state like ni_txrate */
  954         if (ic->ic_newassoc)
  955                 (*ic->ic_newassoc)(ic, ni, newassoc);
  956         IEEE80211_SEND_MGMT(ic, ni, resp, IEEE80211_STATUS_SUCCESS);
  957         ieee80211_node_newstate(ni, IEEE80211_STA_ASSOC);
  958 }
  959 
  960 /*
  961  * Handle bookkeeping for station deauthentication/disassociation
  962  * when operating as an ap.
  963  */
  964 void
  965 ieee80211_node_leave(struct ieee80211com *ic, struct ieee80211_node *ni)
  966 {
  967 
  968         IASSERT(ic->ic_opmode == IEEE80211_M_HOSTAP,
  969                 ("not in ap mode, mode %u", ic->ic_opmode));
  970         /*
  971          * If node wasn't previously associated all
  972          * we need to do is reclaim the reference.
  973          */
  974         if (ni->ni_associd == 0)
  975                 return;
  976         IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap);
  977         ni->ni_associd = 0;
  978         ieee80211_node_newstate(ni, IEEE80211_STA_COLLECT);
  979 }

Cache object: 29b3857958366eb618616a07d0c34c5b


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


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