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/if_private.h> 47 #include <net/ethernet.h> 48 49 #include <net80211/ieee80211_var.h> 50 51 #include <net80211/ieee80211_scan_sw.h> 52 53 #include <net/bpf.h> 54 55 struct scan_state { 56 struct ieee80211_scan_state base; /* public state */ 57 58 u_int ss_iflags; /* flags used internally */ 59 #define ISCAN_MINDWELL 0x0001 /* min dwell time reached */ 60 #define ISCAN_DISCARD 0x0002 /* discard rx'd frames */ 61 #define ISCAN_INTERRUPT 0x0004 /* interrupt current scan */ 62 #define ISCAN_CANCEL 0x0008 /* cancel current scan */ 63 #define ISCAN_PAUSE (ISCAN_INTERRUPT | ISCAN_CANCEL) 64 #define ISCAN_ABORT 0x0010 /* end the scan immediately */ 65 #define ISCAN_RUNNING 0x0020 /* scan was started */ 66 67 unsigned long ss_chanmindwell; /* min dwell on curchan */ 68 unsigned long ss_scanend; /* time scan must stop */ 69 u_int ss_duration; /* duration for next scan */ 70 struct task ss_scan_start; /* scan start */ 71 struct timeout_task ss_scan_curchan; /* scan execution */ 72 }; 73 #define SCAN_PRIVATE(ss) ((struct scan_state *) ss) 74 75 /* 76 * Amount of time to go off-channel during a background 77 * scan. This value should be large enough to catch most 78 * ap's but short enough that we can return on-channel 79 * before our listen interval expires. 80 * 81 * XXX tunable 82 * XXX check against configured listen interval 83 */ 84 #define IEEE80211_SCAN_OFFCHANNEL msecs_to_ticks(150) 85 86 static void scan_curchan(struct ieee80211_scan_state *, unsigned long); 87 static void scan_mindwell(struct ieee80211_scan_state *); 88 static void scan_signal(struct ieee80211_scan_state *, int); 89 static void scan_signal_locked(struct ieee80211_scan_state *, int); 90 static void scan_start(void *, int); 91 static void scan_curchan_task(void *, int); 92 static void scan_end(struct ieee80211_scan_state *, int); 93 static void scan_done(struct ieee80211_scan_state *, int); 94 95 MALLOC_DEFINE(M_80211_SCAN, "80211scan", "802.11 scan state"); 96 97 static void 98 ieee80211_swscan_detach(struct ieee80211com *ic) 99 { 100 struct ieee80211_scan_state *ss = ic->ic_scan; 101 102 if (ss != NULL) { 103 scan_signal(ss, ISCAN_ABORT); 104 ieee80211_draintask(ic, &SCAN_PRIVATE(ss)->ss_scan_start); 105 taskqueue_drain_timeout(ic->ic_tq, 106 &SCAN_PRIVATE(ss)->ss_scan_curchan); 107 KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0, 108 ("scan still running")); 109 110 /* 111 * For now, do the ss_ops detach here rather 112 * than ieee80211_scan_detach(). 113 * 114 * I'll figure out how to cleanly split things up 115 * at a later date. 116 */ 117 if (ss->ss_ops != NULL) { 118 ss->ss_ops->scan_detach(ss); 119 ss->ss_ops = NULL; 120 } 121 ic->ic_scan = NULL; 122 IEEE80211_FREE(SCAN_PRIVATE(ss), M_80211_SCAN); 123 } 124 } 125 126 static void 127 ieee80211_swscan_vattach(struct ieee80211vap *vap) 128 { 129 /* nothing to do for now */ 130 /* 131 * TODO: all of the vap scan calls should be methods! 132 */ 133 134 } 135 136 static void 137 ieee80211_swscan_vdetach(struct ieee80211vap *vap) 138 { 139 struct ieee80211com *ic = vap->iv_ic; 140 struct ieee80211_scan_state *ss = ic->ic_scan; 141 142 IEEE80211_LOCK_ASSERT(ic); 143 144 if (ss != NULL && ss->ss_vap == vap && 145 (ic->ic_flags & IEEE80211_F_SCAN)) 146 scan_signal_locked(ss, ISCAN_ABORT); 147 } 148 149 static void 150 ieee80211_swscan_set_scan_duration(struct ieee80211vap *vap, u_int duration) 151 { 152 struct ieee80211com *ic = vap->iv_ic; 153 struct ieee80211_scan_state *ss = ic->ic_scan; 154 155 IEEE80211_LOCK_ASSERT(ic); 156 157 /* NB: flush frames rx'd before 1st channel change */ 158 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD; 159 SCAN_PRIVATE(ss)->ss_duration = duration; 160 } 161 162 /* 163 * Start a scan unless one is already going. 164 */ 165 static int 166 ieee80211_swscan_start_scan_locked(const struct ieee80211_scanner *scan, 167 struct ieee80211vap *vap, int flags, u_int duration, 168 u_int mindwell, u_int maxdwell, 169 u_int nssid, const struct ieee80211_scan_ssid ssids[]) 170 { 171 struct ieee80211com *ic = vap->iv_ic; 172 struct ieee80211_scan_state *ss = ic->ic_scan; 173 174 IEEE80211_LOCK_ASSERT(ic); 175 176 if (ic->ic_flags & IEEE80211_F_CSAPENDING) { 177 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 178 "%s: scan inhibited by pending channel change\n", __func__); 179 } else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) { 180 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 181 "%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n" 182 , __func__ 183 , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive" 184 , duration, mindwell, maxdwell 185 , ieee80211_phymode_name[vap->iv_des_mode] 186 , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append" 187 , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : "" 188 , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : "" 189 , flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : "" 190 , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : "" 191 , flags & IEEE80211_SCAN_ONCE ? ", once" : "" 192 ); 193 194 ieee80211_scan_update_locked(vap, scan); 195 if (ss->ss_ops != NULL) { 196 if ((flags & IEEE80211_SCAN_NOSSID) == 0) 197 ieee80211_scan_copy_ssid(vap, ss, nssid, ssids); 198 199 ss->ss_flags = flags & IEEE80211_SCAN_PUBLIC_MASK; 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 * Start a scan unless one is already going. 237 * 238 * Called without the comlock held; grab the comlock as appropriate. 239 */ 240 static int 241 ieee80211_swscan_start_scan(const struct ieee80211_scanner *scan, 242 struct ieee80211vap *vap, int flags, 243 u_int duration, u_int mindwell, u_int maxdwell, 244 u_int nssid, const struct ieee80211_scan_ssid ssids[]) 245 { 246 struct ieee80211com *ic = vap->iv_ic; 247 int result; 248 249 IEEE80211_UNLOCK_ASSERT(ic); 250 251 IEEE80211_LOCK(ic); 252 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration, 253 mindwell, maxdwell, nssid, ssids); 254 IEEE80211_UNLOCK(ic); 255 256 return result; 257 } 258 259 /* 260 * Check the scan cache for an ap/channel to use; if that 261 * fails then kick off a new scan. 262 * 263 * Called with the comlock held. 264 * 265 * XXX TODO: split out! 266 */ 267 static int 268 ieee80211_swscan_check_scan(const struct ieee80211_scanner *scan, 269 struct ieee80211vap *vap, int flags, 270 u_int duration, u_int mindwell, u_int maxdwell, 271 u_int nssid, const struct ieee80211_scan_ssid ssids[]) 272 { 273 struct ieee80211com *ic = vap->iv_ic; 274 struct ieee80211_scan_state *ss = ic->ic_scan; 275 int result; 276 277 IEEE80211_LOCK_ASSERT(ic); 278 279 if (ss->ss_ops != NULL) { 280 /* XXX verify ss_ops matches vap->iv_opmode */ 281 if ((flags & IEEE80211_SCAN_NOSSID) == 0) { 282 /* 283 * Update the ssid list and mark flags so if 284 * we call start_scan it doesn't duplicate work. 285 */ 286 ieee80211_scan_copy_ssid(vap, ss, nssid, ssids); 287 flags |= IEEE80211_SCAN_NOSSID; 288 } 289 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 && 290 (flags & IEEE80211_SCAN_FLUSH) == 0 && 291 ieee80211_time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) { 292 /* 293 * We're not currently scanning and the cache is 294 * deemed hot enough to consult. Lock out others 295 * by marking IEEE80211_F_SCAN while we decide if 296 * something is already in the scan cache we can 297 * use. Also discard any frames that might come 298 * in while temporarily marked as scanning. 299 */ 300 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 301 "cache hot; ic_lastscan=%d, scanvalid=%d, ticks=%d\n", 302 ic->ic_lastscan, 303 vap->iv_scanvalid, 304 ticks); 305 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD; 306 ic->ic_flags |= IEEE80211_F_SCAN; 307 308 /* NB: need to use supplied flags in check */ 309 ss->ss_flags = flags & IEEE80211_SCAN_PUBLIC_MASK; 310 result = ss->ss_ops->scan_end(ss, vap); 311 312 ic->ic_flags &= ~IEEE80211_F_SCAN; 313 SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD; 314 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 315 "%s: scan_end returned %d\n", __func__, result); 316 if (result) { 317 ieee80211_notify_scan_done(vap); 318 return 1; 319 } 320 } 321 } 322 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration, 323 mindwell, maxdwell, nssid, ssids); 324 325 return result; 326 } 327 328 /* 329 * Restart a previous scan. If the previous scan completed 330 * then we start again using the existing channel list. 331 */ 332 static int 333 ieee80211_swscan_bg_scan(const struct ieee80211_scanner *scan, 334 struct ieee80211vap *vap, int flags) 335 { 336 struct ieee80211com *ic = vap->iv_ic; 337 struct ieee80211_scan_state *ss = ic->ic_scan; 338 bool scanning; 339 340 /* XXX assert unlocked? */ 341 // IEEE80211_UNLOCK_ASSERT(ic); 342 343 IEEE80211_LOCK(ic); 344 scanning = ic->ic_flags & IEEE80211_F_SCAN; 345 if (!scanning) { 346 u_int duration; 347 /* 348 * Go off-channel for a fixed interval that is large 349 * enough to catch most ap's but short enough that 350 * we can return on-channel before our listen interval 351 * expires. 352 */ 353 duration = IEEE80211_SCAN_OFFCHANNEL; 354 355 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 356 "%s: %s scan, ticks %u duration %u\n", __func__, 357 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive", 358 ticks, duration); 359 360 ieee80211_scan_update_locked(vap, scan); 361 if (ss->ss_ops != NULL) { 362 ss->ss_vap = vap; 363 /* 364 * A background scan does not select a new sta; it 365 * just refreshes the scan cache. Also, indicate 366 * the scan logic should follow the beacon schedule: 367 * we go off-channel and scan for a while, then 368 * return to the bss channel to receive a beacon, 369 * then go off-channel again. All during this time 370 * we notify the ap we're in power save mode. When 371 * the scan is complete we leave power save mode. 372 * If any beacon indicates there are frames pending 373 * for us then we drop out of power save mode 374 * (and background scan) automatically by way of the 375 * usual sta power save logic. 376 */ 377 ss->ss_flags |= IEEE80211_SCAN_NOPICK 378 | IEEE80211_SCAN_BGSCAN 379 | flags 380 ; 381 /* if previous scan completed, restart */ 382 if (ss->ss_next >= ss->ss_last) { 383 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 384 vap->iv_stats.is_scan_active++; 385 else 386 vap->iv_stats.is_scan_passive++; 387 /* 388 * NB: beware of the scan cache being flushed; 389 * if the channel list is empty use the 390 * scan_start method to populate it. 391 */ 392 ss->ss_next = 0; 393 if (ss->ss_last != 0) 394 ss->ss_ops->scan_restart(ss, vap); 395 else { 396 ss->ss_ops->scan_start(ss, vap); 397 #ifdef IEEE80211_DEBUG 398 if (ieee80211_msg_scan(vap)) 399 ieee80211_scan_dump(ss); 400 #endif /* IEEE80211_DEBUG */ 401 } 402 } 403 ieee80211_swscan_set_scan_duration(vap, duration); 404 ss->ss_maxdwell = duration; 405 ic->ic_flags |= IEEE80211_F_SCAN; 406 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN; 407 ieee80211_runtask(ic, 408 &SCAN_PRIVATE(ss)->ss_scan_start); 409 scanning = true; 410 } else { 411 /* XXX msg+stat */ 412 } 413 } else { 414 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 415 "%s: %s scan already in progress\n", __func__, 416 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"); 417 } 418 IEEE80211_UNLOCK(ic); 419 420 return (scanning); 421 } 422 423 /* 424 * Taskqueue work to cancel a scan. 425 * 426 * Note: for offload scan devices, we may want to call into the 427 * driver to try and cancel scanning, however it may not be cancelable. 428 */ 429 static void 430 cancel_scan(struct ieee80211vap *vap, int any, const char *func) 431 { 432 struct ieee80211com *ic = vap->iv_ic; 433 struct ieee80211_scan_state *ss = ic->ic_scan; 434 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 435 int signal; 436 437 IEEE80211_LOCK(ic); 438 signal = any ? ISCAN_PAUSE : ISCAN_CANCEL; 439 if ((ic->ic_flags & IEEE80211_F_SCAN) && 440 (any || ss->ss_vap == vap) && 441 (ss_priv->ss_iflags & signal) == 0) { 442 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 443 "%s: %s %s scan\n", func, 444 any ? "pause" : "cancel", 445 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? 446 "active" : "passive"); 447 448 /* clear bg scan NOPICK */ 449 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 450 /* mark request and wake up the scan task */ 451 scan_signal_locked(ss, signal); 452 } else { 453 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 454 "%s: called; F_SCAN=%d, vap=%s, signal=%d\n", 455 func, 456 !! (ic->ic_flags & IEEE80211_F_SCAN), 457 (ss->ss_vap == vap ? "match" : "nomatch"), 458 !! (ss_priv->ss_iflags & signal)); 459 } 460 IEEE80211_UNLOCK(ic); 461 } 462 463 /* 464 * Cancel any scan currently going on for the specified vap. 465 */ 466 static void 467 ieee80211_swscan_cancel_scan(struct ieee80211vap *vap) 468 { 469 cancel_scan(vap, 0, __func__); 470 } 471 472 /* 473 * Cancel any scan currently going on. 474 */ 475 static void 476 ieee80211_swscan_cancel_anyscan(struct ieee80211vap *vap) 477 { 478 479 /* XXX for now - just don't do this per packet. */ 480 if (vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) 481 return; 482 483 cancel_scan(vap, 1, __func__); 484 } 485 486 /* 487 * Manually switch to the next channel in the channel list. 488 * Provided for drivers that manage scanning themselves 489 * (e.g. for firmware-based devices). 490 */ 491 static void 492 ieee80211_swscan_scan_next(struct ieee80211vap *vap) 493 { 494 struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan; 495 496 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__); 497 498 /* wake up the scan task */ 499 scan_signal(ss, 0); 500 } 501 502 /* 503 * Manually stop a scan that is currently running. 504 * Provided for drivers that are not able to scan single channels 505 * (e.g. for firmware-based devices). 506 */ 507 static void 508 ieee80211_swscan_scan_done(struct ieee80211vap *vap) 509 { 510 struct ieee80211com *ic = vap->iv_ic; 511 struct ieee80211_scan_state *ss = ic->ic_scan; 512 513 IEEE80211_LOCK_ASSERT(ic); 514 515 scan_signal_locked(ss, 0); 516 } 517 518 /* 519 * Probe the current channel, if allowed, while scanning. 520 * If the channel is not marked passive-only then send 521 * a probe request immediately. Otherwise mark state and 522 * listen for beacons on the channel; if we receive something 523 * then we'll transmit a probe request. 524 */ 525 static void 526 ieee80211_swscan_probe_curchan(struct ieee80211vap *vap, int force) 527 { 528 struct ieee80211com *ic = vap->iv_ic; 529 struct ieee80211_scan_state *ss = ic->ic_scan; 530 struct ifnet *ifp = vap->iv_ifp; 531 int i; 532 533 /* 534 * Full-offload scan devices don't require this. 535 */ 536 if (vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) 537 return; 538 539 /* 540 * Send directed probe requests followed by any 541 * broadcast probe request. 542 * XXX remove dependence on ic/vap->iv_bss 543 */ 544 for (i = 0; i < ss->ss_nssid; i++) 545 ieee80211_send_probereq(vap->iv_bss, 546 vap->iv_myaddr, ifp->if_broadcastaddr, 547 ifp->if_broadcastaddr, 548 ss->ss_ssid[i].ssid, ss->ss_ssid[i].len); 549 if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0) 550 ieee80211_send_probereq(vap->iv_bss, 551 vap->iv_myaddr, ifp->if_broadcastaddr, 552 ifp->if_broadcastaddr, 553 "", 0); 554 } 555 556 /* 557 * Scan curchan. If this is an active scan and the channel 558 * is not marked passive then send probe request frame(s). 559 * Arrange for the channel change after maxdwell ticks. 560 */ 561 static void 562 scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell) 563 { 564 struct ieee80211vap *vap = ss->ss_vap; 565 struct ieee80211com *ic = ss->ss_ic; 566 567 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 568 "%s: calling; maxdwell=%lu\n", 569 __func__, 570 maxdwell); 571 IEEE80211_LOCK(ic); 572 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 573 ieee80211_probe_curchan(vap, 0); 574 taskqueue_enqueue_timeout(ic->ic_tq, 575 &SCAN_PRIVATE(ss)->ss_scan_curchan, maxdwell); 576 IEEE80211_UNLOCK(ic); 577 } 578 579 static void 580 scan_signal(struct ieee80211_scan_state *ss, int iflags) 581 { 582 struct ieee80211com *ic = ss->ss_ic; 583 584 IEEE80211_UNLOCK_ASSERT(ic); 585 586 IEEE80211_LOCK(ic); 587 scan_signal_locked(ss, iflags); 588 IEEE80211_UNLOCK(ic); 589 } 590 591 static void 592 scan_signal_locked(struct ieee80211_scan_state *ss, int iflags) 593 { 594 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 595 struct timeout_task *scan_task = &ss_priv->ss_scan_curchan; 596 struct ieee80211com *ic = ss->ss_ic; 597 598 IEEE80211_LOCK_ASSERT(ic); 599 600 ss_priv->ss_iflags |= iflags; 601 if (ss_priv->ss_iflags & ISCAN_RUNNING) { 602 if (taskqueue_cancel_timeout(ic->ic_tq, scan_task, NULL) == 0) 603 taskqueue_enqueue_timeout(ic->ic_tq, scan_task, 0); 604 } 605 } 606 607 /* 608 * Handle mindwell requirements completed; initiate a channel 609 * change to the next channel asap. 610 */ 611 static void 612 scan_mindwell(struct ieee80211_scan_state *ss) 613 { 614 615 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: called\n", 616 __func__); 617 618 scan_signal(ss, 0); 619 } 620 621 static void 622 scan_start(void *arg, int pending) 623 { 624 #define ISCAN_REP (ISCAN_MINDWELL | ISCAN_DISCARD) 625 struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg; 626 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 627 struct ieee80211vap *vap = ss->ss_vap; 628 struct ieee80211com *ic = ss->ss_ic; 629 630 IEEE80211_LOCK(ic); 631 if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 || 632 (ss_priv->ss_iflags & ISCAN_ABORT)) { 633 /* Cancelled before we started */ 634 scan_done(ss, 0); 635 return; 636 } 637 638 if (ss->ss_next == ss->ss_last) { 639 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 640 "%s: no channels to scan\n", __func__); 641 scan_done(ss, 1); 642 return; 643 } 644 645 /* 646 * Put the station into power save mode. 647 * 648 * This is only required if we're not a full-offload devices; 649 * those devices manage scan/traffic differently. 650 */ 651 if (((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) == 0) && 652 vap->iv_opmode == IEEE80211_M_STA && 653 vap->iv_state == IEEE80211_S_RUN) { 654 if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) { 655 /* Enable station power save mode */ 656 vap->iv_sta_ps(vap, 1); 657 /* Wait until null data frame will be ACK'ed */ 658 mtx_sleep(vap, IEEE80211_LOCK_OBJ(ic), PCATCH, 659 "sta_ps", msecs_to_ticks(10)); 660 if (ss_priv->ss_iflags & ISCAN_ABORT) { 661 scan_done(ss, 0); 662 return; 663 } 664 } 665 } 666 667 ss_priv->ss_scanend = ticks + ss_priv->ss_duration; 668 669 /* XXX scan state can change! Re-validate scan state! */ 670 671 IEEE80211_UNLOCK(ic); 672 673 ic->ic_scan_start(ic); /* notify driver */ 674 675 scan_curchan_task(ss, 0); 676 } 677 678 static void 679 scan_curchan_task(void *arg, int pending) 680 { 681 struct ieee80211_scan_state *ss = arg; 682 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 683 struct ieee80211com *ic = ss->ss_ic; 684 struct ieee80211_channel *chan; 685 unsigned long maxdwell; 686 int scandone, scanstop; 687 688 IEEE80211_LOCK(ic); 689 end: 690 /* 691 * Note: only /end/ the scan if we're CANCEL rather than 692 * CANCEL+INTERRUPT (ie, 'PAUSE'). 693 * 694 * We can stop the scan if we hit cancel, but we shouldn't 695 * call scan_end(ss, 1) if we're just PAUSEing the scan. 696 */ 697 scandone = (ss->ss_next >= ss->ss_last) || 698 ((ss_priv->ss_iflags & ISCAN_PAUSE) == ISCAN_CANCEL); 699 scanstop = (ss->ss_next >= ss->ss_last) || 700 ((ss_priv->ss_iflags & ISCAN_CANCEL) != 0); 701 702 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, 703 "%s: loop start; scandone=%d, scanstop=%d, ss_iflags=0x%x, ss_next=%u, ss_last=%u\n", 704 __func__, 705 scandone, 706 scanstop, 707 (uint32_t) ss_priv->ss_iflags, 708 (uint32_t) ss->ss_next, 709 (uint32_t) ss->ss_last); 710 711 if (scanstop || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) || 712 (ss_priv->ss_iflags & ISCAN_ABORT) || 713 ieee80211_time_after(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) { 714 ss_priv->ss_iflags &= ~ISCAN_RUNNING; 715 scan_end(ss, scandone); 716 return; 717 } else 718 ss_priv->ss_iflags |= ISCAN_RUNNING; 719 720 chan = ss->ss_chans[ss->ss_next++]; 721 722 /* 723 * Watch for truncation due to the scan end time. 724 */ 725 if (ieee80211_time_after(ticks + ss->ss_maxdwell, ss_priv->ss_scanend)) 726 maxdwell = ss_priv->ss_scanend - ticks; 727 else 728 maxdwell = ss->ss_maxdwell; 729 730 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, 731 "%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n", 732 __func__, 733 ieee80211_chan2ieee(ic, ic->ic_curchan), 734 ieee80211_channel_type_char(ic->ic_curchan), 735 ieee80211_chan2ieee(ic, chan), 736 ieee80211_channel_type_char(chan), 737 (ss->ss_flags & IEEE80211_SCAN_ACTIVE) && 738 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ? 739 "active" : "passive", 740 ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell)); 741 742 /* 743 * Potentially change channel and phy mode. 744 */ 745 ic->ic_curchan = chan; 746 ic->ic_rt = ieee80211_get_ratetable(chan); 747 IEEE80211_UNLOCK(ic); 748 /* 749 * Perform the channel change and scan unlocked so the driver 750 * may sleep. Once set_channel returns the hardware has 751 * completed the channel change. 752 */ 753 ic->ic_set_channel(ic); 754 ieee80211_radiotap_chan_change(ic); 755 756 /* 757 * Scan curchan. Drivers for "intelligent hardware" 758 * override ic_scan_curchan to tell the device to do 759 * the work. Otherwise we manage the work ourselves; 760 * sending a probe request (as needed), and arming the 761 * timeout to switch channels after maxdwell ticks. 762 * 763 * scan_curchan should only pause for the time required to 764 * prepare/initiate the hardware for the scan (if at all). 765 */ 766 ic->ic_scan_curchan(ss, maxdwell); 767 IEEE80211_LOCK(ic); 768 769 /* XXX scan state can change! Re-validate scan state! */ 770 771 ss_priv->ss_chanmindwell = ticks + ss->ss_mindwell; 772 /* clear mindwell lock and initial channel change flush */ 773 ss_priv->ss_iflags &= ~ISCAN_REP; 774 775 if (ss_priv->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)) { 776 taskqueue_cancel_timeout(ic->ic_tq, &ss_priv->ss_scan_curchan, 777 NULL); 778 goto end; 779 } 780 781 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: waiting\n", 782 __func__); 783 IEEE80211_UNLOCK(ic); 784 } 785 786 static void 787 scan_end(struct ieee80211_scan_state *ss, int scandone) 788 { 789 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 790 struct ieee80211vap *vap = ss->ss_vap; 791 struct ieee80211com *ic = ss->ss_ic; 792 793 IEEE80211_LOCK_ASSERT(ic); 794 795 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: out\n", __func__); 796 797 if (ss_priv->ss_iflags & ISCAN_ABORT) { 798 scan_done(ss, scandone); 799 return; 800 } 801 802 IEEE80211_UNLOCK(ic); 803 ic->ic_scan_end(ic); /* notify driver */ 804 IEEE80211_LOCK(ic); 805 /* XXX scan state can change! Re-validate scan state! */ 806 807 /* 808 * Since a cancellation may have occurred during one of the 809 * driver calls (whilst unlocked), update scandone. 810 */ 811 if ((scandone == 0) && ((ss_priv->ss_iflags & ISCAN_PAUSE) == ISCAN_CANCEL)) { 812 /* XXX printf? */ 813 if_printf(vap->iv_ifp, 814 "%s: OOPS! scan cancelled during driver call (1) (ss_iflags=0x%x)!\n", 815 __func__, 816 ss_priv->ss_iflags); 817 scandone = 1; 818 } 819 820 /* 821 * Record scan complete time. Note that we also do 822 * this when canceled so any background scan will 823 * not be restarted for a while. 824 */ 825 if (scandone) 826 ic->ic_lastscan = ticks; 827 /* return to the bss channel */ 828 if (ic->ic_bsschan != IEEE80211_CHAN_ANYC && 829 ic->ic_curchan != ic->ic_bsschan) { 830 ieee80211_setupcurchan(ic, ic->ic_bsschan); 831 IEEE80211_UNLOCK(ic); 832 ic->ic_set_channel(ic); 833 ieee80211_radiotap_chan_change(ic); 834 IEEE80211_LOCK(ic); 835 } 836 /* clear internal flags and any indication of a pick */ 837 ss_priv->ss_iflags &= ~ISCAN_REP; 838 ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK; 839 840 /* 841 * If not canceled and scan completed, do post-processing. 842 * If the callback function returns 0, then it wants to 843 * continue/restart scanning. Unfortunately we needed to 844 * notify the driver to end the scan above to avoid having 845 * rx frames alter the scan candidate list. 846 */ 847 if ((ss_priv->ss_iflags & ISCAN_CANCEL) == 0 && 848 !ss->ss_ops->scan_end(ss, vap) && 849 (ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 && 850 ieee80211_time_before(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) { 851 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 852 "%s: done, restart " 853 "[ticks %u, dwell min %lu scanend %lu]\n", 854 __func__, 855 ticks, ss->ss_mindwell, ss_priv->ss_scanend); 856 ss->ss_next = 0; /* reset to beginning */ 857 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 858 vap->iv_stats.is_scan_active++; 859 else 860 vap->iv_stats.is_scan_passive++; 861 862 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 } 892 893 static void 894 scan_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 */ 950 static void 951 ieee80211_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 } 997 998 static 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 */ 1018 void 1019 ieee80211_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