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("$FreeBSD$"); 28 29 /* 30 * IEEE 802.11 scanning support. 31 */ 32 #include "opt_wlan.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/proc.h> 37 #include <sys/kernel.h> 38 #include <sys/malloc.h> 39 #include <sys/condvar.h> 40 41 #include <sys/socket.h> 42 43 #include <net/if.h> 44 #include <net/if_var.h> 45 #include <net/if_media.h> 46 #include <net/ethernet.h> 47 48 #include <net80211/ieee80211_var.h> 49 50 #include <net80211/ieee80211_scan_sw.h> 51 52 #include <net/bpf.h> 53 54 struct scan_state { 55 struct ieee80211_scan_state base; /* public state */ 56 57 u_int ss_iflags; /* flags used internally */ 58 #define ISCAN_MINDWELL 0x0001 /* min dwell time reached */ 59 #define ISCAN_DISCARD 0x0002 /* discard rx'd frames */ 60 #define ISCAN_INTERRUPT 0x0004 /* interrupt current scan */ 61 #define ISCAN_CANCEL 0x0008 /* cancel current scan */ 62 #define ISCAN_PAUSE (ISCAN_INTERRUPT | ISCAN_CANCEL) 63 #define ISCAN_ABORT 0x0010 /* end the scan immediately */ 64 #define ISCAN_RUNNING 0x0020 /* scan was started */ 65 66 unsigned long ss_chanmindwell; /* min dwell on curchan */ 67 unsigned long ss_scanend; /* time scan must stop */ 68 u_int ss_duration; /* duration for next scan */ 69 struct task ss_scan_start; /* scan start */ 70 struct timeout_task ss_scan_curchan; /* scan execution */ 71 }; 72 #define SCAN_PRIVATE(ss) ((struct scan_state *) ss) 73 74 /* 75 * Amount of time to go off-channel during a background 76 * scan. This value should be large enough to catch most 77 * ap's but short enough that we can return on-channel 78 * before our listen interval expires. 79 * 80 * XXX tunable 81 * XXX check against configured listen interval 82 */ 83 #define IEEE80211_SCAN_OFFCHANNEL msecs_to_ticks(150) 84 85 static void scan_curchan(struct ieee80211_scan_state *, unsigned long); 86 static void scan_mindwell(struct ieee80211_scan_state *); 87 static void scan_signal(struct ieee80211_scan_state *, int); 88 static void scan_signal_locked(struct ieee80211_scan_state *, int); 89 static void scan_start(void *, int); 90 static void scan_curchan_task(void *, int); 91 static void scan_end(struct ieee80211_scan_state *, int); 92 static void scan_done(struct ieee80211_scan_state *, int); 93 94 MALLOC_DEFINE(M_80211_SCAN, "80211scan", "802.11 scan state"); 95 96 static void 97 ieee80211_swscan_detach(struct ieee80211com *ic) 98 { 99 struct ieee80211_scan_state *ss = ic->ic_scan; 100 101 if (ss != NULL) { 102 scan_signal(ss, ISCAN_ABORT); 103 ieee80211_draintask(ic, &SCAN_PRIVATE(ss)->ss_scan_start); 104 taskqueue_drain_timeout(ic->ic_tq, 105 &SCAN_PRIVATE(ss)->ss_scan_curchan); 106 KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0, 107 ("scan still running")); 108 109 /* 110 * For now, do the ss_ops detach here rather 111 * than ieee80211_scan_detach(). 112 * 113 * I'll figure out how to cleanly split things up 114 * at a later date. 115 */ 116 if (ss->ss_ops != NULL) { 117 ss->ss_ops->scan_detach(ss); 118 ss->ss_ops = NULL; 119 } 120 ic->ic_scan = NULL; 121 IEEE80211_FREE(SCAN_PRIVATE(ss), M_80211_SCAN); 122 } 123 } 124 125 static void 126 ieee80211_swscan_vattach(struct ieee80211vap *vap) 127 { 128 /* nothing to do for now */ 129 /* 130 * TODO: all of the vap scan calls should be methods! 131 */ 132 133 } 134 135 static void 136 ieee80211_swscan_vdetach(struct ieee80211vap *vap) 137 { 138 struct ieee80211com *ic = vap->iv_ic; 139 struct ieee80211_scan_state *ss = ic->ic_scan; 140 141 IEEE80211_LOCK_ASSERT(ic); 142 143 if (ss != NULL && ss->ss_vap == vap && 144 (ic->ic_flags & IEEE80211_F_SCAN)) 145 scan_signal_locked(ss, ISCAN_ABORT); 146 } 147 148 static void 149 ieee80211_swscan_set_scan_duration(struct ieee80211vap *vap, u_int duration) 150 { 151 struct ieee80211com *ic = vap->iv_ic; 152 struct ieee80211_scan_state *ss = ic->ic_scan; 153 154 IEEE80211_LOCK_ASSERT(ic); 155 156 /* NB: flush frames rx'd before 1st channel change */ 157 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD; 158 SCAN_PRIVATE(ss)->ss_duration = duration; 159 } 160 161 /* 162 * Start a scan unless one is already going. 163 */ 164 static int 165 ieee80211_swscan_start_scan_locked(const struct ieee80211_scanner *scan, 166 struct ieee80211vap *vap, int flags, u_int duration, 167 u_int mindwell, u_int maxdwell, 168 u_int nssid, const struct ieee80211_scan_ssid ssids[]) 169 { 170 struct ieee80211com *ic = vap->iv_ic; 171 struct ieee80211_scan_state *ss = ic->ic_scan; 172 173 IEEE80211_LOCK_ASSERT(ic); 174 175 if (ic->ic_flags & IEEE80211_F_CSAPENDING) { 176 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 177 "%s: scan inhibited by pending channel change\n", __func__); 178 } else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) { 179 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 180 "%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n" 181 , __func__ 182 , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive" 183 , duration, mindwell, maxdwell 184 , ieee80211_phymode_name[vap->iv_des_mode] 185 , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append" 186 , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : "" 187 , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : "" 188 , flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : "" 189 , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : "" 190 , flags & IEEE80211_SCAN_ONCE ? ", once" : "" 191 ); 192 193 ieee80211_scan_update_locked(vap, scan); 194 if (ss->ss_ops != NULL) { 195 if ((flags & IEEE80211_SCAN_NOSSID) == 0) 196 ieee80211_scan_copy_ssid(vap, ss, nssid, ssids); 197 198 /* NB: top 4 bits for internal use */ 199 ss->ss_flags = flags & 0xfff; 200 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 201 vap->iv_stats.is_scan_active++; 202 else 203 vap->iv_stats.is_scan_passive++; 204 if (flags & IEEE80211_SCAN_FLUSH) 205 ss->ss_ops->scan_flush(ss); 206 if (flags & IEEE80211_SCAN_BGSCAN) 207 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN; 208 209 /* Set duration for this particular scan */ 210 ieee80211_swscan_set_scan_duration(vap, duration); 211 212 ss->ss_next = 0; 213 ss->ss_mindwell = mindwell; 214 ss->ss_maxdwell = maxdwell; 215 /* NB: scan_start must be before the scan runtask */ 216 ss->ss_ops->scan_start(ss, vap); 217 #ifdef IEEE80211_DEBUG 218 if (ieee80211_msg_scan(vap)) 219 ieee80211_scan_dump(ss); 220 #endif /* IEEE80211_DEBUG */ 221 ic->ic_flags |= IEEE80211_F_SCAN; 222 223 /* Start scan task */ 224 ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_start); 225 } 226 return 1; 227 } else { 228 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 229 "%s: %s scan already in progress\n", __func__, 230 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"); 231 } 232 return 0; 233 } 234 235 236 /* 237 * Start a scan unless one is already going. 238 * 239 * Called without the comlock held; grab the comlock as appropriate. 240 */ 241 static int 242 ieee80211_swscan_start_scan(const struct ieee80211_scanner *scan, 243 struct ieee80211vap *vap, int flags, 244 u_int duration, u_int mindwell, u_int maxdwell, 245 u_int nssid, const struct ieee80211_scan_ssid ssids[]) 246 { 247 struct ieee80211com *ic = vap->iv_ic; 248 int result; 249 250 IEEE80211_UNLOCK_ASSERT(ic); 251 252 IEEE80211_LOCK(ic); 253 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration, 254 mindwell, maxdwell, nssid, ssids); 255 IEEE80211_UNLOCK(ic); 256 257 return result; 258 } 259 260 /* 261 * Check the scan cache for an ap/channel to use; if that 262 * fails then kick off a new scan. 263 * 264 * Called with the comlock held. 265 * 266 * XXX TODO: split out! 267 */ 268 static int 269 ieee80211_swscan_check_scan(const struct ieee80211_scanner *scan, 270 struct ieee80211vap *vap, int flags, 271 u_int duration, u_int mindwell, u_int maxdwell, 272 u_int nssid, const struct ieee80211_scan_ssid ssids[]) 273 { 274 struct ieee80211com *ic = vap->iv_ic; 275 struct ieee80211_scan_state *ss = ic->ic_scan; 276 int result; 277 278 IEEE80211_LOCK_ASSERT(ic); 279 280 if (ss->ss_ops != NULL) { 281 /* XXX verify ss_ops matches vap->iv_opmode */ 282 if ((flags & IEEE80211_SCAN_NOSSID) == 0) { 283 /* 284 * Update the ssid list and mark flags so if 285 * we call start_scan it doesn't duplicate work. 286 */ 287 ieee80211_scan_copy_ssid(vap, ss, nssid, ssids); 288 flags |= IEEE80211_SCAN_NOSSID; 289 } 290 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 && 291 (flags & IEEE80211_SCAN_FLUSH) == 0 && 292 ieee80211_time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) { 293 /* 294 * We're not currently scanning and the cache is 295 * deemed hot enough to consult. Lock out others 296 * by marking IEEE80211_F_SCAN while we decide if 297 * something is already in the scan cache we can 298 * use. Also discard any frames that might come 299 * in while temporarily marked as scanning. 300 */ 301 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD; 302 ic->ic_flags |= IEEE80211_F_SCAN; 303 304 /* NB: need to use supplied flags in check */ 305 ss->ss_flags = flags & 0xff; 306 result = ss->ss_ops->scan_end(ss, vap); 307 308 ic->ic_flags &= ~IEEE80211_F_SCAN; 309 SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD; 310 if (result) { 311 ieee80211_notify_scan_done(vap); 312 return 1; 313 } 314 } 315 } 316 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration, 317 mindwell, maxdwell, nssid, ssids); 318 319 return result; 320 } 321 322 /* 323 * Restart a previous scan. If the previous scan completed 324 * then we start again using the existing channel list. 325 */ 326 static int 327 ieee80211_swscan_bg_scan(const struct ieee80211_scanner *scan, 328 struct ieee80211vap *vap, int flags) 329 { 330 struct ieee80211com *ic = vap->iv_ic; 331 struct ieee80211_scan_state *ss = ic->ic_scan; 332 333 /* XXX assert unlocked? */ 334 // IEEE80211_UNLOCK_ASSERT(ic); 335 336 IEEE80211_LOCK(ic); 337 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) { 338 u_int duration; 339 /* 340 * Go off-channel for a fixed interval that is large 341 * enough to catch most ap's but short enough that 342 * we can return on-channel before our listen interval 343 * expires. 344 */ 345 duration = IEEE80211_SCAN_OFFCHANNEL; 346 347 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 348 "%s: %s scan, ticks %u duration %u\n", __func__, 349 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive", 350 ticks, duration); 351 352 ieee80211_scan_update_locked(vap, scan); 353 if (ss->ss_ops != NULL) { 354 ss->ss_vap = vap; 355 /* 356 * A background scan does not select a new sta; it 357 * just refreshes the scan cache. Also, indicate 358 * the scan logic should follow the beacon schedule: 359 * we go off-channel and scan for a while, then 360 * return to the bss channel to receive a beacon, 361 * then go off-channel again. All during this time 362 * we notify the ap we're in power save mode. When 363 * the scan is complete we leave power save mode. 364 * If any beacon indicates there are frames pending 365 * for us then we drop out of power save mode 366 * (and background scan) automatically by way of the 367 * usual sta power save logic. 368 */ 369 ss->ss_flags |= IEEE80211_SCAN_NOPICK 370 | IEEE80211_SCAN_BGSCAN 371 | flags 372 ; 373 /* if previous scan completed, restart */ 374 if (ss->ss_next >= ss->ss_last) { 375 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 376 vap->iv_stats.is_scan_active++; 377 else 378 vap->iv_stats.is_scan_passive++; 379 /* 380 * NB: beware of the scan cache being flushed; 381 * if the channel list is empty use the 382 * scan_start method to populate it. 383 */ 384 ss->ss_next = 0; 385 if (ss->ss_last != 0) 386 ss->ss_ops->scan_restart(ss, vap); 387 else { 388 ss->ss_ops->scan_start(ss, vap); 389 #ifdef IEEE80211_DEBUG 390 if (ieee80211_msg_scan(vap)) 391 ieee80211_scan_dump(ss); 392 #endif /* IEEE80211_DEBUG */ 393 } 394 } 395 ieee80211_swscan_set_scan_duration(vap, duration); 396 ss->ss_maxdwell = duration; 397 ic->ic_flags |= IEEE80211_F_SCAN; 398 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN; 399 ieee80211_runtask(ic, 400 &SCAN_PRIVATE(ss)->ss_scan_start); 401 } else { 402 /* XXX msg+stat */ 403 } 404 } else { 405 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 406 "%s: %s scan already in progress\n", __func__, 407 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"); 408 } 409 IEEE80211_UNLOCK(ic); 410 411 /* NB: racey, does it matter? */ 412 return (ic->ic_flags & IEEE80211_F_SCAN); 413 } 414 415 static void 416 cancel_scan(struct ieee80211vap *vap, int any, const char *func) 417 { 418 struct ieee80211com *ic = vap->iv_ic; 419 struct ieee80211_scan_state *ss = ic->ic_scan; 420 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 421 int signal; 422 423 IEEE80211_LOCK(ic); 424 signal = any ? ISCAN_PAUSE : ISCAN_CANCEL; 425 if ((ic->ic_flags & IEEE80211_F_SCAN) && 426 (any || ss->ss_vap == vap) && 427 (ss_priv->ss_iflags & signal) == 0) { 428 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 429 "%s: %s %s scan\n", func, 430 any ? "pause" : "cancel", 431 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? 432 "active" : "passive"); 433 434 /* clear bg scan NOPICK */ 435 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 436 /* mark request and wake up the scan task */ 437 scan_signal_locked(ss, signal); 438 } else { 439 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 440 "%s: called; F_SCAN=%d, vap=%s, signal=%d\n", 441 func, 442 !! (ic->ic_flags & IEEE80211_F_SCAN), 443 (ss->ss_vap == vap ? "match" : "nomatch"), 444 !! (ss_priv->ss_iflags & signal)); 445 } 446 IEEE80211_UNLOCK(ic); 447 } 448 449 /* 450 * Cancel any scan currently going on for the specified vap. 451 */ 452 static void 453 ieee80211_swscan_cancel_scan(struct ieee80211vap *vap) 454 { 455 cancel_scan(vap, 0, __func__); 456 } 457 458 /* 459 * Cancel any scan currently going on. 460 */ 461 static void 462 ieee80211_swscan_cancel_anyscan(struct ieee80211vap *vap) 463 { 464 cancel_scan(vap, 1, __func__); 465 } 466 467 /* 468 * Manually switch to the next channel in the channel list. 469 * Provided for drivers that manage scanning themselves 470 * (e.g. for firmware-based devices). 471 */ 472 static void 473 ieee80211_swscan_scan_next(struct ieee80211vap *vap) 474 { 475 struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan; 476 477 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__); 478 479 /* wake up the scan task */ 480 scan_signal(ss, 0); 481 } 482 483 /* 484 * Manually stop a scan that is currently running. 485 * Provided for drivers that are not able to scan single channels 486 * (e.g. for firmware-based devices). 487 */ 488 static void 489 ieee80211_swscan_scan_done(struct ieee80211vap *vap) 490 { 491 struct ieee80211com *ic = vap->iv_ic; 492 struct ieee80211_scan_state *ss = ic->ic_scan; 493 494 IEEE80211_LOCK_ASSERT(ic); 495 496 scan_signal_locked(ss, 0); 497 } 498 499 /* 500 * Probe the current channel, if allowed, while scanning. 501 * If the channel is not marked passive-only then send 502 * a probe request immediately. Otherwise mark state and 503 * listen for beacons on the channel; if we receive something 504 * then we'll transmit a probe request. 505 */ 506 static void 507 ieee80211_swscan_probe_curchan(struct ieee80211vap *vap, int force) 508 { 509 struct ieee80211com *ic = vap->iv_ic; 510 struct ieee80211_scan_state *ss = ic->ic_scan; 511 struct ifnet *ifp = vap->iv_ifp; 512 int i; 513 514 /* 515 * Send directed probe requests followed by any 516 * broadcast probe request. 517 * XXX remove dependence on ic/vap->iv_bss 518 */ 519 for (i = 0; i < ss->ss_nssid; i++) 520 ieee80211_send_probereq(vap->iv_bss, 521 vap->iv_myaddr, ifp->if_broadcastaddr, 522 ifp->if_broadcastaddr, 523 ss->ss_ssid[i].ssid, ss->ss_ssid[i].len); 524 if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0) 525 ieee80211_send_probereq(vap->iv_bss, 526 vap->iv_myaddr, ifp->if_broadcastaddr, 527 ifp->if_broadcastaddr, 528 "", 0); 529 } 530 531 /* 532 * Scan curchan. If this is an active scan and the channel 533 * is not marked passive then send probe request frame(s). 534 * Arrange for the channel change after maxdwell ticks. 535 */ 536 static void 537 scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell) 538 { 539 struct ieee80211vap *vap = ss->ss_vap; 540 struct ieee80211com *ic = ss->ss_ic; 541 542 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 543 "%s: calling; maxdwell=%lu\n", 544 __func__, 545 maxdwell); 546 IEEE80211_LOCK(ic); 547 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 548 ieee80211_probe_curchan(vap, 0); 549 taskqueue_enqueue_timeout(ic->ic_tq, 550 &SCAN_PRIVATE(ss)->ss_scan_curchan, maxdwell); 551 IEEE80211_UNLOCK(ic); 552 } 553 554 static void 555 scan_signal(struct ieee80211_scan_state *ss, int iflags) 556 { 557 struct ieee80211com *ic = ss->ss_ic; 558 559 IEEE80211_UNLOCK_ASSERT(ic); 560 561 IEEE80211_LOCK(ic); 562 scan_signal_locked(ss, iflags); 563 IEEE80211_UNLOCK(ic); 564 } 565 566 static void 567 scan_signal_locked(struct ieee80211_scan_state *ss, int iflags) 568 { 569 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 570 struct timeout_task *scan_task = &ss_priv->ss_scan_curchan; 571 struct ieee80211com *ic = ss->ss_ic; 572 573 IEEE80211_LOCK_ASSERT(ic); 574 575 ss_priv->ss_iflags |= iflags; 576 if (ss_priv->ss_iflags & ISCAN_RUNNING) { 577 if (taskqueue_cancel_timeout(ic->ic_tq, scan_task, NULL) == 0) 578 taskqueue_enqueue_timeout(ic->ic_tq, scan_task, 0); 579 } 580 } 581 582 /* 583 * Handle mindwell requirements completed; initiate a channel 584 * change to the next channel asap. 585 */ 586 static void 587 scan_mindwell(struct ieee80211_scan_state *ss) 588 { 589 590 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: called\n", 591 __func__); 592 593 scan_signal(ss, 0); 594 } 595 596 static void 597 scan_start(void *arg, int pending) 598 { 599 #define ISCAN_REP (ISCAN_MINDWELL | ISCAN_DISCARD) 600 struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg; 601 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 602 struct ieee80211vap *vap = ss->ss_vap; 603 struct ieee80211com *ic = ss->ss_ic; 604 605 IEEE80211_LOCK(ic); 606 if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 || 607 (ss_priv->ss_iflags & ISCAN_ABORT)) { 608 /* Cancelled before we started */ 609 scan_done(ss, 0); 610 return; 611 } 612 613 if (ss->ss_next == ss->ss_last) { 614 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 615 "%s: no channels to scan\n", __func__); 616 scan_done(ss, 1); 617 return; 618 } 619 620 if (vap->iv_opmode == IEEE80211_M_STA && 621 vap->iv_state == IEEE80211_S_RUN) { 622 if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) { 623 /* Enable station power save mode */ 624 vap->iv_sta_ps(vap, 1); 625 /* Wait until null data frame will be ACK'ed */ 626 mtx_sleep(vap, IEEE80211_LOCK_OBJ(ic), PCATCH, 627 "sta_ps", msecs_to_ticks(10)); 628 if (ss_priv->ss_iflags & ISCAN_ABORT) { 629 scan_done(ss, 0); 630 return; 631 } 632 } 633 } 634 635 ss_priv->ss_scanend = ticks + ss_priv->ss_duration; 636 637 /* XXX scan state can change! Re-validate scan state! */ 638 639 IEEE80211_UNLOCK(ic); 640 641 ic->ic_scan_start(ic); /* notify driver */ 642 643 scan_curchan_task(ss, 0); 644 } 645 646 static void 647 scan_curchan_task(void *arg, int pending) 648 { 649 struct ieee80211_scan_state *ss = arg; 650 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 651 struct ieee80211com *ic = ss->ss_ic; 652 struct ieee80211_channel *chan; 653 unsigned long maxdwell; 654 int scandone; 655 656 IEEE80211_LOCK(ic); 657 end: 658 scandone = (ss->ss_next >= ss->ss_last) || 659 (ss_priv->ss_iflags & ISCAN_CANCEL) != 0; 660 661 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, 662 "%s: loop start; scandone=%d\n", 663 __func__, 664 scandone); 665 666 if (scandone || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) || 667 (ss_priv->ss_iflags & ISCAN_ABORT) || 668 ieee80211_time_after(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) { 669 ss_priv->ss_iflags &= ~ISCAN_RUNNING; 670 scan_end(ss, scandone); 671 return; 672 } else 673 ss_priv->ss_iflags |= ISCAN_RUNNING; 674 675 chan = ss->ss_chans[ss->ss_next++]; 676 677 /* 678 * Watch for truncation due to the scan end time. 679 */ 680 if (ieee80211_time_after(ticks + ss->ss_maxdwell, ss_priv->ss_scanend)) 681 maxdwell = ss_priv->ss_scanend - ticks; 682 else 683 maxdwell = ss->ss_maxdwell; 684 685 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, 686 "%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n", 687 __func__, 688 ieee80211_chan2ieee(ic, ic->ic_curchan), 689 ieee80211_channel_type_char(ic->ic_curchan), 690 ieee80211_chan2ieee(ic, chan), 691 ieee80211_channel_type_char(chan), 692 (ss->ss_flags & IEEE80211_SCAN_ACTIVE) && 693 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ? 694 "active" : "passive", 695 ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell)); 696 697 /* 698 * Potentially change channel and phy mode. 699 */ 700 ic->ic_curchan = chan; 701 ic->ic_rt = ieee80211_get_ratetable(chan); 702 IEEE80211_UNLOCK(ic); 703 /* 704 * Perform the channel change and scan unlocked so the driver 705 * may sleep. Once set_channel returns the hardware has 706 * completed the channel change. 707 */ 708 ic->ic_set_channel(ic); 709 ieee80211_radiotap_chan_change(ic); 710 711 /* 712 * Scan curchan. Drivers for "intelligent hardware" 713 * override ic_scan_curchan to tell the device to do 714 * the work. Otherwise we manage the work ourselves; 715 * sending a probe request (as needed), and arming the 716 * timeout to switch channels after maxdwell ticks. 717 * 718 * scan_curchan should only pause for the time required to 719 * prepare/initiate the hardware for the scan (if at all). 720 */ 721 ic->ic_scan_curchan(ss, maxdwell); 722 IEEE80211_LOCK(ic); 723 724 /* XXX scan state can change! Re-validate scan state! */ 725 726 ss_priv->ss_chanmindwell = ticks + ss->ss_mindwell; 727 /* clear mindwell lock and initial channel change flush */ 728 ss_priv->ss_iflags &= ~ISCAN_REP; 729 730 if (ss_priv->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)) { 731 taskqueue_cancel_timeout(ic->ic_tq, &ss_priv->ss_scan_curchan, 732 NULL); 733 goto end; 734 } 735 736 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: waiting\n", 737 __func__); 738 IEEE80211_UNLOCK(ic); 739 } 740 741 static void 742 scan_end(struct ieee80211_scan_state *ss, int scandone) 743 { 744 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 745 struct ieee80211vap *vap = ss->ss_vap; 746 struct ieee80211com *ic = ss->ss_ic; 747 748 IEEE80211_LOCK_ASSERT(ic); 749 750 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: out\n", __func__); 751 752 if (ss_priv->ss_iflags & ISCAN_ABORT) { 753 scan_done(ss, scandone); 754 return; 755 } 756 757 IEEE80211_UNLOCK(ic); 758 ic->ic_scan_end(ic); /* notify driver */ 759 IEEE80211_LOCK(ic); 760 /* XXX scan state can change! Re-validate scan state! */ 761 762 /* 763 * Since a cancellation may have occurred during one of the 764 * driver calls (whilst unlocked), update scandone. 765 */ 766 if (scandone == 0 && (ss_priv->ss_iflags & ISCAN_CANCEL) != 0) { 767 /* XXX printf? */ 768 if_printf(vap->iv_ifp, 769 "%s: OOPS! scan cancelled during driver call (1)!\n", 770 __func__); 771 scandone = 1; 772 } 773 774 /* 775 * Record scan complete time. Note that we also do 776 * this when canceled so any background scan will 777 * not be restarted for a while. 778 */ 779 if (scandone) 780 ic->ic_lastscan = ticks; 781 /* return to the bss channel */ 782 if (ic->ic_bsschan != IEEE80211_CHAN_ANYC && 783 ic->ic_curchan != ic->ic_bsschan) { 784 ieee80211_setupcurchan(ic, ic->ic_bsschan); 785 IEEE80211_UNLOCK(ic); 786 ic->ic_set_channel(ic); 787 ieee80211_radiotap_chan_change(ic); 788 IEEE80211_LOCK(ic); 789 } 790 /* clear internal flags and any indication of a pick */ 791 ss_priv->ss_iflags &= ~ISCAN_REP; 792 ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK; 793 794 /* 795 * If not canceled and scan completed, do post-processing. 796 * If the callback function returns 0, then it wants to 797 * continue/restart scanning. Unfortunately we needed to 798 * notify the driver to end the scan above to avoid having 799 * rx frames alter the scan candidate list. 800 */ 801 if ((ss_priv->ss_iflags & ISCAN_CANCEL) == 0 && 802 !ss->ss_ops->scan_end(ss, vap) && 803 (ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 && 804 ieee80211_time_before(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) { 805 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 806 "%s: done, restart " 807 "[ticks %u, dwell min %lu scanend %lu]\n", 808 __func__, 809 ticks, ss->ss_mindwell, ss_priv->ss_scanend); 810 ss->ss_next = 0; /* reset to beginning */ 811 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 812 vap->iv_stats.is_scan_active++; 813 else 814 vap->iv_stats.is_scan_passive++; 815 816 ss->ss_ops->scan_restart(ss, vap); /* XXX? */ 817 ieee80211_runtask(ic, &ss_priv->ss_scan_start); 818 IEEE80211_UNLOCK(ic); 819 return; 820 } 821 822 /* past here, scandone is ``true'' if not in bg mode */ 823 if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0) 824 scandone = 1; 825 826 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 827 "%s: %s, [ticks %u, dwell min %lu scanend %lu]\n", 828 __func__, scandone ? "done" : "stopped", 829 ticks, ss->ss_mindwell, ss_priv->ss_scanend); 830 831 /* 832 * Since a cancellation may have occurred during one of the 833 * driver calls (whilst unlocked), update scandone. 834 */ 835 if (scandone == 0 && (ss_priv->ss_iflags & ISCAN_CANCEL) != 0) { 836 /* XXX printf? */ 837 if_printf(vap->iv_ifp, 838 "%s: OOPS! scan cancelled during driver call (2)!\n", 839 __func__); 840 scandone = 1; 841 } 842 843 scan_done(ss, scandone); 844 } 845 846 static void 847 scan_done(struct ieee80211_scan_state *ss, int scandone) 848 { 849 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 850 struct ieee80211com *ic = ss->ss_ic; 851 struct ieee80211vap *vap = ss->ss_vap; 852 853 IEEE80211_LOCK_ASSERT(ic); 854 855 /* 856 * Clear the SCAN bit first in case frames are 857 * pending on the station power save queue. If 858 * we defer this then the dispatch of the frames 859 * may generate a request to cancel scanning. 860 */ 861 ic->ic_flags &= ~IEEE80211_F_SCAN; 862 863 /* 864 * Drop out of power save mode when a scan has 865 * completed. If this scan was prematurely terminated 866 * because it is a background scan then don't notify 867 * the ap; we'll either return to scanning after we 868 * receive the beacon frame or we'll drop out of power 869 * save mode because the beacon indicates we have frames 870 * waiting for us. 871 */ 872 if (scandone) { 873 vap->iv_sta_ps(vap, 0); 874 if (ss->ss_next >= ss->ss_last) 875 ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN; 876 877 /* send 'scan done' event if not interrupted due to traffic. */ 878 if (!(ss_priv->ss_iflags & ISCAN_INTERRUPT)) 879 ieee80211_notify_scan_done(vap); 880 } 881 ss_priv->ss_iflags &= ~(ISCAN_PAUSE | ISCAN_ABORT); 882 ss_priv->ss_scanend = 0; 883 ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST); 884 IEEE80211_UNLOCK(ic); 885 #undef ISCAN_REP 886 } 887 888 /* 889 * Process a beacon or probe response frame. 890 */ 891 static void 892 ieee80211_swscan_add_scan(struct ieee80211vap *vap, 893 struct ieee80211_channel *curchan, 894 const struct ieee80211_scanparams *sp, 895 const struct ieee80211_frame *wh, 896 int subtype, int rssi, int noise) 897 { 898 struct ieee80211com *ic = vap->iv_ic; 899 struct ieee80211_scan_state *ss = ic->ic_scan; 900 901 /* XXX locking */ 902 /* 903 * Frames received during startup are discarded to avoid 904 * using scan state setup on the initial entry to the timer 905 * callback. This can occur because the device may enable 906 * rx prior to our doing the initial channel change in the 907 * timer routine. 908 */ 909 if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD) 910 return; 911 #ifdef IEEE80211_DEBUG 912 if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN)) 913 ieee80211_scan_dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi); 914 #endif 915 if (ss->ss_ops != NULL && 916 ss->ss_ops->scan_add(ss, curchan, sp, wh, subtype, rssi, noise)) { 917 /* 918 * If we've reached the min dwell time terminate 919 * the timer so we'll switch to the next channel. 920 */ 921 if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 && 922 ieee80211_time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) { 923 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 924 "%s: chan %3d%c min dwell met (%u > %lu)\n", 925 __func__, 926 ieee80211_chan2ieee(ic, ic->ic_curchan), 927 ieee80211_channel_type_char(ic->ic_curchan), 928 ticks, SCAN_PRIVATE(ss)->ss_chanmindwell); 929 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL; 930 /* 931 * NB: trigger at next clock tick or wait for the 932 * hardware. 933 */ 934 ic->ic_scan_mindwell(ss); 935 } 936 } 937 } 938 939 static struct ieee80211_scan_methods swscan_methods = { 940 .sc_attach = ieee80211_swscan_attach, 941 .sc_detach = ieee80211_swscan_detach, 942 .sc_vattach = ieee80211_swscan_vattach, 943 .sc_vdetach = ieee80211_swscan_vdetach, 944 .sc_set_scan_duration = ieee80211_swscan_set_scan_duration, 945 .sc_start_scan = ieee80211_swscan_start_scan, 946 .sc_check_scan = ieee80211_swscan_check_scan, 947 .sc_bg_scan = ieee80211_swscan_bg_scan, 948 .sc_cancel_scan = ieee80211_swscan_cancel_scan, 949 .sc_cancel_anyscan = ieee80211_swscan_cancel_anyscan, 950 .sc_scan_next = ieee80211_swscan_scan_next, 951 .sc_scan_done = ieee80211_swscan_scan_done, 952 .sc_scan_probe_curchan = ieee80211_swscan_probe_curchan, 953 .sc_add_scan = ieee80211_swscan_add_scan 954 }; 955 956 /* 957 * Default scan attach method. 958 */ 959 void 960 ieee80211_swscan_attach(struct ieee80211com *ic) 961 { 962 struct scan_state *ss; 963 964 /* 965 * Setup the default methods 966 */ 967 ic->ic_scan_methods = &swscan_methods; 968 969 /* Allocate initial scan state */ 970 ss = (struct scan_state *) IEEE80211_MALLOC(sizeof(struct scan_state), 971 M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 972 if (ss == NULL) { 973 ic->ic_scan = NULL; 974 return; 975 } 976 TASK_INIT(&ss->ss_scan_start, 0, scan_start, ss); 977 TIMEOUT_TASK_INIT(ic->ic_tq, &ss->ss_scan_curchan, 0, 978 scan_curchan_task, ss); 979 980 ic->ic_scan = &ss->base; 981 ss->base.ss_ic = ic; 982 983 ic->ic_scan_curchan = scan_curchan; 984 ic->ic_scan_mindwell = scan_mindwell; 985 } 986