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_power.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 /*-
    2  * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  *
   14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   24  */
   25 
   26 #include <sys/cdefs.h>
   27 __FBSDID("$FreeBSD: releng/9.1/sys/net80211/ieee80211_power.c 223842 2011-07-07 15:41:40Z kevlo $");
   28 
   29 /*
   30  * IEEE 802.11 power save support.
   31  */
   32 #include "opt_wlan.h"
   33 
   34 #include <sys/param.h>
   35 #include <sys/systm.h> 
   36 #include <sys/kernel.h>
   37  
   38 #include <sys/socket.h>
   39 
   40 #include <net/if.h>
   41 #include <net/if_media.h>
   42 #include <net/ethernet.h>
   43 
   44 #include <net80211/ieee80211_var.h>
   45 
   46 #include <net/bpf.h>
   47 
   48 static void ieee80211_update_ps(struct ieee80211vap *, int);
   49 static int ieee80211_set_tim(struct ieee80211_node *, int);
   50 
   51 MALLOC_DEFINE(M_80211_POWER, "80211power", "802.11 power save state");
   52 
   53 void
   54 ieee80211_power_attach(struct ieee80211com *ic)
   55 {
   56 }
   57 
   58 void
   59 ieee80211_power_detach(struct ieee80211com *ic)
   60 {
   61 }
   62 
   63 void
   64 ieee80211_power_vattach(struct ieee80211vap *vap)
   65 {
   66         if (vap->iv_opmode == IEEE80211_M_HOSTAP ||
   67             vap->iv_opmode == IEEE80211_M_IBSS) {
   68                 /* NB: driver should override */
   69                 vap->iv_update_ps = ieee80211_update_ps;
   70                 vap->iv_set_tim = ieee80211_set_tim;
   71         }
   72 }
   73 
   74 void
   75 ieee80211_power_latevattach(struct ieee80211vap *vap)
   76 {
   77         /*
   78          * Allocate these only if needed.  Beware that we
   79          * know adhoc mode doesn't support ATIM yet...
   80          */
   81         if (vap->iv_opmode == IEEE80211_M_HOSTAP) {
   82                 vap->iv_tim_len = howmany(vap->iv_max_aid,8) * sizeof(uint8_t);
   83                 vap->iv_tim_bitmap = (uint8_t *) malloc(vap->iv_tim_len,
   84                         M_80211_POWER, M_NOWAIT | M_ZERO);
   85                 if (vap->iv_tim_bitmap == NULL) {
   86                         printf("%s: no memory for TIM bitmap!\n", __func__);
   87                         /* XXX good enough to keep from crashing? */
   88                         vap->iv_tim_len = 0;
   89                 }
   90         }
   91 }
   92 
   93 void
   94 ieee80211_power_vdetach(struct ieee80211vap *vap)
   95 {
   96         if (vap->iv_tim_bitmap != NULL) {
   97                 free(vap->iv_tim_bitmap, M_80211_POWER);
   98                 vap->iv_tim_bitmap = NULL;
   99         }
  100 }
  101 
  102 void
  103 ieee80211_psq_init(struct ieee80211_psq *psq, const char *name)
  104 {
  105         memset(psq, 0, sizeof(*psq));
  106         psq->psq_maxlen = IEEE80211_PS_MAX_QUEUE;
  107         IEEE80211_PSQ_INIT(psq, name);          /* OS-dependent setup */
  108 }
  109 
  110 void
  111 ieee80211_psq_cleanup(struct ieee80211_psq *psq)
  112 {
  113 #if 0
  114         psq_drain(psq);                         /* XXX should not be needed? */
  115 #else
  116         KASSERT(psq->psq_len == 0, ("%d frames on ps q", psq->psq_len));
  117 #endif
  118         IEEE80211_PSQ_DESTROY(psq);             /* OS-dependent cleanup */
  119 }
  120 
  121 /*
  122  * Return the highest priority frame in the ps queue.
  123  */
  124 struct mbuf *
  125 ieee80211_node_psq_dequeue(struct ieee80211_node *ni, int *qlen)
  126 {
  127         struct ieee80211_psq *psq = &ni->ni_psq;
  128         struct ieee80211_psq_head *qhead;
  129         struct mbuf *m;
  130 
  131         IEEE80211_PSQ_LOCK(psq);
  132         qhead = &psq->psq_head[0];
  133 again:
  134         if ((m = qhead->head) != NULL) {
  135                 if ((qhead->head = m->m_nextpkt) == NULL)
  136                         qhead->tail = NULL;
  137                 KASSERT(qhead->len > 0, ("qhead len %d", qhead->len));
  138                 qhead->len--;
  139                 KASSERT(psq->psq_len > 0, ("psq len %d", psq->psq_len));
  140                 psq->psq_len--;
  141                 m->m_nextpkt = NULL;
  142         }
  143         if (m == NULL && qhead == &psq->psq_head[0]) {
  144                 /* Algol-68 style for loop */
  145                 qhead = &psq->psq_head[1];
  146                 goto again;
  147         }
  148         if (qlen != NULL)
  149                 *qlen = psq->psq_len;
  150         IEEE80211_PSQ_UNLOCK(psq);
  151         return m;
  152 }
  153 
  154 /*
  155  * Reclaim an mbuf from the ps q.  If marked with M_ENCAP
  156  * we assume there is a node reference that must be relcaimed.
  157  */
  158 static void
  159 psq_mfree(struct mbuf *m)
  160 {
  161         if (m->m_flags & M_ENCAP) {
  162                 struct ieee80211_node *ni = (void *) m->m_pkthdr.rcvif;
  163                 ieee80211_free_node(ni);
  164         }
  165         m->m_nextpkt = NULL;
  166         m_freem(m);
  167 }
  168 
  169 /*
  170  * Clear any frames queued in the power save queue.
  171  * The number of frames that were present is returned.
  172  */
  173 static int
  174 psq_drain(struct ieee80211_psq *psq)
  175 {
  176         struct ieee80211_psq_head *qhead;
  177         struct mbuf *m;
  178         int qlen;
  179 
  180         IEEE80211_PSQ_LOCK(psq);
  181         qlen = psq->psq_len;
  182         qhead = &psq->psq_head[0];
  183 again:
  184         while ((m = qhead->head) != NULL) {
  185                 qhead->head = m->m_nextpkt;
  186                 psq_mfree(m);
  187         }
  188         qhead->tail = NULL;
  189         qhead->len = 0;
  190         if (qhead == &psq->psq_head[0]) {       /* Algol-68 style for loop */
  191                 qhead = &psq->psq_head[1];
  192                 goto again;
  193         }
  194         psq->psq_len = 0;
  195         IEEE80211_PSQ_UNLOCK(psq);
  196 
  197         return qlen;
  198 }
  199 
  200 /*
  201  * Clear any frames queued in the power save queue.
  202  * The number of frames that were present is returned.
  203  */
  204 int
  205 ieee80211_node_psq_drain(struct ieee80211_node *ni)
  206 {
  207         return psq_drain(&ni->ni_psq);
  208 }
  209 
  210 /*
  211  * Age frames on the power save queue. The aging interval is
  212  * 4 times the listen interval specified by the station.  This
  213  * number is factored into the age calculations when the frame
  214  * is placed on the queue.  We store ages as time differences
  215  * so we can check and/or adjust only the head of the list.
  216  * If a frame's age exceeds the threshold then discard it.
  217  * The number of frames discarded is returned so the caller
  218  * can check if it needs to adjust the tim.
  219  */
  220 int
  221 ieee80211_node_psq_age(struct ieee80211_node *ni)
  222 {
  223         struct ieee80211_psq *psq = &ni->ni_psq;
  224         int discard = 0;
  225 
  226         if (psq->psq_len != 0) {
  227 #ifdef IEEE80211_DEBUG
  228                 struct ieee80211vap *vap = ni->ni_vap;
  229 #endif
  230                 struct ieee80211_psq_head *qhead;
  231                 struct mbuf *m;
  232 
  233                 IEEE80211_PSQ_LOCK(psq);
  234                 qhead = &psq->psq_head[0];
  235         again:
  236                 while ((m = qhead->head) != NULL &&
  237                     M_AGE_GET(m) < IEEE80211_INACT_WAIT) {
  238                         IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
  239                              "discard frame, age %u", M_AGE_GET(m));
  240                         if ((qhead->head = m->m_nextpkt) == NULL)
  241                                 qhead->tail = NULL;
  242                         KASSERT(qhead->len > 0, ("qhead len %d", qhead->len));
  243                         qhead->len--;
  244                         KASSERT(psq->psq_len > 0, ("psq len %d", psq->psq_len));
  245                         psq->psq_len--;
  246                         psq_mfree(m);
  247                         discard++;
  248                 }
  249                 if (qhead == &psq->psq_head[0]) { /* Algol-68 style for loop */
  250                         qhead = &psq->psq_head[1];
  251                         goto again;
  252                 }
  253                 if (m != NULL)
  254                         M_AGE_SUB(m, IEEE80211_INACT_WAIT);
  255                 IEEE80211_PSQ_UNLOCK(psq);
  256 
  257                 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
  258                     "discard %u frames for age", discard);
  259                 IEEE80211_NODE_STAT_ADD(ni, ps_discard, discard);
  260         }
  261         return discard;
  262 }
  263 
  264 /*
  265  * Handle a change in the PS station occupancy.
  266  */
  267 static void
  268 ieee80211_update_ps(struct ieee80211vap *vap, int nsta)
  269 {
  270 
  271         KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP ||
  272                 vap->iv_opmode == IEEE80211_M_IBSS,
  273                 ("operating mode %u", vap->iv_opmode));
  274 }
  275 
  276 /*
  277  * Indicate whether there are frames queued for a station in power-save mode.
  278  */
  279 static int
  280 ieee80211_set_tim(struct ieee80211_node *ni, int set)
  281 {
  282         struct ieee80211vap *vap = ni->ni_vap;
  283         struct ieee80211com *ic = ni->ni_ic;
  284         uint16_t aid;
  285         int changed;
  286 
  287         KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP ||
  288                 vap->iv_opmode == IEEE80211_M_IBSS,
  289                 ("operating mode %u", vap->iv_opmode));
  290 
  291         aid = IEEE80211_AID(ni->ni_associd);
  292         KASSERT(aid < vap->iv_max_aid,
  293                 ("bogus aid %u, max %u", aid, vap->iv_max_aid));
  294 
  295         IEEE80211_LOCK(ic);
  296         changed = (set != (isset(vap->iv_tim_bitmap, aid) != 0));
  297         if (changed) {
  298                 if (set) {
  299                         setbit(vap->iv_tim_bitmap, aid);
  300                         vap->iv_ps_pending++;
  301                 } else {
  302                         clrbit(vap->iv_tim_bitmap, aid);
  303                         vap->iv_ps_pending--;
  304                 }
  305                 /* NB: we know vap is in RUN state so no need to check */
  306                 vap->iv_update_beacon(vap, IEEE80211_BEACON_TIM);
  307         }
  308         IEEE80211_UNLOCK(ic);
  309 
  310         return changed;
  311 }
  312 
  313 /*
  314  * Save an outbound packet for a node in power-save sleep state.
  315  * The new packet is placed on the node's saved queue, and the TIM
  316  * is changed, if necessary.
  317  */
  318 int
  319 ieee80211_pwrsave(struct ieee80211_node *ni, struct mbuf *m)
  320 {
  321         struct ieee80211_psq *psq = &ni->ni_psq;
  322         struct ieee80211vap *vap = ni->ni_vap;
  323         struct ieee80211com *ic = ni->ni_ic;
  324         struct ieee80211_psq_head *qhead;
  325         int qlen, age;
  326 
  327         IEEE80211_PSQ_LOCK(psq);
  328         if (psq->psq_len >= psq->psq_maxlen) {
  329                 psq->psq_drops++;
  330                 IEEE80211_PSQ_UNLOCK(psq);
  331                 IEEE80211_NOTE(vap, IEEE80211_MSG_ANY, ni,
  332                     "pwr save q overflow, drops %d (size %d)",
  333                     psq->psq_drops, psq->psq_len);
  334 #ifdef IEEE80211_DEBUG
  335                 if (ieee80211_msg_dumppkts(vap))
  336                         ieee80211_dump_pkt(ni->ni_ic, mtod(m, caddr_t),
  337                             m->m_len, -1, -1);
  338 #endif
  339                 psq_mfree(m);
  340                 return ENOSPC;
  341         }
  342         /*
  343          * Tag the frame with it's expiry time and insert it in
  344          * the appropriate queue.  The aging interval is 4 times
  345          * the listen interval specified by the station. Frames
  346          * that sit around too long are reclaimed using this
  347          * information.
  348          */
  349         /* TU -> secs.  XXX handle overflow? */
  350         age = IEEE80211_TU_TO_MS((ni->ni_intval * ic->ic_bintval) << 2) / 1000;
  351         /*
  352          * Encapsulated frames go on the high priority queue,
  353          * other stuff goes on the low priority queue.  We use
  354          * this to order frames returned out of the driver
  355          * ahead of frames we collect in ieee80211_start.
  356          */
  357         if (m->m_flags & M_ENCAP)
  358                 qhead = &psq->psq_head[0];
  359         else
  360                 qhead = &psq->psq_head[1];
  361         if (qhead->tail == NULL) {
  362                 struct mbuf *mh;
  363 
  364                 qhead->head = m;
  365                 /*
  366                  * Take care to adjust age when inserting the first
  367                  * frame of a queue and the other queue already has
  368                  * frames.  We need to preserve the age difference
  369                  * relationship so ieee80211_node_psq_age works.
  370                  */
  371                 if (qhead == &psq->psq_head[1]) {
  372                         mh = psq->psq_head[0].head;
  373                         if (mh != NULL)
  374                                 age-= M_AGE_GET(mh);
  375                 } else {
  376                         mh = psq->psq_head[1].head;
  377                         if (mh != NULL) {
  378                                 int nage = M_AGE_GET(mh) - age;
  379                                 /* XXX is clamping to zero good 'nuf? */
  380                                 M_AGE_SET(mh, nage < 0 ? 0 : nage);
  381                         }
  382                 }
  383         } else {
  384                 qhead->tail->m_nextpkt = m;
  385                 age -= M_AGE_GET(qhead->head);
  386         }
  387         KASSERT(age >= 0, ("age %d", age));
  388         M_AGE_SET(m, age);
  389         m->m_nextpkt = NULL;
  390         qhead->tail = m;
  391         qhead->len++;
  392         qlen = ++(psq->psq_len);
  393         IEEE80211_PSQ_UNLOCK(psq);
  394 
  395         IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
  396             "save frame with age %d, %u now queued", age, qlen);
  397 
  398         if (qlen == 1 && vap->iv_set_tim != NULL)
  399                 vap->iv_set_tim(ni, 1);
  400 
  401         return 0;
  402 }
  403 
  404 /*
  405  * Move frames from the ps q to the vap's send queue
  406  * and/or the driver's send queue; and kick the start
  407  * method for each, as appropriate.  Note we're careful
  408  * to preserve packet ordering here.
  409  */
  410 static void
  411 pwrsave_flushq(struct ieee80211_node *ni)
  412 {
  413         struct ieee80211_psq *psq = &ni->ni_psq;
  414         struct ieee80211vap *vap = ni->ni_vap;
  415         struct ieee80211_psq_head *qhead;
  416         struct ifnet *parent, *ifp;
  417 
  418         IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
  419             "flush ps queue, %u packets queued", psq->psq_len);
  420 
  421         IEEE80211_PSQ_LOCK(psq);
  422         qhead = &psq->psq_head[0];      /* 802.11 frames */
  423         if (qhead->head != NULL) {
  424                 /* XXX could dispatch through vap and check M_ENCAP */
  425                 parent = vap->iv_ic->ic_ifp;
  426                 /* XXX need different driver interface */
  427                 /* XXX bypasses q max and OACTIVE */
  428                 IF_PREPEND_LIST(&parent->if_snd, qhead->head, qhead->tail,
  429                     qhead->len);
  430                 qhead->head = qhead->tail = NULL;
  431                 qhead->len = 0;
  432         } else
  433                 parent = NULL;
  434 
  435         qhead = &psq->psq_head[1];      /* 802.3 frames */
  436         if (qhead->head != NULL) {
  437                 ifp = vap->iv_ifp;
  438                 /* XXX need different driver interface */
  439                 /* XXX bypasses q max and OACTIVE */
  440                 IF_PREPEND_LIST(&ifp->if_snd, qhead->head, qhead->tail,
  441                     qhead->len);
  442                 qhead->head = qhead->tail = NULL;
  443                 qhead->len = 0;
  444         } else
  445                 ifp = NULL;
  446         psq->psq_len = 0;
  447         IEEE80211_PSQ_UNLOCK(psq);
  448 
  449         /* NB: do this outside the psq lock */
  450         /* XXX packets might get reordered if parent is OACTIVE */
  451         if (parent != NULL)
  452                 if_start(parent);
  453         if (ifp != NULL)
  454                 if_start(ifp);
  455 }
  456 
  457 /*
  458  * Handle station power-save state change.
  459  */
  460 void
  461 ieee80211_node_pwrsave(struct ieee80211_node *ni, int enable)
  462 {
  463         struct ieee80211vap *vap = ni->ni_vap;
  464         int update;
  465 
  466         update = 0;
  467         if (enable) {
  468                 if ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
  469                         vap->iv_ps_sta++;
  470                         update = 1;
  471                 }
  472                 ni->ni_flags |= IEEE80211_NODE_PWR_MGT;
  473                 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
  474                     "power save mode on, %u sta's in ps mode", vap->iv_ps_sta);
  475 
  476                 if (update)
  477                         vap->iv_update_ps(vap, vap->iv_ps_sta);
  478         } else {
  479                 if (ni->ni_flags & IEEE80211_NODE_PWR_MGT) {
  480                         vap->iv_ps_sta--;
  481                         update = 1;
  482                 }
  483                 ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT;
  484                 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
  485                     "power save mode off, %u sta's in ps mode", vap->iv_ps_sta);
  486 
  487                 /* NB: order here is intentional so TIM is clear before flush */
  488                 if (vap->iv_set_tim != NULL)
  489                         vap->iv_set_tim(ni, 0);
  490                 if (update) {
  491                         /* NB if no sta's in ps, driver should flush mc q */
  492                         vap->iv_update_ps(vap, vap->iv_ps_sta);
  493                 }
  494                 if (ni->ni_psq.psq_len != 0)
  495                         pwrsave_flushq(ni);
  496         }
  497 }
  498 
  499 /*
  500  * Handle power-save state change in station mode.
  501  */
  502 void
  503 ieee80211_sta_pwrsave(struct ieee80211vap *vap, int enable)
  504 {
  505         struct ieee80211_node *ni = vap->iv_bss;
  506 
  507         if (!((enable != 0) ^ ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) != 0)))
  508                 return;
  509 
  510         IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
  511             "sta power save mode %s", enable ? "on" : "off");
  512         if (!enable) {
  513                 ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT;
  514                 ieee80211_send_nulldata(ieee80211_ref_node(ni));
  515                 /*
  516                  * Flush any queued frames; we can do this immediately
  517                  * because we know they'll be queued behind the null
  518                  * data frame we send the ap.
  519                  * XXX can we use a data frame to take us out of ps?
  520                  */
  521                 if (ni->ni_psq.psq_len != 0)
  522                         pwrsave_flushq(ni);
  523         } else {
  524                 ni->ni_flags |= IEEE80211_NODE_PWR_MGT;
  525                 ieee80211_send_nulldata(ieee80211_ref_node(ni));
  526         }
  527 }

Cache object: 645c3dcd38918237b11b8b4c7812c5fc


[ 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.