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/* 28 * IEEE 802.11 scanning support. 29 */ 30#include "opt_wlan.h" 31 32#include <sys/param.h> 33#include <sys/systm.h> 34#include <sys/proc.h> 35#include <sys/kernel.h> 36#include <sys/malloc.h> 37#include <sys/condvar.h> 38 39#include <sys/socket.h> 40 41#include <net/if.h> 42#include <net/if_var.h> 43#include <net/if_media.h> 44#include <net/if_private.h> 45#include <net/ethernet.h> 46 47#include <net80211/ieee80211_var.h> 48 49#include <net80211/ieee80211_scan_sw.h> 50 51#include <net/bpf.h> 52 53struct scan_state { 54 struct ieee80211_scan_state base; /* public state */ 55 56 u_int ss_iflags; /* flags used internally */ 57#define ISCAN_MINDWELL 0x0001 /* min dwell time reached */ 58#define ISCAN_DISCARD 0x0002 /* discard rx'd frames */ 59#define ISCAN_INTERRUPT 0x0004 /* interrupt current scan */ 60#define ISCAN_CANCEL 0x0008 /* cancel current scan */ 61#define ISCAN_PAUSE (ISCAN_INTERRUPT | ISCAN_CANCEL) 62#define ISCAN_ABORT 0x0010 /* end the scan immediately */ 63#define ISCAN_RUNNING 0x0020 /* scan was started */ 64 65 unsigned long ss_chanmindwell; /* min dwell on curchan */ 66 unsigned long ss_scanend; /* time scan must stop */ 67 u_int ss_duration; /* duration for next scan */ 68 struct task ss_scan_start; /* scan start */ 69 struct timeout_task ss_scan_curchan; /* scan execution */ 70}; 71#define SCAN_PRIVATE(ss) ((struct scan_state *) ss) 72 73/* 74 * Amount of time to go off-channel during a background 75 * scan. This value should be large enough to catch most 76 * ap's but short enough that we can return on-channel 77 * before our listen interval expires. 78 * 79 * XXX tunable 80 * XXX check against configured listen interval 81 */ 82#define IEEE80211_SCAN_OFFCHANNEL msecs_to_ticks(150) 83 84static void scan_curchan(struct ieee80211_scan_state *, unsigned long); 85static void scan_mindwell(struct ieee80211_scan_state *); 86static void scan_signal(struct ieee80211_scan_state *, int); 87static void scan_signal_locked(struct ieee80211_scan_state *, int); 88static void scan_start(void *, int); 89static void scan_curchan_task(void *, int); 90static void scan_end(struct ieee80211_scan_state *, int); 91static void scan_done(struct ieee80211_scan_state *, int); 92 93MALLOC_DEFINE(M_80211_SCAN, "80211scan", "802.11 scan state"); 94 95static void 96ieee80211_swscan_detach(struct ieee80211com *ic) 97{ 98 struct ieee80211_scan_state *ss = ic->ic_scan; 99 100 if (ss != NULL) { 101 scan_signal(ss, ISCAN_ABORT); 102 ieee80211_draintask(ic, &SCAN_PRIVATE(ss)->ss_scan_start); 103 taskqueue_drain_timeout(ic->ic_tq, 104 &SCAN_PRIVATE(ss)->ss_scan_curchan); 105 KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0, 106 ("scan still running")); 107 108 /* 109 * For now, do the ss_ops detach here rather 110 * than ieee80211_scan_detach(). 111 * 112 * I'll figure out how to cleanly split things up 113 * at a later date. 114 */ 115 if (ss->ss_ops != NULL) { 116 ss->ss_ops->scan_detach(ss); 117 ss->ss_ops = NULL; 118 } 119 ic->ic_scan = NULL; 120 IEEE80211_FREE(SCAN_PRIVATE(ss), M_80211_SCAN); 121 } 122} 123 124static void 125ieee80211_swscan_vattach(struct ieee80211vap *vap) 126{ 127 /* nothing to do for now */ 128 /* 129 * TODO: all of the vap scan calls should be methods! 130 */ 131 132} 133 134static void 135ieee80211_swscan_vdetach(struct ieee80211vap *vap) 136{ 137 struct ieee80211com *ic = vap->iv_ic; 138 struct ieee80211_scan_state *ss = ic->ic_scan; 139 140 IEEE80211_LOCK_ASSERT(ic); 141 142 if (ss != NULL && ss->ss_vap == vap && 143 (ic->ic_flags & IEEE80211_F_SCAN)) 144 scan_signal_locked(ss, ISCAN_ABORT); 145} 146 147static void 148ieee80211_swscan_set_scan_duration(struct ieee80211vap *vap, u_int duration) 149{ 150 struct ieee80211com *ic = vap->iv_ic; 151 struct ieee80211_scan_state *ss = ic->ic_scan; 152 153 IEEE80211_LOCK_ASSERT(ic); 154 155 /* NB: flush frames rx'd before 1st channel change */ 156 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD; 157 SCAN_PRIVATE(ss)->ss_duration = duration; 158} 159 160/* 161 * Start a scan unless one is already going. 162 */ 163static int 164ieee80211_swscan_start_scan_locked(const struct ieee80211_scanner *scan, 165 struct ieee80211vap *vap, int flags, u_int duration, 166 u_int mindwell, u_int maxdwell, 167 u_int nssid, const struct ieee80211_scan_ssid ssids[]) 168{ 169 struct ieee80211com *ic = vap->iv_ic; 170 struct ieee80211_scan_state *ss = ic->ic_scan; 171 172 IEEE80211_LOCK_ASSERT(ic); 173 174 if (ic->ic_flags & IEEE80211_F_CSAPENDING) { 175 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 176 "%s: scan inhibited by pending channel change\n", __func__); 177 } else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) { 178 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 179 "%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n" 180 , __func__ 181 , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive" 182 , duration, mindwell, maxdwell 183 , ieee80211_phymode_name[vap->iv_des_mode] 184 , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append" 185 , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : "" 186 , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : "" 187 , flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : "" 188 , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : "" 189 , flags & IEEE80211_SCAN_ONCE ? ", once" : "" 190 ); 191 192 ieee80211_scan_update_locked(vap, scan); 193 if (ss->ss_ops != NULL) { 194 if ((flags & IEEE80211_SCAN_NOSSID) == 0) 195 ieee80211_scan_copy_ssid(vap, ss, nssid, ssids); 196 197 ss->ss_flags = flags & IEEE80211_SCAN_PUBLIC_MASK; 198 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 199 vap->iv_stats.is_scan_active++; 200 else 201 vap->iv_stats.is_scan_passive++; 202 if (flags & IEEE80211_SCAN_FLUSH) 203 ss->ss_ops->scan_flush(ss); 204 if (flags & IEEE80211_SCAN_BGSCAN) 205 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN; 206 207 /* Set duration for this particular scan */ 208 ieee80211_swscan_set_scan_duration(vap, duration); 209 210 ss->ss_next = 0; 211 ss->ss_mindwell = mindwell; 212 ss->ss_maxdwell = maxdwell; 213 /* NB: scan_start must be before the scan runtask */ 214 ss->ss_ops->scan_start(ss, vap); 215#ifdef IEEE80211_DEBUG 216 if (ieee80211_msg_scan(vap)) 217 ieee80211_scan_dump(ss); 218#endif /* IEEE80211_DEBUG */ 219 ic->ic_flags |= IEEE80211_F_SCAN; 220 221 /* Start scan task */ 222 ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_start); 223 } 224 return 1; 225 } else { 226 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 227 "%s: %s scan already in progress\n", __func__, 228 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"); 229 } 230 return 0; 231} 232 233/* 234 * Start a scan unless one is already going. 235 * 236 * Called without the comlock held; grab the comlock as appropriate. 237 */ 238static int 239ieee80211_swscan_start_scan(const struct ieee80211_scanner *scan, 240 struct ieee80211vap *vap, int flags, 241 u_int duration, u_int mindwell, u_int maxdwell, 242 u_int nssid, const struct ieee80211_scan_ssid ssids[]) 243{ 244 struct ieee80211com *ic = vap->iv_ic; 245 int result; 246 247 IEEE80211_UNLOCK_ASSERT(ic); 248 249 IEEE80211_LOCK(ic); 250 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration, 251 mindwell, maxdwell, nssid, ssids); 252 IEEE80211_UNLOCK(ic); 253 254 return result; 255} 256 257/* 258 * Check the scan cache for an ap/channel to use; if that 259 * fails then kick off a new scan. 260 * 261 * Called with the comlock held. 262 * 263 * XXX TODO: split out! 264 */ 265static int 266ieee80211_swscan_check_scan(const struct ieee80211_scanner *scan, 267 struct ieee80211vap *vap, int flags, 268 u_int duration, u_int mindwell, u_int maxdwell, 269 u_int nssid, const struct ieee80211_scan_ssid ssids[]) 270{ 271 struct ieee80211com *ic = vap->iv_ic; 272 struct ieee80211_scan_state *ss = ic->ic_scan; 273 int result; 274 275 IEEE80211_LOCK_ASSERT(ic); 276 277 if (ss->ss_ops != NULL) { 278 /* XXX verify ss_ops matches vap->iv_opmode */ 279 if ((flags & IEEE80211_SCAN_NOSSID) == 0) { 280 /* 281 * Update the ssid list and mark flags so if 282 * we call start_scan it doesn't duplicate work. 283 */ 284 ieee80211_scan_copy_ssid(vap, ss, nssid, ssids); 285 flags |= IEEE80211_SCAN_NOSSID; 286 } 287 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 && 288 (flags & IEEE80211_SCAN_FLUSH) == 0 && 289 ieee80211_time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) { 290 /* 291 * We're not currently scanning and the cache is 292 * deemed hot enough to consult. Lock out others 293 * by marking IEEE80211_F_SCAN while we decide if 294 * something is already in the scan cache we can 295 * use. Also discard any frames that might come 296 * in while temporarily marked as scanning. 297 */ 298 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 299 "cache hot; ic_lastscan=%d, scanvalid=%d, ticks=%d\n", 300 ic->ic_lastscan, 301 vap->iv_scanvalid, 302 ticks); 303 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD; 304 ic->ic_flags |= IEEE80211_F_SCAN; 305 306 /* NB: need to use supplied flags in check */ 307 ss->ss_flags = flags & IEEE80211_SCAN_PUBLIC_MASK; 308 result = ss->ss_ops->scan_end(ss, vap); 309 310 ic->ic_flags &= ~IEEE80211_F_SCAN; 311 SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD; 312 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 313 "%s: scan_end returned %d\n", __func__, result); 314 if (result) { 315 ieee80211_notify_scan_done(vap); 316 return 1; 317 } 318 } 319 } 320 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration, 321 mindwell, maxdwell, nssid, ssids); 322 323 return result; 324} 325 326/* 327 * Restart a previous scan. If the previous scan completed 328 * then we start again using the existing channel list. 329 */ 330static int 331ieee80211_swscan_bg_scan(const struct ieee80211_scanner *scan, 332 struct ieee80211vap *vap, int flags) 333{ 334 struct ieee80211com *ic = vap->iv_ic; 335 struct ieee80211_scan_state *ss = ic->ic_scan; 336 bool scanning; 337 338 /* XXX assert unlocked? */ 339 // IEEE80211_UNLOCK_ASSERT(ic); 340 341 IEEE80211_LOCK(ic); 342 scanning = ic->ic_flags & IEEE80211_F_SCAN; 343 if (!scanning) { 344 u_int duration; 345 /* 346 * Go off-channel for a fixed interval that is large 347 * enough to catch most ap's but short enough that 348 * we can return on-channel before our listen interval 349 * expires. 350 */ 351 duration = IEEE80211_SCAN_OFFCHANNEL; 352 353 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 354 "%s: %s scan, ticks %u duration %u\n", __func__, 355 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive", 356 ticks, duration); 357 358 ieee80211_scan_update_locked(vap, scan); 359 if (ss->ss_ops != NULL) { 360 ss->ss_vap = vap; 361 /* 362 * A background scan does not select a new sta; it 363 * just refreshes the scan cache. Also, indicate 364 * the scan logic should follow the beacon schedule: 365 * we go off-channel and scan for a while, then 366 * return to the bss channel to receive a beacon, 367 * then go off-channel again. All during this time 368 * we notify the ap we're in power save mode. When 369 * the scan is complete we leave power save mode. 370 * If any beacon indicates there are frames pending 371 * for us then we drop out of power save mode 372 * (and background scan) automatically by way of the 373 * usual sta power save logic. 374 */ 375 ss->ss_flags |= IEEE80211_SCAN_NOPICK 376 | IEEE80211_SCAN_BGSCAN 377 | flags 378 ; 379 /* if previous scan completed, restart */ 380 if (ss->ss_next >= ss->ss_last) { 381 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 382 vap->iv_stats.is_scan_active++; 383 else 384 vap->iv_stats.is_scan_passive++; 385 /* 386 * NB: beware of the scan cache being flushed; 387 * if the channel list is empty use the 388 * scan_start method to populate it. 389 */ 390 ss->ss_next = 0; 391 if (ss->ss_last != 0) { 392 ieee80211_notify_scan_done(vap); 393 ss->ss_ops->scan_restart(ss, vap); 394 } else { 395 ss->ss_ops->scan_start(ss, vap); 396#ifdef IEEE80211_DEBUG 397 if (ieee80211_msg_scan(vap)) 398 ieee80211_scan_dump(ss); 399#endif /* IEEE80211_DEBUG */ 400 } 401 } 402 ieee80211_swscan_set_scan_duration(vap, duration); 403 ss->ss_maxdwell = duration; 404 ic->ic_flags |= IEEE80211_F_SCAN; 405 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN; 406 ieee80211_runtask(ic, 407 &SCAN_PRIVATE(ss)->ss_scan_start); 408 scanning = true; 409 } else { 410 /* XXX msg+stat */ 411 } 412 } else { 413 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 414 "%s: %s scan already in progress\n", __func__, 415 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"); 416 } 417 IEEE80211_UNLOCK(ic); 418 419 return (scanning); 420} 421 422/* 423 * Taskqueue work to cancel a scan. 424 * 425 * Note: for offload scan devices, we may want to call into the 426 * driver to try and cancel scanning, however it may not be cancelable. 427 */ 428static void 429cancel_scan(struct ieee80211vap *vap, int any, const char *func) 430{ 431 struct ieee80211com *ic = vap->iv_ic; 432 struct ieee80211_scan_state *ss = ic->ic_scan; 433 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 434 int signal; 435 436 IEEE80211_LOCK(ic); 437 signal = any ? ISCAN_PAUSE : ISCAN_CANCEL; 438 if ((ic->ic_flags & IEEE80211_F_SCAN) && 439 (any || ss->ss_vap == vap) && 440 (ss_priv->ss_iflags & signal) == 0) { 441 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 442 "%s: %s %s scan\n", func, 443 any ? "pause" : "cancel", 444 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? 445 "active" : "passive"); 446 447 /* clear bg scan NOPICK */ 448 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 449 /* mark request and wake up the scan task */ 450 scan_signal_locked(ss, signal); 451 } else { 452 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 453 "%s: called; F_SCAN=%d, vap=%s, signal=%d\n", 454 func, 455 !! (ic->ic_flags & IEEE80211_F_SCAN), 456 (ss->ss_vap == vap ? "match" : "nomatch"), 457 !! (ss_priv->ss_iflags & signal)); 458 } 459 IEEE80211_UNLOCK(ic); 460} 461 462/* 463 * Cancel any scan currently going on for the specified vap. 464 */ 465static void 466ieee80211_swscan_cancel_scan(struct ieee80211vap *vap) 467{ 468 cancel_scan(vap, 0, __func__); 469} 470 471/* 472 * Cancel any scan currently going on. 473 */ 474static void 475ieee80211_swscan_cancel_anyscan(struct ieee80211vap *vap) 476{ 477 478 /* XXX for now - just don't do this per packet. */ 479 if (vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) 480 return; 481 482 cancel_scan(vap, 1, __func__); 483} 484 485/* 486 * Manually switch to the next channel in the channel list. 487 * Provided for drivers that manage scanning themselves 488 * (e.g. for firmware-based devices). 489 */ 490static void 491ieee80211_swscan_scan_next(struct ieee80211vap *vap) 492{ 493 struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan; 494 495 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__); 496 497 /* wake up the scan task */ 498 scan_signal(ss, 0); 499} 500 501/* 502 * Manually stop a scan that is currently running. 503 * Provided for drivers that are not able to scan single channels 504 * (e.g. for firmware-based devices). 505 */ 506static void 507ieee80211_swscan_scan_done(struct ieee80211vap *vap) 508{ 509 struct ieee80211com *ic = vap->iv_ic; 510 struct ieee80211_scan_state *ss = ic->ic_scan; 511 512 IEEE80211_LOCK_ASSERT(ic); 513 514 scan_signal_locked(ss, 0); 515} 516 517/* 518 * Probe the current channel, if allowed, while scanning. 519 * If the channel is not marked passive-only then send 520 * a probe request immediately. Otherwise mark state and 521 * listen for beacons on the channel; if we receive something 522 * then we'll transmit a probe request. 523 */ 524static void 525ieee80211_swscan_probe_curchan(struct ieee80211vap *vap, int force) 526{ 527 struct ieee80211com *ic = vap->iv_ic; 528 struct ieee80211_scan_state *ss = ic->ic_scan; 529 struct ifnet *ifp = vap->iv_ifp; 530 int i; 531 532 /* 533 * Full-offload scan devices don't require this. 534 */ 535 if (vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) 536 return; 537 538 /* 539 * Send directed probe requests followed by any 540 * broadcast probe request. 541 * XXX remove dependence on ic/vap->iv_bss 542 */ 543 for (i = 0; i < ss->ss_nssid; i++) 544 ieee80211_send_probereq(vap->iv_bss, 545 vap->iv_myaddr, ifp->if_broadcastaddr, 546 ifp->if_broadcastaddr, 547 ss->ss_ssid[i].ssid, ss->ss_ssid[i].len); 548 if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0) 549 ieee80211_send_probereq(vap->iv_bss, 550 vap->iv_myaddr, ifp->if_broadcastaddr, 551 ifp->if_broadcastaddr, 552 "", 0); 553} 554 555/* 556 * Scan curchan. If this is an active scan and the channel 557 * is not marked passive then send probe request frame(s). 558 * Arrange for the channel change after maxdwell ticks. 559 */ 560static void 561scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell) 562{ 563 struct ieee80211vap *vap = ss->ss_vap; 564 struct ieee80211com *ic = ss->ss_ic; 565 566 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 567 "%s: calling; maxdwell=%lu\n", 568 __func__, 569 maxdwell); 570 IEEE80211_LOCK(ic); 571 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 572 ieee80211_probe_curchan(vap, 0); 573 taskqueue_enqueue_timeout(ic->ic_tq, 574 &SCAN_PRIVATE(ss)->ss_scan_curchan, maxdwell); 575 IEEE80211_UNLOCK(ic); 576} 577 578static void 579scan_signal(struct ieee80211_scan_state *ss, int iflags) 580{ 581 struct ieee80211com *ic = ss->ss_ic; 582 583 IEEE80211_UNLOCK_ASSERT(ic); 584 585 IEEE80211_LOCK(ic); 586 scan_signal_locked(ss, iflags); 587 IEEE80211_UNLOCK(ic); 588} 589 590static void 591scan_signal_locked(struct ieee80211_scan_state *ss, int iflags) 592{ 593 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 594 struct timeout_task *scan_task = &ss_priv->ss_scan_curchan; 595 struct ieee80211com *ic = ss->ss_ic; 596 597 IEEE80211_LOCK_ASSERT(ic); 598 599 ss_priv->ss_iflags |= iflags; 600 if (ss_priv->ss_iflags & ISCAN_RUNNING) { 601 if (taskqueue_cancel_timeout(ic->ic_tq, scan_task, NULL) == 0) 602 taskqueue_enqueue_timeout(ic->ic_tq, scan_task, 0); 603 } 604} 605 606/* 607 * Handle mindwell requirements completed; initiate a channel 608 * change to the next channel asap. 609 */ 610static void 611scan_mindwell(struct ieee80211_scan_state *ss) 612{ 613 614 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: called\n", 615 __func__); 616 617 scan_signal(ss, 0); 618} 619 620static void 621scan_start(void *arg, int pending) 622{ 623#define ISCAN_REP (ISCAN_MINDWELL | ISCAN_DISCARD) 624 struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg; 625 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 626 struct ieee80211vap *vap = ss->ss_vap; 627 struct ieee80211com *ic = ss->ss_ic; 628 629 IEEE80211_LOCK(ic); 630 if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 || 631 (ss_priv->ss_iflags & ISCAN_ABORT)) { 632 /* Cancelled before we started */ 633 scan_done(ss, 0); 634 return; 635 } 636 637 if (ss->ss_next == ss->ss_last) { 638 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 639 "%s: no channels to scan\n", __func__); 640 scan_done(ss, 1); 641 return; 642 } 643 644 /* 645 * Put the station into power save mode. 646 * 647 * This is only required if we're not a full-offload devices; 648 * those devices manage scan/traffic differently. 649 */ 650 if (((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) == 0) && 651 vap->iv_opmode == IEEE80211_M_STA && 652 vap->iv_state == IEEE80211_S_RUN) { 653 if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) { 654 /* Enable station power save mode */ 655 vap->iv_sta_ps(vap, 1); 656 /* Wait until null data frame will be ACK'ed */ 657 mtx_sleep(vap, IEEE80211_LOCK_OBJ(ic), PCATCH, 658 "sta_ps", msecs_to_ticks(10)); 659 if (ss_priv->ss_iflags & ISCAN_ABORT) { 660 scan_done(ss, 0); 661 return; 662 } 663 } 664 } 665 666 ss_priv->ss_scanend = ticks + ss_priv->ss_duration; 667 668 /* XXX scan state can change! Re-validate scan state! */ 669 670 IEEE80211_UNLOCK(ic); 671 672 ic->ic_scan_start(ic); /* notify driver */ 673 674 scan_curchan_task(ss, 0); 675} 676 677static void 678scan_curchan_task(void *arg, int pending __unused) 679{ 680 struct ieee80211_scan_state *ss = arg; 681 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 682 struct ieee80211com *ic = ss->ss_ic; 683 struct ieee80211_channel *chan; 684 unsigned long maxdwell; 685 int scandone, scanstop; 686 687 IEEE80211_LOCK(ic); 688end: 689 /* 690 * Note: only /end/ the scan if we're CANCEL rather than 691 * CANCEL+INTERRUPT (ie, 'PAUSE'). 692 * 693 * We can stop the scan if we hit cancel, but we shouldn't 694 * call scan_end(ss, 1) if we're just PAUSEing the scan. 695 */ 696 scandone = (ss->ss_next >= ss->ss_last) || 697 ((ss_priv->ss_iflags & ISCAN_PAUSE) == ISCAN_CANCEL); 698 scanstop = (ss->ss_next >= ss->ss_last) || 699 ((ss_priv->ss_iflags & ISCAN_CANCEL) != 0); 700 701 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, 702 "%s: loop start; scandone=%d, scanstop=%d, ss_iflags=0x%x, ss_next=%u, ss_last=%u\n", 703 __func__, 704 scandone, 705 scanstop, 706 (uint32_t) ss_priv->ss_iflags, 707 (uint32_t) ss->ss_next, 708 (uint32_t) ss->ss_last); 709 710 if (scanstop || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) || 711 (ss_priv->ss_iflags & ISCAN_ABORT) || 712 ieee80211_time_after(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) { 713 ss_priv->ss_iflags &= ~ISCAN_RUNNING; 714 scan_end(ss, scandone); 715 return; 716 } else 717 ss_priv->ss_iflags |= ISCAN_RUNNING; 718 719 chan = ss->ss_chans[ss->ss_next++]; 720 721 /* 722 * Watch for truncation due to the scan end time. 723 */ 724 if (ieee80211_time_after(ticks + ss->ss_maxdwell, ss_priv->ss_scanend)) 725 maxdwell = ss_priv->ss_scanend - ticks; 726 else 727 maxdwell = ss->ss_maxdwell; 728 729 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, 730 "%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n", 731 __func__, 732 ieee80211_chan2ieee(ic, ic->ic_curchan), 733 ieee80211_channel_type_char(ic->ic_curchan), 734 ieee80211_chan2ieee(ic, chan), 735 ieee80211_channel_type_char(chan), 736 (ss->ss_flags & IEEE80211_SCAN_ACTIVE) && 737 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ? 738 "active" : "passive", 739 ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell)); 740 741 /* 742 * Potentially change channel and phy mode. 743 */ 744 ic->ic_curchan = chan; 745 ic->ic_rt = ieee80211_get_ratetable(chan); 746 IEEE80211_UNLOCK(ic); 747 /* 748 * Perform the channel change and scan unlocked so the driver 749 * may sleep. Once set_channel returns the hardware has 750 * completed the channel change. 751 */ 752 ic->ic_set_channel(ic); 753 ieee80211_radiotap_chan_change(ic); 754 755 /* 756 * Scan curchan. Drivers for "intelligent hardware" 757 * override ic_scan_curchan to tell the device to do 758 * the work. Otherwise we manage the work ourselves; 759 * sending a probe request (as needed), and arming the 760 * timeout to switch channels after maxdwell ticks. 761 * 762 * scan_curchan should only pause for the time required to 763 * prepare/initiate the hardware for the scan (if at all). 764 */ 765 ic->ic_scan_curchan(ss, maxdwell); 766 IEEE80211_LOCK(ic); 767 768 /* XXX scan state can change! Re-validate scan state! */ 769 770 ss_priv->ss_chanmindwell = ticks + ss->ss_mindwell; 771 /* clear mindwell lock and initial channel change flush */ 772 ss_priv->ss_iflags &= ~ISCAN_REP; 773 774 if (ss_priv->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)) { 775 taskqueue_cancel_timeout(ic->ic_tq, &ss_priv->ss_scan_curchan, 776 NULL); 777 goto end; 778 } 779 780 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: waiting\n", 781 __func__); 782 IEEE80211_UNLOCK(ic); 783} 784 785static void 786scan_end(struct ieee80211_scan_state *ss, int scandone) 787{ 788 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 789 struct ieee80211vap *vap = ss->ss_vap; 790 struct ieee80211com *ic = ss->ss_ic; 791 792 IEEE80211_LOCK_ASSERT(ic); 793 794 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: out\n", __func__); 795 796 if (ss_priv->ss_iflags & ISCAN_ABORT) { 797 scan_done(ss, scandone); 798 return; 799 } 800 801 IEEE80211_UNLOCK(ic); 802 ic->ic_scan_end(ic); /* notify driver */ 803 IEEE80211_LOCK(ic); 804 /* XXX scan state can change! Re-validate scan state! */ 805 806 /* 807 * Since a cancellation may have occurred during one of the 808 * driver calls (whilst unlocked), update scandone. 809 */ 810 if ((scandone == 0) && ((ss_priv->ss_iflags & ISCAN_PAUSE) == ISCAN_CANCEL)) { 811 /* XXX printf? */ 812 if_printf(vap->iv_ifp, 813 "%s: OOPS! scan cancelled during driver call (1) (ss_iflags=0x%x)!\n", 814 __func__, 815 ss_priv->ss_iflags); 816 scandone = 1; 817 } 818 819 /* 820 * Record scan complete time. Note that we also do 821 * this when canceled so any background scan will 822 * not be restarted for a while. 823 */ 824 if (scandone) 825 ic->ic_lastscan = ticks; 826 /* return to the bss channel */ 827 if (ic->ic_bsschan != IEEE80211_CHAN_ANYC && 828 ic->ic_curchan != ic->ic_bsschan) { 829 ieee80211_setupcurchan(ic, ic->ic_bsschan); 830 IEEE80211_UNLOCK(ic); 831 ic->ic_set_channel(ic); 832 ieee80211_radiotap_chan_change(ic); 833 IEEE80211_LOCK(ic); 834 } 835 /* clear internal flags and any indication of a pick */ 836 ss_priv->ss_iflags &= ~ISCAN_REP; 837 ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK; 838 839 /* 840 * If not canceled and scan completed, do post-processing. 841 * If the callback function returns 0, then it wants to 842 * continue/restart scanning. Unfortunately we needed to 843 * notify the driver to end the scan above to avoid having 844 * rx frames alter the scan candidate list. 845 */ 846 if ((ss_priv->ss_iflags & ISCAN_CANCEL) == 0 && 847 !ss->ss_ops->scan_end(ss, vap) && 848 (ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 && 849 ieee80211_time_before(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) { 850 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 851 "%s: done, restart " 852 "[ticks %u, dwell min %lu scanend %lu]\n", 853 __func__, 854 ticks, ss->ss_mindwell, ss_priv->ss_scanend); 855 ss->ss_next = 0; /* reset to beginning */ 856 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 857 vap->iv_stats.is_scan_active++; 858 else 859 vap->iv_stats.is_scan_passive++; 860 861 ieee80211_notify_scan_done(vap); 862 ss->ss_ops->scan_restart(ss, vap); /* XXX? */ 863 ieee80211_runtask(ic, &ss_priv->ss_scan_start); 864 IEEE80211_UNLOCK(ic); 865 return; 866 } 867 868 /* past here, scandone is ``true'' if not in bg mode */ 869 if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0) 870 scandone = 1; 871 872 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 873 "%s: %s, [ticks %u, dwell min %lu scanend %lu]\n", 874 __func__, scandone ? "done" : "stopped", 875 ticks, ss->ss_mindwell, ss_priv->ss_scanend); 876 877 /* 878 * Since a cancellation may have occurred during one of the 879 * driver calls (whilst unlocked), update scandone. 880 */ 881 if (scandone == 0 && (ss_priv->ss_iflags & ISCAN_PAUSE) == ISCAN_CANCEL) { 882 /* XXX printf? */ 883 if_printf(vap->iv_ifp, 884 "%s: OOPS! scan cancelled during driver call (2) (ss_iflags=0x%x)!\n", 885 __func__, 886 ss_priv->ss_iflags); 887 scandone = 1; 888 } 889 890 scan_done(ss, scandone); 891} 892 893static void 894scan_done(struct ieee80211_scan_state *ss, int scandone) 895{ 896 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 897 struct ieee80211com *ic = ss->ss_ic; 898 struct ieee80211vap *vap = ss->ss_vap; 899 900 IEEE80211_LOCK_ASSERT(ic); 901 902 /* 903 * Clear the SCAN bit first in case frames are 904 * pending on the station power save queue. If 905 * we defer this then the dispatch of the frames 906 * may generate a request to cancel scanning. 907 */ 908 ic->ic_flags &= ~IEEE80211_F_SCAN; 909 910 /* 911 * Drop out of power save mode when a scan has 912 * completed. If this scan was prematurely terminated 913 * because it is a background scan then don't notify 914 * the ap; we'll either return to scanning after we 915 * receive the beacon frame or we'll drop out of power 916 * save mode because the beacon indicates we have frames 917 * waiting for us. 918 */ 919 if (scandone) { 920 /* 921 * If we're not a scan offload device, come back out of 922 * station powersave. Offload devices handle this themselves. 923 */ 924 if ((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) == 0) 925 vap->iv_sta_ps(vap, 0); 926 if (ss->ss_next >= ss->ss_last) { 927 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 928 "%s: Dropping out of scan; ss_next=%u, ss_last=%u\n", 929 __func__, 930 (uint32_t) ss->ss_next, 931 (uint32_t) ss->ss_last); 932 ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN; 933 } 934 935 /* send 'scan done' event if not interrupted due to traffic. */ 936 if (!(ss_priv->ss_iflags & ISCAN_INTERRUPT) || 937 (ss->ss_next >= ss->ss_last)) 938 ieee80211_notify_scan_done(vap); 939 } 940 ss_priv->ss_iflags &= ~(ISCAN_PAUSE | ISCAN_ABORT); 941 ss_priv->ss_scanend = 0; 942 ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST); 943 IEEE80211_UNLOCK(ic); 944#undef ISCAN_REP 945} 946 947/* 948 * Process a beacon or probe response frame. 949 */ 950static void 951ieee80211_swscan_add_scan(struct ieee80211vap *vap, 952 struct ieee80211_channel *curchan, 953 const struct ieee80211_scanparams *sp, 954 const struct ieee80211_frame *wh, 955 int subtype, int rssi, int noise) 956{ 957 struct ieee80211com *ic = vap->iv_ic; 958 struct ieee80211_scan_state *ss = ic->ic_scan; 959 960 /* XXX locking */ 961 /* 962 * Frames received during startup are discarded to avoid 963 * using scan state setup on the initial entry to the timer 964 * callback. This can occur because the device may enable 965 * rx prior to our doing the initial channel change in the 966 * timer routine. 967 */ 968 if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD) 969 return; 970#ifdef IEEE80211_DEBUG 971 if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN)) 972 ieee80211_scan_dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi); 973#endif 974 if (ss->ss_ops != NULL && 975 ss->ss_ops->scan_add(ss, curchan, sp, wh, subtype, rssi, noise)) { 976 /* 977 * If we've reached the min dwell time terminate 978 * the timer so we'll switch to the next channel. 979 */ 980 if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 && 981 ieee80211_time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) { 982 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 983 "%s: chan %3d%c min dwell met (%u > %lu)\n", 984 __func__, 985 ieee80211_chan2ieee(ic, ic->ic_curchan), 986 ieee80211_channel_type_char(ic->ic_curchan), 987 ticks, SCAN_PRIVATE(ss)->ss_chanmindwell); 988 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL; 989 /* 990 * NB: trigger at next clock tick or wait for the 991 * hardware. 992 */ 993 ic->ic_scan_mindwell(ss); 994 } 995 } 996} 997 998static struct ieee80211_scan_methods swscan_methods = { 999 .sc_attach = ieee80211_swscan_attach, 1000 .sc_detach = ieee80211_swscan_detach, 1001 .sc_vattach = ieee80211_swscan_vattach, 1002 .sc_vdetach = ieee80211_swscan_vdetach, 1003 .sc_set_scan_duration = ieee80211_swscan_set_scan_duration, 1004 .sc_start_scan = ieee80211_swscan_start_scan, 1005 .sc_check_scan = ieee80211_swscan_check_scan, 1006 .sc_bg_scan = ieee80211_swscan_bg_scan, 1007 .sc_cancel_scan = ieee80211_swscan_cancel_scan, 1008 .sc_cancel_anyscan = ieee80211_swscan_cancel_anyscan, 1009 .sc_scan_next = ieee80211_swscan_scan_next, 1010 .sc_scan_done = ieee80211_swscan_scan_done, 1011 .sc_scan_probe_curchan = ieee80211_swscan_probe_curchan, 1012 .sc_add_scan = ieee80211_swscan_add_scan 1013}; 1014 1015/* 1016 * Default scan attach method. 1017 */ 1018void 1019ieee80211_swscan_attach(struct ieee80211com *ic) 1020{ 1021 struct scan_state *ss; 1022 1023 /* 1024 * Setup the default methods 1025 */ 1026 ic->ic_scan_methods = &swscan_methods; 1027 1028 /* Allocate initial scan state */ 1029 ss = (struct scan_state *) IEEE80211_MALLOC(sizeof(struct scan_state), 1030 M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 1031 if (ss == NULL) { 1032 ic->ic_scan = NULL; 1033 return; 1034 } 1035 TASK_INIT(&ss->ss_scan_start, 0, scan_start, ss); 1036 TIMEOUT_TASK_INIT(ic->ic_tq, &ss->ss_scan_curchan, 0, 1037 scan_curchan_task, ss); 1038 1039 ic->ic_scan = &ss->base; 1040 ss->base.ss_ic = ic; 1041 1042 ic->ic_scan_curchan = scan_curchan; 1043 ic->ic_scan_mindwell = scan_mindwell; 1044} 1045