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 * $FreeBSD: head/sys/net80211/ieee80211_power.c 186302 2008-12-18 23:00:09Z sam $ 26 */ 27 28 /* 29 * IEEE 802.11 power save support. 30 */ 31 #include "opt_wlan.h" 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/kernel.h> 36 37 #include <sys/socket.h> 38 39 #include <net/if.h> 40 #include <net/if_media.h> 41 #include <net/ethernet.h> 42 #include <net/route.h> 43 44 #include <netproto/802_11/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 *) kmalloc(vap->iv_tim_len, 84 M_80211_POWER, M_INTWAIT | M_ZERO); 85 if (vap->iv_tim_bitmap == NULL) { 86 kprintf("%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 kfree(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 } 108 109 void 110 ieee80211_psq_cleanup(struct ieee80211_psq *psq) 111 { 112 #if 0 113 psq_drain(psq); /* XXX should not be needed? */ 114 #else 115 KASSERT(psq->psq_len == 0, ("%d frames on ps q", psq->psq_len)); 116 #endif 117 } 118 119 /* 120 * Return the highest priority frame in the ps queue. 121 */ 122 struct mbuf * 123 ieee80211_node_psq_dequeue(struct ieee80211_node *ni, int *qlen) 124 { 125 struct ieee80211_psq *psq = &ni->ni_psq; 126 struct ieee80211_psq_head *qhead; 127 struct mbuf *m; 128 129 qhead = &psq->psq_head[0]; 130 again: 131 if ((m = qhead->head) != NULL) { 132 if ((qhead->head = m->m_nextpkt) == NULL) 133 qhead->tail = NULL; 134 KASSERT(qhead->len > 0, ("qhead len %d", qhead->len)); 135 qhead->len--; 136 KASSERT(psq->psq_len > 0, ("psq len %d", psq->psq_len)); 137 psq->psq_len--; 138 m->m_nextpkt = NULL; 139 } 140 if (m == NULL && qhead == &psq->psq_head[0]) { 141 /* Algol-68 style for loop */ 142 qhead = &psq->psq_head[1]; 143 goto again; 144 } 145 if (qlen != NULL) 146 *qlen = psq->psq_len; 147 return m; 148 } 149 150 /* 151 * Reclaim an mbuf from the ps q. If marked with M_ENCAP 152 * we assume there is a node reference that must be relcaimed. 153 */ 154 static void 155 psq_mfree(struct mbuf *m) 156 { 157 if (m->m_flags & M_ENCAP) { 158 struct ieee80211_node *ni = (void *) m->m_pkthdr.rcvif; 159 ieee80211_free_node(ni); 160 } 161 m->m_nextpkt = NULL; 162 m_freem(m); 163 } 164 165 /* 166 * Clear any frames queued in the power save queue. 167 * The number of frames that were present is returned. 168 */ 169 static int 170 psq_drain(struct ieee80211_psq *psq) 171 { 172 struct ieee80211_psq_head *qhead; 173 struct mbuf *m; 174 int qlen; 175 176 qlen = psq->psq_len; 177 qhead = &psq->psq_head[0]; 178 again: 179 while ((m = qhead->head) != NULL) { 180 qhead->head = m->m_nextpkt; 181 psq_mfree(m); 182 } 183 qhead->tail = NULL; 184 qhead->len = 0; 185 if (qhead == &psq->psq_head[0]) { /* Algol-68 style for loop */ 186 qhead = &psq->psq_head[1]; 187 goto again; 188 } 189 psq->psq_len = 0; 190 191 return qlen; 192 } 193 194 /* 195 * Clear any frames queued in the power save queue. 196 * The number of frames that were present is returned. 197 */ 198 int 199 ieee80211_node_psq_drain(struct ieee80211_node *ni) 200 { 201 return psq_drain(&ni->ni_psq); 202 } 203 204 /* 205 * Age frames on the power save queue. The aging interval is 206 * 4 times the listen interval specified by the station. This 207 * number is factored into the age calculations when the frame 208 * is placed on the queue. We store ages as time differences 209 * so we can check and/or adjust only the head of the list. 210 * If a frame's age exceeds the threshold then discard it. 211 * The number of frames discarded is returned so the caller 212 * can check if it needs to adjust the tim. 213 */ 214 int 215 ieee80211_node_psq_age(struct ieee80211_node *ni) 216 { 217 struct ieee80211_psq *psq = &ni->ni_psq; 218 int discard = 0; 219 220 if (psq->psq_len != 0) { 221 #ifdef IEEE80211_DEBUG 222 struct ieee80211vap *vap = ni->ni_vap; 223 #endif 224 struct ieee80211_psq_head *qhead; 225 struct mbuf *m; 226 227 qhead = &psq->psq_head[0]; 228 again: 229 while ((m = qhead->head) != NULL && 230 M_AGE_GET(m) < IEEE80211_INACT_WAIT) { 231 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni, 232 "discard frame, age %u", M_AGE_GET(m)); 233 if ((qhead->head = m->m_nextpkt) == NULL) 234 qhead->tail = NULL; 235 KASSERT(qhead->len > 0, ("qhead len %d", qhead->len)); 236 qhead->len--; 237 KASSERT(psq->psq_len > 0, ("psq len %d", psq->psq_len)); 238 psq->psq_len--; 239 psq_mfree(m); 240 discard++; 241 } 242 if (qhead == &psq->psq_head[0]) { /* Algol-68 style for loop */ 243 qhead = &psq->psq_head[1]; 244 goto again; 245 } 246 if (m != NULL) 247 M_AGE_SUB(m, IEEE80211_INACT_WAIT); 248 249 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni, 250 "discard %u frames for age", discard); 251 IEEE80211_NODE_STAT_ADD(ni, ps_discard, discard); 252 } 253 return discard; 254 } 255 256 /* 257 * Handle a change in the PS station occupancy. 258 */ 259 static void 260 ieee80211_update_ps(struct ieee80211vap *vap, int nsta) 261 { 262 263 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP || 264 vap->iv_opmode == IEEE80211_M_IBSS, 265 ("operating mode %u", vap->iv_opmode)); 266 } 267 268 /* 269 * Indicate whether there are frames queued for a station in power-save mode. 270 */ 271 static int 272 ieee80211_set_tim(struct ieee80211_node *ni, int set) 273 { 274 struct ieee80211vap *vap = ni->ni_vap; 275 uint16_t aid; 276 int changed; 277 278 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP || 279 vap->iv_opmode == IEEE80211_M_IBSS, 280 ("operating mode %u", vap->iv_opmode)); 281 282 aid = IEEE80211_AID(ni->ni_associd); 283 KASSERT(aid < vap->iv_max_aid, 284 ("bogus aid %u, max %u", aid, vap->iv_max_aid)); 285 286 changed = (set != (isset(vap->iv_tim_bitmap, aid) != 0)); 287 if (changed) { 288 if (set) { 289 setbit(vap->iv_tim_bitmap, aid); 290 vap->iv_ps_pending++; 291 } else { 292 clrbit(vap->iv_tim_bitmap, aid); 293 vap->iv_ps_pending--; 294 } 295 /* NB: we know vap is in RUN state so no need to check */ 296 vap->iv_update_beacon(vap, IEEE80211_BEACON_TIM); 297 } 298 299 return changed; 300 } 301 302 /* 303 * Save an outbound packet for a node in power-save sleep state. 304 * The new packet is placed on the node's saved queue, and the TIM 305 * is changed, if necessary. 306 */ 307 int 308 ieee80211_pwrsave(struct ieee80211_node *ni, struct mbuf *m) 309 { 310 struct ieee80211_psq *psq = &ni->ni_psq; 311 struct ieee80211vap *vap = ni->ni_vap; 312 struct ieee80211com *ic = ni->ni_ic; 313 struct ieee80211_psq_head *qhead; 314 int qlen, age; 315 316 if (psq->psq_len >= psq->psq_maxlen) { 317 psq->psq_drops++; 318 IEEE80211_NOTE(vap, IEEE80211_MSG_ANY, ni, 319 "pwr save q overflow, drops %d (size %d)", 320 psq->psq_drops, psq->psq_len); 321 #ifdef IEEE80211_DEBUG 322 if (ieee80211_msg_dumppkts(vap)) 323 ieee80211_dump_pkt(ni->ni_ic, mtod(m, caddr_t), 324 m->m_len, -1, -1); 325 #endif 326 psq_mfree(m); 327 return ENOSPC; 328 } 329 /* 330 * Tag the frame with it's expiry time and insert it in 331 * the appropriate queue. The aging interval is 4 times 332 * the listen interval specified by the station. Frames 333 * that sit around too long are reclaimed using this 334 * information. 335 */ 336 /* TU -> secs. XXX handle overflow? */ 337 age = IEEE80211_TU_TO_MS((ni->ni_intval * ic->ic_bintval) << 2) / 1000; 338 /* 339 * Encapsulated frames go on the high priority queue, 340 * other stuff goes on the low priority queue. We use 341 * this to order frames returned out of the driver 342 * ahead of frames we collect in ieee80211_start. 343 */ 344 if (m->m_flags & M_ENCAP) 345 qhead = &psq->psq_head[0]; 346 else 347 qhead = &psq->psq_head[1]; 348 if (qhead->tail == NULL) { 349 struct mbuf *mh; 350 351 qhead->head = m; 352 /* 353 * Take care to adjust age when inserting the first 354 * frame of a queue and the other queue already has 355 * frames. We need to preserve the age difference 356 * relationship so ieee80211_node_psq_age works. 357 */ 358 if (qhead == &psq->psq_head[1]) { 359 mh = psq->psq_head[0].head; 360 if (mh != NULL) 361 age-= M_AGE_GET(mh); 362 } else { 363 mh = psq->psq_head[1].head; 364 if (mh != NULL) { 365 int nage = M_AGE_GET(mh) - age; 366 /* XXX is clamping to zero good 'nuf? */ 367 M_AGE_SET(mh, nage < 0 ? 0 : nage); 368 } 369 } 370 } else { 371 qhead->tail->m_nextpkt = m; 372 age -= M_AGE_GET(qhead->head); 373 } 374 KASSERT(age >= 0, ("age %d", age)); 375 M_AGE_SET(m, age); 376 m->m_nextpkt = NULL; 377 qhead->tail = m; 378 qhead->len++; 379 qlen = ++(psq->psq_len); 380 381 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni, 382 "save frame with age %d, %u now queued", age, qlen); 383 384 if (qlen == 1 && vap->iv_set_tim != NULL) 385 vap->iv_set_tim(ni, 1); 386 387 return 0; 388 } 389 390 /* 391 * Move frames from the ps q to the vap's send queue 392 * and/or the driver's send queue; and kick the start 393 * method for each, as appropriate. Note we're careful 394 * to preserve packet ordering here. 395 */ 396 static void 397 pwrsave_flushq(struct ieee80211_node *ni) 398 { 399 struct ieee80211_psq *psq = &ni->ni_psq; 400 struct ieee80211vap *vap = ni->ni_vap; 401 struct ieee80211_psq_head *qhead; 402 struct ifnet *parent, *ifp; 403 404 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni, 405 "flush ps queue, %u packets queued", psq->psq_len); 406 407 qhead = &psq->psq_head[0]; /* 802.11 frames */ 408 if (qhead->head != NULL) { 409 /* XXX could dispatch through vap and check M_ENCAP */ 410 parent = vap->iv_ic->ic_ifp; 411 /* XXX need different driver interface */ 412 /* XXX bypasses q max and OACTIVE */ 413 IF_PREPEND_LIST(&parent->if_snd, qhead->head, qhead->tail, 414 qhead->len); 415 qhead->head = qhead->tail = NULL; 416 qhead->len = 0; 417 } else 418 parent = NULL; 419 420 qhead = &psq->psq_head[1]; /* 802.3 frames */ 421 if (qhead->head != NULL) { 422 ifp = vap->iv_ifp; 423 /* XXX need different driver interface */ 424 /* XXX bypasses q max and OACTIVE */ 425 IF_PREPEND_LIST(&ifp->if_snd, qhead->head, qhead->tail, 426 qhead->len); 427 qhead->head = qhead->tail = NULL; 428 qhead->len = 0; 429 } else 430 ifp = NULL; 431 psq->psq_len = 0; 432 433 /* NB: do this outside the psq lock */ 434 /* XXX packets might get reordered if parent is OACTIVE */ 435 if (parent != NULL) 436 parent->if_start(parent); 437 if (ifp != NULL) 438 ifp->if_start(ifp); 439 } 440 441 /* 442 * Handle station power-save state change. 443 */ 444 void 445 ieee80211_node_pwrsave(struct ieee80211_node *ni, int enable) 446 { 447 struct ieee80211vap *vap = ni->ni_vap; 448 int update; 449 450 update = 0; 451 if (enable) { 452 if ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) { 453 vap->iv_ps_sta++; 454 update = 1; 455 } 456 ni->ni_flags |= IEEE80211_NODE_PWR_MGT; 457 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni, 458 "power save mode on, %u sta's in ps mode", vap->iv_ps_sta); 459 460 if (update) 461 vap->iv_update_ps(vap, vap->iv_ps_sta); 462 } else { 463 if (ni->ni_flags & IEEE80211_NODE_PWR_MGT) { 464 vap->iv_ps_sta--; 465 update = 1; 466 } 467 ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT; 468 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni, 469 "power save mode off, %u sta's in ps mode", vap->iv_ps_sta); 470 471 /* NB: order here is intentional so TIM is clear before flush */ 472 if (vap->iv_set_tim != NULL) 473 vap->iv_set_tim(ni, 0); 474 if (update) { 475 /* NB if no sta's in ps, driver should flush mc q */ 476 vap->iv_update_ps(vap, vap->iv_ps_sta); 477 } 478 if (ni->ni_psq.psq_len != 0) 479 pwrsave_flushq(ni); 480 } 481 } 482 483 /* 484 * Handle power-save state change in station mode. 485 */ 486 void 487 ieee80211_sta_pwrsave(struct ieee80211vap *vap, int enable) 488 { 489 struct ieee80211_node *ni = vap->iv_bss; 490 491 if (!((enable != 0) ^ ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) != 0))) 492 return; 493 494 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni, 495 "sta power save mode %s", enable ? "on" : "off"); 496 if (!enable) { 497 ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT; 498 ieee80211_send_nulldata(ieee80211_ref_node(ni)); 499 /* 500 * Flush any queued frames; we can do this immediately 501 * because we know they'll be queued behind the null 502 * data frame we send the ap. 503 * XXX can we use a data frame to take us out of ps? 504 */ 505 if (ni->ni_psq.psq_len != 0) 506 pwrsave_flushq(ni); 507 } else { 508 ni->ni_flags |= IEEE80211_NODE_PWR_MGT; 509 ieee80211_send_nulldata(ieee80211_ref_node(ni)); 510 } 511 } 512